Silver Nanoparticles: Properties, Synthesis, Characterization, Applications and Future Trends

*Sunil T. Galatage, Aditya S. Hebalkar, Shradhey V. Dhobale, Omkar R. Mali, Pranav S. Kumbhar, Supriya V. Nikade and Suresh G. Killedar*


*Article* **Primary Staging of Prostate Cancer Patients with [ 18F]PSMA-1007 PET/CT Compared with [68Ga]Ga-PSMA-11 PET/CT**

**Manuela A. Hoffmann 1,2,\*, Jonas Müller-Hübenthal 3, Florian Rosar 4, Nicolas Fischer 5, Finn Edler von Eyben 6, Hans-Georg Buchholz 2, Helmut J. Wieler 7 and Mathias Schreckenberger 2**

**Abstract:** Background: Hybrid imaging with prostate-specific membrane antigen (PSMA) is gaining importance as an increasingly meaningful tool for prostate cancer (PC) diagnostics and as a guide for therapy decisions. This study aims to investigate and compare the performance of [18F]PSMA-1007 (18F-PSMA) and [68Ga]Ga-PSMA-11 positron emission tomography/computed tomography ( 68Ga-PSMA) in the initial staging of PC patients. Methods: The data of 88 biopsy-proven patients were retrospectively evaluated. PSMA-avid lesions were compared with the histopathologic Gleason Score (GS) for prostate biopsies, and the results were plotted by receiver operating characteristic (ROC)-curve. Optimal maximum standardized uptake value (SUVmax) cut-off values were rated using the Youden index. Results: 18F-PSMA was able to distinguish GS ≤ 7a from ≥7b with a sensitivity of 62%, specificity of 85%, positive predictive value (PPV) of 92%, and accuracy of 67% for a SUVmax of 8.95, whereas sensitivity was 54%, specificity 91%, PPV 93%, and accuracy 66% for 68Ga-PSMA (SUVmax 8.7). Conclusions: Both methods demonstrated a high concordance of detected PSMA-avid lesions with histopathologically proven PC. 18F-PSMA and 68Ga-PSMA are both suitable for the characterization of primary PC with a comparable correlation of PSMA-avid lesions with GS. Neither method showed a superior advantage. Our calculated SUVmax thresholds may represent valuable parameters in clinical use to distinguish clinically significant PC (csPC) from non-csPC.

**Keywords:** PSMA hybrid imaging; staging of primary prostate cancer; [18F]PSMA-1007; [68Ga]Ga-PSMA-11; SUVmax cut-off level; prostate carcinoma


**1. Introduction**

Obesity has become a public health problem that has shifted from being a problem in rich countries to one that is found across all income levels. Worldwide obesity has nearly tripled and it is estimated that 4.7 million people died

prematurely in 2017 due to obesity-related causes [1]. The number of premature deaths due to obesity-related causes is projected to increase to 5.5 million in 2025 [2]. Sub-Saharan Africa has the lowest prevalence of obesity in comparison to other regions of the world [3]. However, the prevalence of obesity and overweight is projected to increase in the next two decades [4] and Southern Africa is disproportional affected [5]. In response to this, World Health Organisation (WHO) came out with "Global action plan on physical activity 2018–2030: more active people for a healthier world" which is aimed at providing effective and feasible policy actions to increase physical activity globally [6]. In Zimbabwe, the prevalence of overweight and obesity increased substantially over the decade from 25% in 2005 to 36.6% in 2015 [7]. Obesity is likely to lead to death, high blood pressure/hypertension, high cholesterol coronary, diabetes, cardiovascular diseases (CVDs), hypertension, coronary heart disease, and stroke [6].

Researches have shown an association between religious affiliation and obesity and overweight. This finding can be explained in the context of a study by Kahan (2015) in 38 countries that found high rates of physical inactivity among Muslim women, as well as Benjamin and Donnelly (2013) who conducted a study on barriers and facilitators influencing the physical activity of Arabic adults [23, 24]. Married women are more susceptible to being overweight or obese, thus marital status is a strong predictor of obesity [25]. Hormonal contraception use has been found to increase the risk of obesity and injected depot medroxyprogesterone

*Factors Associated with Overweight and Obesity among Women Aged 15-49 Years…*

The rapidly changing role of women in African societies, with their increasing involvement in the labour force, especially in urban areas contribute to the dramatic changes in dietary patterns and food supply occurring in these settings [28]. In addition, in these settings, a direct relationship between socioeconomic status and obesity has been observed, since higher socioeconomic groups are more likely to buy extra food and achieve their desire to look healthy and strong [29]. Therefore, this paper aim to investigate the problem of obesity and included household assets

This paper utilises pooled data from 3 consecutive Zimbabwe Demographic and Health Surveys (ZDHS) from the following years; 2005/6, 2010/11 and 2015. The ZDHS is a nationally representative sample survey of women aged 15–49 years, which is conducted every five years. Permission to use the data sets was sought from Measure DHS. The data collected covers: individual and household level sociodemographic; health and sexual activity; maternal and child health; mortality; fer-

The sample sizes of the interviewed women aged 15–49 were selected based on a master sampling plan, which was provided by the Central Statistics Office (1988– 2005) and Zimbabwe National Statistics Agency (ZIMSTAT) (2010–2015). A twostage cluster sampling process was used. Firstly, enumeration areas were selected from a list of clusters obtained from the master sampling plan provided by

ZIMSTAT, followed by a selection of households from each cluster. All women aged 15–49 years were selected from each selected household and interviewed. Informed consent was obtained from the respondents before being interviewed. The analysis was limited to currently non-pregnant women aged 15–49 years who were *dejure* household members: survey year 2005/6, n = 7,798; 2010/11, n = 7,612; and 2015,

Overweight and obesity was the outcome variable and the measurement of obesity is based on the Quetelet Index, also known as body mass index (BMI). BMI

). The biomarkers took the weight and

n = 8,552). All data sets from the three surveys were weighted.

acetate also increased weight [26, 27].

*DOI: http://dx.doi.org/10.5772/intechopen.95909*

as part of the background variables.

tility; family planning; and nutrition.

**2.2 Study participants and sample size**

**2. Methods**

**3. Variables**

**121**

**3.1 Dependent variable**

is weight divided by height squared (kg/m2

**2.1 Source of data**

Evidence from several research studies indicated that socio-economic background factors increased the likelihood for individuals to end up being obesity. The emerging prevalence of overweight and obesity in Africa has been largely attributed to the rising level of urbanisation in the region and its attendant global nutrition transition [8]. Urbanisation in Africa is increasing rapidly and African countries are projected to have 50% urbanisation by 2020 [9]. These risk factors of obesity are similar to those found in several studies across the world as accounting for the increasing overweight and obesity epidemic in developing countries and the stall in the phenomenon in developed countries [10, 11]. Literature is showing differences in overweight and obesity to the disadvantage of those in urban settings [5]. These rural– urban disparities could be explained by the differences in lifestyle such as time spent watching television, mechanisation of occupation and dietary pattern in Africa [5, 12, 13]. Studies elsewhere have confirmed that women who were informally employed and listened to the radio were less likely to be overweight or obese compared to those who were unemployed and did not listen to the radio, respectively [14].

Research had shown socioeconomic differences in overweight and obesity by the level of education and wealth to the detriment of those with lower socio-economic status in most countries across Africa similar to those found in other previous studies [15]. Studies have argued that cultural norms that favour fatter body size contribute significantly to the socio-economic status differences in overweight and obesity in developing countries, particularly in Africa [16]. Women of higher socioeconomic status have the resources and knowledge of the importance of physical activity and healthy diet but they also face several socio-cultural barriers that may prevent them from putting those into use [17]. With specific reference to those with no education, research had shown that the odds of being overweight/obese significantly increased with the level of education [18].

Studies have revealed a significant association between overweight/obesity and age [14, 19, 20]. Studies have shown the likelihood of obesity and overweight to be high among older women and the possible reason for this finding maybe that old age is likely to be characterised by high physical inactivity as well as the consumption of more energy-dense foods, which may result in overweight and obesity [14]. Another possible explanation for this could be that, as people grow, the composition of their body changes, which results in an increase in fat mass and a decline in fatfree mass [19, 20]. Overweight and obesity vary greatly between men and women, with women across the globe disproportionately affected [21]. Generally, women with higher parities have been found to have higher retention of gestational weight gain and consequently the onset of overweight and obesity [16, 22]. The real impact of parity and associated reproductive factors could, however, be modest and intertwined in a complex pattern with socio-cultural, demographic and socio-economic factors, as well as other risk factors [22].

*Factors Associated with Overweight and Obesity among Women Aged 15-49 Years… DOI: http://dx.doi.org/10.5772/intechopen.95909*

Researches have shown an association between religious affiliation and obesity and overweight. This finding can be explained in the context of a study by Kahan (2015) in 38 countries that found high rates of physical inactivity among Muslim women, as well as Benjamin and Donnelly (2013) who conducted a study on barriers and facilitators influencing the physical activity of Arabic adults [23, 24]. Married women are more susceptible to being overweight or obese, thus marital status is a strong predictor of obesity [25]. Hormonal contraception use has been found to increase the risk of obesity and injected depot medroxyprogesterone acetate also increased weight [26, 27].

The rapidly changing role of women in African societies, with their increasing involvement in the labour force, especially in urban areas contribute to the dramatic changes in dietary patterns and food supply occurring in these settings [28]. In addition, in these settings, a direct relationship between socioeconomic status and obesity has been observed, since higher socioeconomic groups are more likely to buy extra food and achieve their desire to look healthy and strong [29]. Therefore, this paper aim to investigate the problem of obesity and included household assets as part of the background variables.

### **2. Methods**

#### **2.1 Source of data**

This paper utilises pooled data from 3 consecutive Zimbabwe Demographic and Health Surveys (ZDHS) from the following years; 2005/6, 2010/11 and 2015. The ZDHS is a nationally representative sample survey of women aged 15–49 years, which is conducted every five years. Permission to use the data sets was sought from Measure DHS. The data collected covers: individual and household level sociodemographic; health and sexual activity; maternal and child health; mortality; fertility; family planning; and nutrition.

#### **2.2 Study participants and sample size**

The sample sizes of the interviewed women aged 15–49 were selected based on a master sampling plan, which was provided by the Central Statistics Office (1988– 2005) and Zimbabwe National Statistics Agency (ZIMSTAT) (2010–2015). A twostage cluster sampling process was used. Firstly, enumeration areas were selected from a list of clusters obtained from the master sampling plan provided by ZIMSTAT, followed by a selection of households from each cluster. All women aged 15–49 years were selected from each selected household and interviewed. Informed consent was obtained from the respondents before being interviewed. The analysis was limited to currently non-pregnant women aged 15–49 years who were *dejure* household members: survey year 2005/6, n = 7,798; 2010/11, n = 7,612; and 2015, n = 8,552). All data sets from the three surveys were weighted.

#### **3. Variables**

#### **3.1 Dependent variable**

Overweight and obesity was the outcome variable and the measurement of obesity is based on the Quetelet Index, also known as body mass index (BMI). BMI is weight divided by height squared (kg/m2 ). The biomarkers took the weight and

height measurements during the face-to-face interviews. The study adopted the widely accepted definition of overweight and obesity as a BMI of ≥25.0 kg/m2 and 30 kg/m2 , respectively. Overweight and obesity were combined as one category to ensure enough cases for the analysis. We use a binary variable to classify respondents whose BMI was ≥25.0 kg/m2 as overweight and obesity and coded "1" while those below 25.0 kg/m2 were classified otherwise and coded "0".

**Variables 2005/06(%) 2010/11(%) 2015(%)**

*Factors Associated with Overweight and Obesity among Women Aged 15-49 Years…*

Urban 3,136 (40.2) 2911(38.3) 3,260(38.1) Rural 4661(59.8) 4,700(61.7) 5,292 (61.9)

Poorest 1,340 (17.2) 1288(16.9) 1,468 (17.2) Poorer 1,271 (16.3) 1,320(17.4) 1,452(17.0) Middle 1,345 (17.2) 1382(18.2) 1,536(18.0) Richer 1765 (22.6) 1,697 (22.3) 1,945(22.7) Richest 2077(26.6) 1922(25.3) 2,151(25.1)

No Education/Primary 2869(36.8) 2310 (30.4) 2,328(27.2) Secondary 4690(60.2) 4933 (54.8) 5,603(65.5) Higher 238(3.1) 368(4.8) 620(7.3)

–19 1880 (24.1) 1638(21.5) 1,912 (2.3) –24 1605 (20.6) 1452 (19.1) 1,381 (16.5) –29 1249(16.0) 1,317(17.3) 1,381 (16.5) –34 1,073 (13.8) 1084(14.2) 1,345(15.7) –39 769(9.9) 874(11.5) 1095(12.8) 40-44 652(8.4) 673(8.9) 907(10.6 45-49 570(7.3) 574(7.5) 528(6.2)

<2 3654 (46.9) 3353(44.1) 3,524 (41.2) 2–3 2288(29.3) 2550(33.5) 2,977 (34.8) 4–5 1118(14.4) 1158(15.2) 1,508 (17.6) 6+ 738(9.5) 551 (7.2) 543 (6.4)

Roman Catholic 793 (10.2) 653(8.6) 575 (6.7) Protestant 2042 (26.2) 1290 (17.0) 1,390 (16.3) Pentecostal 1384 (17.8) 1643 (21.6) 2,138 (25.0) Apostolic sect 2278 (29.2) 2,844(37.4) 3,542 (41.4) Others 1300(16.7) 1181 (15.2) 906 (10.6)

Never in Union 2253 (28.9) 1964(25.8) 2,278(26.6) Currently in Union 4260 (54.6) 4523(59.5) 5,089(59.5) Formerly in Union 1285 (16.5) 1121 (14.7) 1,186(13.9)

Working 2942 (37.8) 2875 (37.8) 3,598(42.1) Not Working 4841(62.4) 4737(62.2) 4,954(57.9)

**Place of Residence**

*DOI: http://dx.doi.org/10.5772/intechopen.95909*

**Household wealth**

**Level of Education**

**Age**

**Parity**

**Religion**

**Marital Status**

**Employment status**

**123**

#### **3.2 Independent variables**

The independent variables used in this study were categorised into two groups: demographic factors and socioeconomic status (SES). The demographic factors were: age (15–19, 20–24, 25–29, 30–34, 35–39, 40–49); parity (<2, 2–3, 4–5, 6+); marital status (never in a union, currently in a union, and formerly in a union); religion (Roman Catholic, Protestant, Pentecostal and others). SES was measured using six indicators: wealth (poorest, poorer, middle, richer and richest); the level of education (no education and primary were collapsed for easy analysis), secondary, higher education); employment status (unemployed and employed); place of residence (rural or urban); region or province all (ten Zimbabwean provinces were included); and household assets (radio, television and telephone).

#### **3.3 Data analysis**

We used frequency distributions to describe and summarise the characteristics of the respondents across all three survey years under study. In addition, the bivariate relationship between the background characteristics and the dependent variable were examined using the Chi-square test of independence. In the last part, three binary logistic regression models were fitted to examine the associations between the independent variables and the outcome variable.

## **4. Findings**

About a quarter (25.2%) of the women were either overweight or obese in 2015, 31.3% in 2010 and 34.9% in 2015 (**Table 1**). The majority of women sampled were from rural areas, 59.8% in 2005, 61.7% in 2010 and 61.9% in 2015. More than twothirds of women came from households that had wealth between middle and richest, 66.4% in 2005, 65.8% in 2010 and 65.8% in 2015. At least sixty percent of women had at least secondary education, 63.3% in 2005, 59.6% in 2010 and 72.8%. Most respondents were aged between 15 and 34 years, 74.5% in 2005, 72.1% in 2010 and 51% in 2015. The majority of women had parity <2, 46.9% in 2005, 44.1% in 2010, 41.2 in 2015. The most common religion was Apostolic sect, 29.2% in 2005, 37.4% in 2010 and 41.4% in 2020. More than half of women were currently in a union, 54.6% in 2005, 59.5% in 2010 and 59.5% in 2015. In terms of employment, most women were not working, 62.4% in 2005, 62.2% in 2010 and 57.9% in 2015. The highest proportions of women were from Harare province, 17% in 2005, 18.4% in 2010 and 17.8% in 2015. The least proportion of women was from Matebeleland South province, 5.0% in 2005, 5.2% in 2010 and 4.2% in 2015. Close to half of the women reported that their household owned a radio (55.2% in 2005, 41.3% in 2010 and 55.6% in 2015). Around 40% of women reported that their household owned a television set (39.2% in 2005, 43.2% in 2010 and 44.3% in 2015). Ownership of a telephone was low, 11.4% in 2005, 4.9% in 2010 and 3.9% in 2015.

*Factors Associated with Overweight and Obesity among Women Aged 15-49 Years… DOI: http://dx.doi.org/10.5772/intechopen.95909*

**Variables 2005/06(%) 2010/11(%) 2015(%)**

*Factors Associated with Overweight and Obesity among Women Aged 15-49 Years…*

The results show that there has been an increasing trend in the percentage of women in Zimbabwe who were either overweight or obese from 2005/06 (25.2%) to 2015 (34.9%) (See **Table 2**).

The results of the bivariate analysis reveal a significant association between background variables and overweight/obesity (**Table 2**). Women from urban areas were more likely to be overweight or obese (35.8 in 2005, 40.3% in 2010 and 46.7% in 2015) compared to those from rural areas (18% in 2005/06, 25.4% in 2010/11 and 27.7% in 2015) (p = 0.000). Similarly, urban provinces such as Harare and Bulawayo were more likely to have women who were obese and overweight compared to women in rural provinces (p = 0.000). Women from richest households were at higher risk of overweight/obesity over the period, 39.1% in 2005, 42.5% in 2010 and 50% in 2015 compared to women from the poorest households (13.6, 17.4 and 18.7%, respectively) (p = 0.000). Similarly, the level of education was associated with the prevalence of overweight/obesity (p = 0.000). Women with higher education were more likely to be obese/overweight (57.4% in 2005, 48% in 2010 and 57% in 2015) compared to women with primary or no education (22.6%, 29.5% and 28.2%, respectively) (p = 0.000). Obesity/overweight increased with parity, for 2005/06 and 2010/11, the highest prevalence of overweight/obesity was among women with 4–5 children while for 2015, the highest prevalence was among women

*Factors Associated with Overweight and Obesity among Women Aged 15-49 Years… DOI: http://dx.doi.org/10.5772/intechopen.95909*

**Variables 2005**

*DOI: http://dx.doi.org/10.5772/intechopen.95909*

**Place of Residence** Urban (ref)

**Household wealth** Poorest(ref)

**Level of Education** No Education/Primary(ref)

**Age** 15–19(ref)

**Parity** <2 (ref)

**Religion**

Roman Catholic(ref)

**Marital Status** Never in Union(ref)

**Employment status** Not Working(ref)

**127**

**aOR(95% CI)**

*Factors Associated with Overweight and Obesity among Women Aged 15-49 Years…*

Rural 0.95 (0.72-1.22) 0.80(0.64-0.99)\*\* 1.11 (0 .87-1.42)

Poorer 1.18 (0.93- 1.49) 1.58(1.28- 1.95)\*\*\* 1.46(1.17-1.81)\*\*\* Middle 1.44(1.12-1.84)\*\* 1.95 (1.56-2.47)\*\*\* 1.95(1.58-2.41)\*\*\* Richer 2.35(1.70-3.20)\*\*\* 2.38 (1.82-3.10)\*\*\* 3.06 (2.32-4.05)\*\*\* Richest 3.06 (2.06-4.56)\*\*\* 3.92(2.11-4.04)\*\*\* 4.56 (3.20-6.51)\*\*\*

Secondary 1.05( 0.89-1.25) 1.08 (0.92-1.27) 1.17 (1.01-1.35)\*\* Higher 1.89(1.37-2.60)\*\*\* 1.19(0.89-1.60) 1.32 (1.01- 1.72)\*\*

–24 1.37 (1.06-1.75)\*\* 1.44 (1.12-1.84)\*\* 1.42(1.12- 1.80)\*\* –29 1.96(1.48- 2.59)\*\*\* 2.41 (1.87-3.12)\*\*\* 2.25(1.69-3.00)\*\*\* –34 2.44 (1.82-3.28)\*\*\* 2.99 (2.29- 3.92)\*\*\* 3.38(2.53-4.50)\*\*\* –39 3.24(2.41-4.36)\*\*\* 3.58 (2.65- 4.84)\*\*\* 3.70(2.71-5.05)\*\*\* 40-44 3.69(2.73- 5.00)\*\*\* 4.43 (3.21-6.11)\*\*\* 4.75 (3.50-6.46)\*\*\* 45-49 4.16 (3.94-6.88)\*\*\* 5.04(3.61-7.03)\*\*\* 4.74(3.31-6.78)\*\*\*

2–3 1.25 (1.04-1.51)\*\* 1.18 (0.97-1.44) 1.19(0.99- 1.43)\* 4–5 1.49(1.15- 1.92)\*\* 1.60 (1.26- 2.07)\*\*\* 1.22(0.96- 1.56)\* 6+ 1.50(1.11-2.03)\*\* 1.56(1.16-2.09)\*\* 1.58 (1.17- 2.15)\*\*

Protestant 1.00 (0.82-1.22) 0.97 (0.76-1.24) 1.07 (0.82-1.37) Pentecostal 0.85 (0.69-1.06) 0.85(0.67-1.08) 1.00 (0.79-1.27) Apostolic sect 0.75 (0.61-0.92)\*\* 0.68 (0.54-0.86)\*\*\* 0.87 (0.67-1.14) Others 0.67(0.54-0.85)\*\* 0.71(0.55-0.931)\*\* 1.02(0.78-1.33)

Currently in Union 1.44 (1.14-1.83)\*\* 1.68 (1.32-2.14)\*\*\* 1.65(1.36-2.01)\*\*\* Formerly in Union 1.13(0.86-1.49)\*\*\* 1.35(1.02-1.79)\*\* 1.39(1.10- 1.75)\*\*

Working 1.23 (1.06- 1.44)\*\* 1.04(0.91-1.19) 1.15 (1.00-1.31)\*\*

**2010 aOR(95% CI)** **2015 aOR(95% CI)**

#### **Table 2.**

*Prevalence of overweight and obesity by background variables.*

with 6+ children (p = 0.000). Women currently in a union or formerly in the union were more likely to be overweight or obese compared to women who have never been in union (p = 0.000). For 2005/06 and 2015, women who were working were at higher risk of overweight/obesity (31.7% in 2005 and 44.7% in 2015) compared to women not working (21.3% and 27.8%, respectively) p = 0.000). For 2010/11, women who were not working were more likely to be overweight or obese (38.7%) than those not working (26.8%) (p = 0.000) in 2010.

Household asset ownership was associated with the prevalence of overweight/ obesity. Women from households with radios were more likely to be overweight/ obese (31% in 2005/06, 34.9% in 2010/11) compared to women from households without a radio had prevalence of (18.0% in 2005, and 28.8% in 2010) (p = 0.00). Women from households with television were more likely to be overweight or obese (35.5% in 2005, 40.1% in 2010 and 44.2% in 2015) compared to women from households without a television (18.5%, 26.6% and 27.5%, respectively) (p = 0.000). Women from households which owned a telephone had the highest prevalence of overweight/obesity, 42.0% in 2005, 44.3% in 2010 and 46.0% in 2015 **Variables 2005 aOR(95% CI) 2010 aOR(95% CI) 2015 aOR(95% CI) Place of Residence** Urban (ref) Rural 0.95 (0.72-1.22) 0.80(0.64-0.99)\*\* 1.11 (0 .87-1.42) **Household wealth** Poorest(ref) Poorer 1.18 (0.93- 1.49) 1.58(1.28- 1.95)\*\*\* 1.46(1.17-1.81)\*\*\* Middle 1.44(1.12-1.84)\*\* 1.95 (1.56-2.47)\*\*\* 1.95(1.58-2.41)\*\*\* Richer 2.35(1.70-3.20)\*\*\* 2.38 (1.82-3.10)\*\*\* 3.06 (2.32-4.05)\*\*\* Richest 3.06 (2.06-4.56)\*\*\* 3.92(2.11-4.04)\*\*\* 4.56 (3.20-6.51)\*\*\* **Level of Education** No Education/Primary(ref) Secondary 1.05( 0.89-1.25) 1.08 (0.92-1.27) 1.17 (1.01-1.35)\*\* Higher 1.89(1.37-2.60)\*\*\* 1.19(0.89-1.60) 1.32 (1.01- 1.72)\*\* **Age** 15–19(ref) 20–24 1.37 (1.06-1.75)\*\* 1.44 (1.12-1.84)\*\* 1.42(1.12- 1.80)\*\* 25–29 1.96(1.48- 2.59)\*\*\* 2.41 (1.87-3.12)\*\*\* 2.25(1.69-3.00)\*\*\* 30–34 2.44 (1.82-3.28)\*\*\* 2.99 (2.29- 3.92)\*\*\* 3.38(2.53-4.50)\*\*\* 35–39 3.24(2.41-4.36)\*\*\* 3.58 (2.65- 4.84)\*\*\* 3.70(2.71-5.05)\*\*\* 40-44 3.69(2.73- 5.00)\*\*\* 4.43 (3.21-6.11)\*\*\* 4.75 (3.50-6.46)\*\*\* 45-49 4.16 (3.94-6.88)\*\*\* 5.04(3.61-7.03)\*\*\* 4.74(3.31-6.78)\*\*\* **Parity** <2 (ref) 2–3 1.25 (1.04-1.51)\*\* 1.18 (0.97-1.44) 1.19(0.99- 1.43)\* 4–5 1.49(1.15- 1.92)\*\* 1.60 (1.26- 2.07)\*\*\* 1.22(0.96- 1.56)\* 6+ 1.50(1.11-2.03)\*\* 1.56(1.16-2.09)\*\* 1.58 (1.17- 2.15)\*\* **Religion** Roman Catholic(ref) Protestant 1.00 (0.82-1.22) 0.97 (0.76-1.24) 1.07 (0.82-1.37) Pentecostal 0.85 (0.69-1.06) 0.85(0.67-1.08) 1.00 (0.79-1.27) Apostolic sect 0.75 (0.61-0.92)\*\* 0.68 (0.54-0.86)\*\*\* 0.87 (0.67-1.14) Others 0.67(0.54-0.85)\*\* 0.71(0.55-0.931)\*\* 1.02(0.78-1.33) **Marital Status** Never in Union(ref) Currently in Union 1.44 (1.14-1.83)\*\* 1.68 (1.32-2.14)\*\*\* 1.65(1.36-2.01)\*\*\* Formerly in Union 1.13(0.86-1.49)\*\*\* 1.35(1.02-1.79)\*\* 1.39(1.10- 1.75)\*\* **Employment status** Not Working(ref) Working 1.23 (1.06- 1.44)\*\* 1.04(0.91-1.19) 1.15 (1.00-1.31)\*\*

*Factors Associated with Overweight and Obesity among Women Aged 15-49 Years… DOI: http://dx.doi.org/10.5772/intechopen.95909*

#### *Lifestyle and Epidemiology - The Double Burden of Poverty and Cardiovascular Diseases…*

higher chances of being overweight/obese compared to those with parity of <2 in three periods, 2005, 2010 and 2015 (p < 0.05). Women currently in union were more likely to be overweight/obese compared to those never in union, 44% higher chances in 2005 (p < 0.05), 68% higher chance in 2010 (p < 0.001) and 65%

*Factors Associated with Overweight and Obesity among Women Aged 15-49 Years…*

Working increased odds of overweight/obesity compared to those not working, aOR = 1.23 in 2005, and aOR = 1.15 in 2015 (p < 0.05). Household ownership of radio and telephone did not show a statistically significant association with women's chances of being overweight or obese. Household ownership of television showed a significant increased likelihood of overweight/obesity in 2010 only (aOR = 1.25)

The aim of the study was to examine factors associated with overweight and obesity among women aged 15–49 years in Zimbabwe. Our study found that rural women were less likely to be overweight and obese than urban women. Similar findings were also reported by Neupane, Prakash and Doku 2015 who found obesity to be more prevalent in urban setups [5]. Neupane et al. [5] attributed this disparity to differences in lifestyle, dietary pattern and type of occupation. Women in rural areas tend to be involved in activities that call for their energy use such as farming, collecting firewood and fetching water and thus use up lots of calories. The study findings also reveal that women from richer households had higher odds of overweight and obesity than women from the poorest households. Similar findings were reported by Neupane et al. [5]. We found higher education and working status to be constantly associated with overweight/obesity in 2005 and 2015 and not in 2010/11. Studies elsewhere concur with current findings [18]. This could be related to the fact that these highly educated women are more likely to be working and more likely to come from richer households, and thus use energy saving devices at home to execute their daily domestic chores or can afford to employ domestic workers. In addition, some women tend to afford eating western food outlets at work which are perceived to be 'junk' and fatty food. However, the period 2010/11 has no statistically significant relationships as the period comes immediately after the economic challenges that occurred in 2008, spilling the effects into this period, such that education and working were overridden by other factors, thus diluting the relationship of these factors with overweight/obesity. Ownership of household assets was not associated with overweight or obesity except for television in 2010/11. This is contrary to other studies which found asset ownership such as radio and telephone to be associated with obesity. It is not surprising that a sedentary lifestyle has been observed to closely relate to time spent watching television as a leisure activity [13, 18]. Subsequently, reduced energy expenditure because of this leisure activity

Age was a constant predictor of overweight and obesity in all three surveys. With increasing age, women tend to be at higher odds ratios of becoming overweight and obese. Elsewhere in similar settings, the prevalence of overweight and obesity was also reported to be higher among older women [14, 19, 20]. Other studies associate obesity in old age to be characterised by high physical inactivity as well as the consumption of more energy-dense foods, which may result in overweight and obesity [14]. The current study found parity to be significantly associated with overweight/obesity. Similarly, several studies found multiparous women had the highest odds of being obese [7, 14] as well associated with the onset of higher retention of gestational weight gain [16, 22]. Marital status also emerged as a

higher chance in 2015 (p < 0.001) (**Table 3**).

*DOI: http://dx.doi.org/10.5772/intechopen.95909*

**5. Discussion**

**129**

(p < 0.05) with no significant likelihood in 2005 and 2015.

is closely associated with overweight and obesity.

#### **Table 3.**

*Odds ratio estimates for overweight /obesity women aged 15-49 years from 2005-2015 in Zimbabwe.*

compared to women with households without a telephone (23%, 30.6% and 34.5%, respectively) (p = 0.000).

**Table 3** shows the results of the multiple regression, indicating variables that are statistically significant after controlling for other factors. Women from rural areas were less likely to be overweight/obese compared to those from urban areas only in 2010 (aOR = 0.80, p < 0.05). Household wealth was associated with being overweight/obese, with women from richest households were three times (aOR = 3.06), four times (aOR = 3.92) and five times (aOR = 4.56) more likely to be overweight/ obese compared to those from poorest households in 2005, 2010 and 2015, respectively (p < 0.001). In 2005/06, women with higher education had a significantly higher likelihood of being overweight/obese compared to those with no/primary education (1.89 times higher, p < 0.001), while in 2015, women with secondary and higher education were 1.17 and 1.32 more likely to be overweight/obese, respectively than those with primary or no education (p < 0.05). Older women aged 45–49 years had increased odds of overweight/obesity compared to the young women aged 15–19 years, four times (aOR = 3.06) in 2005, five times (aOR = 5.04) in 2010 and five times (aOR = 4.74) in 2015 (p < 0.001). Parity also increased the likelihood of overweight/obesity, women with parity of 6+ had more than 50%

*Factors Associated with Overweight and Obesity among Women Aged 15-49 Years… DOI: http://dx.doi.org/10.5772/intechopen.95909*

higher chances of being overweight/obese compared to those with parity of <2 in three periods, 2005, 2010 and 2015 (p < 0.05). Women currently in union were more likely to be overweight/obese compared to those never in union, 44% higher chances in 2005 (p < 0.05), 68% higher chance in 2010 (p < 0.001) and 65% higher chance in 2015 (p < 0.001) (**Table 3**).

Working increased odds of overweight/obesity compared to those not working, aOR = 1.23 in 2005, and aOR = 1.15 in 2015 (p < 0.05). Household ownership of radio and telephone did not show a statistically significant association with women's chances of being overweight or obese. Household ownership of television showed a significant increased likelihood of overweight/obesity in 2010 only (aOR = 1.25) (p < 0.05) with no significant likelihood in 2005 and 2015.

## **5. Discussion**

The aim of the study was to examine factors associated with overweight and obesity among women aged 15–49 years in Zimbabwe. Our study found that rural women were less likely to be overweight and obese than urban women. Similar findings were also reported by Neupane, Prakash and Doku 2015 who found obesity to be more prevalent in urban setups [5]. Neupane et al. [5] attributed this disparity to differences in lifestyle, dietary pattern and type of occupation. Women in rural areas tend to be involved in activities that call for their energy use such as farming, collecting firewood and fetching water and thus use up lots of calories. The study findings also reveal that women from richer households had higher odds of overweight and obesity than women from the poorest households. Similar findings were reported by Neupane et al. [5]. We found higher education and working status to be constantly associated with overweight/obesity in 2005 and 2015 and not in 2010/11. Studies elsewhere concur with current findings [18]. This could be related to the fact that these highly educated women are more likely to be working and more likely to come from richer households, and thus use energy saving devices at home to execute their daily domestic chores or can afford to employ domestic workers. In addition, some women tend to afford eating western food outlets at work which are perceived to be 'junk' and fatty food. However, the period 2010/11 has no statistically significant relationships as the period comes immediately after the economic challenges that occurred in 2008, spilling the effects into this period, such that education and working were overridden by other factors, thus diluting the relationship of these factors with overweight/obesity. Ownership of household assets was not associated with overweight or obesity except for television in 2010/11. This is contrary to other studies which found asset ownership such as radio and telephone to be associated with obesity. It is not surprising that a sedentary lifestyle has been observed to closely relate to time spent watching television as a leisure activity [13, 18]. Subsequently, reduced energy expenditure because of this leisure activity is closely associated with overweight and obesity.

Age was a constant predictor of overweight and obesity in all three surveys. With increasing age, women tend to be at higher odds ratios of becoming overweight and obese. Elsewhere in similar settings, the prevalence of overweight and obesity was also reported to be higher among older women [14, 19, 20]. Other studies associate obesity in old age to be characterised by high physical inactivity as well as the consumption of more energy-dense foods, which may result in overweight and obesity [14]. The current study found parity to be significantly associated with overweight/obesity. Similarly, several studies found multiparous women had the highest odds of being obese [7, 14] as well associated with the onset of higher retention of gestational weight gain [16, 22]. Marital status also emerged as a key factor in influencing overweight/obesity as women who were in a union or had been in a union had higher odds of overweight and obesity. Similar studies have found married women are more susceptible to being overweight or obese [25]. This could be due to childbearing as married women tend to have children, as the tradition implies marriage with childbearing and thus as parity increases in marriage, so the risk of overweight/obesity.


**7. Conclusion**

Tying it all up, it is important to note that the current state of affairs in the management of climate change is in part because of human frailties in the process of making policy that can respond effectively to this challenge. Most concerning in this regard is that sometimes humans are reluctant to take decisions that may interrupt established but destructive practices and adopt new and seemingly inconvenient


**Appendix A**

**Table A1.** Coding frameworks of communicative interaction and definition for each code.

**Table A1.** *Cont.*

Note. Definition for each code based on previous video-coding research [5,14,15,27].


**3.3.1 Description**

The cooperative was founded in 1968. The total area of forest is large at approximately 2,500 ha, including approximately 200 ha of planted forest33. The remaining area is covered by natural forest including secondary broadleaved forest that had been used for the production of fuel-wood or charcoal for a long period of time. When the cooperative was founded, a profit-sharing reforestation program was introduced to plant coniferous trees. In the 1960s and 1970s, the Forestry Agency and the prefectural government promoted the establishment of this type of forest producer cooperatives.


**7. Conclusions**

The financial sector is important in any economy, since it is the one that brings together those agents that have monetary resources to spare with the agents that need those resources. In Colombia, this sector is one of those that have marked the growth of the economy for several years; even more, at a time of global economic slowdown, it is the one that has definitely had very good profits. An example of this is the year 2016 in which despite the global recession this sector obtained an increase of 24.8% in its profits.

The Colombian banking sector emerges from the crises of the twentieth century, preparing itself to tackle the twenty-first century, through an organization that prioritizes the formation of financial groups of both national and foreign origin; this means that purchases and mergers have been the order of the day. In the last 15 years, the period of time of this investigation, there has been a great movement regarding the number of banks in the sector in each year. Although this period began with 24 banks in 2002, discounting the banks owned by the government and closing 2016 with this same number of banks do not mean that there was no movement in the intervening years.

**117**

*The Colombian Banking Sector: Analysis from Relative Efficiency*

The Santander Colombia, Scotiabank, HSBC Colombia, Helm, Union Colombiano, Tequendama, Bansuperior, Megabanco, Granahorrar, Colmena, and Conavi banks disappeared from the sector, either because they were purchased or because they merged. The Standard Chartered bank closed voluntarily and the bank Bankboston also settled voluntarily. The following banks entered: Corpbanca, Procredit Colombia, Bancamia, WWB, Coomeva, Finandina, Falabella, Pichincha Coopcentral, Santander de Negocios, Mundo Mujer, Multibank, and Bancompartir. To study this sector, the DEA methodology is perfectly adjusted since it is not necessary to predetermine the production function and a set of multiple entries and multiple outputs can be worked out to obtain a single indicator per bank and per

Within this investigation, it has been possible to establish that of the 13 bank s that entered the sector during the study period, and that were previously mentioned, 62% have obtained such good results that at least 90% of the years of existence have been efficient and when they are not, the indicator is above 90%. Overall, it can be determined that the average relative efficiency over the last 15 years of the Colombian banking sector is 86%, despite having raffled the first global financial crisis of this century and living a severe economic recession worldwide. The highest percentage of efficient banks is in 2014 (71%), for 2016 37% of

It was also established that one does not need to be the most important bank, nor the largest one in terms of assets, nor have they obtained the most voluminous profits, nor belong to the most powerful financial group, and nor have years of evolution, to be efficient. Additionally, not being a bank that is part of a very important financial group, it is efficient. Otherwise, so be a robust financial group, this does

The results also show that there is a large gap between the percentage of efficient and inefficient banks. This gap began in 2006 with 47% points of difference, which increases for 2008 and ends in the last year of the study with more than 50% points. On the other hand, the foreign banks have been more representative in the total of efficiency than the national banks; this situation only has a very slight change for

This research was carried out using public information to which there is free access, but it is evident that for a better approximation to the measurement of relative efficiency it would be very good to have access to information that in Colombia is considered as private. In other words, the directors of the different banks agree to

On the other hand, bank managers should take advantage of the conclusions reached to improve their performance, and if that were the case, the performance of

provide the information required to improve this study.

*DOI: http://dx.doi.org/10.5772/intechopen.84585*

period studied.

banks are inefficient.

the year 2016.

the whole group.

**8. Recommendations**

not mean that as a group, be efficient.

### *The Colombian Banking Sector: Analysis from Relative Efficiency DOI: http://dx.doi.org/10.5772/intechopen.84585*

*Accounting and Finance - New Perspectives on Banking, Financial Statements and Reporting*

The financial sector is important in any economy, since it is the one that brings together those agents that have monetary resources to spare with the agents that need those resources. In Colombia, this sector is one of those that have marked the growth of the economy for several years; even more, at a time of global economic slowdown, it is the one that has definitely had very good profits. An example of this is the year 2016 in which despite the global recession this sector obtained an

The Colombian banking sector emerges from the crises of the twentieth century,

preparing itself to tackle the twenty-first century, through an organization that prioritizes the formation of financial groups of both national and foreign origin; this means that purchases and mergers have been the order of the day. In the last 15 years, the period of time of this investigation, there has been a great movement regarding the number of banks in the sector in each year. Although this period began with 24 banks in 2002, discounting the banks owned by the government and closing 2016 with this same number of banks do not mean that there was no move-

**116**

**Figure 4.**

**Figure 3.**

**7. Conclusions**

*Behavior of efficient banks. Source: self-made.*

*Efficiency (%) of banks of the grupo aval. Source: self-made.*

increase of 24.8% in its profits.

ment in the intervening years.

The Santander Colombia, Scotiabank, HSBC Colombia, Helm, Union Colombiano, Tequendama, Bansuperior, Megabanco, Granahorrar, Colmena, and Conavi banks disappeared from the sector, either because they were purchased or because they merged. The Standard Chartered bank closed voluntarily and the bank Bankboston also settled voluntarily. The following banks entered: Corpbanca, Procredit Colombia, Bancamia, WWB, Coomeva, Finandina, Falabella, Pichincha Coopcentral, Santander de Negocios, Mundo Mujer, Multibank, and Bancompartir.

To study this sector, the DEA methodology is perfectly adjusted since it is not necessary to predetermine the production function and a set of multiple entries and multiple outputs can be worked out to obtain a single indicator per bank and per period studied.

Within this investigation, it has been possible to establish that of the 13 bank s that entered the sector during the study period, and that were previously mentioned, 62% have obtained such good results that at least 90% of the years of existence have been efficient and when they are not, the indicator is above 90%.

Overall, it can be determined that the average relative efficiency over the last 15 years of the Colombian banking sector is 86%, despite having raffled the first global financial crisis of this century and living a severe economic recession worldwide.

The highest percentage of efficient banks is in 2014 (71%), for 2016 37% of banks are inefficient.

It was also established that one does not need to be the most important bank, nor the largest one in terms of assets, nor have they obtained the most voluminous profits, nor belong to the most powerful financial group, and nor have years of evolution, to be efficient. Additionally, not being a bank that is part of a very important financial group, it is efficient. Otherwise, so be a robust financial group, this does not mean that as a group, be efficient.

The results also show that there is a large gap between the percentage of efficient and inefficient banks. This gap began in 2006 with 47% points of difference, which increases for 2008 and ends in the last year of the study with more than 50% points.

On the other hand, the foreign banks have been more representative in the total of efficiency than the national banks; this situation only has a very slight change for the year 2016.


**8. Cardiopulmonary effects of tramadol**

Acute pulmonary hypertension and right heart failure are the uncommon presentations reported in a young tramadol-overdosed patient [86]. Cardiopulmonary arrest was reported in some cases that had ingested more than 5 g of tramadol [8]. Higher doses of tramadol can block sodium channels and cause Brugada pattern in the ECG [11,47] which can be accompa‐ nied by ventricular dysrhythmias including ventricular fibrillation [11]. In a study on 479 tramadol-poisoned patients, up to 73% of the patients had ECG changes due to blockage of the sodium channels. Almost one-thirds of the patients had terminal 40 msec frontal plane axis deviation and one-fourth had QT prolongation (more than 0.44 sec) [47]. Some cases of right heart failure, resistant shock, asystole, hypotension (especially systolic), and sinus tachycardia have also been recorded [6,35,44,49]. Hypertension has also been reported. The least tramadol dose that has resulted in hypertension and agitation is 500 mg [49].

Eleven suspected cases of tramadol-related angioedema have been reported from Sweden. Involvement of the mouth/pharynx and upper respiratory system can progress to acute respiratory distress and airway obstruction [87]. Tramadol causes respiratory depression with less frequency in comparison with other opioids [28,57,88]. Renal failure is a probable risk factor for respiratory depression [28,89]. Tramadol overdose can cause respiratory depression; but in therapeutic oral doses, it does not cause respiratory complications. In a study on IV administration of 50 to 75 mg of tramadol, no significant changes were detected in the respiratory rate, respiratory volume per minute, and arterial PaO2 [90].


**4.1 The biological action of capsaicinoids**

The biological action of capsaicinoids is complex and multi-targeted mechanisms. The action involves, above all, the activation of peripheral nerve receptors

#### **Table 1.**

*Name, chemical structure, molecular formula, and CAS number of the major capsaicinoids.*

in the mucous membranes, by interactions of the capsaicinoids with the vanilloid transient receptor potential type-1 cation channels (TRPV1). These receptors are normally activated by temperatures between 37 and 45°C when opening the calcium channels and induce reflexes of burn sensation. However, when TRPV1 binds with the capsaicinoids, it causes these channels to open below 37°C and the burn sensation occurs at normal body temperature. This is why capsaicinoids are linked to the sensation of heat [20].

Furthermore, the interactions of the TRPV1 with capsaicin are strictly related to pain by nociceptor activation and the release of substance-P. Nociceptor is a nervous sensory receptor responsible for pain mechanisms in the human body [21]. Prolonged contact may cause nerve endings to be desensitized; however, it does not lead to a permanent desensitization state and can be reversed by discontinuing contact.

The capsaicin and dihydrocapsaicin content in the pepper spray solution is determinant for the irritant properties and the disabling effect of the spray. Thus, to evaluate the effectiveness of the disabling properties of the spray, the capsaicinoids concentration in the solution can be measured, particularly the capsaicin together with dihydrocapsaicin [14]. Obviously, the limits to this concentration must take into account the toxicity and security against injury. So, some connections among the concentration and the irritant effect must be evaluated.

The Scoville test, whose unit of measure is SHU, is a known form of evaluating the effect of pungency or blazing of the peppers. This method was developed in 1912 by Wilbor Scoville [22] giving a five-level scale for pungency: nonpungent (0–700 SHU), low pungency (700–3000 SHU), moderate pungency (3000–25,000 SHU), high pungency (25,000–70,000 SHU), and very high pungency (>80,000 SHU). However, the Scoville method is a taste organoleptic method made by a dilution series of the pepper extracts. It makes subjective responses and unreproducible results. Qualitative and quantitative information can be precisely obtained by modern instrumental chemical methods with many advantages [12, 23].


*Edited by Thomas Heinbockel*

*and Vonnie D.C. Shields*

Histology is the science of tissues and as such histology studies cells and tissues of organs using a variety of techniques. Histological techniques are used in different disciplines: research, teaching, and clinical applications. This book explores the research currently being carried out at the molecular, subcellular, and cellular levels, both in normal and pathological processes, from genetic mechanisms to intraand intercellular signaling. This book includes cutting-edge research reviews and descriptions of technological advances to modify bodily cells and tissues. Targeted at students and researchers in biological, medical, and related disciplines, this book will provide an overview of the work being done in this field, and will highlight gaps and areas that would benefit from further exploration. The book contains eight chapters in four sections and presents reviews in different areas of histology written by experts in their respective fields. Basic histology, cell biology, histopathology, and histological techniques are featured prominently as a recurring theme throughout the chapters. This book will be a most valuable resource for histologists, cell biologists, pathologists, and other scientists alike and contribute to the training of current and future biomedical scientists.

ISBN 978-1-78984-970-7

Histology

Published in London, UK © 2019 IntechOpen © tonaquatic / iStock


**6. Chemical recycling of poly(vinyl chloride)**

#### **6.1 Introduction**

Poly(vinyl chloride) main applications include food packaging, shoes, flooring ,pipes, clothing (leather-like material), ceiling tiles and multi-layered flooring and windowswindoors frames. It has a lifetime range of 5 years. PVC has the same density as that of PET, a property that made the separation prior to recycling of plastic wastes containing both polymers really difficult. The technique used for the efficient separation is X-ray fluorescence. The chlorine atoms of PVC are detected and the wastes are indicated for separation. Also IR sorting is widely used (Sadat-Shojai and Bakhshandeh, 2011).

In principle, PVC waste can be available in two ways: as a mixed plastic waste (MPW) fraction (with a rather low PVC content), or as a PVC-rich plastics fraction.

Fig. 7. The tonage of recycled PVC in EUROPE (Sadat-Shojai, Bakhshandeh, 2011).

As it is well-known PVC incineration is connected with problems arising from the high chlorine content of this polymer which yields large amounts of hydrochloric acid (HCl) during thermal decomposition, beside the possibility of formation of persistent and toxic compounds such as toxic dioxines and furans (Garcia et al., 2007; Ulutan, 1998; Ali and Siddiqui, 2005). In addition, when PVC wastes are fired in an incinerator, HCl corrodes the boiler tubes of the incinerator and other equipments. Therefore the steam pressure must be kept relatively low to prevent corrosion of the heat recovery boiler (Yoshioka et al., 1998). One of the best solutions to this problem may be neutralization of HCl with calcium carbonate (lime) and/or sodium hydroxide (caustic soda) to convert the released HCl to the salts. Also special filters can also be used to prevent problems related to atmospheric emissions during the combustion process (Machado et al., 2010).

Poly(vinyl chloride) main applications include food packaging, shoes, flooring ,pipes, clothing (leather-like material), ceiling tiles and multi-layered flooring and windowswindoors frames. It has a lifetime range of 5 years. PVC has the same density as that of PET, a property that made the separation prior to recycling of plastic wastes containing both polymers really difficult. The technique used for the efficient separation is X-ray fluorescence. The chlorine atoms of PVC are detected and the wastes are indicated for

In principle, PVC waste can be available in two ways: as a mixed plastic waste (MPW)

separation. Also IR sorting is widely used (Sadat-Shojai and Bakhshandeh, 2011).

Fig. 7. The tonage of recycled PVC in EUROPE (Sadat-Shojai, Bakhshandeh, 2011).

emissions during the combustion process (Machado et al., 2010).

As it is well-known PVC incineration is connected with problems arising from the high chlorine content of this polymer which yields large amounts of hydrochloric acid (HCl) during thermal decomposition, beside the possibility of formation of persistent and toxic compounds such as toxic dioxines and furans (Garcia et al., 2007; Ulutan, 1998; Ali and Siddiqui, 2005). In addition, when PVC wastes are fired in an incinerator, HCl corrodes the boiler tubes of the incinerator and other equipments. Therefore the steam pressure must be kept relatively low to prevent corrosion of the heat recovery boiler (Yoshioka et al., 1998). One of the best solutions to this problem may be neutralization of HCl with calcium carbonate (lime) and/or sodium hydroxide (caustic soda) to convert the released HCl to the salts. Also special filters can also be used to prevent problems related to atmospheric

fraction (with a rather low PVC content), or as a PVC-rich plastics fraction.

**6. Chemical recycling of poly(vinyl chloride)**

**6.1 Introduction**

Beside all above problems, net energy recovered by incineration of PVC-rich waste is not high enough to make it highly economic. As most hydrocarbon polymers, the calorific value from incineration of PVC in an ideal conditions is about 64 MJ/kg, compared to, for example, 17 MJ/kg for paper, or 16 MJ/kg for wood. Moreover, PVC is inherently difficult to combust, so that complete combustion of PVC-rich waste occurs at such high temperatures (>1700 K), that it is economically prohibitive (Xiong, 2010).

Therefore mechanical and/or chemical recycling of PVC plastic wastes seems the logical solution One usual approach for chemical recycling of PVC wastes is currently "thermal cracking" via hydrogenation, pyrolysis or gasification (Ryu et al., 2007; Williams and Williams, 1998; DeMarco et al., 2002; Kaminsky and Kim, 1999; Borgianni et al., 2002).

The main intermediate product of the thermal cracking is a polyene material that continues to degrade by evolution of aromatics and converts to a products which their composition will be strongly determined by processing variable such as type of atmosphere, temperature and residence time. In an inert atmosphere, the degradation products will be hydrochloric acid (HCl), gaseous and liquid hydrocarbons, and char, which among them HCl is a main product and can be reused either in vinyl chloride production, or in other chemical processes (Slapak et al., 1999).

In the case of manufacturing process of vinyl chloride, a gas purification unit must also be added to obtain high purity hydrogen chloride gas.

In a steam atmosphere at high temperatures, the hydrocarbon fraction will be converted into the some other products such as carbon monoxide, carbon dioxide and hydrogen. In a reported process bench-scale bubbling fluidized bed to investigate some processing parameters on the product outcome. The choice of type of bed material is essential for the product outcome, so that the use of catalytic inactive solid quartz as bed material results in the production of large amounts of char and tar, whereas the application of catalytic active material such as porous alumina results in a high conversion of PVC into the syngas. Moreover, according to their results, temperature has a large impact on the composition of the products, so that the carbon to gas conversion improved from about 70% at 1150 K to approximately 100% by increasing the reactor temperature to 1250 K. For chemical recycling of PVC, an increase in efficiency of dehydrochlorination process is usually attributed to the successful recycling (Wu et al., 2009).

It has been also reported that the emission of hydrogen chloride changes significantly with the oxides used indicating the chlorine fixing ability of oxides and also that utilization of poly(ethylene glycol) (PEG) can accelerate dehydrochlorination of PVC, so that at 210 °C for 1 h the dehydrochlorination degree was as high as 74% for PVC/PEG, while for PVC only 50%. Moreover, they demonstrated that for PVC/ PEG the decomposition of PVC shifted to lower temperatures compared with that of pure PVC, suggesting some interactions exist between PEG and PVC that caused the faster dehydrochlorination rate. According to their results, during this process, no waste byproducts such as KCl were produced, and satisfactory recyclability of PEG (10 cycles) can be obtained (Wu et al., 2009).

An alternative method to thermal process of dehydrochlorination is the rather easy process of dehydrochlorination under the influence of alkaline media to recover hydrochloric acid

Recent Advances in the Chemical Recycling

rigid PVC particles (Kameda et al., 2010).

electric arc furnace (Lee et al., 2007).

characterized (Matuschek et al., 2000).

**6.2 Mixed plastic recycling processes**

2008).

of Polymers (PP, PS, LDPE, HDPE, PVC, PC, Nylon, PMMA) 37

A new method consisting of copyrolysis of PVC with nitrogen compounds in biowaste to reduce the corrosive effects of the generated HCl was reported. The researchers studied the pyrolysis conditions between PVC and cattle manure via a statistical method and optimized conditions to provide the highest HCl reduction during PVC pyrolysis. They also applied the optimized conditions to a plastic mixture and then determined the quality of the obtained products. They concluded that the lowest heating rate, the highest reaction temperature (450°C), and the PVC:cattle manure ratio of 1:5 are the suitable conditions which provide the highest HCl reduction. However, according to their results the presence of manure decreases the oil yield of pyrolysis by about 17% (Duangchang,

PVC can also be chemically modified by nucleophilic substitution of chlorine atoms in its structure as it has been described: reactions of rigid PVC with various nucleophiles (Nu) such as iodide, hydroxide, azide, and thiocyanate in ethylene glycol as solvent. Such reactions lead to the substitution of Cl by Nu and finally elimination of HCl, resulting in the dehydrochlorination of the rigid PVC. According to their results, the dehydrochlorination yield increased with an increasing nucleophiles concentration, resulting in a maximum substitution at high nucleophiles amounts. Moreover, when ethylene glycol was replaced by diethylene glycol the dehydrochlorination was found to be accelerated, which may be due to the higher compatibility of diethylene glycol with PVC, making it easier to penetrate the

Several different technologies based on depolymerization and repolymerization processes have been developed for chemical recycling of PVC, which unfortunately the most of them

PVC waste was used in a research wich carried out for the recycling electric arc furnace dust by heat treatment with PVC. The entire process aimed to recover the zinc, lead, and cadmium from the dust and was adjusted so that the residual dust can be injected into the

There are many reports, where thermoanalytical methods especially coupled methods with gas analysis systems, can deliver suitable information for the recycled PVC that needs to be

Recovinyl-Co (UK) deals with post-consumer PVC to reproduce two grades via mechanical recycling. Due to its structure and composition, PVC can easily be mechanically recycled in order to obtain good quality recycling material. Careful and proper sorting is of crucial

A pyrolytic process which has proven to be successful for plastic solid waste rich in PVC, is the Akzo process (Netherlands). With a capacity of 30 kg/h, this fast pyrolysis process is based on a circulating fluidised bed system (two reactors) with subsequent combustion. Input to the process is shredded mixed waste including a high percentage of PVC waste. The main outputs consist of HCl, CO, H2, CH4 and, depending on the feedstock

are more expensive than the mechanical recycling (LaMantia, 1996).

importance for the optimal recycling of PVC (Recovinyl, 2008).

composition, other hydrocarbons and fly ash (Tukker et al., 1999).

with a possibility that the degradation of PVC by oxygen oxidation in an aqueous alkaline solution to produce various carboxylic acids (Brown, 2002).

Some researchers demonstrated that dehydrochlorination of flexible-PVC occurred first and followed then by oxidation. They reported that the major products were oxalic acid, a mixture of benzenecarboxylic acids, and CO2. However, the chlorine content could also be recovered in the form of HCl by adjusting the reaction conditions such as alkali concentration (Yoshioka et al., 1998).

Among various methods of thermal cracking, pyrolysis is a more well-known procedure in the chemical recycling of PVC. The process of pyrolysis, which takes places at 500-900°C without any oxygen, is a very suitable recycling method especially in the case of mixed plastic wastes (PVC recycling, 2005). In a typical process, a PVC-rich waste can be pyrolysed to hydrocarbons (oil), soot, hydrochloric acid, chlorinated hydrocarbons, etc., which hydrochloric acid needs to be removed from the pyrolysis gas although this removal process can result in the formation of toxic dioxins in some stages. The main end product of pyrolysis is, however, oil industry (Sadat-Shojai and Bakhshandeh, 2011).

One main problem connected with pyrolysis of PVC and mixed plastics containing PVC materials is corrosion of the process equipment (e.g., pyrolysis reactor and piping) mainly by the formation of the acid gas (HCl). Moreover, many petrochemical specifications limit the amounts of halogens (appeared in the forms of hydrogen chloride and chloro organic compounds) to a very low range in the gas and oil derived from plastic waste. Therefore in the case of mixed plastic wastes (uneconomic to separate to a single polymer) with a low PVC content, the conventional chemical recycling is frequently used only for a waste stream in which the PVC content is less than 30% (for example, the multiple material products) (Duangchang, 2008).

So far, several solutions to such problems have been proposed which some of them have already been put into practical use. For example, milling of PVC with CaO can be an effective way to extract Cl from the waste (Tongamp et al., 2008).

An attempt has also been made to develop a process for recovering metals from alloywastes by using a mechanochemical reaction consisting of a co-grinding alloy and PVC waste, followed by washing with water and filtration (Zhang et al., 2007).

Currently, the NKT-Watech pyrolysis process in Europe uses another two-step pyrolysis of PVC wastes in a stirred vessel. Calcium carbonate and filler are used to react with liberated HCl and produce calcium chloride. Then at the increased temperature, the polymer chains break down which produce a solid coke residue. Finally, the residual calcium chloride can be treated to make it suitable for selling (Scheirs, 2010).

Alternative approach is pre-treatment of mixed plastic waste by removing PVC and other halogenated plastics from the feed. Such pre-treatment consists of a dilution of the wastes having excessive chlorine content with less chlorine-containing or chlorine-free polymer mixture. It is also common to dilute the chlorine-containing hydrocarbon feed with chlorinefree petroleum fractions coming from refineries. Another possibility, as a less expensive and more acceptable process, is thermal dehalogenation which takes place either in a liquid or in a fluidized bed pyrolysis.

with a possibility that the degradation of PVC by oxygen oxidation in an aqueous alkaline

Some researchers demonstrated that dehydrochlorination of flexible-PVC occurred first and followed then by oxidation. They reported that the major products were oxalic acid, a mixture of benzenecarboxylic acids, and CO2. However, the chlorine content could also be recovered in the form of HCl by adjusting the reaction conditions such as alkali

Among various methods of thermal cracking, pyrolysis is a more well-known procedure in the chemical recycling of PVC. The process of pyrolysis, which takes places at 500-900°C without any oxygen, is a very suitable recycling method especially in the case of mixed plastic wastes (PVC recycling, 2005). In a typical process, a PVC-rich waste can be pyrolysed to hydrocarbons (oil), soot, hydrochloric acid, chlorinated hydrocarbons, etc., which hydrochloric acid needs to be removed from the pyrolysis gas although this removal process can result in the formation of toxic dioxins in some stages. The main end product of

One main problem connected with pyrolysis of PVC and mixed plastics containing PVC materials is corrosion of the process equipment (e.g., pyrolysis reactor and piping) mainly by the formation of the acid gas (HCl). Moreover, many petrochemical specifications limit the amounts of halogens (appeared in the forms of hydrogen chloride and chloro organic compounds) to a very low range in the gas and oil derived from plastic waste. Therefore in the case of mixed plastic wastes (uneconomic to separate to a single polymer) with a low PVC content, the conventional chemical recycling is frequently used only for a waste stream in which the PVC content is less than 30% (for example, the multiple material products)

So far, several solutions to such problems have been proposed which some of them have already been put into practical use. For example, milling of PVC with CaO can be an

An attempt has also been made to develop a process for recovering metals from alloywastes by using a mechanochemical reaction consisting of a co-grinding alloy and PVC

Currently, the NKT-Watech pyrolysis process in Europe uses another two-step pyrolysis of PVC wastes in a stirred vessel. Calcium carbonate and filler are used to react with liberated HCl and produce calcium chloride. Then at the increased temperature, the polymer chains break down which produce a solid coke residue. Finally, the residual calcium chloride can

Alternative approach is pre-treatment of mixed plastic waste by removing PVC and other halogenated plastics from the feed. Such pre-treatment consists of a dilution of the wastes having excessive chlorine content with less chlorine-containing or chlorine-free polymer mixture. It is also common to dilute the chlorine-containing hydrocarbon feed with chlorinefree petroleum fractions coming from refineries. Another possibility, as a less expensive and more acceptable process, is thermal dehalogenation which takes place either in a liquid or in

pyrolysis is, however, oil industry (Sadat-Shojai and Bakhshandeh, 2011).

effective way to extract Cl from the waste (Tongamp et al., 2008).

be treated to make it suitable for selling (Scheirs, 2010).

waste, followed by washing with water and filtration (Zhang et al., 2007).

solution to produce various carboxylic acids (Brown, 2002).

concentration (Yoshioka et al., 1998).

(Duangchang, 2008).

a fluidized bed pyrolysis.

A new method consisting of copyrolysis of PVC with nitrogen compounds in biowaste to reduce the corrosive effects of the generated HCl was reported. The researchers studied the pyrolysis conditions between PVC and cattle manure via a statistical method and optimized conditions to provide the highest HCl reduction during PVC pyrolysis. They also applied the optimized conditions to a plastic mixture and then determined the quality of the obtained products. They concluded that the lowest heating rate, the highest reaction temperature (450°C), and the PVC:cattle manure ratio of 1:5 are the suitable conditions which provide the highest HCl reduction. However, according to their results the presence of manure decreases the oil yield of pyrolysis by about 17% (Duangchang, 2008).

PVC can also be chemically modified by nucleophilic substitution of chlorine atoms in its structure as it has been described: reactions of rigid PVC with various nucleophiles (Nu) such as iodide, hydroxide, azide, and thiocyanate in ethylene glycol as solvent. Such reactions lead to the substitution of Cl by Nu and finally elimination of HCl, resulting in the dehydrochlorination of the rigid PVC. According to their results, the dehydrochlorination yield increased with an increasing nucleophiles concentration, resulting in a maximum substitution at high nucleophiles amounts. Moreover, when ethylene glycol was replaced by diethylene glycol the dehydrochlorination was found to be accelerated, which may be due to the higher compatibility of diethylene glycol with PVC, making it easier to penetrate the rigid PVC particles (Kameda et al., 2010).

Several different technologies based on depolymerization and repolymerization processes have been developed for chemical recycling of PVC, which unfortunately the most of them are more expensive than the mechanical recycling (LaMantia, 1996).

PVC waste was used in a research wich carried out for the recycling electric arc furnace dust by heat treatment with PVC. The entire process aimed to recover the zinc, lead, and cadmium from the dust and was adjusted so that the residual dust can be injected into the electric arc furnace (Lee et al., 2007).

There are many reports, where thermoanalytical methods especially coupled methods with gas analysis systems, can deliver suitable information for the recycled PVC that needs to be characterized (Matuschek et al., 2000).

#### **6.2 Mixed plastic recycling processes**

Recovinyl-Co (UK) deals with post-consumer PVC to reproduce two grades via mechanical recycling. Due to its structure and composition, PVC can easily be mechanically recycled in order to obtain good quality recycling material. Careful and proper sorting is of crucial importance for the optimal recycling of PVC (Recovinyl, 2008).

A pyrolytic process which has proven to be successful for plastic solid waste rich in PVC, is the Akzo process (Netherlands). With a capacity of 30 kg/h, this fast pyrolysis process is based on a circulating fluidised bed system (two reactors) with subsequent combustion. Input to the process is shredded mixed waste including a high percentage of PVC waste. The main outputs consist of HCl, CO, H2, CH4 and, depending on the feedstock composition, other hydrocarbons and fly ash (Tukker et al., 1999).

Recent Advances in the Chemical Recycling

**6.3 Mixed PVC wastes World inititives**

(Shin et al., 1998).

(Yoshioka et al., 2000).

of Polymers (PP, PS, LDPE, HDPE, PVC, PC, Nylon, PMMA) 39

depending on the reaction conditions and the alkali concentration. The maximum yield of oxalic acid was 45%and 42% of the chlorine content could be recovered in the form of HCl

Oxidative degradation of rigid-PVC pellets (R-PVC) with oxygen was carried out in 1-25 mol/kg-H2O (m) NaOH solutions, at 150-260°C and PO2 of 1-10 MPa in order to investigate the chemical recycling of PVC materials. The apparent rate of oxidative degradation of R-PVC progressed as a zero order reaction, and the apparent activation energy was 38.5 kJ/mol. The major products were oxalic acid, a mixture of benzene-carboxylic acids, and CO2. The tin in R-PVC was extracted completely. The possibility of converting PVC materials into raw materials such as carboxylic acids by chemical recycling is reported

Regarding the chemical recycling of mixed plastic wastes with a PVC content of up to several percent, the following initiatives seem to be most realistic for the coming 5 years: **Texaco gasification process** (NL, pilot in the US), Polymer cracking process (consortium project, pilot), **BASF conversion process** (D, pilot but on hold) **Use as reduction agent in blast furnaces** (D, operational), **Veba Combi Cracking process** (D, operational but to be closed by 2000**), Pressurized fixed bed gasification of SVZ** (D, operational). A brief report

**BP Chemicals** has led promotion of Polymer Cracking technology for feedstock recycling since its beginnings in the early 1990's. Since the challenge of recycling of plastics is industry wide, support has been provided by a Consortium of European companies to develop the

on these initiatives is presented below (Sadat-Shojai and Bakhshandeh, 2011).

Fig. 9. The BP polymer cracking process (Tukker et al., 1999).

The NRC process is another successful pyrolysis scheme. This process is based on the pyrolysis with subsequent metal extraction technology. The aim is to produce purified calcium chloride instead of HCl. The input to the process is PVC waste (cables, flooring, profiles, etc.). No other plastic solid waste type is fed to the processing, which results in calcium chloride, coke, organic condensate (for use as fuels) and heavy metals for metal recycling, as products (Al-Salem et al., 2009).

The NTK process, depicted below (fig. 8), is a very successful recycling process. The process is based on an initial pre-treatment step that involves separating light plastics (PP, PE, etc.) and other materials, e.g. wood, sand, iron, steel, brass, copper and other metallic pollutants. The PSW waste is then fed to a reactor at a low pressure (2–3 bars) and a moderate temperature (375°C). The process emits neither dioxins, chlorine, metals nor plasticizers. Also, there are no liquid waste streams in the process since all streams are recycled within the system. There is a small volume of carbon-dioxide gas formed by the reaction between lime/limestone and hydrogen chloride. Mixed PVC building waste containing metals, sand, soil, PE, PP, wood and rubber waste have been successfully treated (Al-Salem et al., 2009).

The gasification into high calorific value fuel gas obtained from PVC was also reported by Borgianni et al., 2002.

Fig. 8. NTK process diagram (Tukker et al., 1999).

Chemical recycling of PVC has been also attempted. Most of the proposed processes use the rather easy dehydrochlorination of PVC either under the influence of heat of alkaline media. The oxidative degradation of PVC by molecular oxygen in aqueous alkaline solution at temperatures between 150 and 260 oC with oxygen pressures of 1–10 MPa has been reported. The main products are oxalic acid and carbon dioxide, their yield

The NRC process is another successful pyrolysis scheme. This process is based on the pyrolysis with subsequent metal extraction technology. The aim is to produce purified calcium chloride instead of HCl. The input to the process is PVC waste (cables, flooring, profiles, etc.). No other plastic solid waste type is fed to the processing, which results in calcium chloride, coke, organic condensate (for use as fuels) and heavy metals for metal

The NTK process, depicted below (fig. 8), is a very successful recycling process. The process is based on an initial pre-treatment step that involves separating light plastics (PP, PE, etc.) and other materials, e.g. wood, sand, iron, steel, brass, copper and other metallic pollutants. The PSW waste is then fed to a reactor at a low pressure (2–3 bars) and a moderate temperature (375°C). The process emits neither dioxins, chlorine, metals nor plasticizers. Also, there are no liquid waste streams in the process since all streams are recycled within the system. There is a small volume of carbon-dioxide gas formed by the reaction between lime/limestone and hydrogen chloride. Mixed PVC building waste containing metals, sand, soil, PE, PP, wood and rubber waste have been successfully treated (Al-Salem et al., 2009).

The gasification into high calorific value fuel gas obtained from PVC was also reported by

Chemical recycling of PVC has been also attempted. Most of the proposed processes use the rather easy dehydrochlorination of PVC either under the influence of heat of alkaline media. The oxidative degradation of PVC by molecular oxygen in aqueous alkaline solution at temperatures between 150 and 260 oC with oxygen pressures of 1–10 MPa has been reported. The main products are oxalic acid and carbon dioxide, their yield

recycling, as products (Al-Salem et al., 2009).

Fig. 8. NTK process diagram (Tukker et al., 1999).

Borgianni et al., 2002.

depending on the reaction conditions and the alkali concentration. The maximum yield of oxalic acid was 45%and 42% of the chlorine content could be recovered in the form of HCl (Shin et al., 1998).

Oxidative degradation of rigid-PVC pellets (R-PVC) with oxygen was carried out in 1-25 mol/kg-H2O (m) NaOH solutions, at 150-260°C and PO2 of 1-10 MPa in order to investigate the chemical recycling of PVC materials. The apparent rate of oxidative degradation of R-PVC progressed as a zero order reaction, and the apparent activation energy was 38.5 kJ/mol. The major products were oxalic acid, a mixture of benzene-carboxylic acids, and CO2. The tin in R-PVC was extracted completely. The possibility of converting PVC materials into raw materials such as carboxylic acids by chemical recycling is reported (Yoshioka et al., 2000).


*4.2.2 Tensioning of medial structures*

As described by Krackow et al. [17], when the MCL is attenuated and there is a residual medial laxity, the authors suggest tightening of the medial structures. The advancement of the MCL from the epicondyle or a division and imbrication in order to tighten, it can be performed.

### *4.2.3 The fibular nerve dilemma*

Fibular nerve palsy (FNP) is a feared complication after valgus TKA. The reported incidence of FNP after valgus TKA in the literature ranges between 0.3% and 9.5%. Injury of the Fibular nerve can be caused by indirect damage due to stretch or ischemia after correction, or by direct injury due to laceration during lateral soft tissue release. As FNP has serious consequences, some orthopedic surgeons advocate to prevent this complication by a concomitant fibular nerve release (FNR). Due to the limited number of studies investigating FNR, no consensus has yet been reached on the value and indication of the procedure. A systematic review demonstrated no significant differences in FNP rate between valgus TKA with and without FNR (2.4% vs 2.1%) [18]. Therefore, the authors of this chapter do not recommend the routine use of FNR.

#### **4.3 Bone resection**

Valgus deformity has particularities that need to be recognized so that bone cuts can be made properly. In most cases, the origin of the deformity is located in the distal femur, as opposed to the varus deformity. Lateral condyle hypoplasia is frequently present and needs to be recognized, as it directly interferes with several parameters of femoral bone cuts. A smaller number of cases may have lateral tibial plateau sinking, either due to fracture sequelae or in very advanced cases with deformity > 20° and MCL insufficiency.

Extra-articular deformities such as external torsion of the tibia and remodeling with valgus deviation of the femoral and tibial shafts may also coexist [19].

### *4.3.1 Tibial resection*

We recommend that the first bone cut is the tibial one, parallel to the ground. The main reason is that we can use the tibia as a parameter for the posterior cut of the femur through the gap balancing technique, in which the cut is performed parallel to the tibial cut with the knee at 90° under symmetrical soft tissue tension. This is

## *Total Knee Arthroplasty in Valgus Knee DOI: http://dx.doi.org/10.5772/intechopen.109573*

important because, due to hypoplasia of the lateral condyle, we cannot rely on the classic parameter of 3° of external rotation in relation to the posterior condyles, which will be discussed later.

A marked valgus deformity of the tibial diaphysis is frequently observed in valgus knee, which makes it impossible to use an intramedullary guide for the tibia in most cases. Therefore, we recommend the use of the extramedullary guide for all cases. In addition, tibial cutting guides are usually sided (left or right). In these cases, it will be necessary to use the guide on the opposite side. Another important detail of this step is the amount of bone to be cut. Traditionally, in varus knee prosthesis, 9–10 mm of bone can be removed using the healthy plateau as a parameter. However, the healthy tibial plateau in valgus knee is the medial plateau. It turns out that the medial plateau is 3 mm more distal than the lateral plateau. Therefore, we must discount this 3 mm when making the cut, otherwise we will inadvertenltly cut more tibia than ideal. Therefore, make the tibial cut 6 or 7 mm from the medial plateau.

## *4.3.2 Femural resection*

Next, we will make the distal cut of the femur. Instead of the 7° of valgus traditionally used in varus knees, we used 5° in the distal cut of the femur, in order not to under-correct the deformity. The surgeon may also choose to use the exact difference

#### **Figure 1.**

*Tips and tricks for appropriate bone resection in valgus TKA. (A) Weight-bearing knee radiography demonstrating lateral condyle hypoplasia and the adjusted entry point for IM guide at the medial condyle (red arrow), in the prolongation of the anatomical axis of the femur; (B) determination of the rotation of the femoral component by the Whiteside line (yellow), parallel to the transepicondylar axis. Do not use the support guide on the posterior condyles; (C) When determining the rotation of the tibial component, 1 centimeter medial to the TTA, the less experienced surgeon with the Keblish approach must be careful because the tibia is being viewed "in a mirror."*

measured between the anatomical and mechanical axis of the femur in the preoperative panoramic X-ray. Caution should be taken with the entry point of the intramedular guide. Because of hypoplasia of the lateral femoral condyle, the entry point must be medialized, sometimes not above the intercondylar notch as usually done in varus cases, but in the medial femural condyle.

Regarding the adjustment of the femoral rotation, one more point of attention: The existence of hypoplasia of the lateral femoral condyle is very common. Therefore, the use of a guide based on the posterior condylar line will incur in excessive internal rotation of the femoral component. If the technique used is measured resection that considers the anatomical points, the correct way is to base it on the trans-epicondylar axis or on the Whiteside line. An alternative, as already described, is to use the gap balancing technique in this step.

**Figure 1** brings some tips and tricks to keep in mind as they are common causes of errors.


Intra-operative Endoscopy

*Endoscopy in Small Bowel Diseases*

[30] Lee JH, Cho CJ, Park YS, Ahn JY, Kim DH, Na HK, et al. EUS-guided 22-gauge fine needle biopsy for the diagnosis of gastric subepithelial tumors larger than 2 cm. Scand J Gastroenterol

[Internet]. 2016;51(4):486-493.

[31] de Moura DTH, McCarty TR, Jirapinyo P, Ribeiro IB, Flumignan VK, Najdawai F, et al. EUS-guided fineneedle biopsy sampling versus FNA in the diagnosis of subepithelial lesions: a large multicenter study. Gastrointest Endosc [Internet]. 2020 Jul;92(1):108- 119.e3. Available from: https://doi. org/10.1016/j.gie.2020.02.021

[32] Facciorusso A, Sunny SP, Del Prete V, Antonino M, Muscatiello N. Comparison between fine-needle biopsy and fine-needle aspiration for EUS-guided sampling of subepithelial lesions: a meta-analysis. Gastrointest Endosc. 2020 Jan;91(1):14-22.e2.

00365521.2015.1052095

Available from: https://doi.org/10.3109/

**88**

**91**

lesions.

**Chapter 6**

**Abstract**

Diseases

*and Houssem Ammar*

era of deep enteroscopy.

**1. Introduction**

Peutz-Jeghers syndrome, Crohn's disease

Role of Intraoperative Endoscopy

With the advances in the endoscopic technology, most of the small bowel diseases are being diagnosed by capsule endoscopy and device assisted enteroscopy. However, there are many clinical situations such as small bowel obstruction, foreign body impaction were these advanced endoscopic procedures cannot be performed. In such cases, intraoperative endoscopy plays a vital role in the management of these small bowel diseases. Intraoperative endoscopy is also very useful in identification of the site of obscure gastrointestinal bleeding in difficult cases. Moreover, capsule endoscopy and device assisted enteroscopy are expensive procedures and not readily available at all medical centers especially in low income countries. On the other hand, intraoperative endoscopy can be easily performed by conventional gastroscope and colonoscope. In this chapter, we have discussed the indications, techniques, outcomes and complications of intraoperative endoscopy in the current

**Keywords:** intraoperative endoscopy, enteroscopy, inflammatory bowel disease,

Traditionally, intraoperative endoscopy (IOE) was the only means for the visualization of small bowel mucosal lesions not accessible to upper gastrointestinal endoscopy and colonoscopy. However, with the advances in abdominal imaging and the advent of capsule endoscopy (CE), the use of IOE diminished. A comparative study of CE and IOE found the sensitivity and specificity of CE to be 95% and 75%, respectively [1]. Hence, most guidelines recommend CE for detection of suspected small bowel lesions in patients with obscure gastrointestinal (GI) bleed. However, the main disadvantage of CE was inability to perform therapeutic procedures. Subsequently, the device assisted enteroscopy (DAE), namely, spiral endoscopy, double balloon enteroscopy (DBE) and single balloon enteroscopy (SBE) was developed which has brought paradigm shift in the treatment of small bowel mucosal diseases. DAE allows visualization, biopsy and removal of the small bowel mucosal

However, IOE is still an indispensable tool for the evaluation and treatment of small bowel diseases in special situations and institutions with lack of DAE

*Rahul Gupta, Arvind K. Singh, Jyoti Gupta*

in the Management of Small Bowel


**4. Diagnosis: risks, threats, and vulnerability**

Tulum suffers from two potential threats hydrometeorological events (hurricanes and floods) and anthropogenic threats caused by pressure from tourism and population growth. From a strictly environmental point of view, Tulum cannot grow due to the characteristics of its soil and subsoil (karstic soil, mangroves, and underground rivers). All growth brings with it conflicts between the environment and urbanization. The natural system is highly vulnerable: "Furthermore, the mangrove, like the reefs, is altered by the action of hydrometeorological phenomena, since during its action, salinity increases and exerting greater environmental pressure on this species" [13].


*2.1. Experiment Using O*ff*-line Rolling Simulator*

In order to understand the thermal histories of the rod and plate with area, a simulator for the hot rolling process was used. The rolling simulator mainly consisted of a couple of rolls, guide for workpiece, roller conveyor, and reheating furnace, as shown in Figure 3. Prior to the hot rolling test, the workpiece with four thermocouples was placed in a box-type reheating furnace. An oxide scale formation on the surface of a workpiece was suppressed using nitrogen gas in the reheating furnace. When the workpiece was heated to the final temperature of 1150 ◦C, it stayed for an additional 20 min for a homogenization. Then, the workpiece was withdrawn from the reheating furnace and rolled without lubrication.

For the flat rolling test, a rectangular plate of 150 × 30 mm was selected for an initial workpiece and it was hot-rolled using the flat rolls, as shown in Figure 4a. The round specimen with a diameter of 50 mm was also hot-rolled using the oval groove, as shown in Figure 4b. The ductile casting iron (DCI) rolls of 400 mm in diameter were rotated at a speed of 10 RPM. Plain low carbon steel, AISI 1020, was used and the analyzed chemical composition in weight percent was Fe-0.2C-0.4Mn. The specific operating conditions are summarized in Table 1. The caliber roll was designed to have a reduction of area (RA) per pass of 20%, which is a general rolling condition in hot rod rolling industries. RA per pass was calculated using the following equation:

$$RA = \frac{A\_0 - A\_f}{A\_0} \times 100 (\%) \tag{1}$$

where *Ao* and *Af* are the areas of initial and final cross section, respectively. The reduction of height of a plate during flat rolling was selected to have a same average effective strain with the rod during shape rolling. The average effective strain of a rod during shape rolling was calculated using the model proposed by Lee et al. [24] that is based on the equivalent rectangle approximation method, which transforms a non-rectangular cross section shape into a rectangular shape, and the average effective strain (ε*p*) is calculated as follows:

$$
\varepsilon\_p = \left[\frac{2}{3} (\varepsilon\_1^2 + \varepsilon\_2^2 + \varepsilon\_3^2)\right]^{1/2} = \frac{2}{\sqrt{3}} \varepsilon\_2 \left[1 + \left(\frac{\varepsilon\_1}{\varepsilon\_2}\right)^2 + \left(\frac{\varepsilon\_1}{\varepsilon\_2}\right)\right]^{1/2} \tag{2}
$$

where ε1 and ε2 are simply obtained by calculating the reduction ratio of width and height in equivalent rectangle approximation, respectively. In case of plate rolling, the ratio of ε1 and ε2 is very small in nature, and thus the average effective strain is represented as follows:

$$
\varepsilon\_p = \frac{2}{\sqrt{3}} \varepsilon\_2 \tag{3}
$$

where ε2 is calculated by the reduction ratio of height as follows:

$$\kappa\_2 = \ln \left( \frac{H\_i}{H\_f} \right) \tag{4}$$

where *Hi* and *Hf* are the height of initial and final plate, respectively. The final height of a plate was chosen using Equation (3), as shown in Figure 4a.

Figure 4a,b shows the schematic description of the measurement points of temperature using thermocouples in workpieces. Four points were measured at the each process using chromel–alumel (K-type) thermocouples with an Inconel sheath. The response time of the thermocouple was improved by decreasing its diameter; therefore, 1.0 mm diameter thermocouple was selected, although it was easily breakable during the experiment under the severe working conditions such as the hot rolling test. Thermocouples were embedded in the 70 mm deep hole drilled from the tail end of a workpiece, as shown in Figure 4c, to easily handle the workpiece during the rolling test and to minimize the thermal disturbance on the surface of a workpiece [23]. One thermocouple was located at the center, and three of them were placed as close the surface as possible, i.e., the thermocouples of the surface were located at 1.5 mm from the outer surface. A multi-channel data recorder gathered temperature data during the test with a sampling time of 0.2 s. Because the thermocouples that are embedded in the surface region were easy to burn out during the hot rolling test, each test was repeated three times to ensure reliability and repeatability.

**Figure 3.** Schematic description of the off-line hot rolling simulator in this study.

**Figure 4.** *Cont*.

**Figure 4.** Schematic description showing the roll design and the measurement points of temperature using thermocouples: (**a**) cross section of flat rolling, (**b**) cross section of rod rolling, and (**c**) cross section of the longitudinal direction of the rod.

**Table 1.** Process parameters of hot rolling test using the off-line simulator in this experiment.