**1. Introduction**

The unique features of the Tibetan Plateau (TP), such as its complex terrain formed by high mountains and valleys, dramatic changes in the atmospheric environment, differences in atmospheric composition, and unique geographical climate and circulation characteristics, form different atmospheric optical turbulence characteristics over the TP from those of low-elevation plain regions [1]. The TP is the major energy source providing sensible and latent heat fluxes to the atmosphere depending on the turbulence processes that occur during land–atmosphere interactions for mass and energy exchanges [2]. The combined effect of the complex terrain of the TP and the heat source enables the development of turbulence in the middle and upper atmosphere over the region.

Strong Asian summer monsoon circulations exist above the TP, including deep convective activities and planetary-scale anticyclones, such as the South Asian high, SAH (hereinafter referred to as the Asian summer monsoon anticyclone (ASMA)) [3,4]. The ASMA is stable and strong in the vertical direction at 70–300 hPa and occupies almost

**Citation:** Zhang, K.; Wang, F.; Weng, N.; Wu, X.; Li, X.; Luo, T. Optical Turbulence Characteristics in the Upper Troposphere–Lower Stratosphere over the Lhasa within the Asian Summer Monsoon Anticyclone. *Remote Sens.* **2022**, *14*, 4104. https://doi.org/10.3390/ rs14164104

Academic Editor: Michael E. Gorbunov

Received: 16 July 2022 Accepted: 18 August 2022 Published: 21 August 2022

**Publisher's Note:** MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

the entire upper troposphere–lower stratosphere (UTLS) area [5], which is closely related to plateau land-atmosphere heat transfer [6,7]. The ASMA is closely related to frequent convective activities, particularly during the period from June to September. The geographic location of the ASMA center varies over periods of a few days or even over longer periods [8]. The coupling of atmospheric circulation and convection that prevails over the TP during the summer results in the frequent occurrence of convective activities in the lower atmosphere. Less details are known about the influence of the ASMA on the thermodynamic structure of the atmosphere in the stratosphere.

The strong convective activities and ASMA on the TP affect the atmospheric components and their distribution in the UTLS of the Asian monsoon region by uplifting the lower atmosphere [9–11]. A turbulent atmosphere is an important transport medium in stratosphere–troposphere exchange (STE). First, convective injections can impact air and aerosol transport from the atmospheric boundary layer (ABL) to the UTLS [12,13]. In contrast, deep convection activities carry low concentrations of ozone and high concentrations of water vapor into the ASMA, which remain inside the ASMA for a period of time, and they are relatively isolated from the outside air and subsequently uploaded to the UTLS [14,15]. Moreover, the vertical distribution of atmospheric turbulence is one of the factors that must be inevitably considered in the astronomical site testing of ground-based astronomical optical telescopes [16]. Atmospheric turbulence is the main reason for the serious degradation of optical imaging quality, and it is also an important indicator for comparing the quality of astronomical sites [17,18].

TP has garnered significant attention as the third pole of the Earth. In the past three decades, researchers have conducted several atmospheric scientific experiments on the TP combined with numerical simulations. Some studies have been conducted mainly on the structure of the ABL over the TP and its surrounding areas, including studies on the occurrence and development of weather systems and the impact of the TP on atmospheric circulation [19,20].

However, the relationship between the optical turbulent structure and meteorological parameters in the UTLS has rarely been studied [21]. The results of observations and numerical simulations obtained in recent years indicate that the ASMA region surrounding Lhasa as the core area is an extremely important area, through which surface pollutants enter the global stratosphere. The transport of these materials into the stratosphere through atmospheric turbulence has important effects on the global climate and environment through microphysical, chemical, and radiative processes [22–24].

At present, most research on atmospheric turbulence structure in UTLS over the TP are studied based on model simulations or reanalysis, because in situ observed turbulent data are scarce. In consequence, details regarding the structure of atmospheric turbulence in the UTLS, STE process, and characteristics of atmospheric composition budgets are still lacking. The widely used measurement techniques of high-altitude atmospheric turbulence characteristics are roughly divided into two categories. One is the path-averaged turbulence intensity measurement technique, such as the optical triangulation method [16,25] and extension technology [26]; the other is the localized turbulence intensity measurement technique, such as the micro-thermal pulsation method. In situ turbulent measurement based on radiosonde is a simple but very reliable, effective, high-precision, and commonly used atmospheric detection method, particularly the micro-thermal sensors mounted on the balloon, which realizes the measurement of atmospheric turbulence in UTLS [27–30]. As such, not only basic atmospheric parameters such as temperature and humidity can be measured, but also the value of atmospheric refractive index structure constant *C*2 *n* in the middle and upper atmosphere is obtained simultaneously, which is an important parameter to measure turbulence intensity. This study analyzes the reasons for the large short-term fluctuations of *C*2 *n* in the Lhasa region from the aspects of atmospheric turbulence parameters, the ASMA, high-pressure activities at 500 hPa, and atmospheric circulation.


Preface

The respiratory system, as a port of entry, plays an important role in the health and disease of individuals. Understanding respiratory physiology can aid practitioners in diagnosing the cause of respiratory symptoms. Physiological factors should be considered before interpreting any medical condition. Clinical application of physiology knowledge can influence the outcome of respiratory disorders.

This book is for medical students, residents, healthcare workers, and scientists. Understanding of the concepts contained in this book will give confidence to provide effective medical care.

Chapters cover aspects of hyperbaric physiology, exercise physiology, skeletal muscle dysfunction in chronic respiratory disease patients, impact of environmental media on the respiratory system, and cognitive impairment in chronic respiratory patients.

*Respiratory Physiology* is organized into three sections containing five chapters. Section 1 contains an introductory chapter that discusses the general principles of physiology. Section 2 examines respiratory physiology and exercise. It covers the principles of intermittent sprint work as well as the indicators of sarcopenia in patients with chronic respiratory disease. Section 3 describes the impact of environmental media on the respiratory system.

Sections 2 and 3 provides interesting information about exercise, altitude, and environmental pollution and their impact on health and disease.

As the knowledge of physiology is constantly increasing, this book includes interesting concepts and evidence based on experiences from clinical trials.

I thank all the authors for their contributions in making this interesting manuscript.

I hope readers will enjoy this study of physiology and deepen their knowledge of this field.

> **Ketevan Nemsadze** David Tvildiani Medical University, Georgia

**1**

Section 1

Introduction

Section 1 Introduction

**3**

**Chapter 1**

Physiology

*Ketevan Nemsadze*

physiology [3].

**1. Introduction: What is physiology?**

term of cellular and molecular physiology.

to the human body, and everything in between [4].

understanding of the roles that genes play in physiology [3].

Introductory Chapter: Respiratory

Physiology is the link between the basic sciences and medicine. It integrates the individual functions of all the body's different cells, tissues, and organs into a functional whole, the human body. Understanding the principles of physiology can help us explain the physical and chemical mechanisms that are responsible for the origin, development, and progression of life. Each type of life is from the simplest virus to the largest tree or the complicated human being. The science of *human physiology* attempts to explain the specific characteristics and mechanisms of the human body that make it a living being. The fact that we remain alive is the result of complex control systems. Ultimately, the functions of cells, tissues, and organs must be coordinated and regulated. All of these functions are the essence of the discipline of physiology [1, 2]. Physiology studies dynamic processes of life from the simplest molecules, organelles, cells, tissues to the complex organs and organ systems. The discipline of physiology has been closely interconnected with medicine. Structure and function are related to each other – as in case of anatomy, histology, structural biology and

Medical physiology deals with how the human body functions. Countless molecules, subcellular organelles, cells, tissues, organs and organ systems work coordinately to maintain the homeostasis of a body. It is essential to take a global view of the human body, considering every level of the organizational unit.

Classification of physiology could be according to the organ systems. For many practicing clinicians, physiology may be the function of an individual organ system, such as the cardiovascular, respiratory, or gastrointestinal system. Others focus on the cellular principles that are common to the function of all organs and tissues. This last field has traditionally been called general physiology, but nowadays the

As a discipline of physiology evolves and new information emerges, there is a tendency to integrate physiological concepts from the level of DNA and epigenetics

Physiological genomics is the link between the organ and the gene. The grand organizer—the master that controls the molecules, the cells, and the organs and the way they interact—is the genome with its epigenetic modifications. Physiological genomics (or functional genomics) is a new branch of physiology devoted to the

Some important aspects of physiology remain as fundamentally important today as when the pioneers of physiology discovered them a century or more ago. These early observations were generally phenomenological descriptions that physiologists have since been trying to understand at a mechanistic level. In his lectures on the phenomena of life, Claude Bernard noted in 1878 on the conditions of the constancy of life. Claude Bernard introduced the concept of "milieu intérieur" – internal

## **Chapter 1**


**3. Results and evaluation**

We assumed that the balance of the multi-stage anaerobic digestion process can be influenced by setting the ratio of the seeding material which results in greater degradation of the organic content of the treated waste, as well as in greater methane production.

We evaluated the experimental results based on two aspects:

Co-Digestion of Organic Waste

of the 1:1.5 and 1:2 mixing ratios.

Fig. 4. The degradation rate of organic wastes against time

rate of organic material can be achieved for the whole treatment period.

According to our measurement results, with a 60-days treatment with 1:3 biowaste to seed ratio, 54% organic material degradation can be achieved. In the case of biowaste to seed mixtures of 1:1.5 and 1:2 ratios, only 41-43% of the organic material became decomposed during the same period of time. Thus, when increasing the amount of seeding material with improving the initial conditions of the treatment, a considerable impact in the degradation

0 10 20 30 40 50 60

1:1.5 biowaste:seed 1:2 biowaste:seed 1:3 biowaste:seed 1:1 sludge:seed

**Time (d)**

application.

0

10

20

30

**Rate of degradation (D%)**

40

50

60

and Sewage Sludge by Dry Batch Anaerobic Treatment 105

containing VFG as well, the easily degradable organic material content was higher than in the case of the reactor containing only sewage sludge. The fatty acid accumulated the in reactor containing VFG which led to the acidification of the reactor, in the end. Against the acidification of the biowaste, in the case of the sludge, the values of pH and hydrogen concentration were better than the critical level even in the initial critical phase of the treatment. This calls the attention to that, because of the varying quality of VFG waste, the determination of the seeding material ratio has to be estimated case by case in each practical

We can calculate the degradation of organic material of the waste from the quotient of the methane production totalled in the time and of the chemical oxygen demand of the waste mixture. Figure 4 shows the rate of degradation against time for different seeding rates and substrates (the methane production of the seeding material is deducted). Onto the measurement results we fitted the logistic function describing biological processes (Dt% = Dmax / (1 + e -k(t-t0)). The reaction kinetic parameters are shown in Table 2. The value of *k*  reaction rate constant rose with the increase of the seeding material ratio which resulted in decrease of the value of *t0*. Significant differences cannot be detected in the values of *k* and *t0*

#### **3.1 The results of the organic matter degradation**

The actual methane production of different mixtures of organic wastes and seed, referred to one unit of treated organic material, is shown in Figure 3. The methane production of the seeding material present in the reactor was deducted from the methane production of the mixture of the waste and seeding material. As a result, because of the relatively high degradability of the seeding material, in the case of unbalanced reactors caused by low seeding material ratios, we had even negative methane production in the first 20 days which was indicated as zero value.

Fig. 3. Actual methane production referred to one unit of treated organic material

We reached the highest methane yield with the 1:3 biowaste to seed ratio. With the increase of the seed ratio, the methane production grew, too. The methane yield was very low in the case of 1:0.5 and 1:1 biowaste to seed ratios. Due to the low seed ratio, the waste became acidified (pH 5.5-5.8), so thus the process of methane production was also inhibited. Since our goal was to determine the optimal seeding ratio, we carried out the test in these reactors only for 15 days. The maximal methane production of the seeding material (digested sludge) occurred on day 10, however its extent was one eighth of that of the balanced reactors and the methane production decreased to zero after the 30 days.

Having compared the treatability of the sewage sludge and of the biowaste, with the 1:1 seed ratio applied in practice, we can state that in the case of the sewage sludge, a more balanced reactor performance can be observed. The results suggest that in the case of reactor

The actual methane production of different mixtures of organic wastes and seed, referred to one unit of treated organic material, is shown in Figure 3. The methane production of the seeding material present in the reactor was deducted from the methane production of the mixture of the waste and seeding material. As a result, because of the relatively high degradability of the seeding material, in the case of unbalanced reactors caused by low seeding material ratios, we had even negative methane production in the first 20 days which

Fig. 3. Actual methane production referred to one unit of treated organic material

1:2 biowaste:seed 1:3 biowaste:seed 1:1 sludge:seed

the methane production decreased to zero after the 30 days.

We reached the highest methane yield with the 1:3 biowaste to seed ratio. With the increase of the seed ratio, the methane production grew, too. The methane yield was very low in the case of 1:0.5 and 1:1 biowaste to seed ratios. Due to the low seed ratio, the waste became acidified (pH 5.5-5.8), so thus the process of methane production was also inhibited. Since our goal was to determine the optimal seeding ratio, we carried out the test in these reactors only for 15 days. The maximal methane production of the seeding material (digested sludge) occurred on day 10, however its extent was one eighth of that of the balanced reactors and

0 10 20 30 40 50 60 70 80 90

seed 1:0.5 biowaste:seed 1:1 biowaste:seed 1:1.5 biowaste:seed

**Time (d)**

Having compared the treatability of the sewage sludge and of the biowaste, with the 1:1 seed ratio applied in practice, we can state that in the case of the sewage sludge, a more balanced reactor performance can be observed. The results suggest that in the case of reactor

reactor volume.

was indicated as zero value.

0

5

10

**Methane production (CH**

**4-COD g . kg VS-1 .d-1)**

15

20

25

30

35

40

**3.1 The results of the organic matter degradation**

containing VFG as well, the easily degradable organic material content was higher than in the case of the reactor containing only sewage sludge. The fatty acid accumulated the in reactor containing VFG which led to the acidification of the reactor, in the end. Against the acidification of the biowaste, in the case of the sludge, the values of pH and hydrogen concentration were better than the critical level even in the initial critical phase of the treatment. This calls the attention to that, because of the varying quality of VFG waste, the determination of the seeding material ratio has to be estimated case by case in each practical application.

We can calculate the degradation of organic material of the waste from the quotient of the methane production totalled in the time and of the chemical oxygen demand of the waste mixture. Figure 4 shows the rate of degradation against time for different seeding rates and substrates (the methane production of the seeding material is deducted). Onto the measurement results we fitted the logistic function describing biological processes (Dt% = Dmax / (1 + e -k(t-t0)). The reaction kinetic parameters are shown in Table 2. The value of *k*  reaction rate constant rose with the increase of the seeding material ratio which resulted in decrease of the value of *t0*. Significant differences cannot be detected in the values of *k* and *t0* of the 1:1.5 and 1:2 mixing ratios.

Fig. 4. The degradation rate of organic wastes against time

According to our measurement results, with a 60-days treatment with 1:3 biowaste to seed ratio, 54% organic material degradation can be achieved. In the case of biowaste to seed mixtures of 1:1.5 and 1:2 ratios, only 41-43% of the organic material became decomposed during the same period of time. Thus, when increasing the amount of seeding material with improving the initial conditions of the treatment, a considerable impact in the degradation rate of organic material can be achieved for the whole treatment period.

Co-Digestion of Organic Waste

kg VS-1 unit used by us.

plant treating VFG

it, too) was lower.

sludge digestion alone.

Full scale BIOCEL plant1

Time (d)

more favourable values measured in the case of sludge.

Cumulative methane production

1:3 seed to biowaste2

kg VS-1)

1Value calculated according to Brummeler (1993), 450 m3 reactor, waste TS 36%, VS 65% 2Methane production together with the methane production of the seeding material

(CH4-COD g .

and Sewage Sludge by Dry Batch Anaerobic Treatment 107

accumulation of hydrogen and volatile fatty acids. At sewage sludge digestion, often the hydrolysis appears as the process limiting step (Koster, 1989) which could contribute to the

We compared our measurement results with the operation data of a full scale BIOCEL plant (Brummeler, 1993) (Table 4.). The literature refers the biogas quantities to wet waste mass, to standard condition. For comparability we recalculated the literature data to the CH4-COD g .

Laboratory scale Full scale

5 110.0 22.9 18.4 7.7 1.2 1.6 10 297.7 157.2 98.1 20.9 13.4 8.4 20 660.0 278.7 173.9 46.3 23.7 14.9 40 - 453.5 286.5 - 38.6 24.6 60 - 551.6 325.9 - 47.0 28.0

Table 4. Comparison of the laboratory results with the operation data of a full scale BIOCEL

The results of Table 4 show that the results of the methane production referring to VFG waste reviewed in the literature, at the same moment, significantly exceed the results of the co-digestion of the biowaste with sewage sludge. In our experiment, the difference resulting from the lag phase as well as the lower degradability of the biowaste containing sludge and VFG can be definitely pointed. In our experiment half of the waste mixture was sewage sludge. The sewage sludge applied by us was less degradable than the biowaste, thus, the degradability of one unit of waste mixture (and so the amount of methane production from

The results of Table 4 show that higher gas yield referred to one unit of organic matter can be reached in the case of co-digestion of VFG and sewage sludge than in the case of sewage

We assume that the seed ratio, as a result of two opposing effects, influences the methane production per reactor volume unit. The increase of the seed ratio makes the anaerobic process balanced but at the same time decreases the amount of degradable organic matter per reactor volume unit. That is a question, to what extent the already digested material should be recycled for seeding. Another question is how the co-digestion of the easily degradable VFG and sewage sludge affects the gas production of the reactors. To answer the question, we checked the values of the totalled methane production referred to reactor

**3.2 The results of methane production referred to reactor volume**

1:1 seed to sludge

BIOCEL plant2

Degradation of the organic material (D%)

> 1:3 seed to biowaste2

Laboratory scale

1:1 seed to sludge

Table 2. Kinetic parameters of the degradation process

Considering the rates of actual methane production, we can see that the actual rates measured on day 10 significantly increase with the growth of the amount of seeding material. At the values related to day 30, the effect of seed ratio onto the methane production can be still well detected. The actual rate of the methane production further increased from day 30 also in each cases, which suggests that we can count on a considerable degree of degradation even after day 30. This is confirmed by the *t0* value, as well.

To characterize the process of the anaerobic degradation, we checked the hydrogen content of the biogas, as well as the temporal evolution of the pH of the reactors in the most critical initial phase of the treatment (Table 3). The hydrogen content of the biogas was above the value of the detection limit only in the first 9 days.

Table 3. The hydrogen content of biogas and the pH of wastes in the case of different wastes and seeding ratios

It is seen in the case of biowaste that, by the increase of seeding ratio, the hydrogen content of the biogas decreases and the pH of the waste in reactors increased. During the test period, the hydrogen content of the biogas also decreases and then, following day 9, it is under the value of detection limit. The critical hydrogen concentration, above the 0.01 % as calculated based on the literature (Zehnder et al., 1982), measured in the first 5 days had a negative effect on the methane production in the case of each seeding ratio (Figure 3). By the increase of the seeding, above the ratio of 1:1.5, the hydrogen concentration decreased below the critical value from day 9 and the methane production started to increase. The unfavourable values of hydrogen and pH measured in the case of 1:0.5 and 1:1 ratios led to the acidification of the reactors. The pH of the reactors increased during the test which resulted in the rise of biogas production. During the anaerobic treatment of the sewage sludge, we did not measure significant hydrogen quantity in the biogas even in the case of 1:1 sludge to seed mixing ratio. This can be explained by that there is less easily degradable organic material in the sewage sludge than in the tested biowaste which is responsible for the

1:1.5 biowaste:seed 0.055 44.33 0.936 0.424 0.788 1:2 biowaste:seed 0.054 42.58 0.918 0.453 0.782 1:3 biowaste:seed 0.078 28.29 0.939 0.820 1.256 1:1 sludge:seed 0.060 31.38 0.876 0.526 0.749

Considering the rates of actual methane production, we can see that the actual rates measured on day 10 significantly increase with the growth of the amount of seeding material. At the values related to day 30, the effect of seed ratio onto the methane production can be still well detected. The actual rate of the methane production further increased from day 30 also in each cases, which suggests that we can count on a considerable degree of degradation even after day 30. This is confirmed by the *t0* value, as

To characterize the process of the anaerobic degradation, we checked the hydrogen content of the biogas, as well as the temporal evolution of the pH of the reactors in the most critical initial phase of the treatment (Table 3). The hydrogen content of the biogas was above the

(%) pH H2

1:0.5 biowaste:seed 9.66 5.47 0.38 5.51 1.08 5.55 0.08 5.65 0.06 5.70 1:1 biowaste:seed 4.27 5.70 0.19 5.80 0.13 5.75 0.02 5.78 0.02 5.83 1:1.5 biowaste:seed 3.58 5.90 0.14 5.84 0.10 6.13 0.02 6.06 0.01 6.34 1:2 biowaste:seed 1.40 6.27 0.04 6.32 0.02 6.34 0.01 6.43 0.01 6.59 1:3 biowaste:seed 0.37 6.10 0.05 6.23 <dl 6.45 0.01 6.65 0.01 6.72 1:1 sludge:seed 0.62 6.68 <dl 6.94 <dl 7.09 <dl 7.28 <dl 7.37 Table 3. The hydrogen content of biogas and the pH of wastes in the case of different wastes

It is seen in the case of biowaste that, by the increase of seeding ratio, the hydrogen content of the biogas decreases and the pH of the waste in reactors increased. During the test period, the hydrogen content of the biogas also decreases and then, following day 9, it is under the value of detection limit. The critical hydrogen concentration, above the 0.01 % as calculated based on the literature (Zehnder et al., 1982), measured in the first 5 days had a negative effect on the methane production in the case of each seeding ratio (Figure 3). By the increase of the seeding, above the ratio of 1:1.5, the hydrogen concentration decreased below the critical value from day 9 and the methane production started to increase. The unfavourable values of hydrogen and pH measured in the case of 1:0.5 and 1:1 ratios led to the acidification of the reactors. The pH of the reactors increased during the test which resulted in the rise of biogas production. During the anaerobic treatment of the sewage sludge, we did not measure significant hydrogen quantity in the biogas even in the case of 1:1 sludge to seed mixing ratio. This can be explained by that there is less easily degradable organic material in the sewage sludge than in the tested biowaste which is responsible for the

2nd day 3rd day 5th day 7th day 9th day

(%) pH H2

t0

(d) R2 v10d

(D% .

d-1)

(%) pH H2

(%) pH

v30d (D% .

d-1)

(1 . d-1)

The description of the sample k

Table 2. Kinetic parameters of the degradation process

value of the detection limit only in the first 9 days.

H2

(%) pH H2

Type of the reactor

and seeding ratios

well.

accumulation of hydrogen and volatile fatty acids. At sewage sludge digestion, often the hydrolysis appears as the process limiting step (Koster, 1989) which could contribute to the more favourable values measured in the case of sludge.

We compared our measurement results with the operation data of a full scale BIOCEL plant (Brummeler, 1993) (Table 4.). The literature refers the biogas quantities to wet waste mass, to standard condition. For comparability we recalculated the literature data to the CH4-COD g . kg VS-1 unit used by us.

1Value calculated according to Brummeler (1993), 450 m3 reactor, waste TS 36%, VS 65%

2Methane production together with the methane production of the seeding material

Table 4. Comparison of the laboratory results with the operation data of a full scale BIOCEL plant treating VFG

The results of Table 4 show that the results of the methane production referring to VFG waste reviewed in the literature, at the same moment, significantly exceed the results of the co-digestion of the biowaste with sewage sludge. In our experiment, the difference resulting from the lag phase as well as the lower degradability of the biowaste containing sludge and VFG can be definitely pointed. In our experiment half of the waste mixture was sewage sludge. The sewage sludge applied by us was less degradable than the biowaste, thus, the degradability of one unit of waste mixture (and so the amount of methane production from it, too) was lower.

The results of Table 4 show that higher gas yield referred to one unit of organic matter can be reached in the case of co-digestion of VFG and sewage sludge than in the case of sewage sludge digestion alone.


**8. Conclusion**

It is evident that for ideal chondrogenesis with hyaline cartilage in contained or uncontained lesions, the correct surgical technique with attention to detail, a postoperative adjuvant therapy with a high percentage of viable PBPC in combination with HA, and the importance of a postoperative rehabilitation program are important. Failure to adhere to these three important basic principles will result in inferior repair tissue which will inevitably deteriorate with time.

Articular hyaline cartilage regeneration is possible with arthroscopic subchondral drilling followed by postoperative intraarticular injections of autologous PBPC in combination with HA.

#### **9. References**

It is evident that for ideal chondrogenesis with hyaline cartilage in contained or uncontained lesions, the correct surgical technique with attention to detail, a postoperative adjuvant therapy with a high percentage of viable PBPC in combination with HA, and the importance of a postoperative rehabilitation program are important. Failure to adhere to these three important basic principles will result in inferior repair tissue which will inevitably

Articular hyaline cartilage regeneration is possible with arthroscopic subchondral drilling followed by postoperative intraarticular injections of autologous PBPC in combination

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**8. Conclusion**

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with HA.

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**8**

Masoud Riyami

*Sultanate of Oman*

*Sultan Qaboos University, Oman*

**Traumatic Chondral Lesions of the Knee**

The knee joint is classified as a modified hinge joint, with its structure providing a highly mobile and complex joint (fig.1). It consists of two condylar joints between the medial and lateral condyles of the femur and the corresponding plateaus of the tibia, and anteriorly a synovial plane patellofemoral joint. The articular surface of the knee is covered by Hyaline cartilage that is supported by subchondral bone. This Hyaline cartilage is very soft and yields its interstitial water easily when compressed yet it is very stiff in tension along planes parallel to the articular surface (Buckwalter and Mow, 2003). Intact cartilage provides a smooth, lubricated gliding surface with a coefficient of friction better than most man-made bearing materials (Buckwalter and Mow, 2003). In the knee articular cartilage distributes the loads of articulation, thereby minimizing peak stresses acting on the subchondral bone whilst the tensile strength of the tissue maintains its structural integrity under loading. These biomechanical properties make the tissue remarkably durable and wear resistant, enabling it to last many decades, even under high and repetitive stresses (Buckwalter and Mow, 2003).

**1. Introduction**

**1.1 Anatomy and knee joint function**

Fig. 1. Structure of knee joint (www.arthroscopy.com)

**Diagnosis and Treatment**


**4.3. Toxicological analysis**

**Figure 4.** Proportion of the patients according to the duration of the consumption, previous to MMT.

patients). The other patients have used it differently: smoking or nose sniffing.

ent hallucinogens (ex. L.S.D., ketamine) have occasionally been reported.

*4.1.6. Indicator: way of administration of the heroin*

126 Drug Addiction

relatively short length of time, up to 1 year.

high intensity of drug consumption.

cocaine or designer amphetamines with a hallucinogen component (ex. Ecstasy). Other differ-

The most frequent way of the heroin administration is the i.v. (all the patients have declared the intravenous use of the heroin, in most cases, even at the onset use of the heroin (78% of the

The study shows that most of the patients had previous hospitalizations (70.7%, 58/82), an average number of 8.31 periods and previous periods of MMT (48.78%, 40/82 patients), an average number of 5.45 treatments, previous to the presented study. Also, 40.24% of the patients (33/82) have benefited from psychological counseling, an average of 9.48 meetings. Referring to the abstinence length, only a little percentage (24.4%, 20/82) had abstinence on

These results show that, among the confirmed drugaddicts, the opiates consumers present the most invalidating, with the longest duration and frequency of drug consumption, with a lower compliance to treatment and high resistance as regards the initiation and the maintenance of the abstinence. These present a high frequency of relapses as well as long term and

#### *4.3.1. Indicator: the urine concentration of heroin and metabolites*

The methodology of the quantitative and qualitative toxicological analysis provides with a support, useful in order to analytically diagnose of the drug abuse and to initiate and supervise the substitution treatment.

In the present study, the quantitative toxicological analysis aimed at determining the levels of the heroin and the metabolites in the urine of the heroin consumers, applying the technique of the fluorescent antibody, and using an automatic analyzer. The heroin and metabolite levels in their urine tests have been placed to a large extent, from approximately 700 to over 30,000 ng/mL (**Figure 5**).

During the treatment, not only the initial one, they do tests (which are marked as follows: negative, slightly positive, positive), no matter the patients' declarations. At the assumption or the declaration of relapses, tests grow in number, especially when we speak about the combinations of opiates and heroin or other medicines. The maximum number of tests along a whole year for a single patient has been 27.


*3.7. Serum Hormone Analysis*

Commercially available ELISA kits were used to measure serum thyroxine (T4) and triiodothyronine (T3) (Calbiotech, Spring Valley, CA, USA), norepinephrine and epinephrine (Labor Diagnostika Nord, Nordhorn, Germany), as well as corticosterone (Cayman chemical company, Ann Arbor, MI, USA).


**Silver Nanoparticles: Real Antibacterial Bullets**

G. Thirumurugan and M. D. Dhanaraju *Research Lab, GIET School of Pharmacy, Chaitanya Nagar, Rajahmundry, AP India*

#### **1. Introduction**

406 Antimicrobial Agents

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ammonium moieties, *Journal of Membrane Science*, 320, 259–267

*Journal of Photochemistry and Photobiology A: Chemistry*, 161, 27–34

coating for textiles *Polymer* 46, 10538–10543

124, 89–91

precious metals using the magnetron sputter technique with regard to their anti-

Antibacterial Activity on Cotton Fabrics with Cold Plasma in the Presence of a

Wiener.J, (2010) Investigation of metal absorption and antibacterial activity on

perfluoroalkyl-containing quaternary ammonium salt, *Journal of Fluorine Chemistry,*

activity of electrospun polyurethane fibrous membranes with quaternary

particles with poly(n-butyl acrylate) cores and chitosan shells as an antibacterial

textiles prepared by RF-plasma and vacuum-UV mediated deposition of silver,

One of the first and most natural questions to ask when starting to deal with nanoparticles is: "why are nanoparticles so interesting"? Why even bother to work with these extremely small structures when handling and synthesis is much more complicated than that of their macroscopic counterparts. The answer lies in the nature of and unique properties possessed by nanostructures. Nanoparticles possess a very high surface to volume ratio. This can be utilized in areas where high surface areas are critical for success. Over the past few decades, Metal nanoparticles, whose structures exhibit significantly novel and distinct physical, chemical, and biological properties, and functionality due to their nanoscale size, have elicited much interest. Especially in biological and pharmaceutical sector nanostructure materials are attracting a great deal of attention because of their potential for achieving specific processes and selectivity. Decreasing the dimension of nanoparticles has pronounced effect on the physical properties that significantly differ from the bulk material. Moreover, there are several reasons for the use of silver nanoparticles in nanotechnology as well as in medical and pharmaceutical field. (i) First of all, silver compounds have been used in medicine throughout the history of civilization. (Patra, 2008; Klasen, 2000; Lansdown, 2002) (ii) It is easy to synthesize silver nanoparticles by several simple, economically cheap, safe and reliable methods such as wet chemical, physical and biological; (iii) it can be synthesized from sizes of 2–500 nm by changing the reaction parameters; (iv) it can be easily synthesized with different shapes (spheres, rods, tubes, wires, ribbons, plate, cubic, hexagonal, triangular) using templates and changing reaction conditions; (v) due to the presence of a negative charge on the surface, they are highly reactive, which helps to modify the surface of silver nanoparticles using several biomolecules. Due to the strong interaction between the metal surface and thiol/amine containing molecules (organic molecules, DNA, protein, enzyme etc.) the surface of SNPs can be easily modified; (Bhattacharya, 2007) (vi) SNPs can be easily characterized due to the presence of the characteristic surface plasmon resonance (SPR) bands; (Daniel and Astruc, 2004) due to the presence of a unique optical as well as electronic behavior, these metal particles can be used in biosensors and molecular imaging; (Oghabian, 2010) due to its strong antimicrobial activity, it has found variety of application in different fields (Fig. 1).

Silver Nanoparticles: Real Antibacterial Bullets 409

Most frequently preparation of silver nanoparticles is carried out by chemical reduction method. Borohydrate, citrate, ascorbate, and elemental hydrogen are commonly used reductants for the synthesis of silver nanoparticles. The reduction of metal ions (Me+) like silver (Ag+ or gold (Au+) in aqueous solution generally yields colloidal metal with particle diameters of several nanometers (Wiley, 2005). Initially, the reduction of various complexes with metal (Ag+) ions leads to the formation of metal atoms (Ag0), which is followed by agglomeration into oligomeric clusters (Kapoor, 2002). These clusters eventually lead to the formation of colloidal Metal particles (Kapoor, 2002). For example, while formation of colloidal silver particles, when the colloidal particles are much smaller than the wavelength of visible light, the solutions have a yellow color with an intense band in the 380–400 nm range and other less intense or smaller bands at longer wavelength in the absorption spectrum (Cao, 2002). This band is attributed to collective excitation of the electron gas in the particles, with a periodic change in electron density at the surface (surface Plasmon

The synthesis of silver nanoparticles in this project will be based on a wet chemical method. The starting point of the synthesis is the production of a silver nitrate (AgNO3) solution. When silver nitrate is dissolved it splits into a positive silver ion (Ag+) and a negative nitrate ion (NO3-). In order to turn the silver ions into solid silver, the ions have to be reduced by receiving an electron from a donator. A flowchart illustrating the reduction of the silver ions by addition of an electron can be seen in Equation 1. The flowchart of Equation 2 illustrates the reduction of (Ag+) in a solution of ethanol. After the silver germ has been formed it starts to grow and continue the growth until the equilibrium between the final nanoparticles and

Ag(aq) (s) e Ag + − + →

(aq) 2 5 2 (s) 2 5 2 2Ag C H OH+H O 2Ag C H O 3H <sup>+</sup> − + + →+ +

3 4 2 26 3 AgNO NaBH Ag+ H B H NaNO 1 1 2 2 +→ + +

The preparation of silver nanoparticles in briefly, A 10-mL volume of 1.0 mM silver nitrate was added dropwise (about 1 dropsecond) to 30 mL of 2.0 mM sodium borohydride solution that had been chilled in an ice bath. The reaction mixture was stirred vigorously on a magnetic stir plate. The solution turned light yellow after the addition of 2 mL of silver nitrate and a brighter yellow, when all of the silver nitrate had been added. The entire addition took about three minutes, after which the stirring was stopped and the stir bar removed. The clear yellow colloidal silver is stable at room temperature stored in a transparent vial for as long as several weeks or months. Reaction conditions including stirring time and relative quantities of reagents (both the absolute number of moles of each reactant as well as their relative molarities) must be carefully controlled to obtain stable yellow colloidal silver. A large excess of sodium borohydride is needed both to reduce the ionic silver and to stabilize the silver nanoparticles. The possibility of aggregation during the synthesis, colloidal silver solution turns darker

The chemical reaction is the sodium borohydride reduction of silver nitrate:

(1)

(2)

(3)

absorption), (Gutiérrez, 1993).

the (Ag+) of the solution is reached (Chou, 2005).

Fig. 1. Applications of metal nanoparticles in various fields (G.Thirumurugan, 2011).

The synthesis of monodispersed metal nanoparticles with different size and shape has been challenge in nanotechnology. Although various physical and chemical methods are extensively used to produce monodispersed nanoparticles, the stability and the use of toxic chemicals is the subject of paramount concern. Moreover, the use of toxic chemicals on the surface of nanoparticles and non-polar solvents in the synthesis procedure limits their applications in clinical and pharmaceutical field (Oghabian, 2010) Therefore, development of clean, biocompatible, non-toxic and eco-friendly methods for silver nanoparticles synthesis deserves merit.

In this chapter, we will discuss an overview of silver nanoparticle preparation involving physical, chemical method and biological method, mechanism and advantages and disadvantages of the above methods. We provide various antibacterial mechanisms of silver nanoparticles to reduce antibiotic resistance and incorporation of SNPs on cotton fabrics and conjugation of SNPs on pharmaceutical compounds. Finally, we will discuss site-specific, antibacterial drug delivery of SNPs due to its unique surface modification, photo-thermal properties.


**3. Surgically Assisted Rapid Maxillary Expansion (SARME)**

The areas of resistance to lateral forces in the midface are the pyriform aperture (anterior), the zygomatic buttress (lateral), the pterygoid junction (posterior) and the midpalatal synostosis suture (median). Many surgical interventions and techniques have been developed by the identification of these areas of resistance. Surgery assisted maxillary expansion procedures have conventionally been grouped into 2 categories:

**Advantages of SARME** over orthodontic therapy and segmental Le Fort procedures include decreased risk of periodontal damage, improved esthetics when smiling, improved nasal air flow, and decreased risk of avascularity. SARME is also a relatively simple procedure and is associated with minimal morbidity. Intraoperative complications are uncommon and there is also less chance of avascularity leading to aseptic necrosis than with segmental Le Fort I procedures. [29, 30] Brown [12] was probably the first who described a technique of SARME with midpalatal splitting. [31] In 1961, Haas described the downward and forward movement of the maxilla that occurs during rapid maxillary expansion because of the location of the craniomaxillofacial sutures. He believed that the hemimaxillas separated from each other develop tipping rather than separating in a parallel fashion due to the strength of the zygomatic buttresses. [32]

Most methods consider the zygomaticomaxillary junction the major site of resistance and perform a corticotomy through the zygomatic-maxillary buttress from the pyriform rim to the maxillopterygoid junction. The midpalatal suture is historically considered the major place of resistance. The pterygoid plates are also a considerable site of resistance but because of the increased risk of injuring the pterygoid plexus by the osteotomy, some chose not to, without losing much mobility. By not releasing the pterygoid junction, the pattern of opening of the maxillary halves is more V-shaped with the point of the V located dorsally [33-37].

Isaacson and Ingram [38] and Isaacson et al. [39] mention that historically, the midpalatal suture was thought to be the area of resistance to expansion, but the facial skeleton increases its resistance to expansion as it ages and matures, and that the major site of resistance is not the midpalatal suture but the remaining maxillary articulations. Wertz stated that resistance of the zygomatic arch prevents parallel opening of the midpalatal suture [40]. Many surgeons release the midpalatal suture to improve mobility and to prevent deviation of the nasal septum. Several authors describe two paramedian palatal osteotomies from the posterior nasal spine to a point just posterior to the incisive canal [41-43].

In 1975 and 1976 Bell and Epker demonstrated that the area of increased facial skeletal resistance to expansion was indeed not the midpalatal suture, but the zygomaticotemporal, zygomaticofrontal and zygomaticomaxillary sutures. [44, 45] On the other hand, Shetty concluded that exclusive use of bilateral zygomaticomaxillary buttress osteotomies to facilitate SARME was inadequate. They therefore concluded that complete midpalatal and pterygo‐ maxillary osteotomies were essential for predictable maxillary expansion in adults. [46]

There is a lack of consensus among orthodontists and surgeons about the indications for SARME. Although maxillary expansion may be required for many patients, an accurate diagnosis of maxillary transverse distraction is somewhat ambiguous. This is further compli‐ cated by case reports in the literature about orthodontic maxillary expansion or other forms of expansion in adults. The following have been reported in the literature as indications for SARME, all applying to a skeletally mature patient with a constricted maxillary arch.