**2. Experimental Section**

### *2.1.  HPAM (Mw = 16 to 18 × 106) was purchased from the Hengju Oil Field Chemical Reagents Co, Ltd. (Beijing, China). Deionized (DI) water was obtained from a water purification system.

#### 2.1.1. Synthesis of MAH-β-CD

The activity of various hydroxyl groups in cyclodextrin is different. According to nucleophilic properties, the reaction activity order of the three hydroxyl groups is C6 > C2 > C3. The steric hindrance of the 6-hydroxyl group is small, and the reaction activity is higher under acidic conditions. Therefore, the electrophilic reagent attacks the 6-hydroxyl group, and the reagent with lower reaction activity has the highest selectivity on the 6-primary hydroxyl group. In addition, through references [28,29], it was found that when the molar ratio of 1:1 for the CD and MAH, the yield was higher. A mixture of *β*-CD (5.68 g, 0.005 mol), MAH (4.90 g, 0.005 mol), and anhydrous *N,N*-dimethyl formamide (30 mL) was stirred at 80 ◦C for 10 h. Then, the reaction mixture was cooled to room temperature, and a large amount of chloroform was added to precipitate the compound. The precipitate was filtered and washed three times with a large amount of acetone. Vacuum drying the precipitate at 75 ◦C for 24 h resulted in a 62% yield of a yellow powder (MAH-*β*-CD) (Scheme 1).

**Scheme 1.** Synthesis route of maleic anhydride cyclodextrin (MAH-*β*-CD).

#### 2.1.2. Synthesis of NAP

A mixture of (10.215 g, 0.06 mol) DMAPMA and (10.598 g, 0.06 mol) 1-(chloromethyl) naphthalene was added to 60 mL anhydrous methanol and 60 mL acetonitrile, and sodium carbonate (2.11 g) was added. The system was protected by argon and reacted at 60 ◦C for 48 h at reflux. After the reaction, the solid was filtered, and methanol and acetonitrile were removed at 55 ◦C by rotary evaporator. The concentrated substance was added to diethyl ether; there white powder was produced, named NAP (yield 91%) (Scheme 2).

**Scheme 2.** Synthesis route of NAP.

2.1.3. Synthesis of Copolymer

The appropriate amounts of AM (10 g, 0.14 mol), AA (2.5 g, 0.03 mol), MAH-*β*-CD (0.56 g, 4.54 × 10−4 mol), and NAP (0.15 g, 4.54 × 10−4 mol) were stirred into deionized water under a nitrogen atmosphere for 30 min, and the total monomer concentration was maintained at 30 wt.%. Then, the pH was adjusted to 7.0–8.0 with sodium hydroxide. After complete dissolution, V50 solution was added, the content of which was 0.035 wt.% of the total mass of the monomer. At last, the solution was under a UV light fixture (T5 8-W UVB) at 25 ◦C for 8 h (yield 89–92%). The product was purified three times by precipitation with ethanol dried at 25 ◦C. In this study, three copolymers, HGP, HP-T, and GP-T, were prepared, in which the molar ratio of MAH-*β*-CD to NAP in the three copolymers was 1:1, 1:0, and 0:1, respectively. The synthesis route is shown in Scheme 3.

**Scheme 3.** Synthesis route of copolymer.

#### *2.2. Characterization*

The 1H NMR spectra of NAP, HGP, and MAH-*β*-CD were measured on a Bruker AVANCE III HD 400 spectrometer (Bruker BioSpin, Switzerland). The Fourier Transform Infrared Spectroscopy (FT-IR) of HGP was measured with Nicolet 6700 spectrophotometer.

#### *2.3. Effect of β-CD and MAH-β-CD on NAP CMC*

The influence of *β*-CD and MAH-*β*-CD concentration on the surface tension of NAP was measured by KRUSS DSA30S tensiometer at 25 ◦C. The measurements were repeated three times independently, and the error was represented by the error strip in the figure.

#### *2.4. Effect on the Viscosity of the Functional Monomer*

To investigate the effect of the molar ratio of the MAH-*β*-CD and NAP on the viscosity of polymer solutions, the polymer with different molar ratio of MAH-*β*-CD to NAP was prepared. The measurement was repeated three times independently.

#### *2.5. Conductivity*

In order to explore the impact of the host–guest effect on copolymers' solubility, the DDS-307+ conductivity meter (Chengdu Century Ark Technology Co., Ltd., Chengdu, China) was used to measure the conductivity of HGP, GP-T, and HP-T, and all experiments were conducted at 25 ◦C. The measurement was repeated three times independently.

#### *2.6. Thickening Performance*

The viscosities of the copolymer solutions with various concentrations were measured by HAAKE RS600 rheometer (Thermo Fisher Scientific, 81 Wyman Street, Waltham, MA, USA) at 170 s−1 and 25 ◦C. The measurement was repeated three times independently.

#### *2.7. Microstructure Analysis*

The microstructure of the HGP, HP-T and GP-T solutions was observed by environmental scanning electron microscope (ESEM; Quanta 450, Hillsboro, OR, USA). All samples were frozen at −50 ◦C using liquid nitrogen, and the frozen surfaces of the samples were observed with the ESEM operating at an accelerating voltage of 20 kV.

#### *2.8. Viscoelasticity*

The viscoelasticity of copolymers solutions was measured by an Anton Paar rheometer (MCR302) with CP50-1-SN30644 plate fixture (diameter = 0.099 mm) at 25 ◦C. The measurement was repeated three times independently.

#### *2.9. Shear Tolerance*

The shear tolerances of the copolymer solutions (0.6 wt.%) were measured by a continuous shear from 7.31 s−1 to 1000 s−1 at 25 ◦C for 30 min by the HAAKE MAR III RS 600 rheometer. The shear recoveries of shear rates at 170 s−1 and 510 s−1 were measured under the same conditions. The measurement was repeated three times independently. The thermal shear of HGP, HP-T, and GP-T solutions was investigated. The temperature was raised from 30 ◦C to 120 ◦C over a period of 120 min at a constant shear rate of 170 s−1.

#### *2.10. Salt Tolerance*

To investigate the salt tolerance of the copolymer solutions HGP, HP-T, GP-T, and HPAM, the viscosity of polymers (0.6 wt.%) in different concentrations of sodium chloride was measured. Similarly, the salt tolerance of the copolymers was investigated in calcium chloride solution and magnesium chloride solution, respectively. The viscosity was measured by the HAAKE rheometer at 170 s−1 and 25 ◦C.

#### **3. Results and Discussion**

#### *3.1. Characterization*

The HGP structure was confirmed by 1H NMR, as shown in Figure 2c. The proton signals at 4.70 ppm were assigned to the solvent proton (D2O). Proton signals of 3.0 ppm were assigned to –N+–CH3, and 5.56 to 6.24 ppm were associated with the proton peak of naphthalene. A 0.88 ppm proton signal could be assigned to the -CH3 proton in the polymer backbone. The proton signals of 1.603 ppm and 2.143 ppm were attributed to the -CH2-CHin the polymer backbone. The two protons of the main chain of the MAH-*β*-CD were around 2.45 ppm (-CH-) and at 1.70 ppm (-CH2-). The proton signal at 4.998 ppm was associated with the *β*-CD glucose unit (O-CH-O). The mass signal was considered to be the glucose proton units C-CH-OH and C-CH2-OH at 3.681 ppm. The 3.272 ppm proton signal was derived from the C-CH-O of the glucose proton unit, which corresponds to Figure 2a,b; the experimental results verified the identity of the synthesized polymer to the target.

**Figure 2.** *Cont*.

**Figure 2.** 1H NMR spectrum: (**a**) MAH-*β*-CD, DMSO; (**b**) NAP, D2O; (**c**) HGP, D2O.

HGP was characterized and confirmed by the FT-IR spectrum shown in Figure 3. The absorption bands at 3455 cm−1 and 1673 cm−1 were due to the stretching vibration of N-H and C=O in the acrylamide groups (–CONH2). The band at 3098 cm−1 was attributed to the C-H stretching vibration of arene hydrocarbons. The band at 2927 cm−1 was due to the stretching vibration peak of -CH2-. The peak at 1446 cm−1 was assigned to the stretching vibration of the arene C-C skeleton. The 1415.4 cm−1 peak was attributed to the in-plane bending vibration peak of amide C-N and N-H. The bands observed at 1336 cm−1 was due to the vibration of -CH2-. The band at 844 cm−1 was the in-plane and out-plane bending vibration of arene C-H. Furthermore, the stretching vibration of C-O-C referred to the band at 938.00 cm−1 which corresponded to the skeleton vibrations of *β*-CD. The FT-IR spectra confirmed that NAP and MAH-*β*-CD had been successfully introduced into the polymer.

**Figure 3.** The FTIR spectrum of HGP.

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#### *3.2. Effect of β-CD and MAH-β-CD on NAP CMC*

The critical micelle concentration (CMC) of NAP was measured at 25 ◦C. As shown in Figure 4a, with the increase in concentration, the surface tension of the NAP solution decreases continuously. When the concentration is 3.54 × 10−4 mol/L, the surface tension drops to the minimum and rarely changes with the increase in concentration, indicating that the CMC of NAP is about 3.54 × 10−4 mol/L. Figure 4b shows the relationship between the surface tension of NAP (3.54 × 10−4 mol/L) and the concentration of cyclodextrin (*β*-CD or MAH-*β*-CD) at 25 ◦C. Clearly, with the increase in CD/NAP, the system surface tension increases continuously. When CD:NAP ≈ 1, the surface tension reaches the maximum and tends to be stable. It can be seen that MAH-*β*-CD, like the *β*-CD, has a similar binding effect on hydrophobic guest NAP, and an inclusion ratio of CD:NAP ≈ 1.

**Figure 4.** (**a**) Surface tension of NAP at 25 ◦C; (**b**) relationship between CD:NAP and NAP surface tension at 25 ◦C.

#### *3.3. Effect on the Viscosity of Host–Guest Monomer Ratio*

It is well known that monomer content has a marked effect on polymer viscosity [30]. As shown in Figure 5, with the increase in the molar ratio of the host–guest monomer, the viscosity of the solution increased first and then decreased. When the molar ratio of MAH-*β*-CD to NAP was 1:1, the solution viscosity reached the maximum 194 mPa·s, corresponding to the effect of CD on NAP CMC. The highest effective host–guest structure in the solution occurred when the molar ratio was 1:1, resulting in a significant increase in viscosity.

**Figure 5.** The 0.6 wt.% HGP viscosity at various monomer molar ratios with a shear rate of 170 s−1 at 25 ◦C.

#### *3.4. Conductivity*

It is important for application in oilfields that polymers dissolve in water immediately. When the polymer is completely dissolved, the conductivity hardly changes over time. As shown in Figure 6, the conductivity of HGP, GP-T, and HP-T gradually stabilized over time. The conductivity of HGP and HP-T tends to stabilize quickly, at 4.2 min and 5.1 min, respectively. However, the GP-T was relatively slow and did not become stable until 8.0 min. *β*-CD can wrap the hydrophobic groups to form an inclusion compound due to its unique structures, including hydrophobic inner cavity and hydrophilic outer cavity. Thus, the hydrophobic association between the hydrophobic groups in the polymer was shielded, accelerating the diffusion rate of the polymer molecules to water, and reducing the dissolution time of the polymer. From this perspective, polymers using the host–guest strategy have more promising application prospects than hydrophobic associating polymers.

**Figure 6.** Conductivity changes in the dissolution process of copolymers at 25 ◦C.

#### *3.5. Thickening Performance*

The viscosity of the polymer solution increases as the concentration increases. As shown in Figure 7, the four polymers exhibited good proportional linear thickening properties. When the concentration increased from 1000 mg/L to 3500 mg/L, the growth rate in viscosity of the HGP was the highest (168%), and HP-T had the lowest liquid viscosity growth rate (92.5%). This could be interpreted as follows: at low concentrations, the system thickening effect was not obvious, but when the concentration was more than 1000 mg/L, the inclusion effect became significant, and the host–guest recognition between the *β*-CD and NAP on the polymer formed a cross-linked 3D network structure. In addition, the hydrophobic association also contributes to viscosity, as shown in Figure 8. As a result, the viscosity of HGP rose sharply.

#### *3.6. Microstructure Analysis*

ESEM was used to investigate the reasons for the increase in polymer viscosity. In Figure 9, microcosmic network structures in HGP are much denser than those of GP-T and HP-T. As shown in Figure 9a, there is a noticeable multilayer 3D structure containing pores with different sizes in the HGP solution as a result of the host–guest effect, which could not only support the polymer chain but also encapsulate a lot of water. In other words, the host–guest effect can increase the apparent viscosity and deformation resistance.

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**Figure 7.** Apparent viscosity as a function of copolymer concentrations for HGP, GP-T, HP-T, and HPAM at shear rate of 170 s−1 at 25 ◦C.

**Figure 8.** The thickening mechanism of HGP.

**Figure 9.** SEM morphologies of 0.6 wt.% GP-T, HP-T, and HGP in DI water (1000×). (**a**) HGP, (**b**) HP-T, (**c**). GP-T.

#### *3.7. Viscoelasticity*

The change in storage modulus (*G'*), loss modulus (*G"*), and intersection (*Gc*) depended on the frequency [4]. Figure 10 shows that for HGP, HP-T, and GP-T, at a low frequency where the *G'* was less than *G"*, the viscous modulus played a dominant role. The storage and loss moduli increased with the increase in frequency. As the scanning frequency further increased above the characteristic frequency where *G'* and *G"* crossed each other (*Gc*), the *G'* was more significant than the *G"*, indicating that the *G'* played a

dominant role. The relaxation time *tc* corresponding to the intersection *Gc* can be used to describe the solution viscoelasticity. A longer *tc* verifies that the solution contributes more to elastic efficiency. Table 1 shows the relaxation times of different solutions according to the calculation results; the *tc* of HGP, GP-T, and HP-T are about 2.68, 0.451, and 1.3103 s, respectively, suggesting that the host–guest structure can endow the polymer solution with superior viscoelasticity.

**Figure 10.** *G'* and *G"* varying as a function of angular frequency for three polymers. (**a**) HGP, (**b**) GP-T, (**c**) HP-T.

#### *3.8. Shear Tolerance*

As shown in Figure 11, the viscosity decreased as the shear rate increased, indicating that those polymer solutions are typical pseudoplastic fluids. With the increase in shear rate, the forces between groups and molecular chains were destroyed, including hydrogen bonds, van der Waals forces, and hydrophobic associations. The flow resistance of the system dropped dramatically, resulting in a decrease in apparent viscosity. In addition, the viscosities of HGP, GP-T, and HP-T were 87.8 mPa·s, 47.5 mPa·s, and 53.2 mPa·s, respectively, at a shear rate of 1000 s−1. A similar situation can also be observed in Figure 12. When the shear rate alternated between 170 s−1 and 510 s−1, the HGP solution showed the best shear recovery performance, indicating that the HGP solution had good shear resistance properties caused by the interaction between the *β*-CD and the hydrophobic group. When the shear occurred, the host–guest interaction was destroyed, producing many free host and guest groups at the cross-section. While shear rate decreased, the host–guest effect reformed, leading to the recovery in the viscosity of polymer solutions.

**Figure 11.** Apparent viscosity relative to shear rate of the HGP, GP-T, and HP-T at 0.6 wt.%.

**Figure 12.** The HGP, GP-T, and HP-T apparent viscosity relative to alternating shear rate.

The polymer will experience shear and temperature increase in the reservoir. Thus, it is necessary to evaluate the behaviors of polymers in formation water. In the experiment, formation water of the SZ1-1 oilfield in the Bohai Sea was used to prepare 0.6 wt.% polymer solution at 25 ◦C; the formation water composition is shown in Table 2.

**Table 2.** Formation water ion composition.

Figure 13 shows that the viscosity of the polymer solution decreased as the temperature increased. From 30 ◦C to 120 ◦C, the HGP viscosity maintains at approximately 90 mPa·s, significantly greater than HP-T (51 mPa·s) and GP-T (30 mPa·s), indicating that the HGP has greater temperature resistance than HP-T and GP-T. *β*-CD encapsulating the hydrophobic chain was an exothermic reaction [24,31], leading to the dissociation of the *β*-CD inclusion complex with increasing temperature due to the Brownian motion. In addition, the weakening of the hydrophobic association resulted in a considerable reduction in viscosity. However, the conformation of the polymer at high temperature determines its hydrodynamic volume, which determines the viscosity. The conformation is mainly affected by the rigidity of the polymer and the forces between groups and molecular chains. Although rigidity of the polymer worsens the flexibility of the molecular chain, it can make the molecular chain more extended [32]. Therefore, increasing the rigidity of the polymer can effectively increase the temperature resistance, and the introduction of the hydrophobic group can also change the conformation of the polymer at high temperatures [33]. Thus, the temperature resistance of the polymer solutions at high temperatures was HGP > GP-T > HP-T.

#### *3.9. Salt Tolerance*

Inorganic salt has a negative influence on the polymer solution viscosity, especially the divalent ones, such as Ca2+ and Mg2+ [34]. As shown in Figure 14a, the viscosity change of the HGP solution was more pronounced than those of the HP-T and GP-T solutions. When the NaCl concentration was less than 20,000 mg/L, the viscosity of the HGP solution decreased as the NaCl concentration increased. This can be interpreted as sodium ions shielding the carboxylate ions on the polymer, which reduces electrostatic repulsion between the anions, causing the polymer backbone to curl, resulting in the reduction in viscosity at the initial stage.

**Figure 13.** Rheological properties of copolymers HGP, HP-T, and GP-T at 120 ◦C.

**Figure 14.** Effects of inorganic salt concentrations on the viscosities of HGP, GP-T, HP-T, and HPAM, 0.6 wt.%. (**a**) NaCl, (**b**) MgCl2, (**c**) CaCl2.

When the content of NaCl increases from 2 × 104 mg/L to 12 × 104 mg/L, the polarity of the solution increases, which strengthens the hydrophobic association and the host– guest effect. Macroscopically, the viscosity of HGP increased from 117 mPa·s to 290 mPa·s. Further, when the NaCl concentration reached 30 × 104 mg/L, the viscosity lowered from 290 mPa·s to 89 mPa·s. This can be clarified as when the salt concentration further increases, the electrostatic shielding effect was greater than the host–guest interaction and hydrophobic association, resulting in the polymer backbone crimp and a sharp decrease in viscosity. For HPAM, the electrostatic shielding effect of salt on carboxylate ions was significant, and the polymer backbone crimped seriously, so the viscosity of HPAM is almost the same as that of water [35].

Similarly, the effect of CaCl2 and MgCl2 on the viscosity of the polymer solution was also investigated, as shown in Figure 14b,c. With the increase in concentrations of CaCl2 and MgCl2, the viscosity of the HGP was higher than that of HP-T and GP-T, indicating that the host–guest effect between NAP and *β*-CD can improve the salt tolerance of the polymer. When the brine concentration reached 2 × 104 mg/L, the viscosity of HGP in CaCl2 and MgCl2 decreased from the initial viscosity to 71.6 and 82.5, respectively. However, when the concentration of inorganic salts reached 7000 mg/L, the viscosity of the HPAM solution was reduced almost to zero.

#### **4. Conclusions**

In this study, a water-soluble polymer, HGP, was synthesized that combined the host– guest effect of *β*-cyclodextrin and NAP. From the experiments, six conclusions were drawn:

Therefore, HGP has good application prospects for drilling, hydraulic fracturing, and enhanced oil recovery.

**Author Contributions:** Formal analysis, T.X. and Y.Z.; Funding acquisition, X.Y. and C.L.; Investigation, A.D., Q.Z. and J.M. (Jinhua Mao); Software, H.Z.; Writing—original draft, T.X.; Writing—review and editing, T.X. and J.M. (Jincheng Mao). All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by National High Technology Research & Development Program (Grant Nos. 2016ZX05053, 2016ZX05014-005-007), China Postdoctoral Science Foundation (Grant Nos. 2019M650250), and the National Natural Science Foundation of China.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author.

**Acknowledgments:** The research is partly supported by the National High Technology Research & Development Program (2016ZX05053, 2016ZX05014-005-007), China Postdoctoral Science Foundation (2019M650250), and the National Natural Science Foundation of China (41902303). We thank Jincheng Mao, Xiaojiang Yang, and Chong Lin for providing the helpful of Funding.

**Conflicts of Interest:** The authors declare no conflict of interest.


**The Role of Objectively Measured, Altered Physical Activity Patterns for Body Mass Index Change during Inpatient Treatment in Female Patients with Anorexia Nervosa**

**Celine S. Lehmann 1,2, Tobias Hofmann 1, Ulf Elbelt 1,3, Matthias Rose 1, Christoph U. Correll 2,4,5, Andreas Stengel 1,6,\*,† and Verena Haas 2,\*,†**

Received: 23 August 2018; Accepted: 12 September 2018; Published: 18 September 2018

**Abstract:** Increased physical activity (PA) affects outcomes in patients with anorexia nervosa (AN). To objectively assess PA patterns of hospitalized AN patients in comparison with healthy, outpatient controls (HC), and to analyze the effect of PA on Body Mass Index (BMI) change in patients with AN, we measured PA in 50 female patients with AN (median age = 25 years, range = 18–52 years; mean BMI = 14.4 ± 2.0 kg/m2) at the initiation of inpatient treatment and in 30 female healthy controls (median age = 26 years, range = 19–53 years; mean BMI = 21.3 ± 1.7 kg/m2) using the SenseWear™ armband. Duration of inpatient stay and weight at discharge were abstracted from medical records. Compared with controls, AN patients spent more time in very light-intensity physical activity (VLPA) (median VLPA = 647 vs. 566 min/day, *p* = 0.004) and light-intensity physical activity (LPA) (median LPA = 126 vs. 84 min/day, *p* < 0.001) and less time in moderate-intensity physical activity (MPA) (median MPA = 82 vs. 114 min/day, *p* = 0.022) and vigorous physical activity (VPA) (median VPA = 0 vs. 16 min/day, *p* < 0.001). PA and BMI increase were not associated in a linear model, and BMI increase was mostly explained by lower admission BMI and longer inpatient stay. In a non-linear model, an influence of PA on BMI increase seemed probable (jack knife validation, *r*2 = 0.203; *p* < 0.001). No direct association was observed between physical inactivity and BMI increase in AN. An altered PA pattern exists in AN patients compared to controls, yet the origin and consequences thereof deserve further investigation.

**Keywords:** accelerometry; eating disorders; motor restlessness; physical inactivity

#### **1. Introduction**

The role of increased physical activity (PA) for the onset and maintenance of anorexia nervosa (AN) is increasingly recognized. Being associated with a longer duration of inpatient treatment [1] and higher rates of a chronic outcome [2] as well as drop-out from treatment [3], increased PA can be regarded as a significant factor in the persistence of the disease [4]. However, high level PA is addressed insufficiently by current research [5]. As a consequence, a deeper understanding of the mechanisms underlying altered PA in AN as well as for the development of suitable therapeutic strategies to manage PA during weight restoration efforts are urgently warranted to improve outcomes for patients with AN.

Elevated levels of physical activity have been observed in 30–80% of patients suffering from AN [6,7], with this high range probably resulting from varying methods of PA measurement [8]. When assessed with subjective measurement tools including exercise questionnaires, patients reported higher total PA in comparison with a control group, yet simultaneous objective PA assessment using actigraphy yielded similar PA levels [9], suggesting that self-report overestimated PA in patients with AN and that objective assessments are needed to obtain accurate results. In addition, PA behavior is complex and has multiple dimensions; therefore, objective quantification of PA targets different components. Previous studies on objectively assessed PA in AN have yielded mixed results, with some reporting no differences in time spent in moderate to vigorous and daytime PA [10], or fidgeting [8], while others reported increased moderate to vigorous PA duration [3] and seated non-exercise PA [11] between AN inpatients and controls.

In a previous study [12], we focused on a potential link between high PA in AN and hypoleptinemia using a multisensor body monitor (Sensewear™ armband) for objective PA detection in hospitalized adults with AN. Results indicated that the use and interpretation of accelerometry, employed to objectively assess PA in AN patients, needs to be developed further and should also include parameters of physical inactivity. Building on the previous findings based on simple step count, the present study focused on a more detailed analysis of an expanded set of objectively measured PA patterns and intensities in adult females with AN, including inactivity parameters and adding a comparison to normal weight controls. We aimed to investigate the relationship between different PA patterns and BMI increase during inpatient treatment. We hypothesized that during inpatient treatment (I), hospitalized adult AN patients show increased low intensity PA in comparison with healthy controls, (II) increased low-level PA and BMI increase are inversely related, and (III) physical inactivity and BMI increase are directly related.

#### **2. Subjects and Methods**

#### *2.1. Study Population*

We enrolled 50 female adults with AN who were admitted to the Department of Psychosomatic Medicine at Charité—Universitätsmedizin Berlin for inpatient treatment of AN between 2011 and 2016. Patient inclusion criteria were: A diagnosis of AN according to ICD-10 (International Statistical Classification of Diseases and Related Health Problems, 10th Revision), restrictive, purging or atypical type, as well as a BMI < 17.5 kg/m2. Exclusion criteria were: age <18 years, current pregnancy or a diagnosed psychotic episode. Information about the duration of the illness, comorbidities as well as medication at the beginning and end of the treatment program were retrieved from anamnestic data and medical reports. Between 2015 and 2016, we also recruited 30 sex-matched and similar aged normal weight healthy controls (HC), consisting mostly of clinical staff and relatives thereof. A BMI between 18.5 and 25 kg/m2 served as inclusion criteria. Exclusion criteria were: Any known major medical or psychiatric disease and any condition with significant influence on PA. All participants gave written informed consent, and the study was approved by the institutional ethics committee of the Charité—Universitätsmedizin Berlin.

#### *2.2. Anthropometry*

Weight of all patients was measured to the nearest 0.1 kg via a digital scale (Seca 771, Vogel & Halke, Hamburg, Germany) and height to the nearest 0.5 cm via a stadiometer (Seca 220 Stadiometer, Vogel & Halke, Hamburg, Germany) [13]. Measurements took place in the morning between 7 and 8 a.m. after overnight fasting and in underwear. Weight of the controls was measured after a 2-h fast using a chair scale (MCB300K100M, KERN & Sohn GmbH, Balingen, Germany) and height was measured using a stadiometer (Vogel & Halke). BMI was calculated as kg/m2.

#### *2.3. Bioelectrical Impedance Analysis*

Whole-body bioimpedance was measured by Nutriguard-M (Data Input, Darmstadt, Germany; electrodes: Bianostic-AT, Data Input) as part of the patients' clinical measurements. For bioimpedance analysis (BIA) of the normal-weight controls Biacorpus RX 4004 (MEDICAL HealthCare GmbH, Karlsruhe, Germany; Electrodes: BIA Classictabs, Medical HealthCare GmbH, Karlsruhe, Germany) was used. Patients and controls were weighed after fasting for at least 2 h, voiding and an equilibration period in a supine position. The equilibration period of both AN patients and controls lasted at least 10 min. BIA was carried out in accordance to the manufacturer's instructions, and body composition was calculated with Body Comp software (Version 9.0, Professional Scientific, Medical Health Care GmbH, Karlsruhe, Germany).

#### *2.4. PA Assessment*

PA was measured in AN patients after inpatient admission and inclusion into the study. Using a portable armband device (SenseWear™ PRO3 armband; BodyMedia, Inc., Pittsburgh, PA, USA), PA was continuously detected over a 3-day period (Friday to Sunday). During the time of PA detection, the study population was not restricted regarding their daily physical activity [13]. A day was included into data analysis if the armband had been worn for at least 20.5 h [13]. Measurements of controls took place while they stayed in their usual environment and by using the SenseWear™ PRO3 or the SenseWear™ MF armband. According to a statement of the manufacturer from 15 March 2011, the Sensewear Pro 3 and MF models were shown to be functionally equivalent in terms of sensor technology and data analysis (manufacturers statement on equivalency available on request).

The Sensewear armband is a multi-sensor device worn on the upper dominant arm which enables a continuous physiological PA detection [14] by measuring parameters such as heat flow, galvanic skin response (GSR), body temperature and near-body temperature [15]. An integrated two-axial accelerometer captures the movement of the upper arm as well as the position of the body [14]. The information captured by the five sensors and participant characteristics (age, sex, weight, height, smoker or non-smoker and handedness) [16] are integrated and analyzed by a proprietary software (SenseWear™ Software, Version 8.0, BodyMedia, Inc., Pittsburgh, PA, USA). This program is based upon algorithms of the manufacturer and able to analyze the collected raw data at different metabolic equivalent (MET) values. The latter represents a standardized indicator which is independent of time, body weight and sex [15]. One MET is equivalent to 1 kcal/h/kg body weight and serves as useful parameter to describe the energy expenditure [17] and intensity [15] of a specific activity. The MET value ranges from 1 MET while at rest [17] and 1.1 METs when driving in a car to 2–4 METs when doing housework [15], and can reach maximum values of 20 METs when doing excessive sports [15]. According to previous studies, we used six different MET categories to classify different activity intensities of PA within our AN and control group:


**7.2. Fairness considerations**

The multihop and clustering methods are based on selecting certain nodes that transmit the data of other SNs in addition to their own data. This could lead to an increase in energy consumption for some of these nodes compared to the non-cooperative scenario, although the overall energy consumption in the network is minimized. In [29], it was shown that, within a single cluster, fading variations lead to selecting a different cluster head for each fading realization, and this was shown to lead to fairness in energy consumption in the cluster on the long term. Thus, in the case of WSNs deployed for long term measurement and monitoring of certain parameters, different training phases (as explained in Section 7.1), will occur. Consequently, the techniques presented in this Chapter can be considered to be fair. In fact, different SNs will take turn to relay the SR data when the fading varies, which averages out the energy consumption levels among SNs.


Types of Engineered Wood and Their Uses

*Masuod Bayat*

## **Abstract**

Engineering wood, also known as composite wood or manufactured wood, is a versatile and sustainable material that has gained significant popularity in various engineering applications. Engineering wood is created by combining natural wood fibers or particles with adhesives and other additives to enhance its strength, durability, and dimensional stability. The resulting material exhibits improved properties compared to traditional solid wood, such as a higher strength-to-weight ratio, resistance to moisture and pests, and reduced warping or shrinking. One of the primary applications of engineering wood is in the construction industry. Another significant application of engineering wood is in the furniture industry. It can be molded into various shapes and sizes, allowing for intricate designs while maintaining structural integrity. Engineered wood products like plywood and medium-density fiberboard (MDF) are commonly used for manufacturing cabinets, tables, chairs, and other furniture pieces. Engineering wood also finds application in the automotive sector. The versatility of engineering wood extends beyond the construction, furniture, and automotive industries. In conclusion, engineering wood offers a wide range of applications across various industries due to its enhanced properties compared to solid wood. Its use in construction provides durable structural elements while reducing environmental impact.

**Keywords:** engineering wood, environment, engineering wood product, engineering wood types, engineering wood applications

### **1. Introduction**

Wood has been used by humans in various fields since ancient times, but in recent years, environmental problems have made governments and global health officials think of a solution to minimize ecological pollutants Above all, he thought about preserving the forests. Wood has living and dead cells, which has caused its properties to be strongly affected by factors such as time, humidity, heat, etc. Wood has relatively good properties against pressure, bending, and stretching. Also, wood has relatively good heat and sound insulation properties. Unlike steel and many other metals, wood is reversible. In addition, wood has a natural and impressive beauty that has caused it to be used in various industries, including furniture production, interior and exterior decoration of buildings, etc. [1].

Wood is one of the most important construction and industrial materials obtained from trees. Wood has unique physical, chemical, and mechanical properties that make it suitable for use in various industries, including construction, furniture production, paper production, etc. Wood is one of the most important natural resources used in various industries such as construction, furniture, and vehicles.

The decrease in the level of forests and natural resources is reaching more acute and worrying stages day by day; So that nowadays the efforts of all countries are toward the optimal use of wood raw material. Wood is one of the oldest building materials and has many advantages as a building material. Therefore, by using natural and recyclable wood products, environmental degradation can be controlled to some extent. Also, reducing energy consumption and costs is very important [2].

However, improper use of forests and neglecting issues related to environmental protection can lead to air pollution, biodiversity loss, environmental degradation, and climate change. To preserve the environment and sustainable use of wood, new approaches have been developed, such as planting sustainable forests, recycling wood, using engineered wood, and using alternative materials such as polymers and metals. Also, new technologies such as wooden buildings with minimal energy consumption and the production of recycled paper help to preserve the environment. The decrease in the level of forests and natural resources is reaching more acute and worrying stages day by day; So today the efforts of all countries have led to the optimal use of wood raw material [3]. However, due to improper harvesting of forests, environmental degradation, biodiversity loss, and climate change, wood use may harm the environment [4]. To preserve the environment and sustainable use of wood resources, new approaches such as planting sustainable forests, wood recycling, using engineered wood, and using substitute materials for natural wood such as polymers and metals have been developed [5].

The use of wood waste as raw materials in the production of products is very important, due to the reduction of harvesting from forests and the preservation of the environment. Also, by recycling wood waste, you can save natural resources and reduce production costs [6].

Engineered wood is wood that has been improved using chemical, physical, and mechanical processes. This type of wood can be used as a substitute for natural wood in many applications such as the construction industry, furniture industry, art industry, etc., by increasing its strength, hardness, dimensional stability, and other mechanical properties [7]. **Figure 1** shows the use of wood from ancient times to today.

Engineering wood, also known as composite wood or manufactured wood, has gained significant recognition and usage in various industries due to its versatility and

**Figure 1.** *The use of wood from the past to the present [8].*

#### *Types of Engineered Wood and Their Uses DOI: http://dx.doi.org/10.5772/intechopen.112545*

enhanced properties compared to traditional solid wood. This engineered material is created by bonding together multiple layers of wood veneers or fibers with adhesives, resulting in a strong and stable composite product [9]. The development of engineering wood has revolutionized the construction, furniture, and interior design industries, offering an array of benefits and applications.

This introduction aims to provide an overview of engineering wood and explore its wide-ranging applications in different sectors. One of the primary advantages of engineering wood is its improved strength and stability compared to solid wood [10]. By combining different layers of wood, this composite material achieves enhanced structural integrity, making it suitable for demanding applications in construction. Additionally, engineering wood exhibits superior dimensional stability, reducing the risk of warping, twisting, or splitting that can occur with solid wood. Another significant advantage of engineering wood is its environmental sustainability. Many engineered wood products are manufactured using wood fibers sourced from sustainably managed forests, ensuring responsible and eco-friendly production [11].

Additionally, the utilization of engineered wood reduces the demand for solid wood, contributing to the conservation of natural resources. The versatility of engineering wood is evident in its wide range of applications. In the construction industry, it is commonly used for structural components such as beams, columns, and floor systems, where its strength, stability, and durability are key factors. Engineering wood can also be found in furniture manufacturing, enabling the creation of esthetically pleasing and long-lasting pieces. Its consistent quality and resistance to warping make it an ideal choice for cabinetry, tables, chairs, and other furniture items. Furthermore, engineering wood finds its place in interior design, where it is utilized for wall paneling, decorative elements, and various architectural features [12].

By understanding the characteristics and applications of engineering wood, professionals and enthusiasts can make informed decisions when selecting materials for their projects. This knowledge allows for the utilization of engineering wood's unique properties to achieve desired outcomes in terms of strength, durability, sustainability, and esthetics. In the following sections of this article, we will delve deeper into the different types of engineering wood, their specific applications, and the advantages they offer. By exploring these aspects, readers will gain a comprehensive understanding of engineering wood and its potential to transform various industries.


Introductory Chapter: Renal Diseases

Edward T. Zawada

## 1. Introduction

Renal diseases are notoriously silent. Renal diseases are notoriously expensive once they have led to end-stage renal failure requiring dialysis or transplantation. Most acute and chronic renal diseases present with rising serum creatinine and blood urea nitrogen, electrolyte abnormalities, frequent proteinuria, occasional red blood cells in the urine, occasional white blood cells in the urine, or renal cells in the urine often mistaken for white blood cells. It is not easy to make a specific diagnosis from these similar presentations.

I will now present the rationale for renal biopsy to establish renal diagnoses [1]. The classification which follows is the opinion of the author and editor based on over 45 years of experience and exposure to the pioneers in use of renal biopsy for diagnosis [2–4]. My goal is to simplify this argument for performing this invasive procedure to clarify the confusing array of renal diseases with indistinct or asymptomatic presentations.

### 2. Renal disease diagnosis

Acute renal diseases are described as prerenal, renal, and postrenal, but most patients totally recover normal or near-normal renal function. It is the chronic, often symptomless chronic diseases which lead surreptitiously to end-stage renal disease. Chronic diseases include vascular, glomerular, tubular, and interstitial diseases. The main structures of the kidney are arteries and veins, glomeruli, tubules, and interstitium. Renal biopsy is often required to determine the site of injury. As described below, even when the site of injury is known, such as in glomerular diseases, the renal biopsy is needed to distinguish between the many similar diseases in order to develop possible remission-inducing therapy strategies.

I have been teaching about renal diseases since for 40 years since 1979. I have been struck by three main perspectives. First, diseases can occur in very small areas of the structures of the kidney while the rest of the kidney tissues work well and try to compensate. Second, glomerular diseases are confusing to understand because one needs a framework to separate the multiple very similar diseases into separate clinically relevant entities allowing individual management. Finally, the tubular diseases are the most silent of renal diseases, needing more effort to teach, understand, identify, and manage. Renal biopsy results will be briefly described as the tool to make a definitive diagnosis necessary for proper patient management.

## 3. Renal biopsy

Normal renal histology must be known to the clinician before biopsy can be interpreted. The glomeruli will be numerous and have wide-open, thin-walled capillary loops; no inflammatory cells seen; and no increase in numbers of mesangial cells. There can be less than 30% of any glomerulus or all glomeruli which contain amorphous loss of architecture called sclerosis. The blood vessels need to be open without cellular or muscular thickening. Finally, the cross section of renal tubules normally abuts directly against each other without evidence of inflammatory cells or scarring by fibrosis between them.

immunodeficiency virus, new drugs including new biologicals, and new immuno-

Finally, the group at New York Presbyterian/Columbia University Medical Center should be commended as they have continued to provide the most comprehensive annual tutorial and update of the interpretation of renal biopsies based on the very large number of biopsies referred to them [7]. Many of the chapters in this book concentrate on the importance of renal biopsy for diagnosis. Other chapters deal with methods of performing renal biopsy. Finally, there are chapters dealing

Department of Internal Medicine, Sanford School of Medicine, University of South

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

In conclusion, a word should be said about repeat renal biopsies. Repeat biopsies are encouraged to assess response to treatment such as in allograft rejection. Repeat biopsies are used to reassess those diseases such as lupus nephritis which can change course leading to new pathophysiology and demanding a change in therapeutic

logic diseases accounts for some of these newer entities.

with complications of renal biopsy.

Introductory Chapter: Renal Diseases

DOI: http://dx.doi.org/10.5772/intechopen.90067

strategy.

Author details

Edward T. Zawada

3

Dakota, Sioux Falls, United States

provided the original work is properly cited.

\*Address all correspondence to<EMAIL_ADDRESS>


**4. Time-dependent effects in tunneling**

Time-dependent deformations associated with rock tunneling are a reality that warrants further investigation and understanding and can be observed during excavation and/or after the construction period of the project.

## **4.1 Analysis of time-dependent rock masses using the convergenceconfinement method**

Understanding the nature and origin of deformations due to an underground opening requires, as [50] noted, both knowledge of the rock-support interaction and field data interpretation. This tunnel wall movement, also known as convergence, results from both the tunnel face advancement and the time-dependent behavior of the rock mass.

The Convergence-Confinement Method (CCM) is a two-dimensional simplified approach that can be used to simulate three-dimensional problems. Analytical solutions based on CCM (usually examine either the effect of tunnel advancement or the time-effect) could be partially used to select the final support. One may wonder if it could also be possible to simulate and replicate the complete problem. Timedependency is acting during the timeframe of construction impacts, the so-called Longitudinal Displacement Profiles (LDPs) for deformation estimation during tunnel advance. LDP is an accompanying tool used with the Ground Reaction Curves (GRC) used in the CCM to relate internal wall pressure relaxation to tunnel displacement. Suggested analytical solutions for LDPs [50], etc.) refer to elastic or elasto-plastic rock materials. **Figure 20** schematically illustrates the effect of both time and tunnel advancement on the LDP of a tunnel excavated in a visco-elastic medium. The tunnel's advance is simulated by reducing the internal pressure, pi, initially acting on the tunnel core (as p0). The rock responds by convergent deformations (via the GRC), which are, in turn, linked to the tunnel advance via the LDP. This aspect of time-dependency is also discussed, examined and further analyzed in this chapter.

Analytical and closed-form solutions that consider the time-dependent convergence have been proposed in the literature for supported and unsupported tunnels with linear and non-linear visco-elastic medium [51, 52], etc. Most of these formulations also consider the tunnel advance in the estimated total deformation yet are found to be impractical due to the complex calculations required [53, 54].

**Figure 21** illustrates the anticipated LDP of the tunnel displacement in an elasto-visco-elastic medium where no tertiary creep takes place. More ductile materials, as in the case of rock salt, can behave in such a manner. It is shown that when no time-effect is considered, the total displacements are underestimated, which can lead to erroneous calculations at the initial stages of the design process.

#### **Figure 20.**

*Schematic representation of the GRC of an elastic (t = 0) and a visco-elastic material (t > 0) and their relation to the LDP. Y-axis on the left refers to the internal pressure (pi) normalized to the in-situ pressure (p0), Y-axis on the right refers to the distance from the face (x) normalized to the tunnel radius (R) and X-axis refers to the radial displacement at a location x normalized to the maximum radial displacement due where t denotes time and subscripts e and ve refer to elastic and visco-elastic material, respectively.*

*Time-Dependent Behavior of Rock Materials DOI: http://dx.doi.org/10.5772/intechopen.96997*

**Figure 21.** *Schematic representation of the longitudinal displacement profile (LDP) in an elasto-visco-elastic medium.*


**Author details**

Tao Dong1,2\*, Yue Xu1,2 and Jingwen He1,2

1 State Key Laboratory of Space-Ground Integrated Information Technology, Beijing, China

2 Beijing Institute of Satellite Information Engineering, Beijing, China

\*Address all correspondence to<EMAIL_ADDRESS>
© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


2.1.3. Cu-Substituted MBG Microspheres

Cu-substituted MBG microspheres (nominal molar ratio Cu/Ca/Si=2/13/85, hereafter named as MBG\_Cu2%\_SD) were synthesized following the aerosol-assisted spray-drying method reported by Pontremoli, Boffito et al. [16]. Briefly, 2.030 g of Pluronic P123, acting as template, were dissolved in 85 g of ddH2O. Simultaneously, in a separate batch, a solution of 10.73 g of TEOS was pre-hydrolyzed under acidic conditions using 5 g of an aqueous HCl solution at pH 2. The solution with TEOS was then added drop-wise into the template solution and kept stirring for half an hour. Then, 0.163 g of CuCl2 and 1.86 g of Ca(NO3)2 · 4H2O were added. The final solution was stirred for 15 min and then sprayed with a Büchi, Mini Spray-Dryer B-290 (Büchi Labortechnik AG, Flawil, Switzerland), using N2 as atomizing gas (inlet temperature 220 ◦C, N2 pressure 60 mm Hg, feed rate 5 mL min−1). The obtained powder was finally calcined at 600 ◦C in air for 5 h at a heating rate of 1 ◦C min−1 using a Carbolite 1300 CWF 15/5 (Carbolite Ltd., Hope Valley, UK).


**7. Standard adjuvant therapy**

After maximally-safe surgical resection, the standard of care for GBM is a 6 week course of External Beam Focused Radiation Therapy with concurrent chemotherapy followed by 6 months of adjuvant chemotherapy.

With the support of Level IA evidence, fractionated focal radiotherapy (60 Gy, 30-33 fractions of 1.8-2 Gy) is the established radiation regimen after resection or biopsy of malignant gliomas [37]. The fundamental nature of the ionizing radiation utilized has, needless to say, not changed; however, leaps and bounds have been made in efforts to focus the beam, tailor it to the highly-serrated and convoluted contours of tumor, and limit the dose to nearby critical structures/tissue by the use of intensity-attenuated and image-guided technologies, all with positive effect.

The single first-line chemotherapeutic agent for GBM is temozolomide, an oral alkylating agent that exerts its anti-tumorigenic effect by methylating/alkylating DNA at the N-7/O-6 positions of guanine residues, thereby causing irreparable damage to (tumor) DNA and instigating the process of tumor cell death. The benefits of the addition of concurrent with adjuvant chemo‐ therapy to the foundation of radiation therapy were demonstrated by a seminal landmark study by Stupp *et al* that showed a 14.6 to 12.1 month median overall survival benefit and showed a sustained survival advantage of 9.8% vs 1.9% at 5 year analysis (Figure 7) [35].

High-dose corticosteroids have a role to play in reduction of tumor-associated edema and associated symptoms but are not indicated for long periods of time [37]. There is an established role for anti-seizure therapy in patients who present with seizures, but the role for seizure prophylaxis after surgery is only indicated in symptomatic patients. It ought to be kept in mind that many anti-epileptics, particularly of the first generation (e.g. phenytoin, carbamazepine), may decrease the serum concentration of certain chemotherapy agents by dint of inducing increased hepatic metabolism [37].

As evinced by the yet-sobering statistics on overall GBM survival/patient outcome, there are many-a-challenge and obstacle that remain in treatment, especially regarding the development of resistance to both radiation therapy and, more so, to temozolomide chemotherapy.


*4.5. Coatings with the Addition of Two or More Elements*

Quarternary and higher-order systems have been explored to further optimise coating properties. However, this has also been pursued from an industrial perspective dealing with patent issues to obtain unique selling points (USPs) or to supersede patents from competitors. However, the complexity quickly increases, and there is the potential for cross-reactions between the alloying elements. Even if the results achieved do not generally outperform the simpler coatings, a study of that research will reveal indicators of potential directions for coating development. A detailed discussion is beyond the scope of this paper; however, selected publications on Al-Cr based multinary coatings are listed below.

Si-Mo sputtered [142], Si-Ni sputtered [143,144], Si-Ti arc [145,146], Si-W arc [78,135], Si-W sputtered [136], Si-Ni sputtered [137], Si-C sputtered [133,147], Si-B sputtered [134], Si-Mg [148], Ti-C sputtered [114], MoCu sputtered [106], Si-Y-O sputtered [138], Ti-Si-Y arc [149], and Nb-Ti-Si sputtered [150].

In addition, even high-entropy coating modifications are the focus of R&D activities [150,151].


**Author details**

Edgar Antonio Reyes-Montaño\* and Nohora Angélica Vega-Castro

\*Address all correspondence to<EMAIL_ADDRESS>
Department of Chemistry, Protein Research Group, National University of Colombia, Bogotá, Colombia