Impedance Analysis Method Research Articles

Agreement Between Different Body Composition Methods And Dual-energy X-ray Absorptiometry In Adults

The assessment of body composition is often used in clinical practice for nutritional assessment and monitoring. The gold standard method, dual energy X-ray absorptiometry (DXA), is hardly feasible in routine clinical practice. The bioelectrical impedance analysis (BIA) method is a common applicable alternative because it is accessible and easy to use. In addition, methods that use artificial intelligence to assess body composition through photos (AI-Photo) began to emerge as cheaper alternatives than BIA. However, few studies have evaluated the agreement of different methods with DXA. PURPOSE: Evaluate the agreement between one IA-Photo method, three BIA devices and DXA for estimating body fat percent (BF%) in adults. METHODS: A total of 215 Brazilian adults, aged between 18 and 65 years, BMI from 18 to 35 kg/m2 and sedentary and physically active. Volunteers were evaluated by the IA-Photo method (Shaped, Rio de Janeiro, Brasil), bioimpedance scales of the inBody 270 (Biospace, California, USA), inBCA F-500 (Shenzhen, China), Omron HBF-514 (Kyoto, Japan) models and DXA (GE, Madison, USA) at an interval of 1 minute between the methods. The method of Bland-Altman (BA) was used to evaluate the identify the 95% limits of agreement and BIAS between IA-Photo method and BIA devices with DXA. Lin's Concordance Correlation Coefficient (CCC) was utilized to evaluate concordance between each method with DXA. RESULTS: Confidence interval values are represented by the dotted line and the BIAS by the dashed line (Figure 1). The BIAS value of the %error between methods and DXA ranged from 3.33 (Shaped) to 12.2 (inBody-270). CCC was 0.96; 0.93; 0.91 and 0.45 for the Shaped, Omron, inBody-270 and inBCA F-500 methods. The inBody and Omron model BIAs presented a significant p value for the linear regression in the BA plot, indicating a proportion bias in relation to the BF%. CONCLUSIONS: Shaped and Omron had greater agreement with the DXA compared to inBody-270 and inBCA F-500 for estimating BF%.

Fuzzy piecewise coordinated control and stability analysis of the photovoltaic‐storage direct current microgrid

In order to ensure the safe and reliable operation of photovoltaic-storage DC microgrid in islanded mode, this paper proposes a piecewise coordinated control strategy based on fuzzy logic to independently judge the working mode of microgrid. Firstly, according to the operation characteristics of microgrid, the device-level control of each unit (photovoltaic, energy storage and load) is designed successively. Then, according to the requirement of supply and demand balance of microgrid, fuzzy logic is introduced to realize the independent division of threshold nodes on the basis of piecewise control, so as to ensure the fast switching of working mode and stable operation of the system in various complex environments, that is system-level control. And the method of impedance analysis is used to analyze the stability of microgrid under different working modes. Finally, the effectiveness and feasibility of the proposed coordination control strategy are verified by MATLAB/Simulink simulation results.

The interactive effect of vitamin D3 supplementation and vitamin D receptor polymorphisms on weight and body composition in overweight women with hypovitaminosis D: a randomized, double-blind, placebo-controlled clinical trial.

Different responses to vitamin D supplementation may be due to genes involved in vitamin D metabolism, including the vitamin D receptor (VDR) gene. The present study aimed to determine the interactive effect of vitamin D supplementation and VDR polymorphisms, including FokI (rs2228570) and BsmI (1544410) on weight and body composition in overweight women with hypovitaminosis D. This study comprised two phases: a double-blind, randomized and a before-after clinical trial. In the first phase, 50 healthy overweight women aged 20-45 years with hypovitaminosis D were randomly categorized into intervention and control groups and were given 50000 IU/w vitamin D3 or placebo for 12 weeks. In the second phase, 75 women received 50000 IU/w of vitamin D3 for 12 weeks. All variables were measured at baseline and after 12 weeks. Circulating 25(OH)D was measured using an ELISA kit. Anthropometric indices were calculated according to standard protocol (WHO-TRH-854). Body composition was determined using the body impedance analysis method. The VDR polymorphisms were detected using the PCR sequence. Supplementation resulted in a significant increase in the level of 25(OH)D in the intervention group but did not affect the anthropometric profile of the subjects. When considering FokI genotypes, carriers of the FF genotype had higher fat mass reduction than carriers of Ff+ff genotypes.

The utility of bioelectrical impedance analysis to assess nutritional status of patients with severe motor and intellectual disabilities.

We aimed to evaluate the usefulness of the bioelectrical impedance analysis method in the nutritional assessment of patients with severe motor and intellectual disabilities. Eighty patients with severe motor and intellectual disabilities were included in the study, and the samples collected were biochemical and body composition data were obtained from regular blood samples and using the bioelectrical impedance analysis method. Nutritional status was scored from the biochemical data, and the subjects were divided into three groups: well-nourished, mildly malnourished, and moderately malnourished. The data that changed significantly with worsening nutritional status were serum albumin, total lymphocyte count, skeletal muscle ratio, phase angle, edema index, and body cell mass normalized by height. There were no significant differences in total lymphocyte count and body cell mass normalized by height between the groups. phase angle and edema index, which have been reported to be useful in nutritional assessment, responded sensitively to this nutritional score. Skeletal muscle ratio, which has been reported less frequently, has also been suggested to be useful in the nutritional assessment of severe motor and intellectual disabilities. Low skeletal muscle ratio, low phase angle, and high edema index were significantly suggestive of malnutrition in patients with severe motor and intellectual disabilities, and correlated significantly with biochemical data, a conventional nutritional index. Therefore, bioelectrical impedance analysis is a useful method for nutritional assessment in patients with severe motor and intellectual disabilities.

Low Cardiorespiratory Fitness, Muscular Fitness, and Flexibility Are Associated with Body Fat Distribution and Obesity Risk Using Bioelectrical Impedance in Taiwanese Adults.

In terms of public health, obesity and overweight have become major concerns worldwide. Nevertheless, regarding body composition, it is important to have a more precise understanding of the fat-to-muscle ratio. Hence, this study aimed to adopt bioelectrical impedance measurements to test body fat percentage (BF%) and to determine the associations between health-related physical fitness and both body fat (BF) distribution and BF obesity risk in Taiwanese adults. We conducted a cross-sectional study and reviewed data derived from Taiwan’s Scientific Physical Fitness Survey. From the database, responses from 17,970 participants aged 23–64 years were collected in this study. Each participant completed a series of health-related physical fitness measurements, including cardiorespiratory fitness (3 min of a progressive knee-up and step (3MPKS) test), muscular fitness (hand-grip strength), and flexibility (sit-and-reach test). The BF% of each participant was assessed using the bioelectrical impedance analysis method. BF% was negatively associated with low performance on the 3MPKS (β = 11.314, p < 0.0001 for men; β = 12.308, p < 0.0001 for women), hand-grip strength (β = 2.071, p < 0.0001 for men; β = 0.859, p < 0.0001 for women), and sit-and-reach (β = 0.337, p = 0.008 for women) tests but was positively associated with sit-and-reach (β = −0.394, p = 0.004 for men). A risk of BF obesity for low performance of 3MPKS (odds ratio (OR) = 26.554, p < 0.0001 for men; OR = 25.808, p < 0.0001 for women), hand-grip strength (OR = 1.682, p < 0.0001 for men; OR = 1.234, p < 0.0001 for women), and sit-and-reach (OR = 1.142, p = 0.007 for women) tests was observed. These results suggest that low levels of cardiorespiratory fitness, muscular fitness, and flexibility are associated with an increased risk of BF obesity.

The bioimpedance phase angle may be associated with frailty in rheumatoid arthritis patients: Results from a prospective, cohort study.

This study investigated whether the phase angle (PhA) on bioelectrical impedance analysis is related to frailty in rheumatoid arthritis (RA) patients. Data from a prospective cohort study of RA patients were analysed. The PhA was assessed by the bioelectrical impedance analysis method, and frailty was assessed by the Kihon Check List (KCL) annually. The cut-off value of the PhA for frailty was calculated by receiver-operating characteristic analysis. The relationships between the PhA and frailty were evaluated by logistic regression analysis. The relationships between the change in PhA and frailty status and the KCL score were evaluated by analysis of covariance and multiple regression analysis. A total of 170 patients (81.2% female, 66.2 ± 13.1 years) were included in the analysis. A PhA of less than the cut-off for frailty was significantly associated with frailty (odds ratio: 4.75, 95% confidence interval: 1.86, 12.17). The change in the PhA was significantly associated with the change in the KCL score (β = -0.15). In robust patients, there was a significant difference in the rate of change of the PhA between the group that became pre-frail in the next year and the group that remained robust. The PhA may be associated with frailty in RA patients.

High-precision identification of polarization processes of distribution of relaxation times by polarization curve model for proton exchange membrane fuel cell

The distribution of relaxation times (DRT) is a promising impedance analysis method that is often used to decompose polarization processes with different time constants. However, uncertainty in interpreting polarization processes by DRT arises from two main sources: (1) overlap of the DRT peaks and (2) lack of peak identification methods. Thus, herein, a high-precision polarization process identification method based on polarization curve model involving electrochemical processes of proton exchange membrane fuel cell (PEMFC) was proposed by establishing the intrinsic relationship between polarization curve and electrochemical impedance spectroscopy (EIS) and comparing the quantitative relationship between the steady-state resistance obtained by the inverse slope of polarization curve model and each DRT peak. Then, an improved DRT method based on the characteristic frequency resolution optimization was suggested to avoid the overlap of the DRT peaks in case of the narrow interval time constants of the electrochemical system. Based on these two methods, each polarization resistance of PEMFC and DRT peak was quantitatively analyzed. First, it was determined that the total steady-state resistance has a resistance recovery compared to the low-frequency intercept resistance obtained by the improved DRT method, because of the ultra-low-frequency pseudo-inductive behavior arising mainly from dissolved water transport. Second, the peak with a characteristic frequency in the range of 7–54 Hz corresponds to two processes: mass transport and dissolved water transport. The peak with a characteristic frequency in the range of 3–20 Hz represents charge transfer. Interestingly, the two DRT peaks in the low-frequency region overlapped at 400 mA cm−2 because their characteristic frequencies changed in opposite directions with the current density. Moreover, the peak with a high characteristic frequency in the range of 250–300 Hz corresponds to proton transport of the catalyst layer ionomer. The methodology based on the model lays the foundation for identifying the distribution of the relaxation times for PEMFCs.

Research on adaptive segmented control strategy used in direct-drive wave power generation systems

The problem of unstable output power in direct-drive wave power generation systems (DDWPGS) caused by violent power variation in one cycle of wave is common. The wave power fluctuates violently in a short time, and the lower the frequency, the higher the amplitude. Energy storage devices are usually applied to smooth the power and stabilize the system. This paper proposed an adaptive segmented control strategy (ASCS). It adaptively divided the system voltage into five symmetrical segments and regulated the reference power based on the VMD decompose results according to the different segments. The impedance analysis method (IAM) is implemented to verify its stability. The simulation results confirmed that it can not only automatically adjust the output of the energy storage device to adapt to the frequency and amplitude of wave power signal, but also ensure the safe operation of the system under the impact of charging load and wave power.

PB2181: DOES SARCOPENIA INFLUENCE THE SUCCESS OF HEMATOPOIETIC STEM CELL TRANSPLANTATION?

Background: Sarcopenia has been widely studied in solid tumors. However, its presence and prognostic significance in hematological malignancies and transplantation cases are not clear enough. Aims: In this study, we aimed to evaluate the presence of sarcopenia and its effects on transplantation success in patients undergone stem cell transplantation. Methods: Twenty-four patients who had autologous or allogenic stem cell transplantation between May 2021 and January 2022 were included in this study. Patients who had a secondary non-hematological malignancy, neuropathy or paralysis, chronic liver/kidney disease, glomerular filtration rate <60 ml/min, congestive heart failure were excluded. Patients with a body mass index (BMI) <20.0 kg/m2; 20.0 - 24.9 kg/m2; 25.0 -29.9 kg/m2; > 30 kg/m2 were considered as underweight; normal weight; overweight and obese respectively. Low muscle mass was evaluated with the Bioelectrical Impedance Analysis (BIA) method. TANITA-SC-240MA device was used to measure body composition by BIA method. The low skeletal muscle mass index (SMI) was considered as ≤10.76 kg/m2 in men and ≤ 6.76 kg/m2 in women. The muscle strength was evaluated by using a handgrip dynamometer (TAKEI 5401 Hand Dynamometer, 100 kg). The average of 3 measurements were calculated and <30 kg in men and <20 kg in women were considered as low muscle strength. Patients were evaluated by bioelectrical impedance analysis (BIA), hand grip test, sit-stand test within 1 week before administration of preparative regimens for stem cell transplantation. The neutrophil and trombocyte engraftment days, presence of bacteremia, need for thrombocyte infusion and hospitalization time were analyzed due to the presence of sarcopenia. Results: 24 patients were included in our study. The median age of the patients was 48 (23-67), and 16 patients (66%) were female. Three patients (12.5%) were 65 years or older. Two patients had autologous stem cell transplantation previously and were undergone allogeneic transplantation due to the relaps. Among all patients, 5 patients (20.8%) were obese, 5 patients (20.8%) were overweight, 9 patients were (37.5%) normal weight and 5 patients were (20.8%) underweight. 4 patients (16.6%) were determined as sarcopenic. According to the BMI values of the sarcopenic patients, 3 were underweight and 1 was obese. Muscle strength and SMI were significantly lower in patients with sarcopenia (p: 0.035; p: 0.01, respectively) (Table 1). There was no significant relationship between the presence of sarcopenia and gender, age, BMI, diagnosis, neutrophil and platelet engraftment days. Although the length of hospitalization in patients with sarcopenia seemed to be longer, it was not statistically significant (p=0.83) (Table 1). The administration of parenteral nutrition was more frequent in patients with diabetes mellitus. When the patients were evaluated in terms of mortality on the 100th day, this value was found to be 50% in the group with sarcopenia. Image:Summary/Conclusion: Sarcopenia is more common in patients who are candidates for allogenic transplantation compared to autologous transplantation. However, since the number of patients included in our study was low, the effect of sarcopenia on transplantation success could not fully clarified. Prospective studies with larger number of patients are needed on this subject.

State of Body Bioimpedance Parameters after Massage Therapy

Massage therapy is commonly non-invasive, non-harmful, economical, pleasant, and greatly appreciated by the recipients. The Bioelectrical Impedance Analysis (BIA) method has been identified as one of the fastest, simple, and safest non-invasive techniques for measuring the body bioimpedance parameters after the massage therapy. This study aims to evaluate massage therapy's effect on the body bioimpedance parameters of the subject using the Bioelectrical Impedance method. The male bioimpedance parameters were measured before and after massage therapy by using the Microtest 6378 Impedance Analyzer. The measured bioimpedance parameters were capacitance (C), phase angle (θ), impedance (Z), resistance (R), and reactance (X). The other body composition parameters were then calculated, including basal metabolic rate (BMR), fat mass (FM), fat free mass (FFM), total body water (TBW) intracellular water (ICW), and extracellular water (ECW). The measurements of bioimpedance and body composition parameters were significantly different before and after the massage therapy. In addition, the massage therapy increased the capacitance, phase angle, impedance, resistance, reactance, fat mass, and intracellular water. However, the massage therapy decreased the BMR, FFM, TBW, and ECW. The study findings show that massage therapy has a significant impact on bioimpedance and body composition parameters in maintaining good health.

Serum irisin levels in newly diagnosed type-II diabetic patients: No association with the overall diet quality but strong association with fruit intake.

This study aimed to investigate the serum irisin levels and diet quality of newly-diagnosed type 2 diabetes mellitus (T2DM) patients in comparison with healthy controls and to identify the correlations between serum irisin levels with diet quality, anthropometric measurements and biochemical parameters. This case-control study was conducted with 38 newly-diagnosed T2DM patients and 38 healthy control individuals. Diet quality was calculated from the semi-quantitative food frequency questionnaire by using the Healthy Eating Index (HEI) 2015. The anthropometric measurements were taken and body composition was analyzed with bioelectric impedance analysis (BIA) method. Biochemical parameters and serum irisin levels were analyzed in blood samples which were obtained after overnight fasting. Irisin levels were higher in the T2DM group compared to the healthy control group (2.57±0.44ng/mL and 2.15±0.44ng/mL, respectively; p<0.001). The optimal cut-off value for irisin to predict T2DM was 2.195ng/mL (specificity=71.1%, sensitivity=78.9%). In both groups, irisin levels were not associated with overall HEI 2015; however, they were positively associated with total and whole fruit scores in the T2DM group (p<0.05). After adjustment according to age, sex and BMI, in the T2DM group HDL cholesterol positively affected by irisin levels, while in the control group triglyceride positively affected irisin levels (p<0.05). High levels of irisin in newly diagnosed T2DM patients compared to healthy individuals indicate that irisin may have a role in the monitoring and treatment of T2DM. Though irisin levels were not associated with total diet quality, they were associated with fruit consumption.

Stability Modeling of a Three-Terminal MMC-HVDC Transmission System

Multi-terminal modular multilevel converter (MMC) power transmission is the current development trend in DC transmission. However, owing to its fast control and dynamic characteristics, it may interact with the other inductive devices or the grid and cause stability issues. This paper describes the use of the impedance analysis method in the frequency domain to analyze system stability. First, the multi-harmonic linearization method is used to model the impedance of a three-terminal MMC system. To make the model more accurate, the modeling considers the effect of frequency coupling caused by an asymmetric controller and the AC sampling site position. This paper then proposes an equivalent method of the grid impedance for the three-terminal system that can accurately judge the stability of the grid-connected system when the AC side is coupled. This work provides a theoretical basis for the prediction and suppression of the oscillation of MMC grid-connected system with coupling on the AC side. Finally, a three-terminal MMC model is built in Matlab/Simulink and the Nyquist stability criterion is used to verify the correctness of the analysis.

Comparing of Frequency Shift and Impedance Analysis Method Based on QCM Sensor for Measuring the Blood Viscosity.

Blood viscosity measurements are crucial for the diagnosis of cardiovascular and hematological diseases. Traditional blood viscosity measurements have obvious limitations because of their expensive equipment usage and large sample consumption. In this study, blood viscosity was measured by the oscillating circuit method and impedance analysis method based on single QCM. In addition, the effectiveness of two methods with high precision and less sample is proved by the experiments. Moreover, compared to the result from a standard rotational viscometer, the maximum relative errors of the proposed oscillating circuit method and impedance analysis method are ±5.2% and ±1.8%, respectively. A reliability test is performed by repeated measurement (N = 5), and the result shows that the standard deviation about 0.9% of impedance analysis is smaller than that of oscillating circuit method. Therefore, the impedance analysis method is superior. Further, the repeatability of impedance analysis method was evaluated by regression analysis method, and the correlation coefficient R2 > 0.965 demonstrated that it had excellent reproducibility.

Impedance characteristics investigation and oscillation stability analysis for two-stage PV inverter under weak grid condition

In order to obtain impedance characteristics of the photovoltaic (PV) inverter and reveal potential stability issues of the PV inverter connected to a weak grid, a complete impedance model of the two-stage PV inverter is established in this paper. The model includes the PV arrays, front-end Boost converter, and rear-end inverter with output LCL filter. The impedance modeling of the PV inverter is derived at different interfaces of DC-link and point of common coupling (PCC), where the DC impedance characteristic at DC-link and d-q axis impedance feature at AC side are both investigated. It is worth noting that the DC output impedance of front-end circuit behaves as a first-order low-pass filter, and it is mainly influenced by the DC-link capacitor. Moreover, a significant feature is found that a reduced integral gain in the outer voltage loop may cause a negative resistance and capacitive impedance in d-axis impedance component. In addition, based on the impedance analysis method, the oscillation stability issues of the grid-connected PV inverter in case of a weak grid are evaluated by different divisions of source-load subsystems. It is demonstrated that the increase of the PLL bandwidth and the decrease of the integral gain of the outer voltage loop will both lead to the oscillation of the PV inverter. Moreover, the increase of the output capacity will deteriorate the stability margin, resulting in the high frequency oscillation of the system. Finally, the impedance model and the stability analysis are verified by the simulation results implemented in PSCAD/EMTDC platform.

Novel Insight into the Relationship Between Muscle-Fat and Bone in Type 2 Diabetes Ranging from Normal Weight to Obesity.

ObjectiveDecreased bone mineral density (BMD) is a common complication in individuals with type 2 diabetes mellitus (T2DM). Body weight, mainly consisting of muscle and fat, is the main determinant of BMD and fracture risks but does not accurately describe nutritional status. Most studies suggest that skeletal muscle mass (SMM) promotes BMD, while body fat mass (BFM) decreases BMD. However, the combined effect of SMM and BFM on BMD is elusive. Thus, the study aims to explore the combined effect of fat and muscle by the ratio index SMM/BFM on BMD in T2DM.MethodsBFM and SMM were measured by the bioelectrical impedance analysis (BIA) method among 593 T2DM individuals ranging from normal weight and obesity. BMD was analyzed by DXA. Novel non-linear generalized additive models (GAMs) were used as the statistical analysis method.ResultsThe results demonstrated that BMD T score/Z score of both femur and lumbar vertebrae were significantly higher and waist–hip ratio (WHR) was significantly lower in the high SMM/BFM group of both normal weight and overweight groups in T2DM individuals. Hence, SMM/BFM might be a good factor indicating BMD in different weight ranges. Additionally, the relationship between muscle fat and BMD was not linear. Notably, this correlation was not influenced by hyperglycemia in T2DM since different analytic models adjusted with the age, gender, BMI and HbA1c were adopted in this study. Furthermore, the impact of trunk fat (central, visceral fat most) and non-trunk fat (peripheral, the sum of subcutaneous limb fat most) on BMD was inconsistent. BMD presented unlimited reduction with trunk BFM increasing, while sustaining minimal diminishment with non-trunk BFM accumulation.ConclusionOur study provided a novel viewpoint relationship between muscle-fat and bone, and SMM/BFM might be a potential biomarker for bone health and clinical treatments of diabetes and related metabolic syndromes.

Comparison of Body Mass Index and Bioelectric Impedance Analysis Methods in the Evaluation of Body Composition and Obesity in Women

Comparison of Body Mass Index and Bioelectric Impedance Analysis Methods in the Evaluation of Body Composition and Obesity in Women

EFFECT OF ALBUMIN SOLUTION ON THE BODY WATER COMPARTMENTS IN WOMEN WITH PREECLAMPSIA

Abstract. Preeclampsia is a multisystem disorder initially caused by endothelial cell dysfunction, which results in reduced intravascular volume and hypervolemia in the interstitial space. Albumin stabilizes the endothelial glycocalyx and, therefore, ensures the integrity of the vascular barrier.&#x0D; The aim of the study. To investigate the effect of albumin - saluretic infusion on the body water compartments in women with preeclampsia.&#x0D; Materials and methods. 60 women were examined during the study. The first group included women with preeclampsia who were provided with standard infusion therapy. The second group: women with preeclampsia who were provided with standard infusion therapy and continuous infusion of 20% albumin (8 ml/h on the 1st day; 4 ml/h on the 2nd and 3rd days) and furosemide (0.05 mg/kg/h on the 1st day; 0.025 mg/kg/h on 2nd and 3rd days) solution for 72 hours simultaneously. The method of non-invasive bioelectrical impedance analysis was used to measure the body water compartments at 5 stages: onset of labor, 1st, 3rd, 5th and 7th day after the birth.&#x0D; Results. Our study showed the method of providing a continuous albumin - saluretic infusion for 72 hours in addition to the standard infusion therapy. The effectiveness and advisability of the method was proved by changes in body water compartments. On the 3rd day of monitoring, the volume of extracellular fluid decreased by 19.6% (p&lt;0.001), and by 7th day - by 24.6% (p&lt;0.001). At the same time, the volume of interstitial fluid decreased by 2.78 l, or 31.7% (p&lt;0.001) compared to the initial level, significantly approaching the interstitial fluid volume in non-pregnant women. Clinically, this decrease helped in regression of the edema syndrome and stabilization of blood pressure to the level of normotension.&#x0D; Conclusions. Providing a continuous infusion of 20% albumin and furosemide solution for 72 hours in addition to the standard infusion therapy normalizes the body water compartments in women with preeclampsia by the 7th day of the postpartum period.

Association of Individuals’ Chronotypes With Obesity and Body Composition in Tehrani Adults in 2020

Objective: Individual’s preferences in time for sleeping, waking up, doing physical and mental activity is dependent on chronotypes. According to these preferences, individuals are categorized to morningness, intermediate, and eveningness chronotype. Recently, it has been suggested that chronotypes are involved in regulation of sleep, appetite, and some metabolic factors. The aim of this study was to investigate the association between chronotypes, obesity, body fat, and lean mass in Tehrani adults.Methods: It was a cross-sectional study on 353 adults aged 18–60 years who referred to Tehran community centers. After anthropometric measurements and collecting data on general information, choronotype, physical activity and 3-day food recalls, fat mass, and lean mass were measured using the method of bioelectrical impedance analysis. SPSS 21 was used to statistical analysis.Results: Of total 353 participants, 11%, 47.6%, and 41.4% had eveningness, intermediate, and morningness chronotypes, respectively. The mean age of individuals with morningness and intermediate was higher than those with eveningness. The prevalence of eveningness in men was higher than in women (p=0.001). Fat mass and lean mass in individuals with eveningness type were higher and lower than those with morningness, respectively (p&lt;0.05). Body mass index and waist circumference showed no significant difference among chronotypes.Conclusion: Eveningness type is associated with increase in fat mass and decrease in lean mass. The effects of chronotype on body fat and lean mass are independent of obesity.

Stability analysis and control for power electronic transformer with FRT capability

In this paper, a power electronic transformer (PET) topology with the fault ride-through (FRT) capability is presented. In the PET, modular multilevel converters (MMCs) are adopted to provide medium voltage DC (MVDC) ports. The positive and negative isolated modular multilevel DC converters (IMMDCs) are cascaded respectively with the positive and negative MVDC bus. Under pole-to-ground (PTG) fault condition, the healthy pole of MMC and the healthy IMMDC can operate as normal with the capability of half rated active power transmission. As a cascaded system, the stability of the PET may be affected by the impedance-mismatching of the cascaded converters. Therefore, based on impedance analysis method, the stability analysis of the proposed PET is developed. Then, the stability control method based on series virtual resistance is presented to improve the PET stability. Besides, to fast the dynamic respond speed, a coordinated control scheme based on low voltage DC port current feedforward is introduced. Finally, the presented PET topology and the control strategy is verified by simulations in MATLAB/Simulink.

Investigating Body Mass Index and Body Composition in Patients with Schizophrenia: A Case-Control Study.

Background Antipsychotics exert metabolic side effects, and prolonged treatment with antipsychotics causes changes in body weight and muscle composition. Nevertheless, reports on the changes in body composition of patients with schizophrenia have been limited. This study is aimed at comparing the body mass index and body composition of patients with schizophrenia with healthy individuals in Indonesia. Methods A total of 195 patients with schizophrenia (148 males and 47 females) and 195 healthy individuals matched by gender were recruited. Using the Bioelectrical Impedance Analysis method, the participants' body compositions were measured. Results Compared to healthy individuals, the patient group exhibited a higher rate of underweight as well as a lower rate of overweight and obesity. Multiple regression analysis confirmed the associations between the body mass index and all measured body compositions. Furthermore, the diagnosis of schizophrenia is significantly associated with lower muscle mass, lower bone mass, higher basal metabolic rate, older metabolic age, and higher total body water. Conclusions The results showed that patients with schizophrenia are at a greater risk of a lower quality of certain components of body composition. Priority should be given to research that addresses increasing the patient's level of physical activity.