AIM To evaluate the prognostic value of the phase angle(PA)obtained from bioelectrical impedance analysis(BIA)for mortality prediction in patients with cirrhosis.METHODS In total,134 male cirrhotic patients prospectiv...AIM To evaluate the prognostic value of the phase angle(PA)obtained from bioelectrical impedance analysis(BIA)for mortality prediction in patients with cirrhosis.METHODS In total,134 male cirrhotic patients prospectively completed clinical evaluations and nutritional assessment by BIA to obtain PAs during a 36-mo follow-up period.Mortality risk was analyzed by applying the PA cutoff point recently proposed as a malnutrition marker(PA≤4.9°)in Kaplan-Meier curves and multivariate Cox regression models.RESULTS The patients were divided into two groups according to the PA cutoff value(PA>4.9°,n=73;PA≤4.9°,n=61).Weight,height,and body mass index were similar in both groups,but patients with PAs>4.9°were younger and had higher mid-arm muscle circumference,albumin,and handgrip-strength values and lower severe ascites and encephalopathy incidences,interleukin(IL)-6/IL-10 ratios and C-reactive protein levels than did patients with PAs≤4.9°(P≤0.05).Forty-eight(35.80%)patients died due to cirrhosis,with a median of 18 mo(interquartile range,3.3-25.6 mo)follow-up until death.Thirty-one(64.60%)of these patients were from the PA≤4.9°group.PA≤4.9°significantly and independently affected the mortality model adjusted for Model for End-Stage Liver Disease score and age(hazard ratio=2.05,95%CI:1.11-3.77,P=0.021).In addition,Kaplan-Meier curves showed that patients with PAs≤4.9°were significantly more likely to die.CONCLUSION In male patients with cirrhosis,the PA≤4.9°cutoff was associated independently with mortality and identified patients with worse metabolic,nutritional,and disease progression profiles.The PA may be a useful and reliable bedside tool to evaluate prognosis in cirrhosis.展开更多
Background:Fluid overload(FO)after resuscitation is frequent and contributes to adverse outcomes among postinjury open abdomen(OA)patients.Bioelectrical impedance analysis(BIA)is a promising tool for monitoring fluid ...Background:Fluid overload(FO)after resuscitation is frequent and contributes to adverse outcomes among postinjury open abdomen(OA)patients.Bioelectrical impedance analysis(BIA)is a promising tool for monitoring fluid status and FO.Therefore,we sought to investigate the efficacy of BIA-directed fluid resuscitation among OA patients.Methods:A pragmatic,prospective,randomized,observer-blind,single-center trial was performed for all trauma patients requiring OA between January 2013 and December 2017 to a national referral center.A total of 140 postinjury OA patients were randomly assigned in a 1:1 ratio to receive either a BIA-directed fluid resuscitation(defined as BIA)protocol that included fluid administration with monitoring of hemodynamic parameters and different degrees of interventions to achieve a negative fluid balance targeting the hydration level(HL)measured by BIA or a traditional fluid resuscitation(TRD)in which clinicians determined the fluid resuscitation regimen according to traditional parameters during 30 d of intensive care unit(ICU)management.The primary outcome was the 30-day primary fascial closure(PFC)rate.The secondary outcomes included the time to PFC,postoperative 7-day cumulative fluid balance(CFB)and adverse events within 30 d after OA.The Kaplan–Meier method and the log-rank test were utilized for PFC after OA.A generalized linear regression model for the time to PFC and CFB was built.Results:A total of 134 patients completed the trial(BIA,n=66;TRD,n=68).The BIA patients were significantly more likely to achieve PFC than the TRD patients(83.33%vs.55.88%,P<0.001).In the BIA group,the time to PFC occurred earlier than that of the TRD group by an average of 3.66 d(P<0.001).Additionally,the BIA group showed a lower postoperative 7-day CFB by an average of 6632.80 ml(P<0.001)and fewer complications.Conclusions:Among postinjury OA patients in the ICU,the use of BIA-guided fluid resuscitation resulted in a higher PFC rate and fewer severe complications than the traditional fluid resuscitation strategy.展开更多
An alternative technique for crack detection in a Timoshenko beam based on the first anti-resonant frequency is presented in this paper. Unlike the natural frequency, the anti-resonant frequency is a local parameter r...An alternative technique for crack detection in a Timoshenko beam based on the first anti-resonant frequency is presented in this paper. Unlike the natural frequency, the anti-resonant frequency is a local parameter rather than a global parameter of structures, thus the proposed technique can be used to locate the structural defects. An impedance analysis of a cracked beam stimulated by a harmonic force based on the Timoshenko beam formulation is investigated. In order to characterize the local discontinuity due to cracks, a rotational spring model based on fracture mechanics is proposed to model the crack. Subsequently, the proposed method is verified by a numerical example of a simply-supported beam with a crack. The effect of the crack size on the anti-resonant frequency is investigated. The position of the crack of the simply-supported beam is also determined by the anti-resonance technique. The proposed technique is further applied to the ＂contaminated＂ anti-resonant frequency to detect crack damage, which is obtained by adding 1-3% noise to the calculated data. It is found that the proposed technique is effective and free from the environment noise. Finally, an experimental study is performed, which further verifies the validity of the proposed crack identification technique.展开更多
Simultaneous impedance analysis of three one-face sealed resonating piezoelectric quartz crystals (PQCs) in parallel is proposed through admittance measurements of the three PQCs on one impedance analyzer and then non...Simultaneous impedance analysis of three one-face sealed resonating piezoelectric quartz crystals (PQCs) in parallel is proposed through admittance measurements of the three PQCs on one impedance analyzer and then non-linear fitting according to the parallel combination of three Butterworth-Van Dyke circuits. Responses of each PQC obtained from the three-PQC mode agreed well with those measured separately in series sucrose aqueous solutions. This novel method has been used for the study of depletion-layer effect during ferri-/ferrocyanide electrochemical reactions.展开更多
To facilitate rapid analysis of the oscillation stability mechanism in modular multilevel converter-based high voltage direct current(MMC-HVDC)systems and streamline the simulation process for determining MMC impedanc...To facilitate rapid analysis of the oscillation stability mechanism in modular multilevel converter-based high voltage direct current(MMC-HVDC)systems and streamline the simulation process for determining MMC impedance characteristics,a simplified mathematical simulation model for MMC closed-loop impedance is developed using the harmonic state space method.This model considers various control strategies and includes both AC-side and DC-side impedance models.By applying a Nyquist criterion-based impedance analysis method,the stability mechanisms on the AC and DC sides of the MMC are examined.In addition,a data-driven oscillation stability analysis method is also proposed,leveraging a global sensitivity algorithm based on fast model results to identify key parameters influencing MMC oscillation stability.Based on sensitivity analysis results,a parameter adjustment strategy for oscillation suppression is proposed.The simulation results from the MATLAB/Simulinkbased MMC model validate the effectiveness of the proposed method.展开更多
Wide-band oscillations have become a significant issue limiting the development of wind power.Both large-signal and small-signal analyses require extensive model derivation.Moreover,the large number and high order of ...Wide-band oscillations have become a significant issue limiting the development of wind power.Both large-signal and small-signal analyses require extensive model derivation.Moreover,the large number and high order of wind turbines have driven the development of simplified models,whose applicability remains controversial.In this paper,a wide-band oscillation analysis method based on the average-value model(AVM)is proposed for wind farms(WFs).A novel linearization analysis framework is developed,leveraging the continuous-time characteristics of the AVM and MATLAB/Simulink’s built-in linearization tools.This significantly reduces modeling complexity and computational costs while maintaining model fidelity.Additionally,an object-based initial value estimation method of state variables is introduced,which,when combined with steady-state point-solving tools,greatly reduces the computational effort required for equilibrium point solving in batch linearization analysis.The proposed method is validated in both doubly fed induction generator(DFIG)-based and permanent magnet synchronous generator(PMSG)-based WFs.Furthermore,a comprehensive analysis is conducted for the first time to examine the impact of the machine-side system on the system stability of the nonfully controlled PMSG-based WF.展开更多
followed by sintering-annealing treatments to form the bulk-phase.X-ray diffraction analysis revealed that all ceramics were crystallized in the orthorhombic perovskite structure with Pbnm symmetry.Grain size distribu...followed by sintering-annealing treatments to form the bulk-phase.X-ray diffraction analysis revealed that all ceramics were crystallized in the orthorhombic perovskite structure with Pbnm symmetry.Grain size distribution and morphological characteri-stics were investigated by scanning electron microscopy.Specific surface area was analyzed through BET-BJH methods.Electrical impedance analysis was investigated as a function of frequency at various temperatures.It was found that the electrical behavior is dominated by grain boundary contribution,i.e.,electrical conductivity.The frequency dependence of the complex conductivity was analyzed through Joncher’s power law and the dominance of translational motion with a sudden hopping mechanism in the electrical conduction mechanism increased with increasing Zn content.Activation energy decreased with increasing Zn content.展开更多
BACKGROUND Malnutrition in cirrhotic patients is correlated with mortality and a better response to liver transplantation.However,recovery of the nutritional status in these patients is a challenge due to the difficul...BACKGROUND Malnutrition in cirrhotic patients is correlated with mortality and a better response to liver transplantation.However,recovery of the nutritional status in these patients is a challenge due to the difficulty in establishing a reliable nutritional diagnosis.The bioelectrical impedance vector analysis(BIVA)method appears as a feasible tool in clinical practice to define the physiological state of cirrhotic patients by assessing hydration and body cellularity.AIM To evaluate body composition in cirrhotic patients using BIVA.METHODS This retrospective cross-sectional study was carried out by following cirrhotic outpatients at a hospital in Porto Alegre,Brazil.A tetrapolar bioelectrical impedance analysis device was used to evaluate cellularity and hydration and to perform the BIVA.The BIVA graphic was elaborated by software and for statistical analysis a significance level of 5%(P≤0.05)was considered.RESULTS One hundred and ninety patients,61.1%males,with a mean age of 56.6±11.0 years,were evaluated.Of these,56.3%had Child-Turcotte-Pugh(CTP)A score,and the prevalent etiology was hepatitis C virus(47.4%).The patients were classified according to cellularity and hydration by the quadrants and ellipses of the BIVA method,quadrant 1(47.9%);quadrant 2(18.9%);quadrant 3(14.2%);and quadrant 4(18.9%).Those classified in quadrant 1 and 2 had a higher phase angle compared to those in quadrants 3 and 4(P<0.001).Quadrant 2 patients had a lower average age than the other groups.The association with CTP score showed that patients in quadrant 2 had a higher proportion of CTP A,and those in quadrant 4 had a higher proportion of CTP C(P<0.052).CONCLUSION The BIVA method allows identification of the cellularity and hydration status of cirrhotic patients,and its association with clinical factors determines the disease severity,age and prognostic index.展开更多
BACKGROUND Morphomics,a computed tomography-based body composition assessment,helps predicting esophageal cancer outcomes,but its link to bioelectrical impedance analysis(BIA)and functional assessments such as hand gr...BACKGROUND Morphomics,a computed tomography-based body composition assessment,helps predicting esophageal cancer outcomes,but its link to bioelectrical impedance analysis(BIA)and functional assessments such as hand grip strength(HGS)and cardiopulmonary exercise testing(CPET)remains unclear.AIM To investigate correlations between morphomics and BIA,HGS,CPET,and assess its ability to predict low cardiorespiratory fitness(CRF).METHODS Fifty esophageal cancer patients underwent multi-level morphomics,BIA,HGS,and CPET.Correlations were analyzed using heatmaps and scatter plots,and logistic regression assessed morphomic predictive value for low CRF.RESULTS T11 is the only level with complete morphomic data,making it the most applicable.To ensure reliability,T11 and its adjacent levels,T10-12,were included in the subsequent analysis.Dorsal muscle group volume from T10-12 morphomics all correlated positively with BIA muscle components(r=0.56-0.68,all P<0.001),HGS(r=0.4-0.48,all P<0.001),and CPET variables(r=0.43-0.51,all P<0.001).Subcutaneous fat area and visceral fat area from morphomics correlated with body fat percentage(r=0.58-0.67,all P<0.001)and negatively with CPET parameters(r=-0.33 to-0.52,all P<0.05).Morphomics also showed potential in identifying low CRF,with an area under the receiver operating characteristic curve of 0.778.CONCLUSION T11 morphomics shows strong correlation with BIA,HGS,and CPET,and may serve as a practical tool for preoperative risk assessment in esophageal cancer patients.展开更多
Objective Bioelectrical impedance analysis(BIA)is used to measure a patient's body composition.The phase angle(PA),the major parameter in BIA,is one of the most sensitive indicators of malnutrition.The aim of the ...Objective Bioelectrical impedance analysis(BIA)is used to measure a patient's body composition.The phase angle(PA),the major parameter in BIA,is one of the most sensitive indicators of malnutrition.The aim of the current study was to investigate whether the PA can be used to predict survival in lung cancer patients.Methods One hundred sixty-six lung cancer patients were prospectively included from January 2014 to August 2016 in Daping Hospital.Anthropometric measurements,hematological values,the nutritional risk screening(NRS 2002)score,patient generated-subjective global assessment(PG-SGA)score,Karnofsky performance status(KPS)scale,European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire(EORTC QLQ C-30)score,and BIA were investigated within 48 hours after admission to the hospital.A Spearman correlation analysis was applied to test the correlations between the study characteristics and PA.A Kaplan-Meier analysis and log-rank test were conducted to analyze the association between the overall survival(OS)and PA.Results The mean age for all patients was 63 years old(42 females and 124 males).The median PA was 5.5°(4.70°,6.23°).The PA was positively associated with the body mass index,hand grip strength,mid-arm circumference,mid-arm muscle circumference,albumin,prealbumin,C-reactive protein,red blood cells,hemoglobin and KPS score.The PG-SGA scores,QLQ-C30 score,and NRS2002 score showed a significant negative association with the PA.According to a multivariate analysis,the PA(HR=0.47;95%CI:0.27-0.81)was independent predictor of the lung cancer patients'long-term OS.Patients with a higher PA(≥5°)had better overall survival(median=426 days)compared to those with a lower PA(<5°)(median=96 days)based on the one-year follow-up data(P<0.0001).Conclusions These studies indicate that the PA is a sensitive and early indicator to predict survival in lung cancer patients.展开更多
To evaluate the relationship between measures of body composition in obese adolescents by the methods of bioelectrical impedance analysis, deuterium oxide dilution and anthropometric measures, proposing an equation. T...To evaluate the relationship between measures of body composition in obese adolescents by the methods of bioelectrical impedance analysis, deuterium oxide dilution and anthropometric measures, proposing an equation. The variables were weight, height, BMI, triceps and subscapular skinfold thickness, waist and arm muscle circumference, lean body mass, fat mass and total body water by bioelectrical impedance and deuterium oxide dilution methods. The study included 40 obese adolescents, 45% male, age distribution was 2.42 ± 1.19 years and females 55%, and the predominant age was 12.61 ± 1.78. Linear regression equations were developed, capable of predicting body composition from information supplied by the method of deuterium oxide dilution (gold standard), bioelectrical impedance and anthropometry. The variables gender, age, height, arm circumference, triceps and suprailiac skin fold thickness, resistance and reactance were used to estimate lean body mass, fat mass and total body water by the method of deuterium and significantly correlated with variables, resistance, reactance, sex and total body water (TBW) by bioimpedance method. Among the equations developed, five were suitable for this sample, therefore, it is suggested that more studies should be done to test the applicability of the equations in other samples so that we can validate the equations encountered in obese adolescents.展开更多
BACKGROUND Nonalcoholic fatty liver disease(NAFLD)includes a spectrum of conditions,progressing from mild steatosis to advanced fibrosis.Sarcopenia,characterized by decreased muscle strength and mass,shares common pat...BACKGROUND Nonalcoholic fatty liver disease(NAFLD)includes a spectrum of conditions,progressing from mild steatosis to advanced fibrosis.Sarcopenia,characterized by decreased muscle strength and mass,shares common pathophysiological traits with NAFLD.An association exists between sarcopenia and increased NAFLD prevalence.However,data on the prevalence of sarcopenia in NAFLD and its impact on the outcomes of NAFLD remain inconsistent.AIM To analyze the prevalence and outcomes of sarcopenia in patients with NAFLD.METHODS We conducted a comprehensive search for relevant studies in MEDLINE,Embase,and Scopus from their inception to June 2023.We included studies that focused on patients with NAFLD,reported the prevalence of sarcopenia as the primary outcome,and examined secondary outcomes,such as liver fibrosis and other adverse events.We also used the Newcastle-Ottawa scale for quality assessment.RESULTS Of the 29 studies included,the prevalence of sarcopenia in NAFLD varied widely(1.6%to 63.0%),with 20 studies reporting a prevalence of more than 10.0%.Substantial heterogeneity was noted in the measurement modalities for sarcopenia.Sarcopenia was associated with a higher risk of advanced fibrosis(odd ratio:1.97,95%confidence interval:1.44-2.70).Increased odds were consistently observed in fibrosis assessment through biopsy,NAFLD fibrosis score/body mass index,aspartate aminotransferase to alanine aminotransferase ratio,diabetes(BARD)score,and transient elastography,whereas the fibrosis-4 score showed no such association.Sarcopenia in NAFLD was associated with a higher risk of steatohepatitis,insulin resistance,cardiovascular risks,and mortality.CONCLUSION This systematic review highlights the critical need for standardized diagnostic criteria and measurement methods for sarcopenia in NAFLD patients.The variability in study designs and assessment methods for sarcopenia and liver fibrosis may account for the inconsistent findings.This review demonstrates the multidimensional impact of sarcopenia on NAFLD,indicating its importance beyond liver-related events to include cardiovascular risks,mortality,and metabolic complications.展开更多
In the current study,the calcium copper titanate(CCTO)/epoxy,barium titanate(BT)/epoxy and CCTO-BT/epoxy composite samples with variable volume fractions of CCTO and BT are fabricated using hand lay-up and compression...In the current study,the calcium copper titanate(CCTO)/epoxy,barium titanate(BT)/epoxy and CCTO-BT/epoxy composite samples with variable volume fractions of CCTO and BT are fabricated using hand lay-up and compression moulding process. The composite samples are characterized for the frequency dependence on dielectric properties,conductivity,impedance spectroscopy and electrical modulus.X-ray diffraction(XRD)representation of CCTO-BT/epoxy composite samples confirmed the presence of both CCTO and BT ceramic samples separately. The dielectric characteristics of hybrid CCTO-BT/epoxy composite samples with CCTO∶BT ratio of 40∶60, 60∶40,and 50∶50 was found relatively better than those of single ceramic filler reinforced epoxy composites. AC conductivity analysis shows improvement in the results of hybrid filler-filled CCTO-BT/epoxy composites in comparison with single filler-filled epoxy composite.50∶50 CCTO-BT/epoxy composite shows the best AC conductivity value of~ 2.2 ×10^(-5) ohm^(-1)·m^(-1) at a higher frequency of 1MHz. The impedance analysis confirms the higher insulating properties for hybrid 40∶60 and 60∶40 CCTO-BT/epoxy composites with respect to the single and other hybrid ceramic epoxy composites. The analysis suggests the hybrid CCTO-BT/epoxy composites to be adopted as a potential dielectric material for energy storage devices and other electronic applications.展开更多
Background: The segmental multi-frequency bioelectrical impedance analysis (SMF-BIA) is a useful method for evaluating physical health and nutritional status in various clinical settings. But less is known about its r...Background: The segmental multi-frequency bioelectrical impedance analysis (SMF-BIA) is a useful method for evaluating physical health and nutritional status in various clinical settings. But less is known about its role in the preoperative assessment of breast cancer patients. Herein, we try to monitor the changes in body composition of preoperative patients by SMF-BIA and figure out its association with clinical features. Methods: The changes in body composition were monitored by SMF-BIA in 563 female patients with breast cancer. Monitor body moisture and collect relevant data on the day before surgery as a prospective study. Retrospective analysis will be conducted based on preoperative data and pathological results after lymph node resection, Spearman’s correlation coefficients were calculated to investigate the correlation among parameters. Results: We found that the body water, extracellular water ratio, and bioelectrical impedance of the affected upper limbs of patients with different tumor stages or different numbers of lymph node metastases were significantly different from those of their healthy upper limbs (P P P P P Conclusion: SMF-BIA can help monitor the changes in body composition of breast cancer patients and provide detailed information for making a personalized treatment plan and individual nursing schedule. However, the value of SMF-BIA in preoperative assessment still needs to be validated in large prospective clinical trials.展开更多
AIM: In patients with liver cirrhosis, hypoalbuminemia causes edema and ascites, and a reduction in the quality of life. Since musculature is catabolized to supply amino acids for albumin synthesis in malnutritional c...AIM: In patients with liver cirrhosis, hypoalbuminemia causes edema and ascites, and a reduction in the quality of life. Since musculature is catabolized to supply amino acids for albumin synthesis in malnutritional cirrhotic patients, muscular volume is hypothesized to play an important role in albumin production. Therefore, we investigated the correlation between serum albumin levels and the fat-free mass (FFM) in cirrhotic patients.METHODS: Fifty-seven patients (26 males and 31 females)with compensated liver cirrhosis were evaluated. Patients with edema or ascites were excluded from the study.Healthy volunteers (n = 104; 48 males and 56 females)were also evaluated as controls. FFM was measured using 5-500 kHz multifrequency bioelectric impedance analysis.To minimize the difference in FFM distribution between males and females, we introduced a new marker, relative FFM (rFFM), which represents the ratio of FFM in a patient relative to that in a volunteer of the same height. Following FFM measurement, the serum albumin levels of patients were assayed monthly.RESULTS: In patients with active cirrhosis (alanine aminotransaminase [ALT] ＞50 U/L), both albumin (the difference between maximum and minimum levels) and the standard deviation of albumin levels (SD-albumin) during the observation period showed a significant correlation with rFFM. Multiple linear regression analysis using variables such as rFFM, platelet number, and serum cholesterol levels,choline esterase, albumin, bilirubin, and ALT revealed that rFFM and ALT were significant and independent factors that influenced albumin or SD-albumin in cirrhotic patients.CONCLUSION: Our results indicate that cirrhotic patients with high rFFM showed less of a decrease in albumin levels, and that the muscle volume is one of the most important factors for maintaining serum albumins level in active cirrhosis. Exercise and protein-rich nutrition at the early stage of liver cirrhosis may be advisable for maintaining or increasing muscular volume.展开更多
We report for the first time a cleavage phenomenon in the resonant peak of a piezoelectric quartz crystal(PQC) in liquid phase.In the presence of a strong longitudinal wave effect,an additional resonant peak appears i...We report for the first time a cleavage phenomenon in the resonant peak of a piezoelectric quartz crystal(PQC) in liquid phase.In the presence of a strong longitudinal wave effect,an additional resonant peak appears in the conductance-frequency curve.With gradually increasing liquid density,the additional peak moves from low to high frequency region then disappears.The frequency of the additional resonant peak is sensitive to the change in liquid density.The frequency shift of the additional peak is linear with the liquid density in a given range.For a 5 MHz PQC with a reflection distance of 16 mm for longitudinal wave,the sensitivity to liquid density is 2.61×10^6 Hz g^-1 cm^3.The overlap between the primary resonant peak and the additional resonant peak causes a decrease in the intensity of the former and an increase in the intensity of the latter.In a combined impedance analysis method,the changes in surface mass loading,density and viscosity of the liquid were monitored simultaneously by a PQC sensor.展开更多
Objective This study aimed to assess the relationship between the body composition of children aged 3–5 years and breastfeeding status and duration.Methods The study was conducted using data from the National Nutriti...Objective This study aimed to assess the relationship between the body composition of children aged 3–5 years and breastfeeding status and duration.Methods The study was conducted using data from the National Nutrition and Health Systematic Survey for children 0–17 years of age in China(CNHSC),a nationwide cross-sectional study.Breastfeeding information and potential confounders were collected using standardized questionnaires administered through face-to-face interviews.The body composition of preschool children was measured using bioelectrical impedance analysis.A multivariate linear regression model was used to assess the relationship between breastfeeding duration and body composition after adjusting for potential confounders.Results In total,2,008 participants were included in the study.Of these,89.2%were ever breastfed and the median duration of breastfeeding was 12 months(IQR 7–15 months).Among children aged 3 years,the height-for-age Z-score(HAZ)for the ever breastfed group was lower than that for never breastfed group(0.12 vs.0.42,P=0.043).In addition,the weight-for-age Z-score(WAZ)of the ever breastfed group was lower than that of the never breastfed group(0.31 vs.0.65,P=0.026),and the WAZ was lower in children aged 4 years who breastfed between 12 and 23 months than in those who never breastfed.Compared to the formula-fed children,the fat-free mass of breastfed infants was higher for children aged 3 years(12.84 kg vs.12.52 kg,P=0.015)and lower for those aged 4 years(14.31 kg vs.14.64 kg,P=0.048),but no difference was detected for children aged 5 years(16.40 kg vs.16.42 kg,P=0.910)after adjusting for potential confounders.No significant difference was detected in the weight-for-height Z-score(WHZ),body mass index(BMI)-for-age Z-score(BAZ),fat-free mass index,and body fat indicators in the ever breastfed and never breastfed groups and among various breastfeeding duration groups for children aged 3–5 years.Conclusion No obvious associations were detected between breastfeeding duration,BMI,and fat mass indicators.Future prospective studies should explore the relationship between breastfeeding status and fat-free mass.展开更多
Background Malnutrition is common in colorectal cancer(CRC)patients,especially in elderly patients.The Patient-Generated Subjective Global Assessment(PG-SGA)is a widely used tool developed to detect malnutrition.The a...Background Malnutrition is common in colorectal cancer(CRC)patients,especially in elderly patients.The Patient-Generated Subjective Global Assessment(PG-SGA)is a widely used tool developed to detect malnutrition.The aim of this study was to compare the value of the PG-SGA and objective nutrition assessment parameters,in order to identify a better predictive index for malnutrition in elderly patients with CRC.Methods A total of 131 elderly patients(age≥60 years)with CRC were included and were evaluated for their individual nutritional status using the PG-SGA.Anthropometric and serological indicators were also assayed within 48 h of admission to the hospital.Body composition analysis was implemented by bioelectrical impedance analysis(BIA)instrument.The Chi-squared test,univariate and multivariate logistic regression analysis,or Spearman’s rank correlation analysis were used to determine the differences among the above indices and parameters with regard to predicting malnutrition.Results According to the PG-SGA score,the incidence of total malnutrition in elderly patients with CRC was 80.92%(PG-SGA score≥2),which increased with age.It was found that 28%of the patients with PG-SGA classification A(PG-SGA score 0-1)had a low fat-free mass index(FFMI).Compared with those with PG-SGA A,patients with PG-SGA C PG-SGA score≥9)showed an increased neutrophil to lymphocyte ratio(NLR)and an increased platelet and lymphocyte ratio(PLR)(median=1.78 VS.2.35,P=0.015 and median=108.8 VS.141.6,P=0.001,respectively).In terms of objective nutrition assessment parameters,severely malnourished CRC patients had significantly lower values of serum albumin(ALB),and retinol conjugated protein(RBP)than those who were well-nourished[(38.35±4.84)g/L VS.(40.56±3.44)g/L,P=0.039 and(30.31±15.83)mg/L VS.(39.01±11.95)mg/L,P=0.033,respectively].The Spearman’s rank correlation analysis showed that the PG-SGA findings had positive correlations with the NLR and PLR;while it had negative correlations with the FFMI,body mass index(BMI),ALB,prealbumin,and RBP.Conclusions In clinical practice,a comprehensive nutritional diagnosis,including the PG-SGA score and these objective indicators,can avoid the underdiagnosis of malnutrition,and is more suitable to detect malnutrition(as well as its causes)in elderly patients with CRC.展开更多
Background The phase angle(PA)is an indicator of nutritional status derived from bioelectrical impedance analysis(BIA).Studies have shown that the PA is one of several factors related to the survival of cancer patient...Background The phase angle(PA)is an indicator of nutritional status derived from bioelectrical impedance analysis(BIA).Studies have shown that the PA is one of several factors related to the survival of cancer patients.However,the correlation between the PA and prognosis in patients with hepatocellular carcinoma(HCC)has not been reported.This study aimed to explore the relationship between the PA,nutrition-related indicators,and patient prognosis.Methods The data from 248 HCC patients who underwent BIA between January 2015 and December 2019 at the First Hospital of Jilin University were retrospectively analyzed.Patients were divided into two groups according to the median PA value,then the nutrition-related indicators and overall survival(OS)were compared between the two groups.The correlations between the PA and laboratory test nutrition-related indicators and the results of a body composition analysis were determined using Pearson correlation analysis.Independent predictors of the patient prognosis were identified using univariate and multivariate analyses.Results The median OS in the high and low PA groups were 70 and 54.6 months,respectively(P=0.004).The Pearson correlation analysis revealed that the PA was associated with both laboratory test nutrition-related indicators and the results of a body composition analysis.The multivariable Cox regression analysis identified the PA as an independent risk factor affecting the prognosis of patients with Barcelona Clinic Liver Cancer stage A or B.Conclusion The PA is a good biomarker for the nutritional status.We found that the PA was associated with the prognosis in patients with HCC,with a low PA indicating a poor nutritional status and worse prognosis.展开更多
The annealing condition, AI content, and field amplitude dependences of the complex permeability for Nb-poor Finemet type alloys, Fe73.5Si13.5B9Cu1Nba-xAlx （x = 0, 0.5, 1.5, 2.0, and 3.0）, were investigated using an...The annealing condition, AI content, and field amplitude dependences of the complex permeability for Nb-poor Finemet type alloys, Fe73.5Si13.5B9Cu1Nba-xAlx （x = 0, 0.5, 1.5, 2.0, and 3.0）, were investigated using an impedance analyzer and X-ray diffraction. The results show that different AI contents lead to different optimum annealing conditions, and the A1 content exerts a distinct effect on microstructure thus resulting in a variety of real permeability value. For the samples annealed at 793 K for 0.5 h, the real permeability increases with an increase in A1 content when the AI content is below 2.0 at.%; as for those annealed at 793 K for 1 h and at 813 K for 0.5 h, an overall increase in real permeability can be obtained compared to those annealed at 793 K for 0.5 h. The permeability under different field amplitudes is also studied and it is found that the relaxation frequency in the lower frequency region tends to moving toward a higher frequency with an increase in field amplitude. All these might be because of the role of Nb in the annealing process and the solubility of AI in the amorphous matrix and nanocrystallized crystallites.展开更多
基金Supported by The Fundacao de Amparo a Pesquisa do Estado de Sao Paulo,Nos.2011/13243-3,2012/15677-3[GB]
文摘AIM To evaluate the prognostic value of the phase angle(PA)obtained from bioelectrical impedance analysis(BIA)for mortality prediction in patients with cirrhosis.METHODS In total,134 male cirrhotic patients prospectively completed clinical evaluations and nutritional assessment by BIA to obtain PAs during a 36-mo follow-up period.Mortality risk was analyzed by applying the PA cutoff point recently proposed as a malnutrition marker(PA≤4.9°)in Kaplan-Meier curves and multivariate Cox regression models.RESULTS The patients were divided into two groups according to the PA cutoff value(PA>4.9°,n=73;PA≤4.9°,n=61).Weight,height,and body mass index were similar in both groups,but patients with PAs>4.9°were younger and had higher mid-arm muscle circumference,albumin,and handgrip-strength values and lower severe ascites and encephalopathy incidences,interleukin(IL)-6/IL-10 ratios and C-reactive protein levels than did patients with PAs≤4.9°(P≤0.05).Forty-eight(35.80%)patients died due to cirrhosis,with a median of 18 mo(interquartile range,3.3-25.6 mo)follow-up until death.Thirty-one(64.60%)of these patients were from the PA≤4.9°group.PA≤4.9°significantly and independently affected the mortality model adjusted for Model for End-Stage Liver Disease score and age(hazard ratio=2.05,95%CI:1.11-3.77,P=0.021).In addition,Kaplan-Meier curves showed that patients with PAs≤4.9°were significantly more likely to die.CONCLUSION In male patients with cirrhosis,the PA≤4.9°cutoff was associated independently with mortality and identified patients with worse metabolic,nutritional,and disease progression profiles.The PA may be a useful and reliable bedside tool to evaluate prognosis in cirrhosis.
基金supported by grants from the National Natural Science Foundation of China(81770532,WDD)the Jiangsu Province Medical Foundation for Youth Talents(QNRC2016901,WDD)。
文摘Background:Fluid overload(FO)after resuscitation is frequent and contributes to adverse outcomes among postinjury open abdomen(OA)patients.Bioelectrical impedance analysis(BIA)is a promising tool for monitoring fluid status and FO.Therefore,we sought to investigate the efficacy of BIA-directed fluid resuscitation among OA patients.Methods:A pragmatic,prospective,randomized,observer-blind,single-center trial was performed for all trauma patients requiring OA between January 2013 and December 2017 to a national referral center.A total of 140 postinjury OA patients were randomly assigned in a 1:1 ratio to receive either a BIA-directed fluid resuscitation(defined as BIA)protocol that included fluid administration with monitoring of hemodynamic parameters and different degrees of interventions to achieve a negative fluid balance targeting the hydration level(HL)measured by BIA or a traditional fluid resuscitation(TRD)in which clinicians determined the fluid resuscitation regimen according to traditional parameters during 30 d of intensive care unit(ICU)management.The primary outcome was the 30-day primary fascial closure(PFC)rate.The secondary outcomes included the time to PFC,postoperative 7-day cumulative fluid balance(CFB)and adverse events within 30 d after OA.The Kaplan–Meier method and the log-rank test were utilized for PFC after OA.A generalized linear regression model for the time to PFC and CFB was built.Results:A total of 134 patients completed the trial(BIA,n=66;TRD,n=68).The BIA patients were significantly more likely to achieve PFC than the TRD patients(83.33%vs.55.88%,P<0.001).In the BIA group,the time to PFC occurred earlier than that of the TRD group by an average of 3.66 d(P<0.001).Additionally,the BIA group showed a lower postoperative 7-day CFB by an average of 6632.80 ml(P<0.001)and fewer complications.Conclusions:Among postinjury OA patients in the ICU,the use of BIA-guided fluid resuscitation resulted in a higher PFC rate and fewer severe complications than the traditional fluid resuscitation strategy.
基金Project supported by the National Natural Science Foundation of China(No.50608036)Program for New Century Excellent Talents in Universities.
文摘An alternative technique for crack detection in a Timoshenko beam based on the first anti-resonant frequency is presented in this paper. Unlike the natural frequency, the anti-resonant frequency is a local parameter rather than a global parameter of structures, thus the proposed technique can be used to locate the structural defects. An impedance analysis of a cracked beam stimulated by a harmonic force based on the Timoshenko beam formulation is investigated. In order to characterize the local discontinuity due to cracks, a rotational spring model based on fracture mechanics is proposed to model the crack. Subsequently, the proposed method is verified by a numerical example of a simply-supported beam with a crack. The effect of the crack size on the anti-resonant frequency is investigated. The position of the crack of the simply-supported beam is also determined by the anti-resonance technique. The proposed technique is further applied to the ＂contaminated＂ anti-resonant frequency to detect crack damage, which is obtained by adding 1-3% noise to the calculated data. It is found that the proposed technique is effective and free from the environment noise. Finally, an experimental study is performed, which further verifies the validity of the proposed crack identification technique.
文摘Simultaneous impedance analysis of three one-face sealed resonating piezoelectric quartz crystals (PQCs) in parallel is proposed through admittance measurements of the three PQCs on one impedance analyzer and then non-linear fitting according to the parallel combination of three Butterworth-Van Dyke circuits. Responses of each PQC obtained from the three-PQC mode agreed well with those measured separately in series sucrose aqueous solutions. This novel method has been used for the study of depletion-layer effect during ferri-/ferrocyanide electrochemical reactions.
基金National Natural Science Foundation of China(52307127)State Key Laboratory of Power System Operation and Control(SKLD23KZ07)。
文摘To facilitate rapid analysis of the oscillation stability mechanism in modular multilevel converter-based high voltage direct current(MMC-HVDC)systems and streamline the simulation process for determining MMC impedance characteristics,a simplified mathematical simulation model for MMC closed-loop impedance is developed using the harmonic state space method.This model considers various control strategies and includes both AC-side and DC-side impedance models.By applying a Nyquist criterion-based impedance analysis method,the stability mechanisms on the AC and DC sides of the MMC are examined.In addition,a data-driven oscillation stability analysis method is also proposed,leveraging a global sensitivity algorithm based on fast model results to identify key parameters influencing MMC oscillation stability.Based on sensitivity analysis results,a parameter adjustment strategy for oscillation suppression is proposed.The simulation results from the MATLAB/Simulinkbased MMC model validate the effectiveness of the proposed method.
基金supported by the National Natural Science Foundation of China under Grant 52277072.
文摘Wide-band oscillations have become a significant issue limiting the development of wind power.Both large-signal and small-signal analyses require extensive model derivation.Moreover,the large number and high order of wind turbines have driven the development of simplified models,whose applicability remains controversial.In this paper,a wide-band oscillation analysis method based on the average-value model(AVM)is proposed for wind farms(WFs).A novel linearization analysis framework is developed,leveraging the continuous-time characteristics of the AVM and MATLAB/Simulink’s built-in linearization tools.This significantly reduces modeling complexity and computational costs while maintaining model fidelity.Additionally,an object-based initial value estimation method of state variables is introduced,which,when combined with steady-state point-solving tools,greatly reduces the computational effort required for equilibrium point solving in batch linearization analysis.The proposed method is validated in both doubly fed induction generator(DFIG)-based and permanent magnet synchronous generator(PMSG)-based WFs.Furthermore,a comprehensive analysis is conducted for the first time to examine the impact of the machine-side system on the system stability of the nonfully controlled PMSG-based WF.
基金Ministry of Research and Technology/National Research and Innovation Agency of Indonesia under PDUPT Grant Number NKB-207/UN2.RST/HKP.05.00/2020.
文摘followed by sintering-annealing treatments to form the bulk-phase.X-ray diffraction analysis revealed that all ceramics were crystallized in the orthorhombic perovskite structure with Pbnm symmetry.Grain size distribution and morphological characteri-stics were investigated by scanning electron microscopy.Specific surface area was analyzed through BET-BJH methods.Electrical impedance analysis was investigated as a function of frequency at various temperatures.It was found that the electrical behavior is dominated by grain boundary contribution,i.e.,electrical conductivity.The frequency dependence of the complex conductivity was analyzed through Joncher’s power law and the dominance of translational motion with a sudden hopping mechanism in the electrical conduction mechanism increased with increasing Zn content.Activation energy decreased with increasing Zn content.
文摘BACKGROUND Malnutrition in cirrhotic patients is correlated with mortality and a better response to liver transplantation.However,recovery of the nutritional status in these patients is a challenge due to the difficulty in establishing a reliable nutritional diagnosis.The bioelectrical impedance vector analysis(BIVA)method appears as a feasible tool in clinical practice to define the physiological state of cirrhotic patients by assessing hydration and body cellularity.AIM To evaluate body composition in cirrhotic patients using BIVA.METHODS This retrospective cross-sectional study was carried out by following cirrhotic outpatients at a hospital in Porto Alegre,Brazil.A tetrapolar bioelectrical impedance analysis device was used to evaluate cellularity and hydration and to perform the BIVA.The BIVA graphic was elaborated by software and for statistical analysis a significance level of 5%(P≤0.05)was considered.RESULTS One hundred and ninety patients,61.1%males,with a mean age of 56.6±11.0 years,were evaluated.Of these,56.3%had Child-Turcotte-Pugh(CTP)A score,and the prevalent etiology was hepatitis C virus(47.4%).The patients were classified according to cellularity and hydration by the quadrants and ellipses of the BIVA method,quadrant 1(47.9%);quadrant 2(18.9%);quadrant 3(14.2%);and quadrant 4(18.9%).Those classified in quadrant 1 and 2 had a higher phase angle compared to those in quadrants 3 and 4(P<0.001).Quadrant 2 patients had a lower average age than the other groups.The association with CTP score showed that patients in quadrant 2 had a higher proportion of CTP A,and those in quadrant 4 had a higher proportion of CTP C(P<0.052).CONCLUSION The BIVA method allows identification of the cellularity and hydration status of cirrhotic patients,and its association with clinical factors determines the disease severity,age and prognostic index.
基金Supported by Chang Gung Memorial Hospital,Taiwan,No.CMRPG3N1171,No.CMRPG3N1172,No.CORPVVN0071,No.CMRPVVK0111-3 and No.CMRPVVL0121-3National Science and Technology Council,Taiwan,No.MOST 114-2314-B-182A-066-.
文摘BACKGROUND Morphomics,a computed tomography-based body composition assessment,helps predicting esophageal cancer outcomes,but its link to bioelectrical impedance analysis(BIA)and functional assessments such as hand grip strength(HGS)and cardiopulmonary exercise testing(CPET)remains unclear.AIM To investigate correlations between morphomics and BIA,HGS,CPET,and assess its ability to predict low cardiorespiratory fitness(CRF).METHODS Fifty esophageal cancer patients underwent multi-level morphomics,BIA,HGS,and CPET.Correlations were analyzed using heatmaps and scatter plots,and logistic regression assessed morphomic predictive value for low CRF.RESULTS T11 is the only level with complete morphomic data,making it the most applicable.To ensure reliability,T11 and its adjacent levels,T10-12,were included in the subsequent analysis.Dorsal muscle group volume from T10-12 morphomics all correlated positively with BIA muscle components(r=0.56-0.68,all P<0.001),HGS(r=0.4-0.48,all P<0.001),and CPET variables(r=0.43-0.51,all P<0.001).Subcutaneous fat area and visceral fat area from morphomics correlated with body fat percentage(r=0.58-0.67,all P<0.001)and negatively with CPET parameters(r=-0.33 to-0.52,all P<0.05).Morphomics also showed potential in identifying low CRF,with an area under the receiver operating characteristic curve of 0.778.CONCLUSION T11 morphomics shows strong correlation with BIA,HGS,and CPET,and may serve as a practical tool for preoperative risk assessment in esophageal cancer patients.
基金supported by the National Natural Science Foundation of China(No:81673167 to Hongxia Xu)the Chongqing Technology Innovation and Application Dem on stration Project for Social Livelihood(cstc2018jscx-msybX0094,to Jie Liu).
文摘Objective Bioelectrical impedance analysis(BIA)is used to measure a patient's body composition.The phase angle(PA),the major parameter in BIA,is one of the most sensitive indicators of malnutrition.The aim of the current study was to investigate whether the PA can be used to predict survival in lung cancer patients.Methods One hundred sixty-six lung cancer patients were prospectively included from January 2014 to August 2016 in Daping Hospital.Anthropometric measurements,hematological values,the nutritional risk screening(NRS 2002)score,patient generated-subjective global assessment(PG-SGA)score,Karnofsky performance status(KPS)scale,European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire(EORTC QLQ C-30)score,and BIA were investigated within 48 hours after admission to the hospital.A Spearman correlation analysis was applied to test the correlations between the study characteristics and PA.A Kaplan-Meier analysis and log-rank test were conducted to analyze the association between the overall survival(OS)and PA.Results The mean age for all patients was 63 years old(42 females and 124 males).The median PA was 5.5°(4.70°,6.23°).The PA was positively associated with the body mass index,hand grip strength,mid-arm circumference,mid-arm muscle circumference,albumin,prealbumin,C-reactive protein,red blood cells,hemoglobin and KPS score.The PG-SGA scores,QLQ-C30 score,and NRS2002 score showed a significant negative association with the PA.According to a multivariate analysis,the PA(HR=0.47;95%CI:0.27-0.81)was independent predictor of the lung cancer patients'long-term OS.Patients with a higher PA(≥5°)had better overall survival(median=426 days)compared to those with a lower PA(<5°)(median=96 days)based on the one-year follow-up data(P<0.0001).Conclusions These studies indicate that the PA is a sensitive and early indicator to predict survival in lung cancer patients.
文摘To evaluate the relationship between measures of body composition in obese adolescents by the methods of bioelectrical impedance analysis, deuterium oxide dilution and anthropometric measures, proposing an equation. The variables were weight, height, BMI, triceps and subscapular skinfold thickness, waist and arm muscle circumference, lean body mass, fat mass and total body water by bioelectrical impedance and deuterium oxide dilution methods. The study included 40 obese adolescents, 45% male, age distribution was 2.42 ± 1.19 years and females 55%, and the predominant age was 12.61 ± 1.78. Linear regression equations were developed, capable of predicting body composition from information supplied by the method of deuterium oxide dilution (gold standard), bioelectrical impedance and anthropometry. The variables gender, age, height, arm circumference, triceps and suprailiac skin fold thickness, resistance and reactance were used to estimate lean body mass, fat mass and total body water by the method of deuterium and significantly correlated with variables, resistance, reactance, sex and total body water (TBW) by bioimpedance method. Among the equations developed, five were suitable for this sample, therefore, it is suggested that more studies should be done to test the applicability of the equations in other samples so that we can validate the equations encountered in obese adolescents.
文摘BACKGROUND Nonalcoholic fatty liver disease(NAFLD)includes a spectrum of conditions,progressing from mild steatosis to advanced fibrosis.Sarcopenia,characterized by decreased muscle strength and mass,shares common pathophysiological traits with NAFLD.An association exists between sarcopenia and increased NAFLD prevalence.However,data on the prevalence of sarcopenia in NAFLD and its impact on the outcomes of NAFLD remain inconsistent.AIM To analyze the prevalence and outcomes of sarcopenia in patients with NAFLD.METHODS We conducted a comprehensive search for relevant studies in MEDLINE,Embase,and Scopus from their inception to June 2023.We included studies that focused on patients with NAFLD,reported the prevalence of sarcopenia as the primary outcome,and examined secondary outcomes,such as liver fibrosis and other adverse events.We also used the Newcastle-Ottawa scale for quality assessment.RESULTS Of the 29 studies included,the prevalence of sarcopenia in NAFLD varied widely(1.6%to 63.0%),with 20 studies reporting a prevalence of more than 10.0%.Substantial heterogeneity was noted in the measurement modalities for sarcopenia.Sarcopenia was associated with a higher risk of advanced fibrosis(odd ratio:1.97,95%confidence interval:1.44-2.70).Increased odds were consistently observed in fibrosis assessment through biopsy,NAFLD fibrosis score/body mass index,aspartate aminotransferase to alanine aminotransferase ratio,diabetes(BARD)score,and transient elastography,whereas the fibrosis-4 score showed no such association.Sarcopenia in NAFLD was associated with a higher risk of steatohepatitis,insulin resistance,cardiovascular risks,and mortality.CONCLUSION This systematic review highlights the critical need for standardized diagnostic criteria and measurement methods for sarcopenia in NAFLD patients.The variability in study designs and assessment methods for sarcopenia and liver fibrosis may account for the inconsistent findings.This review demonstrates the multidimensional impact of sarcopenia on NAFLD,indicating its importance beyond liver-related events to include cardiovascular risks,mortality,and metabolic complications.
文摘In the current study,the calcium copper titanate(CCTO)/epoxy,barium titanate(BT)/epoxy and CCTO-BT/epoxy composite samples with variable volume fractions of CCTO and BT are fabricated using hand lay-up and compression moulding process. The composite samples are characterized for the frequency dependence on dielectric properties,conductivity,impedance spectroscopy and electrical modulus.X-ray diffraction(XRD)representation of CCTO-BT/epoxy composite samples confirmed the presence of both CCTO and BT ceramic samples separately. The dielectric characteristics of hybrid CCTO-BT/epoxy composite samples with CCTO∶BT ratio of 40∶60, 60∶40,and 50∶50 was found relatively better than those of single ceramic filler reinforced epoxy composites. AC conductivity analysis shows improvement in the results of hybrid filler-filled CCTO-BT/epoxy composites in comparison with single filler-filled epoxy composite.50∶50 CCTO-BT/epoxy composite shows the best AC conductivity value of~ 2.2 ×10^(-5) ohm^(-1)·m^(-1) at a higher frequency of 1MHz. The impedance analysis confirms the higher insulating properties for hybrid 40∶60 and 60∶40 CCTO-BT/epoxy composites with respect to the single and other hybrid ceramic epoxy composites. The analysis suggests the hybrid CCTO-BT/epoxy composites to be adopted as a potential dielectric material for energy storage devices and other electronic applications.
文摘Background: The segmental multi-frequency bioelectrical impedance analysis (SMF-BIA) is a useful method for evaluating physical health and nutritional status in various clinical settings. But less is known about its role in the preoperative assessment of breast cancer patients. Herein, we try to monitor the changes in body composition of preoperative patients by SMF-BIA and figure out its association with clinical features. Methods: The changes in body composition were monitored by SMF-BIA in 563 female patients with breast cancer. Monitor body moisture and collect relevant data on the day before surgery as a prospective study. Retrospective analysis will be conducted based on preoperative data and pathological results after lymph node resection, Spearman’s correlation coefficients were calculated to investigate the correlation among parameters. Results: We found that the body water, extracellular water ratio, and bioelectrical impedance of the affected upper limbs of patients with different tumor stages or different numbers of lymph node metastases were significantly different from those of their healthy upper limbs (P P P P P Conclusion: SMF-BIA can help monitor the changes in body composition of breast cancer patients and provide detailed information for making a personalized treatment plan and individual nursing schedule. However, the value of SMF-BIA in preoperative assessment still needs to be validated in large prospective clinical trials.
文摘AIM: In patients with liver cirrhosis, hypoalbuminemia causes edema and ascites, and a reduction in the quality of life. Since musculature is catabolized to supply amino acids for albumin synthesis in malnutritional cirrhotic patients, muscular volume is hypothesized to play an important role in albumin production. Therefore, we investigated the correlation between serum albumin levels and the fat-free mass (FFM) in cirrhotic patients.METHODS: Fifty-seven patients (26 males and 31 females)with compensated liver cirrhosis were evaluated. Patients with edema or ascites were excluded from the study.Healthy volunteers (n = 104; 48 males and 56 females)were also evaluated as controls. FFM was measured using 5-500 kHz multifrequency bioelectric impedance analysis.To minimize the difference in FFM distribution between males and females, we introduced a new marker, relative FFM (rFFM), which represents the ratio of FFM in a patient relative to that in a volunteer of the same height. Following FFM measurement, the serum albumin levels of patients were assayed monthly.RESULTS: In patients with active cirrhosis (alanine aminotransaminase [ALT] ＞50 U/L), both albumin (the difference between maximum and minimum levels) and the standard deviation of albumin levels (SD-albumin) during the observation period showed a significant correlation with rFFM. Multiple linear regression analysis using variables such as rFFM, platelet number, and serum cholesterol levels,choline esterase, albumin, bilirubin, and ALT revealed that rFFM and ALT were significant and independent factors that influenced albumin or SD-albumin in cirrhotic patients.CONCLUSION: Our results indicate that cirrhotic patients with high rFFM showed less of a decrease in albumin levels, and that the muscle volume is one of the most important factors for maintaining serum albumins level in active cirrhosis. Exercise and protein-rich nutrition at the early stage of liver cirrhosis may be advisable for maintaining or increasing muscular volume.
基金supported by the National Natural Science Foundation of China(Nos.20775045,20975063)open foundation of the State Key Laboratory of Chemo/Biosensing and Chemometrics,Hunan University(No.2008012)
文摘We report for the first time a cleavage phenomenon in the resonant peak of a piezoelectric quartz crystal(PQC) in liquid phase.In the presence of a strong longitudinal wave effect,an additional resonant peak appears in the conductance-frequency curve.With gradually increasing liquid density,the additional peak moves from low to high frequency region then disappears.The frequency of the additional resonant peak is sensitive to the change in liquid density.The frequency shift of the additional peak is linear with the liquid density in a given range.For a 5 MHz PQC with a reflection distance of 16 mm for longitudinal wave,the sensitivity to liquid density is 2.61×10^6 Hz g^-1 cm^3.The overlap between the primary resonant peak and the additional resonant peak causes a decrease in the intensity of the former and an increase in the intensity of the latter.In a combined impedance analysis method,the changes in surface mass loading,density and viscosity of the liquid were monitored simultaneously by a PQC sensor.
基金supported by National Special Program for Science&Technology Basic Resources Investigation of China[Grant Number:2017FY101100 and 2017FY101103]。
文摘Objective This study aimed to assess the relationship between the body composition of children aged 3–5 years and breastfeeding status and duration.Methods The study was conducted using data from the National Nutrition and Health Systematic Survey for children 0–17 years of age in China(CNHSC),a nationwide cross-sectional study.Breastfeeding information and potential confounders were collected using standardized questionnaires administered through face-to-face interviews.The body composition of preschool children was measured using bioelectrical impedance analysis.A multivariate linear regression model was used to assess the relationship between breastfeeding duration and body composition after adjusting for potential confounders.Results In total,2,008 participants were included in the study.Of these,89.2%were ever breastfed and the median duration of breastfeeding was 12 months(IQR 7–15 months).Among children aged 3 years,the height-for-age Z-score(HAZ)for the ever breastfed group was lower than that for never breastfed group(0.12 vs.0.42,P=0.043).In addition,the weight-for-age Z-score(WAZ)of the ever breastfed group was lower than that of the never breastfed group(0.31 vs.0.65,P=0.026),and the WAZ was lower in children aged 4 years who breastfed between 12 and 23 months than in those who never breastfed.Compared to the formula-fed children,the fat-free mass of breastfed infants was higher for children aged 3 years(12.84 kg vs.12.52 kg,P=0.015)and lower for those aged 4 years(14.31 kg vs.14.64 kg,P=0.048),but no difference was detected for children aged 5 years(16.40 kg vs.16.42 kg,P=0.910)after adjusting for potential confounders.No significant difference was detected in the weight-for-height Z-score(WHZ),body mass index(BMI)-for-age Z-score(BAZ),fat-free mass index,and body fat indicators in the ever breastfed and never breastfed groups and among various breastfeeding duration groups for children aged 3–5 years.Conclusion No obvious associations were detected between breastfeeding duration,BMI,and fat mass indicators.Future prospective studies should explore the relationship between breastfeeding status and fat-free mass.
基金the Project of Health and Family Planning Commission of Jilin Province(Grant 2017J064 to JW.C)the Project of Jilin Provincial Department of Education(Grant JJKH20190020KJ to JW.C)。
文摘Background Malnutrition is common in colorectal cancer(CRC)patients,especially in elderly patients.The Patient-Generated Subjective Global Assessment(PG-SGA)is a widely used tool developed to detect malnutrition.The aim of this study was to compare the value of the PG-SGA and objective nutrition assessment parameters,in order to identify a better predictive index for malnutrition in elderly patients with CRC.Methods A total of 131 elderly patients(age≥60 years)with CRC were included and were evaluated for their individual nutritional status using the PG-SGA.Anthropometric and serological indicators were also assayed within 48 h of admission to the hospital.Body composition analysis was implemented by bioelectrical impedance analysis(BIA)instrument.The Chi-squared test,univariate and multivariate logistic regression analysis,or Spearman’s rank correlation analysis were used to determine the differences among the above indices and parameters with regard to predicting malnutrition.Results According to the PG-SGA score,the incidence of total malnutrition in elderly patients with CRC was 80.92%(PG-SGA score≥2),which increased with age.It was found that 28%of the patients with PG-SGA classification A(PG-SGA score 0-1)had a low fat-free mass index(FFMI).Compared with those with PG-SGA A,patients with PG-SGA C PG-SGA score≥9)showed an increased neutrophil to lymphocyte ratio(NLR)and an increased platelet and lymphocyte ratio(PLR)(median=1.78 VS.2.35,P=0.015 and median=108.8 VS.141.6,P=0.001,respectively).In terms of objective nutrition assessment parameters,severely malnourished CRC patients had significantly lower values of serum albumin(ALB),and retinol conjugated protein(RBP)than those who were well-nourished[(38.35±4.84)g/L VS.(40.56±3.44)g/L,P=0.039 and(30.31±15.83)mg/L VS.(39.01±11.95)mg/L,P=0.033,respectively].The Spearman’s rank correlation analysis showed that the PG-SGA findings had positive correlations with the NLR and PLR;while it had negative correlations with the FFMI,body mass index(BMI),ALB,prealbumin,and RBP.Conclusions In clinical practice,a comprehensive nutritional diagnosis,including the PG-SGA score and these objective indicators,can avoid the underdiagnosis of malnutrition,and is more suitable to detect malnutrition(as well as its causes)in elderly patients with CRC.
基金Science and Technology Department of Jilin Provincial(No.3D5204167428 for Dr.Nan Ya Wang).
文摘Background The phase angle(PA)is an indicator of nutritional status derived from bioelectrical impedance analysis(BIA).Studies have shown that the PA is one of several factors related to the survival of cancer patients.However,the correlation between the PA and prognosis in patients with hepatocellular carcinoma(HCC)has not been reported.This study aimed to explore the relationship between the PA,nutrition-related indicators,and patient prognosis.Methods The data from 248 HCC patients who underwent BIA between January 2015 and December 2019 at the First Hospital of Jilin University were retrospectively analyzed.Patients were divided into two groups according to the median PA value,then the nutrition-related indicators and overall survival(OS)were compared between the two groups.The correlations between the PA and laboratory test nutrition-related indicators and the results of a body composition analysis were determined using Pearson correlation analysis.Independent predictors of the patient prognosis were identified using univariate and multivariate analyses.Results The median OS in the high and low PA groups were 70 and 54.6 months,respectively(P=0.004).The Pearson correlation analysis revealed that the PA was associated with both laboratory test nutrition-related indicators and the results of a body composition analysis.The multivariable Cox regression analysis identified the PA as an independent risk factor affecting the prognosis of patients with Barcelona Clinic Liver Cancer stage A or B.Conclusion The PA is a good biomarker for the nutritional status.We found that the PA was associated with the prognosis in patients with HCC,with a low PA indicating a poor nutritional status and worse prognosis.
基金the National Basic Research Program of China (No. 2007CB209400) the Science & Technology Fund of China University of Mining & Technology (No. 2005B024)
文摘The annealing condition, AI content, and field amplitude dependences of the complex permeability for Nb-poor Finemet type alloys, Fe73.5Si13.5B9Cu1Nba-xAlx （x = 0, 0.5, 1.5, 2.0, and 3.0）, were investigated using an impedance analyzer and X-ray diffraction. The results show that different AI contents lead to different optimum annealing conditions, and the A1 content exerts a distinct effect on microstructure thus resulting in a variety of real permeability value. For the samples annealed at 793 K for 0.5 h, the real permeability increases with an increase in A1 content when the AI content is below 2.0 at.%; as for those annealed at 793 K for 1 h and at 813 K for 0.5 h, an overall increase in real permeability can be obtained compared to those annealed at 793 K for 0.5 h. The permeability under different field amplitudes is also studied and it is found that the relaxation frequency in the lower frequency region tends to moving toward a higher frequency with an increase in field amplitude. All these might be because of the role of Nb in the annealing process and the solubility of AI in the amorphous matrix and nanocrystallized crystallites.
