Numerical simulation of influence of shear dilatancy on deformation characteristics of shear band-elastic body system

The paper was numerically focused on investigation of deformation, failure and instability of shear band-surrounding elastic rock system in plane strain direct shear test considering shear dilatancy according to fast lagrangian analysis of continua (FLAC). The adopted failure criterion was a composite Mohr-Coulomb criterion with tension cut-off and post-peak constitutive relation of rock, i.e. linear strain-softening. Numerical results show that dilation angle affects the responses of elements, the number and the position of yielded elements. Increasing dilation angle results in higher load-carrying capability of elements, higher deformation or strain corresponding to peak stress, less brittle post-peak stress-deformation curve. Strain-hardening behavior can occur if dilation angle is high. Therefore, shear band-elastic rock body system tends to be stable and rock burst does not occur as dilation angle is increased. Moreover, the number of yielded elements is in- creased with dilation angle increase and two parallel plastic zones initially generated in the middle of two loading ends of specimen no longer remain collinear, reflecting increase in deformation resistant of the system. Evolution of volumetric strain rate was investigated based on three-dimensional curved surface diagrams. Approximately, volumetric strain rate concentration regions coincide with plastic zones. Volumetric strain rate in yielded elements is very evident. However, in elastic zones volumetric strain has not been nearly changed throughout the numerical tests.

Shear stress distribution and characteristics of deformation for shear band-elastic body system at pre-peak and post-peak

The distributed shear stress and the displacement across shear band, the evolution of plastic zones, and the load-carrying capacity of rock specimen were investigated in plane strain direct shear test according to Fast Lagrangian Analysis of Continua （FLAC）. And then the shear displacement distribution in normal direction of system composed of localized shear band and elastic rock was analyzed based on gradient-dependent plasticity. The adopted failure criterion was a composite of Mohr-Coulomb criterion, that is, the relation between tension cut-off and postpeak constitutive of rock was linear strain-softening. Numerical results show that shear stress field approximately undergoes three different stages. At first, shear stress is only concentrated in the middle of top and base of specimen. Next, shear stress in the middle of specimen tends to increase, owing to superposition of shear stresses. Interestingly, two peaks of shear stress appear far from the loading ends of specimen, and the peaks approach with the increase in timestep until elements at the center of specimen yield. Finally, relatively lower shear stress level is reached in large part of specimen except in the regions near the two ends. As flow stress decreases, the analytical shear displacement distribution in shear band based on gradient-dependent plasticity becomes steeps outside the band, it is linear and its slope tends to decrease. These theoretical results qualitatively agree with that of the present numerical predicted results. Main advantage of the analytical solution over the numerical results according to FLAC is that it is continuous, smooth and non-linear （except at elastic stage）.

DYNAMICS OF FLEXIBLE MULTIBODY SYSTEMS WITH TREE TOPOLOGIES

The dynamic equations of flexible multibody systems with tree topological configuration are de- rived by using the Jourdain's principle.The independent joint coordinates are introduced to describe the large displacements of the bodies,and the modal coordinates are used to describe small deformations of flexible bodies based on the consistent mass finite element method and normal vibration mode analysis.The mini- mum differential equations are developed,which are compatible with the equations of multi-rigid body sys- tems or structural dynamics.The stiff problem in the numerical integration is thus alleviated effectively.The method used in this paper can be extended to deal with systems with other topological configurations. Finally,the validity and feasibility of the presented mathematical model are demonstrated by a numerical ex- ample of a manipulator with two elastic links.

The relation between a black hole and a general black body system

Taking a black hole as a black body system, using general black body radiation theory, a Schwarzschild black hole and a Kerr-Newman black hole are investigated respectively. It is concluded that a black hole can be regarded as an ideal general black body system exactly for the changing process only. However, a stationary global black hole cannot be smoothly regarded as a general black body system. A black hole has some special characteristics which different from a general thermodynamics system. This conclusion means that a black hole should be inherently dynamical, at least when it is taken as a black body system.

The Challenges and Opportunities of Buddhist Music Discipline in a New Era-The Practice and Application of Mind and Body System in Chinese Buddhist Chanting

Religious music is an inevitable and important topic when exploring the significance of the“new”or“deep”dimension of religion or spirituality.Traditional Chinese culture influenced Chinese Buddhist chanting practices,developing special melodies,languages,and meaning,and establishing special mind and body practice system spanning thousands of years.Advances in music therapy,meditation,and vocal research give the Chinese Buddhist chanting mind and body practice system enough theoretical support to facilitate the construction of the discipline in the modern era.This paper adopts the scientific approach to tracing and analyzing the origins of the body and mind system in Chinese Buddhist chanting practice and reviews how the system benefits the mind and body and modern society in general.This paper also examines the issues confronting the standard and development of special chanting skills in Chinese Buddhist music in the modern era.

Automated body composition analysis system based on chest CT for evaluating content of muscle and adipose

Objective To establish a body composition analysis system based on chest CT,and to observe its value for evaluating content of chest muscle and adipose.Methods T7—T8 layer CT images of 108 pneumonia patients were collected(segmented dataset),and chest CT data of 984 patients were screened from the COVID 19-CT dataset(10 cases were randomly selected as whole test dataset,the remaining 974 cases were selected as layer selection dataset).T7—T8 layer was classified based on convolutional neural network(CNN)derived networks,including ResNet,ResNeXt,MobileNet,ShuffleNet,DenseNet,EfficientNet and ConvNeXt,then the accuracy,precision,recall and specificity were used to evaluate the performance of layer selection dataset.The skeletal muscle(SM),subcutaneous adipose tissue(SAT),intermuscular adipose tissue(IMAT)and visceral adipose tissue(VAT)were segmented using classical fully CNN(FCN)derived network,including FCN,SegNet,UNet,Attention UNet,UNET++,nnUNet,UNeXt and CMUNeXt,then Dice similarity coefficient(DSC),intersection over union(IoU)and 95 Hausdorff distance(HD)were used to evaluate the performance of segmented dataset.The automatic body composition analysis system was constructed based on optimal layer selection network and segmentation network,the mean absolute error(MAE),root mean squared error(RMSE)and standard deviation(SD)of MAE were used to evaluate the performance of automatic system for testing the whole test dataset.Results The accuracy,precision,recall and specificity of DenseNet network for automatically classifying T7—T8 layer from chest CT images was 95.06%,84.83%,92.27%and 95.78%,respectively,which were all higher than those of the other layer selection networks.In segmentation of SM,SAT,IMAT and overall,DSC and IoU of UNet++network were all higher,while 95HD of UNet++network were all lower than those of the other segmentation networks.Using DenseNet as the layer selection network and UNet++as the segmentation network,MAE of the automatic body composition analysis system for predicting SM,SAT,IMAT,VAT and MAE was 27.09,6.95,6.65 and 3.35 cm 2,respectively.Conclusion The body composition analysis system based on chest CT could be used to assess content of chest muscle and adipose.Among them,the UNet++network had better segmentation performance in adipose tissue than SM.

Impact of body mass index on adverse kidney events in diabetes mellitus patients: A systematic-review and meta-analysis

BACKGROUND The incidence of chronic kidney disease among patients with diabetes mellitus(DM)remains a global concern.Long-term obesity is known to possibly influence the development of type 2 diabetes mellitus.However,no previous meta-analysis has assessed the effects of body mass index(BMI)on adverse kidney events in patients with DM.AIM To determine the impact of BMI on adverse kidney events in patients with DM.METHODS A systematic literature search was performed on the PubMed,ISI Web of Science,Scopus,Ovid,Google Scholar,EMBASE,and BMJ databases.We included trials with the following characteristics:(1)Type of study:Prospective,retrospective,randomized,and non-randomized in design;(2)participants:Restricted to patients with DM aged≥18 years;(3)intervention:No intervention;and(4)kidney adverse events:Onset of diabetic kidney disease[estimated glomerular filtration rate(eGFR)of<60 mL/min/1.73 m2 and/or microalbuminuria value of≥30 mg/g Cr],serum creatinine increase of more than double the baseline or end-stage renal disease(eGFR<15 mL/min/1.73 m2 or dialysis),or death.RESULTS Overall,11 studies involving 801 patients with DM were included.High BMI(≥25 kg/m2)was significantly associated with higher blood pressure(BP)[systolic BP by 0.20,95%confidence interval(CI):0.15–0.25,P<0.00001;diastolic BP by 0.21 mmHg,95%CI:0.04–0.37,P=0.010],serum albumin,triglycerides[standard mean difference(SMD)=0.35,95%CI:0.29–0.41,P<0.00001],low-density lipoprotein(SMD=0.12,95%CI:0.04–0.20,P=0.030),and lower high-density lipoprotein(SMD=–0.36,95%CI:–0.51 to–0.21,P<0.00001)in patients with DM compared with those with low BMIs(<25 kg/m2).Our analysis showed that high BMI was associated with a higher risk ratio of adverse kidney events than low BMI(RR:1.22,95%CI:1.01–1.43,P=0.036).CONCLUSION The present analysis suggested that high BMI was a risk factor for adverse kidney events in patients with DM.

交互式数字叙事:加拿大Writing New Body Worlds阅读治疗新探索

文章基于相关研究文献与语料,对加拿大WNB阅读治疗实践进行梳理与归纳。WNB首次使用交互式数字叙事技术,构建面向公众的阅读治疗平台,以其交互式特征,融合了阅读和治疗引导两个过程,提供可访问的非临床方式,可面向大规模人群实现预防性健康干预。基于数据与计算的精准化阅读治疗是数字人文视角下的新变革,更具推广应用价值;以在线阅读平台建设为依托,推进实施平台化的阅读和治疗应成为未来发展方向之一;基于阅读形态与体验因技术赋能而改变的现状,图书馆应发挥引领作用,积极收集、创建或协助创建数字故事,推进阅读推广、服务与治疗的融合性发展,成为社区建设促进者、历史欣赏者和社区参与倡导者,也使阅读借助交互式数字叙事这一新载体,更好地发挥变革的力量,促进健康与幸福。

Dysregulation of RNA modification systems in clinical populations with neurocognitive disorders

The study of modified RNA known as epitranscriptomics has become increasingly relevant in our understanding of disease-modifying mechanisms.Methylation of N6 adenosine(m^(6)A)and C5 cytosine(m^(5)C)bases occur on mRNAs,tRNA,mt-tRNA,and rRNA species as well as non-coding RNAs.With emerging knowledge of RNA binding proteins that act as writer,reader,and eraser effector proteins,comes a new understanding of physiological processes controlled by these systems.Such processes when spatiotemporally disrupted within cellular nanodomains in highly specialized tissues such as the brain,give rise to different forms of disease.In this review,we discuss accumulating evidence that changes in the m^(6)A and m^(5)C methylation systems contribute to neurocognitive disorders.Early studies first identified mutations within FMR1 to cause intellectual disability Fragile X syndromes several years before FMR1 was identified as an m^(6)A RNA reader protein.Subsequently,familial mutations within the m^(6)A writer gene METTL5,m^(5)C writer genes NSUN2,NSUN3,NSUN5,and NSUN6,as well as THOC2 and THOC6 that form a protein complex with the m^(5)C reader protein ALYREF,were recognized to cause intellectual development disorders.Similarly,differences in expression of the m^(5)C writer and reader effector proteins,NSUN6,NSUN7,and ALYREF in brain tissue are indicated in individuals with Alzheimer's disease,individuals with a high neuropathological load or have suffered traumatic brain injury.Likewise,an abundance of m^(6)A reader and anti-reader proteins are reported to change across brain regions in Lewy bodies diseases,Alzheimer's disease,and individuals with high cognitive reserve.m^(6)A-modified RNAs are also reported significantly more abundant in dementia with Lewy bodies brain tissue but significantly reduced in Parkinson's disease tissue,whilst modified RNAs are misplaced within diseased cells,particularly where synapses are located.In parahippocampal brain tissue,m^(6)A modification is enriched in transcripts associated with psychiatric disorders including conditions with clear cognitive deficits.These findings indicate a diverse set of molecular mechanisms are influenced by RNA methylation systems that can cause neuronal and synaptic dysfunction underlying neurocognitive disorders.Targeting these RNA modification systems brings new prospects for neural regenerative therapies.

3D body解剖软件联合PACS系统在骨科临床实践教学中的应用

目的探讨3D body解剖软件结合医学影像存档与通信系统(PACS)在骨科临床实践教学中的应用效果。方法选择2023年1月至2023年12月在浙江大学医学院附属邵逸夫医院骨科轮转的60名实习生,按照随机数字表法分成实验组和对照组,每组30名。对照组采用传统线上结合线下的混合式教学方法,实验组采用3D body解剖软件联合PACS系统带教模式。在实习期结束时,对两组实习生进行闭卷理论考试与临床实践操作考核,并采用问卷调查方式评估实习生对课程的满意度。结果实验组实习生的理论考试与临床实践操作成绩均高于对照组,差异均有统计学意义(t分别=6.59、4.22,P均<0.05)。实验组实习生在学习兴趣、教学难度、专业能力以及医患沟通能力提升方面的满意度均高于对照组,差异均有统计学意义(χ^(2)分别=9.93、3.77、6.94、8.52,P均<0.05)。结论3D body解剖软件联合PACS系统带教模式运用到骨科实习生的临床教学中,能帮助实习生提高学习兴趣以及医患沟通能力,加强对骨科知识的掌握,降低知识的理解难度,对于提升临床医学教学质量具有重要意义。

Body composition and metabolic syndrome in patients with type 1 diabetes

BACKGROUND In recent years,the prevalence of obesity and metabolic syndrome in type 1 diabetes(T1DM)patients has gradually increased.Insulin resistance in T1DM deserves attention.It is necessary to clarify the relationship between body composition,metabolic syndrome and insulin resistance in T1DM to guide clinical treatment and intervention.AIM To assess body composition(BC)in T1DM patients and evaluate the relationship between BC,metabolic syndrome(MS),and insulin resistance in these indi-viduals.METHODS A total of 101 subjects with T1DM,aged 10 years or older,and with a disease duration of over 1 year were included.Bioelectrical impedance analysis using the Tsinghua-Tongfang BC Analyzer BCA-1B was employed to measure various BC parameters.Clinical and laboratory data were collected,and insulin resistance was calculated using the estimated glucose disposal rate(eGDR).RESULTS MS was diagnosed in 16/101 patients(15.84%),overweight in 16/101 patients(15.84%),obesity in 4/101(3.96%),hypertension in 34/101(33.66%%)and dyslip-idemia in 16/101 patients(15.84%).Visceral fat index(VFI)and trunk fat mass were significantly and negatively correlated with eGDR(both P<0.001).Female patients exhibited higher body fat percentage and visceral fat ratio compared to male patients.Binary logistic regression analysis revealed that significant factors for MS included eGDR[P=0.017,odds ratio(OR)=0.109],VFI(P=0.030,OR=3.529),and a family history of diabetes(P=0.004,OR=0.228).Significant factors for hypertension included eGDR(P<0.001,OR=0.488)and skeletal muscle mass(P=0.003,OR=1.111).Significant factors for dyslipidemia included trunk fat mass(P=0.033,OR=1.202)and eGDR(P=0.037,OR=0.708).CONCLUSION Visceral fat was found to be a superior predictor of MS compared to conventional measures such as body mass index and waist-to-hip ratio in Chinese individuals with T1DM.BC analysis,specifically identifying visceral fat(trunk fat),may play an important role in identifying the increased risk of MS in non-obese patients with T1DM.

Soft,body conformable electronics for thermoregulation enabled by kirigami

The application of thermoelectric devices(TEDs)for personalized thermoregulation is attractive for saving energy while balancing the quality of life.TEDs that directly attach to human skin remarkably minimized the energy wasted for cooling the entire environment.However,facing the extreme dynamic geometry change and strain of human skin,conventional TEDs cannot align with the contour of our bodies for the best thermoregulation effect.Hence,we designed a kirigami-based wearable TED with excellent water vapor permeability,flexibility,and conformability.Numerical analysis and experimental results reveal that our product can withstand various types of large mechanical deformation without circuit rupture.The stated outcome and proposed facile approach not only reinforce the development of wearable TEDs but also offer an innovative opportunity for different electronics that require high conformability.

α-Synuclein pathology from the body to the brain:so many seeds so close to the central soil

α-Synuclein is a protein that mainly exists in the presynaptic terminals.Abnormal folding and accumulation of α-synuclein are found in several neurodegenerative diseases,including Parkinson’s disease.Aggregated and highly phospho rylated a-synuclein constitutes the main component of Lewy bodies in the brain,the pathological hallmark of Parkinson s disease.For decades,much attention has been focused on the accumulation of α-synuclein in the brain parenchyma rather than considering Parkinson s disease as a systemic disease.Recent evidence demonstrates that,at least in some patients,the initial α-synuclein pathology originates in the peripheral organs and spreads to the brain.Injection of α-synuclein preformed fibrils into the gastrointestinal tra ct trigge rs the gutto-brain propagation of α-synuclein pathology.However,whether α-synuclein pathology can occur spontaneously in peripheral organs independent of exogenous α-synuclein preformed fibrils or pathological α-synuclein leakage from the central nervous system remains under investigation.In this review,we aimed to summarize the role of peripheral α-synuclein pathology in the pathogenesis of Parkinson’s disease.We also discuss the pathways by which α-synuclein pathology spreads from the body to the brain.

Association of daily sitting time and leisure-time physical activity with body fat among U.S.adults

Background:Prolonged sitting and reduced physical activity lead to low energy expenditures.However,little is known about the joint impact of daily sitting time and physical activity on body fat distribution.We investigated the independent and joint associations of daily sitting time and physical activity with body fat among adults.Methods:This was a cross-sectional analysis of U.S.nationally representative data from the National Health and Nutrition Examination Survey2011-2018 among adults aged 20 years or older.Daily sitting time and leisure-time physical activity(LTPA)were self-reported using the Global Physical Activity Questionnaire.Body fat(total and trunk fat percentage)was determined via dual X-ray absorptiometry.Results:Among 10,808 adults,about 54.6%spent 6 h/day or more sitting;more than one-half reported no LTPA(inactive)or less than 150 min/week LTPA(insufficiently active)with only 43.3%reported 150 min/week or more LTPA(active)in the past week.After fully adjusting for sociodemographic data,lifestyle behaviors,and chronic conditions,prolonged sitting time and low levels of LTPA were associated with higher total and trunk fat percentages in both sexes.When stratifying by LTPA,the association between daily sitting time and body fat appeared to be stronger in those who were inactive/insuufficiently active.In the joint analyses,inactive/insuufficiently active adults who reported sitting more than 8 h/day had the highest total(female:3.99%(95%confidence interval(95%CI):3.09%-4.88%);male:3.79%(95%CI:2.75%-4.82%))and trunk body fat percentages(female:4.21%(95%CI:3.09%-5.32%);male:4.07%(95%CI:2.95%-5.19%))when compared with those who were active and sitting less than 4 h/day.Conclusion:Prolonged daily sitting time was associated with increased body fat among U.S.adults.The higher body fat associated with 6 h/day sitting may not be offset by achieving recommended levels of physical activity.

Stereotactic body radiotherapy in pancreatic adenocarcinoma

Background:Stereotactic body radiotherapy(SBRT)in pancreatic cancer allows high delivery of radiation doses on tumors without affecting surrounding tissue.This review aimed at the SBRT application in the treatment of pancreatic cancer.Data sources:We retrieved articles published in MEDLINE/PubMed from January 2017 to December 2022.Keywords used in the search included:“pancreatic adenocarcinoma”OR“pancreatic cancer”AND“stereotactic ablative radiotherapy(SABR)”OR“stereotactic body radiotherapy(SBRT)”OR“chemoradiotherapy(CRT)”.English language articles with information on technical characteristics,doses and fractionation,indications,recurrence patterns,local control and toxicities of SBRT in pancreatic tumors were included.All articles were assessed for validity and relevant content.Results:Optimal doses and fractionation have not yet been defined.However,SBRT could be the standard treatment in patients with pancreatic adenocarcinoma in addition to CRT.Furthermore,the combination of SBRT with chemotherapy may have additive or synergic effect on pancreatic adenocarcinoma.Conclusions:SBRT is an effective modality for patients with pancreatic cancer,supported by clinical practice guidelines as it has demonstrated good tolerance and good disease control.SBRT opens a possibility of improving outcomes for these patients,both in neoadjuvant treatment and with radical intent.

Identification of Mixtures of Two Types of Body Fluids Using the Multiplex Methylation System and Random Forest Models

Objective Body fluid mixtures are complex biological samples that frequently occur in crime scenes,and can provide important clues for criminal case analysis.DNA methylation assay has been applied in the identification of human body fluids,and has exhibited excellent performance in predicting single-source body fluids.The present study aims to develop a methylation SNaPshot multiplex system for body fluid identification,and accurately predict the mixture samples.In addition,the value of DNA methylation in the prediction of body fluid mixtures was further explored.Methods In the present study,420 samples of body fluid mixtures and 250 samples of single body fluids were tested using an optimized multiplex methylation system.Each kind of body fluid sample presented the specific methylation profiles of the 10 markers.Results Significant differences in methylation levels were observed between the mixtures and single body fluids.For all kinds of mixtures,the Spearman’s correlation analysis revealed a significantly strong correlation between the methylation levels and component proportions(1:20,1:10,1:5,1:1,5:1,10:1 and 20:1).Two random forest classification models were trained for the prediction of mixture types and the prediction of the mixture proportion of 2 components,based on the methylation levels of 10 markers.For the mixture prediction,Model-1 presented outstanding prediction accuracy,which reached up to 99.3%in 427 training samples,and had a remarkable accuracy of 100%in 243 independent test samples.For the mixture proportion prediction,Model-2 demonstrated an excellent accuracy of 98.8%in 252 training samples,and 98.2%in 168 independent test samples.The total prediction accuracy reached 99.3%for body fluid mixtures and 98.6%for the mixture proportions.Conclusion These results indicate the excellent capability and powerful value of the multiplex methylation system in the identification of forensic body fluid mixtures.

Association between body mass index and body fat measured by dual-energy X-ray absorptiometry (DXA) in China: a systematic review and meta-analysis

Objective:We examined the association between body mass index(BMI)and body fat percentage(BF%)measured by dual-energy X-ray absorptiometry(DXA)among adults and children in China.Methods:We searched four databases-PubMed,China National Knowledge Infrastructure,Wanfang,and Vip for studies published in the past 22 years.Meta-analysis was conducted using random-or fixed-effect models.Results:In total of 21 studies met inclusion criteria and were included in review,and 17 ot them in meta-analysis.They were conducted across China.Their sample size ranged from 62 to 5726,and participants'age ranged from 6-80 years.Meta-analysis revealed strong associations between BMI and BF% measured by DXA in adults(pooled r=0.71,95% CI:0.66 to 0.74)and children(pooled r=0.60,95% CI:0.52 to 0.68).The association was stronger in Northern China than in East China in children(β=-0.40,95%CI:-0.65 to-0.14)and in Central China in adults(β=-0.25;95% CI:-0.51 to-0.01).Urban children's BMI was strongly associated with BF%than rural(β=0.19;95%CI:0.04 to 0.35),whereas it was stronger in adults living in rural than in urban(β=-0.35;95% CI:-0.66 to-0.05).Conclusions:BMI was strongly associated with BF%measured by DXA,and the association in children and adults in China varied by residence and region.

3D Body解剖软件结合CBL教学法在骨科实习生临床带教中的应用

目的:探讨3D body解剖软件结合CBL教学法在骨科实习生临床带教中的应用效果。方法:随机选取2022年1月~2023年12月在我科室实习的36名骨科实习生为研究对象,随机分为观察组和对照组,对照组采用CBL教学模式,观察组在对照组的教学模式上运用3D body解剖软件。教学结束后,比较两组学生的理论知识考试成绩,PPT汇报成绩以及教学满意度。结果:观察组学生理论知识考核成绩、PPT汇报成绩、教学满意度明显高于对照组,差异具有显著性(P < 0.05)。结论:3D body解剖软件结合CBL教学法应用于骨科实习生临床带教,可以有效提高学生成绩,调动学生积极性及自主学习能力,提升教学满意度。

Energy Harvesting in the Wake of An Inverted C-Shaped Bluff Body

This paper proposes a novel wake-induced vibration(WIV)-based energy harvesting system consisting of two bluff bodies.An inverted C-shaped bluff body is stationary installed at the upstream position to generate an interference wake street,and a cylinder bluff body equipped with a transducer is elastically suspended at the downstream position to harness WIV energy.The hydrodynamics and energy harvesting(EH)performance of the proposed system are investigated via experimental studies.The reduced velocity(U*)ranging from 2 to 14(the corresponding Reynolds number ranging from 15100 to 106200)is considered in the present study.It is found that the wake generated by the inverted C-shaped bluff body significantly affects the EH performance.Enlarging the opening angle(α)of the C-shaped bluff body increases the vibration amplitude of the downstream cylinder,thereby increasing the harvested power.When the spacing(L)between two bluff bodies is two times the cylinder diameter(D),the wake-induced vibration(WIV)mode is observed,while the combined WIV and wake galloping(WG)mode occurs whenαis 150°,and L equals 3D or 4D.The average drag coefficient becomes negative when L is 2D,3D,or 4D.By carefully configuring a C-shaped bluff body,the wake generated by it can bring an augmenting effect on the vibration of the downstream EH cylinder.For example,the RMS power output of the proposed EH system reaches a maximum of 0.31 W at U*=8 and L=4D,which is 300%greater than that of its traditional counterpart.Furthermore,after a number of case stud-ies,it is identified that the proposed EH system can achieve the best performance whenαis 150°and L=2D.

Longitudinal changes in body weight of breastfeeding mothers in the first year after delivery and its relationship with human milk composition:a combined longitudinal and cross-sectional cohort study

Objective:Postpartum weight retention(PPWR)is a common problem among women after childbirth.The main objectives of this study are to understand the changes in body weight of breastfeeding mothers during long-term follow-up and preliminarily explore the relationship between maternal body weight and human milk composition,including macronutrients,leptin,and adiponectin.Methods:The study included a longitudinal cohort(122 mothers),and a cross-sectional cohort(37 mothers).The human milk,maternal weight,and dietary surveys were collected in the longitudinal cohort at different follow-up time points(1-14 days postpartum,2-4 months postpartum,5-7 months postpartum,and 12-17 months postpartum).The maternal body weight was analyzed using the responses in the survey questionnaires.A milk analyzer based on the mid-infrared spectroscopy(MIRS)was used to determine milk composition,and nutrition analysis software evaluated dietary intakes.In the cross-sectional cohort,participating mothers were asked to provide blood and human milk samples and pertinent information related to maternal body composition.Maternal body composition was measured by bioelectrical impedance analysis(BIA),while ELISA analyzed leptin and adiponectin in milk and serum.Results:At 5-7 months postpartum,the PPWR of breastfeeding mothers was(2.46±3.59)kg.At 12-17 months postpartum,the PPWR was(0.98±4.06)kg.PPWR was found to be negatively correlated with milk fat content within 14 days postpartum and positively correlated at 2-4 months postpartum.In addition,the maternal weight and body muscle mass were positively correlated with leptin and adiponectin in milk.Plasma leptin was positively correlated with the mother’s body weight,body mass index(BMI),FAT percentage,and body fat mass,while plasma adiponectin did not correlate with any parameter.The results also indicate that the PPWR did not correlate with leptin and adiponectin in plasma or milk.Conclusions:Breastfeeding mothers may retain considerable weight gain one year after delivery.Human milk composition may be related to changes in maternal body weight.Leptin and adiponectin in breast milk and leptin in plasma are associated with the maternal body composition.This study supports the notion that maternal nutritional status may affect offspring health through lactation,and future research should focus on exploring weight management of postpartum mothers.