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 investi...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.展开更多
Situs inversus totalis(SIT)is a rare homozygous recessive disease caused by the mutation in PKD1L1,which is required for normal interaction with PKD2 and leads to different complications such as respiratory disorders,...Situs inversus totalis(SIT)is a rare homozygous recessive disease caused by the mutation in PKD1L1,which is required for normal interaction with PKD2 and leads to different complications such as respiratory disorders,brain disorders and even obesity.The present study was designed to find out the mutational effect on the binding of PKD2 with mutated PKD1L1,which leads to SIT.The three-dimensional(3D)structure of wild type and mutated PKD1L1 was predicted with>90%confidence using different online tools.The different online tools that were employed were SWISS-MODEL,Phyre2(normal&intensive)and i-TASSER.To compute the physiochemical properties of PKD1L1(wild&mutated)and PKD2 in silico approaches were employed using the ExPASy ProtParam tool.Physicochemical properties such as molecular weight,isoelectric point,the total number of negatively and positively charged residues,extinction coefficient,half-life,instability and aliphatic index,grand average of hydropathicity,and amino acid percentage were calculated.A lot of variability was observed in these parameters among PKD1L1 and PKD2,which accounted for diversification in their functional properties.The theoretical pI points showed that PKD1L1(whole)is more basic with 6.64 pI compared to its first chain TOPO_DOM(amino acids from 1–1748)has a pI of 5.62 which means it is basic while PKD2 have the lowest pI point of 5.34.Docking was performed using the PatchDock and ClusPro online tools.展开更多
Do you spend many hours of the day siting?When you sit,you use less energy than you do when you are active.Siting toomuch hurts yourback,and it's bad for your heart it causes you to gain weight and may even increa...Do you spend many hours of the day siting?When you sit,you use less energy than you do when you are active.Siting toomuch hurts yourback,and it's bad for your heart it causes you to gain weight and may even increase your risk of cancer.How can you avoid siting too much?Every 30minutes,move and stretch.Better on thephone orwatch TV.展开更多
Background:While the relationship between sedentary time and adiposity markers may be independent of moderate-to-vigorous intensity physical activity(MVPA) among adolescents,little is known about the role of light-int...Background:While the relationship between sedentary time and adiposity markers may be independent of moderate-to-vigorous intensity physical activity(MVPA) among adolescents,little is known about the role of light-intensity physical activity(LIPA) in this relationship.The aim of this cross-sectional study was to examine whether device-measured LIPA and MVPA moderate the associations between objectively measured sitting time and adiposity markers(body mass index(BMI)) and waist circumference(WC)) among adolescents.Methods:This study included accelerometer and inclinometer data obtained from 219 adolescents(age=14.9±1.6 years,mean± SD),collected during 2014 and 2015 in Melbourne,Australia.ActiGraph GT3 X accelerometers were used to determine time spent in total-LIPA(101 counts/min to 3.99 metabolic equivalents(METs)) was dichotomized into low-LIPA(101-799 counts/min) and high LIPA(800 counts/min to 3.99 METs),and MVPA(> 4 METs).The average time spent sitting was obtained from activPAL inclinometers.Anthropometric measures were assessed by trained staff.Interactions between sitting and total-LIPA,low-LIPA,high-LIPA,and MVPA on BMI z-score(zBMI) and WC z-score(zWC),respectively,were examined using linear regression,adjusting for age and sex;and moderation by total-LIPA,low-LIPA,high-LIPA,and MVPA were examined by adding interaction terms.Significant interaction effects were probed by comparing associations at the mean and at 1 SD below and above the mean.Results:Total-LIPA significantly moderated the association between sitting time and zBMI,and low-LIPA significantly moderated the association between sitting time and zBMI and zWC.No other associations were found for total-LIPA,high-LIPA,or MVPA.Specifically,at high levels of total-LIPA(+1 SD),there is a negative association between sitting time and zBMI.In addition,at high levels of low-LIPA(+1 SD),there is a negative association between sitting time and zBMI and zWC.Conclusion:Associations between sitting and adiposity depended on time spent in total-LIPA and low-LIPA,but not high-LIPA or MVPA.Results suggest that increasing time spent in LIP A may provide protection from the deleterious effects of sitting on adiposity markers among adolescents.Experimental evidence is needed to support these conclusions.展开更多
Background:Vestibular symptoms on sitting-up are frequent on patients seen by vestibular specialists.Recently,a benign paroxysmal positional vertigo(BPPV)variant which elicits vestibular symptoms with oculomotor evide...Background:Vestibular symptoms on sitting-up are frequent on patients seen by vestibular specialists.Recently,a benign paroxysmal positional vertigo(BPPV)variant which elicits vestibular symptoms with oculomotor evidence of posterior semicircular canal(P-SCC)cupula stimulation on sitting-up was described and named sitting-up vertigo BPPV.A periampullar restricted P-SCC canalolithiasis was proposed as a causal mechanism.Objective:To describe new mechanisms of action for the sitting-up vertigo BPPV variant.Methods:Eighteen patients with sitting-up vertigo BPPV were examined with a pre-established set of positional maneuvers and follow-up until they resolved their symptoms and clinical findings.Results:All patients showed up-beating torsional nystagmus(UBTN)and vestibular symptoms on coming up from either Dix-Hallpike(DHM)or straight head-hanging maneuver.Sixteen out of 18 patients presented a sustained UBTN with an ipsitorsional component to the tested side on half-Hallpike maneuver(HH).A slower persistent contratorsional down-beating nystagmus was found in eleven out18 patients tested on nose down position(ND).Conclusions:Persistent direction changing positional nystagmus on HH and ND positions indicative of PSCC heavy cupula was found in 11 patients.A sustained UBTN on HH with the absence of findings on ND,which is suggestive of the presence of P-SCC short arm canalolithiasis,was found on 5 patients.All patients were treated with canalith repositioning maneuvers without success,but they resolved their findings by means of Brandt-Daroff exercises.We propose P-SCC heavy cupula and P-SCC short arm canalolithiasis as two new putative mechanisms for the sitting-up vertigo BPPV variant.展开更多
The purpose of this study was to examine the hypothesis that the minimum angle-jerk with via-point model could account for the temporal consistency of kinematics in sit-to-stand (STS) and back-to-sit (BTS) movements. ...The purpose of this study was to examine the hypothesis that the minimum angle-jerk with via-point model could account for the temporal consistency of kinematics in sit-to-stand (STS) and back-to-sit (BTS) movements. The positions of bony landmarks on the subjects during the tasks were recorded using a Vicon motion analysis system to yield the angular displacement and position of the center of mass (COM) of a three-link rigid body model in the sagittal plane. Minimum angle-jerk and minimum jerk trajectories with a via-point were computed for joint angle and COM, respectively. Five to six candidate points were selected as the via-point from the measured trajectory based on the separate kinematic events. The results show the optimal angular trajectories using the via-points (via-angles) before the seat-off for STS, and at around the seat-contact for BTS resembles the measured angular trajectories well, indicating that the posture at the via-point was temporally optimal to produce the minimum angle-jerk trajectory for both movements. It is hypothesized that the multi-joint angular patterns during STS and BTS movements were organized to pass through the via-point, namely the via-posture along the minimum angle-jerk trajectory.展开更多
A SIT-BJT model is proposed for static induction thyristors （SITh） operation in the blocking state. On the basis of the physical mechanism, this model is presented analytically in terms of governing equations that l...A SIT-BJT model is proposed for static induction thyristors （SITh） operation in the blocking state. On the basis of the physical mechanism, this model is presented analytically in terms of governing equations that link the electrical parameters to the structural parameters. The model is verified by numerical simulation and theoretical analysis. Based on the model, the variations of the electrical parameters such as the potential barrier, the anode junction voltage drop, and the current amplification factor are studied and discussed.展开更多
文摘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.
文摘Situs inversus totalis(SIT)is a rare homozygous recessive disease caused by the mutation in PKD1L1,which is required for normal interaction with PKD2 and leads to different complications such as respiratory disorders,brain disorders and even obesity.The present study was designed to find out the mutational effect on the binding of PKD2 with mutated PKD1L1,which leads to SIT.The three-dimensional(3D)structure of wild type and mutated PKD1L1 was predicted with>90%confidence using different online tools.The different online tools that were employed were SWISS-MODEL,Phyre2(normal&intensive)and i-TASSER.To compute the physiochemical properties of PKD1L1(wild&mutated)and PKD2 in silico approaches were employed using the ExPASy ProtParam tool.Physicochemical properties such as molecular weight,isoelectric point,the total number of negatively and positively charged residues,extinction coefficient,half-life,instability and aliphatic index,grand average of hydropathicity,and amino acid percentage were calculated.A lot of variability was observed in these parameters among PKD1L1 and PKD2,which accounted for diversification in their functional properties.The theoretical pI points showed that PKD1L1(whole)is more basic with 6.64 pI compared to its first chain TOPO_DOM(amino acids from 1–1748)has a pI of 5.62 which means it is basic while PKD2 have the lowest pI point of 5.34.Docking was performed using the PatchDock and ClusPro online tools.
文摘Do you spend many hours of the day siting?When you sit,you use less energy than you do when you are active.Siting toomuch hurts yourback,and it's bad for your heart it causes you to gain weight and may even increase your risk of cancer.How can you avoid siting too much?Every 30minutes,move and stretch.Better on thephone orwatch TV.
基金funded by the National Institutes for Health (NIH) (R01 HL 111378)AMCA is supported by a Deakin University Postgraduate Research Scholarship (DUPRS)+5 种基金JS was supported by a NHMRC Principal Research Fellowship (APP1026216) during this researchDWD is supported by an NHMRC Senior Research Fellowship (APP1078360)the Victorian Government’s Operational Infrastructure Support ProgramLA is supported by an Alfred Deakin Postdoctoral Research Fellowshipsupported by a National Heart Foundation of Australia Future Leader Fellowship (Award ID 100046) during this researchJS,DWD,and AT received funding support from an NHMRC Centre for Research Excellence Grant (APP1057608)。
文摘Background:While the relationship between sedentary time and adiposity markers may be independent of moderate-to-vigorous intensity physical activity(MVPA) among adolescents,little is known about the role of light-intensity physical activity(LIPA) in this relationship.The aim of this cross-sectional study was to examine whether device-measured LIPA and MVPA moderate the associations between objectively measured sitting time and adiposity markers(body mass index(BMI)) and waist circumference(WC)) among adolescents.Methods:This study included accelerometer and inclinometer data obtained from 219 adolescents(age=14.9±1.6 years,mean± SD),collected during 2014 and 2015 in Melbourne,Australia.ActiGraph GT3 X accelerometers were used to determine time spent in total-LIPA(101 counts/min to 3.99 metabolic equivalents(METs)) was dichotomized into low-LIPA(101-799 counts/min) and high LIPA(800 counts/min to 3.99 METs),and MVPA(> 4 METs).The average time spent sitting was obtained from activPAL inclinometers.Anthropometric measures were assessed by trained staff.Interactions between sitting and total-LIPA,low-LIPA,high-LIPA,and MVPA on BMI z-score(zBMI) and WC z-score(zWC),respectively,were examined using linear regression,adjusting for age and sex;and moderation by total-LIPA,low-LIPA,high-LIPA,and MVPA were examined by adding interaction terms.Significant interaction effects were probed by comparing associations at the mean and at 1 SD below and above the mean.Results:Total-LIPA significantly moderated the association between sitting time and zBMI,and low-LIPA significantly moderated the association between sitting time and zBMI and zWC.No other associations were found for total-LIPA,high-LIPA,or MVPA.Specifically,at high levels of total-LIPA(+1 SD),there is a negative association between sitting time and zBMI.In addition,at high levels of low-LIPA(+1 SD),there is a negative association between sitting time and zBMI and zWC.Conclusion:Associations between sitting and adiposity depended on time spent in total-LIPA and low-LIPA,but not high-LIPA or MVPA.Results suggest that increasing time spent in LIP A may provide protection from the deleterious effects of sitting on adiposity markers among adolescents.Experimental evidence is needed to support these conclusions.
文摘Background:Vestibular symptoms on sitting-up are frequent on patients seen by vestibular specialists.Recently,a benign paroxysmal positional vertigo(BPPV)variant which elicits vestibular symptoms with oculomotor evidence of posterior semicircular canal(P-SCC)cupula stimulation on sitting-up was described and named sitting-up vertigo BPPV.A periampullar restricted P-SCC canalolithiasis was proposed as a causal mechanism.Objective:To describe new mechanisms of action for the sitting-up vertigo BPPV variant.Methods:Eighteen patients with sitting-up vertigo BPPV were examined with a pre-established set of positional maneuvers and follow-up until they resolved their symptoms and clinical findings.Results:All patients showed up-beating torsional nystagmus(UBTN)and vestibular symptoms on coming up from either Dix-Hallpike(DHM)or straight head-hanging maneuver.Sixteen out of 18 patients presented a sustained UBTN with an ipsitorsional component to the tested side on half-Hallpike maneuver(HH).A slower persistent contratorsional down-beating nystagmus was found in eleven out18 patients tested on nose down position(ND).Conclusions:Persistent direction changing positional nystagmus on HH and ND positions indicative of PSCC heavy cupula was found in 11 patients.A sustained UBTN on HH with the absence of findings on ND,which is suggestive of the presence of P-SCC short arm canalolithiasis,was found on 5 patients.All patients were treated with canalith repositioning maneuvers without success,but they resolved their findings by means of Brandt-Daroff exercises.We propose P-SCC heavy cupula and P-SCC short arm canalolithiasis as two new putative mechanisms for the sitting-up vertigo BPPV variant.
文摘The purpose of this study was to examine the hypothesis that the minimum angle-jerk with via-point model could account for the temporal consistency of kinematics in sit-to-stand (STS) and back-to-sit (BTS) movements. The positions of bony landmarks on the subjects during the tasks were recorded using a Vicon motion analysis system to yield the angular displacement and position of the center of mass (COM) of a three-link rigid body model in the sagittal plane. Minimum angle-jerk and minimum jerk trajectories with a via-point were computed for joint angle and COM, respectively. Five to six candidate points were selected as the via-point from the measured trajectory based on the separate kinematic events. The results show the optimal angular trajectories using the via-points (via-angles) before the seat-off for STS, and at around the seat-contact for BTS resembles the measured angular trajectories well, indicating that the posture at the via-point was temporally optimal to produce the minimum angle-jerk trajectory for both movements. It is hypothesized that the multi-joint angular patterns during STS and BTS movements were organized to pass through the via-point, namely the via-posture along the minimum angle-jerk trajectory.
文摘A SIT-BJT model is proposed for static induction thyristors （SITh） operation in the blocking state. On the basis of the physical mechanism, this model is presented analytically in terms of governing equations that link the electrical parameters to the structural parameters. The model is verified by numerical simulation and theoretical analysis. Based on the model, the variations of the electrical parameters such as the potential barrier, the anode junction voltage drop, and the current amplification factor are studied and discussed.
