试验发现了钢绞线结构中L（0,1）模态导波存在陷频这一固有声学特性,由此提出一种钢绞线拉力检测新方法。为测试钢绞线中导波陷频特性与拉力的关系,研制了一款柔性低频磁致伸缩传感器,可在30~160 k Hz范围内激励/接收L（0,1）模态导波...试验发现了钢绞线结构中L（0,1）模态导波存在陷频这一固有声学特性,由此提出一种钢绞线拉力检测新方法。为测试钢绞线中导波陷频特性与拉力的关系,研制了一款柔性低频磁致伸缩传感器,可在30~160 k Hz范围内激励/接收L（0,1）模态导波。在直径17.8 mm和15.2 mm的两种7芯钢绞线上进行导波陷频检测试验,结果表明陷频特征频率与拉力的自然对数值呈良好线性关系,陷频旁侧峰值比随拉力增大而线性增加。试验中1 k N的拉力增量（应力增量约3 MPa）引起的声学参数（陷频特征频率和陷频旁侧峰值比）变化可被检测到并较好的符合标定关系方程。在额定工作载荷内,拉力估算相对误差小于1.5%,这表明新方法具有较高的拉力检测精度。同时,依据试验所得结论,给出了钢绞线结构中L（0,1）模态导波陷频中心频率与拉力关系的修正公式。新方法实施过程简洁,具有很好的工程应用前景。展开更多
Objective::This study investigated the prospective associations of circulating levels of sex hormone-binding globulin(SHBG)levels with cardiometabolic biomarkers and risk of gestational diabetes(GDM)during pregnancy.I...Objective::This study investigated the prospective associations of circulating levels of sex hormone-binding globulin(SHBG)levels with cardiometabolic biomarkers and risk of gestational diabetes(GDM)during pregnancy.It also examines the longitudinal trajectory of SHBG in women with and without GDM.Methods::We conducted a nested case-control study of 107 incident GDM cases and 214 matched controls within the Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Growth Studies-Singleton Cohort.The cohort enrolled non-obese and obese women aged 18-40 years with a singleton pregnancy between 8 and 13 weeks of gestation from 2009 to 2013.GDM was ascertained via medical records review.Blood samples were drawn four times at gestational weeks 10-14,15-26,23-31,and 33-39.The prospective associations between SHBG levels and cardiometabolic biomarkers were examined using the Spearman partial correlation among the controls.The longitudinal trajectories of SHBG levels were examined among the cases and the controls.Meta-analysis of prospective studies were performed to examine the association between SHBG levels and GDM risk.Results::SHBG levels at gestational weeks 10-14 were significantly inversely associated with fasting insulin(r=-0.17,P=0.01)and insulin resistance as measured by HOMA-IR(r=-0.17,P=0.01)at gestational week 15-26.SHBG at gestational weeks 10-14 and 15-26 was lower in cases than controls(mean±standard deviation:(204.0±97.6)vs.(220.9±102.5)nmol/L,P=0.16 and(305.6±124.3)vs.(322.7±105.1)nmol/L,P=0.14,respectively),yet the differences were not significant.In the meta-analysis,SHBG was 41.5 nmol/L(95%confidence interval:23.9,59.1,P<0.01)significantly lower among women with GDM than without,and each 50 nmol/L increase in SHBG was significantly associated with an odds ratio of 0.85(95%confidence interval:0.76-0.95,P=0.01)for GDM.Conclusion::Lower SHBG levels in early pregnancy were prospectively associated with higher high insulin levels and insulin resistance in mid-pregnancy an展开更多
The compact,sensitive,and multidimensional displacement measurement device plays a crucial role in semiconductor manufacture and high-resolution optical imaging.The metasurface offers a promising solution to develop h...The compact,sensitive,and multidimensional displacement measurement device plays a crucial role in semiconductor manufacture and high-resolution optical imaging.The metasurface offers a promising solution to develop high-precision displacement metrology.In this work,we proposed and experimentally demonstrated a two-dimensional displacement(XZ)measurement device by a dielectric metasurface.Both transversal and longitudinal displacements of the metasurface can be obtained by the analysis of the interference optical intensity that is generated by the deflected light beams while the metasurface is under linearly polarized incidence.We experimentally demonstrated that displacements down to 5.4 nm along the x-axis and 0.12μm along the z-axis can be resolved with a 900μm×900μm metasurface.Our work opens up new possibilities to develop a compact high-precision multidimensional displacement sensor.展开更多
It has been hypothesized that key lifestyle behaviors of physical activity and sleep worsened in response to the Coronavirus disease(COVID-19)pandemic.However,there have been inconsistencies in findings of changes in ...It has been hypothesized that key lifestyle behaviors of physical activity and sleep worsened in response to the Coronavirus disease(COVID-19)pandemic.However,there have been inconsistencies in findings of changes in these key lifestyle behaviors across populations likely due to the wide variety of assessment methods.The purpose of the study was to compare physical activity and sleep before and after the COVID-19 pandemic using accelerometers and self-reported behaviors.A longitudinal follow-up was conducted on students,faculty,and staff at a university campus in the United States.In the periods before March 2020(covering the academic years of 2018–2019 or 2019–2020)and again in April–June 2021,participants completed surveys to evaluate their physical activity and sleep behaviors and wore an accelerometer.A total of 44 participants completed the survey at both timepoints and 32 completed accelerometer assessment at both timepoints.Fifty-seven percent of participants reported a perceived decline in physical activity,while 30%reported a worsening in sleep.From selfreported data,overall physical activity did not change,but there was a decrease in active transport(p<0.001)and increase in domestic physical activity(p?0.012).Sleep quality decreased as evidenced by an increase in Pittsburgh Sleep Quality Index scores(p?0.045).There were no changes in accelerometer measured physical activity or sleep.There were no changes in physical or mental health.While perceptions of physical activity declined from prior to the COVID-19 pandemic,there were no changes in device-measured physical activity,and changes in self-reported physical activity differed by domain.展开更多
AIM To investigate the association of urinary chemokines with the treatment response in chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS) patients.METHODS Between 2007-2011,18 out of 21 male CP/CPPS patients m...AIM To investigate the association of urinary chemokines with the treatment response in chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS) patients.METHODS Between 2007-2011,18 out of 21 male CP/CPPS patients met the exclusion/inclusion criteria of the 16 wk longitudinal study on twice daily oral treatment with Phosphodiesterase 4 inhibitor called Apremilast for 12 wk. Symptom scores and urine specimen were collected at baseline and every visit at 4 wk interval from CP/CPPS patients who completed at least 8 wk of drug treatment. Urine collected at each visit was frozen and then analyzed together after thawing for chemokines and growth factors using MILLIPLEX? MAP immunoassay. Cross sectional association of Chronic Prostatitis Symptom Index(CPSI) and visual analog scale(VAS) with chemokine levels in urine collected at baseline was assessed in 18 CP/CPPS patients relative to 10 asymptomatic male subjects. Longitudinal association between urine chemokine levels and symptom scores was assessed in 8 treatmentadherent CP/CPPS patients at baseline and at 4,8,12 and 16 wk.RESULTS Urine chemokines levels of CXCL-1(GRO-a),CXCL-8(IL-8),CXCL-10(IP-10) and CCL5(RANTES) in CP/CPPS patients at baseline were significantly elevated relative to asymptomatic subjects,whereas levels of s IL-1RA in CP/CPPS were significantly lower compared to controls(P <0.05). Quantitatively,urine levels of CXCL-10 were higher than other chemokines in CP/CPPS,but its fold change of5 relative to controls was lower than the 20 fold change noted for CXCL-8. The mean age of enrolled patients who completed at least 8 wk of treatment(n = 8) was 46.5± 9.4 years and analysis found that elevation of CXCL-8and CCL5 increased the odds for higher score of CPSI by54% and 25%,respectively(F test,P = 0.00007). Urine levels of CCL2(MCP-1) and CXCL-10 together explained approximately 85% of variance in longitudinal data on multivariate analysis. Bivariate analysis of 5 patients who fully complied and completed the assigned dose regimen,showed strong linear c展开更多
文摘试验发现了钢绞线结构中L（0,1）模态导波存在陷频这一固有声学特性,由此提出一种钢绞线拉力检测新方法。为测试钢绞线中导波陷频特性与拉力的关系,研制了一款柔性低频磁致伸缩传感器,可在30~160 k Hz范围内激励/接收L（0,1）模态导波。在直径17.8 mm和15.2 mm的两种7芯钢绞线上进行导波陷频检测试验,结果表明陷频特征频率与拉力的自然对数值呈良好线性关系,陷频旁侧峰值比随拉力增大而线性增加。试验中1 k N的拉力增量（应力增量约3 MPa）引起的声学参数（陷频特征频率和陷频旁侧峰值比）变化可被检测到并较好的符合标定关系方程。在额定工作载荷内,拉力估算相对误差小于1.5%,这表明新方法具有较高的拉力检测精度。同时,依据试验所得结论,给出了钢绞线结构中L（0,1）模态导波陷频中心频率与拉力关系的修正公式。新方法实施过程简洁,具有很好的工程应用前景。
基金supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development intramural funding and included American Recovery and Reinvestment Act funding via contract numbers HHSN275200800013C,HHSN275200800002I,HHSN27500006,HHSN275200800003IC,HHSN275200800014C,HHSN275200800012C,HHSN275200800028C,HHSN275201000009C,and HHSN275201000001Zsupported by a mentored research scientist development award from the National Institutes of Health Office of the Director and the Building Interdisciplinary Research Careers in Women's Health program(3K12HD052163).
文摘Objective::This study investigated the prospective associations of circulating levels of sex hormone-binding globulin(SHBG)levels with cardiometabolic biomarkers and risk of gestational diabetes(GDM)during pregnancy.It also examines the longitudinal trajectory of SHBG in women with and without GDM.Methods::We conducted a nested case-control study of 107 incident GDM cases and 214 matched controls within the Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Growth Studies-Singleton Cohort.The cohort enrolled non-obese and obese women aged 18-40 years with a singleton pregnancy between 8 and 13 weeks of gestation from 2009 to 2013.GDM was ascertained via medical records review.Blood samples were drawn four times at gestational weeks 10-14,15-26,23-31,and 33-39.The prospective associations between SHBG levels and cardiometabolic biomarkers were examined using the Spearman partial correlation among the controls.The longitudinal trajectories of SHBG levels were examined among the cases and the controls.Meta-analysis of prospective studies were performed to examine the association between SHBG levels and GDM risk.Results::SHBG levels at gestational weeks 10-14 were significantly inversely associated with fasting insulin(r=-0.17,P=0.01)and insulin resistance as measured by HOMA-IR(r=-0.17,P=0.01)at gestational week 15-26.SHBG at gestational weeks 10-14 and 15-26 was lower in cases than controls(mean±standard deviation:(204.0±97.6)vs.(220.9±102.5)nmol/L,P=0.16 and(305.6±124.3)vs.(322.7±105.1)nmol/L,P=0.14,respectively),yet the differences were not significant.In the meta-analysis,SHBG was 41.5 nmol/L(95%confidence interval:23.9,59.1,P<0.01)significantly lower among women with GDM than without,and each 50 nmol/L increase in SHBG was significantly associated with an odds ratio of 0.85(95%confidence interval:0.76-0.95,P=0.01)for GDM.Conclusion::Lower SHBG levels in early pregnancy were prospectively associated with higher high insulin levels and insulin resistance in mid-pregnancy an
基金supported by the National Natural Science Foundation of China(No.U20A20216)the Technology Domain Fund of 173 Project(No.2021-JCJQ-JJ-0284)。
文摘The compact,sensitive,and multidimensional displacement measurement device plays a crucial role in semiconductor manufacture and high-resolution optical imaging.The metasurface offers a promising solution to develop high-precision displacement metrology.In this work,we proposed and experimentally demonstrated a two-dimensional displacement(XZ)measurement device by a dielectric metasurface.Both transversal and longitudinal displacements of the metasurface can be obtained by the analysis of the interference optical intensity that is generated by the deflected light beams while the metasurface is under linearly polarized incidence.We experimentally demonstrated that displacements down to 5.4 nm along the x-axis and 0.12μm along the z-axis can be resolved with a 900μm×900μm metasurface.Our work opens up new possibilities to develop a compact high-precision multidimensional displacement sensor.
文摘It has been hypothesized that key lifestyle behaviors of physical activity and sleep worsened in response to the Coronavirus disease(COVID-19)pandemic.However,there have been inconsistencies in findings of changes in these key lifestyle behaviors across populations likely due to the wide variety of assessment methods.The purpose of the study was to compare physical activity and sleep before and after the COVID-19 pandemic using accelerometers and self-reported behaviors.A longitudinal follow-up was conducted on students,faculty,and staff at a university campus in the United States.In the periods before March 2020(covering the academic years of 2018–2019 or 2019–2020)and again in April–June 2021,participants completed surveys to evaluate their physical activity and sleep behaviors and wore an accelerometer.A total of 44 participants completed the survey at both timepoints and 32 completed accelerometer assessment at both timepoints.Fifty-seven percent of participants reported a perceived decline in physical activity,while 30%reported a worsening in sleep.From selfreported data,overall physical activity did not change,but there was a decrease in active transport(p<0.001)and increase in domestic physical activity(p?0.012).Sleep quality decreased as evidenced by an increase in Pittsburgh Sleep Quality Index scores(p?0.045).There were no changes in accelerometer measured physical activity or sleep.There were no changes in physical or mental health.While perceptions of physical activity declined from prior to the COVID-19 pandemic,there were no changes in device-measured physical activity,and changes in self-reported physical activity differed by domain.
文摘AIM To investigate the association of urinary chemokines with the treatment response in chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS) patients.METHODS Between 2007-2011,18 out of 21 male CP/CPPS patients met the exclusion/inclusion criteria of the 16 wk longitudinal study on twice daily oral treatment with Phosphodiesterase 4 inhibitor called Apremilast for 12 wk. Symptom scores and urine specimen were collected at baseline and every visit at 4 wk interval from CP/CPPS patients who completed at least 8 wk of drug treatment. Urine collected at each visit was frozen and then analyzed together after thawing for chemokines and growth factors using MILLIPLEX? MAP immunoassay. Cross sectional association of Chronic Prostatitis Symptom Index(CPSI) and visual analog scale(VAS) with chemokine levels in urine collected at baseline was assessed in 18 CP/CPPS patients relative to 10 asymptomatic male subjects. Longitudinal association between urine chemokine levels and symptom scores was assessed in 8 treatmentadherent CP/CPPS patients at baseline and at 4,8,12 and 16 wk.RESULTS Urine chemokines levels of CXCL-1(GRO-a),CXCL-8(IL-8),CXCL-10(IP-10) and CCL5(RANTES) in CP/CPPS patients at baseline were significantly elevated relative to asymptomatic subjects,whereas levels of s IL-1RA in CP/CPPS were significantly lower compared to controls(P <0.05). Quantitatively,urine levels of CXCL-10 were higher than other chemokines in CP/CPPS,but its fold change of5 relative to controls was lower than the 20 fold change noted for CXCL-8. The mean age of enrolled patients who completed at least 8 wk of treatment(n = 8) was 46.5± 9.4 years and analysis found that elevation of CXCL-8and CCL5 increased the odds for higher score of CPSI by54% and 25%,respectively(F test,P = 0.00007). Urine levels of CCL2(MCP-1) and CXCL-10 together explained approximately 85% of variance in longitudinal data on multivariate analysis. Bivariate analysis of 5 patients who fully complied and completed the assigned dose regimen,showed strong linear c
