The harmonic index of a graph?G? is defined as where d(u) denotes the degree of a vertex u in G . In this work, we give another expression for the Harmonic index. Using this expression, we give the minimum value of th...The harmonic index of a graph?G? is defined as where d(u) denotes the degree of a vertex u in G . In this work, we give another expression for the Harmonic index. Using this expression, we give the minimum value of the harmonic index for any triangle-free graphs with order n and minimum degree δ ≥ k for k≤ n/2? and show the corresponding extremal graph is the complete graph.展开更多
Objective: Increased testosterone and decreased sex hormone-binding globulin (SHBG) are associated with a number of adverse cardiovascular risk factors in postmenopausal women. The aim of this population-based study o...Objective: Increased testosterone and decreased sex hormone-binding globulin (SHBG) are associated with a number of adverse cardiovascular risk factors in postmenopausal women. The aim of this population-based study of women aged 25 to 50 was to assess the relationship between free androgen index (FAI) and cardiovascular risk factors in premenopausal women. Methods: A population-based survey of 396 premenopausal women with no hormonal treatment was undertaken as part of the Northern MONICA study. The study involved questionnaires, anthropometry and assays of testosterone and SHBG. Results: Increased FAI was associated with a number of cardiovascular risk factors in premenopausal women but this relationship was strongly affected by body mass index (BMI). After adjustment for age and BMI, FAI was significantly associated with increased systolic and diastolic blood pressures. Conclusion: Hyperandrogenism is associated with increased blood pressure and these findings emphasize the need to assess cardiovascular risk factors in women with hyperandrogenism of all ages.展开更多
The composition and concentration of dissolved free amino acid(DFAA)of seawater samples collected in May 2016 from the surface to the hadal zone of the northern region of the Yap Trench were analyzed by pre-column der...The composition and concentration of dissolved free amino acid(DFAA)of seawater samples collected in May 2016 from the surface to the hadal zone of the northern region of the Yap Trench were analyzed by pre-column derivatization of o-phthalaldehyde.Results show that the average concentration of DFAA in the study area was 0.47±0.36μmol/L.In different sampling stations,the concentrations of DFAA with water depth showed complex variation patterns.At the sediment-seawater interface,the concentrations of DFAA in the western side of the trench were obviously higher than that in its eastern side.In the study area,there were no significant correlations between the concentrations of DFAA and the environmental parameters such as concentrations of chlorophyll a(Chl a),dissolved oxygen(DO),pH,and dissolved inorganic nitrogen(DIN),indicating that the concentrations of DFAA in seawater of the trench are affected by many factors,such as photosynthesis,respiration,temperature,pressure,illumination,and circulation.The dominant DFAA are similar in different water layers of sampling stations,including aspartic acid(Asp),glutamic acid(Glu),glycine(Gly),and serine(Ser).The composition of different amino acids,and the relative abundance of acidic,basic,and neutral amino acids might be related to the sources and consumption of various amino acids.Nine pairs of amino acids in the DFAA showed significantly positive relationship by correlation matrix analysis,suggesting that they might share similar biogeochemical processes.The degradation index(DI)of the DFAA in seawater of the Yap Trench could reflect the degradation,source,and freshness of DFAA in the trench to some extents.This is a preliminary study of amino acids from sea surface to hadal zone in the ocean,more works shall be done in different trenches to reveal their biogeochemical characte ristics in extreme marine environme nts.展开更多
The introduction of a new concept of space-energy duality serves to extend the applicability of the Einstein field equation in the context of a 4-index framework. The utilization of the Weyl tensor enables the derivat...The introduction of a new concept of space-energy duality serves to extend the applicability of the Einstein field equation in the context of a 4-index framework. The utilization of the Weyl tensor enables the derivation of Einstein’s equations in the 4-index format. Additionally, a two-index field equation is presented, comprising a conventional Einstein field equation and a trace-free Einstein equation. Notably, the cosmological constant is associated with a novel concept that facilitates the encoding of space and energy information, thereby enabling the recognition of mutual interactions between space and energy in the presence of gravitational forces, as dictated by Einstein’s field equations (EFE) and Trace-Free Einstein Equation (TFE).展开更多
目的:探究江苏省部分地区不同性别成年人脂肪质量随年龄增长的变化情况以及不同年龄段人群体质量指数(body fat index,BMI)和脂肪质量之间的关系。方法:收集2019年9月至2021年2月江苏省南京市、淮安市以及无锡市的体检人群数据,对符合...目的:探究江苏省部分地区不同性别成年人脂肪质量随年龄增长的变化情况以及不同年龄段人群体质量指数(body fat index,BMI)和脂肪质量之间的关系。方法:收集2019年9月至2021年2月江苏省南京市、淮安市以及无锡市的体检人群数据,对符合纳入标准人群进行体格检查和体成分检测,并分析其脂肪质量随年龄变化情况。结果:共收集2115名志愿者的基本信息,排除信息不全者46名,共纳入2069名进行研究分析。30岁以上成年人去脂体质量(fat free mass,FFM)随着年龄的增长呈现下降的趋势;30岁以上成年人的体脂肪量(body fat mass,BFM)、体脂百分比(percentage of body fat,PBF)、腰臀比(waist-hip ratio,WHR)和体脂指数(fat mass index,FMI)随着年龄的增长均呈现上升趋势,BFM、PBF和去脂体质量百分比(percentage of fat free mass,PFFM)在40岁出现显著上升,FFM和去脂体质量指数(fat free mass index,FFMI)在60岁开始出现显著下降。男性FMI在40岁出现显著上升,女性FMI从60岁出现显著上升。全年龄段成年人FFM随着BMI和腰围水平的升高呈上升趋势。结论:随着年龄的增长男性和女性的BFM、PBF和WHR均呈现上升趋势。各年龄段成年男性FFM显著高于女性,女性BFM、FMI、PBF和内脏脂肪面积显著高于男性。全年龄段成年人FFM随着BMI和WHR升高呈上升趋势。展开更多
文摘The harmonic index of a graph?G? is defined as where d(u) denotes the degree of a vertex u in G . In this work, we give another expression for the Harmonic index. Using this expression, we give the minimum value of the harmonic index for any triangle-free graphs with order n and minimum degree δ ≥ k for k≤ n/2? and show the corresponding extremal graph is the complete graph.
文摘Objective: Increased testosterone and decreased sex hormone-binding globulin (SHBG) are associated with a number of adverse cardiovascular risk factors in postmenopausal women. The aim of this population-based study of women aged 25 to 50 was to assess the relationship between free androgen index (FAI) and cardiovascular risk factors in premenopausal women. Methods: A population-based survey of 396 premenopausal women with no hormonal treatment was undertaken as part of the Northern MONICA study. The study involved questionnaires, anthropometry and assays of testosterone and SHBG. Results: Increased FAI was associated with a number of cardiovascular risk factors in premenopausal women but this relationship was strongly affected by body mass index (BMI). After adjustment for age and BMI, FAI was significantly associated with increased systolic and diastolic blood pressures. Conclusion: Hyperandrogenism is associated with increased blood pressure and these findings emphasize the need to assess cardiovascular risk factors in women with hyperandrogenism of all ages.
基金Supported by the Natural National Science Foundation of China(Nos.42076040,41676067)the National Basic Research Program of China(973 Program)(No.2015CB755904)the 111 Project(No.B13030)。
文摘The composition and concentration of dissolved free amino acid(DFAA)of seawater samples collected in May 2016 from the surface to the hadal zone of the northern region of the Yap Trench were analyzed by pre-column derivatization of o-phthalaldehyde.Results show that the average concentration of DFAA in the study area was 0.47±0.36μmol/L.In different sampling stations,the concentrations of DFAA with water depth showed complex variation patterns.At the sediment-seawater interface,the concentrations of DFAA in the western side of the trench were obviously higher than that in its eastern side.In the study area,there were no significant correlations between the concentrations of DFAA and the environmental parameters such as concentrations of chlorophyll a(Chl a),dissolved oxygen(DO),pH,and dissolved inorganic nitrogen(DIN),indicating that the concentrations of DFAA in seawater of the trench are affected by many factors,such as photosynthesis,respiration,temperature,pressure,illumination,and circulation.The dominant DFAA are similar in different water layers of sampling stations,including aspartic acid(Asp),glutamic acid(Glu),glycine(Gly),and serine(Ser).The composition of different amino acids,and the relative abundance of acidic,basic,and neutral amino acids might be related to the sources and consumption of various amino acids.Nine pairs of amino acids in the DFAA showed significantly positive relationship by correlation matrix analysis,suggesting that they might share similar biogeochemical processes.The degradation index(DI)of the DFAA in seawater of the Yap Trench could reflect the degradation,source,and freshness of DFAA in the trench to some extents.This is a preliminary study of amino acids from sea surface to hadal zone in the ocean,more works shall be done in different trenches to reveal their biogeochemical characte ristics in extreme marine environme nts.
文摘The introduction of a new concept of space-energy duality serves to extend the applicability of the Einstein field equation in the context of a 4-index framework. The utilization of the Weyl tensor enables the derivation of Einstein’s equations in the 4-index format. Additionally, a two-index field equation is presented, comprising a conventional Einstein field equation and a trace-free Einstein equation. Notably, the cosmological constant is associated with a novel concept that facilitates the encoding of space and energy information, thereby enabling the recognition of mutual interactions between space and energy in the presence of gravitational forces, as dictated by Einstein’s field equations (EFE) and Trace-Free Einstein Equation (TFE).
文摘目的:探究江苏省部分地区不同性别成年人脂肪质量随年龄增长的变化情况以及不同年龄段人群体质量指数(body fat index,BMI)和脂肪质量之间的关系。方法:收集2019年9月至2021年2月江苏省南京市、淮安市以及无锡市的体检人群数据,对符合纳入标准人群进行体格检查和体成分检测,并分析其脂肪质量随年龄变化情况。结果:共收集2115名志愿者的基本信息,排除信息不全者46名,共纳入2069名进行研究分析。30岁以上成年人去脂体质量(fat free mass,FFM)随着年龄的增长呈现下降的趋势;30岁以上成年人的体脂肪量(body fat mass,BFM)、体脂百分比(percentage of body fat,PBF)、腰臀比(waist-hip ratio,WHR)和体脂指数(fat mass index,FMI)随着年龄的增长均呈现上升趋势,BFM、PBF和去脂体质量百分比(percentage of fat free mass,PFFM)在40岁出现显著上升,FFM和去脂体质量指数(fat free mass index,FFMI)在60岁开始出现显著下降。男性FMI在40岁出现显著上升,女性FMI从60岁出现显著上升。全年龄段成年人FFM随着BMI和腰围水平的升高呈上升趋势。结论:随着年龄的增长男性和女性的BFM、PBF和WHR均呈现上升趋势。各年龄段成年男性FFM显著高于女性,女性BFM、FMI、PBF和内脏脂肪面积显著高于男性。全年龄段成年人FFM随着BMI和WHR升高呈上升趋势。
