目的分析2型糖尿病患者25-羟维生素D[25(OH)D]水平,初步了解血清25(OH)D水平与2型糖尿病患者糖化血红蛋白(HbA1c)、胰岛功能等代谢指标的相关性。方法选择新乡市第一人民医院内分泌科2020年1月至2020年12月收治的459例2型糖尿病患者为...目的分析2型糖尿病患者25-羟维生素D[25(OH)D]水平,初步了解血清25(OH)D水平与2型糖尿病患者糖化血红蛋白(HbA1c)、胰岛功能等代谢指标的相关性。方法选择新乡市第一人民医院内分泌科2020年1月至2020年12月收治的459例2型糖尿病患者为研究对象。收集患者的临床资料,包括性别、年龄、血清25(OH)D、空腹胰岛素、C肽、HbA1c、空腹血糖、餐后血糖、尿微量白蛋白、尿白蛋白肌酐比值、血钙、血尿酸(UA)、三酰甘油(TG)、总胆固醇(TCH)、低密度脂蛋白(LDL)、高密度脂蛋白(HDL)等。根据血清25(OH)D水平将患者分为充足组[n=20,25(OH)D≥30μg·L^(-1)]、不足组[n=95,20μg·L^(-1)≤25(OH)D<30μg·L^(-1)]、缺乏组[n=231,10μg·L^(-1)≤25(OH)D<20μg·L^(-1)]、严重缺乏组[n=113,25(OH)D<10μg·L^(-1)]。比较4组患者各代谢指标的差异,采用Pearson相关分析25(OH)D与各代谢指标的相关性。结果2型糖尿病患者血清25(OH)D水平为3.00~46.59(15.75±0.35)μg·L^(-1),男性患者的血清25(OH)D水平显著高于女性患者(P<0.05)。2型糖尿病患者25(OH)D缺乏的患病率为74.9%(344/459),25(OH)D缺乏主要发生在1、2、3、4、11、12月份。不足组、缺乏组和严重缺乏组患者HbA1c显著高于充足组(P<0.05),缺乏组和严重缺乏组患者HbA1c显著高于不足组(P<0.05);缺乏组和严重缺乏组患者HbA1c比较差异无统计学意义(P>0.05)。充足组与不足组、缺乏组与严重缺乏组患者空腹血糖比较差异无统计学意义(P>0.05);缺乏组和严重缺乏组患者空腹血糖显著高于充足组、不足组(P<0.05)。充足组、不足组、缺乏组患者空腹胰岛素、尿微量白蛋白、日尿白蛋白总量、尿白蛋白肌酐比值比较差异无统计学意义(P>0.05);严重缺乏组患者空腹胰岛素显著低于充足组、不足组和缺乏组,尿微量白蛋白、日尿白蛋白总量、尿白蛋白肌酐比值显著高于充足组、不足组和缺乏组(P<0.05)。4组患者的稳态模型评估的胰岛素抵抗指数(HOMA-IR)、血清白蛋白、血肌酐、餐后1 h血糖、餐后2 h血糖、餐后3 h血糖、空腹C肽、餐后1 h C肽、餐后2 h C肽、餐后3 h C肽、TG、TCH、LDL、HDL、血UA、血钙比较差异均无统计学意义(P>0.05)。Pearson相关性分析结果显示,2型糖尿病患者血清25(OH)D水平与HbA1c、尿微量白蛋白、尿白蛋白肌酐比值呈负相关(r=-0.093、-0.166、-0.157,P<0.05),与空腹胰岛素呈正相关(r=0.089,P<0.05)。2型糖尿病患者血清25(OH)D水平与空腹血糖、HOMA-IR、血清白蛋白、血肌酐、餐后1 h血糖、餐后2 h血糖、餐后3 h血糖、空腹C肽、餐后1 h C肽、餐后2 h C肽、餐后3 h C肽、TG、TCH、LDL、HDL、血UA、血钙等无相关性(P>0.05)。结论2型糖尿病患者25(OH)D缺乏与不足普遍存在,女性患者缺乏更明显。2型糖尿病患者25(OH)D水平与空腹胰岛素呈正相关,与HbA1c、尿微量白蛋白、尿白蛋白肌酐比值呈负相关,25(OH)D缺乏的2型糖尿病患者主要分布在1、2、3、4、11、12月份。展开更多
Aim: To investigate the relationship between 2D:4D and testosterone in men attending an infertility clinic and men drawn from the general population. Methods: Data on 2D:4D and testosterone from two samples were colle...Aim: To investigate the relationship between 2D:4D and testosterone in men attending an infertility clinic and men drawn from the general population. Methods: Data on 2D:4D and testosterone from two samples were collected: (1) 43 men attending an infertility clinic, and (2) 51 men drawn from the general population without regard to fertility. Results: In sample (1) there were negative associations between 2D:4D and testicular function, and men with lower 2D:4D in their right compared to left hand had higher testosterone levels than men with higher 2D:4D in their right compared to left hand. Sample (2) showed no significant associations between 2D:4D or side differences in 2E>:4D and testosterone. Conclusion: Adult levels of testosterone may be related to aspects of 2D:4D in samples which contain men with compromised testicular function, but not in men from normative samples. Associations between 2D:4D and fertility-associated traits probably arise from early organisational effects of testosterone rather than from activational effects of current testosterone.展开更多
A method for recycling AZ91D magnesium alloy scraps directly by hot extrusion was studied.Various microstructural analyses were performed using the techniques of optical microscopy,scanning electron microscopy(SEM)and...A method for recycling AZ91D magnesium alloy scraps directly by hot extrusion was studied.Various microstructural analyses were performed using the techniques of optical microscopy,scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS).Microstructural observations revealed that all the recycled specimens consisted of fine grains due to the dynamic recrystallization.The main strengthening mechanism of the recycled specimen was grain refinement strengthening and homogeneous distribution of oxide precipitates.The interfaces of individual scraps of extruded materials were not identified when the scraps were extruded with the extrusion ratio of 40-1.Oxidation layers of the scraps were broken into pieces by high compressive and shear forces under the extrusion ratio of 40-1.The ultimate tensile strength and elongation to failure increased with increasing the extrusion ratio.Recycled specimens with the extrusion ratio of 40:1 showed higher ultimate tensile strength of 342.61 MPa and higher elongation to failure of 11.32%,compared with those of the cast specimen.展开更多
For monomer reactivity ratios study, the copolymerization of D,L-3-methylglycolide (MG) with glycolide (GA) or D,L-lactide (LA) was carried out in bulk to a certain low conversion in the presence of stannous octoate a...For monomer reactivity ratios study, the copolymerization of D,L-3-methylglycolide (MG) with glycolide (GA) or D,L-lactide (LA) was carried out in bulk to a certain low conversion in the presence of stannous octoate at 140 degrees C. The copolymer compositions were determined by H-1 NMR spectroscopy. The monomer reactivity ratios were evaluated by Fineman-Ross method, Kelen-Tudos method and linear least-squares method. The monomer reactivity ratios of D,L-3-methylglycolide and glycolide or D,L-lactide are r(mg)= 0.73, r(ga)= 1.47; r(mg)= 1.71, r(la)= 0.92, respectively.展开更多
Inherent drawbacks associated with drug-eluting stents have prompted the development of bioresorbable cardiovascular stents.Additive manufacturing(3-dimentional(3D)printing)has been widely applied in medical devices.I...Inherent drawbacks associated with drug-eluting stents have prompted the development of bioresorbable cardiovascular stents.Additive manufacturing(3-dimentional(3D)printing)has been widely applied in medical devices.In this study,we develop a novel screw extrusion-based 3D printing system with a new designed mini-screw extruder to fabricate stents.A stent with a zero Poisson’s ratio(ZPR)structure is designed,and a preliminary monofilament test is conducted to investigate appropriate fabrication parameters.3D-printed stents with different geometric structures are fabricated and analyzed by observation of the surface morphology.An evaluation of the mechanical properties and a preliminary biological evaluation of 3D-printed stents with different parameters are carried out.In conclusion,the screw extrusion-based 3D printing system shows potential for customizable stent fabrication.展开更多
Raman spectroscopy-based temperature sensing usually tracks the change of Raman wavenumber,linewidth and intensity,and has found very broad applications in characterizing the energy and charge transport in nanomateria...Raman spectroscopy-based temperature sensing usually tracks the change of Raman wavenumber,linewidth and intensity,and has found very broad applications in characterizing the energy and charge transport in nanomaterials over the last decade.The temperature coefficients of these Raman properties are highly material-dependent,and are subjected to local optical scattering influence.As a result,Raman-based temperature sensing usually suffers quite large uncertainties and has low sensitivity.Here,a novel method based on dual resonance Raman phenomenon is developed to precisely measure the absolute temperature rise of nanomaterial(nm WS_(2) film in this work)from 170 to 470 K.A 532 nm laser(2.33 eV photon energy)is used to conduct the Raman experiment.Its photon energy is very close to the excitonic transition energy of WS_(2) at temperatures close to room temperature.A parameter,termed resonance Raman ratio(R3)Ω=I_(A1g)/IE_(2g) is introduced to combine the temperature effects on resonance Raman scattering for the A_(1g) and E_(2g) modes.Ω has a change of more than two orders of magnitude from 177 to 477 K,and such change is independent of film thickness and local optical scattering.It is shown that when Ω is varied by 1%,the temperature probing sensitivity is 0.42 K and 1.16 K at low and high temperatures,respectively.Based on Ω,the in-plane thermal conductivity(k)of a∼25 nm-thick suspended WS_(2) film is measured using our energy transport state-resolved Raman(ET-Raman).k is found decreasing from 50.0 to 20.0 Wm^(−1) K^(−1) when temperature increases from 170 to 470 K.This agrees with previous experimental and theoretical results and the measurement data using our FET-Raman.The R3 technique provides a very robust and high-sensitivity method for temperature probing of nanomaterials and will have broad applications in nanoscale thermal transport characterization,non-destructive evaluation,and manufacturing monitoring.展开更多
文摘目的分析2型糖尿病患者25-羟维生素D[25(OH)D]水平,初步了解血清25(OH)D水平与2型糖尿病患者糖化血红蛋白(HbA1c)、胰岛功能等代谢指标的相关性。方法选择新乡市第一人民医院内分泌科2020年1月至2020年12月收治的459例2型糖尿病患者为研究对象。收集患者的临床资料,包括性别、年龄、血清25(OH)D、空腹胰岛素、C肽、HbA1c、空腹血糖、餐后血糖、尿微量白蛋白、尿白蛋白肌酐比值、血钙、血尿酸(UA)、三酰甘油(TG)、总胆固醇(TCH)、低密度脂蛋白(LDL)、高密度脂蛋白(HDL)等。根据血清25(OH)D水平将患者分为充足组[n=20,25(OH)D≥30μg·L^(-1)]、不足组[n=95,20μg·L^(-1)≤25(OH)D<30μg·L^(-1)]、缺乏组[n=231,10μg·L^(-1)≤25(OH)D<20μg·L^(-1)]、严重缺乏组[n=113,25(OH)D<10μg·L^(-1)]。比较4组患者各代谢指标的差异,采用Pearson相关分析25(OH)D与各代谢指标的相关性。结果2型糖尿病患者血清25(OH)D水平为3.00~46.59(15.75±0.35)μg·L^(-1),男性患者的血清25(OH)D水平显著高于女性患者(P<0.05)。2型糖尿病患者25(OH)D缺乏的患病率为74.9%(344/459),25(OH)D缺乏主要发生在1、2、3、4、11、12月份。不足组、缺乏组和严重缺乏组患者HbA1c显著高于充足组(P<0.05),缺乏组和严重缺乏组患者HbA1c显著高于不足组(P<0.05);缺乏组和严重缺乏组患者HbA1c比较差异无统计学意义(P>0.05)。充足组与不足组、缺乏组与严重缺乏组患者空腹血糖比较差异无统计学意义(P>0.05);缺乏组和严重缺乏组患者空腹血糖显著高于充足组、不足组(P<0.05)。充足组、不足组、缺乏组患者空腹胰岛素、尿微量白蛋白、日尿白蛋白总量、尿白蛋白肌酐比值比较差异无统计学意义(P>0.05);严重缺乏组患者空腹胰岛素显著低于充足组、不足组和缺乏组,尿微量白蛋白、日尿白蛋白总量、尿白蛋白肌酐比值显著高于充足组、不足组和缺乏组(P<0.05)。4组患者的稳态模型评估的胰岛素抵抗指数(HOMA-IR)、血清白蛋白、血肌酐、餐后1 h血糖、餐后2 h血糖、餐后3 h血糖、空腹C肽、餐后1 h C肽、餐后2 h C肽、餐后3 h C肽、TG、TCH、LDL、HDL、血UA、血钙比较差异均无统计学意义(P>0.05)。Pearson相关性分析结果显示,2型糖尿病患者血清25(OH)D水平与HbA1c、尿微量白蛋白、尿白蛋白肌酐比值呈负相关(r=-0.093、-0.166、-0.157,P<0.05),与空腹胰岛素呈正相关(r=0.089,P<0.05)。2型糖尿病患者血清25(OH)D水平与空腹血糖、HOMA-IR、血清白蛋白、血肌酐、餐后1 h血糖、餐后2 h血糖、餐后3 h血糖、空腹C肽、餐后1 h C肽、餐后2 h C肽、餐后3 h C肽、TG、TCH、LDL、HDL、血UA、血钙等无相关性(P>0.05)。结论2型糖尿病患者25(OH)D缺乏与不足普遍存在,女性患者缺乏更明显。2型糖尿病患者25(OH)D水平与空腹胰岛素呈正相关,与HbA1c、尿微量白蛋白、尿白蛋白肌酐比值呈负相关,25(OH)D缺乏的2型糖尿病患者主要分布在1、2、3、4、11、12月份。
文摘Aim: To investigate the relationship between 2D:4D and testosterone in men attending an infertility clinic and men drawn from the general population. Methods: Data on 2D:4D and testosterone from two samples were collected: (1) 43 men attending an infertility clinic, and (2) 51 men drawn from the general population without regard to fertility. Results: In sample (1) there were negative associations between 2D:4D and testicular function, and men with lower 2D:4D in their right compared to left hand had higher testosterone levels than men with higher 2D:4D in their right compared to left hand. Sample (2) showed no significant associations between 2D:4D or side differences in 2E>:4D and testosterone. Conclusion: Adult levels of testosterone may be related to aspects of 2D:4D in samples which contain men with compromised testicular function, but not in men from normative samples. Associations between 2D:4D and fertility-associated traits probably arise from early organisational effects of testosterone rather than from activational effects of current testosterone.
基金Projects(50674038, 50974048) supported by the National Natural Science Foundation of ChinaProject(200802140004) supported by Doctoral Fund of Ministry of Education of China
文摘A method for recycling AZ91D magnesium alloy scraps directly by hot extrusion was studied.Various microstructural analyses were performed using the techniques of optical microscopy,scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS).Microstructural observations revealed that all the recycled specimens consisted of fine grains due to the dynamic recrystallization.The main strengthening mechanism of the recycled specimen was grain refinement strengthening and homogeneous distribution of oxide precipitates.The interfaces of individual scraps of extruded materials were not identified when the scraps were extruded with the extrusion ratio of 40-1.Oxidation layers of the scraps were broken into pieces by high compressive and shear forces under the extrusion ratio of 40-1.The ultimate tensile strength and elongation to failure increased with increasing the extrusion ratio.Recycled specimens with the extrusion ratio of 40:1 showed higher ultimate tensile strength of 342.61 MPa and higher elongation to failure of 11.32%,compared with those of the cast specimen.
基金This work was supported by the Key Project of the National Natural Science Foundation of China!(59833 140).
文摘For monomer reactivity ratios study, the copolymerization of D,L-3-methylglycolide (MG) with glycolide (GA) or D,L-lactide (LA) was carried out in bulk to a certain low conversion in the presence of stannous octoate at 140 degrees C. The copolymer compositions were determined by H-1 NMR spectroscopy. The monomer reactivity ratios were evaluated by Fineman-Ross method, Kelen-Tudos method and linear least-squares method. The monomer reactivity ratios of D,L-3-methylglycolide and glycolide or D,L-lactide are r(mg)= 0.73, r(ga)= 1.47; r(mg)= 1.71, r(la)= 0.92, respectively.
基金funding support from the Beijing Municipal Natural Science Foundation,China(Z150001)supported by Beijing Anzhen Hospital.
文摘Inherent drawbacks associated with drug-eluting stents have prompted the development of bioresorbable cardiovascular stents.Additive manufacturing(3-dimentional(3D)printing)has been widely applied in medical devices.In this study,we develop a novel screw extrusion-based 3D printing system with a new designed mini-screw extruder to fabricate stents.A stent with a zero Poisson’s ratio(ZPR)structure is designed,and a preliminary monofilament test is conducted to investigate appropriate fabrication parameters.3D-printed stents with different geometric structures are fabricated and analyzed by observation of the surface morphology.An evaluation of the mechanical properties and a preliminary biological evaluation of 3D-printed stents with different parameters are carried out.In conclusion,the screw extrusion-based 3D printing system shows potential for customizable stent fabrication.
基金Support of this work by National Science Foundation(CBET1930866 and CMMI2032464 for X W)National Natural Science Foundation of China(No.52106220 for S X and No.51906161 for Y X)。
文摘Raman spectroscopy-based temperature sensing usually tracks the change of Raman wavenumber,linewidth and intensity,and has found very broad applications in characterizing the energy and charge transport in nanomaterials over the last decade.The temperature coefficients of these Raman properties are highly material-dependent,and are subjected to local optical scattering influence.As a result,Raman-based temperature sensing usually suffers quite large uncertainties and has low sensitivity.Here,a novel method based on dual resonance Raman phenomenon is developed to precisely measure the absolute temperature rise of nanomaterial(nm WS_(2) film in this work)from 170 to 470 K.A 532 nm laser(2.33 eV photon energy)is used to conduct the Raman experiment.Its photon energy is very close to the excitonic transition energy of WS_(2) at temperatures close to room temperature.A parameter,termed resonance Raman ratio(R3)Ω=I_(A1g)/IE_(2g) is introduced to combine the temperature effects on resonance Raman scattering for the A_(1g) and E_(2g) modes.Ω has a change of more than two orders of magnitude from 177 to 477 K,and such change is independent of film thickness and local optical scattering.It is shown that when Ω is varied by 1%,the temperature probing sensitivity is 0.42 K and 1.16 K at low and high temperatures,respectively.Based on Ω,the in-plane thermal conductivity(k)of a∼25 nm-thick suspended WS_(2) film is measured using our energy transport state-resolved Raman(ET-Raman).k is found decreasing from 50.0 to 20.0 Wm^(−1) K^(−1) when temperature increases from 170 to 470 K.This agrees with previous experimental and theoretical results and the measurement data using our FET-Raman.The R3 technique provides a very robust and high-sensitivity method for temperature probing of nanomaterials and will have broad applications in nanoscale thermal transport characterization,non-destructive evaluation,and manufacturing monitoring.
