目的研究胃超声结合身体质量指数(body mass index,BMI)用于指导行全麻剖宫产术术前禁食水时间的可行性。方法回顾性分析2012年1月—2022年12月在长春市妇幼保健院行全麻剖宫产术的450例孕产妇。根据孕产妇BMI增幅(△BMI)将其分为3组,A...目的研究胃超声结合身体质量指数(body mass index,BMI)用于指导行全麻剖宫产术术前禁食水时间的可行性。方法回顾性分析2012年1月—2022年12月在长春市妇幼保健院行全麻剖宫产术的450例孕产妇。根据孕产妇BMI增幅(△BMI)将其分为3组,A组△BMI<4 kg/m^(2),B组24 kg/m≤△BMI≤6 kg/m^(2),C组△BMI>6 kg/m^(2)。食用相同食物,比较3组胃排空能力及预后。结果A组禁食水时间为(6.85±1.53)h,B组禁食水时间为(7.49±1.46)h,C组禁食水时间为(7.84±1.24)h,3组禁食水时间比较,差异有统计学意义(P<0.05);3组Ⅱ、Ⅲ期及产前T1、T3、T4各时间点胃窦横截面积(cross-sectional area,CSA)比较,差异有统计学意义(P<0.05);3组妊娠结局[巨大儿、转入新生儿重症监护室(neonatal intensive care unit,NICU)、新生儿窒息]及口渴、饥饿感评分比较,差异有统计学意义(P<0.05);C组首次排气时间长于A组、B组,满意度评分低于A组与B组(P<0.05)。结论超声引导下胃窦部CSA可更精准地判定产妇的胃内容量,从而预判术前禁食水时间,改善妊娠结局。展开更多
Currently,the microwave absorbers usually suffer dreadful electromagnetic wave absorption(EMWA)performance damping at elevated temperature due to impedance mismatching induced by increased conduction loss.Consequently...Currently,the microwave absorbers usually suffer dreadful electromagnetic wave absorption(EMWA)performance damping at elevated temperature due to impedance mismatching induced by increased conduction loss.Consequently,the development of high-performance EMWA materials with good impedance matching and strong loss ability in wide temperature spectrum has emerged as a top priority.Herein,due to the high melting point,good electrical conductivity,excellent environmental stability,EM coupling effect,and abundant interfaces of titanium nitride(TiN)nanotubes,they were designed based on the controlling kinetic diffusion procedure and Ostwald ripening process.Benefiting from boosted heterogeneous interfaces between TiN nanotubes and polydimethylsiloxane(PDMS),enhanced polarization loss relaxations were created,which could not only improve the depletion efficiency of EMWA,but also contribute to the optimized impedance matching at elevated temperature.Therefore,the TiN nanotubes/PDMS composite showed excellent EMWA performances at varied temperature(298-573 K),while achieved an effective absorption bandwidth(EAB)value of 3.23 GHz and a minimum reflection loss(RLmin)value of−44.15 dB at 423 K.This study not only clarifies the relationship between dielectric loss capacity(conduction loss and polarization loss)and temperature,but also breaks new ground for EM absorbers in wide temperature spectrum based on interface engineering.展开更多
The corrosion rates of additive-manufactured Mg alloys are higher than their as-cast counterparts,possibly due to increased kinetics for the hydrogen evolution reaction on secondary phases,which may include oxide incl...The corrosion rates of additive-manufactured Mg alloys are higher than their as-cast counterparts,possibly due to increased kinetics for the hydrogen evolution reaction on secondary phases,which may include oxide inclusions.Scanning Kelvin Probe Force Microscopy demonstrated that MgO inclusions could act as cathodes for Mg corrosion,but their low conductivity likely precludes this.However,the density of state calculations through density functional theory using hybrid HSE06 functional revealed overlapping electronic states at the Mg/MgO interface,which facilitates electron transfers and participates in redox reactions.Subsequent determination of the hydrogen absorption energy at the Mg/MgO interface reveals it to be an excellent catalytic site,with HER being found to be a factor of 23x more efficient at the interface than on metallic Mg.The results not only support the plausibility of the Mg/MgO interface being an effective cathode to the adjacent anodic Mg matrix during corrosion but also contribute to the understanding of the enhanced cathodic activities observed during the anodic dissolution of magnesium.展开更多
Progress in the fast charging of high-capacity silicon monoxide(SiO)-based anode is currently hindered by insufficient conductivity and notable volume expansion.The construction of an interface conductive network effe...Progress in the fast charging of high-capacity silicon monoxide(SiO)-based anode is currently hindered by insufficient conductivity and notable volume expansion.The construction of an interface conductive network effectively addresses the aforementioned problems;however,the impact of its quality on lithium-ion transfer and structure durability is yet to be explored.Herein,the influence of an interface conductive network on ionic transport and mechanical stability under fast charging is explored for the first time.2D modeling simulation and Cryo-transmission electron microscopy precisely reveal the mitigation of interface polarization owing to a higher fraction of conductive inorganic species formation in bilayer solid electrolyte interphase is mainly responsible for a linear decrease in ionic diffusion energy barrier.Furthermore,atomic force microscopy and Raman shift exhibit substantial stress dissipation generated by a complete conductive network,which is critical to the linear reduction of electrode residual stress.This study provides insights into the rational design of optimized interface SiO-based anodes with reinforced fast-charging performance.展开更多
Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT...Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT aerogel structure shows nano-pore size(30-40 nm),high specific surface area(559 m^(2)g^(−1)),high void fraction(91.7%)and enhanced mechanical property:(1)the nano-pore size is beneficial for efficiently blocking thermal conduction and thermal convection via Knudsen effect(beneficial for infrared(IR)stealth);(2)the heterogeneous interface was beneficial for IR reflection(beneficial for IR stealth)and MWCNT polarization loss(beneficial for electromagnetic wave(EMW)attenuation);(3)the high void fraction was beneficial for enhancing thermal insulation(beneficial for IR stealth)and EMW impedance match(beneficial for EMW attenuation).Guided by the above theoretical design strategy,PVTMS@MWCNT nano-aerogel shows superior EMW absorption property(cover all Ku-band)and thermal IR stealth property(ΔT reached 60.7℃).Followed by a facial combination of the above nano-aerogel with graphene film of high electrical conductivity,an extremely high electromagnetic interference shielding material(66.5 dB,2.06 mm thickness)with superior absorption performance of an average absorption-to-reflection(A/R)coefficient ratio of 25.4 and a low reflection bandwidth of 4.1 GHz(A/R ratio more than 10)was experimentally obtained in this work.展开更多
It is well accepted that a lithiophilic interface can effectively regulate Li deposition behaviors,but the influence of the lithiophilic interface is gradually diminished upon continuous Li deposition that completely ...It is well accepted that a lithiophilic interface can effectively regulate Li deposition behaviors,but the influence of the lithiophilic interface is gradually diminished upon continuous Li deposition that completely isolates Li from the lithiophilic metals.Herein,we perform in-depth studies on the creation of dynamic alloy interfaces upon Li deposition,arising from the exceptionally high diffusion coefficient of Hg in the amalgam solid solution.As a comparison,other metals such as Au,Ag,and Zn have typical diffusion coefficients of 10-20 orders of magnitude lower than that of Hg in the similar solid solution phases.This difference induces compact Li deposition pattern with an amalgam substrate even with a high areal capacity of 55 mAh cm^(-2).This finding provides new insight into the rational design of Li anode substrate for the stable cycling of Li metal batteries.展开更多
目的:探讨体质量指数(body mass index,BMI)对乳腺癌患者治疗中位移误差的影响,为乳腺癌放射治疗中计划靶区外放边界提供数据支持。方法:回顾性分析本中心乳腺癌治疗的患者153例,利用CBCT获取摆位误差,并对数据进行挖掘,计算出两组因BM...目的:探讨体质量指数(body mass index,BMI)对乳腺癌患者治疗中位移误差的影响,为乳腺癌放射治疗中计划靶区外放边界提供数据支持。方法:回顾性分析本中心乳腺癌治疗的患者153例,利用CBCT获取摆位误差,并对数据进行挖掘,计算出两组因BMI的不同而导致的误差和PTV外放的差别。结果:从左乳和右乳的摆位误差分析计算得出:在考虑BMI情况下,左乳在腹背Z方向的摆位误差随BMI的增大而略有增大。右乳在Rx方向的摆位误差随BMI的增大而增大。左乳中,腹背Z方向外扩边界随BMI增大而逐渐增大。右乳中,头脚Y方向外扩边界随BMI增大而增大。结论:医师可根据乳腺癌的左右位置和BMI的大小来判断Mptv的扩大或者缩小,从而为患者提供更个性化精准化治疗。展开更多
目的调查武汉地区居民体质量指数(body mass index,BMI)连续变化情况,探讨BMI与血脂异常患病风险的剂量-反应关系,为该地区血脂异常防控提供科学依据。方法采用多阶段分层抽样法,于2022年抽取武汉市江岸区18岁及以上常住居民进行问卷调...目的调查武汉地区居民体质量指数(body mass index,BMI)连续变化情况,探讨BMI与血脂异常患病风险的剂量-反应关系,为该地区血脂异常防控提供科学依据。方法采用多阶段分层抽样法,于2022年抽取武汉市江岸区18岁及以上常住居民进行问卷调查、身体测量和实验室检测。应用非条件逐步Logistic回归和限制性立方样条模型分析BMI与血脂异常患病关联及剂量-反应关系。结果最终共纳入3173例样本,武汉市江岸区居民超重、肥胖的标化患病率分别为31.30%和8.95%。血脂异常、高总胆固醇(TC)、高甘油三酯(TG)血症、高低密度脂蛋白(LDL-C)血症和低高密度脂蛋白(HDL-C)血症的标化患病率分别为20.49%、2.60%、9.78%、3.17%和6.08%。超重(OR=1.118,95%CI:1.083~1.154)和肥胖(OR=1.181,95%CI:1.123~1.243)与血脂异常患病显著相关。男性(χ^(2)=6.67,P<0.05)、女性(χ^(2)=6.07,P<0.05)、18~<45岁(χ^(2)=13.40,P<0.05)和45~<65岁(χ^(2)=8.02,P<0.05)人群的BMI与血脂异常患病呈非线性剂量-反应关系,随BMI升高,血脂异常患病风险逐渐增加继而又趋于平缓。而65岁及以上(χ^(2)=0.18,P>0.05)人群的BMI与血脂异常患病呈线性剂量-反应关系。结论BMI的连续变化和血脂异常的患病风险呈正相关的剂量-反应关系。血脂异常的指标预警防控工作需关口前移,应注重中青年的血脂防控工作,并通过倡导减轻体质量、进行早期预防和控制等措施,降低血脂异常患病风险。展开更多
基金the National Nature Science Foundation of China(No.22305066).
文摘Currently,the microwave absorbers usually suffer dreadful electromagnetic wave absorption(EMWA)performance damping at elevated temperature due to impedance mismatching induced by increased conduction loss.Consequently,the development of high-performance EMWA materials with good impedance matching and strong loss ability in wide temperature spectrum has emerged as a top priority.Herein,due to the high melting point,good electrical conductivity,excellent environmental stability,EM coupling effect,and abundant interfaces of titanium nitride(TiN)nanotubes,they were designed based on the controlling kinetic diffusion procedure and Ostwald ripening process.Benefiting from boosted heterogeneous interfaces between TiN nanotubes and polydimethylsiloxane(PDMS),enhanced polarization loss relaxations were created,which could not only improve the depletion efficiency of EMWA,but also contribute to the optimized impedance matching at elevated temperature.Therefore,the TiN nanotubes/PDMS composite showed excellent EMWA performances at varied temperature(298-573 K),while achieved an effective absorption bandwidth(EAB)value of 3.23 GHz and a minimum reflection loss(RLmin)value of−44.15 dB at 423 K.This study not only clarifies the relationship between dielectric loss capacity(conduction loss and polarization loss)and temperature,but also breaks new ground for EM absorbers in wide temperature spectrum based on interface engineering.
基金Agency for Science,Technology and Research(A*STAR),under the RIE2020 Advanced Manufacturing and Engineering(AME)Programmatic Grant(Grant no.A18B1b0061)。
文摘The corrosion rates of additive-manufactured Mg alloys are higher than their as-cast counterparts,possibly due to increased kinetics for the hydrogen evolution reaction on secondary phases,which may include oxide inclusions.Scanning Kelvin Probe Force Microscopy demonstrated that MgO inclusions could act as cathodes for Mg corrosion,but their low conductivity likely precludes this.However,the density of state calculations through density functional theory using hybrid HSE06 functional revealed overlapping electronic states at the Mg/MgO interface,which facilitates electron transfers and participates in redox reactions.Subsequent determination of the hydrogen absorption energy at the Mg/MgO interface reveals it to be an excellent catalytic site,with HER being found to be a factor of 23x more efficient at the interface than on metallic Mg.The results not only support the plausibility of the Mg/MgO interface being an effective cathode to the adjacent anodic Mg matrix during corrosion but also contribute to the understanding of the enhanced cathodic activities observed during the anodic dissolution of magnesium.
基金the National Natural Science Foundation of China(Nos.22209095 and 22238004).
文摘Progress in the fast charging of high-capacity silicon monoxide(SiO)-based anode is currently hindered by insufficient conductivity and notable volume expansion.The construction of an interface conductive network effectively addresses the aforementioned problems;however,the impact of its quality on lithium-ion transfer and structure durability is yet to be explored.Herein,the influence of an interface conductive network on ionic transport and mechanical stability under fast charging is explored for the first time.2D modeling simulation and Cryo-transmission electron microscopy precisely reveal the mitigation of interface polarization owing to a higher fraction of conductive inorganic species formation in bilayer solid electrolyte interphase is mainly responsible for a linear decrease in ionic diffusion energy barrier.Furthermore,atomic force microscopy and Raman shift exhibit substantial stress dissipation generated by a complete conductive network,which is critical to the linear reduction of electrode residual stress.This study provides insights into the rational design of optimized interface SiO-based anodes with reinforced fast-charging performance.
基金the National Natural Science Foundation(No.52073187)NSAF Foundation(No.U2230202)for their financial support of this project+3 种基金National Natural Science Foundation(No.51721091)Programme of Introducing Talents of Discipline to Universities(No.B13040)State Key Laboratory of Polymer Materials Engineering(No.sklpme2022-2-03)support of China Scholarship Council
文摘Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT aerogel structure shows nano-pore size(30-40 nm),high specific surface area(559 m^(2)g^(−1)),high void fraction(91.7%)and enhanced mechanical property:(1)the nano-pore size is beneficial for efficiently blocking thermal conduction and thermal convection via Knudsen effect(beneficial for infrared(IR)stealth);(2)the heterogeneous interface was beneficial for IR reflection(beneficial for IR stealth)and MWCNT polarization loss(beneficial for electromagnetic wave(EMW)attenuation);(3)the high void fraction was beneficial for enhancing thermal insulation(beneficial for IR stealth)and EMW impedance match(beneficial for EMW attenuation).Guided by the above theoretical design strategy,PVTMS@MWCNT nano-aerogel shows superior EMW absorption property(cover all Ku-band)and thermal IR stealth property(ΔT reached 60.7℃).Followed by a facial combination of the above nano-aerogel with graphene film of high electrical conductivity,an extremely high electromagnetic interference shielding material(66.5 dB,2.06 mm thickness)with superior absorption performance of an average absorption-to-reflection(A/R)coefficient ratio of 25.4 and a low reflection bandwidth of 4.1 GHz(A/R ratio more than 10)was experimentally obtained in this work.
基金supported by the National Key Research and Development Program of China(2019YFA0205700)Scientific Research Projects of Colleges and Universities in Hebei Province(JZX2023004)+2 种基金Research Program of Local Science and Technology Development under the Guidance of Central(216Z4402G)support from Ministry of Science and Higher Education of Russian Federation(project FFSG-2022-0001(122111700046-3),"Laboratory of perspective electrode materials for chemical power sources")support from"Yuanguang"Scholar Program of Hebei University of Technology
文摘It is well accepted that a lithiophilic interface can effectively regulate Li deposition behaviors,but the influence of the lithiophilic interface is gradually diminished upon continuous Li deposition that completely isolates Li from the lithiophilic metals.Herein,we perform in-depth studies on the creation of dynamic alloy interfaces upon Li deposition,arising from the exceptionally high diffusion coefficient of Hg in the amalgam solid solution.As a comparison,other metals such as Au,Ag,and Zn have typical diffusion coefficients of 10-20 orders of magnitude lower than that of Hg in the similar solid solution phases.This difference induces compact Li deposition pattern with an amalgam substrate even with a high areal capacity of 55 mAh cm^(-2).This finding provides new insight into the rational design of Li anode substrate for the stable cycling of Li metal batteries.
文摘目的:探讨体质量指数(body mass index,BMI)对乳腺癌患者治疗中位移误差的影响,为乳腺癌放射治疗中计划靶区外放边界提供数据支持。方法:回顾性分析本中心乳腺癌治疗的患者153例,利用CBCT获取摆位误差,并对数据进行挖掘,计算出两组因BMI的不同而导致的误差和PTV外放的差别。结果:从左乳和右乳的摆位误差分析计算得出:在考虑BMI情况下,左乳在腹背Z方向的摆位误差随BMI的增大而略有增大。右乳在Rx方向的摆位误差随BMI的增大而增大。左乳中,腹背Z方向外扩边界随BMI增大而逐渐增大。右乳中,头脚Y方向外扩边界随BMI增大而增大。结论:医师可根据乳腺癌的左右位置和BMI的大小来判断Mptv的扩大或者缩小,从而为患者提供更个性化精准化治疗。
文摘目的调查武汉地区居民体质量指数(body mass index,BMI)连续变化情况,探讨BMI与血脂异常患病风险的剂量-反应关系,为该地区血脂异常防控提供科学依据。方法采用多阶段分层抽样法,于2022年抽取武汉市江岸区18岁及以上常住居民进行问卷调查、身体测量和实验室检测。应用非条件逐步Logistic回归和限制性立方样条模型分析BMI与血脂异常患病关联及剂量-反应关系。结果最终共纳入3173例样本,武汉市江岸区居民超重、肥胖的标化患病率分别为31.30%和8.95%。血脂异常、高总胆固醇(TC)、高甘油三酯(TG)血症、高低密度脂蛋白(LDL-C)血症和低高密度脂蛋白(HDL-C)血症的标化患病率分别为20.49%、2.60%、9.78%、3.17%和6.08%。超重(OR=1.118,95%CI:1.083~1.154)和肥胖(OR=1.181,95%CI:1.123~1.243)与血脂异常患病显著相关。男性(χ^(2)=6.67,P<0.05)、女性(χ^(2)=6.07,P<0.05)、18~<45岁(χ^(2)=13.40,P<0.05)和45~<65岁(χ^(2)=8.02,P<0.05)人群的BMI与血脂异常患病呈非线性剂量-反应关系,随BMI升高,血脂异常患病风险逐渐增加继而又趋于平缓。而65岁及以上(χ^(2)=0.18,P>0.05)人群的BMI与血脂异常患病呈线性剂量-反应关系。结论BMI的连续变化和血脂异常的患病风险呈正相关的剂量-反应关系。血脂异常的指标预警防控工作需关口前移,应注重中青年的血脂防控工作,并通过倡导减轻体质量、进行早期预防和控制等措施,降低血脂异常患病风险。
