By both the Charpy V-notched impact and the projectile tests, we here investigated the dynamic fracture behavior of a recently developed ultrastrong lightweight steel comprising a hierarchical martensitic matrix, disp...By both the Charpy V-notched impact and the projectile tests, we here investigated the dynamic fracture behavior of a recently developed ultrastrong lightweight steel comprising a hierarchical martensitic matrix, dispersed ultra-fine-retained austenite grains and oriented δ-ferrite lamellas, the latter being due to high Al and Si contents employed for low-density design. This steel shows a superior combination of specific ultimate tensile strength and impact toughness to other ultrastrong steels and has successfully arrested a real steel-cored bullet shot. These are attributed to the densely textured δ-ferrite lamellas that can deflect the propagating cracks until they are trapped and enclosed besides austenite-to-martensite transformation crack closure, leading to more energy consumed before failure. These results suggest a new pathway for toughening ultrastrong lightweight steels.展开更多
AIM:To evaluate the therapeutic effect of folic acid combined with decitabine on diabetic mice.METHODS:The diabetic model of db/db mice were randomly divided into model group,folic acid group,decitabine group,folic ac...AIM:To evaluate the therapeutic effect of folic acid combined with decitabine on diabetic mice.METHODS:The diabetic model of db/db mice were randomly divided into model group,folic acid group,decitabine group,folic acid combined with decitabine group,and C57 mice as normal control group.The density of retinal blood vessels and retinal thickness were detected by fundus photography and optical coherence tomography,respectively.Pathological changes of retina were observed by hematoxylin-eosin(HE)staining.The homocysteine(Hcy)in serum was detected by enzyme linked immunosorbent assay(ELISA).TdT-mediated dUTP nick-end labeling(TUNEL)was used to detect apoptosis in retinal tissue.Evans blue dye was used to detect the permeability of retinal blood vessels.The platelet endothelial cell adhesion molecule-1(CD31)and vascular endothelial growth factor receptor(VEGFR)protein were detected by Western blot.The 3-nitrotyrosine(3-NT)and 4-hydroxynonanine(4-HNE)were detected by immunohistochemistry.RESULTS:The density of retinal blood vessels,retinal thickness,retinal vascular permeability and the proportion of apoptotic cells of retinal tissue in the model group increased significantly than control group(P<0.05).The Hcy in serum and the levels of CD31,VEGFR,3-NT,and 4-HNE in retinal tissue increased significantly in the model group(P<0.01).Folic acid and decitabine both reversed these changes significantly,and the combination of the folic acid and decitabine worked best.CONCLUSION:The combination of folic acid and decitabine has a more significant protective effect on the retina in diabetic mice.展开更多
The high mobility group box 1(HMGB1),which belongs to the subfamily of HMG-1/-2,is a highly conserved single peptide chain consisting of 215 amino acid residues with a molecular weight of approximately 24894 Da.HMGB1 ...The high mobility group box 1(HMGB1),which belongs to the subfamily of HMG-1/-2,is a highly conserved single peptide chain consisting of 215 amino acid residues with a molecular weight of approximately 24894 Da.HMGB1 is a ubiquitous nuclear protein in mammals and plays a vital role in inflammatory diseases.Acute pancreatitis is one of the most common causes of acute abdominal pain with a poor prognosis.Acute pancreatitis is an acute inflammatory process of the pancreas(duration of less than six months),for which the severe form is called severe acute pancreatitis(SAP).More and more studies have shown that HMGB1 has a bidirectional effect in the pathogenesis of SAP.Extracellular HMGB1 can aggravate the pancreatic inflammatory process,whereas intracellular HMGB1 has a protective effect against pancreatitis.The mechanism of HMGB1 is multiple,mainly through the nuclear factor-κB pathway.Receptors for advanced glycation endproducts and toll-like receptors(TLR),especially TLR-2 and TLR-4,are two major types of receptors mediating the inflammatory process triggered by HMGB1 and may be also the main mediators in the pathogenesis of SAP.HMGB1 inhibitors,such as ethyl pyruvate,pyrrolidine dithiocarbamate and Scolopendra subspinipes mutilans,can decrease the level of extracellular HMGB1 and are the promising targets in the treatment of SAP.展开更多
目的探讨和描述2型糖尿病治疗药物的研究热点和近期进展情况。方法以Web of Science核心合集数据库中有关2型糖尿病及其治疗药物的文献为对象,借助可视化软件CiteSpaceV分析,获得关键词共现图谱和文献共被引图谱。结果现有文献研究表明...目的探讨和描述2型糖尿病治疗药物的研究热点和近期进展情况。方法以Web of Science核心合集数据库中有关2型糖尿病及其治疗药物的文献为对象,借助可视化软件CiteSpaceV分析,获得关键词共现图谱和文献共被引图谱。结果现有文献研究表明,具有新靶点和新作用机制的治疗药物如肠促胰素类药物、SGLT-2抑制剂、选择性过氧化物酶体增殖物激活受体调节剂等用于2型糖尿病的治疗。结论目前针对新靶点和新作用机制的2型糖尿病治疗药物研究已大量进入临床阶段,治疗效果显著\副作用小\多靶点的长效药物已成为研发重点。展开更多
The translucent GGAG:Ce/glass composites are prepared successfully by ball-milling,tableting,and pressureless sintering.The thickness of composites is about 400μm.The x-ray diffraction(XRD),differential scanning calo...The translucent GGAG:Ce/glass composites are prepared successfully by ball-milling,tableting,and pressureless sintering.The thickness of composites is about 400μm.The x-ray diffraction(XRD),differential scanning calorimetry(DSC),density of composite materials are measured and discussed systematically.The scanning electron microscopy(SEM)and energy dispersive spectrometer(EDS)elemental mapping are employed to analyze the particle size,the shape of powders,and the distribution of GGAG:Ce particles in the glass matrix,respectively.The decay time,ultraviolet,(UV),x-ray excitation luminescence spectra,and temperature spectra are studied.The results show that the composite materials have high light output,good thermostability,and short decay time.The method adopted in this work is an effective method to reduce the preparation time and cost of the sample.The ultralow afterglow indicates that the composite materials have an opportunity to be used for x-ray detection and imaging.展开更多
This study proposes three possible keel-surface layer combinations to implement a new type of thermally insulating decorative wall system.A set of 8 samples has been studied.In particular,through theoretical calculati...This study proposes three possible keel-surface layer combinations to implement a new type of thermally insulating decorative wall system.A set of 8 samples has been studied.In particular,through theoretical calculations,simulations,and experimental verification,the influence of different types of connecting structures on the overall thermal performance of the wall system has been determined.It has been found that a proper combination of these elements can meet existing energy-saving standards and effectively reduce the energy loss caused by thermal bridges due to the installation of steel keels at the edges of integrated wall panels.展开更多
Methylenecyclopropanes are among the most robust building blocks in synthetic chemistry,but the study on(difluoromethylene)-cyclopropanes is rather limited,because of the difficulty in the synthesis of these compounds...Methylenecyclopropanes are among the most robust building blocks in synthetic chemistry,but the study on(difluoromethylene)-cyclopropanes is rather limited,because of the difficulty in the synthesis of these compounds.Herein,we report the invention of a novel carbene precursor,(1-diazo-2,2,2-trifluoroethyl)dimethyl(phenyl)silane(1a)and its application in the synthesis of(difluoromethylene)cyclopropanes.The reaction proceeds through photocatalyzed[2+1]cyclization of readily available alkenes and diazo compound 1a followed by the work-up of the reaction through the elimination of silyl fluoride.Both aromatic and aliphatic alkenes are tolerated by the mild reaction conditions,affording various(difluoromethylene)cyclopropanes in 44%–82%yield(>30 examples).Gram scale reaction and diversified downstream transformations highlight the synthetic potential of this methodology.The experimental and DFT calculations suggest the involvement of triplet carbene intermediate.展开更多
Herein we report the first[4+1]cyclization-aromatization reaction of acylsilanes andα,β-unsaturated ketones.The unprecedented visible-light-induced reaction proceeded through mild conditions without addition of any ...Herein we report the first[4+1]cyclization-aromatization reaction of acylsilanes andα,β-unsaturated ketones.The unprecedented visible-light-induced reaction proceeded through mild conditions without addition of any catalyst or additive,affording a variety of furans with broad substrate scope and good functional-group tolerance.The synthetic utility of the method was demonstrated by various downstream transformations of the otherwise difficult-to-access sulfone-containing silyl furans.The mechanism study reveals that 1,4-diketones are not likely to be the intermediates of the reaction.展开更多
目的通过建立阿奇霉素的成人-儿童转化模型,为儿科临床用药提供指导性的建议,降低儿童用药风险,实现儿童临床个性化用药。方法查阅相关文献,利用成人的临床阿奇霉素口服给药试验的受试者生理参数结合阿奇霉素的药物特异参数,通过建立异...目的通过建立阿奇霉素的成人-儿童转化模型,为儿科临床用药提供指导性的建议,降低儿童用药风险,实现儿童临床个性化用药。方法查阅相关文献,利用成人的临床阿奇霉素口服给药试验的受试者生理参数结合阿奇霉素的药物特异参数,通过建立异速生长模型,生理药动学(physiologically based pharmacokinetic,PBPK)模型,根据文献提取的儿童个体口服阿奇霉素临床数据验证这2个模型的参数缩放公式的正确性。进一步利用这2种模型模拟出儿童相关药动学参数并计算出这些参数的相对偏差和相对标准误差。结果通过模拟发现2个模型得到的药动学参数cmax、tmax、AUC0-∞实测值接近,都在文献范围内,可认为2模型的参数转化公式正确。进一步计算参数的相对偏差和相对标准误差,成人-儿童PBPK预测模型的cmax、tmax、AUC0-∞的相对偏差和相对标准误差都比异速生长模型的小。结论阿奇霉素PBPK模型预测儿童药动学参数较异速生长模型要好。本研究所应用的口服用药成人-儿童模型特异性参数的缩放公式,经阿奇霉素验证成功,可以外推至其他药物,为其他口服给药的成人-儿童模型转化提供便利。展开更多
基金financial support from National Natural Science Foundation of China(Grant Nos.51831002,51904028 and 52233018),ChinaFundamental Research Funds for the Central Universities(Grant No.06500151),China.
文摘By both the Charpy V-notched impact and the projectile tests, we here investigated the dynamic fracture behavior of a recently developed ultrastrong lightweight steel comprising a hierarchical martensitic matrix, dispersed ultra-fine-retained austenite grains and oriented δ-ferrite lamellas, the latter being due to high Al and Si contents employed for low-density design. This steel shows a superior combination of specific ultimate tensile strength and impact toughness to other ultrastrong steels and has successfully arrested a real steel-cored bullet shot. These are attributed to the densely textured δ-ferrite lamellas that can deflect the propagating cracks until they are trapped and enclosed besides austenite-to-martensite transformation crack closure, leading to more energy consumed before failure. These results suggest a new pathway for toughening ultrastrong lightweight steels.
基金Supported by the Natural Science Foundation of Gansu Province(No.21JR7RA361).
文摘AIM:To evaluate the therapeutic effect of folic acid combined with decitabine on diabetic mice.METHODS:The diabetic model of db/db mice were randomly divided into model group,folic acid group,decitabine group,folic acid combined with decitabine group,and C57 mice as normal control group.The density of retinal blood vessels and retinal thickness were detected by fundus photography and optical coherence tomography,respectively.Pathological changes of retina were observed by hematoxylin-eosin(HE)staining.The homocysteine(Hcy)in serum was detected by enzyme linked immunosorbent assay(ELISA).TdT-mediated dUTP nick-end labeling(TUNEL)was used to detect apoptosis in retinal tissue.Evans blue dye was used to detect the permeability of retinal blood vessels.The platelet endothelial cell adhesion molecule-1(CD31)and vascular endothelial growth factor receptor(VEGFR)protein were detected by Western blot.The 3-nitrotyrosine(3-NT)and 4-hydroxynonanine(4-HNE)were detected by immunohistochemistry.RESULTS:The density of retinal blood vessels,retinal thickness,retinal vascular permeability and the proportion of apoptotic cells of retinal tissue in the model group increased significantly than control group(P<0.05).The Hcy in serum and the levels of CD31,VEGFR,3-NT,and 4-HNE in retinal tissue increased significantly in the model group(P<0.01).Folic acid and decitabine both reversed these changes significantly,and the combination of the folic acid and decitabine worked best.CONCLUSION:The combination of folic acid and decitabine has a more significant protective effect on the retina in diabetic mice.
基金Supported by National Science Foundation of China,No.81170438grant from Jiangsu Provincial Special Program of Medical Science,No.BL2012006
文摘The high mobility group box 1(HMGB1),which belongs to the subfamily of HMG-1/-2,is a highly conserved single peptide chain consisting of 215 amino acid residues with a molecular weight of approximately 24894 Da.HMGB1 is a ubiquitous nuclear protein in mammals and plays a vital role in inflammatory diseases.Acute pancreatitis is one of the most common causes of acute abdominal pain with a poor prognosis.Acute pancreatitis is an acute inflammatory process of the pancreas(duration of less than six months),for which the severe form is called severe acute pancreatitis(SAP).More and more studies have shown that HMGB1 has a bidirectional effect in the pathogenesis of SAP.Extracellular HMGB1 can aggravate the pancreatic inflammatory process,whereas intracellular HMGB1 has a protective effect against pancreatitis.The mechanism of HMGB1 is multiple,mainly through the nuclear factor-κB pathway.Receptors for advanced glycation endproducts and toll-like receptors(TLR),especially TLR-2 and TLR-4,are two major types of receptors mediating the inflammatory process triggered by HMGB1 and may be also the main mediators in the pathogenesis of SAP.HMGB1 inhibitors,such as ethyl pyruvate,pyrrolidine dithiocarbamate and Scolopendra subspinipes mutilans,can decrease the level of extracellular HMGB1 and are the promising targets in the treatment of SAP.
文摘目的探讨和描述2型糖尿病治疗药物的研究热点和近期进展情况。方法以Web of Science核心合集数据库中有关2型糖尿病及其治疗药物的文献为对象,借助可视化软件CiteSpaceV分析,获得关键词共现图谱和文献共被引图谱。结果现有文献研究表明,具有新靶点和新作用机制的治疗药物如肠促胰素类药物、SGLT-2抑制剂、选择性过氧化物酶体增殖物激活受体调节剂等用于2型糖尿病的治疗。结论目前针对新靶点和新作用机制的2型糖尿病治疗药物研究已大量进入临床阶段,治疗效果显著\副作用小\多靶点的长效药物已成为研发重点。
基金the National Natural Science Foundation of China(Grant Nos.11975220,51972291,11575170,and 11605194)。
文摘The translucent GGAG:Ce/glass composites are prepared successfully by ball-milling,tableting,and pressureless sintering.The thickness of composites is about 400μm.The x-ray diffraction(XRD),differential scanning calorimetry(DSC),density of composite materials are measured and discussed systematically.The scanning electron microscopy(SEM)and energy dispersive spectrometer(EDS)elemental mapping are employed to analyze the particle size,the shape of powders,and the distribution of GGAG:Ce particles in the glass matrix,respectively.The decay time,ultraviolet,(UV),x-ray excitation luminescence spectra,and temperature spectra are studied.The results show that the composite materials have high light output,good thermostability,and short decay time.The method adopted in this work is an effective method to reduce the preparation time and cost of the sample.The ultralow afterglow indicates that the composite materials have an opportunity to be used for x-ray detection and imaging.
基金The research content of this paper comes from the Urban and Rural Construction Science and Technology Project of Shandong Province,China,Subject No.2018-K9-07.
文摘This study proposes three possible keel-surface layer combinations to implement a new type of thermally insulating decorative wall system.A set of 8 samples has been studied.In particular,through theoretical calculations,simulations,and experimental verification,the influence of different types of connecting structures on the overall thermal performance of the wall system has been determined.It has been found that a proper combination of these elements can meet existing energy-saving standards and effectively reduce the energy loss caused by thermal bridges due to the installation of steel keels at the edges of integrated wall panels.
基金supported by the National Key Research and Development Program of China(2022YFA1506100)Shenzhen Science and Technology Program(JCYJ20220818100604009)Guangdong Basic and Applied Basic Research Foundation(2021A1515010105,2023A1515010601)。
文摘Methylenecyclopropanes are among the most robust building blocks in synthetic chemistry,but the study on(difluoromethylene)-cyclopropanes is rather limited,because of the difficulty in the synthesis of these compounds.Herein,we report the invention of a novel carbene precursor,(1-diazo-2,2,2-trifluoroethyl)dimethyl(phenyl)silane(1a)and its application in the synthesis of(difluoromethylene)cyclopropanes.The reaction proceeds through photocatalyzed[2+1]cyclization of readily available alkenes and diazo compound 1a followed by the work-up of the reaction through the elimination of silyl fluoride.Both aromatic and aliphatic alkenes are tolerated by the mild reaction conditions,affording various(difluoromethylene)cyclopropanes in 44%–82%yield(>30 examples).Gram scale reaction and diversified downstream transformations highlight the synthetic potential of this methodology.The experimental and DFT calculations suggest the involvement of triplet carbene intermediate.
基金the National Natural Science Foundation of China(grant no.21901191)the Fundamental Research Funds for the Central Universities,and Wuhan University for financial support.
文摘Herein we report the first[4+1]cyclization-aromatization reaction of acylsilanes andα,β-unsaturated ketones.The unprecedented visible-light-induced reaction proceeded through mild conditions without addition of any catalyst or additive,affording a variety of furans with broad substrate scope and good functional-group tolerance.The synthetic utility of the method was demonstrated by various downstream transformations of the otherwise difficult-to-access sulfone-containing silyl furans.The mechanism study reveals that 1,4-diketones are not likely to be the intermediates of the reaction.
文摘目的通过建立阿奇霉素的成人-儿童转化模型,为儿科临床用药提供指导性的建议,降低儿童用药风险,实现儿童临床个性化用药。方法查阅相关文献,利用成人的临床阿奇霉素口服给药试验的受试者生理参数结合阿奇霉素的药物特异参数,通过建立异速生长模型,生理药动学(physiologically based pharmacokinetic,PBPK)模型,根据文献提取的儿童个体口服阿奇霉素临床数据验证这2个模型的参数缩放公式的正确性。进一步利用这2种模型模拟出儿童相关药动学参数并计算出这些参数的相对偏差和相对标准误差。结果通过模拟发现2个模型得到的药动学参数cmax、tmax、AUC0-∞实测值接近,都在文献范围内,可认为2模型的参数转化公式正确。进一步计算参数的相对偏差和相对标准误差,成人-儿童PBPK预测模型的cmax、tmax、AUC0-∞的相对偏差和相对标准误差都比异速生长模型的小。结论阿奇霉素PBPK模型预测儿童药动学参数较异速生长模型要好。本研究所应用的口服用药成人-儿童模型特异性参数的缩放公式,经阿奇霉素验证成功,可以外推至其他药物,为其他口服给药的成人-儿童模型转化提供便利。
