Understanding the mesoscopic tensile fracture damage of rock is the basis of evaluating the deterioration process of mechanical properties of heat-damaged rock. For this, tensile tests of rocks under high-temperature ...Understanding the mesoscopic tensile fracture damage of rock is the basis of evaluating the deterioration process of mechanical properties of heat-damaged rock. For this, tensile tests of rocks under high-temperature treatment were conducted with a ϕ75 mm split Hopkinson tension bar (SHTB) to investigate the mesoscopic fracture and damage properties of rock. An improved scanning electron microscopy (SEM) experimental method was used to analyze the tensile fracture surfaces of rock samples. Qualitative and quantitative analyses were performed to assess evolution of mesoscopic damage of heat-damaged rock under tensile loading. A constitutive model describing the mesoscopic fractal damage under thermo-mechanical coupling was established. The results showed that the high temperatures significantly reduced the tensile strength and fracture surface roughness of the red sandstone. The three-dimensional (3D) reconstruction of the fracture surface of the samples that experienced tensile failure at 900 °C showed a flat surface. The standard deviation of elevation and slope angle of specimen fracture surface first increased and then decreased with increasing temperature. The threshold for brittle fracture of the heat-damaged red sandstone specimens was 600 °C. Beyond this threshold temperature, local ductile fracture occurred, resulting in plastic deformation of the fracture surface during tensile fracturing. With increase of temperature, the internal meso-structure of samples was strengthened slightly at first and then deteriorated gradually, which was consistent with the change of macroscopic mechanical properties of red sandstone. The mesoscopic characteristics, such as the number, mean side length, maximum area, porosity, and fractal dimension of crack, exhibited an initial decline, followed by a gradual increase. The development of microcracks in samples had significant influence on mesoscopic fractal dimension. The mesoscopic fractal characteristics were used to establish a mesoscopic fractal damage constitutive model for red sandstone, and the agreement between the theoretical and experimental results validated the proposed model.展开更多
目的系统评估乙型肝炎病毒核心抗体(hepatitis B virus core antibody,HBcAb)水平与慢性乙型肝炎(chronic hepatitis B,CHB)患者肝脏炎症及纤维化程度的相关性,以及HBcAb能否作为CHB患者抗病毒疗效的预测指标。方法检索PubMed、Embase、...目的系统评估乙型肝炎病毒核心抗体(hepatitis B virus core antibody,HBcAb)水平与慢性乙型肝炎(chronic hepatitis B,CHB)患者肝脏炎症及纤维化程度的相关性,以及HBcAb能否作为CHB患者抗病毒疗效的预测指标。方法检索PubMed、Embase、Web of Science、The Cochrane Library、中国知网、万方、维普数据库建库至2022年10月发表的有关HBcAb的文献。使用R4.2.1软件进行Meta分析,横断面研究文献质量评价参照美国卫生保健质量和研究机构(the Agency for Healthcare Research and Quality,AHRQ)提出的文献质量评价标准,队列研究质量评价参照纽卡斯尔-渥太华量表(Newcastle-Ottawa Scale,NOS)。采用剔除异质性最大或权重最大的文献进行敏感性分析。采用漏斗图和Egger检验进行发表偏倚评估。结果纳入30篇文献进行系统评价,其中21篇文献纳入Meta分析。结果表明HBcAb水平越高,CHB患者肝脏炎症程度(Summary r=0.39,95%CI:0.30~0.48,P<0.05)和肝脏纤维化程度(Summary r=0.33,95%CI:0.22~0.43,P<0.05)均越高。ALT基本正常的CHB患者中HBcAb较低的患者发生肝脏炎症(G2~G4)的风险较高(OR=2.02,95%CI:0.64~6.38,P<0.05)。干扰素(interferon,IFN)治疗的CHB患者基线HBcAb水平越高,HBsAg阴转率越高(MD=0.34,95%CI:-0.12~0.80,P<0.05)。核苷(酸)类似物[nucleos(t)ide analogues,NAs]和IFN治疗的CHB患者基线HBcAb水平越高,HBeAg血清学转换率(MD=0.37,95%CI:0.26~0.49,P<0.05)和HBV DNA病毒学应答率(MD=0.30,95%CI:0.16~0.44,P<0.05)均越高。IFN治疗的CHB患者停药时HBcAb水平越高,临床治愈后复发率越低(MD=-0.74,95%CI:-1.00~-0.48,P<0.05)。结论HBcAb水平越高,CHB患者肝脏炎症程度及纤维化程度越高。较高的HBcAb水平可作为预测NAs或IFN抗病毒疗效的指标之一。展开更多
Texture regulation is a prominent method to modify the mechanical properties and anisotropy of magnesium alloy.In this work,the Mg-1Al-0.3Ca-0.5Mn-0.2Gd(wt.%)alloy sheet with TD-tilted and circular texture was fabrica...Texture regulation is a prominent method to modify the mechanical properties and anisotropy of magnesium alloy.In this work,the Mg-1Al-0.3Ca-0.5Mn-0.2Gd(wt.%)alloy sheet with TD-tilted and circular texture was fabricated by unidirectional rolling(UR)and multidirectional rolling(MR)method,respectively.Unlike generating a strong in-plane mechanical anisotropy in conventional TD-tilted texture,the novel circular texture sample possessed a weak in-plane yield anisotropy.This can be rationalized by the similar proportion of soft grains with favorable orientation for basalslip and{10.12}tensile twinning during the uniaxial tension of circular-texture sample along different directions.Moreover,compared with the TD-tilted texture,the circular texture improved the elongation to failure both along the rolling direction(RD)and transverse direction(TD).By quasi-in-situ EBSD-assisted slip trace analysis,higher activation of basal slip was observed in the circular-texture sample during RD tension,contributing to its excellent ductility.When loading along the TD,the TD-tilted texture promoted the activation of{10.12}tensile twins significantly,thus providing nucleation sites for cracks and deteriorating the ductility.This research may shed new insights into the development of formable and ductile Mg alloy sheets by texture modification.展开更多
BACKGROUND Bladder cancer(BC)is the most common urological tumor.It has a high recur-rence rate,displays tutor heterogeneity,and resists chemotherapy.Furthermore,the long-term survival rate of BC patients has remained...BACKGROUND Bladder cancer(BC)is the most common urological tumor.It has a high recur-rence rate,displays tutor heterogeneity,and resists chemotherapy.Furthermore,the long-term survival rate of BC patients has remained unchanged for decades,which seriously affects the quality of patient survival.To improve the survival rate and prognosis of BC patients,it is necessary to explore the molecular mechanisms of BC development and progression and identify targets for treatment and intervention.Transmembrane 9 superfamily member 1(TM9SF1),also known as MP70 and HMP70,is a member of a family of nine transmembrane superfamily proteins,which was first identified in 1997.TM9SF1 can be expressed in BC,but its biological function and mechanism in BC are not clear.AIM To investigate the biological function and mechanism of TM9SF1 in BC.Overexpression of TM9SF1 increased the in vitro proliferation,migration,and invasion of BC cells by promoting the entry of BC cells into the G2/M phase.Silencing of TM9SF1 inhibited in vitro proliferation,migration,and invasion of BC cells and blocked BC cells in the G1 phase.CONCLUSION TM9SF1 may be an oncogene in BC.展开更多
基金supported by The National Natural Science Foundation of China(Grant Nos.12272411 and 42007259).
文摘Understanding the mesoscopic tensile fracture damage of rock is the basis of evaluating the deterioration process of mechanical properties of heat-damaged rock. For this, tensile tests of rocks under high-temperature treatment were conducted with a ϕ75 mm split Hopkinson tension bar (SHTB) to investigate the mesoscopic fracture and damage properties of rock. An improved scanning electron microscopy (SEM) experimental method was used to analyze the tensile fracture surfaces of rock samples. Qualitative and quantitative analyses were performed to assess evolution of mesoscopic damage of heat-damaged rock under tensile loading. A constitutive model describing the mesoscopic fractal damage under thermo-mechanical coupling was established. The results showed that the high temperatures significantly reduced the tensile strength and fracture surface roughness of the red sandstone. The three-dimensional (3D) reconstruction of the fracture surface of the samples that experienced tensile failure at 900 °C showed a flat surface. The standard deviation of elevation and slope angle of specimen fracture surface first increased and then decreased with increasing temperature. The threshold for brittle fracture of the heat-damaged red sandstone specimens was 600 °C. Beyond this threshold temperature, local ductile fracture occurred, resulting in plastic deformation of the fracture surface during tensile fracturing. With increase of temperature, the internal meso-structure of samples was strengthened slightly at first and then deteriorated gradually, which was consistent with the change of macroscopic mechanical properties of red sandstone. The mesoscopic characteristics, such as the number, mean side length, maximum area, porosity, and fractal dimension of crack, exhibited an initial decline, followed by a gradual increase. The development of microcracks in samples had significant influence on mesoscopic fractal dimension. The mesoscopic fractal characteristics were used to establish a mesoscopic fractal damage constitutive model for red sandstone, and the agreement between the theoretical and experimental results validated the proposed model.
文摘目的系统评估乙型肝炎病毒核心抗体(hepatitis B virus core antibody,HBcAb)水平与慢性乙型肝炎(chronic hepatitis B,CHB)患者肝脏炎症及纤维化程度的相关性,以及HBcAb能否作为CHB患者抗病毒疗效的预测指标。方法检索PubMed、Embase、Web of Science、The Cochrane Library、中国知网、万方、维普数据库建库至2022年10月发表的有关HBcAb的文献。使用R4.2.1软件进行Meta分析,横断面研究文献质量评价参照美国卫生保健质量和研究机构(the Agency for Healthcare Research and Quality,AHRQ)提出的文献质量评价标准,队列研究质量评价参照纽卡斯尔-渥太华量表(Newcastle-Ottawa Scale,NOS)。采用剔除异质性最大或权重最大的文献进行敏感性分析。采用漏斗图和Egger检验进行发表偏倚评估。结果纳入30篇文献进行系统评价,其中21篇文献纳入Meta分析。结果表明HBcAb水平越高,CHB患者肝脏炎症程度(Summary r=0.39,95%CI:0.30~0.48,P<0.05)和肝脏纤维化程度(Summary r=0.33,95%CI:0.22~0.43,P<0.05)均越高。ALT基本正常的CHB患者中HBcAb较低的患者发生肝脏炎症(G2~G4)的风险较高(OR=2.02,95%CI:0.64~6.38,P<0.05)。干扰素(interferon,IFN)治疗的CHB患者基线HBcAb水平越高,HBsAg阴转率越高(MD=0.34,95%CI:-0.12~0.80,P<0.05)。核苷(酸)类似物[nucleos(t)ide analogues,NAs]和IFN治疗的CHB患者基线HBcAb水平越高,HBeAg血清学转换率(MD=0.37,95%CI:0.26~0.49,P<0.05)和HBV DNA病毒学应答率(MD=0.30,95%CI:0.16~0.44,P<0.05)均越高。IFN治疗的CHB患者停药时HBcAb水平越高,临床治愈后复发率越低(MD=-0.74,95%CI:-1.00~-0.48,P<0.05)。结论HBcAb水平越高,CHB患者肝脏炎症程度及纤维化程度越高。较高的HBcAb水平可作为预测NAs或IFN抗病毒疗效的指标之一。
基金supports from The National Natural Science Foundation of China(nos.52222409,52074132,and U19A2084)The National Key Research and Development Program(no.2022YFE0122000)are greatly acknowledgedsupport from The Science and Technology Development Program of Jilin Province(no.20210301025GX).
文摘Texture regulation is a prominent method to modify the mechanical properties and anisotropy of magnesium alloy.In this work,the Mg-1Al-0.3Ca-0.5Mn-0.2Gd(wt.%)alloy sheet with TD-tilted and circular texture was fabricated by unidirectional rolling(UR)and multidirectional rolling(MR)method,respectively.Unlike generating a strong in-plane mechanical anisotropy in conventional TD-tilted texture,the novel circular texture sample possessed a weak in-plane yield anisotropy.This can be rationalized by the similar proportion of soft grains with favorable orientation for basalslip and{10.12}tensile twinning during the uniaxial tension of circular-texture sample along different directions.Moreover,compared with the TD-tilted texture,the circular texture improved the elongation to failure both along the rolling direction(RD)and transverse direction(TD).By quasi-in-situ EBSD-assisted slip trace analysis,higher activation of basal slip was observed in the circular-texture sample during RD tension,contributing to its excellent ductility.When loading along the TD,the TD-tilted texture promoted the activation of{10.12}tensile twins significantly,thus providing nucleation sites for cracks and deteriorating the ductility.This research may shed new insights into the development of formable and ductile Mg alloy sheets by texture modification.
基金Supported by National Natural Science Foundation of China,No.82260785.
文摘BACKGROUND Bladder cancer(BC)is the most common urological tumor.It has a high recur-rence rate,displays tutor heterogeneity,and resists chemotherapy.Furthermore,the long-term survival rate of BC patients has remained unchanged for decades,which seriously affects the quality of patient survival.To improve the survival rate and prognosis of BC patients,it is necessary to explore the molecular mechanisms of BC development and progression and identify targets for treatment and intervention.Transmembrane 9 superfamily member 1(TM9SF1),also known as MP70 and HMP70,is a member of a family of nine transmembrane superfamily proteins,which was first identified in 1997.TM9SF1 can be expressed in BC,but its biological function and mechanism in BC are not clear.AIM To investigate the biological function and mechanism of TM9SF1 in BC.Overexpression of TM9SF1 increased the in vitro proliferation,migration,and invasion of BC cells by promoting the entry of BC cells into the G2/M phase.Silencing of TM9SF1 inhibited in vitro proliferation,migration,and invasion of BC cells and blocked BC cells in the G1 phase.CONCLUSION TM9SF1 may be an oncogene in BC.
