[Objective]Traditional structural geology textbooks often provide outdated treatments of joints and veins,failing to reflect the significant advances made in the past three decades.This review seeks to address part of...[Objective]Traditional structural geology textbooks often provide outdated treatments of joints and veins,failing to reflect the significant advances made in the past three decades.This review seeks to address part of this gap by highlighting the significance of barren joints and veins in reconstructing both the directions and magnitudes of geological paleostresses.[Conclusion]Conjugate shear joints not only indicate the orientation of the three effective principal stresses but also imply differential stresses at least four times greater than the tensile strength of the brittle host rock.Exfoliation joints form under stress states ofσ_(1)≈σ_(2)>0>σ_(3),whereas polygonal columnar joints in sedimentary rocks reflectσ_(1)^(*)>>σ_(2)^(*)=σ_(3)^(*),allowing the tensile strength of rocks to be estimated.Tensile joints in brittle strong beds interlayered with ductile soft layers are primarily driven by tensile stresses transferred from interfacial shear stresses between the hard and soft layers,with joint saturation mainly controlled by tectonic strain.Under natural strain-rate conditions,the Weibull modulus and tensile strength of the strong layers,as well as the shear-flow strength of the ductile layers,can be inferred from the nonlinear relationship between joint spacing and bed thickness.Ladder-like orthogonal joints,which form under a stress state ofσ_(1)^(*)>>σ_(2)^(*)>σ_(3)^(*),divide strata into blocky units and,after weathering and erosion,give rise to characteristic castle-and tower-like landforms.Veins,as mineral-filled joints,provide spacing and thickness data that allow estimates of layer strain.Moreover,the nonlinear relationship between vein spacing and bed thickness permits quantification of the extent to which mineral precipitation restores the tensile strength of rock beds.The absence of ladder-like orthogonal veins is attributed to this strength recovery.[Significance]Collectively,these observations demonstrate the critical role of joints and veins in constraining both the magnitudes and orientations of geological paleostress fields.展开更多
Introduction Twisted arteries and veins disrupt normal blood flow and elevate the risk for clinical complications such as thrombosis,heart attack,stroke,and organ dysfunction.Veins should remain mechanically stable fo...Introduction Twisted arteries and veins disrupt normal blood flow and elevate the risk for clinical complications such as thrombosis,heart attack,stroke,and organ dysfunction.Veins should remain mechanically stable for normal function.However,compared to arteries,veins are more vulnerable to collapse because they are thin-walled and under lower lumen pressure.Twisted veins have been shown to occur with head turning or after inadvertent twist during various vascular surgeries.In vivo and cadaver studies have demonstrated that turning the head to one side can result in torsion and compression of the internal jugular vein and can compromise cranial drain-展开更多
Turn-milling which history dates from the end of the 20th century is one of the advanced metal cutting technologies. It could precisely machine hard materials as an alternative to turning for certain limitations. A se...Turn-milling which history dates from the end of the 20th century is one of the advanced metal cutting technologies. It could precisely machine hard materials as an alternative to turning for certain limitations. A series of orthogonal turn-milling surface veins experiments have been done on the turn-milling machining center by machining aluminum alloy,and then the nexus between the surface veins and the cutting regimes is studied. The mathematical model for surface vein direction angle is established,also the forming mechanics of surface vein direction is analyzed. Its variety regulation presents decreasing trend with as axial feed and cutter rotary speed increasing. For different eccentric distance of orthogonal turn-milling,the surface veins are different.展开更多
Introduction Tortuous veins are often seen in the retina,cerebrum,and human legs. Venous tortuosity may affect blood flow and the wall remodeling process,both of which are associated with venous diseases. It has been ...Introduction Tortuous veins are often seen in the retina,cerebrum,and human legs. Venous tortuosity may affect blood flow and the wall remodeling process,both of which are associated with venous diseases. It has been shown that tortuous or vari-展开更多
The western Tianshan high-pressure(HP) metamorphic belt represents the paleosubduction mélange of paleozoic south Tianshan ocean between the Yili-central Tianshan and Tarim plates. High-pressure veins are extensi...The western Tianshan high-pressure(HP) metamorphic belt represents the paleosubduction mélange of paleozoic south Tianshan ocean between the Yili-central Tianshan and Tarim plates. High-pressure veins are extensively developed in this HP belt. Compared with normal mid-ocean ridge basalt(N-MORB), the high-pressure veins and host rocks are enriched in light rare earth elements(LREE) and incompatible elements. But high-pressure veins show a larger variation than host rocks in total REE abundance. On the trace element spidergram, all the samples are enriched in incompatible elements and show strong positive Pb anomaly relative to N-MORB. The array tendency lines of plots of the HP rocks have apparent slopes on diagram of m(Sr) vs m(Sr)/m(Zr), m(Li) vs m(Li)/m(Y) and (m(Ce)) vs m(Ce)/m(Pb), which indicates that the enrichment in LREE and incompatible elements relative to N-MORB of the HP-metamorphic rocks from western Tianshan is not attributed to magma evolution process of the protolith. High field strength elements, such as Nb, Ta, Ti, Zr and Hf, do not show negative anomaly relative to N-MORB, which is dissimilar to that of island arc basalts. Therefore, the enrichment in LREE and incompatible elements of the HP rocks is not attributed to the enrichment of the source of the protolith. The mass ratios of Rb to Ba, Ce to Pb, Nb to U and Ta to U of high-pressure veins and host rocks are intermediate of mid-ocean ridge basalt or oceanic island basalt and continental crust. The fluids in western Tianshan paleosubduction zones are mixtures of two sources, dehydration or devolatilization of host rocks and of subducted sediments.展开更多
High-pressure(HP)veins were extensively developed in western Tianshan high-pressure(HP)metamorphic belt.The HP vein and host-rocks were analyzed by electronic microprobe to trace the origin of vein-forming fluids.Anal...High-pressure(HP)veins were extensively developed in western Tianshan high-pressure(HP)metamorphic belt.The HP vein and host-rocks were analyzed by electronic microprobe to trace the origin of vein-forming fluids.Analytical data show that the immediately adjacent host-rocks of the studied HP vein are eclogites and gradually turned into blueschist as the distance from the veins increases,which indicates that the vein-forming fluid was derived from adjacent host-rocks;the boundaries between the vein and the host-rocks are sharp,which indicates that the fracture of the host-rocks is brittle during the vein-forming process.It is suggested that this type of HP veins is precipitated from the liquid formed by the dehydration of the host-rocks during the prograde metamorphism from blueschist to eclogite facies,which results in hydrofracturing of the rocks and provides the space for the vein to precipitate.The width of the eclogite-facies host-rocks is usually 1-2 cm,which provides the direct evidence that the fluid flow is on centimeter-scale.展开更多
Hepatic arterio-venous shunt(HAVS) is a sort of usual pathologic phenomena accompanied by hepatocellular carcinoma,cirrhosis and so on,having significant influence on the therapy and prognosis of HCC.It is very import...Hepatic arterio-venous shunt(HAVS) is a sort of usual pathologic phenomena accompanied by hepatocellular carcinoma,cirrhosis and so on,having significant influence on the therapy and prognosis of HCC.It is very important to have an looking in-depth sight,making a prompt correct diagnosis and giving a proper active therapy for HAVS.The authors reviewed in detail concerning the caused mechanism,imaging-diagnosis and interventional procedures of HAVS so as to get an accordance on it.展开更多
Based on the basic geological features of Yixingzhai gold deposit, the geological features, classification and relation to mineralization of breccia pipes were discussed by surveying the xenoliths and breccia's mi...Based on the basic geological features of Yixingzhai gold deposit, the geological features, classification and relation to mineralization of breccia pipes were discussed by surveying the xenoliths and breccia's mineral composition, structure and construction, typical mineralization alteration phenomenon on field and microscopic anatomy in breccia pipes. And the ore-controlling mechanism and the formation mechanism of the blasting breccia pipes were investigated. The main conclusion shows that Hewan and Nanmenshan breccia pipes nearby the NW-striking deep fault are shaped earlier, belonging to the acidic siliceous ingredient production of ultra-hypabyssal magmatic in the late magma stage; Tietangdong and Nanmenshan breccia pipes that are shaped latter are the ultra-hypabyssal auriferous fluid production composed mainly of the skarn in the hydrothermal stage after the magma period. Both root in the unified deep magmatic chamber, belonging to differentiation derivatives at different stages in the deep magmatic chamber.展开更多
Objective Fumonisin B1(FB1)is an important mycotoxin in nature worldwide.The biomechanical properties of cells are closely related to their structure and function,and the cytoskeleton is the structural and functional ...Objective Fumonisin B1(FB1)is an important mycotoxin in nature worldwide.The biomechanical properties of cells are closely related to their structure and function,and the cytoskeleton is the structural and functional basis of cells motility,and therefore,from a biomechanical point of view,the purpose of this study is to investigate the effects of FB1 on the biomechanical properties,migration capacity and cytoskeletal structure of human umbilical vein endothelial cells(HUVECs),which may lay an experimental foundation for further exploration of the toxicity mechanism of fumonisin.Methods HUVECs were cultured and treated with different concentrations of FB1.Then,CCK-8 kit was used to detect the effect of FB1 on the survival rate.The osmotic fragility of the cells was measured after treatment with different osmotic pressures for30 min.The cell membrane fluidity was measured by fluorescence polarization method.The cell electrophoretic mobility was measured by cell electrophoretic apparatus.The migration capacity of the cells was observed by scratch repair assay.The changes of reactive oxygen species and cytoskeletal structure were observed by confocal laser scanning microscopy.Finally,the mRNA and protein relative expression levels of cytoskeletal binding proteins were detected by real-time PCR,Western blotting and confocal laser scanning.Results The results of CCK-8 showed that FB1 could significantly inhibit the proliferation of HUVECs in a dose-and time-dependent manner.After treatment of HUVECs with FB1,the hypotonic resistance of the cell,cell surface charge,cell membrane fluidity and migration capacity were all weakened,while reactive oxygen species were significantly increased and the cytoskeletal structure was significantly reorganized.Furthermore,RTPCR results showed that the mRNA relative expression levels of cytoskeletal binding proteins,exception of actin,were down-regulated after treated with FB1.Besides,Western blotting and statistical analysis based on fluorescence intensity of laser confocal microscopy confirmed theses changes in protein level.Conclusions FB1 can significantly affect the biomechanical properties and motility of HUVECs,which may be directly correlated to the remodel of F-actin cytoskeleton,as well as the relative expression changes of cytoskeletal binding proteins.It is significant for further exploring the toxicity mechanism of fumonisin.展开更多
Objective The study aimed to compare quality of saphenous vein(SV)grafts,wound complications,and clinical outcomes between endoscopic vein harvesting(EVH)technique and open vein harvesting(OVH)technique of coronary ar...Objective The study aimed to compare quality of saphenous vein(SV)grafts,wound complications,and clinical outcomes between endoscopic vein harvesting(EVH)technique and open vein harvesting(OVH)technique of coronary artery bypass graft(CABG)surgery.Methods One hundred patients with multi-vessel coronary disease underwent elective CABG using SV grafts were prospectively recruited and randomized into two groups.展开更多
Objective Vascular endothelial cells senescence is one of major risk factors for atherosclerotic diseases,which can be induced by endogenous peptides,such as angiotensin Ⅱ(Ang Ⅱ).However,the effect of chronic Ang Ⅱ...Objective Vascular endothelial cells senescence is one of major risk factors for atherosclerotic diseases,which can be induced by endogenous peptides,such as angiotensin Ⅱ(Ang Ⅱ).However,the effect of chronic Ang Ⅱ stimulation on endothelial senescence remains unknown.Therefore,this study aims to investigate the changes in morphology and function of human umbilical vein endothelial cells(HUVECs)in response to the chronic stimulation of Ang Ⅱ.展开更多
文摘[Objective]Traditional structural geology textbooks often provide outdated treatments of joints and veins,failing to reflect the significant advances made in the past three decades.This review seeks to address part of this gap by highlighting the significance of barren joints and veins in reconstructing both the directions and magnitudes of geological paleostresses.[Conclusion]Conjugate shear joints not only indicate the orientation of the three effective principal stresses but also imply differential stresses at least four times greater than the tensile strength of the brittle host rock.Exfoliation joints form under stress states ofσ_(1)≈σ_(2)>0>σ_(3),whereas polygonal columnar joints in sedimentary rocks reflectσ_(1)^(*)>>σ_(2)^(*)=σ_(3)^(*),allowing the tensile strength of rocks to be estimated.Tensile joints in brittle strong beds interlayered with ductile soft layers are primarily driven by tensile stresses transferred from interfacial shear stresses between the hard and soft layers,with joint saturation mainly controlled by tectonic strain.Under natural strain-rate conditions,the Weibull modulus and tensile strength of the strong layers,as well as the shear-flow strength of the ductile layers,can be inferred from the nonlinear relationship between joint spacing and bed thickness.Ladder-like orthogonal joints,which form under a stress state ofσ_(1)^(*)>>σ_(2)^(*)>σ_(3)^(*),divide strata into blocky units and,after weathering and erosion,give rise to characteristic castle-and tower-like landforms.Veins,as mineral-filled joints,provide spacing and thickness data that allow estimates of layer strain.Moreover,the nonlinear relationship between vein spacing and bed thickness permits quantification of the extent to which mineral precipitation restores the tensile strength of rock beds.The absence of ladder-like orthogonal veins is attributed to this strength recovery.[Significance]Collectively,these observations demonstrate the critical role of joints and veins in constraining both the magnitudes and orientations of geological paleostress fields.
基金supported by a CAREER award(0644646)from NSFa research grant (R01HL095852)and an MBRS-RISE fellowship(5R25GM060655-12)from the NIHa collaboration grant (11229202)from NNSF of China
文摘Introduction Twisted arteries and veins disrupt normal blood flow and elevate the risk for clinical complications such as thrombosis,heart attack,stroke,and organ dysfunction.Veins should remain mechanically stable for normal function.However,compared to arteries,veins are more vulnerable to collapse because they are thin-walled and under lower lumen pressure.Twisted veins have been shown to occur with head turning or after inadvertent twist during various vascular surgeries.In vivo and cadaver studies have demonstrated that turning the head to one side can result in torsion and compression of the internal jugular vein and can compromise cranial drain-
基金Sponsored by Doctoral Science Foundation of Shenyang Ligong University (BS04007)
文摘Turn-milling which history dates from the end of the 20th century is one of the advanced metal cutting technologies. It could precisely machine hard materials as an alternative to turning for certain limitations. A series of orthogonal turn-milling surface veins experiments have been done on the turn-milling machining center by machining aluminum alloy,and then the nexus between the surface veins and the cutting regimes is studied. The mathematical model for surface vein direction angle is established,also the forming mechanics of surface vein direction is analyzed. Its variety regulation presents decreasing trend with as axial feed and cutter rotary speed increasing. For different eccentric distance of orthogonal turn-milling,the surface veins are different.
基金supported by a CAREER award (0644646) from the National Science Foundationa research grant (R01HL095852)+1 种基金a MBRS-RISE fellowship (GM60655) from the National Institute of Health,USAa research grant (10928206) from the National Natural Science Foundation of China
文摘Introduction Tortuous veins are often seen in the retina,cerebrum,and human legs. Venous tortuosity may affect blood flow and the wall remodeling process,both of which are associated with venous diseases. It has been shown that tortuous or vari-
基金Preoject(2001CB409803) supported by the National Key Fundamental Research and Development Program of China
文摘The western Tianshan high-pressure(HP) metamorphic belt represents the paleosubduction mélange of paleozoic south Tianshan ocean between the Yili-central Tianshan and Tarim plates. High-pressure veins are extensively developed in this HP belt. Compared with normal mid-ocean ridge basalt(N-MORB), the high-pressure veins and host rocks are enriched in light rare earth elements(LREE) and incompatible elements. But high-pressure veins show a larger variation than host rocks in total REE abundance. On the trace element spidergram, all the samples are enriched in incompatible elements and show strong positive Pb anomaly relative to N-MORB. The array tendency lines of plots of the HP rocks have apparent slopes on diagram of m(Sr) vs m(Sr)/m(Zr), m(Li) vs m(Li)/m(Y) and (m(Ce)) vs m(Ce)/m(Pb), which indicates that the enrichment in LREE and incompatible elements relative to N-MORB of the HP-metamorphic rocks from western Tianshan is not attributed to magma evolution process of the protolith. High field strength elements, such as Nb, Ta, Ti, Zr and Hf, do not show negative anomaly relative to N-MORB, which is dissimilar to that of island arc basalts. Therefore, the enrichment in LREE and incompatible elements of the HP rocks is not attributed to the enrichment of the source of the protolith. The mass ratios of Rb to Ba, Ce to Pb, Nb to U and Ta to U of high-pressure veins and host rocks are intermediate of mid-ocean ridge basalt or oceanic island basalt and continental crust. The fluids in western Tianshan paleosubduction zones are mixtures of two sources, dehydration or devolatilization of host rocks and of subducted sediments.
基金Project(2001CB409803)supported by the Major State Basic Research Development Program of China
文摘High-pressure(HP)veins were extensively developed in western Tianshan high-pressure(HP)metamorphic belt.The HP vein and host-rocks were analyzed by electronic microprobe to trace the origin of vein-forming fluids.Analytical data show that the immediately adjacent host-rocks of the studied HP vein are eclogites and gradually turned into blueschist as the distance from the veins increases,which indicates that the vein-forming fluid was derived from adjacent host-rocks;the boundaries between the vein and the host-rocks are sharp,which indicates that the fracture of the host-rocks is brittle during the vein-forming process.It is suggested that this type of HP veins is precipitated from the liquid formed by the dehydration of the host-rocks during the prograde metamorphism from blueschist to eclogite facies,which results in hydrofracturing of the rocks and provides the space for the vein to precipitate.The width of the eclogite-facies host-rocks is usually 1-2 cm,which provides the direct evidence that the fluid flow is on centimeter-scale.
文摘Hepatic arterio-venous shunt(HAVS) is a sort of usual pathologic phenomena accompanied by hepatocellular carcinoma,cirrhosis and so on,having significant influence on the therapy and prognosis of HCC.It is very important to have an looking in-depth sight,making a prompt correct diagnosis and giving a proper active therapy for HAVS.The authors reviewed in detail concerning the caused mechanism,imaging-diagnosis and interventional procedures of HAVS so as to get an accordance on it.
基金Project(2007CB416608) supported by the Major State Basic Research Development Program of ChinaProject(2006BAB01B07) supported by the National Scientific Project for Tackcling Key Problems
文摘Based on the basic geological features of Yixingzhai gold deposit, the geological features, classification and relation to mineralization of breccia pipes were discussed by surveying the xenoliths and breccia's mineral composition, structure and construction, typical mineralization alteration phenomenon on field and microscopic anatomy in breccia pipes. And the ore-controlling mechanism and the formation mechanism of the blasting breccia pipes were investigated. The main conclusion shows that Hewan and Nanmenshan breccia pipes nearby the NW-striking deep fault are shaped earlier, belonging to the acidic siliceous ingredient production of ultra-hypabyssal magmatic in the late magma stage; Tietangdong and Nanmenshan breccia pipes that are shaped latter are the ultra-hypabyssal auriferous fluid production composed mainly of the skarn in the hydrothermal stage after the magma period. Both root in the unified deep magmatic chamber, belonging to differentiation derivatives at different stages in the deep magmatic chamber.
基金funded by the National Natural Science Foundation of China ( 31660258, 31771014,31860262,11762006)the Science and Technology Foundation of Guizhou Province ( 2019-2787,2018-1412, 2016-5676,2017-5718)+2 种基金the Science and Technology Innovative Talent Team of Guizhou Province ( 2015-4021)the 2011 Collaborative Innovation Program of Guizhou Province ( 2015-04 )the Cell and Gene Engineering Innovative Research Groups of Guizhou Province ( KY-2016-031)
文摘Objective Fumonisin B1(FB1)is an important mycotoxin in nature worldwide.The biomechanical properties of cells are closely related to their structure and function,and the cytoskeleton is the structural and functional basis of cells motility,and therefore,from a biomechanical point of view,the purpose of this study is to investigate the effects of FB1 on the biomechanical properties,migration capacity and cytoskeletal structure of human umbilical vein endothelial cells(HUVECs),which may lay an experimental foundation for further exploration of the toxicity mechanism of fumonisin.Methods HUVECs were cultured and treated with different concentrations of FB1.Then,CCK-8 kit was used to detect the effect of FB1 on the survival rate.The osmotic fragility of the cells was measured after treatment with different osmotic pressures for30 min.The cell membrane fluidity was measured by fluorescence polarization method.The cell electrophoretic mobility was measured by cell electrophoretic apparatus.The migration capacity of the cells was observed by scratch repair assay.The changes of reactive oxygen species and cytoskeletal structure were observed by confocal laser scanning microscopy.Finally,the mRNA and protein relative expression levels of cytoskeletal binding proteins were detected by real-time PCR,Western blotting and confocal laser scanning.Results The results of CCK-8 showed that FB1 could significantly inhibit the proliferation of HUVECs in a dose-and time-dependent manner.After treatment of HUVECs with FB1,the hypotonic resistance of the cell,cell surface charge,cell membrane fluidity and migration capacity were all weakened,while reactive oxygen species were significantly increased and the cytoskeletal structure was significantly reorganized.Furthermore,RTPCR results showed that the mRNA relative expression levels of cytoskeletal binding proteins,exception of actin,were down-regulated after treated with FB1.Besides,Western blotting and statistical analysis based on fluorescence intensity of laser confocal microscopy confirmed theses changes in protein level.Conclusions FB1 can significantly affect the biomechanical properties and motility of HUVECs,which may be directly correlated to the remodel of F-actin cytoskeleton,as well as the relative expression changes of cytoskeletal binding proteins.It is significant for further exploring the toxicity mechanism of fumonisin.
文摘Objective The study aimed to compare quality of saphenous vein(SV)grafts,wound complications,and clinical outcomes between endoscopic vein harvesting(EVH)technique and open vein harvesting(OVH)technique of coronary artery bypass graft(CABG)surgery.Methods One hundred patients with multi-vessel coronary disease underwent elective CABG using SV grafts were prospectively recruited and randomized into two groups.
文摘Objective Vascular endothelial cells senescence is one of major risk factors for atherosclerotic diseases,which can be induced by endogenous peptides,such as angiotensin Ⅱ(Ang Ⅱ).However,the effect of chronic Ang Ⅱ stimulation on endothelial senescence remains unknown.Therefore,this study aims to investigate the changes in morphology and function of human umbilical vein endothelial cells(HUVECs)in response to the chronic stimulation of Ang Ⅱ.
