The utilization of solar energy for hydrogen production via water splitting has garnered considerable attention in the realm of renewable energy.Si nanowires photocathodes own the advantages of effective photon absorp...The utilization of solar energy for hydrogen production via water splitting has garnered considerable attention in the realm of renewable energy.Si nanowires photocathodes own the advantages of effective photon absorption,non toxicity and industrial applicability.Nevertheless,the photoelectrocatalytic(PEC)performance of Si nanowires photocathodes is still limited by ineffective or deficient active sites on their surfaces.Here,we develop an efficient Si based photocathode modified with Al-porphyrin-based MOF(Al-PMOF),consisted of an earth-abundant metal containing Al(OH)O_(4) cluster bridged by 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin.The assembled Al-PMOF significantly enhances the photocurrent density of bare Si nanowires photocathodes,resulting in a twofold increase under equivalent conditions,alongside a positive shift of 200 mV in the onset potential of the Si/Al-PMOF photocathode.The improved PEC hydrogen evolution performance is ascribed to accelerate surface charge transfer of Si photocathode and provision of favorable active site for the hydrogen evolution reaction.This work provides insights into the fabrication of semiconductor/molecule catalyst hybrid photocathodes,thus facilitating the realization of high-efficiency PEC water splitting.展开更多
OBJECTIVE To explore the effect of ligustroflavone on ischemic brain injury in stroke rat and the under⁃lying mechanisms.METHODS A rat model of ischemic stroke was established by middle cerebral artery occlusion(MCAO)...OBJECTIVE To explore the effect of ligustroflavone on ischemic brain injury in stroke rat and the under⁃lying mechanisms.METHODS A rat model of ischemic stroke was established by middle cerebral artery occlusion(MCAO).Administration of ligustroflavone(10,30,60 mg·kg-1,ig)15 min before ischemia,after which neurological deficit score and infarct volume were detected by longa score and TTC stain.The cell viability and necrosis rate of hypoxia-cultured PC12 cells(O2/N2/CO2,1:94:5,8 h)were evaluated by MTS and LDH release rate.Flow cytometry further verified the mortality rate of PC12 cells.Necroptosis-associated proteins(RIPK1,RIPK3 and MLKL/p-MLKL)were detected by Western blotting.The interaction between RIPK3 and RIPK1 or MLKL were confirmed by immunoprecipitation.Operating Environ⁃ment(MOE)program demonstrated the possible combination of ligustroflavone with RIPK1,RIPK3 and MLKL.RESULTS Ischemic injury(increase in neurological deficit score and infarct volume)and upregulation of necroptosis-associated proteins were showed in rat MCAO model.Administration of ligustroflavone(30 mg·kg^-1,ig)evidently improved neurological func⁃tion,reduced infarct volume,and decreased the levels of necroptosis-associated proteins except the RIPK1.Consistently,hypoxia-cultured PC12 cells caused cellular injury(LDH release and necroposis)concomitant with up-regulation of necroptosis-associated proteins,and these phenomena were blocked in the presence of ligustroflavone(25μmol·L^-1)except the elevated RIPK1 levels.Using the Molecular Operating Environment(MOE)program,we identified RIPK1,RIPK3,and MLKL as potential targets of ligustroflavone.Further studies showed that the interaction between RIPK3 and RIPK1 or MLKL was significantly enhanced,which was blocked in the presence of ligustroflavone.CONCLUSION Ligus⁃troflavone protects rat brain from ischemic injury,and its beneficial effect is related to the prevention of necroptosis through a mechanism involving targeting RIPK1,RIPK3,and/or MLKL.展开更多
The microstructure,mechanical properties and corrosion resistance of Zr-30%Ta and Zr-25%Ta-5%Ti alloy prepared by spark plasma sintering(SPS)technology were investigated.The experimental results showed that the Zr-Ta-...The microstructure,mechanical properties and corrosion resistance of Zr-30%Ta and Zr-25%Ta-5%Ti alloy prepared by spark plasma sintering(SPS)technology were investigated.The experimental results showed that the Zr-Ta-Ti alloys made by the SPS processing have a low level of porosity with the relative density of 96%−98%.The analyses of XRD and TEM revealed that the Zr-30Ta alloy consists ofα+βphase,and the Zr-25Ta-5Ti alloy belongs to the nearβtype alloy containing a small amount ofαandωphases.With the addition of Ti,the elastic modulus of the alloys was decreased from(99.5±7.2)GPa for Zr-30Ta alloy to(73.6±6.3)GPa for Zr-25Ta-5Ti alloy.Furthermore,it is shown that,in comparison to CP-Ti and Ti-6Al-4V alloy,the Zr-Ta-Ti alloy produced in this work offers an improved corrosion resistance due to the more stable ZrO2 and Ta2O5 generated in the passivation film on the surface of the alloys.This study demonstrates that Zr-Ta-Ti alloys are a promising candidate of novel metallic biomaterials.展开更多
To evaluate the feasibility of using magnetic iron oxide nanoparticle as wild PTEN gene carrier for transfection in vitro to reverse cisplatin-resistance of A549/CDDP cells, A549/CDDP cells were transfected with the w...To evaluate the feasibility of using magnetic iron oxide nanoparticle as wild PTEN gene carrier for transfection in vitro to reverse cisplatin-resistance of A549/CDDP cells, A549/CDDP cells were transfected with the wild PTEN gene expression plasmid (pGFP-PTEN) by magnetic iron nanoparticle and lipo2000. The transfection efficiency was detected by fluorescence microscope and flow cytometer. The expression levels of PTEN mRNA and protein were detected by reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemistry analysis. The effect of PTEN transfection on cell cycle enhances the sensitivity of A549/CDDP to cisplatin and nanoparticle-mediated transfection has a higher efficiency than that of the liposome-mediated group. The apoptosis level was up-regulated in PTEN transfection group. The magnetic iron oxide nanoparticle could be used as one of the ideal gene carriers for PTEN gene delivery in vitro. PTEN can be an effective target for reversing cisplatin-resistance in lung cancer.展开更多
Human psychology and behavior have not only biological constraints,but also social constraints,which include cultural factors. The concept of "Positive Acceptance and Striving"is aunity of psychological acce...Human psychology and behavior have not only biological constraints,but also social constraints,which include cultural factors. The concept of "Positive Acceptance and Striving"is aunity of psychological acceptance and striving in the field of psychology research. It emphasizes on enhancing the self at the spiritual level rather than pursuit of the ultimate results,and it is one of the characteristics of the mental health. The traditional Chinese culture is the soul of"Positive Acceptance and Striving". From the traditional culture such as Confucianism,Taoism and Buddhism and the Chinese folk culture,this article review s the origin of"Positive Acceptance and Striving"in the traditional Chinese culture and explores the relation between cultural factors and psychological factors. It has practical significance in carrying forward the heritage of the traditional Chinese culture and developing a harmonious socity.展开更多
Magnesium alloys as medical implant materials necessitate a lower and adjustable corrosion rate for clinical applications.The microstructure and corrosion behavior of AZ31Mn-xEr(x=0.1,0.5,1.2)alloys were systematicall...Magnesium alloys as medical implant materials necessitate a lower and adjustable corrosion rate for clinical applications.The microstructure and corrosion behavior of AZ31Mn-xEr(x=0.1,0.5,1.2)alloys were systematically investigated using optical microscopy(OM),scanning electron microscopy(SEM),and X-ray photoelectron spectroscopy(XPS),combined with Tafel polarization and electrochemical impedance spectroscopy(EIS)analyses.The findings showed that the alloying element Er refined the grain structure during solidification by increasing the nucleation rate and forming a secondary phase of Al_(3)Er with Al.The Er and Mg in the matrix co-oxidize to form a dense MgO/Er_(2)O_(3)composite oxide,preventing the formation of loose magnesium hydroxide/basic magnesium carbonate.The trace alloying element Mn interacts with impurities Fe in the magnesium matrix to form an AlFeMn second phase,reducing micro-galvanic corrosion driving force.Electrochemical testing in a 3.5%NaCl solution demonstrated a marked reduction in corrosion rate from 10.46 mm/a(AZ 31 Mn alloy)to 0.44 mm/a(AZ31Mn-1.2Er alloy).This research offers a reference for searching for corrosion-resistant magnesium alloy and degradable medical magnesium alloy materials.展开更多
OBJECTIVE The Ca2+-activated Cl-channel(Ca CC)plays a crucial role in various physiological functions.Recent evidences suggest TMEM16A encodes CaC C in various cells,including endothelial cells.However,the role of TME...OBJECTIVE The Ca2+-activated Cl-channel(Ca CC)plays a crucial role in various physiological functions.Recent evidences suggest TMEM16A encodes CaC C in various cells,including endothelial cells.However,the role of TMEM16A in the vascular endothelial dysfunction in hypertension is unclear.METHODS In the study,RT-PCR,Western blotting,co-immunopricipitation,confocal imaging,patch-clamp,and endothelial-specific TMEM16A transgenic and knockout mice were employed.RESULTS We found that TMEM16A was expressed abundantly and functioned as Ca CC in endothelial cells.AngiotensinⅡ(AngⅡ)induced endothelial dysfunction with an increase in TMEM16A expression,which was alleviated by TMEM16A inhibitor.Further studies revealed that TMEM16A endothelial-specific knockout significantly lowered the blood pressure and ameliorated endothelial dysfunction in AngⅡ-induced hypertension,whereas,TMEM16A endothelial-specific overexpression showed the opposite effects.These results were related to the increased reactive oxygen species(ROS)generation,NADPH oxidase activation,and Nox2,p22phox expression facilitated by TMEM16A upon AngⅡ-induced hypertensive challenges.Moreover,TMEM16A directly interacted with Nox2 monomer and reduced the degradation of Nox2 through the proteasome-dependent endoplasmic recticulum-associated degradation pathway.TMEM16A also potentiated the translocation of p47phox and p67phox from cytosol to cell membrane and the subsequent interaction with Nox2.CONCLUSION Our results demonstrated that TMEM16A,as Ca CC,is a positive regulator of ROS generation via upregulating the activation of Nox2 NADPH oxidase in the vascular endothelium,and therefore facilitates endothelial dysfunction and hypertension.Modification of TMEM16A may be a novel therapeutic strategy for endothelial dysfunction-associated cardiovascular diseases.展开更多
基金Project(22078368)supported by the National Natural Science Foundation of China。
文摘The utilization of solar energy for hydrogen production via water splitting has garnered considerable attention in the realm of renewable energy.Si nanowires photocathodes own the advantages of effective photon absorption,non toxicity and industrial applicability.Nevertheless,the photoelectrocatalytic(PEC)performance of Si nanowires photocathodes is still limited by ineffective or deficient active sites on their surfaces.Here,we develop an efficient Si based photocathode modified with Al-porphyrin-based MOF(Al-PMOF),consisted of an earth-abundant metal containing Al(OH)O_(4) cluster bridged by 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin.The assembled Al-PMOF significantly enhances the photocurrent density of bare Si nanowires photocathodes,resulting in a twofold increase under equivalent conditions,alongside a positive shift of 200 mV in the onset potential of the Si/Al-PMOF photocathode.The improved PEC hydrogen evolution performance is ascribed to accelerate surface charge transfer of Si photocathode and provision of favorable active site for the hydrogen evolution reaction.This work provides insights into the fabrication of semiconductor/molecule catalyst hybrid photocathodes,thus facilitating the realization of high-efficiency PEC water splitting.
基金National Natural Science Foundation of China(8157343081872873)Hunan Provincial Natural Science Foundation of China(2015JJ2156)
文摘OBJECTIVE To explore the effect of ligustroflavone on ischemic brain injury in stroke rat and the under⁃lying mechanisms.METHODS A rat model of ischemic stroke was established by middle cerebral artery occlusion(MCAO).Administration of ligustroflavone(10,30,60 mg·kg-1,ig)15 min before ischemia,after which neurological deficit score and infarct volume were detected by longa score and TTC stain.The cell viability and necrosis rate of hypoxia-cultured PC12 cells(O2/N2/CO2,1:94:5,8 h)were evaluated by MTS and LDH release rate.Flow cytometry further verified the mortality rate of PC12 cells.Necroptosis-associated proteins(RIPK1,RIPK3 and MLKL/p-MLKL)were detected by Western blotting.The interaction between RIPK3 and RIPK1 or MLKL were confirmed by immunoprecipitation.Operating Environ⁃ment(MOE)program demonstrated the possible combination of ligustroflavone with RIPK1,RIPK3 and MLKL.RESULTS Ischemic injury(increase in neurological deficit score and infarct volume)and upregulation of necroptosis-associated proteins were showed in rat MCAO model.Administration of ligustroflavone(30 mg·kg^-1,ig)evidently improved neurological func⁃tion,reduced infarct volume,and decreased the levels of necroptosis-associated proteins except the RIPK1.Consistently,hypoxia-cultured PC12 cells caused cellular injury(LDH release and necroposis)concomitant with up-regulation of necroptosis-associated proteins,and these phenomena were blocked in the presence of ligustroflavone(25μmol·L^-1)except the elevated RIPK1 levels.Using the Molecular Operating Environment(MOE)program,we identified RIPK1,RIPK3,and MLKL as potential targets of ligustroflavone.Further studies showed that the interaction between RIPK3 and RIPK1 or MLKL was significantly enhanced,which was blocked in the presence of ligustroflavone.CONCLUSION Ligus⁃troflavone protects rat brain from ischemic injury,and its beneficial effect is related to the prevention of necroptosis through a mechanism involving targeting RIPK1,RIPK3,and/or MLKL.
基金Project(51404302)supported by the National Natural Science Foundation of ChinaProject(QJ2018003A)supported by the Youth Scientific Research Foundation of the Central South University of Forestry and Technology,China。
文摘The microstructure,mechanical properties and corrosion resistance of Zr-30%Ta and Zr-25%Ta-5%Ti alloy prepared by spark plasma sintering(SPS)technology were investigated.The experimental results showed that the Zr-Ta-Ti alloys made by the SPS processing have a low level of porosity with the relative density of 96%−98%.The analyses of XRD and TEM revealed that the Zr-30Ta alloy consists ofα+βphase,and the Zr-25Ta-5Ti alloy belongs to the nearβtype alloy containing a small amount ofαandωphases.With the addition of Ti,the elastic modulus of the alloys was decreased from(99.5±7.2)GPa for Zr-30Ta alloy to(73.6±6.3)GPa for Zr-25Ta-5Ti alloy.Furthermore,it is shown that,in comparison to CP-Ti and Ti-6Al-4V alloy,the Zr-Ta-Ti alloy produced in this work offers an improved corrosion resistance due to the more stable ZrO2 and Ta2O5 generated in the passivation film on the surface of the alloys.This study demonstrates that Zr-Ta-Ti alloys are a promising candidate of novel metallic biomaterials.
基金Project(07JJ3055)supported by the Natural Science Foundation of Hunan Province,China
文摘To evaluate the feasibility of using magnetic iron oxide nanoparticle as wild PTEN gene carrier for transfection in vitro to reverse cisplatin-resistance of A549/CDDP cells, A549/CDDP cells were transfected with the wild PTEN gene expression plasmid (pGFP-PTEN) by magnetic iron nanoparticle and lipo2000. The transfection efficiency was detected by fluorescence microscope and flow cytometer. The expression levels of PTEN mRNA and protein were detected by reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemistry analysis. The effect of PTEN transfection on cell cycle enhances the sensitivity of A549/CDDP to cisplatin and nanoparticle-mediated transfection has a higher efficiency than that of the liposome-mediated group. The apoptosis level was up-regulated in PTEN transfection group. The magnetic iron oxide nanoparticle could be used as one of the ideal gene carriers for PTEN gene delivery in vitro. PTEN can be an effective target for reversing cisplatin-resistance in lung cancer.
基金the initial result of the Social Science Fund Project of Hunan Province in 2011-The study of ESP Students Assistant Mechanism Based on Positive Psychology(11B15)
文摘Human psychology and behavior have not only biological constraints,but also social constraints,which include cultural factors. The concept of "Positive Acceptance and Striving"is aunity of psychological acceptance and striving in the field of psychology research. It emphasizes on enhancing the self at the spiritual level rather than pursuit of the ultimate results,and it is one of the characteristics of the mental health. The traditional Chinese culture is the soul of"Positive Acceptance and Striving". From the traditional culture such as Confucianism,Taoism and Buddhism and the Chinese folk culture,this article review s the origin of"Positive Acceptance and Striving"in the traditional Chinese culture and explores the relation between cultural factors and psychological factors. It has practical significance in carrying forward the heritage of the traditional Chinese culture and developing a harmonious socity.
基金Projects(82171030,81870678)supported by the National Natural Science Foundation of China。
文摘Magnesium alloys as medical implant materials necessitate a lower and adjustable corrosion rate for clinical applications.The microstructure and corrosion behavior of AZ31Mn-xEr(x=0.1,0.5,1.2)alloys were systematically investigated using optical microscopy(OM),scanning electron microscopy(SEM),and X-ray photoelectron spectroscopy(XPS),combined with Tafel polarization and electrochemical impedance spectroscopy(EIS)analyses.The findings showed that the alloying element Er refined the grain structure during solidification by increasing the nucleation rate and forming a secondary phase of Al_(3)Er with Al.The Er and Mg in the matrix co-oxidize to form a dense MgO/Er_(2)O_(3)composite oxide,preventing the formation of loose magnesium hydroxide/basic magnesium carbonate.The trace alloying element Mn interacts with impurities Fe in the magnesium matrix to form an AlFeMn second phase,reducing micro-galvanic corrosion driving force.Electrochemical testing in a 3.5%NaCl solution demonstrated a marked reduction in corrosion rate from 10.46 mm/a(AZ 31 Mn alloy)to 0.44 mm/a(AZ31Mn-1.2Er alloy).This research offers a reference for searching for corrosion-resistant magnesium alloy and degradable medical magnesium alloy materials.
基金The project supported by National Natural Science Foundation of China(81230082,81302771,81525025,81573422,81500226)Natural Science Foundation of Guangdong Province(2014A030313087)by Science and Technology program of Guangzhou City(201607010255)
文摘OBJECTIVE The Ca2+-activated Cl-channel(Ca CC)plays a crucial role in various physiological functions.Recent evidences suggest TMEM16A encodes CaC C in various cells,including endothelial cells.However,the role of TMEM16A in the vascular endothelial dysfunction in hypertension is unclear.METHODS In the study,RT-PCR,Western blotting,co-immunopricipitation,confocal imaging,patch-clamp,and endothelial-specific TMEM16A transgenic and knockout mice were employed.RESULTS We found that TMEM16A was expressed abundantly and functioned as Ca CC in endothelial cells.AngiotensinⅡ(AngⅡ)induced endothelial dysfunction with an increase in TMEM16A expression,which was alleviated by TMEM16A inhibitor.Further studies revealed that TMEM16A endothelial-specific knockout significantly lowered the blood pressure and ameliorated endothelial dysfunction in AngⅡ-induced hypertension,whereas,TMEM16A endothelial-specific overexpression showed the opposite effects.These results were related to the increased reactive oxygen species(ROS)generation,NADPH oxidase activation,and Nox2,p22phox expression facilitated by TMEM16A upon AngⅡ-induced hypertensive challenges.Moreover,TMEM16A directly interacted with Nox2 monomer and reduced the degradation of Nox2 through the proteasome-dependent endoplasmic recticulum-associated degradation pathway.TMEM16A also potentiated the translocation of p47phox and p67phox from cytosol to cell membrane and the subsequent interaction with Nox2.CONCLUSION Our results demonstrated that TMEM16A,as Ca CC,is a positive regulator of ROS generation via upregulating the activation of Nox2 NADPH oxidase in the vascular endothelium,and therefore facilitates endothelial dysfunction and hypertension.Modification of TMEM16A may be a novel therapeutic strategy for endothelial dysfunction-associated cardiovascular diseases.
