·AIM:To evaluate the role of internal limiting membrane(ILM)peeling in preventing secondary epiretinal membrane(ERM)formation in pars plana vitrectomy(PPV)for proliferative diabetic retinopathy(PDR).·METHODS...·AIM:To evaluate the role of internal limiting membrane(ILM)peeling in preventing secondary epiretinal membrane(ERM)formation in pars plana vitrectomy(PPV)for proliferative diabetic retinopathy(PDR).·METHODS:This retrospective study analyzed the medical records of patients who underwent PPV for PDR and were followed up for minimum 3 mo.ILM peeling was performed based on the intraoperative surgeons’judgments.ERM was assessed by optical coherence tomography photography.The relationship between ILM peeling and postoperative ERM was analyzed.·RESULTS:In total,212 eyes from 197 patients were included in this study.The incidence of secondary ERM in the ILM non-peeling group was significantly higher than that in the ILM peeling group(37.0%vs 14.0%;P<0.001).Multivariate logistical regression revealed that ILM peeling was highly associated with the prevention of secondary ERM development[odds ratio 0.38;95%confidence interval0.17-0.86;P<0.05].·CONCLUSION:ILM peeling during PPV for PDRs can effectively reduce the incidence of secondary ERM development and is worth consideration by vitreoretinal surgeons.展开更多
A zeolitic imidazolate hybrid membrane(Co-IM-mIM) containing two imidazolate ligands deposited on a macroporous α-alumina support was prepared by pre-depositing and secondary growth technique. XRD, TGA and SEM charac...A zeolitic imidazolate hybrid membrane(Co-IM-mIM) containing two imidazolate ligands deposited on a macroporous α-alumina support was prepared by pre-depositing and secondary growth technique. XRD, TGA and SEM characterizations demonstrate that a stable and thin, but dense and pure-phase Co-IM-mIM membrane can be obtained on the macroporous-alumina discs in Teflon-lined autoclave at 120 °C after pre-depositing by dip-coating at room temperature. No visible cracks, pinholes or other defects were observed on the membrane layer. The gas separation studies of Co-IM-mIM membrane were carried out at 25 °C and 1×10~5 Pa, showing ideal selectivity of 6.95, 5.25, 3.40 for H_2/CO_2, H_2/N_2 and H_2/CH_4, respectively, and a permeance of 17.37× 10^(-6) mol/(m^2·s·Pa) for H_2. The influence of temperature and trans-membrane pressure on hydrogen separation and permeation was also carried out. The gas permeation and selectivity demonstrate that this membrane may have potential applications for efficient H_2 separation.展开更多
High quality A-type zeolite membranes, with enlarged area over 70 cm2, were successfully synthesized on a tubular a-Al2O3 support by applying the vacuum seeding method.
The synthesis of a continuous IMF zeolite membrane was fabricated on tubular substrates by seeded growth for the first time. The straight channels of IMF zeolite with diameters of 0.53–0.59 nm are distinguishable for...The synthesis of a continuous IMF zeolite membrane was fabricated on tubular substrates by seeded growth for the first time. The straight channels of IMF zeolite with diameters of 0.53–0.59 nm are distinguishable for p-xylene from o-xylene molecules. Pure IMF-phase high-silica IM-5 zeolite seeds with uniform and fine crystal size were fabricated by a new sonication-assisted aging process. The seeds were coated on the support by dipcoating and induced the formation of continuous membrane. Separation performance in p-/o-xylene mixture was investigated at various temperature and pressure. The typical IM-5zeolite membrane had p-/o-xylene separation factor of 3.7. Our results suggest that IM-5 zeolite is a potentially good membrane material for the separation of xylene mixtures.展开更多
Cotton(Gossypium hirsutum)fibers are elongated single cells that rapidly accumulate cellulose during secondary cell wall(SCW)thickening,which requires cellulose synthase complex(CSC)activity.Here,we describe the CSC-i...Cotton(Gossypium hirsutum)fibers are elongated single cells that rapidly accumulate cellulose during secondary cell wall(SCW)thickening,which requires cellulose synthase complex(CSC)activity.Here,we describe the CSC-interacting factor CASPARIAN STRIP MEMBRANE DOMAIN-LIKE1(GhCASPL1),which contributes to SCW thickening by influencing CSC stability on the plasma membrane.GhCASPL1 is preferentially expressed in fiber cells during SCW biosynthesis and encodes a MARVEL domain protein.The ghcaspl1 ghcaspl2 mutant exhibited reduced plant height and produced mature fibers with fewer natural twists,lower tensile strength,and a thinner SCW compared to the wild type.Similarly,the Arabidopsis(Arabidopsis thaliana)caspl1 caspl2 double mutant showed a lower cellulose content and thinner cell walls in the stem vasculature than the wild type but normal plant morphology.Introducing the cotton gene GhCASPL1 successfully restored the reduced cellulose content of the Arabidopsis caspl1 caspl2 mutant.Detergent treatments,ultracentrifugation assays,and enzymatic assays showed that the CSC in the ghcaspl1 ghcaspl2 double mutant showed reduced membrane binding and decreased enzyme activity compared to the wild type.GhCASPL1 binds strongly to phosphatidic acid(PA),which is present in much higher amounts in thickening fiber cells compared to ovules and leaves.Mutating the PA-binding site in GhCASPL1 resulted in the loss of its colocalization with GhCesA8,and it failed to localize to the plasma membrane.PA may alter membrane structure to facilitate protein–protein interactions,suggesting that GhCASPL1 and PA collaboratively stabilize the CSC.Our findings shed light on CASPL functions and the molecular machinery behind SCW biosynthesis in cotton fibers.展开更多
BACKGROUND Post-transplant nephrotic syndrome(PTNS)in a renal allograft carries a 48%to 77%risk of graft failure at 5 years if proteinuria persists.PTNS can be due to either recurrence of native renal disease or de no...BACKGROUND Post-transplant nephrotic syndrome(PTNS)in a renal allograft carries a 48%to 77%risk of graft failure at 5 years if proteinuria persists.PTNS can be due to either recurrence of native renal disease or de novo glomerular disease.Its prognosis depends upon the underlying pathophysiology.We describe a case of post-transplant membranous nephropathy(MN)that developed 3 mo after kidney transplant.The patient was properly evaluated for pathophysiology,which helped in the management of the case.CASE SUMMARY This 22-year-old patient had chronic pyelonephritis.He received a living donor kidney,and human leukocyte antigen-DR(HLA-DR)mismatching was zero.PTNS was discovered at the follow-up visit 3 mo after the transplant.Graft histopathology was suggestive of MN.In the past antibody-mediated rejection(ABMR)might have been misinterpreted as de novo MN due to the lack of technologies available to make an accurate diagnosis.Some researchers have observed that HLA-DR is present on podocytes causing an anti-DR antibody deposition and development of de novo MN.They also reported poor prognosis in their series.Here,we excluded the secondary causes of MN.Immunohistochemistry was suggestive of IgG1 deposits that favoured the diagnosis of de novo MN.The patient responded well to an increase in the dose of tacrolimus and angiotensin converting enzyme inhibitor.CONCLUSION Exposure of hidden antigens on the podocytes in allografts may have led to subepithelial antibody deposition causing de novo MN.展开更多
Hydrophilic acid-resistant Ge-ZSM-5 membranes were synthesized via secondary growth method on porous a-A1203 substrates with Silicalite-1 zeolite as seeds. The membranes were characterized by means of scanning electro...Hydrophilic acid-resistant Ge-ZSM-5 membranes were synthesized via secondary growth method on porous a-A1203 substrates with Silicalite-1 zeolite as seeds. The membranes were characterized by means of scanning electron microscopy, X-ray diffraction and energy dispersive X-ray spectrometer to look into the microstructures and element contents of the membranes. The separation performance of the membranes was investigated for separating water from acetic acid solution by pervaporation. The results show that membranes fabricated by the conventional secondary growth method have a high flux, but the selectivity of them is rather limited. Preheating the secondary synthesis sol and using the supernatant as the secondary synthesis sol for membrane fabrication were found to be ef- fective to lower the concentration of the nutrient to constrain re-nucleation, at the same time, lower the A1 content in the membranes. The membrane obtained exhibited improved separation performance with a separation factor of 83 at a flux of 0.67 kg.rn-2.h-1 at 353 K for a feed concentration of 98% acetic acid solution.展开更多
Based on the volcanic relationship between catalytic activity and key adsorption energies,Pt-Co alloy materials have been widely studied as cathode oxygen reduction reaction(ORR)catalysts in proton exchange membrane f...Based on the volcanic relationship between catalytic activity and key adsorption energies,Pt-Co alloy materials have been widely studied as cathode oxygen reduction reaction(ORR)catalysts in proton exchange membrane fuel cells(PEMFCs)due to their higher active surface area and adjustable D-band energy levels compared to Pt/C.However,how to balance the alloying degree and ORR performance of Pt-Co catalyst remains a great challenge.Herein,we first synthesized a well-dispersed Pt/Co/C precursor by using a mild dimethylamine borane(DMAB)as the reducing agent.The precursor was calcined at high temperature under H_(2)/Ar mixed gas by a secondary reduction strategy to obtain an ordered Pt_(3)Co intermetallic compound nanoparticle catalyst with a high degree of alloying.The optimization of elec-tronic structure due to Pt-Co alloying and the strong metal-carrier interaction ensure the high kinetic activity of the cell membrane electrode.Additionally,the high degree of graphitization increases the electrical conductivity during the reaction.As a result,the activity and stability of the catalyst were significantly improved,with a half-wave potential as high as 0.87 V,which decreased by only 20 mV after 10000 potential cycles.Single-cell tests further validate the high intrinsic activity of the ordered Pt_(3)Co catalyst with mass activity up to 0.67 A mg_(pt)^(-1),exceeding the United States Department of Energy(US DOE)standard(0.44 A mg_(pt)^(-1)),and a rated power of 5.93 W mg_(pt)^(-1).展开更多
The membrane insertion mechanism of toxic protein is a very active domain in the study of molecular biology. and the “anchor state” of the membrane-hund protein on membrane is the key problem which it is difficult t...The membrane insertion mechanism of toxic protein is a very active domain in the study of molecular biology. and the “anchor state” of the membrane-hund protein on membrane is the key problem which it is difficult to solve with traditional methotls. In the present work we first studied the “anchor state” of melittin on membrane using liquid secondary ion mass spectrometry (LSIMS) in combination with proteolysis by specific enzyme. The results show that the membrane-bound melittin molecules mainly take the conformation in which the axis of α-helix lies parallel to the membrane surface and the side containing Lys7, Lys2I and Arg22 faces the outside of the lipid membrane. This discovery is very significant to the studies of membrane insertion mechanism. The results also indicate that the combination of mass spectrometry technique with the proteolysis by specific enzyme has provided a very new and effective method for the studies of the membrane insertion mechanism.展开更多
文摘·AIM:To evaluate the role of internal limiting membrane(ILM)peeling in preventing secondary epiretinal membrane(ERM)formation in pars plana vitrectomy(PPV)for proliferative diabetic retinopathy(PDR).·METHODS:This retrospective study analyzed the medical records of patients who underwent PPV for PDR and were followed up for minimum 3 mo.ILM peeling was performed based on the intraoperative surgeons’judgments.ERM was assessed by optical coherence tomography photography.The relationship between ILM peeling and postoperative ERM was analyzed.·RESULTS:In total,212 eyes from 197 patients were included in this study.The incidence of secondary ERM in the ILM non-peeling group was significantly higher than that in the ILM peeling group(37.0%vs 14.0%;P<0.001).Multivariate logistical regression revealed that ILM peeling was highly associated with the prevention of secondary ERM development[odds ratio 0.38;95%confidence interval0.17-0.86;P<0.05].·CONCLUSION:ILM peeling during PPV for PDRs can effectively reduce the incidence of secondary ERM development and is worth consideration by vitreoretinal surgeons.
基金Project(21376274)supported by the National Natural Science Foundation ChinaProject(2015BAL04B02)supported by the National Key Technology R&D Program of China
文摘A zeolitic imidazolate hybrid membrane(Co-IM-mIM) containing two imidazolate ligands deposited on a macroporous α-alumina support was prepared by pre-depositing and secondary growth technique. XRD, TGA and SEM characterizations demonstrate that a stable and thin, but dense and pure-phase Co-IM-mIM membrane can be obtained on the macroporous-alumina discs in Teflon-lined autoclave at 120 °C after pre-depositing by dip-coating at room temperature. No visible cracks, pinholes or other defects were observed on the membrane layer. The gas separation studies of Co-IM-mIM membrane were carried out at 25 °C and 1×10~5 Pa, showing ideal selectivity of 6.95, 5.25, 3.40 for H_2/CO_2, H_2/N_2 and H_2/CH_4, respectively, and a permeance of 17.37× 10^(-6) mol/(m^2·s·Pa) for H_2. The influence of temperature and trans-membrane pressure on hydrogen separation and permeation was also carried out. The gas permeation and selectivity demonstrate that this membrane may have potential applications for efficient H_2 separation.
文摘High quality A-type zeolite membranes, with enlarged area over 70 cm2, were successfully synthesized on a tubular a-Al2O3 support by applying the vacuum seeding method.
基金the financial supports that are from the National Natural Science Foundation of China (21921006, U22A20414 and 21938007)the Natural Science Foundation of Jiangsu Province (BK20220002)the open project of the State Key Laboratory of China (KL21-04 and D2021FK055)。
文摘The synthesis of a continuous IMF zeolite membrane was fabricated on tubular substrates by seeded growth for the first time. The straight channels of IMF zeolite with diameters of 0.53–0.59 nm are distinguishable for p-xylene from o-xylene molecules. Pure IMF-phase high-silica IM-5 zeolite seeds with uniform and fine crystal size were fabricated by a new sonication-assisted aging process. The seeds were coated on the support by dipcoating and induced the formation of continuous membrane. Separation performance in p-/o-xylene mixture was investigated at various temperature and pressure. The typical IM-5zeolite membrane had p-/o-xylene separation factor of 3.7. Our results suggest that IM-5 zeolite is a potentially good membrane material for the separation of xylene mixtures.
基金supported by the grants from STI 2030—Major Project(2023ZD04069)the Natural Science Foundation of China(32388101 and 32200286)+2 种基金Foundation of Hubei Hongshan Laboratory(2021hszd014)Hubei Provincial Natural Science Foundation of China(2021CFA055)China Postdoctoral Science Foundation(2022TQ0240,2022M722470).
文摘Cotton(Gossypium hirsutum)fibers are elongated single cells that rapidly accumulate cellulose during secondary cell wall(SCW)thickening,which requires cellulose synthase complex(CSC)activity.Here,we describe the CSC-interacting factor CASPARIAN STRIP MEMBRANE DOMAIN-LIKE1(GhCASPL1),which contributes to SCW thickening by influencing CSC stability on the plasma membrane.GhCASPL1 is preferentially expressed in fiber cells during SCW biosynthesis and encodes a MARVEL domain protein.The ghcaspl1 ghcaspl2 mutant exhibited reduced plant height and produced mature fibers with fewer natural twists,lower tensile strength,and a thinner SCW compared to the wild type.Similarly,the Arabidopsis(Arabidopsis thaliana)caspl1 caspl2 double mutant showed a lower cellulose content and thinner cell walls in the stem vasculature than the wild type but normal plant morphology.Introducing the cotton gene GhCASPL1 successfully restored the reduced cellulose content of the Arabidopsis caspl1 caspl2 mutant.Detergent treatments,ultracentrifugation assays,and enzymatic assays showed that the CSC in the ghcaspl1 ghcaspl2 double mutant showed reduced membrane binding and decreased enzyme activity compared to the wild type.GhCASPL1 binds strongly to phosphatidic acid(PA),which is present in much higher amounts in thickening fiber cells compared to ovules and leaves.Mutating the PA-binding site in GhCASPL1 resulted in the loss of its colocalization with GhCesA8,and it failed to localize to the plasma membrane.PA may alter membrane structure to facilitate protein–protein interactions,suggesting that GhCASPL1 and PA collaboratively stabilize the CSC.Our findings shed light on CASPL functions and the molecular machinery behind SCW biosynthesis in cotton fibers.
文摘BACKGROUND Post-transplant nephrotic syndrome(PTNS)in a renal allograft carries a 48%to 77%risk of graft failure at 5 years if proteinuria persists.PTNS can be due to either recurrence of native renal disease or de novo glomerular disease.Its prognosis depends upon the underlying pathophysiology.We describe a case of post-transplant membranous nephropathy(MN)that developed 3 mo after kidney transplant.The patient was properly evaluated for pathophysiology,which helped in the management of the case.CASE SUMMARY This 22-year-old patient had chronic pyelonephritis.He received a living donor kidney,and human leukocyte antigen-DR(HLA-DR)mismatching was zero.PTNS was discovered at the follow-up visit 3 mo after the transplant.Graft histopathology was suggestive of MN.In the past antibody-mediated rejection(ABMR)might have been misinterpreted as de novo MN due to the lack of technologies available to make an accurate diagnosis.Some researchers have observed that HLA-DR is present on podocytes causing an anti-DR antibody deposition and development of de novo MN.They also reported poor prognosis in their series.Here,we excluded the secondary causes of MN.Immunohistochemistry was suggestive of IgG1 deposits that favoured the diagnosis of de novo MN.The patient responded well to an increase in the dose of tacrolimus and angiotensin converting enzyme inhibitor.CONCLUSION Exposure of hidden antigens on the podocytes in allografts may have led to subepithelial antibody deposition causing de novo MN.
基金Supported by the National Natural Science Foundation of China（No.21201130） and the Foundation of the State Key Labora- tory of Coal Conversion, China（No.J14-15-603）.
文摘Hydrophilic acid-resistant Ge-ZSM-5 membranes were synthesized via secondary growth method on porous a-A1203 substrates with Silicalite-1 zeolite as seeds. The membranes were characterized by means of scanning electron microscopy, X-ray diffraction and energy dispersive X-ray spectrometer to look into the microstructures and element contents of the membranes. The separation performance of the membranes was investigated for separating water from acetic acid solution by pervaporation. The results show that membranes fabricated by the conventional secondary growth method have a high flux, but the selectivity of them is rather limited. Preheating the secondary synthesis sol and using the supernatant as the secondary synthesis sol for membrane fabrication were found to be ef- fective to lower the concentration of the nutrient to constrain re-nucleation, at the same time, lower the A1 content in the membranes. The membrane obtained exhibited improved separation performance with a separation factor of 83 at a flux of 0.67 kg.rn-2.h-1 at 353 K for a feed concentration of 98% acetic acid solution.
基金supported by the National Key Research and Development Program of China(grant No.2022YFB3807500)the National Natural Science Foundation of China(grant No.21922802,22220102003)+1 种基金the Beijing Natural Science Foundation(grant No.JQ19007)“Double-First-Class”construction projects(grant No.XK180301,XK1804-02).
文摘Based on the volcanic relationship between catalytic activity and key adsorption energies,Pt-Co alloy materials have been widely studied as cathode oxygen reduction reaction(ORR)catalysts in proton exchange membrane fuel cells(PEMFCs)due to their higher active surface area and adjustable D-band energy levels compared to Pt/C.However,how to balance the alloying degree and ORR performance of Pt-Co catalyst remains a great challenge.Herein,we first synthesized a well-dispersed Pt/Co/C precursor by using a mild dimethylamine borane(DMAB)as the reducing agent.The precursor was calcined at high temperature under H_(2)/Ar mixed gas by a secondary reduction strategy to obtain an ordered Pt_(3)Co intermetallic compound nanoparticle catalyst with a high degree of alloying.The optimization of elec-tronic structure due to Pt-Co alloying and the strong metal-carrier interaction ensure the high kinetic activity of the cell membrane electrode.Additionally,the high degree of graphitization increases the electrical conductivity during the reaction.As a result,the activity and stability of the catalyst were significantly improved,with a half-wave potential as high as 0.87 V,which decreased by only 20 mV after 10000 potential cycles.Single-cell tests further validate the high intrinsic activity of the ordered Pt_(3)Co catalyst with mass activity up to 0.67 A mg_(pt)^(-1),exceeding the United States Department of Energy(US DOE)standard(0.44 A mg_(pt)^(-1)),and a rated power of 5.93 W mg_(pt)^(-1).
文摘The membrane insertion mechanism of toxic protein is a very active domain in the study of molecular biology. and the “anchor state” of the membrane-hund protein on membrane is the key problem which it is difficult to solve with traditional methotls. In the present work we first studied the “anchor state” of melittin on membrane using liquid secondary ion mass spectrometry (LSIMS) in combination with proteolysis by specific enzyme. The results show that the membrane-bound melittin molecules mainly take the conformation in which the axis of α-helix lies parallel to the membrane surface and the side containing Lys7, Lys2I and Arg22 faces the outside of the lipid membrane. This discovery is very significant to the studies of membrane insertion mechanism. The results also indicate that the combination of mass spectrometry technique with the proteolysis by specific enzyme has provided a very new and effective method for the studies of the membrane insertion mechanism.
