A novel amidoxime-based fibrous adsorbent,denoted as PE/PP-g-(PAAc-co-PAO), was prepared by preirradiation grafting of acrylic acid and acrylonitrile onto polyethylene-coated polypropylene skin-core(PE/PP)fibers using...A novel amidoxime-based fibrous adsorbent,denoted as PE/PP-g-(PAAc-co-PAO), was prepared by preirradiation grafting of acrylic acid and acrylonitrile onto polyethylene-coated polypropylene skin-core(PE/PP)fibers using 60 Co γ-ray irradiation, followed by amidoximation. The original and modified PE/PP fibers were characterized by a series of characterization methods to demonstrate the attachment of amidoxime groups onto the PE/PP fibers. Breaking strength tests confirmed that the fibrous adsorbent could maintain good mechanical properties. The adsorption capacity of the PE/PP-g-(PAAc-coPAO) fibers was investigated in simulated seawater with an initial uranium concentration of 330 μg/L. The uranium adsorption capacity was 2.27 mg/g-adsorbent after 24 h in simulated seawater, and the equilibrium data were well described by the Freundlich isotherm model. The PE/PP-g-(PAAc-co-PAO) adsorbent exhibited good regeneration and recyclability during five adsorption-desorption cycles.The adsorption test was also performed in simulated radioactive effluents with uranium concentrations of 10 and100 μg/L. The effect of the pH value on the adsorption capacity was also studied. At a very low initial concentration 10 μg/L solution, the PE/PP-g-(PAAc-co-PAO)fiber could remove as much as 93.0% of the uranium, and up to 71.2% of the uranium in the simulated radioactive effluent. These results indicated that the PE/PP-g-(PAAcco-PAO) adsorbent could be used in radioactive effluents over a wide range of pH values. Therefore, the PE/PP-g-(PAAc-co-PAO) fibers, with their high uranium selectivity,good regeneration and recyclability,good mechanical properties, and low cost, are promising adsorbents for extracting uranium from aqueous solutions.展开更多
Finding the novel drug from the effective components of traditional Chinese herbal medicine is a hotspot of the modem pharmacological research. Hyperoside （HYP） belongs to flavonoid glycosides, and it has various pr...Finding the novel drug from the effective components of traditional Chinese herbal medicine is a hotspot of the modem pharmacological research. Hyperoside （HYP） belongs to flavonoid glycosides, and it has various properties, such as anti-inflammation, anti-spasm, anti-diuretic, antitussive, lowering blood pressure, and lowering cholesterol effects as well as protective effects for the cardiac and cerebral blood vessels. The purpose of this study was to investigate the effects of HYP on inflammatory and apoptotic responses in vascular endothelial cells stimulated by lipopolysaccharide （LPS） and further to identify the possible mechanisms underlying these effects. In our study, human umbilical vein endothelial cells （HUVECs） were stimulated with 1 Bg/mL LPS in the presence or absence of HYP （10, 20 and 50 μmol/L）. Our results indicated that HYP alone exerted no cytotoxicity on HUVECs, while it had an upregulatory effect on the viability of HUVECs induced by LPS in a dose-dependent manner; increased mRNA expression of IL-1β, IL-6, TNFα and iNOS induced by LPS was attenuated after treatment with HYP both in a dose- and time-dependent manner; LPS-induced HUVECs apoptosis and cleaved-caspase 8, 9, 3 were all significantly reduced by HYP. Furthermore, the possible pathway involved in apoptosis and inflammation by HYP was detected, and the results showed that when treated with HYP, LPS-induced mitochondrial membrane instability was significantly inhibited through up-regulation of Bcl-2 and down-regulation of Bax. Furthermore, the expression of TLR4 and the phosphorylation of IκBα and p65 in LPS-treated cells were blocked by HYP. Our results suggested that HYP treatment prevented HUVECs from LPS- induced inflammation and apoptosis responses, which might be mediated by inhibiting TLR4/ NFκB pathway.展开更多
Background Implementing the current guidelines for leisure-time physical activity(LTPA)provides significant health benefits,especially for middle-aged adults,but it is unclear whether LTPA also translates into cardiov...Background Implementing the current guidelines for leisure-time physical activity(LTPA)provides significant health benefits,especially for middle-aged adults,but it is unclear whether LTPA also translates into cardiovascular health benefits among elderly people.Therefore,we aimed to assess the association of LTPA with the risks of cardiovascular disease(CVD),including coronary heart disease(CHD)and stroke,and all-cause mortality in an elderly population.Methods In this prospective cohort study,32,942 participants aged 60 years or older who participated in a health check-up programme in China between 2010 and 2018 were included.We evaluated the morbidity and mortality risks through the Cox regression model,competing risk model and restricted cubic spline model.Results During a median of 6.84 years of follow-up,there were 6,857 elderly people with incident CVD;a total of 6,324 deaths occurred due to all causes and 2,060 deaths occurred due to CVD.Compared with the inactive group,reductions in CVD morbidity and mortality were observed,with hazard ratios(HRs)of 0.89(95%CI:0.83–0.96)and 0.81(95%CI:0.71–0.92)in the insufficiently active group,0.86(95%CI:0.80–0.92)and 0.79(95%CI:0.69–0.90)in the sufficiently active group,and 0.79(95%CI:0.70–0.89)and 0.58(95%CI:0.45–0.76)in the highly active group,respectively;but no significant reductions were observed in the very highly active group,with HRs of 0.87(95%CI:0.71–1.06)and 0.99(95%CI:0.70–1.40),respectively.Compared with the inactive group,reductions in all-cause mortality were also observed,with a HR of 0.90(95%CI:0.84–0.97)in the insufficiently active group,0.82(95%CI:0.77–0.89)in the sufficiently active group,0.77(95%CI:0.67–0.87)in the highly active group,and 0.80(95%CI:0.64–0.98)in the very highly active group.A restricted cubic spline diagram showed that there was an L-shaped association between LTPA and the risk of all-cause mortality but a U-shaped or reverse J-shaped relationship between LTPA and the risk of CVD morbidity and mortality,especially stroke.In addition,a subgroup analysis showed that elderly population who consistently performed LTPA for ten years or more had a lower risk of morbidity and mortality.Conclusions In an elderly population,even insufficient activity is associated with a decreased risk of all-cause mortality and CVD,and moderate levels of LTPA may be optimal for CVD prevention.In addition,elderly people who consistently perform LTPA over several years may experience greater health benefits.展开更多
Lambda polarization can be measured through its self-analyzing weak decay, making it an ideal candidate for studying spin effects in high-energy scattering. In lepton-nucleon deep inelastic scattering(DIS), Lambda pol...Lambda polarization can be measured through its self-analyzing weak decay, making it an ideal candidate for studying spin effects in high-energy scattering. In lepton-nucleon deep inelastic scattering(DIS), Lambda polarization measurements can probe polarized parton distribution functions(PDFs) and polarized fragmentation functions(FFs). One of the most promising facilities for high-energy nuclear physics research is the proposed Electron-ion collider in China(EicC). As a next-generation facility, EicC is set to advance our understanding of nuclear physics to new heights. In this article, we study the Lambda production in electron-proton collisions at the EicC energy, in particular the reconstruction of Lambda based on the performance of the designed EicC detector. In addition, taking spontaneous transverse polarization as an example, we provide a theoretical prediction with a statistical projection based on one month of EicC data, offering valuable insights into future research prospects.展开更多
BACKGROUND To examine the association of baseline waist circumference(WC)and changes in WC with cardiovascular disease(CVD)and all-cause mortality among elderly people.METHODS A total of 30,041 eligible participants w...BACKGROUND To examine the association of baseline waist circumference(WC)and changes in WC with cardiovascular disease(CVD)and all-cause mortality among elderly people.METHODS A total of 30,041 eligible participants were included from a retrospective cohort in China.The same questionnaire,anthropometric and laboratory measurements were performed at baseline(2010)and the first follow-up(2013).The percent change in WC between baseline and the first follow-up was calculated to evaluate three years change of WC.We collected the occurrence of CVD and all-cause death from the first follow-up to December 31,2018.Restricted cubic splines and Cox proportionalhazards regression models were used to evaluate the relationship between baseline WC/changes in WC and mortality.RESULTS The dose-response relationships between baseline WC and CVD mortality were U-or J-shaped.In low WC group,compared with stable group,the fully adjusted hazard ratio(aHR)for CVD mortality was 1.60(95%CI:1.24−2.06)in WC gain group among men.In normal WC group,the CVD mortality risk increased with WC gain(men:aHR=1.86,95%CI:1.36−2.56;women:aHR=1.83,95%CI:1.29−2.58).In moderate-high WC group,the CVD mortality risk increased with WC gain(men:aHR=1.76,95%CI:1.08−2.88;women:aHR=1.46,95%CI:1.04−2.05)and risk decreased with WC loss(men:aHR=0.54,95%CI:0.30−0.98;women:aHR=0.59,95%CI:0.37−0.96).CONCLUSIONS For the elderly population,WC gain may increase CVD mortality risk regardless of baseline WC,whereas WC reduction could decrease the risk only in the moderate-high WC group.展开更多
Development of photocatalytic materials able to profit from the whole spectrum of sun for efficient organic pollution removal and bacterial elimination is a fascinating strategy in environmental engineering.In current...Development of photocatalytic materials able to profit from the whole spectrum of sun for efficient organic pollution removal and bacterial elimination is a fascinating strategy in environmental engineering.In current work,GO-TiO_(2)/(Ca,Y)F_(2):Tm,Yb,a full-spectrum composite photocatalyst,was prepared via hydrothermal processing with TiO_(2)/(Ca,Y)F_(2):Tm,Yb particles deposited on the surface of graphene oxide(GO).The surface properties of GO-TiO_(2)/(Ca,Y)F_(2):Tm,Yb were characterized using various characterization techniques including X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS)and Brunauer–Emmett–Teller(BET)surface area analyzer.Besides,ultraviolet–visible(UV–Vis)diffuse reflectance spectroscopy,electron spin resonance(ESR)and other methods were used to systematically explore the photocatalytic mechanism of GO enhancement of TiO_(2)/(Ca,Y)F_(2):Tm,Yb.In photocatalytic degradation study,the degradation rate of methyl orange(MO)was improved by 40%when GO was added into the TiO_(2)/(Ca,Y)F_(2):Tm,Yb system.In addition,the presence of GO also improves the antibacterial ability of TiO_(2)/(Ca,Y)F_(2):Tm,Yb against Escherichia coli and Staphylococcus aureus.All results reveal high efficacy of GOTiO_(2)/(Ca,Y)F_(2):Tm,Yb under full spectrum light irradiation,in which(Ca,Y)F2:Tm,Yb and TiO2 can improve its utilization of full spectrum sunlight,and GO can enhance adsorption ability of dye and electron–hole pair differentiation ability of TiO_(2)/(Ca,Y)F_(2):Tm,Yb.展开更多
A rigid aromatic diamine monomer containing di-tert-butylbenzene and dimethyl groups,3,3'-dimethyl-4,4'-diaminophenyl-3",5"-di-tert-butyltoluene,was successfully synthesized by a simple coupling reac...A rigid aromatic diamine monomer containing di-tert-butylbenzene and dimethyl groups,3,3'-dimethyl-4,4'-diaminophenyl-3",5"-di-tert-butyltoluene,was successfully synthesized by a simple coupling reaction using 3,5-di-tert-butylbenzaldehyde and o-toluidine as starting materials.A series of novel polyimides(PI 3a-3c)with large pendant groups were prepared with the obtained diamine monomer and three different commercial aromatic dianhydrides(3,3',4,4'-biphenyltetracarboxylic dianhydride,4,4'-oxydiphthalic anhydride,and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride)by one-step high temperature polycondensation.The prepared polyimides exhibited high solubility and good membrane forming ability:they could be dissolved not only in some high boiling solvents such as DMF,NMP,DMAc,and m-Cresol at room temperature,but also in some low boiling solvents such as CHCl3,CH2Cl2,and THF.Their solubility in most solvents could exceed 10 wt%,and the flexible membranes could be obtained by casting their solutions.The prepared membranes exhibited good gas separation properties.The permeability coefficients of PI 3c for CO2 and O2 were up to 124.6 and 42.8 barrer,respectively,and the selectivity coefficients for CO2/CH4 and O2/N2 were 14.7 and 3.3,respectively.The membranes had light color and good optical transmission.Their optical transmittance at 450 nm wavelength was in the range of 67%-79%,and the cutoff wavelength was in the range of 310-348 nm.They also had good thermal properties with glass transition temperature(Tg)values in the range of 264-302℃.In addition,these membranes possessed good mechanical properties with tensile strength ranging between 77.8-87.4 MPa,initial modulus ranging between 1.69-1.82 GPa,and elongation at break ranging between 4.8%-6.1%.展开更多
Ventricular septal rupture(VSR)is a rare but lethal complication of acute myocardial infarction(AMI).[1]Emergent repair surgery provides the only chance for survival for patients with VSR;however,the perioperative mor...Ventricular septal rupture(VSR)is a rare but lethal complication of acute myocardial infarction(AMI).[1]Emergent repair surgery provides the only chance for survival for patients with VSR;however,the perioperative mortality rate remains extremely high at the early phase.[2] Elective surgery is widely utilized in real-world clinical practice and is associated with improved prognosis.[3] Nevertheless,the results of elective surgery might be a manifestation of survival bias,as it is usually performed in relatively stable patients with VSR who are expected to survive the early stage and have a better prognosis than patients complicated with hemodynamic instability in the early stage.[4]In this study,we aimed to present a novel surgical repair technique that can be safely,feasibly,and effectively used in hemodynamically unstable patients with VSR in the acute phase and to report the preliminary results.展开更多
基金Supported by Grants from the Innovation Fund for Technology Based Firms of the Ministry of Science and Technology of the China,No.12C26215115999(in part)Special Fund on Industrial Revitalization and Transformation of the National Development and Reform Commission of the ChinaJinshan Science and Technology Co.Ltd,Chongqing,China
文摘AIM: To investigate the feasibility and safety of pH capsule to monitor pH in patients with gastroesophageal reflux disease (GERD).
基金supported by the National Natural Science Foundation of China(Nos.U1732151 and 21676291)Strategic Pilot and Technology Special Funds of the Chinese Academy of Science(No.XDA02030200)
文摘A novel amidoxime-based fibrous adsorbent,denoted as PE/PP-g-(PAAc-co-PAO), was prepared by preirradiation grafting of acrylic acid and acrylonitrile onto polyethylene-coated polypropylene skin-core(PE/PP)fibers using 60 Co γ-ray irradiation, followed by amidoximation. The original and modified PE/PP fibers were characterized by a series of characterization methods to demonstrate the attachment of amidoxime groups onto the PE/PP fibers. Breaking strength tests confirmed that the fibrous adsorbent could maintain good mechanical properties. The adsorption capacity of the PE/PP-g-(PAAc-coPAO) fibers was investigated in simulated seawater with an initial uranium concentration of 330 μg/L. The uranium adsorption capacity was 2.27 mg/g-adsorbent after 24 h in simulated seawater, and the equilibrium data were well described by the Freundlich isotherm model. The PE/PP-g-(PAAc-co-PAO) adsorbent exhibited good regeneration and recyclability during five adsorption-desorption cycles.The adsorption test was also performed in simulated radioactive effluents with uranium concentrations of 10 and100 μg/L. The effect of the pH value on the adsorption capacity was also studied. At a very low initial concentration 10 μg/L solution, the PE/PP-g-(PAAc-co-PAO)fiber could remove as much as 93.0% of the uranium, and up to 71.2% of the uranium in the simulated radioactive effluent. These results indicated that the PE/PP-g-(PAAcco-PAO) adsorbent could be used in radioactive effluents over a wide range of pH values. Therefore, the PE/PP-g-(PAAc-co-PAO) fibers, with their high uranium selectivity,good regeneration and recyclability,good mechanical properties, and low cost, are promising adsorbents for extracting uranium from aqueous solutions.
文摘Finding the novel drug from the effective components of traditional Chinese herbal medicine is a hotspot of the modem pharmacological research. Hyperoside （HYP） belongs to flavonoid glycosides, and it has various properties, such as anti-inflammation, anti-spasm, anti-diuretic, antitussive, lowering blood pressure, and lowering cholesterol effects as well as protective effects for the cardiac and cerebral blood vessels. The purpose of this study was to investigate the effects of HYP on inflammatory and apoptotic responses in vascular endothelial cells stimulated by lipopolysaccharide （LPS） and further to identify the possible mechanisms underlying these effects. In our study, human umbilical vein endothelial cells （HUVECs） were stimulated with 1 Bg/mL LPS in the presence or absence of HYP （10, 20 and 50 μmol/L）. Our results indicated that HYP alone exerted no cytotoxicity on HUVECs, while it had an upregulatory effect on the viability of HUVECs induced by LPS in a dose-dependent manner; increased mRNA expression of IL-1β, IL-6, TNFα and iNOS induced by LPS was attenuated after treatment with HYP both in a dose- and time-dependent manner; LPS-induced HUVECs apoptosis and cleaved-caspase 8, 9, 3 were all significantly reduced by HYP. Furthermore, the possible pathway involved in apoptosis and inflammation by HYP was detected, and the results showed that when treated with HYP, LPS-induced mitochondrial membrane instability was significantly inhibited through up-regulation of Bcl-2 and down-regulation of Bax. Furthermore, the expression of TLR4 and the phosphorylation of IκBα and p65 in LPS-treated cells were blocked by HYP. Our results suggested that HYP treatment prevented HUVECs from LPS- induced inflammation and apoptosis responses, which might be mediated by inhibiting TLR4/ NFκB pathway.
基金supported by National Key Research and Development Programme of China(2017YFC1307705&2016YFC0106907)the Science and Technology Development Programme of Henan(No.201403007)。
文摘Background Implementing the current guidelines for leisure-time physical activity(LTPA)provides significant health benefits,especially for middle-aged adults,but it is unclear whether LTPA also translates into cardiovascular health benefits among elderly people.Therefore,we aimed to assess the association of LTPA with the risks of cardiovascular disease(CVD),including coronary heart disease(CHD)and stroke,and all-cause mortality in an elderly population.Methods In this prospective cohort study,32,942 participants aged 60 years or older who participated in a health check-up programme in China between 2010 and 2018 were included.We evaluated the morbidity and mortality risks through the Cox regression model,competing risk model and restricted cubic spline model.Results During a median of 6.84 years of follow-up,there were 6,857 elderly people with incident CVD;a total of 6,324 deaths occurred due to all causes and 2,060 deaths occurred due to CVD.Compared with the inactive group,reductions in CVD morbidity and mortality were observed,with hazard ratios(HRs)of 0.89(95%CI:0.83–0.96)and 0.81(95%CI:0.71–0.92)in the insufficiently active group,0.86(95%CI:0.80–0.92)and 0.79(95%CI:0.69–0.90)in the sufficiently active group,and 0.79(95%CI:0.70–0.89)and 0.58(95%CI:0.45–0.76)in the highly active group,respectively;but no significant reductions were observed in the very highly active group,with HRs of 0.87(95%CI:0.71–1.06)and 0.99(95%CI:0.70–1.40),respectively.Compared with the inactive group,reductions in all-cause mortality were also observed,with a HR of 0.90(95%CI:0.84–0.97)in the insufficiently active group,0.82(95%CI:0.77–0.89)in the sufficiently active group,0.77(95%CI:0.67–0.87)in the highly active group,and 0.80(95%CI:0.64–0.98)in the very highly active group.A restricted cubic spline diagram showed that there was an L-shaped association between LTPA and the risk of all-cause mortality but a U-shaped or reverse J-shaped relationship between LTPA and the risk of CVD morbidity and mortality,especially stroke.In addition,a subgroup analysis showed that elderly population who consistently performed LTPA for ten years or more had a lower risk of morbidity and mortality.Conclusions In an elderly population,even insufficient activity is associated with a decreased risk of all-cause mortality and CVD,and moderate levels of LTPA may be optimal for CVD prevention.In addition,elderly people who consistently perform LTPA over several years may experience greater health benefits.
基金supported by the National Natural Science Foundation of China (Nos.12275159, 12075140, and 12175117)100 Talents Program of CASShandong Provincial Natural Science Foundation (No. ZFJH202303)。
文摘Lambda polarization can be measured through its self-analyzing weak decay, making it an ideal candidate for studying spin effects in high-energy scattering. In lepton-nucleon deep inelastic scattering(DIS), Lambda polarization measurements can probe polarized parton distribution functions(PDFs) and polarized fragmentation functions(FFs). One of the most promising facilities for high-energy nuclear physics research is the proposed Electron-ion collider in China(EicC). As a next-generation facility, EicC is set to advance our understanding of nuclear physics to new heights. In this article, we study the Lambda production in electron-proton collisions at the EicC energy, in particular the reconstruction of Lambda based on the performance of the designed EicC detector. In addition, taking spontaneous transverse polarization as an example, we provide a theoretical prediction with a statistical projection based on one month of EicC data, offering valuable insights into future research prospects.
基金supported by the National Key Research and Development Programme of China(2017YFC1307705&2016YFC0106907)the Science and Technology Development Programme of Henan(No.201403007).
文摘BACKGROUND To examine the association of baseline waist circumference(WC)and changes in WC with cardiovascular disease(CVD)and all-cause mortality among elderly people.METHODS A total of 30,041 eligible participants were included from a retrospective cohort in China.The same questionnaire,anthropometric and laboratory measurements were performed at baseline(2010)and the first follow-up(2013).The percent change in WC between baseline and the first follow-up was calculated to evaluate three years change of WC.We collected the occurrence of CVD and all-cause death from the first follow-up to December 31,2018.Restricted cubic splines and Cox proportionalhazards regression models were used to evaluate the relationship between baseline WC/changes in WC and mortality.RESULTS The dose-response relationships between baseline WC and CVD mortality were U-or J-shaped.In low WC group,compared with stable group,the fully adjusted hazard ratio(aHR)for CVD mortality was 1.60(95%CI:1.24−2.06)in WC gain group among men.In normal WC group,the CVD mortality risk increased with WC gain(men:aHR=1.86,95%CI:1.36−2.56;women:aHR=1.83,95%CI:1.29−2.58).In moderate-high WC group,the CVD mortality risk increased with WC gain(men:aHR=1.76,95%CI:1.08−2.88;women:aHR=1.46,95%CI:1.04−2.05)and risk decreased with WC loss(men:aHR=0.54,95%CI:0.30−0.98;women:aHR=0.59,95%CI:0.37−0.96).CONCLUSIONS For the elderly population,WC gain may increase CVD mortality risk regardless of baseline WC,whereas WC reduction could decrease the risk only in the moderate-high WC group.
基金This work was financially supported by the National Key Research and Development Program of China(No.2020YFC1107403)the National Natural Science Foundation of China(No.51771069)the Natural Science Foundation of Hebei Province of China(No.E2020202028).
文摘Development of photocatalytic materials able to profit from the whole spectrum of sun for efficient organic pollution removal and bacterial elimination is a fascinating strategy in environmental engineering.In current work,GO-TiO_(2)/(Ca,Y)F_(2):Tm,Yb,a full-spectrum composite photocatalyst,was prepared via hydrothermal processing with TiO_(2)/(Ca,Y)F_(2):Tm,Yb particles deposited on the surface of graphene oxide(GO).The surface properties of GO-TiO_(2)/(Ca,Y)F_(2):Tm,Yb were characterized using various characterization techniques including X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS)and Brunauer–Emmett–Teller(BET)surface area analyzer.Besides,ultraviolet–visible(UV–Vis)diffuse reflectance spectroscopy,electron spin resonance(ESR)and other methods were used to systematically explore the photocatalytic mechanism of GO enhancement of TiO_(2)/(Ca,Y)F_(2):Tm,Yb.In photocatalytic degradation study,the degradation rate of methyl orange(MO)was improved by 40%when GO was added into the TiO_(2)/(Ca,Y)F_(2):Tm,Yb system.In addition,the presence of GO also improves the antibacterial ability of TiO_(2)/(Ca,Y)F_(2):Tm,Yb against Escherichia coli and Staphylococcus aureus.All results reveal high efficacy of GOTiO_(2)/(Ca,Y)F_(2):Tm,Yb under full spectrum light irradiation,in which(Ca,Y)F2:Tm,Yb and TiO2 can improve its utilization of full spectrum sunlight,and GO can enhance adsorption ability of dye and electron–hole pair differentiation ability of TiO_(2)/(Ca,Y)F_(2):Tm,Yb.
基金This work was finanially supported by the Key Research Project of Jiangsu Province(No.BE2017645)Scientifc Research and Innovation Project for Graduate Students in Jiangsu Province(No.KYCX19-1757)。and a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions of China。
文摘A rigid aromatic diamine monomer containing di-tert-butylbenzene and dimethyl groups,3,3'-dimethyl-4,4'-diaminophenyl-3",5"-di-tert-butyltoluene,was successfully synthesized by a simple coupling reaction using 3,5-di-tert-butylbenzaldehyde and o-toluidine as starting materials.A series of novel polyimides(PI 3a-3c)with large pendant groups were prepared with the obtained diamine monomer and three different commercial aromatic dianhydrides(3,3',4,4'-biphenyltetracarboxylic dianhydride,4,4'-oxydiphthalic anhydride,and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride)by one-step high temperature polycondensation.The prepared polyimides exhibited high solubility and good membrane forming ability:they could be dissolved not only in some high boiling solvents such as DMF,NMP,DMAc,and m-Cresol at room temperature,but also in some low boiling solvents such as CHCl3,CH2Cl2,and THF.Their solubility in most solvents could exceed 10 wt%,and the flexible membranes could be obtained by casting their solutions.The prepared membranes exhibited good gas separation properties.The permeability coefficients of PI 3c for CO2 and O2 were up to 124.6 and 42.8 barrer,respectively,and the selectivity coefficients for CO2/CH4 and O2/N2 were 14.7 and 3.3,respectively.The membranes had light color and good optical transmission.Their optical transmittance at 450 nm wavelength was in the range of 67%-79%,and the cutoff wavelength was in the range of 310-348 nm.They also had good thermal properties with glass transition temperature(Tg)values in the range of 264-302℃.In addition,these membranes possessed good mechanical properties with tensile strength ranging between 77.8-87.4 MPa,initial modulus ranging between 1.69-1.82 GPa,and elongation at break ranging between 4.8%-6.1%.
文摘Ventricular septal rupture(VSR)is a rare but lethal complication of acute myocardial infarction(AMI).[1]Emergent repair surgery provides the only chance for survival for patients with VSR;however,the perioperative mortality rate remains extremely high at the early phase.[2] Elective surgery is widely utilized in real-world clinical practice and is associated with improved prognosis.[3] Nevertheless,the results of elective surgery might be a manifestation of survival bias,as it is usually performed in relatively stable patients with VSR who are expected to survive the early stage and have a better prognosis than patients complicated with hemodynamic instability in the early stage.[4]In this study,we aimed to present a novel surgical repair technique that can be safely,feasibly,and effectively used in hemodynamically unstable patients with VSR in the acute phase and to report the preliminary results.
