Arc ion plating (AIP) is applied to form Ti/(Ti,Cr)N/CrN multilayer coating on the surface of 316L stainless steel (SS316L) as bipolar plates for proton exchange membrane fuel cells (PEMFCs). The characterizations of ...Arc ion plating (AIP) is applied to form Ti/(Ti,Cr)N/CrN multilayer coating on the surface of 316L stainless steel (SS316L) as bipolar plates for proton exchange membrane fuel cells (PEMFCs). The characterizations of the coating are analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Interfacial contact resistance (ICR) between the coated sample and carbon paper is 4.9 m Omega cm(2) under 150 N/cm(2), which is much lower than that of the SS316L substrate. Potentiodynamic and potentiostatic tests are performed in the simulated PEMFC working conditions to investigate the corrosion behaviors of the coated sample. Superior anticorrosion performance is observed for the coated sample, whose corrosion current density is 0.12 mu A/cm(2). Surface morphology results after corrosion tests indicate that the substrate is well protected by the multilayer coating. Performances of the single cell with the multilayer coated SS316L bipolar plate are improved significantly compared with that of the cell with the uncoated SS316L bipolar plate, presenting a great potential for PEMFC application. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
Proton exchange membrane fuel cell(PEMFC) as a power supply device has attracted wide attention in China and abroad for its advantages of high energy density, energy conversion efficiency and zero pollution.With the v...Proton exchange membrane fuel cell(PEMFC) as a power supply device has attracted wide attention in China and abroad for its advantages of high energy density, energy conversion efficiency and zero pollution.With the vigorous support of China's national policy, research institutes and enterprises have carried out extensive and pragmatic work on the basic materials, key components, stacks, auxiliary systems of PEMFCs, as well as the hydrogen station construction in order to realize the wide application of hydrogen energy.PEMFC System and Engineering Research Center of DICP is one of the earliest players in the H2-PEMFCs field.Advances have been achieved in the fields of low-platinum contained catalysts,PEMs, high-efficiency MEAs, low-cost metal bipolar plates, low-temperature and impurity air environment adaptability, stacks and systems.This paper introduces recent progresses of H2-PEMFCs at DICP in key materials, components, stacks, systems and the applications.The engineering status of proton exchange membrane water electrolysis(PEMWE) and the alkaline anion exchange membrane fuel cells(AEMFCs)are also summarized.展开更多
Pt/WO3/C nanocomposites with parallel WO3 nanorods were synthesized and applied as the cathode catalyst for proton exchange membrane fuel cells （PEMFCs）. Electrochemical results and single cell tests show that an en...Pt/WO3/C nanocomposites with parallel WO3 nanorods were synthesized and applied as the cathode catalyst for proton exchange membrane fuel cells （PEMFCs）. Electrochemical results and single cell tests show that an enhanced activity for the oxygen reduction reaction （ORR） is obtained for the Pt/WO3/C catalyst compared with Pt/C. The higher catalytic activity might be ascribed to the improved Pt dispersion with smaller particle sizes. The Pt/WO3/C catalyst also exhibits a good electrochemical stability under potential cycling. Thus, the Pt/WO3/C catalyst can be used as a potential PEMFC cathode catalyst.展开更多
The nanofiber electrodes have been considered as promising candidates for commercial proton exchange membrane fuel cells due to their high catalyst utilization and enhanced mass transport efficiency.However,for the fi...The nanofiber electrodes have been considered as promising candidates for commercial proton exchange membrane fuel cells due to their high catalyst utilization and enhanced mass transport efficiency.However,for the first time our research determined that the nanofiber electrodes were restricted by the poor chemical stability of the polymer carriers.To gain further insight into the durability of nanofiber electrodes,both cyclic voltammetry aging tests and Fenton’s tests were conducted.Similar to previous reports,our research demonstrated that nanofiber electrodes showed remarkable stability in the cyclic voltammetry aging process.However,Fenton’s tests indicated that nanofibers in the electrodes would decompose easily while being attacked by reactive oxygen species such as HO·or HOO·,which greatly limits their practicability and reliability.The different performances under the two tests also demonstrated that the cyclic voltammetry aging protocols,which have been applied extensively,cannot well mirror the real operating conditions of fuel cells.展开更多
Autonomous systems are an emerging AI technology functioning without human intervention underpinned by the latest advances in intelligence,cognition,computer,and systems sciences.This paper explores the intelligent an...Autonomous systems are an emerging AI technology functioning without human intervention underpinned by the latest advances in intelligence,cognition,computer,and systems sciences.This paper explores the intelligent and mathematical foundations of autonomous systems.It focuses on structural and behavioral properties that constitute the intelligent power of autonomous systems.It explains how system intelligence aggregates from reflexive,imperative,adaptive intelligence to autonomous and cognitive intelligence.A hierarchical intelligence model(HIM)is introduced to elaborate the evolution of human and system intelligence as an inductive process.The properties of system autonomy are formally analyzed towards a wide range of applications in computational intelligence and systems engineering.Emerging paradigms of autonomous systems including brain-inspired systems,cognitive robots,and autonomous knowledge learning systems are described.Advances in autonomous systems will pave a way towards highly intelligent machines for augmenting human capabilities.展开更多
A method for the determination of trace mercury in water samples by hydride generation atomic absorption spectrophotometry after cloud point extraction was proposed in the present work. The effects of pH, concentratio...A method for the determination of trace mercury in water samples by hydride generation atomic absorption spectrophotometry after cloud point extraction was proposed in the present work. The effects of pH, concentration of surfactant, and equilibration time on cloud point extraction were discussed. The enhancement factor of 20 and the detection limit of 0.039 μg/L were obtained for mercury with relative standard deviation of 4.8% （n = 11）.展开更多
Zeolitic Imidazolate Framework-8(ZIF-8)material was prepared by chemical precipitation method.The microstructure and physical properties of the as-prepared samples were characterized by XRD,BET,FESEM and UV spectropho...Zeolitic Imidazolate Framework-8(ZIF-8)material was prepared by chemical precipitation method.The microstructure and physical properties of the as-prepared samples were characterized by XRD,BET,FESEM and UV spectrophotometer.The self-made four-channel measurement device was used to test the gas sensitivity of ZIF-8 material toward ethanol gas under photo-thermal synergistic excitation.The results showed that the sample was typical ZIF-8(E_(g)=4.96 eV)with a regular dodecahedron shape and the specific surface is up to 1793 m^(2)/g.The as-prepared ZIF-8 has a gas response value of 55.04 to 100 ppm ethanol at 75℃ and it shows good gas sensing selectivity and repeated stability.The excellent gas sensitivity can be attributed to the increase of free electron concentration in the ZIF-8 conduction band by photo-thermal synergistic excitation,and the large specific surface area of ZIF-8 material provides more active sites for gas-solid surface reaction.The reaction mechanism of ZIF-8 material under multi-field excitation was also discussed.展开更多
Objective: To evaluate the reliability and validity of the Chinese version of the Spiritual Needs Questionnaire with 27 items (SpNQ-Ch-27) for cancer patients.Methods: A total of 457 cancer patients in a tertiary hosp...Objective: To evaluate the reliability and validity of the Chinese version of the Spiritual Needs Questionnaire with 27 items (SpNQ-Ch-27) for cancer patients.Methods: A total of 457 cancer patients in a tertiary hospital in Xinjiang from March to July in 2017 were investigated by using the SpNQ-Ch-27 and convenient sampling method.They were recruited to validate the discrimination,reliability,and validity of the scale.According to the odd and even questionnaire numbers,data were divided into two groups to do exploratory factor analysis group and confirmatory factor analysis,respectively.Results: SpNQ-Ch-27 included 27 items and six factors,which were extracted by using factor analysis.It could explain 63.08% of the total variance.The total scores of each dimension and the SpNQ-Ch-27 were highly correlated,and the correlation coefficient was from 0.58 to 0.78.For the CFA,the overall fitting ideal was x2/df=2.00,RMSEA =0.07,IFI =0.93,NFI =0.86,CFI =0.92,TLI =0.90;Cronbach's α =0.90;the dimensions of Cronbach's α =0.63-0.95;split-half reliability was 0.82,dimensions were 0.68-0.95.Conclusion: SpNQ-Ch-27 is applicable for Chinese cancer patients with better validity and higher internal consistency,and it can be used as a tool to assess the spiritual needs of cancer patients.展开更多
Objective： To compare the feasibility and applicability of predicting the prognosis of patients using the Early Warning Score（MEWS） system and the Acute Physiology and Chronic Health Evaluation（APACHE Ⅱ） system ...Objective： To compare the feasibility and applicability of predicting the prognosis of patients using the Early Warning Score（MEWS） system and the Acute Physiology and Chronic Health Evaluation（APACHE Ⅱ） system in the Emergency Department.Methods： Using a prospective study method, the APACHE Ⅱ and MEWS data for 640 patients hospitalized in the Emergency Internal Medicine Department were collected. The prognoses, two scores to predict the corresponding prediction index of sensitivity, specificity and positive predictive value for the prognosis,the negative predictive value and the ROC curve for predicting the prognosis were analyzed for all patients.Results： In the prediction of the risk of mortality, the MEWS system had a high resolution. The MEWS area under the ROC curve was 0.93. The area under the ROC curve for the APACHE score was 0.79, and the difference was statistically significant（Z =4.348, P 〈 0.01）.Conclusions： Both the MEWS and APACHE Ⅱ systems can be used to determine the severity of emergency patients and have a certain predictive value for the patient＇s mortality risk. However, the MEWS system is simple and quick to operate, making it a useful supplement for APACHE Ⅱ score.展开更多
Sn-doped TiO2 nanoparticles with high surface area of 125.7 m2·g-1 are synthesized via a simple one-step hydrothermai method and explored as the cathode catalyst support for proton exchange membrane fuel cells.Th...Sn-doped TiO2 nanoparticles with high surface area of 125.7 m2·g-1 are synthesized via a simple one-step hydrothermai method and explored as the cathode catalyst support for proton exchange membrane fuel cells.The synthesized support materials are studied by X-ray diffraction analysis,energy dispersive X-ray spectroscopy and transmission electron microscopy.It is found that the conductivity has been greatly improved by the addition of 30 mol%Sn and Pt nanoparticles are well dispersed on Ti0.7Sn0.3O2 support with an average size of 2.44 run.Electrochemical studies show that the Ti0.7Sn0.3O2 nanoparticles have excellent electrochemical stability under a high potential compared to Vulcan XC-72.The as-synthesized Pt/Ti0.7Sn0.3O2 exhibits high and stable electrocatalytic activity for the oxygen reduction reaction.The Pt/Ti0.7Sn0.3O2 catalyst reserves most of its electrochemically active surface area（ECA）,and its half wave potential difference is 11 mV,which is lower than that of Pt/XC-72（36 mV） under 10 h potential hold at 1.4 V vs.NHE.In addition,the ECA degradation of Pt/Ti0.7Sn0.3O2is 1.9 times lower than commercial Pt/XC-72 under 500 potential cycles between 0.6 V and 1.2 V vs.NHE.Therefore,the as synthesized Pt/Ti0.7Sn0.3O2 can be considered as a promising alternative cathode,catalyst for proton exchange membrane fuel cells.展开更多
Objective:The objective is to assess the direct and indirect effects of nurses’organizational commitment(OC)on their work environment perceptions(WEP)and the role of the psychological contr act(PC).Methods:A cross‑se...Objective:The objective is to assess the direct and indirect effects of nurses’organizational commitment(OC)on their work environment perceptions(WEP)and the role of the psychological contr act(PC).Methods:A cross‑sectional quantitative study of 3047 registered nurses in four Chinese hospitals was conducted.The Essentials of Magnetism II(Chinese version),OC,and PC scales were used in the study,and the structural equation modeling was used to assess the connections among variables.Results:The results showed that OC was positively correlated with WEP(r=0.561,P<0.001),and PC was negatively correlated with the WEP(r=−0.717,P<0.001),and OC(r=−0.739,P<0.001).Nurses’PC played a strong mediating role between OC and WEP,accounting for 87.64%of the total effect.Besides,PC played an important role in creating a healthy work environment.Conclusions:The exploration of the relationships among WEP,PC,and OC provides new insights for hospital managers to build a better work environment for nurses,which is conducive to maintaining a stable nurse team and providing high‑quality nursing services for patients.展开更多
Clinical question What are the recommendations for the timing,dosage,and usage of corticosteroids during cytokine release syndrome(CRS)caused by chimeric antigen receptor(CAR)-T cell therapy for hematologic malignancies?
Myeloid-derived suppressor cells(MDSCs)are a heterogeneous population of immature cells and natural inhibitors of adaptive immunity.Intracellular metabolic changes in MDSCs exert a direct immunological influence on th...Myeloid-derived suppressor cells(MDSCs)are a heterogeneous population of immature cells and natural inhibitors of adaptive immunity.Intracellular metabolic changes in MDSCs exert a direct immunological influence on their suppressive activity.Our previous study demonstrated that high-dose dexamethasone(HD-DXM)corrected the functional impairment of MDSCs in immune thrombocytopenia(ITP);however,the MDSC population was not restored in nonresponders,and the mechanism remained unclear.In this study,altered mitochondrial physiology and reduced mitochondrial gene transcription were detected in MDSCs from HD-DXM nonresponders,accompanied by decreased levels of carnitine palmitoyltransferase-1(CPT-1),a rate-limiting enzyme in fatty acid oxidation(FAO).Blockade of FAO with a CPT-1 inhibitor abolished the immunosuppressive function of MDSCs in HD-DXM responders.We also report that MDSCs from ITP patients had lower expression of the glucocorticoid receptor(GR),which can translocate into mitochondria to regulate the transcription of mitochondrial DNA(mtDNA)as well as the level of oxidative phosphorylation.It was confirmed that the expression of CPT-1 and mtDNA-encoded genes was downregulated in GR-siRNA-treated murine MDSCs.Finally,by establishing murine models of active and passive ITP via adoptive transfer of DXM-modulated MDSCs,we confirmed that GR-silenced MDSCs failed to alleviate thrombocytopenia in mice with ITP.In conclusion,our study indicated that impaired aerobic metabolism in MDSCs participates in the pathogenesis of glucocorticoid resistance in ITP and that intact control of MDSC metabolism by GR contributes to the homeostatic regulation of immunosuppressive cell function.展开更多
Chimeric antigen receptor T-cell(CAR-T)therapy has greatly improved the disease remission rate and long-term survival rate of patients with relapsed/refractory hematological malignancies.[1-3]Currently,several commerc...Chimeric antigen receptor T-cell(CAR-T)therapy has greatly improved the disease remission rate and long-term survival rate of patients with relapsed/refractory hematological malignancies.[1-3]Currently,several commercial CAR-T products are available in the market and numerous CAR-T clinical trials have been conducted.Attention should be paid to the safety of CAR-T therapy.The main adverse effects of CAR-T therapy are cytokine release syndrome(CRS)and immune effector cell-associated neurotoxicity syndrome(ICANS).[4]展开更多
Immune thrombocytopenia(ITP)is an autoimmune disorder,in which megakaryocyte dysfunction caused by an autoimmune reaction can lead to thrombocytopenia,although the underlying mechanisms remain unclear.Here,we performe...Immune thrombocytopenia(ITP)is an autoimmune disorder,in which megakaryocyte dysfunction caused by an autoimmune reaction can lead to thrombocytopenia,although the underlying mechanisms remain unclear.Here,we performed single-cell transcriptome profiling of bone marrow CD34+hematopoietic stem and progenitor cells(HSPCs)to determine defects in megakaryopoiesis in ITP.Gene expression,cell-cell interactions,and transcriptional regulatory networks varied in HSPCs of ITP,particularly in immune cell progenitors.Differentially expressed gene(DEG)analysis indicated that there was an impaired megakaryopoiesis of ITP.Flow cytometry confirmed that the number of CD9+and HES1+cells from Lin−CD34+CD45RA−HSPCs decreased in ITP.Liquid culture assays demonstrated that CD9+Lin−CD34+CD45RA−HSPCs tended to differentiate into megakaryocytes;however,this tendency was not observed in ITP patients and more erythrocytes were produced.The percentage of megakaryocytes differentiated from CD9+Lin−CD34+CD45RA−HSPCs was 3-fold higher than that of the CD9−counterparts from healthy controls(HCs),whereas,in ITP patients,the percentage decreased to only 1/4th of that in the HCs and was comparable to that from the CD9−HSPCs.Additionally,when co-cultured with pre-B cells from ITP patients,the differentiation of CD9+Lin−CD34+CD45RA−HSPCs toward the megakaryopoietic lineage was impaired.Further analysis revealed that megakaryocytic progenitors(MkP)can be divided into seven subclusters with different gene expression patterns and functions.The ITP-associated DEGs were MkP subtype-specific,with most DEGs concentrated in the subcluster possessing dual functions of immunomodulation and platelet generation.This study comprehensively dissects defective hematopoiesis and provides novel insights regarding the pathogenesis of ITP.展开更多
In recent years,Fe-N-C catalyst is particularly attractive due to its high oxygen reduction reaction(ORR)activity and low cost for proton exchange membrane fuel cells(PEMFCs).However,the durability problems still pose...In recent years,Fe-N-C catalyst is particularly attractive due to its high oxygen reduction reaction(ORR)activity and low cost for proton exchange membrane fuel cells(PEMFCs).However,the durability problems still pose challenge to the application of Fe-N-C catalyst.Although considerable work has been done to investigate the degradation mechanisms of Fe-N-C catalyst,most of them are simply focused on the active-site decay,the carbon oxidation,and the demetalation problems.In fact,the 2e−pathway in the ORR process of Fe-N-C catalyst would result in the formation of H2O2,which is proved to be a key degradation source.In this paper,a new insight into the effect of potential on degradation of Fe-N-C catalyst was provided by quantifying the H2O2 intermediate.In this case,stability tests were conducted by the potential-static method in O2 saturated 0.1 mol/L HClO4.During the tests,H2O2 was quantified by rotating ring disk electrode(RRDE).The results show that compared with the loading voltage of 0.4 V,0.8 V,and 1.0 V,the catalysts being kept at 0.6 V exhibit a highest H2O2 yield.It is found that it is the combined effect of electrochemical oxidation and chemical oxidation(by aggressive radicals like H2O2/radicals)that triggered the highest H2O2 release rate,with the latter as the major cause.展开更多
Chronic stress impairs radial neural stem cell(rNSC)differentiation and adult hippocampal neurogenesis(AHN),whereas promoting AHN can increase stress resilience against depression.Therefore,investigating the mechanism...Chronic stress impairs radial neural stem cell(rNSC)differentiation and adult hippocampal neurogenesis(AHN),whereas promoting AHN can increase stress resilience against depression.Therefore,investigating the mechanism of neural differentiation and AHN is of great importance for developing antidepressant drugs.The nonpsychoactive phytocannabinoid cannabidiol(CBD)has been shown to be effective against depression.However,whether CBD can modulate rNSC differentiation and hippocampal neurogenesis is unknown.Here,by using the chronic restraint stress(CRS)mouse model,we showed that hippocampal rNSCs mostly differentiated into astrocytes under stress conditions.Moreover,transcriptome analysis revealed that the FoxO signaling pathway was involved in the regulation of this process.The administration of CBD rescued depressive-like symptoms in CRS mice and prevented rNSCs overactivation and differentiation into astrocyte,which was partly mediated by the modulation of the FoxO signaling pathway.These results revealed a previously unknown neural mechanism for neural differentiation and AHN in depression and provided mechanistic insights into the antidepressive effects of CBD.展开更多
Methotrexate,etoposide,dexamethasone,and pegaspargase(MESA)with sandwiched radiotherapy is known to be effective for early-stage extranodal natural killer/T-cell lymphoma,nasal type(NKTCL).We explored the efficacy and...Methotrexate,etoposide,dexamethasone,and pegaspargase(MESA)with sandwiched radiotherapy is known to be effective for early-stage extranodal natural killer/T-cell lymphoma,nasal type(NKTCL).We explored the efficacy and safety of reduced-intensity,non-intravenous etoposide,dexamethasone,and pegaspargase(ESA)with sandwiched radiotherapy.This multicenter,randomized,phase III trial enrolled patients aged between 14 and 70 years with newly diagnosed early-stage nasal NKTCL from 27 centers in China.Patients were randomly assigned(1:1)to receive ESA(pegaspargase 2,500 IU/m^(2)intramuscularly on day 1,etoposide 200 mg orally,and dexamethasone 40 mg orally on days 2–4)or MESA(methotrexate 1 g/m^(2)intravenously on day 1,etoposide 200 mg orally,and dexamethasone 40 mg orally on days 2–4,and pegaspargase 2,500 IU/m^(2)intramuscularly on day 5)regimen(four cycles),combined with sandwiched radiotherapy.展开更多
Immune thrombocytopenia(ITP)is an autoimmune disorder characterized by increased bleeding tendency and thrombocytopenia.The main mechanisms include the loss of immune tolerance,accelerated platelet destruction,impaire...Immune thrombocytopenia(ITP)is an autoimmune disorder characterized by increased bleeding tendency and thrombocytopenia.The main mechanisms include the loss of immune tolerance,accelerated platelet destruction,impaired bone marrow(BM)microenvironment,and decreased platelet production.1–5 The processes of megakaryocytopoiesis and thrombocytopoiesis occur within a complex BM microenvironment.Macrophages(MFs)are crucial regulators of normal hematopoiesis in the BM microenvironment,whereas very few studies focus on the effect of BM MFs on megakaryopoiesis,especially the MF polarization subsets in thrombocytopenic disease.Prolonged thrombocytopenia(PT)after hematopoietic stem cell transplantation is a strong risk factor for transplantation-related morbidity and mortality,and no standard treatment guideline exists.Meanwhile,PT,characterized by dysfunctional megakaryocyte(MK)maturation and thrombocytopenia,not only provides a paradigm for understanding the relationship between MK development and BM microenvironment but also an ideal disease model for studying thrombocytopenia。展开更多
基金financially supported by the National Basic Research Program of China (973 Program) (no. 2012CB215500)the National Key Technology Research and Development Program of China (no. 2015BAG06B00)+1 种基金Major Program of the National Natural Science Foundation of China (no. 61433013)National Natural Science Foundation of China (no. 21206012)
文摘Arc ion plating (AIP) is applied to form Ti/(Ti,Cr)N/CrN multilayer coating on the surface of 316L stainless steel (SS316L) as bipolar plates for proton exchange membrane fuel cells (PEMFCs). The characterizations of the coating are analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Interfacial contact resistance (ICR) between the coated sample and carbon paper is 4.9 m Omega cm(2) under 150 N/cm(2), which is much lower than that of the SS316L substrate. Potentiodynamic and potentiostatic tests are performed in the simulated PEMFC working conditions to investigate the corrosion behaviors of the coated sample. Superior anticorrosion performance is observed for the coated sample, whose corrosion current density is 0.12 mu A/cm(2). Surface morphology results after corrosion tests indicate that the substrate is well protected by the multilayer coating. Performances of the single cell with the multilayer coated SS316L bipolar plate are improved significantly compared with that of the cell with the uncoated SS316L bipolar plate, presenting a great potential for PEMFC application. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金supported by the National Key Research and Development Program of China(2016YFB0101207)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB06050303)the Natural Science Foundation of China(U1664259)
文摘Proton exchange membrane fuel cell(PEMFC) as a power supply device has attracted wide attention in China and abroad for its advantages of high energy density, energy conversion efficiency and zero pollution.With the vigorous support of China's national policy, research institutes and enterprises have carried out extensive and pragmatic work on the basic materials, key components, stacks, auxiliary systems of PEMFCs, as well as the hydrogen station construction in order to realize the wide application of hydrogen energy.PEMFC System and Engineering Research Center of DICP is one of the earliest players in the H2-PEMFCs field.Advances have been achieved in the fields of low-platinum contained catalysts,PEMs, high-efficiency MEAs, low-cost metal bipolar plates, low-temperature and impurity air environment adaptability, stacks and systems.This paper introduces recent progresses of H2-PEMFCs at DICP in key materials, components, stacks, systems and the applications.The engineering status of proton exchange membrane water electrolysis(PEMWE) and the alkaline anion exchange membrane fuel cells(AEMFCs)are also summarized.
基金financially supported by the National Natural Science Fundation of China(No.51125007)the National Basic Research Program(No.2012CB215500)
文摘Pt/WO3/C nanocomposites with parallel WO3 nanorods were synthesized and applied as the cathode catalyst for proton exchange membrane fuel cells （PEMFCs）. Electrochemical results and single cell tests show that an enhanced activity for the oxygen reduction reaction （ORR） is obtained for the Pt/WO3/C catalyst compared with Pt/C. The higher catalytic activity might be ascribed to the improved Pt dispersion with smaller particle sizes. The Pt/WO3/C catalyst also exhibits a good electrochemical stability under potential cycling. Thus, the Pt/WO3/C catalyst can be used as a potential PEMFC cathode catalyst.
基金National Key Point Research and Invention Program of the Thirteenth(Program Nos.2018YFB0105601 and 2017YFB0102801).
文摘The nanofiber electrodes have been considered as promising candidates for commercial proton exchange membrane fuel cells due to their high catalyst utilization and enhanced mass transport efficiency.However,for the first time our research determined that the nanofiber electrodes were restricted by the poor chemical stability of the polymer carriers.To gain further insight into the durability of nanofiber electrodes,both cyclic voltammetry aging tests and Fenton’s tests were conducted.Similar to previous reports,our research demonstrated that nanofiber electrodes showed remarkable stability in the cyclic voltammetry aging process.However,Fenton’s tests indicated that nanofibers in the electrodes would decompose easily while being attacked by reactive oxygen species such as HO·or HOO·,which greatly limits their practicability and reliability.The different performances under the two tests also demonstrated that the cyclic voltammetry aging protocols,which have been applied extensively,cannot well mirror the real operating conditions of fuel cells.
基金supported in part by the Department of National Defence’s Innovation for Defence Excellence and Security(IDEa S)Program,Canadathrough the Project of Auto Defence Towards Trustworthy Technologies for Autonomous Human-Machine Systems,NSERCthe IEEE SMC Society Technical Committee on Brain-Inspired Systems(TCBCS)。
文摘Autonomous systems are an emerging AI technology functioning without human intervention underpinned by the latest advances in intelligence,cognition,computer,and systems sciences.This paper explores the intelligent and mathematical foundations of autonomous systems.It focuses on structural and behavioral properties that constitute the intelligent power of autonomous systems.It explains how system intelligence aggregates from reflexive,imperative,adaptive intelligence to autonomous and cognitive intelligence.A hierarchical intelligence model(HIM)is introduced to elaborate the evolution of human and system intelligence as an inductive process.The properties of system autonomy are formally analyzed towards a wide range of applications in computational intelligence and systems engineering.Emerging paradigms of autonomous systems including brain-inspired systems,cognitive robots,and autonomous knowledge learning systems are described.Advances in autonomous systems will pave a way towards highly intelligent machines for augmenting human capabilities.
文摘A method for the determination of trace mercury in water samples by hydride generation atomic absorption spectrophotometry after cloud point extraction was proposed in the present work. The effects of pH, concentration of surfactant, and equilibration time on cloud point extraction were discussed. The enhancement factor of 20 and the detection limit of 0.039 μg/L were obtained for mercury with relative standard deviation of 4.8% （n = 11）.
基金supported by the National Natural Science Foundation of China(No.51864028)the Yunnan Province Science and Technology Major Project for Materials Genetic Engineering of Rare and Precious Metal(No.202002AB080001)+2 种基金the Yunnan Province Funds for Distinguished Young Scientists,(No.2019FJ005)the Science Research Foundation of Yunnan Provincial Education Department(No.2022J0441)the Sichuan Science and Technology Program(No.22QYCX0097)。
文摘Zeolitic Imidazolate Framework-8(ZIF-8)material was prepared by chemical precipitation method.The microstructure and physical properties of the as-prepared samples were characterized by XRD,BET,FESEM and UV spectrophotometer.The self-made four-channel measurement device was used to test the gas sensitivity of ZIF-8 material toward ethanol gas under photo-thermal synergistic excitation.The results showed that the sample was typical ZIF-8(E_(g)=4.96 eV)with a regular dodecahedron shape and the specific surface is up to 1793 m^(2)/g.The as-prepared ZIF-8 has a gas response value of 55.04 to 100 ppm ethanol at 75℃ and it shows good gas sensing selectivity and repeated stability.The excellent gas sensitivity can be attributed to the increase of free electron concentration in the ZIF-8 conduction band by photo-thermal synergistic excitation,and the large specific surface area of ZIF-8 material provides more active sites for gas-solid surface reaction.The reaction mechanism of ZIF-8 material under multi-field excitation was also discussed.
文摘Objective: To evaluate the reliability and validity of the Chinese version of the Spiritual Needs Questionnaire with 27 items (SpNQ-Ch-27) for cancer patients.Methods: A total of 457 cancer patients in a tertiary hospital in Xinjiang from March to July in 2017 were investigated by using the SpNQ-Ch-27 and convenient sampling method.They were recruited to validate the discrimination,reliability,and validity of the scale.According to the odd and even questionnaire numbers,data were divided into two groups to do exploratory factor analysis group and confirmatory factor analysis,respectively.Results: SpNQ-Ch-27 included 27 items and six factors,which were extracted by using factor analysis.It could explain 63.08% of the total variance.The total scores of each dimension and the SpNQ-Ch-27 were highly correlated,and the correlation coefficient was from 0.58 to 0.78.For the CFA,the overall fitting ideal was x2/df=2.00,RMSEA =0.07,IFI =0.93,NFI =0.86,CFI =0.92,TLI =0.90;Cronbach's α =0.90;the dimensions of Cronbach's α =0.63-0.95;split-half reliability was 0.82,dimensions were 0.68-0.95.Conclusion: SpNQ-Ch-27 is applicable for Chinese cancer patients with better validity and higher internal consistency,and it can be used as a tool to assess the spiritual needs of cancer patients.
基金supported by Pudong New Area Health System leadership program(No.PWRd2016-11)National Natural Science Foundation of China(No.81360231)
文摘Objective： To compare the feasibility and applicability of predicting the prognosis of patients using the Early Warning Score（MEWS） system and the Acute Physiology and Chronic Health Evaluation（APACHE Ⅱ） system in the Emergency Department.Methods： Using a prospective study method, the APACHE Ⅱ and MEWS data for 640 patients hospitalized in the Emergency Internal Medicine Department were collected. The prognoses, two scores to predict the corresponding prediction index of sensitivity, specificity and positive predictive value for the prognosis,the negative predictive value and the ROC curve for predicting the prognosis were analyzed for all patients.Results： In the prediction of the risk of mortality, the MEWS system had a high resolution. The MEWS area under the ROC curve was 0.93. The area under the ROC curve for the APACHE score was 0.79, and the difference was statistically significant（Z =4.348, P 〈 0.01）.Conclusions： Both the MEWS and APACHE Ⅱ systems can be used to determine the severity of emergency patients and have a certain predictive value for the patient＇s mortality risk. However, the MEWS system is simple and quick to operate, making it a useful supplement for APACHE Ⅱ score.
基金supported by the National High Technology Research and Development Program of China(863 Program,Grant No.2013AA110201)the National Basic Research Program of China(973 Program,Grant No.2012CB215500)the National Natural Science Foundations of China(Grant No.21203191)
文摘Sn-doped TiO2 nanoparticles with high surface area of 125.7 m2·g-1 are synthesized via a simple one-step hydrothermai method and explored as the cathode catalyst support for proton exchange membrane fuel cells.The synthesized support materials are studied by X-ray diffraction analysis,energy dispersive X-ray spectroscopy and transmission electron microscopy.It is found that the conductivity has been greatly improved by the addition of 30 mol%Sn and Pt nanoparticles are well dispersed on Ti0.7Sn0.3O2 support with an average size of 2.44 run.Electrochemical studies show that the Ti0.7Sn0.3O2 nanoparticles have excellent electrochemical stability under a high potential compared to Vulcan XC-72.The as-synthesized Pt/Ti0.7Sn0.3O2 exhibits high and stable electrocatalytic activity for the oxygen reduction reaction.The Pt/Ti0.7Sn0.3O2 catalyst reserves most of its electrochemically active surface area（ECA）,and its half wave potential difference is 11 mV,which is lower than that of Pt/XC-72（36 mV） under 10 h potential hold at 1.4 V vs.NHE.In addition,the ECA degradation of Pt/Ti0.7Sn0.3O2is 1.9 times lower than commercial Pt/XC-72 under 500 potential cycles between 0.6 V and 1.2 V vs.NHE.Therefore,the as synthesized Pt/Ti0.7Sn0.3O2 can be considered as a promising alternative cathode,catalyst for proton exchange membrane fuel cells.
文摘Objective:The objective is to assess the direct and indirect effects of nurses’organizational commitment(OC)on their work environment perceptions(WEP)and the role of the psychological contr act(PC).Methods:A cross‑sectional quantitative study of 3047 registered nurses in four Chinese hospitals was conducted.The Essentials of Magnetism II(Chinese version),OC,and PC scales were used in the study,and the structural equation modeling was used to assess the connections among variables.Results:The results showed that OC was positively correlated with WEP(r=0.561,P<0.001),and PC was negatively correlated with the WEP(r=−0.717,P<0.001),and OC(r=−0.739,P<0.001).Nurses’PC played a strong mediating role between OC and WEP,accounting for 87.64%of the total effect.Besides,PC played an important role in creating a healthy work environment.Conclusions:The exploration of the relationships among WEP,PC,and OC provides new insights for hospital managers to build a better work environment for nurses,which is conducive to maintaining a stable nurse team and providing high‑quality nursing services for patients.
基金supported by grants from the National Natural Science Foundation of China(Nos.82270233,81830004 and 82070168)National Natural Science Foundation of China Youth Science Foundation Project(No.82200246)+2 种基金Translational Research Grant of NCRCH(No.2020ZKZC04)National Key R&D Program of China(No.2021YFA1100800)Shanghai Municipal Health Commission(No.2020CXJQ02).
文摘Clinical question What are the recommendations for the timing,dosage,and usage of corticosteroids during cytokine release syndrome(CRS)caused by chimeric antigen receptor(CAR)-T cell therapy for hematologic malignancies?
基金This work was supported by grants from the National Natural Science Foundation of China(Nos.81900121,81770133,81973994,and 81770114)Major Research Plan of National Natural Science Foundation of China(No.91942306)+3 种基金Clinical Research Center of Shandong University(No.2020SDUCRCC009)Graduate Education Reform Project of Shandong University(No.XYJG2020141)State Key Clinical Specialty of China for Blood DisordersYoung Taishan Scholar Foundation of Shandong Province(No.tsqn201909175).
文摘Myeloid-derived suppressor cells(MDSCs)are a heterogeneous population of immature cells and natural inhibitors of adaptive immunity.Intracellular metabolic changes in MDSCs exert a direct immunological influence on their suppressive activity.Our previous study demonstrated that high-dose dexamethasone(HD-DXM)corrected the functional impairment of MDSCs in immune thrombocytopenia(ITP);however,the MDSC population was not restored in nonresponders,and the mechanism remained unclear.In this study,altered mitochondrial physiology and reduced mitochondrial gene transcription were detected in MDSCs from HD-DXM nonresponders,accompanied by decreased levels of carnitine palmitoyltransferase-1(CPT-1),a rate-limiting enzyme in fatty acid oxidation(FAO).Blockade of FAO with a CPT-1 inhibitor abolished the immunosuppressive function of MDSCs in HD-DXM responders.We also report that MDSCs from ITP patients had lower expression of the glucocorticoid receptor(GR),which can translocate into mitochondria to regulate the transcription of mitochondrial DNA(mtDNA)as well as the level of oxidative phosphorylation.It was confirmed that the expression of CPT-1 and mtDNA-encoded genes was downregulated in GR-siRNA-treated murine MDSCs.Finally,by establishing murine models of active and passive ITP via adoptive transfer of DXM-modulated MDSCs,we confirmed that GR-silenced MDSCs failed to alleviate thrombocytopenia in mice with ITP.In conclusion,our study indicated that impaired aerobic metabolism in MDSCs participates in the pathogenesis of glucocorticoid resistance in ITP and that intact control of MDSC metabolism by GR contributes to the homeostatic regulation of immunosuppressive cell function.
文摘Chimeric antigen receptor T-cell(CAR-T)therapy has greatly improved the disease remission rate and long-term survival rate of patients with relapsed/refractory hematological malignancies.[1-3]Currently,several commercial CAR-T products are available in the market and numerous CAR-T clinical trials have been conducted.Attention should be paid to the safety of CAR-T therapy.The main adverse effects of CAR-T therapy are cytokine release syndrome(CRS)and immune effector cell-associated neurotoxicity syndrome(ICANS).[4]
基金National Natural Science Foundation of China(82030005,91942306,82170124,81900122,82000126,82000122,and 81973994)Rongxiang Regenerative Medicine Foundation of Shandong University(2019SDRX-02)State Key Clinical Specialty of China for Hematological Diseases,and the Taishan Scholar of Shandong Province.
文摘Immune thrombocytopenia(ITP)is an autoimmune disorder,in which megakaryocyte dysfunction caused by an autoimmune reaction can lead to thrombocytopenia,although the underlying mechanisms remain unclear.Here,we performed single-cell transcriptome profiling of bone marrow CD34+hematopoietic stem and progenitor cells(HSPCs)to determine defects in megakaryopoiesis in ITP.Gene expression,cell-cell interactions,and transcriptional regulatory networks varied in HSPCs of ITP,particularly in immune cell progenitors.Differentially expressed gene(DEG)analysis indicated that there was an impaired megakaryopoiesis of ITP.Flow cytometry confirmed that the number of CD9+and HES1+cells from Lin−CD34+CD45RA−HSPCs decreased in ITP.Liquid culture assays demonstrated that CD9+Lin−CD34+CD45RA−HSPCs tended to differentiate into megakaryocytes;however,this tendency was not observed in ITP patients and more erythrocytes were produced.The percentage of megakaryocytes differentiated from CD9+Lin−CD34+CD45RA−HSPCs was 3-fold higher than that of the CD9−counterparts from healthy controls(HCs),whereas,in ITP patients,the percentage decreased to only 1/4th of that in the HCs and was comparable to that from the CD9−HSPCs.Additionally,when co-cultured with pre-B cells from ITP patients,the differentiation of CD9+Lin−CD34+CD45RA−HSPCs toward the megakaryopoietic lineage was impaired.Further analysis revealed that megakaryocytic progenitors(MkP)can be divided into seven subclusters with different gene expression patterns and functions.The ITP-associated DEGs were MkP subtype-specific,with most DEGs concentrated in the subcluster possessing dual functions of immunomodulation and platelet generation.This study comprehensively dissects defective hematopoiesis and provides novel insights regarding the pathogenesis of ITP.
基金The work was supported by the Thirteenth National Key Point Research and Invention Program(No.2016YFB0101302)。
文摘In recent years,Fe-N-C catalyst is particularly attractive due to its high oxygen reduction reaction(ORR)activity and low cost for proton exchange membrane fuel cells(PEMFCs).However,the durability problems still pose challenge to the application of Fe-N-C catalyst.Although considerable work has been done to investigate the degradation mechanisms of Fe-N-C catalyst,most of them are simply focused on the active-site decay,the carbon oxidation,and the demetalation problems.In fact,the 2e−pathway in the ORR process of Fe-N-C catalyst would result in the formation of H2O2,which is proved to be a key degradation source.In this paper,a new insight into the effect of potential on degradation of Fe-N-C catalyst was provided by quantifying the H2O2 intermediate.In this case,stability tests were conducted by the potential-static method in O2 saturated 0.1 mol/L HClO4.During the tests,H2O2 was quantified by rotating ring disk electrode(RRDE).The results show that compared with the loading voltage of 0.4 V,0.8 V,and 1.0 V,the catalysts being kept at 0.6 V exhibit a highest H2O2 yield.It is found that it is the combined effect of electrochemical oxidation and chemical oxidation(by aggressive radicals like H2O2/radicals)that triggered the highest H2O2 release rate,with the latter as the major cause.
基金This work was supported by the National Natural Science Foundation of China(Nos.21877060 and 31900824)the Postdoctoral Research Foundation of China(No.2019M651779).
文摘Chronic stress impairs radial neural stem cell(rNSC)differentiation and adult hippocampal neurogenesis(AHN),whereas promoting AHN can increase stress resilience against depression.Therefore,investigating the mechanism of neural differentiation and AHN is of great importance for developing antidepressant drugs.The nonpsychoactive phytocannabinoid cannabidiol(CBD)has been shown to be effective against depression.However,whether CBD can modulate rNSC differentiation and hippocampal neurogenesis is unknown.Here,by using the chronic restraint stress(CRS)mouse model,we showed that hippocampal rNSCs mostly differentiated into astrocytes under stress conditions.Moreover,transcriptome analysis revealed that the FoxO signaling pathway was involved in the regulation of this process.The administration of CBD rescued depressive-like symptoms in CRS mice and prevented rNSCs overactivation and differentiation into astrocyte,which was partly mediated by the modulation of the FoxO signaling pathway.These results revealed a previously unknown neural mechanism for neural differentiation and AHN in depression and provided mechanistic insights into the antidepressive effects of CBD.
基金supported by the Union for China Lymphoma Investigators,and funded by the Multicenter Clinical Research Project by Shanghai Jiao Tong University School of Medicine(DLY201601)the National Key R&D Program of China(2022YFC 2502600)+3 种基金the National Natural Science Foundation of China(82130004,81830007,82070204,and 81670176)Chang Jiang Scholars Program,Shanghai Municipal Education Commission Gaofeng Clinical Medicine Grant Support(20152206 and 20152208)the Clinical Research Plan of Shanghai Hospital Development Center(SHDC2020CR1032B)the Collaborative Innovation Center of Systems Biomedicine,and the Samuel Waxman Cancer Research Foundation.
文摘Methotrexate,etoposide,dexamethasone,and pegaspargase(MESA)with sandwiched radiotherapy is known to be effective for early-stage extranodal natural killer/T-cell lymphoma,nasal type(NKTCL).We explored the efficacy and safety of reduced-intensity,non-intravenous etoposide,dexamethasone,and pegaspargase(ESA)with sandwiched radiotherapy.This multicenter,randomized,phase III trial enrolled patients aged between 14 and 70 years with newly diagnosed early-stage nasal NKTCL from 27 centers in China.Patients were randomly assigned(1:1)to receive ESA(pegaspargase 2,500 IU/m^(2)intramuscularly on day 1,etoposide 200 mg orally,and dexamethasone 40 mg orally on days 2–4)or MESA(methotrexate 1 g/m^(2)intravenously on day 1,etoposide 200 mg orally,and dexamethasone 40 mg orally on days 2–4,and pegaspargase 2,500 IU/m^(2)intramuscularly on day 5)regimen(four cycles),combined with sandwiched radiotherapy.
文摘Immune thrombocytopenia(ITP)is an autoimmune disorder characterized by increased bleeding tendency and thrombocytopenia.The main mechanisms include the loss of immune tolerance,accelerated platelet destruction,impaired bone marrow(BM)microenvironment,and decreased platelet production.1–5 The processes of megakaryocytopoiesis and thrombocytopoiesis occur within a complex BM microenvironment.Macrophages(MFs)are crucial regulators of normal hematopoiesis in the BM microenvironment,whereas very few studies focus on the effect of BM MFs on megakaryopoiesis,especially the MF polarization subsets in thrombocytopenic disease.Prolonged thrombocytopenia(PT)after hematopoietic stem cell transplantation is a strong risk factor for transplantation-related morbidity and mortality,and no standard treatment guideline exists.Meanwhile,PT,characterized by dysfunctional megakaryocyte(MK)maturation and thrombocytopenia,not only provides a paradigm for understanding the relationship between MK development and BM microenvironment but also an ideal disease model for studying thrombocytopenia。
