Economical water electrolysis requires highly active non-noble electrocatalysts to overcome the sluggish kinetics of the two half-cell reactions,oxygen evolution reaction,and hydrogen evolution reaction.Although inten...Economical water electrolysis requires highly active non-noble electrocatalysts to overcome the sluggish kinetics of the two half-cell reactions,oxygen evolution reaction,and hydrogen evolution reaction.Although intensive efforts have been committed to achieve a hydrogen economy,the expensive noble metal-based catalysts remain under consideration.Therefore,the engineering of self-supported electrocatalysts prepared using a direct growth strategy on three-dimensional(3D)nickel foam(NF)as a conductive substrate has garnered significant interest.This is due to the large active surface area and 3D porous network offered by these electrocatalysts,which can enhance the synergistic eff ect between the catalyst and the substrate,as well as improve electrocatalytic performance.Hydrothermal-assisted growth,microwave heating,electrodeposition,and other physical methods(i.e.,chemical vapor deposition and plasma treatment)have been applied to NF to fabricate competitive electrocatalysts with low overpotential and high stability.In this review,recent advancements in the development of self-supported electrocatalysts on 3D NF are described.Finally,we provide future perspectives of self-supported electrode platforms in electrochemical water splitting.展开更多
This paper realizes the full-domain collaborative deployment of multiple interference sources of the global satellite navigation system(GNSS)and evaluates the deployment effect to enhance the ability to disturb the at...This paper realizes the full-domain collaborative deployment of multiple interference sources of the global satellite navigation system(GNSS)and evaluates the deployment effect to enhance the ability to disturb the attacker and the capability to defend the GNSS during navigation countermeasures.Key evaluation indicators for the jamming effect of GNSS suppressive and deceptive jamming sources are first created,their evaluation models are built,and their detection procedures are sorted out,as the basis for determining the deployment principles.The principles for collaboratively deploying multi-jamming sources are developed to obtain the deployment structures(including the required number,structures in demand,and corresponding positions)of three single interference sources required by collaboratively deploying.Accordingly,simulation and hardware-in-loop testing results are presented to determine a rational configuration of the collaborative deployment of multi-jamming sources in the set situation and further realize the full-domain deployment of an interference network from ground,air to space.Varied evaluation indices for the deployment effect are finally developed to evaluate the deployment effect of the proposed configuration and further verify its reliability and rationality.展开更多
Evapotranspiration(ET)is a crucial variable in the terrestrial water,carbon,and energy cycles.At present,a large number of multi source ET products exist.Due to sparse observations,however,great challenges exist in th...Evapotranspiration(ET)is a crucial variable in the terrestrial water,carbon,and energy cycles.At present,a large number of multi source ET products exist.Due to sparse observations,however,great challenges exist in the evaluation and integration of ET products in remote and complex areas such as the Tibetan Plateau(TP).In this paper,the applicability of the multiple collocation(MC)method over the TP is evaluated for the first time,and the uncertainty of multisource ET products(based on reanalysis,remote sensing,and land surface models)is further analyzed,which provides a theoretical basis for ET data fusion.The results show that 1)ET uncertainties quantified via the MC method are lower in RS-based ET products(5.95 vs.7.06 mm month^(-1))than in LSM ET products(10.22 vs.17.97 mm month^(-1))and reanalysis ET estimates(7.27 vs.12.26 mm month-1).2)A multisource evapotranspiration(MET)dataset is generated at a monthly temporal scale with a spatial resolution of 0.25°across the TP during 2005-15.MET has better performance than any individual product.3)Based on the fusion product,the total ET amount over the TP and its patterns of spatiotemporal variability are clearly identified.The annual total ET over the entire TP is approximately 380.60 mm.Additionally,an increasing trend of 1.59±0.85 mm yr^(-1)over the TP is shown during 2005-15.This study provides a basis for future studies on water and energy cycles and water resource management over the TP and surrounding regions.展开更多
●AIM:To evaluate the effectiveness and safety of early lens extraction during pars plana vitrectomy(PPV)for proliferative diabetic retinopathy(PDR)compared to those of PPV with subsequent cataract surgery.●METHODS:T...●AIM:To evaluate the effectiveness and safety of early lens extraction during pars plana vitrectomy(PPV)for proliferative diabetic retinopathy(PDR)compared to those of PPV with subsequent cataract surgery.●METHODS:This multicenter randomized controlled trial was conducted in three Chinese hospitals on patients with PDR,aged>45y,with mild cataracts.The participants were randomly assigned to the combined(PPV combined with simultaneously cataract surgery,i.e.,phacovitrectomy)or subsequent(PPV with subsequent cataract surgery 6mo later)group and followed up for 12mo.The primary outcome was the change in best-corrected visual acuity(BCVA)from baseline to 6mo,and the secondary outcomes included complication rates and medical expenses.●RESULTS:In total,129 patients with PDR were recruited and equally randomized(66 and 63 in the combined and subsequent groups respectively).The change in BCVA in the combined group[mean,36.90 letters;95%confidence interval(CI),30.35–43.45]was significantly better(adjusted difference,16.43;95%CI,8.77–24.08;P<0.001)than in the subsequent group(mean,22.40 letters;95%CI,15.55–29.24)6mo after the PPV,with no significant difference between the two groups at 12mo.The overall surgical risk of two sequential surgeries was significantly higher than that of the combined surgery for neovascular glaucoma(17.65%vs 3.77%,P=0.005).No significant differences were found in the photocoagulation spots,surgical time,and economic expenses between two groups.In the subsequent group,the duration of work incapacity(22.54±9.11d)was significantly longer(P<0.001)than that of the combined group(12.44±6.48d).●CONCLUSION:PDR patients aged over 45y with mild cataract can also benefit from early lens extraction during PPV with gratifying effectiveness,safety and convenience,compared to sequential surgeries.展开更多
CO impurity-induced catalyst deactivation has long been one of the biggest challenges in proton-exchange membrane fuel cells,with the poisoning phenomenon mainly attributed to the overly strong adsorption on the catal...CO impurity-induced catalyst deactivation has long been one of the biggest challenges in proton-exchange membrane fuel cells,with the poisoning phenomenon mainly attributed to the overly strong adsorption on the catalytic site.Here,we present a mechanistic study that overturns this understanding by using Rh-based single-atom catalysis centers as model catalysts.We precisely modulated the chelation structure of the Rh catalyst by coordinating Rh with C or N atoms,and probed the reaction mechanism by surface-enhanced Raman spectroscopy.Direct spectroscopic evidence for intermediates indicates that the reactivity of adsorbed OH^(*),rather than the adsorption strength of CO^(*),dictates the CO electrocatalytic oxidation behavior.The RhN_(4)sites,which adsorb the OH^(*)intermediate more weakly than RhC4 sites,showed prominent CO oxidation activity that not only far exceeded the traditional Pt/C but also the RhC4 sites with similar CO adsorption strength.From this study,it is clear that a paradigm shift in future research should be considered to rationally design high-performance CO electro-oxidation reaction catalysts by sufficiently considering the water-related reaction intermediate during catalysis.展开更多
Background:In this study,we analyzed the potential active components,related crucial targets and possible signaling pathway mechanisms of Alpiniae Oxyphyllae Fructus and Saposhnikoviae Radix(AOF-SR)herb pairs in the t...Background:In this study,we analyzed the potential active components,related crucial targets and possible signaling pathway mechanisms of Alpiniae Oxyphyllae Fructus and Saposhnikoviae Radix(AOF-SR)herb pairs in the treatment of diabetic kidney disease(DKD)using network pharmacology and verification experiments.Methods:The active compounds and potential targets of AOF-SR were derived from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform,The Encyclopedia of Traditional Chinese Medicine,and PubChem databases,and the potential therapeutic targets of DKD were derived from the OMIM,Drugbank,and DisGeNET databases.The“compounds-diseases-targets”network was constructed using Cytoscape 3.6.0.ClusterMaker functionality in Cytoscape is being used to screen important targets for AOF-SR treatment of DKD.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis of important targets were performed using DAVID database.In addition,according to the predicted results of network pharmacology,HK-2 cells were used to construct DKD model for verification experiment.HK-2 cells were divided into control group,high glucose(HG)group and AOF-SR(HG+AOF-SR)group to detect survival rate and expression of key proteins in NF-κB and PI3K/Akt signaling pathways.Results:A total of 38 compounds were selected from AOF-SR,of which 23 were Alpiniae Oxyphyllae Fructus and 15 were Saposhnikoviae Radix.Through enrichment analysis of 82 important targets,88 signaling pathways were identified;some of these pathways,such as the NF-κB,PI3K-Akt,IL-17,and JAK/STAT signaling pathways,regulate the pathological process of DKD.In verification experiment,the HK-2 cells survival rate was higher in the HG+AOF-SR group than in the HG group(P<0.05).Moreover,western blotting results showed that the expression levels of NF-κB,p-PI3K,and p-Akt in HG+AOF-SR group were significantly lower than those in HG group(P<0.05).Conclusion:Overall,this study revealed the active compounds,important targets and possible mechanisms of AOF-SR treatment for DKD,and conducted preliminary verification experiments on its correctness,provided novel insights into the treatment of DKD by AOF-SR.展开更多
AIM:To investigate the expression and significance of caudal-related homeobox transcription factor(Cdx2) in gastric carcinoma(GC) and precancerous lesions.METHODS:The expression of Cdx2 in GC,precancerous lesions and ...AIM:To investigate the expression and significance of caudal-related homeobox transcription factor(Cdx2) in gastric carcinoma(GC) and precancerous lesions.METHODS:The expression of Cdx2 in GC,precancerous lesions and normal gastric mucosa were detected using immunohistochemical method.Hematoxylin and eosin staining,alcian blue/periodic acid-schiff and high iron diamine/alcian blue staining were used to classify intestinal metaplasia(IM) and GC.RESULTS:Cdx2 was not detected in normal gastric mucosa.Cdx2 expression was detected in 87.1%(101/116) of IM,50%(36/72) of dysplasia and 48.2%(41/85) of GC.The Cdx2-expressing cells in IM were more prevalent than in dysplasia and carcinoma(P < 0.05).There was no relationship between Cdx2 expression and the classification of IM or the degree of dysplasia.Expression of Cdx2 was significantly higher in intestinal-type carcinoma than in diffuse and mixedtype carcinoma(P < 0.05).Positive expression of Cdx2was mainly found in moderately to well differentiated GC.There was a negative association between nuclear Cdx2 expression and lymph node metastasis and tumor,nodes,metastasis stage of GC(P < 0.05).The patients with Cdx2-positive expression showed a higher survival rate than those with Cdx2-negative expression(P = 0.038).Multivariate analysis revealed that the expression of Cdx2 and lymph node metastasis were independent prognostic indicators of GC(P < 0.05).CONCLUSION:Cdx2 may be closely related to IM and the intestinal-type GC and implicate better biological behavior and outcome.Cdx2 is useful for predicting the prognosis of GC.展开更多
Photocatalytic reduction of CO2 with H2 O to syngas is an effective way for producing high value-added chemical feedstocks such as methanol and light olefins in industry.Nevertheless,the precise control of CO/H2 ratio...Photocatalytic reduction of CO2 with H2 O to syngas is an effective way for producing high value-added chemical feedstocks such as methanol and light olefins in industry.Nevertheless,the precise control of CO/H2 ratio from photocatalytic CO2 reduction reaction still poses a great challenge for the further application.Herein,we prepared a series of highly efficient heterostructure based on highly dispersed palladium supported on ultrathin Co Al-layered double hydroxide(LDH).In conjunction with a Ru-complex sensitizer,the molar ratios of CO/H2 can be tuned from 1:0.74 to 1:3 under visible-light irradiation(λ>400 nm).More interestingly,the syngas can be obtained under light irradiation atλ>600 nm.Structure characterization and density functional theory calculations revealed that the remarkable catalytic activity can be due to the supported palladium,which improved the charge transfer efficiency.Meanwhile,more H atoms were used to generate H2 on the supported palladium for further tunable CO/H2 ratio.This work demonstrates a new strategy for harnessing abundant solar-energy to produce syngas from a CO2 feedstock.展开更多
Hydrogen production from formic acid decomposition(FAD)is a promising means of hydrogen energy storage and utilization in fuel cells.Development of efficient catalysts for dehydrogenation of formic acid is a challengi...Hydrogen production from formic acid decomposition(FAD)is a promising means of hydrogen energy storage and utilization in fuel cells.Development of efficient catalysts for dehydrogenation of formic acid is a challenging topic.The surface chemical and electronic structure of the active catalysis components is important in formic acid decomposition at room-temperature.Here,the pyrdinic-nitrogen doped catalysts from hyperbranched polyamide were prepared via in situ polymerization reaction process by using activated carbon as a support.Because of the introduction of the polymer,the particles of the catalysts were stabilized,and the average particle diameter was only 1.64 nm.Under mild conditions,the catalysts activities were evaluated for FAD.The optimized Pd-N30/C catalyst exhibited high performance achieving almost full conversion,with a turnover frequency of 3481 h^-1 at 30℃.展开更多
AP2/ERE-type transcription factors,as a type of plant-specific transcription factors,play a key role in plant biotic and abiotic stress.Meanwhile,they have been studied in many plants,but rarely in tomatoes.In this st...AP2/ERE-type transcription factors,as a type of plant-specific transcription factors,play a key role in plant biotic and abiotic stress.Meanwhile,they have been studied in many plants,but rarely in tomatoes.In this study,we performed a genome-wide analysis of the SlAP2/ERF gene family of tomato,and finally identified 29 SlAP2/ERF genes and divided them into different subfamilies.At the same time,its basic physical and chemical properties were analyzed.We also constructed phylogenetic trees with 30 Arabidopsis AP2/ERF proteins and 28 potatoes AP2/ERF proteins to ensure conservative homology between them.In addition,we mapped 29 SlAP2/ERF transcription factors on 10 different chromosomes,and identified 43 responsive plant hormones,responsive light signals,tissue-specific expression and stress response elements from 2000bp upstream of the promoter region,and we analyzed conserved motifs and gene structures of SlAP2/ERF.The tertiary structure of SlAP2/ERF protein was constructed by homology modeling,and the protein-protein interaction network was constructed based on Arabidopsis Thaliana.Finally,the expression pattern of tomato in different tissues was studied by using gene expression database,and the expression level of tomato under abiotic stress was detected by q-RT-PCR.These results provide comprehensive information for further study of the function of the SlAP2/ERF gene family.展开更多
Emerging technologies of wireless and mobile communication enable people to accumulate a large volume of time-stamped locations,which appear in the form of a continuous moving object trajectory.How to accurately predi...Emerging technologies of wireless and mobile communication enable people to accumulate a large volume of time-stamped locations,which appear in the form of a continuous moving object trajectory.How to accurately predict the uncertain mobility of objects becomes an important and challenging problem.Existing algorithms for trajectory prediction in moving objects databases mainly focus on identifying frequent trajectory patterns,and do not take account of the effect of essential dynamic environmental factors.In this study,a general schema for predicting uncertain trajectories of moving objects with dynamic environment awareness is presented,and the key techniques in trajectory prediction arc addressed in detail.In order to accurately predict the trajectories,a trajectory prediction algorithm based on continuous time Bayesian networks(CTBNs) is improved and applied,which takes dynamic environmental factors into full consideration.Experiments conducted on synthetic trajectory data verify the effectiveness of the improved algorithm,which also guarantees the time performance as well.展开更多
Uncertainty must be well addressed in transmission expansion planning(TEP)problem,and it significantly affects the reliability and cost-effectiveness of power systems.Owing to the complex operating environment of powe...Uncertainty must be well addressed in transmission expansion planning(TEP)problem,and it significantly affects the reliability and cost-effectiveness of power systems.Owing to the complex operating environment of power systems,it is crucial to consider different types of uncertainties during the planning stage.In this paper,a robust TEP model is proposed by considering multiple uncertainties and active load.Specifically,in this model,the uncertainties of wind power output and contingency probability are considered simultaneously.The uncertainties are described by scenario and interval,and the Benders decomposition technique is applied to solve the model.The feasibility and effectiveness of the proposed model are illustrated using the IEEE RTS and IEEE 118-node systems.展开更多
A sensitive and rapid high performance liquid chromatography-mass spectrometry(HPLC-MS)method was developed and validated for simultaneous quantifcation of ten steroid hormones,including estrogens,androgens,progestero...A sensitive and rapid high performance liquid chromatography-mass spectrometry(HPLC-MS)method was developed and validated for simultaneous quantifcation of ten steroid hormones,including estrogens,androgens,progesterones,and corticosteroids four classes of steroids.The following ten steroid hormones were analyzed:progesterone,21-deoxycortisol,estrone,4-androstenedione,testosterone,dihydro-testosterone,androstenone,dehydroepiandrosterone,corticosterone and cortisone.Stable deuterated isotopes were used as internal standards for quantifcation.Sample preparation with and without derivatization were performed after liquid-liquid extraction,and the corresponding results were compared according to sensitivity and selectivity.Hydroxylamine derivatization was found to improve the ionization efciency of the analytes for electrospray ionization MS analysis.The gradient of mobile phase and experimental parameters for HPLC separation were optimized.The lower limits of quantifcation were in the range of 0.05-5 ng mL^(−1) with wide linear range for the ten steroid hormones.The intra-day precision<11.1%and recovery of 84.5-120% with negligible matrix efect were achieved,where within the acceptance limits of the FDA guideline.Total HPLC-MS analysis time was 6 min.This method enables simultaneous quantifcation of steroids in human serum.It will be helpful for the serum steroid profling in order to understand various endocrinology diseases.展开更多
Noncovalent interactions between ligands and targeting proteins are essential for understanding molecular mechanisms of proteins.In this work,we investigated the interaction of Cytochrome c(Cyt c)with maltoligosacchar...Noncovalent interactions between ligands and targeting proteins are essential for understanding molecular mechanisms of proteins.In this work,we investigated the interaction of Cytochrome c(Cyt c)with maltoligosaccharides,namely maltose(Mal Ⅱ),maltotriose(Mal Ⅲ),maltotetraose(Mal Ⅳ),maltopentaose(Mal Ⅴ),maltohexaose(Mal Ⅵ)and maltoheptaose(Mal Ⅶ).Using electrospray ionization mass spetrometry(ESI-MS)assay,the 1:1 and 1:2 complexes formed by Cyt c with maltoligosaccharide ligand were observed.The corresponding association constants were calculated according to the deconvoluted spectra.The order of the relative binding affinities of the selected oligosaccharides with Cyt c were as MalⅢ>MalⅣ>MalⅡ>MalⅤ>MalⅥ>MalⅦ.The results indicated that the stability of noncovalent protein complexes was intimately correlated to the molecular structure of bound ligand.The relevant functional groups that could form H-bonds,electrostatic or hydrophobic forces with protein’s amino residues played an important role for the stability of protein complexes.In addition,the steric structure of ligand was also critical for an appropriate interaction with the binding pocket of proteins.展开更多
基金supported by The Chinese Academy of Sciences (CAS) President’s International Fellowship Initiative (No. 2023VCB0014)The National Natural Science Foundation of China (No. 52203284)Shenzhen Science and Technology Program (Nos. GJHZ20220913143801003 and RCBS20221008093057026)
文摘Economical water electrolysis requires highly active non-noble electrocatalysts to overcome the sluggish kinetics of the two half-cell reactions,oxygen evolution reaction,and hydrogen evolution reaction.Although intensive efforts have been committed to achieve a hydrogen economy,the expensive noble metal-based catalysts remain under consideration.Therefore,the engineering of self-supported electrocatalysts prepared using a direct growth strategy on three-dimensional(3D)nickel foam(NF)as a conductive substrate has garnered significant interest.This is due to the large active surface area and 3D porous network offered by these electrocatalysts,which can enhance the synergistic eff ect between the catalyst and the substrate,as well as improve electrocatalytic performance.Hydrothermal-assisted growth,microwave heating,electrodeposition,and other physical methods(i.e.,chemical vapor deposition and plasma treatment)have been applied to NF to fabricate competitive electrocatalysts with low overpotential and high stability.In this review,recent advancements in the development of self-supported electrocatalysts on 3D NF are described.Finally,we provide future perspectives of self-supported electrode platforms in electrochemical water splitting.
基金the National Natural Science Foundation of China(Grant No.42174047 and No.42174036)the National Science Foundation Project for Outstanding Youth(No.42104034).
文摘This paper realizes the full-domain collaborative deployment of multiple interference sources of the global satellite navigation system(GNSS)and evaluates the deployment effect to enhance the ability to disturb the attacker and the capability to defend the GNSS during navigation countermeasures.Key evaluation indicators for the jamming effect of GNSS suppressive and deceptive jamming sources are first created,their evaluation models are built,and their detection procedures are sorted out,as the basis for determining the deployment principles.The principles for collaboratively deploying multi-jamming sources are developed to obtain the deployment structures(including the required number,structures in demand,and corresponding positions)of three single interference sources required by collaboratively deploying.Accordingly,simulation and hardware-in-loop testing results are presented to determine a rational configuration of the collaborative deployment of multi-jamming sources in the set situation and further realize the full-domain deployment of an interference network from ground,air to space.Varied evaluation indices for the deployment effect are finally developed to evaluate the deployment effect of the proposed configuration and further verify its reliability and rationality.
基金funded by the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(Grant No.2019QZKK0103)National Natural Science Foundation of China(Grant Nos.41875031,42230610,41522501,41275028)CLIMATE-Pan-TPE in the framework of the ESA-MOST Dragon 5 Programme(Grant ID 58516)。
文摘Evapotranspiration(ET)is a crucial variable in the terrestrial water,carbon,and energy cycles.At present,a large number of multi source ET products exist.Due to sparse observations,however,great challenges exist in the evaluation and integration of ET products in remote and complex areas such as the Tibetan Plateau(TP).In this paper,the applicability of the multiple collocation(MC)method over the TP is evaluated for the first time,and the uncertainty of multisource ET products(based on reanalysis,remote sensing,and land surface models)is further analyzed,which provides a theoretical basis for ET data fusion.The results show that 1)ET uncertainties quantified via the MC method are lower in RS-based ET products(5.95 vs.7.06 mm month^(-1))than in LSM ET products(10.22 vs.17.97 mm month^(-1))and reanalysis ET estimates(7.27 vs.12.26 mm month-1).2)A multisource evapotranspiration(MET)dataset is generated at a monthly temporal scale with a spatial resolution of 0.25°across the TP during 2005-15.MET has better performance than any individual product.3)Based on the fusion product,the total ET amount over the TP and its patterns of spatiotemporal variability are clearly identified.The annual total ET over the entire TP is approximately 380.60 mm.Additionally,an increasing trend of 1.59±0.85 mm yr^(-1)over the TP is shown during 2005-15.This study provides a basis for future studies on water and energy cycles and water resource management over the TP and surrounding regions.
文摘●AIM:To evaluate the effectiveness and safety of early lens extraction during pars plana vitrectomy(PPV)for proliferative diabetic retinopathy(PDR)compared to those of PPV with subsequent cataract surgery.●METHODS:This multicenter randomized controlled trial was conducted in three Chinese hospitals on patients with PDR,aged>45y,with mild cataracts.The participants were randomly assigned to the combined(PPV combined with simultaneously cataract surgery,i.e.,phacovitrectomy)or subsequent(PPV with subsequent cataract surgery 6mo later)group and followed up for 12mo.The primary outcome was the change in best-corrected visual acuity(BCVA)from baseline to 6mo,and the secondary outcomes included complication rates and medical expenses.●RESULTS:In total,129 patients with PDR were recruited and equally randomized(66 and 63 in the combined and subsequent groups respectively).The change in BCVA in the combined group[mean,36.90 letters;95%confidence interval(CI),30.35–43.45]was significantly better(adjusted difference,16.43;95%CI,8.77–24.08;P<0.001)than in the subsequent group(mean,22.40 letters;95%CI,15.55–29.24)6mo after the PPV,with no significant difference between the two groups at 12mo.The overall surgical risk of two sequential surgeries was significantly higher than that of the combined surgery for neovascular glaucoma(17.65%vs 3.77%,P=0.005).No significant differences were found in the photocoagulation spots,surgical time,and economic expenses between two groups.In the subsequent group,the duration of work incapacity(22.54±9.11d)was significantly longer(P<0.001)than that of the combined group(12.44±6.48d).●CONCLUSION:PDR patients aged over 45y with mild cataract can also benefit from early lens extraction during PPV with gratifying effectiveness,safety and convenience,compared to sequential surgeries.
基金Jilin Province Science and Technology Development Program,Grant/Award Numbers:20180101030JC,20190201270JC,20200201001JCNational Natural Science Foundation of China,Grant/Award Numbers:21633008,21673221,21875243,U1601211+1 种基金Research Innovation Fund,Grant/Award Number:DNL202010Special Funds for Guiding Local Scientific and Technological Development by the Central Government,Grant/Award Number:2020JH6/10500021。
文摘CO impurity-induced catalyst deactivation has long been one of the biggest challenges in proton-exchange membrane fuel cells,with the poisoning phenomenon mainly attributed to the overly strong adsorption on the catalytic site.Here,we present a mechanistic study that overturns this understanding by using Rh-based single-atom catalysis centers as model catalysts.We precisely modulated the chelation structure of the Rh catalyst by coordinating Rh with C or N atoms,and probed the reaction mechanism by surface-enhanced Raman spectroscopy.Direct spectroscopic evidence for intermediates indicates that the reactivity of adsorbed OH^(*),rather than the adsorption strength of CO^(*),dictates the CO electrocatalytic oxidation behavior.The RhN_(4)sites,which adsorb the OH^(*)intermediate more weakly than RhC4 sites,showed prominent CO oxidation activity that not only far exceeded the traditional Pt/C but also the RhC4 sites with similar CO adsorption strength.From this study,it is clear that a paradigm shift in future research should be considered to rationally design high-performance CO electro-oxidation reaction catalysts by sufficiently considering the water-related reaction intermediate during catalysis.
基金the National Natural Science Foundation of China(grant No.82160897,82205087)Hainan Provincial Natural Science Foundation of China(grant No.820RC635)+1 种基金Scientific Research Foundation of Hainan Medical University(grant No.HYPY201924,HYPY2020037)Hainan Medical University 2020 National Innovation and Entrepreneurship Program for College Students(grant No.202011810006).
文摘Background:In this study,we analyzed the potential active components,related crucial targets and possible signaling pathway mechanisms of Alpiniae Oxyphyllae Fructus and Saposhnikoviae Radix(AOF-SR)herb pairs in the treatment of diabetic kidney disease(DKD)using network pharmacology and verification experiments.Methods:The active compounds and potential targets of AOF-SR were derived from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform,The Encyclopedia of Traditional Chinese Medicine,and PubChem databases,and the potential therapeutic targets of DKD were derived from the OMIM,Drugbank,and DisGeNET databases.The“compounds-diseases-targets”network was constructed using Cytoscape 3.6.0.ClusterMaker functionality in Cytoscape is being used to screen important targets for AOF-SR treatment of DKD.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis of important targets were performed using DAVID database.In addition,according to the predicted results of network pharmacology,HK-2 cells were used to construct DKD model for verification experiment.HK-2 cells were divided into control group,high glucose(HG)group and AOF-SR(HG+AOF-SR)group to detect survival rate and expression of key proteins in NF-κB and PI3K/Akt signaling pathways.Results:A total of 38 compounds were selected from AOF-SR,of which 23 were Alpiniae Oxyphyllae Fructus and 15 were Saposhnikoviae Radix.Through enrichment analysis of 82 important targets,88 signaling pathways were identified;some of these pathways,such as the NF-κB,PI3K-Akt,IL-17,and JAK/STAT signaling pathways,regulate the pathological process of DKD.In verification experiment,the HK-2 cells survival rate was higher in the HG+AOF-SR group than in the HG group(P<0.05).Moreover,western blotting results showed that the expression levels of NF-κB,p-PI3K,and p-Akt in HG+AOF-SR group were significantly lower than those in HG group(P<0.05).Conclusion:Overall,this study revealed the active compounds,important targets and possible mechanisms of AOF-SR treatment for DKD,and conducted preliminary verification experiments on its correctness,provided novel insights into the treatment of DKD by AOF-SR.
基金Supported by The Natural Science Foundation of Anhui Province,No. 090413118
文摘AIM:To investigate the expression and significance of caudal-related homeobox transcription factor(Cdx2) in gastric carcinoma(GC) and precancerous lesions.METHODS:The expression of Cdx2 in GC,precancerous lesions and normal gastric mucosa were detected using immunohistochemical method.Hematoxylin and eosin staining,alcian blue/periodic acid-schiff and high iron diamine/alcian blue staining were used to classify intestinal metaplasia(IM) and GC.RESULTS:Cdx2 was not detected in normal gastric mucosa.Cdx2 expression was detected in 87.1%(101/116) of IM,50%(36/72) of dysplasia and 48.2%(41/85) of GC.The Cdx2-expressing cells in IM were more prevalent than in dysplasia and carcinoma(P < 0.05).There was no relationship between Cdx2 expression and the classification of IM or the degree of dysplasia.Expression of Cdx2 was significantly higher in intestinal-type carcinoma than in diffuse and mixedtype carcinoma(P < 0.05).Positive expression of Cdx2was mainly found in moderately to well differentiated GC.There was a negative association between nuclear Cdx2 expression and lymph node metastasis and tumor,nodes,metastasis stage of GC(P < 0.05).The patients with Cdx2-positive expression showed a higher survival rate than those with Cdx2-negative expression(P = 0.038).Multivariate analysis revealed that the expression of Cdx2 and lymph node metastasis were independent prognostic indicators of GC(P < 0.05).CONCLUSION:Cdx2 may be closely related to IM and the intestinal-type GC and implicate better biological behavior and outcome.Cdx2 is useful for predicting the prognosis of GC.
基金National Key R&D Program of China(2020YFB1506800)the National Natural Science Foundation of China(21633008,U1601211,21733004)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA21090400)the Jilin Province Science and Technology Development Program(20190201300JC,20170520150JH,20200201001JC)Dalian National Laboratory for Clean Energy(DNL),CAS,the Research Innovation Fund(grant DNL202010)for financial supports。
基金supported by the Fundamental Research Funds for the Central Universities(XK1802-6,XK1902,XK1803-05,12060093063,2312018RC07)the National Natural Science Foundation of China(U1707603,21878008,21625101,20190816)。
文摘Photocatalytic reduction of CO2 with H2 O to syngas is an effective way for producing high value-added chemical feedstocks such as methanol and light olefins in industry.Nevertheless,the precise control of CO/H2 ratio from photocatalytic CO2 reduction reaction still poses a great challenge for the further application.Herein,we prepared a series of highly efficient heterostructure based on highly dispersed palladium supported on ultrathin Co Al-layered double hydroxide(LDH).In conjunction with a Ru-complex sensitizer,the molar ratios of CO/H2 can be tuned from 1:0.74 to 1:3 under visible-light irradiation(λ>400 nm).More interestingly,the syngas can be obtained under light irradiation atλ>600 nm.Structure characterization and density functional theory calculations revealed that the remarkable catalytic activity can be due to the supported palladium,which improved the charge transfer efficiency.Meanwhile,more H atoms were used to generate H2 on the supported palladium for further tunable CO/H2 ratio.This work demonstrates a new strategy for harnessing abundant solar-energy to produce syngas from a CO2 feedstock.
基金supported by the National Natural Science Foundation of China (21633008, 21733004, and 21603216)Jilin Province Science and Technology Development Program (20180101030JC)+2 种基金the Hundred Talents Program of Chinese Academy of Sciencesthe Recruitment Program of Foreign Experts (WQ20122200077)RFBR (18-53-53025)
文摘Hydrogen production from formic acid decomposition(FAD)is a promising means of hydrogen energy storage and utilization in fuel cells.Development of efficient catalysts for dehydrogenation of formic acid is a challenging topic.The surface chemical and electronic structure of the active catalysis components is important in formic acid decomposition at room-temperature.Here,the pyrdinic-nitrogen doped catalysts from hyperbranched polyamide were prepared via in situ polymerization reaction process by using activated carbon as a support.Because of the introduction of the polymer,the particles of the catalysts were stabilized,and the average particle diameter was only 1.64 nm.Under mild conditions,the catalysts activities were evaluated for FAD.The optimized Pd-N30/C catalyst exhibited high performance achieving almost full conversion,with a turnover frequency of 3481 h^-1 at 30℃.
基金the National Natural Science Foundation of China(31560663,32060401).
文摘AP2/ERE-type transcription factors,as a type of plant-specific transcription factors,play a key role in plant biotic and abiotic stress.Meanwhile,they have been studied in many plants,but rarely in tomatoes.In this study,we performed a genome-wide analysis of the SlAP2/ERF gene family of tomato,and finally identified 29 SlAP2/ERF genes and divided them into different subfamilies.At the same time,its basic physical and chemical properties were analyzed.We also constructed phylogenetic trees with 30 Arabidopsis AP2/ERF proteins and 28 potatoes AP2/ERF proteins to ensure conservative homology between them.In addition,we mapped 29 SlAP2/ERF transcription factors on 10 different chromosomes,and identified 43 responsive plant hormones,responsive light signals,tissue-specific expression and stress response elements from 2000bp upstream of the promoter region,and we analyzed conserved motifs and gene structures of SlAP2/ERF.The tertiary structure of SlAP2/ERF protein was constructed by homology modeling,and the protein-protein interaction network was constructed based on Arabidopsis Thaliana.Finally,the expression pattern of tomato in different tissues was studied by using gene expression database,and the expression level of tomato under abiotic stress was detected by q-RT-PCR.These results provide comprehensive information for further study of the function of the SlAP2/ERF gene family.
基金supported by the National Natural Science Foundation of China (Nos.61100045,61165013,61003142,60902023,and 61171096)the China Postdoctoral Science Foundation (Nos.20090461346,201104697)+3 种基金the Youth Foundation for Humanities and Social Sciences of Ministry of Education of China (No.10YJCZH117)the Fundamental Research Funds for the Central Universities (Nos.SWJTU09CX035,SWJTU11ZT08)Zhejiang Provincial Natural Science Foundation of China (Nos.Y1100589,Y1080123)the Natural Science Foundation of Ningbo,China (No.2011A610175)
文摘Emerging technologies of wireless and mobile communication enable people to accumulate a large volume of time-stamped locations,which appear in the form of a continuous moving object trajectory.How to accurately predict the uncertain mobility of objects becomes an important and challenging problem.Existing algorithms for trajectory prediction in moving objects databases mainly focus on identifying frequent trajectory patterns,and do not take account of the effect of essential dynamic environmental factors.In this study,a general schema for predicting uncertain trajectories of moving objects with dynamic environment awareness is presented,and the key techniques in trajectory prediction arc addressed in detail.In order to accurately predict the trajectories,a trajectory prediction algorithm based on continuous time Bayesian networks(CTBNs) is improved and applied,which takes dynamic environmental factors into full consideration.Experiments conducted on synthetic trajectory data verify the effectiveness of the improved algorithm,which also guarantees the time performance as well.
基金supported by a project of the State Grid Shandong Electric Power Company(52062520000Q)the National Key Research and Development Program of China(2019YFE0118400).
文摘Uncertainty must be well addressed in transmission expansion planning(TEP)problem,and it significantly affects the reliability and cost-effectiveness of power systems.Owing to the complex operating environment of power systems,it is crucial to consider different types of uncertainties during the planning stage.In this paper,a robust TEP model is proposed by considering multiple uncertainties and active load.Specifically,in this model,the uncertainties of wind power output and contingency probability are considered simultaneously.The uncertainties are described by scenario and interval,and the Benders decomposition technique is applied to solve the model.The feasibility and effectiveness of the proposed model are illustrated using the IEEE RTS and IEEE 118-node systems.
基金National Natural Science Foundation of China(Grant No.21275167)the Natural Science Foundation of Hubei Province(Grant No.2014CFA025)the Preferred Research Foundation for the Returned Overseas Scholars from Ministry of Human Resources and Social Security of the People’s Republic of China for financial support.
文摘A sensitive and rapid high performance liquid chromatography-mass spectrometry(HPLC-MS)method was developed and validated for simultaneous quantifcation of ten steroid hormones,including estrogens,androgens,progesterones,and corticosteroids four classes of steroids.The following ten steroid hormones were analyzed:progesterone,21-deoxycortisol,estrone,4-androstenedione,testosterone,dihydro-testosterone,androstenone,dehydroepiandrosterone,corticosterone and cortisone.Stable deuterated isotopes were used as internal standards for quantifcation.Sample preparation with and without derivatization were performed after liquid-liquid extraction,and the corresponding results were compared according to sensitivity and selectivity.Hydroxylamine derivatization was found to improve the ionization efciency of the analytes for electrospray ionization MS analysis.The gradient of mobile phase and experimental parameters for HPLC separation were optimized.The lower limits of quantifcation were in the range of 0.05-5 ng mL^(−1) with wide linear range for the ten steroid hormones.The intra-day precision<11.1%and recovery of 84.5-120% with negligible matrix efect were achieved,where within the acceptance limits of the FDA guideline.Total HPLC-MS analysis time was 6 min.This method enables simultaneous quantifcation of steroids in human serum.It will be helpful for the serum steroid profling in order to understand various endocrinology diseases.
基金supported by the National Natural Science Foundation of China(Grant No.21675176)the Natural Science Foundation of Hubei Province(Grant No.2014CFA025)the Preferred Research Foundation for the Returned Overseas Scholars from Ministry of Human Resources and Social Security of the People’s Republic of China(Grant No.BZY14036)for financial supports.
文摘Noncovalent interactions between ligands and targeting proteins are essential for understanding molecular mechanisms of proteins.In this work,we investigated the interaction of Cytochrome c(Cyt c)with maltoligosaccharides,namely maltose(Mal Ⅱ),maltotriose(Mal Ⅲ),maltotetraose(Mal Ⅳ),maltopentaose(Mal Ⅴ),maltohexaose(Mal Ⅵ)and maltoheptaose(Mal Ⅶ).Using electrospray ionization mass spetrometry(ESI-MS)assay,the 1:1 and 1:2 complexes formed by Cyt c with maltoligosaccharide ligand were observed.The corresponding association constants were calculated according to the deconvoluted spectra.The order of the relative binding affinities of the selected oligosaccharides with Cyt c were as MalⅢ>MalⅣ>MalⅡ>MalⅤ>MalⅥ>MalⅦ.The results indicated that the stability of noncovalent protein complexes was intimately correlated to the molecular structure of bound ligand.The relevant functional groups that could form H-bonds,electrostatic or hydrophobic forces with protein’s amino residues played an important role for the stability of protein complexes.In addition,the steric structure of ligand was also critical for an appropriate interaction with the binding pocket of proteins.
