Flag leaf angle is one of the key target traits in high yield wheat breeding.A smaller flag leaf angle reduces shading and enables plants to grow at a higher density,which increases yield.Here we identified a mutant,j...Flag leaf angle is one of the key target traits in high yield wheat breeding.A smaller flag leaf angle reduces shading and enables plants to grow at a higher density,which increases yield.Here we identified a mutant,je0407,with an 84.34%-89.35%smaller flag leaf angle compared with the wild type.The mutant also had an abnormal lamina joint and no ligule or auricle.Genetic analysis indicated that the ligule was controlled by two recessive genes,which were mapped to chromosomes 2AS and 2DL.The mutant allele on chromosome 2AS was named Tafla1b,and it was fine mapped to a 1 Mb physical interval.The mutant allele on chr.2DL was identified as Taspl8b,a novel allele of TaSPL8 with a missense mutation in the second exon,which was used to develop a cleaved amplified polymorphic sequence marker.F3 and F4 lines derived from crosses between Jing411 and je0407 were genotyped to investigate interactions between the Tafla1b and Taspl8b alleles.Plants with the Tafla1b/Taspl8a genotype had 58.41%-82.76%smaller flag leaf angles,6.4%-24.9%shorter spikes,and a greater spikelet density(0.382 more spikelets per cm)compared with the wild type.Plants with the Tafla1a/Taspl8b genotype had 52.62%-82.24%smaller flag leaf angles and no differences in plant height or spikelet density compared with the wild type.Tafla1b/Taspl8b plants produced erect leaves with an abnormal lamina joint.The two alleles had dosage effects on ligule formation and flag leaf angle,but no significant effect on thousand-grain weight.The mutant alleles provide novel resources for improvement of wheat plant architecture.展开更多
Mesocarp color is an important agronomic trait of Cucurbita maxima and is determined mainly by the contents and compositions of the carotenoids.The two inbred lines with significant differences in fruit flesh color we...Mesocarp color is an important agronomic trait of Cucurbita maxima and is determined mainly by the contents and compositions of the carotenoids.The two inbred lines with significant differences in fruit flesh color were used in the study,the orange’312-1’and white’98-2’.Changes in seven carotenoid contents and compositions in the flesh of fruit produced by inbred lines’312-1’and’98-2’were analyzed during fruit development.The expression of eight key carotenoid biosynthesis genes in the fruit flesh were investigated during five fruit development stage in two inbred lines.As the flesh color intensified,the orange flesh color of’312-1’was determined mainly by the increased contents of lutein,β-carotene and zeaxanthin and the lack of carotenoid accumulation led to the formation of white flesh in’98-2’fruit.The expression of the LCY-e and CHYb genes was significantly stronger in’312-1’than in’98-2’,and their expression was strongly correlated with lutein andβ-carotene contents during fruit development.This study provides a deep understanding of the molecular mechanism of carotenoid biosynthesis in fruit flesh and provides a basis for additional studies on the highly refined improvement of squash quality.展开更多
发热伴血小板减少综合征(severe fever with thrombocytopenia syndrome,SFTS)是一种新发传染病,主要通过蜱虫叮咬传播,其病原体为发热伴血小板减少综合征病毒(severe fever with thrombocytopenia syndrome virus,SFTSV)。人际传播引发...发热伴血小板减少综合征(severe fever with thrombocytopenia syndrome,SFTS)是一种新发传染病,主要通过蜱虫叮咬传播,其病原体为发热伴血小板减少综合征病毒(severe fever with thrombocytopenia syndrome virus,SFTSV)。人际传播引发的SFTS聚集性疫情在国内外均有报道,人们重点关注了人际传播的感染途径,然而SFTS聚集性疫情和病毒基因型之间的相关性研究却未见报道。本文主要报道了2022~2023年河南省信阳市发生的两起SFTS聚集性疫情,探讨了SFTSV出现人际传播感染的可能途径,并对SFTS聚集性疫情与病毒基因型进行了关联分析。通过4例确诊患者的病毒序列分析,发现两起聚集性疫情中的2组SFTSV分别聚集在隶属于不同基因型的两个分支。将本研究病毒序列与GenBank中获得的SFTS聚集性疫情报道过的病毒序列进行系统发育分析,进一步发现人际传播病例报道的SFTSV涉及3种基因型,提示SFTS聚集性疫情的发生可能和病毒基因型无明显关联。本研究表明血液接触感染可能是SFTS聚集性疫情发生的主要传播途径,为揭示SFTS聚集性疫情的人际传播链提供了遗传学证据,为SFTS的人际传播防控提供了科学数据支撑。展开更多
Catalytic ethane dehydrogenation(EDH) to ethylene over Pt-based catalysts has received increasing interests in recent years as it is a potential alternative route to conventional steam cracking. However, the catalysts...Catalytic ethane dehydrogenation(EDH) to ethylene over Pt-based catalysts has received increasing interests in recent years as it is a potential alternative route to conventional steam cracking. However, the catalysts used in this reaction often suffer from rapid deactivation due to serious coke deposition and metal sintering. Herein, we reported the effects of Zn modification on the stability of Pt/Al2 O3 for EDH.The Zn-modified sample(PtZn2/Al2 O3) exhibits stable ethane conversion(20%) with over 95% ethylene selectivity. More importantly, it exhibits a significantly low deactivation rate of only 0.003 h-1 at 600 °C for70 h, which surpasses most of previously reported catalysts. Detailed characterizations including in situ FT-IR, ethylene adsorption microcalorimetry, and HAADF-STEM etc. reveal that Zn modifier reduces the number of Lewis acid sites on the catalyst surface. Moreover, it could modify Pt sites and preferentially cover the step sites, which decrease surface energy and retard the sintering of Pt particle, then prohibiting the further dehydrogenation of ethylene to ethylidyne. Consequently, the good stability is realized due to anti-sintering and the decrease of coke formation on the Pt Zn2/Al2 O3 catalyst.展开更多
Faced with the continuous occurrence of coal and gas outburst(hereinafter referred to as“outburst”)disasters,as a main controlling factor in the evolution process of an outburst,for gas pressure,it is still unclear ...Faced with the continuous occurrence of coal and gas outburst(hereinafter referred to as“outburst”)disasters,as a main controlling factor in the evolution process of an outburst,for gas pressure,it is still unclear about the phased characteristics of the coupling process with in situ stress,which induce coal damage and instability.Therefore,in the work based on the mining stress paths induced by typical outburst accidents,the gradual and sudden change of three-dimensional stress is taken as the background for the mechanical reconstruction of the disaster process.Then the true triaxial physical experiments are conducted on the damage and instability of coal containing gas under multiple stress paths.Finally,the response characterization between coal damage and gas pressure has been clarified,revealing the mechanism of action of gas pressure during the initial failure of coals.And the main controlling mechanism during the outburst process is elucidated in the coupling process of in situ stress with gas pressure.The results show that during the process of stress loading and unloading,the original gas pressure enters the processes of strengthening and weakening the action ability successively.And the strengthening effect continues to the period of large-scale destruction of coals.The mechanical process of gas pressure during the initial failure of coals can be divided into three stages:the enhancement of strengthening action ability,the decrease of strengthening action ability,and the weakening action ability.The entire process is implemented by changing the dominant action of in situ stress into the dominant action of gas pressure.The failure strength of coals is not only affected by its original mechanical strength,but also by the stress loading and unloading paths,showing a particularly significant effect.Three stages can be divided during outburst inoculation process.That is,firstly,the coals suffer from initial damage through the dominant action of in situ stress with synergy of gas pressure;secondly,the coals with spallation of structural division are generated through the dominant action of gas pressure with synergy of in situ stress,accompanied by further fragmentation;and finally,the fractured coals suffer from fragmentation and pulverization with the gas pressure action.Accordingly,the final broken coals are ejected out with the gas action,initiating an outburst.The research results can provide a new perspective for deepening the understanding of coal and gas outburst mechanism,laying a theoretical foundation for the innovation of outburst prevention and control technologies.展开更多
Thermochemical two-step CO_(2) splitting is a potential approach that fixes the sustainable resource into transportable liquid fuels.However,the harsh CO_(2) splitting conditions,the limited oxygen release kinetics an...Thermochemical two-step CO_(2) splitting is a potential approach that fixes the sustainable resource into transportable liquid fuels.However,the harsh CO_(2) splitting conditions,the limited oxygen release kinetics and capacity of metal oxides block further promoted the CO yield and solar-to-fuel energy efficiency.Here,we propose a different carbon cycle assisted by Ni/La_(2)O_(3) via coupling methane decomposition with thermochemical CO_(2) splitting,replacing conventional metal oxides cycle.Superior performance was demonstrated with methane conversion reached around 94%with almost pure H_(2) generation.Encouragingly,CO_(2) conversion of 98%and CO yield of 6.9 mmol g^(-1) derived from CO_(2) were achieved,with peak CO evolution rate(402 mL min^(-1) g^(-1))of orders of magnitude higher than that in metal oxide process and outstanding thermodynamic solar-to-fuel energy efficiency(55.5%vs.18.5%).This was relevant to the synergistic activation of La_(2)O_(3) and Ni for CO_(2) in carbon cycle,thus improving CO_(2) splitting reaction with carbon species.展开更多
Objective:This study aims to evaluate the morphology and function of the aortic valve after transcatheter closure of ventricular septal defect(VSD)with aortic valve prolapse(AVP)abased on clinical and radiological out...Objective:This study aims to evaluate the morphology and function of the aortic valve after transcatheter closure of ventricular septal defect(VSD)with aortic valve prolapse(AVP)abased on clinical and radiological outcomes.Methods:From January 2013 to November 2014,164 consecutive patients(97 males,59.1%)with VSD and AVP were treated by transcatheter closure.The patients were divided into the mild AVP group(n=63),moderate AVP group(n=89)and severe AVP group(n=12).The clinical and radiological outcomes of these patients were analyzed retrospectively.Results:In total,146(89.0%)patients were successfully treated with VSD occluders,including 59/63(93.7%)with mild AVP,80/89(89.9%)with moderate AVP and 7/12(58.3%)with severe AVP.The degree of AVP was ameliorated or disappeared in 39(26.7%)patients,and remained unchanged in 103(70.5%)patients after the intervention.In the 35 patients who initially had trivial-to-moderate aortic regurgitation(AR),the degree of AR was ameliorated or disappeared in 25(71.4%)patients,aggravated from trivial to mild AR in 1(2.9%)patient,and remained unchanged in 9(25.7%)patients.In 111 patients without AR,1(0.9%)patient had mild AR and 24(21.6%)patients had trivial AR after intervention.The depth and width of the prolapsed aortic valve decreased after transcatheter closure of VSD in all three groups.During the 70-month(range,54–77)follow-up period,no patients with AVP and AR needed an aortic valve intervention.Conclusions:Transcatheter closure of VSD with AVP is feasible.The morphology and function of the prolapsed aortic valve improved and remained stable for a long period after intervention.展开更多
Natural polyamine is an ideal antitumor drug carrier because of the great requirement difference between cancer cells and normal cells. Previous data demonstrated that many cytotoxic drugs conjugated with natural or s...Natural polyamine is an ideal antitumor drug carrier because of the great requirement difference between cancer cells and normal cells. Previous data demonstrated that many cytotoxic drugs conjugated with natural or synthetic polyamines have potent antitumor effects. Up to now, the antitumor mechanism of conjugates of naphthalimides with polyamine remains poorly understood in human colon cancer cells. The aim of this study is to evaluate the effect of MINS (a novel naph-thalimide-polyamine conjugate) and mechanism of MINS in human colon cancer cells. Mitochondrial toxicity, which was generated by ROS from mitochondria electron transport chain, might be a major factor in MINS-inducted apoptosis. Our data also demonstrated that MINS-mediated cell apoptosis depend on p53 status, for MINS induced Caco-2 cells (p53 null) only necrosis but not apoptosis. Furthermore, the apoptotic effect of MINS is stronger than that of Amonafide, the parent drug of MINS. Our data suggested that the MINS-mediated cell apoptosis depend on p53 in human colon cancer cells.展开更多
Arsenic trioxide(ATO)has been identified as an effective treatment for acute promyelocytic leukemia(APL)but is much less effective against solid tumors such as hepatocellular carcinoma(HCC).In the search for ways to e...Arsenic trioxide(ATO)has been identified as an effective treatment for acute promyelocytic leukemia(APL)but is much less effective against solid tumors such as hepatocellular carcinoma(HCC).In the search for ways to enhance its therapeutic efficacy against solid tumors,we have examined its use in combination with a novel derivative ofβ-elemene,N-(β-elemene-13-yl)tryptophan methyl ester(ETME).Here we report the effects of the combination on cell viability,apoptosis,the cell cycle and mitochondria membrane potential(MMP)in HCC SMMC-7721 cells.We found that the two compounds acted synergistically to enhance antiproliferative activity and apoptosis.The combination also decreased the MMP,down-regulated Bcl-2 and pro-proteins of the caspase family,and up-regulated Bax and BID,all of which were reversed by the p53 inhibitor,pifithrin-α.In addition,the combination induced cell cycle arrest at the G2/M phase and reduced tumor volume and weight in an xenograft model of nude mice.Overall,the results suggest that ETME in combination with ATO may be useful in the treatment of HCC patients particularly those unresponsive to ATO alone.展开更多
During embryogenesis,hematopoietic stem progenitor cells(HSPCs)are believed to be derived from hemogenic endothelial cells(HECs).Moreover,arterial feature is proposed to be a prerequisite for HECs to generate HSPCs wi...During embryogenesis,hematopoietic stem progenitor cells(HSPCs)are believed to be derived from hemogenic endothelial cells(HECs).Moreover,arterial feature is proposed to be a prerequisite for HECs to generate HSPCs with lymphoid potential.Although the molecular basis of hematopoietic stem cell-competent HECs has been delicately elucidated within the embryo proper,the functional and molecular characteristics of HECs in the extraembryonic yolk sac(YS)remain largely unresolved.In this study,we initially identified six molecularly different endothelial populations in the midgestational YS through integrated analysis of several single-cell RNA sequencing(scRNA-seq)datasets and validated the arterial vasculature distribution of Gja5+ECs using a Gja5-EGFP reporter mouse model.Further,we explored the hemogenic potential of different EC populations based on their Gja5-EGFP and CD44 expression levels.The hemogenic potential was ubiquitously detected in spatiotemporally different vascular beds on embryonic days(E)8.5–E9.5 and gradually concentrated in CD44-positive ECs from E10.0.Unexpectedly,B-lymphoid potential was detected in the YS ECs as early as E8.5 regardless of their arterial features.Furthermore,the capacity for generating hematopoietic progenitors with in vivo lymphoid potential was found in nonarterial as well as arterial YS ECs on E10.0–E10.5.Importantly,the distinct identities of E10.0–E10.5 HECs between YS and intraembryonic caudal region were revealed by further scRNA-seq analysis.Cumulatively,these findings extend our knowledge regarding the hemogenic potential of ECs from anatomically and molecularly different vascular beds,providing a theoretical basis for better understanding the sources of HSPCs during mammalian development.展开更多
A series of genistein-polyamine conjugates(4a–4h) were designed, synthesized and evaluated as multi-functional anti-Alzheimer agents. The results showed that these compounds had significant cholinesterases(Ch Es) inh...A series of genistein-polyamine conjugates(4a–4h) were designed, synthesized and evaluated as multi-functional anti-Alzheimer agents. The results showed that these compounds had significant cholinesterases(Ch Es) inhibitory activity. Compound 4b exhibited the strongest inhibition to acetylcholinesterase(ACh E) with an IC_(50) value of 2.75 μmol/L, which was better than that of rivastigmine(5.60 μmol/L). Lineweaver–Burk plot and molecular modeling study showed that compound 4b targeted both the catalytic active site(CAS) and the peripheral anionic site(PAS) of ACh E. Besides, compound 4b showed potent metal-chelating ability. In addition, it was found that 4a–4h did not affect Hep G-2 cell viability at the concentration of 10 μmol/L.展开更多
A series of novel 1,2,3-triazole-quinazoline derivatives were synthesized in five steps starting from anthranila- mide by conventional methods. All the title compounds 10a-10r were evaluated for cytotoxic activity aga...A series of novel 1,2,3-triazole-quinazoline derivatives were synthesized in five steps starting from anthranila- mide by conventional methods. All the title compounds 10a-10r were evaluated for cytotoxic activity against four human cancer cell lines (MGC-803, EC-109, MCF-7 and HGC-27) using MTT assay in vitro. Some of the synthe- sized compounds exhibited moderate to potent activity against tested cancer cell lines. Among them, compounds 10h and 10q exhibited excellent growth inhibition against HGC-27 and compound 10m also possessed excellent ac- tivity against MCF-7, with IC50 values less than 1 μmol/L. Especially, compound 10h was more cytotoxic than 5-fluorouracil against all tested four human cancer cell lines.展开更多
Chalcopyrite Cu(In,Ga)Se_(2)(CIGS) thin films deposited in a low-temperature process(450℃) usually produce fine grains and poor crystallinity. Herein, different Ag treatment processes, which can decrease the melting ...Chalcopyrite Cu(In,Ga)Se_(2)(CIGS) thin films deposited in a low-temperature process(450℃) usually produce fine grains and poor crystallinity. Herein, different Ag treatment processes, which can decrease the melting temperature and enlarge band gap of the CIGS films, were employed to enhance the quality of thin films in a low-temperature deposition process. It is demonstrated that both the Ag precursor and Ag surface treatment process can heighten the crystallinity of CIGS films and the device efficiency. The former is more obvious than the latter. Furthermore, the Urbach energy is also reduced with Ag doping. This work aims to provide a feasible Ag-doping process for the high-quality CIGS films in a low-temperature process.展开更多
Disruption of the mitochondrial quality surveillance(MQS)system contributes to mitochondrial dysfunction in diabetic cardiomyopathy(DCM).In this study,we observed that cardiac expression of phosphoglycerate mutase 5(P...Disruption of the mitochondrial quality surveillance(MQS)system contributes to mitochondrial dysfunction in diabetic cardiomyopathy(DCM).In this study,we observed that cardiac expression of phosphoglycerate mutase 5(PGAM5),a mitochondrial Ser/Thr protein phosphatase,is upregulated in mice with streptozotocin-induced DCM.Notably,DCM-related cardiac structural and functional deficits were negated in cardiomyocyte-specific Pgam5 knockout(Pgam5^(CKO))mice.Hyperglycemic stress impaired adenosine triphosphate production,reduced respiratory activity,and prolonged mitochondrial permeability transition pore opening in acutely isolated neonatal cardiomyocytes from control Pgam5^(f/f) mice,and these effects were markedly prevented in cardiomyocytes from Pgam5^(CKO) mice.Likewise,three main MQS-governed processes—namely,mitochondrial fission/fusion cycling,mitophagy,and biogenesis—were disrupted by hyperglycemia in Pgam5^(f/f),but not in Pgam5^(CKO),cardiomyocytes.On the basis of bioinformatics prediction of interaction between PGAM5 and prohibitin 2(PHB2),an inner mitochondrial membrane-associated scaffolding protein,co-immunoprecipitation,and immunoblot assays demonstrated that PGAM5 dephosphorylates PHB2 on Ser91.Transfection of cardiomyocytes with phosphodefective or phosphomimetic Ser91 mutants of PHB2 confirmed a critical role for PGAM5-mediated dephosphorylation of PHB2 in mitochondrial dysfunction associated with hyperglycemic stress.Furthermore,knockin mice expressing phosphomimetic PHB2^(S91D) were resistant to diabetes-induced cardiac dysfunction.Our findings highlight the PGAM-PHB2 axis as a novel and critical regulator of mitochondrial dysfunction in DCM.展开更多
基金supported by the National Key Research and Development Project of China(2022YFD1200700)the Crop Varietal Improvement and Insect Pests Control by Nuclear Radiation,Innovation Program of Chinese Academy of Agricultural Sciences,and the China Agriculture Research System(CARS-03).
文摘Flag leaf angle is one of the key target traits in high yield wheat breeding.A smaller flag leaf angle reduces shading and enables plants to grow at a higher density,which increases yield.Here we identified a mutant,je0407,with an 84.34%-89.35%smaller flag leaf angle compared with the wild type.The mutant also had an abnormal lamina joint and no ligule or auricle.Genetic analysis indicated that the ligule was controlled by two recessive genes,which were mapped to chromosomes 2AS and 2DL.The mutant allele on chromosome 2AS was named Tafla1b,and it was fine mapped to a 1 Mb physical interval.The mutant allele on chr.2DL was identified as Taspl8b,a novel allele of TaSPL8 with a missense mutation in the second exon,which was used to develop a cleaved amplified polymorphic sequence marker.F3 and F4 lines derived from crosses between Jing411 and je0407 were genotyped to investigate interactions between the Tafla1b and Taspl8b alleles.Plants with the Tafla1b/Taspl8a genotype had 58.41%-82.76%smaller flag leaf angles,6.4%-24.9%shorter spikes,and a greater spikelet density(0.382 more spikelets per cm)compared with the wild type.Plants with the Tafla1a/Taspl8b genotype had 52.62%-82.24%smaller flag leaf angles and no differences in plant height or spikelet density compared with the wild type.Tafla1b/Taspl8b plants produced erect leaves with an abnormal lamina joint.The two alleles had dosage effects on ligule formation and flag leaf angle,but no significant effect on thousand-grain weight.The mutant alleles provide novel resources for improvement of wheat plant architecture.
基金the National Key Research and Development Program of China(Grant No.2018YFD0100706)。
文摘Mesocarp color is an important agronomic trait of Cucurbita maxima and is determined mainly by the contents and compositions of the carotenoids.The two inbred lines with significant differences in fruit flesh color were used in the study,the orange’312-1’and white’98-2’.Changes in seven carotenoid contents and compositions in the flesh of fruit produced by inbred lines’312-1’and’98-2’were analyzed during fruit development.The expression of eight key carotenoid biosynthesis genes in the fruit flesh were investigated during five fruit development stage in two inbred lines.As the flesh color intensified,the orange flesh color of’312-1’was determined mainly by the increased contents of lutein,β-carotene and zeaxanthin and the lack of carotenoid accumulation led to the formation of white flesh in’98-2’fruit.The expression of the LCY-e and CHYb genes was significantly stronger in’312-1’than in’98-2’,and their expression was strongly correlated with lutein andβ-carotene contents during fruit development.This study provides a deep understanding of the molecular mechanism of carotenoid biosynthesis in fruit flesh and provides a basis for additional studies on the highly refined improvement of squash quality.
文摘发热伴血小板减少综合征(severe fever with thrombocytopenia syndrome,SFTS)是一种新发传染病,主要通过蜱虫叮咬传播,其病原体为发热伴血小板减少综合征病毒(severe fever with thrombocytopenia syndrome virus,SFTSV)。人际传播引发的SFTS聚集性疫情在国内外均有报道,人们重点关注了人际传播的感染途径,然而SFTS聚集性疫情和病毒基因型之间的相关性研究却未见报道。本文主要报道了2022~2023年河南省信阳市发生的两起SFTS聚集性疫情,探讨了SFTSV出现人际传播感染的可能途径,并对SFTS聚集性疫情与病毒基因型进行了关联分析。通过4例确诊患者的病毒序列分析,发现两起聚集性疫情中的2组SFTSV分别聚集在隶属于不同基因型的两个分支。将本研究病毒序列与GenBank中获得的SFTS聚集性疫情报道过的病毒序列进行系统发育分析,进一步发现人际传播病例报道的SFTSV涉及3种基因型,提示SFTS聚集性疫情的发生可能和病毒基因型无明显关联。本研究表明血液接触感染可能是SFTS聚集性疫情发生的主要传播途径,为揭示SFTS聚集性疫情的人际传播链提供了遗传学证据,为SFTS的人际传播防控提供了科学数据支撑。
基金supported by the National Natural Science Foundation of China (NNSFC 21573232, 21576251, 21676269, 21878283)the Strategic Priority Research Program of Chinese Academy of Sciences Grant No. XDB17000000+2 种基金National Key Projects for Fundamental Research and Development of China (2016YFA0202801)The Youth Innovation Promotion Association CAS (2017223)Department of Science and Technology of Liaoning province under contract of 2015020086-101。
文摘Catalytic ethane dehydrogenation(EDH) to ethylene over Pt-based catalysts has received increasing interests in recent years as it is a potential alternative route to conventional steam cracking. However, the catalysts used in this reaction often suffer from rapid deactivation due to serious coke deposition and metal sintering. Herein, we reported the effects of Zn modification on the stability of Pt/Al2 O3 for EDH.The Zn-modified sample(PtZn2/Al2 O3) exhibits stable ethane conversion(20%) with over 95% ethylene selectivity. More importantly, it exhibits a significantly low deactivation rate of only 0.003 h-1 at 600 °C for70 h, which surpasses most of previously reported catalysts. Detailed characterizations including in situ FT-IR, ethylene adsorption microcalorimetry, and HAADF-STEM etc. reveal that Zn modifier reduces the number of Lewis acid sites on the catalyst surface. Moreover, it could modify Pt sites and preferentially cover the step sites, which decrease surface energy and retard the sintering of Pt particle, then prohibiting the further dehydrogenation of ethylene to ethylidyne. Consequently, the good stability is realized due to anti-sintering and the decrease of coke formation on the Pt Zn2/Al2 O3 catalyst.
基金This work was financially supported by the National Natural Science Foundation of China(No.52104236)the Fundamental Research Funds for the Central Universities(No.22CX06018A)the China Postdoctoral Science Foundation(No.2020M672177).
文摘Faced with the continuous occurrence of coal and gas outburst(hereinafter referred to as“outburst”)disasters,as a main controlling factor in the evolution process of an outburst,for gas pressure,it is still unclear about the phased characteristics of the coupling process with in situ stress,which induce coal damage and instability.Therefore,in the work based on the mining stress paths induced by typical outburst accidents,the gradual and sudden change of three-dimensional stress is taken as the background for the mechanical reconstruction of the disaster process.Then the true triaxial physical experiments are conducted on the damage and instability of coal containing gas under multiple stress paths.Finally,the response characterization between coal damage and gas pressure has been clarified,revealing the mechanism of action of gas pressure during the initial failure of coals.And the main controlling mechanism during the outburst process is elucidated in the coupling process of in situ stress with gas pressure.The results show that during the process of stress loading and unloading,the original gas pressure enters the processes of strengthening and weakening the action ability successively.And the strengthening effect continues to the period of large-scale destruction of coals.The mechanical process of gas pressure during the initial failure of coals can be divided into three stages:the enhancement of strengthening action ability,the decrease of strengthening action ability,and the weakening action ability.The entire process is implemented by changing the dominant action of in situ stress into the dominant action of gas pressure.The failure strength of coals is not only affected by its original mechanical strength,but also by the stress loading and unloading paths,showing a particularly significant effect.Three stages can be divided during outburst inoculation process.That is,firstly,the coals suffer from initial damage through the dominant action of in situ stress with synergy of gas pressure;secondly,the coals with spallation of structural division are generated through the dominant action of gas pressure with synergy of in situ stress,accompanied by further fragmentation;and finally,the fractured coals suffer from fragmentation and pulverization with the gas pressure action.Accordingly,the final broken coals are ejected out with the gas action,initiating an outburst.The research results can provide a new perspective for deepening the understanding of coal and gas outburst mechanism,laying a theoretical foundation for the innovation of outburst prevention and control technologies.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB17020100)the National Key R&D Program of China(2016YFA0202-801)+1 种基金the National Natural Science Foundation of China(NSFC)grants(21676269,21706254,21878283,22022814)the Dalian Institute of Chemical Physics,CAS(DICP I201916)。
文摘Thermochemical two-step CO_(2) splitting is a potential approach that fixes the sustainable resource into transportable liquid fuels.However,the harsh CO_(2) splitting conditions,the limited oxygen release kinetics and capacity of metal oxides block further promoted the CO yield and solar-to-fuel energy efficiency.Here,we propose a different carbon cycle assisted by Ni/La_(2)O_(3) via coupling methane decomposition with thermochemical CO_(2) splitting,replacing conventional metal oxides cycle.Superior performance was demonstrated with methane conversion reached around 94%with almost pure H_(2) generation.Encouragingly,CO_(2) conversion of 98%and CO yield of 6.9 mmol g^(-1) derived from CO_(2) were achieved,with peak CO evolution rate(402 mL min^(-1) g^(-1))of orders of magnitude higher than that in metal oxide process and outstanding thermodynamic solar-to-fuel energy efficiency(55.5%vs.18.5%).This was relevant to the synergistic activation of La_(2)O_(3) and Ni for CO_(2) in carbon cycle,thus improving CO_(2) splitting reaction with carbon species.
基金This study was reviewed and approved by the Institutional Review Board of Guangdong Province People’s Hospital(Guangzhou,Guangdong,China)(No.GDREC2020213H)This study was supported by National Key R&D Program of China(Grant No.2016YFC1100305)Sanming Medical Project of China(Grant No.SZSM201612057).
文摘Objective:This study aims to evaluate the morphology and function of the aortic valve after transcatheter closure of ventricular septal defect(VSD)with aortic valve prolapse(AVP)abased on clinical and radiological outcomes.Methods:From January 2013 to November 2014,164 consecutive patients(97 males,59.1%)with VSD and AVP were treated by transcatheter closure.The patients were divided into the mild AVP group(n=63),moderate AVP group(n=89)and severe AVP group(n=12).The clinical and radiological outcomes of these patients were analyzed retrospectively.Results:In total,146(89.0%)patients were successfully treated with VSD occluders,including 59/63(93.7%)with mild AVP,80/89(89.9%)with moderate AVP and 7/12(58.3%)with severe AVP.The degree of AVP was ameliorated or disappeared in 39(26.7%)patients,and remained unchanged in 103(70.5%)patients after the intervention.In the 35 patients who initially had trivial-to-moderate aortic regurgitation(AR),the degree of AR was ameliorated or disappeared in 25(71.4%)patients,aggravated from trivial to mild AR in 1(2.9%)patient,and remained unchanged in 9(25.7%)patients.In 111 patients without AR,1(0.9%)patient had mild AR and 24(21.6%)patients had trivial AR after intervention.The depth and width of the prolapsed aortic valve decreased after transcatheter closure of VSD in all three groups.During the 70-month(range,54–77)follow-up period,no patients with AVP and AR needed an aortic valve intervention.Conclusions:Transcatheter closure of VSD with AVP is feasible.The morphology and function of the prolapsed aortic valve improved and remained stable for a long period after intervention.
文摘Natural polyamine is an ideal antitumor drug carrier because of the great requirement difference between cancer cells and normal cells. Previous data demonstrated that many cytotoxic drugs conjugated with natural or synthetic polyamines have potent antitumor effects. Up to now, the antitumor mechanism of conjugates of naphthalimides with polyamine remains poorly understood in human colon cancer cells. The aim of this study is to evaluate the effect of MINS (a novel naph-thalimide-polyamine conjugate) and mechanism of MINS in human colon cancer cells. Mitochondrial toxicity, which was generated by ROS from mitochondria electron transport chain, might be a major factor in MINS-inducted apoptosis. Our data also demonstrated that MINS-mediated cell apoptosis depend on p53 status, for MINS induced Caco-2 cells (p53 null) only necrosis but not apoptosis. Furthermore, the apoptotic effect of MINS is stronger than that of Amonafide, the parent drug of MINS. Our data suggested that the MINS-mediated cell apoptosis depend on p53 in human colon cancer cells.
基金This work was supported by the Guangdong Natural Science Foundation(Grant No.S2011040000529).
文摘Arsenic trioxide(ATO)has been identified as an effective treatment for acute promyelocytic leukemia(APL)but is much less effective against solid tumors such as hepatocellular carcinoma(HCC).In the search for ways to enhance its therapeutic efficacy against solid tumors,we have examined its use in combination with a novel derivative ofβ-elemene,N-(β-elemene-13-yl)tryptophan methyl ester(ETME).Here we report the effects of the combination on cell viability,apoptosis,the cell cycle and mitochondria membrane potential(MMP)in HCC SMMC-7721 cells.We found that the two compounds acted synergistically to enhance antiproliferative activity and apoptosis.The combination also decreased the MMP,down-regulated Bcl-2 and pro-proteins of the caspase family,and up-regulated Bax and BID,all of which were reversed by the p53 inhibitor,pifithrin-α.In addition,the combination induced cell cycle arrest at the G2/M phase and reduced tumor volume and weight in an xenograft model of nude mice.Overall,the results suggest that ETME in combination with ATO may be useful in the treatment of HCC patients particularly those unresponsive to ATO alone.
基金supported by the National Key Research and Development Program of China(2020YFA0112402,2017YFA0103401,and 2016YFA0100601)the National Natural Science Foundation of China(81890991,31930054,31871173,82000111,and 81900115)+1 种基金the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(2017ZT07S347)the Key Research and Development Program of Guangdong Province(2019B020234002)。
文摘During embryogenesis,hematopoietic stem progenitor cells(HSPCs)are believed to be derived from hemogenic endothelial cells(HECs).Moreover,arterial feature is proposed to be a prerequisite for HECs to generate HSPCs with lymphoid potential.Although the molecular basis of hematopoietic stem cell-competent HECs has been delicately elucidated within the embryo proper,the functional and molecular characteristics of HECs in the extraembryonic yolk sac(YS)remain largely unresolved.In this study,we initially identified six molecularly different endothelial populations in the midgestational YS through integrated analysis of several single-cell RNA sequencing(scRNA-seq)datasets and validated the arterial vasculature distribution of Gja5+ECs using a Gja5-EGFP reporter mouse model.Further,we explored the hemogenic potential of different EC populations based on their Gja5-EGFP and CD44 expression levels.The hemogenic potential was ubiquitously detected in spatiotemporally different vascular beds on embryonic days(E)8.5–E9.5 and gradually concentrated in CD44-positive ECs from E10.0.Unexpectedly,B-lymphoid potential was detected in the YS ECs as early as E8.5 regardless of their arterial features.Furthermore,the capacity for generating hematopoietic progenitors with in vivo lymphoid potential was found in nonarterial as well as arterial YS ECs on E10.0–E10.5.Importantly,the distinct identities of E10.0–E10.5 HECs between YS and intraembryonic caudal region were revealed by further scRNA-seq analysis.Cumulatively,these findings extend our knowledge regarding the hemogenic potential of ECs from anatomically and molecularly different vascular beds,providing a theoretical basis for better understanding the sources of HSPCs during mammalian development.
基金the National Natural Science Foundation of China (Nos. 21172053 and 21302041)the China Postdoctoral Science Foundation (No. 2012M521391)+1 种基金the Postdoctoral Science Foundation of Henan Province (No. 2011015)the Foundation of Henan Educational Committee (No. 14A350008)
文摘A series of genistein-polyamine conjugates(4a–4h) were designed, synthesized and evaluated as multi-functional anti-Alzheimer agents. The results showed that these compounds had significant cholinesterases(Ch Es) inhibitory activity. Compound 4b exhibited the strongest inhibition to acetylcholinesterase(ACh E) with an IC_(50) value of 2.75 μmol/L, which was better than that of rivastigmine(5.60 μmol/L). Lineweaver–Burk plot and molecular modeling study showed that compound 4b targeted both the catalytic active site(CAS) and the peripheral anionic site(PAS) of ACh E. Besides, compound 4b showed potent metal-chelating ability. In addition, it was found that 4a–4h did not affect Hep G-2 cell viability at the concentration of 10 μmol/L.
文摘A series of novel 1,2,3-triazole-quinazoline derivatives were synthesized in five steps starting from anthranila- mide by conventional methods. All the title compounds 10a-10r were evaluated for cytotoxic activity against four human cancer cell lines (MGC-803, EC-109, MCF-7 and HGC-27) using MTT assay in vitro. Some of the synthe- sized compounds exhibited moderate to potent activity against tested cancer cell lines. Among them, compounds 10h and 10q exhibited excellent growth inhibition against HGC-27 and compound 10m also possessed excellent ac- tivity against MCF-7, with IC50 values less than 1 μmol/L. Especially, compound 10h was more cytotoxic than 5-fluorouracil against all tested four human cancer cell lines.
基金The work was supported by the National Key R&D Program of China(No.2018YFB1500200)National Natural Science Foundation of China(Nos.61774089 and 61974076)Natural Science Foundation of Tianjin(No.18JCZDJC31200)。
文摘Chalcopyrite Cu(In,Ga)Se_(2)(CIGS) thin films deposited in a low-temperature process(450℃) usually produce fine grains and poor crystallinity. Herein, different Ag treatment processes, which can decrease the melting temperature and enlarge band gap of the CIGS films, were employed to enhance the quality of thin films in a low-temperature deposition process. It is demonstrated that both the Ag precursor and Ag surface treatment process can heighten the crystallinity of CIGS films and the device efficiency. The former is more obvious than the latter. Furthermore, the Urbach energy is also reduced with Ag doping. This work aims to provide a feasible Ag-doping process for the high-quality CIGS films in a low-temperature process.
基金the Natural Science Foundation of Guangdong Province,China(grant number 2016A030313792)the Basic and Applied Basic Research Project of Guangzhou University Joint Project(no.202201020605)the National Natural Science Foundation of China(82270279 and 82200296).
文摘Disruption of the mitochondrial quality surveillance(MQS)system contributes to mitochondrial dysfunction in diabetic cardiomyopathy(DCM).In this study,we observed that cardiac expression of phosphoglycerate mutase 5(PGAM5),a mitochondrial Ser/Thr protein phosphatase,is upregulated in mice with streptozotocin-induced DCM.Notably,DCM-related cardiac structural and functional deficits were negated in cardiomyocyte-specific Pgam5 knockout(Pgam5^(CKO))mice.Hyperglycemic stress impaired adenosine triphosphate production,reduced respiratory activity,and prolonged mitochondrial permeability transition pore opening in acutely isolated neonatal cardiomyocytes from control Pgam5^(f/f) mice,and these effects were markedly prevented in cardiomyocytes from Pgam5^(CKO) mice.Likewise,three main MQS-governed processes—namely,mitochondrial fission/fusion cycling,mitophagy,and biogenesis—were disrupted by hyperglycemia in Pgam5^(f/f),but not in Pgam5^(CKO),cardiomyocytes.On the basis of bioinformatics prediction of interaction between PGAM5 and prohibitin 2(PHB2),an inner mitochondrial membrane-associated scaffolding protein,co-immunoprecipitation,and immunoblot assays demonstrated that PGAM5 dephosphorylates PHB2 on Ser91.Transfection of cardiomyocytes with phosphodefective or phosphomimetic Ser91 mutants of PHB2 confirmed a critical role for PGAM5-mediated dephosphorylation of PHB2 in mitochondrial dysfunction associated with hyperglycemic stress.Furthermore,knockin mice expressing phosphomimetic PHB2^(S91D) were resistant to diabetes-induced cardiac dysfunction.Our findings highlight the PGAM-PHB2 axis as a novel and critical regulator of mitochondrial dysfunction in DCM.