Light alkanes non-oxidative dehydrogenation is an attractive non-oil route for olefins production.The alkane dehydrogenation reaction is limited by thermodynamic equilibrium,and the C-H bond cleavage is commonly consi...Light alkanes non-oxidative dehydrogenation is an attractive non-oil route for olefins production.The alkane dehydrogenation reaction is limited by thermodynamic equilibrium,and the C-H bond cleavage is commonly considered as the rate-determined step.The valence state of metal sites in catalysts will influence the stabilization of the vital intermediate(i.e.,C_(x)H_(y)...M^(δ+)...H)during the C-H bond cleavage process,which in turn affects the catalytic reactivity.Herein,we explicitly investigated the effect of different valence states of framework-Fe in silicate-1 zeolite on ethane dehydrogenation reaction through the combination of experimental and theoretical study.Fe(Ⅱ)-S-1 and Fe(Ⅲ)-S-1 catalysts are successfully synthesized by ligand-assisted in situ crystallization method,In-situ C_(2)H_6-FTIR shows the higher coverage of hydrocarbon intermediates on Fe(Ⅱ)-S-1,Under the same evaluation co nditio n,Fe(Ⅱ)-S-1 exhibits a higher space time yield of ethylene.Density functional theory(DFT)results reveal that the more coordinate-unsaturated and electron-enriched Fe(Ⅱ)sites boost the first C-H bond activation by slight deformation and efficient electron donation with C_(2)H_(5)^(*)species.Remarkably,the second C-H bond cleavage on Fe(Ⅱ)-S-1 undergoes a spin-crossing process from quintet state to triplet state,which involves a two-electro n-two-orbital interaction,further promoting the formation of ethylene.Microkinetic analysis is consistent with the experimental and DFT results.This work could provide methodology for elucidating the effect of metal valence states on catalytic performance as well as offer guidance for designing more efficient Fe-zeolite catalysts.展开更多
In low-density steel,κ-carbides primarily precipitate in the form of nanoscale particles within austenite grains.However,their precipitation within ferrite matrix grains has not been comprehensively explored,and the ...In low-density steel,κ-carbides primarily precipitate in the form of nanoscale particles within austenite grains.However,their precipitation within ferrite matrix grains has not been comprehensively explored,and the second-phase evolution mechanism during aging remains unclear.In this study,the crystallographic characteristics and morphological evolution ofκ-carbides in Fe-28Mn-10Al-0.8C(wt%)low-density steel at different aging temperatures and times and the impacts of these changes on the steels’microhardness and properties were comprehensively analyzed.Under different heat treatment conditions,intragranularκ-carbides exhibited various morpho-logical and crystallographic characteristics,such as acicular,spherical,and short rod-like shapes.At the initial stage of aging,acicularκ-carbides primarily precipitated,accompanied by a few spherical carbides.κ-Carbides grew and coarsened with aging time,the spherical carbides were considerably reduced,and rod-like carbides coarsened.Vickers hardness testing demonstrated that the material’s hardness was affected by the volume fraction,morphology,and size ofκ-carbides.Extended aging at higher temperatures led to an increase in carbide size and volume fraction,resulting in a gradual rise in hardness.During deformation,the primary mechanisms for strengthening were dislocation strengthening and second-phase strengthening.Based on these findings,potential strategies for improving material strength are proposed.展开更多
Rechargeable magnesium metal batteries need an electrolyte that forms a stable and ionically conductive solid electrolyte interphase(SEI)on the anodes.Here,we used molecular dynamic simulation,density functional theor...Rechargeable magnesium metal batteries need an electrolyte that forms a stable and ionically conductive solid electrolyte interphase(SEI)on the anodes.Here,we used molecular dynamic simulation,density functional theory calculation,and X-ray photoelectron spectroscopy analysis to investigate the solvation structures and SEI compositions in electrolytes consisting of dual-salts,magnesium bis(trifluoromethanesulfonyl)imide(MgTFSI_(2)),and MgCl_(2),with different additives in 1,2-dimethoxyethane(DME)solvent.We found that the formed[Mg_(3)(μ-Cl)_(4)(DME)mTFSI_(2)](m=3,5)inner-shell solvation clusters in MgTFSI_(2)-MgCl_(2)/DME electrolyte could easily decompose and form a MgO-and MgF_(2)-rich SEI.Such electron-rich inorganic species in the SEI,especially MgF_(2),turned out to be detrimental for Mg plating/stripping.To reduce the MgF_(2)and MgO contents in SEI,we introduce an electron-deficient tri(2,2,2-trifluoroethyl)borate(TFEB)additive in the electrolyte.Mg//Mg cells using the MgTFSI_(2)-MgCl_(2)/DME-TFEB electrolyte could cycle stably for over 400 h with a small polarization voltage of~150 mV.Even with the presence of 800 ppm H_(2)O,the electrolyte with TFEB additive could still preserve its good electrochemical performance.The optimized electrolyte also enabled stable cycling and high-rate capability for Mg//Mo6S8 and Mg//CuS full cells,showing great potential for future applications.展开更多
On September 5,2022,a strong earthquake with a magnitude of MS6.8 struck Luding County in Sichuan Province,China,triggering thousands of landslides along the Dadu River in the northwest-southeast(NW-SE)direction.We in...On September 5,2022,a strong earthquake with a magnitude of MS6.8 struck Luding County in Sichuan Province,China,triggering thousands of landslides along the Dadu River in the northwest-southeast(NW-SE)direction.We investigated the reactivation characteristics of historical landslides within the epicentral area of the Luding earthquake to identify the initiation mechanism of earthquake-induced landslides.Records of the two newly triggered and historical landslides were analyzed using manual and threshold methods;the spatial distribution of landslides was assessed in relation to topographical and geological factors using remote sensing images.This study sheds light on the spatial distribution patterns of landslides,especially those that occur above historical landslide areas.Our results revealed a similarity in the spatial distribution trends between historical landslides and new ones induced by earthquakes.These landslides tend to be concentrated within a range of 0.2 km from the river and 2 km from the fault.Notably,both rivers and faults predominantly influenced the reactivation of historical landslides.Remarkably,the reactivated landslides are characterized by their small to medium size and are predominantly situated in historical landslide zones.The number of reactivated landslides surpassed that of previously documented historical landslides within the study area.We provide insights into the critical factors responsible for historical landslides during the 2022 Luding earthquake,thereby enhancing our understanding of the potential implications for future co-seismic hazard assessments and mitigation strategies.展开更多
Recently,exploration breakthroughs have been made in the Lower Cretaceous sandstone reservoirs in the Doseo Basin,but the identification of reservoir fluid property is difficult due to variable reservoir lithology,com...Recently,exploration breakthroughs have been made in the Lower Cretaceous sandstone reservoirs in the Doseo Basin,but the identification of reservoir fluid property is difficult due to variable reservoir lithology,complex oil-water contact within and faint responses of the oil zone,which causes the lower accuracy of reservoir fluid property identification with conventional mudlogging and wirelogging techniques.Applying the geochemical logging,fluorescent logging,mud logging and cutting logging technology,in combination with formation test data,this paper distinguishes the crude oil types,analyzes the logging response characteristics of oil zone after water washing,and establishes the interpretation charts and parameter standards for reservoir fluid properties.The crude oil can be divided into two types,namely viscous-heavy and thin-light,based on total hydrocarbon content and component concentration tested by mud logging,features of pyrolysis gas chromatogram and fluorescence spectroscopy.The general characteristics of oil layers experienced water washing include the decrease of total hydrocarbon content and component concentration from mud logging,the decrease of S1 and PS values from geochemical logging,the decrease of hydrocarbon abundance and absence of some light components in pyrolysis gas chromatogram,and the decrease of fluorescence area and intensity from fluorescence logging.According to crude oil types,the cross plots of S1 versus peak-baseline ratio,and the cross plots of rock wettability versus fluorescence area ratio are drawn and used to interpret reservoir fluid property.Meanwhile,the standards of reservoir fluid parameter are established combining with the parameters of PS and the parameters in above charts,and comprehensive multiparameter correlation in both vertical and horizontal ways is also performed to interpret reservoir fluid property.The application in the Doseo Basin achieved great success,improving interpretation ability of fluid property in the reservoir with complex oil-water contact,and also provided technical reference for the efficient exploration and development of similar reservoirs.展开更多
Objective: To investigate the current situation of the demand for geriatric care services of community residents in Beijing and analyze the influencing factors to provide a reference basis for meeting the demand for d...Objective: To investigate the current situation of the demand for geriatric care services of community residents in Beijing and analyze the influencing factors to provide a reference basis for meeting the demand for diversified and professional geriatric care services. Methods: A self-made questionnaire was used to randomly survey 1558 elderly individuals at community health service centers in 8 urban districts where elderly care centers were planned to be built. The influencing factors of the different characteristics of elderly care service needs from three aspects were analyzed using a dichotomous logistic regression model: predisposing, enabling, and, need factors. Results: 69.7% of the elderly required home care services, 22.8% wanted to get care services at elderly care centers, 15.9% wanted to get care services at nursing homes, 12.3% required community care services, and 7.4% didn’t know where to access care services. 68.5% of the elderly required care services for disabilities/semi-disabilities, 58.0% for dementia, 54.7% for common diseases, 34.9% for rehabilitation training, 33.0% for plumbing care, and 7.5% for hospice care. At the same time, there were urban- rural differences in the demand for elderly care services, with suburban elderly having a higher demand for care services than those living in urban areas (P < 0.05). The elderly’s demand for care services was mainly related to age, place of residence, and gender in the causative factors, mode of residence and physical condition among able factors, and mode of care services and care needs among need factors (P < 0.05). Conclusion: The demand for elderly care services was differentiated by factors including place of residence, age, and gender. It is crucial to accurately match the demand for elderly care services, innovate the mode of elderly care services, and improve the service quality to improve the elderly health service system.展开更多
A high-performance all-inorganic magnesium-lithium chloride complex(MLCC)electrolyte is synthesized by a simple room-temperature reaction of LiCl with MgCl_(2) in tetrahydrofuran(THF)solvent.Molecular dynamics simulat...A high-performance all-inorganic magnesium-lithium chloride complex(MLCC)electrolyte is synthesized by a simple room-temperature reaction of LiCl with MgCl_(2) in tetrahydrofuran(THF)solvent.Molecular dynamics simulation,density functional theory calculation,Raman spectroscopy,and nuclear magnetic resonance spectroscopy reveal that the formation of[Mg_(x)Li_(y)Cl_(2x+y)·nTHF]complex solvation structure significantly lowers the coordination number of THF in the first solvation sheath of Mg^(2+),which significantly enhances its de-solvation kinetics.The MLCC electrolyte presents a stable electrochemical window up to 3.1 V(vs Mg/Mg^(2+))and enables reversible cycling of Mg metal deposition/stripping with an outstanding Coulombic efficiency up to 99%at current densities as high as 10 mA cm^(-2).Utilizing the MLCC electrolyte,a Mg/Mo_(6)S_(8) full cell can be cycled for over 10000 cycles with a superior capacity retention of 85 mA h g^(-1) under an ultrahigh rate of 50 C(1 C=128.8 mA g^(-1)).The facile synthesis of highperformance MLCC electrolyte provides a promising solution for future practical magnesium batteries.展开更多
Wandering on the shore of the Sandu Bay,looking at the blue ocean and the green mountains,a question comes to mind:How can we meet humans’energy demand while minimizing its effect on the environment?In other words,ho...Wandering on the shore of the Sandu Bay,looking at the blue ocean and the green mountains,a question comes to mind:How can we meet humans’energy demand while minimizing its effect on the environment?In other words,how can we ensure a carbon-neutral world in the near future?展开更多
Huanglongbing(HLB) is a devastating disease that has led to an acute crisis for growers of citrus, one of the world's most important fruit crops. The phloem-feeding Asian citrus psyllid(ACP), Diaphorina citri, is ...Huanglongbing(HLB) is a devastating disease that has led to an acute crisis for growers of citrus, one of the world's most important fruit crops. The phloem-feeding Asian citrus psyllid(ACP), Diaphorina citri, is the main pest at the new shoot stage and is the only natural vector of HLB pathogenic bacteria. Little is known about how plants perceive and defend themselves from this destructive pest. Here, we characterized changes in the expression of various genes in citrus plants that were continuously infested by D. citri for different durations(12, 24, and 48 h). A total of 5 219 differentially expressed genes(DEGs) and 643 common DEGs were identified across all time points. Several pathways related to defense were activated, such as peroxisome, alpha-linolenic acid metabolism, and phenylpropanoid and terpenoid biosynthesis, and some pathways related to growth and signal transduction were suppressed in response to D. citri infestation. The expression of genes including kinases(CML44, CIPK6, and XTH6), phytohormones(SAMT, LOX6, and NPR3), transcription factors(bHLH162, WRKY70, and WRKY40), and secondary metabolite synthesis-related genes(PAL, 4CL2, UGT74B1 and CYP82G1) was significantly altered in response to D. citri infestation. The findings of this study greatly enhance our understanding of the mechanisms underlying the defense response of citrus plants to D. citri infestation at the molecular level. Functional characterization of the candidate defense-related genes identified in this study will aid the molecular breeding of insect-resistant citrus varieties.展开更多
Background:N6-methyladenosine(m^(6)A)and DNA 5-methylcytosine(5mC)methylation plays crucial roles in diverse biological processes,including skeletal muscle development and growth.Recent studies unveiled a potential li...Background:N6-methyladenosine(m^(6)A)and DNA 5-methylcytosine(5mC)methylation plays crucial roles in diverse biological processes,including skeletal muscle development and growth.Recent studies unveiled a potential link between these two systems,implicating the potential mechanism of coordinated transcriptional and post-transcrip-tional regulation in porcine prenatal myogenesis and postnatal skeletal muscle growth.Methods:Immunofluorescence and co-IP assays were carried out between the 5mC writers and m^(6)A writers to investigate the molecular basis underneath.Large-scale in-house transcriptomic data were compiled for applying weighted correlation network analysis(WGCNA)to identify the co-expression patterns of m^(6)A and 5mC regulators and their potential role in pig myogenesis.Whole-genome bisulfite sequencing(WGBS)and methylated RNA immu-noprecipitation sequencing(MeRIP-seq)were performed on the skeletal muscle samples from Landrace pigs at four postnatal growth stages(days 30,60,120 and 180).Results:Significantly correlated expression between 5mC writers and m^(6)A writers and co-occurrence of 5mC and m^(6)A modification were revealed from public datasets of C2C12 myoblasts.The protein-protein interactions between the DNA methylase and the m^(6)A methylase were observed in mouse myoblast cells.Further,by analyzing tran-scriptome data comprising 81 pig skeletal muscle samples across 27 developmental stages,we identified a 5mC/m^(6)A epigenetic module eigengene and decoded its potential functions in pre-or post-transcriptional regulation in postnatal skeletal muscle development and growth of pigs.Following integrative multi-omics analyses on the WGBS methylome data and MeRIP-seq data for both m^(6)A and gene expression profiles revealed a genome/transcriptome-wide correlated dynamics and co-occurrence of 5mC and m^(6)A modifications as a consequence of 5mC/m^(6)A crosstalk in the postnatal myogenesis progress of pigs.Last,we identified a group of myogenesis-related genes collaboratively regulated by both 5mC and m^(6)A modifications in postnatal skeletal muscle growth in pigs.Conclusions:Our study discloses a potential epigenetic mechanism in skeletal muscle development and provides a novel direction for animal breeding and drug development of related human muscle-related diseases.展开更多
In the present study,the distribution of Ag in the coating formed on Mg-Ag alloy by plasma electrolytic oxidation(PEO)and its ionic release kinetics when exposed to a 0.9 wt.%Na Cl solution at 37℃have been investigat...In the present study,the distribution of Ag in the coating formed on Mg-Ag alloy by plasma electrolytic oxidation(PEO)and its ionic release kinetics when exposed to a 0.9 wt.%Na Cl solution at 37℃have been investigated.Both metallic Ag and Ag oxide particles with~5 to~40 nm in diameters were observed in the PEO coating.Further,an Ag-enriched layer of~20 nm in thickness at the substrate/coating interface was also observed.The PEO coating on the Mg-Ag alloy not only increases its corrosion resistance with the corrosion current density decreasing by up to 3 orders of magnitude from 8.04×10^(-3)to 4.03×10^(-6)A/cm^(2),but also controls the release of Ag+to the level that is sufficient for anti-infective efficacy without causing cytotoxicity to mammal cells.展开更多
目的:探讨晚期胃/食管胃结合部(gastric/gastroesophageal junction,G/GEJ)腺癌适宜的二线治疗方案。方法:回顾性分析2019年1月至2021年3月于河南省肿瘤医院以紫杉醇单药和紫杉醇联合抗血管或程序性细胞死亡受体-1(programmed cell deat...目的:探讨晚期胃/食管胃结合部(gastric/gastroesophageal junction,G/GEJ)腺癌适宜的二线治疗方案。方法:回顾性分析2019年1月至2021年3月于河南省肿瘤医院以紫杉醇单药和紫杉醇联合抗血管或程序性细胞死亡受体-1(programmed cell death protein 1,PD-1)单抗作为二线治疗的晚期G/GEJ腺癌的临床资料。结果:收集101例患者,中位随访时间为10.4个月,中位总生存期(overall survival,OS)为9.5个月。紫杉醇单药治疗组(43例)、紫杉类联合抗血管组(22例)和紫杉类联合免疫组(36例)客观缓解率(overall response rate,ORR)分别为9.3%、27.3%和30.6%,疾病控制率(disease control rate,DCR)分别为60.5%、86.4%和80.6%,中位无进展生存期(progression-free survival,PFS)分别为2.7个月、4.3个月和3.9个月,中位OS分别为7.0个月、12.0个月和11.0个月,差异均具有统计学意义(均P<0.05)。三组不良反应均可控,无新型不良事件发生,联合抗血管组高血压发生率为40.9%(9/22),联合PD-1单抗组免疫相关不良反应发生率为19.4%(7/36),与其他两组相比差异均具有统计学意义(均P<0.05);多因素分析显示美国东部肿瘤协作组(ECOG)评分、腹膜转移是患者OS的独立影响因素(P<0.05)。结论:紫杉类联合抗血管或PD-1单抗治疗可有效延长患者PFS及OS,临床疗效显著且安全性高,是晚期胃癌二线治疗可选择的方案。展开更多
It is recently suggested that air-formed film plays an important role in controlling corrosion resistance of Mg-Li alloys. However, the structure of the air-formed film and its effect on corrosion resistance of Mg-Li ...It is recently suggested that air-formed film plays an important role in controlling corrosion resistance of Mg-Li alloys. However, the structure of the air-formed film and its effect on corrosion resistance of Mg-Li alloys has not been fully understood. Firstly, the air-formed films formed on α and β phases in a dual-phase LZ91 Mg-Li alloy after exposure to laboratory air for up to 48 h have been examined by SEM under the assistance of ultramicrotomy. Then, the effect of the air-formed film on surface potential and, consequently, corrosion/oxidation behavior of the alloy has been investigated. Finally, in order to exclude the influence from α phase, the structure of the air-formed film on β phase and its effect on corrosion/oxidation behavior of Mg-Li alloys have been studied based on a single-phase LA141 Mg-Li alloy. The results show that the air-formed film is thin and negligible on α phase but thick on β phase after prolonged exposure to laboratory air. The thick air-formed film on β phase has a multilayer structure with an inner layer consisting of Mg O/Mg(OH)_(2) and outer layer consisting of Li_(2)CO_(3), which greatly elevates the surface potential of β phase in air. Both LZ91 and LA141 Mg-Li alloys firstly undergo uniform corrosion and then filiform corrosion when immersed in Na Cl solution and the pre-existed air-formed film on β-Li phase can retard the occurrence of filiform corrosion in the alloys.展开更多
The Goodgrant Foundation is a charitable organization that wants to improve education performance of undergraduates attending colleges and universities in the US. So the foundation plans to contribute a total of US 50...The Goodgrant Foundation is a charitable organization that wants to improve education performance of undergraduates attending colleges and universities in the US. So the foundation plans to contribute a total of US 50 million for a suitable team of schools per year under the condition of avoiding repeated other large grant organizations’ investment. The DEA (Data Estimate Analysis) model is developed to determine an optimal investment strategy for the Goodgrant Foundation. In this paper, two questions were solved: how to choose a suitable team of schools and how to allocate the investment. Before the establishment of the model, the EXCEL software is used to preprocess data. Then the DEA model which includes two models in the paper is developed. For the first question, the CCR model is established to rank schools which used efficiency from DEAP 2.1. For the second question, the resource allocation model is established to allocate investment amount by weights of allocation from MATLAB software. Accordingly, the optimal investment strategy is received for the Goodgrant Foundation. Through the analysis above, 23 from 293 schools are selected to invest. Then the schools are ranked and the investment of US 50 million for 23 schools is allocated.展开更多
Staygreen syndrome or Zhengqing in soybean has recently become a major issue for Chinese growers in the Huang-Huai-Hai river basin.Although previous studies revealed that staygreen can be induced when pods/seeds are d...Staygreen syndrome or Zhengqing in soybean has recently become a major issue for Chinese growers in the Huang-Huai-Hai river basin.Although previous studies revealed that staygreen can be induced when pods/seeds are damaged, it is unknown whether virus infection or insect infestation causes staygreen.To determine whether viral infection causes staygreen, a survey of soybean staygreen incidence in the Huang-Huai-Hai river basin was conducted in 2016 and 2017.Diseased samples were collected and analyzed using DAS-ELISA for Soybean mosaic virus, Watermelon mosaic virus, Bean pod mottle virus, Cucumber mosaic virus, and Bean common mosaic virus.The survey showed that the severity of soybean staygreen syndrome was most prevalent in Beijing, Henan, Shaanxi, and some parts of Shandong provinces, with yield losses from 0 to nearly 100%, but only a small fraction of samples were positive for the tested viruses.A field cage experiment and an insecticide treatment field trial were conducted to determine the contribution of the bean bug, Riptortus pedestris, to staygreen incidence.The field cage experiment showed that R.pedestris treatment resulted in shorter plants, more empty pods, increased numbers of abnormal seeds, and decreased yields.The field experiment showed that there were fewer R.pedestris and less soybean staygreen incidence in fields treated with insecticide than in untreated control fields.Together, these results suggest that R.pedestris infestation rather than virus infection induces staygreen syndrome and that growers in this region can mitigate staygreen syndrome via bean bug control.展开更多
Leaves provide substances and signals for pod and seed development in soybean.However,the regulatory feedbacks of pod and seed to leaf development remain unclear.We investigated the effects of pod and seed on leaf sen...Leaves provide substances and signals for pod and seed development in soybean.However,the regulatory feedbacks of pod and seed to leaf development remain unclear.We investigated the effects of pod and seed on leaf senescence by conducting pod removal and seed injury experiments.Pod removal and seed injury delayed leaf senescence and caused the staygreen phenotype of leaves.There were dosage effects of pod number on the extent of staygreen in depodded plants.The concentrations of chlorophyll(SPAD value,an index of relative chlorophyll content),soluble protein,and soluble sugar in the leaves of depodded plants were higher than those of intact plants.During seed development,the content of IAA decreased,while that of ABA increased.This trend was more pronounced in intact than in depodded and seed-injured plants.The GA3/ABA ratio decreased gradually in all treatments.The content of GA3 was relatively stable and was higher in intact than in depodded plants.The expression levels of four senescence-related genes,Gm SARK,Gm SGR1,Gm CYN1,and Gm NAC,declined in depodded or seed-injured treatments and were positively correlated with the number of leaves retained on plants.Gm FT2 a,the major flowering-promoting gene,was expressed at a higher level while E1,a key flowering inhibitory gene,was expressed at a lower level in depodded than in intact plants.We propose that the pod or seed can regulate leaf development.When the seed is aborted owing to disease infection or pest attack,the leaves stay green because of the absence of the seed signals for senescence.展开更多
目的:分析程序性细胞死亡受体-1(programmed cell death protein 1,PD-1)单抗联合曲妥珠单抗标准治疗在一线HER-2阳性晚期胃癌的临床疗效及安全性。方法:选取2019年6月至2021年6月河南省肿瘤医院HER-2阳性晚期胃癌患者110例,根据治疗方...目的:分析程序性细胞死亡受体-1(programmed cell death protein 1,PD-1)单抗联合曲妥珠单抗标准治疗在一线HER-2阳性晚期胃癌的临床疗效及安全性。方法:选取2019年6月至2021年6月河南省肿瘤医院HER-2阳性晚期胃癌患者110例,根据治疗方法分为研究组(48例)和对照组(62例),比较两组患者临床疗效及安全性。结果:中位随访时间14.2个月,研究组和对照组客观缓解率(overall response rate,ORR)分别为41.7%和37.1%,疾病控制率(disease controlrate,DCR)分别为87.5%和80.6%,中位无进展生存期(median progression-free survival,mPFS)分别为9.2个月和6.8个月(HR=0.624,95%CI:0.396~0.981;P=0.046)。两组患者免疫组织化学(immunohistochemistry,IHC)3+的mPFS分别为11.6个月和6.8个月(HR=0.461,95%CI:0.260~0.817;P=0.012),其中研究组IHC3+和IHC2+(in situ hybridization positive,ISH阳性)的mPFS分别为11.6个月和7.8个月(HR=0.486,95%CI:0.215~1.097;P=0.051),研究组中程序性细胞死亡配体1(programmed cell death-ligand 1,PD-L1)阳性和PD-L1阴性的mPFS分别为9.2个月和4.9个月(HR=0.370,95%CI:0.104~1.322;P=0.033)。研究组和对照组所有不良反应事件中,甲状腺功能减退(P=0.034)及中性粒细胞减少(P=0.046)差异具有统计学意义。多因素分析显示,ECOG评分、腹膜转移及治疗方案是PFS独立影响因素(均P<0.05)。结论:免疫联合曲妥珠单抗标准方案治疗HER-2阳性晚期胃癌具有良好临床疗效,可延长患者PFS,IHC3+患者免疫联合治疗效果可能更佳,且安全性可控。展开更多
基金the financial support from the National Natural Science Foundation of China (22035009,22178381)the National Key R&D Program of China (2021YFA1501301,2021YFC2901100)。
文摘Light alkanes non-oxidative dehydrogenation is an attractive non-oil route for olefins production.The alkane dehydrogenation reaction is limited by thermodynamic equilibrium,and the C-H bond cleavage is commonly considered as the rate-determined step.The valence state of metal sites in catalysts will influence the stabilization of the vital intermediate(i.e.,C_(x)H_(y)...M^(δ+)...H)during the C-H bond cleavage process,which in turn affects the catalytic reactivity.Herein,we explicitly investigated the effect of different valence states of framework-Fe in silicate-1 zeolite on ethane dehydrogenation reaction through the combination of experimental and theoretical study.Fe(Ⅱ)-S-1 and Fe(Ⅲ)-S-1 catalysts are successfully synthesized by ligand-assisted in situ crystallization method,In-situ C_(2)H_6-FTIR shows the higher coverage of hydrocarbon intermediates on Fe(Ⅱ)-S-1,Under the same evaluation co nditio n,Fe(Ⅱ)-S-1 exhibits a higher space time yield of ethylene.Density functional theory(DFT)results reveal that the more coordinate-unsaturated and electron-enriched Fe(Ⅱ)sites boost the first C-H bond activation by slight deformation and efficient electron donation with C_(2)H_(5)^(*)species.Remarkably,the second C-H bond cleavage on Fe(Ⅱ)-S-1 undergoes a spin-crossing process from quintet state to triplet state,which involves a two-electro n-two-orbital interaction,further promoting the formation of ethylene.Microkinetic analysis is consistent with the experimental and DFT results.This work could provide methodology for elucidating the effect of metal valence states on catalytic performance as well as offer guidance for designing more efficient Fe-zeolite catalysts.
基金supported by the National Key Research and Development Program of China(No.2023YFB3711702).
文摘In low-density steel,κ-carbides primarily precipitate in the form of nanoscale particles within austenite grains.However,their precipitation within ferrite matrix grains has not been comprehensively explored,and the second-phase evolution mechanism during aging remains unclear.In this study,the crystallographic characteristics and morphological evolution ofκ-carbides in Fe-28Mn-10Al-0.8C(wt%)low-density steel at different aging temperatures and times and the impacts of these changes on the steels’microhardness and properties were comprehensively analyzed.Under different heat treatment conditions,intragranularκ-carbides exhibited various morpho-logical and crystallographic characteristics,such as acicular,spherical,and short rod-like shapes.At the initial stage of aging,acicularκ-carbides primarily precipitated,accompanied by a few spherical carbides.κ-Carbides grew and coarsened with aging time,the spherical carbides were considerably reduced,and rod-like carbides coarsened.Vickers hardness testing demonstrated that the material’s hardness was affected by the volume fraction,morphology,and size ofκ-carbides.Extended aging at higher temperatures led to an increase in carbide size and volume fraction,resulting in a gradual rise in hardness.During deformation,the primary mechanisms for strengthening were dislocation strengthening and second-phase strengthening.Based on these findings,potential strategies for improving material strength are proposed.
基金supported by the National Natural Science Foundation of China(22150710516,U1832218).
文摘Rechargeable magnesium metal batteries need an electrolyte that forms a stable and ionically conductive solid electrolyte interphase(SEI)on the anodes.Here,we used molecular dynamic simulation,density functional theory calculation,and X-ray photoelectron spectroscopy analysis to investigate the solvation structures and SEI compositions in electrolytes consisting of dual-salts,magnesium bis(trifluoromethanesulfonyl)imide(MgTFSI_(2)),and MgCl_(2),with different additives in 1,2-dimethoxyethane(DME)solvent.We found that the formed[Mg_(3)(μ-Cl)_(4)(DME)mTFSI_(2)](m=3,5)inner-shell solvation clusters in MgTFSI_(2)-MgCl_(2)/DME electrolyte could easily decompose and form a MgO-and MgF_(2)-rich SEI.Such electron-rich inorganic species in the SEI,especially MgF_(2),turned out to be detrimental for Mg plating/stripping.To reduce the MgF_(2)and MgO contents in SEI,we introduce an electron-deficient tri(2,2,2-trifluoroethyl)borate(TFEB)additive in the electrolyte.Mg//Mg cells using the MgTFSI_(2)-MgCl_(2)/DME-TFEB electrolyte could cycle stably for over 400 h with a small polarization voltage of~150 mV.Even with the presence of 800 ppm H_(2)O,the electrolyte with TFEB additive could still preserve its good electrochemical performance.The optimized electrolyte also enabled stable cycling and high-rate capability for Mg//Mo6S8 and Mg//CuS full cells,showing great potential for future applications.
基金financially supported by the National Key R&D Program of China (No. 2022YFF0800604)the National Natural Science Foundation of China (No. 42207224)the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Independent Research Project (SKLGP2022Z021)
文摘On September 5,2022,a strong earthquake with a magnitude of MS6.8 struck Luding County in Sichuan Province,China,triggering thousands of landslides along the Dadu River in the northwest-southeast(NW-SE)direction.We investigated the reactivation characteristics of historical landslides within the epicentral area of the Luding earthquake to identify the initiation mechanism of earthquake-induced landslides.Records of the two newly triggered and historical landslides were analyzed using manual and threshold methods;the spatial distribution of landslides was assessed in relation to topographical and geological factors using remote sensing images.This study sheds light on the spatial distribution patterns of landslides,especially those that occur above historical landslide areas.Our results revealed a similarity in the spatial distribution trends between historical landslides and new ones induced by earthquakes.These landslides tend to be concentrated within a range of 0.2 km from the river and 2 km from the fault.Notably,both rivers and faults predominantly influenced the reactivation of historical landslides.Remarkably,the reactivated landslides are characterized by their small to medium size and are predominantly situated in historical landslide zones.The number of reactivated landslides surpassed that of previously documented historical landslides within the study area.We provide insights into the critical factors responsible for historical landslides during the 2022 Luding earthquake,thereby enhancing our understanding of the potential implications for future co-seismic hazard assessments and mitigation strategies.
基金funded by a project entitled exploration field evaluation and target optimization of key basins in Chad and Niger(No.2019D-4308)initiated by the scientific research and technology development project of china national petroleum corporation.
文摘Recently,exploration breakthroughs have been made in the Lower Cretaceous sandstone reservoirs in the Doseo Basin,but the identification of reservoir fluid property is difficult due to variable reservoir lithology,complex oil-water contact within and faint responses of the oil zone,which causes the lower accuracy of reservoir fluid property identification with conventional mudlogging and wirelogging techniques.Applying the geochemical logging,fluorescent logging,mud logging and cutting logging technology,in combination with formation test data,this paper distinguishes the crude oil types,analyzes the logging response characteristics of oil zone after water washing,and establishes the interpretation charts and parameter standards for reservoir fluid properties.The crude oil can be divided into two types,namely viscous-heavy and thin-light,based on total hydrocarbon content and component concentration tested by mud logging,features of pyrolysis gas chromatogram and fluorescence spectroscopy.The general characteristics of oil layers experienced water washing include the decrease of total hydrocarbon content and component concentration from mud logging,the decrease of S1 and PS values from geochemical logging,the decrease of hydrocarbon abundance and absence of some light components in pyrolysis gas chromatogram,and the decrease of fluorescence area and intensity from fluorescence logging.According to crude oil types,the cross plots of S1 versus peak-baseline ratio,and the cross plots of rock wettability versus fluorescence area ratio are drawn and used to interpret reservoir fluid property.Meanwhile,the standards of reservoir fluid parameter are established combining with the parameters of PS and the parameters in above charts,and comprehensive multiparameter correlation in both vertical and horizontal ways is also performed to interpret reservoir fluid property.The application in the Doseo Basin achieved great success,improving interpretation ability of fluid property in the reservoir with complex oil-water contact,and also provided technical reference for the efficient exploration and development of similar reservoirs.
文摘Objective: To investigate the current situation of the demand for geriatric care services of community residents in Beijing and analyze the influencing factors to provide a reference basis for meeting the demand for diversified and professional geriatric care services. Methods: A self-made questionnaire was used to randomly survey 1558 elderly individuals at community health service centers in 8 urban districts where elderly care centers were planned to be built. The influencing factors of the different characteristics of elderly care service needs from three aspects were analyzed using a dichotomous logistic regression model: predisposing, enabling, and, need factors. Results: 69.7% of the elderly required home care services, 22.8% wanted to get care services at elderly care centers, 15.9% wanted to get care services at nursing homes, 12.3% required community care services, and 7.4% didn’t know where to access care services. 68.5% of the elderly required care services for disabilities/semi-disabilities, 58.0% for dementia, 54.7% for common diseases, 34.9% for rehabilitation training, 33.0% for plumbing care, and 7.5% for hospice care. At the same time, there were urban- rural differences in the demand for elderly care services, with suburban elderly having a higher demand for care services than those living in urban areas (P < 0.05). The elderly’s demand for care services was mainly related to age, place of residence, and gender in the causative factors, mode of residence and physical condition among able factors, and mode of care services and care needs among need factors (P < 0.05). Conclusion: The demand for elderly care services was differentiated by factors including place of residence, age, and gender. It is crucial to accurately match the demand for elderly care services, innovate the mode of elderly care services, and improve the service quality to improve the elderly health service system.
基金supported by the National Natural Science Foundation of China(NSFCU1832218)the Beijing Advanced Innovation Center for Future Chip(ICFC).
文摘A high-performance all-inorganic magnesium-lithium chloride complex(MLCC)electrolyte is synthesized by a simple room-temperature reaction of LiCl with MgCl_(2) in tetrahydrofuran(THF)solvent.Molecular dynamics simulation,density functional theory calculation,Raman spectroscopy,and nuclear magnetic resonance spectroscopy reveal that the formation of[Mg_(x)Li_(y)Cl_(2x+y)·nTHF]complex solvation structure significantly lowers the coordination number of THF in the first solvation sheath of Mg^(2+),which significantly enhances its de-solvation kinetics.The MLCC electrolyte presents a stable electrochemical window up to 3.1 V(vs Mg/Mg^(2+))and enables reversible cycling of Mg metal deposition/stripping with an outstanding Coulombic efficiency up to 99%at current densities as high as 10 mA cm^(-2).Utilizing the MLCC electrolyte,a Mg/Mo_(6)S_(8) full cell can be cycled for over 10000 cycles with a superior capacity retention of 85 mA h g^(-1) under an ultrahigh rate of 50 C(1 C=128.8 mA g^(-1)).The facile synthesis of highperformance MLCC electrolyte provides a promising solution for future practical magnesium batteries.
基金supported by the National Natural Science Foundation of China(12174162 and 51962010)。
文摘Wandering on the shore of the Sandu Bay,looking at the blue ocean and the green mountains,a question comes to mind:How can we meet humans’energy demand while minimizing its effect on the environment?In other words,how can we ensure a carbon-neutral world in the near future?
基金supported by Key Realm R&D Program of Guangdong Province (Grant No. 2020B0202090005)Special Fund for Scientific Innovation Strategy-construction of High Level Academy of Agriculture Science (Grant No. R2020PY-JG002)the President Foundation of Guangdong Academy of Agricultural Sciences (Grant No. 202030)。
文摘Huanglongbing(HLB) is a devastating disease that has led to an acute crisis for growers of citrus, one of the world's most important fruit crops. The phloem-feeding Asian citrus psyllid(ACP), Diaphorina citri, is the main pest at the new shoot stage and is the only natural vector of HLB pathogenic bacteria. Little is known about how plants perceive and defend themselves from this destructive pest. Here, we characterized changes in the expression of various genes in citrus plants that were continuously infested by D. citri for different durations(12, 24, and 48 h). A total of 5 219 differentially expressed genes(DEGs) and 643 common DEGs were identified across all time points. Several pathways related to defense were activated, such as peroxisome, alpha-linolenic acid metabolism, and phenylpropanoid and terpenoid biosynthesis, and some pathways related to growth and signal transduction were suppressed in response to D. citri infestation. The expression of genes including kinases(CML44, CIPK6, and XTH6), phytohormones(SAMT, LOX6, and NPR3), transcription factors(bHLH162, WRKY70, and WRKY40), and secondary metabolite synthesis-related genes(PAL, 4CL2, UGT74B1 and CYP82G1) was significantly altered in response to D. citri infestation. The findings of this study greatly enhance our understanding of the mechanisms underlying the defense response of citrus plants to D. citri infestation at the molecular level. Functional characterization of the candidate defense-related genes identified in this study will aid the molecular breeding of insect-resistant citrus varieties.
基金supported by the Agricultural Science and Technology Innovation Program and The Elite Young Scientists Program of CAAS.ZT was supported by the National Natural Science Foundation of China(31830090)the Basic and Applied Basic Research Foundation of Guangdong province(2019B1515120059)+1 种基金the Shenzhen Dapeng New District Special Fund for Industry Development(KY20180114)the Agricultural Science and Technology Innovation Program(CAAS-ZDRW202006).
文摘Background:N6-methyladenosine(m^(6)A)and DNA 5-methylcytosine(5mC)methylation plays crucial roles in diverse biological processes,including skeletal muscle development and growth.Recent studies unveiled a potential link between these two systems,implicating the potential mechanism of coordinated transcriptional and post-transcrip-tional regulation in porcine prenatal myogenesis and postnatal skeletal muscle growth.Methods:Immunofluorescence and co-IP assays were carried out between the 5mC writers and m^(6)A writers to investigate the molecular basis underneath.Large-scale in-house transcriptomic data were compiled for applying weighted correlation network analysis(WGCNA)to identify the co-expression patterns of m^(6)A and 5mC regulators and their potential role in pig myogenesis.Whole-genome bisulfite sequencing(WGBS)and methylated RNA immu-noprecipitation sequencing(MeRIP-seq)were performed on the skeletal muscle samples from Landrace pigs at four postnatal growth stages(days 30,60,120 and 180).Results:Significantly correlated expression between 5mC writers and m^(6)A writers and co-occurrence of 5mC and m^(6)A modification were revealed from public datasets of C2C12 myoblasts.The protein-protein interactions between the DNA methylase and the m^(6)A methylase were observed in mouse myoblast cells.Further,by analyzing tran-scriptome data comprising 81 pig skeletal muscle samples across 27 developmental stages,we identified a 5mC/m^(6)A epigenetic module eigengene and decoded its potential functions in pre-or post-transcriptional regulation in postnatal skeletal muscle development and growth of pigs.Following integrative multi-omics analyses on the WGBS methylome data and MeRIP-seq data for both m^(6)A and gene expression profiles revealed a genome/transcriptome-wide correlated dynamics and co-occurrence of 5mC and m^(6)A modifications as a consequence of 5mC/m^(6)A crosstalk in the postnatal myogenesis progress of pigs.Last,we identified a group of myogenesis-related genes collaboratively regulated by both 5mC and m^(6)A modifications in postnatal skeletal muscle growth in pigs.Conclusions:Our study discloses a potential epigenetic mechanism in skeletal muscle development and provides a novel direction for animal breeding and drug development of related human muscle-related diseases.
基金the financial support from the Hubei Provincial Natural Science Foundation of China(No.2020CFB295)the National Natural Science Foundation of China(No.52001128)+1 种基金the Innovative Foundation of Huazhong University of Science and Technology(No.2021JYCXJJ023)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(No.B21003)。
文摘In the present study,the distribution of Ag in the coating formed on Mg-Ag alloy by plasma electrolytic oxidation(PEO)and its ionic release kinetics when exposed to a 0.9 wt.%Na Cl solution at 37℃have been investigated.Both metallic Ag and Ag oxide particles with~5 to~40 nm in diameters were observed in the PEO coating.Further,an Ag-enriched layer of~20 nm in thickness at the substrate/coating interface was also observed.The PEO coating on the Mg-Ag alloy not only increases its corrosion resistance with the corrosion current density decreasing by up to 3 orders of magnitude from 8.04×10^(-3)to 4.03×10^(-6)A/cm^(2),but also controls the release of Ag+to the level that is sufficient for anti-infective efficacy without causing cytotoxicity to mammal cells.
文摘目的:探讨晚期胃/食管胃结合部(gastric/gastroesophageal junction,G/GEJ)腺癌适宜的二线治疗方案。方法:回顾性分析2019年1月至2021年3月于河南省肿瘤医院以紫杉醇单药和紫杉醇联合抗血管或程序性细胞死亡受体-1(programmed cell death protein 1,PD-1)单抗作为二线治疗的晚期G/GEJ腺癌的临床资料。结果:收集101例患者,中位随访时间为10.4个月,中位总生存期(overall survival,OS)为9.5个月。紫杉醇单药治疗组(43例)、紫杉类联合抗血管组(22例)和紫杉类联合免疫组(36例)客观缓解率(overall response rate,ORR)分别为9.3%、27.3%和30.6%,疾病控制率(disease control rate,DCR)分别为60.5%、86.4%和80.6%,中位无进展生存期(progression-free survival,PFS)分别为2.7个月、4.3个月和3.9个月,中位OS分别为7.0个月、12.0个月和11.0个月,差异均具有统计学意义(均P<0.05)。三组不良反应均可控,无新型不良事件发生,联合抗血管组高血压发生率为40.9%(9/22),联合PD-1单抗组免疫相关不良反应发生率为19.4%(7/36),与其他两组相比差异均具有统计学意义(均P<0.05);多因素分析显示美国东部肿瘤协作组(ECOG)评分、腹膜转移是患者OS的独立影响因素(P<0.05)。结论:紫杉类联合抗血管或PD-1单抗治疗可有效延长患者PFS及OS,临床疗效显著且安全性高,是晚期胃癌二线治疗可选择的方案。
基金gratefully acknowledge Chongqing Talent Plan: Leading Talents in Innovation and Entrepreneurship (CQYC201903051)University Innovation Research Group of Chongqing (CXQT20023)Natural Science Foundation of Chongqing (cstc2021ycjh-bgzxm0184)。
文摘It is recently suggested that air-formed film plays an important role in controlling corrosion resistance of Mg-Li alloys. However, the structure of the air-formed film and its effect on corrosion resistance of Mg-Li alloys has not been fully understood. Firstly, the air-formed films formed on α and β phases in a dual-phase LZ91 Mg-Li alloy after exposure to laboratory air for up to 48 h have been examined by SEM under the assistance of ultramicrotomy. Then, the effect of the air-formed film on surface potential and, consequently, corrosion/oxidation behavior of the alloy has been investigated. Finally, in order to exclude the influence from α phase, the structure of the air-formed film on β phase and its effect on corrosion/oxidation behavior of Mg-Li alloys have been studied based on a single-phase LA141 Mg-Li alloy. The results show that the air-formed film is thin and negligible on α phase but thick on β phase after prolonged exposure to laboratory air. The thick air-formed film on β phase has a multilayer structure with an inner layer consisting of Mg O/Mg(OH)_(2) and outer layer consisting of Li_(2)CO_(3), which greatly elevates the surface potential of β phase in air. Both LZ91 and LA141 Mg-Li alloys firstly undergo uniform corrosion and then filiform corrosion when immersed in Na Cl solution and the pre-existed air-formed film on β-Li phase can retard the occurrence of filiform corrosion in the alloys.
文摘The Goodgrant Foundation is a charitable organization that wants to improve education performance of undergraduates attending colleges and universities in the US. So the foundation plans to contribute a total of US 50 million for a suitable team of schools per year under the condition of avoiding repeated other large grant organizations’ investment. The DEA (Data Estimate Analysis) model is developed to determine an optimal investment strategy for the Goodgrant Foundation. In this paper, two questions were solved: how to choose a suitable team of schools and how to allocate the investment. Before the establishment of the model, the EXCEL software is used to preprocess data. Then the DEA model which includes two models in the paper is developed. For the first question, the CCR model is established to rank schools which used efficiency from DEAP 2.1. For the second question, the resource allocation model is established to allocate investment amount by weights of allocation from MATLAB software. Accordingly, the optimal investment strategy is received for the Goodgrant Foundation. Through the analysis above, 23 from 293 schools are selected to invest. Then the schools are ranked and the investment of US 50 million for 23 schools is allocated.
基金supported by the National Key Research and Development Program of China (2017YFD0101400) to T.HanChina Agriculture Research System (CARS-04) to T.Han and K.Li
文摘Staygreen syndrome or Zhengqing in soybean has recently become a major issue for Chinese growers in the Huang-Huai-Hai river basin.Although previous studies revealed that staygreen can be induced when pods/seeds are damaged, it is unknown whether virus infection or insect infestation causes staygreen.To determine whether viral infection causes staygreen, a survey of soybean staygreen incidence in the Huang-Huai-Hai river basin was conducted in 2016 and 2017.Diseased samples were collected and analyzed using DAS-ELISA for Soybean mosaic virus, Watermelon mosaic virus, Bean pod mottle virus, Cucumber mosaic virus, and Bean common mosaic virus.The survey showed that the severity of soybean staygreen syndrome was most prevalent in Beijing, Henan, Shaanxi, and some parts of Shandong provinces, with yield losses from 0 to nearly 100%, but only a small fraction of samples were positive for the tested viruses.A field cage experiment and an insecticide treatment field trial were conducted to determine the contribution of the bean bug, Riptortus pedestris, to staygreen incidence.The field cage experiment showed that R.pedestris treatment resulted in shorter plants, more empty pods, increased numbers of abnormal seeds, and decreased yields.The field experiment showed that there were fewer R.pedestris and less soybean staygreen incidence in fields treated with insecticide than in untreated control fields.Together, these results suggest that R.pedestris infestation rather than virus infection induces staygreen syndrome and that growers in this region can mitigate staygreen syndrome via bean bug control.
基金supported by the China Agriculture Research System (No.CARS-04)the Agricultural Science and Technology Innovation Program to T.F.Hanthe National Major Project for Breeding of Transgenic Crops (No.2016ZX08004002) to C.H.Guo
文摘Leaves provide substances and signals for pod and seed development in soybean.However,the regulatory feedbacks of pod and seed to leaf development remain unclear.We investigated the effects of pod and seed on leaf senescence by conducting pod removal and seed injury experiments.Pod removal and seed injury delayed leaf senescence and caused the staygreen phenotype of leaves.There were dosage effects of pod number on the extent of staygreen in depodded plants.The concentrations of chlorophyll(SPAD value,an index of relative chlorophyll content),soluble protein,and soluble sugar in the leaves of depodded plants were higher than those of intact plants.During seed development,the content of IAA decreased,while that of ABA increased.This trend was more pronounced in intact than in depodded and seed-injured plants.The GA3/ABA ratio decreased gradually in all treatments.The content of GA3 was relatively stable and was higher in intact than in depodded plants.The expression levels of four senescence-related genes,Gm SARK,Gm SGR1,Gm CYN1,and Gm NAC,declined in depodded or seed-injured treatments and were positively correlated with the number of leaves retained on plants.Gm FT2 a,the major flowering-promoting gene,was expressed at a higher level while E1,a key flowering inhibitory gene,was expressed at a lower level in depodded than in intact plants.We propose that the pod or seed can regulate leaf development.When the seed is aborted owing to disease infection or pest attack,the leaves stay green because of the absence of the seed signals for senescence.
