检索结果-南通市图书馆

“Capture-activation-recapture” mechanism-guided design of double-atom catalysts for electrocatalytic nitrogen reduction

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第9期96卷 437-447页

作者： Cheng He Shiqi yan Wenxue Zhang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina School of Materials Science and Engineering Chang’an UniversityXi’an 710064ShaanxiChina

Compared with the traditional industrial nitrogen fixation, electrocatalytic methods, especially those utilizing double-atom catalysts containing nonmetals, can give good consideration to the economy and environmental protection. However, the existing “acceptance-donation” mechanism is only applicable to bimetallic catalysts and nonmetallic double-atom catalysts containing boron atoms. Herein, a novel “capture-activation-recapture” mechanism for metal-nonmetal double-atom catalyst is proposed to solve the problem by adjusting the coordination environments of nonmetallic atoms and utilizing the activation effect of metal atoms on nitrogen. Based on this mechanism, the nitrogen reduction reaction (NRR) activity of 48 structures is calculated by density functional theory calculation, and four candidates are selected as outstanding electrocatalytic nitrogen reduction catalysts: si-Fe@NG (U_(L) = –0.14 V), si-Co@NG (U_(L)= –0.15 V), si-Mo@BP1 (U_(L) = 0 V), and si-Re@BP1 (U_(L) = –0.02 V). The analyses of electronic properties further confirm “capture-activation-recapture” mechanism and suggest that the difference in valence electron distribution between metal and si atoms triggers the activation of N≡N bonds. In addition, a machine learning approach is utilized to generate an expression and an intrinsic descriptor that considers the coordination environment to predict the limiting potential. This study offers profound insight into the synergistic mechanism of TM and si for NRR and guidance in the design of novel double-atom nitrogen fixation catalysts.

关键词： "Capture-activation-recapture"mechanism Double-atom catalyst Nitrogen reduction reaction Density functional theory

Histological,transcriptomic,and gene functional analyses reveal the regulatory events underlying gibberellin-induced parthenocarpy in tomato

在线全文

学校读者我要写书评

暂无评论

Horticultural Plant Journal 2024年第1期10卷 156-170页

作者： Shaobo Niu Yu He siwei yan Zhengliang Sun Run Cai yan Zhang Shaanxi Engineering Research Center for Vegetables College of HorticultureNorthwest A&F UniversityYanglingShaanxi 712100China

Gibberellin(GA)is one of the major plant hormones that promote parthenocarpy,a highly valuable agronomic ***,we demonstrated that exogenous GA3application triggered the formation of parthenocarpic fruits with smaller size but unchanged shape in tomato(Solanum lycopersicum).These fruits exhibited a thicker pericarp,undeveloped ovules,and few jelly tissues,leading to smaller locules with empty *** investigation showed that GA treatment produced more cell layers with larger cells in the pericarp,suggesting its promotion in both cell division and *** analyses between GA-3and mock-treated unpollinated ovaries/fruits identified a large number of differentially expressed genes related to hormones,cell division,cell expansion,and transcription factors,implying that they coordinately regulated parthenocarpy conferred by *** particular,the downregulation of five reported repressors of tomato parthenocarpy,including two auxin signaling components,AUXIN RESPONSE FACTOR5(SlARF5)and Sl ARF7,and three MADS-box genes,TOMATO APETALA3(TAP3),TOMATO PISTILLATA(TPI),and AGAMOUS-LIKE6(SlAGL6),after GA treatment might play a key role in this ***,we found that the knockdown of a GA signaling factor SlMYB33,which was depressed by GA treatment,induced parthenocarpic fruit set in tomato,an effect that might have been achieved by enhancing GA biosynthesis and decreasing the expression of some repressors of tomato ***,our results provide a basis for understanding the regulatory mechanism of GA in tomato parthenocarpy.

关键词： Tomato Gibberellin Parthenocarpy Histology Transcriptome SlMYB33

Chinese Medicine Combined with Adjuvant Chemotherapy for Improving Myelosuppression in Colorectal Cancer Patients:A Systematic Review and Network Meta-Analysis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2024年第7期30卷 643-652页

作者： LI Rui ZHANG Tong yan Shao-hua yan Yun-zi DING Ya-cong WANG yan-song yanG Yu-fei Department of Oncology China Academy of Chinese Medical SciencesXiyuan HospitalBeijing100091China Department of Oncology Dongfang Hospital Beijing University of Chinese MedicineBeijing100078China Graduate School Beijing University of Chinese MedicineBeijing100029China

Objective To assess the effectiveness of Chinese herbal medicine(CHM)combined with adjuvant chemotherapy on myelosuppression for colorectal cancer(CRC)patients using network meta-analysis(NMA).Methods Literature searches in both international(PubMed,Embase,Web of Science,and Cochrane Library)and Chinese(China Science and Technology Journal Database,Wanfang Data,China National Knowledge Infrastructure)databases for relevant randomized controlled trials(RCTs)were conducted from inception until October 10,*** included RCTs of patients who received CHM combined with chemotherapy,including FOLFOX,XELOX,FOLFIRI,and other relevant regimens in the CHM treatment *** outcomes included the incidence of myelosuppression,leukopenia,hemoglobin reduction,and *** reviewers independently screened the databases,extracted the data,and assessed the risk of bias and credibility of *** 5.4.1 software and STATA 14.0 were used to perform the *** A total of 31 RCTs were included,published from 2008 to 2021 in *** these,2,314 participants comparing the following 9 CHMs were identified:Shengbai Recipe(SBR),Bazhen Decoction(BZD),Jianpi Jiedu Recipe(JJR),Jianpi Recipe(JR),Compound Cantharis Capsule(CCC),Zaofan Pill(ZFP),Guilu Erxian Gel(GL),Buzhong Tiaogan Decoction(BZ),and Qiamagu Capsule(QM).The results of NMA found an indirect *** on the surface under the cumulative ranking curve(SUCRA),the ZFP+chemotherapy group had the lowest incidence of myelosuppression,with an odds ratio(OR)of 0.08[95%confidence interval(CI):0.01,0.76],whereas the GL+chemotherapy group had the lowest incidence of leukopenia,hemoglobin reduction,and thrombocytopenia,with an OR of 5.25(95%CI:2.41,11.43),4.66(95%CI:2.23,9.72),and 0.27(95%CI:0.13,0.54),***,BZD+chemotherapy could alleviate leukopenia,hemoglobin reduction,and thrombocytopenia(P<0.01).Pairwise comparison showed that there was no difference in the efficacy among the 8 CHMs+c

关键词： Chinese herbal medicine colorectal cancer network meta-analysis systematic review myelosuppression chemotherapy

Synthetic host-guest pairs as novel bioorthogonal tools for pre-targeting

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第2期35卷 44-56页

作者： yan-Long Ma Shi yan Xiong-Jie Xu Hua Cao Ruibing Wang School of Chemistry and Chemical Engineering and Guangdong Cosmetics Engineering & Technology Research Center Guangdong Pharmaceutical UniversityZhongshan 528458China State Key Laboratory of Quality Research in Chinese Medicine and the Institute of Chinese Medical ScienceUniversity of MacaoMacao 999078China

Due to its simplicity, high efficiency, and chemo-selectivity, bioorthogonal chemistry has shown a great application potential in ***, four bioorthogonal pairs as targeting tools, including (strept)avidin/biotin, antibody/antigen, oligonucleotide hybridization and IEDDA tools, have been developed and applied in targeted ***, all of these tools still suffer from some limitations, such as difficult modification, biochemical fragility and larger molecular weight for biological association tools, as well as chemical instability for IEDDA *** host-guest pairs with relatively small molecular sizes not only possess strong chemical stability, but also have the features of fast conjugation rate, tunable binding affinity , easy modification, and high ***, they can be used as a novel non-covalent bioorthogonal tool for *** order to further promote the development of host-guest pairs as novel bioorthogonal tools for pre-targeted delivery, we firstly calculate their conversion rate to make researcher aware of their unique advantages;next, we summarize the recent research progress in this *** future perspectives and limitations of these unique tools will be *** review will provide a systemic overview of the development of synthetic host-guest pairs as novel bioorthogonal tools for pre-targeting, and may serve as a “go for” resort for researchers who are interested in searching for new synthetic tools to improve pre-targeting.

关键词： Bioorthogonal chemistry Synthetic host-guest pairs Pre-targeting Molecular recognition Biomedical applications

Effects of different concentrations of nicotinamide on hematopoietic stem cells cultured in vitro

在线全文

学校读者我要写书评

暂无评论

World Journal of Stem Cells 2024年第2期16卷 163-175页

作者： yan Ren yan-Ni Cui Hong-Wei Wang The Second Clinical Medical College Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Hematology The Second Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Hematology Key Laboratory of Molecular Diagnosis and Treatment of Blood Diseases in Shanxi ProvinceTaiyuan 030001Shanxi ProvinceChina

BACKGROUND In vitro expansion to increase numbers of hematopoietic stem cells(HSCs)in cord blood could improve clinical efficacy of this vital ***(NAM)can promote HSC expansion ex vivo,but its effect on hematopoietic stem and progenitor cells(HSPCs,CD34^(+)CD38)and functional subtypes of HSCs-shortterm repopulating HSCs(ST-HSCs,CD34^(+)CD38CD45RACD49f^(+))and long-term repopulating HSCs(LT-HSCs,CD34^(+)CD38CD45RACD49f^(+)CD90^(+))is not yet *** a sirtuin 1(siRT1)inhibitor,NAM participates in regulating cell adhesion,polarity,migration,proliferation,and ***,siRT1 exhibits dual effects by promoting or inhibiting differentiation in different tissues or *** propose that the concentration of NAM may influence proliferation,differentiation,and siRT1 signaling of *** To evaluate the effects and underlying mechanisms of action of different concentrations of NAM on HSC proliferation and *** CD34^(+)cells were purified from umbilical cord blood using MacsCD34 beads,and cultured for 10-12 d in a serum-free medium supplemented with cytokines,with different concentrations of NAM added according to experimental *** cytometry was used to detect phenotype,cell cycle distribution,and apoptosis of the cultured ***-time polymerase chain reaction was used to detect the transcription levels of target genes encoding stemness-related factors,che mokines,components of hypoxia pathways,and antioxidant ***-dihydro-fluorescein diacetate probes were used to evaluate intracellular production of reactive oxygen species(ROS).Determination of the effect of different culture conditions on the balance of cytokine by cytometric bead *** Compared with the control group,the proportion and expansion folds of HSPCs(CD34^(+)CD38)incubated with 5 mmol/L or 10 mmol/L NAM were significantly increased(all Psion of the 5 mmol/L NAM group were significantly

关键词： Hematopoietic stem cells Nicotinamide Concentration Proliferation Differentiation sirtuin 1

Sea level rise along China coast from 1950 to 2020

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第3期67卷 802-810页

作者： Dapeng MU Tianhe XU Haoming yan Institute of Space Sciences Shandong UniversityWeihai 264209China Innovation Academy for Precision Measurement Science and Technology Chinese Academy of SciencesWuhan 430071China Institute of Marine and Antarctic Science University of TasmaniaHobartTasmania 7004Australia

Global mean sea level rise has been reconstructed using tide gauges. However, long-term sea level rise along the China coast is unclear. To address this issue, a data assimilation approach is developed to reconstruct sea level rise along the China coast from 1950 to 2020 using a global distribution of tide gauges(TGs). This approach combines climate models and sea level fingerprints. The climate models provide stereodynamic sea level changes. The sea level fingerprints include increases in ocean mass due to global ice melting and changes in water storage on land. The reconstructed global mean sea level rise agrees well with previous studies. We quantify sea level rise at 20 TGs along the China coast. The results suggest that sea level rise along the China coast(1.95±0.33 mm yr^(-1)) is greater than the global mean(1.71±0.17 mm yr^(-1)). We also find that China's coastal sea level rise is more than three times faster after 1980, increasing from 0.84±0.28 mm yr^(-1)for 1950–1980 to3.12±0.21 mm yr^(-1)for 1980–2020. This finding implies a significant sea level acceleration along the China coast. Our results advance the understanding of long-term sea level changes along the China coast.

关键词： Sea level rise China coast Tide gauges Data assimilation

Distributed Minimum-Energy Containment Control of Continuous-Time Multi-Agent Systems by Inverse Optimal Control

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica sinica 2024年第6期11卷 1533-1535页

作者： Fei yan Xiangbiao Liu Tao Feng School of Information Science and Technology Southwest Jiaotong UniversityChengdu 611756China National Engineering Laboratory of Integrated Transportation Big Data Application Technology Chengdu 611756China

Dear Editor,This letter focuses on the distributed optimal containment control of continuous-time multi-agent systems(CTMASs)with respect to the minimum-energy performance index over fixed *** achieve this,we firstly investigate the optimal containment control problem using the inverse optimal control method,where all states of followers asymptotically converge to the convex hull spanned by the leaders while some quadratic performance indexes get minimized.A sufficient condition for existence of the distributed optimal containment control protocol is *** introducing the parametric algebraic Riccati equation(PARE),it is strictly proved that the global performance index can be used to approximate the standard minimumenergy performance index as the parameters tends to *** consequence,the standard minimum-energy cooperative containment control can be solved by local steady state feedback protocols.

关键词： optimal infinity algebraic

Cooperative control for heterogeneous multi-agent systems: progress, applications, and challenges

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第5期67卷 318-320页

作者： Bing yan Peng SHI Jonathon CHAMBERS School of Electrical and Mechanical Engineering Faculty of Science Engineering and TechnologyThe University of Adelaide School of Engineering College of Science and Engineering University of Leicester

Cooperative control for heterogeneous multi-agent systems(MASs) is a critical and rapidly evolving field in modern automation and robotics. Characterized by the integration of agents with diverse capabilities and func... 详细信息

关键词： Multi agent systems

Corrosion behavior of Gd_(2)Zr_(2)O_(7)thermal barrier coatings under Fe-containing environmental sediment attack

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2024年第4期13卷 447-462页

作者： Lei Guo yanyan Li Kai yan School of Materials Science and Engineering Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Advanced Joining Technology Key Lab of Advanced Ceramics and Machining Technology of Ministry of EducationTianjin 300072China Key Laboratory of Special Equipment Safety and Energy-saving for State Market Regulation China Special Equipment Inspection&Research InstituteBeijing 100029China

Environmental sediments mainly consisting of CaO–MgO–Al_(2)O_(3)–siO_(2)(CMAS)corrosion are a serious threat to thermal barrier coatings(TBCs),in which Fe element is usually ***_(2)Zr_(2)O_(7)TBCs are famous for their excellent CMAS *** this study,the characteristics of Fe-containing environmental sediments(CMAS-Fe)and their corrosiveness to Gd_(2)Zr_(2)O_(7)coatings were *** types of CMAS-Fe glass with different Fe contents were *** melting points were measured to be 1322–1344℃,and the high-temperature viscosity showed a decreasing trend with increasing Fe *** corrosion behavior of four types of CMAS-Fe to Gd_(2)Zr_(2)O_(7)coatings at 1350℃was *** the initial corrosion stage(0.1 h),anorthite was precipitated in CMAS-Fe with a high Ca:si ratio,while Fe-garnet was formed in the melt with the highest Fe *** the corrosion time resulted in the formation of a reaction layer,which exhibited an interpenetrating network composed of Gd-oxyapatite,ZrO_(2),and residual *** spinel was precipitated within the reaction *** 1 h or even longer time,the reaction layers tended to be stable and compact,which had comparable hardness and fracture toughness to those of Gd_(2)Zr_(2)O_(7)*** the cyclic CMAS-Fe attack,the residual CMAS-Fe in the interpenetrating network provided a pathway for the redeposited CMAS-Fe infiltration,resulting in the continuous growth of the reaction *** a result,the Gd_(2)Zr_(2)O_(7)coatings had a large consumption in the thickness,degrading the coating ***,the Gd_(2)Zr_(2)O_(7)coatings exhibit unsatisfactory corrosion resistance to CMAS-Fe attack.

关键词： thermal barrier coatings(TBCs) Gd_(2)Zr_(2)O_(7) Fe-containing CaO-MgO-Al2O3-siO_(2)(CMAS) corrosion resistance reaction layer