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人HcN4通道的滞后现象:影响窦房结起搏的潜在决定因素(英文)

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生理学报 2010年第1期62卷 1-13页

作者：萧永福 Natalie chandler Halina Dobrzynski Eric S.Richardson Erica M.TenBroek Joshua J.Wilhelm Vinod Sharma Anthony Varghese Mark R.Boyett Paul A.Iaizzo daniel c.sigg 美敦力公司心脏节律疾病管理部曼彻斯特大学医学院明尼苏达州大学外科学系明尼苏达州大学整合生物学与生理学系美敦力公司科学技术部威斯康辛大学雷河分校计算机系

超极化活化环核苷酸门控(hyperpolarization-activated cyclic-nucleotide-gated,HcN)通道参与调制心脏跳动的节律和速率。与HcN1和HcN2有所不同,慢通道HcN4可能不存在电压依赖的滞后现象。本研究采用单细胞膜片钳方法,在稳定转染hHcN4... 详细信息

超极化活化环核苷酸门控(hyperpolarization-activated cyclic-nucleotide-gated,HcN)通道参与调制心脏跳动的节律和速率。与HcN1和HcN2有所不同,慢通道HcN4可能不存在电压依赖的滞后现象。本研究采用单细胞膜片钳方法,在稳定转染hHcN4的HEK293细胞上进行电生理记录,观察hHcN4通道是否存在滞后现象,以及cAMP对其的调制作用;同时采用实时定量RT-PcR方法检测窦房结和心房组织中HcNs的表达。电压钳实验结果显示hHcN4电流(Ih)激活随着保持电位超极化的变化而向去极化方向移动。三角电位变化钳(triangular ramp)和动作电位钳的结果也显示了hHcN4的滞后现象。cAMP增加Ih电流幅度,且使电流激活向去极化方向移动,从而改变内源性hHcN4滞后行为。RT-PcR结果显示,人窦房结组织主要表达HcN4,占75%,HcN1占21%,HcN2占3%,HcN3占0.7%。以上结果提示,人窦房结组织主要表达HcN4亚型,hHcN4的Ih存在电压依赖性的滞后现象,且受cAMP调制。由此推断,hHcN4通道的滞后现象可能在窦房结起搏活动中起到了关键作用。

关键词： HcN4通道滞后窦房结 cAMP

Thermal properties and high-temperature ablation of high-entropy (Ti_(0.25)V_(0.25)Zr_(0.25)Hf_(0.25))B_(2) coating on graphite substrate

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Journal of Advanced ceramics 2024年第8期13卷 1268-1281页

作者： Ana c.Feltrin daniel Hedman Farid Akhtar Division of Materials Science Lulea University of TechnologyLulea 97187Sweden center for Multidimensional carbon Materials(cMcM) Institute for Basic Science(IBS)Ulsan 44919Republic of Korea

An entropy-stabilized multicomponent ultrahigh-temperature ceramic(UHTc)coating,(Ti_(0.25)V_(0.25)Zr_(0.25)Hf_(0.25))B_(2),on a graphite substrate was in-situ sintered by spark plasma sintering(SPs)from constituent transition metal diboride ***(Ti_(0.25)V_(0.25)Zr_(0.25)Hf_(0.25))B_(2) coating had a hardness of 31.2±2.1 GPa and resisted 36.9 GPa of stress before delamination,as observed at the *** temperature-dependent thermal properties of the multicomponent diboride(Ti_(0.25)V_(0.25)Zr_(0.25)Hf_(0.25))B_(2) were obtained by molecular dynamics(MD)simulations driven by a machine learning force field(MLFF)trained on density functional theory(DFT)*** thermal conductivity,density,heat capacity,and coefficient of thermal expansion obtained by the MD simulations were used in time-dependent thermal stress finite element model(FEM)*** low thermal conductivity(component diboride coupled with its similar coefficient of thermal expansion to that of graphite indicated that stresses of less than 10 GPa were generated at the interface at high temperatures,and therefore,the coating was mechanically resistant to the thermal stress induced during *** experiments at 220℃ showed that the multicomponent diboride coating was resistant to thermal stresses with no visible cracking or *** ablation mechanisms were mechanical denudation and evaporation of B_(2)O_(5) and light V-Ti oxides,which caused a decrease in the mass and thickness of the coating and resulted in mass and linear ablation rates of-0.51 mg·s^(-1) and -1.38μm·s^(-1),respectively,after 60 *** findings demonstrated the thermal and mechanical stability of multicomponent entropy-stabilized diborides as coatings for carbon materials in engineering components under extreme environments.

关键词： entropy-stabilized diborides ultrahigh temperature ceramics molecular dynamics(MD)simulations density functional theory(DFT) ablation properties

The role of extracorporeal life support and timing of repair in infants with congenital diaphragmatic hernia

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World Journal of Pediatric Surgery 2024年第2期7卷 90-99页

作者： daniel B Gehle Logan c Meyer Tim Jancelewicz Le Bonheur children's Hospital University of Tennessee Health Science CenterMemphisTennesseeUSA

Extracorporeal life support(EcLS)serves as a rescue therapy for patients with congenital diaphragmatic hernia(cDH)and severe cardiopulmonary failure,and only half of these patients survive to *** costly intervention has a significant complication risk and is reserved for patients with the most severe disease physiology refractory to maximal cardiopulmonary *** contraindications to EcLS do exist such as coagulopathy,lethal chromosomal or congenital anomaly,very preterm birth,or very low birth weight,but many of these limits are being evaluated through further *** guidelines from the past decade vary in recommendations for EcLS use in patients with cDH but this therapy appears to have a survival benefit in the most severe subset of *** outcomes have been observed for patients treated at high-volume *** review details the evolving literature surrounding management paradigms for timing of cDH repair for patients receiving preoperative *** recent data support early repair following cannulation to avoid non-repair which is uniformly fatal in this *** EcLS runs are associated with decreased survival,and patient physiology should guide EcLS weaning and eventual decannulation rather than limiting patients to arbitrary run *** of care across centers is a major focus to limit unnecessary costs and improve short-term and long-term outcomes for these complex patients.

关键词： congenital life repair

Mineral-mediated stability of organic carbon in soil and relevant interaction mechanisms

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Eco-Environment & Health 2024年第1期3卷 59-76页

作者： Zibo Xu daniel c.W.Tsang Department of civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Department of civil and Environmental Engineering The Hong Kong University of Science and TechnologyClear Water BayHong KongChina

Soil,the largest terrestrial carbon reservoir,is central to climate change and relevant feedback to environmental *** are the essential components that contribute to over 60%of soil carbon ***,how the interactions between minerals and organic carbon shape the carbon transformation and stability remains poorly ***,we critically review the primary interactions between organic carbon and soil minerals and the relevant mechanisms,including sorption,redox reaction,co-precipitation,dissolution,polymerization,and catalytic *** interactions,highly complex with the combination of multiple processes,greatly affect the stability of organic carbon through the following processes:(1)formation or deconstruction of the mineral–organic carbon association;(2)oxidative transformation of the organic carbon with minerals;(3)catalytic polymerization of organic carbon with minerals;and(4)varying association stability of organic carbon according to the mineral *** pieces of evidence related to the carbon turnover and stability during the interaction with soil minerals in the real eco-environment are then *** also highlight the current research gaps and outline research priorities,which may map future directions for a deeper mechanismsbased understanding of the soil carbon storage capacity considering its interactions with minerals.

关键词： carbon stability Mineral transformation carbon sequestration Bio-geochemistry Soil carbon management Sustainable waste management

Plant-microbial fuel cell for electrical generation through living plants: an internal resistance insight into the plant species used

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clean Energy 2024年第5期8卷 45-53页

作者： Raymond daniel Rodriguez Martinez Department of Industrial Production Faculty of EngineeringUniversidad Metropolitana1073 CaracasVenezuela

climate change is a global threat,the presence of which has encouraged the development and implementation of renewable energies,including plant–microbial fuel cells,which could generate 6629568–33147840 MWh per year due to their large-scale *** of the main challenges associated with microbial cells is internal resistance—a parameter whose magnitude is influenced by sev-eral *** the case of plant–microbial fuel cells,adding a plant positively affects the mitigation of internal ***,the species employed is expected to play an important *** the present study,the objective was to determine as a general reference the internal resistance of cells using various plant species,among which were tomato(Solanum lycopersicum),black beans(Phaseolus vulgaris),aloe vera(Aloe vera),corn(Zea mays),and moss(Dicranidae).For this purpose,an experimental procedure was carried out to compare the manual voltage measurements with a free cell concerning the voltage obtained by adding an external resistor in *** internal resistance values were determined as a function of the measured voltage,obtaining 177,179,175,324,and 233 kΩfor aloe vera,corn,tomato,black beans,and moss,*** this,it was shown that the roots of the plants represent an essen-tial addition to the internal resistance of the cell in the short *** contrast,plants with a c4 photosynthetic metabolism are more favourable,while c3 plants can also benefit from internal resistance during a more extended period of rhizodeposition.

关键词： climate change energy microorganism renewable source voltage

Floristic composition and edaphic relationships in ferruginous campo rupestre reference ecosystems

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Journal of Mountain Science 2024年第3期21卷 719-733页

作者： G.Wilson FERNANDES Letícia RAMOS Dario c.PAIVA Jéssica cUNHA-BLUM Vanessa Matos GOMES daniel NEGREIROS Ecologia Evolutiva&Biodiversidade Departamento de GenéticaEcologia e Evolução/ICBUniversidade Federal de Minas Gerais31270-901Belo HorizonteMGBrazil Knowledge center for Biodiversity 31270-901Belo HorizonteMGBrazil Department of Biological Sciences Institute of EnvironmentFlorida International UniversityMiamiFL 33199USA Programa de Pós Graduação em Biodiversidade e Uso dos Recursos Naturais Universidade Estadual de Montes ClarosMontes ClarosMGBrazil Laboratório de Estudo das Relações Solo-Planta Departamento de SolosUniversidade Federal Rural do Rio de JaneiroSeropédicaRGBrazil

Land use change and occupation have led to modifications in the environment causing loss of biodiversity and ecosystem services throughout the *** environments with high economic relevance,such as the ferruginous campo rupestre(rupestrian grassland known as canga in Brazil),are even more susceptible to severe impacts due to their extreme habitat conditions and low *** determination of reference ecosystems based on the intrinsic characteristics of the ecosystem is essential for conservation as well as to the implementation of ecological *** proposed the reference ecosystem of the three main types of habitats of the ferruginous campo rupestre based on their floristic *** described the floristic composition of each habitat and evaluated the physicochemical properties of the soils and the relationship between plants and *** three habitats showed high diversity of plant species and many endemic species,such as chamaecrista choriophylla,cuphea pseudovaccinium,Lychnophora pinaster,and Vellozia *** distribution of vegetation was strongly related with the edaphic characteristics,with a set of species more adapted to high concentration of base saturation,fine sand,organic carbon,and iron,while another set of species succeeded in more acidic soils with higher S and silt *** provide support for the contention that the ferruginous campo rupestre is a mosaic of different habitats shaped by intrinsic local *** to recognize the floristic composition of each particular habitat can lead to inappropriate restoration,increased habitat homogenization and increased loss of biodiversity and ecosystem *** study also advances the knowledge base for building the reference ecosystem for the different types of ferruginous campo rupestre habitats,as well as a key database for highlighting those species contribute most to community assembly in this diverse and threatened tropical mountain ecosystem.

关键词： canga Ecological restoration Extreme ecosystem Non-forest ecosystems Rupestrian grassland Taxon environment relationships

characterization of Arroyo Verde Epithermal Deposit:Paragenesis,Mineral Geochemistry,Geochronology and Fluid Inclusions in Lower chon Aike Volcanism,Argentina

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Journal of Earth Science 2024年第1期35卷 62-84页

作者： cecilia Pavón Pivetta Leonardo Benedini Paulo Marcos Ma.Agustina cócola Mercedes Virginia Barros daniel Gregori Leonardo Strazzere Anderson costa dos Santos Mauro c.Geraldes Instituto Geologico del Sur(INGEOSUR) Universidad Nacional del Sur(UNS)-Consejo Nacional de Investigaciones Cientificas y Tecnicas(CONICET)Bahia Blanca 8000Argentina Dpto.de Geologia Universidad Nacional del Sur(UNS)Bahia Blanca 8000Argentina Universidad Nacional de Rio Negro Instituto de Investigacion en Paleobiologia y GeologiaGeneral Roca 8332Argentina Universidade do Estado do Rio de Janeiro Faculdade de GeologiaDepartamento de Mineralogia e Petrologia igneaRiodeJaneiro20559-900Brazil Geobiotec Departamento de GeocienciasUniversidade de AveiroAveiro 3800-002Portuga

Arroyo Verde epithermal deposit,in the North Patagonia region of Argentina,is located within the Lower chon Aike volcanism and is developed between 192.6±2.5 Ma(mineralization host rock)and 189.5±2.6 Ma(overlying lava).Marifil volcanic complex is the host rock for these veins,veinlets and *** particular small deposit has developed low to intermediate sulphidation characteristics,with gangue mineral textures associated with several ore *** probe microanalysis determines electrum,silver minerals such as acanthite,and tetrahedrite,related Ag-cu minerals like jalpaite,mckinstryite,stromeyerite,and base metals like chalcopyrite,sphalerite,galena and *** inclusions in quartz of two out of five events indicate that these Low Jurassic veins were formed due to subtle boiling and dilution mechanisms and by low-salinity(3.4 wt.%to 6.7 wt.%Nacl Eq)magmatic-hydrothermal fluid at 225 to 310℃.The fluid inclusion measurements that indicate boiling(Event 3)were plotted,and based on this data,we interpret that the Arroyo Verde deposit has been eroded between 550 and 700 *** particular character has not been previously recorded for other sectors of the eastern north Patagonian region.

关键词： epithermal deposit Ag minerals mineral geochemistry fluid inclusions chon Aike geochronology

comprehensive review of hepatocellular carcinoma with portal vein tumor thrombus:State of art and future perspectives

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Hepatobiliary & Pancreatic Diseases International 2024年第3期23卷 221-227页

作者： Paschalis Gavriilidis Timothy M Pawlik daniel Azoulay Department of Surgery Colchester General HospitalTurner RoadColchester CO45JLUK Department of Surgery The Ohio State Wexner Medical CenterJames Comprehensive Cancer CenterColumbusOHUSA Department of Hepato-Biliary and Liver Transplantation surgery Paul Brousse University HospitalParis-Saclay UniversityVillejuif 94800France

Background:Despite advances in the diagnosis of patients with hepatocellular carcinoma(Hcc),70%-80%of patients are diagnosed with advanced stage *** vein tumor thrombus(PVTT)is among the most ominous signs of advanced stage disease and has been associated with poor survival if *** sources:A systematic search of MEDLINE(PubMed),Embase,cochrane Library and Database for Systematic Reviews(cDSR),Google Scholar,and National Institute for Health and clinical Excellence(NIcE)databases until December 2022 was conducted using free text and MeSH terms:hepatocellular carcinoma,portal vein tumor thrombus,portal vein thrombosis,vascular invasion,liver and/or hepatic resection,liver transplantation,and systematic ***:centers of surgical excellence have reported promising results related to the individualized surgical management of portal thrombus versus arterial chemoembolization or systemic *** elements to the individualized surgical management of Hcc and portal thrombus include precise classification of the portal vein tumor thrombus,accurate identification of the subgroups of patients who may benefit from resection,as well as meticulous surgical *** review addressed five specific areas:(a)formation of PVTT;(b)classifications of PVTT;(c)controversies related to clinical guidelines;(d)surgical treatments versus non-surgical approaches;and(e)characterization of surgical techniques correlated with classifications of ***:current evidence from chinese and Japanese high-volume centers demonstrated that patients with Hcc and associated PVTT can be managed with surgical resection with acceptable results.

关键词： Hepatectomy Liver surgery Liver neoplasms Portal vein tumor thrombus

Flame Synthesis of Zr/ZSM-5 catalysts with Tunable Acidity for the Oxidative Dehydrogenation of Propane to Propene

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Journal of Thermal Science 2024年第1期33卷 268-283页

作者： daniel Samuel FONZEU MONGUEN cedric Karel WU Lingnan TIAN Zhenyu Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of chinese Academy of Sciences Beijing 100049China

Tuning the surface acidity of ZSM-5 catalyst is essential to achieve desired propene selectivity and *** several ratios of Zr were utilized to modify ZSM-5 via flame spray pyrolysis technique coupled with a pulse spray evaporation *** interaction between Zr and ZSM-5 in the flame influenced the physicochemical and acidity properties of the Zr/*** increasing Zr ratio in ZSM-5 shows coated layers of irregular nano-sized Zr with an increase in crystallite sizes due to the synergetic effect between Zr and *** surface chemical analysis revealed increased lattice oxygen on the Zr modified ZSM-5(1:4) sample compared to other *** acidity analysis revealed the Lewis and Br?nsted acid distribution in the weak and medium acid sites on the catalyst ***,the increase in Zr loading decreased the concentration of Br?nsted acid sites and tuned the catalyst surface to more Lewis acidity,promoting propene selectivity and hindering the over-oxidation of *** modified ZSM-5 catalysts were examined in a fixed bed reactor within 300℃-700℃ at a gas hourly space velocity(GHSV) of 6000 mL·g(catalysts)^(-1)·h^(-1) for the oxidative dehydrogenation of propane(ODHP) to *** the catalysts,Zr/ZSM-5(1:4) exhibited the best propene yield, with 57.19% propane conversion and 75.54% selectivity to propene and the highest *** work provides a promising strategy for tuning the surface acidity of ZSM-5 with Zr for ODHP applications.

关键词： flame synthesis Zr modified ZSM-5 catalyst ODHP surface acidity lattice oxygen