检索结果-南通市图书馆

Analysing vaccine efficacy evaluated in phase 3 clinical trials carried out during outbreaks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Infectious Disease Modelling 2024年第4期9卷 1027-1044页

作者： Francisco Antonio Bezerra Coutinho Marcos Amaku Fernanda Castro Boulos Jose Alfredo de Sousa Moreira Joao Italo DiasFranca Julio Antonio do Amaral Eliana Nogueira Castro de Barros Claudio Jose Struchiner Esper Jorge Kallas Eduardo Massad School of Medicine University of Sao PauloBrazil Instituto Butantan Sao PauloBrazil School of Applied Mathematics Fundacao Getulio VargasRio de JaneiroBrazil

In this paper we examine several definitions of vaccine efficacy(VE)that we found in the literature,for diseases that express themselves in outbreaks,that is,when the force of infection grows in time,reaches a maximum and then *** fact that the disease occurs in outbreaks results in several problems that we *** propose a mathematical model that allows the calculation of VE for several *** trials usually needs a large number of volunteers that must be ***,all volunteers should be enrolled in approximately the same time,but this is generally impossible for logistic reasons and they are enrolled in a fashion that can be replaced by a continuous density function(for example,a Gaussian function).The outbreak can also be replaced by a continuous density function,and the use of these density functions simplifies the ***,for example Gaussian functions,one of the problems one can immediately notice is that the peak of the two curves do not occur at the same *** model allows us to conclude:First,the calculated vaccine efficacy decreases when the force of infection increases;Second,the calculated vaccine efficacy decreases when the gap between the peak in the force of infection and the peak in the enrollment rate increases;Third,different trial protocols can be simulated with this model;different vaccine efficacy definitions can be calculated and in our simulations,all result are approximately the *** final,and perhaps most important conclusion of our model,is that vaccine efficacy calculated during outbreaks must be carefully examined and the best way we can suggest to overcome this problem is to stratify the enrolled volunteer's in a cohort-by-cohort basis and do the survival analysis for each cohort,or apply the Cox proportional hazards model for each cohort.

关键词： Vaccine efficacy Clinical trials Mathematical models Simulations Covid-19

A Rapid Parameter of Enzyme-Treated Cellulosic Material Revealed by Reducing Sugar Release

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Renewable Materials 2024年第3期12卷 539-551页

作者： Verônica Távilla Ferreira Silva Adriane Maria Ferreira Milagres Departamento de Biotecnologia Escola de Engenharia de LorenaUniversidade de São PauloLorenaSP12602-810Brazil

This study was conducted to evaluate the effectiveness of enzymes in purifying and reducing the degree of polymerization of cellulose for the production of dissolving *** goal was to determine the contributions of xylanase(X)and endoglucanase(EG)in the treatment of pulp,specifically by quantifying the formation of soluble and insoluble reducing sugars using the dinitrosalycilic acid(DNS)***,the release of soluble reducing sugars(RSSol)was enhanced after xylanase treatment,while endoglucanase(EG)treatment led to changes in insoluble reducing sugars(RSIns).The maximum synergism was observed for RSIns when a high ratio of endoglucanase to xylanase(320EG:5X/g pulp)was *** relative contribution of endoglucanase to RSins was determined to be 15.6%of the total reducing *** viscosity of pulps treated with xylanase decreased only by 7%,whereas endoglucanase treatment significantly reduced viscosity by 45%.Modifications in the particle size were observed after pulp treatment with the combination of endoglucanase and *** summary,the DNS test is a rapid and effective method for evaluating the efficiency of enzyme treatments on *** measurement of RSIns correlates with changes in pulp viscosity to different extents,providing valuable insights into the effectiveness of enzyme treatments.

关键词： Endoglucanase xylanase cellulose fiber pulp synergism

Machine learning algorithm partially reconfigured on FPGA for an image edge detection system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Electronic Science and Technology 2024年第2期22卷 48-68页

作者： Gracieth Cavalcanti Batista Johnny Oberg Osamu Saotome Haroldo F.de Campos Velho Elcio Hideiti Shiguemori Ingemar Soderquist Division of Electronic and Embedded Systems KTH Royal Institute of TechnologyStockholm 16440Sweden Electronic Engineering Division Aeronautics Institute of TechnologySao Josédos Campos SP 12228-900Brazil Laboratory of Applied Computing and Mathematics National Institute for Space ResearchSao Josédos Campos SP 12227-900Brazil Department of C4ISR Institute of Advanced StudiesSao Josédos Campos SP 12228-001Brazil Saab AB Linkoping 58188Sweden

Unmanned aerial vehicles(UAVs)have been widely used in military,medical,wireless communications,aerial surveillance,*** key topic involving UAVs is pose estimation in autonomous navigation.A standard procedure for this process is to combine inertial navigation system sensor information with the global navigation satellite system(GNSS)***,some factors can interfere with the GNSS signal,such as ionospheric scintillation,jamming,or *** alternative method to avoid using the GNSS signal is to apply an image processing approach by matching UAV images with georeferenced *** a high effort is required for image edge *** a support vector regression(SVR)model is proposed to reduce this computational load and processing *** dynamic partial reconfiguration(DPR)of part of the SVR datapath is implemented to accelerate the process,reduce the area,and analyze its granularity by increasing the grain size of the reconfigurable *** show that the implementation in hardware is 68 times faster than that in *** architecture with DPR also facilitates the low power consumption of 4 mW,leading to a reduction of 57%than that without *** is also the lowest power consumption in current machine learning hardware ***,the circuitry area is 41 times *** with Gaussian kernel shows a success rate of 99.18%and minimum square error of 0.0146 for testing with the planning *** system is useful for adaptive applications where the user/designer can modify/reconfigure the hardware layout during its application,thus contributing to lower power consumption,smaller hardware area,and shorter execution time.

关键词： Dynamic partial reconfiguration(DPR) Field programmable gate array(FPGA)implementation Image edge detection Support vector regression(SVR) Unmanned aerial vehicle(UAV) pose estimation

Adsorption of yttrium(Y^(3+)) and concentration of rare earth elements from phosphogypsum using chitin and chitin aerogel

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第4期42卷 775-782页

作者： Glaydson S.dos Reis Diana Pinto Sabrina F.Lütke Eder C.Lima Luis F.O.Silva Irineu A.S.De Brum Guilherme L.Dotto Department of Forest Biomaterials and Technology Biomass Technology Centre Swedish University of Agricultural SciencesUmeaE13Swedn Universidad De La Costa Calle 58#55-66080002BarranquillaAtlanticoColombia Research Group on Adsorptive and Catalytic Process Engineering(ENGEPAC) Federal University of Santa MariaAv.Roraima100079705900Santa MariaRSBrazil Institute of Chemistry Federal University of Rio Grande do Sul90040060Porto AlegreBrazil

Chitin powder and chitin-aerogel were prepared from shrimp wastes and used to uptake Y^(3+)from aqueous solutions and concentrate this rare earth element from phosphogypsum(PG).Chitin aerogel displays a specific surface area of 945 m^(2)/g,while chitin powder is 3.6 m^(2)/g,which largely influences its adsorption *** the adsorption in synthetic solutions,the effect of pH on Y^(3+)removal is strong for chitin powder *** contrast,no big pH influence was detected for chitin *** interactions and chelation can highlight the proposed mechanism of Y^(3+)on chitin adsorbents for the powder and ***,in addition to these interactions,pore filling/pore diffusion is the main mechanism of Y^(3+)removal in the chitin *** aerogel is efficient in concentrating 8 times the Y^(3+)from PG,a very complex *** complex chitin aerogel-Y^(3+)can be a secondary source of rare earth elements for other applications.

关键词： Rare earths Sustainable material Chitin powder Chitin porous aerogel Yttrium adsorption and recovery

Rotating effects on the photoionization cross-section of a 2D quantum ring

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第10期76卷 153-159页

作者： Carlos Magno O Pereira Frankbelson dos S Azevedo Luís Fernando C Pereira Edilberto O Silva Departamento de Física Universidade Federal do Maranh?o

In this article, we investigate the nonrelativistic quantum motion of a charged particle within a rotating frame, taking into account the Aharonov–Bohm(AB) effect and a uniform magnetic field. Our analysis entails the derivation of the equation of motion and the corresponding radial equation to describe the system. Solving the resulting radial equation enables us to determine the eigenvalues and eigenfunctions, providing a clear expression for the energy levels. Furthermore,our numerical analysis highlights the substantial influence of rotation on both energy levels and optical properties. Specifically, we evaluate the photoionization cross-section with and without the effects of rotation. To elucidate the impact of rotation on the photoionization process of the system, we present graphics that offer an appealing visualization of the intrinsic nature of the physics involved.

关键词： Aharonov-Bohm effect photoionization cross-section quantum ring rotating effect

Assembly structures of coastal woody species of eastern South America:Patterns and drivers

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Plant Diversity 2024年第5期46卷 611-620页

作者： Eduardo Vinícius da Silva Oliveira Myrna Friederichs Landim Sidney F.Gouveia Graduate Program in Ecology and Conservation Federal University of SergipeSão CristovãoSergipeBrazil National Institute of Science and Technology Ecology Evolution and Conservation of Biodiversity(INCT-EECBio)GoiâniaGoiasBrazil Department of Biology Federal University of SergipeSão CristóvãoSergipeBrazil Department of Ecology Federal University of SergipeSão CristóvãoSergipeBrazil

Tropical regions have provided new insights into how ecological communities are *** dry coastal communities,water stress has been hypothesized to determine plant assembly structure by favoring preadapted lineages from neighboring ecosystems,consistent with functional ***,it is unclear whether this hypothesis is sufficient to explain how coastal communities in tropical ecosystems are ***,we test whether water stress or other factors drive community assembly in woody plant communities across the coastal zone of Brazil,a tropical *** characterized functional and phylogenetic structures of these communities and determined the underlying environmental factors(e.g.,water stress,historical climate stability,edaphic constraints,and habitat heterogeneity)that drive their community *** of coastal woody species show geographically varied patterns,including stochastic arrangements,clustering,and overdispersion of species relative to their traits and phylogenetic *** complexity,water vapor pressure,and soil nutrient availability best explained the gradient in the functional *** deficit,water vapor pressure,and soil organic carbon were the best predictors of variation in phylogenetic *** results support the water-stress conservatism hypothesis on functional and phylogenetic structure,as well as the effect of habitat heterogeneity on functional structure and edaphic constraints on functional and phylogenetic *** effects are associated with increased phenotypic and phylogenetic divergence of woody plant assemblages,which is likely mediated by abiotic filtering and niche opportunities,suggesting a complex pattern of ecological assembly.

关键词： Brazil Completeness Clustering Restinga vegetation Water constraints

New avenues for the treatment of immunotherapy-resistant pancreatic cancer

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第4期16卷 1134-1153页

作者： Luis Guilherme de Oliveira Silva Fabian Fellipe Bueno Lemos Marcel Silva Luz Samuel Luca Rocha Pinheiro Mariana dos Santos Calmon Gabriel Lima Correa Santos Gabriel Reis Rocha Fabrício Freire de Melo Instituto Multidisciplinar em Saúde Universidade Federal da BahiaVitória da Conquista 45029-094BahiaBrazil

Pancreatic cancer(PC)is characterized by its extremely aggressive nature and ranks 14th in the number of new cancer cases ***,due to its complexity,it ranks 7th in the list of the most lethal cancers *** pathogenesis of PC involves several complex processes,including familial genetic factors associated with risk factors such as obesity,diabetes mellitus,chronic pancreatitis,and *** in genes such as KRAS,TP53,and SMAD4 are linked to the appearance of malignant cells that generate pancreatic lesions and,consequently,*** this context,some therapies are used for PC,one of which is immunotherapy,which is extremely promising in various other types of cancer but has shown little response in the treatment of PC due to various resistance mechanisms that contribute to a drop in immunotherapy *** is therefore clear that the tumor microenvironment(TME)has a huge impact on the resistance process,since cellular and non-cellular elements create an immunosuppressive environment,characterized by a dense desmoplastic stroma with cancerassociated fibroblasts,pancreatic stellate cells,extracellular matrix,and immunosuppressive *** to this are genetic mutations in TP53 and immunosuppressive factors that act on T cells,resulting in a shortage of CD8+T cells and limited expression of activation markers such as *** this way,finding new strategies that make it possible to manipulate resistance mechanisms is ***,techniques such as the use of TME modulators that block receptors and stromal molecules that generate resistance,the use of genetic manipulation in specific regions,such as microRNAs,the modulation of extrinsic and intrinsic factors associated with T cells,and,above all,therapeutic models that combine these modulation techniques constitute the promising future of PC ***,this study aims to elucidate the main mechanisms of resistance to immunotherapy in PC and new ways of manipulating thi

关键词： Pancreatic cancer Immunotherapy Resistance Tumor microenvironment manipulation Combined immunotherapy

Effect of radiative loss mechanisms on FIR thermometric parameters of Nd^(3+)-doped lithium tellurite glasses

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第7期42卷 1250-1257,I0002页

作者： C.Y.Morassuti A.P.L Silva L.A.O.Nunes S.M.Lima L.H.C.Andrade Optical and Photothermal Spectroscopy Group(GEOF) Center for Studies in Natural Resources(CERNA)State University of Mato Grosso do Sul(UEMS)C.P.351DouradosMSBrazil Renato Archer Information Technology Center Dom Pedro I Highway(SP-65)Km 1436-Chácaras Campos dos AmaraisCampinasSPBrazil Institute of Physics of São Carlos University of São PauloSão CarlosSPBrazil

Nd^(3+)-doped tellurite glasses are promising materials for thermometers based on the fluorescence intensity ratio(FIR)***,at high Nd^(3+)concentrations,energy transfer(ET)processes such as optical reabsorption and cross-relaxation can affect the Nd^(3+)emission,which has been little explored in the ***,the present work investigated the use of Nd^(3+)-doped tellurite glass(samples doped with Nd^(3+)at 0.2 mol%,0.5 mol%,2.0 mol%,and 4.0 mol%)in fluorescence thermometers,in the temperature range from 299 to 371 *** results indicate a strong dependence of the FIR parameters on the Nd^(3+)concentration,due to changes in the emission band profiles caused by optical reabsorption of the Nd^(3+)emissions and cross-relaxation processes.A decrease of the relative sensitivity of the ratio^(4)F_(5/2)→^(4)I_(9/2)/^(4)F_(3/2)→^(4)I_(9/2)is observed for samples doped with higher amounts of Nd^(3+).The maximum relative sensitivity at 299 K is 3.00%/K,which is the highest value among the reported Nd^(3+)ions.

关键词： Nd^(3+)-doped tellurite glass Fluorescence intensity ratio Optical thermometry Judd-Ofelt Rare earths

Artemisia vulgaris Induces Tumor-Selective Ferroptosis and Necroptosis via Lysosomal Ca^(2+) Signaling

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6期30卷 525-533页

作者： Lucas dos Santos Zamarioli Michele Rosana Maia Santos Adolfo Garcia Erustes Vanessa Marques Meccatti Thais Cristine Pereira Soraya S Smaili Maria Cristina Marcucci Carlos Rocha Oliveira Gustavo JS Pereira Claudia Bincoletto Department of Pharmacology Paulista School of MedicineFederal University of São PauloSão PauloSP04044-020Brazil Research Group on Phytocomplexes and Cell Signaling School of Health SciencesAnhembi Morumbi UniversitySão PauloSP03164-000Brazil Department of Biosciences and Oral Diagnosis Institute of Science and TechnologySão Paulo State University(ICT-UNESP)São PauloSP12231-280Brazil

Objective To evaluate the chemical composition and effects of Artemisia vulgaris(AV)hydroalcoholic extract(HEAV)on breast cancer cells(MCF-7 and SKBR-3),chronic myeloid leukemia(K562)and NIH/3T3 *** Phytochemical analysis of HEAV was done by high-performance liquid chromatography-mass(HPLC)*** and cell death studies were performed using trypan blue and Annexin/FITC-7AAD,***-1(Fer-1)and necrostatin-1(Nec-1)were used to assess the mode of HEAV-induced cell death and acetoxymethylester(BAPTA-AM)was used to verify the involvement of cytosolic calcium in this *** calcium measurements were made using *** HEAV decreased the viability of MCF-7,SKBR-3 and K562 cells(P<0.05).The viability of HEAV-treated K562 cells was reduced compared to HEAV-exposed fibroblasts(P<0.05).Treatment of K562 cells with HEAV induced cell death primarily by late apoptosis and necrosis in assays using annexin V-FITC/7-AAD(P<0.05).The use of Nec-1 and Fer-1 increased the viability of K562 cells treated with HEAV relative to cells exposed to HEAV alone(P<0.01).HEAV-induced Ca^(2+)release mainly from lysosomes in K562 cells(P<0.01).Furthermore,BAPTA-AM,an intracellular Ca^(2+)chelator,decreased the number of non-viable cells treated with HEAV(P<0.05).Conclusions HEAV is cytotoxic and activates several modalities of cell death,which are partially dependent on lysosomal release of Ca^(2+).These effects may be related to artemisinin and caffeoylquinic acids,the main compounds identified in HEAV.

关键词： Artemisia vulgaris necroptosis ferroptosis late apoptosis Ca^(2+)signaling