检索结果-南通市图书馆

Stress granules: friend or foe in neurodegenerative disorders?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第2期19卷 403-404页

作者： Shanshan Xu Nico p.Dantuma Department of Cell and Molecular Biology(CMB) Karolinska InstitutetSolnavägen 9S-17165 StockholmSweden

Neurodegenerative diseases,such as Alzheimer’s disease,parkinson’s disease,and amyotrophic lateral sclerosis,despite the diversity in clinical symptoms,share a striking feature at the cellular level:the accumulation of insoluble aggregates of misfolded proteins that are sequestered in intraneuronal inclusion *** mutations in disease-associated proteins that render them aggregation-prone,the decline of protein homeostasis(***)with aging is also believed to be a contributing factor to the accumulation of protein aggregates.

关键词： degenerative homeostasis clinical

维普期刊数据库

Unveiling the culprit:the fusobacterium lineage that populates colorectal cancer

在线全文

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2024年第6期9卷 2349-2350页

作者： Johannes Betge Matthias p.Ebert Department of Medicine Ⅱ Medical Faculty MannheimHeidelberg UniversityMannheimGermany Junior Clinical Cooperation Unit Translational Gastrointestinal Oncology and preclinical Models German Cancer Research Center(DKFZ)HeidelbergGermany DKFZ Hector Cancer Institute at University Medical Center MannheimGermany MMpU Microbiota Drug Metabolism and Cancer Therapy European Molecular Biology LaboratoryHeidelbergGermany

In a recent study published in Nature,Zepeda-Rivera et al.1 discovered that one distinct clade of Fusobacterium nucleatum animalis(Fna)dominates the colorectal cancer(CRC)tumor *** work unravels a more precise understanding of a major bacterial species associated with CRC progression,thereby establishing a new focus for future studies,which may aid to develop improved microbiome-based diagnostics and treatments(Fig.1).

关键词： colorectal al. cancer

proteins as nanomagnets and magnetoreceptors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Zoological Research 2024年第4期45卷 831-832页

作者： p.J.Hore Department of Chemistry University of OxfordUK

It is an appealing notion that a protein molecule could act as a nanomagnet.A genetically encodable biomolecule with a permanent magnetic moment at room temperature could have a range of applications:a magnetogenetic actuator,a magnetic tag for purifying and immobilizing enzymes,a contrast agent for magnetic resonance imaging,and a basis for a biomimetic magnetic sensing device,to name just a few.A magnetic protein could perhaps also function as the sensor in the magnetic compass that enables small songbirds to navigate the huge distances between their breeding and wintering *** though such possibilities may be,how realistic are they?

关键词： magnetic magnets enable

维普期刊数据库

The great catastrophe: causes of the permo-Triassic marine mass extinction

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第1期11卷 37-50页

作者： paul B.Wignall David p.G.Bond School of Earth & Environment University of Leeds School of Environmental Sciences University of Hull

The marine losses during the permo-Triassic mass extinction were the worst ever experienced. All groups were badly affected, especially amongst the benthos(e.g. brachiopods, corals, bryozoans, foraminifers,ostracods). planktonic populations underwent a fundamental change with eukaryotic algae being replaced by nitrogen-fixing bacteria, green-sulphur bacteria, sulphate-reducing bacteria and prasinophytes. Detailed studies of boundary sections, especially those in South China, have resolved the crisis to a ～55 kyr interval straddling the permo-Triassic boundary. Many of the losses occur at the beginning and end of this interval painting a picture of a two-phase extinction. Improved knowledge of the extinction has been supported by numerous geochemical studies that allow diverse proposed extinction mechanisms to be studied. A transition from oxygenated to anoxic-euxinic conditions is seen in most sections globally, although the intensity and timing shows regional variability. Decreased ocean ventilation coincides with rapidly rising temperatures and many extinction scenarios attribute the losses to both anoxia and high *** kill mechanisms include ocean acidification for which there is conflicting support from geochemical proxies and, even less likely, siltation(burial under a massive influx of terrigenous sediment) which lacks substantive sedimentological evidence. The ultimate driver of the catastrophic changes at the end of the permian was likely Siberian Trap eruptions and their associated carbon dioxide emissions with consequences such as warming, ocean stagnation and acidification. Volcanic winter episodes stemming from Siberian volcanism have also been linked to the crisis, but the short-term nature of these episodes(pid warming during the crisis makes this an unlikely cause. Finally, whilst the extinction is well studied in equatorial latitudes, a different history is found in northern Boreal latitudes

关键词： ocean anoxia ocean acidification siltation productivity collapse volcanic winter

Experimental investigation of radiative heat propagation in a simplified generic packed bed

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

particuology 2024年第5期88卷 149-160页

作者： Matthias Tyslik Lukas pörtner Siegmar Wirtz Martin Schiemann Institute of Energy plant Technology Ruhr-University Bochum44780 BochumGermany

A novel test rig for the investigation of radiative heat transfer in packed beds has been developed and is introduced with representative experimental *** individual components and the calibration are *** generic packed bed is realized in a simplified way by an arrangement of parallel rods,which represent particles in *** this arrangement,electrically heated rods provide the radiation propagating through the rod array to heat the passive counterparts.A sophisticated temperature-control scheme with a large number of thermocouples and infrared-imaging provides in-depth information about heat transfer in the *** radiation intensities are determined with a Fourier-transform infrared spectroscopy,which has been modified and validated for this specific *** order to compare the influence of different surface properties of particles on the heat propagation and surface reflections,rod samples made of stainless steel and magnesium oxide are *** influence of material properties becomes clearly visible by comparing the high radiation intensities resulting from a stainless steel rod array to the same geometry built from magnesium oxide *** addition,the influence of the surface properties is particularly evident in the infrared images since the reflections are significantly higher for the stainless steel samples than for the magnesium oxide *** experimental results in the current work demonstrate the ability of the test rig to provide data with a well-defined accuracy as a validation base for numerical radiation simulations in packed beds.

关键词： Thermal radiation Spectral reflections Fourier-transform infrared spectroscopy

Constraining the variable generalized Chaplygin gas model in matter creation cosmology

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2024年第10期76卷 121-136页

作者： Yogesh Bhardwaj C p Singh Department of Applied Mathematics Delhi Technological University

We explore the variable generalized Chaplygin gas（VGCG） model in the theory of matter creation cosmology within the framework of a spatially homogeneous and isotropic flat Friedmann—Lemai tre—Robertson—Walker space-time. Matter creation cosmology is based on reinterpretation of the energy–momentum tensor in Einstein's field equations. This creation corresponds to an irreversible energy flow from the gravitational field to the created matter constituents. The variable Chaplygin gas（VCG） is also studied as a particular solution. We use the Markov chain Monte Carlo method to constrain the free parameters of three models, namely,Lambda-Cold-Dark matter（ΛCDM）, VGCG and VCG models with and without matter creation from the latest observational data from baryon acoustic oscillations, cosmic chronometer, type Ia supernovae（pantheon） including gamma-ray bursts, quasars and the local measurement of H0from R21 data. Two different combinations of dataset provide a fairly tight constraint on the parameters of the ΛCDM, VGCG and VCG models. The present values of various cosmological parameters are obtained, which are very close to the ΛCDM model. Furthermore, we perform stability analysis, Bayesian evidence analysis and information criteria analysis for these models through studying the sound speed, Bayes factor, and Akaike information criteria（AIC） and Bayesian information criteria（BIC） selection criteria. The values of sound speed for VGCG and VCG models shows that both the models are stable. According to AIC, it is observed that VGCG and VCG models with matter creation are supported considerably less by current observations,while BIC shows that these models are not favoured by observational data.

关键词： Chaplygin gas model cosmological model dark energy matter creation

Risk Factors Associated with Unsuccessful Vaginal Birth after One Cesarean (VBAC-1) in puerto Rico

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Obstetrics and Gynecology 2024年第6期14卷 888-902页

作者： Irazú Guinan Marjorie Suárez Fabiola Angulo Luis Mayol paula Suárez Lisandris Dominicci Nathalie Chang Saribel Torres Antonio Rodríguez Raymond L. Tremblay Maricarmen Colón-Díaz Department of physiology and pathology San Juan Bautista School of Medicine Caguas USA

Background: Cesarean section (CS) has increased steadily over the last decade, with an estimated one-third of women delivering by cesarean section worldwide. Objective: Our study aimed to investigate the demographic and associated factors influencing vaginal birth after one cesarean (VBAC-1) success focusing on variables like pre-pregnancy BMI, diabetes, hypertension, education, and smoking. Study Design and Methods: In this retrospective study, we analyzed 285 cases (81 unsuccessful VBAC-1, 204 successful VBAC-1) from San Juan City Hospital (puerto Rico) between January 1, 2019, and December 31, 2020. We used odds ratios and model selection comparison to assess the impact of variables on successful VBAC-1, using a significance threshold of 95% CI. Model selection assessed binomial model combinations using a generalized linear approach to identify key risk factors. Results: Unsuccessful VBAC-1 (a repeat cesarean), was associated with diabetes (OR: 0.376, p = 0.086), hypertension (OR: 0.23, p = 0.006), and university-educated women (OR: 1.372, p = 0.711). High school-educated women had an OR of 3.966 (p = 0.105), while overweight women were 0.481 times more likely to have unsuccessful VBAC-1 (p = 0.041). Significant associations were not found with obesity (OR: 0.574, p = 0.122), underweight/normal (OR: 1.01, p = 0.810), or smoking (OR: 1.227, p = 0.990). Conclusion: Results revealed women with higher education levels, hypertension, or diabetes are less likely to have a successful VBAC-1. Understanding the complex interactions affecting these outcomes is aimed at establishing guidelines for healthcare professionals to conduct systematic risk/benefit assessments. This study lays a foundation for evidence-based practices and policies, offering initial insights into VBAC-1 success factors in puerto Rico.

关键词： Diabetes Hypertension Obesity Trial of Labor Vaginal Birth after Cesarean

Exploring the potential of drill cuttings for reservoir characterization:A case study from the Volga-Ural basin,Russia

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

petroleum Research 2024年第2期9卷 193-205页

作者： Ibrahem Yousef V.p.Morozov Kazan Federal University Institute of Geology and Petroleum Technologies420008Russian Federation

The research objectives are to assess the possibility of using drill cutting analysis to obtain information about the mineralogical and geochemical properties of the reservoir *** cutting samples were collected from a vertical well that penetrated the Domanik sediments(Semiluksk Formation)in one of the oil fields in the Volga-Ural petroleum *** sections from drill cuttings were examined using an optical polarizing microscope(Axio Imager A2).X-ray diffraction(XRD)analyses were performed using a Brucker D2 phaser X-ray powder *** properties were studied using an STA 449 F3 Jupiter *** pyrolytic studies were performed using the Rock-Eval *** inspection showed that the studied sediments are alternations of carbonates and siliceous-carbonate *** section examinations revealed that the carbonates are mainly limestone(mudstone and wackestone)and are characterized by a dense texture and up to 30%organic *** siliceous-carbonate rocks are dominated by siliceous mudstones and are characterized by dark colours,layered structure,and an enrichment in organic *** analyses showed that the carbonate rocks are mainly composed of calcite,dolomite,quartz,feldspar,and mica,which are minor *** siliceous-carbonate rocks are dominated by quartz,followed by calcite,although they also contain feldspars,mica,dolomite,and pyrite as *** to the simultaneous thermal analysis,the average total hydrocarbon in the carbonate and siliceous-carbonate rocks is 13.6%(for the core samples)and 11.5%(for the drill cutting samples).The content of heavy hydrocarbons in the rocks is higher than the content of light hydrocarbons,indicating the immature nature of organic *** is found sporadically in siliceous-carbonate *** to the pyrolytic studies,average S1 is 4.4 mg/g and average S2 is 19.8 mg/g(for the core samples);average S1 is 2.1 mg/g and average S2 is 17.8 mg/g(for the

关键词： Drill cuttings Reservoir characterization Domanik Semiluksk Volga-Ural Russia

A Hybrid Machine Learning Approach for Improvised QoE in Video Services over 5G Wireless Networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第3期78卷 3195-3213页

作者： K.B.Ajeyprasaath p.Vetrivelan School of Electronics Engineering Vellore Institute of TechnologyChennaiTamil Nadu600127India

Video streaming applications have grown considerably in recent *** a result,this becomes one of the most significant contributors to global internet *** to recent studies,the telecommunications industry loses millions of dollars due to poor video Quality of Experience(QoE)for *** the standard proposals for standardizing the quality of video streaming over internet service providers(ISps)is the Mean Opinion Score(MOS).However,the accurate finding of QoE by MOS is subjective and laborious,and it varies depending on the user.A fully automated data analytics framework is required to reduce the inter-operator variability characteristic in QoE *** work addresses this concern by suggesting a novel hybrid XGBStackQoE analytical model using a two-level layering *** one combines multiple Machine Learning(ML)models via a layer one Hybrid *** ML models at level one are trained using the entire training data *** level two Hybrid XGBStackQoE-Model is fitted using the outputs(meta-features)of the layer one ML *** proposed model outperformed the conventional models,with an accuracy improvement of 4 to 5 percent,which is still higher than the current traditional *** proposed framework could significantly improve video QoE accuracy.

关键词： Hybrid XGBStackQoE-model machine learning MOS performance metrics QoE 5G video services