检索结果-南通市图书馆

Signal Transduction and Targeted Therapy 2024年第5期9卷 1793-1795页

作者： tobias Langenhan Rudolf Schönheimer Institute of Biochemistry Division of General BiochemistryMedical FacultyLeipzig UniversityLeipzigGermany Comprehensive Cancer Center Central Germany(CCCG) Leipzig UniversityLeipzigGermany Institute of Biology Faculty of Life SciencesLeipzig UniversityLeipzigGermany

A recent report has uncovered a fascinating aspect of how neurons utilize alternative splicing of transcripts of an adhesion G protein-coupled receptor(aGPCR)gene to serve specific functions in the life of a synapse.1 The work provides significant insight into the ability of cells to support distinct biochemical and physiological operations through post-transcriptional processing of genetic information that is encoded in a single aGPCR locus.

关键词： GPCR utilize operations

Extension of Flow Behaviour and Damage Models for Cast Iron Alloys with Strain Rate Effect

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第3期37卷 297-310页

作者： Chuang Liu Dongzhi Sun Xianfeng Zhang Florence Andrieux tobias Gersterc School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China Fraunhofer Institute for Mechanics of Materials(IWM) 79108 FreiburgGermany Fraunhofer Institute for High Speed Dynamics Ernst-Mach-Institute(EMI)79104 FreiburgGermany

Cast iron alloys with low production cost and quite good mechanical properties are widely used in the automotive *** study the mechanical behavior of a typical ductile cast iron(GJS-450)with nodular graphite,uni-axial quasi-static and dynamic tensile tests at strain rates of 10^(-4),1,10,100,and 250 s^(-1)were carried *** order to investigate the influence of stress state on the deformation and fracture parameters,specimens with various geometries were used in the *** strain curves and fracture strains of the GJS-450 alloy in the strain rate range of 10^(-4)to 250 s^(-1)were obtained.A strain rate-dependent plastic flow model was proposed to describe the mechanical behavior in the corresponding strain-rate *** available damage model was extended to take the strain rate into account and calibrated based on the analysis of local fracture *** with the proposed plastic flow model and the damage model were conducted to observe the deformation and fracture *** results show that the strain rate has obviously nonlinear effects on the yield stress and fracture strain of GJS-450 *** predictions with the proposed plastic flow and damage models at various strain rates agree well with the experimental results,which illustrates that the rate-dependent plastic flow and damage models can be used to describe the mechanical behavior of cast iron alloys at elevated strain *** proposed plastic flow and damage models can be used to describe the deformation and fracture analysis of materials with similar properties.

关键词： Dynamic behavior of materials Strain rate dependency Damage model Voce model Cast iron

64-row multi-dector computed tomography coronary image from a center with early experience: first illustration of learning curve

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 Geriatric Cardiology 2006年第1期3卷 29-34页

作者： Sze Piaw CHIN Tiong Kiam ONG Chee Khoon LIEW M.tobias seyfarth Fong Yean Yip ALAN Houng Bang LIEW Kui Hian SIM Dept of Cardiology Sarawak General Hospital Siemens Cardiac Solutions Erlangen Germany

Background and objectives The recent joint ACCF/AHA clinical competence statement on cardiac imaging with multi-detector computed tomography recommended a minimum of 6 months training and 300 contrast examinations, of which the candidate must be directly involved in at least 100 studies. Whether this is adequate to become proficient in interpretation of coronary computed tomogsignificant coronary stenosis in a center with 1 year's experience using a 64-row scanner. Methods A total of 778 patients underwent contrast-enhanced CTA between January and December 2005. Out of these patients, 301 patients also underwent contrast-enhanced conventional coronary angiography (CCA). These patients were divided into 4 groups according to the time the examination was underwent. Group Q1: first quarter of the year (n=20), Group Q2: second quarter (n=128), Group Q3: third quarter (n=134), and Group Results The sensitivity, specificity, positive, and negative predictive values were Q1 - 64%, 89%, 49% and 94%, respectively; Q2 -79%, 96%, 74% and 97%, respectively; Q3 - 78%, 96%, 74%, 97%, respectively, and Q4 - 100% for all. Conclusions In a center with formal training and high caseload, our accuracy in CTA analysis reached a plateau after 6 months experience. Test-bolus protocols produce better image quality and can improve accuracy. New centers embarking on CTA will need to overcome an initial 6-month learning curve depending upon the caseload during which time they should consider correlation with CCA.

关键词： computed tomography training angiography coronary artery disease

Feasibility and accuracy of coronary imaging in elderly patients using the 64-row multi-detector computed tomography: a correlation study with conventional coronary angiography

在线全文

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2006年第1期3卷 9-14页

作者： Chee Khoon LIEW Sze Piaw CHIN Tiong Kiam ONG seyfarth tobias Yean Yip FONG Choon Kiat ANG Houng Bang LIEW Rapaee ANNUAR Kui Hian SIM Deptartment of Cardiology Sarawak General Hospital SarawakMalaysia Siemens Cardiac Solutions Erlangen Germany Universitv Malaysia Sarawak Malaysia

Background Elderly patients generally have higher occurrence of coronary calcification, increased heart rate and difficulty with prolonged breath-holding. The aim of our study was to investigate the feasibility and accuracy of using 64-row multi-detector computed tomography (MDCT) in the assessment of coronary artery stenoses in elderly patients. Methods One hundred and fifty two patients with suspected or known coronary artery disease were divided into 4 groups according to their age (Group A: 40-49 years,n=34; Group B: 50-59 years, n=57; Group C: 60-69 years, n=48; Group D: 70 years and above; n=13). Coronary CT angiography (CTA) using a 64-row MDCT was performed and the findings were compared with that of conventional coronary angiography (CCA).Using axial images, multi-planar reconstructions (MPR) and maximum intensity projections (MIP), coronary segments of lumen diameter = 1.5mm were analyzed for the presence of significant stenosis (= 50% ). Results Percentages of poor image quality from coronary CTA preventing reliable correlations with CCA were 21%, 14%, 19% and 62% in Groups A to D respectively. Patients in Group D had significantly higher calcium scores compared with the other groups (P＜0.001). In patients where CTA images were of acceptable quality, percentages of accurate correlations with CCA were 89.8%, 93.4%, 86.6% and 78.0% for Groups A to D *** were no significant difference in serum creatinine, heart rate and contrast volume between the 4 groups. Conclusions The 64-row MDCT coronary angiography was less accurate and feasible for patients aged 70 years or above due to heavy coronary calcification and inability to perform a satisfactory breath-hold. However, a high diagnostic accuracy with the MDCT is possible in patients aged less than 70 years.

关键词： computed tomography angiography coronary artery disease elderly

Assessment of left ventricular ejection fraction: comparison of two dimensional echocardiography, cardiac magnetic resonance imaging and 64-row multi-detector computed tomography

在线全文

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2006年第1期3卷 2-8页

作者： Chee Khoon LIEW Rapaee ANNUAR Tiong Kiam ONG Sze Piaw CHIN tobias seyfarth Yean Yip FONG Choon Kiat ANG Houng Bang LIEW Kui Hian SIM Department of Cardiology Sarawak General Hospital Sarawak Malaysia University Malaysia Sarawak Siemens Cardiac Solutions Erlangen Germany Department of Cardiology Sarawak General Hospital SarawakMalaysia

Objectives To compare left ventricular ejection fraction (LVEF) determined from 64-row multi-detector computed tomography (64-row MDCT) with those determined from two dimensional echocardiography (2D echo) and cardiac magnetic resonance imaging (CMR). Methods Thirty-two patients with coronary artery disease underwent trans-thoracic 2D echo, CMR and contrast-enhanced 64-row MDCT for assessment of LVEF within 48 hours of each other. 64-row MDCT LVEF was derived using the Syngo Circulation software; CMR LVEF was by Area Length Ejection Fraction (ALEF) and Simpson method and 2D echo LVEF by Simpson *** The LVEF was 49.13 ± 15.91% by 2D echo, 50.72 ± 16.55% (ALEF method) and 47.65 ± 16.58%(Simpson method) by CMR and 50.00 ± 15.93% by 64-row MDCT. LVEF measurements by 64-row MDCT correlated well with LVEF measured with CMR using either the ALEF method (Pearson correlation r = 0.94, P ＜0.01) or Simpson method (r = 0.92, P＜0.01). It also correlated well with LVEF measured using 2D echo (r = 0.80, P ＜ 0.01). Conclusion LVEF measurements by 64-row MDCT correlated well with LVEF measured by CMR and 2D echo. The correlation between 64-row MDCT and CMR was better than the correlation between 2D echo with CMR. Standard data set from a 64-row MDCT coronary study can be reliably used to calculate the LVEF.

关键词： ejection fraction echocardiography magnetic resonance imaging computed tomography

Hyper spectral resolution stimulated Raman spectroscopy with amplified fs pulse bursts

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第3期13卷 566-576页

作者： Hongtao Hu tobias Flöry Vinzenz Stummer Audrius Pugzlys Markus Zeiler Xinhua Xie Aleksei Zheltikov Andrius Baltuška Photonics Institute Technische Universität WienGußhausstraße 27-29Vienna A-1040Austria SwissFEL Paul Scherrer InstituteVilligen PSI 5232Switzerland Institute for Quantum Science and Engineering Department of Physics and AstronomyTexas A&M UniversityCollege StationTX 77843USA

We present a novel approach for Stimulated Raman Scattering(SRS)spectroscopy in which a hyper spectral resolution and high-speed spectral acquisition are achieved by employing amplified offset-phase controlled fs-pulse *** investigate the method by solving the coupled non-linear Schrödinger equations and validate it by numerically characterizing SRS in molecular nitrogen as a model *** spectral resolution of the method is found to be determined by the inverse product of the number of pulses in the burst and the intraburst pulse *** SRS spectrum is obtained through a motion-free scanning of the offset phase that results in a sweep of the Raman-shift *** to high spectral resolution and fast motion-free scanning the technique is beneficial for a number SRS-based applications such as gas sensing and chemical analysis.

关键词： compound spectral resolution

The Structure of Gravity Funnels and Stability Considerations of Matter in SI Units

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 High Energy Physics, Gravitation and Cosmology 2024年第1期10卷 71-81页

作者： tobias Bartusch Bartusch Plasma and Vacuum Kissing Germany

This article describes an extension of the theory of vortices to electromagnetic types with a start point from known fluid systems. From this, properties of gravity-generating objects (particles and black holes) can be derived, which can also describe their possible interior. This also leads to questions about stability, which are then addressed and ultimately lead to considerations of black holes and their possible internal structure. The results fit into the observable areas and can also be directly verified because they were analytically calculated in SI units.

关键词： Black Hole Dark Matter Electromagnetic Gravity Singularity Vortex

Calcium channels caught in peripheral glia’s tug-of-war on axon regeneration in Drosophila

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 2025年第2期20卷 475-476页

作者： Jackson Powell tobias Steinschaden Rose Horowitz Yuanquan Song Raymond G.Perelman Center for Cellular and Molecular Therapeutics The Children’s Hospital of PhiladelphiaPhiladelphiaPAUSA The Neuroscience Graduate Group University of PennsylvaniaPhiladelphiaPAUSA Department of Pathology and Laboratory Medicine University of PennsylvaniaPhiladelphiaPAUSA Medical University of Vienna Center for Brain ResearchDepartment of NeuroimmunologyViennaAustria

Neural damage or degeneration is at the crux of many diseases,and treatment of these diseases will require the development of therapeutics to enhance and guide neural *** intrinsic and extrinsic factors dictate a neuron’s ability to regenerate,and the combination of these factors results in the great regenerative capacity of the peripheral nervous system(PNS)and the poor regenerative capacity of the central nervous system(CNS)following *** the core of a neuron’s function is its ability to relay electrochemical signals,and a neuron’s excitability is a key factor in its ability to *** works have focused on the changes in neuronal electrophysiological properties,firing patterns,and ion flux after injury,which differentially activate signaling pathways at the core of *** role of glia in neuron regeneration has long been studied.

关键词： degeneration firing system

Impact of exercise on markers of B cell-related immunity:A systematic review

在线全文

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2024年第3期13卷 339-352,I0002页

作者： David Walzik Sergen Belen Karen Wilisch Marie Kupjetz Silvana Kirschke tobias Esser Niklas Joisten Alexander Schenk Sebastian Proschinger Philipp Zimmer Division of Performance and Health(Sports Medicine) Institute for Sport and Sport ScienceTU Dortmund UniversityDortmund 44227Germany

Background:B cells represent a crucial component of adaptive immunity that ensures long-term protection from infection by generating pathogen-specific *** alters B cell counts and immunoglobulin levels,but evidence-based conclusions on potential benefits for adaptive immunity are *** systematic review assessed current literatures on the impact of acute exercise and exercise training on B cells,immunoglobulins,and markers of secretory immunity in human ***:According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines,MEDLINE,Web of Science,and Embase were searched on March 8,***-randomized controlled trials and crossover trials investigating the impact of acute exercise or exercise training on B cell counts and proportions,immunoglobulin levels,salivary flow rate,or secretory immunoglobulin A secretion rate were *** and reporting of exercise training studies were assessed using the Tool for the Assessment of Study Quality and reporting in *** characteristics,outcome measures,and statistically significant changes were summarized ***:Of the 67 eligible studies,22 applied acute exercise and 45 applied exercise *** included outcomes revealed significant alterations over time in acute exercise and exercise training context,but only a few investigations showed significant differences compared to control *** and plasma immunoglobulin A levels were most consistently increased in response to exercise ***:B cell-related outcomes are altered by acute exercise and exercise training,but evidence-based conclusions cannot be drawn with high confidence due to the large heterogeneity in populations and exercise ***-designed trials with large sample sizes are needed to clarify how exercise shapes B cell-related immunity.

关键词： Antibody B-lymphocyte Exercise Humoral immunity Immune system

Smart Approaches to Efficient Text Mining for Categorizing Sexual Reproductive Health Short Messages into Key Themes

在线全文

学校读者我要写书评

暂无评论

Open Journal of Applied Sciences 2024年第2期14卷 511-532页

作者： tobias Makai Mayumbo Nyirenda Department of Computer Science University of Zambia Lusaka Zambia

To promote behavioral change among adolescents in Zambia, the National HIV/AIDS/STI/TB Council, in collaboration with UNICEF, developed the Zambia U-Report platform. This platform provides young people with improved access to information on various Sexual Reproductive Health topics through Short Messaging Service (SMS) messages. Over the years, the platform has accumulated millions of incoming and outgoing messages, which need to be categorized into key thematic areas for better tracking of sexual reproductive health knowledge gaps among young people. The current manual categorization process of these text messages is inefficient and time-consuming and this study aims to automate the process for improved analysis using text-mining techniques. Firstly, the study investigates the current text message categorization process and identifies a list of categories adopted by counselors over time which are then used to build and train a categorization model. Secondly, the study presents a proof of concept tool that automates the categorization of U-report messages into key thematic areas using the developed categorization model. Finally, it compares the performance and effectiveness of the developed proof of concept tool against the manual system. The study used a dataset comprising 206,625 text messages. The current process would take roughly 2.82 years to categorise this dataset whereas the trained SVM model would require only 6.4 minutes while achieving an accuracy of 70.4% demonstrating that the automated method is significantly faster, more scalable, and consistent when compared to the current manual categorization. These advantages make the SVM model a more efficient and effective tool for categorizing large unstructured text datasets. These results and the proof-of-concept tool developed demonstrate the potential for enhancing the efficiency and accuracy of message categorization on the Zambia U-report platform and other similar text messages-based platforms.

关键词： Knowledge Discovery in Text (KDT) Sexual Reproductive Health (SRH) Text Categorization Text Classification Text Extraction Text Mining Feature Extraction Automated Classification Process Performance Stemming and Lemmatization Natural Language Processing (NLP)