检索结果-南通市图书馆

Does shifting to professional emergency department staffing affect the decision for chest radiography?

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Emergency Medicine 2021年第2期12卷 87-92页

作者： Marin Pavlov Lucija Klobucar Iva Klobučar Kristinazgela Vesna Degoricija Department of Cardiology Sestre Milosrdnice University Hospital CentreZagreb 10000Croatia Institute of Emergency Medicine Osijek-Baranja CountyOsijek 31000Croatia University of Zagreb School of Medicine Zagreb 10000Croatia Department of Medicine Sestre milosrdnice University Hospital CentreZagreb 10000Croatia

BACKGROUND: The study aims to determine whether shifting to professional emergency department(ED) teams leads to a higher rate of radiologic ***: We retrospectively analyzed a total of 2,000 patients presenting to the ED of a tertiary teaching hospital in two time periods: group 1(G1) comprised 1,000 consecutive patients enrolled from December 21, 2012 to January 5, 2013(all patients were examined by an internal medicine specialist);group 2(G2) comprised 1,000 consecutive patients enrolled from December 21, 2018 to January 3, 2019(all patients were examined by an emergency physician).RESULTS: The chest X-ray(CXR) was performed in 40.6% of all patients. There was no difference in the frequency of CXR(38.9% in G1 vs. 42.3% in G2, P=0.152). More CXRs were performed in G2 patients older than 65 years, in female patients older than 65 years, in patients presenting during the evening and night shifts or off-hours, in patients with a history of malignancy, in patients with gastrointestinal bleeding, and in patients with bradycardia, but fewer in patients presenting with arrhythmia. No difference in the rates of pathological CXR was found(47.3% in G1 vs. 52.2% in G2, P=0.186). Compared with G2, higher sensitivity and specificity were obtained for the binary logistic regression model predicting pathological findings in ***: Shifting to professional ED teams does not increase radiologic workup. By implementing deliberate usage of ultrasound, some self-governing procedures, case-oriented investigations, and center-specific recommendations, unnecessary radiologic workup can be avoided. Professional ED teams could lead to a higher standard of emergency care.

关键词： Chest radiography Emergency department Emergency physicians Healthcare organization

Review: Neuronal Differentiation Protocols of Mesenchymal Stem Cells

在线全文

学校读者我要写书评

暂无评论

Advances in Bioscience and Biotechnology 2022年第1期13卷 15-71页

作者： Miguel A. Jiménez-Acosta Lory Jhenifer Rochín Hernández Mayte Lizeth Padilla Cristerna José Tapia-Ramírez Marco A. meraz-Ríos Department of Molecular Biomedicine Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Instituto Politécnico Nacional México City México Department of Genetic and Molecular Biology Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Instituto Politécnico Nacional México City México

Mesenchymal stem cells (MSCs) are self-renewing cells found in almost all postnatal organs and tissues in the perivascular region. These cells present multiple characteristics that make them candidates to be applied in cell therapy for neurodegenerative diseases, such as their secretory action, migration to the lesion area, and immunomodulatory potential. These cells have a high capacity for mesodermal differentiation;however, numerous studies have shown that MSCs can also differentiate into neurons. However, despite positive results in multiple trials in which undifferentiated MSCs transplanted into animal models of neurodegenerative diseases, some studies suggest that the therapeutic effects obtained are enhanced by the use of MSCs differentiated towards the neuronal lineage before transplant. In this sense, there are several methods to induce in vitro reprogramming of MSCs towards the neuronal lineage, including chemical substances, growth factors, cocultures with neural lineage cells, transfection of genes, miRNAs, etc., and small molecules stand out. Therefore, this article compares multiple experimental tests in which these inducers promote neuronal differentiation of MSCs and identify those methods that originate an optimal neuronal differentiation. The analysis includes the percentage of differentiation, maturation, expression of neuronal markers, functionality, and cell survival considering the intrinsic characteristics of the MSCs used as the tissue of origin and the species from which they were isolated.

关键词： Mesenchymal Stem Cells Transdifferentiating Neuronal Differentiation Small Molecules miRNA Neural Induction

Systematic investigation of millimeter-wave optic modulation performance in thin-film lithium niobate

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

Photonics Research 2022年第10期10卷 2380-2387页

作者： YIWEN ZHANG LINBO SHAO JINGWEI YANG ZHAOXI CHEN KE ZHANG KAM-MAN SHUM DI ZHU CHI HOU CHAN MarKO LONČar CHENG WANG Department of Electrical Engineering City University of Hong KongKowloonHong KongChina John A.Paulson School of Engineering and Applied Sciences Harvard UniversityCambridgeMassachusetts 02138USA Bradley Department of Electrical and Computer Engineering Virginia TechBlacksburgVirginia 24061USA State Key Laboratory of Terahertz and Millimeter Waves City University of Hong KongKowloonHong KongChina Institute of Materials Research and Engineering Agency for ScienceTechnology and Research(A^(*)STAR)Singapore 138634Singapore

Millimeter-wave(mmWave)band(30–300 GHz)is an emerging spectrum range for wireless communication,short-range radar,and sensor ***-optic modulators that could efficiently convert mmWave signals into the optical domain are crucial components for long-haul transmission of mmWave signals through optical *** these ultrahigh frequencies,however,the modulation performances are highly sensitive to the transmission line loss as well as the velocity-and impedance-matching conditions,while precise measurements and modeling of these parameters are often *** we present a systematic investigation of the mmWave-optic modulation performances of thin-film lithium niobate modulators through theoretical modeling,electrical verifications,and electro-optic measurements at frequencies up to 325 *** on our experimentally verified model,we demonstrate thin-film lithium niobate mmWave-optic modulators with a measured 3-dB electro-optic bandwidth of 170 GHz and a 6-dB bandwidth of 295 *** device also shows a low RF half-wave voltage of 7.3 V measured at an ultrahigh modulation frequency of 250 *** work provides a comprehensive guideline for the design and characterization of mmWave-optic modulators and paves the way toward future integrated mmWave photonic systems for beyond-5G communication and radar applications.

关键词： millimeter lithium film

Robust Designs Through Risk Sensitivity:An Overview

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2021年第5期34卷 1634-1665页

作者： BASar Tamer Coordinated Science Laboratory University of Illinois1308 West MainUrbanaIL 61801USA.

This is an overview paper on the relationship between risk-averse designs based on exponential loss functions with or without an additional unknown(adversarial)term and some classes of stochastic *** particular,the paper discusses the equivalences between risk-averse controller and filter designs and saddle-point solutions of some corresponding risk-neutral stochastic differential games with different information structures for the *** of the by-products of these analyses is that risk-averse controllers and filters(or estimators)for control and signal-measurement models are robust,through stochastic dissipation inequalities,to unmodeled perturbations in controlled system dynamics as well as signal and the measurement *** paper also discusses equivalences between risk-sensitive stochastic zero-sum differential games and some corresponding risk-neutral three-player stochastic zero-sum differential games,as well as robustness issues in stochastic nonzero-sum differential games with finite and infinite populations of players,with the latter belonging to the domain of mean-field games.

关键词： Mean-field games risk-sensitive control risk-sensitive filtering risk-sensitive games risk sensitivity robustness

Growth factor-and cytokine-driven pathways governing liver stemness and differentiation

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第41期16卷 5148-5161页

作者： aránzazu Sánchez Isabel Fabregat School of Pharmacy Complutense University 28040 Madrid Spain Bellvitge Biomedical Research Institute (IDI- BELL) and University of Barcelona Molecular Oncology Laboratory Hospital Duran i Reynals. Gran Via de Hospitalet 199 L' Hospitalet 08907 Barcelona Spain

Liver is unique in its capacity to regenerate in response to injury or tissue loss. Hepatocytes and other liver cells are able to proliferate and repopulate the liver. However, when this response is impaired, the contribution of hepatic progenitors becomes very relevant. Here, we present an update of recent studies on growth factors and cytokine-driven intracellular pathways that govern liver stem/pro-genitor cell expansion and differentiation, and the rel-evance of these signals in liver development, regeneration and carcinogenesis. Tyrosine kinase receptor signaling, in particular, c-Met, epidermal growth factor receptors or fibroblast growth factor receptors, contribute to prolifera-tion, survival and differentiation of liver stem/progenitor cells. Different evidence suggests a dual role for the trans-forming growth factor (TGF)-β signaling pathway in liver stemness and differentiation. On the one hand, TGF-βmediates progression of differentiation from a progenitor stage, but on the other hand, it contributes to the expan-sion of liver stem cells. Hedgehog family ligands are nec-essary to promote hepatoblast proliferation but need to be shut off to permit subsequent hepatoblast differentiation. In the same line, the Wnt family and β-catenin/T-cell fac-tor pathway is clearly involved in the maintenance of liver stemness phenotype, and its repression is necessary for liver differentiation during development. Collectively, data indicate that liver stem/progenitor cells follow their own rules and regulations. The same signals that are essential for their activation, expansion and differentiation are good candidates to contribute, under adequate conditions, to the paradigm of transformation from a pro-regenerative to a pro-tumorigenic role. From a clinical perspective, this is a fundamental issue for liver stem/progenitor cell-based therapies.

关键词： Hepatocyte growth factor Epidermal growth factor Fibroblast growth factor Transforming growth factor-β Hedgehog and β-catenin Liver Stem cell

Mass Balance Modeling for Electric arc Furnace and Ladle Furnace System in Steelmaking Facility in Turkey

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

Journal of Iron and Steel Research(International) 2007年第5期14卷 1-6,55页

作者： smail Ekmeki Ya ar Yetisken nal ■amdali Engineering Faculty Marmara University Gztepe Campus Development Bank of Turkey

In the electric arc furnace （EAF） steel production processes, scrap steel is principally used as a raw material instead of iron ore. In the steelmaking process with EAF, scrap is first melted in the furnace and then the desired chemical composition of the steel can be obtained in a special furnace such as ladle furnace （LF）. This kind of furnace process is used for the secondary refining of alloy steel. LF furnace offers strong heating fluxes and enables precise temperature control, thereby allowing for the addition of desired amounts of various alloying elements. It also provides outstanding desulfurization at high-temperature treatment by reducing molten steel fluxes and removing deoxidation products. Elemental analysis with mass balance modeling is important to know the precise amount of required alloys for the LF input with respect to scrap composition. In present study, chemical reactions with mass conservation law in EAF and LF were modeled altogether as a whole system and chemical compositions of the final steel alloy output can be obtained precisely according to different scrap compositions, alloying elements ratios, and other input amounts. Besides, it was found that the mass efficiency for iron element in the system is 95.93%. These efficiencies are calculated for all input elements as 8. 45% for C, 30.31% for Si, 46.36% for Mn, 30.64% for P, 41.96% for S, and 69.79% for Cr, etc. These efficiencies provide valuable ideas about the amount of the input materials that are vanished or combusted for 100 kg of each of the input materials in the EAF and LF system.

关键词： electric arc furnace ladle furnace system modeling mass balance steelmaking liquid steel

Cylinder Pressure Prediction of An HCCI Engine Using Deep Learning

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2021年第2期34卷 160-167页

作者： Halit Yaşar GültekinÇağıl Orhan Torkul MerveŞişci Department of Mechanical Engineering Engineering FacultySakarya UniversityEsentepe Campus54187 SerdivanSakaryaTurkey Department of Industrial Engineering Engineering FacultySakarya UniversityEsentepe Campus54187 SerdivanSakaryaTurkey

Engine tests are both costly and time consuming in developing a new internal combustion ***,it is of great importance to predict engine characteristics with high accuracy using artificial ***,it is possible to reduce engine testing costs and speed up the engine development *** Learning is an effective artificial intelligence method that shows high performance in many research areas through its ability to learn high-level hidden features in data *** present paper describes a method to predict the cylinder pressure of a Homogeneous Charge Compression Ignition(HCCI)engine for various excess air coefficients by using Deep Neural Network,which is one of the Deep Learning methods and is based on the artificial Neural Network(ANN).The Deep Learning results were compared with the ANN and experimental *** results show that the difference between experimental and the Deep Neural Network(DNN)results were less than 1%.The best results were obtained by Deep Learning *** cylinder pressure was predicted with a maximum accuracy of 97.83%of the experimental value by using *** the other hand,the accuracy value was increased up to 99.84%using *** results show that the DNN method can be used effectively to predict cylinder pressures of internal combustion engines.

关键词： artificial neural network Deep neural network HCCI engine Cylinder pressure Excess air coefficient

DFT Study of Catalytic Hydrogenation of 2-butyne-1,4-diol on Ni,Pd,Pt Surfaces

在线全文

学校读者我要写书评

暂无评论

DFT Study of Catalytic Hydrogenation of 2-butyne-1,4-diol on...

作者： Md Mostakim meraz 厦门大学

学位级别：硕士

1,4-丁炔二醇加氢制备1,4-丁烯二醇和1,4-丁二醇具有重要的工业价值。1,4-丁烯二醇是维生素A、维生素B6和杀虫剂的重要原料,因此1,4-丁炔二醇在医药工业中具有巨大的商业价值。1,4-丁烯二醇是1,4-丁炔二醇一步加氢的产物,容易进一步加... 详细信息

1,4-丁炔二醇加氢制备1,4-丁烯二醇和1,4-丁二醇具有重要的工业价值。1,4-丁烯二醇是维生素A、维生素B6和杀虫剂的重要原料,因此1,4-丁炔二醇在医药工业中具有巨大的商业价值。1,4-丁烯二醇是1,4-丁炔二醇一步加氢的产物,容易进一步加氢生成1,4-丁二醇,因此很难实现高选择性制备1,4-丁烯二醇。1,4-丁炔二醇加氢主要在Ni基、Pd基和Pt基催化剂上进行。目前,已有大量关于1,4-丁炔二醇加氢的实验工作报道,包括新型Ni基、Pd基和Pt基催化剂的开发。但是,对该加氢反应的DFT研究却很少,该加氢反应在分子水平上的机理,特别是参与反应的1,4-丁炔二醇分子与金属原子相互作用关系还不清楚。本研究旨在了解1,4-丁炔二醇加氢的分子机理,并比较常用的加氢催化剂,即Ni、Pd、Pt等不同金属的催化性能。利用Material Studio 8.0仿真软件包中的CASTEP模块,借助GGA函数和PBE交换相关函数,对周期系统进行了 DFT计算。本文首先研究了H2在Ni（111）、Pd（111）和Pt（111）表面四个不同位点,即顶位、桥位、hcp位和fcc位的物理/化学吸附。结果表明,H2在三种金属的1 1 1表面的物理吸附无显著性差异。H2在Pt（111）表面的桥位的化学吸附结构最稳定。H2在Ni（111）表面更容易活化分解,活化能最低。本文还研究了 1,4-丁炔二醇在Ni、Pd和Pt的111、110和100表面的吸附。结果表明1,4-丁炔二醇在Ni（111）表面吸附最稳定。吸附后,C=C键显著伸长,有利于加氢反应的发生。最后,本文研究了 1,4-丁炔二醇在Ni（111）、Pd（111）和Pt.（111）表面加氢的反应路径,搜索了反应的过度态,并计算了反应的活化能。结果表明,1,4-丁炔二醇在Pt（111）表面加氢的反应活化能最低。

关键词： 1,4-丁炔二醇加氢密度泛函理论镍钯铂

Tectonochemistry and p-t Conditions of Ramgarh and Almora Gneisses from Askot Klippe,Kumaun Lesser Himalaya

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2019年第2期93卷 322-343页

作者： Biraja P.DAS Mallickarjvm JOSHI Ashutosh KUM ar Centre of Advanced Study in Geology Institute of Science Banaras Hindu University

The chemical and petrological correlation of metamorphic nappes and klippes overlying the Proterozoic sedimentary units in the Kumaun Himalaya is still debated. The Ramgarh and Almora gneisses, not previously distinguished in the Askot Klippe, show distinct field, petrological and chemical signatures markedly similar to the tectonostratigraphic disposition of the Almora Nappe. A negative Eu anomaly in the Ramgarh granitic gneisses indicates lesser plagioclase fractionation while the Eu anomaly in the Almora pelitic gneisses is likely to have been controlled by feldspar crystallization in restites. During the anatexis at > 776°C temperature and >6.6 kbar pressure, the melt moved slightly away to its crystallization sites. The Rb/Sr ratio ?0.54 and Nb ?10 ppm is consistent with the granodioritic composition. The negative Sr anomaly in the underlying Ramgarh granitic gneisses indicates a distinct mantle derived source/plagioclase fractionation with a notable correspondence to other late orogenic granites, particularly the basement Ulleri gneisses from the Nepal Himalaya. Ramgarh gneisses plot in the late-and post-COLG field. The Askot ensemble is likely to be the tectonometamorphically reworked basement, viz. the Ramgarh Group along with its metapelitic cover o f the Almora Group, together comprising southward thrust remnants of the leading edge of the Indian Plate that collided with Tibet during the Tertiary Himalayan orogeny.

关键词： geochemistry thermobarometry Almora gneiss Ramgarh gneiss Almora Nappe Askot Klippe