期刊文献+
共找到103,130篇文章
< 1 2 250 >
每页显示 20 50 100
Hyodeoxycholic acid protects the neurovascular unit against oxygen-glucose deprivation and reoxygenation-induced injury in vitro 被引量:15
1
作者 Chang-Xiang Li Xue-Qian Wang +3 位作者 Fa-Feng Cheng Xin Yan Juan Luo Qing-Guo Wang 《Neural Regeneration Research》 SCIE CAS CSCD 2019年第11期1941-1949,共9页
Calculus bovis is commonly used for the treatment of stroke in traditional Chinese medicine. Hyodeoxycholic acid(HDCA) is a bioactive compound extracted from calculus bovis. When combined with cholic acid, baicalin an... Calculus bovis is commonly used for the treatment of stroke in traditional Chinese medicine. Hyodeoxycholic acid(HDCA) is a bioactive compound extracted from calculus bovis. When combined with cholic acid, baicalin and jas-minoidin, HDCA prevents hypoxia-reoxygenation-induced brain injury by suppressing endoplasmic reticulum stress-mediated apoptotic signaling. However, the effects of HDCA in ischemic stroke injury have not yet been studied. Neurovascular unit(NVU) dysfunction occurs in ischemic stroke. Therefore, in this study, we investigated the effects of HDCA on the NVU under ischemic conditions in vitro. We co-cultured primary brain microvascular endothelial cells, neurons and astrocytes using a transwell chamber co-culture system. The NVU was pre-treated with 10.16 or 2.54 μg/mL HDCA for 24 hours before exposure to oxygen-glucose deprivation for 1 hour. The cell counting kit-8 assay was used to detect cell activity. Flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling were used to assess apoptosis. Enzyme-linked immunosorbent assay was used to measure the expression levels of inflammatory cytokines, including interleukin-1β, interleukin-6 and tumor necrosis factor-α, and neurotrophic factors, including brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor. Oxidative stress-related factors, such as superoxide dismutase, nitric oxide, malondialdehyde and γ-glutamyltransferase, were measured using kits. Pretreatment with HDCA significantly decreased blood-brain barrier permeability and neuronal apoptosis, significantly increased transendothelial electrical resistance and γ-glutamyltransferase activity, attenuated oxidative stress damage and the release of inflammatory cytokines, and increased brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor expression. Our findings suggest that HDCA maintains NVU morphological integrity and function by modulating inflammation, oxidation stress, apoptosis, and the expression of neurotrophic factors. Therefore, HDCA may have therapeutic potential in the clinical management of ischemic stroke. This study was approved by the Ethics Committee of Experimental Animals of Beijing University of Chinese Medicine(approval No. BUCM-3-2016040201-2003) in April 2016. 展开更多
关键词 hyodeoxycholic acid oxygen glucose deprivation and REOXYGENATION blood-brain barrier permeability anti-oxidative anti-inflammatory ANTI-APOPTOTIC BRAIN-DERIVED NEUROTROPHIC FACTOR glial cell line-derived NEUROTROPHIC FACTOR ischemic stroke in vitro NEUROVASCULAR unit
下载PDF
The Analysis of Human Development Index (HDI) for Categorizing the Member States of the United Nations (UN)
2
作者 Sivarajah Mylevaganam 《Open Journal of Applied Sciences》 2017年第12期661-690,共30页
To categorize the nations to reflect the development status, to date, there are many conceptual frameworks. The Human Development index (HDI) that is published by the United Nations Development Programme is widely acc... To categorize the nations to reflect the development status, to date, there are many conceptual frameworks. The Human Development index (HDI) that is published by the United Nations Development Programme is widely accepted and practiced by many people such as academicians, politicians, and donor organizations. However, though the development of HDI has gone through many revisions since its formulation in 1990, even the current version of the index formulation published in 2016 needs research to better understand and to gap-fill the knowledge base that can enhance the index formulation to facilitate the direction of attention such as release of funds. Therefore, in this paper, based on principal component analysis and K-means clustering algorithm, the data that reflect the measures of life expectancy index (LEI), education index (EI), and income index (II) are analyzed to categorize and to rank the member states of the UN using R statistical software package, an open source extensible programming language for statistical computing and graphics. The outcome of the study shows that the proportion of total eigen value (i.e., proportion of total variance) explained by PCA-1 (i.e., first principal component) accounts for more than 85% of the total variation. Moreover, the proportion of total eigen value explained by PCA-1 increases with time (i.e., yearly) though the amount of increase with time is not significant. However, the proportions of total eigen value explained by PCA-2 and PCA-3 decrease with time. Therefore, the loss of information in choosing PCA-1 to represent the chosen explanatory variables (i.e., LEI, EI, and II) may diminish with time if the trend of increasing pattern of proportion of total eigen value explained by PCA-1 with time continues in the future as well. On the other hand, the correlation between EI and PCA-1 increases with time although the magnitude of increase is not that significant. This same trend is observed in II as well. However, in contrast to these observations, the correlation between PCA-1 and LEI decreases with time. These findings imply that the contributions of EI and II to PCA-1 increase with time, but the contribution of LEI to PCA-1 decreases with time. On top of these, as per Hopkins statistic, the clusterability of the information conveyed by PCA-1 alone is far better than the clusterability of the information conveyed by PCA scores (i.e., PCA-1, PCA-2, and PCA-3) and the explanatory variables. Therefore, choosing PCA-1 to represent the chosen explanatory variables is becoming more concrete. 展开更多
关键词 Human DEVELOPMENT Index Economy Sustainability unitED Nations DEVELOPMENT Programme Education Life EXPECTANCY Per Capita INCOME JavaScript R Statistical Software Principal Component ANALYSIS K-Means Clustering HOPKINS Statistic
下载PDF
Thermodynamic Simulation of CCP in Air-Cooled Heat Pump Unit with HFCs and CO<sub>2</sub>Trans-Critical 被引量:2
3
作者 Feihu Chen Shuguang Liao Guangcai Gong 《Journal of Power and Energy Engineering》 2018年第9期141-164,共24页
The exergy analysis and finite time thermodynamic methods had been employed to analyze the compound condensation process (CCP). It was based on the air-cooling heat pump unit. The cooling capacity of the chiller unit ... The exergy analysis and finite time thermodynamic methods had been employed to analyze the compound condensation process (CCP). It was based on the air-cooling heat pump unit. The cooling capacity of the chiller unit is about 1 kW, and the work refrigerant is R22/R407C/R410A/CO2. The MATLAB/SIMULINK software was employed to build the simulation model. The thermodynamic simulation model is significant for the optimization of parameters of the unit, such as condensation and evaporation temperature and mass flow of the sanitary hot water and size of hot water storage tank. The COP of the CCP of R410A system is about 3% - 5% higher than the CCP of the R22 system, while CCP of the R407C system is a little lower than the CCP of R22 system. And the CCP of CO2 trans-critical system has advantage in the hot supply mode. The simulation method provided a theoretical reference for developing the production of CCP with substitute refrigerant R407C/R410A/CO2. 展开更多
关键词 Air-Cooled Heat Pump unit Compound Condensation Process (CCP) Exergy Analysis Method Sanitary Hot Water MATLAB/SIMULINK Software Fluorine SUBSTITUTE REFRIGERANT R407C/R410A Natural REFRIGERANT CO2
下载PDF
Multitarget stool DNA for colorectal cancer screening:A review and commentary on the United States Preventive Services Draft Guidelines 被引量:3
4
作者 Barry M Berger Bernard Levin Robert J Hilsden 《World Journal of Gastrointestinal Oncology》 SCIE CAS 2016年第5期450-458,共9页
Multitarget stool DNA(mt-sDNA) testing was approved for average risk colorectal cancer(CRC) screening by the United States Food and Drug Administration and thereafter reimbursed for use by the Medicare program(2014).T... Multitarget stool DNA(mt-sDNA) testing was approved for average risk colorectal cancer(CRC) screening by the United States Food and Drug Administration and thereafter reimbursed for use by the Medicare program(2014).The United States Preventive Services Task Force(USPSTF) October 2015 draft recommendation for CRC screening included mt-s DNA as an "alternative" screening test that "may be useful in select clinical circumstances",despite its very high sensitivity for early stage CRC.The evidence supporting mt-s DNA for routine screening use is robust.The clinical efficacy of mt-s DNA as measured by sensitivity,specificity,life-years gained(LYG),and CRC deaths averted is similar to or exceeds that of the other more specifically recommended screening options included in the draft document,especially those requiring annual testing adherence.In a population with primarily irregular screening participation,tests with the highest point sensitivity and reasonable specificity are more likely to favorably impact CRC related morbidity and mortality than those depending on annual adherence.This paper reviews the evidence supporting mt-s DNA for routine screening and demonstrates,using USPSTF's modeling data,that mt-s DNA at three-year intervals provides significant clinical net benefits and fewer complications per LYG than annual fecal immunochemical testing,high sensitivity guaiac based fecal occult blood testing and 10-year colonoscopy screening. 展开更多
关键词 Colorectal CANCER screening Multitarget STOOL DNA STOOL DNA The united States Preventive Services Task Force CANCER Intervention Surveillance MODELING Network FECAL immunological technique MODELING Interval
下载PDF
Electronic Band Structure of Graphene Based on the Rectangular 4-Atom Unit Cell
5
作者 Akira Suzuki Masashi Tanabe Shigeji Fujita 《Journal of Modern Physics》 2017年第4期607-621,共15页
The Wigner-Seitz unit cell (rhombus) for a honeycomb lattice fails to establish a k-vector in the 2D space, which is required for the Bloch electron dynamics. Phonon motion cannot be discussed in the triangular coordi... The Wigner-Seitz unit cell (rhombus) for a honeycomb lattice fails to establish a k-vector in the 2D space, which is required for the Bloch electron dynamics. Phonon motion cannot be discussed in the triangular coordinates, either. In this paper, we propose a rectangular 4-atom unit cell model, which allows us to discuss the electron and phonon (wave packets) motion in the k-space. The present paper discusses the band structure of graphene based on the rectangular 4-atom unit cell model to establish an appropriate k-vector for the Bloch electron dynamics. To obtain the band energy of a Bloch electron in graphene, we extend the tight-binding calculations for the Wigner-Seitz (2-atom unit cell) model of Reich et al. (Physical Review B, 66, Article ID: 035412 (2002)) to the rectangular 4-atom unit cell model. It is shown that the graphene band structure based on the rectangular 4-atom unit cell model reveals the same band structure of the graphene based on the Wigner-Seitz 2-atom unit cell model;the &pi;-band energy holds a linear dispersion (&epsilon;&minus;k ) relations near the Fermi energy (crossing points of the valence and the conduction bands) in the first Brillouin zone of the rectangular reciprocal lattice. We then confirm the suitability of the proposed rectangular (orthogonal) unit cell model for graphene in order to establish a 2D k-vector responsible for the Bloch electron (wave packet) dynamics in graphene. 展开更多
关键词 GRAPHENE RECTANGULAR 4-Atom unit Cell Model PRIMITIVE Orthogonal Basis VECTOR BLOCH Electron (Wave Packet) Dynamics k-Vector Dirac Points Linear Dispersion Relation
下载PDF
Prevention of stress-related ulcer bleeding at the intensive care unit: Risks and benefits of stress ulcer prophylaxis 被引量:24
6
作者 Lukas Buendgens Alexander Koch Frank Tacke 《World Journal of Critical Care Medicine》 2016年第1期57-64,共8页
Stress-related mucosal disease is a typical complication of critically ill patients in the intensive care unit(ICU). It poses a risk of clinically relevant upper gastrointestinal(GI) bleeding. Therefore, stress ulcer ... Stress-related mucosal disease is a typical complication of critically ill patients in the intensive care unit(ICU). It poses a risk of clinically relevant upper gastrointestinal(GI) bleeding. Therefore, stress ulcer prophylaxis(SUP)is recommended in high-risk patients, especially those mechanically ventilated > 48 h and those with a manifest coagulopathy. Proton pump inhibitors(PPI) and, less effectively, histamine 2 receptor antagonists(H2RA) prevent GI bleeding in critically ill patients in the ICU. However, the routine use of pharmacological SUP does not reduce overall mortality in ICU patients. Moreover, recent studies revealed that SUP in the ICU might be associated with potential harm such as an increased risk of infectious complications, especially nosocomial pneumonia and Clostridium difficile-associated diarrhea. Additionally, special populations such as patients with liver cirrhosis may even have an increased mortality rate if treated with PPI. Likewise, PPI can be toxic for both the liver and the bone marrow, and some PPI show clinically relevant interactions with important other drugs like clopidogrel. Therefore, the agent of choice, the specific balance of risks and benefits for individual patients as well as the possible dose of PPI has to be chosen carefully. Alternatives to PPI prophylaxis include H2 RA and/or sucralfate. Instead of routine SUP, further trials should investigate risk-adjusted algorithms, balancing benefits and threats of SUP medication in the ICU. 展开更多
关键词 Proton pump inhibitors CLOSTRIDIUM DIFFICILE Intensive care unit Gastrointestinal HEMORRHAGE Stress HISTAMINE H2 ANTAGONISTS Risk assessment Pneumonia Physiological Sucralfate
下载PDF
Structural and functional damage to the hippocampal neurovascular unit in diabetes-related depression 被引量:25
7
作者 Jian Liu Yu-Hong Wang +4 位作者 Wei Li Lin Liu Hui Yang Pan Meng Yuan-Shan Han 《Neural Regeneration Research》 SCIE CAS CSCD 2019年第2期289-297,共9页
Previous studies have shown that models of depression exhibit structural and functional changes to the neurovascular unit. Thus, we hypothesized that diabetes-related depression might be associated with damage to the ... Previous studies have shown that models of depression exhibit structural and functional changes to the neurovascular unit. Thus, we hypothesized that diabetes-related depression might be associated with damage to the hippocampal neurovascular unit. To test this hypothesis, neurons, astrocytes and endothelial cells were isolated from the brain tissues of rat embryos and newborn rats. Hippocampal neurovascular unit co-cultures were produced using the Transwell chamber co-culture system. A model of diabetes-related depression was generated by adding 150 mM glucose and 200 μM corticosterone to the culture system and compared with the neuron + astrocyte and astrocyte + endothelial cell co-culture systems. Western blot assay was used to measure levels of structural proteins in the hippocampal neurovascular unit co-culture system. Levels of basic fibroblast growth factor, angiogenic factor 1, glial cell line–derived neurotrophic factor, transforming growth factor β1, leukemia inhibitory factor and 5-hydroxytryptamine in the hippocampal neurovascular unit co-culture system were measured by enzyme-linked immunosorbent assay. Flow cytometry and terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick end labeling staining was used to assess neuronal apoptosis in the hippocampal neurovascular unit. The neurovascular unit triple cell co-culture system had better barrier function and higher levels of structural and secretory proteins than the double cell co-culture systems. In comparison, in the model of diabetes-related depression, the neurovascular unit was damaged with decreased barrier function, poor structural integrity and impaired secretory function. Moreover, neuronal apoptosis was markedly increased, and 5-hydroxytryptamine levels were reduced. These results suggest that diabetes-related depression is associated with structural and functional damage to the neurovascular unit. Our findings provide a foundation for further studies on the pathogenesis of diabetes-related depression. 展开更多
关键词 nerve REGENERATION hippocampus neurovascular unit neurons astrocytes brain microvascular cells cell culture co-culture diabetes-related DEPRESSION hyperglycemia corticosterone neural REGENERATION
下载PDF
Uncertainties of landslide susceptibility prediction:influences of different study area scales and mapping unit scales
8
作者 Faming Huang Yu Cao +4 位作者 Wenbin Li Filippo Catani Guquan Song Jinsong Huang Changshi Yu 《International Journal of Coal Science & Technology》 EI CAS CSCD 2024年第2期143-172,共30页
This study aims to investigate the effects of different mapping unit scales and study area scales on the uncertainty rules of landslide susceptibility prediction(LSP).To illustrate various study area scales,Ganzhou Ci... This study aims to investigate the effects of different mapping unit scales and study area scales on the uncertainty rules of landslide susceptibility prediction(LSP).To illustrate various study area scales,Ganzhou City in China,its eastern region(Ganzhou East),and Ruijin County in Ganzhou East were chosen.Different mapping unit scales are represented by grid units with spatial resolution of 30 and 60 m,as well as slope units that were extracted by multi-scale segmentation method.The 3855 landslide locations and 21 typical environmental factors in Ganzhou City are first determined to create spatial datasets with input-outputs.Then,landslide susceptibility maps(LSMs)of Ganzhou City,Ganzhou East and Ruijin County are pro-duced using a support vector machine(SVM)and random forest(RF),respectively.The LSMs of the above three regions are then extracted by mask from the LSM of Ganzhou City,along with the LSMs of Ruijin County from Ganzhou East.Additionally,LSMs of Ruijin at various mapping unit scales are generated in accordance.Accuracy and landslide suscepti-bility indexes(LSIs)distribution are used to express LSP uncertainties.The LSP uncertainties under grid units significantly decrease as study area scales decrease from Ganzhou City,Ganzhou East to Ruijin County,whereas those under slope units are less affected by study area scales.Of course,attentions should also be paid to the broader representativeness of large study areas.The LSP accuracy of slope units increases by about 6%–10%compared with those under grid units with 30 m and 60 m resolution in the same study area's scale.The significance of environmental factors exhibits an averaging trend as study area scale increases from small to large.The importance of environmental factors varies greatly with the 60 m grid unit,but it tends to be consistent to some extent in the 30 m grid unit and the slope unit. 展开更多
关键词 Landslide susceptibility prediction Uncertainty analysis Study areas scales Mapping unit scales Slope units Random forest
下载PDF
Geologic characteristics,exploration and production progress of shale oil and gas in the United States:An overview
9
作者 MCMAHON T P LARSON T E +1 位作者 ZHANG T SHUSTER M 《Petroleum Exploration and Development》 SCIE 2024年第4期925-948,共24页
We present a systematic summary of the geological characteristics,exploration and development history and current state of shale oil and gas in the United States.The hydrocarbon-rich shales in the major shale basins o... We present a systematic summary of the geological characteristics,exploration and development history and current state of shale oil and gas in the United States.The hydrocarbon-rich shales in the major shale basins of the United States are mainly developed in six geological periods:Middle Ordovician,Middle-Late Devonian,Early Carboniferous(Middle-Late Mississippi),Early Permian,Late Jurassic,and Late Cretaceous(Cenomanian-Turonian).Depositional environments for these shales include intra-cratonic basins,foreland basins,and passive continental margins.Paleozoic hydrocarbon-rich shales are mainly developed in six basins,including the Appalachian Basin(Utica and Marcellus shales),Anadarko Basin(Woodford Shale),Williston Basin(Bakken Shale),Arkoma Basin(Fayetteville Shale),Fort Worth Basin(Barnett Shale),and the Wolfcamp and Leonardian Spraberry/Bone Springs shale plays of the Permian Basin.The Mesozoic hydrocarbon-rich shales are mainly developed on the margins of the Gulf of Mexico Basin(Haynesville and Eagle Ford)or in various Rocky Mountain basins(Niobrara Formation,mainly in the Denver and Powder River basins).The detailed analysis of shale plays reveals that the shales are different in facies and mineral components,and"shale reservoirs"are often not shale at all.The United States is abundant in shale oil and gas,with the in-place resources exceeding 0.246×10^(12)t and 290×10^(12)m^(3),respectively.Before the emergence of horizontal well hydraulic fracturing technology to kick off the"shale revolution",the United States had experienced two decades of exploration and production practices,as well as theory and technology development.In 2007-2023,shale oil and gas production in the United States increased from approximately 11.2×10^(4)tons of oil equivalent per day(toe/d)to over 300.0×10^(4)toe/d.In 2017,the shale oil and gas production exceeded the conventional oil and gas production in the country.In 2023,the contribution from shale plays to the total U.S.oil and gas production remained above 60%.The development of shale oil and gas has largely been driven by improvements in drilling and completion technologies,with much of the recent effort focused on“cube development”or“co-development”.Other efforts to improve productivity and efficiency include refracturing,enhanced oil recovery,and drilling of“U-shaped”wells.Given the significant resources base and continued technological improvements,shale oil and gas production will continue to contribute significant volumes to total U.S.hydrocarbon production. 展开更多
关键词 united States shale oil shale gas shale reservoirs unconventional reservoirs oil and gas production resource assessment
下载PDF
Effects of nursing team communication and collaboration on treatment outcomes in intensive care unit patients with severe pneumonia
10
作者 Xi-Fang Wei Ting Zhu Qiao Xia 《World Journal of Clinical Cases》 SCIE 2024年第20期4166-4173,共8页
BACKGROUND Severe pneumonia is a common severe respiratory infection worldwide,and its treatment is challenging,especially for patients in the intensive care unit(ICU).AIM To explore the effect of communication and co... BACKGROUND Severe pneumonia is a common severe respiratory infection worldwide,and its treatment is challenging,especially for patients in the intensive care unit(ICU).AIM To explore the effect of communication and collaboration between nursing teams on the treatment outcomes of patients with severe pneumonia in ICU.METHODS We retrospectively analyzed 60 patients with severe pneumonia who were treated at the ICU of the hospital between January 1,2021 and December 31,2023.We compared and analyzed the respiratory mechanical indexes[airway resistance(Raw),mean airway pressure(mPaw),peak pressure(PIP)],blood gas analysis indexes(arterial oxygen saturation,arterial oxygen partial pressure,and oxygenation index),and serum inflammatory factor levels[C-reactive protein(CRP),procalcitonin(PCT),cortisol(COR),and high mobility group protein B1(HMGB1)]of all patients before and after treatment.RESULTS Before treatment,there was no significant difference in respiratory mechanics index and blood gas analysis index between 2 groups(P>0.05).However,after treatment,the respiratory mechanical indexes of patients in both groups were significantly improved,and the improvement of Raw,mPaw,plateau pressure,PIP and other indexes in the combined group after communication and collaboration with the nursing team was significantly better than that in the single care group(P<0.05).The serum CRP and PCT levels of patients were significantly decreased,and the difference was statistically significant compared with that of nursing group alone(P<0.05).The levels of serum COR and HMGB1 before and after treatment were also significantly decreased between the two groups.CONCLUSION The communication and collaboration of the nursing team have a significant positive impact on respiratory mechanics indicators,blood gas analysis indicators and serum inflammatory factor levels in the treatment of severe pneumonia patients in ICU. 展开更多
关键词 Intensive care unit Severe pneumonia Nursing team Communication and collaboration Respiratory mechanics indicators Blood gas analysis indicators Serum inflammatory factors
下载PDF
Development unit division and favorable area evaluation for joint mining coalbed methane 被引量:3
11
作者 YANG Zhaobiao LI Yangyang +6 位作者 QIN Yong SUN Hansen ZHANG Ping ZHANG Zhengguang WU Congcong LI Cunlei CHEN Changxiao 《Petroleum Exploration and Development》 2019年第3期583-593,共11页
Based on the productivity equation of coalbed methane (CBM) well, considering the impact of coal reservoir reformability on gas well productivity, the main production layer optimization index in the “three-step metho... Based on the productivity equation of coalbed methane (CBM) well, considering the impact of coal reservoir reformability on gas well productivity, the main production layer optimization index in the “three-step method” of optimal combination of production layers is corrected, and then the CBM production layer potential index is introduced to evaluate favorable areas for commingled multi-coal seam production. Through analysis of the key parameters of coal reservoirs affecting the CBM productivity index, a development unit division method for areas with multi-coal seams is established, and a quantitative grading index system is proposed. On this basis, the evaluation process of CBM development favorable area is developed: the mature 3-D modeling technology is used to characterize the reservoir physical properties of multi-coal seams in full-scale;the production layer potential index of each grid is calculated, and the production layer potential index contour under single-layer or commingled multi-layer production are plotted;according to the distribution of the contour of production layer potential index, the quantitative index of CBM development unit is adopted to outline the grade I, II, III coal reservoir distribution areas, and thus to pick out the favorable development areas. The practical application in the Yuwang block of Laochang in Yunnan proved that the favorable area evaluation process proposed can effectively overcome the defects of selecting favorable development areas only relying on evaluation results of a major coal seam pay, and enhance the accuracy of the evaluation results, meeting the requirements of selecting favorable areas for multi-coal seam commingled CBM production. 展开更多
关键词 coalbed methane reservoir physical property JOINT MINING production layer potential INDEX DEVELOPMENT unit DIVISION quantitative INDEX favorable area EVALUATION
下载PDF
Hierarchy of mesenchymal stem cells: Comparison of multipotentmesenchymal stromal cells with fibroblast colony forming units 被引量:2
12
作者 Irina N. Shipounova Natalia A. Petinati +5 位作者 Alexey E. Bigildeev Natalia V. Sats Nina J. Drize Larisa A. Kuzmina Elena N. Parovichnikova Valery G. Savchenko 《Journal of Biomedical Science and Engineering》 2013年第8期66-73,共8页
The organization of the compartment of mesenchymal stem cells is still obscure. Two types of human stromal precursor cells are known. Both of them are analyzed in in vitro system: mesenchymal multipotent stromal cells... The organization of the compartment of mesenchymal stem cells is still obscure. Two types of human stromal precursor cells are known. Both of them are analyzed in in vitro system: mesenchymal multipotent stromal cells (MMSC) and fibroblast colony forming units (CFU-F). The aim of this study was to compare the main characteristics of MMSC and CFU-F derived from the bone marrow of 24 healthy donors. Growth and differentiation parameters, as well as relative expression levels of different genes were analyzed in MMSC and CFU-F. MMSC were cultivated for 5 passages. CFU-F concentration was determined for each bone marrow sample. The data obtained demonstrated the heterogeneity and hierarchical organization of both studied populations of stromal precursor cells-MMSC and CFU-F. These two types of stromal precursor cells turned to be different in most parameters studied. Altogether MMSC seemed to be more immature cells than CFU-F and took up the higher position in hierarchical tree of mesenchymal stem cells. The rate of differentiation and proliferative potential decreased with the donor’s age in both populations MMSC and CFU-F. 展开更多
关键词 Mesenchymal MULTIPOTENT Stromal Cells (MMSC) FIBROBLAST COLONY FORMING unitS (CFU-F) Real-Time Polymerase Chain Reaction Gene Expression Level Aging
下载PDF
Optic nerve sheath diameters in nontraumatic brain injury:A scoping review and role in the intensive care unit
13
作者 Madhura Bhide Deven Juneja +1 位作者 Omender Singh Shakya Mohanty 《World Journal of Critical Care Medicine》 2024年第3期75-90,共16页
BACKGROUND Neuromonitoring in medical intensive care units is challenging as most patients are unfit for invasive intracranial pressure(ICP)modalities or unstable to transport for imaging.Ultrasonography-based optic n... BACKGROUND Neuromonitoring in medical intensive care units is challenging as most patients are unfit for invasive intracranial pressure(ICP)modalities or unstable to transport for imaging.Ultrasonography-based optic nerve sheath diameter(ONSD)is an attractive option as it is reliable,repeatable and easily performed at the bedside.It has been sufficiently validated in traumatic brain injury(TBI)to be incorporated into the guidelines.However,currently the data for non-TBI patients is inconsistent for a scientific recommendation to be made.AIM To compile the existing evidence for understanding the scope of ONSD in measuring ICP in adult non-traumatic neuro-critical patients.METHODS PubMed,Google Scholar and research citation analysis databases were searched for studies in adult patients with non-traumatic causes of raised ICP.Studies from 2010 to 2024 in English languages were included.RESULTS We found 37 articles relevant to our search.The cutoff for ONSD in predicting ICP varied from 4.1 to 6.3 mm.Most of the articles used cerebrospinal fluid opening pressure followed by raised ICP on computed tomography/magnetic resonance imaging as the comparator parameter.ONSD was also found to be a reliable outcome measure in cases of acute ischaemic stroke,intracerebral bleeding and intracranial infection.However,ONSD is of doubtful utility in septic metabolic encephalopathy,dysnatremias and aneurysmal subarachnoid haemorrhage.CONCLUSION ONSD is a useful tool for the diagnosis of raised ICP in non-traumatic neuro-critically ill patients and may also have a role in the prognostication of a subset of patients. 展开更多
关键词 Intracranial hypertension Intracranial pressure monitoring Medical intensive care unit Neuro-monitoring Nontraumatic brain injury Optic nerve sheath diameter Optic nerve ultrasound
下载PDF
Temperature Trends and Accumulation of Chill Hours, Chill Units, and Chill Portions in South Carolina
14
作者 José O. Payero 《Atmospheric and Climate Sciences》 2024年第2期173-190,共18页
There is considerable concern about the potential impact of climate change on agriculture, such as the accumulation of chilling hours needed to break the dormancy of many perennial plants, like fruit trees. Therefore,... There is considerable concern about the potential impact of climate change on agriculture, such as the accumulation of chilling hours needed to break the dormancy of many perennial plants, like fruit trees. Therefore, this study aimed to determine if there had been a significant change in air temperatures and chill hours, chill units, and chill portion accumulation in South Carolina over the last two decades. Two decades of daily maximum (T<sub>max</sub>) and minimum (T<sub>min</sub>) air temperature records were obtained from weather stations in thirty-one counties in South Carolina. Hourly temperature data, reconstructed from the daily data, were used to calculate the daily and annual chill hours, chill units, and chill portions accumulation using four different chill models for each location and year. The chill models included the T(t) °C model, the 0°C °C model, the Utah model, and the Dynamic model. For each county, regression analyses were conducted to evaluate the historical trends. Despite year-to-year variability, the tendency was a statistically significant (α = 0.05) increase in air temperature, averaging 0.089°C per year for 20 out of 31 counties in South Carolina. The other 11 counties had no significant change in temperature. The average temperature increase in the 31 counties was 0.072°C per year. The temperature increase resulted in a decrease in annual chill accumulation during the fall to spring, averaging 17.7 chill hours, 8.6 chill hours, 17.0 chill units, and 0.40 chill portions per year calculated with the T(t) °C, 0°C °C, Utah, and Dynamic models, respectively. However, whether this decrease in chill values was statistically significant or not depended on the chill model used. This study did not investigate the cause of the observed historical trends in temperature and chill accumulation. Still, if the trends continue, they could significantly impact the future of the temperate fruit tree industry in the state. 展开更多
关键词 Chill Hours Chill units Chill Portions TEMPERATURE Fruit Trees Climate Change DORMANCY
下载PDF
Assessment of Wet Season Precipitation in the Central United States by the Regional Climate Simulation of the WRFG Member in NARCCAP and Its Relationship with Large-Scale Circulation Biases 被引量:1
15
作者 Yating ZHAO Ming XUE +2 位作者 Jing JIANG Xiao-Ming HU Anning HUANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第4期619-638,共20页
Assessment of past-climate simulations of regional climate models(RCMs)is important for understanding the reliability of RCMs when used to project future regional climate.Here,we assess the performance and discuss pos... Assessment of past-climate simulations of regional climate models(RCMs)is important for understanding the reliability of RCMs when used to project future regional climate.Here,we assess the performance and discuss possible causes of biases in a WRF-based RCM with a grid spacing of 50 km,named WRFG,from the North American Regional Climate Change Assessment Program(NARCCAP)in simulating wet season precipitation over the Central United States for a period when observational data are available.The RCM reproduces key features of the precipitation distribution characteristics during late spring to early summer,although it tends to underestimate the magnitude of precipitation.This dry bias is partially due to the model’s lack of skill in simulating nocturnal precipitation related to the lack of eastward propagating convective systems in the simulation.Inaccuracy in reproducing large-scale circulation and environmental conditions is another contributing factor.The too weak simulated pressure gradient between the Rocky Mountains and the Gulf of Mexico results in weaker southerly winds in between,leading to a reduction of warm moist air transport from the Gulf to the Central Great Plains.The simulated low-level horizontal convergence fields are less favorable for upward motion than in the NARR and hence,for the development of moist convection as well.Therefore,a careful examination of an RCM’s deficiencies and the identification of the source of errors are important when using the RCM to project precipitation changes in future climate scenarios. 展开更多
关键词 NARCCAP Central united States PRECIPITATION low-level jet large-scale environment diurnal variation
下载PDF
A gated recurrent unit model to predict Poisson’s ratio using deep learning 被引量:1
16
作者 Fahd Saeed Alakbari Mysara Eissa Mohyaldinn +4 位作者 Mohammed Abdalla Ayoub Ibnelwaleed A.Hussein Ali Samer Muhsan Syahrir Ridha Abdullah Abduljabbar Salih 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第1期123-135,共13页
Static Poisson’s ratio(vs)is crucial for determining geomechanical properties in petroleum applications,namely sand production.Some models have been used to predict vs;however,the published models were limited to spe... Static Poisson’s ratio(vs)is crucial for determining geomechanical properties in petroleum applications,namely sand production.Some models have been used to predict vs;however,the published models were limited to specific data ranges with an average absolute percentage relative error(AAPRE)of more than 10%.The published gated recurrent unit(GRU)models do not consider trend analysis to show physical behaviors.In this study,we aim to develop a GRU model using trend analysis and three inputs for predicting n s based on a broad range of data,n s(value of 0.1627-0.4492),bulk formation density(RHOB)(0.315-2.994 g/mL),compressional time(DTc)(44.43-186.9 μs/ft),and shear time(DTs)(72.9-341.2μ s/ft).The GRU model was evaluated using different approaches,including statistical error an-alyses.The GRU model showed the proper trends,and the model data ranges were wider than previous ones.The GRU model has the largest correlation coefficient(R)of 0.967 and the lowest AAPRE,average percent relative error(APRE),root mean square error(RMSE),and standard deviation(SD)of 3.228%,1.054%,4.389,and 0.013,respectively,compared to other models.The GRU model has a high accuracy for the different datasets:training,validation,testing,and the whole datasets with R and AAPRE values were 0.981 and 2.601%,0.966 and 3.274%,0.967 and 3.228%,and 0.977 and 2.861%,respectively.The group error analyses of all inputs show that the GRU model has less than 5% AAPRE for all input ranges,which is superior to other models that have different AAPRE values of more than 10% at various ranges of inputs. 展开更多
关键词 Static Poissons ratio Deep learning Gated recurrent unit(GRU) Sand control Trend analysis Geomechanical properties
下载PDF
Antibiotic sensitivity pattern of bacterial pathogens in the intensive care unit of Fatmawati Hospital,Indonesia 被引量:7
17
作者 Maksum Radji Siti Fauziah Nurgani Aribinuko 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2011年第1期39-42,共4页
Objective:To evaluate the sensitivity pattern of bacterial pathogens in the intensive care unit(ICU) of a tertiary care of Falmawati Hospital Jakarta Indonesia.Methods:A cross sectional retrospective study of bacteria... Objective:To evaluate the sensitivity pattern of bacterial pathogens in the intensive care unit(ICU) of a tertiary care of Falmawati Hospital Jakarta Indonesia.Methods:A cross sectional retrospective study of bacterial pathogen was carried out on a total of 722 patients that were admitted to the ICU of Fatmawati Hospital Jakarta Indonesia during January 2009 to March 2010. All bacteria were identified by standard microbiologic methods,and(heir antibiotic susceptibility testing was performed using disk diffusion method.Results:Specimens were collected from 385 patients who were given antimicrobial treatment,of which 249(64.68%) were cultured positive and 136(35.32%) were negative.The most predominant isolate was Pseudomonas aeruginosa(P.aeruginosa)(26.5%) followed by Klebsiella pneumoniae(K.pneumoniae)(15.3%) and Staphylococcus epidermidis(14.9%).P.aeruginosa isolates showed high rate of resistance to cephalexin(95.3%),cefotaxime(64.1%),and ceftriaxone(60.9%).Amikacin was the most effective(84.4%) antibiotic against P.aeruginosa followed by imipenem(81.2%),and meropenem(75.0%).K.pneumoniae showed resistance to cephalexin(86.5%),ceftriaxone(75.7%),ceftazidime(73.0%),cefpirome(73.0%) and cefotaxime(67.9%),respectively.Conclusions:Most bacteria isolated from ICU of Fatmawati Hospital Jakarta Indonesia were resistant to the third generation of cephalosporins,and quinolone antibiotics.Regular surveillance of antibiotic susceptibility pallerns is very important for setting orders to guide the clinician in choosing empirical or directed therapy of infected patients. 展开更多
关键词 Antibiotic susceptibility Intensive care unit BACTERIAL RESISTANCE BACTERIAL pathogen Sensitivity PATTERN Antimicrobial RESISTANCE Pseudomonas AERUGINOSA KLEBSIELLA PNEUMONIAE Isolate Specimen
下载PDF
The 2 ℃ Global Temperature Target and the Evolution of the Long-TermGoal of Addressing Climate Change-From the United Nations FrameworkConvention on Climate Change to the Paris Agreement 被引量:21
18
作者 Yun Gao Xiang Gao Xiaohua Zhang 《Engineering》 SCIE EI 2017年第2期272-278,共7页
The Paris Agreement proposed to keep the increase in global average temperature to well below 2 ℃ abovepre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 ℃ above pre-industriallevel... The Paris Agreement proposed to keep the increase in global average temperature to well below 2 ℃ abovepre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 ℃ above pre-industriallevels. It was thus the first international treaty to endow the 2 ℃ global temperature target with legal effect.The qualitative expression of the ultimate objective in Article 2 of the United Nations Framework Conventionon Climate Change (UNFCCC) has now evolved into the numerical temperature rise target in Article 2 of theParis Agreement. Starting with the Second Assessment Report (SAR) of the Intergovernmental Panel on Cli-mate Change (IPCC), an important task for subsequent assessments has been to provide scientific informa-tion to help determine the quantified long-term goal for UNFCCC negotiation. However, due to involvementin the value judgment within the scope of non-scientific assessment, the IPCC has never scientifically af-firmed the unacceptable extent of global temperature rise. The setting of the long-term goal for addressingclimate change has been a long process, and the 2 ℃ global temperature target is the political consensuson the basis of scientific assessment. This article analyzes the evolution of the long-term global goal foraddressing climate change and its impact on scientific assessment, negotiation processes, and global low-carbon development, from aspects of the origin of the target, the series of assessments carried out by the 1PCCfocusing on Article 2 of the UNFCCC, and the promotion of the global temperature goal at the political level. 展开更多
关键词 CLIMATE CHANGE International negotiationln tergovernmental Panel on CLIMATE CHANGE unitED Nations Framework CONVENTION on CLIMATE ChangeLong-term GOAL Critical vulnerability Intuitive building
下载PDF
Unit 5 What are the shirts made of? Section A 3a-3c教学设计(一)
19
作者 孙艺凝 《黑龙江教育(中学版)》 2019年第3期6-8,共3页
(此课选自义务教育课程标准实验教科书《英语》(新目标)Go for it.九年级(全一册))一、设计理念:本节课的教学内容是一节完整的阅读板块,采用单词讲解,读前预测,读中利用寻读和细读的阅读策略提取文章关键信息,读后利用思维导图总结全... (此课选自义务教育课程标准实验教科书《英语》(新目标)Go for it.九年级(全一册))一、设计理念:本节课的教学内容是一节完整的阅读板块,采用单词讲解,读前预测,读中利用寻读和细读的阅读策略提取文章关键信息,读后利用思维导图总结全文信息,然后讲解文章难句的设计思路,培养学生的分析能力和阅读技能。 展开更多
关键词 SECTION A 3a-3c unit 5 WHAT ARE the SHIRTS MADE of
下载PDF
Analysis of the Erosion-Corrosion Mechanism of the Air Cooler in a Hydrocracking Unit:A Numerical and Experimental Study
20
作者 Su Guoqing Li Yan +1 位作者 Guo Hongli Zhang Jianwen 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2024年第1期126-138,共13页
Corrosion leakages often occur in the air cooler of a hydrocracking unit,with the failure sites mainly located in the entrance area of the tubes.An analysis of the macroscopic morphology and corrosion products confirm... Corrosion leakages often occur in the air cooler of a hydrocracking unit,with the failure sites mainly located in the entrance area of the tubes.An analysis of the macroscopic morphology and corrosion products confirmed that the damage was caused by erosion-corrosion(E-C).Numerical and experimental methods were applied to investigate the E-C mechanism in the air cooler.Computational fluid dynamics(CFD)was used to calculate the hydrodynamic parameters of the air cooler.The results showed that there was a biased flow in the air cooler,which led to a significant increase in velocity,turbulent kinetic energy and wall shear within 0.2 m of the tube entrance.A visualization experiment was then performed to determine the principles of migration and transformation of multiphase flow in the air cooler tubes.Various flow patterns(pure droplet flow,mist flow,and annular flow)and their evolutionary processes were clearly depicted experimentally.The initiation mechanism and processes leading to the development of E-C in the air cooler were also determined.This study provided a comprehensive explanation for the E-C failures that occur in air coolers during operation. 展开更多
关键词 air cooler hydrocracking unit EROSION-CORROSION SIMULATION visualization experiment multiphase flow
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部