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排序方式: 共有802条查询结果,搜索用时 62 毫秒
1.
Bilal Alashkar Alhamwe Daniel P. Potaczek Sarah Miethe Fahd Alhamdan Lukas Hintz Arslan Magomedov Holger Garn 《International journal of molecular sciences》2021,22(9)
Extracellular vesicles (EVs) are membranous structures, which are secreted by almost every cell type analyzed so far. In addition to their importance for cell-cell communication under physiological conditions, EVs are also released during pathogenesis and mechanistically contribute to this process. Here we summarize their functional relevance in asthma, one of the most common chronic non-communicable diseases. Asthma is a complex persistent inflammatory disorder of the airways characterized by reversible airflow obstruction and, from a long-term perspective, airway remodeling. Overall, mechanistic studies summarized here indicate the importance of different subtypes of EVs and their variable cargoes in the functioning of the pathways underlying asthma, and show some interesting potential for the development of future therapeutic interventions. Association studies in turn demonstrate a good diagnostic potential of EVs in asthma. 相似文献
2.
Waheed Iqbal Mariam Batool Arslan Hameed Saghir Abbas Muhammad Arif Nadeem 《International Journal of Hydrogen Energy》2021,46(49):25050-25059
Transition metal oxyhydroxides have been used as promising electrocatalysts for water splitting however, their catalytic activity is restricted due to low surface area and poor conductivity. Herein, we report novel composite FeOOH@ZIF-12/graphene composite as electrocatalyst for water oxidation, whereby ZIF-12 provide extra surface for the FeOOH dispersion whilst graphene act as excellent electron mediator. The composite shows a low overpotential value of 291 mV to attain a current density of 10 mA cm?2 and a low Tafel slope value of 78 mV dec?1. The catalyst offers a maximum current density of 101 mA cm?2, while it gives a turnover frequency (TOF) value of 0.031 s?1 at an overpotential of 291 mV only. The excellent activity and remarkable stability of composite is attributed to highly conductive and porous support. 相似文献
3.
1. Intracerebroventricular (i.c.v.) injection of choline (25-150 micrograms) increased blood pressure in rats made acutely hypotensive by haemorrhage. Intraperitoneal administration of choline (60 mg kg-1) also increased blood pressure, but to a lesser extent. Following i.c.v. injection of 25 micrograms or 50 micrograms of choline, heart rate did not change, while 100 micrograms or 150 micrograms i.c.v. choline produced a slight and short lasting bradycardia. Choline (150 micrograms) failed to alter the circulating residual volume of blood in haemorrhaged rats. 2. The pressor response to i.c.v. choline (50 micrograms) in haemorrhaged rats was abolished by pretreatment with mecamylamine (50 micrograms, i.c.v.) but not atropine (10 micrograms, i.c.v.). The pressor response to choline was blocked by pretreatment with hemicholinium-3 (20 micrograms, i.c.v.). 3. The pressor response to i.c.v. choline (150 micrograms) was associated with a several fold increase in plasma levels of vasopressin and adrenaline but not of noradrenaline and plasma renin. 4. The pressor response to i.c.v. choline (150 micrograms) was not altered by bilateral adrenalectomy, but was attenuated by systemic administration of either phentolamine (10 mg kg-1) or the vasopressin antagonist [beta-mercapto-beta,beta-cyclopenta-methylenepropionyl1, O-Me-Tyr2,Arg8]-vasopressin (10 micrograms kg-1). 5. It is concluded that the precursor of acetylcholine, choline, can increase and restore blood pressure in acutely haemorrhaged rats by increasing central cholinergic neurotransmission. Nicotinic receptor activation and an increase in plasma vasopressin and adrenaline level appear to be involved in this effect of choline. 相似文献
4.
Enhanced Image Detection on an ARM based Embedded System 总被引:2,自引:0,他引:2
This paper presents a new technique for thedetection of Integrated Circuits within images of Printed Circuit Boards autonomouslyand without the need to be assisted by CAD data. The technique is a key partof a suite of algorithms targeted for an embedded System On Chip architecturebased on the ARM7 platform for real time detection of PCB images for diagnosticpurposes. The technique has a significant reduction in complexity when comparedto conventional approaches such as the Hough Transform. The reduction in complexitymakes the approach ideal for an embedded vision application suchas the one described in this paper. This paper presents the technique, thetarget embedded architecture and results showing the reduction in complexitywhen compared to a Hough Transform. 相似文献
5.
首先以 HERMLE C1200 U 为例分析了五轴铣削加工中心的基本结构,然后据此给出了涉及多轴铣削加工中心后置处理角度分配和坐标变换的数学模型,最后介绍了以此数学模型为核心,为UG 软件开发的后置处理软件 UG-HERP1.0的解决方案。 相似文献
6.
The corrosion mechanism and microstructural characteristics of yttria (Y2 O3 ) exposed to uranium hexafluoride (UF4 ) and uranium tetrafluoride gases at temperatures above 900°C were investigated. Processed yttria samples were exposed for times ranging from 5 to 40 min. A weight increase was observed after each test exposure. An outer corrosion scale composed of UO2 and YF3 , and an inner corrosion layer of YF3 , were observed following the UF6 reaction at nearly 1200 K. During the UF4 exposure, an outer layer containing a liquid mixture of fluoride, oxygen, yttrium, uranium compounds, a secondary reaction layer of UO2 followed by an inner layer composed of a solution of Y2 O3 and YF3 , possibly in the form of YOF inner layer, were observed. It was found that the corrosion process is controlled by the diffusion which is evidenced by the parabolic growth rate of the secondary layer. After completion of the solidification process, the formation of a eutectic region and dendrites were observed throughout the outer scale. In general, at temperatures above 1173 K, high corrosion rates were observed, and yttria did not appear to be a viable containment material for UF4 and UF6 . 相似文献
7.
Development of a suitable model for characterizing photovoltaic arrays with shaded solar cells 总被引:2,自引:0,他引:2
The aim of this study is to investigate the effects of non-uniform solar irradiation distribution on energy output of different interconnected configurations in photovoltaic (PV) arrays. In order to find which configuration is less susceptible to mismatch effects, a PV module model is developed. This model can take into consideration the effects of bypass diodes and the variation of the equivalent circuit parameters with respect to operating conditions. The proposed model can provide sufficient degree of precision as well as solar cell-based analysis in analyzing large scale PV arrays without increasing the computational effort. In order to produce more reliable and robust simulations, improved and extended algorithms are presented. Some results are discussed in detail and some recommendations are extracted by testing several shading scenarios. 相似文献
8.
. A knowledge-based expert system was developed to aid in the selection of the type of dam. The dam type selector expert system
(DTSA ES) was designed to determine the type of dam on the alluvium foundations. Detailed expert knowledge is required to
estimate the type of dam and to develop an expert system. The DTSA ES utilizes rules of thumb used by an expert for determining
the selection of the type of dam. The DTSA ES was developed using a shell program. The expert system was tested on several
dam sites in order to validate the decision obtained. The use of this expert system, containing knowledge about the selection
of dam type, can be helpful to students, potential owners or contractors in selecting dam types. The current prototype always
needs additional parameters for more detailed analyses of new developments. However, the current DTSA ES is designed to include
existing information about dam types. 相似文献
9.
Meraj Talha Rauf Hafiz Tayyab Zahoor Saliha Hassan Arslan Lali M. IkramUllah Ali Liaqat Bukhari Syed Ahmad Chan Shoaib Umar 《Neural computing & applications》2021,33(17):10737-10750
Neural Computing and Applications - Lung cancer is a deadly disease if not diagnosed in its early stages. However, early detection of lung cancer is a challenging task due to the shape and size of... 相似文献
10.
Asmaa Al-Naqi Ahmet T. Erdogan Tughrul Arslan 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2013,17(7):1145-1157
This paper presents a new adaptive algorithm that aims to control the exploration/exploitation trade-off dynamically. The algorithm is designed based on three-dimensional cellular genetic algorithms (3D-cGAs). In this study, our methodology is based on the change in the global selection pressure induced by dynamic tuning of the local selection rate. The parameter tuning of the local selection method is a way to define the global selection pressure. A diversity speed measure is used to guide the algorithm. Therefore, the integration of existing techniques helps in achieving our aims. A benchmark of well-known continuous test functions and real world problems was selected to investigate the effectiveness of the algorithm proposed. In addition, we provide a comparison between the proposed algorithm and other static and dynamic algorithms in order to study the different effects on the performance of the algorithms. Overall, the results show that the proposed algorithm provides the most desirable performance in terms of efficiency, efficacy, and speed for most problems considered. The results also confirm that problems of various characteristics require different selection pressures, which are difficult to be identified. 相似文献