首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   42篇
  免费   0篇
教育   13篇
科学研究   27篇
信息传播   2篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2016年   1篇
  2015年   1篇
  2014年   4篇
  2013年   4篇
  2012年   4篇
  2011年   3篇
  2010年   3篇
  2009年   3篇
  2008年   1篇
  2005年   1篇
  2004年   1篇
  2002年   1篇
  2001年   3篇
  2000年   2篇
  1998年   2篇
  1996年   2篇
  1994年   1篇
  1991年   1篇
排序方式: 共有42条查询结果,搜索用时 15 毫秒
31.
We present here a set of simple experiments through which various characteristics of a DC motor can be investigated. The experiments also provide insights on how to control a DC motor. We first study the back-emf versus angular speed and the torque versus current characteristics. We then extract the moment of inertia of the rotor and the speedtorque curve for the load from the start-stop dynamics of the motor. Finally, we study an alternate way of obtaining the angular speed from the back-emf waveform.  相似文献   
32.
Hemoglobin D exist in four form; HbD trait, HbD-thalassemia, HbD sickle cell and HbD homozygous. HbD trait and HbD homozygous generally asymptomatic condition but when HbD co-inherit with thalassemia and sickle cell anemia, produces clinically significant conditions like chronic hemolytic anemia. Here we present a case of HbD Punjab with α 3.7 kb deletion and IVS-1-5 β-thalassemia across a family. Diagnosis of HbD patient was performed by high performance liquid chromatography and complete blood count was measured by automated cell analyzer. Molecular study for common alpha deletions done by Gap-PCR while beta thalassemia mutation identified by ARMS-PCR. Case was clinically significant due to the inheritance of HbD/β+thalassemia genotype. Thus observed case behaved like thalassemia intermedia due to co-existence of α 3.7 deletions with IVS 1-5 β-thalassemia mutation in HbD Punjab patient.  相似文献   
33.
Usually sickle cell traits are asymptomatic but co-existence of various factrors may alter the clinical as well as biochemical levels. In India sickle cell traits are neglected condition. Here we are presenting the alpha deletion in association with low serum iron and increased HbF level with Xmn-1 carriers in sickle cell traits. Sickle traits with alpha deletions had significantly low level of serum iron (P-value <0.05) with low level of reticulocytes and red cell indices while Xmn-1 polymorphism associated with increased HbF level. Study concludes low serum iron associated with alpha deletions and high level of HbF associated with Xmn-1 polymorphism in sickle cell traits.  相似文献   
34.
Stroke is the third major cause of death and foremost cause of disability worldwide. Cerebrovascular stroke remains largely a clinical diagnosis. The use of biomarkers in diagnosing stroke and assessing prognosis is an emerging and rapidly evolving field. The study aimed to investigate the predictive value of neurobiochemical marker of brain damage (neuron-specific enolase [NSE]) with respect to degree of disability at the time of admission and neurological worsening in acute ischemic stroke patients. We investigated 150 patients with cerebrovascular stroke who were admitted within 72 h of onset of stroke in the Department of Neurology at SAIMS. Venous blood samples were taken after admission and NSE was analyzed by solid enzyme linked immunosorbent assay using Analyzer and microplate reader from Biored: Code 680. In all patients, the neurological status was evaluated by a standardized neurological examination and the National Institutes of Health Stroke Scale on admission and on day 7. Serum NSE concentration was found to significantly correlate with both degree of disability and neurological worsening in acute ischemic stroke cases in the present study. The maximum serum NSE level within 72 h of admission was significantly higher in patients with greater degree of disability at the time of admission. Serum NSE levels were also found to be significantly elevated in patients with bad neurological outcome. Our study showed that serum NSE has high predictive value for determining severity and early neurobehavioral outcome after acute stroke.  相似文献   
35.
Despite the accepted need for strategic alignment in the manufacturing strategy literature, there has been relatively little research aimed at simultaneously aligning decisions in the structural and infrastructural areas with the competitive priorities of an organization. This article attempts to bridge the gap by examining how work force management practices, an infrastructural decision, should be aligned with both the process technology of a manufacturing plant, a structural decision, and its competitive priorities. A conceptual model for linking competitive priorities, process technologies, and work force management practices is presented, and specific and testable propositions are developed for future empirical research. The proposed conceptual model is based on the premise that the process of matching work force management practices to competitive priorities involves identification of the key managerial tasks underlying various competitive priorities. These tasks, in turn, are matched with the process technology characteristics and work force management practices to seek a good fit, which is expected to improve manufacturing performance.  相似文献   
36.
A new method is demonstrated to transport particles, cells, and other microorganisms using rectified ac electro-osmotic flows in open microchannels. The rectified flow is obtained by synchronous zeta potential modulation with the driving potential in the microchannel. Experiments were conducted to transport both neutral, charged particles, and microorganisms of various sizes. A maximum speed of 50 μm∕s was obtained for 8 μm polystyrene beads, without any electrolysis, using a symmetrical square waveform driving electric field of 5 V∕mm at 10 Hz and a 360 V gate potential with its polarity synchronized with the driving potential (phase lag=0°).  相似文献   
37.
The nematodes (worms) Caenorhabditiselegans and Caenorhabditisbriggsae are well-known model organisms to study the basis of animal development and behaviour. Their sinusoidal pattern of movement is highly stereotypic and serves as a tool to monitor defects in neurons and muscles that control movement. Until recently, a simple yet robust method to initiate movement response on-demand did not exist. We have found that the electrical stimulation in a microfluidic channel, using constant DC electric field, induces movement (termed electrotaxis) that is instantaneous, precise, sensitive, and fully penetrant. We have further characterized this behaviour and, in this paper, demonstrate that electrotaxis can also be induced using a pulse DC electric signal. Worms responded to pulse DC signals with as low as 30% duty cycle by moving towards the negative electrode at the same speed as constant DC fields (average speed of C. elegans?=?296?±?43?μm/s and C. briggsae?=?356?±?20?μm/s, for both constant and pulse DC electric fields with various frequencies). C. briggsae was found to be more sensitive to electric signals compared to C. elegans. We also investigated the turning response of worms to a change in the direction of constant and pulse DC signals. The response for constant DC signal was found to be instantaneous and similar for most worms. However, in the case of pulse DC signal, alterations in duty cycle affected the turning response time as well as the number of responding worms. Our findings show that pulse DC method allows quantitative measurement of response behaviour of worms and suggest that it could be used as a tool to study the neuronal basis of such a behaviour that is not observed under constant DC conditions.  相似文献   
38.
39.
40.
Helminths are known to modulate host’s immune system and understanding this modulation can help in identification of novel therapeutic agents for autoimmune diseases. In this study, we have assessed the immune-modulatory activity and the therapeutic effect of Brugia malayi recombinant cystatin (rBmCys) in methylated BSA (mBSA) induced arthritis using rodent model. Administration of rBmCys has suppressed the severity of mBSA-arthritis in mastomys by reducing paw swelling and other clinical disease parameters as evident from significantly decreased arthritic index. The anti-arthritic effect of rBmCys was also confirmed by decreased histopathological score for synovitis, bone erosion and fibrosis in the tissue sections of paws. Further, this therapeutic effect of cystatin was found to be associated with significantly decreased production of IFN-γ and TNF-α and increased release of IL-4 and IL-10 cytokines. These results implied that rBmCys treatment has alleviated mBSA-induced arthritis and thus can be a promising alternative agent for the treatment of arthritis.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号