全文获取类型
收费全文 | 737篇 |
免费 | 45篇 |
出版年
2023年 | 4篇 |
2022年 | 6篇 |
2021年 | 15篇 |
2020年 | 10篇 |
2019年 | 8篇 |
2018年 | 12篇 |
2017年 | 8篇 |
2016年 | 11篇 |
2015年 | 20篇 |
2014年 | 28篇 |
2013年 | 53篇 |
2012年 | 54篇 |
2011年 | 43篇 |
2010年 | 20篇 |
2009年 | 19篇 |
2008年 | 34篇 |
2007年 | 43篇 |
2006年 | 37篇 |
2005年 | 28篇 |
2004年 | 31篇 |
2003年 | 21篇 |
2002年 | 18篇 |
2001年 | 20篇 |
2000年 | 17篇 |
1999年 | 10篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1992年 | 11篇 |
1991年 | 6篇 |
1990年 | 9篇 |
1989年 | 9篇 |
1988年 | 9篇 |
1987年 | 9篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 6篇 |
1983年 | 9篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 5篇 |
1975年 | 7篇 |
1974年 | 11篇 |
1973年 | 14篇 |
1972年 | 10篇 |
1971年 | 6篇 |
1970年 | 4篇 |
1969年 | 6篇 |
排序方式: 共有782条查询结果,搜索用时 15 毫秒
141.
142.
E K Barbehenn B Wiggert L Lee C L Kapoor B A Zonnenberg T M Redmond J V Passonneau G J Chader 《Biochemistry》1985,24(6):1309-1316
A phosphodiesterase (PDE) has been characterized in the interphotoreceptor matrix (IPM) of light-adapted fresh bovine retinas. It is obtained through a gentle rinsing of the retinal surface under conditions where the light-activated rod outer segment (ROS) enzyme remains attached. The enzyme has an apparent native molecular weight of 350 000 by gel filtration and appears as a doublet at Mr 47 000 and 45 000 on sodium dodecyl sulfate-polyacrylamide gels. It has an apparent Km value for cGMP of 33 microM and an apparent Km value for cAMP of 2200 microM. It is activated 3-6-fold by protamine and over 40-fold by trypsin. Protamine has no effect on the Km for cGMP while trypsin decreases the Km for cGMP by a factor of 2. The enzyme occurs in at least two forms as evidenced by two distinct peaks of activity after gel electrophoresis under nondenaturing conditions. A heat-stable inhibitor is tightly bound to the enzyme. The inhibitor obtained from the IPM PDE inhibits 98% of the activity of the trypsin-activated ROS PDE: conversely, the inhibitor obtained by boiling the ROS PDE completely inhibits the trypsin-activated IPM enzyme. A high-affinity monoclonal antibody to the active site of the ROS PDE, ROS 1 [Hurwitz, R., Bunt-Milan, A.H., & Beavo, J. (1984) J. Biol. Chem. 259, 8612-8618], quantitatively absorbs the IPM PDE. These observations indicate a clear relationship between these two PDEs even though their location, sizes, and specific functions in the retina appear to be distinct. 相似文献
143.
P. Manjari Suresh Kapoor Iqbal Hyder S. De A. K. Mohanty A. K. Dang 《Biological Rhythm Research》2018,49(2):329-333
Implantation is a critical process wherein the dam accepts the semi-allogenic embryo, characterized by certain vital immunological changes involving certain factors and cytokines. The current study was undertaken in Sahiwal cows to analyze the changes in certain selective immunological components of the body during peri-implantation period. Post-insemination the study was performed for a period till day 40 and the plasma was used to estimate the levels of progesterone, interleukin 1β (IL-1β), IL-2, IL-4, IL-6, and leukemia inhibiting factor (LIF) using Bovine specific ELISA Test Kits. The phagocytic activity and mRNA expression of progesterone-induced blocking factor (PIBF) were also analyzed. It was observed that in pregnant cows, the expression of PIBF increased from day 16th onward and remained high throughout the study period whereas the phagocytic activity was higher in non-pregnant cows all through the study period. The IL-1β, IL-2, and IL-6 were significantly higher in non-pregnant cows from 16th to 18th day post-AI as compared to P cows. On the other hand, IL-4 and LIF showed a significantly higher concentration in pregnant cows during peri-implantation period. Hence, it can be concluded that early embryonic survival is dependent on interplay of certain critical immunological factors in the body. 相似文献
144.
Shomu Bohora Amit Vora Aditya Kapoor Vanita Arora Nitish Naik Raja Selvaraj Narayan Namboodiri Anil Saxena Ajay Naik Balbir Singh C. Narsimhan Mohan Nair T.S. Kler 《Indian pacing and electrophysiology journal》2018,18(6):188-192
Cardiac implantable electronic device (CIED) procedures are being done by many operators/centers and it is projected that this therapy will remarkably increase in India in the coming years. This document by IHRS, aims at guiding the Indian medical community in the appropriate use and method of implantation with emphasis on implanter training and center preparedness to deliver a safe and effective therapy to patients with cardiac rhythm disorders and heart failure. 相似文献
145.
Prostaglandin production contributes to exercise-induced vasodilation in heart failure 总被引:4,自引:0,他引:4
Lang Chim C.; Chomsky Don B.; Butler Javed; Kapoor Shiv; Wilson John R. 《Journal of applied physiology》1997,83(6):1933-1940
Lang, Chim C., Don B. Chomsky, Javed Butler, Shiv Kapoor,and John R. Wilson. Prostaglandin production contributes toexercise-induced vasodilation in heart failure. J. Appl. Physiol. 83(6): 1933-1940, 1997.Endothelial release of prostaglandins may contribute toexercise-induced skeletal muscle arteriolar vasodilation in patientswith heart failure. To test this hypothesis, we examined the effect ofindomethacin on leg circulation and metabolism in eight chronic heartfailure patients, aged 55 ± 4 yr. Central hemodynamics and legblood flow, determined by thermodilution, and leg metabolic parameterswere measured during maximum treadmill exercise before and 2 h afteroral administration of indomethacin (75 mg). Leg release of6-ketoprostaglandin F1 was alsomeasured. During control exercise, leg blood flow increased from 0.34 ± 0.03 to 1.99 ± 0.19 l/min(P < 0.001), legO2 consumption from 13.6 ± 1.8 to 164.5 ± 16.2 ml/min (P < 0.001), and leg prostanoid release from 54.1 ± 8.5 to267.4 ± 35.8 pg/min (P < 0.001).Indomethacin suppressed release of prostaglandinF1(P < 0.001) throughout exercise anddecreased leg blood flow during exercise(P < 0.05). This was associated witha corresponding decrease in leg O2 consumption (P < 0.05) and a higher level offemoral venous lactate at peak exercise(P < 0.01). These data suggest thatrelease of vasodilatory prostaglandins contributes to skeletal musclearteriolar vasodilation in patients with heart failure. 相似文献
146.
147.
ABSTRACTIn the spirit of ‘furthering debate and reflection’ in this response to Theories of Race and Ethnicity, we consider here the pertinence of the theme of resistance that occupies particular chapters within the collection and that has been central to key works within the wider race critical scholarship. Yet, when the larger field of contemporary race study is considered, we also note that other contiguous concerns – including capitalism, religion, nation, and war – are key factors in thinking through racism. Here, we further elaborate on how future theorizations of race and ethnicity must engage with these domains. 相似文献
148.
Seven strains of Mycoplasma mycoides subsp. mycoides (LC, Y-Goat) were isolated from 4 of 85 (4.7%) cases of bovine abortion. The biochemical characters of all the isolates were homogenous (except for one sucrose negative isolate), but variation in sensitivity to neomycin, kanamycin and streptomycin were noted. The only gross lesions of internal organs in aborted fetuses were congestion of liver and lungs, and hemorrhagic patches on the heart surface. Significant microscopic lesions were encountered in lungs (edema of the interlobular septae, thickened alveolar wall, lymphocytic infiltration, septal hyperplasia and alveolar infiltration with neutrophils and macrophages), liver (mild lymphocytic infiltration in the hepatic triad, hypertrophy of Von-kupffer cells), kidney (degenerative necrosis and desquamation of tubular epithelium, and the marked lymphocytic infiltration in the interstitium), spleen (depleted lymphoid tissues, infiltration of lymphocytes, macrophage and plasma cells in the red pulp) and heart (lymphocytic myocarditis). The observations of this study focus on the role of M. mycoides subsp. mycoides (LC variant) in bovine abortions. 相似文献
149.
N. N. Kapoor 《Hydrobiologia》1974,44(1):37-41
The gills of Paragnetina media function as true respiratory organs. The animals with all the thoracic gill removed did not respire more than a few minutes. The respiratory rates showed a correlation to the body weight. 相似文献
150.