全文获取类型
收费全文 | 1425篇 |
免费 | 168篇 |
国内免费 | 2篇 |
学科分类
医药卫生 | 1595篇 |
出版年
2022年 | 14篇 |
2021年 | 37篇 |
2020年 | 15篇 |
2019年 | 28篇 |
2018年 | 33篇 |
2017年 | 26篇 |
2016年 | 17篇 |
2015年 | 25篇 |
2014年 | 37篇 |
2013年 | 54篇 |
2012年 | 66篇 |
2011年 | 55篇 |
2010年 | 48篇 |
2009年 | 42篇 |
2008年 | 66篇 |
2007年 | 68篇 |
2006年 | 56篇 |
2005年 | 70篇 |
2004年 | 67篇 |
2003年 | 62篇 |
2002年 | 55篇 |
2001年 | 54篇 |
2000年 | 52篇 |
1999年 | 37篇 |
1998年 | 13篇 |
1997年 | 15篇 |
1996年 | 16篇 |
1995年 | 14篇 |
1994年 | 9篇 |
1993年 | 10篇 |
1992年 | 36篇 |
1991年 | 38篇 |
1990年 | 37篇 |
1989年 | 33篇 |
1988年 | 31篇 |
1987年 | 25篇 |
1986年 | 31篇 |
1985年 | 27篇 |
1984年 | 18篇 |
1983年 | 8篇 |
1982年 | 11篇 |
1981年 | 11篇 |
1980年 | 11篇 |
1979年 | 23篇 |
1978年 | 14篇 |
1977年 | 16篇 |
1976年 | 12篇 |
1973年 | 6篇 |
1972年 | 13篇 |
1970年 | 5篇 |
排序方式: 共有1595条查询结果,搜索用时 15 毫秒
1.
Nedocromil sodium inhibits IgE- and IgG-related antigen-induced contraction in guinea-pig trachea 总被引:1,自引:0,他引:1
C Bertrand E Tschirhart Y Landry 《International archives of allergy and applied immunology》1989,88(4):439-446
The effects of nedrocromil sodium and disodium cromoglycate were studied on the anaphylactic contraction of guinea-pig trachea in two models of active sensitization (IgE and IgG models). The influence of epithelial removal on the effects of nedocromil sodium and disodium cromoglycate was examined because several studies have shown that the epithelial layer can modulate agonist- or antigen-induced contractile responses. Disodium cromoglycate (10(-4) M) and nedocromil sodium (10(-4) M) provided significant protection against antigen-induced contractions of guinea-pig tracheal smooth muscle in the IgG model. But only nedocromil sodium had an effect at this concentration in the IgG model and was also effective at 10(-5) M in the epithelium-denuded tracheal strips. At this concentration, disodium cromoglycate lost its protective effect. Comparison with the results obtained with FPL-55712, AA-861 and mepyramine suggested that these drugs affect histamine and particularly leukotriene synthesis and/or release by mast cells or other immunocompetent cells. These findings indicate that nedocromil sodium inhibits the IgE- and IgG-related antigen-induced contraction in guinea-pig airways, whereas disodium cromoglycate inhibits only the IgG-related processes. This study supports the hypothesis that these drugs modulate antigen-induced mediator synthesis and/or release from immunocompetent cells. 相似文献
2.
S V Landry G R DeFoliart D B Hogg 《Journal of the American Mosquito Control Association》1988,4(2):121-128
Aedes triseriatus pupae, host-seeking, and ovipositing females were collected at a southern Wisconsin site endemic for La Crosse encephalitis virus. The host-seeking and ovipositing females were age-graded by the Detinova and Polovodova techniques, respectively. Wing lengths were determined for all mosquitoes. Wing lengths of the mosquitoes collected as pupae were predicted from pupal weight by a simple regression equation. There was significant seasonal variation in body size of adult females, but no strong evidence that increased size was advantageous to survival. It is concluded therefore that the potential length of infective life is not affected by the size of the adult female. 相似文献
3.
4.
Gregory C Gray Troy McCarthy Mark G Lebeck David P Schnurr Kevin L Russell Adriana E Kajon Marie L Landry Diane S Leland Gregory A Storch Christine C Ginocchio Christine C Robinson Gail J Demmler Michael A Saubolle Sue C Kehl Rangaraj Selvarangan Melissa B Miller James D Chappell Danielle M Zerr Deanna L Kiska Diane C Halstead Ana W Capuano Sharon F Setterquist Margaret L Chorazy Jeffrey D Dawson Dean D Erdman 《Clinical infectious diseases》2007,45(9):1120-1131
BACKGROUND: Recently, epidemiological and clinical data have revealed important changes with regard to clinical adenovirus infection, including alterations in antigenic presentation, geographical distribution, and virulence of the virus. METHODS: In an effort to better understand the epidemiology of clinical adenovirus infection in the United States, we adopted a new molecular adenovirus typing technique to study clinical adenovirus isolates collected from 22 medical facilities over a 25-month period during 2004-2006. A hexon gene sequence typing method was used to characterize 2237 clinical adenovirus-positive specimens, comparing their sequences with those of the 51 currently recognized prototype human adenovirus strains. In a blinded comparison, this method performed well and was much faster than the classic serologic typing method. RESULTS: Among civilians, the most prevalent adenovirus types were types 3 (prevalence, 34.6%), 2 (24.3%), 1 (17.7%), and 5 (5.3%). Among military trainees, the most prevalent types were types 4 (prevalence, 92.8%), 3 (2.6%), and 21 (2.4%). CONCLUSIONS: For both populations, we observed a statistically significant increasing trend of adenovirus type 21 detection over time. Among adenovirus isolates recovered from specimens from civilians, 50% were associated with hospitalization, 19.6% with a chronic disease condition, 11% with a bone marrow or solid organ transplantation, 7.4% with intensive care unit stay, and 4.2% with a cancer diagnosis. Multivariable risk factor modeling for adenovirus disease severity found that age <7 years (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.4-7.4), chronic disease (OR, 3.6; 95% CI, 2.6-5.1), recent transplantation (OR, 2.7; 95% CI, 1.3-5.2), and adenovirus type 5 (OR, 2.7; 95% CI, 1.5-4.7) or type 21 infection (OR, 7.6; 95% CI, 2.6-22.3) increased the risk of severe disease. 相似文献
5.
Summary— The regulation and role of the intracellular Ca2+ pools were studied in rat peritoneal mast cells. Cytosolic free calcium concentration ([Ca2+ ]i) was monitored in fura-2 loaded mast cells. In the presence of Ca2+ and K+, compound 48/80 induced a biphasic increase in [Ca2+ ]i composed of a fast transient phase and an apparent sustained phase. The sustained phase was partially inhibited by the addition of Mn2+ . DTPA, a cell-impermeant chelator of Mn2+ , reversed this inhibition, suggesting that a quenching of fura-2 fluorescence occurs in the extracellular medium. In the absence of extracellular Ca2+ , the transient phase, but not the sustained one, could be preserved, provided that mast cells were depolarized. The transient phase was completely abolished by thapsigargin, a microsomal Ca2+ -ATPase inhibitor. Maximum histamine release induced by either compound 48/80 or antigen was obtained in the absence of added Ca2+ only when mast cells were depolarized. These histamine releases were inhibited by low doses (< 30 nM) of thapsigargin. Thapsigargin at higher doses induced histamine release which was unaffected by changing the plasma membrane potential, but was completely dependent on extracellular Ca2+ , showing that a Ca2+ influx is required for thapsigargin-induced exocytosis. Together, these results suggest that the mobilization of Ca2+ from thapsigargin sensitive-intracellular pools induced by compound 48/80 or antigen is sufficient to trigger histamine release. The modulation of these pools by the plasma membrane potential suggest their localization is close to the plasma membrane. 相似文献
6.
7.
8.
9.
The possible colocalization of oxytocin (OT) and galanin (GAL) was studied by combining, on the same cryostat sections, in situ hybridization (ISH) for OT mRNA with a tritiated oligonucleotide probe and immunohistochemistry (ICC) of GAL. Many cells were either labelled by ISH (OT mRNA containing cells), or by ICC (GAL containing cells). Moreover, some magnocellular neurons in the supraoptic and paraventricular nuclei were labelled for both OT mRNA and GAL. These results demonstrate that some magnocellular neurons of the rat hypothalamus contain both GAL and OT. This approach is suitable for studying the intracellular distribution of OT gene expression and mature GAL under different physiological or experimental conditions. 相似文献
10.
Everyday memory following traumatic brain injury 总被引:1,自引:0,他引:1
G. Kinsella D. Murtagh A. Landry K. Homfray M. Hammond L. O'Beirne L. Dwyer M. Lamont J. Ponsford 《Brain injury : [BI]》1996,10(7):499-508
Residual memory deficits may represent a problem to the everyday functioning of a large number of people, including those who have sustained traumatic brain injury (TBI). The present exploratory study sought to investigate the interrelationships between subjective memory reports, performance on traditional memory tests, and performance on tests of prospective memory. These interrelationships were contrasted between a group of 24 adults who had sustained TBI and a group of 24 matched control subjects. Prospective memory was hypothesized to be indicative of everyday memory functioning. The results provided preliminary evidence that prospective memory tests are sensitive to TBIrelated neurological impairment and, in comparison to traditional tests, may be better indicators of functional memory capacity. This pattern was particularly true for control subjects, possibly because TBI subjects had difficulties in evaluating their memory functioning. 相似文献