全文获取类型
收费全文 | 3235448篇 |
免费 | 257751篇 |
国内免费 | 6663篇 |
专业分类
耳鼻咽喉 | 45983篇 |
儿科学 | 102204篇 |
妇产科学 | 89288篇 |
基础医学 | 453116篇 |
口腔科学 | 92508篇 |
临床医学 | 295940篇 |
内科学 | 632447篇 |
皮肤病学 | 69102篇 |
神经病学 | 272258篇 |
特种医学 | 127011篇 |
外国民族医学 | 1186篇 |
外科学 | 485279篇 |
综合类 | 78419篇 |
现状与发展 | 4篇 |
一般理论 | 1333篇 |
预防医学 | 262820篇 |
眼科学 | 76663篇 |
药学 | 236726篇 |
5篇 | |
中国医学 | 6554篇 |
肿瘤学 | 171016篇 |
出版年
2018年 | 34652篇 |
2017年 | 26564篇 |
2016年 | 29514篇 |
2015年 | 33347篇 |
2014年 | 48043篇 |
2013年 | 72769篇 |
2012年 | 98153篇 |
2011年 | 103759篇 |
2010年 | 61219篇 |
2009年 | 58554篇 |
2008年 | 97449篇 |
2007年 | 103496篇 |
2006年 | 104487篇 |
2005年 | 101666篇 |
2004年 | 97517篇 |
2003年 | 93810篇 |
2002年 | 91810篇 |
2001年 | 150915篇 |
2000年 | 155636篇 |
1999年 | 131069篇 |
1998年 | 38441篇 |
1997年 | 34814篇 |
1996年 | 34475篇 |
1995年 | 33062篇 |
1994年 | 30752篇 |
1993年 | 28814篇 |
1992年 | 103583篇 |
1991年 | 99585篇 |
1990年 | 95936篇 |
1989年 | 92211篇 |
1988年 | 85535篇 |
1987年 | 84127篇 |
1986年 | 79311篇 |
1985年 | 75779篇 |
1984年 | 57833篇 |
1983年 | 49293篇 |
1982年 | 30204篇 |
1981年 | 26873篇 |
1979年 | 53552篇 |
1978年 | 37788篇 |
1977年 | 31689篇 |
1976年 | 29786篇 |
1975年 | 31030篇 |
1974年 | 38155篇 |
1973年 | 36460篇 |
1972年 | 34215篇 |
1971年 | 31471篇 |
1970年 | 29759篇 |
1969年 | 27696篇 |
1968年 | 25634篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Outflow of aqueous humor following cyclodialysis or ciliochoroidal detachment in rabbit 总被引:1,自引:0,他引:1
Cyclodialysis and ciliochoroidal detachment were performed in three eyes of three rabbits and in three eyes of another three rabbits, respectively. After aspiration of the aqueous humor, 0.1 ml of 10% sodium fluorescein was injected intracamerally, and the eyeball was enucleated between 30 minutes and one hour after injection and prepared for fluorescence microscopy. Sodium fluorescein concentrations in the supraciliary space were much greater in the group with cyclodialysis or ciliochoroidal detachment than in the normal control group. These results suggest that (1) in the eye with cyclodialysis, the aqueous humor may freely gain access to the supraciliary space through the cleft between the anterior chamber and the supraciliary space and then be removed rapidly and (2) in the eye with ciliochoroidal detachment, the aqueous humor may pass through the uveoscleral outflow pathway. 相似文献
992.
993.
994.
The role of body temperature in the morbidity and mortality resulting from acute severe carbon monoxide (CO) poisoning (2400 ppm CO, 90 min) was investigated using an unanesthetized animal model. Modified Levine prepared female rats (left common carotid artery and jugular cannulated) displayed a lower rate of recovery period (4 hr) re-warming, and an increased mortality rate and behaviorally-assessed neurologic index (NI) compared to normal rats. This indicated their greater susceptibility to CO hypoxia, although the degree of CO-induced hypothermia was the same in both groups. The whole-body cooling of Levine rats to a similar extent prior to CO exposure increased somewhat the post-CO re-warming rate, and marginally decreased NI and mortality during CO exposure (in-CO). In contrast, maintenance of constant body temperature by external heating during CO exposure resulted in a negative post-CO re-warming rate and sharply increased NI and in-CO mortality. Normal euthermic rats were much less severely affected by CO. The results suggest that hypothermia, whether CO-induced or produced by prior cooling, provides measurable protection of brain function during acute severe CO poisoning, and that maintenance of body temperature increases in-CO mortality and interferes with ability to thermoregulate and increases NI in survivors. 相似文献
995.
The epidemiology of viral hepatitis in US Navy enlisted personnel was reviewed for the years 1975-1984. Hospital discharge summaries of all active duty enlisted personnel admitted to a US Navy treatment facility were used for the study. From 1975 to 1984, total first hospitalizations for viral hepatitis declined from 128 per 100,000 personnel (95% confidence interval (Cl) 118-139) to 56 per 100,000 personnel (95% Cl 50-63). The highest incidence of acute viral hepatitis (115 per 100,000 personnel) was found in the youngest age groups aged 24 years and less. Risk factors for acute hepatitis included a previous hospitalization with either drug abuse (relative risk = 363) or a sexually transmitted disease (relative risk = 25) listed among the discharge diagnoses. Having a medical job classification was also associated with an increased risk of acute hepatitis. The steep decline in the incidence of viral hepatitis during this 10-year period may have been due to decreasing drug abuse in the US Navy. Immunization of high-risk groups in the US Navy with hepatitis B vaccine could be an effective policy for the prevention of acute viral hepatitis. 相似文献
996.
Knowledge of the health status of, and patterns of health care service utilization by rural Australian communities, is scant. This deficiency limits attempts to formulate policies designed to bring about efficient, effective and equitable delivery of health care services. This article reports the results of a health interview survey conducted in the Wimmera region of Victoria during spring 1984. The results demonstrate not only that patterns of morbidity in rural areas differ from the Australian average, but also that the health status of rural dwellers is worse than that of most Australians. Evidence suggests that while accessibility is not the most significant determinant of utilization of health care services, distance from services does affect propensity to use them. 相似文献
997.
J A Garrett J L Stewart 《Asia-Pacific journal of public health / Asia-Pacific Academic Consortium for Public Health》1989,3(3):213-218
In less than two decades, there has been a dramatic reduction in the prevalence of otitis media and perforations among Guam's school-aged children. In addition, hearing loss due to chronic middle ear disease as a cause of disqualification from military service has dropped from a first rank order cause to next-to-last. However, there has been no reduction in the prevalence of otitis media in the preschool population. The reduction in chronic ear disease is the result of improved access to primary care, intensive hearing screening, wide availability of audiologic diagnostic and follow-up services, and comprehensive otologic care. It is essential that these services continue to be available to Guam's children to avoid a reversal of these dramatic gains. Attention must now focus on how to achieve similar gains for Micronesian children who remain restricted in their access to these resources. 相似文献
998.
Conformationally restricted analogues of the selective partial muscarinic agonist N-methyl-N-(1-methyl-4-pyrrolidino-2-butynyl)acetamide (BM 5; 2) were synthesized. The compounds were tested for muscarinic and antimuscarinic activity in the isolated guinea pig ileum and in intact mice. They were found to be moderately potent muscarinic antagonists or weak partial agonists. The new compounds were less potent than 2 in inhibiting (-)-[3H]-N-methylscopolamine binding in the rate cerebral cortex. Thus, structural modifications of 2 in which part of the amide moiety has been connected with the methyl group in the butynyl chain to form a five-membered ring decrease affinity and in most cases abolish efficacy. 相似文献
999.
1000.
Pharmacological properties of fluphenazine-mustard, an irreversible calmodulin antagonist 总被引:1,自引:0,他引:1
We describe an improved synthesis and properties of fluphenazine-mustard, a potent phenothiazine having an alkylating chlorethylamine chain in its structure. The drug possesses anticalmodulin activity equivalent to the parent compound, but unlike fluphenazine dihydrochloride, the mustard derivative irreversibly antagonizes the ability of calmodulin to activate cyclic nucleotide phosphodiesterase. This property is partially calcium-dependent and can be overcome by coincubation with excess fluphenazine dihydrochloride. The compound irreversibly inactivated calmodulin when incubated with intact cells and caused single-stranded breakage of DNA. Fluphenazine-mustard possesses potent antiproliferative and cytotoxic properties against malignant cell lines that are likely to be mediated through both of these actions. 相似文献