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   1475728篇
  免费   119523篇
  国内免费   6513篇
耳鼻咽喉   19003篇
儿科学   47631篇
妇产科学   39681篇
基础医学   204184篇
口腔科学   40569篇
临床医学   132596篇
内科学   303056篇
皮肤病学   36103篇
神经病学   124547篇
特种医学   61170篇
外国民族医学   276篇
外科学   230678篇
综合类   32237篇
现状与发展   2篇
一般理论   456篇
预防医学   114743篇
眼科学   31144篇
药学   103295篇
  5篇
中国医学   2423篇
肿瘤学   77965篇
  2018年   16487篇
  2017年   13209篇
  2016年   16031篇
  2015年   17176篇
  2014年   23050篇
  2013年   35308篇
  2012年   43709篇
  2011年   47174篇
  2010年   28896篇
  2009年   27004篇
  2008年   44480篇
  2007年   47366篇
  2006年   48128篇
  2005年   46585篇
  2004年   44362篇
  2003年   43428篇
  2002年   41314篇
  2001年   70631篇
  2000年   73641篇
  1999年   59967篇
  1998年   18037篇
  1997年   16106篇
  1996年   16838篇
  1995年   16953篇
  1994年   15806篇
  1993年   14823篇
  1992年   47864篇
  1991年   46452篇
  1990年   44620篇
  1989年   42482篇
  1988年   39284篇
  1987年   38694篇
  1986年   36393篇
  1985年   35359篇
  1984年   27010篇
  1983年   22681篇
  1982年   14411篇
  1981年   12985篇
  1980年   12219篇
  1979年   24046篇
  1978年   17542篇
  1977年   14849篇
  1976年   13593篇
  1975年   14146篇
  1974年   16523篇
  1973年   15749篇
  1972年   14476篇
  1971年   13359篇
  1970年   12164篇
  1969年   11367篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
111.
Adverse ocular effects associated with niacin therapy.   总被引:2,自引:0,他引:2       下载免费PDF全文
In a retrospective survey of patients taking medication for hyperlipidaemia, those taking niacin (nicotinic acid) were more likely (p < 0.05) to report sicca syndromes, blurred vision, eyelid oedema, and macular oedema compared with those who never took niacin. Additionally, 7% of those taking niacin discontinued the drug owing to adverse ocular side effects, while none of the other lipid lowering agents were found to cause these side effects (p = 0.016). Data from spontaneous reporting systems support a possible association of decreased vision, cystoid macular oedema, sicca-like symptoms, discoloration of the eyelids with or without periorbital or eyelid oedema, proptosis, loss of eyebrow or eyelashes, and superficial punctate keratitis with the use of niacin in high doses. Decreased vision may be marked, and if the drug is not discontinued, may progress to cystoid macular oedema. All ocular side effects listed above are reversible if the association with niacin is recognised and the drug is discontinued; both the incidence and severity of the ocular side effects seem to be dose dependent.  相似文献   
112.
A case illustrating the potentially fatal complication of endogenous Gram Negative Aerobic Bacillus (GNAB) septicaemia secondary to nosocomial pneumonia is presented along with current theories as to its aetiology. The technique of selective decontamination of the digestive tract is designed and advocated to prevent such occurrences; oral and maxillofacial surgeons should be aware of this approach. It may be, however, that by using much simpler manoeuvres such as changes in policy regarding gastric stress ulcer prophylaxis, the already small risk of such an occurrence will be further reduced. Awareness of this condition will allow a higher index of suspicion when presented with catastrophic septic complications on the ITU and aid in more rational planning of antimicrobial therapy.  相似文献   
113.
Ethanol account for a significant fraction of the energy intake of persons consuming even moderate amounts of alcohol. A recent study has shown that although alcohol does not reveal itself as a layer floating at the top of a drink, metabolically it behaves more like oil than sugar.  相似文献   
114.
The effect of localized hyperthermia on blood flow and cis-diamminedichloroplatinum(II) (CDDP) pharmacokinetics in 7,12-dimethylbenz[a]anthracene-induced mammary adenocarcinomas was studied. Blood flow was determined in rat tumors and normal tissue immediately and 1, 2, and 3 h after local hyperthermia treatment (43 degrees C, 1 h) as well as in unheated tumors of rats. The rate of blood flow in the tumor was increased 1.9 times at the end of treatment relative to control values and returned to the control values by 3 h after hyperthermia. Similarly, the rate of blood flow in the peripheral skin around the tumor immediately after hyperthermia was 2.2 times greater than that of unheated skin and returned to near normal values by 3 h after heating. Tumor-bearing rats received CDDP 1 h before, at the beginning of, at the end of, and 1 h after hyperthermia administration. The CDDP plasma concentration versus time profiles for rats did not vary statistically between treatment groups. Two h after CDDP administration, the mean tumor CDDP concentration of the rats which received drug at the beginning of hyperthermia was statistically greater (P less than 0.05) than tumor CDDP concentrations in rats which received drug at the end of heat treatment. The latter group was given CDDP when tumor blood flow was the greatest; however, mean tumor drug concentration was lowest of all the groups. The mean drug concentration in tumor tissues of rats which received drug 1 h after hyperthermia was comparable to rats which received drug at the beginning of hyperthermia. This suggests that drug delivery or uptake in tumors may be altered when local hyperthermia is administered concurrently or sequentially.  相似文献   
115.
The anticarcinogenic action of the garlic constituent diallyl sulfide (DAS), was examined in the hamster buccal pouch and forestomach. Groups of hamsters were topically treated, for up to 14 weeks, with a 0.5% solution of the buccal pouch and forestomach carcinogen 7,12-dimethylbenz[a]anthracene (DMBA). Prior to, during and after DMBA treatment, groups of hamsters were also treated, on alternate days, with a 1% solution of DAS. In addition to tumor formation, the induction of gamma-glutamyl transpeptidase (gamma GT) buccal pouch epithelial lesions served as an additional presumptive index of in vivo carcinogenesis/anticarcinogenesis. DAS resulted in a significant reduction in buccal pouch tumor frequency, buccal pouch tumor burden, buccal pouch gamma GT lesion frequency and forestomach tumor frequency. In a separate experiment, DAS also reduced the level of autoradiographically quantified unscheduled DNA repair synthesis (UDS) in pieces of hamster buccal pouch concurrently exposed in vitro to the potent buccal pouch carcinogen N-methyl-N-benzylnitrosamine (MBN). This study demonstrates that DAS is an effective anticarcinogenic agent in squamous mucosa of the hamster and suggests novel cost-effective strategies for the rapid identification of tissue-specific anticarcinogens and a quantitative assessment of their efficacy.  相似文献   
116.
An increase in the number of cases of tuberculosis, especially in children, has been observed recently. Post-vaccination conversion rate in babies immunised with BCG was assessed. Sensitization was detected as early as 4 weeks after BCG inoculation. Although 84.2% had physical evidence of BCG inoculation only 69.8% had developed detectable sensitization to the tubercle bacilli as shown by the Mantoux test.  相似文献   
117.
L D Keith  J C Crabbe 《Alcohol》1992,9(6):529-533
The intent of this study was to determine whether chronic ethanol (EtOH) vapor inhalation, with or without adjunct pyrazole (PYR) administration, was stressful in mice, as defined by increases in plasma corticosterone (CORT) concentration. Mice were randomly assigned to groups differentiated both on the basis of EtOH vapor exposure and the presence or absence of PYR administration. Blood samples for blood EtOH concentration (BEC) and plasma CORT concentration were obtained from mice after 72-96 hours of treatment. Mice were sacrificed after 96 hours of treatment and body and adrenal weight determined. BEC was significantly higher in PYR-treated animals and animals treated with the higher EtOH vapor concentration. Plasma CORT was elevated in proportion to BEC; however, other nonspecific stresses, in particular that of PYR administration, also elevated plasma CORT. Nonspecific stresses associated with this protocol may reduce the generality of these observations. Nevertheless, the high correlation between BEC and plasma CORT concentration in the PYR groups indicates that, with suitable control groups, the PYR-EtOH vapor inhalation approach is viable for studies concerned with EtOH effects on hypothalamic-anterior pituitary-adrenocortical function.  相似文献   
118.
LUMBOVERTEBRAL SYNDROME AFTER EXTRADURAL BLOOD PATCH   总被引:2,自引:1,他引:1  
We describe a patient who developed an immobilizing lumbovertebralsyndrome after an extradural blood patch and who was hospitalizedwith a. suspected extradural abscess. An infectious aetiologyof the persistent backache could be excluded and the patientrecovered with analgesics and physiotherapy. The probable aetiologyis discussed.  相似文献   
119.
120.
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