全文获取类型
收费全文 | 406829篇 |
免费 | 27616篇 |
国内免费 | 2321篇 |
专业分类
耳鼻咽喉 | 4974篇 |
儿科学 | 9397篇 |
妇产科学 | 8250篇 |
基础医学 | 56127篇 |
口腔科学 | 7834篇 |
临床医学 | 39870篇 |
内科学 | 82921篇 |
皮肤病学 | 7647篇 |
神经病学 | 35819篇 |
特种医学 | 16227篇 |
外国民族医学 | 11篇 |
外科学 | 59282篇 |
综合类 | 5555篇 |
现状与发展 | 5篇 |
一般理论 | 395篇 |
预防医学 | 30662篇 |
眼科学 | 10645篇 |
药学 | 30229篇 |
6篇 | |
中国医学 | 1942篇 |
肿瘤学 | 28968篇 |
出版年
2023年 | 2272篇 |
2022年 | 5050篇 |
2021年 | 10066篇 |
2020年 | 5595篇 |
2019年 | 8697篇 |
2018年 | 10174篇 |
2017年 | 7563篇 |
2016年 | 8963篇 |
2015年 | 11268篇 |
2014年 | 15220篇 |
2013年 | 19846篇 |
2012年 | 30063篇 |
2011年 | 30596篇 |
2010年 | 17499篇 |
2009年 | 15237篇 |
2008年 | 25411篇 |
2007年 | 26110篇 |
2006年 | 25227篇 |
2005年 | 24798篇 |
2004年 | 22882篇 |
2003年 | 20857篇 |
2002年 | 19124篇 |
2001年 | 6437篇 |
2000年 | 5603篇 |
1999年 | 5548篇 |
1998年 | 4323篇 |
1997年 | 3497篇 |
1996年 | 3092篇 |
1995年 | 2925篇 |
1994年 | 2476篇 |
1993年 | 2185篇 |
1992年 | 2814篇 |
1991年 | 2709篇 |
1990年 | 2336篇 |
1989年 | 2196篇 |
1988年 | 2108篇 |
1987年 | 1970篇 |
1986年 | 1947篇 |
1985年 | 1834篇 |
1984年 | 1854篇 |
1983年 | 1673篇 |
1982年 | 1754篇 |
1981年 | 1685篇 |
1980年 | 1472篇 |
1979年 | 1219篇 |
1978年 | 1151篇 |
1977年 | 1019篇 |
1976年 | 923篇 |
1975年 | 767篇 |
1974年 | 828篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
The study reports on a questionnaire study of final-year medical students' self-reported attitudes to dealing with dying patients. All respondents had some direct clinical experience with dying patients, and reported that such encounters were largely unproblematic. Alleviating patient anxiety and counseling relatives were seen as important aspects of the doctor's role, along with diagnosis, and management of symptoms. “High fear” respondents were more likely to report difficulty in discussing the prognosis with the dying and to experience minor psychological problems. 相似文献
943.
Twenty patients with major depressive disorder were studied with evoked potential (EP) topographic mapping after receiving placebo, imipramine, or amoxapine for 2 days in a random-assignment, double-blind design. Patients performed the Continuous Performance Test (CPT), a visual vigilance test. The stimuli were the digits 0-9, with 0 a target to be responded to with a button press. EPs were recorded from 32 channels and were averaged separately for detected and undetected targets and for false positives and correctly identified nontargets (no button press). Twenty-one normal controls were also tested. Amoxapine enhanced N120 amplitude in midline parietal and right parietal cortex where selective attention effects have been found to be greatest in studies of normal controls. Both amoxapine and imipramine enhanced differences in P200 between target and nontarget stimuli in comparison to placebo, with amoxapine differences again being greatest over midline parietal locations. CPT performance was significantly better on amoxapine than placebo. 相似文献
944.
Herschman Harvey R.; Lim Robert W.; Brankow David W.; Fujiki Hirota 《Carcinogenesis》1989,10(8):1495-1498
Okadaic acid (OA) and 12-O-tetradecanoylphorbol-13-acetate (TPA)are both potent tumor promoters in a mouse skin carcinogenesisexperiment. OA was much more toxic than TPA for murine embryocell lines such as Swiss 3T3 cells or C3H10T? cells. TPA isa potent mitogen for 3T3 cells; in contrast OA was unable tostimulate DNA synthesis in these cells. TPA induces a familyof primary response genes, the TPA induced sequence (TIS) genes,in a wide variety of cells. Although OA induced modest levelsof TIS mRNA expression, the time course of the induction ofTIS1 and TIS8 mRNA was delayed when compared to induction byTPA or peptide mitogeas such as fibroblast growth factor (FGF).In addition TPA-mediated down-regulation of protein kinase Cattenuated TIS gene induction by OA, but not by FGF. 相似文献
945.
For more than two decades, microsurgery has been developed, practiced, and refined in China. For the most part, this has taken place independent of a parallel process in the Western World. Only until recent years has there been some communication from China regarding this microsurgical experience. The authors believe that there is much yet to be learned from the wealth of Chinese experience in microsurgery, just as Chinese surgeons have gained valuable information from the West. The authors reviewed the microsurgical literature in China from 1983 to 1986, and present here what we regard to be of particular interest to American microsurgeons, including the areas of digital reconstruction, replantation, flap transfer and transposition, and microsurgical techniques and patient management. Some historical background in the development of Chinese microsurgery is also provided. 相似文献
946.
Premenstrual tension syndrome (PMS) is well known in its epidemiology, etiology, symptomatology and treatment. However, PMS characterized by bulimic episodes is rare. We report a case of a 20-year-old university student who suffered from uncontrollable binge eating premenstrually for six months before visiting our clinic. She was obese without any other notable family or medical history except the PMS noted for two years. A daily food diary for two consecutive menstrual cycles showed that the mean differences in caloric intake between premenstrual and postmenstrual days of two menstrual cycles were 679 and 703 calories, respectively. The greater peaks in caloric level were noted within the third to fifth days prior to the onset of menstruation. All binge episodes occurred in the premenstrual period, especially within five days prior to menstruation. In this report, we will also review the literature on the relationship between PMS and dietary intake, as well as bulimia nervosa. 相似文献
947.
T Hoshino L A Rodriguez K G Cho K S Lee C B Wilson M S Edwards V A Levin R L Davis 《Journal of neurosurgery》1988,69(6):839-842
The proliferative potential of low-grade astrocytomas was estimated in 47 patients. Each patient received an intravenous infusion of bromodeoxyuridine (BUdR), 150 to 200 mg/sq m, at the time of craniotomy to label cells in deoxyribonucleic acid (DNA) synthesis; the percentage of S-phase cells, or BUdR labeling index (LI), of each tumor was determined immunohistochemically. In 29 patients (60%), the tumors had BUdR LI's of less than 1%, indicating a slow growth rate; only three (10%) of these patients died of recurrent tumor during a follow-up period of up to 3 1/2 years. In contrast, of the 18 patients (40%) whose tumors had BUdR LI's of 1% or more, 12 (67%) had a recurrence and nine died during the same follow-up period. These results show that the proliferative potential, as reflected by the BUdR LI, is an important prognostic factor that separates low-grade astrocytomas into two groups and provides a more scientific rationale for selecting treatment for individual patients. 相似文献
948.
949.
Gastrointestinal damage associated with the use of nonsteroidal antiinflammatory drugs. 总被引:29,自引:0,他引:29
M C Allison A G Howatson C J Torrance F D Lee R I Russell 《The New England journal of medicine》1992,327(11):749-754
BACKGROUND. Long-term use of nonsteroidal antiinflammatory drugs (NSAIDs) may lead to inflammation of the small intestine associated with occult blood and protein loss. The aim of this study was to investigate the prevalence and structural correlates of this enteropathy. METHODS. We examined the stomach, duodenum, and small intestine of 713 patients post mortem. Of these patients, 249 had had NSAIDs prescribed during the six months before death and 464 patients had not. All visible small intestinal lesions were removed for histologic examination, and specific etiologic factors were sought. The prevalence of nonspecific small-intestinal ulcers and ulcers of the stomach and duodenum was compared in the two groups of patients. RESULTS. Nonspecific small-intestinal ulceration was found in 21 (8.4 percent) of the users of NSAIDs and 3 (0.6 percent) of the nonusers (difference, 7.8 percent; 95 percent confidence interval, 5.0 to 10.6 percent; P less than 0.001). Three patients who were long-term users of NSAIDs were found to have died of perforated nonspecific small-intestinal ulcers. Ulcers of the stomach or duodenum were found in 54 (21.7 percent) of the patients who used these drugs and 57 (12.3 percent) of those who had not (difference, 9.4 percent; 95 percent confidence interval, 3.9 to 15.1 percent; P less than 0.001). CONCLUSIONS. Patients who take NSAIDs have an increased risk of nonspecific ulceration of the small-intestinal mucosa. These ulcers are less common than ulcers of the stomach or duodenum, but can lead to life-threatening complications. 相似文献
950.
David Mann 《British Journal of Psychotherapy》1994,10(4):511-520
This paper introduces the idea of castration desire: the desire to lose the penis to strengthen identification with the mother, to deny difference and thereby maintain the phantasy of fusion. Castration desire is therefore linked to the regressive part of the personality that seeks to avoid differentiation. In this context, castration anxiety is seen as a later development that actively promotes separation and individuation from the mother. These issues are explored using clinical and mythological examples. 相似文献