全文获取类型
收费全文 | 36316篇 |
免费 | 2410篇 |
国内免费 | 127篇 |
专业分类
耳鼻咽喉 | 277篇 |
儿科学 | 910篇 |
妇产科学 | 624篇 |
基础医学 | 5306篇 |
口腔科学 | 541篇 |
临床医学 | 3403篇 |
内科学 | 8570篇 |
皮肤病学 | 863篇 |
神经病学 | 3024篇 |
特种医学 | 1183篇 |
外国民族医学 | 3篇 |
外科学 | 5350篇 |
综合类 | 359篇 |
一般理论 | 31篇 |
预防医学 | 2758篇 |
眼科学 | 819篇 |
药学 | 2247篇 |
1篇 | |
中国医学 | 66篇 |
肿瘤学 | 2518篇 |
出版年
2022年 | 293篇 |
2021年 | 606篇 |
2020年 | 340篇 |
2019年 | 567篇 |
2018年 | 700篇 |
2017年 | 470篇 |
2016年 | 542篇 |
2015年 | 637篇 |
2014年 | 911篇 |
2013年 | 1391篇 |
2012年 | 2076篇 |
2011年 | 2265篇 |
2010年 | 1341篇 |
2009年 | 1297篇 |
2008年 | 2096篇 |
2007年 | 2307篇 |
2006年 | 2222篇 |
2005年 | 2407篇 |
2004年 | 2186篇 |
2003年 | 2074篇 |
2002年 | 2058篇 |
2001年 | 510篇 |
2000年 | 459篇 |
1999年 | 523篇 |
1998年 | 504篇 |
1997年 | 452篇 |
1996年 | 376篇 |
1995年 | 373篇 |
1994年 | 335篇 |
1993年 | 319篇 |
1992年 | 396篇 |
1991年 | 394篇 |
1990年 | 342篇 |
1989年 | 326篇 |
1988年 | 286篇 |
1987年 | 276篇 |
1986年 | 278篇 |
1985年 | 267篇 |
1984年 | 269篇 |
1983年 | 251篇 |
1982年 | 276篇 |
1981年 | 276篇 |
1980年 | 228篇 |
1979年 | 163篇 |
1978年 | 162篇 |
1977年 | 168篇 |
1976年 | 132篇 |
1975年 | 128篇 |
1974年 | 121篇 |
1973年 | 115篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
91.
Marsha Bernard Kuhar 《AAOHN journal》2002,50(8):360-364
1. The Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATPIII) will significantly increase the number of Americans treated for hypercholesterolemia. 2. The ATPIII focuses on lowering low density lipoprotein cholesterol as a primary initiative and using exercise, diet, and pharmacotherapy as a means for lowering coronary heart disease and risks. 3. The new guidelines list low density lipoprotein cholesterol levels of less than 100 mg/dL as optimal for all clients. 4. The ATPIII places increased attention on high triglyceride levels (> 200 mg/dL) and on early detection and appropriate aggressive treatment for clients at risk for coronary heart disease and events. 相似文献
92.
93.
Perioperative Hearing Impairment 总被引:4,自引:0,他引:4
94.
Marko Simunovic Eddy Rempel Marc-Erick Thériault Angela Coates Timothy Whelan Eric Holowaty Bernard Langer Mark Levine 《Canadian journal of surgery》2006,49(4):251-258
BACKGROUND: There is a lack of information from Canadian hospitals on the role of hospital characteristics such as procedure volume and teaching status on the survival of patients who undergo major cancer resection. Therefore, we chose to study these relationships using data from patients treated in Ontario hospitals. METHODS: We used the Ontario Cancer Registry from calendar years 1990-2000 to obtain data on patients who underwent surgery for breast, colon, lung or esophageal cancer or who underwent major liver surgery related to a cancer diagnosis between 1990 and 1995 in order to assess the influence of volume of procedures and teaching status of hospitals on in-hospital death rate and long-term survival. For each disease site and before observing patient outcomes data, volume cut-off points were selected to create volume groups with similar numbers of patients. Teaching hospitals were those directly affiliated with a medical school. Logistic regression and proportional hazards models were used to consider the clustering of data at the hospital level and to assess operative death and long-term survival. We also used 4 measures to gauge the degree of procedure regionalization across the province including (1) the number of hospitals performing a procedure; (2) the percentage of patients treated in teaching hospitals; (3) the percentage of rural patients treated in higher volume procedure hospitals; and (4) median distances travelled by patients to receive care. RESULTS: The number of patients in our cohorts who underwent resection of the breast, colon, lung, esophagus or liver was 14 346, 8398, 2698, 629 and 362, respectively. Surgery in a high-volume versus a low-volume hospital did not have a statistically significant influence on the odds of operative death for patients who underwent colon, liver, lung or esophageal cancer resection. The risk of long-term death was increased in low-volume versus high-volume hospitals for patients who underwent resection of the breast (hazard ratio [HR] 1.2, 95% confidence interval [95% CI] 1.0-1.4, p < 0.05), lung (HR 1.3, 95% CI 1.1-1.6, p < 0.01) and liver (HR 1.7, 95% CI 1.0-2.7, p = 0.04). There were no significant differences in the odds of operative (in-hospital) death or risk of long-term death among patients treated in teaching compared with nonteaching hospitals. There was more regionalization of liver, lung and esophageal operations versus breast and colon operations. CONCLUSIONS: Increased hospital procedure volume correlated with improved longterm survival for patients in Ontario who underwent some, but not all, cancer resections, whereas hospital teaching status had no significant impact on patient outcomes. Across the province, further regionalization of care may help improve the quality of some cancer procedures. 相似文献
95.
96.
Human xenoreactive natural antibodies of the IgM isotype activate pig endothelial cells 总被引:1,自引:0,他引:1
Abstract: Preformed, xenoreactive natural antibodies (XNA) and complement (C) are involved in the initiation of vascular rejection of organs transplanted between discordant species, presumably by stimulating donor organ endothelial cells (EC). Although C is known to play a role in the activation of EC, it has not been clear whether the antibodies serve only to anchor the initial components of C, and thus permit the C cascade to proceed, or whether the antibodies themselves deliver a signal to the EC. We have tested affinity-purified human IgM containing XNA (IgM-XNA) for its ability to stimulate in vitro the up-regulation of genes in pig EC. Northern blot analysis shows that IgM, which contains XNA, stimulates mRNA accumulation for certain genes (including IL-8, PAI-1, and ECI-7, a new gene that we have found is associated with EC activation), but not others known to be up-regulated in response to TNF, IL-1 or LPS. Our results show that XNA provide a signal to EC, and thus may themselves participate in activation of EC and consequent vascular rejection. 相似文献
97.
Orlando Parise Franois Janot Bernard Luboinski Liliane Massaad Nicolas Albin Caroline Toussaint Marie-Ange Verjus Marc Bonnay Alain Gouyette Guy G. Chabot 《Head & neck》1994,16(2):158-164
Background. Head and neck squamous cell carcinomas (HNSCC) present variable aggressiveness and chemosensitivity. Because the glutathione (GSH) system and thymidylate synthase (TS) are involved in the resistance to the main drugs used in HNSCC (cisplatin and 5-FU), we studied these systems in tumors and normal mucosae. Methods. Tumor samples and normal adjacent mucosae were collected from 37 untreated HNSCC patients. GSH and glutathione S-transferase (GST) activity were assayed by spectrophotometry, whereas TS activity and folates were determined by radioassays. Results. Mean GSH levels were higher in tumors (15.2 ± 8.2 nmol/mg protein) than in mucosae (8.3 ± 4.1 nmol/mg protein) (p = 0.005, paired t test). GST activity was also higher in tumors (394 ± 194 nmol/min/mg protein) than in mucosae (261 ± 132 nmol/min/mg protein) (p = 0.0003). TS activity was markedly higher in tumors (9.2 ± 21.5 pmol/min/mg protein) compared to that of mucosae (0.9 ± 1.2 pmol/min/mg protein) (p = 0.0001). Folate levels in tumors and mucosae were similar (1.2 ± 1.1 and 0.8 ± 0.9 pmol/mg protein, respectively; p = 0.1, NS). In relation to clinical stage and tumor size, a statistical difference was found in GSH and GST values between tumors and mucosae for stage IV and T3/T4. The increase in tumor TS compared to that of mucosae was significant for all clinical stages, tumor sizes, and nodal involvement. Conclusions. These data enhance our understanding of the enzymatic systems involved in cisplatin and 5-fluorouracil (5-FU) resistance in HNSCC and normal mucosae and may help to elucidate tumor behavior and interpatient differences in drug sensitivity. © 1994 John Wiley & Sons, Inc. 相似文献
98.
The research was designed to investigate the moderating effect of some personality traits on subjective distress caused by daily hassles. The traits were internal locus of control, repression, ego strength, and barrier (as studied and defined by S. Fisher). The last two variables were negatively correlated both with the somatic and emotional distress indications and with the frequency of hassles reportED; internal locus of control showed an inverse relationship only with frequency of hassles. The hypothesis is formulated that ego strength and barrier are personality factors influencing not only the outcomes of coping (ie the stress response), but also event appraisal. 相似文献
99.
Total ganglioside and sialoglycoprotein concentrations were determined in the hypothalamus of normal (diet: 25% casein), postnatal undernourished (diet: 8% casein since birth), and pre- and postnatal undernourished rats (diet: 8% casein since pregnancy). Hypothalamic weights for the two low protein diet groups were lower than for the normal diet groups at all ages studied. Total hypothalamic ganglioside and sialoglycoproteins (mumol NANA) of postnatal undernourished rats were lower than control at day 10, while in pre- and postnatal undernourished rats this difference occurred at day 7. The reduction in gangliosides and sialoglycoprotein contents was not solely a consequence of the decrease in hypothalamic weight since, when the data were expressed as nmol NANA/mg tissue, similar reductions were observed principally in the pre- and postnatal protein undernutrition group. These results suggest that the effects of pre- and postnatal undernutrition on hypothalamic gangliosides and sialoglycoproteins are more pronounced than those that occur as a result of postnatal undernutrition. 相似文献
100.
Hyperinfestation with Strongyloides is a severe complication in immunodepressed patients. It may present with various clinical signs, notably acute respiratory failure. Diagnosis may be difficult, particularly when the strongyloidiasis is associated with septicaemia caused by Gram-negative organisms. We report a new case of hyperinfestation with Strongyloides in a patient treated for periarteritis nodosa. This case was remarkable on two scores: the diagnosis problem raised by the presence of intrapulmonary haemorrhages, and the favourable outcome of an acute and initially severe respiratory failure which had required assisted ventilation. The role played in the patient's cure by the doses of thiabendazole given and the duration of their administration is discussed. 相似文献