全文获取类型
收费全文 | 13137篇 |
免费 | 768篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 145篇 |
儿科学 | 318篇 |
妇产科学 | 177篇 |
基础医学 | 1763篇 |
口腔科学 | 270篇 |
临床医学 | 1715篇 |
内科学 | 2859篇 |
皮肤病学 | 123篇 |
神经病学 | 1139篇 |
特种医学 | 557篇 |
外科学 | 1689篇 |
综合类 | 66篇 |
一般理论 | 5篇 |
预防医学 | 1086篇 |
眼科学 | 147篇 |
药学 | 908篇 |
中国医学 | 14篇 |
肿瘤学 | 961篇 |
出版年
2023年 | 87篇 |
2022年 | 154篇 |
2021年 | 262篇 |
2020年 | 188篇 |
2019年 | 309篇 |
2018年 | 345篇 |
2017年 | 258篇 |
2016年 | 299篇 |
2015年 | 353篇 |
2014年 | 473篇 |
2013年 | 686篇 |
2012年 | 1062篇 |
2011年 | 1063篇 |
2010年 | 607篇 |
2009年 | 547篇 |
2008年 | 831篇 |
2007年 | 939篇 |
2006年 | 834篇 |
2005年 | 882篇 |
2004年 | 741篇 |
2003年 | 623篇 |
2002年 | 659篇 |
2001年 | 101篇 |
2000年 | 77篇 |
1999年 | 103篇 |
1998年 | 157篇 |
1997年 | 124篇 |
1996年 | 114篇 |
1995年 | 105篇 |
1994年 | 87篇 |
1993年 | 72篇 |
1992年 | 67篇 |
1991年 | 59篇 |
1990年 | 44篇 |
1989年 | 49篇 |
1988年 | 42篇 |
1987年 | 20篇 |
1986年 | 25篇 |
1985年 | 39篇 |
1984年 | 35篇 |
1983年 | 39篇 |
1982年 | 39篇 |
1981年 | 24篇 |
1980年 | 26篇 |
1978年 | 20篇 |
1977年 | 18篇 |
1974年 | 23篇 |
1972年 | 16篇 |
1971年 | 16篇 |
1970年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Martine Visser Johan Marinus Anne M Stiggelbout Jacobus J Van Hilten 《Movement disorders》2004,19(11):1306-1312
We developed a questionnaire to assess autonomic symptoms in patients with Parkinson's disease (PD) and evaluated its reliability and validity. Based on the results of a postal survey in 46 PD patients, 21 multiple system atrophy patients, and 8 movement disorders specialists, items were included according to their frequency, burden, and clinical relevance. The questionnaire was evaluated in 140 PD patients and 100 controls, and test-retest reliability was established in a sample of 55 PD patients. The SCOPA-AUT consists of 25 items assessing the following regions: gastrointestinal (7), urinary (6), cardiovascular (3), thermoregulatory (4), pupillomotor (1), and sexual (2 items for men and 2 items for women) dysfunction. Test-retest reliability was good. Autonomic problems increased significantly with increasing disease severity for all autonomic regions, except sexual dysfunction. We conclude that SCOPA-AUT is a reliable and valid questionnaire that evaluates autonomic dysfunction in PD. 相似文献
22.
Gsta Berlin Aril Frydn Rolf Maller Claes Malm Olle Vikrot 《European journal of haematology》1981,25(2):171-174
At our hospital 15 cases of leukaemic reticuloendotheliosis and 4 cases of Legionnaires' disease have been diagnosed. 3 patients had both diseases. The clinical findings are reported. It is probable that patients with leukaemic reticuloendotheliosis have an increased susceptibility to Legionnaires' disease. Possible reasons for the decreased resistance are discussed. 相似文献
23.
Johan Åkerstedt 《Parasitology research》2002,89(1):49-52
Encephalitozoon cuniculi, a microsporidian parasite of vertebrates, is considered a health risk to AIDS patients and other immunocompromised human beings. In most hosts, infection with the parasite runs a subclinical course. In some carnivore species, however, clinical disease affecting whole litters arises from intrauterine transmission of the parasite. In both blue foxes (Alopex lagpus) and dogs (Canis familiaris), outbreaks of encephalitozoonosis can be severe. Canine encephalitooonosis has been reported from various parts of the world, including South Africa and the United States. In Norway, there have been large outbreaks of the disease in blue fox farms, affecting also mink, but there have been no reports of encephalitozoonosis in dogs. Infection in dogs would represent a zoonotic problem, due to the close social relationship between dog and man. The purpose of the present study was to investigate the possible occurrence of E. cuniculi infection in Norwegian dogs by serological methods. In the study, 1,104 canine serum samples, originally submitted for biochemical analysis by veterinary practitioners throughout Norway, were screened by enzyme-linked immunosorbent assay for antibodies to E. cuniculi. Samples from 237 of the dogs were tested also by the indirect fluorescent antibody test. All samples were concluded as negative. The results indicate that the likelihood of occurrence of E. cuniculi infection in Norwegian dogs is small. 相似文献
24.
Mark F. Cotton Peter R. Donald Johan F. Schoeman Lana E. Van Zyl Cor Aalbers Carl J. Lombard 《Child's nervous system》1993,9(1):10-15
Intracranial pressure (ICP) monitored shortly after admission over a period of 1 h in 31 children with tuberculous meningitis (TBM) was significantly higher (median 22.5 mm Hg, range 8.4–50.9 mmHg) in 19 children with laboratory evidence of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) than in 12 children without such evidence (median 16.2 mmHg, range 5.8–42.5 mmHg; P = 0.027). Neither plasma nor cerebrospinal fluid arginine vasopressin (AVP) was related to ICP (r = 0.33 and 0.13 respectively). Mean arterial pressure (MAP) was measured in 23 children and a moderate correlation was found with plasma AVP (r = 0.62; P = 0.0019). In TBM, plasma AVP may be secreted as a response to raised ICP in an effort to raise MAP and maintain cerebral perfusion pressure. In this setting excess fluid may be inappropriately retained, leading to hyponatremia and hypo-osmolemia. 相似文献
25.
Bradley R Pieters Johan N B van der Grient Leo E C M Blank Kees Koedooder Maarten C C M Hulshof Theo M de Reijke 《Radiotherapy and oncology》2006,80(1):69-72
Catheters were developed that can be fixed in the prostate gland by self-expanding parts for use in PDR brachytherapy. Daily CT-scans were made to investigate the magnitude of catheter displacement. The mean absolute displacement during the 3 day treatment was 1.2 mm. The resulting minor alterations in dose-volume parameters were of no clinical importance. 相似文献
26.
Sequence specificity of mutation induced by the anti-tumor drug cisplatin in the CHO aprt gene 总被引:5,自引:0,他引:5
Cis-diammine dichloroplatinum (cisplatin) is an effective anticancerdrug which forms adducts with DNA, in both bacterial and mammaliancells. It is suspected of producing tumors as well. To determinethe molecular nature of geneti alterations induced by cisplatin,we cloned and sequenced cisplatin-induced mutants in the adeninephosphoribosyl-transferase (aprt) gene of Cinese hamster ovary(CHO) cells. Mutation by cisplatin appears to be targeted asthe sites of mutation are consistent with the known bindingspecificity of cisplatin. Many mutations occur at or proximalto the sequence 5'-AGG-3' and 5'-GAG-3' and include transversions,transitions, frameshifts and short deletions and duplications.Several double changes were also observed. No major rearrangementswere recovered in our collection. At several locations, a numberof mutants were found to be clustered within a small targetregion, but unlike traditional hotspots, tese represent diversechanges occurring in a localized region of a few base pairs. 相似文献
27.
28.
Johannes M. A. Van Gerven Johan P. Boot Herman H. P. J. Lemkes Jaap A. Van Best PhD 《Documenta ophthalmologica. Advances in ophthalmology》1992,80(2):183-188
The morphological base for the impaired function of the blood retinal barrier was studied in 50 eyes of 10 insulin dependent and 21 non-insulin dependent patients with various levels of diabetic retinopathy. The permeability of the blood retinal barrier (PBRB) was determined by vitreous fluorophotometry with correction for autofluorescence, lenstransmission and non-protein bound plasma fluorescein concentration. Morphological abnormalities of diabetic retinopathy assessed by fundus photography and fluorescein angiography were individually scored on a decimal scale and related to the PBRB by multiple regression analysis. The Pbrb was not correlated to morphological abnormalities of non-proliferative retinopathy [(1) microaneurysms, (2) hard exudates, (3) soft exudates, (4) intraretinal hemorrhages, (5) fluorescein leakage, and (6) capillary closure, p > 0.3]. The PBRB was correlated to morphological abnormalities of (pre)proliferative retinopathy [(1) intraretinal microvascular abnormalities (Sirma) and (2) new vessels (Sneo): pbrb = A – B.SIRMA – C.Sneo with PBRB in nm/sec, A = 1.5 ± 0.5, B = 0.9 ± 0.2 and C = 1.7 ± 0.4, R2 = 0.65, p < 0.0001]. It can be concluded that the increased blood retinal barrier permeability in diabetic patients is mainly due to (pre)proliferative abnormalities and not to non-proliferative abnormalities. 相似文献
29.
30.
Raymer P. Grant Cliff Morgan Michael S. Page David N. Malm Victor Huckel Leonard C. Jenkins 《Journal canadien d'anesthésie》1990,37(4):409-415
Dipyridamole thallium scanning (DTS) is an imaging technique with good sensitivity for coronary artery disease (CAD). The purpose of this study was to compare the haemodynamic courses and the correlation between pulmonary capillary wedge pressure (PCWP) and central venous pressure (CVP) in patients with normal DTS (Group 1: n = 12) with those whose scans demonstrated CAD (Group2: n = 11). Haemodynamic profiles were obtained prior to anaesthesia and at several times during surgery. The haemodynamic courses in both groups were similar with significant decreases in cardiac index, stroke index, and left ventricular stroke work index during aortic cross-clamping compared with values prior to anaesthesia. There were no significant changes in PCWP and CVP throughout the study. The correlations between PCWP and CVP were significant in both groups as were the correlations between the changes in PCWP and the changes in CVP observed at the time of cross-clamping. These correlations all had large standard errors of the estimate, however, making it impossible to predict the PCWP from the CVP with precision. It is concluded that, in a limited study population, an abnormal DTS did not identify patients in whom the PCWP and CVP correlated poorly during abdominal aortic aneurysmectomy. 相似文献