全文获取类型
收费全文 | 1225683篇 |
免费 | 92693篇 |
国内免费 | 4596篇 |
专业分类
耳鼻咽喉 | 18123篇 |
儿科学 | 32386篇 |
妇产科学 | 34441篇 |
基础医学 | 174247篇 |
口腔科学 | 36747篇 |
临床医学 | 104029篇 |
内科学 | 240044篇 |
皮肤病学 | 25502篇 |
神经病学 | 96193篇 |
特种医学 | 48863篇 |
外国民族医学 | 253篇 |
外科学 | 193961篇 |
综合类 | 33294篇 |
现状与发展 | 2篇 |
一般理论 | 331篇 |
预防医学 | 83444篇 |
眼科学 | 29908篇 |
药学 | 94642篇 |
1篇 | |
中国医学 | 3746篇 |
肿瘤学 | 72815篇 |
出版年
2018年 | 11913篇 |
2016年 | 10296篇 |
2015年 | 12124篇 |
2014年 | 17128篇 |
2013年 | 24494篇 |
2012年 | 33373篇 |
2011年 | 34664篇 |
2010年 | 20470篇 |
2009年 | 19191篇 |
2008年 | 32142篇 |
2007年 | 34789篇 |
2006年 | 34512篇 |
2005年 | 33323篇 |
2004年 | 32298篇 |
2003年 | 31177篇 |
2002年 | 29949篇 |
2001年 | 60609篇 |
2000年 | 61939篇 |
1999年 | 52093篇 |
1998年 | 13955篇 |
1997年 | 12438篇 |
1996年 | 11984篇 |
1995年 | 11191篇 |
1994年 | 10518篇 |
1993年 | 9783篇 |
1992年 | 41407篇 |
1991年 | 39783篇 |
1990年 | 38745篇 |
1989年 | 37711篇 |
1988年 | 34949篇 |
1987年 | 34152篇 |
1986年 | 32145篇 |
1985年 | 30827篇 |
1984年 | 22897篇 |
1983年 | 19329篇 |
1982年 | 11405篇 |
1981年 | 10282篇 |
1979年 | 21963篇 |
1978年 | 15314篇 |
1977年 | 13031篇 |
1976年 | 11475篇 |
1975年 | 12669篇 |
1974年 | 15547篇 |
1973年 | 14851篇 |
1972年 | 14244篇 |
1971年 | 13353篇 |
1970年 | 12642篇 |
1969年 | 12354篇 |
1968年 | 11041篇 |
1967年 | 10096篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
A new range of stand magnifiers has been released by the COIL company in the United Kingdom. Examination of these magnifiers reveals that they fail to deliver the rated magnifications labelled prominently on the appliances, as a result of the manufacturer's conformance with the requirements of the German DIN standard and the use of back vertex power (F'v) rather than equivalent dioptric power (Fm) of the magnifier. In this study we provide information on the optometric parameters of these new stand magnifiers that will assist the more accurate specification of improvements in vision expected from their use. 相似文献
82.
W. F. S. Sellers 《Anaesthesia》1996,51(5):513-513
83.
W Lees 《Ultrasound in obstetrics & gynecology》1993,3(3):162-163
An ultrasound contrast agent which survives transit through the pulmonary circulation after injection into a peripheral vein can also be used for the demonstration of flow characteristics in the peripheral organs. Such a substance (SH U 508 A, Schering AG, Berlin) was tested in the Gynecological Department of the University of Marburg for its suitability for enhancing color-coded Doppler signals in mammary diagnosis in a group of ten women with breast tumors. The observations made are compared with the histologically confirmed diagnoses. The very distinct enhancement of the color-coded Doppler signals allows reliable demonstration of the vascularization characteristics, not only of the malignant, but also of all benign solid tumors examined. Color signals were even recorded from normal mammary tissue, which means that the demonstration of perfusion can no longer be used on its own as a diagnostic criterion. Observation of the characteristics of the blood supply to a tumor might, on the other hand, be an advantage, not only in respect of tumor typing, but also as regards the prognosis of a tumor. In this connection, the registration of the arrival, retention and wash-out phases specific to a contrast agent appears to furnish particularly interesting information about the growth dynamics of a tumor. 相似文献
84.
85.
W. Hughes A. Barr B. C. Dow† E. A. C. Follett † J. A. J. Barbara‡ 《Transfusion medicine (Oxford, England)》1995,5(3):225-230
SUMMARY. Samples from 1828 donations were screened for anti-HBc at seven sites in the UK using kits supplied by 10 manufacturers. Only 10 (0.55%) donations were considered to have true anti-HBc reactivity and these were detected by all 10 kits. Additional markers of HBV infection were found in nine of these 10 donations. Additional reactives were found by all kits, the number ranging from 1 to 43.
In the four more specific kits, the 10 true reactives were clearly distinguished from the 'false reactives' by the strength of the reaction. It is concluded that the reliance on a single ELISA test for anti-HBc diagnosis is unwise. The use of a second test known to be more specific than the screening ELISA is recommended. 相似文献
In the four more specific kits, the 10 true reactives were clearly distinguished from the 'false reactives' by the strength of the reaction. It is concluded that the reliance on a single ELISA test for anti-HBc diagnosis is unwise. The use of a second test known to be more specific than the screening ELISA is recommended. 相似文献
86.
87.
T Oda N Yoshizawa S Oshima A Takeuchi T Kubota S Kondo Y Oshikawa Y Akashi Y Suzuki H Niwa 《Nihon Jinzo Gakkai shi》1990,32(6):631-641
To investigate the role of cell-mediated immunity (CMI) in glomerulonephritis (GN), we identified the infiltrating immune cells both within the glomerulus and in the interstitium. Frozen sections from 103 patients with various forms of GN: 10 with minor glomerular abnormality (MGA) as control, 10 with minimal change nephrotic syndrome (MCNS), 10 with membranous nephropathy (MN), 9 with focal glomerulosclerosis (FGS), 30 with IgA nephropathy (IgAN), 22 with acute post streptococcal glomerulonephritis (APSGN), and 2 with rapidly progressive glomerulonephritis (RPGN) were examined using monoclonal antibodies (MoAb) by indirect immunoalkaline-phosphatase labelling. In most glomerulonephritis, monocyte/M phi and helper/inducer T cells were predominantly infiltrating in the interstitium, but intraglomerular infiltration was rare, except for APSGN. This interstitial infiltration increased proportionally to the level of serum creatinine, and was most prominent in RPGN. Apparently different distribution was seen in APSGN, that is, prominent increase in total number of intra-glomerular monocyte/M phi infiltration with slightly increased T cells. The change was correlated with time after onset; namely the more leucocytic infiltration was observed when the tissue was taken earlier. These data suggest that in APSGN, monocyte/M phi accumulate in glomeruli via cell mediated immunity in addition to humoral immune mechanism resulting in glomerular hypercellularity, whereas in most chronic glomerulonephritis interstitial leucocyte infiltration, particularly helper T cells and monocyte/M phi may play an important role in the progression of glomerulonephritis. 相似文献
88.
PCP and related compounds inhibit 3H-mazindol binding to the cocaine receptor on dopamine transporters. The relative potencies of these compounds are such that some of the behavioral effects of PCP could be related to its action at the cocaine receptor; however, the affinity of PCP at the cocaine site (Ki = 1.59 microM) is less than its affinity at its own receptor (Ki about 0.12 microM). More data will be needed to conclusively implicate the cocaine receptor in the action of PCP. 相似文献
89.
H Murakami M Togawa S Takahashi N Kasahara J Yamamoto N Matsuura Y Koshiyama Y Ino M Oda 《Arzneimittel-Forschung》1990,40(12):1352-1358
The effects of FUT-187 (6-amidino-2-naphthyl 4-[(4,5-dihydro-1H-imidazol-2-yl)amino]benzoate dimethanesulfonate, CAS 103926-82-5), a novel synthetic protease inhibitor, were examined in experimental rat and canine models of pancreatitis. 1. FUT-187 significantly increased the survival of rats with trypsin- and phospholipase A2-induced pancreatitis in a dose-dependent manner (10-100 mg/kg, p.o.). 2. FUT-187 decreased plasma enzymatic activity reflecting the degree of pancreatitis in rats with ethionine-induced pancreatitis, and showed a tendency to ameliorate histopathological changes in the pancreas (10-100 mg/kg p.o.). 3. FUT-187 (10 mg/kg) produced an obvious improvement of various biochemical parameters of pancreatitis and also reduced histopathological changes in the pancreas in animals with experimental pancreatitis produced by the closed duodenal loop method. In addition, FUT-187 significantly increased the survival of dogs when given by direct administration into the lumen of the closed duodenal loop. The therapeutic effects of FUT-187 in experimental pancreatitis were nearly equal in most instances to those of camostat mesilate. Thus, FUT-187 would appear to be an effective new agent for the treatment of pancreatitis. 相似文献
90.