全文获取类型
收费全文 | 1489541篇 |
免费 | 98841篇 |
国内免费 | 3315篇 |
专业分类
耳鼻咽喉 | 21888篇 |
儿科学 | 46042篇 |
妇产科学 | 43377篇 |
基础医学 | 207566篇 |
口腔科学 | 44631篇 |
临床医学 | 124774篇 |
内科学 | 289329篇 |
皮肤病学 | 33700篇 |
神经病学 | 115315篇 |
特种医学 | 62396篇 |
外国民族医学 | 517篇 |
外科学 | 231637篇 |
综合类 | 31981篇 |
现状与发展 | 6篇 |
一般理论 | 437篇 |
预防医学 | 105928篇 |
眼科学 | 34948篇 |
药学 | 110496篇 |
5篇 | |
中国医学 | 3110篇 |
肿瘤学 | 83614篇 |
出版年
2018年 | 14938篇 |
2017年 | 13119篇 |
2016年 | 13449篇 |
2015年 | 16234篇 |
2014年 | 20454篇 |
2013年 | 28133篇 |
2012年 | 41470篇 |
2011年 | 38799篇 |
2010年 | 22568篇 |
2009年 | 23517篇 |
2008年 | 35225篇 |
2007年 | 38922篇 |
2006年 | 39704篇 |
2005年 | 45983篇 |
2004年 | 46481篇 |
2003年 | 41326篇 |
2002年 | 36374篇 |
2001年 | 66460篇 |
2000年 | 66443篇 |
1999年 | 59230篇 |
1998年 | 15037篇 |
1997年 | 13639篇 |
1996年 | 13174篇 |
1995年 | 12463篇 |
1992年 | 47568篇 |
1991年 | 46372篇 |
1990年 | 45868篇 |
1989年 | 44624篇 |
1988年 | 41639篇 |
1987年 | 41057篇 |
1986年 | 39304篇 |
1985年 | 36991篇 |
1984年 | 27515篇 |
1983年 | 23215篇 |
1982年 | 13407篇 |
1981年 | 12151篇 |
1979年 | 26821篇 |
1978年 | 18863篇 |
1977年 | 16154篇 |
1976年 | 14616篇 |
1975年 | 17167篇 |
1974年 | 20548篇 |
1973年 | 19747篇 |
1972年 | 18953篇 |
1971年 | 17967篇 |
1970年 | 17001篇 |
1969年 | 16360篇 |
1968年 | 15329篇 |
1967年 | 13837篇 |
1966年 | 12889篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
931.
To evaluate the relative contribution of insulin binding and postbinding defects of glucose utilization in peripheral tissue during normal and diabetic pregnancy, we have studied the in vitro insulin action of isolated adipocytes from eight nondiabetic pregnant women and nine pregnant women with insulin-dependent diabetes mellitus who were undergoing cesarian section. The pregnant women were compared with a matched group of normal nonpregnant women undergoing gynecologic surgery. Insulin binding to adipocytes measured at tracer insulin concentration was reduced by 45% (P less than 0.01) in normal pregnant women and by 30% (P less than 0.02) in pregnant women with diabetes. In contrast, no changes were found between the three groups in insulin binding to pure monocytes and erythrocytes. The glucose transport system in fat cells from both groups of pregnant women was characterized by impaired maximal (P less than 0.05) and half-maximal (P less than 0.05) response to insulin. When fat cell glucose metabolism was studied, pregnant diabetic women exhibited decreased basal lipogenesis (P less than 0.05) and decreased maximal responses of lipogenesis and glucose oxidation to insulin stimulation (P less than 0.05). Similar but less pronounced abnormalities were seen in glucose metabolism of adipocytes from nondiabetic pregnant women. In conclusion, both in late normal and diabetic pregnancy, insulin binding to adipocytes is significantly reduced and accompanied by decreased insulin sensitivity and reduced maximal insulin responsiveness of glucose transport and by impaired basal and maximally insulin-stimulated glucose metabolism. 相似文献
932.
933.
S. Ahmed A. L. Sparnon J. P. Savage H. A. Boucaut A. J. Smith 《ANZ journal of surgery》1986,56(9):675-680
One hundred and one children over 1 year of age have had surgery for pelviureteric obstruction over an 11 year period. The common clinical features were abdominal pain, urinary infection or haematuria, but number presented as an incidental finding. Less commonly, the patients presented with an abdominal mass or with hypertension. The diagnosis was usually made on intravenous pyelography (IVP) but in the latter part of the series, renal nuclide scan (RNS) and ultrasonography (US) were preferred. Ninety–three patients had unilateral pyeloplasty, three had bilateral pyeloplasty and five had nephrectomy or heminephrectomy. Whereas initially nephrostomy drainage was used in the majority of patients after pyeloplasty, trend away from nephrostomy evolved in the latter part of the series. With experience, the incidence of postoperative complications was also reduced and there was reduction in the period of hospitalization. Clinical results were consistently satisfactory. Postoperative assessment after pyeloplasty was made by IVP and/or RNS and also US. A review of these investigations showed that RNS provided more factual information of the result when compared with the IVP. 相似文献
934.
935.
Ovarian and omental ependymomas in peritoneal washings: cytologic and immunocytochemical features 总被引:1,自引:0,他引:1
The cytologic findings in peritoneal washings of two women, one of whom had an ovarian ependymoma and the other a primary omental ependymoma, are reported. The ependymomas were characterized by the presence of numerous, isolated, spindle and stellate cells as well as groups of cells forming true rosettes. The tumor cells displayed slightly pleomorphic, round-to-oval eccentric nuclei and abundant fibrillary cytoplasm with tapering cytoplasmic processes. In addition, one of the patients had numerous papillae and cell clusters with associated psammoma bodies indistinguishable from those found in low-grade serous carcinoma. The demonstration of glial fibrillary acidic protein (GFAP) in both cases by immunocytochemical procedures indicates the usefulness of this method in cytologic preparations to confirm the diagnosis of these uncommon neoplasms. 相似文献
936.
937.
J B Wilson R N Wrightstone T H Huisman 《The Journal of laboratory and clinical medicine》1986,108(2):138-141
A rapid method for separating and quantitating hemoglobin (Hb) variants in cord blood samples using cation high-performance liquid chromatography (HPLC) is described. The procedure is a modification of a previously published method, and uses a weak cation-exchange Brownlee-3CM column and Bis-Tris-KCN-Na acetate developers. A chromatogram can be completed in 10 minutes. The slow-moving variants, Hbs S, C, and O Arab, can be completely separated from each other and are identified by their elution times relative to Hb A. Hb E elutes as a shoulder on the descending side of Hb A, which is characteristic for this variant in this procedure. Differentiation between heterozygous, homozygous, and Hb X-beta+-thalassemia conditions is easily made. 相似文献
938.
939.
Y Abiko K Ichihara K Sakai H Sashida T Ishibashi 《Methods and findings in experimental and clinical pharmacology》1986,8(5):271-278
This paper describes a method by which antianginal drugs can be evaluated in the dog heart in situ. Myocardial pH was measured continuously by a micro glass pH electrode inserted in the left ventricular endocardial layers of the dog anesthetized with pentobarbital. Occlusion of the left anterior descending coronary artery (LAD) decreased myocardial pH, and release of the LAD restored the pH. The myocardial acidosis induced by ischemia was metabolic in nature and accompanied by a decrease in the levels of adenosine triphosphate and creatine phosphate and an increase in the levels of lactate in the myocardium. Drugs were injected intravenously 30 min after incomplete (partial) occlusion ot the LAD, lasting until 60 min after drug injection. Propranolol, atenolol, and sotalol markedly attenuated the myocardial pH that had been decreased by LAD occlusion. Nitroglycerin, diltiazem, and nicorandil also attenuated the pH, but these drugs were less active in attenuating myocardial acidosis. Dipyridamole, nifedipine, and beta-2 adrenoceptor antagonists were least active in this regard. It is concluded that myocardial pH can be used as an indicator of myocardial regional ischemia and utilized for evaluation of antianginal drugs. 相似文献
940.
Previous field and laboratory studies have revealed that there is a diurnal variation in subjective sleepiness that is different in form to that of objective sleepiness and many measures of performance efficiency. The worst subjective sleepiness occurs at the trough in the circadian temperature rhythm, the least subjective sleepiness about 7 h before the peak in temperature. A series of forced desynchronization experiments, in which the endogenous circadian oscillator controlling the temperature rhythm ran at a different period to the sleep/wake cycle, revealed that these findings can be explained by postulating subjective sleepiness to be under the control of both factors, with minimum sleepiness occurring at the peak in temperature in terms of the temperature cycle and about 6 h after waking in terms of the sleep/wake cycle. 相似文献