全文获取类型
收费全文 | 706102篇 |
免费 | 48892篇 |
国内免费 | 1304篇 |
专业分类
耳鼻咽喉 | 9167篇 |
儿科学 | 23269篇 |
妇产科学 | 17609篇 |
基础医学 | 110423篇 |
口腔科学 | 19955篇 |
临床医学 | 63787篇 |
内科学 | 134349篇 |
皮肤病学 | 16159篇 |
神经病学 | 49508篇 |
特种医学 | 25753篇 |
外国民族医学 | 77篇 |
外科学 | 104514篇 |
综合类 | 14818篇 |
现状与发展 | 2篇 |
一般理论 | 160篇 |
预防医学 | 51394篇 |
眼科学 | 16320篇 |
药学 | 53995篇 |
3篇 | |
中国医学 | 2359篇 |
肿瘤学 | 42677篇 |
出版年
2019年 | 5437篇 |
2018年 | 7863篇 |
2017年 | 6112篇 |
2016年 | 6819篇 |
2015年 | 7553篇 |
2014年 | 10264篇 |
2013年 | 15384篇 |
2012年 | 20502篇 |
2011年 | 21500篇 |
2010年 | 12726篇 |
2009年 | 11938篇 |
2008年 | 20002篇 |
2007年 | 21517篇 |
2006年 | 21914篇 |
2005年 | 20450篇 |
2004年 | 20010篇 |
2003年 | 18949篇 |
2002年 | 18465篇 |
2001年 | 36337篇 |
2000年 | 36904篇 |
1999年 | 30396篇 |
1998年 | 7879篇 |
1997年 | 6667篇 |
1996年 | 6973篇 |
1995年 | 6631篇 |
1994年 | 6100篇 |
1993年 | 5595篇 |
1992年 | 22983篇 |
1991年 | 22934篇 |
1990年 | 22321篇 |
1989年 | 22086篇 |
1988年 | 20044篇 |
1987年 | 19420篇 |
1986年 | 18472篇 |
1985年 | 17310篇 |
1984年 | 12701篇 |
1983年 | 10742篇 |
1982年 | 5921篇 |
1979年 | 11519篇 |
1978年 | 8128篇 |
1977年 | 6832篇 |
1976年 | 6595篇 |
1975年 | 7268篇 |
1974年 | 8498篇 |
1973年 | 8141篇 |
1972年 | 7659篇 |
1971年 | 7128篇 |
1970年 | 6878篇 |
1969年 | 6306篇 |
1968年 | 5781篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
N N Sliusar' A V Kargapolov V Ia Vasiutkov 《Klinichna khirurhiia / Ministerstvo okhorony zdorov'ia Ukra?ny, Naukove tovarystvo khirurhiv Ukra?ny》1990,(5):21-22
In patients with gastric cancer, the content of phosphatidylinositols in the blood was significantly decreased, in average 2-fold, as compared with their level in donors. After surgical treatment in 36 patients, these indices increased and achieved a maximum value in a year. In these patients, the general state improved, there were no disease recurrences. In 44 patients after the operation, the content of phosphatidylinositols remained low, or increased insignificantly as compared with their level before the operation. In this group, 16 patients died, 10 developed a disease recurrency. 相似文献
72.
D A Evans B N Hamid E M Hoare 《Journal of the Royal College of Surgeons of Edinburgh》1990,35(1):33-35
Thirteen cases of primary appendicular adenocarcinoma are reported. This rare tumour usually presents as acute appendicitis. The correct diagnosis is rarely entertained before or during surgery. The main treatment choice lies between appendicectomy alone and appendicectomy followed by right hemicolectomy. There are anatomical reasons for advising the latter and survival figures from the literature tend to support this preference. The cases reported here indicate that in the period 1972-1984, in the North West Region, there was a slight preference for appendicectomy alone. The additional procedure of right hemicolectomy did not confer any clear-cut survival advantage. 相似文献
73.
Absorption mechanism and absorption site of a prodrug of L-DOPA, L-3-(3-hydroxy-4-pivaloyloxyphenyl)alanine (NB-355, 1) was investigated using rats. Prodrug 1 (0.5 mM) was taken up by intestinal tissue segments time-dependently in vitro at pH 6.0. However, the rate of uptake was less than that of L-dopa. Inhibitors of the amino acid active transport system (L-Phe, dinitrophenol, ouabain) had no effect on the uptake of prodrug 1. In the intestinal tissue segments, prodrug 1 was extensively hydrolyzed by diisopropylfluorophosphate-sensitive esterase(s). To characterize the absorption site, gastrointestinal tracts were ligated to make acute loops in situ and prodrug 1 or L-dopa was injected into the loops. L-dopa disappeared rapidly from the lumen of the jejunum. In contrast, prodrug 1 disappeared rapidly from the ileum rather than the duodenum or jejunum. From these results, it was suggested that prodrug 1 was slowly absorbed primarily from the lower small intestine. 相似文献
74.
75.
76.
Summary A case of bilateral congenital pseudarthrosis of the clavicle in a baby boy is described. The patient is fully asymptomatic, and no functional impairment is present. This is probably only the seventh case described of this rare congenital anomaly. 相似文献
77.
P Rubinstein M Walker N Mollen C Carpenter S Beckerman N Suciu-Foca R McEvoy F Ginsberg-Fellner 《Diabetes》1990,39(9):1138-1143
The gene frequencies, haplotype relative risks, and zygotic assortments of HLA-DR in three ethnically defined samples of insulin-dependent diabetes mellitus (IDDM) patients were determined in a prospective family study. Although DR3 and DR4 were positively associated with IDDM in the probands of 123 northern European, 94 Ashkenazi Jewish, and 49 New York Hispanic families, significant excess of DR*3/4 heterozygotes was observed only among the probands from families of northern European ancestry. There was also a significant decrease in the frequency of Bw62,DR4 haplotypes derived by northern European patients from their mothers compared with their fathers. This difference, together with data reported in the literature, suggests that the expressivity of the susceptible genotype(s) in IDDM patients may be modified by protective maternal effects associated with Bw62,DR4 and probably other DR4 haplotypes. Samples of IDDM patients from populations with high frequencies of these modifiers should have different DR-gene frequencies contributed by fathers and mothers, capable of accounting for the observed Hardy-Weinberg disequilibrium. We postulate that, because the mechanism of action of these modifiers is distinct from that of the susceptibility gene, the difference must be considered in devising strategies for elucidation of the mode of inheritance of the disease and for understanding the molecular nature of the susceptibility. 相似文献
78.
T Abumiya I Sayama K Asakura H Hadeishi M Mizuno A Suzuki N Yasui F Shishido K Uemura 《No shinkei geka. Neurological surgery》1990,18(9):837-844
Regional effects of craniotomy on cerebral circulation and metabolism, such as regional cerebral blood flow (rCBF), regional cerebral oxygen consumption (rCMRO2), regional oxygen extraction fraction (rOEF), and regional cerebral blood volume (rCBV) were examined by a PET (positron emission tomography) study concerning surgery that was performed on unruptured aneurysm patients. Eight patients with intracranial un-ruptured aneurysms were studied pre- and post-operatively by the 15O labelled-gas steady-state method, using HEADTOME-III. All patients underwent aneurysmal surgery performed by the transsylvian approach. There was a significant increase in the mean OEF values taken from the whole-brains of 8 patients, but there was not a significant change in CBF, CMRO2 or CBV. The increase in OEF was caused by decrease of O2 content, which was caused by post-operative decrease in the Hb value. So, this OEF increase was not the direct effect of craniotomy. In 2 patients, the rCBF and rCMRO2, in the fronto-temporal region (where craniotomy was performed) increased post-operatively. This regional effect suggests transient reactive hyperemia following compressive ischemia during the operative procedure, and metabolic demands for recovery of brain function. In 2 other patients, who had relatively low rCBFs during the pre-operative study, rCBF and rCMRO2 in the bi-frontal region had decreased more at the post-operative study. This change appears to have been caused by removal of cerebrospinal fluid and depression of the frontal lobe. From this study, it becomes evident that the regional effect of craniotomy on cerebral circulation and metabolism is not so great, when adequate microsurgical techniques are used. 相似文献
79.
80.
Ch. Lenzen N. Roewer F. Wappler A. Köchling M. Steinfath J. Sgholz J. Schulte am Esch 《Acta anaesthesiologica Scandinavica》1995,39(3):343-346
Dantrolene seems to be the causal therapy in malignant hyperthermia (MH) crisis but the complex mechanisms of MH and dantrolene therapy are still not fully understood. The influence of dantrolene on ryanodine-induced contractures has been reported in animal studies only. In the present study 20 patients from] 7 families were tested for MH using the protocol of the European Malignant Hyperthermia Group. In addition ryanodine-induced contractures were evaluated following bolus application of 10.0 μmol · 1-1 ryanodine. After pretreatment with 1 μimol · 1-1 dantrolene ryanodine-provoked contractures developed significantly later in MHS (15.8±1.8 min) and MHN (46.0±4.2 min) muscle specimens than after ryanodine alone (MHS 4.8±0.7 min), (MHN 13.7±0.9 min). They were no longer observed in either group after pretreatment with 5 μimol · 1-1 dantrolene. We conclude that dantrolene is able to attenuate ryanodine-induced contractures dose-dependendy, and therefore it is speculated that dantrolene could specifically act at the ryanodine receptor binding site. 相似文献