全文获取类型
收费全文 | 8117篇 |
免费 | 591篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 62篇 |
儿科学 | 279篇 |
妇产科学 | 263篇 |
基础医学 | 1009篇 |
口腔科学 | 127篇 |
临床医学 | 1138篇 |
内科学 | 1408篇 |
皮肤病学 | 127篇 |
神经病学 | 737篇 |
特种医学 | 190篇 |
外科学 | 812篇 |
综合类 | 61篇 |
一般理论 | 16篇 |
预防医学 | 1104篇 |
眼科学 | 114篇 |
药学 | 602篇 |
中国医学 | 13篇 |
肿瘤学 | 667篇 |
出版年
2024年 | 23篇 |
2023年 | 113篇 |
2022年 | 124篇 |
2021年 | 230篇 |
2020年 | 198篇 |
2019年 | 244篇 |
2018年 | 257篇 |
2017年 | 211篇 |
2016年 | 258篇 |
2015年 | 253篇 |
2014年 | 309篇 |
2013年 | 462篇 |
2012年 | 660篇 |
2011年 | 732篇 |
2010年 | 361篇 |
2009年 | 295篇 |
2008年 | 550篇 |
2007年 | 536篇 |
2006年 | 535篇 |
2005年 | 491篇 |
2004年 | 368篇 |
2003年 | 404篇 |
2002年 | 355篇 |
2001年 | 69篇 |
2000年 | 41篇 |
1999年 | 60篇 |
1998年 | 64篇 |
1997年 | 45篇 |
1996年 | 46篇 |
1995年 | 35篇 |
1994年 | 41篇 |
1993年 | 31篇 |
1992年 | 36篇 |
1991年 | 16篇 |
1990年 | 29篇 |
1989年 | 20篇 |
1988年 | 15篇 |
1987年 | 14篇 |
1986年 | 18篇 |
1984年 | 9篇 |
1983年 | 16篇 |
1982年 | 14篇 |
1981年 | 13篇 |
1980年 | 9篇 |
1979年 | 15篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1975年 | 8篇 |
1974年 | 15篇 |
1973年 | 8篇 |
排序方式: 共有8729条查询结果,搜索用时 0 毫秒
11.
This paper reports the prevalence of chronic esophagitis and nutritional status among 538 young persons aged 15 to 26 years from the high risk area for esophageal cancer. Of these subjects, 166 were from households with history of esophageal cancer and 372 were from households without history of esophageal cancer. The Incidences of chronic esophagltis among male and female adolescents were 37. 6% and 36% respectively, which was significantly higher than those in the low risk area (17%). The frequency of chronic esophagltis in the adolescents in the households with history of esophageal cancer was aiso higher than in those In the households without history of esophageal cancer. The deficiencies of vitamins, especially of riboflavin and ascorbate, are prevalent and severe among these adolescents. Ascorbate deficiency Is correlated with the severity of the chronic esophagltis. These results indicate that chronic esophagltis may be involved in the natural history of esophageal carclnogenesis. Nutrient defic 相似文献
12.
13.
14.
Abstract: The development of a teaching package for nurse educators on drug and alcohol problems is described and the contents of its 16 modules outlined. 相似文献
15.
16.
Zvi Laron Jenny Frenkel lrit Gil-Ad Beatrice Klinger Ernesto Lubin Patrick Wuthrich François Boutignon Vincent Lengerts Romano Deghenghi 《Clinical endocrinology》1994,41(4):539-541
OBJECTIVE Hexarelin is a new synthetic growth hormone releasing peptide. We have tested the efficacy of intranasal (i.n.) administration of hexarelin to stimulate plasma GH and have compared this to the intravenous (i.v.) administration of the peptide. PATIENTS Ten children with familial short stature (FSS) aged 5·5-15·5 years and two known GH deficient patients aged 24 and 28 years without GH treatment. METHODS All 12 subjects were submitted to i.v. (1 μg/kg) and i.n. (20 μg/kg) hexarelin tests with a one-week interval between tests. Blood samples for GH, TSH, fT4 and T3 were obtained at 0, 15, 30, 60, 90 and 120 minutes. The hormone determinations were made by standard radio-immunoassays (RIA). RESULTS Both the i.n. and i.v. administration of hexarelin induced a large GH response, the mean (±SD) being 72·2± 35·5 mU/l for the i.n. test and 79·6 ± 53·0 mU/l for the i.v. test. The peak GH in the i.v. test occurred at 15–30 minutes and in the i.n. test between 30 and 60 minutes. The GH deficient patients showed no GH response In either test. Plasma TSH decreased in the FSS children from a mean (±SD) of 1.0 ± 0·26 to 0·64±0 2 mU/l (P<0 005) during the i.n. test and from 1·0±0·3 to 0·7±0·3mU/l (P> 0 05) during the I.v. test. In the isolated GH deficient patient, plasma TSH decreased from 1·06±0·38 mU/l to 0·86±0·17 during the i.v. test and from 1·60±0·01 to 1·11±0·06mU/l during the i.n. test. There were no significant changes in plasma fT4 or T3 in any of the tests. CONCLUSIONS The synthetic hexapeptide hexarelin is a potent pituitary GH stimulator when administered intra-nasally. The GH response was similar to that observed after intravenous hexarelin. Simultaneously, there was a significant decrease in plasma TSH but the concentrations remained in the normal range. These findings appear to be of theoretical and practical relevance to the investigation and management of short children. 相似文献
17.
Superior mesenteric vein thrombosis after splenectomy is very rare. In the case described of a patient presenting with acute abdominal pain the diagnosis was made primarily by real-time and Doppler ultrasonography. This reduced the time elapsing before it was recognized that angiography and subsequent thrombectomy were indicated. 相似文献
18.
J. -Y. Jenny G. Jenny J. Gaudias 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》1995,5(1):79-82
Summary 730 consecutive acute reamed intramedullary locked nailing of tibial fractures were studied, according to Gustilo’s classification
of soft tissue lesions for the open fractures. There is a significant increase of post-operative infection rate if the tibial
fracture is open, and the relative risk increases with the severity of soft tissue lesions. The comparison of these figures
with those of other methods of treatment and the mechanical and clinical advantages of nailing leads us to propose this method
for treatment of grade I, II and IIIa open fractures, while external the fixator seems better adapted for IIIb and c open
fractures.
European Bone and Joint Infection Society Meeting, München, Germany, October 7–9, 1993 相似文献
19.
Margrit Klingner Jenny Apelt Ashok Kumar Dietlind Sorger Osama Sabri J?rg Steinbach Matthias Scheunemann Reinhard Schliebs 《International journal of developmental neuroscience》2003,21(7):357-369
Cholinergic deficits in Alzheimer's disease are accompanied by a number of alterations in other transmitter systems including glutamate, noradrenaline and serotonin, suggesting the involvement also of other neurotransmitter systems in the pathogenesis of the disease. To address the question whether beta-amyloid may contribute to these deficits, brain tissue from transgenic Tg2576 mice with Alzheimer plaque pathology at ages of 5 (still no significant plaque load) and 17 months (moderate to high cortical beta-amyloid plaque load) were examined for a number of cholinergic and non-cholinergic markers. Transgenic mice with no significant plaque load demonstrated reduced hemicholinium-3 (HCh-3) binding to choline uptake sites in anterior brain regions as compared to non-transgenic littermates, while in aged transgenic mice with high number of plaque deposits decreased HCh-3 binding levels were accompanied by increased vesicular acetylcholine transporter binding in selected cortical brain regions. In aged transgenic mice GABA(A), NMDA, AMPA, kainate, and beta-adrenergic as well 5-HT(1A)- and 5-HT(2A)-receptor binding levels were hardly affected, whereas alpha(1)- and alpha(2)-adrenoceptor binding was increased in selected cerebral cortical regions as compared to non-transgenic littermates. The development of changes in both cholinergic and non-cholinergic markers in transgenic Tg2576 mouse brain already before the onset of progressive plaque deposition provides in vivo evidence of a modulatory role of soluble beta-amyloid on cortical neurotransmission and may be referred to the deficits in learning and memory observed in these mice also before significant plaque load. 相似文献
20.
Cross-linking induced interactions between the membrane form of immunoglobulin (mIg) and the cytoskeletal matrix have been described by several groups. To date, the function of mIgM association with the cytoskeleton is not yet understood. Delineation of the molecular basis of these interactions will be instrumental in elucidating their function. We have previously shown that the Igα/β heterodimer is not required for ligand-induced mIgM binding to the cytoskeleton. In this study, we have investigated the role of other B cell-specific proteins in mediating these interactions. For this, we expressed mIgM in the non-hematopoietic human cervical carcinoma cell line HeLa S3 and verified the capacity of the surface-expressed IgM to interact with the cytoskeletal matrix upon cross-linking with anti-μ chain antibodies. We show here that only the mIgM molecule itself and no other B cell-specific protein(s) is required in mediating mIgM interactions with actin filaments. In an attempt to determine the cytoskeleton-binding site of mIgM we investigated the role of the cytoplasmic tail of mIgM (KVK) in binding the receptor to actin-based microfilaments. Using mutated forms of mIgM expressed in J558L cells, we show here that KVK plays a role in mediating these interactions. The absence of KVK did not, however, completely abrogate mIgM-cytoskeletal interactions, suggesting that there are additional molecular requirements for the ligand-induced mIgM binding to the cytoskeletal matrix. 相似文献