全文获取类型
收费全文 | 4937篇 |
免费 | 519篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 50篇 |
儿科学 | 198篇 |
妇产科学 | 117篇 |
基础医学 | 584篇 |
口腔科学 | 123篇 |
临床医学 | 597篇 |
内科学 | 1147篇 |
皮肤病学 | 34篇 |
神经病学 | 359篇 |
特种医学 | 274篇 |
外科学 | 483篇 |
综合类 | 200篇 |
一般理论 | 8篇 |
预防医学 | 527篇 |
眼科学 | 39篇 |
药学 | 371篇 |
中国医学 | 13篇 |
肿瘤学 | 346篇 |
出版年
2021年 | 80篇 |
2020年 | 52篇 |
2019年 | 71篇 |
2018年 | 109篇 |
2017年 | 83篇 |
2016年 | 84篇 |
2015年 | 95篇 |
2014年 | 124篇 |
2013年 | 199篇 |
2012年 | 202篇 |
2011年 | 239篇 |
2010年 | 146篇 |
2009年 | 150篇 |
2008年 | 199篇 |
2007年 | 231篇 |
2006年 | 217篇 |
2005年 | 219篇 |
2004年 | 206篇 |
2003年 | 182篇 |
2002年 | 210篇 |
2001年 | 165篇 |
2000年 | 146篇 |
1999年 | 133篇 |
1998年 | 104篇 |
1997年 | 100篇 |
1996年 | 89篇 |
1995年 | 94篇 |
1994年 | 55篇 |
1993年 | 60篇 |
1992年 | 83篇 |
1991年 | 108篇 |
1990年 | 70篇 |
1989年 | 93篇 |
1988年 | 104篇 |
1987年 | 107篇 |
1986年 | 73篇 |
1985年 | 77篇 |
1984年 | 62篇 |
1983年 | 48篇 |
1982年 | 29篇 |
1981年 | 34篇 |
1979年 | 42篇 |
1977年 | 32篇 |
1975年 | 28篇 |
1974年 | 29篇 |
1973年 | 41篇 |
1972年 | 30篇 |
1971年 | 30篇 |
1970年 | 27篇 |
1969年 | 27篇 |
排序方式: 共有5470条查询结果,搜索用时 15 毫秒
31.
J Davies B Srinivasan PA Brennan 《Annals of the Royal College of Surgeons of England》2021,103(1):e42
Lipomas are common benign tumours that can occur in most parts of the body. Lipomas arising from the deep temporal fat pad, found between the two layers of the deep temporal fascia, are rare, however; there has been only one documented case report to our knowledge. We describe a second case arising from the temporal fat pad in a patient treated at our unit, having previously reported the first one, and discuss the relevant anatomy and management. 相似文献
32.
Joshua R Lewis Trudy Voortman John PA Ioannidis 《Journal of bone and mineral research》2021,36(2):219-226
A healthy diet is essential to attain genetically determined peak bone mass and maintain optimal skeletal health across the adult lifespan. Despite the importance of nutrition for bone health, many of the nutritional requirements of the skeleton across the lifespan remain underexplored, poorly understood, or controversial. With increasingly aging populations, combined with rapidly changing diets and lifestyles globally, one anticipates large increases in the prevalence of osteoporosis and incidence of osteoporotic fractures. Robust, transparent, and reproducible nutrition research is a cornerstone for developing reliable public health recommendations to prevent osteoporosis and osteoporotic fractures. However, nutrition research is often criticized or ignored by healthcare professionals due to the overemphasis of weak science, conflicting, confusing or implausible findings, industry interests, common misconceptions, and strong opinions. Conversely, spurious research findings are often overemphasized or misconstrued by the media or prominent figures especially via social media, potentially leading to confusion and a lack of trust by the general public. Recently, reforms of the broader discipline of nutrition science have been suggested and promoted, leading to new tools and recommendations to attempt to address these issues. In this perspective, we provide a brief overview of what has been achieved in the field on nutrition and bone health, focusing on osteoporosis and osteoporotic fractures. We discuss what we view as some of the challenges, including inherent difficulties in assessing diet and its change, disentangling complex interactions between dietary components and between diet and other factors, selection of bone-related outcomes for nutrition studies, obtaining evidence with more unbiased designs, and perhaps most importantly, ensuring the trust of the public and healthcare professionals. This perspective also provides specific recommendations and highlights new developments and future opportunities for scientists studying nutrition and bone health. © 2021 American Society for Bone and Mineral Research (ASBMR). 相似文献
33.
34.
Retrobulbar haemorrhage (RBH) occurs in a variety of situations. It can complicate facial fractures, orbital surgery and retrobulbar injections and can occur spontaneously. It is relatively uncommon and sight-threatening RBH is even less common. If not detected early enough it can lead to devastating loss of vision. We have collected five cases of acute RBH, following trauma, associated with a profound reduction in vision. In each case a permanent loss of vision was avoided using a lateral canthotomy and inferior cantholysis approach to obtain urgent orbital decompression. 相似文献
35.
Clinical-neuroimaging analysis of 12 thrombotic thrombocytopenic purpura (TTP) patients revealed a variety of brain lesions. These included reversible cerebral edema lesions with MRI features of reversible posterior leukoencephalopathy syndrome (RPLS). Most of the RPLS patients had hypertension and renal dysfunction, suggesting RPLS due to hypertensive encephalopathy. Prompt treatment usually led to neurologic recovery and disappearance of edematous lesions. Those with infarcts or hematomas had a poorer outcome. TTP should be added to the expanding spectrum of RPLS and hypertensive encephalopathy. 相似文献
36.
Kosinski CM Cha JH Young AB Mangiarini L Bates G Schiefer J Schwarz M 《Neuroreport》1999,10(18):3891-3896
R6/2 transgenic mice express exon 1 of an abnormal human Huntington's disease (HD) gene and develop a neurological phenotype similar to HD. These mice develop ubiquitinated neuronal intranuclear inclusions (NII) which might play a central role in the pathophysiology of HD. We studied the distribution of NII in subpopulations of striatal neurons in 12-week-old R6/2 transgenic mice using fluorescent double label immunohistochemistry. We observed that most of the Calbindin-D28K positive projection neurons (89%) and the Parvalbumin positive interneurons (86%) showed ubiquitinated NII. In interneurons, however, which contain either choline acetyltransferase, neuronal nitric oxide synthase, or Calretinin, the frequency of NII was much lower (22%, 8%, 9%, respectively). Our data suggest that subpopulations of striatal neurons differ remarkably in their capability of forming ubiquitinated NII. Interneurons which are known to resist neurodegeneration in HD show less NII. 相似文献
37.
38.
Kenyon SH Waterfield CJ Asker DS Kudo M Moss DW Bates TE Nicolaou A Gibbons WA Timbrell JA 《Biochemical pharmacology》1999,57(11):1311-1319
The effect of the industrial chemical, hydrazine (4-12 mM), on methionine synthase (EC 2.1.1.13) activity and levels of the sulphur amino acids homocysteine, cysteine, and taurine as well as GSH were investigated in vitro in isolated rat hepatocyte suspensions and monolayers in order to explain some of the adverse in vivo effects of hydrazine. None of the concentrations of hydrazine were overtly cytotoxic in hepatocyte suspensions (measured as lactate dehydrogenase [LDH] leakage) after 3 hr. However, after 24 hr in culture cells treated with 12 mM, hydrazine showed a significant increase in LDH leakage. Methionine synthase activity was reduced by hydrazine (8 and 12 mM) in suspensions (by 45 and 55%, after 3 hr) and monolayers (12 mM; 65-80% after 24 hr). This was not due to nitric oxide production and the inhibitor of nitric oxide synthase, Nomega-nitro-L-arginine, failed to protect against the hydrazine-induced loss of ATP and GSH and the reduction in urea synthesis at 24 hr. Homocysteine export was increased by 6 mM hydrazine, and total taurine content of treated cells was increased by 12 mM hydrazine. Thus, hydrazine was found to have several important and possibly deleterious effects on some parts of the sulphur amino acid pathway. 相似文献
39.
Setzer WN Setzer MC Bates RB Nakkiew P Jackes BR Chen L McFerrin MB Meehan EJ 《Planta medica》1999,65(8):747-749
The crude chloroform bark extract of Piper caninum (Piperaceae) exhibits antibacterial activity against the Gram-positive bacteria, Bacillus cereus, Staphylococcus aureus, and Streptococcus pneumoniae. The antibacterial agents in this extract have been isolated using bioactivity-directed chromatographic techniques and identified by NMR spectroscopy as (+)-bornyl p-coumarate and bornyl caffeate. A single-crystal X-ray structure has been carried out on (+)-bornyl p-coumarate. The compound crystallizes in the orthorhombic space group P2(1)2(1)2(1) (#19) with a = 12.659(4), b = 13.281(4), and c = 10.177(3) A. Fullmatrix least-squares refinement converged at R = 0.047, and Rw = 0.058. 相似文献
40.
R F Mankes R LeFevre H Bates R Abraham 《Journal of toxicology and environmental health》1983,12(2-3):235-244
Phenylethanol was given at different levels (432, 43, or 4.3 mg/kg) by gavage to pregnant Long-Evans rats during the "critical period" of organogenesis. Examination of offspring revealed adverse reproductive and teratogenic effects in a dose-related manner. Intrauterine growth retardation occurred at levels of 432 and 4.3 mg/kg. Embryolethality was 18% at 43 mg/kg and 10% at 4.3 mg/kg. Malformations occurred in the following sequence: 100% at 432 mg/kg; 93% at 43 mg/kg, and 50% at 4.3 mg/kg. Noteworthy dose-related teratogenic effects of phenylethanol in offspring manifested themselves in increased incidences of malformed eyes, neural-tube defects, hydronephrosis, and limb defects. 相似文献