全文获取类型
收费全文 | 29263篇 |
免费 | 2225篇 |
国内免费 | 87篇 |
专业分类
耳鼻咽喉 | 386篇 |
儿科学 | 840篇 |
妇产科学 | 561篇 |
基础医学 | 3774篇 |
口腔科学 | 379篇 |
临床医学 | 2910篇 |
内科学 | 6394篇 |
皮肤病学 | 424篇 |
神经病学 | 2757篇 |
特种医学 | 1198篇 |
外科学 | 4988篇 |
综合类 | 308篇 |
现状与发展 | 1篇 |
一般理论 | 51篇 |
预防医学 | 2279篇 |
眼科学 | 434篇 |
药学 | 1479篇 |
中国医学 | 45篇 |
肿瘤学 | 2367篇 |
出版年
2023年 | 323篇 |
2022年 | 560篇 |
2021年 | 1293篇 |
2020年 | 707篇 |
2019年 | 1020篇 |
2018年 | 1231篇 |
2017年 | 857篇 |
2016年 | 831篇 |
2015年 | 1005篇 |
2014年 | 1361篇 |
2013年 | 1654篇 |
2012年 | 2425篇 |
2011年 | 2381篇 |
2010年 | 1291篇 |
2009年 | 1024篇 |
2008年 | 1579篇 |
2007年 | 1654篇 |
2006年 | 1464篇 |
2005年 | 1331篇 |
2004年 | 1147篇 |
2003年 | 975篇 |
2002年 | 835篇 |
2001年 | 239篇 |
2000年 | 228篇 |
1999年 | 228篇 |
1998年 | 171篇 |
1997年 | 153篇 |
1996年 | 157篇 |
1995年 | 134篇 |
1994年 | 119篇 |
1993年 | 108篇 |
1992年 | 157篇 |
1991年 | 177篇 |
1990年 | 155篇 |
1989年 | 177篇 |
1988年 | 142篇 |
1987年 | 148篇 |
1986年 | 127篇 |
1985年 | 123篇 |
1984年 | 133篇 |
1983年 | 117篇 |
1982年 | 105篇 |
1981年 | 99篇 |
1980年 | 77篇 |
1979年 | 117篇 |
1978年 | 119篇 |
1977年 | 72篇 |
1976年 | 67篇 |
1973年 | 65篇 |
1972年 | 58篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
131.
132.
Converging visual and somatic sensory cortical input to the intraparietal sulcus of the rhesus monkey 总被引:5,自引:0,他引:5
A cyto- and myeloarchitectonic study reveals the presence of a distinct cortical zone ("area POa") in the lower bank of the intraparietal sulcus of the rhesus monkey. Using both autoradiographic and silver impregnation techniques, an analysis of cortical connections shows two overlapping projections to this sulcal zone. These come from (1) the middle portion of the preoccipital gyrus (area OA) and (2) the rostral inferior parietal lobule (area PF). 相似文献
133.
Toxicology of various pesticides and their decomposition products on mitochondrial electron transport 总被引:2,自引:0,他引:2
Ronald S. Pardini James C. Heidker Theresa A. Baker Benjamin Payne 《Archives of environmental contamination and toxicology》1980,9(1):87-97
The effect of various pesticides and derivatives on mitochondrial electron transport systems was assessed. DDT, DDE, TDE, Kelthane, chlorobenzilate, chloropropylate and Acarol were found to be inhibitory towards both heavy beef heart mitochondrial (HBHM) NADH-oxidase and succinoxidase enzyme systems. Dichlorobenzophenone andp-chlorophenol were less inhibitory towards the HBHM NADH-oxidase and did not inhibit the succinoxidase enzyme system. DDA did not inhibit either of the electron transport systems. Carbaryl was not inhibitory towards both HBHM oxidase systems, whereas its degradative product dihydroxynaphthalene was inhibitory at the same concentration. Furadan, Matacil, Baygon and Dimetilan were only slightly inhibitory towards the mitochondrial NADH-oxidase system and did not inhibit the succinoxidase system. Zectran was inhibitory towards the NADH-oxidase system and was not inhibitory towards the succinoxidase system. DDT, DDE and TDE, dihydroxynaphthalene and 1-naphthol inhibited the NADH-oxidase enzyme system on the substrate side of cytochrome c, whereas Kelthane inhibited on the oxygen side.Contribution to Regional Project W-45, Residues of Pesticides and Related Chemicals in the Agricultural Environment-Their Nature, Distribution, Persistence, and Texicological Implications. University of Nevada Agricultural Experiment Station No. 432. 相似文献
134.
Dr. S. B. Benjamin MD J. K. O'Donnell MD J. Hancock MD P. Nielsen MD Dr. D. O. Castell MD 《Digestive diseases and sciences》1983,28(9):775-779
Symptomatic patients with abnormal esophageal manometry characterized by esophageal peristaltic waves of increased amplitude (the nutcracker esophagus, NE) have been recognized with increasing frequency. Whether or not this represents a true functional abnormality is unresolved at this time. We have utilized radionuclide transit (RT), a true esophageal function test, to evaluate patients with NE. Eighteen consecutive symptomatic patients with the NE and ten clinically and manometrically normal subjects constituted this study group. RT in normals were 6.8±0.2 sec (
±Se) and 27.6±3.8 in patients with NE. RT was abnormal in 17/18 patients with NE. Chaotic bolus transit was seen in 11/18 patients with NE but not in normals. The defect was localized to the distal esophagus since transit through the proximal esophagus was not significantly different between the two groups. This defect in RT may be related to spontaneous simultaneous contractions seen in 50% of these patients. Further work will be necessary to determine if NE is a true functional abnormality or a marker for other motility abnormalities such as diffuse esophageal spasm.This study is supported by Navy Clinical Investigation Protocol No. 0-06-1398.The opinions and assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Navy or the Department of Defense. 相似文献
135.
The normal progressive physiological and visual effects of aging and its influence on the ability of contact lenses to provide ametropic correction is examined in this article. Of primary significance is the aging eye's perceptual ability especially in the mesopic range of vision. In addition, a recap of current available techniques is included for correction of presbyopia with contact lenses from the perspective of prescribing for an aging patient--not merely a patient who has lost only the ability to accommodate. One of the hallmarks of the profession of optometry has been its traditional support of the premise that patients should be provided with the best possible optical correction. While there are presbyopic patients who can achieve satisfactory vision via the contact lens modalities now in use, the physiological influences discussed here have been generally ignored by the profession. A redefinition of the criteria indicating patient "success" has evolved from achieving satisfaction through excellent vision derived from the optimum optical correction, to satisfaction obtained through patient selection and indoctrination to wear an optically inferior device. Unless the physiological, visual, and psychological effects of aging are adequately compensated by future contact lens designs, most elderly patients will remain likely to return to spectacles as the deficiencies of contact lens correction become progressively more apparent to them. 相似文献
136.
Benjamin P. Haynes Michael Jarman Mitchell Dowsett Anshumala Mehta Per E. Lønning Leslie J. Griggs Alison Jones Trevor Powles Rob Stein R. Charles Coombes 《Cancer chemotherapy and pharmacology》1991,27(5):367-372
Summary The pyridylglutarimide 3-ethyl-3-(4-pyridyl)-piperidine-2,6-dione (PyG) is a novel inhibitor of aromatase that was shown to cause effective suppression of plasma oestradiol levels in postmenopausal patients. In four patients receiving oral doses of PyG (500 mg) twice daily for 3–4 days, oestradiol levels fell to 31.1%±6.3% of baseline values within 48 h and remained suppressed during treatment. Of a further six patients who received oral PyG (1 g) as a single dose, five had quantifiable oestradiol levels. Oestradiol suppression was sustained for 36 h and recovery correlated with a fall of PyG concentrations below a threshold value of ca. 2 g/ml. The pharmacokinetics of PyG were non-linear and, when fitted to the integrated Michaelis-Menten equation, yielded good parameter estimates forC
o (21.7±1.82 g/ml),K
m (2.66±0.68 g/ml) and Vmax (0.86±0.06 g ml–1 h–1). On subsequent repeated dosing with PyG, both theK
m (4.31±0.48 g/ml) and the Vmax (1.83±0.13 g ml–1 h–1) values increased and recovery from oestradiol suppression was more rapid, indicating that PyG induces its own metabolism.Abbreviations PyG
3-ethyl-3-(4-pyridyl)piperidine-2,6-dione
- AG
aminoglutethimide
- CSCC
cholesterol side-chain cleavage
- HPLC
high-performance liquid chromatography
- AUC
area under the concentration versus time curve
This study was supported in part by grants to the Institute of Cancer Research (Royal Cancer Hospital) from the Cancer Research Campaign and Medical Research Council 相似文献
137.
138.
A 30-year-old patient with tardive dystonia, who had failed to respond to cessation of neuroleptics, placebo, diazepam, biperiden, propranolol, and clonidine, had an impressive response to courses of electroconvulsive therapy (ECT) on three successive trials. 相似文献
139.
The Afghan osteotomy was combined with external fixation on 19 patients (23 extremities) with late-onset tibia vara. The average weight was 258 lb and all patients weighed >95th percentile. The average preoperative deformity was 28.2 degrees. The average intraoperative correction was 27.6 degrees. Average healing time was 141 days. The mean follow-up was 2.7 years. Based on radiographic correction, at long-term follow-up, there were 15 excellent, two fair, and six poor results. The quality of the initial correction was the only significant variable, and it was borderline (p = 0.0587). Complications included loss of alignment, peroneal nerve palsy, superficial pin tract infection, deep infection, and fracture. This method offers a technically simple procedure with a relatively low complication rate. It allows early mobilization and provides the ability to manipulate the correction postoperatively. An excellent long-term outcome is predicated on achieving an acceptable initial correction as determined by intraoperative mechanical axis radiographs. 相似文献
140.