全文获取类型
收费全文 | 19928篇 |
免费 | 924篇 |
国内免费 | 90篇 |
专业分类
耳鼻咽喉 | 146篇 |
儿科学 | 280篇 |
妇产科学 | 345篇 |
基础医学 | 2612篇 |
口腔科学 | 508篇 |
临床医学 | 1280篇 |
内科学 | 4904篇 |
皮肤病学 | 280篇 |
神经病学 | 1650篇 |
特种医学 | 772篇 |
外科学 | 3306篇 |
综合类 | 96篇 |
一般理论 | 1篇 |
预防医学 | 519篇 |
眼科学 | 730篇 |
药学 | 1506篇 |
中国医学 | 65篇 |
肿瘤学 | 1942篇 |
出版年
2023年 | 91篇 |
2022年 | 165篇 |
2021年 | 273篇 |
2020年 | 225篇 |
2019年 | 247篇 |
2018年 | 300篇 |
2017年 | 239篇 |
2016年 | 321篇 |
2015年 | 313篇 |
2014年 | 442篇 |
2013年 | 562篇 |
2012年 | 885篇 |
2011年 | 950篇 |
2010年 | 532篇 |
2009年 | 437篇 |
2008年 | 825篇 |
2007年 | 873篇 |
2006年 | 805篇 |
2005年 | 860篇 |
2004年 | 929篇 |
2003年 | 828篇 |
2002年 | 869篇 |
2001年 | 817篇 |
2000年 | 844篇 |
1999年 | 756篇 |
1998年 | 273篇 |
1997年 | 210篇 |
1996年 | 174篇 |
1995年 | 155篇 |
1994年 | 154篇 |
1993年 | 130篇 |
1992年 | 538篇 |
1991年 | 464篇 |
1990年 | 471篇 |
1989年 | 471篇 |
1988年 | 414篇 |
1987年 | 354篇 |
1986年 | 353篇 |
1985年 | 352篇 |
1984年 | 244篇 |
1983年 | 183篇 |
1982年 | 86篇 |
1979年 | 165篇 |
1978年 | 119篇 |
1977年 | 119篇 |
1974年 | 88篇 |
1972年 | 89篇 |
1971年 | 95篇 |
1968年 | 94篇 |
1967年 | 90篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
M Kaneda T Sakai T Hayashi T Hiraiwa Y Ohomoto K Shiroyama K Yoshimura 《Kyobu geka. The Japanese journal of thoracic surgery》1990,43(5):419-422
A rare case of solitary bronchial papilloma was reported. A 57-year-old male was admitted to our hospital because of an abnormal shadow on chest X-ray film which was discovered on regular health check up. Bronchoscopic examination revealed a polypoid tumor which obstructed the left B4 bronchus. Serum concentration of CEA was elevated up to 14 ng/ml by Z-GEL method. Left upper lobectomy was performed. On macroscopic examination of the excised specimen, the tumor arose in B4 bronchus and was yellowish white in color and was cauliflower-like in shape sized 3.5 X 1.5 cm. Histopathologically, the tumor consisted of papillary proliferation of stratified squamous epithelium with ciliated columnar epithelial covering. Findings suggestive of inflammation or malignancy were not observed. 相似文献
32.
J Shimizu Y Watanabe M Oda Y Hayashi T Iwa R Kamimura T Takashima 《Nihon Kyōbu Shikkan Gakkai zasshi》1991,29(10):1349-1353
A case of pulmonary varices in a 73-year-old female is presented. Routine chest X-ray revealed a mass in the right hilar region. CR tomogram showed a round, clearly defined mass at the right hilum. Computed tomography demonstrated marked enlargement of the proximal portion of the pulmonary vein at the entrance of the left atrium, which was suspected to be pulmonary varices. The diagnosis was confirmed by pulmonary angiography. During the arterial phase no abnormal findings were seen, but during the venous phase the veins of the right upper and middle lobes were found to be draining into the dilated pulmonary vein and then into the left atrium. Thus, the diagnosis of pulmonary varices was established. CT and angiography are the most useful methods for definitive diagnosis of pulmonary varices. 相似文献
33.
Cerebrovascular reserve capacity in ischemia due to occlusion of a major arterial trunk: studies by Xe-CT and the acetazolamide test. 总被引:2,自引:0,他引:2
T Yamashita M Hayashi S Kashiwagi S Nakano Y Eguchi T Takasago M Urakawa H Ito 《Journal of computer assisted tomography》1992,16(5):750-755
Classifications based on clinical and radiographic criteria have proved to be inadequate predictors of the course of cerebral ischemia or its response to therapy. In this study the cerebrovascular reserve capacity (CRC) of 46 patients with symptomatic cerebrovascular ischemia was studied by stable xenon-enhanced CT (Xe-CT) combined with the acetazolamide test. Fifteen patients had internal carotid artery (ICA) occlusion, 10 had ICA stenosis, 10 had middle cerebral artery (MCA) occlusion, and 11 had MCA stenosis. In the patients with chronic cerebral ischemia due to occlusive lesions of the ICA and MCA, the CRC was reduced most in those with MCA occlusion, followed, in descending order, by those with ICA stenosis, MCA stenosis, and ICA occlusion. Our results indicate that measurement of the CRC elucidates cerebral hemodynamic factors that cannot be detected by angiography in patients with chronic cerebral ischemia and that Xe-CT combined with the acetazolamide test is useful for this purpose. 相似文献
34.
Steady-state net flux of Mg2+ was measured in everted preparations of guinea pig jejunum and ileum, and effects of anoxia, Na+ and Ca2+ concentration, ouabain, and Ca2+ channel blockers were examined. Uphill Mg2+ flux in the mucosal-to-serosal direction was seen in both intestinal segments, with the flux value being 1.5 times greater in the ileum than in the jejenum. The Mg2+ flux was 1.7 times greater than the net Ca2+ flux under the same experimental conditions. The Mg2+ flux was strongly dependent on oxygen and the presence of Na+ in the medium; both anoxia and total replacement of Na+ inhibited the flux by 90-100%. Also, ouabain added to the serosal side, and verapamil or D600 added to the mucosal side, inhibited the flux by about 90%. Inhibitory effects of both ouabain and Na(+)-free conditions were much greater for the Mg2+ flux than for the Ca2+ flux. A stepwise increase in Mg2+ concentration in a Na(+)-free mucosal solution caused a stepwise elevation of the mucosal negativity. The relative elevation of the evoked potential in response to Mg2+ concentration possessed saturable and linearly increasing components. Only the saturable component was found to be dependent on oxygen and sensitive to ouabain. Under the influence of ouabain and verapamil, the generation of the Mg(2+)-evoked potential was greatly inhibited. These findings suggest that Mg2+ is actively absorbed by the jejunum and ileum of the guinea pig, and that active transcellular transport involves a verapamil-sensitive entry step and Na(+)-dependent or ouabain-sensitive exit process which differs from Ca2+ extrusion mechanisms. 相似文献
35.
Palmar advancement flap with V-Y closure for thumb tip injuries 总被引:1,自引:0,他引:1
Hwang-hyun Bang MD Tadao Kojima MD Hiroyuki Hayashi MD 《The Journal of hand surgery》1992,17(5):933-934
The palmar advancement flap with V-Y closure was used in two patients with thumb tip injuries. This technique allows more distal advancement of the flap than does a conventional palmar advancement flap and does not require skin graft coverage. 相似文献
36.
37.
38.
在免眼中进行经瞳孔阈值下温热疗法的组织学效应和蛋白表达 总被引:1,自引:0,他引:1
Yoshihiro Morimura Annabelle A. Okada Atsushi Hayashi Sayuri Fujioka Sumie Kawahara Tetsuo Hida 李扬 《美国医学会眼科杂志(中文版)》2005,17(3):185-186
目的:研究阈值下经瞳孔温热疗法(TTT)对视网膜组织学的效应。方法:对正常视网膜色素的兔眼进行TTT,通过1个810nm激光二极管产生直径为1.2mm能量为50mW的光斑,持续时间为15、30和60秒。4周后进行荧光血管造影并摘除眼球,通过电子显微镜和免疫组化染色来检查。 相似文献
39.
T Urakawa Y Nagahata S Fukuoka T Hayashi T Takata S Matsui M Nakamoto Y Hirai K Kumagai Y Saitoh 《Nihon Geka Gakkai zasshi》1986,87(2):180-188
We prepared obstructive jaundice models in rats in order to study the mechanism of acute ulceration in obstructive jaundice centering on impediments to gastric wall blood flow and changes in gastric mucosal NA and PGE2 when the rats were subjected to water immersion restraint stress. The results were: In the obstructive jaundice 2 weeks group, when subjected to water immersion restraint stress, gastric mucosal NA reached a dried up stage from the incipient stage, causing gastric mucosal impediments at the same time, showing a significant decrease of gastric mucosal PGE2. Intragastric pH was at a similar level of excessive acidity in all groups; gastric acid is believed to be a secondary factor promoting ulceration. Gastric mucosal PGE2 showed a significant decrease coinciding with the increase in ulceration index, being a possible factor of ulceration; it is also presumed to regulate gastric wall blood flow alternatively with gastric mucosal NA. Pre-treatment with PGE2 prior to loading stress resulted in a decrease in gastric wall blood flow being significantly controlled. The administration of PGE2 brought about an improvement in gastric wall blood flow and a consequent increase in gastric mucosal NA, being judged effective for acute ulceration in obstructive jaundice. 相似文献
40.
S Ueno R Ootsuka Y Hayashi H Nishitani N Shirakawa T Hashimoto 《Nihon Igaku Hōshasen Gakkai zasshi. Nippon acta radiologica》1992,52(10):1417-1423
Intracranial MR imaging was performed in five patients with achondroplasia. All patients had narrowing of the subarachnoid space at the level of the foramen magnum that was mainly due to protrusion of the posterior aspect. Three patients had compressive deformities of the brainstem and/or upper cervical spine. Among them, two patients had deformities of the pons. Relative upward displacement of the brainstem was seen in all patients. Hydrocephalus was seen in three patients. 相似文献