全文获取类型
收费全文 | 7230篇 |
免费 | 331篇 |
国内免费 | 74篇 |
专业分类
耳鼻咽喉 | 49篇 |
儿科学 | 217篇 |
妇产科学 | 120篇 |
基础医学 | 815篇 |
口腔科学 | 194篇 |
临床医学 | 422篇 |
内科学 | 2175篇 |
皮肤病学 | 76篇 |
神经病学 | 560篇 |
特种医学 | 317篇 |
外科学 | 1229篇 |
综合类 | 18篇 |
预防医学 | 105篇 |
眼科学 | 86篇 |
药学 | 352篇 |
中国医学 | 17篇 |
肿瘤学 | 883篇 |
出版年
2023年 | 56篇 |
2022年 | 109篇 |
2021年 | 191篇 |
2020年 | 98篇 |
2019年 | 165篇 |
2018年 | 183篇 |
2017年 | 166篇 |
2016年 | 210篇 |
2015年 | 181篇 |
2014年 | 276篇 |
2013年 | 297篇 |
2012年 | 471篇 |
2011年 | 531篇 |
2010年 | 337篇 |
2009年 | 275篇 |
2008年 | 437篇 |
2007年 | 454篇 |
2006年 | 466篇 |
2005年 | 510篇 |
2004年 | 496篇 |
2003年 | 430篇 |
2002年 | 421篇 |
2001年 | 63篇 |
2000年 | 58篇 |
1999年 | 70篇 |
1998年 | 84篇 |
1997年 | 64篇 |
1996年 | 58篇 |
1995年 | 50篇 |
1994年 | 45篇 |
1993年 | 39篇 |
1992年 | 26篇 |
1991年 | 33篇 |
1990年 | 30篇 |
1989年 | 40篇 |
1988年 | 28篇 |
1987年 | 20篇 |
1986年 | 10篇 |
1985年 | 10篇 |
1984年 | 9篇 |
1983年 | 13篇 |
1982年 | 29篇 |
1981年 | 17篇 |
1980年 | 11篇 |
1979年 | 9篇 |
1978年 | 10篇 |
1977年 | 14篇 |
1975年 | 4篇 |
1972年 | 5篇 |
1967年 | 4篇 |
排序方式: 共有7635条查询结果,搜索用时 15 毫秒
1.
Eijiro Morita Torao Tanaka Tetsuya Nakamura Fumitaka Terabe Ichiro Hirata Kenichi Katsu Masakazu Takazoe Akira Terano 《Digestive endoscopy》2006,18(4):263-268
Background and Aims: Video capsule endoscopy (VCE) has become increasingly important as a simple method for observing the entire small intestine. The indications for VCE are obscure gastrointestinal bleeding and investigation of Crohn’s disease (CD). However, the correlation between endoscopic findings obtained by VCE and clinical findings in known cases of CD is not clear, and we therefore investigated this in the present study. Patients and methods: In 30 patients with known CD (Crohn’s disease activity index [CDAI] 0–420; median = 158.3), double contrast enteroclysis (ENT) was performed 1–3 weeks prior to VCE. The relationship between the VCE findings and hematological analysis/CDAI was examined. Results: In 17 of 30 patients, the entire small intestine could be investigated by VCE, whereas in the remaining 13 patients the terminal ileum could not be investigated. The following exhibited positive correlations: total lesions and CDAI (correlation coefficient values: rs = 0.661, adjusted P < 0.0061), ulcers and C‐reactive protein (CRP) (rs = 0.607, adjusted P < 0.0061), total lesions and CRP (rs = 0.604, adjusted P < 0.0061). Conclusions: Analysis with VCE suggests that CDAI and CRP indicate the activity of intestinal lesions in patients with known CD, and that CRP, in particular, is associated with the activity of ulcerative lesions of the intestine. This may contribute to revised guidelines for VCE in the future. 相似文献
2.
Kensaku Maeda Kenichi Yasunari Eisuke F Sato Junichi Yoshikawa Masayasu Inoue 《Hypertension research》2003,26(12):999-1006
The involvement of oxidative stress in polymorphonuclear leukocytes (PMN) in the pathogenesis of hypertension remains to be elucidated. We analyzed the generation of reactive oxygen species (ROS) by the circulating and peritoneally infiltrating PMN from spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Flow cytometric analysis revealed that ROS generation by PMN from SHR was higher than that from WKY before (at 6 weeks of age) and after (at 16 weeks of age) the onset of hypertension. In vivo, ROS generation by PMN from SHR, but not that by PMN from WKY, was significantly suppressed by 10-week treatment with 50 mg/kg/day carvedilol, and this treatment did not affect blood pressure. Western blotting analysis revealed that protein kinase C alpha (PKCalpha), but not PKCbetaI or betaII, was activated more strongly in PMN from SHR than in PMN from WKY. Furthermore, expression of p47phox of nicotinamide adenine dinucleotide phosphate oxidase, but not of p67phox, in PMN from SHR was higher than that in PMN from WKY. These results suggest that ROS generation by PMN is principally enhanced in SHR through activation of PKCalpha and p47phox. 相似文献
3.
4.
Hiroaki Matsuura Hizuru Miyamoto Kenichi Kurita Alastair N Goss 《Journal of oral and maxillofacial surgery》2006,64(10):1517-1525
PURPOSE: The purpose of this study was to test the functional and histologic fate of costochondral grafts (CG) in temporomandibular joint (TMJ) reconstruction for unilateral ankylosis in the sheep. MATERIALS AND METHODS: Five pure-bred adult Merino sheep were used. Ankylosis was induced by articular damage, disc removal, and placement of a bone graft. At 3 months, a gap arthroplasty was performed with a CG from the thirteenth rib. The sheep were sacrificed 3 months after CG reconstruction. The range of jaw movements were recorded at first operation, at lysis of ankylosis, and at sacrifice. The joints were examined radiologically, macroscopically, and histologically. RESULTS: All sheep showed a decrease in masticatory function, as shown by weight loss and decreased jaw opening, during the ankylosis period. On release, they regained weight and increased the range of jaw movement. Histologically, the joint space was filled with fibrous tissue. However, the partial spaces around the CG head were covered by fibrous tissue and/or fibrous cartilage. CONCLUSIONS: This study shows that, when CGs are used with a gap arthroplasty in a fibrous and bony ankylosed TMJ, masticatory function is restored. 相似文献
5.
Keijiro Sunada Hironori Yamamoto Hiroto Kita Tomonori Yano Tomohiko Miyata Yutaka Sekine Akiko Kuno Nobuki Onishi Michiko Iwamoto Atsuhiro Sasaki Kenichi Ido Kentaro Sugano 《Digestive endoscopy》2004,16(3):237-240
The requirement for endoscopic access to a stricture is a major limitation of the endoscopic dilatation for the treatment of strictures in the gastrointestinal tract. We have developed the double‐balloon enteroscopy method that enables visualization of the entire small bowel. In addition, double‐balloon enteroscopy has a potential for the interventional therapy including dilatation of strictures. We present here a case of jejunal strictures in a 47‐year‐old woman with Crohn's disease successfully treated with a balloon catheter in combination with double‐balloon enteroscopy. Balloon dilation with double‐balloon enteroscopy is a promising method for the treatment of small bowel strictures in Crohn's disease. 相似文献
6.
Abstract: We analyzed the expression of CEA, CA19-9, CA125, CA15-3 (DF3), PCNA and p53 immunohistochemically in 14 tissue specimens of mucosal cancers in adenoma, seven tubulovillous adenoma specimens, and 16 tubular adenoma specimens. The rates of positive staining for mucosal cancer in adenoma, tubulovillous adenoma and tubular adenoma specimens, respectively, were: for CEA: 100%, 85.7% and 75%; for CA19-9: 71.4%, 71.4% and 56.2%; for CA125:0%, 0% and 0%;for CA15-3 (DF3): 64.3 %, 0% and 0 %; for PCNA: 100%, 88.9% and 56.2%; and for p53: 35.7%, 0% and 0% . The results suggest that the expressions of CEA, CA19-9, CA15-3 (DF3), PCNA and p53 are related to colorectal tumorigenesis. None of the specimens studied showed staining for CA125, suggesting that CA125 is not involved in the early stages of colorectal carcinogenesis. There was no significant difference in the rates of positive staining for CEA and CA19-9 among mucosal cancer in adenoma, tubular adenoma and tubulovillous adenoma specimens. However, the rates of positive staining for PCNA and p53 were significantly higher in mucosal cancer in adenoma specimens than for tubular adenoma specimens (p<0.05), and the rate of CA15-3 (DF3) positive staining was significantly higher for mucosal cancer in adenoma than for tubulovillous adenoma (p<0.01) and tubular adenoma (p< 0.001) specimens. Therefore, the CA15-3 (DF3) antigen is an immunohistochemical marker for colorectal carcinomas. The present results suggest that CA15-3 (DF3), PCNA and p53 play important roles in the genesis of colorectal adenomas. 相似文献
7.
The characteristics of a glial Na+,K+-pump dependent on extracellular K+ within epileptogenic cortex were studied electrophysiologically, biochemically and histochemically in vitro using slices from cobalt-induced epileptogenic cortex of rat. When the extracellular K+ concentration ([K+]o) was varied between 4 and 40 mM, the mean slope of membrane potential plotted against [K+]o was about 57 mV in glia from the normal cortex (tissue A) and about 44 mV in glia from the epileptogenic cortex (tissue B); whereas no significant difference in the resting membrane potential of these tissues was observed. In glia from tissue B, a marked transient hyperpolarization above control level was caused by replacement of elevated [K+]o with the normal medium. Ouabain abolished these phenomena observed in glia from tissue B, but had no effect on the membrane potential during normal [K+]o. Reduction of extracellular Na+, Ca2+ and Cl− did not significantly affect the membrane potential of glia from either tissue. In tissue A, the cells marked by intracellular injection of horseradish peroxidase after intracellular recording were protoplasmic astrocytes; in tissue B, fibrous astrocytes with abnormal processes predominated. K+-dependent stimulation of Na+,K+-ATPase activity of the astrocyte-enriched fraction and its membrane preparation from tissue B was much larger than that from tissue A. A certain amount of the reaction product of K+-pNPPase activity was seen on glial plasma membrane within tissue B but not on that from tissue A. The above findings suggest that a glial Na+,K+-pump within actively firing epileptogenic cortex may be modified to increase in its activity. 相似文献
8.
9.
We report a case of cortical reflex myoclonus in adult onset Huntington's disease (HD). The patient is a 51-year-old woman. Chorea and myoclonus were observed on her face and extremities. Neurophysiological tests showed C reflex and abnormal waves preceding myoclonus by jerk-locked back averaging method but no giant somatosensory evoked potential. Gene analysis revealed the prolongation of CAG repeats (13/44) in IT15 gene. Oral administration of clonazepam was transiently effective for myoclonus. We should inscribe that the cortical reflex myoclonus may exceptionally manifest in HD. 相似文献
10.