全文获取类型
收费全文 | 12063篇 |
免费 | 650篇 |
国内免费 | 57篇 |
专业分类
耳鼻咽喉 | 100篇 |
儿科学 | 196篇 |
妇产科学 | 114篇 |
基础医学 | 1742篇 |
口腔科学 | 220篇 |
临床医学 | 781篇 |
内科学 | 3082篇 |
皮肤病学 | 221篇 |
神经病学 | 846篇 |
特种医学 | 432篇 |
外科学 | 1928篇 |
综合类 | 49篇 |
预防医学 | 455篇 |
眼科学 | 273篇 |
药学 | 918篇 |
1篇 | |
中国医学 | 21篇 |
肿瘤学 | 1391篇 |
出版年
2023年 | 72篇 |
2022年 | 137篇 |
2021年 | 223篇 |
2020年 | 101篇 |
2019年 | 173篇 |
2018年 | 210篇 |
2017年 | 161篇 |
2016年 | 203篇 |
2015年 | 222篇 |
2014年 | 262篇 |
2013年 | 316篇 |
2012年 | 526篇 |
2011年 | 574篇 |
2010年 | 280篇 |
2009年 | 288篇 |
2008年 | 504篇 |
2007年 | 539篇 |
2006年 | 541篇 |
2005年 | 505篇 |
2004年 | 506篇 |
2003年 | 508篇 |
2002年 | 522篇 |
2001年 | 478篇 |
2000年 | 487篇 |
1999年 | 406篇 |
1998年 | 190篇 |
1997年 | 134篇 |
1996年 | 138篇 |
1995年 | 120篇 |
1994年 | 111篇 |
1993年 | 90篇 |
1992年 | 312篇 |
1991年 | 250篇 |
1990年 | 258篇 |
1989年 | 253篇 |
1988年 | 220篇 |
1987年 | 189篇 |
1986年 | 205篇 |
1985年 | 200篇 |
1984年 | 151篇 |
1983年 | 120篇 |
1982年 | 63篇 |
1979年 | 138篇 |
1978年 | 83篇 |
1977年 | 74篇 |
1975年 | 64篇 |
1974年 | 65篇 |
1972年 | 58篇 |
1971年 | 60篇 |
1969年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
A time course study on the appearance and distribution of cells immunoreactive for spot 35 protein, a novel cerebellar Purkinje cell-specific protein, was conducted in the developing cerebella of fetal and early postnatal rats by PAP immunohistochemistry. Spot 35-immunoreactive cells were first noted in the cerebellar anlage on the 17th embryonic day, appearing as large cellular aggregations in the mantle layer and a small number of elongated cells dispersed between the cell aggregations and the ependymal layer. As the development proceeded, the spot 35-immunoreactive cells gradually accumulated beneath the external granular layer. At birth, they were arranged compactly in 4-5 irregular rows to form a primitive Purkinje cell layer. During their subsequent development, immunostaining for spot 35 protein demonstrated the rearrangement of the Purkinje cells into a single row and the maturation of their somata, axons and dendrites. All these findings indicate that spot 35 protein is a specific marker for the cerebellar Purkinje cells, from their migrating stage throughout the course of their maturation. The present study further describes the transitory lamellar arrangement of spot 35-immunoreactive Purkinje cells located horizontally at a short distance away from the ependymal layer of the cerebellum on the 17th embryonic day. 相似文献
42.
T Kokubo Y Ohtomo J Iseki T Toyoda S Kondo F Hattori K Itoh K Kojima 《Radiation Medicine》1986,4(4):124-126
The case of a 38-year-old man with an exogastric leiomyoblastoma is reported. CT and ultrasound examinations revealed a large mass in the left hypochondrium that had both solid and cystic components. These findings mimicked those of cystadenoma of the pancreas. Because of intraperitoneal hemorrhage in the preoperative course, emergency laparotomy was performed. A large tumor was found to arise from the greater curvature of the stomach. The diagnosis was confirmed histologically. 相似文献
43.
To improve the rectal delivery of ethyl 4-biphenylylacetate (EBA), a prodrug of the anti-inflammatory drug 4-biphenylylacetic acid (BPAA), the use of highly water-soluble 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CyD) and heptakis(2,6-di-O-methyl)-beta-cyclodextrin (DM-beta-CyD) was investigated and compared with the use of the parent beta-cyclodextrin (beta-CyD). Among the three beta-CyDs, HP-beta-CyD was best at improving the rectal bioavailability of EBA in rats after single and multiple administrations of oleaginous suppositories (Witepsol H-5) containing the complexes. To gain insight into the enhancing effect of beta-CyDs, the absorption behaviors of EBA (observed by monitoring BPAA as an active metabolite of EBA) and beta-CyDs themselves were examined in vitro, in situ, and in vivo. The in situ recirculation study revealed that the complexed form of EBA was less absorbable from the rectal lumen in the solution state, but this disadvantageous effect of beta-CyDs was compensated in part by the inhibition of the bioconversion of EBA to BPAA. When beta-CyDs were coadministered with EBA in vivo, however, rather high amounts of HP-beta-CyD (approximately 26% of dose) and DM-beta-CyD (approximately 21% of dose), compared with beta-CyD (approximately 5% of dose), were absorbed from the rat rectum. Thus, the enhancement of rectal absorption of EBA in vivo can be explained by the facts that the hydrophilic beta-CyDs increased the release rate of EBA from the vehicle and stabilized EBA in the rectal lumen and that the drug was partly absorbed in the form of the complex.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
44.
45.
AIM: The role of air plethysmography (APG) in the diagnosis of chronic venous insufficiency has not been well established. The purpose of this study was to elucidate the relationship between APG parameters and clinical severity in patients with chronic venous insufficiency. METHODS: Two hundred and ninety-four limbs in 154 patients with primary varicose veins were evaluated by APG. Limbs were categorized according to the clinical classification of chronic venous disease suggested by the Ad Hoc Committee on Reporting Standards in Venous Disease of the North American Chapter of the Society for Vascular Surgery and International Society for Cardiovascular Surgery (SVS/ ISCVS). RESULTS: The venous filling index (VFI) was significantly higher in classes 2, 3, 4, and 5+6 than in class 0 or 1, and did not differ among classes 2, 3, 4, 5+6. The ejection fraction did not differ significantly among the 6 classes, and the residual volume fraction was significantly higher in classes 2, 3, 5+6 than in class 0. CONCLUSIONS: APG is a reasonable method for distinguishing the presence or absence of chronic venous insufficiency, but it cannot discriminate the clinical severity. Among APG parameters, the VFI is the most useful diagnostic parameter in the evaluation of chronic venous insufficiency. 相似文献
46.
47.
48.
Relevance of inflammatory cell infiltrates for complete atrioventricular block in experimental murine myocarditis. 总被引:2,自引:0,他引:2
BACKGROUND: There are few systemic pathologic studies on myocarditis. This study aimed to clarify the pathologic characteristics of murine myocarditis. METHODS: We recorded serial electrocardiograms in experimental viral myocarditis in mice and then examined their cardiac pathology. After taking baseline electrocardiograms, we inoculated the mice intraperitoneally with the encephalomyocarditis virus. Electrocardiograms were serially recorded until 220 days after the virus inoculation. RESULTS: Serial electrocardiograms revealed ectopic beats, low voltage of the QRS complex, and the appearance of complete atrioventricular (AV) block. Corresponding myocardial lesions were found in the hearts of mice with these ectopic beats. Mononuclear cell infiltrations into the His bundle were most frequently found in mice with complete AV block. CONCLUSIONS: Inflammatory change with cellular infiltrations was the most common pathologic finding in mice with complete AV block. In clinical settings, anti-inflammatory therapy might be recommended for patients with myocarditis complicated with conduction disturbances. 相似文献
49.
Atsushi Takai Yoshihiro Okabe Nobuhiro Aoki Mariko Takada Shuji Yamamoto Naoya Kimoto Mikio Fujita Akihiko Okada Chiharu Kawanami Yukinobu Takimoto Akio Orino 《Nihon Shokakibyo Gakkai zasshi》2007,104(10):1498-1503
A 77-year-old man, who underwent segmental pancreatectomy for intraductal papillary mucinous adenoma in 2001, was referred to our hospital with complaints of hematemesis and melena on January, 2004. Emergency upper gastrointestinal endoscopy showed a pulsating submucosal protrusion in the duodenal bulb, which was identified as a gastroduodenal arterial aneurysm measuring 1.5cm on abdominal CT imaging. Transcatheter arterial embolization of the aneurysm with metallic coils was successfully performed. Periodically repeated endoscopic examination has revealed the coils protruding into the duodenal lumen without any serious complication. 相似文献
50.
Satoshi Suzuki Koji Yasuda Yuji Matsumura Takashi Kondo 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2006,54(5):225-227
We present here a rare case of left-side catamenial pneumothorax, in which endometrial tissue pleura was found on the visceral pleura histologically. A chest roentogenogram confirmed the left pneumothorax, but did not reveal bullae or any associated anomalies, in a 41-year-old woman with three documented episodes of left-side pneumothorax occurring every menstruation. Video-assisted thoracoscopic surgery revealed not only tiny holes in the diaphragm, but also a scattered small brown spots on the visceral pleura. Histological examination of the lung sections revealed the existence of endometrial tissue on the visceral pleura with disrupted pleural elastic fibers. Our case suggests that cyclic erosion of the visceral pleura by the implanted endometrial tissue caused air leakage from the lung, in addition to the most accepted concept that air is aspirated into the thoracic cavity via the abdomen through the acquired fenestration of the diaphragm. 相似文献