全文获取类型
收费全文 | 12486篇 |
免费 | 594篇 |
国内免费 | 83篇 |
专业分类
耳鼻咽喉 | 62篇 |
儿科学 | 245篇 |
妇产科学 | 130篇 |
基础医学 | 1331篇 |
口腔科学 | 249篇 |
临床医学 | 884篇 |
内科学 | 3285篇 |
皮肤病学 | 227篇 |
神经病学 | 912篇 |
特种医学 | 458篇 |
外科学 | 2250篇 |
综合类 | 59篇 |
预防医学 | 257篇 |
眼科学 | 534篇 |
药学 | 745篇 |
中国医学 | 20篇 |
肿瘤学 | 1515篇 |
出版年
2023年 | 88篇 |
2022年 | 173篇 |
2021年 | 339篇 |
2020年 | 177篇 |
2019年 | 229篇 |
2018年 | 317篇 |
2017年 | 250篇 |
2016年 | 328篇 |
2015年 | 303篇 |
2014年 | 356篇 |
2013年 | 429篇 |
2012年 | 685篇 |
2011年 | 727篇 |
2010年 | 416篇 |
2009年 | 337篇 |
2008年 | 555篇 |
2007年 | 593篇 |
2006年 | 615篇 |
2005年 | 561篇 |
2004年 | 602篇 |
2003年 | 594篇 |
2002年 | 583篇 |
2001年 | 338篇 |
2000年 | 357篇 |
1999年 | 307篇 |
1998年 | 141篇 |
1997年 | 121篇 |
1996年 | 110篇 |
1995年 | 99篇 |
1994年 | 98篇 |
1993年 | 83篇 |
1992年 | 214篇 |
1991年 | 195篇 |
1990年 | 163篇 |
1989年 | 189篇 |
1988年 | 166篇 |
1987年 | 111篇 |
1986年 | 146篇 |
1985年 | 131篇 |
1984年 | 86篇 |
1983年 | 85篇 |
1979年 | 82篇 |
1978年 | 50篇 |
1977年 | 50篇 |
1974年 | 47篇 |
1973年 | 52篇 |
1972年 | 46篇 |
1971年 | 58篇 |
1969年 | 41篇 |
1968年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Kazunori Aizawa Takeshi Hanaoka Hiroki Kasai Kaoru Kogashi Setsuo Kumazaki Jun Koyama Hiroshi Tsutsui Yoshikazu Yazaki Noboru Watanabe Osamu Kinoshita Uichi Ikeda 《Hypertension research》2006,29(2):123-128
The phosphodiesterase-5 (PDE-5) inhibitor, sildenafil, has been reported to produce sustained pulmonary vasodilatation in patients with pulmonary hypertension (PH). Recently, vardenafil, a more potent and selective PDE-5 inhibitor than sildenafil, has been approved for the treatment of erectile dysfunction. However, the long-term effects of oral vardenafil in patients with PH are unknown. We studied five consecutive patients with PH; one with primary pulmonary hypertension, two with chronic pulmonary thromboembolism, one with Eisenmenger syndrome (ventricular septal defect) and one with secondary pulmonary hypertension after a ventricular septal defect closure operation. In an acute hemodynamic trial, vardenafil (5 mg) significantly decreased both the pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR) with an increase in cardiac output. In a chronic hemodynamic trial, the maintenance dose of vardenafil (10 to 15 mg) for 3 months significantly decreased the PVR, but not the SVR, with a 20.7% reduction of the PVR/ SVR ratio. Plasma brain natriuretic peptide (BNP) levels were also significantly decreased after 3 months. This pilot study demonstrates that long-term oral vardenafil therapy may be a safe and effective treatment for patients with PH. 相似文献
3.
Yosiaki Yajima Nobutaka Takahashi Atsusi Miyazaki Ryosuke Kikuchi Keisuke Kakisaka Keisuke Oikawa Kazuhiko Sugawara Yoshiki Eda Hiroshi Naganuma Masamitsu Unagami 《Nihon Shokakibyo Gakkai zasshi》2006,103(5):515-522
From April 1989 to December 2004, we performed liver biopsy on 475 patients and obtained biopsy proven 35 cases of non-alcoholic fatty liver. Among them, 18 cases were diagnosed as non-alcoholic steatohepatitis (NASH). During the last three years, we have tried to detect NASH using ultrasonography and elevated value of serum ferritin (> 300 ng/ml). All of the eligible 7 cases biopsied during the course were diagnosed as NASH. In these 7 cases, ALT levels improved after the body weight loss accompanied by the parallel decrease of serum ferritin levels. Measurement of serum ferritin is useful in the detection of NASH but the normal value of ferritin cannot rule out the possibility of NASH. 相似文献
4.
Satoshi Iyama Yasuo Takahashi Naoaki Shintani Koshi Fujikawa Syunichi Ohkubo Yasushi Sato Tsutomu Sato Yasuhiro Sato Keisuke Ohnuma Yoshiro Niitsu 《Nihon Shokakibyo Gakkai zasshi》2006,103(10):1163-1168
We report a case of biliary cystadenocarcinoma which recurred 41 months postoperatively. A 60-year-old woman was admitted for further examination of multiple metastatic tumors and a large amount of ascites. Systemic administration of 5FU and CDDP caused her CEA level to decrease gradually and abdominal computed tomography revealed considerable reduction of the metastatic tumors and ascites. Since her general condition had improved, chemotherapy was continued in the outpatient clinic. 相似文献
5.
Shoji Kubo Hiroaki Kinoshita Kazuhiro Hirohashi Takatsugu Yamamoto 《Journal of Hepato-Biliary-Pancreatic Surgery》1995,2(1):85-89
A case of cystadenocarcinoma of the liver is reported. The patient was a 73-year-old woman in whom a tumor was detected in
the lateral segment of the liver during a health examination. Ultrasonograms and computed tomograms showed a multilocular
cystic mass. Magnetic resonance imaging (MRI) showed a multilocular lowintensity mass, including a high-intensity portion
and a portal branch compressed by the tumor. MRI with gadolinium showed an enhanced cyst wall. The cystic part of the tumor
became smaller and the solid part became larger over a 1-month period, indicating that the tumor was malignant. Subsegmentectomy
(S3) was performed and cystadenocarcinoma with cystadenoma was diagnosed by histopathological examination. Identification of
changes in the appearance of a tumor should be helpful for the differential diagnosis of cystadenoma and cystadenocarcinoma. 相似文献
6.
Basic fibroblast growth factor prevents thalamic degeneration after cortical infarction 总被引:10,自引:0,他引:10
K Yamada A Kinoshita E Kohmura T Sakaguchi J Taguchi K Kataoka T Hayakawa 《Journal of cerebral blood flow and metabolism》1991,11(3):472-478
In the focal infarction model of the rat middle cerebral artery (MCA), the thalamus of the occluded side becomes gradually atrophic, mainly because of retrograde degeneration. We determined whether basic fibroblast growth factor (bFGF) administered intracisternally could prevent this thalamic atrophy. We occluded the left MCA through a small cranial opening, and animals were then divided into two groups. One group received intracisternal injections of recombinant bFGF (1 microgram dissolved in 0.1 ml of saline with 2% rat serum) starting 1 day after occlusion and repeated once a week to a total dose of 4 micrograms by four injections. The other group received vehicle solution by the same schedule. The animals were perfused and fixed at 28 days after occlusion, and histological examination was made at the level of the caudoputamen and thalamus. In the bFGF-treated rats, the area of the posterior ventral thalamus of the occluded side was 93% of that of the contralateral side, i.e., significantly larger than in the normal saline-treated rats (75%, p less than 0.01). The infarction size was not statistically different in the two groups. Microscopic observation indicated that normal-saline-treated animals showed shrinkage and disappearance of thalamic neurons, whereas bFGF-treated groups showed preservation of thalamic neurons. Computerized analysis of the cell size substantiated this observation. To assess the effect of bFGF on astrocytes, bFGF or vehicle solution was injected into normal rats, and their histology was evaluated at 1, 2, and 4 weeks after injection. The bFGF-injected group showed a significant increase in glial fibrillary acidic protein-positive astrocytes in the brain tissue facing the ventriculocisternal system.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
7.
Y Iwasaki M Kinoshita K Ikeda K Takamiya T Shiojima 《The International journal of neuroscience》1991,59(4):253-258
Magnetic resonance imaging (MRI) of the brain was performed in 10 patients with amyotrophic lateral sclerosis (ALS) and the findings were evaluated. Four patients had asymmetrical areas of increased signal intensity in the white matter. All patients showing abnormal MRI were young, had a longer clinical course, and clinically were more disabled. These MRI abnormalities were related to the pathological changes in the central white matter of patients with ALS and possible explanations for these findings in ALS are discussed. 相似文献
8.
K Satomi Y Kinoshita S Hirakawa 《Cortex; a journal devoted to the study of the nervous system and behavior》1991,27(2):327-331
If defective cross-localization of fingertips (CLF) in callosal patients is due to a deficit in the interhemispheric transfer of somesthetic information, when the patient's eyes are open, CLF should be affected when the stimulated hand is excluded from vision, not when the responding hand is excluded from vision. In order to investigate this hypothesis, a patient with a callosal lesion was subjected to CLF with eyes closed and open. With eyes closed, the CLF score in the left-to-right direction was significantly lower than that in the right-to-left direction. With eyes open, the CLF performance in the right-to-left direction was impaired when it was the responding hand to be excluded from vision, not when it was the stimulated hand to be excluded from vision. It would, therefore, appear that the patient's CLF disturbance was not due to a somesthetic transfer deficit, but to left unilateral apraxia for the right-to-left direction errors and to left tactile finger anomia for the left-to-right direction errors. 相似文献
9.
10.