全文获取类型
收费全文 | 45751篇 |
免费 | 2131篇 |
国内免费 | 199篇 |
专业分类
耳鼻咽喉 | 707篇 |
儿科学 | 767篇 |
妇产科学 | 754篇 |
基础医学 | 6060篇 |
口腔科学 | 1286篇 |
临床医学 | 3144篇 |
内科学 | 10844篇 |
皮肤病学 | 606篇 |
神经病学 | 3811篇 |
特种医学 | 1582篇 |
外科学 | 8068篇 |
综合类 | 195篇 |
一般理论 | 2篇 |
预防医学 | 1643篇 |
眼科学 | 712篇 |
药学 | 3715篇 |
中国医学 | 83篇 |
肿瘤学 | 4102篇 |
出版年
2023年 | 223篇 |
2022年 | 459篇 |
2021年 | 801篇 |
2020年 | 408篇 |
2019年 | 564篇 |
2018年 | 678篇 |
2017年 | 525篇 |
2016年 | 643篇 |
2015年 | 701篇 |
2014年 | 925篇 |
2013年 | 1230篇 |
2012年 | 1990篇 |
2011年 | 2112篇 |
2010年 | 1199篇 |
2009年 | 1017篇 |
2008年 | 1986篇 |
2007年 | 2189篇 |
2006年 | 2151篇 |
2005年 | 2129篇 |
2004年 | 2075篇 |
2003年 | 2117篇 |
2002年 | 2020篇 |
2001年 | 1665篇 |
2000年 | 1814篇 |
1999年 | 1563篇 |
1998年 | 561篇 |
1997年 | 473篇 |
1996年 | 436篇 |
1995年 | 367篇 |
1994年 | 331篇 |
1993年 | 305篇 |
1992年 | 1151篇 |
1991年 | 958篇 |
1990年 | 944篇 |
1989年 | 979篇 |
1988年 | 856篇 |
1987年 | 859篇 |
1986年 | 806篇 |
1985年 | 786篇 |
1984年 | 550篇 |
1983年 | 449篇 |
1982年 | 245篇 |
1979年 | 490篇 |
1978年 | 285篇 |
1977年 | 260篇 |
1974年 | 237篇 |
1972年 | 214篇 |
1971年 | 233篇 |
1969年 | 234篇 |
1968年 | 218篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Tsugawa T Shinohara R Nagasaka A Nakano I Takeda F Nagata M Oda N Sawai Y Hayakawa N Suzuki A Itoh M 《The Journal of endocrinology》2004,181(3):429-435
An accelerated polyol pathway in diabetes contributes to the development of diabetic complications. To elucidate diabetic nephropathy involving also renal tubular damage, we measured urinary sorbitol concentration concomitantly with urinary N-acetyl-D-glucosaminidase (NAG) excretion in WBN-kob diabetic rats.Twenty-four-hour urinary sorbitol concentrations increased in the diabetic rats in parallel with whole blood sorbitol concentrations. An increase in 24-h urinary NAG excretion coincided with the elevated urinary sorbitol levels in the diabetic rats. The administration of epalrestat, an aldose reductase inhibitor, reduced the increased whole blood and urinary sorbitol concentrations and urinary NAG excretion concomitantly with renal aldose reductase inhibition in the diabetic rats.These results indicate that diabetic nephropathy involves distorted cell function of renal tubules, and that treatment with epalrestat may prevent at least the progress of the nephropathy. 相似文献
992.
Shimizu A 《General and comparative endocrinology》2003,131(3):310-324
Mummichog, a spring and summer spawning teleost, were exposed to various photoperiod and temperature conditions to investigate the environmental regulation of the annual reproductive cycle. In early spring, latter phases of gonadal development (vitellogenesis in females and active spermatogenesis in males) were effectively accelerated by warm temperature (16 degrees C) regardless of the photoperiod (11L or 16L), although internal factor(s) may be concerned with triggering the initiation of the development. In late summer, intense gonadal regression which leads to the termination of the spawning period was accelerated by a short day length (=13L) in both yearlings and underyearlings. In underyearlings, however high water temperature and internal factor(s) may also be concerned. In early autumn, early phases of gonadal development (growth of cortical alveolus stage oocytes in females and basal spermatogenesis in males) were induced by moderate or lower temperatures (=22 degrees C) even under a short day length (11L). From the middle of autumn to early winter, this fish is probably in the "refractory period," and did not progress to the latter phases even under adequate temperature and long day length conditions (22 degrees C-16L). Mummichog showed a probable circa-annual rhythm of gonadal activity under constant temperature and photoperiod conditions (22 degrees C-16L): this rhythm may be the basis of the trigger of the gonadal development prior to the spawning period, the termination of the spawning period in underyearlings, and the occurrence of the "refractory period" during autumn. Plasma concentrations of estradiol-17beta in females and testosterone in males correlated well with the gonadal development during early spring and the regression during late summer. However, there was no correlation between plasma steroid levels and the degree of progress during the early phases of gonadal development in autumn, suggesting other factor such as direct action of GtH(s) or mediating substance other than sex steroids for these phases. 相似文献
993.
994.
Virus-associated hemophagocytic syndrome in an international traveler as a differential diagnosis of SARS 总被引:3,自引:0,他引:3
During the epidemic of severe acute respiratory syndrome in 2003, a 27-year- old Japanese woman presented a high fever and acute respiratory distress with pulmonary infiltrates after traveling to a high-risk area. An alternative diagnosis was made as Epstein-Barr virus-associated hemophagocytic syndrome, based on the proliferation of macrophages with hemophagocytosis in the bone marrow and Epstein-Barr viral marker profiles. Virus-associated hemophagocytic syndrome in an international traveler should be included in the differential diagnosis of severe acute respiratory syndrome. 相似文献
995.
Makoto Seki Akio Yanagisawa Eiji Ninomiya Yasuro Ninomiya Hirotoshi Ohta Akio Saiura Junji Yamamoto Toshiharu Yamaguchi Akiko Aruga Keiko Yamada Koichi Takano Rikiya Fujita Masayuki Ikeda Keiko Sasaki Yo Kato 《Journal of hepato-biliary-pancreatic sciences》2005,12(3):254-262
Background/Purpose
Between 1988 and 2003, 38 patients underwent biliary resection for pancreaticobiliary maljunction (PBM). We reviewed the histopathologic findings for the surgically resected specimens to compare the clinical and pathologic features and assess the relationship between changes in the background biliary epithelium and the development of neoplasms.Methods
Papillary hyperplasia (PHP) seen in the biliary epithelium of patients with PBM, was classified into grades 0–III in the gallbladder and grades 0–II in the extrahepatic bile duct, according to the extent, and was assessed for links with tumors in the same specimens.Results
The incidence of gallbladder carcinoma was 13/21 in grades I–II, versus 0/16 in grade III, while the incidence of bile duct carcinoma was 4/20 in grade I versus 0/5 in grade II. Furthermore, these incidences for patients below age 50 years and age 50 or older were 1/18 versus 12/20, and 0/14 versus 6/17, respectively.Conclusions
PHP of the biliary epithelium in PBM patients is an important precursor lesion, especially for gallbladder cancer, and the risk becomes greater with age, regardless of the type of pancreatobiliary junction (PBJ) and its location in the biliary tract. 相似文献996.
Eiko Hasegawa Masahiro Kobayashi Yusuke Kawamura Hiromi Yatsuji Hitomi Sezaki Tetsuya Hosaka Norio Akuta Fumitaka Suzuki Yoshiyuki Suzuki Yasuji Arase Kenji Ikeda Hiromitsu Kumada 《Hepatology research》2007,37(10):793-800
Background: We assessed the efficacy and anticarcinogenic effects of interferon (IFN) therapy in patients with hepatitis C virus (HCV)-related cirrhosis. Methods: The study subjects were 123 Japanese patients with HCV-related cirrhosis with genotype 1b low viral load or genotype 2 who received IFN from 1989 to 2005 (18 patients continue to receive IFN therapy). They included 81 men and 42 women aged 29-74 years (median, 56 years). Results: Univariate analysis identified four parameters that significantly influenced SVR; viral load (low HCV concentration, P < 0.001), duration of IFN therapy (>/= 52 weeks, P = 0.029), daily dose of IFN (>/= 6 million units, P = 0.018), induction therapy (presence, P = 0.010) and choline esterase (> 1.0 DeltapH, P = 0.037). Multivariate analysis identified viral load (risk ratio = 6.329, P < 0.001) and daily dose of IFN (risk ratio = 2.62, P = 0.042) as two independent parameters thatinfluenced SVR. During the observation period, newly developed hepatocellular carcinoma (HCC) was detected in 22 patients. The rates of development of HCC in patients with SVR were 5.8% at the fifth year and 10.3% at the 10th year, compared with 25.8% at the fifth year and 42.5% at the 10th year in non-SVR patients. Multivariate analysis showed that IFN efficacy (SVR) was the only independent factor of hepatocarcinogenesis (hazard ratio: 0.185, 95% confidence interval: 0.042-0.810, P = 0.025) Conclusion: Among patients with HCV-related cirrhosis, the rate of development of HCC is significantly less in patients with SVR. 相似文献
997.
M Naruse K Naruse T Nishikawa I Yoshihara K Ohsumi N Suzuki R Demura H Demura 《The Journal of clinical endocrinology and metabolism》1992,74(5):968-972
Endothelin (ET), originally discovered in vascular endothelial cells, has also been demonstrated in nonvascular tissues. The present study was undertaken to elucidate the presence of ET in the human pituitary. The avidin-biotin complex method with antiserum to ET-1 (and ET-2) or ET-3 was used to identify ET in human pituitaries obtained by autopsy. ET-3 immunoreactivity was found in the cytoplasm of large ovoid cells of the anterior pituitary. Using the double staining method, the cells containing ET-3 immunoreactivity were differentiated from cells containing ACTH, TSH beta, GH, PRL, and protein S-100. By staining with anti-LH beta antiserum in adjacent sections and using the double staining method, the cells were identified as gonadotrophs. No staining was observed in the posterior pituitary. In addition, no ET-1 (and ET-2) immunoreactivity was detected. The specific localization of ET-3 immunoreactivity in the gonadotrophs of the human pituitary suggests a possible role of ET-3 in the regulation of anterior pituitary function. 相似文献
998.
999.
1000.