全文获取类型
收费全文 | 3433篇 |
免费 | 148篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 52篇 |
妇产科学 | 48篇 |
基础医学 | 338篇 |
口腔科学 | 89篇 |
临床医学 | 183篇 |
内科学 | 1229篇 |
皮肤病学 | 20篇 |
神经病学 | 195篇 |
特种医学 | 230篇 |
外科学 | 495篇 |
综合类 | 13篇 |
预防医学 | 59篇 |
眼科学 | 19篇 |
药学 | 178篇 |
中国医学 | 2篇 |
肿瘤学 | 449篇 |
出版年
2023年 | 32篇 |
2022年 | 52篇 |
2021年 | 87篇 |
2020年 | 43篇 |
2019年 | 54篇 |
2018年 | 70篇 |
2017年 | 59篇 |
2016年 | 58篇 |
2015年 | 72篇 |
2014年 | 113篇 |
2013年 | 121篇 |
2012年 | 237篇 |
2011年 | 206篇 |
2010年 | 110篇 |
2009年 | 103篇 |
2008年 | 162篇 |
2007年 | 185篇 |
2006年 | 180篇 |
2005年 | 186篇 |
2004年 | 180篇 |
2003年 | 121篇 |
2002年 | 142篇 |
2001年 | 66篇 |
2000年 | 65篇 |
1999年 | 82篇 |
1998年 | 58篇 |
1997年 | 37篇 |
1996年 | 39篇 |
1995年 | 37篇 |
1994年 | 39篇 |
1993年 | 41篇 |
1992年 | 81篇 |
1991年 | 51篇 |
1990年 | 56篇 |
1989年 | 47篇 |
1988年 | 41篇 |
1987年 | 42篇 |
1986年 | 34篇 |
1985年 | 33篇 |
1984年 | 25篇 |
1983年 | 23篇 |
1982年 | 14篇 |
1981年 | 17篇 |
1980年 | 12篇 |
1979年 | 11篇 |
1978年 | 11篇 |
1977年 | 9篇 |
1976年 | 7篇 |
1974年 | 10篇 |
1973年 | 9篇 |
排序方式: 共有3609条查询结果,搜索用时 15 毫秒
91.
Shoichiro Sumi MD Dr. Kazutomo Inoue MD Masafumi Kogire MD Ryuichiro Doi MD Mitsutoshi Yun MD Hiromu Kaji MD Ryo Hosotani MD Masaki Fujimura MD Kotaro Uchida MD Shinya Kiyama PhD Kouki Kitagawa PhD Haruaki Yajima PhD Nobutaka Fujii PhD Takayoshi Tobe MD 《Digestive diseases and sciences》1991,36(11):1523-1528
This study examined the effect of synthetic porcine neuropeptide Y on the splanchnic blood flows and the exocrine pancreatic secretion in dogs. Graded doses of neuropeptide Y (0.1–5 g/kg, intravenous) caused dose-dependent reduction of the secretin-stimulated exocrine pancreatic secretion and of the blood flows in the superior mesenteric artery, the portal vein, and the pancreatic tissue. Neuropeptide Y at 5 g/kg reduced the blood flows to 45.9±13.3% (superior mesenteric artery), 63.0±10.5% (portal vein), and 77.9±4.8% (pancreatic tissue), respectively. This dose also reduced secretin-stimulated pancreatic juice volume and CCK-8 plus secretin-stimulated protein output to 65.2±9.3 and 63.3±14.0%, respectively. This study shows a potent vasoconstrictor effect of neuropeptide Y on splanchnic vessels. Neuropeptide Y also inhibited exocrine pancreatic secretion in a significant correlation with the reduction in pancreatic tissue blood flow, which suggests that reduction in the blood flow may be one of the possible mechanisms of the inhibitory action of neuropeptide Y on exocrine secretion.This work was supported by a grant from the Ministry of Education, Japan (A-61440060). 相似文献
92.
BACKGROUND: Past studies have measured and described the length of life with disability before death, but there has been no study of the relationship between modifiable lifestyle factors and duration of disability. OBJECTIVE: To examine whether there are modifiable factors influencing the length of life with disability before death. METHODS: The study was designed as a retrospective observation of the deceased who had earlier been enrolled in a prospective cohort study.During the follow-up period (1996-1999), we documented 781 deaths among those who were 70-79 years of age at the baseline survey in 1994 (n=10,216). In 2000, we interviewed family members of the deceased about the duration of the subjects' disability before death (n=655). RESULTS: The median duration of disability before death was approximately 6 months. Both higher Body Mass Index (BMI) and shorter time spent walking were significantly associated with an increased risk of long-term disability (more than 6 months). The odds ratios of long-term disability were 1.3 in those with BMI 20-25 and 2.1 in those with BMI>25, compared with BMI<20. The odds ratios of long-term disability were 1.3 in those walking for 0.5-0.9 h/day and 1.7 in those walking for <0.5 h/day, compared with those walking for >1.0 h/day. These relationships were unchanged after stratification for causes of death. CONCLUSION: Weight control and walking in later life may shorten the length of life with disability before death. 相似文献
93.
Hiroshi Ashida M.D. Yoshinao Kotoura M.D. Kazumitsu Takagi M.D. Yoshio Ishikawa M.D. Joji Utsunomiya M.D. 《The American journal of gastroenterology》1989,84(1):71-74
We report a case of severe hemolysis after distal splenorenal shunt. Hemolysis was suddenly recognized at the time splenorenal venous anastomosis was completed, and it continued on the operative day and the first postoperative day. After the shunt, the intraoperative splenic venous blood flow was approximately double its previous level, as measured by electromagnetic flowmeter. Angiographic partial splenic embolization was performed on the second postoperative day, and then hemolysis stopped suddenly. This suggested that hemolysis after distal splenorenal shunt was related to increased splenic blood flow and acceleration of erythrocyte destruction. 相似文献
94.
95.
96.
97.
Cheng-Tse Wu Ahmed I. A. Soliman Toru Utsunomiya Takashi Ichii Hiroyuki Sugimura 《RSC advances》2019,9(55):32313
Formation of precise and high-resolution silica micropatterns on polymer substrates is of importance in surface structuring for flexible device fabrication of optics, microelectronic, and biotechnology. To achieve that, substrates modified with affinity-patterns serve as a strategy for site-selective deposition. In the present paper, vacuum ultraviolet (VUV) treatment is utilized to achieve spatially-controlled surface functionalization on a cyclo-olefin polymer (COP) substrate. An organosilane, 2,4,6,8-tetramethylcyclotetrasiloxane (TMCTS), preferentially deposits on the functionalized regions. Well-defined patterns of TMCTS are formed with a minimum feature of ∼500 nm. The secondary VUV/(O)-treatment converts TMCTS into SiOx, meanwhile etches the bare COP surface, forming patterned SiOx/COP microstructures with an average height of ∼150 nm. The resulting SiOx patterns retain a good copy of TMCTS patterns, which are also consistent with the patterns of photomask used in polymer affinity-patterning. The high quality SiOx patterns are of interests in microdevice fabrication, and the hydrophilicity contrast and adjustable heights reveal their potential application as a “stamp” for microcontact printing (μCP) techniques.Patterned surface treatment on a polymer substrate is carried out by 172 nm VUV through a photomask. TMCTS pattern formation is guided by the resulting affinity-pattern. The secondary VUV treatment converted TMCTS patterns into silica patterns. 相似文献
98.
Yoshihiko Hangai Hiroto Kamada Takao Utsunomiya Soichiro Kitahara Osamu Kuwazuru Nobuhiro Yoshikawa 《Materials》2014,7(3):2382-2394
Al foam has been used in a wide range of applications owing to its light weight, high energy absorption and high sound insulation. One of the promising processes for fabricating Al foam involves the use of a foamable precursor. In this study, ADC12 Al foams with porosities of 67%–78% were fabricated from Al alloy die castings without using a blowing agent by the friction stir processing route. The pore structure and tensile properties of the ADC12 foams were investigated and compared with those of commercially available ALPORAS. From X-ray computed tomography (X-ray CT) observations of the pore structure of ADC12 foams, it was found that they have smaller pores with a narrower distribution than those in ALPORAS. Tensile tests on the ADC12 foams indicated that as their porosity increased, the tensile strength and tensile strain decreased, with strong relation between the porosity, tensile strength, and tensile strain. ADC12 foams exhibited brittle fracture, whereas ALPORAS exhibited ductile fracture, which is due to the nature of the Al alloy used as the base material of the foams. By image-based finite element (FE) analysis using X-ray CT images corresponding to the tensile tests on ADC12 foams, it was shown that the fracture path of ADC12 foams observed in tensile tests and the regions of high stress obtained from FE analysis correspond to each other. Therefore, it is considered that the fracture behavior of ADC12 foams in relation to their pore structure distribution can be investigated by image-based FE analysis. 相似文献
99.
100.
Case series of 17 patients with cholangiocarcinoma among young adult workers of a printing company in Japan
下载免费PDF全文
![点击此处可从《Journal of hepato-biliary-pancreatic sciences》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Shoji Kubo Yasuni Nakanuma Shigekazu Takemura Chikaharu Sakata Yorihisa Urata Akinori Nozawa Takayoshi Nishioka Masahiko Kinoshita Genya Hamano Hiroaki Terajima Gorou Tachiyama Yuji Matsumura Terumasa Yamada Hiromu Tanaka Shoji Nakamori Akira Arimoto Norifumi Kawada Masahiro Fujikawa Hiromitsu Fujishima Yasuhiko Sugawara Shogo Tanaka Hideyoshi Toyokawa Yuko Kuwae Masahiko Ohsawa Shinichiro Uehara Kyoko Kogawa Sato Tomoshige Hayashi Ginji Endo 《Journal of hepato-biliary-pancreatic sciences》2014,21(7):479-488