全文获取类型
收费全文 | 20504篇 |
免费 | 1012篇 |
国内免费 | 130篇 |
专业分类
耳鼻咽喉 | 262篇 |
儿科学 | 339篇 |
妇产科学 | 236篇 |
基础医学 | 2191篇 |
口腔科学 | 464篇 |
临床医学 | 1294篇 |
内科学 | 5280篇 |
皮肤病学 | 539篇 |
神经病学 | 1503篇 |
特种医学 | 733篇 |
外科学 | 3563篇 |
综合类 | 102篇 |
一般理论 | 1篇 |
预防医学 | 646篇 |
眼科学 | 264篇 |
药学 | 1553篇 |
中国医学 | 44篇 |
肿瘤学 | 2632篇 |
出版年
2023年 | 166篇 |
2022年 | 312篇 |
2021年 | 501篇 |
2020年 | 297篇 |
2019年 | 395篇 |
2018年 | 538篇 |
2017年 | 362篇 |
2016年 | 492篇 |
2015年 | 505篇 |
2014年 | 637篇 |
2013年 | 709篇 |
2012年 | 1238篇 |
2011年 | 1325篇 |
2010年 | 718篇 |
2009年 | 576篇 |
2008年 | 1081篇 |
2007年 | 1138篇 |
2006年 | 1094篇 |
2005年 | 1119篇 |
2004年 | 1036篇 |
2003年 | 895篇 |
2002年 | 967篇 |
2001年 | 494篇 |
2000年 | 469篇 |
1999年 | 461篇 |
1998年 | 231篇 |
1997年 | 194篇 |
1996年 | 164篇 |
1995年 | 146篇 |
1994年 | 144篇 |
1993年 | 111篇 |
1992年 | 289篇 |
1991年 | 276篇 |
1990年 | 271篇 |
1989年 | 266篇 |
1988年 | 247篇 |
1987年 | 227篇 |
1986年 | 181篇 |
1985年 | 199篇 |
1984年 | 151篇 |
1983年 | 129篇 |
1982年 | 53篇 |
1981年 | 50篇 |
1980年 | 48篇 |
1979年 | 94篇 |
1978年 | 64篇 |
1977年 | 64篇 |
1974年 | 57篇 |
1971年 | 49篇 |
1967年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Naoki Sugawara Koji Arizono Toshiichi Kitajima Hideaki Inoue Yu-Rong Lai 《Archives of toxicology》1997,71(5):336-339
A new mutant, the Eisai hyperbilirubinemic (EHB) rat, shows no inherent expression of the canalicular isoform of the multidrug
resistance protein (cMrp) in the liver. It has defective biliary secretion of organic anions such as bilirubin glucuronides,
bromosulfophthalein (BSP), cysteinyl leukotrienes, glutathione (GSH) and bile acid sulfate and glucuronides. When rats were
injected intravenously with CdCl2, biliary excretion of Cd over 30 min was 0.28% and 0.004% of the total dose in Sprague-Dawley (SD) and EHB rats, respectively.
Six SD rats and five EHB rats were fed a diet containing Cd. Bile Cd was detected at the level of 2 ng/20 min in SD rats,
but not in EHB rats. There was no significant difference of hepatic Cd concentration between SD and EHB rats. Furthermore,
there were no significant differences of renal and intestinal Cd, and hepatic and renal metallothionein (MT) concentrations
between the SD and EHB groups. Biliary excretion of reduced-GSH for 20 min was 1.3 ± 0.3 mg and 3.6 ± 0.9 μg in SD and EHB
rats, respectively. Our results suggest that hepatobiliary excretion of exogenous Cd is mediated mainly via carrier transport,
including a cMrp or GSH carrier, but that the lack of the transport pathway does not contribute to abnormal accumulation of
Cd in the liver.
Received: 12 August 1996 / Accepted 7 November 1996 相似文献
62.
Limited vertical skin incision for median sternotomy. 总被引:4,自引:0,他引:4
S Tatebe S Eguchi H Miyamura S Nakazawa H Watanabe M Sugawara J Hayashi K Date S Nakagawa 《The Annals of thoracic surgery》1992,54(4):787-788
The cosmetic deformity of the vertical skin incision for median sternotomy was decreased by using a mechanical traction system to increase exposure at the superior margin of a shorter wound. The limited vertical skin incision did not impede technical surgical maneuvers and produced a scar that was more acceptable than submammary incision or right anterior thoracotomy. The limited skin incision is especially useful in young women with congenital heart disease. 相似文献
63.
Y. Tsutsumi T. Kihira S. Tsunoda T. Kanamori S. Nakagawa T. Mayumi 《British journal of cancer》1995,71(5):963-968
This study was conducted to increase the anti-tumour potency and reduce the toxic side-effects of tumour necrosis factor alpha (TNF-alpha). Natural human TNF-alpha was chemically conjugated with monomethoxy polyethylene glycol (PEG) using succinimidyl coupling of lysine amino groups of TNF-alpha. The number-average molecular weight of PEG-modified TNF-alpha (PEG-TNF-alpha) increased with an increase in the reaction time and the initial molar ratio of PEG relative to TNF-alpha. The resulting modified TNF-alpha was separated into fractions of various molecular weights. The specific activity of separated PEG-TNF-alpha s relative to that of native TNF-alpha gradually decreased with an increase in the degree of PEG modification, but the plasma half-life was drastically increased with the increase in molecular weight of modified TNF-alpha. PEG-TNF-alpha s, in which 29% and 56% of lysine residues were coupled to PEG, had anti-tumour activity approximately 4 and 100 times greater than unmodified TNF-alpha in the murine Meth-A fibrosarcoma model. Extensive PEG modification did not increase its in vivo activity. A high dose of unmodified TNF-alpha induced toxic side-effects, but these were not observed with the modified TNF-alpha s. Optimal PEG modification of TNF-alpha markedly increased its bioavailability and may facilitate its potential anti-tumour therapeutic use. 相似文献
64.
Mucoadhesive Microspheres Containing Amoxicillin for Clearance of Helicobacter pylori 总被引:5,自引:0,他引:5 下载免费PDF全文
Naoki Nagahara Yohko Akiyama Masafumi Nakao Mayumi Tada Megumi Kitano Yasuyuki Ogawa 《Antimicrobial agents and chemotherapy》1998,42(10):2492-2494
In an effort to augment the anti-Helicobacter pylori effect of amoxicillin, mucoadhesive microspheres, which have the ability to reside in the gastrointestinal tract for an extended period, were prepared. The microspheres contained the antimicrobial agent and an adhesive polymer (carboxyvinyl polymer) powder dispersed in waxy hydrogenated castor oil. The percentage of amoxicillin remaining in the stomach both 2 and 4 h after oral administration of the mucoadhesive microspheres to Mongolian gerbils under fed conditions was about three times higher than that after administration in the form of a 0.5% methylcellulose suspension. The in vivo clearance of H. pylori following oral administration of the mucoadhesive microspheres and the 0.5% methylcellulose suspension to infected Mongolian gerbils was examined under fed conditions. The mucoadhesive microspheres and the 0.5% methylcellulose suspension both showed anti-H. pylori effects in this experimental model of infection, but the required dose of amoxicillin was effectively reduced by a factor of 10 when the mucoadhesive microspheres were used. In conclusion, the mucoadhesive microspheres more effectively cleared H. pylori from the gastrointestinal tract than the 0.5% methylcellulose suspension due to the prolonged gastrointestinal residence time resulting from mucoadhesion. A dosage form consisting of mucoadhesive microspheres containing an appropriate antimicrobial agent should be useful for the eradication of H. pylori. 相似文献
65.
Mariko Kobayashi Yukihiro Takahashi Makoto Ando Naoki Wada Masamitsu Murata Toshio Kikuchi 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2005,53(12):635-637
A 6 month-old male infant (weight: 4.5 kg) with congenital aortic stenosis underwent aortic valve replacement with a pulmonary
autograft (Ross procedure). The right ventricular outflow tract (RVOT) was reconstructed with a polytetrafluoroethylene (PTFE)-valved
equine pericardial conduit. At the age of 5, re-RVOT reconstruction with an equine pericardial patch bearing a PTFE monocusp
was required because of severe pulmonary stenosis resistant to 2 attempts of percutaneous transluminal pulmonary valvotomy.
Currently, at the age of 8, the degree of aortic regurgitation is trivial and the pulmonary autograft is free of functional
deterioration despite somatic growth. 相似文献
66.
Eiji Nakagawa Hideo Yamanouchi Norio Sakuragawa Sachio Takashima 《Brain & development》1994,16(6):488-490
We report a case of acute cerebellar ataxia (ACA) with discrete paleocerebellar clinical symptoms who underwent serial cranial magnetic resonance images not only with conventional spin echo sequences but also fluid attenuated inversion recovery (FLAIR) sequences. The images with the latter sequences demonstrated more conspicuously the high signal intensity lesions in the superior cerebellar vermis and cerebellar peduncle than those with the former sequences. In the convalescent phase, the lesions became markedly atrophic. Thus, the causative lesions for ACA were demonstrated on MRI, and FLAIR provided clear images of the lesion in the vermis. 相似文献
67.
Naoki Hori Hakuo Takahashi‡ Takeshi Okanoue Yoshihiko Sawa Takashi Mori Shiro Takami Manabu Yoshimura† Kei Kashima 《Clinical and experimental pharmacology & physiology》1995,22(8):506-511
1. Endothelium-derived nitric oxide (NO) is a potent vasodilator. Because the body oxidizes it to nitrate ions, NO3-, measurement of the serum concentration and the urinary excretion of NO3- may be an index for endogenous NO. We investigated the role of NO on hyperdynamic circulation in cirrhotic and partial portal vein-ligated rats by measuring NO3. 2. Liver cirrhosis was induced by administration of thioacetamide. Systemic and splanchnic haemodynamics and splenic-systemic shunting were determined by tracer microspheres. The concentration of NO3- was measured by using high-performance liquid chromatography with an anion-column. 3. We found that systemic and splanchnic hyperdynamic circulation existed to almost the same extent in cirrhotic and in portal vein-ligated rats as compared to the controls and sham-operated rats, respectively. Splenic-systemic shunting was markedly greater in portal vein-ligated rats than in cirrhotic rats. 4. Serum NO3- levels and urinary excretion of NO3- in cirrhotic rats tended to increase as compared to the controls. On the other hand, the levels in portal vein-ligated rats were significantly increased as compared to those of the sham-operated rats, and were significantly and negatively correlated to the splanchnic arterial resistance and total vascular resistance. The amount of urinary excretion of NO3- significantly correlated to splenic-systemic shunting (r = 0.61, P<0.05) only in portal vein-ligated rats. 5. We suggest that these high levels of NO3- in portal vein-ligated rats relate to the extensive formation of porto-collateral vasculature or acute changes in systemic and splanchnic haemodynamics due to portal vein-ligation. 相似文献
68.
69.
S Kitagawa M Nakagawa T Yamada Y Mori H Simizu S Rin H Kurumaya 《Nihon Geka Gakkai zasshi》1990,91(8):1001-1010
Xanthogranulomatous cholecystitis (XGC) is an uncommon lesion which may form a tumor-like mass in inflamed gallbladders. In a review of 44 cases there were 40 associated with gallstones which had been incarcerated in the neck of the gallbladder, 10 with past histories of abdominal surgeries, 15 with diabetes mellitus, three with carcinomas in the neck of the gallbladder and four with carcinomas in the other organs. Radiologically the differential diagnosis of gallbladder cancer and XGC was difficult in several cases. Thirty five cases of XGC have been diagnosed as chronic cholecystitis and 7 have been mistaken for feature of XGC in the contrast enhancement CT that is, detection of an intramural low density mass with continuously enhanced internal membraneous layer of the gallbladder wall. In view of the clinico-pathological findings of XGC, the lesions appear to result from intramural extravasation of bile and subsequent xanthogranulomatous reaction under obstructive conditions in the neck of the gallbladder. We conclude that XGC is not an uncommon special type of cholecystitis but an accompanied lesion sometimes seen in a kind of cholecystitis. 相似文献
70.