全文获取类型
收费全文 | 2399篇 |
免费 | 130篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 38篇 |
妇产科学 | 27篇 |
基础医学 | 298篇 |
口腔科学 | 70篇 |
临床医学 | 148篇 |
内科学 | 565篇 |
皮肤病学 | 41篇 |
神经病学 | 185篇 |
特种医学 | 55篇 |
外科学 | 495篇 |
综合类 | 6篇 |
预防医学 | 113篇 |
眼科学 | 23篇 |
药学 | 158篇 |
中国医学 | 1篇 |
肿瘤学 | 295篇 |
出版年
2023年 | 18篇 |
2022年 | 28篇 |
2021年 | 45篇 |
2020年 | 29篇 |
2019年 | 37篇 |
2018年 | 33篇 |
2017年 | 31篇 |
2016年 | 26篇 |
2015年 | 42篇 |
2014年 | 49篇 |
2013年 | 67篇 |
2012年 | 103篇 |
2011年 | 117篇 |
2010年 | 61篇 |
2009年 | 45篇 |
2008年 | 114篇 |
2007年 | 131篇 |
2006年 | 113篇 |
2005年 | 136篇 |
2004年 | 119篇 |
2003年 | 103篇 |
2002年 | 89篇 |
2001年 | 83篇 |
2000年 | 96篇 |
1999年 | 103篇 |
1998年 | 19篇 |
1997年 | 18篇 |
1996年 | 15篇 |
1995年 | 21篇 |
1994年 | 15篇 |
1993年 | 19篇 |
1992年 | 58篇 |
1991年 | 59篇 |
1990年 | 46篇 |
1989年 | 39篇 |
1988年 | 50篇 |
1987年 | 47篇 |
1986年 | 42篇 |
1985年 | 27篇 |
1984年 | 27篇 |
1983年 | 17篇 |
1979年 | 19篇 |
1978年 | 15篇 |
1974年 | 13篇 |
1973年 | 14篇 |
1971年 | 11篇 |
1969年 | 13篇 |
1968年 | 14篇 |
1967年 | 15篇 |
1966年 | 19篇 |
排序方式: 共有2538条查询结果,搜索用时 109 毫秒
61.
Patent ductus venosus 总被引:1,自引:0,他引:1
Nagano K Hoshino H Nishimura D Katada N Sano H Kato K 《Journal of gastroenterology and hepatology》1999,14(3):285-288
BACKGROUND: Patent ductus venosus is extremely rare with only 14 cases reported in the world literature. We present a case of patent ductus venosus. METHODS AND RESULTS: A 29-year-old male was admitted with melaena stool caused by gastric haemorrhagic ulcers. Laboratory data disclosed severe anaemia; however, liver function tests were normal. Serum ammonia was also within the normal range. Serological viral markers for hepatitis B or C were all negative. The abdominal ultrasonography and computed tomography indicated a 12 mm diameter shunt located in the left lobe of the liver, which connected the portal vein with the left hepatic vein. After treatment for gastric ulcers, percutaneous transhepatic portography was performed and an enormous shunt connecting the umbilical portion of the portal vein with the left hepatic vein was revealed. CONCLUSIONS: Histological findings of the liver biopsy showed that portal venules could not be observed in the portal areas and that no fibrosis or inflammatory cell infiltration were shown. Because of the anatomical position of the shunt, the case was diagnosed as patent ductus venosus. 相似文献
62.
Seiji Matsumoto Kazuhide Yamamoto Takuya Nagano Ryoichi Okamoto Masafumi Tagashira Naohisa Ibuki Kazuhfsa Yabushita Takao Tsuji 《Liver international》1999,19(5):399-405
Abstract: Aims/Background: Activated liver macrophages in chronic hepatitis express a high affinity receptor for IgG named FcγRI. This study was performed to find the difference in FcγRI expression between chronic hepatitis B (CHB) and C (CHC) with reference to histological activity. Methods: Consecutive patients with CHB (20 cases) and CHC (25 cases) were enrolled in the study. Inflammatory activity was evaluated using the modified histological activity index (HAI). FcγRI-positive macrophages were quantitatively measured by computer assisted morphometry. Results: Total HAI score was significantly higher in CHB than in CHC. Confluent necrosis was observed in significantly higher frequency in CHB at Stages 3–5 than in CHC. The percentage area of FcγRI-positive macrophages was significantly higher in CHB than in CHC. In CHB, the percentage area of FcγRI-positive macrophages correlated with total HAI (< 0.01) as well as the degree of confluent necrosis (< 0.01), interface hepatitis (< 0.05) and portal inflammation (< 0.05). FcγRI-positive macrophages accumulated mainly at the site of confluent necrosis. In CHC, no correlation was observed between activated macrophages and any histological categories. Conclusion: These results suggest that FcγRI-positive macrophages are associated with confluent necrosis in CHB, which is more common in CHB patients than in CHC. 相似文献
63.
Nitric oxide plays an insignificant role in direct vasodilator effects of calcium channel blockers in healthy humans 总被引:1,自引:0,他引:1
Several experimental studies have suggested that the vasodilatory effects of calcium channel blockers (CCBs) are due in part
to an endothelium-dependent mechanism. However, it remains unknown whether CCBs directly augment liberation of endothelium-derived
dilator substances such as nitric oxide (NO) in the human vasculature. The aim of this study was to examine whether CCBs of
several kinds directly increase the bioavailability of NO in forearm resistance vessels. Twenty-four healthy men (mean age
30 ± 2 years) were randomly assigned to three study groups (n = 8 in each), and each group was assigned one of three first-generation CCBs (nifedipine, nicardipine, diltiazem). Subdepressor
doses of CCBs [4, 8, 16, 24, and 36 (diltiazem only) nmol/min; for 2 min in each dose] were infused intra-arterially, and
forearm blood flow (FBF) was determined plethysmographically. After control FBF responses to CCBs had been measured, a NO
synthase inhibitor (N
G-monomethyl-l-arginine: l-NMMA) was infused intra-arterially, and the FBF response to CCBs was again determined. Further, as a positive control for
NO stimulation, acetylcholine (ACh) was also examined before and after l-NMMA in each group. Systemic blood pressure and heart rate did not change significantly during the study protocol. The FBF
responses to these CCBs did not differ before and after NO synthase inhibition by l-NMMA (FBF at maximum doses: nifedipine, 8.0 ± 0.8 vs 7.3 ± 0.7; nicardipine, 7.3 ± 1.5 vs 6.5 ± 1.3; diltiazem, 5.7 ± 0.7
vs 4.2 ± 0.7 ml/min per 100 ml: all not significant), although FBF responses to ACh were significantly reduced by l-NMMA. In conclusion, direct NO liberation does not make a significant contribution to the vasodilation associated with first-generation
CCBs in healthy human resistance vessels.
Received: July 12, 2001 / Accepted: October 19, 2001 相似文献
64.
65.
T Yamashita S Kasuya I Nagano H Ohtomo 《Kansenshōgaku zasshi. The Journal of the Japanese Association for Infectious Diseases》1992,66(9):1262-1269
We characterized 8 monoclonal antibodies (MAbs) to Karp, Kato, and Gilliam strains of Rickettsia tsutsugamushi, and analysed 17 isolates from patients with Tsutsugamushi disease using these MAbs. These were divided into 3 strain-specific (Kp/D11, Kt/2D9, and Gi/E4) and 5 cross-reactive MAbs (Kp/1F11, Kp/1C10, Kp/C6, Kt/3B2, and Kt/3C2). All MAbs recognized characteristic protein antigens using the indirect fluorescent-antibody test (IFA) and proteinase K treatment. Analysis by polyacrylamide gel electrophoresis and immunoblotting techniques revealed that Kato-specific MAb Kt/2D9 recognized a polypeptide with a molecular mass of 54 kilodalton (kDa) of the homologous strain, and cross-reactive MAbs Kp/1F11, Kp/C6, and Kt/3B2 recognized those of 46-47 kDa, 46-47 KDa, and 60 kDa, respectively to the homologous and heterologous strains. MAbs Kp/1C10 which exhibited a high IFA titer against the Karp strain and only low titers against heterologous strains recognized only the 110 kDa polypeptide of the homologous strain. MAb Kt/3C2 which reacted with both Karp and Kato strains recognized a 54 to 56 kDa polypeptide band of the two prototype strains as well as several other polypeptides, however, each molecular mass was present in only one of two strains. Testing by the plaque reduction technique showed another characteristic of MAb Kt/3C2 to neutralize both Karp and Kato Strains. Fourteen isolated strains from patients in the south and west regions of Gifu Prefecture, the Shimokoshi stain isolated in Niigata Prefecture, and Kawasaki and Kuroki stains isolated in Miyazaki Prefecture were examined for reactivities to 8 MAbs by IFA to classify their antigenicities. No isolated strains reacted with Karp-specific Kp/D11, Kato-specific Kt/2D9, or Gilliam-specific Gi/E4.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
66.
Nagano Marisa Zane Emily Grossman Ruth B. 《Journal of autism and developmental disorders》2021,51(5):1562-1583
Journal of Autism and Developmental Disorders - This study investigates the use of structural and discourse contextual cues in the interpretation of third-person pronouns by children and... 相似文献
67.
Masahiro Miyoshi Rika Komagome Setsuko Ishida Hideki Nagano Kenichi Takahashi Motohiko Okano 《Archives of virology》2013,158(4):775-784
We determined four complete nucleotide sequences of echovirus 6 (E6) isolated from an epidemic of aseptic meningitis (AM) in Hokkaido, Japan, in 2011. Phylogenetic analysis of the genes encoding viral capsid protein 1 revealed that the strains were closely related to E6 strains isolated in China in recent years, but they were distantly related to E6 strains isolated from patients with AM in Osaka Prefecture, Japan, in 2011. The genes encoding the viral protease and RNA-dependent RNA polymerase (3CD) were closely related to those of several non-E6 strains of the species Human enterovirus B isolated in China, South Korea, and Australia from 1999 to 2010, resulting in a novel cluster in the phylogenetic tree. These results suggest that the incidence of AM in Japan in 2011 was caused by at least two lineages of E6 strains, and a lineage of the 3CD gene was interspersed among different serotypic strains isolated in Western Pacific countries. 相似文献
68.
de Sousa Graziella Ribeiro Lira Régia Caroline Peixoto de Almeida Magalhães Taciani da Silva Keteryne Rodrigues Nagano Luis Fernando Peinado Saggioro Fabiano Pinto Baroni Mirella Marie Suely Kazue Nagahashi Oba-Shinjo Sueli Mieko Brandelise Silvia de Paula Queiroz Rosane Gomes Brassesco María Sol Scrideli Carlos Alberto Tone Luiz Gonzaga Valera Elvis Terci 《Journal of molecular medicine (Berlin, Germany)》2021,99(8):1101-1113
Journal of Molecular Medicine - Although ependymoma (EPN) molecular subgroups have been well established by integrated high-throughput platforms, low- and middle-income countries still need... 相似文献
69.
70.
Kujiraoka T Hattori H Ito M Nanjee MN Ishihara M Nagano M Iwasaki T Cooke CJ Olszewski WL Stepanova IP Egashira T Miller NE 《Atherosclerosis》2004,176(1):57-62
We have previously shown that intravenous apolipoprotein (apo) A-I/phosphatidylcholine (apo A-I/PC) discs increase plasma high-density lipoprotein (HDL) concentration in humans. We have now studied the associated changes in two enzymes, paraoxonase (PON) and platelet-activating factor acetylhydrolase (PAF-AH) that are carried in whole or in part by HDLs, and are thought to influence atherogenesis by hydrolyzing oxidized phospholipids in lipoproteins. Apo A-I/PC discs (40 mg/kg over 4 h) were infused into eight healthy males. Although plasma apo A-I and HDL cholesterol increased on average by 178 and 158%, respectively, plasma total PON and total PAF-AH concentrations did not rise. By the end of the infusion, HDL-associated PAF-AH had increased by 0.56 +/- 0.14 microg/mL (mean +/- S.D., P < 0.01), and nonHDL-associated PAF-AH had decreased by 0.84 +/- 0.11 microg/mL (P < 0.05). These changes were accompanied by an increase in the HDL-associated PAF-AH/apo A-I ratio from 0.19 to 0.35 (P < 0.05), and by a decrease in the nonHDL-associated PAF-AH/apo B ratio from 2.1 to 1.4 (P < 0.05). No changes in PON or PAF-AH concentrations were detected in prenodal lymph (tissue fluid), collected continuously from the leg. Our results show that the total concentrations of PON and PAF-AH in plasma are uninfluenced by plasma HDL concentration. PAF-AH transfers readily between HDLs and LDLs in vivo, and its distribution between them is determined partly by their relative concentrations and partly by HDL composition. 相似文献