全文获取类型
收费全文 | 3838篇 |
免费 | 178篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 72篇 |
妇产科学 | 40篇 |
基础医学 | 509篇 |
口腔科学 | 89篇 |
临床医学 | 234篇 |
内科学 | 988篇 |
皮肤病学 | 18篇 |
神经病学 | 324篇 |
特种医学 | 113篇 |
外科学 | 827篇 |
综合类 | 6篇 |
预防医学 | 103篇 |
眼科学 | 15篇 |
药学 | 301篇 |
中国医学 | 3篇 |
肿瘤学 | 366篇 |
出版年
2023年 | 10篇 |
2022年 | 19篇 |
2021年 | 39篇 |
2020年 | 30篇 |
2019年 | 45篇 |
2018年 | 46篇 |
2017年 | 41篇 |
2016年 | 40篇 |
2015年 | 63篇 |
2014年 | 71篇 |
2013年 | 91篇 |
2012年 | 125篇 |
2011年 | 142篇 |
2010年 | 80篇 |
2009年 | 69篇 |
2008年 | 137篇 |
2007年 | 160篇 |
2006年 | 162篇 |
2005年 | 183篇 |
2004年 | 167篇 |
2003年 | 176篇 |
2002年 | 188篇 |
2001年 | 154篇 |
2000年 | 162篇 |
1999年 | 198篇 |
1998年 | 64篇 |
1997年 | 58篇 |
1996年 | 78篇 |
1995年 | 65篇 |
1994年 | 56篇 |
1993年 | 39篇 |
1992年 | 144篇 |
1991年 | 137篇 |
1990年 | 129篇 |
1989年 | 114篇 |
1988年 | 132篇 |
1987年 | 81篇 |
1986年 | 78篇 |
1985年 | 69篇 |
1984年 | 65篇 |
1983年 | 28篇 |
1982年 | 11篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1979年 | 26篇 |
1978年 | 10篇 |
1977年 | 14篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1968年 | 2篇 |
排序方式: 共有4031条查询结果,搜索用时 15 毫秒
121.
Shuhei Nishiguchi Hirayuki Enomoto Nobuhiro Aizawa Hiroki Nishikawa Yukio Osaki Yasuhiro Tsuda Kazuhide Higuchi Kazuichi Okazaki Toshihito Seki Soo Ryang Kim Yasushi Hongo Hisato Jyomura Naoshi Nishida Masatoshi Kudo 《Journal of gastroenterology》2014,49(3):492-501
Background
We conducted a multicenter randomized clinical trial to determine the optimal treatment strategy against chronic hepatitis C virus (HCV) with genotype 1b and a high viral load (G1b/high).Methods
The study subjects included 153 patients with G1b/high. Patients were initially treated with PEG-IFNα-2a alone and then randomly assigned to receive different treatment regimens. Ribavirin (RBV) was administered to all patients with HCV RNA at week 4. Patients negative for HCV RNA at week 4 were randomly assigned to receive PEG-IFNα-2a (group A) or PEG-IFNα-2a/RBV (group B). Patients who showed HCV RNA at week 4 but were negative at week 12 were randomly assigned to receive weekly PEG-IFNα-2a (group C) or biweekly therapy (group D). Patients who showed HCV RNA at week 12 but were negative at week 24 were randomly assigned to receive PEG-IFNα-2a/RBV (group E) or PEG-IFNα-2a/RBV/fluvastatin (group F).Results
Overall, the rate of sustained virological response (SVR) was 46 % (70/153). The total SVR rate in the group (A, D, and F) of response-guided therapy was significantly higher than that in the group (B, C, and E) of conventional therapy [70 % (38/54) versus 52 % (32/61), p = 0.049]. Although IL28-B polymorphism and Core 70 mutation were significantly associated with efficacy, patients with rapid virological response (RVR) and complete early virological response (cEVR) achieved high SVR rates regardless of their status of IL-28B polymorphism and Core 70 mutation.Conclusion
In addition to knowing the IL-28B polymorphism and Core 70 mutation status, understanding the likelihood of virological response during treatment is critical in determining the appropriate treatment strategy. 相似文献122.
Perturbation of transforming growth factor (TGF)-β signaling in hepatocytes persistently infected with hepatitis viruses promotes both fibrogenesis and carcinogenesis (fibro-carcinogenesis). Insights into hepatocytic fibro-carcinogenesis have emerged from recent detailed analyses of context-dependent and cell type–specific TGF-β signaling processes directed by multiple phosphorylated forms (phospho-isoforms) of Smad mediators. In the course of hepatitis virus–related chronic liver diseases, chronic inflammation, ongoing viral infection, and host genetic/epigenetic alterations additively shift hepatocytic Smad phospho-isoform signaling from tumor suppression to fibro-carcinogenesis, accelerating liver fibrosis and increasing risk of hepatocellular carcinoma (HCC). After successful antiviral therapy, patients with chronic hepatitis can experience less risk of HCC occurrence by reversing Smad phospho-isoform signaling from fibro-carcinogenesis to tumor suppression. However, patients with cirrhosis can still develop HCC owing to sustained, intense fibro-carcinogenic signaling. Recent progress in understanding Smad phospho-isoform signaling should permit use of Smad phosphorylation as a tool predicting the likelihood of liver disease progression, and as a biomarker for assessing the effectiveness of interventions aimed at reducing fibrosis and cancer risk. 相似文献
123.
Shinji Tanaka Hiroshi Kashida Yutaka Saito Naohisa Yahagi Hiroo Yamano Shoichi Saito Takashi Hisabe Takashi Yao Masahiko Watanabe Masahiro Yoshida Yusuke Saitoh Osamu Tsuruta Ken-ichi Sugihara Masahiro Igarashi Takashi Toyonaga Yoichi Ajioka Masato Kusunoki Kazuhiko Koike Kazuma Fujimoto Hisao Tajiri 《Digestive endoscopy》2020,32(2):219-239
Suitable lesions for endoscopic treatment include not only early colorectal carcinomas but also several types of precarcinomatous adenomas. It is important to establish practical guidelines wherein preoperative diagnosis of colorectal neoplasia and selection of endoscopic treatment procedures are appropriately outlined and to ensure that actual endoscopic treatment is useful and safe in general hospitals when carried out in accordance with guidelines. In cooperation with the Japanese Society for Cancer of the Colon and Rectum, the Japanese Society of Coloproctology, and the Japanese Society of Gastroenterology, the Japan Gastroenterological Endoscopy Society compiled colorectal endoscopic submucosal dissection/endoscopic mucosal resection guidelines by using evidence-based methods in 2014. The first edition of these guidelines was published 5 years ago. Accordingly, we have published the second edition of these guidelines based on recent new knowledge and evidence. 相似文献
124.
Keisuke Ekino Shiro Okumura Tomoyuki Ishikawa Sakae Kitada Hiroyuki Saitoh Tetsuyuki Akao Takuji Oka Yoshiyuki Nomura Michio Ohba Takashi Shin Eiichi Mizuki 《Toxins》2014,6(6):1882-1895
Parasporin is the cytocidal protein present in the parasporal inclusion of the non-insecticidal Bacillus thuringiensis strains, which has no hemolytic activity but has cytocidal activities, preferentially killing cancer cells. In this study, we characterized a cytocidal protein that belongs to this category, which was designated parasporin-5 (PS5). PS5 was purified from B. thuringiensis serovar tohokuensis strain A1100 based on its cytocidal activity against human leukemic T cells (MOLT-4). The 50% effective concentration (EC50) of PS5 to MOLT-4 cells was approximately 0.075 μg/mL. PS5 was expressed as a 33.8-kDa inactive precursor protein and exhibited cytocidal activity only when degraded by protease at the C-terminal into smaller molecules of 29.8 kDa. Although PS5 showed no significant homology with other known parasporins, a Position Specific Iterative-Basic Local Alignment Search Tool (PSI-BLAST) search revealed that the protein showed slight homology to, not only some B. thuringiensis Cry toxins, but also to aerolysin-type β-pore-forming toxins (β-PFTs). The recombinant PS5 protein could be obtained as an active protein only when it was expressed in a precursor followed by processing with proteinase K. The cytotoxic activities of the protein against various mammalian cell lines were evaluated. PS5 showed strong cytocidal activity to seven of 18 mammalian cell lines tested, and low to no cytotoxicity to the others. 相似文献
125.
126.
127.
128.
Immunohistochemical staining of Ha-ras oncogene product in normal, benign, and malignant human pancreatic tissues 总被引:106,自引:0,他引:106
We examined immunohistochemical staining with Ha-ras oncogene product in normal, benign, and malignant human pancreatic tissues. In cases of pancreatic cancer, its relation to histologic type was evaluated. Serous cystadenoma and atypical acinar cell nodules did not react with the Ha-ras oncogene product, and ductal cells and acinar cells in normal pancreas showed lower immunoreactivity than other benign or malignant lesions. However, the positive rate of islet cells in normal pancreas was almost the same in cases of pancreatic cancer. Strongest positivity was observed in cases of chronic pancreatitis, and islet cell tumors also showed high positive staining rates. In pancreatic cancer, the positive rate of well-differentiated adenocarcinomas was rather higher than that of poorly differentiated adenocarcinomas. Our study indicates that the Ha-ras oncogene p21 product does not correlate with neoplastic transformation in human pancreas, is not a useful marker for differentiating benign and malignant lesions, and cannot be used to determine the origin of differentiation in the pancreas. 相似文献
129.
Lipopolysaccharide interaction with cell surface Toll-like receptor 4-MD-2: higher affinity than that with MD-2 or CD14 总被引:20,自引:0,他引:20
Akashi S Saitoh S Wakabayashi Y Kikuchi T Takamura N Nagai Y Kusumoto Y Fukase K Kusumoto S Adachi Y Kosugi A Miyake K 《The Journal of experimental medicine》2003,198(7):1035-1042
Toll-like receptors (TLRs) are innate recognition molecules for microbial products, but their direct interactions with corresponding ligands remain unclarified. LPS, a membrane constituent of gram-negative bacteria, is the best-studied TLR ligand and is recognized by TLR4 and MD-2, a molecule associated with the extracellular domain of TLR4. Although TLR4-MD-2 recognizes LPS, little is known about the physical interaction between LPS and TLR4-MD-2. Here, we demonstrate cell surface LPS-TLR4-MD-2 complexes. CD14 greatly enhances the formation of LPS-TLR4-MD-2 complexes, but is not coprecipitated with LPS-TLR4-MD-2 complexes, suggesting a role for CD14 in LPS loading onto TLR4-MD-2 but not in the interaction itself between LPS and TLR4-MD-2. A tentative dissociation constant (Kd) for LPS-TLR4-MD-2 complexes was approximately 3 nM, which is approximately 10-20 times lower than the reported Kd for LPS-MD-2 or LPS-CD14. The presence of detergent disrupts LPS interaction with CD14 but not with TLR4-MD-2. E5531, a lipid A antagonist developed for therapeutic intervention of endotoxin shock, blocks LPS interaction with TLR4-MD-2 at a concentration 100 times lower than that required for blocking LPS interaction with CD14. These results reveal direct LPS interaction with cell surface TLR4-MD-2 that is distinct from that with MD-2 or CD14. 相似文献
130.
Antineutrophil cytoplasmic antibodies in Japanese patients with inflammatory bowel disease: prevalence and recognition of putative antigens 总被引:1,自引:0,他引:1
Sugi K Saitoh O Matsuse R Tabata K Uchida K Kojima K Nakagawa K Tanaka S Teranishi T Hirata I Katsu K 《The American journal of gastroenterology》1999,94(5):1304-1312
OBJECTIVE: Our aim was to investigate the prevalence of antineutrophil cytoplasmic antibodies (ANCA) in Japanese patients with ulcerative colitis (UC) and Crohn's disease (CD), and the putative antigens recognized by perinuclear staining pattern ANCA (p-ANCA)-positive sera. METHODS: Sera from UC (n = 52) and CD (n = 43) patients, and from healthy controls (n = 74) were studied. The indirect immunofluorescence (IIF) method was used for the detection of ANCA and its binding pattern. p-ANCA-positive sera were studied further for putative antigens. ELISAs using lactoferrin (Lf), myeloperoxidase (MPO), and cathepsin G (Cat G) as antigens were performed. RESULTS: ANCA was positive in 40 of the 52 (76.9%) UC (p-ANCA in 33) and in 32 of the 43 (74.4%) CD (p-ANCA in 31) patients. UC and CD patients showed significantly higher titers of p-ANCA than controls; however, no significant difference was observed between UC and CD. In UC, 23, 17, and nine of the 33 patients with p-ANCA-positive sera showed reactivity with Lf, MPO, and Cat-G, respectively. In CD, 21, 20, and 11 of the 31 patients with p-ANCA-positive sera showed reactivity with Lf, MPO, and Cat-G, respectively. Fourteen of the UC and six of the CD patients showed reactivity with two different antigens, and seven of the UC and 11 of the CD patients showed reactivity with all three antigens. The presence of anti-Lf and anti-MPO antibodies was further confirmed by Western blotting. CONCLUSIONS: ANCA is useful in distinguishing patients with IBD from normal subjects but is not sufficient for the differential diagnosis of CD and UC. p-ANCA reactivity might be derived from the recognition of heterogeneous neutrophil-associated antigens. 相似文献