全文获取类型
收费全文 | 4475篇 |
免费 | 245篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 68篇 |
儿科学 | 84篇 |
妇产科学 | 53篇 |
基础医学 | 617篇 |
口腔科学 | 91篇 |
临床医学 | 268篇 |
内科学 | 1034篇 |
皮肤病学 | 170篇 |
神经病学 | 266篇 |
特种医学 | 126篇 |
外科学 | 937篇 |
综合类 | 10篇 |
预防医学 | 81篇 |
眼科学 | 34篇 |
药学 | 329篇 |
中国医学 | 5篇 |
肿瘤学 | 578篇 |
出版年
2023年 | 30篇 |
2022年 | 38篇 |
2021年 | 91篇 |
2020年 | 38篇 |
2019年 | 74篇 |
2018年 | 96篇 |
2017年 | 78篇 |
2016年 | 79篇 |
2015年 | 105篇 |
2014年 | 103篇 |
2013年 | 160篇 |
2012年 | 262篇 |
2011年 | 253篇 |
2010年 | 177篇 |
2009年 | 143篇 |
2008年 | 284篇 |
2007年 | 284篇 |
2006年 | 309篇 |
2005年 | 361篇 |
2004年 | 340篇 |
2003年 | 285篇 |
2002年 | 349篇 |
2001年 | 56篇 |
2000年 | 53篇 |
1999年 | 82篇 |
1998年 | 104篇 |
1997年 | 76篇 |
1996年 | 70篇 |
1995年 | 52篇 |
1994年 | 39篇 |
1993年 | 42篇 |
1992年 | 23篇 |
1991年 | 25篇 |
1990年 | 13篇 |
1989年 | 14篇 |
1988年 | 16篇 |
1987年 | 12篇 |
1986年 | 11篇 |
1985年 | 14篇 |
1984年 | 10篇 |
1983年 | 17篇 |
1982年 | 10篇 |
1981年 | 17篇 |
1980年 | 8篇 |
1979年 | 7篇 |
1978年 | 7篇 |
1976年 | 4篇 |
1974年 | 4篇 |
1971年 | 4篇 |
1964年 | 4篇 |
排序方式: 共有4751条查询结果,搜索用时 125 毫秒
61.
Keiji Uchikawa 《Vision research》1983,23(1):53-58
Purity discrimination thresholds (Δp) were measured with successive (SOA = 3 sec) and simultaneous (SOA = 0 sec) comparison methods for seven dominant wavelengths: 410, 480, 500, 530, 570, 600 and 650 nm. The stimulus duration was 1 sec. The Δp values with the successive comparison method were found to he about 1.5–2.0 times larger than those obtained in the simultaneous case. The degree of purity discrimination deterioration shown in this study is similar to that of wavelength discrimination deterioration previously reported (Uchikawa and Ikeda, 1981, Vision Res.21, 591–595). Saturation shifts of stimuli with the successive comparison method were also observed: these were toward increased saturation direction for most dominant wavelengths. 相似文献
62.
Kohei Notoya Ryoichi Tsukuda Keiji Yoshida Shigehisa Taketomi 《Calcified tissue international》1992,51(Z1):S16-S20
The effects of ipriflavone (IP) (10–5 M) on bone formation were studied in stromal cells from the femoral bone marrow of young adult rats cultured for 21 days in the presence of -glycerophosphate and dexamethasone. Stereoscopic microscopy showed nodule formation after 14 days of culturing, and both the number and the size of the nodules increased with time. The alizarin-red-stained calcified area in the nodules in the IP group was nearly 4 times as large as that in the control after 21 days. Light and electron microscopy revealed the presence of many osteoblast-like cells with developed rough endoplasmic reticulum and Golgi apparatus in the nodules in the control group after 14 days, and a collagenous fibril network was seen among the cells. After 21 days, calcification of the dense collagenous fibril network and bone matrix-like tissue were observed in many nodules, resulting in the formation of bone-like tissue containing osteocyte-like cells. In the IP group, the collagenous fibril network area in the nodules was greater than that in the control after 14 days, and a further increase in both the dense collagenous fibril network area and calcified bone-like tissue area was observed after 21 days. These findings indicate that IP stimulates bone-like tissue formation in the rat bone marrow stromal cell culture, suggesting that the promotion of collagen production by osteoblasts is involved in the stimulation of bone-like tissue formation by IP. 相似文献
63.
Comparative study of bioartificial liver support and plasma exchange for treatment of pigs with fulminant hepatic failure 总被引:6,自引:0,他引:6
Recently, bioartificial liver (BAL) treatment was reported to provide beneficial effects for patients with fulminant hepatic failure (FHF). Some success in experimental or clinical trials has been reported; however, the evaluation of BAL efficacy remains unclear, especially in comparison with other treatments for FHF. The purpose of this study was to compare the efficacy between BAL and plasma exchange (PE) in experimentally induced FHF in pigs. Pigs undergoing hepatic devascularization (HD) were placed into the following groups: no treatment (control; n = 6), BAL treatment (BAL; n = 5), and plasma exchange (PE; n = 5). Each treatment was initiated 6 h after HD and lasted for 4 h. BAL treatment significantly improved liver functions in FHF pigs. The decrease in cerebral perfusion pressure was also significantly suppressed in the pigs with BAL, and their survival time was prolonged compared with the results in pigs with PE. The effects of BAL outperform those of PE in the treatment of experimental FHF model. 相似文献
64.
Akifumi Kuwabara Hidenobu Watanabe Yoichi Ajioka Kazuhiro Yasuda Hidetoshi Saito Keiji Matsuda Hiroshi Kijima Katuyoshi Hatakeyama 《Cancer science》1998,89(1):40-46
The aim of this study was to clarify whether or not the status of gene alteration is heterogeneous in intramucosal carcinoma and homogeneous within invasive carcinoma. We selected 10 colorectal carcinoma cases (1 mucosal, 5 submucosal and 4 advanced carcinomas including 2 cases with lymph node metastasis) and analyzed the p53 gene sequence. Six colorectal cancers in this study showed heterogeneity in p53 mutations in cells from the intramucosal part. In the invasive part of a carcinoma, p53 mutation status was homogeneous intratumorally in all cases. These data indicate that, in regard to p53 gene alterations, colorectal cancers can be composed of various subclones when limited to the mucosa, but clonal selection occurs when one of these subclones commences invasion to the submucosa, generating a monoclonal invasive carcinoma. 相似文献
65.
Genetic Alterations of Mixed Hyperplastic Adenomatous Polyps in the Colon and Rectum 总被引:1,自引:2,他引:1
Hiroyuki Uchida Hiroshi Ando Keiji Maruyama Hiroshi Kobayashi Hiroshi Toda Hiroshi Ogawa Takachika Ozawa Yasuhide Matsuda Haruhiko Sugimura Takashi Kanno Shozo Baba 《Cancer science》1998,89(3):299-306
Some mixed hyperplastic adenomatous polyps (MHAPs) contain dysplastic lesions or even carcinomas. These polyps are considered to be different from ordinary hyperplastic polyps and may have a preneoplastic potential. We investigated APC and K- ras mutations in MHAPs of the colon and rectum, and also in colorectal adenomas and hyperplastic polyps to identify molecular differences between MHAPs, adenomas and hyperplastic polyps, using direct sequencing of mutation cluster regions (MCR) in APC and K- ras . No APC mutations were identified in 12 MHAPs and 8 hyperplastic polyps, whereas 10 of 27 (37.0%) adenomas showed somatic mutations. K- ras mutations were identified in one of 12 (8.3%) MHAPs, one of 8 (12.5%) hyperplastic polyps, and 10 of 27 (37.0%) adenomas. p53 mutation was found in a carcinoma arising in an MHAP. Mutations other than APC mutations may play a role in the development of MHAPs. 相似文献
66.
67.
Hironobu Shibata Masahiro Abe Kenji Hiura Javier Wilde Keiji Moriyama Toshiaki Sano Ken-Ichi Kitazoe Toshihiro Hashimoto Shuji Ozaki Shingo Wakatsuki Shinsuke Kido Daisuke Inoue Toshio Matsumoto 《Clinical cancer research》2005,11(17):6109-6115
PURPOSE: Receptor activator of nuclear factor-kappaB ligand (RANKL) is a key mediator of osteoclastogenesis. Because certain types of tumor cells aberrantly express RANKL, and because bone destruction also develops in B-cell lymphomas of bone origin, we investigated RANKL expression and the mechanisms of osteoclastogenesis in B-lymphoid neoplasms. EXPERIMENTAL DESIGN AND RESULTS: Immunohistochemistry of bone specimens resected from patients with primary B-cell lymphoma of bone with bone destruction revealed that lymphoma cells express RANKL as well as vascular endothelial cell growth factor (VEGF). The tumor cells isolated from the bone specimens enhanced osteoclastogenesis in vitro. In contrast, B-cell lymphoma infiltrating to the bone marrow without bone destruction did not express RANKL. Both RANKL and VEGF were expressed by a portion of B-lymphoid cell lines, including Daudi and IM-9. These RANKL-expressing tumor cells enhanced osteoclastogenesis from RAW264.7 cells and human monocyte-derived preosteoclasts in the absence of stromal cells/osteoblasts in a RANKL-dependent manner. Furthermore, conditioned media from Daudi cells enhanced transmigration of preosteoclasts that was inhibited by anti-VEGF antibody, suggesting that tumor cell-derived VEGF mediates recruitment of osteoclast precursors. Moreover, cocultures of B-lymphoid cell lines with osteoclasts enhanced the growth of B-lymphoid cells. CONCLUSIONS: Some malignant B cells aberrantly express functional RANKL as well as VEGF to enhance osteoclastogenesis. The coexpression of RANKL and VEGF may also contribute to the close cellular interactions with osteoclastic cells, thereby forming a vicious cycle between osteoclastic bone destruction and tumor expansion in bone. 相似文献
68.
Keiji Inoue Takashi Karashima Satoshi Fukata Asuka Nomura Chiaki Kawada Atsushi Kurabayashi Mutsuo Furihata Yuji Ohtsuki Taro Shuin 《Clinical cancer research》2005,11(18):6669-6677
PURPOSE: Transitional cell carcinoma (TCC) of the urinary tract is a chemosensitive tumor. Most deaths from TCC of the urinary tract are caused by metastasis, which is resistant to conventional chemotherapy. Frequent sites of metastases from TCC of the urinary tract are regional lymph nodes, liver, lung, and bone. Of these distant metastases, bone metastasis is consistently resistant to cisplatin-based conventional chemotherapy. Therefore, in this study, we investigated whether or not a newly developed minodronate, YM529, could prevent osteolytic bone metastasis of human TCC and also enhance the effect of docetaxel in a bone tumor model of athymic nude mice. EXPERIMENTAL DESIGN: In the present study, we evaluated the effect of in vitro treatment with minodronate and/or docetaxel on the proliferation by cell count, the induction of apoptosis by terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay, and the biological activity of osteoclast by pit formation assay in human bladder cancer cell line, UMUC-14, and mouse osteoclast cells. In vivo, we examined the effect of minodronate in a bone tumor model of athymic nude mice, in which the percutaneous intraosseal injection in the tibia of UMUC-14, leads to osteolytic bone tumor, as a bone metastasis model. To examine whether or not minodronate could inhibit tumorigenicity and enhance the effect of the chemotherapeutic agent, docetaxel, we gave minodronate i.p. and/or docetaxel i.p. to nude mice 3 days after an intraosseal tumor implantation. Moreover, proliferation and the induction of apoptosis of cancer cells and osteoclasts in bone tumors were determined by immunohistochemistry and the TUNEL assay. RESULTS: In vitro: In vitro treatment with docetaxel inhibited proliferation and resorption pit-forming activity and induced apoptosis of mouse osteoclast cells and UMUC-14 cells. In vitro treatment with minodronate inhibited proliferation and activity and induced apoptosis of mouse osteoclast cells but not UMUC-14 cells. The treatment with minodronate enhanced the inhibition of proliferation and activity by docetaxel in osteoclasts. In vivo: In vivo combination therapy with docetaxel and minodronate significantly reduced the tumor incidence compared with the control (P < 0.05) and also growth of intraossal TCC in athymic nude mice compared with the control (P < 0.001), single therapy with docetaxel (P < 0.01), and minodronate (P < 0.05). Drug-induced body weight loss was not significantly different in any treatment group. Therapy with minodronate significantly enhanced inhibition of proliferation by docetaxel in osteoclasts of bone tumors compared with the control (P < 0.01), single therapy with docetaxel (P < 0.01), and minodronate (P < 0.05). CONCLUSIONS: These studies indicate that combination therapy with minodronate and docetaxel may be beneficial in patients with bone metastasis of human TCC in the urinary tract. 相似文献
69.
Real‐world efficacy and safety of daclatasvir and asunaprevir therapy for hepatitis C virus‐infected cirrhosis patients
下载免费PDF全文
![点击此处可从《Journal of gastroenterology and hepatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Kei Morio Michio Imamura Yoshiiku Kawakami Reona Morio Tomoki Kobayashi Satoe Yokoyama Yuko Nagaoki Tomokazu Kawaoka Masataka Tsuge Akira Hiramatsu Grace Naswa Makokha C Nelson Hayes Hiroshi Aikata Daiki Miki Hidenori Ochi Yoji Honda Nami Mori Shintaro Takaki Keiji Tsuji Kazuaki Chayama 《Journal of gastroenterology and hepatology》2017,32(3):645-650
70.
Kyoko Kanno Masako Minami‐Hori Akemi Ishida‐Yamamoto Keiji Komura Kensuke Oikawa Naoyuki Miyokawa Hajime Iizuka 《The Journal of dermatology》2014,41(8):736-738
We report a 38‐year‐old male patient who presented with cutaneous lesions mimicking widespread discoid lupus erythematosus with high‐grade fever, arthralgia and lymphadenopathy. Additional lymph node and skin biopsies, however, revealed karyorrhectic debris without neutrophils and numerous CD68‐positive cells, a characteristic finding of Kikuchi's disease (KD). Comparing skin biopsies on different occasions, we could see different forms of histopathology. The histopathology of skin lesions of KD may vary during the clinical course, which may reflect the stage of the disease. 相似文献