全文获取类型
收费全文 | 3407篇 |
免费 | 178篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 27篇 |
妇产科学 | 28篇 |
基础医学 | 398篇 |
口腔科学 | 101篇 |
临床医学 | 202篇 |
内科学 | 1143篇 |
皮肤病学 | 66篇 |
神经病学 | 221篇 |
特种医学 | 184篇 |
外科学 | 543篇 |
综合类 | 4篇 |
预防医学 | 54篇 |
眼科学 | 61篇 |
药学 | 161篇 |
中国医学 | 7篇 |
肿瘤学 | 384篇 |
出版年
2023年 | 22篇 |
2022年 | 30篇 |
2021年 | 60篇 |
2020年 | 49篇 |
2019年 | 70篇 |
2018年 | 66篇 |
2017年 | 61篇 |
2016年 | 76篇 |
2015年 | 78篇 |
2014年 | 104篇 |
2013年 | 116篇 |
2012年 | 186篇 |
2011年 | 176篇 |
2010年 | 138篇 |
2009年 | 116篇 |
2008年 | 183篇 |
2007年 | 189篇 |
2006年 | 197篇 |
2005年 | 219篇 |
2004年 | 206篇 |
2003年 | 187篇 |
2002年 | 191篇 |
2001年 | 68篇 |
2000年 | 62篇 |
1999年 | 60篇 |
1998年 | 46篇 |
1997年 | 53篇 |
1996年 | 46篇 |
1995年 | 33篇 |
1994年 | 29篇 |
1993年 | 29篇 |
1992年 | 58篇 |
1991年 | 39篇 |
1990年 | 49篇 |
1989年 | 40篇 |
1988年 | 47篇 |
1987年 | 20篇 |
1986年 | 33篇 |
1985年 | 24篇 |
1984年 | 18篇 |
1983年 | 18篇 |
1982年 | 8篇 |
1981年 | 9篇 |
1979年 | 13篇 |
1978年 | 10篇 |
1977年 | 8篇 |
1976年 | 8篇 |
1973年 | 9篇 |
1971年 | 12篇 |
1966年 | 7篇 |
排序方式: 共有3625条查询结果,搜索用时 15 毫秒
41.
Toshifumi Ozaki Silke Flege Matthias Kevric Norbert Lindner Rainer Maas Günter Delling Rudolf Schwarz Arthur R von Hochstetter Mechthild Salzer-Kuntschik Wolfgang E Berdel Heribert Jürgens G Ulrich Exner Peter Reichardt Regine Mayer-Steinacker Volker Ewerbeck Rainer Kotz Winfried Winkelmann Stefan S Bielack 《Journal of clinical oncology》2003,21(2):334-341
PURPOSE: To define patients and tumor characteristics as well as therapy results, patients with pelvic osteosarcoma who were registered in the Cooperative Osteosarcoma Study Group (COSS) were analyzed. PATIENTS AND METHODS: Sixty-seven patients with a high-grade pelvic osteosarcoma were eligible for this analysis. Fifteen patients had primary metastases. All patients received chemotherapy according to COSS protocols. Thirty-eight patients underwent limb-sparing surgery, 12 patients underwent hemipelvectomy, and 17 patients did not undergo definitive surgery. Eleven patients received irradiation to the primary tumor site: four postoperatively and seven as the only form of local therapy. RESULTS: Local failure occurred in 47 of all 67 patients (70%) and in 31 of 50 patients (62%) who underwent definitive surgery. Five-year overall survival (OS) and progression-free survival rates were 27% and 19%, respectively. Large tumor size (P =.0137), primary metastases (P =.0001), and no or intralesional surgery (P <.0001) were poor prognostic factors. In 30 patients with no or intralesional surgery, 11 patients with radiotherapy had better OS than 19 patients without radiotherapy (P =.0033). Among the variables, primary metastasis, large tumor, no or intralesional surgery, no radiotherapy, existence of primary metastasis (relative risk [RR] = 3.456; P =.0009), surgical margin (intralesional or no surgical excision; RR = 5.619; P <.0001), and no radiotherapy (RR = 4.196; P =.0059) were independent poor prognostic factors. CONCLUSION: An operative approach with wide or marginal margins improves local control and OS. If the surgical margin is intralesional or excision is impossible, additional radiotherapy has a positive influence on prognosis. 相似文献
42.
Noriko Hosoya Kiyoshi Miyagawa Kinuko Mitani Yoshio Yazaki Hisamaru Hirai 《Cancer science》1998,89(8):821-824
The WT1 tumor suppressor gene was examined for mutations in a panel of 44 patients with myelo-dysplastic syndromes (MDS) including acute myelogenous leukemias (AML) secondary to MDS, using polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) analysis and sequencing analysis. A WT1 mutation was detected in one out of 17 cases of AML secondary to MDS. This mutation exists upstream of the zinc finger region and is predicted to produce a truncated WT1 protein lacking the zinc finger region. No mutations were detected in 27 MDS patients who had not progressed to AML. This is the first report of analysis for WT1 mutations in a large number of MDS patients, suggesting that WT1 mutations are uncommon in MDS. Abnormalities in this gene may, however, contribute to a small proportion of cases showing progression from MDS into AML. 相似文献
43.
Osamu Miyamoto Takehiro Nakamura Shin-ich Yamagami Tetsuro Negi Masaaki Tokuda Hideki Matsui Toshifumi Itano 《Brain research》2000,873(1):418
To investigate the mechanism of chronic cell death following postischemic hypothermia, the change of N-methyl-
-aspartate receptor (NMDAR) were examined by immunohistochemistry of NMDAR1 and long-term potentiation (LTP) in the CA1 subfield of the gerbil hippocampus. At 1 week following postischemic hypothermia (32°C×4 h), all CA1 neurons survived; however, immunoreactivity of NMDAR1 increased in neuronal perikarya whereas decreased in dendrites in the CA1 neurons. The abnormality was still observed in remaining CA1 neurons at 1 month after hypothermia. LTP was also significantly depressed at 1 week after hypothermia. These results suggest that some abnormalities in the glutamate receptor may be caused by ischemia; such abnormality would persist in spite of hypothermia treatment, resulting in the depression of LTP. 相似文献
44.
Yoshioka S Mitani H Maeda K Takeo S Matsuda K Katayama S Mizukawa R Kawahara R 《Brain research. Developmental brain research》2000,119(2):283-288
The effects of clonidine on the development of amygdaloid kindling were studied in rats of various ages (14, 21, 28 and 70 postnatal days). Administration of clonidine (0.2, 0.5 mg/kg i.p.) caused a significant retardation of kindling development in the 28-day-old rats as well as in the adult rats, whereas, in the 14-day-old rats, the development of kindling was significantly facilitated by clonidine. No significant effect of clonidine was observed in the 21-day-old rats. These results indicate that in rats the effects of clonidine on the development of amygdaloid kindling vary during development. 相似文献
45.
Izumi Nishimura Atsushi Oshima Kazumoto Shibuya Takashi Mitani Tadashi Negishi 《Regulatory toxicology and pharmacology : RTP》2012
The use of intermediate frequency (IF) magnetic fields (MFs) in occupational equipment and domestic appliances, such as inductive heating cookers, is increasing. The WHO indicated a lack of scientific evidence needed to assess the health risk of exposure to IF MFs. Male and female rats (24/group) were exposed to a 20 kHz, 0.2 mT(rms) or 60 kHz, 0.1 mT(rms) sinusoidal MF for 22 h/day from 14 days prior to and during mating. Copulated females were exposed until gestation day 7 and sacrificed thereafter. Mated males were sacrificed to examine MF exposure effects on spermatogenesis. Reproductive examinations were blinded, and experiments were duplicated per frequency to ensure reproducibility. No statistically significant, exposure-related changes were found in the estrous cycle, copulation and fertility indices, numbers of corpora lutea and implantation sites, or pre- and postimplantation loss. No reproducible changes were observed in sperm count, motility, or morphological abnormality, or in the weights of testes and epididymides after MF exposure. No significant abnormalities were observed in gross pathology or histopathology of the uterus, ovary, testis, and epididymis in the MF- or sham-exposed groups. MF exposure during the preimplantation period was not toxic to fertility or early embryogenesis under the experimental conditions. 相似文献
46.
N. Motoi Tsuyoshi Ishida Imaharu Nakano Nobu Akiyama Kinuko Mitani Hisamaru Hirai Yoshio Yazaki Rikuo Machinami 《Acta neuropathologica》1997,93(3):301-305
A 64-year-old man in a severely immunocompromised state due to acute myelogenous leukemia died, respirator-unaided, about
10 h after the abrupt onset of coma. An earlier blood culture had yielded Bacillus cereus. The autopsy, performed 2 h after death, demonstrated diffuse subarachnoid hemorrhage without berry aneurysms, and the formalin-fixed
brain was tinged with gray-brownish discoloration. The sections of the brain presented a whitish tint of the surface layer
of all portion of the cerebral cortices, even those in the sulci. Histological examination of the brain revealed leptomeningeal
B. cereus dissemination, and widespread necrosis of the leptomeninges and arachnoid vessels without inflammatory cell reaction. The
grossly recognizable whitish surface layer of the cerebral cortex showed overt hyperchromatism, and contained neurons more
degenerative than those located in the deeper cortical layer. The total absence of inflammatory reaction may be explained
by a combination of the immunocompromised state of the patient and the character of B. cereus infection, which in itself induces little inflammatory reaction. The prominent lesions were confined to the cerebral surface
layer and leptomeningeal tissue including the arachnoid vessels, which were all bathed in the cerebrospinal fluid, suggesting
that some necrotizing toxins had been secreted into the fluid by the B. cereus. The necrosis of arachnoid vessels is thought to have in turn caused diffuse subarachnoid hemorrhage and marked disturbance
of the cerebral blood flow, resulting in the terminal coma.
Received: 4 April 1996 / Revised, accepted: 8 September 1996 相似文献
47.
48.
Rie Fukui Eriko Tanabe Misaho Kitayoshi Kyohei Yoshikawa Nobuyuki Fukushima Toshifumi Tsujiuchi 《Tumour biology》2012,33(6):1899-1905
Lysophosphatidic acid (LPA) mediates a wide range of biological responses with G protein-coupled transmembrane receptors (LPA receptors). So far, at least six types of LPA receptors (LPA receptor-1 (LPA1) to LPA6) have been identified. Recently, it has been reported that LPA3 indicates opposite effects on cellular functions of cancer cells. In the present study, to assess a biological role of LPA3 on cell migration ability of colon cancer cells, we generated LPA receptor-3 (LPAR3) knockdown (HCT-sh3-3) cells from HCT116 and measured cell motile and invasion activities. In motility assay with a cell culture insert, HCT-sh3-3 cells showed significantly high cell motile activity, compared with control cells. For invasion assay, the filter was coated with Matrigel. The invasive activity of HCT-sh3-3 cells was significantly higher than that of control cells. Furthermore, we also examined the effects of LPAR3 knockdown on the interaction between colon cancer cells and endothelial F-2 cells. When F-2 cells were cultured with serum-free DMEM containing a supernatant from HCT-sh3-3 cells, the cell growth rate and migration activity of F-2 cells were significantly stimulated, associating with the elevated expressions of vascular endothelial growth factor (VEGF)-A and VEGF-C genes in HCT-sh3-3 cells. These results suggest that LPA3 may act as a negative regulator on cell motile and invasive abilities of colon cancer HCT116 cells. 相似文献
49.
50.
Kuriyama M Kato J Kuwaki K Morimoto N Nawa T Fujimoto T Kono H Okano N Miyaike J Morita T Okada H Suzuki S Yoshioka T Shiode J Suwaki K Sakaguchi K Shiratori Y;Japan West Ulcerative Colitis Study Group 《European journal of gastroenterology & hepatology》2008,20(7):634-641
BACKGROUND AND AIM: The health-related quality of life (HRQOL) of patients with ulcerative colitis (UC) can be impaired because of the chronic symptoms. Although UC patients suffer from such symptoms over the long term, there have been few reports on the changes of HRQOL with disease duration. The aim of this study was to clarify these changes. METHODS: The HRQOL of 331 Japanese UC patients was examined using the validated Japanese version of the Inflammatory Bowel Disease Questionnaire (J-IBDQ). HRQOL and factors affecting HRQOL identified using multiple linear regression analysis were stratified by disease duration. RESULTS: Of the 15 clinical factors examined, the clinical activity index score was the strongest determinant (P<0.0001) of all the scores of IBDQ regardless of disease duration. HRQOL did not differ significantly among patients with different disease durations. The factors, however, that affected HRQOL varied according to disease duration. In patients with disease duration of less than 5 years, the clinical activity index score was the predominant factor affecting HRQOL. Being 'on sick leave or hospitalized' was a significant factor impairing HRQOL in patients with disease duration of 5-9 years. Moreover, complications due to corticosteroids significantly impaired all of the IBDQ scores in patients with disease duration of 10 years or more. CONCLUSION: Factors that affected the HRQOL of UC patients varied according to the patients' disease duration. Our findings should assist in the development of a long-term strategy for the treatment of UC patients. 相似文献