全文获取类型
收费全文 | 22276篇 |
免费 | 1092篇 |
国内免费 | 132篇 |
专业分类
耳鼻咽喉 | 199篇 |
儿科学 | 273篇 |
妇产科学 | 200篇 |
基础医学 | 2629篇 |
口腔科学 | 426篇 |
临床医学 | 1357篇 |
内科学 | 5351篇 |
皮肤病学 | 1486篇 |
神经病学 | 1980篇 |
特种医学 | 946篇 |
外科学 | 4048篇 |
综合类 | 118篇 |
预防医学 | 573篇 |
眼科学 | 180篇 |
药学 | 1711篇 |
中国医学 | 45篇 |
肿瘤学 | 1978篇 |
出版年
2023年 | 97篇 |
2022年 | 166篇 |
2021年 | 398篇 |
2020年 | 237篇 |
2019年 | 301篇 |
2018年 | 429篇 |
2017年 | 332篇 |
2016年 | 418篇 |
2015年 | 455篇 |
2014年 | 588篇 |
2013年 | 685篇 |
2012年 | 1062篇 |
2011年 | 1140篇 |
2010年 | 629篇 |
2009年 | 530篇 |
2008年 | 1036篇 |
2007年 | 1147篇 |
2006年 | 1108篇 |
2005年 | 1109篇 |
2004年 | 1136篇 |
2003年 | 1114篇 |
2002年 | 1085篇 |
2001年 | 650篇 |
2000年 | 702篇 |
1999年 | 678篇 |
1998年 | 330篇 |
1997年 | 228篇 |
1996年 | 225篇 |
1995年 | 212篇 |
1994年 | 167篇 |
1993年 | 135篇 |
1992年 | 464篇 |
1991年 | 420篇 |
1990年 | 424篇 |
1989年 | 461篇 |
1988年 | 427篇 |
1987年 | 392篇 |
1986年 | 340篇 |
1985年 | 299篇 |
1984年 | 178篇 |
1983年 | 162篇 |
1982年 | 91篇 |
1979年 | 170篇 |
1978年 | 88篇 |
1977年 | 86篇 |
1975年 | 74篇 |
1974年 | 73篇 |
1973年 | 82篇 |
1972年 | 85篇 |
1970年 | 74篇 |
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
41.
A Numata T Masuda T Okayasu M Hashimoto T Tanabe 《[Zasshi] [Journal]. Nihon Kyōbu Geka Gakkai》1989,37(2):350-354
A case of benign fibrous histiocytoma of the lung in a 8 years old boy was presented. He was first admitted in May, 1983, with recurrent pneumonia. Chest X-ray showed a ill-defined mass in the right lower lobe. Bronchoscopy revealed a round tumor, 1 cm. in maximum diameter, with complete obstruction of the Truncus Intermedius. Endoscopic resection was performed and partial obstruction of the Truncus Intermedius remained. He was re-admitted with pneumonia of the right middle lobe in March, 1986. Bronchoscopy showed severe stenosis of the Truncus Intermedius. Right middle and lower lobectomy was performed. The 4 X 4 X 3 cm tumor was located in the median of the Truncus Intermedius. Microscopically, the lesion composed of fibroblast-like cells and histiocyte-like cells. The patient's post-operative course was uneventful. He has no signs of local recurrence or metastasis. We believe, this is the first reported primary benign fibrous histiocytoma of the lung in a child in Japan. 相似文献
42.
E Nakashima K Yokogawa F Ichimura T Hashimoto T Yamana A Tsuji 《Journal of pharmaceutical sciences》1987,76(1):10-13
The effects of fasting on the pharmacokinetics of biperiden in rats were examined. Total clearance of biperiden was greater than 90% ascribable to hepatic clearance and was essentially blood-flow dependent. The number of compartments in the preferred pharmacokinetic model of biperiden changed from three (for normal rats) to two (for fasted rats). The smaller mean residence time (MRT) values found for fasted rats were attributable to decreases in distribution volume. Biperiden showed much higher lipophilicity than haloperidol, thiopental, and hexobarbital, and its tissue-to-plasma partition coefficient in adipose tissue was 20-fold higher than that in muscle. The influence of changes in volumes of adipose tissue and muscle on distribution volume (Vdss/BW) was evaluated from tissue-to-plasma partition coefficients. The value of Vdss/BW was predicted to decrease with decrease of adipose tissue, and to increase with decrease of muscle tissue. These results suggest that the observed decrease of Vdss/BW in fasted rats reflects reduced capacity to trap biperiden in the body, especially in adipose tissue. Possible clinical implications of these results are discussed. 相似文献
43.
Shinichi Toyooka Hideaki Mori Katsuyuki Kiura Hiroshi Date 《European journal of cardio-thoracic surgery》2008,33(2):315-316
We present a case of a 58-year-old man with diagnosis of lung adenocarcinoma invading the left atrium. He was treated with induction chemoradiotherapy for T4N1M0 disease, showing objective response. Then, a left upper lobectomy with a partial resection of the left atrium was performed without cardiopulmonary bypass. No residual tumor cells existed in the resected specimens, showing pathological complete response. Our case suggests that induction chemoradiotherapy prior to surgery can be an appropriate strategy among carefully selected patients with non-small cell lung cancer invading the left atrium. 相似文献
44.
Mikio Mikami Chisei Tei Kyoko Takehara Shinichi Komiyama Atsushi Suzuki Takanori Hirose 《International journal of gynecological pathology》2003,22(2):205-208
A 38-year-old female presented with a lower abdominal mass. During the operation the mass was found to be retroperitoneal and was excised. Gross examination revealed a mucin-containing cystic lesion with a mural nodule. On microscopic examination, the cystic areas were lined by an invasive mucinous adenocarcinoma and the nodule was composed of an anaplastic sarcomatoid tumor that was immunoreactive for cytokeratin. This present case is the 21st example of a retroperitoneal primary mucinous cystadenocarcinoma and the fourth with a mural nodule. Three of four cases with a mural nodule, including our case, had a rapidly fatal outcome. 相似文献
45.
46.
47.
Kiichiro Hashimoto Naohide Mori Takao Tamesa Toshimasa Okada Shigeto Kawauchi Atsunori Oga Tomoko Furuya Akira Tangoku Masaaki Oka Kohsuke Sasaki 《Modern pathology》2004,17(6):617-622
To clarify the genetic aberrations involved in the development and progression of hepatitis C virus-associated hepatocellular carcinoma (HCV-HCC), we investigated DNA copy number aberrations (DCNAs) in 19 surgically resected HCCs by conventional CGH and array CGH. Conventional CGH revealed that increases of DNA copy number were frequent at 1q (79% of the cases), 8q (37%), 6p (32%), and 10p (32%) and that decreases were frequent at 17p (79%), 16q (58%), 4q (53%), 13q (42%), 10q (37%), 1p (32%), and 8p (32%). In general, genes that showed DCNAs by array CGH were usually located in chromosomal regions with DCNAs detected by conventional CGH analysis. Increases in copy numbers of the LAMC2, TGFB2, and AKT3 genes (located on 1q) and decreases in copy numbers of FGR/SRC2 and CYLD (located on 1p and 16q, respectively) were observed in more than 30% of tumors, including small, well-differentiated carcinomas. These findings suggest that these genes are associated with the development of HCV-HCC. Increases of MOS, MYC, EXT1, and PTK2 (located on 8q) were detected exclusively in moderately and poorly differentiated tumors, suggesting that these alterations contribute to tumor progression. In conclusion, chromosomal and array CGH technologies allow identification of genes involved in the development and progression of HCV-HCC. 相似文献
48.
Cytoplasmic architecture of the axon terminal: filamentous strands specifically associated with synaptic vesicles 总被引:4,自引:0,他引:4
Cytoplasmic architecture of axon terminals in rat central nervous tissue was examined by quick-freeze deep-etch method to determine how synaptic vesicles and their associated cytoplasmic environment are organized in the terminal and to know how these structures participate in the mechanism for neurotransmitter release. The axoplasm is divisible into two domains: one occupied by mitochondria in the middle of the terminal, called the mitochondrial domain, the other situated in the periphery and exclusively filled with spherical synaptic vesicles, 50-60 nm in diameter, the synaptic vesicle domain. The most characteristic feature of the mitochondrial domain was the appearance of many microtubules connected with mitochondria by filamentous strands. Large vesicles, 80-100 nm in diameter, were preferentially associated with the mitochondrial domain, and linked with microtubules wherever they appeared. The cytoplasmic matrix of the synaptic vesicle domain showed a more fibrillar texture than that of the mitochondrial domain because of the distribution of filamentous strands associated with synaptic vesicles. These strands were significantly thicker and longer (mean 11.7 nm thick and 42.7 nm long) than those linking membrane-bound organelles to microtubules (mean 8.3 nm thick and 23.0 nm long), and connected vesicles to one another or to the plasma membrane, making a complicated network around the vesicles. Further, both strands were significantly different in dimension from actin filaments (mean 9.9 nm thick and 73.5 nm long) showing 5-nm axial periodicity. These strands, especially synaptic vesicle-associated ones including their network, were readily broken down in the most part by detergent treatment or chemical fixation, indicating that they are very delicate in nature. Granular materials, which are spherical and vary in size (6-20 nm in diameter), are also more conspicuous in the synaptic vesicle domain than in the mitochondrial domain. More fibrillar and granular cytoplasmic structure of the synaptic vesicle domain may be crucial for synaptic vesicles to perform an essential role in releasing the transmitter. 相似文献
49.
Yoshiharu Kikawa Akio Nakai Yosuke Shigematsu Masakatsu Sudo Kimitaka Kato Shinichi Haruki 《Pediatric nephrology (Berlin, Germany)》1990,4(4):343-344
Leukotriene B4 (LTB4) production in polymorphonuclear leucocytes (PMN) was examined in ten children with steroid-responsive nephrotic syndrome (SRNS) before, during, and after steroid administration. Comparison of LTB4 production was made in 14 children with non-inflammatory disease who were not receiving steroid therapy. No significant change was noted in PMN LTB4 biosynthesis in children with SRNS throughout any phase of the disease. Furthermore, there was no significant difference in LTB4 biosynthesis in PMN between SRNS patients before steroid therapy and patients with non-inflammatory disease. These findings suggest that inhibition of LTB4 production is not involved in the mechanism underlying steroid action in SRNS. 相似文献
50.
The structure-acute toxicity relationship of aromatic hydrocarbons was examined in mice. In all test compounds, the acute toxicity was determined under 2 conditions: control LD50 (LD50-cont) and carbon tetrachloride (CCl4)-pretreated LD50 (LD50-CCl4). The CCl4-pretreatment was done in order to evaluate the toxic potency of compound itself without the influence of metabolism. Both log (1/LD50-cont) and log (1/LD50-CCl4) were functions of the log P, n-octanol/water partition coefficient, i.e., log (1/LD50-cont) = 0.080 log P − 1.532 and log (1/LD50-CCl4) = −0.040(log P)2 + 0.157 log P − 1.373. Both equations were statistically significant (P < 0.01). The ratio of LD50-cont/LD50-CCl4 indicated that metabolic activation is more evident in hydrophobic compounds than in hydrophilic compounds. The results suggest that hydrophobicity of the aromatic hydrocarbons plays an important role in determining their acute toxicity. 相似文献