全文获取类型
收费全文 | 3567篇 |
免费 | 137篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 63篇 |
妇产科学 | 122篇 |
基础医学 | 489篇 |
口腔科学 | 154篇 |
临床医学 | 212篇 |
内科学 | 889篇 |
皮肤病学 | 17篇 |
神经病学 | 153篇 |
特种医学 | 87篇 |
外科学 | 754篇 |
综合类 | 10篇 |
预防医学 | 48篇 |
眼科学 | 51篇 |
药学 | 195篇 |
中国医学 | 8篇 |
肿瘤学 | 461篇 |
出版年
2024年 | 4篇 |
2023年 | 23篇 |
2022年 | 50篇 |
2021年 | 84篇 |
2020年 | 28篇 |
2019年 | 58篇 |
2018年 | 79篇 |
2017年 | 65篇 |
2016年 | 79篇 |
2015年 | 83篇 |
2014年 | 120篇 |
2013年 | 145篇 |
2012年 | 224篇 |
2011年 | 247篇 |
2010年 | 162篇 |
2009年 | 118篇 |
2008年 | 235篇 |
2007年 | 229篇 |
2006年 | 224篇 |
2005年 | 231篇 |
2004年 | 252篇 |
2003年 | 248篇 |
2002年 | 212篇 |
2001年 | 39篇 |
2000年 | 35篇 |
1999年 | 48篇 |
1998年 | 41篇 |
1997年 | 28篇 |
1996年 | 43篇 |
1995年 | 34篇 |
1994年 | 35篇 |
1993年 | 19篇 |
1992年 | 16篇 |
1991年 | 17篇 |
1990年 | 19篇 |
1989年 | 23篇 |
1988年 | 21篇 |
1987年 | 12篇 |
1986年 | 11篇 |
1985年 | 8篇 |
1984年 | 9篇 |
1983年 | 10篇 |
1982年 | 11篇 |
1981年 | 6篇 |
1980年 | 10篇 |
1978年 | 3篇 |
1975年 | 3篇 |
1973年 | 4篇 |
1969年 | 6篇 |
1966年 | 3篇 |
排序方式: 共有3723条查询结果,搜索用时 15 毫秒
31.
OBJECTIVE: Transurethral enucleation of the prostate (TUE) is designed for complete removal of the prostate lobes. On the basis of TUE and holmium laser enucleation of the prostate, we developed a new technique of transurethral detachment prostatectomy (TUDP) using a tissue morcellator. MATERIALS AND METHODS: In TUDP, enucleation is performed with a prostate-detaching blade and the tip of a resectoscope, followed by removal of the tissue with a morcellator. This study reports our experience with TUDP in which the weight of retrieved tissue was greater than 30 g in 76 patients with benign prostate hyperplasia. RESULTS: The mean preoperative total prostate and adenoma volumes were 70.7 and 47.4 mL, respectively. The mean times required for enucleation, morcellation, and total operation time were 28.5, 14.4, and 66.3 minutes, respectively. The mean weight of removed prostate tissue was 61.1 g. The mean decreases in the levels hemoglobin and serum sodium were 1.73 mg/dL and 2.41 mEq/dL, respectively. The mean preoperative maximum flow rate (Qmax), International Prostate Symptom Score (IPSS), and quality of life score (QOL) improved from 9.8 mL/sec, 20.2, and 4.9, to 22.3 mL/sec, 3.1 and 1.2, respectively. Complications included mild morcellator-induced mucosal injury in 2 patients (2.6%), nausea in 4 patients (5.2%), transient urinary retention in 2 patients (2.6%), transient urge incontinence in 5 patients (6.4%), and urethral stricture in 2 patients (2.6%). The mean prostate volume and serum prostate-specific antigen level measured 6 months postoperatively in 46 patients were 10.68 mL and 0.89 ng/mL, respectively. CONCLUSIONS: TUDP is effective for complete removal of large prostate lobes in patients with large benign prostate hyperplasia and is associated with lower perioperative morbidity. 相似文献
32.
Shin-ichiro Shoda Akio Komenoi Tomochika Fujioka Yasunori Okumura Shiro Kobayashi 《Macromolecular chemistry and physics.》1996,197(2):633-640
Isopropoxyethyne (1a) and tert-butoxyethyne (1b) were polymerized using group 5 and 6 transition metal catalysts to give poly(isopropoxyethyne) (2a) and poly(tert-butoxyethyne) (2b) , respectively. The weight-average molecular weight (M?w) of the resulting poly(alkoxyethyne)s was up to 1.0 × 104. Among the transition metal catalysts, a tungsten alkoxide or a molybdenum alkoxide having low Lewis acidity were found to effectively promote the polymerization without causing side reactions. Poly(tert-butoxyethyne) was successfully converted to poly(β-ketone) 3 by acid hydrolysis of the tert-butyl vinyl moiety. 相似文献
33.
我们应用三维结构(3-D)再构成计算机系统,以0.2mm间隔连续切片,HE染色,对50例经纤维结肠镜切除的大肠腺瘤各种异型上皮的体积及分布规律进行研究。其中癌变17例(34%),其平均体积是单纯腺瘤的3.4倍。腺瘤体积越大,其癌变率越高,但体积较小的亚有蒂型腺瘤也有很高癌变率(25%)。研究结果表明腺瘤体积大小与平均异型度无相关关系。用常规方法切片,仅检出14例有癌变,漏诊率18%。为提高腺瘤癌变检出率,至少应以0.6mm间隔连续切片。此种方法对准确判定断端有无癌浸润也有重要意义。 相似文献
34.
Keiichi Tamai Masafumi Toyoshima Nobuyuki Tanaka Noriko Yamamoto Yuji Owada Hiroshi Kiyonari Kazuko Murata Yoshiyuki Ueno Masao Ono Tooru Shimosegawa Nobuo Yaegashi Masahiko Watanabe Kazuo Sugamura 《The American journal of pathology》2008,173(6):1806-1817
The endosomal sorting complex required for transport (ESCRT) proteins form multimolecular complexes that control multivesicular body formation, endosomal sorting, and transport ubiquitinated membrane proteins (including cell-surface receptors) to the endosomes for degradation. There is accumulating evidence that endosomal dysfunction is linked to neural cell degeneration in vitro, but little is known about the relationship between neural disorders and ESCRT proteins in vivo. Here we specifically deleted the hrs gene, ESCRT-0, in the neurons of mice by crossing loxP-flanked hrs mice with transgenic mice expressing the synapsin-I Cre protein (SynI-cre). Histological analyses revealed that both apoptosis and a loss of hippocampal CA3 pyramidal neurons occurred in the hrsflox/flox;SynI-cre mice. Notably, the hrsflox/flox;SynI-cre mice accumulated ubiquitinated proteins, such as glutamate receptors and an autophagy-regulating protein, p62. These molecules are particularly prominent in the hippocampal CA3 neurons and cerebral cortex with advancing age. Accordingly, we found that both locomotor activity and learning ability were severely reduced in the hrsflox/flox;SynI-cre mice. These data suggest that Hrs plays an important role in neural cell survival in vivo and provide an animal model for neurodegenerative diseases that are known to be commonly affected by the generation of proteinaceous aggregates. 相似文献
35.
36.
Ueno Shu-ichi; Kondoh Keiji; Komure Yasunori; Komure Osamu; Kuno Sadako; Kawai Jun; Hazama Fumitada; Sano Akira 《Human molecular genetics》1995,4(4):663-666
An unstable expansion of CAG repeat in the coding region ofthe DRPLA gene on chromosome 12p is the mutation specific forhereditary dentatorubralpallidoluysian atrophy (DRPLA). We studiedthe CAG expansion in brain and other tissues from six unre latedDRPLA patients. The CAG repeat lengths showed distinct difterencesbetween tissues. The sizes of the CAG expansion in various regionsof the brain except the cerebellum were generally larger byseveral repeats than in other peripheral tissues. Brain samplesshowed greater variation of the expansion compared with othertissues, but neither the size of the CAG expansion nor the degreeof CAG repeat variation parallels the detailed findings of neuropathologicalinvolvement. We conclude that somatic instabilities of the CAGrepeat cause tissue variability of the CAG repeat size in DRPLAbut other region or cell type-specific factors would be involvedto explain the selectivity of cell damage in DRPLA. 相似文献
37.
38.
Sato Y Harada K Sudo Y Watanabe K Nakahama T Morimoto H Nakanuma Y 《Pathology international》2002,52(7):478-482
Autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) are representative autoimmune liver diseases in which hepatocytes and intrahepatic bile ducts, respectively, are selectively damaged by autoimmune mechanisms. Bile duct injury and loss is characteristic of PBC and chronic non-suppurative destructive cholangitis (CNSDC), in particular, is a histological hallmark of PBC. In this report, we present an unusual case of AIH accompanied by CNSDC-like bile duct injury in a 46-year-old woman. The patient's serum aminotransferase level was abnormally high. The serum levels of alkaline phosphatase, gamma-GTP and IgG were also elevated, but the IgM level was within normal limits. The titer of antismooth muscle antibody (SMA) was 1:80, while antinuclear autoantibody (ANA) and the M2 fraction of antimitochondrial antibody (AMA) were both negative. Liver biopsy disclosed CNSDC-like bile duct injuries and severe interface hepatitis and lobular hepatitis with perivenular zonal necrosis were observed. The aggregate score of the International Autoimmune Hepatitis Group corresponded to the category of probable AIH. Immunohistochemically, histocompatibility leukocyte antigen-DR, which is aberrantly expressed in the damaged bile ducts of PBC, was not found in the injured bile ducts of this case. Laboratory data were much improved by treatment with prednisone, but ursodeoxycholic acid was not effective. Although the possibility of an overlapping syndrome of AIH- and AMA-negative PBC could not be excluded, this case was diagnosed as AIH with CNSDC-like bile duct lesions. 相似文献
39.
Selmi C Ichiki Y Invernizzi P Podda M Gershwin ME 《Clinical reviews in allergy & immunology》2005,28(2):73-81
Primary biliary cirrhosis (PBC) is a chronic cholestatic disease characterized by a striking predominance in female patients
(with most cases diagnosed between ages 40 and 60 yr) as well as serum auto-antibodies to mitochondrial antigens, elevated
serum immunoglobulin M, progressive destruction of intrahepatic bile ducts, and, ultimately, liver cirrhosis and failure (1). The precise mechanisms leading to selective destruction of biliary epithelial cells lining intrahepatic bile ducts are
still unknown, although numerous immunomediated pathways have been proposed. Genetic background appears to be important in
determining susceptibility to the disease (2), but no clear association with alleles in the major histocompatibility complex has been identified. Molecular mimicry either
by infections (3) or xenobiotics (4) has been proposed to be capable of breaking tolerance in genetically predisposed individuals, thus leading to onset of PBC.
This article describes and discusses the available data regarding the immunomediated pathogenesis of PBC (with particular
attention to auto-antibodies and autoreactive T-cells) and presents the recent evidence indicating a role for either xenobiotic
chemicals or novel infectious agents in the induction of the disease. 相似文献
40.
Takahashi K Nakayama Y Horiuchi H Ohta T Komoriya K Ohmori H Kamimura T 《Immunopharmacology and immunotoxicology》2002,24(3):335-347
1Alpha,25-Dihydroxyvitamin D3 (1,25(OH)2D3) has been shown to modulate the production of various cytokines or the expression of certain differentiation markers in human T cells or monocytes. Its effects on neutrophils, however, are poorly understood. In this paper, we show several lines of evidence indicating that neutrophils express functional vitamin D receptors (VDR). Sort-purified neutrophils from human peripheral blood expressed VDR mRNA at a level comparable to that of monocytes. As reported to occur in monocytes, protein expression of CD14 on the cell surface of neutrophils was augmented when the cells were incubated with 1,25(OH)2D3. To investigate the physiological roles for VDR in neutrophils, we investigated possible modulating effects of 1,25(OH)2D3 on the expression of several genes in lipopolysaccharide-stimulated neutrophils by using differential display analysis. Of the genes we identified, trappin-2/elafin/SKALP, which was originally reported to be an inhibitor of elastase, was induced in neutrophils by lipopolysaccharide, but was suppressed significantly in the presence of 1,25(OH)2D3. Under the same conditions, interleukin-1beta expression was also inhibited. These findings suggest that 1,25(OH)2D3 has a potential to affect the inflammatory process by modulating the expression of neutrophil genes. 相似文献