全文获取类型
收费全文 | 27102篇 |
免费 | 1862篇 |
国内免费 | 245篇 |
专业分类
耳鼻咽喉 | 424篇 |
儿科学 | 421篇 |
妇产科学 | 602篇 |
基础医学 | 3947篇 |
口腔科学 | 702篇 |
临床医学 | 2327篇 |
内科学 | 5241篇 |
皮肤病学 | 582篇 |
神经病学 | 2008篇 |
特种医学 | 1601篇 |
外科学 | 4375篇 |
综合类 | 284篇 |
一般理论 | 11篇 |
预防医学 | 1100篇 |
眼科学 | 662篇 |
药学 | 2353篇 |
1篇 | |
中国医学 | 272篇 |
肿瘤学 | 2296篇 |
出版年
2023年 | 132篇 |
2022年 | 289篇 |
2021年 | 724篇 |
2020年 | 392篇 |
2019年 | 668篇 |
2018年 | 723篇 |
2017年 | 595篇 |
2016年 | 693篇 |
2015年 | 1032篇 |
2014年 | 1277篇 |
2013年 | 1451篇 |
2012年 | 2166篇 |
2011年 | 2135篇 |
2010年 | 1312篇 |
2009年 | 1196篇 |
2008年 | 1641篇 |
2007年 | 1570篇 |
2006年 | 1469篇 |
2005年 | 1394篇 |
2004年 | 1258篇 |
2003年 | 1090篇 |
2002年 | 959篇 |
2001年 | 774篇 |
2000年 | 759篇 |
1999年 | 600篇 |
1998年 | 210篇 |
1997年 | 202篇 |
1996年 | 176篇 |
1995年 | 147篇 |
1994年 | 126篇 |
1993年 | 102篇 |
1992年 | 242篇 |
1991年 | 185篇 |
1990年 | 176篇 |
1989年 | 168篇 |
1988年 | 143篇 |
1987年 | 104篇 |
1986年 | 96篇 |
1985年 | 69篇 |
1984年 | 78篇 |
1983年 | 49篇 |
1982年 | 52篇 |
1981年 | 44篇 |
1980年 | 43篇 |
1979年 | 56篇 |
1978年 | 44篇 |
1977年 | 46篇 |
1974年 | 37篇 |
1972年 | 44篇 |
1971年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 343 毫秒
991.
Nationwide epidemiology and prognosis of dialysis‐requiring acute kidney injury (NEP‐AKI‐D) study: Design and methods
下载免费PDF全文
![点击此处可从《Nephrology (Carlton, Vic.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Chih‐Chung Shiao Pei‐Chen Wu Vin‐Cent Wu Jui‐Hsiang Lin Heng‐Chih Pan Ya‐Fei Yang Tai‐Shuan Lai Tao‐Min Huang Che‐Hsiung Wu Wei‐Shun Yang Chih‐Jen Wu Chih‐Chin Kao Chiao‐Yin Sun Chun‐Te Huang Kuo‐Hua Lee Chan‐Yu Lin Te‐Chuan Chen Fu‐Chang Hu Hung‐Hsiang Liou Kuo‐Cheng Lu Kuo‐Liong Chien Jian‐Jhong Wang Wei‐Chih Kan Feng‐Chi Kuo Hugo You‐Hsien Lin Cheng‐Min Chen Zi‐hong You Jen‐Pi Tsai Chih‐Jen Weng Hung‐Yuan Chen Chao‐Fu Chang Wen‐Ding Hsu Mai‐Szu Wu Chiu‐Ching Huang Kwan‐Dun Wu 《Nephrology (Carlton, Vic.)》2016,21(9):758-764
992.
Amidi F French BA Chung D Halsted CH Medici V French SW 《Experimental and molecular pathology》2007,83(3):296-300
M-30 and 4HNE adducts are two markers of active liver disease. M-30 is a serologic marker and 4HNE adducts are histologic markers. M-30 is a marker for apoptosis because it is a fragment of cytokeratin-18 left over from proteolysis by caspase 3. 4HNE is a marker of oxidative stress because it results from lipid peroxidation. Both markers are commonly found in nonalcoholic steatohepatitis and in alcoholic hepatitis. Liver biopsies from patients with steatohepatitis, 11 alcoholic and 11 non-alcoholics were stained for 4HNE and M-30. Almost all of the biopsies in both groups showed 4HNE- and M-30-positive aggresomes in hepatocytes. Mallory Denk bodies (MDB) stained variably positive for M-30, whereas 4HNE was present in aggresomes independent of MDBs. However, they were sometimes located in hepatocytes which also contained MDBs as shown by confocal microscopy of double stained biopsies. The results indicate that the formation of M-30 and 4HNE aggresomes occurs through different pathways of liver cell injury in both types of steatohepatitis. 相似文献
993.
Neonatal maternal separation (NMS) has been shown to trigger alterations in neuroendocrine, neurochemical and sensory response to nociceptive stimuli along the brain-gut axis. These alterations may be the result of a cascade of events that are regulated by neurotrophic factors. Nerve growth factor (NGF), a member of the neurotrophin family, is essential for the development and maintenance of sensory neurons and for the formation of central pain circuitry. The present study aimed to investigate whether NMS causes changes in neuronal plasticity and the relationship of these changes in plasticity with the expression of NGF and its high affinity tyrosine kinase receptor A (TrkA) in the lumbosacral spinal cord in adult rats. Male Wistar rat pups were either subjected to 180 min daily of NMS or not handled (NH) for 13 consecutive days. The expression of NGF and TrkA was examined in NH and NMS rats with or without colorectal distention (CRD) as determined by Western blot analysis and immunohistochemistry. The present results of Western blot analysis indicated NMS and CRD have a significant effect on NGF protein level in the lumbosacral spinal cord of rats. Assessments of optical densities revealed that NMS enhanced TrkA-ir fiber densities in laminae I-III and laminae V-VI of rats in both conditions with or without CRD. Double immunofluorescence revealed that TrkA co-expressed with calcitonin gene-related peptide (CGRP) in afferent fibers, while no significant difference in terms of the intensity of TrkA-ir in these fibers was found among groups. Quantitative analysis of TrkA-ir neurons indicated a significant interactive effect of NMS and CRD on the mean number of TrkA-ir neurons in laminae V-VI of rats, in which significant difference was found between NMS+CRD and NH+CRD. Double immunofluorescence of TrkA and Fos showed that CRD has a significant effect on TrkA expression in Fos-positive neurons in laminae V-VI and lamina X of rats, while no significant difference was found between NMS+CRD and NH+CRD. These results demonstrate that NMS induced alterations in NGF protein level and TrkA expression in adult rat spinal cord and indicate that NGF is a crucial mediator for the changes in neuronal plasticity that occur in NMS-induced visceral hyperalgesia. 相似文献
994.
Inflammation and dephosphorylation of the tight junction protein occludin in an experimental model of multiple sclerosis 总被引:3,自引:0,他引:3
Morgan L Shah B Rivers LE Barden L Groom AJ Chung R Higazi D Desmond H Smith T Staddon JM 《Neuroscience》2007,147(3):664-673
Multiple sclerosis (MS) is a disease of the CNS in which inflammation, demyelination and neurodegeneration contribute to its initiation and progression. A frequently employed model of MS is experimental autoimmune encephalomyelitis (EAE). Here, to gain new insights into the disease process, an analysis of proteins in extracts of lumbar spinal cord from naïve and EAE rats was undertaken. The data mainly confirm that inflammation and blood–brain barrier (BBB) breakdown are the major hallmarks of disease in this model. Given their importance in the BBB, junctional proteins were further investigated. Occludin, a protein localizing to tight junctions in brain endothelial cells, showed strikingly increased migration in EAE when analyzed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE). This increased migration was mimicked by in vitro phosphatase treatment, implying its dephosphorylation in EAE. Occludin dephosphorylation coincided with the onset of inflammation, slightly preceding visible signs of disease, and was just prior to apparent changes in BBB permeability. These findings suggest occludin is a target for signaling processes in EAE, perhaps regulating the response of the BBB to the inflammatory environment as seen in MS. 相似文献
995.
Optimal ICSI timing after the first polar body extrusion in in vitro matured human oocytes 总被引:3,自引:0,他引:3
Hyun CS Cha JH Son WY Yoon SH Kim KA Lim JH 《Human reproduction (Oxford, England)》2007,22(7):1991-1995
BACKGROUND: This study was conducted to investigate the fertilization and embryo development of human oocytes injected at different time intervals after extrusion of the first polar body (PB) following in vitro maturation (IVM) in IVM cycles. Also, we evaluated whether spindle imaging could serve as a tool to determine the optimal ICSI time. METHODS: Oocytes were collected from 43 women with polycystic ovary syndrome. Metaphase I (MI) oocytes after in vitro culture for 24 h from germinal vesicle stage were subjected to ICSI according to time after first PB extrusion. The intervals were: within 1 h (n=38); 1-2 h (n=30); 2-4 h (n=26);4-6 (n=28) and 6-8 h (n=40). In some MI oocytes, viable spindle location was evaluated using Polscope microscopy at different time intervals after first PB extrusion. RESULTS: Fertilization rate of the MI oocytes injected within 1 h after first PB extrusion was low (15.8; 6/38) (P<0.01 versus all other times). In contrast, the fertilization rate was 80, 92.3, 82.1 and 85% for oocytes injected 1-2, 2-4, 4-6 and 6-8 h after first PB extrusion, respectively. Development of good-quality embryos was not significantly different among all the groups. Interestingly, all the oocytes injected within 1 h after first PB extrusion were in Telophase I. CONCLUSIONS: Human oocytes matured in vitro needed at least 1 h after first PB extrusion to complete nuclear maturation. Use of a live spindle imaging system can help to decide the timing of ICSI for oocytes matured in vitro. 相似文献
996.
997.
998.
Chemically synthesized small interfering RNA (siRNA) has been used as an anti-coxsackievirus B3 (CVB3) agent. Herein, we investigated whether vector-derived short hairpin RNAs (shRNA) targeting CVB3 can exert antiviral activities, prior to their further application to viral vector system for efficient in vivo administration. Employing transient transfection assays to in vivo mouse models as well as to in vitro Cos-7 cell cultures, we directly demonstrated the potential antiviral activity of shRNAs following challenges with infectious CVB3. Of the six shRNAs that we designed, three prevented cell death from CVB3 infection by suppressing viral replication and viral production in Cos-7 cells. These were shRNA 2, which targeted the capsid protein VP1, and shRNAs 4 and 5, which targeted two different regions of the RNA-dependent RNA polymerase 3D. Furthermore, shRNAs 2 and 5 also exerted strong antiviral effects in viral replication in vivo, accompanied by attenuated pancreatic tissue damage. Through this direct evaluation system we addressed the development and application of vector-derived shRNAs as an anti-CVB3 agent, revealing new target sequences. 相似文献
999.
1000.
PURPOSE: Lamivudine is known to be very effective in suppressing hepatitis B virus replication and virus induced necroinflammation. The aim of this study was to evaluate lamivudine therapy efficacy, predictive factors, breakthrough, prevalence of YMDD mutation, and relapse rate in Korean children with chronic hepatitis B. MATERIALS AND METHODS: Between August 1999 and February 2005, 60 children on lamivudine therapy for chronic hepatitis B were enrolled. Treatment response was defined as alanine aminotransferase (ALT) normalization, and HBeAg and HBV-DNA disappearance. RESULTS: Seroconversion rates of HBeAg and HBV- DNA were 42% and 53%, respectively, and ALT normalization rate was 88%. Seroconversion rates of HBeAg (60.0%) and anti-HBe (60.0%) were higher in patients younger than 6 years. Seroconversion rate of HBV-DNA (68.4%) and normalization rate of serum ALT (94.7%) were highest in patients between 6 and 12 years. Seroconversion rates of all HBV markers were lowest in patients older than 12 years. Predicted 3 year cumulative seroconversion rates, were 70%, 68% for HBeAg, HBV-DNA, respectively. These were calculated by Kaplan-Meier method. Cox proportional hazard regression model showed that pre-treatment ALT was a positive predictive factor for seroconversion of HBeAg and HBV-DNA. Breakthrough phenomenon was noted in 6 patients, and 3 had a YMDD mutation. CONCLUSION: Lamivudine therapy had a significant effect on HBeAg seroconversion and HBV-DNA disappearance, and ALT normalization for Korean children with chronic hepatitis B. 相似文献