首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   865篇
  免费   50篇
  国内免费   9篇
耳鼻咽喉   7篇
儿科学   23篇
妇产科学   18篇
基础医学   147篇
口腔科学   28篇
临床医学   80篇
内科学   112篇
皮肤病学   9篇
神经病学   142篇
特种医学   11篇
外科学   42篇
综合类   3篇
预防医学   118篇
眼科学   26篇
药学   101篇
中国医学   5篇
肿瘤学   52篇
  2023年   8篇
  2022年   5篇
  2021年   17篇
  2020年   9篇
  2019年   21篇
  2018年   13篇
  2017年   18篇
  2016年   31篇
  2015年   36篇
  2014年   32篇
  2013年   34篇
  2012年   70篇
  2011年   78篇
  2010年   46篇
  2009年   36篇
  2008年   68篇
  2007年   66篇
  2006年   64篇
  2005年   51篇
  2004年   65篇
  2003年   50篇
  2002年   35篇
  2000年   5篇
  1999年   5篇
  1998年   2篇
  1997年   7篇
  1996年   5篇
  1995年   5篇
  1994年   2篇
  1993年   3篇
  1992年   1篇
  1991年   3篇
  1990年   1篇
  1989年   3篇
  1988年   4篇
  1987年   1篇
  1986年   3篇
  1984年   2篇
  1983年   3篇
  1981年   2篇
  1980年   2篇
  1979年   1篇
  1976年   1篇
  1974年   1篇
  1973年   1篇
  1971年   1篇
  1970年   1篇
  1969年   2篇
  1968年   1篇
  1964年   2篇
排序方式: 共有924条查询结果,搜索用时 750 毫秒
1.
We present the case of a 74-year-old Caucasian female who suffered sudden visual loss after routine phacoemulsification cataract surgery. The patient was subsequently diagnosed with non-arteritic anterior ischaemic optic neuropathy. The case is described in detail, and a concise review of the literature is presented together with the authors’ view on the subject outlined. This is a very rare complication after cataract surgery even in high-risk patients with associated systemic co-morbidities. We suspect that the previous history of obesity, coronary artery disease, and arteriosclerosis contributed to the development of this serious ocular complication. We suggest appropriate measures to reduce the risk of its occurrence.  相似文献   
2.
3.
Stenosis of the hypopharyngo-oesophageal junction can be a rare complication of laryngectomy and/or partial pharyngectomy and makes the insertion of voice prosthesis extremely difficult. This study describes the authors’ experiences gained by endoscopic balloon-catheter dilatation of hypopharyngo-oesophageal stenoses prior to implantation of voice prostheses in four cases. In two patients a single balloon-catheter dilatation resulted in wide enough pharyngo-oesophageal lumen on the long run. The average prosthesis wearing-times were 6.8 months in case 1 and 4.6 months in case 2, corresponding to the published literature data. In case 3, repeated dilatation of the pharyngo-oesophageal transition had proved to be unsuccessful despite taking every effort with the endoscopic balloon-catheter method. Having excised the stenotic segment, reconstruction with pectoralis major myocutaneous flap (PMMF) was indicated. Eighteen months later, a repeated restenosis was observed and a free jejunal flap needed to be performed as a final solution. In case 4, the insertion was carried out into a previously dilated jejunal free flap, which became gradually ischemic and stenotic since the major head-and neck procedure was carried out that resulted in prosthesis rejection after just 1 week. The authors emphasize that correct indication of pedicled and free flaps in head and neck reconstruction is a prerequisite from the aspect of prevention of pharyngo-oesophageal strictures. Endoscopic balloon-catheter dilatation is a safe and established method for dilatating hypopharyngo-oesophageal stenoses of different origin. The procedure provides maximum patient benefit with minimal trauma and morbidity; moreover, facilitates insertion of voice prostheses. However, a single balloon-catheter dilatation cannot always result in wide enough oesophageal lumen on the long run (case 3). Insertion of a voice prosthesis into a previously dilated ischemic jejunal segment is challenging and avoidable due to risks of complications.  相似文献   
4.
The effect of bile on the development of 1,2-dimethylhydrazine (DMH)-induced colon cancer was studied in male Wistar rats. Experimental operative models were created, in which in Group 1, the half intestinal tract, the ileum, and the right side of colon were released from bile. In Group 2, both sides of the colon contained bile. The sham operated animals formed Group 3. These techniques changed the concentration of bile acid in different parts of the colon, and the daily total fecal bile acid excretion as well. After DMH treatment, the relationship between these changes of bile acid level and the development of colon cancer was studied. Significantly more tumors than in the control group were found if the daily total bile acid level and the bile acid concentration in the left side of the colon were increased. Our findings show an unambiguous connection between the fecal bile acid level and the incidence of DMH-induced colon cancer.  相似文献   
5.
PURPOSE: Following ambulatory surgery, long-acting analgesics may provide advantages over short-acting analgesics. This study compared controlled-release codeine (CC) and acetaminophen plus codeine (A/C; 300 mg/30 mg) for pain control in the 48-hr period following laparoscopic cholecystectomy. METHODS: Eligible patients were randomized to CC or A/C in a double-blind, double-dummy parallel group study. Unrelieved pain in hospital was treated with fentanyl i.v. bolus. Pain [100 mm visual analogue scale (VAS)] was assessed before the first dose of medication; at 0.5, one, two, three, and four hours post-dose; at discharge; and three times a day for 48 hr. Adverse events were recorded and measures of patient satisfaction were assessed at the end of the study. RESULTS: Eighty-four patients were enrolled in the study; 42 patients in each group. There were no statistically significant differences between CC and A/C treatment. Mean VAS baseline pain was similar in both groups (P = 0.49) and there was no significant difference in the time to onset of analgesia (P = 0.17). At 0.5 hr, the mean VAS pain score was significantly reduced from baseline in both groups (P = 0.0001). The VAS pain scores at discharge were reduced 59% and 56% from baseline, respectively (P = 0.61). There was no difference between treatments in the incidence of adverse events and patients reported similar levels of satisfaction. CONCLUSIONS: Controlled-release codeine provides an equivalent onset of analgesia, reduction in postoperative pain, and level of patient satisfaction, to acetaminophen plus codeine, over 48 hr following cholecystectomy, with the advantage of less frequent dosing.  相似文献   
6.
The first pharmacon with proved efficacy for the treatment of patients with the relapsing-remitting or relapsing-progressive form of multiple sclerosis (MS) was interferon-beta1b (IFN-beta1b). In 1996, we started treating 34 relapsing-remitting (RRMS) and 2 relapsing-progressive MS (RPMS) patients with IFN-beta1b. Of these 36 patients, 28 received continuous medication for 6 years. The primary end point of the study was the effect of 6 years of continuous IFN-beta1b treatment on the annual relapse rate, the secondary end point was the change in the progression index during the 6 years, and the tertiary end point was the alteration in the expanded disability status scale (EDSS) score of the patients. Finally, we give the reasons for the dropouts. The relapse rate decreased by 80.62% (p < 0.001), the mean EDSS score increased significantly, by approximately 0.5 points, to 2.21 +/- 1.48 (p = 0.016), and the reduction in the mean progression index was 67.19% (p < 0.001). This increase of < 0.5 point in the EDSS score is appreciably different from the 3-point deterioration expected after 6 years for the natural course of the disease. The significant improvement in the progression index clearly demonstrates that 6 years of IFN-beta1b therapy slowed the progression of the disease, thereby improving the quality of life of these MS patients.  相似文献   
7.
Following up the results of a previous population association study (Lakatos et al. [2000: Mol Psychiatry 5:633-637; Lakatos et al. [2002: Mol Psychiatry 7:27-31]) by analyses based on parental genetic data confirmed the link between infant attachment and the dopamine D4 receptor (DRD4) gene. Extended transmission disequilibrium tests (ETDT) were performed to determine whether biased transmission of exon III 48 basepair repeat alleles occurred to infants displaying disorganized and secure attachment behavior with their mothers. The overall allele-wise TDTs were significant for both groups (P = 0.038 and 0.020, respectively): a trend for preferential transmission of the seven-repeat allele to disorganized infants was observed (TDT(chi)(2) = 3.27, df = 1, P = 0.071), and there was a significant non-transmission of the same allele to securely attached infants (TDT(chi)(2) = 6.00, df = 1, P = 0.014). Analysis of haplotypes of the exon III repeat and the -521 C/T promoter polymorphisms in family trios showed that the transmission bias in the larger secure group was due to the low-rate transmission of the T.7 haplotype containing both the seven-repeat and the -521 T alleles (TDT(chi)(2) = 4.46, df = 1, P = 0.035). This suggests that not carrying the T.7 haplotype of the DRD4 gene may act as a resilience factor in the optimal development of early attachment.  相似文献   
8.
We report the first isolation and characterization of several Enterobacteriaceae strains harboring blaNDM-1, blaOXA-48 and/or blaOXA-181 genes in a Romanian emergency teaching hospital. Between January 2010 and September 2012 nine carbapenemase-producing Enterobacteriaceae strains were identified. The blaNDM-1 gene was present in two Enterobacter cloacae strains, an Escherichia coli and two Klebsiella pneumoniae strains. One of these K. pneumoniae strains also harbored the blaOXA-181 gene. Three other K. pneumoniae strains and one Serratia marcescens carried blaOXA-48.  相似文献   
9.
Aim : To identify sites of FGF-2 action on photoreceptors of the rat retina, by localizing FGFR1 in the intact retina, and to assess the colocalisation of FGF-2 with FGFR1. Methods : Immunohistochemistry and confocal microscopy were used to localise FGF-2 and FGFR1 in cryosections of the rat retina, both normal retina and retina stressed by exposure to bright continuous light (1000 lux, 24 h). Antibodies to synaptophysin (SY), cytochrome oxidase (CO) and opsin were used to relate FGFR1-labelling to synaptic vesicles, mitochondria and the photoreceptor cell membrane. Electron microscopy was used to demonstrate the location of synapses within the outer plexiform layer (OPL). Results : FGFR1 was most prominent in the outer nuclear layer (ONL), as diffuse labelling of photoreceptor cytoplasm and as granules between photoreceptor somas. FGFR1 labelling was also observed in the outer synapse-rich sublayer of the OPL where it colocalised with SY, but not with CO-labelled mitochondria. In stressed retina, both at the edge of normal retina and after light stress, FGFR1 expression was upregulated in both the ONL and the OPL. Colocalisation of FGFR1 with FGF-2 could not be demonstrated in unstressed retina, but was demonstrable in stressed retina, in both the ONL and OPL. Conclusions : FGFR1 is prominent in the cytoplasm of photoreceptors, and in their axon terminals, where it is closely associated with synaptic vesicles. Colocalisation of FGFR1 and FGF-2 could be demonstrated in stressed retina, in the cytoplasm and the axon terminals of photoreceptors. The known protective action of FGF-2 may be exerted at the photoreceptor soma. The action of FGF-2 in inhibiting the ERG b-wave may be exerted at the axon terminal.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号