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   5524篇
  免费   404篇
  国内免费   53篇
耳鼻咽喉   32篇
儿科学   140篇
妇产科学   138篇
基础医学   824篇
口腔科学   113篇
临床医学   512篇
内科学   1284篇
皮肤病学   159篇
神经病学   667篇
特种医学   207篇
外科学   510篇
综合类   8篇
一般理论   1篇
预防医学   278篇
眼科学   58篇
药学   407篇
中国医学   26篇
肿瘤学   617篇
  2024年   1篇
  2023年   90篇
  2022年   76篇
  2021年   307篇
  2020年   205篇
  2019年   262篇
  2018年   243篇
  2017年   184篇
  2016年   212篇
  2015年   239篇
  2014年   269篇
  2013年   353篇
  2012年   505篇
  2011年   468篇
  2010年   236篇
  2009年   221篇
  2008年   369篇
  2007年   347篇
  2006年   328篇
  2005年   250篇
  2004年   251篇
  2003年   198篇
  2002年   165篇
  2001年   28篇
  2000年   14篇
  1999年   11篇
  1998年   26篇
  1997年   13篇
  1996年   9篇
  1995年   12篇
  1994年   8篇
  1993年   8篇
  1992年   8篇
  1991年   11篇
  1990年   5篇
  1989年   3篇
  1987年   4篇
  1986年   1篇
  1985年   4篇
  1984年   7篇
  1983年   7篇
  1982年   5篇
  1981年   6篇
  1980年   2篇
  1979年   2篇
  1977年   5篇
  1976年   3篇
排序方式: 共有5981条查询结果,搜索用时 116 毫秒
1.
2.
3.
Purpose: To evaluate the rate and onset of intraoperative and postoperative complications post-phacoemulsification. Methods: One hundred sixty-two eyes of 145 patients with uveitis who underwent phacoemulsification between 2006 and 2009 were identified through surgical record review. Fifty-nine eyes of 46 patients met the inclusion criteria. Hazard ratio (HR) and Kaplan-Meier survival probability were calculated for each class of uveitis. Results: Macular edema (ME) resulted to be associated to chronic postoperative inflammation (r?=?0.6; p?=?0.00) and mostly related to patients who presented more than one postoperative relapse/year (r?=?0.2; p?=?0.02). Fuchs uveitis resulted to be a risk factor for posterior capsule opacification (PCO) (HR 3.36 IC95%1.0-10.5; p?=?0.03). Hypotony and elevated intraocular pressure (IOP) were detected in the anterior uveitis group (0.02 EY). Conclusion: The HR to develop ME was significantly related to chronic anterior uveitis. PCO and elevated IOP are most frequent in Fuchs uveitis. The postoperative visual acuity result was good among all the uveitis groups.  相似文献   
4.
Protracted or recurrent pain and inflammation in the early neonatal period may cause long-lasting changes in central neural function. However, more research is necessary to better characterize the long-term behavioral sequelae of such exposure in the neonatal period. Objectives: (1) to study whether timing of postnatal exposure to persistent inflammation alters responsiveness to thermal pain in the adult animal; (2) to assess whether animals experiencing early postnatal chronic inflammation display altered anxiety related behavior; (3) to study the importance of genetic background. Newborn mice (outbred strain, CD1 and F1 hybrid strain, B6C3F1) received an injection of Complete Freund's Adjuvant (CFA) or saline on either postnatal day 1 or 14 (PND1; PND14) into the left hind paw. Pain to radiant heat and anxiety were examined in 12-week-old adult animals. Adult baseline PWL was significantly decreased in CD1 mice exposed to CFA on PND 1 and 14 as compared to their saline treated counterparts. B6C3F1 mice exposed to CFA on PND14 showed markedly reduced baseline PWL compared to the PND14 saline group. Persistent inflammation experienced by B6C3F1 mice on PND1 failed to affect baseline adult thermal responsiveness. Adult mice, CD1 and B6C3F1, displayed low anxiety traits only if they had been exposed to persistent inflammation on PND1 and not on PND14. Our research suggests a role for genetic background in modulating long-term behavioral consequences of neonatal persistent inflammation: the data support the hypothesis that pain experienced very early in life differentially affects adult behavioral and emotional responsiveness in outbred (CD1) and hybrid mice (B6C3F1).  相似文献   
5.
Objectives: To illustrate endoscopic techniques used in the treatment of esthesioneuroblastoma and to advocate this method of management followed by radiation therapy in selected cases. Methods: A retrospective case series of 10 patients with esthesioneuroblastomas treated between 1999 and 2004 at a tertiary referral center using endonasal techniques. Results: Mean age of patients at presentation was 56.2 years (median 57 years). Seven patients were female and 3 patients were male. Kadish staging at presentation was: A - 3 patients, B - 5 patients, C - 2 patients. Dulguerov stage at presentation was: T1 - 4 patients, T2 - 4 patients, T3 - 2 patients. The period of follow-up ranged from 11 months to 74 months (mean 38.1 months, median 39 months). To date no recurrence has developed in any patient. Conclusions: Our experience suggests that endoscopic surgery can be an effective method of management. Strict attention to selection criteria, careful surgical techniques, and regular follow-up are key elements for success.  相似文献   
6.
Forty-four evaluable patients with intracranial meningiomas were assessed for the expression of the cell-cycle regulator cyclin D1 and of proteins involved in proliferation and apoptosis such as PCNA, MIB-1, p53 and bcl-2. Analyses were carried out by western blot and immunohistochemistry after immediate processing of fresh tumor specimens. By western blot, expression of cyclin D1 significantly correlated with p53 (p=0.02) and with proliferative activity, as assessed by PCNA expression (p=0.0009). By immunohistochemistry, a significant relationship between cyclin D1 and the proliferation marker MIB-1 was confirmed (p=0.05), whereas significance with bcl-2 expression was not found (p=0.01). Moreover, although the association with tumor grade appeared of borderline statistical significance (p=0.07), all the grade II/III meningiomas showed increased expression of cyclin D1 and high proliferative activity. In conclusion, data from this preliminary study seem to suggest a potential value of the combined expression of cyclin D1 and proliferation indicators in defining subgroups of meningiomas with a more aggressive biological behavior.  相似文献   
7.
The content of dolichol, an isoprenoid present in all biological membranes, was determined in isolated sinusoidal liver cells after treatment of rats for 2 and 4 months with a low dosage of the hepatotoxin thioacetamide. The significant decrease in dolichol observed in hepatocytes after 2 months might be explained by peroxidation of the isoprenoid. At the same time point, retinol was retained, and decreased only after 4 months of treatment. After 4 months of treatment therefore both lipids decreased. In a subfraction of hepatic stellate cells, Ito-1 cells, the main storage site of vitamin A, dolichol decreased significantly only after 4 months. A remarkable difference from hepatocytes is that in Ito-1 cells retinol content significantly decreased after 2 months of treatment. In another subfraction, Ito-2 cells, the content of the two isoprenoids decreased in parallel. This heterogeneous subfraction might represent those transitional hepatic stellate cells that, while losing retinol, are in the process of differentiating into myofibroblasts secreting extracellular matrix components. In Kupffer cells and sinusoidal endothelial cells, impairment of dolichol might be observed later, only after 4 months of treatment, while retinol decreases uniformly over time. Starting after two months of treatment, the decrease of dolichol and the increase of retinol in hepatocytes, at the same time as retinol decreases in hepatic stellate cells, might be taken as an early index of incipient liver injury due to thioacetamide. This hypothesis is discussed with regard to a role of dolichol in the modulation of membrane fluidity for intracellular and intercellular retinol transport.  相似文献   
8.
In October 1990 pneumonia due toLegionella pneumophila was diagnosed in two employees working in the area of Apulia, southern Italy, where artesian wells were in construction. Although the exposure to excavation has been associated with Legionnaires' disease, in our investigation the illness occurred only in those employees who were present when the water emerged from the ground under high pressure. On the basis of this report, water appears as the most likely reservoir of the organism and the main route of infection.Corresponding author.  相似文献   
9.
PDB is genetically heterogeneous. Mutations of the sequestosome1 gene have been reported in sporadic and familial forms of Paget's in patients of French Canadian and British descent. Mutational analyses in different ethnic groups are needed to accurately investigate hereditary diseases. We describe two novel mutations of sequestosome1 in 62 Italian sporadic patients, confirming the role of the encoded protein in this disorder. INTRODUCTION: Paget's disease of bone (PDB) is a relatively common disease of bone metabolism reported to affect up to 3% of whites over 55 years of age. The disorder is genetically heterogeneous, and at present, there is scientific evidence that at least eight different human chromosomal loci are correlated with its pathogenesis. Mutations of the sequestosome1 (SQSTM1) gene were identified as responsible for most of the sporadic and familial forms of Paget in patients of French Canadian and British descent. Such mutations were located at exon 7 and 8 levels, encoding for the ubiquitin protein-binding domain (UBA) and representing a mutational hot spot area. MATERIALS AND METHODS: To verify the involvement of this gene in Italian subjects affected by PDB, we performed mutational analysis in 62 sporadic PDB cases. RESULTS: We described three different mutations at exon 8 level: P392L, already described in the French Canadian population and families predominantly of British descendent, and two novel mutations consisting of the amino acid substitutions M404V and G425R. No significant differences in the clinical history of PDB have been observed in patients with SQSTM1 mutations in respect to those without. CONCLUSIONS: Even though our findings suggest a minor involvement of the SQSTM1 gene in the pathogenesis of sporadic Italian Paget's cases, the identification of different significant mutations within the SQSTM1 gene in unrelated, but clinically similar individuals, offers extremely convincing evidence for a causal relationship between this gene and PDB. Longitudinal studies are needed to assess the penetrance of genotype/phenotype correlations. Our findings confirm the evidence of a clustered mutation area at this level in this disorder.  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