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   2040篇
  免费   140篇
  国内免费   96篇
耳鼻咽喉   4篇
儿科学   150篇
妇产科学   50篇
基础医学   195篇
口腔科学   28篇
临床医学   318篇
内科学   421篇
皮肤病学   87篇
神经病学   59篇
特种医学   116篇
外科学   167篇
综合类   78篇
预防医学   69篇
眼科学   79篇
药学   147篇
中国医学   21篇
肿瘤学   287篇
  2023年   20篇
  2022年   24篇
  2021年   35篇
  2020年   43篇
  2019年   31篇
  2018年   53篇
  2017年   42篇
  2016年   30篇
  2015年   33篇
  2014年   60篇
  2013年   77篇
  2012年   68篇
  2011年   75篇
  2010年   83篇
  2009年   54篇
  2008年   80篇
  2007年   131篇
  2006年   82篇
  2005年   86篇
  2004年   68篇
  2003年   64篇
  2002年   60篇
  2001年   54篇
  2000年   39篇
  1999年   44篇
  1998年   42篇
  1997年   61篇
  1996年   44篇
  1995年   47篇
  1994年   40篇
  1993年   30篇
  1992年   34篇
  1991年   26篇
  1990年   38篇
  1989年   41篇
  1988年   33篇
  1987年   25篇
  1986年   29篇
  1985年   22篇
  1984年   15篇
  1983年   18篇
  1982年   13篇
  1981年   14篇
  1977年   11篇
  1976年   13篇
  1975年   9篇
  1966年   9篇
  1965年   12篇
  1963年   11篇
  1959年   13篇
排序方式: 共有2276条查询结果,搜索用时 15 毫秒
31.
目的:探讨感染性心内膜炎(IE)的病因,致病微生物的变迁及抗生素的选择。方法:对1995年5月~2003年8月间住院的30例IE患者的临床资料进行回顾性分析。结果:风湿性心脏瓣膜病为其主要的基础心脏病变。链球菌在致病微生物中依然居首位,但凝固酶阴性葡萄球菌(CNS)等其它菌种逐渐增多,且对青霉素耐药发生率高,为临床诊治造成困难。结论:对于IE患者应尽可能早期明确诊断,早期选用有效的抗生素。CNS在IE的致病微生物中的地位有待进一步提高。  相似文献   
32.
目的 探讨延续性护理在心脏瓣膜置换术患者中的应用效果.方法 选取2017年1月—2019年1月在四川省德阳市人民医院接受心脏瓣膜置换术治疗的80例瓣膜性心脏病患者作为研究对象,随机分为观察组和对照组各40例.出院后对照组不进行主动护理,观察组采用延续性护理,对两组患者干预前后服药依从性、生活质量及心功能进行比较分析.结果 出院时两组服药依从性、生活质量及心功能比较差异无统计学意义(P>0.05),出院后6个月观察组服药依从性、生活质量及心功能均优于对照组,差异有统计学意义(P<0.05).结论 延续性护理应用于心脏瓣膜置换术出院患者中可提高患者服药依从性,提升患者生活质量及心功能恢复,值得临床借鉴推广.  相似文献   
33.
Objective To investigate the clinical and pathological characteristics of pauci-immune crescent glomerulo~nephritis (PICGN) in Chinese patients. Methods During 13 years (1985-1998), 6400 patients underwent non-transplanting renal biopsy. Twenty-four patients were diagnosed as PICGN. All clinical and laboratory data of these patients were collected from the patients’ records and used for detailed analysis. The diagnosis is based on clinico-pathologic findings. Results Of the 24 patients, 16 were females and 8 were males, with median age of 33 years (ranged 10-76 years). Microscopic polyarteritis (MPA) (33.3%) and systemic vasculitis (8.3%) were the secondary diseases. The incidence of PICGN was 0.38% in renal biopsies and 22.9% in crescentic glomerulonephritis. Clinically, most patients (75.0%) showed rapidly progressive nephritis with enlarged kidneys. At onset, gross hematuria was noted in 58.3% of patients, hypertension in 45.8%, nephrotic syndrome in 41.7%, and oliguria in 25.0%. However, systemic symptoms were rare except for anemia. Pathologically, necrosis of glomerular capillaries (62.5%), infiltration of monocytes and neutrophil cells in glomeruli (66.7%), and vasculitis in the interstitium (53.3%) were observed. In addition, glomerulosclerosis was noted in 45.8%, severe tubular atrophy in 83.3% and interstitial fibrosis in 75.0%. Anti-neutrophil cytoplasmic antibodies (ANCAs) were positive in 52.2%. All patients except two received intensively immunosuppressive therapy. Sixteen patients were available for long-term follow up (median 29.8 months, range 8-92 months). Twelve of them had life-sustaining renal function, four had normal serum creatinine (&lt;124?μmol/L) and only 4 patients were dialysis-dependent. Conclusion PICGN is not rare in China. Early diagnosis and administration of immunosuppressive therapy, particularly in patients with rapidly progressive glomerulonephritis (RPGN), are important for good prognosis.  相似文献   
34.
含抗生素骨水泥假体在人工关节术后感染中的应用   总被引:3,自引:0,他引:3  
目的 回顾分析含抗生素骨水泥假体(PROSTALAC)治疗人工关节置换术后感染的疗效。方法 对16例髋和膝关节置换术后感染的病例采用PROSTALAC方法,进行二期翻修治疗并进行随访。结果 16例髋和膝关节置换术后感染中,有14例于治疗后接受二期全髋或全膝关节翻修术,经平均46月的随访,感染无复发,成功率达87.5%。术后Harris髋关节评分平均达82.9分,膝关节评分平均达90.5分。结论 在PROSTALAC基础上进行的二期全髋和全膝关节翻修手术能成功地治疗人工关节术后感染,并且保持术后关节的功能。  相似文献   
35.
Oral melatonin is a potential alternative treatment for hypertension and nocturnal hypertension. However, high‐quality and relevant meta‐analyses are lacking. This meta‐analysis aimed to investigate whether oral melatonin supplementation reduces daytime/asleep blood pressure and cardiovascular risk, improves sleep quality, and is well‐tolerated compared with placebo. Relevant articles were searched in multiple databases, including MEDLINE, EMBASE, CINAHL Complete, and the Cochrane Library, from their inception to June 2021. The included studies were randomized controlled trials recruiting patients with hypertension, using oral melatonin as the sole intervention, and investigating its effect on blood pressure. The mean out‐of‐office (including 24‐h, daytime, and asleep) systolic and diastolic blood pressures, sleep quality, and side effects were compared between the melatonin and placebo arms using pairwise random‐effect meta‐analyses. A risk of bias assessment was performed using the Cochrane risk‐of‐bias tool. Four studies were included in the analysis and only one study was considered to have a low risk of bias. No study reported on cardiovascular risk or outcomes. Only controlled‐release melatonin (not an immediate‐release preparation) reduced asleep systolic blood pressure by 3.57 mm Hg (95% confidence interval: –7.88 to .73; I= 0%). It also reduced asleep and awake diastolic blood pressure, but these differences were not statistically significant. Melatonin improves sleep efficacy and total sleep time and is safe and well‐tolerated. Due to the limited number of high‐quality trials, the quality of evidence was low to very low. Therefore, adequately powered randomized controlled trials on melatonin are warranted.  相似文献   
36.
Context  Little is known about the incidence of secondary neoplasms after 15 to 20 years in children and adolescents who were treated for acute lymphoblastic leukemia. Objectives  To investigate the cumulative incidence of secondary neoplasms in pediatric patients treated for acute lymphoblastic leukemia over 30 years and to characterize late-occurring tumors. Design, Setting, and Patients  Retrospective study of 2169 patients with acute lymphoblastic leukemia treated between 1962 and 1998 at St Jude Children's Research Hospital, Memphis, Tenn, who achieved complete remission and had a median follow-up time of 18.7 years (range, 2.4-41.3 years). Main Outcome Measures  Cumulative incidences of secondary neoplasms in first remission and standard incidence ratios of observed rates compared with rates of cancer development in the general US population. Results  Secondary neoplasms developed as the first event in 123 patients and comprised 46 myeloid malignancies, 3 lymphomas, 14 basal cell carcinomas, 16 other carcinomas, 6 sarcomas, 16 meningiomas, and 22 other brain tumors. The cumulative incidence of secondary neoplasm was 4.17% (SE, 0.46%) at 15 years and increased substantially after 20 years, reaching 10.85% (SE, 1.27%) at 30 years. When meningiomas and basal cell carcinomas were excluded, the overall cumulative incidence was 3.99% (SE, 0.44%) at 15 years and 6.27% (SE, 0.83%) at 30 years, representing a 13.5-fold increase in overall risk compared with the general population. The cumulative incidence of each tumor type at 30 years was 2.19% (SE, 0.32%) for myeloid malignancy, 0.17% (SE, 0.10%) for lymphoma, 3.00% (SE, 0.59%) for brain tumor, 4.91% (SE, 1.04%) for carcinoma, and 0.57% (SE, 0.37%) for sarcoma. Conclusions  The cumulative incidence of secondary neoplasms increases steadily over 30 years after treatment of acute lymphoblastic leukemia. Although the majority of the late-occurring secondary neoplasms are low-grade tumors, the increase in incidence of more aggressive malignant neoplasms is significantly higher than expected in the general population. These results suggest that lifelong follow-up of acute lymphoblastic leukemia survivors is needed to ascertain the full impact of treatment and other leukemia-related factors on secondary neoplasm development.   相似文献   
37.
C Li  VW Liu  PM Chiu  DW Chan  HY Ngan 《BMC cancer》2012,12(1):357
ABSTRACT: BACKGROUND: AMP-activated protein kinase (AMPK) has recently been considered as a potential target for cancer therapy. However, the expression status of various subunits of the heterotrimeric AMPK in human cancers is rarely reported. We decided to determine their expressions in ovarian carcinomas and their relationships with the disease. METHODS: Expressions and locations of the AMPK-alpha1, -alpha2, -beta1, -beta2, -gamma1 and -gamma2 were detected by quantitative PCR (Q-PCR) and immunohistochemical staining (IHC). Their expression levels in ovarian tumors were compared with normal controls and also correlated with clinicopathological parameters. RESULTS: Except AMPK-alpha1, expressions of the other five AMPK subunits are significantly higher in ovarian carcinomas as determined by Q-PCR. Although IHC detection of AMPK-gamma1 and -gamma2 were not successful, over-expressions of AMPK-alpha2, -beta1, and -beta2 were further confirmed by IHC. Over-expressions of various AMPK subunits occurred independently and were mainly detected in the cytoplasm. Interestingly, AMPK-alpha2 and -beta1 were also detected in the nucleus and cell membrane, respectively. Clinical correlation analyses indicate that expressions of different AMPK subunits are associated with different subtypes of carcinoma. High expression of AMPK-alpha2 is significantly associated with endometrioid carcinomas. On the other hand, high expressions of AMPK-beta and -gamma subunits are associated with mucinous and serous carcinomas, respectively. Furthermore, high expressions of AMPK-beta1 and -gamma2 are also associated with early and late stages of disease, respectively. Finally, patients with high expression of AMPK-alpha2 had better prognosis. CONCLUSIONS: Aberrant expressions of AMPK subunits may play important roles in ovarian carcinogenesis. Each AMPK subunit may have its own function other than just a component of the AMPK molecule. Correlations with clinical parameters suggest that expressions of AMPK subunits have different clinical implications in ovarian cancer development.  相似文献   
38.
39.
40.
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