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   857篇
  免费   57篇
  国内免费   7篇
耳鼻咽喉   2篇
儿科学   28篇
妇产科学   25篇
基础医学   93篇
口腔科学   21篇
临床医学   67篇
内科学   237篇
皮肤病学   54篇
神经病学   49篇
特种医学   15篇
外科学   77篇
综合类   3篇
预防医学   70篇
眼科学   18篇
药学   65篇
中国医学   1篇
肿瘤学   96篇
  2023年   5篇
  2022年   22篇
  2021年   40篇
  2020年   29篇
  2019年   30篇
  2018年   33篇
  2017年   23篇
  2016年   28篇
  2015年   30篇
  2014年   41篇
  2013年   55篇
  2012年   61篇
  2011年   71篇
  2010年   39篇
  2009年   29篇
  2008年   57篇
  2007年   51篇
  2006年   42篇
  2005年   51篇
  2004年   44篇
  2003年   48篇
  2002年   39篇
  2001年   2篇
  1999年   1篇
  1998年   4篇
  1997年   5篇
  1996年   4篇
  1995年   5篇
  1994年   1篇
  1993年   6篇
  1992年   2篇
  1990年   1篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1986年   2篇
  1983年   1篇
  1981年   1篇
  1980年   2篇
  1979年   2篇
  1978年   1篇
  1973年   1篇
  1968年   1篇
  1966年   1篇
  1954年   1篇
  1928年   1篇
  1927年   3篇
  1920年   1篇
排序方式: 共有921条查询结果,搜索用时 31 毫秒
71.
Systemic injections of alcohol have previously been reported to 'prime' or to reinstate self-administration of alcohol in rats, and it has been suggested that the priming effects of drugs are related to their stimulus properties. We tested this hypothesis by investigating the effects of lorazepam, which cross-generalizes with alcohol in animal drug-discrimination studies, in rats trained to self-administer 7% alcohol in an operant paradigm. Once animals were trained, extinction tests were carried out twice weekly, before which rats were injected with either vehicle, alcohol (0.063-0.5 g/kg, i.p.) or lorazepam (0.03-0.25 mg/kg, i.p.). Alcohol did not increase responding for alcohol during extinction. Doses of 0.25 and 0.5 g/kg reduced alcohol-appropriate lever pressing (p < 0.05 versus 0 g/kg), with the largest dose also suppressing general activity (p < 0.02 versus 0 g/kg). Lorazepam also reduced alcohol-appropriate responding, in a behaviourally specific manner; doses of 0.03 mg/kg and above decreased lever pressing (p < 0.05 versus 0 mg/kg), whereas general activity was depressed at 0.06 mg/kg and larger doses (p < 0.05 versus 0 mg/kg). Although lorazepam mimicked the effect of alcohol at doses predicted to do so on the basis of their relative potency in drug discrimination studies, neither alcohol nor lorazepam primed rats to respond for alcohol. By contrast, the pattern of results suggested that, in this model, they 'satiated' or substituted for alcohol, resulting in a reduced motivation to respond.  相似文献   
72.
The clathrin-associated protein, Huntingtin Interacting Protein 1 (HIP1), is overexpressed in multiple human epithelial tumors. Here, we report that HIP1 is a novel oncoprotein that transforms cells. HIP1-transformed cells, in contrast to RasV12-transformed cells, have dysregulation of multiple receptors involved in clathrin trafficking. Examples include upregulation of the epidermal growth factor receptor (EGFR) and the transferrin receptor. Furthermore, accumulation of transferrin and EGF in the HIP1-transformed cells was increased, and breast tumors that had EGFR expressed also had HIP1 upregulated. Thus, HIP1 overexpression promotes tumor formation and is associated with a general alteration in receptor trafficking. HIP1 is the first endocytic protein to be directly implicated in tumor formation.  相似文献   
73.
Multiple sclerosis (MS) is a demyelinating disorder of the central nervous system (CNS) with a complex genetic background. Here we use a genome-wide association strategy with 4804 microsatellite markers successfully typed in separately pooled DNA from 200 patients and 200 controls. A total of 91 markers showed evidence of association. When compared to our in-house physical map of the genome, six 2-Mb regions containing at least two of these markers were detected. Of those, three regions have one or more markers among the 20 most strongly associated: chromosomes 3q25, 6p21.3 (the MHC region) and 19q13.  相似文献   
74.
Genetic factors are known to influence susceptibility to multiple sclerosis (MS) but the genes involved are largely undefined. Here, we report an association study based on 200 patients and 200 controls from the Porto region in Portugal. A total of 3974 markers were successfully typed from which we have identified 46 markers showing evidence of association. When compared to a physical map three regions were found with two of these markers less than 1.5 Mb apart: chromosomes 6p21.3 (the MHC region), 6q14.1 and 7q34.  相似文献   
75.
76.
77.
The aim of the study was to compare the treatment regimen of three natural surfactants of different extraction and formulation (Alveofact [Surfactant A = SA], Poractant [Surfactant B = SB] and Beractant [Surfactant C = SC]) in neonatal respiratory distress syndrome (RDS). Premature infants of /=0.3 were randomly assigned to receive at least two doses of SA, SB or SC (100 mg/kg per dose). Infants who remained dependent on artificial ventilation with a FiO2 >/=0.3 received up to two additional doses. There were no differences among the groups regarding the necessity for more than two doses. The SA and the SB groups spent fewer days on a ventilator (p-value SA/SB 0.7, SA/SC 0.05, SB/SC 0.043) compared with the SC group, needed fewer days of oxygen administration (p-value SA/SB 0.14, SA/SC 0.05, SB/SC 0.04) and spent fewer days in hospital (p-value SA/SB 0.65, SA/SC 0.04, SB/SC 0.027). There were no statistically significant differences in the incidence of mortality, chronic lung disease, air leaks, necrotising enterocolitis, retinopathy of prematurity and intraventricular haemorrhage among the three groups. CONCLUSION: The Alveofact and Poractant groups spent fewer days on the ventilator, needed fewer days of oxygen administration and spent fewer days in hospital compared with the Beractant group but no differences were observed among the three groups with regards to mortality and morbidity.  相似文献   
78.
Emergency obstetric hysterectomy   总被引:4,自引:0,他引:4  
BACKGROUND: All cases of obstetric hysterectomies that were performed in our hospital during a seven-year study period were reviewed in order to evaluate the incidence, indications, risk factors, and complications associated with emergency obstetric hysterectomy. METHODS: Medical records of 45 patients who had undergone emergency hysterectomy were scrutinized and evaluated retrospectively. Maternal age, parity, gestational age, indication for hysterectomy, the type of operation performed, estimated blood loss, amount of blood transfused, complications, and hospitalization period were noted and evaluated. The main outcome measures were the factors associated with obstetric hysterectomy as well as the indications for the procedure. RESULTS: During the study period there were 32,338 deliveries and 9,601 of them (29.7%) were by cesarean section. In this period, 45 emergency hysterectomies were performed, with an incidence of 1 in 2,526 vaginal deliveries and 1 in 267 cesarean sections. All of them were due to massive postpartum hemorrhage. The most common underlying pathologies was placenta accreta (51.1%) and placenta previa (26.7%). There was no maternal mortality. CONCLUSIONS: Obstetric hysterectomy is a necessary life-saving procedure. Abnormal placentation is the leading cause of emergency hysterectomy when obstetric practice is characterized by a high cesarean section rate. Therefore, every attempt should be made to reduce the cesarean section rate by performing this procedure only for valid clinical indications.  相似文献   
79.
Introduction: The introduction of BRAF and MEK inhibitors into clinical practice improved the prognosis of metastatic melanoma patients. The combination of BRAF inhibitor dabrafenib with MEK inhibitor trametinib has shown its superiority to single agent therapy and is characterized by a tolerable spectrum of adverse events which shows a decrease in incidence over time on treatment.

Areas covered: The current scientific literature on safety and adverse events (AEs) related to BRAF and MEK-inhibition has been investigated with special focus on the large phase 3 studies (COMBI-v, COMBI-d and CoBRIM) as well as recent updates presented at oncology and melanoma meetings. Additionally, published case series/case reports were screened for information on AEs.

Expert opinion: Even though almost every patient (98%) under combination therapy with dabrafenib and trametinib experiences at least one adverse event, these are generally mild to moderate, reversible and can be managed with dose reductions or interruptions. However, due to an increased life expectancy, there is a substantial need to prevent and treat also mild adverse events, as they play a central role for the quality of life of patients. Ongoing clinical trials will have to demonstrate the efficacy as well as safety of triple combination with anti-PD-1/anti-PD-L1 antibodies.  相似文献   

80.
Introduction: Patients with cancer are subject to the cardiotoxic effects of cancer therapy. Improved cancer treatments lead to more cancer-survivors, who though are exposed to various forms of cardiovascular (CV) disease (CVD) as they age. Aging patients are at increased risk of developing both malignancy and CVD or they may have survived some form of CVD as a result of effective CV treatments. Furthermore, patients with CVD may develop cancer and require treatment (and vice versa), all contributing to increased morbidity and mortality. The prevalence of both malignancy and CVD will increase due to the trend toward a longer lifespan.

Areas covered: In part 2 of this review, the discussion of the CV effects of specific oncology drugs is completed with inclusion of additional immunological agents, current hormonal and other agents. Early detection and monitoring of cardiotoxicity, use of biomarkers and other imaging and diagnostic methods and prevention and treatment options are also discussed.

Expert opinion: As outlined in part 1 of this review, oncologists need to be aware of the CV adverse-effects of their treatments and make careful and expectant clinical decisions, especially in patients with preexisting CVD or CV risk factors. Similarly, cardiologists should consider a detailed previous history of treatment for malignant disease, including prior chemotherapy exposure, dose(s) received, and/or combined modality therapy with chest radiotherapy. Both specialists should collaborate in order to minimize the impact of these two ubiquitous diseases (cancer and CVD) and mitigate the adverse effects of treatment modalities.  相似文献   

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