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   785篇
  免费   77篇
  国内免费   5篇
耳鼻咽喉   21篇
儿科学   118篇
妇产科学   7篇
基础医学   68篇
口腔科学   76篇
临床医学   78篇
内科学   124篇
皮肤病学   20篇
神经病学   45篇
特种医学   97篇
外科学   88篇
综合类   24篇
预防医学   18篇
眼科学   4篇
药学   47篇
肿瘤学   32篇
  2022年   7篇
  2021年   3篇
  2020年   6篇
  2019年   9篇
  2018年   10篇
  2017年   8篇
  2016年   10篇
  2015年   18篇
  2014年   19篇
  2013年   23篇
  2012年   23篇
  2011年   23篇
  2010年   44篇
  2009年   37篇
  2008年   31篇
  2007年   32篇
  2006年   35篇
  2005年   22篇
  2004年   21篇
  2003年   24篇
  2002年   27篇
  2001年   21篇
  2000年   29篇
  1999年   19篇
  1998年   36篇
  1997年   36篇
  1996年   36篇
  1995年   32篇
  1994年   24篇
  1993年   24篇
  1992年   12篇
  1991年   16篇
  1990年   7篇
  1989年   16篇
  1988年   15篇
  1987年   18篇
  1986年   12篇
  1985年   11篇
  1984年   7篇
  1983年   6篇
  1982年   8篇
  1981年   13篇
  1980年   5篇
  1979年   4篇
  1978年   2篇
  1977年   8篇
  1976年   6篇
  1941年   1篇
  1939年   1篇
  1931年   1篇
排序方式: 共有867条查询结果,搜索用时 15 毫秒
51.

Background  

Chronic lymphocytic leukemia (CLL) is a monoclonal disorder, characterized by a progressive proliferation of functionally incompetent B lymphocytes. There is increased evidence of association between CLL and skin cancers, including the uncommon Merkel cell carcinoma (MCC).  相似文献   
52.
This report describes the use of a naloxone infusion at a rate of 300 micrograms/h to provide constant antagonism of the respiratory depressant effects of a near fatal nor-methadone dose in a 2 year old boy. The terminal half-life for nor-methadone was calculated to be 13.5 h. The results indicate that a single dose of a narcotic antagonist with a short half-life (e.g. naloxone) will probably be inadequate to provide long lasting reversal of the effects of overdoses of long half-life narcotic agonists, and that continuous infusion may be the preferable to repeated bolus doses.  相似文献   
53.
Moderate antenatal renal pelvic dilation (5-15 mm) may suggest vesicoureteric reflux, but it is not known to predict renal scarring. Dimercaptosuccinic acid scans on such children aged over 4 years showed a scarring rate (0/133 boys, 1/56 girls) similar to our local population. Investigation and treatment of moderate dilation may not be required.  相似文献   
54.
55.
The current practice of dosing patients with anticancer drugs based on body size, leads to a large degree of inter-patient variation in clinical outcome following standard doses of chemotherapy. Some patients may fail to respond to treatment, whilst others experience unacceptable side effects. Recent studies have identified more rational approaches to drug dosing, based on patient characteristics such as renal function, pharmacogenetic factors, and drug metabolizing activity. These can be used together with therapeutic drug monitoring and adaptive dosing to achieve a targeted systemic drug exposure in each patient, which may lead to more consistent clinical outcomes in patients receiving comparable chemotherapy dosing regimens. The purpose of this review is to present some approaches to chemotherapy individualization, examples of how this might be applied, and speculation as to how recent advances in pharmacogenetics may lead to further dose-optimization.Whilst it is hoped that the design of new agents, targeted to specific genes involved in oncogenesis, will lead to increased success in the treatment of cancer patients, it is essential that the drugs currently available are used to their maximum potential.  相似文献   
56.
The Eph family of receptor tyrosine kinases plays a crucial role during development and is implicated in oncogenesis. Using a partial cDNA clone of an Eph-related kinase (Esk) we isolated the complete coding region of a gene which we show to be murine EphA1 by both structural and functional criteria. The chromosomal localization is shown to be syntenic to hEphA1 and the genomic organization also shows distinct features found in the hEphA1 gene. Functionally, in keeping with findings for the human homologue, both soluble recombinant and "native" mEphA1 show preferential binding to ephrin A1. However, we also observed significant binding to other A-type ligands as has been observed for other Eph receptors. We analysed the expression of mEphA1 mRNA by in situ hybridization on tissue sections. mEphA1 was expressed in epithelial elements of skin, adult thymus, kidney and adrenal cortex. Taken together with previous Northern blotting data these results suggest that mEphA1 is expressed widely in differentiated epithelial cells.  相似文献   
57.
Objective: Liquid oral medicines form a significant proportion (11%) of the medicines used by the population as a whole, either prescribed or over the counter. The active agent, as well as some of the other ingredients, can pose a threat to oral health. Method: Eight liquid oral medicines and two effervescent preparations routinely prescribed for longterm use by paediatric renal patients were assessed for titratable acidity and pH values. Results: All of the medicines tested were acidic and the majority were well below the critical pH of 5.5 at which enamel demineralisation takes place. The titratable acidity values, at a pH of 6.7, ranged between 0.01 and 1.54 for the liquid preparations but were 8.4 and 10.6 for the two effervescent tablets tested. Conclusion: Surplus acid in effervescent preparations while ensuring palatability of medicines and thus compliance, may produce unwanted dental side effects in children who are already medically compromised.  相似文献   
58.
Securinega virosa is used traditionally as sedative in children and in mental illnesses. In this study, the behavioral effects of methanolic root bark extract of S. virosa were investigated in mice. The results revealed that the extract significantly (P<0.05) and dose-dependently reduced the onset and prolonged the duration of sleep. The extract significantly (P<0.05) decreased exploratory activity and reduced the rate of apomorphine-induced stereotyped climbing at the doses tested (6.25–25mg/kg). It also produced a significant and dose-dependent motor coordination deficit in mice at the doses tested (P<0.01). The intraperitoneal median lethal dose in mice was 774.6mg/kg while the preliminary phytochemical screening revealed the presence of alkaloids, tannins, saponins and flavonoids. These results suggest that methanolic root bark extract of S. virosa contains biologically active principles that are sedative in nature and lend pharmacological credence to the ethnomedical use of the plant.  相似文献   
59.
60.
Several studies have shown the benefit of withdrawal therapy when medication overuse headache (MOH) is suspected. Our aim was to compare the effect of withdrawal therapy in patients followed by a neurologist (group A, n  = 42) and a primary care physician (PCP) (group B, n  = 38). Patients were randomized to A or B, and follow-up was at 3, 6 and 12 months. Calculated mean headache (MH at 6 months + MH at 12 months)/2 (primary end-point) was similar; A 1.04 (0.87, 1.21) and B 1.02 (0.82, 1.21) ( P  = 0.87). The number of patients with 50% improvement of headache days was also similar; 14/42 in group A vs. 12/34 in B ( P  = 0.86) at 3 months, 15/42 vs. 11/33 ( P  = 0.83) at 6 months and 15/42 vs. 14/38 ( P  = 0.92) at 12 months. Days without headache during the last 9 months of follow-up were 123 (96, 150) in group A and 137 (112, 161) in B ( P  = 0.62). After 3 months one-third were classified as MOH. Patients with MOH improved similarly in group A and B, and so did patients without MOH. Within 1 year 7/42 in A and 9/38 in B had recurrent medication overuse ( P  = 0.43). In summary, there were no significant differences in follow-up results between the two groups.  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