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   820篇
  免费   56篇
  国内免费   3篇
耳鼻咽喉   3篇
儿科学   32篇
妇产科学   9篇
基础医学   114篇
口腔科学   17篇
临床医学   112篇
内科学   171篇
皮肤病学   11篇
神经病学   34篇
特种医学   17篇
外科学   84篇
综合类   24篇
预防医学   63篇
眼科学   40篇
药学   95篇
中国医学   7篇
肿瘤学   46篇
  2023年   10篇
  2022年   20篇
  2021年   52篇
  2020年   20篇
  2019年   29篇
  2018年   34篇
  2017年   23篇
  2016年   22篇
  2015年   49篇
  2014年   26篇
  2013年   44篇
  2012年   46篇
  2011年   48篇
  2010年   32篇
  2009年   21篇
  2008年   26篇
  2007年   53篇
  2006年   40篇
  2005年   36篇
  2004年   56篇
  2003年   35篇
  2002年   33篇
  2001年   8篇
  2000年   8篇
  1999年   4篇
  1996年   3篇
  1995年   2篇
  1994年   4篇
  1993年   2篇
  1992年   8篇
  1991年   6篇
  1990年   3篇
  1989年   5篇
  1988年   5篇
  1987年   2篇
  1984年   4篇
  1983年   4篇
  1979年   5篇
  1978年   5篇
  1977年   2篇
  1976年   4篇
  1975年   4篇
  1974年   4篇
  1973年   3篇
  1971年   2篇
  1968年   3篇
  1967年   5篇
  1944年   2篇
  1934年   2篇
  1933年   1篇
排序方式: 共有879条查询结果,搜索用时 15 毫秒
1.
2.
C-reactive protein levels predict postoperative septic complications   总被引:5,自引:0,他引:5  
We studied 108 patients undergoing clean-contaminated and dirty surgical procedures to determine whether daily C-reactive protein (CRP) measurements for 14 days postoperatively could predict the occurrence of septic complications prior to clinical diagnosis. Diagnostic criteria for septic complications and positive CRP response were defined in advance of the study. The CRP assays were carried out using an automated laser nephelometer system after the patient's discharge from the hospital. Forty-six septic complications were diagnosed in 40 patients. These complications consisted of wound infection (23), urinary tract infection (11), pneumonia (six), upper respiratory tract infection (three), intra-abdominal abscess (one), and other (two). The CRP testing was found to have a positive predictive value of 69% and a negative predictive value of 78%. We conclude that serial CRP measurements may be a valuable adjunct to surgical care in patients at high risk of postoperative septic complications.  相似文献   
3.
Dimethyl isosorbide (DMI), which is currently under investigation for its potential use as a pharmaceutical vehicle and drug permeation enhancer, is a water-miscible liquid with relatively low viscosity. The solubilization behavior of DMI as a cosolvent for nonpolar drugs was characterized via dielectric constant measurements of binary solvent systems containing DMI and either water, propylene glycol (PG), or polyethylene glycol (PEG). Evidence from the dielectric constant profiles and NMR studies suggest that DMI undergoes complexation with water and PG, but not with PEG, through hydrogen bonding interactions. The solvent complexation exhibited a major effect on the solubilities of prednisone, dexamethasone, and prednisolone in the mixed solvent systems. Maximum solubility of each drug was found to occur near a DMI/water or DMI/PG concentration ratio of 1:2. In the DMI–PEG mixed system, while there is no apparent interaction between DMI and PEG molecules, the solubility of prednisone was found to increase with decreasing dielectric constant.  相似文献   
4.
Microspheres of 5-fluorouracil have been prepared, using three grades of ethyl cellulose as wall forming materials, and utilizing a solvent evaporation technique under ambient conditions. An alcoholic solution of 5-fluorouracil and polymer was dispersed in liquid paraffin containing 33.3 per cent n-heptane. The effect of stirring rate, time of stirring, drug loading, and polymer grade on drug release in two different media were evaluated. The drug loaded particles were spherical in shape and had a diameter range of 25-200 mm and were suitable for incorporating into a gel base. Drug release studies in aqueous media, showed that acidic media provide a faster release rate than neutral media. The drug release study from an aqueous gel base preparation at pH 7.0 through a synthetic membrane was found to be promising for formulation of a gel-microsphere product for the treatment of skin lesions.  相似文献   
5.
An in vivo study was undertaken during hypothermic (28 degrees C) cardiopulmonary bypass to compare oxygenator exhaust capnography as a means of estimating arterial carbon dioxide tension (PaCO2) with bench blood gas analysis. A total of 123 pairs of measurements were made in 40 patients. Oxygenator exhaust capnographic measurements systematically underestimated PaCO2 measured by a bench blood gas analyzer. During the cooling and stable hypothermic phases of cardiopulmonary bypass, the relationship was reasonably accurate, but became far more variable during rewarming. Oxygenator exhaust capnography could be used as an inexpensive means of continuously monitoring PaCO2 during the cooling and stable hypothermic phases of cardiopulmonary bypass but should not be used during rewarming.  相似文献   
6.
7.
The role of a transmembrane protein, integrin alpha2beta1, to modulate the neural responses of cutaneous mechanoreceptors to mechanical indentation was examined using an isolated skin-nerve preparation in a rat model. Skin and its intact innervation were harvested from the medial thigh of the hindlimb and placed in a dish containing synthetic interstitial fluid. Using a standard teased nerve preparation, the neural responses of single slowly or rapidly adapting mechanoreceptors (SA or RA, respectively) were identified and the afferents categorized according to standard protocols (i.e. response to constant stimuli). The most sensitive spot of a mechanoreceptor's receptive field was identified and then stimulated using controlled compressive stress (constant or dynamic loads between threshold and saturation load for SAs and RAs, respectively). Loads were applied before, during, and after passive diffusion into the skin of a function-blocking anti-integrin alpha2 monoclonal antibody (FBmAb) or one of two types of control antibodies (immunoglobulin G or a FBmAb conjugated with a secondary antibody). The sensitivities of both SA and RA mechanoreceptors were profoundly reduced in the presence of the FBmAb, while not changing the waveforms of their action potentials or their adaptation properties. Both control antibodies had no significant effect on mechanoreceptors' sensitivities. Following removal of the FBmAb, the effects in some neurons were partially reversible. Taken together, the data from this study support the hypothesis that integrin alpha2beta1 plays a significant role in modulating mechanoreceptive response to compressive indentation.  相似文献   
8.
ABSTRACT

Many ingredients in cosmetic products help to develop complex formulations that improve the quality of life in terms of disease prevention, health maintenance, beauty enhancement, and building self-esteem. The beneficial effects promoted from the use of biomolecule-rich substances into the formulations of various topical application products are considered useful ingredients in cosmetic and therapeutic applications. This review article attempts to understand the various biomolecules found in cosmetic products, particularly macromolecules, which may have an important role in prevention or preservation. Increasing demand of cosmetics all over the world has increased the awareness related to safety issue. Cosmetic products may contain potential contact allergens or precursors that can be oxidized or metabolized to generate contact allergens which can potentially cause allergic reactions or dermatitis. These substances can pose hazards to human health due to their ability to activate T cells that can cause allergic contact dermatitis, an inflammatory skin disease. Finally, the simultaneous on-site measurement of different substances from a single sample, called multiplexed point-of-care testing, has recently become increasingly important for the in vitro quantification of pathological or toxicological samples. Hence, the technological advancements in clinical sciences will be helpful in the identification of ingredients in cosmetic preparations.  相似文献   
9.
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