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   867篇
  免费   36篇
  国内免费   5篇
耳鼻咽喉   25篇
儿科学   34篇
妇产科学   11篇
基础医学   101篇
口腔科学   35篇
临床医学   53篇
内科学   185篇
皮肤病学   6篇
神经病学   43篇
特种医学   17篇
外科学   150篇
综合类   16篇
预防医学   51篇
眼科学   37篇
药学   93篇
中国医学   5篇
肿瘤学   46篇
  2023年   10篇
  2022年   21篇
  2021年   29篇
  2020年   19篇
  2019年   14篇
  2018年   28篇
  2017年   11篇
  2016年   24篇
  2015年   29篇
  2014年   34篇
  2013年   42篇
  2012年   80篇
  2011年   72篇
  2010年   35篇
  2009年   40篇
  2008年   69篇
  2007年   69篇
  2006年   62篇
  2005年   46篇
  2004年   41篇
  2003年   31篇
  2002年   31篇
  2001年   16篇
  2000年   17篇
  1999年   8篇
  1998年   4篇
  1997年   2篇
  1995年   2篇
  1994年   1篇
  1992年   1篇
  1991年   3篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1985年   1篇
  1984年   3篇
  1979年   1篇
  1978年   1篇
  1976年   2篇
  1975年   1篇
  1974年   1篇
  1973年   2篇
  1972年   1篇
排序方式: 共有908条查询结果,搜索用时 15 毫秒
1.
2.
3.
Multiple antigenic peptides (MAPs) prepared for the predicted antigenic determinants on the VP2 protein of infectious bursal disease virus (IBDV) were used as antigens in enzyme-linked immunosorbent assay (ELISA)--an alternative to whole viral antigen to detect anti-IBDV antibodies in the chicken sera. Two MAPs were synthesized, which could specifically detect the anti-IBDV antibodies in serum samples by ELISA. The optimum quantity of MAP1 and MAP2 required to coat the wells of the ELISA plate was 5 ng/ml, whereas the amount of purified IBDV whole viral antigen was 500 ng/ml, indicating the high efficiency of MAPs. In this study, we mainly focused on the antigenicity of two eight-branched MAPs to detect anti-IBDV antibodies in ELISA, which would serve as safe, chemically defined, noninfectious alternative antigens to whole virus in serodiagnosis. The specificity and sensitivity of both MAP1 and MAP2 were found to be relatively better than the whole viral antigen.  相似文献   
4.
The walls of the third ventricle have been proposed to serve as a bidirectional conduit for exchanges between the neural parenchyma and the cerebrospinal fluid. In immunohistochemical studies of mice, we observed that light exposure and circadian phase affected peptide staining surrounding the third ventricle at the level of the suprachiasmatic nuclei. Under high magnification, we observed robust staining for the neurohormone oxytocin and the calcium-binding protein parvalbumin associated with cilia extending into the third ventricle from the surrounding ventricular wall; no similar staining was observed for vasopressin or calbindin. Retinal illumination had opposite effects on levels of parvalbumin and oxytocin in the cilia: light exposure during late subjective night increased oxytocin staining, but decreased parvalbumin staining in the cilia. Preventing cellular transport with colchicine eliminated immunohistochemical staining for oxytocin in the cilia. There was also a significant daily rhythm of oxytocin immunostaining in the third ventricle wall, and in magnocellular neurons in the anterior hypothalamus. The results suggest that environmental lighting and circadian rhythms regulate levels of oxytocin in the cerebrospinal fluid, possibly by regulating movement of oxytocin through the third ventricle wall.  相似文献   
5.

Background  

This study was undertaken to investigation the effect of Diasulin, a poly herbal drug composed of ethanolic extract of ten medicinal plants on blood glucose, plasma insulin, tissue lipid profile, and lipidperoxidation in alloxan induced diabetes.  相似文献   
6.
Health Care Management Science - An important challenge confronting healthcare is the effective management of access to primary care. Appointment scheduling policies/templates can help strike an...  相似文献   
7.
The electroconvulsive therapy (ECT) guideline of the Royal College of Psychiatrists recommends a 0.5 mg/kg of succinylcholine for ECT modification. Our clinical experience suggests that this dose is insufficient for Indian patients. The dose recommended by the Royal College of Psychiatrists (0.5 mg/kg) and a larger dose (1 mg/kg) were compared in 50 patients referred for ECT. In one ECT session, patients were equally randomized to receive one of the two doses and in the next session they were switched to the other dose. The extent of motor seizure modification was rated on a five-point scale by two independent raters who were blinded to the succinylcholine dose. The interrater reliability was good (K = 0.85). "Poor" seizure modification occurred in 48% and 12% of patients with the 0.5 and 1 mg/kg doses, respectively. Of the 24 patients who had poor modification with 0.5 mg/kg, 20 had "good" modification in the session with 1 mg/kg (P < 0.001). A small delay (mean = 55 s) occurred in time to recover from the respiratory paralysis with the 1 mg/kg dose of succinylcholine. No patient, however, had prolonged apnea requiring special measures. We recommend 1 mg/kg of succinylcholine dose be used in the first ECT session. For subsequent sessions, the dose may be altered, depending on the response for optimal motor seizure modification. IMPLICATIONS: The dose of muscle relaxant (succinylcholine) recommended in modified electroconvulsive therapy is not based on empirical research. In the same patients (n = 50), two doses-0.5 mg/kg and 1 mg/kg-were compared during different electroconvulsive therapy sessions. The larger dose was more effective in modifying the peripheral convulsion.  相似文献   
8.
Formula methods of estimating seizure threshold in bilateral electroconvulsive therapy (ECT) have been successful in 75% (at the first ECT) and 80% (at the sixth ECT) of treatments (Gangadhar et al., 1998). This study showed the same results for unilateral (UL) ECT patients. Its aim was to compare formula and titration methods for threshold determination. The seizure threshold (dependent variable) was determined by the titration method used at the first ECT in consecutive consenting patients (n = 80) prescribed UL ECT under general anesthesia. The independent variables were age, gender, diagnosis, illness severity, concurrent drugs, head circumference, and inion-nasion distance. Forward, step-wise, linear regression analysis showed age as the only significant predictor of seizure threshold (15% of variance). A formula based on regression analysis was prospectively applied in an independent sample (n = 30) of patients receiving UL ECT using the titration method for threshold determination. The results calculated a higher threshold than the actual threshold used in 14 patients, a threshold level in 8 patients, and below threshold in 8 patients. Formula-based estimates would have been successful in 22 (73%) patients, but the majority of them would have received higher than the recommended stimulus dose. Titration is the method preferred for clinical use. However, if a patient's doctor wishes to use the formula-based method, he or she should do so with specific considerations.  相似文献   
9.
Dendrimers are branched molecules with well-defined lengths, shapes, molecular weights, and monodispersity in comparison to linear polymers. The dual effect of the chromophore luminescence and the morphology of the synthesized dendrimers has drawn a lot of interest towards the design of dendrimers with different chromophores. Furthermore, the stimulus-responsive systems can sequester drug molecules under a preset set of parameters and release them in a different environment in response to either an exogenous or endogenous stimulus. The addition of photoresponsive moieties to different dendrimer components, such as the core or branches, magnifies the importance of the dendrimer in several related sectors of nanotechnology, such as sensors, photoswitches, electronic gadgets, and drug delivery systems. This review article focused on photoresponsive/glycoside dendrimer structures and their biomaterial applications.

Dendrimers are branched molecules with well-defined lengths, shapes, molecular weights, and monodispersity in comparison to linear polymers.  相似文献   
10.
Purpose:To assess the retinal manifestations of Parkinson’s disease using optical coherence tomography.Methods:A prospective case-control study comparing 30 eyes from 15 patients with Parkinson’s disease and 22 eyes from 11 healthy age-matched controls. Total macular subfield thickness and the thickness of the ganglion cell layer, nerve fiber layer, and peripapillary retinal nerve fiber layer were measured with spectral-domain optical coherence tomography (SD-OCT).Results:The mean age of PD patients was 68.4 years ± 10.64 (range: 46–82) and in the control group was 66.36 ± 5.22 (range: 64–68). The average disease duration in patients with PD was 6.7 ± 2.8 years (range: 2–10 years). The mean best-corrected visual acuity in PD was 20/26 and 20/20 in controls, with P = 0.0059, which was significant. Significant difference was also found in the contrast sensitivity between both groups. Structural differences in the central macular thickness (P = 0.0001), subfield thicknesses in the superior (P = 0.003), inferior (P = 0.001), nasal (P = 0.004), and temporal subfields (P = 0.017) was seen. Severe thinning of the ganglion cell layer was seen in PD patients (P = 0.000) as well as of the nerve fiber layer (P = 0.004). Peripapillary retinal nerve fiber thickness measured showed significant thinning in superotemporal (P = 0.000), superonasal (P = 0.04), inferonasal (P = 0.000), inferotemporal (P = 0.000), nasal (P = 0.000), and temporal quadrants (P = 0.000).Conclusion:Visual dysfunction was observed in patients with PD along with structural alterations on OCT, which included macular volumes, ganglion cell layer, and peripapillary retinal nerve fiber layer.  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