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   514篇
  免费   22篇
  国内免费   1篇
耳鼻咽喉   4篇
儿科学   14篇
基础医学   100篇
口腔科学   7篇
临床医学   27篇
内科学   77篇
皮肤病学   13篇
神经病学   8篇
特种医学   56篇
外科学   46篇
综合类   8篇
预防医学   8篇
眼科学   100篇
药学   54篇
肿瘤学   15篇
  2022年   7篇
  2020年   4篇
  2018年   8篇
  2017年   11篇
  2016年   14篇
  2015年   11篇
  2014年   8篇
  2013年   6篇
  2012年   12篇
  2011年   13篇
  2010年   20篇
  2009年   16篇
  2008年   12篇
  2007年   21篇
  2006年   15篇
  2005年   14篇
  2004年   16篇
  2003年   12篇
  2002年   12篇
  2001年   9篇
  2000年   12篇
  1999年   4篇
  1998年   10篇
  1997年   9篇
  1996年   11篇
  1995年   6篇
  1994年   6篇
  1993年   4篇
  1992年   10篇
  1991年   11篇
  1990年   12篇
  1989年   23篇
  1988年   18篇
  1987年   17篇
  1986年   11篇
  1985年   7篇
  1984年   7篇
  1983年   8篇
  1982年   7篇
  1980年   4篇
  1979年   5篇
  1978年   9篇
  1976年   15篇
  1975年   11篇
  1974年   6篇
  1973年   5篇
  1969年   6篇
  1968年   6篇
  1967年   5篇
  1966年   6篇
排序方式: 共有537条查询结果,搜索用时 15 毫秒
531.
ObjectiveTo evaluate the safety of ethanolic seed extract of Eugenia jambolana (EJSE) using acute and sub-chronic toxicity assays in Swiss albino mice as per Organisation for Economic Co-operation and Development (OECD) guidelines.MethodsPossible behavioral changes and lethality were observed in mice administered a single dose [1 000, 2 000, 3 000, 4 000 or 5 000 mg/kg body weight (BW)] of EJSE. Plasma levels of metabolic, hepatic, cardiac and renal function markers, electrolytes, blood count and histopathology of major organs were monitored in mice chronically treated with EJSE (1 000, 2 000 or 3 000 mg/kg BW) for 28 days.ResultsSince no mortality was recorded in the acute toxicity evaluation up to a dose of 5 000 mg/kg bodyweight of EJSE, 50% lethal dose (LD50) was assumed to be > 5 000 mg/kg BW. In the sub-chronic toxicity evaluation, no adverse observations were recorded in mice administered with 2 000 mg/kg BW of EJSE; however at 3 000 mg/kg BW dose, moderately significant increase in the plasma levels of urea and creatinine was observed. Hence, the lowest observable adverse effect level (LOAEL) for EJSE was found to be 3 000 mg/kg BW and the no observable adverse effect level (NOAEL) was adjudged as 2 000 mg/kg BW.ConclusionsIt can be concluded from this study that, orally administered EJSE is safe up to a 10 fold higher dose than its reported therapeutic dose.  相似文献   
532.
We studied the effect of combined preparation on the basis of chitosan containing a bioregulator isolated from cattle serum in a concentration of 10(-10) mg/ml on healing of II-IIIa degree skin burns in mammals in vivo.  相似文献   
533.
We compared wound-healing activity of bioregulators isolated from cattle cornea, serum, and retinal pigment epithelium on in vivo model of experimental corneal injury in rabbits. Bioregulators were instilled into the eye as solutions at a concentration corresponding to 10-12 mg protein/ml. The animals were sacrificed on day 21 after injury and the corneas were examined histologically. The best wound-healing effect was produced by bioregulators isolated from the cornea and serum and instilled successively into rabbit eyes with an interval of 15-20 min twice a day: multicellular epithelium was observed in the wound, and slight inflammation, in the stroma.  相似文献   
534.
Experiments on stationary culture of posterior eye and roll-bottle culture of the whole eye from adult water lizards Pleurodeles waltl showed that sclera bioregulator produces a stabilizing effects on adhesion interactions between the sclera, choroid, and pigment epithelium and on the maintenance of viability of sclera fi broblasts and pigment epithelium cells.  相似文献   
535.
Host individuals not infested by parasites at a given time are either permanently free from parasites or could be infested at other times. We studied temporal variation in the presence or absence of fleas (Siphonaptera) on individual rodents of two species (Gerbillus dasyurus and Acomys cahirinus) and questioned if and how an individual rodent can change its infestation status temporally. Change in infestation status by fleas over time was found in 45.5% of G. dasyurus and 35.9% of A. cahirinus. In both host species, the proportion of individuals that either changed or did not change their infestation status did not differ from the null expectation of 1:1. No difference between the proportions of infested at two consecutive captures and uninfested at two consecutive captures animals was found in A. cahirinus, whereas the proportion of G. dasyurus infested by fleas at two consecutive captures was significantly greater than that of uninfested at two consecutive captures individuals. In both host species, similar proportions of individuals changed their infestation status either from being infested to being uninfested or vice versa. Among individuals of both species that were initially infested by fleas, similar proportions changed and did not change their subsequent infestation status. The same was true for the uninfested at the first capture A. cahirinus. However, among initially uninfested G. dasyurus, the proportion of individuals that remained uninfested was significantly greater than that of the individuals newly infested by fleas. In A. cahirinus, the probability to change the infestation status did not depend on the initial status of an individual. In G. dasyurus, the probability of the initially uninfested individuals to be subsequently found still uninfested was higher than to be subsequently found harboring fleas, whereas initially infested individuals could be subsequently found either still infested or flea-free with equal probability.  相似文献   
536.

Background and purpose:

Abnormal glutamatergic activity is implicated in neurologic and neuropsychiatric disorders. Selective glutamate receptor antagonists were highly effective in animal models of stroke and seizures but failed in further clinical development because of serious side effects, including an almost complete set of symptoms of schizophrenia. Therefore, the novel polyvalent glutamatergic agent 3,5-dibromo-L-phenylalanine (3,5-DBr-L-Phe) was studied in rat models of stroke, seizures and sensorimotor gating deficit.

Experimental approach:

3,5-DBr-L-Phe was administered intraperitoneally as three boluses after intracerebral injection of endothelin-1 (ET-1) adjacent to the middle cerebral artery to cause brain injury (a model of stroke). 3,5-DBr-L-Phe was also given as a single bolus prior to pentylenetetrazole (PTZ) injection to induce seizures or prior to the administration of the N-methyl-D-aspartate (NMDA) receptor antagonist dizocilpine (MK-801) to cause disruption of prepulse inhibition (PPI) of startle (sensorimotor gating deficit).

Key results:

Brain damage caused by ET-1 was reduced by 52%, which is comparable with the effects of MK-801 in this model as reported by others. 3,5-DBr-L-Phe significantly reduced seizures induced by PTZ without the significant effects on arterial blood pressure and heart rate normally caused by NMDA antagonists. 3,5-DBr-L-Phe prevented the disruption of PPI measured 3 days after the administration of ET-1. 3,5-DBr-L-Phe also eliminated sensorimotor gating deficit caused by MK-801.

Conclusion and implications:

The pharmacological profile of 3,5-DBr-L-Phe might be beneficial not only for developing a therapy for the neurological and cognitive symptoms of stroke and seizures but also for some neuropsychiatric disorders.  相似文献   
537.
【Objective】 To investigate effects of combined usage of dynamic neuro-electric stimulation(DNES) and M-cholynolytic therapy(oxybutynin) upon manifestations of neurogenic bladder dysfunctions(NBD) in children.【Method】 Urodynamics examination included registration of extemporaneous urinary excretion,urofluometry,and retrograde cytometry in horizontal and vertical position by example of urodynamic system(UDS) ACS 180 Plus(MENFIS BioMed.,USA).In accordance to severity of clinician manifestations,three groups of patients have been defined(27-highest one,49-middle and 51 low levels).Dynamic neuro-electrostimulation(DNES) procedures were conducted using the"DiaDNES-PKM"device(Russian Federation).The children were exposed to juxtaspinal stimulation on S1-S3 level-altogether 10 sessions have been performed.Oxybutynin(driptan) was used in dosage of 2.5 mg per diem.【Result】It was established that combined usage of DNES and oxybutynin in the group with highest severity caused the reduction of manifestations by 3.1 times while separately given DNES and basic therapy were followed by 34.1% and 28.0% reduction correspondently.Meanwhile,DNES and oxybutynin reduced severity in patients with pronounced disturbances by 7.5 times.Combined usage of oxybutynin and DNES in severely manifested NBD increased the effective volume of bladder by 2.3 times.Also significant reduction of both intrabladder pressure(by 48.0%) and compliance of the bladder(by 4.8 times) were detected under condition of combined usage of DNES and oxybutynin.All mentioned indices were modified to less extent in case of separate usage of DNES or oxybutynin when compared with the one registered after the combined their usage(P <0.05).【Conclusion】Combined usage of DENS and oxybutinin(driptan) is effective in most severe cases in children suffered from neurogenic overactive bladder.  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