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   217篇
  免费   15篇
  国内免费   28篇
耳鼻咽喉   8篇
儿科学   9篇
妇产科学   16篇
基础医学   23篇
口腔科学   5篇
临床医学   36篇
内科学   31篇
皮肤病学   7篇
神经病学   3篇
特种医学   15篇
外科学   41篇
综合类   8篇
预防医学   7篇
眼科学   4篇
药学   37篇
中国医学   1篇
肿瘤学   9篇
  2022年   1篇
  2021年   5篇
  2020年   2篇
  2019年   3篇
  2018年   7篇
  2016年   4篇
  2015年   9篇
  2014年   9篇
  2013年   14篇
  2012年   8篇
  2011年   5篇
  2010年   10篇
  2009年   7篇
  2008年   8篇
  2007年   15篇
  2006年   12篇
  2005年   8篇
  2004年   10篇
  2003年   6篇
  2002年   5篇
  2001年   8篇
  2000年   6篇
  1999年   11篇
  1998年   7篇
  1997年   18篇
  1996年   6篇
  1995年   5篇
  1994年   5篇
  1993年   4篇
  1992年   8篇
  1991年   5篇
  1990年   4篇
  1989年   9篇
  1987年   3篇
  1984年   1篇
  1983年   1篇
  1979年   3篇
  1978年   1篇
  1976年   1篇
  1975年   1篇
  1971年   1篇
  1965年   1篇
  1961年   2篇
  1959年   1篇
排序方式: 共有260条查询结果,搜索用时 15 毫秒
1.
2.
Croup is an acute infectious illness usually occurring in children; it is characterized by brassy cough and stridor. The main pathogens include mainly parainfluenza and influenza viruses. Recently there have been reports of prolonged croup caused by the herpes simplex viruses. We report two cases of prolonged croup due to herpes simplex types 1 and 2. We also review and summarize the reported pediatric cases of herpetic croup.  相似文献   
3.
Primitive Neuroectodermal Tumors of the Central Nervous System   总被引:2,自引:0,他引:2  
Controversial issues relating to the pathobiology and classification of central nervous system primitive neuroectodermal tumors (PNETs) have plagued neuropathologists for more than 70 years. Hypotheses advanced in the mid-1920's have remained as fixed concepts in contemporary literature, largely consequent to repetitious support by a small number of neuropathologists despite a growing body of information discrediting these ideas from neuroembryologists, oncologists, neuroscien-tists and pathologists.
Attention has largely focused upon PNETs arising in the cerebellum (commonly known as medul-loblastomas [MBs]), because about 80% of central nervous system (CNS) PNETs originate in this site. It has been asserted that the 20% which do not are biologically different, although most individuals agree that the histological features of PNETs that occur in different sites throughout the CNS are indistinguishable from those growing in the cerebellum.
The historical aspects of this controversy are examined in the face of evidence that there is, in fact, a unique class of CNS tumors which should appropriately be regarded as primitive neuroectodermal in nature. Specifically, a number of different approaches to the problem have yielded data supporting this hypothesis. These approaches include the identification of patterns of expression among a variety of cellular antigens (demonstrated by the use of immunopathological techniques), molecular analyses of cell lines derived from these tumors, experimental production of PNETs and molecular genetic analyses.
Differences of opinion among surgeons, oncologists and radiotherapists are typically resolved by conducting cooperative studies of patients with these tumors who are diagnosed and treated at multiple centers.  相似文献   
4.
Cortical auditory evoked potentials (N1 wave) were studied in 24 adults (12 men, 12 women) and 20 children (12 boys, 8 girls; age: 4-8 years). In adults, this wave was recorded with maximal amplitude at frontocentral sites, peaking at about 100 ms poststimulation, whereas in children the auditory response displayed maximal amplitude at the midtemporal sites, with a positive wave at about 100 ms and a large negative wave at approximately 170 ms. Moreover, the modulatory effects of intensity on N1 amplitude were prominent at frontocentral sites in adults and at temporal sites in children. Frontocentral negative response was also recorded in children but was smaller in amplitude and longer in peak latency (around 140 ms) than in adults; responses were of greater amplitude at the frontal site than at the vertex before 6 years of age, whereas the reverse was more often found after this age. These data suggest great differences with age in the neural generators contributing to auditory evoked potentials recorded in the N1 latency range.  相似文献   
5.
The objective of the study was to evaluate liquid cranberry products as prophylaxis against bacterial urinary tract infection in a pediatric neuropathic bladder population. Forty cases managed by clean intermittent catheterization with or without pharmacotherapy were enrolled in a randomized single-blind cross-over study. Subjects ingested 15 mL/kg/day of cranberry cocktail or water for six months followed by the reverse for another six months. Initial catheter urine samples and subsequent monthly and interim cultures were obtained. Associated symptoms were recorded along with follow-up attendance/compliance registry. The number of negative culture months to the number of months contributed was tabulated and compared between interventions. Individual, cumulative and antimicrobial subset analysis was performed. Twenty one patients completed the study;12 dropped out for reasons related to the cranberry (taste, caloric load and cost); seven patients dropped out for other reasons (parents too busy, death, no stated reason). Wilcoxon matched-pairs Signed-ranks analysis revealed no difference between intervention periods (2-tailed P=.5566 [whole group]; p=.2845 [antimicrobial subset]) with respect to infection. Fewer infections were observed in nine patients taking cranberry juice and in nine patients given water; no difference was noted in three. Liquid cranberry products, on a daily basis, at the dosage employed, did not have any effect greater than that of water in preventing urinary tract infections in this pediatric neuropathic bladder population.  相似文献   
6.

Purpose

We attempted to determine how patients with an orthotopic bladder perceive the desire to void and the force achieved to evacuate the bladder.

Materials and Methods

A total of 24 men who had undergone post-cystectomy bladder substitution (ileocecal in 12, sigmoid in 6 and ileal in 6) was evaluated subjectively and objectively by pressure-flow study 1 to 3 years postoperatively.

Results

Desire to void was felt at the base of the penis or in the perineum by 20 men (83 percent). Abdominal pressure contributed to intra-reservoir pressure by 51 to 54 percent in ileocecal, 20 to 24 percent in sigmoid and 23 to 25 percent in ileal neobladders.

Conclusions

Patients perceive the desire to void when drops of urine leak into the proximal urethra from an overfilled neobladder. Urine is evacuated mainly by abdominal straining for ileal neobladders, mainly by contraction for sigmoid neobladders, and by approximately equal contributions of contraction and straining for ileocecal neobladders.  相似文献   
7.
Objectives: A prospective study comparing the efficiacy and side-effects of oral sulindac with intravenous indomethacin in clinically stable preterm infants (<1750 g) requiring non-invasive closure of haemodynamically significant patent ductus arteriosus.
Methodology: As maturity and birthweight are the two major determinants of ductal closure, infants were matched as closely as possible for these parameters. An eligible patient was first assigned to the sulindac group and a subsequent patient with similar gestational age (± 1 week) and birthweight (±100 g) to the previously recruited infant would automatically receive indomethacin. A total of eight infants were enrolled in each group.
Results: The ductus arteriosus was successfully closed in all eight infants receiving indomethacin, and in seven of eight infants receiving sulindac. No significant differences were found with regards to the ductal size between the two groups at diagnosis or on each of the consecutive days of treatment ( P >0.25). More renal adverse effects were encountered in the indomethacin group. Significant differences in changes from baseline value for urine output, plasma sodium, urea and creatinine concentrations were noted at 24, 48 and 72 h after commencement of treatment between the two groups ( P <0.05). All the parameters returned to normal or pre-treatment levels 48 h after stopping therapy. Unexpectedly, severe gastrointestinal complications were encountered in the sulindac group.
Conclusions: Sulindac is capable of promoting ductal constriction in clinically stable preterm infants without compromising the renal function. The spectrum of gastrointestinal complications observed in sulindac treated infants were similar to those described for indomethacin. The use of sulindac for ductal closure in the preterm infant should remain experimental.  相似文献   
8.
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