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   9262篇
  免费   689篇
  国内免费   46篇
耳鼻咽喉   95篇
儿科学   275篇
妇产科学   220篇
基础医学   1373篇
口腔科学   332篇
临床医学   742篇
内科学   1658篇
皮肤病学   131篇
神经病学   928篇
特种医学   689篇
外科学   1355篇
综合类   69篇
一般理论   3篇
预防医学   585篇
眼科学   220篇
药学   645篇
中国医学   18篇
肿瘤学   659篇
  2023年   53篇
  2022年   125篇
  2021年   232篇
  2020年   165篇
  2019年   192篇
  2018年   204篇
  2017年   199篇
  2016年   240篇
  2015年   279篇
  2014年   343篇
  2013年   503篇
  2012年   647篇
  2011年   665篇
  2010年   392篇
  2009年   351篇
  2008年   573篇
  2007年   574篇
  2006年   503篇
  2005年   494篇
  2004年   421篇
  2003年   429篇
  2002年   396篇
  2001年   130篇
  2000年   117篇
  1999年   121篇
  1998年   100篇
  1997年   61篇
  1996年   82篇
  1995年   69篇
  1994年   58篇
  1993年   51篇
  1992年   83篇
  1991年   77篇
  1990年   73篇
  1989年   78篇
  1988年   67篇
  1987年   80篇
  1986年   60篇
  1985年   60篇
  1984年   63篇
  1983年   35篇
  1982年   34篇
  1981年   31篇
  1980年   36篇
  1979年   39篇
  1978年   29篇
  1977年   30篇
  1974年   35篇
  1973年   30篇
  1967年   23篇
排序方式: 共有9997条查询结果,搜索用时 15 毫秒
31.
32.
Objectives Even in the days of modern microsurgery, the removal of a brain stem lesion remains a surgical challenge. Especially when operating on children, the prognosis is directly related to the radicality of the resection; however, a radical resection is often associated with surgical morbidity. Intraoperative neuromonitoring could help to minimise the surgical morbidity, but few studies have been performed to clarify the value of this monitoring. We investigated a prospective series of 21 patients with lesions involving the brain stem for the prognostic value and benefits of neuromonitoring.Methods We performed intraoperative neuromonitoring of cranial nerve function by electromyography (EMG) and motor evoked potential (MEP). The results were correlated with postoperative neurological deficits.Conclusions There is a good correlation between intraoperative neurophysiological events and postoperative neurological deficits in patients with lesions of the brain stem. In general, transient, prolonged, spontaneous activity in EMG is associated with a transient paresis of the respective muscle, whereas a permanent spontaneous activity is associated with a permanent deficit. Intraoperative neuromonitoring reliably predicts postoperative neurological function in patients with tumours of the lower brain stem and fourth ventricle. This neuromonitoring guides the neurosurgeon in the operation and may decrease surgical morbidity. We recommend using monitoring of MEP and EMG of the lower cranial nerves in surgery on all patients with lesions involving the lower brain stem and fourth ventricle.  相似文献   
33.
Familial amyloidotic polyneuropathy (FAP) with a mutation in position 30 of transthyretin (TTR) (previously called prealbumin) is an autosomal dominant inherited disorder characterized by varying degrees of peripheral neuropathy, nephropathy, gastrointestinal problems, and vitreous amyloid. We have earlier diagnosed homozygosity for the TTR-Met30-gene using Southern analysis in four Swedish individuals. We have found it possible to detect homozygosity for the Met-30 mutation by amplifying discrete regions of the TTR-gene using polymerase chain reaction (PCR), and the amplification products restricted with NsiI analysed by gel electrophoresis. Clinical data on seven homozygous individuals, including three new cases, are presented.  相似文献   
34.
Is hyperreactivity the same as asthma?   总被引:1,自引:0,他引:1  
  相似文献   
35.
We reviewed our first 53 lengthenings performed in 45 patients with an average age of 19 years at the time of lengthening. The shortening was congenital in 16 patients, post-traumatic in 15 and had various causes in the 14 remaining. 31 femurs and 22 tibias with an average shortening of 6 and 5 cm, respectively, were lengthened 6 (2-14) cm. The aim was achieved in all but 4 patients, where lengthening had to be discontinued due to complications.

Potential complications of lengthening can be numerous but, if recognized, can in most cases be dealt with during the extended lengthening procedure. 38 cases of pin-tract infections healed with antibiotics. Restricted motion in one or more joints was registered in 49 cases during lengthening; minor restriction of joint motion persisted in 14 patients. 28 cases had angular deviations during lengthening. After additional surgery all but 10 could be corrected. 4 fractures occurred after removal of the external fixator. The total number of complications was 146, and of these 76 were minor, 42 moderate and 28 severe. 36 of the 42 patients available to follow-up were satisfied with the results of the lengthening procedure.  相似文献   
36.
The possible occurrence of benzodiazepine-like substances in human breast milk was investigated in 35 healthy, newly delivered women who were known not to be taking benzodiazepines. Maternal blood samples and a sample of breast milk were obtained on the fifth post partum day. A radioreceptor technique (lower limit of detection 1.5 ng/ml; difference between duplicates at various concentrations <7%) was used for measuring benzodiazepine-like substances in blood and breast milk (with and without prior extraction). No benzodiazepine-like substances could be demonstrated in any of the blood samples taken from the 35 women. Measurable concentrations of benzodiazepine-like substances were demonstrated in all but 1 of the 35 breast milk samples. The mean concentration of benzodiazepine-like substances for all 35 women was 4.3±2.3 ng/ml (range 0–9.3 ng/ml) expressed as lorazepam. The corresponding value for extracted breast milk was 2.6±1.5 ng/ml (range 0–7.0 ng/ml). There was no association between concentrations of benzodiazepine-like substances in breast milk and maternal age, weight, height and body mass or parity, or the sex of the infant and infant birth weight. We suggest that non-detectable amounts of benzodiazepine-like substances in serum are concentrated in the mammillary glands and excreted in a higher concentration in breast milk. It is less likely that the relevant benzodiazepines are produced in the mammillary glands.  相似文献   
37.
In order to study clinicopathologic features of hepatocellular carcinoma (HCC) and their relation to metastatic growth, all autopsied cases with confirmed HCC (n = 490) from a period with a high autopsy frequency in a well-defined population were analyzed. Cirrhosis, usually of micronodular type, was found in 72%. The gross appearance of the tumour was predominantly massive (46%) or multinodular (42%). The tumour involved both liver lobes in 72% or the right lobe alone in 20%. Histologically, trabecular growth (79%) and grade II of differentiation (52%) prevailed. Vascular invasion was noted in 56%, whereas involvement of the biliary tract was unusual (4%). Metastases especially involved lymph nodes (42%), lungs (18%) and skeleton (17%). Increased weight of the liver, multinodular appearance, involvement of both liver lobes, low grade of differentiation and vascular invasion were significantly associated with presence of metastases.  相似文献   
38.
39.
Urologists remain divided as to the need for routine irrigation following transurethral prostatectomy (TURP). This randomised prospective study compared a policy of irrigation with that of no irrigation in a consecutive group of 200 patients undergoing TURP. In the irrigation group, a mean of 15 litres of irrigating fluid was used in each patient and one-third of patients required at least one bladder washout. In the no irrigation group, although two-thirds of the patients required at least one bladder washout, only one-third required more than one washout. No significant difference in blood loss, electrolyte balance, infection rate or recovery was seen in the 2 groups. This study led to a local change in practice, converting from a policy of routine irrigation to one of no irrigation.  相似文献   
40.
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