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   354篇
  免费   18篇
  国内免费   13篇
儿科学   34篇
妇产科学   6篇
基础医学   43篇
口腔科学   12篇
临床医学   34篇
内科学   57篇
皮肤病学   7篇
神经病学   21篇
特种医学   93篇
外科学   9篇
综合类   4篇
预防医学   19篇
眼科学   10篇
药学   16篇
肿瘤学   20篇
  2022年   2篇
  2021年   4篇
  2020年   1篇
  2019年   2篇
  2018年   4篇
  2017年   4篇
  2016年   4篇
  2015年   14篇
  2014年   5篇
  2013年   9篇
  2012年   10篇
  2011年   2篇
  2010年   15篇
  2009年   10篇
  2008年   5篇
  2007年   14篇
  2006年   6篇
  2005年   5篇
  2004年   8篇
  2003年   6篇
  2002年   11篇
  2001年   6篇
  2000年   18篇
  1999年   3篇
  1998年   26篇
  1997年   39篇
  1996年   28篇
  1995年   18篇
  1994年   14篇
  1993年   6篇
  1992年   4篇
  1991年   1篇
  1990年   5篇
  1989年   11篇
  1988年   11篇
  1987年   1篇
  1986年   5篇
  1985年   6篇
  1984年   2篇
  1983年   10篇
  1982年   5篇
  1981年   3篇
  1980年   5篇
  1978年   2篇
  1977年   7篇
  1976年   4篇
  1975年   3篇
  1973年   1篇
排序方式: 共有385条查询结果,搜索用时 15 毫秒
81.
82.
Small bowel carcinoid tumours are endocrine tumours of the gastrointestinal tract. This pictorial essay will review the pathology, clinical features, treatment and prognosis and illustrate the radiographic, computed tomographic, sonographic, magnetic resonance and nuclear medicine appearances of small bowel carcinoid tumours.  相似文献   
83.
84.
云南甘草中新三萜成分的研究   总被引:9,自引:0,他引:9  
自云南甘草(Clycyrrhiza yunnanensis)根中分离出10个化合物,经化学方法和光谱解析,鉴定9个为五环三萜类化合物:3β,21α,24-三羟基-齐墩果-12-烯-29-羧酸(Ⅰ)、3β,21α-二羟基-齐墩果-12-烯(Ⅱ)、3β,21α,24-三羟基-齐墩果-12-烯(Ⅲ)、桦木酸(Ⅳ)、23-羟基桦木酸(Ⅴ)、齐墩果酸(Ⅵ)、3β-羟基-16-氧-11,13(18)-二烯-3O-羧酸(Ⅶ)、24-羟基甘草内酯(Ⅷ)和21α-乙酰氧基木栓烷-3-酮(Ⅸ);另一个为β-胡萝卜甙(Ⅹ)。其中Ⅰ和Ⅱ为新化合物,分别命名为云南甘草皂甙元B1和B2。其余7个是已知物,但Ⅴ和Ⅸ首次得自甘草属植物,Ⅳ,Ⅵ和Ⅷ首次自云南甘草中分离得到。  相似文献   
85.
We describe a rare case of familial Cushing's disease occurring in a 7-year-old boy, and 19 years of follow up. Our patient first presented soon after his maternal aunt had been treated for Cushing's disease. The clinical presentation was made complicated by the development of an intercurrent eating disorder resembling anorexia nervosa. This resulted in marked weight loss, and even though serum and urinary cortisol levels were elevated, many of the clinical stigmata of Cushing's disease were absent. Eating disorders are relatively uncommon in boys, and in this case there was an organic cause for the abnormal behaviour. This case shows, furthermore, that even the obesity of Cushing's disease can be overcome by the combination of diet and exercise.  相似文献   
86.
From 170 pregnant women, cervico-vaginal secretion, serum and amnion fluid were collected to determine concentrations of herpes simplex virus (HSV) IgA in different risk groups. We found a higher concentration of HSV IgA in cervicovaginal secretions in women with positive cultures, compared with women with negative cultures. Women with a prior history of genital HSV infections also had higher levels of HSV-IgA in cervico-vaginal secretions, compared with those with no HSV history, but the differences were not statistically significant. The concentrations of HSV IgA in cervico-vaginal secretions were not correlated to any other risk group defined in the study. An asymptomatic mother with no previous history of genital HSV infection, but belonging to the risk groups gave birth to an infant who developed neonatal herpes on the 4th day of life. Women at risk for viral shedding during gestation and at the time of delivery cannot be identified solely on the basis of grouping into risk groups and/or on concentration of HSV IgA in cervico-vaginal secretion.  相似文献   
87.
88.
BACKGROUND: The treatment with XeCl-excimer laser generated 308-nm UVB radiation has shown promising results in patients with vitiligo. OBJECTIVE: In this controlled, prospective trial we studied the primary efficacy (start and grade of repigmentation) and patient's satisfaction of XeCl-excimer laser for treatment of vitiligo patches at different body sites and re-evaluated the achieved repigmentation 12 months after the end of therapy. METHODS: Twenty-five patients with generalized or localized vitiligo with a total of 85 lesions at different body sites were enrolled in this study. Vitiligo patches were treated with 308-nm XeCl-excimer laser 3 times a week for 6 to 10 weeks. The overall repigmentation grade of each treated lesion was evaluated once a week on a 5 point scale rating from 0 (no repigmentation), 1 (1-5%), 2 (6-25%), 3 (26-50%), 4 (51-75%), to 5 (76-100%). RESULTS: Twenty-four patients completed the study. Within 6 to 10 weeks of treatment 67% of the patients (16/24) developed follicular repigmentation of at least one of their vitiligo lesions. Lesion repigmentation started after a mean of 13 treatments in lesions located on the face, trunk, arm, and/or leg (high-responder location), and after a mean of 22 treatments in lesions located on the elbow, wrist, dorsum of the hand, knee, and/or dorsum of the foot (low-responder location). Untreated control lesions and lesions located on the fingers did not achieve any repigmentation. After 10 weeks of treatment repigmentation of more than 75% was found in 25% (7/28) of lesions of the high-responder location group versus 2% (1/43) of lesions of the low-responder location group. In most cases, laser-induced repigmentation was persistent, as determined 12 months after the end of treatment. CONCLUSIONS: 308-nm excimer laser is an effective modality for the treatment of vitiligo. However, similar to other non-surgical treatment modalities, the therapeutic effect is mainly dependent on the location of vitiligo lesions.  相似文献   
89.
In a distinct autosomal recessive variant of epidermolysis bullosa, EB- MD, life-long skin blistering is associated with late-onset muscular dystrophy of unknown etiology. Electron microscopy of these patients' skin suggests that tissue separation occurs intracellularly at the level of the hemidesmosomal inner plaque, which contains plectin, a high molecular weight cytoskeletal associated protein, also expressed in the sarcolemma of the muscle. In this study, we report two patients with EB-MD, each with a homozygous deletion mutation in the plectin gene, PLEC1. In the first case, the proband and her similarly affected sister had a homozygous 9 bp deletion mutation, designated as 2719de19, which resulted in elimination of three amino acids, QEA, in a sequence of 23 amino acids entirely conserved between the mouse and human sequences. The proband in the second family demonstrated a single nucleotide deletion at position 5866, designated as 5866delC, which resulted in frameshift and a premature termination codon for translation 16 bp downstream from the site of deletion. The absence of plectin in the hemidesmosomes, as reflected by negative immunofluorescence with an anti-plectin antibody (HD-1), associated with fragility of basal keratinocytes, implicates plectin as critical for binding of intermediate keratin filament network to hemidesmosomal complexes. The function of plectin as a putative attachment protein also in the muscle would explain the clinical phenotype consisting of cutaneous fragility and muscular dystrophy in EB-MD.   相似文献   
90.
The polymerase chain reaction (PCR) technique has become an important, widely employed method for the detection and quantitation of the nucleic acid sequences used in the diagnosis and monitoring of genetic and infectious diseases. Much attention has been directed at the problem of false-positive PCR results, which are generally attributed to low-level laboratory contamination of amplified sequences ("carryover"). In contrast, few investigators have commented on the somewhat less frequent, but equally problematic, false-negative PCR results. Investigation of the source of sporadic false-negative PCR reactions found that glove powder, inadvertently introduced into tubes when gloves are changed in an effort to reduce false-positive results, can nonspecifically inhibit each of the major steps in the PCR detection process. Methodologic precautions are recommended to minimize this problem.  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