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   15843篇
  免费   1011篇
  国内免费   52篇
耳鼻咽喉   101篇
儿科学   542篇
妇产科学   518篇
基础医学   1961篇
口腔科学   238篇
临床医学   2186篇
内科学   2900篇
皮肤病学   291篇
神经病学   1626篇
特种医学   315篇
外科学   1438篇
综合类   137篇
现状与发展   1篇
一般理论   16篇
预防医学   2230篇
眼科学   345篇
药学   1108篇
中国医学   23篇
肿瘤学   930篇
  2023年   98篇
  2022年   160篇
  2021年   397篇
  2020年   220篇
  2019年   406篇
  2018年   452篇
  2017年   300篇
  2016年   351篇
  2015年   426篇
  2014年   576篇
  2013年   854篇
  2012年   1192篇
  2011年   1266篇
  2010年   696篇
  2009年   572篇
  2008年   1105篇
  2007年   1099篇
  2006年   1081篇
  2005年   1059篇
  2004年   996篇
  2003年   949篇
  2002年   888篇
  2001年   114篇
  2000年   91篇
  1999年   123篇
  1998年   152篇
  1997年   137篇
  1996年   125篇
  1995年   123篇
  1994年   71篇
  1993年   92篇
  1992年   64篇
  1991年   60篇
  1990年   51篇
  1989年   42篇
  1988年   55篇
  1987年   36篇
  1986年   40篇
  1985年   34篇
  1984年   49篇
  1983年   40篇
  1982年   46篇
  1981年   46篇
  1980年   34篇
  1979年   17篇
  1978年   20篇
  1977年   12篇
  1976年   13篇
  1975年   13篇
  1973年   13篇
排序方式: 共有10000条查询结果,搜索用时 437 毫秒
71.
OBJECTIVE: The purpose of this study was to determine the efficacy and safety of a targeted narrow band UVB/UVA1 therapy for the treatment of striae alba. METHODS: Fourteen individuals with skin types II-VI were enrolled in this 22-week trial that consisted of up to 10 treatments with a combination of UVB/UVA1 (MultiClear, Curelight Ltd, Israel). Participants were treated with a maximum of 10 treatments unless 100% repigmentation of stretch was achieved prior to the tenth treatment. Biopsies were taken from willing participants at baseline, immediately after the final treatment and 12 weeks after the last treatment. RESULTS: Nine participants completed all treatment visits. After the final treatment, all the participants had >51% repigmentation of the treated striae. At the 4-week follow-up visit, 67% of participants had greater than 51% improvement, and 56% had greater than 51% improvement at the 8-week and 12-week follow-ups. Hyperpigmentation of striae was seen in >50% of the participants treated. The pretreatment biopsies were confirmatory of striae. There were no diagnostic light microscopic differences in the 4-week post-treatment biopsy set available in one patient. CONCLUSION: This high intensity UVB\UVA1 device is an effective and safe modality for the short-term repigmentation of hypopigmented stretch marks. Additional morphologic studies over time are needed to confirm these clinical findings.  相似文献   
72.
PURPOSE: While the mode of inheritance of a genetic condition has long been considered to have not only medical, but also psychosocial consequences for families, this supposition has never been tested. METHODS: We surveyed 112 members of 51 families (59% response) with chronic granulomatous disease to determine the influence of mode of inheritance on parents', siblings', and patients' (1) knowledge of inheritance and reproductive risk; (2) concern about risk to future family-members; (3) feelings of guilt and blame; and (4) feelings of stigmatization. Ninety-six members of 51 families (49% response) with Duchenne/Becker muscular dystrophy and spinal muscular atrophy types II/III were also studied. RESULTS: X-linked families had better understanding of inheritance (P < 0.001) and reproductive risks (P < 0.01). X-linked mothers worried more about risks to future generations; other autosomal-recessive family members were as worried. X-linked mothers were more likely to feel guilty (P < 0.01) and blame themselves (P < 0.001). X-linked fathers blamed their child's mother (P < 0.05) and X-linked mothers felt more blamed by the father (P < 0.01). X-linked family-members were more likely to consider being a carrier stigmatizing (P < 0.05). CONCLUSION: When providing genetic counseling, attention should be given to guilt and blame in X-linked families and understanding reproductive risks in autosomal recessive families.  相似文献   
73.
Use of herbal supplements for chronic liver disease.   总被引:3,自引:0,他引:3  
BACKGROUND & AIMS: Complementary and alternative medicine (CAM) is becoming popular among patients with liver disease. Although there is a growing body of evidence regarding potential mechanisms of action of these and other herbs, caution must be used to interpret the results of the few clinical trials available. Our goal was to discuss the biologic rationale for the use of specific herbs (silymarin, glycyrrhizin, sho-saiko-to, Phyllanthus amarus , Picrorrhiza kurroa , Compound 861, CH-100, and LIV.52) in the treatment of chronic liver diseases, as well as the evidence for their efficacy and adverse effects according to clinical trials. METHODS: Because of the relative paucity of clinical studies using herbs, every trial published in English was reviewed. RESULTS: Although many trials suggest that these herbs can decrease serum transaminase levels, the effects on hepatic histopathology and long-term survival are either poorly studied or conflicting. LIV.52 has been withdrawn from the market because of deleterious effects in patients with liver disease. CONCLUSIONS: Based on current evidence, we cannot recommend the use of herbal supplements for the routine treatment of any chronic liver disease and further well-designed clinical trials are necessary.  相似文献   
74.
75.
Journal of Neurology - REM sleep abnormalities are frequently encountered in disorders with alpha-synuclein pathology including Parkinson’s disease, multiple system atrophy, and dementia with...  相似文献   
76.
77.
Approximately 5% of Americans over age 65, or 1.5 million individuals, currently reside in the nations's 20,000 nursing homes. The authors present material that lead to three conclusions about this population. First, nutritional deficiencies are common underlying causes of adverse clinical outcomes. Second, nutritional deficiencies are frequently not recognized. Third, opportunities for preventing or correcting undernutrition exist, provided that the significant and reversible nature of the nutrient deficiencies are identified.  相似文献   
78.
On-site testing of 157 poultry processors disclosed that 50% had three or more abnormal upper extremity findings out of a total of 22 possibles. The average worker had five to six abnormal findings. Impaired pinch strength, decreased vibration sensitivity in the fingertips, and reports of current numbness were the most prevalent. Of workers with signs, 25% reported no symptoms, whereas only 8% of workers reported symptoms but had no signs. The investigators concluded that this measurement method has utility for assessments of worker populations to determine prevalence of CTDs and, potentially, for preclinical detection of these disorders to permit early intervention, reduce medical costs, and minimize disability. The need for accurate measurement to enhance early detection and prevention is discussed.  相似文献   
79.
Dorsoventral patterning of the Drosophila embryo requires Nudel, a large mosaic protein with a protease domain. Previous studies have implicated Nudel's protease domain as the trigger of a proteolytic cascade that activates the Toll signaling pathway to establish dorsoventral polarity in the embryo. However, the function of other regions of Nudel has been unclear. By using two-dimensional gel electrophoresis and site-directed mutagenesis, we have obtained evidence that the N-terminal region of Nudel contains a site for glycosaminoglycan (GAG) attachment that is required for dorsoventral patterning. Disruption of this site blocks a disulfide-based association between N- and C-terminal Nudel polypeptides and proteolytic activation of Nudel's protease domain. We discuss how a GAG chain on Nudel might be required for Nudel protease activation.  相似文献   
80.
Despite the existence of a well-defined abstinence syndrome in offspring of opiate-dependent mothers, the mechanisms involved in neonatal abstinence remain unclear. The goal of the present study was to determine the contribution of noradrenergic neurons in the opiate abstinence syndrome in neonatal rats (10 days old). First, the ability of the α2-adrenergic agonist, clonidine to attenuate the symptoms of neonatal opiate abstinence precipitated by naloxone was determined. Secondly, the activity of noradrenergic neurons was determined by measuring postmortem levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) in the hypothalamus, hippocampus and cortex in opiate-abstinent pups. Neonatal opiate abstinence was characterized by an increased incidence of wall climbing, tremors and mouthing. Acute treatment with morphine and naloxone in chronic saline-treated pups also produced the tremor, albeit less severe than in pups treated chronically with morphine. Clonidine (0.2 mg/kg) attenuated the expression of tremor and mouthing in neonates, but increased wall climbing. Clonidine elicited wall climbing in opiate-naive neonates. Treatment with morphine followed by naltrexone increased MHPG levels in all of the brain areas examined, irrespective of the chronic treatment, but naltrexone treatment elicited a larger increase in MHPG levels in pups treated chronically with morphine. Acute morphine treatment increased MHPG levels only in the hypothalamus. The results of the present study provide behavioral and neurochemical data supporting the hypothesis that noradrenergic hyperactivity plays a role in neonatal opiate abstinence.  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