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   932篇
  免费   60篇
  国内免费   9篇
耳鼻咽喉   6篇
儿科学   102篇
妇产科学   17篇
基础医学   102篇
口腔科学   44篇
临床医学   73篇
内科学   186篇
皮肤病学   41篇
神经病学   29篇
特种医学   150篇
外国民族医学   1篇
外科学   69篇
综合类   46篇
预防医学   55篇
眼科学   5篇
药学   45篇
中国医学   1篇
肿瘤学   29篇
  2020年   6篇
  2019年   7篇
  2018年   11篇
  2017年   17篇
  2016年   17篇
  2015年   27篇
  2014年   21篇
  2013年   30篇
  2012年   23篇
  2011年   25篇
  2010年   32篇
  2009年   50篇
  2008年   32篇
  2007年   22篇
  2006年   31篇
  2005年   22篇
  2004年   40篇
  2003年   23篇
  2002年   13篇
  2001年   9篇
  2000年   12篇
  1999年   19篇
  1998年   54篇
  1997年   63篇
  1996年   57篇
  1995年   42篇
  1994年   40篇
  1993年   37篇
  1992年   8篇
  1991年   11篇
  1990年   16篇
  1989年   14篇
  1988年   22篇
  1987年   24篇
  1986年   21篇
  1985年   9篇
  1984年   4篇
  1983年   8篇
  1982年   18篇
  1981年   3篇
  1980年   10篇
  1979年   4篇
  1978年   4篇
  1977年   6篇
  1976年   6篇
  1975年   2篇
  1968年   4篇
  1965年   2篇
  1963年   3篇
  1959年   3篇
排序方式: 共有1001条查询结果,搜索用时 15 毫秒
991.
AIMS: To assess outcomes of young patients with osteonecrosis (ON) treated with pamidronate in terms of relief of pain, prevention of progress and bony collapse of involved area. PATIENTS AND METHODS: A non-randomised interventional study in six patients with a history of acute lymphoblastic leukaemia (ALL) for which treatment protocols included long-term, high dose use of glucocorticoids. Subsequent development of ON was treated with a bisphosphonate (pamidronate) for 2 years. Mobility and pain control were assessed regularly with MRI and X-ray of affected areas at 0, 12 and 24 months. RESULTS: Reduction in pain was reported in four of six patients in the first year with increased mobility. Two patients who had radiological evidence of joint destruction prior to treatment and when continued on corticosteroids reported no improvement in pain or mobility. In the second year, patients who started treatment in the first few months after diagnosis were stable while patients who had treatment initiated later deteriorated but had less pain than prior to treatment with pamidronate. MRIs of affected areas were completely unchanged over 2 years. X-rays revealed no new bony collapse in four of six patients after 12 months of treatment. However, three of six patients continued to undergo extensive collapse of femoral heads (one at 12 months, two at 24 months) and all these required urgent hip replacement. CONCLUSION: Pamidronate treatment has a palliative effect in control of pain and may delay the natural history of bony collapse in the acute phase of ON, especially in early treated patients, but does not prevent late bone collapse and joint destruction in corticosteroid treated patients with ALL. Larger studies are needed to provide evidence as to whether bisphosphonate is indicated for treatment of ON for patients using corticosteroids.  相似文献   
992.
BACKGROUND: Allergen challenge in allergic rhinitis patients leads to local eosinophilia and Th2-type cytokine expression. Natural exposure to grass pollen is additionally characterized by epithelial mast-cell infiltration. We hypothesized that perennial allergic rhinitis is also associated with T-cell and eosinophil infiltration of the nasal mucosa, local Th2-type cytokine expression, and increased numbers of nasal epithelial mast cells. METHODS: Nasal biopsies from perennial allergic rhinitis patients and controls were analysed by immunocytochemistry for different cell populations and in situ hybridization for cytokine mRNA-expressing cells. RESULTS: Perennial allergic rhinitis was associated with increased numbers of submucosal CD3+ T cells (P=0.05), EG2+ activated eosinophils (P=0.01), and CD68+ macrophages (P=0.01) compared to controls. Epithelial, but not submucosal, tryptase-positive mast cells were also elevated in rhinitics compared to controls (P=0.01). The numbers of cells expressing interleukin (IL)-5 were higher (P=0.01) and the numbers of cells expressing IL-2 were lower (P=0.04) in rhinitic patients than controls. There were no significant differences for either IL-4 or interferon-gamma between the groups. CONCLUSIONS: Perennial allergic rhinitis is characterized by mast-cell migration into the epithelium; submucosal infiltration by T cells, eosinophils, and macrophages; and an imbalance in local T-cell cytokine production in favour of enhanced IL-5 and reduced IL-2 expression.  相似文献   
993.
We studied the effects of cis-retinoic acid (cisRA) on the clonogenic growth of samples of leukemic cells from 35 patients with acute nonlymphocytic leukemia (ANLL). We observed significant inhibition of leukemic colony growth in 17 samples by 10(-7) to 10(-6)M cisRA. However, we found that retinoid exposure resulted in striking stimulation of clonal growth in ten samples at the same drug concentrations. With the exception of cases with promyelocytic features, there was no morphologic or functional evidence that cisRA induced the leukemic blasts to differentiate. Both inhibition and stimulation were dose-dependent and observable at pharmacologically achievable levels of cisRA. Leukemic cells with monocytic features more frequently demonstrated a stimulatory response than did those without monocytic features. Depletion of T lymphocytes and monocytes did not alter the type of growth response. Assays for cellular retinoic acid- binding protein (CRABP) were performed on five samples (two with inhibitory growth responses, two with stimulatory responses, and one with no growth) and failed to reveal detectable levels of CRABP in any case. The addition of cisRA to liquid suspensions of leukemic cells produced no significant change in the number of viable cells. We conclude that the effects of cisRA on leukemic colony growth are not cytotoxic and not mediated by T lymphocytes, monocytes, or CRABP. More importantly, cisRA appears to enhance the growth of certain human leukemia cells in vitro. Taking into account the increasing use of retinoids in clinical trials for patients with leukemia, the latter findings may represent a significant cautionary note.  相似文献   
994.
A technique is presented of securing the cartilaginous nasal septum using titanium mini-plates in the repair of a complex open comminuted type I nasoethmoid fracture, with internal impaction of the external cartilaginous nose. This technique allows primary skin closure and obviates the need for external metal-work and the attendant potential complications.  相似文献   
995.
Aim  The intent of our study was to determine the efficacy of oral naltrexone, an opiod antagonist, in the treatment of pruritus in patients with chronic eczema.
Methods  This double-blind, placebo-controlled study recruited 38 patients with eczema complaining from pruritus. Pruritus scores were evaluated. Patients were given placebo ( n  = 20) or naltrexone 50 mg ( n  = 18) for 2 weeks period. During the study, pruritus scores based on visual analogue scale system (VAS) were assessed three times: at the start of study, after 1 week, and after 2 weeks.
Results  In both groups, decreased VAS scores were observed, but naltrexone showed to be significantly more effective than placebo in decreasing VAS score after 1 week ( P <  0.005) and 2 weeks ( P <  0.001).
Conclusion  Naltrexone is more effective than placebo in the treatment of pruritus in patient with eczema. Naltrexone might be considered as an adjunct treatment in the treatment of pruritus. However, further studies in this aspect are highly fostered.

Conflicts of interest


This study and the authors were not supported by any company with a vested interest in the product being studied and the project was funded by Skin Research Center.  相似文献   
996.
目的了解有严重躯体疾病的老年自杀死亡者的特征并比较有无精神障碍者特征的异同。方法由精神科医师运用心理解剖方法对全国23个疾病监测点上报的≥55岁的304例自杀案例的家属和周围知情人进行调查,分析其中178例(58.6%)报告自杀死亡前1年内有严重躯体疾病者的自杀特征。结果178例自杀死亡者中,女性占41.6%;79.2%居住在乡村;58.4%从未上过学;38.8%丧偶;25.8%有自杀未遂既往史;10.7%一级血缘亲属有自杀行为;43.3%服农药或鼠药自杀,32.6%上吊;68.0%自杀当时有精神障碍,主要是重性抑郁障碍;仅5.1%自杀当时有人在场。有、无精神障碍者在社会人口经济学特征、有无自杀未遂史和自杀行为家族史、负性生活事件导致的慢性心理压力和急性应激强度以及自杀前一个月的生命质量等方面的差异无统计学意义(P均大于0.05)。结论有严重躯体疾病老年人自杀死亡最常见的两种方式是服毒和上吊,2/3有精神障碍,但有无精神障碍者的自杀相关特征无明显不同。  相似文献   
997.
998.
一所综合医院七年间因自杀急诊者的临床特征分析   总被引:5,自引:0,他引:5  
目的 探讨在北京大型综合医院急诊科抢救自杀者的特征及其动态分布。方法 对 1995~ 2 0 0 1年一所综合医院急诊室登记表中诊断为自杀的患者 ,按自编回顾性调查表进行筛查并记录其特征。结果  7年间共有15 34例自杀患者 ,占急诊室就诊人数的 2 94‰ ,未见逐年上升或下降的趋势 ;女性明显多于男性 (男∶女 =1∶2 6 ) ;年龄以青壮年为主 ,平均 ( 33 3± 15 1)岁 ;90 3%的自杀方式是服毒 ( 75 6 %使用治疗性药 ) ;17例 ( 1 1% )自杀死亡 ;春、夏季自杀患者高于秋、冬季 ;多数在晚 6~ 12时急诊 ,80 4 %在院抢救治疗时间少于 1天。结论 自杀已成为综合医院急诊患者中常见的致命问题 ,在急诊工作中应采取相应的治疗及心理干预措施  相似文献   
999.
A variant of von Willebrand disease (vWD) was identified in six members of a kindred spanning four generations. The proband was a 46-year-old woman with a lifelong history of bleeding, a prolonged bleeding time (> 15 minutes), markedly elevated von Willebrand factor (vWF) antigen (vWF:Ag = 2.09 U/mL), slightly reduced ristocetin cofactor activity, and a plasma vWF multimer pattern similar to that of vWD type IIC. Similar findings were observed in her three children, mother, and brother. In affected family members, platelet and plasma vWF multimer patterns were discrepant with higher molecular weight multimers observed in platelet vWF. Following a 1-Des-amino-8-D-arginine vasopressin (DDAVP) challenge, the proband failed to normalize her bleeding time even though vWF: Ag rose by 70% and higher molecular weight multimers were increased slightly. Genetic studies were consistent with autosomal dominant inheritance of a mutation within the vWF gene. By sequencing of cloned genomic DNA, mutations were excluded in exons 4, 5, 14, and 15, which encode regions of the vWF propeptide proposed to be important in multimer biosynthesis. Mutations also were excluded in exons 28 to 31, which encompass the known mutations that cause vWD types IIA, IIB, and B. This new variant of vWD, characterized by autosomal dominant inheritance, a qualitative defect that resembles vWD type IIC, and increased plasma vWF:Ag, was tentatively designated vWD type IIC Miami.  相似文献   
1000.
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