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   773篇
  免费   86篇
  国内免费   4篇
儿科学   50篇
妇产科学   6篇
基础医学   124篇
口腔科学   10篇
临床医学   86篇
内科学   160篇
皮肤病学   9篇
神经病学   47篇
特种医学   108篇
外科学   88篇
综合类   9篇
预防医学   88篇
眼科学   16篇
药学   35篇
  2篇
肿瘤学   25篇
  2023年   7篇
  2021年   4篇
  2020年   5篇
  2019年   6篇
  2018年   12篇
  2017年   13篇
  2016年   7篇
  2015年   11篇
  2014年   21篇
  2013年   26篇
  2012年   38篇
  2011年   31篇
  2010年   30篇
  2009年   36篇
  2008年   32篇
  2007年   30篇
  2006年   28篇
  2005年   39篇
  2004年   24篇
  2003年   16篇
  2002年   23篇
  2001年   20篇
  2000年   17篇
  1999年   22篇
  1998年   24篇
  1997年   20篇
  1996年   20篇
  1995年   21篇
  1994年   18篇
  1993年   11篇
  1992年   12篇
  1991年   19篇
  1990年   17篇
  1989年   24篇
  1988年   14篇
  1987年   22篇
  1986年   19篇
  1985年   19篇
  1984年   9篇
  1983年   10篇
  1982年   5篇
  1981年   3篇
  1980年   9篇
  1979年   18篇
  1978年   9篇
  1977年   5篇
  1976年   10篇
  1975年   4篇
  1974年   4篇
  1958年   2篇
排序方式: 共有863条查询结果,搜索用时 343 毫秒
1.
牙科医生对口腔卫生服务体系的评价   总被引:1,自引:0,他引:1  
目的 :分析牙科医生的日常工作量和牙医对口腔卫生服务的态度评价 ,有助于口腔卫生服务体系的制定和评价。方法 :根据武汉市卫生部门登记在册的牙科医生 ,采用整群抽样的方法随机选择 2 5 0名牙科医生进行开放式问卷调查。结果 :所调查的 2 5 0名样本中 ,5 2 %为女性 ,牙科医生平均工作年限为 11.6年 ,平均使用 0 .8台牙椅 ,每位牙医平均每天看 15个病人。主要工作时间用于充填治疗和拔牙。 93 %的牙医认为中国口腔卫生服务强调治疗而忽视预防保健。结论 :口腔卫生服务应重视口腔预防保健  相似文献   
2.

Background

Clubfoot can be treated nonoperatively, most commonly using a Ponseti approach, or surgically, most often with a comprehensive clubfoot release. Little is known about how these approaches compare with one another at longer term, or how patients treated with these approaches differ in terms of foot function, foot biomechanics, or quality-of-life from individuals who did not have clubfoot as a child.

Questions/purposes

We compared (1) focused physical and radiographic examinations, (2) gait analysis, and (3) quality-of-life measures at long-term followup between groups of adult patients with clubfoot treated either with the Ponseti method of nonsurgical management or a comprehensive surgical release through a Cincinnati incision, and compared these two groups with a control group without clubfoot.

Methods

This was a case control study of individuals treated for clubfoot at two separate institutions with different methods of treatment between 1983 to 1987. One hospital used only the Ponseti method and the other mainly used a comprehensive clubfoot release. There were 42 adults (24 treated surgically, 18 treated with Ponseti method) with isolated clubfoot along with 48 healthy control subjects who agreed to participate in a detailed analysis of physical function, foot biomechanics, and quality-of-life metrics.

Results

Both treatment groups had diminished strength and motion compared with the control subjects on physical examination measures; however, the Ponseti group had significantly greater ankle plantar flexion ROM (p < 0.001), greater ankle plantar flexor (p = 0.031) and evertor (p = 0.012) strength, and a decreased incidence of osteoarthritis in the ankle and foot compared with the surgical group. During gait the surgical group had reduced peak ankle plantar flexion (p = 0.002), and reduced sagittal plane hindfoot (p = 0.009) and forefoot (p = 0.008) ROM during the preswing phase compared with the Ponseti group. The surgical group had the lowest overall ankle power generation during push off compared with the control subjects (p = 0.002). Outcome tools revealed elevated pain levels in the surgical group compared with the Ponseti group (p = 0.008) and lower scores for physical function and quality-of-life for both clubfoot groups compared with age-range matched control subjects (p = 0.01).

Conclusions

Although individuals in each treatment group experienced pain, weakness, and reduced ROM, they were highly functional into early adulthood. As adults the Ponseti group fared better than the surgically treated group because of advantages including increased ROM observed at the physical examination and during gait, greater strength, and less arthritis. This study supports efforts to correct clubfoot with Ponseti casting and minimizing surgery to the joints, and highlights the need to improve methods that promote ROM and strength which are important for adult function.

Level of Evidence

Level III, prognostic study.  相似文献   
3.
We report a case of disseminated meningospondylodiscitis in an elderly diabetic patient caused by Fusarium oxysporum. As the clinical presentation was nonspecific, the diagnosis of the condition could only be arrived at after laboratory and imaging studies. The diagnosis of the condition requires a high index of suspicion. Patient underwent thorough surgical debridement along with a short course of variconazole and remained asymptomatic after 36 months of diagnosis. Fusarium is a large genus of filamentous fungi widely distributed in soil and in association with plants. It is known to cause local infections (nail, cornea) in healthy humans and disseminated infection only in the immunocompromised.  相似文献   
4.
Transforming growth factor beta 1 (TGFbeta-1) and connective tissue growth factor (CCN2) are important mediators of tissue repair and fibrosis, with CCN2 functioning as a downstream mediator of TGFβ-1. Substance P (SP) is also linked to collagen production in tenocytes. A link between SP, TGFbeta-1 and CCN2 has yet to be established in tenocytes or fibrogenic processes. We sought to determine whether SP induces tenocyte proliferation, CCN2, or collagen production via TGFbeta-1 signaling or independently in rat primary tenocytes. Tenocytes were isolated from rat tendons, cultured and stimulated by SP and/or TGFbeta-1. Cultured cells expressed proteins characteristic of tenocytes (vimentin and tenomodulin) and underwent increased proliferation dose dependently after SP and TGFbeta-1 treatments, alone or combined (more than SP alone when combined). SP induced TGFbeta-1 expression in tenocytes in both dose- and time-dependent manners. SP and TGFbeta-1, alone or combined, stimulated CCN2 expression in tenocytes and their supernatants after both 24 and 48 h of stimulation; a response blocked with addition of a TGFbeta-1 receptor inhibitor. In contrast, SP potentiated collagen type I secretion by tenocytes, a response abrogated by the TGFbeta-1 receptor inhibitor after 48 h of stimulation, but not after the shorter 24 h of stimulation. Our findings suggest that both SP and TGFbeta-1 can stimulate tenocyte fibrogenic processes, albeit differently. TGFbeta-1 pathway signaling was involved in CCN2 production at all time points examined, while SP induced collagen type I production independently prior to the onset of signaling through the TGFbeta-1 pathway.  相似文献   
5.
6.
Objectives: Focused assessment with sonography in trauma (FAST) can define life‐threatening injuries in austere settings with remote real‐time review by experienced physicians. This study evaluates vest‐mounted microwave, satellite, and LifeLink communications technology for image clarity and diagnostic accuracy during remote transmission of FAST examinations. Methods: Using a SonoSite, FAST was obtained on three patients with pericardial and intraperitoneal effusions and two control subjects in a remotely located U.S. Army Combat Support Hospital. A miniature vest‐mounted video transmitter attached to the SonoSite sent wireless ultrasound video 20 m to a receiving antenna. The signal was then transferred over VSAT satellite systems at 512 kilobaud per second (kbps), INMARSAT satellite systems at 64 kbps, and over LifeLink on a moving ambulance through a metropolitan wireless traffic–management network. Clarity and absence or presence of effusions were recorded by 15 staff emergency physicians. Results: Average sensitivity, specificity, and accuracy were 87% (95% confidence interval [CI] = 79% to 95%), 85% (95% CI = 81% to 89%), and 86% (95% CI = 82% to 90%) for the Premier Wireless Vest; 98% (95% CI = 97% to 99%), 83% (95% CI = 75% to 91%), and 86% (95% CI = 82% to 90%) for VSAT; 95% (95% CI = 94% to 96%), 70% (95% CI = 58% to 82%), and 75% (95% CI = 70% to 80%) for INMARSAT; and 82% (95% CI = 73% to 91%), 83% (95% CI = 74% to 92%), and 82% (95% CI = 78% to 86%) for LifeLink with clarity of 3.0 (95% CI = 2.7 to 3.3), 2.9 (95% CI = 2.6 to 3.2), 1.3 (95% CI = 1.2 to 1.4), and 2.1 (95% CI = 1.8 to 2.4), respectively. Conclusions: Accuracy correlated with clarity. Roaming vest transmission of FAST provides interpretable, diagnostic imagery at the distances used in this study. VSAT provided the best clarity and diagnostic value with the lighter, more portable INMARSAT serving a lesser role for remote clinical interpretation. LifeLink performed well, and further infrastructure improvements may increase clarity and accuracy.  相似文献   
7.
2',3'-Dideoxycytidine (DDC) was evaluated for prophylactic antiviral activity in vitro and in vivo, using the feline leukemia virus (FeLV)-cat animal model. In vitro antiviral activity of DDC against FeLV was dependent upon the target cell used for infection. DDC (5 to 10 microM) inhibited FeLV infection of feline lymphoid cells by greater than 80%, while 6.07 to 12.13 microM DDC was required to similarly inhibit infection of feline fibroblasts. However, 43 to 384 microM DDC was needed to inhibit FeLV infection of primary bone marrow cells by greater than 80%. These in vitro results suggest that, although relatively low doses of DDC may be adequate to prevent infection of feline lymphoid cells, 8- to 80-times-higher doses may be necessary to block infection of bone marrow cells, a primary target cell type for FeLV infection. In vivo studies with DDC consisted of pharmacokinetic and toxicity determinations and evaluation of the prophylactic antiviral activity against FeLV in cats. Clearance and half-life values for DDC in cats were 6.5 ml/min per kg and 54.7 min, respectively. In the prophylactic studies, DDC was administered by continuous intravenous infusion at doses of 22, 15, 10, and 5 mg/kg per h for 28 days in most animals. Cats were challenged intravenously with FeLV 1 to 3 days after drug treatment began. Doses of 22 and 15 mg/kg per h were extremely toxic, causing death in 8 of 10 cats. The mg/kg per h dose was slightly toxic, causing chronic progressive thrombocytopenia over the 28-day treatment period. Of 10 cats given 10 to 5 mg of DDC per kg per h, only one was completely protected from FeLV antigenemia. However, conversion to positive FeLV antigenemia status was delayed by 2 to 7 weeks in seven of nine remaining animals. Interestingly, FeLV infection of bone marrow cells, as indicated by FELV antigen in peripheral blood neutrophils, was only slightly delayed by 0 to 2 weeks, except in the case of the one protected cat, and usually preceded conversion to antigenemia. This pattern of neutrophils becoming antigen positive before detection of antigenemia was not seen in FeLV challenge control animals and indicates that the antiviral activity of DDC may be incomplete during DDC treatment. Results of our in vitro and in vivo studies suggest that feline bone marrow cells may remain partially susceptible to FeLV infection at tolerated doses, while other somatic target tissues (i.e., lymphoid or epithelial tissues) may be protected from infection. Incomplete inhibition of FeLV infection permitted focal bone marrow infection to develop in cats given DDC. These loci of infection served as virus reservoirs which, subsequent to discontinuation of DDC treatment, permitted spread of infection to tissues previously protected during treatment.  相似文献   
8.
Blood transfusion is one of the principal routes of transmission of Chagas' disease, a major endemic disease in Latin America. Methods for blood screening are not accurate and may yield false results that lead to high social and economic costs. This study compares two methods of diagnosing Chagas' disease (indirect immunofluorescence and hemagglutination) and several enzyme-linked immunosorbent assays (ELISAs) with regard to specificity and sensitivity, by using human sera with known serologic and parasitologic characteristics, as well as samples with discrepant results on conventional serologic tests. An ELISA using recombinant antigens showed no cross-reactivity with sera that were positive for other diseases. All evaluated ELISAs performed well, and their use may lead to a reduction of more than 50 percent in the number of discordant sera. Further improvements are needed in view of the complexity of the serologic diagnosis of Chagas' disease.  相似文献   
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