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   1030篇
  免费   55篇
  国内免费   4篇
耳鼻咽喉   11篇
儿科学   18篇
妇产科学   15篇
基础医学   187篇
口腔科学   23篇
临床医学   117篇
内科学   192篇
皮肤病学   13篇
神经病学   97篇
特种医学   49篇
外国民族医学   1篇
外科学   159篇
综合类   15篇
预防医学   51篇
眼科学   28篇
药学   59篇
中国医学   11篇
肿瘤学   43篇
  2024年   3篇
  2023年   18篇
  2022年   44篇
  2021年   100篇
  2020年   50篇
  2019年   71篇
  2018年   54篇
  2017年   60篇
  2016年   42篇
  2015年   43篇
  2014年   67篇
  2013年   71篇
  2012年   102篇
  2011年   83篇
  2010年   35篇
  2009年   28篇
  2008年   44篇
  2007年   34篇
  2006年   34篇
  2005年   26篇
  2004年   16篇
  2003年   17篇
  2002年   13篇
  2001年   7篇
  2000年   4篇
  1999年   1篇
  1998年   1篇
  1996年   4篇
  1995年   1篇
  1994年   2篇
  1992年   3篇
  1991年   2篇
  1989年   1篇
  1987年   1篇
  1984年   1篇
  1983年   1篇
  1981年   1篇
  1980年   1篇
  1978年   1篇
  1976年   1篇
  1974年   1篇
排序方式: 共有1089条查询结果,搜索用时 15 毫秒
101.
This study was designed to evaluate the efficacy of gabapentin (GBP) in the treatment of SUNCT syndrome on a relatively large sample of Persian patients. Eight patients with SUNCT syndrome underwent a 4-week, open-label, daily treatment of 600-900 mg GBP. The frequency, intensity and duration of attacks were compared before and after the trial. After 4 weeks of treatment, intensity, duration and frequency of headaches were significantly (P < 0.05) reduced. In addition, five patients (62.5%) were completely relieved from headaches, and in the other three patients the mean intensity, frequency and duration of headaches were decreased notably. In this study, GBP was well tolerated and no unfavourable side-effects were reported. After the end of the trial all patients continued the medication, and after 3 months none reported undesired side-effects or return of the headaches to the pre-treatment status. Our patients had a significant response to GBP, and considering other case reports on the effectiveness of GBP in the treatment of SUNCT syndrome, we propose that, taking into account the good side-effect profile and lack of interactions of GBP, this drug could be considered as an option for the treatment of SUNCT.  相似文献   
102.
103.
104.
105.
106.
Paediatric burns are a major public health issue because of long-term physical, psychological and social consequences and the high cost of treatment. The aim of this study was to design and evaluate a mobile-based self-management application for caregivers of children with severe burns. A participatory design technique was employed to develop the Burn application, which included three main phases: the determination of application requirements, the design and evaluation of the low-fidelity prototype, and the design and evaluation of the high-fidelity prototypes. In the first phase, application requirements were determined via validated paper questionnaires using the Delphi technique. In the second step, a low-fidelity prototype was prepared using conceptual models and evaluated through a focus group with specialists. Seven specialists reviewed the application and evaluated how this prototype meets functional requirements and objectives. The third phase was performed in three stages. First, the high-fidelity prototype was designed and developed by the JAVA programming language. Second, a cognitive walk-through was carried out to show how users can interact with the mobile application and how it works. Third, this program was installed on the mobile phones of 28 caregivers of burned children, eight IT experts, and two general surgeries, and the prototype's usability was evaluated. In the present study, most caregivers of children with burns stated that after discharge, they face problems regarding infection control and wound care (4.07) and how to perform physical activity (4.12). User registration, educational materials, caregiver-clinician communication, chat box, and appointment booking, safe login were the most important characteristic of the Burn application. Mean usability evaluation scores were in the range of 7.92 ± 0.238 to 8.10 ± 0.103, which is considered at a “good” level. From the Burn program design experience, it can be concluded that co-design with health care specialists can significantly support and meet the specialists' and patients' needs and ensure the program's usefulness. In addition, application evaluation by users involved and not involved in the application design process can help enhance usability.  相似文献   
107.
An amplitude-dependent downshift in the fundamental wave spectrum of a propagating ultrasonic pulse caused by non-linear wave propagation is described. The effects of non-linearity and the associated downshift on spatial resolution are also studied. The amounts of downshift and spatial resolution are extracted from the numerically simulated beam profile based on the KZK equation. Results for a 25-MHz transducer reveal that non-linear effects can lead to 58% additional downshift in the centre frequency of a pulse compared with a linear case with downshift caused only by attenuation. This additional downshift causes about 50% degradation in axial resolution. However, as the beam becomes narrower from the non-linear effects, the overall effect of non-linearity still leads to improved lateral resolution (≤26%). Therefore, as non-linearity increases with wave pressure, it is concluded that the increase in source pressure improves lateral resolution and degrades axial resolution.  相似文献   
108.
Objective: To identify serodiagnosis and quantification of Toxoplasma gondii(T. gondii) infection among pregnant women in Salmas, northwest of Iran. Methods: In this crosssectional study, 276 blood samples were collected from pregnant women referred to the health care centers in Salmas city. The demographic variables were also recorded. Titers of antiToxoplasma IgM and IgG antibodies(Ab) were determined using the chemiluminescence immunoassay. Quantitative real-time PCR targeting the T. gondii repeated element gene was also performed on the blood sample. Results: Out of all, 19.92%(55/276) and 2.17%(6/276) patients were seropositive for anti-Toxoplasma IgG and IgM Ab, respectively. Moreover, the presence of T. gondii DNA was observed in 12.31%(34/276) blood samples. A significant relationship was observed between the IgG Ab seropositivity and contact with the cat as a risk factor(P=0.022). Conclusions: The seroprevalence rate of T. gondii infection in pregnant women is relatively low. Consequently, the seronegative pregnant women are at risk, and a considerable rate of positive blood samples for the presence of parasite's DNA should not be ignored. Besides, quantitative real-time PCR could be considered as an accurate method for diagnosis of acute toxoplasmosis especially when the precise results are of the most importance in pregnancy. Limiting contact with cats is also suggested for pregnant women.  相似文献   
109.

Objective

To estimate the frequency of acquired ADAMTS13 deficiency in severe cases of Hemiscorpius lepturus stung patients and the frequency of acute kidney injury (AKI) in these patients.

Methods

Sixty scorpion stung children who were referred with severe hemolysis and hemoglobinuria were studied. None of them had received blood products and no one had a past medical history of renal failure.

Results

Plasma levels of ADAMTS13 and ADAMTS13 antibody (IgG) were measured using ELISA. ADAMTS13 was decreased in 91.7 % of patients and the anti-ADAMTS13 antibody (Ab) was increased in 98.3 %. ADAMTS13 decreased in all of the patients with acute kidney injury and none of those with normal levels of ADAMTS13 developed renal failure; all patients with AKI had also increased levels of ADAMTS13Ab. Acute kidney injury was found in 23.3 % and had significant association with severe anemia, thrombocytopenia, pyuria, hematuria and considerable proteinuria (p?<?0.001). Disseminated intravascular coagulation (DIC) and Hemolytic uremic syndrome (HUS) developed in 6.7 % and 10 % respectively.

Conclusions

The index findings demonstrate that Hemiscorpius lepturus sting is usually associated with ADAMTS13 deficiency, and increased ADAMTS13 autoantibody. These combined mechanisms may contribute to scorpion sting-induced coagulopathies and may predispose patients to develop DIC and HUS.  相似文献   
110.
Safety standards for clinical diagnostic ultrasonic devices were developed for use in relatively low-frequency systems (1–10 MHz), under the assumption that non-linear effects would be negligible. This article reviews ways in which neglecting non-linear wave propagation affects the measurements and calculations required to comply with safety standards and U.S. Food and Drug Administration guidance that recognizes these standards. An attempt is made to evaluate whether ignoring non-linear effects could result in significant error in the exposure quantities defined in these standards at either low or high frequencies, based on published literature. This article maintains that although non-linear effects have been considered in some parts of safety standards related to hydrophone requirements, the coverage is inadequate, especially for modern equipment with high working frequencies. A new approach is required to assess the magnitude of thermal heating for recently developed high-frequency systems to incorporate non-linear effects. In contrast, the current approach for evaluating the risk of cavitation can be used after appropriate modifications.  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