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   2794篇
  免费   182篇
  国内免费   23篇
耳鼻咽喉   44篇
儿科学   89篇
妇产科学   37篇
基础医学   389篇
口腔科学   157篇
临床医学   217篇
内科学   696篇
皮肤病学   68篇
神经病学   144篇
特种医学   168篇
外科学   257篇
综合类   118篇
一般理论   1篇
预防医学   277篇
眼科学   26篇
药学   162篇
中国医学   44篇
肿瘤学   105篇
  2023年   17篇
  2022年   76篇
  2021年   95篇
  2020年   62篇
  2019年   92篇
  2018年   106篇
  2017年   64篇
  2016年   67篇
  2015年   91篇
  2014年   118篇
  2013年   122篇
  2012年   195篇
  2011年   195篇
  2010年   115篇
  2009年   101篇
  2008年   147篇
  2007年   137篇
  2006年   105篇
  2005年   113篇
  2004年   73篇
  2003年   62篇
  2002年   83篇
  2001年   50篇
  2000年   51篇
  1999年   42篇
  1998年   56篇
  1997年   48篇
  1996年   37篇
  1995年   25篇
  1994年   34篇
  1993年   24篇
  1992年   25篇
  1991年   15篇
  1990年   20篇
  1989年   31篇
  1988年   19篇
  1987年   43篇
  1986年   18篇
  1985年   29篇
  1984年   17篇
  1983年   18篇
  1982年   20篇
  1981年   12篇
  1979年   10篇
  1978年   11篇
  1977年   10篇
  1976年   12篇
  1973年   11篇
  1969年   10篇
  1968年   11篇
排序方式: 共有2999条查询结果,搜索用时 15 毫秒
101.
102.
This is the second report on the continuing efforts of LAGID to increase the recognition and registration of patients with primary immunodeficiency diseases in 12 Latin American countries: Argentina, Brazil, Chile, Colombia, Costa Rica, Honduras, Mexico, Panama, Paraguay, Peru, Uruguay, and Venezuela. This report reveals that from a total of 3321 patients registered, the most common form of primary immunodeficiency disease was predominantly antibody deficiency (53.2%) with IgA deficiency reported as the most frequent phenotype. This category was followed by 22.6% other well-defined ID syndromes, 9.5% combined T- and B-cell inmunodeficiency, 8.6% phagocytic disorders, 3.3% diseases of immune dysregulation, and 2.8% complement deficiencies. All countries that participated in the first publication in 1998 reported an increase in registered primary immunodeficiency cases, ranging between 10 and 80%. A comparison of the estimated minimal incidence of X-linked agammaglobulinemia, chronic granulomatous disease, and severe combined immunodeficiency between the first report and the present one shows an increase in the reporting of these diseases in all countries. In this report, the estimated minimal incidence of chronic granulomatous disease was between 0.72 and 1.26 cases per 100,000 births in Argentina, Chile, Costa Rica, and Uruguay and the incidence of severe combined immunodeficiency was 1.28 and 3.79 per 100,000 births in Chile and Costa Rica, respectively. However, these diseases are underreported in other participating countries. In addition to a better diagnosis of primary immunodeficiency diseases, more work on improving the registration of patients by each participating country and by countries that have not yet joined LAGID is still needed. Latin American Group for Primary Immunodeficiency Diseases  相似文献   
103.
104.
105.
A previously asymptomatic 15-year-old boy was treated at our institution after an episode of chest pain, palpitation, and syncope while playing in a high school soccer game. The patient's resting electrocardiogram was normal. A transthoracic echocardiogram showed an anomalous left main coronary artery originating from the right sinus of Valsalva. Contrast-enhanced multidetector computed tomography demonstrated clearly that the anomalous vessel coursed between the aorta and the pulmonary trunk (interarterial subtype). Treadmill testing registered several nonsustained polymorphic ventricular tachycardias and transmural myocardial ischaemia in the early recovery phase (ST-elevation up to 5mm in CM5 and V2 leads). The patient underwent bypass grafting. One year later, he remains asymptomatic, and new treadmill tests have been normal. In this patient, severe transmural myocardial ischaemia was detected, possibly due to collapse or vasospasm of the anomalous vessel, triggering life-threatening ventricular arrhythmias.  相似文献   
106.
AIM: The aim of this article is to present a case of Paracoccidioidomycosis with involvement of the oral cavity but without pulmonary manifestations. BACKGROUND: Paracoccidioidomycosis is a fungal infection caused by Paracoccidioides brasiliensis. It is an endemic disease representing a serious health problem for Latin American countries, especially Brazil. This infection primarily affects the lungs of adult men and is acquired through inhalation or accidental inoculation of the fungus. It can spread to other organs and tissues, mainly the oral cavity. Administration of antifungal medication always resolves the disease. REPORT: A 58-year-old black male presented with three painless, ulcerated, mulberry-like granulomatous lesions located in the floor of the mouth, on the superior alveolar ridge, and on the hard palate, which had evolved over a period of two years. Facial asymmetry was observed due to edema in the lower lip and lymphadenopathy. He had smoked for more than six years but showed no evidence of lung alterations, productive cough, or fever. Panoramic radiography showed no signs of a bone lesion in the jaws. Both a radiograph and a CT scan of the thorax showed no areas of nodular infiltration. Fibrobronchoscopic examination of the entire respiratory tract was normal. Biopsies of the oral lesions were performed, and tissue sections exhibited oral mucosa coated with non-keratinized stratified squamous epithelium with acanthosis and focal areas of exocytosis. The underlying connective tissue showed an intense lymphocytic and polymorphonuclear infiltrate in addition to multinuclear giant cells and coagulation necrosis. A special stain used for fungus (the Grocott-Gomori method) was positive. Pulmonary biopsy exhibited aerial spaces containing macrophages, dark granular hemossiderin, and absence of fungus. This was considered normal. In agreement with the recommendation of pneumologists 400 mg/day of ketoconazole was prescribed for the patient. After two months of treatment, even though the oral lesions had resolved completely, the therapy was maintained for six months more. One year after following treatment the patient was in good health and free of any signs of a recurrent infection. SUMMARY: Based on clinical, radiographic, and histologic findings the differential diagnosis included paracoccidioidomycosis and squamous cell carcinoma. Following clinical and biopsy examinations of the oral lesions and the lungs a final diagnosis of paracoccidioidomycosis was made. This is a prime example of oral manifestations of a systemic disease in which the dentist is the initial health care professional to evaluate the patient due to the location of the lesions.  相似文献   
107.
Lasers in Medical Science - Several treatment options are proposed for the management of pelvic floor myofascial pain (PFMP). Manual therapy, such as vaginal stretching (VS), is one of these...  相似文献   
108.
Context: Syzygium cumini (L.) Skeels (Myrtaceae) is a tree with dark purple fruits, popularly known as “jambolão” or “jambolan”. In folk medicine, this plant is used for the treatment of diabetes and inflammatory conditions.

Objective: We investigated the antinociceptive effect of ethanol extract (EE) from S. cumini leaves on orofacial nociception.

Material and methods: The antinociceptive effects of the EE obtained from the leaves of S. cumini were evaluated in mice using formalin- and glutamate-induced orofacial nociception.

Results: ESI-MS/MS analyses demonstrated that major constituents in the analyzed samples coincided with the mass of the phenolic acids and flavonoids. In pharmacological approach, pre-treatment with EE (100, 200, or 400?mg/kg, p.o.) significantly reduced (p?p?G-nitro-l-arginine (l-NOARG). The extract, all doses, also caused a marked inhibition (p?p?Conclusions: We can suggest that the antinociceptive effect of the EE is mediated by peripheral mechanisms, possibly involving KATP channels and the nitric oxide pathways. These effects appear to be related to the presence of flavonoids compounds, such as quercetin.  相似文献   
109.

Introduction

The optimal treatment of high energy tibial fractures remains controversial and a challenging orthopaedic problem. The role of external fixators for all these tibial fractures has been shown to be crucial.

Methods

A five-year consecutive series was reviewed retrospectively, identifying two treatment groups: Ilizarov and Taylor Spatial Frame (TSF; Smith & Nephew, Memphis, TN, US). Fracture healing time was the primary outcome measure.

Results

A total of 112 patients (85 Ilizarov, 37 TSF) were identified for the review with a mean age of 45 years. This was higher in women (57 years) than in men (41 years). There was no significant difference between frame types (p=0.83). The median healing time was 163 days in both groups. There was no significant difference in healing time between smokers and non-smokers (180 vs 165 days respectively, p=0.07), open or closed fractures (p=0.13) or age and healing time (Spearman''s r=0.12, p=0.18). There was no incidence of non-union or re-fracture following frame removal in either group.

Conclusions

Despite the assumption of the rigid construct of the TSF, the median time to union was similar to that of the Ilizarov frame and the TSF therefore can play a significant role in complex tibial fractures.  相似文献   
110.
The aim of this randomized double-blind placebo-controlled study was to investigate the effect of low-level laser therapy (LLLT) on markers of muscle damage (creatine kinase (CK) and strength performance) in the biceps brachii. Twenty-two physically active men were randomized into two groups: placebo and laser. All volunteers were submitted to an exercise-induced muscle damage protocol for biceps brachii (biceps curl, 10 sets of 10 repetitions with load of 50 % of one-repetition maximum test (1RM)). Active LLLT (808 nm; 100 mW; 35.7 W/cm2, 357.14 J/cm2 per point, energy of 1 J per point applied for 10 s on four points of the biceps brachii belly of each arm) or placebo was applied between the sets of the biceps curl exercise. CK activity and maximum strength performance (1RM) were measured before, immediately after, 24, 48, and 72 h after the exercise-induced muscle damage protocol. There was an increase in CK activity after the muscle damage protocol in both groups; however, this increase was attenuated in the laser group compared to the placebo group at 72 h (placebo?=?841 vs. laser?=?357 %; p?<?0.05). Maximum strength performance was decreased immediately after the muscle damage protocol in both groups (p?<?0.05), but at 24, 48, and 72 h, and it returned to the baseline level in both groups. In conclusion, the LLLT attenuated CK activity 72 h after the muscle damage protocol but did not have a positive effect on the recovery of strength performance.  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