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   2845篇
  免费   136篇
  国内免费   4篇
耳鼻咽喉   73篇
儿科学   133篇
妇产科学   38篇
基础医学   241篇
口腔科学   62篇
临床医学   213篇
内科学   490篇
皮肤病学   21篇
神经病学   224篇
特种医学   176篇
外科学   529篇
综合类   98篇
预防医学   122篇
眼科学   225篇
药学   168篇
中国医学   12篇
肿瘤学   160篇
  2023年   16篇
  2022年   46篇
  2021年   118篇
  2020年   41篇
  2019年   64篇
  2018年   95篇
  2017年   72篇
  2016年   86篇
  2015年   77篇
  2014年   108篇
  2013年   144篇
  2012年   224篇
  2011年   224篇
  2010年   132篇
  2009年   133篇
  2008年   173篇
  2007年   162篇
  2006年   124篇
  2005年   147篇
  2004年   121篇
  2003年   99篇
  2002年   109篇
  2001年   53篇
  2000年   36篇
  1999年   35篇
  1998年   18篇
  1997年   13篇
  1996年   8篇
  1993年   12篇
  1992年   19篇
  1991年   25篇
  1990年   24篇
  1989年   30篇
  1988年   18篇
  1987年   20篇
  1986年   11篇
  1985年   8篇
  1984年   8篇
  1983年   11篇
  1981年   17篇
  1980年   5篇
  1979年   6篇
  1977年   6篇
  1976年   9篇
  1975年   8篇
  1974年   6篇
  1973年   10篇
  1972年   6篇
  1971年   7篇
  1969年   6篇
排序方式: 共有2985条查询结果,搜索用时 31 毫秒
101.
102.
Time-domain analysis of the signal-averaged electrocardiogram (SAECG) can accurately predict risk of sustained ventricular tachycardia (VT) in patients with previous myocardial infarction (MI). Unfortunately, these patients often have bundle branch block (BBB) that obscures late potentials. We hypothesized that wavelet analysis might help predict VT risk in patients with BBB. We identified subjects with coronary disease and BBB who had undergone SAECG and programmed ventricular stimulation (PVS). We applied a modulated Gaussian wavelet to transform the ECG signal and looked for singularities in the wavelet coefficients. SAECG and PVS were obtained in 32 patients. Half had inducible sustained monomorphic VT by PVS and half had no inducible VT. There were no significant clinical differences between the groups. Comparing the number of singularities, we found no significant difference between the groups. Compared to previous work in patients without BBB, our patients with BBB had on average four times more singula- rities using an identical analysis technique. In the presence of BBB, abnormal myocardial activation patterns can generate ECG waveforms with time–frequency characteristics similar to those of cardiac late potentials. Wavelet-based methodologies may have limited ability to distinguish late potentials from the disordered ventricular activation occurring with BBB alone.  相似文献   
103.
Metaphase cytogenetic abnormalities (CAs), especially of chromosome 13 (CA 13), confer a grave prognosis in multiple myeloma even with tandem autotransplantations as applied in Total Therapy I, which enrolled 231 patients between 1989 and 1994. With a median follow-up of almost 9 years, the prognostic implications of all individual CAs, detected prior to treatment and at relapse, were investigated. Among all CAs and standard prognostic factors examined prior to therapy, only hypodiploidy and CA 13 (hypo-13 CA), alone or in combination, were associated with shortest event-free survival and overall survival (OS). The shortest postrelapse OS was observed with hypo-13 CA, which was newly detected in 18 of all 28 patients presenting with this abnormality at relapse. Superior prognosis was associated with the absence of any CA at both diagnosis and relapse (10-year OS, 40%). The lack of independent prognostic implications of other CAs points to a uniquely aggressive behavior of hypo-13 CA (present in 16% of patients at diagnosis). With the use of microarray data in 146 patients enrolled in Total Therapy II, overexpression of cell cycle genes distinguished CA from no CA, especially in cases of del(13) detected by interphase fluorescence in situ hybridization (FISH). FISH 13, resulting in a haploinsufficiency of RB1 and other genes mapping to chromosome 13, as well as activation of IGF1R, appears to have an amplifying effect on cell cycle gene expression, thus providing a molecular explanation for the dire outcome of patients with CA 13 compared with those with other CAs.  相似文献   
104.
The pathogenesis of glycerol-induced myoglobinuric acute renal failure involves ischemia, vascular congestion and reactive oxygen metabolites. In this study, we have investigated for the first time, the role of ferulic acid in attenuating glycerol-induced nephrotoxicity. Male Wistar rats were injected intramuscularly with 8?mL/kg body weight of 50% glycerol, glycerol?+?ferulic acid at the dose of 5, 10, 15, 20 and 25?mg/kg body weight. After 24?h, the rats were sacrificed and the kidneys were removed for histological and immunohistochemical studies. Furthermore, determinations of lipid peroxidation (LPO) as well as antioxidant enzymes were also analyzed; blood, urine samples were collected in order to quantify renal function and nitric oxide generation, respectively. Glycerol-induced rats showed a significant increase in the level of urinary markers assessed in serum as well as kidney and these were reversed upon ferulic acid treatment. A significant increase in urine nitric oxide, serum as well as kidney LPO, decrease in activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and reduced glutathione were observed in glycerol-induced rats. Immunohistochemical study in glycerol-induced rats demonstrated an increase in the level of nuclear factor-kappaB (NF-κB). All these effects induced by glycerol were reduced upon treatment with ferulic acid in a dose-dependent manner. To conclude, ferulic acid enhances antioxidants and decreases NF-κB, thereby protecting the cells against stress induced by glycerol.  相似文献   
105.

Background

Dog bites are a frequent cause of facial and periocular injuries in both children and adults. This aim of this study is to review current practice in the management of facial and periorbital dog bite injuries and to examine the current evidence-base for such treatment strategies.

Methods

Five hundred eighty-seven patients with dog bite injuries requiring surgical intervention were identified from operating theatre records in one tertiary centre over a 9-year period. A retrospective case note review of 104 patients with facial and periorbital dog bite injuries was performed. Data on patient demographics, type of injury, treatment, and outcome was collected and analysed.

Results

The majority of patients were children, with a mean age of 11 years (range 1–91 years). Injuries involved the cheek in 57 cases (55 %), eyelids in 17 cases (16 %), lips in 24 cases (23 %) and nose in 8 cases (8 %). No facial fractures, canalicular, or globe injuries were recorded. All patients underwent irrigation, debridement, and primary wound closure. Surgical repair occurred within 24 h in 19 cases (18.2 %), within 48 h in 71 cases (68.3 %) and within 5 days in 14 cases (13.4 %). Three patients (2.9 %) developed a wound infection. Two patients (1.9 %) required scar revision surgery.

Conclusions

Periorbital and facial dog bite injuries may result in considerable morbidity. However, the majority of injuries are superficial and canalicular injury and bony injury is uncommon. Early wound irrigation, debridement and primary closure results in a good cosmetic outcome with a low risk of infection.

Level of Evidence:

Level IV, risk/prognostic study.  相似文献   
106.
107.

Objectives

The aim of this paper is to summarize different diagnostic criteria as well as probable aetiopathogenesis of bisphosphonates related osteonecrosis of the jaw.

Materials and Methods

The electronic search of peer-reviewed journals were performed in MEDLINE (PubMed) database in order to find the relevant articles on bisphosphonates related osteonecrosis of the jaw (BP-related ONJ). The search was restricted to English language articles, published from January 2002 to May 2013. On the basis of these articles, probable aetiopathogenesis and different diagnostic criteria of BP-related ONJ were summarized.

Results

BP-related ONJ is related to the development of avascular necrosis or dead jaw bones. In recent literature many given hypotheses show the aetiopathogenesis and diagnosis of BP-related ONJ which are interlinked and have multifactorial nature. Their diagnosis revolves around four main diagnostic criteria that differentiate it from other conditions which can delay bone healing.

Conclusions

Factors like potency of bisphosphonates, biology of jaw bone, antiangiogenic property of bisphosphonates and soft tissue toxicity in combination with present infection, other drugs, pre-existing pathologies, compromised immune response and dentoalveolar trauma may lead to development of BP-related ONJ.  相似文献   
108.
The association between dietary patterns and cardiometabolic risk factors is not well understood among adults in India, particularly among those at high risk for diabetes. For this study, we analyzed the data of 1007 participants (age 30–60 years) from baseline and year one and two follow-ups from the Kerala Diabetes Prevention Program using multi-level mixed effects modelling. Dietary intake was measured using a quantitative food frequency questionnaire, and dietary patterns were identified using principal component analysis. Two dietary patterns were identified: a “snack-fruit” pattern (highly loaded with fats and oils, snacks, and fruits) and a “rice-meat-refined wheat” pattern (highly loaded with meat, rice, and refined wheat). The “snack-fruit” pattern was associated with increased triglycerides (mg/dL) (β = 6.76, 95% CI 2.63–10.89), while the “rice-meat-refined wheat” pattern was associated with elevated Hb1Ac (percentage) (β = 0.04, 95% CI 0.01, 0.07) and central obesity (OR 1.16, 95% CI 1.01, 1.34). These findings may help inform designing dietary interventions for the prevention of diabetes and improving cardiometabolic risk factors in high-diabetes-risk individuals in the Indian setting.  相似文献   
109.
110.
Indian Journal of Pediatrics - Youth and adolescents are the priority population to target the interventions as risky behaviors persist and they contribute to almost half of the new Human...  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