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   354篇
  免费   22篇
  国内免费   4篇
耳鼻咽喉   10篇
儿科学   20篇
妇产科学   9篇
基础医学   41篇
口腔科学   1篇
临床医学   30篇
内科学   62篇
皮肤病学   48篇
神经病学   15篇
特种医学   4篇
外科学   51篇
综合类   13篇
预防医学   19篇
眼科学   5篇
药学   28篇
中国医学   2篇
肿瘤学   22篇
  2023年   2篇
  2022年   6篇
  2021年   13篇
  2020年   9篇
  2019年   8篇
  2018年   12篇
  2017年   7篇
  2016年   22篇
  2015年   9篇
  2014年   14篇
  2013年   20篇
  2012年   35篇
  2011年   38篇
  2010年   25篇
  2009年   20篇
  2008年   28篇
  2007年   17篇
  2006年   17篇
  2005年   19篇
  2004年   16篇
  2003年   15篇
  2002年   8篇
  2001年   1篇
  1999年   8篇
  1998年   3篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1991年   2篇
  1989年   1篇
  1975年   2篇
排序方式: 共有380条查询结果,搜索用时 517 毫秒
1.
Angiosarcoma is a rare, highly malignant tumor arising from endothelial cells of small blood vessels. They usually occur in the skin, deep soft tissues, breast and liver. Pleural angiosarcomas are extremely rare and are restricted to case reports in medical literature. It is very difficult to distinguish them from malignant mesotheliomas on clinical, radiological and even histopathological features. Immunohistochemistry is valuable in making the diagnosis, showing negative reactivity for mesothelial markers and positivity for vascular markers. Prognosis is generally dismal except in occasional cases where the disease is localized and amenable for surgical resection. We report a 55-year-old man who presented to us with chest pain, cough and hemoptysis and was diagnosed to have a pleural angiosarcoma.  相似文献   
2.
OBJECTIVE: To evaluate the procedure in terms of technical difficulties, patient satisfaction, symptom relief, recurrence, and further management. STUDY DESIGN: Retrospective study including 41 patients who underwent endoscopic stapling diverticulotomy. Clinical notes were reviewed, and patients were sent a patient satisfaction questionnaire. Statistical analysis was done using the chi(2) square test. SETTING: Teaching hospital. RESULTS: Larger pouches had the best results; 81.578% were satisfied with the surgery, and 86.84% had improved swallowing. Complications presented in 6 patients (15%), including a perforated pouch and an esophageal perforation. Complications were more frequent in small pouches. CONCLUSIONS AND SIGNIFICANCE: Endoscopic stapling diverticulotomy offers rapid recovery in most patients, with early oral intake and short hospital stay. There is a high degree of symptoms relief, and the patient's satisfaction rate is high. The assessment of the pharyngeal pouch size is an important factor when deciding the best management for a patient with a pharyngeal pouch.  相似文献   
3.
The authors have previously demonstrated that the oxidant t-buOOH stimulates phospholipase A(2) (PLA(2)) activity in bovine pulmonary artery endothelial cells (S. Chakraborti et al. American Journal of Physiology, 257, L430-L437, 1989). Herein, the authors sought to investigate the mechanism by which t-buOOH stimulates PLA(2) activity and the role of protein kinase C (PKC) in this scenario. Treatment of bovine pulmonary artery endothelial cells with t-buOOH stimulated an aprotinin-sensitive protease activity, PKC activity, and PLA(2) activity in the cell membrane. Pretreatment with intracellular Ca(2+) chelator (BAPTA-AM), PKCalpha inhibitor (Go6976), cPLA(2) inhibitor (AACOCF(3)), and pertussis toxin prevented t-buOOH-stimulated PLA(2) activity. Immunoblot studies with aprotinin, cPLA(2), PKCalpha, and Gialpha antibodies revealed their presence in the endothelial membrane. Immunoblot studies of the cell membrane isolated from t-buOOH-stimulated cells with cPLA(2) and PKCalpha antibodies elicited an apparent increase in their immunoreactive protein profiles along with an additional 47-kDa immunoreactive fragment in the membrane. t-buOOH caused Gialpha phosphorylation in the membrane and pretreatment with Go6976 prevented the phosphorylation. Overall, these results suggest that t-buOOH stimulates an aprotinin-sensitive protease activity that proteolytically activates PKCalpha and that subsequently phosphorylates a pertussis toxin-sensitive protein, resulting in the stimulation of cPLA(2) activity in the cell membrane.  相似文献   
4.
Because day-to-day food intake varies, we tested the hypothesis that ad libitum food intake and energy expenditure show corrective responses over periods of 1 to 10 days in healthy young women. Food intake and accelerometry measurements were collected daily for 17 days in 15 young women. Total daily energy expenditure (TDEE) using doubly labeled water was also measured. The daily deviations in macronutrient and energy intake and energy expenditure from the average values were compared with the deviations observed over succeeding intervals to estimate the corrective responses. The intraindividual coefficients of variation for energy intake averaged ±25%, ranging from 16% to 34%. TDEE had a coefficient of variation of 8.3%, and accelerometry had a coefficient of variation of 8.4% (range=4.6% to 16.4%). Energy expenditure by accelerometry (2,087±191 kcal/day) was not significantly different from TDEE (2,128±177 kcal/day), but reported daily energy intake was 20.4% lower (1,693±276 kcal/day). There were significant corrective responses in energy from fat and total energy intake. This occurred from Days 3 to 6, with a peak at Day 5 that disappeared when data were randomized within each subject. Human beings show corrective responses to deviations from average energy and macronutrient intakes with a lag time of 3 to 6 days, but not 1 to 2 days. These corrective responses are likely to play a role in bringing about weight stability.  相似文献   
5.
Self-controlled hyperthermia is a non-invasive technique used to kill or destroy cancer cells while preserving normal surrounding tissues. We have explored bulk magnetic Ni-Si and Ni-Al alloys as a potential thermoseeds. The structural, magnetic and magnetocaloric properties of the samples were investigated, including saturation magnetisation, Curie temperature (TC), and magnetic and thermal hysteresis, using room temperature X-ray diffraction and magnetometry. The annealing time, temperature and the effects of homogenising the thermoseeds were studied to determine the functional hyperthermia applications. The bulk Ni-Si and Ni-Al binary alloys have Curie temperatures in the desired range, 316?K–319?K (43?°C–46?°C), which is suitable for magnetic hyperthermia applications. We have found that TC strictly follows a linear trend with doping concentration over a wide range of temperature. The magnetic ordering temperature and the magnetic properties can be controlled through substitution in these binary alloys.  相似文献   
6.
The preterm very low birth weight infants are at high risk of developing neurodevelopmental delay despite little or no medical complications at the time of birth. The care and interventions of such infants have an impact on the pre-existing risk. The Developmental Care Interventions (DCI) are the range of treatment strategies aiming to alleviate the risk thereby improving neuro-developmental outcomes. The objective of this review is to appraise the range of such interventions for preterm very low birth weight infants reported in the literature. This review will help clinicians to adopt developmental intervention strategy to improve the neuro-developmental outcomes of their NICU graduates.  相似文献   
7.
Coconut coir (Cocos nucifera L.), particle size 300–850 μm, has been identified as an adsorbent for safranin-O dye removal from aqueous solution. Bioadsorption efficiency is improved by modifying untreated coconut coir (UCC) with 1 N phosphoric acid (PCC) and 1 N sulphuric acid (SCC). The acid treatment enhances the surface area of adsorbents and accelerates more dye uptake. The adsorption process is optimized by varying the physicochemical conditions like initial pH, adsorbent amount, contact time, initial dye concentration, and temperatures. The adsorption process's optimum pH is 4, 6, and 6, respectively, using UCC, PCC, and SCC adsorbents.In contrast, more than 98% of dye removal has been observed at the lower concentration of dyes up to 200 mg/L at 303 K. Maximum dye removal is possible at 75 mg/L of dye concentration. UCC, PCC, and SCC adsorbents’ adsorption capacity is 80.32 mg/g, 96.81 mg/g, and 89.53 mg/g, respectively, at 303 K temperature. Langmuir and Tempkin model and the pseudo-second-order model are the best-fitted models for isotherm and kinetic study. Thermodynamic parameters indicate the adsorption process is viable, spontaneous, exothermic. 75% glacial acetic acid is the most potent solvent for safranin-O dye extraction from dye loaded biomass. The functional groups and different interactions are identified to establish the adsorption mechanism. The PCC adsorbent has been used for scale-up design. The multiple polynomial regression (MPR) successfully predicts the dye removal efficiency for individual adsorbents. The modeling of the Genetic Algorithm has also been done successfully.  相似文献   
8.
Paraganglioma is a rare tumor in head and neck region. A 35 years male presented with huge swelling of tonsillar region occupying a large portion of oropharynx. Tumor had been dissected out transorally. HPE showed extra-adrenal paraganglioma. It is being reported because of its rare clinical presentation and unusual surgical approach.  相似文献   
9.
We describe a patient with blunt traumatic chest injury in whom three-dimensional transthoracic echocardiography (3DTTE) confirmed the findings of a flail anterior tricuspid valve leaflet and ruptured anterior papillary muscle seen on two-dimensional transthoracic echocardiography, and in addition identified multiple chordae tendinae rupture of the posterior leaflet. Open heart surgery confirmed the findings. The emerging role of 3DTTE in defining the true extent of traumatic tricuspid valvular injury is highlighted .  相似文献   
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