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   563篇
  免费   30篇
  国内免费   3篇
耳鼻咽喉   7篇
儿科学   9篇
妇产科学   57篇
基础医学   40篇
口腔科学   18篇
临床医学   56篇
内科学   92篇
皮肤病学   7篇
神经病学   27篇
特种医学   24篇
外国民族医学   1篇
外科学   117篇
预防医学   44篇
眼科学   27篇
药学   46篇
中国医学   4篇
肿瘤学   20篇
  2023年   1篇
  2022年   11篇
  2021年   26篇
  2020年   19篇
  2019年   32篇
  2018年   35篇
  2017年   15篇
  2016年   20篇
  2015年   20篇
  2014年   22篇
  2013年   33篇
  2012年   32篇
  2011年   42篇
  2010年   26篇
  2009年   21篇
  2008年   23篇
  2007年   25篇
  2006年   32篇
  2005年   34篇
  2004年   31篇
  2003年   25篇
  2002年   19篇
  2001年   4篇
  1999年   1篇
  1998年   2篇
  1997年   2篇
  1996年   1篇
  1995年   3篇
  1994年   5篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1990年   3篇
  1989年   1篇
  1988年   1篇
  1986年   2篇
  1985年   2篇
  1984年   1篇
  1983年   1篇
  1982年   2篇
  1981年   2篇
  1979年   1篇
  1977年   1篇
  1973年   1篇
  1971年   3篇
  1970年   1篇
  1969年   1篇
  1968年   3篇
  1967年   1篇
  1965年   3篇
排序方式: 共有596条查询结果,搜索用时 31 毫秒
121.
122.
123.
Ozzoude  Miracle  Varriano  Brenda  Beaton  Derek  Ramirez  Joel  Holmes  Melissa F.  Scott  Christopher J. M.  Gao  Fuqiang  Sunderland  Kelly M.  McLaughlin  Paula  Rabin  Jennifer  Goubran  Maged  Kwan  Donna  Roberts  Angela  Bartha  Robert  Symons  Sean  Tan  Brian  Swartz  Richard H.  Abrahao  Agessandro  Saposnik  Gustavo  Masellis  Mario  Lang  Anthony E.  Marras  Connie  Zinman  Lorne  Shoesmith  Christen  Borrie  Michael  Fischer  Corinne E.  Frank  Andrew  Freedman  Morris  Montero-Odasso  Manuel  Kumar  Sanjeev  Pasternak  Stephen  Strother  Stephen C.  Pollock  Bruce G.  Rajji  Tarek K.  Seitz  Dallas  Tang-Wai  David F.  Turnbull  John  Dowlatshahi  Dar  Hassan  Ayman  Casaubon  Leanne  Mandzia  Jennifer  Sahlas  Demetrios  Breen  David P.  Grimes  David  Jog  Mandar  Steeves  Thomas D. L.  Arnott  Stephen R.  Black  Sandra E.  Finger  Elizabeth  Tartaglia  Maria Carmela 《Age (Dordrecht, Netherlands)》2022,44(3):1575-1598
GeroScience - Change in empathy is an increasingly recognised symptom of neurodegenerative diseases and contributes to caregiver burden and patient distress. Empathy impairment has been associated...  相似文献   
124.
BackgroundEosinophilic gastroenteritis (EGE) is defined by the presence of gastrointestinal symptoms, with an abnormal eosinophilic infiltrate of the intestine wall and exclusion of other causes of secondary eosinophilia. EGE has three clinical presentations, depending on the depth of eosinophilic infiltration of the bowel wall. It individualizes into three types, namely mucosal, muscular, and subserosal. Eosinophilic ascites, which is caused by edema and eosinophilic inflammation of the serosal layer of the small bowel wall, is the most uncommon presentation of EGE.Case summaryA 30-year-old Egyptian woman presented with pain in the epigastrium and diffuse abdominal distension. Past medical history comprised allergy to iron injections (for iron deficiency anemia). Clinical examination showed moderate abdominal distention (palpation) and shifting dullness (percussion) suggestive of moderate ascites; mild right pleural effusion was also suspected, but findings were otherwise unremarkable. Abdominal and pelvic examinations by ultrasound and contrast-enhanced computed tomography showed moderate ascites, mild right pleural effusion, and diffuse thickening of the antrum and small bowel loops. Endoscopy of the upper gastrointestinal tract revealed mild diffuse hyperemia of the esophagus, stomach and duodenum, with no relevant findings in the histopathology of biopsy specimens taken from these sites. Laboratory results showed eosinophilia in the peripheral blood and marked increase of eosinophils in the ascitic fluid. Treatment with corticosteroids resulted in normalization of the laboratory test results, and the ascites resolved within a week of initiation of therapy.ConclusionEosinophilic ascites, characterized by increased eosinophils in peripheral blood and ascitic fluid, showed dramatic response to steroid therapy.  相似文献   
125.
126.
127.
Toward the goal of detecting toxic elements and removing them from drinking water, we report herein the utilization of Acid Red 94 (AR94) in sensing the hazardous metal ions in water. Among the various examined metal ions (Ag+, Pb2+, K+, Mn2+, Zn2+, La3+, Hg2+, Ca2+, Cd2+, Co2+, and Ni2+), the UV-visible absorption spectra showed high selectivity and sensitivity for toxic silver and lead metal ions in an aqueous solution. The observed absorption spectral changes and the rapid color changes confirm complex formation between AR94 and both Ag+ and Pb2+ metal ions. The emission measurements showed the significant fluorescence quenching of the singlet excited state of AR94 in the presence of Ag+ and Pb2+ metal ions suggesting the formation of an irradiative dye–metal complex under the prevailing experimental conditions. In order to remove the accumulated complexes of AR94 with silver metal ions, safe and harmless mesoporous titanium dioxide was utilized efficiently in removing the complexes with adsorption capacities of 91% at 30 minutes. These findings suggest a simple, fast and efficient method for both detecting silver in water, and removing the formed AR94–metal complexes in water. In addition, AR94 is shown to be a good sensor for the presence of Ag and Pb nanoparticles, NPs, in aqueous solution. The absorption and emission spectra of AR94 showed significant changes that may be rationalized by the strong electromagnetic coupling induced by NPs plasmonic effects. These findings render AR94 a sensitive and selective sensor and a visual indicator for the qualitative and quantitative detection of silver ions, lead ions and their nanoparticles.

Toward the goal of detecting toxic elements and removing them from drinking water, we report herein the utilization of Acid Red 94 (AR94) in sensing the hazardous metal ions in water.  相似文献   
128.

Objective

The objective of this systematic review and meta-analysis was to evaluate the soft tissue changes in adult orthodontic patients who received extraction treatment in comparison to their counterparts who received nonextraction orthodontic treatment.

Methods

Electronic databases (CENTRAL–Cochrane Register of Controlled Trials, PubMed, Embase, EBESCOhost, LILACS, and Google Scholar) were searched up to March 2015. Handsearching was performed too. The selection process included controlled trials (prospective or retrospective and randomized or nonrandomized) on adult patients receiving orthodontic extraction treatment compared within the same study to a group treated without extraction. The outcomes of interest were the changes in linear and angular cephalometric measurements specific for soft tissue profile. Studies which fulfilled the selection criteria were retrieved. They were assessed for methodological quality based on a validated checklist. Studies of moderate to high quality were included.

Results

Of the nine full texts which fulfilled the selection criteria, 5 were eligible for the quantitative analysis; they scored a moderate quality. Meta-analysis showed a significant increase regarding the nasolabial angle, upper lip thickness, labrale superioris to E-Line, and labrale inferioris to E-line in the extraction group, suggesting the flattening of the profile following extraction treatment.

Conclusion

A significant retraction of the lips and an increase in the nasolabial angle are associated with extraction protocols, but the degree to which these changes are considered detrimental/beneficial to the profile could be affected by different factors. Since these finding are based on studies of moderate quality, future research with well-conducted methodologies are highly recommended.  相似文献   
129.
Objective: To evaluate the efficacy of salivary progesterone, cervical length measurement in predicting preterm birth (PTB).

Methods: Prospective observational study included 240 pregnant women with gestational age (GA) 26–34 weeks classified into two equal groups; group one are high risk for PTB (those with symptoms of uterine contractions or history of one or more spontaneous preterm delivery or second trimester abortion) and group 2 are controls.

Results: There was a highly significant difference between the two study groups regarding GA at delivery (31.3?±?3.75 in high risk versus 38.5?±?1.3 in control), cervical length measured by transvaginal ultrasound (24.7?±?8.6 in high risk versus 40.1?±?4.67 in control) and salivary progesterone level (728.9?±?222.3 in high risk versus 1099.9?±?189.4 in control; p?p value 0.035) but not in low risk group (p value 0.492). CL measurement showed a sensitivity of 71.5% with 100% specificity, 100% PPV, 69.97% NPV and accuracy of 83%, while salivary progesterone showed a sensitivity of 84% with 90% specificity, 89.8% PPV, 85.9% NPV and accuracy of 92.2%.

Conclusion: The measurement of both salivary progesterone and cervical length are good predictors for development of PTB.  相似文献   
130.
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