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   5126篇
  免费   330篇
  国内免费   20篇
耳鼻咽喉   72篇
儿科学   170篇
妇产科学   109篇
基础医学   727篇
口腔科学   431篇
临床医学   379篇
内科学   1028篇
皮肤病学   101篇
神经病学   293篇
特种医学   251篇
外国民族医学   1篇
外科学   618篇
综合类   82篇
预防医学   598篇
眼科学   61篇
药学   331篇
中国医学   55篇
肿瘤学   169篇
  2023年   44篇
  2022年   109篇
  2021年   179篇
  2020年   108篇
  2019年   153篇
  2018年   184篇
  2017年   112篇
  2016年   144篇
  2015年   179篇
  2014年   239篇
  2013年   257篇
  2012年   386篇
  2011年   423篇
  2010年   255篇
  2009年   209篇
  2008年   300篇
  2007年   250篇
  2006年   211篇
  2005年   199篇
  2004年   172篇
  2003年   136篇
  2002年   137篇
  2001年   107篇
  2000年   86篇
  1999年   62篇
  1998年   59篇
  1997年   50篇
  1996年   43篇
  1995年   50篇
  1994年   45篇
  1993年   25篇
  1992年   45篇
  1991年   33篇
  1990年   32篇
  1989年   39篇
  1988年   38篇
  1987年   38篇
  1986年   29篇
  1985年   30篇
  1984年   28篇
  1983年   33篇
  1982年   25篇
  1981年   20篇
  1980年   24篇
  1979年   20篇
  1978年   20篇
  1976年   10篇
  1975年   10篇
  1973年   11篇
  1970年   10篇
排序方式: 共有5476条查询结果,搜索用时 15 毫秒
991.
992.
We studied the effects of chronic (4 weeks) angiotensin converting enzyme inhibition with captopril on arterial pressure (AP) and heart rate (HR) variability, as well as on cardiac baroreflex sensitivity (BRS), in aged (20 months) rats. Series of basal RR interval (RRi) and systolic AP (SAP) were studied by autoregressive spectral analysis with oscillations quantified in low (LF: 0.2-0.8 Hz) and high frequency (HF: 0.8-2.5 Hz). BRS was measured by linear regression between HR and MAP changes. Captopril did not affect the spectra of RRi or SAP in young rats. Aged rats presented a reduction in variance (time domain) and in LF and HF oscillations of RRi and SAP. Captopril induced, in aged rats, a decrease in absolute and normalized LF oscillations and in LF/HF ratio of RRi. Captopril also reduced the variance, without changing its LF or HF components of SAP. Reflex tachycardia was reduced in aged as compared to young rats (-1.1+/-0.2 versus -3.4+/-0.5 bpm/mm Hg) and captopril did not affect it. Reflex bradycardia was also reduced in aged rats (-0.7+/-0.5 versus -2.0+/-0.4 bpm/mm Hg), but captopril prevented this attenuation in aged rats (-2.3+/-0.3 versus -0.7+/-0.5 bpm/mm Hg). These data indicate that there is a reduction in HR and SAP variability during aging, suggesting impairment of cardiovascular autonomic control. Captopril was able to change the power of oscillatory components of RRi, suggesting a shift in cardiac sympatho/vagal balance toward parasympathetic predominance. In addition, blockage of ACE improved the reflex bradycardia, but not the reflex tachycardia in aged rats.  相似文献   
993.
994.
995.
Superficial fungal infections of the hair, skin and nails are a major cause of morbidity in the world. Choosing the right treatment is not always simple because of the possibility of drug interactions and side effects. The first part of the article discusses the main treatments for superficial mycoses - keratophytoses, dermatophytosis, candidiasis, with a practical approach to the most commonly-used topical and systemic drugs , referring also to their dosage and duration of use. Promising new, antifungal therapeutic alternatives are also highlighted, as well as available options on the Brazilian and world markets.  相似文献   
996.
Superficial fungal infections of the hair, skin and nails are a major cause of morbidity in the world. Choosing the right treatment is not always simple because of the possibility of drug interactions and side effects. The first part of the article discusses the main treatments for superficial mycoses - keratophytoses, dermatophytosis, candidiasis, with a practical approach to the most commonly-used topical and systemic drugs , referring also to their dosage and duration of use. Promising new, antifungal therapeutic alternatives are also highlighted, as well as available options on the Brazilian and world markets.  相似文献   
997.
The chondroid syringoma is a rare benign tumor, also called mixed cutaneous tumor by the presence of epithelial and mesenchymal components, consisting of sweat elements in cartilaginous, collagenous, myxoid or osseous stroma, among others. It mainly affects middle-aged men and is characterized by asymptomatic and slowgrowing, dermal or subcutaneous nodules. The most common locations are the head and neck. It is rare on the extremities. There are reports of malignant variants predominantly in women, located on the extremities. We report a case of a female patient with a lesion on the toe, with excellent outcome after surgical treatment.  相似文献   
998.
The use of cochlear implant (CI) in children enables the development of listening and communication skills, allowing the child's progress in school and to be able to obtain, maintain and carry out an occupation. However, the progress after the CI has different results in some children, because many children are able to interact and participate in society, while others develop limited ability to communicate verbally. The need for a better understanding of CI outcomes, besides hearing and language benefits, has spurred the inclusion of quality of life measurements (QOL) to assess the impact of this technology.ObjectiveIdentify the key aspects of quality of life assessed in children with cochlear implant.MethodThrough a systematic literature review, we considered publications from the period of 2000 to 2011.ConclusionWe concluded that QOL measurements in children include several concepts and methodologies. When referring to children using CI, results showed the challenges in broadly conceptualizing which quality of life domains are important to the child and how these areas can evolve during development, considering the wide variety of instruments and aspects evaluated.  相似文献   
999.
Foot-and-mouth disease virus (FMDV) is a highly contagious pathogen that causes severe morbidity and economic losses to the livestock industry in many countries. The oral and respiratory mucosae are the main ports of entry of FMDV, so the stimulation of local immunity in these tissues may help prevent initial infection and viral spread. E. coli heat-labile enterotoxin (LT) has been described as one of the few molecules that have adjuvant activity at mucosal surfaces. The objective of this study was to evaluate the efficacy of replication-defective adenovirus 5 (Ad5) vectors encoding either of two LT-based mucosal adjuvants, LTB or LTR72. These vectored adjuvants were delivered intranasally to mice concurrent with an Ad5-FMDV vaccine (Ad5-A24) to assess their ability to augment mucosal and systemic humoral immune responses to Ad5-A24 and protection against FMDV. Mice receiving Ad5-A24 plus Ad5-LTR72 had higher levels of mucosal and systemic neutralizing antibodies than those receiving Ad5-A24 alone or Ad5-A24 plus Ad5-LTB. The vaccine plus Ad5-LTR72 group also demonstrated 100% survival after intradermal challenge with a lethal dose of homologous FMDV serotype A24. These results suggest that Ad5-LTR72 could be used as an important tool to enhance mucosal and systemic immunity against FMDV and potentially other pathogens with a common route of entry.  相似文献   
1000.
Hyptis pectinata L. Poit, known as ‘sambacaitá’, is used in Brazil to treat inflammatory and painful disorders. In this study, the antioxidant and orofacial antinociceptive properties of the aqueous extract of H. pectinata leaves (AEPH) were assessed using in vitro and in vivo models. Thus, AEPH reduced the 2,2‐diphenyl‐1‐picrylhydrazyl radical up to 72.10% with an EC50 of 14.56 µg/ml. It also inhibited 40.80% of the lipoperoxidation induced by 2′‐azobis (2‐amidinopropane) dihydrochloride in the thiobarbituric acid‐reactive substances assay. The orofacial antinociceptive activity was evaluated in mice pre‐treated with AEPH (100, 200 and 400 mg/kg, p.o.) and morphine (5 mg/kg, i.p.), which received afterwards formalin‐ (20 µl, 2% solution, s.c.), glutamate‐ (40 µl, 25 mM, s.c.) and capsaicin‐ (20 µl, 2.5 µg, s.c.) to induce orofacial nociception. AEPH at all doses reduced (p < 0.001) the nociceptive response in the first (43–62%) and second (47–80%) phases of the formalin test. Besides, the effect of AEPH (400 mg/kg) was not changed in the presence of naloxone (1.5 mg/kg, i.p.), an opioid antagonist. AEPH significantly inhibited mice face rubbing for capsaicin (23–69%, p < 0.05) and glutamate (48–77%, p < 0.001) at all doses. The findings suggested the AEPH has peripheral and central antinociceptive activities, which are not related to opioid receptors. Copyright © 2012 John Wiley & Sons, Ltd.  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