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   7062篇
  免费   461篇
  国内免费   58篇
耳鼻咽喉   41篇
儿科学   259篇
妇产科学   138篇
基础医学   1058篇
口腔科学   286篇
临床医学   567篇
内科学   1817篇
皮肤病学   156篇
神经病学   674篇
特种医学   172篇
外科学   729篇
综合类   10篇
一般理论   1篇
预防医学   349篇
眼科学   29篇
药学   510篇
中国医学   5篇
肿瘤学   780篇
  2023年   62篇
  2022年   152篇
  2021年   204篇
  2020年   129篇
  2019年   161篇
  2018年   197篇
  2017年   127篇
  2016年   174篇
  2015年   192篇
  2014年   270篇
  2013年   346篇
  2012年   530篇
  2011年   494篇
  2010年   293篇
  2009年   263篇
  2008年   467篇
  2007年   464篇
  2006年   430篇
  2005年   439篇
  2004年   372篇
  2003年   363篇
  2002年   364篇
  2001年   82篇
  2000年   65篇
  1999年   77篇
  1998年   76篇
  1997年   64篇
  1996年   50篇
  1995年   52篇
  1994年   34篇
  1993年   25篇
  1992年   44篇
  1991年   40篇
  1990年   40篇
  1989年   40篇
  1988年   32篇
  1987年   20篇
  1986年   35篇
  1985年   29篇
  1984年   28篇
  1983年   24篇
  1982年   22篇
  1981年   17篇
  1980年   14篇
  1979年   24篇
  1978年   14篇
  1970年   13篇
  1969年   13篇
  1967年   15篇
  1966年   16篇
排序方式: 共有7581条查询结果,搜索用时 31 毫秒
991.
Hydrogen sulfide (H(2)S) is described as a mediator of diverse biological effects, and is known to produce irritation and injury in the lung following inhalation. Recently, H(2)S has been found to cause contraction in the rat urinary bladder via a neurogenic mechanism. Here, we studied whether sodium hydrogen sulfide (NaHS), used as donor of H(2)S, produces responses mediated by sensory nerve activation in the guinea-pig airways. NaHS evoked an increase in neuropeptide release in the airways that was significantly attenuated by capsaicin desensitization and by the transient receptor potential vanilloid 1 (TRPV1) antagonist capsazepine. In addition, NaHS caused an atropine-resistant contraction of isolated airways, which was completely prevented by capsaicin desensitization. Furthermore, NaHS-induced contraction was reduced by TRPV1 antagonism (ruthenium red, capsazepine and SB366791), and was abolished by pretreatment with the combination of tachykinin NK(1) (SR140333) and NK(2) (SR48968) receptor antagonists. In anesthetized guinea-pigs, intratracheal instillation of NaHS increased the total lung resistance and airway plasma protein extravasation. These two effects were reduced by TRPV1 antagonism (capsazepine) and tachykinin receptors (SR140333 and SR48968) blockade. Our results provide the first pharmacological evidence that H(2)S provokes tachykinin-mediated neurogenic inflammatory responses in guinea-pig airways, and that this effect is mediated by stimulation of TRPV1 receptors on sensory nerves endings. This novel mechanism may contribute to the irritative action of H(2)S in the respiratory system.  相似文献   
992.
Inflammation plays a pivotal role in the pathogenesis of atherosclerosis and its complications. In particular, atherosclerosis is an active process and the inflammatory component appears to be particularly correlated with the development of acute coronary syndromes (ACS). Accumulating data demonstrate that in ACS, elevated levels of circulating inflammatory markers, such as C-reactive protein, predict an unfavorable cardiovascular outcome. A better knowledge of the molecular and cellular mechanisms of inflammation might not only further improve prognostic stratification but also allow us to identify novel therapeutic targets. The present review summarizes the mechanisms of the inflammatory response in ACS, its clinical implications, and the potential treatment strategies to contrast this phenomenon.  相似文献   
993.
994.
BACKGROUND: Palpitations are a common symptom that sometimes results from a substantial cardiac arrhythmia. A 24-hour Holter monitoring is usually used, but the yield of this instrument is low in patients whose symptoms occur infrequently. The aim of this study was to compare the diagnostic yield and the cost-effectiveness of transtelephonic event recorder (TER) with those of Holter monitoring in patients with intermittent palpitations. METHODS: Three hundred and ten patients with intermittent palpitations were allocated to the study and randomly assigned to receive a TER or 24-hour Holter monitoring. TER was given to patients until recording was obtained while symptoms occurred or was used at most for 7 days. At enrollment, a basal trace was recorded. Patients with palpitations recorded the one lead ECG trace and sent it by phone (fixed or mobile) to the telemedicine call center where a trained nurse compared the trace with the basal one and checked the patient's symptoms. The cardiologist reported "on-line" all the traces sent in the presence of an arrhythmic event and "stored and forwarded" all the other traces. Standard methods were used for Holter recording and reading. RESULTS: Patients with palpitations during the examination were 119 (76.8%) in the group of TER and 74 (47.8%) in the Holter group (p < 0.000) with an efficacy increase of 29% for TER. In symptomatic patients there were no differences between the two groups about the presence or absence of arrhythmias checked in the ECG traces; the time necessary to make a presence/absence diagnosis of arrhythmias was 2.97 +/- 2.74 days with the event recorder. The total cost of 155 tests made with Holter was altogether 9605.35 Euro (costs per test 61.97 Euro), while the one of TER was 6019.2 Euro (cost par test 38.83 Euro). The cost-effectiveness analysis was 129.80 Euro for Holter and 50.57 Euro for TER, with a saving of 79.23 Euro for every diagnosis made. CONCLUSIONS: TER allows to detect intermittent palpitations in real time; it is more useful and effective than Holter; moreover this effectiveness was also confirmed by the cost analysis in which TER resulted less expensive.  相似文献   
995.
The study focuses on parents' psychological implications caused by the treatment of their children suffering from tumor. It investigates some specific mothers' resource factors such as their strategies of coping and the perception of their own family functioning in terms of cohesion and adaptability. The study was performed with 34 mothers of children suffering from acute lymphoblastic leukemia (ALL), during the treatment phase. The used tools were the Coping Orientation to Problem Experienced-New Italian Version, to investigate coping strategies, and the Family Adaptability and Cohesion Evaluation Scale-III, to analyze both real and ideal perception of family functioning. The data related to coping, show how the involved mothers tend to mainly use the strategies of positive aptitude, orientation toward problem and social support (F = 99.88, df = 4, P < .01). The family functioning, in terms of adaptability, is described as chaotic relating to both the real (χ(2) = 13.29, df = 3, P = .004) and ideal (χ(2) = 11.52, df = 2, P = .003) family, whereas in terms of cohesion, it is perceived as chiefly disengaged in the real family (χ(2) = 12.3, df = 3, P = .006) and as enmeshed in the ideal one (χ(2) = 12.58, df = 3, P = .006). Statistically positive correlations were only detected between adaptability and avoidance (r = 0.49, P < .01); adaptability and orientation toward problem (r = 0.36, P < .05); and adaptability and transcendent orientation (r = -0.04, P < .05). Despite the critical situation, the mothers have shown optimistic view, care for problem management and capability to ask for help. These coping strategies allow the therapeutic alliance between families and health care workers, so useful for the quality of childcare.  相似文献   
996.
997.
Iron supplementation for women of reproductive age is a main part of an interdisciplinary strategy recommended for the control and prevention of iron deficiency and the treatment of mild-to-moderate iron-deficiency anaemia. This systematic review reports the findings from a meta-synthesis of qualitative data concerning the experiences and perceptions of iron supplementation among women of reproductive age and health service providers worldwide. Qualitative systematic review methods were used to conduct a search of published literature, define inclusion and exclusion criteria, appraise quality of studies and extract data on the use of iron supplementation among women of reproductive age. Coding, thematic analysis, reciprocal translation and line of argument synthesis were used to synthesize data. Twelve studies spanning 17 countries met inclusion criteria and were included in the analysis. Seven domains emerged from the review: cultural norms and societal values including explanatory models and medical pluralism; political and socio-economic circumstances; education and communication; social organization and social relationships; health care access and supplement supply; food and nutrition availability; and adherence. In addition, 16 sub-domains are highlighted. Connecting review findings to a conceptual framework of social determinants of health highlights salient issues that policy makers must consider when adapting global iron supplementation recommendations to the local context.  相似文献   
998.
999.
Traumatic intracranial pial arteriovenous fistulae are infrequent lesions. Their cardinal signs have been related to mass effect and hemorrhage, but their clinical manifestations due to venous retrograde flow into ophthalmic veins has never been described. This phenomenon is usually seen in dural arteriovenous fistula draining to the cavernous sinus or carotid-cavernous sinus fistula.A traumatic intracranial pial arteriovenous fistula arising from the supraclinoid internal carotid artery in a young patient was revealed by aggressive behavior and ophthalmologic manifestations. The endovascular management included the use of coils, stent, and ethylene-vinyl alcohol with transient balloon occlusion of the parent vessel.  相似文献   
1000.
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