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   1283篇
  免费   46篇
  国内免费   81篇
耳鼻咽喉   1篇
儿科学   67篇
妇产科学   9篇
基础医学   137篇
口腔科学   23篇
临床医学   221篇
内科学   294篇
皮肤病学   33篇
神经病学   27篇
特种医学   303篇
外科学   72篇
综合类   27篇
预防医学   28篇
眼科学   6篇
药学   71篇
肿瘤学   91篇
  2022年   5篇
  2021年   8篇
  2019年   12篇
  2018年   8篇
  2017年   10篇
  2016年   10篇
  2015年   18篇
  2014年   13篇
  2013年   31篇
  2012年   15篇
  2011年   20篇
  2010年   52篇
  2009年   48篇
  2008年   20篇
  2007年   58篇
  2006年   21篇
  2005年   27篇
  2004年   13篇
  2003年   15篇
  2002年   18篇
  2001年   18篇
  2000年   24篇
  1999年   25篇
  1998年   94篇
  1997年   88篇
  1996年   109篇
  1995年   84篇
  1994年   87篇
  1993年   74篇
  1992年   21篇
  1991年   30篇
  1990年   27篇
  1989年   32篇
  1988年   36篇
  1987年   27篇
  1986年   34篇
  1985年   32篇
  1984年   13篇
  1983年   21篇
  1982年   20篇
  1981年   21篇
  1980年   17篇
  1979年   4篇
  1978年   9篇
  1977年   14篇
  1976年   13篇
  1975年   7篇
  1970年   1篇
  1969年   1篇
  1966年   1篇
排序方式: 共有1410条查询结果,搜索用时 15 毫秒
11.
FL Porter  CM Wolf  J Gold  D Lotsoff  JP Miller 《Pediatrics》1997,100(4):626-632
BACKGROUND: Despite an increased awareness among clinicians regarding pain and pain management for infants undergoing surgery, pain associated with procedures performed outside the operating room may not be adequately managed. PURPOSE: To examine the beliefs and self-described behavior of physicians and nurses regarding the management of procedural pain in newborn infants. METHODS: A survey was distributed to 467 clinicians (nurses and physicians) working in 11 level II and 4 level III nurseries in a large metropolitan area. Respondents were asked to rate the painfulness of 12 common bedside nursery procedures and how often pharmacologic and nonpharmacologic (comfort) measures are currently used and should be used for those procedures. Demographic data were also collected. RESULTS: Surveys were completed by 374 clinicians (80% response rate). Physicians and nurses believe infants feel as much pain as adults and that 9 of the 12 listed procedures are moderately to very painful. Neither pharmacologic nor comfort measures are believed to be used frequently, even for the most painful procedures. Physicians and nurses believe both pharmacologic and comfort measures should be used more frequently, but nurses believe comfort measures should be used more frequently than do physicians. Beliefs about infant pain and procedural pain were related to pain management preferences. Physicians' but not nurses' ratings were associated with significant personal pain. CONCLUSIONS: Despite their beliefs that infants experience significant procedure-related pain, clinicians believe pain management for infants remains below optimal levels. Barriers to more consistent and effective pain management need to be identified and surmounted.  相似文献   
12.
13.
This report highlights the association between tuberous sclerosis and Wolff-Parkinson-White syndrome. Ten patients with concurrent diagnoses of Wolff-Parkinson-White syndrome and tuberous sclerosis were identified. Wolff-Parkinson-White syndrome presented early in life, nine cases being diagnosed in the first year. Eight of the 10 cases were male. In eight cases, the syndrome was associated with supraventricular tachycardias, and in nine with cardiac rhabdomyomata. One child died from cardiac failure secondary to obstruction of the left ventricular outflow tract by a rhabdomyoma. Five of nine survivors showed resolution of Wolff-Parkinson-White syndrome on follow up. The accessory pathway was localised in nine patients from surface electrocardiograms: six children had left sided pathways and three had right sided pathways.  相似文献   
14.
Iron-overload diseases frequently develop hepatocellular carcinoma. The genotoxic mechanism whereby iron is involved in hepatocarcinogenesis might involve an oxidative process via the intermediate production of reactive oxygen species. This was presently investigated by examining kinetics of formation and repair of DNA base lesions in primary rat hepatocyte cultures supplemented with the iron chelate, ferric nitrilotriacetate Fe-NTA (10 and 100 microM). Seven DNA base oxidation products have been identified in DNA extracts by gas chromatography- mass spectrometry, which showed a predominance of oxidized-purines (8- oxo-guanine, xanthine, fapy-adenine, 2-oxo-adenine) above oxidized pyrimidines (5-OHMe-uracil, 5-OH-uracil, 5-OH-cytosine) in control cultures. All these DNA oxidation products revealed a significant dose- dependent increase at 4 to 48 h after Fe-NTA supplementation, among which fapy-adenine showed the highest increase and 5-OH-cytosine was the least prominent. Involvement of iron in this oxidative process was established by a correlation between extent in DNA oxidation and intracellular level of toxic low molecular weight iron. DNA excision- repair activity was estimated by release of DNA oxidation products in culture medium. All the seven DNA oxidation products were detected in the medium of control cultures and showed basal repair activity. This DNA repair activity was increased in a time- and dose-dependent fashion with Fe-NTA. Oxidized-pyrimidines, among which was 5-OHMe-Uracil, were preferentially repaired, which explains the low levels detected in oxidized DNA. Since oxidized bases substantially differed from one another in terms of excision rates from cellular DNA, specific excision- repair enzymes might be involved. Our findings, however, demonstrate that even though DNA repair pathways were activated in iron-loaded hepatocyte cultures, these processes were not stimulated enough to prevent an accumulation of highly mutagenic DNA oxidative products in genomic DNA. The resulting genotoxic effect of Fe-NTA might be relevant in understanding the hepatocarcinogenic evolution of iron-overload diseases.   相似文献   
15.
Young adults living with type 1 diabetes often struggle to achieve what clinicians consider to be optimal levels of metabolic control. Despite the impact that this can have on a young person''s future risk of complications, there are relatively few studies reporting new ways of organizing or delivering care to this cohort. In this article, we explore some of the reasons why young adult diabetes care is challenging, and describe approaches to “re‐imagining” how care might be improved. The work is informed by the ‘Making Care Fit’ collaborative and by a program of research, entitled D1 Now, involving co‐design of a complex person‐centered intervention with young adults.  相似文献   
16.
17.
van Schaik  JP; Hawkins  IF  Jr 《Radiology》1985,155(3):829-830
A new technique is described for reversing the direction of the catheter tip during translumbar aortography, without the need for partial withdrawal of the catheter from the aortic lumen. The method ensures optimal delivery of contrast medium at the desired level, while avoiding the risk of retroperitoneal bleeding or dislodgement during catheter manipulation.  相似文献   
18.
19.
20.
Minactivin expression in human monocyte and macrophage populations   总被引:4,自引:0,他引:4  
Adherent monolayer cultures of human blood monocytes, peritoneal macrophages, bone marrow macrophages, and colonic mucosa macrophages were examined for their ability to produce and secrete minactivin, a specific inactivator of urokinase-type plasminogen activator. All except colonic mucosa macrophages produced and secreted appreciable amounts of minactivin, but only blood monocytes were stimulated by muramyl dipeptide (adjuvant peptide) to increase production. The minactivin from each of these populations could be shown to preferentially inhibit urokinase-type plasminogen activator and not trypsin, plasmin, or "tissue"-type plasminogen activator (HPA66). A plasminogen-activating enzyme present in monocyte cultures appeared unaffected by the presence of minactivin and could be shown to be regulated independently by dexamethasone.  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