首页 | 官方网站   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   31567篇
  免费   3228篇
  国内免费   117篇
医药卫生   34912篇
  2024年   35篇
  2023年   378篇
  2022年   411篇
  2021年   1260篇
  2020年   911篇
  2019年   1375篇
  2018年   1476篇
  2017年   1125篇
  2016年   1159篇
  2015年   1188篇
  2014年   1523篇
  2013年   1955篇
  2012年   2650篇
  2011年   2512篇
  2010年   1441篇
  2009年   1247篇
  2008年   2001篇
  2007年   1894篇
  2006年   1723篇
  2005年   1601篇
  2004年   1478篇
  2003年   1293篇
  2002年   1197篇
  2001年   232篇
  2000年   201篇
  1999年   230篇
  1998年   265篇
  1997年   205篇
  1996年   162篇
  1995年   157篇
  1994年   137篇
  1993年   112篇
  1992年   87篇
  1991年   92篇
  1990年   90篇
  1989年   76篇
  1988年   67篇
  1987年   49篇
  1986年   68篇
  1985年   56篇
  1984年   62篇
  1983年   64篇
  1982年   69篇
  1981年   73篇
  1980年   42篇
  1978年   37篇
  1977年   42篇
  1976年   51篇
  1975年   37篇
  1974年   40篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
OBJECTIVE: The literature on the impact of thyroid abnormalities on pregnancy and the postpartum has expanded rapidly over the last two decades. The objective of the present study was to determine the level of knowledge of endocrinologists, obstetrician/gynecologists, internists, and family physicians in regard to thyroid disease and pregnancy. DESIGN: A 16-item questionnaire on issues related to thyroid disease and pregnancy was developed. Endocrinologists (n = 116), obstetrician/gynecologists (n = 81), internists (n = 109), and family physicians (n = 99) were asked to complete the questionnaire. Physician self-report of confidence regarding degree of knowledge was obtained through completion of a seven-point Likert scale. MAIN OUTCOME: The percentage of questions answered correctly by all physicians was 63%. Endocrinologists had the highest correct response rate (77%), followed by obstetrician/gynecologists. Hierarchical regression analysis revealed that medical specialty, years of training, confidence level, and whether or not the physician treated pregnant women were significantly related to the overall score. CONCLUSIONS: The present study demonstrates a suboptimal level of knowledge regarding thyroid disease and pregnancy among physicians in four specialties. A comprehensive physician education program is needed.  相似文献   
102.
103.
Propriospinal myoclonus (PSM) is a rare movement disorder characterized by involuntary spinal-generated muscular jerks that spread rostrally and caudally to other spinally innervated muscles. Most patients have no clear etiology, and conventional MRI of the spinal cord is generally normal. Here we report the use of magnetic resonance diffusion tensor imaging (DTI) and fiber tracking to detect tract-specific abnormalities in a patient with propriospinal myoclonus. As the patient had the fragile-X premutation and antithyroid antibodies, spinal cord DTI abnormalities may be related to these conditions. Tract-specific analysis may provide new insights into the pathophysiology of propriospinal myoclonus.  相似文献   
104.
The aims were to investigate: (1) experiences of physical pain in elderly patients with hip fracture; (2) if background variables, confusion, experiences of pain and distress and interventions aimed at reducing pain and distress, functional ability, pain in the ambulance, and type of fracture varied between patients with more intense physical pain and patients with less intense physical pain. The sample included 49 patients, 70 years or older, with hip fracture. Structured instruments were used to interview and observe the patients on four occasions during the hospital stay. The patients’ experiences of physical pain decreased during the hospital stay. Physical pain at rest was lower than pain with movement. Patients who scored physical pain as more intense (group B) during the visit to the hospital had significantly more unfavourable experiences in the sensory, emotional, and existential dimensions the day before discharge from the hospital compared with the patients who scored pain as less intense (group A). The patients in group B perceived the interventions as less favourable than group A. Furthermore, group B had more intense physical pain in the ambulance than the patients in the other group. More patients in group B than in group A had additional health problems.  相似文献   
105.
In this observational study, we sought to assess the usefulness of pH values from residuals in intensive care unit (ICU) patients with small-bore feeding tubes. A review of the literature demonstrated that most critically ill patients were excluded in previous studies on gastric pH testing, suggesting that pH testing in critical care is not warranted. Our results demonstrated that 21% of intestinal testing and 64% of gastric testing yielded potential misinformation to the bedside nurse with regards to possible tube location. In conclusion, pH testing for small-bore tube placement and maintenance was not deemed meaningful in our critical care unit.  相似文献   
106.
107.
We studied specimens from 50 cadavers (27 men and 23 women) to obtain anatomical data concerning the liver and its attachments. The results allowed us to develop a polyglactin perihepatic prosthesis for compression of the injured liver. The falciform ligament and a narrowing of the hepatic parenchyma at this level allow attachment of the prosthesis. Separate prostheses were designed for each lobe. Clinical use has demonstrated that our prosthesis can be used to achieve effective control of haemorrhage and bile leakage.
Etude anatomique du foie. Développement d'une prothèse péri-hépatique
Résumé Sur une série de 50 pièces anatomiques d'adultes (27 hommes, 23 femmes), l'étude morphométrique du foie, de ses attaches dorsales et leurs variations a permis la confection d'une prothèse périhépatique en polyglactine adaptable à chaque lobe et fixée grâce à des artifices anatomiques. Celle-ci assure une compression efficace du parenchyme lésé et donc une hémostase et une bilistase correctes. Le ligament falciforme et le rétrecissement du parenchyme hépatique à son niveau assurent le maintien de la prothèse. Un exemplaire a été réalisé pour chaque lobe.
  相似文献   
108.
109.
Recent Advances in Elucidating Niemann-Pick C Disease   总被引:3,自引:0,他引:3  
Lysosomal sequestration of endocytosed LDL-derived cholesterol, premature and abnormal enrichment of cholesterol in trans Golgi cisternae and accompanying anomalies in intracellular sterol trafficking are the hallmark phenotypic features of the Niemann-Pick C (NPC) lesion. A variable severity of these alterations has been observed, with only partial correlation between clinical and biochemical phenotypes. NPC also affects the metabolism of sphingolipids, and other biochemical abnormalities have been reported. Occurrence of neurofibrillary tangles in the brain of patients with a slowly progressive course is a recent intriguing observation. Genetic heterogeneity was established by cell hybridization and linkage studies. The two complementation groups could not be distinguished from each other by clinical, cellular or biochemical criteria, suggesting that the two gene products may interact or function sequentially. The major (> 90% of patients) NPC1 gene was mapped to 18q11 and recently isolated by positional cloning. The cDNA sequence predicts a 1278-amino acid protein, with 13 to 16 possible transmembrane regions and a putative cholesterol-sensing domain. Two murine models of the disease involving the same gene are known. The murine cDNA and the npcnih mutation have been characterized. Described homologies of the NPC1 protein are in line with its putative involvement in cellular cholesterol traffic.  相似文献   
110.
We investigated the immunohistochemical localization of CD44, hyaluronate receptor, and moesin, of the ezrinradixin-moesin (ERM) family, in osteoclasts after calcitonin adminstration using confocal laser scanning microscopy and transmission electron microscopy to clarify the role of CD44 and moesin in their cytoskeletal organization and cell polarity. We also elucidated the localization of osteopontin (OPN) to confirm its possible role in cell-matrix recognition via CD44. In untreated mice, intense immunoreactivities for CD44 and moesin were detected on the basolateral plasma membrane of osteoclasts. Rhodamine-phalloidin reactivity was seen in a bandlike pattern on the region of contact between osteoclasts and bone and was also detected moderately along their basolateral plasma membrane. At 30 min after calcitonin administration, osteoclasts did not show either clear zones or ruffled borders. The bandlike reactivity of rhodamine-phalloidin in the contact region was diminished, although labeling was seen along osteoclasts. CD44 and moesin were colocalized along their plasma membranes, including the region facing the bone surface. Electron microscopic observation revealed that the microvillus processes in the contacting region with bone surface, as well as the basolateral plasma membrane, showed immunoreactivities to CD44 and moesin. At 60 min, some osteoclasts attached to bone and showed a bandlike pattern of rhodamine-phalloidin. On the other hand, OPN was localized under CD44-positive cytoplasmic processes and the clear zone of osteoclasts. These findings suggest that calcitonin effects on the cell polarity of osteoclasts and the CD44-moesin-actin filament system in osteoclasts plays an imporant role in cell polarity and cell-matrix recognition.  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-23

京公网安备 11010802026262号