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   1587篇
  免费   145篇
  国内免费   60篇
耳鼻咽喉   6篇
儿科学   84篇
妇产科学   32篇
基础医学   249篇
口腔科学   29篇
临床医学   191篇
内科学   368篇
皮肤病学   46篇
神经病学   70篇
特种医学   101篇
外科学   193篇
综合类   28篇
预防医学   103篇
眼科学   10篇
药学   174篇
中国医学   9篇
肿瘤学   99篇
  2022年   13篇
  2021年   15篇
  2019年   13篇
  2018年   20篇
  2016年   22篇
  2015年   21篇
  2014年   48篇
  2013年   50篇
  2012年   40篇
  2011年   51篇
  2010年   49篇
  2009年   49篇
  2008年   71篇
  2007年   93篇
  2006年   51篇
  2005年   44篇
  2004年   51篇
  2003年   45篇
  2002年   45篇
  2001年   52篇
  2000年   40篇
  1999年   50篇
  1998年   42篇
  1997年   49篇
  1996年   31篇
  1995年   38篇
  1994年   41篇
  1993年   27篇
  1992年   31篇
  1991年   33篇
  1990年   34篇
  1989年   42篇
  1988年   44篇
  1987年   32篇
  1986年   32篇
  1985年   45篇
  1984年   34篇
  1983年   31篇
  1982年   23篇
  1981年   24篇
  1980年   20篇
  1979年   21篇
  1978年   31篇
  1977年   22篇
  1976年   19篇
  1975年   17篇
  1974年   13篇
  1973年   10篇
  1972年   14篇
  1970年   12篇
排序方式: 共有1792条查询结果,搜索用时 15 毫秒
101.
A 54-year-old man with a unilocular hydatid cyst within the infero-posterior angle of the orbit and a 6-year-old male child with a unilocular hydatid cyst within the supero-medial angle of the orbit are presented. The retrobulbar cysts were diagnosed with computed tomography and ultrasonography and were treated after serologic confirmation.  相似文献   
102.
Childhood tuberculosis is perceived by many as a disease of the past. Experience in a children's hospital serving a deprived population suggested that tuberculosis and other mycobacterial infections were not declining in clinical practice. Fifty three tuberculous and 11 atypical mycobacterial infections were identified between 1978 and 1992. There was no decline in tuberculosis and nine of the 11 atypical infections occurred in the last five years. Altogether 40% of cases of tuberculosis were in non-Asian children; 32% had arrived in the UK or visited family overseas in the previous year; and 38% had a history of tuberculosis contact, usually a close adult relative. Nationally, the previous decline in tuberculosis in all ages has reversed. In the local health districts in London's east end, childhood tuberculosis has also stopped declining and seems to be increasing. It is regrettable that BCG vaccination has been abolished by some districts in the UK, against current recommendations. Childhood tuberculosis is still common in the practice described here, including among children who do not fall into conventionally recognised high risk groups. Inner city dwellers and junior doctors are both highly mobile populations, adding to the risk that paediatricians, particularly those in training, may encounter tuberculosis with little or no previous experience of the condition.  相似文献   
103.
This paper explores the role of milk-based formulae in achieving four aspects of nutritional health in infants and toddlers: in the suckling, to mimic the amino acid metabolism and the faecal flora of a breast-fed baby; in the weanling, to achieve adequate protein intakes in later infancy and beyond and to achieve satisfactory haemoglobin concentrations in the early toddler years. Milk-based formulae have two roles in infant nutrition: as so-called breast milk substitutes and as a safety net during the weaning period; the latter role may be the more important.  相似文献   
104.
One hundred and twenty eight Brazilian children with lymphoblastic leukaemia were intensively treated with a Berlin-Frankfurt-Munich based protocol. More children had a white cell count above 50 x 10(9)/l (31%) then observed in developed countries. After a median follow up of 31 months (11-58 months), the estimated probability of relapse free survival was 41% (7%) for the whole group. After adjustment in the Cox's multivariate model, malnutrition was the most significant adverse factor affecting duration of complete remission. Age above 8 years and high peripheral white cell count were also significant adverse factors. Among the nutritional indices, the height for age and weight for age z scores were both significant, whether the cut off points of z-2 or z = -1.28 were chosen to define malnutrition. A strong statistical association between the two indices was found; the contribution of height for age z score to the prediction of relapse free survival was more significant. Children with height for age z score < -2 had a relapse risk of 8.2 (95% confidence interval 3.1 to 21.9) relative to children with z score > -2. The results of this study suggest that socioeconomic and nutritional factors should be considered in the prognostic evaluation of children with leukaemia in developing countries.  相似文献   
105.
Summary: The effect of prophylactic antifungal drugs on oropharyngeal and anterior nares fungal colonization was studied in 20 patients receiving nystatin and 19 patients receiving ketoconazole. Surveillance cultures were obtained weekly for a mean of 27.1 ± 4.8 days in the nystatin group and 44.0 ±6.7 days in the ketoconazole group. Initially, 63.2% of nystatin patients and 77.8% of ketoconazole patients had yeasts in their oropharynx. Neither drug eliminated oropharyngeal yeast colonization; by the end of the first four weeks of surveillance, 66.7% of the nystatin group and 63.6% of the ketoconazole group still had yeasts in the oropharynx. However, both drugs caused a reduction in the quantity of yeasts grown on successive cultures. Filamentous fungi were isolated in baseline cultures in 42.1% of the nystatin patients and 33.3% of the ketoconazole patients. Prophylaxis did not appear to alter carriage of filamentous fungi in the upper airways. Pathogenic filamentous fungi were only rarely isolated, and this rate did not increase with prophylaxis. Resistance to polyene antifungals (nystatin, amphotericin B) or to ketoconazole did not occur as a result of prophylaxis. Zusammenfassung: Untersuchung über die Pilzflora im Oropharynx und im vorderen Nasenraum unter dem Einfluß einer prophylaktischen antimykotischen Behandlung. 20 Patienten erhielten Nystatin und 19 Patienten Ketoconazol. Wöchentliche Kontrollkulturen wurden in der Nystatin-Gruppe über einen durchschnittlichen Zeitraum von 27,1 ± 4,8 Tagen und in der Ketoconazol-Gruppe über 44,0 ± 6,7 Tage durchgeführt. Zu Beginn der Untersuchung hatten 63,2% der Nystatin-Patienten und 77,8% der Ketoconazol-Patienten Hefen im Oropharynx. Keines der beiden Antimykotika eliminierte die oropharyngeale Hefebesiedlung. Nach 4wöchiger Beobachtung wurden Hefen in der Nystatin-Gruppe bei 76,7% und in der Ketoconazol-Gruppe bei 63,6% im Oropharynx festgestellt. Durch beide Antimykotika wurde jedoch eine Verringerung der kulturell nachweisbaren Hefemengen hervorgerufen. Schimmelpilze fanden sich zu Beginn der Untersuchung bei 42,1% der Nystatin-Patienten und bei 33,3% der Ketoconazol-Patienten. Unter der prophylaktischen Behandlung war keine Verringerung des Vorkommens derartiger Pilze in den oberen Luftwegen feststellbar. Pathogene Schimmelpilze wurden nur sehr selten isoliert und das Vorkommen dieser Pilze stieg unter der prophylaktischen Behandlung nicht an. Eine Resistenz gegenüber Polyen-Antimykotika (Nystatin, Amphotericin B) oder Ketoconazol trat unter der prophylaktischen Behandlung nicht auf.  相似文献   
106.
Septic arthritis in the elderly   总被引:3,自引:0,他引:3  
The clinical and microbiologic features of septic arthritis in 23 elderly patients are reviewed. Fifteen patients had pre-existing joint diseases, predominantly osteoarthritis and rheumatoid arthritis. Eight patients had underlying systemic illnesses, and eight patients were receiving systemic corticosteroid therapy prior to the development of septic arthritis. The knee was the joint most commonly infected. Although Staphylococcus aureus was the major pathogen (52.2 per cent of patients), enteric gram-negative bacilli were found in seven of 23 patients (30.4 per cent). Five patients died (21.7 per cent mortality), two as a result of their infection and three of nosocomial Pseudomonas sepsis. Eight of the 18 survivors (44.4 per cent) developed osteomyelitis in the contiguous bone. Return of joint function was slow in all patients. Septic arthritis in the elderly is difficult to treat and has a poor outcome, possibly because pre-existing joint disease is very common and enteric gram-negative bacilli are often the causative organisms.  相似文献   
107.
HPLC测定益肤霜中红霉素和地塞米松的含量   总被引:5,自引:0,他引:5  
采用HPLC测定益肤霜中红霉素和地塞米松的含量,控制制剂的质量。色谱条件:固定相为Kromasil C18柱;流动相为乙腈-0.2mol/L醋酸铵-水,流速0.8ml/min;检测波长215nm。以c对峰面积A作直线回归,红霉素在1.5-24g/L地塞米松在20-300mg/L的范围内,其浓度与峰面积呈直线关系。红霉素回收率为99.69%;地塞米松的回收率为100.28%。本法操作简便,结果准确,  相似文献   
108.
109.
110.
These studies were designed to determine whether the intestinal phase of gastric acid secretion is accompanied by an increase in serum gastrin concentration. Seven dogs with a gastric fistula and a duodenal fistula prepared so as to allow perfusion into the duodenum without reflux into the stomach were used. Gastric secretion and blood samples for serum gastrin determination were collected during intestinal perfusion with either 0.15 M NaCl or 5% liver extract at 200 ml hr(-1) for 2 hr. The mean +/- SE gastric acid secretory response during the second hour of perfusion with 0.15 M NaCl was 3.1 +/- 1.0% of the maximal acid output (MAO) to histamine, significantly (P less than 0.05) greater than the control value with no intestinal perfusion (0.18 +/- 0.07%). The mean +/- SE response during the second hour of perfusion with 5% liver extract was 7.4 +/- 2.2% of MAO, significantly (P less than 0.05) greater than both control and NaCl perfusion values. There was no significant change in peripheral serum gastrin concentration during the response to perfusion with either NaCl or liver extract. We conclude that, under the conditions of the present study, the intestinal phase of gastric acid secretion was not accompanied by an increase in serum gastrin concentration.  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