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   479篇
  免费   21篇
  国内免费   29篇
耳鼻咽喉   2篇
儿科学   29篇
妇产科学   62篇
基础医学   39篇
口腔科学   14篇
临床医学   38篇
内科学   81篇
皮肤病学   16篇
神经病学   12篇
特种医学   54篇
外科学   44篇
综合类   60篇
预防医学   28篇
眼科学   2篇
药学   31篇
肿瘤学   17篇
  2022年   2篇
  2021年   4篇
  2020年   1篇
  2019年   2篇
  2016年   4篇
  2015年   6篇
  2014年   11篇
  2013年   11篇
  2012年   9篇
  2011年   10篇
  2010年   19篇
  2009年   19篇
  2008年   23篇
  2007年   26篇
  2006年   36篇
  2005年   18篇
  2004年   16篇
  2003年   11篇
  2002年   11篇
  2001年   15篇
  2000年   10篇
  1999年   11篇
  1998年   32篇
  1997年   36篇
  1996年   32篇
  1995年   19篇
  1994年   13篇
  1993年   19篇
  1992年   14篇
  1991年   2篇
  1990年   6篇
  1989年   11篇
  1988年   6篇
  1987年   7篇
  1986年   4篇
  1985年   14篇
  1984年   4篇
  1983年   5篇
  1982年   6篇
  1981年   6篇
  1980年   1篇
  1978年   4篇
  1977年   2篇
  1976年   1篇
  1975年   3篇
  1973年   1篇
  1970年   2篇
  1969年   2篇
  1967年   1篇
  1966年   1篇
排序方式: 共有529条查询结果,搜索用时 15 毫秒
31.
Treatment of allergic bronchopulmonary aspergillosis (ABPA) has remained both problematic as well as controversial. Although the sheet anchor in treatment of ABPA still remains steroids, various workers have tried oral antifungals (fluconazole and itraconazole) with encouraging results. This study evaluates the effect of fluconazole or itraconazole in the treatment of ABPA patients and compares them with the patients who had received palliative therapy other than antifungals. Case records of 44 proven cases of ABPA treated at our referral service hospital during February 1998 to April 2001 were analyzed. In addition to oral and inhaled bronchodilators, 16 patients received fluconazole 150 mg OD and 13 patients itraconazole 200 mg OD for six months. Response to therapy was assessed clinically, radiologically and by spirometry every 3 months. Patients who did not receive antifungals had chronic course characterized by airway obstruction, recurrent pulmonary consolidation and obstructive defect on pulmonary function test (PFT). Patients treated with itraconazole had better control of asthma symptoms, less requirement of reliever inhalers, steroids and lesser exacerbations of asthma during follow-up even after stopping antifungal. Fluconazole group had better control of symptoms but improvement in other parameters was not statistically significant. From this study it was evident that itraconazole improved the symptoms of airway obstruction, pulmonary functions, pulmonary opacities and decreased exacerbations during follow up.Key Words: Allergic bronchopulmonary aspergillosis, Fluconazole, Itraconazole  相似文献   
32.
OBJECTIVE: Our purpose was to evaluate the association between fetal iron status and mental and psychomotor development at 5 years of age. STUDY DESIGN: We evaluated the association of fetal iron status (umbilical cord serum ferritin concentrations) with test scores of mental and psychomotor development of 278 children. Six tests were given, including full-scale intelligence quotient (FSIQ), language ability, fine- and gross-motor skills, attention, and tractability. RESULTS: Compared with children with cord ferritin in the 2 median quartiles, those in the lowest quartile scored lower on every test and had significantly worse language ability, fine-motor skills, and tractability. They were also 4.8-fold more likely to score poorly in fine-motor skills and 2.7-fold more likely to have poor tractability than children in the median quartiles. FSIQ in the highest quartile was slightly, but not significantly, lower than the median quartiles, but the odds ratio for having a FSIQ score of less than 70 for children in the highest quartile was 3.3 (95% CI 1.2-9.1). CONCLUSION: Poor iron status (low ferritin) in utero appears to be associated with diminished performance in certain mental and psychomotor tests. The reason for the association between high ferritin concentrations and low FSIQ scores is unknown.  相似文献   
33.
OBJECTIVE: To assess the effect of a change in human immunodeficiency virus (HIV) testing policy on HIV testing rates in an urban maternity clinic population. METHODS: Since 1995, our institution has provided pretest counseling and voluntary HIV testing to all pregnant women. After the 1999 Institute of Medicine recommendation of HIV testing with patient notification as a routine component of prenatal care, we conducted a prospective study to determine whether this policy would increase our HIV screening rates. The intervention incorporated HIV testing into the routine battery of tests drawn at antenatal care. Not to be tested required active refusal. The intervention group was comprised of all women receiving an initial antenatal visit in one of our eight maternity clinics between August 1, 1999, and July 30, 2000. The control group was comprised of all women presenting for prenatal care in the same clinics during the year before the intervention. RESULTS: The 3415 women in the intervention group and 3778 controls were similar with respect to most demographic and risk factors. After the intervention, HIV testing increased from 75% to 88% (P <.001). Among all women in both years of the study, women who were in the intervention group, less than 20 years of age, or who had a history of substance abuse, were more likely not to refuse testing. CONCLUSION: After implementation of a policy of routine HIV testing with active patient refusal, HIV testing rates increased among pregnant women in our large, urban obstetric clinic population.  相似文献   
34.
We tested an improved immunofluorescence assay (IFA) in detecting Giardia and Cryptosporidium from feces of asymptomatic adult cervine animals. Samples were concentrated by sucrose flotation before being stained by fluorescent monoclonal antibody and examined microscopically. The detection limit was determined as 500 G. intestinalis cysts or 200 C. parvum oocysts/g of sample. Among the 82 samples collected from adult fallow deer, Columbian black-tailed deer, and Tule elk in northern California, 3 (3.7%) contained G. intestinalis cysts, which were confirmed by a species-specific polymerase chain reaction (PCR) following immunomagnetic capture (IC) of cysts. C. parvum oocysts were detected in a total of 13 (15.9%) samples, and oocysts from 2 such samples were smaller than oocysts from the other 11 samples. C. parvum identification was also confirmed by specific IC-PCR and sequencing of the PCR product. In addition, a C. muris-like organism was detected in 2 (2.4%) samples. Findings obtained with the improved IFA confirmed that cysts/oocysts may pass unnoticed in adult cervine animals and that subclinically infected individuals could serve as potential carriers of infection for humans and other animals via contaminated feces or water. Received: 19 January 1999 / Accepted: 29 March 1999  相似文献   
35.
Accuracy of fetal echocardiography   总被引:6,自引:0,他引:6  
Benacerraf  BR; Pober  BR; Sanders  SP 《Radiology》1987,165(3):847-849
The reliability of prenatal ultrasound (US) for the detection of structural heart defects was investigated in a consecutive population of patients referred for prenatal US. Twenty-eight of 49 fetuses (57%) shown to have one or more heart defects with physical examination or autopsy were found to have congenital heart disease with prenatal US. There were 66 cardiac defects in 49 fetuses, 33 of which were entirely or partly identified (50%). Defects correctly diagnosed included hypoplasia of either ventricle, common atrioventricular canal, tetralogy of Fallot, transposition of the great vessels, and Ebstein anomaly. Defects rarely diagnosed correctly included semilunar valve stenosis, total anomalous pulmonary venous drainage, coarctation of the aorta, pulmonic atresia, atrioseptal defect, and ventricular septal defect. Many types of heart defects can be diagnosed accurately with prenatal US in a general population of patients not at high risk for congenital heart disease. Some lesions, however, were difficult to detect.  相似文献   
36.
37.
Pulmonary histiocytosis X: comparison of radiographic and CT findings   总被引:6,自引:0,他引:6  
The authors retrospectively evaluated radiographs, computed tomographic (CT) scans, and results of pulmonary function tests (when available) for 17 patients with biopsy-proved pulmonary histiocytosis X. In 11 patients, high-resolution CT was used. In 12 patients, CT demonstrated cystic air spaces, usually less than 10 mm in diameter. In three of these 12, cysts were the only abnormality, but in six others, nodules (usually less than 5 mm in diameter) were also present. Two patients had only nodules and one, only emphysema. CT showed that many lesions that appeared reticular on plain radiographs were actually cysts. CT showed no central or peripheral concentration of lesions, but it did reveal that many small nodules were distributed in the centers of secondary lobules around small airways. CT findings correlated better with the diffusing capacity (rho = -0.71) than did the plain radiographic findings (rho = -0.57). Thus, CT was better than radiography at showing the morphology and distribution of lung abnormalities.  相似文献   
38.
The immunoglobulin G subclass responses to cytomegalovirus (CMV) after red cell (RBC) transfusion were studied in 26 seropositive surgery patients and 34 transfused seropositive oncology patients. Also included as controls were 18 surgical patients who received no RBCs during surgery. None of the 78 patients studied had IgG2 to CMV before or after transfusion. The absence of a total IgG response to CMV after transfusion could not be attributed to preexisting deficiencies in one or more subclasses, because all 78 patients had similar levels of IgG1, IgG3, and IgG4 to CMV before transfusion. Discriminant analysis was used for statistical evaluation of the combined CMV subclass responses in each patient and the individual subclass responses. Individual patients responded to CMV antigens with an increase in concentration in any of the three subclasses or any combination of the subclasses, excluding IgG2. IgG subclass analysis showed that 10 of 27 patients who did not respond with at least a fourfold total IgG titer rise had a significant increase in IgG subclass antibodies to CMV. Three of 33 patients with at least a fourfold total IgG titer rise lacked a subclass response. These results suggest that the measurement of IgG subclasses may be a sensitive indicator of immune response to CMV.  相似文献   
39.
In the community, acute hypoglycaemia is commonly caused by therapies for diabetes mellitus or the excessive consumption of alcohol. Although most episodes do not require admission to hospital, little information is available on the causes and outcome of those that do. We retrospectively surveyed adult patients admitted to a large urban teaching hospital with acute hypoglycaemia in a 12-month period, identifying 56 admissions of 51 patients. Forty-one had diabetes mellitus, 33 (80%) of whom were receiving treatment with insulin. The others had hypoglycaemia induced by excessive consumption of alcohol or by deliberate self-poisoning with insulin. A history of psychiatric illness and/or chronic alcoholism was common. Neurological manifestations of hypoglycaemia were the principal reason for admission, observed on 50 occasions (89%), and 11 events (20%) had precipitated convulsions. Although many patients (59%) had received treatment for hypoglycaemia before admission, hypoglycaemia recurred in 16% of patients in hospital. Four patients (7%) died following admission, but in only one case was this the direct result of hypoglycaemia. However, within 15 months of the index hypoglycaemia event, a further six patients (11%) had died, mostly of causes unrelated to hypoglycaemia. Patients who require hospital admission for treatment of hypoglycaemia have a high incidence of neurological manifestations, a high rate of mental illness and other medical disorders, and may represent a high-risk subgroup with a poor long-term prognosis.   相似文献   
40.
目的:通过细胞形态学观察及生物学特性鉴定,建立一种经济实用的体外原代培养纯化新生鼠嗅鞘细胞的实验方法。方法:实验于2006-06在武汉理工大学完成。①阿糖胞苷(Sigma,批号w10562);胎牛血清(杭州四季青产品);胰蛋白酶(Amresco);多聚赖氨酸(Sigma);胶质纤维酸性蛋白,神经生长因子受体蛋白抗体(博士德)。②选取出生3d内的Wistar大鼠5只,乙醇浸泡后断头处死,取嗅球的最外两层,通过1.25g/L胰蛋白酶消化分离嗅鞘细胞,体外原代培养。③采用Nash差速贴壁 阿糖胞苷 胰酶法纯化嗅鞘细胞。培养18h后将未贴壁的细胞悬液转种于另一未涂层的器皿中,再培养36h,重复上述步骤移入0.1g/L多聚赖氨酸包被的塑料培养瓶中进行培养,纯化后的细胞在24h内陆续贴壁,常规培养2d,加入终浓度为2mg/L的阿糖胞苷,作用48h后,换上新的培养基,继续培养1d,弃去培养基,用无钙镁的Hanks液清洗2次,然后用1.25g/L的胰酶消化10min,待细胞突起回缩、胞体变圆时,立刻加入纯血清终止,其血清终浓度为20%,制备单细胞悬液。④倒置显微镜下观察其形态变化,苏木精-伊红染色,同时行神经生长因子受体蛋白和胶质纤维酸性蛋白免疫组化染色鉴定嗅鞘细胞,并计算嗅鞘细胞阳性百分率。结果:①活细胞形态观察:分离培养的嗅鞘细胞具有双极或多极突起,且突起细长,相互交织。②嗅鞘细胞的苏木精-伊红染色鉴定:细胞呈三角形或梭形,有长的突起,胞浆被染成粉红色,胞核呈蓝紫色,胞核内深染的为核仁,有1~3个核仁。③嗅鞘细胞的胶质纤维酸性蛋白免疫组化染色鉴定:细胞呈现棕黄色,胞核淡染,阳性细胞成网状连接,胞体多为三角形,有细长突起,阳性率91.5%。④嗅鞘细胞的P75免疫组化染色鉴定:阳性细胞呈绿色,多数细胞染色阳性,阳性率89%。结论:实验所采用的Nash差速贴壁 阿糖胞苷 胰酶法分离纯化培养嗅鞘细胞切实可行,为神经诱导修复材料的研究提供种子细胞。  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