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   1170篇
  免费   47篇
  国内免费   24篇
耳鼻咽喉   26篇
儿科学   59篇
妇产科学   23篇
基础医学   116篇
口腔科学   59篇
临床医学   53篇
内科学   226篇
皮肤病学   12篇
神经病学   104篇
特种医学   77篇
外科学   257篇
综合类   21篇
预防医学   26篇
眼科学   48篇
药学   61篇
中国医学   10篇
肿瘤学   63篇
  2023年   9篇
  2022年   20篇
  2021年   45篇
  2020年   27篇
  2019年   35篇
  2018年   47篇
  2017年   35篇
  2016年   46篇
  2015年   39篇
  2014年   59篇
  2013年   77篇
  2012年   105篇
  2011年   104篇
  2010年   71篇
  2009年   43篇
  2008年   88篇
  2007年   81篇
  2006年   55篇
  2005年   43篇
  2004年   34篇
  2003年   32篇
  2002年   30篇
  2001年   21篇
  2000年   13篇
  1999年   10篇
  1998年   10篇
  1996年   2篇
  1995年   3篇
  1994年   2篇
  1993年   2篇
  1992年   2篇
  1990年   2篇
  1989年   4篇
  1988年   2篇
  1987年   3篇
  1986年   4篇
  1985年   2篇
  1984年   5篇
  1981年   2篇
  1980年   2篇
  1979年   5篇
  1978年   3篇
  1976年   2篇
  1974年   3篇
  1973年   1篇
  1972年   2篇
  1970年   2篇
  1969年   1篇
  1968年   1篇
  1965年   1篇
排序方式: 共有1241条查询结果,搜索用时 15 毫秒
101.
As an alternative to radioimmunoassays, a simple, highly sensitive and quick enzymeimmunoassay (EIA) for determination of cortisol in blood plasma of yaks on microtiterplates using second antibody coating technique and cortisol-horseradish peroxidase as a label has been developed. The wells of the microtiterplate were coated with affinity-purified goat IgG (antirabbit IgG) that binds the hormone specific antibody. The EIA was carried out directly in 20 microl of heat treated plasma after 1:5 dilution with PBS. The cortisol standard curve, with doses ranged from 0.4 to 100 pg/well. The sensitivity of the assay was 20 pg/ml. Cortisol standard curve in buffer showed parallelism with serially diluted yak plasma containing high endogenous cortisol. Intra- and inter-assay coefficients of variation (CV) determined using pooled plasma was found 6.58 and 11.35%, respectively. Recovery of known concentrations of added cortisol in charcoal stripped plasma was linear (r = 0.98). For biological validation of cortisol enzymeimmunoassay, the blood samples were collected from yak cows at -48 and -24h before and 0, 12, 24, 36, 48, 60, 72, 84 and 96 h after dexamethasone administration. The plasma cortisol before dexamethasone administration was significantly (P < 0.05) higher than after dexamethasone administration. The developed EIA was further validated biologically by estimating cortisol in peri-parturient cows beginning day 10 prior to calving till day 10 post-calving; the concentrations were along with the expected lines as reported in bovine. In conclusion, the EIA developed in this study is simple, highly sensitive, valid and sufficiently reliable method for estimation of cortisol directly in bovine plasma.  相似文献   
102.
Cognitive insight is a new concept. There are very few data regarding the relationship between cognitive insight and positive symptoms. The goal of the present study was to investigate the impact of acute psychosis (delusions and hallucinations) on overconfidence in judgments and self-reflectiveness of patients with schizophrenia. The Beck Cognitive Insight Scale was used to compare the cognitive insight of schizophrenia patients with (n = 93) and without (n = 45) current psychotic symptoms. Clinical symptoms and clinical insight of the patients were also assessed. The present findings suggest that both overconfidence in judgments and impaired self-reflectiveness are associated with acute psychosis. Only diminished self-reflectiveness seem to be improved following hospitalization. Although overconfidence of schizophrenia patients in their judgments was more severe in schizophrenia patients with psychotic symptoms, self-certainty of schizophrenia patients may be a relatively persistent characteristic that is also present after recovery of psychosis. Studies with larger samples involving follow up for longer periods will be valuable to understand the nature of the relationship between cognitive insight and clinical symptoms of schizophrenia.  相似文献   
103.
We report two unusual complications after a transjugular intrahepatic portosystemic shunt and a biliary stent placement, respectively. One patient with cirrhosis and portal hypertension developed obstructive jaundice secondary to compression of the right hepatic duct by a stent graft placed in the transjugular intrahepatic portosystemic shunt. In another patient, biliary stents caused obstruction of the portal vein, resulting in symptomatic portal hypertension. An awareness of these possible complications is important for early diagnosis and appropriate treatment of such complications.  相似文献   
104.
PURPOSE: To evaluate the long-term outcomes of radiologically inserted dual-lumen hemodialysis and infusion catheters in pediatric patients. MATERIALS AND METHODS: The authors retrospectively reviewed the outcomes of 114 tunneled internal jugular catheters in 71 consecutive pediatric patients between March 2003 and May 2006. Forty hemodialysis catheters were placed in 23 patients (11 girls, 12 boys), and 74 infusion catheters were placed in 48 patients (14 girls, 34 boys). The mean patient age was 11.2 years (range, 1-16 years) in the hemodialysis group and 7.86 years (range, 4 months to 16 years) in the infusion group. RESULTS: The technical success rate was 100%. The mean duration of catheter use was 84 days (range, 5-730 days) in the hemodialysis group and 58 days (range, 3-206 days) in the infusion group. Nine hemodialysis (22%) and 29 infusion (39%) catheters were electively removed. The most common reasons for catheter removal were malfunction (22%) in the hemodialysis group and completion of therapy (39%) in the infusion group. Revisions were performed at a rate of 0.6 and 0.4 per 100 catheters days in the hemodialysis and infusion groups, respectively. Total infection rates were 0.15 and 0.38 episodes per 100 catheter days in hemodialysis and infusion catheters, respectively. Mean primary device service intervals were 86 and 60 days for hemodialysis and infusion catheters, respectively, with total access site service intervals of 140 and 71 days. CONCLUSION: Radiologically placed tunneled internal jugular catheters appear to be safe and effective, with very low complication rates for both hemodialysis and long-term infusion therapies. Higher infection rates were seen in patients with cancer.  相似文献   
105.
106.
Objective: The aim of this study was to critically review the literature in order to determine if Theory of Mind (ToM) impairment can be considered a trait‐marker for schizophrenia spectrum disorders and bipolar disorder (BD). Method: After a thorough literature search, we reviewed the empirical studies investigating ToM impairments in remitted schizophrenia patients, first episode patients, subjects at high‐risk (HR) for psychosis and first‐degree relatives of schizophrenia patients. Studies investigating ToM impairment in other schizophrenia spectrum conditions, affective psychosis and BD were also reviewed. Results: ToM abnormalities exist at onset and continue throughout the course of schizophrenia, persist into remission, and while less severe, are apparent in HR populations. Mentalizing impairments are also observed in other forms of psychotic illness and BD. Conclusion: Mentalizing impairment in schizophrenia spectrum disorders and BD might reflect underlying general cognitive deficits and residual symptom expression, rather than representing a specific trait‐marker.  相似文献   
107.
108.
109.
East district of Sikkim has been considered as non-endemic for lymphatic filariasis (LF). However, a LF survey conducted during 2008 revealed microfilaria rate (mf rate) of 1.2%. The LF survey was carried out in 15 randomly selected villages and urban localities of East Sikkim. Out of 3,428 night blood smears collected and examined, 42 were found positive for Wuchereria bancrofti. Microfilaria (mf) carriers were detected from 5 surveyed villages and 5 urban localities of Singtam and Rangpoo with mf rate ranging from 0.5% to 4.2%. The mean mf density was 5.4 per 20cmm3 blood. All mf carriers were residents of east district, Sikkim except two persons who were from Bihar. The detection of microfilaria in young children who had never moved from the area indicates probable indigenous transmission. Out of 15 surveyed areas LF disease was found in 11 areas with prevalence ranging from 0.4% to 7.0%.(Disease rate was 1.6%) (1.7% for Males & 1.4% for females). One local individual was found with lymphoedema and also mf positive. Vector density ranged from 70 to 435 per ten-man-hours, sufficient for transmission of LF. 712 female Cx. quinquefasciatus were dissected to detect the filarial infection and none was found positive. The present survey findings indicate endemicity of filariasis in East district of Sikkim.  相似文献   
110.
The authors aimed to investigate cognitive performance of first-degree relatives of probands with bipolar disorder (BD). They hypothesized that the relatives of BD patients would have impaired performance on cognitive tests of frontal-executive functions. A neuropsychological battery was administered to 34 first-degree relatives of BD probands and 25 control subjects. Relatives showed significant impairment in verbal working memory and executive function. Verbal memory and psychomotor performances of relatives were not different from control subjects. One particular component of executive function, cognitive flexibility, was associated with family history of mood episodes with psychotic features. Verbal working memory and executive function deficits may be useful endophenotypic markers of genetic vulnerability to BD.  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