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   600篇
  免费   41篇
  国内免费   1篇
儿科学   28篇
妇产科学   13篇
基础医学   88篇
口腔科学   7篇
临床医学   57篇
内科学   165篇
皮肤病学   9篇
神经病学   100篇
特种医学   20篇
外科学   26篇
综合类   3篇
预防医学   64篇
眼科学   11篇
药学   16篇
肿瘤学   35篇
  2024年   3篇
  2023年   8篇
  2022年   5篇
  2021年   25篇
  2020年   22篇
  2019年   31篇
  2018年   9篇
  2017年   16篇
  2016年   18篇
  2015年   18篇
  2014年   36篇
  2013年   40篇
  2012年   65篇
  2011年   61篇
  2010年   22篇
  2009年   29篇
  2008年   46篇
  2007年   34篇
  2006年   41篇
  2005年   35篇
  2004年   26篇
  2003年   22篇
  2002年   18篇
  2001年   1篇
  1999年   1篇
  1998年   4篇
  1997年   2篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1991年   1篇
排序方式: 共有642条查询结果,搜索用时 15 毫秒
1.
2.
There are few reports of positron emission tomography (PET) in juvenile parkinsonism (JP). We report on the results of (18)F-6-fluoro-L-dopa (FD) PET in a 14-year-old patient with JP of 5 years duration associated with atypical features. This is the youngest subject to be investigated to date. There was a severe asymmetric reduction in striatal FD uptake, with a rostrocaudal gradient in the putamen similar to that seen in adult-onset idiopathic parkinsonism. Extensive DNA analysis in this patient did not show mutations in the parkin gene.  相似文献   
3.
4.
When making a decision, humans often have to ‘coordinate’—reach the same conclusion—as another individual without explicitly communicating. Relatively, little is known about the neural basis for coordination. Moreover, previous fMRI investigations have supported conflicting hypotheses. One account proposes that individuals coordinate using a ‘gut feeling’ and that this is supported by insula recruitment. Another account proposes that individuals recruit strategic decision-making mechanisms in prefrontal cortex in order to coordinate. We investigate the neural basis for coordination in individuals with behavioral-variant frontotemporal dementia (bvFTD) who have limitations in social decision-making associated with disease in prefrontal cortex. We demonstrate that bvFTD are impaired at establishing a focal point in a semantic task (e.g. ‘Tell me any boy''s name’) that requires coordination relative to a similar, control semantic task that does not. Additionally, coordination limitations in bvFTD are related to cortical thinning in prefrontal cortex. These findings are consistent with behavioral economic models proposing that, beyond a ‘gut feeling’, strategic decision-making contributes to the coordination process, including a probabilistic mechanism that evaluates the salience of a response (e.g. is ‘John’ a frequent boy''s name), a hierarchical mechanism that iteratively models an opponent''s likely response and a mechanism involved in social perspective taking.  相似文献   
5.
ABSTRACT: Mortality is the most widely measured outcome parameter. Improvement of this outcome parameter in critical care is nowadays expected not to come from new technologies or treatment, but from delivering the right care at the right moment in a safe way. The measurement of mortality as an outcome parameter confronts us with a problem in providing follow-up to the results. Especially when proven structure and process interventions are applied already, the cause of a suboptimal performance cannot be deduced easily. One possibility is to evaluate the causes of death and to judge preventability. In this article we explore the opportunities and difficulties of a tool to evaluate preventable mortality in the ICU.  相似文献   
6.
IntroductionDifferent studies have described psychiatric comorbidities in inflammatory bowel disease (IBD) patients, but most of them focus mainly on depression and anxiety. Even though major mental disorders are considered one of the main factors that decrease quality of life (QoL), its role in IBD patients remains unclear. We sought to identify the prevalence of different mental disorders as well as its relationship with QoL.Patients and methodsSubjects were recruited from the IBD Clinic. IBD Questionnaire 32 and structured clinical interview (SCID) for DMS-IV Text Revision were applied. Demographic and clinical data were collected via self-report questionnaires and medical records. The correlation between mental disorders and QoL (IBDQ-32 score) was evaluated using the Spearman correlation test.ResultsIn all, 104 patients were recruited, 12 with Crohn's disease, and 92 with ulcerative colitis. The prevalence of any major mental disorder was 56.7%: anxiety (44.2%), mood (27.9%), substance use (12.2%), and other psychiatric diagnoses (17.3%), and 29.8% of the patients presented three or more comorbid diagnoses. Mental Disorder (p = 0.005), mood disorder (p = 0.004), anxiety disorder (p = 0.009), were found to be significantly associated with lower QoL. Substance use disorder was associated with lower Digestive QoL (p = 0.01). Major depressive disorder (p = 0.004), social phobia (p = 0.03), PTSD (p = 0.02), and Generalized Anxiety Disorder (p < 0.001), were found to be significantly associated with lower QoL.ConclusionsIBD patients had important psychiatric comorbidity that significantly affects their QoL. These results warrant a systematic evaluation of psychiatric conditions in IBD patients.  相似文献   
7.
To explore the role of oxytocin in the regulation of salt appetite and blood pressure, we conducted studies in oxytocin gene-knockout mice and determined (1) blood pressure and heart rate during day and night periods, (2) salt appetite after iso-osmotic volume depletion, and (3) salt appetite and blood pressure after central injection of angiotensin II. Long-term arterial catheters were inserted, and blood pressure and heart rate were recorded for 24 hours. There was a modest decrease in blood pressure and heart rate in knockout mice. Salt appetite was measured with a 2- bottle choice (water and 2% NaCl), with measurement of licking activity. Mice were injected subcutaneously with 30% polyethylene glycol (0.5 mL), and voluntary intakes were measured for 24 hours. Knockout mice consumed 3 times the amount of NaCl than did controls, 276+/-77 vs 90+/-38 licks/24 h (P<0.05). Water consumption was similar between groups. Angiotensin II (5, 50, and 200 ng/3 microL) injected intracerebroventricularly produced dose-related increases in intake, with no differences between the groups. The 50-ng dose of angiotensin II elicited salt and water intakes of 151+/-43 vs 160+/-33 licks and 250+/-53 vs and 200+/-51 licks, respectively (control vs knockout). The pressor response to angiotensin II was not different between the groups. Results suggest that oxytocin plays a role in the regulation of blood pressure and salt appetite, specifically as mediated by volume receptors, and that the renin-angiotensin system is not involved in these changes.  相似文献   
8.
Since the prevention of early chronic pancreatitis (ECP) into chronic pancreatitis might be critical for the reduction of pancreatic cancer, we tried to clarify the pathophysiology of ECP patients, focusing on ECP patients without alcoholic chronic pancreatitis. 27 ECP patients without alcoholic chronic pancreatitis and 33 patients with functional dyspepsia with pancreatic enzyme abnormalities (FD-P) were enrolled in this study. Diagnosis of ECP was made when imaging findings showed the presence of more than 2 out of 7 endoscopic ultrasound features. Duodenal degranulated eosinophils and glucagon-like peptide 1 producing cells were estimated by immunostaining. There were no significant differences in characteristics and psychogenic factors between ECP and FD-P patients. Interestingly, endoscopic ultrasound score in ECP patients significantly improved, albeit clinical symptoms in ECP patients showed no improvement at one year follow up. The extent of migration of duodenal degranulated eosinophils in FD-P patients was significantly higher compared to that in ECP patients. The levels of elastase-1 and trypsin in ECP patients with improved endoscopic ultrasound features were significantly reduced by the treatment. Further studies will be needed to clarify whether clinical symptoms and endoscopic ultrasound features in ECP patients without alcoholic chronic pancreatitis were improved in longer follow up study.  相似文献   
9.
10.
Colorectal cancer (CRC) can be divided into non-mucinous and mucinous subtypes, of which the latter portends to have a worse clinical prognosis. A previous study suggested a putative link between SOX2 expression observed selectively in mucinous CRC and the induction of the gastric mucin MUC5AC. In this study, we re-evaluated the expression behavior of SOX2, MUC5AC, and CDX2 in both types of CRC. We performed immunohistochemical analysis on 90 cases of non-mucinous CRCs, 57 cases of mucinous CRCs, and 15 case-matched normal intestinal mucosa. In contrast to the previously suggested link between SOX2 and mucinous CRC, we observe aberrant expression of SOX2 at equal levels in both subtypes. Fluorescence in situ hybridization (FISH) analysis shows that expression is not attributed to genomic amplification. While SOX2 and CDX2 are normally expressed in a reciprocal manner, SOX2-positive tumor cells co-express CDX2. Furthermore, we show that MUC5AC is expressed independently of SOX2. In conclusion, we show that aberrant SOX2 expression is specifically linked neither to mucinous CRCs nor to the induction of MUC5AC, in contrast to previous suggestions.  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