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   356篇
  免费   7篇
  国内免费   4篇
耳鼻咽喉   1篇
儿科学   43篇
妇产科学   7篇
基础医学   47篇
口腔科学   7篇
临床医学   30篇
内科学   58篇
皮肤病学   2篇
神经病学   37篇
特种医学   31篇
外科学   41篇
综合类   1篇
预防医学   11篇
眼科学   14篇
药学   23篇
中国医学   1篇
肿瘤学   13篇
  2024年   2篇
  2023年   1篇
  2022年   2篇
  2021年   14篇
  2020年   3篇
  2019年   16篇
  2018年   8篇
  2017年   8篇
  2016年   10篇
  2015年   7篇
  2014年   19篇
  2013年   23篇
  2012年   33篇
  2011年   39篇
  2010年   10篇
  2009年   22篇
  2008年   19篇
  2007年   19篇
  2006年   29篇
  2005年   16篇
  2004年   11篇
  2003年   12篇
  2002年   6篇
  2001年   3篇
  2000年   2篇
  1999年   5篇
  1998年   1篇
  1997年   2篇
  1994年   1篇
  1992年   3篇
  1991年   2篇
  1989年   1篇
  1988年   3篇
  1987年   1篇
  1986年   1篇
  1983年   1篇
  1982年   1篇
  1979年   3篇
  1978年   2篇
  1973年   3篇
  1972年   1篇
  1967年   1篇
  1966年   1篇
排序方式: 共有367条查询结果,搜索用时 15 毫秒
11.
Although numerous studies have documented outbreaks of carbapenem-resistant Klebsiella pneumoniae (CRKP) possessing various carbapenemases, reports on outbreaks due to CRKP possessing extended-spectrum β-lactamases (ESBLs) and/or AmpCs with porin lesions have been limited. Here, we describe an outbreak caused by an ertapenem-resistant, CTX-M-15-producing clonal K. pneumoniae strain expressing an OmpK36 porin variant. From May 2012 to November 2012, 37 ertapenem-resistant K. pneumoniae isolates phenotypically negative for carbapenemase production were recovered from 19 patients hospitalized in the intensive care unit of a Greek hospital. The isolates were either susceptible or intermediate to other carbapenems and resistant to all remaining β-lactams but cefotetan. Phenotypic and molecular analysis revealed the presence in all isolates of the blaCTX-M-15 gene on a conjugative 100-kb plasmid, disruption in the expression of the ompK35 gene, and the production of an Ompk36 porin variant. The index case was a patient admitted from another hospital. Active surveillance upon admission and on a weekly basis was immediately initiated; environmental samples were also periodically tested. Molecular typing showed that all clinical isolates as well as two ertapenem-resistant environmental K. pneumoniae isolates belonged to the same clonal type and were assigned to multilocus sequence typing (MLST) sequence type 101 (ST101). As all colonized/infected patients were hospitalized during overlapping periods, cross-infection was considered the main route for the dissemination of the outbreak strain. Despite reinforcement of infection control measures and active surveillance, the outbreak lasted approximately 7 months. Identification of hidden carriers upon admission and by screening on a weekly basis was found valuable for early recognition and subsequent successful management of the outbreak.  相似文献   
12.
The effect of dimethyl sulfoxide (DMSO) on cholesterol-induced atherosclerosis in the rabbit was investigated. Two groups of rabbits were studied: a Control group which received regular chow and an Experimental group which received an atherogenic diet containing 1% cholesterol. DMSO was either omitted or added to the drinking water of both groups in amounts of 2, 4, 5 and 6%. After 3 months all animals were autopsied; the thoracic aorta was examined for atheromatous lesions and the abdominal aorta assayed for total cholesterol content. As expected the thoracic aortas of all rabbits in the Control group were free of atheromatous lesions. With the exception of one rabbit in the Experimental group, all rabbits on the atherogenic diet which did not receive DMSO had extensive aortic lesions covering 82 +/- 5% of the surface area of the thoracic aorta. Aortic lesions were inhibited by about 50% in rabbits on 2% (dose, 1.5 g/kg) DMSO and virtually absent in the majority of rabbits on 4 (dose, 3.5 g/kg), 5 (dose, 5.5 g/kg) and 6% (dose, 9.1 g/kg) DMSO. The food intake of rabbits on the atherogenic diet was not suppressed by DMSO. Changes in the cholesterol content of the abdominal aortas paralleled the presence or absence of lesions in the thoracic aorta. Blood cholesterol levels were greatly elevated in all rabbits on the atherogenic diet and not lowered by DMSO. In conclusion, cholesterol induced atherosclerosis in the rabbit was inhibited by DMSO. This action of DMSO was independent of the hypercholesterolemia and not due to a suppression of food intake. DMSO may provide a useful probe for investigating the underlying mechanism(s) in the development of cholesterol induced atherosclerosis.  相似文献   
13.
Background: Whether psychological resilience correlates with neurocognitive performance is largely unknown. Therefore, we assessed association between neurocognitive performance and resilience in individuals with a history of childhood abuse or trauma exposure. Methods: In this cross‐sectional study of 226 highly traumatized civilians, we assessed neurocognitive performance, history of childhood abuse and other trauma exposure, and current depressive and PTSD symptoms. Resilience was defined as having ≥1 trauma and no current depressive or PTSD symptoms; non‐resilience as having ≥1 trauma and current moderate/severe depressive or PTSD symptoms. Results: The non‐resilient group had a higher percentage of unemployment (P=.006) and previous suicide attempts (P<.0001) than the resilient group. Both groups had comparable education and performance on verbal reasoning, nonverbal reasoning, and verbal memory. However, the resilient group performed better on nonverbal memory (P=.016) with an effect size of .35. Additionally, more severe childhood abuse or other trauma exposure was significantly associated with non‐resilience. Better nonverbal memory was significantly associated with resilience even after adjusting for severity of childhood abuse, other trauma exposure, sex, and race using multiple logistic regression (adjusted OR=1.2; P=.017). Conclusions: We examined resilience as absence of psychopathology despite trauma exposure in a highly traumatized, low socioeconomic, urban population. Resilience was significantly associated with better nonverbal memory, a measure of ability to code, store, and visually recognize concrete and abstract pictorial stimuli. Nonverbal memory may be a proxy for emotional learning, which is often dysregulated in stress‐related psychopathology, and may contribute to our understanding of resilience. Depression and Anxiety, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   
14.
AIM: To investigate whether smoking is associated with human papilloma virus (HPV) infection. METHODS: HPV infection is considered to be a necessary condition for cervical cancer development. The study population included 1291 women, aged 25-55 years, attending cervical cancer screening. All women had a Papanicolaou (Pap) test, with liquid-based cytology (Thinprep®), an HPV-DNA test and an evaluation of smoking habits. The COBAS® 4800 system was used for HPV-DNA testing, enabling identification of the following high-risk HPV (hrHPV)-types: each of HPVs 16 and 18 separately, and HPVs 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68 as a cocktail. The evaluation of smoking habits was assessed using the smoking intensity index (SII), a variable formed as the product of cigarettes consumed per day by the days (years × 365) that a woman was a smoker, divided by 1000. RESULTS: There were 136 smokers among 238 women tested positive for hrHPV-types (HPVs 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and/or 68), and 463 smokers among 1053 hrHPV-negative women (OR = 1.7, P < 0.001). This association was attributed to the youngest age group of women, aged 25-34 years (OR = 2.3, P < 0.001), while there was no association in other age groups. The intensity of smoking (increasing SII) showed no statistically significant association with hrHPV infection. Cervical infection with HPV 16 and/or HPV 18 was also not associated with age or smoking habits. Finally, no association was found between Pap test status and smoking habits or smoking intensity. CONCLUSION: Smoking appears to be associated with hrHPV infection of the uterine cervix, particularly in younger women. Further studies should investigate whether this association is based on causality and evaluate the role of other possible co-factors.  相似文献   
15.
Many features of posttraumatic stress disorder (PTSD) can be linked to exaggerated and dysregulated emotional responses. Central to the neurocircuitry regulating emotion are functional interactions between the amygdala and the ventromedial prefrontal cortex (vmPFC). Findings from human and animal studies suggest that disruption of this circuit predicts individual differences in emotion regulation. However, only a few studies have examined amygdala-vmPFC connectivity in the context of emotional processing in PTSD. The aim of the present research was to investigate the hypothesis that PTSD is associated with disrupted functional connectivity of the amygdala and vmPFC in response to emotional stimuli, extending previous findings by demonstrating such links in an understudied, highly traumatized, civilian population. 40 African-American women with civilian trauma (20 with PTSD and 20 non-PTSD controls) were recruited from a large urban hospital. Participants viewed fearful and neutral face stimuli during functional magnetic resonance imaging (fMRI). Relative to controls, participants with PTSD showed an increased right amygdala response to fearful stimuli (pcorr < .05). Right amygdala activation correlated positively with the severity of hyperarousal symptoms in the PTSD group. Participants with PTSD showed decreased functional connectivity between the right amygdala and left vmPFC (pcorr < .05). The findings are consistent with previous findings showing PTSD is associated with an exaggerated response of amygdala-mediated emotional arousal systems. This is the first study to show that the amygdala response may be accompanied by disruption of an amygdala-vmPFC functional circuit that is hypothesized to be involved in prefrontal cortical regulation of amygdala responsivity.  相似文献   
16.
Whether the amygdala responds in a stimulus- or a task-specific way, and how it corresponds to such effects in sensory cortices is dubious. Eighteen volunteers participated in a functional magnetic resonance imaging study in which they were asked to identify either emotion or gender in visually presented scenes, faces, and sentences. Amygdala and the lateral occipital complex showed similar stimulus effect with greater activation to scenes than to faces and sentences, whereas the superior temporal complex responded preferentially to sentences. No task effect was observed in the amygdala, whereas lateral occipital complex and superior temporal complex showed left lateralized selectivity to the emotional task. These results suggest that the amygdala is more sensitive to stimulus than explicit task parameters when processing emotion.  相似文献   
17.
Cerebral infarction is a rare complication of Mycoplasma pneumoniae infection. In all cases previously reported in the literature, vascular occlusion occurred in the anterior brain circulation, either the internal carotid or the middle cerebral artery. We report a case of a child with posterior cerebral artery occlusion and resultant hemiparesis associated with M. pneumoniae infection.  相似文献   
18.
19.
GABAB receptors have been implicated in the plastic changes occurring in the spinal cord during the development of chronic inflammatory pain. In this study, we evaluated whether the expression of GABAB(1b) receptor mRNA is regulated supraspinally, namely in the thalamus, as part of the response to chronically enhanced noxious input arising from experimental monoarthritis (MA).In situ hybridization with [35S]-labelled oligonucleotide probes was performed in sections of control, 2, 4, 7 and 14 days MA rats’ brains (n = 6/group). The distribution of GABAB(1b) mRNA was determined bilaterally in the ventrobasal complex (VB), posterior (Po), centromedial/centrolateral (CM/CL) and reticular (Rt) thalamic nuclei. The amount of GABAB(1b) mRNA was expressed as times fold of background values.In normal animals, values of mRNA expression were very similar in VB, Po and CM/CL, ranging from 2.2 ± 0.2 to 2.7 ± 0.4 (mean ± S.E.M.) times higher than background levels. No expression of GABAB(1b) mRNA was found in the Rt of control or MA animals. A significant decrease of 26% at 4 days, and 37% at 7 days of MA, was observed in the VB contralateral to the affected joint. On the contrary, in the Po there was a significant bilateral increase at 2 days (38% contralaterally, 25% ipsilaterally), returning to basal levels at 4 days MA. No significant changes were observed in CM/CL.These results suggest that the expression of GABAB(1b) in the VB and Po is regulated by noxious input, and might contribute to the functional changes that occur in the thalamus during chronic inflammatory pain.  相似文献   
20.
The present study was planned to verify if an adherence-enhancement activity program would be able to increase the frequency of exercising among sedentary diabetic patients. Twelve type 2 diabetic patients, one type 1 and one with secondary diabetes were included in the current study. Forty classes were first commanded by a teacher and then by a student. Adherence to the program was reinforced through a rewarding schedule. Six family members were encouraged to support physical activity. At home, each student registered his/her physical activity daily. Fitness evaluation and glycosylated hemoglobin were carried out before the program, at the end of the third month and at the follow-up. Nine participants completed the program and increased their physical activity at home. At the end of the third month, mean glycosylated hemoglobin of the patients persisting at the program was significantly lower than basal values. Involving family members contributed to promote adherence.  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