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   172篇
  免费   27篇
  国内免费   2篇
儿科学   7篇
妇产科学   10篇
基础医学   46篇
临床医学   36篇
内科学   36篇
神经病学   22篇
特种医学   8篇
外科学   10篇
预防医学   16篇
眼科学   1篇
药学   4篇
中国医学   1篇
肿瘤学   4篇
  2024年   1篇
  2023年   2篇
  2022年   3篇
  2021年   1篇
  2020年   3篇
  2019年   1篇
  2018年   9篇
  2017年   2篇
  2016年   4篇
  2015年   5篇
  2014年   5篇
  2013年   11篇
  2012年   23篇
  2011年   18篇
  2010年   9篇
  2009年   7篇
  2008年   16篇
  2007年   11篇
  2006年   6篇
  2005年   9篇
  2004年   7篇
  2003年   6篇
  2002年   8篇
  2001年   10篇
  2000年   5篇
  1999年   9篇
  1998年   4篇
  1993年   1篇
  1992年   1篇
  1990年   1篇
  1986年   2篇
  1985年   1篇
排序方式: 共有201条查询结果,搜索用时 31 毫秒
1.
In Iceland, the crude prevalence for all types of primary dystonia was 37.1/10(5) (confidence interval, 30.4-44.9). Focal dystonia had the highest prevalence (31.2/10(5)), followed by segmental (3.1/10(5)), multifocal (2.4/10(5)) and generalized dystonia (0.3/10(5)). Cervical dystonia was the most common focal dystonia (11.5/10(5)), followed by limb dystonia (8.0/10(5)), laryngeal dystonia (5.9/10(5)), blepharospasm (3.1/10(5)), and oromandibular dystonia (2.8/10(5)). The male:female ratio for all patients was 1:1.9 (P=0.0007), and females outnumbered males in all subtypes except oromandibular dystonia. Mean age of onset for all patients was 42.7 years (range, 3-82 years). This prevalence of primary dystonia is higher than in most reported studies, possibly because of more complete ascertainment but the relative frequencies of dystonia subtypes is similar.  相似文献   
2.
Immunization with a pneumococcal conjugate vaccine (PNC) containing serotype 19F induces cross-reactive antibodies to 19A in mice and human infants. Active immunization with PNC and passive immunization with serum samples from infants vaccinated with PNC containing serotype 19F, but not serotype 19A, protected against lung infection caused by both serotypes in a murine model.  相似文献   
3.
The aim of vaccination is to rapidly elicit protective immunity and generate memory for sustained protection. We studied the induction and persistence of polysaccharide (PS)-specific memory in neonatal and infant mice primed with pneumococcal conjugate (Pnc1-TT) by assessing the response to native pneumococcal PS (PPS-1), the kinetics of the PPS-1-specific IgG response to a second Pnc1-TT dose and affinity maturation. A subcutaneous (s.c.) Pnc1-TT booster induced a rapid increase in PPS-1-specific IgG, indicating efficient priming for memory by a single dose of Pnc1-TT already at 1 week of age. High levels were maintained for >12 weeks. However, a PPS-1 booster induced no response in neonatal or infant mice. The adjuvant LT-K63 significantly enhanced the IgG response and affinity to Pnc1-TT by both the s.c. and the intranasal (i.n.) route in all age groups. In neonatal and infant mice, PPS-1 and LT-K63 induced a booster response only when given i.n. following either s.c. or i.n. priming with Pnc1-TT and LT-K63. In contrast, PPS-1 with or without LT-K63 administered s.c. compromised the ongoing PPS-1-specific response elicited in neonatal mice by either s.c. or i.n. priming with Pnc1-TT and LT-K63. These results demonstrate the advantage of the mucosal route for elicitation of PS-specific memory responses in early life.  相似文献   
4.
Pneumococcal conjugate vaccines will eventually be licensed after favorable results from phase III efficacy trials. After licensure of a conjugate vaccine for invasive pneumococcal disease in infants, new conjugate vaccines will likely be licensed primarily on the basis of immunogenicity data rather than clinical efficacy. Analytical methods must therefore be developed, evaluated, and validated to compare immunogenicity results accurately within and between laboratories for different vaccines. At present no analytical technique is uniformly accepted and used in vaccine evaluation studies to determine the acceptable level of agreement between a laboratory result and the assigned value for a given serum sample. This multicenter study describes the magnitude of agreement among 12 laboratories quantifying an identical series of 48 pneumococcal serum specimens from 24 individuals (quality-control sera) by a consensus immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) developed for this study. After provisional or trial antibody concentrations were assigned to the quality-control serum samples for this study, four methods for comparison of a series of laboratory-determined values with the assigned concentrations were evaluated. The percent error between assigned values and laboratory-determined concentrations proved to be the most informative of the four methods. We present guidelines that a laboratory may follow to analyze a series of quality-control sera to determine if it can reproduce the assigned antibody concentrations within an acceptable level of tolerance. While this study focused on a pneumococcal IgG ELISA, the methods that we describe are easily generalizable to other immunological assays.  相似文献   
5.
Previous work has shown that voluntary running increases cell proliferation and neurogenesis in the dentate gyrus of the adult hippocampus. Here we report that long-term running for 24 days results in a down-regulation of hippocampal progenitor proliferation to one-half the level of nonrunning controls compared with a fivefold increase in progenitor proliferation seen after 9 days of voluntary running (short-term running). The negative effects seen on proliferation after 24 days of running were prevented by restricting daily running distances (by 30-50%) during 24 days. Long-term running for 24 days increases the response of the hypothalamic-pituitary-adrenal axis, with an increase in adrenal gland weight and increased plasma corticosterone levels, as well as decreased thymus weight, indicating a stress response as a possible mediator of decreased progenitor proliferation. Furthermore, the negative effects seen on the observed stress response after 24 days of running were prevented by restricting daily running distance. Short-term running did not alter these stress parameters compared with nonrunning controls. However, it increased phosphorylated cyclic AMP response element binding protein (pCREB) in the dentate gyrus, an increase that was not seen in nonrunning controls or after 24 days of running. Taken together, these data suggest that voluntary running does not always enhance proliferation and that the decrease in progenitor proliferation seen in long-term running is possibly mediated by mechanisms involving a stress response in the animal. However, a moderate level of long-term running was able to prevent the negative stress-related changes seen in unrestricted long-term running.  相似文献   
6.
The effects of somatic nerve stimulation on cholera toxin induced secretion was investigated in vivo in anaesthetised rats. Small intestinal secretion was induced with cholera toxin and measured by a gravimetric technique. Afferent stimulation (pulse frequency within train; 100 Hz; train duration: 50 ms; train frequency: 3 Hz) of the sciatic nerve over 30 min significantly reduced the net fluid secretion both during (P < 0.05) and after cessation of the stimulation (P < 0.01). The greatest effect was obtained immediately after the termination of the nerve stimulation when the secretion was reversed to net fluid absorption. The opioid receptor antagonist naloxone (10 mg kg(-1) i.v.) administrated during the stimulation, significantly inhibited the antisecretory effect seen after the stimulation, thus no significant difference was seen between the control period and the periods after cessation of the stimulation. The opioid receptor antagonist naloxone methiodide (10 mg kg(-1) i.v.), which does not cross the blood-brain barrier, partly inhibited the antisecretory effects but not with the same magnitude as naloxone, thus the net fluid secretion was still significantly inhibited after the stimulation (P < 0.05). We conclude that afferent stimulation of the sciatic nerve strongly inhibits the cholera toxin induced secretion in the small intestine. This inhibition involves primarily a central opioid mechanism and to a lesser extent peripheral opioid mechanism.  相似文献   
7.
8.
A mutation in the human cystatin C gene leads to familial cerebral amyloid angiopathy. This disease is known as “hereditary cerebral hemorrhage with amyloidosis-Icelandic type” or “hereditary cystatin C amyloid angiopathy.” The mutant cystatin C protein forms aggregates and amyloid, within the central nervous system almost exclusively in connection with the vascular system. It was not known whether immune cells could remove mutant cystatin C protein aggregates. Ex vivo mutant cystatin C protein aggregates, both in solution and dried onto a glass surface, induced adhesion to the substrate, differentiated the THP-1 monocyte cell line and led to a proinflammatory response. Aggregates were also taken up by both THP-1 cells and THP-1 derived macrophages. These are the same responses induced by other amyloidogenic protein species, such as amyloid β protein and amylin, supporting the model of all amyloidogenic proteins being toxic due to common structural motifs. Proinflammatory response induced by the ex vivo mutant cystatin C protein aggregates suggests that vascular inflammation plays an important role in hereditary cerebral hemorrhage with amyloidosis-Icelandic type. Ex vivo protein aggregates of cystatin C might better model cellular behavior than in vitro-generated aggregates or supplement in vitro material.  相似文献   
9.

Objective

To examine how cardiorespiratory fitness and self-perceived stress are associated with burnout and depression. To determine if any relationship between stress and burnout/depression is mitigated among participants with high fitness levels.

Methods

197 participants (51% men, mean age = 39.2 years) took part in the study. The Åstrand bicycle test was used to assess cardorespiratory fitness. Burnout was measured with the Shirom–Melamed Burnout Questionnaire (SMBQ), depressive symptoms with the Hospital Anxiety and Depression Scale (HAD-D). A gender-matched stratified sample was used to ensure that participants with varying stress levels were equally represented.

Results

Participants with moderate and high fitness reported fewer symptoms of burnout and depression than participants with low fitness. Individuals with high stress who also had moderate or high fitness levels reported lower scores on the SMBQ Tension subscale and the HAD-D than individuals with high stress, but low fitness levels.

Conclusion

Better cardiovascular fitness seems to be associated with decreased symptoms of burnout and a better capacity to cope with stress.

Practical implications

Promoting and measuring cardiorespiratory fitness can motivate employees to adopt a more physically active lifestyle and thus strengthen their ability to cope with stress exposure and stress-related disorders.  相似文献   
10.
AIM: To study if and how physicians use the irritable bowel syndrome (IBS) diagnostic criteria and to assess treatment strategies in IBS patients. METHODS: A questionnaire was sent to 191 physicians regarding IBS criteria, diagnostic methods and treatment. Furthermore, 94 patients who were diagnosed with IBS underwent telephone interview. RESULTS: A total of 80/191 (41.9%) physicians responded to the survey. Overall, 13 patients were diag-nosed monthly with IBS by specialists in gastroenterology (SGs) and 2.5 patients by general practitioners (GPs). All the SGs knew of the criteria to diagnose IBS, as did 46/70 (65.7%) GPs. Seventy-nine percent used the patient’s history, 38% used a physical examination, and 38% exclusion of other diseases to diagnose IBS. Only 18/80 (22.5%) physicians used specific IBS criteria. Of the patients interviewed, 59/94 (62.8%) knew they had experienced IBS. Two out of five patients knew IBS and had seen a physician because of IBS symptoms. Half of those received a diagnosis of IBS. A total of 13% were satisfied with treatment. IBS affected daily activities in 43% of cases. CONCLUSION: Half of the patients with IBS who consulted a physician received a diagnosis. Awareness and knowledge of diagnostic criteria for IBS differ between SGs and GPs.  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