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   650篇
  免费   26篇
  国内免费   21篇
耳鼻咽喉   1篇
儿科学   26篇
妇产科学   6篇
基础医学   60篇
口腔科学   38篇
临床医学   48篇
内科学   190篇
皮肤病学   13篇
神经病学   19篇
特种医学   96篇
外科学   57篇
综合类   51篇
预防医学   27篇
眼科学   6篇
药学   41篇
肿瘤学   18篇
  2022年   5篇
  2021年   4篇
  2020年   3篇
  2019年   4篇
  2018年   12篇
  2017年   5篇
  2016年   4篇
  2015年   10篇
  2014年   9篇
  2013年   23篇
  2012年   8篇
  2011年   14篇
  2010年   27篇
  2009年   25篇
  2008年   11篇
  2007年   36篇
  2006年   37篇
  2005年   12篇
  2004年   31篇
  2003年   17篇
  2002年   18篇
  2001年   14篇
  2000年   11篇
  1999年   11篇
  1998年   33篇
  1997年   34篇
  1996年   40篇
  1995年   22篇
  1994年   15篇
  1993年   22篇
  1992年   10篇
  1991年   7篇
  1990年   7篇
  1989年   28篇
  1988年   16篇
  1987年   19篇
  1986年   11篇
  1985年   11篇
  1984年   11篇
  1983年   5篇
  1982年   6篇
  1981年   7篇
  1980年   10篇
  1979年   3篇
  1978年   3篇
  1977年   5篇
  1976年   5篇
  1975年   5篇
  1938年   1篇
  1935年   1篇
排序方式: 共有697条查询结果,搜索用时 281 毫秒
41.
Objectives: Although research shows that nursing home staff experience significant levels of stress and burnout, studies analyzing the relationship of psychosocial variables on their feelings of anxiety are scarce. This study aims to analyze the relationship between psychosocial variables and levels of anxiety among staff.

Method: Participants were 101 nursing home professionals. In addition to anxiety, socio-demographic variables, depersonalization, burden, relationship with families of the residents, and guilt about the care offered to the residents were assessed. A hierarchical regression analysis was carried out to analyze the contribution of the assessed variables to staff anxiety levels.

Results: The obtained model explained 57% of the variance in anxious symptomatology. Guilt about the care offered and poor quality of the relationship with residents’ family were associated with anxiety. Further, working at nursing homes where the staff report higher levels of anxiety symptoms, the presence of depersonalization and burden were also associated with anxiety.

Conclusion: The findings suggest that in addition to work-related variables (burden and burnout), problems with family members and guilt about the care offered are relevant variables for understanding staff’s anxious symptomatology.

Clinical Implications: Interventions that address issues of guilt about the quality of care, and problematic relationships with family members of residents, may have potential to reduce staff anxiety and promote their well-being.  相似文献   

42.
43.
The purpose of this study was to analyze the expression of B cell growth factor (BCGF) receptors and to elucidate the biologic effects of biochemically purified natural BCGF at the B cell precursor stage of human B lineage lymphoid differentiation. The specific binding of radioiodinated high-mol-wt BCGF (125I-HMW-BCGF) and low-molecular-wt BCGF (125I-LMW-BCGF) to fresh marrow blasts from B cell precursor acute lymphoblastic leukemia (ALL) patients was initially investigated. The estimated number of radioiodinated BCGF molecules bound per blast ranged from undetectable to 24.3 X 10(3) for HMW-BCGF, and from 11.5 X 10(3) to 457.8 X 10(3) for LMW-BCGF. In 3H-TdR incorporation assays, 75% of cases showed a significant response to LMW-BCGF with a median stimulation index of 9.3. By comparison, only 33% of cases showed a significant response to HMW-BCGF with a median stimulation index of 2.4. Subsequently, B cell precursor colony assays were performed to assess and compare the biologic effects of BCGF on leukemic B lineage lymphoid progenitor cells. Among 28 cases studied, 57% responded to both HMW-BCGF and LMW-BCGF, 21% responded only to LMW-BCGF, and the remaining cases showed no proliferative response to either growth factor. The response patterns of virtually pure populations of FACS- sorted leukemic B cell precursors were essentially identical to the proliferative responses of unsorted leukemic B-cell precursors. Synergistic effects between HMW-BCGF and LMW-BCGF were observed in 80% of the cases that responded to both. The numbers of cell-bound radioiodinated BCGF molecules, the stimulation indices, as well as the number of B cell precursor colonies in BCGF-stimulated cultures showed a marked interpatient variation. Patients with structural chromosomal abnormalities (SCAs) involving 12p11-13 or patients with a Philadelphia chromosome showed a greater HMW-BCGF response at the level of leukemic progenitor cells than did other patients (P = .02). The LMW-BCGF response was significantly greater for patients with SCA than for patients without SCA (P = .04). The response of leukemic progenitor cells to HMW-BCGF or LMW-BCGF did not correlate with sex, age, disease status, FAB morphology, WBC at diagnosis, or immunophenotype. To our knowledge, this study represents the first detailed analyses of BCGF receptor expression and BCGF effects in B cell precursor ALL. The data presented provide direct evidence for the expression of functional receptors for both HMW-BCGF and LMW-BCGF in B cell precursor ALL.  相似文献   
44.
OBJECTIVE: To determine whether deficient activity of the hypothalamic corticotropin-releasing hormone (CRH) neuron, which stimulates the hypothalamic-pituitary-adrenal (HPA) axis and the central control nuclei of the sympathetic nervous system and inhibits ascending pain pathways, may be pathogenic in patients with fibromyalgia (FM). METHODS: We administered interleukin-6 (IL-6; 3 microg/kg of body weight subcutaneously), a cytokine capable of stimulating hypothalamic CRH release, and measured plasma levels of adrenocorticotropic hormone (ACTH), cortisol, and catecholamines and their metabolites and precursors. Thirteen female FM patients and 8 age- and body mass index-matched female controls were studied. The diagnosis of FM was made according to American College of Rheumatology criteria. Tender points were quantitated by pressure algometry. All subjects had HPA axis studies. Seven FM patients and 7 controls also had catecholamine measurements. RESULTS: After IL-6 injection, delayed ACTH release was evident in the FM patients, with peak levels at 96.9 +/- 6.0 minutes (mean +/- SEM; control peak 68.6 +/- 10.3 minutes; P = 0.02). Plasma cortisol responses to IL-6 did not differ significantly between patients and controls. Basal norepinephrine (NE) levels were higher in the FM patients than in the controls. While a small, although not significant, rise in NE levels occurred after IL-6 injection in the controls, NE levels dramatically increased over basal levels in the FM patients between 60 and 180 minutes after IL-6 injection. Both peak NE levels (mean +/- SEM 537.6 +/- 82.3 versus 254.3 +/- 41.6 pg/ml; P = 0.0001) and time-integrated NE responses (93.2 +/- 16.6 pg/ml x minutes(-3) versus 52.2 +/- 5.7 pg/ml x minutes(-3); P = 0.038) were greater in FM patients than in controls. Heart rate was increased by IL-6 injection in FM patients and controls, but rose to significantly higher levels in the FM patients from 30 minutes to 180 minutes after IL-6 injection (P < 0.03). CONCLUSION: Exaggerated NE responses and heart rate increases, as well as delayed ACTH release, were observed among female FM patients compared with age-matched female controls. Delayed ACTH release after IL-6 administration in FM is consistent with a defect in hypothalamic CRH neuronal function. Exaggerated NE release may reflect abnormal regulation of the sympathetic nervous system, perhaps secondary to chronically deficient hypothalamic CRH. The excessive heart rate response after IL-6 injection in FM patients may be unrelated to the increase in NE, or it may reflect an alteration in the sensitivity of cardiac beta-adrenoceptors to NE. These responses to a physiologic stressor support the notion that FM may represent a primary disorder of the stress system.  相似文献   
45.
Although renal abnormalities have been described in children with Alagille's syndrome, cystic kidney disease has not often been documented, and then usually only at necropsy. Three children with Alagille's syndrome are described, in two of whom a unilateral multicystic dysplastic kidney was detected by prenatal ultrasound; in the other, a solitary cortical cyst was found later in childhood. All have normal renal function, growth, and liver synthetic function but continue to have clinical and biochemical signs of cholestasis. These cases show that unilateral cystic kidney disease with or without renal dysplasia may be associated with Alagille's syndrome, that the clinical course is not necessarily unfavourable, and that Alagille's syndrome should be included in the differential diagnosis of cystic kidney disorders associated with cholestatic liver disease. Patients with Alagille's syndrome should be evaluated by renal ultrasound.  相似文献   
46.
47.
48.
49.
50.
OBJECTIVES: To examine the frequency of central nervous system (CNS) disease in primary Sjogrens syndrome (pSS) and indicate ways in which cerebral magnetic resonance imaging (MRI) may help determine the significance of CNS involvement. METHODS: The current review was based on a Medline (Pubmed) literature search through May 2003, focused on Sjogrens syndrome, other vasculitides, multiple sclerosis (MS), specific MRI techniques, and MRI findings with regard to the above-mentioned diseases. Additional literature was identified in the reference sections of articles listed in Medline. RESULTS: Severe CNS manifestations reminiscent of MS have been described in pSS patients. Moreover, the prevalence of nonfocal neuropsychological abnormalities has been found to be elevated in some pSS patient populations. MRI studies suggest discrete cerebral tissue damage even in neurologically asymptomatic patients. However, small white matter lesions are nonspecific and may be related to age or cerebrovascular risk factors such as hypertension. A large controlled study, complementing established T2-weighted MRI with fluid-attenuated inversion recovery (FLAIR) to achieve high sensitivity in lesion detection, could indicate the disease specificity of white matter lesions in pSS. Newer MR techniques, such as spectroscopy and magnetization transfer imaging, applied, for example, in MS and systemic lupus erythematosus (SLE) to evaluate CNS tissue injury, could help determine the extent and mechanisms of macroscopic and microscopic CNS lesions in pSS. CONCLUSIONS: Future controlled studies will be necessary to more precisely estimate the prevalence of CNS lesions in pSS, specifically of discrete white matter abnormalities. Newer MRI techniques have the potential to provide information on the severity and pathophysiological mechanisms of CNS tissue damage.  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