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   1440篇
  免费   103篇
  国内免费   4篇
耳鼻咽喉   7篇
儿科学   59篇
妇产科学   54篇
基础医学   226篇
口腔科学   9篇
临床医学   117篇
内科学   314篇
皮肤病学   46篇
神经病学   107篇
特种医学   24篇
外科学   197篇
综合类   7篇
一般理论   1篇
预防医学   101篇
眼科学   36篇
药学   98篇
中国医学   2篇
肿瘤学   142篇
  2024年   1篇
  2023年   17篇
  2022年   12篇
  2021年   69篇
  2020年   38篇
  2019年   44篇
  2018年   79篇
  2017年   56篇
  2016年   65篇
  2015年   56篇
  2014年   90篇
  2013年   94篇
  2012年   123篇
  2011年   127篇
  2010年   79篇
  2009年   61篇
  2008年   77篇
  2007年   94篇
  2006年   78篇
  2005年   69篇
  2004年   55篇
  2003年   57篇
  2002年   37篇
  2001年   14篇
  2000年   7篇
  1999年   5篇
  1998年   5篇
  1997年   7篇
  1996年   4篇
  1995年   4篇
  1994年   1篇
  1993年   2篇
  1992年   2篇
  1991年   3篇
  1990年   2篇
  1987年   2篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1979年   1篇
  1978年   1篇
  1975年   1篇
  1928年   1篇
排序方式: 共有1547条查询结果,搜索用时 44 毫秒
31.
32.
This study explores food preparation behaviors, including types of food prepared, methods of preparation, and frequency of preparation of low-income urban African American youth ages 9–15 in Baltimore City (n = 289) and analyzes a potential association to diet quality as measured through Healthy Eating Index 2010 (HEI) scores. Overall, the youth prepared their own food 6.7 ± 0.33 times per week without significant differences between age groups or genders as measured through pairwise comparison of means. Cereal, noodles, and sandwiches were amongst the foods prepared most frequently. Linear regression analysis found youth food preparation frequency was not significantly associated with total HEI (p = 0.59), sodium (p = 0.58), empty calories (p = 0.96), or dairy scores (p = 0.12). Younger age was associated with higher total HEI scores (p = 0.012) and higher dairy scores (p = 0.01) and female gender was associated with higher total HEI scores (p = 0.03), higher sodium scores (p = 0.03), and lower dairy scores (p = 0.008).  相似文献   
33.

Purpose

The purpose of the study was to summarize the experiences of African psychiatric nurses in their workplace by examining the findings of existing qualitative studies.

Methods

Eleven studies published in English, Portuguese, and Spanish, between 1998 and 2016, which explored psychiatric nurses' experiences in Africa, were included.

Findings

After meta-aggregation, five key findings were identified: 1) organization and management, 2) perceptions of professional safety and insecurity, 3) relationship with the patient, 4) emotional experiences and 5) recommendations for improvement.

Discussion

The findings in this study highlight the stressful nature of the work climate of the psychiatric nurse in South Africa. More focus on improving working conditions and providing support is necessary to increase the quality of care for psychiatric mental health patients and their nurse providers.  相似文献   
34.
Purpose: Transient ischemic attack (TIA) and mild stroke represent a large proportion of cerebrovascular events, at high risk of being followed by recurrent, serious events. The importance of early education addressing risk management, secondary prevention and lifestyle modifications is the centerpiece of further stroke prevention. However, delivering education and rehabilitation to this population can be complex and challenging.

Methods: Via synthesis of a narrative review and clinical experience, we explore the unique and inherent complexities of rehabilitation management and education provision for patients following mild stroke and TIA.

Results: A considerable proportion of TIA/mild stroke survivors have ongoing rehabilitation needs that are poorly addressed. The need for rehabilitation in these patients is often overlooked, and available assessment tools lack the sensitivity to identify common subtle impairments in cognition, mood, language and fatigue. Active and accessible education interventions need to be initiated early after the event, and integrated with ongoing rehabilitation management. Priority areas in need of future development in this field are highlighted and discussed.

  • Implications for rehabilitation
  • Survivors of mild stroke and TIA have ongoing unmet rehabilitation needs and require a unique approach to rehabilitation and education.

  • Rehabilitation needs are difficult to assess and poorly addressed in this cohort, where available assessment tools lack the sensitivity required to identify subtle impairments.

  • Education needs to be initiated early after the event and involve active engagement of the patient in order to improve stroke knowledge, mood and motivate adherence to lifestyle modifications and secondary prevention.

  • Rehabilitation physicians are currently an underutilized resource, who should be more involved in the management of all patients following TIA or mild stroke.

  相似文献   
35.
OBJECTIVE: Chromogranin A (CgA) is an acidic glycoprotein co-stored in vesicles and co-released with catecholamines. Although currently used as a humoral marker of endocrine tumours, several aspects of CgA secretion still need to be clarified in humans. PATIENTS: Fifty-four controls, 83 essential hypertensive and six adrenalectomized patients were studied. DESIGN: In the controls and hypertensive patients, CgA and catecholamines were measured before (supine position) and after changes in posture (2' upright position), insulin-induced hypoglycaemia (0.15 IU/kg i.v.) and glucagon injection (1 mg i.v.). In addition, blood samples were taken in the morning (0800 h) and in the afternoon (1800 h), and every 5 h for 24 h. In the adrenalectomized patients, blood samples were obtained in the morning and in the afternoon. MEASUREMENTS: CgA was measured by an immunoradiometric assay, and noradrenaline and adrenaline by high-performance liquid chromatography. RESULTS: In controls, posture slightly increased plasma catecholamines without affecting CgA levels. Hypoglycaemia evoked a rise in noradrenaline (P < 0.04), adrenaline (P < 0.01) and CgA (79.6 +/- 11.8 vs. 46.1 +/- 10.1 microg/l, P < 0.03). Glucagon injection increased plasma adrenaline (P < 0.01) but not noradrenaline or CgA levels. At variance with blood pressure and catecholamines, CgA increased significantly in the afternoon (51.1 +/- 4.0 vs. 45.0 +/- 3.9 microg/l, P < 0.05); it also had a circadian rhythm, with peak values during the night (at 2300 h, 65.4 +/- 9.0 microg/l) and a nadir in the morning (at 0800 h, 43.1 +/- 6.6 microg/l). In hypertensives, basal and stimulated CgA levels as well as diurnal/circadian variations of this peptide were similar to those in normal subjects. In adrenalectomized patients plasma CgA in the morning (34.3 +/- 6.5 microg/l) was lower (P < 0.03) than in all controls and hypertensives studied, but also showed an afternoon increment (46.4 +/- 6.6 microg/l, P < 0.003). No correlation was found between CgA and catecholamines or blood pressure in all subjects or in the subgroups. CONCLUSIONS: In normal humans, chromogranin A and catecholamines are not always co-secreted, and co-secretion occurs only for marked exocytotic adrenergic stimuli, such as hypoglycaemic stress. In addition, chromogranin A has a circadian rhythm unrelated to plasma catecholamines. Basal plasma concentrations and the secretory pattern of chromogranin A in hypertensives do not differ from the findings in controls. Finally, the adrenal glands contribute partially to circulating chromogranin A and are not involved in the circadian rhythm of this peptide in humans.  相似文献   
36.
Intercellular biomolecule transfer (ICBT) between malignant and benign cells is a major driver of tumor growth, resistance to anticancer therapies, and therapy-triggered metastatic disease. Here we characterized cholesterol 25-hydroxylase (CH25H) as a key genetic suppressor of ICBT between malignant and endothelial cells (ECs) and of ICBT-driven angiopoietin-2–dependent activation of ECs, stimulation of intratumoral angiogenesis, and tumor growth. Human CH25H was downregulated in the ECs from patients with colorectal cancer and the low levels of stromal CH25H were associated with a poor disease outcome. Knockout of endothelial CH25H stimulated angiogenesis and tumor growth in mice. Pharmacologic inhibition of ICBT by reserpine compensated for CH25H loss, elicited angiostatic effects (alone or combined with sunitinib), augmented the therapeutic effect of radio-/chemotherapy, and prevented metastatic disease induced by these regimens. We propose inhibiting ICBT to improve the overall efficacy of anticancer therapies and limit their prometastatic side effects.  相似文献   
37.
Autologous haematopoietic stem cell transplantation (HSCT) for relapsing–remitting multiple sclerosis is a potentially curative treatment, which can give rise to long‐term disease remission. However, the mode of action is not yet fully understood. The aim of the study was to evaluate similarities and differences of the CD4+ T‐cell populations between HSCT‐treated patients (n = 12) and healthy controls (n = 9). Phenotyping of memory T cells, regulatory T (Treg) cells and T helper type 1 (Th1) and type 17 (Th17) cells was performed. Further, T‐cell reactivity to a tentative antigen, myelin oligodendrocyte glycoprotein, was investigated in these patient populations. Patients treated with natalizumab (n = 15) were included as a comparative group. White blood cells were analysed with flow cytometry and T‐cell culture supernatants were analysed with magnetic bead panel immunoassays. HSCT‐treated patients had similar levels of Treg cells and of Th1 and Th17 cells as healthy subjects, whereas natalizumab‐treated patients had lower frequencies of Treg cells, and higher frequencies of Th1 and Th17 cells. Cells from HSCT‐treated patients cultured with overlapping peptides from myelin oligodendrocyte glycoprotein produced more transforming growth factor‐β1 than natalizumab‐treated patients, which suggests a suppressive response. Conversely, T cells from natalizumab‐treated patients cultured with those peptides produced more interleukin‐17 (IL‐17), IL‐1 and IL‐10, indicating a Th17 response. In conclusion, we demonstrate circumstantial evidence for the removal of autoreactive T‐cell clones as well as development of tolerance after HSCT. These results parallel the long‐term disease remission seen after HSCT.  相似文献   
38.
39.
40.
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