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   5076篇
  免费   429篇
  国内免费   21篇
耳鼻咽喉   21篇
儿科学   185篇
妇产科学   91篇
基础医学   762篇
口腔科学   52篇
临床医学   581篇
内科学   1154篇
皮肤病学   92篇
神经病学   523篇
特种医学   122篇
外科学   599篇
综合类   53篇
一般理论   1篇
预防医学   521篇
眼科学   78篇
药学   401篇
中国医学   15篇
肿瘤学   275篇
  2023年   76篇
  2022年   37篇
  2021年   203篇
  2020年   145篇
  2019年   203篇
  2018年   201篇
  2017年   148篇
  2016年   175篇
  2015年   189篇
  2014年   216篇
  2013年   282篇
  2012年   418篇
  2011年   447篇
  2010年   232篇
  2009年   193篇
  2008年   360篇
  2007年   316篇
  2006年   365篇
  2005年   321篇
  2004年   291篇
  2003年   265篇
  2002年   185篇
  2001年   25篇
  2000年   11篇
  1999年   29篇
  1998年   28篇
  1997年   25篇
  1996年   14篇
  1995年   27篇
  1994年   15篇
  1993年   11篇
  1992年   10篇
  1991年   9篇
  1990年   7篇
  1989年   10篇
  1987年   2篇
  1986年   2篇
  1984年   4篇
  1983年   4篇
  1982年   6篇
  1977年   1篇
  1976年   2篇
  1971年   1篇
  1969年   1篇
  1967年   2篇
  1935年   1篇
  1934年   1篇
  1930年   1篇
  1924年   1篇
  1906年   1篇
排序方式: 共有5526条查询结果,搜索用时 46 毫秒
1.
Macrophages are a diverse myeloid cell population involved in innate and adaptive immune responses, embryonic development, wound repair, and regulation of tissue homeostasis. These cells link the innate and adaptive immunities and are crucial in the development and sustainment of various inflammatory diseases. Macrophages are tissue-resident cells in steady-state conditions; however, they are also recruited from blood monocytes after local pathogen invasion or tissue injury. Peritoneal macrophages vary based on their cell complexity, phenotype, and functional capabilities. These cells regulate inflammation and control bacterial infections in the ascites of decompensated cirrhotic patients. Our recent work reported several phenotypic and functional characteristics of these cells under both healthy and pathological conditions. A direct association between cell size, CD14/CD16 expression, intracellular level of GATA-6, and expression of CD206 and HLA-DR activation/maturation markers, indicate that the large peritoneal macrophage CD14highCD16high subset constitutes the mature phenotype of human resident peritoneal macrophages during homeostasis. Moreover, elevated expression of CD14/CD16 is related to the phagocytic capacity. The novel large CD14highCD16high peritoneal subpopulation is increased in the ascites of cirrhotic patients and is highly sensitive to lipopolysaccharide (LPS)-induced activation, thereby exhibiting features of inflammatory priming. Thus, phosphorylation of ERK1/2, PKB/Akt, and c-Jun is remarkably increased in response to LPS in vitro, whereas that of p38 MAPK is reduced compared with the monocyte-derived macrophages from the blood of healthy controls. Furthermore, in vitro activated monocyte-derived macrophages from ascites of cirrhotic patients secreted significantly higher levels of IL-6, IL-10, and TNF-α and lower amounts of IL-1β and IL-12 than the corresponding cells from healthy donor’s blood. Based on these results, other authors have recently reported that the surface expression level of CD206 can be used to identify mature, resident, inflammatory peritoneal macrophages in patients with cirrhosis. Soluble CD206 is released from activated large peritoneal macrophages, and increased concentrations in patients with cirrhosis and spontaneous bacterial peritonitis (SBP) indicate reduced odds of survival for 90 d. Hence, the level of soluble CD206 in ascites might be used to identify patients with SBP at risk of death. In conclusion, peritoneal macrophages present in ascites of cirrhotic patients display multiple phenotypic modifications characterized by reduced ratio of cells expressing several membrane markers, together with an increase in the ratios of complex and intermediate subpopulations and a decrease in the classic-like subset. These modifications may lead to the identification of novel pharmaceutical targets for prevention and treatment of hepatic damage.  相似文献   
2.
3.
Abstract

Objectives: To explore the acceptability of telepresence robots in dementia care from the perspectives of people with dementia, family carers, and health professionals/trainees, and investigate the utility of a social presence assessment tool, the Modified-Temple Presence Inventory (Modified-TPI), for people with dementia.

Method: A mixed-methods pilot study conducted in a social robotics laboratory. Three participant groups (n?=?22) – dyads of people with dementia and their carers (n?=?5 respectively), and health professionals/trainees (n?=?12) – participated in individual one-off intervention sessions with the telepresence robot, Giraff, with follow-up interviews. Sessions covered how to use Giraff, followed by interactive practice in making a video-call involving conversation and manoeuvring of Giraff. Participants with dementia experienced receiving a call made by their carer; healthcare professionals/trainees experienced making and receiving a call. Outcomes of interest were sense of presence [Modified-TPI], affective response (International Positive and Negative Affect Schedule [I-PANAS-S]; Observable Displays of Affect Scale [ODAS]), and attitudes and reactions to Giraff (semi-structured interviews).

Results: Participants reported a sense of authenticity and social connection through the experience. They indicated positive social presence through Giraff, and significantly higher positive (mean score 18.77; ±4.00) than negative affect (mean score 8.05; ±1.76) on the I-PANAS-SF, and on the facial display subscale of the ODAS (positive – mean score 15.50; ±3.51 versus negative – mean score 4.00; ±0.00).

Conclusion: Telepresence has potential use in situations where people with dementia require social connection. Studies with larger sample sizes, varied characteristics, and cost-effectiveness analysis are needed to inform the application of telepresence in healthcare practice.  相似文献   
4.
Objective: This cross-sectional study assessed the effect of food donations on total nutrient intake of clients of a food pantry in Central Texas.

Methods: Nutrient intakes of total, base and food donation diets were estimated for 112 food pantry recipients using specific questionnaires; and then compared to the dietary reference intakes (DRI) and 2015–2020?US Dietary Guidelines.

Results: Food donations accounted for more than half of the client’s daily intake of energy, carbohydrates, vitamin B6, phosphorus, copper and selenium. Yet, daily total intake remained less than their DRIs for carbohydrates, poly-unsaturated fats, dietary fiber, fat soluble vitamins and vitamin C, and was even lower for calcium, magnesium and potassium. Total food intake of clients almost met the US Dietary Guidelines for refined grains, fruits, vegetables, and meat; however, the amount of whole grains and dairy was inadequate.

Conclusions: Supplemental foods offered at food pantries are an important resource for improving nutrient intake of low-income populations.  相似文献   

5.
BackgroundAcute appendicitis (AA) is one of the most frequent surgical pathologies in pediatrics.ObjectivesTo investigate the utility of proadrenomedullin (pro-ADM) for the diagnosis of AA.MethodsProspective, analytical, observational, and multicenter study conducted in 6 pediatric emergency departments. Children up to 18 years of age with suspected AA were included. Clinical, epidemiological, and analytical data were collected.ResultsWe studied 285 children with an average age of 9.5 years (95% confidence interval [CI], 9.1–9.9). AA was diagnosed in 103 children (36.1%), with complications in 10 of them (9.7%). The mean concentration of pro-ADM (nmol/L) was higher in children with AA (0.51 nmol/L, SD 0.16) than in children with acute abdominal pain (AAP) of another etiology (0.44 nmol/L, SD 0.14; p < 0.001). This difference was greater in complicated cases compared with uncomplicated AA (0.64 nmol/L, SD 0.17 and 0.50 nmol/L, SD 0.15, respectively; p = 0.005). The areas under the receiver-operating characteristic curves were 0.66 (95% CI, 0.59–0.72) for pro-ADM, 0.70 (95% CI, 0.63–0.76) for C-reactive protein (CRP), 0.84 (95% CI, 0.79–0.89) for neutrophils, and 0.84 (95% CI, 0.79–0.89) for total leukocytes. The most reliable combination to rule out AA was CRP ≤1.25 mg/dL and pro-ADM ≤0.35 nmol/L with a sensitivity of 96% and a negative predictive value of 93%.ConclusionChildren with AA presented higher pro-ADM values than children with AAP of other etiologies, especially in cases of complicated AA. The combination of low values of pro-ADM and CRP can help to select children with low risk of AA.  相似文献   
6.
7.
Hepatocellular carcinoma(HCC) is the most common primary hepatic malignancy, which usually arises in cirrhotic liver. When the typical enhancement pattern, consisting of late arterial hyperenhancement followed by washout, is present in nodules larger than 1 cm, HCC can be confidently diagnosed without the need for tissue biopsy. Nevertheless, HCC can display an atypical enhancement pattern, either as iso or hypovascular lesion, or hypervascular lesion without washout. Not only the enhancement pattern of HCC could be atypical, but also a variety of histological types of HCC, such as steatotic, scirrhous, fibrolamellar, or combined hepatocellular-cholangiocellular carcinoma could raise diagnostic dilemmas. In addition, distinct morphological types of HCC or different growth pattern can occur. Awareness of these atypical and rare HCC presentations on magnetic resonance imaging is important for accurate differentiation from other focal liver lesions and timely diagnosis, which allows optimal treatment of patients.  相似文献   
8.
Rosacea and the cardiometabolic syndrome are both associated with chronic inflammation and a pro‐inflammatory phenotype. Emerging clinical evidence supports the relationship between rosacea and cardiometabolic syndrome hypertension and obesity. This article reviews our current findings and understanding in the skin and cardiovascular relationship in rosacea. Rosacea appears to be associated with hypertension, dyslipidemia, and obesity. The role of smoking in rosacea is currently less clear. It remains uncertain whether treatment of these risk factors will aid improvement of rosacea. Greater understanding of rosacea and its association with the cardiovascular system and underlying risk factors could allow for a greater understanding of the body's inflammatory response as well as the formulation of new guidelines for attending clinicians. Dermatologists treating rosacea patients might need to consider enquiring and evaluate their patients' underlying cardiovascular risk factors.  相似文献   
9.
ABSTRACT

Skilled professional artists are sometimes able to maintain their talents while other cognitive functions deteriorate due to brain diseases. The objective of this study is to asses the preserved artistry of a professional painter in spite of the presence of strokes affecting brain areas implicated in art expression. She had a neurologic evaluation and brain imaging after the stroke; painter-curators analyzed and compared the painter’s pictorial artwork created before and after the stroke. In spite of cerebellar, visuospatial, motor, cognitive, and functional deficits likely related to strokes affecting bilateral cerebellar, left occipital, and right temporal-occipital areas, the patient was able to maintain most of their artistic painting skills.. After a short period of functional recovery, our patient showed discrepancy among their impaired cerebellar cerebral functions in day activities and their preserved painting abilities.  相似文献   
10.
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