全文获取类型
收费全文 | 6692篇 |
免费 | 770篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 126篇 |
妇产科学 | 123篇 |
基础医学 | 762篇 |
口腔科学 | 515篇 |
临床医学 | 726篇 |
内科学 | 1237篇 |
皮肤病学 | 60篇 |
神经病学 | 490篇 |
特种医学 | 251篇 |
外科学 | 1296篇 |
综合类 | 155篇 |
一般理论 | 4篇 |
预防医学 | 638篇 |
眼科学 | 101篇 |
药学 | 298篇 |
中国医学 | 3篇 |
肿瘤学 | 634篇 |
出版年
2023年 | 47篇 |
2022年 | 60篇 |
2021年 | 123篇 |
2020年 | 101篇 |
2019年 | 161篇 |
2018年 | 178篇 |
2017年 | 143篇 |
2016年 | 146篇 |
2015年 | 145篇 |
2014年 | 244篇 |
2013年 | 304篇 |
2012年 | 432篇 |
2011年 | 423篇 |
2010年 | 280篇 |
2009年 | 223篇 |
2008年 | 359篇 |
2007年 | 429篇 |
2006年 | 326篇 |
2005年 | 321篇 |
2004年 | 292篇 |
2003年 | 273篇 |
2002年 | 250篇 |
2001年 | 208篇 |
2000年 | 218篇 |
1999年 | 177篇 |
1998年 | 83篇 |
1997年 | 61篇 |
1996年 | 51篇 |
1995年 | 62篇 |
1994年 | 53篇 |
1993年 | 30篇 |
1992年 | 108篇 |
1991年 | 115篇 |
1990年 | 82篇 |
1989年 | 68篇 |
1988年 | 82篇 |
1987年 | 102篇 |
1986年 | 66篇 |
1985年 | 73篇 |
1984年 | 55篇 |
1983年 | 60篇 |
1982年 | 35篇 |
1981年 | 39篇 |
1980年 | 35篇 |
1979年 | 51篇 |
1978年 | 47篇 |
1974年 | 28篇 |
1973年 | 46篇 |
1972年 | 26篇 |
1970年 | 26篇 |
排序方式: 共有7496条查询结果,搜索用时 15 毫秒
81.
Annika Molenaar Wei Yee Saw Linda Brennan Mike Reid Megan S. C. Lim Tracy A. McCaffrey 《Nutrients》2021,13(6)
Young adults are constantly exposed to energy-dense, nutrient-poor food and beverages, particularly through advertising. Exposure can influence poor food choices and negatively impact health. This study aimed to understand young adults’ attitudes and experiences associated with food-related advertisements, particularly on social media. This qualitative analysis involved n = 166 Australian 18 to 24-year-olds who were involved in a four-week online conversation on different areas relating to health, social media, and eating. Inductive thematic analysis was utilised on two forums on the recall and perceptions of food-related advertisements. Young adults commonly mentioned aspects of the marketing mix (promotion, product, price, and place) in food advertisements. Participants were more readily able to recall energy-dense, nutrient-poor food advertisements compared to healthy food-related advertisements. Digital advertisements were often discussed alongside the use of ad-blockers and algorithms which tailored their social media viewing to what they like. Participants felt constant exposure to unhealthy food advertisements hindered their ability to realise healthy eating behaviours and created feelings of guilt. This current analysis highlights the need to provide an advertising environment that appropriately motivates healthy eating and a food environment that allows healthy food to be the affordable and convenient option. 相似文献
82.
Psycho-Behavioural Segmentation in Food and Nutrition: A Systematic Scoping Review of the Literature
Eva L. Jenkins Samara Legrand Linda Brennan Annika Molenaar Mike Reid Tracy A. McCaffrey 《Nutrients》2021,13(6)
Inadequate dietary intakes are a key modifiable risk factor to reduce the risk of developing non-communicable diseases. To encourage healthy eating and behaviour change, innovative public health interventions are required. Social marketing, in particular segmentation, can be used to understand and target specific population groups. However, segmentation often uses demographic factors, ignoring the reasons behind why people behave the way they do. This review aims to explore the food and nutrition related research that has utilised psycho-behavioural segmentation. Six databases from were searched in June 2020. Inclusion criteria were: published 2010 onwards, segmentation by psycho-behavioural variables, outcome related to food or nutrition, and healthy adult population over 18 years. 30 studies were included; most were quantitative (n = 28) and all studies used post-hoc segmentation methods, with the tools used to segment the population varying. None of the segments generated were targeted in future research. Psycho-behavioural factors are key in understanding people’s behaviour. However, when used in post-hoc segmentation, do not allow for effective targeting as there is no prior understanding of behaviours that need to change within each segment. In future, we should move towards hybrid segmentation to assist with the design of interventions that target behaviours such as healthy eating. 相似文献
83.
J Davies B Srinivasan PA Brennan 《Annals of the Royal College of Surgeons of England》2021,103(1):e42
Lipomas are common benign tumours that can occur in most parts of the body. Lipomas arising from the deep temporal fat pad, found between the two layers of the deep temporal fascia, are rare, however; there has been only one documented case report to our knowledge. We describe a second case arising from the temporal fat pad in a patient treated at our unit, having previously reported the first one, and discuss the relevant anatomy and management. 相似文献
84.
85.
86.
87.
Emilio D. Poggio Joshua J. Augustine Susana Arrigain Daniel C. Brennan Jesse D. Schold 《American journal of transplantation》2021,21(8):2824-2832
Current short-term kidney post–transplant survival rates are excellent, but longer-term outcomes have historically been unchanged. This study used data from the national Scientific Registry of Transplant Recipients (SRTR) and evaluated 1-year and 5-year graft survival and half-lives for kidney transplant recipients in the US. All adult (≥18 years) solitary kidney transplants (n = 331,216) from 1995 to 2017 were included in the analysis. Mean age was 49.4 years (SD +/-13.7), 60% male, and 25% Black. The overall (deceased and living donor) adjusted hazard of graft failure steadily decreased from 0.89 (95%CI: 0.88, 0.91) in era 2000–2004 to 0.46 (95%CI: 0.45, 0.47) for era 2014–2017 (1995–1999 as reference). Improvements in adjusted hazards of graft failure were more favorable for Blacks, diabetics and older recipients. Median survival for deceased donor transplants increased from 8.2 years in era 1995–1999 to an estimated 11.7 years in the most recent era. Living kidney donor transplant median survival increased from 12.1 years in 1995–1999 to an estimated 19.2 years for transplants in 2014–2017. In conclusion, these data show continuous improvement in long-term outcomes with more notable improvement among higher-risk subgroups, suggesting a narrowing in the gap for those disadvantaged after transplantation. 相似文献
88.
89.
Sulfation of L-selectin ligands by an HEV-restricted sulfotransferase regulates lymphocyte homing to lymph nodes 总被引:13,自引:0,他引:13
Hemmerich S Bistrup A Singer MS van Zante A Lee JK Tsay D Peters M Carminati JL Brennan TJ Carver-Moore K Leviten M Fuentes ME Ruddle NH Rosen SD 《Immunity》2001,15(2):237-247
Lymphocytes home to lymph nodes, using L-selectin to bind specific ligands on high endothelial venules (HEV). In vitro studies implicate GlcNAc-6-sulfate as an essential posttranslational modification for ligand activity. Here, we show that genetic deletion of HEC-GlcNAc6ST, a sulfotransferase that is highly restricted to HEV, results in the loss of the binding of recombinant L-selectin to the luminal aspect of HEV, elimination of lymphocyte binding in vitro, and markedly reduced in vivo homing. Reactivity with MECA 79, an adhesion-blocking mAb that stains HEV in lymph nodes and vessels in chronic inflammatory sites, is also lost from the luminal aspects of HEV. These results establish a critical role for HEC-GlcNAc6ST in lymphocyte trafficking and suggest it as an important therapeutic target. 相似文献
90.
Embryonic development of four different subsets of cholinergic neurons in rat cervical spinal cord 总被引:1,自引:0,他引:1
P E Phelps R P Barber L A Brennan V M Maines P M Salvaterra J E Vaughn 《The Journal of comparative neurology》1990,291(1):9-26
The developmental stage at which a neuron becomes committed to a neurotransmitter phenotype is an important time in its ontogenetic history. The present study examines when choline acetyltransferase (ChAT) is first detected within each of four different subsets of cholinergic neurons previously identified in the cervical enlargement of the spinal cord: namely, motor neurons, partition cells, central canal cluster cells, and dorsal horn neurons. By examining the temporal sequence of embryonic development of these cholinergic neurons, we can infer the relationships between ChAT expression and other important developmental events. ChAT was first detected reliably on embryonic day 13 (E13) by both biochemical and immunocytochemical methods, and it was localized predominantly within motor neurons. A second group of primitive-appearing ChAT-positive cells was detected adjacent to the ventricular zone on E14. These neurons seemed to disperse laterally into the intermediate zone by E15, and, on the basis of their location, were tentatively identified as partition cells. A third group of primitive ChAT-immunoreactive cells was detected on E16, both within and around the ventral half of the ventricular zone. By E17, some members of this "U"-shaped group appeared to have dispersed dorsally and laterally, probably giving rise to dorsal horn neurons as well as dorsal central canal cluster cells. Other members of this group remained near the ventral ventricular zone, most likely differentiating into ventral central canal cluster cells. Combined findings from the present study and a previous investigation of neurogenesis (Phelps et al.: J. Comp. Neurol. 273:459-472, '88), suggest that premitotic precursor cells have not yet acquired the cholinergic phenotype because ChAT is not detectable until after the onset of neuronal generation for each of the respective subsets of cholinergic neurons. However, ChAT is expressed in primitive bipolar neurons located within or adjacent to the germinal epithelium. Transitional stages of embryonic development suggest that these primitive ChAT-positive cells migrate to different locations within the intermediate zone to differentiate into the various subsets of mature cholinergic neurons. Therefore, it seems likely that spinal cholinergic neurons are committed to the cholinergic phenotype at pre- or early migratory stages of their development. Our results also hint that the subsets of cholinergic cells may follow different migration routes. For example, presumptive partition cells may use radial glial processes for guidance, whereas dorsal horn neurons may migrate along nerve fibers of the commissural pathway. Cell-cell interactions along such diverse migratory pathways could play a role in determining the different morphological, and presumably functional, phenotypes expressed by spinal cholinergic neurons. 相似文献