全文获取类型
收费全文 | 6169篇 |
免费 | 517篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 200篇 |
妇产科学 | 137篇 |
基础医学 | 731篇 |
口腔科学 | 80篇 |
临床医学 | 622篇 |
内科学 | 973篇 |
皮肤病学 | 215篇 |
神经病学 | 621篇 |
特种医学 | 152篇 |
外科学 | 608篇 |
综合类 | 160篇 |
一般理论 | 7篇 |
预防医学 | 960篇 |
眼科学 | 69篇 |
药学 | 576篇 |
中国医学 | 3篇 |
肿瘤学 | 535篇 |
出版年
2022年 | 38篇 |
2021年 | 112篇 |
2020年 | 71篇 |
2019年 | 120篇 |
2018年 | 109篇 |
2017年 | 93篇 |
2016年 | 100篇 |
2015年 | 130篇 |
2014年 | 184篇 |
2013年 | 266篇 |
2012年 | 360篇 |
2011年 | 358篇 |
2010年 | 220篇 |
2009年 | 154篇 |
2008年 | 283篇 |
2007年 | 349篇 |
2006年 | 319篇 |
2005年 | 339篇 |
2004年 | 308篇 |
2003年 | 273篇 |
2002年 | 302篇 |
2001年 | 152篇 |
2000年 | 135篇 |
1999年 | 109篇 |
1998年 | 61篇 |
1997年 | 63篇 |
1996年 | 55篇 |
1995年 | 49篇 |
1994年 | 51篇 |
1993年 | 44篇 |
1992年 | 98篇 |
1991年 | 105篇 |
1990年 | 74篇 |
1989年 | 77篇 |
1988年 | 104篇 |
1987年 | 81篇 |
1986年 | 80篇 |
1985年 | 99篇 |
1984年 | 71篇 |
1983年 | 66篇 |
1982年 | 43篇 |
1981年 | 31篇 |
1980年 | 41篇 |
1979年 | 51篇 |
1978年 | 37篇 |
1974年 | 34篇 |
1973年 | 35篇 |
1972年 | 29篇 |
1971年 | 29篇 |
1968年 | 30篇 |
排序方式: 共有6690条查询结果,搜索用时 15 毫秒
1.
Christian Holm Hansen Shelley Lees Saidi Kapiga Janet Seeley Tony Barnett 《Global public health》2020,15(3):402-413
ABSTRACTMeasuring hope reliably and accurately remains an important research objective, not least in less prosperous settings where ‘holding on to hope’ may be critically important in the struggle against adverse life conditions. The State Hope Scale was designed for use in the US. Despite reported application in diverse cultures and using translations the scale has not been extensively validated outside US populations. This study contributes to a larger project exploring the measurement of hope and provides a critique of Snyder’s scale as used in a Tanzanian female population of 1021 urban microfinance participants. We evaluate the scale’s validity through assessment of the empirical distribution of scores, item response profiles, internal consistency and discriminatory ability. Participants mostly scored very high and many reached very near the maximum attainable score. Hardly any endorsed the negative half of the response scale. Several problems are discussed including poor discrimination and strong evidence of acquiescence response bias. We also found little association of the scale scores with hypothesised correlates of hope. Future improvements on the measurement of hope are recommended, especially in studies outside the narrow Western context in which the scale was devised. 相似文献
2.
Alexander S. Dakos Ellen M. Walker Huai Jiang Barry E. Stein Benjamin A. Rowland 《The European journal of neuroscience》2019,50(11):3702-3712
Unilateral lesions of visual cortex have the secondary consequence of suppressing visual circuits in the midbrain superior colliculus (SC), collectively producing blindness in contralesional space (“hemianopia”). Recent studies have demonstrated that SC visual responses and contralesional vision can be reinstated by a non‐invasive multisensory training procedure in which spatiotemporally concordant visual‐auditory pairs are repeatedly presented within the blind hemifield. Despite this recovery of visual responsiveness, the loss of visual cortex was expected to result in permanent deficits in that hemifield, especially when visual events in both hemifields compete for attention and access to the brain's visuomotor circuitry. This was evaluated in the present study in a visual choice paradigm in which the two visual hemifields of recovered cats were simultaneously stimulated with equally valent visual targets. Surprisingly, the expected disparity was not found, and some animals even preferred stimuli presented in the previously blind hemifield. This preference persisted across multiple stimulus intensity levels and there was no indication that animals were less aware of cues in the previously blind hemifield than in its spared counterpart. Furthermore, when auditory cues were combined with visual cues, the enhanced performance they produced on a visual task was no greater in the normal than in the previously blind hemifield. These observations suggest that the multisensory rehabilitation paradigm revealed greater inherent visual information processing potential in the previously blind hemifield than was believed possible given the loss of visual cortex. 相似文献
3.
4.
Joseph M Dhahbi Shelley X Cao Patricia L Mote Brian C Rowley John E Wingo Stephen R Spindler 《The Journal of nutrition》2002,132(1):31-37
Molecular chaperones assist in the biosynthesis and processing of proteins. Most chaperones are induced by physiological stresses. We have shown that dietary energy restriction decreases the mRNA and protein levels of many endoplasmic reticulum chaperones in the livers of mice. Here, we have investigated the response of chaperone mRNA to feeding. Control and 50% energy-restricted C3B10RF1 mice were deprived of food for 24 h, fed, and killed 0, 1.5, 5 or 12 h after feeding. Chaperone mRNAs were strongly induced as early as 1.5 h after feeding in control and energy-restricted mice. The integrated levels of these mRNA over 24 h were significantly lower in energy-restricted mice. The mRNA response to energy intake was mirrored over the course of days in the level of chaperone protein. A similar but smaller response to feeding was found in kidney and muscle. Puromycin and cycloheximide failed to inhibit the feeding response, suggesting that feeding releases chaperone expression from an unstable inhibitor. Studies with dibutyryl-cAMP- and glucagon-supplemented, normal and streptozotocin-diabetic mice suggest that glucagon and insulin may be mediators of the feeding response. Adrenalectomy enhanced the feeding induction, but dexamethasone administration had no effect. Thus, postprandial changes in insulin and glucagon may link chaperone gene expression to feeding, possibly in several tissues including liver. 相似文献
5.
6.
7.
Christopher Rowland 《Int J Health Serv》2004,34(3):555-556
A Tufts University study released in mid-2003 indicates that increasing numbers of clinical trials for U.S.-produced pharmaceutical are being conducted outside the United States, mainly by contract research organizations. This process speeds up clinical trials, but raises ethical issues of the possible coercion or exploitation of more vulnerable and naive patient populations. 相似文献
8.
9.
10.