全文获取类型
收费全文 | 3943篇 |
免费 | 405篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 142篇 |
妇产科学 | 64篇 |
基础医学 | 641篇 |
口腔科学 | 103篇 |
临床医学 | 516篇 |
内科学 | 648篇 |
皮肤病学 | 48篇 |
神经病学 | 456篇 |
特种医学 | 143篇 |
外科学 | 549篇 |
综合类 | 57篇 |
一般理论 | 2篇 |
预防医学 | 331篇 |
眼科学 | 65篇 |
药学 | 363篇 |
中国医学 | 3篇 |
肿瘤学 | 181篇 |
出版年
2022年 | 32篇 |
2021年 | 90篇 |
2020年 | 44篇 |
2019年 | 92篇 |
2018年 | 100篇 |
2017年 | 54篇 |
2016年 | 69篇 |
2015年 | 77篇 |
2014年 | 116篇 |
2013年 | 153篇 |
2012年 | 194篇 |
2011年 | 212篇 |
2010年 | 123篇 |
2009年 | 95篇 |
2008年 | 174篇 |
2007年 | 200篇 |
2006年 | 202篇 |
2005年 | 188篇 |
2004年 | 187篇 |
2003年 | 168篇 |
2002年 | 166篇 |
2001年 | 87篇 |
2000年 | 103篇 |
1999年 | 108篇 |
1998年 | 51篇 |
1997年 | 40篇 |
1996年 | 37篇 |
1995年 | 36篇 |
1994年 | 26篇 |
1993年 | 36篇 |
1992年 | 47篇 |
1991年 | 70篇 |
1990年 | 62篇 |
1989年 | 67篇 |
1988年 | 70篇 |
1987年 | 54篇 |
1986年 | 46篇 |
1985年 | 40篇 |
1984年 | 42篇 |
1983年 | 37篇 |
1982年 | 29篇 |
1981年 | 57篇 |
1980年 | 43篇 |
1979年 | 56篇 |
1978年 | 43篇 |
1977年 | 32篇 |
1976年 | 35篇 |
1975年 | 25篇 |
1974年 | 42篇 |
1969年 | 22篇 |
排序方式: 共有4355条查询结果,搜索用时 31 毫秒
1.
2.
3.
The glomerular layer of the olfactory bulb contains a substantial population of dopaminergic neurons. We determined the quantity and location of D1 and D2 dopamine receptors which are the presumed targets of these neurons. Binding of the D1 selective ligand [3H]SCH23390 was slightly above background and was distributed through all layers of the bulb except the olfactory nerve layer. In contrast there were relatively high levels of [3H]spiperone binding to D2 DA receptors in the glomerular and olfactory nerve layers. The presence of relatively high concentrations of D2 DA receptors in both the nerve layer and glomerular layer suggests the novel hypothesis that these receptors may be localized on terminals of the olfactory nerve. 相似文献
4.
Jessica Swoboda DDS H. Asuman Kiyak MA PhD Rigmor E. Persson DDS MSD G. Rutger Persson DDS PhD David K. Yamaguchi PhD Michael I. MacEntee LDS FRCD© PhD Christopher C.L. Wyatt BSc DMD MSc 《Special care in dentistry》2006,26(4):137-144
There is limited information regarding oral health status and other predictors of oral health‐related quality of life. An association between oral health status and perceived oral health‐related quality of life (OHQOL) might help clinicians motivate patients to prevent oral diseases and improve the outcome of some dental public health programs. This study evaluated the relationship between older persons' OHQOL and their functional dentition, caries, periodontal status, chronic diseases, and some demographic characteristics. A group of 733 low‐income elders (mean age 72.7 ISD=4.71, 55.6% women, 55.1% members of ethnic minority groups in the U.S. and Canada) enrolled in the TEETH clinical trial were interviewed and examined as part of their fifth annual visit for the trial. OHQOL was measured by the Geriatric Oral Health Assessment Index (GOHAI); oral health and occlusal status by clinical exams and the Eichner Index; and demographics via interviews. Elders who completed the four‐year assessment had an average of 21.5 teeth (SD=6.9). with 8.5 occluding pairs (SD=4.6), and 32% with occlusal contacts in all four occluding zones. Stepwise multiple regressions were conducted to predict total GOHAI and its subscores (Physical, Social, and Worry). Functional dentition was a less significant predictor than ethnicity and being foreign‐bom. These variables, together with gender, years since immigrating, number of carious roots, and periodontal status, could predict 32% of the variance in total GOHAI, 24% in Physical, 27% in Social, and 21 % in the Worry subscales. These findings suggest that functional dentition and caries influence older adults' OHQOL, but that ethnicity and immigrant status play a larger role. 相似文献
5.
6.
7.
Wolfgang Lutz Michael J. Lambert S. Cory Harmon Armita Tschitsaz Eva Schürch Niklaus Stulz 《Clinical psychology & psychotherapy》2006,13(4):223-232
Empirical methods have been found to be superior to clinical judgment for the purpose of correctly identifying patients at risk for treatment failure and, hence, to enhance psychotherapy outcomes. The development and evaluation of an empirical approach aimed at supporting clinical decisions during the course of psychotherapy is described. The tool provides predictions based on a patient‐specific sampling strategy called the nearest neighbors method and on growth curve approaches to model an expected treatment course for each patient. Using session‐by‐session data from an outpatient center in the US (N = 4365), this new empirically derived decision model was evaluated and compared with a clinically based approach loosely based on an adaptation of clinically significant change concepts. The empirically derived decision system was found to be superior to the rational clinically based one in almost all measures of prediction accuracy, indicating its potential to identify patients at risk for treatment failure. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
8.
Tushar M Ranchod Daynia E Ballot Alma M Martinez Barbara J Cory Victor A Davies J Colin Partridge 《Suid-Afrikaanse tydskrif vir geneeskunde》2004,94(11):913-916
BACKGROUND: Little is known about parental experience and decision making with regard to premature infants requiring intensive care in developing countries. We undertook this study to characterise parents' experience of physician counselling and their role in making life-support decisions for very low-birth-weight (VLBW) (birth weight < 1 501 g) infants born in South Africa's public-sector neonatal intensive care units (NICUs). METHODS: Parents of surviving VLBW infants treated in three Johannesburg-area public hospitals and attending follow-up clinics in August 2001 were interviewed regarding their experience of perinatal counselling on outcomes (pain, survival, disability), perception of actual and optimal decision making, and satisfaction with NICU communication. RESULTS: Parents of 51 infants were interviewed. Seventy-five per cent of parents reported antenatal counselling by physicians on at least one perinatal topic (severe disability, pain, death, finances or religious/moral considerations). The majority of parents (> 60%) who received counselling thought that these topics had been discussed adequately. Most parents reported that doctors had the primary decision-making role, either without consulting them (41%) or after consulting them (37%). Joint decision making was rare (14%). Parents wanted more input in life-support decisions than they reported being given. CONCLUSION: Counselling is not consistently provided in public-sector hospitals in Johannesburg. Parents of premature infants want a larger share in NICU decision making than they currently experience. Most parents were satisfied with communication later during their infant's hospitalisation. South Africa presents a unique opportunity to study the use of advanced medical technologies in a nation with marked disparities in access to care. 相似文献
9.
We previously reported that initiation of metamorphosis of larvae of Lytechinus pictus is negatively regulated by nitric oxide (NO) and cGMP. We have examined the expression of nitric oxide synthase (NOS) and cGMP in cells of the developing larva. A section of the post-oral ciliary band of feeding larvae includes neural cells defined by their expression of both NOS and the echinoderm neural-specific antibody 1E11. These neurons project processes to the pre-oral neuropile during larval development. Larvae regenerated this section of the ciliary band after its excision, complete with NOS-defined neurons that projected again to the pre-oral neuropile. Excision of ectoderm containing the post-oral ciliary band prevented a behavioral and morphogenetic response of competent larvae to biofilm, and delayed initiation of metamorphosis. Elevated cGMP levels were detected in several larval and juvenile cell types prior to metamorphosis. Treatment of larvae with ODQ, an inhibitor of soluble guanylate cyclase, decreased cGMP levels and induced metamorphosis while a generator of NO counteracted this effect, indicating inhibition of metamorphosis by NO operates via interaction with soluble guanylate cyclase. We discuss these observations, proposing that the NOS-defined neurons in the post-oral ciliary band have a chemosensory function during settlement and metamorphosis that involves morphologically specialized ectoderm and manipulation of fluid flow. We provide a tentative cellular model of how environmental signals may be transduced into a metamorphic response. 相似文献
10.
David H. Sutherland Kenton R. Kaufman Marilynn P. Wyatt Henry G. Chambers 《Gait & posture》1996,4(4):269-279
Botulinum A toxin (BOTOX®) was injected into the gastrocnemius muscle of 26 cerebral palsy subjects with equinus gait. All subjects were equinus walkers without fixed contracture of the triceps-surae muscle. Injections were performed at 3 month intervals, if needed, as determined by the treating clinician. There were 14 subjects with spastic hemiplegia, 11 subjects with spastic diplegia and 1 subject with spastic quadriplegia. In the case of those subjects with bilateral equinus gait the dose was divided and given into both the right and left gastrocnemius muscle. Gait analysis data was collected prior to the first injection and subsequently at 3 month intervals for 1 year. Kinematic and electromyographic data was obtained. This data was analyzed to provide objective information about the outcome of treatment. Four subjects moved away and were lost to follow-up. Seven subjects left the study to have surgery. The data collected revealed statistically significant improvements in dynamic ankle dorsiflexion in both stance and swing phases, stride length, and electromyography of the tibialis anterior. There were no complications. While the results of this study are promising, additional prospective studies are needed to determine the feasibility of preventing muscle contractures over a longer time period. Furthermore, there is a need for inclusion of other muscles in future research. Future research should also compare BOTOX® treatment with alternative methods of dealing with muscle spasticity such as: casting, orthotic devices, physical therapy, selective dorsal rhizotomy, and surgical lengthening. 相似文献