全文获取类型
收费全文 | 6577篇 |
免费 | 490篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 82篇 |
儿科学 | 149篇 |
妇产科学 | 100篇 |
基础医学 | 943篇 |
口腔科学 | 164篇 |
临床医学 | 638篇 |
内科学 | 1551篇 |
皮肤病学 | 85篇 |
神经病学 | 657篇 |
特种医学 | 261篇 |
外科学 | 1023篇 |
综合类 | 59篇 |
一般理论 | 5篇 |
预防医学 | 366篇 |
眼科学 | 131篇 |
药学 | 334篇 |
中国医学 | 8篇 |
肿瘤学 | 535篇 |
出版年
2023年 | 60篇 |
2022年 | 101篇 |
2021年 | 187篇 |
2020年 | 134篇 |
2019年 | 167篇 |
2018年 | 199篇 |
2017年 | 148篇 |
2016年 | 163篇 |
2015年 | 197篇 |
2014年 | 264篇 |
2013年 | 330篇 |
2012年 | 524篇 |
2011年 | 503篇 |
2010年 | 325篇 |
2009年 | 259篇 |
2008年 | 467篇 |
2007年 | 445篇 |
2006年 | 391篇 |
2005年 | 384篇 |
2004年 | 314篇 |
2003年 | 308篇 |
2002年 | 268篇 |
2001年 | 56篇 |
2000年 | 40篇 |
1999年 | 55篇 |
1998年 | 49篇 |
1997年 | 37篇 |
1996年 | 40篇 |
1995年 | 45篇 |
1994年 | 30篇 |
1993年 | 41篇 |
1992年 | 32篇 |
1991年 | 32篇 |
1990年 | 29篇 |
1989年 | 32篇 |
1988年 | 39篇 |
1987年 | 34篇 |
1986年 | 25篇 |
1985年 | 22篇 |
1984年 | 28篇 |
1983年 | 27篇 |
1982年 | 28篇 |
1981年 | 26篇 |
1980年 | 13篇 |
1979年 | 21篇 |
1978年 | 16篇 |
1975年 | 12篇 |
1974年 | 17篇 |
1973年 | 13篇 |
1972年 | 13篇 |
排序方式: 共有7091条查询结果,搜索用时 15 毫秒
161.
Stefan Dürschmid Andre Maric Marcel S. Kehl Robert T. Knight Hermann Hinrichs Hans-Jochen Heinze 《The Journal of neuroscience》2021,41(8):1727
Impulsive decisions arise from preferring smaller but sooner rewards compared with larger but later rewards. How neural activity and attention to choice alternatives contribute to reward decisions during temporal discounting is not clear. Here we probed (1) attention to and (2) neural representation of delay and reward information in humans (both sexes) engaged in choices. We studied behavioral and frequency-specific dynamics supporting impulsive decisions on a fine-grained temporal scale using eye tracking and MEG recordings. In one condition, participants had to decide for themselves but pretended to decide for their best friend in a second prosocial condition, which required perspective taking. Hence, conditions varied in the value for themselves versus that pretending to choose for another person. Stronger impulsivity was reliably found across three independent groups for prosocial decisions. Eye tracking revealed a systematic shift of attention from the delay to the reward information and differences in eye tracking between conditions predicted differences in discounting. High-frequency activity (175-250 Hz) distributed over right frontotemporal sensors correlated with delay and reward information in consecutive temporal intervals for high value decisions for oneself but not the friend. Collectively, the results imply that the high-frequency activity recorded over frontotemporal MEG sensors plays a critical role in choice option integration.SIGNIFICANCE STATEMENT Humans face decisions between sooner smaller rewards and larger later rewards daily. An objective benefit of losing weight over a longer time might be devalued in face of ice cream because they prefer currently available options because of insufficiently considering long-term alternatives. The degree of contribution of neural representation and attention to choice alternatives is not clear. We investigated correlates of such decisions in participants deciding for themselves or pretending to choose for a friend. Behaviorally participants discounted less in self-choices compared with the prosocial condition. Eye movement and MEG recordings revealed how participants represent choice options most evident for options with high subjective value. These results advance our understanding of neural mechanisms underlying decision-making in humans. 相似文献
162.
Alexey A. Shadrin PhD Sören Mucha PhD David Ellinghaus PhD Mary B. Makarious BSc Cornelis Blauwendraat PhD Ashwin A.K. Sreelatha MSc Antonio Heras-Garvin PhD Jinhui Ding PhD Monia Hammer PhD Alexandra Foubert-Samier MD Wassilios G. Meissner MD Olivier Rascol PhD Anne Pavy-Le Traon MD Oleksandr Frei PhD Kevin S. O'Connell PhD Shahram Bahrami PhD Stefan Schreiber MD Wolfgang Lieb MD Martina Müller-Nurasyid PhD Ulf Schminke MD Georg Homuth PhD Carsten O. Schmidt PhD Markus M. Nöthen MD Per Hoffmann PhD Christian Gieger PhD Gregor Wenning MD for the European Multiple System Atrophy Study Group J. Raphael Gibbs PhD Andre Franke PhD John Hardy PhD Nadia Stefanova PhD Thomas Gasser MD Andrew Singleton PhD Henry Houlden MD Sonja W. Scholz MD Ole A. Andreassen PhD Manu Sharma PhD 《Movement disorders》2021,36(2):449-459
163.
Suen Paulo J. C. Doll Sarah Batistuzzo Marcelo C. Busatto Geraldo Razza Lais B. Padberg Frank Mezger Eva Bulubas Lucia Keeser Daniel Deng Zhi-De Brunoni Andre R. 《European archives of psychiatry and clinical neuroscience》2021,271(1):101-110
European Archives of Psychiatry and Clinical Neuroscience - Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation intervention investigated for the treatment of... 相似文献
164.
Valentine Zimermann Vargas Caroline Motta Rodrigo Luiz Vancini Claudio Andre Barbosa de Lira Marilia Santos Andrade 《International Journal of Sports Physical Therapy》2021,16(3):827
BackgroundStudies have grouped different overhead sports and evaluated together the isokinetic strength of shoulder internal (IR) and external (ER) rotator muscles. However, muscular adaptations could be a consequence of the specific sport, and some strength imbalance between these muscles may exist as a consequence of the muscular demand unique to the sport. Therefore, grouping different overhead sports together may not be adequate.PurposeTo compare strength balance ratios between different overhead sports (volleyball, handball, swimming, judo, baseball, softball, functional movements performed at high-intensity interval training, and tennis) with a control athletic group (no overhead group).Study designCross-sectional study.MethodsA total of 237 athletes were submitted to isokinetic shoulder strength tests. The isokinetic concentric and eccentric peak torque values of shoulder internal IR and external ER rotator muscles were measured. Conventional (CR) and functional strength ratios (FR) were calculated.ResultsThere were no significant differences between the sports for the CR in the male group. Female softball athletes (90.4±13.6%) had a significantly higher CR than judo (67.3±6.9%), volleyball (74.9±15.9%), and swimming athletes (70.3±8.7%). In the female group, judo athletes had lower FR values (0.76±0.19) than soccer athletes (1.31±0.35), volleyball athletes (1.24±0.27), functional movements performed at high intensity (1.10±0.1), and softball athletes (1.40±0.39). Female handball athletes also had a lower FR (0.99±0.25) than soccer athletes (1.31±0.35) and softball athletes (1.40±0.39). Male handball (0.90±0.23), tennis (0.86±0.30), and judo (0.68±0.22) athletes had lower FR values than soccer athletes (1.20±0.21) and volleyball athletes (1.25±0.28).ConclusionsCR for males may be analyzed together, as there were no significant differences between them. However, for females, the CR for softball athletes should be analyzed individually. As there were several differences between the overhead sports according to the FRs, the authors suggest caution in grouping overhead athletes across multiple sports. These results could have important implications for the design of injury prevention and rehabilitation programs associated with the shoulder joint in overhead sports.Level of Evidence3 相似文献
165.
166.
Andre M. Samuel Matthew L. Webb Adam M. Lukasiewicz Daniel D. Bohl Bryce A. Basques Glenn S. Russo Vinay K. Rathi Jonathan N. Grauer 《Clinical orthopaedics and related research》2015,473(10):3297-3306
Background
Industry payments made to physicians by drug and device manufacturers or group purchasing organizations are now reported to the Centers for Medicare and Medicaid Services (CMS) as a part of the Physician Payments Sunshine Act. Initial reports from the program show that orthopaedic surgeons lead all physician specialties in total and average industry payments. However, before further discussion of these payments and their implications can take place, it remains to be seen whether these figures are a true reflection of the field of orthopaedic surgery in general, rather than the result of a few outlier physicians in the field. In addition, the nature and sources of these funds should be determined to better inform the national dialogue surrounding these payments.Questions/Purposes
We asked: (1) How do industry payments to orthopaedic surgeons compare with payments to physicians and surgeons in other fields, in terms of median payments and the Gini index of disparity? (2) How much do payments to the highest-receiving orthopaedic surgeons contribute to total payments? (3) What kind of industry payments are orthopaedic surgeons receiving? (4) How much do the highest-paying manufacturers contribute to total payments to orthopaedic surgeons?Materials and Methods
We reviewed the most recent version of the CMS Sunshine Act Open Payments database released on December 19, 2014, containing data on payments made between August 1, 2013 and December 31, 2013. Data on total payments to individual physicians, physician specialty, the types of payments made, and the manufacturers making payments were reviewed. The Gini index of statistical dispersion was calculated for payments made to orthopaedic surgeons and compared with payments made to physicians and surgeons in all other medical specialties. A Gini index of 0 indicates complete equality of payments to everyone in the population, whereas an index of 1 indicates complete inequality, or all income going to one individual.Results
A total of 15,376 orthopaedic surgeons receiving payments during the 5-month period were identified, accounting for USD 109,846,482. The median payment to orthopaedic surgeons receiving payments was USD 121 (interquartile range, USD 34–619). The top 10% of orthopaedic surgeons receiving payments (1538 surgeons) received at least USD 4160 and accounted for 95% of total payments. Royalties and patent licenses accounted for 69% of all industry payments to orthopaedic surgeons.Conclusions
Even as a relatively small specialty, orthopaedic surgeons received substantial payments from industry (more than USD 110 million) during the 5-month study period. Whether there is a true return of value from these payments remains to be seen; however, future ethical and policy discussions regarding industry payments to orthopaedic surgeons should take into account the large disparities in payments that are present and also the nature of the payments being made. It is possible that patients and policymakers may view industry payments to orthopaedic surgeons more positively in light of these new findings.Level of Evidence
Level III, Economic and Decision Analysis. 相似文献167.
A novel technique using three‐dimensionally documented biopsy mapping allows precise re‐visiting of prostate cancer foci with serial surveillance of cell cycle progression gene panel 下载免费PDF全文
168.
Antibacterial photodynamic treatment of periodontopathogenic bacteria with indocyanine green and near‐infrared laser light enhanced by TroloxTM 下载免费PDF全文
169.
Gallstone disease is a common gastrointestinal problem in day-to-day practice. The Old concept that a typical gallstone sufferer is fat, fertile, flatulent female of 50. This is partially true as the disease has been found in women soon after their first delivery who are thin and underweight and in males also. Conditions that favor the formation of cholesterol gallstones are super saturation of bile with cholesterol, kinetically favorable nucleation and presence of cholesterol crystals in the gall bladder long enough to agglomerate into a stone. Recent studies have defined the role of trace elements (Fe, Ca, Zn and Cu) and defective pH in the formation of gallstones. The aim of the study was to correlate iron-deficiency anemia with gallstone disease. To estimate the serum ferritin level as a diagnostic tool of iron deficiency anemia in patients with gallstone disease, this prospective study of 100 patients was conducted over a period of 24 months in the Department of General Surgery, Jaipur Golden Hospital, New Delhi, India. Serum cholesterol, iron and ferritin levels were compared in patients having gallstones and healthy individuals. A low serum iron level is a factor in bile super saturation with respect to cholesterol, leading to gallstone formation. 相似文献
170.
Physiological concentrations of ouabain rapidly inhibit prolactin release from the tilapia pituitary
Kajimura S Seale AP Hirano T Cooke IM Grau EG 《General and comparative endocrinology》2005,143(3):240-250
Ouabain, a cardiac glycoside and inhibitor of Na(+), K(+)-ATPase, is now believed to be a steroid hormone in mammals. We have recently identified ouabain immunoreactivity in the plasma of the tilapia, a euryhaline teleost. Changes in plasma concentrations of immunoreactive ouabain (20-40 pM) in response to salinity change were well correlated with the changes in plasma osmolality and cortisol. Our previous studies have shown that cortisol rapidly inhibits prolactin (PRL) release from the tilapia pituitary by suppressing intracellular Ca(2+) ([Ca(2+)]i) and cAMP. In the present study, low doses of ouabain (10-1000 pM) inhibited PRL release dose-dependently during 2-24 h of incubation. There was no effect on growth hormone (GH) release, except for a significant increase at 1000 pM during 8-24 h of incubation. Significant dose-related increases in PRL release were observed at higher doses of ouabain (100-1000 nM), whereas significant inhibition was seen in GH release at 1000 nM during 2-24h of incubation. Ouabain at 1-100 pM had no effect on Na(+), K(+)-ATPase activity of the pituitary homogenate. The enzyme activity was inhibited by higher concentrations of ouabain, 10% at 1 nM, 15% at 10 nM, 28% at 100 nM, and 45% at 1000 nM. Ouabain also attenuated stimulation of PRL release by the Ca(2+) ionophore, A23187, and by a combination of dibutyryl cAMP and a phosphodiesterase inhibitor, 3-isobutyl-1-methylxanthin. Intracellular Ca(2+) concentrations were monitored in the dispersed PRL cells with the Ca(2+)-sensitive dye, fura-2. Ouabain at 1 nM reversibly reduced [Ca(2+)]i within seconds, whereas 1 microM ouabain increased [Ca(2+)]i. A rapid reduction in [Ca(2+)]i was also observed when PRL cells were exposed to 1 microM cortisol, whereas there was no consistent effect at 1 nM. These results suggest that ouabain at physiological concentrations rapidly inhibits PRL release from the tilapia pituitary by suppressing intracellular Ca(2+) and cAMP metabolism. The stimulation of PRL release by high concentrations of ouabain (100-1000 nM) may result from an increase in [Ca(2+)]i, and subsequent depolarization due to the inhibition of Na(+), K(+)-ATPase activity. 相似文献