全文获取类型
收费全文 | 1297篇 |
免费 | 23篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 23篇 |
妇产科学 | 17篇 |
基础医学 | 345篇 |
口腔科学 | 36篇 |
临床医学 | 145篇 |
内科学 | 76篇 |
皮肤病学 | 8篇 |
神经病学 | 132篇 |
特种医学 | 34篇 |
外科学 | 53篇 |
综合类 | 53篇 |
预防医学 | 169篇 |
眼科学 | 142篇 |
药学 | 54篇 |
中国医学 | 11篇 |
肿瘤学 | 9篇 |
出版年
2023年 | 12篇 |
2022年 | 30篇 |
2021年 | 15篇 |
2020年 | 25篇 |
2019年 | 29篇 |
2018年 | 25篇 |
2017年 | 26篇 |
2016年 | 10篇 |
2015年 | 15篇 |
2014年 | 48篇 |
2013年 | 85篇 |
2012年 | 62篇 |
2011年 | 88篇 |
2010年 | 56篇 |
2009年 | 82篇 |
2008年 | 86篇 |
2007年 | 79篇 |
2006年 | 76篇 |
2005年 | 61篇 |
2004年 | 37篇 |
2003年 | 37篇 |
2002年 | 25篇 |
2001年 | 32篇 |
2000年 | 30篇 |
1999年 | 15篇 |
1998年 | 14篇 |
1997年 | 13篇 |
1996年 | 13篇 |
1995年 | 15篇 |
1994年 | 13篇 |
1993年 | 13篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 11篇 |
1989年 | 4篇 |
1988年 | 13篇 |
1987年 | 10篇 |
1986年 | 10篇 |
1985年 | 12篇 |
1984年 | 16篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1980年 | 4篇 |
1979年 | 7篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 4篇 |
1973年 | 5篇 |
排序方式: 共有1329条查询结果,搜索用时 20 毫秒
1.
目的探讨儿童期创伤与抑郁特质之间的中介和调节机制,为开展相关研究和干预提供参考。方法2017-2018年采用整群抽样的方法,抽取湖南某高校大一年级2 786名学生完成儿童期创伤问卷、状态特质抑郁问卷、自动思维问卷和特质应对方式问卷的调查。结果儿童期创伤、自动思维和消极应对对抑郁特质起正向的预测作用,积极应对对抑郁特质起负向的预测作用(β值分别为0.12,0.43,0.14,-0.33,P值均<0.05)。自动思维中介儿童期创伤与抑郁特质之间的关系(Bootstrapping法的95%CI为0.03~0.06)。消极应对分别调节了儿童期创伤与自动思维和儿童期创伤与抑郁特质之间的关系(P值均<0.05)。结论儿童期创伤影响抑郁特质,其关系受到应对方式和自动思维的影响。 相似文献
2.
Purpose: To test the effectiveness of a school-based, nurse-facilitated support group in increasing perceptions of scholastic competence, social acceptance, behavioral conduct, perceived athletic competence, perceived physical appearance, and perceived global self-worth in preadolescents diagnosed with attention deficit disorder (ADD) or attention deficit hyperactivity disorder (ADHD).
Design: A quasi-experimental design with 65 preadolescents diagnosed with ADD or ADHD in an upper-middle class community in the United States.
Methods: Participants randomly assigned to either the control or experimental group completed Harter's Self-Perception Profile for Children instrument at the beginning of the study and 4 weeks later. Students in the experimental condition participated in a school-nurse facilitated support group which met twice weekly for 4 weeks.
Findings: Participants in the support group had increased scores on each of the six subscales, with significant increases on four of the subscales, including perceived social acceptance, perceived athletic competence, perceived physical appearance, and perceived global self-worth.
Conclusion: Participation in a school-based, nurse-led support group was positively associated with perception of self-worth in preadolescents diagnosed with ADD or ADHD. 相似文献
Design: A quasi-experimental design with 65 preadolescents diagnosed with ADD or ADHD in an upper-middle class community in the United States.
Methods: Participants randomly assigned to either the control or experimental group completed Harter's Self-Perception Profile for Children instrument at the beginning of the study and 4 weeks later. Students in the experimental condition participated in a school-nurse facilitated support group which met twice weekly for 4 weeks.
Findings: Participants in the support group had increased scores on each of the six subscales, with significant increases on four of the subscales, including perceived social acceptance, perceived athletic competence, perceived physical appearance, and perceived global self-worth.
Conclusion: Participation in a school-based, nurse-led support group was positively associated with perception of self-worth in preadolescents diagnosed with ADD or ADHD. 相似文献
3.
Ambroise Martin 《Cahiers de Nutrition et de Diététique》2007,42(2):97-102
Nutritional reference intakes are build to cover the nutritional needs of the majority of the “normal“ population in a “normal“ environment. Much work is needed to define references for extreme situations. Beside extreme situations such as pathology, under or over nutrition, the study of other extreme conditions could lead to useful insights in pathophysiological mechanisms. Man adaptation to cold temperatures, altitude or spatial flights leads to the development of experimental models, the utility of which goes far beyond the studied conditions: the regulation of appetite and of the metabolisms of proteins, carbohydrates or calcium provides interesting examples. 相似文献
4.
The capacity for short-term adaptation is a well-established property of the horizontal (H) and vertical (V) components of saccades. It allows these directional components, which clearly serve the goal of foveation, to maintain their precision even under changing circumstances. Torsional (T) saccade components, on the other hand, which deal with the orientation of the target on the fovea, have hardly been investigated in adaptation experiments. They appear to be severely restricted by Listing's law during fixations and saccades. The main purpose of Listing's law is far from obvious but could be visual or oculomotor. Better knowledge of the adaptive capacity of the saccadic system in the torsional direction could throw new light on the functional significance of this interesting neural strategy. To study short-term plasticity in the torsional components of saccades, binocular 3D-eye positions were measured, using magnetic search foils. Five normal human subjects were instructed to make uni-directional refixation saccades, while they viewed a large visual scene. To induce a change in the torsional component, the complete stimulus was rapidly rotated during these saccades. We thoroughly investigated the torsional responses of the saccadic system, to see if any short-term adaptive response in torsional direction was induced, in which case the notion of a visual purpose for Listing's law would be strengthened. In none of our experiments, however, did we find any clear adaptive response in torsional direction. To further investigate the reliability of this result and to ascertain that our experimental conditions allowed classical gain adaptation, we also did experiments designed to achieve a combination of torsional adaptation and classic gain shortening in one of the directional components. While gain adaptation was very obvious, none of the experiments provided evidence for a short-term effect in torsion. We conclude that our experiments do not support a purely visual basis for Listing's law. 相似文献
5.
高中生自我和谐与应对方式及其相互关系 总被引:2,自引:0,他引:2
目的了解高中生自我和谐、应对方式的特征及其相互关系,为开展心理健康教育提供依据。方法采用自我和谐量表及简易应对方式问卷,对755名高中生进行问卷调查。结果高中生总分和各因子分在性别、是否独生子女、城乡、文理科等方面差异均无统计学意义,自我和谐总分存在年级差异;积极应对和消极应对维度在性别、是否独生子女、城乡、文理科等方面差异均无统计学意义,消极应对维度存在年级差异。应对方式与自我和谐总分及分量表得分存在不同程度的相关。结论采用积极应对方式有助于促进高中生的自我和谐,而消极应对方式对自我和谐存在不利影响。 相似文献
6.
N. Pélicier 《Annales médico-psychologiques》2007,165(2):136-140
The psychiatrists practice in consultation-liaison psychiatry is peculiar. The work requires him/her to adapt to the terrain: to seize the opportunity of intervening in one way or another he will be obliged simultaneously to abandon his dual position with the patient, to integrate into the medical team and, also, to take into account the physiological specificity of the illness and its psycho-social repercussions. Whether on a formal or informal register all is subtle and delicate in these liaison interventions. Cancer and cancerology even add their own specificity and constraints to this mode of exercise. Consultation-liaison remains, more particularly in cancerology, a practice of mediation and of conciliation confronted to the problematics of risk, of incertitude and of finiteness. 相似文献
7.
Renal adaptation to changes in inorganic sulfate intake and age was studied by comparing sulfate uptake by proximal tubule
brush border membrane vesicles (BBMV) from guinea pigs of different ages on relatively high- or low-sulfate diets. Adult (>60
days) or young guinea pigs (<25 days) were fed either a control diet (0.28% sulfur content), a sulfur-free diet, or a high-sulfate
diet. After 5 days on the diet, BBMV were obtained and kinetic analysis of 35sulfate uptake was determined. In adult guinea pigs, the low-sulfate diet produced a significant increase in apparent maximal
velocity (V
max). In young guinea pigs, a lower sulfate intake did not appreciably increase V
max, but a high-sulfate intake produced a reduction in V
max. The affinity for sulfate (K
m) was not changed in either age group. The dietary sulfate intake did not alter sodium gradient dependent-D-glucose or 32phosphate V
max. In conclusion, our data indicate that renal inorganic sulfate BBMV uptake is regulated and responds to conditions of increased
need (i.e., during the growth phase in young animals and during periods of decreased sulfate availability in adult animals)
by increasing BBMV V
max.
Received September 9, 1994; received in revised form March 18, 1997; accepted March 20, 1997 相似文献
8.
用扫描电镜直接观察及硅橡胶一环氧树脂扫描电镜复型技术观察银汞合金、EB复合树脂、玻璃离子粘固粉体外充填与釉质、牙骨/本质壁的边缘密合度。结果表明,与牙体组织呈化学性结合的玻璃离子粘固粉与釉质、牙骨/本质壁的密合度好,两壁之间无差别;EB复合树脂与釉质壁的边缘密合度与玻璃离子粘固粉相似,其缝隙明显小于牙骨/本质壁;银汞合金与釉质壁、牙骨/本质壁的边缘密合度差,且两壁之间无明显差别。 相似文献
9.
Simulation of space adaptation syndrome on earth 总被引:2,自引:0,他引:2
W. J. Ockels R. Furrer E. Messerschmid 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1990,79(3):661-663
Summary The three Spacelab D-1 Scientist Astronauts were exposed to a 11/2 h 3 g centrifuge run in the supine position, resulting in a linear 3 g acceleration in the x-direction. They used their space experience to evaluate their readapting to normal gravity and compared their observations with Space Adaptation Syndrome. After the centrifuge runs, the vestibular visual system appeared to be modified in a very specific and reproducible manner. Readapting to the normal 1 g environment took at least 6 h. During this period there was a striking similarity to the astronaut's experience during adaptation to weightlessness in space. A series of vestibular tests were then performed, confirming these subjective findings. 相似文献
10.
Helen Cohen Bernard Cohen Theodore Raphan Walter Waespe 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1992,90(3):526-538
Summary We habituated the dominant time constant of the horizontal vestibuloocular reflex (VOR) of rhesus and cynomolgus monkeys by repeated testing with steps of velocity about a vertical axis and adapted the gain of the VOR by altering visual input with magnifying and reducing lenses. After baseline values were established, the nodulus and ventral uvula of the vestibulocerebellum were ablated in two monkeys, and the effects of nodulouvulectomy and flocculectomy on VOR gain adaptation and habituation were compared. The VOR time constant decreased with repeated testing, rapidly at first and more slowly thereafter. The gain of the VOR was unaffected. Massed trials were more effective than distributed trials in producing habituation. Regardless of the schedule of testing, the VOR time constant never fell below the time constant of the semicircular canals (5 s). This finding indicates that only the slow component of the vestibular response, the component produced by velocity storage, was habituated. In agreement with this, the time constant of optokinetic after-nystagmus (OKAN) was habituated concurrently with the VOR. Average values for VOR habituation were obtained on a per session basis for six animals. The VOR gain was adapted by natural head movements in partially habituated monkeys while they wore ×2.2 magnifying or ×0.5 reducing lenses. Adaptation occurred rapidly and reached about ±30%, similar to values obtained using forced rotation. VOR gain adaptation did not cause additional habituation of the time constant. When the VOR gain was reduced in animals with a long VOR time constant, there were overshoots in eye velocity that peaked at about 6–8 s after the onset or end of constant-velocity rotation. These overshoots occurred at times when the velocity storage integrator would have been maximally activated by semicircular canal input. Since the activity generated in the canals is not altered by visual adaptation, this finding indicates that the gain element that controls rapid changes in eye velocity in the VOR is separate from that which couples afferent input to velocity storage. Nodulouvulectomy caused a prompt and permanent loss of habituation, returning VOR time constants to initial values. VOR gain adaptation, which is lost after flocculectomy, was unaffected by nodulouvulectomy. Flocculectomy did not alter habituation of the VOR or of OKAN. Using a simplified model of the VOR, the decrease in the duration of vestibular nystagmus due to habituation was related to a decrement in the dominant time constant of the velocity storage integrator (1/h
0). Nodulouvulectomy, which reversed habituation, would be effected by decreasing h
0, thereby increasing the VOR time constant. Small values of h
0 would cause velocity storage to approach an ideal integrative process, leading the system to become unstable. By controlling the VOR time constant through habituation, the nodulus and uvula can stabilize the slow component of the VOR. VOR gain adaptation was related to a modification of the direct vestibular path gain g
1, without altering the coupling to velocity storage g
0 or its time constant (1/h
0). The mismatched direct- and indirect-pathway gains simulated the overshoots in the dynamic response to a step in velocity, that were observed experimentally. We conclude that independent distributed elements in the VOR modify its dynamic response, under control of separate parts of the vestibulocerebellum. 相似文献