全文获取类型
收费全文 | 5105篇 |
免费 | 653篇 |
国内免费 | 42篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 193篇 |
妇产科学 | 202篇 |
基础医学 | 521篇 |
口腔科学 | 137篇 |
临床医学 | 630篇 |
内科学 | 1209篇 |
皮肤病学 | 97篇 |
神经病学 | 487篇 |
特种医学 | 346篇 |
外科学 | 690篇 |
综合类 | 176篇 |
一般理论 | 12篇 |
预防医学 | 403篇 |
眼科学 | 60篇 |
药学 | 369篇 |
中国医学 | 1篇 |
肿瘤学 | 242篇 |
出版年
2023年 | 67篇 |
2022年 | 34篇 |
2021年 | 76篇 |
2020年 | 129篇 |
2019年 | 62篇 |
2018年 | 154篇 |
2017年 | 117篇 |
2016年 | 116篇 |
2015年 | 114篇 |
2014年 | 182篇 |
2013年 | 241篇 |
2012年 | 209篇 |
2011年 | 205篇 |
2010年 | 170篇 |
2009年 | 184篇 |
2008年 | 174篇 |
2007年 | 199篇 |
2006年 | 196篇 |
2005年 | 195篇 |
2004年 | 144篇 |
2003年 | 139篇 |
2002年 | 130篇 |
2001年 | 151篇 |
2000年 | 118篇 |
1999年 | 142篇 |
1998年 | 128篇 |
1997年 | 131篇 |
1996年 | 125篇 |
1995年 | 110篇 |
1994年 | 83篇 |
1993年 | 83篇 |
1992年 | 113篇 |
1991年 | 73篇 |
1990年 | 91篇 |
1989年 | 104篇 |
1988年 | 117篇 |
1987年 | 92篇 |
1986年 | 89篇 |
1985年 | 71篇 |
1984年 | 65篇 |
1983年 | 61篇 |
1982年 | 41篇 |
1981年 | 31篇 |
1980年 | 29篇 |
1979年 | 48篇 |
1978年 | 41篇 |
1977年 | 37篇 |
1976年 | 40篇 |
1975年 | 29篇 |
1967年 | 27篇 |
排序方式: 共有5800条查询结果,搜索用时 12 毫秒
21.
D M Mungas E H Trontel J Winegardner D S Brown T M Sweeney H A Walters 《Journal of clinical psychology》1979,35(4):822-832
Reported two studies that examined the efficacy of the Personality Research Form (PRF) as an outcome measure for interventions designed to increase social competence. In the first study (N = 83), the degree to which PRF scales can predict criteria frequently used in social skills training outcome research was examined, and the PRF was shown to be sensitive to such criteria. The second study (N = 24) assessed the relative degree to which the PRF scales and more frequently used outcome measures, including the above criteria, are affected by factors non-specific to social skills training interventions (suggestion for improvement). While three PRF scales were affected significantly, demand effects were much more pervasive on the other measures, which suggests that those measures can be used to obtain valid estimates of treatment effects only when experimental control of non-specific effects is possible. Two PRF scales, Affiliation and Exhibition, were shown to be both sensitive to criteria and resistant to demand effects, and as such may be useful as outcome measures in non-controlled clinical settings. 相似文献
22.
Mechanoafferent neurons innervating tail of Aplysia. I. Response properties and synaptic connections 总被引:4,自引:0,他引:4
Mechanical, chemical, or electrical stimulation of the tail elicits a short-latency (less than 1 s) tail-withdrawal reflex that is graded with the intensity of the stimulus. The tail-withdrawal reflex is not elicited by stimulation of parts of the body outside of the tail region. Mechanoafferent neurons innervating the tail are located in a small subcluster within a large, homogeneous group of medium-size (40-80 micron) cells on the ventrocaudal (VC) surface of each pleural ganglion. The tail sensory neurons within this large VC cluster are activated by tactile pressure or by electrical stimulation of discrete regions of the tail. They adapt slowly to maintained stimulation and sometimes respond to stimulus offset as well. Both mechanical and electrical stimuli produce responses that are graded with the intensity of the stimulus. Cells in the VC cluster appear to be primary mechanoreceptors because they have axons in peripheral nerves (including nerves innervating the tail), they exhibit action potentials lacking prepotentials in response to tactile stimulation, and these action potentials are still produced by cutaneous stimulation when peripheral and central chemical synaptic transmission is blocked. Stimulation of fields all over the body surface evokes synaptically mediated hyperpolarizing responses in individual mechanoafferent neurons that may represent afferent inhibition. Hyperpolarizing responses lasting many seconds can be produced by brief cutaneous stimuli. The mechanoafferent neurons innervating the tail region make strong monosynaptic connections to tail motor neurons in the ipsilateral pedal ganglion, and through these connections this subpopulation of the VC neurons appears to make a substantial contribution to the short-latency tail-withdrawal reflex. In addition, the combined excitatory receptive fields of these mechanoafferents match the excitatory receptive field of the tail-withdrawal reflex. Mechanoafferent neurons in the VC cluster that have receptive fields on other parts of the body (outside the excitatory receptive field of the tail-withdrawal reflex) have not been observed to make monosynaptic connections to the tail motor neurons. The neurons innervating the tail are reliably found in a discrete region within the larger VC cluster. In addition to this gross somatotopic organization, there is evidence of a finer level of somatotopic organization between the position of the excitatory receptive field on the tail and the position of the cell soma in the tail subcluster.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
23.
Mark J Elder MD FRACS FRACO Paul Hiscott PhD FRCS MRCPath John K.G Dart DM FRCS FRCOphth 《Human pathology》1997,28(12):1348-1354
Cicatricial conjunctivitis may be a sequel to systemic disorders (eg, Stevens-Johnson syndrome, cicatricial pemphigoid) or local disorders such as chemical burns. The cicatrisation is often associated with corneal epithelial changes that cause visual loss. These have been attributed to encroachment of the conjunctival epithelium over the cornea. However, the epithelial anomalies are poorly understood. We investigated the corneal epithelial changes in cicatricial conjunctivitis with an immunohistochemical study of intermediate filaments in normal and pathological specimens. Our results show that the normal corneal epithelium is immunoreactive for cytokeratin 3 (CK 3) but not cytokeratin 19 (CK 19), whereas normal conjunctival epithelium is CK 3 negative and CK 19 positive. Conjunctiva artificially transposed over the cornea (after therapeutic conjunctival flap reconstruction) retained the normal pattern of conjunctival cytokeratin expression (CK 3 negative, CK 19 positive). Conversely, the entire corneal epithelium exhibited the normal cytokeratin pattern (CK 3 positive, CK 19 negative) in 82% of Stevens-Johnson, 80% of cicatricial pemphigoid, and 69% of chemical burns specimens. The findings suggest that conjunctival encroachment is not responsible for the changes at the corneal surface in cicatricial conjunctivitis and that the abnormal corneal epithelium is derived from native corneal cells in these diseases. 相似文献
24.
Kenny Dorothy Xuanxian Hsueh Katherine Walters Ryan William Coté John Joseph 《Journal of community health》2021,46(6):1170-1176
Journal of Community Health - While human papilloma virus (HPV) vaccinations and Pap smear screenings are known to improve the survival rates and incidence of cervical cancer, refugee populations... 相似文献
25.
Social relatedness has recently become a primary focus of investigators in the field of autism. This shift to regarding disturbances in social relatedness as one of the defining manifestations of the disorder marks the movement of research on autistic disorder back to its origins, when Kanner first noted the "social and affective" symptoms of autism as pathognomonic. Currently, social impairment in autism is viewed as more pervasively characteristic of the disorder than any other single symptom. Further, there has been a recent proliferation of research designed to document the nature of social deficit in autism, and whether it is primarily affective, communicative, or cognitive in nature, or involves some combination of these three variables. This review summarizes recent research focusing on social relatedness in autism and discusses the implications of these findings. 相似文献
26.
The Relationship between Muscle Function and Ankle Stability 总被引:6,自引:0,他引:6
Lentell G Katzman LL Walters MR 《The Journal of orthopaedic and sports physical therapy》1990,11(12):605-611
The purpose of this investigation was to document the degree of weakness present in the medial and lateral muscle groups of individuals with chronically unstable ankles. Peak isometric and isokinetic torque measurements were collected bilaterally during the motion of inversion-eversion from 33 subjects, ages 17 to 54, reporting unilateral chronic lateral instability. Values were then compared between the involved and uninvolved sides. A modified Romberg test was also performed bilaterally to determine gross balance differences between the involved and uninvolved lower extremities. No significant difference in muscle strength was documented either isometrically or isokinetically, but balance differences were found between the two extremities in a majority of subjects. The findings suggest that muscular weakness is not a major contributing factor to the chronically unstable ankle. The findings do support the presence of proprioceptive deficits associated with this condition. Based on the results, proprioceptive activities should be a primary consideration in management of the chronically unstable ankle. J Orthop Sports Phys Ther 1990;11(12):605-611. 相似文献
27.
Gousse G Platt D Gannon R Walters K Chow M Nightingale CH 《Topics in hospital pharmacy management / Aspen Systems Corporation》1990,9(4):50-57
Developing clinical skills in pharmacy staff is a process that can enhance the services of a pharmacy department and improve the professional development and interest of the staff. Staff should be included in the development of a clinical philosophy and a training and ongoing development program that will achieve the desired goals should be planned. An MBO process may help to track the individual pharmacist's progress. Knowledgeable, motivated staff are the key ingredient in achieving success in providing pharmacy services. 相似文献
28.
Most health care organizations are using critical pathways in an attempt to reduce the variation in patient care, improve quality, enhance communication, and reduce costs. Virtually all of the critical path efforts to date have developed tables of treatments, medications, and so forth by day and have displayed them in a format known as a Gantt chart. This article presents a methodology for identifying the true "time-limiting" critical path, describes three additional methods for presenting the information--the network, precedent, and resource formats--and shows how these can significantly enhance current critical path efforts. 相似文献
29.
Knee joint kinematics during the sidestep cutting maneuver: potential for injury in women. 总被引:10,自引:0,他引:10
S G McLean R J Neal P T Myers M R Walters 《Medicine and science in sports and exercise》1999,31(7):959-968
PURPOSE: There is a paucity of data describing female lower limb biomechanics during "high risk" movements linked to noncontact ACL injury. This study compared, across gender, knee kinematics associated with sidestepping maneuvers to provide insight into why women display a significantly higher incidence of this injury than do men. METHODS: Thirty participants (16 men, 14 women) had bilateral knee joint kinematic data recorded while sidestepping. A custom software package (JTMOTION) quantified maximum, minimum, and range of motion during stance for each of the three clinical knee joint rotations (flexion/extension, adduction/abduction and external/internal rotation) over 20 (leg x condition x trial (5)) trials. RESULTS: Gender differences possessed limited clinical significance with all maximum values well within safe ranges of knee motion. Women did, however, display increased intertrial variability for axial rotation patterns during cutting compared with men. This variability was thought to be unaffected by gender, with experience level found statistically (P < 0.01) to be the major determinant of knee kinematic variability during sidestepping. Hence, the level of exposure to sidestep cutting may have a large impact on the subsequent risk of ACL injury when when one performs these maneuvers. CONCLUSIONS: Gender differences in knee motions during cutting did not contribute to the increased risk of noncontact ACL injury in women compared with men. The reasons for this increased incidence, therefore, remain unclear. The potential relationship between gender and other parameters linked to ACL injury such as joint geometry, ligament morphology, and physical conditioning requires further investigation. 相似文献
30.
Although nontoxic when administered alone, diethyldithiocarbamate (DDC) is known to enhance the dopamine-depleting effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in the mouse striatum. The purpose of the present study was twofold: (i) to carefully characterize the effects of DDC on MPTP-induced degeneration of dopaminergic neurons in substantia nigra pars compacta using unbiased, stereological cell counting techniques and (ii) to determine whether or not DDC can convert a nontoxic dose of MPTP into one which is clearly toxic on dopaminergic neurons in the substantia nigra. A single low dose of MPTP (15 mg/kg intraperitoneally (ip)) was used for these studies, which failed to induce any neurochemical or histological effects on the nigrostriatal system of C57BL/6 mice when administered alone. However, when animals were pretreated with DDC (400 mg/kg ip), the same dose of MPTP resulted in a 50% loss of neurons in the substantia nigra pars compacta, as well as a 70% reduction in striatal dopamine (DA). A 31% reduction of DA in the ventral mesencephalon was also seen. This combined regimen of DDC and MPTP was not significantly different from a maximally tolerated "toxic" dose of MPTP alone (15 mg/kg x 4, 1 h apart, ip). As expected, animals receiving DDC alone did not show any dopamine depletion nor nigral neuronal loss. The present study confirms previous work suggesting that DDC enhances MPTP-induced nigral cell loss and shows for the first time that DDC can "unmask" MPTP toxicity. These observations could have implications for theories on the cause of Parkinson's disease. 相似文献