全文获取类型
收费全文 | 522篇 |
免费 | 20篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 20篇 |
妇产科学 | 3篇 |
基础医学 | 29篇 |
口腔科学 | 7篇 |
临床医学 | 75篇 |
内科学 | 47篇 |
皮肤病学 | 1篇 |
神经病学 | 166篇 |
特种医学 | 98篇 |
外科学 | 7篇 |
综合类 | 33篇 |
预防医学 | 17篇 |
药学 | 30篇 |
中国医学 | 1篇 |
肿瘤学 | 8篇 |
出版年
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 10篇 |
2017年 | 5篇 |
2016年 | 2篇 |
2015年 | 9篇 |
2014年 | 13篇 |
2013年 | 29篇 |
2012年 | 21篇 |
2011年 | 18篇 |
2010年 | 26篇 |
2009年 | 29篇 |
2008年 | 13篇 |
2007年 | 33篇 |
2006年 | 18篇 |
2005年 | 23篇 |
2004年 | 10篇 |
2003年 | 17篇 |
2002年 | 14篇 |
2001年 | 14篇 |
2000年 | 13篇 |
1999年 | 10篇 |
1998年 | 11篇 |
1997年 | 14篇 |
1996年 | 15篇 |
1995年 | 10篇 |
1994年 | 15篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 10篇 |
1988年 | 17篇 |
1987年 | 16篇 |
1986年 | 21篇 |
1985年 | 10篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 3篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1969年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有543条查询结果,搜索用时 15 毫秒
31.
Research knowledge among parents of children participating in a randomized clinical trial 总被引:1,自引:0,他引:1
Vitiello B Aman MG Scahill L McCracken JT McDougle CJ Tierney E Davies M Arnold LE 《Journal of the American Academy of Child and Adolescent Psychiatry》2005,44(2):145-149
OBJECTIVE: Parental permission is required for child research, but parents' understanding of research aims and procedures has not been well documented. Parental research knowledge was assessed during a clinical trial in autism. METHOD: Parents of 101 children (age 5-17 years) with autism participating in a placebo-controlled trial of risperidone were given a questionnaire at the end of the study. RESULTS: Of the 95 parents completing the questionnaire, 99% knew of possible placebo assignment and that testing the medication efficacy was the main purpose of the investigators; 96% to 98% knew that research involved both risks and potential benefits, identified the study medication, and knew of their right to withdraw at any time; 90% to 95% knew of the medication's main side effects; 87% reported having been informed of possible alternatives to research participation; and 72% were aware that treatment was randomly assigned (whereas 27% reported that treatment was chosen based on individual needs to ensure best care). Parents with a college degree were more likely to recognize the random nature of treatment assignment. CONCLUSIONS: Overall, parents were highly knowledgeable of the main research components. About one fourth, however, seemed unaware that treatment was randomly determined and not personalized, suggesting that therapeutic misconception may affect some otherwise well-informed parents. 相似文献
32.
Parent-defined target symptoms respond to risperidone in RUPP autism study: customer approach to clinical trials 总被引:5,自引:0,他引:5
Arnold LE Vitiello B McDougle C Scahill L Shah B Gonzalez NM Chuang S Davies M Hollway J Aman MG Cronin P Koenig K Kohn AE McMahon DJ Tierney E 《Journal of the American Academy of Child and Adolescent Psychiatry》2003,42(12):1443-1450
OBJECTIVE: A consumer-oriented efficacy assessment in clinical trials should measure changes in chief complaint and consumer request (symptoms of most concern to patient/caregiver), which may be diluted in change scores of multisymptom scales. METHOD: In the Research Units on Pediatric Psychopharmacology (RUPP) Autism Network 8-week double-blind trial of risperidone versus placebo, the chief concerns of parents were collected at 0, 4, and 8 weeks (endpoint), in addition to standardized primary measures. Blinded clinical judges rated change from baseline to 4 and 8 weeks on a 9-point scale (1 = normalized, 5 = unchanged, 9 = disastrous); 94 participants had usable data. RESULTS: The most common symptoms identified by parents were tantrums, aggression, and hyperactivity. Interrater reliability was excellent. Mean ratings at endpoint were 2.8 +/- 1.2 on risperidone and 4.5 +/- 1.3 on placebo (p <.001). Ratings were collinear with Clinical Global Impression-Improvement and Aberrant Behavior Checklist Irritability subscale (primary dimensional measure). Effect size d was 1.4, compared to 1.2 on the Aberrant Behavior Checklist Irritability subscale. Effect sizes varied twofold by symptom category, largest for self-injury (2.11) and tantrums (1.95). CONCLUSIONS: Risperidone was superior to placebo in reducing symptoms of most concern to parents of autistic children with irritable behavior. Rating individualized participant-chosen target symptoms seems a reliable, sensitive, efficient, and consumer-friendly way to assess treatment effect and might have clinical application. 相似文献
33.
To understand better the relationships between blood-group antigens and bacterial constituents, examples of 23 gram-negative bacteria (representing the 10 genera Citrobacter, Edwardsiella, Enterobacter, Escherichia, Klebsiella, Proteus, Pseudomonas, Salmonella, Serratia, and Shigella) were tested for the presence of Kl-like antigens by hemagglutination-inhibition (HAI) assays against both IgG and IgM anti-Kl. Saline-suspended whole organisms, cell-free culture media, and disrupted organisms were used to test for such antigens in, on, and secreted by the microorganisms examined. Disrupted organisms of an isolate of Shigella sonnei nonspecifically inhibited IgG anti-Kl as well as IgG antibodies of the specificities Kpb, Fya, S, and c. However, only Escherichia coli 0125:B15, subtype 12808, had specific K1-like activity (no activity with other IgG [(k, Kpb, Jka, Fya, S, c] and IgM [A, B, M, P1] antibodies). Disrupted organisms inhibited IgM but not IgG anti-K1 in the HAI assay. A second subtype, E. coli 0125:B15, subtype 12809, exhibited no K1-like activity. These findings support the report of K1 activity in cell-free broth cultures of E. coli 0125:B15 (subtype unspecified). Thus, although not all E. coli 0125:B15 possesses K1-like activity, the finding of such activity in at least one E. coli subtype confirms the idea that bacterial components may play a role in the production of naturally occurring antibodies directed against non-ABO red cell antigens. 相似文献
34.
Lee AC Buckley MJ Pegman SJ Spiers H Scahill VL Gaffan D Bussey TJ Davies RR Kapur N Hodges JR Graham KS 《Hippocampus》2005,15(6):782-797
There has been considerable debate as to whether the hippocampus and perirhinal cortex may subserve both memory and perception. We administered a series of oddity tasks, in which subjects selected the odd stimulus from a visual array, to amnesic patients with either selective hippocampal damage (HC group) or more extensive medial temporal damage, including the perirhinal cortex (MTL group). All patients performed normally when the stimuli could be discriminated using simple visual features, even if faces or complex virtual reality scenes were presented. Both patient groups were, however, severely impaired at scene discrimination when a significant demand was placed on processing spatial information across viewpoint independent representations, while only the MTL group showed a significant deficit in oddity judgments of faces and objects when object viewpoint independent perception was emphasized. These observations provide compelling evidence that the human hippocampus and perirhinal cortex are critical to processes beyond long-term declarative memory and may subserve spatial and object perception, respectively. 相似文献
35.
First rotavirus vaccine licensed: Is there really a need? 总被引:6,自引:0,他引:6
RI Glass JS Bresee UD Parashar RC Holman JR Gentsch 《Acta paediatrica (Oslo, Norway : 1992)》1999,88(S426):2-8
The first rotavirus vaccine was licensed in the United States on 31 August 1998 for the prevention of severe rotavius diarrhea in children. Despite this landmark in new vaccines, many pediatricians and public health professionals in Europe are uncertain of the need for this vaccine for the routine immunization of infants. In Europe, ample evidence suggests that rotavirus is the most common cause of hospitalizations for severe diarrhea among children, but proper studies documenting the disease burden of rotavirus or th cost-effectiveness of a rotavirus immunization program have only been conducted in the United Kingdom following epidemiologic models used in the United States. All children are infected with rotavirus during their first few years of life, 30-50% of diarrheal hospitalizations among children <5 years are due to this agent, and, by the age of 5 years, between 1 in 40 and 1 in 77 children in Europe and the United States may be hospitalized for rotavirus. The first vaccine is a live, oral preparation combining four different serotypes of rotavirus and administered in three doses with other childhood immunizations. The good efficacy against severe rotavirus diarrhea, the low risk of adverse side effects and the positive costeffectiveness equation have led the two major immunization advisory groups in the U.S. to recommend this vaccine for routine use in American infants. European physicians and policymakers should re-examine the epidemiology and disease burden of rotavirus diarrhea now that an effective method of prevention is at hand. □ Childhood immunization, diseases, rotavirus, vaccination . 相似文献
36.
Kinnison ML; White RI Jr; Auster M; Hewes R; Mitchell SE; Shuman L; Gallacher D 《Radiology》1985,154(2):349-351
As an alternative to performing interventional radiology on inpatients under the care of internists and surgeons, the authors have established a cardiovascular radiology admitting service for well-screened, elective patients. The patients are admitted under the care of a cardiovascular radiology fellow and a staff physician. From April 1982 to December 1983, 133 patients were admitted to the service. Patients are cared for in a surgical ward or in an intermediate unit, as determined by the clinical situation. Advantages of this approach include a broader patient referral base, improved rapport with clinical colleagues and patients, improved follow-up data, and rapid evaluation and treatment, resulting in short hospital stays. The major disadvantages involve the commitment of time and staff necessary to provide quality care. The concept of the interventional radiologist in the role of admitting physician has important implications in terms of negotiations for additional financial compensation, commensurate with the skill and time required for performing these procedures and caring for the patient. 相似文献
37.
38.
Ocular MR imaging and spectroscopy: an ex vivo study 总被引:2,自引:0,他引:2
Gomori JM; Grossman RI; Shields JA; Augsburger JJ; Joseph PM; DeSimeone D 《Radiology》1986,160(1):201-205
Six eyes, freshly enucleated because of choroidal melanoma, were imaged on a 1.4-T superconducting magnetic resonance (MR) imaging system, and relaxation times were calculated for various parts of the eye. Unfixed fresh tissue samples were obtained for nuclear magnetic resonance spectroscopy (NMRS) on a variable-field (0.19-1.4 T) resistive unit. Detailed ocular anatomy was demonstrated. The NMRS relaxation times correlated with the MR imaging intensity patterns. The sensitivity of MR imaging to states of hydration provides an excellent window for appreciation of ocular anatomy. 相似文献
39.
Isthmic spondylolysis of the lumbar spine: MR imaging at 1.5 T 总被引:4,自引:0,他引:4
The appearance on magnetic resonance (MR) images of the normal pars interarticularis in 13 patients was reviewed and contrasted with that of the pars in eight patients with spondylolysis. The pars defect usually had an intermediate signal intensity with all pulse sequences; however, this intensity was somewhat variable depending on the exact ratio of cartilage, fat, and fluid within each bone defect. The pars defect was best seen with spin-echo 600/20 (repetition time msec/echo time msec) images. In three cases, out-of-phase images showed the spondylolysis best, because of extension of fat to the borders of the defect. The sagittal view allowed one to separate spondylolysis from the joint space of posterior facets since the orientation of the defects is perpendicular to the facets; thus, a common pitfall encountered with cross-sectional axial imaging techniques is avoided. MR imaging poorly delineated bone fragments around the defect, which may produce nerve root impingement, but revealed other numerous complications that occur with spondylolysis, including spondylolisthesis and herniation of the disk above. 相似文献
40.
Platelets secrete a low-molecular-weight protein, platelet factor four (PF-4), which binds to and neutralizes heparin and related sulfated glycosaminoglycans (GAGs). To examine the interactions of PF-4 with the GAGs present on endothelial cell surfaces, we incubated 125I-PF-4 with cell suspensions derived from confluent monolayers of cultured bovine aortic endothelium. Binding of 125I-PF-4 was inhibited by a 100-fold excess of nonradioactive PF-4 and varied with duration and temperature of incubation. At 4 degrees C, binding reached equilibrium at 20 minutes with kd = 2.87 mumol/L and Bmax of 63.83 pmol/10(5) cells. Binding capacity was reduced 83.4% by brief incubation of endothelial cells with trypsin and 46.67% by incubation with Flavobacterium heparinase, but was unchanged by chondroitin-ABCase treatment. At 37 degrees C, PF-4 was internalized by confluent monolayer of bovine aortic endothelial cells primarily through low-affinity adsorptive endocytosis. The internalized PF-4 was degraded to amino acids and small peptides with 50% conversion after 18-hour incubation. These studies demonstrate that a secreted platelet protein can bind to and enter endothelial cells. Binding may explain the rapid clearance of released PF-4 from plasma and could have important local effects on endothelial structure and function. 相似文献