全文获取类型
收费全文 | 1763篇 |
免费 | 147篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 41篇 |
妇产科学 | 26篇 |
基础医学 | 223篇 |
口腔科学 | 34篇 |
临床医学 | 220篇 |
内科学 | 341篇 |
皮肤病学 | 22篇 |
神经病学 | 168篇 |
特种医学 | 44篇 |
外科学 | 336篇 |
综合类 | 10篇 |
一般理论 | 2篇 |
预防医学 | 181篇 |
眼科学 | 20篇 |
药学 | 124篇 |
中国医学 | 5篇 |
肿瘤学 | 110篇 |
出版年
2023年 | 8篇 |
2022年 | 17篇 |
2021年 | 30篇 |
2020年 | 33篇 |
2019年 | 45篇 |
2018年 | 40篇 |
2017年 | 63篇 |
2016年 | 47篇 |
2015年 | 48篇 |
2014年 | 44篇 |
2013年 | 84篇 |
2012年 | 119篇 |
2011年 | 112篇 |
2010年 | 57篇 |
2009年 | 68篇 |
2008年 | 100篇 |
2007年 | 108篇 |
2006年 | 103篇 |
2005年 | 106篇 |
2004年 | 87篇 |
2003年 | 78篇 |
2002年 | 68篇 |
2001年 | 25篇 |
2000年 | 27篇 |
1999年 | 22篇 |
1998年 | 12篇 |
1997年 | 18篇 |
1996年 | 15篇 |
1995年 | 14篇 |
1994年 | 13篇 |
1993年 | 10篇 |
1992年 | 22篇 |
1991年 | 16篇 |
1990年 | 19篇 |
1989年 | 16篇 |
1988年 | 18篇 |
1987年 | 15篇 |
1986年 | 16篇 |
1985年 | 13篇 |
1984年 | 19篇 |
1983年 | 29篇 |
1981年 | 7篇 |
1979年 | 11篇 |
1978年 | 12篇 |
1976年 | 7篇 |
1974年 | 10篇 |
1973年 | 7篇 |
1972年 | 6篇 |
1969年 | 7篇 |
1966年 | 6篇 |
排序方式: 共有1913条查询结果,搜索用时 312 毫秒
1.
2.
Neurological dysfunction of the bladder in workers exposed to dimethylaminopropionitrile 总被引:1,自引:0,他引:1
Neurogenic bladder dysfunction, characterized by hesitancy, need to strain, decreased stream, and increased duration of urination, developed in 104 (63%) of 166 employees working in the manufacture of polyurethane foam. Highest rates of illness (69%) occurred in production workers, and no illness occurred in office or warehouse workers. Onset of the epidemic coincided with introduction of a catalyst, dimethylaminopropionitrile (DMAPN), and monthly case incidence rates increased as DMAPN use increased. Outbreak ceased abruptly when DMAPN use was stopped. Of eight patients who underwent neurourologic testing during recovery, seven lacked either detrusor reflex or normal sensation of bladder filling; seven had a subclinical sensory abnormality; three had prolonged sacral-evoked responses; and two of these three had limb motor neuropathies. Dimethylaminopropionitrile is unique among known neurotoxins in producing urinary symptoms more frequently than limb nerve symptoms. 相似文献
3.
Scott A Fields Elizabeth Morrison Ernie Yoder Kevin Krane Thomas Agresta Rich Esham Frederick McCurdy Jonathan Rosen James Shumway 《Academic medicine》2002,77(6):543-546
PURPOSE: Chart notes are used to support billing codes under the evaluation and management guidelines of the Health Care Financing Administration (HCFA), in addition to serving as a record of the visit. To better understand the effect of the HCFA documentation guidelines, the authors collected data on how the guidelines affect participation by university- and community-based faculty in clinical education programs. METHOD: In 2000, the authors sent six copies of their questionnaire to the associate deans of the 125 U.S. medical schools and requested they distribute them to all core clerkship directors. The questionnaire consisted of multiple-choice and short-answer questions regarding documentation of medical visits, participation of community-based faculty, understanding of HCFA documentation guidelines, and effects on education programs. RESULTS: The response rate was about 50%. Most of the 379 clerkship directors who responded (77%) stated they were aware the HCFA documentation guidelines include specifications regarding the role medical students can play and documentation of medical visits, and 64% indicated they were concerned the guidelines would affect their educational programs. Concerns included the loss of student independence and active participation in the patient care environment (37), time constraints and the changing balance between education and service (16), loss of faculty and decreased morale (11), and decreased quality of care for patients (7). CONCLUSION: Leaders of medical education must work to modify these guidelines to protect the quality of patients' care, while maximizing students' educational opportunity and participation. 相似文献
4.
Tori Smedal Hildegunn Lygren Kjell‐Morten Myhr Rolf Moe‐Nilssen Bente Gjelsvik Olav Gjelsvik Liv Inger Strand 《Physiotherapy research international》2006,11(2):104-116
Background and Purpose . Patients with multiple sclerosis (MS) tend to have movement difficulties, and the effect of physiotherapy for this group of patients has been subjected to limited systematic research. In the present study physiotherapy based on the Bobath concept, applied to MS patients with balance and gait problems, was evaluated. The ability of different functional tests to demonstrate change was evaluated. Method . A single‐subject experimental study design with ABAA phases was used, and two patients with relapsing–remitting MS in stable phase were treated. Tests were performed 12 times, three at each phase: A (at baseline); B (during treatment); A (immediately after treatment); and A (after two months). The key feature of treatment was facilitation of postural activity and selective control of movement. Several performance and self‐report measures and interviews were used. Results . After intervention, improved balance was shown by the Berg Balance Scale (BBS) in both patients, and improved quality of gait was indicated by the Rivermead Visual Gait Assessment (RVGA). The patients also reported improved balance and gait function in the interviews and scored their condition as ‘much improved’. Gait parameters, recorded by an electronic walkway, changed, but differently in the two patients. Among the physical performance tests the BBS and the RVGA demonstrated the highest change, while no or minimal change was demonstrated by the Rivermead Mobility Index (RMI) and Ratings of Perceived Exertion (RPE). Conclusion . The findings indicate that balance and gait can be improved after physiotherapy based on the Bobath concept, but this should be further evaluated in larger controlled trials of patients with MS. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
5.
Alice H.M. Beare PhD ; Stephen M. Krane MD ; Mark W.J. Ferguson DDS PhD 《Wound repair and regeneration》2005,13(1):27-40
Collagen undergoes dramatic reorganization during wound repair. Matrix metalloproteinases degrade and remodel collagen in a tightly controlled process. The collagenase-resistant mouse, Col1a1(tm1Jae), produces type I collagen, which is resistant to degradation by human matrix metalloproteinase 1. These mice grow normally but develop thickened skin with age. We have previously reported that the early wound repair response in homozygous mutant (Col1a1(r/r)) mice is delayed compared to wild type (Col1a1(+/+)). However, the late-stage scar of Col1a1(r/r) wounds was not significantly altered compared to Col1a1(+/+). Here we have investigated the response of heterozygous mice (Col1a1(+/r)) to wounding, not previously reported. Wound reepithelialization was delayed to a similar degree to wounds in the Col1a1(r/r) mice. However, the recovery of impaired wound contraction was faster in Col1a1(+/r) than in Col1a1(r/r) mice, but still slower than in wild-type animals. Analysis of wound protein extracts showed expression of some matrix metalloproteinases was prolonged in both the Col1a1(r/r) and Col1a1(+/r) wounds compared to wild type. We suggest the partial resistance of collagen to collagenase-mediated degradation in the heterozygous animals causes equivalent impairment of keratinocyte migration compared to homozygous collagenase-resistant mice, but that wound contraction during late-stage healing is only partially retarded. 相似文献
6.
Exercise rapidly increases eukaryotic elongation factor 2 phosphorylation in skeletal muscle of men 总被引:11,自引:6,他引:5
Adam J. Rose Christa Broholm Kristian Kiillerich Stephen G. Finn Christopher G. Proud Mark H. Rider Erik A. Richter Bente Kiens 《The Journal of physiology》2005,569(1):223-228
Protein synthesis in skeletal muscle is known to decrease during contractions but the underlying regulatory mechanisms are unknown. Here, the effect of exercise on skeletal muscle eukaryotic elongation factor 2 (eEF2) phosphorylation, a key component in protein translation machinery, was examined. Eight healthy men exercised on a cycle ergometer at a workload eliciting ∼67% peak pulmonary oxygen consumption with skeletal muscle biopsies taken from the vastus lateralis muscle at rest as well as after 1, 10, 30, 60 and 90 min of exercise. In response to exercise, there was a rapid (i.e. < 1 min) 5- to 7-fold increase in eEF2 phosphorylation at Thr56 that was sustained for 90 min of continuous exercise. The in vitro activity of skeletal muscle eEF2 kinase was not altered by exercise indicating that the increased activity of eEF2 kinase to eEF2 is not mediated by covalent mechanisms. In support of this, the increase in AMPK activity was temporally unrelated to eEF2 phosphorylation. However, skeletal muscle eEF2 kinase was potently activated by Ca2 + –calmodulin in vitro , suggesting that the higher eEF2 phosphorylation in working skeletal muscle is mediated by allosteric activation of eEF2 kinase by Ca2 + signalling via calmodulin. Given that eEF2 phosphorylation inhibits eEF2 activity and mRNA translation, these findings suggest that the inhibition of protein synthesis in contracting skeletal muscle is due to the Ca2 + -induced stimulation of eEF2 kinase. 相似文献
7.
Trazodone hydrochloride is an oral antidepressant agent which has been associated with the improvement of erections in impotent men and the development of prolonged erections or priapism in potent men. An in vivo study in animal and human subjects was performed to gain experience with the effect of intracavernosal trazodone. In the anesthetized New Zealand White rabbit, intracavernosal trazodone or its major metabolite m-chlorophenylpiperazine (m-CPP) produced full penile erection in 76% and 84% of animals studied respectively with doses ranging from one to 15 mg. On the other hand, intracavernosal administration of five mg. papaverine resulted in a prolonged erection in 90% of animals studied. In 13 selected volunteer patients, intracavernosal trazodone caused tumescence but not full penile erection with corporal body pressures of 28.2 +/- 5.8 mm. Hg. Intracavernosal papaverine or papaverine and phentolamine in these subjects resulted in significantly higher corporal body pressures of 58 +/- 18 mm. Hg (p less than .05). Intracavernosal administration of alpha adrenoceptor agonists but not normal saline resulted in complete detumescence of trazodone- or m-CPP-induced prolonged erection in the animal studies. Intracavernosal trazodone results in erectile activity that appears in part based on its local alpha blocking activity but like other intracavernosal alpha-blocking agents is not as effective in initiating penile erections as are intracavernosal agents that directly induce smooth muscle relaxation. 相似文献
8.
9.
A.L. Zietman M.D. R.A. Edelstein M.D. J.J. Coen B.S. R.K. Babayan M.D. R.J. Krane M.D. 《Urology》1994,43(6)
Objective. This retrospective study evaluated the outcome for a cohort of men undergoing radical retropubic prostatectomy alone as primary treatment for clinical T1–2 prostate adenocarcinoma.Methods. Sixty-two patients treated at Boston University Medical Center between 1987 and 1992 underwent radical prostatectomy alone without adjuvant or neoadjuvant endocrine therapy. Actuarial and multivariate analyses were made of disease-free outcome according to preoperative tumor T stage, prostate-specific antigen (PSA), and biopsy grade, and according to the pathologic findings at surgery. Recurrence was defined as the persistence or recurrence of detectable serum PSA four or more weeks following surgery.Results. Of all patients judged clinically to have localized disease (T1–2), 52 percent proved to have pathologic T3 tumors. Of these, 81 percent had positive surgical margins. The strongest preoperative predictors of pT3 disease were the biopsy Gleason grade and the initial serum PSA value. Actuarial analysis showed the overall likelihood of remaining free from detectable PSA at four years to be 43 percent (75% for those with organ-confined disease and 27% for those who were pT3). The poorest prognosis was seen in those with seminal vesicle involvement. Biopsy Gleason grade and initial PSA were independent preoperative predictors of biochemical failure in a Cox regression analysis but clinical T stage was not.Conclusions. The biopsy Gleason grade and initial PSA were identified as strong preoperative predictors of disease-free outcome. We confirmed the favorable prognosis of men with organ-confined disease, but emphasize the high likelihood of relapse in those with positive surgical margins or seminal vesicle invasion. 相似文献
10.
Bente E. Moen Bjrg E. Hollund Morten Berntsen Ragnar Flo Knut Rasmus Kyvik Trond Riise 《American journal of industrial medicine》1995,27(4):555-564
Occupational exposure to carcinogenic agents on the decks on six Norwegian crude oil tankers was examined in five harbors. The purpose of the study was to evaluate the need for improving the working environment on deck on these tankers. Technical arrangments and the work itself on the deck were observed during loading or unloading. Occupational monitoring was performed by active sampling of benzene, polyaromatic hydrocarbons, and some aldehydes. The crew answered a questionnaire concerning their work, use of protective equipment, and occurrence of acute symptoms. The levels of air-borne carcinogenic agents were low, probably due to closed loading systems on all tankers. However, the seamen reported discomfort during the work that may be related to other chemical agents in the cargo. The seamen were frequently painting with lead chromate paint without using personal protective equipment. This type of chemical exposure should be evaluated. 相似文献