全文获取类型
收费全文 | 52907篇 |
免费 | 3317篇 |
国内免费 | 157篇 |
专业分类
耳鼻咽喉 | 672篇 |
儿科学 | 1520篇 |
妇产科学 | 925篇 |
基础医学 | 6382篇 |
口腔科学 | 901篇 |
临床医学 | 5334篇 |
内科学 | 11588篇 |
皮肤病学 | 909篇 |
神经病学 | 4888篇 |
特种医学 | 2063篇 |
外国民族医学 | 4篇 |
外科学 | 9025篇 |
综合类 | 532篇 |
一般理论 | 52篇 |
预防医学 | 3379篇 |
眼科学 | 846篇 |
药学 | 3277篇 |
中国医学 | 53篇 |
肿瘤学 | 4031篇 |
出版年
2023年 | 264篇 |
2022年 | 448篇 |
2021年 | 1149篇 |
2020年 | 677篇 |
2019年 | 1154篇 |
2018年 | 1366篇 |
2017年 | 995篇 |
2016年 | 1046篇 |
2015年 | 1247篇 |
2014年 | 1907篇 |
2013年 | 2428篇 |
2012年 | 3899篇 |
2011年 | 4094篇 |
2010年 | 2284篇 |
2009年 | 1957篇 |
2008年 | 3552篇 |
2007年 | 3748篇 |
2006年 | 3720篇 |
2005年 | 3613篇 |
2004年 | 3470篇 |
2003年 | 3233篇 |
2002年 | 2969篇 |
2001年 | 451篇 |
2000年 | 332篇 |
1999年 | 458篇 |
1998年 | 594篇 |
1997年 | 486篇 |
1996年 | 376篇 |
1995年 | 377篇 |
1994年 | 356篇 |
1993年 | 283篇 |
1992年 | 246篇 |
1991年 | 260篇 |
1990年 | 246篇 |
1989年 | 207篇 |
1988年 | 193篇 |
1987年 | 179篇 |
1986年 | 188篇 |
1985年 | 177篇 |
1984年 | 220篇 |
1983年 | 213篇 |
1982年 | 219篇 |
1981年 | 190篇 |
1980年 | 136篇 |
1979年 | 111篇 |
1978年 | 93篇 |
1977年 | 84篇 |
1976年 | 56篇 |
1975年 | 49篇 |
1974年 | 62篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
12.
13.
James I. Geller MD Joseph G. Pressey MD Malcolm A. Smith MD Rachel A. Kudgus PhD Mariana Cajaiba MD Joel M. Reid PhD David Hall PhD Donald A. Barkauskas PhD Stephen D. Voss MD Steve Y. Cho MD Stacey L. Berg MD Jeffrey S. Dome MD PhD Elizabeth Fox MD Brenda J. Weigel MD 《Cancer》2020,126(24):5303-5310
14.
Jeffrey Schatz Robert Buzan 《Journal of the International Neuropsychological Society》2006,12(1):24-33
We assessed midsagittal corpus callosum size in sickle cell disease (SCD) and its relationship to lesion volume, lesion location, and cognitive functioning. Twenty-eight children with SCD and 16 demographic controls completed magnetic resonance imaging (MRI) and neuropsychological testing. Corpus callosum (CC) size was smaller for children with silent infarcts (n = 8) or overt stroke (n = 8) than for those without visible infarcts (n = 12) or control participants. Lesion volume was a robust predictor of IQ and other cognitive scores; total CC size did not typically add explanatory power for these measures. The size of the rostral body of the CC, however, independently predicted measures of distractibility, speeded production, and working memory. Posterior CC size was also decreased among many of the children with SCD, even in the absence of visible infarcts in this region. Brain morphology appears to provide additional information about SCD-related effects on the brain above and beyond visible infarcts. 相似文献
15.
Stability of transverse expansion in the mandibular arch. 总被引:1,自引:0,他引:1
Jeffrey A Housley Ram S Nanda G Fr?ns Currier Dale E McCune 《American journal of orthodontics and dentofacial orthopedics》2003,124(3):288-293
This was a retrospective, longitudinal cephalometric and cast study of 29 white patients at pretreatment, posttreatment, and an average of 6 years 3 months postretention. The goal was to assess changes with treatment and retention with the expanding mandibular lingual arch appliance in conjunction with fixed edgewise treatment. Seven mandibular cast measurements were assessed, including arch crowding, arch perimeter, arch length, and arch width at the permanent canines, first premolars, second premolars, and first molars. Cephalometric radiographs were digitized, and 16 cephalometric measurements were made. Repeated-measures analysis of variance and 2-sample t tests were used to determine statistically significant changes. It was found that the expanding lingual arch used for less than 6 months with the mandibular fixed edgewise appliance caused an increase in both the transverse and sagittal dimensions of the mandibular dental arch. Transverse expansion was more stable in the posterior region of the mandibular dental arch than in the anterior region. Mandibular intercanine width increase could be maintained only by fixed retention. Although the maxillary and mandibular incisors were advanced and proclined, lip protrusion did not occur. 相似文献
16.
Lisa A. Lang DDS MS David C. Holmes DDS MS Craig Passon DDS MS Robert M. Trombly DDS JD Jeffrey D. Astroth DDS MSPH Arnold F. Tavel DMD 《Journal of prosthodontics》2003,12(3):206-210
Using complete denture treatment as an introduction to clinical patient care for dental students, the purposes of the Complete Denture Prosthodontics Transition Clinic at the University of Colorado School of Dentistry are to reduce the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience, and to encourage development of student self-confidence and skills. In the 2002 spring semester, faculty at the University of Colorado School of Dentistry initiated the Complete Denture Prosthodontics Transition Clinic for DS-II (second-year) dental students, as an introduction to clinical patient care. Each patient was assigned to a team of two dental students. Three Division of Prosthodontics faculty members staffed each clinic session, providing a student-to-faculty ratio of approximately 6.6:1 and a patient-to-faculty ratio of approximately 3.3:1. All DS-II students in the Class of 2004 delivered their first complete dentures no later than 8 months (average, 184 days) after the last day of the preclinical complete denture prosthodontics course. The time from the diagnostic appointment through the denture placement appointment averaged 39 days for patients treated in this program, compared with an average of 98 days or more for previous classes. The program was successful in achieving the goal of reducing the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience. 相似文献
17.
Sonographic features of benign thyroid nodules: interobserver reliability and overlap with malignancy. 总被引:4,自引:0,他引:4
Jeffrey R Wienke Wui K Chong Julia R Fielding Kelly H Zou Carol A Mittelstaedt 《Journal of ultrasound in medicine》2003,22(10):1027-1031
OBJECTIVE: To prospectively determine the sonographic findings of nodular hyperplasia of the thyroid, to compare these with reported findings associated with malignancy, and to assess interobserver reliability. METHODS: Seventy thyroid nodules were scanned, and then biopsies of the nodules were performed under sonographic guidance with fine-needle cytologic analysis; in all cases images were reviewed by 2 experienced radiologists without knowledge of clinical outcome. Findings reported associated with malignancy were specifically assessed. Interobserver agreement between the expert and secondary readers for each finding was calculated by the kappa or weighted kappa statistic and the Fisher exact test of independence. RESULTS: There were 68 benign and 2 malignant nodules in a population of 63 female and 7 male patients. The mean benign nodule size was 2.9 cm; 60% were solid; 54% were hypoechoic; 59% were microlobulated or macrolobulated; 47% had central vascularity; 24% contained calcifications; and 82% were elliptical in shape. There was very good interobserver reliability for the presence of calcium (kappa = 0.91) and good agreement for the presence and location of vascularity (kappa = 0.75) and the amount of cystic components (kappa = 0.62; all P < .01). CONCLUSIONS: Sixty-nine percent of benign nodules had at least 1 finding reported previously as associated with malignancy. The interobserver reliability of the sonographic findings was good to very good for 3 of the 5 findings assessed. 相似文献
18.
Mild traumatic brain injury in an insured population: subjective complaints and return to employment 总被引:5,自引:0,他引:5
The great majority of traumatic brain injury (TBI) is of mild severity, with Glasgow Coma Scores (GCS) of 13-15, post-traumatic amnesia of less than 48 hours and brief, if any, hospitalization. All mild TBI admissions to hospital were provided with education in the form of a brief interview and a brochure on minor head trauma from the National Head Injury Foundation. Seventy-seven insured individuals with mild TBI were contacted by phone between 1 and 3 months post-injury to determine the frequency and severity of post-traumatic symptoms and the rate of return to work (RTW). Twenty-six per cent of those contacted had subjective complaints; 88% had returned to work or school; 16% of those returning did so with some symptoms. Only 45% of symptomatic individuals sought medical consultation for their condition when offered. Education about post-traumatic symptoms from the onset may provide sufficient reassurance to most individuals that future use of medical services is seen as unnecessary. Rate of RTW is relatively higher than reported in previous studies of mild TBI. 相似文献
19.
Veena Kumari Jeffrey A. Gray Philip J. Corr Owen F. Mulligan Paul A. Cotter Stuart A. Checkley 《Psychopharmacology》1997,129(3):271-276
The effects of an indirect dopamine-agonist, d-amphetamine, and a non-selective dopamine receptor antagonist, haloperidol, were investigated in normal male volunteers using
a between-subjects double-blind design in a procedural learning task, thought mainly to involve unconscious/automatic learning.
The results showed: (1) d-amphetamine facilitated response speed, whereas haloperidol inhibited it, in comparison to placebo; (2) the linear increase
in procedural learning corresponded with pharmacological manipulation of degree of dopaminergic activity, i.e. subjects given
haloperidol showed the least, and subjects given d-amphetamine the greatest, procedural learning. The implications of these findings are discussed in relation to investigation
of abnormalities of procedural learning processes in schizophrenia.
Received: 28 June 1996/Final version: 2 October 1996 相似文献
20.