全文获取类型
收费全文 | 3587篇 |
免费 | 264篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 61篇 |
儿科学 | 171篇 |
妇产科学 | 66篇 |
基础医学 | 409篇 |
口腔科学 | 105篇 |
临床医学 | 352篇 |
内科学 | 556篇 |
皮肤病学 | 62篇 |
神经病学 | 558篇 |
特种医学 | 303篇 |
外科学 | 538篇 |
综合类 | 55篇 |
一般理论 | 2篇 |
预防医学 | 219篇 |
眼科学 | 39篇 |
药学 | 176篇 |
1篇 | |
中国医学 | 10篇 |
肿瘤学 | 174篇 |
出版年
2021年 | 60篇 |
2020年 | 37篇 |
2019年 | 55篇 |
2018年 | 55篇 |
2017年 | 59篇 |
2016年 | 58篇 |
2015年 | 68篇 |
2014年 | 97篇 |
2013年 | 101篇 |
2012年 | 144篇 |
2011年 | 155篇 |
2010年 | 114篇 |
2009年 | 98篇 |
2008年 | 131篇 |
2007年 | 129篇 |
2006年 | 153篇 |
2005年 | 130篇 |
2004年 | 124篇 |
2003年 | 113篇 |
2002年 | 98篇 |
2001年 | 109篇 |
2000年 | 108篇 |
1999年 | 85篇 |
1998年 | 71篇 |
1997年 | 64篇 |
1996年 | 68篇 |
1995年 | 75篇 |
1994年 | 66篇 |
1993年 | 62篇 |
1992年 | 71篇 |
1991年 | 59篇 |
1990年 | 70篇 |
1989年 | 83篇 |
1988年 | 73篇 |
1987年 | 90篇 |
1986年 | 70篇 |
1985年 | 64篇 |
1984年 | 55篇 |
1983年 | 42篇 |
1982年 | 37篇 |
1981年 | 34篇 |
1980年 | 31篇 |
1979年 | 36篇 |
1978年 | 39篇 |
1977年 | 31篇 |
1976年 | 27篇 |
1975年 | 28篇 |
1973年 | 16篇 |
1970年 | 16篇 |
1968年 | 16篇 |
排序方式: 共有3857条查询结果,搜索用时 31 毫秒
951.
Andrew J.A. Holland Ori Ron Agostino Pierro David Drake Joseph I. Curry Edward M. Kiely Lewis Spitz 《Journal of pediatric surgery》2009,44(10):1928-1932
Purpose
The aim of the study was to evaluate the surgical outcome of esophageal atresia (EA) without fistula for 24 years at a single tertiary center for pediatric surgery.Methods
The study used a retrospective chart review of infants diagnosed with EA without fistula between 1981 and 2005.Results
Of 33 patients with EA without fistula, 31 charts were available. Mean birth weight was 2327 g (range, 905-3390 g), and 71% were male. Most common associated anomalies were cardiac (n = 6; 19%) and renal (n = 5; 16%), followed by vertebral (n = 4; 13%) and anorectal (n = 2; 7%). The median initial esophageal gap was 5 vertebral bodies. Six had a primary repair, and 25 patients had esophageal replacement at a median age of 7 months. This involved gastric transposition in 20 (1 followed failed jejunal interposition), colonic interposition in 5, jejunal interposition in 1 (after a failed colonic), and repair at another center in 1. With a median review of 9 years, 21 patients had long-term sequelae with the need for multiple further surgical procedures including an antireflux procedure in 5. One patient died.Conclusions
Management of EA without fistula remains challenging. Most patients required staged treatment that included esophageal replacement. The frequency of late complications indicates the need for programmed long-term review. 相似文献952.
Yellow fever vaccine induces integrated multilineage and polyfunctional immune responses 总被引:1,自引:0,他引:1
Denis Gaucher Ren Therrien Nadia Kettaf Bastian R. Angermann Genevive Boucher Abdelali Filali-Mouhim Janice M. Moser Riyaz S. Mehta Donald R. Drake III Erika Castro Rama Akondy Aline Rinfret Bader Yassine-Diab Elias A. Said Younes Chouikh Mark J. Cameron Robert Clum David Kelvin Roland Somogyi Larry D. Greller Robert S. Balderas Peter Wilkinson Giuseppe Pantaleo Jim Tartaglia Elias K. Haddad Rafick-Pierre Skaly 《The Journal of experimental medicine》2008,205(13):3119-3131
953.
BACKGROUND: Controversy exists regarding occurrence and measurement of structural variants of albumin in urine. In this study, we examined cross-reactivity of in vitro modified albumins in assays for urine albumin (microalbumin). METHODS: We analyzed albumin modified by reagents, trypsin, or physical treatments or differing in primary sequence (animal albumins) with an immunoturbidimetric assay (Beckman LX20) using goat antiserum and a competitive immunoassay (Siemens Immulite) using a monoclonal antibody. We assessed occurrence of albumin fragments in urine by use of Western blotting of 24 specimens. RESULTS: Chemical modification, modest sequence substitution (gorilla albumin), or cleavage of albumin by cyanogen bromide (CNBr) had little effect on reactivity in the LX20 assay. Albumin extensively cleaved with trypsin retained partial reactivity. The Immulite assay generally was affected more severely by albumin modifications and sequence changes. Western blots of fresh urine specimens or specimens stored at -80 degrees C showed little albumin fragmentation, but some specimens stored for 3 years at -20 degrees C had extensively fragmented albumin that was detected by the LX20 but not the Immulite assay. CONCLUSIONS: Nearly equivalent reactivity of intact albumin and CNBr fragments in the immunoturbidimetric assay indicates reactivity of antibodies with multiple epitopes throughout albumin. Therefore, it is difficult to abolish reactivity of albumin in this type of urine albumin assay. Differential sensitivity of 2 assays to albumin modification identifies a potential source of assay nonequivalence in measuring urinary albumin, particularly for specimens stored at -20 degrees C. 相似文献
954.
BACKGROUND: The Individual Placement and Support (IPS) model of supported employment for clients with severe mental illness has been described as a standardization of evidence-based supported employment. Although several reviews on the literature on its effectiveness have been conducted, the completion of several new studies suggests an updated review is warranted. METHODS: We conducted a comprehensive literature search for randomized controlled trials of IPS, limiting our review to programs with high-fidelity IPS programs, locating 11 studies. We examined the following competitive employment outcomes: employment rates, days to first job, annualized weeks worked, and job tenure in longest job held during the follow-up period. FINDINGS: Across the 11 studies, the competitive employment rate was 61% for IPS compared to 23% for controls. About two-thirds of those who obtained competitive employment worked 20 hours or more per week. Among those who obtained a competitive job, IPS participants obtained their first job nearly 10 weeks earlier than did controls. Among IPS participants who obtained competitive work, duration of employment after the start of the first job averaged 24.2 weeks per year, or 47% of the 52-week year. CONCLUSIONS: The current review is consistent with earlier reviews, although the evidence for high-fidelity IPS appears to be somewhat stronger here than in reviews evaluating studies with more heterogeneity in the supported employment models examined. The number, consistency, and effect sizes of studies of evidence-based supported employment establish it as one of the most robust interventions available for persons with severe mental illness. 相似文献
955.
Wood DM Button J Ashraf T Walker S Greene SL Drake N Ramsey J Holt DW Dargan PI 《QJM : monthly journal of the Association of Physicians》2008,101(3):207-213
BACKGROUND: There is increasing interest in whether methamphetamine is an emerging recreational drug in the UK. AIM: To determine what evidence is there that methamphetamine use is an emerging drug in the UK compared to established recreational drugs such as MDMA. Design and methods: We undertook a retrospective study collating data on the number of enquiries to both our poisons centre and the UK National Poisons Information Service (NPIS) relating to all recreational drugs, methamphetamine and MDMA; presentations to our Emergency Department (ED) with acute methamphetamine toxicity and the frequency of positive urine tests for methamphetamine and MDMA in workplace drug screening programmes. RESULTS: There was a small increase in the number of methamphetamine-related calls to our poisons centre, but it remained uncommon (0.1% of all recreational drugs cases in 2000 to 1.23% in 2006) compared to MDMA (17.3-42.7% of all recreational drugs cases). The number of 2005/6 enquiries to the UK NPIS for methamphetamine was 12, compared to 455 MDMA enquiries (0.014 and 0.52% of all enquiries, respectively). There were five presentations to our ED relating to methamphetamine over a 15-month period compared to 171 for MDMA. Of the 254 440 urine samples screened for the presence of drugs in the workplace (2000-06), three were positive for methamphetamine and 147 for MDMA. CONCLUSION: There is no evidence of increasing use of methamphetamine or that acute methamphetamine poisoning is a significant clinical problem compared to established recreational drugs such as MDMA. In our opinion, healthcare, educational and law enforcement resources should be proportionally directed towards tackling drugs that pose an immediate and continuing healthcare risk to the population rather than emerging recreational drugs. 相似文献
956.
Ade-Ajayi N Hall NJ Liesner R Kiely EM Pierro A Roebuck DJ Drake DP 《Journal of pediatric surgery》2008,43(10):1827-1832
Purpose
We report our experience of the management of arterial occlusion in the newborn.Methods
A case note review was carried out after ethical approval. Doppler ultrasonography confirmed the occlusion. Thrombolysis was the primary intervention. Surgery was used selectively. A good outcome was one without tissue loss or functional impairment or minimal tissue loss without functional impairment. Data are presented as medians with ranges.Results
Ten patients (9 male; median gestational age, 35.5 weeks [range, 28-39 weeks]) presented on day 1 (range, 1-8 days). Initial management included systemic tissue plasminogen activator (8 patients) and surgery (2 infants in whom thrombolysis was contraindicated). Improvement was noted in 7 of 8 infants treated medically and in both who underwent surgery. Three infants had significant tissue loss. Outcome at 29 months (range, 1.3-95.4 months) was good in the remaining 7.Conclusions
A multidisciplinary approach, thrombolysis and selective surgery achieved tissue preservation and function in the majority while minimizing complications. Early referral to centers with multidisciplinary teams is recommended. 相似文献957.
Newton-Cheh C Guo CY Gona P Larson MG Benjamin EJ Wang TJ Kathiresan S O'Donnell CJ Musone SL Camargo AL Drake JA Levy D Hirschhorn JN Vasan RS 《Hypertension》2007,49(4):846-856
Aldosterone:renin ratio (ARR) is used to screen for hyperaldosteronism. Data regarding correlates of ambulatory ARR in the community and its relation to hypertension incidence are limited. We defined clinical correlates of ARR, determined its heritability, tested for association and linkage, and related ARR to blood pressure (BP) progression in nonhypertensive individuals among 3326 individuals from the Framingham Heart Study (53% women; mean age: 59 years). Ambulatory morning ARR (serum aldosterone and plasma renin concentrations) were related to clinical covariates, genetic variation across the REN locus, a 10-cM linkage map, and among nonhypertensive participants (n=1773) to progression of >or=1 Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure BP category (optimal: <120/80 mm Hg, normal: 120 to 129/80 to 84 mm Hg, high normal: 130 to 139/85 to 89 mm Hg, hypertension: >or=140/90 mm Hg), or incident hypertension (systolic BP: >or=140 mm Hg, diastolic BP: >or=90 mm Hg, or use of antihypertensive treatment). ARR was positively associated with age, female sex, untreated hypertension, total/high-density lipoprotein cholesterol ratio, hormone replacement therapy, and beta-blocker use, but negatively associated with angiotensin-converting enzyme inhibitor and diuretic use. ARR was heritable (h(2)=0.40), had modest linkage to chromosome 11p (logarithm of the odds: 1.89), but was not associated with 17 common variants in REN (n=1729). On follow-up (mean: 3 years), 607 nonhypertensive individuals (34.2%) developed BP progression, and 283 (16.0%) developed hypertension. Higher baseline logARR was associated with increased risk of BP progression (odds ratio per SD increment: 1.23; 95% CI: 1.11 to 1.37) and hypertension incidence (odds ratio per SD increment: 1.16; 95% CI: 1.00 to 1.33). ARR is a heritable trait influenced by clinical and genetic factors. There is a continuous gradient of increasing risk of BP progression across ARR levels in nonhypertensive individuals. 相似文献
958.
Mohamed IS Otsubo H Shroff M Donner E Drake J Snead OC 《Clinical neurology and neurosurgery》2007,109(2):182-187
Gelastic seizures are relatively uncommon and rarely observed secondary to frontal lobe lesions. This report presents magnetoencephalography (MEG) and diffusion tensor imaging (DTI) findings in an adolescent with gelastic seizures secondary to a left anterior cingulate gyrus lesion. Ictal scalp video EEG showed bilateral frontal 4 Hz theta discharges. Interictal EEG showed left fronto-temporal spikes or sharp waves. Interictal MEG showed spike sources over bilateral temporal regions. DTI and tractography delineated slightly shifted corpus callosum posterior to the lesion, unaffected uncinate and inferior longitudinal fasciculi. The patient became seizure free for 12 months after surgical excision of a pleomorphic xanthoastrocytoma in the left anterior cingulate region. In our patient, MEG and EEG did not localize the deep-seated epileptogenic zone. The combination of DTI and neurophysiologic studies, however, possibly disclosed neuronal connections within the epileptic network and indicated that epileptic discharges propagated via the uncinate fibers from the primary epileptogenic zone in the anterior cingulate region to the mesial temporal region in this case with gelastic seizures secondary to a cingulate lesion. 相似文献
959.
960.
OBJECTIVE: Individuals with diabetes and individuals with serious mental illness are more likely than the general population to die prematurely. The study examined the impact of diabetes on mortality among 197 individuals with co-occurring psychotic and substance use disorders who participated in a randomized controlled study of integrated mental health and substance abuse treatment. METHODS: The authors examined Medicaid claims for evidence of diabetes and applied survival analyses to examine whether time from study entry until death was different for individuals with and without evidence of diabetes. RESULTS: Of individuals with co-occurring psychotic and substance use disorders, 21% had evidence of diabetes. In a 12-year period, 41% of those with evidence of diabetes died compared with 10% of those without evidence of diabetes. CONCLUSIONS: Interventions targeted for diabetes prevention and diabetes management are critical for persons with serious mental illness, particularly among those who also abuse substances. 相似文献