全文获取类型
收费全文 | 1829篇 |
免费 | 194篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 101篇 |
妇产科学 | 19篇 |
基础医学 | 163篇 |
口腔科学 | 2篇 |
临床医学 | 145篇 |
内科学 | 404篇 |
皮肤病学 | 34篇 |
神经病学 | 166篇 |
特种医学 | 27篇 |
外科学 | 354篇 |
综合类 | 40篇 |
一般理论 | 2篇 |
预防医学 | 165篇 |
眼科学 | 7篇 |
药学 | 267篇 |
中国医学 | 1篇 |
肿瘤学 | 109篇 |
出版年
2021年 | 13篇 |
2019年 | 29篇 |
2018年 | 28篇 |
2017年 | 21篇 |
2016年 | 29篇 |
2015年 | 20篇 |
2014年 | 44篇 |
2013年 | 50篇 |
2012年 | 81篇 |
2011年 | 69篇 |
2010年 | 46篇 |
2009年 | 33篇 |
2008年 | 82篇 |
2007年 | 82篇 |
2006年 | 79篇 |
2005年 | 97篇 |
2004年 | 90篇 |
2003年 | 84篇 |
2002年 | 56篇 |
2001年 | 64篇 |
2000年 | 60篇 |
1999年 | 43篇 |
1998年 | 26篇 |
1997年 | 14篇 |
1996年 | 14篇 |
1995年 | 15篇 |
1993年 | 12篇 |
1992年 | 47篇 |
1991年 | 54篇 |
1990年 | 53篇 |
1989年 | 41篇 |
1988年 | 36篇 |
1987年 | 41篇 |
1986年 | 27篇 |
1985年 | 31篇 |
1984年 | 29篇 |
1983年 | 25篇 |
1982年 | 14篇 |
1980年 | 18篇 |
1979年 | 20篇 |
1978年 | 18篇 |
1977年 | 15篇 |
1976年 | 19篇 |
1975年 | 15篇 |
1974年 | 36篇 |
1973年 | 15篇 |
1970年 | 12篇 |
1969年 | 21篇 |
1968年 | 21篇 |
1967年 | 16篇 |
排序方式: 共有2027条查询结果,搜索用时 15 毫秒
81.
Children of alcoholic mothers. Growth and motor performance compared to matched controls 总被引:1,自引:0,他引:1
M Kyllerman M Aronson K G Sabel E Karlberg B Sandin R Oleg?rd 《Acta paediatrica Scandinavica》1985,74(1):20-26
Twenty-one children born 1970-76, selected from 103 children of 30 alcoholic women, were paired to controls matched for sex, age, birth weight and gestational age. The sample (10 girls, 11 boys) was representative of the whole group with regard to weight, length and head circumference at birth. At follow-up (mean age 70 months) the study group was significantly leaner, shorter and had smaller mean head circumference than the control group. The controls had significant catch-up growth from birth to follow-up of weight, height and head circumference to the mean for Swedish children. The study group had no catch-up growth. Compared to controls the study group had significantly lower fine and gross motor age test scores and inferior coordination. One child had cerebral palsy (spastic hemiplegia) and in 6 other children slight tremor and ataxia were observed. Malformations and/or other signs of the fetal alcohol syndrome (FAS) were found in 10 cases. Study group children with FAS had significantly slower growth of head circumference than others without FAS. Children placed in foster home care (n = 11) were found to have significantly (p less than 0.05) lower birth weight, birth length and head circumference than children raised at home (n = 10). There were no significant differences at follow up between study group children raised in foster homes or in homes of their biological mother. 相似文献
82.
83.
84.
85.
Freedland SJ Wieder JA Jack GS Dorey F deKernion JB Aronson WJ 《The Journal of urology》2002,168(1):110-115
PURPOSE: Previous studies have suggested that prostate specific antigen (PSA) density is a significant independent predictor of biochemical failure after primary therapy. We determined whether pathological PSA density using surgical weight of the radical prostatectomy specimen was an independent predictor of adverse pathological features or biochemical recurrence after radical prostatectomy. We also examined whether combining pathological PSA density with biopsy Gleason score improved risk stratification compared with serum PSA and biopsy Gleason score for predicting PSA recurrence after prostatectomy. MATERIALS AND METHODS: Multivariate analysis was used to determine whether pathological PSA density was an independent predictor of adverse pathology or PSA recurrence after radical prostatectomy in 325 patients treated at a Veterans Affairs medical center. Cutoff points of pathological PSA density were generated to identify patients at various risks for biochemical recurrence. These cutoffs were combined with biopsy Gleason cutoff points 2 to 6, 7 and 8 to 10 to generate a risk stratification system that was compared with a previous risk stratification system using PSA and biopsy Gleason score cutoff points. The validity of the risk stratification system using pathological PSA density and biopsy Gleason score was evaluated in another cohort of 490 patients treated with radical prostatectomy at a tertiary care medical center. RESULTS: Pathological PSA density was an independent predictor of positive surgical margins (p <0.001), nonorgan confined disease (p <0.001), seminal vesicle invasion (p = 0.003) and biochemical recurrence after radical prostatectomy (p <0.001). The cutoff points for pathological PSA density of less than 0.3, 0.3 to 0.7 and greater than 0.7 ng./ml./gm. separated patients into 3 distinct groups at increasing risk for biochemical failure after radical prostatectomy (p <0.001). Pathological PSA density cutoffs combined with biopsy Gleason score cutoffs 2 to 6, 7 and 8 to 10 provided better risk stratification for biochemical failure than cutoffs based on a combination of PSA and biopsy Gleason score in patients treated at the Veterans Affairs (hazards ratio 3.04, confidence interval 2.25 to 4.11, p <0.001) and tertiary care (hazards ratio 2.38, confidence interval 1.78 to 3.18, p <0.001) medical centers. CONCLUSIONS: Pathological PSA density was a strong predictor of advanced pathology and biochemical failure after radical prostatectomy. Pathological PSA density combined with biopsy Gleason score defined a novel risk group system that improved risk stratification compared with a combination of PSA and biopsy Gleason score. These results were validated in another cohort of patients treated with radical prostatectomy at a tertiary care medical center. Further studies are required using PSA density values calculated from preoperative transrectal ultrasound measurements to determine whether a combination of PSA density and biopsy Gleason score provides significant pretreatment risk stratification. 相似文献
86.
Lefevre F Piper M Weiss K Mark D Clark N Aronson N 《The Journal of family practice》2002,51(10):842-848
OBJECTIVE: Current guidelines recommend use of written action plans and peak flow monitoring as key components of asthma care. Our study assesses whether written action plans, with or without peak flow monitoring, have an independent effect on outcomes when used as a component of asthma self-management. STUDY DESIGN: This was a systematic review of published studies. Two independent reviewers followed a prospective protocol for study selection and data abstraction. Outcome data were synthesized qualitatively; they were not appropriate for quantitative meta-analysis. Our comprehensive literature search used MEDLINE, EMBASE, the Cochrane Library, and a hand search of recent bibliographies. The search was limited to full-length, peer-reviewed articles with abstracts in English. The studies were randomized controlled trials that compared the outcomes of an asthma self-management intervention with and without the use a written action plan. The primary outcomes of interest are utilization measures, such as hospitalizations and ER visits. Other outcomes of interest include measures of symptom control and lung function. POPULATION: There were 1501 evaluable patients with asthma; 1410 adults and 91 children. OUTCOMES MEASURED: We measured the frequency of waiting and examination room companions, the reasons for accompaniment, the influence on the encounter, and the overall helpfulness of the companion as assessed by patients and companions. We also determined the physicianamprsquos assessment of the companionamprsquos influence, helpfulness, and behavior during the encounter. RESULTS: Nine randomized controlled trials enrolling a total of 1501 patients met selection criteria. The majority of comparisons in these studies do not demonstrate improved outcomes associated with a written action plan. There are notable methodologic limitations: studies reporting negative findings lack sufficient power, and studies reporting positive findings demonstrate systematic bias. CONCLUSIONS: Although written action plans are widely used, there is insufficient evidence to determine whether their use, with or without peak flow monitoring, improves outcomes. 相似文献
87.
Clinical use of a rapid collagen binding assay for von Willebrand factor cleaving protease in patients with thrombotic thrombocytopenic purpura 总被引:10,自引:0,他引:10
Rick ME Moll S Taylor MA Krizek DM White GC Aronson DL 《Thrombosis and haemostasis》2002,88(4):598-604
A simple collagen binding assay (CBA) for measuring activity of the von Willebrand factor cleaving protease in clinical samples is described, and results of fifty masked plasmapheresis samples rom patients with TTP/HUS and other diseases are presented. There was 97.5% concordance between the CBA and a multimer gel assay. The CBA identified low protease activity in 78% of patients who had a clinical syndrome consistent with TTP/HUS and in 2 of 10 sick controls, giving it a positive predictive value of 0.94. The heterogeneity regarding the presence or absence of vWF protease activity in patients with TTP/HUS was confirmed by finding a low negative predictive value of 0.50 with the CBA. The CBA detected inhibitors of the protease in 26 of 29 patients (90%) with TTP/HUS and low protease activity levels. The CBA is a useful clinical assay for examining von Willebrand factor protease activity and detecting inhibitors against the protease. 相似文献
88.
Schnater JM Aronson DC Plaschkes J Perilongo G Brown J Otte JB Brugieres L Czauderna P MacKinlay G Vos A 《Cancer》2002,94(4):1111-1120
BACKGROUND: Surgical resection is the cornerstone of treatment for patients with hepatoblastoma (HB). The Society of Pediatric Oncology Liver Tumor Study Group launched its first prospective trial (SIOPEL-1) with the intention to treat all patients with preoperative chemotherapy and delayed surgical resection. The objective of this article was to assess the assumed surgical advantages of primary chemotherapy. METHODS: Between 1990 and 1994, 154 patients age < 16 years with HB were registered on SIOPEL-1. The pretreatment extent of disease was assessed, and, after undergoing biopsy, patients were treated with cisplatin 80 mg/m(2) intravenously over 24 hours and doxorubicin 60 mg/m(2) intravenously over 48 hours by continuous infusion (PLADO). Generally, tumors were resected after four of a total of six courses of PLADO. RESULTS: One hundred twenty eight patients underwent surgical resection (13 patients underwent primary surgery, and 115 patients underwent delayed surgery after PLADO). A pretreatment surgical biopsy was performed in 96 of 128 patients (75%). Biopsy complications occurred in 7 of 96 patients (7%). Twenty-two patients showed pulmonary metastases at the time of diagnosis, and 7 patients underwent thoracotomy. Operative morbidity and mortality were 18% and 5%, respectively. Complete macroscopic surgical resection was achieved in 106 patients (92%), including 6 patients who underwent orthotopic liver transplantation. The actuarial 5-year event free survival (EFS) rate for all 154 patients in the study was 66%, and the overall survival (OS) rate was 75%. For the 115 patients who were included in the surgical analysis that followed the exact protocol, the EFS and OS rates were 75% and 85%, respectively. CONCLUSIONS: Biopsy is a safe procedure and should be performed routinely. Preoperative chemotherapy seems to make tumor resection easier. Reresection of a positive resection margin does not necessarily have to be performed, because postoperative chemotherapy showed good results. Resection of lung metastases can be curative if there is local control of the primary tumor; however, results showed that the patient's prognosis was worse. Surgical morbidity or mortality rates were not necessarily higher in large multicenter studies. More importantly, countries of lesser economic status also can contribute effectively to these trials. 相似文献
89.
Radiofrequency ablation of unresectable primary liver cancer 总被引:7,自引:0,他引:7
90.