全文获取类型
收费全文 | 1520篇 |
免费 | 84篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 57篇 |
儿科学 | 36篇 |
妇产科学 | 26篇 |
基础医学 | 208篇 |
口腔科学 | 127篇 |
临床医学 | 112篇 |
内科学 | 295篇 |
皮肤病学 | 26篇 |
神经病学 | 128篇 |
特种医学 | 100篇 |
外科学 | 173篇 |
综合类 | 44篇 |
预防医学 | 100篇 |
眼科学 | 26篇 |
药学 | 98篇 |
中国医学 | 1篇 |
肿瘤学 | 60篇 |
出版年
2021年 | 21篇 |
2020年 | 15篇 |
2019年 | 11篇 |
2018年 | 32篇 |
2017年 | 16篇 |
2016年 | 24篇 |
2015年 | 27篇 |
2014年 | 38篇 |
2013年 | 73篇 |
2012年 | 76篇 |
2011年 | 55篇 |
2010年 | 46篇 |
2009年 | 55篇 |
2008年 | 67篇 |
2007年 | 74篇 |
2006年 | 59篇 |
2005年 | 83篇 |
2004年 | 51篇 |
2003年 | 33篇 |
2002年 | 41篇 |
2001年 | 49篇 |
2000年 | 52篇 |
1999年 | 25篇 |
1998年 | 30篇 |
1997年 | 26篇 |
1996年 | 28篇 |
1995年 | 21篇 |
1994年 | 20篇 |
1993年 | 20篇 |
1992年 | 39篇 |
1991年 | 34篇 |
1990年 | 24篇 |
1989年 | 37篇 |
1988年 | 31篇 |
1987年 | 24篇 |
1986年 | 20篇 |
1985年 | 16篇 |
1984年 | 11篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1979年 | 11篇 |
1978年 | 17篇 |
1977年 | 14篇 |
1976年 | 7篇 |
1973年 | 8篇 |
1969年 | 8篇 |
1968年 | 7篇 |
1967年 | 9篇 |
1966年 | 10篇 |
1965年 | 9篇 |
排序方式: 共有1617条查询结果,搜索用时 31 毫秒
1.
Abstract: Background: Identification of risk drinking in expectant fathers may be helpful as an important part of efforts to minimize maternal alcohol use, and as an opportunity to inform them about a problematic practice during a critical developmental stage for the couple. The purpose of this study was to evaluate the T‐ACE screening questionnaire, which asks about t olerance to alcohol, being a nnoyed by other's comments about drinking, attempts to c ut down, and having a drink first thing in the morning (“ e ye‐opener”), in the male partners of pregnant women who themselves were T‐ACE positive. Methods: Two hundred fifty‐four male partners were asked to complete the T‐ACE embedded in a health survey, the Alcohol Use Disorders Identification Test (AUDIT), and other questions about their alcohol use in the past 30 days when their pregnant partners had a median gestation of 11.5 weeks (T1). After delivery, male partners again completed the T‐ACE and quantity‐frequency questions (T2). The predictive ability of the T‐ACE and AUDIT was compared, using risk drinking (>4 drinks/day or >14 drinks/week) as the criterion standard. Results: A substantial minority of male partners had risk drinking, 31 percent at T1 and 25 percent at T2. Although the AUDIT was better than the T‐ACE as an independent predictor of risk drinking, the latter was most accurate when the tolerance threshold exceeded 2 drinks, the same established for pregnant women. The sensitivity (T1 = 84.6%, T2 = 82.8%) and specificity (T1 = 43.8%, T2 = 51.1%) of the T‐ACE at this threshold compared favorably with those of the AUDIT at the standard cut point of 8. Conclusions: The T‐ACE may be a practical way for clinicians to identify risk drinking in both pregnant women and expectant fathers. (BIRTH 33:2 June 2006) 相似文献
2.
Sabrina Hundt Ulrike Haug Hermann Brenner 《Cancer epidemiology, biomarkers & prevention》2007,16(10):1935-1953
BACKGROUND: Despite different available methods for colorectal cancer (CRC) screening and their proven benefits, morbidity, and mortality of this malignancy are still high, partly due to low compliance with screening. Minimally invasive tests based on the analysis of blood specimens may overcome this problem. The purpose of this review was to give an overview of published studies on blood markers aimed at the early detection of CRC and to summarize their performance characteristics. METHOD: The PUBMED database was searched for relevant studies published until June 2006. Only studies with more than 20 cases and more than 20 controls were included. Information on the markers under study, on the underlying study populations, and on performance characteristics was extracted. Special attention was given to performance characteristics by tumor stage. RESULTS: Overall, 93 studies evaluating 70 different markers were included. Most studies were done on protein markers, but DNA markers and RNA markers were also investigated. Performance characteristics varied widely between different markers, but also between different studies using the same marker. Promising results were reported for some novel assays, e.g., assays based on SELDI-TOF MS or MALDI-TOF MS, for some proteins (e.g., soluble CD26 and bone sialoprotein) and also for some genetic assays (e.g., L6 mRNA), but evidence thus far is restricted to single studies with limited sample size and without further external validation. CONCLUSIONS: Larger prospective studies using study populations representing a screening population are needed to verify promising results. In addition, future studies should pay increased attention to the potential of detecting precursor lesions. 相似文献
3.
神经生长因子对小鼠突触体内Ca^2+水平的调节作用 总被引:4,自引:1,他引:3
观察了多次海马内微注射NGF对小鼠突触体内游离钙水平的影响,并在离体情况下观察NGF对EGTA和CaCl2分别造成突触体内低钙和高钙状态的调节作用。结果如下:(1)在体实验表明,一定剂量的NGF可显著降低老年小鼠海马突触体内游离钙水平(P<005);(2)离体实验表明,当突触体游离钙水平降低时,适当剂量的NGF具有升高游离钙水平的作用;而突触体内游离钙水平升高时,则NGF有降低游离钙水平的作用。提示NGF对游离钙水平的双向调节作用可能是NGF改善老年性记忆衰退的作用机制。 相似文献
4.
S. Haug C. Schnopp J. Ring R. F?lster-Holst D. Abeck 《Der Hautarzt; Zeitschrift für Dermatologie, Venerologie, und verwandte Gebiete》2002,174(3):683-685
Es wird über 4 Kleinkinder berichtet, bei denen ein Gianotti-Crosti-Syndrom (GCS) mit einer Latenz von 6–8 Tagen nach Impfung
auftrat. Nachfolgende Auffrischungsimpfungen wurden problemlos vertragen. W?hrend das Auftreten eines GCS in Assoziation mit
einer Virusinfektion gut dokumentiert ist, liegen über das Auftreten eines GCS im Anschluss an eine Impfung nur wenige Mitteilungen
vor. Auf einen derartig m?glichen Zusammenhang sollte jedoch bei Vorstellung dieses Krankheitsbildes (GCS) im Rahmen der Anamneseerhebung
unbedingt eingegangen werden. 相似文献
5.
6.
7.
E S Haug P Romundstad S Aune T B J Hayes H O Myhre 《European journal of vascular and endovascular surgery》2005,29(5):489-495
OBJECTIVES: To study early mortality and long-term survival of patients more than 80 years of age having elective open repair for abdominal aortic aneurysm (AAA). DESIGN: Retrospective multicenter cohort study. MATERIAL: One hundred and five patients, 23 women and 82 men, with a median age of 82 years, operated at three Norwegian hospitals during the period 1983-2002. METHOD: Survival analyses were based on data from medical records and the Norwegian Registrar's Office of Births and Deaths. Expected survival was based on mortality rates of the general population, matched by age, sex, and calendar period. Relative survival was calculated as the ratio between the observed and the expected survival. RESULTS: During the study period there has been a 10 fold increase in octogenarians treated with open operation for AAA. Early mortality (30-day) for the whole group of patients was 10.5% (95% confidence interval (95% CI) 5.3-18.0), and similar for both genders. The 5-year survival rate was 47% (95% CI 35.9-57.4), and not significantly different from that of a matched group in the general population. Patients aged 84 years or more had a median survival time of 35 months (95% CI 18.5-51.6). CONCLUSION: The number of AAA operations in octogenarians has increased considerably during 20 years. Octogenarians operated electively for AAA has higher 30-day mortality as compared to younger patients. Their long-term survival appears similar to a matched control group. The benefit of surgery must be carefully considered against the perioperative risk, especially for the oldest octogenarians. 相似文献
8.
The aim of the study was to evaluate whether complication rate, costs, operation times, and hospitalization times differed in two different patient groups: in group 1, frozen section analysis of the sentinel lymph node and lymph node dissection were carried out in the same operation. In group 2, normal investigation of the sentinel lymph node and lymph node dissection were done in a second operation. One hundred thirty-five patients with cutaneous melanoma were included. Hospitalization times, costs, complication rates, and operation times of two-stage and one-stage lymph node dissection of the draining area after detection of metastases in the sentinel lymph node were retrospectively compared. Lymph node metastasis in the sentinel lymph node was found in 23 patients. In 11 patients, removal of the sentinel lymph node and dissection of the lymph node basin was performed in the same operation. In 12 patients, a two-stage procedure was the treatment of choice. Operation times were not different in the two groups (p=0.87) while two-stage operation patients were hospitalized significantly longer (14.2 ± 9.7 vs 23.9 ± 24 days; p=0.01) and costs were significantly higher (7,836.90 ± 2,397.95 Swiss francs vs 5,279.40 ± 1,994.90 Swiss francs). In addition, more complications were found in the two-stage group. 相似文献
9.
Clinical trial registration: a statement from the International Committee of Medical Journal Editors
下载免费PDF全文
![点击此处可从《Canadian Medical Association journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
10.
MY Mancao LJ Sindel PH Richardson FM Silver 《Acta paediatrica (Oslo, Norway : 1992)》1996,85(1):118-120
Croup is an acute infectious illness usually occurring in children; it is characterized by brassy cough and stridor. The main pathogens include mainly parainfluenza and influenza viruses. Recently there have been reports of prolonged croup caused by the herpes simplex viruses. We report two cases of prolonged croup due to herpes simplex types 1 and 2. We also review and summarize the reported pediatric cases of herpetic croup. 相似文献