首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   414篇
  免费   28篇
  国内免费   14篇
儿科学   16篇
妇产科学   5篇
基础医学   39篇
口腔科学   5篇
临床医学   27篇
内科学   106篇
皮肤病学   1篇
神经病学   23篇
特种医学   58篇
外科学   41篇
综合类   33篇
预防医学   13篇
眼科学   2篇
药学   12篇
中国医学   1篇
肿瘤学   74篇
  2023年   4篇
  2022年   2篇
  2021年   14篇
  2020年   6篇
  2019年   16篇
  2018年   12篇
  2017年   9篇
  2016年   7篇
  2015年   11篇
  2014年   16篇
  2013年   33篇
  2012年   31篇
  2011年   21篇
  2010年   17篇
  2009年   15篇
  2008年   23篇
  2007年   20篇
  2006年   18篇
  2005年   19篇
  2004年   6篇
  2003年   8篇
  2002年   9篇
  2001年   11篇
  2000年   6篇
  1999年   2篇
  1998年   11篇
  1997年   6篇
  1996年   9篇
  1995年   7篇
  1994年   5篇
  1993年   9篇
  1992年   6篇
  1991年   3篇
  1990年   6篇
  1989年   8篇
  1988年   4篇
  1987年   3篇
  1985年   6篇
  1984年   3篇
  1983年   4篇
  1982年   2篇
  1981年   3篇
  1980年   4篇
  1979年   3篇
  1978年   3篇
  1977年   3篇
  1975年   2篇
  1964年   2篇
  1962年   1篇
  1961年   3篇
排序方式: 共有456条查询结果,搜索用时 31 毫秒
31.

Background  

Improved survival due to advances in neonatal care has brought issues such as postnatal growth and development more to the focus of our attention. Most studies report stunting in children born very preterm and/or small for gestational age. In this article we study the growth pattern of these children and aim to identify factors associated with postnatal catch-up growth.  相似文献   
32.
A retrospective study was conducted to determine the incidence of nerve injuries in anterior dislocations of the shoulder and to determine if a neurological examination is routinely performed in such cases. One hundred and fifteen shoulder dislocations in 100 patients (74 males, 26 females; mean age 35+/-18 years) were reviewed. Eighty-seven patients were examined for neurological injuries prior to reduction and 8 of these patients (9.2%) were found to have sustained neurological injuries. Following reduction, neurological examination was performed in 85 patients. Three patients who were not examined initially prior to reduction were subsequently found to have nerve injuries after reduction. Seven patients (7%) were not examined for neurological injury both before and after reduction of the dislocation. Eleven patients were found to have sustained nerve injuries in the final analysis. Axillary nerve injuries were the most common, occurring in 8 patients. In conclusion, nerve injuries are common in shoulder dislocations. The importance of performing and documenting the findings of neurological examination anterior shoulder dislocations needs to be reiterated.  相似文献   
33.
OBJECTIVE: To carry out a comparative study of the safety and immunogenicity of Vi polysaccharide vaccine against whole-cell killed (WCK) typhoid vaccine. METHODS: The study was carried out on young adult recruits (aged 18-25 years) of the Malaysian Air Force. A total of 125 subjects received the Vi polysaccharide vaccine and 114 received the WCK vaccine. FINDINGS: The Vi vaccine was significantly less reactogenic than the WCK vaccine with regard to systemic and local reactions. Following administration of the Vi vaccine, seroconversion rates (defined as the percentage of subjects with a 4-fold rise of baseline antibody level) of 75.5% and 67% were observed at 2 weeks and 6 weeks, respectively, after immunization, compared with 25% and 31.3% among recipients of the WCK vaccine. Of the 110 Vi vaccinees with serological data, 21 (19%) had high, seroprotective, pre-immunization levels of anti-Vi antibodies (> or = 1 microgram/ml). The majority of subjects in this group came from a region in Malaysia which is known to have high typhoid endemicity. Interestingly, these antibody levels were boosted considerably following administration of vaccine at a level that was 5-fold higher than in subjects with low pre-immunization levels. In contrast, the seroconversion rates in those receiving the Vi vaccine were higher in subjects with low pre-immunization levels of anti-Vi antibodies (76-84%), compared to those with protective levels of > or = 1 microgram/ml prior to immunization (48-57%). CONCLUSIONS: The study reaffirms the safety and efficacy of the Vi polysaccharide vaccine and identifies a hitherto unrecognized advantage in its use, i.e. it is a potent immunogen that boosted considerably the protective antibody levels among a significant number of immunologically sensitized individuals living in typhoid-endemic regions.  相似文献   
34.
Currently, there are no established objective biomarkers for the diagnosis or monitoring of schizophrenia. It has been previously reported that there are notable qualitative differences in the speech of schizophrenics. The objective of this study was to determine whether a quantitative acoustic and temporal analysis of speech may be a potential biomarker for schizophrenia.In this study, 39 schizophrenic patients and 18 controls were digitally recorded reading aloud an emotionally neutral text passage from a children's story. Temporal, energy and vocal pitch features were automatically extracted from the recordings. A classifier based on linear discriminant analysis was employed to differentiate between controls and schizophrenic subjects.Processing the recordings with the algorithm developed demonstrated that it is possible to differentiate schizophrenic patients and controls with a classification accuracy of 79.4% (specificity = 83.6%, sensitivity = 75.2%) based on speech pause related parameters extracted from recordings carried out in standard office (non-studio) environments.Acoustic and temporal analysis of speech may represent a potential tool for the objective analysis in schizophrenia.  相似文献   
35.

Purpose  

Neonatal neoplasms are rare tumours notorious for their atypical presentation and unpredictable behaviour. Their optimal treatment remains uncertain, a dilemma compounded by the deleterious effects of adjuvant chemo- or radiotherapy during this vulnerable period of growth. This paper examined the relatively high incidence of these tumours and its impact on paediatric surgery in Malaysia.  相似文献   
36.
37.
Background: Lower testosterone levels are associated with anaemia in older men and women. The relation between testosterone and haemoglobin (Hb) in younger and middle-aged men is less well defined. The aim of the study was to examine the association between testosterone and Hb levels in men spanning middle to older ages.
Methods: A cross-sectional analysis of 492 men aged 30.7–94.5 years from the Busselton Health Survey, Western Australia, was carried out. Haemoglobin (Hb), early-morning serum total testosterone and sex hormone-binding globulin (SHBG) were measured. Free testosterone was calculated using mass action equations.
Results: Haemoglobin correlated to total and free testosterone concentrations ( r = 0.13, P = 0.003 and r = 0.20, P < 0.001, respectively). Hb and SHBG were inversely correlated ( r =−0.14, P = 0.001). Hb increased across lowest to highest quartiles of total testosterone ( P = 0.02) and free testosterone ( P < 0.001), but not SHBG. After adjusting for age, waist circumference, smoking status, alcohol consumption, renal function and ferritin, total testosterone was associated with Hb ( β = 0.037, P = 0.003) as was free testosterone ( β = 2.32, P < 0.001), whereas SHBG was not associated.
Conclusion: Testosterone concentration modulates Hb levels in community-dwelling men across a wide age range. Further studies are needed to clarify implications of this association between testosterone and Hb in men.  相似文献   
38.
One hundred patients with B-cell non-Hodgkin's lymphoma (NHL) in sensitive relapse or incomplete first remission underwent high-dose chemoradiotherapy and anti-B-cell monoclonal antibody (MAb)-treated autologous bone marrow transplantation (ABMT). These patients demonstrated good performance status with a Karnofsky score of 80% or greater. The majority of these patients had one or more adverse prognostic features including a failure to achieve a complete remission (CR) with conventional combination chemotherapy (37 patients), bone marrow infiltration (69 patients), a history of extranodal disease other than bone marrow infiltration (42 patients), and histologic conversion (18 patients). At the time of ABMT, only 52 patients were in CR; however, all patients achieved a minimal disease state following conventional intensive therapy. Moreover, at the time of marrow harvest, 37 of these patients had histologic evidence of lymphoma cells infiltrating the marrow. Following high-dose ablative therapy, two acute in-hospital treatment-related deaths were observed. Two late deaths were observed, not due to recurrent lymphoma. Of the remaining 96 patients, 61 are in unmaintained CR with a median follow-up of 13 months. Kaplan-Meier actuarial analysis predicts 50% probability of disease-free survival (DFS) at 37.8 months. This very low treatment-related mortality provides the rationale to apply high-dose therapy and ABMT as consolidative therapy for patients in first remission who are at high risk for relapse following conventional therapy.  相似文献   
39.
40.
BACKGROUND: Transfusion guidelines recommend that clinicians assess patients for signs and symptoms of anemia before the transfusion of RBCs. However, studies of signs and symptoms associated with acute isovolemic anemia are limited. The objective of this study was to determine whether acute reduction of Hb concentration to 5 g per dL would result in fatigue, tachycardia, or hypotension in resting, young, healthy, isovolemic humans, and whether changes were reversible with RBC transfusion. STUDY DESIGN AND METHODS: Conscious, resting, healthy adults less than 35 years old (n = 8) underwent acute isovolemic hemodilution to Hb of 5 g per dL and self-scored their energy level at various Hb concentrations. Heart rate and blood pressure were also measured. For controls, measurements of each subject were made during a comparable period of rest without hemodilution. RESULTS: During acute isovolemic hemodilution, energy levels decreased progressively and were lower at Hb of 7, 6, and 5 g per dL than at baseline (p<0.01) or in control sessions (p<0.05). The energy level was lower at Hb 7 g per dL than at 14 ( p = 0.005), lower at Hb 6 g per dL than at 7 (p = 0.01), and lower at Hb 5 g per dL than at 6 (p =0.01). Energy levels rose and were not different from baseline or control levels after transfusion of all autologous RBCs. Similarly, median heart rate increased with hemodilution to Hb of 7, 6, and 5 g per dL and decreased with transfusion of autologous RBCs. Supine blood pressure did not decrease with isovolemic hemodilution. CONCLUSION: In resting, young, healthy humans, acute isovolemic anemia to Hb levels of 7, 6, and 5 g per dL results in decreased self-scored energy levels and in an increase in heart rate but not in hypotension. Changes in energy and heart rate are reversible with the transfusion of autologous RBCs.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号