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   151576篇
  免费   13778篇
  国内免费   2818篇
耳鼻咽喉   1025篇
儿科学   2428篇
妇产科学   2026篇
基础医学   5234篇
口腔科学   2854篇
临床医学   49537篇
内科学   14430篇
皮肤病学   1266篇
神经病学   4872篇
特种医学   2893篇
外国民族医学   14篇
外科学   10797篇
综合类   19758篇
现状与发展   2篇
一般理论   7篇
预防医学   23734篇
眼科学   1208篇
药学   12078篇
  620篇
中国医学   8529篇
肿瘤学   4860篇
  2024年   829篇
  2023年   3813篇
  2022年   5797篇
  2021年   7778篇
  2020年   8486篇
  2019年   6582篇
  2018年   5978篇
  2017年   6476篇
  2016年   6705篇
  2015年   6314篇
  2014年   12309篇
  2013年   11716篇
  2012年   10464篇
  2011年   10711篇
  2010年   8495篇
  2009年   8005篇
  2008年   7396篇
  2007年   7278篇
  2006年   6175篇
  2005年   5198篇
  2004年   4078篇
  2003年   3211篇
  2002年   2439篇
  2001年   2156篇
  2000年   1664篇
  1999年   1413篇
  1998年   1126篇
  1997年   932篇
  1996年   756篇
  1995年   627篇
  1994年   536篇
  1993年   430篇
  1992年   430篇
  1991年   304篇
  1990年   246篇
  1989年   197篇
  1988年   155篇
  1987年   144篇
  1986年   113篇
  1985年   133篇
  1984年   128篇
  1983年   73篇
  1982年   73篇
  1981年   70篇
  1980年   64篇
  1979年   34篇
  1978年   45篇
  1977年   28篇
  1976年   20篇
  1975年   15篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
BACKGROUND: End-stage renal disease patients have a poor quality of life (QoL), suffer from impaired cognitive functioning, and their electroencephalogram (EEG) shows abnormalities. Conventional haemodialysis (CHD) only partially restores these disorders. Short daily haemodialysis (SDHD) has been reported to improve QoL, but effects on cognitive functioning and EEG have yet to be described. METHODS: Of the 13 patients (11 male, 2 female, age 45.5 +/- 8.1 years), 11 completed the Kidney Disease Quality of Life and Affect Balance Scale questionnaires, 10 underwent neuropsychological testing, and all 13 underwent EEG examination. For the neuropsychological assessments, nine patients (six male, three female, age 45.4 +/- 12.6) who remained on the CHD schedule, served as controls. The dialysis schedule of thrice-a-week for 4 h was changed in the experimental group to six times a week for 2 h (SDHD) over a period of 6 months and back to thrice a week for 4 h. RESULTS: When on SDHD, patients rated several dimensions of health-related QoL as being improved. After resuming CHD, one of these dimensions again decreased and several others worsened even lower than baseline. Cognitive functioning did not change when compared with control data. On the EEG, alpha peak frequency increased slightly when on SDHD but decreased significantly after resuming CHD. CONCLUSIONS: SDHD improves health-related QoL, but has no clear effects on cognitive functioning and EEG. Resumption of CHD after SDHD decreases aspects of QoL and EEG alpha peak frequency but has no effect on cognitive functioning.  相似文献   
82.
Systemic lupus erythematosus (SLE) is the archetypical immunologic disease. Approximately 20% of patients present in the first two decades of life. This article highlights some of the differences between pediatric and adult onset lupus.Children are defined as different from adults on the basis of age. Lupus presents with different gender ratios based on hormonal or pubertal status with more significant skewing toward female patients in the childbearing years. Female patients in the childbearing years appear to have a higher relative risk for mortality. Despite this, children have greater disease severity at onset based on the number of patients who present with significant organ inflammation, the amount of corticosteroids required and the abnormalities in lupus serologies including autoantibodies and low complements. Children present frequently with congenital and acquired complement defects. Children have an increased risk of infections that can be confused with lupus. They have a higher risk of serious pneumococcal infection and may have less protection from vaccinations received at the time of disease onset.The clinical immunology laboratory is critical in the diagnosis and treatment of pediatric SLE. The rapid analysis and transfer of laboratory results can be life saving for the child with suspected new onset lupus. The laboratory is also helpful in determining disease activity through analysis of immunologic trends over time in pediatric lupus patients. This is especially important in the noncompliant adolescent patient who has a correlation between disease activity and lupus serologic tests. Finally, the clinical immunology laboratory is an important tool for better understanding of the immunologic phenomena associated with lupus and of disease pathophysiology.  相似文献   
83.
BACKGROUND: The reasons for mis-reporting food consumption warrant investigation. OBJECTIVE: To document intention to mis-report food consumption and its associations with psychological measures in women. DESIGN: A total of 184 female volunteers aged 18-65 years, comprising 50 seeking help in primary care to lose weight with a body mass index (BMI) >/=30 kg m(-2) (obese-clinical group) and 134 nurses (nonclinical groups) (BMI <25 kg m(-2), n = 52; BMI 25-29.9 kg m(-2), n = 45; BMI >/=30 kg m(-2), n = 37) were studied. A questionnaire was administered containing three psychological tests (self-esteem, psychological well-being and Stunkard's three-factor eating questionnaire) and new items to address food intake mis-reporting. RESULTS: Overall, 68% of participants declared an inclination to mis-report (64% nonclinical, 78% clinical). Inclination to under-report was 29, 33 and 51% in the three nonclinical groups; and 46% among the obese clinical patients. Among the same groups, inclination to over-report were 39, 29, 11 and 32%. After adjusting for social deprivation and BMI, women inclined to mis-report had higher hunger (P = 0.008) and disinhibition (P = 0.005) scores than those intending to report accurately. These variables were associated with current dieting, frequency of dieting, self-reported bingeing and dissatisfaction with body weight. CONCLUSIONS: These findings indicate that intentional under-reporting and over-reporting of food consumption are common in women of all BMI categories and are associated with eating behaviour. Current dieting, frequency of dieting in the past, self-reported bingeing and dissatisfaction with body weight seem to mediate this relationship.  相似文献   
84.
The Student Training, Education and Practice for Dietetics (STEP‐DIET) CD‐ROM was developed at the University of Surrey to prepare dietetic students for the practical dietetic training component of their Nutrition/Dietetics degree. This study aimed to evaluate student response to the programme and its effectiveness as a teaching tool, based on the evaluation framework of D.L. Kirkpatrick (Evaluating a Course, 2nd edn. London, Kogan Page). Quantitative and qualitative methodologies were employed, with 41 dietetic students, separated by year group, completing questionnaires and taking part in six focus groups, at the University of Surrey. Student attitudes towards the instruction method and the STEP‐DIET programme itself were investigated, in conjunction with their perceived learning achievements. Students rated the programme highly in terms of design and content, however, there was a reluctance to accept computer‐assisted instruction (CAI) as a sole teaching method. A number of learning achievements relevant to dietetic practice were reported including a perceived increase in ability to conduct a dietetic interview and an increased understanding of the management of Type 2 diabetes. In general students reacted positively to the STEP‐DIET programme and it was perceived by students to be effective in preparing them for the practical component of their dietetic training.  相似文献   
85.
临床科室工作量评价方法及其应用   总被引:5,自引:1,他引:4  
目的:探讨测量、评价临床科室工作量的指标和方法,加强医院科室管理,促进效益评价与核算。方法:应用医院病案和报表资料,每月计算科室工作强度指数并进行排位,用相对比方法初步分析科室临床工作量和排位变动的状况。结果:选取了实际占用床位数、危重病人抢救次数、门急诊人次数、出会诊人次数、出院病人数5项指标,计算出各科室工作强度指数和排位,并对各科室工作量排位变动进行了比较。结论:临床工作量评价指标和方法的代表性、灵敏性和可靠性较好,实际评价效果也较客观地反映了各临床科室的实际工作量大小。  相似文献   
86.
目的 观察2-乙氧基乙醇(2-Ethoxythanol,EE)急性染毒对SD大鼠血清和睾丸某些抗氧化指标的变化,探讨EE致睾丸损伤的可能机制。方法 选择健康雄性SD大鼠,体重180-220g。随机分为对照组、EE800、1600和3200mg/kg组4组,每组24只。采取一次性灌胃染毒。于灌胃后12、24、48和72h,将各组动物随机处死6只,留取动物血液、睾丸,制备血清和睾丸匀浆,测定血清和睾丸匀浆脂质过氧化物(LPO)水平、超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性,以及血清铜蓝蛋白(CP)活性。结果 与对照组比较,各染毒组睾/体比明显下降(P<0.05),睾丸匀浆LPO水平和血清CP活性增高。染毒12、24h,血清CAT、睾丸匀浆CAT和SOD活性增高,而染毒48、72h后,血清CAT、睾丸匀浆CAT和SOD活性显著降低(P<0.05)。EE各染毒组血清LPO水平和SOD活性变化不明显。结论 推测EE毒作用的靶器官可能是睾丸,睾丸抗氧化功能的改变是EE致睾丸毒性的可能机制。  相似文献   
87.
88.
网络模式下临床医师绩效评价指标体系研究   总被引:2,自引:0,他引:2  
为了充分利用医院信息网络信息,更为全面、客观地对医生进行评价,阐述建立网络模式下临床医师绩效评价指标体系的原则、方法,并对的建立指标体系的可信度及合理性进行了分析。  相似文献   
89.
BACKGROUND: Our objective was to determine the cost-effectiveness of a comprehensive, risk-based triage system, composed of multiple critical pathways, with the use of early myocardial perfusion imaging (MPI) in low-risk patients. We found previously that a chest pain evaluation system that uses MPI in low-risk patients was safe and effective, but the cost-effectiveness of this approach was not studied. METHODS AND RESULTS: We compared two groups. The Acute Cardiac Team (ACT) group (n = 874) was assigned prospectively to 1 of 4 risk levels by emergency department (ED) physicians. Level 1, 2, and 3 patients were admitted; level 4 patients were evaluated in the ED. Level 3 and 4 patients underwent ED MPI. The control group (n = 713) represented consecutive patients evaluated in the prior year according to standard care and assigned retrospectively to an ACT level based on the presenting electrocardiographic and clinical data. Record and hospital administrative data were assessed for clinical variables, outcomes, lengths of stay, and all expenses incurred within 30 days of the index visit. The baseline characteristics of the two groups were similar, including age, sex, myocardial infarction prevalence, and 30-day revascularization rates within each level or between the two groups. Mean costs per encounter were reduced for the ACT patients for each level, which was significant when all patients were compared ($5,030 +/- $7,081 vs $6,044 +/- $10,432, P =.02). Use of MPI in the low-risk patients was associated with reduced costs (level 3, $4,958 +/- $4,948 vs $5,051 +/- $7,036; level 4, $1,529 +/- $2,664 vs $1,794 +/- $6,854) and was associated with a significantly lower angiography rate and shorter length of stay. CONCLUSIONS: Implementation of a comprehensive strategy for chest pain evaluation and triage reduced overall costs for patients with chest pain on presentation. Acute MPI in the ED setting did not increase net cost.  相似文献   
90.
Objective: The scientific quality of research is an important ethical issue. To clarify the quality of research projects in pharmacotherapy/pharmacology, 40 randomly selected research projects in pharmacotherapy/pharmacology submitted to a research ethics committee were reviewed. Results: Eight of the projects would not have contributed new knowledge nor were they necessary as controls for the results of previous research. Fifteen of the research protocols were of good quality, 15 could be used after revisions, and 10 were unfit for use. Eleven of the research projects were not finished 5 years after they were started. A written report was produced from 26 of the projects. Nine were of good quality and could be accepted for publication in a medical journal, 10 of the reports were in need of revision before publication, and 7 should not be accepted for publication. Conclusion: Research in this field ought to be improved, and ways to improve the standard of clinical trials in pharmacotherapy are dicussed. Received: 1 April 1996 / Accepted in revised form: 28 June 1996  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