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   12691篇
  免费   865篇
  国内免费   147篇
耳鼻咽喉   68篇
儿科学   2篇
妇产科学   43篇
基础医学   526篇
口腔科学   95篇
临床医学   1726篇
内科学   2175篇
皮肤病学   47篇
神经病学   473篇
特种医学   212篇
外科学   1294篇
综合类   2544篇
预防医学   1817篇
眼科学   17篇
药学   1550篇
  21篇
中国医学   340篇
肿瘤学   753篇
  2024年   34篇
  2023年   195篇
  2022年   408篇
  2021年   621篇
  2020年   534篇
  2019年   462篇
  2018年   558篇
  2017年   493篇
  2016年   611篇
  2015年   594篇
  2014年   1462篇
  2013年   1252篇
  2012年   1164篇
  2011年   1105篇
  2010年   785篇
  2009年   567篇
  2008年   483篇
  2007年   408篇
  2006年   318篇
  2005年   302篇
  2004年   233篇
  2003年   182篇
  2002年   157篇
  2001年   136篇
  2000年   120篇
  1999年   81篇
  1998年   77篇
  1997年   52篇
  1996年   45篇
  1995年   37篇
  1994年   44篇
  1993年   41篇
  1992年   25篇
  1991年   27篇
  1990年   25篇
  1989年   11篇
  1988年   13篇
  1987年   12篇
  1986年   7篇
  1985年   8篇
  1984年   5篇
  1983年   2篇
  1982年   2篇
  1981年   2篇
  1980年   1篇
  1979年   1篇
  1977年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
76例老年人蛛网膜下腔出血的临床特点   总被引:1,自引:0,他引:1  
目的 探讨老年人蛛网膜下腔出血的特点。方法 回顾分析1989年1月-1998年8月收治60岁以上原发性蛛网膜下腔出血76例的临床资料。结果 本组老年蛛网膜下腔出血的临床特点为:(1)头痛发生率低且程度较轻,脑膜刺激征不明显;(2)意识障碍,精神症状明显;(3)消化道出血,ECG明显异常及血糖明显升高等并发症多见。结论 如老年人突然出现眩晕、精神异常或突发颈、臂、腰背疼痛等脊神经刺激征状时,应考虑到  相似文献   
92.
Objective: Children with special health care needs are increasingly enrolling in managed care arrangements. However, existing managed care organizations, including traditional HMOs, are often poorly suited for caring for this population. In the adult health care area, new managed care entities, called Social HMOs (S/HMO) and Programs for the All-inclusive Care for the Elderly (PACE), have been created to integrate health and health-related services for chronically ill and disabled adults. We describe these models and assess their potential for serving children with special health care needs. Method: We reviewed the literature on managed care for children with special health care needs and evaluation findings from the S/HMO and PACE models for the elderly. Results: Evaluations of the S/HMO and PACE models have yielded mixed findings. Some of the more positive accomplishments include lower use and expenditures for long-term care services compared to other demonstration projects, greater integration of primary care physicians in decision making concerning long-term care, and improved management of transitions between care levels. On the negative side, start-up has been slow, prospective members have been hesitant to enroll, intermittent and sometimes frequent operating deficits have emerged, no discernible positive effects on health or social outcomes are apparent, and no significant overall savings have emerged. Conclusions: With mixed results so far, caution is required in applying these or similar models for vulnerable child populations. However, given the inadequacies of traditional managed care for this population, we believe experimentation with new models of care that integrate health and health-related services is important. Such experimentation should be fostered only to the extent that the models are carefully designed and then implemented in a manner that protects the interests of children with special health care needs.  相似文献   
93.
Reperfusion therapy by thrombolysis or angioplasty was consideredin 260 unselected patients consecutively admitted within 6 hof the onset of Q wave myocardial infarction. Rates of reperfusionand in-hospital mortality were compared in 206 patients <70years and 54 patients 70 years. Early reperfusion was obtainedin 864% of the patients under 70 years and in 72·2% ofthose over 70 (P<0·01). Thrombolysis was more frequentlyused in the younger group (66·0% vs 31·5%, P<10–5and primary angioplasty in the older (44·4% vs 29·6%,P<0·05). Overall in-hospital mortality was higherin the older group (22·2% vs 4·4 P<10–5After successful reperfusion, mortality was 12·8% inthe patients over 70 and 3·9% in those under 70. Afterfailed or unproven reperfusion, mortality was 46·7% inthe patients over 70 and 7·1% in those under 70. Reperfusiontherapy is feasible in the majority of patients over 70 years,but failure to attempt or to achieve reperfusion is associatedwith a poor outcome. Although not controlled, this study providesan incentive for attempting early reperfusion therapy as oftenas possible in the elderly with acute myocardial infarction.  相似文献   
94.
An evaluation of the utility, morbidity, and patient tolerance of colonoscopy in elderly (70 years) patients was undertaken and compared to data for a similar group of younger patients (50–70 years) who underwent colonoscopy during the same 48 months. Data reviewed for both groups included demographics, indications for colonoscopy, effectiveness of bowel preparation, colonoscopy completion, endoscopic findings, and complications. The mean age of the entire 656-patient population was 69±10 years; 87 (25%) of the 354 elderly patients were greater than 80 years of age and the average age of the 302-member control group was 59.8±5.8 years. Indications for colonoscopy were the same in both groups and included rectal bleeding, 134 (20%); prior colorectal operation, 115 (18%); a history of adenomatous polyps, 82 (12%); guaiac-positive stools, 49 (8%); abnormal finding on barium enema, 19 (3%); and miscellaneous other gastrointestinal symptoms, 151 (23%). Screening colonoscopy was performed in 106 (16%). Colonoscopy was successfully completed to the cecum or the ileocolic anastomosis in 85% (555/656) of the entire population. Only 78% (275/354) of elderly patients had colonoscopy successfully completed compared to 93% (281/302) of their younger counterparts (P=0.001). Elderly patients were significantly more likely to have an abnormality than younger patients (74% vs 60%, P<0.05). Malignant colorectal neoplasia was more common in the elderly (6% vs 2%, P=0.03); however, benign neoplasia was equally present in both age groups (30% vs 27%, P=NS). Thirty percent (195/656) of all patients underwent either snare polypectomy or biopsy. There were no perforations, and postprocedural hemorrhage occurred in 2% (4/195) and was unrelated to age. Overall morbidity, including procedural-related oxygen desaturation, was no different between the two groups. There were no deaths. We conclude that colonoscopy is safe in elderly patients and that advanced age does not, by itself, confer increased risk to the procedure. The lower completion rate in elderly patients mandated additional subsequent testing to complete colonic evaluation but was offset by the significantly increased likelihood of discovering treatable pathology. These results support the continued, aggressive use of colonoscopy in the colonic evaluation of the elderly.  相似文献   
95.
目的 了解中国社区老年人脑认知相关生活方式的分布特征,并探讨其综合评分对早期认知功能下降的影响。方法 研究对象来自老年期重点疾病预防和干预项目。纳入2015年基线调查及2017年随访调查均完成认知功能状况评定,且基线未患痴呆的2 537名≥60岁的社区老年人。通过问卷调查收集其脑认知相关生活方式信息(体育锻炼、社会交往、脑力休闲活动、睡眠质量、吸烟状况与饮酒状况)并计算综合评分。通过多因素logistic回归模型分析脑认知相关生活方式综合评分与早期认知功能下降的关联。结果 2 537名社区老年人群中,评分5~6分者占28.7%,6项脑认知相关生活方式因子均健康者仅占4.8%。男性与女性的健康生活方式因子分布存在差异。多因素logistic回归模型结果显示,与评分0~3分组相比,评分4分和5~6分组早期认知功能下降的风险降低(OR=0.683,95%CI:0.457~1.019;OR=0.623,95%CI:0.398~0.976;趋势P=0.030)。在女性中,与评分0~3分组相比,评分4分和5~6分组的早期认知功能下降的风险降低(OR=0.491,95%CI:0.297~0.812;OR=0.556,95%CI:0.332~0.929;趋势P=0.024)。结论 脑认知相关综合健康生活方式与早期认知功能下降风险降低密切相关,在女性群体中尤为显著。  相似文献   
96.
高校离退休老人躯体健康与心理状况的相关性研究   总被引:10,自引:1,他引:9  
目的:了解离退休老人躯体健康和心理状况的关系。方法:采用CMI和SCL-90对225名高校离退休老人进行调查,分析两者的关系。结果:既往健康状况、神经系统疾病和躯体化成正相关;强迫与呼吸系统疾病成正相关,与心血管系统疾病成负相关;疲劳感和敌对成负相关,和睡眠饮食障碍成负相关。结论:维持老人心身健康,主要在于防治慢性疾病和神经系统疾病,以及对躯体化障碍和强迫症状的干预  相似文献   
97.
In 1996 Congress enacted legislation which, among other things, substantially cut off Supplemental Security Income payments and food stamps for present and future legal alien residents of the United States, and made it much harder for them to qualify for Medicaid. For low-income elderly immigrants, who constituted more than two-thirds of aliens on SSI, the adverse and potential impacts were substantial in terms of economic hardship and access to health care. In the months that followed, their plight received significant attention from the media and state and local politicians who now had greater economic and social responsibilities thrust upon them. One year later, Congress restored SSI benefits only for aliens who been receiving them before August 22, 1996 and made it easier for them to qualify for Medicaid. Food stamp benefits, however, were not restored. The limited scope of this restoration of benefits means that many of today's older immigrants, as well as those in the future, will be faced with serious problems in meeting their basic income and health care needs.  相似文献   
98.
Cancer mortality was analysed in 3282 elderly subjects aged 65 years from 2 cohorts of general population having different life-style patterns. They took part in the CASTEL (CArdiovascular STudy in the ELderly), a 12-year lasting prospective Italian study. The aim of the present analysis was to identify the items able to influence cancer mortality. A biochemical profile and a questionnaire on lifestyle were collected. Continuous items were averaged and compared with analysis of variance, frequencies with the Pearson's 2 test. Mortality was recorded yearly for 12 years from the Registrar's Office and causes of death double-checked by consulting medical case sheets and family doctors' files. The influence of items on mortality was evaluated with the Cox multivariate analysis. Relative risk (RR) of each item was adjusted for confounders. Age, gender, tobacco smoking, the presence of respiratory symptoms, low body mass index in males, serum alanine transaminase (ALT) and alkaline phosphatase (ALP), as well as the town of residence, were powerful predictors of cancer mortality. In the entire population, 12-year overall mortality was 49.4%, cardiovascular 22.8%, and neoplastic 11%; the latter was higher in males than in females (15.7% vs. 7.9%, p < 0.00001). In subjects with respiratory symptoms neoplastic mortality was 11.6% (RR: 1.47) vs. 9.7% in those without symptoms (p < 0.01). Subjects with very low cholesterol ( 178 mg/dl), those with high uric acid ( 8.7 mg/dl) and males with low body mass index ( 22.7 kg/m2) has an increased risk of cancer mortality. RR of cancer mortality increased with increasing ALT or ALP. It was 1 in those having ALT and ALP between 9 and 41.2U/I, 1.41 in those exceeding this latter level and < 1 in those below 9U/I. RR of ALP had a similar trend, the best protective cut-off value being <106 and the worst one > 177U/I. When both serum enzymes were simultaneously raised, RR of cancer mortality increased to 2.84.  相似文献   
99.
We performed this case–control study to evaluate the risk of hypoglycemia associated with the use of antihypertensive drugs in older hospitalized diabetic patients treated with sulfonylureas and/or insulin. All diabetic patients admitted during 4 months in 1988, 1 month in 1991, 4 months in 1993 and 4 months in 1995 (n = 3477, mean age 71.4 ± 0.2 years, 1542 males and 1935 females) were enrolled in the study. During the four annual surveys 86 patients (mean age 71.1 ± 1.4 years, 33 males and 53 females) presented hypoglycemia during hospital stay. The patients who presented hypoglycemia were less frequently users of sulfonylureas and more frequently users of a combination of insulin and sulfonylureas. Use of antihypertensive drugs was similar in the two groups studied, and among potentially interacting drugs considered in the analysis, sulfonamides were more frequently used in patients who experienced hypoglycemia. Moreover, patients with hypoglycemia used a higher number of drugs, had a longer length of stay and had a greater prevalence of hypoglycemia as admission problem. Finally, although not significant, liver and renal diseases were more frequent among patients with hypoglycemia. In the multivariate analysis, contemporary use of insulin and sulfonylureas, liver disease and length of stay were significantly associated with hypoglycemia, while none of the antihypertensive drugs showed a significant association with the occurrence of hypoglycemia during hospital stay. Our results indicate that antihypertensive drugs do not increase the risk of hypoglycemia in elderly diabetic patients.  相似文献   
100.
Clinical experience and previous research show that older people at risk of falling can become anxious at the thought of being on the floor, therefore physiotherapists and occupational therapists may be reluctant to teach them how to get up.Old people's reactions to two different methods of teaching them this skill are compared (three groups, mean age 84 years). The conventional method requires people to be helped down to the floor and then to learn how to get on to their knees prior to getting up with the help of furniture. An alternative method, based on backward-chaining principles, does not require that people start from the floor and reduces the likelihood of them experiencing failure. The activity is broken down into small steps — the last step in the chain being taught first.It is concluded that:
1 The backward-chaining method of teaching elderly people how to get up from the floor is much less stressful to older people and to staff than the conventional method.
2 Older people are slightly more likely to learn successfully how to get up from the floor by the backward-chaining method which, even if they are not successful, provides them with functionally relevant exercise.
3 Older people who cannot learn to get up from the floor should be helped to develop alternative strategies for summoning help and for preventing the consequences of the long lie.
Key Words: Elderly people; falls; long lie  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