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   482篇
  免费   48篇
  国内免费   11篇
耳鼻咽喉   7篇
儿科学   8篇
妇产科学   9篇
基础医学   56篇
口腔科学   7篇
临床医学   83篇
内科学   83篇
皮肤病学   17篇
神经病学   26篇
特种医学   68篇
外科学   41篇
综合类   6篇
现状与发展   1篇
一般理论   2篇
预防医学   44篇
眼科学   5篇
药学   33篇
中国医学   1篇
肿瘤学   44篇
  2023年   22篇
  2022年   6篇
  2021年   13篇
  2020年   15篇
  2019年   8篇
  2018年   16篇
  2017年   19篇
  2016年   21篇
  2015年   15篇
  2014年   20篇
  2013年   21篇
  2012年   17篇
  2011年   9篇
  2010年   17篇
  2009年   18篇
  2008年   16篇
  2007年   22篇
  2006年   8篇
  2005年   7篇
  2004年   9篇
  2003年   6篇
  2002年   11篇
  2001年   6篇
  2000年   6篇
  1999年   6篇
  1998年   13篇
  1997年   9篇
  1996年   3篇
  1995年   9篇
  1994年   15篇
  1993年   10篇
  1992年   12篇
  1991年   16篇
  1990年   8篇
  1989年   10篇
  1988年   10篇
  1987年   14篇
  1986年   7篇
  1985年   7篇
  1984年   8篇
  1983年   8篇
  1982年   5篇
  1981年   6篇
  1980年   7篇
  1979年   4篇
  1978年   6篇
  1977年   3篇
  1976年   5篇
  1975年   2篇
  1974年   3篇
排序方式: 共有541条查询结果,搜索用时 15 毫秒
41.
Data are reported from a larger study of perceptions of locus of control and value of pressure ulcer prevention to show the position of orthopaedic nurse control beliefs, their departmental knowledge level, and their value of pressure ulcer prevention relative to that of staff in other specialties. The survey population consisted of trained and assistant nursing staff in both hospital and community settings of a rural Health Service Trust. Overall results showed that key personnel, such as sisters, were significantly associated with prevalence, in that the more they believed they controlled pressure sore prevention, rather than the patient, the higher the prevalence. This has been explained using locus of control typology. The more it was thought that fate controls pressure sore prevention, the lower the departmental prevalence. Further, beliefs about specific conditions (e.g. pressure ulcer prevention) may be less important than generalized beliefs about control in terms of reducing prevalence.It is suggested that the study is replicated and refined, and that the value of pressure sore prevention needs raising. Certain types of attitudes amongst staff may be unhelpful in a broader range of conditions and outcomes. There may be a need to change control expectations of groups of personnel in order to protect patients.  相似文献   
42.
Malignant melanoma (MM) is a highly aggressive neoplasm with a growing worldwide incidence. It is not uncommon that the disease is already metastatic at the time of the first diagnosis. Regional lymph nodes and skin are the first and most common metastatic sites, followed by distant visceral sites (lungs, liver, and central nervous system) and bone. In this clinical setting, fine-needle aspiration (FNA) often represents the first diagnostic approach. FNA is a useful tool to obtain a rapid and accurate diagnosis, in conjunction with ancillary techniques and molecular analysis, as recommended by recent guidelines. The aim of this review was to describe the cytomorphology, immunocytochemical tools, and molecular tools used for the diagnosis of MM metastases on FNA.  相似文献   
43.
44.
Injection therapy for allergy has been controversial, and its value uncertain. A review of the recent medical literature on injection therapy as it pertains to asthma seems to indicate that this is a valuable treatment when used properly.  相似文献   
45.
目的:实验于2006-02/07在锦州医学院科学实验中心完成。将72只健康SD大鼠按随机数字表法分为假手术组、模型组、神经生长因子治疗组,每组24只。采用Logna等改良法复制大脑中动脉血栓模型,动物清醒2h后进行功能评价,动物神经功能达到2级的纳入实验。假手术组除不进行大脑中动脉线栓外,其余同模型组。神经生长因子治疗组于缺血后立即腹腔注射神经生长因子1000μg/kg,1次/d。于缺血后1,3,7,14d处死动物,运用免疫组化和免疫荧光双标的方法观察神经生长因子对脑缺血后神经干细胞巢蛋白的表达及其细胞类型的影响。结果:72只大鼠均进入结果分析。①神经生长因子治疗组和模型组大脑皮质均可见巢蛋白阳性细胞,细胞呈圆形或椭圆形。与模型组相比,除缺血后1d外,神经生长因子治疗组其他时间点的巢蛋白阳性细胞数均明显高于模型组,两组缺血后各时间点的巢蛋白阳性细胞数均高于假手术组[模型组:(3.47±0.51),(5.13±1.14),(13.95±3.56),(8.97±2.08)个;神经生长因子治疗组:(3.81±0.66),(9.88±2.08),(19.87±3.86),(26.17±2.90)个,假手术组:0,P<0.05,P<0.01]。②模型组和神经生长因子治疗组3d时缺血皮质巢蛋白阳性突起主要与胶质纤维酸性蛋白共存,14d时巢蛋白与神经元特异性烯醇化酶共存明显增多。结论:神经生长因子能增加局灶性脑缺血后巢蛋白的阳性细胞的数目,并促进其分化为神经元和神经胶质细胞。  相似文献   
46.
目的:分析辽西地区城市汉族儿童青少年的体型发育规律和特点,为体质人类学补充必要的数据。方法:按整群分层抽样法,抽取2001-07/2003-09辽西地区城市7所中小学7~19岁经学校正常体质检查证明身体健康的汉族学生,按性别分两大组,每大组按年龄分12小组,7~18岁每岁为1个年龄组,18~19岁为1个年龄组,每小组45~86名,共分24组,搜集完整资料1263名(男657名,女606名)。采用Heath-Carter体型法,每项指标测量2次,取平均值,10项指标由专人负责,测试数据按年龄和性别在微机中建立数据库,依次计算出各年龄组的内因子、中因子和外因子,体型图上的X,Y坐标值,身高/体质量1/3,样本中平均体型点到所有体型点空间距离的均数,三维空间中两个体型点间的差异,体脂含量和各类体型分布频数。结果:参加调查1263名,均进入结果分析。①7~17岁儿童青少年身高、体质量随年龄的增加而增长。平均身高、体质量男生大于女生。身高/体质量1/3指数除14,16和17岁外,各年龄组女生>男生,平均值女生>男生。体脂含量11岁以前男生>女生,12岁以后女生>男生。②辽西地区城市汉族男生的平均体型值为3.9-3.5-3.4,属中间型,女生平均体型值为4.3-2.9-3.6,属偏外胚层的内胚层体型。体型频数的变化提示辽西城市汉族男生体型分布较散,女生分布较集中,主要在内胚层体型。③内因子男生在3.18~4.81,女生在3.05~5.33,11岁以前男生>女生,12岁以后女生>男生;中因子男生在3.02~4.23,女生在2.54~3.42,除16岁男女相差不多外,其他年龄组男生>女生,外因子男生在2.64~4.22,女生在2.92~4.14,13岁以前女生>男生,14岁以后男生>女生。因此,男生较女生骨骼粗壮,肌肉发达,随着年龄的增长,女生的皮下脂肪更发达,体态丰满,男生的身体相对瘦高程度增长,身材修长。男女各年龄组间体型比较,7~,8~,9~,10~,11~,12~,13~,14~,15~,16~,17~,18~19岁三维空间中两个体型点间的差异值分别为0.95,0.85,1.10,1.06,1.37,0.43,0.87,1.44,1.42,1.12,1.11,1.33,7~,8~,12~,14~,17~,18~19年龄组男女间体型差异有显著性(t=2.07,4.09,3.12,3.86,3.39,3.99,P<0.05)。④与国内汉族及其他少数民族相比,辽西汉族男生体脂最多,骨骼肌肉不发达,身体相对矮小;辽西地区汉族女生体脂较多,骨骼肌肉不发达,体型修长。结论:辽西地区城市男生较女生骨骼粗壮,肌肉发达,随着年龄的增长,女生的皮下脂肪更发达,体态丰满,男生的身体相对瘦高程度增长,身材修长。与国内汉族及其他少数民族相比,辽西地区城市汉族儿童青少年体脂发育较好,骨骼肌肉欠发达,青春期是形成健壮体型的关键时期,辽西地区城市儿童青少年应注意合理饮食和加强体育锻炼。  相似文献   
47.
Whetten R  Whetten K  Pence BW  Reif S  Conover C  Bouis S 《AIDS care》2006,18(Z1):S27-S34
Long travel times have been identified as a significant barrier to accessing mental health and other critical services. This study examines whether distance to treatment was a barrier to receiving outpatient mental health and substance abuse care for HIV-positive persons when transportation was provided. Data from a cohort of HIV-positive persons who participated in a year-long substance abuse and mental health treatment programme were examined longitudinally. Transportation, which included buses, taxis, and mileage reimbursement for private transportation, was provided free of charge for participants who needed this assistance. Nearly three-quarters (74%) of participants utilized the transportation services. No statistically significant differences in retention in, or utilization of, the mental health and substance abuse treatment programme were identified by distance to the treatment site. This analysis demonstrated that increased distance to care did not decrease utilization of the treatment programme when transportation was provided to the client when necessary. These results provide preliminary evidence that distance to substance abuse and mental health services need not be a barrier to care for HIV-positive individuals when transportation is provided. Such options may need to be considered when trying to treat geographically dispersed individuals so that efficiencies in treatment can be attained.  相似文献   
48.
Advances in the treatment of HIV and associated opportunistic infections (OIs) have led to dramatic reductions in HIV-related morbidity and mortality in the United States, but not all patients have benefited equally. A longitudinal analysis of the Coping with HIV/AIDS in the Southeast (CHASE) cohort evaluated sociodemographic, psychosocial, and clinical factors associated with HIV-related events (incident category C OI or AIDS-related death) among southern HIV-infected patients engaged in clinical care. Participants were followed for a median of 30 months (interquartile range, 17-34 months) after study enrollment (enrollment period December 2001 to April 2002). Ten percent of study participants (50/489) experienced an HIV-related event (incident category C OI and/or AIDS-related deaths) during study follow-up. The rate of HIV-related events was 4.8 per 100 patient-years of observation, and the rate of AIDS-related death was 1.5 per 100 patient-years of observation. In unadjusted survival analyses, younger age, lacking private health insurance, psychosocial trauma, depressive symptoms, lower baseline CD4 count, and less time on antiretroviral therapy during follow-up were associated with HIV-related events. In Cox proportional hazards analysis adjusting for covariates, patients who had suffered more psychosocial trauma (hazard ratio [HR] = 1.97, p = 0.04), who had lower baseline CD4 counts (HR = 0.48 per 100 cells/mm(3), p < 0.01), and who spent less time on antiretroviral therapy during follow-up (HR = 0.47, p = 0.02) were more likely to experience an HIV-related event.  相似文献   
49.
BACKGROUND: Since screening for antibody to hepatitis C virus (HCV) was introduced in 1990, posttransfusion hepatitis has been reduced to nearly background levels. This has led to reconsideration of the value of testing donated blood for elevated alanine aminotransferase (ALT). The contribution of ALT testing in detecting seronegative infection was evaluated by the performance of polymerase chain reaction (PCR) for hepatitis B virus (HBV) or HCV in plasma from ALT-elevated blood units. STUDY DESIGN AND METHODS: Testing was performed on 375 units of plasma, derived from an equivalent of 47,500 blood donations, with a highly sensitive hemi-nested PCR procedure. Using a triplet of primers directed at the conserved regions of HBV DNA and 5'-noncoding regions of HCV RNA, the hemi-nested PCR assay can reliably amplify 10 viral molecules to levels detectable in ethidium bromide-stained agarose gels. Pools of plasma from groups of four donors were screened with hemi-nested PCR. For any reactive pools, the plasma from individual donors was retested twice on different aliquots. RESULTS: Two of 375 units, both with midrange ALT elevation, were repeatedly reactive in hemi-nested PCR (one each for HBV DNA and HCV RNA). However, samples from the two suspect donors tested 9 and 5 months later revealed no seroconversion, elevated ALT, or viral genomes in hemi-nested PCR. CONCLUSION: The lack of confirmed HBV or HCV infection in this study representing an estimated 47,500 voluntary blood donations suggests that routine ALT testing for further prevention of posttransfusion hepatitis after exclusion of HBV- and/or HCV-seropositive blood may be superfluous.  相似文献   
50.
Coxsackieviral myocarditis is associated with systemic involvement in neonates; however, fulminant coxsackieviral myocarditis is rare in adults, and its dissemination with fatal myocarditis involving kidneys, liver, and adrenal is further rarely reported. We report a case of fulminant myocarditis along with dissemination of coxsackievirus, which was clinically unrecognized.  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