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   336篇
  免费   28篇
  国内免费   4篇
儿科学   25篇
妇产科学   1篇
基础医学   23篇
口腔科学   8篇
临床医学   57篇
内科学   63篇
皮肤病学   8篇
神经病学   8篇
特种医学   78篇
外科学   28篇
综合类   6篇
预防医学   32篇
眼科学   3篇
药学   11篇
  2篇
肿瘤学   15篇
  2023年   4篇
  2020年   3篇
  2019年   4篇
  2018年   8篇
  2017年   5篇
  2016年   6篇
  2015年   8篇
  2014年   11篇
  2013年   17篇
  2012年   11篇
  2011年   4篇
  2010年   14篇
  2009年   19篇
  2008年   8篇
  2007年   5篇
  2006年   8篇
  2005年   4篇
  2004年   7篇
  2003年   4篇
  2002年   7篇
  2001年   6篇
  2000年   3篇
  1999年   8篇
  1998年   18篇
  1997年   19篇
  1996年   16篇
  1995年   16篇
  1994年   15篇
  1993年   10篇
  1992年   3篇
  1991年   6篇
  1990年   7篇
  1989年   11篇
  1988年   4篇
  1987年   7篇
  1986年   7篇
  1985年   8篇
  1984年   3篇
  1983年   8篇
  1982年   3篇
  1981年   1篇
  1980年   4篇
  1979年   6篇
  1978年   5篇
  1977年   4篇
  1976年   7篇
  1975年   4篇
  1958年   2篇
排序方式: 共有368条查询结果,搜索用时 15 毫秒
1.
Clinical aspects of pelvic inflammatory disease   总被引:2,自引:0,他引:2  
Pelvic inflammatory disease (PID) is a common and poorly managed condition. Untreated or inadequately treated, it leads to tubal infertility, ectopic pregnancy and chronic pelvic pain. Diagnostic difficulties are compounded by the wide variety of clinical presentations and the insensitivity and poor specificity of laboratory tests. Better recognition of mild and atypical disease needs a high index of suspicion whenever young, sexually active women present with gynaecological symptoms. Laparoscopy supplemented by microbiological tests and fimbrial minibiopsy should be regarded as the diagnostic 'gold standard' for research studies; new studies are required to identify techniques which might reduce under- and over-diagnosis. Early treatment reduces the risk of an adverse effect on fertility. Any therapeutic regimen selected should be effective against the common aetiological agents Chlamydia trachomatis, Neisseria gonorrhoeae, genital mycoplasmas and aerobic and anaerobic bacteria. Since at least 60% of cases of PID can be attributed to infection with a sexually transmitted organism, partner notification forms an essential part of management.   相似文献   
2.
Screening for early ovarian cancer   总被引:5,自引:0,他引:5  
Taylor  KJ; Schwartz  PE 《Radiology》1994,192(1):1
  相似文献   
3.
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major health problem with an estimated prevalence of 10-15% among smokers. The incidence of moderate COPD, as defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD), is largely unknown. AIM: To determine the cumulative incidence of moderate COPD (forced expiratory volume in 1 second/forced vital capacity ratio [FEV1/FVC] <0.7 and FEV1 <80% predicted) and its association with patient characteristics in a cohort of male smokers. DESIGN: Prospective cohort study. SETTING: The city of IJsselstein, a small town in the Netherlands. METHOD: Smokers aged 40-65 years who were registered with local GPs, participated in a study to identify undetected COPD. Baseline measurements were taken in 1998 of 399 smokers with normal spirometry (n = 292) or mild COPD (FEV1/FVC <0.7 and FEV1 >or=80% predicted, n = 107) and follow-up measurements were conducted in 2003. RESULTS: After a mean follow-up of 5.2 years, 33 participants developed moderate COPD (GOLD II). This showed an estimated cumulative incidence of 8.3% (95% CI = 5.8 to 11.4) and a mean annual incidence of 1.6%. No participant developed severe airflow obstruction. The risk of developing moderate COPD in smokers with baseline mild COPD (GOLD I) was five times higher than in those with baseline normal spirometry (one in five versus one in 25). CONCLUSIONS: In a cohort of middle-aged male smokers, the estimated cumulative incidence of moderate COPD (GOLD II) over 5 years was relatively high (8.3%). Age, childhood smoking, cough, and one or more GP contacts for lower respiratory tract problems were independently associated with incident moderate COPD.  相似文献   
4.
BACKGROUND: Chest radiography (CXR) is frequently performed in Western societies. There is insufficient knowledge of its diagnostic value in terms of changes in patient management decisions in primary care. AIM: To assess the influence of CXR on patient management in general practice. DESIGN OF STUDY: Prospective cohort study. SETTING: Seventy-eight GPs and three general hospitals in the Netherlands. METHOD: Patients (n = 792) aged > or =18 years referred by their GPs for CXR were included. The main outcome was change in patient management assessed by means of questionnaires filled in by GPs before and after CXR. RESULTS: Mean age of the patients was 57.3+/-16.2 years and 53% were male. Clinically relevant abnormalities were found in 24% of the CXRs. Patient management changed in 60% of the patients following CXR. Main changes included: fewer referrals to a medical specialist (from 26 to 12%); reduction in initiation or change in therapy (from 24 to 15%); and more frequent reassurance (from 25 to 46%). However, this reassurance was not perceived as such in a quarter of these patients. A change in patient management occurred significantly more frequently in patients with complaints of cough (67%), those who exhibited abnormalities during physical examination (69%), or those with a suspected diagnosis of pneumonia (68%). CONCLUSION: Patient management by the GP changed in 60% of patients following CXR. CXR substantially reduced the number of referrals and initiation or change in therapy, and more patients were reassured by their GP. Thus, CXR is an important diagnostic tool for GPs and seems a cost-effective diagnostic test.  相似文献   
5.
6.
Hegedus  V; Poulsen  PE; Reichardt  J 《Radiology》1978,126(1):29-34
A study of 11 patients with "double pylorus" revealed that a second channel between the gastric antrum and the duodenal bulb is the result of ulcer penetration. The fistula can be a sign of spontaneous recovery from ulcerative disease; the fistula occurred in conjunction with clinical improvement in the majority of the patients. The advantages of radiological vs. endoscopic diagnostic procedures are discussed.  相似文献   
7.
Cross sectional studies have reported impaired growth in children with atopic dermatitis. If this growth impairment is irreversible, it would be expected to adversely influence final height attainment. The standing heights and other anthropometric parameters were assessed in 35 adults with onset of atopic dermatitis before 5 years of age and a control group of 35 adults with adult onset contact dermatitis or psoriasis. There was no significant difference in the standing height SD score, mid-parental height SD score, sitting height SD score, subischial leg length SD score, nor body mass index between the atopic dermatitis and control groups. The standing height SD score was not significantly different among: (a) patients with atopic dermatitis affecting less than 50% of their body surface area and those with greater than 50% affected; (b) patients using the four different potency topical corticosteroids; and (c) patients with atopic dermatitis without asthma and those with coexisting asthma. It is concluded that short stature is not a feature of our group of adult patients with onset of atopic dermatitis before 5 years of age, continuing into adulthood, and severe enough to require specialist care. This suggests that if growth impairment occurs in childhood, it is likely to be temporary and reversible.  相似文献   
8.
The purpose of this article is to outline the criticality of water supply in sustained operations of healthcare facilities, particularly during community emergencies, and to advocate for enhanced cross‐sector support from the water utilities in meeting this need. Information and ideas presented here were developed in the course of a regional project sponsored by the Metropolitan Washington Council of Governments (MWCOG) for development of emergency water supply operations plans for critical water uses in the Washington, DC, area.  相似文献   
9.
Southeast Asian ovalocytosis (SAO) is an asymptomatic trait characterized by rigid, poorly deformable red cells that resist invasion by several strains of malaria parasites. The underlying molecular genetic defect involves simple heterozygous state for a mutant band 3 protein, which contains a deletion of amino acids 400 through 408, linked with a Lys 56-to-Glu substitution (band 3-Memphis polymorphism). To elucidate the contribution of the mutant SAO band 3 protein to increased SAO red blood cell (RBC) rigidity, we examined the participation of the mutant SAO band 3 protein in increased band 3 attachment to the skeleton and band 3 oligomerization. We found first that SAO RBC skeletons retained more band 3 than normal cells and that this increased retention preferentially involved the mutant SAO band 3 protein. Second, SAO RBCs contained a higher percentage of band 3 oligomer-ankyrin complexes than normal cells, and these oligomers were preferentially enriched by the mutant SAO protein. At the ultrastructural level, the increased oligomer formation of SAO RBCs was reflected by stacking of band 3-containing intramembrane particles (IMP) into longitudinal strands. The IMP stacking was not reversed by treating SAO RBCs in alkaline pH (pH 11), which is known to weaken ankyrin-band 3 interactions, or by removing the cytoplasmic domain of band 3 from SAO membranes with trypsin. Finally, we found that band 3 protein in intact SAO RBCs exhibited a markedly decreased rotational mobility, presumably reflecting the increased oligomerization and the membrane skeletal association of the SAO band 3 protein. We propose that the mutant SAO band 3 has an increased propensity to form oligomers, which appear as longitudinal strands of IMP and exhibit increased association with membrane skeleton. This band 3 oligomerization underlies the increase in membrane rigidity by precluding membrane skeletal extension, which is necessary for membrane deformation.  相似文献   
10.
Using a new technique for antigen localization, we have demonstrated platelet proteins in megakaryocytes in plastic-embedded biopsy specimens of normal human bone marrow. In a series of 25 specimens, megakaryocytes showed labeling with antibodies to the integral membrane glycoproteins IIIa, IIb, and the IIb-IIIa complex; granule membrane protein 140; and five alpha-granule matrix proteins: thrombospondin, factor VIII-related antigen, beta-thromboglobulin, platelet factor 4, and fibrinogen. The antibodies to the membrane glycoproteins IIIa, IIb, and IIb-IIIa produced diffuse cytoplasmic staining and heavier staining on the plasma membrane, whereas the antibodies to the alpha-granule matrix proteins produced a distinct granular staining within the cytoplasm. Staining for granule membrane protein 140 was also granular in distribution. Rare mononuclear cells consistent with megakaryocyte precursors were labeled with these markers. Other enzyme histochemical and lectin-binding studies showed that the enzyme alpha-naphthyl acetate esterase, the lectin Ulex europaeus I, and the periodic-acid Schiff reaction were consistent, but not specific, markers of megakaryocytes. This immunohistochemical technique should facilitate the examination of qualitative and quantitative changes in megakaryocytes in a variety of physiologic and pathologic processes.  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