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   1855篇
  免费   111篇
耳鼻咽喉   31篇
儿科学   48篇
妇产科学   41篇
基础医学   202篇
口腔科学   130篇
临床医学   157篇
内科学   245篇
皮肤病学   40篇
神经病学   143篇
特种医学   228篇
外科学   142篇
综合类   33篇
一般理论   3篇
预防医学   162篇
眼科学   37篇
药学   163篇
中国医学   5篇
肿瘤学   156篇
  2022年   17篇
  2021年   20篇
  2020年   16篇
  2019年   21篇
  2018年   31篇
  2017年   48篇
  2016年   105篇
  2015年   38篇
  2014年   28篇
  2013年   58篇
  2012年   69篇
  2011年   71篇
  2010年   31篇
  2009年   35篇
  2008年   52篇
  2007年   57篇
  2006年   50篇
  2005年   76篇
  2004年   73篇
  2003年   87篇
  2002年   82篇
  2001年   61篇
  2000年   67篇
  1999年   59篇
  1998年   23篇
  1996年   12篇
  1995年   17篇
  1993年   13篇
  1992年   41篇
  1991年   35篇
  1990年   32篇
  1989年   34篇
  1988年   17篇
  1987年   41篇
  1986年   37篇
  1985年   21篇
  1984年   29篇
  1983年   17篇
  1982年   18篇
  1981年   12篇
  1979年   22篇
  1977年   15篇
  1975年   20篇
  1974年   28篇
  1973年   12篇
  1972年   13篇
  1971年   20篇
  1970年   22篇
  1969年   12篇
  1968年   17篇
排序方式: 共有1966条查询结果,搜索用时 31 毫秒
21.
The allele-specific PCR approach has been modified by introducing a second mismatch at the 3'-penultimate link of the primer and used to identify the sickle cell anemia mutation (A-->T transversion in the sixth codon of the human beta-globin gene causing Glu-->Val substitution in the protein), thus obviating the problem of an interpretationally ambiguous 3'-terminal mismatch including T residue.  相似文献   
22.
Creating a death register for general practice.   总被引:1,自引:2,他引:1       下载免费PDF全文
General practitioners complete approximately 26% of death certificates themselves but have considerable difficulty obtaining prompt and accurate information about their other patients who die. A random survey of district health authorities in England revealed that all were able to compile death lists but none included general practitioner details. This paper reviews the flow of information on patient deaths and describes a project to assess the feasibility of providing Newcastle general practitioners with comprehensive death registers. With the collaboration of the family health services authority and the district health authority, and with data from the regional perinatal mortality survey the creation each week of complete lists of patient deaths, broken down by general practitioner, is feasible. Death registers allow general practitioners to undertake audit of the quality of death certification and of the care of the recently deceased, and to improve the continuing care of the bereaved.  相似文献   
23.
Sixty Vietnam veterans from a midwestern VA Medical Center were surveyed to determine the relationship between symptoms of Post-Traumatic Stress Disorder (PTSD) and five psychosocial variables: Intensity of combat experienced in Vietnam, current subjective impact of the previously experienced stress of Vietnam experiences, current level of life stress, extent and nature of social support available to the veteran during the first year of return from Vietnam, and pre-service psychosocial functioning. A stepwise discriminant function analysis revealed that combat intensity, current impact of the previously experienced events in Vietnam, and current level of life stress correctly classified 75% of the total cases. These findings were supported by other lines of analyses, including tests of correlation and stepwise regression analysis. Current levels of life stress, especially disruption in interpersonal relationships, also were associated significantly with PTSD symptoms. These findings are consistent with previous reports on the etiology and correlates of PTSD symptoms and suggest the existence of a quantifiable constellation of symptoms associated with psychological sequelae of severely stressful trauma.  相似文献   
24.
Summary Na pump current was measured in rat ventricular myocytes to determine if -adrenergic stimulation can directly modulate Na,K-ATPase activity. Enzymatically-isolated heart cells were voltage-clamped with a single patch electrode and Na pump current was briefly activated by rapidly increasing extracellular [K+] from 0 to 15 mM for 3–5 s after other ionic currents were blocked or inactivated. The salt solution in the voltage-clamping electrode included (in mM): (1) 100 Na+, 10 EGTA, (2) 5 Na+, 10 EGTA, or (3) 100 Na+, 7.5 Ca2+, 10 EGTA (free [Ca2+]=480 nM). With all three electrode solutions, Na pump current was not significantly changed after 2–4 min in the presence of 10 M isoprenaline. -adrenergic pathways were still intact as evidenced by the two-fold increase in Cd2+-sensitive Ba2+ current through calcium channels that was observed in the presence of isoprenaline. Thus, -adrenergic stimulation does not appear to directly regulate Na,K-ATPase activity in rat ventricular myocytes.  相似文献   
25.
26.
The Usher syndromes are genetically distinct disorders which share specific phenotypic characteristics. This paper describes a set of clinical criteria recommended for the diagnosis of Usher syndrome type I and Usher syndrome type II. These criteria have been adopted by the Usher Syndrome Consortium and are used in studies reported by members of this Consortium. © 1994 Wiley-Liss, Inc.  相似文献   
27.
In one patient, an epithelioid cell nevus of the conjunctiva contained numerous large, unpigmented, mononucleated, binucleated, and multinucleated benign-appearing nevus cells with abundant cytoplasm and frequent intranuclear vacuoles. Despite their overall size, the cells manifested a low nuclear-cytoplasmic ratio. After a partial excision of the lesion, the remainder spontaneously regressed during a two-year period. Another patient's lesion was dominated by a proliferation of spindle nevus cells developing in a long-standing epibulbar nevus. The spindle cells were moderately pigmented, frequently located within walls of epithelial inclusion cysts, and had benign cytologic features. Finally, in a third patient with the cutaneous B-K mole syndrome, a dysplastic conjunctival nevus developed that featured intraepithelial, atypical melanocytic proliferation with superficial colonization of the substantia propria. This portion coexisted with a deeper, preexistent lesion in the substantia propria that was comprised of orderly nests of unpigmented cuboidal nevus cells surrounded by pigmented, spindle-shaped blue nevus cells--a so-called "mixed nevus."  相似文献   
28.
ContextMolecular biomarkers aim to address the established limitations of clinicopathologic factors to accurately risk stratify patients with prostate cancer (PCa). Questions remain as to whether sufficient evidence supports adoption of these biomarkers for clinical use.ObjectiveTo perform a systematic review of the available evidence supporting the clinical utility of the Decipher genomic classifier (GC).Evidence acquisitionThe review was performed as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines by searching PubMed and conference abstracts from January 2010 to June 2020. Evidence was then graded using the criteria of Simon et al (Simon RM, Paik S, Hayes DF. Use of archived specimens in evaluation of prognostic and predictive biomarkers. J Natl Cancer Inst 2009;101:1446–52) and American Urology Association (AUA) criteria.Evidence synthesisIn total, 42 studies and 30 407 patients were included. GC performance data were available for localized, postprostatectomy, nonmetastatic castration-resistant, and metastatic hormone-sensitive PCa as part of retrospective studies (n = 12 141), prospective registries (n = 17 053), and prospective and post hoc randomized trial analyses (n = 1213). In 32 studies (n = 12 600), the GC was independently prognostic for all study endpoints (adverse pathology, biochemical failure, metastasis, and cancer-specific and overall survival) on multivariable analysis and improved the discrimination over standard of care in 24 studies (n = 8543). GC use changed the management in active surveillance (number needed to test [NNT] = 9) and postprostatectomy (NNT = 1.5–4) settings in five studies (n = 4331). Evidence strength was levels 1 and 2 by the Simon criteria for all disease states other than high-risk PCa, and grades A and B by AUA criteria depending on disease state.ConclusionsConsistent data are now present from diverse levels of evidence, which when viewed together, have demonstrated clinical utility of the GC in PCa. The utility of the GC is strongest for intermediate-risk PCa and postprostatectomy decision-making.Patient summaryIn this paper, we review the evidence of the Decipher genomic classification tool for men with prostate cancer. We found consistent evidence that the test helps identify which cancers are more or less aggressive, which in turn aids in personalized treatment decision-making.  相似文献   
29.
IntroductionAs we progress to an era when patient autonomy and shared decision-making are highly valued, there is a need to also have effective patient-centered communication tools. Radiology reports are designed for clinicians and can be very technical and difficult for patients to understand. It is important for patients to understand their magnetic resonance imaging (MRI) report in order to make an informed treatment decision with their physician. Therefore, we aimed to create a patient-centered prostate MRI report to give our patients a better understanding of their clinical condition.MethodsA prototype patient-centered radiology report (PACERR) was created by identifying items to include based on opinions sought from a group of patients undergoing prostate MRI and medical experts. Data was collected in semi-structured interviews using a salient belief question. A prototype PACERR was created in collaboration with human factors engineering and design, medical imaging, biomedical informatics, and cancer patient education groups.ResultsFifteen patients and eight experts from urology, radiation oncology, radiology, and nursing participated in this study. Patients were particularly interested to have a report with laymen terms, concise language, contextualization of values, definitions of medical terms, and next course of action. Everyone believed the report should include the risk of MRI findings actually being cancer in the subsequent biopsy.ConclusionsA prostate MRI PACERR has been developed to communicate the most important findings relevant to decision-making in prostate cancer using patient-oriented design principles. The ability of this tool to improve patient knowledge and communication will be explored.  相似文献   
30.
BACKGROUND: Heartburn, a common symptom, is self-treated with oral antacids. Efficacy of antacids has not been demonstrated for individual, spontaneous heartburn episodes. METHODS: We conducted a double-blind, randomized, placebo-controlled, parallel-group study of self-directed treatment for episodic heartburn comparing famotidine (FAM) 5, 10, or 20 mg and antacid (11 mEq ANC) to placebo (PBO) during a 4-week period. Twenty-nine US investigators enrolled a total of 565 outpatients, ages 18--81 years (mean 44.1 years) with heartburn but not seeking care for heartburn. Treatment of spontaneous heartburn episodes was permitted as needed, up to twice daily, with self-administered test drug. An open-label, backup antacid was provided to use if test drug did not provide adequate relief. Patients assessed heartburn relief hourly and recorded use of backup antacid. Relief was defined as complete relief of symptoms without the use of backup antacid. RESULTS: The media proportion of episodes relieved was: PBO, 41%; FAM 5 mg, 59%, 0.05 less-than-or-equal p < 0.10; FAM 10 mg, 70%, p < 0.001; FAM 20 mg, 69%, p < 0.001; antacid, 62%, p < 0.05 (p-values versus PBO). Supplemental analyses incorporating time to relief confirmed that famotidine and antacid provided more rapid and more frequent relief than placebo (odds ratio for relief relative to PBO: FAM 5 mg, 1.55, p = 0.003; FAM 10 mg, 1.94, p < 0.001; FAM 20 mg, 2.13, p < 0.001; antacid 1.57, p = 0.003). The tolerability profile was similar with famotidine, antacid, and placebo. CONCLUSIONS: The positive results with antacid demonstrated for the first time the efficacy of antacid in self-treatment of individual heartburn episodes and provided internal validation of this study paradigm. Patients in this study self-medicated effectively using low doses of famotidine on an as needed basis for spontaneous episodes of heartburn.  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