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   23481篇
  免费   3092篇
  国内免费   570篇
耳鼻咽喉   404篇
儿科学   959篇
妇产科学   1115篇
基础医学   1873篇
口腔科学   219篇
临床医学   2297篇
内科学   2935篇
皮肤病学   183篇
神经病学   932篇
特种医学   536篇
外国民族医学   3篇
外科学   1319篇
综合类   2289篇
现状与发展   3篇
一般理论   1篇
预防医学   2986篇
眼科学   507篇
药学   3459篇
  13篇
中国医学   2404篇
肿瘤学   2706篇
  2024年   75篇
  2023年   574篇
  2022年   726篇
  2021年   1284篇
  2020年   1254篇
  2019年   1198篇
  2018年   1065篇
  2017年   1159篇
  2016年   1238篇
  2015年   1117篇
  2014年   1819篇
  2013年   2361篇
  2012年   1487篇
  2011年   1511篇
  2010年   1202篇
  2009年   1096篇
  2008年   1068篇
  2007年   1006篇
  2006年   859篇
  2005年   738篇
  2004年   602篇
  2003年   591篇
  2002年   436篇
  2001年   384篇
  2000年   265篇
  1999年   273篇
  1998年   232篇
  1997年   213篇
  1996年   165篇
  1995年   146篇
  1994年   131篇
  1993年   105篇
  1992年   119篇
  1991年   85篇
  1990年   89篇
  1989年   55篇
  1988年   58篇
  1987年   51篇
  1986年   44篇
  1985年   58篇
  1984年   37篇
  1983年   33篇
  1982年   29篇
  1981年   27篇
  1980年   16篇
  1979年   12篇
  1978年   12篇
  1977年   8篇
  1976年   10篇
  1973年   7篇
排序方式: 共有10000条查询结果,搜索用时 22 毫秒
1.
PurposeUnderstanding the value of genetic screening and testing for monogenic disorders requires high-quality, methodologically robust economic evaluations. This systematic review sought to assess the methodological quality among such studies and examined opportunities for improvement.MethodsWe searched PubMed, Cochrane, Embase, and Web of Science for economic evaluations of genetic screening/testing (2013-2019). Methodological rigor and adherence to best practices were systematically assessed using the British Medical Journal checklist.ResultsAcross the 47 identified studies, there were substantial variations in modeling approaches, reporting detail, and sophistication. Models ranged from simple decision trees to individual-level microsimulations that compared between 2 and >20 alternative interventions. Many studies failed to report sufficient detail to enable replication or did not justify modeling assumptions, especially for costing methods and utility values. Meta-analyses, systematic reviews, or calibration were rarely used to derive parameter estimates. Nearly all studies conducted some sensitivity analysis, and more sophisticated studies implemented probabilistic sensitivity/uncertainty analysis, threshold analysis, and value of information analysis.ConclusionWe describe a heterogeneous body of work and present recommendations and exemplar studies across the methodological domains of (1) perspective, scope, and parameter selection; (2) use of uncertainty/sensitivity analyses; and (3) reporting transparency for improvement in the economic evaluation of genetic screening/testing.  相似文献   
2.
Patient navigation is a strategy for overcoming barriers to reduce disparities and to improve access and outcomes. The aim of this umbrella review was to identify, critically appraise, synthesize, and present the best available evidence to inform policy and planning regarding patient navigation across the cancer continuum. Systematic reviews examining navigation in cancer care were identified in the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Cumulative Index of Nursing and Allied Health (CINAHL), Epistemonikos, and Prospective Register of Systematic Reviews (PROSPERO) databases and in the gray literature from January 1, 2012, to April 19, 2022. Data were screened, extracted, and appraised independently by two authors. The JBI Critical Appraisal Checklist for Systematic Review and Research Syntheses was used for quality appraisal. Emerging literature up to May 25, 2022, was also explored to capture primary research published beyond the coverage of included systematic reviews. Of the 2062 unique records identified, 61 systematic reviews were included. Fifty-four reviews were quantitative or mixed-methods reviews, reporting on the effectiveness of cancer patient navigation, including 12 reviews reporting costs or cost-effectiveness outcomes. Seven qualitative reviews explored navigation needs, barriers, and experiences. In addition, 53 primary studies published since 2021 were included. Patient navigation is effective in improving participation in cancer screening and reducing the time from screening to diagnosis and from diagnosis to treatment initiation. Emerging evidence suggests that patient navigation improves quality of life and patient satisfaction with care in the survivorship phase and reduces hospital readmission in the active treatment and survivorship care phases. Palliative care data were extremely limited. Economic evaluations from the United States suggest the potential cost-effectiveness of navigation in screening programs.  相似文献   
3.
IntroductionLung cancer (LC) is usually diagnosed at advanced stages with only a 12% 5-year survival. Trials as NLST and NELSON show a mortality decrease, which justifies implementation of lung cancer screening in risk population. Our objective was to show survival results of the largest LC screening program in Spain with low dosage computed tomography (LDCT).MethodsClinical records from International Early Lung Cancer Detection Program (IELCAP) at Valencia, Spain were analysed. This program recruited volunteers, ever-smokers aged 40-80 years, since 2008. Results are compared to those from other similar sizeable programs.ResultsA total of 8278 participants were screened with at least two-rounds until November 2020. A mean of 6 annual screening rounds were performed. We detected 239 tumours along 12-year follow-up. Adenocarcinoma was the most common histology, being 61.3% at stage I. The lung cancer prevalence and incidence proportion was 1.5% and 1.4%, respectively with an annual detection rate of 0.17. One-year survival and 10-year survival were 90% and 80.1%, respectively. Adherence was 96.84%.ConclusionLargest lung cancer screening in Spain shows that survival is improved when is performed in multidisciplinary team experienced in management of LC, and is comparable to similar screening programs.  相似文献   
4.
5.
目的:探讨健脾益肾方对非小细胞肺癌(NSCLC)细胞体外增殖凋亡的作用。方法:人NSCLC细胞系A549分为四组:空白对照组(仅加入细胞培养液)、阴性对照组(加入细胞,不进行中药处理)、实验组(加细胞加中药处理)。荧光定量PCR和Western blot分别检测Survivin、Bcl-2和Caspase-3的mRNA和蛋白表达。MTT检测细胞增殖;流式细胞术检测细胞凋亡。结果:与空白对照组相比,阴性对照组细胞在24、48、72 h的吸光度值明显升高,细胞凋亡率下降,Survivin和Bcl-2 mRNA和蛋白相对表达量上调,Caspase-3 mRNA和蛋白相对表达量下调,组间比较差异有统计学意义(P<0.05);而健脾益肾方处理的实验组24、48、72 h的吸光度值均显著降低,细胞凋亡率显著上升,Survivin和Bcl-2 mRNA和蛋白相对表达量下调,Caspase-3 mRNA和蛋白相对表达量上调,与空白对照组相比差异有统计学意义(P<0.05)。结论:健脾益肾方可通过下调Survivin和Bcl-2、上调Caspase-3表达诱导NSCLC细胞凋亡,并抑制肿瘤细胞的增殖,进而抑制NSCLC的发展。  相似文献   
6.
7.
通过对中医古籍中有关升降散论述的文献梳理,全面探讨其内涵。本方是在大黄、僵蚕为雏形的基础上增加蝉蜕、姜黄而成方,几经易名,终在杨璿《伤寒瘟疫条辨》中为后人所熟知。本方广泛用于治疗瘟疫,以丸剂、散剂为主,方便携带,便于服用;重用大黄旨在祛邪、逐秽;应用时视人之体质强弱和量其毒之轻重而判断用药多寡,并辅以米酒、生蜜等以顾护正气。杨璿将其由治疗“热疫”的专方扩展为治疗“表里三焦大热”的通用方剂,扩大了本方治疗疾病范围。  相似文献   
8.
Background: Self sampled HPV testing is a cervical cancer screening method . However, cytology in self-sampled specimen cannot be used as a triage test.  Therefore, other methods for triage should be considered. CyclinA1 (CCNA1) promoter methylation has strong association with cervical precancerous and cancerous lesion. The objective of this study was to compare the diagnostic value of CCNA1 and self-sampled specimen for detecting high-grade cervical intraepithelial lesions or worse (CIN2+). Materials and Methods: A cross sectional study was conducted. Women with abnormal cytology or positive for high risk HPV (hrHPV) indicated for colposcopic examination were enrolled.  Self-collected sampling for hrHPV DNA (SS-HPV) and CCNA1 were performed. hrHPV DNA testing was done by Cobas 4800 method. CCNA1 promoter methylation was detected by CCNA1 duplex methylation specific PCR. Histopathologic result as CIN2+ obtaining from colposcopic directed biopsy or excisional procedure  was considered as positive a gold standard. The results of hrHPV and CCNA1 were reported as positive or negative. Sensitivity specificity, positive predictive value, and negative predictive value of SS-HPV and CCNA1 were calculated by comparing the results with the gold standard. Results: Two hundreds and eighty women were recruited. High-grade cervical lesions and cervical cancer (CIN2+) were diagnosed in 21.8% (61 cases) of the patients. The most common type of hrHPV was non 16, 18 subtype, followed by HPV16 and 18. CCNA1 was positive in 13 patients out of whom, twelve were CIN2+. Sensitivity of CCNA1 was 19.7 % and its  specificity and accuracy were 99.5% and 82.14%, respectively.  The sensitivity of SS-HPV was 70.5%, and its  specificity and accuracy were 39.2% and 43.3%, respectively. Conclusion:  Due to high specificity and positive predictive value of CCNA1, it can be used as alarming sign of having high-grade cervical intraepithelial lesions, especially in patient who has positive hrHPV DNA test based on self-collected sampling.  相似文献   
9.
Purpose: Family psychosocial risk in pediatric oncology can be assessed using the Psychosocial Assessment Tool (PAT), a brief parent report screener based on the Pediatric Psychosocial Preventative Health Model (PPPHM; universal, targeted, and clinical). However, little is known about risk over the course of treatment and its association with medical and psychosocial healthcare utilization. Methods: Primary caregivers of children with cancer participated in this prospective multisite investigation, completing the PAT at diagnosis (T1; n = 396) and 6 months later (T2; n = 304). Healthcare utilization data were extracted from electronic health records. Results: The distribution of PPPHM risk levels at T1 and T2 was highly consistent for the samples. Two‐thirds of families remained at the same level of risk, 18% decreased and 16% increased risk level. Risk was not related to sociodemographic or treatment variables. The PAT risk score correlated with psychosocial contacts over the 6‐month period. Conclusions: Although the majority of families reported universal (low) risk on the PAT and were stable in their risk level over 6 months, reassessing risk is helpful in identifying those families who report higher level of risk during treatment than at diagnosis. PAT scores were related to psychosocial services that are provided to most but not all families and could be tailored more specifically to match risk and delivery of evidence‐based care.  相似文献   
10.
Study DesignClinical commentary.Introduction/PurposePain and movement are universally relevant phenomena that influence human experiences in readily observable ways. Improved understanding of pain-movement relationships can guide medical and rehabilitative approaches to recovery and decrease risk of dysfunctional long-term consequences of otherwise normal neuromuscular responses. Therefore, the overall intent of this article is to elucidate the relationships between pain and movement as they relate to clinical decision making.ConclusionsMotor output is highly adaptable, can be influenced by multiple mechanisms at various levels along the nervous system, and may vary between individuals despite similar diagnoses. Therefore, interventions need to be individualized and consider both the types of motor response observed (ie, whether the response is protective or maladaptive), and the patient's acute physical activity tolerance when prescribing exercise/movement.  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