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   132篇
  免费   4篇
教育   46篇
科学研究   37篇
各国文化   1篇
体育   19篇
文化理论   16篇
信息传播   17篇
  2023年   1篇
  2022年   2篇
  2021年   5篇
  2020年   3篇
  2019年   13篇
  2018年   9篇
  2017年   9篇
  2016年   9篇
  2015年   6篇
  2014年   6篇
  2013年   17篇
  2012年   8篇
  2011年   10篇
  2010年   4篇
  2009年   6篇
  2008年   5篇
  2007年   2篇
  2006年   2篇
  2004年   1篇
  2003年   3篇
  2002年   2篇
  1999年   2篇
  1998年   1篇
  1996年   1篇
  1994年   1篇
  1991年   1篇
  1990年   1篇
  1988年   1篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
排序方式: 共有136条查询结果,搜索用时 15 毫秒
1.

Introduction

Screening programs for colorectal cancer (CRC) are mainly based on a first-line fecal immunochemical test for hemoglobin (FIT). Fecal M2-type pyruvate kinase (M2-PK) has been evaluated in clinical settings showing promising results for early CRC detection. However, the impact of fecal M2-PK assessment on the performance of first-round CRC screening programs is not known. We investigated whether fecal M2-PK alone or in combination with FIT may improve CRC screening efficacy in the general population.

Materials and methods

A total of 1027 asymptomatic subjects (median age 66 [59-74] years; females 504 [49.1%]), identified through the general practitioners’ rosters, were invited for the collection of 2 fecal samples for FIT and M2-PK evaluation. Participants with at least positive one fecal test were referred for colonoscopy. Quality indicators for screening performance were calculated and analyzed using Fisher’s exact test.

Results

Overall, 572 subjects underwent both FIT and M2-PK assessment (participation rate 55.7%): 93 participants showed positive results for at least one test (positivity rate 16.3%). Only 10 patients were positive for both tests. Attendance rate to colonoscopy was 86.0% and a total of 65 adenomas and 7 cancers were detected. Combined use of FIT and fecal M2-PK permitted the identification of 18 more neoplasm (25%) without improving colonoscopy workload, as deduced by the comparable number needed to scope (P = 0.402).

Conclusion

The addition of M2-PK testing to FIT offers the potential to detect additional neoplasms that either do not bleed or only bleed intermittently without reducing participation rate and without increasing endoscopy workload.Key words: biomarker, colorectal cancer, occult blood, M2-type pyruvate kinase, screening  相似文献   
2.
Our model analyzes the effects of the interplay between environmental degradation and consumption choices on economic growth dynamics and on economic agents’ welfare. We show that if private goods can be consumed as substitutes for environmental goods, then economic growth may be fueled by environmental deterioration. In this context, undesirable economic growth may occur, characterized by an inverse correlation between aggregate capital accumulation and economic agents’ welfare.  相似文献   
3.
The purpose of this study was to analyse the raw lifting speed collected during four different resistance training exercises to assess the optimal sampling frequency. Eight physically active participants performed sets of Squat Jumps, Countermovement Jumps, Squats and Bench Presses at a maximal lifting speed. A linear encoder was used to measure the instantaneous speed at a 200 Hz sampling rate. Subsequently, the power spectrum of the signal was computed by evaluating its Discrete Fourier Transform. The sampling frequency needed to reconstruct the signals with an error of less than 0.1% was f99.9 = 11.615 ± 2.680 Hz for the exercise exhibiting the largest bandwidth, with the absolute highest individual value being 17.467 Hz. There was no difference between sets in any of the exercises. Using the closest integer sampling frequency value (25 Hz) yielded a reconstruction of the signal up to 99.975 ± 0.025% of its total in the worst case. In conclusion, a sampling rate of 25 Hz or above is more than adequate to record raw speed data and compute power during resistance training exercises, even under the most extreme circumstances during explosive exercises. Higher sampling frequencies provide no increase in the recording precision and may instead have adverse effects on the overall data quality.  相似文献   
4.
The present study examined the generalizability of the factor pattern, structural parameters, and latent structure of a multidimensional hierarchical model of ethnocultural empathy in males and females. The Scale of Ethnocultural Empathy (SEE) (Wang et al., 2003) was administered to a sample of 610 Italian undergraduates to examine the generalizability and reliability of its factor structure across gender, the psychometric properties and the validity of the scale. Two models were tested through multi-group confirmatory factor analysis (MGCFA): a confirmatory factor-analytic model that hypothesized a multidimensional model of ethnocultural empathy; and a structural equation model that proposed a multidimensional, hierarchical structure with global ethnocultural empathy as a superordinate construct that explained the covariances among the subdomains of the SEE. Both models satisfied multiple criteria for goodness-of-fit with the data. Full metric invariance of factor loadings and factor covariances, and partial invariance of error variances across gender for the four-factors model were supported. Scale reliability was also satisfactory, showing good internal consistency. As regard scale validity, evidence was found for a positive moderate association with a measure of general empathy and a negative high association with a measure of prejudice. Implications are discussed.  相似文献   
5.
The aim of this study was to analyze the effects of resistance training (RT) performed with 1 or 3 sets per exercise on osteosarcopenic obesity (OSO) syndrome parameters in older women. Sixty-two older women (68.0 ± 4.3 years, 26.8 ± 4.4 kg/m2) participated in a 12-week RT program. Participants were randomly assigned into one of the three groups: two training groups that performed either 1 set (G1S, n = 21) or 3 sets (G3S, n = 20) 3 times weekly, or a control group (CG, n = 21). Body composition was assessed by dual X-ray absorptiometry, strength was evaluated by 1 repetition maximum testing. The G3S presented significantly higher strength changes than G1S. The changes for percentage of body fat were higher for G3S compared to G1S. There was no difference in skeletal muscle mass between G3S and G1S, however both training groups displayed greater increases in this outcome compared to CG. There was no effect for bone mineral density. The overall analysis indicated higher (< 0.05) positive changes for G3S than G1S (composed Z-score: G3S = 0.62 ± 0.40; G1S = 0.11 ± 0.48). The results suggest that a 12-week RT period is effective to improve the risk factors of OSO, and that 3 sets induce higher improvements than a single set.  相似文献   
6.
Maintaining the microclimatic parameters at the desired value is essential for artefacts preservation. In order to control the status of the microclimatic parameters, a continuous monitoring of the indoor environmental provides conservators, curators, restorers, and lenders with an exact knowledge of the microclimatic conditions under which the works of art are kept. Moreover, the monitoring results give important information in order to make adequate changes to the control strategy of microclimatic parameters. From this point of view, monitoring is an essential tool to develop an actual preventive control programme aimed at maintaining the optimal microclimatic conditions for preservation. As a consequence, long-term monitoring has to be applied to prevent deterioration of works of art. The widespread opinion that a correct approach to the topic of microclimate control for artefacts preservation is not only and necessarily to provide buildings with sophisticated environmental control systems, but mainly to investigate the actual environmental dynamics and, before any structural intervention, to define the compatibility between the climate control potentials and the preservation requirements, has become more and more firm among the experts. Monitoring also allows to verify the capacity of the “building and Heating, Ventilation and Air Conditioning (HVAC)” system to maintain the desired thermo-hygrometric values within the operating conditions. To this aim, the Italian Standard UNI 10829 (1999) defining monitoring, elaboration and analysis of the microclimatic data as supporting actions for artefacts preservation, led to the need of a long-term monitoring and of a statistical approach to the data management. The approach proposed by the Italian Standard has been recently adopted by a European Standard (EN 15251, 2007). In accordance with the Standards mentioned above, in this paper an operational procedure to assess the thermo-hygrometric quality in museums is firstly synthetically presented and than applied to a case study. In particular, the procedure is developed in order to define the thermo-hygrometric quality level of the exhibition areas in the large museum complex of “Santa Maria della Scala” in Siena (Italy) during the international temporary exhibition “Duccio. La nascita della pittura senese” (“Duccio. The birth of Sienese Painting”).  相似文献   
7.
This paper proposes a price index for artists adjusted for the quality of the paintings, based on the ratio between the average market price and the average pre-sale estimate for paintings. We apply this methodology to a group of selected artists and schools presented in auctions worldwide in the period 1990–2001. A comparison with quality unadjusted and hedonic indices is also conducted.JEL Classification: C10, Z11  相似文献   
8.
9.
Processes of designing for systemic innovation for sustainable development (SD) through the lens of three long-term case studies are reported. All case studies, which originated from the SLIM (Social Learning for the Integrated Management and Sustainable Use of Water at Catchment Scale) Project, funded within the EU Fifth Framework Program (2001–2004), constitute inquiry pathways that are explored using a critical incident approach. The initial starting conditions for each inquiry pathway are compared; significant pathway dependencies are identified which foster the development of social learning processes locally, but constrain their uptake and embedding across the wider system of interest. In the first case study, in England & Wales, promising developments in the application of social learning approaches to river basin planning over an initial 3-year period were subsequently marginalised, only to resurface towards the end of the 10-year period of study. In the second, South African case study, significant spaces for social learning and innovation in integrated water resources management were opened up over a five year period but closed down again, primarily as the result of lack of policy support by national government. The third, Italian, case study was designed to assess options for adapting to climate change by opening up new learning spaces between researchers, stakeholders and policy makers. A case for investing in local level systemic innovation through social-learning praxis design approaches and in learning processes around well contextualised case-studies is supported. However, concomitant investment by policy makers in social learning as an alternative, but complementary, governance mechanism for systemic innovation for SD is needed.  相似文献   
10.
The phenomenon of entrepreneurial universities has received considerable attention over the last decades. An entrepreneurial orientation by academia might put regions and nations in an advantageous position in emerging knowledge-intensive fields of economic activity. At the same time, such entrepreneurial orientation requires reconciliation with the scientific missions of academia. Large-scale empirical research on antecedents of the entrepreneurial effectiveness of universities is scarce. This contribution examines the extent to which scientific productivity affect entrepreneurial effectiveness, taking into account the size of universities and the presence of disciplines, as well as the R&D intensity of the regional business environment (BERD). In addition, we assess the occurrence of trade-offs between different transfer mechanisms (contract research, patenting and spin off activity). The data used pertain to 105 European universities. Our findings reveal that scientific productivity is positively associated with entrepreneurial effectiveness. Trade-offs between transfer mechanisms do not reveal themselves; on the contrary, contract research and spin off activities tend to facilitate each other. Limitations and implications for future research are discussed.  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