732 resultados para Exploratory activity


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Nowadays, the emergence of resistance to the current available chemotherapeutic drugs by cancer cells makes the development of new agents imperative. The skin secretion of amphibians is a natural rich source of antimicrobial peptides (AMP), and researchers have shown that some of these wide spectrum molecules are also toxic to cancer cells. The aim of this study was to verify a putative anticancer activity of the AMP pentadactylin isolated for the first time from the skin secretion of the frog Leptodactylus labyrinthicus and also to study its cytotoxic mechanism to the murine melanoma cell line B16F10. The results have shown that pentadactylin reduces the cell viability of B16F10 cells in a dose-dependent manner. It was also cytotoxic to normal human fibroblast cells; nevertheless, pentadactylin was more potent in the first case. The studies of action mechanism revealed that pentadactylin causes cell morphology alterations (e.g., round shape and shrinkage morphology), membrane disruption, DNA fragmentation, cell cycle arrest at the S phase, and alteration of mitochondrial membrane potential, suggesting that B16F10 cells die by apoptosis. The exact mechanism that causes reduction of cell viability and cytotoxicity after treatment with pentadactylin is still unknown. In conclusion, as cancer cells become resilient to death, it is worthwhile the discovery of new drugs such as pentadactylin that induces apoptosis.

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Novel nanostructures such as vertically aligned carbon nanotube (CNT) arrays have received increasing interest as drug delivery carriers. In the present study, two CNT arrays with extreme surface wettabilities are fabricated and their effects on the release of recombinant human bone morphogenetic protein-2 (rhBMP-2) are investigated. It is found that the superhydrophilic arrays retained a larger amount of rhBMP-2 than the superhydrophobic ones. Further use of a poloxamer diffusion layer delayed the initial burst and resulted in a greater total amount of rhBMP-2 released from both surfaces. In addition, rhBMP-2 bound to the superhydrophilic CNT arrays remained bioactive while they denatured on the superhydrophobic surfaces. These results are related to the combined effects of rhBMP-2 molecules interacting with poloxamer and the surface, which could be essential in the development of advanced carriers with tailored surface functionalities.

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Active and collaborative learning are becoming essential strategies to attract, engage and retain students. These methods have been adopted within the Science and Engineering Faculty of Queensland University of Technology for use in its Science, Information Technology and Engineering degrees. This paper describes the adoption and application of these techniques in a specific first year unit in a new Bachelor of Information Technology degree which has majors in Computer Science and Information Systems. The paper reports on the design, development and implementation of this foundation subject and discusses how it uses active and collaborative learning to teach design thinking through a series of design challenges, and how it uses critiquing and reflection to ensure that students become more aware of design and team processes.

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Telomerase is an extremely important enzyme required for the immortalisation of tumour cells. Because the gene is activated in the vast majority of tumour tissues and remains unused in most somatic cells, it represents a marker with huge diagnostic, prognostic and treatment implications in cancer. This article summarises the basic structure and functions of telomerase and considers its clinical implications in colorectal and other cancers.

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The aims of the present study are to quantitatively analyze survivin expression, its clinicopathologic roles, and correlation with telomerase activity in a large cohort of patients with colorectal adenocarcinoma. Real-time polymerase chain reaction was used to quantitate expression level of survivin messenger RNA and human telomerase reverse transcriptase messenger RNA (telomerase activity) in 51 patients with colorectal adenocarcinomas. The findings were correlated with the clinicopathologic features of patients, which were prospectively collected into a computerized database. Survivin messenger RNA was expressed in all tumor samples. The level of expression in tumor tissues was increased in comparison with matched nontumor mucosa in the same patient (P = .01). The level of expression of survivin was significantly correlated with the level of human telomerase reverse transcriptase expression (P = .008) and size of the colorectal adenocarcinomas (P = .004). Survival of the patients with colorectal adenocarcinoma was associated with the TNM stages (P = .001) and not with the level of expression of survivin. Thus, survivin activity was altered in colorectal adenocarcinoma. The high prevalence of survivin expression and correlation with telomerase activity are important factors for consideration in gene targeting therapy for colorectal adenocarcinoma.

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Introduction The ultimate aim of Cochrane systematic reviews is to inform policy and practice decisions for better health outcomes. However, due to the increasing numbers of scientific publications, wading through the available evidence of both individual studies and systematic reviews can be challenging and overwhelming even for avid authors and readers. This paper briefly describes the first overview (a systematic review of reviews) of the Cochrane Public Health Group (CPHG) in development and proposes a way forward for the methodologies under consideration.

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Performance measurement in Australian philanthropic foundations is a hot topic. Foundation staff and board members are concerned with striking the right balance between their need for information with which to assess the effectiveness of their grant-making programs, and the costs in both time and money for grantees. Influenced by normative pressures, the increasing size and professionalism of the Australian philanthropic sector, and trends from the U.S.A and the U.K, foundations are talking amongst themselves, seeking expert advice and training, consulting with grantees and trying different approaches. Many resources examine methods of data collection, measurement or analysis. Our study instead treads into less charted but important territory: the motivations and values that are shaping the debate about performance measurement. In a series of 40 interviews with foundations from Queensland, New South Wales, Victoria and South Australia, we asked whether they felt under pressure to measure performance and if so, why. We queried whether everyone in the foundation shared the same views on the purposes of performance measurement; and the ways in which the act of performance measurement changed their grant-making, their attitude to risk, their relationship with grantees and their collaborations with other funders. Unsurprisingly, a very diverse set of approaches to performance measurement were revealed.

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Background Physical activity (PA) has a positive association with health-related quality of life (HRQL) in the general population. The association between PA and HRQL in those with poor mental health is less clear. Purpose To examine the concurrent and prospective dose-response relationships between total physical activity (TPA) and walking only with HRQL in women aged 50-55 with depressive symptoms in 2001. Methods Participants were 1904 women born in 1946-1951 who completed mailed surveys for the Australian Longitudinal Study on Women's Health in 2001, 2004, 2007 and 2010 and who, in 2001, reported depressive symptoms. At each time point, they reported their weekly minutes of walking, moderate PA, and vigorous PA. A summary TPA score was created that accounted for differences in energy expenditure among the three PA types. Mixed models were used to examine associations between TPA and HRQL (SF-36 component and subscale scores) and between walking and HRQL, for women who reported walking as their only PA. Analyses were conducted in 2013-2014. Results Concurrently, higher levels of TPA and walking were associated with better HRQL (p<0.05). The strongest associations were found for physical functioning, vitality, and social functioning subscales. In prospective models, associations were attenuated, yet compared with women doing no TPA or walking, women doing “sufficient” TPA or walking had significantly better HRQL over time for most SF-36 scales. Conclusions This study extends previous work by demonstrating trends between both TPA and walking and HRQL in women reporting depressive symptoms.

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Objective Exercise has the potential to offer a range of health benefits in addition to improving healing outcomes for people with venous leg ulcers. However despite evidence based recommendations, most of these individuals do not engage in regular exercise. The aim of this study was to gain an understanding of the perspectives of adults with venous leg ulcers, in relation to exercise. Method This was a qualitative design using semi-structured interviews and discussions. Ten participants with venous leg ulceration volunteered to participate. Recruitment was through a specialist wound clinic. Verbatim data were collected by an experienced moderator using a semi-structured guide. Data saturation was reached after three group discussions and two interviews. A random selection of transcripts was sent back to the participants for verification. Thematic content analysis was used to determine major themes and categories. Two transcripts were independently analysed, categories and themes independently developed, cross checked and found comparable. Remaining transcripts were analysed using developed categories and codes. Results Regardless of their current exercise routine, participants reported exercising prior to venous leg ulceration and expressed an interest in either becoming active or maintaining an active lifestyle. Overall four themes emerged from the findings: i) participant understanding of the relationship between chronic venous insufficiency and exercise patterns, ii) fear of harm impacts upon positive beliefs and attitudes to exercise, iii) perceived factors limit exercise and iv) structured management facilitates exercise. Conclusion The value of exercise in improving outcomes in venous leg ulcers lies in its capacity to promote venous return and reduce the risk of secondary conditions in this population. Despite motivation and interest in being exercise active, people with venous leg ulcers report many obstacles. Further exploration of mechanisms that assist this patient population and promote understanding about management of barriers, coupled with promotion of enabling factors is vital for improving their exercise participation.

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Vehicle traffic through roadwork sites creates a hazardous work environment, with speed limit noncompliance a major contributor to the high risk and high severity of roadwork crashes. This paper examines responses to an online survey to better understand the factors underlying drivers’ work zone speed choices. Drivers’ stated speed choice was compared between two photographs of the same work zone section – one with workers and machinery present and another with no visible activity. Drivers also provided comments on any aspect of roadwork safety they thought was important. A paired t-test of stated speed choice revealed that significantly lower mean speeds were nominated when workers and machinery were clearly present and active (41.7 vs 53.5 km/h, p<0.01). Participants expressed concern about roadwork signage and reduced speed limits being left in place when there was no apparent work activity. Driver perceptions, and thus compliance, may be improved through technological and operational changes.