320 resultados para poly(vinyl alcohol)


Relevância:

20.00% 20.00%

Publicador:

Resumo:

A new method for fabricating hydrogels with intricate control over hierarchical 3D porosity using micro-fiber porogens is presented. Melt electrospinning writing of poly(ε-caprolactone) is used to create the sacrificial template leading to hierarchical structuring consisting of pores inside the denser poly(2-oxazoline) hydrogel mesh. This versatile approach provides new opportunities to create well-defined multilevel control over interconnected pores with diameters in the lower micrometer range inside hydrogels with potential applications as cell scaffolds with tunable diffusion and transport of, e.g. nutrients, growth factors or therapeutics.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Stress is a major driving force in alcohol use disorders (AUDs). It influences how much one consumes, craving intensity and whether an abstinent individual will return to harmful alcohol consumption. We are most vulnerable to the effects of stress during early development, and exposure to multiple traumatic early life events dramatically increases the risk for AUDs. However, not everyone exposed to early life stress will develop an AUD. The mechanisms determining whether an individual’s brain adapts and becomes resilient to the effects of stress or succumbs and is unable to cope with stress remain elusive. Emerging evidence suggests that neuroplastic changes in the nucleus accumbens (NAc) following early life stress underlie the development of AUDs. This review discusses the impact of early life stress on NAc structure and function, how these changes affect cholinergic signaling within the mesolimbic reward pathway and the role nicotinic acetylcholine receptors (nAChRs) play in this process. Understanding the neural pathways and mechanism determining stress resilience or susceptibility will improve our ability to identify individuals susceptible to developing AUDs, formulate cognitive interventions to prevent AUDs in susceptible individuals and to elucidate and enhance potential therapeutic targets, such as the nAChRs, for those struggling to overcome an AUD.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background Many Internet-based treatments for depression and for alcohol misuse have a positive impact, yet little is known about how these treatments work. Most research on web-based interventions involves efficacy trials which, while important, offer little explanation about how people perceive and use online programs. Objective This study aimed to undertake a qualitative exploration of participants' experience, perceived impact and use of an integrated web-based program for comorbid depression and alcohol misuse. Specifically, it explored users' perspectives on the intensity of their treatment and the level of support they received. Methods Interviewees were drawn from participants in a randomised controlled trial of the OnTrack web-based treatment for depression and alcohol misuse, which compared Brief Self-Guided, Comprehensive Self-Guided and Comprehensive Therapist-Assisted versions of the program. Twenty-nine people (9–11 from each condition) completed semi-structured telephone interviews asking about their impressions and experiences with the program. Interview transcriptions were subject to a 6-step thematic analysis, employing a conceptual matrix to identify thematic differences across groups. Results Positive experiences and outcomes were more pronounced among participants receiving the comprehensive treatments than the brief one, but other responses were relatively consistent across conditions. A major theme was a wish for more individualisation and human contact, even in participants receiving emailed assistance. Some confused follow-up research assessments with therapist support. There was little correspondence between the perceived impact of the program and the amount reportedly completed, and some participants said they used strategies offline or completed exercises mentally. Conclusions This study highlighted discrepancies between how web-based treatments are intended to be used and how people actually engage with them. A challenge for the next wave of these interventions is the provision of individualised responses and coaching that retains an emphasis on self-management and constrains cost.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective To evaluate health practitioners’ confidence and knowledge of alcohol screening, brief intervention and referral after training in a culturally adapted intervention on alcohol misuse and well-being issues for trauma patients. Design Mixed methods, involving semi-structured interviews at baseline and a post-workshop questionnaire. Setting: Targeted acute care within a remote area major tertiary referral hospital. Participants Ten key informants and 69 questionnaire respondents from relevant community services and hospital-based health care professionals. Intervention Screening and brief intervention training workshops and resources for 59 hospital staff. Main outcome measures Self-reported staff knowledge of alcohol screening, brief intervention and referral, and satisfaction with workshop content and format. Results After training, 44% of participants reported being motivated to implement alcohol screening and intervention. Satisfaction with training was high, and most participants reported that their knowledge of screening and brief intervention was improved. Conclusion Targeted educational interventions can improve the knowledge and confidence of inpatient staff who manage patients at high risk of alcohol use disorder. Further research is needed to determine the duration of the effect and influence on practice behaviour. Ongoing integrated training, linked with systemic support and established quality improvement processes, is required to facilitate sustained change and widespread dissemination.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: To explore the effect of education and training on the delivery of alcohol screening and brief intervention and referral to high-risk patients in a hospital setting. Main outcome measures included; delivery of training; practice change in relation to staff performing alcohol screening, brief intervention and referrals. Methods: Observational study design using mixed methods set in a tertiary referral hospital. Pre-post assessment of medical records and semi-structured interviews with key informants. Results: Routine screening for substance misuse (9% pre / 71.4% post) and wellbeing concerns (6.6% pre / 15 % post) was more frequent following the introduction of resources and staff participation in educational workshops. There was no evidence of a concomitant increase in delivery of brief intervention or referrals to services. Implementation challenges, including time constraints and staff attitudes, and enablers such as collaboration and visible pathways, were identified. Conclusion: Rates of patient screening increased, however barriers to delivery of brief intervention and referrals remained. Implementation strategies targeting specific barriers and enablers to introducing interventions are both required to improve the application of secondary prevention for patients in acute settings. Implications: Educational training, formalised liaison between services, systematised early intervention protocols, and continuous quality improvement processes will progress service delivery in this area.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Engineering the production of polyhydroxyalkanoates (PHAs) into high biomass bioenergy crops has the potential to provide a sustainable supply of bioplastics and energy from a single plant feedstock. One of the major challenges in engineering C-4 plants for the production of poly[(R)-3-hydroxybutyrate] (PHB) is the significantly lower level of polymer produced in the chloroplasts of mesophyll (M) cells compared to bundle sheath (BS) cells, thereby limiting the full PHB yield-potential of the plant. In this study, we provide evidence that the access to substrate for PHB synthesis may limit polymer production in M chloroplasts. Production of PHB in M cells of sugarcane is significantly increased by replacing -ketothiolase, the first enzyme in the bacterial PHA pathway, with acetoacetyl-CoA synthase. This novel pathway enabled the production of PHB reaching an average of 6.3% of the dry weight of total leaf biomass, with levels ranging from 3.6 to 11.8% of the dry weight (DW) of individual leaves. These yields are more than twice the level reported in PHB-producing sugarcane containing the -ketothiolase and illustrate the importance of producing polymer in mesophyll plastids to maximize yield. The molecular weight of the polymer produced was greater than 2x10(6)Da. These results are a major step forward in engineering a high biomass C-4 grass for the commercial production of PHB.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Three major changes in drink driving enforcement have occurred in South Australia since 1981. The effect of these changes on a number of surrogate measures of alcohol involvement in accidents were investigated. The surrogates included alcohol involvement of driver fatalities, and combinations of casualty, serious casualty, single vehicle and nighttime accidents. Data from previous studies were also cited. It was found that relationships between surrogate measures were inconsistent, and incompatible with assumptions about drink driving levels and related accidents. It was concluded that until these effects are understood the use of surrogate measures should be treated with caution.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A one-step thermal extrusion process has been investigated for the modification of starch with alcohol in order to improve the film properties. Unmodified starch/glycerol mixtures containing Methanol (MetOH), ethanol (EtOH) and their combinations (5, 10 and 15 wt%) were thermally extruded to produce thermoplastic. The final hot-pressed film showed increased stiffness and crystallinity, while having decreased moisture uptake due to oxidation and alcohol complexing molecular interactions. The Young’s Modulus, tensile strength and elongation at break increased by 60%, 15% and 32% respectively, for 5 wt% MetOH derived film, compared to the control. The film moisture content was reduced by up to 15 wt% for 5 wt% EtOH-derived film. Generally the crystallinity increased in the alcohol-derived films due to an increased complexing of alcohol with starch forming the VH polymorph. Fourier transform infra-red (FTIR) and proton nuclear magnetic resonance (1HNMR) spectroscopic analysis were used to discuss the molecular interactions between the starch and alcohol molecules.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Alcohol consumption is a moderately heritable trait, but the genetic basis in humans is largely unknown, despite its clinical and societal importance. We report a genome-wide association study meta-analysis of approximately 2.5 million directly genotyped or imputed SNPs with alcohol consumption (gram per day per kilogram body weight) among 12 population-based samples of European ancestry, comprising 26,316 individuals, with replication genotyping in an additional 21,185 individuals. SNP rs6943555 in autism susceptibility candidate 2 gene (AUTS2) was associated with alcohol consumption at genome-wide significance (P = 4 x 10(-8) to P = 4 x 10(-9)). We found a genotype-specific expression of AUTS2 in 96 human prefrontal cortex samples (P = 0.026) and significant (P < 0.017) differences in expression of AUTS2 in whole-brain extracts of mice selected for differences in voluntary alcohol consumption. Down-regulation of an AUTS2 homolog caused reduced alcohol sensitivity in Drosophila (P < 0.001). Our finding of a regulator of alcohol consumption adds knowledge to our understanding of genetic mechanisms influencing alcohol drinking behavior.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Purpose Social marketing benchmark criteria were used to understand the extent to which single-substance alcohol education programmes targeting adolescents in middle and high school settings sought to change behaviour, utilised theory, included audience research and applied the market segmentation process. The paper aims to discuss these issues. Design/methodology/approach A systematic literature review retrieved a total of 1,495 identified articles; 565 duplicates were removed. The remaining 930 articles were then screened. Articles detailing formative research or programmes targeting multiple substances, parents, families and/or communities, as well as elementary schools and universities were excluded. A total of 31 articles, encompassing 16 qualifying programmes, were selected for detailed evaluation. Findings The majority of alcohol education programmes were developed on the basis of theory and achieved short- and medium-term behavioural effects. Importantly, most programmes were universal and did not apply the full market segmentation process. Limited audience research in the form of student involvement in programme design was identified. Research limitations/implications This systematic literature review focused on single-substance alcohol education programmes targeted at middle and high school student populations, retrieving studies back to the year 2000. Originality/value The results of this systematic literature review indicate that application of the social marketing benchmark criteria of market segmentation and audience research may represent an avenue for further extending alcohol education programme effectiveness in middle and high school settings.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Alcohol addiction is a debilitating disorder producing maladaptive changes in the brain, leading drinkers to become more sensitive to stress and anxiety. These changes are key factors contributing to alcohol craving and maintaining a persistent vulnerability to relapse. Serotonin (5-Hydroxytryptamine, 5-HT) is a monoamine neurotransmitter widely expressed in the central nervous system where it plays an important role in the regulation of mood. The serotonin system has been extensively implicated in the regulation of stress and anxiety, as well as the reinforcing properties of all of the major classes of drugs of abuse, including alcohol. Dysregulation within the 5-HT system has been postulated to underlie the negative mood states associated with alcohol use disorders. This review will describe the serotonergic (5-HTergic) neuroplastic changes observed in animal models throughout the alcohol addiction cycle, from prenatal to adulthood exposure. The first section will focus on alcohol-induced 5-HTergic neuroadaptations in offspring prenatally exposed to alcohol and the consequences on the regulation of stress/anxiety. The second section will compare alterations in 5-HT signalling induced by acute or chronic alcohol exposure during adulthood and following alcohol withdrawal, highlighting the impact on the regulation of stress/anxiety signalling pathways. The third section will outline 5-HTergic neuroadaptations observed in various genetically-selected ethanol preferring rat lines. Finally, we will discuss the pharmacological manipulation of the 5-HTergic system on ethanol- and anxiety/stress-related behaviours demonstrated by clinical trials, with an emphasis on current and potential treatments.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND The current impetus for developing alcohol and/or other drugs (AODs) workplace policies in Australia is to reduce workplace AOD impairment, improve safety, and prevent AOD-related injury in the workplace. For these policies to be effective, they need to be informed by scientific evidence. Evidence to inform the development and implementation of effective workplace AOD policies is currently lacking. There does not currently appear to be conclusive evidence for the effectiveness of workplace AOD policies in reducing impairment and preventing AOD-related injury. There is also no apparent evidence regarding which factors facilitate or impede the success of an AOD policy, or whether, for example, unsuccessful policy outcomes were due to poor policy or merely poor implementation of the policy. It was the aim of this research to undertake a process, impact, and outcome evaluation of a workplace AOD policy, and to contribute to the body of knowledge on the development and implementation of effective workplace AOD policies. METHODS The research setting was a state-based power-generating industry in Australia between May 2008 and May 2010. Participants for the process evaluation study were individuals who were integral to either the development or the implementation of the workplace AOD policy, or both of these processes (key informants), and comprised the majority of individuals who were involved in the process of developing and/or implementing the workplace AOD policy. The sample represented the two main groups of interest—management and union delegates/employee representatives—from all three of the participating organisations. For the impact and outcome evaluation studies, the population included all employees from the three participating organisations, and participants were all employees who consented to participate in the study and who completed both the pre-and post-policy implementation questionnaires. Qualitative methods in the form of interviews with key stakeholders were used to evaluate the process of developing and implementing the workplace AOD policy. In order to evaluate the impact of the policy with regard to the risk factors for workplace AOD impairment, and the outcome of the policy in terms of reducing workplace AOD impairment, quantitative methods in the form of a non-randomised single group pre- and post-test design were used. Changes from Time 1 (pre) to Time 2 (post) in the risk factors for workplace AOD impairment, and changes in the behaviour of interest—(self-reported) workplace AOD impairment—were measured. An integration of the findings from the process, impact, and outcome evaluation studies was undertaken using a combination of qualitative and quantitative methods. RESULTS For the process evaluation study Study respondents indicated that their policy was developed in the context of comparable industries across Australia developing workplace AOD policies, and that this was mainly out of concern for the deleterious health and safety impacts of workplace AOD impairment. Results from the process evaluation study also indicated that in developing and implementing the workplace AOD policy, there were mainly ‗winners', in terms of health and safety in the workplace. While there were some components of the development and implementation of the policy that were better done than others, and the process was expensive and took a long time, there were, overall, few unanticipated consequences to implementing the policy and it was reported to be thorough and of a high standard. Findings also indicated that overall the policy was developed and implemented according to best-practice in that: consultation during the policy development phase (with all the main stakeholders) was extensive; the policy was comprehensive; there was universal application of the policy to all employees; changes in the workplace (with regard to the policy) were gradual; and, the policy was publicised appropriately. Furthermore, study participants' responses indicated that the role of an independent external expert, who was trusted by all stakeholders, was integral to the success of the policy. For the impact and outcome evaluation studies Notwithstanding the limitations of pre- and post-test study designs with regard to attributing cause to the intervention, the findings from the impact evaluation study indicated that following policy implementation, statistically significant positive changes with regard to workplace AOD impairment were recorded for the following variables (risk factors for workplace AOD impairment): Knowledge; Attitudes; Perceived Behavioural Control; Perceptions of the Certainty of being punished for coming to work impaired by AODs; Perceptions of the Swiftness of punishment for coming to work impaired by AODs; and Direct and Indirect Experience with Punishment Avoidance for workplace AOD impairment. There were, however, no statistically significant positive changes following policy implementation for Behavioural Intentions, Subjective Norms, and Perceptions of the Severity of punishment for workplace AOD impairment. With regard to the outcome evaluation, there was a statistically significant reduction in self-reported workplace AOD impairment following the implementation of the policy. As with the impact evaluation, these findings need to be interpreted in light of the limitations of the study design in being able to attribute cause to the intervention alone. The findings from the outcome evaluation study also showed that while a positive change in self-reported workplace AOD impairment following implementation of the policy did not appear to be related to gender, age group, or employment type, it did appear to be related to levels of employee general alcohol use, cannabis use, site type, and employment role. Integration of the process, impact, and outcome evaluation studies There appeared to be qualitative support for the relationship between the process of developing and implementing the policy, and the impact of the policy in changing the risk factors for workplace AOD impairment. That is, overall the workplace AOD policy was developed and implemented well and, following its implementation, there were positive changes in the majority of measured risk factors for workplace AOD impairment. Quantitative findings lend further support for a relationship between the process and impact of the policy, in that there was a statistically significant association between employee perceived fidelity of the policy (related to the process of the policy) and positive changes in some risk factors for workplace AOD impairment (representing the impact of the policy). Findings also indicated support for the relationship between the impact of the policy in changing the risk factors for workplace AOD impairment and the outcome of the policy in reducing workplace AOD impairment: positive changes in the risk factors for workplace AOD impairment (impact) were related to positive changes in self reported workplace AOD impairment (representing the main goal and outcome of the policy). CONCLUSIONS The findings from the research indicate support for the conclusion that the policy was appropriately implemented and that it achieved its objectives and main goal. The Doctoral research findings also addressed a number of gaps in the literature on workplace AOD impairment, namely: the likely effectiveness of AOD policies for reducing AOD impairment in the workplace, which factors in the development and implementation of a workplace AOD policy are likely to facilitate or impede the effectiveness of the policy to reduce workplace AOD impairment, and which employee groups are less likely to respond well to policies of this type. The findings from this research not only represent an example of translational, applied research—through the evaluation of the study industry's policy—but also add to the body of knowledge on workplace AOD policies and provide policy-makers with evidence which may be useful in the development and implementation of effective workplace AOD policies. Importantly, the findings espouse the importance of scientific evidence in the development, implementation, and evaluation of workplace AOD policies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Estimated 638,400 persons suffered a work-related injury or illness in 2009-2010 and 337 lost their lives as a result in 2009-2010. In 2013-2014, there were 186 fatalities with 29 (16%) occurring in construction. Very little is known about what proportion of accidents are directly attributable to the effects of AOD. Anecdotal evidence highlights issues of AOD and its association with safety risk on construction sites. Research Objective: • To scientifically evaluate the relationship between the use of AOD and the safety impacts within the Australian construction industry to engender a cultural change in the workforce • A nationally consistent and collaborative approach involving government, employers and employees, unions and other key industry stakeholders

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Introduction The Elaborated Intrusion Theory of Desire holds that desires for functional and dysfunctional goals share a common form. Both are embodied cognitive events, characterised by affective intensity and frequency. Accordingly, we developed scales to measure motivational cognitions for functional goals (Motivational Thought Frequency, MTF; State Motivation, SM), based on the existing Craving Experience Questionnaire (CEQ). When applied to increasing exercise, MTF and SM showed the same three-factor structure as the CEQ (Intensity, Imagery, Availability). The current study tested the internal structure and concurrent validity of the MTF and SM Scales when applied to control of alcohol consumption (MTF-A; SM-A). Methods Participants (N = 417) were adult tertiary students, staff or community members who had recently engaged in high-risk drinking or were currently trying to control alcohol consumption. They completed an online survey comprising the MTF-A, SM-A, Alcohol Use Disorders Identification Test (AUDIT), Readiness to Change Questionnaire (RCQ) and demographics. Results Confirmatory Factor Analysis gave acceptable fit for the MTF-A, but required the loss of one SM-A item, and was improved by intercorrelations of error terms. Higher scores were associated with more severe problems on the AUDIT and with higher Contemplation and Action scores on the RCQ. Conclusions The MTF-A and SM-A show potential as measures of motivation to control drinking. Future research will examine their predictive validity and sensitivity to change. The scales' application to both increasing functional and decreasing dysfunctional behaviours is consistent with EI Theory's contention that both goal types operate in similar ways.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Thermally stable mesoporous TiO2/SiO2 hybrid films with pore size of 50 nm have been synthesized by adopting the polymeric micelle-assembly method. A triblock copolymer, poly(styrene-b-2-vinyl pyridine-b-ethylene oxide), which serves as a template for the mesopores, was utilized to form polymeric micelles. The effective interaction of titanium tetraisopropoxide (TTIP) and tetraethyl orthosilicate (TEOS) with the polymeric micelles enabled us to fabricate stable mesoporous films. By changing the molar ratio of TEOS and TTIP, several mesoporous TiO2/SiO2 hybrid films with different compositions can be synthesized. The presence of amorphous SiO2 phase effectively retards the growth of anatase TiO2 crystal in the pore walls and retains the original mesoporous structure, even at higher temperature (650 °C). These TiO2/SiO2 hybrid films are of very high quality, without any cracks or voids. The addition of SiO2 phase to mesoporous TiO2 films not only adsorbs more organic dyes, but also significantly enhances the photocatalytic activity compared to mesoporous pure TiO2 film without SiO2 phase.