Honeycomb nanogold networks with highly active sites

The formation of macroporous honeycomb gold using an electrochemically generated hydrogen bubble template is described. The synthesis procedure induces the formation of highly active surfaces with enhanced electrocatalytic and surface enhanced Raman scattering properties.

Formation of nanostructured porous Cu-Au surfaces : the influence of cationic sites on (electro)-catalysis

The fabrication of nanostructured bimetallic materials through electrochemical routes offers the ability to control the composition and shape of the final material that can then be effectively applied as (electro)-catalysts. In this work a clean and transitory hydrogen bubble templating method is employed to generate porous Cu–Au materials with a highly anisotropic nanostructured interior. Significantly, the co-electrodeposition of copper and gold promotes the formation of a mixed bimetallic oxide surface which does not occur at the individually electrodeposited materials. Interestingly, the surface is dominated by Au(I) oxide species incorporated within a Cu2O matrix which is extremely effective for the industrially important (electro)-catalytic reduction of 4-nitrophenol. It is proposed that an aurophilic type of interaction takes place between both oxidized gold and copper species which stabilizes the surface against further oxidation and facilitates the binding of 4-nitrophenol to the surface and increases the rate of reaction. An added benefit is that very low gold loadings are required typically less than 2 wt% for a significant enhancement in performance to be observed. Therefore the ability to create a partially oxidized Cu–Au surface through a facile electrochemical route that uses a clean template consisting of only hydrogen bubbles should be of benefit for many more important reactions.

Decoration of active sites to create bimetallic surfaces and its implication for electrochemical processes

The creation of electrocatalysts based on noble metals has received a significant amount of research interest due to their extensive use as fuel cell catalysts and electrochemical sensors. There have been many attempts to improve the activity of these metals through creating nanostructures, as well as post-synthesis treatments based on chemical, electrochemical, sonochemical and thermal approaches. In many instances these methods result in a material with active surface states, which can be considered to be adatoms or clusters of atoms on the surface that have a low lattice co-ordination number making them more prone to electrochemical oxidation at a wide range of potentials that are significantly less positive than those of their bulk metal counterparts. This phenomenon has been termed pre-monolayer oxidation and has been reported to occur on a range of metallic surfaces. In this work we present findings on the presence of active sites on Pd that has been: evaporated as a thin film; electrodeposited as nanostructures; as well as commercially available Pd nanoparticles supported on carbon. Significantly, advantage is taken of the low oxidation potential of these active sites whereby bimetallic surfaces are created by the spontaneous deposition of Ag from AgNO3 to generate Pd/Ag surfaces. Interestingly this approach does not increase the surface area of the original metal but has significant implications for its further use as an electrode material. It results in the inhibition or promotion of electrocatalytic activity which is highly dependent on the reaction of interest. As a general approach the decoration of active catalytic materials with less active metals for a particular reaction also opens up the possibility of investigating the role of the initially present active sites on the surface and identifying the degree to which they are responsible for electrocatalytic activity.

Dynamic contrast-enhanced magnetic resonance imaging as a biomarker for the pharmacological response of PTK787/ZK 222584, an inhibitor of the vascular endothelial growth factor receptor tyrosine kinases, in patients with advanced colorectal cancer and liver metastases: Results from two phase I studies

Purpose: PTK787/ZK 222584 (PTK/ZK), an orally active inhibitor of vascular endothelial growth factor (VEGF) receptor tyrosine kinases, inhibits VEGF-mediated angiogenesis. The pharmacodynamic effects of PTK/ZK were evaluated by assessing changes in contrast-enhancement parameters of metastatic liver lesions using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in patients with advanced colorectal cancer treated in two ongoing, dose-escalating phase I studies. Patients and Methods: Twenty-six patients had DCE-MRI performed at baseline, day 2, and at the end of each 28-day cycle. Doses of oral PTK/ZK ranged from 50 to 2000 mg once daily. Tumor permeability and vascularity were assessed by calculating the bidirectional transfer constant (Ki). The percentage of baseline Ki (% of baseline Ki) at each time point was compared with pharmacokinetic and clinical end points. Results: A significant negative correlation exists between the % of baseline Ki and increase in PTK/ZK oral dose and plasma levels (P = .01 for oral dose; P = .0001 for area under the plasma concentration curve at day 2). Patients with a best response of stable disease had a significantly greater reduction in Ki at both day 2 and at the end of cycle 1 compared with progressors (mean difference in % of baseline Ki, 47%, P = .004%; and 51%, P = .006; respectively). The difference in % of baseline Ki remained statistically significant after adjusting for baseline WHO performance status. Conclusion: These findings should help to define a biologically active dose of PTK/ZK. These results suggest that DCE-MRI may be a useful biomarker for defining the pharmacological response and dose of angiogenesis inhibitiors, such as PTK/ZK, for further clinical development. © 2003 by American Society of Clinical Oncology.

Much ado about nothing? Tracing the progress of innovations borne on enterprise social network sites

Enterprise social networks are organizationally bounded online platforms for users to interact with another and maintain interpersonal relationships. The allure of these technologies is often seen in intra-organizational communication, collaboration and innovation. How these technologies actually support organizational innovation efforts remains unclear. A specific challenge is whether digital content on these platforms converts to actual innovation development efforts. In this study we set out to examine innovation-centric content flows on enterprise social networking platforms, and advance a conceptual model that seeks to explain which innovation conveyed in the digital content will traverse from the digital platform into regular processes. We describe important constructs of our model and offer strategies for the operationalization of the constructs. We conclude with an outlook to our ongoing empirical study that will explore and validate the key propositions of our model, and we sketch some potential implications for industry and academia.

The effectiveness of non-pharmacological interventions in improving psychological outcomes for heart transplant recipients : a systematic review

Background Post-heart transplant psychological distress may both directly hinder physiological health as well as indirectly impact on clinical outcomes by increasing unhealthy behaviours, such as immunosuppression non-adherence. Reducing psychological distress for heart transplant recipients is therefore vitally important, in order to improve patients’ overall health and well-being but also clinical outcomes, such as morbidity and mortality. Evidence from other populations suggests that non-pharmacological interventions may be an effective strategy. Aim To appraise the efficacy of non-pharmacological interventions on psychological outcomes after heart transplant. Method A systematic review was conducted using the Joanna Briggs Institute methodology. Experimental and quasi-experimental studies that involved any non-pharmacological intervention for heart transplant recipients were included, provided that data on psychological outcomes were reported. Multiple electronic databases were searched for published and unpublished studies and reference lists of retrieved studies were scrutinized for further primary research. Data were extracted using a standardised data extraction tool. Included studies were assessed by two independent reviewers using standardised critical appraisal instruments. Results Three studies fulfilled the inclusion and exclusion criteria, which involved only 125 heart transplant recipients. Two studies reported on exercise programs. One study reported a web-based psychosocial intervention. While psychological outcomes significantly improved from baseline to follow-up for the recipients who received the interventions, between-group comparisons were not reported. The methodological quality of the studies was judged to be poor. Conclusions Further research is required, as we found there is insufficient evidence available to draw conclusions for or against the use of non-pharmacological interventions after heart transplant.

Networked masculinities and social networking sites : a call for the analysis of men and contemporary digital media

It is of course recognised that technology can be gendered and implicated in gender relations. However, it continues to be the case that men’s experiences with technology are underexplored and the situation is even more problematic where digital media is concerned. Over the past 30 years we have witnessed a dramatic rise in the pervasiveness of digital media across many parts of the world and as associated with wide ranging aspects of our lives. This rise has been fuelled over the last decade by the emergence of Web 2.0 and particularly Social Networking Sites (SNS). Given this context, I believe it is necessary for us to undertake more work to understand men’s engagements with digital media, the implications this might have for masculinities and the analysis of gender relations more generally. To begin to unpack this area, I engage theorizations of the properties of digital media networks and integrate this with the masculinity studies field. Using this framework, I suggest we need to consider the rise in what I call networked masculinities – those masculinities (co)produced and reproduced with digitally networked publics. Through this analysis I discuss themes related to digital mediators, relationships, play and leisure, work and commerce, and ethics. I conclude that as masculinities can be, and are being, complicated and given agency by advancing notions and practices of connectivity, mobility, classification and convergence, those engaged with masculinity studies and digital media have much to contribute.

Understanding the fabric of social interactions for ridesharing through mining social networking sites

The design of applications for dynamic ridesharing or carpooling is often formulated as a matching problem of connecting people with an aligned set of transport needs within a reasonable interval of time and space. This problem formulation relegates social connections to being secondary factors. Technology assisted ridesharing applications that put the matching problem first have revealed that they suffer from being unable to address the factor of social comfort, even after adding friend features or piggybacking on social networking sites. This research aims to understand the fabric of social interactions through which ridesharing happens. We take an online observation approach in order to understand the fabric of social interactions for ridesharing that is happening in highly subscribed online groups of local residents. This understanding will help researchers to identify design challenges and opportunities to support ridesharing in local communities. This paper contributes a fundamental understanding of how social interactions and social comfort precede rideshare requests in local communities.

Motivating domestic energy conservation through comparative feedback in mobile applications and social networking sites

The progress of technology has led to the increased adoption of energy monitors among household energy consumers. While the monitors available on the market deliver real-time energy usage feedback to the consumer, the form of this data is usually unengaging and mundane. Moreover, it fails to address consumers with different motivations and needs to save and compare energy. This master‟s thesis project presents a study that seeks to inform design guidelines for differently motivated energy consumers. The focus of the research is on comparative feedback supported by a community of energy consumers. In particular, the discussed comparative feedback types are explanatory comparison, temporal self-comparison, norm comparison, one-on-one comparison and ranking, whereby the last three support exploring the potential of socialising energy-related feedback in social networking sites, such as Facebook. These feedback types were integrated in EnergyWiz – a mobile application that enables users to compare with their past performance, neighbours, contacts from social networking sites and other EnergyWiz users. The application was developed through a theory-driven approach and evaluated in personal, semi-structured interviews which provided insights on how motivation-related comparative feedback should be designed. It was also employed in expert focus group discussions which resulted in defining opportunities and challenges before mobile, social energy monitors. The findings have unequivocally shown that users with different motivations to compare and to conserve energy have different preferences for comparative feedback types and design. It was established that one of the most influential factors determining design factors is the people users compare to. In addition, the research found that even simple communication strategies in Facebook, such as wall posts and groups can contribute to engagement with energy conservation practices. The concept of mobility of the application was evaluated as positive since it provides place and time-independent access to the energy consumption data.

Social engineering in social networking sites : phase-based and source-based models

Social networking sites (SNSs), with their large numbers of users and large information base, seem to be perfect breeding grounds for exploiting the vulnerabilities of people, the weakest link in security. Deceiving, persuading, or influencing people to provide information or to perform an action that will benefit the attacker is known as “social engineering.” While technology-based security has been addressed by research and may be well understood, social engineering is more challenging to understand and manage, especially in new environments such as SNSs, owing to some factors of SNSs that reduce the ability of users to detect the attack and increase the ability of attackers to launch it. This work will contribute to the knowledge of social engineering by presenting the first two conceptual models of social engineering attacks in SNSs. Phase-based and source-based models are presented, along with an intensive and comprehensive overview of different aspects of social engineering threats in SNSs.

Social engineering in social networking sites : affect-based model

While social engineering represents a real and ominous threat to many organizations, companies, governments, and individuals, social networking sites (SNSs), have been identified as among the most common means of social engineering attacks. Owing to factors that reduce the ability of users to detect social engineering tricks and increase the ability of attackers to launch them, SNSs seem to be perfect breeding ground for exploiting the vulnerabilities of people, and the weakest link in security. This work will contribute to the knowledge of social engineering by identifying different entities and subentities that affect social engineering based attacks in SNSs. Moreover, this paper includes an intensive and comprehensive overview of different aspects of social engineering threats in SNSs.

From single crystal surfaces to single atoms : investigating active sites in electrocatalysis

Electrocatalytic processes will undoubtedly be at the heart of energising future transportation and technology with the added importance of being able to create the necessary fuels required to do so in an environmentally friendly and cost effective manner. For this to be successful two almost mutually exclusive surface properties need to be reconciled, namely producing highly active/reactive surface sites that exhibit long term stability. This article reviews the various approaches which have been undertaken to study the elusive nature of these active sites on metal surfaces which are considered as adatoms or clusters of adatoms with low coordination number. This includes the pioneering studies at extended well defined stepped single crystal surfaces using cyclic voltammetry up to the highly sophisticated in situ electrochemical imaging techniques used to study chemically synthesised nanomaterials. By combining the information attained from single crystal surfaces, individual nanoparticles of defined size and shape, density functional theory calculations and new concepts such as mesoporous multimetallic thin films and single atom electrocatalysts new insights into the design and fabrication of materials with highly active but stable active sites can be achieved. The area of electrocatalysis is therefore not only a fascinating and exciting field in terms of realistic technological and economical benefits but also from the fundamental understanding that can be acquired by studying such an array of interesting materials.

Literacies on the Web : Co-Production of Literary Texts on Fan Fiction Sites

In this chapter the authors discuss and informal learning settings such as fan fiction sites and their relations to teaching and learning within formal learning settings. Young people today spend a lot of time with social media built on user generated content. These media are often characterized by participatory culture which offers a good environment for developing skills and identity work. In this chapter the authors problematize fan fiction sites as informal learning settings where the possibilities to learn are powerful and significant. They also discuss the learning processes connected to the development of literacies. Here the rhetoric principle of “imitatio” plays a vital part as well as the co-production of texts on the sites, strongly supported by the beta reader and the power of positive feedback. They also display that some fans, through the online publication of fan fiction, are able to develop their craft in a way which previously have been impossible.

Chronic activation of the low affinity site of β1-adrenoceptors stimulates haemodynamics but exacerbates pressure-overload cardiac remodelling

Background and Purpose The β1-adrenoceptor has at least two binding sites, high and low affinity sites (β1H and β1L, respectively), which mediate cardiostimulation. While β1H-adrenoceptor can be blocked by all clinically used β-blockers, β1L-adrenoceptor is relatively resistant to blockade. Thus, chronic β1L-adrenoceptor activation may mediate persistent cardiostimulation, despite the concurrent blockade of β1H-adrenoceptors. Hence, it is important to determine the potential significance of β1L-adrenoceptors in vivo, particularly in pathological situations. Experimental Approach C57Bl/6 male mice were used. Chronic (4 or 8 weeks) β1L-adrenoceptor activation was achieved by treatment, via osmotic mini pumps, with (-)-CGP12177 (10 mg·kg−1·day−1). Cardiac function was assessed by echocardiography and micromanometry. Key Results (-)-CGP12177 treatment of healthy mice increased heart rate and left ventricular (LV) contractility. (-)-CGP12177 treatment of mice subjected to transverse aorta constriction (TAC), during weeks 4–8 or 4–12 after TAC, led to a positive inotropic effect and exacerbated fibrogenic signalling while cardiac hypertrophy tended to be more severe. (-)-CGP12177 treatment of mice with TAC also exacerbated the myocardial expression of hypertrophic, fibrogenic and inflammatory genes compared to untreated TAC mice. Washout of (-)-CGP12177 revealed a more pronounced cardiac dysfunction after 12 weeks of TAC. Conclusions and Implications β1L-adrenoceptor activation provides functional support to the heart, in both normal and pathological (pressure overload) situations. Sustained β1L-adrenoceptor activation in the diseased heart exacerbates LV remodelling and therefore may promote disease progression from compensatory hypertrophy to heart failure.

Mapping, monitoring, and modelling of hazardous waste sites

Management of the industrial nations' hazardous waste is a current and exponentially increasing, global threatening situation. Improved environmental information must be obtained and managed concerning the current status, temporal dynamics and potential future status of these critical sites. To test the application of spatial environmental techniques to the problem of hazardous waste sites, as Superfund (CERCLA) test site was chosen in an industrial/urban valley experiencing severe TCE, PCE, and CTC ground water contamination. A paradigm is presented for investigating spatial/environmental tools available for the mapping, monitoring and modelling of the environment and its toxic contaminated plumes. This model incorporates a range of technical issues concerning the collection of data as augmented by remotely sensed tools, the format and storage of data utilizing geographic information systems, and the analysis and modelling of environment through the use of advance GIS analysis algorithms and geophysic models of hydrologic transport including statistical surface generation. This spatial based approach is evaluated against the current government/industry standards of operations. Advantages and lessons learned of the spatial approach are discussed.