Fabrication of metal-nanoparticle-modified semiconducting copper--and silver--TCNQ materials as substrates for the reduction of chromium (VI) using thiosulfate ions at ambient temperature

The formation of readily recoverable and reusable organic semiconducting Cu- and AgTCNQ (TCNQ=7,7,8,8-tetracyanoquinodimethane) microstructures decorated with Pt and Pd metallic nanoparticles is described for the effective reduction of CrVI ions in aqueous solution at room temperature using both formic acid and an environmentally friendly thiosulfate reductant. The M-TCNQ (M=metal) materials were formed by electrocrystallisation onto a glassy carbon surface followed by galvanic replacement in the presence of H2PtCl6 or PdCl2 to form the composite material. It was found that loading of the surface with nanoparticles could easily be controlled by changing the metal salt concentration. Significantly, the M-TCNQ substrates facilitated the formation of well-isolated metal nanoparticles on their surfaces under appropriate galvanic replacement conditions. The semiconductor–metal nanoparticle combination was also found to be critical to the catalyst performance, wherein the best-performing material was CuTCNQ modified by well-isolated Pt nanoparticles with both formic acid and thiosulfate ions as the reductant.

Primary stability of two uncemented acetabular components of different geometry : hemispherical or peripherally enhanced?

Objective This study compared the primary stability of two commercially available acetabular components from the same manufacturer, which differ only in geometry; a hemispherical and a peripherally enhanced design (peripheral self-locking (PSL)). The objective was to determine whether altered geometry resulted in better primary stability. Methods Acetabular components were seated with 0.8 mm to 2 mm interference fits in reamed polyethylene bone substrate of two different densities (0.22 g/cm3 and 0.45 g/cm3). The primary stability of each component design was investigated by measuring the peak failure load during uniaxial pull-out and tangential lever-out tests. Results There was no statistically significant difference in seating force (p = 0.104) or primary stability (pull-out p = 0.171, lever-out p = 0.087) of the two components in the low-density substrate. Similarly, in the high-density substrate, there was no statistically significant difference in the peak pull-out force (p = 0.154) or lever-out moment (p = 0.574) between the designs. However, the PSL component required a significantly higher seating force thanthe hemispherical cup in the high-density bone analogue (p = 0.006). Conclusions Higher seating forces associated with the PSL design may result in inadequate seating and increased risk of component malpositioning or acetabular fracture in the intra-operative setting in high-density bone stock. Our results, if translated clinically, suggest that a purely hemispherical geometry may have an advantage over a peripherally enhanced geometry in high density bone stock.

Care and preventative maintenance of surgical instrumentation : the scrub nurse's responsibility

The cost of surgical instrumentation is a major investment for any operating theatre. Repair or premature replacement of instruments is an additional financial burden. Although instrument care, handling, cleaning and sterilisation are usually components of orientation programs for instrument processing personnel, it should also be included in the scrub nurse orientation program. A thorough knowledge of the historical development of instruments; instrument classification and purpose; and careful use and handling will equip the scrub nurse in fulfilling a vital role in preventative maintenance of surgical instrumentation

Effectiveness of an acellular synthetic matrix in the treatment of hard-to-heal leg ulcers

Hard-to-heal leg ulcers are a major cause of morbidity in the elderly population. Despite improvements in wound care, some wounds will not heal and they present a significant challenge for patients and health care providers. A multi-centre cohort study was conducted to evaluate the effectiveness and safety of a synthetic, extracellular matrix protein as an adjunct to standard care in the treatment of hard-to-heal venous or mixed leg ulcers. Primary effectiveness criteria were (i) reduction in wound size evaluated by percentage change in wound area and (ii) healing assessed by number of patients healed by end of the 12 week study. Pain reduction was assessed as a secondary effectiveness criteria using VAS. A total of 45 patients completed the study and no difference was observed between cohorts for treatment frequency. Healing was achieved in 35·6% and wound size decreased in 93·3% of patients. Median wound area percentage reduction was 70·8%. Over 50% of patients reported pain on first visit and 87·0% of these reported no pain at the end of the study. Median time to first reporting of no pain was 14 days after treatment initiation. The authors consider the extracellular synthetic matrix protein an effective and safe adjunct to standard care in the treatment of hard-to-heal leg ulcers.

International survey of rigid contact lens fitting

Purpose To determine the extent of rigid contact lens fitting worldwide and to characterize the associated demographics and fitting patterns. Methods Survey forms were sent to contact lens fitters in up to 40 countries between January and March every year for five consecutive years (2007 to 2011). Practitioners were asked to record data relating to the first 10 contact lens fits or refits performed after receiving the survey form. Survey data collected between 1996 and 2011 were also analyzed to assess rigid lens fitting trends in seven nations during this period. Results Data were obtained for 12,230 rigid and 100,670 soft lens fits between 2007 and 2011. Overall, rigid lenses represented 10.8% of all contact lens fits, ranging from 0.2% in Lithuania to 37% in Malaysia. Compared with soft lens fits, rigid lens fits can be characterized as follows: older age (rigid, 37.3 ± 15.0 years; soft, 29.8 ± 12.4 years); fewer spherical and toric fits; more bifocal/multifocal fits; less frequent replacement (rigid, 7%; soft, 85%); and less part-time wear (rigid, 4%; soft, 10%). High-Dk (contact lens oxygen permeability) (36%) and mid-Dk (42%) materials are predominantly used for rigid lens fitting. Orthokeratology represents 11.5% of rigid contact lens fits. There has been a steady decline in rigid lens fitting between 1996 and 2011. Conclusions Rigid contact lens prescribing is in decline but still represents approximately 10% of all contact lenses fitted worldwide. It is likely that rigid lenses will remain as a viable, albeit increasingly specialized, form of vision correction.

An early assessment of silicone hydrogel safety : pearls and pitfalls, and current status

The contact lens industry has evolved and now provides many choices, including continuous wear, overnight orthokeratology, frequent-replacement lenses, daily-disposable lenses, and many alternatives in systems of care and maintenance. Epidemiologic studies to date have shown that how a lens is worn, particularly if worn overnight, can increase the risk of microbial keratitis. However, the risk of silicone hydrogel contact lenses worn on a continuous-wear basis has been evaluated only recently. This article summarizes the recent research data on extended-wear silicone hydrogel lenses and discusses the challenges of early evaluations of silicone hydrogel lens safety. Finally, the relevance of this information is discussed to practitioners and contact lens wearers making choices about the risks and benefits of different products and how they are used.

The changing face of contact lens wearers over 25 years

A combination of factors has dictated patterns of prescribing to contact lens wearers in different age groups over time, such as the evolution of manufacturing technology in bringing better lens designs and replacement frequency options; the aging population demographic; and the knowledge and attitudes of practitioners. Here we explore evolving lens fitting practices at the opposite poles of the age spectrum—children and presbyopes.

Globalisation of CL prescribing : the UK perspective

Globalisation is a concept that templates onto many aspects of the commercial world, and the contact lens field is no exception. The major international companies have worldwide distribution networks and supply lenses of the same product names and replacement frequencies to all nations, with a few minor adjustments for marketing and regulatory reasons. Small and mediumsized companies, often producing more specialist lenses, are also active in markets across the world.

Contact lens prescribing : USA vs the world

Along with other facets of commericialization, the contact lens market has become globalized during the past 30 years. The major international companies have worldwide distribution networks and supply lenses of the same product names and replacement frequencies to all nations, with a few minor adjustments for marketing and regulatory reasons. Small and medium-sized companies, often producing more specialized lenses, are also active in markets across the world.

Development of an integrated GIS and land use planning course : impacts of hybrid instructional methods

This study reports an action research undertaken at Queensland University of Technology. It evaluates the effectiveness of the integration of GIS within the substantive domains of an existing land use planning course in 2011. Using student performance, learning experience survey, and questionnaire survey data, it also evaluates the impacts of incorporating hybrid instructional methods (e.g., in-class and online instructional videos) in 2012 and 2013. Results show that: students (re)iterated the importance of GIS in the course justifying the integration; the hybrid methods significantly increased student performance; and unlike replacement, the videos are more suitable as a complement to in-class activity.

Development of Contact Lenses from a Biomaterial Point of View – Materials, Manufacture, and Clinical Application

Rigid lenses, which were originally made from glass (between 1888 and 1940) and later from polymethyl methacrylate or silicone acrylate materials, are uncomfortable to wear and are now seldom fitted to new patients. Contact lenses became a popular mode of ophthalmic refractive error correction following the discovery of the first hydrogel material – hydroxyethyl methacrylate – by Czech chemist Otto Wichterle in 1960. To satisfy the requirements for ocular biocompatibility, contact lenses must be transparent and optically stable (for clear vision), have a low elastic modulus (for good comfort), have a hydrophilic surface (for good wettability), and be permeable to certain metabolites, especially oxygen, to allow for normal corneal metabolism and respiration during lens wear. A major breakthrough in respect of the last of these requirements was the development of silicone hydrogel soft lenses in 1999 and techniques for making the surface hydrophilic. The vast majority of contact lenses distributed worldwide are mass-produced using cast molding, although spin casting is also used. These advanced mass-production techniques have facilitated the frequent disposal of contact lenses, leading to improvements in ocular health and fewer complications. More than one-third of all soft contact lenses sold today are designed to be discarded daily (i.e., ‘daily disposable’ lenses).

Introducing dynamics : a new approach to "new media" [Editorial]

The term ‘‘new media’’ has been in play for decades now, and one might be forgiven for wondering how much longer digital forms and platforms can really be called ‘‘new,’’ or even what the scholarship of new media contributes to knowledge. Is it possible to say new things about new media? We think so. This Companion not only demonstrates the variety, salience, and importance of new media studies but also proposes a distinctive approach to the topic : an approach we call ‘‘new media dynamics.’’ In this view, what’s interesting about ‘‘new media’’ is not novelty as such but dynamism. Capitalism, technology, social networks, and media all evolve and change, sometimes to our delight, sometimes our dismay. This incessant process of disruption, renewal, and eventual (if often partial) replacement is now one of humanity’s central experiences. This cutting-edge collection brings together a stellar array of the world’s top researchers, cultural entrepreneurs, and emerging scholars to give the dynamics of new media their first full-length, multidisciplinary, historical, and critical treatment. Across 34 chapters, an international line-up of the very best authors reflects on the historical, technical, cultural, and political changes that underlie the emergence of new media, as existing patterns and assumptions are challenged by the forces of ‘‘creative destruction’’ and innovation, both economic and cultural. At the same time they show that familiar themes and problems carry through from ‘‘old’’media – questions of identity, sexuality, politics, relationships, and meaning.

Mesenchymal stromal cells and the repair of cartilage tissue

Articular cartilage has a limited intrinsic repair capacity, and thus defects are more likely to further degrade rather than undergo spontaneous self-repair. Whilst a number of surgical techniques have been developed to repair cartilage defects, their efficacy is generally poor and total joint replacement remains the gold standard, albeit last resort, treatment option. Cell-based therapies hold the greatest promise, as they appear uniquely capable of generating de novo cartilage tissue. Two approved therapies (ACI and MACI) are based on the premise that the transplantation of ex vivo expanded autologous chondrocyte populations, harvested from a non-load bearing region of the same joint, could be utilized to effectively regenerate cartilage tissue in the primary defect site. These therapeutic strategies are partially limited by our inability to harvest and expand adequate numbers of autologous chondrocytes that retain the appropriate phenotype. By contrast, the harvest and expansion of large numbers of mesenchymal stem/stromal cells (MSC) derived from tissues such as bone marrow and adipose is comparatively straightforward and has become routine in laboratories worldwide. Additionally, our understanding of the biochemical and biophysical signals required to drive the chondrogenic differentiation of MSC is rapidly increasing. It is conceivable that in the near future MSC expansion and differentiation technologies will offer a means to generate sufficient cell numbers, of an appropriate phenotype, for use in cartilage defect repair. In this chapter we review the relative potential of MSC and their likely contribution to cartilage regeneration.

Kamouflage : loss-resistant password management

We introduce Kamouflage: a new architecture for building theft-resistant password managers. An attacker who steals a laptop or cell phone with a Kamouflage-based password manager is forced to carry out a considerable amount of online work before obtaining any user credentials. We implemented our proposal as a replacement for the built-in Firefox password manager, and provide performance measurements and the results from experiments with large real-world password sets to evaluate the feasibility and effectiveness of our approach. Kamouflage is well suited to become a standard architecture for password managers on mobile devices.