TOIB Study. Are topical or oral ibuprofen equally effective for the treatment of chronic knee pain presenting in primary care: a randomised controlled trial with patient preference study. [ISRCTN79353052]

BACKGROUND: Many older people have chronic knee pain. Both topical and oral non- steroidal anti-inflammatory drugs (NSAIDs) are commonly used to treat this. Oral NSAIDS are effective, at least in the short term, but can have severe adverse effects. Topical NSAIDs also appear to be effective, at least in the short term. One might expect topical NSAIDs both to be less effective and to have fewer adverse effects than oral NSAIDs. If topical NSAIDs have fewer adverse effects this may outweigh both the reduction in effectiveness and the higher cost of topical compared to oral treatment. Patient preferences may influence the comparative effectiveness of drugs delivered via different routes. METHODS: TOIB is a randomised trial comparing topical and oral ibuprofen, with a parallel patient preference study. We are recruiting people aged 50 or over with chronic knee pain, from 27 MRC General Practice Research Framework practices across the UK. We are seeking to recruit 283 participants to the RCT and 379 to the PPS. Participants will be followed up for up to two years (with the majority reaching one year). Outcomes will be assessed by postal questionnaire, nurse examination, laboratory tests and medical record searches at one and two years or the end of the study. DISCUSSION: This study will provide new evidence on the overall costs and benefits of treating chronic knee pain with either oral or topical ibuprofen. The use of a patient preference design is unusual, but will allow us to explore how preference influences response to a medication. In addition, it will provide more information on adverse events. This study will provide evidence to inform primary care practitioners, and possibly influence practice

Epidemic of hypertension in Ghana: a systematic review

Background Hypertension is a major risk factor for many cardiovascular diseases in developing countries. A comprehensive review of the prevalence of hypertension provides crucial information for the evaluation and implementation of appropriate programmes. Methods The PubMed and Google Scholar databases were searched for published articles on the population-based prevalence of adult hypertension in Ghana between 1970 and August 2009, supplemented by a manual search of retrieved references. Fifteen unique population-based articles in non-pregnant humans were obtained. In addition, two relevant unpublished graduate student theses from one university department were identified after a search of its 1996-2008 theses. Results The age and sex composition of study populations, sampling strategy, measurement of blood pressure, definition of hypertension varied between studies. The prevalence of hypertension (BP ≥ 140/90 mmHg ± antihypertensive treatment) ranged from 19% to 48% between studies. Sex differences were generally minimal whereas urban populations tended to have higher prevalence than rural population in studies with mixed population types. Factors independently associated with hypertension included older age group, over-nutrition and alcohol consumption. Whereas there was a trend towards improved awareness, treatment and control between 1972 and 2005, less than one-third of hypertensive subjects were aware they had hypertension and less than one-tenth had their blood pressures controlled in most studies. Conclusion Hypertension is clearly an important public health problem in Ghana, even in the poorest rural communities. Emerging opportunities such as the national health insurance scheme, a new health policy emphasising health promotion and healthier lifestyles and effective treatment should help prevent and control hypertension

Electromechanical response of group-IV monochalcogenide monolayers

The group-IV monochalcogenides, GeS, GeSe, SnS and SnSe are known to produce large piezoelectric responses and have great flexibility due to sharing a similar structure to black phosphorus. In this work, we show that the group-IV monochalcogenide monolayers are able to achieve similar strains upon charge injection due to their puckered orthorhombic structure. Using first-principles density functional theory calculations, we demonstrate that upon electron and hole injection, the monolayers expand and contract, respectively. GeSe experienced the greatest response to electron injection, with its lattice expanding by 10.6% (0.93 Å). Conversely, in response to hole injection, SnS contracted the most (by −12.7% or −1.13 Å). The strains obtained allow the assessment of the actuation stress and volumetric work density of the monolayers which indicates their performance as being suitable for actuation materials. Of the four investigated monolayers, SnS has the greatest actuation stress (−2.5 GPa) and volumetric work density (86.6 J cm−3). The mechanism behind the electromechanical strains produced were examined through analysis of the structural deformations and charge density distribution within the monolayers. The introduction of charge to the system also affects the electronic properties (band gaps, density of states) of the monolayers. Significantly, the piezoelectric response of the four monolayers exceeds those of phosphorene and MoS2, with SnSe having the largest value of 0.93 C m−2 making it ideal for piezoelectric based actuators. These results demonstrate how the group-IV monochalcogenides can be potential candidate materials for various micro/nano electromechanical systems in actuator devices

Ferroelectric van der Waals heterostructures of CuInP2S6 for non-volatile memory device applications

Two-dimensional (2D) ferroelectric materials are providing promising platforms for creating future nano- and opto-electronics. Here we propose new hybrid van der Waals heterostructures, in which the 2D ferroelectric material CuInP2S6 (CIPS) is layered on a 2D semiconductor for near-infrared (NIR) memory device applications. Using density functional theory, we show that the band gap of the hybrid bilayers formed with CIPS can be tuned and that the optical and electronic properties can be successfully modulated via ferroelectric switching. Of the 3712 heterostructures considered, we identified 19 structures that have a type II band alignment and commensurate lattice matches. Of this set, both the CuInP2S6/PbSe and CuInP2S6/Ge2H2 heterostructures possess absorption peaks in the NIR region that change position and intensity with switching polarisation, making them suitable for NIR memory devices. The CuInP2S6/ISSb, CuInP2S6/ISbSe, CuInP2S6/ClSbSe and CuInP2S6/ZnI2 heterostructures had band gaps which can be switched from direct to indirect with changing the polarisation of CIPS making them suitable for optoelectronics and sensors. The heterostructures formed with CIPS are exciting candidates for stable ferroelectric devices, opening a pathway for tuning the band alignment of van der Waal heterostructures and the creation of modern memory applications that use less energy

Adsorption of toxic gases on silicene/Ag(111)

Silicene/Ag(111) demonstrates many unique properties, and shows potential in sensing and storage applications of toxic gases such as SO2, NO2 and H2S.</p

Tuning the work function of the silicene/4 × 4 Ag(111) surface

The work function of the silicene/silver surface can be tuned via functionalisation, according to density-functional theory calculations.</p