Clinical and economic outcomes of a multidisciplinary team approach in a lower extremity amputation prevention programme for diabetic foot ulcer care in an Asian population: A case-control study.

Present guidelines recommend a multidisciplinary team (MDT) approach to diabetic foot ulcer (DFU) care, but relevant data from Asia are lacking. We aim to evaluate the clinical and economic outcomes of an MDT approach in a lower extremity amputation prevention programme (LEAPP) for DFU care in an Asian population. We performed a case-control study of 84 patients with DFU between January 2017 and October 2017 (retrospective control) vs 117 patients with DFU between December 2017 and July 2018 (prospective LEAPP cohort). Comparing the clinical outcomes between the retrospective cohort and the LEAPP cohort, there was a significant decrease in mean time from referral to index clinic visit (38.6 vs 9.5 days, P < .001), increase in outpatient podiatry follow-up (33% vs 76%, P < .001), decrease in 1-year minor amputation rate (14% vs 3%, P = .007), and decrease in 1-year major amputation rate (9% vs 3%, P = .05). Simulation of cost avoidance demonstrated an annualised cost avoidance of USD $1.86m (SGD $2.5m) for patients within the LEAPP cohort. In conclusion, similar to the data from Western societies, an MDT approach in an Asian population, via a LEAPP for patients with DFU, demonstrated a significant reduction in minor and major amputation rates, with annualised cost avoidance of USD $1.86m.

Metabolic effects of brown fat in transitioning from hyperthyroidism to euthyroidism.

OBJECTIVE: Brown adipose tissue (BAT) controls metabolic rate through thermogenesis. As its regulatory factors during the transition from hyperthyroidism to euthyroidism are not well established, our study investigated the relationships between supraclavicular brown adipose tissue (sBAT) activity and physiological/metabolic changes with changes in thyroid status. DESIGN: Participants with newly diagnosed Graves' disease were recruited. A thionamide antithyroid drug (ATD) such as carbimazole (CMZ) or thiamazole (TMZ) was prescribed in every case. All underwent energy expenditure (EE) measurement and supraclavicular infrared thermography (IRT) within a chamber calorimeter, as well as 18F-fluorodeoxyglucose (18F-FDG) positron-emission tomography/magnetic resonance (PET/MR) imaging scanning, with clinical and biochemical parameters measured during hyperthyroidism and repeated in early euthyroidism. PET sBAT mean/maximum standardized uptake value (SUV mean/max), MR supraclavicular fat fraction (sFF) and mean temperature (Tscv) quantified sBAT activity. RESULTS: Twenty-one (16 female/5 male) participants aged 39.5 ± 2.5 years completed the study. The average duration to attain euthyroidism was 28.6 ± 2.3 weeks. Eight participants were BAT-positive while 13 were BAT-negative. sFF increased with euthyroidism (72.3 ± 1.4% to 76.8 ± 1.4%; P < 0.01), but no changes were observed in PET SUV mean and Tscv. Significant changes in serum-free triiodothyronine (FT3) levels were related to BAT status (interaction P value = 0.04). FT3 concentration at hyperthyroid state was positively associated with sBAT PET SUV mean (r = 0.58, P = 0.01) and resting metabolic rate (RMR) (P < 0.01). CONCLUSION: Hyperthyroidism does not consistently lead to a detectable increase in BAT activity. FT3 reduction during the transition to euthyroidism correlated with BAT activity.

Step flow versus mosaic film growth in hexagonal boron nitride.

Many emerging applications of hexagonal boron nitride (h-BN) in graphene-based nanoelectronics require high-quality monolayers as the ultrathin dielectric. Here, the nucleation and growth of h-BN monolayer on Ru(0001) surface are investigated using scanning tunneling microscopy with a view toward understanding the process of defect formation on a strongly interacted interface. In contrast to homoelemental bonding in graphene, the heteroelemental nature of h-BN gives rise to growth fronts with elemental polarity. This can have consequences in the different stages of film growth, from the nucleation of h-BN magic clusters and their sintering to form compact triangular islands to the growth of patchwork mosaic monolayer with a high density of misfit boundaries. The parallel alignment of triangular islands on the same terrace produces translational fault lines when growth fronts merge, while antiparallel alignment of islands on adjacent terraces produces non-bonded fault lines between domains terminated by like atoms. With these insights into the generation of void defects and fault lines at grain boundaries, we demonstrate a strategy to obtain high-quality h-BN monolayer film based on step flow growth.

Strain dependence of the heat transport properties of graphene nanoribbons.

Using a combination of accurate density-functional theory and a nonequilibrium Green's function method, we calculate the ballistic thermal conductance characteristics of tensile-strained armchair (AGNR) and zigzag (ZGNR) edge graphene nanoribbons, with widths between 3 and 50 Å. The optimized lateral lattice constants for AGNRs of different widths display a three-family behavior when the ribbons are grouped according to N modulo 3, where N represents the number of carbon atoms across the width of the ribbon. Two lowest-frequency out-of-plane acoustic modes play a decisive role in increasing the thermal conductance of AGNR-N at low temperatures. At high temperatures the effect of tensile strain is to reduce the thermal conductance of AGNR-N and ZGNR-N. These results could be explained by the changes in force constants in the in-plane and out-of-plane directions with the application of strain. This fundamental atomistic understanding of the heat transport in graphene nanoribbons paves a way to effect changes in their thermal properties via strain at various temperatures.

Using the graphene Moiré pattern for the trapping of C60 and homoepitaxy of graphene.

The graphene Moiré superstructure offers a complex landscape of humps and valleys to molecules adsorbing and diffusing on it. Using C(60) molecules as the classic hard sphere analogue, we examine its assembly and layered growth on this corrugated landscape. At the monolayer level, the cohesive interactions of C(60) molecules adsorbing on the Moiré lattice freeze the molecular rotation of C(60) trapped in the valley sites, resulting in molecular alignment of all similarly trapped C(60) molecules at room temperature. The hierarchy of adsorption potential well on the Moiré lattice causes diffusion-limited dendritic growth of C(60) films, as opposed to isotropic growth observed on a smooth surface like graphite. Due to the strong binding energy of the C(60) film, part of the dentritic C(60) films polymerize at 850 K and act as solid carbon sources for graphene homoepitaxy. Our findings point to the possibility of using periodically corrugated graphene in molecular spintronics due to its ability to trap and align organic molecules at room temperature.

Transforming C60 molecules into graphene quantum dots.

The fragmentation of fullerenes using ions, surface collisions or thermal effects is a complex process that typically leads to the formation of small carbon clusters of variable size. Here, we show that geometrically well-defined graphene quantum dots can be synthesized on a ruthenium surface using C(60) molecules as a precursor. Scanning tunnelling microscopy imaging, supported by density functional theory calculations, suggests that the structures are formed through the ruthenium-catalysed cage-opening of C(60). In this process, the strong C(60)-Ru interaction induces the formation of surface vacancies in the Ru single crystal and a subsequent embedding of C(60) molecules in the surface. The fragmentation of the embedded molecules at elevated temperatures then produces carbon clusters that undergo diffusion and aggregation to form graphene quantum dots. The equilibrium shape of the graphene can be tailored by optimizing the annealing temperature and the density of the carbon clusters.