Uniform large-area surface patterning achieved by metal dewetting for the top-down fabrication of GaN nanowire ensembles.

The dewetting of thin Pt films on different surfaces is investigated as a means to provide the patterning for the top-down fabrication of GaN nanowire ensembles. The transformation from a thin film to an ensemble of nanoislands upon annealing proceeds in good agreement with the void growth model. With increasing annealing duration, the size and shape uniformity of the nanoislands improves. This improvement speeds up for higher annealing temperature. After an optimum annealing duration, the size uniformity deteriorates due to the coalescence of neighboring islands. By changing the Pt film thickness, the nanoisland diameter and density can be quantitatively controlled in a way predicted by a simple thermodynamic model. We demonstrate the uniformity of the nanoisland ensembles for an area larger than 1 cm2. GaN nanowires are fabricated by a sequence of dry and wet etching steps, and these nanowires inherit the diameters and density of the Pt nanoisland ensemble used as a mask. Our study achieves advancements in size uniformity and range of obtainable diameters compared to previous works. This simple, economical, and scalable approach to the top-down fabrication of nanowires is useful for applications requiring large and uniform nanowire ensembles with controllable dimensions.

The economic burden of fragile x syndrome: healthcare resource utilization in the United States.

BACKGROUND: Fragile X syndrome (FXS) is the most common inherited form of intellectual disability with cognitive and behavioral impairments, and is associated with a lifetime of care-taking challenges. There is a paucity of data on the economic burden of FXS. OBJECTIVE: To analyze the direct costs associated with healthcare and medication utilization for patients with FXS by using commercial and Medicare/Medicaid administrative claims data. METHODS: All-cause direct healthcare and prescription drug utilization were analyzed from the Thomson Reuters Healthcare MarketScan Commercial, the Medicare Supplemental, and the MarketScan Medicaid databases between 2004 and 2009. Inclusion criteria were ≥1 diagnosis of FXS (International Classification of Diseases, Ninth Revision, 759.83) and ≥12 months of continuous enrollment in the current health plan. Emergency department, hospitalization, outpatient visit, nonspecified procedures, and prescription drug data were analyzed for a 12-month follow-up period. Because the number of Medicare patients was <50, commercial and Medicare databases were combined into a single cohort. Descriptive statistics were used to summarize the results. RESULTS: A total of 1505 patients were included in the study; of these, 784 patients had commercial/Medicare insurance and 721 patients had Medicaid. The mean age was 18 years. In all age-groups, the median all-cause healthcare cost per patient was significantly lower in the commercial/Medicare cohort (range, $2222-$2955) than in the Medicaid cohort (range, $4548-$9702). The annual median costs per patient for those who had any medical procedures were $1614 and $3064 for commercial or Medicare and for Medicaid, respectively. The annual median costs per patient for those with at least 1 hospitalization was $7740 in the commercial/Medicare cohort (9.4% of patients) and $4468 in the Medicaid cohort (12.5% of patients). CONCLUSION: This first descriptive US claims analysis supports the overall results from surveys on the economic burden related to FXS. The cost drivers in this population included medical procedures, hospitalizations in a subset of patients, and medications to a lesser extent. This information may be relevant to payers for benefit design and allocation of resources. A more targeted assessment of resource utilization is needed to estimate the value of interventions that reduce costs and improve the outcomes of patients with FXS.

CYP2C9 and CYP2C19 genetic polymorphisms: frequencies in the south Indian population.

The aim of the study was to establish the frequencies of CYP2C9*1, *2, *3 and CYP2C19*1, *2 and *3 in the south Indian population and to compare them with the inter-racial distribution of the CYP2C9 and CYP2C19 genetic polymorphisms. Genotyping analyses of CYP2C9 and CYP2C19 were conducted in unrelated, healthy volunteers from the three south Indian states of Andhra Pradesh, Karnataka and Kerala, by the polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP). The allele frequencies of the populations of these three states were then pooled with our previous genotyping data of Tamilians (also in south India), to arrive at the distribution of CYP2C9 and CYP2C19 alleles in the south Indian population. Frequencies of CYP2C9 and CYP2C19 alleles and genotypes among various populations were compared using the two-tailed Fisher's exact test. The frequencies of CYP2C9*1, *2 and *3 in the south Indian population were 0.88 (95% CI 0.85-0.91), 0.04 (95% CI 0.02-0.06) and 0.08 (95% CI 0.06-0.11), respectively. The frequencies of CYP2C9 genotypes *1/*1, *1/*2, *1/*3, *2/*2, *2/*3 and *3/*3 were 0.78 (95% CI 0.74-0.82), 0.05 (95% CI 0.03-0.07), 0.15 (95% CI 0.12-0.18), 0.01 (95% CI 0.0-0.02), 0.01 (95% CI 0.0-0.02) and 0.0, respectively. CYP2C19*1, *2 and *3 frequencies were 0.64 (95% CI 0.60-0.68), 0.35 (95% CI 0.31-0.39) and 0.01 (95% CI 0.0-0.03), respectively. As a result of a significant heterogeneity, the data on CYP2C19 genotype frequencies were not pooled. The frequency of CYP2C9*2 mutant alleles in south Indians was higher than in Chinese and Caucasians, while CYP2C9*3 was similar to Caucasians. CYP2C19*2 was higher than in other major populations reported so far. The relatively high CYP2C19 poor-metabolizer genotype frequency of 12.6% indicates that over 28 million south Indians are poor metabolizers of CYP2C19 substrates.