Some mechanics challenges and solutions in flexible electronics

Flexible electronics is an emerging field with potential applications such as large area flexible displays, thin film solar panels, and smart prosthesis, to name a few. Promising future aside, there are challenges associated with flexible electronics including high deformability requirements, needs for new manufacturing techniques and high performance permeation barriers. This thesis aims to explore possible solutions to address these challenges. First, a thin stiff film patterned with circular holes is proposed as a deformable platform to be used in flexible electronics in either component and circuit level. Second, we explore possible pathways to improve the quality of transfer printing, a nanofabrication technique that can potentially enable roll-to-roll printing of flexible devices. Third, we investigate the failure mechanism of multilayer permeation barriers for flexible electronics and offer an improved design to achieve better mechanical reliability

Atrial fibrillation genetic risk differentiates cardioembolic stroke from other stroke subtypes

AbstractObjectiveWe sought to assess whether genetic risk factors for atrial fibrillation can explain cardioembolic stroke risk.MethodsWe evaluated genetic correlations between a prior genetic study of AF and AF in the presence of cardioembolic stroke using genome-wide genotypes from the Stroke Genetics Network (N = 3,190 AF cases, 3,000 cardioembolic stroke cases, and 28,026 referents). We tested whether a previously-validated AF polygenic risk score (PRS) associated with cardioembolic and other stroke subtypes after accounting for AF clinical risk factors.ResultsWe observed strong correlation between previously reported genetic risk for AF, AF in the presence of stroke, and cardioembolic stroke (Pearson’s r=0.77 and 0.76, respectively, across SNPs with p &lt; 4.4 × 10−4 in the prior AF meta-analysis). An AF PRS, adjusted for clinical AF risk factors, was associated with cardioembolic stroke (odds ratio (OR) per standard deviation (sd) = 1.40, p = 1.45×10−48), explaining ∼20% of the heritable component of cardioembolic stroke risk. The AF PRS was also associated with stroke of undetermined cause (OR per sd = 1.07, p = 0.004), but no other primary stroke subtypes (all p &gt; 0.1).ConclusionsGenetic risk for AF is associated with cardioembolic stroke, independent of clinical risk factors. Studies are warranted to determine whether AF genetic risk can serve as a biomarker for strokes caused by AF.</jats:sec

ORIGINAL ARTICLE Adenosquamous Versus Adenocarcinoma of the Pancreas: A Population-Based Outcomes Analysis

# The Author(s) 2010. This article is published with open access at Springerlink.com Background Pancreatic adenosquamous carcinoma has historically been characterized as having a more aggressive clinical course than ductal adenocarcinoma. The natural history of this disease, however, is essentially unknown. Methods We evaluated the clinical characteristics of all patients with pancreatic adenosquamous carcinoma recorded in the California Cancer Registry 2000–2007 and compared them to those of patients with ductal adenocarcinoma. Results Ninety-five patients with pancreatic adenosquamous carcinoma and 14,746 patients with ductal adenocarcinoma were identified. Demographics were similar between subtypes (p&gt;0.05). Disease stage at presentation was also similar; over 50 % of each diagnostic group presented with metastatic disease (p=0.62). Surgical resection was more common among patients with locoregional adenosquamous carcinoma than adenocarcinoma (p=0.0004), but rates of adjuvant therapy administration were similar (p&gt;0.05). The cohorts ’ median overall survival durations were similar in a Cox proportional hazards model (p=0.45); overall survival was also similar when only patients with resected disease were considered (p= 0.65). Early stage, resection and receipt of radiation or chemotherapy were favorable independent prognostic factors among patients with adenosquamous carcinoma. The median overall survival duration of patients with resected adenosquamous carcinoma was 12 months (95 % CI, 8–52)

Discovery and fine-mapping of height loci via high-density imputation of GWASs in individuals of African ancestry

Although many loci have been associated with height in European ancestry populations, very few have been identified in African ancestry individuals. Furthermore, many of the known loci have yet to be generalized to and fine-mapped within a large-scale African ancestry sample. We performed sex-combined and sex-stratified meta-analyses in up to 52,764 individuals with height and genome-wide genotyping data from the African Ancestry Anthropometry Genetics Consortium (AAAGC). We additionally combined our African ancestry meta-analysis results with published European genome-wide association study (GWAS) data. In the African ancestry analyses, we identified three novel loci (SLC4A3, NCOA2, ECD/FAM149B1) in sex-combined results and two loci (CRB1, KLF6) in women only. In the African plus European sex-combined GWAS, we identified an additional three novel loci (RCCD1, G6PC3, CEP95) which were equally driven by AAAGC and European results. Among 39 genome-wide significant signals at known loci, conditioning index SNPs from European studies identified 20 secondary signals. Two of the 20 new secondary signals and none of the 8 novel loci had minor allele frequencies (MAF) \u3c 5%. Of 802 known European height signals, 643 displayed directionally consistent associations with height, of which 205 were nominally significant (p \u3c 0.05) in the African ancestry sex-combined sample. Furthermore, 148 of 241 loci contained ≤20 variants in the credible sets that jointly account for 99% of the posterior probability of driving the associations. In summary, trans-ethnic meta-analyses revealed novel signals and further improved fine-mapping of putative causal variants in loci shared between African and European ancestry populations

Atrial fibrillation genetic risk differentiates cardioembolic stroke from other stroke subtypes

Objective: We sought to assess whether genetic risk factors for atrial fibrillation (AF) can explain cardioembolic stroke risk. Methods: We evaluated genetic correlations between a previous genetic study of AF and AF in the presence of cardioembolic stroke using genome-wide genotypes from the Stroke Genetics Network (N = 3,190 AF cases, 3,000 cardioembolic stroke cases, and 28,026 referents). We tested whether a previously validated AF polygenic risk score (PRS) associated with cardioembolic and other stroke subtypes after accounting for AF clinical risk factors. Results: We observed a strong correlation between previously reported genetic risk for AF, AF in the presence of stroke, and cardioembolic stroke (Pearson r = 0.77 and 0.76, respectively, across SNPs with p 0.1). Conclusions: Genetic risk of AF is associated with cardioembolic stroke, independent of clinical risk factors. Studies are warranted to determine whether AF genetic risk can serve as a biomarker for strokes caused by AF.status: publishe