Heat-induced bubble expansion as a route to increase the porosity of foam-templated bio-based macroporous polymers

Macroporous polymers were prepared by mechanically frothing a bio-based epoxy resin and hardener mixture to first create air-in-resin liquid foams, followed by curing of these liquid foams. It was found that heating the air-in-resin liquid foams prior to their gelation decreased the viscosity of the resin mixture and increased the pressure of the air bubbles, leading to an isotropic expansion of the air bubbles. This resulted in an increase in the porosity of the resulting foam-templated macroporous polymers from 71% to 85%. Correspondingly, the compressive moduli (E) and strengths (σ) of the foam-templated macroporous polymers decreased from 231 MPa and 5.9 MPa, respectively, to 58 MPa and 1.9 MPa, respectively. This decrease is attributed to an increase in the porosity and pore throat frequency of the foam-templated macroporous polymers when heat was applied to the liquid foams. The deformation of the pores based on in situ SEM micro-compression test of the fabricated foam-templated macroporous polymers is also discussed

Single nucleotide polymorphisms of complement component 5 and periodontitis

BACKGROUND AND OBJECTIVE: Polymorphisms of host defence genes might increase one's risks for periodontitis. This study investigated whether tagging single nucleotide polymorphisms (SNPs) of the gene encoding complement component 5 (C5) are associated with periodontitis in a Hong Kong Chinese population. MATERIAL AND METHODS: Eleven tagging SNPs of 229 patients with at least moderate periodontitis and 207 control subjects without periodontitis were genotyped using an i-plexGOLD MassARRAY mass-spectrometry system. RESULTS: Genotype AG of SNP rs17611 was more prevalent in the group of periodontitis patients than in the controls (54.6% vs. 41.7%, p = 0.007). The haplotype CGCA of the haplotype block consisting of rs1035029, rs17611, rs25681 and rs992670 was significantly associated with periodontitis in a dominant model (p = 0.001). The SNP rs17611 showed high linkage disequilibrium with rs1035029, rs25681 and rs992670. Smoking was also significantly associated with periodontitis (p = 0.006). CONCLUSION: The tagging SNP rs17611 of the C5 gene and smoking may be associated with periodontitis among the Hong Kong Chinese population.postprin

Genetic polymorphisms and periodontitis in Hong Kong Chinese

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Comparison of fatty-acid-binding protein 4 and adiponectin levels in infrapatellar fat pad and subcutaneous adipose tissue, synovial fluid and plasma in subjects with knee osteoarthritis

Conference Theme: Defying the Aging Spine: Our Mission ContinuesConcurrent Free Papers 2 - Basic Science/General Orthopaedics: no. 2.8Introduction: It was recently reported that inflammation is involved in the pathogenesis of osteoarthritis (OA). Fattyacid-binding protein 4 (FABP4) and adiponectin are both adipocyte-derived cytokines closely related with inflammation pathways. The FABP4 exhibits a pro-inflammatory property while adiponectin shows anti-inflammatory effect. The study aimed to assess the expression of FABP4 and adiponectin in paired blood and synovial fluid from OA patients, and to examine whether the infrapatellar fat pad (IPFP) from OA subjects would release FABP4 and adiponectin similar to that of donor-matched subcutaneous adipose tissue (ScAT). Materials and Methods: Plasma, synovial fluid, ScAT, and IPFP of 20 OA patients (4 males and 16 females) were collected during total knee arthroplasty. Levels of FABP4 and adiponectin were measured in plasma, synovial fluid, and fat conditioned media using ELISA (AIS, HKU). Results: Levels of FABP4 were significantly higher in IPFP media than ScAT (p = 0.015), while the same were significantly higher in synovial fluid than in plasma (p < 0.001). There were no significant differences of adiponectin levels between IPFP and ScAT media (p = 0.737). Plasma levels of adiponectin were significantly higher than synovial fluid (p < 0.001). Discussion and Conclusion: The OA patients exhibit an inflammatory state in local environment (IPFP and synovial fluid) compared with systemic environment (ScAT and plasma). The IPFP may play a key role in OA inflammation and may be an important resource of inflammatory mediators in synovial fluid.postprin

Research advances on the anti-aging profile of Fructus lycii: An ancient Chinese herbal medicine

Fructus lycii is a common Chinese herbal medicine used in China for nearly 2000 years. It has beneficial effects on eyes, liver and kidneys; and it has long been considered to be an anti-aging herb in ancient Chinese medicine. Modern studies have partially probed the magic anti-aging property of F. lycii. The beneficial effects of F. lycii on aging are largely attributed to its bioactive components such as polysaccharides, carotenoids and flavonoids. This review focuses on the anti-aging aspect of F. lycii, elaborating the bioactive ingredients accounting for the property, anti-aging pharmacology in terms of its antioxidation capacity, immunomodulative effect and neuroprotective activity. Copyright ©2008 The Berkeley Electronic Press. All rights reserved.published_or_final_versio

PExFInS: An Integrative Post-GWAS Explorer for Functional Indels and SNPs

Expression quantitative trait loci (eQTLs) mapping and linkage disequilibrium (LD) analysis have been widely employed to interpret findings of genome-wide association studies (GWAS). With the availability of deep sequencing data of 423 lymphoblastoid cell lines (LCLs) from six global populations and the microarray expression data, we performed eQTL analysis, identified more than 228 K SNP cis-eQTLs and 21 K indel cis-eQTLs and generated a LCL cis-eQTL database. We demonstrate that the percentages of population-shared and population-specific cis-eQTLs are comparable; while indel cis-eQTLs in the population-specific subsection make more contribution to gene expression variations than those in the population-shared subsection. We found cis-eQTLs, especially the population-shared cis-eQTLs are significantly enriched toward transcription start site. Moreover, the National Human Genome Research Institute cataloged GWAS SNPs are enriched for LCL cis-eQTLs. Specifically, 32.8% GWAS SNPs are LCL cis-eQTLs, among which 12.5% can be tagged by indel cis-eQTLs, suggesting the fundamental contribution of indel cis-eQTLs to GWAS association signals. To search for functional indels and SNPs tagging GWAS SNPs, a pipeline Post-GWAS Explorer for Functional Indels and SNPs (PExFInS) has been developed, integrating LD analysis, functional annotation from public databases, cis-eQTL mapping with our LCL cis-eQTL database and other published cis-eQTL datasets.published_or_final_versio

Residual stress measurement in thin films using the semi-destructive ring-core drilling method using Focused Ion Beam

In the present study, residual stress evaluation in thin films was achieved using a semi-destructive trench-cutting method. Focused Ion Beam (FIB) was employed to introduce the strain relief by ring-core milling, i.e. creating a trench around an "island". Either SEM or FIB imaging can be used to record sequences of images for strain change evaluation by Digital Image Correlation (DIC) analysis of micrographs. A regular array of shallow holes was drilled on a thin overlayer of Pt (∼100nm) deposited on to the film prior to patterning and trenching, in order to reduce the damage introduced by the ion beam during imaging and to assist the DIC strain evaluation by adding traceable markers. Finite Element (FE) simulation was also carried out to predict the curves for strain relief as a function of milling depth, and compared with the experimental measurements, which show good agreement with each other. An empirical mathematical description of the curves was proposed that allows efficient residual stress evaluation in thin solid films. © 2011 Published by Elsevier Ltd

Association between FCGR3A polymorphisms and periodontitis in Hong Kong Chinese

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Effects of Huanglian-Jie-Du-Tang and its modified formula on the modulation of amyloid-β precursor protein processing in Alzheimer's disease models.

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Grain Boundary Induced Bias Instability in Soluble Acene-Based Thin-Film Transistors

Since the grain boundaries (GBs) within the semiconductor layer of organic field-effect transistors (OFETs) have a strong influence on device performance, a substantial number of studies have been devoted to controlling the crystallization characteristics of organic semiconductors. We studied the intrinsic effects of GBs within 5,11-bis(triethylsilylethynyl) anthradithiophene (TES-ADT) thin films on the electrical properties of OFETs. The GB density was easily changed by controlling nulceation event in TES-ADT thin films. When the mixing time was increased, the number of aggregates in as-spun TES-ADT thin films were increased and subsequent exposure of the films to 1,2-dichloroethane vapor led to a significant increase in the number of nuleation sites, thereby increasing the GB density of TES-ADT spherulites. The density of GBs strongly influences the angular spread and crystallographic orientation of TES-ADT spherulites. Accordingly, the FETs with higher GB densities showed much poorer electrical characteristics than devices with lower GB density. Especially, GBs provide charge trapping sites which are responsible for bias-stress driven electrical instability. Dielectric surface treatment with a polystyrene brush layer clarified the GB-induced charge trapping by reducing charge trapping at the semiconductor-dielectric interface. Our study provides an understanding on GB induced bias instability for the development of high performance OFETs