A functional polymorphism in the SPINK5 gene is associated with asthma in a Chinese Han Population

<p>Abstract</p> <p>Background</p> <p>Mutation in <it>SPINK5 </it>causes Netherton syndrome, a rare recessive skin disease that is accompanied by severe atopic manifestations including atopic dermatitis, allergic rhinitis, asthma, high serum IgE and hypereosinophilia. Recently, single nucleotide polymorphism (SNP) of the <it>SPINK5 </it>was shown to be significantly associated with atopy, atopic dermatitis, asthma, and total serum IgE. In order to determine the role of the <it>SPINK5 </it>in the development of asthma, a case-control study including 669 asthma patients and 711 healthy controls in Han Chinese was conducted.</p> <p>Methods</p> <p>Using PCR-RFLP assay, we genotyped one promoter SNP, -206G>A, and four nonsynonymous SNPs, 1103A>G (Asn368Ser), 1156G>A (Asp386Asn), 1258G>A (Glu420Lys), and 2475G>T (Glu825Asp). Also, we analyzed the functional significance of -206G>A using the luciferase reporter assay and electrophoresis mobility shift assay.</p> <p>Results</p> <p>we found that the G allele at SNP -206G>A was associated with increased asthma susceptibility in our study population (p = 0.002, odds ratio 1.34, 95% confidence interval 1.11–1.60). There was no significant association between any of four nonsynonymous SNPs and asthma. The A allele at -206G>A has a significantly higher transcriptional activity than the G allele. Electrophoresis mobility shift assay also showed a significantly higher binding efficiency of nuclear protein to the A allele compared with the G allele.</p> <p>Conclusion</p> <p>Our findings indicate that the -206G>A polymorphism in the <it>SPINK5 </it>is associated with asthma susceptibility in a Chinese Han population.</p

Thermal contact resistance in carbon nanotube enhanced heat storage materials

Solid-liquid phase change is one of the most favorable means of compact and economical heat storage in the built environment. In such storage systems, the vast available solar heat is stored as latent heat in the storage materials. Recent studies suggest using sugar alcohols as seasonal heat storage materials for their large storage capacity, moderate melting point, and evident supercooling effects. However, the heat transfer in such materials is sluggish and hence carbon structures are proposed to enhance their overall heat conductivity. In this work, we focus on sugar alcohol - carbon nanotube system, analyze the heat transfer in the radial direction of the nanotube using molecular dynamics simulations. The thermal contact resistance is calculated using Nos´e-Hoover dynamics and is found dependent on the diameter of the tubes. We validate our results using water - nanotube simulations. Then the simulation method is extended to sugar alcohol - nanotube systems

Nanoscale heat transfer in carbon nanotube - sugar alcohol composites as heat storage materials

Nanoscale carbon structures such as graphene and carbon nanotubes\u3cbr/\u3e(CNTs) can greatly improve the effective thermal conductivity of thermally sluggish heat storage materials, such as sugar alcohols (SAs). The specific improvement depends on the heat transfer rate across the carbon structure. Besides, the heat transfer rate is further dependent on the material and the CNT diameter. In this paper, molecular dynamics simulations are applied to graphene/CNT-SA interfacial systems. Using erythritol and xylitol as model materials, we find the cross-plane thermal contact conductance to decrease as the CNT diameter decreases, with an exception for CNT(7,7). A phonon mode analysis is carried out to explain the general decreasing trend. The larger phonon mode mismatch observed between the molecules on both sides of smaller diameter CNTs is found to be a finite size effect of the confinement, instead of an interfacial effect. From the molecular collision point of view, a higher molecular density promotes heat transfer. In the case of CNT(7,7), the effective density of molecules enclosed in the CNT is found to be much higher than that of CNT(8,8). This may be the cause of the higher heat transfer rate across CNT(7,7). Molecular orientations and hydrogen bond structures of the molecules inside the CNTs are investigated to demonstrate the finite size effect\u3cbr/\u3eof the confinement. For graphene-SA composites, five model materials are considered and their cross-plane thermal contact conductance values fall into a narrow range

Cross-plane heat transfer through single-layer carbon structures

Graphene-based nano structures are recently proposed to function as additives to improve the conductivity of thermally sluggish phase change materials (PCMs). Based on existing researches, the improvement is dependent not only on the matrix material, but also on the geometry of the carbon structure. To gain more insight into the nano-scale thermal transport problem, we launch the current pilot research using water as the matrix material, to represent the hydroxyl-grouprich sugar alcohols as PCMs. We have found that the heat conduction across a graphene layer to water is much faster than the heat conduction to the graphene layer itself. Also, the high graphene-water thermal contact resistance fails to acknowledge the fast thermal kinetics of the low frequency phonons. In the investigation of the geometry effect, the cross-plane heat transfer coefficient is found to decrease with decreasing CNT diameter with an exception of the CNT(9,9)