Method to characterize a thermal diode in saturated steam atmosphere.

We present a novel measurement method for the characterization of thermal diodes in a saturated steam atmosphere. A measuring setup has been developed in which two pressure sensors are integrated. Using a developed analytical model, the heat flow, the volume flow, and the cracking pressure are determined from the measured absolute pressures and the pressure difference. The analytical model was verified using a flow through an orifice. We first calculated the volume flow through the orifice, with a diameter of 3 mm, using the Reader-Harris equation and then compared it to experimentally determined values. The experimentally determined values showed a discrepancy of 9%. With the measurement setup, we have characterized a check valve developed for magnetocaloric heat pumps, which has a thermally rectifying behavior. The developed check valve consists of three spring arms, which are radially attached to a valve disk. The heat flow through the check valve in the forward direction is 166 W for water, 239 W for ethanol, and 547 W for methanol at a temperature difference of 1 K. In the reverse direction, the heat flow is -0.03 W at a temperature difference of -1 K. For methanol, this corresponds to a rectification coefficient of more than 18 000.

CD226 Gly307Ser association with multiple autoimmune diseases.

Genome-wide association studies provide insight into multigenic diseases through the identification of susceptibility genes and etiological pathways. In addition, the identification of shared variants among autoimmune disorders provides insight into common disease pathways. We previously reported an association of a nonsynonymous single nucleotide polymorphism (SNP) rs763361/Gly307Ser in the immune response gene CD226 on chromosome 18q22 with type 1 diabetes (T1D) susceptibility. Here, we report efforts toward identifying the causal variant by exonic resequencing and tag SNP mapping of the 18q22 region in both T1D and multiple sclerosis (MS). In addition to the analysis of newly available samples in T1D (2088 cases and 3289 controls) and autoimmune thyroid disease (AITD) (821 cases and 1920 controls), resulting in strong support for the Ser(307) association with T1D (P=3.46 x 10(-9)) and continued potential evidence for AITD (P=0.0345), we provide evidence for association of Gly307Ser with MS (P=4.20 x 10(-4)) and rheumatoid arthritis (RA) (P=0.017). The Ser(307) allele of rs763361 in exon 7 of CD226 predisposes to T1D, MS, and possibly AITD and RA, and based on the tag SNP analysis, could be the causal variant.

Peroxisome proliferator-activated receptor and farnesoid X receptor ligands differentially regulate sebaceous differentiation in human sebaceous gland organ cultures in vitro.

BACKGROUND: Nuclear hormone receptors are important in the regulation of epidermal differentiation and have been implicated in lipid metabolism. In particular, there is evidence suggesting that the activation of peroxisome proliferator-activated receptors (PPARs) is an important factor in the regulation of sebocyte lipogenesis. OBJECTIVES: To determine the role of PPARs, farnesoid X receptor (FXR) and other orphan nuclear hormone receptors in sebaceous gland function in vitro by investigating the biochemical effects of appropriate ligands, and by establishing the RNA and protein expression patterns of a number of nuclear receptors in sebaceous glands ex vivo. METHODS: Human chest sebaceous glands were maintained in vitro as freshly isolated and as 7-day cultured whole organs. We then studied the effects of appropriate ligands on the glandular rates of lipogenesis and DNA synthesis, as well as determining the mRNA (reverse transcription-polymerase chain reaction) and protein expression patterns (immunohistochemistry/immunoblotting) of the nuclear hormone receptors of interest. RESULTS: PPAR ligands, but not FXR ligands, inhibited sebaceous lipogenesis, in particular the PPARalpha ligands LY 171883 and WY 14643, and the PPARgamma ligands BRL 49653 and 15-deoxy-Delta-12,14-prostaglandin J(2). We detected RNA expression of PPARalpha, PPARbeta, PPARgamma, retinoid X receptor alpha, liver X receptor alpha (LXRalpha) and pregnane X receptor but not FXR in freshly isolated and 7-day maintained sebaceous glands. PPARalpha, PPARbeta, PPARgamma and LXRalpha protein were detected in nuclear extracts of sebaceous glands. CONCLUSIONS: We conclude that activation of nuclear hormone receptors, in particular activation of PPARalpha and PPARgamma, can regulate lipogenesis in human sebaceous glands. As suppression of sebum secretion is associated with reduced acne activity, the nuclear hormone receptors involved may open new avenues in the development of novel acne treatments.

Testing the possible negative association of type 1 diabetes and atopic disease by analysis of the interleukin 4 receptor gene.

Variations in the interleukin 4 receptor A (IL4RA) gene have been reported to be associated with atopy, asthma, and allergy, which may occur less frequently in subjects with type 1 diabetes (T1D). Since atopy shows a humoral immune reactivity pattern, and T1D results from a cellular (T lymphocyte) response, we hypothesised that alleles predisposing to atopy could be protective for T1D and transmitted less often than the expected 50% from heterozygous parents to offspring with T1D. We genotyped seven exonic single nucleotide polymorphisms (SNPs) and the -3223 C>T SNP in the putative promoter region of IL4RA in up to 3475 T1D families, including 1244 Finnish T1D families. Only the -3223 C>T SNP showed evidence of negative association (P=0.014). There was some evidence for an interaction between -3233 C>T and the T1D locus IDDM2 in the insulin gene region (P=0.001 in the combined and P=0.02 in the Finnish data set). We, therefore, cannot rule out a genetic effect of IL4RA in T1D, but it is not a major one.