Publications

This paper investigates the influence of the interface between a gold or silver metal electrode and an n-alkyl SAM (supported on that electrode) on the rate of charge transport across junctions with structure Met(Au or Ag)(TS)/A(CH2)nH//Ga2O3/EGaIn by comparing measurements of current density, J(V), for Met/AR = Au/thiolate (Au/SR), Ag/thiolate (Ag/SR), Ag/carboxylate (Ag/O2CR), and Au/acetylene (Au/C≡CR), where R is an n-alkyl group. Values of J0 and β (from the Simmons equation) were indistinguishable for these four interfaces. Since the anchoring groups, A, have large differences in their physical and electronic properties, the observation that they are indistinguishable in their influence on the injection current, J0 (V = 0.5) indicates that these four Met/A interfaces do not contribute to the shape of the tunneling barrier in a way that influences J(V).

Introduction Forced vital capacity (FVC) is a more powerful predictor of mortality than the ratio of forced expiratory volume in one second to FVC (Burney et al. Thorax 2011;66:49-54). Reduced FVC is associated with low birth weight (BW) and low grade inflammation and low BW is also associated with low grade inflammation. BW could therefore explain the association between FVC and inflammation. We tested this hypothesis in the Northern Finland 1966 birth cohort by examining the associations between FVC, systemic inflammation and BW. Methods Using linear regression we examined the association between FVC and BW and whether adjusting for early life factors (ELF) such as maternal smoking, maternal height and weight before pregnancy explain this association. We then used linear regression to determine the association between FVC and inflammatory markers and whether adjusting for BW and other ELF accounted for the association between FVC and inflammatory markers. Results FVC in adulthood increased by 92mL (95% confidence interval (CI): 56 to 130) for each kilogram increase in BW. Adjusting for ELF did not substantially change this association. As BW rose levels of C-reactive protein (CRP) and white blood cell count (WBC) in adulthood fell. One standard deviation (SD) increase of CRP was associated with a 53 mL reduction in FVC (95% CI: -71 to -35) and one SD increase of WBC was associated with a 24 mL reduction in FVC (95% CI: -42 to -5.8). Adjusting for BW did not substantially alter the associations between FVC and CRP or WBC. Conclusions FVC is independently associated with birth weight, CRP and WBC. However the association of FVC with CRP or WBC is not explained by variation in BW.

Two complementary simulation methodologies for ductile fracture in large sheet metal components are presented and evaluated in this paper. The first approach is based on the phenomenological dilatational plasticity-damage model developed by Woelke and Abboud [46], which accounts for pressure-dependent volumetric damage growth through a scalar damage variable. The damage function represents phenomenologically micromechanical changes the material undergoes during the process of necking. Secondly, the cohesive zone model with an opening mode traction–separation law is employed to simulate the same ductile fracture problems accounting for significant variation of the multiaxial stress state along the crack path. Both methods are examined as to their capabilities to reproduce and predict the outcome of large-scale experimental fracture tests of welded and un-welded ductile plates subjected to large-scale penetration, simulating an idealized ship grounding. The results of the current study indicate that, with appropriate calibration, both approaches can be successfully employed to simulate ductile fracture in structural components under multiaxial stress. The advantages and shortcomings of each approach is discussed from the point of view of post-test numerical investigation as well as its predictive capabilities as an engineering tool.

Recent genome-wide association (GWA) studies described 95 loci controlling serum lipid levels. These common variants explain ∼25% of the heritability of the phenotypes. To date, no unbiased screen for gene–environment interactions for circulating lipids has been reported. We screened for variants that modify the relationship between known epidemiological risk factors and circulating lipid levels in a meta-analysis of genome-wide association (GWA) data from 18 population-based cohorts with European ancestry (maximum N = 32,225). We collected 8 further cohorts (N = 17,102) for replication, and rs6448771 on 4p15 demonstrated genome-wide significant interaction with waist-to-hip-ratio (WHR) on total cholesterol (TC) with a combined P-value of 4.79×10−9. There were two potential candidate genes in the region, PCDH7 and CCKAR, with differential expression levels for rs6448771 genotypes in adipose tissue. The effect of WHR on TC was strongest for individuals carrying two copies of G allele, for whom a one standard deviation (sd) difference in WHR corresponds to 0.19 sd difference in TC concentration, while for A allele homozygous the difference was 0.12 sd. Our findings may open up possibilities for targeted intervention strategies for people characterized by specific genomic profiles. However, more refined measures of both body-fat distribution and metabolic measures are needed to understand how their joint dynamics are modified by the newly found locus.

No abstract is provided for this article.

No abstract is provided for this article.

Wiederkehrender Zusammenbruch: Die Dynamik der Kontaktelektrifizierung einer über eine isolierende Platine rollenden Metallkugel wurde untersucht. Die Daten verweisen auf einen Ionentransfer als Aufladungsprozess (siehe Schema), der durch wiederkehrende Entladungen aufgrund von dielektrischem Luftdurchschlag unterbrochen wird.

Adiponectin is an adipocyte-derived hormone that has shown anti-inflammatory and antiatherogenic effects. We assessed the associations of variants in the adiponectin gene (ADIPOQ) with circulating adiponectin levels and cardiovascular risk among women with type 2 diabetes. Of 989 diabetic women from the Nurses’ Health Study, 285 developed cardiovascular disease (CVD) during follow-up through 2000. We genotyped five ADIPOQ polymorphisms in the CVD case and control subjects. A promoter polymorphism −11365C→G was significantly associated with lower plasma adiponectin levels (P = 0.004). The homozygotes of allele −4034C were significantly associated with ∼60% increased cardiovascular risk (odds ratio 1.62 [95% CI 1.07–2.45]). Adjustment for age, BMI, and other covariates did not appreciably change the associations. In addition, a common haplotype possessing allele +276T (CAATT) was associated with a significantly lower CVD risk than the most common haplotype (CAATG) (0.70 [0.50–0.98]). In our meta-analysis of 827 CVD case and 1,887 CVD-free control subjects, polymorphism +276G→T was significantly associated with ∼45% (20–62%) decreased CVD risk under a recessive inheritance mode in diabetic patients. In conclusion, ADIPOQ promoter polymorphism −11365C→G was associated with plasma adiponectin levels, whereas polymorphisms −4034A→C and +276G→T were associated with CVD risk in diabetic patients.

An axisymmetric flow-focusing microfluidic device (AFFD) is described. The AFFD (see Figure, top) produces micrometer-sized (50–300 μm) polymer-coated droplets (see Figure, bottom) with narrow size distributions (< 5 %). The axisymmetric geometry confines droplets to the central axis of the channel and prevents them from being sheared or damaged at the channel walls. The device is used to prepare aqueous droplets encapsulated in nylon-6,6 membranes by carrying out interfacial polymerization reactions in situ.

The freezing of water can initiate at electrically conducting electrodes kept at a high electric potential or at charged electrically insulating surfaces. The microscopic mechanisms of these phenomena are unknown, but they must involve interactions between water molecules and electric fields. This paper investigates the effect of uniform electric fields on the homogeneous nucleation of ice in supercooled water. Electric fields were applied across drops of water immersed in a perfluorinated liquid using a parallel-plate capacitor; the drops traveled in a microchannel and were supercooled until they froze due to the homogeneous nucleation of ice. The distribution of freezing temperatures of drops depended on the rate of nucleation of ice, and the sensitivity of measurements allowed detection of changes by a factor of 1.5 in the rate of nucleation. Sinusoidal alternation of the electric field at frequencies from 3 to 100 kHz prevented free ions present in water from screening the electric field in the bulk of drops. Uniform electric fields in water with amplitudes up to (1.6 ± 0.4) × 105 V/m neither enhanced nor suppressed the homogeneous nucleation of ice. Estimations based on thermodynamic models suggest that fields in the range of 107−108 V/m might cause an observable increase in the rate of nucleation.

Polycystic ovary syndrome (PCOS) is a common reproductive disorder associated with metabolic disturbances including obesity, insulin resistance and diabetes mellitus. Here we investigate whether changes in the metabolic profile of PCOS women are driven by increased tendency to obesity or are specific features of PCOS related to increased testosterone levels. We conducted an NMR metabolomics association study of PCOS cases (n=145) and controls (n=687) nested in a population-based birth cohort (n=3127). Subjects were 31 years old at examination. The main analyses were adjusted for waist circumference (WC) as a proxy measure of central obesity. Subsequently, metabolite concentrations were compared between cases and controls within pre-defined WC strata. In each stratum, additional metabolomics association analyses with testosterone levels were conducted separately among cases and controls. Overall, women with PCOS showed more adverse metabolite profiles than the controls. Four lipid fractions in different subclasses of very low density lipoprotein (VLDL) were associated with PCOS, after adjusting for WC and correction for multiple testing (P<0.002). In stratified analysis the PCOS women within large WC strata (⩾98 cm) had significantly lower high density lipoprotein (HDL) levels, Apo A1 and albumin values compared with the controls. Testosterone levels were significantly associated with VLDL and serum lipids in PCOS cases with large WC but not in the controls. The higher testosterone levels, adjusted for WC, associated adversely with insulin levels and HOMA IR in cases but not in the controls. Our findings show that both abdominal obesity and hyperandrogenism contribute to the dyslipidaemia and other metabolic traits of PCOS which all may negatively contribute to the long-term health of women with PCOS.