Serum methylarginines and spirometry-measured lung function in older adults

Rationale: Methylarginines are endogenous nitric oxide synthase inhibitors that have been implicated in animal models of lung disease but have not previously been examined for their association with spirometric measures of lung function in humans. Objectives: This study measured serum concentrations of asymmetric and symmetric dimethylarginine in a representative sample of older community-dwelling adults and determined their association with spirometric lung function measures. Methods: Data on clinical, lifestyle, and demographic characteristics, methylated arginines, and L-arginine (measured using LC-MS/MS) were collected from a population-based sample of older Australian adults from the Hunter Community Study. The five key lung function measures included as outcomes were Forced Expiratory Volume in 1 second, Forced Vital Capacity, Forced Expiratory Volume in 1 second to Forced Vital Capacity ratio, Percent Predicted Forced Expiratory Volume in 1 second, and Percent Predicted Forced Vital Capacity. Measurements and Main Results: In adjusted analyses there were statistically significant independent associations between a) higher asymmetric dimethylarginine, lower Forced Expiratory Volume in 1 second and lower Forced Vital Capacity; and b) lower L-arginine/asymmetric dimethylarginine ratio, lower Forced Expiratory Volume in 1 second, lower Percent Predicted Forced Expiratory Volume in 1 second and lower Percent Predicted Forced Vital Capacity. By contrast, no significant associations were observed between symmetric dimethylarginine and lung function. Conclusions: After adjusting for clinical, demographic, biochemical, and pharmacological confounders, higher serum asymmetric dimethylarginine was independently associated with a reduction in key measures of lung function. Further research is needed to determine if methylarginines predict the decline in lung function

Sex differences in the associations between L-arginine pathway metabolites, skeletal muscle mass and function, and their responses to resistance exercise, in old age

This work was supported by the Biotechnology and Biological Sciences Research Council (BB/J015911/1) and was registered at clinicaltrials.gov (ClinicalTrials. gov Identifier: NCT02843009). Supplementary email included with articlePeer reviewedPostprin

HFE gene mutations increase the risk of coronary heart disease in women

The purpose of the present study is to examine HFE gene mutations in relation to newly diagnosed (incident) coronary heart disease (CHD). In a population-based follow-up study of 7,983 individuals aged 55 years and older, we compared the risk of incident CHD between HFE carriers and non-carriers, overall and stratified by sex and smoking status. HFE mutations were significantly associated with an increased risk of incident CHD in women but not in men (hazard ratio [HR] for women = 1.7, 95% confidence interval [CI] 1.2–2.4 versus HR for men = 0.9, 95% CI 0.7–1.2). This increased CHD risk associated with HFE mutations in women was statistically significant in never smokers (HR = 1.8, 95% CI 1.1–2.8) and current smokers (HR = 3.1, 95% CI 1.4–7.1), but not in former smokers (HR = 1.3, 95% CI 0.7–2.4). HFE mutations are associated with increased risk of incident CHD in women

Realisation d'un filtre supraconducteur a 10 GHz

In this paper, we show the design, the realization and the characterization of a 10 GHz superconducting planar filter with a narrow band. At 77 K it compares favourably with a gold filter one and the results are in accordance with the simulation. The insertion loss of the superconducting filter are considered inferior to 0.2 dB at 77 K.Dans cet article, nous présentons la conception, la réalisation et la caractérisation d'un filtre planaire supraconducteur à bande étroite à 10 GHz. A 77 K ses performances sont comparables à celles d'un filtre analogue en or et en accord avec les prévisions théoriques. On estime que le filtre supraconducteur seul présente des pertes inférieures à 0,2 dB à 77 K

Study of the low frequency noise from 77 K to 300 K in NbN semiconductor thin films deposited on silicon

In this paper we present, to our knowledge, the first low frequency noise characterization of two NbNx thin films deposited on a silicon substrate. Using a transmission line model (TLM) test structure, it is checked that the noise of the contacts is negligible. From 77 K to 300 K no generation-recombination ($g$-$r$) noise is observed and both samples exhibit only 1/$f$ noise. By referring to noise studies in semiconductor materials, a first interpretation is suggested

Mesure de la conductivité complexe et de la résistance de surface de films supraconducteurs YBaCuO

We describe in this paper 2 non destructive measurement methods in microwaves (18-26 GHz) well-suited to the characterization of conducting and superconducting thin films. From the experimental values we show that it is possible to infer, without any hypothesis, the following parameters : $\sigma^*$, $R_{\rm s}$, $X_{\rm s}$ and $\lambda$ between 20 K and 300 K. Some examples are given with metallic and superconducting samples from various origins. At 22 GHz and below 75 K, YBaCuO films deposited on MgO have a surface resistance inferior to bulk copper one.Dans cet article nous décrivons 2 méthodes de mesure non destructives adaptées à la caractérisation en microondes (18-26 GHz) de films minces conducteurs et supraconducteurs. A partir des valeurs expérimentales nous montrons qu'il est possible d'en déduire les grandeurs caractéristiques à savoir $\sigma^*$, $R_{\rm s}$, $X_{\rm s}$ et $\lambda$ entre 20 K et 300 K. Nous donnons des exemples de caractérisation de films métalliques et supraconducteurs provenant de différentes origines. A 22 GHz, en dessous de 75 K, les films YBaCuO déposés sur MgO ont une résistance de surface inférieure à celle du cuivre massif

Complete microwave characterization at 36 GHz of YBaCuO thin films deposited on MgO substrates. Influence of the substrate preparation

This paper deals with the determination of $\lambda$ and Z$_s$ of YBa$_2$Cu$_3$O$_{7-\delta}$ thin films deposited on MgO singlecrystals, from 36 GHz resonant conical cavity measurements performed in the 25 K to 300 K temperature range. The results are discussed in relation with DC electrical transport properties of the films and also with substrate preparation prior to YBaCuO deposition

Low frequency noise in YBaCuO superconducting thin films deposited on MgO

In this paper we present a comparison of DC and electrical noise characteristics of high-temperature superconducting thin films. Two YBaCuO thin films deposited on MgO substrates were studied and compared. The R-T, I-V and electrical noise properties were studied for each film. Noise measurements show that they are more sensitive than the DC ones. They can give evidence of physical phenomena such as “pre-transitional superconducting effect

Développement d’électrodes innovantes pour piles à combustible réalisées sur support métallique poreux

National audienc

Doping effect on nanoscopic and macroscopic electrical properties of Barium Zirconate Titanate thin films

International audienceLead-free Barium Zirconate Titanate thin films synthesized by sol-gel process were deposited on platinized silicon substrates. Atomic and piezoresponse force microscopies analysis have revealed low values for the surface roughness and local piezoelectric loops, respectively. Nanoscopic piezoelectric and ferroelectric properties decrease with zirconium content increasing. Dielectric measurements were made up to 1 MHz at room temperature. The highest dielectric permittivity and tunability are obtained for 10% of zirconium. Dielectric loss tangent decreases with frequency, zirconium content and electric field increasing. Thin films with 20% of zirconium could be particularly interesting for electronic applications