The Role of Molecular Structure in Monte Carlo Simulations of the Secondary Electron Yield and Backscattering Coefficient from Methacrylic Acid

In this paper, we show the influence of the chemical structure of four different conformers on the secondary electron emission and backscattering of an electron beam from a gel of methacrylic acid. The conformers have different permanent dipole moments, which determines the cross sections for elastic collisions with electrons. The cross sections are used in Monte Carlo simulations of an electron beam, which enters the gel of methacrylic acid. The secondary electron yield and the backscattering coefficient are computed as a function of the beam energy

Sex-specific relationships of inflammatory biomarkers with blood pressure in older adults

Emerging evidence indicates an association between blood pressure and inflammation, yet this relationship remains unclear in older adults, despite the elevated prevalence of hypertension. We investigated the association between blood pressure, high sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and white blood cell (WBC) count in a cohort of 3571 older adults aged 65 and above, and 587 middle-aged participants (55–59 years old). In women aged 65 and above, the relationship between inflammatory markers and blood pressure was consistent, with hs-CRP and WBC emerging as predictors of high blood pressure. For hs-CRP, the adjusted odds ratio (OR) was 1.5 (95% CI, 1.07 to 2.10, P = 0.02), and for WBC, the adjusted OR was 1.41 (95% CI, 1.02 to 1.94, P = 0.04), comparing the highest to the lowest quartiles. In men, only the WBC count was significantly associated with an increased OR for high BP (adjusted OR 1.49, 95% CI, 1.09 to 2.02, P = 0.01) across quartiles. Across the entire study population, in a fully adjusted model, all inflammatory markers were modestly associated with blood pressure levels, while the effect of being over 65 years was the most significant predictor of high blood pressure (OR 1.84, 95% CI, 1.50 to 2.25, P < 0.001). The link between key inflammation markers and blood pressure in older adults varies by sex and biomarker type and may differ from the relationship observed in younger individuals. These relationships are likely to be affected by factors linked to age

The ANTENATAL multicentre study to predict postnatal renal outcome in fetuses with posterior urethral valves: objectives and design

Abstract Background Posterior urethral valves (PUV) account for 17% of paediatric end-stage renal disease. A major issue in the management of PUV is prenatal prediction of postnatal renal function. Fetal ultrasound and fetal urine biochemistry are currently employed for this prediction, but clearly lack precision. We previously developed a fetal urine peptide signature that predicted in utero with high precision postnatal renal function in fetuses with PUV. We describe here the objectives and design of the prospective international multicentre ANTENATAL (multicentre validation of a fetal urine peptidome-based classifier to predict postnatal renal function in posterior urethral valves) study, set up to validate this fetal urine peptide signature. Methods Participants will be PUV pregnancies enrolled from 2017 to 2021 and followed up until 2023 in >30 European centres endorsed and supported by European reference networks for rare urological disorders (ERN eUROGEN) and rare kidney diseases (ERN ERKNet). The endpoint will be renal/patient survival at 2 years postnatally. Assuming α = 0.05, 1–β = 0.8 and a mean prevalence of severe renal outcome in PUV individuals of 0.35, 400 patients need to be enrolled to validate the previously reported sensitivity and specificity of the peptide signature. Results In this largest multicentre study of antenatally detected PUV, we anticipate bringing a novel tool to the clinic. Based on urinary peptides and potentially amended in the future with additional omics traits, this tool will be able to precisely quantify postnatal renal survival in PUV pregnancies. The main limitation of the employed approach is the need for specialized equipment. Conclusions Accurate risk assessment in the prenatal period should strongly improve the management of fetuses with PUV

Binary-Encounter Model for Direct Ionization of Molecules by Positron-Impact

We introduce two models for the computation of direct ionization cross sections by positron impact over a wide range of collision energies. The models are based on the binary-encounter-Bethe model and take into account an extension of the Wannier theory. The cross sections computed with these models show good agreement with experimental data. The extensions improve the agreement between theory and experiment for collision energies between the first ionization threshold and the peak of the cross section. The models are based on a small set of parameters, which can be computed with standard quantum chemistry program packages

Binary-Encounter Model for Direct Ionization of Molecules by Positron-Impact

We introduce two models for the computation of direct ionization cross sections by positron impact over a wide range of collision energies. The models are based on the binary-encounter-Bethe model and take into account an extension of the Wannier theory. The cross sections computed with these models show good agreement with experimental data. The extensions improve the agreement between theory and experiment for collision energies between the first ionization threshold and the peak of the cross section. The models are based on a small set of parameters, which can be computed with standard quantum chemistry program packages

Induction of DNA strand breaks by dental composite components compared to X-ray exposure in human gingival fibroblasts

The toxicity of dental composites has been attributed to the release of residual monomers from polymerized resin-based composites due to degradation processes or incomplete polymerization. Some of these eluted substances have a genotoxic potential. We tested the hypothesis that realistic concentrations (and/or worst case concentrations/situations) of bisphenol-A-glycidyldimethacrylate (BisGMA), triethyleneglycol dimethacrylate (TEGDMA), 2-hydroxyethyl methacrylate (HEMA) and methyl methacrylate (MMA) found in elution experiments can cause DNA strand breaks in human gingival fibroblasts (HGF). Such DNA damage was compared with that resulting from ionizing radiation coming from natural sources, dental radiography or tumor therapy. TEGDMA, HEMA and MMA did not induce DNA strand breaks at concentrations of up to 10 mM. About 24 h after incubation with 0.25 mM BisGMA, significantly more DNA strand breaks were found in HGF compared to controls. DNA strand breaks caused by 0.25 mM BisGMA, correspond to DNA strand breakage caused by irradiation with 4 Gy, only used in the high single-dose irradiation tumor therapy. But 0.25 mM BisGMA is more than 100-fold higher than that concentration found in worst case calculations. Therefore, our data did not support our hypothesis