Investigation of the deposition and thermal behavior of striped phases of unsymmetric disulfide self-assembled monolayers on Au(111): The case of 11-hydroxyundecyl decyl disulfide

Self-assembled monolayers (SAMs) of unsymmetric disulfides on Au(111) are used to form mixed SAMs that can be utilized in many applications. Here, we have studied 11-hydroxyundecyl decyl disulfide (CH3-(CH2)9-S-S-(CH2)11-OH, HDD) SAMs produced by supersonic molecular beam deposition and characterized by He diffraction. The film growth was monitored at different temperatures up to a coverage which corresponds to a full lying down phase and the diffraction analysis shows that below 250 K the phase is different from the phase measured above 300 K. During the annealing of the film, two phase transitions were observed, at 250 K and 350 K. The overall data suggest that the former is related to an irreversible phase separation of HDD above 250 K to decanethiolate (-S-(CH2)9-CH3, DTT) and hydroxyundecylthiolate (-S-(CH2)11-OH, MUDT), while the latter to a reversible melting of the film. Above 450 K, the specular intensity shows an increase related to film desorption and different chemisorbed states were observed with energies in the same range as observed for decanethiol (H-S-(CH2)9-CH3, DT) and mercaptoundecanol (H-S-(CH2)11-OH, MUD) SAMs

Mission-based hull-form and propeller optimization of a transom stern destroyer for best performance in the sea environment

An overview is presented of the activities conducted within the NATO STO Task Group AVT-204 to “Assess the Ability to Optimize Hull Forms of Sea Vehicles for the Best Per- formance in a Sea Environment.” The objective is the development of a greater understanding of the potential and limitations of the hydrodynamic optimization tools. These include low- and high-fidelity solvers, automatic shape modification methods, and multi-objective optimiza- tion algorithms, and are limited here to a deterministic application. The approach includes simulation-based design optimization methods from different research teams. Analysis tools include potential flow and Reynolds-averaged Navier-Stokes equation solvers. Design modifica- tion tools include global modification functions, control point based methods, and parametric modelling by hull sections and basic curves. Optimization algorithms include particle swarm optimization, sequential quadratic programming, genetic and evolutionary algorithms. The ap- plication is the hull-form and propeller optimization of the DTMB 5415 model for significant conditions, based on actual missions at sea

Research gaps and future needs for allergen prediction in food safety

The allergenicity and protein risk assessments in food safety are facing new challenges. Demands for healthier and more sustainable food systems have led to significant advances in biotechnology, the development of more complex foods, and the search for alternative protein sources. All this has increased the pressure on the safety assessment prediction approaches anchored into requirements defined in the late 90's. In 2022, the EFSA's Panel on Genetically Modified Organisms published a scientific opinion focusing on the developments needed for allergenicity and protein safety assessments of new products derived from biotechnology. Here, we further elaborate on the main elements described in this scientific opinion and prioritize those development needs requiring critical attention. The starting point of any new recommendation would require a focus on clinical relevance and the development of a fit-for-purpose database targeted for specific risk assessment goals. Furthermore, it is imperative to review and clarify the main purpose of the allergenicity risk assessment. An internationally agreed consensus on the overall purpose of allergenicity risk assessment will accelerate the development of fit-for-purpose methodologies, where the role of exposure should be better clarified. Considering the experience gained over the last 25 years and recent scientific developments in the fields of biotechnology, allergy, and risk assessment, it is time to revise and improve the allergenicity safety assessment to ensure the reliability of allergenicity assessments for food of the future

Visfatin concentration is decreased in women with gestational diabetes mellitus in the third trimester

Our aim is to investigate visfatin concentration and its relationship to glycated hemoglobin (HbA1c), insulin resistance, lipid parameters, and neonatal birth weight in women with gestational diabetes mellitus (GDM). In our study group, there were 47 women with GDM and 31 women with normal glucose tolerance (NGT) between 33-39 weeks of gestation. Plasma visfatin levels were significantly decreased in pregnant women with GDM compared to those with NGT (p=0.001). Homeostasis model assessment-insulin resistance (HOMA-IR) levels were higher in the GDM group than in the NGT group (p=0.006). In all subjects, plasma visfatin levels were negatively correlated with HOMA-IR, post-prandial blood glucose, triglycerides, and VLDL cholesterol (p<0.05). We did not observe any statistically significant correlation between the plasma visfatin levels and the selected parameters in the GDM group, but in the NGT group plasma visfatin levels were negatively correlated with HOMA-IR (r=-0.36, p=0.04). There was no correlation between visfatin concentrations and fetal birth weight in either group (p>0.05). By regression analysis, having GDM was found to be the only significant determinant (t=3.5, p=0.001) of visfatin concentration (R=0.39, r2=0.15). We conclude that women with GDM have significantly decreased visfatin concentrations in the third trimester. Future studies are required to establish the exact role of visfatin in the pathogenesis of GDM. ©2008, Editrice Kurtis

Asymmetric dimethylarginine concentrations are elevated in women with gestational diabetes

As shown in the previous studies, asymmetric dimethylarginine (ADMA) is related to endothelial dysfunction, whereas high-sensitive C-reactive protein (hCRP) is the marker of inflammation. In our study, we investigated ADMA, hCRP, and homocysteine concentrations in women with gestational diabetes mellitus (GDM) and normal glucose tolerance (NGT) during late pregnancy. Fifty-four women with GDM and 69 women with NGT between 32 and 39 weeks of gestation were included in this study. ADMA, hCRP, homocysteine, lipid parameters, glycated hemoglobin (HbA1c) levels, insulin, and homeostasis model assessment for insulin resistance (HOMA-IR) were measured. The plasma ADMA concentrations were significantly higher in GDM patients than in NGT subjects (P = 0.03) and the hCRP levels were also significantly increased in GDM group when compared with those in the NGT group (P = 0.008). However, plasma homocysteine levels did not differ between the groups (P = 0.4), while HOMA-IR, insulin, and triglyceride levels were higher in the GDM group than in the NGT group (P = 0.001, 0.002, and 0.02, respectively). The ADMA concentrations in the third trimester were positively correlated with the glucose levels the 50-g glucose challenge test (GCT) during 24-28 weeks in the whole group (r = 0.21, P = 0.02). Our results demonstrate that ADMA and hCRP are elevated in women with GDM during late pregnancy. Further studies are needed to clarify the significance and the underlying mechanisms of the elevated ADMA and hCRP levels in women with GDM. © 2010 Springer Science+Business Media, LLC

Na+/I- symporter and type 3 iodothyronine deiodinase gene expression in amniotic membrane and placenta and its relationship to maternal thyroid hormones

Placental type 3 iodothyronine deiodinase (D3) potentially protects the fetus from the elevated maternal thyroid hormones. Na+/I- symporter (NIS) is a plasma membrane glycoprotein, which mediates active iodide uptake. Our objectives were to establish the distribution of NIS and D3 gene expressions in the placenta and the amniotic membrane and to investigate the relationship between placental D3 and NIS gene expressions and maternal iodine, selenium, and thyroid hormone status. Thyroid hormones, urinary iodine concentration (UIC), and selenium levels were measured in 49 healthy term pregnant women. NIS and D3 gene expressions were studied with the total mRNA RT-PCR method in tissues from maternal placenta (n = 49), fetal placenta (n = 9), and amniotic membrane (n = 9). NIS and D3 gene expressions were shown in the fetal and maternal sides of the placenta and amniotic membrane. Mean blood selenium level was 66 ± 26.5 μg/l, and median UIC was 143 μg/l. We could not demonstrate any statistically significant relationship of spot UIC and blood selenium with NIS and D3 expression (p > 0.05). Positive correlations were found between NIS and thyroxine-binding globulin (TBG) (r = 0.3, p = 0.042) and between D3 and preoperative glucose levels (r = 0.4, p = 0.006). D3 and NIS genes are expressed in term placenta and amniotic membrane; thus, in addition to placenta, amniotic membrane contributes to regulation of maternofetal iodine and thyroid hormone transmission. Further studies are needed to clarify the relationship between maternal glucose levels and placental D3 expression and between TBG and placental NIS expression. © 2013 Springer Science+Business Media New York