Application of liquid chromatography-direct-electron ionization-MS in an in vitro dermal absorption study: quantitative determination of trans-cinnamaldehyde

We propose a new analytical approach, based on liquid chromatography (LC) coupled to electron ionization mass spectrometry (EI-MS), using a Direct-EI interface, for dermal absorption evaluation studies. Penetration through the skin of a given compound is evaluated by means of in vitro assays using diffusion cells. Currently, the most popular approach for the analysis of skin and fluid samples is LC coupled to electrospray ionization tandem mass spectrometry (ESI-MS/MS). However, this technique is largely affected by sample matrix interferences that heavily affect quantitative evaluation. LC-Direct-EI-MS is not affected by matrix interference and produces accurate quantitative data in a wide range of concentrations. Trans-cinnamaldehyde was chosen as test substance and applied in a suitable dosing vehicle on dermatomed human skin sections. This compound was then quantified in aliquots of receptor solution, skin extract, cell wash, skin wash, carbon filter extract, cotton swab extract, and tape strip digest. On column limits of detection (LOD) and limits of quantitation (LOQ) of 0.1 and 0.5 ng/μL, respectively, were achieved. Calibration showed satisfactory linearity and precision for the concentration range of interest. Matrix effects (ME) were evaluated for all sample types, demonstrating the absence of both signal enhancement and signal suppression. The Direct-EI absorption profile was compared with that obtained with liquid scintillation counting (LSC), a recognized ME free approach. A good correlation was found with all samples and for the overall recovery of the dosed substance.     

Self‐perceived quality of sleep and mortality in Norwegian dialysis patients

Sleep complaints are prevalent and associated with poor health‐related quality of life (HRQoL), depression and possibly mortality in dialysis patients. This study aimed to explore possible associations between sleep quality, daytime sleepiness and mortality in dialysis patients. In this study, 301 dialysis patients were followed up to 4.3 years. HRQoL was evaluated at baseline with the Kidney Disease and Quality of Life—Short Form (KDQoL‐SF), depression with Beck Depression Inventory (BDI), sleep quality with Pittsburgh Sleep Quality Index and daytime sleepiness with Epworth Sleepiness Scale. The single item “on a scale from 0–10, how would you evaluate your sleep?” in the sleep subscale in KDQoL‐SF was used to identify poor (0–5) and good sleepers (6–10). A total of 160 patients (53.3%) were characterized as poor sleepers. They were younger (r = 0.241, P < 0.001), had more depression (BDI: 8.72 ± 6.79 vs. 13.60 ± 8.04, P < 0.001), a higher consumption of hypnotics and antidepressants and reduced HRQoL (Mental Component Summary score: 45.4 ± 11.0 vs. 50.0 ± 10.4, P < 0.001. Physical Component Summary score: 35.0 ± 9.9 vs. 38.5 ± 10.5, P = 0.004). In multivariate analyses, poor sleepers had nearly a twofold increase in mortality risk (hazard ratio [HR] 1.92, confidence interval [CI] 1.10‐3.35, P = 0.022). Daytime sleepiness was not related to mortality (HR 1.01, CI 0.95‐1.08, P = 0.751). Sleep complaints predicted increased mortality risk in dialysis patients and should therefore be routinely assessed. Further studies are needed to find suitable treatment options for poor sleep in dialysis patients as it may affect both HRQoL and survival.     

Effects of cultivars on ensiling characteristics,chemical composition,and ruminal degradability of pea silage

A study was conducted to determine the effects of cultivar on ensiling characteristics, chemical composition and ruminal nutrient degradability of pea (Pisum sativum L.) silage. The cultivars evaluated were Lenca (L), Carneval (C), and Delta (D). Peas were field-grown and forage was harvested and ensiled in mini-silos for 0, 2, 4, 8, 16, and 70 d. The ensiled forage of all cultivars went through a rapid fermentation with a sharp reduction in pH during the first 2 days of ensiling. Extensive proteolysis took place between 0 and 2 d as indicated by a reduction in true protein and neutral detergent insoluble protein (NDICP) and an increase in nonprotein nitrogen. Chemical analysis of the 70 d silage showed that cultivar L contained higher neutral detergent fiber (NDF) and acid detergent fiber and lower starch levels than C and D. Crude protein was highest for C (20.5% DM), intermediate for D (19.0% DM) and lowest for L (17.9% DM). Distribution of protein fractions showed that L contains lower soluble protein and higher NDICP levels than the other two pea cultivars. However, no difference in acid detergent insoluble protein levels was observed between the three cultivars. Results of the in situ incubation experiment indicated that L had lower ruminal DM (69.2 vs 74.0%) and CP (84.1 vs 90.6%) degradabilities than C or D. However, ruminal degradability of NDF was similar among the three cultivars (average of 32.9%). It was concluded that chemical composition and ruminal nutrient degradability of pea silage are significantly influenced by cultivars.     

Etude des mécanismes de formation de quelques produits identifiés après irradiation gamma de l'amidon de maïs

Studies of the Formation Processes of Some Identified Radiolysis Products after Gamma Irradiation of Maize Starch . From the variations in the concentrations of different starch radiolysis products, studied as function of starch water content and of oxygen pressure, it has been possible to suggest different formation processes. The initied break of the C O C linkages as well as the further rearrangement of the radicals formed or their reactions with water and oxygen explain the observed rearrangements. Water generally has a protector effect, which can be interpreted as an inhibition of primary radical transformation. As for oxygen, its fixation on a carbon radical may account for the generally stimulating action of this gas.     

Silica‐Based,Organically Modified Host Material for Waveguide Structuring by Two‐Photon‐Induced Photopolymerization

The three‐dimensional fabrication of optical waveguides has gained increasing interest in recent years to establish interconnections between electrical components on a very small scale where copper circuits encounter severe limitations. In this work the application of optically clear, organically modified porous silica monoliths and thin films as a host material for polymeric waveguides to be inscribed into the solid host structure by two‐photon‐induced photopolymerization is investigated. Porosity is generated using a lyotropic liquid crystalline surfactant/solvent system as a template for the solid silica material obtained by a sol–gel transition of a liquid precursor. In order to reduce the brittleness of the purely inorganic material, organic–inorganic co‐precursor molecules that contain poly(ethylene glycol) chains are synthesized and added to the mixture, which successfully suppresses macroscopic cracking and leads to flexible thin films. The structure of the thus‐obtained porous organic–inorganic hybrid material is investigated by atomic force microscopy. It is shown that the modified material is suitable for infiltration with photocurable monomers and functional polymeric waveguides can be inscribed by selective two‐photon‐induced photopolymerization.     

Fusarium mycotoxins in cereals harvested from Hungarian fields

The Fusarium mycotoxins deoxynivalenol (DON), zearalenone (ZEN) and T-2 frequently contaminate grain crops in Middle and Eastern Europe. In this survey, 116 cereal samples (maize, wheat, barley and oat) were examined for DON, ZEN and T-2 mycotoxins. Samples were collected from different areas in two Hungarian regions (North and South Transdanubia). The method of analysis was indirect competitive ELISA. Maize was the most contaminated grain regarding DON (86%), ZEN (41%) and T-2 (55%) toxins. The average results of the deoxynivalenol and zearalenone tests of maize proved to be significantly higher than those of barley or oat. DON was the most represented Fusarium mycotoxin followed by T-2 and ZEN. The examination of these mycotoxins would be necessary at a larger scale as to re-evaluate permissible levels, so increase of the monitoring programme would be advisable for the future.     

Temperature compensated CMOS ring VCO for MEMS gas sensor

This paper presents a CMOS voltage controlled ring oscillator with temperature compensation circuit suitable for low-cost and low-power gas sensor. To operate at low frequency, a control voltage generated by a CMOS bandgap reference is described and the measurement results of the fabricated chips are presented. The output voltage of the reference is set by resistive subdivision. In order to achieve small area and low power consumption, n-well resistors are used. This design features a reference voltage of 1 V. The chip is fabricated in AMS 0.35 μm CMOS process with an area of 0.032 mm². Operating at 1.25 V, the output frequency is within 200 ± l0 kHz over the temperature range of ?25 to 80 °C with a power consumption of 810 μW.     

Bioactivity and corrosion behavior of magnesium barrier membranes

In the current research, magnesium and its alloys have been intensively studied as resorbable implant materials. Magnesium materials combine their good mechanical properties with bioactivity, which make them interesting for guided bone regeneration and for the application as barrier membranes. In this study, the in vitro degradation behavior of thin magnesium films was investigated in cell medium and simulated body fluid. Three methods were applied to evaluate corrosion rates: measurements of (i) the gaseous volume evolved during immersion, (ii) volume change after immersion, and (iii) polarization curves. In this comparison, measurements of H₂ development in Dulbecco's modified Eagle's medium showed to be the most appropriate method, exhibiting a corrosion rate of 0.5 mm·year^?1. Observed oxide and carbon contamination have a high impact on controlled degradation, suggesting that surface treatment of thin foils is necessary. The bioactivity test showed positive results; more detailed tests in this area are of interest.     

Geometrical analysis of woven fabric microstructure based on micron-resolution computed tomography data

The global mechanical properties of textiles such as elasticity and strength, as well as transport properties such as permeability depend strongly on the microstructure of the textile. Textiles are heterogeneous structures with highly anisotropic material properties, including local fiber orientation and local fiber volume fraction. In this paper, an algorithm is presented to generate a virtual 3D–model of a woven fabric architecture with information about the local fiber orientation and the local fiber volume fraction. The geometric data of the woven fabric impregnated with resin was obtained by micron-resolution computed tomography (μCT). The volumetric μCT-scan was discretized into cells and the microstructure of each cell was analyzed and homogenized. Furthermore, the discretized data was used to calculate the local permeability tensors of each cell. An example application of the analyzed data is the simulation of the resin flow through a woven fabric based on the determined local permeability tensors and on Darcy’s law. The presented algorithm is an automated and robust method of going from μCT-scans to structural or flow models.