Self-initiation of UV photopolymerization reactions using tetrahalogenated bisphenol A (meth)acrylates.

The potential of tetrachlorinated and tetrabrominated bisphenol A diacrylates and dimethacrylates for self-initiation of a radical photopolymerization was investigated. The kinetics of the photopolymerization of an acrylic model varnish containing halogenated monomers was studied by real-time FTIR spectroscopy, whereas the formation of reactive species and secondary products was elucidated by laser flash photolysis and product analysis by GC-MS after steady-state photolysis. The interpretation of the experimental data and the analysis of possible reaction pathways were assisted by quantum chemical calculations.

Peculiarities of the photoinitiator-free photopolymerization of pentabrominated and pentafluorinated aromatic acrylates and methacrylates.

Pentabrominated and fluorinated aromatic (meth)acrylates as well as their non-halogenated counterparts have been studied with the aim to avoid conventional photoinitiators and to overcome some negative consequences related to their use. Therefore, RTIR spectroscopy, laser flash photolysis and GC/MS were utilized. Even low concentrations (1 to 5 wt%) of brominated (meth)acrylates in the model varnish lead to initiation of a photopolymerization reaction under exposure to UV light with λ > 300 nm.

Improved determination of particulate absorption from combined filter pad and PSICAM measurements.

Filter pad light absorption measurements are subject to two major sources of experimental uncertainty: the so-called pathlength amplification factor, β, and scattering offsets, o, for which previous null-correction approaches are limited by recent observations of non-zero absorption in the near infrared (NIR). A new filter pad absorption correction method is presented here which uses linear regression against point-source integrating cavity absorption meter (PSICAM) absorption data to simultaneously resolve both β and the scattering offset. The PSICAM has previously been shown to provide accurate absorption data, even in highly scattering waters.

New E-beam-initiated hyaluronan acrylate cryogels support growth and matrix deposition by dermal fibroblasts.

Cryogels made of components of natural extracellular matrix components are potent biomaterials for bioengineering and regenerative medicine. Human dermal fibroblasts are key cells for tissue replacement during wound healing. Thus, any biomaterial for wound healing applications should enable growth, differentiation and matrix synthesis by these cells.

Glycyrrhizic Acid Decreases Gentamicin-Resistance in Vancomycin-Resistant Enterococci.

The resistance of commensal bacteria against first and second line antibiotics has reached an alarming level in many parts of the world and endangers the effective treatment of infectious diseases. Particularly vancomycin-resistant represents an increasing clinical problem in the treatment of infectious diseases and hinders adequate antibiotic stewardship. In consideration of the lack of novel antibiotic compounds, the development of resistance-modifying agents, however, can mitigate the spread of bacterial drug resistance and might possibly extend the useful application indices of an existing licensed antibiotic.

Micro- and nano-environments of C sequestration in soil: a multi-elemental STXM-NEXAFS assessment of black C and organomineral associations.

Black C is an essential component of the terrestrial C pool and its formation is often credited as a CO(2) sink by transferring the fast-cycling C from the atmosphere-biosphere system into slower cycling C in the geosphere. This study is the first multi-element K- (C, N, Ca, Fe, Al and Si) soft-X-ray STXM-NEXAFS investigation conducted at a submicron-scale spatial resolution specifically targeting black C and its interaction with the mineral and non-black C organic matter in the organomineral assemblage. The STXM-NEXAFS micrographs and spectra demonstrated that pyrogenic C was dominated by quinoide, aromatic, phenol, ketone, alcohol, carboxylic and hydroxylated- and ether-linked C species.

In-line monitoring of the thickness of printed layers by near-infrared (NIR) spectroscopy at a printing press.

In this work, it is demonstrated that the coating weight of printed layers can be determined in-line in a running printing press by near-infrared (NIR) reflection spectroscopy assisted by chemometric methods. Three different unpigmented lacquer systems, i.e.

Simultaneous in-line monitoring of the conversion and the coating thickness in UV-cured acrylate coatings by near-infrared reflection spectroscopy.

Near-infrared (NIR) reflection spectroscopy was used for in-line analysis of the conversion and the coating thickness (5-20 μm) of UV-cured clear and pigmented acrylate coatings. The quantitative evaluation of the recorded spectra was carried out by partial least-squares (PLS) regression, in particular with the PLS2 algorithm, which allows simultaneous prediction of both parameters. The efficiency of this method was investigated in roll coating experiments at line speeds up to 100 m min(-1).

Monitoring of the thickness of ultraviolet-cured pigmented coatings and printed layers by near-infrared spectroscopy.

Near-infrared (NIR) reflection spectroscopy was used for the determination of the thickness or the coating weight, respectively, of white-pigmented acrylic coatings and layers of printing inks. The thickness of coatings was studied in the range from 5 to 60 microm, whereas the coating weights of the printed layers covered a range between 1 to 5 g m(-2). Quantitative analysis of the spectral data relied on partial least squares (PLS) regression.

Determination of the thickness of silazane-based SiO(x) coatings in the submicrometer range by near-infrared reflection spectroscopy.

The thickness of thin silica layers in the submicrometer range, i.e., between about 150 and 700 nm, was determined by near-infrared (NIR) reflection spectroscopy.

Association of inflammatory bowel disease with indicators for childhood antigen and infection exposure.

Background And Aims: Genetic susceptibility plays an important role in the predisposition to inflammatory bowel disease (IBD), but genetics alone cannot explain the six- to eightfold rise in incidence accompanying postwar socioeconomic changes in developed countries. It is presently unclear how environmental factors either trigger or modify the risk for and course of IBD in the presence of genetic susceptibility.

Patients And Methods: We evaluated 2,351 consecutive responses from IBD patients and from 3,364 of their unaffected first-degree relatives (parents/siblings) who completed a multi-item questionnaire with their physicians as part of a study of IBD genetics.

Anticipation in inflammatory bowel disease: a phenomenon caused by an accumulation of confounders.

Inflammatory bowel disease (IBD) has a definite genetic component as documented by epidemiological and linkage evidence. It shows an earlier onset of disease in children of affected patients than in their parents. This has lead to speculations about genetic anticipation in this disorder.

Effect of sex hormones on the activities of hepatic alcohol-metabolizing enzymes in male rats.

In mature male rats both estradiol administration as well as castration had a striking suppressive effect on the hepatic activity of the microsomal ethanol-oxidizing system, whereas alcohol dehydrogenase activity was increased under these experimental conditions. The castration effects on the activities of the alcohol-metabolizing enzymes could be completely prevented by the administration of testosterone. Therefore, these results indicate the sex-dependent nature of the hepatic microsomal ethanol-oxidizing system and alcohol dehydrogenase.