Molecular Energotropic and Cellular Mechanism of the Radioprotective Action of Sulfur-Containing Biphenolic Dibasic Acids under Conditions of Lethal γ-Irradiation

Fibers composed of different types of collagen cannot be differentiated by conventional electron microscopic stains. We are developing staining procedures aimed at identifying collagen fibers of different types.Pt(Gly-L-Met)Cl binds specifically to sulfur-containing amino acids. Different collagens have methionine (met) residues at somewhat different positions. A good correspondence has been reported between known met positions and Pt(GLM) bands in rat Type I SLS (collagen aggregates in which molecules lie adjacent to each other in exact register). We have confirmed this relationship in Type III collagen SLS (Fig. 1).

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Signal-regulated oxidation of proteins via MICAL

Biochemical Society Transactions ◽

10.1042/bst20190866 ◽

2020 ◽

Vol 48 (2) ◽

pp. 613-620

Author(s):

Clara Ortegón Salas ◽

Katharina Schneider ◽

Christopher Horst Lillig ◽

Manuela Gellert

Keyword(s):

Signal Transduction ◽

Hydrogen Peroxide ◽

Cell Death ◽

Redox Regulation ◽

Signal Transduction Pathways ◽

Cellular Functions ◽

Intracellular Signals ◽

Amino Acid Side Chains ◽

Specific Receptors ◽

Sulfur Containing

Processing of and responding to various signals is an essential cellular function that influences survival, homeostasis, development, and cell death. Extra- or intracellular signals are perceived via specific receptors and transduced in a particular signalling pathway that results in a precise response. Reversible post-translational redox modifications of cysteinyl and methionyl residues have been characterised in countless signal transduction pathways. Due to the low reactivity of most sulfur-containing amino acid side chains with hydrogen peroxide, for instance, and also to ensure specificity, redox signalling requires catalysis, just like phosphorylation signalling requires kinases and phosphatases. While reducing enzymes of both cysteinyl- and methionyl-derivates have been characterised in great detail before, the discovery and characterisation of MICAL proteins evinced the first examples of specific oxidases in signal transduction. This article provides an overview of the functions of MICAL proteins in the redox regulation of cellular functions.

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Modification of optical properties of PC-PBT/Cr2O3 and PC-PBT/CdS nanocomposites by gamma irradiation

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020200201 ◽

2020 ◽

Vol 92 (2) ◽

pp. 20402

Author(s):

Kaoutar Benthami ◽

Mai ME. Barakat ◽

Samir A. Nouh

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Band Gap ◽

Color Difference ◽

Band Gap Energy ◽

Polybutylene Terephthalate ◽

Γ Irradiation ◽

Gap Energy ◽

Vis Spectroscopy ◽

Oxygen Atoms

Nanocomposite (NCP) films of polycarbonate-polybutylene terephthalate (PC-PBT) blend as a host material to Cr2O3 and CdS nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Samples from the PC-PBT/Cr2O3 and PC-PBT/CdS NCPs were irradiated using different doses (20–110 kGy) of γ radiation. The induced modifications in the optical properties of the γ irradiated NCPs have been studied as a function of γ dose using UV Vis spectroscopy and CIE color difference method. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the NCP films and to identify the types of electronic transition. The value of optical band gap energy of PC-PBT/Cr2O3 NCP was reduced from 3.23 to 3.06 upon γ irradiation up to 110 kGy, while it decreased from 4.26 to 4.14 eV for PC-PBT/CdS NCP, indicating the growth of disordered phase in both NCPs. This was accompanied by a rise in the refractive index for both the PC-PBT/Cr2O3 and PC-PBT/CdS NCP films, leading to an enhancement in their isotropic nature. The Cr2O3 NPs were found to be more effective in changing the band gap energy and refractive index due to the presence of excess oxygen atoms that help with the oxygen atoms of the carbonyl group in increasing the chance of covalent bonds formation between the NPs and the PC-PBT blend. Moreover, the color intensity, ΔE has been computed; results show that both the two synthesized NCPs have a response to color alteration by γ irradiation, but the PC-PBT/Cr2O3 has a more response since the values of ΔE achieved a significant color difference >5 which is an acceptable match in commercial reproduction on printing presses. According to the resulting enhancement in the optical characteristics of the developed NCPs, they can be a suitable candidate as activate materials in optoelectronic devices, or shielding sheets for solar cells.

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Effects of γ-Irradiation and Ageing on Surface and Catalytic Properties of nano-sized CuO/MgO System towards dehydrogenation and condensation reactions

10.3390/ecsoc-13-00177 ◽

2009 ◽

Author(s):

Sahar A. El-Molla ◽

Marwa M. Ibrahim ◽

Sahar A. Ismail

Keyword(s):

Catalytic Properties ◽

Γ Irradiation ◽

Condensation Reactions

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The Correlation of Adhesion Strength with Barrier Structure in Cu Metallization

MRS Proceedings ◽

10.1557/proc-766-e.3.5 ◽

2003 ◽

Vol 766 ◽

Author(s):

A. Sekiguchi ◽

J. Koike ◽

K. Ueoka ◽

J. Ye ◽

H. Okamura ◽

...

Keyword(s):

Thin Films ◽

Adhesion Strength ◽

Nitrogen Concentration ◽

Scratch Test ◽

Barrier Structure ◽

Barrier Layers ◽

Cu Metallization ◽

Microstructure Observation ◽

Sputter Deposited ◽

Sulfur Containing

AbstractAdhesion strength in sputter-deposited Cu thin films on various types of barrier layers was investigated by scratch test. The barrier layers were Ta1-xNx with varied nitrogen concentration of 0, 0.2, 0.3, and 0.5. Microstructure observation by TEM indicated that each layer consists of mixed phases of β;-Ta, bcc-TaN0.1, hexagonal-TaN, and fcc-TaN, depending on the nitrogen concentration. A sulfur- containing amorphous phase was also present discontinuously at the Cu/barrier interfaces in all samples. Scratch test showed that delamination occurred at the Cu/barrier interface and that the overall adhesion strength increased with increasing the nitrogen concentration. A good correlation was found between the measured adhesion strength and the composing phases in the barrier layer.

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Thioether-Facilitated Iridium-Catalyzed Hydrosilylation of Steric 1,1-Disubstituted Olefins

10.26434/chemrxiv.9859103.v1 ◽

2019 ◽

Author(s):

Shengtao Ding

Keyword(s):

Side Chains ◽

Feasible Method ◽

Iridium Catalysis ◽

Efficient Strategy ◽

Terminal Alkenes ◽

And Control ◽

Sulfur Containing ◽

Organosilicon Polymers

One facile and efficient strategy for the hydrosilylation of steric 1,1-disubstituted terminal alkenes is demonstrated. Investigations on substrate scope and control experiments revealed the necessity of thioether in promoting this process under a simple iridium catalysis system. This convenient and feasible method is expected to be useful in the synthesis of sulfur-containing organosilicon polymers with different side-chains.

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