Histamine-bound magnesium porphyrins: diverse coordination modes, inhibitory role in photodegradation of chlorophyll and antioxidant activity.

The neurotransmitter histamine exists in two isomeric forms and could be an interesting ligand due to three nitrogen atoms with the possibility of binding to metals in different ways besides its crucial role in biological systems. However, no metal-histamine interaction is known in the literature. Therefore, two histamine-bound magnesium porphyrins [MgT(4-Cl)PP(hist)] 1 and [MgT(4-Br)PP(hist)] 2 have been synthesized and structurally characterized.

Experimental Study to Evaluate the Wear Performance of UHMWPE and XLPE Material for Orthopedics Application.

The main objective of this study is to perform an abrasive wear resistance study of UMHWPE and XLPE by using different grades of abrasive paper (grade 100 (190 µm), grade 220 (50 µm), and grade 400 (40 µm)) with minor (10 N) and major (15 N) loading conditions. In this article, wear performance of the UMHWPE and XLPE materials compared to the bio-tribological data as reported earlier in the clinical studies has been investigated. The experimental result shows that the loss of materials for the XLPE was much higher than the UHMWPE under similar loading conditions.

Performance Evaluation of Different Coating Materials in Delamination for Micro-Milling Applications on High-Speed Steel Substrate.

The objective of the present work is to carry out analytical and finite element analysis for commonly used coating materials for micro-milling applications on high-speed steel substrate and evaluate the effects of different parameters. Four different coating materials were selected for micro-milling applications: titanium nitride (TiN), diamond-like carbon (DLC), aluminium titanium nitride (AlTiN) and titanium silicon nitride (TiSiN). A 3D finite element model of coating and substrate assembly was developed in Abaqus to find the Hertzian normal stress when subjected to normal load of 4 N, applied with the help of a rigid ball.

Iron and zinc porphyrin linked MoO(dithiolene) complexes in relevance to electron transfer between Mo-cofactor and cytochrome in sulfite oxidase.

Oxo-molybdenum (dithiolene) complexes covalently linked individually to iron and zinc porphyrin have been synthesized to show an electron transfer between the two metal centres in relevance to electron transfer from Mo-cofactor to cytochrome domains in the oxidative half of the catalytic cycle of native sulfite oxidase. This association has been investigated by electrochemical, EPR measurement and X-ray absorbance spectroscopy techniques.

Zinc protoporphyrin-trimethylamine-N-oxide complex involves cholesterol oxidation causing atherosclerosis.

Metabolism of food protein by gut microbes produce trimethylamine which on oxidation by hepatic flavin-containing monooxygenases is transformed to trimethylamine-N-oxide (TMAO). TMAO has recently been implicated as a biomarker for atherosclerosis. TMAO, as (CH)N-O), is ionic and so a hydrophilic molecule that is freely available in blood plasma.