The review of versatile application of collagen

This review reports recent advances in the versatile application of collagen. Collagen materials have attracted great attention because they exhibit properties required in cosmetic preparations, in the biomedical field, and in the tanning industry leading to leather production. Herein, the structure and application of collagen are discussed in general, and detailed examples are also drawn from scientific literature and practical work. Copyright © 2016 John Wiley & Sons, Ltd.     

Gorenstein injective envelopes and covers over two sided noetherian rings

We prove that the class of Gorenstein injective modules is both enveloping and covering over a two sided noetherian ring such that the character modules of Gorenstein injective modules are Gorenstein flat. In the second part of the paper we consider the connection between the Gorenstein injective modules and the strongly cotorsion modules. We prove that when the ring R is commutative noetherian of finite Krull dimension, the class of Gorenstein injective modules coincides with that of strongly cotorsion modules if and only if the ring R is in fact Gorenstein.     

Combining size-exclusion chromatography and fully automated chip-based nanoelectrospray quadrupole time-of-flight tandem mass spectrometry for structural analysis of chondroitin/dermatan sulfate in human decorin

Chondroitin/dermatan sulfate (CS/DS) chain of decorin (DCN) from human skin fibroblasts (HSk) was released by reductive β-elimination reaction and digested with chondroitin AC I lyase. Enzymatic hydrolysis mixture of CS/DS chains was separated by size-exclusion chromatography (SEC). Collected octasaccharide fraction was subjected to fully automated chip-based nanoelectrospray (nanoESI) quadrupole time-of-flight (QTOF) MS and tandem MS (MS/MS). MS of human skin fibroblasts DCN CS/DS displayed a high complexity due to the large variety of glycoforms, which under chip-nanoESI MS readily ionized to form multiply charged ions. Except for the regularly tetrasulfated octasaccharide, the investigated fraction contained four additional octasaccharides of atypical sulfation status. Two new oversulfated glycoforms and two undersulfated species were identified. Remarkably, the series of decasaccharides discovered in the same SEC pool was found to encompass a trisulfated and a novel hexasulfated [4,5-Δ-GlcAGalNAc(IdoAGalNAc)?] species. MS/MS by collision-induced dissociation (CID) on the [M-4H]? ion corresponding to the previously not reported [4,5-Δ-GlcAGalNAc(IdoAGalNAc)?](5S) corroborated for a novel motif in which three N-acetylgalactosamine (GalNAc) moieties are monosulfated, 4,5-Δ-GlcA and the first IdoA from the non-reducing end bear one sulfate group each, while the second N-acetylgalactosamine from the reducing end is unsulfated.     

Characterizing the molecular order of phosphonic acid self-assembled monolayers on indium tin oxide surfaces

Self-assembled monolayers (SAMs) of alkanephosphonic acids with chain lengths between 8 and 18 carbon units were formed on thin films of indium tin oxide (ITO) sputter-deposited on silicon substrates with 400 nm thermally grown SiO(2). The silicon substrates, while not intended for use in near-IR or visible optics applications, do provide smooth surfaces that permit systematic engineering of grain size and surface roughness as a function of the sputter pressure. Argon sputter pressures from 4 to 20 mTorr show systematic changes in surface morphology ranging from smooth, micrometer-sized grain structures to <50 nm grains with 3× higher surface roughness. Near-edge X-ray absorption fine structure (NEXAFS) spectroscopy experiments are conducted for alkanephosphonic acids deposited on these wide range of ITO surfaces to evaluate the effects of these morphological features on monolayer ordering. Results indicate that long-chain SAMs are more highly ordered, and have a smaller tilt angle, than short-chain SAMs. Surprisingly, the 1-octadecyl phosphonic acids maintain their order as the lateral grain dimensions of the ITO surface shrink to ～50 nm. It is only when the ITO surface roughness becomes greater than the SAM chain length (～15 ?) that SAMs are observed to become relatively disordered.     

3-Methoxalylchromones--versatile reagents for the regioselective synthesis of functionalized 2,4'-dihydroxybenzophenones, potential UV-filters

The reaction of 1,3-bis-silyl enol ethers with 3-methoxalylchromones affords a great variety of functionalised 2,4'-dihydroxybenzophenones. These products are formed by a domino Michael/retro-Michael/Mukaiyama-aldol reaction. The synthesized compounds are promising candidates for the synthesis of the novel UV-A/B and UV-B filters.     

All-boron analogues of aromatic hydrocarbons: B17- and B18-

We have investigated the structural and electronic properties of the B(17)(-) and B(18)(-) clusters using photoelectron spectroscopy (PES) and ab initio calculations. The adiabatic electron detachment energies of B(17)(-) and B(18)(-) are measured to be 4.23 ± 0.02 and 3.53 ± 0.05 eV, respectively. Calculated electron detachment energies are compared with experimental data, confirming the presence of one planar C(2v) ((1)A(1)) isomer for B(17)(-) and two nearly isoenergetic quasi-planar C(3v) ((2)A(1)) and C(s) ((2)A') isomers for B(18)(-). The stability and planarity/quasi-planarity of B(17)(-) and B(18)(-) are ascribed to σ- and π-aromaticity. Chemical bonding analyses reveal that the nature of π-bonding in B(17)(-) and B(18)(-) is similar to that in the recently elucidated B(16)(2-) and B(19)(-) clusters, respectively. The planar B(17)(-) cluster can be considered as an all-boron analogue of naphthalene, whereas the π-bonding in the quasi-planar B(18)(-) is reminiscent of that in coronene.     

Phase diagram and dissolution studies of the fenofibrate–acetylsalicylic acid system

Enhancement of the dissolution rate of poorly soluble compounds through the formation of drug–drug eutectics was investigated using fenofibrate and acetylsalicylic acid. Solid–liquid equilibria in the system under study were investigated by differential scanning calorimetry (DSC). The phase diagram for the whole range of compositions was constructed. In addition, existence of a metastable polymorph of fenofibrate has been confirmed. The investigation has revealed that acetylsalicylic acid and fenofibrate form a simple eutectic mixture containing 0.958 mol fraction of fenofibrate at the eutectic point. Dissolution rate improvement of fenofibrate correlated with the phase diagram. The amount of fenofibrate released from the solid dispersions that contained fenofibrate as the eutectic mixture with acetylsalicylic acid was at least threefold higher compared to untreated fenofibrate.     

Solvent Effects on the piezochromism of molybdenum(IV) and tungsten(IV) anions [M(CN)3O(diimine)]−

Solvatochromism of the [Mo(CN)₃O(phen)]⁻ ion has been studied. Solvent effects on pressure dependence (up to 1.25 kbar) of wavelengths of maximum absorption for charge-transfer bands of several molybdenum(IV) and tungsten(IV) complexes, [M(CN)₃O(diimine)]⁻ (M = Mo or W), are described. The effects of applied pressure are larger for less polar unstructured solvents than for highly polar hydrogen-bonded solvents. This revised version was published online in June 2006 with corrections to the Cover Date.     

Study of Lipophilicity and Application of Selected Structural Descriptors in QSAR Analysis of Nicotinic Acid Derivatives. Investigations on RP18WF254 Plates. Part II

JPC – Journal of Planar Chromatography – Modern TLC - Nicotinic acid (NAC) and its derivatives methyl nicotinate (MN), ethyl nicotinate (EN), isopropyl nicotinate (IPN), butyl...     

Surface-templated formation of protein microfibril arrays.

Ordered arrays of collagen microfibrils form rapidly and spontaneously from a solution of monomers deposited onto a mica substrate. These arrays are well-ordered and apparently continuous over the entire substrate. Correlated atomic force microscope images and Laué diffraction patterns indicate that the protein alignment and microfibril formation is controlled by the crystal orientation of the mica substrate rather than fluid flow or drying effects. This surface-induced mechanism allows for immediate, robust, and reproducible pattern formation.