B-O-4

In the present work, a hydrogen-free one step catalytic fractionation of woody biomass using commercial b-zeolite as catalyst in a flow-through reactor was carried out, Birch, spruce and walnut shells were compared as lignocellulosic feedstocks. b-zeolite acts as a bifunctional catalyst, which prevents lignin repolymerization due to its size-selective properties and also cleaves b-O-4 lignin intralinkage while stabilizing reactive intermediates A rate limiting step analysis using different reactor configurations revealed a mixed regime where the rates of both solvolytic delignification and zeolite-catalyzed depolymerization/dehydration affect the net rate of aromatic monomer production...

It is well known that during oxidative depolymerization of lignin in aqueous alkaline medium using molecular oxygen as oxidant, the highly functionalized primary phenolic monomers are not stable products due to various and not fully identifying secondary reaction mechanisms. However, a better understanding of the mechanisms responsible for instability of the main part of the products of interest derived from lignin is of much interest. The evaluation of their individual reactivity and degradation under oxidative conditions should significantly help to find a better way to valorise the lignin polymer and to maximize the yields of target value-added products...

With the exception to Salmonella enterica serotype Typhimurium and S. Enteritidis (serogroups B [O:4] and D [O:9], respectively), there have been very few studies conducted on the respiratory tract as route of infection in chickens with salmonellae from serogroup C1 (O:6,7) . Therefore, the purpose of this present study was to determine the potential organ invasion by Salmonella enterica serotype Potsdam (SP), S. Mbandaka (SM), and S. Infantis (SI) from serogroup C1 (O:6,7) and compare its characteristics from those of S...

Salmonella enterica serovar Gallinarum is a nonmotile host-adapted Salmonella that causes fowl typhoid (FT), and an outbreak of FT is characterized by anorexia, greenish-yellow diarrhea, paleness, and sudden death with high mortality in poultry. To control and treat FT in commercial chickens, fluoroquinolones are widely used in Korea. This study aimed to investigate the genetic characteristics of fluoroquinolone-resistant Salmonella Gallinarum isolates from 2014-18 from chicken in Korea. A total of 35 ciprofloxacin (CIP)-resistant Salmonella Gallinarum was tested, and 22 (62...

The depolymerisation of the biopolymer lignin can give pure aromatic monomers but selective catalytic approaches remain scarce. Here, an approach was re-routed to deliver an unusual phenolic monomer. This monomer's instability proved challenging but a degradation study identified strategies to overcome this. Heterocycles and a useful synthetic intermediate were prepared. The range of aromatics available from the b-O-4 unit in lignin was extended.

The crystal structure of four Pb apatite samples, Pb5 (BO4 )3 Cl, was refined with synchrotron high-resolution powder X-ray diffraction data, Rietveld refinements, space group P63 /m and Z = 2. For this isotypic series, B = P5+ is pyromorphite, B = As5+ is mimetite and B = V5+ is vanadinite. The ionic radius for As5+ (0.355 Å) is similar to that of V5+ (0.335 Å), and this is twice as large as that for P5+ (0.170 Å). However, the c unit-cell parameter for mimetite is surprisingly different from that of vanadinite, although their unit-cell volumes, V, are almost equal to each other...

Nontyphoidal Salmonella (NTS; i.e., Salmonella enterica organisms that do not cause typhoid or paratyphoid) are responsible for 94 million infections and 155,000 deaths worldwide annually, 86% of which are estimated to be foodborne. Although more than 50 serogroups and 2,600 serovars have been described, not all Salmonella serovars cause disease in humans and animals. Efforts are being made to develop NTS vaccines, with most approaches eliciting protection against serovars Typhimurium and Enteritidis (serogroups B [O:4] and D [O:9], respectively), as they are widely considered the most prevalent...

Colonies of the Salmonella strains usually show a smooth (S) character. Therefore, Salmonella strains producing mucoid colony are very rarely encountered in the literature. Identification of the mucoid Salmonella strains to the species level is difficult via conventional methods, since the mucus layer does not allow the bacterium to respond to the antigenic reactions. In this study we aimed to emphasize the identification of Salmonella serotypes by the polymerase chain reaction (PCR) when rough (R) or mucoid (M) Salmonella isolates are encountered in the laboratory...

Gallium boron phosphate, (Ga(0.71)B(0.29))PO(4), was synthesized by a high-temperature solid-state reaction method. The crystal structure is isostructural with the tetra-gonal high-cristobalite structure with space group P which is built from alternating Ga(B)O(4) and PO(4) tetra-hedra inter-connected by sharing the common O-atom vertices, resulting in a three-dimensional structure with two-dimensional six-membered-ring tunnels running along the a and b axes.

Experimental structure functions for (Na(2)O)(0.35) [(P(2)O(5))(1 - x)(B(2)O(3))(x)](0.65) glasses, where x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0, have been measured by high-energy x-ray diffraction up to wavevectors of 28 Å( - 1) to obtain atomic pair distribution functions with high real space resolution. The experimental diffraction data have been used to guide constrained reverse Monte Carlo simulations of the three-dimensional structure of the glasses. The resulting models show that the glasses exhibit a very complex atomic-scale structure that evolves from an assembly of chains of corner shared P(O)(4) tetrahedra for x = 0 to a network of B(O)(4) tetrahedra and planar B(O)(3) units for x = 1...

In a series of sodium aluminoborate glasses, we have applied triple-quantum magic-angle spinning (3QMAS) 17O NMR to obtain high-resolution information about the connections among various network structural units, to explore the mixing of aluminum and boron species. Oxygen-17 3QMAS spectra reveal changes in connectivities between AlO4 ([4]Al), AlO5 and AlO6 ([5,6]Al), BO3 ([3]B) and BO4 ([4]B) units, by quantifying populations of bridging oxygens such as Al-O-Al, Al-O-B and B-O-B and of non-bridging oxygens...

No abstract text is available yet for this article.