Bacteroides acidifaciens: Linking dietary fiber to liver health.

While innumerous associative microbiome studies have been published, mechanistic links between the microbiome and host physiology remain much scarcer. In Cell Host & Microbe, Shen et al. report the effect of soluble dietary fibers in alcohol-related liver disease.

Anti-Fatigue Glasses Based on Microprisms for Preventing Eyestrain.

Although microprisms have become an important medical means of strabismus treatment, related research concerning the design, fabrication, and testing of microprismatic glasses for preventing eyestrain has rarely been reported. In this study, the structure of microprismatic glasses for preventing eyestrain related to using electronic monitors, including computers and mobile phones, is introduced. A designing theory of anti-fatigue glasses with microprisms is developed.

Structure of microprismatic Fresnel lenses for creating uniform focal images.

Flat Fresnel lenses are known to form a point image in the focal plane. However, several practical applications require transforming lens to concentrate a parallel light beam into a uniformly illuminated light circle. We previously proposed a novel algorithm for simulating such a transforming Fresnel concentrator.

Synthesis of purines and adenines containing the hexafluoroisopropyl group.

Several new derivatives of adenine, purine, and theophylline containing the (CF)CH group connected to a nitrogen atom of the imidazole ring were prepared by the reaction of 2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithietane () with the corresponding substrates, resulting in the selective alkylation of one of the nitrogen atoms of the imidazole ring. The reaction proceeds under mild conditions in a polar solvent, giving the alkylated products in 47-78% yield. While for purine and 4- and 5-azabenzimidazole, the reaction led to a mixture of two isomers, the reaction of adenine and the corresponding 2-fluoro derivative was regioselective, resulting in the formation of only one isomer in each case.

Diels-Alder reactions of "in situ" generated perfluorinated thioketones.

A simple and general procedure for the preparation of Diels-Alder adducts of perfluorinated thioketones and various dienes is reported. The corresponding Diels-Alder adducts were prepared in 30-78% yield under mild conditions via a reaction of a mixture of fluoroolefins, sulfur, diene and CsF as a catalyst.

Reaction of 2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithiethane with N-vinyl compounds.

The reaction of hexafluorothioacetone dimer (2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithiethane, 1) with vinylamides leads to the rapid formation of [2 + 2] cycloadducts: 4-amino-2,2-bis(trifluoromethyl)thietanes. The reaction proceeds in polar solvents (DMF, DMSO) in the absence of a catalyst at elevated temperature producing the corresponding cycloadducts in 47-86% yield. The reaction of N-vinylimidazole unexpectedly led to the formation of the corresponding 1-(hexafluoroisopropyl)-3-vinyl-1,3-dihydro-2H-imidazole-2-thione (5).

Echelette optical low-pass filter as a Bangerter filter for diagnosis and treatment of amblyopia and diplopia.

This paper presents a new echelette optical low-pass filter that serves as a Bangerter filter (BF) for diagnosis and treatment of amblyopia and diplopia. Theoretical analysis and experimental measurements showed that echelette BFs have several advantages over the modern BFs used in medicine. Four echelette BFs with different grating periods and one BF were manufactured, and image blurring in an optical visual system with an echelette BF was experimentally investigated.

Acid catalyzed cyclodimerization of 2,2-bis(trifluoromethyl)-4-alkoxy-oxetanes and -thietanes. Synthesis of 2,2,6,6-tetrakis(trifluoromethyl)-4,8-dialkoxy-1,5-dioxocanes and 3,3,7,7-tetrakis(trifluoromethyl)-9-oxa-2,6-dithia-bicyclo[3.3.1]nonane.

Treatment of 2,2-bis(trifluoromethyl)-4-R-oxetanes (R = C₂H₅O, n-C₃H₇O, n-C₄H₉O) with BF₃.OEt₂ in CH₂Cl₂ solvent results in spontaneous electrophilic [4 + 4] cyclodimerization with the formation of the corresponding 2,2,6,6-tetrakis(trifluoromethyl)-4,8-dialkoxy-1,5-dioxocanes, isolated in 31-42% yield. The structures of two products (R = C₂H₅O and n-C₃H₇O) were established by single crystal X-ray diffraction.

The first perfluoroacetylacetonate metal complexes: as unexpectedly robust as tricky to make.

First metal complexes containing the perfluoroacetylacetonato ligand have been prepared by the reaction of anhydrous Ln(OAc)3 (Ln = Eu, Tb, Tm) with heptafluoroacetylacetone, optionally in the presence of other ligands Ph3PO, bpy, and PyO.

Selective Reduction of Halopolyfluorocarbons by Organosilicon Hydrides.

It is demonstrated that silicon hydrides can be used for reduction of polyfluorinated halocarbons. For example, the reaction between CF(3)CCl(2)F and excess triethylsilane, catalyzed by benzoyl peroxide, leads to the formation of a mixture containing CF(3)CHClF (major), CF(3)CH(2)F, and ClSi(C(2)H(5))(3). On the other hand, the reaction of chlorofluoroalkanes, containing an internal -CCl(2)- group readily proceeds with reduction of both chlorines, leading to compounds such as (CF(3))(2)CH(2) and CF(3)CH(2)C(2)F(5).

Selective Epoxidation of Olefins by Perfluoro-cis-2,3-dialkyloxaziridines(1).

Alkyl-substituted olefins are epoxidized by perfluoro-cis-2,3-dialkyloxaziridines under particularly mild conditions. Electron deficient substrates (e.g.