Synthesis of solamin type mono-THF acetogenins using cross-metathesis

The total synthesis of mono-THF acetogenins, cis-solamin A and B, and reticulatacin, was accomplished starting with muricatacin. The backbone of the mono-THF acetogenins was constructed by olefin cross-metathesis between the tetrahydrofuran moiety and γ-lactone moiety. An enzymatic kinetic transesterification procedure was successfully applied to the synthesis of an optically pure γ-lactone moiety. Notably, cis-THF compounds were obtained without using protective groups.     

Polyphenols and Their Effects on Muscle Atrophy and Muscle Health

Skeletal muscle atrophy is the decrease in muscle mass and strength caused by reduced protein synthesis/accelerated protein degradation. Various conditions, such as denervation, disuse, aging, chronic diseases, heart disease, obstructive lung disease, diabetes, renal failure, AIDS, sepsis, cancer, and steroidal medications, can cause muscle atrophy. Mechanistically, inflammation, oxidative stress, and mitochondrial dysfunction are among the major contributors to muscle atrophy, by modulating signaling pathways that regulate muscle homeostasis. To prevent muscle catabolism and enhance muscle anabolism, several natural and synthetic compounds have been investigated. Recently, polyphenols (i.e., natural phytochemicals) have received extensive attention regarding their effect on muscle atrophy because of their potent antioxidant and anti-inflammatory properties. Numerous in vitro and in vivo studies have reported polyphenols as strongly effective bioactive molecules that attenuate muscle atrophy and enhance muscle health. This review describes polyphenols as promising bioactive molecules that impede muscle atrophy induced by various proatrophic factors. The effects of each class/subclass of polyphenolic compounds regarding protection against the muscle disorders induced by various pathological/physiological factors are summarized in tabular form and discussed. Although considerable variations in antiatrophic potencies and mechanisms were observed among structurally diverse polyphenolic compounds, they are vital factors to be considered in muscle atrophy prevention strategies.     

InP heteroepitaxy on Si substrates in In-PH3-HC1-H2 systems

Heteroepitaxial growth of InP on Si in an In-PH₃-HC1-H₂ system is demonstrated. Injecting hydrogen chloride into the growth ambiance prevents indium droplets from precipitating and enables the growth of a featureless InP buffer layer. Morphologies of InP/Si grown by the two-step method vary from island growth at 650°C to continuous-layer growth at 550°C. The temperature required for growing continuous InP layers depends on the crystallinity of the InP under-layer on the Si. High-quality InP layers with 650 arc sec full width at half maximum of double X-ray diffraction are obtained by using a three-step growth method.     

Quantum wire lasers with high uniformity formed by cleaved-edge overgrowth with growth-interrupt anneal

High-quality T-shaped quantum wire lasers are fabricated by cleaved-edge overgrowth with the molecular beam epitaxy on the interface improved by a growth-interrupt high-temperature anneal. Micro-photoluminescence (PL) and PL excitation spectroscopy reveals unprecedented high quality of the wires, and structures of one-dimensional (1D) free excitons and 1D continuum states. At high pumping levels, PL evolves from a sharp free exciton peak via a biexciton peak to a red-shifted broad band. Lasing has been achieved with low lasing threshold. The lasing energy is on the red-shifted broad band and is about 5 meV below the free exciton. The observed shift excludes free excitons in lasing, and suggests contribution of highly Coulomb-correlated electron-hole plasma.     

A theory of the anomalous heat capacity and thermal expansion of nematic liquid crystals above the clearing point

the anomalous part of the specific heat capacity and hte isobaric thermal expansion coefficient of nematic liquid crystals above the transition point are calculated on the basis of the continuum fluctuation theory of de Gennes.     

Unimodular Triangulations and Coverings of Configurations Arising from Root Systems

Existence of a regular unimodular triangulation of the configuration , where ⁺ is the collection of the positive roots of a root system and where (0, 0,...,0 ) is the origin of , will be shown for = B _n , C _n , D _n and BC _n . Moreover, existence of a unimodular covering of a certain subconfiguration of the configuration A _n+1 ⁺ will be studied.     

Enhanced Raman Scattering from Vibro‐Polariton Hybrid States

Ground‐state molecular vibrations can be hybridized through strong coupling with the vacuum field of a cavity optical mode in the infrared region, leading to the formation of two new coherent vibro‐polariton states. The spontaneous Raman scattering from such hybridized light–matter states was studied, showing that the collective Rabi splitting occurs at the level of a single selected bond. Moreover, the coherent nature of the vibro‐polariton states boosts the Raman scattering cross‐section by two to three orders of magnitude, revealing a new enhancement mechanism as a result of vibrational strong coupling. This observation has fundamental consequences for the understanding of light‐molecule strong coupling and for molecular science.