On core and bar-core partitions

If s and t are relatively prime integers, J.B. Olsson proved in (J. Comb. Theory, Ser. A 116:733–740, 2009) that the s-core of a t-core partition is again a t-core partition, and that the s-bar-core of a t-bar-core partition is again a t-bar-core partition. Here generalised results are proved for partitions and bar partitions when the restriction that s and t be relatively prime is removed.     

Polyphenolic Profiling,Antioxidant, and Antimicrobial Activities Revealed the Quality and Adaptive Behavior of Viola Species,a Dietary Spice in the Himalayas

Background: Himalayan Viola species (Banksha) are traditionally important herbs with versatile therapeutic benefits such as antitussive, analgesic, antipyretic, antimalarial, anti-inflammatory, and anticancerous ones. The current investigation was focused on exploring polyphenolic profiles, antioxidant, and antimicrobial potentials of wild viola species at 15 gradient locations (375–1829 m). Methods: Morphological, physiochemical, and proximate analyses were carried out as per WHO guidelines for plant drug standardization. Total polyphenolic and flavonoid content were carried out using gallic acid and rutin equivalent. UPLC-DAD was used to profile the targeted polyphenols (gallic acid, vanillic acid, syringic acid, p-coumaric acid, ferulic acid, rutin, quercetin, luteolin, caffeic acid, and epicatechin). Similarly, all samples were screened for antioxidant and antimicrobial activity. Statistical analysis was used to correlate polyphenolic and targeted activities to assess Viola species adaptation behavior patterns. Results: Viola canescens (V. canescens) and Viola pilosa (V. pilosa) were found abundantly at their respective sites. Among flowers and leaves, flowers of V. canescens and V. pilosa showed higher total polyphenolic and flavonoid content (51.4 ± 1.13 mg GAE/g and 65.05 ± 0.85 mg RE/g, and 33.26 ± 0.62 mg GAE/g and 36.10 ± 1.41 mg RE/g, respectively). Furthermore, UPLC-DAD showed the uppermost content of p-coumaric acid in flowers and ferulic acid in leaves, while rutin was significant in both the tissues. Conclusions: The adaptive behavior of Viola species showed variability in morphological characters with the altitudes, while targeted polyphenols and activities were significant at mid-altitudes. This research helps in the selection of right chemotype for agrotechnological interventions and the development of nutraceutical products.     

Methyltrioxorhenium-catalyzed aerobic oxidative coupling of 2-naphthols to binaphthols

A variety of 2-naphthols have been selectively oxidized to their corresponding 1,1′-bi-2-naphthols in excellent yields with molecular oxygen using methyltrioxorhenium as catalyst.     

Cobalt phthalocyanine catalyzed aerobic oxidation of secondary alcohols: an efficient and simple synthesis of ketones

A variety of activated and non-activated secondary alcohols have been efficiently oxidized to their corresponding ketones in excellent yields with molecular oxygen using cobalt phthalocyanine as catalyst in the presence of powdered potassium hydroxide.     

Eine allgemeine, einfache und schonende Synthesemethode für Fluororganylborane

The fluorination of a number of alkyl- and arylchloro- and bromoboranes succeeds upon transhalogenation with lithium or potassium fluoride under mild reaction conditions in good yields.     

Cherenkov radiation spectrum

A new method is proposed for the construction of the theoretical Cherenkov spectrum. The expression representing the spectral energy distribution has the same form as the classical Frank-Tamm formula, but the square of the index of refraction is replaced by the real part of a dielectric function, which we interpret as a function characteristic of the polarized medium in the immediate vicinity of the passing charged particle.     

Temperature program optimization in a nonisothermal experiment

The optimum temperature program has been determined for a system of independent first-order reactions, which is best in the sense of an identifiability decomposition criterion. Analytic expressions are derived for the optimum programs for the case of two reactions. A computer algorithm is described for the case of any number of reactions. It is suggested that one should use programs combining linear heating with isothermal operation.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 23, No. 6, pp. 716–723, November–December, 1987.     

Chemical activation of cytochrome c proteins via crown ether complexation: cold-active synzymes for enantiomer-selective sulfoxide oxidation in methanol

Supramolecular complexation with 18-crown-6 significantly converted catalytically inactive cytochrome c (biological form) to catalytically active synzyme (artificial form). Although a family of cytochrome c proteins does not work as enzymes in nature, crown ether complexation modified their heme coordination structures and functionally activated them to promote the asymmetric oxidation of racemic sulfoxides at low temperature. Horse heart, pigeon breast, and yeast cytochrome c proteins were demonstrated to form supramolecular complexes with 18-crown-6 in methanol, which effectively oxidized (S)-isomers of naphthyl methyl sulfoxide, methyl tolyl sulfoxide, isopropyl phenyl sulfoxide, benzyl methyl sulfoxide, and 4-methylsulfenyl acetophenone at -40 degrees C. Because horse heart and pigeon breast cytochromes c exhibited more efficient and higher enantiomer-selective activities than yeast cytochrome c, a proper combination of cytochrome c and crown ether offers a new class of cold-active synzymes promoting nonbiological asymmetric oxidation.     

Magnetic permeability spectra of nanosized powders of hexaferrites

A study is made of the magnetic permeability spectra of ultrafine W-hexaferrites powders, obtained by mechanical activation. It is demonstrated that natural ferromagnetic resonance frequency can be controlled by mechanochemical treatment. The physical mechanisms of spectrum evolution are discussed.