Three-dimensional effects on the linear adiabatic molecular wavefunctions in the H + H2 system

The adiabatic molecular wavefunctions in the H + H₂ system are obtained in one dimension by solving the double-well potential problem. In three dimensions, the corresponding linear adiabatic molecular wavefunctions are obtained. A comparison between these wavefunctions clearly suggests that the probability of reaction is smaller in three dimensions.     

Tris(4,7-dihydroxy-1,10-phenanthroline)iron(II) as a low-potential oxidation-reduction indicator: determination of hydrosulphite

The formal reduction potential of the tris(4,7-dihydroxy-1,10-phenanthroline)iron(III,II) couple is -0.06 V in the pH range 10-13, not -0.11 V as reported earlier. The couple forms an excellent visual oxidation-reduction indicator for the titration of sodium hydrosulphite with potassium ferricyanide in alkaline solution.     

Displacement affinity chromatography of protein phosphatase one (PP1) complexes

Background  

Protein phosphatase one (PP1) is a ubiquitously expressed, highly conserved protein phosphatase that dephosphorylates target protein serine and threonine residues. PP1 is localized to its site of action by interacting with targeting or regulatory proteins, a majority of which contains a primary docking site referred to as the RVXF/W motif.     

Detection of heteroplasmy in individual mitochondrial particles

Mitochondrial DNA (mtDNA) mutations have been associated with disease and aging. Since each cell has thousands of mtDNA copies, clustered into nucleoids of five to ten mtDNA molecules each, determining the effects of a given mtDNA mutation and their connection with disease phenotype is not straightforward. It has been postulated that heteroplasmy (coexistence of mutated and wild-type DNA) follows simple probability rules dictated by the random distribution of mtDNA molecules at the nucleoid level. This model has been used to explain how mutation levels correlate with the onset of disease phenotype and loss of cellular function. Nonetheless, experimental evidence of heteroplasmy at the nucleoid level is scarce. Here, we report a new method to determine heteroplasmy of individual mitochondrial particles containing one or more nucleoids. The method uses capillary cytometry with laser-induced fluorescence detection to detect individual mitochondrial particles stained with PicoGreen, which makes it possible to quantify the mtDNA copy number of each particle. After detection, one or more particles are collected into polymerase chain reaction (PCR) wells and then subjected to real-time multiplexed PCR amplification. This PCR strategy is suitable to obtain the relative abundance of mutated and wild-type mtDNA. The results obtained here indicate that individual mitochondrial particles and nucleoids contained within these particles are not heteroplasmic. The results presented here suggest that current models of mtDNA segregation and distribution (i.e., heteroplasmic nucleoids) need further consideration.     

Effective Tuning of Ketocyanine Derivatives through Acceptor Substitution

A series of ketocyanine derivatives possessing bis(diarylamino)fluorenyl donors and variable acceptors installed at the bridging carbon atom were synthesized to investigate how the electronic structure of the dye can be systemically tuned through stabilization of the cyanine‐like character of the donor by increasing the acceptor strength. Analysis of the ¹H NMR spectra indicates that the “charge‐separated” species dominates in these dyes, given that carbons possessing a positive or negative charge in the resonance structures of this state purposefully shift downfield or upfield, respectively, depending on the strength of the acceptor moiety. In DAA‐Fl‐PI, the acceptor strength and the gain of acceptor aromaticity indicates a predisposition of the separated state, indicated by asymmetry in the ¹H NMR spectrum, as well as uneven distribution of the HOMO on the fluorenyl donor.     

Optical crystallographic properties of some sulfonamides and their diliturates

Summary The optical properties of sulfacetamide, sulfathalidine, Gantrisin, and Elkosin have been investigated. A series of dilituric acid salts of three of the above sulfonamides has been prepared and their melting points, analyses, and optical properties have been determined. The densities and molar refractions of the four sulfonamides and of three of their diliturate salts have been reported.

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Zusammenfassung Die optischen Eigenschaften von Sulfathalidin (saures Phthalylsulfathiazol), Sulfacetamid, Gantrisin (3,4-Dimethyl-5-sulfanilamidoisoxazol) und Elkosin (6-Sulfanilamido-2,4-dimethylpyrimidin) wurden untersucht. Von den drei letztgenannten Sulfonamiden wurden die Diliturate (5-Nitrobarbiturate) hergestellt und zur Bestimmung des Schmelzpunktes und der optischen Eigenschaften verwendet. Die Dichten und Molekularrefraktionen der vier genannten Sulfonamide und der drei Diliturate werden mitgeteilt.

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Résumé Recherches sur les propriétés optiques de la «Sulfathalidine» (Phtalylsulfathiazol acide), de la sulfacetamide, de la «Gantrisine» (3,4-diméthyl-5-sulfanilamidoisoxazol) et de «l'Elkosine» (6-sulfanilamido-2,4-diméthylpyrimidine). Préparation des diliturates (5-nitrobarbiturate) des trois dernières sulfamides pour la détermination de leurs points de fusion et de leurs propriétés optiques. Publication des densités et des réfractions moléculaires des quatre sulfamides et des trois diliturates.