Achiral bent-core azo compounds: observation of photoinduced effects in an antiferroelectric tilted smectic mesophase

We report the synthesis and physical properties of four novel bent-core compounds, containing an azo linkage and alkyl terminal chains. It is found that, except for the lowest homologue, all the materials are liquid crystalline, exhibiting columnar or tilted polar smectic phases. In one of the compounds a reversible photoinduced variation of the spontaneous polarization of the antiferroelectric state was observed.     

Enhanced In Vitro Refolding of Soluble Human Glucocorticoid-Induced TNF Receptor-Related Ligand

The glucocorticoid-induced tumor necrosis factor receptor (GITR) is a member of the tumor necrosis factor receptor superfamily. Attachment of GITR to its ligand (GITRL) regulates diverse biological functions, including cell proliferation, differentiation, and survival. In this study, the extracellular region of human GITRL (hGITRL) was cloned, expressed, and purified. The coding sequence of the extracellular region of hGITRL was isolated from human brain cDNA and inserted in pET20b vector. The hGITRL was expressed in Escherichia coli BL21 (DE3) Star at 37 and 25 °C. The majority of the protein was found in inclusion bodies. We identified three important factors for efficient refolding of hGITRL: a ratio of GSH/GSSG, pH, and addition of polyethylene glycol. The renaturated protein was purified by Ni-NTA chromatography. The overall yield of the expression and refolding was higher than 50 mg/l E. coli culture grown at 37 °C. Size exclusion chromatography showed that hGITRL exists as mixture of various multimeric forms in solution. We tested the association of recombinant hGITRL with THP-1 and U937 cell lines and its activity to promote extracellular signal-regulated protein kinase phosphorylation. The results showed that the recombinant protein was biologically active.     

Correction to: Review on the recent progress in the preparation and stability of graphene-based nanofluids

Journal of Thermal Analysis and Calorimetry - Thermal behavior and smoke characteristics of glass/epoxy laminate and its foam core sandwich composite were comprehensively investigated using...     

Effect of mobile phase composition on the liquid chromatographic enantioseparation of bulky monoterpene‐based β‐amino acids by applying chiral stationary phases based on Cinchona alkaloid

Stereoselective HPLC separations of five sterically constrained monoterpene‐based 2‐aminocarboxylic acid enantiomers were carried out by using the newly developed zwitterionic chiral stationary phases Chiralpak ZWIX(+)? and ZWIX(?)? based on Cinchona alkaloid. In order to optimize the retention and enantioselectivity parameters, the ratio of the different organic solvents in the mobile phase and the nature of the acid and base additives (counter‐ and co‐ions) were systematically varied. The effects of structure variants of the analytes on the resolution were investigated. The elution sequence was determined in all cases and observed to be opposite on ZWIX(+)? and ZWIX(?)?.     

Studies in the Field of Pyridazine Compounds. X1. A Method for the Synthesis of 6-(Substituted Amino)-3-Pyridazinyl-Hydrazines

Recently, the 6-(substituted amino)-3-pyridazinyl-hydrazines^2–4 and their hydrazones¹ became important as peripheral antihypertensive agents. These compounds have been synthesized from 3,6-dichloropyridazine (1) by introducing to the molecule firstly the substituted amine and then the hydrazine moiety^2–4. This process has some disadvantages. It is known that one chlorine atom of 1 can be easily replaced by nucleophilic substitution. The subsequent replacement of the other chlorine atom in 1 is, however, rather difficult⁵. For example, 2 silosequent substitution with hydrazine should be uarried out with agreat excess of hydrazine at elevated temperatures and the product formed is liable to decompose in this basic medium. As a consequence, overail yield of this process is low ana in general, the final product nas to be purifiea tnroilgh its benzylidene derivative. Tnerefore, according to our experiments, this process does not seem to be useful for large-scale operations.     

A Characterization and the Intersection of the Maximal Compatible Extensions of a Partial Order

We present a characterization of the maximal compatible extensions of a given compatible partial order ≤  _r on a unary algebra (A,f ). These extensions can be constructed by using the compatible linear extensions of ≤  _r*, where (A*,f*) is the so called contracted quotient algebra of (A,f) and the compatible partial order ≤  _r* on (A*,f*) is naturally induced by ≤  _r . Using this characterization, we determine the intersection of the maximal compatible extensions of ≤  _r .      

Improved synthesis of perfluorooctylpropyl amine

Hydrazinolysis of N-perfluorooctylpropyl phthalimide is an easy route to scale up for the title compound. Both the alkylation of potassium phthalimide with perfluorooctylpropyl iodide and the hydrogenolysis of the adduct of perfluoroctyl iodide to N-allyl-phthalimide provide this amine precursor in good yields. The latter procedure, however, has a better atom economy, since it requires only three steps from perfluorooctyl iodide.     

Off-Specular Synchrotron Mössbauer Reflectometry: A Novel Tool for Studying the Domain Structure in Antiferromagnetic Multilayers

The off-specular (diffuse) nuclear resonant reflectivity of synchrotron radiation is a sensitive measure of the lateral autocorrelation of the magnetisation in thin films and multilayers. The width of the diffuse scattering peak measured at an electronically forbidden reflection is inversely proportional to the in-plane correlation length of the magnetisation direction. The average size of the in-plane antiferromagnetic domains is determined in different states of the same Fe/Cr superlattice. The hyperfine magnetic fields in coexisting small and large domains are measured independently. This revised version was published online in August 2006 with corrections to the Cover Date.     

Preparation of Hydroxy-Substituted Hexahydrophthalazinones from Cyclohexane- and Norbornanelactones or Ketallactones

Summary.  Cyclohexane- and norbornanelactones (1, 5) as well as ketallactones (3, 7) and their hydrolytic products (2, 4a,b, 8) react with hydrazine hydrate to yield the hydroxy-substituted hexahydrophthalazinones 9–12. In the cyclizations, the configurations of the bridgehead atoms remain unaltered, and the hydroxy group retains its original position in the hydrazinolysis of 5 and 7. The compounds were characterized by IR, ¹H, and ¹³C NMR spectroscopy. Received September 3, 2001. Accepted October 8, 2001