-We have found that hydriodic acid can reduce isoalloxazine derivatives to the semiquinone level. Crystals of a solid material, probably an HI complex of the semiquinone hydriodide, containing approximately 100 per cent unpaired spin content, can be obtained from such solutions. The semiquinone hydriodide is also found to form stable 1:1 complexes with various phenols. These may be isolated in ...

New π-conjugated oligomers with high crystallinity were prepared from the simple solvothermal reaction of squaric acid and diaminopyrenes. The oligomers were bonded at the 1,3- and 1,6-positions of the pyrene units, oligo(sq-alt-1,3py) and oligo(sq-alt-1,6py), which greatly affected their planar configuration and resulting mechanochromic properties. Oligomers containing a charge transfer (CT) c...

A study of 552 salmonella cultures revealed that 86 (15.6%) of the cultures fermented lactose. These had been isolated from dried milk products and milk-drying plants. Acid and gas were produced in lactose broth. Solid media containing lactose as the key ingredient for the differential reaction were not satisfactory for recognizing salmonella colonies. No problem was encountered in selecting sa...

Two standard strains of Helicobacter pylori, grown on solid or in liquid medium, were studied for their binding to sialic acid-containing glycosphingolipids on thin-layer plates. NCTC 11637, but not strain 11638, bound to mixtures of gangliosides of various human and animal origins with similar binding patterns and also to polyglycosylceramides of human erythrocytes, leukocytes, and placenta. T...

Mutants of Escherichia coli K-12 unable to excise pyrimidine dimers from their deoxyribonucleic acid (DNA) because of a uvr mutation show a higher survival when plated on a minimal salts medium after exposure to ultraviolet radiation than when plated on a complex medium such as nutrient agar containing yeast extract. This response has been called minimal medium recovery (MMR). Recovery of uvr m...

Deoxyoligonucleotides can now be synthesized rapidly and in high yield because of recent advances in nucleic acid chemistry. Key innovations include solid-phase synthesis on silica-based supports and the development of stable deoxynucleoside phosphoramidites as synthons. When incorporated into manual, semiautomatic, or automatic instruments, these new procedures can be used to prepare probes, m...

silica-bonded n-propyldiethylenetriamine sulfamic acid (spdtsa) is employed as a recyclable heterogeneous solid acid catalyst for the synthesis of benzopyrano[2,3-d]pyrimidines  through one-pot condensation reaction of salicylaldehydes, malononitrile and secondary amines  at room temperature under solvent-free conditions. spdtsa showed much the same efficiency when used in consecutive reaction ...

furin is a ca 2+ -dependent serine protease which cleaves proprotein substrates at the arg-xaa-(lys/arg)-arg    site to generate biologically active proteins. furin’s critical role in many cellular events associated with health disorders such as hiv, sars, anthrax, and influenza as well as cancer has made inhibitors of this enzyme as therapeutic targets. to this date, the most potent inhibitor ...

a mathematical model of sorption of zirconium and hafnium cations mixture and elution of these ions from a cation exchange resin bed is developed. sulfuric acid is selected as the eluent for selective separation of zr and hf in a packed bed of dowex cation exchange resin. the column model is a dispersed plug flow model,and assumed to consist of randomly packed synthetic and spherical resin bead...

turmeric (cucurma longa) has been used as an antioxidant agent in medical as well as health sciences some years ago. however, it has not been applied in tissue culture till now. browning tissues is result of tissue damages caused by polyphenoloxidase enzyme. in order to study this problem and reduce browning, explants are cultured in culture media containing antioxidants including citric acid, ...