BACKGROUND Maintaining the quality of clinical specimens for tuberculosis (TB) testing is a major challenge in many high TB burden-limited resources countries. Sample referral systems in low and middle income countries are often weak and the maintenance of the cold-chain challenging and very costly for TB programs. The development of transport media allowing the preservation of samples without ...

The structure of the ribosomal 5 S RNA was examined using Fe(II)-EDTA, a solvent-based reagent that cleaves the phosphodiester backbone of both double- and single-stranded RNA but is restricted by the three-dimensional structure. In the yeast 5 S RNA, cleavages were significantly restricted in six specific regions of the molecule; restrictions in only two of these regions were clearly dependent...

BACKGROUND When Staphylococcus aureus is grown in the presence of high concentration of external glucose, this sugar is phosphorylated by glucokinase (glkA) to form glucose-6-phosphate. This product subsequently enters into anabolic phase, which favors biofilm formation. The presence of ROK (repressor protein, open reading frame, sugar kinase) motif, phosphate-1 and -2 sites, and tyrosine kinas...

Ammonium sulfide ((NH4)2S) exhibits high reactivity as a sulfide reagent in anion exchange reactions that transform CoO to cobalt sulfide nanoparticles (NPs). The faster diffusion of Co(2+) and O(2-) than the incoming S(2-) during the anion exchange causes a significant expansion of the NP voids. The low temperature (70 °C) anion exchange reaction produces amorphous cobalt sulfide NPs with Co :...

The asymmetric tandem oxa-Michael-aldol reaction of salicylic aldehyde derivatives with alpha,beta-unsaturated aldehydes catalyzed by a chiral amine/chiral acid organocatalytic system was investigated. The organocatalytic system of (S)-diphenylpyrrolinol trimethylsilyl ether with chiral shift reagent (S)-Mosher acid presented a synergistic effect in the improvement of reaction performance and o...

The reliability of immunological identification of Neisseria gonorrhoeae using polyclonal and monoclonal antibody coagglutination reagents has been evaluated. When clinical isolates of neisseriae were tested in an "in use" trial the sensitivity and specificity of each reagent were similar and the overall agreement with carbohydrate utilisation was 97.9% (141/144) for the polyclonal antibody rea...

described. One example includes a specific photocleavage of DNA duplex at 5' side of 5'-GG-3' sequence by a "photo-Fenton reagent", whereas the other is the sequenceselective photoreaction of S-AB'Usite of DNA duplex which results in formation of a 2-deoxyribonolactone residue with release of free adenine via selective hydrogen abstraction from C2' of deoxyribose residue. Two types of highly se...

BACKGROUND In 2009, we investigated the conformance of 8 hemoglobin A(1c) (Hb A(1c)) point-of-care (POC) instruments. Since then, instruments have improved and new devices are available on the market. In this second study, we evaluated the performance of DCA Vantage, Afinion, InnovaStar, Quo-Lab, Quo-Test, Cobas B101, and B-analyst Hb A(1c) POC instruments. METHODS Clinical and Laboratory Sta...