Clinical isolates of the opportunistic pathogen Mycobacterium avium complex (MAC) undergo a reversible switch between red and white colony morphotypes on agar plates containing the lipoprotein stain Congo red. Compared to their isogenic red counterparts, white morphotypic variants are more virulent and more resistant to multiple antibiotics. This report shows that the two-component regulatory s...

In this study, the photocatalytic degradation of methyl orange and Congo red dye was investigated inaqueous solution using C,N,S-tridoped SnO2 nanoparticles as a nano photocatalyst. The degradationwas carried out under different conditions including the photocatalyst amount, initial concentrationand pH of the solution. The results indicated that the degradation of methyl orange and Congo redwas...

A total of 187 isolates from several clinical specimens were identified to species level as 129 Staphylococcus aureus strains and 58 coagulase-negative staphylococci (CNS) strains by the API Staph System (Biomerieux). Slime production was detected both by the conventional Christensen's method as well as by the Congo red agar method. Seventy-two strains of staphylococci isolates (38.5%) were fou...

in this work, magnetically separable zno-znfe2o4-ppy nanocomposite as an efficient adsorbent was synthesized by two steps. at first, zinc oxide (zno) and znfe2o4 nanoparticles were synthesized using simple and facile precipitation method. then, zno-znfe2o4 mixed oxide was modified by polypyrrole (ppy). the adsorbent was characterized by x-ray diffraction (xrd), fourier transform infrared (ft-ir...

background: synthetic dyes have several harmful effects on human health as well as aquatic life. in this study, activated carbon (av-ac), based on aloe vera leaf shells, was used as a novel agricultural adsorbent, one that is low-cost and available for the removal of congo red (cr) as a carcinogenic dye from aqueous solutions. methods: in the batch system, the influence of different parameters ...

in the present work, the znfe2o4 nanoparticle has been successfully synthesized. the obtained sample was characterized by x-ray diffraction (xrd), emission scanning electron microscopy (fe-sem) and its optical property was examined by uv-vis spectrophotometer. fe-sem revealed that the particle size of the znfe2o4 of about 47 nm was synthesized. the photocatalytic performance under uv-vis and vi...

a kinetic-spectrophotometric procedure is reported for determination of trace amounts of ag(i). this method is based on catalytic effect of silver ion on the oxidation of congo red by potassium peroxodisulphate at ph=3.4 and 30 oc in the presence of 1,10-phenanthroline as an activator. the reaction was followed spectrophotometrically by measuring the rate of change in absorbance of congo red at...

amyloidosis cutis dyschromica (acd) is a rare form of macular amyloidosis characterized by hypo and hyperpigmented macules. here we described a 20 year old girl with diffuse hypo and hyperpigmentation since she was four years old. five other members of her family are also involved. biopsy of hyperpigmented lesions revealed increase of melanin in the basal layer, pigment incontinence and amorpho...

Disappearance of congo red from the serum has long been considered by many investigators to be the best and most constant indicator of amyloidosis. The congo red test, as shown by Bennhold (1923), measures the proportion of this dye which is retained in the plasma one hour after its intravenous injection. The validity of this test has been the subject of intense discussion. Disappearance of 40-...