introduction: periodontitis is a multi-factorial inflammatory disease of periodontium. a precise mechanism in which smoking affects periodontium is not accurately understood. this study was planned to survey salivary osteocalcin (oc) level among smokers with chronic periodontitis and its comparison to non-smoker patients which may help achieve a better understanding of mechanisms being involved...

the purpose of this survey was to evaluate natural occurrence and content of aflatoxin m1 (afm1) in dairy products marketed in urmia (iran). during september 2007, 40 samples of pasteurized milk, 40 samples of ultra high temperature treated (uht) milk, 40 samples of creamy cheese and 40 samples of iranian feta cheese were collected from different supermarkets in urmia city. afm1 contents were d...

background: aflatoxin m1 (afm1) as a carcinogenic and toxic compound has considerable significance from public health viewpoint. the aim of this study was to determine the level of afm1 in pasteurized and uht milk in west-azerbaijan province of iran. methods: a total of 360 commercial milk samples including 220 pasteurized milk and 140 ultra-high-temperature (uht) milk were purchased randomly f...

cholera toxin b subunit (ctb) has been extensively studied as an immunogen, adjuvant, and inducer of oral tolerance in many investigations. production of ctb has been carried out in the bacterial, plant, insect and yeast expression systems. in this study the expression of the ctb containing a 6xhis-tagged was performed by escherichia coli (e.coli) m15. the yield of purified pentameric recombina...

results the optimal conditions were considered to perform elisa. comparison between results obtained from optimized elisa kit and commercial elisa kit showed a good agreement. background haemophilus influenzae type b (hib) infection has high morbidity and mortality rate, especially in children under 5 years of age. enzyme-linked immunosorbent assay (elisa) technique is the most used method to d...

the location of extracellular enzyme activities in soil aggregates can be influenced by slope position. this study aims to determine the effect of slope position on aggregate distribution of organic c and l-glutaminase activity. the soils were collected from different slope positions (shoulder, backslope, footslope and toeslope) at two pasture ecosystems (fereydoonshahr and chelgerd, central ir...

Novel hybrid magnetic cross-linked enzyme aggregates of phenylalanine ammonia lyase (HM-PAL-CLEAs) were developed by co-aggregation of enzyme aggregates with magnetite nanoparticles and subsequent crosslinking with glutaraldehyde. The HM-PAL-CLEAs can be easily separated from the reaction mixture by using an external magnetic field. Analysis by scanning electron microscopy (SEM) and confocal la...

The high cellulase enzyme dosages required for hydrolysis of cellulose is a major cost challenge in lignocellulosic ethanol production. One method to decrease the enzyme dosage and increase biocatalytic productivity is to re-use β-glucosidase (BG) via immobilization. In the present research, glutaraldehyde cross-linked BG was entrapped in calcium alginate gel particles. More than 60% of the enz...

BACKGROUND Increasing attention has been focused on inulin and levan-type oligosaccharides, including fructosyl-xylosides and other fructosides due to their nutraceutical properties. Bacillus subtilis levansucrase (LS) catalyzes the synthesis of levan from sucrose, but it may also transfer the fructosyl moiety from sucrose to acceptor molecules included in the reaction medium. To study transfru...