Improving municipal solid waste compost process by cycle time reduction through inoculation of Aspergillus niger

A lack of understanding about the effect of microorganism inoculation on compost production and relatively expensive downstream processing are the main obstacles towards an economic compost production. Our work tries to fill this gap. For this, influence of inoculation on the composting of organic fraction of municipal solid waste (OFMSW) to produce compost with higher agronomic value was evaluated. Three similar aerated bioreactors (A, B and C) with the same size and shape in laboratory scale designed. Reactor A was inoculated with the Aspergillus niger IBRC-M 30095, reactor B was inoculated with old compost and reactor C was used as a control. During the composting process temperature, moisture, pH, and electrical conductivity (EC) were evaluated. Also, the ratio of carbon to nitrogen (C/N) and germination index (GI) were measured in during process to evaluate compost maturity. The results of this study showed that the C/Ns decreased to about 63.37%, 59.6% and 46% for bioreactors B, A and control, respectively. Also maximum GI and temperature reached to about 138% and 59 °C in reactor B. Furthermore, our results showed that inoculation with this microorganism reduces process time to 18 days that is better than the results of other researchers and thus results in cost savings. However, we think, Aspergillus niger is appropriate candidate for compost production as a model. Graphical abstractSchematic diagram of experimental reactors: Reactor A was inoculated with the Aspergillus Niger IBRC-M 30095, reactor B was inoculated with old compost and reactor C used as a control without inoculation; (1) composting tank; (2) air compressor; (3) gas flow meter; (4) air regulator; (5) thermal probe; (6) exhausted gas; (7) mixer; (8) effluent; (9) moisture content probe; (10) sampling; (11) electric motor; (12) pump.

Prevalence of Enterobius vermicularis amongst kindergartens and preschool children in Mazandaran Province, North of Iran

Enterobiasis (oxyuriasis) is probably the most common helminth, which infects humans. Amongst different age groups, prevalence of Enterobius vermicularis in children is high compared to adults. Oxyuriasis is one of the most significant parasitic diseases of children. This nematode in children can result in loss of appetite, insomnia, grinding of the teeth, restlessness, endometritis, abdominal cramps, diarrhea and etc. Due to important complications of this parasite, the objective of the current study was to determine the prevalence of enterobiasis in kindergarten and preschool children of Amol, Mazandaran Province, North of Iran. A total number of 462 children from 32 kindergartens of Amol were examined for the prevalence of E. vermicularis infection, 2013. Adhesive cello-tape anal swab method was trained to parents for sampling. In addition, a questionnaire was designed and filled out to collect demographic information for each individual. Data were analyzed using Chi square test and multivariate logistic regression for each risk factor. The overall prevalence of E. vermicularis infection was 7.1 % (33). Although infection with E. vermicularis in girls 7.9 % was higher compared to boys 6.3 %, there was no significant difference between gender and age (p > 0.05) whereas binary logistic regression showed significant difference between enterobiasis and age (p < 0.05). The findings indicated that the prevalence of E. vermicularis in kindergarten and preschool children is relatively high and still is an important health problem and should not be underestimated due to being highly contagious infection. Therefore, educational programs and mass treatment should be carried out in order to reduce infection incidence in this area and regular parasitological test and attention to personal hygiene in kindergarten and preschool is of great importance.

The effect of gender on the pharmacokinetics of verapamil and norverapamil in human

The effects of gender on the pharmacokinetics of verapamil and its active metabolite, norverapamil, following single oral dose (80 mg, Isoptin) to 12 healthy male (mean age: 25.75+/-2.42 years, mean body weight: 70.59+/-9.94 kg) and 12 healthy female subjects (mean age: 24.08+/-2.84 years, mean body weight: 56.67+/-5.23 kg) were investigated in the present study. Plasma concentrations of verapamil and norverapamil were analysed using a modified high-pressure liquid chromatography method. Pharmacokinetic parameters were calculated by non-compartmental analysis for each subject. For verapamil the half-life (t1/2) and mean residence time (MRT) were significantly shorter in women than men (p<0.01 and p<0.05, respectively). For other pharmacokinetic parameters of verapamil there were no significant differences between males and females. For norverapamil, t1/2, MRT and time to reach to the maximum plasma concentration (Tmax) showed statistically significant differences between the two genders. The AUC(0-24) and AUC(0-infinity) ratios of norverapamil to verapamil were also calculated. The ratios were significantly higher in women compared with men. These observations indicate that the elimination rate of verapamil is faster in women than men which may be attributed to the higher activity of CYP3A4 or lower activity of P-glycoprotein in women compared with men. A contribution of both factors in the appearance of gender differences in verapamil pharmacokinetics is also possible.