Impact of Climate and Environmental Factors on West Nile Virus Circulation in Iran.

BACKGROUND: Geographic distribution of West Nile virus (WNV) is heterogeneous in Iran by a high circulation in the southern-western areas. The objective of our study was to determine environmental and climatic factors associated with the risk of WNV equine seropositivity in Iran. METHODS: Serological data were obtained from a serosurvey conducted in equine population in 260 districts in Iran. The climate and environmental parameters included in the models were distance to the nearest wetland area, type of stable, Normalized Difference Vegetation Index (NDVI), annual mean temperature, humidity and precipitation. RESULTS: The important risk factors included annual mean temperature, distance to wetlands, local and seasonal NDVI differences. The effect of local NDVI differences in spring was particularly notable. This was a normalized difference of average NDVI between two areas: a 5 km radius area centered on the stable and the 5-10 km surrounding area. CONCLUSION: The model indicated that local NDVI's contrast during spring is a major risk factor of the transmission of West-Nile virus in Iran. This so-called oasis effect consistent with the seasonal production of vegetation in spring, and is associated to the attractiveness of the local NDVI environment for WNV vectors and hosts.

Graphene oxide assisted electromembrane extraction with gas chromatography for the determination of methamphetamine as a model analyte in hair and urine samples.

In the present study, graphene oxide reinforced two-phase electromembrane extraction (EME) coupled with gas chromatography was applied for the determination of methamphetamine as a model analyte in biological samples. The presence of graphene oxide in the hollow fiber wall can increase the effective surface area, interactions with analyte and polarity of support liquid membrane that leads to an enhancement in the analyte migration. To investigate the influence of the presence of graphene oxide in the support liquid membrane on the extraction efficiency, a comparative study was performed between graphene oxide and graphene oxide/EME methods. The extraction parameters such as type of organic solvent, pH of the donor phase, stirring speed, time, voltage, salt addition and the concentration of graphene oxide were optimized. Under the optimum conditions, the proposed microextraction technique provided low limit of detection (2.4 ng/mL), high preconcentration factor (195-198) and high relative recovery (95-98.5%). Finally, the method was successfully employed for the determination of methamphetamine in urine and hair samples.

Narcotic alkaloids of four papaver species from Iran.

Four native Papaver species of Iran, i. e. P. glaucum, P. tenuifolium, P. dubium and P. fugax, were collected from their natural habitat and subjected to HPLC analysis for determination of their morphine, codeine and thebaine content. P. dubium and R. glaucum contained all of the three mentioned narcotic alkaloids, while morphine was not found in P. fugax, and P. tenuifolium was free from codeine.