49 research outputs found

    Filogenetska analiza gena za hemaglutinin podtipa H9N2 virusa influence ptica izdvojenih iz tovnih pilića u Iranu.

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    In the present study, the genetic variations were examined of hemagglutinin genes of 4 recent H9N2 subtype avian influenza viruses isolated in the Tehran province of Iran. These hemagglutinin genes were amplified and sequenced in order to compare these viruses with the previous isolates from Iran and some other countries from all over the world. The full length hemagglutinin genes of 112 H9N2 avian influenza strains isolated from chickens, and also migratory birds from all over the world, including 68 strains isolated in Iran during 1998-2012, were genetically analyzed. The amino acids in the hemagglutinin cleavage site of the all 4 recent isolates possessed a PAKSSR/GL motif, which is a different motif when compared with the predominant PARSSR/GL motif in the hemagglutinin of the Iranian H9N2 strains isolated before 2010. All 4 recent isolates possessed histidine, alanin, leucine and isoleucine at positions 183, 190, 226 and 227 respectively, which are the key residues in receptor-binding sites. Genetic and phylogenetic analysis of the hemagglutinin genes showed that recent H9N2 strains isolated from chickens in Iran during 2010-2012, formed a distinct subgroup of the previous strains. Recent changes in the H9N2 viruses may be the result of the widespread circulation of these viruses in recent years. This may be due to the lack of adequate surveillance and control programs, such as vaccination and quarantine. Hence, it is highly recommended that continuous surveillance programs and genetic analysis of ongoing changes to H9N2 should be considered.Istražene su inačice gena za hemaglutinin četiriju nedavno izdvojenih izolata podtipa H9N2 virusa influence ptica na području Teherana u Iranu. Geni su umnoženi i sekvencirani s ciljem da se obilježja virusa usporede s prijašnjim izolatima iz Irana i nekih drugih zemalja u svijetu. Analizirani su geni za hemaglutinin u punoj dužini od 112 izolata H9N2 iz pilića i ptica selica iz cijelog svijeta, uključujući i 68 izolata iz Irana od 1998. do 2012. Aminokiselinski sastav na mjestu cijepanja hemaglutinina svih četiriju nedavno izdvojenih izolata sadržavao je PAKSSR/GL motiv, koji je bio različit u usporedbi s prevladavajućim PARSSR/GL u hemaglutininu iranskih sojeva H9N2 izdvojenih prije 2010. Sva četiri izolata posjedovala su histidin, alanin, leucin i izoleucin na pozicijama 183, 190, 226 i 227, koje su ključne za vezanje na receptore. Genetska i filogenetska analiza gena za hemaglutinin pokazala je da izolati H9N2 iz pilića u Iranu izdvojeni od 2010. do 2012. čine posebnu i različitu podskupinu od prijašnjih izolata. Dokazane izmjene tih izolata mogle bi biti uzrok njihova širenja posljednjih godina. To se moglo dogoditi zbog nedostatka odgovarajućeg programa nadzora i kontrole koji bi obuhvaćali cijepljenje i karantenu. Stoga se posebice preporučuje provođenje programa genetske analize te trajnog praćenja trenutnih promjena podtipa H9N2

    Genotyping of vacA alleles of Helicobacter pylori strains recovered from some Iranian food items

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    Purpose: To study the vacA genotype status of H. pylori isolated from some Iranian food items.Methods: Three hundred assorted samples of fish, ham, chicken, vegetable and meat sandwiches, and minced meat were purchased and tested using culture method. Those that were H. pylori-positive were analyzed for presence of vacA genotypes using polymerase chain reaction (PCR).Results: Sixty out of 300 (20 %) food samples were positive for H. pylori. Vegetable sandwich (45 %), minced meat (32 %) and meat sandwich (20 %) were the most commonly contaminated. The most commonly detected genotypes in the meat-based foods, viz, vegetable sandwich and ready to eat fish, were vacA s1a, vacA m1a and vacA m2, respectively. The most commonly detected combined genotypes were s1am2 (45 %), s1am1a (40 %) and m1am2 (35 %).Conclusion: The presence of similar genotypes in H. pylori strains of foods and those of human clinical samples suggest that contaminated foods may be the source of bacteria for humans.Keywords: Helicobacter pylori, VacA genotypes, Genotyping, Food item

    Temperature-Vegetation-soil Moisture-Precipitation Drought Index (TVMPDI):21-year drought monitoring in Iran using satellite imagery within Google Earth Engine

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    Remote Sensing (RS) offers efficient tools for drought monitoring, especially in countries with a lack of reliable and consistent in-situ multi-temporal datasets. In this study, a novel RS-based Drought Index (RSDI) named Temperature-Vegetation-soil Moisture-Precipitation Drought Index (TVMPDI) was proposed. To the best of our knowledge, TVMPDI is the first RSDI using four different drought indicators in its formulation. TVMPDI was then validated and compared with six conventional RSDIs including VCI, TCI, VHI, TVDI, MPDI and TVMDI. To this end, precipitation and soil temperature in-situ data have been used. Different time scales of meteorological Standardized Precipitation Index (SPI) index have also been used for the validation of the RSDIs. TVMPDI was highly correlated with the monthly precipitation and soil temperature in-situ data at 0.76 and 0.81 values respectively. The correlation coefficients between the RSDIs and 3-month SPI ranged from 0.07 to 0.28, identifying the TVMPDI as the most suitable index for subsequent analyses. Since the proposed TVMPDI could considerably outperform the other selected RSDIs, all spatiotemporal drought monitoring analyses in Iran were conducted by TVMPDI over the past 21 years. In this study, different products of the Moderate Resolution Imaging Spectrometer (MODIS), Tropical Rainfall Measuring Mission (TRMM), and Global Precipitation Measurement (GPM) datasets containing 15,206 images were used on the Google Earth Engine (GEE) cloud computing platform. According to the results, Iran experienced the most severe drought in 2000 with a 0.715 TVMPDI value lasting for almost two years. Conversely, the TVMPDI showed a minimum value equal to 0.6781 in 2019 as the lowest annual drought level. The drought severity and trend in the 31 provinces of Iran have also been mapped. Consequently, various levels of decrease over the 21 years were found for different provinces, while Isfahan and Gilan were the only provinces showing an ascending drought trend (with a 0.004% and 0.002% trendline slope respectively). Khuzestan also faced a worrying drought prevalence that occurred in several years. In summary, this study provides updated information about drought trends in Iran using an advanced and efficient RSDI implemented in the cloud computing GEE platform. These results are beneficial for decision-makers and officials responsible for environmental sustainability, agriculture and the effects of climate change.</p

    Gastric troubles in Iran: The role of social and economic factors in Helicobacter pylori infection

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    Background: Helicobacter pylori infection is a major risk factor for gastric cancer in Iran, but the impact of socioeconomic factors on its prevalence is poorly understood. This study aimed to assess the socioeconomic inequalities and risk factors associated with H. pylori infection in Iran. Methods: This cross-sectional study was conducted based on the PERSIAN cohort study. A total of 20460 individuals aged 35 to 70 years in Ardabil, Iran were included in the study. H. pylori infection was determined based on stool tests and clinical records. Multilevel logistic regression models with random intercepts at household and community levels were used to identify risk factors associated with H. pylori prevalence. The concentration index (CIn) and concentration curve (CC) were employed to assess socioeconomic-related inequality. Results: In this study, 70.4% (CI 69.6–71.0) of the participants were infected with H. pylori, with a higher prevalence in women (71.2%) than men (69.6%). Age (OR: 1.37, CI: 1.17-1.61), sex (OR: 1.20, CI: 1.12-1.28), level of education (OR: 1.33, CI: 1.17-1.49), cardiac disease (OR: 1.32, CI:1.18-1.46), and BMI groups (OR: 2.49, CI: 1.11-5.58) were significantly associated with H. pylori infection based on the multivariable logistic regression. The results of the CIn and CC indicated that H. pylori were more prevalent among economically disadvantaged groups (CIn: -0.1065; [-0.1374 to -0.0755]). Conclusion: The prevalence of H. pylori in Iran is higher than in other developing countries, and significant socioeconomic inequality exists between the poor and the rich. To reduce the rate of gastric cancer, socio-economic and demographic factors, especially the poor and people with low levels of education, should be considered

    Fundamental Frequency in Males and Females from Iranian, Turk, and Kurd Race

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    Background and Aim: Human’s voice is observable and measurable like his other behaviors. Investigations have shown that characteristics of voice differ in males and females and possibly in different languages. Clinically, knowing natural voice characteristics is helpful for distinguishing voice pathologies. So the purpose of this study was to measure and compare the fundamental frequency human voice. Materials and Methods: subjects were young males and females of Iranian Fars, Turk and Kurd races. First the subjects were asked to read some Persian sentences, and then their voice samples were analyzed by Dr.Speech software. Results: Fundamental frequency mean is 168±46 Hz and 120±48 Hz for females and males, respectively, which shows significant difference. There is no significant difference between fundamental frequency mean of different races. Conclusion: There is significant difference between fundamental frequency of males and females, but this difference is not attributable to their mother tongue

    Effect of thermal modification on physical and mechanical behavior of sunflower-polypropylene composites

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    The Use of agricultural plants wastes as an alternative forest resources in the cellulose industry can be recommended due to the severe shortage of wood raw material and restriction of forest harvesting. The aim of current research was to investigate the effect of thermal modification on applied properties of composite made from sunflower stem flour-polypropylene. Thermal modification of sunflower stems was done at temperatures of 160, 180 and 200°C for 30 minutes and mixed with polypropylene in ratio of 30wt%. Test samples were prepared with maleic anhydride-grafted polypropylene as coupling agent by injection molding method. FTIR spectroscopy of sunflower stem flour confirmed the chemically changes due to thermal modification. More integration and uniform distribution, and less cavities were observed in the scanning electron micrographs of failure surface. The removal of hemicellulose of sunflower stem flour improved the thermal stability of composite, which thermal gravimetric analyzer (TGA) confirmed it with increasing in modification temperature up to 180°C. Modification at 200°C decreased thermal stability compared to other temperatures. Thermal modification leads to significant decrease in water absorption and improvement in bending and tensile properties due to hemicellulose degradation, increasing the crystallinity, loss of polarity, increased compatibility between the two phases of composite and uniform distribution of fillers in polymeric matrix. Notched impact strength of modified composites decreased due to better adhesion between lignocellulosic filler and polymer that facilitate the crack development along the interface

    VARIATIONS IN SOIL PROPERTIES AS AFFECTED BY DEFORESTATION ON LOESS-DERIVED HILLSLOPES OF GOLESTAN PROVINCE, NORTHERN IRAN

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    Deforestation and shift of land use to agriculture, is of great concern in Golestan Province andhas brought hazardous problems of flooding, landslide and soil loss. Soil organic carbon, totalnitrogen content, available phosphorous and potassium, calcium carbonate content, thicknessof A horizons and some important soil properties were studied on forested soils and comparedwith the adjacent deforested and cultivated soils. The studied soils were formed on a hillslopewith parent material consisted mainly of loess deposits. Forested and deforested soils wereclassified as Calcic Hapludolls and Typic Hapludolls, respectively. The studied soils were allcalcareous with the pH value of 7-7.9. The soil texture was silty clay loam with the siltcontent of 54-60%. The results revealed that the soil organic carbon, total nitrogen contentand available potassium, were significantly lower in the deforestated soils. The thickness ofmollic horizons was also reduced after deforestation in all studied pedons. While calciumcarbonate contents of the subsurface horizon of the forested soils are significantly highercompared to the surface horizon due to the leaching processes, it is considerably high in thesurface horizons of the deforested soils and does not change significantly with depth. Thispoints to the effect of deforestation and cultivation practices which has led to soil erosion andthe subsequent exposure of the highly calcareous subsurface horizon. Available soilphosphorous did not show any significant change by deforestation
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