Advancement in electrochemical DNA-biosensors for GMOs detection: A review

Genetically modified organisms (GMOs) are plants or animals whose genetic make-up has been transformed by recombinant DNA technology, which has new features such as resistance to herbicides, virus and insect. Recently, genetic modification of food products has increased in order to reduce world poverty and hunger and increase food production However, the impact of GMOs on the human health is a growing concern worldwide. Due to increased global production of GMOs, the presence of these in food products need to be monitored and has been attended by many researchers recently. The quick, simple, accurate and sensitive detection methods for these products have attracted the attention. Electrochemical DNA biosensors as one of these fast methods are highly studied by many researchers due to their high sensitivity, low cost, rapid reaction and the possibility of working in aqueous solutions. The present review will focus on several studies on the detection of GMO based on electrochemical biosensors

Phytoremediation of toxic metals in soils and wetlands: concepts and applications (Book Chapter)

Over centuries, industrial, mining and military activities, agriculture, farming, and waste practices have contaminated soils and wetlands in many countries with high concentrations of toxic metals. In addition to their negative effects on ecosystems and other natural resources, toxic metals pose a great danger to human health. Unlike organic compounds, metals cannot be degraded, and clean-up usually requires their removal. Most of the conventional remedial methods have lost economic favor and public acceptance because they are expensive and cause degradation of soil fertility that subsequently results in adverse impacts on the ecosystem. Conventional methods of environmental remediation do not solve the problem; rather they merely transfer it to future generation. Obviously, there is an urgent need for alternative, cheap, and efficient methods to clean-up sites contaminated with toxic metals. Phytoremediation, a plant-based green technology, is cost effective, environmental friendly, aesthetically pleasing approach for the remediation of toxic metals. Due to its elegance and the extent of contaminated areas, phytoremediation approaches have already received significant scientific and commercial attention. Two approaches have been proposed for the phytoremediation of toxic metals from soils and wetlands: natural and induced phytoremediation. Natural phytoremediation refers to the use of hyper-accumulating plants and associated soil microbes, while the induced phytoremediation refers to the use chemicals, especially synthetic chelating ligands, for the increase of metal bioavailability and uptake in plants. Recently, genetically modified plants (GMPs) have been proposed to use in phytoremediation technology; however, this approach is being hindered by ideology-driven restrictive legislation over the use of GMPs. We will discuss the concepts and practical applications of phytoremediation technologies for the restoration of contaminated soils and wetlands. © Springer Japan 2016. All rights are reserved.[Book Chapter

Petroleum hydrocarbon assessment in the wastewaters of petrochemical special economic zone and sediment benchmark calculation of the coastal area - northwest of the Persian Gulf

Petrochemical industries can potentially impact the environment due to their activities and products. This case study has considered adverse effects of petrochemical industries that are located inside the PETZONE with respect to the presence of polycyclic aromatic hydrocarbons and total petroleum hydrocarbon in wastewater effluents. The average concentrations of ∑PAHs group I and II were lower than the guideline values, thus the effluents of the study area can be considered unpolluted. Also, the average concentration of TPH was lower than the guideline value at all almost stations except the effluent outlets of the Razi and Imam Khomeini petrochemical (BI-PC) companies which are proximal to Khowr-e Musa Bay. Thus, they may have an adverse impact on the aquatic ecosystem of the Bay. Therefore, the concentration of TPH was monitored in the sediments of the Bay (around the PETZONE coastal area) which was relatively moderate compared in the study area. Also, the sum of Chronic Potency Ratio of PAHs in sediments showed that the chronic benchmark was not more than the guideline at all stations (it is exceeded when the sum exceeds 1.0) except in the vicinity of the Aromatic effluent outlet of BI-PC. Thus, the chronic benchmark at this station indicates that it has the potential to cause a chronic effect on sediment-residence organisms like crabs, clams and worms. Moreover, PAHs concentration level in this station approached the NOAA sediment quality guideline value (ERL) of 4000 (ng/g dry weight)

Anemia is associated with cognitive impairment in adolescent girls: a cross-sectional survey

Anemia is associated with impairment in oxygen transport, affecting an individual’s physical and mental wellbeing, and work performance. The aim of this study was to examine the prevalence of anemia and its possible association with serum antibody titers to Hsp27 (as an indicator of cellular stress), cognitive function, measures of emotion, sleep patterns in adolescent girls. A total of 940 adolescent girls were assessed to evaluate neuropsychological function with validated questionnaires. A complete blood count was determined as part of the assessment of hematological parameters. Serum anti-Hsp27 was measured for each subject. Among the total of 940 participants, 99 girls (10.5%) were anemic [hemoglobin <12(g/dl)]. Serum anti-HSP27 was significantly higher in anemic compared to healthy girls (p<0.05). There was no significant differences in depression, aggression, insomnia, daytime sleepiness and sleep apnea score between two groups. However, the total cognitive abilities score was significantly lower in the anemic girls (76.8±2.1 versus 85.7±2.5, p = 0.002). Logistic regression analysis showed that anemic girls were 1.73 times more likely than non-anemic girls to have cognitive impairment (95% confidence interval [CI] = 1.07-2.78; P = 0.025). Anemia was associated with elevated levels of anti-HSP27 and supports the hypothesis that cellular stress may be associated with anemia. Anemia was adversely associated with an assessment of cognitive abilities and was an independent risk factor for cognitive impairment in this grou

Evaluation of ecological risk based on the sediment and water quality in Klang Strait, Malaysia / Seyedeh Belin Tavakoly Sany

Sediment and water monitoring was performed from Nov. 2009 to Oct. 2010 to assess and evaluate the spatial and temporal distribution of physical and chemical parameters and biological variables such as PAHs, trace metals (Hg, Cd, Pb, Cu, Mn, Zn, Cr, Ni, V, and Fe), the structure of the benthic community in the sediment, nutrients and chlorophyll a in the water. Sediment and water samples were collected from 22 stations, which covered three coastal ports (North Port, West Port and South Port) and a control point. The primary objectives of this study were to evaluate the sources of pollutants and each pollutant’s distribution, concentration and contamination degree, as well as to assess the biological response to these stressors based on the ecological risk. Significant variations were found in the distribution and concentrations of all heavy metals and PAHs. The spatial and temporal scales of these variations were related to the several sources contributing to the contamination load in the Klang Strait and to seasonal fluctuations, respectively. The highest concentrations of all metals (except for Mn) were recorded at South Port at stations 16 and 17 parallel to the mouth of the Klang River and at station 13 around the container terminal in the West Port, whereas the lowest concentrations were recorded at the control point. Enrichment factor (EF) index also indicated that all metal concentrations except for Fe were influenced by anthropogenic effects. Similarly, the total organic carbon and fine particle size had significant correlations with most metals (Al, Cd, Cu, Fe, Ni, V and Zn). Thus, both natural processes and human activities contributed to the load of these pollutions in the Klang Strait. The PCA analysis is concordant with the pair isomer ratio of PAHs, which revealed that the anthropogenic sources of PAHs were a mixture of pyrogenic and petrogenic sources at all stations except for stations 4, 14 and 21, where combustion was the more frequent cause. Source analysis revealed that PAHs are primarily derived from liquid fossil fuels related to the use of vehicles, crude oil and coal (petroleum combustion sources), and a minor amount of PAHs may be related to the direct discharge of petroleum and land-based runoff. Results revealed that most of the sediment samples are in a pristine state with respect to PAHs and metal contamination except for Cd, As, Hg and Pb. Surface sediment in the Klang Strait are moderately polluted by Hg, Pb and As, and only Cd was estimated to have a high level of contamination. Furthermore, risk analysis showed that living organisms in the strait have a high risk of Cd and Hg exposure and only a low risk of overexposure to the rest of the investigated metals and PAHs at all stations. Regarding the risk index classification, only sediments from stations 16 and 17 (mouth of the Klang River) can be considered to represent a high ecological risk. Other stations were categorized as representing slight to moderate risk, and adverse effects were rarely recorded at the control station, which usually showed normal responses. In addition, the level of response of benthic communities to pollutants in the sediment was completely homogeneous with the risk level in most of the stations. In the case of water-quality assessment, multi-metric indices and operational indicator have been proposed to classify trophic level at different sites. The trophic level of Klang Strait coastal water ranges from eutrophic to hypertrophic. Chl-a concentration was used to estimate the biological response of phytoplankton biomass and indicated eutrophic conditions in the Klang Strait and mesotrophic conditions at the control site. During the study period, no harmful algal bloom (secondary symptom) occurred, which may be related to hydrodynamic turbulence and water exchange, which prevent the development of eutrophic conditions in the Klang Strait. Keywords: Ecological risk, Heavy metal, Polyaromatic hydrocarbons (PAHs), Nutrients, Benthic organisms, Chlorophill a, Klang Strait, Malaysi

Dual-signaling electrochemical ratiometric strategy for simultaneous quantification of anticancer drugs

A novel and unique ratiometric electrochemical sensing strategy for highly reliable and selective simultaneous quantification of Irinotecan (IRI) and 5-Fluorouracil (5-FU) has been developed based on Pd-Au/MWCNT-rGO nanocomposite. Introduction of Pd-Au/MWCNT-rGO significantly improved the speed of electron transport, specific surface area, and electrical catalytic ability of sensing system due to synergistic effect of Pd-Au bimetallic nanoparticles and MWCNT-rGO hybrid structure. The assay strategy was based on the use of ferrocene (Fc) as reference electroactive substance and IRI and 5-FU as analytes with three oxidation peaks at different potentials (Fc at +0.20 V, IRI at +0.58 V, and 5-FU at +1.17 V). The oxidation peak currents of the IRI and 5-FU were gradually enhanced while that of Fc remained almost constant with continuous adding of IRI and 5-FU. By using IIRI/IFc and I5-FU/IFc signals as output, the designed ratiometric system showed good performance with a wide linear range of 0.05-40 mu M for IRI and 0.05-75 mu M for 5-FU and low detection limit of 0.0061 mu M and 0.0094 mu M for IRI and 5-FU, respectively. This study proved that ratiometric strategy is able to eliminate disturbance caused by the sensing environment and possess high sensitivity, reproducibility, stability, and selectivity toward anticancer drugs detection, over potential interferents as well as opens a new procedure for reliable and selective simultaneous analysis of other analytes