Susceptibilities of two populations of Aphis gossiper Glover to selected insecticides

Two populations of Aphis gossypii were collected from cotton and melon crops treated with insecticides to control this aphid species. The  susceptibility of both aphid populations to pymetrozine, Pirimicarb, Oxydemeton-methyl and Imidacloprid was evaluated using leaf deep bioassays in Laboratory which were commonly used to control this aphid on both crops. Results showed that LC50 values of these insecticides against clones of cotton aphid were 452, 1427, 1810 and 209 ppm, respectively. LC50 values of the above mentioned pesticides against clones of melon aphid were 625, 688, 523 and 125 ppm, respectively. Lc50 data showed that aphids reared on melon was 2.07, 1.6 and 3.4 times more susceptible than cotton aphids to Pirimicarb, Imidaclopride and Oxydemeton-methyl and 1.4 times more resistant to Pymetrozine, respectively. In conclusion, it has been shown that clones of cotton aphid is on average 3.4-fold less susceptible to Oxydemeton- methyl, 2-fold less susceptible to pirimicarb, 1.6-fold less susceptible to Imidacloprid and nearly 0.7-fold more   susceptible to pymetrozine than clones of melon aphid. There was little difference in susceptibility to pymetrozine between the two populations. It is also suggested that continuous resistance monitoring should be conducted on a regional scale to identify the efficiency of compounds which are applied against this insect species.Key words: Aphis gossypii, cotton, melon, insecticide resistance

Screening and identification of biosurfactant producing marine bacteria from the Caspian Sea

Marine microorganisms have unique physiological properties and novel metabolites such as biosurfactant to live in extreme habitats (e.g. oil polluted environment). The aim of this study was to characterize some biosurfactant-producing bacteria collected from sediment and seawater samples from the Caspian Sea. These bacteria were isolated using enrichment method in ONR7a medium with crude oil as sole carbon source. Five screening tests were used for selection of the bacteria including hemolysis in blood agar, oil spreading, drop collapse, emulsification activity and bacterial adhesion to hydrocarbon test (BATH). The bacteria isolated were identified using molecular methods. Eighteen biosurfactant-producing bacteria (from 44 different colonies isolated) were selected and 9 isolates were screened as predominant biosurfactant producer belonging to Pseudomonas stutzeri (Strain S1-4-2), P. balearica (Strain S1-4-1), Pseudomonas sp. (Strain S2-1), P. stutzeri (Strain R3-2), P. chloritidismutans (Strain K4-1), Achromobacter xylosoxidans (Strain K4-3), Acinetobacter radioresistens (Strain S1-2), Acinetobacter calcoaceticus (Strain K4-2) and Citrobacter freundii (Strain R3-1). The largest clear zone diameters for oil spreading method observed for P. balearica strain S1-4-1 (14 mm). Also, this strain has the best emulsification activity (100 %); surface hydrophobicity (BATH: 77 %) and reduction of surface tension (34.5 mN m-1 ). Thus, this strain selected as the best isolated strains. The results of this study confirmed that there is sufficient diversity of biosurfactant-producing bacteria in the Caspian Sea and the environmental problem can be resolved by application of these bacteria in petrochemical waste water

Colloidal-Chemical Parameters of Petroleum-collecting and Dispersing Surfactants Based on Vegetable Oil Acid Fractions and 2-(Chloromethyl) Oxirane

Novel surfactants have been synthesized by catalytic chloropropoxylation reaction of carboxylic acid fractions of sunflower, olive, cottonseed, soya-bean, castor and corn oils with 2-(chloromethyl)oxirane. Colloidal-chemical parameters as well as petroleum-collecting and petroleum-dispersing capacities of the synthesized chloropropoxylate esters having heterochain of various lengths have been determined. Influence of carboxylic acid fractions composition and length of chloroxypropylene chain on petroleum-collecting and dispersing capacities has been revealed

High‐Performance Zinc Tin Oxide TFTs with Active Layers Deposited by Atomic Layer Deposition

New deposition techniques for amorphous oxide semiconductors compatible with silicon back end of line manufacturing are needed for 3D monolithic integration of thin‐film electronics. Here, three atomic layer deposition (ALD) processes are compared for the fabrication of amorphous zinc tin oxide (ZTO) channels in bottom‐gate, top‐contact n‐channel transistors. As‐deposited ZTO films, made by ALD at 150–200 °C, exhibit semiconducting, enhancement‐mode behavior with electron mobility as high as 13 cm2 V−1 s−1, due to a low density of oxygen‐related defects. ZTO deposited at 200 °C using a hybrid thermal‐plasma ALD process with an optimal tin composition of 21%, post‐annealed at 400 °C, shows excellent performance with a record high mobility of 22.1 cm2 V–1 s–1 and a subthreshold slope of 0.29 V dec–1. Increasing the deposition temperature and performing post‐deposition anneals at 300–500 °C lead to an increased density of the X‐ray amorphous ZTO film, improving its electrical properties. By optimizing the ZTO active layer thickness and using a high‐k gate insulator (ALD Al2O3), the transistor switching voltage is lowered, enabling electrical compatibility with silicon integrated circuits. This work opens the possibility of monolithic integration of ALD ZTO‐based thin‐film electronics with silicon integrated circuits or onto large‐area flexible substrates.Three atomic layer deposition (ALD) processes are investigated for the deposition of zinc tin oxide (ZTO) as the active layer in thin‐film transistors (TFTs). With a low density of oxygen vacancies, as‐deposited films exhibit semiconducting, enhancement‐mode behavior. Post‐deposition anneals result in increased film density and record high electron mobility for ALD ZTO TFTs using process temperatures within the back‐end‐of‐line thermal budget.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156226/3/aelm202000195-sup-0001-SuppMat.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156226/2/aelm202000195.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156226/1/aelm202000195_am.pd

Petroleum-Collecting And Dispersing Chemicals For Cleaning Sea Surface From Thin Petroleum Slicks

Monoethylolamide, diethylolamide and triethanolamine ester synthesized by us based on fish oil and their phosphate derivatives being surface-active and ecologically safe possess a high capacity of petroleum collecting and dispersing. When introducing phosphate group, a tendency to replacement of petroleum slick dispersing by its collection (accumulation into a spot) is observed. Efficiency of the chemicals change depends on the type and concentration of ions in the water. Such salts as NaCl, KI, KBr, and MgSO4 positively influence petroleum-collecting activity whereas K2CO3 and NaHCO3 cause petroleum dispersing

Sources and characteristics of summertime organic aerosol in the Colorado Front Range: perspective from measurements and WRF-Chem modeling

Abstract. The evolution of organic aerosols (OAs) and their precursors in the boundary layer (BL) of the Colorado Front Range during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ, July–August 2014) was analyzed by in situ measurements and chemical transport modeling. Measurements indicated significant production of secondary OA (SOA), with enhancement ratio of OA with respect to carbon monoxide (CO) reaching 0.085±0.003 µg m−3 ppbv−1. At background mixing ratios of CO, up to  ∼  1.8 µg m−3 background OA was observed, suggesting significant non-combustion contribution to OA in the Front Range. The mean concentration of OA in plumes with a high influence of oil and natural gas (O&G) emissions was  ∼  40 % higher than in urban-influenced plumes. Positive matrix factorization (PMF) confirmed a dominant contribution of secondary, oxygenated OA (OOA) in the boundary layer instead of fresh, hydrocarbon-like OA (HOA). Combinations of primary OA (POA) volatility assumptions, aging of semi-volatile species, and different emission estimates from the O&G sector were used in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) simulation scenarios. The assumption of semi-volatile POA resulted in greater than a factor of 10 lower POA concentrations compared to PMF-resolved HOA. Including top-down modified O&G emissions resulted in substantially better agreements in modeled ethane, toluene, hydroxyl radical, and ozone compared to measurements in the high-O&G-influenced plumes. By including emissions from the O&G sector using the top-down approach, it was estimated that the O&G sector contributed to  <  5 % of total OA, but up to 38 % of anthropogenic SOA (aSOA) in the region. The best agreement between the measured and simulated median OA was achieved by limiting the extent of biogenic hydrocarbon aging and consequently biogenic SOA (bSOA) production. Despite a lower production of bSOA in this scenario, contribution of bSOA to total SOA remained high at 40–54 %. Future studies aiming at a better emissions characterization of POA and intermediate-volatility organic compounds (IVOCs) from the O&G sector are valuable

Growth performance and age composition of Salmo trutta caspius in Iranian part of Caspian Sea

The aim of this project is to study the growth and age structure in the Caspian trout, comparison with other coldwater species and check the trend of these parameters in recent years. This study was conducted during 2013 till 2015. Totally, 43 specimens for back calculation and 101 specimens for biometrical study of the Caspian trout have been caught in two month period. Biometric parameters such as length, weight and age of the fish were recorded. Base on Back calculation method in 1393, the average length of fish at ages 1, 2 and 3 years old were 18.98 ± 3.5, 30.5 ± 7.24 and 41.7 ± 9.1 cm. So these age groups are under the adult age and don’t approaching to near the beach and rivers for spawning behavior. Therefore, these length groups cannot be observed in catch composition. The result showed, the mean of gonad weight in this fish was about 11 percent of total weight and number of eggs per gram of gonad calculated about 10.8 numbers. Minimum age and maximum age of this species determined 4 years and 7 years (mean = 5.6) and the most frequency allocated to 5 age group and the frequency of 6 and 7 years has been remarkable. The average length of salmon was 69.2 ± 6.2 cm (minimum 57 and maximum 81 cm) and the average weight was measured 3323 ± 677 g (2400 to 5600 g) in the catch composition. Growth parameters such as k, L_∞ and ø’ was measured 0.18, 104 cm and 3.289 respectively. The amount of b for relation length and weight was 2.9 which imply negative allometry. L_∞ and growth coefficient (K) on the Caspian trout were acceptable range, that it shows good growth the fish in the sea water. Most of the fishes were catched from Cheshmehkileh River. As at present Shilat uses just the broods of the Tonekaboon region for restocking of this species, we recommend using the broods of the western region separately for rehabilitation of the stocks of this region

Colorimetric detection of miRNA-21 by DNAzyme-coupled branched DNA constructs

Fluctuation of nucleic acid expression and ultrasensitive and specific detection of these variations in expression is a crucial subject in molecular medicine and clinical theranostics. A novel DNAzyme-coupled branched hybridization chain reaction (b-HCR) assay is reported for efficient signal-amplified detection of miRNA in this study. This assay was composed of a translator (T) hybridized with miR-21 to initiate the first HCR by hairpin 1 (H1) and hairpin 2 (H2). The primary HCR provided a backbone chain for numerous branches budding through hairpin 3 (H3) and hairpin 4 (H4) assembles. In the presence of hemin, the G-rich domains embedded in H1 and H4 produce an active G-quadruplex DNAzyme upon exposure to a target that could catalyze the oxidation of colorless substrate to colored product. The present approach has the potential to be used for quantitative detection of miR-21 with a sensitivity and a dynamic range of 1 pM and 1 pM to 1 nM, respectively. © 202

Multiplex monitoring of Alzheimer associated miRNAs based on the modular logic circuit operation and doping of catalytic hairpin assembly

In recent years, DNA logic gates have been extensively applied in developing multiplex processing platforms to provide an accurate decision on the diagnosis of multi-factor diseases. In this work, we presented a new cascaded logical operator by combining different modules for computational monitoring of four miRNAs related to Alzheimer disease (has-miR-143-3p, has-miR-18b-5p, has-miR-424-5p, and has-miR-93-5p). Herein, three sequential logic gates were programed that upon entering the miRNA inputs, delivered the trigger strand of CHA (catalytic hairpin assembly) reaction through a cyclic amplification. Afterward, the product of the CHA reaction, three-way junction, could induce the gold nanoparticles aggregation. This phenomenon led to generate a blue color of the solution that enabled visualizing and quantitative measurement of the assay. The output signals were recorded through reading the absorbance intensity transition, dynamic light scattering (DLS), and transmission electron microscopy (TEM). Taken together, the proposed assay by taking advantage of excellent generality, naked eye observation, the 4-plex detection, simplicity, enzyme-free nature, and two-steps process without any immobilization and washing has addressed the limitation of the previous systems. Moreover, the amplified monitoring of low-abundant of target miRNAs was accomplished with a limit of detection as low as 5 pM. © 202

Colorimetric nanoplatform for visual determination of cancer cells via target-catalyzed hairpin assembly actuated aggregation of gold nanoparticles

According to aptamer-mediated hairpin DNA cascade amplifier and gold nanoparticles aggregation, an optical platform for cancer cells determination has been proposed. High-affinity chimeric aptamers were used for cancer cell detection and also as an initiator for beginning hairpin assembly to construct three-way junction (3WJ) nanostructures. These three hairpins were modified at 3� ends with biotin. In the presence of target cell, chimeric aptamer binds to its ligand on cell surface and initiates 3WJ nanostructures formation. These 3WJ nanostructures interact with streptavidin-modified gold nanoparticles (AuNPs) via non-covalent biotin-streptavidin interactions and create a crossover lattice of nanoparticles. This event leads to AuNPs aggregation and red-shifting. The results were confirmed by gel electrophoresis and UV-visible spectrophotometry. The dynamic range of this assay is 25 to 107 cells with a detection limit of 10 cells which is respectively 9 and 4 times more significant than the sensitivity of AuNP-based approaches without amplification and enzyme-mediated signal amplification. Figure not available: see fulltext.. © 2020, Springer-Verlag GmbH Austria, part of Springer Nature