Discrete fast Fourier transform-assisted ultraviolet-infrared dual resonance spectroscopy for aerosol detection and identification.

Aerosol decrease is considered as one of the most important environmental challenges. The current study introduces a novel analytical method for accurate and precise detection and identification of different aerosols. The designed array-based spectroscopic method is based on "discrete fast Fourier transform"-assisted dual resonance ultraviolet-infrared spectroscopy for reliable quantitative/qualitative analysis of aerosols like fug, smog, silica-based micro-/nanoparticles, carbon soot, etc. The detection system is arranged using a slice (5 × 5 cm) of a digital versatile disk as a simple, low-cost, available, and size-controllable wavelength selector (grating) and light reflector with control through a software program. The results show that this method is suitable for real-time detection of different types of chemical agent-modified particles with acceptable sensitivity and selectivity and improved detection limit.

Introducing a portable electrochemical biosensor for Mycobacterium avium subsp. paratuberculosis detection using graphene oxide and chitosan.

In this contribution, a novel, low-cost, high throughput, and ultra-selective electrochemical DNA nanobiosensor was developed for accurate on-site detection of Mycobacterium avium subspecies paratuberculosis (MAP) in real media for practical diagnosis of Johne's disease (JD). The method was designed based on the immobilization of graphene oxide and chitosan biopolymer on the surface of a glassy carbon electrode, modified by electrochemical immobilization of graphene oxide and chitosan biopolymer, followed by activation of biopolymer via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxy succinimide (EDC/NHS) coupling system. Afterward, the commercial probe DNA (ssDNA) was stabilized on the activated electrode surface to prepare an ultra-selective ssDNA-stabilized nanobiosensor for MAP sensing called "ssDNA-stabilized GO-CH-EDC/NHS-modified electrode". Several characterization methods distinguished the bioelectrode. The DNA hybridization between the nanobiosensor and target DNA was confirmed by cyclic voltammetry and differential pulse voltammetry. "At optimal experimental conditions, the nanobiosensor showed a linear range of 1.0 × 10-15-1.0 × 10-12 mol L-1, a detection limit as low as 1.53 × 10-13 mol L-1, and a repeatability with a relative standard deviation (%RSD) of 4.7%. The reproducibility was also appropriate, with a %RSD of about 10%. It was used to diagnose MAP in real samples with highly accurate results. Therefore, the developed nanobiosensor can be used for clinical diagnosis of MAP.

Investigation of used cooking oil on the formation of FOG deposits in sewer line clogging.

Fat, oil, and grease (FOG) deposits, resulting from saponification reaction, have been identified as the primary source of blockage of sewer pipes. This mainly emanates from the adhesion of these deposits on pipe walls, culminating in the sanitary sewer overflows (SSOs). This undesired phenomenon poses several challenges for municipalities, including environmental issues, health-related hazards, and an increase in incurred costs. Unlike the previous literature, the present study, for the first time, attempts to characterize the effect of used cooking oils (a mixture of different oils) as a perceived crux, triggering the genesis of deposits. The experimental results revealed that there exists a host of physical and chemical disparities between fresh oil calcium soaps (FOCSs) and used oil calcium soaps (UOCSs). Notably, when mixed with water, FOCSs produced non-miscible layers, whereas a homogenous, sticky, and viscous solution observed for UOCSs. Fourier transform infrared (FTIR) analysis casts light on the fact that the heating process would greatly influence the oil chemical structure and its resultant calcium soaps. In comparison with calcium chloride, as time elapsed, the optical microscope images illustrated that the calcium sulfate clots formation proceeded at an accelerated rate, delivering particles with larger sizes. Viscosity and adhesion are two prominent distinctions between soaps. In sharp contrast to soap produced from oil with a higher palmitic acid content, it was discerned that the oil containing less palmitic acid generates UOCSs with higher viscosity and adhesion than FOCSs. It can therefore be inferred that the distinct chemical structures driven by high temperature during the cooking process produce soaps with different characteristics as compared with fresh oil. This phenomenon would have a profound impact on the formation of the deposits in sewer lines.

Very low frequency waves as selective probe for Cysticercus tenuicollis, Hydatid cyst and Coenurus cerebralis bio-analysis using single cell-signal recording.

Comparative electric behavior of Cysticercus tenuicollis, Hydatid cyst and Coenurus cerebralis at the Very Low Frequency (VLF) region has been studied in detail. This investigation could be significant, because of the economic and public health importance of these parasitic infections in domestic animals. In this report, a single cell signal recording technique has been adopted for comparison using a stainless steel (type: 316, diameter: ~ 300 µm, height: 2.00 cm) two identical electrode system, implanted on the surface of the tested cysts with inter electrode distance of 0.50 cm at a ~ 6.0 giga ohm (GΩ) sealed condition (based on the situation of the implanted electrode system). This process was achieved based on applying electrical interaction between the cysts and the VLF electrical signal. Relative to the measured time domain signal (Current-time diagram), the frequency domain (Current-frequency diagram) was estimated via applying a "Discrete Fast Fourier Transform" (DFFT) algorithm at a fixed time interval (5.0 min). Factors, having important influence on the sensitivity of the detection system including the type (waveform) of different alternating-current (AC) triggering stimulus signals (such as direct current, square wave, triangular, sin (t), etc.), the amplitude, as well as the frequency were optimized automatically through a written "Visual Basic 6" program by one-factor-at-a-time method. Direct applying this AC triggering VLF voltage to the cysts resulted in tracing an AC electrical current vs. time that considered as the time domain wave. However, this electrical current was decayed rapidly versus time during maximum 30.0 s time scale. Applying the DFFT algorithm to the measured time domain, resulted in accessing to the frequency domain at the selected frequency range between 2 and 5 kHz that was considered as the selected frequency for the selective differentiation of C. tenuicollis, Hydatid cyst and C. cerebralis. The related probable mechanism of this process may be attributed to the correlation between the triggering potential and the cyst's electrical surface charge (Zeta potential) as the current source under similar conditions. The results of this study may help to introduce a new detection system for in vivo recognition of the cysts in future.

Tartaric acid as a novel additive for approaching high-performance capacity retention in zinc-ion battery.

Among the rechargeable batteries, aqueous zinc-ion batteries (ZIBs), due to their safety, low cost, eco-friendly, and simplicity in construction, have received much attentions. One of the most critical parts of the battery technology is the electrolyte additives, which have been less studied against their essential roles. To develop the quality of these batteries, specific parameters such as economics, easy design, significant time duration, high electrical discharge, fast charge/discharge rate, acceptable power/ energy density, and acceptable cycle efficiency are essential. In this report, is focused on the aqueous solution of some white crystalline organic acids as novel electrolyte additives such as succinic, tartaric, citric, maleic, and/or acetic acids as battery over-voltage reducing agents to modify the electrical performance of the ZIBs. For instance, significant characteristics of tartaric acid as specially selected electrolyte additive to the ZIBs, exhibit an excellent capacity up to 374 mAh g-1 with acceptable rate capability and high-capacity retention as large as 91.0% after 7200 cycles. To investigate the battery behavior and propose the probable mechanism behind this phenomenon, some analytical methods are utilized.

In Vivo Chemogenetic Biocompatibility of Mercury as a Specific Hypercalcemia Actuator in Snail's Spinal Cord Cell Manipulation: An Extracellular Field Potential Biosensor.

The in vivo chemogenetic property of mercuric ions (Hg2+) was investigated as a specific hypercalcemia actuator in snail's spinal cord cell manipulation by extracellular field potential biosensing analysis. For this purpose, a three-microelectrode system with working, counter, and pseudo reference electrodes was blindly implanted into the snail's spinal cord to electrically stimulate (triggering) the action potential with a staircase electrical voltage at a very low frequency level, along with measurement of the electrical current, as a detection system. Under optimum conditions, using the one-factor-at-a-time method, a wide linear range between 1.0 × 10-14 and 1.0 × 10-1 mol L-1 with correlation coefficients (R2) >0.98 and a response time (t90) of maximum 10.0 s were approximated. Percentages of relative standard deviation were estimated to be 3.08 (reproducibility, n = 50) and 7.31 (repeatability, n = 15). The detection limit was estimated to be sub 2.1 × 10-16 mol L-1 based on the Xb- + 3Sb definition. The reliability of this phenomenon was evidenced by the estimation of recovery percentages (between 95 and 107%) during spiking Hg2+ standard solutions. The probable mechanism behind this process could be attributed to the following: (i) the neuronal ephaptic coupling during electrical synchronization by a specific brain-triggered wave as a neuronal motor toolkit and (ii) chemical synchronization using a Hg2+ hypercalcemia actuator (biosensor). Linear correlation has been evidenced during interactions between Hg2+ and a calcium ionic channel's protein with a gram molecular weight of 66.2 ± 0.3 KCU. This process, therefore, caused an opening of the Ca2+ channel gates and majorly released the Ca2+ (hypercalcemia) that was detected as the main source of the measured electrical current. At this condition, ultratrace levels of Hg2+ ions not only were considered as nontoxic reagents but also had chemically regulating effects as ephaptic synchronizers to the neuron cells. This report may pave the way for using mercury ions at an ultratrace level for clinical controlling purposes during neuronal spinal cord cell manipulation.

Specific Ionic Recognition Using Fig's Xylem/Phloem Vessel as a Novel and Applicable Device: Lab-on-a Xylem/Phloem.

A novel and specific detection system using voltage-stimulating ion transport through fig xylem/phloem vessels as a new lab-on-a xylem/phloem substrate was introduced. The voltage drove the ion flux through the vessels by a sinusoidal waveform with very low frequency (2.70 ± 0.05 kHz, n = 10) and voltage amplitude between 0.0 and 1.0 kV (vs total applied potential) with positive and negative polarities depending on cation and anion separation, respectively. The recorded potential induced by the applied potential was considered as a fingerprint electrical potential stimulator during reliable recognition of different ionic species. The system possessed some different characteristics such as (i) prominent figures of merit with linear ranges between 5.0 and 1200.0 (±0.7, n = 10) ng mL-1 (correlation coefficient, R 2, >0.99) for each ionic species and (ii) improved detection limits via tracing electrical current and conductance gradient (as the sensitive detection systems), while testing 50.0 ng mL-1 of different salts as cationic and anionic species. The reliability of the system was evidenced via focusing on at least 60 independent cationic and anionic species during introducing a 70-membered distinct array-based bio-substrate device. This process not only showed great method applicability for specific determination with acceptable figures of merit but also resulted in introducing a software database for direct detection and recognition of various ionic analyses. The introduced detection/separation device competed with other spectroscopic/electrochemical systems due to the specific and simultaneous recognition of great ranges of ionic species in different real samples at ultratrace levels.

Reusable Extractant and Direct Catalytic Mediation of Water/Oil/Chlorodifluoromethane Nano-Emulsion in Natural Gas Condensate for Efficient Conversion of Chloride Impurities Into the Dicopper Chloride Trihydroxide Nanoparticles.

This research introduces an oil-in-water (O/W) nano-emulsion (oil-water- CHClF 2 ) as the reusable extractant phase using liquid-liquid extraction methodology for the removal efficiency of Cl- and Hg(0) [between 90% and ∼100%, deepening on the nature of the natural gas condensate (NGC)] at a brief separation time (<3.0 min). The achieved safety of the NGC using this nano-emulsion results in efficient reduction in the corrosion rate during testing iron-based fragments (vs. the untreated ones as controls) and increase in the NGC economic value. Another advantage of the synthesized nano-emulsion is its capability and catalytic mediating behavior to efficiently separate and synthesize highly pure dicopper chloride trihydroxide nanoparticles. The synthesized nanoparticles were characterized by different analytical methods such as Fourier transform infrared spectrometry, X-ray diffraction, X-ray photoelectron spectrometry, and direct visualization by some electron microscopies. Direct synthesis, fast synthetic time (<3.0 min), high purity (>99%), and scalability are the main advantages of this synthetic method. This nanoparticle is not only safe but also is efficiently applicable in different industries, especially as an eco-friendly agricultural pesticide for different plants and tress such as pistachio. Consequently, this method is accepted as direct, simple, low-cost, and scalable conversion of some upstream industries with the downstream ones. All these possibilities are attributed to the intermediate transport properties of the introduced O/W nano-emulsion. At this condition, this reagent plays role as a recycled motor for the NGC purification and conversion of these impurities into the safe and usable products. To the best of knowledge, this research is considered as the first report that shows application of this O/W medium for both chloride and mercury removal from the NGC and its direct use as top element in the synthesis of eco-friendly nanoparticles. This system is applicable in some parts of the fuel and oil centers of the "Middle East."

Helminth Eggs as a Magnetic Biomaterial: Introducing a Recognition Probe.

Parasitic helminths, despite their known negative impact (biomaterial) on human health and animal production, have fascinating features. In this study, we find fantastic magnetic properties in several forms: inductor [between 20.10 and 58.85 (±2.50) H], source of detectable electrical voltage [from +0.5 to 7.3 (±0.1) V, vs. the ground, GND, measured by an AVO meter] and different inductor magnitude [between 3.33 and 41.23 (±0.76)] µH, detected by electrochemical impedance spectroscopy as well as frequency scannable electromagnetic wave horn) in several frequencies (including 100, 120, Hz, and 1, 10, 100 kHz) in "Fasciola hepatica", "Parascaris equorum" (with and without larvae), "Dicrocoelium dendriticum," "Taenia multiceps", and "Moniezia expansa" eggs. This claim is attributed to some surprising characteristics, including superior inductance and intrinsic magnetic susceptibility. This feature along with a close relationship to helminth egg structure, is a novel probe with acceptable reproducibility (RSD > 8.0%) and high enough trustworthiness for adequate differentiation in their magnitudes, relatively. These traits were measured by the "Single Cell Rrecording" methodology using a three-microelectrode system, implanted to each egg at the Giga ohm sealed condition (6.08 ± 0.22 GΩ cm-1, n = 5). The reliability of these results was further confirmed using multiple calibrated instruments such as a high-resolution inductance analyzer, LCR meter, impedance spectrometer, potentiometer, and an anomalous Hall effect (Magnetic field density) sensor. In addition, the critical role played (Synergistic Effect) by water-like molecules as the intermediate medium, besides the partial influence of other compounds such as dissolved oxygen, are investigated qualitatively, and specific relation between these molecules and magnetic field creation in helminth eggs was proved. These intrinsic characteristics would provide novel facilitators for efficient arriving at the researchable bio-based magnetic biomaterials, besides innovative and real-time identification probes in the "Parasitology" fields.

Supercapacitance/Resistance Behaviors of Helminth Eggs as Reliable Recognition and Direct Differentiation Probe.

Parasitic helminths are usually known as undesired pathogens, causing various diseases in both human and animal species. In this study, we explore supercapacitance/resistance behaviors as a novel probe for rapid identification and direct differentiation of Fasciola hepatica, Parascaris equorum (with and without larvae), Dicrocoelium dendriticum, Taenia multiceps, and Moniezia expansa eggs. This claim is attributed to some characteristics, such as grave supercapacitance/area, high-energy storage/area, large power/egg, huge permittivity, and great electrical break-down potential, respectively (Fasciola hepatica: 2,158, 0.485, 2.7 × 10-3, 267, 52.6, Parascaris equorum without larvae: 2,825, 0.574, 3.0 × 10-3, 351, 68.4, Parascaris equorum with larvae: 4,519, 0.716, 2.4 × 10-3, 1.96, 97.6, Dicrocoelium dendriticum: 1,581, 0.219, 2.8 × 10-3, 1.96, 48.8, Moniezia expansa: 714, 0.149, 2.2 × 10-3, 0.88, 35.2, Taenia multiceps: 3,738, 0.619, 4.7 × 10-3, 4.63, 84.4), and durable capacitance up to at least 15,000 sequential cycles at different scan rates (between 2.0 × 10-4 and 120.0 V s-1) as well as highly differentiated resistance between 400 and 600 Ω. These traits are measured by the "Blind Patch-Clamp" method, at the giga ohm sealed condition (6.18 ± 0.12 GΩ cm-1, n = 5). Significant detection ranges are detected for each capacitance and resistance with gradient limits as large as at least 880 to 1,000 mF and 400 to 600 Ω depending on the type of helminth egg. The effect of water in the structure of helminth eggs has also been investigated with acceptable reproducibility (RSD 7%-10%, n = 5). These intrinsic characteristics would provide novel facilitators for direct helminth egg identification in comparison with several methods, such as ELISA, PCR, and microscopic methods.

Diode and Active Negative Resistance Behaviors of Helminth Eggs as a Novel Identification/Differentiation Probe.

Helminths have always been studied as one of the critically annoying pathogens of parasite classes due to their adverse effects on the ecosystem of human life. They have the potency to negatively affect their hosts as points of disease, infection, cancer, and death, but in this study, we found interesting electronic properties in Fasciola hepatica, Parascaris equorum (with and without larvae), Dicrocoelium dendriticum, Taenia multiceps, and Moniezia expansa eggs. This claim is attributed to some surprising characteristics such as significant diode behavior [forward bias, 5.36-11.17 (±0.01) V, versus the ground, GND] and backward bias (-45.0 to -125.0 (±7.0) V, versus the GND) and highly active negative resistance (-2.59 to -7.11) × 1015 (±1.5) Ω in the AC mode. These traits were measured by the "blind patch-clamp, single-unit recording" methodology using a three-microelectrode system, implanted onto each tested egg under giga ohm sealed conditions (6.28 ± 0.02 GΩ cm-1 and n = 4). All the characteristic parameters were simultaneously attributed to the helminth egg structure by acceptable reproducibility (percentage of relative standard deviation: > 5%) and high enough rectitude with enough differentiation in their magnitudes, relatively. The reliability of these results was further confirmed using multiple calibrated techniques such as alternative/direct current voltammetry. Also, the significant role of water molecules as the key medium in creating these properties is evaluated qualitatively. In addition, the study aims at introducing these interesting parameters as a new approach to the fabrication of bio-based electronic elements, which are considered as a novel class of helminth egg-detection and -identification probes.

Alternate layer by layered self assembly of conjugated and unconjugated Salen based nanowires as capacitive pseudo supercapacitor.

A novel electrosynthetic method has been introduced based on alternate layer-by-layered self-assembly of conjugated/unconjugated Salen-based nanowires as a capacitive pseudo-supercapacitor. For this purpose, a three-electrode system consisted of a glassy carbon (GC), Ag/AgCl (Sat'd Cl-) and a Pt rod as working, reference, and counter electrodes, respectively. The electrolyte included the same molar concentration (0.040 mol L-1) of each Salen monomer (as initial precursor), and KCl solution (as supporting electrolyte), besides using KOH solution (0.01 mol L-1, as basic-controlling reagent) inside acetone/water (4:1, V/V) as a solvent. The formation of this self-assembly nanowire was attributed to the control of the electrical conductivity of this polymer during formation of an organometallic complex with K+ as responsible complex forming agent. This novel nanowire then played role as a capacitive pseudo-supercapacitor. Based on the chrono-potentiometry, reproducible charge/discharge process for at least 5000 cycles was observed at a potential between - 2.00 and + 1.75 V (vs. Ag/AgCl). The capacity behavior of the polymer was also evidenced using electrochemical impedance spectroscopy. This synthesized polymeric nanowire was adopted as the acceptable pseudo-supercapacitor with real capacity equals to 3110 ± 6 (n = 3) C g-1. This study was considered as the first report at which the self-assembly of organometallic compounds as an efficient pseudo-supercapacitor was introduced.

Fluorescent lamp tungsten filament thermionic emission gun as a novel humidity optical sensor.

Detecting humidity have been remained a continuing concern within some important areas such as structural health, food processing, industrial as well as agricultural products. In this study, a novel humidity optical sensor is introduced based on the thermionic emission of tungsten filament using the fluorescent lamp set-up. Estimated blue compliant using a charged coupling device camera in optical image of the tungsten filament was confirmed as an appropriate detection system for relative humidity (RH) sensing. The fabricated optical sensor has wide linear range (2.0-98% RH), improved detection limit (< 5.0% RH), acceptable saturated limit (> 99.0% RH), improved percentage of relative standard deviation (4.18%, n = 2), adequate hysteresis (< 4.0% RH) and a shorter rise time (< 5.0 s), respectively. The mechanism behind this detection system is based on the interaction between H2O and tungsten filament during formation of W[Formula: see text].x [Formula: see text]O (x = 1-2) in terms of some spectroscopic obtained evidences as well as Fourier transform infrared and X-ray diffraction spectrometries.

Chemogenetic biocompatibly of mercury as specific hypercalcemia actuator in neuronal spinal cord cell manipulation: Zeta bio-sensing analysis.

Chemogenetic property of mercuric ion (Hg2+) was investigated as a specific hypercalcemia actuator in the neuronal spinal cord cell manipulation by Zeta-based potentiometric bio-sensing analysis via introducing a novel array-based Hg2+ bio-sensor. For this purpose, the array of a two-electrode system including Ag/AgCl (sat'd Cl-) as reference electrode and a paste nano-composite as the indicator electrode was utilized. The indicator electrode was made of activated multi-walled carbon nanotubes as conductive support, a grounded slice of sheep's spinal cord as natural neuron stem cells (ionophore), and oxalate ion as both the dispersed phase and cationic site. Under optimum conditions by one-at-a-time method, a two-linear range between 1.3 × 10-4- 6.5 × 10-12 and 2.7 × 10-14- 1.4 × 10-21 mol L-1 with correlation coefficients (R2) of 0.96 and 0.99, respectively, and response time (t90) of maximum 5.0 min were approximated. The percentages of relative standard deviation were estimated to be 4.05 (repeatability, n = 10) and 6.14 (reproducibility, n = 12). The detection limit was estimated to be sub 5.3 × 10-22 mol L-1 based on the X̄b+3Sb. The reliability of this phenomenon was evidenced by different analytical techniques. The Zeta-based electrical response was therefore attributed to highly Ca2+ pumping from the stem cells ionic channel gates as the proposed mechanistic behavior of the spinal cord. Actuating (triggering) the stem cells by Hg2+ consequently led to generate significant Zeta potential as the proposed mechanism. The results pointed to the potentiometric responsibility of a protein with gram molecular weight of 66.2 ± 0.3 KCU in the stem cell matrix as a specific hypercalcemia actuator.

Mechanism behind the neuronal ephaptic coupling during synchronizing by specific brain-triggered wave as neuronal motor toolkit.

Probable mechanism behind the neuronal ephaptic coupling is investigated based on the introduction of "Brain"-triggered potential excitation signal smartly with a specific very low frequency (VLF) waves as a neuronal motor toolkit. Detection of this electric motor toolkit is attributed to in-vitro precise analyses of a neural network of snail, along to the disconnected snail's neuronal network as a control. This is achieved via rapid (real-time) electrical signals acquisition by blind patch-clamp method during micro-electrode implanting in the neurons at the gigaseal conditions by the surgery operations. This process is based on its waveform (potential excitation signal) detection by mathematical curve fitting process. The characterized waveform of this electrical signal is "Saw Tooth" that is smartly stimulated, alternatively, by the brain during triggering the action potential's (AP's) hyperpolarization zone at a certain time interval at the several µs levels. Triggering the neuron cells results in (1) observing a positive shift (10.0%, depending on the intensity of the triggering wave), and (2) major promotion in the electrical current from sub nano (n) to micro (µ) amper (nA, µA) levels. Direct tracing the time domain (i.e., electrical signal vs. time) and estimation of the frequency domain (diagram of electrical response vs. the applied electrical frequencies) by the "Discrete Fast Fourier Transform" algorithm approve the presence of bilateral and reversible electrical currents between axon and dendrite. This mechanism therefore opens a novel view about the neuronal motor toolkit mechanism, versus the general knowledge about the unilateral electrical current flow from axon to dendrite operations in as neural network. The reliability of this mechanism is evaluated via (1) sequential modulation and demodulation of the snail's neuron network by a simulation electrical functions and sequentially evaluation of the neuronal current sensitivity between pA and nA (during the promotion of the signal-to-noise ratio, via averaging of 30 ± 1 (n = 15) and recycling the electrical cycles before any neuronal response); and (2) operation of the process on the differentiated stem cells. The interstice behavior is attributed to the effective role of Ca2+ channels (besides Na+ and K+ ionic pumping), during hyper/hypo calcium processes, evidenced by inductively coupled plasma as the selected analytical method. This phenomenon is also modeled during proposing quadrupole well potential levels in the neuron systems. This mechanism therefore points to the microprocessor behavior of neuron networks. Stimulation of the neuronal system based on this mechanism, not only controls the sensitivity of neuron electrical stimulation, but also would open a light window for more efficient operating the neuronal connectivity during providing interruptions by phenomena such as neurolysis as well as an efficient treatment of neuron-based disorders.

Novel method for scalable synthesis of wollastonite nanoparticle as nano-filler in composites for promotion of anti-corrosive property.

This study is focused on novel anti-corrosive support. This coating is based on the mixed matrix (MM) including epoxy and its hardener as thermoset polymer, melamine-formaldehyde as the organic phase, activated graphite as both inorganic and conductive phases, as well as wollastonite nanoparticles as filler. The wollastonite nanoparticles are synthesized by the new and novel method as suitable etching using hydrofluoric acid, "HF" at room temperature (25 â„ƒ). The synthesized wollastonite nanoparticles are then adapted as a suitable filler during the formation of a new type of MM anti-corrosive coating for the preservation of metals form any corrosion. According to the results, during coating the MM, significant positive characteristics such as enough positive open circuit potential (OCP), small enough (icorr), low cost, significant chemical/mechanical stability and acceptable flexibility are observed. Based on to the weight-loss analysis test on the MM-modified stainless steel during a 42-day time interval, the corrosion rate % is decreased from 74.86 to 0.34. In addition, the electrochemical impedance spectroscopy reveals major enhancements in the double-layer resistance and solution resistance of the cell system. Based on the electrochemical measurements, noticeable reduction and enhancement are observed in the correction rate and potential, respectively, during introducing hard corrosive conditions such as NaCl (3.0%, w/v) and HCl (1.0 mol L-1) environments that reveal the acceptable anti-corrosive behavior of the synthesized MM. The introduced MM is therefore considered as low cost, safe, eco-friendly, industrial-justified anti-corrosion support.

A new whole-cell biocatalyst for sulfur dioxide filtering and degradation.

In this study, the interaction of the magnetotactic bacterium with sulfite compounds and their potential to degrade SO2 was investigated using cyclic voltammetry (CV), molecular emission cavity analysis (MECA) and ion-exchange chromatography (IEC). This biofilter was able to degrade SO2 up to 22281 mg m-3 by disproportionation reaction and the formation of S2- and SO42- with ≥99% efficiency. Designed biofilter was able to restart the initial performance at least after seven cycles if it was used at 14-day intervals. According to theoretical studies, the value of mean free energy (E) obtained using the Dubinin-Radushkevich isotherm model was 0.02 kJ mol-1, which is in the range expected for physical adsorption. Designed biofilter can be considered as a powerful tool to degrade SO2 in diverse urban and industrial centers.

Introducing a bioelectrochemical method for highly selective enumeration of magnetotactic bacteria.

In this study, we employed an electrochemical (potentiometric) method to enumerate magnetotactic bacteria (MTB) during its coupling with iodometric titration to obtain a selective, precise and rapid counting system. Oxygen was considered as an important factor for the orientation and movement of MTB towards the magnet-modified indicator electrode. In the direct potentiometry, a linear correlation was detected between potentiometric response and dissolved oxygen (DO) concentrations. By the increase of the DO concentration, potential difference would increase in the range of 4.0 to 20.0 parts per million (ppm) at different pressure conditions. The reliability of the O2 bio-sensing feature provides a selective MTB-based cell enumeration methodology based on indirect potentiometric titration. Furthermore, a five-minute H2-purging resulted in an increase of potentiometric response sensitivity arising from the decrease in DO concentration of the electrolyte solution. Results were also investigated by zeta potential difference, which show the effect of charge density of MTB in presence of DO. Zeta potential was increased proportionally by addition of the MTB population. Regarding the reliability of the suggested method, data obtained by the designed system showed no statistical difference from those obtained by the most common procedure in microbiology for enumeration of bacteria, known as colony forming unit (CFU) method.

Selective ultrasonic assisted synthesis of iron oxide mesoporous structures based on sulfonated melamine formaldehyde and survey of nanorod/sphere, sphere and core/shell on their catalysts properties for the Biginelli reaction.

Sulfonated melamine-formaldehyde including iron oxide nanoparticles were synthesized by sulfonation of melamine-formaldehyde and then Fe3O4 nanoparticles were bounded onto the surface of sulfonated melamine-formaldehyde (SMF). Two different iron oxide nanostructures including nanorods/spheres and nanospheres on sulfonated melamine-formaldehyde (SMF/Fe3O4) were obtained only by modifying the time of radiation from 4 to 8 h in our synthetic method. Furthermore core/shell (Fe3O4@SMF) was prepared by entrapping Fe3O4 magnetic nanoparticles as the core and sulfonated melamine-formaldehyde as the outer shell. The prepared components were characterized via, Fourier transform infrared spectroscopy (FT-IR), titration, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) analysis, Barret-Joyner-Halenda (BJH) analysis, vibrating sample magnetometer (VSM), energy-dispersive X-ray (EDX) spectroscopy, and thermal gravimetric analysis (TGA). According to obtained results, the synthesized products had a thermal stability near 180 °C, particle-size distribution around of 20-140 nm and surface area between 6 and 10 m2/g. In this study, vapor was used as a heat source. These effective and magnetically recoverable catalysts were employed for the synthesis of numerous 3,4-dihydropyrimidin-2(1H)-ones by utilizing aldehydes, ethylacetoacetate and urea. Functional easiness, excellent yields, short reaction time, the simplicity of work-up or filter, and thermal stability of these catalysts created them as appropriate heterogeneous systems and acceptable alternative to different heterogeneous catalysts.

Sulfur-Functionalized Fullerene Nanoparticle as an Inhibitor and Eliminator Agent on Pseudomonas aeruginosa Biofilm and Expression of toxA Gene.

Over the last decade, nanotechnology-based therapeutic platforms have been directed toward developing nanoparticles with unique properties to combat biofilms. In this study, we evaluated the antibiofilm activity of the sulfur-functionalized fullerene nanoparticles (SFF Nps) against Pseudomonas aeruginosa and also analyzed the effect of this nanoparticle on the expression of exotoxin A (toxA) gene. The functionalized fullerenes were prepared by chemical vapor deposition method. We assessed the potential of SFF Nps to inhibit biofilm formation and eradicate preformed biofilms. Also, the effect of this nanoparticle on the expression of toxA gene was investigated by real-time PCR. The minimum biofilm inhibitory concentration of SFF Nps was 1 mg/mL. The minimum biofilm-eradication concentration of SFF Nps on the young (24- and 48-hr old) and older (72- and 96-hr old) biofilms was 2 and 4 mg/mL, respectively. Field emission electron scanning microscopy images confirmed the potent ability of SFF Nps to eradicate biofilm of P. aeruginosa. The expression of toxA was downregulated in the presence of SFF Nps. In conclusion, considering the ability of SFF Nps to kill P. aeruginosa biofilm and downregulate the expression of exotoxin A, this nanoparticle can be used for treatment of both chronic and acute P. aeruginosa infections.