Deionized Water Solution Research Articles

Iron nanoparticles supported on graphene nanosheets by pulsed laser ablation method in deionized water

In this study, pulsed laser ablation process (PLA) in deionized water solution was used to prepare graphene oxide (GO) nanosheets, wustite (FeO) nanoparticles and GO based FeO nanoparticles. The effect of composition ratio of materials on their optical properties was studied. The structural properties of the materials were characterized using transmission electron microscopy (TEM) and x-ray diffraction (XRD) techniques. According to the TEM results, FeO nanoparticles were well deposited on GO nanosheets. The XRD results demonstrated the formation of Fe and wustite (FeO) phase of iron oxide nanoparticles. In the XRD analysis of graphene sample, graphene oxide (GO) and reduced graphene oxide (rGO) nanosheets were identified. The absorption measurement of the samples in colloidal state was performed using a UV–vis single beam spectrophotometer in the wavelength range of 250 to 800 nm. The higher and the lower absorbance belonged to 1.4 ml GO − 0.6 ml FeO composition and GO nanosheets, respectively. The linear optical properties of the samples, including the real and imaginary parts of the dielectric function, refractive index, extinction coefficient and absorption coefficient were calculated using the spectroscopic ellipsometry (SE) method. Leng oscillator was used as the optical model in SE method. Also, the energy band gap of the samples was calculated using Tauc relation, in which the lower and the higher energy band gaps were obtained for GO nanosheets (3.40 eV) and FeO nanoparticles (4.65 eV), respectively. Furthermore, the nonlinear optical properties of GO based FeO nanoparticles were investigated by Z-scan measurement. The nonlinear refractive index and nonlinear absorption coefficient were obtained in the order of 10−8 cm2 W−1 and 10–4 cm W−1, respectively.

Genotoxic effects of copper nanoparticles on Vicia pannonica Crantz. root meristem cells

With the increasing use of metal nanoparticles, their access to the food chain has become the main concern for scientists. The present study sheds light on the copper nanoparticles (Cu NPs), which are widely used in many industries today. For this purpose, Vicia pannonica Crantz., a common fodder plant, was used and exposed to metal-based Cu NPs. To determine the genotoxic effects on root meristem cells, total of 3 different concentrations (50 ppm, 150 ppm, and 300 ppm) of Cu NPs and the control in deionized water solutions were prepared. The determination of the accumulation and elimination of Cu NPs in Vicia pannonica used in the study was carried out using with X-ray diffraction (XRD), scanning electron microscopy (SEM), SEM element mapping, and energy dispersive X-ray diffraction (EDS) characteristic spectrum analysis. All doses of Cu NPs caused significant decreases in the Mitotic index of V. pannonica meristem cells compared to the control. Multiple analyzes carried out in the study showed that Cu NPs caused abnormalities in cell division such as C-metaphase, polar aberration, deconstructed anaphase, chromosome breakage, loss of genetic material, failure to assemble in the metaphase plate, deconstructed metaphase, asynchronous division remaining chromosome in metaphase, adhesion, deconstructed prophase, advanced chromosomes, and chromosome bridges in anaphase. Results support that Cu NPs have a genotoxic effect on V. pannonica.

Effects of surface roughness parameters on the shear strength of AA 6061-T6 aluminium alloy in structural adhesive bonding applications

This study aims to investigate the effects of the surface roughness of an aluminium substrate on the adhesive joint strength of aluminium–aluminium specimens prepared using epoxy and methyl methacrylate adhesives for shear strength tests. Aluminium surfaces were mechanically abraded using silicon carbide (SiC) papers with different grit sizes in two different modes. The evaluated bonding performance characteristics included the maximum bonding strength and residual strength of the adhesive joints after their exposure to various environmental conditions. The results demonstrated that excellent adhesion characteristics were obtained at the optimum SiC grit size (grit-80) regardless of the adhesive type. In addition, the topographical and morphological properties of the aluminium surfaces were studied before and after mechanical abrasion via surface profilometry and scanning electron microscopy, respectively. A possible mechanism was proposed to explain the observed shear strength changes and respective modes of fracture after sample exposure to air, de-ionised water, and aqueous salt solutions.

Effect of Crosslinking Agents on Chitosan Hydrogel Carriers for Drug Loading and Release for Targeted Drug Delivery.

Numerous studies report on chitosan hydrogels in different forms, such as films, porous structures, nanoparticles, and microspheres, for biomedical applications; however, this study concentrates on their modifications with different crosslinking agents and observes their effects on drug loading and releasing capacities. Linear chitosan, along with chitosans crosslinked with two major crosslinkers, i.e., genipin and disulfide, are used to formulate three different hydrogel systems. The crosslinking process is heavily impacted by temperature and pH conditions. Three different drugs, i.e., thymoquinone, gefitinib, and erlotinib, are loaded to the hydrogels in de-ionized water solutions and released in phosphate-buffered solutions; thus, a total of nine combinations are studied and analyzed for their drug loading and releasing capabilities with ultraviolet-visible (UV-Vis) spectroscopy. This study finds that thymoquinone shows the lowest loading efficacy compared to the two other drugs in all three systems. Gefitinib shows stable loading and releasing regardless of crosslinking system, and the genipin-crosslinked system shows stable loading and releasing with all three drug molecules. These experimental results agree well with the findings of our previously published results conducted with molecular dynamics simulations.

Influence of multilayers Bernal and Rhombohedral graphene obtained by green chemistry on the acceleration in the germination process of tomato seeds

The environmental ramifications stemming from the application of graphene-based materials have sparked significant interest in recent years. This study delved into assessing the influence of multilayer graphene, specifically focusing on the Bernal (2H) and Rhombohedral (3R) phases, on the germination process of tomato (Solanum lycopersicum) seeds. Multilayers Bernal-Rhombohedral Graphene (MBRG) were synthesized employing green chemistry principles, utilizing the ultrasonication technique operating at 40 kHz within a deionized water solution. Systematic characterization of the phases was conducted via X-ray diffraction, Raman Spectroscopy, TEM, and conductivity measurements. Subsequent administration of MBRG at concentrations ranging from 10 to 500 mgL−1 on tomato seeds revealed an expedited germination process, achieving completion within 3 days. Noteworthy enhancements were observed, including a 12 % absolute increase in germination, a 3 % rise in relative root growth, and a 9 % elevation in the germination index compared to the control. Moreover, a discernible augmentation in root length was evident with escalating concentrations of MBRG, peaking at 50 mgL−1, albeit exhibiting a slight decrement at 500 mgL−1. Additionally, the antioxidant activities of root extracts were assessed across various MBRG concentrations, demonstrating no significant alterations. The outcomes posit that MBRG compositions, comprising 60.44 % (2H) and 39.55 % (3R) phases at specific concentrations, hold promise as a viable additive for expediting early seed germination, thereby presenting a potential sustainable solution in agricultural contexts.

The Optical and Structural Properties of Cu Nanoparticles: Graphene Prepared by Pulsed Laser Ablation in Deionized Water

Background: In this paper, graphene and copper oxide nanoparticles and graphene-based copper oxide nanoparticles have been produced by means of a pulsed laser ablation process (PLA) in a deionized water solution. Methods: The composition ratio of materials has been investigated in the structure of the prepared materials and their optical properties. The absorbance of the samples was obtained by the UV-VIS single beam spectrophotometer in the wavelength range of 290 to 800 nm. Spectroscopic ellipsometry method was used to investigate the linear optical properties of the samples including the real and imaginary parts of refractive index and dielectric function of the samples. The preferred model in the dielectric function modeling was Tauc-Lorentz. Also, the energy band gap of the samples has been calculated using Tauc relation. In addition, the nonlinear optical properties of graphene based copper oxide have been studied by Z-scan technique. Structure of the samples was studied using TEM image. Results: The most and the least absorbance at 532 nm wavelength, and also band gap energy belong to 1.4 ml Gr-0.6 ml Cu and copper oxide, respectively. Conclusion: The band gap energies of the samples were calculated between 3.30 eV and 3.43 eV. The real and imaginary parts of the complex refractive index were obtained in the order of 10-8cm2/W and 10-5cm/W. The results for nonlinear properties show that these samples are suitable for all-optical switching devices.

The effect of temperature on the U-232 and Am-241 adsorption by PN6 microplastics in aqueous solutions.

<p>The effect of temperature on the adsorption of U-232 and Am-241 by PN6 has been investigated in laboratory and environmental water samples (e.g. seawater and waste water) in the picomolar concentration range. Generally, increasing temperature favors radionuclide adsorption, indicating that radionuclide binding by PN6 is an endothermic and entropy-driven process. In environmental waters, Kd values are significantly lower than the corresponding values in de-ionized water solutions, because of the presence of various cations (e.g., Ca2+, Fe2+) that compete the radionuclide adsorption by PN6 and the presence of complexing anions (e.g. CO32-), which complex and stabilize the actinide cations in solution.</p>

Batch adsorption study in liquid phase under agitation, rotation, and nanobubbles: comparisons in a multi-parametric study

Concern for environmental protection has increased throughout the years from a global perspective. To date, the predominance of adsorption as treatment technique in environmental chemistry remains unchallenged. Moreover, the scientific attention for investigating nanobubbles due to their unique properties has turned the search for their application in environmental processes with special emphasis on water treatment. This study is aimed at investigating the effect of rotation on batch adsorption process using commercial activated carbon as adsorbent material, compared with the widely used method of agitation. As liquid medium, deionized water and deionized water enhanced with nanobubbles (of air) were used. The wastewater was simulated by dissolving a common dye as model pollutant, methylene blue, at concentration of 300 mg/L in the tested liquid. The results indicated that the utilization of nanobubbles resulted in an improvement on adsorption rate, compared to the corresponding values of deionized water solutions. These results may lead to promising applications in the future, since just 1 h of operation increases the water purification and thus provides a simply applied, cost-effective, and rapid alternative.

Preparation and Properties of PDMS Surface Coating for Ultra-Low Friction Characteristics.

Polydimethylsiloxane (PDMS) has excellent physical-chemical properties and good biocompatibility. Thus, PDMS has been widely applied in biomedical applications. However, the low surface free energy and surface hydrophobicity of PDMS can easily lead to adverse symptoms, such as tissue damage and ulceration, during medical treatment. Therefore, the construction of a hydrophilic low-friction surface on the PDMS surface could be helpful for alleviating patient discomfort and would be of great significance for broadening the application of PDMS in the field of interventional medical catheters. Existing surface modification methods such as hydrogel coatings and chemical grafting suffer from several deficiencies including uncontrollable thickness, surface fragility, and low surface strength. In this study, a hydrophilic surface with ultra-low friction properties was prepared on the surface of PDMS by an ultraviolet light (UV) curing method. The monomer acrylamide (AM) was induced by a photoinitiator to form a coating on the surface of the silicone rubber by in situ polymerization. The surface roughness of the as-prepared coatings was regulated by adding different concentrations of 2-acrylamido-2-methylpropanesulfonic acid (AMPS) to the monomer solution, and the coating properties were systematically characterized. The results indicated that the roughness and thickness of the as-prepared coatings decreased with increasing AMPS concentration and the as-prepared coatings had good hydrophilicity and low-friction properties. The Coefficient of Friction (CoF) was as low as 0.0075 in the deionized water solution, which was 99.7% lower than that of the unmodified PDMS surface. Moreover, the coating with a lower surface roughness exhibited better low-friction properties. The results reported herein provide new insight into the preparation of hydrophilic, low-friction coatings on polymer surfaces.

Visible-Light-driven Photocatalytic Properties of Copper(I) Oxide (Cu2O) and Its Graphene-based Nanocomposites

In this study, an improved process was proposed for the synthesis of structure-controlled Cu2O nanoparticles, using a simplified wet chemical method at room temperature. A chemical solution route was established to synthesize Cu2O crystals with various sizes and morphologies. The structure, morphology, and optical properties of Cu2O nanoparticles were analyzed by X-ray diffraction, SEM (scanning electron microscope), and UV-Vis spectroscopy. By adjusting the aqueous mixture solutions of NaOH and NH2OH•HCl, the synthesis of Cu2O crystals with different morphology and size could be realized. Strangely, it was found that the change in the ratio of de-ionized water and NaOH aqueous solution led to the synthesis of Cu2O crystals of different sizes, while the morphology of Cu2O crystals was not affected. The synthesized Cu2O crystal samples were used as photocatalysts for methyl orange (MO) dye decomposition, as a model molecule, to evaluate the photocatalytic activities. However, under 200 watts of a visible light source, there are four samples with and without graphene-based nanocomposite of Cu2O NPs. The results showed that, compared with roughly spherical, irregular but thick plates, brick and small granule spheres shaped Cu2O nanoparticles provided better activity. The Cu2O sample with irregular but thick platelet-like shapes, having an average particle size of 0.53 µm, exhibited excellent photocatalytic activity (99.08% degradation). In addition, by reducing the size of Cu2O particles and preparing their graphene composition, one can fabricate a sample (Cu2-Cu2Gr) with the highest efficiency which has significantly better photocatalytic activity in comparison to the others. This work represents an innovative strategy for pre-the-case production of nanomaterials with shapes and sizes, that is, Cu2O crystals, with excellent photocatalytic activity through compositing with graphene

Experimental Tests on Solvent Solutions for the Recycling of Coated Polypropylene in Food Packaging

The aim of this research is to analyze and develop technical methods that allow the recycling of food packaging coated in polypropylene films using solvents for the removal of the lacquer and/or aluminum layer without modifying their mechanical properties. Thus, this would allow the regranulation and re-extraction of the treated material for the creation of new polypropylene films. Water solutions of KOH 1M and methanol 99.9% were tested as solvents using the selective dissolution method. In order to rule out a significant effect of the mechanical stirring action on the removal of the surface layer, a deionized water solution was used as a control sample. By means of UV-VIS-NIR (ultraviolet, visible, near-infrared), LWIR (long-wave infrared), and ATR-IR spectrophotometers, spectrophotometric analyses were carried out on the samples before and after treatment. In order to investigate the efficiency of the solvents in removing the coating of polypropylene films, samples taken from the industry Jindal Films Europe Brindisi s.r.l., named BF (basic film, pp film not lacquered or metallized), AC (aluminum-coated pp film), and ACRC (acrylic-lacquer-coated pp film), were compared with samples treated with solvent solutions. The comparison was made by comparing the spectra obtained from the analyses carried out with the two different spectrophotometers. The absorbance values at the level of characteristic polypropylene spectrum peaks, detected with an ATR-IR, were also compared using the Pearson correlation coefficient. The results suggest that the optimal solvent for removing the aluminum and acrylic lacquer from pp films is the solution of KOH 1M. Future analyses will aim to investigate the maintenance of the mechanical characteristics of polypropylene treated with a selective dissolution using KOH. It is also planned to test the methodology of this study on an industrial scale.

The in vitro effect of solutions with or without sugar in dental bleaching

The interaction of bleaching technique (in-office or at-home) and solutions (deionized distilled water with and without sugar, red wine with and without sugar, coffee with and without sugar) on the effectiveness of in vitro dental bleaching was evaluated. Hydrogen peroxide (HP) 37.5% gel was used for in-office bleaching, 3 applications of 8 min each, 3 sessions with an interval of 7 days. At-home bleaching was performed with 10% Carbamide peroxide (CP), 2 h/day, for 30 days. The enamel vestibular surfaces (n = 72) were subjected daily to test solutions for 45 min, washed with distilled water for 5 min and stored in artificial saliva. The enamel color analysis was performed with a spectrophotometer through color variation (ΔE) and luminosity variation (ΔL). Roughness analysis was performed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Enamel composition was determined by energy dispersive X-ray spectrometry (EDS). The results were submitted to one-way analysis of variance (ANOVA) for ΔE, ΔL and EDS and two-way for AFM. For ΔE and ΔL there was no statistically significant difference. An increase in roughness was observed on the surface when exposed to a sugar-water solution for at-home bleaching and a lower concentration of Ca and P in the deionized water solution with sugar. Solutions containing or not sugar did not influence the bleaching potential, however the presence of sugar in the water solution increased the surface roughness with CP.

Physio-Chemical Preparation of Slow-Release Potassium Fertilizers

Background: In this work, one of the novel types of slow-release fertilizers (SRF)consisting of kaolin as clay material and K2SO4 was synthesized through amechanochemical process by grinding in a ball mill planetary model.Methodology: The test samples of different weight % from 25 to 75 of kaolin contentswere milled for 2 h at fixed milling speeds of about 600 rpm to assess the integrationof K2SO4 and to measure the liberation of K+and SO42-ions into solution. Theproperties of the studied samples were characterized by Fourier transformation infraredspectrometry (FTIR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA),and ion chromatography (IC). Incorporating K2SO4 into an amorphous kaolin structureusing mechanochemistry is a green chemistry method that has been successfullyapplied. K+content was measured in deionized water solution and the soil columnleaching test was performed to determine the slow-release performance of the material.Results: The optimum released amount of K+ after 24 h was for (1:1 wt ratio) kaolin -K2SO4 samples that were 123.9 ppm at milling conditions at 600 rpm milling speed for2 h.Conclusion: Indicating th

Stimuli-Responsive Star Polymer as an Admixture for Crystallization of Hollow Crystals.

Polymers are becoming a very popular tool in the crystallization of different compounds. In this work, a new method of crystallization is proposed using stimuli-responsive star polymer in order to obtain hollow structure crystals. In these experiments, amphiphilic copolymer of acrylic acid (AA) and methyl acrylate (MA) were used for isohydric crystallization via they cooling of KCl in deionized water solution. The experiments were realized in quartz cuvette with a magnetic stirrer using a specialized spectrometer with precise temperature control. The crystallization course was monitored by the absorbance readings and analysis of the nucleation energetic effect. It was proved that the moment of the polymer's phase transition occurrence had an important role in the crystal growth process. On the other hand, the occurrence of phase transition did not trigger the nucleation. The supercoolings achieved in the presence of the polymer were significantly higher compared to pure salt crystallization. On the basis of analysis of Particle Size Distribution (PSD) and Critical Aggregation Concentration (CAC) of the polymer, it was proposed that the hydrophobic particles of macromolecules created from polymeric aggregates served as templates for the formation of hollow crystals. Their purity was verified using thermogravimetric analysis (TGA), 1H NMR, and XRD. Only trace amounts of polymer were found in the crystalline product.

Phase-flip transition in volume-mismatched pairs of coupled 1-pentanol drops.

We have explored a variety of synchronization domains and observed phase-flip transition in a pair of coupled 1-pentanol drops as a function of the volume mismatch. Both experimental observations and numerical studies are presented. The experiments were carried out in a rectangular channel in a ferroin deionized water solution premixed with some volume of pentanol. A single pentanol drop (≥3μL) performs back and forth oscillations along the length of the channel due to the well-known Marangoni forces. In the present work, for a pair of drops, the drop 1 volume was changed from 3 to 5 μL in steps of 1μL, whereas the drop 2 volume was varied from 1 to 3 μL in steps of 0.5μL. A systematic investigation of all the possible combinations of the drop volumes showed the presence of three different types of synchrony-in-phase, antiphase, and phase-switched. In-phase synchronization was robust for a volume mismatch of >3.0μL between the two drops. On the other hand, antiphase synchronization was robust when the volume mismatch was <2.0μL. The phase-switched state is a synchronized state involving a phase-flip transition in the time domain. This state was observed for the intermediate range of volume mismatch. Numerically, the system has been investigated using two Stuart-Landau oscillators interacting via a coupling function in the form of Lennard-Jones potential. The numerical results suitably capture both in-phase and antiphase oscillations for a pair of volume-mismatched pentanol drops.

PD52-03 EVALUATION OF PROTECTION AGAINST GRAM-POSITIVE AND GRAM-NEGATIVE BACTERIA IN A NOVEL IN VITRO BIOFILM MODEL OF PENILE PROSTHESIS

You have accessJournal of UrologyCME1 May 2022PD52-03 EVALUATION OF PROTECTION AGAINST GRAM-POSITIVE AND GRAM-NEGATIVE BACTERIA IN A NOVEL IN VITRO BIOFILM MODEL OF PENILE PROSTHESIS Manish Narasimman, Gregory Plano, Jesse Ory, Sara Schesser Bartra, and Ranjith Ramasamy Manish NarasimmanManish Narasimman More articles by this author , Gregory PlanoGregory Plano More articles by this author , Jesse OryJesse Ory More articles by this author , Sara Schesser BartraSara Schesser Bartra More articles by this author , and Ranjith RamasamyRanjith Ramasamy More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002629.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Late infection, thought to be due to biofilm formation, remains a feared complication after inflatable penile prosthesis (IPP) insertion. Our in vitro model previously showed S. epidermidis, S. aureus, P. aeruginosa, and K. pneumoniae can form significant biofilm on IPPs. P. aeruginosa showed the strongest predilection to grow biofilm. Understanding and preventing this biofilm formation could be a breakthrough in reducing IPP infections. We used our in vitro model to compare growth of different bacterial biofilms on IPPs with and without antibiotics and compare efficacy of antibiotic treated Coloplast Titan® and AMS 700 InhibiZone™ against biofilm formation. METHODS: Sterile IPPs were cut into rings. Coloplast rings were dipped in 10 ml of a 10 mg/ml Rifampin, 1 mg/ml Gentamicin, and deionized water solution and dried. Coloplast and AMS rings were incubated in S. epidermidis, S. aureus, P. aeruginosa, or K. pneumoniae cultures in tryptic soy broth (TSB) for a 2 h attachment period, followed by only TSB for 120 h. We utilized a published and validated method to measure biofilm mass. Rings were fixed with ethanol and biofilm formation measured by spectrophotometer (OD570) after crystal violet staining. RESULTS: Of the bacteria studied, only P. aeruginosa formed significant biofilm on antibiotic treated Coloplast Titan® and AMS 700 InhibiZone™ implant rings. In direct comparison of the implants, no significant difference was found in biofilm formation by P. aeruginosa. CONCLUSIONS: Our novel in vitro model of biofilm formation of IPPs evaluated the effect of a gentamicin/rifampin antibiotic dip on Coloplast Titan® and the anti-infective capacity of minocycline/rifampin precoated AMS 700 InhibiZone™ against various bacteria. Our findings suggest P. aeruginosa can form a significant quantity of biofilm on IPPs even with antibiotic treatments. However, both treated IPPs appear to provide effective coverage against biofilm formation by S. epidermidis, S. aureus, and K. pneumoniae. No significant difference was found between the IPPs in protection against P. aeruginosa. P. aeruginosa should continue to be a specific target of investigation and antibiotic strategies potentially modified to increase coverage against the organism to reduce delayed post-operative IPP infections. Source of Funding: This work was supported by National Institutes of Health Grant R01 DK130991 and Clinician Scientist Development Grant from the American Cancer Society to Ranjith Ramasamy. This work was also supported by the AUA Summer Medical Student Fellowship Award to Manish Narasimman © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e905 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Manish Narasimman More articles by this author Gregory Plano More articles by this author Jesse Ory More articles by this author Sara Schesser Bartra More articles by this author Ranjith Ramasamy More articles by this author Expand All Advertisement PDF DownloadLoading ...

Direct Visualization of UV-Light on Polymer Composite Films Consisting of Light Emitting Organic Micro Rods and Polydimethylsiloxane.

We experimentally demonstrate the direct visualization of ultraviolet (UV) light using flexible polymer composite films consisting of crystalline organic tris-(8-hydroxyquinoline) aluminum (Alq3) micro-rods and polydimethylsiloxane (PDMS). The representative organic mono-molecule Alq3, which is a core material of organic light-emitting diodes, was used to detect light in the invisible UV region and visualize photoluminescence (PL). Alq3 shows absorption in the UV region and light-emitting characteristics in the green region, making it an optimal material for UV visualization because of its large Stokes transition. Crystalline Alq3 micro-rods were fabricated in a deionized water solution through a sequential process of reprecipitation and self-assembly. Highly bright photoluminescence was observed on the highly crystalline Alq3 micro-rods under UV light excitation, indicating that the crystalline structures of Alq3 molecules affect the visible emission decay of excitons. The Alq3 micro-rods were manufactured as flexible polymer composite films using a PDMS solution to observe UV photodetector characteristics according to UV intensity, and it was confirmed that the intensity of the fine UV light reaching the earth’s surface can be visualized by making use of this UV photodetector.

Effect of DNA Aptamer Concentration on the Conductivity of a Water-Gated Al:ZnO Thin-Film Transistor-Based Biosensor.

Field-effect transistor-based biosensors (bio-FETs) are promising candidates for the rapid high-sensitivity and high-selectivity sensing of various analytes in healthcare, clinical diagnostics, and the food industry. However, bio-FETs still have several unresolved problems that hinder their technological transfer, such as electrical stability. Therefore, it is important to develop reliable, efficient devices and establish facile electrochemical characterization methods. In this work, we have fabricated a flexible biosensor based on an Al:ZnO thin-film transistor (TFT) gated through an aqueous electrolyte on a polyimide substrate. In addition, we demonstrated techniques for establishing the operating range of such devices. The Al:ZnO-based devices with a channel length/width ratio of 12.35 and a channel thickness of 50 nm were produced at room temperature via magnetron sputtering. These Al:ZnO-based devices exhibited high field-effect mobility (μ = 6.85 cm2/Vs) and threshold voltage (Vth = 654 mV), thus showing promise for application on temperature-sensitive substrates. X-ray photoelectron spectroscopy was used to verify the chemical composition of the deposited films, while the morphological aspects of the films were assessed using scanning electron and atomic force microscopies. The gate–channel electric capacitance of 40 nF/cm2 was determined using electrochemical impedance spectroscopy, while the electrochemical window of the gate–channel system was determined as 1.8 V (from −0.6 V to +1.2 V) using cyclic voltammetry. A deionized water solution of 10 mer (CCC AAG GTC C) DNA aptamer (molar weight −2972.9 g/mol) in a concentration ranging from 1–1000 pM/μL was used as an analyte. An increase in aptamer concentration caused a proportional decrease in the TFT channel conductivity. The techniques demonstrated in this work can be applied to optimize the operating parameters of various semiconductor materials in order to create a universal detection platform for biosensing applications, such as multi-element FET sensor arrays based on various composition nanostructured films, which use advanced neural network signal processing.

Soaking and hydrous pyrolysis of Indian oil shale: Identification of produced hydrocarbons and moieties

In the present study, soaking and hydrous pyrolysis experiments were performed on Indian oil shale in the presence of de-ionized (DI) water and brine solution under isothermal conditions of 300, 350, and 400 °C, and residence time of 72 h to simulate the effect of underground aquifers on the expulsion and composition of hydrocarbons from source rocks. During soaking pyrolysis, the oil yield increased minutely with the increase in soaking time from 1 to 4 weeks but was not influenced by the presence of brine solution (8.82 wt/wt%) or DI water (8.46 wt/wt%). A similar trend in the generation of oil yield was observed during hydrous pyrolysis in both DI water and brine solution. GC analysis of the gas samples showed methane (CH4) as the prominent gas produced during soaking and hydrous pyrolysis. During soaking pyrolysis, the concentration of C2 to C5 gases decreased with increased pyrolysis temperature. However, during hydrous pyrolysis, the concentration of C4 and C5 gases increased with an increase in pyrolysis temperature. GC-SimDist analysis of the oil samples obtained from soaking pyrolysis at 400 °C showed the compounds ranged from C8 to C38 in brine solution and from C6 to C34 in DI water. Nevertheless, during hydrous pyrolysis in both DI water and brine solution, the carbon number distribution of the oil samples was observed to be in the range of C8 to C38. GC–MS analysis of the oil samples obtained from the soaking and hydrous pyrolysis experiments showed that the molecular weight of the identified compounds ranged from 86 to 380 g/mol. GC–MS, ATR, and 1H NMR analyses showed that the oil samples obtained from soaking and hydrous pyrolysis experiments were rich in aliphatic compounds. The organic acids content appeared to be higher in the presence of DI water as compared to the brine solution.

Evaluation of Bacteria in a Novel In Vitro Biofilm Model of Penile Prosthesis

BackgroundDelayed infection, thought to be due to gradual biofilm formation, remains a feared complication after inflatable penile prosthesis (IPP) insertion. Understanding and preventing biofilm formation is necessary to prevent infections. AimTo develop an in vitro model and compare growth of biofilm by different bacteria on IPPs and evaluate the anti-infective efficacy of the Coloplast Titan and AMS 700 InhibiZone. MethodsSterile IPPs (Coloplast) were cut into rings and incubated with S. epidermidis, S. aureus, P. aeruginosa, A. baumannii, or K. pneumoniae cultures in tryptic soy broth (TSB) (4 hour) to ensure adequate bacteria attachment, and then in only TSB (120 hours) to allow for biofilm formation. Rings were fixed with ethanol and biofilm measured by spectrophotometer (OD570) after crystal violet staining. This methodology was repeated for S. epidermidis and P. aeruginosa with Coloplast rings dipped in 10 ml of a 10 mg/ml Rifampin, 1 mg/ml Gentamicin, and deionized water solution and undipped AMS InhibiZone rings. Crystal violet assay (OD570) was repeated after incubation within bacteria (2 hour), and then only TSB (120 hours). OutcomesThe primary outcome of the study was OD570 readings, indirectly measuring biofilm mass on implant rings. ResultsS. epidermidis, S. aureus, A. baumannii, P. aeruginosa, and K. pneumoniae all formed significant biofilm. P. aeruginosa showed the strongest predilection to grow biofilm on IPPs. P. aeruginosa also formed significant biofilm on antibiotic-treated Coloplast and AMS rings, while S. epidermidis was inhibited. No significant difference was found in biofilm inhibition between the implants. Clinical TranslationOur findings suggest gram-negative bacteria may form biofilm more proficiently and quickly on IPPs than gram-positive organisms. Commonly used antibiotic treatments on IPPs may be effective against S. epidermidis but not against P. aeruginosa biofilm formation. Strengths & LimitationsThis is the first study comparing biofilm formation by different bacteria organisms on IPPs and the inhibitive ability of Coloplast and AMS implants against biofilm formation. Clinical data on organisms responsible for infected IPPs is needed to determine the clinical relevance of our findings. ConclusionOur novel in vitro model of biofilm formation of IPPs evaluated the effect of a gentamicin/rifampin antibiotic dip on Coloplast Titan implants and the anti-infective capacity of the minocycline/rifampin precoated AMS 700 InhibiZone against S. epidermidis and P. aeruginosa. P. aeruginosa was able to grow on both antibiotic-treated implants, with no significant difference, and should continue to be a specific target of investigation to reduce delayed post-operative IPP infections.Narasimman M, Ory J, Bartra SS, et al. Evaluation of Bacteria in a Novel In Vitro Biofilm Model of Penile Prosthesis. J Sex Med 2022;19:1024–1031.