Basic Medium Research Articles

A structural, magnetic and colloidal stability study of uncoated and silica coated iron oxide samples prepared in two different surfactants

The discovery of new magnetic materials of interest in the biomedicine field is a relevant topic in current research. For years, our research group has been investigating the obtaining and study of nanostructured magnetic samples that behave superparamagnetically to enable their transport in living organisms. We present here a study that summarizes the structural characteristics, magnetic behavior and stability of two Fe3O4 samples synthesized by coprecipitation that were dispersed using two different surfactants (oleylamine, OL, and oleic acid, OA), and two others prepared from the previous ones by reaction with tetraethyl orthosilicate (TEOS). The relationships between the surfactant used in the synthesis, the presence of a certain maghemite (γ-Fe2O3) content, the influence of silica shell thickness and magnetic behaviour of all samples were systematically studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), Mössbauer spectroscopy and H vs. M loops. Rietveld refinements of the XRD profiles confirmed a partial oxidation of the non-silica-coated samples and FTIR spectra of the uncoated samples showed a very strong broad metal-oxygen band and additional sets of bands from the different organic chains of the two surfactants. Individual particles with a mean diameter of 7 and 9 nm were distinguished in TEM images of uncoated magnetic samples. Mössbauer data indicated the presence of non-stoichiometric magnetite in all samples, in agreement with XRD refinements. Magnetic measurements confirmed the superparamagnetic behavior of all the samples. Highest negative zeta potential values are found for the silica covered samples in both acidic and basic medium, being Fe3O4-AO@SiO2 the best suited for the purposes of its dispersibility in future applications. Low polydispersity index (PDI) values confirmed the best stability and dispersibility of all samples investigated in tetrahydrofuran (THF).

Polyoxometalate-derived anti-aggregation MoC nanoparticles for efficient hydrogen evolution in basic and acidic media

As a cost-effective alternative to Pt-based catalysts, molybdenum carbide (MoC) exhibits considerable potential for catalysing hydrogen evolution reaction (HER) in both alkaline water electrolyzers and proton exchange membrane water electrolyzers. However, achieving ampere-level current densities at low overpotentials remains challenging for MoC-based electrocatalysts. In this study, we utilized electrospinning technology followed by a subsequent heat treatment to successfully synthesize monodisperse MoC nanoparticles (approximately 4.3 nm) embedded in carbon nanofibers. The resultant self-supporting one-dimensional molybdenum carbide@nitrogen-doped carbon nanofiber (MoC-A@NCNF), prepared with polyoxometalate anion (POM) and polyvinylpyrrolidone (PVP), exhibits excellent anti-aggregation behavior. Benefiting from its high specific surface area and one-dimensional conductive network structure, the MoC-A@NCNF displays outstanding hydrogen evolution reaction (HER) performance in both 1 M KOH and 0.5 M H2SO4, achieving overpotentials of 491 mV and 568 mV at a current density of 1 A cm−2, respectively. Furthermore, it exhibits exceptional electrochemical stability during prolonged HER testing under both acidic and alkaline conditions.

DNA Probing of Peroxidase‐Mimetic Activities of Selected Manganese‐Based Nanozymes and Measurement of Antioxidant Activity for DNA Protection

AbstractThree different Mn‐based peroxidase‐mimetic nanoparticles (NPs) were synthesized as nanozymes: (i) manganese (II)‐ferrite (MnFe2O4) fabricated by co‐precipitating MnCl2.4H2O and FeCl3.6H2O; (ii) MnO2 synthesized from precipitation of MnSO4 in basic medium; (iii) manganese oxide obtained by reducing KMnO4 with tris(2‐hydroxyethyl) amine, all characterized using STEM, EDXS, FTIR and XPS techniques. These NPs acted as peroxidases, revealed by using a DNA probe, on which the damage generated by peroxidase mimetic NPs was monitored spectrophotometrically by CUPRAC and 3,3′,5,5′‐tetramethylbenzidine (TMB) methods. Results were confirmed by RP‐HPLC and voltammetry, the latter involving an AuNPs‐modified glassy carbon electrode (GCE), multi‐walled carbon nanotubes (MWCNT) and Nafion combination. Colorimetric assay with CUPRAC rather than TMB better agreed with chromatographic/voltammetric findings in detecting both peroxidase activity and DNA hazard. Mn(III)‐containing manganese oxide from permanganate reduction had stronger peroxidase activity. The proposed method demonstrated protective effects of antioxidants (morin, catechin and quercetin) against oxidative DNA damage for the first time.

Metal oxide/chalcogenide/hydroxide catalysts for water electrolysis

Electrochemical water electrolysis has gained rapid and significant interest from scientists and researchers in hydrogen production to reduce the dependency on fossil fuels and hydrogen culture recognition worldwide soon. However, developing highly efficient, economical, and durable electrocatalysts with the replacement of noble-metal-based catalysts is essential for the large-scale practical application of this strategy. Due to heightened interest in this field, a series of various bifunctional catalysts have been developed, and several articles have been published on overall water splitting (OWS). Herein, we studied an extensive kind of recent literature on designing novel metal oxide/chalcogenide/hydroxide catalysts electrocatalysts ranging from metal oxide/hydroxide and metal chalcogenides for water electrolysis. This includes the analysis of characteristics of oxygen and hydrogen evolution reactions (OER/HER) and OWS in basic, acidic, and neutral media and indices for evaluating the performance of electrocatalysts at first and then synthesis routes to obtain metal oxide/chalcogenide/hydroxide electrocatalysts are critically reviewed. Finally, the prospects of activation strategies to enhance the performance of electrocatalysts and activity descriptors are discussed. Moreover, this review will provide a route for constructing high-performance noble-metal-free electrocatalysts in sustainable water electrolysis reactions for hydrogen production.

For elements-utilization regeneration of spent LiFePO4: Designed basic precursors for advanced polycrystal electrode materials

Spent lithium iron phosphate (LFP) is commonly recovered by hydrometallurgy to prepare Li2CO3 and FePO4, but suffering from long process and low value-added products. Hydrothermal method avoids element separation and regenerates LFP materials directly from leaching solution of spent LFP. However, it requires three-time the theoretical amount of lithium. In this study, using LiFePO4(OH) (LFPOH) as a medium, LFP materials were regenerated with theoretical amount of lithium in virtue of energetically favorable reaction of Li-ions into the internal structure. The formation mechanism of LFPOH and LFP materials were investigated, and advanced polycrystal LFP materials with fast ions-diffusion ability and high reversibility were obtained. The capacities of recovered LFP materials are 156.17 mAh g−1, 148.51 mAh g−1, 138.34 mAh g−1, 124.1 mAh g−1 at 0.2 C, 0.5 C, 1 C and 2 C, respectively and their capacity could be remained 139.92 mAh g−1 at 1 C with retention of almost 100 % after 200 cycles. Moreover, with the assistance of economic analysis, the designed regenerated path displayed considerable recycling value-potential, especially the reducing of Li-resources (from three-time to one-time). This study sheds light on designing polycrystal recovered LFP with help of basic medium, whilst provides an effective strategy for preparing high-performance LFP materials.

Synthesis, Docking Study, and Antimicrobial Activity of Some New Heterocyclic Compounds Bearing Naphthalene Moiety

AbstractUpon reaction with α,β‐unsaturated nitriles (2 a–d) and/or salicylaldehyde, 3‐(naphthalen‐2‐yl)‐3‐oxopropanenitrile (1) yields pyridine derivatives 3 a–d and/or the imino chromene derivative 4. Compound 1 reacted with phenyl isothiocyanate in a basic medium to give the intermediate potassium salt 6. Upon stirring at room temperature, the intermediate 6 with some α‐halogenated compounds yielded the acyclic compounds 7, 9, 11, 13, and 15. On the other hand, refluxing intermediate 6 with the same α‐halogenated compounds in DMF in the presence of TEA afforded the corresponding thiophene derivatives 8, 10, 12, 14, and 16. The reaction of thiol 17 with hydrazine hydrate derivatives 18 a–d yielded the corresponding pyrazole derivatives 21 a–d. Compound 20 reacted with o‐phenylenediamine or o‐aminothiophenol in the presence of DMF/TEA to give the corresponding benzothiazole or benzoimidazole derivatives 27 a and 27 b, respectively. Thirty new synthesized compounds were examined for their antibacterial activity against Gram‐positive bacteria including S. aureus and B. subtilis, Gram‐negative bacteria such as P. aeruginosa and E. coli, and yeast‐like fungi like C. albicans in vitro. Compounds 15, 16, 21 d, 27 a, 27 b, exhibited the highest antibacterial activity against Gram‐positive bacteria. Molecular docking experiments were conducted to explore the binding affinities and interaction modalities of selected derivatives with the target PDB‐3cmt protein.

Improvement of Growth Rate in In Vitro Culture of Paphiopedilum primulinum M. W. Wood & P. Taylor and Paphiopedilum glaucophyllum J. J. Smith using Banana Enrichment Media.

Paphiopedilum primulinum and Paphiopedilum glaucophyllum have unique labellum colour and shaped like lady's slippers. These orchids are from the Cochlopetalum section, which is exclusively found in Sumatra and Java. There are so many people that desire to collect these plants illegally. Due to extensive commercial exploitation, Paphiopedilum is in danger of going extinct. Tissue culture techniques are utilised to conserve threatened orchid germplasm in a short time. The success of the in vitro culture depends on the accuracy of the basic media composition used. The Ambon Lumut banana (ALB) can accelerate plant growth and cell division. Banana added to the culture medium was prepared by mashing the ripe flesh (3.5 months old) using a mortar. This research aims to investigate the effect of banana homogenate supplemented media for the orchids P. primulinum and P. glaucophyllum based on the parameters of difference of plant height (calculated from the base of the stem to the tip of the plant stem), number of leaves, and number of roots. The measurement method was carried out using a ruler with a centimetre scale. Observations and documentation were carried out once a week for 7 weeks after planting (WAP) for P. primulinum and P. glaucophyllum. The results showed that ½ Murashige and Skoog (MS) + ALB homogenate is a better medium for P. primulinum and P. glaucophyllum growth than media without banana homogenate. The highest values of plant height, leaf growth and root growth of P. primulinum with banana homogenate were 0.44 cm, 0.63 leaves, and 0.50 roots, respectively. The highest values of plant height and leaf growth of P. glaucophyllum were 0.75 cm and 1.90 leaves, respectively. Culture medium added banana homogenate was able to support the propagation of plants, some of which are returned to nature and others used for industrial purposes (conventionally cultivated by the community).

The Influence of Citric Acid on the Corrosion Process of Different Metallic Materials

Abstract The paper presents the results from a study of the corrosion behaviour of different metallic materials, such as copper, aluminium and OL 52 steel in the presences of various concentrations of citric acid added in neutral solution (Na2SO4 0.25 M). Citric acid (2-hydroxy-1, 2, 3-propanetricarboxylic acid) is among the most commonly utilized compounds in the food and beverage sectors. This non-toxic chemical can be derived from natural, renewable sources such as citrus fruits, pineapples, kiwis, raspberries, strawberries, and both black and red currants. Corrosion studies carried out previously demonstrated a mixed effect of citric acid, it can be a good inhibitor for aluminum alloys in a strongly acidic or strongly basic media as well as in neutral NaCl media, for low carbon-steel and copper in an acidic environment, but also, a good, accelerated corrosion agent in an alkaline solution for metals such as iron, copper, zinc and tin. Potentiodynamic polarization and chronoamperometry techniques were used in the experimental part of this paper to evaluate the inhibition efficiency of the citric acid in test solutions. Also, Tafel method for the kinetic parameters determination for studied corrosion process.

Assessing the mass-culture system and proximate content of Arthrospira maxima local for biogas and biohydrogen productions

Arthrospira maxima is a type of local cyanobacteria that has shown success in being grown massively in Indonesia. This research is aimed at looking at the resilience and ability to grow in outdoor conditions using cheap media and following environmental patterns in terms of temperature, sunlight and aeration. In specific purpose is utilization of the obtained biomass for biogas or biohydrogen production. Also, media optimization research from chemical pour grade analyzes into commercial types has been carried out at laboratory scale and field scale. The results show that at the scaling up process from laboratorial to outdoor condition the amount of biomass ratio has decreased by 2–10%, whereas proximate of protein has decreased from 46% to 38%, in contrast starch tends to increase from 10% to 23% and lipid was increase from around 9%–12%. Freshwater and marine water basic media also showing difference in ratio of biomass production and main proximate. The total calory and protein seems higher if A. maxima cultivate using marine water. Cultivation time outdoors turns out to be faster growth when compared to controlled conditions indoors. Biomass analysis results show that the largest content is protein, followed by carbohydrates and lipid. Considering the composition of the proximate, the cyanobacteria biomass tends to be used for biogas conversion rather than alcohol, due to the high protein with less carbohydrate content. Moreover, Arthrospira is cyanobacteria which is capable for producing heterocyst cells that can be excite gas. It was found the cyanobacteria release hydrogen gas around 54 μL/g wet biomasses/day mature culture. However, it should be remembered that this strain is still original or wild type, and can still be developed using both environmental and molecular manipulation approaches. Survival rate from laboratory scale to field scale shows that the microalgae is strong and worthy of consideration for industrial applications. Apart from that, high pH culture conditions are very good for removing contaminants. Also changing the media from pour analyses grade chemicals to commercial chemicals grade only reduces the biomass composition by 2–5% so it is worth considering for commercial applications. Testing various reactors to make biomass as needed with high productivity will be a challenge in the future.

Synthesis, Characterization and Analytical Study of New Azo Compounds for using as acid-base indictors

A diazotization method was used to synthesize new azo compounds, to which phenol was subsequently added to diazonium salt solution in basic medium at temperatures ranging from 0 to 5 °C and compounds were characterized by FT-IR, 1H-NMR, and 13C-NMR spectroscopy. The potential of the compounds as acid-base indicators was tested by determining their ionization and protonation constants at different pH levels (1 to 14) using a DMSO solution of the synthesized compounds. UV-Vis spectra shown as maximum wavelength (380-390 nm) observed at pH 1-7 occurs, indicating the cationic formula (protonated form of compound H2 and H4), another peak (470-530 nm) appears at pH 8-13, indicating the ionic formula (deprotonated form of compound H2 and H4), where for compound H5 observed at 560 nm at pH 1-7. Another peak appears 505 nm at pH 8-13 attributable to absorption the ionic formula (deprotonated form of compounds H5). Molecules H2, H4, and H5 showed distinct color changes when shifted to acidic and basic conditions. Furthermore, these compounds showed exceptional accuracy in drawing conclusions about the phenomenon.

Preparation and Characterization of Acid and Base Modified Fish Scales of Labeo Rohita and Their Application as an Adsorbent

The study is carried out to investigate the removal efficiency of the textile dye Congo Red (CR) on fish scales (FS) of Labeo rohita. Huge fish scales are dumped as waste from the fish markets and are not converted into valuable products. That is why a fish scale of widespread fish in Bangladesh Labeo rohita has been selected as an adsorbent in removing Congo red from an aqueous solution. In the present study, the effect of different parameters such as adsorption dosage, contact time, concentration of dye, and pH on the removal of CR were investigated. The maximum dye removal efficiency (88.53 %) was observed for 3g/100 mL of adsorbent at an initial concentration of 1×10-4 M and pH 8.80 after 60 minutes. Modification of the surface of the fish scales was carried out by using HCl and KOH. The surface of the adsorbents was characterized by FTIR spectroscopy. After 60 minutes of contact time, the percentage of adsorption for the acid and base-modified FS was 54.81% and 90.51% respectively. The higher intense FTIR spectra of the base-modified FS denoted the better efficiency of the adsorbent at the basic medium. The adsorption kinetics of CR on FS is studied by following the pseudo-first-order and pseudo-second-order kinetic model. Experimental results showed that fish scales of Labeo rohita have satisfying color removal efficiency and might be a better alternative to other adsorbents to detoxify industrial wastewater. A mechanism of adsorption of CR on FS has been proposed.

DIAGNOSTICS OF THE DEVELOPMENT OF INFORMATION AND DIGITAL COMPETENCE OF FUTURE OFFICERS

Formulation of the problem. Today the problem of developing information and digital competence (IDC) of future officers in the context of non-formal education and the problem of designing a diagnostic apparatus to measure such development is relevant. The paper aims to develop a diagnostic apparatus (criteria and indicators) to measure the development of information and digital competence of future officers Methods. To achieve this goal, we used the analysis and generalization of scientific sources, structural and logical analysis to identify and substantiate the indicators of the development of the IDC of future officers, as well as content analysis and comparative analysis to characterize the levels of development of the IDC of future officers. Results. To assess the levels of development of the IDC of future officers, the criteria (motivational and value, cognitive and activity) and the relevant indicators (the presence of motives, value attitudes for self-development, knowledge about IT & DT in general and in the industry, the ability to use DT and IT to solve professional problems) have been determined. The qualitative assessment of the indicators made it possible to characterize the levels of development of future officers' IDC. Each level (low, medium, and high) reflects a different degree of IDC development, and, accordingly, a different degree of development of motives, knowledge, and skills to use IT and DT in professional activities. A low level may be sufficient for basic tasks, but medium and high levels are critical for managing complex operations and adapting to the performance of professional duties. Conclusions. This diagnostic apparatus has been developed, and levels of development of future officers' information and digital competence have determined the ability to use modern technologies to perform official duties effectively. With the help of the diagnostic apparatus, it becomes possible to test the effectiveness of pedagogical models of future officers' IDC development.

Application of Anionic Hydrogels from Date Palm Waste for Dye Adsorption in Wastewater Treatment.

This work aimed to develop an anionic cellulose nanofiber (CNF) bio-adsorbent from date palm tree waste and to investigate its removal efficiency compared to cationic methylene blue dye from contaminated water. Date palm pulp was first prepared from date palm leaves through acid hydrolysis using H2SO4, followed by hydrolysis in a basic medium using KOH, in which the process completely removed the components of hemicellulose, lignin, and silica. To obtain anionic CNF, the resulting pulp was further treated with H2SO4, followed by centrifugation. Biogel formation of the CNF suspension was promoted by sonication, where its removal efficiency of methylene blue dye was studied as a function of dye concentration, temperature, contact time, and pH value. In this work, we investigated two isotherms, i.e., Langmuir and Freundlich. The Langmuir model's consistency with the experimental data suggests that the adsorption of methylene blue dye onto CNF is monolayer and surface-limited. The reported maximum removal efficiency of 5 mg/g at 60 °C indicates the optimal temperature for adsorption in this specific case. Additionally, a pseudo-second-order model and Elovich model were also utilized to obtain a better understanding of the adsorption mechanism, in which we found not just physical adsorption but also an indication of a chemical reaction occurring between methylene blue dye and CNF. According to the results, that pseudo-second-order model's consistency with the experimental data suggests that the adsorption of methylene blue (MB) onto CNF is rate-limiting step involving chemisorption between the two. The study reveals that CNF adsorbents derived from renewable natural waste sources such as date palm leaves can be effective in removing cationic contaminants such as methylene blue dye.

Eutectogel adhesives with underwater-enhanced adhesion to hydrophilic surfaces and strong adhesion in harsh environments

It has been a challenge to achieve strong adhesion strength for gel adhesives in water. In this study, a novel eutectogel adhesive is synthesized via one-step photoinitiated polymerization of N-vinylpyrrolidone (NVP) in deep eutectic solvent (DES). The abundant hydrogen bonding interactions and the hydrophilic polyvinylpyrrolidone network structure endow the eutectogel with excellent adhesion to both hydrophilic and hydrophobic surfaces in air and underwater. Moreover, for hydrophilic substrates, the underwater adhesion strength of the eutectogel adhesives is 1.3 times larger than that in air, demonstrating an underwater-enhanced adhesion effect. In contrast, for hydrophobic substrates, the underwater adhesion strength is lower than in air. Furthermore, strong adhesion performance is maintained even in boiling water, strong acidic medium, strong basic medium, and organic solvents. The experimental and simulation results have unveiled the underwater adhesion enhancement mechanism of the eutectogel. It is believed that the designed eutectogel will show great promise in the development of the next-generation of gel adhesives with underwater adhesion capabilities and high environmental adaptability.

Synthesis, Characterization and Molecular Docking Study of New 1,3,4-Thiadiazole Derivatives

In this study, a series of 5-(5-{(Z)-[(4-R1)methylidene]amino}-1,3,4-thiadiazol-2-yl)benzene-1,2,3-triol (L1-3), and 4-(5-{(Z)-[(4-R1)methylidene]amino}-1,3,4-thiadiazol-2-yl)benzene-1,2-diol (L4-6) compounds were synthesized, where R1 = 4-Nitro, 4-bromo, 4-chloro. The reaction between benzoic acid derivatives and hydrazinecarbothioamide in the basic medium gave the intended products with high yield and purity. The preparation of the compounds was confirmed by spectroscopic measurements in addition to physical properties. The biological properties of the prepared compounds were studied by molecular docking. The binding interaction between the new synthesized derivatives of 1,3,4-thiadiazole and the target, ADP-sugar pyrophosphatase, was studied. One of these 1,3,4-thiadiazole derivatives, 5-(5-{(Z)-[(4-nitrophenyl)methylidene]amino}-1,3,4-thiadiazol-2-yl)benzene-1,2,3-triol (L3) showed a high binding and coordination with its target. Molecular docking showed a docking score = −8.9 kcal/mol and MM-GBSA = −31.5 kcal/mol. The molecular docking estimation for the (L3) compound exhibited that four hydrogen bonds were created with NUDT5 Gene.

Palladium nanoparticles incorporated biogenic modified graphitic carbon nitride as an electrocatalyst for methanol oxidation reaction

This research explores palladium (Pd) nanoparticles supported on graphitic carbonitride (g-C3N4) as a cost-effective and CO tolerant catalyst towards electrocatalytic methanol oxidation reaction (MOR). The study delves into the green synthesis strategy, employing phytochemicals as reducing, capping and stabilizing agents. This approach aligns with environmentally friendly practices, steering away from hazardous chemicals and solvents commonly used in traditional synthesis methods. The synthesis involves the dispersion of Pd nanoparticles supported on graphitic carbon nitride (g-C3N4) modified by banana leaf extract [PdNPs@g-C3N4-BLE]. The obtained nanocatalyst is characterized using various spectroscopic and microscopic techniques. Further, the synthesized PdNPs@g-C3N4-BLE is utilized as electrocatalyst for methanol oxidation reaction (MOR) in basic medium (1 M KOH). PdNPs@g-C3N4-BLE shows satisfactory activity towards MOR with an onset potential of 0.834 V and current density of 6.795 mA/cm2 at 1.0 V.

Golden Guardians: Advanced pH Sensors with Built‐in Antimicrobial Defense

AbstractGold nanoclusters (Au NCs) capped with a small biomolecule, namely (+)‐norephedrine, (Au@Nore) display exceptional performance as fluorescent pH sensors. They display high emission quantum yield (ΦPL of ≈33% in strongly basic media); absence of nanocluster (NC) aggregation and/or induced rigidification of the organic shell; a linear dependency of their emission on the pH in the 8.2–9.5 range; and reversible pH sensing. In addition, excitation at 310 nm, where both the NC and the ligand absorb, enables ratiometric sensing. Studies on the fungus Candida albicans and bacterium Bacillus subtilis demonstrate that while Au@Nore do not cause any impact on the growth of the fungus, it inhibited the growth of the Bacillus, showing the lowest cell viability of 18% at the highest pH values via a mechanism of action involving the disruption of the bacterial wall.

Evaluation of chicken embryo extract and egg yolk extract as alternatives to basic cell culture medium supplement

BackgroundFetal calf serum (FCS), an existing cell culture supplement, is effective but has several drawbacks, including being expensive, requiring a lengthy process of production, and requiring a hard currency. With this in mind, we planned to evaluate chick embryo extract and egg yolk extracts in cell culture as alternatives to fetal calf serum (FCS).MethodsSpecific pathogen-free eggs were purchased from the National Veterinary Institute, Bishoftu, Ethiopia, and incubated in a humidified incubator at 37 °C for 11 days. Egg yolk extract (EYE) and chick embryo extract (CEE) were collected after the egg was opened with caution not to destroy the yolk sack or the chick embryo itself. Chick fibroblasts and Vero cells were cultured in minimum essential medium (MEM) supplemented with egg yolk extract or chick embryo extract at ratios of 0:10, 1:9, 2.5:7.5, and 5:5% fetal calf serum.ResultsFibroblast cell attachment was better in media supplemented with 5% CEE and 5% FCS. The confluency was also greater than 50% at this concentration. Vero cells cultured with 5% CEE and 5% FCS also exhibited very good cell attachment and a confluency of up to 70%. Viability and confluency were also observed at 5%:5% ratios of 50 and 70%, respectively.ConclusionThis investigation evaluated these two extracts as cell culture supplements and revealed promising results as alternatives to fetal calf serum. The limitation of this study is that it only used two cell types and additional cell lines, and different ratios should be tested. With the above findings, further research using different cell lines, ratios and conditions is warranted.

Osmotic energy harvesting using acrylic acid hydrogel PET membrane

In this study, we investigated the osmotic energy harvesting using a cation-selective membrane. The cation-selective membrane was synthesized by the incorporation of acrylic acid hydrogel in a porous support membrane. FTIR analysis and SEM images confirmed the presence of the acrylic acid hydrogel rods inside the porous support material. The exposure of the acrylic acid hydrogel PET (AP) membrane to a concentration gradient culminated in the generation of electric power. The AP membrane was evaluated in regard to the following parameters: EDiff, Io, Pmax and t+. The maximum power obtained with the membrane was 1.10 μW at the 40-fold concentration gradient (test area∽ 100 mm2). Increasing the concentration gradient increased the power output. However, a decrease in power output was observed after a certain value of the concentration gradient. An enhancement in power output was noted as the fraction of acrylic acid within the membrane was augmented. Additionally, the cation transference number also increased owing to a high charge density and a reduction in the mesh size. The AP membrane was also investigated in acidic and basic media. The time-dependent study revealed the superior chemical stability of the AP membrane.

Isomerization, Protonation, and Hydrolysis Properties of Naphthalimide-Containing Spiropyran in Aqueous Media.

Synthesis of spiropyrans exhibiting ring-opening/closing isomerization driven by external stimuli is a challenging subject for the development of molecular sensors. A napthalimide-containing spiropyran (1) promotes rapid isomerization between the spirocyclic (SP) form and ring-opened merocyanine (MC) form by the change in solvent polarity even under the dark condition at room temperature. In this work, the effect of water on the isomerization behavior of 1 was studied. The addition of water caused an MC-water H-bonding interaction and shifted the resonance MC structure to the zwitterionic form with a lower ground-state energy. The stabilized MC form promoted spontaneous SP → MC isomerization and increased the equilibrium MC concentration. The effect of pH on the behavior of 1 was also studied. In acidic-neutral media, protonation/deprotonation of the naphthalimide moiety led to rapid and reversible changes in the absorption spectra. In contrast, strongly basic media (pH > 12) promoted irreversible base-catalyzed hydrolysis of the alkene moiety.