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A dye mixture of Disperse red1 (DR1) and Janus green B (JGB) was prepared with different concentrations of the two dyes. The optical properties were studied for the two dyes and their mixtures in terms of the absorbance spectra. The direct optical energy gap in addition to the refractive index, extinction coefficient, dielectric constant and optical conductivity were estimated to the two dyes and their mixtures. The experimental energy gap was found to be 2.234 and 1.666 eV for DR1 and JGB respectively, while the values of the energy gaps for the mixtures were found to be ranging between these two values. On the other hand, the refractive index was found to be changed in a systematic way by changing the contents of the dye mixture. The same behavior was also observed for the dielectric constant and optical conductivity. The emission of the two dyes and their mixtures was studied in terms of fluorescence spectra using excitation wavelength of 300 nm where a change in the fluorescence intensity was observed by changing the contents of the mixture. Finally, TD-DFT simulations were performed for the two dyes and their mixture to study the electron density, electrostatic potential, energy gap and optical absorption spectrum and found to be compatible with the experimental measurements., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The recent investigation targets to use adapted carbon paste (CP) with copper nanoparticles (CuNs) operating in a phosphate buffer (PBS) medium with a pH range of 5.0-8.0, to synthesize a novel, susceptible, and simple electrochemical sensor for the detection of one of the most important drugs, vitamin B 6 . Copper (Cu) is one of the most three common essential trace elements found in the bodies of both humans and animals, along with iron and zinc for all crucial physiological and biochemical functions. Its properties, which are assessed using a variety of methods including scanning electron microscopy (SEM), cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS), have also drawn a lot of attention recently. We considered the effects of pH, buffer, scan rate, interference, and calibration curve. The susceptible electrode's linear calibration curve encompassed concentration values between 8.88 and 1000.0 µM. The calculated limits of detection and quantification were 32.12 and 107.0 µM, respectively. Furthermore, this method was established in real human urine samples and drug validation which have been shown satisfactory results for vitamin B 6 detection., (© 2024. The Author(s).)

Municipal wastewater treatment systems use the chemical oxygen demand test (COD) to identify organic contaminants in industrial effluents that impede treatment due to their high concentration. This study reduced the COD levels in tannery wastewater using a multistage treatment process that included Fenton oxidation, chemical coagulation, and nanotechnology based on a synthetic soluble COD standard solution. At an acidic pH of 5, Fenton oxidation reduces the COD concentration by approximately 79%. It achieves this by combining 10 mL/L of H 2 O 2 and 0.1 g/L of FeCl 2 . Furthermore, the author selected the FeCl 3 coagulant for the coagulation process based on the best results of comparisons between different coagulants. At pH 8.5, the coagulation dose of 0.15 g/L achieved the maximum COD removal efficiency of approximately 56.7%. Finally, nano bimetallic Fe/Cu was used to complete the degradation and adsorption of the remaining organic pollutants. The XRD, SEM, and EDX analyses proved the formation of Fe/Cu nanoparticles. A dose of 0.09 g/L Fe/Cu NPs, 30 min of contact time, and a stirring rate of 200 rpm achieve a maximum removal efficiency of about 93% of COD at pH 7.5. The kinetics studies were analyzed using pseudo-first-order P.F.O., pseudo-second-order P.S.O., and intraparticle diffusion models. The P.S.O. showed the best fit among the kinetic models, with an R 2 of 0.998. Finally, the authors recommended that technique for highly contaminated industrial effluents treatment for agriculture or industrial purposes., (© 2024. The Author(s).)

The mechanism of interaction between magnesite mineral and phosphoric acid (0.001-0.5 M) in addition to the determination of the protective properties for Ti alloy (working electrode) in phosphoric acid both with and without an inhibitor have been investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. Results of electrochemical tests show that the corrosion resistance of titanium alloy in phosphoric acid solution only increased and hydrogen production decreased by either decreasing acid concentration or increasing immersion time associated with the thickening of the oxide film formed on the alloy surface. On adding magnesite, the corrosion resistance of Ti alloy is enhanced by increasing the phosphoric acid concentration (0.001-0.5 M) due to the formation of sparingly soluble magnesium phosphate film on the alloy surface that inhibits the effect of increasing hydrogen evolution reaction due to the pH value decreases. The increasing adsorption behavior of the magnesite inhibitor and decreasing its diffusion were deduced from EIS measurements. Thus, the addition of 3% magnesite minimizes the corrosion by forming a new protective film (Mg 3 (PO 4 ) 2 ), which differs from the traditional passive film and prevents the effect of the increase of hydrogen evolution. The surface morphology and chemical composition of the tested alloy were determined using scanning electron microscopy (SEM), Fourier transform Infra-Red spectroscopy (FTIR), X-ray diffraction (XRD), X-ray Fluorescence (XRF) and In situ Raman spectroscopy., (© 2024. The Author(s).)

Poly methyl methacrylate-co-acrylonitrile [P(MMA-co-AN)] HB hybrid blend was first synthesized by precipitation polymerization and characterized by static light scattering. With a thickness of 200 ± 5 nm, the hybrid nanocomposite of [P(MMA-co-AN)/ZrO 2 ] HNC thin films were fabricated by spin coating method. X-Ray diffraction studies showed a monoclinic cell structure with an average crystalline size of 180 nm for the fabricated films. An improvement in the optical properties were figured out when fluorescein dye was doped in the hybrid nanocomposite. Where the optical energy gap was decreased from 4.31 to 4.025 eV for fluorescein doped hybrid nanocomposite. While a possible energy transfer between ZrO 2 and fluorescein was investigated in the laser photoluminescence spectra. DFT-CASTEP simulations were deployed to calculate the theoretical optical properties for the molecules under consideration. The structural and optical simulations of [P(MMA-co-AN)/ZrO 2 ] HNC were found to match the experimental data. Molecular docking studies of [P(MMA-co-AN)/ZrO 2 ] Iso against the main protease of novel corona virus COVID 19 (PDB code 6LU7 Hormone) showed an interesting interaction., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Borate antimony glass doped with vanadium oxide V 2 O 5 encoded into a [BSV glass system] was prepared with the traditional melt quenching technique. The Nickel ferrite [NiFe 2 O 4 ] was prepared using Flash auto-combustion and mixed at a fixed ratio of 0.05 gm into the glass matrix to form a BSV- composite glass system [BSV / NiFe 2 O 4 ], which was also prepared using the traditional melt quenching technique. The X-Ray diffraction pattern was used to characterize the glass samples and indicated their amorphous structure, with different structure phases for different levels of V 2 O 5 content. Ranging from 200 to 1100 nm, UV-Vis spectroscopy was used to study the optical properties of the samples. The glass was found to absorb electromagnetic waves with wavelengths lower than 500 nm, while the energy gap decreased from 2.46 eV for 0.1 mol% V 2 O 5 to 2.39 eV for 0.5 wt% V 2 O 5 . The Urbach energy also had the same behavior, and decreasing from 0.226 to 0.217 eV. On the other hand, the refractive index increased when V 2 O 5 was added. The thermal characteristics of a [BSV / NiFe 2 O 4 ] system, such as, glass transition temperature [Formula: see text], onset temperature [Formula: see text], crystallization temperature [Formula: see text] and melting temperature [Formula: see text] were studied using a Differential Scanning Calorimeter. Using continuous and pulsed laser radiation, a [BSV-0.1 V 2 O 5  / NiFe 2 O 4 ] sample was exposed to laser irradiation to observe its effect on the optical features of the glass. Laser irradiation significantly changed the absorbance spectrum, while the energy gap decreased as time increased. The pulsed laser was found to have a more power-full and uniform effect compared to continuous laser. Time-dependent density function theory was used to optimize the geometrical structure of the glass and study the effect of the formation of 4- coordinate boron atoms on its properties., (© 2024. The Author(s).)

A biosensitive analysis method development and validation was performed for accurate and rapid quantification of cefdinir (CDR) in human plasma by a liquid chromatography-tandem mass spectrometry technique coupled with electrospray ionization. Analysis was carried out using a C18 column with a flow rate of 1.0 mL/min and operating temperature of 30.0 ± 1°C. The drug was eluted by optimizing the m/z ratios of 396.20 → 227.20 and 428.17 → 241.10, for cefdinir and IS (internal standard), respectively. The intraday precision (%CV) for Cefdinir ranged from 2.8% and 6.7% as lower limit of quantification of quality control (LLOQ QC) and higher level of quantification of quality control (HQC QC), respectively, whereas these value were found to be as 3.0% and 5.6% for LLOQ and HQC, respectively after interday precision. Moreover, accuracy ranged from 107.70% (HQC QC) to 95.5% (LLOQ QC). The extraction mean recovery was found to be 83.91 ± 6.0% for cefdinir and 76.7 ± 6.23% for IS. The drug was stable throughout the analysis period. It was possible to analyze several plasma samples every day since each sample took <2.5 min to run. The method demonstrated successful quantification of CDR in human plasma, followed by pharmacokinetic profiles that were simple, accurate, sensitive and cost-effective., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Stability-indicating methods are awesome tools to ensure the safety and efficacy of active pharmaceutical ingredients (APIs). An accurate comparative study involving the use of potentiometric sensors for the determination of bromazepam (BRZ) in the presence of its main product of degradation and impurity was performed by the fabrication of two membrane electrodes. A screen-printed electrode (SPE) and a solid-contact glassy carbon electrode (SCE) were fabricated and their performance optimized. The fabricated sensors showed a linear electrochemical response in the concentration range 1.0 × 10 -6 M to 1.0 × 10 -2 M. The electrodes exhibited Nernstian slopes of 59.70 mV/decade and 58.10 mV/decade for the BRZ-SPE and BRZ-SCE membrane electrodes, respectively. The electrochemical performance was greatly affected by the medium pH. They showed an almost ideal electrochemical performance between pH 3.0 and pH 6.0. The fabricated membranes were applied successfully for the quantification of BRZ in the presence of up to 90% of its degradation product. Moreover, a successful application of the fabricated electrodes was performed for the sensitive and selective quantification of BRZ in its tablet form without any pretreatment procedure.

Endophytic and rhizospheric bacteria isolated from halophytic plants support their host to survive in hyper-saline soil. These bacteria are also known to produce various enzymes with potential industrial applications. In this study, the endophytic and rhizospheric bacteria were isolated from Arthrocnemum macrostachyum collected from Karachi, Pakistan, and their ability to produce various extracellular enzymes was assessed using commercial and natural substrates. In total, 11 bacterial strains were isolated (four endophytic; seven rhizospheric). Bacillus was found to be the most abundant genus (73%), followed by Glutamicibacter (27%). The isolates including Glutamicibacter endophyticus and Bacillus licheniformis are reported for the first time from A. macrostachyum . All of the isolates were capable of producing at least two of the five industrially important hydrolytic enzymes tested, i.e., xylanase, cellulase, amylase, pectinase, and lipase. Lipase production was found to be highest among the isolates, i.e., up to 18 IU mL -1 . Although most of the isolates could grow at a wide range of temperatures (4-55 °C), pH (1-11), and salt concentrations (2-12%), under extreme conditions, very little growth was observed and the optimal growth was recorded between 2% and 6% NaCl, 25 and 45 °C, and 7 and 9 pH. Our results suggest that these isolates could be potential producers of enzymes with several biotechnological applications.

A novel environmental nano-catalyst based on zeolite (ZE) adjusted with carbon nanotube/silver nanoparticles (Ag/CNT) ornamented carbon paste electrode (CPE) is used for electrochemical oxidation of propylene glycol (PG) in 0.5 M H 2 SO 4 solution. The techniques like cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) are utilized to achieve the catalytic activity performance. Surface characteristics are achieved by means of scanning electron microscope (SEM) and Energy dispersive X-ray analysis (EDX) techniques. Enhancing the loading magnitude of CNT into catalyst's ingredient can meaningfully develop the catalytic activity of the electrocatalyst towards propylene oxidation. The impact of altering the concentration of propylene glycol and the scanning rate on the resulting electrocatalyst performance during the oxidation cycle is considered. Chronoamperograms present an amplify of the steady state oxidation current density values after addition of these nano-catalysts. A promising catalytic stability of nano-catalyst has been achieved in electing its use for propylene glycol electro-oxidation in fuel cells applications., (© 2022. The Author(s).)

Accurate and precise application of ion-selective electrodes (ISEs) in the quantification of environmental pollutants is a strenuous task. In this work, the electrochemical response of alendronate sodium trihydrate (ALN) was evaluated by the fabrication of two sensitive and delicate membrane electrodes, viz. polyvinyl chloride (PVC) and glassy carbon (GC) electrodes. A linear response was obtained at concentrations from 1 × 10 -5 to 1 × 10 -2 M for both electrodes. A Nernstian slope of 29 mV/decade over a pH range of 8-11 for the PVC and GC membrane electrodes was obtained. All assay settings were carefully adjusted to obtain the best electrochemical response. The proposed technique was effectively applied for the quantification of ALN in pure form and wastewater samples, acquired from manufacturing industries. The proposed electrodes were effectively used for the determination of ALN in real wastewater samples without any prior treatment. The current findings guarantee the applicability of the fabricated ISEs for the environmental monitoring of ALN.

Monitoring and quantification of active pharmaceutical ingredients (APIs) in the environment constitute important and challenging tasks, as they are directly associated with human health. Three commonly used proton pump inhibitors (PPIs), namely, omeprazole sodium (OMP), pantoprazole sodium (PNT), and lansoprazole sodium (LNZ) are well separated and quantified using ultra-performance liquid chromatography (UPLC) in pharmaceutical industrial wastewater. The separation of the studied drugs was performed on a stationary phase with a Waters TM column (100 × 2.1 mm, 1.7 µm). The mobile phase was composed of methanol:0.05 M potassium dihydrogen phosphate buffer (adjusted to pH 7.5 using NaOH) (50:50, v / v ). The elution process was done in gradient mode by changing the relative proportions of the mobile phase components with time to get an optimum separation pattern. The flow rate of the developing system was adjusted to 0.8 mL/minute. Detection of the separated drugs was performed at 230 nm. The studied drugs were quantified in the concentration range of 10-200 ng/mL for all drugs. The cited method was fully validated according to the international conference on harmonization (ICH-Q2B) guidelines, then it was applied successfully for quantification of the studied PPIs in real wastewater samples after their solid phase extraction (SPE).

A series of symmetric molecules incorporating aryl or pyridyl moieties as central core and 1,4-substituted triazoles as a side bridge was synthesised. The new compounds were investigated as lactate dehydro-genase (LDH, EC 1.1.1.27) inhibitors. The cancer associated LDHA isoform was inhibited with IC 50  = 117-174 µM. Seven compounds exhibited better LDHA inhibition (IC 50 117-136 µM) compared to known LDH inhibitor - galloflavin (IC 50 157 µM).

A new sensitive, rapid and simple spectrofluorimetric method was utilized for the assessment of velpatasvir (VPS) in its bulk form as well as in its combined tablet with sofosbovir (SFV). The technique relies on measuring the native fluorescence of VPS in methanol at 385 nm and 400 nm after excitation at 295 nm. The fluorescence-concentration plots were rectilinear through the range of 2.0-20.0 ng mL -1 at both emission maxima with lower detection limits of 0.146 ng mL -1 and 0.378 ng mL -1 , and lower quantification limits of 0.444 ng mL -1 and 1.147 ng mL -1 at 385 nm and 400 nm, respectively. The proposed method was appropriately used for the analysis of VPS in its commercial tablet formulation and the results were in good agreement with those achieved with the applied comparison method., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Two signal processing methods, namely, Continuous Wavelet Transform (CWT) and the second was Discrete Fourier Transform (DFT) were introduced as alternatives to the classical Derivative Spectrophotometry (DS) in analysis of binary mixtures. To show the advantages of these methods, a comparative study was performed on a binary mixture of Naltrexone (NTX) and Bupropion (BUP). The methods were compared by analyzing laboratory prepared mixtures of the two drugs. By comparing performance of the three methods, it was proved that CWT and DFT methods are more efficient and advantageous in analysis of mixtures with overlapped spectra than DS. The three signal processing methods were adopted for the quantification of NTX and BUP in pure and tablet forms. The adopted methods were validated according to the ICH guideline where accuracy, precision and specificity were found to be within appropriate limits., (Copyright © 2017. Published by Elsevier B.V.)

A rapid, simple and accurate micellar HPLC-method was adopted and validated for concurrent quantification of naltrexone hydrochloride (NTX) and bupropion hydrochloride (BUP). The proposed method was conducted on RP-18 LiChrosorb® column (150 mm × 4.6 mm i.d. 5-µm particle size) at 25 °C, as a stationary phase and a mixture of 0.175 M sodium dodecyl sulphate (SDS), 0.3% triethanolamine (TEA) and 12% n -propanol in 0.02 M ortho (o)- phosphoric acid of pH 3.5 as a developing system. It was pumped at a flow rate of 1.2 mL/min, with ultraviolet detection at 210 nm. The linearity ranges were 0.5-15.0 µg/mL and 1.2-18.0 µg/mL, with detection limits of 0.10 and 0.31 µg/mL and quantification limits of 0.30 and 0.93 µg/mL for NTX and BUP, respectively. The studied drugs were successfully quantified by applying the proposed method in their co-formulated tablet. The cited method was also applied for in-vitro quantification of BUP in spiked human urine without prior extraction.

This article reports the optical properties such as absorption profile, molar absorptivity, fluorescence profile and photo-physical parameters such as dipole moment, oscillator strength, fluorescence quantum yields, fluorescence lifetimes, laser performance and finally photostability of 2,5-Bis(5-tert-butyl-benzoxazol-2-yl)thiophene (BBOT),1,4-Bis(5-phenyl-2-oxazolyl)benzene (POPOB), 5-diphenyel-oxazole (PPO) laser dyes in different restricted hosts. (BBOT), (POPOB) and (PPO) are embedded in transparent silica-based nanoporous sol-gel glass and copolymer matrix of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA). The absorption and fluorescence properties of these laser dyes in sol-gel glass matrices are compared with their respective properties in copolymer host. In case of sol-gel matrix, all dyes had higher quantum yields as well as lasing wavelength maxima. The laser performances as well as the photostability of these laser dyes in sol-gel glass displayed senior behavior compared with (MMA/ HEMA) copolymer samples upon using nitrogen laser (337.1 nm) as pumping energy.

Realistic implementation of ion selective electrodes (ISEs) into environmental monitoring programs has always been a challenging task. This could be largely attributed to difficulties in validation of ISE assay results. In this study, the electrochemical response of amoxicillin trihydrate (AMX), ciprofloxacin hydrochloride (CPLX), trimethoprim (TMP), and norfloxacin (NFLX) was studied by the fabrication of sensitive membrane electrodes belonging to two types of ISEs, which are polyvinyl chloride (PVC) membrane electrodes and glassy carbon (GC) electrodes. Linear response for the membrane electrodes was in the concentration range of 10 -5 -10 -2  mol/L. For the PVC membrane electrodes, Nernstian slopes of 55.1, 56.5, 56.5, and 54.0 mV/decade were achieved over a pH 4-8 for AMX, CPLX, and NFLX, respectively, and pH 3-6 for TMP. On the other hand, for GC electrodes, Nernstian slopes of 59.1, 58.2, 57.0, and 58.2 mV/decade were achieved over pH 4-8 for AMX, CPLX, and NFLX, respectively, and pH 3-6 for TMP. In addition to assay validation to international industry standards, the fabricated electrodes were also cross-validated relative to conventional separation techniques; high performance liquid chromatography (HPLC), and thin layer chromatography (TLC)-densitometry. The HPLC assay was applied in concentration range of 0.5-10.0 μg/mL, for all target analytes. The TLC-densitometry was adopted over a concentration range of 0.3-1.0 μg/band, for AMX, and 0.1-0.9 μg/band, for CPLX, NFLX, and TMP. The proposed techniques were successfully applied for quantification of the selected drugs either in pure form or waste water samples obtained from pharmaceutical plants. The actual waste water samples were subjected to solid phase extraction (SPE) for pretreatment prior to the application of chromatographic techniques (HPLC and TLC-densitometry). On the other hand, the fabricated electrodes were successfully applied for quantification of the antibiotic residues in actual waste water samples without any pretreatment. This finding assures the suitability of the fabricated ISEs for environmental analysis.

Three sensitive, selective, and precise stability indicating methods for the determination of the X-ray contrast agent, diatrizoate sodium (DTA), in the presence of its acidic degradation product (highly cytotoxic 3,5 diamino metabolite) and in pharmaceutical formulation were developed and validated. The first method is a first derivative (D1) spectrophotometric one, which allows the determination of DTA in the presence of its degradate at 231.2 nm (corresponding to zero crossing of the degradate) over a concentration range of 2-24 μg/mL with mean percentage recovery 99.95±0.97%. The second method is the first derivative of the ratio spectra (DD1) by measuring the peak amplitude at 227 nm over the same concentration range as D1 spectrophotometric method, with mean percentage recovery 99.99±1.15%. The third method is a TLC-densitometric one, where DTA was separated from its degradate on silica gel plates using chloroform:methanol:ammonium hydroxide (20:10:2 by volume) as a developing system. This method depends on quantitative densitometric evaluation of thin layer chromatogram of DTA at 238 nm over a concentration range of 4-20 μg/spot, with mean percentage recovery 99.88±0.89%. The selectivity of the proposed methods was tested using laboratory-prepared mixtures. The proposed methods have been successfully applied to the analysis of DTA in pharmaceutical dosage forms without interference from other dosage form additives. The results were statistically compared with the official US pharmacopeial method. No significant difference for either accuracy or precision was observed., (Copyright © 2014 Elsevier B.V. All rights reserved.)