Search

Hydrotalcite samples were prepared in the form of powder and/or sol under different conditions and characterised by various techniques. A suitable system of liquid carriers consisting of perfluoroheptane, isopropanol, and water (PFH-IPA-H2O) was chosen to apply HTlcs as deacidifying agents on paper. The areas of miscibility and immiscibility in the PFH-IPA-H2O system were determined at a temperature of 25 °C. The properties of HTlcs dispersed in the prepared solvent were measured. The size of the particles was determined by optical microscopy with image analysis. The average particle size ranges from 1 µm to 2 µm. The settling speed of particles in the prepared colloidal systems was monitored using turbidimetry. Sols in the mixture of solvents had uniformly dispersed particles that settled slowly. The effect of the prepared colloidal HTlcs dispersions on the properties of the paper, specifically the pH of its surface, was also tested. Hydrotalcites in the form of a sol with a ratio of magnesium to aluminium of 5:1 were found to be promising candidates for deacidification. The use of surfactant additives in the preparation of HTlcs did not positively affect the properties of the paper.

This study aimed to investigate the effects of boron compounds on cellulose fibers during recycling. Three recycling stages were conducted, applying boric acid and borax to bleached papers. Physical, mechanical, and optical properties were measured after each process. The highest water absorption (218 g/m2) was observed in test papers from the second recycling stage using 10% borax-treated pulps (10Bx2). Boric acid treatment notably improved burst strength, with the highest value (3.94 kPa m2/g) in the first recycling stage with 5.0% boric acid treatment (5Ba1). The highest tensile strength (49.48 Nm/g) occurred in the first recycling stage with 5.0% boric acid treatment, while the lowest (17.41 Nm/g) was in the second recycling stage (5Bx2) with 5.0% borax treatment. Tear strength exhibited different trends from burst and tensile strength, with notable improvements using 5.0% and 10% boric acid and 10% borax treatments on recovered cellulose fibers. The highest tear strength (9.20 Nm2/g) was achieved with 5.0% boric acid treatment (5Ba2) in the second recycling stage, followed by 8.21 Nm2/g with 10% boric acid treatment (10Ba1) in the first recycling stage. Tear strength trends differed from burst and tensile strength properties, regardless of treatment conditions.

This study aims to study the possibility of distinguishing the UV–Vis–NIR spectra of filamentous fungi on a paper substrate from the background. Model samples of five filamentous fungi were used: Alternaria alternata, Aspergillus niger, Cladosporium herbarum, Penicillium chrysogenum, and Trichoderma atroviride. The model samples were cultivated on paper substrates, and two methods, cross-validation (CV) and principal component analysis (PCA), were utilised to compare their spectra with the reference background spectra. The results of the CV analysis indicated that certain combined spectra sets of Cladosporium herbarum, Penicillium chrysogenum, Trichoderma atroviride, Aspergillus niger, and Alternaria alternata, at specific surface concentrations, exhibited two active components, signifying distinguishable differences from the background spectra. Additionally, the score scatter diagrams derived from PCA revealed clusters of samples, further confirming the distinguishability of the filamentous fungi spectra from the background. However, for Trichoderma atroviride, the scatter diagram demonstrated a relatively large scattering of points, impeding the resolution of spectra with a surface concentration of 2 105cm−2due to measurement inaccuracies. Based on the combined results of CV and PCA, the study concluded that the lower threshold of measurability for UV–Vis–NIR spectra varied among the different filamentous fungi. For example, Cladosporium herbarum, Penicillium chrysogenum, and Trichoderma atrovirideexhibited a threshold around a surface concentration of 2 106cm−2, while Aspergillus nigerhad a threshold around 2 105cm−2, and Alternaria alternatahad a threshold around 2 103cm−2. In summary, this research provides insights into the distinguishability of filamentous fungi spectra on the paper substrate from background spectra using spectral analysis techniques, offering potential applications in fungal identification and characterisation.

Abstract: In this study, two important biomarkers, namely glucose and uric acid, were detected in different biological fluids using a highly sensitive and selective chitosan-/nano-based electrochemical microfluidic paper-based analytical device (µPAD). A graphite/chitosan/polyethylene glycol (PEG) mixture was used as bare working electrode and counter electrode with silver ink being used as quasi-reference electrode. Graphene, multiwall carbon nanotubes, and Fe3O4nanoparticles were used to improve sensitivity as well as selectivity of the working electrodes. The developed chitosan-/nano-based microfluidic analytical system showed apparent redox peaks, and all the three types of nanomaterials improved the performance of the bare graphite/chitosan/PEG electrode with the Fe3O4-modified electrode exhibiting the sharpest signals with the highest selectivity. The linear ranges of glucose and uric acid were 0.01–30 mM and 0.05–15 mM, respectively, where the limits of detection (LOD) were 5 µM and 20 µM for glucose and uric acid, respectively. In comparison with most of previous data reported on μPADs and due to high surface area/volume ratio of NPs and faster electron transfer promoted by chitosan and NPs, the better LODs were found in the current study. The fast, efficient, and low-cost µPADs were successfully applied to highly sensitive and selective detection of glucose and uric acid in serum and urine samples and noninvasive glucose detection in tear samples. Graphic abstract:

Graphical abstract:

Two simple and inexpensive colorimetric captures on paper methods using PhotoMetrix PRO®Application of smartphone for the determination of flutamide (FA), an anti-prostate cancer drug, in pharmaceuticals are presented. The analytical procedure involves the conversion of FA to a free base form of flutamide by reduction, treatment with acetylacetone to obtain a Schiff base, and use of chromatographic paper to spot and capture the colored products of various analyte concentrations. Method-A is based on univariate vector RGB analysis to measure the color intensity of the Schiff base. Method-B on the other hand performed a multivariate partial least square analysis of the same Schiff base. Both methods showed a linear correlation over the range of 3–600 μg/ml reduced FA with respect to the measured intensity. For Method-A, the reported limit of detection and quantification are 0.75 μg/ml and 2.09 μg/ml, respectively. The regression coefficients are 0.986 and 1.000, respectively, for Method-A and B. The validation of the proposed methods was done concerning linearity, accuracy, precision, sensitivity, robustness, and ruggedness according to the current guidelines of ICH. The mean recovery of FA by Method-A (97.9 ± 2.04%) and Method-B (98.9 ± 1.65%) is comparable to the reference method (100.31 ± 0.406%). The accuracy and precision of the developed methods are confirmed by the calculated t- and F-values, which do not exceed the tabulated values at a confidence level of 95%. Thus, these methods can be successfully used as routine analytical methods for the quantification of FA in quality control laboratories.

Abstract: Tissue paper was the only paper grade whose consumption increased during 2020 in Europe. In a highly competitive context, this work explores a strategy based on bisacrylamide cross-linkers and poly(vinyl alcohol) (PVA), seeking to enhance the water uptake of pulps for tissue paper and the key properties of the resulting tissue sheets: water absorption capacity, capillarity, softness, porosity, and strength. For that, α-cellulose from cotton and a kraft hardwood pulp, in parallel, were reacted with N,N’-methylenebisacrylamide, both in the absence and in the presence of PVA. The water desorption rate of the modified polymers was monitored. Pulp blends were then mixed with a conventional softwood pulp (30%) to prepare laboratory tissue paper sheets (20 g m–2). For cotton cellulose, cross-linking with PVA more than doubled the water uptake, up to 7.3 g/g. A significant enhancement was also obtained in the case of pulps, up to 9.6 g/g, and in the case of paper, to 11.9 g/g. This improvement was consistent with a drastic increase in porosity, and it was not detrimental to paper strength. Graphical Abstract:

This work investigated the feasibility of membrane filtrations such as reverse osmosis (RO) in treating whitewater from a pulp and paper mill due to thermo-mechanical pulping. The effects of pH and removal mechanisms of silicon by the membranes during treatment were discussed. Their individual performance in removing target compound was critically evaluated and compared to those of previous studies. It is found that membrane treatment could remove SiO2from the wastewater samples. With 200 mg/L of initial concentration at pH 11 and 10 bar of pressure, 80% and 85% of silicon could be removed when applying ultrafiltration (UF) or nanofiltration (NF) membrane for 12 h. RO achieved an almost complete removal of target pollutant at 10 bar under identical conditions. Treated effluents, resulting from the membrane filtration, could comply with the maximum effluent limit of lower than 50 mg/L imposed by local legislation. Hence, further treatments are unnecessary.

The X-ray diffraction internal standard method can quantitatively determine the ash content of paper, but the requirements for the experimental environment are high, the determination is not convenient and the cost is high, and it is difficult to be widely used in the papermaking enterprises. In order to determine the total ash and its components of the single filler paper samples, and meet the ash determination requirements of papermaking enterprises, the continuous X-ray method is proposed. In this paper, an X-ray tube is used as the radiation source and an ionization chamber is used as the detector. Through polynomial fitting of the total ash and voltage logarithm ratio of the single filler paper samples, the mathematical model of total ash is established; the total ash and its components content of paper are calculated according to the mathematical model of total ash and the Beer–Lambert law deformation formula; the total ash and its components content of paper are verified by the burning method. The research results show that the total ash error of the single filler paper samples is less than 4%, and the ash component error is less than 5%.

The properties of crystal violet lactone (CVL), currently the most commonly used color developer in carbonless papers, were studied. The hypothesis that CVL exhibits different properties in the carbonless and in the office papers was verified, as well as the CVL´s ability to luminesce in the IR region. Furthermore, the impact of thermal and light aging on some physical and chemical properties of the copies was observed. The changes were monitored by observing the IR luminescence at several wavelength ranges. Visual, colorimetric and structure differences between the copies made on the carbonless and the office paper were analyzed. The surface structure of the carbonless paper was analyzed using SEM–EDS.

A simple electrochemical approach has been strategically developed for in situ generations of ZnO nanoparticles using Zn rods as electrodes and hydrogen peroxide as the oxidant without the formation of any by-product. These ZnO nanoparticles were extended for remediation of pollutants present in paper mill effluents, and separation efficiency was found to be above 90% for hydrocarbons, 92% for lignin, 99% for phenol, and 93% of chemical oxygen demand (COD), as confirmed by gas chromatography-mass spectrometry and COD analysis. It was also observed that the experimental setup could successfully remove 99% of the color from the sample. These ZnO nanoparticles have been proven in the past to be antibacterial and were explored for its ability to inhibit the growth of both Gram-positive and Gram-negative bacteria in the effluent samples after the removal of toxic pollutants. Therefore, we proposed an electrochemical reaction for the in situ synthesis of ZnO nanoparticles for remediation of paper mill effluent as well as inhibit the bacterial growth in the treated effluent sample.

Abstract: This study presents a review conducted to critically evaluate the microbial fabrication and its subsequent effect on arsenic contamination in soil. Taking into consideration the global situation, the sources of arsenic, the microbial arsenic pathways and the impact of arsenic contamination on soil have been defined. Different published studies highlighted the biochemical and physiological molecular aspects of arsenic and evaluated their impacts on soil; in the current paper, the sources and extent of arsenic contamination and the translocation and speciation from microbes to soil are illustrated. This study also discusses the forms of water-soluble arsenic and whether these are more toxic than insoluble forms, as previously reported. In addition, this paper briefly illustrates the sources and coverage of arsenic contamination and arsenic speciation in contaminated soil globally. Some vital research findings are also discussed which relate to the scientific exploration of microbial arsenic systems in contaminated soil. Graphic abstract:

Benzene vapor is notoriously known to induce adverse human health, which plays a definite role in the deformation of cells. Various advanced adsorbents from lignocellulosic precursors have emerged as cheaper alternatives to the green process for the adsorption of gaseous benzene. In this paper, the prominence mainly benzene vapor removal with lignin-based adsorbent in the adsorption technology has investigated the textural, morphology, and chemical characteristics of activated carbon synthesized from Fraxinus excelsiorL. seeds, a lignocellulosic biomass waste. Chemically starting HCl and KOH in the N2atmosphere was adopted, contributing to the porous carbon material's well-developed porosity and surface chemistry. Also, carbonaceous materials were investigated by Brunauer–Emmet–Teller (BET), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and X-ray diffraction. Herein, the optimum way for producing activated carbon was recognized to be: activation temperature of 800 and 700 °C in line with an impregnation weight ratio of samples to HCl 1:2 and KOH 1:3 for 2 h activation time as FE7AC and FE22AC, which have resulted in 676 m2/g and 0.39 cm3/g; 734 m2/g and 0.48 cm3/g of BET surface area and total pore volume, respectively. The SEM observations exhibited advanced high porosity development formed by oxidation–reduction reaction, while FTIR confirmed the presence of various surface functional groups. Moreover, benzene became more tremendously facile for four ambient temperatures (20, 25, 30, and 35 °C) and until 200 min contact time. The tremendous values varied from 96 to 224 mg/g and 122 to 286 mg/g depending on lignin-based adsorbent amounts as 0.5 or 1 g and an initial benzene concentration of 100 mg/m3by using FE7AC and FE22AC. The main innovation of this paper is exciting to assist recent paths for optimizing air filtration procedures under actual environmental circumstances, particularly regarding its compatibility with the benzene molecular structure of FE22AC. The paper concludes that the performance of the FE22AC can be enhanced via improvements in its surface properties for a wide array of actual benzene concentrations from gaseous applications.

Fluorescence-based materials that are affordable and easy to use for commercial anti-counterfeiting applications are in high demand. While exploring new fluorescent pigments, a pyrene-naphthalimide Schiff base, 5-hydroxy-2-((pyren-1-ylmethylene)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione (NHPY) with yellow fluorescence under UV light was synthesized. An eco-friendly flexographic ink prepared with NHPY as the pigment was coated on a UV dull paper and further printed on security paper as well as packaging papers and boards. When exposed to UV light, the printed samples showed yellow fluorescence. The light fastness, gloss, colorimetric results, and abrasion resistance of the printed samples proved that NHPY is a suitable fluorescent pigment for security printing applications.

Surface-enhanced Raman scattering (SERS) has been widely applied in various fields due to its high sensitivity and rapid response capability. In this paper, a MIL-101(Fe)@Ag composite SERS substrate was prepared using photoreduction method. The synthesized MIL-101(Fe)@Ag composite substrate combines the localized surface plasmon resonance properties of silver nanoparticles and the high adsorption capacity of metal–organic frameworks. MIL-101 (Fe)@Ag composite substrate was characterized by FTIR, UV and SEM. The SERS activity of the composite substrates was characterized by measuring the Raman signals of PATP. The detection limit of the substrate for PATP was 10–8M, with a relative standard deviation of only about 5.3%, indicating good SERS effect and reproducibility of the substrate. Finally, the prepared substrate was applied for formaldehyde detection, with a detection limit of 10–9M. Principal component analysis was used for quantitative analysis of formaldehyde. This work proposes a simple method for synthesizing MIL-101(Fe)@Ag composite substrates with high SERS performance and uniformity and establishes a rapid detection method for formaldehyde using this substrate, which has great application prospects.

Development of effective methods for analyzing hypochlorite is of great significance due to the crucial role of hypochlorite in live organisms, as an endogenously produced reactive oxygen species (ROS) in the human immune system. In this paper, a novel fluorescent probe based on 6-methylthiocoumarinyl formate was designed and synthesized in one step for detection of hypochlorite in MeCN/PBS (8:2, v/v, pH 7.4) medium. The probe showed high specificity for hypochlorite over other competitive ROS analytes, extreme large Stokes shift of 265 nm, rapid response to hypochlorite within 20 s, low detection limit of 1.57 μM, and a wide applicable range of pH 3–10. The sensing mechanism was demonstrated to be based on oxidation of methyl phenyl sulfide to sulfoxide by hypochlorite. The probe may have extensive application for selective and convenient detection of hypochlorite due to its multiple advantages.

Accurate estimation of CO2-brine Interfacial Tension (IFT) is of great importance since it is required to model the residual/capillary trapping of CO2in geological formations. In this paper, a novel correlation is proposed based on the classical orthogonal polynomials to estimate the CO2-brine IFT of monovalent salts with common anion. To do so, CO2-brine IFT samples composed of samples from the literature and experimentally measured values using an in-house high-pressure high-temperature IFT measurement device were collected within a wide range of temperatures, pressures, and salinities. The utilized brines included NaCl and KCl salts. Then, a predictive model was developed based on the Group Method of Data Handling approach as a function of temperature, pressure, and ionic strength. The proposed method was compared with four methods from the literature in terms of average absolute percentage error (AAPE), coefficient of determination R2, histograms of error, and percent error plots. Results showed the superiority of the proposed method over other methods with an AAPE of 9.85 and R2of 0.719. Also, it was shown that the proposed method did not produce too large errors, contrary to other methods. Therefore, the proposed method can be used reliably as a tool for CO2-brine IFT estimation in CO2storage projects.

Hydrodynamic cavitation (HC), a common phenomenon that can produce local excessive temperature, high pressure and large amount of energy. It has been found that, when applied to water treatment, it can effectively act on refractory organic matter in wastewater through thermal decomposition and water molecular action to produce free radicals. In this paper, the basic theory of cavitation and the research achievements on cavitation reactor are systematically introduced. The existence of physical and chemical effects is revealed by discussing the mechanism of cavitation generation. The effects of geometric parameters as well as operational parameters on cavitation performance are described. In addition, HC is more cost-effective coupled with other advanced oxidation processes (AOPs) than HC alone. Finally, this paper puts forward the existing problems in this field, and predicts the future development direction and research trend, which has reference value for the further study of HC phenomenon and its application.

The separation of chalcopyrite and pyite is not fully solved, and thus more efficient depressants are still needed in industry. This paper used potassium permanganate (KMnO4) as a pyrite depressant to separate pyrite from chalcopyrite. Flotation and contact angle results indicated that pyrite could be depressed by KMnO4at pH 7, while KMnO4-treated chalcopyrite could be floated by sodium ethylxanthate. For the pyrite-chalcopyrite mixture, the recovery of chalcopyrite was nearly 95% and that of pyrite was less than 15% when minerals were reacted with 4 × 10−4KMnO4for 3 min. The KMnO4-treatment raised the zeta potential of pyrite at pH 7, which may generate oxidized species on the pyrite surface. The oxidation products on the pyrite surface were FeO, FeOOH, and Fe2(SO4)3as determined by XPS analyses. These oxidation products were well coated on the pyrite surface, which dramatically lowers the hydrophobicity of pyrite. In contrast, in the case of chalcopyrite, KMnO4treatment did not generate new oxidation components on its surface, causing the chalcopyrite surface to remain hydrophobic and allowing the flotation of chalcopyrite by air bubbles. Thus, pyrite could be efficiently separated from chalcopyrite using KMnO4as a depressant.

The Cu/SAPO-34 zeolite serves as an efficient active component for the selective catalytic reduction (SCR) of nitrogen oxides (NOx) in flue gas by ammonia. Despite its commendable high-temperature hydrothermal stability, the application of Cu/SAPO-34 zeolite is limited due to low-temperature hydrothermal deactivation issues in the steam environment. In this paper, we provide a systematic review on the denitration mechanism, low-temperature hydrothermal deactivation mechanism, factors influencing its low-temperature hydrothermal stability, and the corresponding improvement measures of Cu/SAPO-34 zeolite. Additionally, the advantages and disadvantages of different methods are analyzed to offer valuable insights for future research.

The drilling industry, at the crossroads of technological advancement and environmental responsibility, is perpetually in pursuit of novel and sustainable methodologies to enhance drilling fluid performance. As fossil fuel exploration and extraction remain indispensable to the global energy landscape, the imperative to minimize the ecological footprint of these operations has never been greater. This research paper represents a comprehensive investigation into a promising avenue for achieving such novelty by the incorporation of green chemicals, biopolymers, and nanoparticles into drilling mud formulations. This study seeks to unravel the potential of green alternatives in revolutionizing the performance of drilling fluids, particularly in the context of mitigating torque and drag. Torque and drag issues, arising from the interaction between the drill string and the wellbore wall, can be profoundly disruptive. They hamper drilling efficiency, elevate operational costs, and increase environmental burdens. Green chemicals, biopolymers, and nanoparticles are poised to be the vanguards of change in this domain for a more efficient and economically sustainable drilling industry. Notably, the study focuses on the novel application of taro root mucilage as a green chemical, for which limited research exists, alongside sodium alginate as the biopolymer, and graphene oxide as the nanoparticles. This unique combination underscores the innovative nature of the research, as very few studies have explored the potential of taro root mucilage in drilling applications. Rigorous laboratory experiments will follow, under carefully controlled conditions, to scrutinize the rheological properties, lubricity, and overall performance of these formulations. The crucible of these experiments will be the measurement of torque and drag under simulated drilling scenarios, enabling precise quantification of the impact of green chemicals, biopolymers, and nanoparticles on drilling efficiency. We anticipate revelations regarding the potential of green chemicals to minimize environmental impact, the versatility of biopolymers in replacing traditional synthetic polymers, and the astonishing capabilities of nanoparticles in reducing friction and drag within the wellbore. This innovative approach not only highlights the industry’s commitment to sustainability but also underscores the potential for groundbreaking advancements in drilling fluid technology, paving the way for a more efficient, economically viable, and environmentally responsible drilling industry of the future.

The burgeoning interest in porous nanoscale two-dimensional materials in recent years is driven by their remarkable properties, especially in the realm of energy, material transport, sequestration and storage. Metal and covalent organic frameworks are crystalline porous materials, drawing significant attention not only for their intrinsic properties but also for the potential of integrating them with other materials to create hybrid novel frameworks with enhanced functionalities. In this paper, we undertake a comprehensive exploration of the utilization of graph entropies and topological descriptors. This includes newly formulated hybrid indices derived from geometric, harmonic, and Zagreb descriptors applied to two variants of hexatriphenylene, integrated with metal and covalent organic frameworks. Additionally, we conduct a scaled, bond-wise comparative analysis between the metal and covalent frameworks, which provides sophisticated tools to compare the latent entropies and topologies of the two frameworks.

The specific mechanism of influence of added Si in advanced high-strength steel (AHSS) on the formation of zirconium-based hybrid coatings is discussed in detail in this paper. The results of electrochemical impedance spectroscopy (EIS) revealed that the coating resistance of the zirconium-based hybrid coating increased from 11.7 Ω·cm2to 359.9 Ω·cm2with the increase in silicon content in the high-strength steel from 0.47 wt.% to 1.70 wt.%. The scanning electron microscopy (SEM) analysis demonstrated that the defects within the coating gradually decreased as the silicon content in the high-strength steel increased. Simultaneously, with the increase in silicon content in high-strength steel, the coating resistance of the composite coating increased from 665 Ω·cm2to 1544 Ω·cm2and the degree of coating damage significantly decreased when combined with bisphenol-A epoxy resin, which indicated that an increase in silicon content in AHSS enhanced the corrosion resistance, uniformity, and adhesion of the zirconium-based hybrid coating. By combining X-ray photoelectron spectroscopy (XPS), glow-discharge optical emission spectroscopy (GDOES) and focused ion beam-transmission electron microscope (FIB-TEM) results, the enhancement of the zirconium-based hybrid coating properties was related to the enhancement of the MnSiO3and SiO2contents on the surface of the AHSS. MnSiO3was found to provide the initial nucleation sites for the zirconium-based hybrid coatings, while SiO2could accelerate the deposition reaction of the coatings, resulting in the formation of excellent zirconium-based hybrid coatings on high Si steels with higher MnSiO3and SiO2contents.

The effect of different inorganic aluminum sources on the synthesis of ZSM-5 zeolite was firstly investigated under solvent-free conditions using rice husk ash as the silicon source in this paper. XRD, SEM, TEM, 27Al MAS NMR, BET and NH3-TPD were adopted to study the effects of different aluminum sources on the crystal growth, morphology, and properties of ZSM-5 zeolite. The research results indicate that different aluminum sources have varying effects on the crystallization rate and crystallinity of ZSM-5 zeolite, and Al(NO3)3·9H2O and AlCl3·6H2O are not conducive to the synthesis of ZSM-5 zeolite. Under the same synthetic conditions, the ZSM-5 zeolites synthesized from different aluminum sources exhibit lamellar crystal accumulation, results in the ZSM-5 zeolite had a micro-mesoporous physical structure. Only tetrahedral aluminum of ZSM-5 zeolite exist in synthetic when Al2(SO4)3and Al2(SO4)3·18H2O are used as aluminum source, nevertheless, there are framework of ZSM-5 zeolite and extraframework aluminum in the products when Al(OH)3and NaAlO2are used as aluminum source, lead to different surface properties of synthesized products. The research conclusion of this article provides a basis for the selection of inorganic aluminum sources for the solventless synthesis of ZSM-5 zeolite from rice husk ash.

This paper presents an experimental investigation on the preparation and application of AC/TiO2dynamic membranes (DM) in oil-in-water (O/W) emulsions separation. Experimental results show that after three filtration cycles, pre-coating process decreased the fouling of support membrane and increased flux recovery rate (8.9%) while using the self-forming DM was aggravated fouling of the support membrane by decreasing of flux recovery rate (6.5%). By substitution of sodium dodecyl sulfate (SDS) with deionized water in the backwashing step, the cleaning efficiency was enhanced for all DMs. Cleaning efficiency when SDS was used for backwashing was increased for pre-coated DM with a flux recovery rate of 60.3%. The use of the pre-coated DM along with the use of SDS as a cleaning agent and ultraviolet light power can be considered as a promising protocol to reduce the fouling of support membrane and increase membrane cleaning efficiency with a flux recovery rate of 62.3%.

Thorium is much more abundant than uranium in nature and has become one of the important potential energy sources in the future. It is because that a thorium-232(232Th) nucleus has the ability to produce a uranium-233(233U) nucleus by absorbing a neutron. The aim of this paper is to investigate the extraction and separation of thorium ions and uranyl ions from aqueous solution with N,N’-dimethyl-N,N’-dioctyl-4-oxaheptanediamide (DMDOHA) into ionic liquids of 1-methyl-3-butylimid-azolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]). The results show that the extractant DMDOHA has a good affinity toward thorium ions than uranyl ions in the present system, the maximum value of separation factor SFTh(IV)/U(VI)is 21.9 at pH 2.24. The extraction process of thorium ions and uranyl ions was confirmed to proceed by cation-exchange extraction mechanism. The DMDOHA extractant formed a major 3:1 complex with thorium ion and a major 2:1 complex with uranyl ion based on the relationship between log[DMDOHA] with logD.

The paper presents the new data of gas transfer characteristics of semicrystalline poly(4-methyl-1-pentene) (PMP) as for films as for hollow fibers (HFs) with dense selective layer. The experimental data obtained earlier made it possible to calculate the gas transport characteristics of the amorphous and crystalline phases of PMP for some gases at temperature from 10 to 80 °C (below and above Tg). On the basis of these data and using the correlation approach, an assessment of the expected gas transport characteristics of HFs based on PMP was carried out in this work for helium and lower hydrocarbons, as well as for water vapors. It is shown that crystalline phase is very permeable and higher crystallinity degree leads to the increasing of PMP selectivity. Laboratory-scale membrane module with commercial hollow fibers of PMP was prepared and successfully tested by the differential method of gas permeability. Application of crazing method which should increase the crystallinity degree of PMP seems promising for the production of perspective HFs with improved transport and separation performance compared with the existing ones.

Products derived from wild-grown plants represent a growing segment of the modern pharmaceutical industry. In recent years, particular attention has been paid to their application in the cosmetic industry. The content of B group vitamins in these products is important because they affect the quality of the skin, hair and nails. The determination of thiamine and riboflavin in natural products is not so simple, as it requires complex sample preparation procedures and very sensitive analytical methods. In this paper, the HPLC method with fluorescence detection was applied to the determination of riboflavin and thiamine in the aqueous, ethanol and methanol extracts of elderberry, rosehip, rowanberry, wild garlic and blackthorn. Also, the influence of the extraction solvents on the vitamin’s concentration in obtained extracts was examined. It was found that the content of these vitamins in aqueous extracts is higher than that in alcoholic extracts. Riboflavin concentrations were in the range of 0.84–20.4 μg/g of the dry extract, while thiamine levels were from 0.06 to 0.67 μg/g of the dry extract. The highest riboflavin concentration was found in wild garlic extract followed by rosehip and elderberry extracts. On the other hand, thiamine content was higher in elderberry extract, while in rosehip it was not detected. In this work, the content of riboflavin and thiamine was determined for the first time in extracts of wild garlic, elderberry and rowanberry.

Abstract: Carbohydrazones are compounds that are increasingly studied due to their wide potential biological activity. Monocarbohydrazones (mCHs), as one of the carbohydrazone derivatives, so far have been poorly investigated. For a more detailed study, in this paper, eighteen compounds of monocarbohydrazones (eight known and ten newly synthesized derivatives) were synthesized and characterized using NMR and IR spectroscopy. As carbohydrazones show E/Zisomerization caused by the presence of the imino group, some of the synthesized mCHs are in the form of a mixture of these two isomers. The effects of specific and nonspecific solvent–solute interactions on the UV absorption maxima shifts were evaluated using linear free energy relationships principles, i.e., using Kamlet–Taft’s and Catalan’s models. For more information about interactions between dissolved substance and the surrounding medium, correlations have been made with Hansen’s solubility parameters. The influence of the structure on the spectral behavior of the compounds tested was interpreted using Hammett’s equation. Experimentally obtained physicochemical properties of mCHs were compared to and confirmed with computational methods that included TD-DFT calculations and MP2 geometry optimizations. Graphic abstract:

Point-of-care diagnostics (POC), including urine test strips, offer several advantages over traditional laboratory-based urine analysis. POC allows us to regulate our nutritional needs. Urine analysis is a common diagnostic and well-being monitoring tool used to evaluate the overall health of an individual. It involves the examination of a sample of urine to detect and measure various substances and markers found in urine, such as proteins, glucose, leukocytes, ketones, and bilirubin, among others. Urine test strips, also known as dipstick tests, are a quick and convenient method of urine analysis that can be performed in conjunction with smartphone and AI-based analyses. These tests use a small strip of paper with chemically-treated reagents that change color when they react with specific substances found in urine. Dietary intake can have a significant impact on the composition of urine, as certain nutrients and compounds are metabolized and excreted through the kidneys. Understanding the effects of dietary intake on urine biomarkers can provide valuable insight into the overall health and nutritional status of individuals. This review explores existing literature to highlight the intersection between strip-based urine analysis, smartphone-based analysis, gold standards, and recent developments in urine analysis.

Falsified drugs are a serious problem of modern society. Therefore, it is necessary to develop a fast and simple method of drug screening for checking of their falsification. In this article, we present paper-based test methods that can be used to identify amoxicillin, a β-lactam series antibiotic agent, used the mobile phone camera. The detection time is 10 min. Ninhydrin, p-dimethylaminobenzaldehyde, and Fehling’s reagent are used as reagents for the test. We have found out the optimal conditions of express analysis, including temperature and duration of heating. We have obtained the color scales for visual and colorimetric detection of the antibiotic agent. Optimal color parameters for RGB, CMYK, and HSV color models have been analyzed. We have demonstrated linear correlations between optimal colorimetric parameters and antibiotic agent concentration. Profiles of radar diagrams using color parameters as coordinates are obtained. Linear correlation between area and perimeter of radar diagrams and amoxicillin concentration was found.

The present paper designs and optimizes a passive micromixer with fan-shaped obstacles using computational fluid dynamics (CFD) and machine learning (ML) algorithms. Two types of micromixers with fan-shaped obstacles, named MFO-I and MFO-II, are compared with a T-shaped micromixer. The results reveal that the MFO-I has better performance compared to the two other ones; therefore, this micromixer is selected to be developed and designed. The CFD simulations of the MFO-I demonstrate that the number of mixing units (m), obstacle radius (r), obstacle angle (α), and inlet velocity (Uin), should be considered to optimize the micromixer. It is found that the mixing efficiency (ME) is improved by augmenting Uin, r, and m. For instance, ME is enhanced from 28.16 to 89.211 by changing m from 1 to 12. Besides, the values of ME are 13.832% and 47.338% for Uin= 0.005 and 1 m/s, respectively, indicating that ME is improved about 3.42 times. Seven ML algorithms are utilized to optimize the micromixer, indicating that the MPR algorithm can provide excellent prediction values for ME and pressure drop (Δp).

In this work, 2-phenylimidazo[1,2-a]pyridine-based probe was designed, synthesized, and evaluated for the selective detection of diethyl cyanophosphonate (DECP), a tabun mimic, chemical warfare agent (CWA). The addition of DECP produces a rapid fluorescence color change from blue to green, which is visualized at wavelength of 365 nm. Mechanistic investigation indicates phosphorylation of the amino unit of 4-(imidazo[1,2-a]pyridin-2-yl)aniline in the presence of DECP, inhibits photoinduced electron transfer (PET) phenomenon that subsequently produced a fluorescence color change. The probe was found to be selective towards DECP with no detectable interference with other analytes. Further, immobilization on a paper strip, the fluorogenic probe can detect organophosphorus nerve agent simulant (DECP) in solution as well as in the vapor phase, making the system a viable choice for chemical warfare agent detection in the field. The limit of detection (LOD) and limit of quantification (LOQ) for DECP was found to be 0.23 μM and 0.70 μM, respectively, with respect to the linear field concentation range of 0, 0.4, 0.8, and 1.2 μM, the standard deviation found as 17.19 whereas, RSD% = 2.89. The probe not only shows high sensitivity and selectivity in solution but can also be applied for the recognition of DECP in the vapour state with significant color changes.

Abstract: A safe, simple, and low environmental impact method for controlling the oxidation and aggregation of metallic copper (Cu) nanoparticles has yet to be developed. This paper describes the synthesis of metallic Cu nanoparticles dispersed in water fabricated by a surfactant-free method and silica coating of metallic Cu nanoparticles. A colloid solution of metallic Cu nanoparticles was prepared from Cu(CH3COO)2(Cu source), hydrazine (reducing reagent), and citric acid (stabilizer) in water in air. Silica coating of the metallic Cu nanoparticles was performed by adding sodium silicate to the metallic Cu nanoparticles in water. The silica-coated nanoparticles had a particle size of 99.2 ± 34.8 nm, a silica shell thickness of 5.8 nm, and a crystal size of metallic Cu of 28.5 nm. The metallic Cu nanoparticles in the silica-coated particles were not so oxidized even with annealing in air at 200 °C: the silica shells functioned as a physical barrier to control oxidation of the metallic Cu nanoparticles. Graphic abstract:

A rapid and simple method was optimized through experimental design and validated for the separation of chromium and manganese with magnetic sorbent of Fe3O4@Ag and 2-(2-thiazolylazo)-p-cresol ligand from the effluent of a steel factory. The adsorbed metals on the magnetic sorbent were simply separated using a magnet and collected on filter paper to measure with an X-ray fluorescence device. The infrared spectroscopy, ultraviolet–visible spectroscopy, field emission scanning electron microscopy, and wavelength-dispersive X-ray spectroscopy were used to characterize and follow the steps of the constructed sorbent synthesis. The surface response methodology was used to achieve better figures of merit and more accuracy. Optimal values for the three effective parameters of the response pH, sorbent amount, and sample solution volume were obtained to be 6.0, 4.0 mg, and 50.0 mL, respectively. Under optimum conditions, the detection limits of 0.5 µg mL−1and 1.6 µg mL−1for chromium and manganese ions were achieved, respectively. The acceptable linear range of 2.0–100.0 and 5.0–100.0 µg mL−1was obtained for chromium and manganese, respectively. To show the efficiency of the method, the heavy metals of chromium (20.0 µg mL−1) and manganese (30.0 µg mL−1) were measured with a high accuracy (n= 3), and the recovery was 98% and the relative standard deviation was 2.1% in the real samples of the effluent of a steel factory.

This paper reports the production of Ni–Zn multilayer alloy coating to improve the anticorrosive behavior of the mild steel material. The deposition technique follows the square wave current pulse technique. Initially, the effect of current densities on the anticorrosive behavior of the Ni–Zn was investigated. Later, the current densities were optimized in different combinations to get a multilayer of Ni–Zn with different degrees of layering. The Ni–Zn multilayer coatings were developed on the surface of mild steel with different numbers of layers by square pulsing current density of 1 Adm−2and 3 Adm−2. The deposited Ni–Zn alloy coating was studied for its electrochemical behavior toward corrosion. Results revealed that the anticorrosive behavior of the multilayer Ni–Zn alloy coating was found to be many folds higher than that of monolayer Ni–Zn alloy coating. The comparison study of corrosion data revealed that (Ni–Zn)1/3/300multilayer coatings are less prone to undergo corrosion among all developed monolayer and multilayer coatings. The corrosion rate of (Ni–Zn)1/3/300was found to be less and in the range of 0.37 mm year−1among all developed coatings.

Hereby, in this paper, we have reported synthesis of uniform spherical-shaped nanoparticles of zinc oxide via green method, as well as their photocatalytic activity. The nanoparticles of zinc oxide were synthesized utilizing flower extract of Rhododendron arboreumwhere it performs the function of reducing as well as capping agent. The synthesized nanoparticles were characterized by numerous spectroscopic techniques such as UV–Vis and FT-IR. Scanning electron microscope analysis of product revealed spherical zinc oxide nanoparticles. Energy-dispersive spectral analysis indicated elemental composition, i.e., oxygen and zinc. The green synthesized zinc oxide nanoparticles have been employed as nanocatalyst for photocatalytic degradation of two cationic dyes, i.e., Fuchsin basic and Malachite green dye. In addition, various physicochemical parameters such as effect of the dye concentration, catalyst dosage and pH have also been optimized indicating better performance of these nanoparticles. Zinc oxide nanoparticles showed 99.18% degradation of Malachite green dye and 99.272% degradation of Fuchsin basic dye. These nanoparticles have great potential candidate as developing catalyst for selective degradation of cationic dyes.

This paper presents a numerical simulation of the tunneling rupture behavior of bubbles in microchannels using OpenFOAM. The fluid properties were characterized by the Giesekus model, and the interface was tracked by the volume of fluid (VOF) method. The effects of relaxation time λand flow velocity uon the bubble tunneling rupture behavior were examined. The results indicated that the axial length of the bubble first increases and then remains constant as the relaxation time increases. The presence of elastic force accelerates the neck refinement in the pinch-off stage. In viscoelastic fluids, the head of the bubble is closer to the inner wall than in Newtonian fluids, influenced by the first normal stress difference. Furthermore, the tail of the bubble changes from convex to concave, and the time for the bubble to reach the rupture stage accelerates with increasing flow velocity, shortening the bubble rupture cycle. The effect of the bubble rupture period was also scrutinized at various Weissenberg numbers. The results showed that the bubble rupture period increases with the Weissenberg number, indicating that the presence of elasticity slows down the bubble rupture process.

Small Pd nanoparticles tend to aggregate during the thermal treatment or lose during the reaction process, which lead to the decrease in activity. To solve this problem, the 2D polybenzoxazine-based polymer nanosheets were selected as supports, to prepare carbon supported Pd nanoparticles by the idea of “pyrolysis embedding” in this paper. The polybenzoxazine-based carbon nanosheets supported Pd catalysts were characterized by XRD, FTIR, TEM, SEM, and XPS. The coordination interaction between nitrogen atoms and palladium ions is beneficial for stabilizing Pd nanoparticles. The Pd nanoparticles are uniformly dispersed over the carbon nanosheets, and the average size of the Pd nanoparticles is ~ 2.5 nm. The synthesized catalyst exhibited a remarkable TOF of 1928 h−1with high selectivity to benzaldehyde of > 99% for the aerobic oxidation of benzyl alcohol in aqueous media and also presented good stability.

The present research paper describes the origin, synthesis and characterization of a positional isomer and analogues of Neostigmine methylsulfate namely Benzenaminium, 2-[[(dimethylamino)carbonyl]oxy]-N,N,N-trimethyl- (o-isomer), Benzenaminium, 3-[[(diethylamino)carbonyl]oxy]-N,N,N-trimethyl-, methyl sulfate (Diethyl analog) and Benzenaminium, 3-[[(ethylmethylamino)carbonyl]oxy]-N,N,N-trimethyl-,methyliodide (Ethylmethyl analog). The key starting material (m-Anisidine) contains traces of o-Anisidine and the other raw material (Dimethylcarbamoyl chloride) contains traces of N,N-diethylcarbamoyl chloride & N-Ethyl-N-methylcarbamoyl chloride, these traces of compounds generate the impurities 2, 3& 4in Neostigmine methylsulfate. Multistep synthesis (viz: alkylation, elimination, hydrolysis and carbamoylation) and characterisation data of these three compounds is presented in detail. These three process related impurities are very essential in the generic pharmaceutical industry to develop the analytical methods for Neostigmine methylsulfate.

Effective removal of heavy metals from wastewaters can enable increased reuse of treated wastewater and reduce water scarcity worldwide. This paper describes the results of an initial study on zinc removal using waste-derived aluminosilicate-based material by binary ion exchange with calcium and potassium. About 2 mmol/g of zinc removal adsorption capacity was demonstrated using the aluminosilicate resin. Seven equilibrium isotherm models have been analyzed using the zinc adsorption data; the best fit to the experimental values based on the lowest SSE error was the SIPS model. A mechanism between zinc adsorption and the calcium and potassium desorption has been developed and modelled and is confirmed based on the mass balance analysis between the divalent calcium ions and the monovalent potassium ions exchanged with the divalent zinc ions adsorbed. Desorption studies using isotherm model equations for the calcium and potassium data further confirmed the mechanism. Regeneration was over 80% per cycle for three acid regenerations, indicating the zinc can be recovered for re-use. Furthermore, optimization using the SIPS model showed the minimum amount of adsorbent required using a two-stage reactor system is much lower, proving the need for a two-stage reactor to make the system more economical. Future experiments on multicomponent analysis and further optimization will help develop this adsorbent for real water systems.

The paper in hand deals with the adsorption characteristics of tetradecylamine on quartz surface that was investigated using Fourier transform infrared spectroscopy/energydispersive spectroscopy (SEM-EDS) analyses. The spectroscopic data were correlated with adsorption and flotation results. UV–Visible analysis was applied on a clear supernatant solution attained after solid–liquid separation at the end of adsorption, while FTIR and SEM–EDS were implemented to the dried adsorbent quartz. Moreover, in order to collate enough data on carbonate fluorapatite thermal stability with respect to chemical composition and structural parameters, the carbonate fluorapatite ore was subjected to a detailed thermogravimetry/differential scanning Calorimetry (TG-DSC) analysis. The TG-DSC analysis displays an exothermic pic at 700 °C attributed to the decomposition of carbonates, such as dolomite and calcite, and an endothermic pic at 780 °C indicating the beginning of formation of a new phase. The results indicate that the state of adsorbed tetradecylamine at quartz surface varies significantly at weak pH values. The adsorption was found to be prominent within a pH range of 8–8.5. The qualitative adsorption results were validated by quantitative analysis on quartz. The findings revealed better correlations with quartz and fluorapatite flotation tests. The overall results proved that tetradecylamine is an efficient quartz collector with resilient performance.

Improvements in drilling operations are critical for the development of the petroleum sector. Compromising in any of the drilling constraints will ultimately give rise to some serious wellbore instability issues. In this study, the effect of various cationic biopolymer water-based drilling fluids on the rheology, filtration, shale stabilization and microbial action over shale was investigated. These ions are classified as monovalent cations (K+and Na+) and divalent cations (Mg2+). According to the rheological results, it was observed that all the three fluids showed pseudo plastic characteristics. Moreover, yield point, gel strength, apparent viscosity and YP/PV ratio for K+drilling mud were far superior than any other salt sample. These parameters clearly represent effective hole-cleaning behavior for potassium ion sample. Likewise, the filtration test for these samples shows that as the size of cations decreases an increase in filtrate volume was observed. As the ionic radius decreases from 1.33 pm for K+to 0.66 for Mg2+, loss of filtrate volume increases from 6.4 to 11.2 mL. The larger size potassium ion clogged the pore sizes in the filter paper and substantial reduction in filtrate loss was observed. Furthermore, the cationic solutions when interacted with shale samples obtained from the northern region of Pakistan to investigate the shale swelling and microbial activity. Results revealed three different mechanisms of reactions between the three cations and the shale formation. Microbial activity was witnessed in K+solution after 10 days, which intensified rapidly till Day 30th, thereby completely damaged the shale sample. In Na+sample, water evaporated from the solution, leaving behind the salt crystals deposits on the face of the shale sample. When Mg2+was investigated a surprising result was perceived. The water in the salt solution found it difficult to vaporize, and it remained in the shale sample even after 30 days. On the other hand, K+ion mud was most effective as shale inhibitor. Substantial reduction in shale swelling was perceived in this mud type. These results will be significant for a drilling engineer to avoid any unnecessary problem during drilling operations in the northern Pakistan region.

The plant Nyctanthes arbor-tristisbelongs to the genus Nyctanthes (Oleaceae family) which is used in the treatment of many diseases like diabetes, cancer, inflammation, intestinal problem and tuberculosis in many countries of Asia. In this analysis, we have investigated the anti-inflammatory activity of various extracts of leaves of Nyctanthes arbor-tristisby the in vitro method as the cyclooxygenase inhibitory potential. The reported phytochemical constituent of the plant was in silico screened to find the cyclooxygenase inhibitory potential by molecular docking method. The molecular docking study of pre-isolated phytochemicals from the leaves of plants shows that compounds possess a great inhibition potential against COX-1 and COX-2 therefore, an in vitro comparative study is required to conclude the selective and potential COX-2 inhibitor for the development of new anti-inflammatory drug without causing any gastrointestinal ulcer. Here, we deliver a new strategy to design a selective COX-2 inhibitor from the plant origin natural compound by using molecular docking technique and in vitro screening of plant extract. In the other part of the paper, abortitristoside A (1) and abortitristoside B (2) were isolated from the leaves part of the plant. The isolated compound possesses good activity against COX-2 and COX-1 (IC50value 7.91–8.00 μM against COX-2) which is also established by structure–activity relationship analysis.

The excessive use of antibiotics in agriculture leads to their contamination in food and water; it is highly demanded to develop new functional materials for their fast and on-site detection. In this paper, we synthesized a zinc(II)-trimesic acid metal–organic framework (Zn-BTC) by microwave and explored its practical application for the detection of chlortetracycline (CTC) based on conformational variation mechanism. A limit of detection (LOD) of 24 nM was estimated for CTC according to the 3σ principle. Due to their similar unique structural properties, other tetracyclines also produce fluorescence enhancement upon adsorption with Zn-BTC, which can be used to distinguish tetracyclines from other antibiotics. Based on the properties, a test paper was fabricated by loading Zn-BTC on glass fiber filter paper. The paper could be used for non-contact visual detection of CTC, suggesting great application potential in water quality monitoring.

Nowadays, the production of environmentally friendly, sulfur-free fuel as a feedstock is a global requirement due to the increasing demand for ultraclean fuels. Hydrodesulfurization is the typical technique widely used in the industry that deals with severe difficulties. So, to overcome these difficulties, researchers have invented various desulfurization techniques, such as extractive, adsorptive, oxidative, or a combination of these techniques. The use of ionic liquids (ILs) in extractive desulfurization, oxidative desulfurization, and extractive–oxidative desulfurization techniques has gotten a lot of attention in the last few decades, and there have been a lot of papers written about it. In these techniques, ILs are employed as extractants and catalysts instead of traditional volatile organic solvents. This study aims to highlight the influential factors such as operating conditions, mass ratio of ionic liquid to fuel, quantity of other complementing reagents, initial sulfur content, and effects of various sulfur compounds with the key emphasis on the efficacy of ILs in both the techniques. To understand the effectiveness and multifunctional role of ILs, the influence of structure and properties of ILs, multistage extraction using ILs, regeneration and recycling of ILs are also reported in this paper. Here, a review of the interesting findings, challenges, and future perspectives to mature the performance of these techniques is discussed in detail.

Iron plays a significant role in the metabolism of cancer cells. In comparison with normal cells, neoplastic ones exhibit enhanced vulnerability to iron. Ferric ions target tumor via the ferroptotic death pathway—a process involving the iron-mediated lipid oxidation. Ferric ion occurs in complex forms in the physiological conditions. Apart from iron, ligands are the other factors to affect the biological activity of the iron complexes. In recent decades the role of iron chelates in targeting the growth of the tumor was extensively examined. The ligand may possess a standalone activity to restrict cancer’s growth. However, a wrong choice of the ligand might lead to the enhanced cancer cell’s growth in in vitro studies. The paper aims to review the role of iron complex compounds in the anticancer therapy both in the experimental and clinical applications. The anticancer properties of the iron complex rely both on the stability constant of the complex and the ligand composition. When the stability constant is high, the properties of the drug are unique. However, when the stability constant remains low, both components—ferric ions and ligands, act separately on the cells. In the paper we show how the difference in complex stability implies the action of ligand and ferric ions in the cancer cell. Iron complexation strategy is an interesting attempt to transport the anticancer Fe2+/3+ions throughout the cell membrane and release it when the pH of the microenvironment changes. Last part of the paper summarizes the results of clinical trials and in vitro studies of novel iron chelates such as: PRLX 93,936, Ferumoxytol, Talactoferrin, DPC, Triapine, VLX600, Tachypyridine, Ciclopiroxamine, Thiosemicarbazone, Deferoxamine and Deferasirox.

Here, the possibility of the existence of nitro-graphene derivatives with undisturbed graphene backbone is considered. Based on the first-principles calculation, it is shown that while NO2is unable to form a covalent bond with bare graphene, it becomes possible in some structures of hydrogenated graphane, fluorographene, and graphene oxide. This paper presents, among others, an analysis of the surrounding influence on the C-NO2bond strength. The author believes that the potential prospects of these materials and discussion about possible synthesizing routes may help further research on graphene-based materials.

In the present paper, a set of 42 derivatives for 5-oxo-1-thioxo-4,5-dihydro-1H-thiazolo[3,4-a]quinazoline are investigated in silico combining 3D-QSAR study, drug-likeness, ADMET properties, and molecular docking. The study is carried out to elaborate the reliable 3D-QSAR models using the CoMFA and CoMSIA techniques. CoMFA (Q2= 0.637, R2= 0.978, SEE = 0.058) and CoMSIA (Q2= 0.544, R2= 0.949, SEE = 0.091) models show the two elaborated models have been reliable and statistically significant. The reliability of the obtained models was validated using validation methods such as internal, external, and Y-randomization validation. Based on the contour maps of the CoMFA and CoMSIA models, we obtained information that allows us to propose five new molecules with higher MALT1 inhibitory activity than the 40 compounds. The five compounds were then examined for their drug-like and ADMET properties. Based on the results, two compounds T1 and T2 have very good ADMET properties. The two molecules selected by their ADMET properties T1 and T2 were submitted to the molecular docking test to examine the bindings established between the two newly designed molecules and the MALT1 protein. The obtained results show that the new molecules T1 and T2 have high stability in the active site of MALT1 and more efficient binding affinity compared to the reference compound 26. The two new molecules T1 and T2 may be an interesting proposition for in vitro studies in the treatment of diffuse large B cell lymphoma.

Fluorine is an essential element in the human body, which participates in the process of cell metabolism and dual effects on bone tissue and tooth enamel. Insufficient and excessive fluoride intake can lead to various diseases. Due to the special chemical properties of fluorine, there are great challenges in detection of fluoride ions. The main route of human intake of fluoride is through drinking water and food, so it is necessary to develop a convenient and efficient method for detecting fluoride ions, which is of great significance for evaluating fluoride pollution in the environment. In this paper, a reactive fluorescent probe SCC for detection of fluoride ions was designed and synthesized based on carbazole ring, which performed the characteristics of high selectivity, rapidity, and high sensitivity in the detection of fluoride ions. The detection limit was 25.9 nM, and it could be used to detect fluoride ions in aqueous systems.