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Purification of valuable engineered proteins and enzymes can be laborious, costly, and generating large amount of chemical waste. Whilst enzyme immobilization can enhance recycling and reuse of enzymes, conventional methods for immobilizing engineered enzymes from purified samples are also inefficient with multiple-step protocols, regarding both the carrier preparation and enzyme binding. Nickel ferrite magnetic nanoparticles (NiFe2O4 MNPs) offer distinct advantages in both purification and immobilization of enzymes. In this work, we demonstrate the preparation of NiFe2O4 MNPs via a one-step solvothermal synthesis and their use in direct enzyme binding from cell lysates. These NiFe2O4 MNPs have showed an average diameter of 8.9 ± 1.7 nm from TEM analysis and a magnetization at saturation (Ms) value of 53.0 emu g–1 from SQUID measurement. The nickel binding sites of the MNP surface allow direct binding of three his-tagged enzymes, d-phenylglycine aminotransferase (d-PhgAT), Halomonas elongata ω-transaminase (HeωT), and glucose dehydrogenase from Bacillus subtilis (BsGDH). It was found that the enzymatic activities of all immobilized samples directly prepared from cell lysates were comparable to those prepared from the conventional immobilization method using purified enzymes. Remarkably, d-PhgAT supported on NiFe2O4 MNPs also showed similar activity to the purified free enzyme. By comparing on both carrier preparation and enzyme immobilization protocols, use of NiFe2O4 MNPs for direct enzyme immobilization from cell lysate can significantly reduce the number of steps, time, and use of chemicals. Therefore, NiFe2O4 MNPs can offer considerable advantages for use in both enzyme immobilization and protein purification in pharmaceutical and other chemical industries. [ABSTRACT FROM AUTHOR]

Samples with porosities of 2–3 and 13% consisting of fine-grained quartz dispersed in a silver matrix were subjected to shock compression up to 28, 33, and 37 GPa in planar recovery ampoules. In samples with a porosity of 2–3%, after purification from silver, along with amorphized quartz, a crystalline high pressure silicon dioxide phase was detected by powder X-ray diffraction, which differs from stishovite and presumably has a monoclinic lattice. [ABSTRACT FROM AUTHOR]

The effect of acoustic low-intensity oscillations in a homogeneous tube and in a tube with a conical extension is experimentally investigated for the same resonator volumes. The resonator shape is shown to have an effect on the oscillation spectrum and intensity and the pressure wave shape at constant values of the resonance frequency and the piston displacement amplitude. An increase in the resonator Q-factor is observable, when the resonator has a conical extension. An accelerated aerosol sedimentation in tubes is revealed in the case of acoustic oscillation with the resonance frequency. In the presence of a conical extension the aerosol drop concentration is reduced by a factor of 1.2 more rapidly than in the case of a uniform tube and three times more rapidly as compared with natural sedimentation. The results obtained can be used for increasing the efficiency of acoustic methods of gas purification from the disperse phase. [ABSTRACT FROM AUTHOR]

Macroporous-interconnected cryostructures are prepared via a cryo-process, where polymerization and internal crosslinking are primarily conducted at the sub-freezing temperature of the medium. Due to their unique and desirable properties, the potential of cryostructures has been examined in tissue engineering, cancer research, drug delivery, and sensors/biosensors. The macroporous cryostructures assist in trafficking cells, and the interconnected macropores provide a favorable environment for attaching cells during transplantation. These properties make such structures a great candidate for the preparation of three-dimensional (3D) systems suitable for the delivery of drugs, cell culture and tissue engineering, successive production of biomolecules, and purification of macromolecules such as proteins. Cryostructures have also been studied to improve the physical, chemical, mechanical, and release properties of controlled-release pharmaceutical dosage forms. In this review, we provide deep insights into the preparation and characterization of 3D cryostructures, discuss the factors affecting their properties, and elaborate on their contemporary biomedical and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

The use of heavy actinide targets, including 243Am, 240,242,244Pu, 245,248Cm, 249Bk, and 249Cf, irradiated by intense heavy ion beams of 48Ca has resulted in a significant expansion of the periodic table since 2000, including the discovery of five new heaviest elements and more than 50 new isotopes. These actinide materials can only be produced by intense neutron irradiation in very high flux reactors followed by chemical processing and purification in specialized hot cell facilities available in only a few locations worldwide. This paper reviews the reactor production of heavy actinides, the recovery and chemical separation of actinide materials, and the preparation of actinide targets for superheavy element experiments. The focus is on 248Cm, 249Bk, mixed 249−251Cf, and 254Es, including current availabilities and new production processes. The impacts of new facilities, including the Superheavy Element Factory at Dubna, accelerator and separator upgrades at RIKEN, and proposed upgrades to the High Flux Isotope Reactor at Oak Ridge are also described. Examples of recent superheavy element research are discussed as well as future opportunities for superheavy research using actinide targets. [ABSTRACT FROM AUTHOR]

Abstract—Layered double zinc and aluminum hydroxide modified with hexacyanoferrate(II) ions was synthesized for the first time by reverse deposition. The obtained samples were studied by X-ray phase analysis, scanning electron microscopy, and low-temperature nitrogen adsorption, and their sorption characteristics with respect to uranium U(VI) were studied. The sorption capacity for the modified material under static conditions, determined by the Langmuir equation, was = 156.70 ± 12.38 mg/g (at phase ratio V/m = 1000 mL/g, in a monocomponent solution of uranyl nitrate UO2(NO3)2 at a temperature T = 25°C and sorption time t = 24 h). Layered double zinc and aluminum hydroxide modified with hexacyanoferrate(II) ions is a promising sorbent for purification of liquid media from uranium U(VI) due to its high capacity and specific surface area, the possibility of effective use in a wide range of pH [4, 10], and low cost. [ABSTRACT FROM AUTHOR]

Technologies of membrane-based gas separation can be integrated into existing industrial processes for low-temperature helium recovery from natural gas at the stages of crude helium separation from the N2/He mixture and its purification. The effectiveness of these processes is most affected by the properties of the materials from which the membrane is made. Due to their unique properties, metal-organic framework are promising materials for use in gas separation. In the present work, both the Monte Carlo and equilibrium molecular dynamics methods were employed to examine the temperature dependence of membrane selectivity and nitrogen permeability for separation of an equimolar mixture of N2 and He by a HKUST-1-based membrane at a pressure drop of 0.1, 0.3, and 1 MPa. It was shown that the selection of optimal temperature conditions made it possible to obtain a significant increase in membrane selectivity and permeability for nitrogen compared to corresponding parameters at room temperature. [ABSTRACT FROM AUTHOR]

Nano-scale extracellular vesicles are lipid-bilayer delimited particles that are naturally secreted by all cells and have emerged as valuable biomarkers for a wide range of diseases. Efficient isolation of small extracellular vesicles while maintaining yield and purity is crucial to harvest their potential in diagnostic, prognostic, and therapeutic applications. Most conventional methods of isolation suffer from significant shortcomings, including low purity or yield, long duration, need for large sample volumes, specialized equipment, trained personnel, and high costs. To address some of these challenges, our group has reported a novel insulator-based dielectrophoretic device for rapid isolation of small extracellular vesicles from biofluids and cell culture media based on their size and dielectric properties. In this study, we report a comprehensive characterization of small extracellular vesicles isolated from cancer-patients' biofluids at a twofold enrichment using the device. The three-fold characterization that was performed using conventional flow cytometry, advanced imaging flow cytometry, and microRNA sequencing indicated high yield and purity of the isolated small extracellular vesicles. The device thus offers an efficient platform for rapid isolation while maintaining biomolecular integrity. [ABSTRACT FROM AUTHOR]

Intrinsic 40 K radioactive backgrounds from impurities of natural K in liquid scintillation cocktails have previously been demonstrated to limit their use in ultra-sensitive applications. This work explores two methodologies in parallel for the reduction of 40 K backgrounds in the cocktails, and lays the groundwork for use in ultra-sensitive applications. In one method, alternative low-K liquid scintillation matrix constituents were identified and in the other, a simple purification method for single components and finished cocktails was developed. Both methods were verified via ICP-MS analysis. Liquid scintillation counting of selected purified cocktails demonstrated background reduction, improved stability, and enhanced performance. The best performing purified cocktail was also counted on a custom-built ultra-low background liquid scintillation counter, with results below the detector background. [ABSTRACT FROM AUTHOR]

An optimized synthesis method for 6-[18F]fluoropiperonal (6-[18F]FP) via nucleophilic substitution of the nitro group in the precursor molecule (nitropiperonal, 6-NP) with [18F]fluoride in the presence of tetrabutylammonium tosylate has been proposed. Using this weakly basic phase transfer catalyst, the amount of initial 6-NP in the reaction was reduced from 4.0 to 0.2 mg with negligible amounts after subsequent treatment of the reaction mixture with a strong base (potassium methoxide). In turn, this made it possible to separate 6-[18F]FP and 6-NP with similar physicochemical properties by a simple and efficient solid-phase extraction technique on disposable cartridges. 6-[18F]FP was fabricated with 99% radiochemical purity and a radiochemical yield of 10%. The content of unreacted 6-NP did not exceed 1 µg/mL, which is comparable to the results of laborious semi-preparative HPLC purification. [ABSTRACT FROM AUTHOR]

Silicon is identified as the most prospective anodes candidate material for lithium-ion batteries (LIBs). However, its commercialization is restricted by the large volume variation and high-cost. In this study, the silicon powders from the kerf slurry wastes are used as raw materials for the preparation of silicon/carbon anodes. An effective pretreatment process that combines the sand milling and a chemical cleaning method is utilized to prepare the purified silicon powders. Then, a facile one-step hydrothermal method is used to prepare the purified silicon/carbon composites. The results demonstrate that the chemical purification can effectively remove the organic contaminants and metal impurities on the surface of raw silicon powders. It also renders hydrophilic surfaces for the silicon powders, which improves the bonding of carbon layer and results in the improvement of the electrical performance correspondingly. The as-prepared purified silicon/carbon anode shows a high specific discharge capacity of 2099 mAh g−1 in the first cycle at the current density of 0.2 A g−1. The capacity still maintains a value of 1010 mAh g−1 after 148 cycles at the current density of 0.5 A g−1. This work not only provides a reasonable and facile solution for recycling silicon wastes from the kerf slurry but also provides a strategy for the preparation of advanced anodes for high-performance lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Nickel-zinc ferrites, which have pronounced ferrimagnetic and semiconductor properties, can be used as promising magnetically controlled photocatalysts for the purification of aqueous media from organic pollutants. The value of the specific surface area largely affects the photocatalytic properties of the material; therefore, the possibility of its control and variation at the stage of synthesis is of great scientific and technical interest. In this study, nanocrystalline ferrite of the Zn0.5Ni0.5Fe2O4 composition is obtained under conditions of solution combustion using various types of organic fuel as the main factor affecting the formation of the specific surface area, and subsequent heat treatment in air at a temperature of 500°C for 2 h. The crystal structure, chemical composition, and morphology of Zn0.5Ni0.5Fe2O4 are studied by methods of X‑ray phase analysis, X-ray spectral microanalysis, and scanning electron microscopy. The values of the specific surface area of the synthesized nanopowders are calculated based on the method of liquid-phase adsorption from a Methylene Blue solution and the low-temperature adsorption-desorption of nitrogen. The results of the X‑ray phase analysis show that a single-phase nanocrystalline product with a spinel structure is formed, where the average crystallite size varies within 11–23 nm and is inversely related to the value of the specific surface area, respectively, after the reaction with succinic acid (39.1 m2/g) and with glycine (20.2 m2/g). It is established that the choice of the fuel largely affects the formation of nanocrystals and the specific surface area of the samples, and the approach used makes it possible to control its values. [ABSTRACT FROM AUTHOR]

GaSb-based thin films are expected to be applicable to biomedical and environmental devices requiring efficient operation in the near-infrared region. In this study, the effects of dilute Bi doping on the structural properties and chemical stability of GaSb thin films were examined. GaSb and GaSb1−xBix (x = 0.011, 0.013, or 0.032) thin films were grown at 320 °C on quartz substrates and PI films by multi-cathode RF magnetron sputtering. The crystallinity of the GaSb/quartz was superior to that of the GaSb/PI. Bi doping improved the crystallinity of the GaSb thin films with the exception of GaSb0.968Bi0.032/quartz, for which the crystallinity deteriorated owing to abnormal growth due to Bi cluster formation. In addition, the crystallinity of GaSb1−xBix/PI was drastically improved at x = 0.032. The increases in grain size and hole concentration caused by Bi doping indicate that Bi assists the growth of GaSb thin films. Furthermore, elution tests revealed that Bi doping suppresses the elution of highly toxic Sb under simulated physiological conditions. These findings have the possibility to hasten the development of flexible GaSb-based biomedical and environmental devices with improved safety and lower environmental burden. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) are renowned for their unique properties with numerous and growing applications in various fields and industries. Although several methods are available to prepare CDs, low conversion yield, tedious purification processes and poor color purity remain major drawbacks. To address these issues, a cooling stage for full protonation prior to direct heating has been developed. This innovative method produces high-color purity solid-state CDs with a conversion yield of up to 99.5% in less than 6 min. The CDs synthesized by this method exhibited a highly crystalline structure, as confirmed by HRTEM, Raman and XRD analyses. In addition, the emission profile of the CDs could be effectively tuned by reducing the amount of concentrated sulfuric acid, resulting in a shift of the emission from 484 to 650 nm. The high-color purity of the CDs is postulated to be due to the solvent cage effect. Overall, this study presents a simple, efficient and rapid method for the preparation of high-quality CDs with excellent color purity and crystallinity. [ABSTRACT FROM AUTHOR]

The use of affinity peptide displaying on the surface of M13 phage has emerged as a promising alternative to antibody-based detection methods owing to its diverse structure, mass production, easy purification, and genetic manipulation, as well as excellent stability. In this study, we aimed to identify highly selective and sensitive peptide-displayed M13 phage for thrombin detection using phage display technology. Phage display was conducted using two different phage libraries (linear and cyclic forms of peptides), which displayed affinity peptides capable of binding specifically to thrombin. Throughout the biopanning process, two phage clones that displayed both peptides (WGQSFWGYQHYS and CWKLLTPWC) were selected. After the characterization of their binding abilities using enzyme-linked immunosorbent assay, whole phage particles were covalently attached to a gold electrode using MUA-EDC/NHS coupling chemistry. The thrombin detection mechanism was based on signal inhibition, and the results revealed that the specific interactions between the phage-tethered gold electrode and thrombin are critical factors affecting the decrease in the peak current of the sensor. In addition, under optimal conditions, the fabricated phage-based electrochemical sensors were capable of highly sensitive and specific thrombin detection with a good binding affinity (Kd = 17 nM for 12mer 3–17 and 14 nM for C7C 3–5) and limit of detection (4 nM for 12mer 3–17 and 10 nM for C7C 3–5), resulting in good reproducibility, even in artificial human plasma samples. This study may provide an alternative and more efficient method of detecting thrombin with desirable sensitivity, selectivity, and feasibility for the diagnosis and prognosis of coagulation disorder-related diseases. [ABSTRACT FROM AUTHOR]

Cancer continues to be a leading cause of global death despite decades of research on its prevention and cure. In the mid-twentieth century, anecdotal evidence began to accumulate that certain chemicals might be cancer-causing and this was followed up with animal model studies. These suspected substances were termed carcinogens and among those investigated were N-nitrosamines (or simply nitrosamines). Interest in nitrosamines is now more than a century old and research continues to explore their biology. Since the 1950's, steady progress has been made in perfecting chemistry techniques to label interesting compounds with 14C or tritium. However, there have been relatively few reports concerning the synthesis of nitrosamines with these radioisotopes, providing substances which could be valuable in advancing key nitrosamine biology research. Most of the previous literature examples of 14C or tritium labelled nitrosamines related to very specific compounds lacking wider interest and relevance. Also, the resulting products were usually of low specific activity. This paper outlines strategies to accomplish the labelling of more broadly relevant nitrosamines with 14C or tritium at high specific activity. Particularly, a library of 14C labelled nitrosamines with diverse structures was created. Exemplary experimental details are provided for the synthesis of [14C] N-nitrosodiethanolamine as well as the repurification of [ethyl-1-14C] N-nitroso-N-ethylurea. The storage and general stability of 14C nitrosamines is also discussed. Finally, as an example of a typical strategy to prepare a nitrosamine labelled with tritium, the synthesis of [3, 4-3H] N-nitrosopyrrolidine is described in detail. [ABSTRACT FROM AUTHOR]

Phosphomevalonate kinase (PMK) catalyzes the phosphorylation of phosphomevalonate via the mevalonate pathway to form diphosphomevalonate, an essential isoprenoid precursor. Fungal PMK, also known as Erg8p, is an essential enzyme with no orthologs found in animals, making it an attractive target for antifungal drug development. As Erg8p has only 16–17% sequence homology with previously reported PMKs structures, its reaction mechanism remains unclear due to the lack of structural information. Here, we present preliminary crystallographic studies of Saccharomyces cerevisiae Erg8p (SceErg8p). We expressed SceErg8p in Escherichia coli, purified, and obtained the protein crystals using the sitting-drop vapor-diffusion method. The best crystal exhibited a diffraction pattern with a resolution of 1.42 Å and belonged to the orthorhombic space group P21212, with unit cell parameters a = 87.2 Å, b = 110.0 Å, c = 55.7 Å. The structure of SceErg8p was solved using the AlphaFold2-predicted model. Structural refinement and characterization are currently in progress. [ABSTRACT FROM AUTHOR]

In this contribution, we report a general method for the synthesis of 3D graphene/Fe3O4 NPs aerogels (GA-Fe3O4-EDA) with high porosity and Fe3O4 nanoparticles (NPs) are stably loaded on a graphene substrate, representing several-fold improvements compared to the chemical method in the literature. Graphene/Fe3O4 NPs aerogels with a continuous network are fabricated via γ-ray irradiation method induced reduction of Graphene oxide/Fe3O4 in EDA/H2O mixed solution. There is no doubt that they possess stronger magnetism with the increase of Fe3O4 content. According to the above characteristics of GA-Fe3O4-EDA, the composites can be used for aqueous-organic phase separation and adsorption of magnetic substances. This work paves the way for aqueous phase purification and magnetic material adsorption. [ABSTRACT FROM AUTHOR]

Fibroblast growth factor 21 (FGF21) has pharmaceutical potential against obesity-related metabolic disorders, including non-alcoholic fatty liver disease. Since thermal stability is a desirable factor for therapeutic proteins, we investigated the thermal behavior of human FGF21. FGF21 remained soluble after heating; thus, we examined its temperature-induced structural changes using circular dichroism (CD). FGF21 showed inter-convertible temperature-specific CD spectra. The CD spectrum at 100 °C returned to that at 20 °C when the heated FGF21 solution was cooled. Through loop swapping, the connecting loop between β10 and β12 in FGF21 was revealed to be associated with the unique thermal behavior of FGF21. According to surface plasmon resonance (SPR) experiments, in vitro cell-based assays, and model high-fat diet (HFD)-induced obesity studies, heated FGF21 maintained biological activities that were comparable to those of non-heated and commercial FGF21s. Based on sequence comparison and structural analysis, five point-mutations were introduced into FGF21. Compared with the wild type, the heated FGF21 variant displayed improved therapeutic potential in terms of body weight loss, the levels of hepatic triglycerides and lipids, and the degree of vacuolization of liver in HFD-fed mice. [ABSTRACT FROM AUTHOR]

Problems of the development of liquid organic scintillators are discussed from the point of view of the content of radioactive impurities in detectors for recording rare events. The results of investigations of various methods for purifying individual scintillator components from U, Th, and K are presented. It is shown the PPO (2,5-Diphenyloxazole) scintillation additive, where the concentration of potassium may range between 0.8 and 7.1 g/g, is the main source of contamination with potassium ( K). In linear alkylbenzene (LAB, Russia), which is viewed as a promising dissolver for creating a large-scale neutrino detector, the measured concentration of potassium is about 10 g/g. [ABSTRACT FROM AUTHOR]

Although methods for the chemical separation of samarium from a rock matrix are well established, chemical separation of samarium from non-natural isotopic impurities for the purpose of 146Sm half-life measurement requires modifications to these procedures, as well as additional checks for effective separation. This work describes the chemical purification procedures associated with the 146Sm source and the results from gamma spectroscopy. The purification procedure allowed for the quantitative determination of the number of 146Sm atoms using a modified isotope dilution technique. Alpha-decay counting of the sample will be applied in the future to determine the half-life of 146Sm. [ABSTRACT FROM AUTHOR]

This paper examines key features of the preparation of high-purity Ga from electronic and electrical engineering industry waste. The decrease in the melting point of impurity-containing Ga is assessed thermodynamically in the ideal solution approximation. It is proposed that the purity of gallium in the final crystallization purification step can be monitored via precision measurement of the temperature of the melt with a pyrometer. [ABSTRACT FROM AUTHOR]

Prof. Dr. Panne's ambition as an editor for ABC is to demonstrate that good analytical chemistry is at the core of many fundamental and applied scientific problems and innovations and will contribute to solving the grand challenges of our times. We continue to have a dynamic team of editors at ABC. [Extracted from the article]

This paper describes a detailed study aimed at developing technological principles of the preparation of 99.99995%-pure Cd, Zn, and Te by crystallization purification methods. We have analyzed the thermophysical properties of Cd, Zn, Te, and structural materials of the equipment involved; substantiated the choice of graphite as a crucible material; and determined its engineering features. We have studied impurity distributions in Cd, Zn, and Te in crystallization processes and determined effective performance parameters of the materials refining process in horizontal directional solidification and zone melting steps. The results have allowed us to obtain 99.99995 to 99.99999%-pure Cd, Zn, and Te in terms of 30 major impurities, with a maximum product yield of up to 85%. [ABSTRACT FROM AUTHOR]

Selective isolation of soil Actinobacteria was undertaken to isolate a new class of antibiotics and bioactive molecules. A Streptomyces sp. PSAA01 (= MTCC 13,157), isolated from soil of Eastern Himalaya foothill was cultivated on a large scale for the production of the antimicrobial SM02. It has been found that the maximum amount of SM02 produced while PSAA01 was grown in ISP-2 medium (pH 7.0) for 7 days at 30 °C in shaking (180 rpm) condition. A significant zone of inhibition against Staphylococcus aureus MTCC 96 has been found with the crude cell-free culture media (50 µL) of 7 days grown PSAA01. After the purification and chemical structural characterization, we found that SM02 is a new antimicrobial having 746 dalton molecular weight. The compound SM02 contains pyrimidine moiety in it and is produced by a species of Streptomyces and thus we have named this antibiotic pyrimidomycin. The antimicrobial spectrum of pyrimidomycin has been found to be restricted in Gram-positive organisms with a MIC of 12 µg/mL. SM02 was found active against Mycobacterium sp. and also multi-drug resistant Gram-positive bacteria with similar potency and found to disrupt the bacterial cell wall. Pyrimidomycin also showed significant impairment in the biofilm formation by S. aureus. Furthermore, pyrimidomycin showed synergy with the most used antibiotic like ampicillin, vancomycin and chloramphenicol. Pyrimidomycin did not have cytotoxicity towards human cell lines indicating its limited activity within bacteria. [ABSTRACT FROM AUTHOR]

This research proposes a low-cost and simple operation microfluidic chip to enhance the magnetic labeling efficiency of two ischemic stroke biomarkers: cellular fibronectin (c-Fn) and matrix metallopeptidase 9 (MMP9). This fully portable and pump-free microfluidic chip is operated based on capillary attractions without any external power source and battery. It uses an integrated cellulose sponge to absorb the samples. At the same time, a magnetic field is aligned to hold the target labeled by the magnetic nanoparticles (MNPs) in the pre-concentrated chamber. By using this approach, the specific targets are labeled from the beginning of the sampling process without preliminary sample purification. The proposed study enhanced the labeling efficiency from 1 h to 15 min. The dynamic interactions occur in the serpentine channel, while the crescent formation of MNPs in the pre-concentrated chamber, acting as a magnetic filter, improves the biomarker-MNP interaction. The labeling optimization by the proposed device influences the dynamic range by optimizing the MNP ratio to fit the linear range across the clinical cutoff value. The limits of detection (LODs) of 2.8 ng/mL and 54.6 ng/mL of c-Fn measurement were achieved for undiluted and four times dilutions of MNP, respectively. While for MMP9, the LODs were 11.5 ng/mL for undiluted functionalized MNP and 132 ng/mL for four times dilutions of functionalized MNP. The results highlight the potential use of this device for clinical sample preparation and specific magnetic target labeling. When combined with a detection system, it could also be used as an integrated component of a point-of-care platform. [ABSTRACT FROM AUTHOR]

The results of industrial tests, a developed technology for purifying and remelting babbits, produced from worn-out liners in sliding bearings in industrial equipment, are presented. In the present work, the development of a site at the enterprise for regenerating old bearings and the refusal of imported sliding bearings are addressed. The results were obtained at JSC "Ferganaazot," many experimental melts were carried out under various burdening options. The bearing shells made of secondary babbitts meet the quality standards in structure and properties of sliding bearing shells. In general, the properties of secondary babbitt meet the requirements of consumers for renewing sliding bearings. The research results will be used at other enterprises of the Republic of Uzbekistan to develop sites for processing babbits and establish new technological processes for renewing and increasing the service life of sliding bearings. [ABSTRACT FROM AUTHOR]

Proteins are one the most widely studied biomolecules with diverse functions and applications. Aiming at overcoming the current drawbacks of purification processes of proteins, the introduction of ionic liquids (ILs) has been a hot topic of research. ILs have been applied in the creation of aqueous biphasic systems (IL-based ABS), solid-phase extractions through poly(ionic liquid)s (PILs) and supported ionic-liquid phases (SILPs), and in the crystallization of proteins. In this sense, ILs have emerged as solvents, electrolytes or adjuvants, or as supported materials to tune the adsorption/affinity capacity aiming at developing an efficient, cost-effective, sustainable and green IL-based process for protein extraction. This review discusses different IL-based processes in the extraction and purification of proteins in the past years, namely IL-based aqueous biphasic systems (IL-based ABS), solid-phase extractions through PILs and SILPs, and protein crystallization. The type and structure of ILs applied and their influence in the different processes performance are also discussed. [ABSTRACT FROM AUTHOR]

The potential utilization and development of the Ba isotope tool depend on an accurate δ137/134Ba determination of the samples. During the chemical purification, whether the adsorption process on the surface of the ion-exchange resin could lead to the Ba isotopic fractionation and the degree of fractionation directly influence the accurate δ137/134Ba determination. In the present work, first-principles calculations based on the density functional theory were used to quantify the Ba isotopic equilibrium fractionation factor between the aqueous solution and the resin in the acid leaching process. By constructing and optimizing the geometric configurations of Ba-containing species, (Ba(H2O)n2+, Ba(H2O)nCl2, Ba(H2O)n(NO3)2, and the adsorbed Ba2+ on the surface of the resin, extracting the harmonic vibrational frequencies, we finally at 298 K obtained the fractionations, Δ137/134Basoln-ads = 0.07‰, Δ137/134BaBa(H2O)nCl2-ads = 0.05‰, and Δ137/134BaBa(H2O)n(NO3)2-ads = 0.02‰. Overall, there were almost no Ba isotope fractionations during leaching. Although the Ba isotope fractionation can be magnified by the Rayleigh fractionation process in purification, the difference in δ137/134Ba between the initial and final stages did not exceed 0.060‰ (or 0.045‰) when leaching the standard sample with HCl or HNO3, which is equal to or less than the accuracy of Ba isotopic analysis. At a common yield of 89.75%, Ba isotopic fractionation induced by incomplete recovery was 0.015‰ for HCl (or 0.011‰ for HNO3). Finally, if the influence of an incomplete recovery on the δ137/134Ba determination needs to be ignored, the recovery is suggested to be not less than 67% for HCl (or 46% for HNO3). [ABSTRACT FROM AUTHOR]

Cutting fluid has cooling and lubricating properties and is an important part of the field of metal machining. Owing to harmful additives, base oils with poor biodegradability, defects in processing methods, and unreasonable emissions of waste cutting fluids, cutting fluids have serious pollution problems, which pose challenges to global carbon emissions laws and regulations. However, the current research on cutting fluid and its circulating purification technique lacks systematic review papers to provide scientific technical guidance for actual production. In this study, the key scientific issues in the research achievements of eco-friendly cutting fluid and waste fluid treatment are clarified. First, the preparation and mechanism of organic additives are summarized, and the influence of the physical and chemical properties of vegetable base oils on lubricating properties is analyzed. Then, the process characteristics of cutting fluid reduction supply methods are systematically evaluated. Second, the treatment of oil mist and miscellaneous oil, the removal mechanism and approach of microorganisms, and the design principles of integrated recycling equipment are outlined. The conclusion is concluded that the synergistic effect of organic additives, biodegradable vegetable base oils and recycling purification effectively reduces the environmental pollution of cutting fluids. Finally, in view of the limitations of the cutting fluid and its circulating purification technique, the prospects of amino acid additive development, self-adapting jet parameter supply system, matching mechanism between processing conditions and cutting fluid are put forward, which provides the basis and support for the engineering application and development of cutting fluid and its circulating purification. [ABSTRACT FROM AUTHOR]

Chemical gardens are an example of a chemobrionic system that typically result in abiotic macro-, micro- and nano- material architectures, with formation driven by complex out-of-equilibrium reaction mechanisms. From a technological perspective, controlling chemobrionic processes may hold great promise for the creation of novel, compositionally diverse and ultimately, useful materials and devices. In this work, we engineer an innovative custom-built liquid exchange unit that enables us to control the formation of tubular chemical garden structures grown from the interface between calcium loaded hydrogel and phosphate solution. We show that systematic displacement of phosphate solution with water (H2O) can halt self-assembly, precisely control tube height and purify structures in situ. Furthermore, we demonstrate the fabrication of a heterogeneous chemobrionic composite material composed of aligned, high-aspect ratio calcium phosphate channels running through an otherwise dense matrix of poly(2-hydroxyethyl methacrylate) (pHEMA). Given that the principles we derive can be broadly applied to potentially control various chemobrionic systems, this work paves the way for fabricating multifunctional materials that may hold great potential in a variety of application areas, such as regenerative medicine, catalysis and microfluidics. Chemobrionic materials with applications in tissue engineering can be grown at the interface of calcium and phosphate solutions, however, controlling their dimensions and purity can be difficult. Herein, a flow device allows control of the height and in situ purification of chemical gardens, which can be encased in a photoset hydrogel for subsequent use. [ABSTRACT FROM AUTHOR]

Coronavirus and its spread all over the world have been the most challenging crisis in 2020. Hospitals are categorized among the most vulnerable centers due to their presumably highest traffic of this virus. In this study, centrifugal isolation of coronavirus is successfully deployed for purifying hospitals' air using air conditioners and ducts, suggesting an efficient setup. Numerical simulations have been used to testify the proposed setup due to the complexities of using experimental investigation such as high cost and clinical hazards of the airborne SARS-CoV-2 in the air. Results show that a 20-cm pipe with an inlet velocity of 4 m/s constitutes the best choice for the separation and purification of air from the virus. The proposed scalable method also efficiently separates larger particles, but it can separate smaller particles too. Numerical results also suggest installing the air purifying system on the floor of the hospitals' room for maximum efficiency. [ABSTRACT FROM AUTHOR]

Diabetes is a worldwide disease in perpetual expansion. Type 1 and sometimes type 2 diabetic patients require daily human insulin (HI) or analog administration. Easy access to insulins for insulin-treated diabetics, their relatives, and medical professionals can enable abuse for suicidal or homicidal purpose. However, demonstrating insulin overdose in postmortem blood is challenging. Tissue analyses are contributive, as insulins can accumulate before death or undergo only limited degradation. The present study describes an assay for HI and synthetic analogs (lispro, aspart, glulisine, detemir and degludec, glargine and its main metabolite (M1)) in liver, kidney, muscle, and injection site samples. It is based on a 5-step sample preparation (reduction of tissue sample size, homogenization, extraction, concentration, and immunopurification) associated with liquid chromatography coupled to high-resolution mass spectrometry (LC–MS/HRMS). Selectivity and limit of detection (LOD) for all target analogs were assessed in the above matrices. LOD was determined at 25 ng/g for HI and for analogs except detemir and degludec, where LOD was 50 ng/g in kidney and injection site samples and 80 ng/g in the liver and muscle. The method was applied to13 forensic cases in which insulin use was suspected. [ABSTRACT FROM AUTHOR]

The methods used in the nuclear industry for reprocessing liquid radwaste, including salt concentrates from evaporator plants at nuclear power plants, are discussed. The results of a technical-and-economic feasibility study of the three methods used for the processing of salt concentrates are presented: cementing, deep evaporation, and ion-selective purification. It is shown that the ion-selective purification method is the most effective one in comparison with the first two, as it effects significant volume reduction of mid-level class-3 radioactive waste transferred for disposal. Recommendations are made for changing the technology used for management of liquid waste at next-generation nuclear power plants, including separate collection and creation of local schemes for their processing and conditioning. [ABSTRACT FROM AUTHOR]

This work presents the combination of two chemical separation methods to purify protactinium (Pa) oxide from its decay daughter chain. It combines precipitation and basic to neutral washing with ion exchange to reach radiochemical pure 231Pa. The method is suitable to purify 231Pa in milligram scales. Precipitation and washing of Pa hydroxide removes most of the daughter activity and the dose rate. Losses of Pa occurs predominantly in the precipitation stage and are dependent on the conditions used. The subsequent ion exchange procedure showed essentially no losses of Pa and is efficient to fully remove all decay products leaving less than 0.4% of the Th as an impurity in the purified Pa solution. Full radiochemical purity was obtained by repeating the separation procedure. The radiochemical pure Pa solution was characterised by an alpha ratio method by addition and mixing of a known Cm spike. The specific activity and concentration of 231Pa was determined with an uncertainty of 1% (coverage factor k = 1). [ABSTRACT FROM AUTHOR]

Japanese encephalitis is a vector borne disease and the best procedure for control of this disease is control of vector population. Now a day use of phyto-chemicals more preferred over use of chemical insecticides. Isolation, purification and determination of chemical structures of bioactive compounds were done successfully from n-hexane extract of leaf of M. ferrea. The compounds shows better potentiality to control Cx. vishnui 3rd instars larvae. n-hexane extract of leaf of M. ferrea was prepared by Sohxlet apparatus and further used for bioassay against 3rd instars larvae of Cx. vishnui. n-hexane extract was further fractioned by Thin layer chromatography to isolate bioactive compounds. From different band of TLC, bioactive compounds bearing band was isolated by bioassay test. Structures of active principles were determined by FTIR, gas chromatography, mass spectrometry and with the help of library data list. Cent percent mortality of Cx. vishnui larvae was recorded at 45 ppm concentration of n-hexane extract of M. ferrea after 72 h of exposure. In isolated bioactive compounds 3-(2-Hydroxyphenoxy)-1, 2-propanediol is one of predominant compound, may be responsible for mortality of Cx. vishnui larvae. LC50 value for Cx. vishnui 3rd instars larvae of active compound are 26.76, 25.64 and 20.32 ppm for 24 h, 48 h and 72 h respectively. No mortality were recorded when sub lethal concentration (LC50) of 24 h of bioactive compound applied on non-target organisms i.e. Chironomus circumdatus, Daphnia, Diplonychus etc. The compound i.e. 3-(2-Hydroxyphenoxy)-1, 2-propanediol is predominant compound of active principles and its chemical structure is determine which is major component of n-hexane extract of leaf of M. ferrea. These bioactive principles are safe for other organisms (non-target) those share the same natural habitat. [ABSTRACT FROM AUTHOR]

The catalytic activity of hexagonal boron nitride (hBN) is not yet well understood, but it seems to be related to hBN hydroxylated sites. A good understanding of those sites and how they are produced is a key step to reveal the true nature of hBN catalytic activity. Here, we report a set of thermal treatments to produce a diversity of hydroxylated sites, as well as a method to remove the boric acid produced by hBN decomposition. We found that some of the boric acid dehydrates on the surface of hBN to produce a borated hBN (hBNO) characterized by an FTIR peat at 1090 cm−1 and an XRD shift due to the variation in the planar distance. We also showed that when characterizing the thermal treated hBN, the storage of the sample changed the borate's hydration degree and modified both the XRD pattern and the FTIR spectrum. When stored in a humid environment, boric acid peaks are visible, but they are not present if samples are stored in a dry place. The methods established here are a solid basis for the manufacture, purification and characterization of hBN by thermal treatments, showing how the process can be designed to generate various functional groups on its surface. [ABSTRACT FROM AUTHOR]

Magnetorheological fluids have a viscosity which can be controlled by the application of magnetic field. Usually they have dispersions of magnetic particles with size micrometric in a carrier liquid. After purification process, extracted material from mining waste allowed us to obtain the magnetite that was used as the magnetic component of a magnetorheological fluid. The carrier continuous medium for such fluid was 2.5 and 20 W oils. These oils are used for damping systems in high-performance motorcycles and are readily available. The magnetics particle's size ranged from 2 to 100 µm. Magnetic fields from 50 to 1200 gauss, as well as structural, morphological, and rheological studies were performed to the analyzed fluids. We observed that the model that best fits the stress vs. shear rate curves was the Herschel–Bulkley model. [ABSTRACT FROM AUTHOR]

Asrij/OCIAD1 is a scaffold transmembrane protein belonging to the Ovarian Carcinoma Immunoreactive Antigen Domain containing protein family. In Drosophila and mouse models, Asrij localizes at the endosomal and mitochondrial membrane and is shown to regulate the stemness of hematopoietic stem cells. Interaction of Asrij with ADP Ribosylation Factor 1 (Arf1) is shown to be crucial for hematopoietic niche function and prohemocyte maintenance. Here, we report the heterologous expression, standardization of detergents and purification methodologies for crystallization of Asrij/OCIAD1. To probe the activity of bacterially expressed Asrij, we developed a protein complementation assay and conclusively show that Asrij and Arf1 physically interact. Further, we find that sophorolipids improve the solubility and monodispersibility of Asrij. Hence, we propose that sophorolipids could be novel additives for stabilization of membrane proteins. To our knowledge, this is the first study detailing methodology for the production and crystallization of a heterologously expressed scaffold membrane protein and will be widely applicable to understand membrane protein structure and function. [ABSTRACT FROM AUTHOR]

The meteorological data, measurements of aerosol optical depth (AOD) and PM2.5 concentration from 2016 to 2017 in Fuling District of Chongqing were selected to study their correlation. The back propagation (BP) artificial neural network (ANN) was used to build a PM2.5 prediction model with the meteorological factors as input, and the predicted PM2.5 values were compared with the measured ones. The results show that PM2.5 concentration has a piecewise linear relationship with temperature attributed to diffusion rate and premise conversion rate, a positive correlation with relative humidity, and a significant inverse correlation with wind speed, but no apparent linear relationship with rainfall, although rainfall has a significant purification effect on PM2.5. The similarity in the influence mechanism of AOD and PM2.5 concentration leads to a certain positive correlation between them. The predicted PM2.5 by the BP ANN model shows a similar trend with the measured one, but has some significant differences in numerical values. Therefore, it is feasible to establish BP artificial neural network to predict PM2.5 by using meteorological data. [ABSTRACT FROM AUTHOR]

The liquid–liquid extraction, recovery of Np(VI) and Np(V) from the solution of Na2CO3 by methyltrioctylammonium carbonate in toluene was investigated. By the graphic slope analyses method, as well as by recording of absorption spectra for obtained solutions and method of calculated determination of solution properties taking into account water activity, composition was established for the carbonate complexes of Np(VI) and Np(V) being extracted, which, depending on extraction conditions, can be expressed by the following formulae's: (R4N)2[NpVIO2(CO3)2], (R4N)3[NpVO2(CO3)2], (R4N)6[NpVIO2(CO3)4], (R4N)2[NpVIO2(CO3)2]·2(R4N)2CO3, (R4N)5[NpVO2(CO3)3], (R4N)7[NpVO2(CO3)4], (R4N)3[NpVO2(CO3)2]·(1–2)(R4N)2CO3, where R4N is the quaternary ammonium cation. The results have been obtained in the experiments, has much interest both in the field of alkaline radioactive waste management and with respect to their usage for extraction of transuranium elements during reprocessing of alkaline radioactive waste, as well as for liquid–liquid extraction purification of uranium and plutonium from admixtures of fission products. These techniques are used within the framework of a new alternative method for reprocessing of spent nuclear fuel in carbonate media the CARBEX (CARBonate EXtraction) process. [ABSTRACT FROM AUTHOR]

A radiochemical method was developed for the accurate 55Fe determination in various radioactive waste, in particular samples contaminated with 241Pu. It consisted of three purification steps based on first ammonium hydroxide precipitation, and then anion exchange separation followed by TRU®-based extraction chromatography. It was characterized by an iron recovery yield of about 80% for all the studied samples and a 60Co decontamination factor of 106. In comparison to a standard protocol based on iron cupferrate extraction in chloroform, an improvement of a 30-fold factor was achieved towards plutonium. The developed TRU®-based procedure was validated by participating in interlaboratory exercises. [ABSTRACT FROM AUTHOR]

The stable isotope-labeled rosuvastatin was requested in order to fully understand the metabolic process of rosuvastatin. An effective synthesis approach was developed for [2H4] rosuvastatin calcium. After ten steps, [2H4] rosuvastatin calcium was prepared with excellent chemical purification and isotope enrichment which can be applied as an internal standard. Moreover, this synthesis method could be useful in synthesis of other statins. [ABSTRACT FROM AUTHOR]

Purification of nanoparticles is an important step during preparation of nanoparticles in order to remove impurities and excess ligands. Such excess ligands in the solution may have unfavorable effects on downstream processing such as ligand exchange and shell growth. Most purification methods are batchwise and time-consuming. In this work, we developed an extraction system with a membrane separation to continuously purify nanoparticles. Here, silver nanoparticles (AgNPs) in an aqueous solution were used as a case study. AgNPs were synthesized with sodium dodecyl sulfate (SDS) as capping ligands, and ethyl acetate was used as an extraction solvent to remove the ligands. This novel method showed more 56.73% removal of the ligands while maintaining the morphology of the AgNPs. In addition, the AgNPs from this method was compared with those from conventional methods such as precipitation-redissolution in terms of purity well as catalytic activity. The integration of flow synthesis of AgNPs and continuous-flow purification was also demonstrated. [ABSTRACT FROM AUTHOR]

The green microalga Haematococcus pluvialis has been widely studied due to its capacity to accumulate great amounts of astaxanthin, a high-value carotenoid with biological activities. In the present work, two green compressed fluid–based processes, pressurized liquid extraction (PLE) and supercritical antisolvent fractionation (SAF), are integrated to obtain an astaxanthin-enriched extract from this microalga. PLE was carried out using pressurized ethanol as solvent, for 20 min, at 10 MPa, and 50 °C as extraction temperature. Subsequently, the obtained extract was processed by SAF to further purify the carotenoid fraction. The SAF process was optimized using a 3-level factorial experimental design and considering three experimental variables: (i) CO2 pressure (10–30 MPa), (ii) percentage of water in the PLE extract (20–50%), and (iii) PLE extract/supercritical-CO2 flow rate ratio (0.0125–0.05). Total carotenoid content was evaluated in both extracts and raffinates. Best results were obtained at 30 MPa, 0.05 feed/SC-CO2 mass flow rate, and 20% (v/v) of water in the feed solution, achieving values of 120.3 mg g−1 carotenoids in extract (in the SAF extract fraction), which were significantly higher than those obtained in the original PLE extract. In parallel, a new fast two-dimensional comprehensive liquid chromatography (LC×LC) method was optimized to get the full carotenoid profile of these extracts in less than 25 min. This is the first time that the use of a C30 column is reported in an on-line LC×LC system. [ABSTRACT FROM AUTHOR]

Impurities are of crucial interest in optoelectronic devices as they affect carrier lifetimes and electrical properties. In view of that, it is important to incorporate certain processing steps to reduce impurities effect on final devices. The aim of this work is to enhance silicon carbide SiC purity for silicon passivation. Low cost method of SiC purification is presented. This method combines three main steps consisting of formation of porous silicon carbide layers by acid vapor etching followed by a photo-thermal annealing at different temperatures. Finally, obtained SiC powder was subject to a chemical treatment to remove porous SiC layer. Effect of gettering temperature on purification efficiency was evaluated by inductively coupled plasma atomic emission spectrometry (ICP-AES). The gettering experiment was performed at 800–950 °C, and optimum results were obtained at 950 °C. SiC purity is improved from 3 N (99.977%) to 5 N (99.999%) with an impurity removal efficiency of 96.56%. Purified SiC was used as a target to synthesize SiC layers using pulsed laser deposition technique (PLD) for optoelectronic devices. The use of intrinsic amorphous silicon carbide (a-SiC) passivating layers was investigated especially by photoconductivity decay technique. Improved SiC target purity leads to a significant enhancement of a-SiC passivating properties attributed to the surface recombination velocity decrease. Electrical properties of a-SiC/c-Si(p) were also studied using I-V and C-V techniques. [ABSTRACT FROM AUTHOR]

This work presents the synthesis of a new nano-structured samarium ion-imprinted polymer (Sm(III)-IIP) by precipitation polymerization. The Sm(III)-IIP nanoparticles were prepared by the copolymerization of Sm(III)–acrylic acid–4-vinylpyridine ternary complex with ethylene glycol dimethacrylate and methyl methacrylate, and then, Sm(III) was leached to obtain Sm(III)-IIP leached particles. Moreover, non-imprinted polymer particles were similarly prepared without Sm(III) ions. The characterization of polymers was carried out by Fourier transform IR spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis–differential scanning calorimetry (TGA–DSC) and surface analysis. The effect of several parameters such as solution's pH, sorption and desorption time, type, concentration and volume of eluent on the extraction of the polymers was investigated and optimized by one variable at the time. Optimized parameters were as follows: pH 4; mass sorbent 0.1 g; sorption time, 120 min; desorption time, 120 min; aqueous phase volume, 10 mL. Moreover, it is found that 30 mL of HCl (3 M) provided the most effective elution of Sm3+ ion from IIP beads. The maximum sorbent capacity of the IIPs is 14.91 mg g−1. The sorbent was used for purification of samarium-152 stable isotope. The samarium-152 stable isotope recovery yield was % 99.67. The detection limit of the method was evaluated to be 0.27 ng mL−1. The precision of the method (%RSD, n = 6) was % 0.47. [ABSTRACT FROM AUTHOR]

Due to widespread droughts and population increase, the rapid and sustainable purification of contaminated water is of major interest to human beings. Toward this end, this paper reports a handheld and efficient purification system using maskless micro/nanofabrication techniques. A porous polymer membrane decorated with nanomaterials was tailored to physically filter pollutants in contaminated water. To create the porous polymer membrane, curable polymer and black sugar powder were used for a facile and cost-effective fabrication method. The black sugar particles linked in cured polymer were selectively dissolved in hot water, forming micro-sized pores for filtering out pollutants. The nanowires were hydrothermally grown onto the porous membrane to further improve the purification performance by capturing finer pollutants between nanowires. The combination of nanowires and 50-wt% concentration of black sugar particle, forming a porosity of ~ 27.71% showed the minimum residual rate (i.e., weight of pollutants in purified water) of 0.981 mg/ml. This study supports the use of hierarchical porous membrane for the efficient and sustainable purification of contaminated water within a short period time. [ABSTRACT FROM AUTHOR]

A CO oxidation catalyst that includes Pt clusters applied on nanosized TiN supports with a particle size of 18 and 36 nm has been synthesized. The catalyst has been studied using TEM, X-ray powder diffraction, and XPS methods. It has been found that platinum clusters formed on the support surface are covered with a mixture of platinum and platinum oxide. The coherent scattering range of the Pt cluster is close to 8 nm on a support with titanium nitride particles of 18 nm. The catalytic properties in the reaction of CO oxidation at 295 K and low CO concentrations (<100 mg/m3) have been examined. It has been found that when the platinum content in the catalyst is 9 to 15 wt %, the CO oxidation rate is 120 times higher than that on platinum black with a specific surface area of 30 m2/g. The catalysts are promising for use in catalytic systems for air purification. [ABSTRACT FROM AUTHOR]

Supercritical fluid extraction (SFE) using cosolvent-modified supercritical carbon dioxide and a two-step separation/purification method was investigated as a way to improve the purity of glabridin, one of the many bioactive components of Glycyrrhiza glabra (licorice). The SFE parameters were optimized using an analytical-scale SFE system in the temperature range 40–80°C and the pressure range 10–50 MPa. The extraction was then scaled up by 100 times using a preparative SFE system under the following set of optimized conditions: 40°C, 30 MPa, and SCCO2 modified with ethanol equivalent to its 25% (v/v) concentration. The glabridin purity obtained through the scaled-up SFE system was 6.2%, a much higher level than that obtained through organic solvent extraction. The licorice extract obtained by scaling up the SFE system was isolated and purified by applying alcohol precipitation/ filtration and adsorption chromatography with 80% aqueous ethanol to obtain a purer product. It was confirmed that the glabridin purity of the final extract product was increased by up to 37%, without significant loss of glabridin after two separation/purification steps. [ABSTRACT FROM AUTHOR]