Search Results (64)

This study represents comprehensive research that arises from the advanced sorption properties of zwitterionic resin beads, which were tested on simulated mono- and multicomponent heavy metal ion (HMI)-polluted water, compared to the stream collected in the Tarnita mine area. Ionic exchange resins (IExRs) were first synthesized in cationic form from a highly crosslinked (8%) acrylic copolymer, by introducing different side groups containing amino functionalities, such as ethylenediamine, triethylenetetramine, and hydrazine hydrate. The corresponding zwitterionic form of each IExR was obtained by reacting the cationic resins with sodium chloroacetate. The structures and morphologies of the synthesized resins were characterized using scanning electron microscopy and infrared spectroscopy. Successful removal of Cu(II), Fe(II), and Mn(II) was quantified by using atomic absorption spectroscopy. Tests with multicomponent synthetic solutions revealed the following typical order of retention: Cu(II) > Fe(II) > Mn(II). In the case of water samples collected from the Tarnita area, the zwitterionic resins were able to retain approximately 93.8% Mn(II), 94.7% Fe(II), and >95.5% Cu(II); in all instances, the concentration of Fe(II) was significantly higher than that of Cu(II) and Mn(II). Additionally, sorption isotherms, kinetics, and thermodynamic parameters were studied. Wheat germination was included to test the efficiency of the batch sorption using IExRs, compared to the stream collected from Tarnita, highlighting how the water cleaning process leads to healthy plant growth. The results demonstrate that, after IExRs sorption the tested HMIs content is below the permissible maximum level for surface water, effectively mitigating the pollution of the steam near to the Tarnita closed mine area, removing the main contaminants found in it. Full article

Profile control is widely employed to improve oil recovery in fractured-vuggy carbonate reservoirs. However, the limitation of current experimental evaluation methods restricts their practical guidance for field applications. In this study, urea-formaldehyde resin gel (URG) is studied using SEM, rheological analysis, FTIR, and Raman spectroscopy. Typical structural models of fractured-vuggy reservoirs are fabricated by 3D printing technology. The distribution patterns of the URG in different fractured-vuggy models are also investigated by using online NMR analysis and core slice characterization. Results show that URG exhibits a kind of 3D mesh structure with a size of 10 μm after gelation at 140 °C. The storage modulus (G′) and loss modulus (G″) of the URG gel are 387.51 Pa and 131.48 Pa, respectively. Chemical composition analysis reveals that URG is mainly composed of amide groups and sulfonate groups, showing excellent thermal stability and salt tolerance. Furthermore, after injecting URG into three types of typical models, URG displays a longitudinally decreasing distribution pattern from the injection side to the outlet side, accompanied by transverse accumulation phenomenon along the fracture walls in the slab fracture model. In the fractured-vuggy model, the gel shows continuous longitudinal distribution and uniform transverse distribution characteristics. In the beaded-vug train model, the gel’s distribution morphology gradually transforms from a “pipeline-filling” pattern at the injection side to a “conduit-dominant” pattern toward the outlet side, with a stepped distribution in the transverse direction. The breakthrough pressures during subsequent water flooding are as follows: beaded-vug train model (11.6 MPa) > fractured-vuggy model (8.1 MPa) > slab fracture model (5.9 MPa). Field application results show that the water cut is reduced from 85% to 30%, with a total incremental oil production of 2416 tons. This study conducts experimental investigations on the distribution patterns of URG in simulated fractured-vuggy models, thereby establishing a novel technical evaluation method for profile control in actual fractured-vuggy carbonate reservoirs. Full article

Proximity biotinylation, which utilizes various biotin ligating enzymes (BioID, TurboID, etc.), is widely used as a powerful tool for identifying novel protein–protein interactions. However, this method has a significant limitation: the use of streptavidin on beads for enriching biotinylated proteins often results in a high background of peptides from streptavidin itself, which interferes with identification by peptide mass fingerprinting. This limitation makes it practically impossible to study samples containing a small amount of material, such as individual insect tissues. In this study, we compared different precipitation and elution conditions for the purification of biotinylated proteins from protein extracts of Drosophila melanogaster S2 cells. We found that biotinylated proteins can be purified using anti-biotin antibodies, although with lower efficiency than streptavidin-based resin. We also demonstrated that protease-resistant streptavidin (prS), previously tested in mammalian cells, can be used effectively to purify biotinylated proteins from tissues of D. melanogaster. In our experiments, prS showed precipitation efficiency comparable to regular streptavidin but generated a lower background in peptide fingerprinting. To further demonstrate the applicability of prS for studying protein–protein interactions in D. melanogaster tissues, we carried out experiments to identify interaction partners of the ecdysone receptor (EcR) in D. melanogaster ovarian tissue using TurboID-based proximity biotinylation. As a result, EcR was found to interact with both previously described and novel protein partners in Drosophila ovaries. Full article

Recently, 3D-printed resins have been introduced as materials for definitive indirect restorations. Herein, a comparative assessment of the bond strengths of 3D-printed resins to a resin cement was performed. Methods: four definitive restorative materials were selected, i.e., a Feldspar ceramic (VITA Mark II, VM), a polymer-infiltrated ceramic network (VITA Enamic, VE), a nanohybrid resin composite (Grandio Bloc, GB), and one 3D-printed resin (Crown Permanent, CP). VM and VE were etched and silanized, GB was sandblasted, and CP was glass bead blasted; for one further experimental group, this was followed by sandblasting (CPs). A resin cement (RelyX Unicem) was then used for bonding, and then a notched shear bond strength test (nSBS) was performed. Failure modes were observed and classified as adhesive, cohesive, or mixed, and SEM representative images were taken. Data were statistically analyzed with one-way ANOVA, Tukey, and Chi-square tests. Significant differences were detected in nSBS among materials (p < 0.001). The highest nSBS was found in VM (30.3 ± 1.8 MPa) a, followed by CP^b, GB^bc, CP^bc, and VE^c. Failure modes were significantly different (p < 0.001), and with different prevalent failure modes. The bond strength for 3D-printed permanent resin materials was shown to be lower than that of the felspathic ceramic but comparable to that of the resin block and PICN substrates. Full article

In this study, a production method for ceramic shell macrocapsules and a high-temperature-resistant, polymer agent-based self-healing system was developed. Two types of macrocapsules were created by filling hollow ceramic capsules with high-temperature-resistant diallyl phthalate (DAP) resin, known for its thermal stability, and a peroxide-based curing agent. These capsules were incorporated into epoxy and DAP matrix materials to develop polymer composite materials with self-healing properties The macrocapsules were produced by coating polystyrene (PS) sacrificial foam beads with raw ceramic slurry, followed by sintering to convert the liquid phase into a solid ceramic shell. Moreover, FTIR, TGA/DTA, and DSC analyses were performed. According to the thermal analysis results, DAP resin can effectively function as a healing agent up to approximately 340 °C. In addition, quasi-static compression tests were applied to composite specimens. After the first cycle, up to 69% healing efficiency was obtained in the epoxy matrix composite and 63.5% in the DAP matrix composite. Upon reloading, the second-cycle performance measurements showed healing efficiencies of 56% for the DAP matrix composite and 58% for the epoxy matrix composite. Full article

The aim of the research was to examine the effect of sandblasting the adherent surfaces on the shear strength of aluminium alloy–glass adhesive joints. An EN AW-1050A aluminium alloy and non-hardened soda-lime glass were used as samples. The sandblasting materials in the study were copper slag and glass beads. Due to the brittleness of the glass, an adhesive joint design was created to allow strength testing. The adhesive joints took the form of lap joints, where a glass sample was placed between two aluminium samples. The length of the glass sample corresponded to the length of the adhesive joint overlap. The bonding process of the glass samples was carried out in two stages in order to maintain the dimensions of the joint. The adhesive used in the test was a two-component epoxy adhesive prepared on the basis of bisphenol A and a polyamide curing agent mixed at a ratio of 80 g of curing agent per 100 g of epoxy resin. For each sandblasting agent, adhesive joints consisting of three variations of surface treatments were made: sandblasted aluminium alloy-sandblasted glass, sandblasted aluminium alloy-untreated glass, untreated aluminium alloy-sandblasted glass. The distance between the nozzle and treated surface was 10 ± 1 cm, and the pressure of sandblasting was 0.6 MPa. One sample of each material differing in surface preparation was selected for a topography analysis. The shear strength tests performed showed that sandblasting increased the strength of the adhesive joints of the glass and aluminium alloy. The highest strength was obtained for joints where both materials were prepared using copper slag sandblasting. This was confirmed through statistical analysis. Only for this type of joint, statistical significance relative to the other adhesive bonding variants was obtained. Full article

Rapidly growing industrial biotechnology and bio-manufacturing require simple and cost-effective bioseparation tools. A novel strategy of bioseparation based on the streptavidin-decorated polyhydroxyalkanoate (PHA) nano-granules was developed in this study. By fusing to the N-terminus of PHA-associated phasin protein, the streptavidin was one-step immobilized on the surface of PHA nano-granules simultaneously with the accumulation of PHA in recombinant Escherichia coli. About 1.95 g/L of PHA nano-granules (54.51 wt% of cell dry weight) were produced after 48 h bacterial cultivation. The following qualitative and quantitative characterizations demonstrated that the streptavidin accounted for approximately 6.78% of the total weight of the purified PHA nano-granules and confirmed a considerable biotin affinity of 0.1 ng biotin/μg surface protein. As a proof of concept, the nano-granules were further functionalized with biotinylated oligo(dT) for mRNA isolation and about 1.26 μg of mRNA (occupied 2.59%) was purified from 48.45 μg of total RNA, achieving good integrity and high purity with few DNA and rRNA contaminations. Moreover, the nano-granules retained more than 80% of their initial mRNA recovery efficiency after ten cycles of repeated use. The PHA-SAP nano-granules were also functionalized with biotinylated magnetic beads, allowing magnetic recovery of the PHA nano-granules from cell lysates that still needs optimization. Our study provides a novel and expandable platform of PHA nano-granules that can be further functionalized with various biological groups for bioseparation applications. The functional PHA nano-granules have a great potential to serve as bioseparation resin for large-scale purification processes after suitable optimizations for “bench-to-factory” translation, contributing to scalable and sustainable bioprocessing. Full article

Development in hemoglobin-based oxygen carriers (HBOCs) that may be used as alternatives to donated blood requires an extensive supply of highly pure hemoglobin (Hb) preparations. Therefore, it is essential to fabricate inexpensive, stable and highly selective absorbents for Hb purification. Molecular imprinting is an attractive technology for preparing such materials for targeted molecular recognition and rapid separations. In this case study, we developed human fetal hemoglobin (HbF)-imprinted polymer beads through the fusion of surface imprinting and Pickering emulsion polymerization. HbF was firstly covalently coupled to silica nanoparticles through its surface-exposed amino groups. The particle-supported HbF molecules were subsequently employed as templates for the synthesis of molecularly imprinted polymers (MIPs) with high selectivity for Hb. After removing the silica support and HbF, the resulting MIPs underwent equilibrium and kinetic binding experiments with both adult Hb (HbA) and HbF. These surface-imprinted MIPs exhibited excellent selectivity for both HbA and HbF, facilitating the one-step isolation of recombinant Hb from crude biological samples. The saturation capacities of HbA and HbF were found to be 15.4 and 17.1 mg/g polymer, respectively. The present study opens new possibilities for designed resins for tailored protein purification, separation and analysis. Full article

Catalytic performance decline is a general issue when shaping fine powder into macroscale catalysts (e.g., beads, fiber, pellets). To address this challenge, a phenolic resin-assisted strategy was proposed to prepare porous Co/N carbon beads (ZACBs) at millimeter scale via the phase inversion method followed by confined pyrolysis. Specially, p-aminophenol–formaldehyde (AF) resin-coated zeolitic imidazolate framework (ZIF-67) nanoparticles were introduced to polyacrylonitrile (PAN) solution before pyrolysis. The thermosetting of the coated AF improved the interface compatibility between the ZIF-67 and PAN matrix, inhibiting the shrinkage of ZIF-67 particles, thus significantly improving the void structure of ZIF-67 and the dispersion of active species. The obtained ZACBs exhibited a 99.9% removal rate of tetracycline (TC) within 120 min, with a rate constant of 0.069 min⁻¹ (2.3 times of ZIF-67/PAN carbon beads). The quenching experiments and electron paramagnetic resonance (EPR) tests showed that radicals dominated the reaction. This work provides new insight into the fabrication of high-performance MOF catalysts with outstanding recycling properties, which may promote the use of MOF powder in more practical applications. Full article

In order to systematize and expand knowledge about copper-containing composite materials as hybrid ion exchangers, in this study, fine metallic copper particles were dispersed within the matrix of a carboxyl cation exchanger (CCE) with a macroporous and gel-type structure thanks to the reduction of Cu₂O particles precipitated within the matrix earlier. It was possible to introduce as much as 22.0 wt% Cu⁰ into a gel-type polymeric carrier (G/H#Cu) when an ascorbic acid solution was used to act as a reducer of Cu₂O and a reagent transforming the functional groups from Na⁺ into the H⁺ form. The extremely high shrinkage of the porous skeleton containing –COOH groups (in a wet and also dry state) and its limited affinity for water protected the copper from oxidation without the use of special conditions. When macroporous CCE was used as a host material, the composite material (M/H#Cu) contained 18.5 wt% Cu, and copper particles were identified inside the resin beads, but not on their surface where Cu²⁺ ions appeared during drying. Thermal analysis in an air atmosphere and under N₂ showed that dispersing metallic copper within the resin matrix accelerated its decomposition in both media, whereby M/H#Cu decomposed faster than G/H#Cu. It was found that G/H#Cu contained 6.0% bounded water, less than M/H#Cu (7.5%), and that the solid residue after combustion of G/H#Cu and M/H#Cu was CuO (26.28% and 22.80%), while after pyrolysis the solid residue (39.35% and 26.23%) was a mixture of carbon (50%) and metallic copper (50%). The presented composite materials thanks to the antimicrobial, catalytic, reducing, deoxygenating and hydrophobic properties of metallic copper can be used for point-of-use and column water/wastewater treatment systems. Full article

This study investigates the impact of mechanical alteration on resin composite surfaces and its subsequent effect on repair bond strength. A total of 100 resin composite disks were prepared and were allocated for 24 h or 1 year of artificial aging. Specimens were embedded in epoxy resin, and the composite surfaces were mechanically altered using either diamond burs or air abrasion with aluminum oxide or glass beads. A universal bonding material was applied and a 2 mm circular and 3 mm high repair composite cylinder were prepared using a Teflon mold. Then, the specimens were tested for their shear bond strength, and the de-bonded specimens were observed under a scanning electron microscope to determine the failure pattern. SPSS 26.0 statistical software was used to analyze the data. Two-way ANOVA showed a statistically significant effect of mechanical alteration and aging on the shear bond strength of S-PRG-filler-based resin composite (p < 0.05). Surface modification with a fine diamond bur showed a significantly higher bond strength in both 24-h- and 1-year-aged specimens. Surface modification with alumina significantly increased the bond strength of 1-year-aged specimens; however, it was statistically insignificant for 24 h-aged specimens. Mechanical alteration with a fine diamond bur and 50-micron alumina can improve the repair bond strength of the composite. Full article

Humic substances (HSs) present in water and wastewater cause fouling of anion exchange resins (AERs), which mainly results in reducing the ion exchange capacity (IEC). In this paper, an attempt was made to investigate fouling of two polystyrene and one polyacrylic AER using water from the Oder River, treated wastewater after the ultrafiltration process (UFTW) and digester reject water from sludge dewatering at the Janówek Wastewater Treatment Plant (WWTP) in Wrocław. HSs contained in digester reject water were characterised by the lowest aromaticity and molecular weights (MWs), the highest proportion of hydrophilic fraction and the highest amount of oxygenated functional groups. The Fourier-transform infrared (FTIR) analyses made it possible to identify chemical bonds characteristic of HSs and determine the mechanism of their retention on the surface of AER beads. The conducted experiments brought unexpected results, as the IEC increased with the amount of organic matter in the feed. Presumably, the humic substances accumulated on the beads and in the porosity of the anion exchangers themselves participated in the ion exchange process. Full article

Mass photometry (MP) is a fast and simple analysis method for the determination of the proportions of subpopulations in an AAV sample. It is label-free and requires minimal sample volumes between 5–10 µL, which makes it a promising candidate over orthogonal techniques such as analytical ultracentrifugation (AUC), cryo-transmission electron microscopy (Cryo-TEM) or charge-detection mass spectrometry (CDMS). However, these methods are limited in their application to purified samples only. Here we developed a purification step based on single-domain monospecific antibody fragments immobilised on either a poly(styrene-divinylbenzene) resin or on magnetic beads prior to MP analysis that allows the quantification of empty, partially filled, full and overfull AAV vectors in crude cell extracts. This is aimed at identifying potentially promising harvest conditions that yield large numbers of filled AAV vectors during the early stages of the viral vector development platform, e.g., the type of transfection reagent used. Furthermore, we provide a direct comparison of the automated and manual handling of the mass photometer with respect to the quantities of AAV subspecies, molar mass of the capsid and payload, and highlight the differences between the “buffer-free” sample measurement and the “buffer-dilution” mode. In addition, we provide information on which candidates to use for calibration and demonstrate the limitations of the mass photometer with respect to the estimation of the capsid titer. Full article

A novel solid-state neutron and gamma radiation monitor-dosimeter based on biopolymer polylactic acid (PLA) is presented. The resulting detector (PLAD) technology takes advantage of property changes of the renewable PLA resin when subject to ionizing nuclear radiation. A simple yet rapid and accurate (±10%) low-cost (<$0.01/detector) mass loss upon dissolution (MLD) technique was successfully developed; MLD is based on a simple mass balance for discerning neutron and/or gamma doses using small (40 mg, ~4 mm diameter) ultra-low-cost (<$0.01) resin beads via dissolution in acetone. The GammaCell^TM Co-60 irradiator, and the PUR-1 12 kW fission nuclear research reactor were utilized, respectively. Irradiation absorbed doses ranged from 1 to 100 kGy. Acetone bath temperature was varied from ~40 °C to ~54 °C. Results revealed a strong dependence of MLD on acetone bath temperature between neutron and gamma photon dose components; this allowed for the unique ability of PLAD to potentially perform as both a neutron-cum-gamma or as a gamma or neutron radiation dosimeter and intensity level detector. A linear trend is found for combined neutron and gamma radiation doses from 0 to 40 kGy when dissolution is conducted above 50 °C. The important potential ability to distinguish neutron from gamma radiation fields was scoped and found to be feasible by determining MLD at 45 °C. The potential was studied for simultaneous use as an in-core neutron and gamma monitor of an operating 3 GWt light-water reactor (LWR). Scoping tests were conducted with the pre-irradiated (@ 20 °C) PLAD resin beads followed by heating to in-core LWR coolant (300 °C) conditions for ~30 s corresponding to the time to reach ~40 kGy total doses in a typical 3 GWt LWR. MLD results were unaffected, indicating the exciting and unique potential for in situ (low-cost, accurate and rapid) simultaneous mapping of neutron and gamma radiation fluxes, related dosimetry, and fission power level monitoring. Full article

Several chromatographic approaches have been established over the last decades for the production of pharmaceutically relevant viruses. Due to the large size of these products compared to other biopharmaceuticals, e.g., proteins, convective flow media have proven to be superior to bead-based resins in terms of process productivity and column capacity. One representative of such convective flow materials is membranes, which can be modified to suit the particular operating principle and are also suitable for economical single-use applications. Among the different membrane variants, affinity surfaces allow for the most selective separation of the target molecule from other components in the feed solution, especially from host cell-derived DNA and proteins. A successful membrane affinity chromatography, however, requires the identification and implementation of ligands, which can be applied economically while at the same time being stable during the process and non-toxic in the case of any leaching. This review summarizes the current evaluation of membrane-based affinity purifications for viruses and virus-like particles, including traditional resin and monolith approaches and the advantages of membrane applications. An overview of potential affinity ligands is given, as well as considerations of suitable affinity platform technologies, e.g., for different virus serotypes, including a description of processes using pseudo-affinity matrices, such as sulfated cellulose membrane adsorbers. Full article