Separation Media Research Articles

A method for measuring the critical pore diameter of a homogeneous microchannel separator based on image analysis and a simulation comparison of CFD-DEM

Fine particles being captured or escaping from particle beds (microchannel separator) is a widespread phenomenon, with the size and distribution of pores (microchannel) significantly affecting these phenomena. However, due to the complexity of the pore structure, accurately measuring and validating it poses challenges. This paper introduces a new method to calculate the critical pore diameter of homogeneous microchannel separators (three types of homogeneous separation media with particle sizes of 0.8 mm, 1.0 mm and 1.2 mm). Initially, particle bed units with a thickness twice the diameter of the separation media were captured from multiple orthogonal projection directions to obtain high-resolution images of the pore structure. Then, the Feret diameter distribution of the pores were analyzed to quantify pore size and distribution. Next, unresolved CFD-DEM method was used to simulate the capture of fine particles to optimize and supplement the results. The results show that the average Feret diameter of the pores differs by only 0.85 μm, 1.70 μm, and 2.46 μm from the simulation results, and it is noted that the critical pore diameter is approximately 0.153 times that of the separation media diameter, the numerical difference from the critical dimension ratio is only 0.0017. Additionally, when the diameter of the fine particles is 0.155 to 0.165 times the diameter of the separation media, the homogeneous microchannel separator exhibits the highest efficiency during the deep bed filtration process. The study also examines the separation of homogeneous fine particles at varying inlet liquid flow rates, which can offer theoretical guidance for analyzing the porosity of microchannel separators and the efficient removal of solid pollutants, thus contributing novel ideas to deep bed filtration research.

Capillary electrophoresis separations with Betaine:Urea, a deep eutectic solvent as the separation medium

BackgroundCapillary electrophoresis (CE) is a highly versatile separation technique widely used in analytical chemistry. Traditionally, CE can be categorized as either aqueous or non-aqueous systems based on the buffer solvents employed. For decades, non-aqueous CE has been predominantly associated with the use of organic solvents, a perception deeply ingrained in the scientific community. However, growing concerns about the health and environmental impacts of these solvents, driven by the principles of green chemistry, have prompted a reevaluation of their use. In response to these concerns, our group recently introduced a deep eutectic solvent (DES), specifically Proline:Urea, as an innovative and eco-friendly separation medium for CE. This approach not only enhances the sustainability of CE separations but also offers a new perspective for the development of innovative CE separation media. ResultsBuilding on our previous work, here we report the use of the second DES, Betaine:Urea (BU), as a new separation medium that offers further improved performance for CE applications. The DES was systematically characterized, with key physical properties relevant to CE separations, such as thermal properties, viscosity, dielectric constant, Joule heating effect, and UV transmittance, being thoroughly examined. Using a complex sample of 10 structurally similar naphthalene derivatives, we demonstrated the efficiency of BU in capillary zone electrophoresis (CZE) for separating analytes with varying charges (including cations, neutrals, and anions) and sizes. Additionally, we established the first micellar electrokinetic chromatography (MEKC) system in this DES using sodium dodecyl sulfate (SDS) as the surfactant. This system successfully resolved 6 structurally similar neutrals that could not be separated by conventional aqueous SDS-MEKC, highlighting the versatility of this DES-type separation medium. Furthermore, BU showed several advantages over the previously reported DES, Proline:Urea, particularly in terms of stability, viscosity, and Joule heating effects. SignificanceThis study holds the potential to challenge the traditional notion that “CE separation media are merely categorized into aqueous and organic solvents”. Given that DESs are “designer” solvents with highly tunable properties and environmentally friendly characteristics, the introduction of BU as a viable alternative to traditional solvents not only expands the media available for CE separations, but also offers a more efficient and potentially more sustainable option for specific analyses.

The Challenges of the Presumption of Innocence in Lithuanian Criminal Proceedings

Abstract Although one of the key principles of the criminal procedure law - the presumption of innocence is officially declared as an aspiration in Lithuanian legal regulation and case law, there are still some areas of possible threat to this key principle. Therefore, the purpose of this research paper is to identify and analyse specific problems of ensuring the presumption of innocence in Lithuanian criminal law and criminal procedure law. So, the analysis was based on three main questions: the difficulties of ensuring the presumption of innocence in the Lithuanian criminal procedural law and Lithuanian criminal law and in the context of media. The research was carried out by employing the logical, the systematic, the linguistic, the historical, the comparative and the synthesizing research methods as well as the analysis of legal documents. The results of research analysis revealed specific areas that pose the greatest threat to violation of the presumption of innocence, as grounds for the termination of a criminal case; the general basis for issuing a preventive measure (arrest); complicity where the accomplices are tried in separate cases and media statements that have a direct impact on the impartiality of judges.

Peripheral blood mononuclear cells isolation from mouse and rabbit blood to quantify active nucleotide and define brincidofovir dose for smallpox.

Aim: Brincidofovir has been approved by the US FDA for the treatment of smallpox via the "Animal Rule". The active moiety, cidofovir diphosphate (CDV-PP), was measurable in human peripheral blood mononuclear cells (PBMCs), but quantitation in animals was challenging given their limited blood volume. The aim of this study was to optimize PBMC isolation from rabbit and mouse blood to allow quantitation of CDV-PP.Materials & methods: PBMC isolation methods using various separation media were evaluated using blood from naive and brincidofovir-dosed animals. CDV-PP was quantified using liquid chromatography tandem mass spectrometry.Results & conclusion: PBMC isolation yields were increased by >fourfold compared with yields obtained using human methods, allowing cross-species exposure comparisons.

Telemedicine through social media to enhance guideline-directed revascularization in STEMI: a five-year analysis in a developing nation

Abstract Background Timely reperfusion reduces mortality in ST segment Elevation Myocardial infarction (STEMI). Telemedicine and social media have been variably used to improve STEMI care in community settings. We established a new care system for STEMI in a public health setting serving a population of over 80 million, in a state with from a developing nation. Purpose To enhance guideline directed revascularisation (GDR) in STEMI by networking non-percutaneous coronary intervention (PCI) capable hospitals to PCI capable hospitals in a hub-and-spoke model and implementing telemedicine via social media platforms (Whatsapp) over five years(2019-2023). Methods Eighteen Government medical college hospitals were identified as hubs and were provided with cardiac catheterisation laboratories and empowered to provide either round the clock (Phase I hubs) or office hour primary PCI (Phase II hubs). They were linked to 188 Taluk or District-level, non-PCI capable Government hospitals identified as spokes to form 18 STEMI clusters. Separate social media groups on WhatsApp were created for each of the clusters, facilitating the sharing of de-identified ECGs and clinical data from spokes for guidance on diagnosis and management by hub hospital cardiologists. Transfer to hub hospitals for catheter based therapies were coordinated through prior intimation in the cluster WhatsApp group to ensure timely arrival and treatment. A customised uniform protocol for STEMI management was developed and health care personnel were trained accordingly. Human resource support was provided to collect and submit cumulative daily data on the number of STEMIs, the revascularisation provided and mortality through online free web forms. Annual cumulative data on STEMI volumes and GDR were analysed. Results 71,907 STEMI patients were treated from 2019 to 2023. We observed a 67% increase in STEMIs treated per year from over five years (11,363 in 2019 to 18565 in 2023). Use of pharmaco-invasive therapy increased from 7.9% to 31.7% (Figure-1). There was a marginal increase in use of primary PCI. The count of patients without GDR decreased by 20%. There was a 6.7 fold (672 in 2019 to 4,535 in 2023) rise in patients referred from spoke to hub hospitals for catheter-based revascularization. Over five years, there was an increase in the proportion of patients receiving GDR. This increase was more evident in Phase II hubs (52% in 2019 to 87.1% in 2023). Commensurate with the increase in GDR, phase II hubs demonstrated a tangible decrease in mortality (Figure-2). Conclusion We have shown that networking of non-PCI-capable hospitals with PCI-capable hospitals in a hub and spoke model using social media groups, facilitates telemedicine, leading to improved GDR in STEMI. This innovative approach not only enhances connectivity but also contributes to more efficient and timely cardiac care in resource-constrained settings.Figure 1. Revascularisation in STEMIFigure 2.Mortality Trends in STEMI (hubs)

Examining the Influence of Silver(I) Ion Coordination Environment in Ionic Liquids on Olefin-Paraffin Separations using Inverse Gas Chromatography.

Silver(I) ions (Ag+) undergo selective π-complexation with olefins and have been employed as separation media for the isolation of olefins from structurally similar paraffins. Ionic liquids (ILs) possess minimal vapor pressures, exceptional thermal stabilities, low melting points, as well as provide a favorable environment for π-complexation between Ag+ ions and olefins. The development of molecular drivers capable of highly selective olefin/paraffin separation systems with Ag+-containing ILs necessitates a comprehensive understanding of all factors that affect olefin solubility and selectivity. This study examines how coordinating different ligand species to Ag+ ions produces separation media with varying interaction strengths to olefins. Four coordination compounds, (4,4'-dimethyl-2,2'-bipyridine)silver(I) bis[(trifluoromethyl)sulfonyl]imide ([Ag+(DMBP)][NTf2-]), bis(pyridine)silver(I) [NTf2-] ([Ag+(Py)2][NTf2-]), bis(2,6-lutidine)silver(I) [NTf2-] ([Ag+(Lut)2][NTf2-]), and (triphenylphosphine)silver(I) [NTf2-] ([Ag+(PPh3)][NTf2-]) were dissolved in the 1-decyl-3-methylimidazolium [NTf2-] ([DMIM+][NTf2-]) IL and employed as stationary phases for inverse gas chromatography. Ligand coordination to the Ag+ ion was observed to modulate interactions of unsaturated hydrocarbons. The [Ag+(Py)2][NTf2-] complex offered the greatest olefin retention among the coordination complexes reaching 54% of the 1-octene retention factor of the uncoordinated [Ag+][NTf2-]. Hydrogen (H2) exposure studies showed ligand-dependent rates of reduction from Ag+ ion to elemental silver (Ag0). The [Ag+(PPh3)][NTf2-] complex exhibited superior stability, compared to the neat [Ag+][NTf2-] salt, reducing the retention factor of 1-octene by 15.3% and 19.4%, respectively, after 200 h of H2 exposure at 70 °C. The results from this study show that coordination complexes with Ag+ ions are useful in highly selective and efficient petroleum processing systems.

Experimental Analysis of the Supercritical CO2-Based Circulation Type for the Remediation of Kilogram-Scale Soil Samples from Metal Ions

Supercritical carbon dioxide (sCO2) has been proposed as one new alternative separation medium for soil remediation due to its preferrable dissolution properties and environmentally friendly nature. This study is focused on the effects of operation parameters, such as separation pressure, temperature and processing time, on the extraction efficiency of inorganic contaminants (chromium; arsenic) from soil samples by using the newly established kilogram-scale prototype. The prototype system was operated with Cyanex 302 as a chelating agent and methanol as a co-solvent. The extraction efficiency (EE) of chromium (Cr) is experimentally identified to be 97.98% at 35 MPa and 75 °C (with 60 min processing time), while it is found to drop quickly at low temperature and pressure (only 40% under 20 MPa and 35 °C). The EE of arsenic (As) has been identified generally with high efficiency, over 95% for most cases. For chromium (Cr), 30 MPa and 55 °C or higher parameter ranges are recommended to maintain an efficiency over 90%.

A facile synthesis of a novel polymer-based nanocomposite as colorimetric response sensor for fluoride ion detection in real-life complex mediums

The surface modification of Poly (acrylamide-co-methylenbisacrylamide-co-N-(4-(2-(phenylcarbamothioyl)hydrazineyl)phenyl)methacrylamide) as a sensor (AR) via titanium dioxide as a novel colorimetric nanocomposite sensor with high sensitivity and selectivity for determination of fluoride anion was described. The colorimetric response of the AR has been screened in dimethyl sulfoxide /Water with a volumetric ratio of 7:3 and acetonitrile in separate media with equal amounts of various anions. In the presence of the mentioned anionic solutions, only the solutions containing fluoride ions, made a significant change in color from pale yellow to orange-red via the –NH deprotonation mechanism, which could be detected with the naked eye. The Box-Behnken design, response surface methodology through UV-Vis spectroscopy techniques in various pH and temperatures and reaction times were tested to optimize the AR conditions. Also, a lateral flow assay test of the synthesized AR detected fluoride ions in real-life samples, including water, contrary to different sources such as toothpaste and mouthwash. Furthermore, according to the World Health Organization report on fluoride ion toxicity in water, the detection limit of the AR was lower than of the declared level.

Criteria for choosing optimal working media for the gas-dynamic separation of granular materials

Criteria for choosing optimal working media for the gas-dynamic separation of granular materials

Single-cell laser emitting cytometry for label-free nucleolus fingerprinting

The nucleolus, a recognized biomolecular condensate, serves as the hub for ribosome biogenesis within the cell nucleus. Its quantity and morphology are discernible indicators of cellular functional states. However, precise identification and quantification of nucleoli remain challenging without specific labeling, particularly for suspended cells, tissue-level analysis and high-throughput applications. Here we introduce a single-cell laser emitting cytometry (SLEC) for label-free nucleolus differentiation through light-matter interactions within a Fabry–Perot resonator. The separated gain medium enhances the threshold difference by 36-fold between nucleolus and its surroundings, enabling selective laser emissions at nucleolar area while maintaining lower-order mode. The laser emission image provides insights into structural inhomogeneity, temporal fluid-like dynamics, and pathological application. Lasing spectral fingerprint depicts the quantity and size of nucleoli within a single cell, showcasing the label-free flow cytometry for nucleolus. This approach holds promise for nucleolus-guided cell screening and drug evaluation, advancing the study of diseases such as cancer and neurodegenerative disorders.

Development of cyclodextrin-electrokinetic chromatography-based strategies for the separation of ketorolac enantiomers

The development of analytical strategies enabling the chiral separation of ketorolac by electrokinetic chromatography is presented in this work. This anti-inflammatory drug is commercialised as racemic mixture but its physiological activity resides in the S-enantiomer. Different experimental conditions were investigated at acidic and neutral pH, including the use of cyclodextrins (CD) or amino acid-based ionic liquids (AAILs) ([TMA][L-Cit], [TMA][L-Arg], [TMA][L-Harg], [TBA][L-Cit], [TBA][L-Arg], and [TBA][L-Harg]) as the sole chiral selectors or the combination of a CD with AAILs or their cationic components (tetramethylammonium (TMA-OH) or tetrabutylammonium (TBA-OH)). The best conditions in terms of migration times and enantiomeric resolutions were obtained using 2 mM heptakis(2,3,6-tri-O-methyl)-β-CD (TM-β-CD) in 50 mM phosphate buffer at pH 7.0 or 2 mM TM-β-CD with 60 mM TMA-OH in 50 mM formate buffer at pH 3.0. The presence of TMA-OH in the separation medium affected considerably the electroosmotic flow (EOF) mobility which, in turn, significantly shortened the migration times for ketorolac enantiomers at pH 3.0 due to an inversion in the EOF. The multivariate optimization of the experimental conditions for the single system and for the combined system with TMA-OH enabled to obtain the separation of ketorolac enantiomers in less than 11 min with enantiomeric resolutions of 2.5 and 1.9, respectively. The single system was selected to evaluate its analytical characteristics in terms of limits of detection/quantification, accuracy, and precision, according to the International Council for Harmonization (ICH) guidelines, which resulted adequate to be applied to the analysis of pharmaceutical formulations.

Evaluation of fluorous affinity using fluoroalkyl-modified silica gel and selective separation of poly-fluoroalkyl substances in organic solvents.

In this study, we focused on the fluorous affinity acting among fluorine compounds, and then developed a new separation medium and evaluated their performance. We prepared the stationary phases for a column using silica gel-modified alkyl fluoride and investigated the characteristics of fluorous affinity by comparing them with a typical stationary phase, which does not contain fluorine, using high-performance liquid chromatography (HPLC). In HPLC measurements, we confirmed that while all non-fluorine compounds were not retained, retention of fluorine compounds increased as the number of fluorine increased with the stationary phase. It also revealed that the strength of fluorous affinity changes depending on the types of the organic solvent; the more polar the solvent, the stronger the effect. Additionally, the stationary phase was employed to compare the efficiency of our column with that of a commercially available column, Fluofix-II. The retention selectivity was almost the same, but the absolute retention strength was slightly higher on our column, indicating that the column is available for practical use.

Determination of 13 perfluorinated and polyfluoroalkyl substances in fishes by QuEChERS-ultra-high performance liquid chromatography-tandem mass spectrometry

Perfluorinated and polyfluoroalkyl substances (PFASs) are compounds characterized by at least one perfluorinated carbon atom in an alkyl chain linked to side-chain groups. Owing to their unique chemical properties, these compounds are widely used in industrial production and daily life. However, owing to anthropogenic activities, sewage discharge, surface runoff, and atmospheric deposition, PFASs have gradually infiltrated the environment and aquatic resources. With their gradual accumulation in environmental waters, PFASs have been detected in fishes and several fish-feeding species, suggesting that they are bioconcentrated and even amplified in aquatic organisms. PFASs exhibit high intestinal absorption efficiencies, and they bioaccumulate at higher trophic levels in the food chain. They can be bioconcentrated in the human body via food (e. g., fish) and thus threaten human health. Therefore, establishing an efficient analytical technique for use in analyzing PFASs in typical fish samples and providing technical support for the safety regulation and risk assessment of fish products is necessary. In this study, by combining solvent extraction and magnetic dispersion-solid phase extraction (d-SPE), an improved QuEChERS method with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed for the determination of 13 PFASs in fish samples. Fe3O4-TiO2 can be used as an ideal adsorbent in the removal of sample matrix interference and a separation medium for the rapid encapsulation of other solids to be isolated from the solution. Based on the matrix characteristics of the fish products and structural properties of the target PFASs, Fe3O4-TiO2 and N-propyl ethylenediamine (PSA) were employed as adsorbents in dispersive purification. The internal standard method was used in the quantitative analyses of the PFASs. To optimize the sample pretreatment conditions of analyzing PFASs, the selection of the extraction solvent and amounts of Fe3O4-TiO2 and PSA were optimized. Several PFASs contain acidic groups that are non-dissociated in acidic environments, thus favoring their entry into the organic phase. In addition, acidified acetonitrile can denature and precipitate the proteins within the sample matrix, facilitating their removal. Finally, 2% formic acid acetonitrile was used as the extraction solvent, and 20 mg Fe3O4-TiO2, 20 mg PSA and 120 mg anhydrous MgSO4 were used as purification adsorbents. Under the optimized conditions, the developed method exhibited an excellent linearity (R≥0.9973) in the range of 0.01-50 μg/L, and the limits of detection (LODs) and quantification (LOQs) ranged from 0.001-0.023 and 0.003-0.078 μg/L, respectively. The recoveries of the 13 PFASs at low, medium, and high spiked levels (0.5, 10, and 100 μg/kg) were 78.1%-118%, with the intra- and inter-day precisions of 0.2%-11.1% and 0.8%-8.7%, respectively. This method was applied in analyzing real samples, and PFASs including perfluorooctanesulfonic acid, perfluorooctanoic acid, perfluoroundecanoic acid, perfluorododecanoic acid, and perfluorotridecanoic acid, were detected in all 11 samples evaluated. This method is simple, sensitive, and suitable for use in analyzing PFASs in fish samples.

Streamlined integrated protein isoelectric focusing using microfluidic paper-based device

An innovative integrated paper-based microdevice was developed for protein separation by isoelectric focusing (IEF), allowing for robust design thanks to a 3D-printed holder integrating separation channel, reservoirs, and electrodes. To reach robustness and precision, the optimization focused on the holder geometry, the paper nature, the reservoir design, the IEF medium, and various focusing parameters. A well-established and stable pH gradient was obtained on a glass-fiber paper substrate with simple sponge reservoirs, and the integration of the electrodes in the holder led to a straightforward system. The separation medium composed of water/glycerol (85/15, v/v) allowed for reducing medium evaporation while being an efficient medium for most hydrophobic and hydrophilic proteins, compatible with mass spectrometry detection for further proteomics developments. To our knowledge, this is the first report of the use of glycerol solutions as a separation medium in a paper-based microdevice. Analytical performances regarding pH gradient generation, pI determination, separation efficiency, and resolution were estimated while varying the IEF experimental parameters. The overall process led to an efficient separation within 25 min. Then, this methodology was applied to a sample composed of saliva doped with proteins. A minimal matrix effect was evidenced, underscoring the practical viability of our platform. This low-cost, versatile and robust paper-based IEF microdevice opens the way to various applications, ranging from sample pre-treatment to integration in an overall proteomic-on-a-chip device.

Regulation of macroporous cellulose microspheres via phase separation force induced by carbon nanotubes doping for enhanced protein adsorption

The burgeoning requirement for purified biomacromolecules in biopharmaceutical industry has amplified the exigency for advanced chromatographic separation techniques. Herein, macroporous cellulose microspheres (CCMs) with micron-sized pores are produced by a facile regulation via carbon nanotubes (CNTs). In this strategy, the incorporation of CNTs breaks the homogeneous regeneration of the cellulose, thus providing anisotropic phase force to produce macropores. The CCMs have manifested a faster mass transfer rate and more available adsorption sites owing to well-defined macropores (2.69 ± 0.57 μm) and high specific surface area (147.47 m2 g−1). Further, CCMs are functionalized by quaternary ammonium salts (GTAc-CCMs) and utilized as anion adsorbents to adsorb pancreatic kininogenase (PK). The prepared GTAc-CCMs show rapid adsorption kinetics for PK at pH 6.0, reaching 90 % equilibrium within 60 min. Also, GTAc-CCMs for PK exhibit high adsorptive capacity (632.50 mg g−1), excellent recyclability (> 80 % removal amount after 10 cycles) and selectivity especially at pH 6.0. Notably, the GTAc-CCMs have been successfully applied in a fixed-bed chromatography process, indicating their potential as an effective chromatographic medium for rapid separation of biomacromolecules.

Cotton fiber coated with a novel lysozyme-polymer brush conjugates for efficient oil-water separation

In this work, for the first time, a conjugate was generated by grafting poly(oligo(ethylene glycol)methacrylate) (POEGMA) on lysozyme (Lyso). Followed by a phase transition of Lyso (PTL) in the presence of tris(2-carboxyethyl)phosphine (TCEP), the resulting new film (PTL-POEGMA) was coated on cotton fibers to give PTL-POEGMA@cotton fiber. PTL-POEGMA film improved hydrophilicity and underwater superoleophobicity (underwater contact angle greater than 150º) of cotton fiber, which has good separation effect on oil-water mixture (with a separation efficiency of more than 99 %). In addition, the PTL-POEGMA@cotton fiber also has efficient antimicrobial adhesion effect and anti-oil (dichloromethane as an example) adhesion effect. Modified cotton fibers are expected to be used in the oil-water separation process of wastewater treatment. This PTL-POEGMA film is expected to be a new and effective modified material for oil-water separation medium.

Asymmetric catalytic synthesis of chiral covalent organic framework composite (S)-DTP-COF@SiO2 for HPLC enantioseparations by normal-phase and reversed-phase chromatographicmodes.

A novel CCOF core-shell composite material (S)-DTP-COF@SiO2 was prepared via asymmetric catalytic and in situ growth strategy. The prepared (S)-DTP-COF@SiO2 was utilized as separation medium for HPLC enantioseparation using normal-phase and reversed-phase chromatographicmodes, which displays excellent chiral separation performance for alcohols, esters, ketones, and epoxides, etc. Compared with chiral commercial chromatographic columns (Chiralpak AD-H and Chiralcel OD-H columns) and some previously reported chiral CCOF@SiO2 (CC-MP CCTF@SiO2 and MDI-β-CD-modified COF@SiO2)-packed columns, there are 4, 3, 13, and 15 tested racemic compounds that could not be resolved on the Chiralpak AD-H column, Chiralcel OD-H column, CC-MP CCTF@SiO2 column, and MDI-β-CD-modified COF@SiO2 column, respectively, which indicates that the resolution effect of (S)-DTP-COF@SiO2-packed column can be complementary tothe other ones. Theeffects of the analyte mass, column temperature, and mobile phase composition on the enantiomeric separation were investigated. The chiral column exhibits good reproducibility after multiple consecutive injections. The RSDs (n = 5) of the peak area and retention time were less than 1.5% for repetitive separation of 2-methoxy-2-phenylethanol and 1-phenyl-1-pentanol. The chiral core-shell composite (S)-DTP-COF@SiO2 exhibited good enantiomeric separation performance, which not only demonstrates its potential as a novel CSP material in HPLC but also expands the range of applications for chiral COFs.

Cryogel with Modular and Clickable Building Blocks: Toward the Ultimate Ideal Macroporous Medium for Bacterial Separation.

The lack of practical platforms for bacterial separation remains a hindrance to the detection of bacteria in complex samples. Herein, a composite cryogel was synthesized by using clickable building blocks and boronic acid for bacterial separation. Macroporous cryogels were synthesized by cryo-gelation polymerization using 2-hydroxyethyl methacrylate and allyl glycidyl ether. The interconnected macroporous architecture enabled high interfering substance tolerance. Nanohybrid nanoparticles were prepared via surface-initiated atom transfer radical polymerization and immobilized onto cryogel by click reaction. Alkyne-tagged boronic acid was conjugated to the composite for specific bacteria binding. The physical and chemical characteristics of the composite cryogel were analyzed systematically. Benefitting from the synergistic, multiple binding sites provided by the silica-assisted polymer, the composite cryogel exhibited excellent affinity toward S. aureus and Salmonella spp. with capacities of 91.6 × 107 CFU/g and 241.3 × 107 CFU/g in 0.01 M PBS (pH 8.0), respectively. Bacterial binding can be tuned by variations in pH and temperature and the addition of monosaccharides. The composite was employed to separate S. aureus and Salmonella spp. from spiked tap water, 40% cow milk, and sea cucumber enzymatic hydrolysate, which resulted in high bacteria separation and demonstrated remarkable potential in bacteria separation from food samples.

Screening, identification, and characterization of molds for brewing rice wine: Scale-up production in a bioreactor.

Rice wine, well known for its unique flavor, rich nutritional value, and health benefits, has potential for extensive market development. Rhizopus and Aspergillus are among several microorganisms used in rice wine brewing and are crucial for determining rice wine quality. The strains were isolated via Rose Bengal and starch as a combined separation medium, followed by oenological property and sensory evaluation screening. The strain exhibiting the best performance can be screened using the traditional rice wine Qu. The strains YM-8, YM-10, and YM-16, which exhibited strong saccharification and fermentation performance along with good flavor and taste, were obtained from traditional rice wine Qu. Based on ITS genetic sequence analysis, the YM-8, YM-10, and YM-16 strains were identified as Rhizopus microsporus, Rhizopus arrhizus, and Aspergillus oryzae. The optimum growth temperature of each of the three strains was 30°C, 32°C, and 30°C, and the optimum initial pH was 6.0, 6.5, and 6.5, respectively. The activities of α-amylase, glucoamylase, and protease of YM-16 were highest at 220.23±1.88, 1,269.04±30.32, and 175.16±1.81 U/g, respectively. The amino acid content of rice wine fermented in a 20-L bioreactor with the three mold strains was higher than that of the control group, except for arginine, which was significantly lower than that of the control group. The total amino acid content and the total content of each type of amino acid were ranked as YM-16 > YM-8 > YM-10 > control group, and the amino acid content varied greatly among the strains. The control group had a higher content, whereas YM-8 and YM-16 had lower contents of volatile aroma components than the control group and had the basic flavor substances needed for rice wine, which is conducive to the formation of rice wine aroma. This selected strain, YM-16, has strong saccharification and fermentation ability, is a rich enzyme system, and improves the flavor of rice wine, thereby demonstrating its suitability as a production strain for brewing.

In Migratio Noncovalent Fluorophore Labeling of Proteins by Propidium Iodide in Sodium Dodecyl Sulfate Capillary Gel Electrophoresis.

Sodium dodecyl sulfate capillary gel electrophoresis is one of the frequently used methods for size-based protein separation in molecular biology laboratories and the biopharmaceutical industry. To increase throughput, quite a few multicapillary electrophoresis systems have been recently developed, but most of them only support fluorescence detection, requiring fluorophore labeling of the sample proteins. To avoid the time-consuming derivatization reaction, we developed an on-column labeling approach utilizing propidium iodide for the first time in SDS-CGE of proteins, a dye only used before for nucleic acid analysis. As a key ingredient of the gel-buffer system, the oppositely migrating positively charged propidium ligand in migratio complexes with the SDS-proteins, therefore, supports in situ labeling during the electrophoretic separation process, not requiring any extra pre- or postcolumn derivatization step. A theoretical treatment is given to shed light on the basic principles of this novel online labeling process, also addressing the influence of propidium iodide on the electroosmotic flow, resulting in reduced retardation. The concept of propidium labeling in SDS-CGE was first demonstrated using a commercially available protein sizing ladder ranging from 6.5 to 200 kDa with different isoelectric points and post-translational modifications. Considering the increasing number of protein therapeutics on the market next, we focused on the labeling optimization of a therapeutic monoclonal antibody and its subunits, including the addition of the nonglycosylated heavy chain. Peak efficiency and resolution were compared between noncovalent and covalent labeling. The effect of ligand concentration on the effective and apparent electrophoretic mobility, the resulting peak area, and the resolution were all evaluated in view of the theoretical considerations. The best detection sensitivity for the intact monoclonal antibody was obtained by using 200 μg/mL propidium iodide in the separation medium (LOD 2 μg/mL, 1.35 × 10-8 M) with excellent detection linearity over 3 orders of magnitude. On the other hand, the resolution between the biopharmaceutical protein test mixture components containing the intact and subunit fragments of the therapeutic monoclonal antibody was very good in the ligand concentration range of 50-200 μg/mL, but using the local maximum at 100 μg/mL for the nonglycosylated/glycosylated heavy chain pair is recommended. The figures of merit, including precision, sensitivity, detection linear range, and resolution for a sample mixture in hand, can be optimized by varying the propidium iodide concentration in the gel-buffer system, as demonstrated in this paper.