Forming Homogeneous Three-Dimensional Structures from Discrete Silica Microspheres Using Sub/Supercritical Water.

A novel technique for producing highly uniform structures from silica microspheres has been developed and tested. It is based on exploiting the temperature- and pressure-dependent solvent properties of sub/supercritical water toward silicon dioxide. The initial concept aimed to create a "hybrid" capillary chromatographic column on the border between a packed and a monolithic column that would combine the benefits of both.

Monte Carlo-Simulated Annealing and Machine Learning-Based Funneled Approach for Finding the Global Minimum Structure of Molecular Clusters.

Understanding the physical underpinnings and geometry of molecular clusters is of great importance in many fields, ranging from studying the beginning of the universe to the formation of atmospheric particles. To this end, several approaches have been suggested, yet identifying the most stable cluster geometry (i.e.

Effect of Field Trial on Silymarin Complex Composition and Antioxidant Assessment of Milk Thistle (Silybum marianum L. Gaertner).

Plant foods are receiving increasing attention as a valuable source of health beneficial compounds. Understanding the impact of growing conditions on the quality of milk thistle is critical for determining appropriate agro-ecological and agro-economic parameters for its production and, subsequently, food products rich in health-beneficial compounds. For this purpose, a randomized milk thistle cultivation trial was established in the experimental field of Agritec Plant Research Plc.

Capillary electrophoretic methods for classification of methicillin-resistant Staphylococcus aureus (MRSA) clones.

This study describes differentiation of methicillin-resistant Staphylococcus aureus (MRSA) isolates belonging to different genotype groups by the combination of electrophoretic techniques, transient isotachophoresis and micellar electrokinetic chromatography. MRSA isolates were separated in fused silica capillary with roughened inner surface prepared by etching with supercritical water. Separation temperature together with the rinsing procedure of the capillary turned out to be the key factors of successful analysis.

Classification of clinical Cutibacterium acnes isolates at phylotype level by capillary electrophoretic methods in roughened fused silica capillary.

Despite being commensal bacterium involved in the maintenance of healthy skin, Cutibacterium acnes is also associated with inflammatory diseases. Since inflammatory and immunogenic properties vary between C. acnes phylotypes, reliable classification of clinical C.

Fabrication of monolithic capillary columns with inner diameter 50-530 μm employing a mixture of pentaerythritol tetraacrylate and polyhedral oligomeric silsesquioxane-methacrylate as crosslinkers.

Highly crosslinked monolithic capillary columns with inner diameters in the range of 50-530 μm were prepared by radical polymerization of pentaerythritol tetraacrylate, polyhedral oligomeric silsesquioxane-methacrylate, and n-octadecyl methacrylate in the presence of methanol, dodecyl alcohol, and polyethylene glycol lauryl ether. Columns were evaluated by inverse size-exclusion chromatography employing a set of polystyrene standards of narrow molecular-size distribution and by scanning electron microscopy. Chromatographic performance under reversed-phase conditions was also evaluated.

Sensitive identification of milk protein allergens using on-line combination of transient isotachophoresis/micellar electrokinetic chromatography and capillary isoelectric focusing in fused silica capillary with roughened part.

A method for on-line concentration of milk proteins from large sample volumes using combination of transient isotachophoresis (tITP) and micellar electrokinetic chromatography (MEKC) in fused silica capillary with an inner roughened part has been developed. The method utilizes reversible dynamic adsorption of proteins onto a thin layer of PEG 4000 on the roughened surface of the capillary. In addition, the tITP/MEKC method was combined with capillary isoelectric focusing (CIEF) for on-line concentration, separation, identification and sensitive determination of proteins in skimmed milk.

Bacteriophage replication on permissive host cells in fused silica capillary with nanostructured part as potential of electrophoretic methods for developing phage applications.

Phage therapy could offer a safe and effective alternative to antibiotic treatment of infections caused by Gram-positive bacterium Staphylococcus aureus that have emerged as a significant threat in hospital and community environment and is attracting growing interest among clinicians. The legislation process of approving the phage therapeutics by pharmaceutical authorities requires rapid analytical techniques for assessment of phage activity. Here, we present a three-step method for on-line monitoring the phage effect on bacterial cells dynamically adhered from microliter volumes of high conductivity matrix onto the inner surface of fused silica capillary with a part etched with supercritical water.

Rapid Isolation, Propagation, and Online Analysis of a Small Number of Therapeutic Staphylococcal Bacteriophages from a Complex Matrix.

A method for the fast isolation, propagation, and characterization of very low count bacteriophages active against pathogenic bacterial strains is described in this study. Bacteriophages with a count of 10 phage particles were dynamically adhered from the maximum 10 mL blood plasma sample onto the nanostructured part of the fused silica capillary. One-step propagation of phage particles of genus inside the etched capillary on 10 host cells increased their number to 6 × 10 phage particles.

Identification of Conidia in Bronchoalveolar Lavage Using Offline Combination of Capillary Electrophoresis in Supercritical Water-Treated Fused Silica Capillary and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry.

Diagnosis of fungal infection in lung parenchyma is relatively difficult. Bronchoscopy with bronchoalveolar lavage is very useful in its diagnosing. Therefore, a method for rapid online concentration and analysis of conidia in bronchoalveolar lavage fluid using the combination of transient isotachophoresis (tITP) and micellar electrokinetic chromatography (MEKC) with subsequent off-line identification of the separated conidia by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is described in this study.

Nano-etched fused-silica capillary used for on-line preconcentration and electrophoretic separation of bacteriophages from large blood sample volumes with off-line MALDI-TOF mass spectrometry identification.

The properties of staphylococcal phages from the Siphoviridae, Podoviridae, and Myoviridae families were monitored using capillary electrophoretic methods on fused-silica capillaries with different morphology of surface roughness. Isoelectric points of the examined phages were determined by capillary isoelectric focusing in the original, smooth fused-silica capillary, and they ranged from 3.30 to 3.

Online Concentration of Bacteria from Tens of Microliter Sample Volumes in Roughened Fused Silica Capillary with Subsequent Analysis by Capillary Electrophoresis and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry.

This study presents a timely, reliable, and sensitive method for identification of pathogenic bacteria in clinical samples based on a combination of capillary electrophoresis with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. In this respect, a part of a single-piece fused silica capillary was etched with supercritical water with the aim of using it for static or dynamic cell-surface adhesion from tens of microliter sample volumes. The conditions for this procedure were optimized.

Immobilization of natural lipid biomembranes and their interactions with choline carboxylates. A nanoplasmonic sensing study.

The cell membrane is mainly composed of lipid bilayers with inserted proteins and carbohydrates. Lipid bilayers made of purified or synthetic lipids are widely used for estimating the effect of target compounds on cell membranes. However, the composition of such biomimetic membranes is much simpler than the composition of biological membranes.

Cohesive Energy Densities Versus Internal Pressures of Near and Supercritical Fluids.

Over half a century ago, Wiehe and Bagley suggested that a product of the internal pressure and molar volume of a liquid measures the energy of nonspecific intermolecular interactions whereas the cohesive energy reflects the total energy of intermolecular interactions in the liquid. This conjecture, however, has never been considered in connection with near and supercritical fluids. In this contribution, the cohesive energy density, internal pressure and their ratios are calculated from high precision equations of state for eight important fluids including water.

Supercritical water-treated fused silica capillaries in analytical separations: Status review.

Near- and supercritical water (SCW) has recently been shown to provide an unusual but effective tool to roughen the inner surface or manipulate the internal diameter of fused silica capillaries for analytical separation methods In this review, the to-date existing variants of instrumental arrangement for etching the fused silica capillaries with SCW are described, the currently accessible morphologies of SCW-etched capillaries are outlined, and both existing and prospective applications of the SCW-etched capillaries in analytical separations are briefly discussed. Relative merits of SCW and other agents to treat the inner surfaces of fused silica capillaries are also mentioned.

Pre-concentration and separation of bacteria by volume coupling electrophoresis on supercritical water-etched fused silica capillary with two segments of different internal diameters and inner surface roughnesses.

The transient isotachophoretic stacking and sweeping was used for the on-line large-volume sample pre-concentration of bacteria, Escherichia coli and Staphylococcus aureus cells (methicillin-susceptible or methicillin-resistant), in the initial stage of micellar electrokinetic chromatography using a non-ionogenic surfactant or of capillary electrophoresis, respectively. These procedures were employed in single-piece fused silica capillary etched with supercritical water with two different internal diameter segments featuring different inner surface roughness. Large volumes (maximum 2.

Fused silica capillaries with two segments of different internal diameters and inner surface roughnesses prepared by etching with supercritical water and used for volume coupling electrophoresis.

In this work, single-piece fused silica capillaries with two different internal diameter segments featuring different inner surface roughness were prepared by new etching technology with supercritical water and used for volume coupling electrophoresis. The concept of separation and online pre-concentration of analytes in high conductivity matrix is based on the online large-volume sample pre-concentration by the combination of transient isotachophoretic stacking and sweeping of charged proteins in micellar electrokinetic chromatography using non-ionogenic surfactant. The modified surface roughness step helped to the significant narrowing of the zones of examined analytes.

Bridged polysilsesquioxane-based wide-bore monolithic capillary columns for hydrophilic interaction chromatography.

The synthesis and characterization of large-bore silica-based monolithic capillary columns (0.32mm×150mm) are presented. Columns were prepared by acidic hydrolysis of a mixture containing tetramethoxysilane (TMOS) and 1,2-bis(trimethoxysilyl)ethane (BTME) in different molar ratios in the presence of polyethylene glycol and urea.

Partition Coefficients of Organics between Water and Carbon Dioxide Revisited: Correlation with Solute Molecular Descriptors and Solvent Cohesive Properties.

High-pressure phase behavior of systems containing water, carbon dioxide and organics has been important in several environment- and energy-related fields including carbon capture and storage, CO sequestration and CO-assisted enhanced oil recovery. Here, partition coefficients (K-factors) of organic solutes between water and supercritical carbon dioxide have been correlated with extended linear solvation energy relationships (LSERs). In addition to the Abraham molecular descriptors of the solutes, the explanatory variables also include the logarithm of solute vapor pressure, the solubility parameters of carbon dioxide and water, and the internal pressure of water.

Capillary electrophoresis in a fused-silica capillary with surface roughness gradient.

The electro-osmotic flow, a significant factor in capillary electrophoretic separations, is very sensitive to small changes in structure and surface roughness of the inner surface of fused silica capillary. Besides a number of negative effects, the electro-osmotic flow can also have a positive effect on the separation. An example could be fused silica capillaries with homogenous surface roughness along their entire separation length as produced by etching with supercritical water.

Molecular Insight into Long-Wavelength Fluorogenic Dye Design: Hydrogen Bond Induces Activation of a Dormant Acceptor.

The detection of chemical or biological analytes in response to molecular changes relies increasingly on fluorescence methods. Therefore, there is a substantial need for the development of improved fluorogenic dyes. In this study, we demonstrated how an intramolecular hydrogen bond activates a dormant acceptor through a charge induction between phenolic hydrogen and a heteroaryl nitrogen moiety.

Determination of methicillin-resistant and methicillin-susceptible Staphylococcus aureus bacteria in blood by capillary zone electrophoresis.

Serious bloodstream infections are a significant complication in critically ill patients. The treatment of these infections has become more difficult because of the increasing prevalence of multiresistant strains, especially methicillin-resistant Staphylococcus aureus (MRSA). Rapid differentiation of low number of MRSA from methicillin-susceptible S.

Etching of glass microchips with supercritical water.

A novel method of etching channels in glass microchips with the most tunable solvent, water, was tested as an alternative to common hydrogen fluoride-containing etchants. The etching properties of water strongly depend on temperature and pressure, especially in the vicinity of the water critical point. The chips were etched at the subcritical, supercritical and critical temperature of water, and the resulting channel shape, width, depth and surface morphology were studied by scanning electron microscopy and 3D laser profilometry.

Separation of methicillin-resistant from methicillin-susceptible Staphylococcus aureus by electrophoretic methods in fused silica capillaries etched with supercritical water.

Identification and prevention of Staphylococcus aureus-caused infections may benefit from a fast and dependable method to distinguish between the methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) S. aureus strains. The current methods involving polymerase chain reaction and/or other molecular tests are usually laborious and time-consuming.