Phase Conditions Research Articles

Light bullets under conditions of third harmonics generation

Abstract An analytical study of the possibility of a two-color light bullet forming during generation of the third harmonics in a graded index waveguide with the focusing Kerr nonlinearity is carried out. It is shown that under conditions of phase and group matching, as well as the absence of group velocity dispersion at the third harmonic frequency, a stable light bullet can be formed under certain restrictions. This applies to the lower limit on the temporal duration of the light bullet and to the upper limit on its power. The most stringent condition is the double restriction on the transverse radius of the light bullet.

Characterization of adeno-associated virus capsid proteins using denaturing size-exclusion chromatography coupled with mass spectrometry

Recombinant adeno-associated viruses (AAVs) are a highly effective platform for gene delivery for the treatment of many human diseases. Characterization of AAV viral protein attributes (VP), such as serotype identity, VP stoichiometry, and VP post-translational modifications, is essential to ensure product and process consistency. While size-exclusion chromatography (SEC) coupled with mass spectrometry (MS) is commonly used in the biopharmaceutical industry for analyzing protein therapeutics, its application to intact AAV VP components has not gained traction, presumably due to difficulties in achieving adequate resolution of VP(1−3) monomers. Herein, we describe the development of a denaturing SEC method and optimization of SEC parameters, including stationary phase pore size, column temperature, and mobile phase composition, to achieve effective chromatographic separation of VP(1−3). We demonstrate that an optimized dSEC-MS method featuring MS-compatible formic acid, can effectively separate VP(1−3) across AAV1, 2, 5, 6, 8, and 9 serotypes using a single column and mobile phase condition. A case study was included to showcase successful application of the dSEC-MS method in analyzing changes across different AAV production processes, yielding similar conclusions to an orthogonal approach, such as hydrophilic interaction chromatography (HILIC)- MS. Additionally, dSEC integrated with fluorescence (FLR) and ultraviolet (UV) detection can be used to semi-quantitatively identify both AAV DNA and VP components from empty and full AAV samples. Overall, this robust and MS-friendly methodological advancement could greatly streamline the development and analytical quality control processes for AAV-based gene therapies, providing a highly sensitive method for intact VP characterization.

Enhanced performance and economic feasibility of sewage sludge digestion using a two-stage anaerobic digestion with a dynamic membrane and alkaline-thermal pretreatment

This study suggests a high-rate sewage sludge anaerobic digestion (AD) process. An alkaline-thermal pretreatment and a dynamic membrane (DM) were used to enhance AD efficiency and economic feasibility in a two-stage system. The effect of pretreatment on volatile fatty acid (VFA) production in the acidogenic phase was investigated at various hydraulic retention times (HRT). After optimizing the acidogenic phase condition (HRT of 3 days), single- and two-stage AD processes with DM modules were operated simultaneously to compare performance. The highest methane production rates of 0.69 L/L/d for single-stage AD and 1.10 L/L/d for two-stage AD were observed at a total HRT of 12 days. Phase separation enhanced the growth of acetoclastic methanogens. A techno-economic analysis showed that the two-stage AD system would achieve a positive net present value within 2 years. This study demonstrated the feasibility of high-rate AD systems for sewage sludge using DM, alkaline-thermal pretreatment, and phase separation.

High-flux polyamide nanofiltration membranes tuning by polydopamine-modified boron nitride nanosheets: Accelerating Mg2+/Li+ separation

As a promising technology for lithium extraction from salt lakes, nanofiltration membranes still face challenges in balancing between permeability and selectivity. In this paper, highly dispersed functionalized boron nitride nanosheets (BNNSs-NH2) were prepared by modifying exfoliated boron nitride nanosheets (BNNSs) with polydopamine, which were incorporated into a polyamide (PA) layer by aqueous phase conditioning to prepare positively charged polyamide nanofiltration membranes. Scanning electron microscopy (SEM) showed that the PDA nanoclusters on the surface of the BNNSs can disrupt the regular stacking parallel to the membrane surface. Energy spectrum (EDS) of SEM and X-ray photoelectron spectroscopy (XPS) etching further revealed that BNNSs-NH2 were dispersed within PA layer, creating transmembrane channels for molecular diffusion. The results showed a pure water permeance of 8.55 ± 0.24 L/m2 h bar, indicating that the stabilized intercalation of BNNSs-NH2 in the PA layer synergistically improved the water permeability. Meanwhile, the retention rate of MgCl2 remained at 94 %, which was attributed to the enhanced compatibility between BNNSs-NH2 and polyamide matrix by the polydopamine coating (PDA) on the surface, as well as the Dornan effect repulsion by the enhanced positive charge on the membrane surface. After the three-stage nanofiltration of membrane, the Mg2+/Li+ ratio decreased from 50 to 0.12. Overall, this method balances permeability and selectivity by adjusting pore size and positive charge, potentially offering new ideas and insights for the preparation and development of nanofiltration membranes for Mg2+/Li+ separation.

Wettability-dependent dissolution dynamics of oxygen bubbles on Ti64 substrates

In this study, the dissolution of a single oxygen bubble on a solid surface, here Titanium alloy Ti64, in ultrapure water with different oxygen undersaturation levels is investigated. For that purpose, a combination of shadowgraph technique and planar laser-induced fluorescence is used to measure simultaneously the changes in bubble geometry and in the dissolved oxygen concentration around the bubble. Two different wettabilities of the Ti64 surface are adjusted by using plasma-enhanced chemical vapor deposition. The dissolution process on the solid surface involves two distinct phases, namely bouncing of the oxygen bubble at the Ti64 surface and the subsequent dissolution of the bubble, primarily by diffusion. By investigating the features of oxygen bubbles bouncing, it was found that the boundary layer of dissolved oxygen surrounding the bubble surface is redistributed by the vortices emerging during bouncing. This establishes the initial conditions for the subsequent second dissolution phase of the oxygen bubbles on the Ti64 surfaces. In this phase, the mass transfer of O2 proceeds non-homogeneously across the bubble surface, leading to an oxygen accumulation close to the Ti64 surface. We further show that the main factor influencing the differences in the dynamics of O2 bubble dissolution is the variation in the surface area of the bubbles available for mass transfer, which is determined by the substrate wettability. As a result, dissolution proceeds faster at the hydrophilic Ti64 surface due to the smaller contact angle, which provokes a larger surface area.

New Class of Ionic Liquid Crystal Proposed by Using Quantum Chemical Calculation

AbstractThe current investigation conducts a thorough analysis of the nonlinear optical properties, binding characteristics, and electronic features of 1‐proplene‐3‐methylimidazolium (PMIM)‐X ionic liquid (IL) crystal. These findings reveal that the dissociation energy of PMIM‐X indicates a preference for ionic dissociation over neutral dissociation. Notably, the ionic dissociation energy shows an increasing trend with both the electron affinity (EA) and the size of X. In the process of forming the IL crystal PMIM‐X, this study observes a charge transfer from PMIM to X species. It is noteworthy that the extent of charge transfer intensifies with the increasing size of X. Additionally, the calculated energy gap exhibits a positive correlation with both EA and the size of X. Although these results suggest promising nonlinear optical behavior for PMIM‐X, it is crucial to acknowledge the limitations of the study. All calculations are conducted on single atoms in the gas phase, overlooking potential effects that may arise in the liquid phase or bulk conditions. Therefore, future investigations should consider these factors for a more comprehensive understanding of the behavior of PMIM‐X in practical applications.

Uncertainty Evaluation for Determination of Sibutramine in Health Food by HPLC-MS/MS

High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to determine the content of sibutramine in health foods according to the BJS 201701 standard Determination of Compounds such as Sibutramine in Food. By evaluating each uncertainty component, the influencing factors of the uncertainty were identified and the expanded uncertainty of sibutramine detection in health foods was provided. Using the example of illegal addition of sibutramine to health products, the HPLC-MS/MS method was used for qualitative screening and quantitative analysis of samples. The sources of uncertainty in the quantitative results were analysed, including sample weighing, sample volume determination, standard solution preparation, standard curve fitting and determination of sample repeatability. The synthetic relative standard uncertainty of the measurement results was calculated and the expanded uncertainty was reported. By optimizing the liquid phase conditions, the sample can be detected within 5 min with a linear correlation coefficient of 0.998. When the content of sibutramine in health products was 42.2 mg/kg, the extended uncertainty of the results was 4.56 mg/kg (k = 2) with a 95% confidence interval. Among the various components affecting the results of detection, the uncertainty introduced during the process of preparing the standard solution has the greatest impact on the results. A proper evaluation of the uncertainty, detailed analysis and quantification of the various sources of uncertainty can help to improve the reliability of test results.

Bias control for optical single-sideband transmitter based on single IQ modulator

The optical in-phase and quadrature modulator (IQM) is typically utilized as an optical single-sideband (SSB) transmitter for its simple structure and low cost. It requires the modulator biases to be slightly offset for generating the optical carrier. However, this poses significant challenges in the bias control circuits, as most off-the-shelf automatic bias control (ABC) modules are designed to stabilize the IQM at its carrier suppression point for coherent optical communication. In this paper, a novel arbitrary ABC scheme is proposed to stabilize the carrier-to-signal power ratio (CSPR) of an optical SSB signal over long-term operation. This scheme uses SSB rather than double-sideband (DSB) sinusoidal signals as the dither signals. It does not violate the minimum phase condition, thus avoiding performance penalties compared to the conventional ABC scheme in which the DSB dither signal is used. We also develop a closed-form expression to reveal the relationship between the control parameter in the ABC algorithm and the CSPR of the optical SSB signal. By this means, the optical SSB transmitter can automatically adjust its bias voltages and stabilize them at a given CSPR value. The experimental results with ∼80 Gb/s optical SSB signal show that our proposed ABC scheme is effective in stabilizing the bias of the IQM at any point and maintains the CSPR value of the optical SSB signal over hours. It is also shown that the proposed method leads to 1 dB improvement in the receiver sensitivity compared with the traditional ABC technique.

Nanoconfinement effect on the miscible behaviors of CO2/shale oil/surfactant systems in nanopores: Implications for CO2 sequestration and enhanced oil recovery

Currently, CO2 flooding is the most promising carbon capture, utilization, and storage (CCUS) technology in the energy industry. Understanding the nanoconfinement effect on the CO2-oil miscible process is crucial for accurately determining the minimum miscibility pressure (MMP) of CO2/oil in shale reservoirs. In this study, we conducted molecular dynamics (MD) simulations to investigate the effects of pore size, surfactants, and pore type on the MMP of nanoconfined CO2/shale oil/surfactant systems. Validations against experimental data show a deviation of 2.98 % in the CO2 MMP. The MMPs under nanoconfinement are found to be significantly lower than those in bulk phase conditions (up to 22.94 %). The simulation results reveal that decreasing pore size can enhance the miscibility of CO2 and oil by increasing the CO2 adsorption ratio, improving CO2-surfactant interactions, and inhibiting the tendency of CO2 molecules to self-aggregate. The enhancement of CO2-oil miscibility caused by surfactants is ranked by CFP > SF > SDS according to the mixing degrees (Dmix) and the spatial distribution of CO2 around surfactant molecules. In addition, pore type exhibits various abilities in influencing the MMP, owing to their different mineral surface properties and ability to influence CO2-surfactant interactions. Nanopores with stronger hydrophobicity and a denser CO2 distribution around surfactant molecules have lower MMPs. The results show that the order of MMP in terms of pore types is Quartz < Kaolinite < I/M clay. This study elaborates the micro-mechanisms of surfactant-assisted CO2-oil miscibility under nanoconfinement, offering valuable insights for effectively designing CO2 miscible flooding in shale oil reservoir development.

Development of a QAMS Analysis Method for Industrial Lanolin Alcohol Based on the Concept of Analytical Quality by Design

The Analytical Quality by Design (AQbD) concept was adopted to establish a quantitative analysis of multi-components with a single marker (QAMS) method for industrial lanolin alcohol, targeting cholesterol, lanosterol, and 24,25-dihydrolanosterol. The potential critical method parameters (CMPs) were identified as column temperature, flow rate, and gradient. Definitive screening design and statistical modeling were employed to optimize the gradient conditions of the mobile phase, column temperature, and flow rate. The Method Operable Design Region (MODR) was determined using a risk-based quantification approach. The robustness was assessed using a Plackett–Burman experimental design, followed by methodological validation. Optimal analytical conditions were as follows: acetonitrile (B)—water (A) mobile phase system; flow rate of 1.58 mL/min; detection wavelength of 205 nm; injection volume of 10 µL; and column temperature of 37 °C. A gradient elution program was implemented as follows: 0–19.0 min, 90.5% B; 19.0–25.0 min, 90.5–100% B; and 25.0–55.0 min, 100% B. Cholesterol served as an internal standard for quantifying lanosterol and 24,25-dihydrolanosterol, with relative correction factors of 0.4227 and 0.8228, respectively. This analytical method utilized only the cholesterol reference substance as an internal standard to quantify the content of cholesterol, lanosterol, and 24,25-dihydrolanosterol in industrial lanolin alcohol. It reduced the testing costs and enhanced efficiency, making it potentially suitable for widespread adoption in lanolin alcohol processing industries.

Text mining approach in chicken meat welfare

The aim of the study was to analyze the aspects affecting broiler welfare with the use of Text Mining technique. This approach converts text into numerical data and analyzes word frequency distributions, enabling the extraction of useful information and the identification of relationships between elements. Text mining has limitations, i.e. ambiguity and context sensitivity, making it difficult to capture nuanced meanings. The search was carried out with Scopus using the term "Welfare" with the keywords "Chicken", "Broiler", "Broiler chicken", and "Chicken meat", to create a database of abstracts. Text Mining and Topic Analysis were performed on the abstracts (1228 documents) using the Software R 4.3.1., analyzing also the weight of bigram and trigram. Publications on broiler welfare are present in the bibliography since 1990's, but in the last 10 years, for the interest of public opinion, the numbers of publications significantly increased (76.5% of all documents published). USA, Brazil, and Europe-27 published 60% of the documents found. The works were published in a high number of journals, but 37% of them are published in only 4 journals (Poultry Science, Animals, Applied Animal Behavior Science and Animal Welfare). Text Mining analysis identified key terms related to the slaughter phase, housing management, and environmental conditions such as light quality and quantity. Moreover, a high correlation was found between some terms, underlying the importance of the effects of rearing, slaughter phases and litter management on broiler welfare. Most of the countries focused their research on some specific topics identified by Topic Analysis, mainly genetic selection, feeding, stocking density, slaughter, and consumer perceptions. Poultry Science published the highest number of papers (18%) and the topics more investigated were growing performance, transport and slaughter, and litter management. In conclusion, the high number of publications on chicken welfare underlines the importance of broiler welfare both in Europe and in other countries, even if it is difficult to identify common research topics among the geographic areas and the evolution over the time.

Elucidating the Photophysics and Nonlinear Optical Properties of a Novel Azo Prototype for Possible Photonic Applications: A Quantum Chemical Analysis.

The photophysics and nonlinear optical responses of a novel nitrothiazol-methoxyphenol molecule were investigated using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methods with the polarizable continuum model to take the solvent effect into account. Special attention is paid to the description of the lowest absorption band, characterized as a strong π → π* state in the visible region of the spectrum. The TD-DFT emission spectrum analysis reveals a significant Stokes shift of more than 120 nm for the π → π* state in gas phase condition. The results show a great influence of the solvent polarity on the nonlinear optical (NLO) response of the molecule. Specifically, the second harmonic generation hyperpolarizability β(-2ω; ω, ω) shows a large variation from gas to aqueous solvent (82 × 10-30 to 162 × 10-30 esu), exhibiting notably higher values than those reported for standard compounds such as urea (0.34 × 10-30 esu) and p-nitroaniline (6.42 × 10-30 esu). Furthermore, a two-photon absorption analysis indicates a large cross-section (δ2PA = 77 GM) with superior performance compared to several dyes. These results make the molecule quite interesting for nonlinear optics.

Mercury enrichments as a paleo-volcanism proxy: Sedimentary bias and a critical analysis across the end-Triassic

Mercury (Hg) anomalies in sedimentary rocks have been increasingly used in paleoclimatology studies for tracing volcanic signals, as Hg emissions from volcanic activity can cause contemporaneous sedimentary Hg enrichment. However, non-volcanic sedimentary controls on Hg have clear potential to mask these signals. These factors include host phase variability linked to environmentally controlled sourcing and settling changes, and/or variable preservation conditions associated with weathering, oxidation and diagenesis. Such factors can limit the efficacy of Hg as a paleo-volcanism proxy. In this study, sedimentary effects on Hg concentration within a complex depositional system in southwest England (St. Audrie's Bay) across the end-Triassic have been analyzed, together with published data from coeval end-Triassic sections globally – an interval of time coeval with the Central Atlantic Magmatic Province (CAMP). Our statistical analysis of Hg and associated geochemical data highlights significant fluctuations in sedimentary Hg due to relative supply differences in Hg and host phases, as well as the changing types and preservation conditions of host phases. End-Triassic sections globally show a consistent undersupply of Hg relative to organic matter across the end-Triassic mass extinction (ETME). To better assess the magnitude and significance of possible Hg enrichments in sedimentary rocks, we present a statistical method for quantifying Hg anomalies to robustly distinguish Hg variations linked to host phase/depositional changes from paleo-volcanism. Our method supports the existence of transient but asynchronous Hg anomalies linked to volcanism from the CAMP across the end-Triassic in most global sections, albeit not in the St. Audrie's Bay section.

Toward Methanol Production by CO2 Hydrogenation beyond Formic Acid Formation.

ConspectusThe Paradigm shift in considering CO2 as an alternative carbon feedstock as opposed to a waste product has recently prompted intense research activities. The implementation of CO2 utilization may be achieved by designing highly efficient catalysts, exploring processes that minimize energy consumption and simplifying product purification and separation. Among possible target products derived from CO2, methanol is highly valuable because it can be used in various chemical feedstocks and as a fuel. Although it is currently produced on a plant scale by heterogeneous catalysis using a Cu/ZnO-based catalyst, a limited theoretical conversion ratio at high reaction temperatures remains an issue. In addition, a catalytic system that can be adjusted to accommodate a variable renewable energy source for the synthesis of methanol is more desirable than current continuous-operation systems, which require a reliable energy supply. Recently, significant progress has been made in the field of homogeneous catalysis, which primarily relies on an indirect route to synthesize methanol via the hydrogenation of carbonate or formate derivatives in the presence of additives and solvents. However, homogeneous catalysis is inappropriate for industrial-scale methanol production because of the inefficient separation and purification processes involved.In this Account, we demonstrate a novel approach for methanol production under mild reaction conditions by CO2 hydrogenation catalyzed by multinuclear iridium complexes under heterogeneous gas-solid phase conditions without any additives and solvents. One of the aims of this Account provides insights for overcoming the barriers for efficient CO2 hydrogenation by focusing on catalyst design, specifically by incorporating varying functionalities into the ligand. The fundamental strategy entails activating hydrogen molecule and enhancing the hydricity of the resulting metal-hydride species, which is based on the following two concepts of catalyst design: (i) Activating a metal-hydride by electronic effects; and (ii) accelerating H2 heterolysis. We have elucidated the mechanism for accelerating H2 heterolysis using a state-of-the-art catalyst that contains an actor-ligand that responds to or participates in catalysis as opposed to a classical spectator-ligand.We have also demonstrated a novel heterogeneous catalysis using a molecular catalyst as a key step for the hydrogenation of CO2 to methanol beyond formic acid formation. The dehydrogenation of formic acid as a reverse reaction of formic acid hydrogenation is strongly favored in acidic aqueous solution. To circumvent the equilibrium limitation, we have envisioned an alternative route that both prevents the liberation of formic acid into the reaction medium, and develops a multinuclear complex to facilitate the transfer of multiple reactive hydrides. The unconventional gas-solid phase catalysis is capable of preventing the liberation of formate species and promoting further hydrogenation of formic acid through multihydride transfer.This novel catalytic system, which is the fusion of a molecular catalyst in heterogeneous catalysis, provides high performance for methanol synthesis through a sophisticated catalyst design and straightforward separation processes. A detailed mechanistic analysis of molecular catalysts in the gas phase would lead to significant progress in the field of Surface Organometallic Chemistry (SOMC).

Intelligent Fuzzy Traffic Signal Control System for Complex Intersections Using Fuzzy Rule Base Reduction

In this study, the concept of symmetry is employed to implement an intelligent fuzzy traffic signal control system for complex intersections. This approach suggests that the implementation of reduced fuzzy rules through the reduction method, without compromising the performance of the original fuzzy rule base, constitutes a symmetrical approach. In recent decades, urban and city traffic congestion has become a significant issue because of the time lost as a result of heavy traffic, which negatively affects economic productivity and efficiency and leads to energy loss, and also because of the heavy environmental pollution effect. In addition, traffic congestion prevents an immediate response by the ambulance, police, and fire brigades to urgent events. To mitigate these problems, a three-stage intelligent and flexible fuzzy traffic control system for complex intersections, using a novel hybrid reduction approach was proposed. The three-stage fuzzy traffic control system performs four primary functions. The first stage prioritizes emergency car(s) and identifies the degree of urgency of the traffic conditions in the red-light phase. The second stage guarantees a fair distribution of green-light durations even for periods of extremely unbalanced traffic with long vehicle queues in certain directions and, especially, when heavy traffic is loaded for an extended period in one direction and the short vehicle queues in the conflicting directions require passing in a reasonable time. The third stage adjusts the green-light time to the traffic conditions, to the appearance of one or more emergency car(s), and to the overall waiting times of the other vehicles by using a fuzzy inference engine. The original complete fuzzy rule base set up by listing all possible input combinations was reduced using a novel hybrid reduction algorithm for fuzzy rule bases, which resulted in a significant reduction of the original base, namely, by 72.1%. The proposed novel approach, including the model and the hybrid reduction algorithm, were implemented and simulated using Python 3.9 and SUMO (version 1.14.1). Subsequently, the obtained fuzzy rule system was compared in terms of running time and efficiency with a traffic control system using the original fuzzy rules. The results showed that the reduced fuzzy rule base had better results in terms of the average waiting time, calculated fuel consumption, and CO2 emission. Furthermore, the fuzzy traffic control system with reduced fuzzy rules performed better as it required less execution time and thus lower computational costs. Summarizing the above results, it may be stated that this new approach to intersection traffic light control is a practical solution for managing complex traffic conditions at lower computational costs.

Cerebrospinal fluid soluble CD27 is a sensitive biomarker of inflammation in autoimmune encephalitis

BackgroundAutoimmune encephalitis (AE) comprises a group of rare, severe neuroinflammatory conditions. Current biomarkers of neuroinflammation are often normal in AE which therefore can be difficult to rule out in patients with seizures, cognitive and/or neuropsychiatric symptoms. Cerebrospinal fluid (CSF) soluble CD27 (sCD27) and soluble B-cell maturation antigen (sBCMA) have high sensitivity for neuroinflammation in other neuroinflammatory conditions. In this exploratory study we investigate the potential of sCD27 and sBCMA in CSF as biomarkers of neuroinflammation in AE. MethodsConcentrations of sCD27 and sBCMA were measured in CSF from 40 AE patients (20 patients were untreated (12 with anti-N-Methyl-d-Aspartate receptor antibodies (NMDA) and 8 with anti-Leucine-rich Glioma-Inactivated 1 antibodies (LGI1)), and 37 symptomatic controls (SCs). ResultsCSF concentrations of sCD27 were increased in untreated NMDA AE patients (median 1571 pg/ml; p < 0.001) and untreated LGI1 AE patients (median 551 pg/ml; p < 0.05) compared to SCs (median 250 pg/ml). CSF sBCMA was increased in untreated NMDA AE patients (median 832 pg/ml) compared to SCs (median 429 pg/ml). CSF sCD27 and sBCMA correlated with the CSF cell count. Receiver operating characteristic curve analysis of untreated AE patients versus SCs showed an area under the curve of 0.97 for sCD27 and 0.76 for sBCMA. ConclusionCSF sCD27 is a suitable biomarker of neuroinflammation in AE with an ability to discriminate patients with NMDA AE and LGI1 AE from symptomatic controls. CSF sCD27 may be suited for ruling out AE and other neuroinflammatory conditions in the early phase of the diagnostic work-up.

Low swelling and high mechanical strength organosilane hybrid polydivinylbenzene microspheres for hydrophilic interaction chromatography applications.

In this work, monodisperse organosilane hybrid polymer microspheres with a particle size of about 5µm were synthesized using seed swelling polymerization. The organosilicon reagent methacryloxypropyltrimethoxysilane was introduced into the polymer framework as a copolymerization monomer, and the crosslinking degree of the microspheres was improved by the hydrolysis-condensation reaction of siloxanes. The synthesized hybrid microspheres have good mechanical strength as well as low swelling, with swelling propensity values of 0.167 and 0.348 in methanol and acetonitrile, respectively. Hybrid microspheres modified with cysteine have a hydrophilic interaction chromatography/reversed-phase liquid chromatography mixed-mode retention mechanism. Compared to the commercial cysteine-modified silica column, the synthesized stationary phase has higher separation selectivity for partially acidic or basic samples and better basic resistance for use under high pH mobile phase conditions (at least 10).

Discrimination of double-click synthetic echoes by bottlenose dolphins: Effects of inter-highlight interval and phasea).

Two bottlenose dolphins (Tursiops truncatus) were trained to discriminate double-click synthetic "echoes" differing in inter-highlight interval (IHI). In the first experimental task, dolphins passively listened to background (S-) stimuli with constant IHI and responded on discriminating a change to target (S+) stimuli with a slightly increased IHI. The second task was similar, but the highlights were assigned random, frequency-independent phase angles. This phase randomization was designed to interfere with potential auditory cues from characteristic spectral interference patterns linked to IHI changes. Discrimination thresholds were higher with randomized phase when the S- stimuli had IHIs of 50-250 μs. Thresholds were highest and comparable at the longest S- IHIs of 375 and 500 μs and were independent of phase condition. Although dolphin detection of changes in highlight envelope timing can explain threshold patterns at 375 and 500 μs, this cue did not explain performance at IHIs less than the dolphin auditory temporal window of ∼250 μs. Modeling results suggested that phase manipulations eliminated the availability of a simple difference in spectral magnitudes at the shortest IHIs, but the perception of a time separation pitch cue may still explain the dolphins' observed threshold patterns.

Probiotic Encapsulation: Bead Design Improves Bacterial Performance during In Vitro Digestion (Part 2: Operational Conditions of Vibrational Technology).

The development of functional foods is a viable alternative for the prevention of numerous diseases. However, the food industry faces significant challenges in producing functional foods based on probiotics due to their high sensitivity to various processing and gastrointestinal tract conditions. This study aimed to evaluate the effect of the operational conditions during the extrusion encapsulation process using vibrating technology on the viability of Lactobacillus fermentum K73, a lactic acid bacterium with hypocholesterolemia probiotic potential. An optimal experimental design approach was employed to produce sweet whey-sodium alginate (SW-SA) beads with high bacterial content and good morphological characteristics. In this study, the effects of frequency, voltage, and pumping rate were optimized for a 300 μm nozzle. The microspheres were characterized using RAMAN spectroscopy, scanning electron microscopy, and confocal laser scanning microscopy. The optimal conditions for bead production were found: 70 Hz, 250 V, and 20 mL/min with a final cell count of 8.43 Log10 (CFU/mL). The mean particle diameter was 620 ± 5.3 µm, and the experimental encapsulation yield was 94.3 ± 0.8%. The INFOGEST model was used to evaluate the survival of probiotic beads under gastrointestinal tract conditions. Upon exposure to in vitro conditions of oral, gastric, and intestinal phases, the encapsulated viability of L. fermentum was 7.6 Log10 (CFU/mL) using the optimal encapsulation parameters, which significantly improved the survival of probiotic bacteria during both the encapsulation process and under gastrointestinal conditions compared to free cells.

NEW APPROACH FOR ASSURING HIGHER QUALITY OF CALCIUM OROTATE BY ESTIMATING OROTIC ACID CONTENT USING STABILITY INDICATING RP-HPLC METHOD

Calcium orotate is one of the highly prescribed calcium salts. The orotic acid content is crucial for exhibiting its high bioavailability. There are no methods available to estimate orotic acid content in calcium orotate. The primary objective of this study was to develop and validate a robust method for the estimation of orotic acid from the bulk calcium orotate. A stability indicating RP-HPLC method was developed using an isocratic condition of mobile phase comprising 20 mM of monobasic potassium phosphate in water (pH 2.5) with phosphoric acid at a flow rate of 1 mL min-1 over C-18 (ODS, 250 × 4.6 mm) column at ambient temperature with UV detection at 214 nm. It was validated with respect to accuracy, specificity, precision, linearity, range, robustness and system suitability. Real sample analysis was also performed to test the applicability for regular analysis of calcium orotate bulk samples to assure its quality.