Glycerol Solution Research Articles

Optimizing Glycerin-to-water Ratios for Preserving Eucalyptus Foliage

Fresh eucalyptus stems can be preserved via systemic absorption of glycerin, but the optimal rate of glycerin and its effect on foliage color and stem pliability during holding have not been well-described. We harvested stems of Eucalyptus pulverulenta ‘Baby Blue’ and treated them in solutions of 0% (control), 25%, 50%, and 75% glycerin:reverse-osmosis water for 2 weeks. Leaf greenness was measured nine times during this period; the change in stem weights and solution uptake were measured as well. Stem pliability was evaluated after 2 weeks in solution as well as 1 week after holding the stems dry. The 25% and 50% glycerin treatments increased stem weight, whereas the control and 75% treatments decreased stem weight. The glycerin treatments absorbed less than 50 mL solution per three stems during 2 weeks, whereas those in the control absorbed >270 mL water. The color of foliage was similar during the first 5 days in treatment solutions, but stems in 25% and 50% glycerin treatments were less green than those in the control and 75% treatments by day 6, and this trend continued. No difference occurred in stem pliability among treatments after 2 weeks in glycerin solutions; however, after 1 week of holding, the top 9 cm of stems in glycerin treatments were more pliable than those in the control. Based on these results, we recommend a rate of 25% glycerin to preserve eucalyptus foliage for use in botanical artistry.

Evaluation of the bactericidal activity of plasma-activated NaCl solution (PAN) against foodborne pathogens: Inactivation mechanism and application to mackerel

The objective of this study was to assess the bactericidal effect of plasma-activated NaCl solution (PAN) against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes and apply PAN as a brine salting solution for mackerel. To enhance the bactericidal effect of plasma-activated water (PAW), NaCl solutions (0, 3.5, 7, and 10 %) were treated with plasma for 20 and 40 min to generate PAN. Plasma-activated glycerol solution (PAG) was also included to evaluate the influence of water activity on plasma activation and its effect on microbial activity. Physicochemical analysis revealed that elevating the NaCl concentration of PAN led to a decrease in pH, an increase in oxidation–reduction potential, and higher levels of reactive species such as H2O2 and HOCl. PAN showed greater antibacterial activity compared to PAW and PAG, except for L. monocytogenes, where 40 min activation time and treatment time exceeding 20 min was required for significantly higher reduction to occur. PAN exhibited greater antibacterial activity at higher NaCl concentrations, which was attributed to increased ionic strength and reactive chlorine species. Additionally, we evaluated the microbial mechanisms of PAN by assessing cellular damage and alterations. The common observation across the three pathogens was that PAN resulted in increased cell membrane damage, reduced intermembrane enzyme activity, higher intracellular ROS levels, and changes in zeta potential values, while DNA damage was observed only in PAN-treated L. monocytogenes. Furthermore, when PAW and PAN were stored for up to four weeks, PAN showed higher efficacy compared to PAW. 10 % PAN was also effective against foodborne pathogens on mackerel, achieving log reductions of 3.62 for E. coli O157:H7, 4.62 for S. Typhimurium, and 3.18 for L. monocytogenes after a 20 min treatment without adversely affecting quality. Our results demonstrated the antibacterial activity and action mechanism of PAN, presenting its potential application in the seafood industry.

Enhancing the Reliability of NO2 Monitoring Using Low-Cost Sensors by Compensating for Temperature and Humidity Effects

The study investigates methods to enhance the reliability of NO2 monitoring using low-cost electrochemical sensors to measure gaseous pollutants in air by addressing the impacts of temperature and relative humidity. The temperature within a plastic container was controlled using an internal mica heater, an external hot air blower, or cooling packs, while relative humidity was adjusted using glycerine solutions. Findings indicated that the auxiliary electrode signal is susceptible to temperature and moderately affected by relative humidity. In contrast, the working electrode signal is less affected by temperature and relative humidity; however, adjustments are still required to determine gas concentrations accurately. Tests involving on/off cycles showed that the auxiliary electrode signal experiences exponential decay before stabilizing, requiring the exclusion of initial readings during monitoring activities. Additionally, calibration experiments in zero air allowed the determination of the compensation factor nT across different temperatures and humidity levels. These results highlight the importance of compensating for temperature and humidity effects to improve the accuracy and reliability of NO2 measurements using low-cost electrochemical sensors. This refinement makes the calibration applicable across a broader range of environmental conditions. However, the experiments also show a lack of repeatability in the zero air calibration.

Cooperative and Local Molecular Motion of High-Density Water in Glycerol Aqueous Solutions.

The glass-to-liquid transition of water, particularly in high-density water (HDW), has long been a controversial topic due to challenges posed by inevitable crystallization. In this study, we addressed this issue by creating homogeneous high-density glass from a dilute glycerol aqueous solution under high pressure. Using dielectric spectroscopy, we explored the glass transition of HDW in glycerol solutions across the full concentration range under high pressures. HDW was found to exhibit two distinct relaxation modes: one linked to cooperative motion and the other to noncooperative local motion. The fragility index classification of HDW, derived from the cooperative motion of water, suggests that HDW behaves as a "fragile" liquid, contradicting previous suggestions. Extrapolation to pure HDW indicates that the dielectric relaxation observed in pure HDW originates from noncooperative local water motion.

Extraction and Counter-Current Separation of Phenylpropanoid Glycosides from Pedicularis oederi Vahl by Deep Eutectic Solvent

Deep eutectic solvents (DESs) are mixtures of organic compounds displaying excellent solvent properties while keeping an ecofriendly character. In this study, DESs have been applied to the extraction of phenylpropanoid glycosides from Pedicularis oederi Vahl, successively separated by means of counter-current chromatography. Firstly, the ultrasonic-assisted extraction conditions were optimized by response surface methodology, and the results showed phenylpropanoid glycosides could be well extracted under the optimized extraction conditions with deep eutectic solvents. Then, the sample was separated by counter-current chromatography using ethyl acetate/aqueous solution of choline chloride and glycerol (6:6, v/v) as the solvent system. In about 360 min, four phenylpropanoid glycosides, including 31.6 mg of echinacoside, 65.3 mg of Jionoside A1, 28.9 mg of Forsythoside B, 74.1 mg of verbascoside, and 21.2 mg of kaempferol-3-O-rutinoside were obtained from about 900 mg of the sample. It revealed deep eutectic solvents could be well employed as a green solvent for the extraction and counter-current separation of natural products.

Paintable, Fast Gelation, Highly Adhesive Hydrogels for High-fidelity Electrophysiological Monitoring Wirelessly.

High-fidelity wireless electrophysiological monitoring is essential for ambulatory healthcare applications. Soft solid-like hydrogels have received significant attention as epidermal electrodes because of their tissue-like mechanical properties and high biocompatibility. However, it is challenging to develop a hydrogel electrode that provides robust contact and high adhesiveness with glabrous skin and hairy scalp for high-fidelity, continuous electrophysiological signal detection. Here, a paintable, fast gelation, highly adhesive, and conductive hydrogel is engineered for high-fidelity wireless electrophysiological monitoring. The hydrogel, consisting of gelatin, gallic acid, sodium citrate, lithium chloride, glycerol, and Tris-HCl buffer solution exhibits a reversible thermal phase transition capability, which endows it with the attributes of on-skin applicability and fast in situ gelation with 15 s, thereby addressing the aforementioned limitations. The introduction of gallic acid enhances the adhesive properties of the hydrogel, facilitating secure electrode attachment to the skin or hairy scalp. To accentuate the potential applications in at-home electrophysiological health monitoring, the hydrogel electrodes are demonstrated for high-fidelity electrocardiogram recording for one hour during various daily activities, as well as in simultaneous electroencephalogram and electrocardiogram recording during a 30 min nap.

Fully Physically Crosslinked Hydrogel with Ultrastretchability, Transparency, and Freezing-Tolerant Properties for Strain Sensor.

Nowadays, conductive hydrogels show significant prospects as strain sensors due to their good stretchability and signal transduction abilities. However, traditional hydrogels possess poor anti-freezing performance at low temperatures owing to the large number of water molecules, which limits their application scope. To date, constructing a hydrogel-based sensor with balanced stretchability, conductivity, transparency, and anti-freezing properties via simple methods has proven challenging. Here, a fully physically crosslinked poly(hydroxyethyl acrylamide)-glycerol-sodium chloride (PHEAA-Gl-NaCl) hydrogel was obtained by polymerizing hydroxyethyl acrylamide in deionized water and then soaking it in a saturated NaCl solution of glycerol and water. The PHEAA-Gl-NaCl hydrogel had good transparency (~93%), stretchability (~1300%), and fracture stress (~287 kPa). Owing to the presence of glycerol and sodium chloride, the PHEAA-Gl-NaCl hydrogel had good anti-freezing properties and conductivity. Furthermore, the PHEAA-Gl-NaCl hydrogel-based strain sensor possessed good sensitivity and cyclic stability, enabling the detection of different human motions stably and in a wide temperature range. Based on the above characteristics, the PHEAA-Gl-NaCl hydrogel has broad application prospects in flexible electronic materials.

Increasing the Wear and Corrosion Resistance of a CP-Ti Surface by Plasma Electrolytic Borocarburizing and Polishing

The paper examines the possibility of increasing the wear and corrosion resistance of a CP-Ti surface by duplex plasma electrolytic treatment (borocarburizing and polishing). The structure and composition of diffusion layers, their microhardness, surface morphology and roughness, wear resistance during dry friction and corrosion resistance in Ringer’s solution were studied. The formation of a surface-hardened layer up to 200 μm thick with a microhardness of up to 950 HV, including carbides and a solid solution of boron and carbon, is shown. Subsequent polishing makes it possible to reduce surface roughness and remove weak areas of the porous oxide layer, which are formed during high-temperature oxidation in aqueous electrolyte vapor during borocarburizing. Changing the morphology and structural-phase composition of the CP-Ti surface helps reduce weight wear by a factor of three (the mode of frictional interaction changes from microcutting to oxidative wear) and corrosion current density by a factor of four after borocarburizing in a solution of boric acid, glycerin and ammonium chloride at 950 °C for 5 min and subsequent polishing in an ammonium fluoride solution at a voltage of 250 V for 3 min.

The effect of temperature-dependent drug viscosity on needle-free jet injection

Highly viscous drugs cannot be delivered through a needle. Typically, this means that these drugs are formulated at lower concentrations, demanding higher delivery volumes, which often must be delivered intravenously. Jet injection may provide an important solution for viscous drug delivery. Jet injection is a needle-free drug delivery technique whereby a liquid drug is formed into a hair-thin (∼200 µm) high-speed (>100 m/s) jet that penetrates and delivers itself into tissue. While it may seem that it would be just as difficult to form a viscous drug into a high-speed jet as it is to force it down a needle, this is not the case. Recent work has revealed that ‘viscous-heating’ during jet injection can result in significant temperature increase, and resultant viscosity decrease, in a thin outer-layer of the jet; this phenomenon effectively results in the drug ‘self-lubricating’ as it passes through a jet injection orifice. Despite the potential for this finding to revolutionise the subcutaneous delivery of high-viscosity drugs, little further work in this area has since been reported on. In this work we develop finite element models of needle-free injection to investigate how viscous heating affects jet production, how heat exchange with the orifice material influences this process, and to what extent jet production is affected by the initial temperature of the fluid. We then conduct novel high-speed measurements of jet and orifice temperature changes due to viscous heating. We find that viscous heating is responsible for approximately doubling the speed of jets that can be produced with very viscous fluid (1 Pa·s) at room temperature. The thermal conductivity of the orifice can transfer heat away from the perimeter of the jet, and thus reduce the lubricating effect of viscous heating. We then show that by preheating 99 % glycerol (1 Pa·s) from 7 °C to 37 °C the jet speed can be increased 6-fold. We also demonstrate the successful delivery of a very viscous glycerol solution using preheated jet injection into ex vivo porcine tissue. Given that 99 % glycerol is 10- to 100-fold more viscous than current protein therapeutics, our findings demonstrate the potential for jet injection, with or without additional drug preheating, to deliver drug formulations, needle-free, that are much more viscous than those currently delivered through needles.

Boosting electrocatalytic urea oxidation performance of NiSx-VS4-C mediated via glycerol coking

Ni is regarded as active site for provoking urea oxidation reaction (UOR); nevertheless, monometallic Ni-based catalysts can not possess sufficiently high performance owing to poisoning susceptibility of Ni towards carbonaceous intermediates and the poor electrical conductivity. In response, NiSx-VS4-C is synthesized via a facile glycerol coking strategy in hydrothermal system. It is found that NiSx-VS4-C is composed of many nanoparticles with a relatively small size (approximately 70 nm). Besides acting as the precursor of carbon, glycerol can regulate the morphology and structure of catalysts, and promote the formation of vacancy defects. Using as catalyst for UOR, a specific current activity of 652 mA cm−2 mg−1 for NiSx-VS4-C can be achieved at 0.52 V (vs. Hg/HgO), which is much higher than that for NiSx or VS4 synthesized in glycerol solution. Glycerol coking is important for boosting catalytic activity. NiSx-VS4-C synthesized in glycerol solution exhibits much better catalytic activity than that synthesized in other alcohol solutions. Potential dependent impedance analyses reveal that urea indirect electro-oxidation mechanism should be mainly obeyed when NiSx-VS4-C is employed as catalyst. Both Ni and V with high chemical valence are active sites, where Ni species is mainly in charge of the oxidation of amine intermediate and V species is mainly in charge of the oxidation of CO intermediate. Carbon, especially graphitized phase, will significantly enhance the electrical conductivity and accelerate the charge transfer process. Therefore, constructing dual active sites and enhancing electrical conductivity via polyalcohol coking provide promising strategies for Ni-based catalysts towards UOR.

Plant-based egg washes for use in baked goods: Machine learning and visual parameter analysis.

Pea protein is one potential environmentally sustainable way of recreating the functionality of eggs in coatings for baked goods. These coatings are commonly applied to enhance visual properties of baked goods that consumers desire, especially color and gloss. This project used a simplified pie crust formulation (flour, shortening, and water) as a model baked good system to investigate color and gloss properties of pea protein coatings comprising three pea protein glycerol ratios, prepared at 2pH values, and applied at three different weights, baked for either 15 or 30 min. Pictures were also taken and used to estimate L*, a*, and b* colorimeter values from images using random forest and artificial neural network models developed using SciKit-Learn. Image acquisition was also conducted at different lighting conditions and the results are corrected utilizing a principal component analysis (PCA) weighting approach. Results show that pea protein glycerol solutions are all glossier than egg washes, and the 80%/20% ratio gives the highest glossiness. Furthermore, there are not significant differences in any of the colorimeter values at any concentration when applying 1 g of protein. The artificial neural network model coupled with PCA weighting led to reasonable estimates of color at different lighting conditions. Together, these results offer an alternative for the use of pea protein/glycerol in lieu of egg washes.

One-dimensional photonic crystal enhancing spin-to-orbital angular momentum conversion for single-particle tracking

Single-particle tracking (SPT) is an immensely valuable technique for studying a variety of processes in the life sciences and physics. It can help researchers better understand the positions, paths, and interactions of single objects in systems that are highly dynamic or require imaging over an extended time. Here, we propose an all-dielectric one-dimensional photonic crystal (1D PC) that enhances spin-to-orbital angular momentum conversion for three-dimensional (3D) SPTs. This well-designed 1D PC can work as a substrate for optical microscopy. We introduce this effect into the interferometric scattering (iSCAT) technique, resulting in a double-helix point spread function (DH-PSF). DH-PSF provides more uniform Fisher information for 3D position estimation than the PSFs of conventional microscopy, such as encoding the axial position of a single particle in the angular orientation of DH-PSF lobes, thus providing a means for 3D SPT. This approach can address the challenge of iSCAT in 3D SPT because DH-PSF iSCAT will not experience multiple contrast inversions when a single particle travels along the axial direction. DH-PSF iSCAT microscopy was used to record the 3D trajectory of a single microbead attached to the flagellum, facilitating precise analysis of fluctuations in motor dynamics. Its ability to track single nanoparticles, such as 3D diffusion trajectories of 20 nm gold nanoparticles in glycerol solution, was also demonstrated. The DH-PSF iSCAT technique enabled by a 1D PC holds potential promise for future applications in physical, biological, and chemical science.

Performance and Characterization of Seebeck Coefficient and Power Factor in CMC/Glycerin Gel Electrolyte Based Ionic Thermoelectric

Ionic thermoelectric (i-TE) materials have gained significant attention for their potential to convert low-temperature thermal energy into electrical energy. In this study, gel electrolyte-based i-TE materials have been synthesized using carboxymethyl cellulose (CMC), glycerin and H3PO4 solution as electrolyte. Analysis of thermoelectric properties such as Seebeck coefficient and power factor of the gel electrolyte has been carried out. In this study, ionic conductivity and potential difference or output voltage of CMC/glycerin gel electrolyte were measured. The results of this study indicate that the ionic conductivity and output voltage of the CMC/glycerin sample increase with temperature, whereas the Seebeck coefficient and power factor tend to decrease as the temperature gradient between the hot and cold parts of the CMC/glycerin gel electrolyte sample increases. These findings suggest that the CMC/glycerin-based polymer gel electrolyte has potential for use in i-TE devices, particularly in applications where high power output is required.

Swelling Kinetics of Hydrogel Beads in Aqueous Glycerin Solutions.

This study examines the swelling kinetics of polyacrylamide hydrogel beads in aqueous glycerin solutions of different concentrations. The total absorbed mass of the hydrogel beads remains nearly constant, independent of glycerin concentration, but the swelling process is markedly slower with increasing glycerin concentration in the aqueous solutions. Absorption capacity curves exhibit universal kinetics when time is rescaled using a characteristic time proportional to the viscosity of the solutions. Additionally, a novel visualization technique is employed to observe the core-shell structure of the hydrogel beads at early times in the swelling process. The evolution of the core-shell structure indicates a constant front velocity, which also reveals universal behavior with the same nondimensional time, suggesting a viscous dominated transport of the solution penetrating the beads.

Comparison of Different DNA Sampling and Extraction Protocols for Bacterial and Archaeal Populations Analysis in Water Buffalo

Methane (CH4) is a potent greenhouse gas, and ruminants are a significant source of agricultural emissions. It has been hypothesized that the host's genome controls rumen microbial communities, but robust results require numerous samples. The feasibility of a research project will depend on the ease and representativeness of the sampling method, as well as the cost-efficiency of large-scale sequencing. This study aimed to compare different protocols to investigate whether non-invasive samples could serve as a substitute for ruminal digesta. DNA recovery was tested in various matrices (whole rumen content, feces, and buccal swabs) from five cannulated buffalo cows. Three types of buccal swabs were tested, as well as feces in different forms (as-is, pelleted, or in a glycerol solution) and the rumen content. The study compared different protocols for DNA extraction, including WUR protocol, Maxwell®, and Quick Extract™, and two sampling times. Saliva was a challenging matrix to process, obtaining unsatisfactory DNA yield. Feces showed higher yields when pelleted but lower than rumen. The highest amount of DNA was obtained from whole rumen content using all three DNA extraction methods. Quick Extract was the easiest method to perform, while WUR resulted in the highest yield of DNA, swabs excluded. The Maxwell® method gave satisfactory results with all three matrices. However, further metagenomic analysis is required to verify if the species composition is comparable.

Protozoan intestinal invasions in military personnel of the Northern region of Ukraine

Objective — to study the prevalence and spectrum of intestinal parasitic infestations (IPI) agents in groups of military personnel of the Northern region of Ukraine, which differed according to the criteria of having symptoms of gastrointestinal disorders and passing the serving in a combat zone. Materials and methods. From February to November 2023, the study covered 302 servicemen during inpatient medical care at the Military Medical Clinical Center of the Northern Region of Ukraine. Detection and identification of intestinal parasites in samples of feces (SF) was carried out by classical methods of microscopy using the enrichment procedure (formalin‑ethyl acetate sedimentation) and the preparation (from each enriched sediment) of four smears: two thick wet with 50% aqueous solution of glycerol and D’ Anthony iodine solution; two thin, fixed, permanently stained with Whitley’s modified trichrome (mWT) or Heidenhain’s iron hematoxylin (HIH) and the modified Ziehl‑Neelsen acid method (mZN). Smear microscopy results were evaluated according to the criteria of the US Clinical and Laboratory Standards Institute. Results. It was established that the level of prevalence of IPI among the examined servicemen reached 10.6% with variation in the value of this indicator in different groups of soldiers from 2.2% to 12.6%. A specific share of protozoan monoinvasions in soldiers reached 65.6%, and mixed invasions (with two parasites at the same time) — 34.4%. Soldiers with symptoms of gastrointestinal diseases had significantly higher rates of IPI than did asymptomatic. In addition, the infestation rates among soldiers were higher in the cold season (October‑February) with a seasonality index of 1.9. All cases of IPI in servicemen (n=32) were caused by protozoan parasites (n=39), in the etiological spectrum of which the vast majority (84.6%) were pathogenic species (Blastocystis sp., Dientamoeba fragilis, Giardia lamblia), and a smaller proportion (15.4%) were commensal species (Chilomastix mesnili, Iodamoeba butschliі). Among pathogenic protozoa (n=33), Blastocystis sp. (51.5%) and D. fragilis had the highest proportion (42.4%), G. lamblia (6.1%) had significantly less one. Conclusions. Optimizing the management tactics of military medicine to reduce the negative impact of IPI on the health and combat capacity of servicemen requires knowledge about the prevalence and spectrum of pathogens of invasions among specific groups of soldiers. A necessary condition for increasing the efficiency of microscopic detection/identification of protozoan parasites (primarily D. fragilis) in the SF is the production of permanently stained (mWT or HIH) smears. Microscopic examination of such smears at high resolution (100ґ objective, oil immersion) provides an increased incidence of detection/identification of Blastocystis sp. by 47.1% and D. fragilis by 100%.

CRRT circuit venous air chamber design and intra-chamber flow dynamics: a computational fluid dynamics study

BackgroundVenous air trap chamber designs vary considerably to suit specific continuous renal replacement therapy circuits, with key variables including inflow design and filter presence. Nevertheless, intrachamber flow irregularities do occur and can promote blood coagulation. Therefore, this study employed computational fluid dynamics (CFD) simulations to better understand how venous air trap chamber designs affect flow.MethodsThe flow within a venous air trap chamber was analyzed through numerical calculations based on CFD, utilizing large eddy simulation. The working fluid was a 33% glycerin solution, and the flow rate was set at 150 ml/min. A model of a venous air trap chamber with a volume of 15 ml served as the computational domain. Calculations were performed for four conditions: horizontal inflow with and without a filter, and vertical inflow with and without a filter. Streamline plots and velocity contour plots were generated to visualize the flow.ResultsIn the horizontal inflow chamber, irrespective of filter presence, ultimately the working fluid exhibited a downstream vortex flow along the chamber walls, dissipating as it progressed, and being faster near the walls than in the chamber center. In the presence of a filter, the working fluid flowed uniformly toward the outlet, while in the absence of a filter the flow became turbulent before reaching the outlet. These observations indicate a streamlining effect of the filter.In the vertical inflow chamber, irrespective of filter presence, the working fluid flowed vertically from the inlet into the main flow direction. Part of the working fluid bounced back at the chamber bottom, underwent upward and downward movements, and eventually flowed out through the outlet. Stagnation was observed at the top of the chamber. Without a filter, more working fluid bounced back from the bottom of the chamber.ConclusionsCFD analysis estimated that the flow in a venous air trap chamber is affected by inflow method and filter presence. The “horizontal inflow chamber with filter” was identified as the design creating a smooth and uninterrupted flow throughout the chamber.

Biomechanical and histological evaluation of a prototype bovine pericardial patch for veterinary abdominal surgery: An approximation study

In veterinary medicine, especially within large animal medical and surgical clinics, addressing cavitary defects is a primary concern. In bovines, umbilical hernias are the most common defect, and surgical repair often necessitates the use of prosthetic materials. However, there is a high rate of recurrence with sutures or synthetic meshes, largely due to tissue contamination. The development of biological patches for such repairs is still in its early stages in veterinary medicine, with no commercially tested prototypes available in Argentina. Tissues derived from the extracellular matrix are considered for this purpose, with bovine pericardium standing out due to its architectural characteristics and mechanical properties. For an ideal membrane, the pericardium must retain its biomechanical properties while being unreactive and safe for the host. This study aimed to biomechanically and histologically characterize a bovine pericardium patch through all stages of processing. The treatment involved fixation with 0.5 % glutaraldehyde, immersion in an antibiotic/antimycotic solution, and detoxification and storage in a 98 % sterile glycerin solution, with three sodium phosphate-buffered washes between steps. Histological examinations and stress-strain tests were performed at each processing stage, using native pericardium as a control. Despite some minor modifications in the histological and mechanical properties, the final patches appear to be a viable alternative for resolving cavitary defects.

Wormlike Micellar Glycerol Solutions Formed from a Double-Tailed Surfactant with Two Quaternary Ammonium Head Groups.

Herein, a quaternary ammonium surfactant with dual heads and tails, N1,N1,N1,N3,N3-pentamethyl-N3-(3-(2-tetradecylhexadecanamido)propyl)propane-1,3-diaminium dibromide, abbreviated as Di-C14-N2, was synthesized. For the first time, clear observation of aggregate structures formed by surfactants in pure glycerol systems was achieved using cryogenic transmission electron microscopy (cryo-TEM). The system's rheological properties were analyzed using both steady-state shear and oscillatory rheological measurements. The lubricating efficiency of the Di-C14-N2 glycerol solution was assessed for its tribological properties using a tribological wear tester, white light interferometer, and scanning electron microscope. In glycerol, Di-C14-N2 formed long wormlike micelles, which resulted in a glycerol solution with the zero-shear viscosity of 1013 Pa·s at 90 mM, which is the most viscous glycerol system up to now. The system displayed distinct rheological properties from the aqueous system, as evidenced by two intersections in the loss and storage moduli. The formed wormlike micelles in glycerol lead to a significant alteration in the viscoelasticity of the system, thus endowing the Di-C14-N2 glycerol solution with potential as an eco-friendly lubricant. The friction coefficient of the system was found to be 23% lower and the wear rate was 83% lower than that of pure glycerol after the addition of Di-C14-N2. This demonstrates that the addition of Di-C14-N2 greatly improves the frictional properties of pure glycerol. This study offers the possibility of directly observing the aggregate structures formed by surfactants in pure glycerol systems. It contributes to the exploration of the self-assembly behavior of surfactants in nonaqueous polar media, thereby aiding in a deeper understanding of the correlation between molecular structure, mesoscale structure, and macroscopic properties.

Experimental study using phantom models of cerebral aneurysms and 4D-DSA to measure blood flow on 3D-color-coded images.

The current 3D-iFlow application can only measure the arrival time of contrast media through intensity values. If the flow rate could be estimated by 3D-iFlow, patient-specific hemodynamics could be determined within the scope of normal diagnostic management, eliminating the need for additional resources for blood flow rate estimation. The aim of this study is to develop and validate a method for measuring the flow rate by data obtained from 3D-iFlow images - a prototype application in Four-dimensional digital subtraction angiography (4D-DSA). Using phantom model and experimental circuit with circulating glycerin solution, an equation for the relationship between contrast media intensity and flow rate was developed. Applying the equation to the aneurysm phantom models, the derived flow rate was evaluated. The average errors between the derived flow rate and setting flow rate became larger when the glycerin flow and the X-rays from the X-ray tube of the angiography system were parallel to each other or when the measurement point included overlaps with other contrast enhanced areas. Although the error increases dependent on the imaging direction and overlap of contrast enhanced area, the developed equation can estimate the flow rate using the image intensity value measured on 3D-iFlow based on 4D-DSA.