Dispersed Suspensions Research Articles

Sustainable iron-grafted cellulose fibers enable coagulant recycling and improve contaminant removal in water treatment

• Iron-grafted cellulose fibers form ultra-large flocs. • Sustainable iron-grafted cellulose fibers improved contaminant removal. • The use of functionalized cellulose fibers led to a reduction in coagulant demand. • Iron-grafted fibers can be used to retain and recycle coagulant in water treatment. • The fibers were easily recovered from sludge and reused in multiple cycles. Large amounts of expensive single-use and metal-based coagulants and synthetic flocculants are employed and lost in settled sludge during water treatment. In this work, cellulose fibers were grafted with iron (hydr)oxides and introduced as a dispersed suspension during coagulation/flocculation to simultaneously act as a super-bridging agent and adsorbent and significantly improve the treatment process. Fe-grafted fiber concentrations of 0.1–0.2 g/L resulted in super-large flocs that were separated using a traditional settling approach or a novel screening method. After floc settling or screening, the Fe-fiber-containing sludge was recovered and reused in multiple cycles of treatment, maintaining the process performance with a reduction in coagulant demand of > 60% in multiple cycles, due to the ability of the Fe-grafted fibers to recycle the coagulant. Imaging and chemical characterization of the fiber surface confirms the retention of the alum coagulant on the fibers even after multiple cycles of reuse. An analysis of the supernatant water revealed that the Fe-grafted fibers also improved the removal of natural organic matter (NOM, precursor of disinfection by-products in drinking water) and did not lead to increased soluble iron levels in the water. In addition, the fibers were capable of removing the target contaminant phosphorus from synthetic wastewater with either a reduced coagulant dose or without the presence of coagulant. Hence, we expect that this material could be an easily implementable solution to reduce natural water eutrophication associated with phosphorus in wastewater effluents. Considering their performance, versatility and low-cost, Fe-grafted fibers could be sustainably implemented in water treatment plants globally – for drinking and wastewater applications – to simultaneously deal with soluble and particulate contaminants.

Preparation and conversion mechanism of different geopolymer-based zeolite microspheres and their adsorption properties for Pb2+

In this study, geopolymer zeolite microspheres (GZMs) were prepared from metakaolin by suspension dispersion solidification and in-situ conversion method. Different GZMs were prepared by adjusting n(Na2O)/n(Al2O3), n(H2O)/n(Na2O), curing time and temperature. The data showed that NaA structure was easily formed under low temperature and low alkalinity conditions, which was transformed into sodalite (SOD) with more stable structure under high temperature and high alkalinity conditions. When n(Na2O)/n(Al2O3) = 1.9 and n(H2O)/n(Na2O) = 12, the sphericity of GZMs was the best according to the sphericity and particle size distribution results. Furthermore, different ZMs were prepared by adjusting the curing temperature and time. These ZMs showed maximum adsorption capacities for Pb2+ of 529.67 mg/g (NaA), 345 mg/g (NaA + SOD: the mixture of NaA and sodalite) and 308.30 mg/g (SOD), following pseudo-second-order kinetic model and the Langmuir isotherm model. The fresh and post-adsorption GZMs were analyzed by SEM-EDX, XRD, FTIR and XPS, and the △c (Pb2+): △c (Na+) = 1: 1.92 (≈1:2) in the solition, which confirmed chemisorption phenomenon via ion exchange mechanism. Moreover, the adsorption rate of Pb2+ on NaA ZMs was higher than that of traditional zeolite materials. This study accredited to its simplicity, low cost and remarkable adsorption performance of the NaA ZMs for Pb2+, can be deemed of potential value in practical application of wastewater processing.

Influence of emulgator nature on dispersity and stability of artificial polymer suspensions based on polycarbonate and polymethyl methacrylate

Objectives. To create stable artificial polymer suspensions with a positive charge of particles based on polycarbonate and polymethyl methacrylate using cationic surfactants and organosilicon surfactants.Methods. The size of droplets and polymer suspension particles was determined by photon correlation spectroscopy (dynamic light scattering) using a Zetasizer NanoZS laser particle analyzer (Malvern, UK).Results. Domestic cationic surfactants Katamin-AB and Azol-129 were found to be capable of producing stable artificial polycarbonate and polymethyl methacrylate suspensions. Based on the polymer, the optimal surfactant concentration was 6 wt %. The effect of polymer concentration in solution on the stability and particle size of final polymer suspensions was shown. It was determined that the polymer concentration in the solution should not exceed 10%. When obtaining a highly dispersed suspension during dispersion, a higher concentration causes an increase in the viscosity of emulsions. As a result of a synergistic effect formation, we used mixtures of cationic surfactants (Katamin-AB/Azol-138 and Azol-129/Azol-138) to enhance the stability of the final polymer suspensions. The optimal surfactant ratio was 9:1. The total concentration of the mixture is 10 wt %, based on the polymer. Polymer suspensions were stabilized with each of 2:1 mixtures of cationic surfactants Katamin-AB and Azol-129 withan organosilicon surfactant U-851. The total mixture concentration was 9 wt %, based on the polymer.Conclusions. New methods of producing artificial polycarbonate and polymethyl methacrylate suspensions in the presence of domestically produced cationic surfactants, as well cationicorganosilicon surfactants mixtures, were proposed. The colloidal-chemical properties of the obtained polymer suspensions were considered. It was found that using a 2:1 mixture of cationic and organosilicon surfactants produces polymer suspensions that are stable during production and storage.

Carboxyl-containing quinazolines and related heterocycles as carriers of anti-inflammatory activity

Active pharmaceutical ingredients whose structure combines aromatic or heterocyclic fragments with pharmacophore carboxylic group are widespread on pharmaceutical market. The isolation of COX-NSAIDs complexes and following X-ray studies allowed to explain the key role of pharmacophore carboxylic group in the formation of enzyme-ligand interactions and the effect of its presence on the activity and selectivity. The introduction of selective COX-2-inhibitors to medicinal practice resulted in a significant decrease of side effects and complication frequencies. However, the problem of NSAIDs toxicity has not been solved. Thus, the search for the novel anti-inflammatory drugs using in silico methods and approaches including structural modification of known NSAIDs by “bioisosteric” replacements of aromatic and heterocyclic fragments with other structural elements with carboxylic group as the carrier of pharmacological effect, is a current trend of medicinal chemistry. The aim of present study is to purposefully search for anti-inflammatory agents among carboxyl-containing quinazolines and related heterocycles using in silico and in vivo methods, as well as to evaluate carboxylic group effect on the level of anti-inflammatory activity. Materials and methods. Quinazoline-4(3H)-ylidene)hydrazides of mono-(di-)carboxylic acids, 2-R-[1,2,4]triazolo[1,5-c]quinazolines, 3-R-5-(2-aminophenyl)-1H-1,2,4-triazoles, 5-carboxyalkyl[1,2,4]triazolo[1,5-c]quinazolines and 2-R-7-oxo-6,7-dihydropyrrolo[1,2-a][1,2,4]triazolo[1,5-c]quinazoline-4a(5H)-carboxylic acids were screened for their anti-inflammatory activity. MarvinSketch 20.19.0, AutoDock Vina and AutoDockTools 1.5.6, HyperChem 7.5, Discovery Studio were used for in silico research. “Drug-like” characteristics were evaluated using an online service. Prediction of toxicity and Ames mutagenicity of the studied compounds were performed in silico using Test software. Evaluation of the anti-inflammatory activity of the synthesized compounds was carried out on white Wistar rats (150–160 g of weight) using carrageenan induced paw edema model. Phlogogen (1 % aqueous solution of λ-carrageenan) was subplantarly injected in the dose of 0.1 ml in the rats’ hind right paw. The left one was used as a control. The studied compounds were intragastrically administered with atraumatic probe as water solution or finely dispersed suspension stabilized by Tween-80 in the dose of 10 mg/kg 1 hour before the injection of phlogogen. The reference drug Diclofenac sodium was administered intragastrically in a recommended for pre-clinical studies dose of 8 mg/kg. The paw volume was measured before the experiment and in 4 hours after phlogogen injection. The activity of these substances was determined by their ability to reduce the swelling compared with control group and was expressed in percentage. The experiments were carried out with respect to Bioethical rules and norms. Results. The search for anti-inflammatory agents among carboxylic-containing quinazolines and related heterocycles was theoretically substantiated using results of molecular docking, druglike criteria calculations and predicted parameters of toxicity. Experimental in vivo methods (“carrageenan” test) confirmed the anti-inflammatory activity of studied compounds and showed that (quinazoline-4(3H)-ylidene)hydrazides of dicarboxylic acids inhibit edema by 17.0–50.0 %, 2-carboxyalkyl-(phenyl-)-[1,2,4]triazolo[1,5-c]quinazolines – by 0.00–40.63 %, 2-(5-(2-aminophenyl)-1H-1,2,4-triazol-3-yl)alkyl-(phenyl-)carboxylic acids – by 2.43–49.65 %, 2-R-5-carboxyalkyl[1,2,4]triazolo[1,5-c]quinazolines – by 0.47–22.93 % and 2-R-7-oxo-6,7-dihydropyrrolo[1,2-a][1,2,4]triazolo[1,5-c]quinazoline-4a(5H)-carboxylic acids – by 0.94–17.16 %. Among them, there are compounds that compete with the reference drug “Diclofenac sodium”. The SAR analysis showed that both conformation of the molecule and the nature of the “pharmacophore” moiety (carboxyalkyl residue length) at the corresponding positions of the heterocycle have a significant effect on the anti-inflammatory activity. It was shown that the test compounds, according to molecular docking visualization data, have other enzyme-ligand interactions and probably a different mechanism of activity. Conclusions. The predicted affinity values, calculated “drug-like” criteria and toxicity parameters, visualization of the docking of studied molecules in active site of biological targets as well as experimental studies results showed that investigated compounds are promising in scope of purposeful search for anti-inflammatory drugs. The conducted in vivo screening of anti-inflammatory activity among carboxyl-containing quinazolines and related heterocyclic compounds allowed to detect series of substances that by the level of anti-inflammatory activity compete with reference-compound “Diclofenac sodium” on the carrageenan-induced paw edema model. Presented data may be considered as a theoretical basis for further structural modification of studied compounds aimed on elaboration of novel anti-inflammatory agents and evaluation of their activity mechanism (lipoxygenase inhibitors, phospholipase inhibitors, etc.).

Polyethylene porous microsphere coated coaxial fiber composite membrane for high safety lithium‐ion battery

AbstractA polyetherimide/polyvinylidene fluoride (PEI/PVDF) coaxial fiber membrane coated with polyethylene (PE) porous microspheres with thermal shutdown function was prepared. The PE porous microspheres created by the suspension dispersion method are composed of a large number of pleated petal structures, which contain abundant pore structures and have a melting point of 108°C. Ionic conductivity test, scanning electron microscope test, open circuit voltage test, and cycle performance test show that the composite membrane with PE microspheres layer can effectively close the pore structure at 110°C and stop the battery reaction. The thermal stability test shows that the composite membrane does not shrink at 210°C, the thermal shutdown temperature window is as high as 100°C, and the PE coating can significantly improve the high temperature thermal dimensional stability of the membrane. Thanks to the porous microstructure of PE microspheres and the good electrolyte affinity of the PVDF skin layer, the PE composite membrane has good electrolyte wetting and uptake capabilities. The battery assembled by the PE composite membrane has a capacity retention rate of 88.6% after 100 cycles at 0.5 C and has excellent C‐rate capability.

How inertial lift affects the dynamics of a microswimmer in Poiseuille flow

The transport of motile microorganisms is strongly influenced by fluid flows that are ubiquitous in biological environments. Here we demonstrate the impact of fluid inertia. We analyze the dynamics of a microswimmer in pressure-driven Poiseuille flow, where fluid inertia is small but non-negligible. Using perturbation theory and the reciprocal theorem, we show that in addition to the classical inertial lift of passive particles, the active nature generates a ‘swimming lift’, which we evaluate for neutral and pusher/puller-type swimmers. Accounting for fluid inertia engenders a rich spectrum of complex dynamics including bistable states, where tumbling coexists with stable centerline swimming or swinging. The dynamics is sensitive to the swimmer’s hydrodynamic signature and goes well beyond the findings at vanishing fluid inertia. Our work will have non-trivial implications on the transport and dispersion of active suspensions in microchannels.

METHODS OF UNCREASING OF THE WAX MODEL SURFACE PRIMARY WETTABILITY DURING LOST-WAX CASTING

Lost-wax casting is one of the most advanced ways to obtain geometrically complex castings of high quality. One of the main factors influenced on the casting properties is the quality of the ceramic mold face layer. A uniform deposition of the ceramic slurry can be achieved by condition of the wax surface is well wetted by the suspension dispersion medium. Since the surface of the wax model is hydrophobic and the dispersion medium of ceramic suspension is water, an increase of wettability may be achieved not only by SAS-wetting agent adding in suspension composition but also by activating of the model surface by chemical or physical methods. The paper presents the results of the different ways of chemical activation influence on the wettability of the wax model surface.

Sulfur Quantum Dots as Fillers in Gelatin/Agar-Based Functional Food Packaging Films

The present work is the first attempt to study the applicability of sulfur quantum dots (SQDs) as functional fillers for food packaging biopolymer films. SQDs were prepared via hydrothermal synthesis using sublimated sulfur powder. The SQDs were 8.7 nm in size and consisted of an elemental sulfur core stabilized by PEG-400 confirmed by TEM, FTIR, and XPS characterization. The SQDs exhibited a high surface charge of −13.9 mV, indicating good dispersion in aqueous suspensions. In addition, the SQDs showed high antioxidant and antimicrobial activities with almost negligible toxicity toward L929 cells even at prolonged exposure of 72 h. The addition of SQDs to the gelatin/agar blend films increased the UV-barrier property without compromising color and transparency. The composite film showed excellent antioxidant activity, a moderate bactericidal effect on Listeria monocytogenes, and an inhibitory effect on Escherichia coli. The SQDs are likely to be value-added, low-cost, safe, and multifunctional nanofillers for preparing functional films in active packaging applications.

Eco-friendly utilization of microplastics for preparing coal water slurry: rheological behavior and dispersion mechanism

Microplastics (MPs) are emergingly hazardous contaminants which ubiquitously exists in aquatic, terrestrial and atmospheric system, as well as in human system. Coal water slurry (CWS) is an important clean-coal-based liquid fuel with the characteristics of high-efficiency and low-pollution. This paper aims to implement the principles of clean production and prepare CWS by coblending coal particles and polyethylene terephthalate (PET) microplastics. It shows that the presence of PET particles significantly reduces the viscosity and increases the dispersion performance of CWS suspension. The apparent viscosity of CWS tends to decrease with the increase of PET content. Through the contact angle, surface morphology, and zeta potential analyses, particles with stronger hydrophobicity, more spherical shape and higher electronegativity, are more easily to form consistent and dispersed CWS suspensions. The extended DLVO theory demonstrates that the repulsion between solid particles becomes larger when PET particles are added to the slurry, which is beneficial to particle dispersion. In addition, the dispersant interfacial distribution differs between coal and PET particles, and significantly affect the rheological behavior and dispersion mechanism of CWS. This study proposes a potential approach to recycle the hazardous waste MPs and provides theoretical basis for enhancing CWS dispersion performance through coblending with PET microplastic particles.

Fabrication and characterization of metakaolin-based geopolymer composites reinforced with cellulose nanofibrils

In this work, nanocellulose/geopolymer composites were successfully fabricated through mixing an ultrasonically dispersed suspension of cellulose nanofibrils (CNF) with a metakaolin-based geopolymer (GP) binder. Fresh and hardened state properties of geopolymer composites containing 0.025, 0.05, 0.1, and 0.25 wt% CNF were investigated. The results showed that cellulose nanofibrils can be effectively used as a reinforcing phase of geopolymers, providing a significant increase in the tensile strength. With an increase in the content of cellulose nanofibrils, the consistency of the mixture changes dramatically, becoming viscous, impairing its workability and limiting the incorporation of larger CNF dosages. Therefore, in order to realize the full cellulose nanofibrils reinforcing potential, it is necessary to provide further optimization of the composition of CNF/GP composites, in particular through the addition of plasticizers and/or regulation of water-to-solids ratios.

Investigation of the flocculation and sedimentation of TiO2 nanoparticles in different alcoholic environments through turbidity measurements

Turbidimeters are low-cost devices, which are widely used for suspended sediment monitoring (SSM). The specific turbidity is typically relative to 1/d (d is the diameter of particles) regarding the suspensions with mono-sized sphere-shaped particles. As the production of the dispersed suspension of TiO2-NPs is vital for their photocatalysis applications, turbidity provides a test to measure the dispersion of TiO2-NPs. In the present paper, the performance of a self-manufactured turbidimeter device has been investigated using the suspensions of TiO2-NPs in different alcoholic media. The results showed that over time, the intensity of light passing through the upper part of the test tube containing TiO2-NPs suspension increased, suggesting the settlement of TiO2 nanoparticles. In the middle part of the test tube; however, an almost stable trend was observed, which was more evident in the case of isopropanol with higher viscosity. The results also illustrated that there was no relation between the concentration of suspension and the value of transmitted light for concentration below 0.08 g/l; however, for concentrations above that, the intensity of transmitted light decreased with the increase of suspension concentration.

Characterization of Materials Used as Face Coverings for Respiratory Protection.

Use of masks is a primary tool to prevent the spread of the novel COVID-19 virus resulting from unintentional close contact with infected individuals. However, detailed characterization of the chemical properties and physical structure of common mask materials is lacking in the current literature. In this study, a series of commercial masks and potential mask materials, including 3M Particulate Respirator 8210 N95, a material provided by Oak Ridge National Laboratory Carbon Fiber Technology Facility (ORNL/CFTF), and a Filti Face Mask Material, were characterized by a suite of techniques, including scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. Wetting properties of the mask materials were quantified by measurements of contact angle with a saliva substitute. Mask pass-through experiments were performed using a dispersed metal oxide nanoparticle suspension to model the SARS-CoV-2 virus, with quantification via spatially resolved X-ray fluorescence mapping. Notably, all mask materials tested provided a strong barrier against respiratory droplet breakthrough. The comparisons and characterizations provided in this study provide useful information when evaluating mask materials for respiratory protection.

Application of Vinyl ether Copolymers for Surface Modification of Carbon Black

In this work, the possibility of stabilizing aqueous dispersed systems of carbon with vinyl ether copolymers of various composition and structure was investigated. It was shown that the presence of hydrophobic fragments in the macromolecule chain plays a significant role and positively affects the results of stabilization of aqueous dispersions of carbon particles. It was shown that the composition and molecular architecture of the stabilizing copolymer strongly affects the stabilizing ability in studied systems. Studies have shown that the use of a polymeric stabilizer in combination with ultrasonic treatment of dispersed systems makes it possible to obtain stable, homogeneous, highly dispersed suspensions. At the same time, it was demonstrated that a strong increase in the time and intensity of ultrasonic treatment of the system does not lead to a significant improvement in the results

Tungsten Disulfide Inorganic Nanotubes Functionalized by PTFE for Friction Application

Inorganic nanotubes (INTs) and fullerene-like nanoparticles (NPs) of WS2/MoS2 penetrate and exfoliate at the contact interface and facilitate tribofilm formation. While the tribological properties are greatly improved by exfoliated NPs that shed easily, they may be diminished by agglomeration in oil. Therefore, surface functionalization is employed to improve dispersion in oil-based suspensions. Here, WS2 INTs were functionalized by polytetrafluoroethylene (PTFE) in a simple and cost-effective bath sonication method. WS2-INTs with two concentrations of added PTFE were characterized by scanning and transmission electron microscopy, micro-Raman spectroscopy, and thermogravimetric analysis. Superior distribution of WS2 was observed before and during friction experiments. Chemical analysis showed a significantly greater amount of PTFE-coated INTs on rubbed surfaces, in accordance with the improved friction and wear properties.

Rheophysical study of dispersed alumina suspensions

This paper studies the rheological behavior of aqueous suspensions of fine grained (d50 = 200 nm) alumina. Rheological measurements were performed on suspensions containing various amounts of solid and 0.26 wt% of ammonium polymethacrylate in order to ensure a good state of dispersion. Brownian motions, colloidal interactions and hydrodynamic interactions dictate the behavior. The viscosity is mainly influenced by the shear rate and by the solid volume fraction. A Maron and Pierce model was used to describe this last effect in the hydrodynamic regime. The maximum packing fraction was found to be 40 vol%. This value is related to the colloidal stability as described by the DLVO theory. In fact, the maximum packing fraction leads to a surface-to-surface separation distance of about 46 nm because of the repulsive potential. Finally, a dimensionless approach was achieved to quantitatively identify, on the rheogram, the different flow regimes associated to each dominant interaction type.

Synthesis and characterization of inclusion complexes of rosemary essential oil with various β-cyclodextrins and evaluation of their antibacterial activity against Staphylococcus aureus

The aim of the present study was the encapsulation of Rosmarinus officinalis essential oil (REO) in β-cyclοdextrin (β-CD) and two chemically modified β-CD matrices and the evaluation of the antibacterial activity of the prepared inclusion complexes against Staphylococcus aureus. The inclusion complexes possessed nanoscale size ranging from 395.7 ± 13.7 to 594.9 ± 18.8 nm, good size dispersion (0.366 ± 0.009 to 0.482 ± 0.043) and satisfactory stability in suspension (ζ-potential, −24.3 ± 4.2 to −31.5 ± 4.9 mV), while the inclusion efficiency ranged from 65% to 78%. The in vitro release profiles of the inclusion complexes revealed an initial burst effect, with the release kinetics being better fitted on the Higuchi model following quasi-Fickian diffusion. The antibacterial activity of the inclusion complexes of REO in β-CD, HP-β-CD and Me-β-CD against S. aureus was evaluated for 3 days and it was observed that both β-CD and HP-β-CD exhibited prolonged activity in comparison to the pure REO.

Green properties of dry-pressed alumina using a new synthesized copolymer able to act simultaneously as dispersant and binder with plastic character

Statistical copolymers containing both carboxylate and hydroxyl functions have been synthesized in order to promote the dispersion of alumina suspensions in addition to the binding of pressed green disc-shaped specimens. In aqueous suspensions, the carboxylate groups are responsible for maintaining a high adsorption of the copolymer onto the alumina surface particles, thus increasing surface charges promoting a high electrostatic stabilization. The hydroxyl functions, which are not preferentially adsorbed on the surface i) participate in the steric stability of the suspension and, ii) confer a high mechanical resistance to green powder compacts compared to specimens classically shaped with 3 wt% of commercial polyvinyl alcohol and 1 wt% polyethylene glycol. Indeed, tensile stress to rupture evaluated by diametral compression is always greater than 3.5 MPa. The transition temperature of synthesized copolymers ranges from -10 to 57 °C, makes it possible to confer a plastic character to the organic system and to reach a high relative green density (around 63%) after compaction under 190 MPa at room temperature. Moreover, the effect of various molecular weights (from 11000 to 47000) on properties of spray-dried granules and of pressed compacts has been studied. A narrow spray-dried granule size distribution of corresponds to an optimal content of added copolymer, which in turn results in an optimal density of compacted parts. Optimal density values of the compacted parts follow the same trend as the highest particle size distribution corresponding to the optimal added copolymer content. The optimal values of densities correspond to an added amount of 1, 1.5 and 2 wt% respectively of high, medium and low copolymer's molecular weight.

The synthesis of Ag3PO4 under graphene oxide and hydroxyapatite aqueous dispersion for enhanced photocatalytic activity

The development of Ag3PO4 photocatalyst for organic pollutant degradation is very challenging due to excellent activity under visible light exposure. The research aims to synthesize Ag3PO4 under graphene oxide (GO) and hydroxyapatite (HA) as a phosphate ion source for Rhodamin B degradation. The Ag3PO4/GO was prepared using the precipitation method with the starting material of graphene oxide aqueous dispersion, AgNO3, and hydroxyapatite suspension. The structure, absorption, morphology, and element composition of photocatalysts were studied using XRD, DRS, SEM, and EDX. Photocatalytic abilities of the samples were tested using RhB oxidation under blue light exposure. The results exhibited that GO improves the crystallinity andvisibleabsorption spectrum of Ag3PO4. Incorporating GO on Ag3PO4 decreases the ratio of O/Ag and O/P leading to a defect formation. The reaction mechanism on the surface of the photocatalyst was mainly run by holes and superoxide radical ions. The modification of Ag3PO4 using hydroxyapatite and GO improved photocatalytic activity.

Clinical Case of Fetal Lymphangioma

Lymphangioma is a benign lymphatic system tumor, often congenital, mainly affecting lymph nodes in various anatomic localizations. Postnatally mostly common lymphangioma manifestation occurs during the first year of life. Today it can be readily diagnosed prenatally. Diagnosis is based on non-invasive visualization, such as sonography and computed tomography. The objective: is to present clinical case of manifest fetal lymphangioma diagnosed during pregnancy. Fetal ultrasound (US) was performed at 28, 32, 34 weeks of gestation. As a result fetus was diagnosed with hypoechogenic mass in right axillary region, growing in dynamics gradually from 34×28 mm, 38×34 mm to 49×37 mm. Mass had clear even contours, hyperechogenic capsule with fine dispersed suspension content. Color doppler imaging showed avascular mass character. After delivery at 37–38 weeks of gestation (planned Cesarean section) at newborn examination we visualized asymmetric soft elastic consistency protrusion along right midclavicular and anterior axillary region. Described clinical case of fetal lymphangioma is a good illustration of dynamic prenatal and postnatal dynamic observation and its US interpretation.

RF induction heating and in-vitro study of citrate functionalized Zr-substituted Fe3O4 nanoparticles with human lung adenocarcinoma (A549) cell

We present a study on biocompatibility of citrate capped ZrxFe3-xO4 based magnetic ferrofluids with human lung adenocarcinoma (A549) cell, evaluated by Sulforhodamine B assay. It was found to be ~86% at a concentration of 1.5 mg/mL after 48 h. We approached single step and cost effective polyol methodology to get a well dispersed and homogeneous aqueous suspension of citric acid coated ZrxFe3-xO4, (0 ≤ x ≤ 0.3) MNPS. We used citric acid which anchored over the surface of freshly prepared nanoparticles to provide stability for longer duration . The X-ray and electron diffractions suggested the formation of single phasic magnetite particles of size 5–18 nm. The aggregation of MNPS was prevented by citric acid which was confirmed from Fourier-transform infrared spectroscopy spectra. The Zeta potential measurement inferred the well dispersion of nanoparticles at varying pH values (2−10). The Zr-substituted magnetite had relatively lower magnetization values than pure one. The optimum specific absorption rate (SAR) value at a field of 23 mT, 261 kHz was obtained to be 44 W/g for the sample x = 0.02 at a concentration of 10 mg/mL. In contrast, the intrinsic loss power (ILP) value was optimum (0.54 nHm2/kg) for Fe3O4 ferrofluid having a concentration of 5 mg/mL and at a field of 17 mT, 170 kHz. Nevertheless, the reported ferrofluids have displayed high heating capacity and suitable biocompatibility thus these could be used as promising materials for bioapplications including magnetic hyperthermia.