Ultrasonic Studies Research Articles

Spectrophotometric and thermal stability of agarose-based ultrasonic tissue-mimicking gel

Spectrophotometric measurements of a commonly used agarose-based ultrasonic tissue-mimicking gel are reported. In addition, spectral characteristics after heating to different temperatures provide thermostability information. Thermostability of agarose gels has not been previously reported, except in general terms. Gels were produced and cast into 2 mm thick spectrophotometric cuvettes. UV-Vis spectra were recorded after gels were heated to various temperatures. Spectral changes resulting from heating were noted and were largely unchanged with heating to temperatures ranging from 30 to 70 °C. Only with heating to 80 °C, which is near the melting point of the gel material, do spectra irreversibly change. We show that agarose-based tissue-mimicking gels are largely stable over temperatures relevant to most biomedical ultrasonic studies, including those examining hyperthermia or high-intensity focused ultrasound. Therefore, they likely provide a stable substrate in which to conduct ultrasonic heating studies. In addition, UV-Vis spectrophotometry of this optically opaque material has been demonstrated. Possible additives to this material that would enable the measurement of temperature fields through postexposure sectioning and slicing are subsequently discussed.

Intrapartum Ultrasonography for Detecting Fetal Macrosomia

Objective: To compare the accuracy of three ultrasound methods to estimate fetal weight within 48 hours before delivery, in order to recognize macrosomia, defined as birth weight greater than 4000 g.Methods: A prospective and ultrasonic study was performed on a sample of singleton pregnancies between 37 weeks and 41 weeks plus 6 days of gestation. Fetal weight was evaluated with Estimated Fetal Weight (EFW) formula, with the measurement of the Abdominal Circumference (AC) and with the assessment of the Abdominal Circumference corrected with the constant “c” (ACc).Results: 1030 patients with single pregnancy were included, 67.28% of them were primiparous, average Body Mass Index (BMI) at birth was 27.37 and macrosomia was found in 77 (8,08%) fetuses. EFW showed a sensitivity of 61.53%, a specificity of 90.72%, a positive predictive value (PPV) of 27.58% and negative predictive value (NPV) of 97.46%, to recognize birth weight of more than 4000 g. AC greater than 375 mm presented a sensitivity of 53.24%, a specificity of 93.21%, a PPV of 41.41% and a NPV of 95.67%, to detect macrosomic fetuses. ACc greater than 375 mm showed a sensitivity of 66.23%, a specificity of 88.65%, a PPV of 34.35% and a NPV of 96.68%, to predict macrosomia. The mean absolute error when the neonatal weight was greater than 4000 g, with EFW was 9,23%, with AC were 11,02% and with ACc was 9,32%.Conclusions: In this study was shown that either EFW, or AC-only, or ACc are useful tools to detect fetal macrosomia. The measurement of AC and Acc seem to be the easiest methods to learn and to be used every time. During the first stage of labor, ultrasound scan associated to clinic evaluation, provides further elements to physician, to allow a better management of delivery. The finding of a NPV greater than 95% with the three methods, leads to exclude macrosomia with a good approximation, even in case of clinic hypothesis.

Volumetric, ultrasonic and viscometric studies on L-lysine mono-hydrochloride in aqueous medium at different temperatures

Volumetric, ultrasonic and viscometric studies on L-lysine mono-hydrochloride in aqueous medium at different temperatures

Surfactant-free synthesis and experimental analysis of Mn-doped ZnO–glycerol nanofluids: an ultrasonic and thermal study

A simplistic and environment-friendly approach has been used to prepare surfactant-free Mn-doped ZnO–glycerol nanofluids using high power sonicator. Thermal conductivity of the prepared nanofluids has been measured as a function of temperature and concentration. Maximum thermal conductivity enhancement ~ 32% at 40 °C has been observed with very low nanoparticles loading (2.0 vol% of Mn-doped ZnO-nanoparticles) which is significantly larger than the presently synthesized ZnO–glycerol nanofluids, and that of reported earlier on ZnO-ethylene glycol, and other glycerol-based nanofluids. Our present investigation shows that the thermal conductivity of nanofluids can be increased up to a significant level by changing other physical properties of incorporated nanoparticles than increasing concentration of nanoparticles to a large extent. Various physical phenomena including Brownian motion induced convection effect in conjunction with ballistic diffusion have been proposed for anomalous thermal conductivity enhancement. This may be valuable for various cooling applications and may open avenues for further exploration of efficient heat management with the help of nanosized doped metal oxide suspensions.

SPLENIC SIZE RELATION TO THE PORTAL VEIN DOPPLER ANALYSIS IN SUDANESE LIVER TRANSPLANTS

The purpose of this study was to identify the specific Doppler criteria for the portal vein as well as the spleen length or volume in liver transplants. A relative study was done after performing venous Doppler sonographic studies in 45 liver transplant cases (4 whole liver, 41 lobar) with no known vascular complications. The ultrasonic Doppler study were targeted to the portal vein flow direction, flow velocity in Doppler level and the caliber in gray scale level. Average gray scale and color flow mapping appearances as well as normal monophasic wave character was found. The following Doppler parameters were evaluated: for the portal veins, venous pulsatility index. There were no cases of portal vein obstruction found in our sample (neither stenosis, nor occlusion). Mean portal vein velocity was (less than 55 cm /s), the splenic length was (13.7±1.5). The relation between the portal venous index, and the splenic length was built. Both are useful parameters for diagnosing liver transplants complications.

Ultrasonic Studies on the Nature of Molecular Interaction of Synthesized Mannich Bases in DMSO at Different Temperatures

This work deals with the ultrasonic studies of the Mannich bases (morpholin-4-yl)(pyridin-3- yl)methyl]hydrazine carboxamide (MPH) and (morpholino)(thiophen-2-yl)methyl)nicotine hydrazide (MTN) by the measurements of parameters such as ultrasonic velocity (U), density (ρ), viscosity (η), adiabatic compressibility (κ), intermolecular free length (Lf), molar volume (Vm), relaxation time (τ), specific acoustic impedance (Z), lenard jones potential (LJP), internal pressure (πi), free volume (Vf) and molecular cohesive energy (MCE), available volume (Va), Gibbs free energy (ΔG) and absorption coefficient (α/f2). These results are inferred that the strong interaction exists between the solvent (DMSO) and solute (MPH and MTN).

Effects of the trunk position on muscle stiffness that reflects elongation of the lumbar erector spinae and multifidus muscles: an ultrasonic shear wave elastography study.

The present study aimed to clarify the effects of the trunk position on muscle stiffness that reflects elongation of the lumbar erector spinae and lumbar multifidus muscles using ultrasonic shear wave elastography (SWE). The study included ten healthy men. The shear elastic modulus of the left lumbar erector spinae and lumbar multifidus muscles were evaluated using ultrasonic SWE. Measurement postures for the left lumbar erector spinae muscle were (1) prone position (Rest), (2) sitting position with the trunk flexed (Flexion), (3) the Flexion position adding right trunk lateral flexion (Flexion-Lateral Flexion), and (4) the Flexion position adding right trunk rotation (Flexion-Rotation 1). The left lumbar multifidus muscle were measured in positions (1)-(3), and (5) the Flexion position adding left trunk rotation (Flexion-Rotation 2). The shear elastic modulus of the lumbar erector spinae muscle in the Flexion-Lateral Flexion position was significantly higher than that in the Rest, Flexion, or Flexion-Rotation 1 positions. Shear elastic modulus of the lumbar multifidus muscle was similar in the Flexion, Flexion-Lateral Flexion, and Flexion-Rotation 2 positions, but significantly lower in the Rest position. The results of the present study suggest that the lumbar erector spinae muscle is stretched effectively in the position adding trunk contralateral lateral flexion to flexion. The results also indicate that the lumbar multifidus muscle, which does not appear to be affected by adding trunk contralateral lateral flexion or ipsilateral rotation to flexion, is stretched effectively in the trunk flexion position.

Ultrasonic study of Laves phase compounds ScOs2 and YOs2

The paper presents computation of second- and third-order elastic constants of Laves phase compounds ScOs2 and YOs2 at room temperature using Lennard-Jones potential model. The thermal relaxation time, ultrasonic velocity, ultrasonic attenuation and other related thermo-physical parameters (Debye average velocity, Debye temperature, thermal conductivity, specific heat and thermal energy density) are also calculated using second- and third-order elastic constants. The obtained elastic and ultrasonic properties of chosen compounds have been likened with the properties of other hexagonal structured materials for complete analysis and characterization.

Synthesis, characterization of CuO nanostrips and ultrasonic study of CuO-transformer oil nanofluids

The CuO nanostrips are synthesized by simple low cost wet chemical route. Synthesized nanostrips are characterized by energy dispersive analysis of x-rays for chemical composition. The crystal structure of the CuO nanostrips is determined by x-ray diffraction. The CuO nanostrips posses monoclinic structure having lattice parameters as; a = 4.68, b = 3.42, c = 5.13, α = 90°, β = 99.54° and γ = 90°. The high-resolution transmission electron microscopy and scanning electron microscopy showed synthesized CuO has strip like morphology. The synthesized CuO nanostrips are dispersed in two transformer oils, one of make year 1997 and another of make year 2017. Four different CuO nanostrips concentrations (0.01, 0.02, 0.03, 0.04 vol%) are dispersed in the two transformer oils. The CuO-transformer oils mixing are done by ultrasonication. The stability of the prepared transformer nanofluids is confirmed by UV–vis spectroscopy and zeta potential method. The prepared transformer nanofluids are studied by ultrasonic interferometer. The ultrasonic study of the transformer nanofluids are done at high temperatures of 303 K, 313 K, 323 K, 333 K and 343 K. The obtained results are discussed in this paper.

Ultrasonic Studies and Acoustic Parameters of Complexes Containing Copper Surfactants with 2-Amino-6-Methyl Benzo-thiazole

Background: Ultrasonic speed and density parameters have been measured in binary and ternary systems containing complexes of copper surfactants (caprylate, caprate, and laurate) with 2-amino-6-methyl benzothiazolein 80 % and 40% benzene-methanol mixture at constant temperature using thermostatic water bath. Objective: From these values, the specific acoustic impedance Z, adiabatic compressibility β, intermolecular free length Lf, apparent molar compressibility φk, have been calculated. These parameters were used to know and compare the CMC value of the system observed by other physical parameters like apparent molar volume, viscosity, surface tension, etc. Method: Different plots were plotted and it has been observed that the synthesized molecule is acting as surfactant at particular concentrations CMC its behavior deviates. Result: The results have been explained on the basis of intermolecular interactions and indicate that there is sufficient solute–solvent interaction due to which micellar alignment is considerably affected. The decrease in adiabatic compressibility β and intermolecular free length Lf of the copper surfactant complex solution with increasing concentration of copper surfactant complex in 80% and 40% benzene−methanol has been observed which suggest that the non-polar long chains or lypophilic segment of the molecule in the solution are enveloped by a layer of solvent molecules bound and oriented towards lypophilic end. Conclusion: The orientation of the solvent molecules around the solutes may be due to the influence of electrostatic fields of solutes and results in the increase in the internal pressure and in lowering the compressibility of the solution i.e. the solution becomes harder to compress. Keywords: Copper, surfactants, ultrasonic, 2-amino-6-methyl benzothiazole, solute, solvent.

Structural effect on the strength of non-covalent interactions in binary mixtures of benzyl amine and certain ethers through ultrasonic, FT-IR spectral and DFT studies at 303.15 K

Ultrasonic velocities (u), densities (ρ) and viscosities (η) of four binary liquid mixtures, containing benzyl amine (BA) as common component and four structurally different ethers (tetrahydrofuran (THF), 1,4 dioxane (DIOX), anisole (ANI) and diphenyl ether (DPE)) as varying components, were measured over the entire mole fraction range at 303.15 K and at experimental pressure of 101 kPa. The experimental data were used to compute several acoustical and excess thermodynamic parameters. The computed excess thermo-acoustic properties for each binary mixture are fitted to Redlich–Kister type polynomial equation. The computed binary co-efficients and standard deviations between the experimental and theoretical values established the existence of specific interactions in the complexes of four systems. The acoustical and excess thermo acoustic parameters were analysed in light of various types of intermolecular interactions and their structural dependence. The influence of structures of ethers on the non-covalent molecular interactions has been attempted through Density Functional Theory (DFT) calculation. The optimized structures of the monomers (BA, THF DIOX, ANI, and DPE), their self associated dimers (BA-BA, THF-THF, DIOX-DIOX, ANI-ANI and DPE-DPE) and their complexes with BA confirm the presence of hydrogen bonded interactions in all the four systems. In addition to the classical hydrogen bonding, CH⋯π interactions have also been identified in the binary systems which influenced the interaction energies of the complexes. The presence of non-covalent interactions among the solute species is supported by FTIR spectra of pure compounds and binary mixtures. The shift in the frequencies of the functional groups of amine and ethers has confirmed the observations made through ultrasonic and DFT studies.

Ultrasonic and Thermodynamic Studies in Ternary Liquid Systeam of Choline Chloride Urea+ L-Glutamine + Water at 298.15 And 308.15k

Ultrasonic and Thermodynamic Studies in Ternary Liquid Systeam of Choline Chloride Urea+ L-Glutamine + Water at 298.15 And 308.15k

DEVELOPMENT OF OBLITERATION IN THE GREAT SAPHENOUS VEIN AFTER INFLUENCE OF HIGH-FREQUENCY ENDOVENOUS WELDING BY DATA OF MORPHOLOGICAL AND ULTRASONIC STUDIES

Acute ascending thrombophlebitis (AAT) of the great saphenous vein (GSV) is one of the problems in modern surgery. Study of morphological and ultrasonic changes in a thrombosed vein following the influence of high-frequency endovenous electrical welding and assessment of the efficacy of application of this method to treatment of acute ascending thrombophlebitis. During the period of 2016-2018, surgery departments of Kyiv City Hospital No. 8 provided surgical treatment for 52 male and female patients with AAT of the GSV, who underwent high-frequency endovenous electrical welding (EVEW) with help of an EK300M Svarmed apparatus. The patients’ age ranged from 19 to 78 years (their mean age was 51±2.63 years). According to the international CEAP (сlinical-etiological-anatomical-pathophysiological) classification, C2 was revealed in 4 cases, C3 in 19, C4 in 13, C5 in 9 and C6 in 7. Sections, prepared in compliance with standard methods, were morphologically examined. Photo archiving was made with use of a ZEISS light optical microscope (Germany) and «Axio Imager. A2» data processing system. Duplex ultrasonography (DUS) was performed with help of a TOSHIBA Nemio XG (Japan) device, equipped with a convex transducer having the working frequency of 3.5-5 MC and a linear transducer at a range of 7.5-12 MC. Ultrasonic studies were carried out 2-7 days after the operation. Remote results were assessed after 3, 6 and 12 months. Morphological examinations of vein preparations after EVEW with standard haematoxylin-eosin staining revealed homogenization of thrombotic masses in the venous lumen and a close relationship of the veins with the treated vascular wall; in the majority of examined cases, thrombotic masses totally obliterated the venous lumen. All the layers of the venous wall – internal, middle and external – coalesced into a single homogenous complex. Specific staining on elastic fibers revealed their total destruction in the internal and middle coats, thinning and fragmentation of elastic fibers in the adventitia. Total occlusion of the GSV was observed sonographically in 49 of 52 cases (94.24%) on days 2-7 after the influence of EVEW. Within 3-6 months, 3 cases (5.76%) developed some partial recanalization. During 9-12 months, colour mapping revealed preservation of some partial and haemodynamically insignificant recanalization in 2 cases (3.84%). One case (1.92%) developed the complete and haemodynamically significant recanalization of the whole welded segment of GSV. Analysis of ultrasonic studies showed that despite the total destruction of the whole venous wall during the first days after the influence of EVEW there were areas of parietal blood flow in 5.76% of cases. During a remote period of follow-up from 3 to 6 months the above changes could develop partial and haemodynamically insignificant recanalization in 3.84% of cases. Within the period of follow-up from 9 to 12 months those areas of blood flow could lead to the complete and haemodynamically significant recanalization of the welded GSV in 1.92% of cases. High-frequency EVEW of the thrombosed GSV in AAT caused the total destruction of thrombotic masses and all layers of the venous wall and made it possible to achieve the total obliteration of the welded vein in 94.24 % of cases.

Adaptive possibilities of the cardiovascular system in adolescents with non-inflammatory diseases of the myocardium, taking into account the functioning of the right ventricle of the heart

Adaptation of the cardiovascular system to physical activity implies the development of functional or structural changes that should ensure the most efficient and economical use of energy during muscular contraction. The most studied data reactions in individuals engaged in various sports. The aim of our study was to study the functional changes of the heart, taking into account the functioning of the right and left ventricles of the heart and the adaptive capacity of the cardiovascular system in children with non-inflammatory diseases of the myocardium. Were examined 62 patients with non-inflammatory myocardial diseases, whose mean age was 14.56 ± 0.24 years. The control group consisted of 41 practically healthy peers. The functional state of the myocardium was assessed according to the results of the ultrasonic Doppler study of the heart in the “M” and “B” - modes, as well as in the mode of constant-wave and color scanning with a convex sensor using the standard method. To study tolerance to the minimum physical activity and its influence on the state of the cardiovascular system in children, a six-minute walk test was conducted. To assess the functional intensity of the cardiovascular system before and after the six-minute walk test, the following vegetative indices were calculated: an endurance coefficient according to the formula A. Quaasa and a double product. The vegetative Kerdo index and adaptation potential were calculated at rest. As a result of the study, it was found that in children with myocardial pathology, stress is observed in the adaptation mechanisms of the cardiovascular system, accompanied by a weakening of its functional capabilities and an increase in the work of the cardiac muscle at rest. This happens against the background of a decrease in the functioning of the left ventricle and an increase in the functioning of the right ventricle of the heart. These changes are accompanied by activation of the parasympathetic division of the autonomic nervous system in patients in all the studied groups, which indicates a more economical mode of functioning of the body systems.

Uterine artery Doppler indices may predict significant causes of perimenopausal bleeding

Objective The aim was to assess whether uterine artery Doppler indices can predict significant causes of uterine bleeding in patients with perimenopausal bleeding or not. Background Treatment of abnormal uterine bleeding needs easy diagnostic procedure, for determining the etiological factor of disease. The abnormal uterine bleeding is more common in the perimenopausal than in the postmenopausal women, and it is a sign of endometrial proliferative or hyperplastic changes. Patients and methods This prospective observational study was conducted on 106 women with perimenopausal bleeding [who were subdivided into two groups, one with nonsignificant causes (52 patients) and the other with significant causes (54 patients)] and 50 healthy controls, with transvaginal ultrasonic color Doppler study performed before endometrial sampling with pipelle in those with perimenopausal bleeding. Test characteristics of uterine artery pulsatility index and resistance index for prediction of significant causes of bleeding were the main outcome measures. Results Uterine artery pulsatility index at cutoff value of 1.82 with area under the curve of 0.834, sensitivity of 70.8%, specificity of 92%, positive predictive value of 94.9%, negative predictive value of 69.9%, and accuracy of 78%, whereas uterine artery resistance index at cutoff value of 0.575 with area under the curve of. 998, sensitivity of 96.2%, specificity of 100%, positive predictive value of 100%, negative predictive value of 92.6%, and accuracy of 97% were predictive of significant causes of perimenopausal bleeding. Conclusion Uterine artery Doppler is a simple, readily available and noninvasive tool that could be beneficial in conjunction with endometrial sampling to detect significant causes of perimenopausal bleeding.

Study of Acoustical and Thermodynamical Properties of Aqueous Ammonium Dihydrogen Orthophosphate

Ultrasonic is an effective tool for studying the nature and strength of molecular interactions of binary mixtures. In this present work, molecular interactions of Ammonium dihydrogen orthophosphate (ADP)electrolyte were studied using Ultrasonic method. The sound velocity is one of those physical properties that helps in understanding the nature of liquid state. Ultrasound velocity, density and viscosity of ammonium dihydrogen orthophosphate electrolyte were measured at 303 K, 308 K, 313 K,318 K and 323 K. The data obtained during the study is used for determining the various acoustical parameters like acoustic impedance, adiabatic compressibility, Rao’s constant, Wada’s constant, molar and molal salvation number, molar and molal volume, molar and molal solvated volume. Thermodynamical parameters such as internal pressure, free volume and relaxation time are also calculated. Thermodynamic properties of liquid mixtures have been extensively used to study the departure of a real liquid mixture behavior from ideality. The ultrasonic study of liquids is of immense important in understanding the biological activity of drug molecules and the activation energy of the metabolic process basically depend on the type and strength of the intermolecular interactions. Ammonium dihydrogen phosphate (ADP), also known asmono ammonium phosphate (MAP),NH4H2PO4 is often used in the blending of dry agriculturalfertilizers, fire retardant for wood, paper, fabric, dispersant for fiber processing and dyeing industry, glaze for enamel, cooperating agent for fire retardant coating, decontamination agent for match stalk and candle core.

Ultrasonic study of 1-propanol glasses with various thermobaric histories during the glass–liquid transition

Ultrasonic method has been used for experimental investigation of primary alcohol 1-propanol, which can be easily glassified at low temperatures. Two types of glasses with different thermobaric histories were obtained by different paths on the T–P diagram and were comparatively studied at isobaric heating during glass–liquid transition. At low temperatures, the elastic properties of glasses are different by tens of percent, but with increasing temperature the difference decreased and totally disappeared in the liquid phase.

SONOGRAPHIC EVALUATION OF OUTFLOW VEINS IN SUDANESE LIVER TRANSPLANTS

The purpose of this study was to identify the specific Doppler criteria for the outflow vein (hepatic veins and inferior vena cava) obstruction in liver transplants. A case control study was done after performing venous Doppler sonographic studies in 300 normal (control) and 45 liver transplant cases (4 whole liver, 41 lobar) with no vascular obstruction. The ultrasonic Doppler study were classified as normal, occluded, or stenosed on the basis of gray scale and color flow mapping appearances as well as elevated or absent waves. The following Doppler parameters were evaluated: the outflow veins on color Doppler interrogation, venous pulsatility index on spectral trace. Receiver operating characteristic curves were constructed. There were no cases of outflow vein obstruction found in our sample (neither stenosis, nor occlusion). Mean venous pulsatility index for normal outflow veins was 0.75 and is found ranging between (0.55-0.75). A venous pulsatility index of < 0.45 is specific for stenosis (5). The venous pulsatility index is a useful parameter for diagnosing venous stenosis in liver transplants.

The role of water soluble polymers in the phase separation of aqueous cholinium phenylalaninate solution as a green and biocompatible ionic liquid

The understanding of molecular-level mechanisms for the phase separation in polymer-based ABSs and the role of polymer structure are essential in the selection of a suitable ABS in applications such as bioseparation. For this purpose, in this work, a systematic investigation of ternary aqueous solutions containing [Ch][L-Phe] ionic liquid as a green new entrainer and different water soluble polymers (PEG400, PPG400, PEGDME250) was made by the volumetric, ultrasonic, and viscometric studies at different temperatures. These investigations indicate that PEGDME250 and PPG400 are able to form ABSs with ionic liquid; but phase separation cannot be occurred with PEG. This is indeed what we observed experimentally by studying phase diagrams. Unlike PEG the interaction between PEGDME or PPG with the ionic liquid are unfavorable leading to phase separation. Finally, the favorable partitioning of BSA in the ABS containing PPG compared with PEGDME was discussed on the basis of hydrogen bonding capability of the these polymers.

Ultrasonic Studies on Molecular Interactions of N-Phthaloylglycine in Protic and Aprotic Solvents at 303–318 K

Ultrasonic studies of (1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)acetic acid (N-phthaloylglycine) in polar and non polar solvent of various concentrations and temperatures 303–318 K are carried out. Ethyl alcohol and DMSO selected as polar and non-polar solvents respectively. Density and ultrasonic velocity measured. Different thermo-acoustical parameters viz. adiabatic compressibility, intermolecular free length, acoustic impedance, surface tension, Rao’s constant, molar volume, wada’s constant calculated with the help of these data using standard formulae. These data are used in understanding the molecular interactions in mixtures.