Volumetric Studies Research Articles

Subject-Level Segmentation Precision Weights for Volumetric Studies Involving Label Fusion.

In neuroimaging research, volumetric data contribute valuable information for understanding brain changes during both healthy aging and pathological processes. Extracting these measures from images requires segmenting the regions of interest (ROIs), and many popular methods accomplish this by fusing labels from multiple expert-segmented images called atlases. However, post-segmentation, current practices typically treat each subject's measurement equally without incorporating any information about variation in their segmentation precision. This naïve approach hinders comparing ROI volumes between different samples to identify associations between tissue volume and disease or phenotype. We propose a novel method that estimates the variance of the measured ROI volume for each subject due to the multi-atlas segmentation procedure. We demonstrate in real data that weighting by these estimates markedly improves the power to detect a mean difference in hippocampal volume between controls and subjects with mild cognitive impairment or Alzheimer's disease.

Volumetric studies for glycine in aqueous L-tartaric acid to find intermolecular interactions at different temperatures along with FTIR and thermal stability

Volumetric studies for glycine in aqueous L-tartaric acid to find intermolecular interactions at different temperatures along with FTIR and thermal stability

Highfield imaging of the subgenual anterior cingulate cortex in uni- and bipolar depression.

The subgenual Anterior Cingulate Cortex (sgACC), as a part of the Anterior Cingulate Cortex and the limbic system plays a crucial role in mood regulation. Previous structural and functional brain imaging studies of the sgACC have revealed alterations of Gray Matter (GM) volumes and Blood Oxygenation Level Dependent signals (BOLD) in patients with Major Depressive Disorder (MDD) and Bipolar Disorder (BD), suggesting potential biomarker traits for affective disorders. In this study we investigated the gray matter volume of the sgACC in 3 different patient groups: 40 MDD patients, of which 20 were medicated (MDDm) and 20 were unmedicated (MDDu), and 21 medicated BD patients, and compared them with 23 healthy volunteers. We examined GM volume alteration using high-resolution 7T Magnetic Resonance Imaging (MRI) which produced quantitative maps of the spin-lattice relaxation time (T1). T1 maps provide high contrast between gray and white matter, and at 7 Tesla voxels with submillimeter resolution can be acquired in a reasonable scan time. We developed a semi-automatic segmentation protocol based on refined landmarks derived from previous volumetric studies using quantitative T1 maps as raw input data for automatic tissue segmentation of GM, WM and CSF (cerebrospinal fluid) tissue. The sgACC ROI was then superimposed on these tissue probability maps and traced manually by two independent raters (F.B., M.M.) following our semi-automatic segmentation protocol. Interrater reliability was calculated on a subset of 10 brain scans for each hemisphere, showing an Intra-Class Correlation coefficient (ICC) r = 0.96 for left sgACC and r = 0.84 for right sgACC respectively. In summary, we have developed a reproducible and reliable semi-automatic segmentation protocol to measure gray matter volume in the sgACC. Based on previous findings from meta-analyses on morphometric studies of the sgACC, we hypothesized that patients with MDD would have lower gray matter sgACC volumes compared to healthy subjects. Post-hoc analysis revealed smaller subgenual volumes for the left hemisphere in both the medicated (MDDm) and non-medicated (MDDu) group versus healthy controls (p = .001, p = .008) respectively. For the right hemisphere, the (MDDu) and BD group exhibited significantly lower subgenual volumes than healthy controls (p < .001, p = .004) respectively. To our knowledge, this is the first morphometric MRI study using T1 maps obtained in high-resolution 7 Tesla MRI to compare MDD and BD patients with healthy controls.

Insights from volumetric, acoustic, conductance and spectroscopic studies to study the molecular interactions of drug Levocetirizine in aqueous and aqueous glucose solutions at varying temperatures

Levocetirizine, an antihistamine, has been analyzed in relation to temperature by volumetric, acoustic, and spectroscopic methods to investigate its interaction with glucose, the predominant carbohydrate. Density and ultrasonic velocity for LC (0–0.10 mol dm−3) at different temperature (298.15, 308.15 and 318.15 K) in water and in aqueous solution of glucose (0.05, 0.10 and 0.15 mol kg−1) have been recorded using Anton Paar DSA 5000 M. The apparent molar volume (Vϕ), limiting apparent molar volume (Vϕ0), apparent molar compressibility (Kϕ,S), limiting apparent molar compressibility (Kϕ,S0) were computed utilizing the experimental data. In addition, the transfer parameters of LC from water to aqueous glucose solutions were identified and elucidated using the co-sphere model. The transfer volumes have been utilized to estimate the interaction coefficients. Limiting apparent molar expansibility (ϕE0) and Hepler’s constant was obtained to throw light upon the structure-making or structure-breaking effect of solute. Multiple acoustical parameters like isentropic compressibility (KS), relaxation strength (r), intermolecular free length (Lf), specific acoustic impedance (Z), Wada’s constant (W), relative association (RA), Rao’s constant (Rm), molar volume (Vm), Van der Waals constant (b), and free volume (Vf) were determined to validate the thermodynamic results.

CORROSION BEHAVIOUR OF MAGNESIUM ALLOYS NZ30K AND NZ30K ALLOYED WITH SILVER IN THE MODEL SOLUTION OF THE OSTEOSYNTHESIS PROCESS

The corrosion behaviour of magnesium alloys NZ30K and NZ30K alloyed with 0.1 wt.% silver in Ringer's Locke solution has been studied, since their components are not toxic to the human body and do not cause clinical complications in the treatment of bone fractures, and silver has antibacterial properties inherent in antibiotics. It has been found that the Ecor potential of the silver-alloyed NZ30K sample was -1.57V during the first 100 seconds of testing, but then it intensively shifted to the positive side to -1.54V within 512 seconds at a rate of 0.051 mV/s, which decreased to 0.014 mV/s after the next 1000 seconds, and a stationary value of the potential Ecor on the sample has been recorded. The sample to uniform general corrosion has been subjected, and the improvement of its potential Ecor during its corrosion study was due to the most intense selective dissolution of magnesium, which has the most negative value of the standard potential among the alloy components, and the enrichment of its surface with Zn, Nd, Zr, Ag, which have a positive value of the standard potential. This trend contributed to a decrease in the rate of general corrosion and made it impossible to develop local corrosion. The NZ30K alloy alloyed with 0.1 wt.% silver is recommended for further potentiodynamic and volumetric corrosion studies to justify its selection as a structural material for the production of biodegradable implants in osteosynthesis.

Volumetric and ultrasonic studies of molecular interactions in binary mixtures of N,N-dimethylacetamide with some polyethylene glycols at temperatures from 293.15 to 323.15 K

The intermolecular interactions in N,N-dimethylacetamide (DMA) + polyethylene glycol (PEG) mixtures have been examined from the measurements of the densities, ρ and speeds of sound, u of DMA + PEG 200 or PEG 300 or PEG 400 or PEG 600 mixtures over the entire mole fraction range at temperatures, T = (293.15–323.15) K and atmospheric pressure. Various excess parameters, viz., excess molar volume, excess isentropic compressibility, excess intermolecular free length, excess speed of sound, excess molar isentropic compressibility and excess acoustic impedance were evaluated using measured data. These excess properties were correlated with the Redlich–Kister equation. In addition, the partial molar volume and compressibility; excess partial molar volume and compressibility of the components over the entire composition range; and partial molar volume and compressibility and excess partial molar volume and compressibility of the components at infinite dilution have also been calculated. These evaluated parameters have been interpreted by means of prevailing intermolecular interactions in these mixtures. The presence of strong intermolecular interactions among DMA and PEG molecules have been revealed from the evaluated parameters of these mixtures. The speeds of sound were predicted theoretically using scaled particle theory and compared with experimental values. FT-IR spectra of pure DMA, PEG 200 and their equimolar mixtures were also recorded and analysed for better understanding of prevailing intermolecular interaction.

Brain Magnetic Resonance Imaging in Wilson's Disease-Significance and Practical Aspects-A Narrative Review.

Wilson's disease (WD) is a genetic disorder of copper metabolism with pathological copper accumulation in many organs, resulting in clinical symptoms, mostly hepatic and neuropsychiatric. As copper accumulates in the brain during WD, and almost 50% of WD patients at diagnosis present with neurological symptoms, neuroimaging studies (especially brain magnetic resonance imaging (MRI)) are part of WD diagnosis. The classical sequences (T1, T2, and fluid-attenuated inversion recovery) were used to describe brain MRI; however, with the development of neuroradiology, several papers proposed the use of new MRI sequences and techniques like susceptibility-weighted images, T2*, diffusion MRI, tractography, volumetric assessment and post-processing brain MRI analysis of paramagnetic accumulation-quantitative susceptibility mapping. Based on these neuroradiological data in WD, currently, brain MRI semiquantitative scale and the pathognomonic neuroradiological brain MRI signs in WD were proposed. Further, the volumetric studies and brain iron accumulation MRI analysis suggested brain atrophy and iron accumulation as biomarkers of neurological WD disease severity. All these results highlight the significance of brain MRI examinations in WD. Due to the extreme progress of these studies, based on the available literature, the authors present the current state of knowledge about the significance, practical aspects, and future directions of brain MRI in WD.

Calorimetric and Volumetric Studies of Dislocations During Martensitic Transformations in Shape Memory TiNi Alloy

Based on the use of appropriate approaches, methods and results of the analysis of a number of topical problems of physical materials science, an in-depth analysis has been done of calorimetric and volumetric data for direct, reverse and deformation martensitic transformations in a nanostructured Ti49.3Ni50.7 shape memory alloy obtained by cold rolling with simultaneous action of pulsed high-density current. For the first time, by applying a new technique for processing calorimetric spectra (peaks), the staging and “kinetics” of changes in heat content, as well as thermal effects (enthalpies of individual stages) during direct and reverse martensitic transformations during cooling or heating of samples at a constant rate (3 × K/ min) in the range 170–370 K has been done. It is shown, by processing volumetric data, using theoretical values of the dislocation density and elements of the classical theory of dislocations, that in the Ti49.3Ni50.7 shape memory alloy subjected to cold deformation accompanied by the action of a pulsed current, a deformation martensitic transformation occurs, leading to a positive volume effect (∆V/V) ≈ 3 × 10–3), which can be largely due to dislocations. It is shown, by applying the theoretical values of the dislocation density and elements of the classical theory of dislocations, that the possible contributions of dislocations to the enthalpies of direct and reverse martensitic transformations (in the Ti49.3Ni50.7 alloy) can and should be significantly lower in absolute value, but opposite in sign to the observed enthalpies of direct and reverse martensitic transformation in a given alloy. It is shown that the physics of the processes under consideration is contained to a certain extent in scientific discoveries No. 239 “The phenomenon of thermoelastic equilibrium during phase transformations of the martensitic type – the Kurdyumov effect” and No. 339 “The phenomenon of the formation of non-equilibrium grain boundaries in polycrystals when they absorb lattice dislocations”.

Volumetric, acoustic and spectroscopic studies of molecular interactions in 1-butyl-3-methylimidazolium hexafluorophosphate + ethyl/propyl/n-butyl acetate binary mixtures at different temperatures

The purpose of this work is to investigate the influence of concentration, temperature and molecular size on intermolecular interactions in the mixtures of 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF6] with some alkyl acetates. The densities, ρ and speeds of sound, u for the 1-butyl-3-methylimidazolium hexafluorophosphate + ethyl acetate/propyl acetate/n-butyl acetate binary mixtures were measured over the entire range of composition at the temperatures, T = (293.15 – 323.15) K at 5 K intervals and at pressure, p = 101 kPa. The experimental data was used to calculate various excess properties, viz., excess molar volume, excess isentropic compressibility, excess intermolecular free length, excess speed of sound, excess molar isentropic compressibility and excess acoustic impedance. The partial molar volumes and compressibilities; and excess partial molar volumes and compressibilities of the components over the entire composition range and at infinite dilution have also been calculated. The results clearly indicated the presence of intermolecular interactions in these mixtures and the magnitude of [BMIM][PF6]-alkyl acetate interactions followed the order: ethyl acetate > propyl acetate > n-butyl acetate, i.e., the interactions were found dependent on the size of alkyl group of acetates. The speeds of sound were estimated theoretically using scaled particle theory and compared with experimental findings. FT-IR spectra of pure [BMIM][PF6], ethyl acetate, propyl acetate. n-butyl acetate and their equimolar mixtures were also recorded and analysed for better understanding of prevailing intermolecular interaction.

Brain neuroplasticity in multiple sclerosis patients in functional magnetic resonance imaging. Part 1: Comparison with healthy volunteers.

The aim of this study was to assess the activity of motor cortical areas and the resting brain activity in a group of multiple sclerosis (MS) patients compared to a group of healthy individuals according to task-based functional magnetic resonance imaging (t-fMRI), resting state functional MRI (rs-fMRI), and volumetric MRI studies. The study enrolled 28 MS patients and 20 healthy volunteers who underwent MRI examinations. Primary motor cortex (M1), premotor area (PMA), supplementary motor area, as well as resting state networks (RSN's) and volumes of selected brain structures were subjected to a detailed analysis. In MS patients, a motor task more often resulted in the activation of ipsilateral M1 cortex (observed in 39% of the studied group) as well as the PMA cortex (observed in 32% of MS patients). No differences in resting brain activity were found between the studied groups. Significant differences were observed in volumetric parameters of the total brain volume (healthy volunteers vs. MS patients, respectively): (1197 cm³ vs. 1150 cm³) and volumes of the grey matter (517 cm³ vs. 481 cm³), cerebellum (150 cm³ vs. 136 cm³), thalamus (16.3 cm³ vs. 12.6 cm³), putamen (8.9 cm³ vs. 7.7 cm³), and globus pallidus (4.57 cm³ vs. 3.57 cm³). In the MS patients, the motor task required significantly more frequent activation of the primary and secondary ipsilateral motor cortex compared to the group of healthy volunteers. The rs-fMRI study showed no differences in activity patterns within the RSN's. Differences in the total cerebral volume and the volume of the grey matter, cerebellum, thalamus, putamen, and globus pallidus were observed.

Perinatal influences on academic achievement and the developing brain: a scoping systematic review.

In this PRISMA-compliant systematic review, we identify and synthesize the findings of research in which neuroimaging and assessments of achievement have been used to examine the relationships among aspects of developmental programming, neurodevelopment, and achievement in reading and mathematics. Forty-seven studies met inclusion criteria. The majority examined the impact of prematurity (n = 32) and prenatal alcohol exposure (n = 13). Several prematurity studies reported a positive correlation between white-matter integrity of callosal fibers and executive functioning and/or achievement, and white matter properties were consistently associated with cognitive and academic performance in preterm and full-term children. Volumetric studies reported positive associations between academic and cognitive abilities and white and gray matter volume in regions such as the insula, putamen, and prefrontal lobes. Functional MRI studies demonstrated increased right-hemispheric language processing among preterm children. Altered activation of the frontoparietal network related to numerical abilities was also reported. Prenatal alcohol exposure studies reported alterations in white matter microstructure linked to deficits in cognitive functioning and academic achievement, including mathematics, reading, and vocabulary skills. Volumetric studies reported reductions in cerebral, cerebellar, and subcortical gray matter volumes associated with decreased scores on measures of executive functioning, attention, working memory, and academic performance. Functional MRI studies demonstrated broad, diffuse activation, reduced activation in canonical regions, and increased activation in non-canonical regions during numeric tasks. A preponderance of studies linked prematurity and prenatal alcohol exposure to altered neurodevelopmental processes and suboptimal academic achievement. Limitations and recommendations for future research are discussed. Identifier: DOI 10.17605/OSF.IO/ZAN67.

Volumetric, compressibility and viscometric studies on intermolecular interactions of NaC and NaDC with Emtricitabine and Lamivudine in aqueous medium at (298.15–313.15) K

Bile salts are bio-compatible natural amphiphiles having a significant role in pharmaceutical field as a solubility and permeability enhancer and possess a great biological importance for release and transport of nutrients due to dynamic micellization behavior. Hence, to unfold the interactional mystery of drug − bile salt system in the field of anti-retroviral drugs, we have aimed to investigate solute–solute and solute–solvent interactions of bile salts (NaC and NaDC) with anti-HIV drugs (Emtricitabine and Lamivudine) by using various techniques like volumetry, compressibility, and viscometry at temperature range (298.15 K-313.15 K) with a regular variation of 5 K. Experimental density and speed of sound data have been used to evaluate various physicochemical parameters such as apparent molar volume (φv), isentropic compressibility (κs), and apparent molar adiabatic compression (φκ). The CMC values of bile salts in pure water and aqueous solution of ECT and LMV at 298.15 K have also been evaluated from speed of sound data which corroborate well with our earlier conductivity study on these surfactants. The trends of φv, κs and φκ values for both NaC and NaDC with temperature and in presence of drugs (ECT/LMV) indicate strong solute–solvent interactions in studied system. The results are elucidated in terms of electrostatic and hydrophilic-hydrophobic interactions in bile salt-drug-water system which is confirmed by co-sphere overlap model. Comparatively, NaC offers strong interactions with both drugs due to more hydrophilic character than NaDC. Similarly, out of ECT and LMV, ECT shows strong solute–solvent interactions with both bile salts due to more hydrophilic character than LMV. Relative viscosity parameter (ηr) determined from viscosity measurements further supports above results. This interactional knowledge of bile salts with ECT and LMV would be beneficial to develop a better mechanism in pharmacy for enhancing efficacy and permeability of anti-HIV drugs by using bile salts as a drug delivery agent.

Thermodynamic and spectroscopic investigation of the molecular interactions among vitamin B5, calcium salt, and cyclodextrins in aqueous media

The pharmaceutical industry aims to enhance drug development processes by gaining a deeper understanding of the physiochemical properties of drug molecules. This study provides a comprehensive analysis of the volumetric and compressibility properties of the drug, calcium-D-pantothenate (CDP) in aqueous solutions of cyclodextrins (β-CD/HP-β-CD). By measuring the density and speed of sound, we have evaluated various parameters, including apparent molar volume, compressibility, and their corresponding infinite dilution parameters. In addition to this, positive transfer parameters such as ΔtrVs,φo and ΔtrKs,φo of solute provide insights into solute-co-solute and solute–solvent interactions. Also, Hepler’s constant offers valuable information on the structure-breaking characteristics of the studied drug in cyclodextrin medium. The decrease in molar conductance of the binary system after adding cyclodextrin supports our theoretical observation from volumetric and compressibility studies. Positive values of activation energy favor spontaneity and the solubilization process. Furthermore, the 1H NMR study demonstrates that the β-CD molecule interacts more strongly with CDP molecules as compared to HP-β-CD.

A volumetric, ultraacoustical study and computational study of molecular interactions in 4-aminoantipyrine-aqueous-β-cyclodextrin solutions

Present work reports experimental densities and corresponding apparent and standard partial molar volumes, ultrasonic velocities and isentropic, apparent and standard partial molar compressibilities of 4-Aminoantipyrine-aqueous-β-cyclodextrin (0.000 mol∙kg−1, 0.001 mol∙kg−1, 0.005 mol∙kg−1, 0.010 mol∙kg−1and 0.015 mol∙kg−1) solutions at different temperatures. Transfer properties like transfer volumes and compressions were calculated. The refractive indices of these systems were also measured. The computational properties such as solvation energy (ΔESol), relative stabilization energy (ΔERel), complexation energy (ΔEComp) and change in volume (ΔV) were computed using DFT. The results from volumetric and acoustical studies have been evaluated in terms of molecular interactions and their existence confirmed from experimental and computational studies. The values of transfer volumes and compressibilities indicate the hydrophilic-hydrophilic interactions between polar groups of 4-Aminoantipyrine and hydroxyl groups of β-cyclodextrin dominating over hydrophobic-hydrophobic interactions between the phenyl group of 4-Aminoantipyrine and hydrophobic interior of β-cyclodextrin.

Volumetric and acoustic studies of binary mixtures of n-butylamine with propanol at T = (298.15-318.15) K

ABSTRACT This study investigated the molecular interactions within mixtures of n-butylamine (NBA) and isomers of propanol. We conducted an exhaustive analysis of excess molar volume ( V m E ), deviation in ultrasonic speed ( Δ u ), and excess isentropic compressibility ( κ s E ) by utilising the measured data of density ( ρ ) and ultrasonic speed ( u ) at T = 298.15 K to 318.15 K under pressure at 0.1 MPa. This led to the derivation of secondary properties such as partial ( V ˉ i ), excess partial ( V ˉ iE ), and apparent molar volume ( V φi ). As the temperature rises, the V m E become more negative, while the Δu values more positive. The RK equation was employed to fit the excess properties data, with further exploration through additional theories. The findings presented here offer vital insights into amine – alcohol mixtures and their thermodynamic and acoustic properties, which are invaluable for optimising related chemical engineering and industrial processes.

Volumetric and Thermodynamic Studies on Urea–Water System

Volumetric and Thermodynamic Studies on Urea–Water System

Calorimetric and Volumetric Studies of Dislocations during Martensitic Transformations in TiNi Alloy with Shape Memory

Calorimetric and Volumetric Studies of Dislocations during Martensitic Transformations in TiNi Alloy with Shape Memory

Unraveling the Solvation Behavior of Levocetirizine Dihydrochloride: Insights from Volumetric, Acoustic, Viscometric, and Electronic Absorption Studies in Aqueous l-Proline and l-Valine Solutions

Unraveling the Solvation Behavior of Levocetirizine Dihydrochloride: Insights from Volumetric, Acoustic, Viscometric, and Electronic Absorption Studies in Aqueous <scp>l</scp>-Proline and <scp>l</scp>-Valine Solutions

PEGylated Deep Eutectic Solvent–Caffeine Interactions in Aqueous Solutions Evaluated by Volumetric and Spectroscopic Studies

PEGylated Deep Eutectic Solvent–Caffeine Interactions in Aqueous Solutions Evaluated by Volumetric and Spectroscopic Studies

Volumetric and acoustic studies of binary mixtures of DEC with isomeric chlorobenzene at various temperatures

ABSTRACT Densities, ρ, and speeds of sound, u, of binary liquid mixtures of diethyl carbonate with 1,2-dichlorobenzene, 1,3-dichlorobenzene and 1,2,4-trichlorobenzene have been measured over the entire range of composition at 303.15 K, 308.15 K, 313.15 K and 318.15 K and at atmospheric pressure. From the experimental data of the density and speed of sound, the excess properties such as excess molar volume, V m E , excess isentropic compressibility, κ s E , excess molar isentropic compressibility, K s , m E , excess speed of sound, u E , and excess isobaric thermal expansion, α p E , have been calculated. For better knowledge of the solute and solvent interaction, excess partial molar volumes, V ˉ m , 1 E and V ˉ m , 2 E , and excess partial molar volumes, V ˉ m , 1 ∘ E and V ˉ m , 2 ∘ E of the components at infinite dilution have been measured. All the excess parameter values have been fitted using the Redlich–Kister polynomial smoothing equation. The calculated excess values have been analysed in terms of molecular interactions and structural effects.