Present Results Research Articles

Tuning the electronic and vibrational properties of Sn[formula omitted]P[formula omitted]S[formula omitted]: Pressure induced metallization and superconductivity

The influence of external pressure on the properties of Sn2P2S6 has been systematically studied using density-functional theory calculations. It has been found that the ambient-pressure polymorph (space group P21/c) is most stable up to 100 GPa than the other two polymorphs reported in the literature. We have also found that the electronic band gap closes under compression, being metallization achieved at 35 GPa. In addition, electron–phonon coupling calculations show that the studied material is a superconductor at pressures of 35 GPa and higher. The critical temperature increases under compression. We will also present results on phonon-dispersion calculations, showing that Sn2P2S6 becomes dynamically unstable near 60 GPa. Finally results on the linear and volumetric compressibility are reported showing that Sn2P2S6 is highly compressible with a bulk modulus of 34(1) GPa.

In-plane and out-of-plane vibration analysis of laminated composite frames with warping effects

This paper addresses the free vibration analysis of a general planar frame structure, consisting of an assembly of laminated composite beam members. A mathematical model is established for the beams by introducing a novel displacement field, which encompasses the influence of shear deformation, rotary inertia, material coupling, warping phenomenon, as well as in-plane and out-of-plane deformations. By incorporating these various factors, a comprehensive representation of the beam's behavior is achieved. The continuity equations for displacements and rotations of two adjacent members are formulated to derive the equations for the entire frame structure. The assembled equations are solved using the Finite Element Method (FEM). The numerical results obtained are compared with existing results in the literature and new results from 3D models in ANSYS. The present results for torsional modes are closer to the ANSYS results than the results of previous studies. An extensive analysis is performed to investigate the impact of various parameters, including stacking sequence, frame angle, relative frame length, and anisotropy ratios on the system response.

The filling factor of the sEMG signal at low contraction forces in the quadriceps muscles is influenced by the thickness of the subcutaneous layer.

Introduction: It has been shown that, for male subjects, the sEMG activity at low contraction forces is normally "pulsatile", i.e., formed by a few large-amplitude MUPs, coming from the most superficial motor units. The subcutaneous layer thickness, known to be greater in females than males, influences the electrode detection volume. Here, we investigated the influence of the subcutaneous layer thickness on the type of sEMG activity (pulsatile vs. continuous) at low contraction forces. Methods: Voluntary surface EMG signals were recorded from the quadriceps muscles of healthy males and females as force was gradually increased from 0% to 40% MVC. The sEMG filling process was examined by measuring the EMG filling factor, computed from the non-central moments of the rectified sEMG signal. Results: 1) The sEMG activity at low contraction forces was "continuous" in the VL, VM and RF of females, whereas this sEMG activity was "pulsatile" in the VL and VM of males. 2) The filling factor at low contraction forces was lower in males than females for the VL (p = 0.003) and VM (p = 0.002), but not for the RF (p = 0.54). 3) The subcutaneous layer was significantly thicker in females than males for the VL (p = 0.001), VM (p = 0.001), and RF (p = 0.003). 4) A significant correlation was found in the vastus muscles between the subcutaneous layer thickness and the filling factor (p < 0.05). Discussion: The present results indicate that the sEMG activity at low contraction forces in the female quadriceps muscles is "continuous" due to the thick subcutaneous layer of these muscles, which impedes an accurate assessment of the sEMG filling process.

Analysis of MHD tangent hyperbolic hybrid nanofluid flow with different base fluids over a porous stretched sheet

This study investigates the flow of a two-dimensional magnetohydrodynamic(MHD) tangential hyperbolic hybrid nano fluid flow towards a porous stretched sheet with an inclined magnetic field under velocity and thermal slip conditions. Two distinct base fluids, (i) water and (ii) a mixture of ethylene glycol() and water are employed as base liquids with Copper() and aluminium oxide() nanoparticles, to generate two different hybrid nanofluids as and . Scaling group transformations with a homotopy algorithm is used to study the effects of distinct physical parameters like the Weissenberg number, an inclined magnetic field, thermal radiation, velocity, and thermal slip conditions with a heat generation/absorption parameter and a permeable parameter on the velocity and temperature distributions. The outcomes of hybrid nano fluid are compared with hybrid nano fluid in significant critical physical circumstances using graphs and tables. It is observed that the parameters and , , and λ increase the fluid temperature and decelerate the motion of fluid. The obtained results are validated by comparing them with the existing literature and found that the present results are consistent with the given data. Additionally, it is also noticed that the hybrid nanofluid has a higher heat transmission rate as compared to hybrid nanofluid. Finally, the impact of nano particle volume fractions of copper and aluminium oxide on the velocity and temperature profiles is discussed to study their efficiency.

Human organotypic brain slice cultures: a detailed and improved protocol for preparation and long-term maintenance

The investigation of the human brain at cellular and microcircuit level remains challenging due to the fragile viability of neuronal tissue, inter- and intra-variability of the samples and limited availability of human brain material. Especially brain slices have proven to be an excellent source to investigate brain physiology and disease at cellular and small network level, overcoming the temporal limits of acute slices. Here we provide a revised, detailed protocol of the production and in-depth knowledge on long-term culturing of such human organotypic brain slice cultures for research purposes. We highlight the critical pitfalls of the culturing process of the human brain tissue and present exemplary results on viral expression, single-cell Patch-Clamp recordings, as well as multi-electrode array recordings as readouts for culture viability, enabling the use of organotypic brain slice cultures of these valuable tissue samples for basic neuroscience and disease modeling (Fig. 1).

Ignition and combustion of synthetic nickel mattes in simulated flash smelting conditions

The ignition and oxidation behavior of synthesized sulfur-lean nickel mattes was investigated using a laminar flow furnace simulating the conditions in the flash smelting reaction shaft to explore the ignition and oxidation processes of sulfur-lean electric furnace mattes obtained from slag cleaning. The experiments were conducted at 800–1100 °C with 40–85 vol% O2 in the reaction gas. Scanning electron microscopy equipped with energy-dispersive X-ray spectrometry was used to analyze the surface morphology and mineralogical compositions of the samples. Chemical analysis was employed to determine the sulfur remaining in the samples. The ignition temperature of the sulfur-lean nickel mattes was found to be below 800 °C. The highest sulfur removal from mattes was achieved under the most oxidizing conditions. The oxidation of the metallized nickel mattes started with preferential oxidation of iron and sulfur, forming sulfur dioxide and a porous iron oxide-rich rim. Particles were observed to melt completely and even to fragment due to fast combustion reactions and the formation of sulfur dioxide inside. The present results provide valuable insights into the mechanism of sulfur-lean nickel matte smelting in flash smelting furnaces.

Cross-Cultural Adult ADHD Assessment in 42 Countries Using the Adult ADHD Self-Report Scale Screener

Objective: We analyzed adult ADHD symptoms in a cross-cultural context, including investigating the occurrence and potential correlates of adult ADHD and psychometric examination of the Adult ADHD Self-Report Scale (ASRS) Screener. Method: Our analysis is based on a large-scale research project involving 42 countries (International Sex Survey, N=72,627, 57% women, Mage=32.84; SDage=12.57). Results: The ASRS Screener demonstrated good reliability and validity, along with partial invariance across different languages, countries, and genders. The occurrence of being at risk for adult ADHD was relatively high (21.4% for women, 18.1% for men). The highest scores were obtained in the US, Canada, and other English-speaking Western countries, with significantly lower scores among East Asian and non-English-speaking European countries. Moreover, ADHD symptom severity and occurrence were especially high among gender-diverse individuals. Significant associations between adult ADHD symptoms and age, mental and sexual health, and socioeconomic status were observed. Conclusions: Present results show significant cross-cultural variability in adult ADHD occurrence as well as highlight important factors related to adult ADHD. Moreover, the importance of further research on adult ADHD in previously understudied populations (non-Western countries) and minority groups (gender-diverse individuals) is stressed. Lastly, the present analysis is consistent with previous evidence showing low specificity of adult ADHD screening instruments and contributes to the current discussion on accurate adult ADHD screening and diagnosis.

Effect of the partial blockage in the exit of the mixing channel on thermo - Hydraulic performance of the multi – Pass jet plate solar air heater

The present experimental work deals with the effect of partial blockage in the exit of the mixing channel on thermo-hydraulic performance of multi-pass jet plate solar air heater. This investigation is performed at IIT(ISM) Dhanbad campus (India) to obtain the results in terms of outlet temperature, collector efficiency, Temperature rise parameter (TRP), thermo - hydraulic performance parameter (THPP) and Nusselt number for double–pass cross and non–cross flow inline holes Jet Plate Solar Air Heater (JPSAH). Results for different ranges of operating and geometrical parameters such as, mass flow rate = 0.10–0.14 kg/s, Reynolds number, Re = 4741–10632, daily average solar flux incident on glass cover, Itavg. = 611–1113 W/m2 and blockage ratio (H/Z2) = 0, 0.33, 0.66 are presented. This work also compares the present results with simple double – pass solar air heater. It is found that the maximum percentage increments in THPP and Nu are 37 % and 79 % respectively at Re = 10247 and 9500 for BR = 0 compared to non-cross flow and simple double pass solar air heater. Based on the experimental data, correlations for the Nusselt number, friction factor and THPP have been developed.

Effects of Different Protein Sources on Growth Performance, Muscle Flavor Substances and Quality Structure in Triploid Crucian Carp

A 56-day feeding trial was conducted to evaluate the effect of different dietary protein sources on the growth performance, muscle flavor substances, and quality structure of Triploid Crucian Carp. Three isonitrogenous (32.00%), isolipidic (8.00%), and isoenergetic (18.00 MJ kg−1) practical diets were formulated. These diets consisted of fishmeal as the animal-derived protein source (AP), a combination of soybean meal and rapeseed meal as the plant-derived protein source (PP), and a mixture of fishmeal, soybean meal, and rapeseed meal as the mixed protein source (MP). Each diet was randomly assigned to triplicate tanks of fish and each tank was stocked with 25 fish (11.5 ± 0.4 g). The fish were fed until apparent satiation twice a day. The results showed a significant enhancement in the growth performance of Triploid Crucian Carp in the AP group compared with both the MP and PP groups (p &lt; 0.05). Dietary plant derived protein can remarkably reduce the crude lipid content and increase the moisture content of the whole body and the dorsal muscle (p &lt; 0.05). The antioxidant ability of fish in the PP group and MP group was better than that in the AP group (p &lt; 0.05). Regarding free amino acids composition of muscle, the contents of glycine, methionine, and lysine were significantly enhanced in the AP group, while the histidine content was significantly increased in the PP group (p &lt; 0.05). In terms of texture, dietary plant protein significantly improved the muscular hardness, gumminess, and chewiness. The activities of intestinal trypsin and alkaline phosphatase (ALP) of fish in the PP group were significantly higher than that in the AP group (p &lt; 0.05). The expression levels of hepatopancreas TOR and IGF1 genes in the PP group were significantly higher than that in the MP group (p &lt; 0.05). The present results indicate dietary fishmeal significantly improved the growth performance and muscular flavor glycine content, while dietary plant-based protein increased crude protein content, antioxidant ability, and muscular texture performance of Triploid Crucian Carp.

Extended calculations of energy levels and transition rates for Yb LVII

Abstract Extended energy levels and transition data for the Yb LVII are calculated with the GRASP2018 package, which is based on the multiconfiguration Dirac–Hartree–Fock and relativistic configuration methods. Complete and consistent data sets of energy levels, transition rates and lifetimes for electric-dipole (E1), electric-quadrupole (E2), magnetic-dipole (M1), and magnetic-quadrupole (M2) transitions among all these levels are given in this calculation. Three methods of uncertainty estimators are used to evaluate the accuracy of transition data. The computed results are also compared with other theoretical computations. The present results are reported as benchmarks for future calculations and measurements.

Challenges in the Detection of Polymyxin Resistance: From Today to the Future.

Antimicrobial resistance is known to be one of the greatest global threats to human health, and is one of the main causes of death worldwide. In this scenario, polymyxins are last-resort antibiotics to treat infections caused by multidrug-resistant bacteria. Currently, the reference test to evaluate the susceptibility of isolates to polymyxins is the broth microdilution method; however, this technique has numerous complications and challenges for use in laboratory routines. Several phenotypic methods have been reported as being promising for implementation in routine diagnostics, including the BMD commercial test, rapid polymyxin NP test, polymyxin elution test, culture medium with polymyxins, and the Polymyxin Drop Test, which require materials for use in routines and must be easy to perform. Furthermore, Sensititre®, molecular tests, MALDI-TOF MS, and Raman spectroscopy present reliable results, but the equipment is not found in most microbiology laboratories. In this context, this review discusses the main laboratory methodologies that allow the detection of resistance to polymyxins, elucidating the challenges and perspectives.

Effect of fluid elasticity and shear thinning on heat transfer from a heated sphere at moderate Reynolds numbers

The drag and heat transfer characteristics of an isothermal sphere in a FENE-P-type viscoelastic fluid have been studied in the steady axisymmetric flow regime. The governing equations, namely, mass, momentum, and energy equations, together with FENE-P type viscoelastic constitutive equations, have been solved using the finite volume method based opensource CFD code OpenFOAM over the following ranges of conditions: Reynolds number, 1 ≤ Re ≤ 100 ; Prandtl number, 1 ≤ Pr ≤ 50 ; Weissenberg number, 0 ​ ≤ Wi ≤ 10 and polymer extensibility parameter, 10 ≤ L 2 ≤ 500 for a fixed value of the polymer viscosity ratio of β = 0.5 . At low Reynolds numbers, fluid viscoelasticity causes an upward and downward shifting in the axial velocity profiles with reference to that in a Newtonian fluid along the upstream and downstream axis of the sphere, respectively. However, such a shift progressively diminishes with the increasing Reynolds number. Furthermore, a “velocity overshoot” and/or a “negative wake” is also observed in a viscoelastic polymer solution at low Reynolds numbers, and this is accentuated with the increasing Weissenberg number. The separation of boundary layers is seen to be suppressed with the increasing Weissenberg number. The drag coefficient decreases with the Reynolds number irrespective of the fluid type and the corresponding dependence on the Weissenberg number is found to be non-monotonic depending upon the values of Re and L 2. The average Nusselt number always increases with the increasing values of Re, Pr, and Wi and with the decreasing value of L 2. A limited number of simulations have also been carried out to show the effect of the temperature-dependent viscosity of the fluid on the flow dynamics and heat transfer characteristics. Finally, simple correlations for the drag coefficient and average Nusselt number are presented which not only capture the functional dependence but also can be used for the interpolation of the present results for the intermediate values of the governing parameters in a new application.

Diurnal retinal and choroidal gene expression patterns support a role for circadian biology in myopia pathogenesis

The prevalence of myopia (nearsightedness) is increasing to alarming levels, but its etiology remains poorly understood. Because both laboratory and clinical findings suggest an etiologic role for circadian rhythms in myopia development, we assayed gene expression by RNA-Seq in retina and choroid at the onset of unilateral experimental myopia in chick, isolating tissues every 4 h during a single 24-h period from myopic and contralateral control eyes. Occluded versus open eye gene expression differences varied considerably over the 24-h sampling period, with some occurring at multiple times of day but with others showing differences at only a single investigated timepoint. Some of the genes identified in retina or choroid of chick myopia were previously identified as candidate genes for common human myopia. Like differentially expressed genes, pathways identified by Gene Set Enrichment Analysis also varied dramatically by sampling time. Considered with other laboratory data, human genetic and epidemiology data, these findings further implicate circadian events in myopia pathogenesis. The present results emphasize a need to include time of day in mechanistic studies of myopia and to assess circadian biology directly in trying to understand better the origin of myopia and to develop more effective therapies.

Utilizing sulfuration of supercritical fluid treatment to improve sensitivity and humidity resistance of chip-type gas sensors

This research investigates a novel supercritical-fluid sulfuration (SCF-S) treatment used to enhance the sensitivity of SnO2-based chip-typed gas sensors and enable them to resist the influence of moisture during the alcohol detection. The fluid of supercritical state possesses helpful features, such as high permeability of gas and high solubility of water. The SCF-S process introduces the sulfuration penetrating the whole tin oxide membrane with sulfur bonding and thin film transformation. The surface morphology and the lattice structure have been confirmed by Scanning Electron Microscope (SEM) and X-ray diffraction analysis (XRD), respectively. To further verify the composition content after the novel SCF-S treatment, the qualitative and quantitative analyses are conducted, and both show the sulfur doping results. Moreover, different electronic properties are gained in the experiments where the concentration of alcohol and environment humidity vary. In order to understand the sensing reaction model after SCF treatment, response performance at different temperatures and the reliability of the reaction model are further investigated. From the present results, it is demonstrated that SCF-S process has a good potential in terms of the sensitive and selective detection of alcohol.

Finite element solutions of Double diffusion effects on three-dimensional MHD Nano-Powell-Erying fluid flow in presence of thermal and mass Biot numbers

This work uses a numerical method to investigate the effects of diffusion on the flow of three-dimensional magnetohydrodynamic (MHD) nanofluids. The applicable equations for this problem are derived from the Nano-Powell-Erying fluid model. The result of the differential equation is calculated by solving the problem using the finite element method. The numerical solutions are used to study the three-dimensional structures with the flow of nanofluid to investigate the influence of well-known fluid parameters. The study found that the Hartmann number and buoyancy ratio parameter have a significant impact on the velocity profile, while the Brownian motion and thermophoresis parameters, as well as the thermal and mass Biot numbers, are the main factors influencing the temperature and concentration fields. This study aims to analyse the effect of two different parameters on the flow of MHD nanofluids to improve our basic understanding of this phenomenon. The findings that were produced are compared to the previous work and incipiently, the present numerical results are veritably in good agreement with the previous results. The results of this study can be useful for the optimization and design of various engineering applications.

Clinical characteristics of SARS-CoV-2-associated encephalopathy in children: Nationwide epidemiological study

ObjectiveSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sometimes triggers acute encephalopathy as a serious neurological complication in children. We previously reported the clinico-radiological findings of SARS-CoV-2-associated encephalopathy. The advent of the SARS-CoV-2 omicron variant led to a marked increase in pediatric patients with coronavirus disease 2019 (COVID-19); however, epidemiological changes with acute encephalopathy according to the emergence of SARS-CoV-2 have not yet been documented. Therefore, the present study investigated epidemiological differences in SARS-CoV-2-associated encephalopathy during the BA.1/BA.2 and BA.5 predominant periods and also between SARS-CoV-2-associated and non-SARS-CoV-2-associated encephalopathy. MethodsWe conducted a nationwide survey of SARS-CoV-2-associated encephalopathy in Japanese children between June and November 2022. We compared the present results during the BA.5 predominant period and previous findings during the BA.1/BA.2 predominant period. We also compared the clinico-radiological syndromes of encephalopathy between SARS-CoV-2-associated and non-SARS-CoV-2-associated encephalopathy. ResultsAlthough many patients with SARS-CoV-2-associated encephalopathy in the BA.5 predominant period had seizures as their initial symptoms, no significant differences were observed in the clinical features. Patients with SARS-CoV-2-associated encephalopathy had worse outcomes than those with non-SARS-CoV-2-associated encephalopathy (p-value = 0.003). Among 103 patients with SARS-CoV-2-associated encephalopathy, 14 (13.6%) had severe types of acute encephalopathy, namely, encephalopathy with acute fulminant cerebral edema (AFCE) and hemorrhagic shock and encephalopathy syndrome (HSES). Also, 28 (27.2%) patients with SARS-CoV-2-associated encephalopathy had poor outcome: severe neurological sequelae or death. Ninety-five patients (92.2%) were not vaccinated against SARS-CoV-2. ConclusionsIn SARS-CoV-2-associated encephalopathy, high percentages of AFCE and HSES can result in poor outcomes.

General low alertness in people with obstructive sleep apnea.

In patients with obstructive sleep apnea (OSA), a previous study using a Go/No-Go task reported an average attention deficit. However, the temporal dynamics of such a deficit are unknown. Here, we investigated whether attention deficits in different subdomains increased as the test progressed. We also investigated the effect of target frequency and speed of stimulus presentation on performance. Twenty-seven untreated people with OSA and 27 age- and sex-matched controls underwent a 15-minute Go/No-Go task, divided into 6 blocks. Each block was subdivided into 3 different interstimulus intervals (1, 2, and 4 seconds). Three blocks had a low and three had a high target probability (20% and 80%, respectively). Reaction time (alertness), variability of reaction time (sustained attention), commission errors (response inhibition), and omission errors (focused attention) were measured. Alertness was lower in the group with OSA compared with controls, as evidenced by a significantly higher average reaction time. This effect was seen from the start of the task and continued until the end but did not increase in test progression. The temporal pattern of intrinsic alertness deficits in patients with OSA was found to be independent of target frequency or interstimulus interval. The primary attention problem in OSA is on the alertness subdomain irrespective of the number of required responses or speed of stimulus presentation. The present results support the notion that OSA is distinct from other neurological and psychiatric conditions, such as depression or chronic pain. The results also suggest significant concerns regarding daily life activities (eg, driving). de Souza Bezerra ML, van Duinkerken E, Simões E, Schmidt SL. General low alertness in people with obstructive sleep apnea. J Clin Sleep Med. 2024;20(5):689-698.

Asymmetric framework motion of TCRαβ controls load-dependent peptide discrimination.

Mechanical force is critical for the interaction between an αβ T cell receptor (TCR) and a peptide-bound major histocompatibility complex (pMHC) molecule to initiate productive T-cell activation. However, the underlying mechanism remains unclear. We use all-atom molecular dynamics simulations to examine the A6 TCR bound to HLA-A*02:01 presenting agonist or antagonist peptides under different extensions to simulate the effects of applied load on the complex, elucidating their divergent biological responses. We found that TCR α and β chains move asymmetrically, which impacts the interface with pMHC, in particular the peptide-sensing CDR3 loops. For the wild-type agonist, the complex stabilizes in a load-dependent manner while antagonists destabilize it. Simulations of the Cβ FG-loop deletion, which reduces the catch bond response, and simulations with in silico mutant peptides further support the observed behaviors. The present results highlight the combined role of interdomain motion, fluctuating forces, and interfacial contacts in determining the mechanical response and fine peptide discrimination by a TCR, thereby resolving the conundrum of nearly identical crystal structures of TCRαβ-pMHC agonist and antagonist complexes.

Genetic diversity and seroprevalence of Toxoplasma gondii in COVID‑19 patients; a first case-control study in Iran

BackgroundToxoplasmosis is a serious or life-threatening disease in immunosuppressed patients and pregnant women. This study examined the likely association between Toxoplasma gondii infection and COVID-19 patients with moderate illness.MethodsSeventy blood samples were collected from patients at the Health Reference Laboratory of Tabriz, Northwest Iran from April 2021 to September 2021. In addition, 70 healthy subjects of the same age (37 ± 15 years) and sex distribution were ethnically matched. Sera samples were examined for the detection of anti-Toxoplasma antibodies using ELISA. Nested-PCR targets were amplified based on the B1 and GRA6 genes. GRA6 amplicons were subjected to sequencing and phylogenetic analysis.ResultsThe seroprevalence of toxoplasmosis based on IgG titer was 35.7% in the COVID‑19 patients and 27.1% in the control group, representing not to be associated with the Toxoplasma seropositivity in COVID‑19 patients (P = 0.18) compared to healthy subjects. Anti-T. gondii IgM was not found in any of the patients and healthy individuals. According to PCR amplification of the B1 and GRA6 genes, the frequency of T. gondii in COVID-19 patients was 14.2% (10/70). However, no T. gondii infection was detected in the healthy group. The CD4+T cell count was relatively lower in toxoplasmosis-infected patients (430–450 cells/mm3) than in control group (500–1500 cells/mm3). High genetic diversity (Hd: 0.710) of the type I strain of T. gondii was characterized in the patients. Present results showed that consumption of raw vegetables and close contact with stray cats can increase the transmission of T. gondii to COVID-19 patients (P < 0.01).ConclusionsThe current study revealed that T. gondii type I infection is unequivocally circulating among the COVID-19 patients in Tabriz; However, no significant association was observed between the occurrence of Toxoplasma and the severity of COVID-19. To make more accurate health decisions, multicenter investigations with a larger sample size of different ethnic groups of the Iranian population are needed.

The effect of prior period adjustments on equity and ROE of companies listed on B3's New Market

Purpose: To analyze the effect of prior period adjustments (PPA) on Equity and on Return on Equity (ROE).&#x0D; Methodology: The Statements of Changes in Equity and the Explanatory Notes of the companies listed on the B3’s New Market, from 2010 to 2019, were researched. To analyze the effects of PPA on equity and ROE, the Wilcoxon test was applied.&#x0D; Results: The majority of the identified PPA pertain to changes in accounting policies, notably related to the application of IFRS 9/CPC 48 and IFRS 15/CPC 47 in 2018. This means that companies chose to recognize the effects of adopting these standards retrospectively, with a cumulative effect on equity, without presenting comparative information (accounting choice). There was a statistically significant difference between the average variations in adjusted and unadjusted equity and return on equity (ROE). In other words, it is observed that changes in accounting policies and/or error corrections influence the analysis of these indicators. It is important to note that PPA should not affect the net income for the current period, suggesting that the effects resulting from changes in accounting policies and errors tend to protect present and/or future results at the expense of past results.&#x0D; Contributions of the Study: The main contribution of the study lies in evaluating changes in the equity that do not necessarily result from operating performance or financing strategies, but arising from changes in accounting criteria or errors, which may affect other equity components.