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1.
Molecules ; 29(8)2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38675627

RESUMO

The abietane diterpenoid 7α-acetoxy-6ß-hydroxyroyleanone (Roy) isolated from Plectranthus grandidentatus demonstrates cytotoxicity across numerous cancer cell lines. To potentiate anticancer attributes, a series of semi-synthetic Roy derivatives were generated and examined computationally. ADMET predictions were used to evaluate drug-likeness and toxicity risks. The antineoplastic potential was quantified by PASS. The DFT models were used to assess their reactivity and stability. Molecular docking determined cancer-related protein binding. MS simulations examined ligand-protein stability. Additionally, network pharmacology was used to identify potential targets and signaling pathways. Favorable ADME attributes and acceptable toxicity profiles were determined for all compounds. Strong anticancer potential was shown across derivatives (Pa 0.819-0.879). Strategic modifications altered HOMO-LUMO gaps (3.39-3.79 eV) and global reactivity indices. Favorable binding was revealed against cyclin-dependent kinases, BCL-2, caspases, receptor tyrosine kinases, and p53. The ligand exhibited a stable binding pose in MD simulations. Network analysis revealed involvement in cancer-related pathways. In silico evaluations predicted Roy and derivatives as effective molecules with anticancer properties. Experimental progress is warranted to realize their chemotherapeutic potential.


Assuntos
Abietanos , Diterpenos , Simulação de Acoplamento Molecular , Plectranthus , Humanos , Abietanos/química , Abietanos/farmacologia , Plectranthus/química , Simulação por Computador , Antineoplásicos/farmacologia , Antineoplásicos/química , Linhagem Celular Tumoral , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/química , Simulação de Dinâmica Molecular , Estrutura Molecular
2.
Pharmaceuticals (Basel) ; 16(9)2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37765008

RESUMO

The phenomenon of drug resistance in micro-organisms necessitates the search for new compounds capable of combating them. Fungi emerge as a promising source of such compounds as they produce a wide range of secondary metabolites with bacteriostatic or fungistatic activity. These compounds can serve as alternatives for commonly used antibiotics. Furthermore, fungi also accumulate compounds with antiviral activity. This review focuses on filamentous fungi and macrofungi as sources of antimicrobial compounds. The article describes both individual isolated compounds and extracts that exhibit antibacterial, antifungal, and antiviral activity. These compounds are produced by the fruiting bodies and mycelium, as well as the biomass of mycelial cultures. Additionally, this review characterizes the chemical compounds extracted from mushrooms used in the realm of cosmetology; specifically, their antimicrobial activity.

3.
Nutrients ; 15(13)2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37447342

RESUMO

Anthocyanins are flavonoid compounds that are abundantly present in fruits and vegetables. These compounds contribute to the color of these foods and offer various health benefits to consumers due to their biological properties. There are more than 1000 types of anthocyanins in nature, all derived from 27 anthocyanidin aglycones that have different glycosylations and acylations. Malvidin is one of the most well-known anthocyanidins. Several studies, including those conducted on cell lines, animals, and humans, have suggested that malvidin and its glycosides possess anti-carcinogenic, diabetes-control, cardiovascular-disease-prevention, and brain-function-improvement properties. These health benefits are primarily attributed to their antioxidant and anti-inflammatory effects, which are influenced by the molecular mechanisms related to the expression and modulation of critical genes. In this article, we review the available information on the biological activity of malvidin and its glycosides concerning their health-promoting effects.


Assuntos
Antocianinas , Glicosídeos , Animais , Humanos , Antocianinas/farmacologia , Antocianinas/metabolismo , Glicosídeos/farmacologia , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Anti-Inflamatórios/farmacologia
4.
Cells ; 12(11)2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37296672

RESUMO

The aim of this study was to examine the effect of the modified light spectrum of glass containing red luminophore on the performance of the photosynthetic apparatus of two types of lettuce cultivated in soil in a greenhouse. Butterhead and iceberg lettuce were cultivated in two types of greenhouses: (1) covered with transparent glass (control) and (2) covered with glass containing red luminophore (red). After 4 weeks of culture, structural and functional changes in the photosynthetic apparatus were examined. The presented study indicated that the red luminophore used changed the sunlight spectrum, providing an adequate blue:red light ratio, while decreasing the red:far-red radiation ratio. In such light conditions, changes in the efficiency parameters of the photosynthetic apparatus, modifications in the chloroplast ultrastructure, and altered proportions of structural proteins forming the photosynthetic apparatus were observed. These changes led to a decrease of CO2 carboxylation efficiency in both examined lettuce types.


Assuntos
Clorofila , Fotossíntese , Clorofila/metabolismo , Luz , Cloroplastos/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Lactuca/metabolismo
5.
Sci Rep ; 13(1): 4716, 2023 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-36949077

RESUMO

A satisfactory model of the biopotentials propagating through the human body is essential for medical diagnostics, particularly for cardiovascular diseases. In our study, we develop the theory, that the propagation of biopotential of cardiac origin (ECG signal) may be treated as the propagation of low-frequency endogenous electromagnetic wave through the human body. We show that within this approach, the velocity of the ECG signal can be theoretically estimated, like for any other wave and physical medium, from the refraction index of the tissue in an appropriate frequency range. We confirm the theoretical predictions by the comparison with a direct measurement of the ECG signal propagation velocity and obtain mean velocity as low as v=1500 m/s. The results shed new light on our understanding of biopotential propagation through living tissue. This propagation depends on the frequency band of the signal and the transmittance of the tissue. This finding may improve the interpretation of the electric measurements, such as ECG and EEG when the frequency dependence of conductance and the phase shift introduced by the tissue is considered. We have shown, that the ECG propagation modifies the amplitude and phase of signal to a considerable extent. It may also improve the convergence of inverse problem in electrocardiographic imaging.


Assuntos
Doenças Cardiovasculares , Eletrocardiografia , Humanos , Doenças Cardiovasculares/diagnóstico
6.
Int J Mol Sci ; 24(2)2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36675294

RESUMO

The work is devoted to preparing and characterizing the properties of photosensitive composites, based on chitosan proposed for photodynamic therapy. Chitosan films with a 5% addition of two BODIPY dyes were prepared by solution casting. These dyes are dipyrromethene boron derivatives with N-alkyl phthalimide substituent, differing in the presence of iodine atoms in positions 2 and 6 of the BODIPY core. The spectral properties of the obtained materials have been studied by infrared and UV-vis absorption spectroscopy and fluorescence, both in solutions and in a solid state. Surface properties were investigated using the contact angle measurement. The morphology of the sample has been characterized by Scanning Electron and Atomic Force Microscopy. Particular attention was paid to studying the protein absorption and kinetics of the dye release from the chitosan. Adding BODIPY to the chitosan matrix leads to a slight increase in hydrophilicity, higher structure heterogeneity, and roughness, than pure chitosan. The presence of iodine atoms in the BODIPY structure caused the bathochromic effect, but the emission quantum yield decreased in the composites. It has been found that BODIPY-doped chitosan interacts better with human serum albumin and acidic α-glycoprotein than unmodified chitosan. The release rate of dyes from films immersed in methanol depends on the iodine present in the structure.


Assuntos
Quitosana , Corantes Fluorescentes , Humanos , Corantes Fluorescentes/química , Boro/química
7.
Sci Rep ; 12(1): 18658, 2022 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-36333591

RESUMO

This study focuses on obtaining and characterizing novel chitosan-based biomaterials containing cannabis oil to potentially promote wound healing. The primary active substance in cannabis oil is the non-psychoactive cannabidiol, which has many beneficial properties. In this study, three chitosan-based films containing different concentrations of cannabis oil were prepared. As the amount of oil increased, the obtained biomaterials became rougher as tested by atomic force microscopy. Such rough surfaces promote protein adsorption, confirmed by experiments assessing the interaction between human albumin with the obtained materials. Increased oil concentration also improved the films' mechanical parameters, swelling capacity, and hydrophilic properties, which were checked by the wetting angle measurement. On the other hand, higher oil content resulted in decreased water vapour permeability, which is essential in wound dressing. Furthermore, the prepared films were subjected to an acute toxicity test using a Microtox. Significantly, the film's increased cannabis oil content enhanced the antimicrobial effect against A. fischeri for films in direct contact with bacteria. More importantly, cell culture studies revealed that the obtained materials are biocompatible and, therefore, they might be potential candidates for application in wound dressing materials.


Assuntos
Cannabis , Quitosana , Humanos , Bandagens/microbiologia , Cicatrização , Materiais Biocompatíveis/farmacologia
8.
Molecules ; 27(15)2022 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-35956959

RESUMO

This article presents the first successful application of a capillary electrophoresis-microscale thermophoresis tandem technique (CE-MST) for determining the values of equilibrium constant, realized by connecting online the CE and MST instruments using a fused-silica capillary. The acid-base dissociation of fluorescein isothiocyanate, expressed by the acidity constant value (pKa), was used as a model. The measurement procedure consisted of introducing a mixture containing the analyte and a deliberately added interferent into the CE capillary, electrophoretic separation of the analyte from the interferent, the detection of the analyte with a CE-integrated detector, detection with a MST detector, and then stopping the flow temporarily by turning off the voltage source to conduct the thermophoretic measurement. The analysis of migration times, peak areas and MST responses obtained concurrently for the same sample allowed us to determine the pKa value using three independent methods integrated within one instrumentation. The analyte was effectively separated from the interferent, and the acidity values turned out to be consistent with each other. An attempt was also made to replace the standard commercial CE instrument with a home-made portable CE setup. As a result, the similar pKa value was obtained, at the same time proving the possibility of increasing cost efficiency and reducing energy consumption. Overall, the CE-MST technique has a number of limitations, but its unique analytical capabilities may be beneficial for some applications, especially when sample separation is needed prior to the thermophoretic measurement.


Assuntos
Ácidos , Eletroforese Capilar , Eletroforese Capilar/métodos , Fluoresceína , Isotiocianatos
9.
Int J Mol Sci ; 23(14)2022 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-35886996

RESUMO

In recent years, new cross-linkers from renewable resources have been sought to replace toxic synthetic compounds of this type. One of the most popular synthetic cross-linking agents used for biomedical applications is glutaraldehyde. However, the unreacted cross-linker can be released from the materials and cause cytotoxic effects. In the present work, dialdehyde starch nanocrystals (NDASs) were obtained from this polysaccharide nanocrystal form as an alternative to commonly used cross-linking agents. Then, 5-15% NDASs were used for chemical cross-linking of native chitosan (CS), gelatin (Gel), and a mixture of these two biopolymers (CS-Gel) via Schiff base reaction. The obtained materials, forming thin films, were characterized by ATR-FTIR, SEM, and XRD analysis. Thermal and mechanical properties were determined by TGA analysis and tensile testing. Moreover, all cross-linked biopolymers were also characterized by hydrophilic character, swelling ability, and protein absorption. The toxicity of obtained materials was tested using the Microtox test. Dialdehyde starch nanocrystals appear as a beneficial plant-derived cross-linking agent that allows obtaining cross-linked biopolymer materials with properties desirable for biomedical applications.


Assuntos
Proteínas Sanguíneas , Quitosana , Reagentes de Ligações Cruzadas , Gelatina , Nanopartículas , Amido , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Proteínas Sanguíneas/química , Proteínas Sanguíneas/metabolismo , Quitosana/química , Quitosana/metabolismo , Reagentes de Ligações Cruzadas/química , Reagentes de Ligações Cruzadas/metabolismo , Gelatina/química , Gelatina/metabolismo , Humanos , Nanopartículas/química , Nanopartículas/metabolismo , Amido/análogos & derivados , Amido/química , Amido/metabolismo
10.
Anal Bioanal Chem ; 414(21): 6355-6370, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35511247

RESUMO

The stability of psychotropic substances representing various drug groups important from the perspective of forensic chemistry, including benzodiazepines, antidepressants, carbamazepine, cocaine, and their selected metabolites, was investigated for 1 month in two alternative biological matrices, vitreous humor and liver homogenate. Three different thermal storage conditions (-20, 4, and 20 °C) were tested. Liquid chromatography-mass spectrometry (LC-MS) analysis was preceded by an effective solid-phase microextraction (SPME) procedure. The results were statistically analyzed using one-way ANOVA to find significant concentration variations over time. The results obtained allowed for dividing the analytes into four groups: stable under all tested conditions, only at -20 and 4 °C, only at 20 °C, and overall unstable. Nordiazepam, venlafaxine, and cocaine and its metabolites turned out to be the most unstable substances, while fluoxetine showed the highest storage stability in both matrices. The SPME/LC-MS method was comprehensively evaluated according to the principles of white analytical chemistry (WAC), which reconcile the greenness and functionality of the method. A close to 100% whiteness score proves its sustainability and suitability for the intended application.


Assuntos
Cocaína , Corpo Vítreo , Cromatografia Líquida , Cocaína/análise , Fígado , Psicotrópicos/análise , Microextração em Fase Sólida/métodos , Corpo Vítreo/química
11.
Diagnostics (Basel) ; 12(4)2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35453906

RESUMO

The purpose of this study was to investigate whether routine blood tests and clinical characteristics can predict in-hospital mortality in COVID-19. Clinical data of 285 patients aged 59.7 ± 10.3 yrs. (males n = 189, females n = 96) were retrospectively collected from December 2020 to June 2021. Routine blood tests were recorded within the 1st hour of admission to hospital. The inflammatory variables, such as C-reactive protein (CRP), procalcitonin (PCT), neutrophils−lymphocyte ratio (NLR) and the systemic inflammatory index (SII), exceeded the reference values in all patients and were significantly higher in deceased patients (n = 108) compared to survivors (n = 177). The log-rank test for comparing two survival curves showed that patients aged ≥60.5 years, with PCT ≥ 0.188 ng/mL or NLR ≥ 11.57 103/µL were at a greater risk of death. NLR demonstrated a high impact on the COVID-19 mortality (HR 1.317; 95%CI 1.004−1.728; p < 0.05), whereas CRP and SII showed no effect (HR 1.000; 95%CI 1.000−1.004; p = 0.085 and HR 1.078; 95%CI 0.865−1.344; p = 0.503, respectively). In the first Polish study including COVID-19 patients, we demonstrated that age in relation to simple parameters derived from complete blood cell count has prognostic implications in the course of COVID-19 and can identify the patients at a higher risk of in-hospital mortality.

12.
Materials (Basel) ; 15(7)2022 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-35407898

RESUMO

In this paper, the issue of self-compacting concrete (SCC) with the addition of polyethylene terephthalate (PET) recycled aggregate is addressed. The PET utilized was a waste fraction in the PET-bottle-recycling process. The implementation of waste in concrete mixes has a positive impact on their environmental and social profile; however, technical requirements are not necessarily met. In this investigation, PET was used as a substitute for fine aggregate in quantities ranging from 0 to 20% in increments of 5%. Both the flow properties of SCC mixes and the hardened SCC properties (compressive strength, splitting tensile strength, modulus of elasticity, and Poisson ratio) were investigated. Additionally, non-destructive tests (ultrasound and sclerometric) were performed to determine the correlation curves. The research revealed that both the flow properties and the parameters of the hardened concrete deteriorated with the PET content. Concrete with 20% PET replacement did not meet the self-compacting requirements and its compressive strength decreased by almost 50%. However, it was noted that replacing fine aggregate with PET aggregate in the amount of 5% did not significantly alter the concrete parameters and could be an attractive alternative to traditional concretes. Based on non-destructive testing, correlation curves were constructed that could be applicable to the future quality assessment of self-compacting concretes with recycled PET aggregate.

13.
Arch Med Sci ; 18(2): 440-447, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35316916

RESUMO

Introduction: Due to an imbalanced redox status, cancer cells generate intrinsically higher levels of reactive oxygen species (ROS) compared to normal cells. Targeting ROS is an important therapeutic strategy for cancer as exemplified by cancer drugs, which induce ROS-dependent synergistic cytotoxicity in gastric cancer cells. The present study was designed to assess the level of selected oxidative stress biomarkers in blood plasma derived from gastric cancer patients. Material and methods: The study assessed the oxidative/nitrative biomarkers in blood plasma isolated from 51 gastric (adenocarcinoma) cancer patients, compared to a control group of 32 healthy volunteers. Oxidative stress was evaluated using a panel of biomarkers such as plasma protein thiol groups and 3-nitrotyrosine levels as well as indicators of plasma lipid peroxidation, i.e. lipid hydroperoxides (LOOH) and thiobarbituric acid-reactive substances (TBARS). Additionally, the total antioxidant capacity of blood plasma (non-enzymatic capacity of blood plasma, NEAC) was also estimated. Results: Our results showed that patients with gastric cancer had significantly different levels of thiol groups (lower, p < 0.001) and 3-nitrotyrosine (higher, p < 0.0001), LOOH (higher, p < 0.05), TBARS (higher, p < 0.05), NEAC (lower, p < 0.0001), compared to the control group. Conclusions: The present study indicates considerable oxidative/nitrative stress in gastric cancer patients. Our pilot study shows that not a single marker, but a biomarker panel, may be a more reliable representation of oxidative stress in patients with gastric cancer.

14.
Molecules ; 27(3)2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35163949

RESUMO

MicroScale thermophoresis (MST) is a rapidly developing bioanalytical technique used routinely for the examination of ligand-target affinity. It has never been used so far for the analysis of acid-base dissociation and the determination of pKa constant. This work is the-proof-of-concept of this new idea. It demonstrates that the pKa values obtained from the thermophoretic data are consistent with the reference methods. As a result, the analytical potential and utility of the MST technology can become even greater, especially if the new detection system of thermophoretic movement will be developed in the future. Even now, taking into account the necessity to use fluorescence, the proposed method may be useful in many respects.

15.
ISA Trans ; 125: 179-188, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34238518

RESUMO

The paper presents a stability analysis of a closed-loop system with an active disturbance rejection control (ADRC) algorithm and a reduced-order extended state observer (RESO). The controller is designed for first-order plus delay time processes, and one of the input signals to the RESO is delayed to compensate for the effect of the system delay. If the process delay is known, perfect synchronization between the observer input signals can be achieved. In a more realistic case, the process delay is not precisely known, and the resulting imperfect synchronization may lead to instability of the closed-loop system. The perfect synchronization case shows that the closed-loop system can be stabilized for any delay. For the imperfect synchronization case, delay-dependent stability conditions are derived for a simple tuning method.

16.
ISA Trans ; 128(Pt B): 159-170, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34839905

RESUMO

Safe and economic operation of an open-cathode proton exchange membrane fuel cell (PEMFC) requires an efficient thermal management strategy. The stack temperature regulation in PEMFC is, however, challenging due to often stringent set-point tracking tasks, frequent load fluctuations, constrained manipulated variables, and various modeling uncertainties and nonlinearities. To this end, a feed-forward offset-free model predictive control (MPC) approach, aiming at uncertainties resolving and disturbance mitigation, is developed to simultaneously address the above difficulties. In the proposed framework, the information about the measured power load fluctuations is used in the optimization algorithm as feed-forward information to eventually mitigate the influence of load fluctuations on the controlled output and increases the overall control quality. Additionally, the unmodeled dynamics and the other unmeasurable disturbances/uncertainties are collectively considered as an extended state of the system (to achieve zero static errors) and the on-line reconstructed aggregated disturbances is continuously sent to the MPC algorithm to increase its optimization performance and to achieve offset-free control objectives. The obtained results are quantitatively compared with conventional control strategies for PEMFCs, including a model-based PI controller, its modification utilizing disturbance feed-forward, and a standard offset-free MPC (i.e. without feed-forward). Both the simulations, realized in MATLAB/Simulink, and hardware experiments, conducted on a 500 W PEMFC testbed, show excellence of the proposed feed-forward offset-free MPC consisting in faster temperature tracking and higher robustness. The obtained satisfactory results show the introduced control solution to be a promising prospect and help accelerating further applications of PEMFCs.

17.
Psychol Res Behav Manag ; 14: 1877-1888, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34853542

RESUMO

PURPOSE: This study examines the indirect relationship between optimism and life satisfaction via healthy behavior among health sciences students. PARTICIPANTS AND METHODS: The cross-sectional study involved 349 health sciences students, including 58% of women, ranging in age between 19 and 30 years (M = 22.15, SD = 1.83). Self-report questionnaires were used to measure dispositional optimism (the Life Orientation Test-Revised, LOT-R), life satisfaction (Satisfaction with Life Scale, SWLS), and health behaviors (Health Behavior Inventory, HBI), with four subscales: healthy diet (HD), preventive behavior (PB), positive mental attitudes (PMA), and healthy practices (HP). In addition, a single mediation model (with the total HBI as mediator) was compared with a parallel mediation model (with four subscales of the HBI). Gender was controlled as a confounding variable. RESULTS: Women scored higher in the total HBI (p < 0.01), HD (p < 0.001) and PB (p < 0.01) than men, while men scored slightly higher in dispositional optimism (p < 0.01). General health behavior (total HBI) completely mediates the relationship between dispositional optimism and life satisfaction, R 2 = 0.32. In the parallel model, only PMA was determined as a mediator of the association between dispositional optimism and satisfaction with life, R 2 = 0.36. The single mediation model showed perfect fit (X2/df = 0.00, RMSEA = 0.00, SRMR = 0.00, CFI = 1.00, IFI = 1.00, NFI = 1.00), better than the parallel mediation model (X2/df = 2.353, p = 0.095, RMSEA = 0.062, SRMR = 0.020, CFI = 0.995, IFI = 995, NFI = 991). CONCLUSION: The interplay mechanism between personal resources and behavioral health-related habits may explain 32% of life satisfaction variance. The intervention focused on increasing optimistic expectancies and health behaviors should be implemented in universities to increase students' well-being and prevent depression.

18.
Front Chem ; 9: 753399, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34722459

RESUMO

The recently proposed concept of White Analytical Chemistry (WAC), referring to the Red-Green-Blue color model, combines ecological aspects (green) with functionality (red and blue criteria), presenting the complete method as "white". However, it is not easy to carry out an overall quantitative evaluation of the analytical method in line with the WAC idea in an objective manner. This paper outlines the perspective of the future development of such a possibility by attempting to answer selected questions about the evaluation process. Based on the study consisting in the evaluation of selected model methods by a group of 12 independent analysts, it was shown how well individual criteria are assessed, whether the variability of assessments by different people is comparable for each criterion, how large it is, and whether averaging the scores from different researchers can help to choose the best method more objectively.

19.
Molecules ; 26(20)2021 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-34684849

RESUMO

In this paper, a novel procedure for preparing calibration solutions for capillary electrophoresis (CE)-based quantitative analysis is proposed. Our approach, named the automated hydrodynamically mediated technique (AHMT), uses a capillary and a pressure system to deliver the expected amount of working solution and diluent directly to a sample vial. As a result, calibration solutions are prepared automatically inside the CE instrument, without any or with minimal manual operation. Two different modes were tested: forward and reverse, differing in the direction of hydrodynamic flow. The calibration curves obtained for a model mixture of analytes using AHMT were thorough compared to the standard procedure based on manual pipetting. The results were consistent, though the volume of obtained calibration solutions and the potential risk of random errors were significantly minimized by AHMT. Its effectiveness was further enhanced by the application of SCIEX® nanoVials, reducing the actual volume of calibration solutions down to 10 µL.

20.
Materials (Basel) ; 14(17)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34500867

RESUMO

This paper presents a methodology of inverse tomography transformation in eddy current tomography with the use of continuous optimization of reference defect parameters. Ferromagnetic steel samples with rectangular air inclusion defects of known dimensions were prepared and measured using an eddy current tomography setup. FEM-based (Finite Element Method based) forward tomography transformation was developed and utilized in inverse tomography transformation. The presented method of inverse tomography transformation is based on the continuous optimization of parameters that can describe the sample, such as the diameter and dimensions of the reference defect. The obtained results of inverse tomography transformation were in high accordance with the real parameters of the samples. Additionally, the presented method had acceptable repeatability. The obtained values of the sample parameters fit within the range of expanded uncertainty when compared to the real parameters of the sample.

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