Bone samples' behavior in sunlight, IR light, and temperature increase with FEM simulation.

Biological and environmental factors produce biochemical processes that modify the bone structure. A few studies have attempted to show the adverse biological effects of sun radiation. The bone tissue exposures to infrared and sunlight radiation are analyzed by using focused sound, characterization spectroscopy techniques, and image processing. The study is complemented with a finite element method simulation on temperature behaviors. The crystal morphology on the bone hydroxyapatite and functional groups was characterized by X-ray diffraction and infrared spectroscopy. The infrared spectra confirmed the hydroxyl group of bovine hydroxyapatite, amines, and lipids are also correlated with modifications of the hydroxyapatite. The diffractograms showed the characteristic peaks of hydroxyapatite, with the main intensity at 2θ = 32.02°. Bone samples exposed to sun radiation presented a peak at 2θ = 27.5°, evidencing the possible formation of ß-TCP y α-TCP. The analysis with the spectroscopy techniques about the structural changes in the samples suggests interpreting an increase of sound obtained by expanding the exposure time. It is possible to verify that there are some structural changes in the bone samples due to exposure to non-ionizing radiation. These results show an increase in the registered intensity sound correlated with the interpretation of the structural changes of bone. Thanks to the different novel analysis techniques established in the present study, it could establish the changes that experienced the bone structure under different sources of radiation, which will help to better detect scenarios of bone deficiency.

An Extremely Low-Frequency Vortex Magnetic Field Modifies Protein Expression, Rearranges the Cytoskeleton, and Induces Apoptosis of a Human Neuroblastoma Cell Line.

Homogeneous extremely low-frequency electromagnetic fields (ELF-EMFs) alter biological phenomena, including the cell phenotype and proliferation rate. Heterogenous vortex magnetic fields (VMFs), a new approach of exposure to magnetic fields, induce systematic movements on charged biomolecules from target cells; however, the effect of VMFs on living systems remains uncertain. Here, we designed, constructed, and characterized an ELF-VMF-modified Rodin's coil to expose SH-SY5Y cells. Samples were analyzed by performing 2D-differential-gel electrophoresis, identified by MALDI-TOF/TOF, validated by western blotting, and characterized by confocal microscopy. A total of 106 protein spots were differentially expressed; 40 spots were downregulated and 66 were upregulated in the exposed cell proteome, compared to the control cell proteome. The identified spots are associated with cytoskeleton and cell viability proteins, and according to the protein-protein interaction network, a significant interaction among them was found. Our data revealed a decrease in cell survival associated with apoptotic cells without effects on the cell cycle, as well as evident changes in the cytoskeleton. We demonstrated that ELF-VMFs, at a specific frequency and exposure time, alter the cell proteome and structurally affect the target cells. This is the first report showing that VMF application might be a versatile system for testing different hypotheses in living systems, using appropriate exposure parameters.© 2022 Bioelectromagnetics Society.

A Ferrofluid with High Specific Absorption Rate Prepared in a Single Step Using a Biopolymer.

An exhaustive characterization of the physicochemical properties of gum arabic (GA)-coated Fe3O4 magnetic nanoparticles was conducted in this work. These nanoparticles were obtained via the in-situ coprecipitation method (a fast single-step method) in two GA:Fe ratios, 10:1 and 20:1, respectively. Several experimental techniques were applied in the characterization process, all of them described below. Using Transmission Electron Microcopy images, they were shown to have spherical-like morphology with 11 nm diameter. The Fourier Transform Infrared spectra confirmed the attachment of the GA on the surface of the magnetic nanoparticles (MNPs), providing good colloidal stability from pH 7 to 8. The thickness of the coatings (1.7 nm and 1.1 nm) was determined using thermogravimetric measurements. A high specific absorption rate and superparamagnetic properties were determined using alternant and static magnetic fields, respectively. The GA-coated MNPs were non-cytotoxic, according to tests on HT-29 human intestine cells. Additionally, HT-29 cells were exposed to magnetic fluid hyperthermia at 530 kHz, and the induction of cell death by the magnetic field, due to the heating of GA-coated MNP, was observed.

Focused ultrasound simulation through cortical bone by finite element method.

Bone tissue is constantly changed adapting to its mechanical environment and capable of repairing itself. Ultra-sound has recently been used as a diagnostic technique to assess bone conditions. To optimize the experimental model as best as possible computational simulation techniques have been focused on clinical applications in bone. This study aims to analyze by finite element method the propagation of ultrasound waves along the cortical bone. The wave propagation phenomenon is well studied and described by the Helmholtz equation. The first part of the work analytically solves the Helmholtz equation, and later the COMSOL Multiphysics software is used. It was established a cylindrical geometry as the bone sample. The software analyzes with "Pressure Acoustic, Frequency Domain" module. An extremely fine mesh is used for the solution in order not to lose information. According to the analytical solution, the results show the behavior of the acoustic pressure waves throughout the samples. In addition, attenuation coefficients are calculated for biological materials such as bone and muscle. Simulation methods allow to analyze adjustable parameters in the development of new devices. Thus, optimizing resources and allowing the researcher to better understanding the problem to be solved.

Low frequency vortex magnetic field reduces amyloid ß aggregation, increase cell viability and protect from amyloid ß toxicity.

Plaques formed by abnormal accumulation of amyloid ß-peptide (Aß) lead to onset of Alzheimer's disease (AD). Pharmacological treatments do not reduce Aß aggregation neither restore learning and memory. Noninvasive techniques have emerged as an alternative to treat AD, such as stimulation with electromagnetic fields (EMF) that decrease Aß deposition and reverses cognitive impairment in AD mice, even though some studies showed side effects on parallel magnetic fields stimulation. As a new approach of magnetic field (MF) stimulation, vortex magnetic fields (VMF) have been tested inducing a random movement of charged biomolecules in cells, promoting cell viability and apparently safer than parallel magnetic fields. In this study we demonstrate the effect of VMF on Aß aggregation. The experimental strategy includes, i) design and construction of a coil capable to induce VMF, ii) evaluation of VMF stimulation on Aß peptide induced-fibrils-formation, iii) evaluation of VMF stimulation on SH-SY5Y neuroblastoma cell line in the presence of Aß peptide. We demonstrated for the first time that Aß aggregation exposed to VMF during 24 h decreased ~ 86% of Aß fibril formation compared to control. Likewise, VMF stimulation reduced Aß fibrils-cytotoxicity and increase SH-SY5Y cell viability. These data establish the basis for future investigation that involve VMF as inhibitor of Aß-pathology and indicate the therapeutic potential of VMF for AD treatment.

Evaluation of micronuclei in oral mucosa of individuals exposed to ionizing radiation: a pilot study from Celaya, México.

INTRODUCTION: Occupational exposure to ionizing radiation can potentially lead to adverse health effects, including cancer and genetic defects. Genetic damage caused by radiation can be detected if micronuclei are observed. The objective of this pilot study was to detect the presence of micronuclei in cells of the oral mucosa in inidividuals occupationally exposed to ionizing radiation. METHODS: We implemented a pilot case-control study in which we compared oral mucosa micronuclei in 30 medical and nursing personnel in radiology centers in Celaya, Mexico, with 30 volunteers not exposed to ionizing radiation recruited from a public University. The oral mucosa was brushed and the amount of micronuclei was quantified. Chi-square test or t-test for two proportions were used to compared ionizing radiation and genetic damage between exposed and non-exposed groups. RESULTS: The exposed group had an average of 5.37 ± 3.49 micronuclei and the non-exposed had 0.37 ± 0.61 (P<0.01). In the exposed group, 90% of participants exhibited genetic damage compared to 6.67% in the unexposed group (P<0.05). CONCLUSION: In this pilot study, medical and nursing staff from radiology centers presented with higher genetic damage compared to control group. Further studies are needed to identify the prevalence of genetic damage due to occupational radiation exposure in Mexico.

Qualitative evaluation of ferritin in serum samples by Raman spectroscopy and principal component analysis.

Iron molecule is of great importance in the synthesis of hemoglobin which is essential for oxygen transport. Iron levels are quantified by accurately high sensitivity tests, such as serum ferritin (SF). However, common studies to quantify SF are long and strenuous (~ 5 h), for example enzyme-linked immunosorbent assay (ELISA). In this paper, blood serum samples were analyzed by Raman spectroscopy (RS), and a computational analysis of spectra is proposed to detect differences in SF as an alternative procedure. Serum samples were obtained from 22 patients, 9 who were clinically diagnosed with anemia and 13 controls. Patients with anemia had low levels of SF (< 30 ng/ml), and a control group had levels between 30 and 500 ng/ml. The spectra obtained were conditioned with a baseline correction and smoothing, then evaluated by principal component analysis (PCA), and a predictive model was estimated by lineal discrimination analysis (LDA). The results showed a clear differentiation of the study groups by PCA, also 99.69% sensitivity and 100% specificity by LDA. This study suggest that Raman spectroscopy is a fast (~ 5 min) and a powerful tool capable to qualitative differentiate ferritin concentrations.

Coronary artery segmentation in X-ray angiograms using gabor filters and differential evolution.

Segmentation of coronary arteries in X-ray angiograms represents an essential task for computer-aided diagnosis, since it can help cardiologists in diagnosing and monitoring vascular abnormalities. Due to the main disadvantages of the X-ray angiograms are the nonuniform illumination, and the weak contrast between blood vessels and image background, different vessel enhancement methods have been introduced. In this paper, a novel method for blood vessel enhancement based on Gabor filters tuned using the optimization strategy of Differential evolution (DE) is proposed. Because the Gabor filters are governed by three different parameters, the optimal selection of those parameters is highly desirable in order to maximize the vessel detection rate while reducing the computational cost of the training stage. To obtain the optimal set of parameters for the Gabor filters, the area (Az) under the receiver operating characteristics curve is used as objective function. In the experimental results, the proposed method achieves an Az=0.9388 in a training set of 40 images, and for a test set of 40 images it obtains the highest performance with an Az=0.9538 compared with six state-of-the-art vessel detection methods. Finally, the proposed method achieves an accuracy of 0.9423 for vessel segmentation using the test set. In addition, the experimental results have also shown that the proposed method can be highly suitable for clinical decision support in terms of computational time and vessel segmentation performance.

Validity and reliability of electroacoustic probe for diagnosis of developmental dysplasia of the hip.

BACKGROUND: Sound transmission is used in the diagnosis of hip dysplasia since the end of the 80's. Aim of this study is to quantify the validity and reliability of electroacoustic probe for the diagnosis of hip dysplasia in neonates. METHODS: Diagnostic study included neonates aged 4-28 days, whose parents signed an informed consent. The probe was used three times for comparative sound transmission and with extension/flexion; hip ultrasound was performed with Graf technique as gold standard. Kappa was determined for intraobserver and interobserver reliability; validity was calculated with sensitivity, specificity, and predictive values. RESULTS: 100 neonates were included. For the comparative sound transmission, 0.80 and 0.81 Kappa were obtained for the intraobserver and interobserver respectively; with extension/flexion, Kappa 0.98 and 0.95 were obtained for the intraobserver and interobserver respectively. With comparative sound transmission, 44.8%, 97.7%, 76.5% and 91.3% for sensitivity, specificity, positive and negative predictive values, respectively; with extension/flexion test, the sensitivity, specificity, positive and negative predictive values: 82.8%, 99.4%, 96.0%, and 97.1%, respectively. CONCLUSION: The electroacoustic probe is moderate valid and reliable for the diagnosis of developmental dysplasia of the hip. TRIAL REGISTRATION: Open Science framework https://osf.io/kpf5s/?view_only=0a9682c6w1c842ad8e1d9a66e8dcf038.

Mammalian cells exposed to ionizing radiation: Structural and biochemical aspects.

Acute or chronic exposure to ionizing radiation is a factor that may be hazardous to health. It has been reported that exposure to low doses of radiation (less than 50 mSv/year) and subsequently exposure to high doses produces greater effects in people. It has been reported that people who have been exposed to low doses of radiation (less than 50 mSv/year) and subsequently are exposed to high doses, have greater effects. However, at a molecular and biochemical level, it is an unknown alteration. This study, analyzes the susceptibility of a biological system (HeLa ATCC CCL-2 human cervix cancer cell line) to ionizing radiation (6 and 60 mSv/90 s). Our research considers multiple variables such as: total protein profile, mitochondrial metabolic activity (XTT assay), cell viability (Trypan blue exclusion assay), cytoskeleton (actin microfilaments), nuclei (DAPI), and genomic DNA. The results indicate, that cells exposed to ionizing radiation show structural alterations in nuclear phenotype and aneuploidy, further disruption in the tight junctions and consequently on the distribution of actin microfilaments. Similar alterations were observed in cells treated with a genotoxic agent (200 µM H2O2/1h). In conclusion, this multi-criteria assessment enables precise comparisons of the effects of radiation between various line cells. However, it is necessary to determine stress markers for integration of the effects of ionizing radiation.

Cr localization and speciation in roots of chromate fed Helianthus annuus L. seedlings using synchrotron techniques.

In order to gain knowledge on the potential use of Helianthus annuus L. for the remediation of Cr(VI) polluted waters, hydroponics experiments were set up to determine Cr uptake and tolerance in different Cr(VI)-sulfate conditions, and Cr biotransformations. Results indicated that Cr(VI) promoted seed germination, and plant tolerance was higher at younger plant stages. Cr uptake was dependent on sulfate concentrations. The highest Cr levels in roots and shoots (13,700 and 2,500 mg kg(-1) dry weight (DW), respectively) were obtained in 1 mM sulfate. The lowest Cr uptake in roots (10,600 mg kg(-1) DW) was observed in seedlings treated with no sulfate. In shoots, Cr concentration was of 1,500 mg kg(-1)DW for the 1 mM sulfate treatment, indicating a different level of interaction between chromate and sulfate in both tissues. For the first time, using micro X-ray florescence (muXRF), we demonstrated Cr reaches the root stele and is located in the walls of xylem vessels. Bulk and micro X-ray Absorption Near-Edge Structure (muXANES) results showed that Cr in the roots is mostly in the form of Cr(III) phosphate (80%), with the remainder complexed to organic acids. Our results suggest this plant species may serve for Cr(VI) rhizofiltration purposes.

Biomagnetic techniques for evaluating gastric emptying, peristaltic contraction and transit time.

Biomagnetic techniques were used to measure motility in various parts of the gastrointestinal (GI) tract, particularly a new technique for detecting magnetic markers and tracers. A coil was used to enhance the signal from a magnetic tracer in the GI tract and the signal was detected using a fluxgate magnetometer or a magnetoresistor in an unshielded room. Estimates of esophageal transit time were affected by the position of the subject. The reproducibility of estimates derived using the new biomagnetic technique was greater than 85% and it yielded estimates similar to those obtained using scintigraphy. This technique is suitable for studying the effect of emotional state on GI physiology and for measuring GI transit time. The biomagnetic technique can be used to evaluate digesta transit time in the esophagus, stomach and colon, peristaltic frequency and gastric emptying and is easy to use in the hospital setting.

Stress profile, coping style, anxiety, depression, and gastric emptying as predictors of functional dyspepsia: a case-control study.

OBJECTIVE: To determine whether gastric emptying, stomach peristaltic frequencies, stress profile, depressive symptoms, anxiety, and salivary cortisol levels could predict functional dyspepsia (FD). METHODS: Magnetogastrography (MGG) was used to measure gastric emptying time and the gastric peristaltic frequencies in 15 patients with FD diagnosis and in 17 healthy volunteers. In all the participants, stress profile, anxiety, and depressive symptoms were evaluated by means of standardized questionnaires, and morning salivary samples were collected for the measurement of cortisol levels. A univariate logistic regression model was used to examine the probability of the measured variables to predict the presence of FD. RESULTS: The univariate logistic regression model showed that the half-time of gastric emptying (OR=1.16 P=.01); the subscale of stress items (OR=1.08, P=.003); negative appraisal of subscale coping strategies (OR=1.03, P=0.007); anxiety (OR=1.05, P=.01); and depression (OR=1.23, P=.02) had a significant predictive value for the presence of FD. However, by applying the stricter multiple comparison criteria, only stress, negative appraisal, and anxiety arose as predictors of FD. The FD patients compared with healthy volunteers showed significantly elevated half-time of gastric emptying (P<.0006), high scores in the subscales of stress (P<.000003), in behavior type "A" (P<.04), in coping styles (P<.008), in depression (P<.0004), and in anxiety (P<.0002). CONCLUSIONS: These findings indicate that psychosocial stress, mood symptoms, and coping style are predictors of FD. The stress shows high sensibility and specificity in the patients with FD, indicating a contribution in the etiopathogenesis of dyspepsia.

Effects of metoclopramide on gastric motility measured by short-term bio-impedance.

AIM: To analyze the accuracy of short-term bio-impedance as a means of measuring gastric motility. METHODS: We evaluated differences in the short-term electrical bio-impedance signal from the gastric region in the following conditions: (1) fasting state, (2) after the administration of metoclopramide (a drug that induces an increase in gastric motility) and (3) after food ingestion in 23 healthy volunteers. We recorded the real component of the electrical impedance signal from the gastric region for 1000 s. We performed a Fast Fourier Transform (FFT) on this data and then compared the signal among the fasting, medicated, and postprandial conditions using the median of the area under the curve, the relative area under the curve and the main peak activity. RESULTS: The median of the area under the curve of the frequency range in the region between 2-8 cycles per minute (cpm) decreased from 4.7 cpm in the fasting condition to 4.0 cpm in the medicated state (t = 3.32, P = 0.004). This concurred with the decrease seen in the relative area under the FFT curve in the region from 4 to 8 cpm from 38.3% to 26.6% (t = 2.81, P = 0.012) and the increase in area in the region from 2 to 4 cpm from 22.4% to 27.7%, respectively (t = -2.5, P = 0.022). Finally the main peak position also decreased in the region from 2 to 8 cpm. Main peak activity in the fasting state was 4.72 cpm and declined to 3.45 cpm in the medicated state (t = 2.47, P = 0.025). There was a decrease from the fasting state to the postprandial state at 3.02 cpm (t = 4.0, P = 0.0013). CONCLUSION: Short-term electrical bio-impedance can assess gastric motility changes in individuals experiencing gastric stress by analyzing the area medians and relative areas under the FFT curve.

Effects of anatomical position on esophageal transit time: a biomagnetic diagnostic technique.

AIM: To study the esophageal transit time (ETT) and compare its mean value among three anatomical inclinations of the body; and to analyze the correlation of ETT to body mass index (BMI). METHODS: A biomagnetic technique was implemented to perform this study: (1) The transit time of a magnetic marker (MM) through the esophagus was measured using two fluxgate sensors placed over the chest of 14 healthy subjects; (2) the ETT was assessed in three anatomical positions (at upright, fowler, and supine positions; 90 degrees , 45 degrees and 0 degrees , respectively). RESULTS: ANOVA and Tuckey post-hoc tests demonstrated significant differences between ETT mean of the different positions. The ETT means were 5.2 +/- 1.1 s, 6.1 +/- 1.5 s, and 23.6 +/- 9.2 s for 90 degrees , 45 degrees and 0 degrees , respectively. Pearson correlation results were r = -0.716 and P < 0.001 by subjects' anatomical position, and r = -0.024 and P > 0.05 according the subject's BMI. CONCLUSION: We demonstrated that using this biomagnetic technique, it is possible to measure the ETT and the effects of the anatomical position on the ETT.

Gender difference in the gastric emptying measured by magnetogastrography using a semi-solid test meal.

BACKGROUND/AIMS: evidence of gender-related differences in gastric emptying have been reported in the literature. Usually, those researches have focusing only with solid or liquid meal and invasive techniques. The objective of this study was to know the differences in the half time of gastric emptying and frequency of peristaltic contractions measured with magnetogastrography (MGG) on healthy subjects, using a semi-solid test meal. METHODS: the study was carried out in 16 healthy subjects without gastrointestinal disease history they were divided in two groups, 8 male and 8 female. A test meal composed by 250 ml of yogurt and 3 grs of magnetite (Fe3O4), was employed. RESULTS: the gastric emptying half times were found to be 32.3 +/- 10.8 and 36.0 +/- 6.7 minutes, for men and women, respectively. Magnetogastrography modality presented in this study is a useful technique to measure the gastric emptying and the peristaltic contractions frequency. The studies were performed in healthy subjects without side effects. Using this technique a significant statistical difference (p<0.05) on gastric emptying from healthy volunteers was obtained between men and women. CONCLUSIONS: a contribution of this study was to demonstrate the feasibility of magnetogastrography to analyze gender differences in the gastric emptying half time using a semi-solid test meal.

Biomagnetic investigation of injury currents in rabbit intestinal smooth muscle during mesenteric ischemia and reperfusion.

A noninvasive, sensitive, and specific method of detecting mesenteric ischemia would be of great use in reducing the morbidity and mortality with which it is associated. Acute lesions in polarized electrically coupled tissues lead to injury currents driven by the transmembrane resting potential gradient. These injury currents are an effective indicator of pathophysiology. The presence of near-DC injury currents in rabbit intestinal smooth muscle has already been demonstrated using a Superconducting quantum interference device (SQUID), and the aim of this study was to evaluate the effect of arterial reperfusion upon these currents. We exteriorized the small bowel of 14 New Zealand white rabbits and placed a remotely operated vascular occluder around the distal most artery supplying a 3-in segment of the jejunum. Experiments were conducted in three groups, i.e., control (n=3), ischemia (n=6), and reperfusion following ischemia (n=5). The subject's position was modulated in and out of the biological field detection range of a SQUID magnetometer using a lift constructed of nonmagnetic material. The changes in magnetic field amplitude were 9.3 and 31.01% for the control and ischemia groups, respectively. The reperfusion group first exhibited a decrease of 17.35% from the pre-ischemic to the ischemic period, followed by an increase of 13.88% of the ischemic value after reestablishing perfusion. In conclusion, injury currents in GI smooth muscle that appear during ischemia are reduced to near-pre-ischemic levels during reperfusion.