Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Polymers (Basel) ; 16(13)2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-39000635

RESUMEN

Ionizing radiation is vital in various fields but poses health risks, necessitating effective shielding. This study investigated the photon-shielding properties of polyester-based ternary composites with barite (BaSO4) and tungsten (W) using experimental methods, theoretical calculations, and Monte Carlo simulations for energies between 81 keV and 1332.5 keV. WINXCOM was utilized for the theoretical predictions, and the MCNP6 and PHITS 3.22 algorithms were employed for the simulations. According to the results, the simulation, theoretical, and experimental data all closely aligned. At 81 keV, the composite containing the highest amount of tungsten (PBaW50) had the highest mass attenuation coefficient (3.7498 cm2/g) and linear attenuation coefficient (12.9676 cm-1). Furthermore, for a sample that was 1 cm thick, PBaW50 offered 99.88% protection at 81 keV and had the lowest HVL and TVL values. PBaW50 exhibited attenuation capabilities, making it appropriate for use in industrial, medical, and aerospace settings. In summary, the findings of this study underscore the potential of polyester-based composites doped with barite and tungsten as effective materials for gamma radiation shielding. The PBaW50 sample, in particular, stands out for its attenuation performance, making it a viable option for a wide range of applications where durable and efficient radiation shielding is essential.

2.
Am J Audiol ; 33(3): 863-873, 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-38917152

RESUMEN

PURPOSE: Cauliflower ear in wrestlers can lead to hearing impairment. This study primarily aims to assess the hearing of wrestlers with bilateral cauliflower ears and determine their external ear canal (EEC) resonance frequencies. Our second aim is to evaluate their hearing quality, speech, and spatial perception. METHOD: This study included 28 male wrestlers aged 18-35 years with bilateral cauliflower ears, as well as 27 male participants in the control group with no wrestling history. The participants' hearing thresholds were determined across the frequency range of 125-16000 Hz for air-conduction and 500-4000 Hz for bone conduction. EEC resonance frequencies were measured. Additionally, all participants completed the Turkish version of the Speech, Spatial, and Qualities of Hearing Scale (SSQ) questionnaire. RESULTS: Wrestlers with cauliflower ears exhibited significantly higher hearing thresholds, particularly at frequencies above 4000 Hz (p < .05). Analysis of EEC resonance showed a shift to higher frequencies in the second resonance peak of the right ear (p < .001) and the first resonance peak of the left ear (p = .045). SSQ scores revealed that wrestlers had higher spatial perception (p = .046), hearing quality (p = .004), and general scores (p = .042) in comparison to the control group. CONCLUSIONS: Blunt traumas in wrestlers, leading to cauliflower ear, can result in hearing loss. Moreover, deformities in the external ear affect the resonance frequencies of the EEC. Therefore, it is crucial to advocate for the use of ear protection equipment among wrestlers. When fitting hearing aids, attention should be given to changes in the EEC resonance frequency.


Asunto(s)
Lucha , Humanos , Masculino , Adulto Joven , Adolescente , Adulto , Estudios de Casos y Controles , Umbral Auditivo , Oído Externo/anomalías , Conducción Ósea/fisiología , Pérdida Auditiva/fisiopatología , Percepción del Habla/fisiología
3.
Appl Radiat Isot ; 208: 111296, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38508065

RESUMEN

This study aimed to investigate the effect of diabetes on radiation attenuation parameters of the femur and tibia of rats using Monte Carlo Simulations. First, control and diabetic rats were identified and tibias and femurs were removed. Then, the elemental ratios of the bones obtained were calculated using EDS (Energy Dissipative X-ray Spectroscopy). Therefore, radiation permeability properties of control and diabetic bones were simulated by using the content ratios in the bones in MCNP6 (Monte Carlo N-Particle) and PHITS (Particle and Heavy Ion Transport code System) 3.22 and Stopping and Range of Ions in Matter (SRIM) simulation codes. Attenuation coefficient results were compared with the NIST database via XCOM. Although differences in absorption coefficients are observed at low energies, these differences disappear as the energy increases.


Asunto(s)
Diabetes Mellitus Experimental , Tibia , Ratas , Animales , Tibia/diagnóstico por imagen , Proyectos Piloto , Simulación por Computador , Fémur/diagnóstico por imagen , Método de Montecarlo
4.
Appl Radiat Isot ; 204: 111115, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38006780

RESUMEN

In recent developments, artificial neural networks (ANNs) have demonstrated their capability to predict reaction cross-sections based on experimental data. Specifically, for predicting (α,n) reaction cross-sections, we meticulously fine-tuned the neural network's performance by optimizing its parameters through the Levenberg-Marquardt algorithm. The effectiveness of this approach is corroborated by notable correlation coefficients; an R-value of 0.90928 for overall correlation, 0.98194 for validation, 0.99981 for testing, and 0.94116 for the comprehensive network prediction. We conducted a rigorous comparison between the results and theoretical computations derived from the TALYS 1.95 nuclear code to validate the predictive accuracy. The mean square error value for artificial neural network results is 7620.92, whereas for TALYS 1.95 calculations, it has been found to be 50,312.74. This comprehensive evaluation process validates the reliability of the ANN based on the Levenberg-Marquardt algorithm in approximating the reaction sections, thus demonstrating its potential for comprehensive investigations. These recent developments confirm the feasibility of using ANN models to gain insight into (α,n) reaction cross-sections.

5.
Appl Radiat Isot ; 199: 110922, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37413712

RESUMEN

This study is concerned with the calculations of double differential neutron cross-sections of the structural fusion materials of 56Fe and 90Zr isotopes that are bombarded with protons. Calculations were performed using the level density models of the TALYS 1.95 code and PHITS 3.22 Monte Carlo code. Constant Temperature Fermi Gas, Back Shifted Fermi Gas, and Generalized Super Fluid Models were employed for level density models. Calculations were performed at 22.2 MeV proton energies. Calculations were compared with the experimental data taken from Experimental Nuclear Reaction Data (EXFOR). In conclusion, the results showed that the level density model results of TALYS 1.95 codes for the double differential neutron cross-sections of 56Fe and 90Zr isotopes are consistent with experimental data. On the other hand, PHITS 3.22 results gave lower cross-section values than experimental data at 120 and 150°.

6.
Clin Otolaryngol ; 48(4): 623-629, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36973223

RESUMEN

OBJECTIVE: The present study aimed to investigate the in vivo activity of nasal irrigation (NI) with saline, NI with povidone-iodine (PVP-I) 1%, NI with a mix of hypertonic alkaline and PVP-I 1% against Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). DESIGN: This study was a prospective randomised clinical trial. SETTING: A multicenter study involving tertiary care centres. PARTICIPANTS: The study included adult outpatients whose qualitative SARS-CoV-2 RT-PCR tests in nasopharyngeal swabs were positive. One hundred twenty patients were divided into four equal groups. Standard COVID-19 treatment was given to Group 1, NI containing saline was added to patients' treatment in Group 2, NI containing 1% PVP-I solution was added to patients' treatment in Group 3, and NI containing 1% PVP-I solution and the hypertonic alkaline solution was added to patients' treatment in Group 4. MAIN OUTCOME MEASURES: On the first day of diagnosis (Day 0), nasopharyngeal swab samples were taken, on the third and fifth days the nasopharyngeal viral load (NVL) reduction in quantitative RT-PCR test was calculated. RESULTS: Between the zeroth to third days and zeroth to fifth days, the NVL reduction was significant in all groups (p < .05). In paired comparisons of groups, the NVL decrease in Group 4 in the first 3 days was significantly lower than all groups (p < .05). The NVL decrease in Groups 3 and 4 in the first 5 days were significantly lower than Group 1 (p < .05). CONCLUSION: This study revealed that the use of NI of 1% PVP-I and the hypertonic alkaline solution mixture was more effective in reducing NVL.


Asunto(s)
COVID-19 , Povidona Yodada , Adulto , Humanos , Povidona Yodada/uso terapéutico , SARS-CoV-2 , Carga Viral , Tratamiento Farmacológico de COVID-19 , Estudios Prospectivos , Lavado Nasal (Proceso) , Cloruro de Sodio
7.
Appl Radiat Isot ; 192: 110609, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36508959

RESUMEN

Prediction of neutron-induced reaction cross-sections at around the 14.5 MeV neutron energy is crucial to calculate nuclear transmutation rates, nuclear heating, and radiation damage from gas formation in fusion reactor technology In this research, the new approach of (n,α) reaction cross-section is presented. It has been assessed by utilizing the artificial neural network (ANN) when compared to more advanced algorithms, the Levenberg-Marquardt algorithm-based ANN can be exceedingly fast. The correlation coefficients for a training R-value of 0.99283, a validation R-value of 0.991190, a testing R-value of 0.97337, and an overall R-value of 0.98515 demonstrate that Levenberg-Marquardt algorithm-based ANN is well suited for this purpose. . The obtained results were compared to theoretical calculations of TALYS 1.95 nuclear code. As a consequence, it has been demonstrated that the ANN model can be used to determine the systemic study for (n, α) reaction cross-sections.


Asunto(s)
Algoritmos , Redes Neurales de la Computación
8.
Ear Nose Throat J ; 102(2): 96-100, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33459561

RESUMEN

OBJECTIVE: Sinonasal inverted papillomas are benign neoplasms of the nasal cavity and paranasal sinuses. They have characteristic features such as a high risk of recurrence and possible malignant transformation. This study was conducted to investigate the relationship between sinonasal inverted papilloma and inflammatory blood markers. PATIENTS AND METHODS: Sixty-five patients who were diagnosed histologically as having sinonasal inverted papilloma and 65 age- and sex-matched healthy controls were included in the study. Inflammatory blood markers such as neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), red cell distribution width (RDW), mean platelet volume (MPV), and platelet distribution width (PDW) of the patient and control groups were compared. RESULTS: There were no statistically significant differences between the patients and controls for white blood cell, platelet, hemoglobin, neutrophil, and lymphocyte counts (P > .05). No statistically significant difference was found between the patients and controls for NLR, PLR, RDW, MPV, and PDW (P > .05). In the logistic regression analysis model, which was created to investigate the effects of inflammatory blood markers in determining the patient group, the increase in the NLR and decrease in the PLR were found to be statistically significant factors (P = .008, P = .039). CONCLUSION: This is the first study in the literature to investigate the relationship between sinonasal inverted papilloma and inflammatory blood markers, and the results suggest that NLR and PLR may be used to distinguish patients with sinonasal inverted papilloma from controls.


Asunto(s)
Neoplasias de Cabeza y Cuello , Papiloma Invertido , Neoplasias del Sistema Respiratorio , Humanos , Biomarcadores , Volúmen Plaquetario Medio , Índices de Eritrocitos , Linfocitos , Estudios Retrospectivos
9.
J Voice ; 37(2): 275-281, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33483224

RESUMEN

BACKGROUND: The aim of the study was comparing the diagnostic role of the white light (WL) endoscopy, video laryngostroboscopy (VLS), and narrow-band imaging (NBI) in the evaluation of the benign vocal fold lesions. MATERIAL AND METHODS: From March 2018 to June 2019, a total of 118 cases were enrolled in this study. Ninety-eight patients were suspected with vocal fold nodules, cysts, polyps, and sulcus vocalis and 20 patients without a history of dysphonia. Each patient was examined by WL, VLS, and NBI endoscopy. Recorded images and videos were analyzed and scored by three otorhinolaryngologists who had at least 3 years of experience in phoniatrics field. The evaluation results were compared between the methods and the physicians. RESULTS: A total of 118 cases were grouped by their confirmed diagnosis, vocal fold nodules (n = 28), vocal fold cyst (n = 24), vocal fold polyp (n = 9), and sulcus vocalis (n = 37). When the correct diagnosis rates of the physicians were compared, the statistical significance was found between the physicians in the WL and VLS method (P= 0.014, P= 0.027). No statistically significant difference was found among physicians in NBI method (P = 0.368). The difference between the diagnostic methods was found to be statistically significant in reaching the accurate diagnosis for benign vocal fold lesions (P< 0.001). While the difference between NBI-WL and VLS-WL was statistically significant (P< 0.001 and P< 0.001). The difference between NBI-VLS was not statistically significant while evaluating the vocal fold nodules, cysts, and sulcus vocalis separately (P= 0.102, P = 0.026, P = 0.157). Otherwise, it was statistically significant (P= 0.002) while evaluating total benign lesions in the study. The difference between NBI-VLS combination and VLS, NBI-VLS combination and VLS-WL combination were statistically significant (P< 0.001 and P= 0.001). CONCLUSION: This study showed that NBI assessments have similar accuracy and sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) to VLS and have a higher value than WL endoscopy in reaching the diagnosis for benign vocal fold lesions. Therefore, NBI can be accepted as a promising approach to identify benign laryngeal lesions due to its optical properties.


Asunto(s)
Quistes , Enfermedades de la Laringe , Pólipos , Humanos , Laringoscopía , Pliegues Vocales/patología , Imagen de Banda Estrecha/métodos , Enfermedades de la Laringe/patología , Músculos Laríngeos , Quistes/patología , Pólipos/patología , Sensibilidad y Especificidad
10.
J Biol Phys ; 48(4): 461-475, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36372807

RESUMEN

Experiments using conventional experimental approaches to capture the dynamics of ion channels are not always feasible, and even when possible and feasible, some can be time-consuming. In this work, the ionic current-time dynamics during cardiac action potentials (APs) are predicted from a single AP waveform by means of artificial neural networks (ANNs). The data collection is accomplished by the use of a single-cell model to run electrophysiological simulations in order to identify ionic currents based on fluctuations in ion channel conductance. The relevant ionic currents, as well as the corresponding cardiac AP, are then calculated and fed into the ANN algorithm, which predicts the desired currents solely based on the AP curve. The validity of the proposed methodology for the Bayesian approach is demonstrated by the R (validation) scores obtained from training data, test data, and the entire data set. The Bayesian regularization's (BR) strength and dependability are further supported by error values and the regression presentations, all of which are positive indicators. As a result of the high convergence between the simulated currents and the currents generated by including the efficacy of a developed Bayesian solver, it is possible to generate behavior of ionic currents during time for the desired AP waveform for any electrical excitable cell.


Asunto(s)
Potenciales de Acción , Proyectos Piloto , Teorema de Bayes
11.
Laryngoscope Investig Otolaryngol ; 6(6): 1240-1247, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34909468

RESUMEN

Objective: The causative agent of COVID-19 is a novel member of coronaviridaes, SARS-CoV-2. It has been reported that the spike (S) protein of SARS-CoV-2 is responsible of infectivity. The S protein is demonstrated to be inactivated under environmental condition, such as hypertonicity and alkaline pH. The aim of the study was to investigate the effect of hypertonic alkaline nasal irrigation (HANI) on SARS-CoV-2. Methods: Sixty patients divided into two groups. The patients in Group 1 used hydroxychloroquine (HCQ), and the patients in Group 2 used HCQ and HANI. Nasopharyngeal samples were collected at the beginning, on 3rd and 7th day of the PCR test positivity. The nasopharyngeal viral load (NVL) changes analyzed with quantitative PCR. Results: NVL decrease in weekly period was statistically significant for both groups, when the difference between NVL day 0 and 3rd in Group 1 and NVL difference between day 0 and 3rd in Group 2 were compared. The difference between Groups 1 and 2 in terms of NVL change was statistically significant (P < 0.05). Conclusion: We demonstrated a significant decrease in nasopharyngeal SARS-CoV-2 load with HANI solution and suggest that HANI may be promising modality for the COVID-19 treatment. Level of evidence: IB.

12.
An Acad Bras Cienc ; 93(suppl 3): e20201664, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34550202

RESUMEN

Exogenous SO2 is toxic especially to the pulmonary and cardiovascular system, similar to nitric-oxide, carbon-monoxide, and hydrogen-sulfide. Endogenous SO2 is produced in many cell types. The SO2 content of the rat heart has been observed to substantially decrease during isoproterenol-induced hypertrophy. This study sought to determine whether an SO2 derivative could inhibit the prolongation of action potentials during the isoproterenol-induced hypertrophy of rat cardiomyocytes and explore the ionic currents. Alongside electrocardiogram recordings, the voltage and current-clamped measurements were conducted in the enzymatically isolated left ventricular cardiomyocytes of Wistar rats. The consistency of the results was evaluated by the novel mathematical electrophysiology model. Our results show that SO2 significantly blocked the prolongation of QT-interval and action potential duration. Furthermore, SO2 did not substantially affect the Na+ currents and did not improve the decreased steady-state and transient outward K+ currents, but it reverted the reduced L-type Ca2+ currents (I CaL) to the physiological levels. Altered inactivation of I CaL was remarkably recovered by SO2. Interestingly, SO2 significantly increased the Ca2+ transients in hypertrophic rat hearts. Our mathematical model also confirmed the mechanism of the SO2 effect. Our findings suggest that the shortening mechanism of SO2 is related to the Ca2+ dependent inactivation kinetics of the Ca2+ current.


Asunto(s)
Miocitos Cardíacos , Dióxido de Azufre , Potenciales de Acción , Animales , Hipertrofia , Isoproterenol/toxicidad , Ratas , Ratas Wistar , Dióxido de Azufre/toxicidad
13.
Appl Radiat Isot ; 169: 109581, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33423020

RESUMEN

In this study; Giant Dipole Resonance (GDR) parameters of the spherical nucleus have been estimated by using artificial neural network (ANN) algorithms. The ANN training has been carried out with the Levenberg-Marquardt feed-forward algorithm in order to provide fast convergence and stability in ANN training and experimental data, taken from Reference Input Parameter Library (RIPL). R values of the system have been found as 0.99636, 0.94649, and 0.98318 for resonance energy, full width half maximum, and resonance cross-section, respectively. Obtained results have been compared with the GDR parameters which are taken from the literature. To validate our findings, newly acquired GDR parameters were then replaced with the existing GDR parameters in the TALYS 1.95 code and 142-146Nd(γ,n)141-145Nd reaction cross-sections have been calculated and compared with the experimental data taken from the literature. As a result of the study, it has been shown that ANN algorithms can be used to calculate the GDR parameters in the absence of the experimental data.

14.
Appl Radiat Isot ; 169: 109583, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33434776

RESUMEN

The main aim of this study is to develop accurate artificial neural network (ANN) algorithms to estimate level density parameters. An efficient Bayesian-based algorithm is presented for classification algorithms. Unknown model parameters are estimated using the observed data, from which the Bayesian-based algorithm is predicted. This paper focuses on the Bayesian method for parameter estimations of Gilbert Cameron Model (GCM), Back Shifted Fermi Gas Model (BSFGM) and Generalised Super Fluid Model (GSM), which are known as the phonemological level density models. Obtained level density parameters have been compared with the Reference Input Parameter Library for Calculation of Nuclear Reactions and Nuclear Data Evaluations (RIPL) data. R values of the Bayesian method have been found as 0.9946, 0.9981 and 0.9824 for BSFGM, GCM and GSM, respectively. In order to validate our results, default level density parameters of TALYS 1.95 code have been changed with our newly obtained results and photo-neutron cross-section calculations of the 117Sn(γ,n)116Sn, 118Sn(γ,n)117Sn, 119Sn(γ,n)118Sn and 120Sn(γ,n)119Sn reactions have been calculated by using these newly obtained level density parameters.

15.
Appl Radiat Isot ; 170: 109584, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33445056

RESUMEN

The aim of this study is to develop an accurate artificial neural network algorithm for the cross-section of (n,p) reactions at 14.5 ∓0.5 MeV neutron energy which is important to developing materials for fusion reactor design. The experimental data used at artificial Neural network calculations have been taken from the Experimental Nuclear Reaction Data (EXFOR) database. Bayesian algorithm has been used at training section of artificial neural network. Regression (R) values of artificial neural network calculations have been found as 0.99363, 0.98574 and 0.99257 for training, testing and all process respectively. In addition to artificial neural network calculations, TALYS 1.95 nuclear reaction code has been used to reproduce (n,p) reactions at 14.5 ∓0.5 MeV. Two-component exciton model and Constant Temperature Fermi Gas Model have been used as pre-equilibrium and level density models respectively. Mean square errors of our calculations have been found 48.51 and 495.06 for artificial neural network and TALYS 1.95 respectively. Artificial Neural network estimations have been compared and analyzed with the TALYS 1.95 calculations and the experimental data taken from EXFOR database.

16.
Fish Physiol Biochem ; 46(4): 1199-1205, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32385720

RESUMEN

This study was conducted to determine if diets supplemented with turmeric powder (Curcuma longa) affected the reversible sterilization of Pseudotropheus socolofi. Three experimental diets were formulated to contain 0%, 10%, and 14% turmeric powder. The fish (mean weight 13 g) were randomly divided into groups consisting of 1 male and 4 females for each aquarium and were kept together for 137 days. The control group was fed a diet without turmeric, while the others were fed diets with turmeric for the first 75 days. All groups were then fed the control diet from day 75 to 137. The results showed that turmeric powder supplementation did not affect growth performance (p Ëƒ 0.05). A histopathological examination of the ovaries, performed on two samples on days 75 and 137, revealed that high doses of turmeric decreased number of ovulated vitellogenic follicles and ovarian activity. Moreover, immature follicle density was excessive in groups fed turmeric powder. However, the number of ovulated vitellogenic follicles increased in groups fed diets containing 10% and 14% turmeric after feeding them with the turmeric-free control diet from day 75 to 137. In conclusion, the study revealed that supplementing diets with high ratios of turmeric can influence ovarian activity; however, these effects can be reversed by ceasing supplementation.


Asunto(s)
Cíclidos/fisiología , Curcuma/química , Curcumina/toxicidad , Análisis de Varianza , Alimentación Animal , Animales , Peso Corporal/efectos de los fármacos , Cíclidos/crecimiento & desarrollo , Curcumina/administración & dosificación , Femenino , Hepatopáncreas/efectos de los fármacos , Masculino , Ovario/efectos de los fármacos , Esterilización Reproductiva/métodos , Esterilización Reproductiva/veterinaria
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...