WEBSITE QUALITY ASSESSMENT. A CASE STUDY OF GSM HOSTING FORUM

The ever-growing amount of data on mobile phones, tablets, and smart electronic devices on the Internet and the need to use this data to address problems highlight the importance of the evaluation and validation of data-sharing websites. The GSMHOSTING website plays a key role in communicating and providing services to its users in terms of repairing mobile phones and smart electronic devices. The purpose of this study was to determine its quality from the perspective of mobile phone repair technicians. These technicians were 100 people from Birjand in South Khorasan province (Iran) who used GSMHOSTING website as a reference. The website quality assessment study was conducted in the summer of 2020. The study applied a descriptive survey and cross-sectional method based on a questionnaire. The questionnaire included 11 website dimensions: Routing, Information, Delivery, Apparent Features, Security, Reputation, Society, Entertainment, Provided goods and services, Reliability, Trust. Scores were given on a Likert scale. The validity of the questionnaire was determined using the opinions of web experts. The SPSS software and descriptive and inferential statistics methods were used to analyze data. The results indicated that the average quality of this website was acceptable in terms of technicians’ goals.  Addressing problems highlighted some of the website dimensions that will increase the overall quality of the website to support technicians in their activities

The Ability of Ultrasonic Characterization to Extract the Dose Distribution of MAGIC-f Polymer Gel

Background & Aims: Today, different imaging techniques have been studied in the reading of radiationsensitive polymer gels dosage. Due to limitations of imaging techniques such as magnetic resonance imaging (MRI) and computed tomography (CT), ultrasound techniques are proposed for dose-dependent parameter extraction. In this study, using MAGIC-f (methacrylic and ascorbic acid in gelatin initiated by copper with added formaldehyde) polymer gel and megavoltage radiation energy, the dose-dependent parameters of speed of sound and broadband ultrasonic attenuation (BUA) were evaluated. Methods: MAGIC-f polymer gel was irradiated with 1.25 MeV of Cobalt-60 and received a uniform dose in the range of 0 to 60 Gy in 2 Gy steps (2% accuracy). After calibration of ultrasound system with 500 kHz frequency, the parameters of speed of sound and BUA coefficient of exposed polymer gel samples were measured. Based on the dose-response curve, the ability of the ultrasound parameters in reading the absorbed dose was investigated. To evaluate the reasonable time interval with the most sensitive reading of the ultrasound method, samples were studied 3, 24, 36, and 48 hours after irradiation. To study the temperature readings, the gel samples irradiated at 5, 15, and 25 °C were studied. Results: The relationship of variation of speed of sound and attenuation coefficient and quality index (QI) with absorbed dose 3, 24, 36, and 48 hours after irradiation of gels are shown with a fourth-order polynomial fit. The results show that ultrasonic parameters have higher sensitivity 24 hours after irradiation. The sensitivity of dose-speed of sound and attenuation curve were 50 cm/s and 0.06 dB/MHz/Gy based on each Gy in the linear range of 4-44 Gy. Ultrasonic parameters were measured in the gel samples at 5, 15, and 25 ºC after 0-60 Gy irradiation in 2 Gy steps to determine the sensitivity of the ultrasonic properties to temperature. The measurements show that readings at 25 °C have a higher sensitivity than that at 5 and 15 °C. Thus, with an increase of 20 °C, the speed of sound increased 28 and 66 m/s before irradiation and with 60 Gy absorbed dose, respectively. Moreover, the attenuation coefficient decreased 2.50 dB/MHz before irradiation and increased 2.70 dB/MHz with 60 Gy absorbed dose. Conclusion: Acoustic properties of MAGIC-f gel, determined by measurements of speed of sound and ultrasonic broadband attenuation, indicate the ability of this technique in reading of absorbed dose. Maximum sensitivity of reading time and temperature of MAGIC-f gel were 24 hours after irradiation and 25 °C, respectivel

Determine the Dose Distribution Using Ultrasound Parameters in MAGIC-f Polymer Gels

In this study, using methacrylic and ascorbic acid in gelatin initiated by copper (MAGIC-f) polymer gel after megavoltage energy exposure, the sensitivity of the ultrasound velocity and attenuation coefficient dose-dependent parameters was evaluated. The MAGIC-f polymer gel was irradiated under 1.25 MeV cobalt-60, ranging from 0 to 60 Gy in 2-Gy steps, and received dose uniformity and accuracy of +2%. After calibration of the ultrasonic systems with a frequency of 500 kHz, the parameters of ultrasound velocity and attenuation coefficient of the irradiated gel samples were measured. According to the dose–response curve, the ability of ultrasonic parameters was evaluated in dose rate readings. Based on a 4-order polynomial curve, fitted on the dose–response parameters of ultrasound velocity and attenuation coefficient and observed at 24 hours after irradiation, ultrasonic parameters had more sensitivity. The sensitivity of the dose–velocity and dose-attenuation coefficient curves was observed as 50 m/s/Gy and 0.06 dB/MHz/Gy over the linear range of 4 to 44 Gy, respectively. The ultrasonic parameters at 5C, 15C, and 25C on the gel dosimeter after 0 to 60 Gy irradiation showed that readings at 25C have higher sensitivity compared to 15C and 5C. Maximum sensitivity time and temperature readings of the MAGIC-f ultrasonic parameters were concluded 24 hours after irradiation and at a temperature of 25C. Keyw

Clinical and pharmacological applications of silymarin components at cellular and molecular level: A review

Silymarin, a flavonolignan from ‘milk thistle’ (Silybum marianum) plant is used almost exclusively for hepatoprotection and amounts to 180 million US dollars business in Germany alone. In this review, we discuss about its safety, efficacy and future uses in liver diseases. The use of silymarin may replace the polyherbal formulations and will avoid the major problems of standardization, quality control and contamination with heavy metals or bacterial toxins. Silymarin consists of four flavonolignan isomers namely; silybin, isosilybin, silydianin and silychristin. Among them, silybin being the most active and commonly used. Silymarin is orally absorbed and is excreted mainly through bile as sulphates and conjugates. Silymarin offers good protection in various toxic models of experimental liver diseases in laboratory animals. It acts by antioxidative, anti-lipid peroxidative, antifibrotic, anti-inflammatory, membrane stabilizing, immunomodulatory and liver regenerating mechanisms. Silymarin has clinical applications in alcoholic liver diseases, liver cirrhosis, Amanita mushroom poisoning, viral hepatitis, toxic and drug induced liver diseases and in diabetic patients. Though silymarin does not have antiviral properties against hepatitis virus, it promotes protein synthesis, helps in regenerating liver tissue, controls inflammation, enhances glucuronidation and protects against glutathione depletion. Silymarin may prove to be a useful drug for hepatoprotection in hepatobiliary diseases and in hepatotoxicity due to drugs. The non-traditional use of silymarin may make a breakthrough as a new approach to protect other organs in addition to liver. As it is having a good safety profile, better patient tolerability and an effective drug at an affordable price in near future new derivatives or new combinations of this drug may prove to be useful. © Medwell Journals, 2016

Chitosan Preparation from Persian Gulf Shrimp Shells and Investigating the Effect of Time on the Degree of Deacetylation

Chitosan is an amino polysaccharide which can be prepared from shrimp shells with several applications in medicine and tissue engineering. The most important parameter, that characterizes chitosan and its applications, is its degree of deacetylation. In this research the influence of deacetylation time on the quality of the produced chitosan was investigated by measuring the amount of glucosamine and acetyl glucosamine. The amount of glucosamine in the sample was measured using HPLC analysis based on derivation method. By deacetylation of the extracted chitin in 90 and 180 minutes, chitosan with deacetylation degree of 69.75% and 77.63% was obtained, respectively. Therefore, by increasing the deacetylation period in a constant temperature condition and NaOH concentration, the deacetylation degree is increased

Effects of gamma rays on rat testis tissue according to the morphological parameters and immunohistochemistry: radioprotective role of silymarin.

OBJECTIVE To determine the radioprotective effects of Silymarin in adult male Sprague-Dawley rats irradiated with γ-rays. METHODS The present experimental study was performed in Tehran University of Medical Sciences, Tehran, Iran from December 2009 to March 2010. The study was performed on 40 rats, which were randomly and equally divided into four groups: 1) control group: neither received Silymarin nor irradiated with γ-rays; 2) γ-irradiation group: testis region exposed to 2Gy of γ-rays; 3) Silymarin & γ-irradiation: rats received 100 mg/kg of Silymarin 24hrs before exposure to 2Gy of γ-rays; 4) Silymarin & γ-irradiation: rats received 200 mg/kg of Silymarin 24hrs before exposure to 2Gy of γ-rays. After animal experiments and preparing the tissue sections, different histological and histomorphological parameters of seminiferous tubules and the biological characteristics of Leydig cells were evaluated applying quantitative assessment, Johnson scoring, and Leydig cell apoptosis assay by TUNEL method. The data were analyzed applying ANOVA and Tukey's post hoc test, using SPSS software (V.19). RESULTS Irradiation of 2 Gy γ-rays to the testis of the rats significantly affected the frequency of spermatogonia, primary spermatocyte, round spermatid, spermatozoa, seminiferous tube and lumen diameters, thickness of the epithelium, Leydig cell nuclear diameter and volume, epithelium height, and apoptotic cells (p<0.05). However, administration of Silymarin improved the mentioned parameters specifically in 200 mg/kg of dosage. CONCLUSION Silymarin could act as a potent radioprotector and it can be used in modulation as well as improvement to radiation therapy to prevent male reproductive function, specifically seminiferous tubules in an animal model; however, its molecular mechanism is still not clear and needs more molecular researches

Exploring changes in thalamus metabolites as diagnostic biomarkers in idiopathic generalised epilepsy patients using magnetic resonance spectroscopy

Introduction: Idiopathic generalised epilepsy (IGE) refers to a group of epilepsies resulting from the activation of neurons in the whole brain. This study aimed to evaluate the metabolite changes in thalamus as diagnostic biomarkers in IGE patients compared to healthy individuals using magnetic resonance spectroscopy (MRS) technique. Methods: The MRS was performed on 35 IGE patients (26 women and 11 men) with average age of 32 (ranged from 18 to 43) and 35 healthy individuals (13 women and 22 men) with average age of 31 (ranged from 21 to 50) as the control group. The levels of N-acetylaspartate (NAA), creatine (Cr) and choline (Cho) were measured using MRS. The NAA/Cr and NAA/Cho ratios were calculated for all participants. These values were statistically compared using t-test between the groups. Results: The NAA had significant lower values in IGE patients, 9.6 (SD = 0.8) and 9.9 (SD = 0.7) for right and left thalamus, respectively, compared to 10.9 (SD = 0.9) and 10.7 (SD = 0.9) in control group. The Cr values in the left side of thalamus were significantly higher in IGE patients (6.7 [SD = 0.8] versus 5.8 [SD = 0.5]); however, there was no difference in right thalamus. Measurements showed no difference for amounts of Cho between the groups in both sides of thalamus. The NAA/Cr ratio was 1.48 (SD = 0.14) and 1.48 (SD = 0.16) for right and left thalamus, respectively, in IGE patients in comparison with 1.83 (SD = 0.2) and 1.86 (SD = 0.26) in controls. There was no meaningful variation between the NAA/Cho ratio of the right and left thalamus among the groups. Conclusion: Thalamic NAA, Cr and NAA/Cr ratio values in IGE patients showed statistical differences compared to healthy individuals. Evaluating metabolites variations in thalamus using MRS is suggested for differentiating IGE patients from healthy individuals. keywords: Epilepsy, MRI, MRS, Spectroscop

A comparative study of stored arterial versus venous blood collected using the acute normovolemic hemodilution method in coronary artery bypass grafting patients in Iran

Background In the present study, arterial and venous blood was collected from patients who were candidates for elective coronary artery bypass grafting (CABG); the blood was stored for 28 days and cellular, biomechanical, and hematological changes in blood were compared to determine whether stored arterial blood is superior to stored venous blood. Methods The present follow-up comparative study included 60 patients >18 years of age, with hemoglobin >14 mg/dl and ejection fraction >40% who were candidates for CABG. After induction of anesthesia, 250 ml of arterial or venous blood was drawn from patients (arterial blood group and venous blood group). Laboratory blood samples were taken at specified times from the collected blood and re-injected into the patients after CABG. Results Significant differences were observed in pH, partial pressure of carbon dioxide (PCO2), partial pressure of oxygen (PO2), bicarbonate (HCO3), and glucose values at several time points between the groups. Other parameters such as urea and creatinine did not show any significant differences between the groups. Conclusions Twenty-eight days of storage can have a negative effect on some of the cellular, biochemical, and hematological components of arterial and venous blood; however, the quality of stored arterial blood and venous blood does not differ significantly

Regularized Contrastive Masked Autoencoder Model for Machinery Anomaly Detection Using Diffusion-Based Data Augmentation

Unsupervised anomalous sound detection, especially self-supervised methods, plays a crucial role in differentiating unknown abnormal sounds of machines from normal sounds. Self-supervised learning can be divided into two main categories: Generative and Contrastive methods. While Generative methods mainly focus on reconstructing data, Contrastive learning methods refine data representations by leveraging the contrast between each sample and its augmented version. However, existing Contrastive learning methods for anomalous sound detection often have two main problems. The first one is that they mostly rely on simple augmentation techniques, such as time or frequency masking, which may introduce biases due to the limited diversity of real-world sounds and noises encountered in practical scenarios (e.g., factory noises combined with machine sounds). The second issue is dimension collapsing, which leads to learning a feature space with limited representation. To address the first shortcoming, we suggest a diffusion-based data augmentation method that employs ChatGPT and AudioLDM. Also, to address the second concern, we put forward a two-stage self-supervised model. In the first stage, we introduce a novel approach that combines Contrastive learning and masked autoencoders to pre-train on the MIMII and ToyADMOS2 datasets. This combination allows our model to capture both global and local features, leading to a more comprehensive representation of the data. In the second stage, we refine the audio representations for each machine ID by employing supervised Contrastive learning to fine-tune the pre-trained model. This process enhances the relationship between audio features originating from the same machine ID. Experiments show that our method outperforms most of the state-of-the-art self-supervised learning methods. Our suggested model achieves an average AUC and pAUC of 94.39% and 87.93% on the DCASE 2020 Challenge Task2 dataset, respectively