484 research outputs found
Approximate solution of two-dimensional Volterra integral equation by Chebyshev polynomial method and Adomian decomposition method
In this paper we investigate the numerical solution of two dimensional Volterra integral equations by two different methods, Chebyshev polynomial and Adomian decomposion method. Two numerical examples are given to illustrate the methods. Acomparison between the two methods is given. keywords: Chebyshev polynomials , Adomian decomposion method , two dimensional integral equations , collocation points
Vacuum fused deposition modelling system to improve tensile strength of 3D printed parts
Functional parts require high a level of strength and the current Fused Deposition Modelling (FDM) cannot be fully utilized as the end used parts. The poor mechanical strength is caused by the incomplete layer bonding during the printing process. In the printing process, the interlayer bonding is made too quick thus the layers are not fully fused together causing the reduced tensile strength. This paper presents a possible solution to this problem by incorporating vacuum technology in FDM system to improve tensile strength of 3D printed specimens. In this study, a desktop FDM machine was placed and operated inside a low pressure vacuum chamber. The results obtained show an improvement of 12.83 % of tensile strength compared to the standard specimen. This paper concludes that the low pressure environment is useful in reducing the heat loss due to convection of air, hence directly improves the specimen’s tensile strength.Keywords: additive manufacturing; fused deposition modelling; vacuum system; mechanical strength
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Salicylic Acid Effects on Growth, Yield, and Fruit Quality of Strawberry Cultivars
Scanning Electron Microscopic Studies of Microwave Sintered Al-SiC Nanocomposites and Their Properties
Al-metal matrix composites (AMMCs) reinforced with diverse volume fraction of SiC nanoparticles were synthesized using microwave sintering process. The effects of the reinforcing SiC particles on physical, microstructure, mechanical, and electrical properties were studied. The phase, microstructural, and surface analyses of the composites were systematically conducted using X-ray diffraction (XRD), scanning electron microscope (SEM), and surface profilometer techniques, respectively. The microstructural examination revealed the homogeneous distribution of SiC particles in the Al matrix. Microhardness and compressive strength of nanocomposites were found to be increasing with the increasing volume fraction of SiC particles. Electrical conductivity of the nanocomposites decreases with increasing the SiC content. ? 2018 M. A. Himyan et al.This publication was made possible by NPRP Grant 7159-2-076 from Qatar National Research Fund (a member of the Qatar Foundation).Scopu
Rearing broiler chickens under monochromatic blue light improve performance and reduce fear and stress during pre-slaughter handling and transportation
The aim of this study was to evaluate the effect of monochromatic light on broiler performance, fear and stress response during pre-slaughter handling and transportation. Two thousand unsexed one-day old Cobb broiler chicks were used. At day 34, two hundreds broilers of similar live body weight were selected and divided into two equal groups (2 group x 5 replicates). Broilers were reared under white light (WL) from 0-34 day. From 35 to 49 day, the first group was reared under WL and the second group under blue light (BL). Final body weight (FBW), tonic immobility reactions (TI), respiratory rate (RR), heterophils to lymphocytes (H/L) ratio and interlukien-1β (IL-1β) were estimated at day 49 before and after transportation. After transportation, weight of internal organs (liver, spleen, heart and bursa of fabricius) as a percentage of FBW was calculated. Results showed that there was a significant (P < 0.05) increase in FBW and reduced weight loss due to transportation in broilers reared under BL. In broilers reared under BL: TI duration, RR, H/L ratio, IL-1β and weight of internal organs (except the heart) were significantly (P < 0.05) lower. The interaction effect of light and transportation on TI duration, RR, lymphocytes, H/L ratio and IL-1β were significant (P < 0.05). Therefore, it is suggested that BL may be a good tool for improving welfare and mitigating stress not only in pre-slaughter handling but also during transportation of broilers
Reduced-iodine-dose dual-energy coronary CT angiography: qualitative and quantitative comparison between virtual monochromatic and polychromatic CT images.
To quantitatively evaluate the impact of virtual monochromatic images (VMI) on reduced-iodine-dose dual-energy coronary computed tomography angiography (CCTA) in terms of coronary lumen segmentation in vitro, and secondly to assess the image quality in vivo, compared with conventional CT obtained with regular iodine dose.
A phantom simulating regular and reduced iodine injection was used to determine the accuracy and precision of lumen area segmentation for various VMI energy levels. We retrospectively included 203 patients from December 2017 to August 2018 (mean age, 51.7 ± 16.8 years) who underwent CCTA using either standard (group A, n = 103) or reduced (group B, n = 100) iodine doses. Conventional images (group A) were qualitatively and quantitatively compared with 55-keV VMI (group B). We recorded the location of venous catheters.
In vitro, VMI outperformed conventional CT, with a segmentation accuracy of 0.998 vs. 1.684 mm <sup>2</sup> , respectively (p < 0.001), and a precision of 0.982 vs. 1.229 mm <sup>2</sup> , respectively (p < 0.001), in simulated overweight adult subjects. In vivo, the rate of diagnostic CCTA in groups A and B was 88.4% (n = 91/103) vs. 89% (n = 89/100), respectively, and noninferiority of protocol B was inferred. Contrast-to-noise ratios (CNR) of lumen versus fat and muscle were higher in group B (p < 0.001) and comparable for lumen versus calcium (p = 0.423). Venous catheters were more often placed on the forearm or hand in group B (p < 0.001).
In vitro, low-keV VMI improve vessel area segmentation. In vivo, low-keV VMI allows for a 40% iodine dose and injection rate reduction while maintaining diagnostic image quality and improves the CNR between lumen versus fat and muscle.
• Dual-energy coronary CT angiography is becoming increasingly available and might help improve patient management. • Compared with regular-iodine-dose coronary CT angiography, reduced-iodine-dose dual-energy CT with low-keV monochromatic image reconstructions performed better in phantom-based vessel cross-sectional segmentation and proved to be noninferior in vivo. • Patients receiving reduced-iodine-dose dual-energy coronary CT angiography often had the venous catheter placed on the forearm or wrist without compromising image quality
A Smart IoT-Based Prototype System for Rehabilitation Monitoring
Smart healthcare is growing significantly in the healthcare sector due to the Internet of Things. A remote monitoring system is one of the smart healthcare implementations for rehabilitating stroke patients. Nowadays, as the COVID-19 pandemic continues to spread, patients undergoing home rehabilitation have difficulty meeting with their physicians due to movement constraints. In addition, the healthcare facilities are devoted to treating patients with COVID-19. As a result, physicians and patients could not frequently meet to gather their rehabilitation progress. This study involves developing a prototype to monitor a post-stroke patient's rehabilitation process using the Arduino Nano 33 Bluetooth Low Energy (BLE) and force-sensing resistor (FSR). The prototype analyzes critical aspects of the rehabilitation process based on handgrip, heart rate, sleep, and step tracking measurements. The results of the handgrip, heart rate, sleep, and step tracking measurements are evaluated for various types of subjects and six testing approaches showed an accurate and consistent results. However, experiments partially success with a small error is detected while tracking the steps of each subject. Several recommendations are highlighted to improve the prototype using other sensors such as force sensing resistor and flex sensor for handgrip force transducer, electromyogram (EMG) sensor for stroke-patients rehabilitation, and others
A Smart IoT-Based Prototype System for Rehabilitation Monitoring
Smart healthcare is growing significantly in the healthcare sector due to the Internet of Things. A remote monitoring system is one of the smart healthcare implementations for rehabilitating stroke patients. Nowadays, as the COVID-19 pandemic continues to spread, patients undergoing home rehabilitation have difficulty meeting with their physicians due to movement constraints. In addition, the healthcare facilities are devoted to treating patients with COVID-19. As a result, physicians and patients could not frequently meet to gather their rehabilitation progress. This study involves developing a prototype to monitor a post-stroke patient's rehabilitation process using the Arduino Nano 33 Bluetooth Low Energy (BLE) and force-sensing resistor (FSR). The prototype analyzes critical aspects of the rehabilitation process based on handgrip, heart rate, sleep, and step tracking measurements. The results of the handgrip, heart rate, sleep, and step tracking measurements are evaluated for various types of subjects and six testing approaches showed an accurate and consistent results. However, experiments partially success with a small error is detected while tracking the steps of each subject. Several recommendations are highlighted to improve the prototype using other sensors such as force sensing resistor and flex sensor for handgrip force transducer, electromyogram (EMG) sensor for stroke-patients rehabilitation, and others
Bilosomes as a promising nanoplatform for oral delivery of an alkaloid nutraceutical:improved pharmacokinetic profile and snowballed hypoglycemic effect in diabetic rats
Diabetes mellitus is a life-threatening metabolic disease. At the moment, there is no effective treatment available to combat it. In this study, we aimed to develop berberine-loaded bilosomes (BER-BLS) to boost the oral bioavailability and therapeutic efficacy of berberine, a natural antidiabetic medication. The BER-BLS was fabricated using a thin-film hydration strategy and optimized using a central composite design (face-centered). The average vesicle size, entrapment efficiency, and surface charge of the optimized BER-BLS preparation were 196.5 nm, 89.7%, (−) 36.4 mV, respectively. In addition, it exhibited higher stability and better-sustained release of berberine than the berberine solution (BER-SOL). BER-BLS and BER-SOL were administered to streptozocin-induced diabetic rats. The optimized BER-BLS formulation had a significant hypoglycemic impact, with a maximum blood glucose decrease of 41%, whereas BER-SOL only reduced blood glucose by 19%. Furthermore, the pharmacological effect of oral BER-BLS and BER-SOL corresponded to 99.3% and 31.7%, respectively, when compared to subcutaneous insulin (1 IU). A pharmacokinetic analysis found a 6.4-fold rise in the relative bioavailability of berberine in BER-BLS when compared to BER-SOL at a dosage of 100 mg/kg body weight. Histopathological investigation revealed that BER-BLS is suitable for oral administration. Our data demonstrate that BLS is a potential nanocarrier for berberine administration, enhancing its oral bioavailability and antidiabetic activity
Pralsetinib for RET Fusion-Positive Advanced Non-small-Cell Lung Cancer:An Evidence Review Group Perspective of a NICE Single Technology Appraisal
The National Institute for Health and Care Excellence (NICE) invited the manufacturer (Roche) of pralsetinib (Gavreto®), as part of the single technology appraisal (STA) process, to submit evidence for the clinical effectiveness and cost effectiveness of pralsetinib for the treatment of adult patients with rearranged during transfection (RET) fusion-positive advanced non-small-cell lung cancer (NSCLC) not previously treated with a RET inhibitor. Kleijnen Systematic Reviews Ltd, in collaboration with University Medical Center Groningen, was commissioned to act as the independent Evidence Review Group (ERG). This paper summarizes the company submission (CS), presents the ERG’s critical review of the clinical and cost-effectiveness evidence in the CS, highlights the key methodological considerations, and describes the development of the NICE guidance by the Appraisal Committee. The CS reported data from the ARROW trial. ARROW is a single-arm, multicenter, non-randomized, open-label, multi-cohort study in patients with RET fusion-positive NSCLC and other advanced solid tumors. The CS included both untreated and pre-treated RET fusion-positive NSCLC patients, among other disease types. The comparators in the untreated population were pembrolizumab + pemetrexed + chemotherapy and pembrolizumab monotherapy. The comparators for the pre-treated population were docetaxel monotherapy, docetaxel + nintedanib, and platinum-based chemotherapy ± pemetrexed. As no comparators were included in ARROW, an indirect treatment comparison was conducted to estimate relative effectiveness. The ERG’s concerns included the immaturity of data, small sample size, and lack of comparative safety evidence. The ERG considers the clinical evidence presented to be insufficiently robust to inform the economic model. Even when all the ERG preferred assumptions were implemented in the model, uncertainty remained on a number of issues, such as the appropriateness of the hazard ratios and the methods and data used to derive them, long-term efficacy of pralsetinib, and direct evidence for health-related quality of life (HRQoL). NICE did not recommend pralsetinib within its marketing authorization for treating RET fusion-positive advanced non-small-cell lung cancer (NSCLC) in adults who have not had a RET inhibitor before. The uncertainty of the clinical evidence and the estimates of cost effectiveness were too high to be considered a cost-effective use of NHS resources. Therefore, pralsetinib was not recommended for routine use.</p
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