2,752 research outputs found

    First-Principles Prediction of New 2D p-SiPN: A Wide Bandgap Semiconductor

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    Pentagonal two-dimensional ternary sheets are an emerging class of materials because of their novel characteristic and wide range of applications. In this work, we use first-principles density functional theory (DFT) calculations to identify a new pentagonal SiPN, p-SiPN, which is geometrically, thermodynamically, dynamically, and mechanically stable, and has promising experimental potential. The new p-SiPN shows an indirect bandgap semiconducting behavior that is highly tunable with applied equ-biaxial strain. It is mechanically isotropic, along the x-y in-plane direction, and is a soft material possessing high elasticity and ultimate strain. In addition, its exceptional anisotropic optical response with strong UV light absorbance, and small reflectivity and electron energy loss make it a potential material for optoelectronics and nanomechanics

    Nepali translation, cross-cultural adaptation and measurement properties of the Shoulder Pain and Disability Index (SPADI)

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    Background: The Shoulder Pain and Disability Index (SPADI) is a 13-item shoulder-specific patient-reported outcome measure (PROM). The English version is easy to use and has demonstrated excellent measurement properties for both clinical and research settings. The availability of the SPADI in Nepali would facilitate shoulder research and enhance management of patients with shoulder pain in Nepal. Therefore, the purpose of this study was to translate and cross-culturally adapt the SPADI into Nepali (SPADI-NP) and evaluate its measurement properties. Methods: The translation and adaptation process followed international guidelines. Participants completed SPADI-NP on two assessments (N = 150 at initial and 119 at follow-up assessment). A Nepali version of the Global Rating of Change score was completed at follow-up. Assessment of measurement properties included analysis of internal consistency (Cronbach's α), minimal detectable change (MDC) with standard error of measurement (SEM), test-retest reliability (intraclass correlation coefficient; ICC), validity (factor structure, construct using Pearson's correlation with the Disability of Arm and Hand [DASH]) and responsiveness (area under the curve; AUC) with minimal important change (MIC). Results: Minor changes were integrated in the adaptation process to improve cultural relevance such as dress items. Items were largely loaded under two factors (pain and disability), internal consistencies were good for the pain construct (α = 0.82) and disability (α = 0.88) and test-retest reliability was excellent (pain = 0.89, disability = 0.96). MDC was 5.7 (out of 100) with SEM = 2.1. Strong associations with the DASH (r = 0.63 pain, r = 0.81 disability) demonstrated its construct validity. The AUC was 0.68 and MIC was 12.3 (out of 100). Conclusion: The Nepali version of the SPADI demonstrated excellent reliability and validity. It can be used for the assessment of shoulder pain and disability in patients with shoulder pain in Nepal in both clinical practice and research

    Formula SAE Monocoque Chassis Development

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    Formula SAE is a collegiate competition hosted by SAE International with the primary goal being to design, manufacture, and race an open wheel race car. The Cal Poly Racing Formula SAE team strives for improvement every race season and has remained competitive as a result. The 2019-2020 management team determined that further research and development towards the chassis would yield the greatest performance benefit for future seasons, as the previous chassis platform limited packaging and mounting options for vehicle subsystems which interfaced with the chassis. A redesign of the Cal Poly Racing Formula SAE team’s carbon fiber reinforced polymer monocoque chassis was requested to improve subsystem integration, increase torsional stiffness, and reduce weight compared to the previous platform. Specifically, this senior project team focused on manufacturing process improvement and laminate design to meet these goals for the 2020 Formula SAE competition. This report details the design and manufacturing of such a chassis. Specific emphasis was placed on the geometry, laminate, and manufacturing process design. The geometry was designed using subsystem input for satisfactory integration of all subsystem components while maintaining a high specific torsional stiffness. The team also developed numerous analysis tools including spreadsheets and finite element models to design the asymmetric laminate of the chassis. Modular, multi-piece tooling was designed to produce a single-piece chassis and to allow for easy geometric changes in the future. Though two complete chassis were delivered to the Formula SAE team, the outbreak of COVID-19 prevented the collection of data that would have been used to validate the design. However, the Formula SAE team was made aware of the validation plan proposed in this report

    Large Negative Poisson\u27s Ratio and Anisotropic Mechanics in New Penta-PBN Monolayer

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    The scarce negative Poisson\u27s ratio (NPR) in a two-dimensional (2D) material is an exceptional auxetic property that offers an opportunity to develop nanoscale futuristic multi-functional devices and has been drawing extensive research interest. Inspired by the buckled pentagonal iso-structures that often expose NPR, we employ state-of-the-art first-principles density functional theory calculations and analyses to predict a new 2D metallic ternary auxetic penta-phosphorus boron nitride (p-PBN) with a high value of NPR. The new p-PBN is stable structurally, mechanically, and dynamically and sustainable at room temperature, with experimental feasibility. The short and strong quasi sp3-hybridized B-N bond and unique bond variation and geometrical reconstruction with an applied strain allow p-PBN to inherit a high value of NPR (-0.236) along the (010) direction, the highest among any other ternary penta iso-structures reported to date. Despite having a small elastic strength, the highly asymmetric Young\u27s modulus and Poisson\u27s ratio along the (100) and (010) directions indicate large anisotropic mechanics, which are crucial for potential applications in nanomechanics and nanoauxetics

    Price variation among different brands of anticancer medicines available in hospital pharmacies of Nepal.

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    Objective:To assess the variation in price among different brands of anticancer medicines available in hospital pharmacies at Nepalese cancer hospitals. Methods:The price of different brands of the same anticancer medicines available in the hospital pharmacies of two cancer hospitals was assessed. Prices of different dosage forms such as a single tablet, capsule and vial were calculated. The difference in the maximum and minimum price of the same drug manufactured by different pharmaceutical industries was determined, and the percentage variation in price was calculated. The prices of medicines (brands) were also compared with the price determined by the government where available. Results:Price variation was assessed for 31 anticancer medicines belonging to six broad categories. Prices were found to vary maximally among the following medicines, each belonging to separate categories: among alkylating agents, the price of temozolomide 100 mg capsule varied 308%; among antimetabolite agents, the price of pemetrexed 500 mg injection varied 134%; among hormonal drugs, the price of letrozole 2.5 mg tablet varied 200%; among antibody class, the price of trastuzumab 440 mg injection varied 73%; among natural products, the price of irinotecan 100 mg injection varied 590%; and among miscellaneous agents, the price of bortezomib 2 mg injection varied 241%. There was a significant difference in the mean MRP of the alkylating agents with the antimetabolites (p-value 0.006) and the monoclonal antibody (p-value <.001). Antimetabolites, natural products, hormonal therapy all had significant mean differences in their MRPs with the monoclonal antibodies. (p-value <.001) and the monoclonal antibodies had a significant mean difference in the MRP with the miscellaneous agents. (p-value <.001). Conclusions:There was a considerable variation in the price of different brands of anticancer medicines available in the Nepalese market. The Government of Nepal has regulated the prices of some medicines, including anticancer medicine. However, it is not enough as prices of the majority of anticancer medicines are still not regulated. Therefore, further strategies are needed to address the variation in the prices of anticancer medicines available in the Nepalese market

    Fermentation process for alcoholic beverage production from mahua (Madhuca indica J. F. Mel.) flowers

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    Mahua flowers are rich in sugar (68-72%), in addition to a number of minerals and one of the most important raw materials for alcohol fermentation. The present investigation was for the development of a non-distilled alcoholic beverage from Mahua flowers. Eighteen (18) treatment combinations consisting of two temperatures (25 and 30°C), three pH (4.0, 4.5 and 5.0) and three period of fermentation (7, 14 and 21 days) were used in the fermentation conditions. The maximum yield of ethanol (9.51 %) occurred at 25°C with pH 4.5 after 14 days of  fermentation of Mahua flower juice. The fermented non-distilled alcoholic beverage contained total sugar (8.83 mg/ml), reducing sugar (0.82 mg/ml), total soluble solids (6.37°Brix) titrable acidity (0.65 %), and volatile acidity (0.086%). Methanol was not detected at any stage of fermentation. The developed fermented alcoholic beverage had characteristic flavor and aroma of Mahua flowers with about 7 to 9% alcohol.Keywords: Madhuca indica, ethanol, reducing sugar, fermentation.African Journal of Biotechnology Vol. 12(39), pp. 5771-577

    Quick response code secure: a cryptographically secure anti-phishing tool for QR code attacks.

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    The two-dimensional quick response (QR) codes can be misleading due to the difficulty in differentiating a genuine QR code from a malicious one. Since, the vulnerability is practically part of their design, scanning a malicious QR code can direct the user to cloned malicious sites resulting in revealing sensitive information. In order, to evaluate the vulnerabilities and propose subsequent countermeasures, we demonstrate this type of attack through a simulated experiment, where a malicious QR code directs a user to a phishing site. For our experiment, we cloned Google's web page providing access to their email service (Gmail). Since, the URL is masqueraded into the QR code the unsuspecting user who opens the URL is directed to the malicious site. Our results proved that hackers could easily leverage QR codes into phishing attack vectors targeted at smartphone users, even bypassing web browsers safe browsing feature. In addition, the second part of our paper presents adequate countermeasures and introduces QRCS (Quick Response Code Secure). QRCS is a universal efficient and effective solution focusing exclusively on the authenticity of the originator and consequently, the integrity of QR code by using digital signatures

    Farmers’ Perception of Climate Change and Its Impacts on Agriculture

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    Climate change and climate variability drive rapid glacier melt and snowpack loss, extreme precipitation and temperature events, and alteration of water availability in the Himalayas. There is increasing observational evidence of climate change impacts on water resource availability and agricultural productivity in the central Himalayan region. Here, we assess the farmers’ perception of climate change and its impacts on agriculture in western Nepal. We interviewed 554 households and conducted eight focus group discussions to collect farmers’ perceptions of temperature and rainfall characteristics, water availability, onset and duration of different seasons, and the impacts of such changes on their lives and livelihoods. Our results indicate that the farmers’ perceptions of rising annual and summer temperatures are consistent with observations. Perception, however, contradicts observed trends in winter temperature, as well as annual, monsoon, and winter precipitation. In addition, farmers are increasingly facing incidences of extreme events, including rainfall, floods, landslides, and droughts. These hazards often impact agricultural production, reducing household income and exacerbating the economic impacts on subsistence farmers. Integrated assessment of farmers’ perceptions and hydrometeorological observations is crucial to improving climate change impact assessment and informing the design of mitigation and adaptation strategies

    Maternal E-cigarette exposure in mice alters DNA methylation and lung cytokine expression in offspring

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    Copyright © 2018 by the American Thoracic Society E-cigarette usage is increasing, especially among the young, with both the general population and physicians perceiving them as a safe alternative to tobacco smoking. Worryingly, e-cigarettes are commonly used by pregnant women. As nicotine is known to adversely affect children in utero, we hypothesized that nicotine delivered via e-cigarettes would negatively affect lung development. To test this, we developed a mouse model of maternal e-vapor (nicotine and nicotine-free) exposure and investigated the impact on the growth and lung inflammation in both offspring and mothers. Female Balb/c mice were exposed to e-fluid vapor containing nicotine (18 mg/ml nicotine E-cigarette [E-cig18], equivalent to two cigarettes per treatment, twice daily,) or nicotine free (E-cig0 mg/ml) from 6 weeks before mating until pups weaned. Male offspring were studied at Postnatal Day (P) 1, P20, and at 13 weeks. The mothers were studied when the pups weaned. In the mothers' lungs, e-cigarette exposure with and without nicotine increased the proinflammatory cytokines IL-1b, IL-6, and TNF-a. In adult offspring, TNF-a protein levels were increased in both E-cig18 and E-cig0 groups, whereas IL-1b was suppressed. This was accompanied by global changes in DNA methylation. In this study, we found that e-cigarette exposure during pregnancy adversely affected maternal and offspring lung health. As this occurred with both nicotine-free and nicotine-containing e-vapor, the effects are likely due to by-products of vaporization rather than nicotine
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