297 research outputs found

    Grain Boundary Segregation Predicted by Quantum-Accurate Segregation Spectra but not by Classical Models

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    In alloys, solute segregation at grain boundaries is classically attributed to three driving forces: a high solution enthalpy, a high size mismatch, and a high difference in interfacial energy. These effects are generally cast into a single scalar segregation energy and used to predict grain boundary solute enrichment or depletion. This approach neglects the physics of segregation at many competing grain boundary sites, and can also miss electronic effects that are energetically significant to the problem. In this paper, we demonstrate that such driving forces cannot explain, nor thus predict, segregation in some alloys. Using quantum-accurate segregation spectra that have recently become available for some polycrystalline alloys, we predict strong segregation for gold in aluminum, a solvent-solute combination that does not conform to classical driving forces. Our experiments confirm these predictions and reveal gold enrichment at grain boundaries that is two orders of magnitude over the bulk lattice solute concentration

    Reliable UHF long-range textile-integrated RFID tag based on a compact flexible antenna filament

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    This paper details the design, fabrication and testing of flexible textile-concealed RFID tags 1 for wearable applications in a smart city/ smart building environment. The proposed tag designs aim 2 to reduce the overall footprint, enabling textile integration whilst maintaining the read range. The 3 proposed RFID filament is less than 3.5 mm in width and 100 mm in length. The tag is based on an 4 electrically small (0.0033λ 2) high-impedance planar dipole antenna with a tuning loop, maintaining a 5 reflection coefficient less than −21 dB at 915 MHz, when matched to a commercial RFID chip mounted 6 alongside the antenna. The antenna strip and the RFID chip are then encapsulated and integrated in 7 a standard woven textile for wearable applications. The flexible antenna filament demonstrates a 1.8 8 dBi gain which shows a close agreement with the analytically calculated and numerically simulated 9 gains. The range of the fabricated tags has been measured and a maximum read range of 8.2 m was 10 recorded at 868 MHz. Moreover, the tag's maximum calculated range at 915 MHz is 18 m, which 11 is much longer than the commercially available laundry tags of larger length and width, such as 12 Invengo RFID tags. The reliability of the proposed RFID tags has been investigated using a series 13 of tests replicating textile-based use case scenarios which demonstrates its suitability for practical 14 deployment. Washing tests have shown that the textile-integrated encapsulated tags can be read after 15 over 32 washing cycles, and that multiple tags can be read simultaneously while being washed

    THE ANTIBACTERIAL ACTIVITY OF NIGELLA SATIVA AGAINST MULTI-DRUG RESISTANT PSEUDOMONAS AERUGINOSA ISOLATED FROM DIABETIC WOUND INFECTIONS

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    Thirty-five specimens were isolated from diabetic patients with superficial and deep wounds. The isolates of Pseudomonas aeruginosa were selected from cetrimide agar plates supplemented with nalidixic acid.P. aeruginosawere subjected to in vitro evaluation of antibiotic sensitivity test using antibiotics from different classes. Multi-drug resistant P. aeruginosa (MDRPA) were selected for further tests and multiple antibiotic resistance (MAR)index was calculated. Eleven commercial essential oils (EOs) were chosen to evaluate their activities as antimicrobial agents against MDRPA. The sensitivity was determined using agar disc diffusion method. The black seed oil (Nigella sativa) showed a wide spectrum of inhibition against MDRPA3. The characterization of Nigella sativa was conducted by GC-MS and FT-IR which showed the antibacterial activity and safety of this oil.&nbsp

    Light and electron microscopic study on the effect of antischizophrenic drugs on the structure of seminiferous tubules of adult male albino rats

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    Introduction. Sexual dysfunction and infertility are symptoms which have been rarely studied in patients treated with antischizophrenic drugs, aripiprazole and olanzapine, for long period. This work aimed to investigate the effects of aripiprazole and olanzapine on the structure of seminiferous tubules of rats at both light microscopic and ultrastructural levels. Material and methods. Sixty adult male rats were divided into 3 groups (n = 20): control group (Group I) and two experimental ones (II and III). Rats in Group II received 2 mg/kg/day aripiprazole while rats in Group III received 0.5 mg/kg/day olanzapine for 14 weeks. Thereafter, testis were removed and processed for both light and electron microscopic study. Qualitative morphological analyses and histomorphometric measurements of seminiferous tubules were performed. Results. Rats in Group II showed reduction of testicular weight, seminiferous tubules’ diameter, epithelial height, spermatogenic count, spermatogenic index and spermatogenic score whereas Sertoli cells count was increased. Olanzapine-treated rats also showed epithelial desquamation, separation and apoptotic changes of germ cells. Sertoli cells showed vacuolization, dilatation of smooth endoplasmic reticulum and accumulation of lipid droplets. Abnormality in the shape and structure of late spermatids and presence of giant cells were also demonstrated. Aripiprazole induced less adverse histological changes in rat testis than olanzapine. Conclusions. Olanzapine followed by aripiprazole had adverse histological effects on the structure of the semi­niferous tubules, which may affect spermatogenesis

    Antisense Phenotypes Reveal a Functional Expression of OsARF1, an Auxin Response Factor, in Transgenic Rice

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    OsARF1 is the first full-length member of auxin response factor (ARF) gene family to be cloned from monocot plant. Using quantitative RT-PCR this study found that, the transcript abundance of OsARF1 was significantly higher in embryonic tissues than in vegetative tissues. To investigate the effect of OsARF1 on the phenotype of rice, a cDNA fragment of OsARF1 was inserted in inverse orientation to the 35S promoter in vector pBin438 to produce an antisense (AS) construction. The AS-OsARF1 construct was transferred into rice (Oryza sativa L. japonica ) calli via Agrobacterium tumefaciens -mediated transformation. Molecular analysis of transgenic plants showed that the functional expression of OsARF1 was inhibited at mRNA level efficiently. The AS-OsARF1 plants showed extremely low growth, poor vigor, short curled leaves and tillered but were sterile. Therefore, the OsARF1 was shown to be essential for growth in vegetative organs and seed development

    Microevolution of serial clinical isolates of Cryptococcus neoformans var. grubii and C. gattii

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    This is the final version. Available from the publisher via the DOI in this record.The pathogenic species of Cryptococcus are a major cause of mortality owing to severe infections in immunocompromised as well as immunocompetent individuals. Although antifungal treatment is usually effective, many patients relapse after treatment, and in such cases, comparative analyses of the genomes of incident and relapse isolates may reveal evidence of determinative, microevolutionary changes within the host. Here, we analyzed serial isolates cultured from cerebrospinal fluid specimens of 18 South African patients with recurrent cryptococcal meningitis. The time between collection of the incident isolates and collection of the relapse isolates ranged from 124 days to 290 days, and the analyses revealed that, during this period within the patients, the isolates underwent several genetic and phenotypic changes. Considering the vast genetic diversity of cryptococcal isolates in subSaharan Africa, it was not surprising to find that the relapse isolates had acquired different genetic and correlative phenotypic changes. They exhibited various mechanisms for enhancing virulence, such as growth at 39°C, adaptation to stress, and capsule production; a remarkable amplification of ERG11 at the native and unlinked locus may provide stable resistance to fluconazole. Our data provide a deeper understanding of the microevolution of Cryptococcus species under pressure from antifungal chemotherapy and host immune responses. This investigation clearly suggests a promising strategy to identify novel targets for improved diagnosis, therapy, and prognosis.Wellcome TrustNational Institute of Allergy and Infectious Disease

    Next-generation IoT: harnessing AI for enhanced localization and energy harvesting in backscatter communications

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    Ongoing backscatter communications and localisation research have been able to obtain incredibly accurate results in controlled environments. The main issue with these systems is faced in complex RF environments. This paper investigates concurrent localization and ambient radio frequency (RF) energy harvesting using backscatter communication systems for Internet of Things networks. Dynamic real-world environments introduce complexity from multipath reflection and shadowing, as well as interference from movements. A machine learning framework leveraging K-Nearest Neighbors and Random Forest classifiers creates robustness against such variability. Historically, received signal measurements construct a location fingerprint database resilient to perturbations. The Random Forest model demonstrates precise localization across customized benches with programmable shuffling of chairs outfitted with RF identification tags. Average precision accuracy exceeds 99% despite deliberate placement modifications, inducing signal fluctuations emulating mobility and clutter. Significantly, directional antennas can harvest over −3 dBm, while even omnidirectional antennas provide −10 dBm—both suitable for perpetually replenishing low-energy electronics. Consequently, the intelligent backscatter platform localizes unmodified objects to customizable precision while promoting self-sustainability

    Microevolution of Serial Clinical Isolates of Cryptococcus neoformans var. grubii and C. gattii

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    We thank the Broad Institute Sequencing Platform for generating the Illumina sequences. We thank Chen-Hsin Yu for helping on the data processing of the phenotypic tests. We acknowledge the South African National Institute for Communicable Diseases’ GERMS-SA surveillance network through which these isolates were originally collected. This project has been funded in whole or in part by the following U.S. Health and Human Services grants from the National Institute of Allergy and Infectious Diseases: U19 AI110818 (Broad Institute), R01 AI93257 (J.R.P.), R01 AI73896 (J.R.P.), and R01 AI025783 (T.G.M.). R.A.F. was supported by the Wellcome Trust. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The content is solely our responsibility and does not necessarily represent the official views of the funders. The use of product names in this manuscript does not imply their endorsement by the U.S. Department of Health and Human Services. The findings and conclusions in this article are those of the authors and do not necessarily represent the views of the CDC.Peer reviewedPublisher PD

    Estimation of key potentially toxic elements in arid agricultural soils using Vis-NIR spectroscopy with variable selection and PLSR algorithms

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    Potentially toxic elements (PTEs) pose a significant threat to soil and the environment. Therefore, the fast quantification of PTEs is crucial for better management of contaminated sites. Versatile technique such as Visible near-infrared spectroscopy (Vis–NIRS) (350–2,500 nm) has attracted tremendous attention for assessing PTEs and has achieved promising results combined with successful multivariate analysis. This research investigated the potential of Vis–NIRS combined with partial least squares regression (PLSR) and variable selection methods to assess key PTEs (Cd, Co, Cu, Cr, Pb, and Zn) in agricultural soils under arid conditions. The soil samples (80) were collected from a polluted area around Al-Moheet drainage, Minya Governorate–upper Egypt. The samples were scanned using an ASD FieldSpec-4 spectroradiometer. Simulated annealing (SA) and uninformative variable elimination (UVE) were used to select the effective wavelengths in predicting PTEs. PLSR was used to develop the spectral models using the full range (FR-PLS) and feature-selected spectra techniques SA (SA-PLS) and UVE (UVE-PLS). The results indicated that UVE-PLS models performed better than FR-PLS and SA-PLS models in predicting the key PTEs. The obtained coefficient of determination (R2) and the ratio of performance to deviation (RPD) were 0.74 and 2.48 (Cr), 0.72 and 2.03 (Pb), 0.62 and 1.86 (Cd), 0.59 and 1.78 (Cu), 0.52 and 1.68 (Co), and 0.46 and 1.41 (Zn), respectively. The results suggested that the UVE-PLS spectral model is promising for predicting Cr, Pb, and Cd, and can be improved for predicting Cu, Co, and Zn elements in agricultural soils

    The Effect of Hotel Employees’ Emotional Labour on Interpersonal Counterproductive Work Behaviours

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    This research aims to shed light on the effect of hotels’ employees' emotional labour with its three levels (surface acting, deep acting and genuine emotions) on interpersonal counterproductive work behaviours. To achieve this aim, a questionnaire was designed for Egyptian hotels’ employees which was structured to cover three main parts: (1) demographic characteristics of employees, (2) employees' emotional labour and (3) interpersonal counterproductive work behaviours. Structural equation modelling (SEM) was used involving (smart- PLS) software, IBM, version 4. The results show that the hotels’ employees' emotional labour with its three levels (surface acting, deep acting and genuine emotions) affects interpersonal counterproductive work behaviours with its two types (task focused and person focused) as there is a positive effect of surface acting on interpersonal counterproductive work behaviour. Employees' emotional labour must be seriously handled within the hospitality industry as it is a very important element affecting task-focused or person-focused ICWBs in the hotel. As both surface acting and genuine emotions increase task-focused or person-focused ICWBs, deep acting decreases task-focused or person-focused ICWBs
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