117 research outputs found

    Customized physical and structural features of phosphate-based glass-ceramics: role of ag nanoparticles and ho3+ impurities

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    The effects of silver nanoparticles (Ag NPs) embedment on the physical and structural characteristics of the holmium ions (Ho3+) activated phosphate-based glass-ceramics were assessed. Two series of such glass-ceramics were prepared using the melt-quenching and characterized. In the first series, the Ag NPs were nucleated from the incorporated AgCl via the redox process. In the second series, the pure Ag nanopowder was directly added. The overall properties of these glass-ceramics were strongly sensitive to the cooling procedure and NPs addition strategies, leading to different density and refractive index modifications in the two series. The recorded O1s XPS peaks were exploited to determine the bridging to non-bridging oxygen ratios in the studied glass-ceramics network that enabled to unfold the differences in the observed inferences. A compelling correlation among various attributes in the achieved glass-ceramics was established. Briefly, the overall traits of the proposed glass-ceramics were tailored by regulating the preparation conditions

    An Effective Knowledge-Based Modeling Approach towards a “Smart-School Care Coordination System” for Children and Young People with Special Educational Needs and Disabilities

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    There is a significant need for a computer-aided modeling, effective information analysis and ontology knowledge base models to support both special needs children and care providers. As this research work correlated to the symmetry scope, it proposes an innovative generic smart knowledge-based “School Care Coordination System” (SCCS), which is established on a novel holistic six-layered data management model. The development of the Smart-SCCS adopts a methodology of ontology engineering to transform the given theoretical unstructured special educational needs and disabilities (SEND) code of practice into a comprehensive knowledge representation and reasoning system. The intended purpose is to deliver a system that can coordinate and bring together education, health and social care services into a single application to meet the needs of children and young people (CYP) with SEND. Moreover, it enables coordination, integration and monitoring of education, health and social care activities between different actors (formal, informal and CYP in the education sector) involved in the school care process network to provide personalized care interventions based on a predefined care plan. The developed ontology knowledge-based model has been proven efficient and solved the enormous difficulties faced by schools and local authorities on a daily basis. It enabled the coordination of care and integration of information for CYP from different departments in health, social care and education. The developed model has received significant attention with great feedback from all the schools and the local authorities involved, showing its efficiency and robustness

    Lipid metabolism in astrocytic structure and function

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    Astrocytes are the most abundant glial cell in the central nervous system and are involved in multiple processes including metabolic homeostasis, blood brain barrier regulation and neuronal crosstalk. Astrocytes are the main storage point of glycogen in the brain and it is well established that astrocyte uptake of glutamate and release of lactate prevents neuronal excitability and supports neuronal metabolic function. However, the role of lipid metabolism in astrocytes in relation to neuronal support has been until recently, unclear. Lipids play a fundamental role in astrocyte function, including energy generation, membrane fluidity and cell to cell signaling. There is now emerging evidence that astrocyte storage of lipids in droplets has a crucial physiological and protective role in the central nervous system. This pathway links ÎČ-oxidation in astrocytes to inflammation, signalling, oxidative stress and mitochondrial energy generation in neurons. Disruption in lipid metabolism, structure and signalling in astrocytes can lead to pathogenic mechanisms associated with a range of neurological disorders

    Physicians’ perception and barriers to cardiopulmonary rehabilitation for heart failure patients in Saudi Arabia: a cross-sectional study

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    Background: Cardiopulmonary rehabilitation (CR) serves as a core component of the management strategy for patients with heart failure (HF). CR is administered by multidisciplinary healthcare providers, but their perceptions toward delivering CR to HF patients, and the factors and barriers that might influence referral, have not been studied. This study aims to assess physicians’ perceptions toward delivering CR programs to HF patients and identify factors and barriers that might influence their referral decisions. Methods: Between 15 February and 5 June 2022, a cross-sectional online survey with ten multiple-choice items was distributed to all general and cardiac physicians in Saudi Arabia. The characteristics of the respondents were described using descriptive statistics. Percentages and frequencies were used to report categorical variables. The statistical significance of the difference between categorical variables was determined using the chi-square (2) test. Logistic regression was used to identify referral factors. Results: Overall, 513 physicians (general physicians (78%) and cardiac doctors (22%)) completed the online survey, of which 65.0% (n = 332) were male. Of the general physicians, 236 (59%) had referred patients with HF to CR. Sixty-six (58%) of the cardiac doctors had referred patients with HF to CR. A hospital-supervised program was the preferred mode of delivering CR programs among 315 (79%) general physicians, while 84 (74%) cardiac doctors preferred to deliver CR programs at home. Apart from the exercise component, information about HF disease was perceived by 321 (80%) general physicians as the essential component of a CR program, while symptom management was perceived by 108 (95%) cardiac doctors as the essential component of a CR program. The most common patient-related factor that strongly influenced referral decisions was “fatigue related to disease” (63.40%). The availability of CR centers (48%) was the most common barrier preventing the referral of patients to CR. Conclusions: CR is an effective management strategy for HF patients, but the lack of CR centers is a major barrier to the referral of patients. A hospital-supervised program is the preferred method of delivering CR from the general physicians’ perspective, while cardiac doctors prefer home-based CR programs. Apart from the exercise component, information about HF disease and symptom management is essential components of CR programs from general physicians’ and cardiac doctors’ perspectives, respectively

    Lysogenization of a lactococcal host with three distinct temperate phages provides homologous and heterologous phage resistance

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    Lactococcus lactis is the most widely exploited microorganism in global dairy fermentations. Lactococcal strains are described as typically harboring a number of prophages in their chromosomes. The presence of such prophages may provide both advantages and disadvantages to the carrying host. Here, we describe the deliberate generation of three distinct lysogens of the model lactococcal strain 3107 and the impact of additional prophage carriage on phage-resistance and anti-microbial susceptibility. Lysogen-specific responses were observed, highlighting the unique relationship and impact of each lysogenic phage on its host. Both homologous and heterologous phage-resistance profiles were observed, highlighting the presence of possible prophage-encoded phage-resistance factors. Superinfection exclusion was among the most notable causes of heterologous phage-resistance profiles with resistance observed against members of the Skunavirus, P335, P087, and 949 lactococcal phage groups. Through these analyses, it is now possible to identify phages that may pursue similar DNA injection pathways. The generated lysogenic strains exhibited increased sensitivity to the antimicrobial compounds, nisin and lysozyme, relative to the parent strain, although it is noteworthy that the degree of sensitivity was specific to the individual (pro)phages. Overall, the findings highlight the unique impact of each prophage on a given strain and the requirement for strain-level analysis when considering the implications of lysogeny

    A device for magnetic-field angle control in magneto-optical filters using a solenoid-permanent magnet pair

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    Atomic bandpass filters are used in a variety of applications due to their narrow bandwidths and high transmission at specific frequencies. Predominantly these filters in the Faraday (Voigt) geometry, using an applied axial(transverse) magnetic field with respect to the laser propagation direction. Recently, there has been interest in filters realized with arbitrary-angle magnetic fields, which have been made by rotating permanent magnets with respect to the kk-vector of the interrogating laser beam. However, the magnetic-field angle achievable with this method is limited as field uniformity across the cell decreases as the rotation angle increases. In this work, we propose and demonstrate a new method of generating an arbitrary-angle magnetic field, using a solenoid to produce a small, and easily alterable, axial field, in conjunction with fixed permanent magnets to produce a large transverse field. We directly measure the fields produced by both methods, finding them to be very similar over the length of the vapor cell. We then compare the transmission profiles of filters produced using both methods, again finding excellent agreement. Finally, we demonstrate the sensitivity of filter profile to changing magnetic-field angle (solenoid current), which becomes easier to exploit with the much improved angle control and precision offered by our new design.Comment: 8 pages, 6 figure

    A device for magnetic-field angle control in magneto-optical filters using a solenoid-permanent magnet pair.

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    Atomic bandpass filters are used in a variety of applications due to their narrow bandwidths and high transmission at specific frequencies. Predominantly, these filters are in the Faraday (Voigt) geometry, using an applied axial (transverse) magnetic field with respect to the laser propagation direction. Recently, there has been interest in filters realized with arbitrary-angle magnetic fields, which have been made by rotating permanent magnets with respect to the k-vector of the interrogating laser beam. However, the magnetic field angle achievable with this method is limited as field uniformity across the cell decreases as the rotation angle increases. In this work, we propose and demonstrate a new method of generating an arbitrary-angle magnetic field, using a solenoid to produce a small, and easily alterable, axial field, in conjunction with fixed permanent magnets to produce a large transverse field. We directly measure the fields produced by both methods, finding them to be very similar over the length of the vapor cell. We then compare the transmission profiles of filters produced using both methods, again finding excellent agreement. Finally, we demonstrate the sensitivity of the filter profile to changing magnetic field angle (solenoid current), which becomes easier to exploit with the much improved angle control and precision offered by our new design

    Interference Mitigation Based on Radio Aware Channel Assignment for Wireless Mesh Networks

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    © 2018, Springer Science+Business Media, LLC, part of Springer Nature. An intricate network deployment for high demand users leads to simultaneous transmission in wireless mesh networks. Multiple radios are adapted to individual nodes for improving network performance and Quality of Service (QoS). However, whenever multiple radios are assigned to the same channel, co-located radio interference occurs, which poses a major drawback. This paper proposes a Radio aware Channel Assignment (Ra-CA) mechanism based on a direct graphical model for mitigation of interference in multi-radio multi-channel networks. Initially, the co-located radio interference is identified by classifying non-interfering links for simultaneous transmission in the network. Proposed channel assignment mechanism helps in allocating the minimal number of channels to the network that mitigate co-located radio interference. Performance analysis of the proposed Ra-CA strategy is carried out compared with other existing techniques, like Breadth First Search-Channel Assignment (BFS-CA) and Maximal Independent Set Channel Assignment (MaIS-CA), in multi-radio networks. Simulation results demonstrate that the proposed channel assignment scheme is more efficient compared to the existing ones, in terms of QoS parameters like, packet drop rate, packet delivery ratio, transmission delay and throughput

    Healthcare providers’ attitudes, beliefs and barriers to pulmonary rehabilitation for patients with chronic obstructive pulmonary disease in Saudi Arabia: a cross-sectional study

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    Objectives: To assess the attitude of healthcare providers (HCPs) towards the delivering of pulmonary rehabilitation (PR) to patients with chronic obstructive pulmonary disease (COPD) and identify factors and barriers that might influence referral. Design: A cross-sectional online survey consisting of nine multiple-choice questions. Settings: Saudi Arabia. Participants: 980 HCPs including nurses, respiratory therapists (RT) and physiotherapists. Primary outcome measures: HCPs attitudes towards and expectations of the delivery of PR to COPD patients and the identification of factors and barriers that might influence referral in Saudi Arabia. Results: Overall, 980 HCPs, 53.1% of whom were men, completed the survey. Nurses accounted for 40.1% of the total sample size, and RTs and physiotherapists accounted for 32.1% and 16.5%, respectively. The majority of HCPs strongly agreed that PR would improve exercise capacity 589 (60.1%), health-related quality of life 571 (58.3%), and disease self-management in patients with COPD 589 (60.1%). Moreover, the in-hospital supervised PR programme was the preferred method of delivering PR, according to 374 (38.16%) HCPs. Around 85% of HCPs perceived information about COPD, followed by smoking cessation 787 (80.3%) as essential components of PR besides the exercise component. The most common patient-related factor that strongly influenced referral decisions was ‘mobility affected by breathlessness’ (64%), while the ‘availability of PR centres’ (61%), the ‘lack of trained HCPs’ (52%) and the ‘lack of authority to refer patients’ (44%) were the most common barriers to referral. Conclusion: PR is perceived as an effective management strategy for patients with COPD. A supervised hospital-based programme is the preferred method of delivering PR, with information about COPD and smoking cessation considered essential components of PR besides the exercise component. A lack of PR centres, well-trained staff and the authority to refer patients were major barriers to referring patients with COPD. Further research is needed to confirm HCP perceptions of patient-related barriers
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