36 research outputs found

    Influence of Eu3+ dopant on physical and optical properties of lithium-borosulfophosphate glasses

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    Multi-components glass host with enhanced physical and optical features are greatly demanding for various photonics and optoelectronics devices. Selection of suitable glass former, modifier, and dopant ions with optimized composition is a key concern in the fabrication of novel optical glass materials for the aforementioned purpose. Thus, this work reports the convectional melt quench synthesis of europium (Eu3+) doped lithiumborosufophosphate glasses with composition 15Li2O-30B2O3-15SO3-(40-)P2O5-Eu2O3 (where = 0.1, 0.3, 0.5, 0.7 and 1.0 in mol%). The effect of P2O5 substitution by Eu2O3 on their physical (density, molar volume, ion concentration, polaron radius, inter-nuclear distance and field strength) and optical properties was examined. The amorphous nature of the samples was confirmed by XRD diffraction pattern. The density of glass samples was slightly increased with increasing concentration of Eu2O3. Such trend is attributed to the higher molecular weight of Eu2O3 (351.926 g/mol) than P2O5 (141.9445 g/mol). The room temperature absorption spectra revealed four weak bands in the UV-Vis range and two strong bands in the NIR range with 1.0 mol% glass sample possessing the highest intensity at 7F0→7F6 (2095 nm). Incorporation of Eu3+ ion significantly enhanced the glass absorbance and the physical properties. The results on high refractive index (~2.3), polarizability and non-linear physical features suggest that these glasses are potential for photonics and solid-state laser applications.Keywords: Borosulfophosphate glasses, Europium ions, physical properties, optical properties and photoluminescenc

    Mechanical properties of silver nanoparticles induced europium doped phosphate glasses for red laser application

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    Magnesium-zinc-sulfophosphate glasses with varying concentration of Silver nanoparticles (AgNPs) composition of 63.5P2O5-20MgO-15ZnSO4-1.5Eu2O3-zAgNps (z = 0.0, 0.1, 0.3, 0.5, 0.7,0.9 and 1.1 g in excess) was prepared using melt-quenching technique. The as-Quenched glass samples were characterised to ascertain the correlation between physical and mechanical characteristics. The enhanced Young's, shear, and bulk modulus of glasses noted a comparative rise in AgNPs contents. The Poisson's ratio improved from (0.0978 to 0.1416) while Vickers hardness (from 0.0658 to 0. 0.0682 GPa) as well as GC12 (from 0.8350 to 0.8916) were enhanced. Photoluminescence spectra (emission) of the glasses showed four peaks at 593, 613, 654, and 701 nm equivalent to 5D0?7F0, 5D0?7F2, 5D0?7F3, and 5D0?7F4 transitions in europium in which the intense peak was observed at 613 nm (red). High Quantum Efficiency (? = 97.9%) was achieved due to significant PL enhancement. The studied glass may be useful for the development of red laser

    Knowledge of electronic medical records system among frontline health care workers in Jos University teaching hospital, Plateau State Nigeria

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    Background: Electronic Medical Records system (EMRs) in any healthcare system has the potential to transform healthcare in terms of saving costs, reducing medical errors, improving service quality, increasing patients’ safety, decision-making, saving time, data confidentiality, and sharing medical. Evidence on the current state of EMR system in Nigeria health system particularly its knowledge among health professionals is limited. Hence, this study was conducted to assess the level of knowledge EMRs among frontline health care workers in a tertiary health institution in Jos, Plateau State.Methods: This was a cross-sectional study conducted between April and August 2019 among 228 frontline health care workers in Jos University Teaching Hospital using quantitative method of data collection. SPSS version 20 was used for data analysis and a p-value of ≤ 0.05 considered statistically significant.Results: The mean age of the respondents in this study was 35 ± 8 years with 93 (40.8%) being 36 years and above. The overall level of knowledge of EMRs was adjudged to be good among 163 (71.5%) of the participants. Category (pharmacists) of the respondents was found to influence good knowledge of EMRs (OR = 1.37; 95% CI = 1.007 – 1.865; p = 0.045).Conclusions: This study has demonstrated a relatively high level of good knowledge of EMRs with variation existing along the categories of health care workers bringing to light the existence of a good knowledge base in the light of future EMRs implementation

    CD98 Increases Renal Epithelial Cell Proliferation by Activating MAPKs

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    CD98 heavy chain (CD98hc) is a multifunctional transmembrane spanning scaffolding protein whose extracellular domain binds with light chain amino acid transporters (Lats) to form the heterodimeric amino acid transporters (HATs). It also interacts with β1 and β3 integrins by its transmembrane and cytoplasmic domains. This interaction is proposed to be the mechanism whereby CD98 mediates cell survival and growth via currently undefined signaling pathways. In this study, we determined whether the critical function of CD98-dependent amino acid transport also plays a role in cell proliferation and defined the signaling pathways that mediate CD98-dependent proliferation of murine renal inner medullary collecting duct (IMCD) cells. We demonstrate that downregulating CD98hc expression resulted in IMCD cell death. Utilizing overexpression studies of CD98hc mutants that either lacked a cytoplasmic tail or were unable to bind to Lats we showed that CD98 increases serum-dependent cell proliferation by a mechanism that requires the CD98hc cytoplasmic tail. We further demonstrated that CD98-dependent amino acid transport increased renal tubular epithelial cell proliferation by a mechanism that does not require the CD98hc cytoplasmic tail. Both these mechanisms of increased renal tubular epithelial cell proliferation are mediated by Erk and p38 MAPK signaling. Although increased amino transport markedly activated mTor signaling, this pathway did not alter cell proliferation. Thus, these studies demonstrate that in IMCD cells, the cytoplasmic and extracellular domains of CD98hc regulate cell proliferation by distinct mechanisms that are mediated by common MAPK signaling pathways

    Facilitating positive attitude towards drugs through drug counselling programme: An imperative for national reconstruction and reformation

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    An experimental study was embarked upon to ascertain the effectiveness or otherwise of a drug counselling programme in facilitating the formation of positive attitudes by students toward drugs and substances. Through the stratified random sampling, five secondary schools in Jos North and Jos South Local Government Areas were chosen for the study. These five schools consisted of one Armed Forces School, two Missionary Schools, one State School and one University Demonstration School. The sample consisted of two hundred SS2 students, forty each from the five sampled schools. Two hypotheses were postulated and tested. Two research questions were also posed to guide the acquisition of relevant data. The instruments consisted of attitudes and beliefs scales. Analysis of data was done using t-test statistics. The finding of the study revealed that the programme had a significant positive effect on the attitude and belief system of the experimental group of students. The implications of this study are that Drug Counselling Programme be incorporated into the counsellor education programme of all training institutions and that the counsellor should be part of the team involved in the crusade against drug use and abuse. Consequently, it was suggested that drug demand reduction programmed be given more priority as against drug supply and trafficking reduction as is the case in Nigeria today. The Nigerian Journal of Guidance and Counselling Vol. 8 (1) 2002: pp. 1-1

    Realization of efficient red laser using europium doped new boro-telluro-dolomite glass hosts: Ag nanoparticles functionality

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    Achieving highly efficient visible red emission with high color purity from the rare earth ions doped glasses containing metallic nanoparticles is of scholastic significance in the quest of novel laser glass host. Stimulated by this demand, we synthesized some new class of silver nanoparticles (Ag – NPs) embedded europium ions (Eu3+) doped boro – telluro – dolomite glasses (hereafter coded as BTDEAx, where x = 0.0, 0.1, 0.3, 0.5, 0.8 and 1.0 mol%) by convectional melt quenching method. These glasses were optically characterized using UV – Vis – NIR absorption and photoluminescence (PL) spectroscopy's to ascertain their lasing candidacy. The absorption spectra of the Eu3+ ion free sample (BTDA0.8) disclosed a single surface plasmon band characteristic of Ag – NPs at 464 nm. Meanwhile, the visible emission intensities (excited with 467 nm wavelength) of the glasses due to Ag – NPs inclusion were greatly intensified. Of all glasses, the sample prepared with 0.8 mol% of Ag NPs (BTDEAg0.8) revealed highest PL intensity enhancement. Furthermore, the attainment of high color purity (97.037 %) detected from the CIE diagram with chromaticity coordinates (0.63765, 0.36094) close to ideal red color phosphor (0.67, 0.33) indeed approved the suitability of the proposed glasses for solid state red laser construction

    Europium doped magnesium zinc sulfophosphate glass as potential red laser host

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    Demand for rare earth ions (REIs) doped inorganic glasses have been ever-increasing for diverse photonic applications. Synthesis of these glasses needs the appropriate choice of suitable host matrices, modifiers, and REIs as dopants to improve their spectroscopic traits. In this realization, a new series of magnesium-zinc-sulfophosphate glasses were prepared with varied europium ions (Eu3+) doping contents (0 to 2.0 mol%). Such melt-quench synthesized glasses were characterized at room temperature by diverse analytical techniques to determine their physical and optical properties. XRD pattern of as-quenched samples confirmed their amorphous nature. Densities of the glass system were observed to increase from 2.540 to 2.788 g.cm-3 with the increase in Eu3+ doping contents from 0 to 2.0 mol% which were attributed to the generation of more bridging oxygen atoms and enhanced network compactness. Photoluminescence (PL) emission spectra of glasses exhibited four characteristic peaks positioned at 593, 613, 654 and 701 nm assigned to corresponding 5D0→7F0, 5D0→7F2, 5D0→7F3, and 5D0→7F4 transitions in Eu3+, in which the intensity of the peak at 613 nm (red) was highest. Emission intensities of all peaks were enhanced with the rise in Eu3+ content up to 1.5 mol% and quenched thereafter. It was affirmed that the physical and optical traits of these glass compositions can be improved by adjusting the Eu3+ doping contents. The proposed glass compositions may be potential for the development of varied photonic devices especially for eye safe solid-state red laser and fibre sensors

    Correlation of mechanical properties and crystal field parameters of europium-doped magnesium-zinc-sulfophosphate glasses

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    Europium-doped magnesium–zinc–sulfophosphate glasses of molar composition (65 − x) P2O5–20MgO–15ZnSO4–xEu2O3 (x = 0.0, 0.5, 1.0, 1.5 and 2.0) were prepared via melt-quenching method. The synthesized glasses were characterized at room temperature to determine the relationship between Racah and mechanical properties. The FTIR spectra of glasses in the range of 4000–400 cm−1 revealed the presence of characteristic functional groups. The Young’s, shear and bulk moduli of glasses were observed to enhance with the increase in Eu3+ contents. The ratio increased from 0.710 to 0.747 which confirms the increase in the degree of centrality of the glasses. Racah parameters evaluated from first three major absorption bands were reduced from 72.3906 to 60.1111 cm−1 with the increase in Europium contents, thus signifying the weakening in f–f electrons repulsion. Crystal field parameters decrease from 42.2445 to 35.2397 cm−1 denoting strong covalent character of ligand bond of the synthesized glass system. The synthesized glasses have potential for the development of hard surface engineering

    indirect immunofluorescent method?

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    The aim of this study was to determine whether more than once freezing and thawing of serum affects different patterns of anti-nuclear antibodies (ANA) and anti-neutrophil cytoplasmic antibodies (ANCA) as also to determine for how many days can serum samples be reliably refrigerated (2-8 degrees C) for these tests. A total of 20 ANA (6 homogenous, 3 speckled, 3 centromere, 2 nucleolar, 2 cytoplasmic and 4 mixed) and 6 ANCA (3 PR-3 positive cANCA, 2 MPO positive pANCA, one MPO negative pANCA) positive serum samples were evaluated. The ANA and ANCA tests were studied with the indirect immunofluorescent (IIF) method using commercial kits. The effect of freezing and thawing was evaluated by comparing frozen serum samples with fresh samples during 5 freezing and thawing cycles. In addition, we analyzed the effect of storage time in the refrigerator. In none of the ANA positive serum samples, except for one mixed pattern, was negativity found in the HEp-2 and liver cells after the freezing and thawing cycles and the 21 day refrigerated period. In ANCA positive serum samples, positivity similar to initial findings continued in all samples during five cycles in freeze/thaw group and at the end of 21 days, in the refrigerated group. It may be concluded that ANA and ANCA can be reliably analyzed in serum samples with five freezing and thawing cycles and after refrigeration up to 21 days

    indirect immunofluorescent method?

    No full text
    The aim of this study was to determine whether more than once freezing and thawing of serum affects different patterns of anti-nuclear antibodies (ANA) and anti-neutrophil cytoplasmic antibodies (ANCA) as also to determine for how many days can serum samples be reliably refrigerated (2-8 degrees C) for these tests. A total of 20 ANA (6 homogenous, 3 speckled, 3 centromere, 2 nucleolar, 2 cytoplasmic and 4 mixed) and 6 ANCA (3 PR-3 positive cANCA, 2 MPO positive pANCA, one MPO negative pANCA) positive serum samples were evaluated. The ANA and ANCA tests were studied with the indirect immunofluorescent (IIF) method using commercial kits. The effect of freezing and thawing was evaluated by comparing frozen serum samples with fresh samples during 5 freezing and thawing cycles. In addition, we analyzed the effect of storage time in the refrigerator. In none of the ANA positive serum samples, except for one mixed pattern, was negativity found in the HEp-2 and liver cells after the freezing and thawing cycles and the 21 day refrigerated period. In ANCA positive serum samples, positivity similar to initial findings continued in all samples during five cycles in freeze/thaw group and at the end of 21 days, in the refrigerated group. It may be concluded that ANA and ANCA can be reliably analyzed in serum samples with five freezing and thawing cycles and after refrigeration up to 21 days
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