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1.
Heliyon ; 9(10): e20262, 2023 Oct.
Article de Anglais | MEDLINE | ID: mdl-37767474

RÉSUMÉ

The demand for new glass hosts with emergent properties is constantly growing for various miniaturized applications. Thus, some new types of Sm2O3-activated strontium-telluro-alumino-magnesium-borate glasses with copper oxide nanoparticles (CuONps) insertion were made using melt-quenching approach. The obtained glasses were characterized to determine the effects of Sm2O3 concentration changes on their thermal, structural, and luminescence properties. XRD, FTIR, and HRTEM analyses of the samples verified their glassy nature, presence of different functional units and CuONps, respectively. DTA analysis showed excellent thermal stability of these glasses with a stability factor as much as 125 °C. The optical absorption properties of the glasses were highly sensitive to Sm3+ concentrations variation. The Judd-Ofelt intensity parameters of the glasses with and without CuONps followed the trend of Ω6˃Ω4˃Ω2 and Ω4˃Ω6˃Ω2, respectively. These glasses displayed 4 visible luminescence bands at 561, 598, 645, and 705 nm corresponding to 4G5/2 â†’ 6H5/2, 4G5/2 â†’ 6H7/2, 4G5/2 â†’ 6H9/2, and 4G5/2 â†’ 6H11/2 transitions in Sm3+. In addition, branching ratio above 80% and stimulated emission cross-section up to 135.82 × 10-23 cm2 were achieved. The stimulated emission cross-section and optical gain were enhanced due to the inclusion of CuONps in the glasses. These glasses may be useful for solid state laser and optical amplifier development.

2.
Heliyon ; 9(5): e15906, 2023 May.
Article de Anglais | MEDLINE | ID: mdl-37215796

RÉSUMÉ

This paper reports an intense up-conversion luminescence from Dy3+-doped strontium-telluro-alumino-magnesium-borate glasses for the first time. The samples were made via the melt-quenching method and characterized to determine the influence of various CuO nanoparticles contents change on their up-conversion emission traits. Absorption spectral data were used to calculate the Judd-Ofelt intensity parameters. The sample without CuO nanoparticles revealed two intense photoluminescence up-conversion emission peaks at 478 and 570 nm. In addition, CuO nanoparticles-activated sample displayed about 1.4-fold up-conversion emission intensity improvement due to strong light absorption in the visible to the infrared region at 799 nm excitation. The stimulated emission cross-section of the CuO nanoparticles-activated glasses was increased from 102.4 × 10-23 to 1301.1 × 10-23 cm2 (nearly 10-fold amplification) while the branching ratio was reduced to 66.9%. Thus, CuO nanoparticles as an additive in the current glass matrix enhanced the up-conversion emission and strengthened the associated nonlinear optical properties. CIE 1931 color matching revealed the influence of CuO in modifying the up-conversion color coordinates, thereby improving the white color purity. The achieved up-conversion emission coupled with the color tunability of the proposed glasses may be advantageous for the up-conversion UV tunable laser making.

3.
Case Rep Med ; 2022: 8275326, 2022.
Article de Anglais | MEDLINE | ID: mdl-35898334

RÉSUMÉ

The global pandemic of COVID-19 is caused by SARS-CoV-2 virus. We continue to discover the wide spectrum of complications associated with COVID-19. Some well-known complications include pneumonia, acute respiratory distress syndrome, pneumothorax, disseminated intravascular coagulation (DIC), chronic fatigue, multiorgan dysfunction, and long COVID-19 syndrome. We report a rare case of a 51-year-old man with severe COVID-19 pneumonia who developed haemorrhagic shock secondary to spontaneous haemothorax after 17 days of hospitalisation. Clinicians should be aware of such occurrence, and hence, high clinical suspicion, prompt recognition of signs and symptoms of shock, and adequate resuscitation will improve the outcomes of patients.

4.
Med J Malaysia ; 77(2): 267-270, 2022 03.
Article de Anglais | MEDLINE | ID: mdl-35338643

RÉSUMÉ

Acute or subacute transverse myelitis is a rare disease caused by inflammation of the spinal cord. The extensive differential diagnosis of this disease require physician to timely decide the necessary investigations and plan for effective treatment. We report a case of anomalous multifactorial transverse myelitis in a patient with human immunodeficiency virus (HIV) who responded well with multimodal therapy. The patient was given immunosuppressive agent and plasma exchange for the demyelinating disease as well as antibiotics for neurosyphilis, antiviral for cytomegalovirus (CMV) neurologic disease, and highly active antiretroviral therapy (HAART). Three months after his first presentation, patient showed full neurology recovery and suppressed HIV viral load.


Sujet(s)
Infections à VIH , Myélite transverse , Antiviraux/usage thérapeutique , Cytomegalovirus , VIH (Virus de l'Immunodéficience Humaine) , Infections à VIH/complications , Infections à VIH/traitement médicamenteux , Humains , Myélite transverse/diagnostic , Myélite transverse/traitement médicamenteux , Myélite transverse/étiologie
5.
Appl Radiat Isot ; 174: 109791, 2021 Aug.
Article de Anglais | MEDLINE | ID: mdl-34062400

RÉSUMÉ

Terrestrial radioactivity monitoring of 238U and 232Th series, and 40K in soil is an essential practice for radioactivity and radiation measurement of a place. In conventional practice, only basic data can be in-situ measured using a survey instrument, for example radioactivity concentration in soil and ambient dose equivalent rate. For other physical quantities, for example organ absorbed dose and organ equivalent dose, the measurement is impossible to be performed and can only be computed using Monte Carlo radiation transport simulations. In the past, most of the works only focused on calculating air-kerma-to-effective dose conversion factors. However, the information on organ dose conversion factors is scarcely documented and reported. This study was conducted to calculate organ absorbed and tissue-weighted equivalent dose conversion factors as a result of exposure from terrestrial gamma radiation. Series of organ dose conversion factors is produced based on computations from Monte Carlo MCNP5 simulations using modelled gamma irradiation geometry and established adult MIRD phantom. The study found out that most of the radiation exposed organs absorb energy at comparable rates, except for dense and superficial tissues i.e., skeleton and skin, which indicated slightly higher values. The good agreement between this work and previous studies demonstrated that our gamma irradiation geometry and modelling of gamma radiation sources are adequate. Therefore, the proposed organ dose conversion factors from this study are reasonably acceptable for dose estimation in environmental radioactivity monitoring practices.


Sujet(s)
Spécificité d'organe , Contrôle des radiations/méthodes , Polluants radioactifs du sol/pharmacocinétique , Rayons gamma , Humains , Méthode de Monte Carlo , Fantômes en imagerie , Photons
6.
Ecotoxicol Environ Saf ; 208: 111727, 2021 Jan 15.
Article de Anglais | MEDLINE | ID: mdl-33396058

RÉSUMÉ

Continuous depletion in tin productions has led to a newly emerging industry that is a tin by-product (amang) processing industry to harness mega tons of tin by-products produced in the past. Amang composed of profitable multi-heavy minerals and rare-earth elements. With poorly established safety and health practices in operating plant, amang poses extremely high radioactivity problem associated with high occupational ionizing radiation exposures to workers and continuously impacting the local environment with radioactive contamination from industrial effluent and solid waste into lithosphere and water bodies. The radioactivity level of 238U and 232Th series in the mineral varies from few hundreds up to ~200,000 and ~400,000 Bq kg-1 respectively and are potential to yield more than ~ 30,000 nGy h-1 of gamma (γ) radiation exposure to plant workers. The study found out that for 8 h of work time, a worker is estimated to receive an average effective dose of 0.1 mSv per day from external γ radiation source with a maximum up to 2 mSv per day for extreme exposure situation. Interferences of different exposure routes for examples inhalation of equivalent equilibrium concentration (ECC) of 222Rn and 220Rn progenies and airborne long-lived α particles from the dusty working environment could pose a higher total effective dose as much as 5 mSv per day and 115 mSv per year. The value is 5 times higher than the annual dose limit for designated radiation worker (20 mSv) in Peninsular Malaysia. The study found that 41% of the total received an effective dose received by a worker is contributed by 222Rn, 32% of airborne particulates and dust, 23% from external γ exposure and 4% from 220Rn. Based on radioecological risk assessment, the study found out that the aquatic environment is the highly exposed group to ionizing radiation from industrial effluent discharge and sand residues. With the impotent establishment of radiation protection in the industry, plus the country newly introduced long-term plan to revive tin mining as well as its accessory amang mineral, it is necessary for the government to harmonize current regulation to improve the worker safety and health as well as sustaining local environment.


Sujet(s)
Polluants atmosphériques radioactifs/analyse , Exposition professionnelle , Dose de rayonnement , Contrôle des radiations , Poussière , Environnement , Rayons gamma , Humains , Malaisie , Minéraux , Mine
7.
Iran J Vet Res ; 22(4): 277-287, 2021.
Article de Anglais | MEDLINE | ID: mdl-35126535

RÉSUMÉ

BACKGROUND: The emergence of multidrug-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Staphylococcus aureus (MDRSA) in animals and humans with continuous contact are a great zoonotic concern. AIMS: This cross-sectional study was performed to investigate the carriage rate, genotypic characteristics, and to determine the antibiogram of S. aureus isolated from pets and pet owners in Malaysia. METHODS: Nasal and oral swab samples from 40 cats, 30 dogs, and 70 pet owners were collected through convenient sampling. Presumptive colonies on mannitol salt agar were subjected to biochemical identification. S. aureus and MRSA were confirmed by PCR detection of nuc and mecA genes, respectively. Molecular profiles for antimicrobial resistance and virulence genes in S. aureus were also determined. The antibiogram was carried out via Kirby-Bauer test using 18 antibiotics. RESULTS: 17.5% of cats, 20% of dogs, and 27% of pet owners were S. aureus positive. MRSA was also detected in dogs, and pet owners. S. aureus isolates displayed high resistance against penicillin (72.7%), and amoxicillin/clavulanate (66.7%). 39.4% of S. aureus isolates showed multidrug-resistance traits, phenotypically. Molecular characterization of S. aureus revealed the presence of mecA, tetk, tetL, ermA, ermB, ermC, msrA, scn, chp, sak, sep, and sea genes. CONCLUSION: This study showed the emergence of MRSA and MDRSA in pets and pet owners in Malaysia. The antibiogram findings showed resistance of S. aureus to multiple antibiotics. Furthermore, molecular analysis of immune evasion cluster (IEC) strongly suggests the spread of animal-adapted S. aureus lineages among pets and pet owners.

8.
J Comp Neurol ; 529(9): 2209-2226, 2021 06.
Article de Anglais | MEDLINE | ID: mdl-33319367

RÉSUMÉ

Scavenger receptor CD36 contributes significantly to lipid homeostasis, inflammation, and amyloid deposition, while CD36 deficiency is associated with restored cerebrovascular function in an Alzheimer's disease (AD) mouse model. Yet the distribution of CD36 has not been examined in the brain. Here, we characterized CD36 gene and protein expression in the brains of young, middle aged, aged, and elderly male and female C57BL/6J mice. Age-related increases in CD36 mRNA expression were observed in the male hippocampus and female midbrain. Additionally, male mice had greater CD36 mRNA expression than females in the striatum, hippocampus, and midbrain. CD36 protein was primarily expressed intravascularly, and this expression differed by region, age, and sex in the mouse brain. Although male mice brains demonstrated an increase in CD36 protein with age in several cortices, basal ganglia, hippocampus, and midbrain, a decrease with age was observed in female mice in the same regions. These data suggest that distinctive age, region, and sex expression of CD36 in the brain may contribute to Aß deposition and neuroinflammation in AD.


Sujet(s)
Maladie d'Alzheimer/métabolisme , Antigènes CD36/métabolisme , Cortex cérébral/métabolisme , Plaque amyloïde/métabolisme , Caractères sexuels , Facteurs âges , Maladie d'Alzheimer/génétique , Maladie d'Alzheimer/anatomopathologie , Animaux , Antigènes CD36/génétique , Cortex cérébral/anatomopathologie , Femelle , Cellules endothéliales de la veine ombilicale humaine , Humains , Mâle , Souris , Souris de souche-129 , Souris de lignée C57BL , Souris transgéniques , Plaque amyloïde/génétique , Plaque amyloïde/anatomopathologie
9.
Anaesthesia ; 76(3): 336-345, 2021 03.
Article de Anglais | MEDLINE | ID: mdl-33338259

RÉSUMÉ

Postoperative critical care is a finite resource that is recommended for high-risk patients. Despite national recommendations specifying that such patients should receive postoperative critical care, there is evidence that these recommendations are not universally followed. We performed a national survey aiming to better understand how patients are risk-stratified in practice; elucidate clinicians' opinions about how patients should be selected for critical care; and determine factors which affect the actual provision of postoperative critical care. As part of the second Sprint National Anaesthesia Project, epidemiology of critical care after surgery study, we distributed a paper survey to anaesthetists, surgeons and intensivists providing peri-operative care during a single week in March 2017. We collected data on respondent characteristics, and their opinions of postoperative critical care provision, potential benefits and real-world challenges. We undertook both quantitative and qualitative analyses to interpret the responses. We received 10,383 survey responses from 237 hospitals across the UK. Consultants used a lower threshold for critical care admission than other career grades, indicating potentially more risk-averse behaviour. The majority of respondents reported that critical care provision was inadequate, and cited the value of critical care as being predominantly due to higher nurse: patient ratios. Use of objective risk assessment tools was poor, and patients were commonly selected for critical care based on procedure-specific pathways rather than individualised risk assessment. Challenges were highlighted in the delivery of peri-operative critical care services, such as an overall lack of capacity, competition for beds with non-surgical cases and poor flow through the hospital leading to bed 'blockages'. Critical care is perceived to provide benefit to high-risk surgical patients, but there is variation in practice about the definition and determination of risk, how patients are referred and how to deal with the lack of critical care resources. Future work should focus on evaluating 'enhanced care' units for postoperative patients, how to better implement individualised risk assessment in practice, and how to improve patient flow through hospitals.


Sujet(s)
Attitude du personnel soignant , Prise de décision clinique/méthodes , Soins de réanimation/méthodes , Enquêtes sur les soins de santé/méthodes , Soins postopératoires/méthodes , Anesthésistes/statistiques et données numériques , Soins de réanimation/statistiques et données numériques , Enquêtes sur les soins de santé/statistiques et données numériques , Humains , Sélection de patients , Médecins/statistiques et données numériques , Soins postopératoires/statistiques et données numériques , Chirurgiens/statistiques et données numériques , Royaume-Uni
10.
Trauma Case Rep ; 30: 100373, 2020 Dec.
Article de Anglais | MEDLINE | ID: mdl-33299923

RÉSUMÉ

Cardiac injury secondary to non-penetrating trauma is more common than thought, albeit, the injury is usually minor and goes undiagnosed without significant sequelae in most cases. Blunt cardiac rupture is much rarer accounting for <0.05% of all trauma cases but lethal in most circumstances. We present a case report of a young trauma victim who presented with both right atrial rupture and traumatic atrial septal disruption (ASD) requiring extra-corporeal life support (ECLS) and surgical repair. Blunt cardiac trauma with chamber rupture and septal disruption is a devastating injury. Stopping the hemorrhage and using ECLS gave our patient time to stabilize before definitive management of her traumatic ASD.

11.
Med J Malaysia ; 75(6): 685-690, 2020 11.
Article de Anglais | MEDLINE | ID: mdl-33219178

RÉSUMÉ

OBJECTIVES: To design and develop a simple vision test algorithm for mobile application and perform a pilot study to determine its validity and reliability as a tool for vision test in the community. METHODS: A simple visual acuity test algorithm in the form of a single letter E display was designed as the optotype for development of a mobile application. The standardised optotype is presented at random to test visual acuity for corresponding level of 3/60, 6/60, 6/18, and 6/12. The final result is auto-generated based on the classification of the WHO for visual impairment and blindness. The Snellen chart was used as the gold standard to determine its validity while five different users were involved to determine its inter-rater reliability. A pilot study was performed between April till November 2019, in the Universiti Sultan Zainal Abidin Medical Centre (UMC) at Kuala Nerus and Mooris Optometrist Centre at Marang, Terengganu. A total of 279 participants aged four years old and above were involved in this study. RESULTS: The highest sensitivity was found at the vision level cut-off point of 6/12 with the percentage of 92.7% and 86.8% for the right and left eye, respectively. The specificity was more than 89% for all vision levels in both eyes. The Krippendorff's alpha value for the inter-rater reliability was 0.87 and 0.83. CONCLUSION: The relatively high level of validity and reliability obtained indicate the feasibility of using the designed optotype to develop a valid and reliable mobile app for vision test. The app can be used to screen vision by nonmedical persons, at anytime and anywhere to help improve public awareness and capability to correctly determine their visual status.


Sujet(s)
Applications mobiles , Dépistage visuel , Algorithmes , Enfant d'âge préscolaire , Humains , Projets pilotes , Reproductibilité des résultats
12.
Luminescence ; 35(4): 525-533, 2020 Jun.
Article de Anglais | MEDLINE | ID: mdl-31883298

RÉSUMÉ

Lithium borate (LB) glasses doped with dysprosium oxide (Dy2 O3 ) have been prepared by utilizing the conventional melt-quench technique. The prepared glass samples were exposed to 60 Co to check their dosimetric features and kinetic parameters. These features involve glow curves, annealing, fading, reproducibility, minimum detectable dose (MDD), and effective atomic number (Zeff ). Kinetic parameters including the frequency factors and activation energy were also determined using three methods (glow curve analysis, initial rise, and peak shape method) and were thoroughly interpreted. In addition, the incorporation of Dy impurities into LB enhanced the thermoluminescence sensitivity ~170 times. The glow from LB:Dy appeared as a single prominent peak at 190°C. The best annealing proceeding was obtained at 300°C for 30 min. Signal stability was reported for a period of 1 and 3 months with a reduction of 26% and 31%, respectively. The proposed glass samples showed promising dosimeter properties that can be recommended for personal radiation monitoring.


Sujet(s)
Borates/composition chimique , Dysprosium/composition chimique , Composés du lithium/composition chimique , Dosimétrie par thermoluminescence , Verre/composition chimique , Cinétique
13.
Comput Biol Med ; 112: 103348, 2019 09.
Article de Anglais | MEDLINE | ID: mdl-31356992

RÉSUMÉ

Accurate medical disease diagnosis is considered to be an important classification problem. The main goal of the classification process is to determine the class to which a certain pattern belongs. In this article, a new classification technique based on a combination of The Teaching Learning-Based Optimization (TLBO) algorithm and Fuzzy Wavelet Neural Network (FWNN) with Functional Link Neural Network (FLNN) is proposed. In addition, the TLBO algorithm is utilized for training the new hybrid Functional Fuzzy Wavelet Neural Network (FFWNN) and optimizing the learning parameters, which are weights, dilation and translation. To evaluate the performance of the proposed method, five standard medical datasets were used: Breast Cancer, Heart Disease, Hepatitis, Pima-Indian diabetes and Appendicitis. The efficiency of the proposed method is evaluated using 5-fold cross-validation and 10-fold cross-validation in terms of mean square error (MSE), classification accuracy, running time, sensitivity, specificity and kappa. The experimental results show that the efficiency of the proposed method for the medical classification problems is 98.309%, 91.1%, 91.39%, 88.67% and 93.51% for the Breast Cancer, Heart Disease, Hepatitis, Pima-Indian diabetes and Appendicitis datasets, respectively, in terms of accuracy after 30 runs for each dataset with low computational complexity. In addition, it has been observed that the proposed method has efficient performance compared with the performance of other methods found in the related previous studies.


Sujet(s)
Algorithmes , Diagnostic assisté par ordinateur , Enseignement médical , Logique floue , , Humains
14.
J Xray Sci Technol ; 27(1): 139-147, 2019.
Article de Anglais | MEDLINE | ID: mdl-30584178

RÉSUMÉ

BACKGROUND: Numerous techniques had been proposed to reduce radiation exposure in computed tomography (CT) including the use of radiation shielding. OBJECTIVE: This study aims to evaluate efficacy of using a bismuth breast shield and optimized scanning parameter to reduce breast absorbed doses from CT thorax examination. METHODS: Five protocols comprising the standard CT thorax clinical protocol (CP1) and four modified protocols (CP2 to CP5) were applied in anthropomorphic phantom scans. The phantom was configured as a female by placing a breast component on the chest. The breast component was divided into four quadrants, where 2 thermoluminescence dosimeters (TLD-100) were inserted into each quadrant to measure the absorbed dose. The bismuth shield was placed over the breast component during CP4 and CP5 scans. RESULTS: The pattern of absorbed doses in each breast and quadrant were approximately the same for all protocols, where the 4th quadrant > 3rd quadrant > 2nd quadrant > 1st quadrant. The mean absorbed dose value in CP3 was reduced to almost 34% of CP1's mean absorbed dose. It was reduced even lower to 15% of CP1's mean absorbed dose when the breast shield was used in CP5. CONCLUSION: This study showed that CT radiation exposure on the breast could be reduced by using a bismuth shield and low tube potential protocol without compromising the image quality.


Sujet(s)
Bismuth , Région mammaire/effets des radiations , Radioprotection/instrumentation , Femelle , Humains , Fantômes en imagerie , Dose de rayonnement , Radiographie thoracique , Tomodensitométrie
15.
Appl Radiat Isot ; 135: 7-11, 2018 May.
Article de Anglais | MEDLINE | ID: mdl-29353759

RÉSUMÉ

The performance of optically stimulated luminescence dosimeters (OSLDs, Al2O3:C) was evaluated in terms of the operational quantity of HP(10) in Co-60 external beam teletherapy unit. The reproducibility, signal depletion, and dose linearity of each dosimeter was investigated. For ten repeated readouts, each dosimeter exposed to 50mSv was found to be reproducible below 1.9 ± 3% from the mean value, indicating good reader stability. Meanwhile, an average signal reduction of 0.5% per readout was found. The dose response revealed a good linearity within the dose range of 5-50mSv having nearly perfect regression line with R2 equals 0.9992. The accuracy of the measured doses were evaluated in terms of operational quantity HP(10), wherein the trumpet curve method was used respecting the 1990 International Commission on Radiological Protection (ICRP) standard. The accuracy of the overall measurements from all dosimeters was discerned to be within the trumpet curve and devoid of outlier. It is established that the achieved OSL Al2O3:C dosimeters are greatly reliable for equivalent dose assessment.


Sujet(s)
Oxyde d'aluminium/composition chimique , Télémédecine , Luminescence , Dose de rayonnement , Dosimètres , Reproductibilité des résultats
16.
J Radiol Prot ; 36(4): R96-R111, 2016 Dec.
Article de Anglais | MEDLINE | ID: mdl-27631675

RÉSUMÉ

Malaysia has initiated a range of pre-project activities in preparation for its planned nuclear power programme. Clearly one of the first steps is the selection of sites that are deemed suitable for the construction and operation of a nuclear power plant. Here we outline the Malaysian regulatory requirements for nuclear power plant site selection, emphasizing details of the selection procedures and site characteristics needed, with a clear focus on radiation safety and radiation protection in respect of the site surroundings. The Malaysia Atomic Energy Licensing Board (AELB) site selection guidelines are in accord with those provided in International Atomic Energy Agency (IAEA) and United Stated Nuclear Regulatory Commission (USNRC) documents. To enhance the suitability criteria during selection, as well as to assist in the final decision making process, possible assessments using the site selection characteristics and information are proposed.


Sujet(s)
Conception et construction de locaux/normes , Réglementation gouvernementale , Centrales nucléaires/normes , Humains , Malaisie
17.
Luminescence ; 31(3): 754-9, 2016 May.
Article de Anglais | MEDLINE | ID: mdl-26333749

RÉSUMÉ

UNLABELLED: Influence of Nd(3+) concentration on the optical and thermoluminescence (TL) properties of melt-annealed synthesized 10 Na2O: 20 Li2O: (70-x) B2O3 : xNd2O3, where 0.1≤ x ≤0.7 (LNB) glasses are determined. The absence of sharp peaks in X-ray diffraction patterns confirms the amorphous nature of the prepared glasses. The photoluminescence spectra under 800 nm laser excitations at room temperature exhibit three prominent peaks centred at 538, 603 and 675 nm corresponding to the transitions of (4)G(7/2) → (4)I(9/2), [(4)G(7/2) → (4)I(11/2), (4)G(5/2) → (4)I(9/2)] and [(4)G(7/2) → (4)I(13/2), (4)G(5/2) → (4)I(11/2)], respectively. The TL glow curve exhibits a prominent peak (T(m)) at 180°C. The best performance of the prepared glass was found at 0.5 mol% of Nd2O3. We achieved a good linearity of TL response against dose between 0.5 to 4.0 Gy. The calculated value of the effective atomic number, Z(eff), is 7.55 which is nearly tissue equivalent (Z(eff) = 7.42). These promising features demonstrate the capability of the aforementioned glass to be used as a radiation dosimeter. HIGHLIGHTS: The thermoluminescence and optical properties of new compositions of lithium sodium borate glasses doped with Nd(3+) ions were reported. Attractive features were obtained from the TL, PL and UV-Vis light analysis. Three upconversion luminescences permitting green, orange and red emissions were observed.


Sujet(s)
Bore/composition chimique , Verre/composition chimique , Lithium/composition chimique , Luminescence , Oxygène/composition chimique , Processus photochimiques , Sodium/composition chimique , Température
18.
Appl Radiat Isot ; 102: 10-14, 2015 Aug.
Article de Anglais | MEDLINE | ID: mdl-25933405

RÉSUMÉ

The paper presents the thermoluminescence (TL) response of strontium tetraborate glass subjected to electron irradiations at various Dy2O3 concentrations ranging from 0.00 to 1.00mol%. All glass samples exhibited single broad peak with maximum peak temperature positioned at 170-215°C. The optimum TL response was found at Dy2O3 concentration 0.75mol%. This glass showed good linearity and higher sensitivity for 7MeV compared to 6MeV electrons. Analysis of kinetic parameters showed that the glasses demonstrate second order kinetic.

19.
Luminescence ; 30(8): 1330-5, 2015 Dec.
Article de Anglais | MEDLINE | ID: mdl-25828828

RÉSUMÉ

We report the impact of dysprosium (Dy(3+)) dopant and magnesium oxide (MgO) modifier on the thermoluminescent properties of lithium borate (LB) glass via two procedures. The thermoluminescence (TL) glow curves reveal a single prominent peak at 190 °C for 0.5 mol% of Dy(3+). An increase in MgO contents by 10 mol% enhances the TL intensity by a factor of 1.5 times without causing any shift in the maximum temperature. This enhancement is attributed to the occurrence of extra electron traps created via magnesium and the energy transfer to trivalent Dy(3+) ions. Good linearity in the range of 0.01-4 Gy with a linear correlation coefficient of 0.998, fading as low as 21% over a period of 3 months, excellent reproducibility without oven annealing and tissue equivalent effective atomic numbers ~8.71 are achieved. The trap parameters, including geometric factor (µg), activation energy (E) and frequency factor (s) associated with LMB:Dy are also determined. These favorable TL characteristics of prepared glasses may contribute towards the development of Li2O-MgO-B2O3 radiation dosimeters.


Sujet(s)
Borates/composition chimique , Dysprosium/composition chimique , Verre/composition chimique , Lithium/composition chimique , Composés du magnésium/composition chimique
20.
Prev Vet Med ; 119(3-4): 232-6, 2015 May 01.
Article de Anglais | MEDLINE | ID: mdl-25746928

RÉSUMÉ

A study was conducted to describe the prevalence and distribution of zoonotic Brucella melitensis in goats in Peninsular Malaysia. Using serosurveillance data of the last decade (2000-2009) involving 119,799 goats and 3555 farms, the seroprevalence of brucellosis among goats was 0.91% (95% CI=0.86-0.96) and among farms was 7.09% (95% CI=6.27-7.98). The odds of brucellosis was significantly (P<0.05) higher in the later part of the decade, in larger herd size and among the states located in the peninsula as compared to eastern Malaysia. The infection was detected throughout Malaysia but at generally low seroprevalences with states like Perlis that border neighbouring countries having higher seroprevalence of brucellosis than other non-border states.


Sujet(s)
Brucella melitensis/isolement et purification , Brucellose/médecine vétérinaire , Maladies des chèvres/épidémiologie , Animaux , Brucellose/épidémiologie , Brucellose/microbiologie , Maladies des chèvres/microbiologie , Capra , Malaisie/épidémiologie , Prévalence , Études séroépidémiologiques
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