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1.
Med J Malaysia ; 75(6): 649-654, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33219172

RESUMEN

BACKGROUND AND OBJECTIVE: Physical and behavioural problems from extended usage of electronic devices are issues among primary school children. This study is aimed to investigate the prevalence of physical and behavioural complaints arising from the electronic device usage and to identify the potential factors that predicted the complaints. METHODS: This was a primary school-based cross-sectional study using multistage cluster sampling, conducted at Bau district in Sarawak, Malaysia in 40 primary schools. A questionnaire was used to collect information of usage pattern in insufficient lighting, timing and position. The physical and behavioural complaints were traced. Data analysis was performed using SPSS version 22. A p-value < 0.05 with 95% CI was considered as statistically significant. RESULTS: About 52.8% of the 569 students used digital devices in a bright room, 69.8% in the day time and 54.4% in sitting position. The physical complaints were headache (32.9%), neck, shoulder and back pain (32.9%) followed by by eye strain (31.8%). Regarding behavioural problems, 25.7% of the students had loss of interest in study and outdoor activities (20.7%), skipped meals (19.0%) and arguments/disagreements with parents (17.9%). After logistic regression analysis, the lying position (OR=1.71, 95% CI: 1.096, 2.688) and darkroom lighting (OR=2.323 95% CI: 1.138, 4.744) appeared to be potential predictors of the complaint. CONCLUSION: One-quarter of the students studied experienced physical complaints, and one-fifth had behavioural problems associated with the use of electronic devices. Lying position and darkroom lighting are the potential predictors of complaints. Therefore, we suggest that the children should use electronic devices in the sitting position with adequate room lighting.


Asunto(s)
Instituciones Académicas , Tiempo de Pantalla , Niño , Estudios Transversales , Humanos , Prevalencia , Estudiantes , Encuestas y Cuestionarios
3.
Opt Express ; 25(5): 5501-5508, 2017 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-28380810

RESUMEN

We demonstrate a ring cavity single longitudinal mode fiber optical parametric oscillator using a passive sub-ring cavity and an unpumped erbium doped fiber configured with an external fiber mirror for single mode selection. The unpumped erbium doped fiber uses its saturable absorption characteristic to generate a self-induced narrowband filter when two counter-propagating waves interfere inside the fiber. A single longitudinal mode laser is obtained with a linewidth of 17.35 kHz at a pump power of 31.2 dBm. A 3.8 nm tuning range from 1536.5 nm to 1540.3 nm is achieved with a signal-to-noise ratio of about 60 dB. The power stability of the single longitudinal mode laser is 2.07 dB over a period of 30 minutes.

5.
West Indian Med J ; 65(2): 304-307, 2015 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-26901607

RESUMEN

Preseptal cellulitis and orbital cellulitis can both present with increasing swelling, tenderness and redness around the eye, but their management differs. Preseptal cellulitis is more common and much less aggressive than orbital cellulitis. In contrast, orbital cellulitis is a medical emergency requiring urgent management. In this article, we provide a systematic approach to distinguish between preseptal cellulitis and orbital cellulitis at presentation, as the distinction between the two entities and the prompt recognition of orbital cellulitis can be potentially life-saving.

6.
West Indian Med J ; 65(2): 300-303, 2015 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-28358453

RESUMEN

Giant cell arteritis is a systemic immune-mediated vasculitis affecting the medium and large arteries. Typical symptoms include new headache, jaw claudication, tender temporal artery, polymyalgia rheumatica, fever and anorexia. Visual loss resulting from giant cell arteritis is an ophthalmic emergency and requires immediate assessment and referral to the ophthalmologist for prompt treatment with steroids. This article provides a systematic approach to the diagnosis and management of giant cell arteritis.

8.
Opt Express ; 22(18): 22190-5, 2014 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-25321594

RESUMEN

We demonstrate a linear cavity fiber optical parametric oscillator with extended pump-signal separation of 14.3 THz (116 nm). The signal laser is provided by a pair of 1675nm fiber Bragg gratings and a tunable idler from 1456.12 nm to 1462.48 nm is generated by detuning the pump wavelength in the anomalous dispersion regime of a highly nonlinear fiber. At such large pump-signal separation, we are still able to record a parametric conversion efficiency of more than -35 dB and idler optical signal-to-noise-ratio of 50 dB on average. The stability of the lasing signal and idler is examined and result shows both signal and idler peak power fluctuation is less than 1 dB over a period of 30 minutes.

11.
J Food Sci ; 74(8): C608-18, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19799657

RESUMEN

This study investigated the effects of temperature (22, 35, and 45 degrees C), storage time (48, 30, and 15 d), and packaging type on the quality of white wine in bag-in-box (BIB) during the secondary shelf life. Several enological parameters (color and contents of free and total SO2, total aldehyde, and total phenol) were monitored and correlated with oxygen transmission rate (OTR) and Fourier transform infrared (FTIR) spectral data. Time and temperature had significant effects on color development and SO2 depletion during storage. The increased absorbance at 420 nm was correlated with decreases of free SO2 and total SO2. Overall, total phenol content correlated negatively with total aldehyde content. The variance of the enological parameters can be correlated with the OTR data, indicating the barrier properties for the tested packages were different. FTIR-ATR spectra of the wine were analyzed chemometrically using PLS algorithm. The resulting models were able to predict the A(420), free SO2, total SO2, total phenol, total aldehyde, and storage time of the wines. This technique can potentially be used as an efficient tool to evaluate the quality of wine.


Asunto(s)
Manipulación de Alimentos/métodos , Embalaje de Alimentos/instrumentación , Calor , Oxígeno/química , Vino/análisis , Aldehídos/análisis , Reacción de Maillard , Modelos Químicos , Oxidación-Reducción , Permeabilidad , Fenoles/análisis , Pigmentación , Control de Calidad , Espectroscopía Infrarroja por Transformada de Fourier , Dióxido de Azufre/análisis , Factores de Tiempo
12.
J Chem Phys ; 130(13): 134703, 2009 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-19355760

RESUMEN

An atomic force microscope (AFM) has been used to study the effect of temperature on solvation forces in the liquids octamethylcyclotetrasiloxane, n-hexadecane, and n-dodecanol confined between the AFM tip and a graphite surface. Discrete solvation layers can be observed for all three liquids at all the temperatures measured (298-348K). However, with increasing temperature there is a significant decrease in the magnitude of the measured solvation forces and a reduction in the number of solvation oscillations which can be observed. Solvation forces per se are only weakly temperature dependent and the most plausible explanation is that we are measuring how the layers are squeezed from the tip-sample gap. The squeeze out process is a thermally activated phenomenon and gives rise to the large change in the magnitude of the force oscillations with temperature. A simple analysis is provided based on transition rate theory. The large change in solvation force with temperature has implications for the measurement of localized forces using AFM, particularly in interpreting biological interactions and single asperity friction.

13.
J Food Sci ; 74(3): C233-40, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19397708

RESUMEN

In this study, a method was developed for continuous electrospinning of ultrafine corn zein protein fibers with diameters ranging from 150 to 600 nm. Fiber-forming solutions with various zein concentrations (10% to 30%, w/w) and aqueous ethanol concentrations (60% to 90%, w/w) were electrospun at 15 and 20 kV. Scanning electron microscopy results showed that the morphology of zein fibers was affected by aqueous ethanol concentration, zein concentration, and the applied voltage. The optimal condition for forming bead-less fibers was found to be 20% protein, 70% alcohol, and 15 kV. The zein fibers resisted solubilization in water, although swelling and plasticization were apparent after the water treatment. The efficacy of zein fibers was tested for stabilization of a green tea polyphenol, (-)-epigallocatechin gallate (EGCG), by incorporating the EGCG in zein fiber-forming solutions. Freshly spun fibers were less effective at immobilizing the EGCG upon immersion in water (82% recovery) as compared to fibers that were aged at 0% relative humidity for at least 1 d (>98% recovery) before water immersion. Fourier transform infrared spectroscopy studies demonstrated that hydrogen bonding, hydrophobic interactions, and physical encapsulation are the major contributors to the stabilization of EGCG in zein fibers in water.


Asunto(s)
Catequina/análogos & derivados , Té/química , Zeína/química , Catequina/química , Estabilidad de Medicamentos , Electricidad , Etanol , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Microscopía Electrónica de Rastreo , Soluciones , Espectroscopía Infrarroja por Transformada de Fourier , Agua , Zeína/análisis , Zeína/ultraestructura
14.
J Food Sci ; 74(2): C170-6, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19323732

RESUMEN

In this study, glucose oxidase (GOX) was immobilized in polylactide (PLA) fibers that were used to activate the lactoperoxidase (LP) system in milk. The GOX-containing microfibers were electrospun from emulsions prepared by dispersing aqueous GOX in PLA dissolved in a chloroform and N,N-dimethylformamide blend, using sorbitan monopalmitate as an emulsifier. The enzymatic activity of GOX-in-PLA fibers (1100 +/- 400 nm diameter) was more than 19 times higher than that of the GOX-in-PLA membrane formed by direct casting, due to the larger surface area of the electrospun fibers. The activation of LP in model solutions using GOX-in-PLA fibers provided a more sustained generation of antimicrobial OSCN(-) than direct activation using H(2)O(2). Preliminary evaluation on milk samples showed that the electrospun GOX-in-PLA microfibers are capable of activating the naturally present LP system, indicating that they may be promising for active food packaging applications to extend the shelf life of milk.


Asunto(s)
Enzimas Inmovilizadas/metabolismo , Glucosa Oxidasa/metabolismo , Lactoperoxidasa/metabolismo , Leche/enzimología , Animales , Bovinos , Emulsionantes , Emulsiones , Activación Enzimática , Glucosa Oxidasa/aislamiento & purificación , Cinética , Oxidación-Reducción , Poliésteres , Compuestos de Sulfhidrilo/metabolismo
15.
Br J Ophthalmol ; 92(11): 1550-1, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18952657

RESUMEN

AIM: To describe an alternative and novel technique using cyanoacrylate glue to achieve successful limbal tissue dissection, from an organ culture media stored corneoscleral button, without an artificial anterior chamber. METHODS: A donor corneoscleral button (leftover from penetrating keratoplasty) was divided into two equal semicircular halves. A thick layer of tissue adhesive (N-butyl-2-cyanoacrylate) was spread on a sterile rubber block (the under surface of the donor punch). One half of the donor corneoscleral rim was placed epithelial side up on the adhesive and allowed to attach firmly to the block. This composite provided stability to the donor rim allowing lamellar dissection of the limbal tissue to be performed without damaging the limbal epithelium. RESULTS: Regular, partial-thickness limbal tissue was obtained. There was no histological evidence of glue or cellular toxicity of the harvested limbal stem cells. This harvested tissue had been grafted successfully in patients with limbal stem cell deficiency also undergoing keratoplasty. CONCLUSIONS: Tissue adhesive can be a simple, effective and useful tool in the dissection and harvesting of corneal limbal stem cell allografts from corneoscleral buttons stored in organ culture media.


Asunto(s)
Trasplante de Córnea/métodos , Enbucrilato , Limbo de la Córnea/citología , Células Madre , Adhesivos Tisulares , Recolección de Tejidos y Órganos/métodos , Humanos , Estudios Prospectivos , Trasplante Homólogo
16.
Int J STD AIDS ; 19(4): 222-5; quiz 226, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18482938

RESUMEN

Ocular examination should be a part of the routine assessment of the patients seen at sexually transmitted diseases (STD) clinics due to the importance of these organs in the general wellbeing of patients. It is essential to keep an open eye on ocular signs and symptoms of patients with a history of exposure to common STD pathogens, to ensure prompt investigation and management of ocular complications of the STDs, which, if left unnoticed, otherwise could subject the patients to a great deal of anxiety and distress.


Asunto(s)
Oftalmopatías/complicaciones , Enfermedades de Transmisión Sexual/complicaciones , Humanos , Enfermedades de Transmisión Sexual/clasificación
17.
Int J STD AIDS ; 19(1): 4-11, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18275637

RESUMEN

The early diagnosis and treatment of ocular disease to prevent morbidity and mortality of patients with human immunodeficiency virus (HIV) is of paramount importance. Since the advent of highly active antiretroviral therapy (HAART), the incidence of ocular complications of HIV has decreased and their manifestations and natural course are also modified. This has been observed in the face of emerging immune recovery, which per se has brought new difficulties in the process of diagnosing and management of the ocular disease. Conditions such as immune recovery uveitis could affect eyes with history of opportunistic disease with a potential to cause vision loss; with this regard, differentiation of the inflammatory process from infective causes is essential. The other sexually contracted diseases are also to be included in this complex picture because of their contribution to the clinical picture and also sharing common routes of transmission with HIV. There is very little doubt that visual deterioration would further deteriorate the already compromised quality of life of this group of patients. In this review, authors wish to provide evidence available in the medical literature around the visual health issues in HIV-infected patients and raise awareness towards the changing pattern of the ocular disease in the HAART era.


Asunto(s)
Oftalmopatías/diagnóstico , Neoplasias del Ojo/diagnóstico , Infecciones por VIH/complicaciones , Síndrome Inflamatorio de Reconstitución Inmune/complicaciones , Uveítis/diagnóstico , Oftalmopatías/microbiología , Oftalmopatías/parasitología , Oftalmopatías/virología , Neoplasias del Ojo/terapia , Infecciones por VIH/tratamiento farmacológico , Humanos , Síndrome Inflamatorio de Reconstitución Inmune/diagnóstico , Síndrome Inflamatorio de Reconstitución Inmune/terapia , Uveítis/microbiología , Uveítis/parasitología , Uveítis/virología
19.
Eye (Lond) ; 21(9): 1168-73, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16691245

RESUMEN

OBJECTIVES/AIMS: Corneal perforation can be potentially blinding unless the integrity of the globe is restored quickly. Although penetrating keratoplasty (PK) may achieve this, it carries a high risk of endothelial rejection in inflamed eyes. Deep lamellar keratoplasty (DLK) may be an alternative option to PK in such eyes owing to its potential for a lower incidence of rejection. We report the efficacy of DLK in patients with corneal perforations. PATIENTS AND METHODS: Four patients underwent layer-by-layer DLK for noninfective corneal perforation, after measures such as the use of a bandage contact lens, tissue adhesive, and conjunctival pedicle flap had failed. The preoperative visual acuity was hand movements in one patient, 1/60 in two, and 6/60 in one. All four had iris incarcerated within the corneal perforations. SF6 gas (three patients) and air (one patient) were injected into the anterior chamber at the end of surgery. RESULTS: The integrity of the globe was restored in all four patients with an improvement in visual acuity (6/60 in one and 6/36 or better in three). The mean follow-up time was 7 months. All four patients had clear corneas 3 months postoperatively, apart from the area of the original perforation. There was no recurrence of ulceration or perforation. CONCLUSION: DLK is a safe and effective therapeutic measure in the management of patients with corneal perforations acting to preserve the integrity of the globe and restore vision.


Asunto(s)
Enfermedades de la Córnea/cirugía , Trasplante de Córnea/métodos , Adolescente , Anciano , Niño , Enfermedades de la Córnea/etiología , Enfermedades de la Córnea/fisiopatología , Sustancia Propia/cirugía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Agudeza Visual
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