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Fulltext Effect of Preparation Methods on the Tensile, Morphology and Solar Energy Conversion Efficiency of RGO/PMMA Nanocomposites

Kee SY, Munusamy Y, Ong KS, Lai KC

Polymers (Basel), 2017 Jun 18;9(6).
PMID: 30970908 DOI: 10.3390/polym9060230

In this study, reduced graphene oxide (RGO)/polymethyl methacrylate (PMMA) nanocomposites were prepared by employing in situ polymerization and solution blending methods. In terms of mechanical properties, RGO loading increased the Young's modulus but decreased the elongation at break for RGO/PMMA nanocomposites. Tensile strength for solution blended RGO/PMMA nanocomposites increased after adding 0.5 wt % RGO, which was attributed to the good dispersion of RGO in the nanocomposites as evidenced from SEM and TEM. Solar energy conversion efficiency measurement results showed that the optimum concentration of RGO in the RGO/PMMA nanocomposites was found to be 1.0 wt % in order to achieve the maximum solar energy conversion efficiency of 25%. In the present study, the solution blended nanocomposites exhibited better overall properties than in situ polymerized nanocomposites owing to the better dispersion of RGO in solution blending. These findings would contribute to future work in search of higher conversion efficiency using nanocomposites.
Fulltext Thermal Performance Study of Composite Phase Change Material with Polyacrylicand Conformal Coating

Kee SY, Munusamy Y, Ong KS, Cornelis Metselaar HS, Chee SY, Lai KC

Materials (Basel), 2017 Jul 28;10(8).
PMID: 28773232 DOI: 10.3390/ma10080873

The composite PCM was prepared by blending polymethyl methacrylate (PMMA) and myristic acid (MA) in different weight percentages. The MA and PMMA were selected as PCM and supporting material, respectively. As liquid MA may leak out during the phase transition, this study proposes the use of two coatings, namely a polyacrylic coating and a conformal coating to overcome the leakage problem. Both coatings were studied in terms of the leakage test, chemical compatibility, thermal stability, morphology, and reliability. No leakage was found in the PCMs with coatings compared to those without under the same proportions of MA/PMMA, thus justifying the use of coatings in the present study. The chemically compatibility was confirmed by FTIR spectra: the functional groups of PCMs were in accordance with those of coatings. DSC showed that the coatings did not significantly change the melting and freezing temperatures, however, they improved the thermal stability of composite PCMs as seen in TGA analysis. Furthermore, the composite PCMs demonstrated good thermal reliability after 1000 times thermal cycling. The latent heat of melting reduced by only 0.16% and 1.02% for the PCMs coated with conformal coating and polyacrylic coating, respectively. Therefore, the proposed coatings can be considered in preparing fatty acid/PMMA blends attributed to the good stability, compatibility and leakage prevention.
Fulltext Cross cultural translation, adaptation and reliability of the Malay version of the Canadian Acute Respiratory Illness and Flu Scale (CARIFS)

Nathan AM, Zaki R, Rozario R, Dhania N, Mohd Hamirudin SN, Eg KP, et al.

Health Qual Life Outcomes, 2015;13:139.
PMID: 26338016 DOI: 10.1186/s12955-015-0336-z

The Canadian Acute Respiratory Illness and Flu Scale (CARIFS) is a parent-proxy questionnaire that assesses severity of acute respiratory infections in children. The aim was to (a) perform a cross-cultural adaptation and (b) prove that the Malay CARIFS is a reliable tool.
Fulltext Correction: Epidemiology, clinical presentation and respiratory sequelae of adenovirus pneumonia in children in Kuala Lumpur, Malaysia

Li L, Woo YY, de Bruyne JA, Nathan AM, Kee SY, Chan YF, et al.

PLoS One, 2018;13(12):e0209720.
PMID: 30566518 DOI: 10.1371/journal.pone.0209720

[This corrects the article DOI: 10.1371/journal.pone.0205795.].
Thirteen years of invasive and noninvasive home ventilation for children in a developing country: A retrospective study

Nathan AM, Loo HY, de Bruyne JA, Eg KP, Kee SY, Thavagnanam S, et al.

Pediatr Pulmonol, 2017 04;52(4):500-507.
PMID: 27712049 DOI: 10.1002/ppul.23569

INTRODUCTION: Home ventilation (HV) for children is growing rapidly worldwide. The aim was to describe (1) the sociodemographic characteristics of children on HV and (2) the indications for, means and outcome of initiating HV in children from a developing country.
METHODOLOGY: This retrospective study included patients sent home on noninvasive or invasive ventilation, over 13 years, by the pediatric respiratory unit in a single center. Children who declined treatment were excluded.
RESULTS: Seventy children were initiated on HV: 85.7% on noninvasive ventilation, 14.3% on invasive ventilation. There was about a threefold increase from 2001-2008 (n = 18) to 2009-2014 (n = 52). Median (range) age of initiating HV was 11 (1-169) months and 73% of children were <2 years old. Common indications for HV were respiratory (57.2%), chest/spine anomalies (11.4%), and neuromuscular (10.0%). Fifty-two percent came off their devices with a median (interquartile range) usage duration of 12 (4.8, 21.6) months. Ten children (14.3%) died with one avoidable death. Children with neuromuscular disease were less likely to come off their ventilator (0.0%) compared to children with respiratory disease (62.1%). Forty-one percent of parents bought their equipment, whereas 58.6% borrowed their equipment from the medical social work department and other sources.
CONCLUSION: HV in a resource-limited country is possible. Children with respiratory disease made up a significant proportion of those requiring HV and were more likely to be weaned off. The mortality rate was low. The social work department played an important role in facilitating early discharge. Pediatr Pulmonol. 2017;52:500-507. © 2016 Wiley Periodicals, Inc.
Fulltext Epidemiology, clinical presentation and respiratory sequelae of adenovirus pneumonia in children in Kuala Lumpur, Malaysia

Li L, Woo YY, de Bruyne JA, Nathan AM, Kee SY, Chan YF, et al.

PLoS One, 2018;13(10):e0205795.
PMID: 30321228 DOI: 10.1371/journal.pone.0205795

OBJECTIVES: To describe the severity, human adenovirus (HAdV) type and respiratory morbidity following adenovirus pneumonia in children.
METHODOLOGY: Retrospective review of children under 12 years of age, admitted with HAdV pneumonia, between January 2011 and July 2013, in a single centre in Malaysia. HAdV isolated from nasopharyngeal secretions were typed by sequencing hypervariable regions 1-6 of the hexon gene. Patients were reviewed for respiratory complications.
RESULTS: HAdV was detected in 131 children of whom 92 fulfilled inclusion criteria. Median (range) age was 1.1 (0.1-8.0) years with 80% under 2 years. Twenty percent had severe disease with a case-fatality rate of 5.4%. Duration of admission (p = 0.02) was independently associated with severe illness. Twenty-two percent developed respiratory complications, the commonest being bronchiolitis obliterans (15.2%) and recurrent wheeze (5.4%). The predominant type shifted from HAdV1 and HAdV3 in 2011 to HAdV7 in 2013. The commonest types identified were types 7 (54.4%), 1(17.7%) and 3 (12.6%). Four out of the five patients who died were positive for HAdV7. Infection with type 7 (OR 8.90, 95% CI 1.32, 59.89), family history of asthma (OR 14.80, 95% CI 2.12-103.21) and need for invasive or non-invasive ventilation (OR 151.84, 95% CI 9.93-2.32E) were independent predictors of respiratory complications.
CONCLUSIONS: One in five children admitted with HAdV pneumonia had severe disease and 22% developed respiratory complications. Type 7 was commonly isolated in children with severe disease. Family history of asthma need for invasive or non-invasive ventilation and HAdV 7 were independent predictors of respiratory complications.
Fulltext Discordant identification of pediatric severe sepsis by research and clinical definitions in the SPROUT international point prevalence study

Weiss SL, Fitzgerald JC, Maffei FA, Kane JM, Rodriguez-Nunez A, Hsing DD, et al.

Crit Care, 2015;19:325.
PMID: 26373923 DOI: 10.1186/s13054-015-1055-x

Consensus criteria for pediatric severe sepsis have standardized enrollment for research studies. However, the extent to which critically ill children identified by consensus criteria reflect physician diagnosis of severe sepsis, which underlies external validity for pediatric sepsis research, is not known. We sought to determine the agreement between physician diagnosis and consensus criteria to identify pediatric patients with severe sepsis across a network of international pediatric intensive care units (PICUs).