Research in Malaysia

Recent research output from Malaysia (via PubMed). Updated automatically.

Source profiling of arsenic and heavy metals in the Selangor River basin and their maternal and cord blood levels in Selangor State, Malaysia.

Chemosphere. 2017 Jun 17;184:857-865

Authors: Sakai N, Alsaad Z, Thuong NT, Shiota K, Yoneda M, Ali Mohd M

Arsenic and 5 heavy metals (nickel, copper, zinc, cadmium and lead) were quantitated in surface water (n = 18) and soil/ore samples (n = 45) collected from 5 land uses (oil palm converted from forest, oil palm in peat swamp, bare land, quarry and forest) in the Selangor River basin by inductively coupled plasma mass spectrometry (ICP-MS). Geographic information system (GIS) was used as a spatial analytical tool to classify 4 land uses (forest, agriculture/peat, urban and bare land) from a satellite image taken by Landsat 8. Source profiling of the 6 elements was conducted to identify their occurrence, their distribution and the pollution source associated with the land use. The concentrations of arsenic, cadmium and lead were also analyzed in maternal blood (n = 99) and cord blood (n = 87) specimens from 136 pregnant women collected at the University of Malaya Medical Center for elucidating maternal exposure as well as maternal-to-fetal transfer. The source profiling identified that nickel and zinc were discharged from sewage and/or industrial effluents, and that lead was discharged from mining sites. Arsenic showed a site-specific pollution in tin-tungsten deposit areas, and the pollution source could be associated with arsenopyrite. The maternal blood levels of arsenic (0.82 ± 0.61 μg/dL), cadmium (0.15 ± 0.2 μg/dL) and lead (2.6 ± 2.1 μg/dL) were not significantly high compared to their acute toxicity levels, but could have attributable risks of chronic toxicity. Those in cord blood were significantly decreased in cadmium (0.06 ± 0.07 μg/dL) and lead (0.99 ± 1.2 μg/dL) but were equivalent in arsenic (0.82 ± 1.1 μg/dL) because of the different kinetics of maternal-to-fetal transfer.

PMID: 28646768 [PubMed - as supplied by publisher]

Gaps in aquatic toxicological studies of microplastics.

Chemosphere. 2017 Jun 14;184:841-848

Authors: Karami A

The contamination of aquatic environments with microplastics (MPs) has spurred an unprecedented interest among scientific communities to investigate their impacts on biota. Despite the rapid growth in the number of studies on the aquatic toxicology of MPs, controversy over the fate and biological impacts of MPs is increasingly growing mainly due to the absence of standardized laboratory bioassays. Given the complex features of MPs, such as the diversity of constituent polymers, additives, shapes and sizes, as well as continuous changes in the particle buoyancy as a result of fouling and defouling processes, it is necessary to modify conventional bioassay protocols before employing them for MP toxicity testings. Moreover, several considerations including quantification of chemicals on/in the MP particles, choice of test organisms, approaches for renewing the test solution, aggregation prevention, stock solution preparation, and units used to report MP concentration in the test solution should be taken into account. This critical review suggests some important strategies to help conduct environmentally-relevant MP bioassays.

PMID: 28646766 [PubMed - as supplied by publisher]

Related Articles

Influence of polymethyl acrylate additive on the formation of particulate matter and NOX emission of a biodiesel-diesel-fueled engine.

Environ Sci Pollut Res Int. 2017 Jun 23;:

Authors: Monirul IM, Masjuki HH, Kalam MA, Zulkifli NWM, Shancita I

The aim of this study is to investigate the effect of the polymethyl acrylate (PMA) additive on the formation of particulate matter (PM) and nitrogen oxide (NOX) emission from a diesel coconut and/or Calophyllum inophyllum biodiesel-fueled engine. The physicochemical properties of 20% of coconut and/or C. inophyllum biodiesel-diesel blend (B20), 0.03 wt% of PMA with B20 (B20P), and diesel fuel were measured and compared to ASTM D6751, D7467, and EN 14214 standard. The test results showed that the addition of PMA additive with B20 significantly improves the cold-flow properties such as pour point (PP), cloud point (CP), and cold filter plugging point (CFPP). The addition of PMA additives reduced the engine's brake-specific energy consumption of all tested fuels. Engine emission results showed that the additive-added fuel reduce PM concentration than B20 and diesel, whereas the PM size and NOX emission both increased than B20 fuel and baseline diesel fuel. Also, the effect of adding PMA into B20 reduced Carbon (C), Aluminum (Al), Potassium (K), and volatile materials in the soot, whereas it increased Oxygen (O), Fluorine (F), Zinc (Zn), Barium (Ba), Chlorine (Cl), Sodium (Na), and fixed carbon. The scanning electron microscope (SEM) results for B20P showed the lower agglomeration than B20 and diesel fuel. Therefore, B20P fuel can be used as an alternative to diesel fuel in diesel engines to lower the harmful emissions without compromising the fuel quality.

PMID: 28646309 [PubMed - as supplied by publisher]

Related Articles

The Sternal Management Accelerated Recovery Trial (S.M.A.R.T) - standard restrictive versus an intervention of modified sternal precautions following cardiac surgery via median sternotomy: study protocol for a randomised controlled trial.

Trials. 2017 Jun 23;18(1):290

Authors: Katijjahbe MA, Denehy L, Granger CL, Royse A, Royse C, Bates R, Logie S, Clarke S, El-Ansary D

BACKGROUND: The routine implementation of sternal precautions to prevent sternal complications that restrict the use of the upper limbs is currently worldwide practice following a median sternotomy. However, evidence is limited and drawn primarily from cadaver studies and orthopaedic research. Sternal precautions may delay recovery, prolong hospital discharge and be overly restrictive. Recent research has shown that upper limb exercise reduces post-operative sternal pain and results in minimal micromotion between the sternal edges as measured by ultrasound. The aims of this study are to evaluate the effects of modified sternal precautions on physical function, pain, recovery and health-related quality of life after cardiac surgery.
METHODS/DESIGN: This study is a phase II, double-blind, randomised controlled trial with concealed allocation, blinding of patients and assessors, and intention-to-treat analysis. Patients (n = 72) will be recruited following cardiac surgery via a median sternotomy. Sample size calculations were based on the minimal important difference (two points) for the primary outcome: Short Physical Performance Battery. Thirty-six participants are required per group to counter dropout (20%). All participants will be randomised to receive either standard or modified sternal precautions. The intervention group will receive guidelines encouraging the safe use of the upper limbs. Secondary outcomes are upper limb function, pain, kinesiophobia and health-related quality of life. Descriptive statistics will be used to summarise data. The primary hypothesis will be examined by repeated-measures analysis of variance to evaluate the changes from baseline to 4 weeks post-operatively in the intervention arm compared with the usual-care arm. In all tests to be conducted, a p value <0.05 (two-tailed) will be considered statistically significant, and confidence intervals will be reported.
DISCUSSION: The Sternal Management Accelerated Recovery Trial (S.M.A.R.T.) is a two-centre randomised controlled trial powered and designed to investigate whether the effects of modifying sternal precautions to include the safe use of the upper limbs and trunk impact patients' physical function and recovery following cardiac surgery via median sternotomy.
TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry identifier: ACTRN12615000968572 . Registered on 16 September 2015 (prospectively registered).

PMID: 28645301 [PubMed - in process]

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