Universiti Sains Malaysia

About: Universiti Sains Malaysia is a education organization based out in George Town, Pulau Pinang, Malaysia. It is known for research contribution in the topics: Population & Ring (chemistry). The organization has 23231 authors who have published 39356 publications receiving 655434 citations. The organization is also known as: USM & University of Science, Malaysia.

Effect of Addition of Halloysite Nanoclay and SiO2 Nanoparticles on Barrier and Mechanical Properties of Bovine Gelatin Films

Abstract: Casting method was used to prepare bovine gelatin based bio-nanocomposite films with halloysite nanoclay and nano-SiO2 as the reinforcing materials. The composition included gelatin with 20% (w/w) of glycerol (as plasticizer) compounded with halloysite nanoclay and nano-SiO2 (0%, 2%, 3%, 4%, 5% w/w), respectively. Both types of nanocomposite films showed better mechanical and water solubility than the pristine gelatin films. On comparison with the control, increase in the nanoparticles content resulted in higher tensile strength (9.19 to 13.39 and 12.22 MPa in nanoclay and nano-SiO2, respectively) and elastic modulus (1.32 to 2.99 and 3.02 MPa% in nanoclay and nano-SiO2, respectively) with lower elongation at break (80.80 to 55.72 and 40.31% in nanoclay and nano-SiO2, respectively) and water solubility (85.99 to 69.67 and 69.59% in nanoclay and nano-SiO2, respectively). Even though a decrease in water vapor permeability was recorded, it was statistically non-significant (1.94 to 1.50 and 1.73 g mm/m2 h kPa in nanoclay and nano-SiO2, respectively). Studies on the heat sealing and peel seal test, conducted to determine the seal strength of the nanocomposite films, revealed lower seal strength compared to control (739.59 to 304.95 and 397.85 N/m in nanoclay and nano-SiO2, respectively). Between the two nanomaterials used, halloysite nanoclay showed the best results in terms of mechanical properties. The results obtained support the concept of nanocomposite technology and can be employed to improve the barrier and mechanical properties of bovine gelatin films with high potential to be used for food packaging purposes.

Regional prediction of groundwater potential mapping in a multifaceted geology terrain using GIS-based Dempster–Shafer model

Abstract: A prediction at a regional scale of groundwater productivity potential mapping in an area is subjected to uncertainties that must be efficiently managed for enhancing decision making. This study explored the potential of a GIS-based Dempster–Shafer theory (DST) model as a spatial prediction model to offer solution to this problem. Seven criteria/factors regarded as positive indicators to the existence of promising groundwater reservoir in a given study area were selected and weighted in a probability-based DST approach to compute degrees of belief functions component indexes. The results of the computed belief function indexes values were processed in GIS environment to generate belief functions maps among which the uncertainty index map established uncertainty result of relatively low range of <1 to 9 % prediction in the area. The belief index map which provides concrete support for the existence of promising aquifers in the area was modeled to produce the groundwater potential zones prediction (GPZP) map. A developed mathematical model based on the relationship between the estimated Belief index values and borehole yield data established the influences of diverse rock type’s properties on the aquifer productivity in the area. The effect of coherence of criteria on the efficiency of DST model as a prediction model was also examined. The GPZP map produced was found to be 85.71 % accurate. The results of the examination of the effect of coherence of the criteria revealed that the ability of the DST model to produce accurate prediction is dependent on the exhaustiveness of the set of criteria used. The obtained results illustrate the usefulness of knowledge-driven DST model in GIS-based predictive mapping of groundwater potential zones. The results also show the capability of DST model in managing uncertainty associated with the predictive potential zones in the study area.

World Health Organization Quality of Life Assessment: brief version in Bahasa Malaysia.

Abstract: WHOQOL-100, a 100 items quality of life assessment by WHO is too lengthy to be applicable in researches where the quality of life is one of the many variables of interest. The abbreviated version with 26 items is more acceptable by subjects, especially those with illness. The generic and the abbreviated Malay version were given to subjects who were healthy and with illness. Results showed that the domain scores produced by WHOQOL-BREF correlate highly with that of WHOQOL-100. WHOQOL-BREF domain scores demonstrated good discriminant validity, construct validity, internal consistency and test-retest reliability. The study indicates that WHOQOL-BREF in its brevity offers a valid and reliable assessment of quality of life.

To use or not to use: an update on licit and illicit ketamine use

Abstract: Ketamine, a derivative of phencyclidine that was developed in the 1960s, is an anesthetic and analgesic with hallucinogenic effects. In this paper, the pharmacological and toxicological effects of ketamine are briefly reviewed. Ketamine possesses a wide safety margin but such a therapeutic benefit is somewhat offset by its emergence phenomenon (mind-body dissociation and delirium) and hallucinogenic effects. The increasing abuse of ketamine, initially predominantly in recreational scenes to experience a “k-hole” and other hallucinatory effects but more recently also as a drug abused during the workday or at home, has further pushed governments to confine its usage in many countries. Recently, urinary tract dysfunction has been associated with long-term ketamine use. In some long-term ketamine users, such damage can be irreversible and could result in renal failure and dialysis. Although ketamine has not yet been scheduled in the United Nations Conventions, previous studies using different assessment parameters to score the overall harms of drugs indicated that ketamine may cause more harm than some of the United Nations scheduled drugs. Some countries in Southeast and East Asia have reported an escalating situation of ketamine abuse. Dependence, lower urinary tract dysfunction, and sexual impulse or violence were the most notable among the ketamine-associated symptoms in these countries. These results implied that the danger of ketamine may have been underestimated previously. Therefore, the severity levels of the ketamine-associated problems should be scrutinized more carefully and objectively. To prevent ketamine from being improperly used and evolving into an epidemic, a thorough survey on the prevalence and characteristics of illicit ketamine use is imperative so that suitable policy and measures can be taken. On the other hand, recent findings that ketamine could be useful for treating major depressive disorder has given this old drug a new impetus. If ketamine is indeed a remedy for treating depression, more research on the risks and benefits of its clinical use will be indispensable.