MyMedR

Displaying publications 3021 - 3040 of 3989 in total

Abstract:

Sort:

Comfort and frictional properties of dental gloves

Roberts AD, Brackley CA

J Dent, 1996 Sep;24(5):339-43.
PMID: 8916648

OBJECTIVES: A survey of general dental practitioners and dental surgery assistants was carried out to ascertain their preferences and opinions on powder-free hydrogel-coated gloves compared with starch-powdered gloves. The aim was to relate the survey findings to laboratory measurements of the frictional characteristics of glove inner surfaces and their water absorptive capability.
METHODS: The survey was carried out using a questionnaire given to local dental practitioners. Glove friction and water absorption measurements were made using specially designed equipment.
RESULTS: The survey showed that a selected group of dentist and dental surgery assistants preferred hydrogel-coated gloves, particularly for damp donning, durability and long-term wear comfort. Laboratory measurements showed that the hydrogel coating gave a low friction coefficient against damp skin. The coating was durable, and absorbed water more readily than other treatments.
CONCLUSION: A survey of dental practitioners and dental surgery assistants and laboratory measurements indicates that hydrogel-coated gloves have superior properties, and are preferred to other non-sterile glove types.

Matched MeSH terms: Water
Fulltext Data on population density, growth, survival, water quality, larval stage index and ingestion rate of selected microalgae of portunids crabs at different feeding regimes

Syafaat MN, Muhammad T, Abol-Munafi AB, Ikhwanuddin M

Data Brief, 2019 Oct;26:104438.
PMID: 31528675 DOI: 10.1016/j.dib.2019.104438

Population density, growth, survival, water quality and larval stage index of purple mud crab, Scylla tranquebarica at different feeding regimes and the data on ingestion rate of chosen microalgae, survival and larval development of blue swimming crab, Portunus pelagicus are presented. A twenty days of S. tranquebarica larval culture from zoeal 1 until megalopa stage under two different feeding regimes of A) Rotifer, Artemia nauplii and shrimp meat and B) Rotifer, Artemia nauplii and artificial feed is shared. A method on investigation of individual larvae of P. pelagicus capability to catch four different types of microalgae within 24 h is also shared. Direct eye observation, data collected through the larval rearing culture of S. tranquebarica and further statistical analysis were done daily until the crabs reached the megalopa stage. The result obtained from the optimum density of selected microalgae fed by individual larvae of P. pelagicus will be combined with the highest survival rate and larval stage index to develop feeding schedule for crab larvae P. pelagicus. This dataset has not previously been published and is of great potential for further comparison with other - and future investigation of various feeding regimes affected the crab culture. The collected information could be used as a standard feeding regime for nursery and hatchery seed production of others portunids crabs. The data described in this article are available as a supplementary file to this article.

Matched MeSH terms: Water Quality
Fulltext Knowledge, attitude and practice on dengue among adult population in Felda Sungai Pancing Timur, Kuantan, Pahang

Karimah Hanim, A.A., Razman, M.R., Jamalludin, A.R., Nasreen, E.H., Htike Myat Phyu, SweSwe, L., et al.

International Medical Journal Malaysia, 2017;16(2):3-9.
MyJurnal

Background: With increasing number of dengue cases in Malaysia, it’s of utmost importance that immediate
action be taken to limit the epidemic. Since dengue control is a behavioral problem, the knowledge,
attitude and practice in population needs to be studied in order to control the disease. Hence, the aim of
this study is to assess knowledge, attitude and practice regarding dengue and its associated factors among
adult residents of Felda Sungai Panching Timur (SPT), Kuantan, Pahang, 2014.

Method: A cross sectional
study was carried out involving 265 adult respondents. A face to face interview questionnaire which was
divided into 2 parts (Part A: Sociodemoghraphic; Part B: Knowledge, Attitude and Practice) was used. Data
was analyzed using descriptive statistics, simple and multiple logistic regression.

Results: 53.2% of the
respondents had good knowledge about dengue and it was found that the main source of information from
mass media (76.6%). However, only 43.4% were found to have good attitude towards dengue. Multiple
Logistic Regression analysis showed there was no association between sociodemographic characteristics with
the level of knowledge and attitude towards dengue. There was also no association found between
knowledge of dengue and the attitude of the respondents towards dengue. Descriptive analysis on the
practice of dengue showed majority of the respondents who had possible breeding site for Aedes mosquitos
(water container, drains/gutter roof/flower pots/tires) in their compound practiced good habit in
preventing the Aedes mosquitoes from breed.

Conclusion: Although knowledge and practice towards dengue
is good, their attitude require improvement.

Matched MeSH terms: Water
Fulltext Dry Thermotropic Glycolipid Self-Assembly:A Review

Hashim R, Zahid NI, Velayutham TS, Aripin NFK, Ogawa S, Sugimura A

J Oleo Sci, 2018 Jun 01;67(6):651-668.
PMID: 29760332 DOI: 10.5650/jos.ess17261

Also recognized as carbohydrate liquid crystals, glycolipids are amphiphiles whose basic unit comprises of a sugar group attached to an alkyl chain. Glycolipids are amphitropic, which means these materials form liquid crystal self-assemblies when dry (thermotropic) as well as when dissolved in solvents (lyotropic/surfactants) such as water. Many glycolipids are also naturally derived since these can be found in cell membranes. Their membrane and surfactant functions are largely understood through their lyotropic properties. While glycolipids are expected to play major roles as eco-friendly surfactants in the global surfactant market, their usefulness as thermotropic liquid crystal material is, to date, unknown, due to relatively lack of research performed and data reported in the literature. Understandably since glycolipids are hygroscopic with many hydroxy groups, removing the last trace water is very challenging. In recent time, with careful lyophilization and more consistent characterization technique, some researchers have attempted serious studies into "dry" or anhydrous glycolipids. Motivated by possible developments of novel thermotropic applications, some results from these studies also provide surprising new understanding to support conventional wisdom of the lyotropic systems. Here we review the dry state of glycosides, a family of glycolipids whose sugar headgroup is linked to the lipid chain via a glycosidic oxygen linker. The structure property relationship of both linear and anhydrous Guerbet glycosides will be examined. In particular, how the variation of sugar stereochemistry (e.g. anomer vs. epimer), the chain length and chain branching affect the formation of thermotropic liquid crystals phases, which not only located under equilibrium but also far from equilibrium conditions (glassy phase) are scrutinized. The dry glycolipid assembly has been subjected to electric and magnetic fields and the results show interesting behaviors including a possible transient current generation.

Matched MeSH terms: Water
Fulltext Lactase deficiency and lactose intolerance in a multiracial Asian population in Malaysia

Goh LH, Mohd Said R, Goh KL

JGH Open, 2018 Dec;2(6):307-310.
PMID: 30619942 DOI: 10.1002/jgh3.12089

Background and Aims: There have been few reports on lactase deficiency (LD) and lactose intolerance (LI) in Malaysia, which has a peculiar mix of three distinct major Asian races-Malay, Chinese, and Indian. The aim of this study was to determine the prevalence of LD and LI in a young multiethnic Malaysian population.
Methods: Lactase activity was measured with a 13CO2 lactose breath test using an infrared spectrometer. Each subject took 25 g of lactose naturally enriched in 13CO2 together with 250 mL of water after an overnight fast. Breath samples were collected at baseline and at 15-min intervals for 180 min. Subjects were asked to report gastrointestinal (GI) symptoms following ingestion of the lactose test meal.
Results: Of the 248 subjects tested, 216 (87.1%) were lactase deficient. We found no significant differences in the presentation of LD between gender and races. LD was found in 87.5% of males and 86.8% of females (P = 0.975) and in different races: Chinese (88.5%) versus Malay (83.1%) (P = 0.399), Indian (90.5%) versus Malay (P = 0.295), and Chinese versus Indian (P = 0.902). LI was diagnosed in only 49 (19.8%) subjects; 35 patients had diarrhea, while the remainder had at least two other GI symptoms after the lactose meal.
Conclusion: The prevalence of LD was high in all three major ethnic groups-Malays, Chinese, and Indians. Ironically, the prevalence of LI was low overall.

Matched MeSH terms: Water
Fulltext The effect of dental unit waterline flushing on the quality of water in dental teaching center in Malaysia

Sa’adiah Shahabudin, Rohayu Hami, Lim, Lee-Sim, Amalina Salleh

Journal of Biomedical and Clinical Sciences, 2018;3(1):72-74.
MyJurnal

The aim of this study to assess the efficiency of flushing
method of Dental Unit Waterline (DUWL) system in reducing the
number of microorganism. Water samples were taken before and after
two minutes of flushing from air-water syringes system in ten randomly
selected dental units in a Dental Teaching Centre. These samples
were immediately transferred to the microbiology laboratory in the cool
box within 8 hours for the heterotrophic plate count (HPC) test. Paired
t-test was used to analyse number of microbe before and after flushing.
The numbers of colony forming unit (CFU) ranged from 13,000 to
120,000CFU/ml in unflushed samples, and 3,000 to 15,000CFU/ml in
flushed samples. The mean HPC post-flushing was lower than preflushing [8360.00 (4561.48) vs 63300.00 (44587.12) CFU/ml]. The
mean HPC between pre- and post-flushing was significantly different
(P=0.004, 95% CI 22039.52, 87840.48). The coliform count from the
control was 140 CFU/ml. In conclusion, flushing method of DUWL
system significantly reduces the number of microorganisms in the
dental unit. However, the level of microorganisms still does not meet
the standard guideline by Environmental Protection Agency for safe
drinking water, which should be below 500 CFU/ml. In our opinion, the
duration of flushing should be increased and additional chemical
treatments of the dental units should be implemented to ensure the
safety of patients and dental personnel.

Matched MeSH terms: Drinking Water
Fulltext Horseshoe crab bio-ecological data from Balok, East Coast Peninsular Malaysia

Zauki NAM, Satyanarayana B, Fairuz-Fozi N, Nelson BR, Martin MB, Akbar-John B, et al.

Data Brief, 2019 Feb;22:458-463.
PMID: 30619923 DOI: 10.1016/j.dib.2018.12.027

The data available in this repository were gathered from Balok, the only most productive spawning site for horseshoe crabs Tachypleus gigas and Carcinoscorpius rotundicauda in East Coast of Peninsular Malaysia. The mangrove horseshoe crab, C. rotundicauda population and spawning data are available in the first table. The horseshoe crabs were retrieved from Balok River using 11.43 cm mesh size gill nets installed at the river mouth, the confluence and last meander. The arthropods were inspected for damage, abnormality and growth before their release into Balok River, particularly at the site of capture. Sediment samples were retrieved at their spawning grounds to ascertain sediment composition and size classifications which were also processed using Logarithmic Method of Moments. Water parameters like temperature, pH and salinity were also investigated during year 2016. All these information are compiled into the second table and arranged according to the period of data availability. The horseshoe crab catch data of years 2012, 2013, 2014, 2015 and 2016 were made available by artisanal fisher and compiled in the third and fourth table for inter-species comparison.

Matched MeSH terms: Water
Fulltext Neuropsychiatric manifestations of osmotic demyelination syndrome secondary to overcorrection of severe hyponatraemia in hyperemesis gravidarum: a case report

Sim Mervyn Ian, Nor Zuraida Zainal, Aili Hanim

Malaysian Journal of Psychiatry, 2018;27(2):0-0.
MyJurnal

Osmotic demyelination syndrome (ODS) may occur as a consequence of a
rapid change in serum osmolality. We report a case of a 32-year-old woman
who presented to the hospital with symptoms suggestive of severe
hyperemesis gravidarum. Blood investigation results showed that patient had
severe hyponatraemia (serum sodium 109 mmol/L) and hypokalaemia
(serum potassium 1.7 mmol/L). Active and vigorous corrections to these
electrolyte imbalances had led to an overly increased of serum sodium levels
within a short duration of time. Four days after the rapid correction, patient
started exhibiting neuropsychiatric manifestations. Radiological findings
were consistent with the diagnosis of ODS. The neuropsychiatric symptoms
experienced by patient gradually worsened with time. Subsequently,
intravenous methylprednisolone was administered to patient. Patient showed
marked response to the steroid given. At the time of discharge, twenty-seven
days later, patient had recovered from most of the neuropsychiatric sequelae;
but still required assistance during ambulation. In conclusion, correction of
electrolyte imbalances should be done in a more judicious manner. Prudent
corrections of electrolyte alterations could have possibly prevented the onset
of ODS and its’ devastating neuropsychiatric sequelae in this patient.

Matched MeSH terms: Water-Electrolyte Imbalance
Fulltext Evaluation of the Performance of Helmet Prototypes Fabricated from Acrylonitrile Butadiene Styrene Composites Filled with Natural Resource

Nikmatin S, Hermawan B, Irmansyah I, Indro MN, Kueh ABH, Syafiuddin A

Materials (Basel), 2018 Dec 22;12(1).
PMID: 30583516 DOI: 10.3390/ma12010034

The performance of helmet prototypes fabricated from acrylonitrile butadiene styrene composites filled with oil palm empty fruit bunch fibers was evaluated. The fibers were produced using a milling procedure, while the composites were fabricated using a single-screw extrusion. The physical characteristics of the produced fibers, which are water content, size, and density, were investigated. In addition, the mechanical properties of the produced helmets, including shock absorption, yield stress, frequency, and head injury criterion (HIC), were examined. The impact strength of the produced helmets increases with the rise of filler content. In addition, the helmets were also able to withstand a considerable pressure such that the transmitted pressure was far under the maximum value acceptable by the human skull. The present work also found that HICs exhibited by the investigated helmet prototypes fulfill all the practical guidelines as permitted by the Indonesian government. In terms of novelty, such innovation can be considered the first invention in Indonesia since the endorsement of the use of motorcycle helmets.

Matched MeSH terms: Water
Fulltext Comparative morphology and function of feeding appendages in food intake behaviour of the whiteleg shrimp, Litopenaeus vannamei, and the giant freshwater prawn, Macrobrachium rosenbergii

Kawamura, Gunzo, Bagarinao, Teodora Uy, Nur Syallinaz Seniman, Yong, Annita Seok-Kian, Lim, Leong-Seng

Borneo Journal of Marine Science and Aquaculture, 2018;2(1):26-39.
MyJurnal

Combining feeding appendage morphology and behavioural observation of the motion pattern of the feeding appendages clarified many aspects underlying the feeding processes of the giant freshwater prawn (Macrobrachium rosenbergii) and the marine whiteleg shrimp (Litopenaeus vannamei) in aquaria. The food intake behaviour was video recorded during eating pellet food, and pieces of fresh squid and fish. While M. rosenbergiitook pellet one by one, L. vannamei picked up many pellets at one time and held them at the mouth with the 3rd maxilliped endopods and the 1st walking legs. Both species used the right chelate walking legs rather than the left walking legs to pick up the food. The 3rd walking legs of L. vannameiwere longest and heaviest among the chelate walking legs but their major role was not for feeding but for feeding contests often in the form of aggression. While M. rosenbergii easily crunched pellets by the mandibles, L. vannamei did not crunch pellets due to the softer and not so strong mandibles and frequently spat out them, indicating that the present hard pellets are not suitable for L. vannamei. Both the species kept a piece of elastic fresh squid or fish flesh at the mouth and tore the food into small pieces with the help of repeated pulling down motion of the 3rd maxilliped endopods. However, the mandible teeth of the two spices were not sharp enough to gnaw off the fibrous muscle in one bite. The 2nd and 3rd maxilliped endopods were used for holding food at the mouth and did not contribute to mastication of food. The 2nd and 3rd maxilliped exopods exhibited the horizontal fanning motion, which caused a unidirectional water flow moving backwards in the gill chamber (visualized with milk). The maxilliped exopods were found to contribute not to feeding but ventilation. Based on the results obtained, development of softer pellets was recommended for L. vannamei.

Matched MeSH terms: Fresh Water
Fulltext Antifouling Properties of PES Membranes by Blending with ZnO Nanoparticles and NMP⁻Acetone Mixture as Solvent

Ahmad AL, Sugumaran J, Shoparwe NF

Membranes (Basel), 2018 Dec 14;8(4).
PMID: 30558199 DOI: 10.3390/membranes8040131

In this study, the antifouling properties of polyethersulfone (PES) membranes blended with different amounts of ZnO nanoparticles and a fixed ratio of N-methyl-2-pyrrolidone (NMP)-acetone mixture as a solvent were investigated. The properties and performance of the fabricated membranes were examined in terms of hydrophilicity, porosity, pore size, surface and cross-section image using scanning electron microscopy (SEM), surface roughness using atomic force microscopy (AFM), pure water flux, and humic acid filtration. Addition of ZnO as expected was found to improve the hydrophilicity as well as to encourage pore formation. However, the agglomeration of ZnO at a higher concentration cannot be avoided even when dissolved in a mixed solvent. The presence of highly volatile acetone contributed to the tight skin layer of the membrane which shows remarkable antifouling ability with the highest flux recovery ratio and negligible irreversible fouling. ZnO NPs in acetone/NMP mixed solvent shows an improvement in flux and rejection, but, the fouling resistance was moderate compared to the pristine membrane.

Matched MeSH terms: Water
Antibacterial activity of quaternized chitosan modified nanofiber membrane

Cheah WY, Show PL, Ng IS, Lin GY, Chiu CY, Chang YK

Int J Biol Macromol, 2019 Apr 01;126:569-577.
PMID: 30584947 DOI: 10.1016/j.ijbiomac.2018.12.193

The electrospinning PAN nanofiber membrane (P-CN) was hydrolysed to convert carboxylic groups as reaction sites and covalently graft chitosan molecule. The chitosan derivatives with quaternary ammonium groups exerted greater efficiency against bacteria as compared to pure chitosan. Hence, the chitosan modified membrane (P-CS), can be functionalized with quaternary amine (i.e., glycidyl trimethyl ammonium chloride, GTMAC) to form quaternized chitosan nanofiber membrane (designated as P-HTCC) under various conditions (acidic, neutral, and alkaline). N-quaternized derivatives of chitosan modified membrane (N-HTCC) showed 72% and 60% degree of quaternization (DQ) under acidic and neutral conditions, respectively. Under alkaline condition, additional quaternization of N, O-HTCC via its amino and hydroxyl groups, has improved up to 90% DQ of the chitosan. The antibacterial activity of the quaternized chitosan modified membrane prepared from acetic acid medium is stronger than that prepared from water and alkaline media. Also, antibacterial activity of quaternized chitosan is stronger than chitosan modified membrane against E. coli. The microbiological assessments showed that the water-stable P-HTCC nanofiber membrane under modification in acidic medium exerted antibacterial activity up to 99.95% against E. coli. Therefore, the P-HTCC membrane exhibited high potential to be integrated into microfiltration membrane to effectively disinfect E. coli.

Matched MeSH terms: Water
Mango leaf extract incorporated chitosan antioxidant film for active food packaging

K R, G B, Banat F, Show PL, Cocoletzi HH

Int J Biol Macromol, 2019 Apr 01;126:1234-1243.
PMID: 30584938 DOI: 10.1016/j.ijbiomac.2018.12.196

Health hazards associated with usage of plastic films for food preservation demands for development of active films from non-toxic and antioxidant rich bio-sources. The reported work highlights the development, characterization and application studies of chitosan films enhanced for their antioxidant activity by mango leaf extract (MLE) incorporation. Effect of MLE variation (1-5%) on the morphology, optical nature, water exposure and mechanical characteristics of the chitosan-MLE composite films was studied. Increase in the MLE concentration resulted in films with increased thickness and decreased moisture content. Contact angle, water solubility and vapor permeability analysis demonstrated the reduced hydrophilicity and water vapor penetrability of the films due to MLE inclusion. MLE films possessed better tensile strength (maximum of 23.06 ± 0.19 MPa) with reduced elongation ratio than the pure chitosan film (18.14 ± 0.72 MPa). Antioxidants assessment in terms of total phenolic content, DPPH radical scavenging, ferric reducing power and ABTS radical scavenging showed improved antioxidant activity with the incremental amounts of MLE in the chitosan films. Microscopic studies revealed the smooth, compact and dense nature of the MLE-chitosan films favouring low oxygen transport rates. Application studies to cashew nuts preservation for 28 days storage indicated 56% higher oxidation resistance for the 5% MLE film than a commercial polyamide/polyethylene film. Results highlight the potential and promising nature of MLE impregnated chitosan films as suitable alternative for active packaging films for food preservation.

Matched MeSH terms: Water
Fulltext Borneo coral reefs subject to high sediment loads show evidence of resilience to various environmental stressors

Browne N, Braoun C, McIlwain J, Nagarajan R, Zinke J

PeerJ, 2019;7:e7382.
PMID: 31428541 DOI: 10.7717/peerj.7382

For reefs in South East Asia the synergistic effects of rapid land development, insufficient environmental policies and a lack of enforcement has led to poor water quality and compromised coral health from increased sediment and pollution. Those inshore turbid coral reefs, subject to significant sediment inputs, may also inherit some resilience to the effects of thermal stress and coral bleaching. We studied the inshore turbid reefs near Miri, in northwest Borneo through a comprehensive assessment of coral cover and health in addition to quantifying sediment-related parameters. Although Miri's Reefs had comparatively low coral species diversity, dominated by massive and encrusting forms of Diploastrea, Porites, Montipora, Favites, Dipsastrea and Pachyseris, they were characterized by a healthy cover ranging from 22 to 39%. We found a strong inshore to offshore gradient in hard coral cover, diversity and community composition as a direct result of spatial differences in sediment at distances <10 km. As well as distance to shore, we included other environmental variables like reef depth and sediment trap accumulation and particle size that explained 62.5% of variation in benthic composition among sites. Miri's reefs showed little evidence of coral disease and relatively low prevalence of compromised health signs including bleaching (6.7%), bioerosion (6.6%), pigmentation response (2.2%), scars (1.1%) and excessive mucus production (0.5%). Tagged colonies of Diploastrea and Pachyseris suffering partial bleaching in 2016 had fully (90-100%) recovered the following year. There were, however, seasonal differences in bioerosion rates, which increased five-fold after the 2017 wet season. Differences in measures of coral physiology, like that of symbiont density and chlorophyll a for Montipora, Pachyseris and Acropora, were not detected among sites. We conclude that Miri's reefs may be in a temporally stable state given minimal recently dead coral and a limited decline in coral cover over the last two decades. This study provides further evidence that turbid coral reefs exposed to seasonally elevated sediment loads can exhibit relatively high coral cover and be resilient to disease and elevated sea surface temperatures.

Matched MeSH terms: Water Quality
Fulltext Development of Nano-SiO2 and Bentonite-Based Mortars for Corrosion Protection of Reinforcing Steel

Karunarathne VK, Paul SC, Šavija B

Materials (Basel), 2019 Aug 17;12(16).
PMID: 31426501 DOI: 10.3390/ma12162622

In this study, the use of nano-silica (nano-SiO2) and bentonite as mortar additives for combating reinforcement corrosion is reported. More specifically, these materials were used as additives in ordinary Portland cement (OPC)/fly ash blended mortars in different amounts. The effects of nano-silica and bentonite addition on compressive strength of mortars at different ages was tested. Accelerated corrosion testing was used to assess the corrosion resistance of reinforced mortar specimens containing different amounts of nano-silica and bentonite. It was found that the specimens containing nano-SiO2 not only had higher compressive strength, but also showed lower steel mass loss due to corrosion compared to reference specimens. However, this was accompanied by a small reduction in workability (for a constant water to binder ratio). Mortar mixtures with 4% of nano-silica were found to have optimal performance in terms of compressive strength and corrosion resistance. Control specimens (OPC/fly ash mortars without any additives) showed low early age strength and low corrosion resistance compared to specimens containing nano-SiO2 and bentonite. In addition, samples from selected mixtures were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Finally, the influence of Ca/Si ratio of the calcium silicate hydrate (C-S-H) in different specimens on the compressive strength is discussed. In general, the study showed that the addition of nano-silica (and to a lesser extent bentonite) can result in higher strength and corrosion resistance compared to control specimens. Furthermore, the addition of nano-SiO2 can be used to offset the negative effect of fly ash on early age strength development.

Matched MeSH terms: Water
Effects of environmental conditions and nutrients on the occurrence and distribution of potentially harmful phytoplankton in mesotrophic water

Soon TK, Julian Ransangan

Sains Malaysiana, 2016;45:865-877.

Marudu Bay, north coast of Sabah is characterized with mesotrophic water body and typical environmental parameters
throughout the year. The current study was undertaken to evaluate the effect of environmental parameters and nutrients
in mesotrophic water on the occurrence and distribution of potentially harmful phytoplankton species. The samplings
were conducted over a period of thirteen months, covering southwest monsoon (SWM), inter-monsoon (IM), and northeast
monsoon (NEM), at ten stations throughout the bay. Physical parameters (temperature, salinity, pH, dissolved oxygen,
current speed and secchi depth), biological parameters (cell densities of phytoplankton) and chemical parameters
(phosphate, nitrate, silicate and ammonia) were examined. The results indicated at least eight potentially harmful
phytoplankton species (Dinophysis caudata, D. miles, Ceratium furca, C. fursus, Prorocentrum micans, P. sigmoides, P.
triestinum and Pseudo-nitzschia sp.) were detected in north coast of Sabah. However, the potentially harmful phytoplankton
species contributed only about 1.3% of the total phytoplankton community. Under nutrient deprivation conditions, the
potentially harmful phytoplankton species distribution was mainly influenced by the ability to utilize other nitrogen
sources, cell mobility and toleration to low nutrients environments.

Matched MeSH terms: Water
Rapid extraction of bisphenol a by dispersive liquid-liquid microextraction based on solidification of floating organic

Shan TO, Mee LN, Marinah Mohd Ariffin, Saw HL

Sains Malaysiana, 2017;46:615-621.

Bisphenol A is an endocrine disruptor with widespread applications, especially in the production of polycarbonate and epoxy resins. Dispersive liquid-liquid microextraction based on solidification of floating organic technique has been developed for the extraction of bisphenol A from water and soft drink. The 1-undecanol has been applied as the extraction solvent because of its low density and melting point and high affinity to the analyte. The technique offered rapid and simple analysis as the 1-undecanol was homogeneously dispersed in the sample solution to speed the extraction and the collection of extraction solvent was simplified by centrifugation, cooling and melting steps.

Matched MeSH terms: Water
Effect of gamma irradiation on the physical stability of dppc liposomes

Liyana Mohd Ali Napia, Faizal Mohamed, Hur Munawar Kabir Mohd, Intan Syakeela Ahmad Bastamam, Shamellia Sharin, Norsyahidah Mohd Hidzir, et al.

Sains Malaysiana, 2018;47:1235-1240.

Unilamellar liposomes composed of dipalmitoylphosphatidylcholine (DPPC) were prepared by the reverse-phase
evaporation method and extrusion through a polycarbonate membrane filter. Liposomes at 0.7 mg/mL lipid concentration
in deionized water were exposed to gamma irradiation at a dose in the range 0.5 to 25 kGy. Gamma irradiation of
liposomes resulted in the degradation of DPPC lipids into free fatty acids, lysophosphatidylcholine and 1,2-palmitoylphosphatidic
acid (DPPA). The effect of gamma irradiation towards the physical stability of liposomes was investigated
by means of dynamic light scattering (DLS), transmission electron microscopy (TEM) and zeta potential analysis. From
the DLS analysis, no significant changes were observed in the hydrodynamic size of liposomes. TEM images indicate that
the liposomes surface became smoother and rounder as higher irradiation doses were applied. Zeta potential analysis
showed that gamma irradiation of DPPC liposomes at radiation doses as low as 0.5 kGy resulted in a drastic rise in the
magnitude of the zeta potential. The results also demonstrate that gamma irradiation of liposomes suspension enhanced
the overall stability of liposomes. Hence, it can be concluded that gamma irradiation on DPPC liposomes may potentially
produce liposomes with higher stability.

Matched MeSH terms: Water
Immobilization of bovine serum albumin on the chitosan/PVA film

Nurul Mujahidah Ahmad Khairuddin, Amalina Muhammad Afifi, Katayoon Kalantari, Nur Awanis Hashim, Shaza Eva Mohamad

Sains Malaysiana, 2018;47:1311-1318.

Chitosan/polyvinyl alcohol (Chitosan/PVA) blended film was prepared by direct blend process and solution casting methods.
In order to reduce the swelling ratio and enhance the chemical and mechanical stability, Chitosan/PVA film was crosslinked
with glutaraldehyde in order to produce Chitosan-g-PVA. Bovine serum albumin (BSA) was used as a model protein
to incorporate into the Chitosan-g-PVA. The chemical structure and morphological characteristics of films were studied
by FT-IR and scanning electron microscopy (SEM). Mechanical and physical properties of blended films such as tensile
properties in the dry and wet states, water uptake and water contact angle measurement were characterized. Blending
PVA and chitosan improved strength and flexibility of the films. Crosslinking with glutaraldehyde further improves the
tensile strength and decrease the hydrophilicity of films. BSA immobilized on the Chitosan-g-PVA film was calculated as
BSA encapsulation efficiency.

Matched MeSH terms: Water
Fulltext Sensory quality and flavour of alginate coated and repetitive pulsed light treated fresh-cut cantaloupes (Cucumis melo L. Var. Reticulatus Cv. Glamour) during storage

Koh PC, Noranizan MA, Karim R, Nur Hanani ZA

J Food Sci Technol, 2019 May;56(5):2563-2575.
PMID: 31168138 DOI: 10.1007/s13197-019-03739-0

Fresh-cut fruits are popular due to the convenience provided. However, fresh-cut processes damage fruit tissues and reduce the shelf life of products. Pulsed light (PL) treatment is a decontamination method of foods. PL treatment given repetitively at a certain interval during storage could further extend the shelf life of fresh-cut fruits. Edible coating preserves fresh-cut fruits by providing mechanical strength and reducing respiration and water loss. This study was to evaluate the effects of alginate coating combined with repetitive pulsed light (RPL) on sensory quality and flavour of fresh-cut cantaloupes during storage. Cantaloupes were treated with alginate (1.86%, w/v) and RPL (0.9 J/cm2 at every 48 h up to 26 days) alone or in combination. Flavour analysis of fresh-cut cantaloupes was carried out every 12 days during storage at 4 ± 1 °C while sensory analysis was performed on day 32. Alginate coating and/or RPL retained sugar contents (17.92-20.01 g/kg FW for fructose, 18.77-19.98 g/kg FW for glucose and 23.02-29.41 g/kg FW for sucrose) in fresh-cut cantaloupes during storage. Combination of alginate with RPL reduced accumulation of lactic acid although alginate coating was more effective to minimise changes of other organic acids in fresh-cut cantaloupes. The combined treatment was also more effective than individual treatment in retaining total aroma compound concentration of fresh-cut cantaloupes during storage with the highest relative concentration, i.e. 3.174 on day 36. Overall, the combined alginate coating and RPL was effective to maintain the fresh-like sensory quality of fresh-cut cantaloupes with insignificant overall acceptability compared to the control.

Matched MeSH terms: Water

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links