Many studies have shown that probiotic strains added to a number of probiotic products are not compatible to that of
claimed. It is thus of note to validate probiotic strains added to probiotic products. In this study, three probiotic drinks,
A, B and C, were cultured on MRS agar and the number of bacterial colonies was enumerated. The bacterial counts
recovered from A (9.3 ± 6.9 log CFU/ml) and C (9.0 ± 6.9 log CFU/ml) were signifi cantly higher than B (5.2 ± 3.5 log
CFU/ml) and achieved the minimal amount recommended for probiotic bacteria. All of the isolates appeared as gram
positive rods microscopically and were proven to be catalase negative. However, there were only A1, A2, B4 and C1 that
were highly tolerant to the gastrointestinal pH 3 to 6. The four isolates produced and secreted antimicrobial substances
which inhibited the growth of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). C1 showed the greatest
growth inhibition by forming 17.50-mm and 17.85-mm inhibition zones against E. coli and S. aureus, respectively. The
16s rDNA sequencing and phylogenetic analysis were performed to further identify the twelve isolates. The twelve isolates
were found to be Lactobacillus (L.), particularly L. casei and L. paracasei. However, the bacteria isolated from drink B
were incompatible to the labelled ones. In conclusion, probiotic drinks are possible to contain different bacterial counts
and probiotic strains from the labelled ones. These differences might affect health benefi ts rendered by probiotic strains
to consumers.
Ocular abnormalities have apparent effects on brain activation. However, neuroimaging data about the ocular characteristics of healthy participants are still lacking to be compared with data for patients with ocular pathology. The objective of this multiple participants’ functional magnetic resonance imaging (fMRI) studies was to investigate the brain activation characteristics of healthy participants when they view stimuli of various shapes, pattern and size. During the fMRI scans, the participants view the growing ring, rotating wedge, flipping hour glass/bow tie, quadrant arc and full checker board stimuli. All stimuli have elements of black-and-white checkerboard pattern. Statistical parametric mapping (SPM) was used in generating brain activation via fixed-effects (FFX) and conjunction analyses. The stimuli of various shapes, pattern and size produce different brain activation with more activation concentrated in the left hemisphere. These results are supported by the conjunction analysis which indicated that the left pre-central, post-central, superior temporal and occipital gyrus as well as the left cingulate cortices were involved when the participants viewed each given stimulus. Differential activation analysis showed activation with high specificity in the occipital region due to the stimuli of various shapes, pattern and size. The activation in the right middle temporal gyrus was found to be significantly higher in response to moving stimuli as compared to stationary stimuli. This confi rms the involvement of the right middle temporal gyrus in the observation of movements. The black-and-white checkerboard stimuli of various shapes, pattern and size, stationary and moving was found to 1) activate visual as well as other cortices in temporal and parietal lobes, 2) cause asymmetry in brain function and 3) exhibit functional integration characteristics in several brain areas.
Keywords: fMRI; SPM; visual stimulus; occipital gyrus; middle temporal gyrus
The purpose of this study was to examine the effect of stimulus sweep direction on the fine structure of the 2f1-f2 distortion product otoacoustic emission (DPOAE). It was hypothesised that the DPOAE fine structure could be shifted if the stimulus sweep changed from one direction to the other. In the present study, ascending, descending and random frequency sweeps were used, with f2 frequency varying between 992 Hz and 2496 Hz and f2/f1 fixed at 1.22. DPOAE fine structure was recorded at 16 Hz intervals. Screening, spontaneous otoacoustic emission (SOAE) and DPOAE measurements were carried out on 19 ears of 19 subjects aged between 22 and 30 years. Data from 14 ears that had at least one significant peak or valley in their DPOAE fine structure were included in the main analysis. Of these, five ears showed at least one occurrence of SOAE over the frequency span 600 Hz to 2500 Hz. Data for ears with and without SOAEs were grouped and analysed separately. The results showed no effect of sweep direction on DPOAE fine structure. No significant differences were observed in peak or valley frequencies, peak height or valley depth between the three stimulus sweep conditions (p > 0.05). There was also no significant effect of stimulus sweep direction on DPOAE level at the point at which SOAE frequency equalled DPOAE frequency (p > 0.05). In conclusion, the study found no effect of stimulus sweep direction on the fine structure of the 2f1-f2 DPOAE, either in ears with or without SOAEs. Therefore, future measurements of this fine structure may use either sweep direction.
This paper outlines the past five decades of scientific interests and advances in medicinal plant research in Malaysia. Initially the prime interest of research programmes has been on phytochemical studies leading to the discovery of biologically active compounds as chemical templates to produce new drug candidates. As the Malaysian herbal medicine market experiences an extraordinary growth, the research approaches taken have recently included activities to develop herbal medicines into quality, efficacious and safe products for human consumption. Advances in chromatographic and spectroscopic techniques have had a tremendous impact on the isolation and structure elucidation of the constituents of medicinal plants. The development of a series of bioassay methodologies and utilization of bioassay-guided isolation techniques have contributed significantly to the progress of medicinal plant research in Malaysia. Research work on some medicinal plants carried out by the local scientists will be illustrated as examples.
There has been a significant increase in research on probiotics-associated health benefits in the last 20 years. Many studies carried out in vitro and clinically show that consumption of probiotics inhibits the growth of pathogenic microorganisms. Furthermore, the consumption of probiotics also enhances the host immune response and decreases the levels of carcinogenesis-inducing enzymes. These positive outcomes have led to the use of probiotics in prevention and treatment of infectious diseases like bacterial or antibiotic associated diarrhea, chronic inflammatory bowel diseases and colon cancer. This review summarises literature pertaining to mechanistic actions of probiotics in improving the well-being of hosts.
Heschl’s gyrus (HG) is known to interact with other auditory related areas of the same hemisphere during the performance
of an auditory cognitive task. However, the information about how it interacts with the opposite HG is still lacking.
The aim of this study was to investigate the psychophysiologic interaction (PPI) between the bilateral HG during a
simple arithmetic addition task and to verify the role of noise as an experimental factor that would modulate the PPI.
Functional magnetic resonance imaging (fMRI) scans were performed on eighteen healthy participants, in which a
single-digit addition task were solved during in-quiet (AIQ) and in-noise (AIN) conditions. The fMRI data were analysed
using Statistical Parametric Mapping (SPM8). The interaction between the bilateral HG was investigated using PPI
analysis. The response in right HG was found to be linearly influenced by the activity in left HG, vice-versa, for both
in-quiet and in-noise conditions. The connectivity from right to left HG in noisy condition seemed to be modulated
by noise, while the modulation is relatively small oppositely, indicating a non-reciprocal behavior. A two-way PPI
model between right and left HG is suggested. The connectivity from right to left HG during a simple addition task in
noise is driven by a higher ability of right HG to perceive the stimuli in a noisy condition. Both the bilateral HGs took
part in the cognitive processes of arithmetic addition from which the interactions between the two were found to be
different in noise.
The emergence of research about the biological effects of electromagnetic field (EMF) have growing concern among
researchers. The aim of this study was to investigate the effects on the brain of rats periodically exposed to 0.1 mT EMF.
Total 24 adult male Sprague Dawley rats were subdivided randomly to 4 groups: 2 control groups (C1 6 hours: 6 h/
day for 5 days; C2 20 hours: 20 h/day for 5 days) and 2 treatment groups which exposed to 0.1 mT EMF (T1 6 hours:
6 h/day for 5 days; T2 20 hours: 20 h/day for 5 days). A significant decrease in the pyramidal cell number was higher
as the exposure duration to EMF was extended (T1, p
The microstructural evolution of Sn-40Pb/Cu joints has been investigated under 125 o C thermal exposure conditions using single shear lap joints. A scanning electron microscope (SEM) was used to observe the morphology of the phases and energy dispersive x-ray (EDX) was used to estimate the elemental compositions of the phases. A double layer of Cu6Sn5 and Cu3Sn were observed. The Cu6Sn5 developed with a scalloped morphology, while the Cu3Sn always grew as a somewhat undulated planar layer in phase with the Cu6Sn5. The Cu6Sn5 layer began to transform from scallop shape to planar type after aging for 375 hours due to reduction in the interfacial energy. The intermetallic layers showed a linear dependence on the square root of aging time. The growth rate constant of the intermetallic compounds are estimated as 15.2 x 10 - 14 and 0.152 x 10 -14 cm 2 /s for Cu6Sn5 and Cu3Sn intermetallic, respectively.
Silicon nanostructures have successfully been synthesized by thermal evaporation technique using nickel catalyst. Silicon powder served as starting source material was evaporated at high temperature (900-1100°C) in inert carrier gas. The grown silicon nanostructures were collected on (111) silicon substrate surface that positioned at varied location from source material. By controlling heating rate, gas flow rate, growth temperature and time, substrate position and location; to the optimum condition produced the best quality at silicon nanostructures. In this work, the best parameter to produce silicon nanostructures is system ramping up 1000°C at 20°C/min heating rate, N2 flow at 100ml/min; silicon needle-like one dimensional silicon nanostructures growth on vertically-positioned substrate located at 12cm from source material for 1 hour growth time. The effects of these parameters on the structures and physical of nanostructures were characterized by field emission scanning electron microscope and x-ray diffraction.
The presence of 226 Ra in water is a great concern in human life since it can cause health risk to a certain extent. In the state of Kelantan, being known of its granitic area, there is a lack measurement of 226 Ra content in river water, since water is the major source of water supply. According to the INTERIM National Water Quality Standards for Malaysia (INWQS), 226 Ra activity concentration in water cannot exceed 0.1 Bq/L. For this reasons, this research was planned to carry out a systematic measurement of water along Sungai Kelantan. Liquid Scintillation Counting was used for measurement of 226 Ra in water samples from Sungai Kelantan mainly in district of Kuala Krai. In this paper, the results obtained is about 26 water samples, filtered and unfiltered, collected along Sungai Lebir, Sungai Sok and Bukit Sabah. Thus, the assessment activity concentration of 226 Ra in river water was obtained as well as annual effective dose for consumption of drinking water.
Natural radionuclides such as 210 Po and 210 Pb were analyzed in soft part of cockle (Anadara granosa) obtained from Kuala Selangor in the west coast Peninsular of Malaysia. The activity levels of both nuclides fluctuated within the size of cockles from 41.3 ± 2.5 Bq/kg to 114 ± 7 Bq/kg and 12.9 ± 1.7 Bq/kg to 96.8 ± 5.3 Bq/kg in dry weight (dwt) for 210 Po and 210 Pb, respectively. The level activity in wet weight (wwt) also varied from 8.60 ± 0.52 Bq/kg to 25.70 ± 1.63 Bq/kg and 2.47 ± 0.40 Bq/kg to 19.27 ± 1.05 Bq/kg for 210 Po and 210 Pb, respectively, probably related to the different of metabolic rate and growth of cockles. Activity ratio of 210 Po/ 210 Pb in dry weight also fluctuated from 0.93 to 6.41 with not related to the decay of 210 Pb.
Texture evolution of NiO formed during oxidation of polycrystalline single oriented (100) Ni-Cr was investigated. This foil was also termed rolling assisted biaxially textured substrate (RABiTS). X-ray diffractograms of oxidized Ni-Cr RABiTS foil showed the existence of mostly (200) NiO indicating (100)-type NiO formed exclusively on (100) singly oriented Ni-Cr grains. Epitaxial relationship between the two layers is observed. However the dual-in-plane texture was recorded.
The in-plane texture was assessed by conducting phi scan and plotting series of pole figures measured at (111) NiO peak. The mechanism of the oxides formation was proposed to take into account the formation of (100)-type NiO. Cross section morphology of the oxidised foils reveals two oxidation layers; fast growing external layer consisting of the (100)-type NiO and an internal layer consisted of mostly Cr2O3 and maybe NiCr2O4. The thickness of NiO was ~ 10Pm. Cr2O3 formed as needle-like oxides embedded in a matrix of Ni foil. Inward diffusion of oxygen is believed to have caused this to happen. The external NiO layer was consisted of duplex microstructure characterised by columnar layer growing vertical on the surface of the metal and a few micron thick of equiaxed NiO. Delamination of the outer NiO layer often occurred at the columnarequiaxed interface which could be cured by CeO2 deposition on the foil prior to the oxidation process. CeO2 was deposited by conversion immersion using Ce(NO3)3.6H2O solution. (200) NiO formed on this coated sample as well.
We put attention on Intrinsic Josephson Junction (IJJ) to study the fundamental physic for device applications. Convenient self-flux method was used to grow BSCCO single crystals. We investigated the lid effect to examine the single crystal growth of high TC (Critical Temperature). We found that for the crystal growth with no lid, two stage transitions of TC ≅ 61 K and 77 K were observed. While for the crystal growth with lid, the BSCCO has TC ≅ 80K, ΔTC = 10K and approximately average size5x2mm 2 . When we increased weight of lid, the single crystal have increased to TC =80K, ΔTC = 4K and the typical size was ≅7x3mm 2 . TC and the crystal growth show a tendency to increase by the effect of the lid. From observed quasi-particle characteristics, c-axis direction changed from semiconductor to intrinsic Josephson characteristic with decreasing temperature.
Ceramic of BaxSr1-xTiO3 (BST) for x =0.3; 0.5 and 0.7 were successfully deposited by solid solution method. The BST ceramic were analyzed by x-ray diffraction (XRD). The XRD spectra was recorded on a Philips type PW 3701 diffractometer using CuKD (Oco = 1.54056 Å) radiation at 30 KV and 30 mA (900 watt). The spectra shows that BST ceramic are polycrystalline with tetragonal structure. The lattice constants analysis of the grown ceramics was analyzed by visual basic program. Using Cohen’s and Cramer’s algorithms in visual basic program, , the lattice constants are a = b = 3.877 Å; c = 3.970 Å for Ba0.3Sr0.7TiO3 ceramic, a = b = 3.979 Å; c = 3.981 Å. for Ba0.5Sr0.5TiO3 ceramic and a = b = 3.965 Å; c = 4.005 Å for Ba0.7Sr0.3TiO3 ceramic, respectively. The reform value of the lattice constant of BST ceramic is possibly associated with the anti site defects of Ba and Sr.
There are many essential and non-essential elements including metals and radionuclides present in vegetables. Howeve r, the accumulation of the several metals and radionuclides might cause the contamination to vegetables itself. Green m ustard (Brasissca rapa var. Parachinesis L.) was selected to represent the vegetable in this study. Objectives of this stud y are to determine the concentration of metals and radionuclides in the samples and to calculate the enrichment factor ( EF) and also to estimate the uptake, base on biological accumulation coefficient (BAC), for the various parts of selecte d vegetables. Three farmlands in the Cameron Highlands were studied namely Bharat, Kg Raja and Bertam area. The g reen mustard and soil samples were collected during the harvest season. Samples were dried, ground and sieved prior t o analysis. Analyses for both samples were done by using X-rays Fluorescence Spectroscopy (XRF) to measure the conc entration of Fe, Zn, Hg, U and Th. The concentration of all elements in the soils is lower than their concentration in the control soil, except for Zn, U and Th. The concentration of all elements in Green Mustard is lower than their concentrat ion in the soil where it was grown. The EF values in the Brasissca rapa var. Parachinesis L are lower than 2 except for U and Th, indicating some degree of contamination due to anthropogenic activities or naturally origin. The BAC values show that Zn and Hg were accumulated in the green mustard, depending on where the plant grows.
Effects of cultural practice under different habitats, of well-managed monoculture plantation and growing wild under rubber trees, were studied in Aquilaria malaccensis (Karas) leaves. This study was carried out on Karas growing in these two habitats each from Lipis, Pahang and Sepang, Selangor areas in Malaysia; under the control and induced treatments. The parameters studied include wet and dry weight of 50 matured leaves, iron and zinc elemental contents in leaf, iron and zinc uptakes from soil, and leaf and soil moisture contents. Iron and zinc were analysed in Karas leaves and soil by using Instrumental Neutron Activation Analysis (INAA) technique.
Even though a lot of new advanced materials have been developed nowadays, steel remains a major material in construction, automobiles, appliances, industrial machinery as well as in the nuclear industry. Due to steel easily corroded, a proper surface protection is required to avoid any failures and extended the life cycle of the components. Surface coating is an efficient and economical method to obtain desirable material surfaces properties. Hot dip aluminizing technique was utilized in this study. Experiments have been conducted on the mild steel substrates with 12mm diameter. Prior to hot dipping process, observation on grain growth at three different temperatures had also been conducted to understand the behaviour of steel under application of heat. The substrates were heated at 700ºC, 800ºC and 900ºC for 1 hour and the microstructure was analyzed. The temperature of 800C was chosen for hot dipping. The substrates were dipped into the molten aluminum maintained at temperature 800ºC for 2,4,6,8,10,15 and 20 minutes. Optical microscopy and energy dispersive X-ray spectroscopy were used in this investigation. From the microstructure observation, it showed the appearance of intermetallic layer covered by the top layer of Al on the mild steel substrate increased with the increase in dipping time ranging from 36 to 282μm. The result of EDX analysis revealed the existence of Fe and Al in form of Fe2Al5 phase for all the dipping time.
Silicon nanowires were synthesized on Si substrates (111) via thermal evaporation using AuPd thin layer catalyst. Pre cleaned of Si wafer was used as a substrate to assemble the nanostructure products. In this work, the effect of growth temperature that ranging from 800 to 1000°C on the formation of silicon nanowires studied extensively. X-ray diffraction and field emission scanning electron microscope were employed to characterize the structures and morphology of nanowires. Vertical aligned silicon nanowires have been successfully grown on Si substrates at 900 and 1000°C. At 1100°C, the high aspect ratio of silicon nanowires can be produced but the formation density is low. The presence of AuPd catalyst on the tip of nanowires, it is expected that VLS is the most suitable to explain the growth mechanism of obtained SiNWs. The crystalline structure of SiNWs was proved by XRD data.
At present, research in composite materials is being directed at using natural fibres instead of synthetic fibres. Kenaf which is extensively grown in the Far East including Malaysia, has been identified as a bast (stem) fibre with significant market potential. In this work, long and random kenaf fibres (non-woven mat form) were used in the as-received condition and alkalized with a 0.06M NaOH solution. They were combined with polypropylene thin sheets, sandwiched between layers of kenaf fibres and hot-pressed to form natural fibre composites. The mechanical properties of the composites were investigated to observe the effect of fibre alignment, fibre treatment and pre-irradiation method used. A general trend was observed whereby alkalized and long fibre composites gave higher flexural modulus and flexural strength compared with random mat and untreated fibres. The long fibre composites also gave a higher work of fracture. However, the correlation between fibre surface treatment and the work of fracture was less clear. Pre-irradiation on the polypropylene pellets and fibres before the composite is manufactured showed significant improvement on the flexural modulus and flexural strength. The bond performance test performed on the treated composites demonstrated good bonding and interfacial adhesion between the fibre and matrix. However, the method of moulding used need to be improved to optimize the performance of the composites.
The state of Selangor, Malaysia, is facing a significant rise in the number of malaria cases with the incidence varying from 20 to 90 per 100,000 persons in a population. A study was carried out to describe the distribution of malaria cases in relation to the growing number of foreign workers in Selangor. Data were reviewed using the return forms "PBV (M) 101", a summary of malaria cases in Selangor for 2006 and Annual Reports of Vector-Borne Disease Control Unit, Selangor State Department for 2001- 2005. The malaria cases in Selangor varied between 172 cases in 2001 and 90 cases in 2006. Most of the cases were contributed by foreign workers, who were predominantly male of economically active age group and came from malaria endemic countries. Most of these cases were concentrated in the urban districts. Malaria is still endemic in Selangor. Malarial infection has the potential of contributing to an urban outbreak of malaria.