High sensitivity signal detection for a sparse temporal sampling (STS) functional magnetic resonance imaging (fMRI) is compensated by the increase in the number of scans (Ns) and consequently the scan time. A long scan time would result in fatigue and restlessness in participants, while a short scan time is undesirable for an STS-fMRI due to insufficient Ns for averaging. The purpose of this study was to determine the Ns practically sufficient for a sparse fMRI study. Eighteen participants were presented with white noise during a sparse fMRI scan. The height extent of activation was determined via t statistics and region of interest (ROI) based percentage of signal change (PSC). The t statistics and PSC for Heschl’s gyrus (HG) and superior temporal gyrus (STG) during which the participants listened to the white noise were calculated for different number of scans which were 6, 12, 18, 24, 30 and 36. The t statistics and PSC values calculated for the bilateral HG and STG qualitatively indicated a minimal change over Ns = 12 to 36. Both ROIs showed a consistent common right lateralization of activation for all Ns, indicating the right-hemispheric dominance of auditory cortex in processing white noise stimulus. It was proposed that for a sparse fMRI study, Ns may practically fall between 12 and 36
The present study was aimed at evaluating antihyperglycemic and antihyperlipidemic activity of nuciferin and
norcoclaurine constituents of N. nucifera seeds, a well-known medicinal plant. The alloxan (100 mg/kg b.w) induced
diabetic rats (200-250 g) were divided into seven groups (n = 6). Group I; normal control, Group II; diabetic control,
Group III; standard, Group lV-VII were fed with methanolic crude extracts (100, 200 mg/kg), nuciferin and norcoclaurine
(10 mg/kg b.w.), received for 15 days in dose dependent manner. The study included different parameters; examination of
oral glucose, fasting blood glucose, serum lipid profile and checking for body weight changes. In oral glucose examination,
within 60 and 80 min of treatment, extracts, nuciferin and norcoclaurine significantly reduced blood glucose (p<0.05)
and restored body weight in diabetic rats. Alloxan- induced diabetic rats showed 30-50% reduction of blood glucose
level (p<0.05) and recovered 5-20% body weight at day 15 after ingestion of crude extracts (100-200 mg/kg b.w.); and
nuciferin and norcoclaurine (each at 10 mg/kg b.w.). It also recovered significantly elevated biochemical parameters such
as triglycerides (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), total cholesterol (TC), serum urea and
creatinine. Our findings indicated that N. nucifera seeds possess significant antihyperglycemic and antihyperlipidemic
activity in diabetic rats.
Boron (B) is a mineral considered essential for improving sunflower (Helianthus annuus L.) resistance to drought. B supplements (0, 15-, 30- and 45 mg L-1) under well-watered and variable water deficit levels (64 and 53 mm irrigation depths) were evaluated for their effects on growth, oil quality and water use efficiency (WUE) in a field study for two consecutive years (i.e. 2011 and 2012). The duration of 50% inflorescence emergence, 50% flowering and 50% maturity stages were reduced with increasing moisture stress. All B application rates improved sunflower growth compared to no B control treatment. The moisture deficit treatments of 64 and 53 mm irrigation depths significantly (p<0.05) reduced the yield-related components. Achenes/head, achenes weight and achene yield under water stress conditions were considerably improved by foliar application of B at 30 mg L-1. An increase in protein contents and a decrease in oil contents were observed with B foliar application under moisture deficit treatments. Foliar application of B (30 mg L-1) on water stressed plants also resulted in increased WUE. The highest net benefits were achieved with B concentration of 30 mg L-1 under well-watered and mild deficit water level of 64 mm irrigation depth. The highest application rate of B (45 mg L-1) gave the best results at the most severe water deficit level. In conclusion, the B rates of 30 and 41 mg L-1 performed best for improving drought tolerance in terms of higher sunflower productivity under mild and higher water deficit conditions
MeSH terms: Body Weight; Boron; Dehydration; Helianthus; Minerals; Water; Dietary Supplements; Droughts; Inflorescence; Water Wells
This study evaluates the current environmental influences on fish assemblages of the upper Sungai Pelus, Kuala Kangsar, Perak. Fish samplings and habitat characterizations were conducted at three significant different months, which were on dry (June 2014), wet (August 2014) and moderately wet seasons (April 2015). A total of 510 individual fish were collected from the study, which consist of four orders, nine families, 20 genus and 21 species of fishes. Cyprinidae was the biggest family, followed by Bagridae, Balitoridae and Sisoridae. Neolissochilus hexagonolepis was the only species documented under the nearly threatened list, even their individual number and occurrences were the highest recorded. The readings of environmental variables, such as water temperature, pH, conductivity, dissolved oxygen, total dissolved solids, biological oxygen demand and total suspended solids were regarded as normal for upper river area. However, the water turbidity and chemical oxygen demand (COD) were quite high, which we believed was due to seasonal variation and current anthropogenic activities of the nearby river area. Canonical correspondence analysis showed that the water conductivity, river width, COD and water velocity were the main factors in influencing the fish assemblages of this upper Sungai Pelus. The findings can be utilized as a guideline to manage, protect and conserve this upper river area in the near future.
In this study, the adsorption efficiency of methyl violet (MV) dye onto Ce0.3Al0.7 and Ce0.3Al0.7Agx (x = 0.1, 0.3 & 0.5) mixed oxides was investigated. The properties of mixed oxide were determined by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), N2 adsorption-desorption isotherm, diffuse reflectance UV-vis spectroscopy (UV-vis DRS) and X-ray absorption near edge structure (XANES). Characterization showed that synthesized mixed oxide with fluorite has a pure cubic structure of a mesoporous nature and a small grain size with rough surface. Batch adsorption experiments were used to study parameters including contact time and initial dye concentration. The results showed that these parameters affected the degree of MV dye adsorption. The dye adsorption of mixed oxides attained equilibrium at 120 min. The equilibrium adsorption data were analyzed using Langmuir, Freundlich and Temkin isotherms. The adsorption behavior of MV dye onto Ce0.3Al0.7 was found to follow the Langmuir isotherm (R2 = 0.9951), providing a maximum monolayer adsorptive capacity of 2.35 mg/g. Alternatively, the adsorption of MV dye onto Ce0.3Al0.7Ag0.1 (R2 = 0.7839), Ce0.3Al0.7Ag0.3 (R2 = 0.9301) and Ce0.3Al0.7Ag0.5 (R2 = 0.9396) followed the Freundlich isotherm. The possible adsorption mechanisms of MV dyes onto the Ce0.3Al0.7 and Ce0.3Al0.7Agx were also discussed.
Polyhydroxybutyrate (PHB) otherwise known as bioplastics are biodegradable materials that are accumulated in various microorganisms to serve as carbon and energy reservoirs and regarded as an attractive alternative to petroleum-derived plastics. Although research has been conducted on isolation of PHB-producing microorganisms from different ecological environments, few studies have been carried out on isolation of potential PHB-producing microorganisms from rhizosphere environment of groundnut plants, Arachis hypogaea which can be regarded as a good environment for the isolation of potential PHB-producing microorganisms. In the present study, a total of twenty-one (21) bacterial strains were primarily screened and isolated from rhizosphere soil of a groundnut plant. Four bacterial isolates with maximum PHB-producing potential upon screening using submerged fermentation were selected for further studies. The fermentation pattern of PHB production was studied using different nutrient sources. The influence of agitation on PHB production was also studied. Mannitol stimulated maximum (6.076a mg/mL) PHB production by Bacillus sp. 1; KNO3 used as a limiting nutrient induced best (5.728a mg/mL) PHB production by Citrobacter sp. and MgSO4.7H2O supported maximum (5.972a mg/mL) PHB production in Enterococcus sp. A low agitation speed of 150 rpm was found to support best (5.802a mg/mL) PHB production by Bacillus sp.1. Findings from this study indicated that the isolated bacterial strains have high PHB- producing potential. The need to explore other environment harbouring microbial strains with high PHB-producing potential is paramount to the discovery of bioplastics with improved properties for potential industrial applications.
The transesterification of Thevetia peruviana seed oil with dimethyl carbonate (DMC) for preparing biodiesel has been studied using as an active catalyst potassium-methoxide (KOCH3). The effects of reaction conditions: Molar ratio of dimethyl carbonate to Thevetia peruviana seed oil, catalyst concentration, reaction time and agitation speed on dimethyl esters (DMC-Tp-BioDs) yield were investigated. The highest DMC-Tp-BioDs yield could reach 97.1% at refluxing temperature for 90 min with molar ratio of DMC-to-oil 5:1 and 2.0% w/w KOCH3 (based on oil weight). The fuel properties of the produced DMC-Tp-BioDs were compared with the ASTM D6751-02 biodiesel standard.
A simple and fast dispersive liquid-liquid microextraction (DLLME) technique using organic solvent lighter than water has been developed for the extraction of selected polycyclic aromatic hydrocarbons in green tea, chrysanthemum tea and coffee beverage. The 1-octanol and acetonitrile were pre-mixed and injected into the sample solution. After dispersing, the cloudy solution was subjected to centrifugation to separate the solution into 2 phases, where the micro-droplet of 1-octanol was clearly floated on the top layer. The 1-octanol extract was then diluted and injected into high performance liquid chromatography-fluorescence for the quantitative analysis. The technique offered rapid analysis as the 1-octanol was homogeneously dispersed in the sample solution thus speeding the analytes diffusion. Under the optimized extraction conditions, the technique achieved trace detection limits in the range of 0.001 to 0.3 μgL-1 for the targeted analytes, namely phenanthrene, fluoranthene and benzo[a]pyrene. The method was successfully applied to the spiked green tea, chrysanthemum tea and coffee beverage samples with good average relative recoveries obtained in the range of 86.7 to 103.0%. The utilization of low density organic solvent as extraction solvent has allowed for easier operation and eliminated the use of hazardous halogenated solvent that is commonly applied in DLLME.
In this study, the antimicrobial, antioxidant, phytotoxic and phytochemical properties of defatted seeds of Jatropha curcas were evaluated. A crude methanolic extract of defatted seeds was tested against three fungal strains - Aspergillus niger, Aspergillus flavus and Aspergillus fumigatus - and five bacteria: Escherichia coli and Klebsiella pneumoniae (Gram negative) and Micrococcus luteus, Bacillus subtilis and Staphylococcus aureus (Gram positive). The methanolic extract was diluted in dimethylsulfoxide to final concentrations of 1, 2, 3, 4 and 5 mg/10 mL. The largest zones of inhibition against K. pneumoniae, M. luteus and B. subtilis were achieved using the concentration of 5 mg/10 mL. The concentration of 1 mg/10 mL was most effective against S. aureus and E. coli. In a 1, 1-diphenyl-2-picrylahydrazyl (DPPH) radical scavenging assay, the 5 mg/10 mL concentration of the Jatropha seed extract showed the strongest activity. Higher concentrations of the Jatropha seed extract (10 mg/50 mL and 5 mg/50 mL) significantly inhibited the germination of radish seeds and had negative effects on radish seedling relative water content, shoot length, root length, seedling fresh weight and seedling dry weight (p<0.05). Phytochemical analyses of the defatted seeds detected alkaloids (7.3%), flavonoids (0.39%) and soluble phenolics (mg gallic acid equivalents/g extract). Based on these results, it was inferred that J. curcas seeds contain active ingredients that are effective against pathogenic microbes and therefore could be used to formulate drugs to treat various diseases.
Generation of huge volumes of lignocellulosic biomass from agricultural sector is of concern due to its direct effects on the depletion of overall environmental quality. Conversion of biomass into solid biofuel through pyrolysis reaction has become one of the solutions to manage the abundance of biomass. Pyroligneous acid (PA) produced from the condensation of smoke generated during biomass carbonization process has the potential to be applied in various applications based on the diverse active chemical compounds present. In this study, PA obtained from palm kernel shell (PKS) was evaluated for antifungal activity and solid pineapple biomass (PB) was evaluated for antibacterial and plant growth promoter activities. Higher antifungal activity was determined for crude PA from PKS (PA-PKS) and dichloromethane-extract (DPA-PKS) with 0% coverage area when evaluated using rubber wood blocks against mold and blue sapstain after for 4 weeks of observation. This antifungal activity can be attributed to the presence of phenols and its major derivatives as suggested from the GC-MS and FTIR analysis. Concentrated PA from PB displayed good antibacterial capabilities with almost similar growth inhibition for Escherichia coli (13±1 to 20±1 mm) and Corynebacterium agropyri (20±1 mm). PA-PB also showed good potential as PGP where the addition of 2% (v/v) of PA-PB into the fertilizer for okra plant resulted in highest number of leaves and fruits while 4% (v/v) PA-PB managed to give highest plant height, longest root, heaviest fruits and biggest leaf diameter. Thus, this study successfully demonstrated the potential use of PA obtained from lignocelluosic biomass in various applications.
ix species of Eurema butterflies comprised of 261 adult individuals collected from various sampling sites in Peninsular Malaysia were identified. The morphometric measurement of the specimens was carried out by using seven characters measured from the wing and body regions. Morphometric analysis was determined through the multivariate analysis of Discriminant Function Analysis (DFA) and Cluster Analysis. The results of DFA showed that two out of seven characters utilized have the lowest values of Partial’s Wilks Lambda; basal length and hindwing length. These characters therefore are significant for the discrimination of the Eurema species. The classification matrix shows that both E. hecabe and E. blanda were completely discriminated by the characters set. Moreover, there was great overlaps occurred between the species groups when plotting a conical graph except for species E. blanda that formed homogenous group. Basal length was also suggested as the species-specific character for grouping the species E. blanda. In Cluster Analysis, E. hecabe tends to be closer to E. sari with the lowest value of agglomeration. The results from dendogram generated from average linkage also showed several relationship patterns among the six species.
This work investigates the micromechanical properties of Sn96.5Ag3.0Cu (SAC 305) on Immersion Tin (ImSn) surface
finished after subjected to high temperature storage (HTS) at 180°C for 200 to 1000 h period. Nanoindentation approach
was used to measure the micromechanical properties of the solder. It was observed that the indentation depth and plastic
depth were increased and a clear trend of decreasing hardness as opposed to the increasing reduced modulus as the HTS
time lengthened. The plasticity-asscociated properties become stronger meanwhile the elasticity-associated properties
decreased with the HTS time. These findings indicate that nanoindentation approach can clearly determine the plastic
and elastic deformation occurance throughout the test.
Anticorrosive properties of nano silicate from paddy husk in salt medium was investigated via weight loss method, Tafel
polarization and impedance techniques. Prior to the corrosion test, the silica powder was obtained from burning the
rice husk and extended with a chemical treatment process. The size of silica powder was characterized via zeta sizer and
showed the amount of micro silica particle appear more than the nano size particle. Nano silica powder was produced
from the refluxing process of micro silica to enhance the good properties of silica particle. The corrosion inhibition
efficiency of nano silicate showed good inhibition with increased in inhibitor concentrations. Weight loss test exhibits
high inhibition as more than 80% even, immersed in the corrosive medium until 14 days. The nano silicate inhibitor
affected the anodic reaction as showed by Tafel plot analysis. Impedance results also correlated with other test as shown
by the large size of Nyquist semicircle which represents as high resistance of charge transfer. The surface morphology
of inhibited specimen showed a smooth surface after nano silicate inhibitor applied in the NaCl medium as observed
through scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX).
Kaedah sol gel digunakan untuk menghasilkan filem nipis CoxZn(1-x)Al2
O4 berstruktur nano pada suhu 600°C. Corak
pembelauan XRD menunjukkan pembentukan struktur tunggal spinel ZnAl2
O4 dan CoAl2
O4
. Saiz hablur dan ketumpatan
bahan berkurangan apabila kepekatan bahan dopan Co bertambah, iaitu masing-masing daripada 19.52 kepada 10.39 nm
dan 4.609 kepada 4.585 g/cm3
. Parameter kekisi pula meningkat daripada 8.085 kepada 8.098 Å apabila Co meningkat.
Analisis FTIR menunjukkan ikatan ZnO, Co dan Al-O berlaku antara 487 hingga 550 cm-1, manakala ikatan spinel bagi
ZnAl2
O4
dan CoAl2
O4
pula terbentuk pada 655 cm-1. Imej AFM menunjukkan kekasaran permukaan menurun apabila Co
bertambah iaitu daripada 30.21 nm (×=0.00) kepada 14.83 nm (×=0.30). Nilai pemalar dielektrik (εr
) menunjukkan
penurunan secara linear apabila Co meningkat iaitu daripada 8.53 kepada 7.31. Seterusnya, GPS antena difabrikasi
menggunakan sampel CoxZn(1-x)Al2
O4
. Prestasi dan frekuensi operasi GPS antena diukur menggunakan penganalisis
rangkaian siri PNA pada frekuensi kenaan 1-2 GHz. Analisis mendapati antena beroperasi pada frekuensi 1.570 Ghz
dengan kerungian pulangan -15.6 hingga -21.2 dB dan lebar jalurnya pula adalah 80 hingga 315 MHz. Kesemua antena
yang telah difabrikasi memenuhi keperluan minimum antena untuk beroperasi pada aplikasi GPS.
The additions of nanofillers are able to enhance the mechanical properties of neat polymer matrix. There were few
researchers reported on the mechanical properties of halloysite nanotubes reinforced thermoplastic polyurethane (HNTsTPU)
nanocomposites formed through casting and compression moulding. However, fewer researchers also reported study
on HNTs-TPU formed through injection molding. The main objective of this paper was to study the effect of HNTs addition
of TPU matrix on mechanical and physical properties. HNTs were mixed in TPU matrix using a brabender mixer with
concentration ranging from 0.5 to 7 wt. % HNT loading (at specific mixing speed, mixing time and mixing temperature).
Injection moulding was carried out to form tensile bar shaped specimens with specific moulding parameters (injection
temperature, injection time and injection pressure). Increment around 35% of tensile strength of the specimen was found
at 1 wt. % HNT loading concentration which exhibited the value of 24.3 MPa, compared to neat TPU; the best mixing. The
Young’s modulus was increased with increasing HNTs loading. The elongation decreased with increasing HNTs loading.
The FESEM results showed that HNTs were dispersed in TPU matrix. The TGA results showed that the addition of 1 wt. %
HNTs enhanced the thermal properties. It can be concluded that HNTs-TPU has improved tensile and physical properties
compared with neat TPU due to the addition of nanofiller.
Flourine doped tin oxide films were synthesized by using hydrothermal method with different volume of solvents. The
thin film growth was carried out by fixing the concentration of tin and fluorine element precursors by only varying their
solvents which were 2-propanol and DI water. The fabrication of FTO thin film by using mineral salt group as tin precursor
with hydrothermal method on soda lime glass showed that the nanostructured growth did not distribute largely and took
longer time. The seed layer of FTO has been used to overcome these problems thus the thin film growth distributed largely
in short time. These experiments were conducted at a constant of hydrothermal temperature and reaction time which
were 150°
C and 5 h respectively. The result showed that, there was a change on the surface morphology in the formation
of FTO films. The minimum value of sheet resistance was 0.1475 Ω/sq which was obtained using 65 mL of 2-propanol
and 20 mL of DI water was lower than sheet resistance of commercial FTO films of 01693 Ω/sq. This fabricated FTO films
showed a good transparency with higher of transmittance than 80%. The experimental findings suggested that 65 mL
amount of 2-propanol and 20 mL of DI water in precursor solutions could produce the better of FTO performance than
commercial FTO.
Zinc selenide/graphene oxide (ZnSe/GO) composite is synthesized using hydrothermal method. Two different methods
such as direct and indirect route have been investigated to form the ZnSe/GO composite. In this research, the graphene
oxide used was in sheet and liquid form. The synthesized composite was then characterized using X-ray diffraction (XRD)
for phase identification, field emission scanning electron microscopy (FESEM) for morphology analysis and ultravioletvisible
spectroscopy (UV-Vis) for optical properties. ZnSe/GO composite showed absorption peak ranging from 460 to
480 nm with the optical band gap obtained through Tauc equation. The optical band gap of the ZnSe/GO composite has
been tuned down to a smaller value as compared to the bulk ZnSe compound. The optical band gap has been reduced
to around 2.53 eV when liquid graphene oxide was used while around 2.23 to 2.32 eV when graphene oxide sheet was
used. The purity of ZnSe/GO composite synthesis via indirect hydrothermal method is higher than those synthesized via
direct hydrothermal method. The type of graphene oxide will affect the morphology of the composite where the ZnSe
compound was either wrapped by tiny thorn-like substance or graphene oxide layer.
Titanium dioxide (TiO2
) nanoparticles thin film has been successfully synthesized by a spray pyrolysis deposition method
by using an air compressor on a fluorine-doped tin oxide (FTO) substrate and was annealed at different temperature. TiO2
is the most common oxide as an electrode in dye sensitized solar cell (DSSC) which still has chances of improvements to
increase its efficiency as an electrode. The efficiency of a DSSC was relatively low but modifications on every part of a
DSSC were currently in research progress and an increase in adsorbed dye molecules was considered a potential. Thus,
the influences of annealing temperature on structural and morphological properties of TiO2
have been studied using
X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM), respectively, while the efficiency of
the films in a solar cell was studied by a solar simulator. The FESEM result showed several degrees of porosity obtained
by varying the annealing temperature. The crystallinity of TiO2 investigated by XRD showed that the crystallinity of the
TiO2
thin films was generally unaffected by the annealing temperature. The relationship between the properties and the
efficiency of the films as an electrode was also studied
Zinc selenide (ZnSe) quantum dots (QDs) have been synthesized through a hydrothermal method using ZnCl2
and Na2
SeO3
powder as the precursor in the presence of oleylamine as capping agent. The hydrothermal route was conducted at a
moderate temperature (150°C) for 8 h. Optical properties of ZnSe QDs were studied through ultraviolet-visible spectroscopy
(UV-Vis) and photoluminescence (PL) while the structural properties of ZnSe QDs were characterized using transmission
electron microscope (TEM). The photoluminescence (PL) characterization on ZnSe QDs showed that the QDs emit light in
blue range region at around 440 nm with optical band gap energy at 3.68 eV. The TEM results showed that the average
particle size is around 8.9 nm. It is a good candidates for optoelectronic devices such as light emitting diodes (LED).
Due to the increasing production and use of nanoparticles in various sectors such as electronic industries and healthcare,
concerns about the unknown effects caused by the presence of these materials in the natural environment and agricultural
systems were on the rise. Because of the growing trend of ZnO nanoparticles (nZnO) which is one of the most widely
used nanoparticles being released into the environment, it has attracted the attention for more studies to be done on
the effects of this nanoparticle on organisms. This study was carried out to investigate the phytotoxicity effect of nZnO
on groundnut seedlings in Murashige and Skoog (MS) medium. The experimental treatments of this study include eight
concentrations of nZnO (10, 30, 50, 100, 200, 400, 1000 & 2000 mg.L-1) added to MS medium and MS medium without
nanoparticles have been used as control treatment. For the first 6 days after sowing, germination percent and germination
rate index were calculated by counting the germinated seeds every day. Groundnut seedlings were incubated for 3 weeks
in optimum condition and after that, seedling characteristics such as length, wet and dry weight of radicle and plumule
were measured. The water content of radicle and plumule were also calculated. The results of this study showed that
radicle and plumule length of groundnut seedlings were affected by nZnO exposure, in a way that length of radicles in 50
mg.L-1 nZnO and higher concentrations was significantly lower than that of control treatment and the shortest plumule
length was observed in 2000 mg.L-1 nZnO concentration treatment. Both the radicle and plumule wet weight were also
decreased as the nanoparticle concentration was increased. However, despite the decreasing in radicle and plumule dry
weight with increasing in nZnO concentration, this increase was not significant. However radicle dry weight in 10 mg.L-1
nZnO was significantly higher than nZnOtreatments with 200 mg.L-1 concentration and higher concentrations. Moreover,
observations of this study did not show any significant difference between the water content of nZnO concentration
treatments and control treatment.