Each year, influenza A infections have caused tremendous death rate as high as 300,000-500,000 globally. Although
there are effective anti-influenza agents and vaccines, high mutational rate among influenza A viruses renders dramatic
decline in the effectiveness of anti-influenza agents or vaccines in certain individuals. The situation is further complicated
by limitations in influenza vaccine production, for instance, long production period, limited vaccine capacity and lack
of cross-protection against various influenza A virus strains. To solve these issues, development of universal influenza
vaccine based on conserved antigens such as non-stuctural protein 1 (NS1) has been endeavoured. NS1 protein is highly
conserved in all influenza A virus strains known by far, produced abundantly on infected cell surfaces and responsible for
maintaining virulence. Furthermore, cytotoxic T-lymphocytes that are active against NS1 were also reported to be able
to avoid shedding of influenza in hosts. To better inhibit influenza infections, oral immunization has long been proposed
due to feasibility of this method to be implemented and safer for recipients while able to target influenza A viruses from
the entry point. Lactobacillus has been vastly studied for its roles as bacterial carrier in oral vaccine development due
to its significant probiotic properties. For examples, stimulation of immune responses in oral and airway mucosal layers,
high colonization in oral and airway mucosal layers and great natural adjuvant effects. In this light, influenza universal
oral vaccine developed using NS1 dan Lactobacillus should be further studied in influenza oral vaccine design.
Mutagenic and antimutagenic activities of lactic acid bacteria (LAB) Lactobacillus plantarum isolated from the local fermented durian (tempoyak) was determined by Ames test (Salmonella/microsome mutagenicity assay). Our study also involved pre-incubation assay against Salmonella typhimurium TA 98 and TA 100 bacterial strain in the presence and absence of metabolic activator S9 system. It was found that the L. plantarum showed no mutagenic activity on both S. typhimurium strain TA 98 and TA 100 in the presence and absence of metabolic activator. Significant antimutagenic activity (p < 0.05) was observed in both cell-free supernatant and bacterial cell suspension of L. plantarum as compared to the mutagenicity induced by 2-Aminoanthracene in the presence of metabolic activator. Meanwhile, in the absence of metabolic activator, only the bacterial cells of L. plantarum showed antimutagenicity acitivity against Sodium Azide and 2-Nitrofluorene. In conclusion, L. plantarum could play a vital role as chemopreventive agent by binding to mutagens and suppressing mutagenesis. Thus, L. plantarum could be consider as a good candidate for functional food development as a supplement product to prevent development of colon cancer.
Multicomposition of Er3+ -Y11-3+ codoped tellurite oxide, Te02-ZnO-PbO-Ti02-Na20 glass has been investigated. A detailed spectroscopic study of the Judd-Ofelt analysis has been performed from the measured absorption spectrum in order to obtain the intensity parameters S2, (t=2, 4, 6). The calculated S2, values were then utilized in the determination of transition probabilities, radiative lifetimes and branching ratios of the Er3+ transitions between the J(upper)-J'(lower) manifolds. Both visible upconversion and near-infrared spectra were characterized under the 980 nm laser diode excitation at room temperature.
In this study, a symmetric supercapacitor has been fabricated by adopting the nanostructured iron oxide (Fe304)-activated carbon (Ac) composite as the core electrode materials. The composite electrodes were prepared via a facile mechanical mixing process and PTFE polymeric solution has been used as the electrode material binder. Structural analysis of the nanocomposite electrodes were characterized by scanning electron microscopy ( sEm) and Brunauer-Emmett-Teller (BET) analysis. The electrochemical performances of the prepared supercapacitor were studied using cyclic voltammetry (cv) and electrochemical impedance spectroscopy (Eis) in 1.0 M Na2S03 and 1.0 M Na2SO4 aqueous solutions, respectively. The experimental results showed that the highest specific capacitance of 43 FIg is achieved with a fairly low Fe304 nanomaterials loading (4 wt. %) in 1 M Na2S03. It is clear that the low concentration of nanostructured Fe304 has improved the capacitive performance of the composite via pseudocapacitance charge storage mechanism as well as the enhancement on the specific surface areas of the electrode. However, further increasing of the Fe304 content in the electrode is found to distort the capacitive performance and deteriorate the specific surface area of the electrode, mainly due to the aggregation of the Fe304 particles within the composite. Additionally, the cv results showed that the Fe3041Ac nanocomposite electrode in Na2S03 electrolyte exhibits a better charge storage performance if compared with Na2SO4 solution. It is believed that Fe304 nanoparticles can provide favourable surface adsorption sites for sulphite (S032-) anions which act as catalysts for subsequent redox and intercalation reactions.
Deterioration of water quality mainly due to high total ammonia nitrogen (TAN) and nitrite will affect the productivity of shrimp culture. In this study, three indigenous strains assigned as VCM5, VCM8 and VCM12 were evaluated for their ability to degrade TAN and nitrite. These strains were inoculated into shrimp aquaculture wastewater to enhance the degradation of TAN and nitrite. All the strains reduced TAN and nitrite level from the shrimp aquaculture wastewater significantly (p<0.05). Strain VCM5 (GenBank accession number KJ700465) and VCM8 (GenBank accession number KJ700464) showed 99.71% sequence similarity with the 16S rRNA gene type species Bacillus vietnamensis 15-1T (ABO99708) and strain VCM12 (GenBank accession number KJ700463) showed 99.05% sequence similarity with 16S rRNA gene sequence type species Gordonia bronchialis DSM43247T (CP001802).
Hidroksiapatit (HA) adalah sejenis kalsium fosfat yang merupakan komposisi kepada kebanyakan fasa mineral tulang dan enamel gigi. HA bersifat bioserasi dan berkonduksi osteo selain mempunyai afiniti biologi dan kimia yang bagus untuk tisu tulang. Dengan ciri tersebut, HA diguna secara luas sebagai graf tulang dan bahan salut bagi implan tisu keras manusia. Walau bagaimanapun, kerapuhan dan keliatan patah yang rendah HA tersinter menghadkan penggunaannya dalam aplikasi bebanan yang tinggi. Kajian ini tertumpu kepada mengenal pasti kesan atmosfera sinteran dengan gas nitrogen (N2) ke atas sifat mekanik HA untuk aplikasi pergigian. Serbuk nano HA dicirikan dengan menggunakan mikroskop elektron pancaran. Cakera silinder HA dihasilkan dengan kaedah penekanan ekapaksi. Kemudian, cakera silinder HA dikenakan tekanan isostatik sejuk dan disinter dalam dua atmosfera sinteran yang berbeza iaitu sinteran dalam gas N2 dan sinteran dalam udara pada suhu 1300°C. Ketumpatan, mikrostruktur, kestabilan fasa dan mikrokekerasan HA tersinter dicirikan. Secara keseluruhan, sinteran dengan menggunakan gas N2 menyebabkan pertumbuhan saiz butiran yang lebih besar dengan ketumpatan relatif dan mikrokekerasan yang lebih tinggi jika dibandingkan dengan atmosfera sinteran dalam udara. Dalam kajian ini, HA yang disinter dengan menggunakan gas N2 pada suhu 1300°C menunjukkan mikrostruktur yang lebih tumpat, ketumpatan relatif (94%) dan mikrokekerasan (4.07 GPa) yang lebih tinggi jika berbanding dengan sinteran dalam udara tanpa penguraian HA. Kesimpulannya, penggunaan atmosfera sinteran dengan menggunakan gas N2 pada suhu 1300°C dapat meningkatkan sifat kekerasan Vickers nanokomposit HA dengan mikrostruktur yang padat.
Pembangunan model biosensor DNA berasaskan pengikatan dan interaksi kompleks logam sebagai penanda penghibridan
DNA boleh digunakan untuk diagnosis awal virus denggi melalui penghibridan DNA denggi sebagai DNA sasaran.
Kompleks nikel(II) salfen dengan rantai sisi piperidina berjaya disintesis dan pencirian dijalankan dengan menggunakan
Spektroskopi Magnetik Nukleus (NMR), Spektroskopi inframerah (FTIR), spektrometri jisim dan kolorimetri pengimbasan
pembezaan. Jenis perikatan dan interaksi antara kompleks nikel(II) salfen dengan rantai sisi piperidina dan DNA denggi
dikaji dengan pentitratan DNA ultralembayung nampak. Berdasarkan spektrum ultralembayung nampak, hipokromisme dan
anjakan merah (batokromisme) diperhatikan apabila kompleks nikel(II) salfen dengan rantai sisi piperidina dititratkan
dengan DNA denggi menunjukkan pembentukan kompleks baru. Kompleks nikel(II) salfen dengan rantai sisi piperidina
berinteraksi dengan DNA denggi secara perikatan interkalasi dengan pemalar perikatan, Kb= 4.576×105
M-1. Penemuan
ini sangat berharga dalam menjadikan kompleks nikel(II) salfen sebagai penanda penghibridan bagi biosensor DNA
optik untuk mengesan kehadiran virus denggi.
Agrobacterium-mediated transformation of indica rice is undoubtedly a challenging task due to the rice recalcitrant nature to transformation process. Therefore, optimization of the transformation protocol is important for specific indica rice cultivar to ensure effectiveness of the transformation. In this study, crucial parameters affecting Agrobacteriummediated transformation were optimized to obtain transgenic rice of local rice cultivar (indica MR219). Embryogenic calli were chosen for inoculation with Agrobacterium tumefaciens strain LBA4404 harbouring a binary vector pH2GW7ABP57 containing gene of interest, Auxin binding protein 57 (Abp57). The parameters that have been optimized were the immersion time, co-cultivation period, acetosyringone concentration and co-cultivation temperature. A total of four days co-cultivation period and 30 min immersion of embryogenic callus are optimum for the transformation of MR219 with transformation efficiency of 26.4% and 16.0%, respectively. Acetosyringone at 200 μM and co-cultivation at 28°C also gave the highest transformation efficiency (14.4 and 18.4%, respectively). Meanwhile, inclusion of 20 g/L maltose+20 g/L sorbitol into the regeneration media has significantly improve the transformed somatic embryos growth and increase the regeneration efficiency up to 40.0%. The results of polymerase chain reaction (PCR) and reverse transcription-polymerase chain reaction (RT-PCR) indicated that the transgene was successfully integrated and overexpressed in transgenic rice of MR219. In conclusion, significant improvement in transformation efficiency for rice cv. MR219 has been obtained by using the optimised protocol for transformation and regeneration developed in this study.
The ratios of Tween 80 to Span 80 are important in controlling the physicochemical characteristics of curcumin niosomes. Thus, in this study the correlations of combination of Tween 80 and Span 80 at different ratios with the size and stability of curcumin niosomes were investigated. Initially curcumin was dissolved in chloroform and methanol (v/v= 3:1), followed by the preparation of niosomes by thin-film hydration method with the mole ratio of mixture of Tween 80 and Span 80 to cholesterol of 2:1. The ratios of Tween 80 to Span 80 in the mixture were set at 1:1, 1:9, 9:1, 2:3 and 3:2 with Hydrophilic-Lipophilic Balance (HLB) values of 9.65, 5.37, 13.93, 8.58 and 10.72, respectively. As expected, niosome barely formed at HLB value 13.93. This might be due to the molecule being hydrophilic and well hydrated which inhibits the formation of a stable bilayer in solution. It was found that the formulation which has higher Span 80 and lower HLB value leads to larger niosome before sonication. The largest niosome size achieved from Tween 80 to Span 80 ratio of 1:9 and 2:3 was 77.36 and 59.85 μm, respectively. On the other hand, for the ratio of 3:2, the largest niosome formed before sonication was less than 50.00 μm. After sonication, the niosome size reduced to less than 35.00 μm for all formulations. It was showed that formulation with Tween 80 to Span 80 ratio of 1:9 has superior curcumin entrapment efficiency and best stability during storage. The results demonstrated that appropriate ratio of Tween 80 to Span 80 was necessary for forming small and stable curcumin niosomes.
A local Malnutrition Risk Screening Tool-Hospital (MRST-H) has been developed to identify the risk of malnutrition among hospitalized geriatric patients in Malaysia. The aims of this multicenter study were to evaluate the criterion validity of the MRST-H against the reference standard Subjective Global Assessment (SGA) and revise its scoring criteria among Malaysian geriatric patients. A cross-sectional study was conducted among 542 geriatric patients at eight general hospitals in Peninsular Malaysia from January 2011 to February 2013. The Malay version MRST-H and SGA were administered to all participants through face-to-face interviews. Sensitivity and specificity of MRST-H were established using the Receiver Operating Characteristic (ROC) curves and the optimal cut-off scores were determined. The MRST-H had area under the ROC curve (AUC) values of 0.84 and 0.88 when validated against the SGA-determined malnutrition (SGA B+C) and severe malnutrition (SGA C) status. These high AUC values indicated that the MRST-H has very good overall diagnostic accuracy. However, the original cut-off score of five points for MRST-H has undesirable sensitivity in identifying the malnutrition (sensitivity = 0.12) and severely malnutrition (sensitivity = 0.35) status. The optimal cut-off score of MRST-H in identifying malnourished and severely malnourished participants were both established at the cut-off score of two points. The sensitivity of MRST-H increased substantially at this point without compromising its specificity. Therefore, the established cut-off score of two points with optimal sensitivity and specificity was selected to replace to original cut-off score for screening of risk of malnutrition among hospitalized geriatric patients.
Aromatic grass species Cymbopogon citratus (‘serai biasa/serai makan’) and C. nardus (‘serai wangi’) can be commonly found throughout Peninsular Malaysia. C. citratus is used in traditional Malaysian cooking and brewed as tea, while C. nardus is used in traditional medicine for external application and in insect repellents. Due to similar morphologies, it can be difficult to tell apart the species at times. Based on DNA sequence alignments of three chloroplast DNA intergenic spacer regions, namely atpB-rbcL, trnH-psbA and trnL-trnF, we designed species-specific primers for multiplex PCR assays for rapid species discrimination between C. citratus and C. nardus. The method described here makes use of simple molecular techniques that are time- and cost-effective for large-scale application. Such an assay will be useful for the quality assurance of food and medicinal products.
Catanionic system using anionic sodium bis-(2ethylhexyl)sulfosuccinate (Am) and cationic cetyltrimethylammonium bromide (cTAB) is studied. The system is prepared by addition of CTAB solution to a prepared AOT solution until slight anionic-rich catanionic phase is produced. Catanionic system consists of the mixture of different types of surfactants and counterion due to electrostatic interaction between the oppositely charged surfactant. Both of these products affect the in surface activity of the surfactant. Hydrodynamic diameters decrease and clearer solution were seen with the increase of CTAB concentration in solution mixture. As a result, mixed surfactant with larger hydrophobic region and the presence of counterion will induce smaller vesicle to form in catanionic system.
The Hibiscus sabdariffa var. UMKL (Roselle) investigated here may potentially be used as an alternative fibre source. To
the best of our knowledge, there was no study focusing on the genetics underlying the cellulose biosynthesis machinery
in Roselle thus far. This paper presents the results of the first isolation of the cellulose synthase gene, HsCesA1 from this
plant, which is fundamental for working towards understanding the functions of CesA genes in the cellulose biosynthesis
of Roselle. A full-length HsCesA1 cDNA of 3528 bp in length (accession no: KJ608192) encoding a polypeptide of 974
amino acid was isolated. The full-length HsCesA1 gene of 5489 bp length (accession no: KJ661223) with 11-introns
and a promoter region of 737 bp was further isolated. Important and conserved characteristics of a CesA protein were
identified in the HsCesA1 deduced amino acid sequence, which strengthened the prediction that the isolated gene being
a cellulose synthase belonging to the processive class of the 2-glycosyltransferase family 2A. Relative gene expression
analysis by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) on young leaf and stem tissues
found that HsCesA1 had similar levels of gene expression in both tissues. Phylogenetic and Blast analyses also supported
the prediction that the isolated HsCesA1 may play roles in the cell wall depositions in both leaf and stem tissues.
In general, demand feeding devices are equipped with a mechanical trigger switch. Such a switch is not suitable for
juvenile fish with a small body size, because the body weight is insufficient to trigger the feeder. An infrared light
sensor that does not require the fish to push a feeder switch is more suitable for small fish. The brown-marbled grouper
Epinephelus fuscoguttatus is an important fish species in Southeast Asia. The purpose of this study was to compare the
growth rates (GRs) of brown-marbled grouper juveniles reared using customised demand feeding devices with an infrared
light sensor (the infrared light demand feeder (IRDF) group) and automatic feeding devices (the automatic feeder (AF)
group). The results indicated that GRs of standard lengths and body weights showed no significant differences using
one-way analysis of variance; however, the standard length of the IRDF group showed a tendency of a higher GR than
the AF group. Although the feed conversion ratio (FCR) also showed no significant difference, the FCR of the IRDF group
was more efficient, indicating that the IRDF group yielded a more desirable FCR. These results indicate that IRDF can be
used in the culture of brown-marbled grouper juveniles. In view of the working schedule of the fish farm staff, IRDF are
superior to other feeding devices, because they are less labour-intensive than usual tasks. We conclude that IRDF is a
useful feeding system for aquaculture.
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by deterioration of the brain functions
that result in impairment of memory, cognition and behavioural functions. Oxidative stress is well known to be one of the
causative factors for AD. Thus this disease is potentially modulated by natural antioxidants such as vitamin E. The aim
of this study was to evaluate the effect of tocotrienol-rich fraction (TRF) supplementation on antioxidant enzymes and
DNA damage using APPswe/PS1dE9 transgenic mouse model of AD. Animals were supplemented with TRF (200 mg/kg)
or alpha-tocopherol (αT) (200 mg/kg) for six months starting from nine months old. We found that superoxide dismutase
(SOD) activity in AD mouse was decreased by supplementation of TRF and αT as compared with AD control mouse with no
significant differences in glutathione peroxidise (GPx) activity in all groups. TRF supplementation significantly increased
catalase (CAT) activity. The level of DNA damage of AD mouse shows significant decrease with supplementation of TRF
and αT. In conclusion, TRF was able to modulate antioxidant enzymes activity and decreased the level of DNA damage
of AD transgenic mouse model.
Metallic foams are a new class of materials that have a great potential to be used in various functional and structural applications. Due to their competitive price compared to aluminium, metallic foams are anticipated to become an alternative material for light-weight structures. In this study, stainless steel foams are fabricated using a powder space holder method. The materials used include stainless steel powder, a novel space holder glycine and binders consisting of palm stearin and of polyethylene (PE). The stainless steel foams are sintered at 1100o C, 1200o C and 1300o C with sintering times of 1, 2 and 3 h, respectively, to investigate the effects of the sintering parameters on the compressive yield strength of the stainless steel foams. The results showed that all of the stainless steel foams produced exhibit the general behaviours of metal foams. The sintering time is the most significant parameter that influences the compressive yield strength of stainless steel foams. Increasing the sintering temperature and sintering time will increase the compressive yield strength. The interaction between the sintering temperature and sintering time is found to be not statistically significant.
Amphibians have undergone catastrophic declines worldwide and the major histocompatibility complex (MHC) is an
attractive candidate for investigating the link between adaptive variation and individual fitness. Nonetheless, little research
has been conducted to study the amphibians MHC genes. Thus, MHC class Ia of Odorrana margaretae, a representative
species of the Odorrana, was isolated and used to analyze the adaptive mechanism. We isolated alleles and determined
evolution patterns of MHC class Ia in O. margaretae. The phylogenetic tree of MHC class Ia was reconstructed to
understand the evolutionary relationship of Anura. In O. margaretae of MHC class Ia: there were more non-synonymous
mutations compared to synonymous mutations; there are at least two loci; the recombination alleles took place for a
large proportion (55.56%) of the alleles and recombination usually took place between whole exon of Ia genes of MHC
class; positive selection sites were detected and most (10 of 19) located at the α1 and α2 domains belonged to the
presumed ABS. The diversity of genes of MHC class Ia was led by recombination, gene duplication and positive selection.
Trans-species polymorphisms of anuran genes of MHC class Ia were evident in anurans. Therefore, the MHC class Ia
present demonstrative candidates for investigating the link between adaptive variation and individual fitness. We argue
that knowledge of the MHC of other anuran lineage, especially focusing a genus such as O. margaretae, should provide
an overall more complete picture of the organization of MHC in anurans.
Biosensor optik berasaskan hemoglobin (Hb) terpegun pada mikrosfera poli(n-butil akrilat-co-N-akriloksisuksinimida)
[poli(nBA-NAS)] telah dibangunkan bagi mengesan kepekatan ion nitrit (NO2
-
). Kompleks HEM ferum dalam Hb
memangkinkan tindak balas penurunan ion NO2
-
kepada nitrik oksida (NO) lalu bergabung dengan deoksihemoglobin
(HbFe2+) membentuk kompleks ferum-nitrosil-hemoglobin (HbFe2+-NO) yang berwarna hijau kekuningan. Spektrofotometer
pantulan gentian optik digunakan untuk memantau kepekatan ion NO2
-
secara kuantitatif berdasarkan perubahan warna
Hb terpegun pada mikrosfera poliakrilat daripada perang kemerahan ke hijau kekuningan pada panjang gelombang
pantulan maksimum 668 nm. Pencirian terhadap biosensor nitrit reflektometrik melibatkan ujian kesan pH, kesan
kepekatan Hb, julat rangsangan linear, kebolehasilan, jangka hayat dan kesan gangguan ion telah dijalankan. Biosensor
ion NO2
- optik terbangun memaparkan julat linear dinamik daripada 5 hingga 50 mg mL-1 (R2
=0.9894) pada pH7.0 dengan
had pengesanan (LOD) sebanyak 3.3 mg mL-1 dan nilai sisihan piawai relatif (RSD) kebolehasilan biosensor sebanyak
5.8%. Jangka hayat biosensor optik nitrit tersebut adalah selama 36 hari dan majoriti ion asing yang sering wujud
bersama ion NO2
- dalam sampel air semula jadi tidak menunjukkan kesan gangguan yang bererti terhadap penentuan
ion NO2
-
menggunakan biosensor optik terbangun kecuali ion Hg2+, Ag+, Br-
dan S2-.
PR-10 is a member of pathogenesis-related (PR) genes elicited by the plant’s defense mechanism during pathogen attack.
Elevated expression of PR-10 upon different pathogen invasions has been observed in many plant species suggesting
its role as an anti-bacterial, anti-viral and anti-fungal gene. However, the effect of PR-10 in mitigating the infection of
Fusarium oxysporum f. sp. cubense (Foc), the causal agent of Fusarium wilt in banana has not been reported. In this
study, the coding sequences of PR-10 gene isolated from Foc resistant Musa acuminata ssp. malaccensis (MaPR-10)
were integrated into a local Foc susceptible commercial banana cultivar, Berangan via co-cultivation of embryogenic
cell suspension and Agrobacterium tumefaciens. Out of 17 putative transgenic lines established, 11 of them positively
harbored MaPR-10. Among these, Line-19 plantlets showed the most rapid in-vitro propagation and successfully overexpressed the transgene. Following a nursery challenge experiment with a virulent Foc race 4 (CI HIR) isolate, about 30%
of Line-19 plants showed a one-week delay in disease progression when compared to the untransformed controls. From
the final evaluation performed in the 5th week-post-inoculation, the leaf symptoms index (LSI) and rhizome discoloration
index (RDI) of Line-19 was 3.4 and 6.1, respectively, indicating the disease had progressed. The findings of this study
enrich the current existing knowledge on the roles of PR-10 in combating fungal disease in plants.
The Nipah virus is highly virulent to swine and humans. The envelope attachment glycoprotein (G) of Nipah virus
plays a key role in viral entry and induction of neutralizing antibody in mammalian hosts, thus is considered a good
candidate for vaccine development. Plant transient expression systems are gaining recognition as a viable alternative
for the production of vaccine antigens. In this study, we expressed the Nipah virus G protein heterologously in Nicotiana
benthamiana using an agroinfiltration approach. The highest expression of recombinant G protein in N. benthamiana at
RNA and protein levels was detected on day 9 post-infiltration. Western blot analysis demonstrated that the purified G
protein reacted specifically with rabbit anti-Nipah Virus serum, indicating its potential for vaccine use.