Intervensi pemakanan berpotensi untuk melambatkan penurunan fungsi kognitif dalam kalangan warga tua yang mengalami kecelaan kognitif ringan (MCI). Walau bagaimanapun, kemampanan program sedemikian masih belum dapat dipastikan. Oleh itu, suatu kajian susulan dijalankan bagi menentukan kemampanan suplementasi minyak ikan dan pendidikan kesihatan bagi mengurangkan kemerosotan fungsi kognitif dalam kalangan warga tua yang mengalami MCI selepas setahun kajian intervensi dijalankan. Kajian ini melibatkan 18 orang subjek MCI iaitu 6 orang bagi setiap kumpulan intervensi suplementasi minyak ikan (A) dan pendidikan kesihatan (B) dan kumpulan kawalan (C). Analisis menunjukkan kesan intervensi yang signifikan bagi ujian Span Digit (p<0.05) dan aras serum folat (p<0.05) dengan kumpulan B menunjukkan min yang paling tinggi, diikuti dengan A dan C. Intervensi pendidikan kesihatan dan suplementasi minyak ikan mempunyai kesan kemampanan bagi meningkatkan aras serum folat dan memperbaiki status fungsi kognitif yang dinilai menggunakan Ujian Span Digit. Terdapat keperluan bagi promosi kesihatan dan suplementasi minyak ikan dalam mengekalkan fungsi kognitif individu warga tua yang mengalami MCI
Sensor Al(III) optik berasaskan prinsip pengukuran pantulan dengan menggunakan manik polimer terkandung polimer (PIMs) terpegun telah dibangunkan. Manik PIMs terpegun yang disediakan dalam kajian ini mengandungi manik poli(vinil klorida) (PVC), Aliquat 336, diositil pthalat (DOP) dan reagen eriokrom sianin R (ESR). Sensor yang menggunakan manik PIMs terpegun ini menunjukkan rangsangan yang lebih tinggi berbanding dengan sensor yang tidak menggunakan manik PIMs. Masa rangsangan sensor pula ditetapkan selepas 3 min dengan nilai pH optimum 6.0. Sensor Al(III) optik ini memberikan rangsangan linear pada julat 5.56×10-5 - 3.52×10-4 molL-1, dengan nilai had pengesanan terendah (LOD) yang dikira ialah 3.41×10-5 molL-1. Kajian validasi nilai ion Al(III) bagi beberapa sampel air semula jadi yang ditambah dengan ion Al(III) menggunakan sensor Al(III) optik yang dibangunkan dalam kajian ini, menunjukkan tiada perbezaan secara signifikan pada nilai ion Al(III) yang diperoleh apabila dibandingkan dengan keputusan yang diperoleh menggunakan spektrofotometer serapan atom konvensional.
Kualiti membran AAO yang disediakan melalui teknik penganodan dua peringkat adalah sangat dipengaruhi oleh pra-pembentukan cekung yang dihasilkan semasa penganodan pertama. Kajian ini dijalankan untuk menentukan tempoh penganodan yang optimum bagi menghasilkan cekung yang berkualiti. Penganodan dilakukan menggunakan larutan 0.3 M H2C2O4 sebagai elektrolit dengan beza keupayaan dan suhu masing-masing ditetapkan pada 40 V dan 18°C. Proses penganodan dilakukan sehingga 6 jam. Perubahan nilai arus sepanjang tempoh penganodan direkodkan. Selepas penyingkiran lapisan oksida, kualiti cekung yang terbentuk dikaji menggunakan FESEM. Mikrograf FESEM mengesahkan pembentukan cekung berstruktur heksagon adalah seragam. Selain memperbaiki keseragaman, pertambahan tempoh penganodan telah membentuk cekung yang lebih jelas, tersusun serta kecacatan yang minimum. Keputusan kajian mendapati bahawa tempoh optimum bagi mendapatkan cekung yang seragam dan sempurna adalah antara 4 dan 6 jam. Ini kerana pertambahan tempoh penganodan seterusnya akan menyebabkan keruntuhan dinding cekung yang akhirnya menjadi punca kepada pembentukan liang yang bersentuhan antara satu sama lain. Selain itu, mekanisma penghasilan bentuk cekung turut dibincangkan.
Mekanisme pembentukan apatit pada permukaan β-wolastonit dikaji. β-wolastonit dihasilkan daripada teknik sol-gel menggunakan abu sekam dan batu kapur terkalsin sebagai bahan pemula dengan nisbah CaO:SiO2 adalah 55:45. Kebioaktifan sampel β-wolastonit dikaji dengan merendam sampel berbentuk silinder dalam larutan simulasi badan (SBF) untuk tempoh yang ditetapkan iaitu 1, 3, 7 dan 14 hari. Komposisi permukaan, morfologi dan perubahan struktur sampel sebelum dan selepas direndam dianalisis melalui pembelauan sinar-X (XRD) dan mikroskop elektron imbasan (FESEM) yang digabungkan dengan EDX. Keputusan XRD menunjukkan fasa β-wolastonit berjaya dihasilkan selepas dimasukkan ke dalam autoklaf untuk 8 jam pada suhu 135°C pada tekanan 0.24 MPa dan disinter 2 jam pada suhu 950°C. Apatit didapati tumbuh pada permukaan sampel β-wolastonit selepas 7 hari rendaman dalam larutan SBF. Semasa proses rendaman dalam larutan SBF, 2 jenis kumpulan kalsium fosfat dihasilkan iaitu amorfus kalsium fosfat (ACP) selepas 3 hari rendaman dengan julat nisbah Ca/P 1.2-2.02 dan pada hari ke-14 membentuk hidroskiapatit kurang kalsium (CDHA) dengan nisbah Ca/P 1.63. Perubahan fasa sampel β-wolastonit daripada keadaan hablur kepada amorfus jelas terbukti daripada keputusan XRD selepas direndam dalam SBF dengan penurunan puncak keamatan bagi sampel β-wolastonit pada sudut belauan 30°. Ini mengukuhkan mekanisme pembentukan lapisan apatit pada permukaan sampel β-wolastonit dan ianya bersifat bioaktif.
Peat soil is characterized by its high content of decomposed organic matter. Majority of areas occupied by peatland have
been developed for agriculture sectors such as pineapple cultivation and oil palm. Due to its geotechnical drawback
characteristics such as highly compressibility and low shear strength, peat soil is classified as problematic soils and
unstable for engineering structures. Lack of suitable and expensive price of lands, peatland will be an alternative
option for future development. Prior to construction works, stabilization of peat soil should be performed to enhance
its engineering characteristics. This paper presents the effect of cement and curing period on engineering properties
of the cement-treated peat soil. Some engineering variables were examined including the compaction behaviour,
permeability and unconfined compressive strength (UCS). The Atterberg limit test was also carried out to examine
the influence of cement addition on peat soil. The cement-treated peat soils were prepared by adding varying amount
of ordinary Portland cement (OPC) ranging between 0% and 40% of dry weight of peat soil. In order to examine the
effect of curing, the treated samples were dried at room temperature for three and seven days while for UCS tests
samples were extended to 28 days prior to testings. The results showed that the liquid limit of treated soil decreased
with the increase of cement content. Maximum dry density (MDD) increased while optimum moisture content (OMC)
dropped with the increase in cement content. Permeability of treated soil decreased from 6.2×10-4 to 2.4×10-4 ms-1 as
cement content increase from 0% to 40%. In contrast, the UCS tests indicated an increase in uncompressive strength
with the increase in cement contents and curing period. The liquid limit and permeability were also altered as curing
periods were extended from three to seven days. This study concluded that geotechnical properties of peat soil can
be stabilized using ordinary cement and by modification of the curing periods.
Pleurotus sajor-caju (PSC) is an oyster mushroom widely consumed in Asian countries and successfully cultivated in
Malaysia. This study aimed to determine nutritional compositions, functional properties and storage stability of PSC
powder based on storage temperature. Fresh PSC was dried using low heat air blow technique and ground into fine
powder. Nutritional analyses of PSC powder were conducted following AOAC methods. Functional properties were also
determined accordingly. For storage stability study, four portions of PSC powder were stored at temperature of -20, 4,
25 and 35o
C separately, and then studied parameters were investigated at time 0, 3 and 6 months. PSC powder contains
appreciable amounts of protein (22.41%), ash (7.79%), dietary fibre (56.99%) and β-glucan (3.32%) but low content
in sucrose (0.19%) and fat (2.30%). It also possesses notable functional properties such as water holding capacity, oil
holding capacity, swelling capacity and emulsifying activity. Storage stability study showed that PSC powder exhibited lower
moisture content and L* colorimetric value. Meanwhile higher water activity level with increasing storage temperature
but no significant difference in pH value and microbial counts were detected. Besides, storage temperature at -20, 25
and 35o
C jeopardized the original colour properties of PSC powder. The best storage temperature for PSC powder is 4o
C.
PSC powder has the potential to be a safe and as an alternative dietary fibre rich ingredient in food industry due to its
nutritional, functional and storage stability properties.
Delta 6-asid lemak desaturase dan delta 12-asid lemak desaturase merupakan enzim yang diperlukan bagi langkah desaturasi semasa proses biosintesis asid gamma-linolenik (GLA) oleh kulat oleaginus. Objektif kajian ini ialah untuk menganalisis profil pengekspresan gen mengekod enzim delta 6-asid lemak desaturase (des6) dan delta 12-asid lemak desaturase (des12) kulat oleaginus Cunninghamella bainieri semasa penghasilan GLA. Jujukan gen separa bersaiz 1372 pb bagi des6 dan 1008 pb bagi des12 telah dipencil daripada C. bainieri. Analisis pengekspresan gen menggunakan kaedah tindak balas berantai polimerase kuantitatif masa sebenar (RT-qPCR) menunjukkan perubahan kadar pengekspresan des6 adalah lebih tinggi berbanding kadar pengekspresan des12 semasa penghasilan GLA. Pengekspresan des6 adalah tertinggi selepas 24 jam dikultur dalam medium penghasilan GLA. Namun, kadar pengekspresannya menurun hingga jam ke-96 pertumbuhan tetapi meningkat semula pada jam ke-120. Bagi des12, kadar pengekspresannya adalah lebih sekata dengan pengekspresan tertinggi dikesan pada jam ke-120. Analisis penghasilan GLA menunjukkan jumlah GLA dalam sel berkolerasi dengan kadar pengekspresan des6. Hasil kajian mencadangkan bahawa aras pengekspresan des6 adalah penting dalam menentukan aras GLA dalam C. bainieri.
The aim of this study was to investigate the effect of structural orientation on the impedance and piezoelectric properties
of Ka0.5Na0.5NbO3
(KNN) ceramic synthesized using modified sol-gel method. Dried xerogel was heated at 800o
C for 90
min and the aggregates were grinded to powder form. SEM micrographs confirmed that the powder consist of bimodal
particles in nm and μm size regimes. The powder was compacted into 13 mm diameter pellet and sintered at 1000o
C for
6 h. Then the pellets were poled at 4.0kV/mm at 100o
C for 30 min. The as-sintered pellets displayed different sizes of
cuboidal granules forming a relatively dense sample. The XRD and Raman spectroscopy results confirmed the formation
of perovskite KNN with monoclinic crystal structure. The compositional analysis using Vegard’s law showed that the
K:Na ratio was 0.5:0.5. Dramatic intensity enhancement in (110) reflection and subsequent reduction in (100) reflection
as observed in X-ray diffractograms for the poled pellet suggest permanent shift in crystal orientation. Consequently,
the Nyquist impedance plot of a Debye type semicircular arc was altered to a combination of a depressed semicircular
arc. Unlike the initial plot, the real impedance, Z′ exhibited frequency dependence at low frequency regime. In addition,
the relaxation time, τ of KNN sample shifted to lower frequency after the structural re-orientation while piezoelectric
constant, d33 along (110) direction significantly improved from 5 to 35 pC/N.
Kami melaporkan hasil kajian terhadap nanokomposit Ag-ZnO dengan nisbah berat yang berbeza bagi Ag:ZnO (0:10,
7:10 & 25:10) yang telah disediakan melalui kaedah sonokimia. Kajian fotomangkin terhadap nanokomposit Ag-ZnO
menunjukkan peningkatan kecekapan fotomangkin terhadap foto-penguraian larutan akues metilena biru berbanding
nanobahan ZnO tulen di bawah penyinaran cahaya nampak. Sampel Ag-ZnO pada nisbah 7:10 menunjukkan aktiviti
fotomangkin terbaik dan mencapai kadar penguraian sehingga 94% bagi tempoh masa penguraian selama 80 min,
diikuti 86% bagi sampel ZnO tulen dengan menggunakan kaedah yang sama. Morfologi, struktur bahan, sifat optik dan
kehabluran bagi nanokomposit Ag-ZnO juga dibincangkan menerusi data yang diperoleh melalui mikroskop elektron
transmisi, spektroskopi ultralembayung-cahaya nampak dan difraktometer analisis sinar-X. Hasil kajian menunjukkan
bahawa dengan penambahan zarah Ag kepada ZnO telah meningkatkan kadar serapan cahaya bagi ZnO di kawasan
cahaya nampak dan meningkatkan kadar pemisahan cas foto-aruhan bagi menghasilkan rawatan air tercemar pewarna
yang lebih baik.
Penyelidikan ini dijalankan bagi mengkaji sifat mekanik nanokomposit epoksi berpenguat gentian hibrid nano tiub
karbon berbilang dinding (MWCNT) dan nanozarah tanah liat (NC). Nanokomposit berpenguat hibrid nanozarah telah
disediakan melalui kaedah kacauan mekanik dan sampel dengan jumlah nanozarah berbeza dibentuk menggunakan
pengacuan mampatan. Dalam ujian lenturan yang dijalankan, didapati sampel hibrid memberikan nilai kekuatan
yang lebih tinggi berbanding sampel tunggal. Ujian terhadap sifat hentaman nanokomposit epoksi berpenguat gentian
nanozarah menunjukkan bahawa penambahan gentian terhadap sampel tidak dapat meningkatkan sifat ketahanan daya
hentaman yang dikenakan. Namun demikian, sampel yang mengandungi gentian hibrid nano merekodkan nilai daya
tahan hentaman yang lebih tinggi berbanding sampel tunggal. Mikrograf pengimbas elektron (SEM) mengesahkan kesan
serakan pengisi hibrid dan ikatan antara muka dalam matriks yang baik. Ini membuktikan bahawa gentian hibrid antara
nanotiub karbon dan nanozarah tanah liat pada kandungan komposisi tertentu dapat menambahbaik sifat mekanik
bahan nanokomposit.
Blue-pea flower, turmeric, mulberries, brown rice, purple cabbage and Indian mulberry leave were successfully form on
TiO2 mesoporous film using immersion method to produce TiO2 mesoporous photoanode for natural dye sensitized solar
cells (DSSCs) assembly. The TiO2 mesoporous films were formed after calcinations at 450˚C for 30 min. The photoanodes
were dipped in different types of natural dye for 24, 72 and 120 h. The properties of natural dye were investigated by
ultraviolet-visible spectroscopy (UV-vis) and Fourier transform infrared spectroscopy (FTIR). From UV-Vis spectroscopy
analysis, the wavelength range of the natural dye studied in this research lays between 350 and 800 nm. The FTIR result
of the natural dye shows the present of intermolecular H-bond, C=O stretching vibration, C-O-C stretching vibration,
C=C bending and C-H bending which was due to the component of anthocyanin, carotenoids and chlorophyll. The
characterization including field emission scanning electron microscopy (FESEM), energy dispersive x-ray (EDX) and x-ray
diffraction (XRD) were carried out on the TiO2 mesoporous film. On the other hand, the conductivity of electrolyte for
liquid electrolyte, gel electrolyte and solid electrolyte were also investigated. Gel electrolyte has the highest conductivity,
26.1 mS/cm while liquid electrolyte and solid electrolyte obtained 17.34 and 0.45 mS/cm, respectively. Finally, solar
cells were prepared by sandwiching the TiO2 mesoporous photoanode with Platinum (Pt) counter electrode. The results
showed short circuit current, open circuit current voltage, fill factor and efficiency for all samples during the present of
light. The highest efficiency was obtained from Blue-pea sample that immersed for 120 h with 0.123% efficiency.
In this study, zinc oxide (ZnO) nanorod arrays were synthesized using a simple hydrothermal reaction on a ZnO seeds/
ITO substrate and applied for the fabrication of enzymatic glucose sensor. ZnO nanorod matrix provided a favourable
environment for the immobilization of glucose oxidase (GOx) and introduced a shuttling way for electronic communication
between GOx and electrode. The performance of different aspect ratio of ZnO nanorods that was produced by varying
hydrothermal reaction time was studied. The aspect ratio of ZnO influenced the GOx enzyme immobilization. The
morphology and structure of prepared ZnO nanorods were characterized by employing scanning electron microscopy
(SEM), and X-ray powder diffraction (XRD). Electrochemical measurements of the sensor showed a reproducible sensitivity
of 2.06 μA/cm2
mM for ZnO matrix grown for 4 h with the aspect ratio of 8.0.
Distribution of gold nanoparticles (AuNPs) on a substrate becomes crucial in nanotechnology applications. This work
describes a route to fabricate AuNPs directly on silicon substrates by using an aluminum template in hydrothermal reaction
at 80°C for 1 h. The effect of aluminum nitrate (Al(NO3
)3
) concentration in the hydrothermal bath was investigated. The
properties of AuNPs were studied using field-emission scanning electron microscope (FESEM), x-ray diffractometer (XRD)
and semiconductor characterization system (SCS). Two distinct sizes of AuNPs were observed by FESEM. XRD analysis
proved the formation of AuNPs directly on the substrate. AuNPs were embedded between polymethylsilsesquioxane
(PMSSQ) in order to investigate their effect on memory properties. The sample grown in 0.1 M Al(NO3
)3
exhibited the
largest hysteresis window (2.6 V) and the lowest Vth (2.2 V) to turn ‘ON’ the memory device. This indicated that good
distribution of FCC structure AuNPs with 80±4 nm and 42±7 nm of large and small particles produced better charge storage
capability. Charge transport mechanisms of AuNPs embedded in PMSSQ were explained in details whereby electrons from
Si are transported across the barrier by thermionic effects via field-assisted lowering at the Si-PMSSQ interface with the
combination of the Schottky and Poole Frenkel emission effect in Region 1. Trapped charge limited current (TCLC) and
space charge limited current (SCLC) transport mechanism occurred in Region 2 and Region 3.
The effect of addition of avocado (Persea americana) puree on the physical and microstructure of butter cake was studied.
Butter cakes were made by replacing butter with 10, 30 and 50% of avocado puree. Physical properties including batter
specific gravity, volume, colour and image analysis of cellular structure of the crumb were analyzed. Texture profile
analysis was determined using texture analyzer. The results showed that with the increased amount of avocado puree,
the batter specific gravity increased while volume of the cakes reduced. The texture profile analysis showed that the cakes
became harder as the amount of avocado puree increased, while cohesiveness was not affected. The cellular structure of
the crumb exhibited a decrease in the number of air cells while the average cell size increased with addition of avocado
puree. The colour analysis showed that the cake crumb became darker as the aavocado puree was increased.
This study aimed to resolve the taxonomic status of a morphologically undetermined sea cucumber species of order Apodida
from Malaysia (GenBank accession no.: FJ223867) using partial 16S mitochondrial rRNA gene sequences and subsequently
to determine the validity of morphological taxonomy of Holothuria species into its current subgenera. The undetermined
species clustered with all taxa of Holothuria in previous study. Phylogenetic analyses using maximum parsimony and
Bayesian methods suggest that the undetermined species was genetically closer to Holothuria (Lessonothuria) pardalis and
Holothuria (Acanthotrapeza) coluber; and its position in both phylogenetic trees further suggests its status as a Holothuria
taxon. Subgenera of Holothuria, Merthensiothuria and Metriatyla are monophyletic with strong bootstrap supports and
posterior probabilities of clades, thus strengthening their morphological taxonomies. Nonetheless, the non-monophyly of
subgenera of Halodeima, Microthele and Platyperona suggests a requirement for their taxonomic revisions using integrative
taxonomy. The status of Holothuria (Halodeima) edulis subgroups in the maximum parsimony and Bayesian trees is
indistinct and further taxonomic revisions are necessary. In terms of sister relationship, both phylogenetic trees suggest
that subgenus Holothuria is a sister taxon of subgenus Roweothuria while the other sister relationships were unclear due
to the undetermined species, paraphyly and polyphyly of a number of subgenera. Further studies with more specimens of
genus Holothuria from broader geographical locations and various mtDNA genes along with morphological approaches
may facilitate to provide better insights into the molecular phylogeny of subgenera of Holothuria.
A study of spatial and temporal variations on water quality and trophic status was conducted twice a month from December
2012 to January 2014 in four sampling stations at Bukit Merah Reservoir (BMR). The concentration of dissolved oxygen
(DO), water temperature, conductivity, total dissolved solids (TDS), total phosphorous (TP), PO4
-
, NO2
-
, NO3
-
, NH4
+ and
net primary productivity had significant differences temporally (p<0.05) except for pH, total suspended solids (TSS)
and chlorophyll-a. Based on correlation analysis, the amount of rainfall and rain days has negatively correlated with
secchi depth and chlorophyll-a (p<0.01). The water level has significantly decreased the value of the temperature, pH,
conductivity, TP and NO2
-
but it has positive correlation with NO3
-
and NH4
+. Discharged from Sungai Kurau increased
the value of conductivity, TSS, TP and NO2
-
as a result from runoff and erosion, thus decreasing the secchi depth values,
NO3
-
and NH4
+. The water quality of BMR is classified in Class II and TSI indicates that the BMR has an intermediate level
of productivity (mesotrophic) and meets the objective of this reservoir which was to provide water for paddy irrigation.
MeSH terms: Chlorophyll; Oxygen; Rain; Temperature; Water; Water Quality
Beberapa siri pengiraan ab-initio telah dijalankan bagi meneliti perubahan bentuk struktur dan ciri elektronik noktah kuantum silikon berdasarkan kesan pempasifan bahan bukan organik, hidroksil (OH) dan bahan organik, metil (CH3). Hasil pengoptimuman geometri menunjukkan bahawa noktah kuantum yang dipasifkan secara tepu dengan bahan organik dan bukan organik perlu menjalani proses penstrukturan semula keadaan permukaan bagi membolehkan pempasifan permukaan tepu dijalankan tanpa meninggalkan sebarang ikatan terjuntai. Kajian juga mendapati bahawa panjang ikatan meningkat pada ikatan silikon-hidroksil pada permukaan noktah kuantum. Manakala, herotan diperhatikan semasa proses pengenduran dinamik di bahagian teras noktah kuantum. Bagi pempasif metil pula, peningkatan ikatan silikon-metil pada permukaan meningkat lebih ketara, sementara pembentukan geometri tetrahedral pada bahagian teras dikekalkan. Hal ini menyumbang kepada kesan pengurungan elektron yang lebih jelas. Ringkasnya, kedua-dua jenis pempasif memberikan kesan perubahan penting pada ciri elektronik dalam tiga perspektif. Pertama, terdapat pengurangan nilai jurang tenaga apabila bahan pempasif yang digunakan mempunyai darjah kebebasan pergerakan yang sangat dinamik menyebabkan pengherotan pada bahagian teras. Kedua, walaupun kehadiran kedua-dua pempasif mempengaruhi nilai jurang tenaga, namun ia tetap menunjukkan sifat elektronik tenaga jurang-langsung. Ketiga, kewujudan jurang tenaga kecil juga diperhatikan agak ketara dalam jalur tenaga bagi noktah kuantum bersaiz kecil, dengan kesan kehadirannya boleh menyebabkan pengurangan hasil kuantum semasa proses eksiton berlaku.
Keberkesanan perencatan benziltrietilamonium klorida (BK) terhadap perlindungan kakisan keluli karbon di dalam 1 M asid asetik telah dianalisis dengan menggunakan kaedah ujian kehilangan berat. Matlamat kajian adalah untuk menilai tahap kecekapan perencatan BK berdasarkan perubahan nilai kepekatan perencat berkenaan dan suhu. Analisis kehilangan berat menunjukkan kadar kakisan keluli karbon berjaya dikurangkan dengan penggunaan kepekatan BK yang lebih tinggi dan nilai kecekapan perencatan BK mencapai sehingga 70%. Namun kadar kakisan didapati meningkat selari dengan peningkatan suhu. Analisis termodinamik mendapati perencatan BK berjaya mengurangkan proses pelarutan ion-ion logam melalui pembentukan lapisan filem nipis pada permukaan keluli karbon. Analisis juga menunjukkan sebatian BK berupaya menjerap pada permukaan keluli karbon melalui kedua-dua kaedah penjerapan fizikal dan kimia. Proses penjerapan BK pada permukaan keluli karbon didapati lebih menjurus kepada model isoterma penjerapan Langmuir. Analisis morfologi menggunakan mikroskop imbasan elektron turut mengesahkan berlakunya perencatan BK pada tapak permukaan keluli karbon. Keseluruhan kajian mendapati sebatian BK berupaya melindungi keluli karbon daripada mengalami kakisan di dalam medium asid asetik.
A comprehensive survey and descriptions on the petiole anatomy was undertaken on 16 species belonging to four selected genera (Anisoptera, Cotylelobium, Vatica and Upuna) in the tribe Dipterocarpeae to investigate variations in vascular bundle structure. Methods used in this study were petiole sectioning using a sliding microtome, staining, mounting and observation under light microscope. Findings had shown that all species studied have complex vascular bundle structures, consisting of outer and medullary vascular bundles. Four different types of vascular bundle arrangements were found and described as Types 1, 2, 3 and 4. The vascular bundle types were determined based on the arrangement and system of vascular bundle strands present in the petiole transverse sections. These vascular bundle types were determined and suggested for easy reference. The results showed that vascular bundles can be used for identification of certain species and can definitely be used for classification of different genera. The presence of sclerenchyma cells is useful in differentiating genera. As a conclusion, the petiole vascular bundle anatomical characteristics have taxonomic value, especially in the identification of some species and possibly applicable in the classification of the tribe Dipterocarpeae.
MeSH terms: Animals; Cell Count; Histological Techniques; Humans; Surveys and Questionnaires; Staining and Labeling; Population Groups; Dipterocarpaceae; Odonata
This study aimed to determine the antioxidant capacity, total polyphenolic and total flavonoid content of Malaysian young corn ear (YCE) and its cornsilk (CS) of different varieties. Three different varieties of YCE and its CS locally grown in Malaysia were chosen namely Big Fruit, Thai Supersweet and Bi-color. CS Bi-color displayed the highest total phenolic content (143.58 mg GAE/g extract) while CS Thai Supersweet exhibited the highest total flavonoid content (26.63 mg CAE/g extract). Meanwhile, YCE of Bi-color variety demonstrated the highest total polyphenolic and flavonoid content (92.64 and 18.14 mg CAE/g extract, respectively) compared to other YCE varieties. At 800 μg/mL, CS of Bi-color (93.82%) recorded the strongest electron donor due to higher DPPH scavenging activity, followed by CS Thai Supersweet (92.87%), YCE Bi-color (41.94%), YCE Thai Supersweet (28.87%), CS Big Fruit (28.87%) and YCE Big Fruit (21.38%). For FRAP, CS of Bi-color showed the highest reducing power activity (65.46%) among all the crude extracts. There is a significant correlation between total polyphenolic content, DPPH free radical scavenging activity and FRAP of YCE and CS of different varieties. In summary, CS extracts are the potential ingredient to be applied in food industries and at the same time reducing agriculture wastage.