Nitrate simultaneously induced NADH- and NADPH-nitrate reductase activities in rice seedlings. Chloramphenicol, other organic nitro-compounds such as o-nitroaniline and 2,4-dinitrophenol and nitrite also induced nitrate reductase in rice seedlings. The nitrate- or nitrite-induced nitrate reductase could accept electrons more efficiently from NADH than NADPH. However, when this enzyme was induced by organic nitro-compounds, it could accept electrons more efficiently from NADPH than NADH.
A flow injection analysis (FIA) procedure for the determination of anisidine value (AV) in palm olein using a triiodide detector is described. Undiluted oil sample and chloramine-T reagent were added to a reaction chamber, and reaction was accelerated by applying a short vortex action (typically for 30 s). After allowing the emulsified oil phase to be separated from the aqueous phase (bottom layer), an aliquot of the aqueous phase (containing unreacted chloramine-T) was aspirated into a carrier stream that contained I(-) where the chloramine-T oxidized the I- to form I3(-) which was finally detected by a flow-through triiodide potentiometric detector. Variables that affect the FIA signals such as size of the reaction chamber, oil and reagent flow rates, chloramine-T concentration, vortex time, time for phase separation, carrier stream pH and injected volume were studied. The optimized FIA procedure is linear over 1.0-23.0 AV. The method exhibits good repeatabililty (R.S.D. of +/-3.16% (n = 4) for the determination of 5.0 AV) and a sampling rate of 40 samples per hour was achieved. Good correlation (r2 = 0.996 (n = 4)) between the proposed method and the manual American Oil Chemists' Society procedure was found when applied to the determination of twenty different types of palm olein samples.
Extending the frying-life of oils is of commercial and economic importance. Due to this fact, assessment on the thermal stability of frying oils could provide considerable savings to the food processors. In this study, the physico-chemical properties of five palm products mainly palm oil, single-fractionated palm olein, double-fractionated palm olein, red palm olein and palm-based shortening during 80 hours of heating at 180 degrees C were investigated. Heating properties of these products were then compared with that of high oleic sunflower oil, which was used as reference oil. The indices applied in evaluating the quality changes of oils were free fatty acid, smoke point, p-anisidine value, tocols, polar and polymer compounds. Three palm products i.e. palm oil, single-fractionated palm olein and double-fractionated palm olein were identified to be the most stable in terms of lower formation of free fatty acid, polar and polymer compounds as well as preserving higher smoke point and tocols content compared to the other three oils. The low intensity of hydrolytic and oxidative changes due to prolonged heating, suggests that these palm products are inherently suitable for frying purposes.
Polyaniline (PANI) and polyaniline composites with aluminium oxide (Al2O3) were prepared using the in situ polymerization method. The composites were then blended with acrylic paint and applied to carbon steel panels. The coated steel panels were evaluated for corrosion using the immersion test technique. The results revealed that the steel panels coated with polyaniline composites and with Al2O3 containing coatings had small corrosion as compared to the bare sample and the samples coated with polyaniline and paint alone. The samples were characterized by Fourier transform infrared (FTIR) and X-ray diffraction(XRD). In addition, the morphology of the finished samples was observed using the scanning electron microscopy (SEM). This novel composite was used as a paint pigment for enhancing the barrier properties and the paint protectable against aggressive ions. Meanwhile, corrosion was evaluated through visual monitoring using a digital camera after 60 days of fully immersion test in 5% NaCl. The weight loss method was also used to evaluate corrosion.
In-situ polymerization method was used to prepare palm-based polyurethane (PU) composites loading with 15 wt% magnetite (Fe3O4), polyaniline (PANI) and Fe3O4 coated with PANI labeled as PU15, PP and PPM, respectively. FTIR spectroscopy analysis indicated a shift in the carbonyl, C=O and NH in PP. The shift of the peak indicated that there was hydrogen bonding between the C=O (proton acceptor) of urethane with NH (proton-donator) of PANI. PPM gave the highest impact and flexural strengths at 4875 kJ/ m2 and 42 MPa, respectively but with the lowest flexural modulus (1050 MPa). Two-stage degradation behavior was observed in the TGA thermogram.
The influence of PANI additions on methanol sensing properties of ZnO thin films at room temperature had been investigated. Commercial polyaniline powder (PANI) was mixed into 3 mL ZnO solution in five different weight percentages namely 1.25, 2.50, 3.75, 5.00 and 6.25% to obtain ZnO/PANI composite solutions. These solutions were spin coated onto glass substrate to form thin films. Microstructural studies by FESEM indicated that ZnO/PANI films showed porous structures with nanosize grains. The thickness of the film increased from 55 to 256 nm, proportionate to increment of PANI. The presence of 2 adsorption peaks at ~310 nm and ~610 nm in UV-Vis spectrum proved that addition of PANI has modified the adsorption peak of ZnO film. Methanol vapour detection showed that addition of PANI into ZnO dramatically improved the sensing properties of the sensor. The sensors also exhibited good repeatability and reversibility. Sensor with the amount of PANI of 3.75 wt% exhibited the highest sensitivity with response and recovery time was about 10 and 80 s, respectively. The possible sensing mechanism of the sensor was also discussed in this article.
Two inorganic pigments (TiO2 and SiO2) were used to prepare composites with polyaniline (PANI) by situ polymerization method. PANI and PANI composites with SiO2 and TiO2 were characterized using Fourier transform infrared spectroscopy and X-ray diffraction. The morphology of the synthesized pigments (PANI , PANI-SiO2 and PANI-TiO2) was examined using scanning electron microscopy. Samples were then used as pigments through blending them with acrylic paint and applied on the surface of carbon steel panels. Corrosion was evaluated for coating of carbon steel panels through full immersion test up to standard ASTMG 31. Mass loss was calculated after they have been exposed in acidic media. A digital camera was also used for monitoring corrosion visually on the surface of carbon steel specimens. The results revealed that acrylic paint pigmented by PANI-SiO2 composite was more efficient in corrosion protection for carbon steel compared with the other synthesized pigments.
In order to overcome the stability problems of oils and fats, synthetic antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert-butyl hydroquinone (TBHQ) have widespread use as food additives in many countries. Recent reports reveal that these compounds may be implicated in many health risks, including cancer and carcinogenesis. Hence, there is a move towards the use of natural antioxidants of plant origin to replace these synthetic antioxidants.
A study on the leaves of Aglaia exima led to the isolation of one new and seven known compounds: six triterpenoids and two steroids. Their structures were elucidated and analyzed mainly by using spectroscopic methods; 1D and 2D NMR, mass spectrometry, UV spectrometry and X-ray. All the triterpenoids and steroids were measured in vitro for their cytotoxic activities against eight cancer cell lines; lung (A549), prostate (DU-145), skin (SK-MEL-5), pancreatic (BxPC-3), liver (Hep G2), colon (HT-29), breast (MCF-7) and (MDA-MB-231). The new cycloartane triterpenoid, 24(E)-cycloart-24-ene-26-ol-3-one 1, showed potent cytotoxic activity against colon (HT-29) cancer cell line (IC(50) 11.5μM).
The Malayan gaur (Bos gaurus hubbacki) or Seladang is classified as vulnerable by the International Union for Conservation of Nature and Natural Resources (IUCN). The Malayan gaur is mainly distributed in the tropical woodlands of Peninsular Malaysia and Southern Thailand. The aim of this study was to collect, analyze and cryopreserve the semen of wild Malayan gaur. Transrectal massage (TM) and electroejaculation (EEJ) technique was applied in semen collection of the Malayan gaur. The semen was then cryopreserved in liquid nitrogen using slow freezing technique. Makler counting chamber was used to evaluate sperm concentration and motility, while the sperm viability and morphology of fresh and post-thaw sperm was determined using eosin-nigrosin staining protocol. As a result, we have successfully collected the Malayan gaur semen using EEJ technique. Sperm motility, viability and morphological changes of the post-thaw semen of Malayan gaur were found undesirable due to the complication of the cryopreservation process. On the basis of current study it can be concluded that Malayan gaur bulls semen can be obtain by EEJ with no evidence of rectal trauma. Optimization of the process of cryopreservation for Malayan gaur sperm is needed to maintain the cryoviability of the good sperm quality. The data generated in this study would be useful in conservation of genetic diversity program for Malayan gaur.
The aim of this research was to investigate the ability of organometallic titanium-PANi hybrid materials as gas sensor at room temperature. To form the hybrid materials, commercially available polyaniline (PANi) powder were directly added into organometallic titanium sols which was synthesized using the sol gel method. The composite films were prepared via spin coating technique followed by electrode deposition for sensors fabrication. Five different organometallic titanium:PANi ratios namely 1 wt% to 5 wt% of PANi were prepared for this experiment. For gas sensing test, all samples were exposed to ethanol vapour. The sensing mode is based on the variation in the electrical conductivity due to the
interaction between the gas molecules and the film. It was observed that the composite sensors required appropriate ratio to exhibit optimum sensing properties. This finding proved that the hybridization process is successful and offered much cheaper and easier method for fabrication of room temperature gas sensor.
Microencapsulated paraffin wax/polyaniline was prepared using a simple in situ polymerization technique, and its performance characteristics were investigated. Weight losses of samples were determined by Thermal Gravimetry Analysis (TGA). The microencapsulated samples with 23% and 49% paraffin showed less decomposition after 330 °C than with higher percentage of paraffin. These samples were then subjected to a thermal cycling test. Thermal properties of microencapsulated paraffin wax were evaluated by Differential Scanning Calorimeter (DSC). Structure stability and compatibility of core and coating materials were also tested by Fourier transform infrared spectrophotometer (FTIR), and the surface morphology of the samples are shown by Field Emission Scanning Electron Microscopy (FESEM). It has been found that the microencapsulated paraffin waxes show little change in the latent heat of fusion and melting temperature after one thousand thermal recycles. Besides, the chemical characteristics and structural profile remained constant after one thousand thermal cycling tests. Therefore, microencapsulated paraffin wax/polyaniline is a stable material that can be used for thermal energy storage systems.
Kafein mempunyai kesan ergogenik terhadap golongan yang terlatih; walaubagaimanapun, kajian kesan fisiologi kafein terhadap golongan sedentari adalah amat terhad. Tujuan kajian ini adalah untuk mengkaji kesan kafein ke atas penggunaan oksigen dan tanggapan tahap lesu semasa senaman intensiti sederhana dalam kalangan dewasa muda perempuan yang sedentari. Subjek terdiri daripada 16 orang mahasiswi yang berumur antara 22 hingga 24 tahun. Kriteria penerimaan adalah tahap aktiviti fizikal yang rendah dan pengambilan kafein adalah kurang daripada 50 mg sehari, disaring dengan menggunakan Soal Selidik Aktiviti Fizikal Antarabangsa (versi pendek) dan soal selidik pengambilan kafein. Reka bentuk kajian eksperimental ini adalah buta tunggal, pindah silang, kawalan plasebo dengan semua subjek menjadi kawalannya tersendiri. Subjek dikehendaki malaporkan diri ke makmal untuk menjalankan dua sesi eksperimen selepas masing-masing mengambil kapsul plasebo atau kafein dengan selang masa 3 hari antara dua sesi eksperimen tersebut. Enam puluh minit selepas mengambil kapsul plasebo (Glucolin, glukosa) atau 100 mg kafein (Pro-plus, United Kingdom), subjek dikehendaki berlari di atas treadmill selama 30 minit pada kuasa kerja yang bersamaan 60% daripada anggaran maksimum kadar denyutan jantung. Penggunaan oksigen, kadar denyutan jantung dan tanggapan tahap lesu direkod pada minit ke-20, ke-25 dan ke-30, manakala tekanan darah direkod serta-merta selepas subjek menghabiskan larian. Perbezaan direkod selepas kesemua subjek menyempurnakan kedua-dua eksperimen plasebo dan kafein. Min peratus lemak tubuh subjek adalah 28.4 ± 5.4. Ujian t bersandar menunjukkan tiada perbezaan signifikan antara trial plasebo dengan trial kafein ke atas penggunaan oksigen (13.99 ± 2.47 vs 14.49 ± 1.73, p = 0.440), tanggapan tahap lesu (12.3 ± 2.5 vs 12.3 ± 2.1, p = 1.000), tekanan darah sistolik (113 ± 10 vs 117 ± 11, p = 0.129), tekanan diastolik (67 ± 8 vs 69 ± 10, p = 0.408) dan kadar denyutan jantung (127.3 ± 11.0 vs 127.1 ± 11.6, p = 0.912). Terdapat korelasi negatif tinggi yang signifikan antara peratusan lemak tubuh dengan pengambilan oksigen (r = –0.568, p < 0.05) serta korelasi positif tinggi yang signifikan antara peratusan lemak tubuh dengan tanggapan tahap lesu (r = 0.515, p < 0.05). Hasil kajian tidak meningkatkan kesan yang signifikan mungkin disebabkan oleh kesan saiz (effect size) kajian ini yang kecil (d = 0.24). Justeru itu, kajian masa depan yang melibatkan lebih ramai subjek harus dijalankan untuk mengkaji kesan kafein semasa senaman dalam kalangan populasi sedentari.
A study to measure frying quality and stability of rice bran oil (RBO) compared to palm olein (PO) was conducted. The oils were used to fry French fries continuously for six hours a day up to five days at a temperature of 185 ± 5°C. Oil samples were collected and analyzed for free fatty acid (FFA), peroxide value (PV), smoke point, p-anisidine value (p-AV), iodine value (IV) and colour. At the end of the frying period for both oil samples, FFA, PV, colour and p-AV were increased whereas the IV and smoke point decreased. The rate of FFA formation of RBO was slightly lower which increased from 0.142% to 0.66% compared to PO which was from 0.079% to 0.93%. The PV of RBO showed consistent increased from 3.9 meq/kg to 13.4 meq/kg whereas PO with initial value at 3.4 meq/kg increased to 34.6 meq/kg on the fifth day. Smoke point of RBO and PO progressively dropped from 235°C to 188°C and 220°C to 178°C, respectively. The level of p-AV for RBO increased from 12.19 to 32.65 from the initial to the end of frying day whereas PO had higher rate of changes in p-AV which was from 10.45 to 60.75. The IV decreased over frying time where IV of RBO decreased from 94.5 to 66.5 while IV of PO decreased from 50.9 to 44.6. The colour of RBO showed increased in redness and yellowness but PO was darker at the end of the frying trial. In general, RBO showed better stability than the PO in deep frying of French fries.
Poly-vinyl-pyrrolidone (PVP)/polyaniline based surface acoustic wave (SAW) sensors were fabricated and characterized and their performances towards hydrogen gas were investigated. The PVP/polyaniline fibers composite were prepared by electrospinning of the composite aqueous solution deposited directly onto the active area of SAW transducers. Via scanning electron microscopy (SEM), the morphology of the deposited nanostructure material was observed. From the dynamic response, frequency shifts of 6.243 kHz (1% H2) and 8.051 kHz (1% H2) were recorded for the sensors deposited with PVP/ES and PVP/EB, respectively.
With the concern of adverse effects of lipid oxidation on food deterioration and human health, the antioxidant activities of kenaf seed extracts (KSE), roselle seed extracts (RSE) and roselle extracts (RE) were evaluated by comparing its oxidative stability in refined, bleached & deodorised (RBD) sunflower oils with that of in synthetic antioxidant, BHA. Established methods such as peroxide values (PV), p-anisidine values (AV), TOTOX values, free fatty acids (FFA), iodine values (IV), total phenolic contents (TPC), conjugated dienes (CD) and conjugated triene (CT) were employed to assess the extent of oil deterioration. During 24 days storage, consensus was accomplished based on the results assessed by PV, TOTOX, CD, CT, IV and TPC at which the antioxidant activities of KSE, RSE and RE were better than BHA. Surprisingly, the results obtained by AV and FFA assays showed the reversed. Among the extracts, RSE exhibited the best antioxidant activities. These suggest that KSE, RSE and RE may be used as potential source of natural antioxidants in the application of food industry to prevent lipid oxidation.
Binary blends of palm olein (PO) with sunflower oil (SFO), canola oil (CNO), and cottonseed oil (CSO) were formulated to assess their stability under continuous frying conditions. The results were then compared with those obtained in PO. The oil blends studied were: (1) 60:40 for PO + SFO; (2) 70:30 for PO + CNO; and (3) 50:50 for PO + CSO. The PO and its blends were used to fry potato chips at 180°C for a total of 56 h of operation. The evolution of analytical parameters such as tocols, induction period, color, p-anisidine value, free fatty acid, smoke point, polar compounds, and polymer compounds were evaluated over the frying time. Blending PO with unsaturated oils was generally proved to keep most qualitative parameters comparable to those demonstrated in PO. Indeed, none of the oils surpassed the legislative limits for used frying. Overall, it was noted that oil containing PO and SFO showed higher resistance toward oxidative and hydrolytic behaviors as compared to the other oil blends.
A simple visual ethanol biosensor based on alcohol oxidase (AOX) immobilised onto polyaniline (PANI) film for halal verification of fermented beverage samples is described. This biosensor responds to ethanol via a colour change from green to blue, due to the enzymatic reaction of ethanol that produces acetaldehyde and hydrogen peroxide, when the latter oxidizes the PANI film. The procedure to obtain this biosensor consists of the immobilization of AOX onto PANI film by adsorption. For the immobilisation, an AOX solution is deposited on the PANI film and left at room temperature until dried (30 min). The biosensor was constructed as a dip stick for visual and simple use. The colour changes of the films have been scanned and analysed using image analysis software (i.e., ImageJ) to study the characteristics of the biosensor's response toward ethanol. The biosensor has a linear response in an ethanol concentration range of 0.01%-0.8%, with a correlation coefficient (r) of 0.996. The limit detection of the biosensor was 0.001%, with reproducibility (RSD) of 1.6% and a life time up to seven weeks when stored at 4 °C. The biosensor provides accurate results for ethanol determination in fermented drinks and was in good agreement with the standard method (gas chromatography) results. Thus, the biosensor could be used as a simple visual method for ethanol determination in fermented beverage samples that can be useful for Muslim community for halal verification.
The aim of the present study was to evaluate the effect of chicken nuggets addition on the degradation of canola oil during frying compared to the changes occurring when the same frying medium was simply heated at frying temperature as control. Heating or frying test was carried out at 185±5oC using electric fryer for 8 h/day for 3 consecutive days and the oil sample was collected every 4 h. The changes in fatty acids composition and physicochemical properties of the oil samples during frying and controlled heating experiments were monitored. In this study, refractive index, free fatty acid content, peroxide value, p-anisidine value, polar compounds and viscosity of the oils all increased, whereas iodine value and C18:2/C16:0 ratio decreased as heating or frying progressed. The percentage of linoleic acid tended to decrease, whereas the percentages of palmitic acid increased. Gas chromatography analysis revealed that adding chicken nuggets to heated canola oil led to higher decrease in the ratio of C18.2/C16:0 compared to what was measured when the fat alone was heated at frying temperature. The presence of chicken nuggets accelerates the formation of polymerization products and polar compounds in canola oil during frying.
Aloe emodin, an anthraquinone of Aloe barbadensis Miller has been shown to have more cytotoxic effect in
different kinds of human cancer cell lines compared to normal. Accordingly, we found it to selectively inhibit
the proliferation of oestrogen-receptor-positive-(ER+)-breast cancer cells, MCF-7; but not controls cells,
MCF-10A. However, its precise mechanism is not well understood. Several studies have shown that there is
evidence of increased intracellular calcium (Ca2+), both at early and late stage of apoptosis which associated
with the down-regulation of ERK1/2 proliferative pathway. Therefore, we aim to elucidate the involvement
of intracellular Ca2+ in aloe emodin induced apoptosis on MCF-7. Apoptotic morphological changes were
observed under fluorescence microscope. The involvement of cytoplasmic Ca2+ and MAPKs were investigated
using Fluo-4 intracellular Ca2+ imaging and QuantiGene 2.0 Plex assay, respectively. IC50 of aloe emodin
(80 μM) at 72 hours incubation was used. Data were evaluated using the one-way or two-way ANOVA tests.
Our results indicated that aloe emodin at IC50 80µM induced apoptosis on MCF-7 through the association of
intracellular Ca2+ signalling. This observation include a significant increased (p