Displaying publications 2541 - 2560 of 2920 in total

Abstract:
Sort:
  1. Secretory expression of thermostable T1 lipase through bacteriocin release protein
    Rahman RN, Leow TC, Basri M, Salleh AB
    Protein Expr Purif, 2005 Apr;40(2):411-6.
    PMID: 15766884
    The extracellular production of T1 lipase was performed by co-expression of pJL3 vector encoding bacteriocin release protein in prokaryotic system. Secretory expression was optimized by considering several parameters, including host strains, inducer (IPTG) concentration, media, induction at A(600 nm), temperature, and time of induction. Among the host strains tested, Origami B excreted out 18,100 U/ml of lipase activity into culture medium when induced with 50 microM IPTG for 12 h. The Origami B harboring recombinant plasmid pGEX/T1S and pJL3 vector was chosen for further study. IPTG at 0.05 mM, YT medium, induction at A(600 nm) of 1.25, 30 degrees C, and 32 h of induction time were best condition for T1 lipase secretion with Origami B as a host.
    Matched MeSH terms: Temperature
  2. Fulltext Once- and twice-daily heat acclimation confer similar heat adaptations, inflammatory responses and exercise tolerance improvements
    Willmott AGB, Hayes M, James CA, Dekerle J, Gibson OR, Maxwell NS
    Physiol Rep, 2018 Dec;6(24):e13936.
    PMID: 30575321 DOI: 10.14814/phy2.13936
    This experiment aimed to investigate the efficacy of twice-daily, nonconsecutive heat acclimation (TDHA) in comparison to once-daily heat acclimation (ODHA) and work matched once- or twice-daily temperate exercise (ODTEMP, TDTEMP) for inducing heat adaptations, improved exercise tolerance, and cytokine (immune) responses. Forty males, matched biophysically and for aerobic capacity, were assigned to ODHA, TDHA, ODTEMP, or TDTEMP. Participants completed a cycling-graded exercise test, heat acclimation state test, and a time to task failure (TTTF) at 80% peak power output in temperate (TTTFTEMP : 22°C/40% RH) and hot conditions (TTTFHOT : 38°C/20% RH), before and after 10-sessions (60 min of cycling at ~2 W·kg-1 ) in 45°C/20% RH (ODHA and TDHA) or 22°C/40% RH (ODTEMP or TDTEMP). Plasma IL-6, TNF-α, and cortisol were measured pre- and postsessions 1, 5, and 10. ODHA and TDHA induced equivalent heat adaptations (P  0.05) following ODHA (+14 ± 4%), TDHA (14 ± 8%), ODTEMP (9 ± 10%) or TDTEMP (8 ± 13%). Acute (P  0.05) increases were observed in IL-6, TNF-α, or cortisol during ODHA and TDHA, or ODTEMP and TDTEMP. Once- and twice-daily heat acclimation conferred similar magnitudes of heat adaptation and exercise tolerance improvements, without differentially altering immune function, thus nonconsecutive TDHA provides an effective, logistically flexible method of HA, benefitting individuals preparing for exercise-heat stress.
    Matched MeSH terms: Body Temperature Regulation
  3. Fulltext Endoscopy gender determination and reproductive hormone profiles of Painted Terrapins (Batagur borneoensis) subjected to ex situ incubation
    Kolandaiveloo V, Kalaiselvam R, Fong MWC, Mustapa MS, Souce RM, Sugnaseelan S, et al.
    J Vet Med Sci, 2020 Apr 15;82(4):497-502.
    PMID: 32101821 DOI: 10.1292/jvms.19-0477
    Chelonian exhibit temperature dependent sex determination, and ex situ incubation of eggs in conservation hatcheries may render a gender bias. The gender of juvenile Painted terrapins (Batagur borneoensis) produced at a conservation hatchery in Malaysia was determined by endoscopy of the gonads. Circulating reproductive hormones (testosterone, progesterone and estradiol) were profiled for 31 juveniles and nine captive-reared non-breeding adult terrapins. Endoscopy revealed a gender bias of 96.8% (30/31) females. Testosterone levels in the juvenile females (2.49 ± 1.29) were significantly lower than that of the adult females (12.20 ± 4.29), and lower than values in the juvenile male (9.36) and adult males (27.60, 35.62). The progesterone levels in the juvenile females (107.12 ± 68.68) were significantly higher than that of the adult females (51.13 ± 24.67), but lower than values in the juvenile male (33.27) and adult males (3.43, 8.51). Estrogen levels were significantly lower in the juvenile females (1.57 ± 1.35) compared to the adult females (77.46 ± 53.45). Negative correlations were observed between levels of progesterone and testosterone, and progesterone and estrogen. A positive correlation was noted between estrogen and testosterone. The present study constitutes the first attempt to determine the gender and reproductive hormone profiles of juvenile Painted terrapins produced by ex situ incubation, and captive non-breeding adults. Endoscopy of the gonads is a useful techniques for gender determination among juvenile turtles, while the use of testosterone as a gender biomarker warrants further investigation.
    Matched MeSH terms: Temperature
  4. Fulltext Enrichment of Eucalyptus oil nanoemulsion by micellar nanotechnology: transdermal analgesic activity using hot plate test in rats' assay
    Aziz ZAA, Nasir HM, Ahmad A, Setapar SHM, Ahmad H, Noor MHM, et al.
    Sci Rep, 2019 Sep 23;9(1):13678.
    PMID: 31548590 DOI: 10.1038/s41598-019-50134-y
    Eucalyptus globulus is an aromatic medicinal plant which known for its 1,8-cineole main pharmacological constituent exhibits as natural analgesic agent. Eucalyptus globulus-loaded micellar nanoparticle was developed via spontaneous emulsification technique and further evaluation for its analgesic efficacy study, in vivo analgesic activity assay in rats. The nanoemulsion system containing Eucalyptus-micelles was optimized at different surfactant types (Tween 40, 60 and 80) and concentrations (3.0, 6.0, 9.0, 12.0, 15.0, and 18.0 wt. %). These formulations were characterized by thermodynamically stability, viscosity, micelles particle size, pH, and morphology structure. The spontaneous emulsification technique offered a greener micelles formation in nanoemulsion system by slowly titrated of organic phase, containing Eucalyptus globulus (active compound), grape seed oil (carrier oil) and hydrophilic surfactant into aqueous phase, and continuously stirred for 30 min to form a homogeneity solution. The characterizations evaluation revealed an optimized formulation with Tween 40 surfactant type at 9.0 wt. % of surfactant concentration promoted the most thermodynamic stability, smaller micelles particle size (d = 17.13 ± 0.035 nm) formed with spherical shape morphological structure, and suitable in viscosity (≈2.3 cP) and pH value (6.57) for transdermal purpose. The in vivo analgesic activity assay of optimized emulsion showed that the transdermal administration of micellar nanoparticle of Eucalyptus globulus on fore and hind limb of rats, possessed the central and peripheral analgesic effects by prolonged the rats pain responses towards the heat stimulus after being put on top of hot plate (55 °C), with longest time responses, 40.75 s at 60 min after treatment administration. Thus, this study demonstrated that micellar nanoparticle of Eucalyptus globulus formed in nanoemulsion system could be promising as an efficient transdermal nanocarrier for the analgesic therapy alternative.
    Matched MeSH terms: Hot Temperature
  5. Patterns of root respiration rates and morphological traits in 13 tree species in a tropical forest
    Makita N, Kosugi Y, Dannoura M, Takanashi S, Niiyama K, Kassim AR, et al.
    Tree Physiol, 2012 Mar;32(3):303-12.
    PMID: 22367761 DOI: 10.1093/treephys/tps008
    The root systems of forest trees are composed of different diameters and heterogeneous physiological traits. However, the pattern of root respiration rates from finer and coarser roots across various tropical species remains unknown. To clarify how respiration is related to the morphological traits of roots, we evaluated specific root respiration and its relationships to mean root diameter (D) of various diameter and root tissue density (RTD; root mass per unit root volume; gcm(-3)) and specific root length (SRL; root length per unit root mass; mg(-1)) of the fine roots among and within 14 trees of 13 species from a primary tropical rainforest in the Pasoh Forest Reserve in Peninsular Malaysia. Coarse root (2-269mm) respiration rates increased with decreasing D, resulting in significant relationships between root respiration and diameter across species. A model based on a radial gradient of respiration rates of coarse roots simulated the exponential decrease in respiration with diameter. The respiration rate of fine roots (<2mm) was much higher and more variable than those of larger diameter roots. For fine roots, the mean respiration rates for each species increased with decreasing D. The respiration rates of fine roots declined markedly with increasing RTD and increased with increasing SRL, which explained a significant portion of the variation in the respiration among the 14 trees from 13 species examined. Our results indicate that coarse root respiration in tree species follows a basic relationship with D across species and that most of the variation in fine root respiration among species is explained by D, RTD and SRL. We found that the relationship between root respiration and morphological traits provides a quantitative basis for separating fine roots from coarse roots and that the pattern holds across different species.
    Matched MeSH terms: Temperature
  6. Fulltext COSMO-RS Based Prediction for Alpha-Linolenic Acid (ALA) Extraction from Microalgae Biomass Using Room Temperature Ionic Liquids (RTILs)
    Rezaei Motlagh S, Harun R, Awang Biak DR, Hussain SA, Omar R, Elgharbawy AA
    Mar Drugs, 2020 Feb 12;18(2).
    PMID: 32059424 DOI: 10.3390/md18020108
    One of the essential fatty acids with therapeutic impacts on human health is known to be omega-3 polyunsaturated fatty acids (PUFA). More lately, ionic liquids (ILs) have received significant attention among scientists in overcoming the disadvantages of traditional solvents in biomass lipid extraction. However, the large pool of cations and anions possibly accessible will lead to a growing number of innovatively synthesized ILs. Nevertheless, the exhaustive measurement of all these systems is economically impractical. The conductive screening model for real solvents (COSMO-RS) is considered a precious approach with the availability of a few models to predict the characteristics of ILs. This work introduces the estimate of capacity values at infinite dilution for a range of ILs using COSMO-RS software as part of solid-liquid extraction. This favorable outcome presented that the capacity values of the IL molecules are extremely dependent on both anions and cations. Among the 352 combinations of cation/anion tested, short alkyl chain cations coupled with inorganic anions were found to be most efficient and therefore superior in the extraction method. Sulphate-, chloride-, and bromide-based ILs were found to have higher extraction capacities in contrast with the remainders, while propanoate revealed an extraordinary capacity when combined with ethyl-based cations. Eventually, the predicted results from COSMO-RS were validated through the experimentally calculated extraction yield of alpha-linolenic acid (ALA) compound from Nannochloropsis sp. microalgae. Three selected ILs namely [EMIM][Cl], [TMAm][Cl], and [EMPyrro][Br] were selected from COSMO-RS for empirical extraction purpose and the validation results pinpointed the good prediction capability of COSMO-RS.
    Matched MeSH terms: Temperature
  7. Fulltext Simultaneous Adsorption of Malachite Green and Methylene Blue Dyes in a Fixed-Bed Column Using Poly(Acrylonitrile-Co-Acrylic Acid) Modified with Thiourea
    Adeyi AA, Jamil SNAM, Abdullah LC, Choong TSY, Lau KL, Alias NH
    Molecules, 2020 Jun 07;25(11).
    PMID: 32517324 DOI: 10.3390/molecules25112650
    Proper remediation of aquatic environments contaminated by toxic organic dyes has become a research focus globally for environmental and chemical engineers. This study evaluates the adsorption potential of a polymer-based adsorbent, thiourea-modified poly(acrylonitrile-co-acrylic acid) (T-PAA) adsorbent, for the simultaneous uptake of malachite green (MG) and methylene blue (MB) dye ions from binary system in a continuous flow adsorption column. The influence of inlet dye concentrations, pH, flow rate, and adsorbent bed depth on adsorption process were investigated, and the breakthrough curves obtained experimentally. Results revealed that the sorption capacity of the T-PAA for MG and MB increase at high pH, concentration and bed-depth. Thomas, Bohart-Adams, and Yoon-Nelson models constants were calculated to describe MG and MB adsorption. It was found that the three dynamic models perfectly simulate the adsorption rate and behavior of cationic dyes entrapment. Finally, T-PAA adsorbent demonstrated good cyclic stability. It can be regenerated seven times (or cycles) with no significant loss in adsorption potential. Overall, the excellent sorption capacity and multiple usage make T-PAA polymer an attractive adsorbent materials for treatment of multicomponent dye bearing effluent in a fixed-bed column system.
    Matched MeSH terms: Temperature
  8. Fulltext Molecular Cloning and Functional Expression of a Δ9- Fatty Acid Desaturase from an Antarctic Pseudomonas sp. A3
    Garba L, Mohamad Ali MS, Oslan SN, Rahman RN
    PLoS One, 2016;11(8):e0160681.
    PMID: 27494717 DOI: 10.1371/journal.pone.0160681
    Fatty acid desaturase enzymes play an essential role in the synthesis of unsaturated fatty acids. Pseudomonas sp. A3 was found to produce a large amount of palmitoleic and oleic acids after incubation at low temperatures. Using polymerase Chain Reaction (PCR), a novel Δ9- fatty acid desaturase gene was isolated, cloned, and successfully expressed in Escherichia coli. The gene was designated as PA3FAD9 and has an open reading frame of 1,185 bp which codes for 394 amino acids with a predicted molecular weight of 45 kDa. The activity of the gene product was confirmed via GCMS, which showed a functional putative Δ9-fatty acid desaturase capable of increasing the total amount of cellular unsaturated fatty acids of the E. coli cells expressing the gene. The results demonstrate that the cellular palmitoleic acids have increased two-fold upon expression at 15°C using only 0.1 mM IPTG. Therefore, PA3FAD9 from Pseudomonas sp.A3 codes for a Δ9-fatty acid desaturase-like protein which was actively expressed in E. coli.
    Matched MeSH terms: Cold Temperature
  9. Fulltext Synthesis and characterization of modified κ-carrageenan for enhanced proton conductivity as polymer electrolyte membrane
    Liew JWY, Loh KS, Ahmad A, Lim KL, Wan Daud WR
    PLoS One, 2017;12(9):e0185313.
    PMID: 28957374 DOI: 10.1371/journal.pone.0185313
    Polymer electrolyte membranes based on the natural polymer κ-carrageenan were modified and characterized for application in electrochemical devices. In general, pure κ-carrageenan membranes show a low ionic conductivity. New membranes were developed by chemically modifying κ-carrageenan via phosphorylation to produce O-methylene phosphonic κ-carrageenan (OMPC), which showed enhanced membrane conductivity. The membranes were prepared by a solution casting method. The chemical structure of OMPC samples were characterized using Fourier transform infrared spectroscopy (FTIR), 1H nuclear magnetic resonance (1H NMR) spectroscopy and 31P nuclear magnetic resonance (31P NMR) spectroscopy. The conductivity properties of the membranes were investigated by electrochemical impedance spectroscopy (EIS). The characterization demonstrated that the membranes had been successfully produced. The ionic conductivity of κ-carrageenan and OMPC were 2.79 × 10-6 S cm-1 and 1.54 × 10-5 S cm-1, respectively. The hydrated membranes showed a two orders of magnitude higher ionic conductivity than the dried membranes.
    Matched MeSH terms: Temperature
  10. Fulltext A Review on Graphene-Based Light Emitting Functional Devices
    Junaid M, Md Khir MH, Witjaksono G, Ullah Z, Tansu N, Saheed MSM, et al.
    Molecules, 2020 Sep 14;25(18).
    PMID: 32937975 DOI: 10.3390/molecules25184217
    In recent years, the field of nanophotonics has progressively developed. However, constant demand for the development of new light source still exists at the nanometric scale. Light emissions from graphene-based active materials can provide a leading platform for the development of two dimensional (2-D), flexible, thin, and robust light-emitting sources. The exceptional structure of Dirac's electrons in graphene, massless fermions, and the linear dispersion relationship with ultra-wideband plasmon and tunable surface polarities allows numerous applications in optoelectronics and plasmonics. In this article, we present a comprehensive review of recent developments in graphene-based light-emitting devices. Light emissions from graphene-based devices have been evaluated with different aspects, such as thermal emission, electroluminescence, and plasmons assisted emission. Theoretical investigations, along with experimental demonstration in the development of graphene-based light-emitting devices, have also been reviewed and discussed. Moreover, the graphene-based light-emitting devices are also addressed from the perspective of future applications, such as optical modulators, optical interconnects, and optical sensing. Finally, this review provides a comprehensive discussion on current technological issues and challenges related to the potential applications of emerging graphene-based light-emitting devices.
    Matched MeSH terms: Temperature
  11. Fulltext Optimisation of preparation conditions for Ti nanowires and suitability as an antibacterial material
    Munisparan T, Yang ECY, Paramasivam R, Dahlan NA, Pushpamalar J
    IET Nanobiotechnol, 2018 Jun;12(4):429-435.
    PMID: 29768225 DOI: 10.1049/iet-nbt.2017.0186
    Ultrafine titanium dioxide (TiO2) nanowires were synthesised using a hydrothermal method with different volumes of ethylene glycol (EG) and annealing temperatures. It shows that sodium titanate nanowires synthesised using 5 and 10 ml EG, which annealed at 400°C produced TiO2 nanowires that correspond to a photochemically active phase, which is anatase. The influences of annealing temperatures (400-600°C) on the morphological arrangement of TiO2 nanowires were evident in the field emission scanning electron microscopy. The annealing temperature of 500°C led to agglomeration, which formed a mixture of TiO2 nanoparticles and nanowires. High thermal stability of TiO2 nanowires revealed by thermogravimetric analysis and Fourier transform infrared spectroscopy spectrum showed the presence of the Ti-O-Ti vibrations as evidenced due to TiO2 lattices. An antibacterial study using TiO2 nanowires toward Escherichia coli and Klebsiella pneumoniae showed large zones of inhibition that indicated susceptibility of the microbe toward TiO2. Growth kinetic analysis shows that addition of TiO2 has reduced optical density (OD) suggesting an inhibition of the growth of bacteria. These results indicate TiO2 nanowires can be effectively used as an antimicrobial agent against gram-bacteria. The TiO2 nanowires could be exploited in the medical, packaging and detergent formulation industries and wastewater treatment.
    Matched MeSH terms: Hot Temperature
  12. Effect of Gibberellin and Heat Shock on the Lipid Composition of Endoplasmic Reticulum in Barley Aleurone Layers
    Grindstaff KK, Fielding LA, Brodl MR
    Plant Physiol, 1996 Feb;110(2):571-581.
    PMID: 12226205
    The heat-shock responses of barley (Hordeum vulgare L. cv Hi- malaya) aleurone layers incubated with or without gibberellic acid (GA3) were compared. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that heat shock blocked the synthesis and secretion of secretory proteins from GA3-treated layers but not untreated layers. This suppression of secretory protein synthesis has been correlated with changes in endoplasmic reticulum (ER) membranes (F.C. Belanger, M. R. Brodl, T.-h.D. Ho [1986] Proc Natl Acad Sci USA 83: 1354-1358; L. Sticher, A.K. Biswas, D.S. Bush, R.L. Jones [1990] Plant Physiol 92: 506-513). Our secretion data suggested that the ER membranes of aleurone layers incubated without GA3 may be more heat shock tolerant. To investigate this, the lipid profiles of membrane extracts in aleurone layers labeled with [14C]glycerol were examined. Heat shock markedly increased [14C]glycerol incorporation into phosphatidylcholine (PC), and gas chromatography revealed an increase in the amount of saturated fatty acids associated with thin layer chromatography-purified PC in GA3-treated layers. In contrast, aleurone layers incubated without GA3 at normal temperature contained PC-associated fatty acids with a greater degree of saturation than GA3-treated layers. Heat shock modestly increased the degree of fatty acid saturation in untreated aleurone layers. This same trend was noted in fatty acids isolated from ER membranes purified by continuous sucrose density centrifugation. We propose that increased fatty acid saturation may help sustain ER membrane function in heat-shocked aleurone layers incubated in the absence of GA3.
    Matched MeSH terms: Temperature
  13. Fulltext Production of a solvent, detergent, and thermotolerant lipase by a newly isolated Acinetobacter sp. in submerged and solid-state fermentations
    Khoramnia A, Ebrahimpour A, Beh BK, Lai OM
    J Biomed Biotechnol, 2011;2011:702179.
    PMID: 21960739 DOI: 10.1155/2011/702179
    The lipase production ability of a newly isolated Acinetobacter sp. in submerged (SmF) and solid-state (SSF) fermentations was evaluated. The results demonstrated this strain as one of the rare bacterium, which is able to grow and produce lipase in SSF even more than SmF. Coconut oil cake as a cheap agroindustrial residue was employed as the solid substrate. The lipase production was optimized in both media using artificial neural network. Multilayer normal and full feed forward backpropagation networks were selected to build predictive models to optimize the culture parameters for lipase production in SmF and SSF systems, respectively. The produced models for both systems showed high predictive accuracy where the obtained conditions were close together. The produced enzyme was characterized as a thermotolerant lipase, although the organism was mesophile. The optimum temperature for the enzyme activity was 45°C where 63% of its activity remained at 70°C after 2 h. This lipase remained active after 24 h in a broad range of pH (6-11). The lipase demonstrated strong solvent and detergent tolerance potentials. Therefore, this inexpensive lipase production for such a potent and industrially valuable lipase is promising and of considerable commercial interest for biotechnological applications.
    Matched MeSH terms: Temperature
  14. Fulltext Production of chemoenzymatic catalyzed monoepoxide biolubricant: optimization and physicochemical characteristics
    Salimon J, Salih N, Abdullah BM
    J Biomed Biotechnol, 2012;2012:693848.
    PMID: 22346338 DOI: 10.1155/2012/693848
    Linoleic acid (LA) is converted to per-carboxylic acid catalyzed by an immobilized lipase from Candida antarctica (Novozym 435). This per-carboxylic acid is only intermediate and epoxidized itself in good yields and almost without consecutive reactions. Monoepoxide linoleic acid 9(12)-10(13)-monoepoxy 12(9)-octadecanoic acid (MEOA) was optimized using D-optimal design. At optimum conditions, higher yield% (82.14) and medium oxirane oxygen content (OOC) (4.91%) of MEOA were predicted at 15 μL of H(2)O(2), 120 mg of Novozym 435, and 7 h of reaction time. In order to develop better-quality biolubricants, pour point (PP), flash point (FP), viscosity index (VI), and oxidative stability (OT) were determined for LA and MEOA. The results showed that MEOA exhibited good low-temperature behavior with PP of -41(°)C. FP of MEOA increased to 128(°)C comparing with 115(°)C of LA. In a similar fashion, VI for LA was 224 generally several hundred centistokes (cSt) more viscous than MEOA 130.8. The ability of a substance to resist oxidative degradation is another important property for biolubricants. Therefore, LA and MEOA were screened to measure their OT which was observed at 189 and 168(°)C, respectively.
    Matched MeSH terms: Temperature
  15. Fulltext Molybdate reduction to molybdenum blue by an Antarctic bacterium
    Ahmad SA, Shukor MY, Shamaan NA, Mac Cormack WP, Syed MA
    Biomed Res Int, 2013;2013:871941.
    PMID: 24381945 DOI: 10.1155/2013/871941
    A molybdenum-reducing bacterium from Antarctica has been isolated. The bacterium converts sodium molybdate or Mo⁶⁺ to molybdenum blue (Mo-blue). Electron donors such as glucose, sucrose, fructose, and lactose supported molybdate reduction. Ammonium sulphate was the best nitrogen source for molybdate reduction. Optimal conditions for molybdate reduction were between 30 and 50 mM molybdate, between 15 and 20°C, and initial pH between 6.5 and 7.5. The Mo-blue produced had a unique absorption spectrum with a peak maximum at 865 nm and a shoulder at 710 nm. Respiratory inhibitors such as antimycin A, sodium azide, potassium cyanide, and rotenone failed to inhibit the reducing activity. The Mo-reducing enzyme was partially purified using ion exchange and gel filtration chromatography. The partially purified enzyme showed optimal pH and temperature for activity at 6.0 and 20°C, respectively. Metal ions such as cadmium, chromium, copper, silver, lead, and mercury caused more than 95% inhibition of the molybdenum-reducing activity at 0.1 mM. The isolate was tentatively identified as Pseudomonas sp. strain DRY1 based on partial 16s rDNA molecular phylogenetic assessment and the Biolog microbial identification system. The characteristics of this strain would make it very useful in bioremediation works in the polar and temperate countries.
    Matched MeSH terms: Temperature
  16. Fulltext Optimization of Cat's Whiskers Tea (Orthosiphon stamineus) Using Supercritical Carbon Dioxide and Selective Chemotherapeutic Potential against Prostate Cancer Cells
    Al-Suede FS, Khadeer Ahamed MB, Abdul Majid AS, Baharetha HM, Hassan LE, Kadir MO, et al.
    Evid Based Complement Alternat Med, 2014;2014:396016.
    PMID: 25276215 DOI: 10.1155/2014/396016
    Cat's whiskers (Orthosiphon stamineus) leaves extracts were prepared using supercritical CO2 (SC-CO2) with full factorial design to determine the optimum extraction parameters. Nine extracts were obtained by varying pressure, temperature, and time. The extracts were analysed using FTIR, UV-Vis, and GC-MS. Cytotoxicity of the extracts was evaluated on human (colorectal, breast, and prostate) cancer and normal fibroblast cells. Moderate pressure (31.1 MPa) and temperature (60°C) were recorded as optimum extraction conditions with high yield (1.74%) of the extract (B2) at 60 min extraction time. The optimized extract (B2) displayed selective cytotoxicity against prostate cancer (PC3) cells (IC50 28 µg/mL) and significant antioxidant activity (IC50 42.8 µg/mL). Elevated levels of caspases 3/7 and 9 in B2-treated PC3 cells suggest the induction of apoptosis through nuclear and mitochondrial pathways. Hoechst and rhodamine assays confirmed the nuclear condensation and disruption of mitochondrial membrane potential in the cells. B2 also demonstrated inhibitory effects on motility and colonies of PC3 cells at its subcytotoxic concentrations. It is noteworthy that B2 displayed negligible toxicity against the normal cells. Chemometric analysis revealed high content of essential oils, hydrocarbon, fatty acids, esters, and aromatic sesquiterpenes in B2. This study highlights the therapeutic potentials of SC-CO2 extract of cat's whiskers in targeting prostate carcinoma.
    Matched MeSH terms: Temperature
  17. Fulltext Cytotoxic Activity of Kenaf Seed Oils from Supercritical Carbon Dioxide Fluid Extraction towards Human Colorectal Cancer (HT29) Cell Lines
    Abd Ghafar SA, Ismail M, Saiful Yazan L, Fakurazi S, Ismail N, Chan KW, et al.
    Evid Based Complement Alternat Med, 2013;2013:549705.
    PMID: 23606884 DOI: 10.1155/2013/549705
    Kenaf (Hibiscus cannabinus) from the family Malvaceae, is a valuable fiber plant native to India and Africa and is currently planted as the fourth commercial crop in Malaysia. Kenaf seed oil contains alpha-linolenic acid, phytosterol such as β -sitosterol, vitamin E, and other antioxidants with chemopreventive properties. Kenaf seeds oil (KSO) was from supercritical carbon dioxide extraction fluid (SFE) at 9 different permutations of parameters based on range of pressures from 200 to 600 bars and temperature from 40 to 80°C. They were 200/40, 200/60, 200/80, 400/40, 400/60, 400/80, 600/40, 600/60, and 600/80. Extraction from 9 parameters of KSO-SFE was screened for cytotoxicity towards human colorectal cancer cell lines (HT29) and mouse embryonic fibroblast (NIH/3T3) cell lines using MTS assay. KSO-SFE at 600/40 showed the strongest cytotoxicity towards HT29 with IC50 of 200 µg/mL. The IC50 for NIH/3T3 was not detected even at highest concentration employed. Cell cycle analysis showed a significant increase in the accumulation of KSO-SFE-treated cells at sub-G1 phase, indicating the induction of apoptosis by KSO-SFE. Further apoptosis induction was confirmed by Annexin V/PI and AO/PI staining.
    Matched MeSH terms: Temperature
  18. Fulltext Distribution pattern of black fly (Diptera: Simuliidae) assemblages along an altitudinal gradient in Peninsular Malaysia
    Ya'cob Z, Takaoka H, Pramual P, Low VL, Sofian-Azirun M
    Parasit Vectors, 2016 Apr 19;9:219.
    PMID: 27094088 DOI: 10.1186/s13071-016-1492-7
    BACKGROUND: Preimaginal black flies (Diptera: Simuliidae) are important components of the stream ecosystem. However, there has been limited research undertaken on the vertical distribution of preimaginal black flies and their associated ecological factors. Stream conditions are generally variable along the altitudinal gradient. Therefore, we conducted an in-depth entomological survey to investigate the simuliid distribution pattern along an altitudinal gradient in Peninsular Malaysia.

    METHODS: A total of 432 collections were performed in this study (24 samplings at each of 18 fixed-streams at monthly intervals) from February 2012 to January 2014. Larvae and pupae attached on aquatic substrates such as grasses, leaves and stems, twigs, plant roots and rocks were collected by hand using fine forceps. Stream depth (m), width (m), velocity (m/s), water temperature (°C), acidity (pH), conductivity (mS/cm) and dissolved oxygen (mg/L) were measured at the time of each collection.

    RESULTS: A total of 35 black fly species were recorded in the present study. The most frequently collected species were Simulium tani (31.7%) and S. whartoni (21.5%), while the relatively common species were Simulium sp. (nr. feuerborni) (16.2%), S. decuplum (15.5%), S. angulistylum (14.8%), S. bishopi (13.2%) and S. izuae (11.8%). Total estimated species richness ranged between 39.8 and 41.3, which yielded more than 80% of sampling efficiency. Six simuliid species were distributed below 500 m, whereas eight species were distributed above 1400 m. Simulium sp. (nr. feuerborni) and S. asakoae were found from middle to high altitudes (711-1813 m). Simulium whartoni, S. brevipar and S. bishopi were distributed widely from low to high altitudes (159-1813 m). Regression analysis between species richness and PCs revealed that the species richness was significantly associated with wider, deeper and faster streams at low altitude, normal water temperature (23-25 °C), low conductivity, higher discharge, more canopy cover and riparian vegetation and with larger streambed particles (F = 20.8, df = 1, 422, P 

    Matched MeSH terms: Temperature
  19. Interfacial partitioning behaviour of bovine serum albumin in polymer-salt aqueous two-phase system
    Chow YH, Yap YJ, Anuar MS, Tejo BA, Ariff A, Show PL, et al.
    J Chromatogr B Analyt Technol Biomed Life Sci, 2013 Sep 1;934:71-8.
    PMID: 23911538 DOI: 10.1016/j.jchromb.2013.06.034
    A relationship is proposed for the interfacial partitioning of protein in poly(ethylene glycol) (PEG)-phosphate aqueous two-phase system (ATPS). The relationship relates the natural logarithm of interfacial partition coefficient, ln G to the PEG concentration difference between the top and bottom phases, Δ[PEG], with the equation ln G=AΔ[PEG]+B. Results showed that this relationship provides good fits to the partition of bovine serum albumin (BSA) in ATPS which is comprised of phosphate and PEG of four different molecular weight 1450g/mol, 2000g/mol, 3350g/mol and 4000g/mol, with the tie-line length (TLL) in the range of 44-60% (w/w) at pH 7.0. The decrease of A values with the increase of PEG molecular weight indicates that the correlation between ln G and Δ[PEG] decreases with the increase in PEG molecular weight and the presence of protein-polymer hydrophobic interaction. When temperature was increased, a non-linear relationship of ln G inversely proportional to temperature was observed. The amount of proteins adsorbed at the interface increased proportionally with the amount of BSA loaded whereas the partition coefficient, K remained relatively constant. The relationship proposed could be applied to elucidate interfacial partitioning behaviour of other biomolecules in polymer-salt ATPS.
    Matched MeSH terms: Temperature
  20. Anti-phospholipid antibody isotypes in normal human sera
    Cheng HM, Wong KK
    Immunol Lett, 1990 Jan;23(3):183-6.
    PMID: 2307490
    Heat-sensitive serum masking cofactor(s) of antiphospholipid antibody (aPL) in normal human sera (NHS) are specifically inactivated at 56 degrees C. The degree of binding in ELISA by unmasked aPL in NHS was equivalent to that in non-heated, aPL-reactive autoimmune SLE sera. Previously "negative" SLE sera also reacted equally strongly in the aPL ELISA when similarly heat-inactivated. Isotype studies by ELISA of the heat-potentiated aPL in 36 NHS revealed the presence of specific IgG (34/36), IgM (11/36) and IgA (24/36) aPL antibodies. 11/36 (31%) NHS had all three aPL isotypes while 13/36 (36%) had both IgG and IgA antibodies to phospholipid.
    Matched MeSH terms: Hot Temperature
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links