Displaying publications 61 - 80 of 2911 in total

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  1. Zakaria ZA, Safarul M, Valsala R, Sulaiman MR, Fatimah CA, Somchit MN, et al.
    Naunyn Schmiedebergs Arch Pharmacol, 2005 Jul;372(1):55-62.
    PMID: 16133487
    A series of preliminary studies was carried out to evaluate the antinociceptive (pain relief) activity of the aqueous extract of Corchorus olitorius L. leaves (COAE) and to determine the influence of temperature and opioid receptors on COAE activity using the abdominal constriction and hot plate tests in mice. COAE, at concentrations of 10, 25, 50, 75, and 100%, showed both peripheral and central antinociception that are non-concentration- and concentration-dependent respectively. The peripheral activity was clearly observed at a concentration of 25% and diminished at a concentration of 100%, while the central activity was observed at all the concentrations of COAE used. Furthermore, the insignificant results obtained indicated that this peripheral activity (at concentrations of 25 and 50%) was comparable to that of morphine (0.8 mg/kg). Pre-heating COAE at a temperature of 80 degrees C and 100 degrees C, or 60 degrees C and 80 degrees C was found to enhance its peripheral and central antinociception respectively. Pre-treatment with naloxone (10 mg/kg), a general opioid receptor antagonist, for 5 min, followed by COAE, was found to completely block its peripheral, but not central, antinociceptive activity. Based on this observation, we conclude that the antinociceptive activity exhibited by C. olitorius is enhanced by the increase in temperature and may be mediated peripherally, but not centrally, at least in part, via an opioid receptor.
    Matched MeSH terms: Temperature
  2. Zakaria SM, Sharif Zein SH, Othman MR, Jansen JA
    J Biomed Mater Res A, 2013 Jul;101(7):1977-85.
    PMID: 23225849 DOI: 10.1002/jbm.a.34506
    Electrospinning of hydroxyapatite (HA)/polyvinyl butyral solution resulted in the formation of fibers with average diameter of 937-1440 nm. These fibers were converted into HA nanoparticles with size <100 nm after undergoing calcination treatment at 600°C. The diameter of the fiber was found to be influenced by applied voltage and spinning distance. The injection flowrate did not affect the diameter significantly. The electrospinning method successfully reduced the commercial HA particle size in the range of 400-1100 nm into <100 nm. The dispersion of the finally calcined HA nanoparticles was improved significantly after anionic sodium dodecyl sulfate surfactant was introduced. The experimental data of HA growth kinetics were subjected to the integral method of analysis, and the rate law of the reaction was found to follow the first order reaction.
    Matched MeSH terms: Hot Temperature
  3. Zakaria MR, Norrrahim MN, Hirata S, Hassan MA
    Bioresour Technol, 2015 Apr;181:263-9.
    PMID: 25659104 DOI: 10.1016/j.biortech.2015.01.072
    Eco-friendly pretreatment methods for lignocellulosic biomass are being developed as alternatives to chemical based methods. Superheated steam (SHS), hot compressed water (HCW) and wet disk milling (WDM) were used individually and with combination to partially remove hemicellulose and alter the lignin composition of recalcitrant structure of oil palm mesocarp fiber (OPMF). The efficiency of the pretreatment methods was evaluated based on the chemical compositions altered, SEM analysis, power consumption and degree of enzymatic digestibility. Hemicellulose removal (94.8%) was more pronounced under HCW compared to SHS, due to maximal contact of water and production of acetic acid which enhanced further degradation of hemicellulose. Subsequent treatment with WDM resulted in defibrillation of OPMF and expansion of the specific surface area thus increasing the conversion of cellulose to glucose. The highest glucose yield was 98.1% (g/g-substrate) when pretreated with HCW (200 °C, 20 min) and WDM which only consumed 9.6 MJ/kg of OPMF.
    Matched MeSH terms: Temperature*
  4. Zakaria MR, Hirata S, Hassan MA
    Bioresour Technol, 2015 Jan;176:142-8.
    PMID: 25460995 DOI: 10.1016/j.biortech.2014.11.027
    The present works investigate hydrothermal pretreatment of oil palm empty fruit bunch and oil palm frond fiber in a batch tube reactor system with temperature and time range from 170 to 250°C and 10 to 20min, respectively. The behavior of soluble sugars, acids, furans, and phenols dramatically changed over treatment severities as determined by HPLC. The cellulose-rich treated solids were analyzed by SEM, WAXD, and BET surface area. Enzymatic hydrolysis was performed from both pretreated slurries and washed solid, and data obtained suggested that tannic acid derived from lignin degradation was a potential cellulase inhibitor. Both partial removal of hemicellulose and migration of lignin during hydrothermal pretreatment caused structural changes on the cellulose-hemicellulose-lignin matrix, resulting in the opening and expansion of specific surface area and pore volume. The current results provided important factors that maximize conversion of cellulose to glucose from oil palm biomass by hydrothermal process.
    Matched MeSH terms: Hot Temperature*
  5. Zakaria MR, Hirata S, Hassan MA
    Bioresour Technol, 2014 Oct;169:236-43.
    PMID: 25058299 DOI: 10.1016/j.biortech.2014.06.095
    Hydrothermal pretreatment of oil palm mesocarp fiber was conducted in tube reactor at treatment severity ranges of log Ro = 3.66-4.83 and partial removal of hemicellulose with migration of lignin was obtained. Concerning maximal recovery of glucose and xylose, 1.5% NaOH was impregnated in the system and subsequent ball milling treatment was employed to improve the conversion yield. The effects of combined hydrothermal and ball milling pretreatments were evaluated by chemical composition changes by using FT-IR, WAXD and morphological alterations by SEM. The successful of pretreatments were assessed by the degree of enzymatic digestibility of treated samples. The highest xylose and glucose yields obtained were 63.2% and 97.3% respectively at cellulase loadings of 10 FPU/g-substrate which is the highest conversion from OPMF ever reported.
    Matched MeSH terms: Temperature*
  6. Zakaria MR, Hirata S, Fujimoto S, Hassan MA
    Bioresour Technol, 2015 Oct;193:128-34.
    PMID: 26125612 DOI: 10.1016/j.biortech.2015.06.074
    Combined pretreatment with hot compressed water and wet disk milling was performed with the aim to reduce the natural recalcitrance of oil palm biomass by opening its structure and provide maximal access to cellulase attack. Oil palm empty fruit bunch and oil palm frond fiber were first hydrothermally pretreated at 150-190° C and 10-240 min. Further treatment with wet disk milling resulted in nanofibrillation of fiber which caused the loosening of the tight biomass structure, thus increasing the subsequent enzymatic conversion of cellulose to glucose. The effectiveness of the combined pretreatments was evaluated by chemical composition changes, power consumption, morphological alterations by SEM and the enzymatic digestibility of treated samples. At optimal pretreatment process, approximately 88.5% and 100.0% of total sugar yields were obtained from oil palm empty fruit bunch and oil palm frond fiber samples, which only consumed about 15.1 and 23.5 MJ/kg of biomass, respectively.
    Matched MeSH terms: Hot Temperature
  7. Zak AK, Razali R, Majid WH, Darroudi M
    Int J Nanomedicine, 2011;6:1399-403.
    PMID: 21796242 DOI: 10.2147/IJN.S19693
    Zinc oxide nanoparticles (ZnO-NPs) were synthesized via a solvothermal method in triethanolamine (TEA) media. TEA was utilized as a polymer agent to terminate the growth of ZnO-NPs. The ZnO-NPs were characterized by a number of techniques, including X-ray diffraction analysis, transition electron microscopy, and field emission electron microscopy. The ZnO-NPs prepared by the solvothermal process at 150°C for 18 hours exhibited a hexagonal (wurtzite) structure, with a crystalline size of 33 ± 2 nm, and particle size of 48 ± 7 nm. The results confirm that TEA is a suitable polymer agent to prepare homogenous ZnO-NPs.
    Matched MeSH terms: Hot Temperature
  8. Zainudin, M.F., Hussin, H., Halim, A.K.
    MyJurnal
    Negative bias temperature instability (NBTI) is the most concern issue CMOS devices with the scaling
    down of the CMOS technologies. NBTI effect contributes to P-MOSFET device degradation which later
    reduce the performance and reliability of CMOS circuits. This paper presents a reliability simulation study
    based on R-D model on CMOS inverter circuit. HSPICE MOSRA model together with the Predictive
    Technology Model (PTM) was used as to incorporate the NBTI model in the circuit reliability simulation
    study for different technology nodes. PTM of High Performance (HP) models of 16nm, 22nm, 32nm
    and 45nm were used in this simulation study. The atomic hydrogen based model was integrated in the
    simulation. The results show that in a CMOS inverter circuit, the threshold voltage shift of p-MOSFET
    under NBTI stressing increased as the year progressed.. The threshold voltage shift was observed to
    increase up to 45.1% after 10 years of operation. The time exponent, n ~ 0.232 of the threshold voltage
    shift observed indicates that the defect mechanism contributed to the degradation is atomic hydrogen.
    The propagation delay increased to 19.5% over a 10-year period. s up to 19.5% from the zero year
    of operation until 10 years of the operation. In addition, the time propagation delay increased as year
    increased when the technology nodes smaller. The finding is important for understanding reliability
    issues related to advanced technology nodes in CMOS circuits study.
    Matched MeSH terms: Temperature
  9. Zainudin MHM, Mustapha NA, Hassan MA, Bahrin EK, Tokura M, Yasueda H, et al.
    Sci Rep, 2019 09 19;9(1):13526.
    PMID: 31537863 DOI: 10.1038/s41598-019-50126-y
    A thermophilic Thermobifida fusca strain UPMC 901, harboring highly thermostable cellulolytic activity, was successfully isolated from oil palm empty fruit bunch compost. Its endoglucanase had the highest activity at 24 hours of incubation in carboxymethyl-cellulose (CMC) and filter paper. A maximum endoglucanase activity of 0.9 U/mL was achieved at pH 5 and 60 °C using CMC as a carbon source. The endoglucanase properties were further characterized using crude enzyme preparations from the culture supernatant. Thermal stability indicated that the endoglucanase activity was highly stable at 70 °C for 24 hours. Furthermore, the activity was found to be completely maintained without any loss at 50 °C and 60 °C for 144 hours, making it the most stable than other endoglucanases reported in the literature. The high stability of the endoglucanase at an elevated temperature for a prolonged period of time makes it a suitable candidate for the biorefinery application.
    Matched MeSH terms: Temperature
  10. Zainuddin ZZ, Mohamed Tarmizi MR, Yap KC, Comizzoli P, Sipangkui S
    Animals (Basel), 2020 06 22;10(6).
    PMID: 32580372 DOI: 10.3390/ani10061072
    A better understanding of semen characteristics and resilience to freezing temperatures is necessary before developing assisted reproductive techniques and systematic biobanking for the Sunda clouded leopard. The objective of this study was to evaluate for the first time the semen and sperm quality (in fresh and frozen samples) of two captive Sunda clouded leopards in Malaysia. A total of 17 examinations of the reproductive tract (using ultrasonography) and electro-ejaculations were performed on the two leopards over a 2-year period. Samples obtained from Leopard 1 (8 years old) varied in terms of volume (402 ± 92 µL), pH (7.9 ± 0.9), sperm motility (54.5 ± 24.2%), sperm concentration (122.4 ± 84.7 × 106 sperm/mL), normal morphology (23.9 ± 12.3%), and viability (55.2 ± 18.2%). Midpiece defects represented the most common structural abnormality followed by abnormal tail and head defects. Samples from Leopard 2 (11 year old with abnormal testicular tissue) were of lesser quality. Two frozen semen samples from Leopard 1 were thawed and examined for acrosome integrity. Post-thawed samples contained <10% of motile spermatozoa but almost 50% of abnormal acrosomes. The present results emphasized the high incidence of structurally-abnormal spermatozoa, similar to the mainland clouded leopard. Post-thaw evaluations showed that the few surviving spermatozoa could potentially be used for in vitro fertilization or sperm injection. However, more individuals must be studied to validate those first findings that are exciting but still preliminary.
    Matched MeSH terms: Temperature
  11. Zainuddin Z, Wan Daud WR, Pauline O, Shafie A
    Bioresour Technol, 2011 Dec;102(23):10978-86.
    PMID: 21996481 DOI: 10.1016/j.biortech.2011.09.080
    In the organosolv pulping of the oil palm fronds, the influence of the operational variables of the pulping reactor (viz. cooking temperature and time, ethanol and NaOH concentration) on the properties of the resulting pulp (yield and kappa number) and paper sheets (tensile index and tear index) was investigated using a wavelet neural network model. The experimental results with error less than 0.0965 (in terms of MSE) were produced, and were then compared with those obtained from the response surface methodology. Performance assessment indicated that the neural network model possessed superior predictive ability than the polynomial model, since a very close agreement between the experimental and the predicted values was obtained.
    Matched MeSH terms: Temperature
  12. Zainuddin SY, Ahmad I, Kargarzadeh H, Abdullah I, Dufresne A
    Carbohydr Polym, 2013 Feb 15;92(2):2299-305.
    PMID: 23399291 DOI: 10.1016/j.carbpol.2012.11.106
    Biodegradable materials made from cassava starch and kenaf fibers were prepared using a solution casting method. Kenaf fibers were treated with NaOH, bleached with sodium chlorite and acetic buffer solution, and subsequently acid hydrolyzed to obtain cellulose nanocrystals (CNCs). Biocomposites in the form of films were prepared by mixing starch and glycerol/sorbitol with various filler compositions (0-10 wt%). X-ray diffraction revealed that fiber crystallinity increased after each stage of treatment. Morphological observations and size reductions of the extracted cellulose and CNCs were studied using field emission scanning electron microscopy and transmission electron microscopy. The effects of different treatments and filler contents of the biocomposites were evaluated through mechanical tests. Results showed that the tensile strengths and moduli of the biocomposites increased after each treatment and the optimum filler content was 6%.
    Matched MeSH terms: Temperature
  13. Zainuddin N, Saleh H, Hashim I, Roslan R
    Sains Malaysiana, 2016;45:315-321.
    Effects of radiation on free convection about a heated horizontal circular cylinder in the presence of heat generation is investigated numerically. The cylinder is fixed and immersed in a stationary fluid, in which the temperature is uniformly heated about the temperature of the surrounding fluid. The governing equations are transformed into dimensionless non-linear partial differential equations and solved by employing a finite difference method. An implicit finite difference scheme of Crank Nicolson method is used to analyze the results. This study determined the effects of radiation parameter, heat generation parameter, and the Prandtl number, on the temperature and velocity profiles. The results of the local heat transfer and skin-friction coefficient in the presence of radiation for some selected values of and are shown graphically.
    Matched MeSH terms: Body Temperature Regulation; Hot Temperature; Temperature
  14. Zainon SNM, Azmi WH
    Micromachines (Basel), 2021 Feb 11;12(2).
    PMID: 33670250 DOI: 10.3390/mi12020176
    Many studies have shown the remarkable enhancement of thermo-physical properties with the addition of a small quantity of nanoparticles into conventional fluids. However, the long-term stability of the nanofluids, which plays a significant role in enhancing these properties, is hard to achieve, thus limiting the performance of the heat transfer fluids in practical applications. The present paper attempts to highlight various approaches used by researchers in improving and evaluating the stability of thermal fluids and thoroughly explores various factors that contribute to the enhancement of the thermo-physical properties of mono, hybrid, and green nanofluids. There are various methods to maintain the stability of nanofluids, but this paper particularly focuses on the sonication process, pH modification, and the use of surfactant. In addition, the common techniques to evaluate the stability of nanofluids are undertaken by using visual observation, TEM, FESEM, XRD, zeta potential analysis, and UV-Vis spectroscopy. Prior investigations revealed that the type of nanoparticle, particle volume concentration, size and shape of particles, temperature, and base fluids highly influence the thermo-physical properties of nanofluids. In conclusion, this paper summarized the findings and strategies to enhance the stability and factors affecting the thermal conductivity and dynamic viscosity of mono and hybrid of nanofluids towards green nanofluids.
    Matched MeSH terms: Hot Temperature; Temperature
  15. Zainol Z, Akhir MF, Johari A, Ali A
    Data Brief, 2021 Apr;35:106866.
    PMID: 33816725 DOI: 10.1016/j.dib.2021.106866
    This article contains water quality data collected in a shallow and narrow Setiu Lagoon during the southwest monsoon, wet period of northeast monsoon and dry period of northeast monsoon. The surface water quality parameters, which include the temperature, salinity, chlorophyll-a and nutrients (ammonia, nitrate, phosphate, and silicate) were sampled twice per day (high and low tides) at a total of eight stations. Hourly current speed and direction was obtained from mooring of two units of current meters. Compared to the Malaysia Marine Water Quality Criteria and Standard (MWQCS), nutrients in Setiu Lagoon were in Class 2. Although limited, this dataset can provide insights on the changes of water quality condition in Setiu Lagoon under the presence of anthropogenic pressures.
    Matched MeSH terms: Temperature
  16. Zainol NA, Ming TS, Darwis Y
    Indian J Pharm Sci, 2015 12 15;77(4):422-33.
    PMID: 26664058 DOI: 10.4103/0250-474x.164785
    Cinnamon leaf oil contains a high percentage of eugenol and has antimicrobial, antioxidant and antiinflammatory properties. However, the undiluted oil can cause irritation to the skin. Therefore, the aims of this study were to develop and evaluate cinnamon leaf oil nanocream using palm oil. Nanocream base was prepared using different ratios of oil, surfactants and water. The surfactant used were mixture of Tween 80:Carbitol or Tween 80:Span 65 at different hydrophile-lipophile balance values. The pseudoternary phase diagrams were constructed to identify the nanocream base areas and the results showed that the nanocream bases using Span 65 as co-surfactant produced bigger cream area. Fifteen formulations using mixtures of Tween 80:Span 65 were further evaluated for accelerated stability test, droplet size, zeta potential, rheological properties and apparent viscosity. The nanocream base which had an average droplet size of 219 nm and had plastic flow with thixotropic behavior was selected for incorporation of 2% cinnamon leaf oil. The nanocream containing cinnamon leaf oil had the average size of 286 nm and good rheological characteristics. The in vitro release study demonstrated that eugenol as the main constituent of cinnamon leaf oil was released for about 81% in 10 h. The short-term stability study conducted for 6 months showed that the cinnamon leaf oil nanocream was stable at a temperature of 25° and thus, cinnamon leaf oil nanocream is a promising natural based preparation to be used for topical application.
    Matched MeSH terms: Temperature
  17. Zaini NA, Osman A, Hamid AA, Ebrahimpour A, Saari N
    Food Chem, 2013 Jan 15;136(2):407-14.
    PMID: 23122078 DOI: 10.1016/j.foodchem.2012.08.034
    Membrane-bound polyphenoloxidase (mPPO) an oxidative enzyme which is responsible for the undesirable browning reaction in Snake fruit (Salacca zalacca (Gaertn.) Voss) was investigated. The enzyme was extracted using a non-ionic detergent (Triton X-114), followed by temperature-induced phase partitioning technique which resulted in two separate layers (detergent-poor phase at the upper layer and detergent-rich phase at the lower layer). The upper detergent-poor phase extract was subsequently fractionated by 40-80% ammonium sulfate and chromatographed on HiTrap Phenyl Sepharose and Superdex 200 HR 10/30. The mPPO was purified to 14.1 folds with a recovery of 12.35%. A single prominent protein band appeared on native-PAGE and SDS-PAGE implying that the mPPO is a monomeric protein with estimated molecular weight of 38kDa. Characterization study showed that mPPO from Snake fruit was optimally active at pH 6.5, temperature 30°C and active towards diphenols as substrates. The K(m) and V(max) values were calculated to be 5.46 mM and 0.98 U/ml/min, respectively, when catechol was used as substrate. Among the chemical inhibitors tested, l-cysteine showed the best inhibitory effect, with an IC(50) of 1.3 ± 0.002 mM followed by ascorbic acid (1.5 ± 0.06 mM), glutathione (1.5 ± 0.07 mM), EDTA (100 ± 0.02 mM) and citric acid (186 ± 0.16 mM).
    Matched MeSH terms: Temperature
  18. Zaini MS, Liew JYC, Alang Ahmad SA, Mohmad AR, Ahmad Kamarudin M
    ACS Omega, 2020 Dec 08;5(48):30956-30962.
    PMID: 33324803 DOI: 10.1021/acsomega.0c03768
    The existence of surface organic capping ligands on quantum dots (QDs) has limited the potential in QDs emission properties and energy band gap structure alteration as well as the carrier localization. This drawback can be addressed via depositing a thin layer of a semiconductor material on the surface of QDs. Herein, we report on the comparative study for photoluminescent (PL) properties of PbS and PbS/MnS QDs. The carrier localization effect due to the alteration of energy band gap structure and carrier recombination mechanism in the QDs were investigated via PL measurements in a temperature range of 10-300 K with the variation of the excitation power from 10 to 200 mW. For PbS QDs, the gradient of integrated PL intensity (IPL) as a function of excitation power density graph was less than unity. When the MnS shell layer was deposited onto the PbS core, the PL emission exhibited a blue shift, showing dominant carrier recombination. It was also found that the full width half-maximum showed a gradual broadening with the increasing temperature, affirming the electron-phonon interaction.
    Matched MeSH terms: Temperature
  19. Zainazlan Md Zain1, Mohd Nasir Taib, Shahrizam M. S. Baki, Azni Zain Ahmed
    MyJurnal
    This paper examines the temperature profile of a building material and also a
    built space. The study directly examines the influence of solar radiation on
    building material and the heat it generated and diffuses into the built space.
    Two experiments are presented. The first look at a simple technique for
    evaluating heat performance of a building material, and the second evaluates
    the performance of a cross-ventilated built space with respect to solar radiation.
    Matched MeSH terms: Hot Temperature; Temperature
  20. Zainal N, Mohamed N, Idris R
    Sains Malaysiana, 2013;42:481-485.
    In this work, epoxidized natural rubber 50 (ENR-50) has been used as a host polymer for the preparation of electrolyte system. Attenuated total reflection-fourier transform infrared spectroscopic analyses showed the presence of lithium saltENR interactions. The glass transition temperature displayed an increasing trend with the increase in salt concentration indicating that the ionic conductivity was not influenced by segmental motion of the ENR-50 chains. The increase in
    glass transition temperature with the addition of salt was due to the formation of transient cross-linking between ENR-50 chains via the coordinated interaction between ENR-50 chains and salt. The highest room temperature ionic conductivity obtained was in the order of 10-5 S cm-1 for the film containing 50 wt% of lithium salt. The ionic conductivity of this electrolyte system increased with increasing temperature and obeyed the Vogel-Tamman-Fulcher behavior. The increase in ionic conductivity of the electrolyte system with salt concentration could also be correlated to the charge carriers concentration and/or migration rate of charge carriers.
    Matched MeSH terms: Temperature; Transition Temperature
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