Displaying publications 1 - 20 of 248 in total

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  1. Vinazzer H
    Wien Z Inn Med, 1971;52(8):378-92.
    PMID: 5110844
    Matched MeSH terms: Blood Viscosity/drug effects
  2. Ho YC, Norli I, Alkarkhi AF, Morad N
    Water Sci Technol, 2009;60(3):771-81.
    PMID: 19657173 DOI: 10.2166/wst.2009.303
    The performance of pectin in turbidity reduction and the optimum condition were determined using Response Surface Methodology (RSM). The effect of pH, cation's concentration, and pectin's dosage on flocculating activity and turbidity reduction was investigated at three levels and optimized by using Box-Behnken Design (BBD). Coagulation and flocculation process were assessed with a standard jar test procedure with rapid and slow mixing of a kaolin suspension (aluminium silicate), at 150 rpm and 30 rpm, respectively, in which a cation e.g. Al(3+), acts as coagulant, and pectin acts as the flocculant. In this research, all factors exhibited significant effect on flocculating activity and turbidity reduction. The experimental data and model predictions well agreed. From the 3D response surface graph, maximum flocculating activity and turbidity reduction are in the region of pH greater than 3, cation concentration greater than 0.5 mM, and pectin dosage greater than 20 mg/L, using synthetic turbid wastewater within the range. The flocculating activity for pectin and turbidity reduction in wastewater is at 99%.
    Matched MeSH terms: Viscosity
  3. Krishnan S, Abd Ghani N, Aminuddin NF, Quraishi KS, Razafindramangarafara BL, Baup S, et al.
    Ultrason Sonochem, 2021 Jun;74:105576.
    PMID: 33975186 DOI: 10.1016/j.ultsonch.2021.105576
    This study investigates the potential of using small amounts of ionic liquids (IL) to enhance ultrasound-assisted extraction of lipids content from green microalgae. Three imidazolium-based ILs (butyl, octyl and dodecyl), each of them with two anions (bromide and acetate) were tested as additives. Viscosity and surface tension of the ILs aqueous mixtures were analyzed to determine the influence of ILs' anions and alkyl chain length, whereas KI dosimetry experiments were used as an indicator of radicals formation. A key finding suggests that the small addition of ILs improves the ultrasonication either by enhancing the viscosity and reducing the water surface tension, leading to a more powerful acoustic cavitation process or by increasing HO° production likely to oxidize the microalgae cells membranes, and consequently disrupting them on a more efficient manner. KI dosimetry also revealed that long ILs alkyl chain is detrimental. This experimental observation is confirmed thus strengthened as the yield of extracted lipids from green microalgae has shown an incremental trend when the IL concentration also increased. These hypotheses are currently under investigation to spot detailed impact of ILs on cavitation process.
    Matched MeSH terms: Viscosity
  4. Lim WTH, Ooi EH, Foo JJ, Ng KH, Wong JHD, Leong SS
    Ultrasonics, 2023 Aug;133:107046.
    PMID: 37247461 DOI: 10.1016/j.ultras.2023.107046
    The application of ultrasound shear wave elastography for detecting chronic kidney disease, namely renal fibrosis, has been widely studied. A good correlation between tissue Young's modulus and the degree of renal impairment has been established. However, the current limitation of this imaging modality pertains to the linear elastic assumption used in quantifying the stiffness of renal tissue in commercial shear wave elastography systems. As such, when underlying medical conditions such as acquired cystic kidney disease, which may potentially influence the viscous component of renal tissue, is present concurrently with renal fibrosis, the accuracy of the imaging modality in detecting chronic kidney disease may be affected. The findings in this study demonstrate that quantifying the stiffness of linear viscoelastic tissue using an approach similar to those implemented in commercial shear wave elastography systems led to percentage errors as high as 87%. The findings presented indicate that use of shear viscosity to detect changes in renal impairment led to a reduction in percentage error to values as low as 0.3%. For cases in which renal tissue was affected by multiple medical conditions, shear viscosity was found to be a good indicator in gauging the reliability of the Young's modulus (quantified through a shear wave dispersion analysis) in detecting chronic kidney disease. The findings show that percentage error in stiffness quantification can be reduced to as low as 0.6%. The present study demonstrates the potential use of renal shear viscosity as a biomarker to improve the detection of chronic kidney disease.
    Matched MeSH terms: Viscosity
  5. Phan TN, Lan NT, Nga NT
    Med J Malaysia, 2004 May;59 Suppl B:214-5.
    PMID: 15468894
    Natural rubber from hevea brasiliensis trees (Thailand, RRIM 600 clone) of different age (8, 20, and 35 years) were characterized by size exclusion chromatography coupled with online viscometry according to their distribution of molar mass and branching index at a temperature of 70 degrees C using cyclohexane as solvent. Washing with an aqueous solution of sodium dodecylsulfate and subsequent saponification purified the natural rubber samples. With this procedure physical branching points caused by phospholipids, proteins and hydrophobic terminal units, mainly fatty acids, of the natural rubber (cis-1,4-polyisoprene) molecule, could be removed leading to completely soluble polymer samples. All samples investigated possess a very broad (10 to 50,000 kg/mol) and distinct bimodal molar mass distribution. With increasing age the peak area in the low molar mass region decreases favoring the peak area in the high molar mass region. By plotting the branching index as a function of the both, the molar mass and the age of the trees.
    Matched MeSH terms: Viscosity
  6. Ishak R, Hassan K
    Med J Malaysia, 1985 Sep;40(3):191-5.
    PMID: 3842714
    Matched MeSH terms: Blood Viscosity*
  7. Tan SF, Kirby BP, Stanslas J, Basri HB
    J Pharm Pharmacol, 2017 Nov;69(11):1447-1457.
    PMID: 28809443 DOI: 10.1111/jphp.12800
    OBJECTIVE: This study was aimed to investigate the potential of formulated valproic acid-encapsulated nanoemulsion (VANE) to improve the brain bioavailability of valproic acid (VPA).

    METHODS: Valproic acid-encapsulated nanoemulsions were formulated and physically characterised (osmolarity, viscosity, drug content, drug encapsulation efficiency). Further investigations were also conducted to estimate the drug release, cytotoxic profile, in-vitro blood-brain barrier (BBB) permeability, pharmacokinetic parameter and the concentration of VPA and VANE in blood and brain.

    KEY FINDINGS: Physical characterisation confirmed that VANE was suitable for parenteral administration. Formulating VPA into nanoemulsion significantly reduced the cytotoxicity of VPA. In-vitro drug permeation suggested that VANEs crossed the BBB as freely as VPA. Pharmacokinetic parameters of VANE-treated rats in plasma and brain showed F3 VANE had a remarkable improvement in AUC, prolongation of half-life and reduction in clearance compared to VPA. Given the same extent of in-vitro BBB permeation of VPA and VANE, the higher bioavailability of VANE in brain was believed to have due to higher concentration of VANE in blood. The brain bioavailability of VPA was improved by prolonging the half-life of VPA by encapsulating it within the nanoemulsion-T80.

    CONCLUSIONS: Nanoemulsion containing VPA has alleviated the cytotoxic effect of VPA and improved the plasma and brain bioavailability for parenteral delivery of VPA.

    Matched MeSH terms: Viscosity
  8. Vinazzer H
    Subsid Med, 1974;4:53-5.
    PMID: 4450561
    Matched MeSH terms: Blood Viscosity/drug effects
  9. Ali AQ, Teoh SG, Salhin A, Eltayeb NE, Khadeer Ahamed MB, Abdul Majid AM
    PMID: 24607427 DOI: 10.1016/j.saa.2014.01.086
    New derivatives of thiosemicarbazone Schiff base with isatin moiety were synthesized L1-L6. The structures of these compounds were characterized based on the spectroscopic techniques. Compound L6 was further characterized by XRD single crystal. The interaction of these compounds with calf thymus (CT-DNA) exhibited high intrinsic binding constant (k(b)=5.03-33.00×10(5) M(-1)) for L1-L3 and L5 and (6.14-9.47×10(4) M(-1)) for L4 and L6 which reflect intercalative activity of these compounds toward CT-DNA. This result was also confirmed by the viscosity data. The electrophoresis studies reveal the higher cleavage activity of L1-L3 than L4-L6. The in vitro anti-proliferative activity of these compounds against human colon cancer cell line (HCT 116) revealed that the synthesized compounds (L3, L6 and L2) exhibited good anticancer potency.
    Matched MeSH terms: Viscosity/drug effects
  10. Abdollahi Y, Sairi NA, Said SB, Abouzari-lotf E, Zakaria A, Sabri MF, et al.
    PMID: 26119355 DOI: 10.1016/j.saa.2015.06.036
    It is believe that 80% industrial of carbon dioxide can be controlled by separation and storage technologies which use the blended ionic liquids absorber. Among the blended absorbers, the mixture of water, N-methyldiethanolamine (MDEA) and guanidinium trifluoromethane sulfonate (gua) has presented the superior stripping qualities. However, the blended solution has illustrated high viscosity that affects the cost of separation process. In this work, the blended fabrication was scheduled with is the process arranging, controlling and optimizing. Therefore, the blend's components and operating temperature were modeled and optimized as input effective variables to minimize its viscosity as the final output by using back-propagation artificial neural network (ANN). The modeling was carried out by four mathematical algorithms with individual experimental design to obtain the optimum topology using root mean squared error (RMSE), R-squared (R(2)) and absolute average deviation (AAD). As a result, the final model (QP-4-8-1) with minimum RMSE and AAD as well as the highest R(2) was selected to navigate the fabrication of the blended solution. Therefore, the model was applied to obtain the optimum initial level of the input variables which were included temperature 303-323 K, x[gua], 0-0.033, x[MDAE], 0.3-0.4, and x[H2O], 0.7-1.0. Moreover, the model has obtained the relative importance ordered of the variables which included x[gua]>temperature>x[MDEA]>x[H2O]. Therefore, none of the variables was negligible in the fabrication. Furthermore, the model predicted the optimum points of the variables to minimize the viscosity which was validated by further experiments. The validated results confirmed the model schedulability. Accordingly, ANN succeeds to model the initial components of the blended solutions as absorber of CO2 capture in separation technologies that is able to industries scale up.
    Matched MeSH terms: Viscosity
  11. Yasin MH, Ishak A, Pop I
    Sci Rep, 2015;5:17848.
    PMID: 26647651 DOI: 10.1038/srep17848
    The steady two-dimensional stagnation-point flow and heat transfer past a permeable stretching/shrinking sheet with effects of viscous dissipation, Joule heating and partial velocity slip in the presence of a magnetic field is investigated. The partial differential equations are reduced to nonlinear ordinary differential equations by using a similarity transformation, before being solved numerically by shooting technique. Results indicate that the skin friction coefficient and the local Nusselt number increase as magnetic parameter increases. It is found that for the stretching sheet the solution is unique while for the shrinking sheet there exist nonunique solutions (dual solutions) in certain range of parameters. The stability analysis shows that the upper branch solution is stable while the lower branch solution is unstable.
    Matched MeSH terms: Viscosity
  12. Ullah I, Khan I, Shafie S
    Sci Rep, 2017 04 25;7(1):1113.
    PMID: 28442747 DOI: 10.1038/s41598-017-01205-5
    Unsteady mixed convection flow of Casson fluid towards a nonlinearly stretching sheet with the slip and convective boundary conditions is analyzed in this work. The effects of Soret Dufour, viscous dissipation and heat generation/absorption are also investigated. After using some suitable transformations, the unsteady nonlinear problem is solved by using Keller-box method. Numerical solutions for wall shear stress and high temperature transfer rate are calculated and compared with previously published work, an excellent arrangement is followed. It is noticed that fluid velocity reduces for both local unsteadiness and Casson parameters. It is likewise noticed that the influence of a Dufour number of dimensionless temperature is more prominent as compared to species concentration. Furthermore, the temperature was found to be increased in the case of nonlinear thermal radiation.
    Matched MeSH terms: Viscosity
  13. Mbous YP, Hayyan M, Wong WF, Looi CY, Hashim MA
    Sci Rep, 2017 02 01;7:41257.
    PMID: 28145498 DOI: 10.1038/srep41257
    In this study, the anticancer potential and cytotoxicity of natural deep eutectic solvents (NADESs) were assessed using HelaS3, PC3, A375, AGS, MCF-7, and WRL-68 hepatic cell lines. NADESs were prepared from choline chloride, fructose, or glucose and compared with an N,N-diethyl ethanolammonium chloride:triethylene glycol DES. The NADESs (98 ≤ EC50 ≥ 516 mM) were less toxic than the DES (34 ≤ EC50 ≥ 120 mM). The EC50 values of the NADESs were significantly higher than those of the aqueous solutions of their individual components but were similar to those of the aqueous solutions of combinations of their chief elements. Due to the uniqueness of these results, the possibility that NADESs could be synthesized intracellularly to counterbalance the cytotoxicity of their excess principal constituents must be entertained. However, further research is needed to explore this avenue. NADESs exerted cytotoxicity by increasing membrane porosity and redox stress. In vivo, they were more destructive than the DES and induced liver failure. The potential of these mixtures was evidenced by their anticancer activity and intracellular processing. This infers that they can serve as tools for increasing our understanding of cell physiology and metabolism. It is likely that we only have begun to comprehend the nature of NADESs.
    Matched MeSH terms: Viscosity
  14. Normah Ismail, Nurul Asyiraf Abdul Jabar
    Scientific Research Journal, 2012;9(1):29-42.
    MyJurnal
    Collagen was extracted from catfish (Clarias gariepnus) waste using 0.5M acetic acid and its subsequent precipitation in 2.6M NaCl. The resultant collagen was analysed with respect to its moisture content and physicochemical properties including yield, pH, protein content, colour, odour and thermal stability. A yield of 16.4% and positive collagen attributes indicate that catfish waste has potential as a collagen source. The snowy white, crystal-like and light textured collagen comprises of 5.97% protein and 0.46% moisture, and exhibits a pH of 4.75. Sensory evaluation indicates that the collagen has a slight fishy odour. Viscosity analysis indicates a steady decrease with increasing temperature over the range considered (20-50°C). The pale colour exhibited and limited odour emitted by the extracted collagen indicate that catfish waste collagen could be applied in the food industry without resulting in any undesirable food products attributes. Differential Scanning Calorimetry (DSC) analysis indicated that the collagen exhibits good thermal stability and denatures at a high temperature in a similar manner to mammalian collagen.
    Matched MeSH terms: Viscosity
  15. Muhammad Khairul Anuar Mohamed, Nor Aida Zuraimi Md Noar, Mohd Zuki Salleh, Anuar Ishak
    Sains Malaysiana, 2016;45:189-296.
    In this paper, the problem of free convection boundary layer flow on a horizontal circular cylinder in a nanofluid with viscous dissipation and constant wall temperature is investigated. The transformed boundary layer equations are solved numerically using finite difference scheme namely the Keller-box method. Numerical solutions were obtained for the reduced skin friction coefficient, Nusselt number and Sherwood number as well as the velocity and temperature profiles.The features of the flow and heat transfer characteristics for various values of the Brownian motion parameter, thermophoresis parameter, Lewis number and Eckert number were analyzed and discussed.
    Matched MeSH terms: Viscosity
  16. Abdullahi A, Choudhury I, Azuddin M, Nahar N
    Sains Malaysiana, 2017;46:477-483.
    A suitable and cost-effective microfabrication technique for processing aluminum micropart is required, as the choice
    of aluminum microparts for aerospace, electronics and automobile components is preferred over other metals due to its
    excellent properties. Meanwhile, powder injection molding (PIM) is identified as an economical manufacturing technique
    for processing ceramic and micro-metal powders into microparts and or components. Therefore, this study investigates
    formulation and processing of aluminum PIM feedstock using a custom-made machine. The investigation is focused on
    the effect of mixing process parameters (powder loading, rotor speed and mixing temperature) and the suitability of
    the backbone polymer. The formulated PIM feedstock constituents are paraffin wax (PW), stearic acid (SA), high-density
    polyethylene (HDPE)/ medium-density polyethylene (MDPE) alternatively and aluminum micro-metal powder. Taguchi
    method is used for the design of experiments (DOEs) and analysis. In addition, response surface methodology (RSM) is
    employed to develop empirical viscosity models. The optimum powder-binder mixing ratio of 58:42 vol. % with rotor
    speed of 43 rpm were determined for preparing aluminum PIM feedstock using mini-lab mixer developed. The empirical
    model developed for aluminum PIM feedstock viscosity shows a good fit with R2
    values of 0.84 using HDPE and 0.96 for
    MDPE binder system. This investigation demonstrates preparation and suitability of aluminum PIM feedstock using waxbased
    binder system.
    Matched MeSH terms: Viscosity
  17. Jumat Salimon, Nadia Salih, Yousif E
    Sains Malaysiana, 2012;41:1239-1244.
    A series of ester compounds derived from ricinoleic acid to be used as biolubricants base stock have been synthesized. The resulting products were confirmed by FTIR and NMR analyses. The synthesis was carried out in three stages: epoxidation of ricinoleic acid; synthesis of 10,12-dihydroxy-9-acyloxystearic acid from epoxidized ricinoleic acid with various fatty acids and esterification of the acyloxystearic acid products with octanol to yield octyl-10,12-dihydroxy-9-acyloxystearate. The viscosities, flash points and pour points (PP) behavior of the products were measured. The resulting esters had an increased in molar weight and viscosity and decreased in pour points as compared to ricinoleic acid.
    Matched MeSH terms: Viscosity
  18. Shekholeslami M, Ashorynejad HR, Domairry D, Ishak Hashim
    Sains Malaysiana, 2012;41:1281-1285.
    In this paper, the problem of laminar viscous flow in a semi-porous channel in the presence of transverse magnetic field is studied. The Optimal Homotopy Asymptotic Method (OHAM) is employed to approximate the solution of the system of nonlinear differential equations governing the problem. The influence of the Hartmann number (Ha) and the Reynolds number (Re) on the flow was investigated. The results of the OHAM were compared with homotopy analysis method (HAM) and variation iteration method (VIM) results.
    Matched MeSH terms: Viscosity
  19. Rida Tajau, Mohd hilmi Mahmood, Mek Zah Salleh, Khairul Zaman Mohd dahlan, Rosley Che ismail, Sharilla Muhammad Faisal, et al.
    Sains Malaysiana, 2013;42:459-467.
    In recent years, there are growing trends in using palm oil as raw materials in radiation curable resins production. In this study, the acrylated palm oil resins i.e. the EPOLA (epoxidized palm oil acrylate) and the POBUA (palm oil based urethane acrylate) were synthesized using two different systems, i.e. the 25 liter pilot scale reactor synthesis system and the 2 liter (L) laboratory scale reactor synthesis system through chemical processes known as acrylation and isocyanation. In this
    paper, the property of the acrylated resins which were produced by these two systems were evaluated and compared between each other. Their properties were characterized using the Fourier transform infrared (FTIR) spectrophotometer for functional group identification; the gel permeation chromatography (GPC) for molecular weight (Mw) determination, the Brookfield viscometer for viscosity measurements, the acid values (AV) and the oxirane oxygen contents (OOC) analysis. As a result, the production process for both the 2 L and 25 L reactor system were found to be time consuming and the main advantages for the 25 L reactor was its higher productivity as compared with the 2 L reactor system with the same synthesis process parameters i.e. the temperatures and the experimental methods. Besides that, the 25 L reactor synthesis
    process was found to be safe, easy to control and served unpolluted process to the environments. The final products, the acrylated palm oil resins were formulated into ultraviolet (UV) curable compounds before subjecting them under UVirradiation. As a result, the UV-curable palm oil resins showed potential uses as pressure sensitive adhesives, printing inks including overprint varnishes (OPV) and coatings.
    Matched MeSH terms: Viscosity
  20. Marina A, Wan Rosli WI, Neoh S
    Sains Malaysiana, 2014;43:1311-1315.
    The effect of corn silk or Zea mays extract on the physicochemical changes of virgin coconut oil was studied during three consecutive days of deep frying. There were three types of oil blend systems used: virgin coconut oil without antioxidant as control system; virgin coconut oil with butylated hydroxytoluene (BHT) as synthetic antioxidant and virgin coconut oil with Zea mays extract as natural antioxidant. The oil quality was assessed by measuring the colour, viscosity, peroxide, p-anisidine, free fatty acids, totox and iodine value. The results show that Zea mays extract delayed the oil deterioration. The Zea mays extract significantly (p<0.05) lowered the rate of oxidation in virgin coconut oil compared to control oil and was comparable to BHT. Zea mays extract did not change the sensory profiles of French fries which was shown by insignificant difference (p<0.05) between Zea mays and control fries for all sensory attributes (colour, taste, aroma, crispiness, oiliness and overall quality). In general, the Zea may extract was capable of extending the stability and quality of virgin coconut oil and therefore has potential as new source of natural antioxidant for use in deep frying.
    Matched MeSH terms: Viscosity
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