Displaying publications 1 - 20 of 58 in total

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  1. Development and physical characterization of polymer-fish oil bigel (hydrogel/oleogel) system as a transdermal drug delivery vehicle
    Rehman K, Mohd Amin MC, Zulfakar MH
    J Oleo Sci, 2014;63(10):961-70.
    PMID: 25252741
    Polymer-Fish oil bigel (hydrogel/oleogel colloidal mixture) was developed by using fish oil and natural (sodium alginate) and synthetic (hydroxypropyl methylcellulose) polymer for pharmaceutical purposes. The bigels were closely monitored and thermal, rheological and mechanical properties were compared with the conventional hydrogels for their potential use as an effective transdermal drug delivery vehicle. Stability of the fish oil fatty acids (especially eicosapentanoic acid, EPA and docosahexanoic acid, DHA) was determined by gas chromatography and the drug content (imiquimod) was assessed with liquid chromatography. Furthermore, in vitro permeation study was conducted to determine the capability of the fish oil-bigels as transdermal drug delivery vehicle. The bigels showed pseudoplastic rheological features, with excellent mechanical properties (adhesiveness, peak stress and hardness), which indicated their excellent spreadability for application on the skin. Bigels prepared with mixture of sodium alginate and fish oil (SB1 and SB2), and the bigels prepared with the mixture of hydroxypropyl methylcellulose and fish oil (HB1-HB3) showed high cumulative permeation and drug flux compared to hydrogels. Addition of fish oil proved to be beneficial in increasing the drug permeation and the results were statistically significant (p < 0.05, one-way Anova, SPSS 20.0). Thus, it can be concluded that bigel formulations could be used as an effective topical and transdermal drug delivery vehicle for pharmaceutical purposes.
    Matched MeSH terms: Colloids
  2. Transport and retention behavior of carbonaceous colloids in natural aqueous medium: Impact of water chemistry
    Jahan S, Alias YB, Bakar AFBA, Yusoff IB
    Chemosphere, 2019 Feb;217:213-222.
    PMID: 30415119 DOI: 10.1016/j.chemosphere.2018.11.015
    Carbon based materials are emerging as a sustainable alternative to their metal-oxide counterparts. However, their transport behavior under natural aqueous environment is poorly understood. This study investigated the transport and retention profiles of carbon nanoparticles (CNPs) and graphene oxide quantum dots (GOQDs) through column experiments in saturated porous media. CNPs and GOQDs (30 mg/L) were dispersed in natural river water (RW) and passed through the column at a flow rate of 1 mL/min, which mimicking the natural water flow rate. After every 10 min, the column effluents were collected and the mass recovery and retention profiles were monitored. Results indicated that the transport of both carbonaceous colloids was predominantly controlled by surface potential and ionic composition of natural water. The CNPs with its high surface potential (-40 mV) exhibited more column transport and was less susceptible to solution pH (5.6-6.8) variation as compared to GOQDs (-24 mV). The results showed that, monovalent salt (NaCl) was one of the dominating factors for the retention and transport of carbonaceous colloids compared to divalent salt (CaCl2). Furthermore, the presence of natural organic matter (NOM) increased the transport of both carbonaceous colloids and thereby decreases the tendency for column retention.
    Matched MeSH terms: Colloids/chemistry*
  3. Do colloids in comparison to crystalloids for fluid resuscitation improve mortality?
    Naing CM, Win DK
    Trans R Soc Trop Med Hyg, 2010 May;104(5):311-2.
    PMID: 20206954 DOI: 10.1016/j.trstmh.2010.02.001
    Permanent neurological impairment or death arising from hospital-acquired hyponatremia in both children and adults is well documented. The choice of intravenous fluids for fluid resuscitation in critically ill patients is a top priority in evidence-based medicine. The question of whether colloids in comparison to crystalloids can improve mortality in such cases remains to be answered. Well powered, randomized clinical trials addressing the comparative efficacy of different types of intravenous fluids is a high priority as is the ethical justification for such trials. The understanding of the pathophysiological process serves important information on clinical practice.
    Matched MeSH terms: Colloids/adverse effects; Colloids/therapeutic use*
  4. Fulltext Efficacy of chitosan derivative films versus hydrocolloid dressing on superficial wounds
    Halim AS, Nor FM, Mat Saad AZ, Mohd Nasir NA, Norsa'adah B, Ujang Z
    J Taibah Univ Med Sci, 2018 Dec;13(6):512-520.
    PMID: 31435371 DOI: 10.1016/j.jtumed.2018.10.004
    Objectives: Chitosan, the N-deacetylated derivative of chitin, has useful biological properties that promote haemostasis, analgesia, wound healing, and scar reduction; chitosan is bacteriostatic, biocompatible, and biodegradable. This study determined the efficacy of chitosan derivative film as a superficial wound dressing.

    Methods: This multicentre randomised controlled trial included 244 patients, of whom 86 were treated with chitosan derivative film and 84 with hydrocolloid. The percentage of epithelisation, as well as patient comfort, clinical signs, and patient convenience in application and removal of the dressings were assessed.

    Results: The primary outcome of this study was the percentage of epithelisation. Except for race (p = 0.04), there were no significant differences between groups in sex, age, antibiotic usage, or initial wound size (p > 0.05). There was no significant difference in the mean epithelisation percentage between groups (p = 0.29). Patients using chitosan derivative film experienced more pain during removal of dressing than those in the hydrocolloid group (p = 0.007). The chitosan derivative film group showed less exudate (p = 0.036) and less odour (p = 0.024) than the control group. Furthermore, there were no significant differences between groups in terms of adherence, ease of removal, wound drainage, erythema, itchiness, pain, and tenderness. No oedema or localised warmth was observed during the study.

    Conclusion: This study concluded that chitosan derivative film is equivalent to hydrocolloid dressing and can be an option in the management of superficial and abrasion wounds.

    Clinical trial No: NMRR-11-948-10565.

    Matched MeSH terms: Colloids
  5. Characterization of polymeric micelles for pulmonary delivery of beclomethasone dipropionate
    Gaber NN, Darwis Y, Peh KK, Tan YT
    J Nanosci Nanotechnol, 2006 10 20;6(9-10):3095-101.
    PMID: 17048523
    The potential of using poly-(ethylene oxide)-block-distearoyl phosphatidyl-ethanolamine (mPEG-DSPE) polymer to prepare BDP-loaded micelles with high entrapment efficiency and mass median aerodynamic diameter of less than 5 microm demonstrating sustained release properties was evaluated. The result showed that lyophilized BDP-loaded polymeric micelles with entrapment efficiency of more than 96% could be achieved. Entrapment efficiency was affected by both the drug to polymer molar ratio and the amount of drug used. Investigation using FTIR and DSC confirmed that there was no chemical or physical interaction and the drug was molecularly dispersed within the micelles. TEM images showed that the drug-loaded polymeric micelles were spherical in shape with multivesicular morphology. Further analysis by photon correlation spectroscopy indicated that the particle size of the BDP-loaded micelles was about 22 nm in size. In vitro drug release showed a promising sustained release profile over six days following the Higuchi model. The mass median aerodynamic diameter and fine particle fraction were suitable for pulmonary delivery. Moreover, the small amount of deposited drug in the induction port (throat deposition) suggested possible reduction in incidence of oropharyngeal candidiasis, a side effect normally associated with inhaled corticosteroids therapy. The high encapsulation efficiency, comparable inhalation properties, sustained release behavior together with biocompatibility nature of the polymer support the potential of BDP-loaded polymeric micelles as a versatile delivery system to be used in the treatment of asthma and chronic obstructive pulmonary disease.
    Matched MeSH terms: Colloids/chemistry*
  6. Fulltext Highly Sensitive Fluorescence Sensor for Carrageenan from a Composite Methylcellulose/Polyacrylate Membrane
    Hassan RA, Heng LY, Tan LL
    Sensors (Basel), 2020 Sep 04;20(18).
    PMID: 32899886 DOI: 10.3390/s20185043
    Carrageenans are linear sulphated polysaccharides that are commonly added into confectionery products but may exert a detrimental effect to human health. A new and simpler way of carrageenan determination based on an optical sensor utilizing a methylcellulose/poly(n-butyl acrylate) (Mc/PnBA) composite membrane with immobilized methylene blue (MB) was developed. The hydrophilic Mc polymer membrane was successfully modified with a more hydrophobic acrylic polymer. This was to produce an insoluble membrane at room temperature where MB reagent could be immobilized to build an optical sensor for carrageenan analysis. The fluorescence intensity of MB in the composite membrane was found to be proportional to the carrageenan concentrations in a linear manner (1.0-20.0 mg L-1, R2 = 0.992) and with a detection limit at 0.4 mg L-1. Recovery of spiked carrageenan into commercial fruit juice products showed percentage recoveries between 90% and 102%. The optical sensor has the advantages of improved sensitivity and better selectivity to carrageenan when compared to other types of hydrocolloids. Its sensitivity was comparable to most sophisticated techniques for carageenan analysis but better than other types of optical sensors. Thus, this sensor provides a simple, rapid, and sensitive means for carageenan analysis.
    Matched MeSH terms: Colloids
  7. Fulltext Investigation on the use of graphene oxide as novel surfactant to stabilize weakly charged graphene nanoplatelets
    Kazi SN, Badarudin A, Zubir MN, Ming HN, Misran M, Sadeghinezhad E, et al.
    Nanoscale Res Lett, 2015;10:212.
    PMID: 25995712 DOI: 10.1186/s11671-015-0882-7
    This paper presents a unique synergistic behavior between a graphene oxide (GO) and graphene nanoplatelet (GnP) composite in an aqueous medium. The results showed that GO stabilized GnP colloid near its isoelectric point and prevented rapid agglomeration and sedimentation. It was considered that a rarely encountered charge-dependent electrostatic interaction between the highly charged GO and weakly charged GnP particles kept GnP suspended at its rapid coagulation and phase separation pH. Sedimentation and transmission electron microscope (TEM) micrograph images revealed the evidence of highly stable colloidal mixtures while zeta potential measurement provided semi-quantitative explanation on the mechanism of stabilization. GnP suspension was confirmed via UV-vis spectral data while contact angle measurement elucidated the close resemblance to an aqueous solution indicating the ability of GO to mediate the flocculation prone GnP colloids. About a tenfold increase in viscosity was recorded at a low shear rate in comparison to an individual GO solution due to a strong interaction manifested between participating colloids. An optimum level of mixing ratio between the two constituents was also obtained. These new findings related to an interaction between charge-based graphitic carbon materials would open new avenues for further exploration on the enhancement of both GO and GnP functionalities particularly in mechanical and electrical domains.
    Matched MeSH terms: Colloids
  8. Fulltext D-Optimal mixture design on melting and textural properties of dark chocolate as affected by cocoa butter substitution with Xanthan gum/Guar gum blends
    Amir, I.Z., Sharon, W.X.R., Syafiq, A.
    International Food Research Journal, 2013;20(4):1991-1995.
    MyJurnal
    Impacts and relationships on physicochemical properties in dark chocolate produced from different substitution for cocoa butter by Xanthan gum (XG) and Guar gum (GG) blends were determined using D-optimal mixture design. This study involved three levels of substitution which are 5%, 10% and 15% with constrained cocoa butter content and random blend of gums. Linear design models were applied to analyze parameters including texture (hardness) measurement and melting profile of fat crystal. Products experienced undesirable raises of hardness jointly with the increment of gums incorporation across the level of cocoa butter replacement from 5% to 15%. Similar trend was also agreed with the melting behavior of products as their melting point increased with the gradual diminution of cocoa butter. After all, the replacement of cocoa butter using hydrocolloids was deemed possible as there were products whose melting point and hardness fell in the acceptable range.
    Matched MeSH terms: Colloids
  9. Fulltext In situ ophthalmic gel forming systems of poloxamer 407 and hydroxypropyl methyl cellulose mixtures for sustained ocular delivery of chloramphenicole: optimization study by factorial design
    Kurniawansyah IS, Rusdiana T, Sopyan I, Ramoko H, Wahab HA, Subarnas A
    Heliyon, 2020 Nov;6(11):e05365.
    PMID: 33251348 DOI: 10.1016/j.heliyon.2020.e05365
    Background: Conventional drug delivery systems have some major drawbacks such as low bioavailability, short residence time and rapid precorneal drainage. An in situ gel drug delivery system provides several benefits, such as prolonged pharmacological duration of action, simpler production techniques, and low cost of manufacturing. This research aims to get the optimum formula of chloramphenicol in situ gel based on the physical evaluation.

    Methods: The effects of independent variables (poloxamer 407 and hydroxypropyl methyl cellulose (HPMC) concentration) on various dependent variables (gelling capacity, pH and viscosity) were investigated by using 32 factorial design and organoleptic evaluation was done with descriptive analysis.

    Results: The optimized formula of chloramphenicol in situ gel yielded 9 variations of poloxamer 407 and HPMC bases composition in % w/v as follows, F1 (5; 0.45), F2 (7.5; 0.45), F3 (10; 0.45), F4 (5; 0.725), F5 (7.5; 0.725), F6 (10; 0.725), F7 (5; 1), F8 (7.5; 1), F9 (10; 1). The results indicated that the organoleptic, pH, and gelling capacity parameters matched all formulas (F1-F9), however, the viscosity parameter only matched F3, F6, F8, and F9. Based on factorial design, F6 had the best formula with desirability value of 0.54, but the design recommended that formula with the composition bases of poloxamer 407 and HPMC at the ratio of 8.16 % w/v and 0.77 % w/v, respectively, was the optimum formula with a desirability value of 0.69.

    Conclusion: All formulas have met the Indonesian pharmacopoeia requirements based on the physical evaluation, especially formula 6 (F6), which was supported by the result of factorial design analysis.

    Matched MeSH terms: Colloids
  10. Fulltext Room temperature radiolytic synthesized Cu@CuAlO(2)-Al(2)O(3) nanoparticles
    Abedini A, Saion E, Larki F, Zakaria A, Noroozi M, Soltani N
    Int J Mol Sci, 2012;13(9):11941-53.
    PMID: 23109893 DOI: 10.3390/ijms130911941
    Colloidal Cu@CuAlO(2)-Al(2)O(3) bimetallic nanoparticles were prepared by a gamma irradiation method in an aqueous system in the presence of polyvinyl pyrrolidone (PVP) and isopropanol respectively as a colloidal stabilizer and scavenger of hydrogen and hydroxyl radicals. The gamma irradiation was carried out in a (60)Co gamma source chamber with different doses up to 120 kGy. The formation of Cu@CuAlO(2)-Al(2)O(3) nanoparticles was observed initially by the change in color of the colloidal samples from colorless to brown. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of bonds between polymer chains and the metal surface at all radiation doses. Results of transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD) showed that Cu@CuAlO(2)-Al(2)O(3) nanoparticles are in a core-shell structure. By controlling the absorbed dose and precursor concentration, nanoclusters with different particle sizes were obtained. The average particle diameter increased with increased precursor concentration and decreased with increased dose. This is due to the competition between nucleation, growth, and aggregation processes in the formation of nanoclusters during irradiation.
    Matched MeSH terms: Colloids/chemical synthesis; Colloids/chemistry
  11. Fulltext Pressure ulcers--randomised controlled trial comparing hydrocolloid and saline gauze dressings
    Chang KW, Alsagoff S, Ong KT, Sim PH
    Med J Malaysia, 1998 Dec;53(4):428-31.
    PMID: 10971989
    An open comparative randomised study comparing the performance of hydrocolloid dressings (DuoDERM CGF) to saline gauze dressings in the treatment of pressure ulcers was done to evaluate the overall dressing performance, wound healing and cost effectiveness. Thirty-four subjects were enrolled at the University Hospital, Kuala Lumpur over a 643 days period. Inclusion criteria were Stage II or III pressure ulcers, at least 18 years of age and written informed consent. Only one pressure ulcer per subject was enrolled in the study. Patients with infected pressure ulcers, diabetes mellitus, an immuno-compromised status and known sensitivity to the study dressings were excluded. Subjects who met the enrollment criteria were randomised to one of the two dressing regimes. They were expected to participate in the study for a maximum of eight weeks or until the pressure ulcer healed, which ever occurred first. Overall subject age averaged 58 years and the mean duration of pressure ulcer existence was about 1 month. Twenty-one of the thirty-four ulcers enrolled were stage II and thirteen were stage III. The majority of the ulcers (88%) were located in the sacral area and seventeen subjects (50%) were incontinent. In the evaluation of dressing performance in terms of adherence to wound bed, exudate handling ability, overall comfort and pain during dressing removal; all favoured the hydrocolloid dressing by a statistically significant margin (p < 0.001). Subjects assigned the hydrocolloid dressing experienced a mean 34% reduction from their baseline surface area measurement compared to a mean 9% increase by subjects assigned gauze dressings. This was not statistically significant (p = 0.2318). In cost evaluation of the study products, there was no statistical significance in the total cost of wound management per subject. When only labour time and cost was evaluated, there was a statistically significant advantage towards hydrocolloid dressings.
    Matched MeSH terms: Colloids/therapeutic use*
  12. Fulltext Mixed biopolymer systems based on starch
    Abd Elgadir M, Akanda MJ, Ferdosh S, Mehrnoush A, Karim AA, Noda T, et al.
    Molecules, 2012 Jan 09;17(1):584-97.
    PMID: 22231495 DOI: 10.3390/molecules17010584
    A binary mixture of starch-starch or starch with other biopolymers such as protein and non-starch polysaccharides could provide a new approach in producing starch-based food products. In the context of food processing, a specific adjustment in the rheological properties plays an important role in regulating production processing and optimizing the applicability, stability, and sensory of the final food products. This review examines various biopolymer mixtures based on starch and the influence of their interaction on physicochemical and rheological properties of the starch-based foods. It is evident that the physicochemical and rheological characteristics of the biopolymers mixture are highly dependent on the type of starch and other biopolymers that make them up mixing ratios, mixing procedure and presence of other food ingredients in the mixture. Understanding these properties will lead to improve the formulation of starch-based foods and minimize the need to resort to chemically modified starch.
    Matched MeSH terms: Colloids/chemistry
  13. Fulltext Effect of different hydrocolloids on the physicochemical properties, microbiological quality and sensory acceptance of fermented cassava ( tapai ubi ) ice cream
    Halim, N.R.A., Shukri, W.H.Z., Lani, M.N., Sarbon, N.M.
    International Food Research Journal, 2014;21(5):1825-1836.
    MyJurnal
    The aim of this work is to study the effect of hydrocolloids; guar gum (GG), xanthan gum (XG) and carboxymethyl cellulose (CMC) on the physicochemical properties, microbiological quality and sensory properties in order to investigate the potential of applying fermented cassava (tapai ubi) in ice cream. Fermented cassava ice cream (FCI) incorporated with the three types of hydrocolloid was prepared and the protein content, pH value, overrun, colour, hardness, microstructure, FTIR spectrum and sensory acceptance of all samples were determined. Fermented cassava ice cream incorporated with XG showed the highest protein content (14.88%), pH value (pH 6.07), and overrun value (4.27%) as compared to the fermented cassava ice cream incorporated with GG and CMC. Meanwhile, ice cream incorporated with GG possessed the highest L* (94.43) and hardness (3693.15 g) value as compared to XG and CMC. The microstructure study showed that the difference in uniformity at the interface obtained with different types of the hydrocolloids added demonstrated the effect of fat absorption at the air interfaces. The FTIR spectrum investigated indicated that the addition of the fermented cassava to FCI had increased the OH group in the ice cream as compared to the control. All samples were microbial safe as the total plate counts in all samples were below the standard as prescribed in Food Act 1983 with no presence of E. coli . In conclusion, fermented cassava ice cream with XG showed the good quality in terms of its pH value, overrun, total plate count and overall acceptability.
    Matched MeSH terms: Colloids
  14. Fulltext Effect of different types of hydrocolloids on the physical and sensory properties of ice cream with fermented glutinous rice ( tapai pulut)
    Shukri, W.H.Z., Hamzah, E.N.H., Halim, N.R.A., Isa, M.I.N., Sarbon, N.M.
    International Food Research Journal, 2014;21(5):1777-1787.
    MyJurnal
    The aim of this work is to study the effect of hydrocolloids (guar gum, xanthan gum and carboxymethyl cellulose (CMC) on the physical properties and sensory evaluation of ice cream produced in order to investigate the potential of applying fermented glutinous rice (tapai pulut) as a value-added ingredient. The addition of 25% fermented glutinous rice was the most reliable amount to enhance the physical and sensory properties of ice cream when incorporating hydrocolloids. The addition of hydrocolloids significantly (p < 0.05) increased the pH, firmness, overrun, and melting rate of fermented glutinous rice ice cream. The addition of guar gum scored the highest firmness value (5403 g) followed by CMC (4630 g) and xanthan gum (3481g). Fermented glutinous rice ice cream with xanthan gum added, induced a noticeable change in overrun value (62%) while the addition of CMC decreased the melting rate compared to the control. The FTIR spectrum of fermented glutinous rice ice cream with different hydrocolloids containing carboxyl, amide and carbonyl group was appeared at 3362-3379 cm-1 , 1639-1640 cm-1 and 1026-1064 cm-1, respectively. In conclusion, the addition of xanthan gum presented great potential to improve the quality of fermented glutinous rice ice cream produced in terms of its firmness, overrun and melting rate.
    Matched MeSH terms: Colloids
  15. Initial stages of GaAs/au eutectic alloy formation for the growth of GaAs nanowires
    Rosnita M, Yussof W, Zuhairi I, Zulkafli O, Samsudi S
    Sains Malaysiana, 2012;41:1133-1138.
    Annealing temperature plays an important role in the formation of an Au-Ga eutectic alloy. The effects of the annealing temperature on gold nanoparticles colloid and substrate surface were studied using AFM, FE-SEM and TEM. At 600oC, the layer of gold colloids particle formed an island in the state of molten eutectic alloy and absorbed evaporated metalorganics to formed nanowire (NW) underneath the alloy. Pit formed on the substrate surface due to the chemical reactions during the annealing process have an impact on the direction of growth of the NW. Without annealing, the NW formed vertically on the GaAs (100) surface. The growth direction depends on the original nucleation facets and surface energy when annealed. When annealed, the wire base is large and curved due to the migration of Ga atoms on the substrate surface towards the tip of the wire and the line tension between the substrate surface and gold particle.
    Matched MeSH terms: Colloids
  16. TiO₂ nanoparticle transport and retention through saturated limestone porous media under various ionic strength conditions
    Esfandyari Bayat A, Junin R, Derahman MN, Samad AA
    Chemosphere, 2015 Sep;134:7-15.
    PMID: 25889359 DOI: 10.1016/j.chemosphere.2015.03.052
    The impact of ionic strength (from 0.003 to 500mM) and salt type (NaCl vs MgCl2) on transport and retention of titanium dioxide (TiO2) nanoparticles (NPs) in saturated limestone porous media was systematically studied. Vertical columns were packed with limestone grains. The NPs were introduced as a pulse suspended in aqueous solutions and breakthrough curves in the column outlet were generated using an ultraviolent-visible spectrometry. Presence of NaCl and MgCl2 in the suspensions were found to have a significant influence on the electrokinetic properties of the NP aggregates and limestone grains. In NaCl and MgCl2 solutions, the deposition rates of the TiO2-NP aggregates were enhanced with the increase in ionic strength, a trend consistent with traditional Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Furthermore, the NP aggregates retention increased in the porous media with ionic strength. The presence of salts also caused a considerable delay in the NPs breakthrough time. MgCl2 as compared to NaCl was found to be more effective agent for the deposition and retention of TiO2-NPs. The experimental results followed closely the general trends predicted by the filtration and DLVO calculations. Overall, it was found that TiO2-NP mobility in the limestone porous media depends on ionic strength and salt type.
    Matched MeSH terms: Colloids/chemistry
  17. Fulltext Influence of dose on particle size and optical properties of colloidal platinum nanoparticles
    Gharibshahi E, Saion E
    Int J Mol Sci, 2012;13(11):14723-41.
    PMID: 23203091 DOI: 10.3390/ijms131114723
    Attempts to produce colloidal platinum nanoparticles by using steady absorption spectra with various chemical-based reduction methods often resulted in the fast disappearance of the absorption maxima leaving reduced platinum nanoparticles with little information on their optical properties. We synthesized colloidal platinum nanoparticles in an aqueous solution of polyvinyl pyrrolidone by gamma radiolytic reduction method, which produced steady absorption spectra of fully reduced and highly pure platinum nanoparticles free from by-product impurities or reducing agent contamination. The average particle size was found to be in the range of 3.4–5.3 nm and decreased with increasing dose due to the domination of nucleation over ion association in the formation of metal nanoparticles by the gamma radiolytic reduction method. The platinum nanoparticles exhibit optical absorption spectra with two absorption peaks centered at about 216 and 264 nm and the peaks blue shifted to lower wavelengths with decreasing particle size. The absorption spectra of platinum nanoparticles were also calculated using quantum mechanical treatment and coincidently a good agreement was obtained between the calculated and measured absorption peaks at various particle sizes. This indicates that the 216 and 264-nm absorption peaks of platinum nanoparticles conceivably originated from the intra-band transitions of conduction electrons of (n = 5, l = 2) and (n = 6, l = 0) energy states respectively to higher energy states. The absorption energies, i.e., conduction band energies of platinum nanoparticles derived from the absorption peaks increased with increasing dose and decreased with increasing particle size.
    Matched MeSH terms: Colloids
  18. Investigation of the gelation mechanism between amino acid surfactant based microemulsion and Kappa-Carrageenan gel network
    Nasima Akter, Shahidan Radiman, Faizal Mohamed, Nazaruddin Ramly, Putra EGR, Rini AS
    Sains Malaysiana, 2014;43:203-209.
    Kappa-carrageenan is one form of necessary hydrocolloid. Hydrocolloids are macromolecular materials, which swell upon absorption of water; in some cases, forming a stiff gel in the presence of additives. This property is very important to suspend nanocarriers into gel network, which provide them long time stability at a varying temperature range. In this work, we prepared microemulsion and trapped these particles inside the kappa-carrageenan gel network. The microemulsion was composed of sodium N-lauroylsarcosinate hydrate (SNLS), oleic acid and deionized water. The purpose of this study was to immobilize them into the gel network, giving longer shelf life at a range of temperatures for oral drug delivery. Morphological properties were investigated by transmission electron microscope (TEM), dynamic light scattering (DLS) and Fourier transform infrared (FTIR) spectra. The TEM results showed that microemulsions are trapped in the gel network, and the diameter of the microemulsions are below 100 nm, which is comparable with the DLS results. The important functional groups of kappa-carrageenan and microemulsion were shown from the FTIR result of the complex microemulsion gel. These results confirmed the interaction between SNLS based microemulsion and kappa- carrageenan gel.
    Matched MeSH terms: Colloids
  19. Poly(cyclodextrin-ionic liquid) based ferrofluid: A new class of magnetic colloid for dispersive liquid phase microextraction of polycyclic aromatic hydrocarbons from food samples prior to GC-FID analysis
    Yih Hui B, Mohamad Zain NN, Mohamad S, Varanusupakul P, Osman H, Raoov M
    Food Chem, 2020 Jun 01;314:126214.
    PMID: 31972404 DOI: 10.1016/j.foodchem.2020.126214
    Poly(β-cyclodextrin-ionic liquid) grafted magnetic nanoparticles combined with 1-octanol as supramolecular solvents (SUPRASs) presenting new ferrofluid was developed and successfully applied in the dispersive liquid-phase microextraction of seven representative polycyclic aromatic hydrocarbons. One variable at-a-time (OVAT) analysis and response surface methodology (RSM) were used for efficient optimization of the main variables. The calibration curves were found to be linear in the range of 0.1-150 ng mL-1 with correlation of determinations (R2) ranging from 0.9944 to 0.9986. Detection limits ranged at 0.02-0.07 ng mL-1 for all studied PAHs. The intra and inter-day precision values (RSD %) were in the range of 1.80%-7.56% and 2.97%-8.23%, respectively. The ferrofluid showed a satisfactory reproducibility between 1.72% and 5.90%, and acceptable recovery values at 84%-110% were obtained for the real samples analysis. The optimized method was successfully applied to access the content safety of the PAHs studied in a variety of commercial food and beverages available in Malaysia.
    Matched MeSH terms: Colloids
  20. Early fluid resuscitation in the management of major burns: ten years experience in Tabuk, Saudi Arabia
    Rahoma AH
    JUMMEC, 2002;7:127-131.
    During the period from January 1992 up to the end of July 2001, the Burns Unit in King Khalid C Hospital treated 1735 cases of burns. The burns cases were of varying causes, age groups, degree, depth and extent. The formula used in lTeating these burns patients was a modification of Parkland fonnula. The fluid used was Ringer lactate solution. This fluid was administered for the first 3 days post burn until the general condilion of the palient was sfabilized. Early oral intake was encouraged in aU patients and was started as early as the second or the third day. Colloids were given by the end of the third or even the fourth day and according to the individual patients' needs. The results of this treatment regime significantly avoided renal complications and ensured patient rehydration. KEYWORDS; Major burns, fluids resuscitation
    Matched MeSH terms: Colloids
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