Displaying publications 1 - 20 of 58 in total

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  1. Ramimoghadam D, Bagheri S, Abd Hamid SB
    Colloids Surf B Biointerfaces, 2015 Sep 1;133:388-411.
    PMID: 26073507 DOI: 10.1016/j.colsurfb.2015.02.003
    Magnetic iron oxide nanoparticles (MNPs) have emerged as highly desirable nanomaterials in the context of many research works, due to their extensive industrial applications. However, they are prone to agglomerate on account of the anisotropic dipolar attraction, and therefore misled the particular properties related to single-domain magnetic nanostructures. The surface modification of MNPs is quite challenging for many applications, as it involves surfactant-coating for steric stability, or surface modifications that results in repulsive electrostatic force. Hereby, we focus on the dispersion of MNPs and colloidal stability.
    Matched MeSH terms: Colloids*
  2. Loi MV, Wang QY, Lee JH
    Minerva Pediatr (Torino), 2023 Feb;75(1):49-61.
    PMID: 36282485 DOI: 10.23736/S2724-5276.22.06935-X
    Dengue is a mosquito-borne arboviral infection of increasing public health importance. Globally, children account for a significant proportion of infections. No pathogen-specific treatment currently exists, and the current approach to reducing disease burden is focused on preventative strategies such as vector control, epidemiological interventions, and vaccination in selected populations. Once infected, the mainstay of treatment is supportive, of which appropriate fluid management is a cornerstone. The timely provision of fluid boluses has historically been central to the management of septic shock. However, in patients with dengue shock, particular emphasis is placed on judicious fluid administration. Certain colloids such as hydroxyethyl starches and dextran, despite no longer being used routinely in intensive care units due to concerns of acute kidney injury and impairment of coagulation, are still commonly used in dengue shock syndrome. Current guidelines recommend initial crystalloid therapy, with consideration of colloids for severe or recalcitrant shock in patients with dengue. In this review, we discuss the pathophysiology of septic shock, and consider whether any differences in dengue exist that may warrant a separate approach to fluid therapy. We critically review the available evidence for fluid management in dengue, including the role of colloids. In dengue, there is increasing recognition of the importance of tailoring fluid therapy to phases of disease, with attention to the need for fluid "deresuscitation" once the critical phase of vascular leak passes.
    Matched MeSH terms: Colloids/therapeutic use
  3. Zamiri R, Zakaria A, Husin MS, Wahab ZA, Nazarpour FK
    Int J Nanomedicine, 2011;6:2221-4.
    PMID: 22114485 DOI: 10.2147/IJN.S23830
    In the present work, we prepared silver nanoparticles by laser ablation of pure silver plate in ethanol and then irradiated the silver nanoparticles using a 532 nm Q-switched Nd:YAG pulsed laser. Transmission electron microscopic images of the sample after irradiation clearly showed formation of big structures, such as microrods and microbelts in ethanol. The obtained microbelts had a width of about 0.166 μm and a length of 1.472 μm. The reason for the formation of such a big structure is the tendency of the nanoparticles to aggregate in ethanol before irradiation, which causes fusion of the nanoparticles.
    Matched MeSH terms: Colloids/chemistry
  4. 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
  5. Dai C, Zhou H, You X, Duan Y, Tu Y, Liu S, et al.
    Environ Sci Pollut Res Int, 2020 May;27(13):15188-15197.
    PMID: 32072419 DOI: 10.1007/s11356-020-08064-0
    Transport of environmental pollutants in groundwater systems can be greatly influenced by colloids. In this study, the cotransport of Pb2+ and silica (SiO2) colloids at different Pb2+ concentrations was systematically investigated by batch adsorption and saturated sand column experiments. Results showed that SiO2 colloids had low adsorption capacity for Pb2+ (less than 1% of the input) compared with sands. In saturated porous media, SiO2 colloids showed a high mobility; however, with the increase of Pb2+ concentration in the sand column, the mobility of SiO2 colloids gradually decreased. Notably, SiO2 colloids could facilitate Pb2+ transport, although they did not serve as effective carriers of Pb2+. Under the condition of low Pb2+ concentration, SiO2 colloids promoted the Pb2+ transport mainly through the way of "transport channel," while changing the porosity of the medium and masking medium adsorption sites were the main mechanisms of SiO2 colloid-facilitated Pb2+ transport under the condition of high Pb2+ concentration. The discovery of this non-adsorption effect of colloids would improve our understanding of colloid-facilitated Pb2+ transport in saturated porous media, which provided new insights into the role of colloids, especially colloids with weak Pb2+ adsorption capacity, in Pb2+ occurrence and transport in soil-groundwater systems.
    Matched MeSH terms: Colloids
  6. Khari M, Kassim KA, Adnan A
    ScientificWorldJournal, 2013;2013:734292.
    PMID: 24453900 DOI: 10.1155/2013/734292
    Grouped and single pile behavior differs owing to the impacts of the pile-to-pile interaction. Ultimate lateral resistance and lateral subgrade modulus within a pile group are known as the key parameters in the soil-pile interaction phenomenon. In this study, a series of experimental investigation was carried out on single and group pile subjected to monotonic lateral loadings. Experimental investigations were conducted on twelve model pile groups of configurations 1 × 2, 1 × 3, 2 × 2, 3 × 3, and 3 × 2 for embedded length-to-diameter ratio l/d = 32 into loose and dense sand, spacing from 3 to 6 pile diameter, in parallel and series arrangement. The tests were performed in dry sand from Johor Bahru, Malaysia. To reconstruct the sand samples, the new designed apparatus, Mobile Pluviator, was adopted. The ultimate lateral load is increased 53% in increasing of s/d from 3 to 6 owing to effects of sand relative density. An increasing of the number of piles in-group decreases the group efficiency owing to the increasing of overlapped stress zones and active wedges. A ratio of s/d more than 6d is large enough to eliminate the pile-to-pile interaction and the group effects. It may be more in the loose sand.
    Matched MeSH terms: Colloids/chemistry*
  7. Yeap SP, Ahmad AL, Ooi BS, Lim J
    Langmuir, 2012 Oct 23;28(42):14878-91.
    PMID: 23025323 DOI: 10.1021/la303169g
    A detailed study on the conflicting role that colloid stability plays in magnetophoresis is presented. Magnetic iron oxide particles (MIOPs) that were sterically stabilized via surface modification with poly(sodium 4-styrene sulfonate) of different molecular weights (i.e., 70 and 1000 kDa) were employed as our model system. Both sedimentation kinetics and quartz crystal microbalance with dissipation (QCM-D) measurements suggested that PSS 70 kDa is a better stabilizer as compared to PSS 1000 kDa. This observation is mostly attributed to the bridging flocculation of PSS 1000 kDa decorated MIOPs originated from the extended polymeric conformation layer. Later, a lab-scale high gradient magnetic separation (HGMS) device was designed to study the magnetophoretic collection of MIOPs. Our experimental results revealed that the more colloidally stable the MIOP suspension is, the harder it is to be magnetically isolated by HGMS. At 50 mg/L, naked MIOPs without coating can be easily captured by HGMS at separation efficiency up to 96.9 ± 2.6%. However, the degree of separation dropped quite drastically to 83.1 ± 1.2% and 67.7 ± 4.6%, for MIOPs with PSS 1000k and PSS 70k coating, respectively. This observation clearly implies that polyelectrolyte coating that was usually employed to electrosterically stabilize a colloidal system in turn compromises the magnetic isolation efficiency. By artificially destroying the colloidal stability of the MIOPs with ionic strength increment, the ability for HGMS to recover the most stable suspension (i.e., PSS 70k-coated MIOPs) increased to >86% at 100 mM monovalent ion (Na(+)) or at 10 mM divalent ion (Ca(2+)). This observation has verified the conflicting role of colloidal stability in magnetophoretic separation.
    Matched MeSH terms: Colloids/chemistry
  8. Gannasin SP, Adzahan NM, Hamzah MY, Mustafa S, Muhammad K
    Food Chem, 2015 Sep 1;182:292-301.
    PMID: 25842340 DOI: 10.1016/j.foodchem.2015.03.010
    Tamarillo (Solanum betaceum Cav.) is an underutilised fruit in Malaysia. The fruit, however, contains good proportions of soluble fibre, protein, starch, anthocyanins and carotenoids. Amongst the fruits, only tamarillo mesocarp contains both polar (anthocyanins) and non-polar (carotenoids) pigments. The ability to retain both polar and non-polar pigments in the mesocarp could be related to the unique properties of its hydrocolloids. To understand the pigment-hydrocolloid interaction in the fruit, information on the physicochemical characteristics of the hydrocolloids is required. Therefore, hydrocolloids from the anthocyanin-rich seed mucilage fraction of the tamarillo and its carotenoid-rich pulp fraction were extracted and characterised. Water and 1% citric acid were used to extract the seed mucilage hydrocolloid while 72% ethanol and 20mM HEPES buffer were used for pulp hydrocolloid extraction. Seed mucilage hydrocolloid was primarily composed of arabinogalactan protein-associated pectin whereas pulp hydrocolloid was composed of hemicellulosic polysaccharides with some naturally interacting proteins and neutral polysaccharides.
    Matched MeSH terms: Colloids/chemistry*
  9. Yu Z, Liu J, Tan CSY, Scherman OA, Abell C
    Angew Chem Int Ed Engl, 2018 03 12;57(12):3079-3083.
    PMID: 29377541 DOI: 10.1002/anie.201711522
    The ability to construct self-healing scaffolds that are injectable and capable of forming a designed morphology offers the possibility to engineer sustainable materials. Herein, we introduce supramolecular nested microbeads that can be used as building blocks to construct macroscopic self-healing scaffolds. The core-shell microbeads remain in an "inert" state owing to the isolation of a pair of complementary polymers in a form that can be stored as an aqueous suspension. An annealing process after injection effectively induces the re-construction of the microbead units, leading to supramolecular gelation in a preconfigured shape. The resulting macroscopic scaffold is dynamically stable, displaying self-recovery in a self-healing electronic conductor. This strategy of using the supramolecular assembled nested microbeads as building blocks represents an alternative to injectable hydrogel systems, and shows promise in the field of structural biomaterials and flexible electronics.
    Matched MeSH terms: Colloids
  10. Leong SS, Ahmad Z, Low SC, Camacho J, Faraudo J, Lim J
    Langmuir, 2020 07 21;36(28):8033-8055.
    PMID: 32551702 DOI: 10.1021/acs.langmuir.0c00839
    The migration process of magnetic nanoparticles and colloids in solution under the influence of magnetic field gradients, which is also known as magnetophoresis, is an essential step in the separation technology used in various biomedical and engineering applications. Many works have demonstrated that in specific situations, separation can be performed easily with the weak magnetic field gradients created by permanent magnets, a process known as low-gradient magnetic separation (LGMS). Due to the level of complexity involved, it is not possible to understand the observed kinetics of LGMS within the classical view of magnetophoresis. Our experimental and theoretical investigations in the last years unravelled the existence of two novel physical effects that speed up the magnetophoresis kinetics and explain the observed feasibility of LGMS. Those two effects are (i) cooperative magnetophoresis (due to the cooperative motion of strongly interacting particles) and (ii) magnetophoresis-induced convection (fluid dynamics instability originating from inhomogeneous magnetic gradients). In this feature article, we present a unified view of magnetophoresis based on the extensive research done on these effects. We present the physical basis of each effect and also propose a classification of magnetophoresis into four distinct regimes. This classification is based on the range of values of two dimensionless quantities, namely, aggregation parameter N* and magnetic Grashof number Grm, which include all of the dependency of LGMS on various physical parameters (such as particle properties, thermodynamic parameters, fluid properties, and magnetic field properties). This analysis provides a holistic view of the classification of transport mechanisms in LGMS, which could be particularly useful in the design of magnetic separators for engineering applications.
    Matched MeSH terms: Colloids
  11. Noorlaila A, Hasanah HN, Yusoff A, Sarijo SH, Asmeda R
    J Food Sci Technol, 2017 Oct;54(11):3532-3542.
    PMID: 29051648 DOI: 10.1007/s13197-017-2810-6
    The effects of xanthan gum (XG) and hydroxypropyl methylcellulose (HPMC) in sponge cakes were studied. Hydrocolloids enhanced the thickening effect in batter that affected the textural attributes of sponge cakes. During storage, the structural changes in XG-cake resulted in higher hardness compared to HPMC-cake. Similar to XG, HPMC also contributed moistness to cake. The moisture loss of cake containing XG was slower than HPMC-cake. FTIR study showed absorption of OH at region of 3600-2900 cm-1 that explained the strong interaction of water in cake containing XG compared to other cake formulations.
    Matched MeSH terms: Colloids
  12. 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
  13. Yunus NA, Nili H, Green NG
    Electrophoresis, 2013 Apr;34(7):969-78.
    PMID: 23436439 DOI: 10.1002/elps.201200466
    Dielectrophoresis is the movement of particles in nonuniform electric fields and has been of interest for application to manipulation and separation at and below the microscale. This technique has the advantages of being noninvasive, nondestructive, and noncontact, with the movement of particle achieved by means of electric fields generated by miniaturized electrodes and microfluidic systems. Although the majority of applications have been above the microscale, there is increasing interest in application to colloidal particles around a micron and smaller. This paper begins with a review of colloidal and nanoscale dielectrophoresis with specific attention paid to separation applications. An innovative design of integrated microelectrode array and its application to flow-through, continuous separation of colloidal particles is then presented. The details of the angled chevron microelectrode array and the test microfluidic system are then discussed. The variation in device operation with applied signal voltage is presented and discussed in terms of separation efficiency, demonstrating 99.9% separation of a mixture of colloidal latex spheres.
    Matched MeSH terms: Colloids/isolation & purification*; Colloids/chemistry
  14. 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*
  15. 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
  16. Shehab ZN, Jamil NR, Aris AZ
    Sci Rep, 2020 11 23;10(1):20360.
    PMID: 33230250 DOI: 10.1038/s41598-020-77454-8
    Phase distribution of emerging organic contaminants is highly influential in their presence, fate and transport in surface water. Therefore, it is crucial to determine their state, partitioning behaviour and tendencies in water environments. In this study, Bisphenol A was investigated in both colloidal and soluble phases in water. BPA concentrations ranged between 1.13 and 5.52 ng L-1 in the soluble phase and n.d-2.06 ng L-1 in the colloidal phase, respectively. BPA was dominant in the soluble phase, however, the colloidal contribution ranged between 0 and 24% which implied that colloids can play a significant role in controlling BPA's transportation in water. Urban and industrial areas were the main sources of BPA while forest areas displayed lower levels outside the populated domains. pH levels were between 6.3 and 7.4 which might have affected BPA's solubility in water to some extent. The particle size distribution showed that the majority of the particles in river samples were smaller than 1.8 µm in diameter with a small presence of nanoparticles. Zeta potential varied between - 25 and - 18 mV, and these negative values suggested instability of particles. Furthermore, BPA was positively correlated with BOD, COD and NH3-N which might indicate that these organic compounds were released concurrently with BPA. RQ assessment showed low levels of risk towards algae and fish in the study area.
    Matched MeSH terms: Colloids
  17. Ishamri Ismail, Nur Husna Mohd Fauzi, Mastura Zahidi Baki, Ho, Lee Hoon
    MyJurnal
    This study was carried out to evaluate the effects of different drying methods (sun drying, cabinet
    drying and convection oven) and hydrocolloids (carrageenan and alginate) on physicochemical
    properties of semi-dried catfish jerky. The concentration of hydrocolloids used was 1% and 2%.
    Samples without the addition of hydrocolloid served as the control group. The water activity of semidried catfish jerky decreased with the addition of hydrocolloids. For colour properties, lightness (L*)
    value of semi-dried catfish jerky increased with the increased concentration of hydrocolloids. The
    addition of 2% alginate (2%A) and 2% carrageenan (2%C) showed higher lightness (L*) than the
    controlled group for all drying methods, except for sun drying with carrageenan. Both carrageenan and
    alginate added into semi-dried catfish jerky increased the processing yields. The addition of 2%
    carrageenan (2%C) and 1% alginate (1%A) improved the product yields for all drying methods. This
    paper argues that the application of cabinet dryer gives better shelf stability due to the lower range of
    water activity than other drying methods while preserving colour quality and product yields.
    Matched MeSH terms: Colloids
  18. Alrosan M, Tan TC, Easa AM, Gammoh S, Alu'datt MH
    PMID: 33455424 DOI: 10.1080/10408398.2021.1871589
    The application of protein-protein interaction (PPI) has been widely used in various industries, such as food, nutraceutical, and pharmaceutical. A deeper understanding of PPI is needed, and the molecular forces governing proteins and their interaction must be explained. The design of new structures with improved functional properties, e.g., solubility, emulsion, and gelation, has been fueled by the development of structural and colloidal building blocks. In this review, the molecular forces of protein structures are discussed, followed by the relationship between molecular force and structure, ways of a bind of proteins together in solution or at the interface, and functional properties. A more detailed look is thus taken at the relationship between the various influencing factors on molecular forces involved in PPI. These factors include protein properties, such as types, concentration, and mixing ratio, and solvent conditions, such as ionic strength and pH. This review also summarizes methods tha1t are capable of identifying molecular forces in protein and PPI, as well as characterizing protein structure.
    Matched MeSH terms: Colloids
  19. Shukri, W.H.Z., Hamzah, E.N.H., Halim, N.R.A., Isa, M.I.N., Sarbon, N.M.
    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
  20. Amir, I.Z., Sharon, W.X.R., Syafiq, A.
    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
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