Displaying publications 21 - 40 of 61 in total

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  1. Ullah F, Othman MB, Javed F, Ahmad Z, Akil HM, Rasib SZ
    Int J Biol Macromol, 2016 Feb;83:376-84.
    PMID: 26597568 DOI: 10.1016/j.ijbiomac.2015.11.040
    A new approach to design multifunctional chitosan based nanohydrogel with enhanced glucose sensitivity, stability, drug loading and release profile are reported. Two approaches were followed for functionalization of chitosan based nanohydrogel with 3-APBA via EDC and 3-APTES. The effective functionalization, structure and morphology of Chitosan based IPN respectively were confirmed by FTIR, SEM and AFM. At physiological conditions, the glucose-induced volume phase transition and release profile of the model drug Alizarin Red with 1,2-diol structure (comparative to insulin as a drug as well as a dye for bio separation) were studied at various glucose concentrations, pH and ionic strengths. The results suggested a new concept for diabetes treatment and diols sensitivity in view of their potential hi-tech applications in self-regulated on-off response to the treatment (drug delivery and bio separation concurrently).
    Matched MeSH terms: Osmolar Concentration
  2. Lasekan O
    J Sci Food Agric, 2013 Mar 30;93(5):1055-61.
    PMID: 22936608 DOI: 10.1002/jsfa.5846
    Volatile compounds play a key role in determining the sensory appreciation of vegetable oils. In this study a systematic evaluation of odorants responsible for the characteristic flavour of roasted tigernut oil was carried out.
    Matched MeSH terms: Osmolar Concentration
  3. Ulianas A, Heng LY, Abu Hanifah S, Ling TL
    Sensors (Basel), 2012;12(5):5445-60.
    PMID: 22778594 DOI: 10.3390/s120505445
    An electrochemical microbiosensor for DNA has been fabricated based on new acrylic microspheres modified with reactive N-acryloxysuccinimide (NAS) functional groups. Hydrophobic poly(n-butylacrylate-N-acryloxysuccinimide) microspheres were synthesized in an emulsion form with a simple one-step photopolymerization technique. Aminated DNA probe was attached to the succinimde functional group of the acrylic microspheres via covalent bonding. The hybridization of the immobilized DNA probe with the complementary DNA was studied by differential pulse voltametry using anthraquninone-2-sulfonic acid monohydrate sodium salt (AQMS) as the electroactive hybridization label. The influences of many factors such as duration of DNA probe immobilization and hybridization, pH, type of ions, buffer concentrations, ionic strength, operational temperature and non-complementary DNA on the biosensor performance were evaluated. Under optimized conditions, the DNA microbiosensor demonstrated a linear response range to target DNA over a wide concentration range of 1.0 × 10(-16) and 1.0 × 10(-8) M with a lower limit of detection (LOD) of 9.46 × 10(-17) M (R(2) = 0.97). This DNA microbiosensor showed good reproducibility with 2.84% RSD (relative standard deviation) (n = 3). Application of the NAS-modified acrylic microspheres in the construction of DNA microbiosensor had improved the overall analytical performance of the resultant DNA microbiosensor when compared with other reported DNA biosensors using other nano-materials for membranes and microspheres as DNA immobilization matrices.
    Matched MeSH terms: Osmolar Concentration
  4. Samsudin A, Mimiwati Z, Soong T, Fauzi MS, Zabri K
    Eye (Lond), 2010 Jan;24(1):70-3.
    PMID: 19229270 DOI: 10.1038/eye.2009.33
    To study the effect of haemodialysis on intraocular pressure (IOP) of patients at the University Malaya Medical Centre, Kuala Lumpur, and the influence of anterior chamber angles, surgery, and diabetes on the change in IOP after haemodialysis.
    Matched MeSH terms: Osmolar Concentration
  5. 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: Osmolar Concentration
  6. Shah I, Adnan R, Wan Ngah WS, Mohamed N
    PLoS One, 2015;10(4):e0122603.
    PMID: 25849291 DOI: 10.1371/journal.pone.0122603
    In this study, iron impregnated activated carbon (FeAC) was synthesized following an oxidation and iron impregnation of activated carbon (AC). Both the AC and FeAC were characterized by pHZPC and FTIR spectroscopy. The removal of Methylene Blue (MB) by AC and FeAC was examined under various experimental conditions. The FeAC showed up to 95% (higher than AC) MB removal in the pH range of 7-10. Although the reaction kinetics was pseudo-second order, the overall rate was controlled by a number of processes such as film diffusion, pore diffusion and intraparticle diffusion. The activation energy values for the MB uptake by AC and FeAC (21.79 and 14.82 kJ/mol, respectively) revealed a physisorption process. In the regeneration study, FeAC has shown consistently ≥ 90% MB removal even up to 10 repeated cycles. The reusable characteristic of the spent FeAC improved the practical use of activated carbon and can be a breakthrough for continuous flow system applications where it can work effectively without any significant reduction in its performance.
    Matched MeSH terms: Osmolar Concentration
  7. Lam SK, Harvey S
    PMID: 1970531
    1. Anaesthesia caused marked decreases in the plasma concentrations of triiodothyronine (T3) and thyroxine (T4) and in the body temperature of young fowl. 2. Exogenous T4 or a thyroid hormone secretagogue (somatostatin antiserum), increased endogenous T3 and T4 concentrations and body temperature in conscious birds and prevented the body temperature decline in anaesthetized fowl. 3. These results provide further evidence for a role of T3 and T4 in temperature regulation in birds, particularly during anaesthesia.
    Matched MeSH terms: Osmolar Concentration
  8. Cheah SH, Ch'ng SL, Husain R, Duncan MT
    Br J Nutr, 1990 Mar;63(2):329-37.
    PMID: 2334668
    Urine analysis was conducted on male Muslims before, during and after Ramadan. Various changes in urine volume, osmolality, total solute, sodium, potassium, titratable acidity and urea in response to altered feeding and activity regimens were found. There were no detectable levels of ketones, protein, glucose, urobilinogen and haemoglobin. It was concluded that the body adapted to fasting during Ramadan and that there were no adverse effects on renal function.
    Matched MeSH terms: Osmolar Concentration
  9. Lee S, Ko IW, Yoon IH, Kim DW, Kim KW
    Environ Geochem Health, 2019 Feb;41(1):469-480.
    PMID: 29574658 DOI: 10.1007/s10653-018-0099-7
    Colloid mobilization is a significant process governing colloid-associated transport of heavy metals in subsurface environments. It has been studied for the last three decades to understand this process. However, colloid mobilization and heavy metal transport in soil solutions have rarely been studied using soils in South Korea. We investigated the colloid mobilization in a variety of flow rates during sampling soil solutions in sand columns. The colloid concentrations were increased at low flow rates and in saturated regimes. Colloid concentrations increased 1000-fold higher at pH 9.2 than at pH 7.3 in the absence of 10 mM NaCl solution. In addition, those were fourfold higher in the absence than in the presence of the NaCl solution at pH 9.2. It was suggested that the mobility of colloids should be enhanced in porous media under the basic conditions and the low ionic strength. In real field soils, the concentrations of As, Cr, and Pb in soil solutions increased with the increase in colloid concentrations at initial momentarily changed soil water pressure, whereas the concentrations of Cd, Cu, Fe, Ni, Al, and Co lagged behind the colloid release. Therefore, physicochemical changes and heavy metal characteristics have important implications for colloid-facilitated transport during sampling soil solutions.
    Matched MeSH terms: Osmolar Concentration
  10. Hassan RA, Heng LY, Tan LL
    Sci Rep, 2019 04 23;9(1):6379.
    PMID: 31015498 DOI: 10.1038/s41598-019-42757-y
    A novel disposable electrochemical biosensor based on immobilized calf thymus double-stranded DNA (dsDNA) on the carbon-based screen-printed electrode (SPE) is developed for rapid biorecognition of carrageenan by using methylene blue (MB) redox indicator. The biosensor protocol for the detection of carrageenan is based on the concept of competitive binding of positively charged MB to the negatively charged dsDNA and carrageenan. The decrement in the MB cathodic peak current (ipc) signal as a result of the released MB from the immobilized dsDNA, and attracted to the carrageenan can be monitored via differential pulse voltammetry (DPV). The biosensor showed high sensitivity and selectivity to carrageenan at low concentration without interference from other polyanions such as alginate, gum arabic and starch. Calibration of the biosensor with carrageenan exhibited an excellent linear dependence from 1-10 mg L-1 (R2 = 0.98) with a detection limit of 0.08 mg L-1. The DNA-based carrageenan biosensor showed satisfactory reproducibility with 5.6-6.9% (n = 3) relative standard deviations (RSD), and possessing several advantages such as simplicity, fast and direct application to real sample analysis without any prior extensive sample treatments, particularly for seaweeds and food analyses.
    Matched MeSH terms: Osmolar Concentration
  11. Chan YF
    Med J Malaya, 1972 Mar;26(3):211-4.
    PMID: 5031019
    Matched MeSH terms: Osmolar Concentration
  12. Umbreen N, Sohni S, Ahmad I, Khattak NU, Gul K
    J Colloid Interface Sci, 2018 Oct 01;527:356-367.
    PMID: 29843021 DOI: 10.1016/j.jcis.2018.05.010
    Herein, self-assembled three-dimensional reduced graphene oxide (RGO)-based hydrogels were synthesized and characterized in detail. A thorough investigation on the uptake of three widely used pharmaceutical drugs, viz. Naproxen (NPX), Ibuprofen (IBP) and Diclofenac (DFC) was carried out from aqueous solutions. To ensure the sustainability of developed hydrogel assembly, practically important parameters such as desorption, recyclability and applicability to real samples were also evaluated. Using the developed 3D hydrogels as adsorptive platforms, excellent decontamination for the above mentioned persistent pharmaceutical drugs was achieved in acidic pH with a removal efficiency in the range of 70-80%. These hydrogels showed fast adsorption kinetics and experimental findings were fitted to different kinetic models, such as pseudo-first order, pseudo-second order, intra-particle and the Elovich models in an attempt to better understand the adsorption kinetics. Furthermore, equilibrium adsorption data was fitted to the Langmuir and Freundlich models, where relatively higher R2 values obtained in case of former one suggested that monolayer adsorption played an important part in drug uptake. Thermodynamic aspects were also studied and negative ΔG0 values obtained indicated the spontaneous nature of adsorption process. The study was also extended to check practical utility of as-prepared hydrogels by spiking real aqueous samples with drug solution, where high % recoveries obtained for NPX, IBP and DFC were of particular importance with regard to prospective application in wastewater treatment systems. We advocate RGO-based hydrogels as environmentally benign, readily recoverable/recyclable material with excellent adsorption capacity for application in wastewater purification.
    Matched MeSH terms: Osmolar Concentration
  13. 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: Osmolar Concentration
  14. Yakubu R, Peh KK, Tan YT
    Drug Dev Ind Pharm, 2009 Dec;35(12):1430-8.
    PMID: 19929202 DOI: 10.3109/03639040902988566
    The purpose of this study was to design a 24-hour controlled porosity osmotic pump system that utilizes polyvinyl pyrrolidone (PVP) as an osmotic-suspending/release retarding agent of drugs.
    Matched MeSH terms: Osmolar Concentration
  15. Tan PY, Tan TB, Chang HW, Tey BT, Chan ES, Lai OM, et al.
    J Agric Food Chem, 2017 Dec 06;65(48):10651-10657.
    PMID: 29124932 DOI: 10.1021/acs.jafc.7b03521
    Considering the health benefits of tocotrienols, continuous works have been done on the encapsulation and delivery of these compounds. In this study, we encapsulated tocotrienols in chitosan-alginate microcapsules and evaluated their release profile. Generally, these tocotrienols microcapsules (TM) displayed high thermal stability. When subjected to pH adjustments (pH 1-9), we observed that the release of tocotrienols was the highest (33.78 ± 0.18%) under basic conditions. The TM were also unstable against the effect of ionic strength, with a high release (70.73 ± 0.04%) of tocotrienols even at a low sodium chloride concentration (50 mM). As for the individual isomers, δ-tocotrienol was the most sensitive to pH and ionic strength. In contrast, β-/γ-tocotrienols were the most ionic-stable isomers but more responsive toward thermal treatment. Simulated gastrointestinal model showed that the chitosan-alginate-based TM could be used to retain tocotrienols in the gastric and subsequently release them in the intestines for possible absorption.
    Matched MeSH terms: Osmolar Concentration
  16. Monjezi R, Tey BT, Sieo CC, Tan WS
    PMID: 20538529 DOI: 10.1016/j.jchromb.2010.05.028
    M13 is a non-lytic filamentous bacteriophage (phage). It has been used widely in phage display technology for displaying foreign peptides, and also for studying macromolecule structures and interactions. Traditionally, this phage has been purified by cesium chloride (CsCl) density gradient ultracentrifugation which is highly laborious and time consuming. In the present study, a simple, rapid and efficient method for the purification of M13 based on anion exchange chromatography was established. A pre-packed SepFast Super Q column connected to a fast protein liquid chromatography (FPLC) system was employed to capture released phages in clarified Escherichia coli fermented broth. An average yield of 74% was obtained from a packed bed mode elution using citrate buffer (pH 4), containing 1.5 M NaCl at 1 ml/min flow rate. The purification process was shortened substantially to less than 2 h from 18 h in the conventional ultracentrifugation method. SDS-PAGE revealed that the purity of particles was comparable to that of CsCl gradient density ultracentrifugation method. Plaque forming assay showed that the purified phages were still infectious.
    Matched MeSH terms: Osmolar Concentration
  17. Md Noor J, Hawari R, Mokhtar MF, Yussof SJ, Chew N, Norzan NA, et al.
    Int J Emerg Med, 2020 Feb 07;13(1):6.
    PMID: 32028888 DOI: 10.1186/s12245-020-0264-5
    INTRODUCTION: Methanol poisoning usually occurs in a cluster and initial diagnosis can be challenging. Mortality is high without immediate interventions. This paper describes a methanol poisoning outbreak and difficulties in managing a large number of patients with limited resources.

    METHODOLOGY: A retrospective analysis of a methanol poisoning outbreak in September 2018 was performed, describing patients who presented to a major tertiary referral centre.

    RESULT: A total of 31 patients were received over the period of 9 days. Thirty of them were males with a mean age of 32 years old. They were mostly foreigners. From the 31 patients, 19.3% were dead on arrival, 3.2% died in the emergency department and 38.7% survived and discharged. The overall mortality rate was 61.3%. Out of the 12 patients who survived, two patients had toxic optic neuropathy, and one patient had uveitis. The rest of the survivors did not have any long-term complications. Osmolar gap and lactate had strong correlations with patient's mortality. Serum pH, bicarbonate, lactate, potassium, anion gap, osmolar gap and measured serum osmolarity between the alive and dead patients were significant. Post-mortem findings of the brain were unremarkable.

    CONCLUSION: The mortality rate was higher, and the morbidity includes permanent visual impairment and severe neurological sequelae. Language barrier, severity of illness, late presentation, unavailability of intravenous ethanol and fomipezole and delayed dialysis may have been the contributing factors. Patient was managed based on clinical presentation. Laboratory parameters showed difference in median between group that survived and succumbed for pH, serum bicarbonate, lactate, potassium and osmolar and anion gap. Management of methanol toxicity outbreak in resource-limited area will benefit from a well-designed guideline that is adaptable to the locality.

    Matched MeSH terms: Osmolar Concentration
  18. Hajian R, Mehrayin Z, Mohagheghian M, Zafari M, Hosseini P, Shams N
    Mater Sci Eng C Mater Biol Appl, 2015 Apr;49:769-775.
    PMID: 25687007 DOI: 10.1016/j.msec.2015.01.072
    In this study, an electrochemical sensor was fabricated based on gold nanoparticles/ ethylenediamine/ multi-wall carbon-nanotubes modified gold electrode (AuNPs/en/MWCNTs/AuE) for determination of valrubicin in biological samples. Valrubicin was effectively accumulated on the surface of AuNPs/en/MWCNTs/AuE and produced a pair of redox peaks at around 0.662 and 0.578V (vs. Ag/AgCl) in citrate buffer (pH4.0). The electrochemical parameters including pH, buffer, ionic strength, scan rate and size of AuNPs have been optimized. There was a good linear correlation between cathodic peak current and concentration of valrubicin in the range of 0.5 to 80.0μmolL(-1) with the detection limit of 0.018μmolL(-1) in citrate buffer (pH4.0) and 0.1molL(-1) KCl. Finally, the constructed sensor was successfully applied for determination of valrubicin in human urine and blood serum. In further studies, the different sequences of single stranded DNA probes have been immobilized on the surface of AuNPs decorated on MWCNTs to study the interaction of oligonucleotides with valrubicin.
    Matched MeSH terms: Osmolar Concentration
  19. Che HX, Yeap SP, Osman MS, Ahmad AL, Lim J
    ACS Appl Mater Interfaces, 2014 Oct 8;6(19):16508-18.
    PMID: 25198872 DOI: 10.1021/am5050949
    The synthesis of nanocomposite with controlled surface morphology plays a key role for pollutant removal from aqueous environments. The influence of the molecular size of the polyelectrolyte in synthesizing silica-iron oxide core-shell nanocomposite with open shell structure was investigated by using dynamic light scattering, atomic force microscopy, and quartz crystal microbalance with dissipation (QCM-D). Here, poly(diallydimethylammonium chloride) (PDDA) was used to promote the attachment of iron oxide nanoparticles (IONPs) onto the silica surface to assemble a nanocomposite with magnetic and catalytic bifunctionality. High molecular weight PDDA tended to adsorb on silica colloid, forming a more extended conformation layer than low molecular weight PDDA. Subsequent attachment of IONPs onto this extended PDDA layer was more randomly distributed, forming isolated islands with open space between them. By taking amoxicillin, an antibiotic commonly found in pharmaceutical waste, as the model system, better removal was observed for silica-iron oxide nanocomposite with a more extended open shell structure.
    Matched MeSH terms: Osmolar Concentration
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