MyMedR

Displaying publications 21 - 40 of 137 in total

Abstract:

Sort:

The effect of aeration and non-aeration time on simultaneous organic, nitrogen and phosphorus removal using an intermittent aeration membrane bioreactor

Ujang Z, Salim MR, Khor SL

Water Sci Technol, 2002;46(9):193-200.
PMID: 12448469

A laboratory-scale membrane bioreactor (MBR) was fed with synthetic wastewater to investigate the possibility of simultaneous removal of organic, nitrogen and phosphorus by intermittent aeration. The MBR consists of two compartments using a microfiltration membrane with 0.2 microm pore size and a surface area of 0.35 m2. Hydraulic retention time was set at 24 hours and solid retention time 25 days. MLSS concentration in the reactor was in the range of 2,500-3,800 mg/L. The MLSS internal recycling ratio was maintained at 100% influent flow rate. Intermittent aeration was applied in this study to provide an aerobic-anaerobic cycle. Three stages of operations were conducted to investigate the effect of aeration and non-aeration on simultaneous organic and nutrient removal. In Stage 1, time cycles of aeration and non-aeration were set at 90/150 min and 150/90 min in the first and second compartment, the removal efficiency was 97%, 94% and 70% for COD, nitrogen and phosphorus respectively. In Stage 2, time cycles of aeration and non-aeration were set at 60/120 min and 120/60 min in the first and second compartment, the removal efficiency was 97%, 96% and 71% for COD, nitrogen and phosphorus respectively. In Stage 3, time cycles of aeration and non-aeration were set at 120/120 min and 120/120 min in compartment 1 and 2, the removal efficiency was 98%, 96% and 78% for COD, nitrogen and phosphorus respectively. Results show that longer non-aeration time in the second compartment provided better performances of biological phosphorus removal.

Matched MeSH terms: Organic Chemicals/isolation & purification
Model studies on granular activated carbon adsorption in fixed bed filtration

Jusoh AB, Noor MJ, Plow SB

Water Sci Technol, 2002;46(9):127-35.
PMID: 12448461

The removal of natural organic matter (NOM) using a continuous flow fixed bed granular activated carbon (GAC) column was studied and the results were then fitted with the Adams-Bohart, Bed-Depth-Service-Time and Clarks models. The GAC, KI-6070 and KI-8085 used in the study had external surface areas of 277 m2/g and 547 m2/g, respectively. Adsorption of NOM by the GAC was complex and involved more than one rate-limiting step. The critical bed depths for KI-6070 and KI-8085 were 0.24 m and 0.3 m, respectively. The Clark model was more effective in simulating the absorbent breakthrough process as compared to the Adams-Bohart model. The lower empty bed contact time (EBCT) i.e. 15 minutes gave a better fit to the Clark Model as compared to EBCT of 20 and 30 minutes.

Matched MeSH terms: Organic Chemicals/isolation & purification
Phytosterols-induced viscoelasticity of oleogels prepared by using monoglycerides

Bin Sintang MD, Danthine S, Brown A, Van de Walle D, Patel AR, Tavernier I, et al.

Food Res Int, 2017 10;100(Pt 1):832-840.
PMID: 28873756 DOI: 10.1016/j.foodres.2017.07.079

Monoglycerides (MGs) and phytosterols (PS) are known to form firm oleogels with liquid oil. However, the oleogels are prone to undergo polymorphic transition over time that lead to crystals' aggregation thus, compromises physical properties. Thus, we combined MGs with PS to control the crystallization and modify the morphology of the combination oleogels, as both components are reported to interact together. The oleogels were prepared at different ratio combinations and characterized in their rheological, thermal, morphology, and diffraction properties. The results showed that the 8:2 MGP:PS exhibited higher storage modulus (G') than the MGP mono-component. The combination oleogels exhibited effects on the crystallization and polymorphic transition. Consequently, the effects led to change in the morphology of the combination oleogels which was visualized using optical and electron microscope. The resultant effect on the morphology is associated with crystal defect. Due to observable crystals of MGP and PS, it is speculated that the combination oleogels formed a mixed crystal system. This was confirmed with diffraction analysis in which the corresponding peaks from MGP and PS were observed in the combination oleogels. However, the 8:2 oleogel exhibited additional peak at 35.41Å. Ultimately, the 8:2 was the optimum combination observed in our study. Interestingly, this combination is inspired by nature as sterols (phytosterols) are natural component of lipid membrane whilst MGP has properties similar to phospholipids. Hence, the results of our study not only beneficial for oil structuring, but also for the fields of biophysical and pharmaceutical.

Matched MeSH terms: Organic Chemicals/chemistry
Electrical behaviour of MEH-PPV based diode and transistor

Reshak AH, Shahimin MM, Juhari N, Suppiah S

Prog Biophys Mol Biol, 2013 Nov;113(2):289-94.
PMID: 24080185 DOI: 10.1016/j.pbiomolbio.2013.09.002

The potential of organic semiconductor based devices for light generation is demonstrated by the commercialisation of display technologies using organic light emitting diode (OLED). In OLED, organic materials plays an important role of emitting light once the current is passed through. However OLED have drawbacks whereby it suffers from photon loss and exciton quenching. Organic light emitting transistor (OLET) emerged as a new technology to compensate the efficiency and brightness loss encountered in OLED. The structure has combinational capability to switch the electronic signal such as the field effect transistor (FET) as well as to generate light. Different colours of light could be generated by using different types of organic material. The light emission could also be tuned and scanned in OLET. The studies carried out in this paper focuses on investigation of fabricated MEH-PPV based OLED and also OLET via current voltage characteristics. These studies will continue with a view to develop an optimised MEH-PPV based OLET.

Matched MeSH terms: Organic Chemicals/chemistry*
Fulltext Comparative metabolomics of Phialemonium curvatum as an omnipotent fungus cultivated on crude palm oil versus glucose

Zamani AI, Barig S, Ibrahim S, Mohd Yusof H, Ibrahim J, Low JYS, et al.

Microb Cell Fact, 2020 Sep 09;19(1):179.
PMID: 32907579 DOI: 10.1186/s12934-020-01434-w

BACKGROUND: Sugars and triglycerides are common carbon sources for microorganisms. Nonetheless, a systematic comparative interpretation of metabolic changes upon vegetable oil or glucose as sole carbon source is still lacking. Selected fungi that can grow in acidic mineral salt media (MSM) with vegetable oil had been identified recently. Hence, this study aimed to investigate the overall metabolite changes of an omnipotent fungus and to reveal changes at central carbon metabolism corresponding to both carbon sources.
RESULTS: Targeted and non-targeted metabolomics for both polar and semi-polar metabolites of Phialemonium curvatum AWO2 (DSM 23903) cultivated in MSM with palm oil (MSM-P) or glucose (MSM-G) as carbon sources were obtained. Targeted metabolomics on central carbon metabolism of tricarboxylic acid (TCA) cycle and glyoxylate cycle were analysed using LC-MS/MS-TripleQ and GC-MS, while untargeted metabolite profiling was performed using LC-MS/MS-QTOF followed by multivariate analysis. Targeted metabolomics analysis showed that glyoxylate pathway and TCA cycle were recruited at central carbon metabolism for triglyceride and glucose catabolism, respectively. Significant differences in organic acids concentration of about 4- to 8-fold were observed for citric acid, succinic acid, malic acid, and oxaloacetic acid. Correlation of organic acids concentration and key enzymes involved in the central carbon metabolism was further determined by enzymatic assays. On the other hand, the untargeted profiling revealed seven metabolites undergoing significant changes between MSM-P and MSM-G cultures.
CONCLUSIONS: Overall, this study has provided insights on the understanding on the effect of triglycerides and sugar as carbon source in fungi global metabolic pathway, which might become important for future optimization of carbon flux engineering in fungi to improve organic acids production when vegetable oil is applied as the sole carbon source.

Matched MeSH terms: Organic Chemicals/metabolism*
Fulltext A solution-based temperature sensor using the organic compound CuTsPc

Abdullah SM, Ahmad Z, Sulaiman K

Sensors (Basel), 2014;14(6):9878-88.
PMID: 24901979 DOI: 10.3390/s140609878

An electrochemical cell using an organic compound, copper (II) phthalocyanine-tetrasulfonic acid tetrasodium salt (CuTsPc,) has been fabricated and investigated as a solution-based temperature sensor. The capacitance and resistance of the ITO/CuTsPc solution/ITO chemical cell has been characterized as a function of temperature in the temperature range of 25-80 °C. A linear response with minimal hysteresis is observed. The fabricated temperature sensor has shown high consistency and sensitive response towards a specific range of temperature values.

Matched MeSH terms: Organic Chemicals
Molecularly imprinted polymers as optical sensing receptors: correlation between analytical signals and binding isotherms

Ng SM, Narayanaswamy R

Anal Chim Acta, 2011 Oct 10;703(2):226-33.
PMID: 21889638 DOI: 10.1016/j.aca.2011.07.032

Despite the increasing number of usage of molecularly imprinted polymers (MIPs) in optical sensor application, the correlation between the analytical signals and the binding isotherms has yet to be fully understood. This work investigates the relationship between the signals generated from MIPs sensors to its respective binding affinity variables generated using binding isotherm models. Two different systems based on the imprinting of metal ion and organic compound have been selected for the study, which employed reflectance and fluorescence sensing schemes, respectively. Batch binding analysis using the standard binding isotherm models was employed to evaluate the affinity of the binding sites. Evaluation using the discrete bi-Langmuir isotherm model found both the MIPs studied have generally two classes of binding sites that was of low and high affinities, while the continuous Freundlich isotherm model has successfully generated a distribution of affinities within the investigated analytical window. When the MIPs were incorporated as sensing receptors, the changes in the analytical signal due to different analyte concentrations were found to have direct correlation with the binding isotherm variables. Further data analyses based on this observation have generated robust models representing the analytical performance of the optical sensors. The best constructed model describing the sensing trend for each of the sensor has been tested and demonstrated to give accurate prediction of concentration for a series of spiked analytes.

Matched MeSH terms: Organic Chemicals
Fulltext Visible Light Driven Heterojunction Photocatalyst of CuO-Cu2O Thin Films for Photocatalytic Degradation of Organic Pollutants

Dasineh Khiavi N, Katal R, Kholghi Eshkalak S, Masudy-Panah S, Ramakrishna S, Jiangyong H

Nanomaterials (Basel), 2019 Jul 13;9(7).
PMID: 31337085 DOI: 10.3390/nano9071011

A high recombination rate and low charge collection are the main limiting factors of copper oxides (cupric and cuprous oxide) for the photocatalytic degradation of organic pollutants. In this paper, a high performance copper oxide photocatalyst was developed by integrating cupric oxide (CuO) and cuprous oxide (Cu2O) thin films, which showed superior performance for the photocatalytic degradation of methylene blue (MB) compared to the control CuO and Cu2O photocatalyst. Our results show that a heterojunction photocatalyst of CuO-Cu2O thin films could significantly increase the charge collection, reduce the recombination rate, and improve the photocatalytic activity.

Matched MeSH terms: Organic Chemicals
Fulltext Strain-Reduced Micro-LEDs Grown Directly Using Partitioned Growth

Lu S, Zhang Y, Zhang ZH, Tsai PC, Zhang X, Tan ST, et al.

Front Chem, 2021;9:639023.
PMID: 33816438 DOI: 10.3389/fchem.2021.639023

Strain-reduced micro-LEDs in 50 μm × 50 μm, 100 μm × 100 μm, 200 μm × 200 μm, 500 μm × 500 μm, and 1,000 μm × 1,000 μm sizes were grown on a patterned c-plane sapphire substrate using partitioned growth with the metal-organic chemical-vapor deposition (MOCVD) technique. The size effect on the optical properties and the indium concentration for the quantum wells were studied experimentally. Here, we revealed that the optical properties can be improved by decreasing the chip size (from 1,000 to 100 µm), which can correspondingly reduce the in-plane compressive stress. However, when the chip size is further reduced to 50 μm × 50 μm, the benefit of strain release is overridden by additional defects induced by the higher indium incorporation in the quantum wells and the efficiency of the device decreases. The underlying mechanisms of the changing output power are uncovered based on different methods of characterization. This work shows the rules of thumb to achieve optimal power performance for strain-reduced micro-LEDs through the proposed partitioned growth process.

Matched MeSH terms: Organic Chemicals
Fulltext Potential of citronella oil as natural mosquito repellent agent in formulated fabric softener finishes

Aznin Baharudin, Nor Akmalazura Jani, Azyati Azreen, A. A. Assyura, Hawa Pornomo, M. Hafiz Mehat

Borneo Akademika, 2020;4(1):1-12.
MyJurnal

This study is focused on formulating a natural-based fabric softener using baking
soda and vinegar with the addition of insect repellent finish of citronella oil and
vanillin. The effectiveness of the fabric softener was evaluated by conducting a fabric
stiffness test on both untreated and treated fabric samples with the softener
formulated in this study. The assessment for the efficacy of insect repellence was
carried out using 3 human participants of the same gender and build but different
blood type, positioned at a mosquito infested area. Three tests; negative, positive, and
normal tests were conducted to evaluate the effectiveness of the formulated mosquito
repellent finishes in the fabric softener. The results show that the formulated fabric
softener is good mosquito repellent and it is good at giving a soft effect on the treated
fabric.

Matched MeSH terms: Organic Chemicals
Protease activity is maintained in Nepenthes ampullaria digestive fluids depleted of endogenous proteins with compositional changes

Ravee R, Baharin A, Cho WT, Ting TY, Goh HH

Physiol Plant, 2021 Dec;173(4):1967-1978.
PMID: 34455610 DOI: 10.1111/ppl.13540

Nepenthes ampullaria is a unique carnivorous tropical pitcher plant with the detritivorous capability of sequestering nutrients from leaf litter apart from being insectivorous. The changes in the protein composition and protease activity of its pitcher fluids during the early opening of pitchers (D0 and D3C) were investigated via a proteomics approach and a controlled protein depletion experiment (D3L). A total of 193 proteins were identified. Common proteins such as pathogenesis-related protein, proteases (Nep [EC:3.4.23.12], SCP [EC:3.4.16.-]), peroxidase [EC:1.11.1.7], GDSL esterase/lipase [EC:3.1.1.-], and purple acid phosphatase [EC:3.1.3.2] were found in high abundance in the D0 pitchers and were replenished in D3L samples. This reflects their importance for biological processes upon pitcher opening. Meanwhile, prey-inducible chitinases [EC:3.2.1.14] were found in D0 but not in D3C and D3L samples, which suggests their degradation in the absence of prey. Protease activity assays demonstrated the replenishment of proteases in D3L with similar levels of proteolytic activities to that of D3C samples. This supports a feedback mechanism and signaling in the molecular regulation of endogenous protein secretion, turnover, and activity in Nepenthes pitcher fluids. Furthermore, we also discovered several new enzymes (XTH [EC:2.4.1.207], PAE [EC:3.1.1.98]) with possible functions in cell wall degradation that could contribute to the detritivory habit of N. ampullaria.

Matched MeSH terms: Organic Chemicals
Calculation of the release of total organic matter and total mineral using the hydrodynamic equations applied to palm oil mill effluent treatment by cascaded anaerobic ponds

Fulazzaky MA

Bioprocess Biosyst Eng, 2013 Jan;36(1):11-21.
PMID: 22622964 DOI: 10.1007/s00449-012-0756-7

Anaerobic treatment processes to remove organic matter from palm oil mill effluent (POME) have been used widely in Malaysia. Still the amounts of total organic and total mineral released from POME that may cause degradation of the receiving environment need to be verified. This paper proposes the use of the hydrodynamic equations to estimate performance of the cascaded anaerobic ponds (CAP) and to calculate amounts of total organic matter and total mineral released from POME. The CAP efficiencies to remove biochemical oxygen demands, chemical oxygen demands, total solids and volatile solids (VS) as high as 94.5, 93.6, 96.3 and 98.2 %, respectively, are estimated. The amounts of total organic matter and total mineral as high as 538 kg VS/day and 895 kg FS/day, respectively, released from POME to the receiving water are calculated. The implication of the proposed hydrodynamic equations contributes to more versatile environmental assessment techniques, sometimes replacing laboratory analysis.

Matched MeSH terms: Organic Chemicals/analysis*; Organic Chemicals/metabolism
Graphene-Based Materials as Solid Phase Extraction Sorbent for Trace Metal Ions, Organic Compounds, and Biological Sample Preparation

Ibrahim WA, Nodeh HR, Sanagi MM

Crit Rev Anal Chem, 2016 Jul 03;46(4):267-83.
PMID: 26186420 DOI: 10.1080/10408347.2015.1034354

Graphene is a new carbon-based material that is of interest in separation science. Graphene has extraordinary properties including nano size, high surface area, thermal and chemical stability, and excellent adsorption affinity to pollutants. Its adsorption mechanisms are through non-covalent interactions (π-π stacking, electrostatic interactions, and H-bonding) for organic compounds and covalent interactions for metal ions. These properties have led to graphene-based material becoming a desirable adsorbent in a popular sample preparation technique known as solid phase extraction (SPE). Numerous studies have been published on graphene applications in recent years, but few review papers have focused on its applications in analytical chemistry. This article focuses on recent preconcentration of trace elements, organic compounds, and biological species using SPE-based graphene, graphene oxide, and their modified forms. Solid phase microextraction and micro SPE (µSPE) methods based on graphene are discussed.

Matched MeSH terms: Organic Chemicals/isolation & purification*; Organic Chemicals/chemistry
Recent Progress in Delivery of Therapeutic and Imaging Agents Utilizing Organic-Inorganic Hybrid Nanoparticles

Haque ST, Chowdhury EH

Curr Drug Deliv, 2018;15(4):485-496.
PMID: 29165073 DOI: 10.2174/1567201814666171120114034

BACKGROUND: Delivery of conventional small molecule drugs and currently evolving nucleic acid-based therapeutics, such as small interfering RNAs (siRNAs) and genes, and contrast agents for high resolution imaging, to the target site of action is highly demanding to increase the therapeutic and imaging efficacy while minimizing the off-target effects of the delivered molecules, as well as develop novel therapeutic and imaging approaches.
METHODS: We have undertaken a structured search for peer-reviewed research and review articles predominantly indexed in PubMed focusing on the organic-inorganic hybrid nanoparticles with evidence of their potent roles in intracellular delivery of therapeutic and imaging agents in different animal models.
RESULTS: Organic-inorganic hybrid nanoparticles offer a number of advantages by combining the unique properties of the organic and inorganic counterparts, thus improving the pharmacokinetic behavior and targetability of drugs and contrast agents, and conferring the exclusive optical and magnetic properties for both therapeutic and imaging purposes. Different polymers, lipids, dendrimers, peptides, cell membranes, and small organic molecules are attached via covalent or non-covalent interactions with diverse inorganic nanoparticles of gold, mesoporous silica, magnetic iron oxide, carbon nanotubes and quantum dots for efficient drug delivery and imaging purposes.
CONCLUSION: We have thus highlighted here the progress made so far in utilizing different organicinorganic hybrid nanoparticles for in vivo delivery of anti-cancer drugs, siRNA, genes and imaging agents.

Matched MeSH terms: Inorganic Chemicals/administration & dosage; Inorganic Chemicals/chemistry*; Organic Chemicals/administration & dosage; Organic Chemicals/chemistry*
Landfill leachate treatment by an experimental subsurface flow constructed wetland in tropical climate countries

Ujang Z, Soedjono E, Salim MR, Shutes RB

Water Sci Technol, 2005;52(12):243-50.
PMID: 16477992

Municipal leachate was treated in an experimental unit of constructed wetlands of subsurface flow type. The parameters studied were organics (BOD and COD), solids and heavy metals (Zn, Ni, Cu, Cr and Pb). Using two types of emergent plants of Scirpus globulosus and Eriocaulon sexangulare, more than 80% removal was achieved for all the parameters. E. sexangulare removed organics and heavy metals better than Scirpus globulosus. A higher concentration of heavy metals in the influent did not change the removal efficiency.

Matched MeSH terms: Organic Chemicals/isolation & purification; Organic Chemicals/metabolism
Modified enzymes for reactions in organic solvents

Salleh AB, Basri M, Taib M, Jasmani H, Rahman RN, Rahman MB, et al.

Appl Biochem Biotechnol, 2002 10 25;102-103(1-6):349-57.
PMID: 12396136

Recent studies on biocatalysis in water-organic solvent biphasic systems have shown that many enzymes retain their catalytic activities in the presence of high concentrations of organic solvents. However, not all enzymes are organic solvent tolerant, and most have limited and selective tolerance to particular organic solvents. Protein modification or protein tailoring is an approach to alter the characteristics of enzymes, including solubility in organic solvents. Particular amino acids may play pivotal roles in the catalytic ability of the protein. Attaching soluble modifiers to the protein molecule may alter its conformation and the overall polarity of the molecule. Enzymes, in particular lipases, have been chemically modified by attachment of aldehydes, polyethylene glycols, and imidoesters. These modifications alter the hydrophobicity and conformation of the enzymes, resulting in changes in the microenvironment of the enzymes. By these modifications, newly acquired properties such as enhancement of activity and stability and changes in specificity and solubility in organic solvents are obtained. Modified lipases were found to be more active and stable in organic solvents. The optimum water activity (a(w)) for reaction was also shifted by using modified enzymes. Changes in enantioselective behavior were also observed.

Matched MeSH terms: Organic Chemicals/metabolism; Organic Chemicals/chemistry*
Co-composting of acid waste bentonites and their effects on soil properties and crop biomass

Soda W, Noble AD, Suzuki S, Simmons R, Sindhusen LA, Bhuthorndharaj S

J Environ Qual, 2006 Oct 27;35(6):2293-301.
PMID: 17071900

Acid waste bentonite is a byproduct from vegetable oil bleaching that is acidic (pH < 3.0) and hydrophobic. These materials are currently disposed of in landfills and could potentially have a negative impact on the effective function of microbes that are intolerant of acidic conditions. A study was undertaken using three different sources of acid waste bentonites, namely soybean oil bentonite (SB), palm oil bentonite (PB), and rice bran oil bentonite (RB). These materials were co-composted with rice husk, rice husk ash, and chicken litter to eliminate their acid reactivity and hydrophobic nature. The organic carbon (OC) content, pH, exchangeable cations, and cation exchange capacity (CEC) of the acid-activated bentonites increased significantly after the co-composting phase. In addition, the hydrophobic nature of these materials as measured using the water drop penetration time (WDPT) decreased from >10 800 s to 16 to 80 s after composting. Furthermore, these composted materials showed positive impacts on soil physical attributes including specific surface area, bulk density, and available water content for crop growth. Highly significant increases in maize biomass (Zea mays L.) production over two consecutive cropping cycles was observed in treatments receiving co-composted bentonite. The study clearly demonstrates the potential for converting an environmentally hazardous material into a high-quality soil conditioner using readily available agricultural byproducts. It is envisaged that the application of these composted acid waste bentonites to degraded soils will increase productivity and on-farm income, thus contributing toward food security and poverty alleviation.

Matched MeSH terms: Organic Chemicals/metabolism; Organic Chemicals/chemistry
Graphene oxide as a structure-directing agent for the two-dimensional interface engineering of sandwich-like graphene-g-C3N4 hybrid nanostructures with enhanced visible-light photoreduction of CO2 to methane

Ong WJ, Tan LL, Chai SP, Yong ST

Chem Commun (Camb), 2015 Jan 18;51(5):858-61.
PMID: 25429376 DOI: 10.1039/c4cc08996k

A facile one-pot impregnation-thermal reduction strategy was employed to fabricate sandwich-like graphene-g-C3N4 (GCN) nanocomposites using urea and graphene oxide as precursors. The GCN sample exhibited a slight red shift of the absorption band edge attributed to the formation of a C-O-C bond as a covalent cross linker between graphene and g-C3N4. The GCN sample demonstrated high visible-light photoactivity towards CO2 reduction under ambient conditions, exhibiting a 2.3-fold enhancement over pure g-C3N4. This was ascribed to the inhibition of electron-hole pair recombination by graphene, which increased the charge transfer.

Matched MeSH terms: Organic Chemicals
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: Organic Chemicals/chemical synthesis; Organic Chemicals/pharmacokinetics; Organic Chemicals/chemistry
Comparative study on the process behavior and reaction kinetics in sonocatalytic degradation of organic dyes by powder and nanotubes TiO2

Pang YL, Abdullah AZ

Ultrason Sonochem, 2012 May;19(3):642-51.
PMID: 22000097 DOI: 10.1016/j.ultsonch.2011.09.007

Sonocatalytic degradation of various organic dyes (Congo Red, Reactive Blue 4, Methyl Orange, Rhodamine B and Methylene Blue) catalyzed by powder and nanotubes TiO(2) was studied. Both catalysts were characterized using transmission electron microscope (TEM), surface analyzer, Raman spectroscope and thermal gravimetric analyzer (TGA). Sonocatalytic activity of powder and nanotubes TiO(2) was elucidated based on the degradation of various organic dyes. The former catalyst was favorable for treatment of anionic dyes, while the latter was more beneficial for cationic dyes. Sonocatalytic activity of TiO(2) nanotubes could be up to four times as compared to TiO(2) powder under an ultrasonic power of 100 W and a frequency of 42 kHz. This was associated with the higher surface area and the electrostatic attraction between dye molecules and TiO(2) nanotubes. Fourier transform-infrared spectrometer (FT-IR) was used to identify changes that occurred on the functional group in Rhodamine B molecules and TiO(2) nanotubes after the reaction. Sonocatalytic degradation of Rhodamine B by TiO(2) nanotubes apparently followed the Langmuir-Hinshelwood adsorption kinetic model with surface reaction rate of 1.75 mg/L min. TiO(2) nanotubes were proven for their high potential to be applied in sonocatalytic degradation of organic dyes.

Matched MeSH terms: Organic Chemicals/isolation & purification; Organic Chemicals/radiation effects*; Organic Chemicals/chemistry*

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links