MyMedR

Displaying publications 201 - 220 of 316 in total

Abstract:

Sort:

Biogenic approach to synthesize rod shaped Gd2 O3 nanoparticles and its optimization using response surface methodology-Box-Behnken design model

Surendra TV, Mohana Roopan S, Khan MR

Biotechnol Prog, 2019 07;35(4):e2823.
PMID: 31017346 DOI: 10.1002/btpr.2823

The rare earth metal oxide nanoparticles such as gadolinium oxide nanoparticles (Gd2 O3 NPs) have been synthesized by green synthesis process using methanolic extract of Moringa oleifera (M oleifera) peel. In this process, the Gd2 O3 NPs formation was observed at 280-300 nm in UV-Vis spectroscopy. The XRD pattern of the synthesized Gd2 O3 NPs was exactly matched with JCPDS No 3-065-3181which confirms the crystalline nature of Gd2 O3 NPs. In addition, Energy-dispersive X-ray spectroscopy (EDX) analysis was stated that Gd and O elements were present as 70.31 and 29.69%, respectively in Gd2 O3 NPs. The SEM and TEM analysis were said Gd2 O3 NPs are in rod shape and 26 ± 2 nm in size. Further the synthesized Gd2 O3 NPs were confirmed by X-ray photoemission spectroscopy (XPS). The synthesized Gd2 O3 NPs were further examined for anti-fungal activity against Alternaria saloni (A saloni) and Sclerrotium rolfsii (S rolfsii) and it showed moderate activity. Also, Gd2 O3 NPs evaluated as good antibacterial agent against different Gram +ve and Gram -ve bacteria. Moreover, the toxicity of the Gd2 O3 NPs on red blood cells (RBCs) of the human blood was determined using hemolytic assay, the obtained results were stated the synthesized Gd2 O3 NPs are nontoxic to the human erythrocytes. The photocatalytic activity against malachite green (MG) dye was tested and confirmed as 92% of dye was degraded within 2 hr by Gd2 O3 NPs. The results were stated the green synthesized Gd2 O3 NPs are good anti-fungal agents, nontoxic and we can use as a photocatalyst. Copyright © 2019 John Wiley & Sons, Ltd.

Matched MeSH terms: Coloring Agents/chemical synthesis; Coloring Agents/pharmacology; Coloring Agents/chemistry*
Fulltext Application of Efficient Magnetic Particles and Activated Carbon for Dye Removal from Wastewater

Moosavi S, Lai CW, Gan S, Zamiri G, Akbarzadeh Pivehzhani O, Johan MR

ACS Omega, 2020 Aug 25;5(33):20684-20697.
PMID: 32875202 DOI: 10.1021/acsomega.0c01905

Since the turn of the 21st century, water pollution has been a major issue, and most of the pollution is generated by dyes. Adsorption is one of the most commonly used dye-removal methods from aqueous solution. Magnetic-particle integration in the water-treatment industry is gaining considerable attention because of its outstanding physical and chemical properties. Magnetic-particle adsorption technology shows promising and effective outcomes for wastewater treatment owing to the presence of magnetic material in the adsorbents that can facilitate separation through the application of an external magnetic field. Meanwhile, the introduction of activated carbon (AC) derived from various materials into a magnetic material can lead to efficient organic-dye removal. Therefore, this combination can provide an economical, efficient, and environmentally friendly water-purification process. Although activated carbon from low-cost and abundant materials has considerable potential in the water-treatment industry, the widespread applications of adsorption technology are limited by adsorbent recovery and separation after treatment. This work specifically and comprehensively describes the use of a combination of a magnetic material and an activated carbon material for dye adsorption in wastewater treatment. The literature survey in this mini-review provides evidence of the potential use of these magnetic adsorbents, as well as their magnetic separation and recovery. Future directions and challenges of magnetic activated carbon in wastewater treatment are also discussed in this paper.

Matched MeSH terms: Coloring Agents
Zwitterion composite chitosan-epichlorohydrin/zeolite for adsorption of methylene blue and reactive red 120 dyes

Jawad AH, Abdulhameed AS, Reghioua A, Yaseen ZM

Int J Biol Macromol, 2020 Nov 15;163:756-765.
PMID: 32634511 DOI: 10.1016/j.ijbiomac.2020.07.014

In this research, an attempt to develop zwitterion composite adsorbent is conducted by modifying chitosan (CHS) with a covalent cross-linker (epichlorohydrin, ECH) and an aluminosilicate mineral (zeolite, ZL). The zwitterion composite adsorbent of chitosan-epichlorohydrin/zeolite (CHS-ECH/ZL) is performed multifunctional tasks by removing two structurally different cationic (methylene blue dye, MB), and anionic (reactive red 120 dye, RR120) dyes from aqueous solutions. The surface property, crystallinity, morphology, functionality, and charge of the CHS-ECH/ZL are analyzed using BET, XRD, SEM, FTIR, and pHpzc, analyses, respectively. The influence of pertinent parameters namely CHS-ECH/ZL dosage (0.02-0.5 g), solution pH (4-10), temperature (303-323K), initial dye concentration (30-400 mg/L), and contact time (0-600 min) on the MB and RR120 removal are tested. The research findings revealed that the adsorption isotherm at equilibrium well explained in according to the Freundlich isotherm model, and the recorded adsorption capacities of CHS-ECH/ZL are 156.1 and 284.2 mg/g for MB and RR120 respectively at 30 °C. The mechanism of MB and RR120 adsorption onto the CHS-ECH/ZL indicates various types of interactions namely, electrostatic interaction, hydrogen bonding, and Yoshida H-bonding in addition to n-π interaction. Overall, this research introduces CHS-ECH/ZL composite as an eco-friendly zwitterion adsorbent with good applicability towards the two structurally different cationic and anionic dyes from aqueous environment.

Matched MeSH terms: Coloring Agents
Fulltext DETERMINATION OF REACTIVE BLACK 5 (RB5) BY DIFFERENTIAL PULSE ANODIC STRIPPING VOLTAMMETRIC TECHNIQUE

Nur Syamimi Zainudin, Nur Aqilah Abdul Rahman

Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2021;9(1):73-79.
MyJurnal

Dyes are aromatic organic compound which have an affinity towards the substrate to which they are being applied to. The presence of dyes in wastewater samples is not safe for human even at low level. The presence of dyes in wastewater which are discharged from textile industry must be analysed. Hence, a precise, fast, accurate, simple and inexpensive analytical method with low detection limit is needed for the determination of dyes in wastewaters. The differential pulse anodic stripping voltammetric (DPASV) technique using bare glassy carbon electrode (GCE) as a working electrode and phosphate buffer at pH 4.2 as a supporting electrolyte has been proposed for Reactive Black 5 (RB5) determination. Several experimental voltammetric parameters were being optimized for obtaining a maximum response before analytical validation of the proposed technique being carried out. The optimum parameters were initial potential (Ei) = +0.3 V, end potential (Ef) = +1.0 V, scan rate (v) = 0.04 V/s, accumulation time (tacc) = 50 s, accumulation potential (Eacc) = 0.4 V and pulse amplitude = 0.075 V. The well-defined anodic peak appeared at 0.77972 V. The response was linear from 0.5 to 1.25 mg/L (R2=0.9986) with LOD of 0.050 mg/L. The relative standard deviation (RSD) achieved were 0.08 %, 0.62 % and 0.50 %, respectively for three consecutive days. The % recovery range achieved was from 89.71 % to 111.15 %. It can be concluded that the proposed technique is precise, accurate, inexpensive, fast and has a potential to be an alternative analytical technique for RB5 analysis. The proposed method will in the future be tested for the amount of RB5 in the wastewater samples from textile industry.

Matched MeSH terms: Coloring Agents
Chitosan modifications for adsorption of pollutants - A review

Saheed IO, Oh WD, Suah FBM

J Hazard Mater, 2021 04 15;408:124889.
PMID: 33418525 DOI: 10.1016/j.jhazmat.2020.124889

In recent times, research interest into the development of biodegradable, cost-effective and environmental friendly adsorbents with favourable properties for adsorption of pollutants is a challenge. Modification of chitosan via different physical and chemical methods have gained attention as a promising approach for removing organic (such as dyes and pharmaceuticals) and inorganic (such as metal/metal ions) pollutants from aqueous medium. In this regard, researchers have reported grafting and cross-linking approach among others as a potentially useful method for chitosan's modification for improved adsorption efficiency with respect to pollutant uptake. This article reviews the trend in chitosan modification, with regards to the summary of some recently published works on modification of chitosan and their adsorption application in pollutants (metal ion, dyes and pharmaceuticals) removal from aqueous medium. The review uniquely highlights some common cross-linkers and grafting procedures for chitosan modification, their influence on structure and adsorption capacity of modified-chitosan with respect to pollutants removal. Findings revealed that the performance of modified chitosan for adsorption of pollutants depends largely on the modification method adopted, materials used for the modification and adsorption experimental conditions. Cross-linking is commonly utilized for improving the chemical and mechanical stabilities of chitosan but usually decreases adsorption capacity of chitosan/modified-chitosan for adsorption of pollutants. However, literature survey revealed that adsorption capacity of cross-linked chitosan based materials have been enhanced in recently published works either by grafting, incorporation of solid adsorbents (e.g metals, clays and activated carbon) or combination of both prior to cross-linking.

Matched MeSH terms: Coloring Agents
Bioremediation and Detoxification of the Textile Wastewater with Membrane Bioreactor Using the White-rot Fungus and Reuse of Wastewater

Hossain K, Quaik S, Ismail N, Rafatullah M, Avasan M, Shaik R

Iran J Biotechnol, 2016 Sep;14(3):154-162.
PMID: 28959331 DOI: 10.15171/ijb.1216

BACKGROUND: Application of membrane technology to wastewater treatment has expanded over the last decades due to increasingly stringent legislation, greater opportunities for water reuse/recycling processes and continuing advancement in membrane technology.
OBJECTIVES: In the present study, a bench-scale submerged microfiltration membrane bioreactor (MBR) was used to assess the treatment of textile wastewater.
MATERIALS AND METHODS: The decolorization capacity of white-rot fungus coriolus versicolor was confirmed through agar plate and liquid batch studies. The temperature and pH of the reactor were controlled at 29±1°C and 4.5±2, respectively. The bioreactor was operated with an average flux of 0.05 m.d(-1) (HRT=15hrs) for a month.
RESULTS: Extensive growth of fungi and their attachment to the membrane led to its fouling and associated increase of the transmembrane pressure requiring a periodic withdrawal of sludge and membrane cleaning. However, stable decoloration activity (approx. 98%), BOD (40-50%), COD (50-67%) and total organic carbon (TOC) removal (>95%) was achieved using the entire system (fungi + membrane), while the contribution of the fungi culture alone for TOC removal, as indicated by the quality of the reactor supernatant, was 35-50% and 70%, respectively.
CONCLUSIONS: The treated wastewater quality satisfied the requirement of water quality for dyeing and finishing process excluding light coloration. Therefore, textile wastewater reclamation and reuse is a promising alternative, which can both conserve or supplement the available water resource and reduce or eliminate the environmental pollution.

Matched MeSH terms: Coloring Agents
A comprehensive review on magnetic carbon nanotubes and carbon nanotube-based buckypaper for removal of heavy metals and dyes

Khan FSA, Mubarak NM, Tan YH, Khalid M, Karri RR, Walvekar R, et al.

J Hazard Mater, 2021 07 05;413:125375.
PMID: 33930951 DOI: 10.1016/j.jhazmat.2021.125375

Industrial effluents contain several organic and inorganic contaminants. Among others, dyes and heavy metals introduce a serious threat to drinking waterbodies. These pollutants can be noxious or carcinogenic in nature, and harmful to humans and different aquatic species. Therefore, it is of high importance to remove heavy metals and dyes to reduce their environmental toxicity. This has led to an extensive research for the development of novel materials and techniques for the removal of heavy metals and dyes. One route to the removal of these pollutants is the utilization of magnetic carbon nanotubes (CNT) as adsorbents. Magnetic carbon nanotubes hold remarkable properties such as surface-volume ratio, higher surface area, convenient separation methods, etc. The suitable characteristics of magnetic carbon nanotubes have led them to an extensive search for their utilization in water purification. Along with magnetic carbon nanotubes, the buckypaper (BP) membranes are also favorable due to their unique strength, high porosity, and adsorption capability. However, BP membranes are mostly used for salt removal from the aqueous phase and limited literature shows their applications for removal of heavy metals and dyes. This study focuses on the existence of heavy metal ions and dyes in the aquatic environment, and methods for their removal. Various fabrication approaches for the development of magnetic-CNTs and CNT-based BP membranes are also discussed. With the remarkable separation performance and ultra-high-water flux, magnetic-CNTs, and CNT-based BP membranes have a great potential to be the leading technologies for water treatment in future.

Matched MeSH terms: Coloring Agents
Enhanced Photocatalytic Behavior of (GO/Cu₂O) Composite with Cu₂O Being Synthesized Through Green Route

Muthukumaran M, Dhinagaran G, Narayanan V, Raju T, Venkatachalam K, Karthika PC, et al.

J Nanosci Nanotechnol, 2019 Nov 01;19(11):7215-7220.
PMID: 31039878 DOI: 10.1166/jnn.2019.16671

Graphene oxide/Cuprous oxide (GO/Cu₂O) composite is a visible light photocatalyst for the degradation of dyes. A simple and efficient approach for preparing GO/Cu₂O composite adopted in this study involves reducing cuprous oxide precursors in the presence of graphene oxide using an aqueous solution of pulp derived from banana fruit. The GO/Cu₂O composite was characterized by Fourier transform infrared spectroscopy (FT-IR), Diffused reflectance Ultraviolet visible spectroscopy (DRS UV-Vis), Raman spectroscopy and Field Emission Scanning electron microscopy (FE-SEM). Cu₂O particles were distributed randomly on the graphene oxide sheets due to the template effect of GO. The results showed higher photocatalytic activity for the composite (band gap 2.13 eV), for the degradation of the organic dyes (Methylene blue and Rhodamine-B). The enhanced photocatalytic activity is due to effective charge transfer from GO to Cu₂O, and high specific surface area which improves the effective separation of the generated electron-hole pairs. Our present study is inspired by a facile, low cost, green production of (GO/Cu₂O) composite whose photocatalytic activity can be extended to degradation of all other water-born textile dyes.

Matched MeSH terms: Coloring Agents
Fulltext Inhibition Of Stain By Some Commercially Available Oral Hygiene Products

Swaminathan, D., Moran, John, Addy, Martin

Ann Dent, 1996;3(1):-.
MyJurnal

Side effects such as abrasion of the dental hard tissue have been frequently observed following the extensive use of mechanical cleansing. As promising antiseptics like chlorhexidine produces extrinsic dental staining on long term usage, there has been increasing interest and research generated towards chemically based stain removing agents. This invitro studyexamined whether some commercial oral hygiene products could inhibit chlorhexidine derived stain independent of any mechanical cleansing action. Perspex blocks were soaked in triplicate in chlorhexidine solution for 2 minutesand stain inhibition by these products was determined by further soaking the blocks in productl water slurries for 2 minutes and finally in tea solution for I hourly periods. The optical density (OD) of each specimen was determined at each hourly interval by spectrophotometry at 395 nm and the mean values obtained. At the end of the study, most of the products inhibited stain compared to water control and there was a variation in the stain inhibitingefficacyof the products. It is thus concluded that oral hygiene products like dentifricesand mouthrinses can inhibit chlorhexidine derived extrinsic dental stain to a variable degree through a chemical action by contained ingredients.

Matched MeSH terms: Coloring Agents
Fulltext Primary tuberculosis of palate

Chen I, Jamal S, Pua KC

Malays Fam Physician, 2015;10(3):32-4.
PMID: 27570606 MyJurnal

Primary tuberculosis (TB) of the hard palate is very rare. A 74-year-old man was presented with 6-month history of dysphagia along with an irregular mass in the hard and soft palate. Magnetic resonance imaging (MRI) revealed thickened and increased signal intensity within hard and soft palate. Tissue biopsy showed focal caseating granulomatous-like lesion and the histochemical staining using Ziehl-Neelsen stain for acid-fast bacilli was positive. Positive histochemical studies provided evidences that the hard palate mass was most likely due to TB. Thus, the patient was started on antituberculous therapy.

Matched MeSH terms: Coloring Agents
Fulltext Toothpastes Available In The Malaysian Market

Saub, R.

Ann Dent, 1998;5(1):-.
MyJurnal

This study was undertaken to investigate the number and types (fluoride or non-fluoride) of toothpaste products available in the Malaysian market based on the label. Thirty-five brands of toothpaste were identified, of which ten (29%) were specifically recommended for children. Two of the children's toothpaste recommended that children below seven years old use a pea size amount of toothpaste. One (3%) was recommended for both children and adult. The remaining 24 (69%) did not state if they were recommended for either children or adults. To improve the flavour of the toothpastes, a variety of flavours had been added especially in children's toothpaste. Almost half of the toothpastes were for prevention of tooth decay and gum disease. Other indications were for tooth sensitivity, tooth whitening and stain removal. Twentyseven (77%) of the toothpastes were imported, while eight (23%) were made in Malaysia. Twenty-six (74%) of the toothpaste contained fluoride and the most common type of fluoride used was sodium monofluorophosphate (NaMFP). The fluoride concentration was not labeled in more than half (63%) of the fluoridated toothpaste. Of those that were fluoridated, different units of measurement were used. As there is no uniformity in the labelling of these products, it is recommended that the responsible authorities should take more action in enforcing proper labelling of the fluoride concentration in the toothpaste using standardized units.

Matched MeSH terms: Coloring Agents
Fulltext Evaluation of Ocular Surface Disease in Asian Patients with Primary Angle Closure

Ling TE, Othman K, Yan OP, Rashid RA, Tet CM, Yaakob A, et al.

Open Ophthalmol J, 2017;11:31-39.
PMID: 28400889 DOI: 10.2174/1874364101711010031

OBJECTIVE: To evaluate the incidence of ocular surface disease (OSD) and to determine the effects of topical pressure-lowering drugs on ocular surface disease in primary angle closure patients.
METHODS: This was a cross-sectional comparative study comparing primary angle closure glaucoma (PACG) patients (Group A) with primary angle closure and primary angle closure suspect (Group B). Group A was treated with topical pressure-lowering drugs; Group B was not. Data on ocular diagnosis and details of treatment were obtained from medical records. Ocular surface disease incidence was assessed using the Ocular Surface Disease Index (OSDI) questionnaire and from clinical signs using Schirmer's test, tear break-up time and corneal fluorescein stain. Predictive Analytic Software 20 and STATA analysis software were used for statistical analyses.
RESULTS: Group A demonstrated a higher rate of OSD (OSDI 52.3%, Schirmer's test 70.5%, tear break-up time (TBUT) 75%, corneal staining 77.3%) compared to Group B (OSDI 39.0%, Schirmer's test 73.2%, TBUT 58.5% and cornea staining 14.6%) except for Schirmer's test. There was a significant difference in mean score of OSDI (p=0.004), TBUT (p=0.008) and cornea staining (p<0.001) between two groups. Primary angle closure glaucoma treated with more than two medications and for more than three years had worse ocular surface disease parameters but without statistical significant difference.
CONCLUSION: Ocular surface disease is common in PACG patients treated with topical pressure-lowering drugs. Topical pressure-lowering drugs caused significant OSD symptoms and signs except for tear production in PACG patients. Thorough evaluation of ocular surface disease is important to ensure appropriate treatment and intervention in PACG patients.

Matched MeSH terms: Coloring Agents
Decolorization and mineralization of Amaranth dye using multiple zoned aerobic and anaerobic baffled constructed wetland

Lehl HK, Ong SA, Ho LN, Wong YS, Saad FNM, Oon YL, et al.

Int J Phytoremediation, 2017 Aug 03;19(8):725-731.
PMID: 28448169 DOI: 10.1080/15226514.2017.1284748

The objective of this study is to determine the reduction efficiency of Chemical Oxygen Demand (COD) as well as the removal of color and Amaranth dye metabolites by the Aerobic-anaerobic Baffled Constructed Wetland Reactor (ABCW). The ABCW reactor was planted with common reed (Phragmite australis) where the hydraulic retention time (HRT) was set to 1 day and was fed with synthetic wastewater with the addition of Amaranth dye. Supplementary aeration was supplied in designated compartments of the ABCW reactor to control the aerobic and anaerobic zones. After Amaranth dye addition the COD reduction efficiency dropped from 98 to 91% while the color removal efficiency was 100%. Degradation of azo bond in Amaranth dye is shown by the UV-Vis spectrum analysis which demonstrates partial degradation of Amaranth dye metabolites. The performance of the baffled unit is due to the longer pathway as there is the up-flow and down-flow condition sequentially, thus allowing more contact of the wastewater with the rhizomes and micro-aerobic zones.

Matched MeSH terms: Coloring Agents
Fulltext Mitochondrial DNA Mutations in Grade II and III Glioma Cell Lines Are Associated with Significant Mitochondrial Dysfunction and Higher Oxidative Stress

Soon BH, Abdul Murad NA, Then SM, Abu Bakar A, Fadzil F, Thanabalan J, et al.

Front Physiol, 2017;8:231.
PMID: 28484394 DOI: 10.3389/fphys.2017.00231

The role of mitochondria in tumorigenesis has regained much attention as it could dysregulate cellular energetics, oxidative stress and apoptosis. However, the role of mitochondria in different grade gliomasis still unknown. This study aimed to identify mitochondrial DNA (mtDNA) sequence variations that could possibly affect the mitochondrial functions and also the oxidative stress status. Three different grades of human glioma cell lines and a normal human astrocyte cell line were cultured in-vitro and tested for oxidative stress biomarkers. Relative oxidative stress level, mitochondria activity, and mitochondrial mass were determined by live cell imaging with confocal laser scanning microscope using CM-H2DCFDA, MitoTracker Green, and MitoTracker Orange stains. The entire mitochondrial genome was sequenced using the AffymetrixGeneChip Human Mitochondrial Resequencing Array 2.0. The mitochondrial sequence variations were subjected to phylogenetic haplogroup assessment and pathogenicity of the mutations were predicted using pMUT and PolyPhen2. The Grade II astrocytoma cells showed increased oxidative stress wherea high level of 8-OHdG and oxidative stress indicator were observed. Simultaneously, Grade II and III glioma cells showed relatively poor mitochondria functions and increased number of mutations in the coding region of the mtDNA which could be due to high levels of oxidative stress in these cells. These non-synonymous mtDNA sequence variations were predicted to be pathogenic and could possibly lead to protein dysfunction, leading to oxidative phosphorylation (OXPHOS) impairment, mitochondria dysfunction and could create a vicious cycle of oxidative stress. The Grade IV cells had no missense mutation but preserved intact mitochondria and excellent antioxidant defense mechanisms thus ensuring better survival. In conclusion, Grade II and III glioma cells demonstrated coding region mtDNA mutations, leading to mitochondrial dysfunction and higher oxidative stress.

Matched MeSH terms: Coloring Agents
Fulltext Validation of oligonucleotide microarray gene expression profiles by real-time PCR using SYBR-Green 1 fluorescence

Nik Norliza Nik Hassan, Rozita Rosli, Abdul Munir Abdul Murad, Nor Kaslina Kornain, Sabariah, A.R., Rohan Malek Johan, et al.

Buletin Persatuan Genetik Malaysia, 2008;14(1):1-16.
MyJurnal

DNA microarray technology has permitted large scale parallel analysis of gene expression of several diseases, including cancers. Real-time PCR has become a well-established procedure for
quantifying levels of gene expression. We evaluated Real-Time PCR to validate differentially expressed genes identified by DNA arrays. Gene expression of three different grade of transitional cell carcinoma (TCC) of human bladder cancer was determined using microarray slide containing cancer-related genes. Data obtained were sorted according based on the ratios between Cy3 and Cy5 dyes used and revealed 119, 235 and 183 differentially expressed genes in TCC WHO Grades I, II and III, respectively. Real-time PCR used SYBR Green-1 dye detection to validate relative change in gene expression. Real- Time PCR confirmed the change in gene expression of 17 of 28 (75%) genes identified by microarray. Real-Time PCR also suggest that genes identified by microarray with two or higher fold change cannot be eliminated as false nor be accepted as true without validation. Real-Time PCR based on SYBR Green- 1 is well-suited to validate DNA array results because it is quantitative, rapid and requires less RNA compared to the conventional assays.

Matched MeSH terms: Coloring Agents
Fulltext Patient's Perceptions And Knowledge On Tooth Bleaching

Ahmad, R., Ariffin, E.H.Z.M., Vengrasalam, I., Kasim, N.H.A.

Ann Dent, 2005;12(1):-.
MyJurnal

The main objective of this study was to assess knowledge on tooth bleaching among patients visiting dental health care centres in Klang Valley. A total of 200 patients were conveniently selected and interviewed using structured questionnaires. Among the 200 respondents, 75.5% knew about bleaching. There was no statistically significant difference in knowledge of bleaching in relation to age, gender, ethnic group and income level of the patients interviewed (p>0.05) but the education level had a significant influence (p=0.049). Respondents with tertiary education had better knowledge about tooth bleaching as compared to those respondents without tertiary education. The sources of information about bleaching came from advertisements on electronic media (65.5%), articles in newspapers and magazines (14.7%), dentists (10.9%) and family and friends (8.8%). Out of the 75.5% of respondents who knew about bleaching, 18.2% had tried bleaching their teeth using either over-the-counter products or had undergone professional bleaching treatment. The commonest reasons cited for bleaching treatment were to remove coffee and tea stains (70%) and cigarette stains (16.7%). 73.3% of these patients were satisfied with the results achieved after bleaching. However, the majority of these patients (59.6%) were unsure of the safety of these bleaching products/procedures. In conclusion, 75.5% of patients interviewed in this study knew that bleaching is one of the treatment options available to improve dental aesthetics but only 18.2% have tried bleaching their teeth. Their main source of knowledge about bleaching came from advertisements on electronic media.

Matched MeSH terms: Coloring Agents
Fulltext Adsorption of acid dyes onto Zinc Chloride-Modified Cocoa (Theobroma Cacao) pod Husk-based carbon

Nur Aqilah Zainal, Shariff Ibrahim, Borhannuddin Arifin

Pertanika Journal of Science & Technology, 2017;25(103):129-138.
MyJurnal

An agricultural waste, the cocoa pod husk was chemically modified using a dehydrating agent, zinc chloride (ZnCl2), carbonised and used for the remediation of acid dyes in an aqueous solution. The targeted acid dyes are: (i) Acid Violet 17 (AV17); (ii) Acid Yellow 36 (AY36); and (iii) Acid Blue 29 (AB29). The physicochemical properties of the zinc chloride-modified cocoa pod husk-based carbon (ZCPHC) were characterised by ash content, bulk density, pH slurry, pHpzc and Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-Ray (EDX) analysis. The bulk density and ash content of the prepared carbon is 0.55 g cm-1 and 7.0% respectively. The photograph of SEM shows distinct changes at the ZCPHC carbon surface as it has large pores formed due to ZnCl2 modification. The adsorption tests were performed in a batch adsorption system using an aqueous solution of the understudy acid dyes. The influence of pH and dose of an adsorbent on the acid dye uptake was investigated and discussed. The adsorption was in favour at acidic condition with maximum removal observed at pH 2. The removal efficiency of the aqueous acid dye solution increased with the increase in adsorbent dosage. The kinetic experiment showed equilibrium time is less than 40 minutes and the kinetic data for all three understudy acid dyes fitted well with the pseudo-second-order model with a correlation coefficient (R2) values above 0.98.

Matched MeSH terms: Coloring Agents
Effect of degree of deacetylation of chitosan on adsorption capacity and reusability of chitosan/polyvinyl alcohol/TiO2 nano composite

Habiba U, Joo TC, Siddique TA, Salleh A, Ang BC, Afifi AM

Int J Biol Macromol, 2017 Nov;104(Pt A):1133-1142.
PMID: 28690164 DOI: 10.1016/j.ijbiomac.2017.07.007

The chitosan/polyvinyl alcohol/TiO2 composite was synthesized. Two different degrees of deacetylation of chitosan were prepared by hydrolysis to compare the effectiveness of them. The composite was analyzed via field emission scanning electron microscopy, Fourier transform infrared, X-ray diffraction, thermal gravimetric analysis, weight loss test and adsorption study. The FTIR and XRD results proved the interaction among chitosan, PVA and TiO2 without any chemical reaction. It was found that, chitosan with higher degree of deacetylation has better stability. Furthermore, it also showed that higher DD of chitosan required less time to reach equilibrium for methyl orange. The adsorption followed the pseudo-second-order kinetic model. The Langmuir and Freundlich isotherm models were fitted well for isotherm study. Adsorption capacity was higher for the composite containing chitosan with higher DD. The dye removal rate was independent of the dye's initial concentration. The adsorption capacity was increased with temperature and it was found from reusability test that the composite containing chitosan with higher DD is more reusable. It was notable that adsorption capacity was even after 15 runs. Therefore, chitosan/PVA/TiO2 composite can be a very useful material for dye removal.

Matched MeSH terms: Coloring Agents
Frequency-controlled wireless shape memory polymer microactuator for drug delivery application

Zainal MA, Ahmad A, Mohamed Ali MS

Biomed Microdevices, 2017 Mar;19(1):8.
PMID: 28124762 DOI: 10.1007/s10544-017-0148-5

This paper reports the wireless Shape-Memory-Polymer actuator operated by external radio frequency magnetic fields and its application in a drug delivery device. The actuator is driven by a frequency-sensitive wireless resonant heater which is bonded directly to the Shape-Memory-Polymer and is activated only when the field frequency is tuned to the resonant frequency of heater. The heater is fabricated using a double-sided Cu-clad Polyimide with much simpler fabrication steps compared to previously reported methods. The actuation range of 140 μm as the tip opening distance is achieved at device temperature 44 °C in 30 s using 0.05 W RF power. A repeatability test shows that the actuator's average maximum displacement is 110 μm and standard deviation of 12 μm. An experiment is conducted to demonstrate drug release with 5 μL of an acidic solution loaded in the reservoir and the device is immersed in DI water. The actuator is successfully operated in water through wireless activation. The acidic solution is released and diffused in water with an average release rate of 0.172 μL/min.

Matched MeSH terms: Coloring Agents
Development of Aurantiochytrium limacinum SR21 cultivation using salt-rich waste feedstock for docosahexaenoic acid production and application of natural colourant in food product

Leong HY, Su CA, Lee BS, Lan JC, Law CL, Chang JS, et al.

Bioresour Technol, 2019 Jan;271:30-36.
PMID: 30261334 DOI: 10.1016/j.biortech.2018.09.093

Microalgae biorefinery is presently receiving a lot of attention as driven by its production of high value-added products. In this study, an oleaginous microalga Aurantiochytrium limacinum SR21 was cultured for docosahexaenoic acid (DHA) production using 20% (w/v) of K2HPO4-waste feedstock to replace 0.005% (w/v) of KH2PO4 in the flask culture. DHA is an essential nutrient for human's brain functionalities. Collectively, the K2HPO4-waste feedstock with working concentration of 0.005% (w/v) in the cultivation prompted a higher lipid content (8.29%) and DHA production (128.81 mg.L-1). Moreover, natural plant pigment products containing stabilised betacyanins were utilised as natural red colourants for hard candy production. This study develops microalgal cultivation using salt-rich waste feedstock for a higher lipid and DHA content as well as application of natural colouring agents in food products.

Matched MeSH terms: Coloring Agents

Filters

Please provide feedback to Administrator ([email protected])

External Links