Displaying publications 101 - 120 of 165 in total

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  1. Blended Nephelium lappaceum and Durio zibethinus wastes for activated carbon production via microwave-ZnCl2 activation: optimization for methylene blue dye removal
    Jawad AH, Hapiz A, Wu R, Abdulhameed AS, ALOthman ZA
    Int J Phytoremediation, 2024;26(10):1655-1666.
    PMID: 38711172 DOI: 10.1080/15226514.2024.2344178
    Herein, this work targets to employ the blended fruit wastes including rambutan (Nephelium lappaceum) peel and durian (Durio zibethinus) seed as a promising precursor to produce activated carbon (RPDSAC). The generation of RPDSAC was accomplished through a rapid and practical procedure (microwave-ZnCl2 activation). To evaluate the adsorptive capabilities of RPDSAC, its efficacy in eliminating methylene blue (MB), a simulated cationic dye, was measured. The Box-Behnken design (BBD) was utilized to optimize the crucial adsorption parameters, namely A: RPDSAC dose (0.02-01 g/100 mL), B: pH (4-10), and C: time (2-6 min). The BBD design determined that the highest level of MB removal (79.4%) was achieved with the condition dosage of RPDSAC at 0.1 g/100 mL, contact time (6 min), and pH (10). The adsorption isotherm data is consistent with the Freundlich concept, and the pseudo-second-order versions adequately describe the kinetic data. The monolayer adsorption capacity (qmax) of RPDSAC reached 120.4 mg/g at 25 °C. Various adsorption mechanisms are involved in the adsorption of MB dye onto the surface of RPDSAC, including π-π stacking, H-bonding, pore filling, and electrostatic forces. This study exhibits the potential of the RPDSAC as an adsorbent for removal of toxic cationic dye (MB) from contaminated wastewater.
    Matched MeSH terms: Methylene Blue*
  2. Rejected tea as a potential low-cost adsorbent for the removal of methylene blue
    Nasuha N, Hameed BH, Din AT
    J Hazard Mater, 2010 Mar 15;175(1-3):126-32.
    PMID: 19879046 DOI: 10.1016/j.jhazmat.2009.09.138
    The adsorption of methylene blue (MB) from aqueous solution using a low-cost adsorbent, rejected tea (RT), has been studied by batch adsorption technique. The adsorption experiments were carried out under different conditions of initial concentration (50-500 mg/L), solution pH 3-12, RT dose (0.05-1g) and temperature (30-50 degrees C). The equilibrium data were fitted to Langmuir and Freundlich isotherms and the equilibrium adsorption was best described by the Langmuir isotherm model with maximum monolayer adsorption capacities found to be 147, 154 and 156 mg/g at 30, 40 and 50 degrees C, respectively. Three kinetic models, pseudo-first-order, pseudo-second-order and intraparticle diffusion were employed to describe the adsorption mechanism. The experimental results showed that the pseudo-second-order equation is the best model that describes the adsorption behavior with the coefficient of correlation R(2)>or=0.99. The results suggested that RT has high potential to be used as effective adsorbent for MB removal.
    Matched MeSH terms: Methylene Blue/isolation & purification*; Methylene Blue/chemistry
  3. Adsorption of basic and reactive dyes from aqueous solution onto Intsia bijuga sawdust-based activated carbon: batch and column study
    Khasri A, Ahmad MA
    Environ Sci Pollut Res Int, 2018 Nov;25(31):31508-31519.
    PMID: 30203351 DOI: 10.1007/s11356-018-3046-3
    The adsorption behavior of basic, methylene blue (MB), and reactive, remazol brilliant violet 5R (RBV), dyes from aqueous solution onto Intsia bijuga sawdust-based activated carbon (IBSAC) was executed via batch and column studies. The produced activated carbon was characterized through Brunauer-Emmett-Teller (BET) surface area and pore structural analysis, proximate and ultimate, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). Batch studies were performed to investigate the effects of contact time, initial concentration, and solution pH. The equilibrium data for both MB and RBV adsorption better fits Langmuir model with maximum adsorption capacity of 434.78 and 212.77 mg/g, respectively. Kinetic studies for both MB and RBV dyes showed that the adsorption process followed a pseudo-second-order and intraparticle diffusion kinetic models. For column mode, the breakthrough curves were plotted by varying the flow rate, bed height, and initial concentration and the breakthrough data were best correlated with the Yoon-Nelson model compared to Thomas and Adams-Bohart model. The adsorption activity of IBSAC shows good stability even after four consecutive cycles.
    Matched MeSH terms: Methylene Blue/isolation & purification; Methylene Blue/chemistry
  4. Fulltext Modified microwave method for the synthesis of visible light-responsive TiO2/MWCNTs nanocatalysts
    Alosfur FK, Jumali MH, Radiman S, Ridha NJ, Yarmo MA, Umar AA
    Nanoscale Res Lett, 2013;8(1):346.
    PMID: 23919496 DOI: 10.1186/1556-276X-8-346
    Recently, TiO2/multi-walled carbon nanotube (MWCNT) hybrid nanocatalysts have been a subject of high interest due to their excellent structures, large surface areas and peculiar optical properties, which enhance their photocatalytic performance. In this work, a modified microwave technique was used to rapidly synthesise a TiO2/MWCNT nanocatalyst with a large surface area. X-ray powder diffraction, field-emission scanning electron microscopy, transmission electron microscopy and Brunauer-Emmett-Teller measurements were used to characterise the structure, morphology and the surface area of the sample. The photocatalytic activity of the hybrid nanocatalysts was evaluated through a comparison of the degradation of methylene blue dye under irradiation with ultraviolet and visible light. The results showed that the TiO2/MWCNT hybrid nanocatalysts degraded 34.9% of the methylene blue (MB) under irradiation with ultraviolet light, whereas 96.3% of the MB was degraded under irradiation with visible light.
    Matched MeSH terms: Methylene Blue
  5. Monsoonal variations in atmospheric surfactants at different coastal areas of the Malaysian Peninsula
    Jaafar SA, Latif MT, Razak IS, Shaharudin MZ, Khan MF, Wahid NBA, et al.
    Mar Pollut Bull, 2016 Aug 15;109(1):480-489.
    PMID: 27230987 DOI: 10.1016/j.marpolbul.2016.05.017
    This study determined the effect of monsoonal changes on the composition of atmospheric surfactants in coastal areas. The composition of anions (SO4(2-), NO3(-), Cl(-), F(-)) and the major elements (Ca, K, Mg, Na) in aerosols were used to determine the possible sources of surfactants. Surfactant compositions were determined using a colorimetric method as methylene blue active substances (MBAS) and disulphine blue active substances (DBAS). The anion and major element compositions of the aerosol samples were determined by ion chromatography (IC) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. The results indicated that the concentrations of surfactant in aerosols were dominated by MBAS (34-326pmolm(-3)). Monsoonal changes were found to significantly affect the concentration of surfactants. Using principal component analysis-multiple linear regressions (PCA-MLR), major possible sources for surfactants in the aerosols were motor vehicle emissions, secondary aerosol and the combustion of biomass along with marine aerosol.
    Matched MeSH terms: Methylene Blue
  6. Fulltext Antibacterial-Integrated Collagen Wound Dressing for Diabetes-Related Foot Ulcers: An Evidence-Based Review of Clinical Studies
    N Amirrah I, Mohd Razip Wee MF, Tabata Y, Bt Hj Idrus R, Nordin A, Fauzi MB
    Polymers (Basel), 2020 Sep 22;12(9).
    PMID: 32972012 DOI: 10.3390/polym12092168
    Diabetic foot ulcer (DFU) is a chronic wound frequently delayed from severe infection. Wound dressing provides an essential barrier between the ulcer and the external environment. This review aimed to analyse the effectiveness of antibacterial collagen-based dressing for DFU treatment in a clinical setting. An electronic search in four databases, namely, Scopus, PubMed, Ovid MEDLINE(R), and ISI Web of Science, was performed to obtain relevant articles published within the last ten years. The published studies were included if they reported evidence of (1) collagen-based antibacterial dressing or (2) wound healing for diabetic ulcers, and (3) were written in English. Both randomised and non-randomised clinical trials were included. The search for relevant clinical studies (n) identified eight related references discussing the effectiveness of collagen-based antibacterial wound dressings for DFU comprising collagen impregnated with polyhexamethylene biguanide (n = 2), gentamicin (n = 3), combined-cellulose and silver (n = 1), gentian violet/methylene blue mixed (n = 1), and silver (n = 1). The clinical data were limited by small sample sizes and multiple aetiologies of chronic wounds. The evidence was not robust enough for a conclusive statement, although most of the studies reported positive outcomes for the use of collagen dressings loaded with antibacterial properties for DFU wound healing. This study emphasises the importance of having standardised clinical trials, larger sample sizes, and accurate reporting for reliable statistical evidence confirming DFU treatment efficiency.
    Matched MeSH terms: Methylene Blue
  7. Fulltext Photocatalytic Properties of Graphene/Gold and Graphene Oxide/Gold Nanocomposites Synthesized by Pulsed Laser Induced Photolysis
    Chen LH, Shen HT, Chang WH, Khalil I, Liao SY, A Yehye W, et al.
    Nanomaterials (Basel), 2020 Oct 07;10(10).
    PMID: 33036455 DOI: 10.3390/nano10101985
    Graphene (Gr)/gold (Au) and graphene-oxide (GO)/Au nanocomposites (NCPs) were synthesized by performing pulsed-laser-induced photolysis (PLIP) on hydrogen peroxide and chloroauric acid (HAuCl4) that coexisted with Gr or GO in an aqueous solution. A 3-month-long aqueous solution stability was observed in the NCPs synthesized without using surfactants and additional processing. The synthesized NCPs were characterized using absorption spectroscopy, transmission electron microscopy, Raman spectroscopy, energy dispersive spectroscopy, and X-ray diffraction to prove the existence of hybrid Gr/Au or GO/Au NCPs. The synthesized NCPs were further evaluated using the photocatalytic reaction of methylene blue (MB), a synthetic dye, under UV radiation, visible light (central wavelength of 470 nm), and full spectrum of solar light. Both Gr/Au and GO/Au NCPs exhibited photocatalytic degradation of MB under solar light illumination with removal efficiencies of 92.1% and 94.5%, respectively.
    Matched MeSH terms: Methylene Blue
  8. Fulltext Highly Sensitive Fluorescence Sensor for Carrageenan from a Composite Methylcellulose/Polyacrylate Membrane
    Hassan RA, Heng LY, Tan LL
    Sensors (Basel), 2020 Sep 04;20(18).
    PMID: 32899886 DOI: 10.3390/s20185043
    Carrageenans are linear sulphated polysaccharides that are commonly added into confectionery products but may exert a detrimental effect to human health. A new and simpler way of carrageenan determination based on an optical sensor utilizing a methylcellulose/poly(n-butyl acrylate) (Mc/PnBA) composite membrane with immobilized methylene blue (MB) was developed. The hydrophilic Mc polymer membrane was successfully modified with a more hydrophobic acrylic polymer. This was to produce an insoluble membrane at room temperature where MB reagent could be immobilized to build an optical sensor for carrageenan analysis. The fluorescence intensity of MB in the composite membrane was found to be proportional to the carrageenan concentrations in a linear manner (1.0-20.0 mg L-1, R2 = 0.992) and with a detection limit at 0.4 mg L-1. Recovery of spiked carrageenan into commercial fruit juice products showed percentage recoveries between 90% and 102%. The optical sensor has the advantages of improved sensitivity and better selectivity to carrageenan when compared to other types of hydrocolloids. Its sensitivity was comparable to most sophisticated techniques for carageenan analysis but better than other types of optical sensors. Thus, this sensor provides a simple, rapid, and sensitive means for carageenan analysis.
    Matched MeSH terms: Methylene Blue
  9. Fulltext Simultaneous Adsorption of Cationic Dyes from Binary Solutions by Thiourea-Modified Poly(acrylonitrile-co-acrylic acid): Detailed Isotherm and Kinetic Studies
    Adeyi AA, Jamil SNAM, Abdullah LC, Choong TSY, Lau KL, Abdullah M
    Materials (Basel), 2019 Sep 08;12(18).
    PMID: 31500398 DOI: 10.3390/ma12182903
    In this study, simultaneous adsorption of cationic dyes was investigated by using binary component solutions. Thiourea-modified poly(acrylonitrile-co-acrylic acid) (TMPAA) polymer was used as an adsorbent for uptake of cationic dyes (malachite green, MG and methylene blue, MB) from aqueous solution in a binary system. Adsorption tests revealed that TMPAA presented high adsorption of MG and MB at higher pH and higher dye concentrations. It suggested that there are strong electrostatic attractions between the surface functional groups of the adsorbent and cationic dyes. The equilibrium analyses explain that both extended Langmuir and extended models are suitable for the description of adsorption data in the binary system. An antagonistic effect was found, probably due to triangular (MG) and linear (MB) molecular structures that mutually hinder the adsorption of both dyes on TMPAA. Besides, the kinetic studies for sorption of MG and MB dyes onto adsorbent were better represented by a pseudo-second-order model, which demonstrates chemisorption between the polymeric TMPAA adsorbent and dye molecules. According to experimental findings, TMPAA is an attractive adsorbent for treatment of wastewater containing multiple cationic dyes.
    Matched MeSH terms: Methylene Blue
  10. Fulltext Needle Aspiration and Cytology for Suspected Osteoarticular Tuberculosis in Children
    Agarwal A, Singh S, Agarwal S, Gupta S
    Malays Orthop J, 2018 Nov;12(3):31-37.
    PMID: 30555644 DOI: 10.5704/MOJ.1811.007
    Introduction: Early diagnosis of osteoarticular tuberculosis (OATB) is essential to prevent significant functional disability. There is no single test for diagnosis. Despite an array of investigations available, definitive diagnosis at early stage before starting antitubercular drugs is still a challenge. Materials and Methods: A cross sectional study was carried out between February 2016 and October 2017. All children less than 18 years of age with suspected osteoarticular tuberculosis were included. The cases were subjected to simple needle aspiration from whichever site was accessible. Multiple sample aspirations were done at site of involvement. Smears were prepared from the aspirated material. Results: Ziehl-Neelsen staining for Acid Fast Bacilli (AFB) showed deep pink red rods under light microscopy. Features suggestive of tuberculosis can be seen by May-Grünwald-Giemsa (MGG) staining. Auramine-O staining method of detecting AFB under fluorescent microscope shows the bacilli as greenish yellow slender curved rods in dark background. Fluorescent microscopy has higher sensitivity and comparable specificity. In our study, microbiological confirmation of OATB could be done in 100% cases where the lesion could be accessed for aspiration. The molecular techniques are relatively more expensive and not available everywhere. Conclusion: Meticulous search for AFB in a well stained smear using three different staining methods provides a direct evidence of infection over costly imaging especially in poor patients seen in resource limited settings.
    Matched MeSH terms: Methylene Blue
  11. Experimental and first-principles DFT studies on the band gap behaviours of microsized and nanosized Zn(1-x)MnxO materials
    Kasim MF, Darman AKAB, Yaakob MK, Badar N, Kamarulzaman N
    Phys Chem Chem Phys, 2019 Sep 11;21(35):19126-19146.
    PMID: 31432825 DOI: 10.1039/c9cp01664c
    In this study, nano- and microsized zinc oxide (ZnO) materials were doped with different manganese (Mn) contents (1-5 mol%) via a simple sol-gel method. The structural, morphological, optical and chemical environments of the materials were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), UV-visible spectroscopy (UV-vis) and X-ray photoelectron spectroscopy (XPS). XRD results revealed that all synthesised materials were pure and single phased with a hexagonal wurtzite structure of ZnO. However, at a low annealing temperature, a nanorod-like shape can be obtained for all Zn(1-x)MnxO materials. In addition, EDX spectra confirmed the presence of Mn in the ZnO lattice and the atomic percentage was nearly equal to the calculated stoichiometry. UV-vis spectroscopy further revealed that materials in nano size exhibited band gap widening with an increase of the Mn content in the ZnO lattice. In contrast, micron state materials exhibited band gap narrowing with increasing Mn content up to 3% and then begin to widen when Mn > 3%. This is because the band gaps of these materials are affected by the dimensions of the crystals and the Mn content in the materials. Furthermore, XPS results revealed the existence of multiple states of Mn in all synthesised materials. By combining the information obtained from UV-vis and the XPS valence band, shifting in the valence band maximum (VBM) and conduction band minimum (CBM) was observed. Based on XPS results, the calculation of density functional theory studies revealed that the presence of Mn2+, Mn3+, and Mn4+ ions in the materials influences the band gap changes. It was also revealed that the nanosized Zn0.99Mn0.01O exhibited a higher photocatalytic activity than the other samples for degrading methylene blue (MB) dyes, owing to its smallest crystallite size.
    Matched MeSH terms: Methylene Blue
  12. Fulltext Staple-line leak post primary sleeve gastrectomy. A two patient case series and literature review
    Loo GH, Rajan R, Nik Mahmood NRK
    Ann Med Surg (Lond), 2019 Aug;44:72-76.
    PMID: 31321031 DOI: 10.1016/j.amsu.2019.06.014
    There is an increasing trend in the number of bariatric surgeries performed worldwide, partly because bariatric surgery is the most effective treatment for morbid obesity. Sleeve gastrectomy (SG) remains the most common bariatric surgery procedure performed, representing more than 50% of all primary bariatric interventions. Major surgical complications of SG include staple-line bleeding, leaking, and stenosis. A leak along the staple-line most commonly occurs at the gastroesophageal junction (GOJ). From January 2018 to December 2018, our centre performed 226 bariatric procedures, of which, 97.8% were primary bariatric procedures. The mean age and BMI were 38.7±8.3 years and 44 kg/m2, respectively. Out of the 202 primary SG performed, we encountered two cases of a staple-line leak (0.99%). This is the first reported case series of SG leaks from the Southeast Asia region. A summary of their characteristics, clinical presentation, subsequent management, and the outcome is discussed. Based on the latest available evidence from the literature, several methods may decrease staple-line leaks in SG. These include the use of a bougie size greater than 40 Fr, routine use of methylene blue test during surgery, beginning transection at 2-6 cm from the pylorus, mobilising the fundus before transection, and staying away from the GOJ at the last firing. Other methods include the proper alignment of the staple-line, control of staple-line bleeding, and performing staple-line reinforcement. The management of a staple-line leak remains challenging due to limited systematic, evidence-based literature being available. Therefore, a tailored approach is needed to manage this complication.
    Matched MeSH terms: Methylene Blue
  13. Fulltext A simple, portable, electrochemical biosensor to screen shellfish for Vibrio parahaemolyticus
    Nordin N, Yusof NA, Abdullah J, Radu S, Hushiarian R
    AMB Express, 2017 Dec;7(1):41.
    PMID: 28205102 DOI: 10.1186/s13568-017-0339-8
    An earlier electrochemical mechanism of DNA detection was adapted and specified for the detection of Vibrio parahaemolyticus in real samples. The reader, based on a screen printed carbon electrode, was modified with polylactide-stabilized gold nanoparticles and methylene blue was employed as the redox indicator. Detection was assessed using a microprocessor to measure current response under controlled potential. The fabricated sensor was able to specifically distinguish complementary, non-complementary and mismatched oligonucleotides. DNA was measured in the range of 2.0 × 10(-8)-2.0 × 10(-13) M with a detection limit of 2.16 pM. The relative standard deviation for 6 replications of differential pulse voltammetry (DPV) measurement of 0.2 µM complementary DNA was 4.33%. Additionally, cross-reactivity studies against various other food-borne pathogens showed a reliably sensitive detection of the target pathogen. Successful identification of Vibrio parahaemolyticus (spiked and unspiked) in fresh cockles, combined with its simplicity and portability demonstrate the potential of the device as a practical screening tool.
    Matched MeSH terms: Methylene Blue
  14. In-vitro evaluation of microleakage of bioceramic root-end filling materials: A spectrophotometric study
    Gupta R, Kewalramani R
    J Oral Biol Craniofac Res, 2021 03 10;11(2):330-333.
    PMID: 33786296 DOI: 10.1016/j.jobcr.2021.03.001
    Aim: To evaluate the microleakage of newer bioceramic root-end filling materials.

    Material and method: Sixty freshly extracted human single-rooted mandibular premolar teeth were selected for the study. Teeth with fractured root, cracks, anddilacerations were rejected. All teeth were cleaned with ultrasonic scalers. Standard access opening was done and root canal treatment was performed with rotary files followed by obturation. After storing in saline for a week apical 3 ​mm of the root was resected at 900 angles to the long axis of the root. Retro cavity preparation was done with ultrasonic tips. The teeth were divided into four groups of 15 specimens each. Group I - Biodentin, GroupII-Bioaggregate, Group III - MTA Plus, and Group IV - MTA. After the restoration of retro cavities of all the teeth as per manufacture instructions, two coats of nail varnish were applied to leave apical 3 ​mm. All teeth were stored in 2% methylene blue for 72 ​h followed by emersion in 65% nitric acid for the next 72 ​h for Dye extraction. The obtained supernatant solution was then centrifuged and optical density or absorbance was measured with a UV spectrophotometer.

    Result: Microleakage was found to be increasing in this order: Biodentin ​ ​0.01).

    Conclusion: All materials exhibit some amount of microleakage. Biodentin shows the least microleakage among all the bioceramic material groups. Hence, Biodentin and bioaggregate are better material of choice for the retrograde filling to prevent microleakage.

    Matched MeSH terms: Methylene Blue
  15. First Report of Soft Rot Disease Caused by Pectobacterium wasabiae on Sweet Potato, Tomato, and Eggplant in Malaysia
    Golkhandan E, Kamaruzaman S, Sariah M, Abidin MAZ, Nazerian E, Yassoralipour A
    Plant Dis, 2013 May;97(5):685.
    PMID: 30722205 DOI: 10.1094/PDIS-08-12-0759-PDN
    In August 2011, sweet potato (Ipomoea batatas), tomato (Solanum lycopersicum), and eggplant (S. melongena) crops from major growing areas of the Cameron highlands and Johor state in Malaysia were affected by a soft rot disease. Disease incidence exceeded 80, 75, and 65% in severely infected fields and greenhouses of sweet potato, tomato, and eggplant, respectively. The disease was characterized by dark and small water-soaked lesions or soft rot symptoms on sweet potato tubers, tomato stems, and eggplant fruits. In addition, extensive discoloration of vascular tissues, stem hollowness, and water-soaked, soft, dark green lesions that turned brown with age were observed on the stem of tomato and eggplant. A survey was performed in these growing areas and 22 isolates of the pathogen were obtained from sweet potato (12 isolates), tomato (6 isolates), and eggplant (4 isolates) on nutrient agar (NA) and eosin methylene blue (EMB) (4). The cultures were incubated at 27°C for 2 days and colonies that were emerald green on EMB or white to gray on NA were selected for further studies. All bacterial cultures isolated from the survey exhibited pectolytic ability on potato slices. These bacterial isolates were gram negative; rod shaped; N-acetylglucosaminyl transferase, gelatin liquefaction, and OPNG positive; and were also positive for acid production from D-galactose, lactosemelibiose, raffinose, citrate, and trehalose. They were negative for indol production, phosphatase activity, reducing substances from sucrose, and negative for acid production from maltose, sorbitol, inositol, inolin, melezitose, α-mathyl-D-glocoside, and D-arabitol. The bacteria did not grow on NA at 37°C. Based on these biochemical and morphological assays, the pathogen was identified as Pectobacterium wasabiae (2). In addition, DNA was extracted and PCR assay with two primers (16SF1 and 16SR1) was performed (4). Partial sequences of 16S rRNA (GenBank Accession Nos. JQ665714, JX494234, and JX513960) of sweet potato, tomato, and eggplant, respectively, exhibited a 99% identity with P. wasabiae strain SR91 (NR_026047 and NR_026047.1). A pathogenicity assay was carried out on sweet potato tubers (cv. Oren), tomato stems (cv. 152177-A), and eggplant fruits (cv. 125066x) with 4 randomly representative isolates obtained from each crop. Sweet potato tubers, tomato stems, and eggplant fruits (4 replications) were sanitized in 70% ethyl alcohol for 30 s, washed and rinsed in sterile distilled water, and needle punctured with a bacterial suspension at a concentration of 108 CFU/ml. Inoculated tubers, stems, and fruits were incubated in a moist chamber at 90 to 100% RH for 72 h at 25°C when lesions were measured. All inoculated tubers, stems, and fruits exhibited soft rot symptoms after 72 h similar to those observed in the fields and greenhouses and the same bacteria were consistently reisolated. Symptoms were not observed on controls. The pathogenicty test was repeated with similar results. P. wasabiae have been previously reported to cause soft rot on Japanese horseradish (3), and aerial stem rot on potato in New Zealand (4), the U.S. (2), and Iran (1). To our knowledge, this is the first report of sweet potato, tomato, and eggplant soft rot caused by P. wasabiae in Malaysia. References: (1) S. Baghaee-Ravari et al. Eur. J. Plant Pathol. 129:413, 2011. (2) S. De Boer and A. Kelman. Page 56 in: Laboratory Guide for Identification of Plant Pathogenic Bacteria, 3rd ed. N. Schaad et al., eds. APS Press, St. Paul, 2001. (3) M. Goto et al. Int. J. Syst. Bacteriol. 37:130, 1987. (4) A. R. Pitman et al. Eur. J. Plant Pathol. 126:423, 2010.
    Matched MeSH terms: Methylene Blue
  16. Antihypertensive activity and vascular reactivity mechanisms of Vitex pubescens leaf extracts in spontaneously hypertensive rats
    Al-Akwaa AA, Asmawi MZ, Dewa A, Mahmud R
    Heliyon, 2020 Jul;6(7):e04588.
    PMID: 32775735 DOI: 10.1016/j.heliyon.2020.e04588
    Background: Vitex pubescens has been used traditionally in hypertension treatment but not yet scientifically assessed. The objective of the study is to investigate the antihypertensive and vasorelaxant activities of V. pubescens, study its underlying pharmacological mechanisms, and identify the relevant vasoactive compounds.

    Methods: Successive extractions of V. pubescens leaf were carried out to produce petroleum ether (VPPE), chloroform (VPCE), methanol (VPME), and water (VPWE) extracts. Spontaneously hypertensive rats (SHRs) received a daily oral administration of the extracts (500 mg/kg/day; n = 6) or verapamil (15 mg/kg/day; n = 6) for 2 weeks, while the systolic and diastolic blood pressures were measured using non-invasive tail-cuff method. Vasorelaxation assays of the extracts were later conducted using phenylephrine (PE, 1 μM) pre-contracted aortic ring preparation. Mechanisms of vasorelaxation by the most potent fraction were studied using vasorelaxation assays with selected blockers/inhibitors. GC-MS was conducted to determine the active compounds.

    Results: VPPE elicited the most significant diminution in systolic and diastolic blood pressure of treated SHRs and produced the most significant vasorelaxation in the aortic rings. Vasorelaxant effects of F2-VPPE were significantly reduced in endothelium-denuded aortic rings by glibenclamide (1 μM), whereas calcium chloride and PE-induced contractions were significantly suppressed. Endothelium removal of the aortic rings or incubation with indomethacin (10 μM), atropine (1 μM), methylene blue (10 μM), propranolol (1μM) and L-NAME (10 μM) did not significantly alter F2-VPPE-induced vasorelaxation. Seven compounds were identified using GC-MS, including spathulenol.

    Conclusion: F2-VPPE exerted its endothelium-independent vasorelaxation by inhibition of vascular smooth muscle contraction induced by extracellular Ca+2 influx through trans-membrane Ca+2 channels and/or Ca+2 release from intracellular stores, and by activation of KATP channels. The vasorelaxation effects of V. pubescens could be mediated by the compound, spathulenol.

    Matched MeSH terms: Methylene Blue
  17. 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: Methylene Blue
  18. Fulltext SYNTHESIS AND CHARACTERIZATION OF TiO2/ZnO-EPOXY BEADS AND THEIR PERFORMANCE FOR THE DEGRADATION OF DYE
    MOHAMAD HANIF AKMAL HUSSIN, WAN RAFIZAH WAN ABDULLAH, MOHAMAD AWANG
    UMT Journal of Undergraduate Research, 2020;2(2):9-14.
    MyJurnal
    Semiconductor oxides such as titanium dioxide (TiO2) and zinc oxide (ZnO) are used as the photocatalyst for removing contaminants. In addition, TiO2 and ZnO nanoparticles in the suspension form makes it difficult to be recovered and recycled. This study was conducted to investigate the efficiency of immobilizing TiO2 and ZnO nanoparticles in epoxy beads. The immobilization process using different ratios of photocatalysts TiO2/ZnO (1:0, 3:1, 1:1, 1:3 and 0:1) fixed on epoxy material. These epoxy beads were used for dye removal in photocatalysis using methylene blue (MB) solution at a concentration of 10mg/L. Besides, epoxy beads also characterized using scanning electron microscope (SEM), attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy and thermogravimetric analysis (TGA). The results showed that the highly recommended epoxy bead is 3:1 ratio of TiO2/ZnO because it has good performance in dye degradation that proved from reducing concentration of MB to 2.4mg/L (76%). However, TiO2/ZnO characterization of 3:1 by SEM show on the surface the particle are found to be spherical in shape which is relatively high efficiency for the degradation, ATR-FTIR pattern in broad band 4000 cm-1 - 400cm-1 which correspond to hydroxyl stretching to be adsorbed at peak (474.49 cm-1 - 3722.61cm-1) respectively to the optimum for the degradation and TGA rate of change are 5mg to 2.5mg that residue (49.78%) due to decomposition or oxidation from mass loss. These findings are very effective and economical technique to be cost saving and highly efficient photocatalyst.
    Matched MeSH terms: Methylene Blue
  19. Fulltext SOLAR PHOTOCATALYTIC EFFICIENCY OF ZINC OXIDE FOR WATER DECONTAMINATION
    FARAH EILYANA MOHAMED
    UMT Journal of Undergraduate Research, 2019;1(1):92-102.
    MyJurnal
    Solar photocatalysis is a green technology that takes advantage of sustainable solar energy for enhancing oxidation process of numerous harmful water contaminants. In this study, a custom solar driven zinc oxide (ZnO)-mediated photocatalytic system was developed and its efficiency to remove organic contaminants as well as to disinfect selected bacteria was investigated. Methylene blue (MB) dye was used as the model organic contaminant, while Escherichia coli(E.coli) was used as the model fecal coliform bacteria in contaminated water. A series of photodegradation experiments were conducted on water contaminated with either 10 mg/L of MB or ~1010CFU/ml of E.coli. The experiments were completed under sunlight irradiation in the presence of 1 g/L of nano ZnO photocatalyst for up to 6 hours. Using a solar thermal collector, the photoreactor operated in the temperature range of 25 to 50 oC. The findings revealed that the combination of solar thermal with solar photocatalysis usingZnO intensified the degradation of MB and disinfection of E.coli. 98.08% of MB dye and 99.99% of E.coliwere successfully removed from the water within the first 3 hours of treatment. Almost complete removal was eventually achieved after 6 hours of treatment. It is therefore suggested that ZnO-based solar photocatalytic system developed in this study is highly efficient at enhancing water decontamination process.
    Matched MeSH terms: Methylene Blue
  20. 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: Methylene Blue
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