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Sample records for bacitracin methylene disalicylate

  1. 76 FR 53050 - New Animal Drugs; Ampicillin Trihydrate, Bacitracin Methylene Disalicylate, Flunixin...

    Science.gov (United States)

    2011-08-25

    ... Trihydrate, Bacitracin Methylene Disalicylate, Flunixin, Gonadotropin Releasing Factor Analog-Diphtheria.... Revise Sec. 520.970 to read as follows: Sec. 520.970 Flunixin. (a) Specifications. (1) Each 10-gram (g) packet of granules contains flunixin meglumine equivalent to 250 milligrams (mg) of flunixin. (2) Each...

  2. Response of broiler chickens to addition of bacitracin methylene disalicylate and roxarsone to diets containing halofuginone.

    Science.gov (United States)

    Waldroup, P W; Hellwig, H M; Johnson, Z B; Fell, R V; Grant, R J; Damron, B L; Hebert, J A; Siccardi, F J; Primo, R A

    1987-10-01

    Studies were conducted at six locations over a 7-yr period to evaluate the response of broiler chickens to bacitracin methylene disalicylate (BMD) and roxarsone in the presence of diets containing 3 ppm halofuginone/kg feed. Treatments consisted of a 2 x 2 factorial arrangement with 0 or 55 mg BMD and 0 or 50 mg roxarsone/kg feed. These additives were fed beginning with day-old chicks and were removed 6 days before termination of the study, which varied in length from 48 to 56 days among locations. Body weights were significantly improved (P less than .05) by the addition of either BMD or roxarsone with a significant interaction (P less than .05) between BMD and roxarsone. Roxarsone improved body weights only in the presence of BMD. Feed utilization was significantly (P less than .05) improved by addition of either BMD or roxarsone, with no interaction between the two products.

  3. Effect of roxarsone and bacitracin methylene disalicylate on the development of immunity to Eimeria in broilers given a live coccidiosis vaccine.

    Science.gov (United States)

    Chapman, H D; Fitzcoy, S H

    1996-12-01

    No significant differences in the BW, feed intake, feed conversion, or mortality of broilers that had been vaccinated at 3 d of age with a live coccidiosis vaccine were observed irrespective of whether they had been given roxarsone, bacitracin methylene disalicylate, or both drugs in the feed. The weight gain of birds challenged with a high dose of the vaccine at 51 d was not significantly different from that of unchallenged birds and no lesions of Eimeria species were found in their intestines irrespective of the medication given. It is concluded that roxarsone and bacitracin methylene disalicylate do not interfere with the acquisition of immunity to Eimeria species in broilers.

  4. Response of broiler chickens to dietary supplementation with roxarsone and bacitracin methylene disalicylate in diets containing narasin.

    Science.gov (United States)

    Waldroup, P W; Hellwig, H M; Johnson, Z B; Krueger, W F; Moore, R W; Charles, O W; Duke, S; Primo, R A; Trammell, J H; Fell, R V

    1988-01-01

    Six trials were conducted at different locations to examine the response of broiler chickens to roxarsone and bacitracin in the form of bacitracin methylene disalicylate (BMD) in the presence of the anticoccidal narasin. All diets contained narasin (80 mg/kg) and were fortified with a factorial arrangement of roxarsone (0 to 50 mg/kg) and BMD (0 or 55 mg/kg). Broilers were grown to market weights with narasin and roxarsone removed from the diets for the final 5 days. Addition of both roxarsone and BMD resulted in significant (P less than .05) improvements in body weight and feed utilization. Response to roxarsone for feed utilization was influenced to some extent by the presence or absence of BMD. Although the response to roxarsone was always positive, the degree of response was lessened by the presence of BMD. This resulted in a significant (P less than .10) interaction between roxarsone and BMD for feed utilization but not for body weight.

  5. Comparative Efficacy of an Organic Acid Blend and Bacitracin Methylene Disalicylate as Growth Promoters in Broiler Chickens: Effects on Performance, Gut Histology, and Small Intestinal Milieu

    Directory of Open Access Journals (Sweden)

    Saikat Samanta

    2010-01-01

    Full Text Available This study evaluated the efficacy of organic acids as a growth promoter for broiler chickens relative to antibiotic growth promoters (AGPs. Broiler chickens were supplemented with graded doses of an organic acid blend (OAB, 1 g and 2 g/kg diet and bacitracin methylene disalicylate (BMD, 0.5 g and 1 g/kg diet for 35 days. Supplementation of OAB improved (<.001 feed conversion ratio (FCR and increased protein accretion (<.001. Dietary acidification caused pH of the gizzard to decline linearly (<.01 with the dose of supplemental OAB. In the lower intestine, pH remained unaffected by dietary treatments. Unlike BMD, supplemental OAB selectively promoted growth of lactobacilli in the small intestine. Moreover, compared to BMD, OAB tended to maintain the villi in the small intestine at a greater height. Although benefits of exceeding the dose of supplemental organic acids more than 1 g/kg diet are not always conspicuous, based on the live weight and feed conversion data, supplementation of 2 g organic acid per kg diet may be recommended for total replacement of AGPs in broiler diet.

  6. Comparative efficacy of a yeast product and bacitracin methylene disalicylate in enhancing early growth and intestinal maturation in broiler chicks from breeder hens of different ages.

    Science.gov (United States)

    Fasina, Y O; Thanissery, R R

    2011-05-01

    The intestine of the newly hatched chick is immature at hatch. Yeast contains nucleotides and β-glucans that enhance intestinal development and chick growth. Accordingly, a 14-d experiment was conducted to evaluate the efficacy of a novel yeast product and bacitracin methylene disalicylate in enhancing early growth and intestinal maturation in chicks obtained from young (26-27 wk old) and old (58 to 59 wk old) breeder hens. Chicks (384) were randomly assigned to 8 dietary treatments. Treatment 1 (YH) consisted of chicks, from young hens, fed corn-soybean meal (SBM) diet alone. Treatment 2 (YHB) consisted of chicks, from young hens, fed corn-SBM basal into which BMD was added at 0.055 g/kg. Treatment 3 (YHE) consisted of chicks, from young hens, fed corn-SBM basal into which yeast extract (YE) was added at 0.075% level. Treatment 4 (YHED) consisted of chicks, from young hens, fed corn-SBM basal into which YE was added at 0.15% level. Treatments 5 (OH), 6 (OHB), 7 (OHE), and 8 (OHED) consisted of chicks from old hens fed diets similar to those given to YH in treatments 1, 2, 3, and 4, respectively. Growth performance (body weight gain and feed conversion ratio) was evaluated on d 7 and 14. Intestinal tissue samples were also analyzed for alkaline phosphatase (ALP) activity as an indicator of intestinal maturation on d 4 and 13 of experiment. Results showed that by d 14 of experiment, only BMD treatments (YHB and OHB) improved body weight gain (P yeast-supplemented treatments (YHE, YHED, OHE, and OHED) were statistically similar (P > 0.05) to those of the BMD treatments. Ileal ALP activity was consistently enhanced by BMD and yeast product supplemented at 0.075% of the diet. It was concluded that antibiotic BMD and our novel yeast product supplemented at 0.075% of the diet improved early chick growth and maturation of the ileal segment of the small intestine.

  7. 21 CFR 558.76 - Bacitracin methylene disalicylate.

    Science.gov (United States)

    2010-04-01

    .... (b) Special considerations. The quantities of antibiotics are expressed in terms of the equivalent amount of antibiotic standard. (c) Related tolerances. See § 556.70 of this chapter. (d) Conditions of... gramsper ton Indications for use Limitations Sponsor (i) 4 to 50 Chickens, turkeys, and...

  8. Effects of an Ionophore Coccidiostat (Monensin or Salinomycin, Sodium or Potassium Bicarbonate, or Both, and Bacitracin Methylene Disalicylate in Broiler Chicken Diets

    Directory of Open Access Journals (Sweden)

    Hooge DM

    2000-01-01

    Full Text Available Peterson x Arbor Acres chicks were grown on used litter to 45 or 46 days of age in three pen trials. Coccidial inoculations were given by water at 14 days of age. Sodium bicarbonate (SBC; 0.20% or potassium bicarbonate (PBC; 0.14% was added to broiler chicken diets containing monensin (MON; 110 mg/kg or salinomycin (SAL; 66 mg/kg in Experiment 1. In Experiment 2, using SAL (55 mg/kg, three dietary bicarbonate treatments (SBC, 0.20%; PBC, 0.20%; or SBC + PBC 0.10% each were tested with or without BMD R (55 mg/kg. Diets differing in SAL, BMD R, and SBC levels were evaluated in Experiment 3. Beneficial interaction was found between ionophores and bicarbonates for mortality (lower when SBC or PBC and MON in Experiment 1. For main effects, in Experiment 1 PBC with MON or SAL improved body weight, feed conversion ratio and mortality. SAL improved weight, feed conversion ratio and mortality compared to MON. In Experiment 2, PBC with SAL improved weight, coccidial lesion score, feed conversion ratio and mortality across two levels of BMD R. The PBC and SBC were equally effective in Experiment 1, but PBC was about 0 to 40% as effective as SBC, depending on parameter in Experiment 2. Half levels of SBC plus PBC generally gave intermediate results between control and SBC. SBC with MON or SAL lowered mortalities, coccidial lesion scores, and feed conversion ratios (Experiments 1 and 2, and increased body weight (Experiment 2. In Experiment 3, BMD R in all feeds improved body weight and feed conversion versus in starter feed only, and SBC with SAL and BMD R improved all performance parameters.

  9. Bacitracin Ophthalmic

    Science.gov (United States)

    ... hands thoroughly with soap and water. Use a mirror or have someone else apply the ointment. Avoid ... or do not go away: itching, stinging, or burning of the eye Bacitracin eye ointment may cause ...

  10. Neomycin, Polymyxin, and Bacitracin Topical

    Science.gov (United States)

    Neomycin, polymyxin, and bacitracin combination is used to prevent minor skin injuries such as cuts, scrapes, and burns from becoming infected. Neomycin, polymyxin, and bacitracin are in a class of ...

  11. 21 CFR 558.55 - Amprolium.

    Science.gov (United States)

    2010-04-01

    ... (air-sac infection) and blue comb (nonspecific infectious enteritis) As bacitracin methylene... aid in the control of necrotic enteritis caused or complicated by Clostridium spp. or other organisms... infectious enteritis) As bacitracin methylene disalicylate, or zinc bacitracin Chlortetracycline 100 to...

  12. 21 CFR 558.78 - Bacitracin zinc.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Bacitracin zinc. 558.78 Section 558.78 Food and... in Animal Feeds § 558.78 Bacitracin zinc. (a) Specifications. Type A medicated articles containing bacitracin zinc equivalent to 10, 25, 40, or 50 grams per pound bacitracin. (b) Approvals. See No. 046573...

  13. 21 CFR 558.274 - Hygromycin B.

    Science.gov (United States)

    2010-04-01

    ... (airsac infection), blue comb (nonspecific infectious enteritis) As bacitracin methylene disalicylate or... infection), blue comb (nonspecific infectious enteritis) Feed containing not less than 25% of penicillin... respiratory disease (airsac infection), blue comb (nonspecific infectious enteritis) Combination...

  14. 21 CFR 556.70 - Bacitracin.

    Science.gov (United States)

    2010-04-01

    ... Residues of New Animal Drugs § 556.70 Bacitracin. (a) Acceptable daily intake (ADI). The ADI for total residues of bacitracin is 0.05 milligram per kilogram of body weight per day. (b) Tolerances. The tolerance... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Bacitracin. 556.70 Section 556.70 Food and...

  15. 21 CFR 524.154 - Bacitracin or bacitracin zinc-neomycin sulfate-polymyxin B sulfate ophthalmic ointment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Bacitracin or bacitracin zinc-neomycin sulfate... TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.154 Bacitracin or bacitracin zinc-neomycin sulfate-polymyxin B...: (1) To 000009; each gram contains 500 units of bacitracin, 3.5 milligrams of neomycin, and...

  16. 21 CFR 558.265 - Halofuginone hydrobromide.

    Science.gov (United States)

    2010-04-01

    ...) plus bacitracin methylene disalicylate 10 to 50 grams and roxarsone 22.7 to 45.4 grams. (A) Indications... grams plus roxarsone, 22.7 to 45.4 grams. (A) Indications for use. For the prevention of coccidiosis... hydrobromide, 2.72 grams plus roxarsone, 22.7 to 45.4 grams. (A) Indications for use. For the prevention...

  17. 21 CFR 520.154c - Bacitracin zinc soluble powder.

    Science.gov (United States)

    2010-04-01

    ... drinking water. (A) Indications for use. Prevention of necrotic enteritis caused by Clostridium perfringens... milligrams per gallon in drinking water. (A) Indications for use. Control of necrotic enteritis caused by... enteritis caused by Clostridium spp. susceptible to bacitracin zinc. (iii) Limitations. Prepare a...

  18. Photooxidation of the Antimicrobial, Nonribosomal Peptide Bacitracin A by Singlet Oxygen under Environmentally Relevant Conditions.

    Science.gov (United States)

    Lundeen, Rachel A; Chu, Chiheng; Sander, Michael; McNeill, Kristopher

    2016-08-16

    Bacitracin is a mixture of nonribosomal peptides (NRPs) that is extensively used as an antibiotic in both human and veterinary medicine. Despite its widespread use over the past six decades, very few studies have addressed the environmental fate of bacitracin and zinc-bacitracin complexes. In this study, the photochemical transformation of bacitracin components (i.e., cyclic dodecapeptides) in the aquatic environment was investigated. A high resolution mass spectrometry (HRMS)-based approach enabled monitoring of the photochemical degradation kinetics of individual bacitracin components, investigation of the relative contribution of reactive oxygen species (e.g., singlet oxygen, (1)O2) in dissolved organic matter-sensitized photoreactions, and identification of oxidative modifications in bacitracin photoproducts. The results of this study support the hypothesis that indirect photochemical oxidation of the histidine (His) residue by (1)O2 is a major degradation pathway for bacitracin A, the most potent congener of the mixture. Furthermore, the photooxidation rate of bacitracin A with (1)O2 decreased upon bacitracin A coordination with Zn(2+), demonstrating that the photochemistry of metal-bound His is different from that of metal-free His. Overall, these results provide insight into the fate of bacitracin components in the aquatic environment and highlight the potential of utilizing this HRMS-based methodology to study transformations of other environmentally relevant NRPs.

  19. Characterization of genes encoding for acquired bacitracin resistance in Clostridium perfringens.

    Directory of Open Access Journals (Sweden)

    Audrey Charlebois

    Full Text Available Phenotypic bacitracin resistance has been reported in Clostridium perfringens. However, the genes responsible for the resistance have not yet been characterized. Ninety-nine C. perfringens isolates recovered from broilers and turkeys were tested for phenotypic bacitracin resistance. Bacitracin MIC(90 (>256 µg/ml was identical for both turkey and chicken isolates; whereas MIC(50 was higher in turkey isolates (6 µg/ml than in chicken isolates (3 µg/ml. Twenty-four of the 99 isolates showed high-level bacitracin resistance (MIC breakpoint >256 µg/ml and the genes encoding for this resistance were characterized in C. perfringens c1261_A strain using primer walking. Sequence analysis and percentages of amino acid identity revealed putative genes encoding for both an ABC transporter and an overproduced undecaprenol kinase in C. perfringens c1261_A strain. These two mechanisms were shown to be both encoded by the putative bcrABD operon under the control of a regulatory gene, bcrR. Efflux pump inhibitor thioridazine was shown to increase significantly the susceptibility of strain c1261_A to bacitracin. Upstream and downstream from the bcr cluster was an IS1216-like element, which may play a role in the dissemination of this resistance determinant. Pulsed-field gel electrophoresis with prior double digestion with I-CeuI/MluI enzymes followed by hybridization analyses revealed that the bacitracin resistance genes bcrABDR were located on the chromosome. Semi-quantitative RT-PCR demonstrated that this gene cluster is expressed under bacitracin stress. Microarray analysis revealed the presence of these genes in all bacitracin resistant strains. This study reports the discovery of genes encoding for a putative ABC transporter and an overproduced undecaprenol kinase associated with high-level bacitracin resistance in C. perfringens isolates from turkeys and broiler chickens.

  20. RECOVERY OF MURINE MYELOPOIESIS AFTER CYTOSTATIC REDUCTION BY ARA-C - EFFECT OF BACITRACIN-INDUCED CHANGES IN THE INTESTINAL MICROFLORA AND INFLUENCE OF TIMING

    NARCIS (Netherlands)

    DAENEN, S; GORIS, H; DEBOER, F; HALIE, MR; VANDERWAAIJ, D

    1991-01-01

    The influence of intestinal flora modulation by oral bacitracin on the recovery of myelopoiesis after Ara-C was studied in C3H/Law mice. Bacitracin resulted in a 3-5 log increase of Gram-negative bacteria and a 10-fold increase of the intestinal endotoxin concentration. Initiation of bacitracin befo

  1. The effect of zinc bacitracin and roxarsone on performance of broiler chickens when fed in combination with narasin.

    Science.gov (United States)

    Waldroup, P W; Izat, A L; Primo, R A; Twining, P F; Herbert, J A; Trammell, J H; Fell, R V; Crawford, J S

    1990-06-01

    Six trials were conducted at various locations to determine the response of broiler chickens to combinations of zinc bacitracin and roxarsone when fed in the presence of narasin. The addition of zinc bacitracin at 55 mg per kg significantly improved growth rate and feed utilization when data from all locations were combined. There was no effect of roxarsone fed at 50 mg per kg on BW or feed utilization, nor was there an interaction of roxarsone and zinc bacitracin on BW. There was a significant interaction of roxarsone and zinc bacitracin for feed utilization; addition of zinc bacitracin significantly improved feed utilization both in the presence and absence of roxarsone, but the improvement was greater in the absence of roxarsone.

  2. Determination of neomycin and bacitracin in human or rabbit serum by HPLC-MS/MS.

    Science.gov (United States)

    Mascher, Daniel G; Unger, Christian P; Mascher, Hermann J

    2007-01-17

    The method for the simultaneous determination of neomycin and bacitracin in human or rabbit serum was developed by using ion pairing reversed phase chromatography and tandem mass spectrometry (MS/MS) detection with electrospray (ESI) in positive mode. Both substances elute under these conditions at the same time and also kanamycin as internal standard elutes almost at the same time. The sample preparation was simple-only using 0.1 mL serum by protein precipitation with acetonitrile. Neomycin and bacitracin were detected as two-fold charged ions as well as the internal standard. The calibration range of these quite difficult detectable substances was 0.2-50 microg/mL of serum. The method was validated for both human or rabbit serum. The inter batch precision of quality control samples in human serum for neomycin ranged from 4.46% to 8.99% and for bacitracin from 6.85% to 11.17%. The inter batch accuracy for neomycin ranged from 98.7% to 100.7% and for bacitracin from 99.2% to 103.0%. At lower limit of quantitation (LLOQ) level of 0.2 microg/mL inter batch precision in human serum for neomycin was 12.05% and for bacitracin 11.91%, whereas accuracies were 99.9% for neomycin and 102.7% for bacitracin. Bench top stability in human or rabbit serum was given over three freeze thaw cycles and 4h at room temperature. The method can be considered to be specific and recoveries for sample preparation were high.

  3. Methylene blue test

    Science.gov (United States)

    Methemoglobinemia - methylene blue test ... No special preparation is required for this test. ... which are genetic (problem with your genes). This test is used to tell the difference between methemoglobinemia ...

  4. Successful resuscitation of a patient who developed cardiac arrest from pulsed saline bacitracin lavage during thoracic laminectomy and fusion.

    Science.gov (United States)

    Greenberg, Steven B; Deshur, Mark; Khavkin, Yevgeniy; Karaikovic, Elden; Vender, Jeffery

    2008-06-01

    A patient with a history of T12 burst fracture caused by a fall, and with progressive weakness and sensory loss in the left leg, survived a cardiac arrest after pulsed saline bacitracin lavage irrigation during a posterior spinal fusion.

  5. Facile synthesis of bacitracin-templated palladium nanoparticles with superior electrocatalytic activity

    Science.gov (United States)

    Li, Yanji; Wang, Zi; Li, Xiaoling; Yin, Tian; Bian, Kexin; Gao, Faming; Gao, Dawei

    2017-02-01

    Palladium nanomaterials have attracted great attention on the development of electrocatalysts for fuel cells. Herein, we depicted a novel strategy in the synthesis of palladium nanoparticles with superior electrocatalytic activity. The new approach, based on the self-assembly of bacitracin biotemplate and palladium salt for the preparation of bacitracin-palladium nanoparticles (Bac-PdNPs), was simple, low-cost, and green. The complex, composed by a series of spherical Bac-PdNPs with a diameter of 70 nm, exhibited a chain-liked morphology in TEM and a face-centered cubic crystal structure in X-Ray diffraction and selected area electron diffraction. The palladium nanoparticles were mono-dispersed and stable in aqueous solution as shown in TEM and zeta potential. Most importantly, compared to the commercial palladium on carbon (Pd/C) catalyst (8.02 m2 g-1), the Bac-PdNPs showed a larger electrochemically active surface area (47.57 m2 g-1), which endowed the products an excellent electrocatalytic activity for ethanol oxidation in alkaline medium. The strategy in synthesis of Bac-PdNPs via biotemplate approach might light up new ideas in anode catalysts for direct ethanol fuel cells.

  6. Combined evaluation of three broiler trials testing the effects of roxarsone and zinc bacitracin in the presence of aklomide

    Energy Technology Data Exchange (ETDEWEB)

    Damron, B.L.; Harms, R.H.; Couch, J.R.; Smith, T.W. Jr.; Day, E.J.; Dilworth, B.C.

    1975-01-01

    Broilers were grown to eight weeks of age at three experiment station locations to evaluate the influence of roxarsone and zinc bacitracin in the presence of aklomide. Dietary treatments consisted of a 4 x 4 factorial design in which levels of 0, 25, 50 or 75 ppM of roxarsone were fed with 0, 15, 30 or 60 g./ton of zinc bacitracin. All treatment groups received 0.025% aklomide. Eight-week data indicated that zinc bacitracin alone produced no growth or feed efficiency response at any level of supplementation. Birds receiving roxarsone had significantly higher body weights at eight weeks of age than did birds receiving the control diet. The three levels of roxarsone produced statistically equivalent body weights. A level of 75 ppM roxarsone in the presence of aklomide provided a significant improvement in feed efficiency over that seen for birds receiving either 50 ppM of roxarsone or the unsupplemented control diet. Statistical evaluations indicated that the inclusion of roxarsone and zinc bacitracin in the presence of aklomide did not produce any body weight or feed efficiency interaction. The rate of mortality was not significantly influenced by any of the dietary treatments. 13 references, 4 tables.

  7. Inhibition of resistance plasmid transfer in Escherichia coli by ionophores, chlortetracycline, bacitracin, and ionophore/antimicrobial combinations.

    Science.gov (United States)

    Mathers, Jeremy J; Clark, Steven R; Hausmann, Denny; Tillman, Paul; Benning, Valerie R; Gordon, Shelly K

    2004-01-01

    Medicinal feed additives bacitracin, chlortetracycline (CTC), laidlomycin, lasalocid, and salinomycin inhibited the transfer of multiresistance-conferring plasmid pBR325 (Tet(r) Amp(r) Cp(r), 6.0 kb) into selected gram-negative strains with the use of an in vitro model. High concentrations of ampicillin-sensitive competence-pretreated Escherichia coli HB 101 cells were exposed to 10% (v/v) of 1:10 dimethyl sulfoxide/agent : water containing test mixtures for 0.5 hr prior to plasmid addition and transforming conditions. Transformation was inhibited for all antimicrobials and showed a positive association wich higher concentration. Additional testing of ionophore compounds separately and in combination with bacitracin, chlortetracycline, lincomycin, roxarsone, tylosin, and virginiamycin at representative feed concentrations demonstrated 80.6% to >99.9% inhibition (P < 0.001) of resistance transfer. Bacitracin alone inhibited transformation within the range of 50-500 ppm. No increase in resistance transfer was observed when poultry-derived and reference gram-negative isolates having low or no transformation efficiency were additionally tested. The results suggest that these compounds, at relevant concentrations used in animal feed, may interfere with cell envelope-associated DNA uptake channels or other transformation competence mechanisms. Through these mechanisms, ionophores and cell membrane-interactive feed agents such as CTC and bacitracin may act to inhibit resistance transfer mechanisms within poultry and livestock.

  8. Electrochemical Polymerization of Methylene Green

    Institute of Scientific and Technical Information of China (English)

    ZHU,Hong-Ping; MU,Shao-Lin

    2001-01-01

    The electrochemical polymerization of methylene green has been carried out using cyclic voltammetry. The electrolytic so lution consisted of 4 × 10-3 mol/L methylene green, 0.1 mol/L NaNO3 and 1 × 10-2 mol/L sodium tetraborate with pH 11.0. The temperature for polymerization is controlled at 60℃. The scan potential is set between -0.2 and 1.2 V (vs. Ag/AgCl with saturated KCl solution). There are an anodic peak and a cathodic peak on the cyclic voltammogram of poly(methylene green) at pH≤3.8. Both peak potentials shift towards nega tive potentials with increasing pH value, and their peak cur rents decrease with increasing pH value. Poly(methylene green) has a good electrochemical activity and stability in aqueous solutions with pH ≤ 3.8. The UV-Visible spectrum and FTIR spectrum of poly (methylene green) are different from those of methylene green.

  9. Compatibility and anticoccidial activity of lasalocid in combination with roxarsone and antibiotics against Eimeria mixed infection in chicks.

    Science.gov (United States)

    Schildknecht, E G; Trainor, C; Givens, S V; De Young, W W; Mitrovic, M

    1980-02-01

    Lasalocid at the concentration of .0075% (68 g/ton) with and without roxarsone 45.4 g/ton was fed in combination with the growth promotants bacitracin methylene disalicylate 200 g/ton, bambermycins 2 g/ton, lincomycin 4 g/ton, nosiheptide 2.5 g/ton, zinc bacitracin 200 g/ton g/ton, and virginiamycin 20 g/ton exhibited a high degree of anticoccidial activity against mixed Eimeria infection in chickens in 9 day challenged battery trials. In these short term challenge trials chicks fed lasalocid, and the lasalocid growth promotant combinations, performed significantly better (P roxarsone-antibiotic combinations allowed for numerical increases in gains, improvement in feed conversion, and numerical decreases in lesions (in some cases, statistically significant (P roxarsone was combined with the antibiotics, the combination resulted in numerically improved performance, reduced mortality, and in most instances, statistically significant decreases in lesions (P .05) over the infected, unmedicated control.

  10. Collaborative study of a microbiological screening method (three-plate) for the banned antimicrobial growth promotors tylosin, virginiamycin, spiramycin, zinc bacitracin and avoparcin in animal feed

    NARCIS (Netherlands)

    Pol-Hofstad, I.; Lankveld, van W.D.M.; Tomassen, M.J.H.; Jong, de J.; Egmond, van H.J.

    2008-01-01

    A microbiological screening method (three-plate) for the detection of the antimicrobial growth promoters tylosin, spiramycin, virginiamycin, zinc bacitracin, and avoparcin in animal feed has been developed and validated successfully. A collaborative study involving 18 laboratories receiving 172 samp

  11. The two-component signal transduction system YvcPQ regulates the bacterial resistance to bacitracin in Bacillus thuringiensis.

    Science.gov (United States)

    Zhang, Shumeng; Li, Xinfeng; Wang, Xun; Li, Zhou; He, Jin

    2016-10-01

    YvcPQ is one of the two-component signal transduction systems that respond to specific stimuli and enable cells to adjust multiple cellular functions. It consists of a histidine kinase YvcQ and a response regulator YvcP. In this study, through searching the consensus sequence recognized by YvcP, we found four YvcP-binding motifs in the promoter regions of genes yvcR (BMB171_C4100), BMB171_C4385, kapD (BMB171_C4525) and BMB171_C4835 in Bacillus thuringiensis BMB171 which is a representative of Bacillus cereus group, and confirmed that these genes are regulated by YvcP. We compared the sequence of yvcPQ and its downstream genes in genus Bacillus, and found two different kinds of yvc locus, one was the yvcPQ-RS in B. subtilis species and the other was the yvcPQ-R-S1S2 in B. cereus group. Furthermore, we found that YvcP activates the transcription of yvcS1S2 (downstream of yvcR) to promote bacterial resistance to bacitracin and deletion of either yvcPQ operon or yvcS1S2 operon renders the bacterial cells more sensitive to bacitracin. This study enriched our understanding of both the YvcPQ's function and the mechanism of bacterial resistance to bacitracin.

  12. Identification and characterization of SMU.244 encoding a putative undecaprenyl pyrophosphate phosphatase protein required for cell wall biosynthesis and bacitracin resistance in Streptococcus mutans.

    Science.gov (United States)

    Jalal, Naif; Tian, Xiao-Lin; Dong, Gaofeng; Upham, Jacqueline; Chen, Chao; Parcells, Madison; Li, Yung-Hua

    2015-09-01

    Streptococcus mutans in dental biofilms often faces life-threatening threats such as killing by antimicrobial molecules from competing species or from the host. The ability of S. mutans to cope with such threats is crucial for its survival and persistence in dental biofilms. By screening a transposon mutant library, we identified 11 transposon insertion mutants that were sensitive to bacitracin. Two of these mutants, XTn-01 and XTn-03, had an independent insertion in the same locus, SMU.244, which encoded a homologue of undecaprenyl pyrophosphate phosphatase (UppP). In this study, we describe the genetic and phenotypic characterization of SMU.244 in antibiotic resistance. The results revealed that deletion of SMU.244 results in a mutant (XTΔ244) that is highly sensitive to bacitracin, but confers more resistance to lactococcin G, a class IIb bacteriocin. Introduction of the intact SMU.244 into XTΔ244 in trans completely restores its resistance to bacitracin and the susceptibility to lactococcin G. The XTΔ244 was also defective in forming the WT biofilm, although its growth was not significantly affected. Using recombinant protein technology, we demonstrated that the SMU.244-encoded protein displays enzyme activity to catalyse dephosphorylation of the substrate. The lux transcriptional reporter assays showed that S. mutans maintains a moderate level of expression of SMU.244 in the absence of bacitracin, but bacitracin at sub-MICs can further induce its expression. We concluded that SMU.244 encodes an UppP protein that plays important roles in cell wall biosynthesis and bacitracin resistance in S. mutans. The results described here may further our understanding of the molecular mechanisms by which S. mutans copes with antibiotics such as bacitracin.

  13. Antiviral propierties of 5,5'-dithiobis-2-nitrobenzoic acid and bacitracin against T-tropic human immunodeficiency virus type 1

    Directory of Open Access Journals (Sweden)

    Rodriguez-Padilla Cristina

    2011-03-01

    Full Text Available Abstract Bacitracin and the membrane-impermeant thiol reagent 5,5'-dithiobis-2-nitrobenzoic acid (DTNB are agents known to inhibit protein disulfide isomerase (PDI, a cell-surface protein critical in HIV-1 entry therefore they are fusion inhibitors (FI. Here we investigated the possibility that Bacitracin and or DTNB might have other antiviral activities besides FI. By means of residual activity assays, we found that both compounds showed antiviral activity only to viruses T-tropic HIV-1 strain. Cell-based fusion assays showed inhibition on HeLa-CD4-LTR-β-gal (CD4 and HL2/3 cells treated with Bacitracin, and DTNB with the latest compound we observed fusion inhibition on both cells but strikingly in HL2/3 cells (expressing Env indicating a possible activity on both, the cell membrane and the viral envelope. A time-of-addition experiment showed that both compounds act on HIV entry inhibition but DTNB also acts at late stages of the viral cycle. Lastly, we also found evidence of long-lasting host cell protection in vitro by DTNB, an important pharmacodynamic parameter for a topical microbicide against virus infection, hours after the extracellular drug was removed; this protection was not rendered by Bacitracin. These drugs proved to be leading compounds for further studies against HIV showing antiviral characteristics of interest.

  14. Tylosin and chlorotetracycline decrease the duration of fecal shedding of E. coli O157:H7 by swine.

    Science.gov (United States)

    Cornick, Nancy A

    2010-07-14

    Previously we have shown that experimentally infected swine, fed an antibiotic-free diet, can become colonized and shed Escherichia coli O157:H7 for at least 2 months. However, in epidemiological studies this organism is only rarely recovered from domestic swine and the basis for this discrepancy is not clear. In this report we demonstrate that significantly fewer pigs fed diets containing subtherapeutic levels of either tylosin or chlorotetracycline shed E. coli O157:H7 for longer than 2 weeks compared to those fed an antibiotic-free diet. In contrast to tylosin and chlorotetracycline, the addition of bacitracin methylene disalicylate to the diet did not influence the recovery of E. coli O157:H7. These results suggest that some antibiotics may alter the gastrointestinal tract flora in ways that create a less favorable environment for E. coli O157:H7 in swine.

  15. Response of S. thermophilus LMD-9 to bacitracin: involvement of a BceRS/AB-like module and of the rhamnose-glucose polysaccharide synthesis pathway.

    Science.gov (United States)

    Thevenard, B; Besset, C; Choinard, S; Fourcassié, P; Boyaval, P; Monnet, V; Rul, F

    2014-05-02

    Streptococcus thermophilus is a lactic acid bacterium of major importance to the dairy industry as it is found in numerous cheeses and is one of the two bacterial species involved in the fermentation of yogurt. Bacterial two-component signal transduction systems (TCSs) play important roles in the process of bacterial environmental adaptation. S. thermophilus LMD-9 possesses eight such TCS systems; however, their functions have thus far been only poorly investigated. Here, we focused on two of the TCSs in LMD-9, TCS06 and TCS07, whose encoding genes are located close to each other on the chromosome, and are associated with those of ABC transporters. TCS06 homologs are frequently found in Lactobacillales, but their function has not yet been determined, while TCS07 and its upstream potential ABC transporter are homologous to the BceRS/AB system, which is involved in bacitracin resistance in Bacillus and Streptococcus species. To investigate the function(s) of TCS06 and TCS07, we constructed and characterized deletion mutants and performed transcriptional analysis in the presence and absence of bacitracin. We show here that both TCS06 and TCS07 regulate the genes in their close vicinity, in particular those encoding ABC transporters. We propose that the response of S. thermophilus to bacitracin includes i) a bacitracin export system, regulated by TCS07 and constituting a BceRS/AB-like detoxification module, and ii) the modification of cell-envelope properties via modulation of rhamnose-glucose polysaccharide synthesis, at least partially regulated by TCS06.

  16. Effects of Fructooligosaccharides,compared with Direct-Fed Microbial Bacteria,and Zinc Bacitracin on Cecal Microbial Populations and Performance of Broilers

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An experiment was conducted to determine the effects of dietary fructooligosaccharides(FOS),compared with direct-fed microbial bacteria (DFM),and zinc bacitracin ,on cecal microbial populations and performance of broiler Chickens. One hundred and ninety-two broilers (Avian) were randomly assigned to four groups,with four replicates of 12 birds each. The control group was fed with the basal diet,without any drug additive. FOS,DFM and zine bacitracin was respectively added to the basal diet at the level of 1.5% ,800 mg@kg-1 and 300 mg@ kg-1 to form the experimental diets. Body weight ,feed intake and feed efficiency were measured weekly. The feeding trial started at 1 d and ended at 21 d. At day 14 and day 21 ,four broilers per group were killed and cecum waa taken to determined microflors and pH. The results showed that dietary FOS increased bifidobactrial concentration by 1. 75-fold( P <0. 05) at 14 d of age and 1.45-fold( P <0. 05) at 21 d of age compared with control. FOS had no effect on concnetrations of E. coli and pH. There were no dietary effects of FOS,DFM,and zinc bacitracin on weight gain,feed intake,feed conversion( P >0. 05).

  17. Collaborative study of a microbiological screening method (three-plate) for the banned antimicrobial growth promotors tylosin, virginiamycin, spiramycin, zinc bacitracin and avoparcin in animal feed.

    Science.gov (United States)

    Pol-Hofstad, I; Driessen-Van Lankveld, W; Tomassen, M; De Jong, J; Van Egmond, H

    2008-12-01

    A microbiological screening method (three-plate) for the detection of the antimicrobial growth promoters tylosin, spiramycin, virginiamycin, zinc bacitracin, and avoparcin in animal feed has been developed and validated successfully. A collaborative study involving 18 laboratories receiving 172 samples was carried out to verify the performance characteristics. The detection level for tylosin/virginiamycin/spiramycin, expressed in microbiological activity, was 1 mg kg(-1) (false-positives, 2%; false-negatives, 3, 0, and 6%, respectively). Avoparcin could be detected at 1 mg kg(-1) in feed in general (false-positives, 2%; false-negatives, 0%). However, in calf feed the sensitivity was lower. The percentages of false-negatives were found to be 12%, 7%, and 0% at 1, 3, and 5 mg kg(-1), respectively (false-positives, 4%). The limit of detection for zinc bacitracin was 3-5 mg kg(-1) (false-positives, 5-10%; false-negatives, 77% at 1 mg kg(-1), 45% at 2 mg kg(-1), 12% at 3 mg kg(-1), and 4% at 5 mg kg(-1)). The method allowed for a distinction to be made between the groups of antibiotics: avoparcin/zinc bacitracin versus tylosin/virginiamycin/spiramycin. This definitely gives added value to the method in the framework of a follow-up of positive screening results by post-screening and confirmatory analysis.

  18. Methylene Blue Causing Serotonin Syndrome Following Cystocele Repair.

    Science.gov (United States)

    Kapadia, Kailash; Cheung, Felix; Lee, Wai; Thalappillil, Richard; Florence, F Barry; Kim, Jason

    2016-11-01

    Methylene blue is an intravenously administered agent that may potentiate serotonin syndrome. The usage of methylene blue to evaluate ureters for injuries and patency during urological surgeries is recognized as common practice. However, there is no mention of serotonin syndrome caused by methylene blue in urological literature or for urological surgery. We report the first urological case in order to raise awareness of the risk for serotonin toxicity with utilizing methylene blue.

  19. Methylene Blue Causing Serotonin Syndrome Following Cystocele Repair

    Directory of Open Access Journals (Sweden)

    Kailash Kapadia

    2016-11-01

    Full Text Available Methylene blue is an intravenously administered agent that may potentiate serotonin syndrome. The usage of methylene blue to evaluate ureters for injuries and patency during urological surgeries is recognized as common practice. However, there is no mention of serotonin syndrome caused by methylene blue in urological literature or for urological surgery. We report the first urological case in order to raise awareness of the risk for serotonin toxicity with utilizing methylene blue.

  20. Compound list: methylene dianiline [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available methylene dianiline DAPM 00155 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/in_vitro/meth...es/LATEST/Rat/in_vivo/Liver/Single/methylene_dianiline.Rat.in_vivo.Liver.Single.zip ftp://ftp.biosciencedbc....jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/methylene_dianiline.Rat.in_vivo.Liver.Repeat.zip ...

  1. Methylene blue promotes quiescence of rat neural progenitor cells.

    Science.gov (United States)

    Xie, Luokun; Choudhury, Gourav R; Wang, Jixian; Park, Yong; Liu, Ran; Yuan, Fang; Zhang, Chun-Li; Yorio, Thomas; Jin, Kunlin; Yang, Shao-Hua

    2014-01-01

    Neural stem cell-based treatment holds a new therapeutic opportunity for neurodegenerative disorders. Here, we investigated the effect of methylene blue on proliferation and differentiation of rat neural progenitor cells (NPCs) both in vitro and in vivo. We found that methylene blue inhibited proliferation and promoted quiescence of NPCs in vitro without affecting committed neuronal differentiation. Consistently, intracerebroventricular infusion of methylene blue significantly inhibited NPC proliferation at the subventricular zone (SVZ). Methylene blue inhibited mTOR signaling along with down-regulation of cyclins in NPCs in vitro and in vivo. In summary, our study indicates that methylene blue may delay NPC senescence through enhancing NPCs quiescence.

  2. Application and research progress of bacitracin production in animal feed%杆菌肽产品在动物饲料中的应用研究进展

    Institute of Scientific and Technical Information of China (English)

    周岩民; 王龙昌

    2012-01-01

    Bacitracin is a kind of polypeptide antibiotics. It can promote the animal growth, improve the feed conversion ratio, prevent and cure a variety of animal intestinal diseases. Furthermore, it has many excellent properties, such as no residue, no withdrawal period, no drug resistance, no toxic side effect, and safety to use. Bacitracin has been widely used in animal production and feed industry. The brief introduction on the physicochemical properties and characteristics of bacitracin, application and research progress of bacitracin productions in animal feed was reviewed. Moreover, the market and application prospect of bacitracin in feed were discussed.%杆菌肽是一种多肽类抗生素,具有促进动物生长、提高饲料转化率、预防和治疗多种动物肠道疾病的作用,同时具有无残留、无休药期、不产生耐药性、无毒副作用、安全性好等特性,在动物养殖和饲料生产中已有广泛应用.文中简介了杆菌肽的理化性质及其特点,综述了杆菌肽产品在动物饲料中的应用研究进展,并分析和展望了杆菌肽产品的市场应用前景.

  3. Intravital staining with methylene blue in tympanoplasty.

    Science.gov (United States)

    Vaiman, Michael; Sarfaty, Shlomo; Gavriel, Haim; Kraus, Moshe; Kaplan, Daniel; Puterman, Max

    2010-09-01

    Objective of the study is to investigate usefulness of the methylene blue staining for the operation of tympanoplasty in surgical training process with randomized, controlled trial. Two hospitals were involved: Department of Otolaryngology, Assaf Harofeh Medical Center, and Department of Otolaryngology Head and Neck Surgery, Soroka University Medical Center. Tympanoplasty with graft placement was performed by young surgeons on 30 patients (30 ears) with anterior perforations using intraoperative staining of tympanoplasty grafts with methylene blue (Group 1). The same number of patients/ears was operated by the young surgeons without intraoperative staining (Group 2). 76 patients operated without staining by experienced surgeons served as a control group. Results showed tympanic membrane healing (graft take) in 30 (100%) cases in Group 1 and in 26 (86.66%) cases in Group 2. The pure-tone audiogram testing revealed significant improvement of hearing in all successful cases (p < 0.05). No side immediate or postponed effects were detected. We conclude that intravital staining with methylene blue in tympanoplasty simplifies the operation and could assist in better visualization and proper placement of the graft. This technique could be most useful in a training process for resident surgeons.

  4. Spectrometric study of α-methylene aromatic araminenone and aminoketone

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Thirteen α-methylene aromatic araminenone and four α-methylene aromatic aminoketones were prepared by modified Mannich reaction. On the basis of isotopic labeling, a plausible way of cleavage was proposed for the formation of the M+- 17 fragment peak in the MS of the α-methylene aromatic araminenone and aminoketones. The characteristic chemical shift of the olefinic protons in 1H NMR is also discussed.

  5. Methylene Blue Inhibits Caspases by Oxidation of the Catalytic Cysteine.

    Science.gov (United States)

    Pakavathkumar, Prateep; Sharma, Gyanesh; Kaushal, Vikas; Foveau, Bénédicte; LeBlanc, Andrea C

    2015-09-24

    Methylene blue, currently in phase 3 clinical trials against Alzheimer Disease, disaggregates the Tau protein of neurofibrillary tangles by oxidizing specific cysteine residues. Here, we investigated if methylene blue can inhibit caspases via the oxidation of their active site cysteine. Methylene blue, and derivatives, azure A and azure B competitively inhibited recombinant Caspase-6 (Casp6), and inhibited Casp6 activity in transfected human colon carcinoma cells and in serum-deprived primary human neuron cultures. Methylene blue also inhibited recombinant Casp1 and Casp3. Furthermore, methylene blue inhibited Casp3 activity in an acute mouse model of liver toxicity. Mass spectrometry confirmed methylene blue and azure B oxidation of the catalytic Cys163 cysteine of Casp6. Together, these results show a novel inhibitory mechanism of caspases via sulfenation of the active site cysteine. These results indicate that methylene blue or its derivatives could (1) have an additional effect against Alzheimer Disease by inhibiting brain caspase activity, (2) be used as a drug to prevent caspase activation in other conditions, and (3) predispose chronically treated individuals to cancer via the inhibition of caspases.

  6. Preparation of Methylene Blue-Silica Composite Microcapsules

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Hideo. [Nihon Millipore Corp., Yamagata (Japan); Takahashi, Koji. [Yamagata University, Yamagata (Japan). Department of Materials Science and Engineering

    1999-06-01

    Silica microcapsules comprising methylene blue (MB-SiO{sub 2}) of mean diameter 4.0 {mu}m were prepared by solgel and water-in-oil emulsion techniques where water pools are use as microreactors in which methylene blue is dissolved at a high water to surfactant molar ratio. It is confirmed that the cationic methylene blue is incorporated in the silica microcapsule wall during hydrolysis and condensation of tetraethoxysilane. Fixation of methylene blue in the silica wall is examined by passing water or acetic acid aq. soln. (pH 2-4) through a cartridge in which MB-SiO{sub 2} is packed and then measuring the fractions using UV-VIS analysis. The elution behavior is affected drastically by the pH value of the eluent. Methylene blue tends to stay in the wall when the pH value of eluent is above the isoelectric point (IEP) of the silica microcapsules. However, release of methylene blue cation occurs when it is below the IEP. These results reveal that coulomb interaction has an important role to fix methylene blue in the silica microcapsule. (author)

  7. Adsorption Kinetics of Methylene Blue from Aqueous Solutions onto Palygorskite

    Institute of Scientific and Technical Information of China (English)

    PENG Shuchuan; WANG Shisheng; CHEN Tianhu; JIANG Shaotong; HUANG Chuanhui

    2006-01-01

    The adsorption kinetics of methylene blue from aqueous solutions on purified palygorskite was investigated. The kinetics data related to the adsorption of methylene blue from aqueous solutions are in good agreement with the pseudo-second order equation in ranges of initial concentration of 120-210 mg/L, oscillation speed of 100-200 r/min and temperature of 298-328K. The experimental results show that methylene blue is only adsorbed onto the external surface of purified palygorskite,and the apparent adsorption activation energy is 13.92 k J/mol. The relatively low apparent adsorption activation energy suggests that the adsorption of methylene blue involves in not only a chemical, but also a physical adsorption process, and it is controlled by the combination of chemical adsorption and liquid-film diffusion.

  8. Determinación in vitro del efecto antibacteriano de un extracto obtenido de quebracho colorado, Schinopsis lorentzii In vitro determination of the antibacterial effect of a quebracho colorado Schinopsis lorentzii extract

    Directory of Open Access Journals (Sweden)

    F Prosdócimo

    2010-12-01

    Full Text Available Últimamente se incrementó la búsqueda de promotores de crecimiento naturales en reemplazo de antibióticos, restringidos por normativas internacionales. Se determinó la actividad inhibitoria in vitro de un extracto de quebracho colorado (Schinopsis lorentzii compuesto por polifenoles con catequinas sobre algunas bacterias patógenas comparándolo con Bacitracina Metileno Disalicilato al 11 %. Del primero se utilizaron dosis de 500 ppm hasta 0,05 ppm en diluciones crecientes. La Bacitracina fue utilizada de 330 ppm hasta 0,03 ppm. Se aplicó el método de difusión en agar modificado por Vignolo et al sobre Salmonella Gallinarum biotipo gallinarum, Escherichia coli, Clostridium perfrigens y Staphylococcus aureus. Tanto el Extracto como la Bacitracina actuaron contra bacterias Gram positivas como Gram negativas en diversas concentraciones. Estos datos permiten suponer que los polifenoles con catequinas pueden transformarse en una herramienta para sustituir los antibióticos promotores de crecimiento, proveyendo un producto de origen natural inocuo para la salud humana.Lately, the search for natural growth promoters to replace antibiotics, restricted by internationals regulations, has increased. The in vitro inhibitory activity of a red quebracho extract (Schinopsisi lorentzii composed of polyphenols over some pathogenic bacteria was determined, comparing it to Bacitracin Methylene Disalicylate at 11 %. Of the first one, doses of 500 ppm up to 0,05 ppm in increasing dilutions were tested. The Bacitracin was used of 330 ppm up to 0,03 ppm. The method of diffusion in agar, modified by Vignolo et al, was applied on Salmonella gallinarum, Escherichi coli, Clostridium perfrigens and Staphylococcus aureus. The extract, as well as the Bacitracin, acted against Gram negative and Gram positive bacteria in various concentrations. These data lead us to suppose that polyphenols may become a tool to substitute antibiotic growth promoters, providing a

  9. Alteration of gut microbiota by vancomycin and bacitracin improves insulin resistance via glucagon-like peptide 1 in diet-induced obesity.

    Science.gov (United States)

    Hwang, Injae; Park, Yoon Jeong; Kim, Yeon-Ran; Kim, Yo Na; Ka, Sojeong; Lee, Ho Young; Seong, Je Kyung; Seok, Yeong-Jae; Kim, Jae Bum

    2015-06-01

    Firmicutes and Bacteroidetes, 2 major phyla of gut microbiota, are involved in lipid and bile acid metabolism to maintain systemic energy homeostasis in host. Recently, accumulating evidence has suggested that dietary changes promptly induce the alteration of abundance of both Firmicutes and Bacteroidetes in obesity and its related metabolic diseases. Nevertheless, the metabolic roles of Firmicutes and Bacteroidetes on such disease states remain unclear. The aim of this study was to determine the effects of antibiotic-induced depletion of Firmicutes and Bacteroidetes on dysregulation of energy homeostasis in obesity. Treatment of C57BL/6J mice with the antibiotics (vancomycin [V] and bacitracin [B]), in the drinking water, before diet-induced obesity (DIO) greatly decreased both Firmicutes and Bacteroidetes in the gut as revealed by pyrosequencing of the microbial 16S rRNA gene. Concomitantly, systemic glucose intolerance, hyperinsulinemia, and insulin resistance in DIO were ameliorated via augmentation of GLP-1 secretion (active form; 2.03-fold, total form; 5.09-fold) independently of obesity as compared with untreated DIO controls. Furthermore, there were increases in metabolically beneficial metabolites derived from the gut. Together, our data suggest that Firmicutes and Bacteroidetes potentially mediate insulin resistance through modulation of GLP-1 secretion in obesity.

  10. Synthesis and biological study of novel methylene-bis-benzofuranyl-

    Directory of Open Access Journals (Sweden)

    Sanjeeva R. Cherkupally

    2008-12-01

    Full Text Available A series of novel methylene-bis-[1,5]-benzothiazepines 4 and methylene-bis-benzofuranyl-[1,5]-benzothiazepines 5 were prepared by the reaction of methylene-bis-chalcones 3 with 2-aminothiophenolfollowed by the condensation with -bromoacetophenone. The structures of the synthesized compounds wereconfirmed by their IR, 1H, 13C NMR and Mass spectral analyses. All the synthesized compounds were tested fortheir antimicrobial activity against Gram-positive, Gram-negative bacteria and fungi. Among the synthesizedcompounds, the compounds 4f, 4g, 5f and 5g were found to be the most active against Bacillus subtilis, Bacillussphaericus, Staphylococcus aureus, Klebsiella aerogenes and Chromobacterium violaceum. Similarly thesecompounds showed potent antifungal effect against Candida albicans, Aspergillus fumigatus, Trichophytonrubrum, and Trichophyton mentagrophytes. It is interesting to note that the compounds with heterocyclic ringsubstituents at the 4th position of benzothiazepine system displayed notable antibacterial activity, almost equalto that of streptomycin and penicillin.

  11. Nitroreductase-triggered activation of a novel caged fluorescent probe obtained from methylene blue.

    Science.gov (United States)

    Bae, Jungeun; McNamara, Louis E; Nael, Manal A; Mahdi, Fakhri; Doerksen, Robert J; Bidwell, Gene L; Hammer, Nathan I; Jo, Seongbong

    2015-08-18

    A near-infrared fluorescent probe based on methylene blue (p-NBMB) was developed for the detection of nitroreductase. Conjugating methylene blue with a p-nitrobenzyl moiety enables it to be activated by nitroreductase-catalyzed 1,6-elimination, resulting in the release of an active methylene blue fluorophore.

  12. 21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Methylene blue-containing drugs for use in animals... Decisions § 500.27 Methylene blue-containing drugs for use in animals. (a) New information requires a re- evaluation of the status of drugs containing methylene blue (tetramethylthionine chloride) for oral use...

  13. Methylene chloride: two-generation inhalation reproductive study in rats

    Energy Technology Data Exchange (ETDEWEB)

    Nitschke, K.D.; Eisenbrandt, D.L.; Lomax, L.G.; Rao, K.S.

    1988-07-01

    Reproductive parameters in Fischer 344 rats were evaluated following inhalation of methylene chloride (MeCl/sub 2/) for two successive generations. Thirty male and female rats were exposed to 0, 100, 500, or 1500 ppm MeCl/sub 2/ for 6 hr/day, 5 days/week for 14 weeks and then mated to produce f1 litters. After weaning, 30 randomly selected f1 pups/sex/group were exposed to MeCl/sub 2/ for 17 weeks and subsequently mated to produce f2 litters. Reproductive parameters examined included fertility, litter size and neonatal growth, and survival. All adults and selected weanlings were examined for grossly visible lesions. Tissues from selected weanlings were examined histopathologically. No adverse effects on reproductive parameters, neonatal survival, or neonatal growth were noted in animals exposed to methylene chloride in either the f0 or f1 generations. Similarly, there were no treatment-related gross pathologic observations in f0 or f1 adults or f1 and f2 weanlings. Histopathologic examination of tissues from f1 and f2 weanlings did not reveal any lesions attributed to methylene chloride. Thus, exposure of rats to concentrations as high as 1500 ppm methylene chloride, which has been shown in a 2-year study to produce treatment-related effects, did not affect any reproductive parameters.

  14. Extinction Memory Improvement by the Metabolic Enhancer Methylene Blue

    Science.gov (United States)

    Gonzalez-Lima, F.; Bruchey, Aleksandra K.

    2004-01-01

    We investigated whether postextinction administration of methylene blue (MB) could enhance retention of an extinguished conditioned response. MB is a redox compound that at low doses elevates cytochrome oxidase activity, thereby improving brain energy production. Saline or MB (4 mg/kg intraperitoneally) were administered to rats for 5 d following…

  15. Methylene Blue-Ascorbic Acid: An Undergraduate Experiment in Kinetics.

    Science.gov (United States)

    Snehalatha, K. C.; And Others

    1997-01-01

    Describes a laboratory exercise involving methylene blue and L-ascorbic acid in a simple clock reaction technique to illustrate the basic concepts of chemical kinetics. If stock solutions are supplied and each type of experiment takes no more than half an hour, the entire investigation can be completed in three practical sessions of three hours…

  16. Spatial interaction of methylene blue stained soil pores

    NARCIS (Netherlands)

    Stein, A.; Lieshout, van M.N.M.; Booltink, H.W.G.

    2001-01-01

    In this paper, we compare different types of patterns that emerge when applying methylene blue dye as a tracer on soils to detect preferential flow paths as a result of large cracks. Patterns on channels, vughs and cracks are analyzed with the J-function and with indicator variograms. By means of a

  17. Antibiotic resistance in Escherichia coll and Enterococcus spp. isolates from commercial broiler chickens receiving growth-promoting doses of bacitracin or virginiamycin.

    Science.gov (United States)

    Thibodeau, Alexandre; Quessy, Sylvain; Guévremont, Evelyne; Houde, Alain; Topp, Edward; Diarra, Moussa Sory; Letellier, Ann

    2008-01-01

    Antibacterial agents such as zinc bacitracin (ZB) and virginiamycin (VG) are used as growth promoting agents (GP) in broiler chicken production. The objective of this study was to evaluate the effect of the use of ZB and VG on the emergence of antibacterial resistance in a commercial broiler chicken farm. Three trials were conducted using 3 different diets: one without antibacterial agents, one containing VG, and one with ZB. Escherichia coli and Enterococcus spp. strains were isolated and tested for their susceptibility to various antibacterial agents. The occurrence of the resistance genes vatD, ermB, and bcrR in Enterococcus spp. isolates was determined by polymerase chain reaction (PCR). Comparative quantification of vatD and bcrR genes in total deoxyribonucleic acid (DNA) extracts from litter was done by SYBR Green Real-Time PCR (QPCR). Escherichia coli and Enterococcus spp. isolates from diet groups had different levels of resistance to various antibacterial agents over time. These GPs did not select for specific antibacterial agent resistance (AAR) in Enterococcus spp. The use of GPs seemed to lower the percentage of E. coli isolates resistant to some antibacterial agents. The presence of the bcrR gene could not explain all resistant phenotypes to ZB. Genes other than vatD and ermB might be involved in the resistance to VG in Enterococcus spp. Use of GPs was not associated with presence of the bcrR gene in DNA extracts from litter, but use of VG was associated with vatD presence.

  18. An introduction to photocatalysis through methylene blue photodegradation

    Science.gov (United States)

    Petit, Matthieu; Michez, Lisa; Raimundo, Jean-Manuel; Malinowski, Tuhiti; Dumas, Philippe

    2016-11-01

    We described a simple experimental set-up for lab work on the photocatalytic degradation of methylene blue by TiO2 nanoparticles. The photocatalysis process can be used for many applications. Treatments for diluted wastewater industries, air purifying in underground car parks, and preventing fouling on glass surfaces, are some of the potential applications of this phenomenon. The described experiment is easy to perform and the interpretation can be easily adapted to different levels of students, from high school students demonstrating their interest in sustainable development, to students obtaining a Masters in science departments who want to propose a full explanation for all phenomena of the photocatalytic process. Starting with a description of the experimental set-up, we analysed the photocatalyst nanoparticles and applied the Langmuir-Hinshelwood model to our experimental data. Finally we briefly discussed the respective energetic levels of the photocatalyst semiconductor and methylene blue.

  19. Methylene blue adsorption on graphene oxide/calcium alginate composites.

    Science.gov (United States)

    Li, Yanhui; Du, Qiuju; Liu, Tonghao; Sun, Jiankun; Wang, Yonghao; Wu, Shaoling; Wang, Zonghua; Xia, Yanzhi; Xia, Linhua

    2013-06-05

    Graphene oxide has been used as an adsorbent in wastewater treatment. However, the dispersibility in aqueous solution and the biotoxicity to human cells of graphene oxide limits its practical application in environmental protection. In this research, a novel environmental friendly adsorbent, calcium alginate immobilized graphene oxide composites was prepared. The effects of pH, contact time, temperature and dosage on the adsorption properties of methylene blue onto calcium alginate immobilized graphene oxide composites were investigated. The equilibrium adsorption data were described by the Langmuir and Freundlich isotherms. The maximum adsorption capacity obtained from Langmuir isotherm equation was 181.81 mg/g. The pseudo-first order, pseudo-second order, and intraparticle diffusion equation were used to evaluate the kinetic data. Thermodynamic analysis of equilibriums indicated that the adsorption reaction of methylene blue onto calcium alginate immobilized graphene oxide composites was exothermic and spontaneous in nature.

  20. An introduction to photocatalysis through methylene blue photodegradation

    OpenAIRE

    Petit, Matthieu; Michez, Lisa; Raimundo, Jean-Manuel; Malinowski, Tuhiti; Dumas, Philippe

    2016-01-01

    International audience; We described a simple experimental setup for a lab work on the photocatalytic degradation of methylene blue by T iO 2 nanoparticles. The photocatalysis process can be used for many applications. Treatments for diluted wastewaters industries, air purifying in underground car parks, preventing fouling on glass surfaces, these are some of the things this phenomenon has the ability to do. The described experiment is easy to perform and the interpretation can be easily adap...

  1. Methylene blue treatment for resistant shock following renal transplantation.

    Science.gov (United States)

    Hershman, Eli; Hadash, Amir; Attias, Ori; Ben-Ari, Josef

    2015-11-01

    We report a case of a 19-year-old female with a history of hyperoxaluria type 1 and renal failure. The patient presented for a second renal transplantation 17 years after her first combined liver and kidney transplantation. Postoperative shock was highly resistant to fluids and required massive pharmacologic hemodynamic support. Vasoplegic shock was the presumed diagnosis, and methylene blue was utilized as a rescue therapy, with a rapid hemodynamic response and no apparent side effects.

  2. Analysis of rhamnolipid biosurfactants by methylene blue complexation.

    Science.gov (United States)

    Pinzon, Neissa M; Ju, Lu-Kwang

    2009-04-01

    Rhamnolipids, produced by Pseudomonas aeruginosa, represent an important group of biosurfactants having various industrial, environmental, and medical applications. Current methods for rhamnolipid quantification involve the use of strong hazardous acids/chemicals, indirect measurement of the concentration of sugar moiety, or require the availability of expensive equipment (HPLC-MS). A safer, easier method that measures the whole rhamnolipid molecules would significantly enhance strain selection, metabolic engineering, and process development for economical rhamnolipid production. A semi-quantitative method was reported earlier to differentiate between the rhamnolipid-producing and non-producing strains using agar plates containing methylene blue and cetyl trimethylammonium bromide (CTAB). In this study, a rapid and simple method for rhamnolipid analysis was developed by systematically investigating the complexation of rhamnolipids and methylene blue, with and without the presence of CTAB. The method relies on measuring the absorbance (at 638 nm) of the rhamnolipid-methylene blue complex that partitions into the chloroform phase. With P. aeruginosa fermentation samples, the applicability of this method was verified by comparison of the analysis results with those obtained from the commonly used anthrone reaction technique.

  3. Enhanced Photocatalytic Performance of NiO-Decorated ZnO Nanowhiskers for Methylene Blue Degradation

    OpenAIRE

    I. Abdul Rahman; Ayob, M. T. M.; Radiman, S.

    2014-01-01

    ZnO nanowhiskers were used for photodecomposition of methylene blue in aqueous solution under UV irradiation. The rate of methylene blue degradation increased linearly with time of UV irradiation. 54% of degradation rate was observed when the ZnO nanowhiskers were used as photocatalysts for methylene blue degradation for 80 min under UV irradiation. The decoration of p-type NiO nanoparticles on n-type ZnO nanowhiskers significantly enhanced photocatalytic activity and reached 72% degradation ...

  4. Methylene blue for distributive shock: a potential new use of an old antidote.

    Science.gov (United States)

    Jang, David H; Nelson, Lewis S; Hoffman, Robert S

    2013-09-01

    Methylene blue is used primarily in the treatment of patients with methemoglobinemia. Most recently, methylene blue has been used as a treatment for refractory distributive shock from a variety of causes such as sepsis and anaphylaxis. Many studies suggest that the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway plays a significant role in the pathophysiology of distributive shock. There are some experimental and clinical experiences with the use of methylene blue as a selective inhibitor of the NO-cGMP pathway. Methylene blue may play a role in the treatment of distributive shock when standard treatment fails.

  5. Organic trace mineral supplementation enhances local and systemic innate immune responses and modulates oxidative stress in broiler chickens.

    Science.gov (United States)

    Echeverry, H; Yitbarek, A; Munyaka, P; Alizadeh, M; Cleaver, A; Camelo-Jaimes, G; Wang, P; O, K; Rodriguez-Lecompte, J C

    2016-03-01

    The effect of organic trace mineral supplementation on performance, intestinal morphology, immune organ weights (bursa of Fabricius and spleen), expression of innate immune response related genes, blood heterophils/lymphocytes ratio, chemical metabolic panel, natural antibodies (IgG), and oxidative stress of broiler chickens was studied. A total of 1,080 day-old male broilers were assigned to 1 of 3 dietary treatments, which included basal diet with Monensin (control), control diet supplemented with bacitracin methylene disalicylate (BMD), and BMD diet supplemented with organic trace minerals (OTM). No difference in feed conversion ratio was observed among treatments; ileum histomorphological analysis showed a lower crypt depth, higher villi height/crypt depth ratio, and lower villi width in the OTM treatment compared to control. Furthermore, OTM treatment resulted in higher uric acid and lower plasma malondehaldehyde (MDA), indicating lower oxidative stress. Gene expression analysis showed that OTM treatment resulted in up-regulations of TLR2 bin the ileum, and TLR2b, TLR4, and IL-12p35 in the bursa of Fabricius, and down-regulation of TLR2b and TLR4 in the cecal tonsils. In the spleen, OTM treatment resulted in up-regulation of IL-10. In conclusion, OTM supplementation to broiler diets may have beneficial effects on intestinal development, immune system status, and survival by improving ileum histomorphological parameters, modulation of Toll-like receptors and anti-inflammatory cytokines, and decreasing level of MDA, which in conjunction could enhance health status.

  6. Intestinal bacterial community and growth performance of chickens fed diets containing antibiotics.

    Science.gov (United States)

    Pedroso, A A; Menten, J F M; Lambais, M R; Racanicci, A M C; Longo, F A; Sorbara, J O B

    2006-04-01

    This study was conducted to relate the performance of broiler chickens fed diets containing growth-promoting antibiotics to changes in the intestinal microbiota. The technique of denaturing gradient gel electrophoresis (DGGE) of amplicons of the region V3 of 16S rDNA was used to characterize the microbiota. Two experiments were conducted, one with broilers raised in battery cages and the other with broilers raised in floor pens. Antibiotics improved the performance of the chickens raised in floor pens only. Avilamycin, bacitracin methylene disalicylate, and enramycin induced changes in the composition of the intestinal bacterial community of the birds in both experiments. The number of bacterial genotypes found in the intestinal tract of chickens was not reduced by the antibiotics supplemented in either environment. However, the changes in the composition of the intestinal bacterial community induced by antibiotics may be related to improvement in growth performance. This was indicated by the suppression of 6 amplicons and the presence of 4 amplicons exclusive to the treatment that had the best performance in the floor pen experiment.

  7. Effect of supplementation of diets with BMD and Virginiamycin on the growth performance, carcass characteristics and bacterial population in broiler chickens

    Directory of Open Access Journals (Sweden)

    Manoj Singh

    2008-10-01

    Full Text Available Broiler chicks of a commercial strain were fed diets containing Bacitracin Methylene Disalicylate @150 g and 200 g/MT and Virginiamycin 500g/MT feed upto 6 weeks of age to evaluate their effects on growth, feed efficiency, carcass characteristics and bacterial population (Salmonella and E. coli. Both BMD and virginiamycin significantly increased (P<0.01 the body weight gains as compare to the control and also improve the feed conversion ratio. The carcass characteristics showed the highest edible weight was recorded in treatment IV where virginiamycin @ 500g/MT feed was incorporated (76.86%, followed by treatment III (71.92%, treatment II (71.41% and the lowest (70.68 in control (T-I. The sample of excreta collected during II, IV and VI week of experiment did not show any incidences of Salmonella in any treatment groups, however, the excreta of six week in all the treatment groups showed the incidences of E. coli. [Veterinary World 2008; 1(5.000: 141-143

  8. Assessment of yeast cell wall as replacements for antibiotic growth promoters in broiler diets: effects on performance, intestinal histo-morphology and humoral immune responses.

    Science.gov (United States)

    Ghosh, T K; Haldar, S; Bedford, M R; Muthusami, N; Samanta, I

    2012-04-01

    The study compared the effects of an antibiotic growth promoter (AGP), yeast (Saccharomyces cerevisiae) and yeast cell wall (YCW) on performance, microbiology and histo-morphology of the small intestine and humoral immune responses in Ross 308 broilers. The treatments (eight replicates/treatment, n = 12/replicate) were negative control (NC, without AGP), positive control (PC, supplemented with bacitracin methylene disalicylate, 400 mg/kg), Y and YCW (supplemented with yeast and YCW, respectively, 1000 mg/kg). Live weight at 42 days improved (p = 0.086) in the PC, Y and YCW groups. Feed conversion ratio was better (p = 0.039) in the YCW group compared with the other groups. Antibiotic growth promoter in the PC group shortened the villi in duodenum (p = 0.044). Mucosal Escherichia coli number was higher in the PC group (p Yeast cell wall -treated birds exhibited better (p yeast and the yeast cell wall may have effects identical to BMD on performance of broilers and thus may constitute an effective replacement strategy in the dietary regimens for broiler chickens.

  9. Magnetic graphene sponge for the removal of methylene blue

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Baowei; Zhang, Xiaoliang; Xie, Jingru; Wu, Ruihan; Liu, Xiaoyang; Li, Hongliang; Chen, Fang; Yang, Hua; Ming, Zhu; Yang, Sheng-Tao, E-mail: yangst@pku.edu.cn

    2015-10-01

    Graphical abstract: - Highlights: • Magnetic graphene sponge is prepared for dye removal in aqueous solution. • Magnetic graphene sponge has an adsorption capacity of 526 mg/g for methylene blue. • Adsorption behaviors of methylene blue on magnetic graphene sponge are investigated. • Magnetic graphene sponge could be partially regenerated by washing with acidic ethanol. - Abstract: Magnetic carbon nanomaterials have been widely adopted as adsorbents in water treatment, but the low adsorption capacities largely limit their practical applications. In this study, magnetic graphene sponge (Fe{sub 3}O{sub 4}-GS) was prepared by lyophilization for the adsorption of dye pollutant. The incorporation of Fe{sub 3}O{sub 4} enabled the magnetic separation of Fe{sub 3}O{sub 4}-GS after the adsorption of methylene blue (MB). The adsorption capacity of Fe{sub 3}O{sub 4}-GS for MB was 526 mg/g, much higher than those of the magnetic carbon nanoadsorbents in the literature. The adsorption kinetics of MB on Fe{sub 3}O{sub 4}-GS was moderately fast, which could be analyzed by the pseudo-second-order model and intraparticle diffusion model. The thermodynamics study revealed that the adsorption was driven by the increased randomness on the interface. The pH and ionic strength had meaningful influences on the adsorption capacity of Fe{sub 3}O{sub 4}-GS. The facile regeneration of Fe{sub 3}O{sub 4}-GS would definitely reduce its operating cost. The implications to the environmental applications of magnetic carbon nanoadsorbents are discussed.

  10. Neomycin, Polymyxin, and Bacitracin Ophthalmic

    Science.gov (United States)

    ... hands thoroughly with soap and water. Use a mirror or have someone else apply the ointment. Avoid ... symptoms, call your doctor immediately: eye pain irritation, burning, itching, swelling, or redness of the eye or ...

  11. ADSORPTION OF METHYLENE BLUE FROM AQUEOUS SOLUTION ON ATTAPULGITE

    Institute of Scientific and Technical Information of China (English)

    WANG Deping; LV Pengfei; YAN Yongsheng; LIU Hui; WANG Guanjun

    2007-01-01

    Batch adsorption experiments were carried out for the removal of methylene blue (MB) from aqueous solution using attapulgite as adsorbent. The effects of various parameters such as temperature, contact time, the pH value, and attapulgite dosage on the adsorption performance were investigated. The standard curve and regression equation were established by spectrophotometry. The adsorption experimental results showed that the adsorption equilibrium data were well in accord with Langmuir adsorptive model. The optimal result was acquired under the experimental condition of attapulgite dosage 0.18g, MB concentration 50.0mg/L, pH 10, and adsorption time 20min at room temperature.

  12. 21 CFR 558.515 - Robenidine hydrochloride.

    Science.gov (United States)

    2010-04-01

    ... to laying hens. Withdraw 5 days before slaughter. 046573 Bacitracin (as bacitracin methylene... prevention level (50 g/ton). Do not feed to laying hens. Withdraw 5 days before slaughter. 046573 Bacitracin... continuously as the sole ration. Do not feed to laying hens. Withdraw 5 days before slaughter....

  13. Nuclear overhauser spectroscopy of chiral CHD methylene groups

    Energy Technology Data Exchange (ETDEWEB)

    Augustyniak, Rafal [Ecole Normale Supérieure – PSL Research University, Département de chimie (France); Stanek, Jan [University of Warsaw, Faculty of Chemistry (Poland); Colaux, Henri; Bodenhausen, Geoffrey [Ecole Normale Supérieure – PSL Research University, Département de chimie (France); Koźmiński, Wiktor [University of Warsaw, Faculty of Chemistry (Poland); Herrmann, Torsten [Université de Lyon/UMR 5280 CNRS/ENS Lyon/UCB Lyon 1, Institut des Sciences Analytiques, Centre de RMN à Très Hauts Champs (France); Ferrage, Fabien, E-mail: Fabien.Ferrage@ens.fr [Ecole Normale Supérieure – PSL Research University, Département de chimie (France)

    2016-01-15

    Nuclear magnetic resonance spectroscopy (NMR) can provide a great deal of information about structure and dynamics of biomolecules. The quality of an NMR structure strongly depends on the number of experimental observables and on their accurate conversion into geometric restraints. When distance restraints are derived from nuclear Overhauser effect spectroscopy (NOESY), stereo-specific assignments of prochiral atoms can contribute significantly to the accuracy of NMR structures of proteins and nucleic acids. Here we introduce a series of NOESY-based pulse sequences that can assist in the assignment of chiral CHD methylene protons in random fractionally deuterated proteins. Partial deuteration suppresses spin-diffusion between the two protons of CH{sub 2} groups that normally impedes the distinction of cross-relaxation networks for these two protons in NOESY spectra. Three and four-dimensional spectra allow one to distinguish cross-relaxation pathways involving either of the two methylene protons so that one can obtain stereospecific assignments. In addition, the analysis provides a large number of stereospecific distance restraints. Non-uniform sampling was used to ensure optimal signal resolution in 4D spectra and reduce ambiguities of the assignments. Automatic assignment procedures were modified for efficient and accurate stereospecific assignments during automated structure calculations based on 3D spectra. The protocol was applied to calcium-loaded calbindin D{sub 9k}. A large number of stereospecific assignments lead to a significant improvement of the accuracy of the structure.

  14. Permeation of protective clothing materials by methylene chloride and perchloroethylene.

    Science.gov (United States)

    Vahdat, N

    1987-07-01

    The permeation of methylene chloride and perchloroethylene through seven protective clothing materials was studied to determine the permeation parameters, and to investigate the effect of solubility (polymer weight gain) and material thickness on the permeation parameters. The materials tested were two different nitrile rubbers, neoprene, Combination (a blend of natural rubber, neoprene and nitrile), two different polyvinyl chlorides, and polyvinyl alcohol. Methylene chloride permeated through all materials, except PVA, with breakthrough times in the range of 2 to 8 min, and permeation rates in the range of 1250-5800 micrograms/cm2 X min. PVA and unsupported nitrile offered good protection against perchloroethylene with breakthrough time occurring after 2 hr. Perchloroethylene permeated through the other materials with breakthrough times in the range of 8 to 36 min and permeation rates in the range of 200 to 1600 micrograms/cm2 X min. It was shown that for both chemicals, there is a correlation between the solubility (weight gain) and the ratio of permeation rate to breakthrough time (PR/BT). For all material/chemical pairs, an increase in solubility, increased (PR/BT). The change in material thickness had an effect on breakthrough time and permeation rate, but no effect on normalized breakthrough time. An increase in thickness reduced permeation rate and increased breakthrough time.

  15. 21 CFR 700.19 - Use of methylene chloride as an ingredient of cosmetic products.

    Science.gov (United States)

    2010-04-01

    ... cosmetic products. 700.19 Section 700.19 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) COSMETICS GENERAL Requirements for Specific Cosmetic Products § 700.19 Use of methylene chloride as an ingredient of cosmetic products. (a) Methylene chloride has been...

  16. Scientific Basis for Paint Stripping: Elucidated Combinatorial Mechanism of Methylene Chloride and Phenol Based Paint Removers

    Science.gov (United States)

    2013-10-10

    Electron Microscope SERDP - Strategic Environmental Research and Development Program Tg – Glass Transition TGA – Thermal Gravimetric Analysis UV... analysis , visible microscopy and spectroscopy and vibrational spectroscopy to understand the mechanism of how methylene chloride based paint removers...allowed for analysis of the different components of methylene chloride based paint strippers. Methocel is the trade name of hydroxypropyl

  17. Upstaging of early colorectal cancers following improved lymph node yield after methylene blue injection

    DEFF Research Database (Denmark)

    Jepsen, Rikke Karlin; Ingeholm, Peter; Lund, Eva Charlotte Løbner

    2012-01-01

    Jepsen R K, Ingeholm P & Lund E L (2012) Histopathology 61, 788-794 Upstaging of early colorectal cancers following improved lymph node yield after methylene blue injection Aims:  To evaluate whether the use of intra-arterial methylene blue injection improves lymph node yield, and to determine...

  18. Film dosimeters based on methylene blue and methyl orange in polyvinyl alcohol

    DEFF Research Database (Denmark)

    Chung, W.H.; Miller, A.

    1994-01-01

    Polyvinyl alcohol (PVA) films containing methylene blue and methyl orange are useful as gamma and electron radiation dosimeters. Absorbed doses should not exceed 40 kGy for methylene blue and 500 kGy for methyl orange. Because PVA is water-soluble, the films may be made without toxic solvents. Th...

  19. Interim Report on Scientific Basis for Paint Stripping: Mechanism of Methylene Chloride Based Paint Removers

    Science.gov (United States)

    2010-10-18

    free unreacted functional groups. After observing satisfactory results, TGA analysis was performed to ensure the absence of nontraditional species...methylene chloride, EtOH, water and PhOH decomposed into small pieces, like MIL-85285, preventing DSC and TGA analysis . Exposure to methylene chloride and

  20. Singlet oxygen luminescence detecting in presence of hybrid associates of colloidal Ag2S quantum dots with methylene blue molecules

    Science.gov (United States)

    Ovchinnikov, O. V.; Kondratenko, T. S.; Smirnov, M. S.; Perepelitsa, A. S.; Grevtseva, I. G.; Vinokur, Y. A.; Aslanov, S. V.; Matsukovich, A. S.

    2016-12-01

    In our work we demonstrate some spectroscopic investigation of colloidal Ag2S QDs associates with methylene blue. The photosensitizing of singlet oxygen by associates of colloidal Ag2S QDs with methylene blue was found.

  1. Suspected serotonin syndrome in a patient being treated with methylene blue for ifosfamide encephalopathy.

    Science.gov (United States)

    McDonnell, A M; Rybak, I; Wadleigh, M; Fisher, D C

    2012-12-01

    Methylene blue has been used not only as a diagnostic agent, but also as an agent in the treatment of ifosfamide-induced encephalopathy (IIE) for several years. Recently, several cases of suspected serotonin syndrome have been reported in patients who received methylene blue in combination with serotonin active agents. Rodent models have revealed that methylene blue is a potent, reversible inhibitor of monoamine oxidase A. It is well known that serotonin active drugs, in combination with monoamine oxidase inhibitors can produce profound serotonin syndrome. To date, cases of serotonin syndrome, which resulted from concurrent methylene blue and serotonin active agents, have been published in the anesthesia literature. We report the first known case of serotonin syndrome in a patient receiving methylene blue for IIE.

  2. Evaluation of methylene diphenyl diisocyanate as an indoor air pollutant and biological assessment of methylene dianiline in the polyurethane factories

    Directory of Open Access Journals (Sweden)

    Mirmohammadi Mirtaghi

    2009-01-01

    Full Text Available Today many raw materials used in factories may have a dangerous effect on the physiological system of workers. One of them, which is widely used in the polyurethane factories, is diisocyanates. These compounds are widely used in surface coatings, polyurethane foams, adhesives, resins, elastomers, binders, and sealants. Exposure to diisocyanates causes irritation to the skin, mucous membranes, eyes, and respiratory tract. Methylene dianiline (MDA is a metabolite of methylene diphenyle diisocyanate (MDI, an excretory material of worker′s urine who are exposed to MDI. Around 100 air samples were collected among five factories by the Midget Impinger, which contained DMSO absorbent as a solvent and Tryptamine as a reagent. Samples were analyzed by high-performance liquid chromatography with an ECUV detector using the NIOSH 5522 method of sampling and analysis. Also, fifty urine samples were collected from workers by using William′s biological analysis method. The concentration of MDI in all air samples was more than 88 µg/m³, showing a high concentration of the pollutant in the workplaces in comparison with the NIOSH standard, and all the worker′s urine was contaminated by MDA. The correlation and regression tests were used to obtain statistical model for MDI and MDA that is useful for prediction of diisocyanates pollution situation in the polyurethane factories.

  3. ANTIVIRAL TESTS OF METHYLENE BLUE INJECTION ON VZV IN VITRO

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Methylene blue injection has a stronger direct inactivation on VZV in vitro. When the injection was diluted from 1:16 to 1:128, which was obvious (P<0.01 and P<0.05). The MIC was 1:222, the IC50 was 1:135 and IC90 was 1:77. The results of microcellculture method showed when the injection was diluted from 1:16 to 1:64, it also effectively inhibited the proliferation of VZV in WISH continuous cell-lines (P<0.01 and P<0.05). The MIC was 1:95, the IC50 was 1:45 and the IC90 was 1:21.

  4. Comparative Sorption of Methylene Blue onto Hydrophobic Clays

    Directory of Open Access Journals (Sweden)

    Alvaro D. Sponza

    2015-08-01

    Full Text Available Chemical modifications of clay to remove methylene blue (MB from aqueous solutions at room temperature were compared. Natural bentonite (NC was modified by cation exchange with hexadecyltrimethylammonium chloride (HC, bencyltriethylammonium chloride (BC, and tetramethylammonium chloride (TC to reverse the surface polarity of the hydrophilic bentonite. The adsorption of MB was studied and fitted by the adsorption theories of Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin. Equilibrium parameters were calculated, indicating that chemical modification did not improve the adsorption, due to the electrostatic adsorption mechanism. Specific surface area was determined, reporting the following trend: NC > TC > BC > HC. Isotherms show that TC is the best modified clay for the adsorption of MB with a capacity of 217 mg/g. Adsorbents were characterized by SEM and the determination of their point zero charge, indicating a charge reversal at pH 9.5 and a heterogeneous surface that is optimum for the adsorption of molecules and ions onto their surfaces.

  5. Preparation of photocrosslinkable polystyrene methylene cinnamate nanofibers via electrospinning.

    Science.gov (United States)

    Yi, Chuan; Nirmala, R; Navamathavan, R; Li, Xiang-Dan; Kim, Hak-Yong

    2011-10-01

    Nanoscaled photocrosslinkable polystyrene methylene cinnamate (PSMC) nanofibers were fabricated by electrospinning. The PSMC was prepared by the modification of polystyrene as a starting material via a two-step reaction process, chloromethylation and esterification. The chemical structure of PSMC was confirmed by 1H NMR and Fourier transform infrared spectroscopy (FT-IR). The photosensitivity of the PSMC was investigated using ultraviolet (UV) spectroscopic methods. Electrospun PSMC nanofiber mat showed excellent solubility in many organic solvents. UV irradiation of the electrospun mats led to photodimerization to resist dissolving in organic solvents. The morphology of the nanofiber was observed by scanning electron microscopy (SEM) and the result indicated that the average diameter of nanofibers is 350 nm and the crosslinked nanofibers were not collapsed after dipping into organic solvent showing good solvent-stability. This photocrosslinked nanofibers has the potential application in filtration, catalyst carrier and protective coating.

  6. Removal of methylene blue from aqueous solution by graphene oxide.

    Science.gov (United States)

    Yang, Sheng-Tao; Chen, Sheng; Chang, Yanli; Cao, Aoneng; Liu, Yuanfang; Wang, Haifang

    2011-07-01

    Graphene oxide (GO) is a highly effective absorbent of methylene blue (MB) and can be used to remove MB from aqueous solution. A huge absorption capacity of 714 mg/g is observed. At initial MB concentrations lower than 250 mg/L, the removal efficiency is higher than 99% and the solution can be decolorized to nearly colorless. The removal process is fast and more efficient at lower temperatures and higher pH values. The increase of ionic strength and the presence of dissolved organic matter would further enhance the removal process when MB concentration is high. The results indicate that GO can be applied in treating industrial effluent and contaminated natural water. The implications to graphene-based environmental technologies are discussed.

  7. Synthesis and properties of polybenzazoles containing flexible methylene in backbone

    Institute of Scientific and Technical Information of China (English)

    Xiaohui XU; Xiaoyun LIU; Chengjun ZHOU; Qixin ZHUANG; Zhewen HAN

    2008-01-01

    A novel series of polybenzazoles with rigid-rod benzoxazole cycle and soft methylene segment was designed and synthesized via solution condensation poly-merizations from 4,6-diamino-l,3-benzenediol dipho-sphate, terephthalic acid and aliphatic dicarboxylic acid. The structures of polybenzazoles were characterized by means of FT-IR,1H NMR and Wide-angle X-ray diffrac-tion (WAXRD). All the polymers show excellent thermal stability and the TdS was above 471℃, The intrinsic vis-cosities [η] of the polymers ranged from 0.8 to 0.9. The UV-Vis absorption peaks of the polymers in MSA were blue-shifted from 429 nm for PBO to 291 nm for PBOC7, and the Stokes shifts in PL spectra enlarged.

  8. [Research on degradation of methylene blue by coal bottom ash-microwave irradiation method].

    Science.gov (United States)

    Wu, Shi-Wei; Li, Na; Li, Guang-Zhe; Li, Guo-De

    2010-05-01

    Coal bottom ash is rich in metals and transition metals, and with microwave irradiation these metals can effectively degradate organic matter. Methylene blue degradation by coal bottom ash-microwave irradiation mainly through hydroxyl radicals to degrade organic matter, and metals and rare metals in bottom ash can be used as a catalyst for deep oxidation of organic matter, can reduce processing costs, and reduce environmental pollution. In the present paper the main parameters including the amount of coal bottom ash, H2O2 dosage and time of microwave irradiation were investigated. The UV-visible spectra of methylene blue were determined. The results show that: under coal bottom ash and H2O2 microwave condition the degeneration rate of methylene blue was almost 100%. The dosage of coal ash can accelerate the reaction process, speeding up the degradation of methylene blue. The increase of H2O2 may provide more * OH and speed up the reaction process, but when up to a certain amount, the influence is weakened. The lengthening of microwave time may enhance the reaction temperature, and urge the methylene blue to degrade completely. For 0.125 g x L(-1) of methylene blue, by adding 1.0 g coal bottom ash, 5 mL H2O2 and under mesotherm microwave temperature for 4 min, the methylene blue can be all degradated.

  9. Effect of lipiodol and methylene blue on the thoracoscopic preoperative positioning.

    Science.gov (United States)

    Zhang, Chuan-Yu; Yu, Hua-Long; Liu, Shi-He; Jiang, Gang; Wang, Yong-Jie

    2015-01-01

    The aim of this study was to compare and analyze the site-specific accuracy of mixture of lipiodol and methylene blue (MLM) (0.6 ml, 1:5) and pure methylene blue (0.5 ml) on the rabbit lungs. In this study, CT-guided percutaneous injection of MLM and methylene blue. Compare the staining degree by biopsy of lung tissue. Use 4 points system to evaluate the site-specific accuracy at 6h and 24 h after injection. For MLM, evaluate its radiopacity by radiation. When evaluate the positioning, 2 points mean acceptable, 3 points mean excellent. The results indicated that the staining range of MLM is obvious less than that of methylene blue (0.6 vs. 1.0 cm, Pmethylene blue (2.8 vs. 2.2, P = 0.01). About the staining abilities which are evaluated as excellent, MLM group accounts for 81%, methylene blue group accounts for 38% (P = 0.011). About the radiopacity which are evaluated as acceptable or excellent, MLM group accounts for 62%. With good direct vision, the suitable positioning rate of MLM can be 100%, which is better than that of methylene blue. In conclusion, percutaneous injection of MLM can be used to lung positioning. The result shows that use MLM is better than only using methylene blue. But it is necessary to do the investigation in human beings in order to confirm the feasibility of its clinical application.

  10. Fatal exposure to methylene chloride among bathtub refinishers - United States, 2000-2011.

    Science.gov (United States)

    2012-02-24

    In 2010, the Michigan Fatality Assessment and Control Evaluation program conducted an investigation into the death of a bathtub refinisher who used a methylene chloride-based paint stripping product marketed for use in aircraft maintenance. The program identified two earlier, similar deaths in Michigan. Program staff members notified CDC's National Institute for Occupational Safety and Health (NIOSH), which in turn notified the Occupational Safety and Health Administration (OSHA). In addition to the three deaths, OSHA identified 10 other bathtub refinisher fatalities associated with methylene chloride stripping agents that had been investigated in nine states during 2000-2011. Each death occurred in a residential bathroom with inadequate ventilation. Protective equipment, including a respirator, either was not used or was inadequate to protect against methylene chloride vapor, which has been recognized as potentially fatal to furniture strippers and factory workers but has not been reported previously as a cause of death among bathtub refinishers. Worker safety agencies, public health agencies, methylene chloride-based stripper manufacturers, and trade organizations should communicate the extreme hazards of using methylene chloride-based stripping products in bathtub refinishing to employers, workers, and consumers. Employers should strongly consider alternative methods of bathtub stripping and always ensure worker safety protections that reduce the risk for health hazards to acceptable levels. Employers choosing to use methylene chloride-based stripping products must comply with OSHA's standard to limit methylene chloride exposures to safe levels.

  11. Preparation of the methylene blue silica compound microcapsule; Mechirenburushirika fukugo maikuro kapuseru no chosei

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Koji [Yamagata University, Yamagata (Japan); Ono, Hideo

    1999-07-05

    By using methylene blue aqueous solution of the cationy for the dispersed phase of the W/0 emulsion, and using this for hydrolysis of TEOS and reaction field of the degeneracy conjunction, force - methylene blue compound microcapsule of 4.0 {mu}m mean particle sizes was prepared. When the water was supplied, though there was elution behavior of the methylene blue from this microcapsule in the condition that the methylene blue was fixed in the silica microcapsule without completely dissolving, the elution amount of methylene blue increased eluate isoelectric point silica, and the pH dependence was shown. Therefore, a part of methylene blue in dispersed phase combines with the silica in Coulomb force like during hydrolysis and degeneracy conjunction of TEOS, and it is fixed in the silica microcapsule resistant, and by the consistency of pH of the eluate, it is meanwhile regarded out for acidic as a dissolution of the methylene blue of the isoelectric point of the silica from the silica microcapsule. (translated by NEDO)

  12. Methylene blue prevents retinal damage in an experimental model of ischemic proliferative retinopathy.

    Science.gov (United States)

    Rey-Funes, Manuel; Larrayoz, Ignacio M; Fernández, Juan C; Contartese, Daniela S; Rolón, Federico; Inserra, Pablo I F; Martínez-Murillo, Ricardo; López-Costa, Juan J; Dorfman, Verónica B; Martínez, Alfredo; Loidl, César F

    2016-06-01

    Perinatal asphyxia induces retinal lesions, generating ischemic proliferative retinopathy, which may result in blindness. Previously, we showed that the nitrergic system was involved in the physiopathology of perinatal asphyxia. Here we analyze the application of methylene blue, a well-known soluble guanylate cyclase inhibitor, as a therapeutic strategy to prevent retinopathy. Male rats (n = 28 per group) were treated in different ways: 1) control group comprised born-to-term animals; 2) methylene blue group comprised animals born from pregnant rats treated with methylene blue (2 mg/kg) 30 and 5 min before delivery; 3) perinatal asphyxia (PA) group comprised rats exposed to perinatal asphyxia (20 min at 37°C); and 4) methylene blue-PA group comprised animals born from pregnant rats treated with methylene blue (2 mg/kg) 30 and 5 min before delivery, and then the pups were subjected to PA as above. For molecular studies, mRNA was obtained at different times after asphyxia, and tissue was collected at 30 days for morphological and biochemical analysis. Perinatal asphyxia produced significant gliosis, angiogenesis, and thickening of the inner retina. Methylene blue treatment reduced these parameters. Perinatal asphyxia resulted in a significant elevation of the nitrergic system as shown by NO synthase (NOS) activity assays, Western blotting, and (immuno)histochemistry for the neuronal isoform of NOS and NADPH-diaphorase activity. All these parameters were also normalized by the treatment. In addition, methylene blue induced the upregulation of the anti-angiogenic peptide, pigment epithelium-derived factor. Application of methylene blue reduced morphological and biochemical parameters of retinopathy. This finding suggests the use of methylene blue as a new treatment to prevent or decrease retinal damage in the context of ischemic proliferative retinopathy.

  13. Complications of Methylene Blue Dye in Breast Surgery: Case Reports and Review of the Literature

    Directory of Open Access Journals (Sweden)

    FJ Reyes, MB Noelck, C Valentino, L Grasso-LeBeau, JE Lang

    2011-01-01

    Full Text Available Introduction: Methylene blue dye has been used worldwide successfully with few complications in breast surgery. We present two different complications involving methylene blue: 1 skin and parenchymal necrosis when dye was injected in a subdermal fashion and 2 Mycoplasma infection caused by contaminated methylene blue in breast reduction surgery.Methods: We present two cases seen at the University of Arizona during 2008 and referred to a breast surgeon for management. We evaluated and managed complications of methylene blue dye injected by 2 referring surgeons for different indications. A review of the literature was performed.Results: The first case is a 67 year old female diagnosed with infiltrating ductal carcinoma of the left breast for which she was treated by her initial surgeon with left segmental mastectomy and sentinel node biopsy. The operating surgeon injected methylene blue in a subareolar subdermal fashion (distant from the primary tumor; unfortunately the patient suffered skin and breast necrosis requiring multiple surgical debridements and finally achieving delayed primary closure. The second case is a 45 year old female with infiltrating lobular carcinoma with a history of Mycoplasma infection secondary to methylene blue injected for breast reduction surgery. She required multiple debridements and had granulomas masquerading as cancer on MRI that confounded her extent of disease.Conclusions: The use of methylene blue dye in breast surgery is not without risk. In both cases methylene blue was responsible for complications requiring surgical debridement for local wound problems. In each case severe necrosis and infection were present. Methylene blue may cause not only significant morbidity, but may also produce cosmetically unsatisfactory results.

  14. Photocatalytic Degradation of Methylene Blue by Fe/ZnO/SiO2 Nanoparticles under Visiblelight

    OpenAIRE

    R. M. Mohamed; Mkhalid, I. A.; Baeissa, E. S.; M. A. Al-Rayyani

    2012-01-01

    The photocatalytic activity of Fe/ZnO/SiO2 catalysts under visible-light irradiation for the degradation of methylene blue was evaluated. The effect of pH, illumination time, amount of catalyst loaded, and initial dye concentration on the degradation efficiency of methylene blue was investigated. The results reveal that the optimum photocatalytic oxidation conditions of methylene blue are as follows: pH=4 and illumination time is 30 min, the amount of catalyst loading is 0.075 g/L and 50 ppm ...

  15. Degradation of methylene blue by radio frequency plasmas in water under ultraviolet irradiation.

    Science.gov (United States)

    Maehara, Tsunehiro; Nishiyama, Kyohei; Onishi, Shingo; Mukasa, Shinobu; Toyota, Hiromichi; Kuramoto, Makoto; Nomura, Shinfuku; Kawashima, Ayato

    2010-02-15

    The degradation of methylene blue by radio frequency (RF) plasmas in water under ultraviolet (UV) irradiation was studied experimentally. When the methylene blue solution was exposed to RF plasma, UV irradiation from a mercury vapor lamp enhanced degradation significantly. A lamp without power supply also enhanced degradation since weak UV light was emitted weakly from the lamp due to the excitation of mercury vapor by stray RF power. Such an enhancement is explained by the fact that after hydrogen peroxide is produced via the recombination process of OH radicals around the plasma, OH radicals reproduced from hydrogen peroxide via the photolysis process degrade methylene blue.

  16. Kinetics of Photocatalytic Degradation of Methylene Blue over TiO2 Particles in Aqueous Suspensions

    Institute of Scientific and Technical Information of China (English)

    史载锋; 范益群; 徐南平; 时钧

    2000-01-01

    The kinetics of photodegradation of methylene blue over UV light illuminated titania particles in aqueous suspensions has been studied with different initial methylene blue concentrations and TiO2 particle sizes. The degradation rate increases with the decrease of initial concentration and particle size. A quasi-experienced model for photodegradation rate is derived based mainly on the coinstantaneous effects of different initial concentrations and particle sizes. The mathematical relationships of model parameters with initial concentration and particle size are given. The model results of the photodegradation rate of methylene blue are coincident with the experimental data.

  17. Methylene Blue for Vasoplegia When on Cardiopulmonary Bypass During Double-Lung Transplantation.

    Science.gov (United States)

    Carley, Michelle; Schaff, Jacob; Lai, Terrance; Poppers, Jeremy

    2015-10-15

    Vasoplegia syndrome, characterized by hypotension refractory to fluid resuscitation or high-dose vasopressors, low systemic vascular resistance, and normal-to-increased cardiac index, is associated with increased morbidity and mortality after cardiothoracic surgery. Methylene blue inhibits inducible nitric oxide synthase and guanylyl cyclase, and has been used to treat vasoplegia during cardiopulmonary bypass. However, because methylene blue is associated with increased pulmonary vascular resistance, its use in patients undergoing lung transplantion has been limited. Herein, we report the use of methylene blue to treat refractory vasoplegia during cardiopulmonary bypass in a patient undergoing double-lung transplantation.

  18. Novel management of methylene blue extravasation: A case report and review of literature

    Directory of Open Access Journals (Sweden)

    Rashid Saeed Khokhar

    2015-01-01

    Full Text Available Methylene blue is a highly irritant drug and has been used intraoperatively. Its accidental extravasation can lead to tissue necrosis. In this report, a unique management is described, and the patient recovered without any morbidity.

  19. Fast photocatalytic degradation of methylene blue dye using a low-power diode laser.

    Science.gov (United States)

    Liu, Xianhua; Yang, Yulou; Shi, Xiaoxuan; Li, Kexun

    2015-01-01

    This study focused on the application of diode lasers as alternative light sources for the fast photocatalytic degradation of methylene blue. The photocatalytic decomposition of methylene blue in aqueous solution under 443 nm laser light irradiation was found to be technically feasible using Ag/AgCl nanoparticles as photocatalysts. The effects of various experimental parameters, such as irradiation time, light source, catalyst loading, initial dye concentration, pH, and laser energy on decolorization and degradation were investigated. The mineralization of methylene blue was confirmed by chemical oxygen demand analysis. The results demonstrate that the laser-induced photocatalytic process can effectively degrade methylene blue under the optimum conditions (pH 9.63, 4 mg/L MB concentration, and 1.4 g/L Ag/AgCl nanoparticles).

  20. Fast and considerable adsorption of methylene blue dye onto graphene oxide.

    Science.gov (United States)

    Zhang, Wenjie; Zhou, Chunjiao; Zhou, Weichang; Lei, Aihua; Zhang, Qinglin; Wan, Qiang; Zou, Bingsuo

    2011-07-01

    The quite efficient adsorption of methylene blue dye from an aqueous solution by graphene oxide was studied. The favorable electrostatic attraction is the main interaction between methylene blue and graphene oxide. As graphene oxide has the special nanostructural properties and negatively charged surface, the positively charged methylene blue molecules can be easily adsorbed on it. In the aqueous solution of methylene blue at 293 K, the adsorption data could be fitted by the Langmuir equation with a maximum adsorption amount of 1.939 mg/mg and a Langmuir adsorption equilibrium constant of 18.486 mL/mg. The adsorption amount increased with the increase of the solution pH (3-11), was not affected significantly by KCl under the examined condition and the adsorption process was exothermic in nature. The fast and considerable adsorption of graphene oxide could be regarded as a potential adsorbent for cationic dye removal in wastewater treatment process.

  1. Sonocatalytic degradation of methylene blue with TiO2 pellets in water.

    Science.gov (United States)

    Shimizu, Nobuaki; Ogino, Chiaki; Dadjour, Mahmoud Farshbaf; Murata, Tomoyuki

    2007-02-01

    A series of experiments were carried out to study the degradation of methylene blue by the irradiation of ultrasound onto TiO(2) in aqueous solution. A statistically significant decrease in the concentration of methylene blue was observed after 60 min irradiation. While the reduction was 22% of the initial concentration without H(2)O(2), addition of H(2)O(2) significantly enhanced the degradation of methylene blue for the TiO(2) containing system (85% reduction of the initial concentration). The addition of H(2)O(2) had no effect on the methylene blue degradation when the system contained Al(2)O(3). The degradation ratio of methylene blue was dependent on the amount of TiO(2) and also the specific surface area of TiO(2) in the solution. The effects of radical scavenging agents on the degradation of methylene blue were also investigated for the system with TiO(2). It was found that the radical scavenging agents dimethyl sulfoxide (DMSO), methanol, and mannitol suppressed the degradation, with DMSO being the most effective. The effect of pH on the degradation of methylene blue was further investigated. An U-shaped change in the concentration of methylene blue in the presence of TiO(2) was observed along with the change in pH values (pH 3-12), and the highest degradation ratio was observed at around pH 7. In conclusion, ultrasound irradiation of TiO(2) in aqueous solution resulted in significant generation of hydroxyl radicals, and this process may have potential for the treatment of organic dyes in wastewater.

  2. Photocatalytic Degradation of Methylene Blue using ZnO Nano-Particles

    OpenAIRE

    Rezaee, A.; H Masombaigi; Nasiri, A

    2009-01-01

    "nBackgrounds and Objectives: Textile industrial wastewaters are one of the important sources of environmental contaminants. In the recent years, use of advanced oxidation processes, by producing highly active and reactive components such as hydroxyl radicals has been proposed. The aim of this research is photocatalytic degradation of methylene blue dye using the ZnO-nanoparticle with UVA irradiation. "nMaterials and Methods: photocatalytic degradation of methylene blue color using the ZnO- n...

  3. Efficient alpha-Methylenation of Carbonyl Compounds in Ionic Liquids at Room Temperature

    OpenAIRE

    Vale, JA; Zanchetta, DF; Moran, PJS; RODRIGUES, JAR

    2009-01-01

    The application of several 1-butyl-3-methylimidazolium (BMIM) salt ionic liquids as solvent in the alpha-methylenation of carbonyl compounds at room temperature is reported. The ionic liquid [BMIM][NTf(2)] gave a clean reaction in a short time and good yields of several alpha-methylene carbonyl compounds. This ionic liquid was reused without affecting the reaction rates or yields over seven runs.

  4. The Adsorption Efficiency of Chemically Prepared Activated Carbon from Cola Nut Shells by on Methylene Blue

    OpenAIRE

    Julius Ndi Nsami; Joseph Ketcha Mbadcam

    2013-01-01

    The adsorption of methylene blue from aqueous solution onto activated carbon prepared from cola nut shell has been investigated under batch mode. The influence of major parameters governing the efficiency of the process such as, solution pH, sorbent dose, initial concentration, and contact time on the removal process was investigated. The time-dependent experimental studies showed that the adsorption quantity of methylene blue increases with initial concentration and decreasing adsorbent dosa...

  5. A nonradioactive assay for poly(a)-specific ribonuclease activity by methylene blue colorimetry.

    Science.gov (United States)

    Cheng, Yuan; Liu, Wei-Feng; Yan, Yong-Bin; Zhou, Hai-Meng

    2006-01-01

    A simple nonradioactive assay, which was based on the specific shift of the absorbance maximum of methylene blue induced by its intercalation into poly(A) molecules, was developed for poly(A)-specific ribonuclease (PARN). A good linear relationship was found between the absorbance at 662 nm and the poly(A) concentration. The assay conditions, including the concentration of methylene blue, the incubation temperature and time, and the poly(A) concentration were evaluated and optimized.

  6. Methylene Blue to Treat Protamine-induced Anaphylaxis Reactions. An Experimental Study in Pigs

    Directory of Open Access Journals (Sweden)

    Agnes Afrodite S. Albuquerque

    Full Text Available ABSTRACT Objective: To examine if methylene blue (MB can counteract or prevent protamine (P cardiovascular effects. Methods: The protocol included five heparinized pig groups: Group Sham -without any drug; Group MB - MB 3 mg/kg infusion; Group P - protamine; Group P/MB - MB after protamine; Group MB/P - MB before protamine. Nitric oxide levels were obtained by the nitric oxide/ozone chemiluminescence method, performed using the Nitric Oxide Analizer 280i (Sievers, Boulder, CO, USA. Malondialdehyde plasma levels were estimated using the thiobarbiturate technique. Results: 1 Groups Sham and MB presented unchanged parameters; 2 Group P - a Intravenous protamine infusion caused mean arterial pressure decrease and recovery trend after 25-30 minutes, b Cardiac output decreased and remained stable until the end of protamine injection, and c Sustained systemic vascular resistance increased until the end of protamine injection; 3 Methylene blue infusion after protamine (Group P/MB - a Marked mean arterial pressure decreased after protamine, but recovery after methylene blue injection, b Cardiac output decreased after protamine infusion, recovering after methylene blue infusion, and c Sustained systemic vascular resistance increased after protamine infusion and methylene blue injections; 4 Methylene blue infusion before protamine (Group MB/P - a Mean arterial pressure decrease was less severe with rapid recovery, b After methylene blue, there was a progressive cardiac output increase up to protamine injection, when cardiac output decreased, and c Sustained systemic vascular resistance decreased after protamine, followed by immediate Sustained systemic vascular resistance increase; 5 Plasma nitrite/nitrate and malondialdehyde values did not differ among the experimental groups. Conclusion: Reviewing these experimental results and our clinical experience, we suggest methylene blue safely prevents and treats hemodynamic protamine complications, from the

  7. Degradation of methylene blue using biologically synthesized silver nanoparticles.

    Science.gov (United States)

    Vanaja, M; Paulkumar, K; Baburaja, M; Rajeshkumar, S; Gnanajobitha, G; Malarkodi, C; Sivakavinesan, M; Annadurai, G

    2014-01-01

    Nowadays plant mediated synthesis of nanoparticles has great interest and achievement due to its eco-benign and low time consuming properties. In this study silver nanoparticles were successfully synthesized by using Morinda tinctoria leaf extract under different pH. The aqueous leaf extract was added to silver nitrate solution; the color of the reaction medium was changed from pale yellow to brown and that indicates reduction of silver ions to silver nanoparticles. Thus synthesized silver nanoparticles were characterized by UV-Vis spectrophotometer. Dispersity and morphology was characterized by scanning electron microscope (SEM); crystalline nature and purity of synthesized silver nanoparticles were revealed by X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). FTIR spectrum was examined to identify the effective functional molecules responsible for the reduction and stabilization of silver nanoparticles synthesized by leaf extract. The photocatalytic activity of the synthesized silver nanoparticles was examined by degradation of methylene blue under sunlight irradiation. Green synthesized silver nanoparticles were effectively degrading the dye nearly 95% at 72 h of exposure time.

  8. Biosorption of Methylene Blue by Chemically Modified Cellulose Waste

    Institute of Scientific and Technical Information of China (English)

    JIN Yanqiao; ZHANG Yizhuan; Lü Qiufeng; CHENG Xiansu

    2014-01-01

    Citric acid modified cellulose waste (CMCW) was prepared via esterification and used as a low-cost biosorbent for the removal of methylene blue (MB) from aqueous solutions. The effects of biosorbent concentration, initial pH of MB solution, biosorption temperature, contact time, and initial MB concentration on the biosorption of MB were investigated using batch biosorption technique under static conditions. The experimental results showed that CMCW exhibited excellent biosorption characteristics for MB. The maximum biosorption capacity of MB was up to 214.5 mg/g at an adsorption temperature of 293 K. The removal rate of MB onto CMCW reached the maximum at pH>4 and the biosorption reached an equilibrium at about 50 min. The kinetic data can be described well with the pseudo-second-order model and the isotherm data was found to fit the Langmuir isotherm with a monolayer adsorption capacity of 211.42 mg/g. The biosorption appears to be controlled by chemisorption and may be involved in surface adsorption and pore diffusion during the whole biosorption process.

  9. Photoacoustic lifetime imaging of dissolved oxygen using methylene blue

    Science.gov (United States)

    Ashkenazi, Shai

    2010-07-01

    Measuring distribution of dissolved oxygen in biological tissue is of prime interest for cancer diagnosis, prognosis, and therapy optimization. Tumor hypoxia indicates poor prognosis and resistance to radiotherapy. Despite its major clinical significance, no current imaging modality provides direct imaging of tissue oxygen. We present preliminary results demonstrating the potential of photoacoustic lifetime imaging (PALI) for noninvasive, 3-D imaging of tissue oxygen. The technique is based on photoacoustic probing of the excited state lifetime of methylene blue (MB) dye. MB is an FDA-approved water soluble dye with a peak absorption at 660 nm. A double pulse laser system (pump probe) is used to excite the dye and probe its transient absorption by detecting photoacoustic emission. The relaxation rate of MB depends linearly on oxygen concentration. Our measurements show high photoacoustic signal contrast at a probe wavelength of 810 nm, where the excited state absorption is more than four times higher than the ground state absorption. Imaging of a simple phantom is demonstrated. We conclude by discussing possible implementations of the technique in clinical settings and combining it with photodynamic therapy (PDT) for real-time therapy monitoring.

  10. Enhanced removal of Methylene Blue by electrocoagulation using iron electrodes

    Directory of Open Access Journals (Sweden)

    Mohamed S. Mahmoud

    2013-06-01

    Full Text Available The removal of pollutants from effluents by electrocoagulation has become an attractive method in recent years. The study deals with the enhancement of removal of Methylene Blue dye by using an electromagnetic field during the electrocoagulation process. Effects of electrolyte concentration, dye concentration, intensity and the direction of the electromagnet on the decolorization efficiency have been investigated. The formed ferric hydroxide flocs trap colloidal particles and make solid–liquid separation easier during the next stage. The electrocoagulation stages must be optimized in order to design an economically feasible process. The results showed that the optimum electrolysis was 10–20 min at a current density of 8 mA/cm2, while the optimum concentration of the electrolyte (NaOH was found to be 2 wt.% when the dye concentration was 50 mg/L. The utilization of an electromagnetic field enhanced the dye removal due to the induced motion of paramagnetic ions inside the solution. The power consumption required to remove the dye was reduced by 45% in the case of applying an electromagnetic field.

  11. Complexing Methylene Blue with Phosphorus Dendrimers to Increase Photodynamic Activity

    Directory of Open Access Journals (Sweden)

    Monika Dabrzalska

    2017-02-01

    Full Text Available The efficiency of photodynamic therapy is limited mainly due to low selectivity, unfavorable biodistribution of photosensitizers, and long-lasting skin sensitivity to light. However, drug delivery systems based on nanoparticles may overcome the limitations mentioned above. Among others, dendrimers are particularly attractive as carriers, because of their globular architecture and high loading capacity. The goal of the study was to check whether an anionic phosphorus dendrimer is suitable as a carrier of a photosensitizer—methylene blue (MB. As a biological model, basal cell carcinoma cell lines were used. We checked the influence of the MB complexation on its singlet oxygen production ability using a commercial fluorescence probe. Next, cellular uptake, phototoxicity, reactive oxygen species (ROS generation, and cell death were investigated. The MB-anionic dendrimer complex (MB-1an was found to generate less singlet oxygen; however, the complex showed higher cellular uptake and phototoxicity against basal cell carcinoma cell lines, which was accompanied with enhanced ROS production. Owing to the obtained results, we conclude that the photodynamic activity of MB complexed with an anionic dendrimer is higher than free MB against basal cell carcinoma cell lines.

  12. Methylene blue alleviates nuclear and mitochondrial abnormalities in progeria.

    Science.gov (United States)

    Xiong, Zheng-Mei; Choi, Ji Young; Wang, Kun; Zhang, Haoyue; Tariq, Zeshan; Wu, Di; Ko, Eunae; LaDana, Christina; Sesaki, Hiromi; Cao, Kan

    2016-04-01

    Hutchinson-Gilford progeria syndrome (HGPS), a fatal premature aging disease, is caused by a single-nucleotide mutation in the LMNA gene. Previous reports have focused on nuclear phenotypes in HGPS cells, yet the potential contribution of the mitochondria, a key player in normal aging, remains unclear. Using high-resolution microscopy analysis, we demonstrated a significantly increased fraction of swollen and fragmented mitochondria and a marked reduction in mitochondrial mobility in HGPS fibroblast cells. Notably, the expression of PGC-1α, a central regulator of mitochondrial biogenesis, was inhibited by progerin. To rescue mitochondrial defects, we treated HGPS cells with a mitochondrial-targeting antioxidant methylene blue (MB). Our analysis indicated that MB treatment not only alleviated the mitochondrial defects but also rescued the hallmark nuclear abnormalities in HGPS cells. Additional analysis suggested that MB treatment released progerin from the nuclear membrane, rescued perinuclear heterochromatin loss and corrected misregulated gene expression in HGPS cells. Together, these results demonstrate a role of mitochondrial dysfunction in developing the premature aging phenotypes in HGPS cells and suggest MB as a promising therapeutic approach for HGPS.

  13. Reduction of Methylene Green by EDTA: Kinetic and Thermodynamic Aspects

    Institute of Scientific and Technical Information of China (English)

    AZMAT Rafia; QAMAR Noshab; SAEED Amber; UDDIN Fahim

    2008-01-01

    The reduction of methylene green (MG) into protonated leuco dye with ethylenediamine tetraacetic acid (EDTA)in aqueous alkaline medium was studied spectrophotometrically at λmax 660 nm. EDTA behaved as an effective electron donor during the reduction of MG in an aerobic condition. Consumption of EDTA in the reduction of MG means that it is oxidized. This is an unexpected result since EDTA does not normally function as a reducing agent.The nitrogen-containing chelating agents with secondary or tertiary nitrogen behaved as an electron donor in photochemical reaction of dye. The rate of reduction depends upon pH in the same way as the base titration of EDTA.Effects of salt and temperature have been investigated for the reduction process. The salting agent KNO3 has been found to uniquely enhance the rate of reduction of MG by EDTA in the aerobic condition. Detailed kinetic and thermodynamic aspects have been discussed to realize the interaction between MG and EDTA. Kinetic studies revealed that reaction was sensitive and regeneration of oxidized form of the dye was observed. Reversible first order reaction kinetics with respect to EDTA, MG and NaOH was found.

  14. Fast photocatalytic degradation of methylene blue dye using a low-power diode laser

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xianhua, E-mail: lxh@tju.edu.cn [School of Environmental Science and Engineering, Tianjin University, No. 92, Weijin Road, Nankai District, Tianjin 300072 (China); Yang, Yulou; Shi, Xiaoxuan [School of Environmental Science and Engineering, Tianjin University, No. 92, Weijin Road, Nankai District, Tianjin 300072 (China); Li, Kexun, E-mail: likx@nankai.edu.cn [School of Environmental Science and Engineering, Nankai University, Tianjin 300074 (China)

    2015-02-11

    Highlights: • Photocatalytic oxidation of methylene blue was studied under laser light irradiation. • Fast removal of methylene blue from aqueous solution was achieved. • The photocatalyst Ag/AgCl is efficient and stable under 443 nm laser light irritation. • Diode laser is a good light source for photocatalytic degradation of dyes. - Abstract: This study focused on the application of diode lasers as alternative light sources for the fast photocatalytic degradation of methylene blue. The photocatalytic decomposition of methylene blue in aqueous solution under 443 nm laser light irradiation was found to be technically feasible using Ag/AgCl nanoparticles as photocatalysts. The effects of various experimental parameters, such as irradiation time, light source, catalyst loading, initial dye concentration, pH, and laser energy on decolorization and degradation were investigated. The mineralization of methylene blue was confirmed by chemical oxygen demand analysis. The results demonstrate that the laser-induced photocatalytic process can effectively degrade methylene blue under the optimum conditions (pH 9.63, 4 mg/L MB concentration, and 1.4 g/L Ag/AgCl nanoparticles)

  15. Can methylene blue only be used in sentinel lymph node biopsy for breast cancer?

    Science.gov (United States)

    Golshan, Mehra; Nakhlis, Faina

    2006-01-01

    Sentinel lymph node biopsy (SLNB) has become an accepted standard of care to stage the axilla for clinically node-negative early stage breast cancer. In experienced hands, studies have shown an acceptable rate of identification of the sentinel lymph node (SLN) with blue dye only. Lymphazurin is occasionally associated with severe allergic reaction, including anaphylaxis and death. The use of methylene blue alone as a method of identifying the SLN in breast cancer has been reported once previously in the literature. Methylene blue may be an acceptable alternative with fewer deleterious side effects. Medical records of patients, who underwent sentinel node mapping between September 2003 and March 2005 by two surgeons at an academic medical center were reviewed. SLN mapping was performed by periareolar injection of 5 cc of 1% methylene blue. All patients with positive SLNs underwent completion axillary node dissection. During the study period, 141 consecutive patients with clinically node-negative axillas and without evidence of inflammatory breast cancer underwent SLNB with injection of methylene blue only. A SLN was identified in 136 of 141 patients (96.5%). Thirty-three of 136 SLNs (24%) harbored metastatic disease. No cases of anaphylaxis were noted. In experienced hands, methylene blue alone is a highly sensitive method of detecting SLNs. Avoiding the greater frequency of allergic reactions seen with lymphazurin is an important advantage of methylene blue.

  16. 粘菌素、杆菌肽及维吉尼霉素的检测方法研究进展%Advance on detection methods of colistin, bacitracin and virginiamycin

    Institute of Scientific and Technical Information of China (English)

    罗方方; 钱卓真; 朱世超; 吴成业

    2012-01-01

    Focus on the detection problems of colistin, bacitracin and virginiamycin drug residues, this paper introduces different methods at home and abroad to detect these three kinds of substances in food of animal ori- gin and feed, analyses and compares the advantages and disadvantages of microbiological, ELISA, capillary electrophoresis, HPLC and LC - MS. Finally HPLC and LC - MS are considered as the suited methods to quantitative and confirmatory analyse the residues of these substances in aquatic products.%围绕水产品中粘菌素、杆菌肽及维吉尼霉素药物残留的检测问题,本文主要介绍了国内外动物源性食品和饲料中这3种药物残留的检测方法,分析比较了微生物法、酶联免疫分析法、毛细管电泳法、高效液相色谱法和液相色谱串联质谱法等几种检测方法的优缺点,认为HPLC法和Lc—MS法比较适合于水产品中这类药物残留的定量和确证检测。

  17. Methylene blue solder re-absorption in microvascular anastomoses

    Science.gov (United States)

    Birch, Jeremy F.; Hepplewhite, J.; Frier, Malcolm; Bell, Peter R. F.

    2003-06-01

    Soldered vascular anastomoses have been reported using several chromophores but little is known of the optimal conditions for microvascular anastomosis. There are some indications of the optimal protein contents of a solder, and the effects of methylene blue on anastomotic strength. The effects of varying laser power density in vivo have also been described, showing a high rate of thrombosis with laser power over 22.9Wcm-2. However no evidence exists to describe how long the solder remains at the site of the anastomosis. Oz et al reported that the fibrin used in their study had been almost completely removed by 90 days but without objective evidence of solder removal. In order to address the issue of solder re-absorption from the site of an anastomosis we used radio-labelled albumin (I-125) incorporated into methylene blue based solder. This was investigated in both the situation of the patent and thrombosed anastomosis with anastomoses formed at high and low power. Iodine-125 (half life: 60.2 days) was covalently bonded to porcine albumin and mixed with the solder solution. Radio-iodine has been used over many years to determine protein turnover using either I-125 or I-131. Iodine-125 labelled human albumin is regularly used as a radiopharmaceutical tool for the determination of plasma volume. Radio-iodine has the advantages of not affecting protein metabolism and the label is rapidly excreted after metabolic breakdown. Labelling with chromium (Cr-51) causes protein denaturation and is lost from the protein with time. Labelled albumin has been reported in human studies over a 21-day period, with similar results reported by Matthews. Most significantly McFarlane reported a different rate of catabolism of I-131 and I-125 over a 22-day period. The conclusion from this is that the rate of iodine clearance is a good indicator of protein catabolism. In parallel with the surgery a series of blank standards were prepared with a known mass of solder to correct for isotope

  18. Methylene blue for clinical anaphylaxis treatment: a case report

    Directory of Open Access Journals (Sweden)

    Janine Moreira Rodrigues

    Full Text Available CONTEXT AND OBJECTIVE: Nitric oxide has a pathophysiological role in modulating systemic changes associated with anaphylaxis. Nitric oxide synthase inhibitors may exacerbate bronchospasm in anaphylaxis and worsen clinical conditions, with limited roles in anaphylactic shock treatment. The aim here was to report an anaphylaxis case (not anaphylactic shock, reversed by methylene blue (MB, a guanylyl cyclase inhibitor. CASE REPORT: A 23-year-old female suddenly presented urticaria and pruritus, initially on her face and arms, then over her whole body. Oral antihistamine was administered initially, but without improvement in symptoms and signs until intravenous methylprednisolone 500 mg. Recurrence occurred after two hours, plus vomiting. Associated upper respiratory distress, pulmonary sibilance, laryngeal stridor and facial angioedema (including erythema and lip edema marked the evolution. At sites with severe pruritus, petechial lesions were observed. The clinical situation worsened, with dyspnea, tachypnea, peroral cyanosis, laryngeal edema with severe expiratory dyspnea and deepening unconsciousness. Conventional treatment was ineffective. Intubation and ventilatory support were then considered, because of severe hypoventilation. But, before doing that, based on our previous experience, 1.5 mg/kg (120 mg bolus of 4% MB was infused, followed by one hour of continuous infusion of another 120 mg diluted in dextrose 5% in water. Following the initial intravenous MB dose, the clinical situation reversed completely in less than 20 minutes, thereby avoiding tracheal intubation. CONCLUSION: Although the nitric oxide hypothesis for MB effectiveness discussed here remains unproven, our intention was to share our accumulated cohort experience, which strongly suggests MB is a lifesaving treatment for anaphylactic shock and/or anaphylaxis and other vasoplegic conditions.

  19. Photoinduced protein modifications by methylene blue and naproxen.

    Science.gov (United States)

    Bracchitta, Giuseppina; Catalfo, Alfio; De Guidi, Guido

    2012-12-01

    HPLC and emission spectroscopy were used to investigate UVA photosensitization of methylene blue (MB) or naproxen (NAP) towards bovine serum albumin (BSA). In addition, time resolved singlet oxygen measurements were carried out. The most stable drug : protein adducts stoichiometry of MB-BSA (1 : 1) and NAP-BSA (9 : 1) were verified by means of binding constant determination. UVA photosensitization of MB or NAP on BSA was studied by monitoring tryptophan (Trp) residue integrity. The sensitized photodegradation of the BSA resulted in different degrees of Trp damage. Thus, protein damage was determined by quantitative measurements of the different Trp (photo)-products. Indeed, many of these Trp derivatives are diagnostic for the photosensitization mechanism and some of them, for the first time in this work, were obtained by UVA photosensitization in proteins. The analysis of quantum yields of the photoproduct distribution allowed to weigh up the type I/II contribution to the UVA photosensitization mechanism. As expected, additional experiments in deuterated solvent resulted in an increase of the photodegradation quantum yields for those species where a singlet oxygen mechanism was involved. The UVA mediated generation of these Trp derivatives is consistent with the occurrence of singlet oxygen formation (almost dominant in MB), and photoionization (significant in NAP) within the protein matrix. Additional experiments at lower NAP concentration, as well as with human serum albumin (which differs for Trp content and, partially, localization), support further the molecular mechanism of photosensitization proposed. The results obtained in the case of this more complex system are in agreement with the free Trp model, even if, in almost all cases, the Trp photoproduct formation quantum yields are lower, due to the higher number of sensitization targets in the proteins.

  20. Separation of Methylene Blue Dye from Aqueous Solution Using Triton X-114 Surfactant

    Directory of Open Access Journals (Sweden)

    Arunagiri Appusamy

    2014-01-01

    Full Text Available In this study, the interaction energy between Triton X-114 surfactant + methylene blue or water and methylene blue + water was investigated using Hartree-Fock (HF theory with 6-31G* basis set. The results of structures and interaction energies show that these complexes have good physical and chemical interactions at atom and molecular levels. However, the Triton X-114 surfactant + methylene blue complex shows stronger molecular interaction compared to other complexes systems. The order of the interaction energy is 4303.472023 (Triton X-114 surfactant + water > -1222.962 (methylene blue + water > -3573.28 (Triton X-114 surfactant + methylene blue kJ·mole−1. Subsequently, the cloud point extraction was carried out for 15 ppm of methylene blue in a mixture at 313.15 and 323.15 K over the surfactant concentration range from 0.01 M to 0.1 M. From the measured data, the excess molar volume was calculated for both phases. The results show a positive deviation in the dilute phase and a negative deviation in the surfactant rich phase. It is confirmed that the interaction between Triton X-114 and methylene blue is stronger than other complex systems due to the presence of chemical and structural orientation. The concentration of dyes and surfactant in the feed mixture and temperature effect in both phases has been studied. In addition, the thermodynamics feasibility and efficiency of the process have also been investigated.

  1. Low-temperature synthesis and investigations on photocatalytic activity of nanoparticles BiFeO3 for methylene blue and methylene orange degradation and some toxic organic compounds

    Science.gov (United States)

    Nhiem Dao, Ngoc; Luu, Minh Dai; Chuc Pham, Ngoc; Dung Doan, Trung; Nguyen, Thi Ha Chi; Bac Nguyen, Quang; Lim Duong, Thi

    2016-12-01

    The photocatalytic BiFeO3 perovskite nanoparticles were fabricated by gel combustion method using polyvinyl alcohol and corresponding metal nitrate precursors under the optimum mild conditions such as pH 2, gel formation temperature of 80 °C, metal/polyvinyl alcohol molar ratio of 1/3, metal molar ratio Bi/Fe of 1/1 and calcination temperature at 500 °C for 2 h. The prepared sample was characterized by x-ray diffraction, field scanning electron microscopy, transmission electron microscopy, Brunauer-Emmetl-Teller nitrogen adsorption method at 77 K, energy dispersive x-ray spectroscopy, ultraviolet-visible light spectrophotometry, and thermal analysis. The effects of molar ratios of starting material and calcination temperature on phase formation and morphology were investigated. The degradation of methylene blue, methylene orange and some toxic organic compounds such as phenol and diazinon under visible light irradiation by photocatalytic BiFeO3 nanoparticles were evaluated at different parameters and conditions such as the light intensity determined from the light source to the measured sample, the addition H2O2, reaction time and the regeneration performance. Obtained results showed that the synthesized perovskite BiFeO3 nanoparticles for the optimized sample have a size smaller than 50 nm and the high mean surface area of 50 m2 g-1. Degradation efficiency was almost 90.0% for methylene blue and 80.0% for methylene orange with added H2O2 after 30 min of reaction. After the 3rd time of regeneration, the BiFeO3 nanoparticles still have 92.8% of the degradation performance for removing methylene blue. Phenol and diazinon toxic compound were degraded with the performance of 92.42% and 85.7%, respectively, for 150 min

  2. Elaeagnus angustifolia STONE AS A LOW-COST BIOSORBENT PRECURSOR FOR REMOVAL OF METHYLENE BLUE FROM AQUEOUS SOLUTION

    OpenAIRE

    KILIÇ, Murat; POYRAZ, Zakir

    2012-01-01

    In this study, the removal of methylene blue from aqueous solutions by biosorption onto Elaeagnus angustifolia stone has investigated. Optimum biosorption conditions have determined as a function of pH, biosorbent dosage, initial methylene blue concentration, contact time and temperature of the solution for the removal of methylene blue. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models have used to describe the biosorption isotherm model. The experimental data have fitted t...

  3. Sentinel node biopsy in carcinoma penis using methylene blue dye technique

    Directory of Open Access Journals (Sweden)

    Rohan Vinayak

    2009-01-01

    Full Text Available Purpose : Penile carcinoma is a common disease in India. This paper shows the results of sentinel node biopsy using methylene blue and discusses the incidence of false-negative rates. Materials and Methods: From September 2005 to March 2008, 22 newly diagnosed penile carcinoma patients (T1, T2, N0 were included in this prospective study. Intraoperative lymphatic mapping was done using methylene blue dye and the sentinel node was identified and removed. Lymphadenectomy was performed for positive inguinal lymph node metastasis. Results : There were 22 patients (mean age 52.7. The tumors were mostly located in the glans (73%. Eighty six percent was T1 lesions and 14% was T2. Ninety one percent of the patients underwent partial penectomy, and 9% underwent total penectomy. Sentinel node was identified in 20 patients (90.9%. In total, 49 sentinel nodes were identified (2.45 nodes per person. Only one patient had a positive pathological lymph node metastasis at the time of the surgery. Additionally, two patients became inguinal lymph node positive at the follow-up. This data yielded a sensitivity rate of 33% and a false-negative rate of 66%. There were no complications due to methylene blue. Conclusion : Sentinel node biopsy using only methylene blue for penile carcinoma has a very low sensitivity and a high false-negative rate. However, methylene blue can be used as a substitute for lymphazurin.

  4. Enhanced Photocatalytic Performance of NiO-Decorated ZnO Nanowhiskers for Methylene Blue Degradation

    Directory of Open Access Journals (Sweden)

    I. Abdul Rahman

    2014-01-01

    Full Text Available ZnO nanowhiskers were used for photodecomposition of methylene blue in aqueous solution under UV irradiation. The rate of methylene blue degradation increased linearly with time of UV irradiation. 54% of degradation rate was observed when the ZnO nanowhiskers were used as photocatalysts for methylene blue degradation for 80 min under UV irradiation. The decoration of p-type NiO nanoparticles on n-type ZnO nanowhiskers significantly enhanced photocatalytic activity and reached 72% degradation rate of methylene blue by using the same method. NiO-decorated ZnO was recycled for second test and shows 66% degradation from maximal peak of methylene blue within the same period. The increment of photocatalytic activity of NiO-decorated ZnO nanowhiskers was explained by the extension of the electron depletion layer due to the formation of nanoscale p-n junctions between p-type NiO and n-type ZnO. Hence, these products provide new alternative proficient photocatalysts for wastewater treatment.

  5. Photocatalytic Degradation of Methylene Blue using ZnO Nano-Particles

    Directory of Open Access Journals (Sweden)

    A Rezaee

    2009-11-01

    Full Text Available "nBackgrounds and Objectives: Textile industrial wastewaters are one of the important sources of environmental contaminants. In the recent years, use of advanced oxidation processes, by producing highly active and reactive components such as hydroxyl radicals has been proposed. The aim of this research is photocatalytic degradation of methylene blue dye using the ZnO-nanoparticle with UVA irradiation. "nMaterials and Methods: photocatalytic degradation of methylene blue color using the ZnO- nanoparticles excited with UVA irradiation. In this research, photocatalytic degradation of methylene blue dye was study using different concentration of ZnO-nanoparticles under UVA irradiation in a batch reactor. "nResults: The results of this research show that removal of methylene blue dye has direct correlation with UVA intensity. The best results of dye degradation were reported in concentration of 150 mg/L ZnO nano-particles and the radiation intensity of 240 µW/cm2. Rate of dye removal was decrease with increasing of color concentration. Subsequent of color degradation, the initial COD were decresed by %60. "nConclusion: The photocatalytic degradation process using ZnO nano-particles under UVA irradiation could be remove the methylene blue dye and 60% of COD.

  6. Urea enhances the photodynamic efficiency of methylene blue.

    Science.gov (United States)

    Nuñez, Silvia C; Yoshimura, Tania M; Ribeiro, Martha S; Junqueira, Helena C; Maciel, Cleiton; Coutinho-Neto, Maurício D; Baptista, Maurício S

    2015-09-01

    Methylene blue (MB) is a well-known photosensitizer used mostly for antimicrobial photodynamic therapy (APDT). MB tends to aggregate, interfering negatively with its singlet oxygen generation, because MB aggregates lean towards electron transfer reactions, instead of energy transfer with oxygen. In order to avoid MB aggregation we tested the effect of urea, which destabilizes solute-solute interactions. The antimicrobial efficiency of MB (30 μM) either in water or in 2M aqueous urea solution was tested against a fungus (Candida albicans). Samples were kept in the dark and irradiation was performed with a light emitting diode (λ = 645 nm). Without urea, 9 min of irradiation was needed to achieve complete microbial eradication. In urea solution, complete eradication was obtained with 6 min illumination (light energy of 14.4 J). The higher efficiency of MB/urea solution was correlated with a smaller concentration of dimers, even in the presence of the microorganisms. Monomer to dimer concentration ratios were extracted from the absorption spectra of MB solutions measured as a function of MB concentration at different temperatures and at different concentrations of sodium chloride and urea. Dimerization equilibrium decreased by 3 and 6 times in 1 and 2M urea, respectively, and increased by a factor of 6 in 1M sodium chloride. The destabilization of aggregates by urea seems to be applied to other photosensitizers, since urea also destabilized aggregation of Meso-tetra(4-n-methyl-pyridyl)porphyrin, which is a positively charged porphyrin. We showed that urea destabilizes MB aggregates mainly by causing a decrease in the enthalpic gain of dimerization, which was exactly the opposite of the effect of sodium chloride. In order to understand this phenomenon at the molecular level, we computed the free energy for the dimer association process (ΔG(dimer)) in aqueous solution as well as its enthalpic component in aqueous and in aqueous/urea solutions by molecular dynamics

  7. Complexation between carrageenan and methylene blue for sensor design

    Science.gov (United States)

    Ling, Yew Pei; Heng, Lee Yook

    2013-11-01

    Theoretical studies on the methylene blue (MB)-carrageenans complexation at solution and solid states have been carried out via ultraviolet spectrophotoscopy and reflectometry methods. The equilibrium constant (Ka) of the MBcarrageenans complexation follows the order of Iota > Lambda > Kappa carrageenans, which indicated Iota-carrageenan forms a stable complex. MB-carrageenan complexation reaction showed decrease in Ka value from 210.71 ppm-1 to 114.57 ppm-1 when the reaction temperature increased from 298 K to 323 K. Le Chatelier's principle and mass action law explained that the MB-carrageenan complexation was an exothermic reaction (ΔH=-18.54 kJmol-1) that release heat. Thus MB-carrageenan complex was less stable at high temperature and tend to dissociate into free MB and carrageenan molecules. It was also supported by the van't Hoff equation. The reaction is a spontaneous process (ΔG=-13.23 kJmol-1) where the randomness of the molecules reduced (ΔS=-17.83 Jmol-1K-1) due to complexation. Besides, linear regression of the concentration and absorption of the MB-carrageenan reaction obeys the Beer Lambert law, which elucidated that the complexation process was not affected by any concentration dependent factors such as aggregation and self-quenching. Moreover, linear Benesi Hilderbrend plot revealed that the interaction between MB and carrageenan was a reversible and stoichiometric reaction with 1:1 ratio. However, the molar extinction coefficient (ɛ) and molar adsorption coefficient (μa) of the MB-carrageenan complex were lower compared to free MB, described that the complex was less adsorptive. The sensor constructed based on these theoretical investigations showed response behavior that was similar with solution test as both have attraction for carrageenans in the sequence of Iota-, Lambda-, Kappa- carrageenans. Likewise, carrageenan sensor was more selective towards Iota-carrageenan than to Lambda- and Kappa-carrageenans, and no response observed when

  8. Methylene blue and parathyroid adenoma localization: Three new cases of a rare cutaneous complication.

    Science.gov (United States)

    Lieberman, Elliot D; Thambi, Rakhi; Pytynia, Kristen B

    2016-02-01

    Methylene blue has been safely used for the localization of parathyroid glands during parathyroidectomy, and only a few adverse effects have been documented. Methylene blue administration as a cause of pulse-oximetry-related skin injury is extremely rare. We describe 2 such cases in patients who developed a blister on the second digit at the pulse oximetry site after an uncomplicated excision of a parathyroid adenoma. In another case, a patient became bradycardic intraoperatively; she was successfully resuscitated, but she incurred a second-degree burn at the pulse oximetry site. In all 3 cases, the burns resolved with local wound care. We publish this report to alert surgeons and anesthesiologists to the risk of skin complications with the use of high-dose intraoperative methylene blue.

  9. Synthesis of mesoporous TiO2-curcumin nanoparticles for photocatalytic degradation of methylene blue dye.

    Science.gov (United States)

    Abou-Gamra, Z M; Ahmed, M A

    2016-07-01

    Herein, we demonstrate a facile route for synthesis a new photocatalyst based on TiO2-curcumin nanoparticles for photodegradation of methylene blue dye under UV and visible light irradiation. The photocatalyst was prepared by sol-gel method using chitosan as biodegradable polymer. The crystalline and the nanostructure were characteristic X-ray diffraction [XRD], adsorption-desorption isotherm and high resolution transmission electron microscopy [HRTEM]. However, the optical features of the samples were investigated by a UV-visible spectrophotometer. It is obvious to notice the removal of the majority of methylene blue dye on a pure titania surface via adsorption mechanism owing to the high surface area and to the organized mesoporous nature of the solid sample. Incorporation of curcumin on titania surface changes the removal direction from adsorption to the photocatalytic pathway. Various photocatalytic experiments were performed to investigate the influence of initial dye concentration, weight of catalyst, stirring and light intensity on the photocatalytic degradation of methylene blue as primary pollutant model. Chemical oxygen demand [COD] test confirms the complete degradation of methylene blue dye. The exceptional photocatalytic reactivity of titania-curcumin nanoparticles is referred to reduction in band gap energy and to the facility of electron transfer from II* curcumin energy level to titania conduction band which increases the concentration of reactive oxygen superoxide radicals which in turn prevents the electron-hole recombination. The effect of various scavengers on the methylene blue dye degradation was investigated using ethanol, ascorbic acid and methyl viologen. The results have pointed out that O2(-) and HO(.) are considered the main active species in the degradation process. A plausible pathway and mechanism for the photocatalytic degradation of methylene blue by titania-curcumin nanoparticles were illustrated.

  10. Lymph node mapping in rabbit liver cancer with nanocarbon and methylene blue injecta

    Institute of Scientific and Technical Information of China (English)

    Zhong Li

    2013-01-01

    Objective: To discuss the value of lymph node mapping in rabbit liver cancer with nanocarbon and methylene blue injecta. Methods: Rabbit liver cancer model was established by transplanting VX2 cells with laparotomy in celiac planting method. Twenty Japan white rabbits were divided into two groups randomly. Each group had 10 rabbits. Lymph node mapping in two groups rabbit liver cancer were observed. Two groups rabbit liver cancer and local lymph nodes were removed. The number and location of local lymph nodes were recorded, and then the samples were obtained from both groups. Results: The lymph nodes dyed time was (100.50±29.92) s in nanocarbon group, and (11.20±4.18) s in methylene blue group with statistical significance between two groups (P=0.000). In the comparison of lymph node fading time, nanocarbon group was (2.22±0.74) h, methylene blue group was (1.63±0.54) h, nanocarbon group was longer than the methylene blue group, but without statistical significance (P=0.058). The accuracy was 87.5%(35/40) in methylene blue group, while, the nanocarbon group was 87.2% (34/39) , with statistical significance (P=1.000). Conclusions: Experimental results show that application of nanocarbon injection and methylene blue injection during resection of liver cancer and local lymph nodes in rabbit liver cancer model has obvious tracer function in liver cancer and lymphatic drainage. It can reduce the complexity and risk of the operation, and avoid the blindness in the process of traditional lymph node dissection surgery. Besides, they can effectively reduce the number of residual lymph nodes after operation. It can achieve the lymph node dissection more thoroughly, promptly, easily and safely.

  11. Reflection mode holographic recording in methylene blue-sensitized polyvinyl alcohol acrylamide films

    Indian Academy of Sciences (India)

    C S Rajesh; R Anjana; S S Sreeroop; C Sudha Kartha

    2014-02-01

    Photopolymer systems can produce good image quality holograms that does not require any post-processing and are environmentally stable with good diffraction efficiency. The present work reports the development of a methylene blue-sensitized polyvinyl alcohol acrylamide (MBPVA/AA) photopolymer system for recording white light reflection holograms. Reflection gratings were recorded in the photopolymer films with different concentrations of methylene blue (MB). Various parameters affecting the holographic properties of the samples were also studied. The holographic performance of the material is found to depend on its chemical composition and the recording parameters.

  12. Sunlight-Induced Photochemical Degradation of Methylene Blue by Water-Soluble Carbon Nanorods

    Directory of Open Access Journals (Sweden)

    Anshu Bhati

    2016-01-01

    Full Text Available Water-soluble graphitic hollow carbon nanorods (wsCNRs are exploited for their light-driven photochemical activities under outdoor sunlight. wsCNRs were synthesized by a simple pyrolysis method from castor seed oil, without using any metal catalyst or template. wsCNRs exhibited the light-induced photochemical degradation of methylene blue used as a model pollutant by the generation of singlet oxygen species. Herein, we described a possible degradation mechanism of methylene blue under the irradiation of visible photons via the singlet oxygen-superoxide anion pathway.

  13. Is Cytox 3522 (10% methylene-bis-thiocyanate) a human skin sensitizer?

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Hamann, K

    1983-01-01

    Methylene-bis-thiocyanate is an antimicrobial agent in Cytox 3522 (American Cyanamid Corporation) and Nalco 206 (Nalco Chemical Company). Both are wide-spectrum industrial biocides. Cytox 3522 showed a strong sensitization potential in guineau pigs using the Guinea Pig Maximization Test and the O......Methylene-bis-thiocyanate is an antimicrobial agent in Cytox 3522 (American Cyanamid Corporation) and Nalco 206 (Nalco Chemical Company). Both are wide-spectrum industrial biocides. Cytox 3522 showed a strong sensitization potential in guineau pigs using the Guinea Pig Maximization Test...

  14. ALTERNATIVE AND COMPLEMENTARY SYNTHETIC APPROACHES TO β CARBOXY-α-METHYLENE-γ-BUTYROLACTONE ETHYL ESTERS

    Directory of Open Access Journals (Sweden)

    Gwenaëlle Liberge

    2011-12-01

    Full Text Available Alternative synthetic approaches to a variety of β substituted and carboxylated α-methylene-γ-butyrolactones have been developed. In the first approach the mandatory methylene unit was incorporated on precursor compounds at early stage of the synthesis on reliance with Horner-Emmons protocol. In the alternative approach which further tolerates multifarious substituents at γ-position of the lactone template the unsaturated moiety α to the lactone carbonyl group is connected at a later stage through a deprotonation / methoxymethylation / elimination sequence.

  15. A dose-finding study of methylene blue to inhibit nitric oxide actions in the hemodynamics of human septic shock

    NARCIS (Netherlands)

    N.P. Juffermans; M.G. Vervloet; C.R. Daemen-Gubbels; J.M. Binnekade; M.D. de Jong; A.J. Groeneveld

    2010-01-01

    Methylene blue increases blood pressure and myocardial function in septic shock mainly by inhibiting nitric oxide (NO) actions. However, a dose-dependency of methylene blue has not been established. Therefore, the compound is currently used as rescue treatment only. To evaluate dose-dependency, a pr

  16. Catalytic liquid marbles: Ag nanowire-based miniature reactors for highly efficient degradation of methylene blue.

    Science.gov (United States)

    Miao, Yue-E; Lee, Hiang Kwee; Chew, Wee Shern; Phang, In Yee; Liu, Tianxi; Ling, Xing Yi

    2014-06-04

    Ag nanowire-based catalytic liquid marbles are fabricated as miniature reactors, which demonstrate highly efficient, support-free and rate-controllable heterogeneous degradation of methylene blue, with catalytic efficiency close to 100%. Our miniature catalytic liquid marbles are essential for reactions involving highly toxic/hazardous or costly reactants, where small volume preliminary reactions are preferred.

  17. Photocatalytic Degradation of Methylene Blue with Side-glowing Optical Fiber Deliverying Visible Light

    Institute of Scientific and Technical Information of China (English)

    储金宇; 仲蕾

    2012-01-01

    The side-glowing optical fibers (SOFs) were chosen as the conducting medium of endogenous light; and 20 mg·L-1 methylene blue was chosen as the target to be degraded. The SOF is made up of quartz core with a silicon cladding, which can emit light through side surface more uniformly and transmit light for longer distance to avoid attenuation of light by liquid medium. The filament lamp was chosen as visible light source. Different reaction conditions, such as the presence of optical fiber or not, the quantity of SOF, light irradiation intensity were tested by measuring the methylene blue degradation of methylene blue. The results show that suitable reaction conditions were 1.167 g·L-1 Ag + /TiO 2 with 7% (by mass) of Ag + doped in TiO 2 , and 500 roots of SOF (30 cm length in solution). The photocatalytic degradation efficiency under 300W lamp irradiation for 8h was about 97%. And the photocatalytic degradation efficiency of methylene blue degradation was proportional to SOF quantity, light irradiation intensity and catalytic dosage within a certain range. Compared with general UV and visible light SOFs could save a huge amount of energy and cost, in the potential applications in dealing with organic pollutants on a large scale.

  18. Citrus pectin derived porous carbons as a superior adsorbent toward removal of methylene blue

    Science.gov (United States)

    Zhang, Wenlin; Zhang, Lian Ying; Zhao, Xi Juan; Zhou, Zhiqin

    2016-11-01

    An adsorbent, citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward removal of methylene blue, was synthesized by a facile zinc chloride activation approach in this study. The materials hold a great potential for treatment of dye wastewater.

  19. Visible light induced photobleaching of methylene blue over melamine-doped TiO2 nanocatalyst

    Science.gov (United States)

    TiO2 doping with N-rich melamine produced a stable, active and visible light sentisized nanocatalyst that showed a remarkable efficiency towards the photobleaching of a model compound – methylene blue (MB) in aqueous solution. The photobleaching followed a mixed reaction order ki...

  20. Study of catalytic reduction and photodegradation of methylene blue by heterogeneous catalyst.

    Science.gov (United States)

    Sohrabnezhad, Sh

    2011-10-15

    The photocatalytic degradation of methylene blue is investigated in aqueous solution containing CoS/nanoAl-MCM-41 photocatalyst under visible light. The catalyst is characterized by X-ray diffraction (XRD), UV-vis diffused reflectance spectra (UV-vis DRS) and transmission electron microscopy (TEM) techniques. The effect of CoS, nanoAl-MCM-41 support and different wt% of CoS over the support on the photocatalytic degradation and influence of parameters such as CoS loading, catalyst amount, pH and initial concentration of methylene blue on degradation are evaluated. Hypsochromic effects (i.e. blue shifts of spectral bands) resulting from N-demethylation of the dimethylamino group in methylene blue occurs in presence of CoS/nanoAl-MCM-41 under ambient condition. Meanwhile, the bleaching of methylene blue MB, by sulfide ion, in an aqueous solution is studied in the presence nanoAl-MCM-41 catalyst. In the presence of sulfide ions, MB is bleached to its colorless leuco (LMB) and MBH(2)(+) forms. In an acidified solution (pHdye to MBH(2)(+) form is observed. Using nanoAl-MCM-41 with encapsulated CoS nanoparticles only causes demethylation of MB in aqueous solution.

  1. Methylene blue adsorption by algal biomass based materials: biosorbents characterization and process behaviour.

    Science.gov (United States)

    Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

    2007-08-17

    Dead algal biomass is a natural material that serves as a basis for developing a new family of sorbent materials potentially suitable for many industrial applications. In this work an algal industrial waste from agar extraction process, algae Gelidium and a composite material obtained by immobilization of the algal waste with polyacrylonitrile (PAN) were physical characterized and used as biosorbents for dyes removal using methylene blue as model. The apparent and real densities and the porosity of biosorbents particles were determined by mercury porosimetry and helium picnometry. The methylene blue adsorption in the liquid phase was the method chosen to calculate the specific surface area of biosorbent particles as it seems to reproduce better the surface area accessible to metal ions in the biosorption process than the N2 adsorption-desorption dry method. The porous texture of the biosorbents particles was also studied. Equilibrium isotherms are well described by the Langmuir equation, giving maximum uptake capacities of 171, 104 and 74 mg g(-1), respectively for algae, algal waste and composite material. Kinetic experiments at different initial methylene blue concentrations were performed to evaluate the equilibrium time and the importance of the driving force to overcome mass transfer resistances. The pseudo-first-order and pseudo-second-order kinetic models adequately describe the kinetic data. The biosorbents used in this work proved to be promising materials for removing methylene blue from aqueous solutions.

  2. Heterogeneous photocatalysis of methylene blue over titanate nanotubes: effect of adsorption.

    Science.gov (United States)

    Xiong, Lin; Sun, Weiling; Yang, Ye; Chen, Cheng; Ni, Jinren

    2011-04-01

    Titanate nanotubes were synthesized with hydrothermal reaction using TiO(2) and NaOH as the precursors and subsequent calcination at 400°C for 2h. The products were characterized with SEM and XRD. Adsorption and photocatalysis of methylene blue over titanate nanotubes and TiO(2) were investigated. The results indicated that titanate nanotubes exhibited a better photocatalytic degradation of methylene blue in a simultaneous adsorption and photodegradation system than that in equilibrium adsorption followed by a photodegradation system, whereas TiO(2) showed no significant differences in photocatalytic activity in the two systems. The methylene blue overall removal efficiency over TNTs in the first system even exceeded that over TiO(2). The different catalytic performances of titanate nanotubes in the two systems were tentatively attributed to different effects of adsorption of methylene blue, i.e., the promoting effect in the former and the inhibition effect in the latter. Decantation experiments showed that the titanate nanotube photocatalyst could be easily separated from the reaction medium by sedimentation. Thus titanate nanotubes with high sedimentation rates and concurrent adsorption represent a new catalyst system with a strong potential for commercial applications.

  3. REMOVAL OF METHYLENE BLUE BY ADSORPTION ONTO RETAMA RAETAM PLANT: KINETICS AND EQUILIBRIUM STUDY

    Directory of Open Access Journals (Sweden)

    Dalila Badis

    2016-12-01

    Full Text Available The feasibility of using medicinal plants species Retama raetam as a low cost and an eco-friendly adsorbent for the adsorption of cationic dye methylene blue from simulated aqueous solution has been investigated. Adsorption kinetics of methylene blue onto Retama raetam plants was studied in a batch system. The effects of pH and contact time were examined. The methylene blue maximum adsorption occurred at pH 8 and the lowest adsorption occurred at pH 2. The apparent equilibrium was reached after 120 min. Optimal experimental conditions were determined. Adsorption modelling parameters for Freundlich and Langmuir isotherms were determined and, based on R2, various error distribution functions were evaluated as well. Adsorption isotherm was best described by non linear Freundlich isotherm model. Thermodynamic studies show that adsorption was spontaneous and exothermic. For determining the best-fit-kinetic adsorption model, the experimental data were analyzed by using pseudo-first-order, pseudo-second-order, pseudo-third-order, Esquivel, and Elovich models. Linear regressive and non-linear regressive method was used to obtain the relative parameters. The statistical functions were estimated to find the suitable method that fit better the experimental data. Both methods were appropriate for obtaining the parameters. The linear pseudo-second-order (type 9 and type 10 models were the best to fit the equilibrium data. The present work showed that plant Retama raetam can be used as a low cost adsorbent for the removal of methylene blue from water.

  4. Comparative pharmacokinetics of oral and intravenous ifosfamide/mesna/methylene blue therapy.

    Science.gov (United States)

    Aeschlimann, C; Küpfer, A; Schefer, H; Cerny, T

    1998-09-01

    Oral treatment with ifosfamide results in dose-limiting encephalopathy. Methylene blue is effective in reversal and prophylaxis of this side effect. In the present study, the pharmacokinetics of ifosfamide after iv and po therapy in combination with prophylactic administration of methylene blue were investigated. Nine patients with metastatic non-small cell lung cancer were treated by a combination of ifosfamide (3 days), sodium 2-mercaptoethane sulfonate (4 days), and etoposide (8 days). Cycles were repeated every 28 days. Ifosfamide was administered orally, with the exception of one of the first two cycles, when it was administered as a short infusion (randomly assigned). The patients received methylene blue in doses of 50 mg po 3 times daily; an initial dose of 50 mg was given the evening before chemotherapy. Urine samples were collected over the entire treatment period, and concentrations of ifosfamide and its major metabolite, 2-chloroethylamine, were measured by gas liquid chromatography. By the same technique, 2- and 3-dechloroethylifosfamide were determined in plasma and urine. Overall alkylating activity in urine was assayed by reaction of the alkylating metabolites with 4-(4'-nitrobenzyl)-pyridine. The chemotherapeutic regimen was well-tolerated by all of the patients studied. There was no evidence of a shift in the metabolic pattern dependent on the route of administration. From the data, we conclude that methylene blue has a neuroprotective effect and that the pharmacokinetics of ifosfamide are not influenced by its comedication.

  5. Graphene oxide functionalized with methylene blue and its performance in singlet oxygen generation

    Energy Technology Data Exchange (ETDEWEB)

    Wojtoniszak, M., E-mail: mwojtoniszak@zut.edu.pl [West Pomeranian University of Technology in Szczecin, Institute of Chemical and Environment Engineering, Pulaskiego 10, 70-322 Szczecin (Poland); Rogińska, D.; Machaliński, B. [Pomeranian Medical University, Department of General Pathology, Powstańców Wlkp. 72, 70-111 Szczecin (Poland); Drozdzik, M. [Pomeranian Medical University, Department of Pharmacology, Powstańców Wlkp. 72, 70-111 Szczecin (Poland); Mijowska, E. [West Pomeranian University of Technology in Szczecin, Institute of Chemical and Environment Engineering, Pulaskiego 10, 70-322 Szczecin (Poland)

    2013-07-15

    Graphical abstract: - Highlights: • Adsorption of methylene blue (MB) on graphene oxide (GO). • Characterization of graphene oxide–methylene blue nanocomposite (MB–GO). • Examination of MB–GO efficiency in singlet oxygen generation (SOG). • MB–GO performs higher SOG efficiency than pristine MB. - Abstract: Due to unique electronic, mechanical, optical and structural properties, graphene has shown promising applications in many fields, including biomedicine. One of them is noninvasive anticancer therapy – photodynamic therapy (PDT), where singlet oxygen (SO), generated under the irradiation of light with appropriate wavelengths, kills cancer cells. In this study, authors report graphene oxide (GO) noncovalent functionalization with methylene blue (MB). MB molecules underwent adsorption on the surface of GO. Detailed characterization of the obtained material was carried out with UV–vis spectroscopy, Raman spectroscopy, FT-IR spectroscopy, and confocal laser scanning microscopy. Furthermore, its performance in singlet oxygen generation (SOG) under irradiation of laser with excitation wavelengths of 785 nm was investigated. Interestingly, GO functionalized with MB (MB–GO) showed enhanced efficiency in singlet oxygen generation compared to pristine MB. The efficiency in SOG was detected by photobleaching of 9,10-anthracenediyl-bis(methylene)dimalonic acid (ABMDMA). These results indicate the material is promising in PDT anticancer therapy and further in vitro and in vivo studies are required.

  6. The Adsorption Efficiency of Chemically Prepared Activated Carbon from Cola Nut Shells by on Methylene Blue

    Directory of Open Access Journals (Sweden)

    Julius Ndi Nsami

    2013-01-01

    Full Text Available The adsorption of methylene blue from aqueous solution onto activated carbon prepared from cola nut shell has been investigated under batch mode. The influence of major parameters governing the efficiency of the process such as, solution pH, sorbent dose, initial concentration, and contact time on the removal process was investigated. The time-dependent experimental studies showed that the adsorption quantity of methylene blue increases with initial concentration and decreasing adsorbent dosage. The equilibrium time of 180 min was observed and maximum adsorption was favoured at pH 3.5. The dye removal using 0.1 g of adsorbent was more than 90%. This dosage (0.1 g was considered as the optimum dosage to remove methylene blue from aqueous solutions. The equilibrium adsorption data were analyzed by the Freundlich, Langmuir adsorption isotherm models. The kinetics of methylene blue solution was discussed by pseudo-first-order, pseudo-second-order, and Elovich models. The adsorption process follows the Elovich rate kinetic model, having a correlation coefficient in the range between 0.9811 and 1.

  7. Adsorption of Methylene Blue and Amaranth on to tamarind pod shells

    Directory of Open Access Journals (Sweden)

    Ahalya Naidu

    2012-08-01

    Full Text Available In the present study, agricultural waste tamarind (Tamarindus indica pod shells were used for the adsorption of dyes like methylene blue and amaranth. The operating variables studied were initial concentration, initial solution pH, adsorbent dosage and contact time. Experimental equilibrium data were fitted to Freundlich and Langmuir isotherms. The kinetics of methylene blue and amaranth onto tamarind pod shells was found to follow a pseudo first order kinetics. The maximum adsorption of amaranth and methylene blue are 65.04 and 60.11 mg/g of the adsorbent respectively.  The fourier transformed infrared spectroscopy reveals that –OH, -COOH, C=O and C-O groups are involved in the adsorption process. The optimum pH for the adsorption of amaranth is 2 and methylene blue, a cationic dye shows maximum adsorption in the pH range 6-12. Characterisation of the tamarind pod shells showed that the relative percentage of protein is very less making it an excellent adsorbent for the removal of dyes from wastewater effluents.

  8. Process for crosslinking methylene-containing aromatic polymers with ionizing radiation

    Science.gov (United States)

    Bell, Vernon L. (Inventor); Havens, Stephen J. (Inventor)

    1990-01-01

    A process for crosslinking aromatic polymers containing radiation-sensitive methylene groups (-CH2-) by exposing the polymers to ionizing radiation thereby causing crosslinking of the polymers through the methylene groups is described. Crosslinked polymers are resistant to most organic solvents such as acetone, alcohols, hydrocarbons, methylene, chloride, chloroform, and other halogenated hydrocarbons, to common fuels and to hydraulic fluids in contrast to readily soluble uncrosslinked polymers. In addition, the degree of crosslinking of the polymers depends upon the percentage of the connecting groups which are methylene which ranges from 5 to 50 pct and preferably from 25 to 50 pct of the connecting groups, and is also controlled by the level of irradiation which ranges from 25 to 1000 Mrads and preferably from 25 to 250 Mrads. The temperature of the reaction conditions ranges from 25 to 200 C and preferably at or slightly above the glass transition temperature of the polymer. The crosslinked polymers are generally more resistant to degradation at elevated temperatures such as greater than 150 C, have a reduced tendency to creep under load, and show no significant embrittlement of parts fabricated from the polymers.

  9. Scientific Basis for Paint Stripping: Elucidated Combinatorial Mechanism of Methylene Chloride and Phenol Based Paint Removers

    Science.gov (United States)

    2014-01-22

    Thermal Analysis ...................................................................................................................... 31 Solution...to use wet organic chemistry, thermal analysis, visible microscopy and spectroscopy and vibrational spectroscopy to understand the mechanism of how...solvates the carbonyl bond to cause dilation . Deuterium NMR confirms this by showing restriction to the tumbling of methylene chloride, likely do to some

  10. Retrograde Instillation of Methylene Blue in the Difficult Diagnosis of BPF

    Directory of Open Access Journals (Sweden)

    F. Ravenna

    2012-01-01

    Full Text Available We report two cases in which we were able to diagnose bronchopleural fistula through retrograde methylene blue instillation during bronchoscopy. In the first case, methylene blue was injected through an abdominal drain, followed by air instillation and detected in the left bronchial tree, demonstrating the presence of a fistula in the lingula’s bronchus. In the second case, methylene blue was injected into a pleural drain, through a breach on a surgical suture and detected in the right bronchial tree, demonstrating the presence of a fistula in the right inferior bronchus. The retrograde instillation of methylene blue, through a drain in the abdomen or the thoracic wall, is a safe, cheap, and practical method that allows the bronchoscopist to identify the presence of a fistula and, more importantly, to identify the exact point on the bronchial tree where a fistula is located. This provides the possibility of sealing the fistula with a variety of devices. It is our opinion that this procedure should be considered a primary method of diagnosis when a bronchopleural fistula is suspected and a drain on the thoracic or abdominal wall is positioned such that effusions are able to drain.

  11. Methylene Blue halves the long-term recurrence rate in acute pilonidal sinus disease

    DEFF Research Database (Denmark)

    Doll, Dietrich; Novotny, Alexander; Rothe, Ronny;

    2008-01-01

    OBJECTIVE: To study the potential benefits of intraoperative methylene blue (MB) use in pilonidal sinus surgery, the correlation between long-term recurrence rate and intraoperative MB use in pilonidal sinus surgery was investigated. BACKGROUND: Explicit investigations of MB effects in sinus...

  12. [Enhanced reductive decoloration of methylene blue by polyacrylic acid modified zero-valent iron nanoparticles].

    Science.gov (United States)

    He, Jing; Wang, Xiang-Yu; Wang, Pei; Liu, Kun-Qian

    2015-03-01

    Nano zerovalent iron ( NZVI) technology has attracted tremendous amount of interests for degrading a number of environmental contaminants found both in surface water and underground water. However, these nanoscale particles are prone to aggregate, which may result in the decrease of its reactivity in liquid phase. Iron nanoparticles (Fe NPs) modified with polyacrylic acid (PAA) has enhanced the dispersion of NZVI and reduced its agglomeration. For the first time, PAA modified NPs (PAA-Fe NPs) were used for degradation of methylene blue in water phase. The PAA-Fe NPs prepared were characterized in terms of TEM, SEM, XRD and specific surface area. The results indicated that, the surface area of PAA-Fe NPs was increased, compared with unmodified pristine zero-valent iron NPs, and PAA-Fe NPs were smoother with smaller particle size. With addition of 0.1 g x L(-1) of PAA, the decolorization efficiency of methylene blue by PAA-Fe NPs was 98.84% in 60 min, which was 27.32% higher than that of pristine Fe NPs. Decolorization efficiencies were also affected by initial pH value, initial concentration of methylene blue, dosage of PAA-Fe NPs, and degradation temperature. Kinetic analyses based on the experimental data illustrated that the decolorization reaction of methylene blue fitted well to the pseudo first-order kinetics model.

  13. Reliability of assessing dye penetration along root canal fillings using methylene blue

    NARCIS (Netherlands)

    Souza, E.M.; Pappen, F.G.; Shemesh, H.; Bonato-Estrela, C.; Bonetti-Filho, I.

    2009-01-01

    Methylene blue (MB) remains the most frequently used tracer for dye penetration tests of endodontic fillings, despite its chemical reactions with different materials. This study checked whether dye penetration displayed by MB is comparable to Rhodamine B (RB). One hundred and seventy-two root canals

  14. The Condensation of Aromatic Aldehydes with Acidic Methylene Compounds in Water

    Institute of Scientific and Technical Information of China (English)

    Da Qing SHI; Jing CHEN; Qi Ya ZHUANG; Xiang Shan WANG; Hong Wen HU

    2003-01-01

    The condensation of aromatic aldehydes with acidic methylene compounds such as malononitrile, methyl cyanoacetate, cyanoacetamide, 5,5-dimethyl-1,3-cyclohexanedione, bartbituric acid and 2-thiobarbituric acid proceeded very efficiently in water in the presence of triethylbenzylammonium chloride (TEBA) and the products were isolated simply by filtration.

  15. [Sensitive determination of Bi3+ by spectrofluorimetry based on graphene oxide-methylene blue system].

    Science.gov (United States)

    Zhai, Qiu-ge; Guo, Peng; Zhou, Lin; Liu, Yan-ming

    2014-08-01

    Graphene oxide was prepared by the modified Hummers method and characterized by field emission scanning electron microscopy. The interaction of graphene with methylene blue was studied by UV absorption, the intensity of two main absorption peaks of methylene blue decreased significantly after the fluorescence was quenched, and the energy transfer didn't occur because the overlap of the absorption spectrum of GO and the emission spectrum of MB is too small. Therefore, the fluorescence quenching of MB and GO was static. When adding a certain amount of Bi3+ in the graphene-methylene blue system, Bi3+ replaces the methylene blue from the graphene-methylene blue complexes because Bi3+ has the smaller volume and is more positively charged. The methylene blue therefore dissociates from the GO-MB complexes, resulting in the recovery of fluorescence of the system. Furthermore, the fluorescence of the system increases with the increase in the amount of Bi3+ due to the enhanced amount of MB in the system. A novel spectrofluorimetric method was therefore developed for the sensitive determination of Bi3+. Some parameters including the concentration of methylene blue, the amount of graphene oxide, the amount of nitric acid and the sequence of reagent adding were optimized to obtain higher sensitivity. The fluorescence of the system was detected at an emission wavelength of 667 nm with excitation at 690 nm. Under the optimized conditions, the concentration of Bi3+ showed good linear relationships with the fluorescence intensity in the range of 0.5-100 micromol x L(-1), with correlation coefficients of r = 0.9955. The limits of detection for Bi3+ was 1.0 x 10(-8) mol x L(-1) (S/N=3). The selectivity of the proposed method was evaluated and the results showed that 1000-fold K+, Ca+, Na+, Mg2+, Cu2+; 100-fold Fe3+, Be2+, SiO2- Al3+, Ni2+, Sb3+, NO3-, Cl-, F-, and 20-fold Pb2+, Hg2+, Cd2+ had negligible interference with the determination of Bi3+. The method has advantages of

  16. Methylene blue induces macroautophagy through 5' adenosine monophosphate-activated protein kinase pathway to protect neurons from serum deprivation.

    Science.gov (United States)

    Xie, Luokun; Li, Wenjun; Winters, Ali; Yuan, Fang; Jin, Kunlin; Yang, Shaohua

    2013-01-01

    Methylene blue has been shown to be neuroprotective in multiple experimental neurodegenerative disease models. However, the mechanisms underlying the neuroprotective effects have not been fully elucidated. Previous studies have shown that macroautophagy has multiple beneficial roles for maintaining normal cellular homeostasis and that induction of macroautophagy after myocardial ischemia is protective. In the present study we demonstrated that methylene blue could protect HT22 hippocampal cell death induced by serum deprivation, companied by induction of macroautophagy. We also found that methylene blue-mediated neuroprotection was abolished by macroautophagy inhibition. Interestingly, 5' adenosine monophosphate-activated protein kinase (AMPK) signaling, but not inhibition of mammalian target of rapamycin signaling, was activated at 12 and 24 h after methylene blue treatment in a dose-dependent manner. Methylene blue-induced macroautophagy was blocked by AMPK inhibitor. Consistent with in vitro data, macroautophagy was induced in the cortex and hippocampus of mouse brains treated with methylene blue. Our findings suggest that methylene blue-induced neuroprotection is mediated, at least in part, by macroautophagy though activation of AMPK signaling.

  17. Fast-response humidity-sensing films based on methylene blue aggregates formed on nanoporous semiconductor films

    Science.gov (United States)

    Ishizaki, Ryota; Katoh, Ryuzi

    2016-05-01

    We prepared fast-response colorimetric humidity-sensing (vapochromic) films based on methylene blue adsorption onto nanoporous semiconductor (TiO2, Al2O3) films. Color changes caused by changes of humidity could be easily identified visually. A characteristic feature of the vapochromic films was their fast response to changes of humidity. We found that the response began to occur within 10 ms. The response was rapid because all the methylene blue molecules attached to the nanoporous semiconductor surface were directly exposed to the environment. We also deduced that the color changes were caused by structural changes of the methylene blue aggregates on the surface.

  18. Performance and organ morphology of broilers fed microbial or antimicrobial additives and raised in batteries or floor pens

    Directory of Open Access Journals (Sweden)

    Pedroso AA

    2003-01-01

    Full Text Available This study was conducted to determine the effect of microbial or antimicrobial additives on the performance and organ morphology of broilers raised in batteries or in floor pens. The effect of microbial additives on the presence of oocysts in the litter was also studied. Experiments 1 and 2 consisted of four treatments (non-supplemented control diet or diet supplemented with avilamycin, bacitracin methylene disalicylate or enramycin and six repetitions in a randomized block design. In Experiment 1, 288 day-old chicks were housed in heated batteries in a environmentally controlled room, 12 chicks per cage; in Experiment 2, 1,200 day-old chicks were housed in a curtain-sided experimental house, with concrete floor and rice hulls as litter material, 50 chicks per pen. Experiments 3 and 4 were carried out similarly to Experiments 1 and 2, respectively, but the treatments consisted of microbial additives (non-supplemented control diet or Bacillus subtilis added to the feed plus Lactobacillus reuteri and Lactobacillus johnsonii added to the water, undefined microflora added to the water or live yeast added to the feed. The antibiotics did not affect the performance of birds raised in batteries, but improved feed conversion, weight gain and live weight when chickens were kept on the floor pens. Microbial additives did not affect bird performance in any environment; however, treatments affected liver weight. Microbial agents increased intestinal weight in floor-raised broilers. No relationship was seen between the use of microbial additives and the presence of oocysts in the litter.

  19. Effect of yeast-derived products and distillers dried grains with solubles (DDGS) on growth performance and local innate immune response of broiler chickens challenged with Clostridium perfringens.

    Science.gov (United States)

    Alizadeh, M; Rogiewicz, A; McMillan, E; Rodriguez-Lecompte, J C; Patterson, R; Slominski, B A

    2016-06-01

    This study evaluated the effect of yeast-derived products on growth performance, gut lesion score, intestinal population of Clostridium perfringens, and local innate immunity of broiler chickens challenged with C. perfringens. One-day-old broiler chickens were randomly assigned to eight dietary treatments providing six replicate pens of 55 birds each per treatment. Dietary treatments consisted of Control diets without and with C. perfringens challenge, and diets containing bacitracin methylene disalicylate (BMD, 55 g/tonne), nucleotides (150 g/tonne), yeast cell wall (YCW, 300 g/tonne), and a commercial product Maxi-Gen Plus (1 kg/tonne) fed to chickens challenged with C. perfringens. Diets containing 10% distillers dried grains with solubles without and with C. perfringens challenge were also used. Birds were orally challenged with C. perfringens (10(8) colony-forming units (cfu)/bird) on day 14. On day 21, intestinal samples were collected for gene expression analysis. Pathogen challenge significantly (P intestinal lesion scores were observed for challenged birds except the BMD-containing diet. Over the entire trial (1-35 days), no difference in growth performance was observed except the BMD diet which improved FCR over the Control, challenged group. Birds receiving nucleotides showed increased expression of toll-like receptors and cytokines interleukin (IL)-4 and IL-18 compared to the Control, challenged group. Expression of macrophage mannose receptor and IL-18 was upregulated in birds receiving YCW. Increased expression of cytokines and receptors involved in innate immunity in broilers receiving nucleotides and YCW suggests the immunomodulatory properties of these products under pathogen challenge conditions.

  20. Homogeneous photosensitized degradation of pharmaceuticals by using red light LED as light source and methylene blue as photosensitizer

    NARCIS (Netherlands)

    Ye, Y.; Bruning, H.; Yntema, D.; Mayer, M.; Rijnaarts, H.

    2017-01-01

    Research on employing advanced oxidation processes (AOPs) for pharmaceuticals removal is gaining interests. However, detrimental effects of background water constituents in complex water matrices are limiting their implementation. In this study, we report red light induced methylene blue photosensit

  1. DEVELOPMENTAL TOXICITY OF COPPER CHLORIDE, METHYLENE CHLORIDE,AND 6-AMINONICOTINAMIDE TO EMBRYOS OF THE GRASS SHRIMPPALAEMONETES PUGIO

    Science.gov (United States)

    Embryos of estuarine grass shrimp Palaemonetes pugio have demonstrated sensitivity to various solvents and petroleum products, indicating utility for evaluating estuarine contamination. Testing was performed to establish concentration-response curves for methylene chloride, cop...

  2. Elaeagnus angustifolia STONE AS A LOW-COST BIOSORBENT PRECURSOR FOR REMOVAL OF METHYLENE BLUE FROM AQUEOUS SOLUTION

    Directory of Open Access Journals (Sweden)

    Murat KILIÇ

    2012-06-01

    Full Text Available In this study, the removal of methylene blue from aqueous solutions by biosorption onto Elaeagnus angustifolia stone has investigated. Optimum biosorption conditions have determined as a function of pH, biosorbent dosage, initial methylene blue concentration, contact time and temperature of the solution for the removal of methylene blue. Langmuir, Freundlich and Dubinin-Radushkevich (D-R isotherm models have used to describe the biosorption isotherm model. The experimental data have fitted to pseudo-first order, pseudo-second order and intraparticle diffusion model to examine the sorption kinetics. The values of ΔG°, ΔH° and ΔS° have calculated by thermodynamic study to determine the nature of biosorption process. Experimental results have shown that Elaeagnus angustifolia stone can be used as an effective and low cost biosorbent precursor for the removal of methylene blue from aqueous solutions.

  3. Removal of methylene blue by tea wastages from the synthesis waste waters

    Institute of Scientific and Technical Information of China (English)

    Masoud Giahi; Roohan Rakhshaee; Mohammad A. Bagherinia

    2011-01-01

    The tea wastages could remove methylene blue (MB) as a cationic dye from waste water corresponding to second-order kinetic model. Thermodynamic studies showed that adsorption equilibrium constant (KL) and maximum adsorption capacities (Qmax) were increased with increasing temperature. The removal efficiency of MB for Co 0.01 mmol/L at optimum conditions was about 85%. The maximum uptake capacity (Qmax) of methylene blue in a batch reactor was 0.328,0.542 and 0.659 mmol/g at 15,25 and 40 °C, respectively. The enthalpy change (△H) and entropy change (AS) were 11.356 kJ/mol and 20.563 J/(mol K), respectively.

  4. METHYLENE BLUE MINERALISATION BY ELECTROCHEMICAL PROCESS MEDIATED BY COBALT CATALYST ON PLATINUM ELECTRODES

    Directory of Open Access Journals (Sweden)

    Ouarda BRAHMIA

    2015-12-01

    Full Text Available In this study, the electrochemical decolorization of the Methylene Blue dye on Platinum electrodes was assessed. Direct oxidation results demonstrate a partial pollutant degradation reaching a maximum of 64 %. However, the addition of a small amount of a redox mediator Co2+/3+ is efficiently able to electrocatalyse the Methylene blue oxidation by shortening significantly the treatment time and enhancing clearly the dye decolorization rate. Nearly complete decolorization was achieved (92 % in 1h 45min. The most striking results achieved within the cyclic voltammetry study demonstrate undoubtedly the pollutant mineralisation. Electrochemical experiments were performed using the spectrophotometric method, which is very convenient, easy and allows monitoring the spectral changes as well as the determination of the dye concentration during the process. The kinetics data show a first-order indirect oxidation kinetics. A mechanism was proposed to explain the different phenomenon during the electrochemical process.

  5. Photocatalytic degradation of methylene blue with Fe doped ZnS nanoparticles.

    Science.gov (United States)

    Chauhan, Ruby; Kumar, Ashavani; Chaudhary, Ram Pal

    2013-09-01

    Fe doped ZnS nanoparticles (Zn1-xFexS; where x=0.00, 0.03, 0.05 and 0.10) were synthesized by a chemical precipitation method. The synthesized products were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, UV-Vis and photoluminescence spectrometer. The X-ray diffraction and transmission electron microscope studies show that the size of crystallites is in the range of 2-5 nm. Photocatalytic activities of ZnS and 3, 5 and 10 mol% Fe doped ZnS were evaluated by decolorization of methylene blue in aqueous solution under ultraviolet and visible light irradiation. It was found that the Fe doped ZnS bleaches methylene blue much faster than the undoped ZnS upon its exposure to the visible light as compared to ultraviolet light. The optimal Fe/Zn ratio was observed to be 3 mol% for photocatalytic applications.

  6. Comparative study of calcium alginate, activated carbon, and their composite beads on methylene blue adsorption.

    Science.gov (United States)

    Hassan, A F; Abdel-Mohsen, A M; Fouda, Moustafa M G

    2014-02-15

    Three adsorbents, calcium alginate beads (AB), sodium hydroxide activated carbon based coconut shells (C), and calcium alginate/activated carbon composite beads (ACB) were prepared. Their textural properties were characterized by N2-adsorption at -196°C and scanning electron microscopy. The porosity, surface area and total pore volume of C>ACB>AB, but AB adsorbent was more acidic function groups more than the other adsorbents. Adsorption experiments were conducted to examine the effects of adsorbent dosage, pH, time, temperature and initial concentration of methylene blue. Methylene blue adsorption on C, AB and ACB was observed at pH>6 to avoid the competition of H(+). The amount of dye adsorbed increases as the adsorbent dosage increase. Adsorption of dye follows pseudo-second order mechanism. Thermodynamic studies show spontaneous and endothermic nature of the overall adsorption process.

  7. Removal of methylene blue dye from wastewater by using supported liquid memberane technology

    Directory of Open Access Journals (Sweden)

    Ashraf Muhammad Waqar

    2016-06-01

    Full Text Available The present work describes the application of Supported Liquid Membrane (SLM technology towards the removal and recovery of a cationic dye (Methylene Blue from aqueous solutions. Natural and non-toxic vegetable oils have been impregnated on microporous polymeric films of polyvinylidene fluoride (PVDF to constitute a liquid membrane. Different parameters affecting the transport, like pH of feed solution, acid concentration in the strip solution, initial dye concentration, oil types and stirring speeds have been investigated. Highest value of flux (1.7 × 10−5 mg/cm2/sec1 for methylene blue dye was achieved with sunflower oil impregnated on the PVDF support, with pH maintained at 12 in the feed solution and 0.3 M hydrochloric acid concentration in the strip solution. It took 6 hours to transport maximum amount of dye under optimum conditions.

  8. Adsorption studies of Methylene blue dye from aqueous solution onto phaseolus aureus biomaterials.

    Directory of Open Access Journals (Sweden)

    D. B. Jirekar

    2014-09-01

    Full Text Available Experimental investigation was carried out by using commercially available husk of green gram (phaseolusaureus seed to removal ofmethylene blue from aqueous medium. Husk of green gram seed was characterized by performing particle size distribution. The effect of contact time, effect of initial concentration of dye, effect of dosage, effect of salt, effect of pH, zero point pH and effect of temperature were studied in batch technique. Adsorption kinetic was verified by pseudo-first-order and pseudo-second-order models. The rate of adsorption of methylene blue followed by pseudo-second-order model for the dye concentration studied in the present case. Adsorption of methylene blue on green gram (phaseolusaureus seed husk is also followed by Langmuir and Freundlich adsorption isotherm.

  9. USE OF NANOSIZED CHROMIUM DOPED TiO2 SUPPORTED ON ZEOLITE FOR METHYLENE BLUE DEGRADATION

    OpenAIRE

    Ameta, Aarti; Bhati, Indu; Ameta, Rakshit; SURESH C. AMETA

    2010-01-01

    The photocatalytic degradation of methylene blue dye under visible light has been investigated using chromium modified titanium dioxide supported on zeolite (Cr-TiO2/zeolite). The photocatalyst was prepared by sol-gel method and characterized by X-ray diffraction and SEM. The rate of photodegradation of dye was monitored spectrophotometrically. The effect of pH, dye concentration, amount of photocatalyst and intensity of light on the rate of photocatalytic reaction was observed. The results s...

  10. PHOTODEGRADATION METHYLENE BLUE HYDROGELS USING ALCOHOL WITH POL IVINÍLICO TiO2 NANOPARTICLES

    OpenAIRE

    Carhuapoma, Wilson; Universidad Nacional de Ingeniería, Lima, Perú; Ramos, Ángel; Universidad Nacional Mayor de San Marcos, Lima, Perú; López, Álcides; Instituto Peruano de Energía Nuclear, Lima, Perú; Santiago, Julio; Universidad Nacional Mayor de San Marcos, Lima, Perú

    2014-01-01

    A composite containing TiO2 nanoparticles immobilized in a polyvinyl alcohol (PVA) matrix, which was partially crosslinked by gamma radiation, was prepared. The colloidal suspension of TiO2 introduced in the polymeric matrix was characterized by UV-VIS, transmission electronic microscopy and X ray diffraction (XDR), whereas the composite PVA-TiO2 was characterized by UV-VIS and XRD. The efficiency of this material in photocatalysis has been evaluated against methylene blue. A fast fotodegrada...

  11. A New Property of Conjugated Polymer PFP: Catalytic Degradation of Methylene Blue Aqueous Solution

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A new property of conjugated polymer poly(furancarbinol-co-phenol)(PFP) was studied.The target copolymer was used as a catalyst after proper heating treatment. And dye methylene blue (MB) could be fully degraded and largely mineralized on PFP, under natural light or even in dark, in a few minutes. Furthermore, the catalytic activity could be preserved after several runs and the catalyst was readily separated. The effect of calcination temperature was also observed.

  12. Photodynamic action of laser radiation and methylene blue on some opportunistic microorganisms of the oral cavity

    Science.gov (United States)

    Ivanov, Krill I.; Titorenko, Vladimir A.; Shoub, Gennady M.; Lepilin, Alexander V.; Ovchinnikov, Ilya S.; Mischenko, Oksana S.; Tuchin, Valery V.

    2000-03-01

    We have studied photodynamic action of He-Ne laser radiation on cultures of Staphylococcus (strain 209 P), Streptococcus anhaemolyticus, and total microflora of dental deposit been sensitized by methylene blue. The concentration of the dye was varied from 0.001% to 0.1%, radiation power density was 100 mW/cm2. Irradiated strain was put into thermostat for 24 hours, then the number of colonies was counted and analyzed.

  13. Methylenebisnicotiflorin: a rare methylene-bridged bisflavonoid glycoside from ripe Pu-er tea.

    Science.gov (United States)

    Tao, Mu-Ke; Xu, Min; Zhang, Han; Chen, Hui; Liu, Chang; Zhu, Hong-Tao; Wang, Dong; Yang, Chong-Ren; Zhang, Ying-Jun

    2016-01-01

    A new methylene-bridged dimeric flavonol glycoside, methylenebisnicotiflorin (1), was isolated from ripe Pu-er tea, along with 10 known flavonoids (2-11) and seven known phenolic compounds (12-18). The structure elucidation was based on spectroscopic analysis. Among them, 1,3-dihydroxyphenyl-2-O-sulfate (13), 2,3,4-trihydroxybenzoic acid (16) and 3,3',4,4'-tetrahydroxybiphenyl (18) are reported from tea plants for the first time.

  14. The Kinetics of the Photochemical Reaction of Methylene Green with Methylamine and Ethylamine

    OpenAIRE

    SAEED, Rehana; UDDIN, Fahim; KHALID, Zahida

    2004-01-01

    The photochemical reduction of methylene green with methylamine and ethylamine in 50% aqueous isopropanol was studied. The photochemical reduction was carried out in a special type of optical processor associated with a deoxygenating system, a temperature controlling unit and a magnetic stirring system. A monochromatic light of 657 nm wavelength was used for irradiation of oxygen free reaction solutions in a double walled reaction cell. The transmitted light was measured and recorde...

  15. Lack of Methylene Blue Staining in Superficial Epithelia as a Possible Marker for Superficial Lateral Spread of Bile Duct Cancer

    Directory of Open Access Journals (Sweden)

    I. Maetani

    1996-01-01

    epithelia. The cancerous epithelia stained significantly less often than either the normal (p = 0.000005 or the metaplastic (p = 0.001 epithelia. Evaluation of methylene blue staining during PTCS revealed that this stain was absorbed by the cholangial epithelia, not superficially stuck to it. The difference in methylene blue staining properties between the cancerous and normal epithelia could be helpful to clarify the boundary of superficial lateral spread of bile duct cancer.

  16. The kinetics of electron transfer reaction of methylene green and titanium trichloride in different solvents

    Science.gov (United States)

    Saeed, Rehana; Nadeem, Syed Muhammad Saqib

    2016-06-01

    The kinetics of the electron transfer reaction of methylene green and titanium trichloride was investigated in different solvents by spectrophotometry at different temperatures. The the reaction rate was determined by monitoring the absorbance as a function of time at λmax 655 nm. The reaction is pseudo-first order, dependent only on the concentration of titanium trichloride at a fixed concentration of methylene green. The effect of an aqueous alcoholic solvent was studied in the acidic range of pH from 4 to 7. It was observed that the reaction rate increased with an increase in polarity of the reaction medium. The the reaction rate was high in acidic conditions and decreased with a further increase in acidity. The increase in temperature increased the rate of the electron transfer reaction of methylene green and titanium trichloride. The activation energy ( E a) was calculated by the Arrhenius relation. The absence of any reaction intermediate was confirmed by spectroscopic and kinetic investigations. A plausible mechanism for the reaction in line with outer-sphere reaction pathway has been proposed. Thermodynamic parameters such as the activation energy ( E a), enthalpy change (Δ H), free energy change (Δ G), and entropy change (Δ S) were also evaluated

  17. Functional elastic hydrogel as recyclable membrane for the adsorption and degradation of methylene blue.

    Science.gov (United States)

    Bao, Song; Wu, Dongbei; Wang, Qigang; Su, Teng

    2014-01-01

    Developing the application of high-strength hydrogels has gained much attention in the fields of medical, pharmacy, and pollutant removal due to their versatility and stimulus-responsive properties. In this presentation, a high-strength freestanding elastic hydrogel membrane was constructed by clay nanosheets, N, N-dimethylacrylamide and 2-acrylamide-2-methylpropanesulfonic acid for adsorption of methylene blue and heavy metal ions. The maximum values of elongation and Young's modulus for 0.5% AMPSNa hydrogel were 1901% and 949.4 kPa, respectively, much higher than those of traditional hydrogels. The adsorptions were confirmed to follow pseudo-second kinetic equation and Langmuir isotherm model fits the data well. The maximum adsorption capacity of hydrogel towards methylene blue was 434.8 mg g(-1). The hydrogel also exhibited higher separation selectivity to Pb(2+) than Cu(2+). The methylene blue adsorbed onto the hydrogel membrane can be photocatalytically degraded by Fenton agent and the hydrogel membrane could be recycled at least five times without obvious loss in mechanical properties. In conclusion, this presentation demonstrates a convenient strategy to prepare tough and elastic clay nanocomposite hydrogel, which can not only be applied as recyclable membrane for the photocatalytic degradation of organic dye, but also for the recovery of valuables.

  18. Functional elastic hydrogel as recyclable membrane for the adsorption and degradation of methylene blue.

    Directory of Open Access Journals (Sweden)

    Song Bao

    Full Text Available Developing the application of high-strength hydrogels has gained much attention in the fields of medical, pharmacy, and pollutant removal due to their versatility and stimulus-responsive properties. In this presentation, a high-strength freestanding elastic hydrogel membrane was constructed by clay nanosheets, N, N-dimethylacrylamide and 2-acrylamide-2-methylpropanesulfonic acid for adsorption of methylene blue and heavy metal ions. The maximum values of elongation and Young's modulus for 0.5% AMPSNa hydrogel were 1901% and 949.4 kPa, respectively, much higher than those of traditional hydrogels. The adsorptions were confirmed to follow pseudo-second kinetic equation and Langmuir isotherm model fits the data well. The maximum adsorption capacity of hydrogel towards methylene blue was 434.8 mg g(-1. The hydrogel also exhibited higher separation selectivity to Pb(2+ than Cu(2+. The methylene blue adsorbed onto the hydrogel membrane can be photocatalytically degraded by Fenton agent and the hydrogel membrane could be recycled at least five times without obvious loss in mechanical properties. In conclusion, this presentation demonstrates a convenient strategy to prepare tough and elastic clay nanocomposite hydrogel, which can not only be applied as recyclable membrane for the photocatalytic degradation of organic dye, but also for the recovery of valuables.

  19. Application of High-frequency Electrosurgical Scalpel and Methylene Blue Staining in Endonasal Dacryocystorhinostomy

    Institute of Scientific and Technical Information of China (English)

    Zhongling Luo; Lixin Zhang; Yueguang Qiu; Xiaofang Luo

    2014-01-01

    Purpose:.To evaluate the application of a high-frequency electrosurgical scalpel and methylene blue staining in the en-donasal dacryocystorhinostomy. Methods:.This retrospective study included 37 patients (43 eyes).undergoing endonasal dacryocystorhinostomy in our hospital between 2011 and 2013 using methylene blue staining of the lacrimal sac and a high-frequency electrosurgical scalpel for cutting nasal mucosa, intraoperative stanch, and fixation of lacrimal sac and nasal mucosal flaps. Surgical efficacy, in-traoperative challenges,.and corresponding handling methods were evaluated and summarized. Results:.Among 43 eyes,.42 were successfully cured (97.7%) and the symptoms in 1 eye were improved (2.3%). Total effi-cacy rate was 100%. All surgeries were successfully performed.. No severe intraoperative complications were observed. Conclusion:.A high-frequency electrosurgical scalpel,.com-bined with methylene blue staining of the lacrimal sac, is effi-cacious for nasal mucosal cutting,.intraoperative stanch,.and fixation of mucosal flap by cauterization,.which significantly alleviates intraoperative complications and enhances surgical success rate..It deserves widespread application in clinical practice. .(Eye Science 2014; 29:25-29).

  20. Synergistic effect of pulsed corona discharges and ozonation on decolourization of methylene blue in water

    CERN Document Server

    Malik, M A; Ghaffar, A; Ahmed, K

    2002-01-01

    The effect of O sub 2 and O sub 3 bubbling on decolourization of methylene blue by pulsed corona discharges in water was studied. The pulsed corona discharges were produced by charging an 80 pF capacitor with a 40 kV DC source, through a 100 M OMEGA resistor, and discharging it into a needle-plate type reactor at 60 Hz through a rotating spark gap switch. A 20 ml sample of 13.25 mg l sup - sup 1 methylene blue in distilled water was decolourized in 120 min. Bubbling O sub 2 at 10 ml min sup - sup 1 through the discharge region reduced the decolourization time to 25 min. Bubbling O sub 2 containing 1500 mu mol O sub 3 l sup - sup 1 at 10 ml min sup - sup 1 reduced the decolourization time to 8 min. The O sub 3 was produced by fractionating input energy between a water treatment reactor and a O sub 3 generator, i.e. no additional energy was consumed for O sub 3 production. Under the same experimental conditions methylene blue solution in tap water was decolourized in >210 min by corona discharge in solution, in...

  1. Impact of methylene blue in addition to norepinephrine on the intestinal microcirculation in experimental septic shock.

    Science.gov (United States)

    Nantais, Jordan; Dumbarton, Tristan C; Farah, Nizam; Maxan, Alexander; Zhou, Juan; Minor, Samuel; Lehmann, Christian

    2014-01-01

    Methylene blue (MB) has been used with some success as a treatment for the vasoplegia of vasopressor-refractory septic shock. The putative mechanism of action of MB is the inhibition of endothelial nitric oxide within the microvasculature and improved responsiveness to endogenous catecholamines (norepinephrine (NE)). However, to date, no study has demonstrated the microcirculatory effect of methylene blue in septic shock. The objective of this randomized, controlled, animal study was to show, in an experimentally-induced, septic shock model in rats, the effects of MB and NE on global hemodynamics and the microcirculation. Mean arterial pressure (MAP) was drastically reduced following bacterial endotoxin (lipopolysaccharide, LPS) administration in animals not receiving vasopressors. Only the combination of NE + MB restored MAP to control levels by the end of the three hour experiment. Intravital microscopy of the microcirculation was performed in the terminal ileum in order to examine functional capillary density in intestinal muscle layers and the mucosa, as well as leukocyte activation in venules (rolling, adhesion to the endothelium). Untreated LPS animals showed a significant increase in leukocyte adhesion and a decrease in capillary perfusion in the intestinal microcirculation. In groups receiving NE or NE+MB, we observed a significant decrease in leukocyte adhesion and improved functional capillary density, indicating that microvasculature function was improved. This study suggests that methylene blue may be able to improve hemodynamics while preserving microvascular function in septic shock.

  2. New α-Methylene-γ-Butyrolactone Derivatives as Potential Fungicidal Agents: Design, Synthesis and Antifungal Activities

    Directory of Open Access Journals (Sweden)

    Yongling Wu

    2016-01-01

    Full Text Available In consideration of the fact that the α-methylene-γ-butyrolactone moiety is a major bio-functional group in the structure of carabrone and possesses some agricultural biological activity, forty-six new ester and six new ether derivatives containing α-methylene-γ-butyrolactone moieties were synthesized, and their fungicidal activities against Colletotrichum lagenarium and Botrytis cinerea were investigated. Most of the synthesized compounds showed moderate to significant fungicidal activity. Among them, halogen atom-containing derivatives showed better activity than others, especially compounds 6a,d which exhibited excellent fungicidal activity against C. lagenarium, with IC50 values of 7.68 and 8.17 μM. The structure-activity relationship (SAR analysis indicated that ester derivatives with electron-withdrawing groups on the benzene ring showed better fungicidal activity than those with electron-donating groups. A quantitative structure-activity relationship (QSAR model (R2 = 0.9824, F = 203.01, S2 = 0.0083 was obtained through the heuristic method. The built model revealed a strong correlation of fungicidal activity against C. lagenarium with the molecular structures of these compounds. These results are expected to prove helpful in the design and exploration of low toxicity and high efficiency α-methylene-γ-butyrolactone-based fungicides.

  3. Carbon and TiO{sub 2} synergistic effect on methylene blue adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Simonetti, Evelyn Alves Nunes, E-mail: evelynalvesnunes@yahoo.com.br; Simone Cividanes, Luciana de; Campos, Tiago Moreira Bastos; Rossi Canuto de Menezes, Beatriz; Brito, Felipe Sales; Thim, Gilmar Patrocínio

    2016-07-01

    Due to its high efficiency, low cost and a simple operation, the adsorption process is an important and widely used technique for industrial wastewater treatment. Recent studies on the removal of artificial dyes by adsorption include a large number of adsorbents, such as: activated carbon, silicates, carbon nanotube, graphene, fibers, titanates and doped titanates. The carbon insertion in the TiO{sub 2} structure promotes a synergistic effect on the adsorbent composite, improving the adsorption and the charge-transfer efficiency rates. However, there are few studies regarding the adsorption capacity of TiO{sub 2}/Carbon composites with the carbon concentration. This study evaluates the effect of carbon (resorcinol/formaldehyde) insertion on TiO{sub 2} structure through the adsorption process. Adsorbents were prepared by varying the carbon weight percentages using the sol-gel method. The physicochemical properties of the catalysts prepared, such as crystallinity, particle size, surface morphology, specific surface area and pore volume were investigated. The kinetic study, adsorption isotherm, pH effect and thermodynamic study were examined in batch experiments using methylene blue as organic molecule. In addition, the effect of carbon phase on the adsorption capacity of TiO{sub 2}-carbon composite was deeply investigated. SEM micrographs showed that TiO{sub 2} phase grows along the carbon phase and FT-IR results showed the presence of Ti−O−C chemical bonding. The experiments indicate that the carbon phase acted as a nucleation agent for the growth of TiO{sub 2} during the sol-gel step, with a TiO{sub 2} structure suitable for blue methylene adsorption, resulting in a material with large surface area and slit-like or wedge-shaped pores. Further experiments will show the best carbon concentration for methylene blue adsorption using a TiO{sub 2} based material. - Highlights: • This article deals with the adsorption of methylene blue onto TiO{sub 2}-Carbon

  4. Effect of Dietary Antimicrobials on Immune Status in Broiler Chickens

    Science.gov (United States)

    Lee, K. W.; Lillehoj, H. S.; Lee, S. H.; Jang, S. I.; Park, M. S.; Bautista, D. A.; Ritter, G. D.; Hong, Y. H.; Siragusa, G. R.; Lillehoj, E. P.

    2012-01-01

    This study evaluated the effects of dietary anticoccidial drugs plus antibiotic growth promoters (AGPs) on parameters of immunity in commercial broiler chickens. Day-old chicks were raised on used litter from a farm with endemic gangrenous dermatitis to simulate natural pathogen exposure and provided with diets containing decoquinate (DECX) or monensin (COBN) as anticoccidials plus bacitracin methylene disalicylate and roxarsone as AGPs. As a negative control, the chickens were fed with a non-supplemented diet. Immune parameters examined were concanavalin A (ConA)-stimulated spleen cell proliferation, intestine intraepithelial lymphocyte (IEL) and spleen cell subpopulations, and cytokine/chemokine mRNA levels in IELs and spleen cells. ConA-induced proliferation was decreased at 14 d post-hatch in DECX-treated chickens, and increased at 25 and 43 d in COBN-treated animals, compared with untreated controls. In DECX-treated birds, increased percentages of MHC2+ and CD4+ IELS were detected at 14 d, but decreased percentages of these cells were seen at 43 d, compared with untreated controls, while increased TCR2+ IELs were evident at the latter time. Dietary COBN was associated with decreased fractions of MHC2+ and CD4+ IELs and reduced percentages of MHC2+, BU1+, and TCR1+ spleen cells compared with controls. The levels of transcripts for interleukin-4 (IL-4), IL-6, IL-17F, IL-13, CXCLi2, interferon-γ (IFN-γ), and transforming growth factorβ4 were elevated in IELs, and those for IL-13, IL-17D, CXCLi2, and IFN-γ were increased in spleen cells, of DECX- and/or COBN-treated chickens compared with untreated controls. By contrast, IL-2 and IL-12 mRNAs in IELs, and IL-4, IL-12, and IL-17F transcripts in spleen cells, were decreased in DECX- and/or COBN-treated chickens compared with controls. These results suggest that DECX or COBN, in combination with bacitracin and roxarsone, modulate the development of the chicken post-hatch immune system. PMID:25049577

  5. A dose-finding study of methylene blue to inhibit nitric oxide actions in the hemodynamics of human septic shock.

    Science.gov (United States)

    Juffermans, Nicole P; Vervloet, Marc G; Daemen-Gubbels, Catharina R G; Binnekade, Jan M; de Jong, Martin; Groeneveld, A B Johan

    2010-05-15

    Methylene blue increases blood pressure and myocardial function in septic shock mainly by inhibiting nitric oxide (NO) actions. However, a dose-dependency of methylene blue has not been established. Therefore, the compound is currently used as rescue treatment only. To evaluate dose-dependency, a prospective, randomized, double blind, single centre study was performed in 15 consecutive, mechanically ventilated patients with septic shock admitted to the intensive care unit, in whom methylene blue was infused at 1 mg/kg (n=4), 3 mg/kg (n=6) or 7 mg/kg (n=5) over 20 min. Hemodynamic parameters were measured before and after the infusion. Gastric tonometry was performed. Methylene blue treatment increased heart rate, cardiac index, mean arterial, pulmonary artery, pulmonary artery occlusion and central venous pressures, systemic vascular resistance, ventricular stroke work indices and O(2) delivery and uptake, and decreased lactate levels. Methylene blue had a dose-dependent effect on cardiac index, mean arterial, mean pulmonary artery and pulmonary artery occlusion pressures, left ventricular function, O(2) delivery and consumption and lactate levels. The drug dose-dependently increased the gastric-arterial blood PCO(2) gap. The data suggest that in human septic shock, methylene blue increases mean arterial blood pressure by an increase in cardiac index and systemic vascular resistance. The rise in cardiac index is caused by an increase in left ventricular filling and function, increasing tissue oxygenation, even at a dose of 1mg/kg. High doses of methylene blue may compromise splanchnic perfusion, even though further enhancing global hemodynamics, and should therefore, be avoided in future studies.

  6. 40 CFR 721.8485 - 2-Propenoic acid, 2-methyl-, (octahydro-4,7-methano-1H- indene-5-diyl)bis(methylene) ester.

    Science.gov (United States)

    2010-07-01

    ...-, (octahydro-4,7-methano-1H- indene-5-diyl)bis(methylene) ester. 721.8485 Section 721.8485 Protection of...-methyl-, (octahydro-4,7-methano-1H- indene-5-diyl)bis(methylene) ester. (a) Chemical substance and...-, (octahydro-4,7-methano- 1H- indene-5-diyl)bis(methylene) ester (PMN P-99-1075; CAS No. 43048-08-4) is...

  7. Photography - Determination of thiosulphate and other residual chemicals in processed photographic films, plates and papers - Methylene blue photometric method and silver sulphide densitometric method

    CERN Document Server

    International Organization for Standardization. Geneva

    1977-01-01

    Photography - Determination of thiosulphate and other residual chemicals in processed photographic films, plates and papers - Methylene blue photometric method and silver sulphide densitometric method

  8. Adsorption of Methylene Blue from Aqueous Solution onto a Low-Cost Natural Jordanian Tripoli

    Directory of Open Access Journals (Sweden)

    Atef S. ALzaydien

    2009-01-01

    Full Text Available Background: Dyes and pigments are widely used, mostly in the textiles, paper, plastics, leather, food and cosmetic industry to color products. The release of colored wastewater from these industries may present an eco-toxic hazard. Various techniques like precipitation, ion exchange, chemical oxidation, and adsorption have been used for the removal of toxic pollutant from, wastewater. Methylene blue (MB is selected as a model compound for evaluating the potential of tripoli to remove dye from wastewaters. Objective: In this study, Jordanian low- cost locally available tripoli was studied for its potential use as an adsorbent for removal of a cationic dye (methylene blue,MB from aqueous solution. Factors affecting adsorption, such as , initial dye concentration, pH, contact time , adsorbent dose and temperature, were evaluated. The equilibrium of adsorption was modelled by using the Langmuir , Freundlich, Temkin and Dubinin-Radushkevich isotherm models, the kinetic parameters and intraparticle diffusion were also then determined for the methylene blue-tripoli system. Methodology: The raw tripoli samples were kindly supplied by the Authority of Natural Resources (Jordan, Amman. X-ray diffraction spectroscopy (XRD analysis was carried out with PANalytical X-ray, Philips Analytical. Fourier transform infrared spectrophotometry (FT-IR analysis was conducted. The cation exchange capacity (CEC of tripoli was estimated using The copper bis-ethylenediamine complex method. The specific surface area of tripoli was estimated using Sears’ method by agitating 1.5 g of the tripoli sample in 100 ml of diluted hydrochloric acid of a pH = 3. Adsorption equilibrium studies were carried out by adding 0.5 g of tripoli in a series of 250mL flasks containing 100mL of MB solution of different dye concentrations at four different temperatures (20, 30, and 50 ◦C. The experiments of adsorption kinetics were carried out in stirred batch mode. For each experiment, 0.1 L

  9. ANALYSIS OF VAPORS FROM METHYLENE CHLORIDE EXTRACTS OF NUCLEAR GRADE HEPA FILTER FIBERGLASS SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    FRYE JM; ANASTOS HL; GUTIERREZ FC

    2012-06-07

    While several organic compounds were detected in the vapor samples used in the reenactment of the preparation of mounts from the extracts of nuclear grade high-efficiency particulate air filter fiberglass samples, the most significant species present in the samples were methylene chloride, phenol, phenol-d6, and 2-fluorophenol. These species were all known to be present in the extracts, but were expected to have evaporated during the preparation of the mounts, as the mounts appeared to be dry before any vapor was collected. These species were present at the following percentages of their respective occupational exposure limits: methylene chloride, 2%; phenol, 0.4%; and phenol-d6, 0.6%. However, there is no established limit for 2-fluorophenol. Several other compounds were detected at low levels for which, as in the case of 2-fluorophenol, there are no established permissible exposure limits. These compounds include 2-chlorophenol; N-nitroso-1-propanamine; 2-fluoro-1,1{prime}-biphenyl; 1,2-dihydroacenaphthylene; 2,5-cyclohexadiene-1,4-dione,2,6-bis(1,1-dimethylethyl); trimethyl oxirane; n-propylpropanamine; 2-(Propylamino)ethanol; 4-methoxy-1-butene; 6-methyl-5-hepten-2-one; and 3,4-dimethylpyridine. Some of these were among those added as surrogates or spike standards as part ofthe Advanced Technologies and Laboratories International, Inc. preparation ofthe extract of the HEPA filter media and are indicated as such in the data tables in Section 2, Results; other compounds found were not previously known to be present. The main inorganic species detected (sulfate, sodium, and sulfur) are also consistent with species added in the preparation of the methylene chloride extract of the high-efficiency particulate air sample.

  10. Synthesis and characterization of magnetic palygorskite nanoparticles and their application on methylene blue remotion from water

    Energy Technology Data Exchange (ETDEWEB)

    Middea, Antonieta, E-mail: amiddea@cetem.gov.br [Centre for Mineral Technology (CETEM), Av. Pedro Calmon, 900, Cidade Universitária, Rio de Janeiro 21941908 (Brazil); Federal University of Rio de Janeiro, Institute of Macromolecules, Av. Horácio Macedo, 2030, Cidade Universitária, Rio de Janeiro 21941598 (Brazil); Spinelli, Luciana S., E-mail: spinelli@ima.ufrj.br [Federal University of Rio de Janeiro, Institute of Macromolecules, Av. Horácio Macedo, 2030, Cidade Universitária, Rio de Janeiro 21941598 (Brazil); Souza, Fernando G. [Federal University of Rio de Janeiro, Institute of Macromolecules, Av. Horácio Macedo, 2030, Cidade Universitária, Rio de Janeiro 21941598 (Brazil); Neumann, Reiner; Gomes, Otavio da F.M. [Centre for Mineral Technology (CETEM), Av. Pedro Calmon, 900, Cidade Universitária, Rio de Janeiro 21941908 (Brazil); Federal University of Rio de Janeiro, National Museum of Brazil, Postgraduate Program in Geosciences, Av. Quinta da Boa Vista, S/N Bairro Imperial de São Cristóvão, Rio de Janeiro 20940040 (Brazil); Fernandes, Thais L.A.P.; Lima, Luiz C. de [Centre for Mineral Technology (CETEM), Av. Pedro Calmon, 900, Cidade Universitária, Rio de Janeiro 21941908 (Brazil); Barthem, Vitoria M.T.S. [Federal University of Rio de Janeiro, Physics Institute, Av. Athos da Silveira Ramos, 149, Cidade Universitária, Rio de Janeiro 21941972 (Brazil); Carvalho, Fernanda V. de [Centre for Mineral Technology (CETEM), Av. Pedro Calmon, 900, Cidade Universitária, Rio de Janeiro 21941908 (Brazil)

    2015-08-15

    Highlights: • Nanopalygorskites’ surface modification was confirmed by characterization. • The magnetism of nanoparticles was characterized by different techniques. • Methylene blue was easily removed using the magnetic nanopalygorskites. - Abstract: Recently there has been considerable interest in magnetic sorbents materials, which is added excellent capabilities such as sorption and magnetic response to an applied field. Accordingly, palygorskite nanoparticles were covered by magnetite using a co-precipitation technique and characterized by: X-ray fluorescence (XRF), X-ray diffraction (XRD), surface analysing and scanning electron microscopy (SEM) with element analysis and mapping, particle size, pore surface area (BET), density, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and zeta potential. Additionally, magnetic properties were studied by SQUID magnetometer, magnetic force microscopy (MFM) and also using a simple experimental setup. Magnetic nanoparticles produced had average diameters in a nanometric range. The amount of iron present in the nanoparticles increased by six times after the magnetization and a superparamagnetic behavior was exhibited with high saturation magnetization, from 4.0 × 10{sup −4} Am{sup 2}/kg to about 20 Am{sup 2}/kg. A weight loss was also observed around 277 °C–339 °C by TGA, indicating a structural change from magnetite to maghemite, which confirms the magnetization of palygorskite. Batch adsorption experiments were carried out for the removal of methylene blue cationic dye from aqueous solution using pure and covered by magnetite palygorskite nanoparticles as adsorbents. Furthermore, about 90% of methylene blue was removed within 3 min using magnetized palygorskite.

  11. Gold nanoparticles enhance methylene blue-induced photodynamic therapy: a novel therapeutic approach to inhibit Candida albicans biofilm.

    Science.gov (United States)

    Khan, Shakir; Alam, Fahad; Azam, Ameer; Khan, Asad U

    2012-01-01

    This article explores the novel gold nanoparticle-enhanced photodynamic therapy of methylene blue against recalcitrant pathogenic Candida albicans biofilm. Physiochemical (X-ray diffraction, ultraviolet-visible absorption, photon cross-correlation, FTIR, and fluorescence spectroscopy) and electron microscopy techniques were used to characterize gold nanoparticles as well as gold nanoparticle-methylene blue conjugate. A 38.2-J/cm(2) energy density of 660-nm diode laser was applied for activation of gold nanoparticle-methylene blue conjugate and methylene blue against C. albicans biofilm and cells. Antibiofilm assays, confocal laser scanning, and electron microscopy were used to investigate the effects of the conjugate. Physical characteristics of the gold nanoparticles (21 ± 2.5 nm and 0.2 mg/mL) and methylene blue (20 μg/mL) conjugation were confirmed by physicochemical and electron microscopy techniques. Antibiofilm assays and microscopic studies showed significant reduction of biofilm and adverse effect against Candida cells in the presence of conjugate. Fluorescence spectroscopic study confirmed type I photo toxicity against biofilm. Gold nanoparticle conjugate-mediated photodynamic therapy may be used against nosocomially acquired refractory Candida albicans biofilm.

  12. Methylene blue does not reverse existing neurofibrillary tangle pathology in the rTg4510 mouse model of tauopathy.

    Science.gov (United States)

    Spires-Jones, Tara L; Friedman, Taylor; Pitstick, Rose; Polydoro, Manuela; Roe, Allyson; Carlson, George A; Hyman, Bradley T

    2014-03-06

    Alzheimer's disease is characterized pathologically by aggregation of amyloid beta into senile plaques and aggregation of pathologically modified tau into neurofibrillary tangles. While changes in amyloid processing are strongly implicated in disease initiation, the recent failure of amyloid-based therapies has highlighted the importance of tau as a therapeutic target. "Tangle busting" compounds including methylene blue and analogous molecules are currently being evaluated as therapeutics in Alzheimer's disease. Previous studies indicated that methylene blue can reverse tau aggregation in vitro after 10 min, and subsequent studies suggested that high levels of drug reduce tau protein levels (assessed biochemically) in vivo. Here, we tested whether methylene blue could remove established neurofibrillary tangles in the rTg4510 model of tauopathy, which develops robust tangle pathology. We find that 6 weeks of methylene blue dosing in the water from 16 months to 17.5 months of age decreases soluble tau but does not remove sarkosyl insoluble tau, or histologically defined PHF1 or Gallyas positive tangle pathology. These data indicate that methylene blue treatment will likely not rapidly reverse existing tangle pathology.

  13. Pyrolysis Synthesized g-C3N4 for Photocatalytic Degradation of Methylene Blue

    Directory of Open Access Journals (Sweden)

    Gang Xin

    2013-01-01

    Full Text Available Graphitic carbon nitride (g-C3N4 was synthesized at 520°C by the pyrolysis of cyanamide, dicyandiamide, and melamine. The samples were characterized by X–ray diffraction (XRD, UV-visible diffuse reflectance spectra, Fourier transform infrared spectroscopy (FT-IR, and elemental analyzer. The photocatalytic activity of g-C3N4 was evaluated by the photodegrading experiments of methylene blue (MB. The results indicated that g-C3N4. A photocatalytic mechanism presumed the MB photodegradation over the C3N4 photocatalyst is attributed to photogenerated electron impelled multistep reduction of O2.

  14. Pyrite-enhanced methylene blue degradation in non-thermal plasma water treatment reactor.

    Science.gov (United States)

    Benetoli, Luís Otávio de Brito; Cadorin, Bruno Mena; Baldissarelli, Vanessa Zanon; Geremias, Reginaldo; de Souza, Ivan Gonçalvez; Debacher, Nito Angelo

    2012-10-30

    In this study, methylene blue (MB) removal from an aqueous phase by electrical discharge non-thermal plasma (NTP) over water was investigated using three different feed gases: N(2), Ar, and O(2). The results showed that the dye removal rate was not strongly dependent on the feed gas when the electrical current was kept the same for all gases. The hydrogen peroxide generation in the water varied according to the feed gas (N(2)degradation occurs via high energy electron impact as well as successive hydroxylation in the benzene rings of the dye molecules.

  15. Catalytic degradation of methylene blue by Fenton like system:model to the environmental reaction

    Institute of Scientific and Technical Information of China (English)

    Sanjay R. Thakare

    2004-01-01

    To develop more efficient chemical methods for the demineralization of organic pollutants from waterbodies, which one was also mimic to the nature, a degradation of methylene blue by Fe( Ⅲ ) and H2O2 in theabsence of light instead of Fe( Ⅱ ) and H2O2 was studied. Results showed that use of Fe ( Ⅲ ) is more promisingthan Fe( Ⅱ ). The present study reflects that Fenton reaction is more efficient, in the presence of a small amount ofsalicylic acid is added which is a one of the priority pollutant.

  16. Hybrid TiO2-C composites for the photodegradation of methylene blue under visible light

    OpenAIRE

    Matos, Juan

    2013-01-01

    [EN] Photodegradation of methylene blue (MB) on TiO2 in presence of activated carbons (AC) was studied. Two different lamps were employed and results were compared against those obtained on a commercial TiO2. Apparent first order rate constant for the degradation of MB was higher in presence of any AC in comparison of TiO2 alone but much higher under visible light irradiation. It can be concluded that TiO2 enhances its photoactivity by a factor up to 8.7 in the degr...

  17. Antitumor action of methylene blue%美蓝的抗肿瘤作用

    Institute of Scientific and Technical Information of China (English)

    许启泰; 杜钢军; 陈百泉

    2002-01-01

    @@ 美蓝(Methylene blue,MB)原为解毒药物,近年发现有抗肿瘤作用,临床报道将其在肿瘤部位直接介入治疗实体及腹水肿瘤[1~3].为确定美蓝的抗癌范围及为临床应用提供实验依据,我们对美蓝的抗肿瘤作用作了以下研究.

  18. Visible light photocatalytic decoloration of methylene blue on novel N-doped TiO2

    Institute of Scientific and Technical Information of China (English)

    WANG Yan; ZHANG JiWei; JIN ZhenSheng; WU ZhiShen; ZHANG ShunLi

    2007-01-01

    Novel N-doped TiO2 (denoted as N-NTA600) was prepared by treating nanotube titanic acid (NTA) in NH3 flow. Its visible light photocatalytic activity, evaluated by decoloration reaction of methylene blue, is higher than that of N-P25(600) prepared by treatment of P25-TiO2 in the same condition. It is suggested that the origin of visible-light photocatalytic activity is single-electron-trapped oxygen vacancy (Vo·) modified by chemisorbed NO.

  19. Highly selective palladium–benzothiazole carbene-catalyzed allylation of active methylene compounds under neutral conditions

    Directory of Open Access Journals (Sweden)

    Antonio Monopoli

    2015-06-01

    Full Text Available The Pd–benzothiazol-2-ylidene complex I was found to be a chemoselective catalyst for the Tsuji–Trost allylation of active methylene compounds carried out under neutral conditions and using carbonates as allylating agents. The proposed protocol consists in a simplified procedure adopting an in situ prepared catalyst from Pd2dba3 and 3-methylbenzothiazolium salt V as precursors. A comparison of the performance of benzothiazole carbene with phosphanes and an analogous imidazolium carbene ligand is also proposed.

  20. Improved detection of rhamnolipid production using agar plates containing methylene blue and cetyl trimethylammonium bromide.

    Science.gov (United States)

    Pinzon, Neissa M; Ju, Lu-Kwang

    2009-10-01

    Rhamnolipids, produced predominantly by Pseudomonas aeruginosa, are biosurfactants with important applications. For efficient culture screening according to rhamnolipid productivity, the method using agar plates containing methylene blue (MB) and cetyl trimethylammonium bromide (CTAB) was re-examined. An alternative set-up using a fixed underneath light source and image analysis software improved the detection of the circles formed due to complexation between anionic rhamnolipids and cationic MB/CTAB. The roles and effects of MB and CTAB concentrations and pH on the complexation phenomena are reported.

  1. Congenital Methemoglobinemia Type II-Clinical Improvement with Short-Term Methylene Blue Treatment.

    Science.gov (United States)

    Cooper, Monica S; Randall, Melinda; Rowell, Margaret; Charlton, Margaret; Greenway, Anthea; Barnes, Chris

    2016-03-01

    We report a case of prophylactic management with methylene blue (MB) in an almost 4-year-old male with congenital methemoglobinemia type II. He has a CYB5R3 compound heterozygote mutation, causing a cytochrome-b(5) reductase deficiency. Since the MB treatment regimen has commenced, his methemoglobin level has been significantly lower. He has shown modest behavioral improvements (as assessed on the Achenbach behavior report scales). There have been no iatrogenic side effects. These findings are encouraging for symptomatic improvement with regular prophylactic MB treatment but represent a single case report, which must be interpreted with caution.

  2. Utilization of zeolites synthesized from coal ash for methylene blue removal from water

    Directory of Open Access Journals (Sweden)

    Denise Alves Fungaro

    2008-12-01

    Full Text Available The adsorption of methylene blue from aqueous solution was carried out using zeolites synthesized from coal ash as low-cost adsorbents. The coal ash sample was converted to zeolites by hydrothermal treatment using different synthesis parameters. The materials were characterized by physical-chemical analysis, XRD and SEM studies. The adsorption isotherms can be fitted by Freundlich model. The values of the adsorption capacity of adsorbents were similar for adsorbents. Kinetic studies indicate that the adsorption follows pseudo-second-order kinetic model.

  3. Pyrolysis Synthesized g-C3N4 for Photocatalytic Degradation of Methylene Blue

    OpenAIRE

    2013-01-01

    Graphitic carbon nitride (g-C3N4) was synthesized at 520°C by the pyrolysis of cyanamide, dicyandiamide, and melamine. The samples were characterized by X–ray diffraction (XRD), UV-visible diffuse reflectance spectra, Fourier transform infrared spectroscopy (FT-IR), and elemental analyzer. The photocatalytic activity of g-C3N4 was evaluated by the photodegrading experiments of methylene blue (MB). The results indicated that g-C3N4. A photocatalytic mechanism presumed the MB photodegradation o...

  4. High-efficiency photocatalytic degradation of methylene blue using electrospun ZnO nanofibers as catalyst.

    Science.gov (United States)

    Du, P F; Song, L X; Xiong, J; Xi, Z Q; Chen, J J; Gao, L H; Wang, N Y

    2011-09-01

    In this work, ZnO nanofibers (ZNFs) were successfully prepared via a simple electrospinning technique using polyvinylpyrrolidone (PVP) and zinc acetate dihydrate (Zn(CH3COO)2 2H2O) as precursors. The obtained ZNFs have an average diameter of ca. 95 nm and are composed of crystalline wurtzite phase. Methylene blue (MB) dye was used to investigate the photocatalytic performance of pure ZNFs. The study confirms that ZNFs have favorable catalytic activity, and the best degradation efficiency of MB can exceed 90% under UV light irradiation for 3 hours. In addition, we propose a possible photodegradation mechanism.

  5. Decolorization of Methylene Blue with TiO2 Sol via UV Irradiation Photocatalytic Degradation

    OpenAIRE

    2010-01-01

    TiO2 sol was prepared for the degradation of methylene blue (MB) solution under ultraviolet (UV) irradiation. The absorption spectra of MB indicated that the maximum wavelength, 663 nm, almost kept the same. The performance of 92.3% for color removal was reached after 160 min. The particle size of TiO2 sol was about 22.5 nm. X-ray diffraction showed that TiO2 consisted of a single anatase phase. The small size and anatase phase probably resulted in high photocatalytic activity of TiO2 sol. Th...

  6. Adsorption Capability of Cationic Dyes (Methylene Blue and Crystal Violet) onto Poly-γ-glutamic Acid.

    Science.gov (United States)

    Ogata, Fumihiko; Nagai, Noriaki; Kawasaki, Naohito

    2017-01-01

    In this study, the adsorption capability of cationic dyes, which were methylene blue and crystal violet, by poly-γ-glutamic acid (PGA) in a single or binary solution system was investigated. The effect of the molecular weight of PGA, initial dye concentration, solution pH, and temperature on the adsorption of dyes was evaluated. The adsorption mechanism of dyes onto PGA was the interaction between -COOH group on the PGA surface and the polarity groups of dyes. These results indicated that PGA is useful for removal of dyes and cationic organic compounds from a single or binary solution system.

  7. Spinal meningeal uptake of technetium-99m methylene diphosphonate in meningeal seeding by malignant lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Siegal, T.; Or, R.; Matzner, Y.; Samuels, L.D.

    1980-12-01

    Definite diagnosis of meningeal seeding by systemic cancer relies on the presence of malignant cells in the cerebrospinal fluid (CSF). In the absence of such cells in the CSF, only two other tests strongly suggest the diagnosis - a CT scan and a myelogram. This paper reports a case in which the diagnosis was strongly suggested by an unusual uptake of Tc-99m methylene diphosphonate by the leptomeninges during a skeletal scan and later established by the presence of malignant cells in the CSF. The radionuclide scan may be an additional diagnostic test in some cases with meningeal seeding by systemic cancer.

  8. Role of methylene spacer in the excitation energy transfer in europium 1- and 2- naphthylcarboxylates

    Energy Technology Data Exchange (ETDEWEB)

    Zhuravlev, K. [V.A. Kotelnikov Institute of Radioengineering and Electronics of RAS, 1 Vvedenskii sq., Fryazino Moscow reg. 141190 (Russian Federation); Tsaryuk, V., E-mail: vit225@ire216.msk.s [V.A. Kotelnikov Institute of Radioengineering and Electronics of RAS, 1 Vvedenskii sq., Fryazino Moscow reg. 141190 (Russian Federation); Kudryashova, V.; Pekareva, I. [V.A. Kotelnikov Institute of Radioengineering and Electronics of RAS, 1 Vvedenskii sq., Fryazino Moscow reg. 141190 (Russian Federation); Sokolnicki, J. [Faculty of Chemistry, University of WrocLaw, 14 F. Joliot-Curie str., WrocLaw 50-383 (Poland); Yakovlev, Yu. [V.A. Kotelnikov Institute of Radioengineering and Electronics of RAS, 1 Vvedenskii sq., Fryazino Moscow reg. 141190 (Russian Federation)

    2010-08-15

    A series of compounds Ln(RCOO){sub 3}.Phen (Ln=Eu, Gd, Tb; RCOO{sup -}-1- and 2-naphthoate, 1- and 2-naphthylacetate, 1- and 2-naphthoxyacetate anions, Phen-1,10-phenanthroline) was investigated by methods of optical spectroscopy. Compounds of composition Ln(RCOO){sub 3}.nH{sub 2}O with the same carboxylate ligands are also considered. Results of studies of the effects of methylene spacer decoupling the {pi}-{pi}- or p-{pi}-conjugation in the naphthylcarboxylate ligand on the structure of Eu{sup 3+} coordination centre, on the lifetime of {sup 5}D{sub 0} (Eu{sup 3+}) state, and on processes of the excitation energy transfer to Eu{sup 3+} or Tb{sup 3+} ions are presented. Introduction of the methylene bridge in the ligand weakens the influence of the steric hindrances in forming of a crystal lattice and results in lowering the distortion of the Eu{sup 3+} luminescence centre, and in elongation of the observed {sup 5}D{sub 0} lifetime {tau}{sub obs}. The latter is caused by decrease in contribution of the radiative processes rate 1/{tau}{sub r}. This is confirmed by the correlation between the lifetimes {tau}{sub obs} and the quantities '{tau}{sub r}.const' inversely proportional to the total integral intensities of Eu(RCOO){sub 3}.Phen luminescence spectra. The methylene spacer performs a role of regulator of sensitization of the Ln{sup 3+} luminescence efficiency by means of an influence on mutual location of lowest triplet states of the ligands, the ligand-metal charge transfer (LMCT) states, and the emitting states of Ln{sup 3+} ions. The lowest triplet state in lanthanide naphthylcarboxylate adducts with Phen is related to carboxylate anion. A presence of the methylene spacer in naphthylcarboxylate ligand increases the triplet state energy. At the same time, the energy of 'carboxylic group-Eu{sup 3+} ion' charge transfer states falls, which can promote the degradation of excitation energy. In naphthylcarboxylates investigated a range of the

  9. Hybrid TiO2-C composites for the photodegradation of methylene blue under visible light

    Directory of Open Access Journals (Sweden)

    J. Matos

    2013-01-01

    Full Text Available Photodegradation of methylene blue (MB on TiO2 in presence of activated carbons (AC was studied. Two different lamps were employed and results were compared against those obtained on a commercial TiO2. Apparent first order rate constant for the degradation of MB was higher in presence of any AC in comparison of TiO2 alone but much higher under visible light irradiation. It can be concluded that TiO2 enhances its photoactivity by a factor up to 8.7 in the degradation of MB in presence of AC and this increase was associated with the surface properties of AC.

  10. (99m)Tc-methylene diphosphonate bone scintigraphy findings in posttransplant distal limb syndrome.

    Science.gov (United States)

    Derlin, Thorsten; Busch, Jasmin D; Bannas, Peter

    2014-07-01

    We report a case of posttransplant distal limb syndrome (PTDLS) representing a rare complication in kidney transplant recipients characterized by a pain syndrome of the distal extremities. A 68-year-old man with a history of kidney transplantation presented with symmetrical and incapacitating pain in the feet and knees and underwent whole-body Tc-methylene diphosphonate (MDP) scintigraphy for further evaluation. Planar scintigraphy demonstrated marked tracer uptake in the distal femoral and tibial epiphyses, and magnetic resonance imaging showed corresponding osteoedema. Tc-MDP scintigraphy is a valuable tool for evaluation of the etiology of musculoskeletal pain and may demonstrate typical findings in case of PTDLS.

  11. Primary neuroblastoma uptake of /sub 99m/technetium methylene diphosphonate

    Energy Technology Data Exchange (ETDEWEB)

    Smith, F.W.; Gilday, D.L.; Ash, J.M.; Reid, R.H.

    1980-11-01

    Forty patients, ages three days to 12 years, with neuroblastomas had bone scans with /sub 99m/technetium methylene diphosphonate (/sub 99m/Tc-MDP) as part of their pretreatment examination. Twenty-four (60%) had primary tumor uptake and 16 (40%) did not. No difference was seen between the two groups in the incidence of tumor calcification or necrosis. No relationship between the level of urinary vanillylmandelic acid (VMA) and the presence of primary tumor uptake of /sub 99m/Tc-MDP was found. The possible causes for the localization of /sub 99m/Tc-MDP are discussed.

  12. Photocatalytic degradation of methylene blue dye under visible light over Cr doped strontium titanate (SrTiO3) nanoparticles.

    Science.gov (United States)

    Qazi, Inamur Rahman; Lee, Woo-Jin; Lee, Hyun-Cheol; Hassan, Mallick Shamshi; Yang, O-Bong

    2010-05-01

    Strontium titanate (SrTiO3) and chromium doped SrTiO3 (Cr/SrTiO3) were prepared by modified sol-gel method with the citric acid as a chelating agent in the ethylene glycol solution for the effective photodegradation of methylene blue dye under visible light irradiation. The synthesized doped and un-doped SrTiO3 nanoparticles were structurally characterized and their photoresponse performances for the efficient degradation of methylene blue dye have been demonstrated. After introducing the Cr on SrTiO3, UV-Vis absorption was appeared the red-shift at 566 nm from 392 nm as compare with bare SrTiO3. The photocatalytic degradation activity of Cr/SrTiO3 was significantly improved to 60% degradation of methylene blue in 3 h under visible light, which is approximately 5 times higher than that of the bare SrTiO3.

  13. DNA-binding Studies of Daunorubicin in the Presence of Methylene Blue by Spectroscopy and Voltammetry Techniques

    Institute of Scientific and Technical Information of China (English)

    HAJIAN Reza; SHAMS Nafiseh; PARVIN Afsaneh

    2009-01-01

    The interaction of daunorubicin with calf thymus DNA has been investigated with the use of methylene blue dye as a spectral probe by the application of UV-Vis spectrophotometry, spectrofluorometry and voltammetry. The voltammetric behavior of daunorubicin has been investigated at a glassy carbon electrode using cyclic and differen-tial pulse voitammetry. Both UV-vis spectrophotometry and cyclic voltammetry studies confirmed the intercalation reaction. The results showed that both daunorubicin and methylene blue molecules could intercalate into the double helix of DNA. The apparent binding constant of daunorubicin with DNA has been found to be 7.8 × 104 L˙mol-1.The fluorescence signal of daunorubicin and methylene blue was quenched with DNA addition. The Stern-Volmer equation was plotted based on the quenching fluorescence signal of daunorubicin.

  14. [Lymph node preparation in colorectal cancer. Ex vivo methylene blue injection as a novel technique to improve lymph node visualization].

    Science.gov (United States)

    Märkl, B; Kerwel, T; Jähnig, H; Anthuber, M; Arnholdt, H

    2008-07-01

    The UICC requires investigation of a minimum of 12 lymph nodes for adequate lymph node staging in colorectal cancer. Despite that, many authors recommend investigation of a larger number, and different techniques, such as fat clearance, have therefore been developed. In this study we introduce a novel technique involving ex vivo lymph node staining with intraarterial methylene blue injection in colon cancer. We compared 14 cases in which methylene injection was used with 14 cases from our records in which conventional investigation techniques were applied. The lymph node harvest differed highly significantly (pmethylene blue group and the unstained group, respectively. The largest difference occurred in the size group 2-4 mm (191 vs 70 lymph nodes). In 6 cases in the unstained group additional embedding of fatty tissue was necessary to reach an adequate number of investigated lymph nodes. Methylene blue injection is a novel and highly effective method that will improve lymph node preparation in colorectal cancer.

  15. Methylene blue microbubbles as a model dual-modality contrast agent for ultrasound and activatable photoacoustic imaging.

    Science.gov (United States)

    Jeon, Mansik; Song, Wentao; Huynh, Elizabeth; Kim, Jungho; Kim, Jeesu; Helfield, Brandon L; Leung, Ben Y C; Goertz, David E; Zheng, Gang; Oh, Jungtaek; Lovell, Jonathan F; Kim, Chulhong

    2014-01-01

    Ultrasound and photoacoustic imaging are highly complementary modalities since both use ultrasonic detection for operation. Increasingly, photoacoustic and ultrasound have been integrated in terms of hardware instrumentation. To generate a broadly accessible dual-modality contrast agent, we generated microbubbles (a standard ultrasound contrast agent) in a solution of methylene blue (a standard photoacoustic dye). This MB2 solution was formed effectively and was optimized as a dual-modality contrast solution. As microbubble concentration increased (with methylene blue concentration constant), photoacoustic signal was attenuated in the MB2 solution. When methylene blue concentration increased (with microbubble concentration held constant), no ultrasonic interference was observed. Using an MB2 solution that strongly attenuated all photoacoustic signal, high powered ultrasound could be used to burst the microbubbles and dramatically enhance photoacoustic contrast (>800-fold increase), providing a new method for spatiotemporal control of photoacoustic signal generation.

  16. PREPARATION MICRO-FILTRATION CERAMIC MEMBRANE FROM NATURAL ZEOLITE FOR PROCION RED MX8B AND METHYLENE BLUE FILTRATION

    Directory of Open Access Journals (Sweden)

    Dyah Choiriyah

    2015-12-01

    Full Text Available The study of ceramic membrane fabrication from natural zeolite and its utilization for filtration of procion red MX8B and methylene blue has been investigated. The purposes of this study are to determine the effect of pressure on membrane permeability and selectivity and utilize natural zeolite as ceramic membranes procion red MX8B and methylene blue filtration. The membrane was prepared by metide press pellets and then calcined at 850 oC. The membranes were characterized by mechanical test, flux and rejection of dye. The compression test of the membrane found the values of 1369.178 psi in dry conditions to 1388.933 psi in wet conditions. The flux test found that the higher the pressure applied, the flux was increase. However, the high pressure also decreased the selectivity. Rejection test found that the rejection of methylene blue filtration up to 70 %. Meanwhile, procion red MX8B filtration has rejectivity less than 20 %.

  17. Inhibition of hsp70 by methylene blue affects signaling protein function and ubiquitination and modulates polyglutamine protein degradation.

    Science.gov (United States)

    Wang, Adrienne M; Morishima, Yoshihiro; Clapp, Kelly M; Peng, Hwei-Ming; Pratt, William B; Gestwicki, Jason E; Osawa, Yoichi; Lieberman, Andrew P

    2010-05-21

    The Hsp90/Hsp70-based chaperone machinery regulates the activity and degradation of many signaling proteins. Cycling with Hsp90 stabilizes client proteins, whereas Hsp70 interacts with chaperone-dependent E3 ubiquitin ligases to promote protein degradation. To probe these actions, small molecule inhibitors of Hsp70 would be extremely useful; however, few have been identified. Here we test the effects of methylene blue, a recently described inhibitor of Hsp70 ATPase activity, in three well established systems of increasing complexity. First, we demonstrate that methylene blue inhibits the ability of the purified Hsp90/Hsp70-based chaperone machinery to enable ligand binding by the glucocorticoid receptor and show that this effect is due to specific inhibition of Hsp70. Next, we establish that ubiquitination of neuronal nitric-oxide synthase by the native ubiquitinating system of reticulocyte lysate is dependent upon both Hsp70 and the E3 ubiquitin ligase CHIP and is blocked by methylene blue. Finally, we demonstrate that methylene blue impairs degradation of the polyglutamine expanded androgen receptor, an Hsp90 client mutated in spinal and bulbar muscular atrophy. In contrast, degradation of an amino-terminal fragment of the receptor, which lacks the ligand binding domain and, therefore, is not a client of the Hsp90/Hsp70-based chaperone machinery, is enhanced through homeostatic induction of autophagy that occurs when Hsp70-dependent proteasomal degradation is inhibited by methylene blue. Our data demonstrate the utility of methylene blue in defining Hsp70-dependent functions and reveal divergent effects on polyglutamine protein degradation depending on whether the substrate is an Hsp90 client.

  18. Enhanced photocatalytic degradation of methylene blue on multiwalled carbon nanotubes-TiO2.

    Science.gov (United States)

    Zhao, Donglin; Yang, Xin; Chen, Changlun; Wang, Xiangke

    2013-05-15

    A visible-light photocatalyst of multiwalled carbon nanotubes decorated with TiO2 nanoparticles (MWCNT/TiO2) was synthesized by a two-step method, in which TiO2 was first mounted on MWCNT surfaces by hydrolysis of tetrabutyl titanate and further crystallized into anatase nanocrystal in a vacuum furnace at 500°C. The photocatalytic degradation of methylene blue over the ultraviolet (UV) and visible-light spectrum regions was investigated. The MWCNT/TiO2 was able to absorb a high amount of photo energy in the visible-light region, driving effectively photochemical degradation reactions. There were more OH radicals produced by the MWCNT/TiO2 (1:3) than by pure TiO2 under UV and visible-light irradiation. In the photodegradation of methylene blue, as a model reaction, a signification enhancement in the reaction rate was observed with the MWCNT/TiO2 (1:3), compared to bare TiO2 and the physical mixture of MWCNTs and TiO2. MWCNTs can improve the photocatalytic activity of TiO2 in two aspects, namely e(-) transportation and adsorption. This work provides new insight into the fabrication of MWCNT/TiO2 as a high performance visible-light photocatalyst and facilitates its application in photocatalytic degradation of organic compounds.

  19. Efficacy of SnO2 nanoparticles toward photocatalytic degradation of methylene blue dye.

    Science.gov (United States)

    Elango, Ganesh; Roopan, Selvaraj Mohana

    2016-02-01

    Maximum pollutants in the industrial and domestic waste water effluents from any sources include pathogens and organic chemicals, which can be removed before discharging into the water bodies. Methylene blue has been considered as one of the major water contaminated pollutants. Such pollutant is dominant in surface water and groundwater. It will cause irreversible hazards to human and aquatic life. Nanotechnology plays a major role in degrading such type of pollutant. In order to fulfill today's requirement, we have decided to handle the green synthesis of nanoparticles and its application by merging important fields like chemistry, environmental science, and biotechnology. Here our work emphasizes on the biological synthesis of SnO2 nanoparticles (SnO2 NPs) using the methanolic extract of Cyphomandra betacea (C.betacea), and it was confirmed by various characterization techniques such as UV-visible spectroscopy, FT-IR, XRD, SEM, particle size analyzer, zeta potential, and TEM. The obtained results stated that the synthesized SnO2 NPs were in rod shape with an average size of 21nm, which resulted in a product of nanobiotechnology. Further, we have utilized the environmental-friendly synthesized SnO2 NPs photocatalytic degradation of environmental concern methylene blue with first-order kinetics. In this paper, we have attempted to prove that secondary metabolite-entrapped SnO2 NPs are non-toxic to the environment.

  20. Determination of Surface Area of Red Mud and BeringiteUsing Methylene Blue Method

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The adsorption of methylene blue (MB) on three soil amendments, red mud from Hungary, red mud from UK and beringite from Belgium, was studied to determine the surface areas of the amendments using a 0.005 mol L-1 NaCl solution and deionised water as background solutions. The surface areas determined by the methylene blue method in the 0.005 mol L-1 NaCl solution were 3.357, 2.340 and 5.576 m2 g-1 for red nmd (Hungary), red mud (UK) and beringite, respectively, slightly lower than those in the deionised water system. The largest surface area of beringite suggested that the MB could adsorb effectively on the interlayer surface of illite. The effect of NaCl on the surface areas was relatively small and may therefore be ignored. Both the 0.005 mol L-1 NaCl solution and deionised water could be used as a background solution for measurement of surface area of oxide-rich materials.

  1. Photocatalytic activity enhancement of anatase-graphene nanocomposite for methylene removal: Degradation and kinetics.

    Science.gov (United States)

    Rezaei, Mostafa; Salem, Shiva

    2016-10-05

    In the present research, the TiO2-graphene nanocomposite was synthesized by an eco-friendly method. The blackberry juice was introduced to graphene oxide (GO) as a reducing agent to produce the graphene nano-sheets. The nanocomposite of anatase-graphene was developed as a photocatalyst for the degradation of methylene blue, owing to the larger specific surface area and synergistic effect of reduced graphene oxide (RGO). The UV spectroscopy measurements showed that the prepared nanocomposite exhibited an excellent photocatalytic activity toward the methylene blue degradation. The rate of electron transfer of redox sheets is much higher than that observed on GO, indicating the applicability of proposed method for the production of anatase-RGO nanocomposite for treatment of water contaminated by cationic dye. The prepared materials were characterized with Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer-Emmett-Teller surface area measurement, scanning electron microscopy and transmission electron microscopy. A facile and rapid route was applied for the uniform deposition of anatase nanoparticles on the sheets. The resulting nanocomposite contained nanoparticles with a mean diameter of 10nm. A mechanism for the photocatalytic activity of nanocomposite was suggested and the degradation reaction obeyed the second-order kinetics. It was concluded that the degradation kinetics is changed due to the reduction of GO in the presence of blackberry juice.

  2. Stability of isoflavone daidzein and genistein in riboflavin, chlorophyll b, or methylene blue photosensitization.

    Science.gov (United States)

    Yang, Seungok; Lee, Seungwook; Chung, Hyun; Lee, Jaehwan

    2008-03-01

    Effects of photosensitizers including riboflavin, chlorophyll b, or methylene blue on the stability of daidzein and genistein were studied in model systems by high-performance liquid chromatography (HPLC). Concentration of daidzein and genistein in 80% methanol with riboflavin under light for 7 h was significantly decreased with the apparent 1st-order rate constants of 0.234 and 0.193/h, respectively, (P 0.05). The stability of isoflavone aglycones in the dark did not change significantly irrespective of the presence of riboflavin (P > 0.05). The concentrations of daidzein and genistein in chlorophyll b or methylene blue model systems under light were not significantly different from those in the dark for 7 h (P > 0.05). Addition of sodium azide increased the stability of daidzein and genistein in riboflavin photosensitization with concentration dependent manner. However, the protective effects of beta-carotene addition on the photodegradation of isoflavones were not high. The stability difference of daidzein and genistein in riboflavin photosensitization may be due to the high reactivity of riboflavin through type I pathway, although singlet oxygen may be involved in part.

  3. A Novel ZnO-Methylene Blue Nanocomposite Matrix for Biosensing Application

    Directory of Open Access Journals (Sweden)

    Shibu Saha

    2011-01-01

    Full Text Available A novel hybrid matrix of zinc oxide-methylene blue (ZnO-MB has been successfully developed for biosensing application. The introduction of methylene blue into the ZnO thin film leads to reduction in the charge transfer resistance and suggests an increase in the electron transfer capacity of the composite. Glucose oxidase (GOx was chosen as the model enzyme and effectively immobilized on the surface of hybrid ZnO-MB nanocomposite matrix. Electrochemical measurements were employed to study biosensing response of the GOx/ZnO-MB/ITO bioelectrode as a function of glucose concentration. The low oxidation potential (−0.23 V of the hybrid bioelectrode, in a mediatorless electrolyte, makes it resistant against interference from other bio-molecules. The low value of Michaelis-Menten constant (2.65 mM indicates that immobilized GOx retains its enzymatic activity significantly on the surface of nanocomposite hybrid matrix that results in an enhanced affinity towards its substrate (glucose. The ZnO-MB nanocomposite hybrid matrix, exhibiting enhanced sensing response (0.2 μAmM−1cm−2 with long shelf-life (>10 weeks, has potential for the realization of an integrated biosensing device.

  4. Nonlinear chemoconvection in the methylene-blue-glucose system: Two-dimensional shallow layers

    Science.gov (United States)

    Pons, A. J.; Batiste, O.; Bees, M. A.

    2008-07-01

    Interfacial hydrodynamic instabilities arise in a range of chemical systems. One mechanism for instability is the occurrence of unstable density gradients due to the accumulation of reaction products. In this paper we conduct two-dimensional nonlinear numerical simulations for a member of this class of system: the methylene-blue-glucose reaction. The result of these reactions is the oxidation of glucose to a relatively, but marginally, dense product, gluconic acid, that accumulates at oxygen permeable interfaces, such as the surface open to the atmosphere. The reaction is catalyzed by methylene-blue. We show that simulations help to disassemble the mechanisms responsible for the onset of instability and evolution of patterns, and we demonstrate that some of the results are remarkably consistent with experiments. We probe the impact of the upper oxygen boundary condition, for fixed flux, fixed concentration, or mixed boundary conditions, and find significant qualitative differences in solution behavior; structures either attract or repel one another depending on the boundary condition imposed. We suggest that measurement of the form of the boundary condition is possible via observation of oxygen penetration, and improved product yields may be obtained via proper control of boundary conditions in an engineering setting. We also investigate the dependence on parameters such as the Rayleigh number and depth. Finally, we find that pseudo-steady linear and weakly nonlinear techniques described elsewhere are useful tools for predicting the behavior of instabilities beyond their formal range of validity, as good agreement is obtained with the simulations.

  5. Comparative study for the removal of methylene blue via adsorption and photocatalytic degradation.

    Science.gov (United States)

    El-Sharkawy, E A; Soliman, Afaf Y; Al-Amer, Kawthr M

    2007-06-15

    Physically and chemically activated carbons were prepared from date pits and olive stones. Titania and WO(x)-TiO(2)/MCM-41 were prepared as photoactive catalysts. Surface characterizations were investigated from ash content, pH, base neutralization capacities and FT-IR techniques. The textural characteristics, namely specific surface area (S(BET)) and pore texture, were determined from low temperature adsorption of N(2) at 77 K. The decolorization of aqueous solution of methylene blue was performed by means of two alternative methods. Steam-activated carbons own higher surface area compared with ZnCl(2)-activated carbons, and the micropore surface area represents the major contribution of the total area. Steam-activated carbons were the most efficient decolorizing adsorbents owing to its higher surface area, total pore volume and the basic nature of the surface. The calculated values of DeltaG(0), DeltaH(0) and DeltaS(0) indicate the spontaneous behavior of adsorption. The photocatalytic degradation is more convenient method in decolorizing of methylene blue compared with the adsorption process onto activated carbons.

  6. Photocatalytic activity enhancement of anatase-graphene nanocomposite for methylene removal: Degradation and kinetics

    Science.gov (United States)

    Rezaei, Mostafa; Salem, Shiva

    2016-10-01

    In the present research, the TiO2-graphene nanocomposite was synthesized by an eco-friendly method. The blackberry juice was introduced to graphene oxide (GO) as a reducing agent to produce the graphene nano-sheets. The nanocomposite of anatase-graphene was developed as a photocatalyst for the degradation of methylene blue, owing to the larger specific surface area and synergistic effect of reduced graphene oxide (RGO). The UV spectroscopy measurements showed that the prepared nanocomposite exhibited an excellent photocatalytic activity toward the methylene blue degradation. The rate of electron transfer of redox sheets is much higher than that observed on GO, indicating the applicability of proposed method for the production of anatase-RGO nanocomposite for treatment of water contaminated by cationic dye. The prepared materials were characterized with Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer-Emmett-Teller surface area measurement, scanning electron microscopy and transmission electron microscopy. A facile and rapid route was applied for the uniform deposition of anatase nanoparticles on the sheets. The resulting nanocomposite contained nanoparticles with a mean diameter of 10 nm. A mechanism for the photocatalytic activity of nanocomposite was suggested and the degradation reaction obeyed the second-order kinetics. It was concluded that the degradation kinetics is changed due to the reduction of GO in the presence of blackberry juice.

  7. Hybrid multiwalled carbon nanotube--Laponite sorbent for removal of methylene blue from aqueous solutions.

    Science.gov (United States)

    Loginov, Maksym; Lebovka, Nikolai; Vorobiev, Eugene

    2014-10-01

    The article discusses adsorption of methylene blue dye by novel hybrid sorbent consisting of Laponite and multiwalled carbon nanotubes. The sorbent was obtained by sonication of the aqueous suspensions of nanotubes at different concentrations of Laponite. The methods of the methylene blue adsorption, dead-end membrane filtration and environmental scanning electron microscopy were used for the sorbent characterization. It may be concluded from the results of filtration and adsorption experiments that sonication of mixed aqueous suspensions of Laponite and multiwalled carbon nanotubes leads to the formation of hybrid particles (ML-particles) with a core-shell structure. The size and the shape of hybrid particles were determined by nanotubes, while their adsorption properties were determined by Laponite particles attached to the surface of nanotubes. The Laponite content in hybrid particles was corresponding to the Laponite to nanotubes ratio in the initial suspension X(L)=0-1. Due to the presence of Laponite in the sorbent, its adsorbing capacity was much higher as compared to the adsorbing capacity of pure nanotubes, and it was directly proportional to the Laponite content. This sorbent may be used either as a purifying additive or as a filtering layer if it is deposited on the surface of a supporting membrane. Due to relatively large size of hybrid particles, they can be easily separated from the purified solution by filtration or centrifugation.

  8. Evaluation of COSHH essentials: methylene chloride, isopropanol, and acetone exposures in a small printing plant.

    Science.gov (United States)

    Lee, Eun Gyung; Harper, Martin; Bowen, Russell B; Slaven, James

    2009-07-01

    The current study evaluated the Control of Substances Hazardous to Health (COSHH) Essentials model for short-term task-based exposures and full-shift exposures using measured concentrations of three volatile organic chemicals at a small printing plant. A total of 188 exposure measurements of isopropanol and 187 measurements of acetone were collected and each measurement took approximately 60 min. Historically, collected time-weighted average concentrations (seven results) were evaluated for methylene chloride. The COSHH Essentials model recommended general ventilation control for both isopropanol and acetone. There was good agreement between the task-based exposure measurements and the COSHH Essentials predicted exposure range (PER) for cleaning and print preparation with isopropanol and for cleaning with acetone. For the other tasks and for full-shift exposures, agreement between the exposure measurements and the PER was either moderate or poor. However, for both isopropanol and acetone, our findings suggested that the COSHH Essentials model worked reasonably well because the probabilities of short-term exposure measurements exceeding short-term occupational exposure limits (OELs) or full-shift exposures exceeding the corresponding full-shift OELs were <0.05 under the recommended control strategy. For methylene chloride, the COSHH Essentials recommended containment control but a follow-up study was not able to be performed because it had already been replaced with a less hazardous substance (acetone). This was considered a more acceptable alternative to increasing the level of control.

  9. Treatment of dilute methylene blue-containing wastewater by coupling sawdust adsorption and electrochemical regeneration.

    Science.gov (United States)

    Bouaziz, I; Chiron, C; Abdelhedi, R; Savall, A; Groenen Serrano, K

    2014-01-01

    In the present work, the coupling of adsorption and electrochemical oxidation on a boron-doped diamond (BDD) electrode to treat solutions containing dyes is studied. This coupling may be convenient for the treatment of diluted pollutant that is limited by the low rate of electrooxidation due to mass-transfer limitation. A pre-concentration step by adsorption could minimize the design of the electrochemical reactor. The adsorbent chosen was mixed with softwood sawdust, and methylene blue was chosen as the model dye molecule. Isotherms of adsorption and kinetics were investigated as well as the effects of current density and regeneration time. The BDD electrochemical oxidation of methylene blue adsorbed onto sawdust led simultaneously to its degradation and sawdust regeneration for the next adsorption. It was observed that multiple adsorption and electrochemical regeneration cycles led to an enhancement of adsorption capacity of the sawdust. This study demonstrated that adsorption–electrochemical degradation coupling offers a promising approach for the efficient elimination of organic dyes from wastewater.

  10. Removal of methylene blue from aqueous solution using cotton stalk, cotton waste and cotton dust

    Energy Technology Data Exchange (ETDEWEB)

    Ertas, Murat [Department of Forest Industrial Engineering, Faculty of Forestry, Kahramanmaras Sutcu Imam University, 46060 Kahramanmaras (Turkey); Acemioglu, Bilal, E-mail: acemioglu@kilis.edu.tr [Department of Chemistry, Faculty of Science and Arts, Kilis 7 Aralik University, 79000 Kilis (Turkey); Alma, M. Hakki [Department of Forest Industrial Engineering, Faculty of Forestry, Kahramanmaras Sutcu Imam University, 46060 Kahramanmaras (Turkey); Usta, Mustafa [Department of Forest Industrial Engineering, Faculty of Forestry, Karadeniz Technical University, 61080 Trabzon (Turkey)

    2010-11-15

    In this study, cotton stalk (CS), cotton waste (CW) and cotton dust (CD) was used as sorbents to remove methylene blue (MB) from aqueous solution by batch sorption technique. Effects of initial dye concentration, solution pH, solution temperature and sorbent dose on sorption were studied. It was seen that the removal of methylene blue increased with increasing initial dye concentration (from 25 to 100 mg/l), solution pH (from 5 to 10), solution temperature (from 20 to 50 deg. C) and sorbent dose (from 0.25 to 1.50 g/50 ml). The maximum dye removal was reached at 90 min. Sorption isotherms were analyzed by Langmuir and Freundlich models at different temperatures of 20, 30, 40 and 50 deg. C, and the results were discussed in detail. Moreover, the thermodynamics of sorption were also studied. It was found that the values of standard free energy ({Delta}G{sup o}) were positive for cotton stalk and negative for cotton waste and cotton dust. The values of standard enthalpy ({Delta}H{sup o}) and entropy ({Delta}S{sup o}) were found to be positive, and the obtained results were interpreted in detail. The results of this study showed that cotton stalk, cotton waste and cotton dust could be employed as effective and low-cost materials for the removal of dyes from aqueous solution.

  11. Enhanced photocatalytic degradation of methylene blue by metal-modified silicon nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Brahiti, N., E-mail: dihiabrahiti@yahoo.fr [Centre de Recherche en Technologie des Semi-conducteurs pour l' Energétique (CRTSE), 2 Bd. Frantz Fanon, B.P. 140 Alger-7 Merveilles, Alger (Algeria); Université Mouloud MAMMERI de TiziOuzou, Département de Physique, Bastos (Algeria); Hadjersi, T., E-mail: hadjersi@gmx.com [Centre de Recherche en Technologie des Semi-conducteurs pour l' Energétique (CRTSE), 2 Bd. Frantz Fanon, B.P. 140 Alger-7 Merveilles, Alger (Algeria); Menari, H. [Centre de Recherche en Technologie des Semi-conducteurs pour l' Energétique (CRTSE), 2 Bd. Frantz Fanon, B.P. 140 Alger-7 Merveilles, Alger (Algeria); Amirouche, S.; El Kechai, O. [Université Mouloud MAMMERI de TiziOuzou, Département de Physique, Bastos (Algeria)

    2015-02-15

    Highlights: • SiNWs modified with Pd, Au and Pt were used as photocatalysts to degrade MB. • Yield of photodegardation increases with UV irradiation time. • SiNWs modified with Pd nanoparticles show the best photocatalytic activity. • A degradation of 97% was obtained after 200 min of UV irradiation. - Abstract: Silicon nanowires (SiNWs) modified with Au, Pt and Pd nanoparticles were used as heterogeneous photocatalysts for the photodegradation of methylene blue in water under UV light irradiation. The modification of SiNWs was carried out by deposition of metal nanoparticles using the electroless metal deposition (EMD) technique. The effect of metal nanoparticles deposition time on the photocatalytic activity was studied. It was found that the photocatalytic activity of modified SiNWs was enhanced when the deposition time of metal nanoparticles was increased. In addition of modified SiNWs with Pt, Au and Pd nanoparticles, oxidized silicon substrate (Ox-Si), oxidized silicon nanowires (Ox-SiNWs) and hydrogen-terminated silicon nanowires (H-SiNWs) were also evaluated for the photodegradation of methylene blue.

  12. Theoretical study on the mechanism of cycloaddition between dimethyl methylene carbene and acetone

    Institute of Scientific and Technical Information of China (English)

    LU Xiuhui; WU Weirong; YU Haibin; XU Yuehua

    2005-01-01

    The mechanism of the cycloaddition reaction of singlet dimethyl methylene carbene and acetone has been studied by using second-order Moller-Plesset perturbation and density functional theory. The geometrical parameters, harmonic vibrational frequencies and energy of stationary points on the potential energy surface are calculated by MP2/6-31G* and B3LYP/6-31G* methods. The results show that path b of the cycloaddition reaction (1) would be the major reactive channel of the cycloaddition reaction between singlet dimethyl methylene carbene and acetone, which proceeds in two steps: i) The two reactants form an energy-rich intermediate (INT1b), which is an exothermic reaction of 23.3 kJ/mol with no energy barrier. ii) The intermediate INT1b isomerizes to a three-membered ring product (P1) via transition state TS1b with energy barrier of 22.2 kJ/mol. The reaction rate of this reaction and its competitive reactions do greatly differ, with excellent selectivity. In view of dynamics and thermodynamics, this reaction is suitable for occurring at 1 atm and temperature range of 300―800 K, in which the reaction will have not only the larger spontaneous tendency and equilibrium constant but also the faster reaction rate.

  13. Electrochemical behavior of an anticancer drug 5-fluorouracil at methylene blue modified carbon paste electrode

    Energy Technology Data Exchange (ETDEWEB)

    Bukkitgar, Shikandar D.; Shetti, Nagaraj P., E-mail: dr.npshetti@gmail.com

    2016-08-01

    A novel sensor for the determination of 5-fluorouracil was constructed by electrochemical deposition of methylene blue on surface of carbon paste electrode. The electrode surface morphology was studied using Atomic force microscopy and XRD. The electrochemical activity of modified electrode was characterized using cyclic voltammetry and differential pulse method. The developed sensor shows impressive enlargement in sensitivity of 5-fluorouracil determination. The peak currents obtained from differential pulse voltammetry was linear with concentration of 5-fluorouracil in the range 4 × 10{sup −5}–1 × 10{sup −7} M and detection limit and quantification limit were calculated to be 2.04 nM and 6.18 nM respectively. Further, the sensor was successfully applied in pharmaceutical and biological fluid sample analysis. - Highlights: • Electrochemical oxidation of 5-fluorouracil has been investigated for first time at methylene blue modified carbon paste electrode • The electrode process was irreversible and diffusion controlled • Probable electrochemical mechanism was proposed which involved two proton and two electron transfer reaction • The LOD and LOQ values were calculated to be 2.04 nM and 6.18 nM, respectively, with good selectivity and sensitivity. • Proposed method was applied to 5-Fluorouracil determination in pharmaceutical and spiked human urine samples.

  14. Synthesis and characterization of magnetic palygorskite nanoparticles and their application on methylene blue remotion from water

    Science.gov (United States)

    Middea, Antonieta; Spinelli, Luciana S.; Souza, Fernando G.; Neumann, Reiner; Gomes, Otavio da F. M.; Fernandes, Thais L. A. P.; de Lima, Luiz C.; Barthem, Vitoria M. T. S.; de Carvalho, Fernanda V.

    2015-08-01

    Recently there has been considerable interest in magnetic sorbents materials, which is added excellent capabilities such as sorption and magnetic response to an applied field. Accordingly, palygorskite nanoparticles were covered by magnetite using a co-precipitation technique and characterized by: X-ray fluorescence (XRF), X-ray diffraction (XRD), surface analysing and scanning electron microscopy (SEM) with element analysis and mapping, particle size, pore surface area (BET), density, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and zeta potential. Additionally, magnetic properties were studied by SQUID magnetometer, magnetic force microscopy (MFM) and also using a simple experimental setup. Magnetic nanoparticles produced had average diameters in a nanometric range. The amount of iron present in the nanoparticles increased by six times after the magnetization and a superparamagnetic behavior was exhibited with high saturation magnetization, from 4.0 × 10-4 Am2/kg to about 20 Am2/kg. A weight loss was also observed around 277 °C-339 °C by TGA, indicating a structural change from magnetite to maghemite, which confirms the magnetization of palygorskite. Batch adsorption experiments were carried out for the removal of methylene blue cationic dye from aqueous solution using pure and covered by magnetite palygorskite nanoparticles as adsorbents. Furthermore, about 90% of methylene blue was removed within 3 min using magnetized palygorskite.

  15. A study of the Fenton-mediated oxidation of methylene blue-cucurbit[n]uril complexes.

    Science.gov (United States)

    Fuenzalida, Tomás; Fuentealba, Denis

    2015-04-01

    Cucurbit[n]urils efficiently decreased the Fenton-mediated oxidation of encapsulated dyes, providing a mechanism for some control and selectivity over the degradation. The encapsulation of methylene blue into cucurbit[7]uril made it highly refractory against Fenton oxidation in the dark or under UVA light irradiation. However, the oxidation of the encapsulated dye was significantly enhanced under visible light irradiation. This behavior was selective for the cucurbit[7]uril complex and not for the cucurbit[8]uril complex, which achieved the same degree of protection irrespective of the irradiation conditions. This different reactivity of the complexes was further discussed in terms of their excited state properties. The main mechanism for protection was the seclusion of the dye into cucurbit[n]urils as shown by the fact that the non-encapsulated dye safranin was protected much less than methylene blue. Additionally, cucurbit[n]urils efficiently trapped hydroxyl radicals, which contributed significantly to the protection of the dyes from Fenton-mediated oxidation.

  16. Supramolecular hybrids of polytungstates and their adsorption properties for methylene blue

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yunping; Zheng, Ran; Han, Zhangang, E-mail: hanzg116@126.com; Gong, Kaining; He, Xueli; Zhai, Xueliang

    2015-11-15

    Two supramolecular hybrids [Ni(mbpy){sub 3}]{sub 2}[V{sub 2}W{sub 4}O{sub 19}]·6H{sub 2}O (1) and [Ni(mbpy){sub 3}]{sub 2}[VW{sub 12}O{sub 40}] (2) (mbpy=4,4′-dimethyl-2,2′-bipyridyl) had been synthesized and characterized. Single crystal X-ray diffraction analyses revealed that the anionic moieties in two hybrids belong to typical Lindqvist and α-Keggin-type structures, respectively. The counter ion [Ni(mbpy){sub 3}]{sup 2+} units were anchored to the polyanions via non-covalent intermolecular interactions. These supramolecular hybrids exhibit reversible adsorption–desorption performance for organic dye methylene blue (MB). Hybrid 2 shows a fast adsorption behavior towards MB and a relatively high value can be reached within 5 min in dark. Both 1 and 2 are structurally stable and can be easily separated from the reaction system for reuse. - Graphical abstract: Supramolecular hybrids of polytungstates have been synthesized and characterized, which exhibit the reversible adsorption–desorption performance for organic dye methylene blue.

  17. Adsorptional removal of methylene blue by guar gum-cerium (IV) tungstate hybrid cationic exchanger.

    Science.gov (United States)

    Gupta, V K; Pathania, Deepak; Singh, Pardeep; Kumar, Amit; Rathore, B S

    2014-01-30

    Guar gum-cerium (IV) tungstate nanocomposite (GG/CTNC) cationic exchanger was synthesized using simple sol gel method. The GG/CTNC was characterized using X-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray spectrophotometer (EDX). The XRD studies confirmed amorphous and fibrous in nature of GG/CTNC. The high percentage of oxygen in the nanocomposite material confirmed the functionality tungstate (WO4(-)). The ion exchange capacity of GG/CTNC for Na(+) ion was observed to be 1.30 mequivg(-1). The hybrid exchanger was used as potential adsorbent for the removal of methylene blue (MB) from aqueous system. The correlation coefficients value indicated a good fit of monolayer Langmuir model to the adsorption of methylene blue onto GG/CTNC. The adsorption kinetic study revealed that the adsorption process followed the pseudo second order kinetic. The Gibbs free energy (ΔG) values confirmed the spontaneous nature of adsorption process.

  18. Methylene Blue-Aided In Vivo Staining of Central Airways during Flexible Bronchoscopy

    Directory of Open Access Journals (Sweden)

    Sabine Zirlik

    2012-01-01

    Full Text Available Background. The early diagnosis of malignant and premalignant changes of the bronchial mucosa remains a major challenge during bronchoscopy. Intravital staining techniques are not new. Previous small case series suggested that analysis of the bronchial mucosal surface using chromoendoscopy allows a prediction between neoplastic and nonneoplastic lesions. Objectives. The aim of the present study was to evaluate chromobronchoscopy as a method to identify malignant and premalignant lesions in the central airways in a prospective manner. Methods. In 26 patients we performed chromoendoscopy with 0.1% methylene blue during ongoing flexible white light bronchoscopy. Circumscribed lesions in central airways were further analyzed by biopsies and histopathologic examination. Results. In the majority of cases neither flat nor polypoid lesions in the central airways were stained by methylene blue. In particular, exophytic growth of lung cancer did not show any specific pattern in chromobronchoscopy. However, a specific dye staining was detected in one case where exophytic growth of metastatic colorectal cancer was present in the right upper lobe. In two other cases, a circumscribed staining was noted in unsuspicious mucosa. But histology revealed inflammation only. Conclusions. In contrast to previous studies, the present findings clearly indicate that chromobronchoscopy is not useful for early detection of malignant or premalignant lesions of the central airways.

  19. Potential biosorbent derived from Calligonum polygonoides for removal of methylene blue dye from aqueous solution.

    Science.gov (United States)

    Nasrullah, Asma; Khan, Hizbullah; Khan, Amir Sada; Man, Zakaria; Muhammad, Nawshad; Khan, Muhammad Irfan; Abd El-Salam, Naser M

    2015-01-01

    The ash of C. polygonoides (locally called balanza) was collected from Lakki Marwat, Khyber Pakhtunkhwa, Pakistan, and was utilized as biosorbent for methylene blue (MB) removal from aqueous solution. The ash was used as biosorbent without any physical or chemical treatment. The biosorbent was characterized by using various techniques such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The particle size and surface area were measured using particle size analyzer and Brunauer-Emmett-Teller equation (BET), respectively. The SEM and BET results expressed that the adsorbent has porous nature. Effects of various conditions such as initial concentration of methylene blue (MB), initial pH, contact time, dosage of biosorbent, and stirring rate were also investigated for the adsorption process. The rate of the adsorption of MB on biomass sample was fast, and equilibrium has been achieved within 1 hour. The kinetics of MB adsorption on biosorbent was studied by pseudo-first- and pseudo-second-order kinetic models and the pseudo-second-order has better mathematical fit with correlation coefficient value (R (2)) of 0.999. The study revealed that C. polygonoides ash proved to be an effective, alternative, inexpensive, and environmentally benign biosorbent for MB removal from aqueous solution.

  20. Kinetics and thermodynamics of adsorption of methylene blue by a magnetic graphene-carbon nanotube composite

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peifang; Cao, Muhan; Wang, Chao; Ao, Yanhui, E-mail: andyao@hhu.edu.cn; Hou, Jun; Qian, Jin

    2014-01-30

    A solvothermal method was employed to prepare a novel magnetic composite adsorbent composed of graphene, multi-walled carbon nanotubes (MWCNTs) and Fe{sub 3}O{sub 4} nanoparticles. The prepared adsorbents were characterized by X-ray diffraction, scanning electron microscopy and X-ray fluorescence spectrometry and Fourier transform infrared spectroscopy. Fourier transform infrared spectroscopy and the particle size distribution of the samples before and after adsorption was also carried out. The performance of as-prepared composites was investigated by the adsorption of dye methylene blue. Results showed that the maximum adsorption capacity of the samples was up to 65.79 mg g{sup −1}, which was almost equal to the sum of magnetic graphene and magnetic MWCNTs. The effect of pH and temperature on the adsorption performance of methylene blue onto the magnetic adsorbents was investigated. The kinetic was well-described by pseudo-second-order and intraparticle diffusion model, while the isotherm obeyed the Langmuir isotherm. Furthermore, the as-prepared composites were found to be regenerative and reusable. The application in the treatment of an artificial dye wastewater and its cost estimation were also discussed. Therefore, the as-prepared magnetic composites can be severed as a potential adsorbent for removal of dye pollutant, owing to its high adsorption performance, magnetic separability and efficient recyclable property.

  1. [Adsorption of methylene blue from aqueous solution onto magnetic Fe3O4/ graphene oxide nanoparticles].

    Science.gov (United States)

    Chang, Qing; Jiang, Guo-Dong; Hu, Meng-Xuan; Huang, Jia; Tang, He-Qing

    2014-05-01

    A simple ultrasound-assisted co-precipitation method was developed to prepare magnetic Fe3O4/graphene oxide (Fe3O4/ GO) nanoparticles. The characterization with transmission electron microscope (TEM) indicated that the products possessed small particle size. The hysteresis loop of the dried Fe3O4/GO nanoparticles demonstrated that the sample had typical features of superparamagnetic material. Batch adsorption studies were carried out to investigate the effects of the initial pH of the solution, the dosage of adsorbent, the contact time and temperature on the adsorption of methylene blue. The results indicated that the composites prepared could be used over a broad pH range (pH 6-9). The adsorption process was very fast within the first 25 min and the equilibrium was reached at 180 min. The adsorption equilibrium and kinetics data fitted well with the Langmuir isotherm model and the pseudo-second-order kinetic model. The adsorption process was a spontaneous and endothermic process in nature. The composite exhibited fairly high adsorption capacity (196.5 mg.g-1) of methylene blue at 313 K. In addition, the magnetic composite could be effectively and simply separated by using an external magnetic field, and then regenerated by hydrogen peroxide and recycled for further use. The results indicated that the adsorbent had a potential in the application of the dye wastewater treatment.

  2. Kinetics and thermodynamics of adsorption of methylene blue by a magnetic graphene-carbon nanotube composite

    Science.gov (United States)

    Wang, Peifang; Cao, Muhan; Wang, Chao; Ao, Yanhui; Hou, Jun; Qian, Jin

    2014-01-01

    A solvothermal method was employed to prepare a novel magnetic composite adsorbent composed of graphene, multi-walled carbon nanotubes (MWCNTs) and Fe3O4 nanoparticles. The prepared adsorbents were characterized by X-ray diffraction, scanning electron microscopy and X-ray fluorescence spectrometry and Fourier transform infrared spectroscopy. Fourier transform infrared spectroscopy and the particle size distribution of the samples before and after adsorption was also carried out. The performance of as-prepared composites was investigated by the adsorption of dye methylene blue. Results showed that the maximum adsorption capacity of the samples was up to 65.79 mg g-1, which was almost equal to the sum of magnetic graphene and magnetic MWCNTs. The effect of pH and temperature on the adsorption performance of methylene blue onto the magnetic adsorbents was investigated. The kinetic was well-described by pseudo-second-order and intraparticle diffusion model, while the isotherm obeyed the Langmuir isotherm. Furthermore, the as-prepared composites were found to be regenerative and reusable. The application in the treatment of an artificial dye wastewater and its cost estimation were also discussed. Therefore, the as-prepared magnetic composites can be severed as a potential adsorbent for removal of dye pollutant, owing to its high adsorption performance, magnetic separability and efficient recyclable property.

  3. Adsorption capacity of methylene blue, an organic pollutant, by montmorillonite clay

    KAUST Repository

    Feddal, I.

    2013-11-19

    The isotherms and kinetics of the adsorption of a cationic dye in aqueous solution, methylene blue, on a local Algerian montmorillonite clay mineral (raw, sodium and thermally activated at 300 and 500°C) were determined experimentally. Various parameters influencing the adsorption were optimized, mainly solid-liquid contact time, mass of adsorbent, initial concentration of dye, pH of the solution and temperature. Results showed that the adsorption kinetics were fast: 30 min for the raw clay mineral, and 20 min for sodium clay mineral (SC) and thermally activated at 300°C, whereas with the clay mineral calcined at 500°C, the equilibrium was reached after 150 min only. The maximum adsorption capacity was reached at pH 6.6. Results deducted from the adsorption isotherms also showed that the retention follows the Langmuir model. In addition, it was found that the kinetics were in the order of 2 (K = 2.457 × 106 g/mg.h) for sodium clay and were limited by an intra-particle diffusion. SC was found to be a better adsorbent to remove methylene blue from industrial wastewater. © 2013 Balaban Desalination Publications. All rights reserved.

  4. Isatin Derived Spirocyclic Analogues with α-Methylene-γ-butyrolactone as Anticancer Agents: A Structure-Activity Relationship Study.

    Science.gov (United States)

    Rana, Sandeep; Blowers, Elizabeth C; Tebbe, Calvin; Contreras, Jacob I; Radhakrishnan, Prakash; Kizhake, Smitha; Zhou, Tian; Rajule, Rajkumar N; Arnst, Jamie L; Munkarah, Adnan R; Rattan, Ramandeep; Natarajan, Amarnath

    2016-05-26

    Design, synthesis, and evaluation of α-methylene-γ-butyrolactone analogues and their evaluation as anticancer agents is described. SAR identified a spirocyclic analogue 19 that inhibited TNFα-induced NF-κB activity, cancer cell growth and tumor growth in an ovarian cancer model. A second iteration of synthesis and screening identified 29 which inhibited cancer cell growth with low-μM potency. Our data suggest that an isatin-derived spirocyclic α-methylene-γ-butyrolactone is a suitable core for optimization to identify novel anticancer agents.

  5. Sulfonamide antibiotic removal and nitrogen recovery from synthetic urine by the combination of rotating advanced oxidation contactor and methylene urea synthesis process.

    Science.gov (United States)

    Fukahori, S; Fujiwara, T; Ito, R; Funamizu, N

    2015-01-01

    The combination of nitrogen recovery and pharmaceutical removal processes for livestock urine treatment were investigated to suppress the discharge of pollutants and recover nitrogen as resources. We combined methylene urea synthesis from urea and adsorption and photocatalytic decomposition of sulfonamide antibiotic using rotating advanced oxidation contactor (RAOC) contained for obtaining both safe fertilizer and reclaimed water. The methylene urea synthesis could recover urea in synthetic urine, however, almost all sulfonamide antibiotic was also incorporated, which is unfavorable from a safety aspect if the methylene urea is to be used as fertilizer. Conversely, RAOC could remove sulfonamide antibiotic without consuming urea. It was also confirmed that the methylene urea could be synthesized from synthetic urine treated by RAOC. Thus, we concluded that RAOC should be inserted prior to the nitrogen recovery process for effective treatment of urine and safe use of methylene urea as fertilizer.

  6. Methylene blue not ferrocene: Optimal reporters for electrochemical detection of protease activity.

    Science.gov (United States)

    González-Fernández, Eva; Avlonitis, Nicolaos; Murray, Alan F; Mount, Andrew R; Bradley, Mark

    2016-10-15

    Electrochemical peptide-based biosensors are attracting significant attention for the detection and analysis of proteins. Here we report the optimisation and evaluation of an electrochemical biosensor for the detection of protease activity using self-assembled monolayers (SAMs) on gold surfaces, using trypsin as a model protease. The principle of detection was the specific proteolytic cleavage of redox-tagged peptides by trypsin, which causes the release of the redox reporter, resulting in a decrease of the peak current as measured by square wave voltammetry. A systematic enhancement of detection was achieved through optimisation of the properties of the redox-tagged peptide; this included for the first time a side-by-side study of the applicability of two of the most commonly applied redox reporters used for developing electrochemical biosensors, ferrocene and methylene blue, along with the effect of changing both the nature of the spacer and the composition of the SAM. Methylene blue-tagged peptides combined with a polyethylene-glycol (PEG) based spacer were shown to be the best platform for trypsin detection, leading to the highest fidelity signals (characterised by the highest sensitivity (signal gain) and a much more stable background than that registered when using ferrocene as a reporter). A ternary SAM (T-SAM) configuration, which included a PEG-based dithiol, minimised the non-specific adsorption of other proteins and was sensitive towards trypsin in the clinically relevant range, with a Limit of Detection (LoD) of 250pM. Kinetic analysis of the electrochemical response with time showed a good fit to a Michaelis-Menten surface cleavage model, enabling the extraction of values for kcat and KM. Fitting to this model enabled quantitative determination of the solution concentration of trypsin across the entire measurement range. Studies using an enzyme inhibitor and a range of real world possible interferents demonstrated a selective response to trypsin

  7. Kinetics analysis for development of a rate constant estimation model for ultrasonic degradation reaction of methylene blue.

    Science.gov (United States)

    Kobayashi, Daisuke; Honma, Chiemi; Matsumoto, Hideyuki; Takahashi, Tomoki; Kuroda, Chiaki; Otake, Katsuto; Shono, Atsushi

    2014-07-01

    Ultrasound has been used as an advanced oxidation method for wastewater treatment. Sonochemical degradation of organic compounds in aqueous solution occurs by pyrolysis and/or reaction with hydroxyl radicals. Moreover, kinetics of sonochemical degradation has been proposed. However, the effect of ultrasonic frequency on degradation rate has not been investigated. In our previous study, a simple model for estimating the apparent degradation rate of methylene blue was proposed. In this study, sonochemical degradation of methylene blue was performed at various frequencies. Apparent degradation rate constant was evaluated assuming that sonochemical degradation of methylene blue was a first-order reaction. Specifically, we focused on effects of ultrasonic frequency and power on rate constant, and the applicability of our proposed model was demonstrated. Using this approach, maximum sonochemical degradation rate was observed at 490 kHz, which agrees with a previous investigation into the effect of frequency on the sonochemical efficiency value evaluated by KI oxidation dosimetry. Degradation rate increased with ultrasonic power at every frequency. It was also observed that threshold power must be reached for the degradation reaction to progress. The initial methylene blue concentration and the apparent degradation rate constant have a relation of an inverse proportion. Our proposed model for estimating the apparent degradation rate constant using ultrasonic power and sonochemical efficiency value can apply to this study which extended the frequency and initial concentration range.

  8. Desorption and photodegradation of methylene blue from modified sugarcane bagasse surface by acid TiO{sub 2} hydrosol

    Energy Technology Data Exchange (ETDEWEB)

    Yu Junxia [Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430074 (China); Chi Ruan, E-mail: rac_wit@yahoo.cn [Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430074 (China); Guo Jia; Zhang Yuefei; Xu Zhigao; Xiao Chunqiao [Hubei Novel Reactor and Green Chemical Technology Key Laboratory, Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430074 (China)

    2012-02-01

    Waste sugarcane bagasse (SCB) was modified by pyromellitic dianhydride to improve its adsorption capacity for cationic dyes. Results showed that the adsorption capacity of the modified SCB for methylene blue was 564 mg g{sup -1}, which was about 12 times than that obtained on the unmodified SCB. Methylene blue loaded modified SCB was regenerated by a self-clean eluent: TiO{sub 2} hydrosol with pH ranged from 1 to 4, and HNO{sub 3} solution with the same pH range was tested at the same time for comparison. Results showed that desorption kinetics of methylene blue in the hydrosol systems fit two-step kinetic model and controlled mainly by the slow step. As a self-clean eluent, acid hydrosol could firstly desorb and then photodegrade methylene blue under sunlight irradiation. After five desorption-photodegradation cycles, 78.3% of the absorbed dyes could be desorbed by using hydrosol (pH 2) as eluent. The hydrosol could be continuously used in desorption and photodegradation process, which would economize large volume of the eluent and moreover it would not bring secondary pollution.

  9. Applied research of the combination of indocyanine green and methylene blue in mapping sentinel lymph nodes for breast cancer patients

    Institute of Scientific and Technical Information of China (English)

    Ren-Zhong Cui; Jie-Hui Yang; Cheng-Xin Pan

    2016-01-01

    Objective:To discuss the application value of combination of indocyanine green and methylene blue in sentinel lymph node biopsy for patients with breast cancer. Methods:A total of 200 cases of breast cancer patients were selected and randomly divided into test group and control group, each of 100 cases. The test group received indocyanine green and methylene blue as the lymphatic mapping tracers and the control group received methylene blue only. Intraoperative frozen section was performed, followed by conventional histopathology. Results:Thepositive rate, sensitivity, false negative rate, consistent rate and the Kappa values of the test group were 98%(98/100), 95.74%(45/47), 4.26%(2/47), 96.94%%(95/98) and 0.860, and 94%(94/100) and 86.96%(40/46), 13.04%(6/46), 93.62%(88/94) and 0.758 of control group;There were statistical significance between the differences of the positive rate, sensitivity, false negative rate, consistent rate and the Kappa values of test group and control group. Conclusion:Combination of indocyanine green and methylene blue for mapping sentinel lymph nodes in breast cancer patients has the advantages of real-time visual and accurate positioning and can reduce the false negative rate, to provide the important evidence based medicine foundation for the surgical treatment of breast cancer.

  10. Viability of the Fricke dosemeter doped with methylene blue; Viabilidade do dosimetro Fricke dopado com azul de metileno

    Energy Technology Data Exchange (ETDEWEB)

    Souza, V.L.B.; Santos, C.D.A.; Rodrigues, K.R.G.; Cunha, M.S.; Figueiredo, M.D.C.; Melo, R.T. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2009-07-01

    This work aims to find the possible utilization of the Fricke dosemeter doped with methylene blue (FMB) for the dosimetry of photodynamic therapy. The FMB was irradiated wit X rays and light emitted diodes demonstrating positive answers to the stimulus, being probably to be used for dosimetric objectives

  11. Effects of post-session administration of methylene blue on fear extinction and contextual memory in adults with claustrophobia

    NARCIS (Netherlands)

    Telch, M.J.; Bruchey, A.K.; Rosenfield, D.; Cobb, A.R.; Smits, J.A.J.; Pahl, S.; Gonzalez-Lima, F.

    2014-01-01

    Administering methylene blue, a memory-enhancing agent, after successful exposure therapy promoted the retention of fear extinction in claustrophobic patients, but clinicians should carefully consider what level of fear reduction was achieved in session to avoid harmful effects. Objective Preclinica

  12. Thermodynamic and kinetic characterization of duplex formation between 2'-O, 4'-C-methylene-modified oligoribonucleotides, DNA and RNA

    DEFF Research Database (Denmark)

    Christensen, Ulla

    2007-01-01

    2'-O,4'-C-methylene-linked ribonucleotide derivatives, named LNA (locked nucleic acid) and BNA (bridged nucleic acid) are nucleic acid analogoues that have shown high-affinity recognition of DNA and RNA, and the employment of LNA oligomers for antisense activity, gene regulation and nucleic acid...... the strength of duplexes formed with the complementary DNA and RNA....

  13. Stereoselectivity in metallocene-catalyzed coordination polymerization of renewable methylene butyrolactones: From stereo-random to stereo-perfect polymers

    KAUST Repository

    Chen, Xia

    2012-05-02

    Coordination polymerization of renewable α-methylene-γ-(methyl) butyrolactones by chiral C 2-symmetric zirconocene catalysts produces stereo-random, highly stereo-regular, or perfectly stereo-regular polymers, depending on the monomer and catalyst structures. Computational studies yield a fundamental understanding of the stereocontrol mechanism governing these new polymerization reactions mediated by chiral metallocenium catalysts. © 2012 American Chemical Society.

  14. Single incision laparoscopic surgery approach for obscure small intestine bleeding localized by CT guided percutaneous injection of methylene blue

    Directory of Open Access Journals (Sweden)

    Juan Carlos Martinez

    2014-01-01

    PRESENTATION OF CASE: We present a new technique used in a patient with angiodysplasia of the small intestine, in where preoperative localization was done using percutaneous computed tomography (CT guided injection of methylene blue dye. This allowed us to perform a single incision laparoscopic small intestine resection of the culprit.

  15. Radioiodinated methylene blue--a promising agent for melanoma scintigraphy: labelling, stability and in vitro uptake by melanoma cells.

    Science.gov (United States)

    Sobal, Grazyna; Rodrigues, Margarida; Sinzinger, Helmut

    2008-01-01

    Melanoma is a tumor of continuously increasing incidence for which new methods of imaging and targeted therapy are widely sought. Radioiodinated methylene blue is a promising tracer, showing selective uptake in human pigmented melanoma cells. We performed 131I-labeling of the tracer using 1% methylene blue injection United States Pharmacopeia (USP) and 131I sodium iodide. For quality control, a Merck high performance liquid chromatography (HPLC) system was used. We developed a new HPLC procedure using 0.1% trifluoroacetic acid, 90% acetonitrile and 10% water as solvent for isocratic elution of the tracer and applied a TLC method using ITLC-SG strips and the same solvent. The stability of the preparation was studied for 15 min, 3 h and 6 h. In order to evaluate the potential relevance of 131I-labeled methylene blue for melanoma detection, the in vitro uptake of 131I-methylene blue was investigated in SK-MEL 28 and 518A2 melanoma cells. Time and a temperature influence on uptake of 1311 methylene blue by these two melanoma cells were investigated. The radiochemical purity obtained by the HPLC method was 99.97 +/- 0.08% (n=8), while that by the TLC method was 99.88 +/- 0.16% (n=8). This indicates the excellent agreement between these two methods. The stability was persistent over 6 h and amounted to 99.75% +/- 0.21% (n=8). The uptake of 131I methylene blue was time and temperature dependent by both melanoma cells lines. The net cellular uptake on incubation at 37 degrees C of 131I methylene blue by SK-MEL 28 cells was high at 56.3-61.8% and that by 518A2-cells was 36.3-56.0%. Uptake by these cells was also investigated at 22 degrees C. The uptake by both cell types was also high at this temperature, but lower than that at 37 degrees C, amounting to 45.0-51.7% and 25.6-36.3%, respectively. Due to its easy handling and quite high uptake by melanoma cells, we expect that this tracer could be successfully used in routine application for melanoma imaging or eventual

  16. 2-(Hetero(aryl)methylene)hydrazine-1-carbothioamides as potent urease inhibitors.

    Science.gov (United States)

    Saeed, Aamer; Imran, Aqeel; Channar, Pervaiz A; Shahid, Mohammad; Mahmood, Wajahat; Iqbal, Jamshed

    2015-02-01

    A small series of 2-(hetero(aryl)methylene) hydrazine-1-carbothioamides including two aryl derivatives was synthesized and tested for their inhibitory activity against urease. Compound (E)-2-(Furan-2-ylmethylene) hydrazine-1-carbothioamide (3f), having a furan ring, was the most potent inhibitor of urease with an IC50 value of 0.58 μM. Molecular modeling was carried out through docking the designed compounds into the urease binding site to predict whether these derivatives have analogous binding mode to the urease inhibitors. The study revealed that all of the tested compounds bind with both metal atoms at the active site of the enzyme. The aromatic ring of the compounds forms ionic interactions with the residues, Ala(440), Asp(494), Ala(636), and Met(637).

  17. Kinetics and mechanism of the adsorption of methylene blue onto ACFs

    Institute of Scientific and Technical Information of China (English)

    YANG Zhi-yuan

    2008-01-01

    The kinetics and mechanism of methylene blue (MB) adsorption onto activated carbon fibers (ACFs) have been studied.The effects of various experimental parameters, such as the initial MB concentration and the ACF mass, on the adsorption rate were investigated. Equilibrium data were fit well by a Freundlich isotherm equation. Adsorption measurements show that the process is very fast. The adsorption data were modeled using first- and second-order kinetic equations and intra-particle diffusion models. It was found that the first-order kinetic equation could best describe the adsorption kinetics. The adsorption process was found to be complex and controlled by both surface and pore diffusion with surface diffusion at the earlier stages, followed by pore diffusion at the later stages. The thermodynamic parameters △G0, △S0 and △H0, have been calculated. The thermodynamics of the MB-ACF system indicate that the adsorption process is spontaneous.

  18. Adsorptional photocatalytic degradation of methylene blue onto pectin-CuS nanocomposite under solar light.

    Science.gov (United States)

    Gupta, Vinod Kumar; Pathania, Deepak; Agarwal, Shilpi; Singh, Pardeep

    2012-12-01

    This study describes the effect of adsorption on methylene blue degradation using pectin-CuS nanocomposite (PCSNC). The nanocomposite was synthesized using co-precipitation methods followed by direct encapsulation with pectin. The synthesized nanocomposite was characterized by SEM, TEM, XRD, FTIR and UV-vis spectral technique. The adsorption and photocatalytic efficiencies of PCSNC were compared with copper sulphide nanoparticle (CSNP). The dye removal was studied under different reaction conditions. The adsorption capacity of pectin based nanocomposite was higher due to other free functional group on pectin surface after connecting to nanoparticles. The simultaneous adsorption and photodegradation process (A+P) was the most efficient process due to rapid destruction of adsorbed dye molecules. The complete COD removal was attained in 10h using PCSNC/A+P process. On comparing with CSNP, pectin-CuS nano composite showed more degradation efficiency and reusability for MB degradation.

  19. Photocatalytic degradation of methylene blue with a nanocomposite system: synthesis, photocatalysis and degradation pathways.

    Science.gov (United States)

    Xia, Shengjie; Zhang, Lianyang; Pan, Guoxiang; Qian, Pingping; Ni, Zheming

    2015-02-21

    Three different composites, including a calcined FeOOH supported ZnAl layered double hydroxide (FeOOH-LDO), a calcined ZnAl layered double hydroxide (ZnAl-LDO) and a calcined ZnFeAl layered double hydroxide (ZnFeAl-LDO), were synthesized via a sol-gel method, and their activity for the visible light photocatalytic degradation of methylene blue (MB) was studied. The composites were characterized by PXRD, SEM, and BET techniques, confirming the formation of highly crystalline structures. The activity performance of MB degradation was in the following order: FeOOH-LDO (∼95%) > ZnFeAl-LDO (∼60%) > ZnAl-LDO (∼23%). In addition, a possible photocatalytic degradation reaction mechanism for MB was also proposed. Moreover, the frontier electron densities on the atoms of MB were calculated, which were in satisfactory agreement with the postulated mechanism.

  20. Graphene-SnO2 composites for highly efficient photocatalytic degradation of methylene blue under sunlight.

    Science.gov (United States)

    Seema, Humaira; Christian Kemp, K; Chandra, Vimlesh; Kim, Kwang S

    2012-09-07

    Graphene sheets decorated with SnO(2) nanoparticles (RGO-SnO(2)) were prepared via a redox reaction between graphene oxide (GO) and SnCl(2). Graphene oxide (GO) was reduced to graphene (RGO) and Sn(2+) was oxidized to SnO(2) during the redox reaction, leading to a homogeneous distribution of SnO(2) nanoparticles on RGO sheets. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show uniform distribution of the nanoparticles on the RGO surface and high-resolution transmission electron microscopy (HRTEM) shows an average particle size of 3-5 nm. The RGO-SnO(2) composite showed an enhanced photocatalytic degradation activity for the organic dye methylene blue under sunlight compared to bare SnO(2) nanoparticles. This result leads us to believe that the RGO-SnO(2) composite could be used in catalytic photodegradation of other organic dyes.

  1. Laser-induced silver nanoparticles on titanium oxide for photocatalytic degradation of methylene blue.

    Science.gov (United States)

    Whang, Thou-Jen; Huang, Hsien-Yu; Hsieh, Mu-Tao; Chen, Jyun-Jen

    2009-10-29

    Silver nanoparticles doped on titanium oxide (TiO(2)) were produced by laser-liquid interaction of silver nitrate (AgNO(3)) in isopropanol. Characteristics of Ag/TiO(2) (Ag doped TiO(2)) nanoparticles produced by the methods presented in this article were investigated by XRD, TEM, SEM, EDX, and UV-Vis. From the UV-Vis measurements, the absorption of visible light of the Ag/TiO(2) photocatalysts was improved (additional absorption at longer wavelength in visible light region) obviously. The photocatalytic efficiency of Ag/TiO(2) was tested by the degradation of methylene blue (MB) in aqueous solution. A maximum of 82.3% MB degradation is achieved by 2.0 wt% Ag/TiO(2) photocatalyst under 2 h illumination with a halogen lamp.

  2. Influence of activated carbon upon the photocatalytic degradation of methylene blue under UV-vis irradiation.

    Science.gov (United States)

    Matos, Juan; Montaña, Ricmary; Rivero, Eliram

    2015-01-01

    Photodegradation of methylene blue (MB) was studied on TiO2 in the presence of activated carbon (AC) prepared from the sawdust of a soft wood by physical activation under CO2 flow, by pyrolysis under N2 flow, and by chemical activation with ZnCl2 and H3PO4 under N2 flow. MB photodegradation was performed under UV and UV-visible irradiation to verify the scaling-up of the present TiO2-AC binary materials. It was verified that oxygenated surface groups on carbon were intrinsically photoactive, and a synergy effect between both solids has been estimated from the first-order apparent rate constants in the photodegradation of MB. This effect enhances the photoactivity of TiO2 up to a factor of about 9 under visible irradiation, and it was associated to the surface properties of AC.

  3. Catalytic degradation of methylene blue using biosynthesized gold and silver nanoparticles.

    Science.gov (United States)

    Suvith, V S; Philip, Daizy

    2014-01-24

    The scientific community is searching for new synthesis methods for the production of metallic nanoparticles. Green synthesis has now become a vast developing area of research. Here we report for the first time to best of our knowledge, a new green method for the synthesis of silver and gold nanoparticles using the Kashayam, Guggulutiktham, an ayurvedic medicine. This method is nontoxic and environmentally benign. The reduction and the stabilization capacity of the ayurvedic Kashayam are described in this paper. The size and shape of the silver and gold nanoparticles can be tuned by varying the quantity of the Kashayam. The synthesized nanoparticles are characterized using UV-VIS spectroscopy, TEM, XRD and FTIR. The size dependent catalytic activity of the synthesized nanoparticles is established in the reduction of Methylene Blue (MB) by NaBH4.

  4. Phenol and methylene blue photodegradation over Ti/SBA-15 materials under uv light

    Directory of Open Access Journals (Sweden)

    Olejnik Tomasz

    2016-09-01

    Full Text Available Ordered SBA-15 mesoporous silica supports have been synthesized and used for incorporation of titanium with different Ti/Si weight ratio via incipient wetness impregnation. Titanium tetraisopropoxide (TTIP was used as a source of Ti. Obtained catalysts were characterized to investigate the chemical framework and morphology by nitrogen sorption measurements, powder X-ray diffraction (XRD, X-ray fluorescence elemental analysis (XRF, transmission electron microscopy (TEM, UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS and Fourier transform infrared photoacoustic spectroscopy (FT-IR/PAS. The photocatalytic degradation of phenol and methylene blue water solutions were selected as a probe reactions to the photoactivity test of prepared samples and to verify the potential application of these materials for water purification. Experimental results indicate that the photocatalytic activity of Ti/Si mixed materials depends on the adsorption ability of composites and the photocatalytic activity of the titanium oxide.

  5. Laser-Induced Silver Nanoparticles on Titanium Oxide for Photocatalytic Degradation of Methylene Blue

    Directory of Open Access Journals (Sweden)

    Jyun-Jen Chen

    2009-10-01

    Full Text Available Silver nanoparticles doped on titanium oxide (TiO2 were produced by laser-liquid interaction of silver nitrate (AgNO3 in isopropanol. Characteristics of Ag/TiO2 (Ag doped TiO2 nanoparticles produced by the methods presented in this article were investigated by XRD, TEM, SEM, EDX, and UV-Vis. From the UV-Vis measurements, the absorption of visible light of the Ag/TiO2 photocatalysts was improved (additional absorption at longer wavelength in visible light region obviously. The photocatalytic efficiency of Ag/TiO2 was tested by the degradation of methylene blue (MB in aqueous solution. A maximum of 82.3% MB degradation is achieved by 2.0 wt% Ag/TiO2 photocatalyst under 2 h illumination with a halogen lamp.

  6. In vivo lymphatic targeting of methylene blue with microemulsion and multiple microemulsion.

    Science.gov (United States)

    Wang, Shujun; Yang, Rui; Yao, Huimin; Zhou, Guoqin; Zhang, Yinghui; Yang, Boyang; Ng, Lawrence; Yan, Macheng

    2009-10-01

    Three formulations including methylene blue solution (MB-S), MB water-in-oil microemulsion (MB-ME), and MB multiple microemulsion (MB-MME) were prepared with the aim to evaluate whether the three formulations can carry MB target to regional lymph nodes and show lymphatic tropism after subcutaneous administration. The pseudo-ternary phase diagrams were also studied. The morphology of MB-ME and MB-MME was examined by transmission electron microscopy to characterize the microstructure. The particle size and viscosity were also measured. MB concentrations in plasma, lymph nodes, and limb soles were quantitatively analyzed using HPLC. Results show that MME can target MB to regional lymph nodes, and can be employed as a potential lymph tracer in sentinel lymph node biopsy.

  7. Nanoengineering of methylene blue loaded silica encapsulated magnetite nanospheres and nanocapsules for photodynamic therapy

    Energy Technology Data Exchange (ETDEWEB)

    Andhariya, Nidhi [Bhavnagar University, Department of Physics (India); Chudasama, Bhupendra, E-mail: bnchudasama@gmail.com [Thapar University, School of Physics and Materials Science (India); Mehta, R. V. [Bhavnagar University, Department of Physics (India); Upadhyay, R. V. [Charotar University of Science and Technology, P.D. Patel Institute of Applied Sciences (India)

    2011-09-15

    Core-shell nanostructures have emerged as an important class of functional materials with potential applications in diverse fields, especially in health sciences. In this article, nanoengineering of novel magnetic colloidal dispersion containing surface modifiable silica with a core of single domain magnetite nanoparticles loaded with photosensitizer (PS) drug 'Methylene blue' (MB) has been described. Magnetite core is produced by the well-established chemical coprecipitation technique and silica shell is formed over it by the modified hydrolysis and condensation of TEOS (tetraethyl orthosilicate). Conditions for reaction kinetics have been established to tailor the core-shell structures in the form of nanospheres and nanocapsules. MB is loaded into the nanostructures by demethylation reaction. The major conclusion drawn from this study is that the synthesis route yields stable, non-aggregated MB loaded superparamagnetic magnetite-silica nanostructures with tailored morphology, tunable loading, and excellent magnetic properties.

  8. Methylene blue as an early diagnostic marker for oral precancer and cancer.

    Science.gov (United States)

    Riaz, Akhtar; Shreedhar, Balasundari; Kamboj, Mala; Natarajan, S

    2013-12-01

    Oral cancer is one of the most common neoplasm's and is ranked eighth in the cancer incidence worldwide. Early detection is of critical importance because survival rates markedly improve. In vivo staining is a simple, inexpensive, and fairly sensitive method. Involved 120 patients (50 with Premalignant Lesion, 50 with OSCC and 20 controls) stained by Methylene Blue (MB). The results of MB uptake were compared with a simultaneous biopsy of these lesions. Pathologically confirmed precancers and cancers were the positive targets of this screening, while hyperkeratosis without dysplasia and no evidence of malignancy were sorted as negative subjects of screening. The results revealed sensitivity of 91.4%, specificity of 66.6%, positive predictive value 97.7% and negative predictive value 33% leading to diagnostic accuracy of MB stain to 90%. We state that MB staining is useful diagnostic tool in community oral cancer screening programmes for high-risk individuals.

  9. Photocatalytic degradation for methylene blue using zinc oxide prepared by codeposition and sol-gel methods.

    Science.gov (United States)

    Shen, Wenzhong; Li, Zhijie; Wang, Hui; Liu, Yihong; Guo, Qingjie; Zhang, Yuanli

    2008-03-21

    Zinc oxide nanoparticle was obtained by zinc hydrate deposited on the silica nanoparticle surface and zinc hydrate was dispersed in starch gel. The structure of zinc oxide particle was characterized by nitrogen adsorption-desorption and XRD, the morphology was observed by TEM. The result showed that the zinc oxide nanoparticle deposited on the silica nanoparticle surface was well-dispersed and less than 50nm, displayed higher photocatalytic activity for methylene blue degradation. However, the zinc oxide nanoparticle in a size of 60nm was derived from starch gel and showed poorer photocatalytic activity. It provided a simple and effective route to prepare zinc oxide nanoparticle with higher photocatalytic activity through depositing zinc oxide on the silica particle surface, moreover, the catalyst is easier to recover due to its higher density.

  10. Contribution of Dissolved Oxygen to Methylene Blue Decomposition by Hybrid Advanced Oxidation Processes System

    Directory of Open Access Journals (Sweden)

    Heon Lee

    2012-01-01

    Full Text Available Experimental results of photocatalysis under high dissolved oxygen (DO concentration conditions are reported. Methylene blue was used as the organic pollutant to be degraded by a novel microwave/UV/DO/TiO2 photocatalyst hybrid system. The degradation rate increased with TiO2 nanoparticle dosages and DO concentration. However, inhibition of photocatalysis due to bubbles produced by DO generator was also observed. When the DO generator was used to increase the DO concentration in the pollutant solution treated by the microwave-assisted UV-TiO2 photocatalysis, the decomposition rate constant was highest among all the experimental conditions tested in this study. This result demonstrated that high concentration of DO can enhance the photocatalytic reaction rate by causing a synergistic effect of constituent techniques.

  11. Alkali treated Foumanat tea waste as an efficient adsorbent for methylene blue adsorption from aqueous solution

    Directory of Open Access Journals (Sweden)

    Azadeh Ebrahimian Pirbazari

    2014-08-01

    Full Text Available The adsorption of methylene blue (MB from aqueous solution by alkali treated Foumanat tea waste (ATFTW from agriculture biomass was investigated. The adsorbent was characterized by Scanning Electron Microscopy (SEM, Fourier Transform-Infrared Spectroscopy (FT-IR and nitrogen physisorption. FTIR results showed complexation and ion exchange appear to be the principle mechanism for MB adsorption. The adsorption isotherm data were fitted to Langmuir, Sips, Redlich-Peterson and Freundlich equations, and the Langmuir adsorption capacity, Qmax was found to be 461 mgg−1. It was found that the adsorption of MB increases by increasing temperature from 303 to 323 K and the process is endothermic in nature. The removal of MB by ATFTW followed pseudo-second order reaction kinetics based on Lagergren equations. Mechanism studies indicated that the adsorption of MB on the ATFTW was mainly governed by external mass transport where particle diffusion was the rate limiting step.

  12. Controlled release of encapsulated methylene blue in a multilayered textile coating

    Directory of Open Access Journals (Sweden)

    Martin Adeline

    2013-11-01

    Full Text Available We studied the formation of multilayered coating incorporating a β-cyclodextrin polyelectrolyte onto a pretreated polyethylene terephthalate (PET textile in order to obtain reservoir and sustained release properties towards bioactive molecules. This paper describes the alternate deposition by dip-coating onto the textile of chitosan (CHT and a β-cyclodextrin polyelectrolyte (polyCTR- βCD according to the layer-by-layer (LbL principle. Textiles covered with up to 12 layers were characterized by gravimetry, infrared, zetametry. The building of the multilayer system was then achieved including methylene blue (MB as bioactive model compound, complexed with polyCTR-βCD, and a release study of BM was investigated in batch. The results showed that the release profile of BM could be controlled by the number of layers in the system.

  13. Removal of methylene blue by adsorption onto activated carbon developed from Ficus carica bast

    Directory of Open Access Journals (Sweden)

    Deepak Pathania

    2017-02-01

    Full Text Available In this study, activated carbon was developed from Ficus carica bast (FCBAC. The experiments were carried out to explore methylene blue (MB uptake by FCBAC. The influence of various experimental factors such as contact time, initial dye concentration, adsorbent dosage, temperature and pH of dye solution was investigated. The adsorption equilibrium was represented with Langmuir, Freundlich and Temkin isotherm models. Langmuir and Tempkin equations were found to have the correlation coefficient value in good agreement. Adsorption of MB onto FCBAC followed pseudo second order kinetics. The calculated values of ΔH°, ΔS° and ΔG° were found to be 21.55 kJ/mol, 76.24 J/mol K and −1.55 kJ/mol, respectably. Adsorption process was spontaneous and endothermic in nature.

  14. Blood schizontocidal activity of methylene blue in combination with antimalarials against Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    Garavito G.

    2007-06-01

    Full Text Available Methylene blue (MB is the oldest synthetic antimalarial. It is not used anymore as antimalarial but should be reconsidered. For this purpose we have measured its impact on both chloroquine sensitive and resistant Plasmodium strains. We showed that around 5 nM of MB were able to inhibit 50% of the parasite growth in vitro and that late rings and early trophozoites were the most sensitive stages; while early rings, late trophozoites and schizonts were less sensitive. Drug interaction study following fractional inhibitory concentrations (FIC method showed antagonism with amodiaquine, atovaquone, doxycycline, pyrimethamine; additivity with artemether, chloroquine, mefloquine, primaquine and synergy with quinine. These results confirmed the interest of MB that could be integrated in a new low cost antimalarial combination therapy.

  15. Kinetics and mechanism of removal of methylene blue by adsorption onto perlite.

    Science.gov (United States)

    Doğan, Mehmet; Alkan, Mahir; Türkyilmaz, Aydin; Ozdemir, Yasemin

    2004-06-18

    The kinetics and mechanism of methylene blue adsorption on perlite have been studied. The effects of various experimental parameters, such as initial dye concentration, temperature and pH on the adsorption rate were investigated. Adsorption measurements show that the process is very fast and physical in nature. The extent of the dye removal increased with increase in the initial concentration of the dye and the initial pH and temperature of solution. Adsorption data were modelled using the first and second-order kinetic equations, mass transfer and intra-particle diffusion models. It was shown that the second-order kinetic equation could best describe the sorption kinetics. The diffusion coefficient, D, was found to increase when the initial dye concentration, pH and temperature were raised. Thermodynamic activation parameters, such as DeltaG*, DeltaS* and DeltaH*, were calculated.

  16. Orthophosphoric Acid Activated Babul Seed Carbon as an Adsorbent for the Removal of Methylene Blue

    Directory of Open Access Journals (Sweden)

    M. Sujatha

    2008-01-01

    Full Text Available An Experimental and theoretical study has been conducted on the adsorption of methylene blue dye using activated carbon prepared from babul seed by chemical activation with orthophosphoric acid. BET surface area of the activated carbon was determined as 1060 m2/g. Adsorption kinetics, equilibrium and thermodynamics were investigated as a function of initial dye concentration, temperature and pH. First order Lagergren, pseudo-second order and Elovich kinetic models were used to test the adsorption kinetics. Results were analyzed by the Langmuir, Freundlich and Temkin isotherm models. Based on regression coefficient, the equilibrium data found fitted well to the Langmuir equilibrium model than other models. The characteristics of the prepared activated carbon were found comparable to the commercial activated carbon. It is found that the babul seed activated carbon is very effective for the removal of colouring matter.

  17. Methylene blue photocatalysis in the presence of bismuth oxide under UV and solar light irradiation

    Directory of Open Access Journals (Sweden)

    Vanessa Rocha Liberatti

    2014-05-01

    Full Text Available Bismuth oxide (Bi2O3, an n-type semiconductor has been satisfactorily investigated for photocatalytic organic contaminant remediation. The Bi2O3 was prepared by solution combustion synthesis (SCS using as the oxidizing bismuth nitrate in acidic medium and urea as fuel. The influence of the type of synthesis on the photocatalytic properties of the oxide formed was investigated by XRD. From the diffractograms was verified that the materials obtained are predominantly of Bi2O3 crystals, it is possible to identify a sample with two crystalline phases, monoclinic (α-Bi2O3 and tetragonal (β-Bi2O3, and the other with only the monoclinic (α-Bi2O3. The two-phase oxide showed higher photocatalytic activity for discoloration of methylene blue under UV irradiation (60.59% and under sunlight (61.64% in 664 nm, followed kinetic law of pseudo-first order.

  18. Electrochemical behavior of hydrogen peroxide sensor based on new methylene blue as mediator

    Institute of Scientific and Technical Information of China (English)

    MA Jie; WU Hai; ZHU Yaqi

    2007-01-01

    A novel amperometric hydrogen peroxide sensor was proposed by co-immobilizing new methylene blue (NMB) and Horseradish peroxidase (HRP) on glassy carbon electrode through covalent binding.The electrochemical behavior of the sensor was studied extensively in 0.1 mol/L phosphate buffering solution (pH = 7.0).The experiments showed NMB could effectively transfer electrons between hydrogen peroxide and glassy carbon electrode.The electron transfer coefficient and apparent reaction rate constant were determined to be 0.861 and 1.27 s-1.The kinetic characteristics and responses of sensor on HzO2 were investigated.The Michaelis constant is 8.27 mol/L and the linear dependence of current on H2O2 is in the range of 2.5-100 μmol/L.At the same time,the effects of solution pH,buffer capacity,and temperature on the sensor were examined.

  19. Silver and gold nanocluster catalyzed reduction of methylene blue by arsine in micellar medium

    Indian Academy of Sciences (India)

    Subrata Kundu; Sujit Kumar Ghosh; Madhuri Mandal; Tarasankar Pal

    2002-11-01

    Arsenic can be determined in parts-per-million (ppm) level by absorbance measurement. This method is based on the quantitative colour bleaching of the dye, methylene blue by arsine catalyzed by nanoparticles in micellar medium. The arsine has been generated in situ from sodium arsenate by NaBH4 reduction. The absorbance measurement was carried out at the max of the dye at 660 nm. The calibration graph set-up for three linear dynamic ranges (LDR) are 0–8.63 ppm, 0–1.11 ppm and 0–0.11 ppm and limit of detections (LODs) are 1.3, 0.53 and 0.03 ppm, respectively. This method is simple, sensitive and easy to carry out. It is free from phosphate and silicate interference and applicable to real sample analysis.

  20. Filtering absorption and visual detection of methylene blue by nitrated cellulose acetate membrane

    Energy Technology Data Exchange (ETDEWEB)

    He, Shengbin; Fang, He; Xu, Xiaoping [College of Chemistry, Fuzhou University, Fuzhou (China)

    2016-04-15

    Wastewater-containing industrial dyes are quite harmful since most dyes are stable and toxic to humans. Detection and removing of those dyes from wastewater is necessary to ensure water supply safety. In present work, a nitrated cellulose acetate (NCA) microfiltration membrane was developed for specific absorption and visible detection of methylene blue (MB). The NCA microfiltration membrane overcomes the defect of high driven pressure in nanofiltration or ultrafiltration process. By absorption effect, the NCA membrane also overcomes the defect of low retention rate of traditional microfiltration membrane to dyes. The residual MB can be removed quickly and thoroughly by microfiltration absorption. The microfiltration membrane can also be used for visual detection of MB by concentrating the MB on membrane. The limit of detection is as low as 0.001 mg/L. The detection method is simple and free of large-scale instrument, and can be used as a portable device for spot detection of dye-contaminated water.

  1. The in vivo antimalarial activity of methylene blue combined with pyrimethamine, chloroquine and quinine

    Directory of Open Access Journals (Sweden)

    Giovanny Garavito

    2012-09-01

    Full Text Available The effectiveness of methylene blue (MB combined with pyrimethamine (PYR, chloroquine (CQ or quinine (Q was examined in a classical four-day suppressive test against a causative agent of rodent malaria, Plasmodium berghei. A marked potentiation was observed when MB was administered at a non-curative dose of 15 mg/kg/day in combination with PYR (0.19 mg/kg/day or Q (25 mg/kg/day. No synergy was found between MB (15 mg/Kg and CQ (0.75 mg/Kg. Our results suggest that the combination of MB with PYR or Q may improve the efficacy of these currently used antimalarial drugs.

  2. Catalytic ozone aqueous decomposition of methylene blue using composite metal oxides

    Science.gov (United States)

    Liu, Xuan; Hou, Yongjiang; Guo, Jie; Wang, Yaquan; Zuo, Qian; Wang, Chunyu

    2015-07-01

    By using the method of co-precipitation, Fe-Mn, Al-Mn, Al-Mg composite metal oxides were prepared. Using X-ray diffractometer(XRD), the phases of catalysts synthesized were observed to be Mn3O4 and Fe2O3. With the increase of the calcination temperature, Mn3O4 was gradually transformed into Mn2O3. The experimental results show that: the best catalyst is the Fe-Mn composite metal oxide with the calcination temperature of 650 °C. In this experimental condition, when the ozone amount was 1.92mg/min, and the dosage of catalyst was 0.5g, the removal rate of methylene blue (MB) was the best. The decolorization rate can reach to 100%. Compared with the effect of ozonation alone, the total organic carbon removal rate increased from 29.19% up to 65.78% after adding catalysts.

  3. Ultrasound-guided percutaneous injection of methylene blue to identify nerve pathology and guide surgery.

    Science.gov (United States)

    Osorio, Joseph A; Breshears, Jonathan D; Arnaout, Omar; Simon, Neil G; Hastings-Robinson, Ashley M; Aleshi, Pedram; Kliot, Michel

    2015-09-01

    OBJECT The objective of this study was to provide a technique that could be used in the preoperative period to facilitate the surgical exploration of peripheral nerve pathology. METHODS The authors describe a technique in which 1) ultrasonography is used in the immediate preoperative period to identify target peripheral nerves, 2) an ultrasound-guided needle electrode is used to stimulate peripheral nerves to confirm their position, and then 3) a methylene blue (MB) injection is performed to mark the peripheral nerve pathology to facilitate surgical exploration. RESULTS A cohort of 13 patients with varying indications for peripheral nerve surgery is presented in which ultrasound guidance, stimulation, and MB were used to localize and create a road map for surgeries. CONCLUSIONS Preoperative ultrasound-guided MB administration is a promising technique that peripheral nerve surgeons could use to plan and execute surgery.

  4. LED-activated methylene blue-loaded Pluronic-nanogold hybrids for in vitro photodynamic therapy.

    Science.gov (United States)

    Simon, Timea; Boca-Farcau, Sanda; Gabudean, Ana-Maria; Baldeck, Patrice; Astilean, Simion

    2013-12-01

    In this work we introduce a new class of multifunctional photodynamic agents based on the coupling of photosensitizer molecules with noble metal nanoparticles, which can be efficiently activated under low light intensity. The favourable modification of the photophysical properties of methylene blue (MB) in MB-loaded Pluronic-nanogold hybrids (Au-PF127-MB) increases the probability of singlet oxygen generation, which in turn allows the use of a light emitting diode (LED) irradiation source instead of commonly used, more invasive lasers. In this regard, Au-PF127-MB treated human lung carcinoma cells (HTB 177) were irradiated at different light doses, using a 660 nm LED source, the results indicating a dose dependent therapeutic effect, decreasing the cell viability down to 13%. Owing to their effectiveness, biocompatibility and integrated imaging and therapeutic functionalities, Au-PF127-MB could represent an important development in the field of biophotonic applications.

  5. Wet chemical method for synthesizing 3D graphene/gold nanocomposite: catalytic reduction of methylene blue

    Science.gov (United States)

    Xie, Jiliang; Yang, Xujie; Xu, Xingyou

    2017-04-01

    In this paper, a simple and environmentally-friendly approach was reported to synthesize a novel 3D composite of graphene/gold nanoparticles (3DG/Au NPs) in one step. A 3D interlaced framework of graphene, which exhibited hierarchically porous structures, generated directly through the distinct driving force during the hydrothermal growth. Meanwhile, Au NPs with high dispersity, which displayed tunable morphologies, were immobilized on the framework, where the as-prepared graphene was employed as the endogenous reducing agent. Compared with AuNPs, the obtained 3DG/Au NPs exhibited remarkably convenient recyclability and high activity for the reduction of methylene blue which is a kind of organic dye.

  6. Spectroscopic Studies of the Interaction of Silver Nanoparticles with Methylene Blue

    Institute of Scientific and Technical Information of China (English)

    Chuan DONG; Jun ZHANG; Dai-zi ZHOU

    2010-01-01

    The interaction between silver nanoparticles and Methylene Blue(MB)is studied by UV-Vis spectroscopy and fluorescence spectrometry.The UN-Vis absorption of the silver nanoparticles dramatically with the addition of MB.However,no obvious changes of absorption spectra of MB are observed when silver colloids ate added into the MB solution.In the presence of surfactant SDS,the catalysis of the silver nanoparticles in the reducton of MB by sodium borohydride is exhibited by UV-Vis and fluorescence spectroscopy of MB displaying faster response compared with the absence of the silver nanoparticles.The results show that the activity of surfactant SDS modified silver nanoparticles is great and a strong physical adsorption to MB exists.

  7. Comparison effects and dielectric properties of different dose methylene-blue-doped hydrogels.

    Science.gov (United States)

    Yalçın, O; Coşkun, R; Okutan, M; Öztürk, M

    2013-08-01

    The dielectric properties of methylene blue (MB)-doped hydrogels were investigated by impedance spectroscopy. The real part (ε') and the imaginary part (ε") of the complex dielectric constant and the energy loss tangent/dissipation factor (tan δ) were measured in the frequency range of 10 Hz to 100 MHz at room temperature for pH 5.5 value. Frequency variations of the resistance, the reactance, and the impedance of the samples have also been investigated. The dielectric permittivity of the MB-doped hydrogels is sensitive to ionic conduction and electrode polarization in low frequency. Furthermore, the dielectric behavior in high-frequency parts was attributed to the Brownian motion of the hydrogen bonds. The ionic conduction for MB-doped samples was prevented for Cole-Cole plots, while the Cole-Cole plots for pure sample show equivalent electrical circuit. The alternative current (ac) conductivity increases with the increasing MB concentration and the frequency.

  8. SYNTHESIS AND POLYMERIZATION OF 2-OXO-3-METHYLENE-5,6-DIPHENYL-1,4-DIOXAN

    Institute of Scientific and Technical Information of China (English)

    FENG Pinzhen; LU Jiantao

    1994-01-01

    A new cyclic monomer, 2-oxo-3-methylene-5, 6-diphenyl-1,4-dioxan, was synthesized. The structure of the intermediates and the monomer were determined by IR,1H NMR,13C NMR and elemental analysis. This new monomer is different from other cyclic monomers in this series,it is a solid (mp 108-109℃)and not very reactive,but still can undergo free radical ring-opening polymerization. The free radical polymerization was carried out at 130℃. The structure of the resulting polymer was discussed and charaterized by IR, 1H NMR, 13C NMR and elemental analysis. The molecular weight of the polymer was estimated by viscosity determination.

  9. Novel silicone-based polymer containing active methylene designed for the removal of indoor formaldehyde

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Song, E-mail: niusong84@163.com; Yan, Hongxia, E-mail: hongxiayan@nwpu.edu.cn

    2015-04-28

    Highlights: • A novel silicone-based polymer with active methylene was explored. • Surface tension of liquid paints could be lowered using the polymer. • The polymer was easy to migrate toward the air-coating interface. • Free HCHO could effectively be removed using the polymer. • A lights on HCHO reduction without complicated preparation procedure was shielded. - Abstract: Indoor air pollution is caused inevitably due to complicated home decoration, in which formaldehyde is one of the most typical pollutants. It will be a convenient, economical and effective strategy to remove indoor formaldehyde if imparting a feature of formaldehyde removal to decorative coatings. We have successfully explored a novel silicone-based polymer containing active methylene used as a formaldehyde absorbent in coatings via a straightforward transesterification process using inexpensive and easily available chemicals. The polymer has been characterized by {sup 13}C NMR, FTIR, GC and GPC. Formaldehyde removal capacity of the coating films containing different contents of the polymer has been investigated. The results indicated that coatings incorporating 4 wt% of the polymer could make the coating films exhibit significant improvement on formaldehyde removal including purificatory performance (>85%) and durability of purificatory effect (>60%), compared to those consisting of absorbents without any silicon, and improve yellowing resistance performance, while other properties, such as gloss, adhesion, pencil hardness, flexibility and impact resistance, were kept almost unaffected. The chemical absorption process of the silicone-based polymer filled in interior decorative coatings is demonstrated as a promising technology to purify indoor formaldehyde and thus can reduce the harm to individuals.

  10. Ultra-efficient photocatalytic deprivation of methylene blue and biological activities of biogenic silver nanoparticles.

    Science.gov (United States)

    Khan, Arif Ullah; Yuan, Qipeng; Wei, Yun; Khan, Zia Ul Haq; Tahir, Kamran; Khan, Shahab Ullah; Ahmad, Aftab; Khan, Shafiullah; Nazir, Sadia; Khan, Faheem Ullah

    2016-06-01

    Phytosynthesis of metal nanoparticles is considered as a safe, cost-effective, and green approach. In this study, silver nanoparticles (AgNPs) were successfully synthesized using the aqueous extract of Lychee (Litchi chinensis) fruit peel and an aqueous solution of silver nitrate (AgNO3). The synthesized nanoparticles were characterized by several analytical techniques i.e. UV-Vis Spectroscopy, XRD (X-ray diffraction spectroscopy), EDX (electron dispersive X-ray), SAED (selected area electron diffraction), HRTEM (high-resolution transmission electron microscopy), and FTIR (Fourier transform infrared spectroscopy). HRTEM and XRD results indicated that the prepared AgNPs are spherical in shape, well dispersed and face centered cubic crystalline. AgNPs showed potent antibacterial properties against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The minimum inhibitory concentration (MIC) values were 125μg against E. coli and 62.5μg against both S. aureus and B. subtilis. AgNPs induce efficient cell constituent release from bacterial cells, which indicates the deterioration of cytoplasmic membrane. Moreover, antioxidant studies on the as-synthesized nanoparticles reveal efficient scavenging of the stable or harmful DPPH free radical. The cytotoxicity assay confirmed that biosynthesized AgNPs are nontoxic to normal healthy RBCs. AgNPs exhibited consistent release of Ag(+) determined by ICP-AES analysis. AgNPs exhibited extraordinary photocatalytic degradation (99.24%) of methylene blue. On the other hand, commercial silver nanoparticles have moderate biological activities against the tested bacterial strains and negligible photocatalytic degradation of methylene blue. The significant biological and photocatalytic activities of the biosynthesized silver nanoparticles are attributed to their small size, spherical morphology and high dispersion.

  11. Isolation of methylene dianiline and aqueous-soluble biodegradation products from polycarbonate-polyurethanes.

    Science.gov (United States)

    Tang, Y W; Labow, R S; Santerre, J P

    2003-08-01

    Polycarbonate-polyurethanes (PCNUs) have provided the medical device industry with practical alternatives to oxidation-sensitive polyether-urethanes (PEUs). To date, many studies have focused on PCNUs synthesized with 4,4'-methylene diphenyl-diisocyanate (MDI). The relative hydrolytic stability of this class of polyurethanes is actually quite surprising given the inherent hydrolytic potential of the aliphatic carbonate group. Yet, there has been little information reporting on the rationale for the material's demonstrated hydrolytic stability. Recent work has shown that PCNU materials have a strong sensitivity towards hydrolysis when changes are made to their hard segment content and/or chemistry. However, knowledge is specifically lacking in regards of the identification of cleavage sites and the specific nature of the biodegradation products. Using high-performance liquid chromatography, radiolabel tracers and mass spectrometry, the current study provides insight into the distribution of biodegradation products from the enzyme-catalyzed hydrolysis of five different PCNUs. The hydrolytic sensitivity of the materials is shown to be related to the distribution of products, which itself is a direct consequence of unique micro-structures formed within the different materials. While an MDI-based polymer was shown to be the most hydrolytically stable material, it was the only PCNU that produced its diamine analog, in this case 4,4'-methylene dianiline (MDA), as a degradation product. Given the concern over aromatic diamine toxicity, this finding is important and highlights the fact that relative biostability is a distinct issue from that of degradation product toxicity, and that both must be considered separately when assessing the impact of biodegradation on biomaterial in vivo compatibility.

  12. Pyrite-enhanced methylene blue degradation in non-thermal plasma water treatment reactor

    Energy Technology Data Exchange (ETDEWEB)

    Benetoli, Luis Otavio de Brito, E-mail: luskywalcker@yahoo.com.br [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Cadorin, Bruno Mena; Baldissarelli, Vanessa Zanon [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Geremias, Reginaldo [Departamento de Ciencias Rurais, Universidade Federal de Santa Catarina (UFSC), Curitibanos, SC (Brazil); Goncalvez de Souza, Ivan [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Debacher, Nito Angelo, E-mail: debacher@qmc.ufsc.br [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2012-10-30

    Highlights: Black-Right-Pointing-Pointer We use O{sub 2} as the feed gas and pyrite was added to the non-thermal plasma reactor. Black-Right-Pointing-Pointer The methylene blue removal by NTP increased in the presence of pyrite. Black-Right-Pointing-Pointer The total organic carbon content decreased substantially. Black-Right-Pointing-Pointer The acute toxicity test showed that the treated solution is not toxic. Black-Right-Pointing-Pointer The dye degradation occurs via electron impact as well as successive hydroxylation. - Abstract: In this study, methylene blue (MB) removal from an aqueous phase by electrical discharge non-thermal plasma (NTP) over water was investigated using three different feed gases: N{sub 2}, Ar, and O{sub 2}. The results showed that the dye removal rate was not strongly dependent on the feed gas when the electrical current was kept the same for all gases. The hydrogen peroxide generation in the water varied according to the feed gas (N{sub 2} < Ar < O{sub 2}). Using O{sub 2} as the feed gas, pyrite was added to the reactor in acid medium resulting in an accentuated increase in the dye removal, which suggests that pyrite acts as a Fenton-like catalyst. The total organic carbon (TOC) content of the dye solution decreased slightly as the plasma treatment time increased, but in the presence of the pyrite catalyst the TOC removal increased substantially. The acute toxicity test using Artemia sp. microcrustaceans showed that the treated solution is not toxic when Ar, O{sub 2} or O{sub 2}-pyrite is employed. Electrospray ionization mass spectrometry analysis (ESI-MS) of the treated samples indicated that the dye degradation occurs via high energy electron impact as well as successive hydroxylation in the benzene rings of the dye molecules.

  13. Fixed-bed adsorption study of methylene blue onto pyrolytic tire char

    Science.gov (United States)

    Makrigianni, Vassiliki; Giannakas, Aris; Papadaki, Maria; Albanis, Triantafyllos; Konstantinou, Ioannis

    2016-04-01

    In this work, the adsorption efficiency of acid treated pyrolytic tire char to cationic methylene blue (MB) dye adsorption from aqueous solutions was investigated by fixed-bed adsorption column experiments. The effects of the initial dye concentration (10 - 40 mg L-1) and feed flow rate (50 - 150 mL min -1) with a fixed bed height (15 cm) were studied in order to determine the breakthrough characteristics of the adsorption system. The Adams-Bohart, Yoon-Nelson and Thomas model were applied to the adsorption of MB onto char at different operational conditions to predict the breakthrough curves and to determine the characteristic parameters of the column. The results showed that the maximum adsorbed quantities decreased with increasing flow rate and increased with increasing initial MB concentration. Breakthrough time and exhaustion time increased with decreasing inlet dye concentration and flow rate. In contrast with Adams-Bohart model, Yoon-Nelson model followed by Thomas model were found more suitable to describe the fixed-bed adsorption of methylene blue by char. The correlation coefficient values R2 for both models at different operating conditions are higher than 0.9 and the low average relative error values provided very good fittings of experimental data at different operating conditions. Higher adsorption capacity of 3.85 mg g -1 was obtained at 15 cm of adsorbent bed height, flow rate of 100 mL min -1and initial MB concentration of 40 mg L-1. Although that activated carbons exhibited higher adsorption capacities in the literature, acid-treated pyrolytic tire char was found to be considerably efficient adsorbent for the removal of MB dye column taking into account the advantages of the simpler production process compared to activated carbons, as well as, the availability of waste tire feedstock and concurrent waste tire management.

  14. Kinetic and Thermodynamics of Methylene Blue Adsorption onto Zero Valent Iron Supported on Mesoporous Silica

    Directory of Open Access Journals (Sweden)

    Atyaf Khalid Hameed

    2016-08-01

    Full Text Available Zero valent iron supported on mesoporous silicanano particles (NZVI/MSNs was prepared by the aqueous phase borohydride reduction methods. Prior to the reduction, mesoporous silica nanoparticles (MSNs were prepared through the activation of fumed silica with concentrated HCl by refluxing at 90 °C. FTIR, XRD, FESEM, EDX and BET were used to characterize theadsorbents prepared. BET surface areas of MSNs, NZVI, and NZVI/MSNs were 126, 41, and 72 m2/g for, respectively. The performance of NZVI/MSNs as adsorbent was examined by adsorption of methylene blue (MB, performed in series of batch experiments. In the kinetic studies, pseudo first order and pseudo second order kinetic models were examined. The pseudo second order equation provided the best fit with the experimental data. Thermodynamic studies indicated that the adsorption process is endothermic with ΔH° was 90.53 kJ/mol. Positive ΔS° (300 J/mol and negative ΔG° (-6.42 kJ/mol was recorded, indicating the spontaneous of the adsorption process and naturally favorable. Copyright © 2016 BCREC GROUP. All rights reserved Received: 5th March 2016; Revised: 18th March 2016; Accepted: 18th March 2016 How to Cite: Hameed, A.K., Dewayanto, N., Dongyun, D., Nordin, M.R., Mohd Hasbi Ab. Rahim, M.H.A. (2016. Kinetic and Thermodynamics of Methylene Blue Adsorption onto Zero Valent Iron Supported on Mesoporous Silica. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (2: 250-261 (doi:10.9767/bcrec.11.2.443.250-261 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.2.443.250-261

  15. Experimental and kinetic studies on methylene blue adsorption by coir pith carbon.

    Science.gov (United States)

    Kavitha, D; Namasivayam, C

    2007-01-01

    Varying the parameters such as agitation time, dye concentration, adsorbent dose, pH and temperature carried out the potential feasibility of thermally activated coir pith carbon prepared from coconut husk for removal of methylene blue. Greater percentage of dye was removed with decrease in the initial concentration of dye and increase in amount of adsorbent used. Kinetic study showed that the adsorption of dye on coir pith carbon was a gradual process. Lagergren first-order, second-order, intra particle diffusion model and Bangham were used to fit the experimental data. Equilibrium isotherms were analysed by Langmuir, Freundlich, Dubnin-Radushkevich, and Tempkin isotherm. The adsorption capacity was found to be 5.87 mg/g by Langmuir isotherm for the particle size 250-500 microm. The equilibrium time was found to be 30 and 60 min for 10 and 20 mg/L and 100 min for 30, 40 mg/L dye concentrations, respectively. A maximum removal of 97% was obtained at natural pH 6.9 for an adsorbent dose of 100 mg/50 mL and 100% removal was obtained for an adsorbent dose of 600 mg/50 mL of 10 mg/L dye concentration. The pH effect and desorption studies suggest that chemisorption might be the major mode of the adsorption process. The change in entropy (DeltaS0) and heat of adsorption (DeltaH0) of coir pith carbon was estimated as 117.20 J/mol/K and 30.88 kJ/mol, respectively. The high negative value of change in Gibbs free energy indicates the feasible and spontaneous adsorption of methylene blue on coir pith carbon.

  16. Localizating and Extracting Small Peripheral Nodules of Lung with Simulating 
Radiaotherapy Combining Methylene Blue Staining

    Directory of Open Access Journals (Sweden)

    Feng MAO

    2016-09-01

    Full Text Available Background and objective With the extensively application of HRCT (high resolution CT and the popularization of early lung cancer screening, the proportion of small nodullar lung cancer to be operated increases rapidly. Identifying the focus lesions quickly and accurately in operation has shown to be a challenge. We carried out this research trying to make use of and evaluate a new method that localizaes and extracts small peripheral pulmonary nodules by way of simulating radiaotherapy combining methylene blue staining. Methods From February 2012 to January 2015, 97 patients with 100 peripheral pulmonary nodules ≤10 mm in size were simulated puncturing using a radiotherapy planning. When the anaesthesia came into use, methylene blue dye was injected to the virtually identified point corresponding to the surface point, according to the angle and depth previously computed by the radiotherapy planning. The video-assisted thoracoscopic surgery (VATS wedge resections of the marked lesions were undertaken and the specimens were sent for frozen pathologic examination. The interval time from anesthesia-completing to puncture and injection, The interval time from methylene blue injection to identifying the stained area and the distances between the centre point of the stains and edge of coloured lesion were recorded. Results Our preoperative localization procedure was successful in 96 of 100 (96% nodules. The interval time from anesthesia-completing to puncture and injection of methylene blue were (4.85±1.25 min. The interval time from methylene blue injection to identifying the stained area was (16.36±2.36 min. The distances between the centre point of the stains and edge of coloured lesion were (4.78±2.51 mm. No complication was observed in all participants. Conclusion The new method of locating peripheral pulmonary nodules by simulating simulating radiaotherapy combining methylene blue staining has a high success rate and no complication for

  17. Color measurement of methylene blue dye/clay mixtures and its application using economical methods

    Science.gov (United States)

    Milosevic, Maja; Kaludjerovic, Lazar; Logar, Mihovil

    2016-04-01

    Identifying the clay mineral components of clay materials by staining tests is rapid and simple, but their applicability is restricted because of the mutual interference of the common components of clay materials and difficulties in color determination. The change of color with concentration of the dye is related to the use of colorants as a field test for identifying clay minerals and has been improved over the years to assure the accuracy of the tests (Faust G. T., 1940). The problem of measurement and standardization of color may be solved by combination of colors observed in staining tests with prepared charts of color chips available in the Munsell Book of Color, published by Munsell Color Co. Under a particular set of illumination conditions, a human eye can achieve an approximate match between the color of the dyed clay sample and that of a standard color chip, even though they do have different spectral reflectance characteristics. Experiments were carried out with diffuse reflectance spectroscopy on selected clay samples (three montmorillonite, three kaolinite and one mix-layer clay samples) saturated with different concentration of methylene blue dye solution. Dominant wavelength and purity of the color was obtained on oriented dry samples and calculated by use of the I. C. I. (x, y) - diagram in the region of 400-700 nm (reflectance spectra) without MB and after saturation with different concentrations of MB solutions. Samples were carefully photographed in the natural light environment and processed with user friendly and easily accessible applications (Adobe color CC and ColorHexa encyclopedia) available for android phones or tablets. Obtained colors were compared with Munsell standard color chips, RGB and Hexa color standards. Changes in the color of clay samples in their interaction with different concentration of the applied dye together with application of economical methods can still be used as a rapid fieldwork test. Different types of clay

  18. The interactions of azure B, a metabolite of methylene blue, with acetylcholinesterase and butyrylcholinesterase

    Energy Technology Data Exchange (ETDEWEB)

    Petzer, Anél, E-mail: 12264954@nwu.ac.za [Centre of Excellence for Pharmaceutical Sciences, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Harvey, Brian H. [Centre of Excellence for Pharmaceutical Sciences, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Petzer, Jacobus P. [Division of Pharmaceutical Chemistry, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa)

    2014-02-01

    Methylene blue (MB) is reported to possess diverse pharmacological actions and is attracting increasing attention for the treatment of neurodegenerative disorders such as Alzheimer's disease. Among the pharmacological actions of MB, is the significant inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). These activities may, at least in part, underlie MB's beneficial effects in Alzheimer's disease. MB is metabolized to yield N-demethylated products of which azure B, the monodemethyl metabolite, is the predominant species. Azure B has been shown to be pharmacologically active and also possesses a variety of biological actions. Azure B therefore may contribute to the pharmacological profile of MB. Based on these considerations, the present study investigates the possibility that azure B may, similar to MB, act as an inhibitor of human AChE and BuChE. The results document that azure B inhibits AChE and BuChE with IC{sub 50} values of 0.486 μM and 1.99 μM, respectively. The results further show that azure B inhibits AChE and BuChE reversibly, and that the modes of inhibition are most likely competitive. Although the AChE and BuChE inhibitory activities of azure B are twofold and fivefold, respectively, less potent than those recorded for MB [IC{sub 50}(AChE) = 0.214 μM; IC{sub 50}(BuChE) = 0.389 μM] under identical conditions, azure B may be a contributor to MB's in vivo activation of the cholinergic system and beneficial effects in Alzheimer's disease. - Highlights: • Methylene blue (MB) is a known inhibitor of AChE and BuChE. • Azure B, the major metabolite of MB, also is an inhibitor of AChE and BuChE. • Azure B may be a contributor to MB's in vivo activation of the cholinergic system. • Azure B may contribute to MB's potential in Alzheimer's disease therapy.

  19. Photocatalytic degradation of methylene blue over nanosized TiO2 particles prepared using the self-propagating high-temperature synthesis method.

    Science.gov (United States)

    Park, Chul-Min; Seo, Hyeong-Seok; Cho, Jung-Ho; Choi, Da-Hye; Jeong, Young-Shin; Chung, Min-Chul; Jung, Sang-Chul; Jeong, Woon-Jo; Ban, Jae-Sam; Ahn, Ho-Geun

    2013-08-01

    In order to reutilize the spent metallic titanium chips, TiO2 photocatalysts were prepared using the self-propagating high-temperature synthesis (SHS) method, and were characterized by N2 gas adsorption, X-ray diffraction, and scanning electron microscope, particle size distribution. Also, their photocatalytic activities were evaluated using methylene blue as a model organic compound. It was confirmed that the crystal structure of TiO2 prepared by SHS method was relatively homogeneous powder of rutile type. Optimum conditions for photocatalytic degradation of methylene blue under UV-C irradiation were methylene blue 9.5 ppm in solution and at amount of TiO2 added of 0.02 g/L. In addition, it was found that the photocatalytic activity for methylene blue degradation over the prepared TiO2 particles was positively related with BET specific surface area.

  20. Value of endoscopic methylene blue and Lugol's iodine double staining and detection of GST-Π and telomerase in the early diagnosis of esophageal carcinoma

    OpenAIRE

    Zhu, Xuan; Zhang, Shuang-Hong; ZHANG, KUN-HE; Li, Bi-Ming; Chen, Jiang

    2005-01-01

    AIM: To explore the expressions of GST-Π and telomerase activity in esophageal carcinoma and premalignant lesions and to investigate the value of endoscopic methylene blue (MB) and Lugol's iodine double staining.

  1. Simultaneous adsorption of methyl red and methylene blue onto biochar and an equilibrium modeling at high concentration.

    Science.gov (United States)

    Ding, Guanyu; Wang, Buyun; Chen, Lingyu; Zhao, Shuangjiao

    2016-11-01

    Methyl red, methylene blue and biochar were used to investigate simultaneous adsorption of dyes onto low-cost adsorbent at different concentrations combinations. Langmuir mixed model could describe the adsorption well at low concentrations. However, it could not describe the adsorption anymore when concentrations of methyl red and methylene blue were higher than 255 and 300 mg L(-1) respectively with 0.5 g L(-1) biochar loading. A new model on the interaction among adsorbed adsorbates at equilibrium was developed. It could describe the adsorption at high concentrations well. According to the experimental results, interaction among dyes molecules would replace the competition onto adsorbent to be the main factor influencing adsorption when amount of adsorbed adsorbates were higher than those required to form a monolayer on all the adsorbing sites of adsorbent. The model was further verified by adsorption with other solute such as glucose or NaCl in solution.

  2. Microstructure and Photocatalytic Decomposition of Methylene Blue by TiO2-Mounted Halloysite, a Natural Tubular Mineral

    Institute of Scientific and Technical Information of China (English)

    LU Xianchu; CHUAN Xiuyun; WANG Aiping; KANG Feiyu

    2006-01-01

    On the basis of analysis of structure and properties, halloysite, a natural tubular mineral,was developed for an environmental treatment. TiO2 was mounted into halloysite by using hydrolysis of tetrabutyl titanate at room temperature. The adsorption and photocatalytic performance of halloysite and TiO2-mounted halloysite have been examined in methylene blue aqueous solution in the dark and under ultraviolet ray irradiation, respectively. Their performance of adsorption and photodecomposition was evaluated from the adsorbed and degraded amounts of methylene blue (MB).Due to the mixture of adsorption and photodecomposition, the concentration of MB, organic pollution,in water decreased rapidly with TiO2-mounted halloysite powder, which is a faster reaction than that with halloysite-only adsorption. This new use of halloysite is leading to many interesting applications in the decomposition and elimination of various pollutants in air and water.

  3. Sonocatalytic Methylene Blue in The Presence of Fe3O4-CuO-TiO2 Nanocomposites Heterostructure

    Science.gov (United States)

    Fauzian, Malleo; Jalaludin, Shofianina; Taufik, Ardiansyah; Saleh, Rosari

    2016-04-01

    In this work, the emphasis was mainly placed on investigating the sonocatalytic activity of Fe3O4-CuO-TiO2 nanocomposites heterostructure. The prepared samples were characterized by X-ray diffraction (XRD), Vibrating Sample Magnetometer (VSM), Brunauer-Emmett-Teller (BET) Surface Area Analysis. Methylene blue dye was selected to examine the sonocatalytic activity of Fe3O4-CuO-TiO2 nanocomposites heterostructure. The degradation reaction processes were monitored by UV-vis spectrophotometer. The influence on the activity of the Fe3O4-CuO-TiO2 nanocomposites heterostructure such as TiO2 loading was studied. The sonocatalyst Fe3O4-CuO-TiO2 with molar ratio of 1:1:5 showed the highest sonocatalytic activity. At last, the experiment also indicated that holes are the main reactive species in the photodegradation mechanism in methylene blue.

  4. Methylene blue, midodrine, and pseudoephedrine: a review of alternative agents for refractory hypotension in the intensive care unit.

    Science.gov (United States)

    Van Berkel, Megan A; Fuller, Laura A; Alexandrov, Anne W; Jones, G Morgan

    2015-01-01

    Hypotensive episodes are common among patients in the intensive care unit and can lead to multiorgan failure if uncontrolled. Fluid administration and continuous infusion of vasoactive agents are frequently used for management of hypotension; however, both therapies may be associated with adverse effects including pulmonary edema and tissue necrosis. In addition, availability of these first-line agents has been impacted by the increasing occurrence of drug shortages. Methylene blue, pseudoephedrine, and midodrine have been considered potential alternatives to standard therapy. These agents may not only be used when first-line agents are unavailable due to shortages, but they may also aid in reducing the cumulative dose of other vasoactive agents used. The purpose of this review was to discuss strategies for the safe and effective use of methylene blue, pseudoephedrine, and midodrine for the treatment of hypotension in the critically ill.

  5. 亚甲基修饰杯芳烃%Brief Introduction of Functionalized Calixarenes on Methylene Bridge

    Institute of Scientific and Technical Information of China (English)

    董慧民; 郑浩; 冶保献

    2005-01-01

      从三方面介绍了杯芳烃亚甲基修饰的研究概况,主要有引入杂原子、取代亚甲基的氢和亚甲基存在不饱和键等形式。这些修饰改变了杯芳烃的构象等性质,扩展了杯芳烃的分子、离子识别等功能。%  The functionalization of methylene group of calixarenes is introduced briefly. The introduction of heteroatoms as bridging atoms, the substitution of hydrogen atom, and unsaturated bond on the methylene bridge of calixarenes would offer additional opportunities to modify their properties, affinity and selectivity for binding ions or molecules.

  6. Myoclonus in patient on fluoxetine after receiving fentanyl and low-dose methylene blue during sentinel lymph node biopsy.

    Science.gov (United States)

    Larson, Kelly J; Wittwer, Erica D; Nicholson, Wayne T; Weingarten, Toby N; Price, Daniel L; Sprung, Juraj

    2015-05-01

    Serotonin released in the nerve synapses is cleared through reuptake into presynaptic neurons and metabolism with monoamine oxidase (MAO). Therapy with selective serotonin reuptake inhibitors (SSRIs) or MAO inhibitors increases serotonin concentration in the synaptic cleft and may result in serotonin syndrome (SS). Our patient undergoing sentinel lymph node biopsy was on fluoxetine (SSRI) and intraoperatively developed SS after receiving fentanyl (200 μg) and methylene blue (MAO inhibitor), 7 mg subcutaneously into the scalp. Initial presentation was several episodes of generalized muscle activity, which was later diagnosed as lower extremity myoclonus consistent with SS. Upon awakening, the patient showed no evidence of encephalopathy, and the clonus was less intense. The patient was discharge home the next day. Our case suggests the possibility that even a small dose of methylene blue, when administered simultaneously with other serotoninergic medications, may be associated with serotonin toxicity.

  7. Modified use of methylene blue in the tissue compression technique to detect sarcocysts in meat-producing animals.

    Science.gov (United States)

    Ng, Yit Han; Subramaniam, Vellayan; Lau, Yee Ling

    2015-11-30

    Sarcocystosis in meat-producing animals is a major cause of reduced productivity in many countries, especially those that rely on agriculture. Although several diagnostic methods are available to detect sarcocystosis, many are too time-consuming for routine use in abattoirs and meat inspection centers, where large numbers of samples need to be tested. This study aimed to compare the sensitivity of the methylene blue tissue preparation, unstained tissue preparation and nested PCR in the detection of sarcocysts in tissue samples. Approximately three-fold more sarcocysts were detected in methylene blue-stained tissue compared to unstained controls (McNemar's test: Pmethylene blue can be used in tissue compression as a rapid, safe, and inexpensive technique for the detection of ruminant sarcocystosis in abattoirs.

  8. INFLUENCE OF THE SIZE OF METHYLENE SPACERS ON THE THERMAL BEHAVIOR OF SEVERAL ALIPHATIC-AROMATIC POLYESTERS

    Directory of Open Access Journals (Sweden)

    NATALIA HURDUC

    2014-04-01

    Full Text Available Polyesters have a wide range of technical applications and therefore their processing is of the utmost importance. Since polyesters are usually processed by melting, their thermal stability is an extremely important characteristic for the exact determination of the operational parameters. The thermal analysis was carried out using a MOM-Budapest derivatograph at the 10 C/min heating speed, aluminum oxide the reference material, and the air conditions were static. The study lead to conclusions on the thermal stability and degradation mechanism depending on the number of methylene groups in the spacer. Thermal stability is supported by the increase in the number of methylene groups in the spacer. The degradation mechanism is complex through successive reactions. The spacer size influences the nature of the micromolecules formed by spacer fragmenting and by the number of carbon atoms, respectively.

  9. Azure B, a metabolite of methylene blue, is a high-potency, reversible inhibitor of monoamine oxidase

    OpenAIRE

    Petzer, Anél; Harvey, Brian H; Wegener, Gregers; Petzer, Jacobus P.

    2012-01-01

    Methylene blue (MB) has been shown to act at multiple cellular and molecular targets and as a result possesses diverse medical applications. Among these is a high potency reversible inhibition of monoamine oxidase A (MAO-A) that may, at least in part, underlie its adverse effects but also its psycho- and neuromodulatory actions. MB is metabolized to yield N-demethylated products of which azure B, the monodemethyl species, is the major metabolite. Similar to MB, azure B also displa...

  10. Inhibition of Hsp70 by Methylene Blue Affects Signaling Protein Function and Ubiquitination and Modulates Polyglutamine Protein Degradation*

    OpenAIRE

    Wang, Adrienne M; Morishima, Yoshihiro; Clapp, Kelly M.; Peng, Hwei-Ming; Pratt, William B.; Gestwicki, Jason E.; Osawa, Yoichi; Lieberman, Andrew P.

    2010-01-01

    The Hsp90/Hsp70-based chaperone machinery regulates the activity and degradation of many signaling proteins. Cycling with Hsp90 stabilizes client proteins, whereas Hsp70 interacts with chaperone-dependent E3 ubiquitin ligases to promote protein degradation. To probe these actions, small molecule inhibitors of Hsp70 would be extremely useful; however, few have been identified. Here we test the effects of methylene blue, a recently described inhibitor of Hsp70 ATPase activity, in three well est...

  11. SYNTHESIS AND FREE RADICAL RING-OPENING POLYMERIZATION OF 2 - METHYL-AND 2- METHYL- 9- n- BUTYL- (- 7- METHYLENE- 1,4,6 - TRIOXASPIRO (4, 4 )NONANE )

    Institute of Scientific and Technical Information of China (English)

    PAN Caiyuan; WANG Yin

    1989-01-01

    This paper describes the synthesis and free radical ring- opening polymerization of 2 - methyl-and2 - methyl - 9 - n - butyl ( - 7 - methylene - 1,4, 6 - trioxaspiro (4, 4 ) nonane ). The structures of the two polymers were verified by IR, 1H and 13C NMR spectra. The substituent on 9-position of 7-methylene- trioxaspiro (4, 4 ) nona ne affects the structure of polymer and polymerization activity. The polymerization mechanism is discussed .

  12. Optimization of methylene blue using Ca(2+) and Zn(2+) bio-polymer hydrogel beads: A comparative study.

    Science.gov (United States)

    Kumar, M; Tamilarasan, R; Arthanareeswaran, G; Ismail, A F

    2015-11-01

    Recently noted that the methylene blue cause severe central nervous system toxicity. It is essential to optimize the methylene blue from aqueous environment. In this study, a comparison of an optimization of methylene blue was investigated by using modified Ca(2+) and Zn(2+) bio-polymer hydrogel beads. A batch mode study was conducted using various parameters like time, dye concentration, bio-polymer dose, pH and process temperature. The isotherms, kinetics, diffusion and thermodynamic studies were performed for feasibility of the optimization process. Freundlich and Langmuir isotherm equations were used for the prediction of isotherm parameters and correlated with dimensionless separation factor (RL). Pseudo-first order and pseudo-second order Lagegren's kinetic equations were used for the correlation of kinetic parameters. Intraparticle diffusion model was employed for diffusion of the optimization process. The Fourier Transform Infrared Spectroscopy (FTIR) shows different absorbent peaks of Ca(2+) and Zn(2+) beads and the morphology of the bio-polymer material analyzed with Scanning Electron Microscope (SEM). The TG & DTA studies show that good thermal stability with less humidity without production of any non-degraded products.

  13. Ionic imbalance and lack of effect of adjuvant treatment with methylene blue in the hamster model of leptospirosis

    Directory of Open Access Journals (Sweden)

    Cleiton Silva Santos

    2013-06-01

    Full Text Available Leptospirosis in humans usually involves hypokalaemia and hypomagnesaemia and the putative mechanism underlying such ionic imbalances may be related to nitric oxide (NO production. We previously demonstrated the correlation between serum levels of NO and the severity of renal disease in patients with severe leptospirosis. Methylene blue inhibits soluble guanylyl cyclase (downstream of the action of any NO synthase isoforms and was recently reported to have beneficial effects on clinical and experimental sepsis. We investigated the occurrence of serum ionic changes in experimental leptospirosis at various time points (4, 8, 16 and 28 days in a hamster model. We also determined the effect of methylene blue treatment when administered as an adjuvant therapy, combined with late initiation of standard antibiotic (ampicillin treatment. Hypokalaemia was not reproduced in this model: all of the groups developed increased levels of serum potassium (K. Furthermore, hypermagnesaemia, rather than magnesium (Mg depletion, was observed in this hamster model of acute infection. These findings may be associated with an accelerated progression to acute renal failure. Adjuvant treatment with methylene blue had no effect on survival or serum Mg and K levels during acute-phase leptospirosis in hamsters.

  14. Enhanced visible light photocatalytic degradation of methylene blue by F-doped TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Wei [Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, Shanghai 200062 (China); Liu, Xinjuan, E-mail: lxj669635@126.com [Shanghai Nanotechnlogy Promotion Center, Shanghai 200237 (China); Center for Coordination Bond and Electronic Engineering, College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China); Pan, Likun, E-mail: lkpan@phy.ecnu.edu.cn [Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, Shanghai 200062 (China); Li, Jinliang; Liu, Junying [Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, Shanghai 200062 (China); Zhang, Jing; Li, Ping; Chen, Chen [Shanghai Nanotechnlogy Promotion Center, Shanghai 200237 (China); Sun, Zhuo [Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, Shanghai 200062 (China)

    2014-11-15

    Graphical abstract: F-doped TiO2 is synthesized using a modified sol–gel method for visible photocatalytic degradation of MB with a high degradation rate of 91%. - Highlights: • F-doped TiO{sub 2} are synthesized using a modified sol–gel method. • The photocatalytic degradation of methylene blue by F-doped TiO{sub 2} is investigated. • A high methylene blue degradation rate of 91% is achieved under visible light irradiation. - Abstract: F-doped TiO{sub 2} (F-TiO{sub 2}) were successfully synthesized using a modified sol–gel method. The morphologies, structures, and photocatalytic performance in the degradation of methylene blue (MB) were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, UV–vis absorption spectroscopy, and electrochemical impedance spectra, respectively. The results show that F-TiO{sub 2} exhibits an enhanced photocatalytic performance in the degradation of MB with a maximum degradation rate of 91% under visible light irradiation as compared with pure TiO{sub 2} (32%). The excellent photocatalytic activity is due to the contribution from the increased visible light absorption, promoted separation of photo-generated electrons and holes as well as enhanced photocatalytic oxidizing species with the doping of F in TiO{sub 2}.

  15. Sol-gel-cum-hydrothermal synthesis of mesoporous Co-Fe@Al₂O₃−MCM-41 for methylene blue remediation

    Indian Academy of Sciences (India)

    AMARESH C PRADHAN; ANIMESH PAUL; G RANGA RAO

    2017-03-01

    A combined sol-gel-cum-hydrothermalmethod has been employed to synthesize novelmonometallic (Mn, Fe, Co) and bimetallic (Co-Fe, Mn-Co, Fe-Mn) nanoparticles loaded onto Al₂O₃−MCM-41. Powder XRD, N2 sorption, field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) measurements show that the materials possess mesoporosity, high surface area and nanosize. Monometallic Fe, Co and Mn @Al₂O₃−MCM-41 and bimetallic Co-Fe, Fe-Mn and Mn-Co @Al₂O₃−MCM-41 materials were tested for methylene blue remediation from aqueous media. In the present study, Co-Fe@Al₂O₃−MCM-41 was found to be an excellent adsorbent. The adsorption efficiency of Co- Fe@Al₂O₃−MCM-41 has been studied as a function of adsorbent dose and pH of the solution. Maximum adsorption of methylene blue was obtained at high pH values of the solution. Framework mesoporosity, high surface area, and narrow pore distribution are the key factors for an efficient adsorption of methylene blue onCo-Fe@Al₂O₃−MCM-41.

  16. SYNTHESIS AND CHARACTERIZATIONOF ORGANIC FUNCTIONALIZED MESOPOROUS SILICA AND EVALUATE THEIR ADSORPTIVE BEHAVIOR FOR REMOVAL OF METHYLENE BLUE FROM AQUEOUS SOLUTION

    Directory of Open Access Journals (Sweden)

    Sameer H. Kareem

    2014-01-01

    Full Text Available Three Mesoporous Silica (MPS with different functional groups were prepared by one-step synthesis based on the simultaneous hydrolysis and condensation of tetraethoxy silane with organo-silane in the presence of template surfactant Polydimethylsiloxane-Polyethyleneoxide (PDMS-PEO. The prepared materials were characterized by Fourier Transform Infrared Spectroscopy (FTIR, Thermogravimetric Analysis (TGA and nitrogen adsorption-desorption experiments. The results indicate that the preparation of methyl and phenyl functionalized silica were successful. The adsorption behavior of methylene blue from aqueous systems onto these mesoporous silica has been studied. Batch experiments were carried out to measure the adsorption as a function of contact time, initial concentration (2.5-20 mg L-1 and temperature (288, 298, 308 and 318 K. The equilibrium of the process was achieved within (30-60 min. The adsorption of methylene blue on the mesoporous silica increases with increasing temperature which indicating an endothermic process. Adsorption isotherms were fitted with the Langmuir, Freundlich models. The kinetic data were analyzed using pseudo-first- order and pseudo-second-order models and intraparticle diffusion. The adsorption kinetics of methylene blue on mesoporous silica matched well with pseudo-second order kinetic model.

  17. Fully-automated radiosynthesis and in vitro uptake investigation of [N-methyl-¹¹C]methylene blue.

    Science.gov (United States)

    Schweiger, Lutz F; Smith, Tim A D

    2013-10-01

    Malignant melanoma is a type of skin cancer which can spread rapidly if not detected early and left untreated. Positron Emission Tomography (PET) is a powerful imaging technique for detecting cancer but with only a limited number of radiotracers available the development of novel PET probes for detection and prevention of cancer is imperative. In the present study we present the fully-automated radiosynthesis of [N-methyl-(11)C]methylene blue and an in vitro uptake study in metastasic melanoma cell lines. Using the GE TRACERlab FXc Pro module [N-methyl-(11)C]methylene blue was isolated via solid-phase extraction in an average time of 36 min after end of bombardment and formulated with a radiochemical purity greater than 95%. The in vitro uptake study of [N-methyl-(11)C]methylene blue in SK-MEL28 melanin-expressing melanoma cell line demonstrated in site-specific binding of 51% promoting it as a promising melanoma PET imaging agent.

  18. Water-insoluble sericin/β-cyclodextrin/PVA composite electrospun nanofibers as effective adsorbents towards methylene blue.

    Science.gov (United States)

    Zhao, Rui; Wang, Yong; Li, Xiang; Sun, Bolun; Jiang, Ziqiao; Wang, Ce

    2015-12-01

    A novel water-insoluble sericin/β-cyclodextrin/poly (vinyl alcohol) composite nanofiber adsorbent was prepared by electrospinning and followed by thermal crosslinking for removal of cationic dye methylene blue from aqueous solution. Fourier transform infrared spectroscopy and solubility experiments confirmed that sericin and β-cyclodextrin were incorporated into the nanofibers and the crosslinking reaction occurred successfully. Kinetics, isotherms and thermodynamics analysis were studied for adsorption of methylene blue. The adsorption process is better fitted with the pseudo-second-order model and Langmuir isotherm model. The maximum adsorption capacities are 187.97, 229.89, and 261.10mg/g at the temperatures 293, 313 and 333 K, respectively. Thermodynamic parameters showed that methylene blue adsorption was endothermic and spontaneous. In addition, the fiber membrane adsorbent could be easily separated from dye solution and showed high recyclable removal efficiency. All these results suggest that crosslinked sericin/β-cyclodextrin/poly(vinyl alcohol) composite nanofibers could be potential recyclable adsorbents in dye wastewater treatment.

  19. Quantification of metabolically active biomass using Methylene Blue dye Reduction Test (MBRT): measurement of CFU in about 200 s.

    Science.gov (United States)

    Bapat, Prashant; Nandy, Subir Kumar; Wangikar, Pramod; Venkatesh, K V

    2006-04-01

    Quantification of viable cells is a critical step in almost all biological experiments. Despite its importance, the methods developed so far to differentiate between viable and non-viable cells suffer from major limitations such as being time intensive, inaccurate and expensive. Here, we present a method to quantify viable cells based on reduction of methylene blue dye in cell cultures. Although the methylene blue reduction method is well known to check the bacterial load in milk, its application in the quantification of viable cells has not been reported. We have developed and standardized this method by monitoring the dye reduction rate at each time point for growth of Escherichia coli. The standard growth curve was monitored using this technique. The Methylene Blue dye Reduction Test (MBRT) correlates very well with Colony Forming Units (CFU) up to a 800 live cells as established by plating. The test developed is simple, accurate and fast (200 s) as compared to available techniques. We demonstrate the utility of the developed assay to monitor CFU rapidly and accurately for E. coli, Bacillus subtilis and a mixed culture of E. coli and B. subtilis. This assay, thus, has a wide applicability to all types of aerobic organisms.

  20. ZnO microspheres-reduced graphene oxide nanocomposite for photocatalytic degradation of methylene blue dye

    Science.gov (United States)

    Qin, Jiaqian; Zhang, Xinyu; Yang, Chengwu; Cao, Meng; Ma, Mingzhen; Liu, Riping

    2017-01-01

    In this work, ZnO microspheres-reduced graphene oxide (rGO) nanocomposites were synthesized via a simple solution method and used for the photodegradation of methylene blue (MB) dye from water under UV light. The SEM and TEM observations demonstrate that the microsphere morphologies of the ZnO microspheres-rGO nanocomposite is composed of ZnO microspheres anchored on rGO sheets, confirming the formation of ZnO microspheres-rGO composites. Raman spectra and X-ray photoelectron spectroscopy reveal that both of the reduction of GO tight contact between ZnO and rGO are achieved during the high temperature calcination process. During the photocatalytic test, in comparison with ZnO microspheres and P25 TiO2, the ZnO microspheres-rGO nanocomposite shows improved photodegradation of MB dye, because the rGO sheets could reduce the charge recombination in electron-transfer processes. According to the scavenger experiments, the possible MB degradation mechanism is contributed mainly to the generation of active species induced by the photogenerated holes (h+) and superoxide radicals (rad O2-).

  1. Neuroprotective efficacy of methylene blue in ischemic stroke: an MRI study.

    Directory of Open Access Journals (Sweden)

    Qiang Shen

    Full Text Available Methylene blue (MB has unique energy-enhancing and antioxidant properties and is FDA-approved drug to treat methemoglobinemia and cyanide poisoning. This study evaluated the efficacy of MB to treat ischemic stroke in rats using longitudinal MRI and behavioral measures. Rats were subjected to 60-minute middle-cerebral-artery occlusion. In a randomized double-blinded design, vehicle or MB was administered after reperfusion. The initial lesion volumes at 30 minutes post-ischemia were not significantly different between the two groups (P = 0.92. The final infarct volumes two days after stroke increased in the vehicle group but decreased in the MB group, yielding a 30% difference in infarct volume (P = 0.03. Tracking tissue fate on a pixel-by-pixel basis showed that MB salvaged more initial core pixels compared to controls (22±3% versus 11±3%, P = 0.03, and more mismatch pixels compared to controls (83±3% versus 61±8%, P = 0.02. This study demonstrates MB treatment minimizes ischemic brain injury and improves functional outcomes.

  2. Novel silicone-based polymer containing active methylene designed for the removal of indoor formaldehyde.

    Science.gov (United States)

    Niu, Song; Yan, Hongxia

    2015-04-28

    Indoor air pollution is caused inevitably due to complicated home decoration, in which formaldehyde is one of the most typical pollutants. It will be a convenient, economical and effective strategy to remove indoor formaldehyde if imparting a feature of formaldehyde removal to decorative coatings. We have successfully explored a novel silicone-based polymer containing active methylene used as a formaldehyde absorbent in coatings via a straightforward transesterification process using inexpensive and easily available chemicals. The polymer has been characterized by (13)C NMR, FTIR, GC and GPC. Formaldehyde removal capacity of the coating films containing different contents of the polymer has been investigated. The results indicated that coatings incorporating 4wt% of the polymer could make the coating films exhibit significant improvement on formaldehyde removal including purificatory performance (>85%) and durability of purificatory effect (>60%), compared to those consisting of absorbents without any silicon, and improve yellowing resistance performance, while other properties, such as gloss, adhesion, pencil hardness, flexibility and impact resistance, were kept almost unaffected. The chemical absorption process of the silicone-based polymer filled in interior decorative coatings is demonstrated as a promising technology to purify indoor formaldehyde and thus can reduce the harm to individuals.

  3. Synthesis of citric acid functionalized magnetic graphene oxide coated corn straw for methylene blue adsorption.

    Science.gov (United States)

    Ge, Heyi; Wang, Cuicui; Liu, Shanshan; Huang, Zhen

    2016-12-01

    The citric acid functionalized magnetic graphene oxide coated corn straw (CA-mGOCS) as a new adsorbent was synthesized in this work for the elimination of methylene blue (MB) from waste water. The as-prepared CA-mGOCS was tested by SEM, FTIR, XRD, Roman spectrum, TGA, particle size analyzer, BET and magnetic properties analyzer. Some factors affecting adsorption removal efficiency were explored. As a result, the addition of 5g CS (CA-mGO5CS) had the better adsorption performance than other adsorbents. The pseudo-second-order model and the Freundlich described the adsorption behavior well. The equilibrium adsorption capacity was 315.5mgg(-1) for MB at pH=12 and 298k. The electrostatic incorporation as well as hydrophobic interactions between CA-mGO5CS and MB determined the favourable adsorption property. Besides, the thermodynamic studies results ΔGadsorption was a spontaneous, exothermic and randomness decrease process. Finally, reusability studies imply that CA-mGO5CS has an excellent reproducibility.

  4. Effective ultrasound electrochemical degradation of methylene blue wastewater using a nanocoated electrode.

    Science.gov (United States)

    Yang, Bo; Zuo, Jiane; Tang, Xinhua; Liu, Fenglin; Yu, Xin; Tang, Xinyao; Jiang, Hui; Gan, Lili

    2014-07-01

    A novel sonoelectrochemical catalytic oxidation-driven process using a nanocoated electrode to treat methylene blue (MB) wastewater was developed. The nano-scale (nanocoated) electrode generated more hydroxyl radicals than non-nano-scale (non-nanocoated) electrodes did. However, hydroxyl radicals were easily adsorbed by the nanomaterial and thus were not able to enter the solution. Supersonic waves were found to enhance the mass-transfer effect on the nanocoated electrode surface, resulting in rapid diffusion of the generated hydroxyl radicals into the solution. In solution, the hydroxyl radicals then reacted with organic pollutants in the presence of ultrasonic waves. The effect of the nanocoated electrode on the MB wastewater treatment process was enhanced by ultrasound when compared to the non-nanocoated electrode used under the same conditions. The synergy of the nanocoated electrode and ultrasonic waves towards MB degradation was then studied. The optimum operating conditions resulted in a 92% removal efficiency for TOC and consisted of a current of 600 mA, an ultrasound frequency of 45 kHz, and a supersonic power of 250 W. The mechanism of ultrasound enhancement of the nanocoated electrode activity with respect to MB treatment is discussed. The reaction intermediates of the sonoelectrochemical catalytic oxidation process were monitored, and degradation pathways were proposed. The sonoelectrochemical catalytic oxidation-driven process using nanocoated electrodes was found to be a very efficient method for the treatment of non-biodegradable wastewater.

  5. Photocatalytic Degradation of Methylene Blue Using TiO2 Impregnated Diatomite

    Directory of Open Access Journals (Sweden)

    Ranfang Zuo

    2014-01-01

    Full Text Available Nano-TiO2 showed a good catalytic activity, but it is easy to agglomerate, resulting in the reduction or even complete loss of photocatalytic activity. The dispersion of TiO2 particles on porous materials was a potential solution to this problem. Diatomite has high specific surface and absorbability because of its particular shell structure. Thus, TiO2/diatomite composite, prepared by loading TiO2 on the surface of diatomite, was a good photocatalyst, through absorbing organic compounds with diatomite and degrading them with TiO2. Scanning electron microscopy (SEM, energy dispersive spectrum (EDS, X-ray diffraction (XRD, chemical analysis, and Fourier transform infrared spectrometry (FTIR indicated that TiO2 was impregnated well on the surface of diatomite. Furthermore, TiO2/diatomite was more active than nano-TiO2 for the degradation of methylene blue (MB in solution. MB at concentrations of 15 and 35 ppm can be completely degraded in 20 and 40 min, respectively.

  6. Study of Methylene Blue Degradation by Gold Nanoparticles Synthesized within Natural Zeolites

    Directory of Open Access Journals (Sweden)

    Ericka Rodríguez León

    2016-01-01

    Full Text Available We carried out the in situ synthesis of gold nanoparticles inside a natural clinoptilolite-type zeolite matrix, using ascorbic acid as reducing agent. The microstructure of both zeolite and zeolite-gold nanocomposite was characterized by X-ray diffraction (XRD, Scanning Electron Microscopy (SEM, Scanning Transmission Electron Microscopy (STEM, and Energy-Dispersive X-ray Spectroscopy (EDS techniques. Size distribution as assessed by STEM indicated that 60% of gold nanoparticles measured less than 2.5 nm. Determination of the surface area by the BET method revealed a specific value of 27.35 m2/g. The catalytic activity of zeolite-gold regarding methylene blue degradation under different light-exposing conditions was evaluated by UV-Vis spectroscopy. The results indicated that 50% degradation was achieved in only 11 min in presence of sunlight. This reaction was faster in comparison with those obtained using a white LED light. A notable aspect of this study is that catalysis was carried out without the addition of any strong reducing agents, such as sodium borohydride (NaBH4.

  7. Photocatalytic Activity of W-Doped TiO2 Nanofibers for Methylene Blue Dye Degradation.

    Science.gov (United States)

    Song, Yo-Seung; Cho, Nam-Ihn; Lee, Myung-Hyun; Kim, Bae-Yeon; Lee, Deuk Yong

    2016-02-01

    Photocatalytic degradation of methylene blue (MB) in water was examined using W-doped TiO2 nanofibers prepared by a sol-gel derived electrospinning and subsequent calcination for 4 h at 550 degrees C. Different concentrations of W dopant in the range of 0 to 8 mol% were synthesized to evaluate the effect of W concentration on the photocatalytic activity of TiO2. XRD results indicated that the undoped TiO2 is composed of anatase and rutile phases. The rutile phase was transformed to anatase phase completely with the W doping. Among W-TiO2 catalysts, the 2 mol% W-TiO2 catalyst showed the highest MB degradation rate. The degradation kinetic constant increased from 1.04 x 10(-3) min(-1) to 3.54 x 10(-3) min(-1) with the increase of W doping from 0 to 2 mol%, but decreased down to 1.77 x 10(-3) min(-1) when the W content was 8 mol%. It can be concluded that the degradation of MB under UV radiation was more efficient with W-TiO2 catalysts than with pure TiO2-

  8. Catalytic degradation of methylene blue by biosynthesised copper nanoflowers using F. benghalensis leaf extract.

    Science.gov (United States)

    Agarwal, Meenakshi; Singh Bhadwal, Akhshay; Kumar, Nishant; Shrivastav, Archana; Raj Shrivastav, Braj; Pratap Singh, Manoj; Zafar, Fahmina; Mani Tripathi, Ravi

    2016-10-01

    This study reports the unprecedented, novel and eco-friendly method for the synthesis of three-dimensional (3D) copper nanostructure having flower like morphology using leaf extract of Ficus benghalensis. The catalytic activity of copper nanoflowers (CuNFs) was investigated against methylene blue (MB) used as a modal dye pollutant. Scanning electron micrograph evidently designated 3D appearance of nanoflowers within a size range from 250 nm to 2.5 μm. Energy-dispersive X-ray spectra showed the presence of copper elements in the nanoflowers. Fourier-transform infrared spectra clearly demonstrated the presence of biomolecules which is responsible for the synthesis of CuNFs. The catalytic activity of the synthesised CuNFs was monitored by ultraviolet-visible spectroscopy. The MB was degraded by 72% in 85 min on addition of CuNFs and the rate constant (k) was found to be 0.77 × 10(-3) s(-1). This method adapted for synthesis of CuNFs offers a valuable contribution in the area of nanomaterial synthesis and in water research by suggesting a sustainable and an alternative route for removal of toxic solvents and waste materials.

  9. AgBr/nanoAlMCM-41 visible light photocatalyst for degradation of methylene blue dye.

    Science.gov (United States)

    Pourahmad, A; Sohrabnezhad, Sh; Kashefian, E

    2010-12-01

    A novel photocatalytic material was synthesized by dispersion of AgBr in nanoAlMCM-41 material. The AgBr/nanoAlMCM-41 sample shows strong absorption in the visible region because of the plasmon resonance of Ag nanoparticles in AgBr/nanoAlMCM-41. The catalysts were characterized using XRD (X-ray diffraction), UV-visible diffused reflectance spectra (UV-vis DRS) and scanning electron microscopy (SEM). The photocatalytic activity and stability of the synthesized catalysts were evaluated for methylene blue (MB) degradation in aqueous solution in the presence of 200 W tungsten filament Philips lamp. Several parameters were examined, catalyst amount, pH and initial concentration of MB, AgBr loading. The effect of dosage of photocatalyst was studied in the range 0.05-1.00 g/L. It was seen that 0.1 g/L of photocatalyst is an optimum value for the dosage of photocatalyst. The support size was obtained about 9-100 nm. In the same way, the average size of AgBr nanoparticles was about 10nm before visible radiation. After visible radiation the average size of AgBr nanoparticles was about 25 nm.

  10. Adsorption and Photocatalytic Degradation of Methylene Blue Using Potassium Polytitanate and Solar Simulator.

    Science.gov (United States)

    Shahid, Mohammad; El Saliby, Ibrahim; McDonagh, Andrew; Chekli, Laura; Tijing, Leonard D; Kim, Jong-Ho; Shon, Ho Kyong

    2016-05-01

    Solar photocatalytic degradation of organic water pollutants can be used to degrade toxic organic pollutants in water. In this study, potassium titanate nanofibres were synthesized by an aqueous peroxide route at high pH and examined as photocatalysts for photodegradation of methylene blue (MB) using a solar simulator. Initially, MB was adsorbed on the surface of potassium polytitanates to achieve adsorption equilibrium before the photocatalysts were illuminated using solar simulator. The results showed that potassium polytitanate nanofibres were effective adsorbents of MB and also facilitated its photocatalytic degradation. Sulphate ion evolution during photocatalysis confirmed that some mineralisation occurred and hence photo-oxidative degradation of MB took place. The optimum operational conditions for the photocatalytic degradation of MB were found at 0.05 g/L of photocatalyst load, 10 mg/L MB and pH 7. The stability and regeneration of the photocatalyst specimen was also studied for 3 degradation cycles using adsorption/photocatalysis model. Morphological structure analysis of potassium titanate showed nanocrystallines structure of longitudinally-oriented isolated fibre with a length up to several micrometres with diameters ranging from 10 to 20 nanometres.

  11. Enhanced photocatalytic activity of TiO₂-C hybrid aerogels for methylene blue degradation.

    Science.gov (United States)

    Shao, Xia; Lu, Wencong; Zhang, Rui; Pan, Feng

    2013-10-22

    Carbon-based TiO₂ composites have many advantages as photocatalysts. However, they suffer from low light efficiency due to the low contrast of TiO₂ with carbon. We synthesized a novel type of anatase-type TiO₂-C hybrid aerogel by a one-pot sol-gel method, which shows a photocatalytic activity for methylene degradation up to 4.23 times that of P25, a commercial photocatalyst from Degussa Inc. The hybrid aerogels are prepared from TiCl₄ and resorcinol-furfural, and have a tunable macropore size from 167 to 996 nm. They are formed of submicrometer particles that consist of interwoven anatase and carbon nanoparticles. The anatase nanoparticles have a size of 8-9 nm and a tunable oxygen vacancy from 7.2 to 18.0%. The extremely high activity is ascribed to the large light absorption caused by macropore scattering and oxygen vacancies in the anatase. These findings may open up a new avenue and stimulate further research to improve photocatalytic performance.

  12. Titamium oxide (TiO2) assisted photocatalytic degradation of methylene blue.

    Science.gov (United States)

    Madhu, G M; Raj, M A Lourdu Antony; Pai, K Vasantha Kumar

    2009-03-01

    The aqueous solution of methylene blue (MB) has been subjected to Photocatalytic degradation by UV radiation in presence of TiO2 photo-catalyst containing different concentrations of H2O2. The experiments conducted at different dye concentrations (12 and 20 ppm), catalyst loading, pH and H2O2 dosage (1-10 ml l(-1)), revealed that the degradation rate is strongly influenced by respective experimental parameters. However the influence of catalyst alone is not predominant in degradation. The decolorization of dye proceed to near completeness when H2O2 is used. The best degradation results are observed at 0.1 wt% of catalyst loading at pH 2 for TiO2/UV system. It has been found that the optimum concentration of H2O2 for 12 ppm and 20 ppm amount of the dye was 2 ml l(-1) for UV/H2O2 system. The kinetic of degradation of the dye followed the pseudo first order rate. The degradation studies using TiO2/UV/H2O2 system, indicates enhancement in the degradation rate of the dye compared to that of UV/H2O2 system alone.

  13. Kinetic Modeling for Microwave-Enhanced Degradation of Methylene Blue Using Manganese Oxide

    Directory of Open Access Journals (Sweden)

    Wen-Hui Kuan

    2013-01-01

    Full Text Available This study was originally performed to compare the MnO2-based degradation of aqueous methylene blue (MB under microwave irradiation- (MW- enhanced and conventional heating- (CH- enhanced conditions. The degradation process and kinetics were investigated to elucidate the microwave effect on the reaction. The results showed that all three tested conditions, sole MnO2, MnO2/CH, and MnO2/MW, followed the third-order (second upon MB and first upon MnO2 kinetic model. However, a higher degradation rate of MB was available under the MW-enhanced process, which implies that the “athermal effect” of MW might be of more benefit for the generation of electrophilic oxygen ions (, , and to degrade MB. The results showed that the degradation percentage of MB could reach 100%, corresponding to 92% total organic carbon (TOC removal under microwave irradiation at pH 7.20 for 10 min.

  14. Kinetics of Photocatalytic Degradation of Methylene Blue Over CaTiO3

    Institute of Scientific and Technical Information of China (English)

    HAN Chong; YANG He; XUE Xiangxin

    2015-01-01

    Kinetics of photocatalytic degradation of methylene blue (MB) over CaTiO3 was studied. Effects of the solution pH, the MB concentration, the CaTiO3 dosage, and the type of light source on photocatalytic degradation rate of MB over CaTiO3 were investigated in detail. The results show that photocatalytic degradation of MB over CaTiO3 followed the first-order reaction. The apparent rate constant (kobs) of MB signiifcantly increased with increasing solution pH while it greatly decreased with increasing MB concentration. Thekobs of MB increased with increasing CaTiO3 dosage from 0.05 to 0.1 g, whereas it slightly decreased with increasing CaTiO3 dosage in the range of 0.1-0.4 g. Thekobs of MB under UV-visible light irradiation was larger by factors of 2.2 than that under visible light irradiation. Thekobs of MB was (4.8±0.3)×10-1 h-1 under optimal conditions with the solution pH of 11, the MB concentration of 1 ppm, the CaTiO3 dosage of 0.1 g, and UV-visible light irradiation.

  15. Kinetics of Photocatalytic Degradation of Methylene Blue by TiO₂-Graphene Nanocomposites.

    Science.gov (United States)

    Loryuenyong, Vorrada; Charoensuk, Jaruwan; Charupongtawitch, Rachaya; Usakulwattana, Amika; Buasri, Achanai

    2016-01-01

    Reduced graphene oxide (RGO)/TiO₂ nanocomposite was successfully prepared by UV-assisted photocatalytic reduction of graphene oxide (XGO) by TiO₂ nanoparticles in ethanol. The effects of XGO and RGO addition in TiO₂were characterized by transmission electron microscopy (TEM), X-ray diffractometer (XRD), diffuse reflectance UV-vis spectrophotometer (UV-vis), fourier-transform infrared spectroscopy (FTIR), photoluminescence (PL), and Brunauer-Emmett-Teller (BET) and Barrett-Joiner-Halenda (BJH) porosity analysis. The photocatalytic activity of prepared nanocomposites was evaluated from the kinetics of the photocatalytic degradation of cationic methylene blue dye under UV irradiation. Bandgap, the electron-hole recombination, specific surface area, surface functional groups, and adsorption capacity of nanocomposites were found to play a significant role in the degradation. The results revealed that RGO/TiO₂ and XGO/TiO₂ nanocomposites exhibited efficient charge separation and enhanced photocatalytic activity, compared to pristine TiO₂. Nearly 500% improvement was observed in this work.

  16. New insights on degradation of methylene blue using thermocatalytic reactions catalyzed by low-temperature excitation.

    Science.gov (United States)

    Luo, Xuegang; Zhang, Sizhao; Lin, Xiaoyan

    2013-09-15

    Although photocatalysis has been actively surveyed on removing organic pollutants in ultraviolet (UV) environment, because of lacking UV in solar exposure, photodegradation is difficult to be considerably degraded in conventional exposure condition. In this work, an innovative approach was proposed to compensate for it, which was developed in model wastewater using thermal sensitizer at room temperature. At the optimal component condition, the removal rate of adsorption and thermocatalytic degradation processes can reach the highest level of 82.07% solely response to temperature in the dark. Moreover, the kinetics of degradation rate was modeled considering that it was found similarly to Langmuir-Hinshelwood behavior, and a tentative mechanism was objectively established, describing reasonably well in line with the experimental results. On the other hand, it was found that high amount of methylene blue (MB) adsorbed onto thermal sensitizer was of unambiguous importance to subsequent thermocatalytic performance. Briefly, all above suggest that the feasibility to the thermodegradation route has been successfully verified under room temperature excitation. Herein the insight into degradation pattern of dye over thermal excitation may further enlarge applications for wastewater treatment.

  17. Peroxidase-Like Activity of Ferrihydrite and Hematite Nanoparticles for the Degradation of Methylene Blue

    Directory of Open Access Journals (Sweden)

    Nicolaza Pariona

    2016-01-01

    Full Text Available The peroxidase-like catalytic properties of 2-line ferrihydrite (2LFh and hematite nanoparticles (NPs for the degradation of methylene blue (MB were studied. It is highlighted that the hematite NPs were prepared from the transformation of the metastable 2LFh NPs. It was found that the 2LFh NPs exhibited poor crystallinity with an average size of 5 nm, while the hematite NPs exhibited high crystallinity with an average size of ca. 100 nm. It was found that the total degradation of MB occurred for hematite NPs, while only a maximum degradation of 69% was possible for the 2LFh NPs. The Michaelis–Menten parameters indicated that the hematite NPs present higher catalytic activity than the 2LFh NPs at basic pH. It was found that the ordered surface of the hematite NPs has a stronger effect for the degradation of MB than its low surface area. It was concluded that the crystal planes of the hematite NPs affect the catalytic process more significantly than the high surface area of 2LFh NPs.

  18. Degradation of aqueous methylene blue using an external loop airlift sonophotoreactor: Statistical analysis and optimization.

    Science.gov (United States)

    Mohajerani, Masroor; Mehrvar, Mehrab; Ein-Mozaffari, Farhad

    2016-07-28

    Degradation and mineralization of aqueous methylene blue (MB) are investigated in a bench scale external loop airlift sonophotoreactor. A central composite design along with response surface methodology is employed to model and optimize the sonophotolytic process. A quadratic empirical expression between responses and independent variables (pH and initial concentrations of H2O2 and MB) is derived. The efficiencies of the system for the MB degradation after 10, 15, and 30 min, and total organic carbon reduction after 150 min are considered as responses. The analysis of variance performed high values for the coefficient of determination R(2) and adjusted R(2) for all four responses. Optimum values of process variables for the maximum degradation and mineralization efficiency are pH 6.6 and initial concentrations of H2O2 and MB are 1,280 and 10.56 mg/L, respectively. With optimal operating conditions, 99.93% and 55.32% MB removal (after 10 min) and TOC reduction (after 150 min) are achieved, respectively. Artificial neural networks are also used to model the experimental data. The respirometric study is conducted to compare the biodegradability of untreated and sonophotolytically pre-treated MB solutions at different reaction times. Pre-treated solutions at 180, 240, and 300 min performed higher biodegradability compared to those of untreated MB solutions.

  19. Photo Decoloration of Methylene Blue with Ribose under Optimum Conditions by Visible Radiation

    Institute of Scientific and Technical Information of China (English)

    AZMAT, Rafia; UDDIN, Fahim

    2009-01-01

    Photo decoloration of the methylene blue (MB) with reducing sugar, ribose (RH), was investigated on an especially designed optical processor using monochromatic radiation of 661 nm through a red filter. The dye molecule gets ex- cited into triplet transient species (MBT) during flushing with lifetime of 10.1 μs into acetate buffered aqueous alcoholic medium, which later on reduces to protonated leuco dye (MBH). Pbotolysis of the aqueous aicholic medium bose into respective acid while hydrogen abstraction and 2e- reduced the dye (MB) into MBH by following reaction MBr++RCHO→MBH+RCOOH. Influences of different operational parameters suggest the imperative role of acidity, reductant and temperature where positive relations with quantum yield (φ) were established under the opti- mum conditions while elevated concentration of dye resulted in the decrease in the absorption of number of photon consequently, and no change in the φ was observed. A highly solvated transient complex was reported in the reduc- tion of MB and RH through thermodynamics activation parameters. A mechanism of MBT formation and its reduc- tion into MBH has been discussed.

  20. Adsorption of Methylene Blue from Aqueous Solution onto Hydrochloric Acid-modified Rectorite

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gaoke; LIU Guanfeng; GUO Yadan

    2011-01-01

    H+-rectorite clay,which was prepared by modifying the raw rectorite with 10% hydrochloric acid at 60 ℃C for 24 h,was used as an absorbent for removal of methyl blue (MB) from aqueous solutions.The morphology and the structure and crystallinity of the pristine rectorite and the H+-rectorite were characterized by scanning electron microscopy (SEM) technique and X-ray diffraction (XRD) technique,respectively.The results showed that the H+-rectorite exhibited high adsorption ability than the raw rectorite,and it was found that the removal percentage of MB increased with increasing in adsorbents dose,whereas the adsorption amount q,(mg/g) decreased.The equilibrium was attained within 30 min in adsorption process,and the maximum adsorption capacity of H+-rectorite for methylene blue reached as high as 37 mg/g.Besides,the effect of temperature on the adsorption of MB with H+-rectorite was investigated and the equilibrium data were well fitted to Freundlich equations.The H+-rectorite absorbent saturated with MB can be regenerated by calcinating at 400 ℃ for 2 h and the regenerated absorbent still showed higher percentage removal of MB.

  1. Decolorization of Methylene Blue by Ag/SrSnO3 Composites under Ultraviolet Radiation

    Directory of Open Access Journals (Sweden)

    Patcharanan Junploy

    2014-01-01

    Full Text Available SrSn(OH6 precursors synthesized by a cyclic microwave radiation (CMR process were calcined at 900°C for 3 h to form rod-like SrSnO3. Further, the rod-like SrSnO3 and AgNO3 in ethylene glycol (EG were ultrasonically vibrated to form rod-like Ag/SrSnO3 composites, characterized by X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, electron microscopy (EM, Fourier transform infrared (FTIR spectroscopy, and UV-visible analysis. The photocatalyses of rod-like SrSnO3, 1 wt%, 5 wt%, and 10 wt% Ag/SrSnO3 composites were studied for degradation of methylene blue (MB, C16H18N3SCl dye under ultraviolet (UV radiation. In this research, the 5 wt% Ag/SrSnO3 composites showed the highest activity, enhanced by the electron-hole separation process. The photoactivity became lower by the excessive Ag nanoparticles due to the negative effect caused by reduction in the absorption of UV radiation.

  2. Photocatalytic Degradation of Methylene Blue under UV Light Irradiation on Prepared Carbonaceous TiO2

    Directory of Open Access Journals (Sweden)

    Zatil Amali Che Ramli

    2014-01-01

    Full Text Available This study involves the investigation of altering the photocatalytic activity of TiO2 using composite materials. Three different forms of modified TiO2, namely, TiO2/activated carbon (AC, TiO2/carbon (C, and TiO2/PANi, were compared. The TiO2/carbon composite was obtained by pyrolysis of TiO2/PANi prepared by in situ polymerization method, while the TiO2/activated carbon (TiO2/AC was obtained after treating TiO2/carbon with 1.0 M KOH solution, followed by calcination at a temperature of 450°C. X-ray powder diffraction (XRD, transmission electron microscopy (TEM, Fourier transform infrared (FTIR, thermogravimetric analysis (TG-DTA, Brunauer-Emmet-Teller (BET, and UV-Vis spectroscopy were used to characterize and evaluate the prepared samples. The specific surface area was determined to be in the following order: TiO2/AC > TiO2/C > TiO2/PANi > TiO2 (179 > 134 > 54 > 9 m2 g−1. The evaluation of photocatalytic performance for the degradation of methylene blue under UV light irradiation was also of the same order, with 98 > 84.7 > 69% conversion rate, which is likely to be attributed to the porosity and synergistic effect in the prepared samples.

  3. Mechanisms of Methylene Blue Degradation in Three-dimensionally Integrated Micro-solution Plasma

    Science.gov (United States)

    Nomura, Ayano; Hayashi, Yui; Tanaka, Kenji; Shirafuji, Tatsuru; Goto, Motonobu

    2015-09-01

    Plasma in aqueous solution has attracted much attention because they are expected to have possibilities to solve water-related environmental issues. In such application-oriented researches, degradation of methylene blue (MB) or other organic dyes has been widely used for investigating the effects of the plasma treatment on the water with organic contaminants. However, there are few reports on the detailed analysis of the products after the plasma treatment of MB aqueous solution for understanding mechanisms of the degradation processes. We have hence analyzed our degradation products using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. We have performed the MB degradation in three-dimensionally integrated micro-solution plasma, which has shown 16-fold higher performance in MB degradation than conventional solution plasma. The results of MALDI-TOF mass spectrometry have indicated the formation of sulfoxides in the first stage of the degradation. Then, the methyl groups on the sulfoxides are partially oxidized. The sulfoxides are separated to form two benzene derivatives after that. Finally, weak functional groups are removed from the benzene derivatives.

  4. Chemically derived luminescent graphene oxide nanosheets and its sunlight driven photocatalytic activity against methylene blue dye

    Science.gov (United States)

    Kumar, Sumeet; Kumar, Ashok

    2016-12-01

    In the present work, graphene oxide (GO) nanosheets (NSs) have been synthesized with precise control over their thickness and molecular structure. The existence of oxygen containing functional groups on GO NSs through chemical treatment confers remarkable optical properties on GO. XRD, TEM, Raman and FTIR techniques were used to confirm the phase and degree of oxidation, morphology, structural information and chemical structure of the synthesized GO NSs. UV-Vis. spectroscopy was employed to study the optical absorption properties of the synthesized GO NSs. The excitation wavelength dependent PL measurements of the synthesized GO NSs were carried out which could be useful for the design and development of GO based next generation optoelectronic devices. The most fascinating luminescent property of synthesized GO NSs is that its luminescence peak position can be easily tuned by only varying the excitation wavelength without significant changes in its size and chemical composition. In order to study the photocatalytic degradation of methylene blue (MB) dye using GO NSs as a photocatalyst, a sunlight driven photocatalytic activity has been performed. The degradation rate of MB dye becomes fast when GO NSs are added to the dye solution. The photodegradation efficiency of GO NSs is calculated to be 60%. The present results indicate that synthesized GO NSs can be used as sunlight active photocatalyst. The optimistic response to sunlight irradiation validates the potential of GO NSs in solar energy conversion.

  5. Removal of methylene blue and rhodamine B from water by zirconium oxide/graphene

    Directory of Open Access Journals (Sweden)

    Sumita Rani

    2016-04-01

    Full Text Available Methylene blue (MB and rhodamine B dyes (RB were degraded from water using zirconium oxide (ZrO2 and zirconium oxide/graphene composites (ZrO2/GR as photocatalyst. The photocatalytic efficiency was calculated from absorption spectra obtained using UV–visible spectroscopy. It has been observed that photodegradation time as well as photocatalytic efficiency increase with the concentration of catalyst up to a certain limit after which effect was reversed. The degradation was studied as a function of pH also. It was found that photocatalytic efficiency was more in alkaline medium than acidic medium. Degradation of RB takes place at higher value of pH as compared to MB. The degradation time for MB was 1 h using ZrO2 which get reduced to 32 min using ZrO2/GR composite and for RB it reduced to 40 min (using ZrO2/GR from 80 min (ZrO2.

  6. Use of pectin-thorium (IV) tungstomolybdate nanocomposite for photocatalytic degradation of methylene blue.

    Science.gov (United States)

    Gupta, Vinod Kumar; Agarwal, Shilpi; Pathania, Deepak; Kothiyal, N C; Sharma, Gaurav

    2013-07-01

    Pectin-thorium (IV) tungstomolybdate (Pc/TWM) nanocomposite was prepared by mixing biopolymer pectin with its inorganic counterpart thorium (IV) tungstomolybdate (TWM) using the sol-gel method. The nanocomposite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). Distribution coefficient, thermal stability, pH titrations, elution and concentration behaviour were investigated to explore the ion exchange behaviour of nanocomposite material. Pc/TWM exhibited higher ion exchange capacity (1.10 mequiv/g) than its inorganic counterpart (0.62 mequiv/g). The Pc/TWM nanocomposite ion exchanger was thermally stable as it retained 59% of its ion exchange capacity upto 400°C. The pH titrations study revealed the bifunctional nature of Pc/TWM. In order to explore the environmental applicability of the Pc/TWM nanocomposite material, its antibacterial and photocatalytic activities was investigated. 76% of methylene blue dye was photocatalytically degraded after five hours exposure. It also totally inhibited Escherichia coli at 400 μg/ml concentration of Pc/TWM nanocomposite.

  7. Synthesis and in vitro Antimycobacterial Activity of Moxifloxacin Methylene and Ethylene Isatin Derivatives

    Institute of Scientific and Technical Information of China (English)

    FENG Lian-shun; LIU Ming-liang; WANG Shuo; CHAI Yun; LI Su-jie; GUO Hui-yuan

    2012-01-01

    A series of novel moxifloxacin methylene and ethylene isatin derivatives with remarkable improvement in lipophilicity,compared to the parent moxifloxacin,was designed,synthesized and characterized by 1H NMR,MS and HRMS.These derivatives were initially evaluated for their in vitro antimycobacterial activity against M.smegmatis CMCC 93202.Compounds 3a-3f,5a,5f and 5j were chosen for the further evaluation of their in vitro activity against Mycobacterium tuberculosis(MTB) H37Rv ATCC 27294 and MDR-MTB 09710.All the target compounds[minimum inhibitory concentration(M1C):0.39->16 μg/mL] were far more active than rifampin(MIC:2.0->256 μg/mL),but less active than moxifloxacin(MIC:0.1-1.0 μg/mL) against the three tested strains.The most active compounds 3a and 3c were found to be 2-64 fold more potent than isoniazid and rifampin against M.smegmatis CMCC 93202,2 fold more potent than rifampin against MTB H37Rv ATCC 27294,and 16->64 fold more potent than ethambutol,isoniazid and rifampin against MDR-MTB 09710.

  8. Studies on Biosorption of Methylene Blue from Aqueous Solutions by Powdered Palm Tree Flower (Borassus flabellifer

    Directory of Open Access Journals (Sweden)

    M. Srinivas Kini

    2014-01-01

    Full Text Available Biosorption experiments were carried out for the removal of methylene blue (MB using palm tree male flower (PTMF as the biosorbent at various pH, temperature, biosorbent, and adsorbate concentration. The optimum pH was found to be 6.0. The kinetic data were fitted in pseudofirst-order and second-order models. The equilibrium data were well-fitted in Langmuir isotherm and the maximum equilibrium capacities of the biosorbent were found to be 143.6, 153,9, 157.3 mg/g at 303, 313, and 323 K, respectively. Thermodynamic data for the adsorption system indicated spontaneous and endothermic process. The enthalpy and entropy values for adsorption were obtained as 15.06 KJ/mol and 0.129 KJ/mol K, respectively, in the temperature range of 303–323 K. A mathematical model for MB transported by molecular diffusion from the bulk of the solution to the surface of PTMF was derived and the values of liquid phase diffusivity and external mass transfer coefficient were estimated.

  9. Microstructure and photocatalytic activity of natural rutile from China for oxidation of methylene blue in water

    Science.gov (United States)

    Chuan, X.-Y.; Lu, A. H.; Chen, J.; Li, N.; Guo, Y. J.

    2008-05-01

    Natural rutile from China was found to have good photocatalytic activity for methylene blue (MB). Under UV irradiation, 50% of MB was decomposed in three hours by natural rutile, 90% in 77 hours and 100% in 119 hours. The Brunauer-Emmett-Teller (BET) specific surface area of natural rutile was only 0.4495 m2/g. In order to explain the decomposition of MB, rutile was characterized by XRD, FESEM and TEM, revealing a modulated structure. Crystal structural parameters are consistent with the data from JCPDS. Chemical composition approximates to Ti1.019O2. Photocatalytic properties of rutile are believed to relate to metal ionic substitution, vacancies and defects in its microstructure. Natural rutile is a practical photocatalyst, although its reaction rate is a fifth of anatase. Rutile might be effective and practical for a large-scale photocatalytic decomposition of organic pollutants in quiet and still waters (e.g. pools and lakes) since it is relatively cheap and widely available.

  10. Methylene blue-mediated photodynamic therapy enhances apoptosis in lung cancer cells.

    Science.gov (United States)

    Lim, Eun Jin; Oak, Chul-Ho; Heo, Jeonghoon; Kim, Young-Ho

    2013-08-01

    Combined treatment with a photosensitizer and iodide laser [photodynamic therapy (PDT)] has improved the outcome of various cancers. In this study, we investigated the effects of using the photosensitizer methylene blue (MB) in PDT in human lung adenocarcinoma cells. We found that MB enhances PDT-induced apoptosis in association with downregulation of anti-apoptotic proteins, reduced mitochondrial membrane potential (MMP), increased phosphorylation of the mitogen-activated protein kinase (MAPK) and the generation of reactive oxygen species (ROS). In MB-PDT-treated A549 cells, we observed PARP cleavage, procaspase-3 activation, downregulation of the anti-apoptotic proteins Bcl-2 and Mcl-1, and the reduction of mitochondrial membrane potential (MMP). Western blot data showed that phosphorylation of p38 was increased in MB-PDT-treated A549 cells, indicating that several signaling molecules participate in the apoptotic cascade. Our data also showed that apoptotic cell death in MB-PDT-treated cells occurred through a series of steps beginning with the photochemical generation of ROS. Demonstrating the role of ROS, pretreatment of A549 cells with the antioxidant N-acetylcysteine (NAC) followed by MB-PDT resulted in increased cell viability and reduced proteolytic cleavage of PARP.

  11. Graphene oxide mediated delivery of methylene blue for combined photodynamic and photothermal therapy.

    Science.gov (United States)

    Sahu, Abhishek; Choi, Won Il; Lee, Jong Hyun; Tae, Giyoong

    2013-08-01

    Nano graphene oxide sheet (nanoGO) was non-covalently functionalized with Pluronic block copolymer and complexed with methylene blue, a hydrophilic and positively charged photosensitizer, via electrostatic interaction for combined photodynamic-photothermal therapy of cancer. Pluronic coating of nanoGO ensured its stability in biological fluids. NanoGO plays dual role of a photothermal material as well as a delivery agent for photosensitizer. The release of the photosensitizer from nanoGO surface was pH-dependent and an acidic condition increased the release rate considerably. This nanocomplex showed enhanced uptake by cancer cells than normal cells and in the absence of light it showed no major toxicity towards the cells. In contrast, when irradiated with selective NIR laser lights, it induced significant cell death. Intravenous injection of the complex into tumor bearing mice showed high tumor accumulation, and when the tumors were exposed to NIR lights, it caused total ablation of tumor tissue through the combined action of photodynamic and photothermal effects. This work shows the potential of nanoGO for synergistic combination phototherapy of tumor in vivo.

  12. Comparative evaluation of methylene blue and demeclocycline for enhancing optical contrast of gliomas in optical images

    Science.gov (United States)

    Wirth, Dennis; Snuderl, Matija; Curry, William; Yaroslavsky, Anna

    2014-09-01

    Contrast agents have shown to be useful in the detection of cancers. The goal of this study was to compare enhancement of brain cancer contrast using reflectance and fluorescence confocal imaging of two fluorophores, methylene blue (MB) and demeclocycline (DMN). MB absorbs light in the red spectral range and fluoresces in the near-infrared. It is safe for in vivo staining of human skin and breast tissue. However, its safety for staining human brain is questionable. Thus, DMN, which absorbs light in the violet spectral range and fluoresces between 470 and 570 nm, could provide a safer alternative to MB. Fresh human gliomas, obtained from surgeries, were cut in half and stained with aqueous solutions of MB and DMN, respectively. Stained tissues were imaged using multimodal confocal microscopy. Resulting reflectance and fluorescence optical images were compared with hematoxylin and eosin histopathology, processed from each imaged tissue. Results indicate that images of tissues stained with either stain exhibit comparable contrast and resolution of morphological detail. Further studies are required to establish the safety and efficacy of these contrast agents for use in human brain.

  13. Enhanced photodynamic therapy efficacy of methylene blue-loaded calcium phosphate nanoparticles.

    Science.gov (United States)

    Seong, Da-Young; Kim, Young-Jin

    2015-05-01

    Although methylene blue (MB) is the most inexpensive photosensitizer with promising applications in the photodynamic therapy (PDT) for its high quantum yield of singlet oxygen generation, the clinical use of MB has been limited by its rapid enzymatic reduction in the biological environment. To enhance PDT efficacy of MB by preventing the enzymatic reduction, we have developed a new mineralization method to produce highly biocompatible MB-loaded calcium phosphate (CaP-MB) nanoparticles in the presence of polymer templates. The resulting CaP-MB nanoparticles exhibited spherical shape with a size of under 50 nm. Fourier transform infrared (FT-IR) and zeta-potential analyses confirmed the insertion of MB into the CaP-MB nanoparticles. The encapsulation of MB in CaP nanoparticles could effectively protect MB from the enzymatic reduction. In addition, the CaP-MB nanoparticles exhibited a good biocompatibility in the dark condition and significantly enhanced PDT efficacy due to apoptotic cell death against human breast cancer cells as compared with free MB, implying that CaP-MB nanoparticle system might be potentially applicable in PDT.

  14. Preparation, Characterization and Methylene Blue Dye Adsorption Ability of Acid Activated-Natural Zeolite

    Science.gov (United States)

    Saputra, O. A.; Prameswari, M. D.; Kinanti, V. T. D.; Mayasari, O. D.; Sutarni, Y. D.; Apriany, K.; Lestari, W. W.

    2017-02-01

    The aim of this research was to prepare an acid-activated natural zeolite (Ac-Zeo) as a low-cost adsorbent material and to investigate their ability on methylene blue dye removal in aqueous solution. The natural zeolite was activated using hydrochloric acid and the final product was characterized using Fourier transform infra-red (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The adsorption process was carried out using the batch method. Some parameters like pH condition, contact time and varied dye initial concentration were studied to determine the adsorption ability of Ac-Zeo. In this study, kinetic adsorption was evaluated using pseudo-second order model approach and found that the kinetic adsorption rate constanta (k) and adsorption capacity at equilibrium are 0.1872 mg.g-1.min-1 and 14.94 mg.g-1, respectively. Moreover, Langmuir, Freundlich, and Dubinin–Kaganer–Radushkevich isotherm adsorption models as well as sorption mechanism were studied in this research.

  15. Chemical convection in the methylene-blue-glucose system: Optimal perturbations and three-dimensional simulations

    Science.gov (United States)

    Köllner, Thomas; Rossi, Maurice; Broer, Frauke; Boeck, Thomas

    2014-11-01

    A case of convection driven by chemical reactions is studied by linear stability theory and direct numerical simulations. In a plane aqueous layer of glucose, the methylene-blue-enabled catalytic oxidation of glucose produces heavier gluconic acid. As the oxygen is supplied through the top surface, the production of gluconic acid leads to an overturning instability. Our results complement earlier experimental and numerical work by Pons et al. First, we extend the model by including the top air layer with diffusive transport and Henry's law for the oxygen concentration at the interface to provide a more realistic oxygen boundary condition. Second, a linear stability analysis of the diffusive basic state in the layers is performed using an optimal perturbation approach. This method is appropriate for the unsteady basic state and determines the onset time of convection and the associated wavelength. Third, the nonlinear evolution is studied by the use of three-dimensional numerical simulations. Three typical parameters sets are explored in detail showing significant differences in pattern formation. One parameter set for which the flow is dominated by viscous forces, displays persistently growing convection cells. The other set with increased reaction rate displays a different flow regime marked by local chaotic plume emission. The simulated patterns are then compared to experimental observations.

  16. Chemoconvection patterns in the methylene-blue-glucose system: Weakly nonlinear analysis

    Science.gov (United States)

    Pons, A. J.; Sagués, F.; Bees, M. A.

    2004-12-01

    The oxidation of solutions of glucose with methylene-blue as a catalyst in basic media can induce hydrodynamic overturning instabilities, termed chemoconvection in recognition of their similarity to convective instabilities. The phenomenon is due to gluconic acid, the marginally dense product of the reaction, which gradually builds an unstable density profile. Experiments indicate that dominant pattern wavenumbers initially increase before gradually decreasing or can even oscillate for long times. Here, we perform a weakly nonlinear analysis for an established model of the system with simple kinetics, and show that the resulting amplitude equation is analogous to that obtained in convection with insulating walls. We show that the amplitude description predicts that dominant pattern wavenumbers should decrease in the long term, but does not reproduce the aforementioned increasing wavenumber behavior in the initial stages of pattern development. We hypothesize that this is due to horizontally homogeneous steady states not being attained before pattern onset. We show that the behavior can be explained using a combination of pseudo-steady-state linear and steady-state weakly nonlinear theories. The results obtained are in qualitative agreement with the analysis of experiments.

  17. Decolorization of Methylene Blue with TiO2 Sol via UV Irradiation Photocatalytic Degradation

    Directory of Open Access Journals (Sweden)

    Jun Yao

    2010-01-01

    Full Text Available TiO2 sol was prepared for the degradation of methylene blue (MB solution under ultraviolet (UV irradiation. The absorption spectra of MB indicated that the maximum wavelength, 663 nm, almost kept the same. The performance of 92.3% for color removal was reached after 160 min. The particle size of TiO2 sol was about 22.5 nm. X-ray diffraction showed that TiO2 consisted of a single anatase phase. The small size and anatase phase probably resulted in high photocatalytic activity of TiO2 sol. The degradation ratio decreased as the initial concentration of MB increased. The photodegradation efficiency decreased in the order of pH 2>pH 9>pH 7. Regarding catalyst load, the degradation increased with the mass of catalyst up to an amount of 1.5 g⋅L−1 then decreased as the mass continued to increase. The addition of H2O2 to TiO2 sol resulted in an increase on the degradation ratio.

  18. Photocatalytic degradation of methylene blue under UV light irradiation on prepared carbonaceous TiO2.

    Science.gov (United States)

    Ramli, Zatil Amali Che; Asim, Nilofar; Isahak, Wan N R W; Emdadi, Zeynab; Ahmad-Ludin, Norasikin; Yarmo, M Ambar; Sopian, K

    2014-01-01

    This study involves the investigation of altering the photocatalytic activity of TiO2 using composite materials. Three different forms of modified TiO2, namely, TiO2/activated carbon (AC), TiO2/carbon (C), and TiO2/PANi, were compared. The TiO2/carbon composite was obtained by pyrolysis of TiO2/PANi prepared by in situ polymerization method, while the TiO2/activated carbon (TiO2/AC) was obtained after treating TiO2/carbon with 1.0 M KOH solution, followed by calcination at a temperature of 450°C. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), thermogravimetric analysis (TG-DTA), Brunauer-Emmet-Teller (BET), and UV-Vis spectroscopy were used to characterize and evaluate the prepared samples. The specific surface area was determined to be in the following order: TiO2/AC > TiO2/C > TiO2/PANi > TiO2 (179 > 134 > 54 > 9 m(2) g(-1)). The evaluation of photocatalytic performance for the degradation of methylene blue under UV light irradiation was also of the same order, with 98 > 84.7 > 69% conversion rate, which is likely to be attributed to the porosity and synergistic effect in the prepared samples.

  19. Ag-ligand modified tungstovandates and their efficient catalysis degradation properties for methylene blue

    Science.gov (United States)

    Zheng, Ran; Zhang, Huixia; Liu, Yunping; Wang, Xiaoxiao; Han, Zhangang

    2017-02-01

    Two polytungstovandates [Ag(mbpy)2][Ag2(mbpy)3][VW5O19]·H2O (1) and [Ag(mbpy)]2[Ag(mbpy)2]4[VW12O40] (2) (mbpy =4,4‧-dimethyl-2,2‧-bipyridyl), had been hydrothermally synthesized and characterized by IR, TG, and single-crystal X-ray diffraction techniques. Single-crystal structural analysis revealed that the polyanionic clusters in two compounds are different: Lindqvist-type in 1 and α-Keggin-type in 2, respectively, while the cationic moieties in them are Ag-mbpy units. The experiments showed that this kind of hybrid crystal materials possesses more efficiently catalytic performance for the degradation of organic dye methylene blue (MB) in water solution under the UV irradiation. The significant degradation rate of MB can reach 89.9%, 94.9% by crystals 1 and 2 (40 mg) in the course of about 5 min.

  20. Twenty years of vasoplegic syndrome treatment in heart surgery. Methylene blue revised

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Barbosa Evora

    2015-02-01

    Full Text Available Objective: This study was conducted to reassess the concepts established over the past 20 years, in particular in the last 5 years, about the use of methylene blue in the treatment of vasoplegic syndrome in cardiac surgery. Methods: A wide literature review was carried out using the data extracted from: MEDLINE, SCOPUS and ISI WEB OF SCIENCE. Results: The reassessed and reaffirmed concepts were 1 MB is safe in the recommended doses (the lethal dose is 40 mg/kg; 2 MB does not cause endothelial dysfunction; 3 The MB effect appears in cases of NO up-regulation; 4 MB is not a vasoconstrictor, by blocking the cGMP pathway it releases the cAMP pathway, facilitating the norepinephrine vasoconstrictor effect; 5 The most used dosage is 2 mg/kg as IV bolus, followed by the same continuous infusion because plasma concentrations sharply decrease in the first 40 minutes; and 6 There is a possible "window of opportunity" for MB's effectiveness. In the last five years, major challenges were: 1 Observations about side effects; 2 The need for prophylactic and therapeutic guidelines, and; 3 The need for the establishment of the MB therapeutic window in humans. Conclusion: MB action to treat vasoplegic syndrome is time-dependent. Therefore, the great challenge is the need, for the establishment the MB therapeutic window in humans. This would be the first step towards a systematic guideline to be followed by possible multicenter studies.

  1. Methylene blue 1% solution on the prevention of intraperitoneal adhesion formation in a dog model

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    Marco Augusto Machado Silva

    Full Text Available Intraperitoneal adhesions usually are formed after abdominal surgeries and may cause technical difficulties during surgical intervention, chronic abdominal pain and severe obstructions of the gastrointestinal tract. The current study aimed to evaluate the efficacy of methylene blue (MB 1% solution on the prevention of intraperitoneal postsurgical adhesion formation in a canine surgical trauma model. Twenty bitches were submitted to falciform ligament resection, omentectomy, ovariohysterectomy and scarification of a colonic segment. Prior to abdominal closure, 10 bitches received 1mg kg-1 MB intraperitoneally (MB group and 10 bitches received no treatment (control group, CT. On the 15th postoperative day the bitches were submitted to laparoscopy to assess adhesions. The mean adhesion scores were 13.9 (±5.6 for MB group and 20.5 (±6.4 for the CT group (P=0,043. In conclusion, the 1% MB solution was efficient on the prevention of intraperitoneal postoperative adhesion formation in bitches, especially those involving the colonic serosa.

  2. Photodynamic effect of light-emitting diode light on cell growth inhibition induced by methylene blue

    Indian Academy of Sciences (India)

    Lílian S Peloi; Rafael R S Soares; Carlos E G Biondo; Vagner R Souza; Noboru Hioka; Elza Kimura

    2008-06-01

    The aim of this study was to propose the use of red light-emitting diode (LED) as an alternative light source for methylene blue (MB) photosensitizing effect in photodynamic therapy (PDT). Its effectiveness was tested against Staphylococcus aureus (ATCC 26923), Escherichia coli (ATCC 26922), Candida albicans (ATCC 90028) and Artemia salina. The maximum absorption of the LED lamps was at a wavelength of 663 nm, at intensities of 2, 4, 6 and 12 J.cm–2 for 10, 20, 30 and 60 min of exposure, respectively. Assays with and without LED exposure were carried out in plates containing MB at concentrations of 7 to 140.8 M for microorganisms and 13.35 to 668.5 M for microorganisms or microcrustaceans. The LED exposure induced more than 93.05%, 93.7% and 93.33% of growth inhibition for concentrations of 42.2 M for S. aureus (D-value=12.05 min) and 35.2 M for E. coli (D-value=11.51 min) and C. albicans (D-value=12.18 min), respectively after 20 min of exposure. LED exposure for 1 h increased the cytotoxic effect of MB against A. salina from 27% to 75%. Red LED is a promising light device for PDT that can effectively inhibit bacteria, yeast and microcrustacean growth.

  3. Synthesis of Polyurethanes Membranes from Rubber Seed Oil and Methylene Diphenyl Diisocyanates (MDI)

    Science.gov (United States)

    Marlina; Nurman, S.; Saleha, S.; Fitriani; Thanthawi, I.

    2017-03-01

    Rubber seed oil and methylene diphenyl diisocyanates (MDI) based polyurethane membrane has been prepared in this study. The main objective of this research is manufacture of polyurethane membranes from avocado seed oil, as a filter of this membrane use as a filter of metals from water such as mercury (Hg). In this study, the polyurethane membrane had been synthesized by varying compositions of rubber seed oil and MDI, with ratios of 10:0.2; 10:0.4; 10:0.6; 10:0.8; 10:1.0; 10:1.2; 10:1.4; 10:1.6; 10:1.8 and 10:2.0 (v/w) at 80°C and 170°C as polymerization and curing temperatures, respectively. Optimum polyurethane membrane was obtained at rubber seed oil: MDI 10: 0.8 v/w, it was dry, non-sticky, smooth and blackish brown. The membrane flux was 5,8307 L / m2.h.bar and rejection factor was 35,3015 %. The results of characterization indicated the formation of urethane bonds (NH at 3480 cm-1, C=O at 1620 cm-1, CN at 1374 cm-1, -OC-NH- at 1096 cm-1 and no -NCO at 2270 cm-1), the value of Tg was 55°C. The polyurethane membrane which treated at the optimum treatment conditions were used to the filter of metals from water such as mercury (Hg).

  4. Removal of methylene blue from aqueous solution by wood millet carbon optimization using response surface methodology

    Science.gov (United States)

    Ghaedi, Mehrorang; Kokhdan, Syamak Nasiri

    2015-02-01

    The use of cheep, non-toxic, safe and easily available adsorbent are efficient and recommended material and alternative to the current expensive substance for pollutant removal from wastewater. The activated carbon prepared from wood waste of local tree (millet) extensively was applied for quantitative removal of methylene blue (MB), while simply. It was used to re-used after heating and washing with alkaline solution of ethanol. This new adsorbent was characterized by using BET surface area measurement, FT-IR, pH determination at zero point of charge (pHZPC) and Boehm titration method. Response surface methodology (RSM) by at least the number of experiments main and interaction of experimental conditions such as pH of solution, contact time, initial dye concentration and adsorbent dosage was optimized and set as pH 7, contact time 18 min, initial dye concentration 20 ppm and 0.2 g of adsorbent. It was found that variable such as pH and amount of adsorbent as solely or combination effects seriously affect the removal percentage. The fitting experimental data with conventional models reveal the applicability of isotherm models Langmuir model for their well presentation and description and Kinetic real rate of adsorption at most conditions efficiently can be represented pseudo-second order, and intra-particle diffusion. It novel material is good candidate for removal of huge amount of MB (20 ppm) in short time (18 min) by consumption of small amount (0.2 g).

  5. Evaluation of Photocatalytic Active Coatings on Sintered Glass Tubes by Methylene Blue

    Directory of Open Access Journals (Sweden)

    Colin Awungacha Lekelefac

    2013-01-01

    Full Text Available A comparative study between ten different photocatalytic active coatings was done. The effectiveness and photocatalytic activity of the coatings were studied by degradation experiments of methylene blue (MB dye under UV light illumination. The reactor design consisting of sintered glass packed in a borosilicate tube placed between two planar dielectric barrier discharge lamps (Osram Planon is reported for the first time. The coatings consisted of either titania, silica, or zinc on sintered borosilicate glass. The advantage of sol-gel in catalyst preparation was exploited to combine catalyst to act as cocatalyst. TiO2-P25 widely applied in suspension systems was effectively immobilized on sintered glass support with the aid of tetraethylorthosilicate (TEOS solution which acted as support material. Results indicated that TiO2-P25+SiO2, TiO2-P25+SiO2+Pt, and TiOSO4_30,6wt% films showed highest degradation rates close to 100% after 90 min illumination with degradation rates exceeding 50% after 30 minutes. TTIP+Pt showed lowest degradation rate.

  6. Methylene blue biosorption by pericarp of corn, alfalfa, and agave bagasse wastes.

    Science.gov (United States)

    Rosas-Castor, José M; Garza-González, María T; García-Reyes, Refugio B; Soto-Regalado, Eduardo; Cerino-Córdova, Felipe J; García-González, Alcione; Loredo-Medrano, José A

    2014-01-01

    The presence of dyes in effluent is a matter of concern due to their toxicologic and aesthetical effects. In this research, locally available agro-industrial wastes (Zea mays pericarp, ZMP; Agave tequilana bagasse, ATB; and Medicago sativa waste, MSW) were used as alternative low-cost adsorbents for the removal of methylene blue (MB) from aqueous solutions. The adsorbents were characterized physically and chemically by Fourier transform infrared, scanning electron microscopy, potentiometric titrations, and N2 physisorption. MB adsorption experiments were carried out in batch systems and experimental data were used to calculate the adsorption isotherm model parameters (Langmuir, Freundlich, and Temkin) and the adsorption kinetic model parameters (pseudo-first- and pseudo-second-order models). MB-loaded biosorbents were desorbed with deionized water, ethanol (10% and 50% v/v), hydrochloric acid (0.01 and 0.05 N), and sodium hydroxide (0.1 N) at room temperature, and the best eluent was used in various adsorption-desorption cycles. The selected agricultural wastes can be considered as promising adsorbents for dye uptake from water since they exhibit considerable MB adsorption capacity (MSW 202.6 mg g(-1), ATB 156.2mg g(-1), and ZMP 110.9mg g(-1)), but it is lower than that reported for activated carbon; however, the biosorbents show higher adsorption rate than powdered activated carbon. Furthermore, the adsorbents can be economically regenerated with HCl solutions and reused for seven adsorption-desorption cycles.

  7. Removal of basic dye (methylene blue) from wastewaters utilizing beer brewery waste

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, W.-T. [Graduate Institute of Bioresources, National Pingtung University of Science and Technology, Pingtung 912, Taiwan (China)], E-mail: wttsai@mail.npust.edu.tw; Hsu, H.-C.; Su, T.-Y.; Lin, K.-Y.; Lin, C.-M. [Department of Environmental Engineering and Science, Chia Nan University of Pharmacy and Science, Tainan 717, Taiwan (China)

    2008-06-15

    In the work, the beer brewery waste has been shown to be a low-cost adsorbent for the removal of basic dye from the aqueous solution as compared to its precursor (i.e., diatomite) based on its physical and chemical characterizations including surface area, pore volume, scanning electron microscopy (SEM), and non-mineral elemental analyses. The pore properties of this waste were significantly larger than those of its raw material, reflecting that the trapped organic matrices contained in the waste probably provided additional adsorption sites and/or adsorption area. The results of preliminary adsorption kinetics showed that the diatomite waste could be directly used as a potential adsorbent for removal of methylene blue on the basis of its adsorption-biosorption mechanisms. The adsorption parameters thus obtained from the pseudo-second-order model were in accordance with their pore properties. From the results of adsorption isotherm at 298 K and the applicability examinations in treating industrial wastewater containing basic dye, it was further found that the adsorption capacities of diatomite waste were superior to those of diatomite, which were also in good agreement with their corresponding physical properties. From the results mentioned above, it is feasible to utilize the food-processing waste for removing dye from the industrial dying wastewater.

  8. Reversal by methylene blue of tetanic fade induced in cats by nitric oxide

    Directory of Open Access Journals (Sweden)

    C.R. Ambiel

    1998-03-01

    Full Text Available Previous data from our laboratory have indicated that nitric oxide (NO acting at the presynaptic level increases the amplitude of muscular contraction (AMC of the phrenic-diaphragm preparations isolated from indirectly stimulated rats, but, by acting at the postsynaptic level, it reduces the AMC when the preparations are directly stimulated. In the present study we investigated the effects induced by NO when tetanic frequencies of stimulation were applied to in vivo preparations (sciatic nerve-anterior tibial muscle of the cat. Intra-arterial injection of NO (0.75-1.5 mg/kg induced a dose-dependent increase in the Wedensky inhibition produced by high frequencies of stimulation applied to the motor nerve. Intra-arterial administration of 7.2 µg/kg methylene blue did not produce any change in AMC at low frequencies of nerve stimulation (0.2 Hz, but antagonized the NO-induced Wedensky inhibition. The experimental data suggest that NO-induced Wedensky inhibition may be mediated by the guanylate cyclase-cGMP pathway

  9. Spectroscopic studies of the interaction between methylene blue and G-quadruplex

    Institute of Scientific and Technical Information of China (English)

    SUN Hongxia; XIANG Junfeng; ZHANG Yazhou; XU Guangzhi; XU Lianghua; TANG Yalin

    2006-01-01

    G-rich single-stranded DNA (5'-TTAG-GG-3') adopted a G-quadruplex structure in buffer containing potassium ions. The spectroscopic feature and the interaction between methylene blue and G-quadruplex have been investigated by circular dichroism, and nuclear magnetic resonance spectroscopy. The UV-Vis absorption and fluorescence spectral results show that the fluorescence behavior of MB by single-stranded DNA fits Stern-Volmer static quenching equation very well and they formed 1:1 complexes; dimeric G-quadruplexes were bound to MB with 1:1 or 2:1, and their equilibrium constants were 1.047×105 and 8.79×104 L/mol, respectively.Based on the above results and 1H-NMR spectral data, one may conclude that MB stacked either the terminal tetrads to form 1:1 complexes or between two terminal tetrads of G-quadruplexes to form 1:2 sandwich complexes with G-qudruplexes.

  10. Probing molecular interactions with methylene blue derivatized self-assembled monolayers

    Directory of Open Access Journals (Sweden)

    Eleni Koutsoumpeli

    2015-12-01

    Full Text Available The emergence of stratified and personalised medicine and the associated need for highly multiplexed detection strategies are driving the development of innovative sensor technology. Electronic immunosensor arrays capable of label-free and highly parallel monitoring of ligand binding have emerged as a particularly promising technology capable of meeting these new diagnostic challenges. In this study, we present an approach for interrogating molecular interactions electronically using redox active molecular monolayers. Specifically, we have synthesised self-assembled molecular monolayers assembled from long-chain alkanethiols (LCAT incorporating oligoethyleneglycol (OEG linkers that can be derivatized with a range of functional groups, including the redox active molecule methylene blue. Critically, we show that the electron transport properties of this redox-active monolayer are highly sensitive to the electrochemical environment, including the local concentration of protons and the electrostatic potential at the plane of electron transfer. Using a combination of cyclic voltammetry and QCM-D to study in detail the behaviour of the monolayer during functionalisation and analyte binding, we demonstrate that these redox properties can be exploited for the electrochemical sensing of molecular interactions (biotin–avidin in our case on SAMs. Given the versatility of LCAT-OEG monolayers, in terms of linker lengths, choice of functional group, and ability to create mixed component layers and the straight-forward assembly of mixed SAMs of high quality, our electrochemical sensing approach forms an excellent and generic label-free platform for probing a wide range of molecular interactions.

  11. Control of burn wound sepsis in rats by methylene blue-mediated photodynamic treatment

    Science.gov (United States)

    Hasegawa, Hiroyuki; Sato, Shunichi; Kawauchi, Satoko; Saitoh, Daizoh; Shinomiya, Nariyoshi; Ashida, Hiroshi; Terakawa, Mitsuhiro

    2012-02-01

    Control of wound sepsis is an important challenge in traumatology. However, increase in the drug-resistant bacteria makes this challenge considerably difficult in recent years. In this study, we attempted to control burn wound sepsis in rats by photodynamic treatment, which has been reported to be effective against some drug-resistant bacteria. A 20% TBSA (total body surface area) full-thickness burn was made in rat dorsal skin, and five days after injury, a suspension of P. aeruginosa was applied to the wound surface. At 30 min after infection, a methylene blue (MB) solution was applied to the wound surface; 5 min afterwards, the wound was illuminated with a 665-nm light emitting diode (LED) array for 10 min. This treatment (application of MB and illumination) was repeated 3 times successively. The averaged light intensity on the wound surface was 3.3 mW/cm2, the corresponding total light dose being 5.9 J/cm2. One week after injury, the numbers of bacteria in the blood and liver were counted by colony forming assay. In the liver, the number of bacteria of the treated group was significantly lower than that of the sham control group without photodynamic treatment. In the blood, no bacteria were detected in the treated group, while a certain amount of bacteria was detected in the control group. These results demonstrate the efficacy of MB-mediated PDT with a red LED array to control burn wound sepsis.

  12. Facile fabrication of magnetic carboxymethyl starch/poly(vinyl alcohol) composite gel for methylene blue removal.

    Science.gov (United States)

    Gong, Guisheng; Zhang, Faai; Cheng, Zehong; Zhou, Li

    2015-11-01

    This study presents a simple method to fabricate magnetic carboxymethyl starch/poly(vinyl alcohol) (mCMS/PVA) composite gel. The obtained mCMS/PVA was characterized by Fourier transform infrared (FTIR) spectra, vibrating-sample magnetometer (VSM) and scanning electron microscopy (SEM) measurements. The application of mCMS/PVA as an adsorbent for removal of cationic methylene blue (MB) dye from water was investigated. Benefiting from the combined merits of carboxymethyl starch and magnetic gel, the mCMS/PVA simultaneously exhibited excellent adsorption property toward MB and convenient magnetic separation capability. The effects of initial dye concentration, contact time, pH and ionic strength on the adsorption performance of mCMS/PVA adsorbent were investigated systematically. The adsorption process of mCMS/PVA for MB fitted pseudo-second-order model and Freundlich isotherm. Moreover, desorption experiments revealed that the mCMS/PVA adsorbent could be well regenerated in ethanol solution without obvious compromise of removal efficiency even after eight cycles of desorption/adsorption. Considering the facile fabrication process and robust adsorption performance, the mCMS/PVA composite gel has great potential as a low cost adsorbent for environmental decontamination.

  13. A sensitive resveratrol assay with a simple probe methylene blue by resonance light scattering technique

    Science.gov (United States)

    Xiang, Haiyan; Dai, Kaijin; Luo, Qizhi; Duan, Wenjun; Xie, Yang

    2011-01-01

    A novel resonance light scattering (RLS) method was developed for the determination of resveratrol based on the interaction between resveratrol and methylene blue (MB). It was found that at pH 8.69, the weak RLS intensity of MB was remarkably enhanced by the addition of trace amount of resveratrol with the maximum peak located at 385.0 nm. Under the optimum conditions, a good linear relationship between the enhanced RLS intensities and the concentrations of resveratrol was obtained over the range of 2.0-14.0 μg ml -1 with the detection limit (3 σ) of 0.63 μg ml -1. The results of the analysis of resveratrol in synthetic samples and human urine are satisfactory, which showed it may provide a more sensitive, convenient, rapid and reproducible method for the detection of resveratrol, especially in biological and pharmaceutical field. In this work, the characteristics of RLS, absorption and fluorescence spectra of the resveratrol-MB system, the influencing factors and the optimum conditions of the reaction were investigated.

  14. Photodegradation of Methylene Blue by TiO2-Fe3O4-Bentonite Magnetic Nanocomposite

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2015-01-01

    Full Text Available Fe3O4-bentonite nanoparticles have been prepared by a coprecipitation technique under a nitrogen atmosphere. An aqueous suspension of bentonite was first modified with FeCl2 and FeCl3. TiO2 was then loaded onto the surface of the Fe3O4-bentonite by a sol-gel method. After sufficient drying, the colloidal solution was placed in a muffle furnace at 773 K to obtain the TiO2-Fe3O4-bentonite composite. The material has been characterized by scanning electron microscopy (SEM, X-ray diffraction (XRD analysis, and vibrating sample magnetometry (VSM. Morphological observation showed that Fe3O4 and TiO2 nanoparticles had been adsorbed on the surface of bentonite nanoneedles. The material was then applied for the photodegradation of the azo dye methylene blue (MB. It was found that the removal efficiency of MB exceeded 90% under UV illumination, and that only a 20% mass loss was incurred after six cycles. The composite material thus showed good photocatalytic performance and recycling properties.

  15. Anxiolytic effect of methylene blue microinjected into the dorsal periaqueductal gray matter

    Directory of Open Access Journals (Sweden)

    de-Oliveira R.W.

    1999-01-01

    Full Text Available The dorsal periaqueductal gray (DPAG has been implicated in the behavioral and autonomic expression of defensive reactions. Several results suggest that, along with GABA, glutamate and serotonin, nitric oxide (NO may play a role in defense reactions mediated by this region. To further investigate this possibility we microinjected methylene blue (MB; 10, 30 or 100 nmol/0.5 µl into the DPAG of rats submitted to the elevated plus-maze test, an animal model of anxiety. MB has been used as an inhibitor of soluble guanylate cyclase (sGC to demonstrate cGMP-mediated processes, and there is evidence that NO may exert its biological effects by binding to the heme part of guanylate cyclase, causing an increase in cGMP levels. The results showed that MB (30 nmol significantly increased the percent of time spent in the open arms (saline = 11.57 ± 1.54, MB = 18.5 ± 2.45, P<0.05 and tended to do the same with the percentage of open arm entries (saline = 25.8 ± 1.97, MB = 33.77 ± 3.07, P<0.10, but did not change the number of enclosed arm entries. The dose-response curve, however, had an inverted U shape. These results indicate that MB, within a limited dose range, has anxiolytic properties when microinjected into the DPAG.

  16. Adsorption of Methylene Blue, Bromophenol Blue, and Coomassie Brilliant Blue by α-chitin nanoparticles

    Directory of Open Access Journals (Sweden)

    Solairaj Dhananasekaran

    2016-01-01

    Full Text Available Expelling of dyestuff into water resource system causes major thread to the environment. Adsorption is the cost effective and potential method to remove the dyes from the effluents. Therefore, an attempt was made to study the adsorption of dyestuff (Methylene Blue (MB, Bromophenol Blue (BPB and Coomassie Brilliant Blue (CBB by α-chitin nanoparticles (CNP prepared from Penaeus monodon (Fabricius, 1798 shell waste. On contrary to the most recognizable adsorption studies using chitin, this is the first study using unique nanoparticles of ⩽50 nm used for the dye adsorption process. The results showed that the adsorption process increased with increase in the concentration of CNP, contact time and temperature with the dyestuff, whereas the adsorption process decreased with increase in the initial dye concentration and strong acidic pH. The results from Fourier transform infrared (FTIR spectroscopy confirmed that the interaction between dyestuff and CNP involved physical adsorption. The adsorption process obeys Langmuir isotherm (R2 values were 0.992, 0.999 and 0.992 for MB, BPB and CBB, and RL value lies between 0 and 1 for all the three dyes and pseudo second order kinetics (R2 values were 0.996, 0.999 and 0.996 for MB, BPB and CBB more effectively. The isotherm and kinetic models confirmed that CNP can be used as a suitable adsorbent material for the removal of dyestuff from effluents.

  17. Heterogeneous photodegradation of methylene blue with iron and tea or coffee polyphenols in aqueous solutions.

    Science.gov (United States)

    Morikawa, Claudio Kendi; Shinohara, Makoto

    2016-01-01

    Recently, we developed two new Fenton catalysts using iron (Fe) and spent tea leaves or coffee grounds as raw material. In this study, Fe-to-tea or Fe-to-coffee polyphenol complexes were successfully tested as heterogeneous photo-Fenton catalysts. The photodegradation efficiency of methylene blue solutions with Fe-to-polyphenol complexes was higher than that of homogeneous iron salts in the photo-Fenton process. Furthermore, the tested Fe-to-polyphenol complexes could be reused by simply adding H2O2 to the solutions. After three sequential additions of H2O2, the conventional catalysts FeCl2·4H2O and FeCl3 removed only 16.6% and 53.6% of the dye, while the catalysts made using spent coffee grounds and tea leaves removed 94.4% and 96.0% of the dye, respectively. These results showed that the complexes formed between Fe and chlorogenic acid, caffeic acid, gallic acid and catechin, which are the main polyphenols in tea and coffee, can be used to improve the photo-Fenton process.

  18. Photoelectrocatalytic determination of NADH in a flow injection system with electropolymerized methylene blue

    Energy Technology Data Exchange (ETDEWEB)

    Dilgin, Yusuf, E-mail: ydilgin@yahoo.co [Canakkale Onsekiz Mart University, Science and Art Faculty, Department of Chemistry, TR-17100 Canakkale (Turkey); Dilgin, Didem Giray [Canakkale Onsekiz Mart University, Biga Vocational College, TR-17200 Biga Canakkale (Turkey); Ege University, Science Faculty, Department of Chemistry, TR-35100 Bornova/Izmir (Turkey); Dursun, Zekerya; Goekcel, H. Ismet [Ege University, Science Faculty, Department of Chemistry, TR-35100 Bornova/Izmir (Turkey); Gligor, Delia [Department of Environmental Physics, Chemistry and Engineering, ' Babes-Bolyai' University, 30 Fantanele St., 400294 Cluj-Napoca (Romania); Bayrak, Burcu; Ertek, Bensu [Canakkale Onsekiz Mart University, Science and Art Faculty, Department of Chemistry, TR-17100 Canakkale (Turkey)

    2011-01-01

    It was firstly described that a glassy carbon electrode electropolymerized with methylene blue shows an efficient photoelectrocatalytic activity towards NADH oxidation in a phosphate buffer solution (pH 7.0). In order to perform the photoelectrocatalytic determination of NADH in a flow injection analysis (FIA) system, a home-made flow electrochemical cell with a suitable transparent window for the irradiation of the electrode surface was constructed. The currents obtained from the photoamperometric measurements in the FIA system at optimum conditions (flow rate of carrier solution, 1.3 mL min{sup -1}; transmission tubing length, 10 cm; injection volume, 100 {mu}L; and constant applied potential, +150 mV vs. Ag/AgCl) were linearly dependent on the NADH concentration and linear calibration curves were obtained in the range of 1.0 x 10{sup -7}-2.0 x 10{sup -4} M. The detection limit was found to be 4.0 x 10{sup -8} M for photoamperometric determination of NADH.

  19. Activated carbon coated palygorskite as adsorbent by activation and its adsorption for methylene blue.

    Science.gov (United States)

    Zhang, Xianlong; Cheng, Liping; Wu, Xueping; Tang, Yingzhao; Wu, Yucheng

    2015-07-01

    An activation process for developing the surface and porous structure of palygorskite/carbon (PG/C) nanocomposite using ZnCl2 as activating agent was investigated. The obtained activated PG/C was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (SEM), and Brunauer-Emmett-Teller analysis (BET) techniques. The effects of activation conditions were examined, including activation temperature and impregnation ratio. With increased temperature and impregnation ratio, the collapse of the palygorskite crystal structure was found to accelerate and the carbon coated on the surface underwent further carbonization. XRD and SEM data confirmed that the palygorskite structure was destroyed and the carbon structure was developed during activation. The presence of the characteristic absorption peaks of CC and C-H vibrations in the FTIR spectra suggested the occurrence of aromatization. The BET surface area improved by more than 11-fold (1201 m2/g for activated PG/C vs. 106 m2/g for PG/C) after activation, and the material appeared to be mainly microporous. The maximum adsorption capacity of methylene blue onto the activated PG/C reached 351 mg/g. The activated PG/C demonstrated better compressive strength than activated carbon without palygorskite clay.

  20. Removal of methylene blue from aqueous solution by a solvothermal-synthesized graphene/magnetite composite.

    Science.gov (United States)

    Ai, Lunhong; Zhang, Chunying; Chen, Zhonglan

    2011-09-15

    In this study, we have demonstrated a facile one-step solvothermal method for the synthesis of the graphene nanosheet (GNS)/magnetite (Fe(3)O(4)) composite. During the solvothermal treatment, in situ conversion of FeCl(3) to Fe(3)O(4) and simultaneous reduction of graphene oxide (GO) into graphene in ethylene glycol solution were achieved. Electron microscopy study suggests the Fe(3)O(4) spheres with a size of about 200 nm are uniformly distributed and firmly anchored on the wrinkled graphene layers with a high density. The resulting GNS/Fe(3)O(4) composite shows extraordinary adsorption capacity and fast adsorption rates for removal of organic dye, methylene blue (MB), in water. The adsorption kinetics, isotherms and thermodynamics were investigated in detail to reveal that the kinetics and equilibrium adsorptions are well-described by pseudo-second-order kinetic and Langmuir isotherm model, respectively. The thermodynamic parameters reveal that the adsorption process is spontaneous and endothermic in nature. This study shows that the as-prepared GNS/Fe(3)O(4) composite could be utilized as an efficient, magnetically separable adsorbent for the environmental cleanup.

  1. Investigation on physical properties of L-alanine: An effect of Methylene blue dye

    Science.gov (United States)

    Shkir, Mohd.; Yahia, I. S.; Al-Qahtani, A. M. A.; Ganesh, V.; AlFaify, S.

    2017-03-01

    In the present investigation, a bulk size (35 mm × 25 mm × 15 mm) single crystal of 0.1 wt% Methylene blue dye (MLB) added L-alanine is grown at room temperature using solution technique for the first time. The L-alanine crystals with higher concentrations of dye (0.5 and 1 wt%) were also grown. Solubility study was performed at different temperatures. Structural, vibrational and good quality was inveterate by powder XRD, FT-Raman and SEM analyses. High transmittance in dyed crystals was confirmed. The presence of MLB dye was confirmed by an absorption band centered at 650 nm. Optical band gap was calculated for pure and dyed L-alanine crystals and found to be 5.45 and 4.49 eV respectively. Photoluminescence intensity of UV-A emission band centered at 332 nm was found to be enhanced due to the presence of dye. The dielectric measurement was done in the wide frequency range. Furthermore, the third order nonlinear optical parameters are enhanced in dyed L-alanine crystals determined by Z-scan technique.

  2. Use of rice husk for the removal of methylene blue in fixed-bed columns

    Directory of Open Access Journals (Sweden)

    Yurany A. Villada-Villada

    2014-08-01

    Full Text Available This work shows the use of rice husk in the removal of cationic dye methylene blue on continuous system. A factorial design 23 with center points and random distribution was implemented to evaluate the correlation of the experimental factors in the adsorption process. The considered variables were pH, particle size, salt presence, flow rate, dye initial concentration, and bed depth. The samples were analyzed in defined time intervals. The amount of removed dye was quantified by UV spectroscopy - Visible. Adams-Bohart, Thomas and BDST (Bed-depht/service time analysis models were used to predict the breakthrough curves using non-linear regression and establish the characteristic parameters of the process. It was found that the transference of dye toward the adsorbent is favored by a basic pH, a small particle size, low flow rate and dye concentration, and high bed depth. The design of experiments established that the initial dye concentration and the bed depth were the most significant factors. Regarding the models, the Thomas provided the best fit to describe the breakthrough curves in experimental conditions and Adams-Bohart was found suitable for dynamic behavior limited to the initial part. Finally, BDST model exhibited a good correlation and allowed to establish that bed depth is a determinant factor for scaling process.

  3. Studies on the Adsorption of Amino Methylene Phosphonic Acid Resin for Holmium(Ⅲ)

    Institute of Scientific and Technical Information of China (English)

    吴香梅; 熊春华; 姚彩萍

    2003-01-01

    The adsorption behavior and mechanism of a novel chelate resin, amino methylene phosphonic acid resin (APAR) for Ho(Ⅲ) were investigated. The statically saturated adsorption capacity is 258 mg·g-1 resin at 298 K in Hac-NaAc medium. The Ho(Ⅲ) adsorbed on APAR can be repeatedly eluted by 3.0 mol·L-1 HCl and the elution percentage is as high as 95.8%. The resin can be regenerated and reused without apparent decrease in adsorption capacity. The apparent adsorption rate constant is k298=1.14×10-5 s-1. The adsorption behavior of APAR for Ho(Ⅲ) obeys the Freundlich isotherm. The ther modynamic adsorption parameter, enthalpy change ΔH of APAR for Ho(Ⅲ) is 11 .4 kJ·mol-1. The apparent activation energy is Ea=15.8 kJ·mol- 1. The molar coordination ratio of the functional group of APAR to Ho(Ⅲ) is a bout 2∶1. The adsorption mechanism of APAR for Ho(Ⅲ) was examined by using chemical method and IR spectrometry.

  4. SUV measurement of normal vertebrae using SPECT/CT with Tc-99m methylene diphosphonate

    Science.gov (United States)

    Kaneta, Tomohiro; Ogawa, Matsuyoshi; Daisaki, Hiromitsu; Nawata, Shintaro; Yoshida, Keisuke; Inoue, Tomio

    2016-01-01

    The purpose of this study is to perform quantitative measurement based on the standardized uptake value (SUV) of the uptake of Tc-99m methylene diphosphonate (MDP) in the normal vertebrae using a single photon emission tomography (SPECT)/computed tomography (CT) scanner. A retrospective study of patients with cancer or joint disorders was performed. We acquired data for a group of 29 patients (8 women and 21 men; mean age, 68.2 ± 6.7 years; age range, 44-87 years) undergoing bone SPECT/CT scans with Tc-99m MDP between September and October 2015. Various SUVs were calculated based on body-weight, lean-body-weight (lbw), Japanese lean-body-weight (jlbw) and Japanese bone-mineral-content (jbmc). SUVs of normal vertebrae showed a wide range of values. Among these, the maximum body-weight based SUV showed the lowest coefficient of variation. The SUVs also showed relatively small intra-subject variability. In addition, all SUVs showed moderate and significant correlation with height. Moreover, lbw-, jlbw-, and jbmc-based SUVs of men were significantly higher than those of women. In conclusions, SUVs of normal vertebrae showed a relatively large inter-individual variability and small intra-individual variability. As a quantitative imaging biomarker, SUVs might require standardization with adequate reference data for the same subject to minimize variability. PMID:27766184

  5. Kinetics, Equilibrium, and Thermodynamic Studies on Adsorption of Methylene Blue by Carbonized Plant Leaf Powder

    Directory of Open Access Journals (Sweden)

    V. Gunasekar

    2013-01-01

    Full Text Available Carbon synthesized from plant leaf powder was employed for the adsorption of methylene blue from aqueous effluent. Effects of pH (2, 4, 6, 8, and 9, dye concentration (50, 100, 150, and 200 mg/dm3, adsorbent dosage (0.5, 1.0, 1.5, and 2.0 g/dm3, and temperature (303, 313, and 323 K were studied. The process followed pseudo-second-order kinetics. Equilibrium data was examined with Langmuir and Freundlich isotherm models and Langmuir model was found to be the best fitting model with high R2 and low chi2 values. Langmuir monolayer adsorption capacity of the adsorbent was found to be 61.22 mg/g. From the thermodynamic analysis, ΔH, ΔG, and ΔS values for the adsorption of MB onto the plant leaf carbon were found out. From the values of free energy change, the process was found out to be feasible process. From the magnitude of ΔH, the process was found to be endothermic physisorption.

  6. A high sensitivity field effect transistor biosensor for methylene blue detection utilize graphene oxide nanoribbon.

    Science.gov (United States)

    Lin, Ting-Chun; Li, Yan-Sheng; Chiang, Wei-Hung; Pei, Zingway

    2017-03-15

    In this work, we developed a field effect transistor (FET) biosensor utilizing solution-processed graphene oxide nanoribbon (GONR) for methylene blue (MB) sensing. MB is a unique material; one of its crucial applications is as a marker in the detection of biomaterials. Therefore, a highly sensitive biosensor with a low detection limit that can be fabricated simply in a noncomplex detection scheme is desirable. GONR is made by unzipping multiwall carbon nanotubes, which can be mass-produced at low temperature. The GONR-FET biosensor demonstrated a sensitivity of 12.5μA/mM (determined according to the drain current difference caused by the MB concentration change). The Raman spectra indicate that the materials quality of the GONR and the domain size for the C=C sp(2) bonding were both improved after MB detection. X-ray photoelectron spectroscopy revealed that the hydroxyl groups on the GONR were removed by the reductive MB. According to XPS and Raman, the positive charge is proposed to transfer from MB to GONR during sensing. This transfer causes charge in-neutrality in the GONR which is compensated by releasing •OH functional groups. With high sensitivity, a low detection limit, and a simple device structure, the GONR-FET sensor is suitable for sensing biomaterials.

  7. The preparation of novel adsorbent materials with efficient adsorption performance for both chromium and methylene blue.

    Science.gov (United States)

    Li, Leilei; Liu, Feng; Duan, Huimin; Wang, Xiaojiao; Li, Jianbo; Wang, Yanhui; Luo, Chuannan

    2016-05-01

    The hydroxy-functionalized ionic liquids (ILs) modified with magnetic chitosan/grapheneoxide (MG-ILs-OH) were synthesized. The surface morphology of MG-ILs-OH was characterized by transmission electron microscopy, X-ray diffraction, thermo gravimetric analysis and Fourier transform infrared spectroscopy techniques. It was found that the adsorption kinetics is well fitted by a pseudo-second-order model and the adsorption isotherms agree well with the Langmuir model, and the MG-ILs-OH could be repeatedly used by simple treatment. The results showed that the addition of ILs-OH can largely increase the adsorption sites (hydroxy and amino groups) and adsorption properties. The MG-ILs-OH were used as adsorbent for the removal of methylene blue (MB) and Cr(VI) from simulated wastewater with a fast solid-liquid separation in the presence of external magnetic field. The maximum obtained adsorption capacities of MB and Cr(VI) were 243.31 and 107.99 mg/g, respectively. The application of MG-ILs-OH could effectively solve the problem that the adsorbent only adsorb similar adsorbate.

  8. Methylene Blue Doped Films of Wool Keratin with Antimicrobial Photodynamic Activity.

    Science.gov (United States)

    Aluigi, Annalisa; Sotgiu, Giovanna; Torreggiani, Armida; Guerrini, Andrea; Orlandi, Viviana T; Corticelli, Franco; Varchi, Greta

    2015-08-12

    In this work, keratin films doped with different amounts of methylene blue (MB) were developed in order to prepare new biodegradable and biocompatible materials for tissue engineering and wound healing, able to exert antimicrobial photodynamic activity upon irradiation with visible light. Preliminary results indicated that the swelling ratio, as well as the MB release, increases by increasing the pH. Moreover, the generation of reactive oxygen species (ROS) and singlet oxygen can be easily triggered and controlled by a fine-tuning of the irradiation time and MB concentration in the films. As concerns the photodynamic effects on keratin, the ROS attack does not induce any significant photodegradation on the protein, even if a slight photo-oxidation of sulfonated amino acids occurs. Finally, the film with the highest MB concentration (400 μg per gram of keratin) displays a significant photobactericidal activity against Staphylococcus aureus with a bacterial reduction that increases by increasing the irradiation time. In particular, the irradiation of KFMB400 film incubated with S. aureus at a concentration of 10(8) cfu mL(-1) determined the 99.9% killing rate and the killing effect increased proportionally with irradiation time.

  9. Adsorption of methylene blue on biochar microparticles derived from different waste materials.

    Science.gov (United States)

    Lonappan, Linson; Rouissi, Tarek; Das, Ratul Kumar; Brar, Satinder K; Ramirez, Antonio Avalos; Verma, Mausam; Surampalli, Rao Y; Valero, José R

    2016-03-01

    Biochar microparticles were prepared from three different types of biochar, derived from waste materials, such as pine wood (BC-PW), pig manure (BC-PM) and cardboard (BC-PD) under various pyrolysis conditions. The microparticles were prepared by dry grinding and sequential sieving through various ASTM sieves. Particle size and specific surface area were analyzed using laser particle size analyzer. The particles were further characterized using scanning electron microscope (SEM). The adsorption capacity of each class of adsorbent was determined by methylene blue adsorption tests in comparison with commercially available activated carbon. Experimental results showed that dye adsorption increased with initial concentration of the adsorbate and biochar dosage. Biochar microparticles prepared from different sources exhibited improvement in adsorption capacity (7.8±0.5 mg g(-1) to 25±1.3 mg g(-1)) in comparison with raw biochar and commercially available activated carbon. The adsorption capacity varied with source material and method of production of biochar. The maximum adsorption capacity was 25 mg g(-1) for BC-PM microparticles at 25°C for an adsorbate concentration of 500 mg L(-1) in comparison with 48.30±3.6 mg g(-1) for activated carbon. The equilibrium adsorption data were best described by Langmuir model for BC-PM and BC-PD and Freundlich model for BC-PW.

  10. Adsorption of methylene blue on an agro-waste oiltea shell with and without fungal treatment

    Science.gov (United States)

    Liu, Jiayang; Li, Enzhong; You, Xiaojuan; Hu, Changwei; Huang, Qingguo

    2016-12-01

    A lignocellulosic waste oiltea shell (OTS) was evaluated as an inexpensive sorbent to remove methylene blue (MB) from aqueous solution. Fungal treatment of OTS increased the MB adsorption by modifying the physicochemical properties of OTS and simultaneously produced laccase as a beneficial co-product. Without fungal treatment, the maximum amount of adsorption (qm) of MB by OTS was 64.4 mg/g, whereas the treatment with fungus Pycnoporus sp. and Trametes versicolor increased qm up to 72.5 mg/g and 85.7 mg/g, respectively. This is because of the improved surface area and pore sizes as well as altered chemical compositions. The equilibrium sorption data for OTS both with and without treatment fitted to the Langmuir model, and the sorption rate data well fitted to the pseudo second-order kinetic model. The changes in free energy (ΔG°) and separation factor (RL) indicated that the sorption was spontaneous and favorable. Scanning electron microscopy and Fourier transform infrared spectroscopy showed the changes in the surface morphology and functional groups of OTS after fungal treatment. The agro-waste OTS could be utilized as a low-cost adsorbent for efficient dye removal, and fungal treatment can serve as a mild and clean technique to increase the adsorptive capacity of OTS.

  11. Photophysical and antibacterial properties of complex systems based on smectite, a cationic surfactant and methylene blue.

    Science.gov (United States)

    Donauerová, Alena; Bujdák, Juraj; Smolinská, Miroslava; Bujdáková, Helena

    2015-10-01

    Solid or colloidal materials with embedded photosensitizers are promising agents from the medical or environmental perspective, where the direct use of photoactive solutions appears to be problematic. Colloids based on layered silicates of the saponite (Sap) and montmorillonite (Mon) type, including those modified with dodecylammonium cations (C12) and photosensitizer--methylene blue (MB) were studied. Two representatives of bacteria, namely Enterobacter cloacae and Escherichia coli, were selected for this work. A spectral study showed that MB solutions and also colloids with Sap including C12 exhibited the highest photoactivities. The antimicrobial properties of the smectite colloids were not directly linked to the photoactivity of the adsorbed MB cations. They were also influenced by other parameters, such as light vs. dark conditions, the spectrum, power and duration of the light used for the irradiation; growth phases, and the pre-treatment of microorganisms. Both the photoactivity and antimicrobial properties of the colloids were improved upon pre-modification with C12. Significantly higher antimicrobial properties were observed for the colloids based on Mon with MB in the form of molecular aggregates without significant photoactivities. The MB/Mon colloids, both modified and non-modified with C12 cations, exhibited higher antimicrobial effects than pure MB solution. Besides the direct effect of photosensitization, the surface properties of the silicate particles likely played a crucial role in the interactions with microorganisms.

  12. Removal of methylene blue from aqueous solution by wood millet carbon optimization using response surface methodology.

    Science.gov (United States)

    Ghaedi, Mehrorang; Nasiri Kokhdan, Syamak

    2015-02-05

    The use of cheep, non-toxic, safe and easily available adsorbent are efficient and recommended material and alternative to the current expensive substance for pollutant removal from wastewater. The activated carbon prepared from wood waste of local tree (millet) extensively was applied for quantitative removal of methylene blue (MB), while simply. It was used to re-used after heating and washing with alkaline solution of ethanol. This new adsorbent was characterized by using BET surface area measurement, FT-IR, pH determination at zero point of charge (pHZPC) and Boehm titration method. Response surface methodology (RSM) by at least the number of experiments main and interaction of experimental conditions such as pH of solution, contact time, initial dye concentration and adsorbent dosage was optimized and set as pH 7, contact time 18 min, initial dye concentration 20 ppm and 0.2 g of adsorbent. It was found that variable such as pH and amount of adsorbent as solely or combination effects seriously affect the removal percentage. The fitting experimental data with conventional models reveal the applicability of isotherm models Langmuir model for their well presentation and description and Kinetic real rate of adsorption at most conditions efficiently can be represented pseudo-second order, and intra-particle diffusion. It novel material is good candidate for removal of huge amount of MB (20 ppm) in short time (18 min) by consumption of small amount (0.2 g).

  13. Methylene blue attenuates acute liver injury induced by paraquat in rats.

    Science.gov (United States)

    Chen, Jun-Liang; Dai, Li; Zhang, Peng; Chen, Wei; Cai, Gao-Shan; Qi, Xiao-Wei; Hu, Ming-Zhu; Du, Bin; Pang, Qing-Feng

    2015-09-01

    Paraquat (PQ) poisoning often leads to severe oxidative liver injury. Recent studies have reported that methylene blue (MB) can prevent oxidative stress-induced diseases. This study tested the hypothesis that MB treatment reduced acute liver injury induced by PQ in rats. Adult male Sprague-Dawley (SD) rats were randomly divided into four groups: (1) normal group, (2) MB group (2mg/kg i.p.), (3) PQ group (35 mg/kg i.p.) and (4) PQ+MB group (MB 2mg/kg i.p. administrated 2h after PQ). We evaluated the changes of liver histopathology, serum liver enzymatic activities, oxidative stress, heme oxygenase-1 expression, and mitochondrial permeability transition. The rats were injected with PQ produced liver injury, evidenced by histological changes and elevated serum alkaline phosphatase and alanine transaminase levels; PQ also led to oxidative stress, an increase of malondialdehyde content and mitochondrial permeability transition pore opening. Pathological damage and all of the above mentioned markers were reversed in the animals treated with MB than in those who received PQ alone. Meanwhile, MB significantly increased the contents of superoxide dismutase, adenosine triphosphate and the expression of heme oxygenase-1. In conclusion, MB had a protective effect against PQ-induced hepatic damage in rats. The mechanisms of the protection seem to be the inhibition of mitochondrial permeability transition opening and the increase of heme oxygenase-1 expression.

  14. High-speed organocatalytic polymerization of a renewable methylene butyrolactone by a phosphazene superbase

    KAUST Repository

    Schmitt, Meghan L.

    2014-01-01

    The organic phosphazene superbase, 1-tert-butyl-4,4,4-tris(dimethylamino)- 2,2-bis[tris(dimethylamino)phosphoranylid-enamino]-2λ5, 4λ5-catenadi(phosphazene) (t-Bu-P4), is found to directly initiate high-speed polymerization of the biomass-derived renewable γ-methyl-α-methylene-γ-butyrolactone (MMBL), in contrast to other polymerization systems using t-Bu-P4 which typically require addition of an organic acid or a nucleophile as a co-initiating component. This MMBL polymerization by t-Bu-P4 alone is extremely rapid; even with a low t-Bu-P4 loading of 0.1 mol% or 0.02 mol%, quantitative monomer conversion is achieved in 20 s or 1 min, respectively, affording medium to high molecular weight PMMBL bioplastics in a catalytic fashion. The combined experimental and theoretical/computational studies have yielded mechanisms of chain initiation through abstraction of a proton from a monomer by t-Bu-P 4, essentially barrier-less chain propagation through rapid conjugate addition of the enolate anion stabilized by the nano-size cation [t-Bu-P 4H]+ to the monomer, and chain termination through chain transfer to the monomer which generates a saturated termination chain end and the [t-Bu-P4H]+-stabilized anionic active species that starts a new chain. This journal is © the Partner Organisations 2014.

  15. The Coriolis Interaction between the nu(9) and nu(7) Fundamental Bands of Methylene Fluoride.

    Science.gov (United States)

    Goh; Tan; Ong; Teo

    2000-06-01

    The infrared spectrum of the nu(7) and nu(9) bands of methylene fluoride-d(2) (CD(2)F(2)) has been recorded with an unapodized resolution of 0.0024 cm(-1) in the frequency range of 940-1030 cm(-1) using the Fourier transform technique. A weak b-type Coriolis interaction term was found to couple these two vibrational states with band centers about 42 cm(-1) apart. By fitting a total of 1031 infrared transitions of both nu(7) and nu(9) with a standard deviation of 0.0011 cm(-1) using a Watson's A-reduced Hamiltonian in the I(r) representation with the inclusion of a b-type Coriolis resonance term, two sets of rovibrational constants for nu(7) = 1 and nu(9) = 1 states up to sextic order were derived. The nu(7) band is C type, while the nu(9) band is A type with band centers at 961.8958 +/- 0.0005 and 1003.7421 +/- 0.0001 cm(-1), respectively. Copyright 2000 Academic Press.

  16. Biogenic gold nanoparticles enhance methylene blue-induced phototoxic effect on Staphylococcus epidermidis

    Science.gov (United States)

    Maliszewska, Irena; Leśniewska, Agata; Olesiak-Bańska, Joanna; Matczyszyn, Katarzyna; Samoć, Marek

    2014-06-01

    There is considerable current interest in photodynamic inactivation (PDI) as potential antimicrobial therapy. This study reports successful implementation of PDI of Staphylococcus epidermidis using methylene blue (MB) in combination with biogenic gold nanoparticles (GNP). Monodispersed colloidal GNP were synthesized by reduction of Au+3 in the presence of cell-free filtrate of Trichoderma koningii and were characterized by a number of techniques including UV-Vis and fluorescence spectroscopy, transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR) to be 12 ± 3 nm spherical gold particles coated with proteins. Studies on the role of the cell-free filtrate proteins in the synthesis of the GNP indicate that the process is nonenzymatic but involves interactions of various amino acids with gold ions. A Xe lamp (550-780 nm) or a He-Ne laser (632 nm) was used as light sources to study the effect of MB alone, the GNP alone, and the MB-GNP mixture on the viability of bacterial cells. Lethal photosensitization of S. epidermidis with the MB-GNP mixture was achieved after 5 and 10 min exposure to laser or Xe lamp, respectively. It has been found that the MB-GNP mixture exhibits a significant antibacterial activity already in the absence of any light source and gives an enhanced antimicrobial response when using either a laser or a Xe lamp source for photosensitization.

  17. Removal of Congo Red and Methylene Blue from Aqueous Solutions by Vermicompost-Derived Biochars.

    Science.gov (United States)

    Yang, Gang; Wu, Lin; Xian, Qiming; Shen, Fei; Wu, Jun; Zhang, Yanzong

    2016-01-01

    Biochars, produced by pyrolyzing vermicompost at 300, 500, and 700°C were characterized and their ability to adsorb the dyes Congo red (CR) and Methylene blue (MB) in an aqueous solution was investigated. The physical and chemical properties of biochars varied significantly based on the pyrolysis temperatures. Analysis of the data revealed that the aromaticity, polarity, specific surface area, pH, and ash content of the biochars increased gradually with the increase in pyrolysis temperature, while the cation exchange capacity, and carbon, hydrogen, nitrogen and oxygen contents decreased. The adsorption kinetics of CR and MB were described by pseudo-second-order kinetic models. Both of Langmuir and Temkin model could be employed to describe the adsorption behaviors of CR and MB by these biochars. The biochars generated at higher pyrolysis temperature displayed higher CR adsorption capacities and lower MB adsorption capacities than those compared with the biochars generated at lower pyrolysis temperatures. The biochar generated at the higher pyrolytic temperature displayed the higher ability to adsorb CR owing to its promoted aromaticity, and the cation exchange is the key factor that positively affects adsorption of MB.

  18. Kinetics of basic dye (methylene blue) biosorption by giant duckweed (Spirodela polyrrhiza).

    Science.gov (United States)

    Waranusantigul, P; Pokethitiyook, P; Kruatrachue, M; Upatham, E S

    2003-01-01

    Wastewater containing pigments and/or dyes can cause serious water pollution problems in the form of reduced light penetration and photosynthesis, and the toxicity from heavy metals associated with pigments and/or dyes. Laboratory investigations, of the potential use of dried Spirodela polyrrhiza biomass as an adsorbent for the removal of the basic dye methylene blue from aqueous solution were conducted. A series of experiments were undertaken in an agitated batch adsorber to assess the effect of the system variables, i.e. sorbent dosage, pH, and contact time. The results showed that as the amount of the dried S. polyrrhiza increased, the percentage of dye sorption increased accordingly. At pH 2.0 the sorption of dye was not favorable, while the sorption at other pHs (3.0-11.0) was remarkable. There was no significant difference in the dye concentration remaining when the pH was increased from 3.0 to 11.0. The dye removal time was influenced by the initial dye concentration, and the process followed the first-order rate kinetics. The rate constants for intraparticle diffusion were 1.00 and 3.27 mg/g/min1/2 for 300 and 500 mg/l of dye, respectively.

  19. Sorption of methylene blue on treated agricultural adsorbents: equilibrium and kinetic studies

    Science.gov (United States)

    Tiwari, D. P.; Singh, S. K.; Sharma, Neetu

    2015-03-01

    Agricultural adsorbents are reported to have a remarkable performance for adsorption of dyes. In the present study, formaldehyde and sulphuric acid treated two agricultural adsorbents; potato peel and neem bark are used to adsorb methylene blue. On the whole, the acid-treated adsorbents are investigated to have high sorption efficiency compared to HCHO treated adsorbents. The percentage removal efficiency of H2SO4 treated potato peel (APP) increases considerably high from 75 to 100 % with increase in adsorbent dose, whereas the removal efficiency of H2SO4 treated neem bark (ANB) is found to be 98 % after adding the first dose only. The monolayer sorption behaviour of HCHO treated potato peel (PP) and APP is well defined by Langmuir, whereas the chemisorptions behaviour of HCHO treated neem bark (NB) and ANB is suggested by Temkin's isotherm model. The maximum adsorption capacity measured is highest in ANB followed by NB, PP and APP with the values of 1000, 90, 47.62 and 40.0 mg/g, respectively. The pseudo-second-order kinetic model fitted well with the observed data of all the four adsorbents. The results obtained reveal that NB and ANB both are good adsorbents compared to PP and APP.

  20. Mechanism of Adsorptive Removal of Methylene Blue Using Dried Biomass of Rhizopus oryzae.

    Science.gov (United States)

    Dey, Manash Deep; Shukla, Ruchi; Bordoloi, Naba K; Doley, Robin; Mukhopadhyay, Rupak

    2015-09-01

    Adsorption is an efficient way to remove synthetic dyes from industrial effluent. Here, we show mechanism of adsorptive removal of cationic dye methylene blue (MB) from its aqueous solution using dried biomass of Rhizopus oryzae as a biosorbent. The optimum pH and temperature for adsorption was found to be 7.0 and 28 °C, respectively. Scanning electron microscopy (SEM) of the biomass suggested distinct changes in surface topology post-MB adsorption, while Fourier transform infrared (FTIR) study indicated chemical interaction between the surface of the biomass and MB. Chemical modification of -OH and -C=O groups of biomass reduced the MB adsorption and corroborated with the FTIR analyses. Kinetics study revealed that the adsorption rate was fast initially and reached equilibrium at 4 h following a pseudo-second-order-kinetics. The adsorption isotherm followed Freundlich isotherm model with n value of 1.1615.The dried biomass of R. oryzae can be used as a potent biosorbent for the removal of MB.

  1. Bacteria encapsulated electrospun nanofibrous webs for remediation of methylene blue dye in water.

    Science.gov (United States)

    Sarioglu, Omer Faruk; Keskin, Nalan Oya San; Celebioglu, Asli; Tekinay, Turgay; Uyar, Tamer

    2017-04-01

    In this study, preparation and application of novel biocomposite materials that were produced by encapsulation of bacterial cells within electrospun nanofibrous webs are described. A commercial strain of Pseudomonas aeruginosa which has methylene blue (MB) dye remediation capability was selected for encapsulation, and polyvinyl alcohol (PVA) and polyethylene oxide (PEO) were selected as the polymer matrices for the electrospinning of bacteria encapsulated nanofibrous webs. Encapsulation of bacterial cells was monitored by scanning electron microscopy (SEM) and fluorescence microscopy, and the viability of encapsulated bacteria was checked by live/dead staining and viable cell counting assay. Both bacteria/PVA and bacteria/PEO webs have shown a great potential for remediation of MB, yet bacteria/PEO web has shown higher removal performances than bacteria/PVA web, which was probably due to the differences in the initial viable bacterial cells for those two samples. The bacteria encapsulated electrospun nanofibrous webs were stored at 4°C for three months and they were found as potentially storable for keeping encapsulated bacterial cells alive. Overall, the results suggest that electrospun nanofibrous webs are suitable platforms for preservation of living bacterial cells and they can be used directly as a starting inoculum for bioremediation of water systems.

  2. Photocatalytic Degradation of Methylene Blue Using TiO2-Natural Zeolite as A Photocatalyst

    Directory of Open Access Journals (Sweden)

    Sri Wardhani

    2016-01-01

    Full Text Available TiO2 - zeolite photocatalyst has been prepared by impregnation of TiO2 onto acid -activated natural zeolite. The XRD data confirmed that natural zeolite used in this work is predominated with mordenite and clinoplitolite types, whereas anatase type can be attributed to TiO2. The highest performance of TiO2 – zeolite, which is indicated by surface area of 13.304 m2/g and band gap energy of 3.15 eV, is obtained when 10 mmol of TiO2 is impregnated onto the zeolite. The ability of this photocatalyst is evaluated by examining degradation of methylene blue (MB in the presence of UV source. The effects of MB concentration, pH and UV irradiation time on the degradation are studied in a batch reactor. It is interesting since the addition of H2O2 can improve the degradation effeciency of MB. The optimum result is achieved at pH 11, duration of UV irradiation of 50 min, showing degradation amount of 98.25 %. Surprisingly, the chemical oxygen demand (COD in the degraded MB aqueous solution can be reduced about 77.9%, exhibiting the improvement of water quality. No loss of the activity of the degradation efficiency after reusability of this TiO2 - zeolite photocatalyst for at least 4 times.

  3. In vitro lethal photosensitization of S. mutans using methylene blue and toluidine blue O as photosensitizers.

    Science.gov (United States)

    Araújo, Patrícia V; Teixeira, Karina I R; Lanza, Lincoln D; Cortes, Maria E; Poletto, Luiz T A

    2009-01-01

    The purpose of this in vitro study was to evaluate the antimicrobial effect of photodynamic therapy on Streptococcus mutans (A TCC 25175) suspensions, using a red laser for one minute in combination with toluidine blue O (TBO) or methylene blue (MB). Both photosensitizers were used in three concentrations (25, 10 and 5 mg/L). The activity ofphotosensitizers and laser irradiation were tested separately on the bacteria, as well as the irradiation of this light source in the presence of the TBO or MB. These groups were compared to a control group, in which the microorganism did not receive any treatment. The activity of both TBO and MB or laser irradiation, alone, were not able to reduce the number of S. mutans. In the groups of lethal photosensitization, a bacterial reduction of 70% for TBO and 73% for MB was observed when these photosensitizers were used at 25 mg/L and a reduction of 48% was observed for MB at 5mg/L. In other concentrations there were no significant differences in comparison to the control group. Both the TBO and the MB at 25 mg/L associated with a red laser had an excellent potential for use in PDT in lethal sensitization of S. mutans.

  4. Adsorption of Methylene Blue from Aqueous Solutions by Polyvinyl Alcohol/Graphene Oxide Composites.

    Science.gov (United States)

    Yang, Xiaoxia; Li, Yanhui; Du, Qiuju; Wang, Xiaohui; Hu, Song; Chen, Long; Wang, Zonghua; Xia, Yanzhi; Xia, Linhua

    2016-02-01

    As a new member of the carbon family, graphene oxide (GO) has shown excellent adsorption ability to micro-pollutants in aqueous solutions. However, its tiny size makes it difficult to be removed from aqueous solutions using the conventional separation methods, which limits its practical application in the environmental protection. In this study, polyvinyl alcohol (PVA) was used as carrier immobilizing GO, and novel PVA/GO composites were prepared. The morphology and physicochemical properties of the composites were characterized by SEM, FTIR and TGA analysis. The adsorption properties of methylene blue (MB) onto the composites were studied through investigating the experimental parameters such as solution pH, adsorbent dosage, contact time and temperature. The isotherm data were analyzed using the Langmuir, Freundlich and Dubinin-Radushkevich models. The calculated maximum adsorption capacity reached 476.2 mg/g at 50% GO content. The pseudo-first-order kinetic, pseudo-second-order kinetic and intra-particle diffusion models were used to explore the adsorption kinetics. The results showed that the dynamic data were fitted to the pseudo-second-order kinetic model.

  5. Prokineticin 2 facilitates mechanical allodynia induced by α,β-methylene ATP in rats.

    Science.gov (United States)

    Ren, Cuixia; Qiu, Chun-Yu; Gan, Xiong; Liu, Ting-Ting; Qu, Zu-Wei; Rao, Zhiguo; Hu, Wang-Ping

    2015-11-15

    Prokineticin 2 (PK2), a new chemokine, causes mechanical hypersensitivity in the rat hind paw, but little is known about the molecular mechanism. Here, we have found that ionotropic P2X receptor is essential to mechanical allodynia induced by PK2. First, intraplantar injection of high dose (3 or 10 pmol) of PK2 significantly increased paw withdrawal response frequency (%) to innocuous mechanical stimuli (mechanical allodynia). And the mechanical allodynia induced by PK2 was prevented by co-administration of TNP-ATP, a selective P2X receptor antagonist. Second, although low dose (0.3 or 1 pmol) of PK2 itself did not produce an allodynic response, it significantly facilitated the mechanical allodynia evoked by intraplantar injection of α,β-methylene ATP (α,β-meATP). Third, PK2 concentration-dependently potentiated α,β-meATP-activated currents in rat dorsal root ganglion (DRG) neurons. Finally, PK2 receptors and intracellular signal transduction were involved in PK2 potentiation of α,β-meATP-induced mechanical allodynia and α,β-meATP-activated currents, since the potentiation were blocked by PK2 receptor antagonist PKRA and selective PKC inhibitor GF 109203X. These results suggested that PK2 facilitated mechanical allodynia induced by α,β-meATP through a mechanism involved in sensitization of cutaneous P2X receptors expressed by nociceptive nerve endings.

  6. Papain gel containing methylene blue for simultaneous caries removal and antimicrobial photoinactivation against Streptococcus mutans biofilms

    Science.gov (United States)

    Silva Jr., Zenildo Santos; Huang, Ying-Ying; de Freitas, Lucas Freitas; França, Cristiane Miranda; Botta, Sergio Brossi; Ana, Patrícia Aparecida; Mesquita-Ferrari, Raquel Agnelli; Santos Fernandes, Kristianne Porta; Deana, Alessandro; Lima Leal, Cintia Raquel; Prates, Renato Araujo; Hamblin, Michael R.; Bussadori, Sandra Kalil

    2016-01-01

    This study intended to evaluate the effects of a papain-gel with a red-light absorbing pigment (methylene blue – MB) to mediate photodynamic therapy (PDT) against Streptococcus mutans biofilms. The PapaMBlue was compared with free MB to generate reactive oxygen species using fluorescence probes (SOSG and HPF). PDT (660-nm light) was carried out against S. mutans biofilms grown on either plastic dishes or on collagen membrane and assayed by CFU, live-dead staining using confocal microscopy, transmission electron microscopy and H&E staining for collagen films. Cytotoxicity and subcellular localization was studied in human fibroblasts. Sponges of bioabsorbable type I collagen membrane were exposed to papain based gel, irradiated with laser and analyzed about their integrity by ATR-FTIR. The PapaMBlue produced higher amounts of singlet oxygen and hydroxyl radicals than free MB, possibly due to better disaggregation of the dye in solution. The PapaMBlue antimicrobial effects on biofilms proved to be capable of reducing the S. mutans. Both MTT and PrestoBlue assays showed higher cell viability and metabolism scores in fibroblasts treated with PapaMBlue and MB, possibly due to stimulation of mitochondrial activity and that collagen triple helix is unaffected. The PapaMBlue is equally effective as MB in destroying S. mutans biofilms growing on plastic or collagen without affecting fibroblasts. PMID:27641507

  7. Treatment and toxicity evaluation of methylene blue using electrochemical oxidation, fly ash adsorption and combined electrochemical oxidation-fly ash adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Kai-sung Wang; Ming-Chi Wei; Tzu-Huan Peng; Heng-Ching Li; Shu-Ju Chao; Tzu-Fang Hsu; Hong-Shen Lee; Shih-Hsien Chang [Chung-Shan Medical University, Taichung (Taiwan)

    2010-08-15

    Treatment of a basic dye, methylene blue, by electrochemical oxidation, fly ash adsorption, and combined electrochemical oxidation-fly ash adsorption was compared. Methylene blue at 100 mg L{sup -1} was used in this study. The toxicity was also monitored by the Vibrio fischeri light inhibition test. When electrochemical oxidation was used, 99% color and 84% COD were removed from the methylene blue solution in 20 min at a current density of 428 A m{sup -2}, NaCl of 1000 mg L{sup -1}, and pH{sub 0} of 7. However, the decolorized solution showed high toxicity (100% light inhibition). For fly ash adsorption, a high dose of fly ash (>20,000 mg L{sup -1}) was needed to remove methylene blue, and the Freundlich isotherm described the adsorption behavior well. In the combined electrochemical oxidation-fly ash adsorption treatment, the addition of 4000 mg L{sup -1} fly ash effectively reduced intermediate toxicity and decreased the COD of the electrochemical oxidation-treated methylene blue solution. The results indicated that the combined process effectively removed color, COD, and intermediate toxicity of the methylene blue solution.

  8. Computed tomography guided percutaneous injection of a mixture of lipiodol and methylene blue in rabbit lungs: evaluation of localization ability for video-assisted thoracoscopic surgery.

    Science.gov (United States)

    Jin, Kwang Nam; Lee, Kyung Won; Kim, Tae Jung; Song, Yong Sub; Kim, Dong Il

    2014-01-01

    Preoperative localization is necessary prior to video assisted thoracoscopic surgery for the detection of small or deeply located lung nodules. We compared the localization ability of a mixture of lipiodol and methylene blue (MLM) (0.6 mL, 1:5) to methylene blue (0.5 mL) in rabbit lungs. CT-guided percutaneous injections were performed in 21 subjects with MLM and methylene blue. We measured the extent of staining on freshly excised lung and evaluated the subjective localization ability with 4 point scales at 6 and 24 hr after injections. For MLM, radio-opacity was evaluated on the fluoroscopy. We considered score 2 (acceptable) or 3 (excellent) as appropriate for localization. The staining extent of MLM was significantly smaller than methylene blue (0.6 vs 1.0 cm, Pmethylene blue (2.8 vs 2.2, P=0.010). Excellent staining was achieved in 17 subjects (81%) with MLM and 8 (38%) with methylene blue (P=0.011). An acceptable or excellent radio-opacity of MLM was found in 13 subjects (62%). An appropriate localization rate of MLM was 100% with the use of the directly visible ability and radio-opacity of MLM. MLM provides a superior pulmonary localization ability over methylene blue.

  9. Synthesis and characterization of TiO2 pillared montmorillonites: application for methylene blue degradation.

    Science.gov (United States)

    Chen, Daimei; Du, Gaoxiang; Zhu, Qian; Zhou, Fengsan

    2013-11-01

    TiO2 pillared clay composites were prepared by modifying of montmorillonite (Mt) with cetyl-trimethyammoniumbromide (CTAB) and then using an acidic solution of hydrolyzed Ti alkoxide to intercalate into the interlayer space of the organic modified Mt. The as-prepared materials were characterized by XRD, FTIR, TEM, SEM TG-DTA, specific surface area and porosity measurements. The composites had a porous delaminated structure with pillared fragments and well dispersed TiO2 nanoparticles. Introduction of CTAB into the synthetic system accelerated the hydrolysis and condensation of the Ti source, which promoted TiO2 formation. In addition, the CTAB also significantly increased the porosity and surface area of the composites. A number of anatase particles, with crystal sizes of 5-10 nm, were homogenously distributed on the surface of the Mt as the result of the templating role of CTAB. The resultant TiO2 pillared Mt exhibited good thermal stability as indicated by its surface area after calcination at 800°C. No phase transformations from anatase to rutile were observed even under calcination at 900°C. The grain size of the anatase in prepared sample increased from 2.67 nm to 13.42 nm as the calcination temperature increased from 300°C to 900°C. The photocatalytic performance of these new porous materials was evaluated by using methylene blue degradation. The composite exhibited better photocatalytic property than P 25. The maximum removal efficiency of this composite was up to 99% within 60 min.

  10. Highly efficient photocatalytic degradation of methylene blue by PoPD/TiO2 nanocomposite.

    Science.gov (United States)

    Yang, Chuanxi; Zhang, Ming; Dong, Wenping; Cui, Guanwei; Ren, Zongming; Wang, Weiliang

    2017-01-01

    The poly-o-phenylenediamine (PoPD)/TiO2 nanocomposite was successfully synthesized via 'in situ' oxidative polymerization method. The modified photocatalysts were characterized by BET, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrarad spectra (FT-IR), thermogravimrtic analysis (TGA), X-ray photoelectron spectroscopy (XPS), Ultraviolet-visible diffuse reflectance spectrum (UV-Vis DRS) and Photocurrent Test. The results showed that the PoPD exists on the surface of TiO2, the presence of PoPD does not impact on the lattice structure and grain size of TiO2, and the presence of PoPD enhances the visible response and photoelectric property. The photocatalytic degradation of methylene blue (MB) was chosen as a model reaction to evaluate the photocatalytic activities of TiO2 and PoPD/TiO2. The optimal preparation condition was the molar ratio of oPD to TiO2 = 3:1, HCl concentration = 1.2 mol/L, the molar ratio of APS to oPD = 1:1. The apparent first-order rate constant kapp of PoPD/TiO2 nanocomposite was 0.0098 min-1, which is 6 times higher than TiO2 (0.0016 min-1). Meanwhile, the PoPD/TiO2 nanocomposites showed excellent photocatalytic stability, and the photocatalytic stability was depended on the stability of structure. At last, the photocatalytic mechanism of POPD/TiO2 nanocomposites was also proposed based on the synergetic effect between TiO2 and PoPD.

  11. Electrochemical regeneration of a reduced graphene oxide/magnetite composite adsorbent loaded with methylene blue.

    Science.gov (United States)

    Sharif, Farbod; Gagnon, Luke R; Mulmi, Suresh; Roberts, Edward P L

    2017-05-01

    In this work, two different reduced graphene oxide/iron oxide (rGO-IO) nanocomposites with different iron oxide loadings were fabricated using a one-step solvothermal method. The structure, properties and applications of the synthesized nanocomposites were evaluated with Raman spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, electron microscopy, and energy-dispersive X-ray spectroscopy. The iron oxide is in the form of magnetite (Fe3O4), so that the resultant adsorbent can readily be separated from the treated water using a magnetic field. The ability of the nanocomposites to remove methylene blue (MB) from water by adsorption was investigated. The highest adsorptive capacity observed was 39 mg g(-1), for the composite containing 60 wt% iron oxide. The adsorptive capacity of the rGO-IO decreased to 26 mg g(-1) when the mass fraction of iron oxide was increased to 75 wt%. Electrochemical regeneration of MB loaded rGO-IO was also investigated. The electrochemical regeneration was found to be rapid and with low electrical energy consumption relative to conventional adsorbents, due to the high electrical conductivity and nonporous surface of the rGO. A regeneration efficiency of 100% was obtained after 30 min of electrochemical treatment using a 2 mm thick bed of rGO-IO loaded with 39 mg g(-1) MB, using a current density of 10 mA cm(-2). Multiple adsorption-electrochemical regeneration cycles demonstrated that the surface of the rGO was modified leading to increase in the adsorptive capacity to around 80 mg g(-1) after the second regeneration cycle. The morphology of the rGO was observed to change significantly after electrochemical regeneration, suggesting that the rGO based adsorbent materials could only be used for a few cycles.

  12. Effect of methylene methanedisulfonate as an additive on the cycling performance of spinel lithium titanate electrode

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Renheng; Li, Xinhai; Zhang, Bao, E-mail: 123501032@csu.edu.cn; Wang, Zhixing; Guo, Huajun

    2015-11-05

    In order to overcome the poor cyclability of lithium-ion batteries with spinel lithium titanate (Li{sub 4}Ti{sub 5}O{sub 12}), methylene methanedisulfonate (MMDS) is evaluated as electrolyte additive. The linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) indicate that MMDS participates in the formation process of the solid electrolyte interface (SEI) film above 1 V, which is due to the interfacial reaction between the electrode and electrolyte: Li{sub 4}Ti{sub 5}O{sub 12} anodes are previously considered free from SEI films when cycled between 1 and 3 V. The stable SEI film around Li{sub 4}Ti{sub 5}O{sub 12} is seen most effective as a barrier layer in suppressing the interfacial reaction and resulting gassing from the Li{sub 4}Ti{sub 5}O{sub 12} surface. In addition, the results of electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and transmission electron microscopy (TEM) demonstrate that a thin and good conductive film can be formed on the Li{sub 4}Ti{sub 5}O{sub 12} surface ascribed to MMDS additive, which resulting the improvement of conductivity and a good ability of Li{sup +} migration. - Highlights: • MMDS used as additive to improve cycling performance of the Li{sub 4}Ti{sub 5}O{sub 12}/Li cells. • A SEI film can be formed using MMDS in the electrolyte above 1 V. • Sulfur-containing species is the main component of the SEI formed by MMDS.

  13. Comparative evaluation of methylene blue and demeclocycline for enhancing optical contrast of brain neoplasms

    Science.gov (United States)

    Wirth, Dennis J.

    Brain tumors cause significant morbidity and mortality even when benign. Completeness of resection of brain tumors has been associated with better quality of life. However, that is often difficult to accomplish. The goal of this study was to evaluate the feasibility of using contrast enhanced multimodal confocal imaging for intraoperative detection of brain neoplasms. Different types of benign and malignant, primary and metastatic brain tumors, stained with Methylene Blue (MB) as a contrast agent, were imaged. MB is a traditional histopathologic stain that absorbs light in the red spectral range and fluoresces in the near infrared. It is FDA-approved for in vivo staining of human skin and breast tissue. Optical images showed good correlation with histopathology, demonstrating the potential of contrast enhanced multimodal confocal imaging for intraoperative detection of brain neoplasms ex vivo. However, the safety of MB for staining human brain in vivo is questionable. Demeclocycline (DMN), an antibiotic of the tetracycline family, has shown to be effective in differentiating normal from cancerous tissue in various organs. DMN is a fluorophore, which absorbs light in the violet spectral range and has a broad emission band covering green and yellow wavelengths. It is commonly used to treat infection and inflammatory disorders, and could provide a safer alternative to MB. To test this hypothesis, fresh excess human brain tissues were bisected and stained with aqueous solutions of either MB or DMN and then imaged. Reflectance and fluorescence images acquired from tissues stained with the two dyes were compared, and correlated with processed H&E histopathology. Comparison showed similar staining patterns and contrast of diagnostic features in glioblastomas, stained using either MB or DMN. The results show potential of both MB and DMN for the intraoperative detection of microscopic nests of brain neoplasms. Further studies will establish safety and efficacy of these

  14. Development of therapeutic Au-methylene blue nanoparticles for targeted photodynamic therapy of cervical cancer cells.

    Science.gov (United States)

    Yu, Jiashing; Hsu, Che-Hao; Huang, Chih-Chia; Chang, Po-Yang

    2015-01-14

    Photodynamic therapy (PDT) involves the cellular uptake of a photosensitizer (PS) combined with oxygen molecules and light at a specific wavelength to be able to trigger cancer cell death via the apoptosis pathway, which is less harmful and has less inflammatory side effect than necrosis. However, the traditional PDT treatment has two main deficiencies: the dark toxicity of the PS and the poor selectivity of the cellular uptake of PS between the target cells and normal tissues. In this work, methylene blue (MB), a known effective PS, combined with Au nanoparticles (NPs) was prepared using an intermolecular interaction between a polystyrene-alt-maleic acid (PSMA) layer on the Au NPs and MB. The Au@polymer/MB NPs produced a high quantum yield of singlet oxygen molecules, over 50% as much as that of free MB, when they were excited by a dark red light source at 660 nm, but without significant dark toxicity. Furthermore, transferrin (Tf) was conjugated on the Au@polymer/MB NPs via an EDC/NHS reaction to enhance the selectivity to HeLa cells compared to 3T3 fibroblasts. With a hand-held single laser treatment (32 mW/cm) for 4 min, the new Au@polymer/MB-Tf NPs showed a 2-fold enhancement of PDT efficiency toward HeLa cells over the use of free MB at 4 times dosage. Cellular staining examinations showed that the HeLa cells reacted with Au@polymer/MB-Tf NPs and the 660 nm light excitation triggered PDT, which caused the cells to undergo apoptosis ("programmed" cell death). We propose that applying this therapeutic Au@polymer/MB-Tf nanoagent is facile and safe for delivery and cancer cell targeting to simultaneously minimize side effects and accomplish a significant enhancement in photodynamic therapeutic efficiency toward next-generation nanomedicine development.

  15. [Study on treatment of methylene blue wastewater by fly ash adsorption-Fenton and thermal regeneration].

    Science.gov (United States)

    Bai, Yu-Jie; Zhang, Ai-Li; Zhou, Ji-Ti

    2012-07-01

    The physicochemical properties of water-washed fly ash (FA) and acid modified fly ash (M-FA) were investigated. The adsorption of methylene blue by FA and M-FA were studied by batch experiments. Two methods, Fenton-drive oxidation regeneration and thermal regeneration, were used for regeneration of the used FA and M-FA. The result showed that the rate of adsorption process followed the second order kinetics and the adsorption followed Langmuir isotherms. The adsorption equilibrium time was 30 min, and the equilibrium adsorption capacity of FA and M-FA were 4.22 mg x g(-1) and 5.98 mg x g(-1) respectively. The adsorption capability of M-FA was higher than that of FA. In the range of pH 2-12, the adsorption capacity of M-FA increased with the increase of pH, whereas the adsorption capacity of FA decreased slowly until the pH 8 and then increased. Electrostatic adsorption was the major factor on the adsorption capacity. Around 61% and 55% percentage regeneration (PR) were obtained for FA and M-FA respectively when 78.4 mmol x L(-1) H2O2 and 0.72 mmol x L(-1) Fe2+ were used. When the condition of thermal regeneration was 400 degrees C and 2 h, a positive correlation can be found between the PRs of FA and regeneration times, the PRs were 102%, 104% and 107% in three cycles of adsorption-thermal regeneration process. However a negative correlation can be found between the PRs of M-FA and regeneration times, the PRs were 82%, 75% and 74% in three cycles of adsorption-thermal regeneration process. The PR of FA was higher than that of M-FA, and thermal regeneration was superior to Fenton-drive regeneration.

  16. Osteodystrophy in liver cirrhosis. Its demonstration by 99m Tc methylene diphosphonate bone scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Sezai, Shu-ichi; Ishizawa, Suguru; Yoshino, Katsumasa

    1987-10-01

    In order to investigate the osteodystrophy in liver cirrhosis, 21 liver cirrhotic patients having no malignancy and normal renal function were examined by 99m Tc Methylene Diphosphonate (MDP) bone scintigraphy. The cirrhotic subjects consisted of 14 males and 7 females. Their age was 31 - 80, average 55.7 years. The causes of their cirrhotic damage were 1 primary biliary cirrhosis, 9 alcoholic, 2 HB viral and 9 cryptogenic. The contents of their illness showed 9 cases in A, 4 in B and 8 in C of Child's classification. Abnormal hot spot(s) on bone in the cirrhotics could be observed very frequently in 99m Tc MDP bone scintigraphy (47.6 %; 10/21 cases). Those spots were seen more frequently in female and advanced stage of cirrhosis. The number of spot(s) increased also in advanced liver cirrhosis. Serum Ca, P and PTH were in normal range. All of three vitamin D/sub 3/ fractions decreased and especially 1,25 (OH)/sub 2/D/sub 3/ was depressed more in scinti-positive cases. Metacarpal bone X-p with an alumimum step wedge as a reference was analyzed by a microdensitometry (MD) method (Inoue T et al) and the pattern of osteopathy (i.e. porosis, malacia and poromalacia) was examined according to Sumi Y et al. MD method was not known yet if there was any definite correlation with bone scintigraphy and the osteopathic pattern belonged to border categories. In conclusion, more attension on hepatic osteodystrophy will be significantly necessary due to the fact that it has been found very frequently in liver cirrhosis. 99m Tc MDP bone scintigraphy is a good means for detection of the hepatic osteodystrophy.

  17. Methylene Blue Removal by Biochars from Food Industry By-Products

    Science.gov (United States)

    Orfanos, Alexis; Manariotis, Ioannis D.; Karapanagioti, Hrissi K.

    2016-04-01

    Biomass produced by food industries is mainly used as feedstock or in composting. In recent years, considerable research effort has been focused on the production of biochar under oxygen-limited conditions from carbon-rich biomass, such as food industry by-products, as mitigation measure for global warming once it is used as a soil amendment. The present study presents the findings of an experimental work, which investigated the use of different biochars for the removal of methylene blue (MB) from aqueous solutions. Biochars were produced from malt spent rootlets (MSR) from brewering and espresso coffee residue from coffee shops. MSR was pyrolyzed at temperatures of 300, 400, 500, 750, 850, and 900oC and the coffee residue was pyrolyzed at 850oC. The charring process was performed under limited-oxygen conditions using specialized containers. The surface area and the porosity of the materials were determined. Batch experiments were conducted in order to evaluate the sorption capacity of the above materials, and samples were agitated for 24 h at 25oC, at an optimum pH of about 7. Kinetic analysis was conducted over a period of 24 h, and isotherm studies were also constructed. The surface area of biochar produced from MSR and the MB removal were considerably increased at pyrolysis temperatures higher than 500oC. At 850oC, the maximum surface area value (300 m2 g-1) was observed, and the MB sorption capacity was 99 mg g-1. Based on the kinetic experimental data, sorption capacities at 120 min were over 58% of their equilibrium values for the biochars used. The maximum MB sorption capacity, based on the isotherm data, was 130 mg g-1, for the two biochars employed.

  18. Reduction of methylene green by EDTA: a relation between dielectric constant of medium and activated state.

    Science.gov (United States)

    Qamar, Noshab; Azmat, Rafia; Naz, Raheela

    2013-01-01

    Kinetics of an alkaline reduction of the methylene green with ethylenediaminetetraaceticacid (EDTA) as a role of dielectric constant of the medium with anecdotal ionic strength in a diverse solvent system (aqueous mixtures of methanol) (10-30%) was studied by measuring the specific rate constant of the reaction spectrophotometrically at λ (max) = 660nm. An effort has been made to give an elucidation of vital role of dielectric constant of the medium captivating into reflection of single sphere and double sphere complex in reaction assortment. This investigation leads to disclose that single sphere complex of the dye and reductant was found to be the most suitable complex existed in a varied organic solvent. The deviation of the theoretical values from experimental results for single sphere and double sphere complex model in the presence of an alkali and nitrate ions were justified through HPLC analysis. HPLC analysis recommended that a considerable amount of the dye degrades in the existence of nitrate ion and alkali and additional peaks which may be of by-product were obtained. This leads to confirm the non identical values of single sphere and double sphere model in the occurrence of nitrate and an alkali. Rate of deletion of color showed a linear liaison with respect to water content below 30% and temperature between 20-40(o)C whereas an increase in the concentration of organic solvent showed the inhibition of dye decoloration at given optimum condition. Therefore study was restricted up to 30% of methanol binary mixtures. A mechanism of reduction of dye has been proposed based on verdict.

  19. Methylene blue toxicity in zebrafish cell line is dependent on light exposure.

    Science.gov (United States)

    Costa, Simone Rutz da; Monteiro, Mauricio da Costa; da Silva Júnior, Flavio Manoel Rodrigues; Sandrini, Juliana Zomer

    2016-08-01

    Methylene blue (MB) has been widely applied in the clinical area and is currently being used in aquaculture as biocide. Some recent studies have emphasized the importance of understanding the action mechanism and the MB cellular targets. In this sense, zebrafish is considered a relevant model to study the intrinsic pathway of apoptosis as well as the cellular responses involving DNA damage and repair. So, the aim of the present study was to compare MB action mechanisms in a zebrafish cell line, both in the absence (MB alone; dark toxicity) and in the presence of photosynthetically active radiation (MB+PAR; phototoxicity). There was a significant increase of the levels of reactive oxygen and nitrogen species 3 h after MB treatment, whereas this increase was only observed 12 h after treatment with MB+PAR. All treatments with MB resulted in an increase in DNA damage after 3 and 6 h. However, cell death by apoptosis was observed from 6 h after treatment with MB+PAR and 12 h after treatment with MB alone. The expression of genes related to apoptosis was altered after MB and MB+PAR treatment. Therefore, this zebrafish cell line is sensitive to the photodynamic action of MB; MB is able to generate DNA damage and induce apoptosis in this cell line both alone and in the presence of PAR. However, the pathways leading to apoptosis in this model appear to be dependent on the type of MB exposure (in the presence or absence of PAR).

  20. Mechanism of Methylene Blue adsorption on hybrid laponite-multi-walled carbon nanotube particles.

    Science.gov (United States)

    Manilo, Maryna; Lebovka, Nikolai; Barany, Sandor

    2016-04-01

    The kinetics of adsorption and parameters of equilibrium adsorption of Methylene Blue (MB) on hybrid laponite-multi-walled carbon nanotube (NT) particles in aqueous suspensions were determined. The laponite platelets were used in order to facilitate disaggregation of NTs in aqueous suspensions and enhance the adsorption capacity of hybrid particles for MB. Experiments were performed at room temperature (298 K), and the laponite/NT ratio (Xl) was varied in the range of 0-0.5. For elucidation of the mechanism of MB adsorption on hybrid particles, the electrical conductivity of the system as well as the electrokinetic potential of laponite-NT hybrid particles were measured. Three different stages in the kinetics of adsorption of MB on the surface of NTs or hybrid laponite-NT particles were discovered to be a fast initial stage I (adsorption time t=0-10 min), a slower intermediate stage II (up to t=120 min) and a long-lasting final stage III (up to t=24hr). The presence of these stages was explained accounting for different types of interactions between MB and adsorbent particles, as well as for the changes in the structure of aggregates of NT particles and the long-range processes of restructuring of laponite platelets on the surface of NTs. The analysis of experimental data on specific surface area versus the value of Xl evidenced in favor of the model with linear contacts between rigid laponite platelets and NTs. It was also concluded that electrostatic interactions control the first stage of adsorption at low MB concentrations.

  1. Clay mineral particles as effficient carriers of methylene blue used for antimicrobial treatment.

    Science.gov (United States)

    Bujdák, Juraj; Jureceková, Jana; Bujdákova, Helena; Lang, Kamil; Sersen, Frantisek

    2009-08-15

    There is a strong demand to identify new strategies for disinfection and treatment of human, animal, and plant pathogens. The presented work shows the potential of clay minerals to contribute to the development of novel disinfection materials. Enhanced antimicrobial effect of a photoactive organic dye, methylene blue (MB), in the colloids of clay mineral was observed. Singlet oxygen (1O2) formed upon visible light irradiation was detected directly using luminescence measurements atthe near-infrared region and by spin-trapping method. While MB adsorbed on clay colloid particles lost the ability to produce 1O2 due to molecular aggregation, surprisingly, the antimicrobial activity was significantly enhanced. Under visible light irradiation, MB/clay minerals dispersions prevented the sporulation of A. niger and Penicillium sp. and inhibited the growth of C. albicans by an additional 6-15% when compared with MB solution. In the experiments with E. coli, the efficiency of MB was increased by the reduction of surviving cells by 27 and 33%. S. aureus proved to be the most susceptible to MB/clay dispersions. Only less than 20% cells survived with respect to the control experiment at the low MB concentration (1.1 x 10(-6) mol dm(-3)). The contradiction between the significant antimicrobial properties of MB in clay colloidal systems and low 1O2 formation can be explained in terms of the photosensitization mechanism. The role of clay particles is most likely to promote the contact between microorganism cells and photoactive MB. Although the dye directly bound to the clay surface exhibits significantly reduced photoactivity, the presence of clay mediates the delivery of dye molecules on the surface or inside cells. The results indicate new perspectives of potential implementations of clay minerals as parts of complex disinfection materials for industrial applications or in understanding similar processes in nature.

  2. Functional Polymeric Systems as Delivery Vehicles for Methylene Blue in Photodynamic Therapy.

    Science.gov (United States)

    Junqueira, Mariana V; Borghi-Pangoni, Fernanda B; Ferreira, Sabrina B S; Rabello, Bruno R; Hioka, Noboru; Bruschi, Marcos L

    2016-01-12

    Antibiotic-resistant microorganisms have become a global concern, and the search for alternative therapies is very important. Photodynamic therapy (PDT) consists of the use of a nontoxic photosensitizer (PS), light, and oxygen. This combination produces reactive oxygen species and singlet oxygen, which can alter cellular structures. Methylene blue (MB) is a substance from the phenothiazine class often used as a PS. In this work, to facilitate the PS contact within the wounds, we have used Design of Experiments 2(3) plus central point to develop functional polymeric systems. The formulations were composed by poloxamer 407 [15.0, 17.5, or 20.0% (w/w)], Carbopol 934P [0.15, 0.20, or 0.25% (w/w)], and MB [0.25, 0.50, or 0.75% (w/w)]. The sol-gel transition temperature, flow rheometry, in vitro MB release, and ex vivo study of MB cutaneous permeation and retention were investigated. Moreover, the evaluation of photodynamic activity was also analyzed by in vitro degradation of tryptophan by singlet oxygen and using Artemia salina. The determination of the gelation temperature displayed values within the range of 25-37 °C, and the systems with better characteristics were subjected to rheological analysis and in vitro release profiling. The 20/0.15/0.25 formulation showed the best release profile (42.57% at 24 h). This system displayed no significant skin permeation (0.38% at 24 h), and the photooxidation of tryptophan test showed the production of reactive species of oxygen. The toxicity test using A. salina revealed that the MB associated with the light increased the mortality rate by 61.29%. Therefore, investigating the PDT efficacy of the functional polymeric system containing MB will be necessary in the future.

  3. Adsorptive removal of methylene blue by rhamnolipid-functionalized graphene oxide from wastewater.

    Science.gov (United States)

    Wu, Zhibin; Zhong, Hua; Yuan, Xingzhong; Wang, Hou; Wang, Lele; Chen, Xiaohong; Zeng, Guangming; Wu, Yan

    2014-12-15

    In this article, a rhamnolipid-functionalized graphene oxide (RL-GO) hybrid was prepared by one-step ultrasonication and adsorptive removal of methylene blue (MB) from both artificial and real wastewater by the RL-GO was investigated. The Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Fourier transform infrared spectrum (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) area and Zeta potential analysis were used to characterize the adsorbent. The results showed that RL-GO had abundant functional groups and a mesopores feature. MB adsorption by the RL-GO increased with increase in adsorbent dose, pH, temperature and initial MB concentration, while it was insensitive to ionic strength variation. The adsorption kinetics fitted well to the pseudo-second-order model with correlation coefficients greater than 0.999. The Intra-particle diffusion and Boyd's film-diffusion models showed that the rate-controlled step was dominated by film-diffusion in the beginning and then followed by intra-particle diffusion. The adsorption isotherm was fitted by adsorption models with the suitability in order of BET > Freundlich > Langmuir > Temkin, based on comparison between correlation coefficients. Thermodynamic analysis of equilibriums suggested that the adsorption MB on RL-GO was spontaneous and endothermic. The adsorption mechanism was also proposed to be electrostatic attraction, π-π interaction and hydrogen bond. In addition, the real wastewater experiment, the regeneration study and the comparative cost analysis showed that the RL-GO composites could be a cost-effective and promising sorbent for MB wastewater treatment owing to its high efficiency and excellent reusability.

  4. Methylene blue injection into the rectal artery as a simple method to improve lymph node harvest in rectal cancer.

    Science.gov (United States)

    Märkl, Bruno; Kerwel, Therese G; Wagner, Theodor; Anthuber, Matthias; Arnholdt, Hans M

    2007-07-01

    Adequate lymph node assessment in colorectal cancer is crucial for prognosis estimation and further therapy stratification. However, there is still an ongoing debate on required minimum lymph node numbers and the necessity of advanced techniques such as immunohistochemistry or PCR. It has been proven in several studies that lymph node harvest is often inadequate under routine analysis. Lymph nodes smaller than 5 mm are especially concerning as they can carry the majority of metastases. These small, but affected lymph nodes may escape detection in routine analysis. Therefore, fat-clearing protocols and sentinel techniques have been developed to improve accuracy of lymph node staging. We describe a novel and simple method of ex vivo methylene blue injection into the superior rectal artery of rectal cancer specimens, which highlights lymph nodes and makes them easy to detect during manual dissection. Initially, this method was developed for proving accuracy of total mesorectal excision. We performed a retrospective study comparing lymph node recovery of 12 methylene blue stained and an equal number of unstained cases. Lymph node recovery differed significantly with average lymph node numbers of 27+/-7 and 14+/-4 (Pmethylene blue and the unstained group, respectively. The largest difference was found in size groups between 1 and 4 mm causing a shift in size distribution toward smaller nodes. Metastases were confirmed in 21 and 19 lymph nodes occurring in five and four cases, respectively. Hence, we conclude that methylene blue injection technique improves accuracy of lymph node staging by heightening the lymph node harvest in rectal resections. In our experience, it is a very simple time and cost effective method that can be easily established under routine circumstances.

  5. A prospective study on sentinel lymph node biopsy in early oral cancers using methylene blue dye alone.

    Science.gov (United States)

    Ramamurthy, Rajaraman; Kottayasamy Seenivasagam, Rajkumar; Shanmugam, Subbiah; Palanivelu, Kathirvelkumaran

    2014-09-01

    Sentinel Lymph Node (SLN) biopsy using a combination of radioisotopes and blue dyes have a good accuracy rate in predicting subclinical neck nodal metastases in head and neck cancers. However, the limited availability of lymphoscintigraphy facilities in India requires exploration of alternative methods of SLN detection. We evaluated the feasibility of using methylene blue dye alone in detecting SLN in cN0 early oral cancers. 32 patients with cN0 early (T1, T2) oral squamous cell cancers underwent SLN biopsy using peri tumoural methylene blue dye injection. Blue dye stained (SLN) nodes were sent for frozen section analyses. Patients who had microscopic metastases in SLN underwent modified radical neck dissections and the rest underwent selective neck dissections. Paraffin sections and IHC studies were done on all nodes. SLN was identified in 29 patients (Identification rate = 90.6 %) of which SLN was positive for metastases on frozen section in 5 patients. The sensitivity, specificity and NPV of SLN with frozen section were 80 %, 95.8 % and 95.8 % respectively. IHC with cytokeratins increased the sensitivity (100 %) and NPV (100 %) at the loss of specificity (87.5 %). Methylene blue dye alone can be successfully used for SLN identification in early oral cancers with a good accuracy and sensitivity. This method will be of use especially in resource limited countries and centres where nuclear medicine facilities are not widely available. However, it has to be validated by larger randomised multi institutional trials for wider applicability. Immunohistochemistry increases the sensitivity and negative predictive value of SLN but its applicability in real time decision making is limited.

  6. 聚次甲基蓝膜的生长及性质%Growth of Poly(methylene blue) Film and Properties of the Film

    Institute of Scientific and Technical Information of China (English)

    刘金翠; 穆绍林; 李永舫

    2001-01-01

    The in situ spectroelectrochemical experiment shows that an absorption peak at 580.5 nm attributable to poly(methylene blue) grows slowly at the beginning of the electrolysis of methylene blue, and then this peak grows more quickly. The visible spectra prove that there are two absorption peaks at 580.5 and 690.2 nm respectively for the mixture solution after electrolysis. The former one indicates that poly(methylene blue)polymerized on the ITO electrode is partly soluble; the latter one is attributed to a water-soluble polymer since it completely dissolves in the aqueous solution. The result from the rotating ring-disk electrode identifies that an intermediate is produced at the disk electrode, which is collected at the ring electrode. The ring current increases with decreasing the ring potential and with increasing the rotation rate. Thus, the intermediate is a species carrying a positive charge and not too stable.The result from the XPS experiment shows that the anions can be doped into poly(methylene blue) film and dedoped from it during oxidation and reduction processes. The results from the impedance experiment indicate that the charge transfer impedance of poly(methylene blue) decreases with decreasing potential.

  7. Optimization of pH and direct imaging conditions of complexed methylene blue sensitized poly(vinyl chloride) films

    Indian Academy of Sciences (India)

    M Ushamani; N G Leenadeenja; K Sreekumar; C Sudha Kartha; Rani Joseph

    2003-04-01

    Significant results of our experimental investigations on the dependence of pH on real time transmission characteristics on recording media fabricated by doping PVC with complexed methylene blue are presented. The optimum pH value for faster bleaching was found to be 4.5. In typical applications, the illumination from one side, normal to the surface of this material, initiates a chemical sequence that records the incident light pattern in the polymer. Thus direct imaging can be successfully done on this sample. The recorded letters were very legible with good contrast and no scattering centres. Diffraction efficiency measurements were also carried out on this material.

  8. Synthesis, Characterization and Antimicrobial Activity of Metal Chelates of 5-[1(H-Benzotriazole methylene]-8-quinolinol

    Directory of Open Access Journals (Sweden)

    H. S. Patel

    2009-01-01

    Full Text Available 5-Chloromethyl-8-quinolinol was condensed stoichiometrically with benzotriazole in presence of potassium carbonate. The resulting 5-[1(H-benzo triazole methylene]-8-quinolinol (BTMQ was characterized by elemental analysis and spectral studies. The transition metal chelates viz. Cu2+, Ni2+, Co3+, Mn2+ and Zn2+ of BTMQ were prepared and characterized by metal-ligand (M:L ratio, IR and reflectance spectral studies and magnetic properties. The antifungal activity of BTMQ and its metal chelates was screened against various fungi. The results show that all these samples are good antifungal agents.

  9. Fe(III/TiO2-Montmorillonite Photocatalyst in Photo-Fenton-Like Degradation of Methylene Blue

    Directory of Open Access Journals (Sweden)

    Is Fatimah

    2015-01-01

    Full Text Available A photodegradation process of methylene blue (MB in aqueous solution using Fe(III/TiO2-montmorillonite photocatalyst is presented. The photocatalyst material was prepared using Indonesian natural montmorillonite in TiO2 pillarization process followed by Fe(III ion exchange. Kinetic study on MB degradation was conducted and evaluated by three kinetic models: the pseudo-first- and second-order equations and the Elovich equation. From the results, it is concluded that the degradation under the photo-Fenton-like process utilizing Fe(III/TiO2-montmorillonite photocatalyst conformed to the Elovich kinetic model.

  10. Research on the Adsorption of Methylene Blue with Rice Husk Ash Aided by Ion Beam Etching Technique

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the mechanism of the removal effect of methylene blue(MB) by rice husk ash(RHA).[Method] The effects of contact time and pH on the adsorption of MB by rice husk ash were investigated,and the mechanism was discussed.[Result] RHA exhibited a remarkable ability on the adsorption of MB.The process of adsorption reached the equilibrium after 30 min,at about pH 9.The adsorption effect was explored with the aid of ion beam etching technique,which displayed that there were two main ...

  11. Synthesis and highly visible-induced photocatalytic activity of CNT-CdSe composite for methylene blue solution

    Directory of Open Access Journals (Sweden)

    Chen Ming-Liang

    2011-01-01

    Full Text Available Abstract Carbon nanotube-cadmium selenide (CNT-CdSe composite was synthesized by a facile hydrothermal method derived from multi-walled carbon nanotubes as a stating material. The as-prepared products were characterized by X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis, transmission electron microscopy (TEM, and UV-vis diffuse reflectance spectrophotometer. The as-synthesized CNT-CdSe composite efficiently catalyzed the photodegradation of methylene blue in aqueous solutions under visible-light irradiation, exhibiting higher photocatalytic activity.

  12. Rapid Photocatalytic Degradation of Methylene Blue under High Photon Flux UV Irradiation: Characteristics and Comparison with Routine Low Photon Flux

    OpenAIRE

    2012-01-01

    This study examined the photocatalytic degradation efficiency under high UV photon flux (intensity normalized by photon energy) irradiation; the incident UV photon flux was 1 . 7 1 × 1 0 − 6 − 3 . 1 3 × 1 0 − 6 einstein c m − 2   s − 1 made by a super high-intensity UV apparatus. A comparative study between high photon flux photocatalytic process and routine low photon flux photocatalytic process for methylene blue degradation has been made in aqueous solution. The experimental results showed...

  13. Synthesis of CdS Sensitized TiO2 Photocatalysts: Methylene Blue Adsorption and Enhanced Photocatalytic Activities

    OpenAIRE

    A. B. Makama; A. Salmiaton; E. B. Saion; T. S.Y. Choong; Abdullah, N

    2016-01-01

    A series of CdS/TiO2 nanocomposites with different Cd to Ti molar ratio were synthesized from P25-TiO2 nanopowder using microwave-assisted hydrothermal method. The as-produced powders were characterized by XRD, electron microscopy, EDX, and UV-Vis diffuse reflectance spectroscopy. The adsorption capacity and photocatalytic activity of the samples were investigated using methylene blue as a model pollutant. Sorption tests revealed that the adsorption of MB onto the samples obeys the Freundlich...

  14. Reactions of 3-Formylchromone with Active Methylene and Methyl Compounds and Some Subsequent Reactions of the Resulting Condensation Products

    Directory of Open Access Journals (Sweden)

    M. Lácova

    2005-08-01

    Full Text Available This review presents a survey of the condensations of 3-formylchromone with various active methylene and methyl compounds, e.g. malonic or barbituric acid derivatives, five-membered heterocycles, etc. The utilisation of the condensation products for the synthesis of different heterocyclic systems, which is based on the ability of the γ-pyrone ring to be opened by the nucleophilic attack is also reviewed. Finally, the applications of microwave irradiation as an unconventional method of reaction activation in the synthesis of condensation products is described and the biological activity of some chromone derivatives is noted.

  15. Phytogenic feed additives as alternative to antibiotic growth promoters in broiler chickens

    Directory of Open Access Journals (Sweden)

    Ganapathi Raj Murugesan

    2015-08-01

    Full Text Available The recent trend toward reduction of antibiotic growth promoters (AGP in North American poultry diets has put tremendous pressure on the industry to look for viable alternatives. In this context, phytogenic feed additives (PFA are researched to improve gut health and thereby performance. An experiment was conducted with the objective to evaluate the effects of PFA as an alternative to AGP on small intestinal histomorphology, cecal microbiota composition, nutrient digestibility, and growth performance in broiler chickens. A total of 432, day-old Vencobb 400 broiler chicks were randomly assigned to one of three dietary groups, each consisting of 12 replicate pens (n = 12 chicks/pen. The chicks were fed a corn-soybean meal based control (CON, CON + 500 mg/kg of AGP (bacitracin methylene disalicylate containing 450 mg active BMD/g, or CON + 150 mg/kg of proprietary blend of PFA (Digestarom® Poultry until 39 days of age when samples were collected. Birds fed either AGP or PFA had increased villus height in all three segments of the small intestine in comparison to the birds fed CON (P ≤ 0.05. Furthermore, the PFA fed birds had significantly increased villus height and lower crypt depth compared to AGP fed birds (P ≤ 0.05. Birds fed either additive also had increased total tract digestibility of dry matter, crude protein and ether extract (P ≤ 0.05. The strong effect of the PFA on villus height in the jejunum may suggest augmented nutrient absorption in PFA fed birds. Although both additives reduced total cecal counts of anaerobic bacteria and Clostridium spp., PFA alone reduced the total coliform count while increasing the Lactobacillus spp. count (P ≤ 0.05. These results suggest the establishment of beneficial microbial colonies in PFA fed birds. Overall both PFA and AGP increased body weight gain while lowering the feed conversion ratio (P ≤ 0.05. Hence data from this experiment demonstrate the efficacy of PFA as a substitute to AGP in

  16. Turkey knockdown in successive flocks.

    Science.gov (United States)

    Evans, R D; Edson, R K; Watkins, K L; Robertson, J L; Meldrum, J B; Novilla, M N

    2000-01-01

    Turkey knockdown was diagnosed in three of five flocks of hen turkeys on a single farm within a 12-mo period. The age of birds in the flocks affected ranged from 6 wk 2 days to 7 wk 4 days. The attack rate ranged from 0.02% to 0.30% with a case fatality rate in affected birds ranging from 0 to 74%. The diagnosis was made on the basis of clinical signs and histopathologic lesions associated with knockdown. The feed in all flocks contained bacitracin methylene disalicylate and monensin (Coban). Affected birds were recumbent, demonstrated paresis, and were unable to vocalize. Postmortem examination revealed few significant lesions although pallor of the adductor muscles and petechiation in adductor and gastrocnemius muscles were noted. Birds that had been recumbent for extended periods were severely dehydrated. Consistent microscopic lesions included degeneration, necrosis, and regeneration of adductor, gastrocnemius, and abdominal muscles. No lesion in cardiac tissue was noted. Results of our investigation indicated that changes in water consumption, vitamin E status, and brooder to finisher movement correlated with the occurrence of knockdown. Turkey knockdown was defined in 1993 as any condition identified in a turkey flock that has affected the neuromuscular system to a degree that a turkey is unable to walk or stand. This definition was later modified to...neuromuscular or skeletal systems to a degree that a turkey is unable to walk or stand properly. Knockdown may be associated with numerous feed, management, or disease factors alone or in combination. Dosage of monensin, feed restriction/gorging, water restriction, heat stress, copper, mycotoxins, sodium chloride in feed, and sulfa drugs have all been suggested as contributing factors; however, laboratory studies to duplicate this have not been successful. This report presents observations from a single farm at which three of five hen flocks in a single year experienced knockdown. When a flock was reported as

  17. Effect of supplemental vitamins and trace minerals on performance and carcass quality in finishing pigs.

    Science.gov (United States)

    Edmonds, M S; Arentson, B E

    2001-01-01

    Two trials with finishing pigs (PIC line 355 x Camborough 22) were conducted to evaluate the effects of vitamin and trace mineral (VTM) supplement deletions on performance, carcass quality, and tissue nutrient levels. Trial 1, a 3 x 2 factorial arrangement of treatments involving three VTM supplement regimens and two stress regimens, was conducted for 12 wk with 252 pigs (mixed sex). Average initial weight of pigs was 54 kg. The VTM regimens consisted of control (adequate level of VTM throughout trial), VTM deleted for the final 6 wk, and VTM deleted for entire 12 wk of the trial. The stress regimens consisted of leaving half the treatments in their original location or moving the other half of the treatments to a new pen location every 3 wk. There were three replications (pens) per treatment with 14 pigs per pen (0.80 m2). Diets were medicated with bacitracin methylene disalicylate. Overall, there were no treatment differences (P > 0.05) for ADG, ADFI, gain:feed ratio, longissimus muscle area, or last-rib backfat. However, there was a greater than 75% decrease (P < 0.001) in vitamin E content of longissimus muscle from deleting VTM for 6 or 12 wk. Trial 2, a 3 x 2 factorial arrangement of treatments involving three VTM regimens and two genders, was conducted for 12 wk with 306 pigs. Average initial weight of pigs was 58 kg. The VTM regimens were identical to those used in Trial 1. Each treatment consisted of three gender replications of 17 pigs per pen (0.66 m2), and all diets were unmedicated. Overall, pigs fed diets without VTM for 12 wk had lower (P < 0.06) ADG than those fed the control diets. Vitamin E content of the ham muscle was reduced by greater than 50% (P < 0.001) when pigs were fed diets without VTM for 6 or 12 wk compared with those fed the control diet. Concentrations of copper in ham muscle were reduced (P < 0.05) in pigs fed diets without VTM. These data suggest that deleting VTM during the finishing stage markedly lowers the vitamin E content of

  18. Removal of Methylene Blue Dye from Synthetic Wastewater with Bone Char

    Directory of Open Access Journals (Sweden)

    Gh Ghanizadeh

    2009-09-01

    Full Text Available "n "n "nBackgrounds and Objectives: Dyes  are  organic  materials  with  complex structures, toxic,  carcinogenic, teratogenic,nonbiodegredable properties and!the most!important pollutants of textile industrial wastewaters. The goal of this study was to survey the feasibility application of bone char (BC as a sorbent for the  of methylene blue (MB from synthetic wastewater.The sub goals of the research!were to determine!the adsorption isotherm, !effects of primary concentration of dye, adsorbent!dose, contact!time, and pH for the adsorption of MB with BC."nMaterials and Methods: BC was prepared under laboratory conditions by using of electrical furnace at 400°C for 2h. The prepared BC was crushed and pulverized by standard ASTM sieves with range of 10-16mesh(1.18-2mm.The  chemical composition  and  solid  structure  of BC was  analyzed using X-ray diffraction(XRD and  scanning  electronic  microscopy (SEM. Measurement  of  the surface area was carried out by N2 gas via BET isotherm and Belsorb software. The concentration of dye was measured by photometric!method (663nm."nResults: Predominant!compositionof BC is calcium hydroxyl apatite (Ca5 (PO43OH with 14m2/g surface area. The results of this study showed that increasing of primary concentration of dye, adsorbent dose and pH (5 to12 would lead to increasing of adsorption/removal of MB dye.Equilibration of dye adsorption was reached at lapse of 2h andoptimum pH for adsorption of MB with BC found in the rage of 8.5-12.Adsorption of MB witht BC complies witht freundlich isotherm(R2:0.99."nConclusion: Bone char is a cheap component that can be used as an adsorbent in water and wastewater treatment. Based on optimum pH of 8.5-12 found for the removal of MB and the fact that many of textile!industrial wastewaters have an alkaline pH, this adsorbent can be!used for the removal of dyes from these wastewaters.

  19. Study of epigenetic properties of Poly(HexaMethylene Biguanide) hydrochloride (PHMB).

    Science.gov (United States)

    Creppy, Edmond E; Diallo, Aboudoulatif; Moukha, Serge; Eklu-Gadegbeku, Christophe; Cros, Daniel

    2014-08-08

    Poly(HexaMethylene Biguanide) hydrochloride (PHMB) CAS No. [32289-58-0] is a particularly effective member of the biguanides antiseptic chemical group, and has been in use since the early fifties in numerous applications. It has been proposed that PHMB be classified as a category 3 carcinogen although PHMB is not genotoxic. It has been hypothesized that PHMB may have epigenetic properties effects, including non-genotoxic modifications of DNA bases, DNA methylation and mitogenic cytokine production. These properties have been assessed in vitro using 3 cell types: Caco-2 cells (from a human colon adenocarcinoma) with a non-functional p53 gene. (∆p53: mut p53), N2-A (Neuro-2A cells, mouse neural cells), the brain being a possible target organ in rodents and HepG2 cells (human hepatocellular carcinoma) with functional p53 gene. From the concentration 1 µg/mL up to 20 µg/mL of PHMB, no effect was observed, either growth stimulation or inhibition. Viability testing using neutral red led to an IC 50 of 20-25 µg/mL after treatment with PHMB for 3 h, whereas the MTT test led to IC50 values of 80 µg/mL, 160 µg/mL and 160 µg/mL respectively for HepG2 cells, Neuro-2A cells and Caco-2 cells. PHMB does not induce significant oxidative stress (production of MDA or lipoperoxidation, nor does it induce hydroxylation of DNA (8-OH-dG) and/or its hypermethylation (m5dC), the latter being strongly implicated in DNA replication and regulation and cell division. PHMB does not induce significant production of mitogenic cytokines such as TNF-α (tumor necrosis factor), interleukins (IL-1 alpha), and the transcription factor nuclear factor kappa B (NF-κB) which can cause either apoptosis or stimulate the growth of transformed cells or tumors. Instead, from concentrations of 20 to 100 µg/mL, PHMB kills cells of all types in less than 3 h. The expression of genes involved in the mechanisms of cell death induced by PHMB, including p53, the pro apoptotic gene bax and others, the anti

  20. Methylene-bis[(aminomethyl)phosphinic acids]: synthesis, acid-base and coordination properties.

    Science.gov (United States)

    David, Tomáš; Procházková, Soňa; Havlíčková, Jana; Kotek, Jan; Kubíček, Vojtěch; Hermann, Petr; Lukeš, Ivan

    2013-02-21

    Three symmetrical methylene-bis[(aminomethyl)phosphinic acids] bearing different substituents on the central carbon atom, (NH(2)CH(2))PO(2)H-C(R(1))(R(2))-PO(2)H(CH(2)NH(2)) where R(1) = OH, R(2) = Me (H(2)L(1)), R(1) = OH, R(2) = Ph (H(2)L(2)) and R(1),R(2) = H (H(2)L(3)), were synthesized. Acid-base and complexing properties of the ligands were studied in solution as well as in the solid state. The ligands show unusually high basicity of the nitrogen atoms (log K(1) = 9.5-10, log K(2) = 8.5-9) if compared with simple (aminomethyl)phosphinic acids and, consequently, high stability constants of the complexes with studied divalent metal ions. The study showed the important role of the hydroxo group attached to the central carbon atom of the geminal bis(phosphinate) moiety. Deprotonation of the hydroxo group yields the alcoholate anion which tends to play the role of a bridging ligand and induces formation of polynuclear complexes. Solid-state structures of complexes [H(2)N=C(NH(2))(2)][Cu(2)(H(-1)L(2))(2)]CO(3)·10H(2)O and Li(2)[Co(4)(H(-1)L(1))(3)(OH)]·17.5H(2)O were determined by X-ray diffraction. The complexes show unexpected geometries forming dinuclear and cubane-like structures, respectively. The dinuclear copper(II) complex contains a bridging μ(2)-alcoholate group with the (-)O-P(=O)-CH(2)-NH(2) fragments of each ligand molecule chelated to the different central ion. In the cubane cobalt(II) complex, one μ(3)-hydroxide and three μ(3)-alcoholate anions are located in the cube vertices and both phosphinate groups of one ligand molecule are chelating the same cobalt(II) ion while each of its amino groups are bound to different neighbouring metal ions. All such three metal ions are bridged by the alcoholate group of a given ligand.

  1. Quantitation of 4,4′-methylene diphenyl diisocyanate human serum albumin adducts

    Directory of Open Access Journals (Sweden)

    Leah G. Luna

    2014-01-01

    Full Text Available 4,4′-Methylene diphenyl diisocyanate (herein 4,4′-MDI is used in the production of polyurethane foams, elastomers, coatings, adhesives and the like for a wide range of commercial products. Occupational exposure to MDI levels above current airborne exposure limits can elicit immune mediated hypersensitivity reactions such as occupational asthma in sensitive individuals. To accurately determine exposure, there has been increasing interest in developing analytical methods to measure internal biomarkers of exposure to MDI. Previous investigators have reported methodologies for measuring MDI diamine metabolites and MDI-Lysine (4,4′-MDI-Lys adducts. The purpose of this study was to develop and validate an ultra performance liquid chromatography isotope dilution tandem mass spectrometry (UPLC-ID/MS/MS quantitation method via a signature peptide approach to enable biomonitoring of 4,4′-MDI adducted to human serum albumin (HSA in plasma. A murine, anti-4,4′-MDI monoclonal IgM antibody was bound to magnetic beads and utilized for enrichment of the MDI adducted HSA. Following enrichment, trypsin digestion was performed to generate the expected 414 site (primary site of adduction 4,4′-MDI-adducted HSA signature peptide that was quantified by UPLC-ID/MS/MS. An Agilent 6530 UPLC/quadrupole time of flight MS (QTOF system was utilized for intact adducted protein analysis and an Agilent 6490 UPLC/MS/MS system operated in multiple reaction monitoring (MRM mode was utilized for quantification of the adducted signature peptide biomarker both for in chemico and worker serum samples. Worker serum samples were initially screened utilizing the previously developed 4,4′-MDI-Lys amino acid method and results showed that 12 samples were identified as quantifiable for 4,4′-MDI-Lys adducts. The signature peptide adduct approach was applied to the 12 worker samples identified as quantifiable for 4,4′-MDI-Lys adducts. Results indicated no positive results

  2. Methylene bromide chemistry and photochemistry on rutile TiO2(110)

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, Michael A.; Robbins, Matthew D.

    2011-10-01

    The chemistry and photochemistry of methylene bromide (CD2Br2) on the rutile TiO2(110) surface was probed using temperature programmed desorption (TPD). CD2Br2 desorbed in three desorption states at 145, 160 and 250 K tentatively assigned to desorption from the multilayer, from an η1-CD2Br2 species and a bridging η2-CD2Br2 species, respectively. The latter two TPD states presumably involve binding of CD2Br2 molecules to the surface through Br coordination at five-coordinate Ti4+ surface sites. The 160 and 250 K TPD states saturated at coverages of 1.0 and 0.33 ML, respectively, where 1 ML is equivalent to the surface Ti4+ site density (5.2 × 1014 cm- 2). No thermal decomposition of CD2Br2 was observed on either the clean surface or with preadsorbed O2. UV irradiation of CD2Br2 on TiO2(110) resulted in predominately photodesorption, with trace amounts of photodecomposition evidenced in TPD. The rate of CD2Br2 photodesorption from TiO2(110) occurred with a low cross section (~ 2 × 10- 21 cm2) similar to that expected from direct optical excitation of CD2Br2. This observation suggests that charge carriers generated in TiO2(110) were no more effective in activating adsorbed CD2Br2 molecules than would be expected through direct molecular excitation. Finally, these findings suggest that photocatalytic destruction of halocarbons such as CD2Br2 on TiO2 may preferentially occur though indirect processes (such as OH radical attack) as opposed to direct electron transfer processes involving charge carriers generated in TiO2 by bandgap excitation.

  3. Characterization of the interaction of a mono-6-thio-β-cyclodextrin-capped CdTe quantum dots-methylene blue/methylene green system with herring sperm DNA using a spectroscopic approach.

    Science.gov (United States)

    Shen, Yizhong; Liu, Shaopu; Wang, Lei; Yin, Pengfei; He, Youqiu

    2014-11-01

    Novel, water-soluble CdTe quantum dots (QDs) capped with β-cyclodextrin (β-CD) and ~ 4.0 nm in diameter were synthesized in aqueous solution, and characterized using transmission electron microscopy (TEM). A fluorescence-sensing system based on the photoinduced electron transfer (PET) of (mono-6-thio-β-CD)-CdTe QDs was then designed to measure the interaction of phenothiazine dyes [methylene blue (MB) and methylene green (MG)] with herring sperm DNA (hsDNA). This fluorescence-sensing system was based on a fluorescence "OFF-ON" mode. First, MB/MG adsorbed on the surface of (mono-6-thio-β-CD)-CdTe QDs effectively quenches the fluorescence of (mono-6-thio-β-CD)-CdTe QDs through PET. Then, addition of hsDNA restores the fluorescence intensity of (mono-6-thio-β-CD)-CdTe QDs, because hsDNA can bind with MB/MG and remove it from the as-prepared (mono-6-thio-β-CD)-CdTe QDs. In addition, detailed reaction mechanisms of the (mono-6-thio-β-CD)-CdTe QDs-MB/MG-hsDNA solution system were studied using optical methods, by comparison with the TGA-CdTe QDs-MB/MG-hsDNA solution system.

  4. Design and synthesis of metal complexes of (2E)-2-[(2E)-3-phenylprop-2-en-1-ylidene]hydrazinecarbothioamide and their photocatalytic degradation of methylene blue.

    Science.gov (United States)

    Krishna, P Murali; Reddy, N B Gopal; Kottam, Nagaraju; Yallur, B C; Katreddi, Hussain Reddy

    2013-01-01

    The photocatalytic degradation has been considered to be an efficient process for the degradation of organic pollutants, which are present in the effluents released by industries. The photocatalytic bleaching of cationic dye methylene blue was carried out spectrometrically on irradiation of UV light using Cu(II), Ni(II), and Co(II) complexes of (2E)-2-[(2E)-3-phenylprop-2-en-1-ylidene]hydrazinecarbothioamide (HL). The effects of pH and metal ion were studied on the efficiency of the reaction. Cu(II) complex shows better catalytic activity and the highest percentage degradation (~88.8%) of methylene blue was observed at pH 12. A tentative mechanism has also been proposed for the photocatalytic degradation of methylene blue.

  5. Design and Synthesis of Metal Complexes of (2E-2-[(2E-3-Phenylprop-2-en-1-ylidene]hydrazinecarbothioamide and Their Photocatalytic Degradation of Methylene Blue

    Directory of Open Access Journals (Sweden)

    P. Murali Krishna

    2013-01-01

    Full Text Available The photocatalytic degradation has been considered to be an efficient process for the degradation of organic pollutants, which are present in the effluents released by industries. The photocatalytic bleaching of cationic dye methylene blue was carried out spectrometrically on irradiation of UV light using Cu(II, Ni(II, and Co(II complexes of (2E-2-[(2E-3-phenylprop-2-en-1-ylidene]hydrazinecarbothioamide (HL. The effects of pH and metal ion were studied on the efficiency of the reaction. Cu(II complex shows better catalytic activity and the highest percentage degradation (~88.8% of methylene blue was observed at pH 12. A tentative mechanism has also been proposed for the photocatalytic degradation of methylene blue.

  6. Insertion of O-H Bond of Rh(Ⅱ)-methylene Carbene into Alcohols: A Stepwise Mechanism More Plausible than a Concerted Mechanism

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The mechanisms of insertion of O-H bond of Rh( Ⅱ ) -methylene carbene into methanol and ethanol were studied by using B3LYP functional both in gas phase and in CH2Cl2. The formation of free alcoholic oxonium ylides is found to be impossible. Alcoholic oxonium ylide are formed as the intermediates before both the stepwise and the concerted transition states of insertion of O-H bond of Rh( Ⅱ ) -methylene carbene into methanol and ethanol. With regard to the mechanisms of insertion of O-H of Rh( Ⅱ ) -methylene carbene into alcohols, analysis of the energy barriers of the two mechanisms indicate that the stepwise mechanism is more plausible than the concerted mechanism.

  7. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of methylene blue active substances by spectrophotometry

    Science.gov (United States)

    Burkhardt, Mark R.; Cinotto, Pete J.; Frahm, Galen W.; Woodworth, Mark T.; Pritt, Jeffrey W.

    1995-01-01

    A method for the determination of methylene blue active substances in whole-water samples by liquid-liquid extraction and spectrophotometric detection is described. Sulfate and sulfonate-based surfectants are reacted with methylene blue to form a blue-colored complex. The complex is extracted into chloroform, back-washed with an acidified phosphate-based buffer solution, and measured against external standards with a probe spectrophotometer. The method detection limt for routine analysis is 0.02 milligram per liter. The precision is plus/minus 10 percent relative standard deviation. The positive bias from nitrate and chloride and U.S. Geological Survey method O-3111-83 for methylene blue active substances is minized by adding a back-washing step.

  8. A methylene blue-assisted technique for harvesting lymph nodes after radical surgery for gastric cancer: a prospective, randomized, controlled study.

    Science.gov (United States)

    Aoyama, Toru; Fujikawa, Hirohito; Cho, Haruhiko; Ogata, Takashi; Shirai, Junya; Hayashi, Tsutomu; Rino, Yasushi; Masuda, Munetaka; Oba, Mari S; Morita, Satoshi; Yoshikawa, Takaki

    2015-02-01

    Harvesting lymph nodes (LNs) after gastrectomy is essential for accurate staging. This trial evaluated the efficiency and quality of a conventional method and a methylene blue-assisted method in a randomized manner. The key eligibility criteria were as follows: (i) histologically proven adenocarcinoma of the stomach; (ii) clinical stage I-III; (iii) R0 resection planned by gastrectomy with D1+ or D2 lymphadenectomy. The primary endpoint was the ratio of the pathologic number of harvested LNs per time (minutes) as an efficacy measure. The secondary endpoint was the number of harvested LNs, as a quality measure. Between August 2012 and December 2012, 60 patients were assigned to undergo treatment using the conventional method (n=29) and the methylene blue dye method (n=31). The baseline demographics were mostly well balanced between the 2 groups. The number of harvested LNs (mean±SD) was 33.6±11.9 in the conventional arm and 43.4±13.9 in the methylene blue arm (P=0.005). The ratio of the number of the harvested LNs per time was 1.12±0.46 LNs/min in the conventional arm and 1.49±0.59 LNs/min in the methylene blue arm (P=0.010). In the subgroup analyses, the quality and efficacy were both superior for the methylene blue dye method compared with the conventional method. The methylene blue technique is recommended for harvesting LNs during gastric cancer surgery on the basis of both the quality and efficacy.

  9. A study on the adsorption of methylene blue onto gum ghatti/TiO2 nanoparticles-based hydrogel nanocomposite.

    Science.gov (United States)

    Mittal, Hemant; Ray, Suprakas Sinha

    2016-07-01

    The objective of this work was to study the isotherm and kinetic models for the adsorption of methylene blue (MB) onto a TiO2 nanoparticle (TiO2NP)-containing hydrogel nanocomposite (HNC) of polyacrylamide-grafted gum ghatti (PAAm-g-Gg). The grafting of PAAm onto Gg was conducted using N,N'-methylene-bis-acrylamide (MBA) as a crosslinker, and different weight percentages of TiO2NPs were incorporated into the hydrogel matrix during the grafting reaction. The graft co-polymerization and the formation of the HNC were confirmed using FTIR, XRD, BET, SEM, TEM and EDS analyses. The adsorption of MB was studied in batch mode and it was found to be highly dependent on solution pH, ionic strength temperature and adsorbent loading. The MB-adsorption process followed the pseudo-second-order rate model and Langmuir adsorption isotherm with a maximum adsorption capacity of 1305.5mgg(-1). Thermodynamic studies revealed that the adsorption of MB onto the HNC surface was spontaneous, endothermic and through a process of physisorption. The results also showed that the HNC was much more effective for the adsorption of cationic dyes than anionic dyes, and it retained its original adsorption capacity for five successive cycles of adsorption-desorption. In conclusion, the hydrogel nanocomposite showed huge potential for remediating industrial wastewater polluted by toxic cationic dyes.

  10. SrTiO3 Nanocube-Doped Polyaniline Nanocomposites with Enhanced Photocatalytic Degradation of Methylene Blue under Visible Light

    Directory of Open Access Journals (Sweden)

    Syed Shahabuddin

    2016-02-01

    Full Text Available The present study highlights the facile synthesis of polyaniline (PANI-based nanocomposites doped with SrTiO3 nanocubes synthesized via the in situ oxidative polymerization technique using ammonium persulfate (APS as an oxidant in acidic medium for the photocatalytic degradation of methylene blue dye. Field emission scanning electron microscopy (FESEM, transmission electron microscopy (TEM, thermogravimetric analysis (TGA, X-ray diffraction (XRD, UV–Vis spectroscopy, Brunauer–Emmett–Teller analysis (BET and Fourier transform infrared spectroscopy (FTIR measurements were used to characterize the prepared nanocomposite photocatalysts. The photocatalytic efficiencies of the photocatalysts were examined by degrading methylene blue (MB under visible light irradiation. The results showed that the degradation efficiency of the composite photocatalysts that were doped with SrTiO3 nanocubes was higher than that of the undoped polyaniline. In this study, the effects of the weight ratio of polyaniline to SrTiO3 on the photocatalytic activities were investigated. The results revealed that the nanocomposite P-Sr500 was found to be an optimum photocatalyst, with a 97% degradation efficiency after 90 min of irradiation under solar light.

  11. Methylene blue degradation by NaTaO3 sol-gel doped with Sm and La.

    Science.gov (United States)

    Torres-Martínez, Leticia M; Cruz-López, Arquímedes; Juárez-Ramírez, Isaías; Meza-de la Rosa, Ma Elena

    2009-06-15

    In this work, NaTaO(3) compounds doped with 1M% of La and Sm, were prepared by the sol-gel (SG) method and solid state (SS) reaction; and tested as photocatalysts on the degradation of methylene blue (MB) under UV light. The structural characterization by X-ray powder diffraction revealed that the crystallization of the NaTaO(3) phase prepared by the sol-gel method started at 600 degrees C, reaching maximum crystallization at 800 degrees C. It was determined that the presence of Sm and La retard the crystallization of the NaTaO(3) phase. On the other hand, the compounds synthesized in this work showed particle sizes in the nanometric scale, as it was observed by scanning electron microscopy (SEM). The specific surface area of the compounds synthesized by the sol-gel method, showed values 4 times higher than those obtained by the solid state reaction, favoring their functional and photocatalytic performance in the methylene blue degradation. In addition, the best photocatalytic performance was shown by the NaTaO(3) doped with Sm and heated at 600 degrees C, having a half-life time of 65 min.

  12. Preparation of a Modified Nanoalumina Sorbent for the Removal of Alizarin Yellow R and Methylene Blue Dyes from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Wasan T. Al-Rubayee

    2016-01-01

    Full Text Available A modified form of γ-alumina nanoparticles prepared by immobilization of 2,4-dinitrophenyl hydrazine on γ-alumina nanoparticles coated with sodium dodecyl sulfate (DNPH-γ-alumina for the removal of the anionic dye (Alizarin yellow R and cationic dye (Methylene blue from aqueous solutions has been investigated. The FTIR, SEM, TEM, XRD, BET, and BJH analysis techniques indicate that the modification reaction has occurred. Batch adsorption study revealed that 0.05 g amount of the modified adsorbent was capable of removing 95.6% and 65.6% of Alizarin yellow (AY and Methylene blue (MB dyes, respectively, in 60 min. The experimental equilibrium data showed that Langmuir isotherm applies well for describing the adsorption behavior, and the maximum adsorption capacity was found to be 47.8 mg/g and 32.8 mg/g for AY and MB on DNPH-γ-alumina, respectively. Kinetic studies showed best applicability of the second-order kinetic model. The DNPH-γ-alumina adsorbent proved capability, effectiveness, and selectivity for the removal of Alizarin yellow R dye. Therefore, it is possible to increase the efficiency of an adsorbent for the removal of pollutants by applying a modification to the surface of the adsorbent, and DNPH as a modifier proved efficient for the removal of a wider range of pollutants including metal ions and dye compounds.

  13. Methylene blue degradation by NaTaO{sub 3} sol-gel doped with Sm and La

    Energy Technology Data Exchange (ETDEWEB)

    Torres-Martinez, Leticia M., E-mail: letorre@fic.uanl.mx [Departmento de Ecomateriales y Energia, Facultad de Ingenieria Civil, Universidad Autonoma de Nuevo Leon, Cd. Universitaria, S/N San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Cruz-Lopez, Arquimedes; Juarez-Ramirez, Isaias; Meza-de la Rosa, Ma. Elena [Departmento de Ecomateriales y Energia, Facultad de Ingenieria Civil, Universidad Autonoma de Nuevo Leon, Cd. Universitaria, S/N San Nicolas de los Garza, Nuevo Leon 66450 (Mexico)

    2009-06-15

    In this work, NaTaO{sub 3} compounds doped with 1 M% of La and Sm, were prepared by the sol-gel (SG) method and solid state (SS) reaction; and tested as photocatalysts on the degradation of methylene blue (MB) under UV light. The structural characterization by X-ray powder diffraction revealed that the crystallization of the NaTaO{sub 3} phase prepared by the sol-gel method started at 600 deg. C, reaching maximum crystallization at 800 deg. C. It was determined that the presence of Sm and La retard the crystallization of the NaTaO{sub 3} phase. On the other hand, the compounds synthesized in this work showed particle sizes in the nanometric scale, as it was observed by scanning electron microscopy (SEM). The specific surface area of the compounds synthesized by the sol-gel method, showed values 4 times higher than those obtained by the solid state reaction, favoring their functional and photocatalytic performance in the methylene blue degradation. In addition, the best photocatalytic performance was shown by the NaTaO{sub 3} doped with Sm and heated at 600 deg. C, having a half-life time of 65 min.

  14. Preparation and Characterization of Nanoscale Zero-Valent Iron-Loaded Porous Sepiolite for Decolorizing Methylene Blue in Aqueous Solutions

    Science.gov (United States)

    Wang, Qingmiao; Ren, Gaofeng; Jia, Feifei; Song, Shaoxian

    2017-02-01

    The preparation and characterization of nanoscale zero-valent iron-loaded porous sepiolite, as well as its application in the decolorization of methylene blue in aqueous solution, have been studied in this work through the measurements of field emission scanning electron microscope with energy dispersive spectrometry, x-ray photoelectron spectrometry, Fourier transform infrared spectroscopy and specific surface area. The results showed that nanoscale zero-valent iron particles were successfully loaded on the surface and interior pores of sepiolite through physical adsorption. It was revealed that the decoloration capacity of methylene blue on nanoscale zero-valent iron-loaded porous sepiolite in water was comparable to that of nanoscale zero-valent iron, and nine times higher than that of natural sepiolite. This indicates that porous sepiolite was a good supporter for the loading of nanoscale zero-valent iron and nanoscale zero-valent iron-loaded sepiolite was a good decolorant because of its high decoloration efficiency and easy separation.

  15. Novel adsorbent from agricultural waste (cashew NUT shell for methylene blue dye removal: Optimization by response surface methodology

    Directory of Open Access Journals (Sweden)

    Ramalingam Subramaniam

    2015-09-01

    Full Text Available Activated carbon, prepared from an agricultural waste, cashew nut shell (CNS was utilized as an adsorbent for the removal of methylene blue (MB dye from aqueous solution. Batch adsorption study was carried out with variables like pH, adsorbent dose, initial dye concentration and time. The response surface methodology (RSM was applied to design the experiments, model the process and optimize the variable. A 24 full factorial central composite design was successfully employed for experimental design and analysis of the results. The parameters pH, adsorbent dose, initial dye concentration, and time considered for this investigation play an important role in the adsorption studies of methylene blue dye removal. The experimental values were in good agreement with the model predicted values. The optimum values of pH, adsorbent dose, initial dye concentration and time are found to be 10, 2.1846 g/L, 50 mg/L and 63 min for complete removal of MB dye respectively.

  16. Comparison of Catalytic Activities for Sonocatalytic, Photocatalytic and Sonophotocatalytic Degradation of Methylene Blue in the Presence of Magnetic Fe3O4/CuO/ZnO Nanocomposites

    Science.gov (United States)

    Taufik, Ardiansyah; Tju, Hendry; Saleh, Rosari

    2016-04-01

    Fe3O4/CuO/ZnO nanocomposites with different molar ratio were synthesized using sol-gel method. The as-synthesized samples were characterized by X-ray diffraction (XRD), UV-visible spectroscopy, BET surface area analyszer, and Electron Spin Resonance (ESR). The sonocatalytic-photocatalytic-sonophotocatalytic activity of as-synthesized samples was investigated based on methylene blue degradation. Moreover, the role of active species was investigated using scavenger technique. The results showed that hole plays an important key role in sono-photo-sonophotocatalytic degradation of methylene blue.

  17. Study of Epigenetic Properties of Poly(HexaMethylene Biguanide Hydrochloride (PHMB

    Directory of Open Access Journals (Sweden)

    Edmond E. Creppy

    2014-08-01

    Full Text Available Poly(HexaMethylene Biguanide hydrochloride (PHMB CAS No. [32289-58-0] is a particularly effective member of the biguanides antiseptic chemical group, and has been in use since the early fifties in numerous applications. It has been proposed that PHMB be classified as a category 3 carcinogen although PHMB is not genotoxic. It has been hypothesized that PHMB may have epigenetic properties effects, including non-genotoxic modifications of DNA bases, DNA methylation and mitogenic cytokine production. These properties have been assessed in vitro using 3 cell types: Caco-2 cells (from a human colon adenocarcinoma with a non-functional p53 gene. (∆p53: mut p53, N2-A (Neuro-2A cells, mouse neural cells, the brain being a possible target organ in rodents and HepG2 cells (human hepatocellular carcinoma with functional p53 gene. From the concentration 1 µg/mL up to 20 µg/mL of PHMB, no effect was observed, either growth stimulation or inhibition. Viability testing using neutral red led to an IC 50 of 20–25 µg/mL after treatment with PHMB for 3 h, whereas the MTT test led to IC50 values of 80 µg/mL, 160 µg/mL and 160 µg/mL respectively for HepG2 cells, Neuro-2A cells and Caco-2 cells. PHMB does not induce significant oxidative stress (production of MDA or lipoperoxidation, nor does it induce hydroxylation of DNA (8-OH-dG and/or its hypermethylation (m5dC, the latter being strongly implicated in DNA replication and regulation and cell division. PHMB does not induce significant production of mitogenic cytokines such as TNF-α (tumor necrosis factor, interleukins (IL-1 alpha, and the transcription factor nuclear factor kappa B (NF-κB which can cause either apoptosis or stimulate the growth of transformed cells or tumors. Instead, from concentrations of 20 to 100 µg/mL, PHMB kills cells of all types in less than 3 h. The expression of genes involved in the mechanisms of cell death induced by PHMB, including p53, the pro apoptotic gene bax and others

  18. Fabrication and Characterization of Tailored TiO2and WO3/MWCNT Composites for Methylene Blue Decomposition%Fabrication and Characterization of Tailored TiO2 and WO3/MWCNT Composites for Methylene Blue Decomposition

    Institute of Scientific and Technical Information of China (English)

    ZHU Lei; MENG Zeda; OH Won-Chun

    2011-01-01

    A sol-gel method was used to prepare WO3/MWCNT-TiO2 composites. Their photocatalytic activities were evaluated by the degradation of methylene blue (MB) solution under UV light. The catalysts were characterized by X-ray diffraction, specific surface area measurement, energy-dispersive X-ray analysis, transmission and scanning electron microscopy. Aqueous MB solutions of 100 ml were photode graded by a small amount of the WO3/MWCNT-TiO2 composite under UV light irradiation. The photocatalytic data showed that the WO3/MWCNT-TiO2 composite achieved a high rate of MB photodegradation. This was attributed to the use of MWCNT which can absorb UV light to create photo-induced electrons, strong adsorption of dye molecules on the photocatalyst, and reduced recombination rate of electron-holes in the WO3/MWCNT-TiO2 composite due to the introduction of the WO3 semiconductor.

  19. SU-E-I-64: Transverse Relaxation Time in Methylene Protons of Non-Alcoholic Fatty Liver Disease Rats

    Energy Technology Data Exchange (ETDEWEB)

    Song, K-H; Lee, D-W; Choe, B-Y [Department of Biomedical Engineering, Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul, Seoul (Korea, Republic of)

    2015-06-15

    Purpose: The aim of this study was to evaluate transverse relaxation time of methylene resonance compared to other lipid resonances. Methods: The examinations were performed using a 3.0 T scanner with a point — resolved spectroscopy (PRESS) sequence. Lipid relaxation time in a lipid phantom filled with canola oil was estimated considering repetition time (TR) as 6000 msec and echo time (TE) as 40 — 550 msec. For in vivo proton magnetic resonance spectroscopy ({sup 1}H — MRS), eight male Sprague — Dawley rats were given free access to a normal - chow (NC) and eight other male Sprague-Dawley rats were given free access to a high — fat (HF) diet. Both groups drank water ad libitum. T{sub 2} measurements in the rats’ livers were conducted at a fixed TR of 6000 msec and TE of 40 – 220 msec. Exponential curve fitting quality was calculated through the coefficients of determination (R{sup 2}). Results: A chemical analysis of phantom and liver was not performed but a T{sub 2} decay curve was acquired. The T{sub 2} relaxation time of methylene resonance was estimated as follows: NC rats, 37.07 ± 4.32 msec; HF rats, 31.43 ± 1.81 msec (p < 0.05). The extrapolated M0 values were higher in HF rats than in NC rats (p < 0.005). Conclusion: This study of {sup 1}H-MRS led to sufficient spectral resolution and signal — to — noise ratio differences to characterize all observable resonances for yielding T{sub 2} relaxation times of methylene resonance. {sup 1}H — MRS relaxation times may be useful for quantitative characterization of various liver diseases, including fatty liver disease. This study was supported by grant (2012-007883 and 2014R1A2A1A10050270) from the Mid-career Researcher Program through the NRF funded by Ministry of Science. In addition, this study was supported by the Industrial R&D of MOTIE/KEIT (10048997, Development of the core technology for integrated therapy devices based on real-time MRI-guided tumor tracking)

  20. Suitability of the methylene blue test for determination of cation exchange capacity of clay minerals related to ammonium acetate method

    Science.gov (United States)

    Milošević, Maja; Logar, Mihovil; Dojčinović, Biljana; Erić, Suzana

    2015-04-01

    Cation exchange capacity (CEC) represents one of the most important parameters of clay minerals which reflects their ability to exchange cations with liquid phases in near contact. Measurement of CEC is used for characterizing sample plasticity, adsorbing and swelling properties which later define their usage in industrial purposes. Several methods have been developed over the years for determination of layer charge, charge density, charge distribution, etc. and have been published in numerous papers (Czimerova et al., 2006; Yukselen and Kaya, 2008). The main goal of present study is comparison of suitability of more recent method - methylene blue test in regard to older method - ammonium acetate for determination of CEC. For this study, we selected one montmorillonite clay (Bogovina, Serbia) and two mainly kaolinite clays (Miličinica, Serbia). Chemicals used for CEC determinations were solution of methylene blue (MB)(14*10-6M/ml) and ammonium acetate (AA) solution (1M). The obtained results are showing generally lower values in case of MB method. The main difference is due to molecular aggregation of MB on the clay surface. AA method is highly sensitive to the presence of CaO. Release of Ca ion from the sample into the solution can limit the saturation of exchange sites by the ammonium ion. This is clearly visible in case of montmorillonite clay. Fe2+ and Mg ions are difficult to move by the ammonium ion because of their ion radius, but in case of MB molecule there is no such restriction in removing them from the exchange sites. MB solution, even in a low concentration (2*10-6M/ml), is showing preferable results in moving the ions from their positions which is already visible after adding a small quantity of solution (25cm3). Both MB-titration and MB-spot test yield similar results and are much simpler methods than AA and they also give other information such as specific surface area (external and internal) whereas AA method only provides information about

  1. Methylene blue injection in treatment of postoperative pain of anal fissure%亚甲蓝注射治疗肛裂术后疼痛体会

    Institute of Scientific and Technical Information of China (English)

    谷凯

    2013-01-01

    目的:观察亚甲蓝注射肛裂术后止痛的疗效。方法:将60例肛裂术后患者随机分为治疗组和对照组,治疗组术后用亚甲蓝稀释液注射,对照组不用亚甲蓝。结果:治疗组效果优于对照组(p<0.05)。结论:亚甲蓝可有效降低肛裂术后的疼痛,值得临床推广。%Objective:To observe the methylene blue injection the anal fissure postoperative analgesic efficacy .Methods:60 cases of a-nal fissure patients were randomly divided into treatment group and control group , treatment group after using methylene blue dilution liq-uid injection , control group without methylene blue .Results:Methylene blue could effectively reduce postoperative pain of anal fissure ( P<0.05 ) , worthy of clinical application .

  2. Thermally induced electrocyclic reaction of methylenecyclopropane methylene diketone derivatives: a facile method for the synthesis of spiro[2.5]octa-3,5-dienes.

    Science.gov (United States)

    Tang, Xiang-Ying; Wei, Yin; Shi, Min

    2010-11-19

    Thermally induced electrocyclic reactions of methylenecyclopropane (MCP) methylene diketone derivatives afford a novel method for the synthesis of spiro[2.5]octa-3,5-dienes in moderate to good yields. Applying this methodology in a one-pot manner for the reactions of MCP aldehydes with 1,3-diketones, catalyzed by l-proline, also afforded the corresponding spiro derivatives.

  3. Efficacy and safety of triple combination therapy with artesunate-amodiaquine-methylene blue for falciparum malaria in children: a randomized controlled trial in burkina faso

    NARCIS (Netherlands)

    Coulibaly, B.; Pritsch, M.; Bountogo, M.; Meissner, P.E.; Nebie, E.; Klose, C.; Kieser, M.; Berens-Riha, N.; Wieser, A.; Sirima, S.B.; Breitkreutz, J.; Schirmer, R.H.; Sie, A.; Mockenhaupt, F.P.; Drakeley, C.; Bousema, T.; Muller, O.

    2015-01-01

    BACKGROUND: Methylene blue (MB) has been shown to be safe and effective against falciparum malaria in Africa and to have pronounced gametocytocidal properties. METHODS: Three days of treatment with artesunate (AS)-amodiaquine (AQ) combined with MB was compared with AS-AQ treatment in a randomized co

  4. Wiring of Glucose Oxidizing Flavin Adenine Dinucleotide-Dependent Enzymes by Methylene Blue-Modified Third Generation Poly(amidoamine) Dendrimers Attached to Spectroscopic Graphite Electrodes

    DEFF Research Database (Denmark)

    Castaing, Victor; Álvarez-Martos, Isabel; Ferapontova, Elena

    2016-01-01

    ordered multiple redox centers, represent an advanced alternative to the existing approaches. Here we show that methylene blue (MB)-labeled G3 PAMAM dendrimers covalently attached to the high-surface area spectroscopic graphite (Gr) electrodes form stable and spatially resolved electronic wires...

  5. Photocatalytic degradation of methylene blue and inactivation of gram-negative bacteria by TiO2 nanoparticles in aqueous suspension

    Science.gov (United States)

    The photocatalytic degradation of methylene blue (MB) and inactivation of Gram-negative bacteria E. coli K12 and P. aeruginosa by TiO2 nanoparticles in aqueous suspension were studied. TiO2 resulted in significant reduction in MB absorption and a shift of MB absorption peak from 664 nm to 658 nm aft...

  6. Comment on "Conformational analysis of small organic molecules using NOE and RDC data: A discussion of strychnine and α-methylene-γ-butyrolactone"

    Science.gov (United States)

    Khodov, I. A.; Kiselev, M. G.; Efimov, S. V.; Klochkov, V. V.

    2016-05-01

    In a recent paper published in this journal, Kolmer et al. [1] reported an experimental approach for conformational analysis of small organic molecules using NOE and RDC techniques. The authors obtained information on conformation of strychnine and α-methylene-γ-butyrolactone molecules. In addition, possible sources of error in the measurement and analysis process and ideas of how to exclude them were discussed.

  7. Electrochemical determination of sulphide at multi-walled carbon nanotubes-dihexadecyl hydrogen phosphate composite film modified electrodes based on in situ synthesis of methylene blue

    Institute of Scientific and Technical Information of China (English)

    An Min Xiang; Li Zhou; Cheng Guo Hu; Sheng Shui Hu

    2008-01-01

    A novel electrochemical method for the determination of sulphide at a multi-walled carbon nanotube-dihexadecyl hydrogenphosphate composite film coated glassy carbon electrode (MWNTs-DHP/GCE) based on in situ synthesis of methylene blue (MB)was established.

  8. Efficacy of C-11 L-methionine positron emission tomography and intraoperative methylene blue staining for localization of parathyroid glands in primary hyperparathyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Hiromasa; Takahashi, Masato; Taguchi, Kazunori; Takada, Naoyuki; Nakada, Kunihiro; Sasaki, Fumiaki; Todo, Satoru [Hokkaido Univ., Sapporo (Japan). School of Medicine

    2002-12-01

    For localization of parathyroid glands in primary hyperparathyroidism we carried out C-11 L-methionine positron emission tomography (Met-PET) in 10 patients (one with hyperplasia and 9 with adenoma) and intraoperative methylene blue staining in 20 patients (one with hyperplasia and 19 with adenoma) and compared the predictive value with that of US and {sup 99m}Tc-sestamibi scintigraphy (MIBI). Methylene blue was administrated at a calculated dose of 5 mg/kg body weight intravenously for 1 h before surgery. The accuracy of identification of pathological parathyroid glands with Met-PET, US and MIBI was 90%, 80% and 70% respectively. Met-PET was more sensitive than US and MIBI and could identify smaller parathyroid glands, particularly in cases with lower serum calcium levels. Met-PET imaging was not affected even in 2 reoperative cases. Intraoperative methylene blue staining of parathyroid glands was successful in 19 patients without major side effects. Met-PET was the most effective method for preoperative imaging of parathyroid glands. Intraoperative methylene blue staining was a safe and effective method and able to facilitate dissection of pathological glands during surgery. (author)

  9. Photocatalytic activity and photocorrosion of atomic layer deposited ZnO ultrathin films for the degradation of methylene blue.

    Science.gov (United States)

    Cao, Yan-Qiang; Chen, Jun; Zhou, Hang; Zhu, Lin; Li, Xin; Cao, Zheng-Yi; Wu, Di; Li, Ai-Dong

    2015-01-16

    ZnO ultrathin films with varied thicknesses of 7-70 nm were prepared at 200 °C on Si and fused quartz substrates by atomic layer deposition (ALD). The impact of film thickness and annealing temperature on the crystallinity, morphology, optical bandgap, and photocatalytic properties of ZnO in the degradation of methylene blue (MB) dye under UV light irradiation (λ = 365 nm) has been investigated deeply. The as-deposited 28 nm thick ZnO ultrathin film exhibits highest photocatalytic activity, ascribed to the smallest band gap of 3.21 eV and proper thickness. The photocorrosion effect of ALD ZnO ultrathin films during photocatalytic process is observed. The presence of MB significantly accelerates the dissolution of ZnO ultrathin films. The possible photoetching mechanism of ZnO in MB solution is proposed.

  10. TiO2/polyaniline composites: An efficient photocatalyst for the degradation of methylene blue under natural light

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Polyaniline (PAn) sensitized nanocrystalline TiO2 composites (TiO2/PAn) were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue (MB). The results showed that PAn was able to sensitize TiO2 efficiently and the composite photocatalyst could be activated by absorbing both the ultraviolet and visible light (λ: 190 ~ 800 nm), whereas pure TiO2 absorbed ultraviolet light only (λ < 380 nm). Under the irradiation of natural light, MB could be degraded more efficiently on the TiO2/PAn composites than on the TiO2. Furthermore, it could be easily separated from the solution by simple sedimentation.

  11. Nanoscale zero-valent iron incorporated with nanomagnetic diatomite for catalytic degradation of methylene blue in heterogeneous Fenton system.

    Science.gov (United States)

    Zha, Yiming; Zhou, Ziqing; He, Haibo; Wang, Tianlin; Luo, Liqiang

    2016-01-01

    Nanoscale zero-valent iron (nZVI) incorporated with nanomagnetic diatomite (DE) composite material was prepared for catalytic degradation of methylene blue (MB) in heterogeneous Fenton system. The material was constructed by two facile steps: Fe3O4 magnetic nanoparticles were supported on DE by chemical co-precipitation method, after which nZVI was incorporated into magnetic DE by liquid-phase chemical reduction strategy. The as-prepared catalyst was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, magnetic properties measurement and nitrogen adsorption-desorption isotherm measurement. The novel nZVI@Fe3O4-diatomite nanocomposites showed a distinct catalytic activity and a desirable effect for degradation of MB. MB could be completely decolorized within 8 min and the removal efficiency of total organic carbon could reach to 90% after reaction for 1 h.

  12. Study on the Effect of the Three-Dimensional Electrode in Degradation of Methylene Blue by Lithium Modified Rectorite

    Directory of Open Access Journals (Sweden)

    Jian Huang

    2016-01-01

    Full Text Available This study presents the electrochemical degradation of methylene blue (MB wastewater in a synthetic solution using three-dimensional particle electrodes. The novel particle electrodes were fabricated in this work using the lithium modified rectorite (Li-REC. The adsorption property of the fabricated particle electrodes was studied in a series of experiments. The optimum electrochemical operating conditions of plate distance, cell voltage, and concentration of electrolyte were 2 cm, 9 V, and 0.06 mol L−1, respectively. It was also found that microwave irradiation can effectively improve the adsorption property and electrical property of the fabricated electrodes. In addition, the scanning electron microscope (SEM of the fabricated electrodes was investigated. The experimental results revealed the order of adsorption property and electrical property of the fabricated electrodes. So, fabricated electrodes are not only of low cost and mass produced, but also efficient to achieve decolorization of MB solution.

  13. Visible light photo-degradation of methylene blue over Fe or Cu promoted ZnO nanoparticles.

    Science.gov (United States)

    Mardani, Hamid Reza; Forouzani, Mehdi; Ziari, Mitra; Biparva, Pourya

    2015-04-15

    CuxZn(1-x)O, FexZn(1-x)O (x=0.01) and ZnO nanoparticles were and were characterized by X-ray diffraction, ultraviolet and visible spectroscopy, FTIR spectroscopy and SEM. The photodegradation of an aqueous solution of methylene blue (as an organic pollutant) by nanoparticles with H2O2 (30%) under visible light and the progress of the reaction were monitored by UV-Vis spectroscopy absorption. The photocatalytic oxidation efficiency of all nanoparticles was 100% at the appropriate time. The degradation time was 90 min for FeZnO, 120 min for CuZnO and 210 min for ZnO. This indicates that the photocatalytic activity of the doped nanoparticles was better than that of ZnO alone. ZnO doped with a small amount of Fe or Cu decreased the size of the nanoparticles and the band gap and increased photocatalytic efficiency.

  14. Synthesis, Characterization and Application of Cobalt Incorporated Mesoporous KIT-6 for the Visible Light Assisted Degradation of Methylene Blue.

    Science.gov (United States)

    Sanjini, N S; Winston, B; Velmathi, S

    2015-09-01

    Highly ordered mesoporous three dimensional la3d cobalt doped KIT-6 (Co-KIT-6) material was synthesized by the simple impregnation method and characterized by various physicochemical techniques such as X-ray diffraction, N2 adsorption-desorption isotherm, diffuse reflectance spectroscopy, Fourier transform infra-red spectroscopy and scanning electron microscopy. Larger pore diameter tuned with a narrow size distribution was observed for prepared Co-KIT-6. A series of Co-KIT-6 with different weight percentages solutions were prepared and the photocatalytic efficacy of the samples for degradation of methylene blue was studied under UV and visible light using UV-visible spectrophotometer. It was found that the catalytic activity depends on the amount of cobalt incorporated into the material. The complete degradation of dye was observed within 50 min. Different amount of catalyst and reaction time was considered for the optimization studies.

  15. Study on the Effect of the Three-Dimensional Electrode in Degradation of Methylene Blue by Lithium Modified Rectorite.

    Science.gov (United States)

    Huang, Jian; Ming, Yin'an; Du, Ying; Wang, Yingru; Wang, Ci'en

    2016-01-01

    This study presents the electrochemical degradation of methylene blue (MB) wastewater in a synthetic solution using three-dimensional particle electrodes. The novel particle electrodes were fabricated in this work using the lithium modified rectorite (Li-REC). The adsorption property of the fabricated particle electrodes was studied in a series of experiments. The optimum electrochemical operating conditions of plate distance, cell voltage, and concentration of electrolyte were 2 cm, 9 V, and 0.06 mol L(-1), respectively. It was also found that microwave irradiation can effectively improve the adsorption property and electrical property of the fabricated electrodes. In addition, the scanning electron microscope (SEM) of the fabricated electrodes was investigated. The experimental results revealed the order of adsorption property and electrical property of the fabricated electrodes. So, fabricated electrodes are not only of low cost and mass produced, but also efficient to achieve decolorization of MB solution.

  16. Efficient degradation of methylene blue dye over tungsten trioxide/multi-walled carbon nanotube system as a novel photocatalyst

    Science.gov (United States)

    Dinari, Mohammad; Momeni, Mohamad Mohsen; Ahangarpour, Marzieh

    2016-10-01

    Combination of acid-functionalized multi-walled carbon nanotube/tungsten trioxide (MWCNT/WO3) with different MWCNT's weight percentages as visible light-induced photocatalysts for photodegradation of methylene blue (MB) dye was synthesized. These photocatalysts were characterized by Fourier transform infrared, X-ray diffraction, UV-Vis diffuse reflectance spectroscopy, field emission scanning electron microscopy and transmission electron microscopy techniques. Their photocatalytic activities were tested by using MB as a model compound. The results show that the MWCNT/WO3 hybrid nanostructures exhibit higher photocatalytic activity than pure WO3 or MWCNTs due to their higher absorption enhancement in visible light region and effective separation of electrons and holes. The stability of the hybrid was characterized through cyclic photocatalytic test.

  17. Synthesis of Carbon Nanomaterials-CdSe Composites and Their Photocatalytic Activity for Degradation of Methylene Blue

    Directory of Open Access Journals (Sweden)

    Ming-Liang Chen

    2012-01-01

    Full Text Available We use multi-walled carbon nanotube (MWCNT and graphene as carbon nanomaterials to obtain carbon nanomaterilas-CdSe composites using a facile hydrothermal method. The intrinsic characteristics of resulting composites were studied by X-ray diffraction (XRD, Scanning electron microscopy (SEM with energy dispersive X-ray (EDX analysis, transmission electron microscopy (TEM and UV-vis diffuse reflectance spectrophotometer. The as-prepared carbon nanomaterilas-CdSe composites possessed great adsorptivity of dyes, extended light absorption range, and efficient charge separation properties simultaneously. Hence, in the photodegradation of methylene blue, a significant enhancement in the reaction rate was observed with carbon nanomaterilas-CdSe composites, compared to the CdSe compound.

  18. Study of the photocatalytic effect of the Ti-doped hydroxyapatite in the degradation of methylene blue solution

    Directory of Open Access Journals (Sweden)

    Anas Salhi

    2015-03-01

    Full Text Available Organic dyes and colouring textile agents are persistent pollutant materials that are difficult to decompose by microbiological treatment processes. Their oxidation through photocatalysis is an alternative way to prevent contamination of the environment. In this work, calcium deficient hydroxyapatite (HAP was synthesized and doped with different amounts of titanium. The performance capability of prepared catalyst to degrade methylene blue dye (MB in aqueous heterogeneous solutions has been demonstrated. The main parameters which govern the photocatalytic treatment efficiency, such as titanium amount in HAP, initial concentration of MB, amount of the catalyst added to solution, UV-irradiation period and bubbling oxygen have been investigated. Photodegradation of  MB is found to be effective with HAP/Ti 11% in oxygenated medium. However, pH has no significant effect on the yield of discoloration. 

  19. Preparation and characterization of double layer thin films ZnO/ZnO:Ag for methylene blue photodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Wibowo, Singgih, E-mail: singgih@st.fisika.undip.ac.id; Sutanto, Heri, E-mail: herisutanto@undip.ac.id [Department of Physics, Faculty of Science and Mathematics, Diponegoro University (Indonesia)

    2016-02-08

    Double layer (DL) thin films of zinc oxide and silver-doped zinc oxide (ZnO/ZnO:Ag) were deposited on glass substrate by sol-gel spray coating technique. The prepared thin films were subjected for optical and photocatalytic studies. UV-visible transmission spectra shows that the subtitution of Ag in ZnO leads to band gap reduction. The influence of Ag doping on the photocatalytic activity of ZnO for the degradation of methylene blue dye was studied under solar radiation. The light absorption over an extended visible region by Ag ion doping in ZnO film contributed equally to improve the photocatalytic activity up to 98.29%.

  20. Preparation and characterization of double layer thin films ZnO/ZnO:Ag for methylene blue photodegradation

    Science.gov (United States)

    Wibowo, Singgih; Sutanto, Heri

    2016-02-01

    Double layer (DL) thin films of zinc oxide and silver-doped zinc oxide (ZnO/ZnO:Ag) were deposited on glass substrate by sol-gel spray coating technique. The prepared thin films were subjected for optical and photocatalytic studies. UV-visible transmission spectra shows that the subtitution of Ag in ZnO leads to band gap reduction. The influence of Ag doping on the photocatalytic activity of ZnO for the degradation of methylene blue dye was studied under solar radiation. The light absorption over an extended visible region by Ag ion doping in ZnO film contributed equally to improve the photocatalytic activity up to 98.29%.

  1. Enhanced photocatalytic degradation of methylene blue by ZnO-reduced graphene oxide composite synthesized via microwave-assisted reaction

    Energy Technology Data Exchange (ETDEWEB)

    Lv Tian [Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, Shanghai, 200062 (China); Pan Likun, E-mail: lkpan@phy.ecnu.edu.cn [Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, Shanghai, 200062 (China); Liu Xinjuan; Lu Ting; Zhu Guang; Sun Zhuo [Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, Shanghai, 200062 (China)

    2011-10-13

    Highlights: > ZnO-reduced graphene oxide composite is synthesized via microwave assisted reaction. > The method allows a facile, safe and rapid reaction in aqueous media. > A high dye degradation efficiency is achieved under UV light irradiation. - Abstract: A quick and facile microwave-assisted reaction is used to synthesize ZnO-reduced graphene oxide (RGO) hybrid composites by reducing graphite oxide dispersion with zinc nitrate using a microwave synthesis system. Their photocatalytic performance in degradation of methylene blue is investigated and the results show that the RGO plays an important role in the enhancement of photocatalytic performance and the ZnO-RGO composite with 1.1 wt. % RGO achieves a maximum degradation efficiency of 88% in a neutral solution under UV light irradiation for 260 min as compared with pure ZnO (68%) due to the increased light absorption, the reduced charge recombination with the introduction of RGO.

  2. Research on the Purification Technologies for Methylene Bisthiocyanate%溴硝醇提纯技术的研究

    Institute of Scientific and Technical Information of China (English)

    王孝; 朱春来; 王鹤童

    2013-01-01

    The crude product of methylene bisthiocyanate, which is synthesized by chloride, is purified with the methods of recrystalization, extraction and silica gel column chromatography etc. It is proved that the purity of the crude product is improved from 80% to 97. 8% using the purification method.%文章针对氯化溴法合成溴硝醇过程中得到的粗品,提出采用重结晶、萃取、硅胶柱色谱等方法对产品进行提纯.研究证明,经过提纯后,产品纯度由80%提高到97.8%.

  3. Orientation and Optical Polarized Spectra (380–900 nm of Methylene Blue Crystals on a Glass Surface

    Directory of Open Access Journals (Sweden)

    Maja D. Milošević

    2013-01-01

    Full Text Available The crystallographic directions of the crystal toward the vector of polarized light can accurately be positioned, so the information that we gain from polarized spectra can be consistently interpreted according to known crystal structure. The orientation and optical properties of the methylene blue (MB crystals were analyzed by XRD, XRPD, and polarized VIS-NIR spectroscopy. Cationic dye, MB, was polymerized into crystals on a glass slate. The blue color crystals showed pronounced dichroism, twin lamellar structure and bladed to fibrous habit. According to XRD data, [010] direction lies perpendicular to the crystal surface, so we recognized it as (0k0 face, while [100] and [001] directions coincide with crystal elongation and crystal thickness respectively. In this paper, the polarized spectra of MB crystal are presented, measured with the aim of acquisition of referent values, which could be helpful for the identification of MB molecular aggregation.

  4. Photocatalytic degradation of methylene blue in TiO2 aqueous suspensions using microwave powered electrodeless discharge lamps.

    Science.gov (United States)

    Hong, Jun; Sun, Cheng; Yang, Shao-Gui; Liu, Ya-Zi

    2006-05-20

    Photocatalytic degradation of methylene blue (MB) in TiO(2) aqueous suspensions using microwave (MW) powered electrodeless discharge lamps (EDLs) was studied. MB of initial concentration 100 mg/l was mainly decomposed in the process of photocatalytic degradation using EDLs (PCD/EDLs) after 15 min of irradiation. The corresponding mineralization efficiency was 45%. The influence of factors as EDLs, solution volume and TiO(2) catalyst dosage on the decomposition of MB in the PCD/EDLs process was also investigated. The optimal decomposition efficiency was observed when EDLs-4 (four 10 mm x 50 mm EDLs), solution volume of 50 ml and TiO(2) catalyst dosage of 1-4 g/l were used in the study. The PCD/EDLs process was promising in treating MB polluted water.

  5. Efficient degradation of methylene blue dye over tungsten trioxide/multi-walled carbon nanotube system as a novel photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Dinari, Mohammad; Momeni, Mohamad Mohsen; Ahangarpour, Marzieh [Isfahan University of Technology, Department of Chemistry, Isfahan (Iran, Islamic Republic of)

    2016-10-15

    Combination of acid-functionalized multi-walled carbon nanotube/tungsten trioxide (MWCNT/WO{sub 3}) with different MWCNT's weight percentages as visible light-induced photocatalysts for photodegradation of methylene blue (MB) dye was synthesized. These photocatalysts were characterized by Fourier transform infrared, X-ray diffraction, UV-Vis diffuse reflectance spectroscopy, field emission scanning electron microscopy and transmission electron microscopy techniques. Their photocatalytic activities were tested by using MB as a model compound. The results show that the MWCNT/WO{sub 3} hybrid nanostructures exhibit higher photocatalytic activity than pure WO{sub 3} or MWCNTs due to their higher absorption enhancement in visible light region and effective separation of electrons and holes. The stability of the hybrid was characterized through cyclic photocatalytic test. (orig.)

  6. Photophysical and Photoelectric Properties of 2—{[4—(N—Hexadecyl—N—methylamino)phenyl]methylene}—propanedinitrile

    Institute of Scientific and Technical Information of China (English)

    刘迪; 吴魁旺; 王雪松; 侯原军; 张宝文; 曹怡

    2003-01-01

    2-{[4-(N-Hexadecyl-N-methylamino)phenyl]methylene}-propanedinitrile(HMAPN) with typical donor-π-acceptor(D-π-A)structure was synthesized.It could be easily assembled into stable films by LB technique.The photophysical properties of HMAPN were investigated in solution and on LB films.The photoelectric properties of HMAPN were examined and the anodic photocurrent of the ITO electrode modified by the monolayer LB film of HMAPN was measured as 835 nA/cm2 under the white light of 218.2 mW/cm2 without bias voltage.The effects of light intensity,bias voltage on the photocurrent were discussed.The possible mechanism of the photocurrent formation was given.

  7. Reduction of matrix effects in polystyrene/poly(methylene methacrylate) blends by metal-assisted secondary ion mass spectrometry.

    Science.gov (United States)

    Becker, Nora; Wirtz, Tom

    2012-07-17

    Secondary ion mass spectrometry (SIMS) is a very surface sensitive analysis technique with low detection limits. The main drawback of SIMS is its inherent incapability of providing quantitative information about sample compositions due to the frequent occurrence of ionization- and sputter-induced matrix effects. Metal-assisted SIMS (MetA-SIMS) is an experimental approach that consists in covering an organic sample with a minute amount of a noble metal prior to a static SIMS analysis, the main objective being an increase of the characteristic secondary ion intensities. We show in this article that MetA-SIMS is also a simple and efficient tool for reducing matrix effects in a set of polymer blend samples containing different relative concentrations polystyrene (PS) and poly(methylene methacrylate) (PMMA). These findings can be explained by diffusion processes leading to a sample surface configuration consisting of individual polymer chains embedded in a common Ag matrix.

  8. Photocatalytic degradation of methylene blue on magnetically separable MgFe2O4 under visible light irradiation

    KAUST Repository

    Shahid, Muhammad

    2013-05-01

    A magnetically separable single-phase MgFe2O4 photocatalyst with a spinel crystal structure was synthesized by using the solid-state reaction method. The formation of spinel structure is confirmed by X-ray diffraction and Fourier transform infrared spectroscopy. The magnetic measurements showed that the photocatalyst material can be separated from water when an external magnetic field is added and redispersed into water solution after the external magnetic field is eliminated. It is one of the promising photocatalysts for waste water treatment. The photocatalytic activity of MgFe2O4 was investigated by using the photo-decomposition of methylene blue dye under visible light. The photoelectrochemical property of the MgFe2O4 was studied by measuring their photocurrent-potential behavior in 1 M NaOH electrolyte under AM 1.5100 mW cm-2 illumination. © 2013 Elsevier B.V. All rights reserved.

  9. Joint interaction of ethidium bromide and methylene blue with DNA. The effect of ionic strength on binding thermodynamic parameters.

    Science.gov (United States)

    Vardevanyan, Poghos O; Antonyan, Ara P; Parsadanyan, Marine A; Torosyan, Margarita A; Karapetian, Armen T

    2016-07-01

    Large amount of data of experimental and theoretical studies have shown that ethidium bromide (EtBr) and methylene blue (MB) may bind to nucleic acids via three modes: intercalation between two adjacent base pairs, insertion into the plane between neighboring bases in the same strand (semi-intercalation), and outside binding with negatively charged backbone phosphate groups. The aim of the given research is to examine the behavior of these two ligands at both separate and joint DNA binding. The obtained experimental data show that the effect of simultaneous binding of EtBr and MB on double-stranded DNA has a non-additive effect of separate binding. The analyses of the melting thermodynamic parameters of DNA complexes with two bound ligands suggest competitive mechanism of interaction.

  10. [Antioxidant activities of green and black teas determined by the cumene hydroperoxide/hemoglobin.methylene blue method].

    Science.gov (United States)

    Sugita, Osamu; Ishizawa, Nobuhito; Nakano, Masaharu; Matsuto, Takayuki; Okada, Masahiko

    2003-09-01

    Antioxidant activity in tea was measured by the new cumene hydroperoxide/hemoglobin.methylene blue(CHP/Hb.MB) method developed in our laboratory. Using the CHP/Hb.MB method, we investigated the activities of polyphenols(11 varieties) in order to determine their reactivity on CHP. According to the CHP/Hb.MB method, an increase in the number of hydroxyl groups in polyphenols induced high antioxidant activity. We found that this method was capable of measuring the antioxidant activity of polyphenols. Consequently, we were able to measure the antioxidant activities of heated, green, powdered and black teas by this method. The average of antioxidant activities of heated green tea was 207 nmol/ml, while that of green tea was 280 nmol/ml, powdered green tea was 481 nmol/ml and black tea was 215 nmol/ml respectively.

  11. Differential photodynamic response of cultured cells to methylene blue and toluidine blue: role of dark redox processes.

    Science.gov (United States)

    Blázquez-Castro, Alfonso; Stockert, Juan C; Sanz-Rodríguez, Francisco; Zamarrón, Alicia; Juarranz, Angeles

    2009-03-01

    Cultured cells treated with equal concentrations of thiazine photosensitizers methylene blue (MB) or toluidine blue (TB) showed a distinct photodynamic lethality, with TB being much more effective, when exposed to red light from a LED source. This effect is accounted for because of the differences in the chemical reduction of MB and TB in the intracellular environment. While TB accumulates as blue granular structures, MB does not give such a localization pattern. However, upon exposure of MB-treated cells to oxidant agents, the dye becomes clearly localized in the cytoplasm as blue granules. We propose that massive reduction of MB to its leuco form inside the cell inhibits most of the photodynamic damage, while no such reduction occurs with TB.

  12. Determination of methylene blue biosorption by Rhizopus arrhizus in the presence of surfactants with different chemical structures.

    Science.gov (United States)

    Karatay, Sevgi Ertuğrul; Gül, Ulküye Dudu; Dönmez, Gönül

    2014-10-03

    Methylene blue (MB) biosorption properties of Rhizopus arrhizus were investigated in the presence of surfactants. The effects of cationic and anionic surfactants on MB removal by dead biomass (1 g L(-1)) were determined. MB removal was tested as a function of initial pH (2-12), contact time (5-1440 min), and dye (37.4-944.7 mg L(-1)) and surfactant (0-10 mM) concentrations. The opposite charged anionic surfactant dodecylbenzenesulfonic acid sodium salt (DBS) enhanced sorption of cationic MB by biomass dramatically. Maximum biosorption capacity was 471.5 mg g(-1) at pH 8 with 0.5 mM DBS at 944.7 mg L(-1) MB concentration. The surfactant-stimulated fungal decolorization method may provide a highly efficient, inexpensive, and time-saving procedure in biological wastewater treatment technologies.

  13. Plasmon-assisted degradation of methylene blue with Ag/AgCl/montmorillonite nanocomposite under visible light.

    Science.gov (United States)

    Sohrabnezhad, Sh; Zanjanchi, M A; Razavi, M

    2014-09-15

    Metal-semiconductor compounds, such as Ag/AgX (X=Cl, Br, I), enable visible light absorption and separation of photogenerated electron-hole through surface plasmon resonance (SPR) effect. However, the electron-hole generated and separated by light are vulnerable in Ag/AgX phase because of the occurrence of secondary recombined. In order to more effectively utilize the SPR photocatalytic effect, nanoparticles are located in a matrix. In this article, Ag/AgCl nanoparticles were synthesized in montmorillonite (MMT) matrix using dispersion method and light irradiation. The structure, composition and optical properties of such material were investigated by transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), X-ray diffraction (XRD) and FTIR. Powder X-ray diffraction showed intercalation of Ag/AgCl nanoparticles into the clay layers. The as-prepared plasmonic photocatalyst exhibited an enhanced and stable photoactivity for the degradation of methylene blue (MB) under visible light. The high activity was attributed to the surface plasmon resonance (SPR) exhibited by Ag nanoparticles on the surface of AgCl. The detection of reactive species by radical scavengers displays that O2- and OH- are the main reactive species for the degradation of MB under visible light irradiation. The studies showed that 20 min illumination under visible light can complete degradation of methylene blue (MB), and indicate a high stability of photocatalytic degradation. The mechanism of separation of the photo-generated electrons and holes at the Ag/AgCl-MMT nanocomposite was discussed.

  14. Photocatalytic degradation of methylene blue dye by zinc oxide nanoparticles obtained from precipitation and sol-gel methods.

    Science.gov (United States)

    Balcha, Abebe; Yadav, Om Prakash; Dey, Tania

    2016-12-01

    Zinc oxide (ZnO) nanoparticles were synthesized by precipitation and sol-gel methods. The aim of this study was to understand how different synthetic methods can affect the photocatalytic activity of ZnO nanoparticles. As-synthesized ZnO nanoparticles were characterized by X-ray diffraction (XRD) and UV-Visible spectroscopic techniques. XRD patterns of ZnO powders synthesized by precipitation and sol-gel methods revealed their hexagonal wurtzite structure with crystallite sizes of 30 and 28 nm, respectively. Their photocatalytic activities were evaluated by photocatalytic degradation of methylene blue, a common water pollutant, under UV radiation. The effects of operational parameters such as photocatalyst load and initial concentration of the dye on photocatalytic degradation of methylene blue were investigated. While the degradation of dye decreased over the studied dye concentration range of 20 to 100 mg/L, an optimum photocatalyst load of 250 mg/L was needed to achieve dye degradation as high as 81 and 92.5 % for ZnO prepared by precipitation and sol-gel methods, respectively. Assuming pseudo first-order reaction kinetics, this corresponded to rate constants of 8.4 × 10(-3) and 12.4 × 10(-3) min(-1), respectively. Hence, sol-gel method is preferred over precipitation method in order to achieve higher photocatalytic activity of ZnO nanostructures. Photocatalytic activity is further augmented by better choice of capping ligand for colloidal stabilization, starch being more effective than polyethylene glycol (PEG).

  15. Azure B, a metabolite of methylene blue, is a high-potency, reversible inhibitor of monoamine oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Petzer, Anél, E-mail: 12264954@nwu.ac.za [Unit for Drug Research and Development, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom, 2520 (South Africa); Harvey, Brian H. [Division of Pharmacology, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom, 2520 (South Africa); Wegener, Gregers [Centre for Psychiatric Research, Aarhus University Hospital-Risskov, Skovagervej 2, 8240 Risskov (Denmark); Petzer, Jacobus P. [Division of Pharmaceutical Chemistry, School of Pharmacy, North-West University, Private Bag X6001, Potchefstroom, 2520 (South Africa)

    2012-02-01

    Methylene blue (MB) has been shown to act at multiple cellular and molecular targets and as a result possesses diverse medical applications. Among these is a high potency reversible inhibition of monoamine oxidase A (MAO-A) that may, at least in part, underlie its adverse effects but also its psycho- and neuromodulatory actions. MB is metabolized to yield N-demethylated products of which azure B, the monodemethyl species, is the major metabolite. Similar to MB, azure B also displays a variety of biological activities and may therefore contribute to the pharmacological profile of MB. Based on these observations, the present study examines the interactions of azure B with recombinant human MAO-A and -B. The results show that azure B is a potent MAO-A inhibitor (IC{sub 50} = 11 nM), approximately 6-fold more potent than is MB (IC{sub 50} = 70 nM) under identical conditions. Measurements of the time-dependency of inhibition suggest that the interaction of azure B with MAO-A is reversible. Azure B also reversibly inhibits the MAO-B isozyme with an IC{sub 50} value of 968 nM. These results suggest that azure B may be a hitherto under recognized contributor to the pharmacology and toxicology of MB by blocking central and peripheral MAO-A activity and as such needs to be considered during its use in humans and animals. Highlights: ► Methylene blue (MB) is a known potent MAO-A inhibitor. ► Azure B, the major metabolite of MB, is more potent as a MAO-A inhibitor. ► Azure B may be a contributor to the CNS pharmacology and toxicology of MB.

  16. Adsorption of methylene blue from aqueous solution by jackfruit (Artocarpus heteropyllus) leaf powder: A fixed-bed column study.

    Science.gov (United States)

    Uddin, Md Tamez; Rukanuzzaman, Md; Khan, Md Maksudur Rahman; Islam, Md Akhtarul

    2009-08-01

    Continuous fixed-bed studies were undertaken to evaluate the efficiency of jackfruit leaf powder (JLP) as an adsorbent for the removal of methylene blue (MB) from aqueous solution under the effect of various process parameters like bed depth (5-10cm), flow rate (30-50mL/min) and initial MB concentrations (100-300mg/L). The pH at point of zero charge (pH(PZC)) of the adsorbent was determined by the titration method and a value of 3.9 was obtained. A FTIR of the adsorbent was done before and after the adsorption to find the potential adsorption sites for interaction with methylene blue molecules. The results showed that the total adsorbed quantities and equilibrium uptake decreased with increasing flow rate and increased with increasing initial MB concentration. The longest breakthrough time and maximum MB adsorption were obtained at pH 10. The results showed that the column performed well at low flow rate. Also, breakthrough time and exhaustion time increased with increasing bed depth. The bed-depth service time (BDST) model and the Thomas model were applied to the adsorption of MB at different bed depths, flow rates, influent concentrations and pH to predict the breakthrough curves and to determine the characteristic parameters of the column that are useful for process design. The two model predictions were in very good agreement with the experimental results at all the process parameters studied indicating that they were very suitable for JLP column design.

  17. Renal effects of Mammea africana Sabine (Guttiferae stem bark methanol/methylene chloride extract on L-NAME hypertensive rats

    Directory of Open Access Journals (Sweden)

    Nguelefack-Mbuyo Elvine

    2010-01-01

    Full Text Available Objective : The present study aims at evaluating the effects of methanol/methylene chloride extract of the stem bark of Mammea africana on the renal function of L-NAME treated rats. Material and Methods : Normotensive male Wistar rats were divided into five groups respectively treated with distilled water, L-NAME (40 mg/kg/day, L-NAME + L-arginine (100 mg/kg/day, L-NAME + captopril (20 mg/kg/day or L-NAME + M. africana extract (200 mg/kg/day for 30 days. Systolic blood pressure was measured before and at the end of treatment. Body weight was measured at the end of each week. Urine was collected 6 and 24 h after the first administration and further on day 15 and 30 of treatment for creatinine, sodium and potassium quantification, while plasma was collected at the end of treatment for the creatinine assay. ANOVA two way followed by Bonferonni or one way followed by Tukey were used for statistical analysis. Results : M. africana successfully prevented the rise in blood pressure and the acute natriuresis and diuresis induced by L-NAME. When given chronically, the extract produced a sustained antinatriuretic effect, a non-significant increase in urine excretion and reduced the glomerular hyperfiltration induced by L-NAME. Conclusions : The above results suggest that the methanol/methylene chloride extract of the stem bark of M. africana may protect kidney against renal dysfunction and further demonstrate that its antihypertensive effect does not depend on a diuretic or natriuretic activity.

  18. Intratumor photosensitizer injection for photodynamic therapy: Pre-clinical experience with methylene blue, Pc 4, and Photofrin

    Science.gov (United States)

    Baran, Timothy M.; Foster, Thomas H.

    2016-03-01

    Intravenous administration of some photosensitizers, including the FDA-approved Photofrin, results in significant systemic photosensitivity and a 2-3-day drug-light interval. Direct intratumor injection of photosensitizer could potentially eliminate these negative aspects of photodynamic therapy (PDT), while requiring a lower photosensitizer dose to achieve comparable drug concentration in the target tissue. We performed PDT using intratumor injection of 3 photosensitizers, methylene blue (MB), Pc 4, and Photofrin, in mouse tumor models. After a 0-15 minute drug-light interval, illumination was delivered by appropriate diode lasers. For animals receiving MB or Pc 4, surface illumination was delivered using a microlens-terminated fiber. For animals receiving Photofrin, interstitial illumination was delivered by a 1 cm diffuser. In animals receiving MB or Pc 4, tumor dimensions were measured daily post-PDT, with a cure being defined as no palpable tumor 90 days post-treatment. For Photofrin, animals were sacrificed 24 hours post-PDT and tumors were excised, with samples HE stained to assess PDT-induced necrosis. 55% of tumors were cured with MB-PDT, and significant tumor growth delay (p=0.002) was observed for Pc 4. For Photofrin PDT, the mean necrosis radius was 3.4+/-0.8 mm, compared to 2.9+/-1.3 mm for systemic administration, which was not a significant difference (p=0.58). Intratumoral injection of the photosensitizers methylene blue, Pc 4, and Photofrin is feasible, and results in appreciable tumor response. Further investigation is necessary to optimize treatment protocols and assess the systemic photosensitivity induced by intratumor injection.

  19. REMOVAL OF METHYLENE BLUE FROM AQUEOUS SOLUTION BY ACTIVATED CARBON PREPARED FROM THE PEEL OF CUCUMIS SATIVA FRUIT BY ADSORPTION

    Directory of Open Access Journals (Sweden)

    Manonmani Subbian

    2010-02-01

    Full Text Available The use of low-cost, locally available, highly efficient, and eco-friendly adsorbents has been investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. This study investigates the potential use of activated carbon prepared from the peel of Cucumis sativa fruit for the removal of methylene blue (MB dye from simulated wastewater. The effects of different system variables, adsorbent dosage, initial dye concentration, pH, and contact time were investigated, and optimal experimental conditions were ascertained. The results showed that as the amount of the adsorbent increased, the percentage of dye removal increased accordingly. The optimum pH for dye adsorption was 6.0. Maximum dye was sequestered within 50 min of the start of each experiment. The adsorption of methylene blue followed the pseudo-second-order rate equation and fit the Langmuir, Freundlich, Dubinin-Radushekevich (D-R, and Tempkin equations well. Maximum removal of MB was obtained at pH 6 as 99.79% for adsorbent doses of 0.6 g/ 50 mL and 25 mg/L initial dye concentrations at room temperature. The maximum adsorption capacity obtained from the Langmuir equation was 46.73 mg g-1. The rate of adsorption was found to conform to pseudo-second-order kinetics with a good correlation (R2 > 0.9677 with intraparticle diffusion as one of the rate-determining steps. Activated carbon developed from the peel of Cucumis sativa fruit can be an attractive option for dye removal from wastewater.

  20. SYNTHESIS, CHARACTERIZATION, THERMAL ANALYSIS, CONDUCTIVITY AND BAND GAPS OF OLIGO {4-[(2-HYDROXYL-1-NAPHTHYL)METHYLENE]-AMINOBENZOIC ACID}

    Institute of Scientific and Technical Information of China (English)

    Ismet Kaya; Ali Bilici

    2009-01-01

    The oxidative polycondensation reaction conditions of 4-[(2-hydroxyl-l-naphthyl)methylene]aminobenzoic acid (4-HNMABA) with H2O2,air O2 and NaOCl were studied in an aqueous alkaline medium between 40℃ and 90℃.The structure of oligo {4-[(2-hydroxyl-1-naphthyl)methylene]aminobenzoic acid} (O-4-HNMABA) was characterized by using 1H-NMR,13C-NMR,FT-IR,UV-Vis,size exclusion chromatography (SEC) and elemental analysis techniques.At the optimum reaction conditions,the yield of O-4-HNMABA was found to be 70% for H2O2 oxidant,94% for air O2 oxidant and 87% for NaOCl oxidant.According to the SEC analysis,the number-average molecular weight (Mn),weight-average molecular weight (Mw) and polydispersity index (PDI) values of O-4-HNMABA were found to be 850,1350 and 1.59,using H2O2,1800,2200 and 1.22,using air O2 and 2200,3000 and 1.36,using NaOCl,respectively.TGA-DTA analyses showed that O-4-HNMABA was more stable than 4-HNMABA.The highest occupied molecular orbital,the lowest unoccupied molecular orbital and electrochemical energy gaps ( Eg) of 4-HNMABA and O-4-HNMABA were found to be -6.34,-6.56; -2.67,-3.04; 3.67 and 3.52 eV,respectively,by cyclic voltammetry (CV).According to UV-Vis measurements,optical band gaps (E,g) of 4-HNMABA and O-4-HNMABA were found to be 3.12 and 3.03 eV,respectively.