Science.gov

Sample records for additional methylene group

  1. Structure-property relationships in addition polyimides. 1: Resins from four-ring aromatic diamines containing carbonyl and methylene groups

    NASA Technical Reports Server (NTRS)

    Delvigs, Peter; Klopotek, David L.; Cavano, Paul J.

    1994-01-01

    In an effort to improve the processing characteristics of addition-type polyimide resins the use of flexibilized four-ring aromatic diamine moieties was investigated. A series of 12 diamines containing carbonyl and methylene, as well as oxo and thio bridging groups, was synthesized. The diamines were polymerized with the dimethyl ester of 3.3', 4.4' - benzophenonetetracarboxylic acid (BTDE), using the monomethyl ester of nadic acid (NE) as an end-cap. The effect of diamine structure on the solubility and rheological properties during cure was determined. This paper also describes the effect of diamine structure and formulated molecular weight on the glass transition temperature and thermo-oxidative stability at elevated temperatures after various post-cure regimes. The results indicate that polyimides from some of the diamines containing methylene connecting groups have potential as matrix resins for long-term applications at temperatures up to 300 C.

  2. Effect of dimethyl sulfoxide addition on ultrasonic degradation of methylene blue

    NASA Astrophysics Data System (ADS)

    Shimakage, Kaho; Kobayashi, Daisuke; Naya, Masakazu; Matsumoto, Hideyuki; Shimada, Yuichiro; Otake, Katsuto; Shono, Atsushi

    2016-07-01

    The ultrasonic degradation of methylene blue was carried out in the absence and presence of dimethyl sulfoxide (DMSO) as a radical scavenger for various frequencies, and the effects of DMSO addition on the degradation rate constant estimated by assuming first-order kinetics were investigated. The degradation reaction rate decreased with DMSO addition, and hydroxyl radicals were observed to play important roles in the degradation of methylene blue. However, the degradation reaction did not stop with DMSO addition, and the degradation rate constant in the presence of DMSO was not affected by ultrasonic frequency.

  3. Effect of Particle Addition on Degradation Rate of Methylene Blue in an Ultrasonic Field

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    Ultrasound has been found to be an attractive advanced technology for the degradation of hazardous organic compounds in water. In addition, the sonochemical reaction is enhanced by particle addition. However, the enhancement mechanism of particle addition has not been investigated well, because ultrasound enhances not only chemical reactions but also mass transfer. In this study, the ultrasonic degradation of methylene blue was carried out, and the effects of the ultrasonic irradiation condition on the degradation rate were investigated. The effect of ultrasonic frequency on the improvement of degradation by particle addition was also investigated. The order of degradation rate with frequency was the same as the tendency of sonochemical efficiency value obtained using KI oxidation dosimetry method (SEKI). The degradation process of methylene blue was intensified by particle addition, and the degradation rate increased with increasing amount of particle addition. The enhancement of degradation rate by particle addition was influenced by both ultrasonic frequency and type or diameter of particles.

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

    PubMed

    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. PMID:25227191

  5. Hydrogen Bond Acceptors and Additional Cationic Charges in Methylene Blue Derivatives: Photophysics and Antimicrobial Efficiency

    PubMed Central

    Felgenträger, Ariane; Maisch, Tim; Dobler, Daniel; Späth, Andreas

    2013-01-01

    Photodynamic inactivation of bacteria (PIB) by efficient singlet oxygen photosensitizers might be a beneficial alternative to antibiotics in the struggle against multiresistant bacteria. Phenothiazinium dyes belong to the most prominent classes of such sensitizers due to their intense absorption in the red-light region (λabs, max ca. 600–680 nm, ε > 50000 L mol−1 cm−1), their low toxicity, and their attachment/penetration abilities. Except simple substituents like alkyl or hydroxyalkyl residues, nearly no modifications of the phenothiaziniums have been pursued at the auxochromic sites. By this, the properties of methylene blue derivatives and their fields of application are limited; it remains unclear if their potential antimicrobial efficacy may be enhanced, also to compete with porphyrins. We prepared a set of six mainly novel methylene blue derivatives with the ability of additional hydrogen bonding and/or additional cationic charges to study the substituents' effect on their activity/toxicity profiles and photophysical properties. Direct detection of singlet oxygen was performed at 1270 nm and the singlet oxygen quantum yields were determined. In suspensions with both, Gram-positive and Gram-negative bacteria, some derivatives were highly active upon illumination to inactivate S. aureus and E. coli up to 7 log10 steps (99.99999%) without inherent toxicities in the nonirradiated state. PMID:23509728

  6. Effect of methylene group insertions on the structural rigidity of Aib containing helices.

    PubMed

    Duley, Anju; Gowda, Vasantha; Ganjiwale, Anjali; Raghothama, Srinivasarao; Ramanathan, Gurunath

    2015-11-01

    Nonprotein amino acids are being extensively used in the design of synthetic peptides to create new structure mimics. In this study we report the effect of methylene group insertions in a heptapeptide Boc-Ala1-Leu2-Aib3-Xxx4-Ala5-Leu6-Aib7-OMe which nicely folds into a mixed 310 -/α-helical structure when Xxx= Ala. Analogs of this peptide have been made and studied by replacing central Xxx4 residue with Glycine (α-residue), β-Alanine (β-Αla), γ-aminobutyric acid (Gaba), and ε-aminocaproic acid (ε-Aca). NMR and circular dichroism were used to study the solution structure of these peptides. Crystals of the peptides containing alanine, β-Αla, and Gaba reveal that increasing the number of central methylene (-CH2 -) groups introduces local perturbations even as the helical structure is retained. PMID:26152771

  7. An Exocyclic Methylene Group Acts As a Bioisostere of the 2′-Oxygen Atom in LNA

    SciTech Connect

    Seth, Punit P.; Allerson, Charles R.; Berdeja, Andres; Siwkowski, Andrew; Pallan, Pradeep S.; Gaus, Hans; Prakash, Thazha P.; Watt, Andrew T.; Egli, Martin; Swayze, Eric E.

    2010-12-07

    We show for the first time that it is possible to obtain LNA-like (Locked Nucleic Acid 1) binding affinity and biological activity with carbocyclic LNA (cLNA) analogs by replacing the 2{prime}-oxygen atom in LNA with an exocyclic methylene group. Synthesis of the methylene-cLNA nucleoside was accomplished by an intramolecular cyclization reaction between a radical at the 2{prime}-position and a propynyl group at the C-4{prime} position. Only methylene-cLNA modified oligonucleotides showed similar thermal stability and mismatch discrimination properties for complementary nucleic acids as LNA. In contrast, the close structurally related methyl-cLNA analogs showed diminished hybridization properties. Analysis of crystal structures of cLNA modified self-complementary DNA decamer duplexes revealed that the methylene group participates in a tight interaction with a 2{prime}-deoxyribose residue of the 5{prime}-terminal G of a neighboring duplex, resulting in the formation of a CH...O type hydrogen bond. This indicates that the methylene group retains a negative polarization at the edge of the minor groove in the absence of a hydrophilic 2{prime}-substituent and provides a rationale for the superior thermal stability of this modification. In animal experiments, methylene-cLNA antisense oligonucleotides (ASOs) showed similar in vivo activity but reduced toxicity as compared to LNA ASOs. Our work highlights the interchangeable role of oxygen and unsaturated moieties in nucleic acid structure and emphasizes greater use of this bioisostere to improve the properties of nucleic acids for therapeutic and diagnostic applications.

  8. Bis(trifluoromethyl)methylene Addition to Vinyl-Terminated SAMs: A Gas-Phase C–C Bond-Forming Reaction on a Surface

    PubMed Central

    2014-01-01

    Vinyl-terminated self-assembled monolayers (SAMs) on silicon oxide substrates were chemically modified by the addition of a bis(trifluoromethyl)methylene group in a rare gas-phase C–C bond-forming reaction to directly generate films carrying terminal CF3 groups. The vinyl-terminated films were treated with hexafluoroacetone azine (HFAA) for modification. The films were characterized with ellipsometry, contact angle measurements, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). In this study, we find that for optimized conditions clean reactions occur on a surface between SAMs with terminal olefins and HFAA, and the product is consistent with bis(trifluoromethyl)cyclopropanation formation after nitrogen extrusion. PMID:24806554

  9. Bis(trifluoromethyl)methylene addition to vinyl-terminated SAMs: a gas-phase C-C bond-forming reaction on a surface.

    PubMed

    Adamkiewicz, Malgorzata; O'Hagan, David; Hähner, Georg

    2014-05-20

    Vinyl-terminated self-assembled monolayers (SAMs) on silicon oxide substrates were chemically modified by the addition of a bis(trifluoromethyl)methylene group in a rare gas-phase C-C bond-forming reaction to directly generate films carrying terminal CF3 groups. The vinyl-terminated films were treated with hexafluoroacetone azine (HFAA) for modification. The films were characterized with ellipsometry, contact angle measurements, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). In this study, we find that for optimized conditions clean reactions occur on a surface between SAMs with terminal olefins and HFAA, and the product is consistent with bis(trifluoromethyl)cyclopropanation formation after nitrogen extrusion. PMID:24806554

  10. Functional interplay between NTP leaving group and base pair recognition during RNA polymerase II nucleotide incorporation revealed by methylene substitution

    PubMed Central

    Hwang, Candy S.; Xu, Liang; Wang, Wei; Ulrich, Sébastien; Zhang, Lu; Chong, Jenny; Shin, Ji Hyun; Huang, Xuhui; Kool, Eric T.; McKenna, Charles E.; Wang, Dong

    2016-01-01

    RNA polymerase II (pol II) utilizes a complex interaction network to select and incorporate correct nucleoside triphosphate (NTP) substrates with high efficiency and fidelity. Our previous ‘synthetic nucleic acid substitution’ strategy has been successfully applied in dissecting the function of nucleic acid moieties in pol II transcription. However, how the triphosphate moiety of substrate influences the rate of P-O bond cleavage and formation during nucleotide incorporation is still unclear. Here, by employing β,γ-bridging atom-‘substituted’ NTPs, we elucidate how the methylene substitution in the pyrophosphate leaving group affects cognate and non-cognate nucleotide incorporation. Intriguingly, the effect of the β,γ-methylene substitution on the non-cognate UTP/dT scaffold (∼3-fold decrease in kpol) is significantly different from that of the cognate ATP/dT scaffold (∼130-fold decrease in kpol). Removal of the wobble hydrogen bonds in U:dT recovers a strong response to methylene substitution of UTP. Our kinetic and modeling studies are consistent with a unique altered transition state for bond formation and cleavage for UTP/dT incorporation compared with ATP/dT incorporation. Collectively, our data reveals the functional interplay between NTP triphosphate moiety and base pair hydrogen bonding recognition during nucleotide incorporation. PMID:27060150

  11. Enhanced methylene blue oxidative removal by copper electrode-based plasma irradiation with the addition of hydrogen peroxide.

    PubMed

    Son, Guntae; Kim, Do-Hyung; Lee, Jung Seok; Lee, Hongshin

    2016-08-01

    Submerged plasma irradiation (SPI)-based advanced oxidation processes have been studied for the oxidation of recalcitrant organic compounds because of their various physical and chemical properties. However, SPI technologies still have a few drawbacks such as relatively low efficiency for wastewater treatment and high energy consumption. In order to overcome these drawbacks, in this study, we proposed the combination of SPI and the Cu(II)-catalyzed Fenton-like system. The removal of methylene blue (MB) by the SPI system was significantly enhanced upon the addition of H2O2. The pseudo-first-order rate constants of MB removal increased with the increase of applied voltage. In addition, the optimum H2O2 dose and initial solution pH were 100 mM and 9, respectively. The reactive oxidants responsible for MB removal in copper electrode-based SPI/H2O2 systems are likely to be hydroxyl radicals (OH) or cupryl ion (Cu(III)), wherein Cu(III) is especially important. Furthermore, the copper electrode-based SPI/H2O2 system is a novel advanced oxidation process capable of oxidizing water recalcitrant and toxic organic pollutants at neutral pH. PMID:27236847

  12. Effectiveness of Phytogenic Feed Additive as Alternative to Bacitracin Methylene Disalicylate on Hematological Parameters, Intestinal Histomorphology and Microbial Population and Production Performance of Japanese Quails

    PubMed Central

    Manafi, M.; Hedayati, M.; Khalaji, S.

    2016-01-01

    This study was conducted to evaluate the effects of phytogenic additive and antibiotic growth promoter in laying Japanese quails. One hundred and sixty five quails were divided into three groups of 5 replicates and 11 quails (8 females and 3 males) in each replicate. Treatment 1 was fed control diet, treatment 2 was fed control diet supplemented with 0.05% bacitracin methylene disalicylate as antibiotic growth promoter and treatment 3 was fed control diet supplemented with 0.1% phytogenic feed additive (PFA) for two periods of 3 weeks each from 37 to 42 weeks of age. Results showed that egg production, eggshell strength, eggshell weight, villus height and villus height to crypt depth ratio were significantly (p≤0.05) increased and feed consumption, feed conversion ratio, albumen, Haugh unit, cholesterol, low-density lipoprotein, alanine transaminase, gamma glutamyltransferase, alkaline phosphatase, high-density lipoprotein, triglyceride, number of goblet cell, crypt depth and intestinal bacterial population of Coliforms, Salmonella and E. coli were significantly (p≤0.05) decreased in PFA fed group. It is concluded that addition of PFA containing phytomolecules and organic acids as main ingredients could significantly improve the production parameters and the general health of laying quails as an alternative to antibiotic growth promoters. PMID:27189636

  13. Effectiveness of Phytogenic Feed Additive as Alternative to Bacitracin Methylene Disalicylate on Hematological Parameters, Intestinal Histomorphology and Microbial Population and Production Performance of Japanese Quails.

    PubMed

    Manafi, M; Hedayati, M; Khalaji, S

    2016-09-01

    This study was conducted to evaluate the effects of phytogenic additive and antibiotic growth promoter in laying Japanese quails. One hundred and sixty five quails were divided into three groups of 5 replicates and 11 quails (8 females and 3 males) in each replicate. Treatment 1 was fed control diet, treatment 2 was fed control diet supplemented with 0.05% bacitracin methylene disalicylate as antibiotic growth promoter and treatment 3 was fed control diet supplemented with 0.1% phytogenic feed additive (PFA) for two periods of 3 weeks each from 37 to 42 weeks of age. Results showed that egg production, eggshell strength, eggshell weight, villus height and villus height to crypt depth ratio were significantly (p≤0.05) increased and feed consumption, feed conversion ratio, albumen, Haugh unit, cholesterol, low-density lipoprotein, alanine transaminase, gamma glutamyltransferase, alkaline phosphatase, high-density lipoprotein, triglyceride, number of goblet cell, crypt depth and intestinal bacterial population of Coliforms, Salmonella and E. coli were significantly (p≤0.05) decreased in PFA fed group. It is concluded that addition of PFA containing phytomolecules and organic acids as main ingredients could significantly improve the production parameters and the general health of laying quails as an alternative to antibiotic growth promoters. PMID:27189636

  14. Methylene-Functionalize Saponite: A New Type of Organoclay with CH(2) Groups Substituting for Bridging Oxygen Centers in the Tetrahedral Sheet.

    PubMed

    Xue, Siqi; Pinnavaia, Thomas J

    2010-03-10

    The synthesis of saponite in the presence of bis(triethoxysilyl)methane (BTESM) as an organosilicon reagent results in the replacement of up to 33.3 % of the oxygen atoms in the tetrahedral sheet by bridging methylene groups. The methylene-functionalized saponites represent a new form of covalently-bonded organoclay that truly is isomorphic with purely inorganic saponite made under equivalent reaction conditions from sodium silicate as the silicon source. The isoelectronic and isolobal relationship between methylene and bridging oxygen centers is essential for methylene saponite formation. Bridging ethylene groups are not incorporated into the Kagome net of the basal surfaces due to a mismatch in bridging group size. The textural properties of the methylene saponites are similar to those for purely inorganic magnesium saponite made under equivalent synthetic conditions in the absence of BTESM. Layer stacking disorders afford large surface areas (~550 to 650 m(2)/g), making the methylene saponites attractive candidates for use as adsorbents and functional fillers for polymer composites. PMID:20508733

  15. Methylene-Functionalize Saponite: A New Type of Organoclay with CH2 Groups Substituting for Bridging Oxygen Centers in the Tetrahedral Sheet

    PubMed Central

    Xue, Siqi; Pinnavaia, Thomas J.

    2010-01-01

    The synthesis of saponite in the presence of bis(triethoxysilyl)methane (BTESM) as an organosilicon reagent results in the replacement of up to 33.3 % of the oxygen atoms in the tetrahedral sheet by bridging methylene groups. The methylene-functionalized saponites represent a new form of covalently-bonded organoclay that truly is isomorphic with purely inorganic saponite made under equivalent reaction conditions from sodium silicate as the silicon source. The isoelectronic and isolobal relationship between methylene and bridging oxygen centers is essential for methylene saponite formation. Bridging ethylene groups are not incorporated into the Kagome net of the basal surfaces due to a mismatch in bridging group size. The textural properties of the methylene saponites are similar to those for purely inorganic magnesium saponite made under equivalent synthetic conditions in the absence of BTESM. Layer stacking disorders afford large surface areas (~550 to 650 m2/g), making the methylene saponites attractive candidates for use as adsorbents and functional fillers for polymer composites. PMID:20508733

  16. Addition polyimide adhesives containing various end groups

    NASA Technical Reports Server (NTRS)

    Saint Clair, A. K.; Saint Clair, T. L.

    1982-01-01

    Addition polyimode oligomers have been synthesized from 3,3 prime, 4,4 prime-benzophenone tetracarboxylic acid dianhydride and 3,3 prime-methylenedianiline using a variety of latent crosslinking groups as end-caps. The nominal 1300 molecular weight imide prepolymers were isolated and characterized for solubility in amide, chlorinated and ether solvents, melt-flow and cure properties, glass transition temperature, and thermal stability on heating in an air atmosphere. Adhesive strengths of the polyimides were obtained both at ambient and elevated temperatures before and after aging at 232 C. Properties of the novel addition polyimides were compared to a known nadic end-capped adhesive, LARC-13.

  17. A Single Methylene Group in Oligoalkylamine-Based Cationic Polymers and Lipids Promotes Enhanced mRNA Delivery.

    PubMed

    Jarzębińska, Anita; Pasewald, Tamara; Lambrecht, Jana; Mykhaylyk, Olga; Kümmerling, Linda; Beck, Philipp; Hasenpusch, Günther; Rudolph, Carsten; Plank, Christian; Dohmen, Christian

    2016-08-01

    The development of chemically modified mRNA holds great promise as a new class of biologic therapeutics. However, the intracellular delivery and endosomal escape of mRNA encapsulated in nanoparticles has not been systematically investigated. Here, we synthesized a diverse set of cationic polymers and lipids from a series of oligoalkylamines and subsequently characterized their mRNA delivery capability. Notably, a structure with an alternating alkyl chain length between amines showed the highest transfection efficiency, which was linked to a high buffering capacity in a narrow range of pH 6.2 to 6.5. Variation in only one methylene group resulted in enhanced mRNA delivery to both the murine liver as well as porcine lungs after systemic or aerosol administration, respectively. These findings reveal a novel fundamental structure-activity relationship for the delivery of mRNA that is independent of the class of mRNA carrier and define a promising new path of exploration in the field of mRNA therapeutics. PMID:27376704

  18. A Methylene Group on C-2 of 24,24-Difluoro-19-nor-1α,25-Dihydroxyvitamin D3 Markedly Increases Bone Calcium Mobilization in vivo

    PubMed Central

    Flores, Agnieszka; Massarelli, Ilaria; Thoden, James B.; Plum, Lori A.; DeLuca, Hector F.

    2015-01-01

    Four side chain fluorinated analogues of 1α,25-dihydroxy-19-norvitamin D have been prepared in convergent syntheses using the Wittig-Horner reaction as a key step. Structures and absolute configurations of analogues 3 and 5 were confirmed by X-ray crystallography. All analogues showed high potency in HL-60 cell differentiation and vitamin D-24-hydroxylase (24-OHase) transcription as compared to 1α,25-dihydroxyvitamin D3 (1). Most important is that all of the 20S-configured derivatives (4 and 6) had high bone mobilizing activity in vivo. However, in the 20R series, a 2-methylene group was required for high bone mobilizing activity. A change in positioning of the 20R molecule in the vitamin D receptor when the 2-methylene group is present may provide new insight into the molecular basis of bone calcium mobilization induced by vitamin D. PMID:26630444

  19. Structural Effects on Arthrobacter Methylene Hydroxylase Activity1

    PubMed Central

    Hayasaka, Steven; Klein, D. A.

    1971-01-01

    Arthrobacter 4-44-2 (ATCC 25581), capable of subterminal oxidation of n-hexadecane to 2-, 3-, and 4-alcoholic and ketonic products, was examined for the ability of this methylene hydroxylase capability to be induced and repressed and for structural relationships influencing methylene function oxidation. Induction was best carried out by use of n-alkanes from 10 to 16 carbons in length and was especially strong with methylcyclohexane among cyclic compounds tested. Induction was not observed with several related alcohols, 1-unsaturated compounds, or methoxy and ethoxy compounds tested. After induction, n-alkanes 14 and 16 carbons in length were transformed to the corresponding internal oxidation products; however, no activity was observed with even-carbon alkanes of shorter chain length. Hexadecene-1 and all alcohols tested, including cyclododecanol, were transformed to corresponding ketonic or aldehydic products. Cyclic compounds tested, including cyclododecane, were not oxidized by induced cells, suggesting that a methyl group plays a role in orientation of the substrate for the methylene hydroxylation but that the methyl function was not as critical after completion of the hydroxylation step regardless of structural configuration. Acetate strongly repressed induction of n-hexadecane methylene hydroxylase activity. Inducibility of methylene hydroxylase activity was confirmed by use of cell-free systems with methylcyclohexane as an inducer. A stimulation of methylene hydroxylase activity by addition of reduced pyridine nucleotides and ferrous ion was indicated. PMID:5139534

  20. Additive Bilingualism, Schooling, and Special Education: A Minority Group Perspective.

    ERIC Educational Resources Information Center

    Landry, R.

    1987-01-01

    The effect of schooling on the acquisition of an additive type of bilingualism is examined, focusing on additive bilingualism's relation to the ethnolinguistic vitality of linguistic groups and contributions of individual networks of linguistic contacts. A special and regular education merger without domination by a single cultural perspective is…

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

    PubMed

    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. PMID:26984891

  2. 34 CFR 300.308 - Additional group members.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 2 2011-07-01 2010-07-01 true Additional group members. 300.308 Section 300.308 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN WITH DISABILITIES Evaluations,...

  3. 6-Propyl-2-thiouracil versus 6-methoxymethyl-2-thiouracil: enhancing the hydrogen-bonded synthon motif by replacement of a methylene group with an O atom.

    PubMed

    Hützler, Wilhelm Maximilian; Egert, Ernst; Bolte, Michael

    2016-08-01

    The understanding of intermolecular interactions is a key objective of crystal engineering in order to exploit the derived knowledge for the rational design of new molecular solids with tailored physical and chemical properties. The tools and theories of crystal engineering are indispensable for the rational design of (pharmaceutical) cocrystals. The results of cocrystallization experiments of the antithyroid drug 6-propyl-2-thiouracil (PTU) with 2,4-diaminopyrimidine (DAPY), and of 6-methoxymethyl-2-thiouracil (MOMTU) with DAPY and 2,4,6-triaminopyrimidine (TAPY), respectively, are reported. PTU and MOMTU show a high structural similarity and differ only in the replacement of a methylene group (-CH2-) with an O atom in the side chain, thus introducing an additional hydrogen-bond acceptor in MOMTU. Both molecules contain an ADA hydrogen-bonding site (A = acceptor and D = donor), while the coformers DAPY and TAPY both show complementary DAD sites and therefore should be capable of forming a mixed ADA/DAD synthon with each other, i.e. N-H...O, N-H...N and N-H...S hydrogen bonds. The experiments yielded one solvated cocrystal salt of PTU with DAPY, four different solvates of MOMTU, one ionic cocrystal of MOMTU with DAPY and one cocrystal salt of MOMTU with TAPY, namely 2,4-diaminopyrimidinium 6-propyl-2-thiouracilate-2,4-diaminopyrimidine-N,N-dimethylacetamide-water (1/1/1/1) (the systematic name for 6-propyl-2-thiouracilate is 6-oxo-4-propyl-2-sulfanylidene-1,2,3,6-tetrahydropyrimidin-1-ide), C4H7N4(+)·C7H9N2OS(-)·C4H6N4·C4H9NO·H2O, (I), 6-methoxymethyl-2-thiouracil-N,N-dimethylformamide (1/1), C6H8N2O2S·C3H7NO, (II), 6-methoxymethyl-2-thiouracil-N,N-dimethylacetamide (1/1), C6H8N2O2S·C4H9NO, (III), 6-methoxymethyl-2-thiouracil-dimethyl sulfoxide (1/1), C6H8N2O2S·C2H6OS, (IV), 6-methoxymethyl-2-thiouracil-1-methylpyrrolidin-2-one (1/1), C6H8N2O2S·C5H9NO, (V), 2,4-diaminopyrimidinium 6-methoxymethyl-2-thiouracilate (the systematic name for 6-methoxymethyl-2

  4. Fluorescence Spectrometric Determination of Drugs Containing α-Methylene Sulfone/Sulfonamide Functional Groups Using N1-Methylnicotinamide Chloride as a Fluorogenic Agent

    PubMed Central

    Elokely, Khaled M.; Eldawy, Mohamed A.; Elkersh, Mohamed A.; El-Moselhy, Tarek F.

    2011-01-01

    A simple spectrofluorometric method has been developed, adapted, and validated for the quantitative estimation of drugs containing α-methylene sulfone/sulfonamide functional groups using N1-methylnicotinamide chloride (NMNCl) as fluorogenic agent. The proposed method has been applied successfully to the determination of methyl sulfonyl methane (MSM) (1), tinidazole (2), rofecoxib (3), and nimesulide (4) in pure forms, laboratory-prepared mixtures, pharmaceutical dosage forms, spiked human plasma samples, and in volunteer's blood. The method showed linearity over concentration ranging from 1 to 150 μg/mL, 10 to 1000 ng/mL, 1 to 1800 ng/mL, and 30 to 2100 ng/mL for standard solutions of 1, 2, 3, and 4, respectively, and over concentration ranging from 5 to 150 μg/mL, 10 to 1000 ng/mL, 10 to 1700 ng/mL, and 30 to 2350 ng/mL in spiked human plasma samples of 1, 2, 3, and 4, respectively. The method showed good accuracy, specificity, and precision in both laboratory-prepared mixtures and in spiked human plasma samples. The proposed method is simple, does not need sophisticated instruments, and is suitable for quality control application, bioavailability, and bioequivalency studies. Besides, its detection limits are comparable to other sophisticated chromatographic methods. PMID:21647288

  5. Addition Theorems, Formal Group Laws and Integrable Systems

    NASA Astrophysics Data System (ADS)

    Buchstaber, V. M.; Bunkova, E. Yu.

    2010-11-01

    We consider elliptic curves, given in the Weierstrass parametrization by the equation y2+μ1xy+μ3y = x3+μ2x2+μ4x+μ6. In Tate coordinates t = -x/y and s = -1/y, the geometric addition laws on this curves correspond to the general elliptic formal group law over the ring Z[μ1,μ2,μ3,μ4,μ6]. This formal group law is well-known in the number theory and cryptography. One can find this law in recent works on the theory of elliptic functions and algebraic topology. In the focus of our interest are questions, important from the point of view of Hirzebruch genera and the theory of integrable systems (see references).

  6. Polyetherurethane oligomers with aldehyde groups as additives for lubricating oils

    SciTech Connect

    Nikolaev, V.N.; Abramov, E.G.; Tenyushev, A.I.

    1995-01-01

    Polyetherurethane oligomers with aldehyde groups, which we synthesized from polyoxypropylene diols (molecular weight 500, 1000, 1500, 2000, or 3000) with toluene diisocyanate and salicylaldehyde, are of interest as additives for lubricating oils. The effects of these oligomers on the service properties and physicochemical characteristics of lubricating oils were investigated by methods prreviously described. As the lube base stocks we used castor oil, a polyoxypropylene diol and a polyethoxysiloxane. The oligomers are readily soluble in organic solvents and in the lube base stocks, and their solutions are stable during storage and use. We found that the optimal concentration of oligomers is 5%, providing the best lubricating properties, in particular the best antiwear properties.

  7. Radical additions to chiral hydrazones: stereoselectivity and functional group compatibility.

    PubMed

    Friestad, Gregory K

    2012-01-01

    Free radical additions to imino compounds offer increased synthetic accessibility of chiral amines, but lack of general methods for stereocontrol has hindered their development. This review focuses on two asymmetric amine synthesis strategies designed to address this problem, with emphasis on addition of functionalized radicals which may facilitate applications to synthesis of complex targets. First, chiral N-acylhydrazones are acceptors for intermolecular radical additions of a wide range of primary, secondary, and tertiary alkyl halides to the C=N bond, with radicals generated under manganese-, tin-, or boron-mediated conditions. A variety of aldehydes and ketones serve as viable precursors for the chiral hydrazones, and the highly stereoselective reactions tolerate electrophilic functionality in both coupling components. Second, radical precursors may be linked to chiral α-hydroxyhydrazones via a silicon tether to the hydroxyl group; conformational constraints impart stereocontrol during 5-exo radical cyclization under stannyl- or thiyl-mediated conditions. The silicon tether may later be removed to reveal the formal adducts of hydroxymethyl, vinyl, acetyl, and 2-oxoethyl radicals to the C=N bond. Methodology development and applications to biologically important targets are discussed. PMID:21842359

  8. Methylene chloride poisoning in a cabinet worker.

    PubMed Central

    Mahmud, M; Kales, S N

    1999-01-01

    More than a million workers are at risk for methylene chloride exposure. Aerosol sprays and paint stripping may also cause significant nonoccupational exposures. After methylene chloride inhalation, significant amounts of carbon monoxide are formed in vivo as a metabolic by-product. Poisoning predominantly affects the central nervous system and results from both carboxyhemoglobin formation and direct solvent-related narcosis. In this report, we describe a case of methylene chloride intoxication probably complicated by exogenous carbon monoxide exposure. The worker's presentation of intermittent headaches was consistent with both methylene chloride intoxication and carbon monoxide poisoning. The exposures and symptoms were corroborated by elevated carboxyhemoglobin saturations and a workplace inspection that documented significant exposures to both methylene chloride and carbon monoxide. When both carbon monoxide and methylene chloride are inhaled, additional carboxyhemoglobin formation is expected. Preventive efforts should include education, air monitoring, and periodic carboxyhemoglobin determinations. Methylene chloride should never be used in enclosed or poorly ventilated areas because of the well-documented dangers of loss of consciousness and death. Images Figure 1 PMID:10464079

  9. Methylene blue unresponsive methemoglobinemia

    PubMed Central

    Patnaik, Sibabratta; Natarajan, Manivachagan Muthappa; James, Ebor Jacob; Ebenezer, Kala

    2014-01-01

    Acquired methemoglobinemia is an uncommon blood disorder induced by exposure to certain oxidizing agents and drugs. Although parents may not give any history of toxin ingestion; with the aid of pulse-oximetry and blood gas analysis, we can diagnose methemoglobinemia. Prompt recognition of this condition is required in emergency situations to institute early methylene blue therapy. We report an unusual case of severe toxic methemoglobinemia, which did not respond to methylene blue, but was successfully managed with exchange transfusion. PMID:24872659

  10. A Comparison of Group-Oriented Contingencies for Addition Fluency

    ERIC Educational Resources Information Center

    Gross, Thomas J.; Duhon, Gary J.; Shutte, Greg; Rowland, Julie E.

    2016-01-01

    Math fact fluency is critical for understanding complex mathematics. Explicit timing interventions have shown promise for improving math fluency, and they may benefit from being paired with group-oriented contingencies. Further, investigations of independent and dependent group-oriented contingencies would help to identify their relative…

  11. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  12. 34 CFR 300.308 - Additional group members.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Educational Placements Additional Procedures for Identifying Children with Specific Learning Disabilities... learning disability is a child with a disability as defined in § 300.8, must be made by the child's...

  13. 34 CFR 300.308 - Additional group members.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... examinations of children, such as a school psychologist, speech-language pathologist, or remedial reading... CHILDREN WITH DISABILITIES Evaluations, Eligibility Determinations, Individualized Education Programs, and Educational Placements Additional Procedures for Identifying Children with Specific Learning...

  14. 34 CFR 300.308 - Additional group members.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... examinations of children, such as a school psychologist, speech-language pathologist, or remedial reading... CHILDREN WITH DISABILITIES Evaluations, Eligibility Determinations, Individualized Education Programs, and Educational Placements Additional Procedures for Identifying Children with Specific Learning...

  15. Additions to the flora of the Wilcox group

    USGS Publications Warehouse

    Berry, Edward Wilber

    1923-01-01

    A rather full account of the extensive flora contained in the lower Eocene strata of the Mississippi embayment which are referred to the Wilcox group was published in 1916. At that time it was not possible to obtain sections of the numerous specimens of petrified wood that had been collected from these beds. These woods have since been sectioned and studied, and it seems eminently desirable to place the results of this study on record, for although much of the material had suffered greatly from decay before silicification, some of it is fairly well preserved and shows, among other results, that conifers were individually much more plentiful during Wilcox time than would be inferred from the almost total absence of their foliage in the very large collections of remains of this class that have been studied.

  16. 21 CFR 173.255 - Methylene chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methylene chloride. 173.255 Section 173.255 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Solvents, Lubricants, Release Agents and...

  17. 21 CFR 173.255 - Methylene chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Methylene chloride. 173.255 Section 173.255 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Solvents, Lubricants, Release Agents and...

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

    NASA Technical Reports Server (NTRS)

    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.

  19. Design, Synthesis, and Evaluation of 2-Amino-6-nitrobenzothiazole-Derived Hydrazones as MAO Inhibitors: Role of the Methylene Spacer Group.

    PubMed

    Tripathi, Rati K P; Ayyannan, Senthil R

    2016-07-19

    A series of 2-amino-6-nitrobenzothiazole-derived extended hydrazones were designed, synthesized, and investigated for their ability to inhibit monoamine oxidase A and B (MAO-A/MAO-B). The compounds were found to exhibit inhibitory activities in the nanomolar to micromolar range. Some of the compounds showed excellent potency and selectivity against the MAO-B isoform. N'-(5-Chloro-2-oxoindolin-3-ylidene)-2-(6-nitrobenzothiazol-2-ylamino)acetohydrazide (compound 31) showed the highest MAO-B inhibitory activity (IC50 =1.8±0.3 nm, selectivity index [SI]=766.67), whereas compound 6 [N'-(1-(4-bromophenyl)ethylidene)-2-(6-nitrobenzothiazol-2-ylamino)acetohydrazide] was found to be the most active MAO-A inhibitor (IC50 =0.42±0.003 μm). Kinetic studies revealed that compounds 6 and 31 exhibit competitive-type reversible inhibition against both MAO-A and MAO-B, respectively. Structure-activity relationship (SAR) studies disclosed several structural aspects significant for potency and the contribution of the methylene spacer toward MAO-B inhibitory potency, with minimal or no neurotoxicity. Molecular modeling studies yielded a good correlation between experimental and theoretical inhibitory data. Binding pose analysis revealed the significance of cumulative effects of π-π stacking and hydrogen bond interactions for effective stabilization of virtual ligand-protein complexes. Further optimization studies of compound 31, including co-crystallization of inhibitor-MAO-B complexes, are essential to develop these compounds as potential therapeutic agents for MAO-B-associated neurodegenerative diseases. PMID:27332045

  20. 40 CFR 79.56 - Fuel and fuel additive grouping system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Fuel and fuel additive grouping system. 79.56 Section 79.56 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGISTRATION OF FUELS AND FUEL ADDITIVES Testing Requirements for Registration § 79.56 Fuel and fuel additive grouping system....

  1. Additivity of Feature-Based and Symmetry-Based Grouping Effects in Multiple Object Tracking

    PubMed Central

    Wang, Chundi; Zhang, Xuemin; Li, Yongna; Lyu, Chuang

    2016-01-01

    Multiple object tracking (MOT) is an attentional process wherein people track several moving targets among several distractors. Symmetry, an important indicator of regularity, is a general spatial pattern observed in natural and artificial scenes. According to the “laws of perceptual organization” proposed by Gestalt psychologists, regularity is a principle of perceptual grouping, such as similarity and closure. A great deal of research reported that feature-based similarity grouping (e.g., grouping based on color, size, or shape) among targets in MOT tasks can improve tracking performance. However, no additive feature-based grouping effects have been reported where the tracking objects had two or more features. “Additive effect” refers to a greater grouping effect produced by grouping based on multiple cues instead of one cue. Can spatial symmetry produce a similar grouping effect similar to that of feature similarity in MOT tasks? Are the grouping effects based on symmetry and feature similarity additive? This study includes four experiments to address these questions. The results of Experiments 1 and 2 demonstrated the automatic symmetry-based grouping effects. More importantly, an additive grouping effect of symmetry and feature similarity was observed in Experiments 3 and 4. Our findings indicate that symmetry can produce an enhanced grouping effect in MOT and facilitate the grouping effect based on color or shape similarity. The “where” and “what” pathways might have played an important role in the additive grouping effect. PMID:27199875

  2. Additivity of Feature-Based and Symmetry-Based Grouping Effects in Multiple Object Tracking.

    PubMed

    Wang, Chundi; Zhang, Xuemin; Li, Yongna; Lyu, Chuang

    2016-01-01

    Multiple object tracking (MOT) is an attentional process wherein people track several moving targets among several distractors. Symmetry, an important indicator of regularity, is a general spatial pattern observed in natural and artificial scenes. According to the "laws of perceptual organization" proposed by Gestalt psychologists, regularity is a principle of perceptual grouping, such as similarity and closure. A great deal of research reported that feature-based similarity grouping (e.g., grouping based on color, size, or shape) among targets in MOT tasks can improve tracking performance. However, no additive feature-based grouping effects have been reported where the tracking objects had two or more features. "Additive effect" refers to a greater grouping effect produced by grouping based on multiple cues instead of one cue. Can spatial symmetry produce a similar grouping effect similar to that of feature similarity in MOT tasks? Are the grouping effects based on symmetry and feature similarity additive? This study includes four experiments to address these questions. The results of Experiments 1 and 2 demonstrated the automatic symmetry-based grouping effects. More importantly, an additive grouping effect of symmetry and feature similarity was observed in Experiments 3 and 4. Our findings indicate that symmetry can produce an enhanced grouping effect in MOT and facilitate the grouping effect based on color or shape similarity. The "where" and "what" pathways might have played an important role in the additive grouping effect. PMID:27199875

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

    PubMed

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

    2015-01-01

    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. PMID:26400108

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

    PubMed Central

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

    2015-01-01

    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. PMID:26400108

  5. Alkenes as Chelating Groups in Diastereoselective Additions of Organometallics to Ketones

    PubMed Central

    2015-01-01

    Alkenes have been discovered to be chelating groups to Zn(II), enforcing highly stereoselective additions of organozincs to β,γ-unsaturated ketones. 1H NMR studies and DFT calculations provide support for this surprising chelation mode. The results expand the range of coordinating groups for chelation-controlled carbonyl additions from heteroatom Lewis bases to simple C–C double bonds, broadening the 60 year old paradigm. PMID:25328269

  6. Defense style changes with the addition of psychodynamic group therapy to clonazepam in social anxiety disorder.

    PubMed

    Knijnik, Daniela Z; Salum, Giovanni Abrahão; Blanco, Carlos; Moraes, Carolina; Hauck, Simone; Mombach, Clarissa K; Strapasson, Atahualpa C P; Manfro, Gisele G; Eizirik, Cláudio L

    2009-07-01

    Psychodynamic Group Therapy (PGT) and clonazepam are strategies to reduce symptoms of generalized social anxiety disorder (GSAD). The addition of PGT might lead to changes in defense styles. The objective of this study is to examine changes in defense styles when comparing clonazepam to psychodynamic group therapy plus clonazepam in GSAD during 12 weeks. Fifty-seven patients that met DSM-IV criteria for GSAD participated. social anxiety disorder symptoms were evaluated with the Liebowitz Social Anxiety Scale, and defense styles with the Defense Style Questionnaire. All defense styles changed overtime for both groups, especially mature defense style, which increased independently of the treatment allocation group. Regression analyses found that overtime there was a reduction in neurotic defenses in the combined group, whereas there was an increase in the clonazepam group. Neurotic defense style can change toward greater adaptiveness with the addition of PGT to clonazepam in GSAD, even in 12 weeks. PMID:19597364

  7. Neurometabolic mechanisms for memory enhancement and neuroprotection of methylene blue

    PubMed Central

    Rojas, Julio C.; Bruchey, Aleksandra K.; Gonzalez-Lima, F.

    2011-01-01

    This paper provides the first review of the memory-enhancing and neuroprotective metabolic mechanisms of action of methylene blue in vivo. These mechanisms have important implications as a new neurobiological approach to improve normal memory and to treat memory impairment and neurodegeneration associated with mitochondrial dysfunction. Methylene blue’s action is unique because its neurobiological effects are not determined by regular drug-receptor interactions or drug-response paradigms. Methylene blue shows a hormetic dose-response, with opposite effects at low and high doses. At low doses, methylene blue is an electron cycler in the mitochondrial electron transport chain, with unparalleled antioxidant and cell respiration-enhancing properties that affect the function of the nervous system in a versatile manner. A major role of the respiratory enzyme cytochrome oxidase on the memory-enhancing effects of methylene blue is supported by available data. The memory-enhancing effects have been associated with improvement of memory consolidation in a network-specific and use-dependent fashion. In addition, low doses of methylene blue have also been used for neuroprotection against mitochondrial dysfunction in humans and experimental models of disease. The unique auto-oxidizing property of methylene blue and its pleiotropic effects on a number of tissue oxidases explain its potent neuroprotective effects at low doses. The evidence reviewed supports a mechanistic role of low-dose methylene blue as a promising and safe intervention for improving memory and for the treatment of acute and chronic conditions characterized by increased oxidative stress, neurodegeneration and memory impairment. PMID:22067440

  8. Methylene blue related sterile endophthalmitis.

    PubMed

    Lim, A K E; Ulagantheran V, V; Siow, Y C; Lim, K S

    2008-08-01

    To report a case of methylene blue related endophthalmitis. Observational case report. Review of clinical record, photographs. A 60 year old man developed endophthalmitis after methylene blue was accidentally used to stain the anterior capsule during phacoemulsification of cataract. His left visual acuity deteriorated from 6/12 to 6/36 two weeks after the operation. Despite intensive treatment with topical and intravitreal antibiotics, his condition deteriorated. A vitrectomy and silicone oil injection eventually managed to control the progression of the disease and salvage the eye. However the visual outcome remained poor due to corneal decompensation and retinal ischemia. Both vitreous tap and vitreous biopsy were negative for any organism. Methylene blue is extremely toxic to ocular structures and should not be used intraocularly. PMID:19248701

  9. Effects of methylene blue in acute lung injury induced by blunt chest trauma

    PubMed Central

    Ayvaz, S; Aksu, B; Karaca, T; Cemek, M; Tarladacalisir, Y-T; Ayaz, A; Metin, M-S; Basaran, UN; Ayvaz, A-T; Aksu, F; Pul, M

    2014-01-01

    Background: We studied whether methylene blue (MB) treatment blunts chest trauma-induced lung injury in rats. Material and Methods: Forty male Sprague-Dawley rats, 200-300g, were used. The rats were divided into five groups (n=8): control, early contusion (EC), early contusion + methylene blue (2 mg/kg, EC+MB), late contusion (LC), and late contusion + methylene blue (2 mg/kg, LC+MB). Results: Histopathological analysis showed increased hemorrhage, alveolar wall thickness, edema, and inflammatory cell infiltrates in the EC and LC rats, which decreased upon MB treatment. Immunohistochemical studies revealed that MB reduced activation of inducible nitric oxide synthase (iNOS) and the number of active terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells. A significant increase was observed in the malondialdehyde (MDA) and nitric oxide (NO) levels in the EC group compared to the control group (p<0.05). In addition, a significant decrease was reported in the glutathione (GSH), superoxide dismutase (SOD), and glutathione peroxidase (GPx) levels (p<0.01), but no significant difference was observed in the catalase (CAT) levels among the groups. The MDA level was significantly higher in the LC group compared to the control group, whereas the GSH level was significantly lower compared to the control group. The NO level in the EC+MB group was significantly lower when compared to the NO level in the EC group (p<0.05). Conclusion: The present study provides evidence that MB might serve as a therapeutic treatment for blunt chest trauma. PMID:25125953

  10. Testing for Additivity at Select Mixture Groups of Interest Based on Statistical Equivalence Testing Methods

    SciTech Connect

    Stork, LeAnna M.; Gennings, Chris; Carchman, Richard; Carter, Jr., Walter H.; Pounds, Joel G.; Mumtaz, Moiz

    2006-12-01

    Several assumptions, defined and undefined, are used in the toxicity assessment of chemical mixtures. In scientific practice mixture components in the low-dose region, particularly subthreshold doses, are often assumed to behave additively (i.e., zero interaction) based on heuristic arguments. This assumption has important implications in the practice of risk assessment, but has not been experimentally tested. We have developed methodology to test for additivity in the sense of Berenbaum (Advances in Cancer Research, 1981), based on the statistical equivalence testing literature where the null hypothesis of interaction is rejected for the alternative hypothesis of additivity when data support the claim. The implication of this approach is that conclusions of additivity are made with a false positive rate controlled by the experimenter. The claim of additivity is based on prespecified additivity margins, which are chosen using expert biological judgment such that small deviations from additivity, which are not considered to be biologically important, are not statistically significant. This approach is in contrast to the usual hypothesis-testing framework that assumes additivity in the null hypothesis and rejects when there is significant evidence of interaction. In this scenario, failure to reject may be due to lack of statistical power making the claim of additivity problematic. The proposed method is illustrated in a mixture of five organophosphorus pesticides that were experimentally evaluated alone and at relevant mixing ratios. Motor activity was assessed in adult male rats following acute exposure. Four low-dose mixture groups were evaluated. Evidence of additivity is found in three of the four low-dose mixture groups.The proposed method tests for additivity of the whole mixture and does not take into account subset interactions (e.g., synergistic, antagonistic) that may have occurred and cancelled each other out.

  11. Addition of lysophospholipids with large head groups to cells inhibits Shiga toxin binding

    PubMed Central

    Ailte, Ieva; Lingelem, Anne Berit Dyve; Kavaliauskiene, Simona; Bergan, Jonas; Kvalvaag, Audun Sverre; Myrann, Anne-Grethe; Skotland, Tore; Sandvig, Kirsten

    2016-01-01

    Shiga toxin (Stx), an AB5 toxin, binds specifically to the neutral glycosphingolipid Gb3 at the cell surface before being transported into cells. We here demonstrate that addition of conical lysophospholipids (LPLs) with large head groups inhibit Stx binding to cells whereas LPLs with small head groups do not. Lysophosphatidylinositol (LPI 18:0), the most efficient LPL with the largest head group, was selected for in-depth investigations to study how the binding of Stx is regulated. We show that the inhibition of Stx binding by LPI is reversible and possibly regulated by cholesterol since addition of methyl-β-cyclodextrin (mβCD) reversed the ability of LPI to inhibit binding. LPI-induced inhibition of Stx binding is independent of signalling and membrane turnover as it occurs in fixed cells as well as after depletion of cellular ATP. Furthermore, data obtained with fluorescent membrane dyes suggest that LPI treatment has a direct effect on plasma membrane lipid packing with shift towards a liquid disordered phase in the outer leaflet, while lysophosphoethanolamine (LPE), which has a small head group, does not. In conclusion, our data show that cellular treatment with conical LPLs with large head groups changes intrinsic properties of the plasma membrane and modulates Stx binding to Gb3. PMID:27458147

  12. Addition of lysophospholipids with large head groups to cells inhibits Shiga toxin binding.

    PubMed

    Ailte, Ieva; Lingelem, Anne Berit Dyve; Kavaliauskiene, Simona; Bergan, Jonas; Kvalvaag, Audun Sverre; Myrann, Anne-Grethe; Skotland, Tore; Sandvig, Kirsten

    2016-01-01

    Shiga toxin (Stx), an AB5 toxin, binds specifically to the neutral glycosphingolipid Gb3 at the cell surface before being transported into cells. We here demonstrate that addition of conical lysophospholipids (LPLs) with large head groups inhibit Stx binding to cells whereas LPLs with small head groups do not. Lysophosphatidylinositol (LPI 18:0), the most efficient LPL with the largest head group, was selected for in-depth investigations to study how the binding of Stx is regulated. We show that the inhibition of Stx binding by LPI is reversible and possibly regulated by cholesterol since addition of methyl-β-cyclodextrin (mβCD) reversed the ability of LPI to inhibit binding. LPI-induced inhibition of Stx binding is independent of signalling and membrane turnover as it occurs in fixed cells as well as after depletion of cellular ATP. Furthermore, data obtained with fluorescent membrane dyes suggest that LPI treatment has a direct effect on plasma membrane lipid packing with shift towards a liquid disordered phase in the outer leaflet, while lysophosphoethanolamine (LPE), which has a small head group, does not. In conclusion, our data show that cellular treatment with conical LPLs with large head groups changes intrinsic properties of the plasma membrane and modulates Stx binding to Gb3. PMID:27458147

  13. Side Group Addition to the PAH Coronene by UV Photolysis in Cosmic Ice Analogs

    NASA Technical Reports Server (NTRS)

    Bernstein, Max P.; Elsila, Jamie E.; Dworkin, Jason P.; Sandford, Scott A.; Allamandola, Louis J.; Zare, Richard N.; DeVincenzi, D. (Technical Monitor)

    2002-01-01

    Ultraviolet photolysis of various ice mixtures at low temperature and pressure caused the addition of amino (-NH2), methyl (-CH3), methoxy (-OCH3), and cyano (-CN) functional groups to the polycyclic aromatic hydrocarbon (PAH) coronene (C22H12). The implications of these results for interstellar and meteoritic chemistry are discussed. Previously only simple PAH photo-oxidation had been reported. This work represents the first experimental evidence that ice photochemistry may have contributed to aromatics bearing carbon and nitrogen containing side groups that are detected in primitive meteorites and interplanetary dust particles. Furthermore, these results suggest a wider range of modified PAHs should be expected in interstellar lees and materials predating solar system formation.

  14. ProPhenol-Catalyzed Asymmetric Additions by Spontaneously Assembled Dinuclear Main Group Metal Complexes

    PubMed Central

    2016-01-01

    Conspectus The development of catalytic enantioselective transformations has been the focus of many research groups over the past half century and is of paramount importance to the pharmaceutical and agrochemical industries. Since the award of the Nobel Prize in 2001, the field of enantioselective transition metal catalysis has soared to new heights, with the development of more efficient catalysts and new catalytic transformations at increasing frequency. Furthermore, catalytic reactions that allow higher levels of redox- and step-economy are being developed. Thus, alternatives to asymmetric alkene dihydroxylation and the enantioselective reduction of α,β-unsaturated ketones can invoke more strategic C–C bond forming reactions, such as asymmetric aldol reactions of an aldehyde with α-hydroxyketone donors or enantioselective alkynylation of an aldehyde, respectively. To facilitate catalytic enantioselective addition reactions, including the aforementioned aldol and alkynylation reactions, our lab has developed the ProPhenol ligand. In this Account, we describe the development and application of the ProPhenol ligand for asymmetric additions of both carbon- and heteroatom-based nucleophiles to various electrophiles. The ProPhenol ligand spontaneously forms chiral dinuclear metal complexes when treated with an alkyl metal reagent, such as Et2Zn or Bu2Mg. The resulting complex contains both a Lewis acidic site to activate an electrophile and a Brønsted basic site to deprotonate a pronucleophile. Initially, our research focused on the use of Zn-ProPhenol complexes to facilitate the direct aldol reaction. Fine tuning of the reaction through ligand modification and the use of additives enabled the direct aldol reaction to proceed in high yields and stereoselectivities with a broad range of donor substrates, including acetophenones, methyl ynones, methyl vinyl ketone, acetone, α-hydroxy carbonyl compounds, and glycine Schiff bases. Additionally, an analogous

  15. 29 CFR 1910.1052 - Methylene Chloride.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 6 2012-07-01 2012-07-01 false Methylene Chloride. 1910.1052 Section 1910.1052 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS (CONTINUED) Toxic and Hazardous Substances § 1910.1052 Methylene Chloride. This...

  16. Radical Energies and the Regiochemistry of Addition to Heme Groups. Methylperoxy and Nitrite Radical Additions to the Heme of Horseradish Peroxidase

    PubMed Central

    Wojciechowski, Grzegorz; Ortiz de Montellano, Paul R.

    2008-01-01

    The heme of hemoproteins, as exemplified by horseradish peroxidase (HRP), can undergo additions at the meso carbons and/or vinyl groups of the electrophilic or radical species generated in the catalytic oxidation of halides, pseudohalides, carboxylic acids, aryl and alkyl hydrazines, and other substrates. The determinants of the regiospecificity of these reactions, however, are unclear. We report here modification of the heme of HRP by autocatalytically generated, low energy NO2• and CH3OO• radicals. The NO2• radical adds regioselectively to the 4- over the 2-vinyl group but does not add to the meso positions. Reaction of HRP with tert-BuOOH does not lead to heme modification, but reaction with the F152M mutant, in which the heme vinyls are more sterically accessible, results in conversion of the heme 2-vinyl into a 1-hydroxy-2-(methylperoxy)-ethyl group [-CH(OH)CH2OOCH3]. [18O]-labeling studies indicate that the hydroxyl group in this adduct derives from water and the methylperoxide oxygens from O2. Under anaerobic conditions, methyl radicals formed by fragmentation of the autocatalytically generated tert-BuO• radical add to both the δ-meso-carbon and the 2-vinyl group. The regiochemistry of these and the other known additions to the heme indicate that only high-energy radicals (e.g., CH3•) add to the meso-carbon. Less energetic radicals, including NO2• and CH3OO•, add to heme vinyl groups if they are small enough but do not add to the meso-carbons. Electrophilic species such as HOBr, HOCl, and HOSCN add to vinyl groups but do not react with the meso-carbons. This meso- versus vinyl-reactivity paradigm, which appears to be general for autocatalytic additions to heme prosthetic groups, suggests that meso-hydroxylation of the heme by heme oxygenase occurs by a controlled radical reaction rather than by electrophilic addition. PMID:17249668

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

    PubMed

    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. PMID:22357403

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

    PubMed Central

    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, P<0.01), but the staining capacity of MLM is higher than that of methylene 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. PMID:26221301

  19. Extended orientational correlation study for molecular liquids containing distorted tetrahedral molecules: application to methylene halides.

    PubMed

    Pothoczki, Szilvia; Temleitner, László; Pusztai, László

    2010-04-28

    The method of Rey [Rey, J. Chem. Phys. 126, 164506 (2007)] for describing how molecules orient toward each other in systems with perfect tetrahedral molecules is extended to the case of distorted tetrahedral molecules of c(2v) symmetry by means of introducing 28 subgroups. Additionally, the original analysis developed for perfect tetrahedral molecules, based on six groups, is adapted for molecules with imperfect tetrahedral shape. Deriving orientational correlation functions have been complemented with detailed analyses of dipole-dipole correlations. This way, (up to now) the most complete structure determination can be carried out for such molecular systems. In the present work, these calculations have been applied for particle configurations resulting from reverse Monte Carlo computer modeling. These particle arrangements are fully consistent with structure factors from neutron and x-ray diffraction measurements. Here we present a complex structural study for methylene halide (chloride, bromide, and iodide) molecular liquids, as possibly the best representative examples. It has been found that the most frequent orientations of molecules are of the 2:2 type over the entire distance range in these liquids. Focusing on the short range orientation, neighboring molecules turn toward each other with there "H,Y"-"H,Y" (Y: Cl, Br, I) edges, apart from CH(2)Cl(2) where the H,H-H,Cl arrangement is the most frequent. In general, the structure of methylene chloride appears to be different from the structure of the other two liquids. PMID:20441292

  20. Additional Validity Evidence and Across-Group Equivalency of the "HOPE Teacher Rating Scale"

    ERIC Educational Resources Information Center

    Peters, Scott J.; Gentry, Marcia

    2013-01-01

    The "HOPE Scale" was developed to identify academic and social components of giftedness and talent in elementary-aged students with particular attention to students from low-income and/or culturally diverse families. Based on previous findings, additional research was conducted on revisions made to the "HOPE Scale". Items were added, and 71…

  1. Multi-Walled Carbon Nanotube Functionalization by Radical Addition Using Hydroxymethylene Groups.

    PubMed

    Rodríguez-Jiménez, Rubén; Alonso-Núñez, Gabriel; Paraguay-Delgado, Francisco; Espinoza-Gómez, Heriberto; Vélez-López, Ernesto; Rogel-Hernández, Eduardo

    2016-01-01

    Synthetic methodology and characterization of multi-walled carbon nanotubes (MWCNTs) function- alized with hydroxymethylene groups are reported. The MWCNTs were synthesized by the spray pyrolysis technique using toluene as carbon source and ferrocene as catalyst. Hydroxymethylation of MWCNTs was carried out by methanol using benzoyl peroxide (BPO) at different quantities (300 to 900 mg); the optimum BPO quantity was 300 mg. The resulting materials were characterized by FT-IR, Raman Spectroscopy, Thermal Gravimetric Analysis (TGA) and Transmission Electron Microscopy (TEM). The presence of the hydroxymethylene group on the MWCNTs surface was demonstrated by FT-IR, Raman Spectroscopy, TGA, EDS, TEM and Mass Spectrometry. The func- tionalized MWCNTs were not damaged by this methodology. PMID:27398563

  2. New addition curing polyimides

    NASA Technical Reports Server (NTRS)

    Frimer, Aryeh A.; Cavano, Paul

    1991-01-01

    In an attempt to improve the thermal-oxidative stability (TOS) of PMR-type polymers, the use of 1,4-phenylenebis (phenylmaleic anhydride) PPMA, was evaluated. Two series of nadic end-capped addition curing polyimides were prepared by imidizing PPMA with either 4,4'-methylene dianiline or p-phenylenediamine. The first resulted in improved solubility and increased resin flow while the latter yielded a compression molded neat resin sample with a T(sub g) of 408 C, close to 70 C higher than PME-15. The performance of these materials in long term weight loss studies was below that of PMR-15, independent of post-cure conditions. These results can be rationalized in terms of the thermal lability of the pendant phenyl groups and the incomplete imidization of the sterically congested PPMA. The preparation of model compounds as well as future research directions are discussed.

  3. Influence of group composition of sulfonic acids on properties of sulfonate additives

    SciTech Connect

    Katrenko, T.I.; Bessonova, R.N.; Kuznetsova, M.G.; Potolovskii, L.A.

    1983-05-01

    Three types of sulfonic acids are formed in sulfonation of petroleum oils-- oil-soluble, oil-insoluble, and water-soluble. This study investigates the influence of the different acids on neutral calcium sulfonates. Samples are recovered from As-14 oil. Oil-insoluble synthesis failed. Water-soluble acid did synthesize with a mix of oil- and water-soluble sulfonates. Neutral calcium sulfonates synthesized from oil-soluble had good properties, from oil-insoluble, bad properties. Oil-insoluble sulfonate also has an inverse effect on cleanup, and it interferes with carbonation. These findings will help with improvements in the sulfonate additive manufacturing process.

  4. Bath additives for the treatment of childhood eczema (BATHE): protocol for multicentre parallel group randomised trial

    PubMed Central

    Santer, Miriam; Rumsby, Kate; Ridd, Matthew J; Francis, Nick A; Stuart, Beth; Chorozoglou, Maria; Wood, Wendy; Roberts, Amanda; Thomas, Kim S; Williams, Hywel C; Little, Paul

    2015-01-01

    Introduction Bath emollients are widely prescribed for childhood eczema, yet evidence of their benefits over direct application of emollients is lacking. Objectives To determine the clinical and cost-effectiveness of adding bath emollient to the standard management of eczema in children Methods and analysis Design: Pragmatic open 2-armed parallel group randomised controlled trial. Setting: General practitioner (GP) practices in England and Wales. Participants: Children aged over 12 months and less than 12 years with eczema, excluding inactive or very mild eczema (5 or less on Nottingham Eczema Severity Scale). Interventions: Children will be randomised to either bath emollients plus standard eczema care or standard eczema care only. Outcome measures: Primary outcome is long-term eczema severity, measured by the Patient-Oriented Eczema Measure (POEM) repeated weekly for 16 weeks. Secondary outcomes include: number of eczema exacerbations resulting in healthcare consultations over 1 year; eczema severity over 1 year; disease-specific and generic quality of life; medication use and healthcare resource use; cost-effectiveness. Aiming to detect a mean difference between groups of 2.0 (SD 7.0) in weekly POEM scores over 16 weeks (significance 0.05, power 0.9), allowing for 20% loss to follow-up, gives a total sample size of 423 children. We will use repeated measures analysis of covariance, or a mixed model, to analyse weekly POEM scores. We will control for possible confounders, including baseline eczema severity and child's age. Cost-effectiveness analysis will be carried out from a National Health Service (NHS) perspective. Ethics and dissemination This protocol was approved by Newcastle and North Tyneside 1 NRES committee 14/NE/0098. Follow-up will be completed in 2017. Findings will be disseminated to participants and carers, the public, dermatology and primary care journals, guideline developers and decision-makers. Trial registration number ISRCTN

  5. Additive opportunistic capture explains group hunting benefits in African wild dogs

    PubMed Central

    Hubel, Tatjana Y.; Myatt, Julia P.; Jordan, Neil R.; Dewhirst, Oliver P.; McNutt, J. Weldon; Wilson, Alan M.

    2016-01-01

    African wild dogs (Lycaon pictus) are described as highly collaborative endurance pursuit hunters based on observations derived primarily from the grass plains of East Africa. However, the remaining population of this endangered species mainly occupies mixed woodland savannah where hunting strategies appear to differ from those previously described. We used high-resolution GPS and inertial technology to record fine-scale movement of all members of a single pack of six adult African wild dogs in northern Botswana. The dogs used multiple short-distance hunting attempts with a low individual kill rate (15.5%), but high group feeding rate due to the sharing of prey. Use of high-level cooperative chase strategies (coordination and collaboration) was not recorded. In the mixed woodland habitats typical of their current range, simultaneous, opportunistic, short-distance chasing by dogs pursuing multiple prey (rather than long collaborative pursuits of single prey by multiple individuals) could be the key to their relative success in these habitats. PMID:27023355

  6. Additive opportunistic capture explains group hunting benefits in African wild dogs.

    PubMed

    Hubel, Tatjana Y; Myatt, Julia P; Jordan, Neil R; Dewhirst, Oliver P; McNutt, J Weldon; Wilson, Alan M

    2016-01-01

    African wild dogs (Lycaon pictus) are described as highly collaborative endurance pursuit hunters based on observations derived primarily from the grass plains of East Africa. However, the remaining population of this endangered species mainly occupies mixed woodland savannah where hunting strategies appear to differ from those previously described. We used high-resolution GPS and inertial technology to record fine-scale movement of all members of a single pack of six adult African wild dogs in northern Botswana. The dogs used multiple short-distance hunting attempts with a low individual kill rate (15.5%), but high group feeding rate due to the sharing of prey. Use of high-level cooperative chase strategies (coordination and collaboration) was not recorded. In the mixed woodland habitats typical of their current range, simultaneous, opportunistic, short-distance chasing by dogs pursuing multiple prey (rather than long collaborative pursuits of single prey by multiple individuals) could be the key to their relative success in these habitats. PMID:27023355

  7. Anaerobic Activation of p-Cymene in Denitrifying Betaproteobacteria: Methyl Group Hydroxylation versus Addition to Fumarate

    PubMed Central

    Strijkstra, Annemieke; Trautwein, Kathleen; Jarling, René; Wöhlbrand, Lars; Dörries, Marvin; Reinhardt, Richard; Drozdowska, Marta; Golding, Bernard T.; Wilkes, Heinz

    2014-01-01

    The betaproteobacteria “Aromatoleum aromaticum” pCyN1 and “Thauera” sp. strain pCyN2 anaerobically degrade the plant-derived aromatic hydrocarbon p-cymene (4-isopropyltoluene) under nitrate-reducing conditions. Metabolite analysis of p-cymene-adapted “A. aromaticum” pCyN1 cells demonstrated the specific formation of 4-isopropylbenzyl alcohol and 4-isopropylbenzaldehyde, whereas with “Thauera” sp. pCyN2, exclusively 4-isopropylbenzylsuccinate and tentatively identified (4-isopropylphenyl)itaconate were observed. 4-Isopropylbenzoate in contrast was detected with both strains. Proteogenomic investigation of p-cymene- versus succinate-adapted cells of the two strains revealed distinct protein profiles agreeing with the different metabolites formed from p-cymene. “A. aromaticum” pCyN1 specifically produced (i) a putative p-cymene dehydrogenase (CmdABC) expected to hydroxylate the benzylic methyl group of p-cymene, (ii) two dehydrogenases putatively oxidizing 4-isopropylbenzyl alcohol (Iod) and 4-isopropylbenzaldehyde (Iad), and (iii) the putative 4-isopropylbenzoate-coenzyme A (CoA) ligase (Ibl). The p-cymene-specific protein profile of “Thauera” sp. pCyN2, on the other hand, encompassed proteins homologous to subunits of toluene-activating benzylsuccinate synthase (termed [4-isopropylbenzyl]succinate synthase IbsABCDEF; identified subunits, IbsAE) and protein homologs of the benzylsuccinate β-oxidation (Bbs) pathway (termed BisABCDEFGH; all identified except for BisEF). This study reveals that two related denitrifying bacteria employ fundamentally different peripheral degradation routes for one and the same substrate, p-cymene, with the two pathways apparently converging at the level of 4-isopropylbenzoyl-CoA. PMID:25261521

  8. On methylene-bridged cysteine and lysine residues in proteins.

    PubMed

    Ruszkowski, Milosz; Dauter, Zbigniew

    2016-09-01

    Cysteine residues ubiquitously stabilize tertiary and quaternary protein structure by formation of disulfide bridges. Here we investigate another linking interaction that involves sulfhydryl groups of cysteines, namely intra- and intermolecular methylene-bridges between cysteine and lysine residues. A number of crystal structures possessing such a linkage were identified in the Protein Data Bank. Inspection of the electron density maps and re-refinement of the nominated structures unequivocally confirmed the presence of Lys-CH2 -Cys bonds in several cases. PMID:27261771

  9. Safe thyroidectomy with intraoperative methylene blue spraying

    PubMed Central

    2012-01-01

    Background We aimed to minimalize operative complications by spraying of methylene blue stain on thyroid glands and the perithyroidal area. Material and methods The intra-operative methylene blue spraying technique was used prospectively on a total of 56 patients who had undergone primary (not recurrent) thyroid surgery for a variety of thyroid diseases. Bilateral total thyroidectomy was performed in all cases. After superior but before inferior pole ligation, 0.5ml of methylene blue was sprayed over the thyroid lobe and perilober area. Tissues, especially parathyroides, the recurrent laryngeal nerve, and the inferior thyroid artery, were identified and evaluated. Results Recurrent laryngeal nerve and arteries were not stained and thus they remained white in all cases while all other tissues were stained blue. Within three minutes parathyroid glands washed out the blue stain and the original yellow color was regained. Thyroid tissue wash-out time was not less than 15 minutes; perithyroideal muscles, tendinous and lipoid structures took no less than 25 minutes. Conclusion The safety of intravascular methylene blue guidance on thyroid surgery is known. This research demonstrates the effectiveness of the spraying technique, a new technique which ensures not only identification of parathyroid glands within three minutes, but also identification of recurrent laryngeal nerves and inferior thyroid arteries. PMID:23148801

  10. Methylene Salicylicacidyl Hexamer (MSH) Has DNAse Activity.

    PubMed

    Tiwari, Ankit; Gade, Chandrasekhar Reddy; Dixit, Manjusha; Sharma, Nagendra K

    2015-07-01

    Salicylic acid and formaldehyde form heterogenous methyl/methylene salicylicacidyl oligomers and polymers in presence of sulfuric acid (H2SO4) and sodium nitrite (NaNO2). One of the oligomers as aurintricarboxylic acid (ATA), methelene bridged salicylic acid trimer, has been identified and explored in biochemical research, which is a potent inhibitor of many biological processes. A very few reports are also available on dimer, trimer, and tetramer of methelene bridged salicylic acids from same reaction mixture. Herein, we report the isolation and biochemical screening of partial purified low-molecular component as methylene salicylicacidyl hexamer (MSH) from the above reaction mixture. The interaction of methylene salicylicacidyl oligomer with DNA was studied by agarose and polyacrylamide gel electrophoresis, which suggest that methylene salicylicacidyl oligomer has DNAse activity. So far, no such significant reports are available on low-molecular oligomer of methelene bridged salicylic acids. In further, we also attempted to investigate the nature of nuclease activity, which clearly indicates DNA exonuclease type of activity. Further studies are needed to establish the mechanism of actions. PMID:26077682

  11. Allene Functionalization via Bicyclic Methylene Aziridines

    PubMed Central

    Boralsky, Luke A.; Marston, Dagmara; Grigg, R. David; Hershberger, John C.; Schomaker, Jennifer M.

    2011-01-01

    The oxidative functionalization of olefins is a common method for the formation of vicinal carbon-heteroatom bonds. However, oxidative methods to transform allenes into synthetic motifs containing three contiguous carbon-heteroatom bonds are much less developed. This paper describes the use of bicyclic methylene aziridines (MAs), prepared via intramolecular allene aziridination, as scaffolds for functionalization of all three allene carbons. PMID:21438516

  12. Tosvinyl and besvinyl as protecting groups of imides, azinones, nucleosides, sultams, and lactams. Catalytic conjugate additions to tosylacetylene.

    PubMed

    Petit, Elena; Bosch, Lluís; Font, Joan; Mola, Laura; Costa, Anna M; Vilarrasa, Jaume

    2014-09-19

    The use of the 2-(4-methylphenylsulfonyl)ethenyl (tosvinyl, Tsv) group for the protection of the NH group of a series of imides, azinones (including AZT), inosines, and cyclic sulfonamides has been examined. The Tsv-protected derivatives are obtained in excellent yields by conjugate addition to tosylacetylene (ethynyl p-tolyl sulfone). The stereochemistry of the double bond can be controlled at will: with only 1 mol % of Et3N or with catalytic amounts of NaH, the Z stereoisomers are generated almost exclusively, while the E isomers are obtained using a stoichiometric amount of DMAP. Analogous phenylsulfonylvinyl-protected groups (with the besvinyl or Bsv group instead of Tsv) are obtained stereospecifically by reaction with (Z)- or (E)-bis(phenylsulfonyl)ethene. For lactams and oxazolidinones, this last method is much better. The Tsv and Bsv groups are stable in the presence of non-nucleophilic bases and to acids. They can be removed highly effectively via a conjugate addition-elimination mechanism using pyrrolidine or sodium dodecanethiolate as nucleophiles. PMID:25162376

  13. Estimation of the Heat Capacities of Organic Liquids as a Function of Temperature using Group Additivity. I. Hydrocarbon Compounds

    NASA Astrophysics Data System (ADS)

    Růžička, Vlastimil; Domalski, Eugene S.

    1993-05-01

    A second-order group additivity method has been developed for the estimation of the heat capacity of liquid hydrocarbons as a function of temperature in the range from the melting temperature to the normal boiling temperature. The temperature dependence of group contributions and structural corrections has been represented by a polynomial expression. The adjustable parameters in the polynomials have been calculated using a weighted least squares minimization procedure. Recommended heat capacities from a large compilation of critically evaluated data that contains over 1300 organic liquids served as a database both for the development and testing of the method.

  14. Estimation of the Heat Capacities of Organic Liquids as a Function of Temperature Using Group Additivity. An Amendment

    NASA Astrophysics Data System (ADS)

    Zábranský, Milan; Růžička, Vlastimil

    2004-12-01

    An amendment to a second-order group additivity method for the estimation of the heat capacity of pure organic liquids as a function of temperature in the range from the melting temperature to the normal boiling temperature is reported. The temperature dependence of various group contributions and structural corrections is represented by a series of second order polynomial expressions. The group contribution parameters have been developed from an extended database of more than 1800 recommended heat capacity values. The present method should be more versatile and more accurate than the previous one [Růžička and Domalski, J. Phys. Chem. Ref. Data 22, 597, 619 (1993)] due to the use of a larger database and an improved procedure for parameter calculation.

  15. 8[prime]-Methylene Abscisic Acid (An Effective and Persistent Analog of Abscisic Acid).

    PubMed Central

    Abrams, S. R.; Rose, P. A.; Cutler, A. J.; Balsevich, J. J.; Lei, B.; Walker-Simmons, M. K.

    1997-01-01

    We report here the synthesis and biological activity of a new persistent abscisic acid (ABA) analog, 8[prime]-methylene ABA. This ABA analog has one additional carbon atom attached through a double bond to the 8[prime]-carbon of the ABA molecule. (+)-8[prime]-Methylene ABA is more active than the natural hormone (+)-ABA in inhibiting germination of cress seed and excised wheat embryos, in reducing growth of suspension-cultured corn cells, and in reducing transpiration in wheat seedlings. The (+)-8[prime]-methylene analog is slightly weaker than (+)-ABA in increasing expression of ABA-inducible genes in transgenic tobacco, but is equally active in stimulating a transient elevation of the pH of the medium of corn cell cultures. In corn cells, both (+)-ABA and (+)-8[prime]-methylene ABA are oxidized at the 8[prime] position. ABA is oxidized to phaseic acid and (+)-8[prime]-methylene ABA is converted more slowly to two isomeric epoxides. The alteration in the ABA structure causes the analog to be metabolized more slowly than ABA, resulting in longer-lasting and more effective biological activity relative to ABA. PMID:12223691

  16. Group additive values for the gas-phase standard enthalpy of formation, entropy and heat capacity of oxygenates.

    PubMed

    Paraskevas, Paschalis D; Sabbe, Maarten K; Reyniers, Marie-Françoise; Papayannakos, Nikos; Marin, Guy B

    2013-11-25

    A complete and consistent set of 60 Benson group additive values (GAVs) for oxygenate molecules and 97 GAVs for oxygenate radicals is provided, which allow to describe their standard enthalpies of formation, entropies and heat capacities. Approximately half of the GAVs for oxygenate molecules and the majority of the GAVs for oxygenate radicals have not been reported before. The values are derived from an extensive and accurate database of thermochemical data obtained by ab initio calculations at the CBS-QB3 level of theory for 202 molecules and 248 radicals. These compounds include saturated and unsaturated, α- and β-branched, mono- and bifunctional oxygenates. Internal rotations were accounted for by using one-dimensional hindered rotor corrections. The accuracy of the database was further improved by adding bond additive corrections to the CBS-QB3 standard enthalpies of formation. Furthermore, 14 corrections for non-nearest-neighbor interactions (NNI) were introduced for molecules and 12 for radicals. The validity of the constructed group additive model was established by comparing the predicted values with both ab initio calculated values and experimental data for oxygenates and oxygenate radicals. The group additive method predicts standard enthalpies of formation, entropies, and heat capacities with chemical accuracy, respectively, within 4 kJ mol(-1) and 4 J mol(-1) K(-1) for both ab initio calculated and experimental values. As an alternative, the hydrogen bond increment (HBI) method developed by Lay et al. (T. H. Lay, J. W. Bozzelli, A. M. Dean, E. R. Ritter, J. Phys. Chem.- 1995, 99, 14514) was used to introduce 77 new HBI structures and to calculate their thermodynamic parameters (Δ(f)H°, S°, C(p)°). The GAVs reported in this work can be reliably used for the prediction of thermochemical data for large oxygenate compounds, combining rapid prediction with wide-ranging application. PMID:24123572

  17. Mono- and dicationic short PEG and methylene dioxyalkylglycerols for use in synthetic gene delivery systems.

    PubMed

    Hurley, Christopher A; Wong, John B; Ho, Jimmy; Writer, Michele; Irvine, Scott A; Lawrence, M Jayne; Hart, Stephen L; Tabor, Alethea B; Hailes, Helen C

    2008-07-21

    A range of monocationic and dicationic dioxyalkylglycerol cytofectins have been synthesised possessing methylene and short n-ethylene glycol spacers. The monocationic compounds were found to be effective in transfections when formulated as lipopolyplexes with peptide and DNA components, in particular with shorter PEG head groups which may have less effect on peptide targeting in the ternary complex. PMID:18600277

  18. Featured Molecules: Ascorbic Acid and Methylene Blue

    NASA Astrophysics Data System (ADS)

    Coleman, William F.; Wildman, Randall J.

    2003-05-01

    The WebWare molecules of the month for May are featured in several articles in this issue. "Arsenic: Not So Evil After All?" discusses the pharmaceutical uses of methylene blue and its development as the first synthetic drug used against a specific disease. The JCE Classroom Activity "Out of the Blue" and the article "Greening the Blue Bottle" feature methylene blue and ascorbic acid as two key ingredients in the formulation of the blue bottle. You can also see a colorful example of these two molecules in action on the cover. "Sailing on the 'C': A Vitamin Titration with a Twist" describes an experiment to determine the vitamin C (ascorbic acid) content of citrus fruits and challenges students, as eighteenth-century sea captains, to decide the best fruit to take on a long voyage. Fully manipulable (Chime) versions of these and other molecules are available at Only@JCE Online.

  19. First principles based group additive values for the gas phase standard entropy and heat capacity of hydrocarbons and hydrocarbon radicals.

    PubMed

    Sabbe, Maarten K; De Vleeschouwer, Freija; Reyniers, Marie-Françoise; Waroquier, Michel; Marin, Guy B

    2008-11-27

    In this work a complete and consistent set of 95 Benson group additive values (GAVs) for standard entropies S(o) and heat capacities C(p)(o) of hydrocarbons and hydrocarbon radicals is presented. These GAVs include 46 groups, among which 25 radical groups, which, to the best of our knowledge, have not been reported before. The GAVs have been determined from a set of B3LYP/6-311G(d,p) ideal gas statistical thermodynamics values for 265 species, consistently with previously reported GAVs for standard enthalpies of formation. One-dimensional hindered rotor corrections for all internal rotations are included. The computational methodology has been compared to experimental entropies (298 K) for 39 species, with a mean absolute deviation (MAD) between experiment and calculation of 1.2 J mol(-1) K(-1), and to 46 experimental heat capacities (298 K) with a resulting MAD = 1.8 J mol(-1) K(-1). The constructed database allowed evaluation of corrections on S(o) and C(p)(o) for non-nearest-neighbor effects, which have not been determined previously. The group additive model predicts the S(o) and C(p)(o) within approximately 5 J mol(-1) K(-1) of the ab initio values for 11 of the 14 molecules of the test set, corresponding to an acceptable maximal deviation of a factor of 1.6 on the equilibrium coefficient. The obtained GAVs can be applied for the prediction of S(o) and C(p)(o) for a wide range of hydrocarbons and hydrocarbon radicals. The constructed database also allowed determination of a large set of hydrogen bond increments, which can be useful for the prediction of radical thermochemistry. PMID:18980365

  20. Selectivity in the Addition Reactions of Organometallic Reagents to Aziridine-2-carboxaldehydes: The Effects of Protecting Groups and Substitution Patterns

    PubMed Central

    Kulshrestha, Aman; Schomaker, Jennifer M.; Holmes, Daniel; Staples, Richard J.; Jackson, James E.; Borhan, Babak

    2014-01-01

    Good to excellent stereo-selectivity has been found in the addition reactions of Grignard and organo-zinc reagents to N-protected aziridine-2-carboxaldehydes. Specifically, high syn selectivity was obtained with benzyl-protected cis, tert-butyloxycar-bonyl-protected trans, and tosyl-pro-tected 2,3-disubstituted aziridine-2-car-boxaldehydes. Furthermore, rate and selectivity effects of ring substituents, temperature, solvent, and Lewis acid and base modifiers were studied. The diastereomeric preference of addition is dominated by the substrate aziri-dines’ substitution pattern and especially the electronic character and conformational preferences of the nitrogen protecting groups. To help rationalize the observed stereochemical outcomes, conformational and electronic structural analyses of a series of model systems representing the various substitution patterns have been explored by density functional calculations at the B3LYP/6–31G* level of theory with the SM8 solvation model to account for solvent effects. PMID:21928447

  1. 21 CFR 177.1660 - Poly (tetra-methylene tereph-thalate).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Poly (tetra-methylene tereph-thalate). 177.1660 Section 177.1660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated...

  2. Oxidative addition of group 13 and 14 metal halides and Alkyls to Ga(DDP) (DDP = bulky bisimidinate).

    PubMed

    Kempter, Andreas; Gemel, Christian; Fischer, Roland A

    2008-08-18

    The oxidative addition of a variety of group 13 and group 14 halides and alkyls R aMX to the mono valent group 13 bis-imidinate Ga(DDP) (DDP = 2-{(2,6-diisopropyl-phenyl)amino}-4-{(2,6-diisopropylphenyl)imino}-2-pentene) is reported. Accordingly, the insertion of Ga(DDP) into the Ga-Me bond of GaMe 3 yield in the complexes [{(DDP)GaMe}GaMe 2] ( 1) and [{(DDP)GaMe} 2GaMe] ( 2), respectively, which show a temperature-dependent equilibrium between 1 at higher temperatures and 2 at lower temperatures. In the case of GaCl 3, the only isolable product is [{(DDP)GaCl} 2GaCl] ( 3). The related reaction of SnMe 2Cl 2 with Ga(DDP) yields the compound [Me 2Sn{ClGa(DDP)} 2] ( 4), whereas SnMe 4 behaves inert. In the case of SiCl 4, only the monoinsertion product [Cl 3Si{ClGa(DDP)}] ( 5) was observed. Finally, [(CH 3) 3C{ClGa(DDP)}] ( 6) is synthesized by insertion of Ga(DDP) into the C-Cl bond of ClC(CH 3) 3. All new compounds were fully characterized by elemental analysis, NMR-spectroscopy, and single-crystal X-ray diffraction analysis. PMID:18630902

  3. The Use of Nominal Group Technique to Determine Additional Support Needs for a Group of Victorian TAFE Managers and Senior Educators

    ERIC Educational Resources Information Center

    Bailey, Anthony

    2013-01-01

    The nominal group technique (NGT) is a structured process to gather information from a group. The technique was first described in 1975 and has since become a widely-used standard to facilitate working groups. The NGT is effective for generating large numbers of creative new ideas and for group priority setting. This paper describes the process of…

  4. Methylene blue mediated laser therapy of maxillary sinusitis

    NASA Astrophysics Data System (ADS)

    Genina, E. A.; Bashkatov, A. N.; Chikina, E. E.; Knyazev, A. B.; Mareev, O. V.; Tuchin, V. V.

    2006-07-01

    The purpose of the present work is a clinical study of photodynamic therapy of maxillary sinusitis. 0.1%-Methylene Blue aqueous solution in combination with He-Ne laser irradiation (632.8 nm) have been used for treatment of maxillary sinus mucous of patients with acute and chronic maxillary sinusitis. The differences between the results of the treatment with dye and light versus treatment with a drug for every group of patients were statistically analyzed by Student’s t test. The efficacy of the photodynamic therapy was estimated with the use of the following criteria: the state of respiration, olfaction, duration of purulent discharge, reconstruction of transport function of ciliary epithelium, etc. The obtained results have shown that the photodynamic therapy is effective in comparison with conservative methods of treatment of the disease.

  5. A porous metal-organic framework with -COOH groups for highly efficient pollutant removal.

    PubMed

    Zhang, Qi; Yu, Jiancan; Cai, Jianfeng; Song, Ruijing; Cui, Yuanjing; Yang, Yu; Chen, Banglin; Qian, Guodong

    2014-11-28

    A new metal-organic framework with -COOH groups has been realized and demonstrates strong interactions with methylene blue and thus the complete removal of methylene blue from aqueous solution. PMID:25303384

  6. Joint interaction of ethidium bromide and methylene blue with DNA. The effect of ionic strength on binding thermodynamic parameters.

    PubMed

    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. PMID:26239502

  7. Photo-degradation of methylene blue using Ta-doped ZnO nanoparticle

    SciTech Connect

    Kong Jizhou; Li Aidong; Li Xiangyu; Zhai Haifa; Zhang Wenqi; Gong Youpin; Li Hui; Wu Di

    2010-06-15

    A photocatalyst of Ta-doped ZnO was prepared by a modified Pechini-type method. The structural, morphological properties and photocatalytic activity of 1 mol % Ta-doped ZnO samples annealed at different temperatures were characterized. The photo-oxidation of methylene blue under the visible-light irradiation followed the pseudo-first-order kinetics according to the Langmuir-Hinshelwood model. It is found that the photocatalysis of 1% Ta-doped ZnO annealed at 700 {sup o}C showed excellent performance of the photodegradation of methylene blue, which was attributed to a competitive trade-off among the crystallinity, surface hydroxyl groups, and specific surface area. The processing parameter such as the pH value also played an important role in tuning the photocatalytic activity. The maximum photodecomposed rate was achieved at pH=8, and an novel model about the absorption of methylene blue on the surface of the catalysts was proposed. - Graphical abstract: This model describes the adsorption between the amphoteric behavior of the metal oxide and the cationic dye methylene blue (MB) on the surface of the catalyst at the acidic and alkaline condition.

  8. Separating the effects of shelter from additional cage enhancements for group-housed BALB/cJ mice.

    PubMed

    Swetter, Brentt J; Karpiak, Christie P; Cannon, J Timothy

    2011-05-20

    Enrichment studies with rodents have demonstrated that cage enhancements can improve animal welfare and performance on common behavioral measures, but few studies have compared more than one type of enrichment or controlled for confounds, and some have revealed undesirable effects including increased aggression. We compared effects on male (n=51) and female (n=52) BALB/cJ mice of three common additions to a standard home cage: shelter, shelter+running wheel, and shelter+novel objects. Mice in all conditions lived in standard sized cages with 3-4 mice per cage. Males evidenced significant condition effects. Shelter increased longevity and maintained low levels of aggression. Adding a running wheel increased aggression over shelter alone, changed behavior in the elevated plus (EP) and open field (OF), and maintained the improved longevity seen in all shelter conditions. Novel objects impacted behavioral measures compared to the standard condition. An Igloo shelter without running wheel creates a very different home cage environment than the same shelter with the running wheel attached. Shelter, with positive impact on animal welfare, minimal effects on some common behavioral measures, and some positive effects on test variance, warrants consideration for routine inclusion with group-housed BALB/cJ males. PMID:21457758

  9. An investigation of nonchlorinated substitute cleaning agents for methylene chloride

    SciTech Connect

    Salerno, R.F.; Dichiaro, J.V.; Egleston, E.E.; Koons, J.W.

    1990-01-29

    Four nonchlorinated solvents, N-methylpyrrolidinone (NMP), arco solv DPM, Bio Act EC-7, and ethyl lactate, were evaluated as substitutes for the methylene chloride used as a cleaning solvent in a ceramic component production process. NMP showed a cleaning efficiency that was superior to the other nonchlorinated solvents and to methylene chloride. 6 figs., 2 tabs.

  10. The Additive Impact of Group and Individual Publicly Displayed Feedback: Examining Individual Response Patterns and Response Generalization in a Safe-Driving Occupational Intervention

    ERIC Educational Resources Information Center

    Ludwig, Timothy D.; Geller, E. Scott; Clarke, Steven W.

    2010-01-01

    Additive effects of publicly posting individual feedback following group goal-setting and feedback were evaluated. The turn-signal use of pizza deliverers was studied in a multiple baseline design across two pizza stores. After baseline observations, pizza deliverers voted on a group turn-signal goal and then received 4 weeks of group feedback on…

  11. Solvent mimicry with methylene carbene to probe protein topography.

    PubMed

    Gómez, Gabriela Elena; Monti, José Luis E; Mundo, Mariana Rocío; Delfino, José María

    2015-10-01

    The solvent accessible surface area (SASA) of the polypeptide chain plays a key role in protein folding, conformational change, and interaction. This fundamental biophysical parameter is elusive in experimental measurement. Our approach to this problem relies on the reaction of the minimal photochemical reagent diazirine (DZN) with polypeptides. This reagent (i) exerts solvent mimicry because its size is comparable to water and (ii) shows scant chemical selectivity because it generates extremely reactive methylene carbene. Methylation gives rise to the EM (extent of modification) signal, which is useful for scrutinizing the conformational change triggered by Ca(2+) binding to calmodulin (CaM). The increased EM observed for the full protein is dominated by the enhanced exposure of hydrophobic area in Ca(2+)-CaM. Fragmentation allowed us to quantify the methylene incorporation at specific sites. Peptide 91-106 reveals a major reorganization around the calcium 151 binding site, resulting in local ordering and a greater exposure of the hydrophobic surface. Additionally, this technique shows a high sensitivity to probe recognition between CaM and melittin (Mel). The large decrease in EM indicates the occlusion of a significant hydrophobic area upon complexation. Protection from labeling reveals a larger involvement of the N-terminal and central regions of CaM in this interaction. Despite its smaller size, Mel's differential exposure can also be quantified. Moreover, MS/MS fragmentation realizes the goal of extending the resolution of labeled sites at the amino acid level. Overall, DZN labeling emerges as a useful footprinting method capable of shedding light on physiological conformational changes and interactions. PMID:26348271

  12. Synthesis of symmetrical methylene-bridged imidazoheterocycles using DMSO as methylene source under metal-free conditions.

    PubMed

    Liu, Ping; Shen, Ziyan; Yuan, Yao; Sun, Peipei

    2016-07-01

    A facile H3PO4-promoted bridging methylenation of imidazopyridines or similar heterocycles has been described for the synthesis of symmetrical methylene-bridged imidazoheterocycles, in which DMSO was used as the carbon source. The reaction obtained good yields for most substrates with high C3-regioselectivity. This method also features metal-free, practicability and low cost. PMID:27298191

  13. Adiabatic state preparation study of methylene

    SciTech Connect

    Veis, Libor Pittner, Jiří

    2014-06-07

    Quantum computers attract much attention as they promise to outperform their classical counterparts in solving certain type of problems. One of them with practical applications in quantum chemistry is simulation of complex quantum systems. An essential ingredient of efficient quantum simulation algorithms are initial guesses of the exact wave functions with high enough fidelity. As was proposed in Aspuru-Guzik et al. [Science 309, 1704 (2005)], the exact ground states can in principle be prepared by the adiabatic state preparation method. Here, we apply this approach to preparation of the lowest lying multireference singlet electronic state of methylene and numerically investigate preparation of this state at different molecular geometries. We then propose modifications that lead to speeding up the preparation process. Finally, we decompose the minimal adiabatic state preparation employing the direct mapping in terms of two-qubit interactions.

  14. Modified pineapple peel cellulose hydrogels embedded with sepia ink for effective removal of methylene blue.

    PubMed

    Dai, Hongjie; Huang, Huihua

    2016-09-01

    Novel composite hydrogels based on pineapple peel cellulose and sepia ink were synthesized by homogeneous acetylation of cellulose in ionic liquid 1-butyl-3-methylimidazolium chloride. The structure and morphology of the prepared hydrogels were characterized by Fourier transform infrared spectroscopy, field emission scanning electron microscope, X-ray diffraction, thermogravimetry and differential scanning calorimetry. The effects of acetylation time, acetylation temperature, molar ratio of acetic anhydride/anhydroglucose unit and the additive amount of sepia ink on methylene blue adsorption capacity of the hydrogels embedded with sepia ink were also investigated. Methylene blue adsorption of the hydrogels followed pseudo-second-order kinetic model and sepia ink improved adsorption capacity significantly. The adsorption capacity at equilibrium was increased from 53.72 to 138.25mg/g when the additive amount of sepia ink of the hydrogels was 10%. PMID:27185109

  15. The preparation of novel adsorbent materials with efficient adsorption performance for both chromium and methylene blue.

    PubMed

    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. PMID:26859116

  16. Polar Addition to C=C Group: Why Is Anti-Markovnikov Hydroboration-Oxidation of Alkenes Not "Anti-"?

    ERIC Educational Resources Information Center

    Ilich, Predrag-Peter; Rickertsen, Lucas S.; Becker, Erienne

    2006-01-01

    For 137 years Markovnikov's rule has been extensively used in organic chemical education and research to describe the regioselectivity in electrophilic addition reactions to alkenes and alkynes. When the structures of the final reaction products are used as reference, the rule requests that certain polar addition reactions be termed…

  17. Methylene Blue Is Neuroprotective against Mild Traumatic Brain Injury

    PubMed Central

    Long, Justin Alexander; Chemello, Jonathan; Van Koughnet, Samantha; Fernandez, Angelica; Huang, Shiliang; Shen, Qiang

    2014-01-01

    Abstract Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. Methylene blue (MB) has known energy-enhancing and antioxidant properties. This study tested the hypothesis that MB treatment reduces lesion volume and behavioral deficits in a rat model of mild TBI. In a randomized double-blinded design, animals received either MB (n=5) or vehicle (n=6) after TBI. Studies were performed on 0, 1, 2, 7, and 14 days following an impact to the primary forelimb somatosensory cortex. MRI lesion was not apparent 1 h after TBI, became apparent 3 h after TBI, and peaked at 2 days for both groups. The MB-treated animals showed significantly smaller MRI lesion volume than the vehicle-treated animals at all time points studied. The MB-treated animals exhibited significantly improved scores on forelimb placement asymmetry and foot fault tests than did the vehicle-treated animals at all time points studied. Smaller numbers of dark-stained Nissl cells and Fluoro-Jade® positive cells were observed in the MB-treated group than in vehicle-treated animals 14 days post-TBI. In conclusion, MB treatment minimized lesion volume, behavioral deficits, and neuronal degeneration following mild TBI. MB is already approved by the United States Food and Drug Administration (FDA) to treat a number of indications, likely expediting future clinical trials in TBI. PMID:24479842

  18. Stereoselective synthesis of tricyclic compounds by intramolecular palladium-catalyzed addition of aryl iodides to carbonyl groups.

    PubMed

    Saadi, Jakub; Bentz, Christoph; Redies, Kai; Lentz, Dieter; Zimmer, Reinhold; Reissig, Hans-Ulrich

    2016-01-01

    Starting from γ-ketoesters with an o-iodobenzyl group we studied a palladium-catalyzed cyclization process that stereoselectively led to bi- and tricyclic compounds in moderate to excellent yields. Four X-ray crystal structure analyses unequivocally defined the structure of crucial cyclization products. The relative configuration of the precursor compounds is essentially transferred to that of the products and the formed hydroxy group in the newly generated cyclohexane ring is consistently in trans-arrangement with respect to the methoxycarbonyl group. A transition-state model is proposed to explain the observed stereochemical outcome. This palladium-catalyzed Barbier-type reaction requires a reduction of palladium(II) back to palladium(0) which is apparently achieved by the present triethylamine. PMID:27559374

  19. Stereoselective synthesis of tricyclic compounds by intramolecular palladium-catalyzed addition of aryl iodides to carbonyl groups

    PubMed Central

    Saadi, Jakub; Bentz, Christoph; Redies, Kai; Lentz, Dieter; Zimmer, Reinhold

    2016-01-01

    Summary Starting from γ-ketoesters with an o-iodobenzyl group we studied a palladium-catalyzed cyclization process that stereoselectively led to bi- and tricyclic compounds in moderate to excellent yields. Four X-ray crystal structure analyses unequivocally defined the structure of crucial cyclization products. The relative configuration of the precursor compounds is essentially transferred to that of the products and the formed hydroxy group in the newly generated cyclohexane ring is consistently in trans-arrangement with respect to the methoxycarbonyl group. A transition-state model is proposed to explain the observed stereochemical outcome. This palladium-catalyzed Barbier-type reaction requires a reduction of palladium(II) back to palladium(0) which is apparently achieved by the present triethylamine. PMID:27559374

  20. Spectroscopy of Methylene Blue-Smectite Suspensions.

    PubMed

    Jacobs; Schoonheydt

    1999-12-01

    Aqueoussuspensions of different Na-smectite type clay minerals were exchanged with methylene blue (Mb) and analyzed by visible spectroscopy. The spectra show bands of two types of monomers, protonated Mb, Mb-dimers, and higher aggregates. Their relative importance and the bandwidth was found to depend on parameters such as the particle morphology, the degree of dispersion, and the extent and location of the layer charge of the smectite. This can be qualitatively explained by the relative importance of three types of interactions, Mb-surface, H(2)O-surface, and Mb-Mb interactions. For hectorite and laponite at small loadings, H(2)O-surface interactions are dominant. Mb-islands are formed with a characteristic monomer absorption at 653 nm. Monomers at the surface absorb at 670 nm as found in barasym and saponite. Wyoming bentonite takes an intermediate position. As the loading increases Mb-Mb and Mb-surface interactions become dominant, giving rise to monomers absorbing at 670 nm, dimers, and higher aggregates. The bandwidths of the absorption bands reflect the structure of the clay particle associates. Copyright 1999 Academic Press. PMID:10550246

  1. SU-E-I-64: Transverse Relaxation Time in Methylene Protons of Non-Alcoholic Fatty Liver Disease Rats

    SciTech Connect

    Song, K-H; Lee, D-W; Choe, B-Y

    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)

  2. Cytological and Molecular Characterization of Homoeologous Group-1 Chromosomes in Hybrid Derivatives of a Durum Disomic Alien Addition Line

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight (FHB) is a devastating disease of durum wheat (Triticum turgidum L., 2n = 4x = 28; AABB). To incorporate FHB resistance from diploid wheatgrass (Lophopyrum elongatum (Host) Á. Löve, 2n = 2x = 14; EE) we produced earlier a stable alien disomic addition line, DGE-1, incorporating...

  3. Methylene blue treatment in experimental ischemic stroke: a mini review

    PubMed Central

    Jiang, Zhao; Duong, Timothy Q

    2016-01-01

    Stroke is a leading cause of death and long-term disability. Methylene blue, a drug grandfathered by the Food and Drug Administration with a long history of safe usage in humans for treating methemoglobinemia and cyanide poisoning, has recently been shown to be neuroprotective in neurodegenerative diseases and brain injuries. The goal of this paper is to review studies on methylene blue in experimental stroke models. PMID:27042692

  4. Fate and effects of methylene chloride in activated sludge.

    PubMed

    Klecka, G M

    1982-09-01

    Activated sludge obtained from a municipal wastewater treatment plant was acclimated to methylene chloride at concentrations between 1 and 100 mg/liter by continuous exposure to the compound for 9 to 11 days. Acclimated cultures were shown to mineralize methylene chloride to carbon dioxide and chloride. Rates of methylene chloride degradation were 0.14, 2.3, and 7.4 mg of CH2Cl2 consumed per h per g of mixed-liquor suspended solids for cultures incubated in the presence of 1, 10, and 100 mg/liter, respectively. Concentrations of methylene chloride between 10 and 1,000 mg/liter had no significant effect on O2 consumption or glucose metabolism by activated sludge. A hypothetical model was developed to examine the significance of volatilization and biodegradation for the removal of methylene chloride from an activated sludge reactor. Application of the model indicated that the rate of biodegradation was approximately 12 times greater than the rate of volatilization. Thus, biodegradation may be the predominant process determining the fate of methylene chloride in activated sludge systems continuously exposed to the compound. PMID:7138008

  5. Fate and effects of methylene chloride in activated sludge.

    PubMed Central

    Klecka, G M

    1982-01-01

    Activated sludge obtained from a municipal wastewater treatment plant was acclimated to methylene chloride at concentrations between 1 and 100 mg/liter by continuous exposure to the compound for 9 to 11 days. Acclimated cultures were shown to mineralize methylene chloride to carbon dioxide and chloride. Rates of methylene chloride degradation were 0.14, 2.3, and 7.4 mg of CH2Cl2 consumed per h per g of mixed-liquor suspended solids for cultures incubated in the presence of 1, 10, and 100 mg/liter, respectively. Concentrations of methylene chloride between 10 and 1,000 mg/liter had no significant effect on O2 consumption or glucose metabolism by activated sludge. A hypothetical model was developed to examine the significance of volatilization and biodegradation for the removal of methylene chloride from an activated sludge reactor. Application of the model indicated that the rate of biodegradation was approximately 12 times greater than the rate of volatilization. Thus, biodegradation may be the predominant process determining the fate of methylene chloride in activated sludge systems continuously exposed to the compound. PMID:7138008

  6. The Addition of A Pregnenolone Pendant Group Enhances the Anticancer Properties of Titanocene Dichloride in a MCF-7 Xenograft Model

    PubMed Central

    Ramos, Gladiany; Loperena, Yaliz; Ortiz, Giovanni; Reyes, Fiorella; Szeto, Ada; Vera, Jose; Velez, Javier; Morales, Jessica; Morrero, Deborah; Castillo, Linnette; Dharmawardhane, Surangani; Melendez, Enrique; Washington, A. Valance

    2014-01-01

    Background/Aim Titanocene dichloride held great promise as a chemotherapeutic compound in preclinical studies. However, subsequent clinical trials revealed hepatoxicity and nephrotoxicity, which limited its use in clinical applications. Therefore, we used steroid pendant groups to improve the targeting of titanocene in the MCF-7 breast cancer cell line, and demonstrated a 10-fold lower effective dose compared to titanocene in in vitro assays. The aim of the present study was to test the efficacy of a titanocene functionalized with pregnenolone (Ti-Preg) in an in vivo breast cancer model. Materials and Methods Xenografts from the MCF7 breast cancer cell line were implanted into athymic nu/nu mice to evaluate the potential of Ti-Preg as an anti-breast cancer agent. Results Ti-Preg demonstrated a significant inhibition of MCF-7 tumor growth when compared to vehicle and to titanocene controls. Conclusion Our findings demonstrate the potential of steroid pendent groups for targeting chemotherapeutics to steroid hormone-dependent cancer. PMID:24692689

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

    PubMed

    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. PMID:26663466

  8. Attenuation of noise-induced hearing loss using methylene blue

    PubMed Central

    Park, J-S; Jou, I; Park, S M

    2014-01-01

    The overproduction of reactive oxygen species (ROS) and reactive nitrogen species (RNS) has been known to contribute to the pathogenesis of noise-induced hearing loss. In this study, we discovered that in BALB/c mice pretreatment with methylene blue (MB) for 4 consecutive days significantly protected against cochlear injury by intense broad-band noise for 3 h. It decreased both compound threshold shift and permanent threshold shift and, further, reduced outer hair cell death in the cochlea. MB also reduced ROS and RNS formation after noise exposure. Furthermore, it protected against rotenone- and antimycin A-induced cell death and also reversed ATP generation in the in vitro UB-OC1 cell system. Likewise, MB effectively attenuated the noise-induced impairment of complex IV activity in the cochlea. In addition, it increased the neurotrophin-3 (NT-3) level, which could affect the synaptic connections between hair cells and spiral ganglion neurons in the noise-exposed cochlea, and also promoted the conservation of both efferent and afferent nerve terminals on the outer and inner hair cells. These findings suggest that the amelioration of impaired mitochondrial electron transport and the potentiation of NT-3 expression by treatment with MB have a significant therapeutic value in preventing ROS-mediated sensorineural hearing loss. PMID:24763057

  9. Functional inactivation of lymphocytes by methylene blue with visible light.

    PubMed

    Zhang, Bo; Cheng, Zhenzhen; Mo, Qin; Wang, Li; Wang, Xun; Wu, Xiaofei; Jia, Yao; Huang, Yuwen

    2015-10-01

    Transfusion of allogeneic white blood cells (WBCs) may cause adverse reactions in immunocompromised recipients, including transfusion-associated graft-versus-host disease (TA-GVHD), which is often fatal and incurable. In this study, the in vitro effect of methylene blue with visible light (MB + L) treatment on lymphocyte proliferation and cytokine production was measured to investigate whether MB + L can be used to prevent immune reactions that result from transfused lymphocytes. WBCs and 3 μM of MB were mixed and transferred into medical PVC bags, which were then exposed to visible light. Gamma irradiation was conducted as a parallel positive control. The cells without treatment were used as untreated group. All the groups were tested for the ability of cell proliferation and cytokine production upon stimulation. After incubation with mitogen phytohemagglutinin (PHA) or plate-bound anti-CD3 plus anti-CD28, the proliferation of MB + L/gamma-irradiation treated lymphocytes was significantly inhibited (P < 0.01) as compared to the untreated ones; the proliferation inhibitive rate of the MB + L group was even higher than that of gamma-irradiated cells (73.77% ± 28.75% vs. 44.72% ± 38.20%). MB + L treated cells incubated up to 7 days with PHA also showed no significant proliferation. The levels of TNF-α, IFN-γ, IL-6, IL-8, IL-10 and IL-1β present in the supernatant of MB + L treated lymphocytes upon stimulation were significantly lower than those of untreated lymphocytes. These results demonstrated that MB + L treatment functionally and irreversibly inactivated lymphocytes by inhibiting lymphocyte proliferation and the production of cytokines. MB + L treatment might be a promising method for the prevention of adverse immune responses caused by WBCs. PMID:26295729

  10. Infrared spectroscopy of the methanol cation and its methylene-oxonium isomer

    SciTech Connect

    Mosley, J. D.; Young, J. W.; Duncan, M. A. E-mail: maduncan@uga.edu; Huang, M.; McCoy, A. B. E-mail: maduncan@uga.edu

    2015-03-21

    The carbenium ion with nominal formula [C,H{sub 4},O]{sup +} is produced from methanol or ethylene glycol in a pulsed-discharge supersonic expansion source. The ion is mass selected, and its infrared spectrum is measured from 2000 to 4000 cm{sup −1} using laser photodissociation spectroscopy and the method of rare gas atom tagging. Computational chemistry predicts two isomers, the methanol and methylene-oxonium cations. Predicted vibrational spectra based on scaled harmonic and reduced dimensional treatments are compared to the experimental spectra. The methanol cation is the only isomer produced when methanol is used as a precursor. When ethylene glycol is used as the precursor, methylene-oxonium is produced in addition to the methanol cation. Theoretical results at the CCSD(T)/cc-pVTZ level show that methylene-oxonium is lower in energy than methanol cation by 6.4 kcal/mol, and is in fact the global minimum isomer on the [C,H{sub 4},O]{sup +} potential surface. Methanol cation is trapped behind an isomerization barrier in our source, providing a convenient method to produce and characterize this transient species. Analysis of the spectrum of the methanol cation provides evidence for strong CH stretch vibration/torsion coupling in this molecular ion.

  11. Thermochemical Properties Enthalpy, Entropy, and Heat Capacity of C1-C4 Fluorinated Hydrocarbons: Fluorocarbon Group Additivity.

    PubMed

    Wang, Heng; Castillo, Álvaro; Bozzelli, Joseph W

    2015-07-23

    Enthalpies of formation for 14 C2–C4 fluorinated hydrocarbons were calculated with nine popular ab initio and density functional theory methods: B3LYP, CBS-QB3, CBS-APNO, M06, M06-2X, ωB97X, G4, G4(MP2)-6X, and W1U via several series of isodesmic reactions. The recommended ideal gas phase ΔHf298° (kcal mol(–1)) values calculated in this study are the following: −65.4 for CH3CH2F; −70.2 for CH3CH2CH2F; −75.3 for CH3CHFCH3; −75.2 for CH3CH2CH2CH2F; −80.3 for CH3CHFCH2CH3; −108.1 for CH2F2; −120.9 for CH3CHF2; −125.8 for CH3CH2CHF2; −133.3 for CH3CF2CH3; −166.7 for CHF3; −180.5 for CH3CF3; −185.5 for CH3CH2CF3; −223.2 for CF4; and −85.8 for (CH3)3CF. Entropies (S298° in cal mol(–1) K(–1)) were estimated using B3LYP/6-31+G(d,p) computed frequencies and geometries. Rotational barriers were determined and hindered internal rotational contributions for S298°, and Cp(T) were calculated using the rigid rotor harmonic oscillator approximation, with direct integration over energy levels of the intramolecular rotation potential energy curve. Thermochemical properties for the fluorinated carbon groups C/C/F/H2, C/C2/F/H, C/C/F2/H, C/C2/F2, and C/C/F3 were derived from the above target fluorocarbons. Previously published enthalpies and groups for 1,2-difluoroethane, 1,1,2-trifluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1,2-tetrafluoroethane, 1,1,1,2,2-pentafluoroethane, 2-fluoro-2-methylpropane that were previously determined via work reaction schemes are revised using updated reference species values. Standard deviations are compared for the calculation methods. PMID:26066097

  12. Phosphazene additives

    SciTech Connect

    Harrup, Mason K; Rollins, Harry W

    2013-11-26

    An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

  13. 46 CFR Appendix F to Subpart C of... - Optional Rider for Additional NVOCC Financial Responsibility for Group Bonds [Optional Rider to...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 9 2010-10-01 2010-10-01 false Optional Rider for Additional NVOCC Financial Responsibility for Group Bonds F Appendix F to Subpart C of Part 515 Shipping FEDERAL MARITIME COMMISSION REGULATIONS AFFECTING OCEAN SHIPPING IN FOREIGN COMMERCE LICENSING, FINANCIAL RESPONSIBILITY REQUIREMENTS, AND GENERAL DUTIES FOR OCEAN...

  14. Addition of surfactants in ozonated water cleaning for the suppression of functional group formation and particle adhesion on the SiO2 surface

    NASA Astrophysics Data System (ADS)

    Yang, Jahyun; Im, Kyungtaek; Lim, Sangwoo

    2011-04-01

    Various kinds of surfactants were added to a cleaning solution and deionized (DI) water, and their effect on the suppression of organic function group formation and particle adhesion to a SiO2 surface was analyzed using multi-internal reflection Fourier transform infrared spectroscopy. The results implied that attached organic functional groups are affected by the chemical structure of a surfactant in DI water. Furthermore, the addition of anionic glycolic acid ethoxylate 4-tert-butylphenyl ether (GAE4E) is the most effective in terms of preventing organic group attachment and particle adhesion to the SiO2 surface, whether it was added to the cleaning solution or post-cleaning rinse water, with or without polystyrene latex particles. Moreover, it was possible to completely prevent particle adhesion to the SiO2 surface with the proper addition of GAE4E in DIO3 solution.

  15. Methylene blue-related corneal edema and iris discoloration.

    PubMed

    Timucin, Ozgur Bulent; Karadag, Mehmet Fatih; Aslanci, Mehmet Emin; Baykara, Mehmet

    2016-04-01

    We report the case of a 70-year-old female patient who developed corneal edema and iris discoloration following the inadvertent use of 1% methylene blue instead of 0.025% trypan blue to stain the anterior capsule during cataract phacoemulsification surgery. Copious irrigation was performed upon realization of incorrect dye use. Corneal edema and iris discoloration developed during the early postoperative period and persisted at 24-months follow-up. However, keratoplasty was not required. The intracameral use of 1% methylene blue has a cytotoxic effect on the corneal endothelium and iris epithelium. Copious irrigation for at least 30 min using an anterior chamber maintainer may improve outcomes. PMID:27224079

  16. Adsorptive removal of methylene blue by rhamnolipid-functionalized graphene oxide from wastewater.

    PubMed

    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. PMID:25314573

  17. Chloroacetate-promoted selective oxidation of heterobenzylic methylenes under copper catalysis.

    PubMed

    Liu, Jianming; Zhang, Xin; Yi, Hong; Liu, Chao; Liu, Ren; Zhang, Heng; Zhuo, Kelei; Lei, Aiwen

    2015-01-19

    The efficient selective oxidation and functionalization of C-H bonds with molecular oxygen and a copper catalyst to prepare the corresponding ketones was achieved with ethyl chloroacetate as a promoter. In this transformation, various substituted N-heterocyclic compounds were well tolerated. Preliminary mechanistic investigations indicated that organic radical species were involved in the overall process. The N-heterocyclic compounds and ethyl chloroacetate work synergistically to activate C-H bonds in the methylene group, which results in the easy generation of free radical intermediates, thus leading to the corresponding ketones in good yields. PMID:25483218

  18. Methylene blue mediated photodynamic therapy for resistant plaque psoriasis.

    PubMed

    Salah, Manal; Samy, Nevien; Fadel, Maha

    2009-01-01

    Topical treatment of resistant psoriatic plaque stage lesions may be difficult and the systemic therapies seem inappropriate. Therefore, a topical 0.1% methylene blue (MB) hydrogel was prepared and evaluated for percent drug content, drug uniformity, pH, rheological and organoleptic characters such as feel tackiness, grittiness sensation, and transparency in addition to release kinetics study in vitro. The efficiency of the photodynamic therapy (PDT) of MB photo-activated using 565 mW Light emitting diode (LED) 670 nm was evaluated in patients with resistant plaque psoriasis. The gel was evaluated in single blinded study. The patients were subjected to repeated sessions of irradiation, skin biopsies from each patient in the beginning and at the end of the sessions were taken for histopathological studies. Results showed the hydrogel was transparent nongritty and the drug uniformly dispersed with pH=7.2 and viscosity value=25.04 Pa. The drug content was found to be 99.4 +/- 0.15 %. Drug release was following zero order kinetics with rate constant K=0.348 +/- 0.01 and T(1/2) = 0.95 +/- 0.5 hours. Sixteen patients experienced complete clearance of their treated lesions. Skin appeared normal in color, texture, and pliability with no complications indicating the lack of skin sensitivity. Histopathological examinations showed nearly normal epidermis at the end of all sessions. The authors concluded that the prepared hydrogel was safe, stable, and very effective. The results are encouraging to accept MB as a photosensitizer for PDT and as a safe and effective method for treatment of selected cases of resistant localized psoriasis PMID:19180895

  19. Synthesis and reactivity of 3-methylene-7-vinylidenebicyclo(3. 3. 1)nonane

    SciTech Connect

    Krasutskii, P.A.; Fokin, A.A.; Yurchenko, A.G.

    1986-05-10

    The synthesis of 3-methylene-7-vinylidenebicyclo(3.3.1)nonane - a new representative of pseudoconjugated allenes - was realized. In its reaction with electrophilic reagents (sulfuric acid, hydrogen chloride, bromine, and iodine) preferential cyclization to derivatives of adamantane occurs. Increase in the sulfuric acid concentration leads to the formation of 1,2-dimethylprotoadamantan-3-one - the product from more extensive rearrangement. In addition to transannular cyclization, hydrogen chloride in hexane gives rise to exo-endo isomerization of the ..pi.. bond. The differences in the regioselectivity of transannular cyclization under the influence of the acid and the halogen are discussed.

  20. Taxonomy of the hyper-diverse ant genus Tetramorium Mayr in the Malagasy region (Hymenoptera, Formicidae, Myrmicinae) – first record of the T. setigerum species group and additions to the Malagasy species groups with an updated illustrated identification key

    PubMed Central

    Hita Garcia, Francisco; Fisher, Brian L.

    2015-01-01

    Abstract In this study we provide an update to the taxonomy of the ant genus Tetramorium Mayr in Madagascar. We report the first record of the Tetramorium setigerum species group in Madagascar and describe the only Malagasy representative as Tetramorium cavernicola sp. n., which is known only from a cave in Ankarana. In addition, we provide an overview of the 19 proposed Malagasy species groups, and discuss their zoogeography and relationships to other groups and larger lineages within the hyper-diverse genus Tetramorium. At present, we recognise a highly unique Malagasy Tetramorium fauna with 113 species endemic to the island of Madagascar out of a total of 125 translating into an endemism rate of 93%. We hypothesise that this fauna is based on one or a few colonisation events from the Afrotropical region, with subsequent adaptive radiation in Madagascar. Furthermore, we present an updated and illustrated identification key to the Tetramorium species groups in the Malagasy region. PMID:26257564

  1. 4,4\\'-Methylene bis(N,N\\'-dimethyl)aniline

    Integrated Risk Information System (IRIS)

    4,4 ' - Methylene bis ( N , N ' - dimethyl ) aniline ; CASRN 101 - 61 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Haz

  2. Methylene Diphenyl Diisocyanate (monomeric MDI) and polymeric MDI (PMDI)

    Integrated Risk Information System (IRIS)

    Methylene Diphenyl Diisocyanate ( monomeric MDI ) and polymeric MDI ( PMDI ) ; CASRN 101 - 68 - 8 , 9016 - 87 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment devel

  3. Extinction Memory Improvement by the Metabolic Enhancer Methylene Blue

    ERIC Educational Resources Information Center

    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…

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

    PubMed

    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. PMID:26165999

  5. Nucleophile-catalyzed additions to activated triple bonds. Protection of lactams, imides, and nucleosides with MocVinyl and related groups.

    PubMed

    Mola, Laura; Font, Joan; Bosch, Lluís; Caner, Joaquim; Costa, Anna M; Etxebarría-Jardí, Gorka; Pineda, Oriol; de Vicente, David; Vilarrasa, Jaume

    2013-06-21

    Additions of lactams, imides, (S)-4-benzyl-1,3-oxazolidin-2-one, 2-pyridone, pyrimidine-2,4-diones (AZT derivatives), or inosines to the electron-deficient triple bonds of methyl propynoate, tert-butyl propynoate, 3-butyn-2-one, N-propynoylmorpholine, or N-methoxy-N-methylpropynamide in the presence of many potential catalysts were examined. DABCO and, second, DMAP appeared to be the best (highest reaction rates and E/Z ratios), while RuCl3, RuClCp*(PPh3)2, AuCl, AuCl(PPh3), CuI, and Cu2(OTf)2 were incapable of catalyzing such additions. The groups incorporated (for example, the 2-(methoxycarbonyl)ethenyl group that we name MocVinyl) serve as protecting groups for the above-mentioned heterocyclic CONH or CONHCO moieties. Deprotections were accomplished via exchange with good nucleophiles: the 1-dodecanethiolate anion turned out to be the most general and efficient reagent, but in some particular cases other nucleophiles also worked (e.g., MocVinyl-inosines can be cleaved with succinimide anion). Some structural and mechanistic details have been accounted for with the help of DFT and MP2 calculations. PMID:23713491

  6. Palladium-Catalyzed Asymmetric Benzylic Alkylation of Active Methylene Compounds with α-Naphthylbenzyl Carbonates and Pivalates.

    PubMed

    Tabuchi, Sho; Hirano, Koji; Miura, Masahiro

    2016-06-01

    A Pd/(R)-H8 -BINAP-catalyzed asymmetric benzylic alkylation of active methylene compounds has been developed. The reaction proceeds without the use of an external base, and the starting racemic diarylmethyl carbonates are converted into the optically active coupling products which contain the benzylic chiral stereocenter by a dynamic kinetic asymmetric transformation (DYKAT). Additionally, with suitable carbonates bases, the same palladium catalysis allows the corresponding pivalates to be adopted in the same DYKAT process. PMID:27120184

  7. Three iodometalate organic-inorganic hybrid materials based on methylene blue cation: Syntheses, structures, properties and DFT calculations

    NASA Astrophysics Data System (ADS)

    Chai, Wen-Xiang; Lin, Jian; Song, Li; Qin, Lai-Shun; Shi, Hong-Sheng; Guo, Jia-Yu; Shu, Kang-Ying

    2012-08-01

    The functional dye of methylene blue (MB) has been employed for seeking new organic-inorganic hybrid photochromic materials. Although the photochromism has not been observed yet, three iodometalate compounds, namely (MB) (PbI3) (DMF) (1), (MB)4(Cu2I4)2 (2), and (MB)3(Bi2I9) (DMF)2 (3), have been synthesized and characterized. The iodometalate anion features as a [PbI3]∞- chain in 1, a dinuclear unit of Cu2I42- in 2, and a dinuclear unit of Bi2I93- in 3. Due to the synergy of cations and anions, the MB+ cations present supramolecular column stacks in 1 and 3, but a novel supramolecular octamer structure in 2. Their thermogravimetric analyses reveal that the polymeric inorganic anion structure is helpful to increase the stability of cation whereas the discrete structure is adverse. For seeking some clues which is significant to searching new photochromic systems, the density functional theory (DFT) studies have been performed on 1, in which the electronic structure analyses suggests that the stacking mode of cations and anions could be also an important factor influencing the charge transfer between them. In addition, dielectric hysteresis loop testing has been performed on 1 due to its polar space group of Cc.

  8. Different Effect of the Additional Electron-Withdrawing Cyano Group in Different Conjugation Bridge: The Adjusted Molecular Energy Levels and Largely Improved Photovoltaic Performance.

    PubMed

    Li, Huiyang; Fang, Manman; Hou, Yingqin; Tang, Runli; Yang, Yizhou; Zhong, Cheng; Li, Qianqian; Li, Zhen

    2016-05-18

    Four organic sensitizers (LI-68-LI-71) bearing various conjugated bridges were designed and synthesized, in which the only difference between LI-68 and LI-69 (or LI-70 and LI-71) was the absence/presence of the CN group as the auxiliary electron acceptor. Interestingly, compared to the reference dye of LI-68, LI-69 bearing the additional CN group exhibited the bad performance with the decreased Jsc and Voc values. However, once one thiophene moiety near the anchor group was replaced by pyrrole with the electron-rich property, the resultant LI-71 exhibited a photoelectric conversion efficiency increase by about 3 folds from 2.75% (LI-69) to 7.95% (LI-71), displaying the synergistic effect of the two moieties (CN and pyrrole). Computational analysis disclosed that pyrrole as the auxiliary electron donor (D') in the conjugated bridge can compensate for the lower negative charge in the electron acceptor, which was caused by the CN group as the electron trap, leading to the more efficient electron injection and better photovoltaic performance. PMID:27101840

  9. Glutathione-S-transferase (GST) polymorphism among ethnic groups in Singapore with report of additional alleles at loci 1 and 2.

    PubMed

    Bhattacharyya, S P; Saha, N; Wee, K P

    1989-04-01

    Glutathione S-transferases (GST; E.C.2.5.1.18) were phenotyped by starch gel electrophoresis in post-mortem liver samples from 683 unrelated subjects of both sexes. 305 were Chinese, 185 Indians, 147 Malays and 46 from other racial groups of South-East Asia. GST1 and GST2 were found to be polymorphic in these populations. Additional alleles (GST1*3 and GST2*O) were observed at low frequency in all the ethnic groups. The frequency of GST1*1 was lower and that of GST1*2 was higher in Indians and Malays as compared to Chinese. GST1*0 and GST1*3 frequencies were similar in all these ethnic groups. The gene frequencies of the alleles of the GST2 locus varied significantly in the population studied. GST2*0 frequency was significantly higher in Indians than in Chinese and Malays, while the lowest frequency of GST2*1 was found in the Indians. GST2*2 frequency was higher in the Malays than in Chinese and Indians. GST1 and GST2 phenotype distributions were in agreement with Hardy-Weinberg equilibrium in all the ethnic groups studied. Sex made no significant difference in the phenotype distribution. PMID:2487053

  10. The role of an aromatic group in remote chiral induction during conjugate addition of α-sulfonylallylic carbanions to ethyl crotonate

    PubMed Central

    Levinger, Shlomo; Nair, Ranjeet

    2008-01-01

    Summary The impact of a remote aromatic nucleus on the stereochemical outcome of the conjugate addition of α-sulfonylallylic carbanions to an α,β-unsaturated ester was investigated. α-Regioselectivity coupled with anti-diastereoselectivity is accompanied by a prominent preference for relative configuration 3 over 4. The 9-anthryl moiety has shown itself greatly superior over all other groups in this bias. A lithium ion–aromatic π interaction has been postulated as decisive for the remote transmission of chirality. PMID:18941617

  11. Dissimilarities between methylene blue and cyanide on relaxation and cyclic GMP formation in endothelium-intact intrapulmonary artery caused by nitrogen oxide-containing vasodilators and acetylcholine

    SciTech Connect

    Ignarro, L.J.; Harbison, R.G.; Wood, K.S.; Kadowitz, P.J.

    1986-01-01

    The objective of the present study was to ascertain whether cyanide shares the properties of methylene blue as a selective inhibitor of vascular smooth muscle relaxation elicited by agents that stimulate the formation of cyclic GMP. Experiments were performed with endothelium-intact rings prepared from bovine intrapulmonary artery. Methylene blue, a good inhibitor of soluble guanylate cyclase, antagonized both arterial relaxation and cyclic GMP accumulation in response to sodium nitroprusside, glyceryl trinitrate, S-nitroso-N-acetylpenicillamine and acetylcholine. In contrast, cyanide inhibited only the responses to sodium nitroprusside. Increasing concentrations of methylene blue depressed resting arterial levels of cyclic GMP and caused slowly developing but marked contractions whereas cyanide was without effect. Contractile responses to phenylephrine, potassium and U46619 were potentiated by methylene blue but not by cyanide. Preincubation of dilute solutions of cyanide containing sodium nitroprusside in oxygenated Krebs' buffer at 37 degrees C for 15 min before addition to bath chambers depressed relaxation and cyclic GMP accumulation caused by sodium nitroprusside markedly. Similar treatment of glyceryl trinitrate, however, failed to alter its effects in arterial rings. A chemical inactivation of sodium nitroprusside by cyanide appears to account for the specific inhibitory action of cyanide on arterial responses to sodium nitroprusside. This study indicates clearly that cyanide does not share the properties of methylene blue as an inhibitor of arterial relaxation elicited by vasodilators that stimulate cyclic GMP formation.

  12. Ring closing metathesis reactions of α-methylene-β-lactams: application to the synthesis of a simplified phyllostictine analogue with herbicidal activity.

    PubMed

    Coe, Samuel; Pereira, Nicole; Geden, Joanna V; Clarkson, Guy J; Fox, David J; Napier, Richard M; Neve, Paul; Shipman, Michael

    2015-07-28

    Ring closing metathesis (RCM) reactions of α-methylene-β-lactams are used to construct strained 11- and 12-membered macrocycles that mimic key structural elements of phyllostictine A. The highest yield and stereoselectivity was achieved making 12-membered macrocycle Z-19 with use of a p-methoxyphenyl group on the lactam nitrogen. Interestingly, substrate concentration had an important influence on the stereochemical course of the reaction. A simplified analogue produced using this approach displays phytotoxic activity against Chlamydomonas reinhardtii suggesting that the α-methylene-β-lactam subunit is responsible, at least in part, for the herbicidal activity of phyllostictine A. PMID:26081012

  13. Cell-specific CO2 fixation rates of two distinct groups of plastidic protists in the Atlantic Ocean remain unchanged after nutrient addition.

    PubMed

    Grob, Carolina; Jardillier, Ludwig; Hartmann, Manuela; Ostrowski, Martin; Zubkov, Mikhail V; Scanlan, David J

    2015-04-01

    To assess the role of open-ocean ecosystems in global CO2 fixation, we investigated how picophytoplankton, which dominate primary production, responded to episodic increases in nutrient availability. Previous experiments have shown nitrogen alone, or in combination with phosphorus or iron, to be the proximate limiting nutrient(s) for total phytoplankton grown over several days. Much less is known about how nutrient upshift affects picophytoplankton CO2 fixation over the duration of the light period. To address this issue, we performed a series of small volume (8-60 ml) - short term (10-11 h) nutrient addition experiments in different regions of the Atlantic Ocean using NH4 Cl, FeCl3 , K medium, dust and nutrient-rich water from 300 m depth. We found no significant nutrient stimulation of group-specific CO2 fixation rates of two taxonomically and size-distinct groups of plastidic protists. The above was true regardless of the region sampled or nutrient added, suggesting that this is a generic phenomenon. Our findings show that at least in the short term (i.e. daylight period), nutrient availability does not limit CO2 fixation by the smallest plastidic protists, while their taxonomic composition does not determine their response to nutrient addition. PMID:25345650

  14. A multigene phylogeny of the fly superfamily Asiloidea (Insecta): Taxon sampling and additional genes reveal the sister-group to all higher flies (Cyclorrhapha).

    PubMed

    Trautwein, Michelle D; Wiegmann, Brian M; Yeates, David K

    2010-09-01

    Asiloidea are a group of 9 lower brachyceran fly families, considered to be the closest relative to the large Metazoan radiation Eremoneura (Cyclorrhapha+Empidoidea). The evidence for asiloid monophyly is limited, and few characters define the relationships between the families of Asiloidea and Eremoneura. Additionally, enigmatic genera, Hilarimorpha and Apystomyia, retain morphological characters of both asiloids and higher flies. We use the nuclear protein-coding gene CAD and 28S rDNA to test the monophyly of Asiloidea and to resolve its relationship to Eremoneura. We explore the effects of taxon sampling on support values and topological stability, the resolving power of additional genes, and hypothesis testing using four-cluster likelihood mapping. We find that: (1) the 'asiloid' genus Apystomyia is sister to Cyclorrhapha, (2) the remaining asiloids are monophyletic at the exclusion of the family Bombyliidae, and (3) our best estimate of relationships places the asiloid flies excluding Bombyliidae as the sister-group to Eremoneura, though high support is lacking. PMID:20399874

  15. Quantifying Additive Interactions of the Osmolyte Proline with Individual Functional Groups of Proteins: Comparisons with Urea and Glycine Betaine, Interpretation of m-Values

    PubMed Central

    Diehl, Roger C.; Guinn, Emily J.; Capp, Michael W.; Tsodikov, Oleg V.; Record, M. Thomas

    2013-01-01

    To quantify interactions of the osmolyte L-proline with protein functional groups and predict its effects on protein processes, we use vapor pressure osmometry to determine chemical potential derivatives dµ2/dm3 = µ23 quantifying preferential interactions of proline (component 3) with 21 solutes (component 2) selected to display different combinations of aliphatic or aromatic C, amide, carboxylate, phosphate or hydroxyl O, and/or amide or cationic N surface. Solubility data yield µ23 values for 4 less-soluble solutes. Values of µ23 are dissected using an ASA-based analysis to test the hypothesis of additivity and obtain α-values (proline interaction potentials) for these eight surface types and three inorganic ions. Values of µ23 predicted from these α-values agree with experiment, demonstrating additivity. Molecular interpretation of α-values using the solute partitioning model yields partition coefficients (Kp) quantifying the local accumulation or exclusion of proline in the hydration water of each functional group. Interactions of proline with native protein surface and effects of proline on protein unfolding are predicted from α-values and ASA information and compared with experimental data, with results for glycine betaine and urea, and with predictions from transfer free energy analysis. We conclude that proline stabilizes proteins because of its unfavorable interactions with (exclusion from) amide oxygens and aliphatic hydrocarbon surface exposed in unfolding, and that proline is an effective in vivo osmolyte because of the osmolality increase resulting from its unfavorable interactions with anionic (carboxylate and phosphate) and amide oxygens and aliphatic hydrocarbon groups on the surface of cytoplasmic proteins and nucleic acids. PMID:23909383

  16. Seed colour loci, homoeology and linkage groups of the C genome chromosomes revealed in Brassica rapa–B. oleracea monosomic alien addition lines

    PubMed Central

    Heneen, Waheeb K.; Geleta, Mulatu; Brismar, Kerstin; Xiong, Zhiyong; Pires, J. Chris; Hasterok, Robert; Stoute, Andrew I.; Scott, Roderick J.; King, Graham J.; Kurup, Smita

    2012-01-01

    Background and Aims Brassica rapa and B. oleracea are the progenitors of oilseed rape B. napus. The addition of each chromosome of B. oleracea to the chromosome complement of B. rapa results in a series of monosomic alien addition lines (MAALs). Analysis of MAALs determines which B. oleracea chromosomes carry genes controlling specific phenotypic traits, such as seed colour. Yellow-seeded oilseed rape is a desirable breeding goal both for food and livestock feed end-uses that relate to oil, protein and fibre contents. The aims of this study included developing a missing MAAL to complement an available series, for studies on seed colour control, chromosome homoeology and assignment of linkage groups to B. oleracea chromosomes. Methods A new batch of B. rapa–B. oleracea aneuploids was produced to generate the missing MAAL. Seed colour and other plant morphological features relevant to differentiation of MAALs were recorded. For chromosome characterization, Snow's carmine, fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH) were used. Key Results The final MAAL was developed. Morphological traits that differentiated the MAALs comprised cotyledon number, leaf morphology, flower colour and seed colour. Seed colour was controlled by major genes on two B. oleracea chromosomes and minor genes on five other chromosomes of this species. Homoeologous pairing was largely between chromosomes with similar centromeric positions. FISH, GISH and a parallel microsatellite marker analysis defined the chromosomes in terms of their linkage groups. Conclusions A complete set of MAALs is now available for genetic, genomic, evolutionary and breeding perspectives. Defining chromosomes that carry specific genes, physical localization of DNA markers and access to established genetic linkage maps contribute to the integration of these approaches, manifested in the confirmed correspondence of linkage groups with specific chromosomes. Applications include marker

  17. Dermal and inhalation exposure to methylene bisphenyl isocyanate (MDI) in iron foundry workers.

    PubMed

    Liljelind, I; Norberg, C; Egelrud, L; Westberg, H; Eriksson, K; Nylander-French, L A

    2010-01-01

    Diisocyanates are a group of chemically reactive agents, which are used in the production of coatings, adhesives, polyurethane foams, and parts for the automotive industry and as curing agents for cores in the foundry industry. Dermal and inhalation exposure to methylene bisphenyl isocyanate (MDI) is associated with respiratory sensitization and occupational asthma. However, limited research has been performed on the quantitative evaluation of dermal and inhalation exposure to MDI in occupationally exposed workers. The objective of this research was to quantify dermal and inhalation exposure levels in iron foundry workers. Workers involved in mechanized moulding and mechanized production of cores were monitored: 12 core makers, 2 core-sand preparers, and 5 core installers. Personal breathing-zone levels of MDI were measured using impregnated filter sampling. Dermal exposure to MDI was measured using a tape-strip technique. Three or five consecutive tape-strip samples were collected from five exposed skin areas (right and left forefingers, left and right wrists, and forehead). The average personal air concentration was 0.55 microg m(-3), 50-fold lower than the Swedish occupational exposure limit of 30 microg m(-3). The core makers had an average exposure of 0.77 microg m(-3), which was not significantly different from core installers' and core-sand preparers' average exposure of 0.16 microg m(-3) (P = 0.059). Three core makers had a 10-fold higher inhalation exposure than the other core makers. The core makers' mean dermal exposure at different skin sites varied from 0.13 to 0.34 microg while the two other groups' exposure ranged from 0.006 to 0.062 microg. No significant difference was observed in the MDI levels between the skin sites in a pairwise comparison, except for left forefinger compared to left and right wrist (P < 0.05). In addition, quantifiable but decreasing levels of MDI were observed in the consecutive tape strip per site indicating MDI penetration

  18. The interaction between methylene blue and the cholinergic system

    PubMed Central

    Pfaffendorf, M; Bruning, T A; Batink, H D; van Zwieten, P A

    1997-01-01

    The inhibitory effects of methylene blue (MB) on different types of cholinesterases and [3H]-N-methylscopolamine ([3H]-NMS) binding to muscarinic receptors were studied. Human plasma from young healthy male volunteers, purified human pseudocholinesterase and purified bovine true acetylcholinesterase were incubated with acetylcholine and increasing concentrations of MB (0.1–100 μmol l−1) in the presence of the pH-indicator m-nitrophenol for 30 min at 25°C. The amount of acetic acid produced by the enzymatic hydrolysis of acetylcholine was determined photometrically. Rat cardiac left ventricle homogenate was incubated with [3H]-NMS and with increasing concentrations of MB (0.1 nmol l−1–100 μmol l−1) at 37°C for 20 min. The binding of [3H]-NMS to the homogenate was quantified by a standard liquid scintillation technique. MB inhibited the esterase activity of human plasma, human pseudocholinesterase and bovine acetylcholinesterase concentration-dependently with IC50 values of 1.05±0.05 μmol l−1, 5.32±0.36 μmol l−1 and 0.42±0.09 μmol l−1, respectively. MB induced complete inhibition of the esterase activity of human plasma and human pseudocholinesterase, whereas bovine acetylcholinesterase was maximally inhibited by 73±3.3%. MB was able to inhibit specific [3H]-NMS binding to rat cardiac left ventricle homogenate completely with an IC50 value of 0.77±0.03 μmol l−1, which resulted in a Ki value for MB of 0.58±0.02 μmol l−1. In conclusion, MB may be considered as a cholinesterase inhibitor with additional, relevant affinity for muscarinic binding sites at concentrations at which MB is used for investigations into the endothelial system. In our opinion these interactions between MB and the cholinergic system invalidate the use of MB as a tool for the investigation of the L-arginine-NO-pathway, in particular when muscarinic receptor stimulation is involved. PMID:9298533

  19. Palladium-Catalyzed Reaction of Haloarenes with Diarylethynes: Synthesis, Structural Analysis, and Properties of Methylene-Bridged Arenes.

    PubMed

    Lee, Che-Wei; Liu, En-Chih; Wu, Yao-Ting

    2015-11-01

    Fluorenes and methylene-bridged polyarenes were easily and efficiently synthesized from haloarenes (or aryl triflates) and diarylethynes by a one-pot, two-step procedure. This protocol involves the palladium-catalyzed cycloisomerization and a subsequent base-mediated retro-aldol condensation. A major advantage is that the starting materials need not have ortho functional groups to complete the annulation. The backbone of the designed products was enlarged using dihaloarenes, highly π-conjugated haloarenes, or diarylalkynes. The mechanism of the formation of benzo[a]fluorene was investigated. The bowl-shaped structure of methylene-bridged indenocorannulene was verified by X-ray crystallography. The photophysical and electrochemical properties of the products thus prepared were investigated. PMID:26451853

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

    PubMed

    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. PMID:26335214

  1. Preparation and characterization of zinc oxide nanoflakes using anodization method and their photodegradation activity on methylene blue

    NASA Astrophysics Data System (ADS)

    Farrukh, Muhammad Akhyar; Thong, Chin-Kiat; Adnan, Rohana; Kamarulzaman, Mohd Amirrul

    2012-12-01

    In this work, we report the formation of leaf-like ZnO nanoflakes by anodization of zinc foil in a mixture of ammonium sulfate and sodium hydroxide electrolytes under various applied voltage and concentration of sodium hydroxide. The morphology and structure of ZnO nanoflakes were investigated by field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction analysis. In addition, the photocatalytic activity of the prepared nanoflakes zinc oxide was evaluated in the photodegradation of organic dye methylene blue (MB) solution under UV irradiation. It was found that zinc oxide prepared under high concentration of sodium hydroxide and high voltage showed better performance in the photodegradation of methylene blue.

  2. Comment on "Conformational analysis of small organic molecules using NOE and RDC data: A discussion of strychnine and α-methylene-γ-butyrolactone"

    NASA Astrophysics Data System (ADS)

    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.

  3. Methylene blue doped polymers: efficient media for optical recording

    NASA Astrophysics Data System (ADS)

    Ushamani, M.; Sreekumar, K.; Sudha Kartha, C.; Joseph, R.

    2004-05-01

    Polymer materials find application in optical storage technology, namely in the development of high information density and fast access type memories. A new polymer blend of methylene blue sensitized polyvinyl alcohol (PVA) and polyacrylic acid (PAA) in methanol is prepared and characterized and its comparison with methylene blue sensitized PVA in methanol and complexed methylene blue sensitized polyvinyl chloride (CMBPVC) is presented. The optical absorption spectra of the thin films of these polymers showed a strong and broad absorption region at 670-650 nm, matching the wavelength of the laser used. A very slow recovery of the dye on irradiation was observed when a 7:3 blend of polyvinyl alcohol/polyacrylic acid at a pH of 3.8 and a sensitizer concentration of 4.67 · 10-5 g/ml were used. A diffraction efficiency of up to 20% was observed for the MBPVA/alcohol system and an energetic sensitivity of 2000 mJ/cm2 was obtained in the photosensitive films with a spatial frequency of 588 lines/mm.

  4. An equation to calculate the actual methylene middle parameter as a function of temperature.

    PubMed

    Mohammad, Mohammad Amin

    2015-08-21

    Methylene middle parameter [Formula: see text] , the product of the methylene group's cross-sectional area ( [Formula: see text] ) and the root square of its dispersive free energy ( [Formula: see text] ), is the key parameter to calculate the dispersive surface components of solids (γs(d)) using inverse gas chromatography (IGC) at different temperatures. The only method reported to calculate [Formula: see text] as a function of temperature is the Dorris-Gray method. However, the conventional values of [Formula: see text] calculated by the Dorris-Gray method depend heavily on theoretical aspects. This paper establishes a novel equation calculating the actual [Formula: see text] as a function of temperature using the latest and most accurate surface parameters of seven successive n-alkanes. The obtained actual [Formula: see text] values are slightly higher those of the conventional [Formula: see text] . At 20°C, the actual [Formula: see text] generates γs(d) values less than those generated using the conventional [Formula: see text] by ∼3%, and this reduction in calculated γs(d) values increases linearly to become ∼5% at 100°C. Therefore, using the new actual [Formula: see text] seems to mitigate the discrepancy between the γs(d) values measured by IGC and those measured by the contact angle method. PMID:26187766

  5. Elusive transmetalation intermediate in copper-catalyzed conjugate additions: direct NMR detection of an ethyl group attached to a binuclear phosphoramidite copper complex.

    PubMed

    von Rekowski, Felicitas; Koch, Carina; Gschwind, Ruth M

    2014-08-13

    Copper-catalyzed asymmetric conjugate addition reactions are a very powerful and widely applied method for enantioselective carbon-carbon bond formation. However, structural and mechanistic insight into these famous reactions has been very limited so far. In this article, the first direct experimental detection of transmetalation intermediates in copper-catalyzed reactions is presented. Special combinations of (1)H,(31)P HMBC spectra allow for the identification of complexes with chemical bonds between the alkyl groups and the copper complexes. For the structural characterization of these transmetalation intermediates, a special approach is applied, in which samples using enantiopure ligands are compared with samples using enantiomeric mixtures of ligands. It is experimentally proven, for the first time, that the dimeric copper complex structure is retained upon transmetalation, providing an intermediate with mixed trigonal/tetrahedral coordination on the copper atoms. In addition, monomeric intermediates with one ligand, but no intermediates with two ligands, are detected. These experimental results, in combination with the well-known optimal ligand-to-copper ratio of 2:1 in synthetic applications, allow us to propose that a binuclear transmetalation intermediate is the reactive species in copper-catalyzed asymmetric conjugate addition reactions. This first direct experimental insight into the structure of the transmetalation intermediate is expected to support the mechanistic and theoretical understanding of this important class of reactions and to enable their further synthetic development. In addition, the special NMR approach presented here for the identification and characterization of intermediates below the detection limit of (1)H NMR spectra can be applied also to other classes of catalyses. PMID:25072403

  6. Topical and Intradermal Efficacy of Photodynamic Therapy with Methylene Blue and Light-Emitting Diode in the Treatment of Cutaneous Leishmaniasis Caused by Leishmania braziliensis

    PubMed Central

    Sbeghen, Mônica Raquel; Voltarelli, Evandra Maria; Campois, Tácito Graminha; Kimura, Elza; Aristides, Sandra Mara Alessi; Hernandes, Luzmarina; Caetano, Wilker; Hioka, Noboru; Lonardoni, Maria Valdrinez Campana; Silveira, Thaís Gomes Verzignassi

    2015-01-01

    Introduction: The topical and intradermal photodynamic therapy (PDT) effect of methylene blue (MB) using light-emitting diode (LED) as light source (MB/LED-PDT) in the treatment of lesions of American cutaneous leishmaniasis (ACL) caused by Leishmania braziliensis in hamsters were investigated. Methods: Hamsters were infected in the footpad with 4×107 promastigotes of L. braziliensis and divided in 4 groups: Control group was not treated, AmB group was treated with amphotericin B, MB-Id group received intradermal MB at the edge of the lesion and MB-Tp group received MB topic. After treatment with MB, the animals were illuminated using red LEDs at the 655 nm wavelength for 1 hour. The MB/LED-PDT was carried out three times a week for 12 weeks. Results: Animals of MB-Tp group presented lesion healing with significant diminution in extent of the lesion, and reduced parasite burden compared to control group; however, no significant difference was seen compared to the AmB group. MB-Tp group also showed reconstitution of the epithelium, the formation of collagen fibers, organization in the epidermis, a little disorganization and inflammation in the dermis. MB-Id was ineffective in all parameters evaluated, and it was comparable to the control group results. Conclusion: These data show that PDT with the use of MB-Tp and LED may be an alternative for the treatment of ACL. However, additional studies are being conducted to assess the potential of MB/LED-PDT, alone or in combination with conventional therapy, for the treatment of ACL. PMID:26464777

  7. Correlation between the 677C>T polymorphism in the methylene tetrahydrofolate reductase gene and serum homocysteine levels in coronary heart disease.

    PubMed

    Chen, Y Y; Wang, B N; Yu, X P

    2016-01-01

    The aim of the current study was to explore the correlation between serum homocysteine (HCY) levels and the methylene tetrahydrofolate reductase (MTHFR) gene 677C/T polymorphism and coronary heart disease (CHD). We consecutively enrolled 208 patients with CHD confirmed by CTA or coronary angiography from our hospital. An additional 200 healthy volunteers were enrolled as the control group. Serum HCY levels, MTHFR C677T genotype, and other related indicators were evaluated for the two groups. Compared to those in the control group, the serum HCY levels in the CHD patients were significantly higher (P < 0.05). The proportion of individuals with the heterozygous MTHFR CT genotype and homozygous mutant TT genotype among CHD patients was significantly higher than that in the control group (P < 0.05). In the acute coronary syndrome (ACS) subgroup, the proportion of those with the CT and TT genotypes was significantly higher than that of the stable CHD subgroup (P < 0.05). In summary, serum HCY levels were elevated in CHD patients, and the frequency of the CT and TT genotypes were also significantly increased, especially among the ACS subgroup. Taken together, this suggests that serum HCY levels and MTHFR C677T genotypes are correlated with CHD. PMID:27051002

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    Brahiti, N.; Hadjersi, T.; Menari, H.; Amirouche, S.; El Kechai, O.

    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.

  10. Calix[4]arene coated QCM sensors for detection of VOC emissions: Methylene chloride sensing studies.

    PubMed

    Temel, Farabi; Tabakci, Mustafa

    2016-06-01

    This paper describes the sensing studies of QCM sensors with coated some calixarene derivatives bearing different functional groups for some selected Volatile Organic Compounds (VOCs) such as acetone, acetonitrile, carbon tetrachloride, chloroform, methylene chloride (MC), N,N-dimethylformamide, 1,4-dioxane, ethanol, ethyl acetate, xylene, methanol, n-hexane and toluene. The initial experiments have revealed that whole the calix[4]arene modified QCM sensors exhibited strongest sensing ability to MC emissions. Thus, the detailed studies were performed for only MC emissions after the determination of relatively more effective calix-coated QCM sensors for MC emissions in aqueous media. The results demonstrated that QCM sensor coated with calix-7 bearing both amino and imidazole groups was most useful sensor for MC emissions with 54.1ppm of detection limit. Moreover, it was understood that cyclic structures, H-bonding capabilities and also good preorganization properties of calixarene derivatives played an important role in VOC sensing processes. PMID:27130112

  11. [Adsorption of methylene blue from water by the biochars generated from crop residues].

    PubMed

    Xu, Ren-Kou; Zhao, An-Zhen; Xiao, Shuang-Cheng; Yuan, Jin-Hua

    2012-01-01

    Biochars were prepared from straws of rice, peanut and soybean and rice hull using a low temperature pyrolysis method and adsorption of methylene blue by these biochars were investigated with batch and leaching experiments. Results indicated that biochars have high adsorption capacity for methylene blue and followed the order: rice straw char > soybean straw char > peanut straw char > rice hull char. This order is generally consistent with the amount of negative charge and specific surface area of these biochars. While methylene blue was mainly adsorbed specifically by the biochars, because the adsorption of methylene blue increased with the increase of ionic strength and the adsorption led to the shift of zeta potential of biochar particles to positive value direction. Langmuir equation fitted the adsorption isotherms well and can be used to describe the adsorption behaviors of methylene blue by the biochars. The maximum adsorption capacity of methylene blue predicted by langmuir equation was 196.1, 169.5, 129.9 and 89.3 mmol x kg(-1) for rice straw char, soybean straw char, peanut straw char and rice hull char, respectively. Leaching experiments show that rice hull char of 156 g can remove methylene blue from 30 L water containing 0.3 mmol x L(-1) of methylene blue completely and the cumulative amount of methylene blue absorbed by the biochar reaches 57.7 mmol x kg(-1). The biochars can be used as efficient adsorbents to remove methylene blue from waste water of dye. PMID:22452202

  12. Methylene blue photodynamic therapy in rats' wound healing: 21 days follow-up

    NASA Astrophysics Data System (ADS)

    Carneiro, Vanda Sanderana Macêdo; Catao, Maria Helena Chaves de Vasconcelos; Menezes, Rebeca Ferraz; Araújo, Natália Costa; Gerbi, Marleny Elizabeth Martinez

    2015-06-01

    The experimental evaluated the photodynamic therapy (PDT) in wound healing. It used 60 male rats, making two circular wounds at each animal. They were treated at 48hs intervals, with methylene blue (MB), low level laser treatment (LLLT) or both, thus resulting in PDT. The wounds were observed 01, 03, 07, 14 and 21 days after and then processed and subjected to HE staining to analyze granulation tissue, necrosis, epithelialization and collagen. After day 1, wounds treated with MB showed necrosis less intense than other groups, and the PDT group showed more intense granulation tissue. At day 3, reepithelialization was absent for half of injuries in the PDT group, and this group was also with lower collagen. However, at day 7, this same group presented reepithelialization more advanced than control group, which did not happen with those treated with MB or LLLT (p = 0.015). The results allow us to conclude that PDT difficulted reepithelization at 7th day and interfered in standard healing. However, when used separately, MB and LLLT interfered significantly compared to the control group, which did not happened to the PDT group. There was no significant difference between the treatment groups in other analysed times.

  13. Studies on the effects of essential-oil-based feed additives on performance, ileal nutrient digestibility, and selected bacterial groups in the gastrointestinal tract of piglets.

    PubMed

    Maenner, K; Vahjen, W; Simon, O

    2011-07-01

    The aim of this study was to assess the effects of 2 different phytogenic products on performance, ileal nutrient digestibility, and composition of the intestinal microbiota. The 2 phytogenic products contained different essential oil mixtures (EOM) characterized by either menthol (Mentha arvensis; EOM-M) or cinnamon aldehyde (Cinnamomum aromaticum; EOM-C) as main constituents. Three treatments consisted of control diet without EOM addition and diets supplemented with EOM-M or EOM-C. Reproducibility of the effects was examined in 4 trials with a total of 300 male castrated and female piglets weaned at 25 d of age. The number of pens per treatment in trials I through III were 7, 9, and 9, respectively, for research station conditions, and 10 in trial IV for simulated farm conditions. In research station conditions, the experimental unit consisted of flat deck pens with 2 piglets per pen, whereas it consisted of floor pens with straw bedding with 5 piglets per pen in farm conditions. The feed additives had no effect on feed intake or BW gain. Improvements (P < 0.05) in G:F were observed for EOM-M supplemented diets in 2 of 4 trials as well as for the combined data of all trials. These improvements were associated with greater (P<0.05) apparent ileal digestibility of CP and of most AA. The effect of EOM-C on these response criteria was intermediate between control and EOM-M. Real-time PCR analysis of the gastrointestinal contents for 7 bacterial groups (Lactobacillus spp., Enterococcus spp., Clostridium coccoides and Clostridium leptum cluster, Escherichia spp., and Escherichia coli toxin estII) indicated no effect of treatments on the gastrointestinal microbiota. It was concluded that EOM-M consistently improved feed efficiency in weaned piglets, and it was associated with improved ileal protein and AA digestibility. In general, however, the effectiveness of EOM as feed additives differs considerably depending on the constituents. PMID:21357448

  14. Identification of methylene diphenyl diisocyanate thermal degradation products in a generation chamber by liquid chromatography coupled with tandem mass spectrometry.

    PubMed

    Gagne, Sébastien; Cloutier, Yves

    2016-01-01

    Isocyanate thermal degradation characterization by liquid chromatography coupled with electrospray tandem mass spectrometry has been performed to elucidate the methylene diphenyl diisocyanate (MDI) thermal degradation structure emitted in a generation chamber using a temperature between 50°C and 180°C to produce MDI vapors. [M+H](+) ions containing an isocyanate functional group were studied by tandem mass spectrometry. The [M+H](+) ion analyses based on the combination of full scans and precursor ion scans were useful for identifying all structures. The compounds emitted were identified and validated as a mixture of compounds containing amine and isocyanate functions. Residual MDI, methylene diphenyl amino-isocyanate, and methylene diphenyl diamine were identified. Polymerized forms of these structures were also observed because amine and isocyanate chemical functions react rapidly to polymerize. These results must be used with special care by scientists establishing sensitization diagnostics and developing sampling devices using generation chambers as they must be related to MDI behavior in workplaces. Even if pure MDI is introduced in the generation chamber, several different compounds are generated when the MDI is heated at a high temperature. This can result in some misleading interpretations for non-specific isocyanate sampling device development and sensitization diagnostics as MDI is present in the chamber with other compounds with known adverse effects. PMID:26337647

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

    PubMed

    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. PMID:26433644

  16. Oxygen indicator composed of an organic/inorganic hybrid compound of methylene blue, reductant, surfactant and saponite.

    PubMed

    Sumitani, Makoto; Takagi, Shinsuke; Tanamura, Yoshihiko; Inoue, Haruo

    2004-08-01

    An organic/inorganic hybrid compound consisting of methylene blue, a cationic surfactant and a reductant intercalated into saponite was found to serve as an oxygen indicator that changes color in the presence of oxygen. A mixture of a blue colored dye, methylene blue, a reductant in the form of ascorbic acid or reducing sugar, and cetyltrimethylammonium ion intercalated into synthetic saponite became colorless in an atmosphere having an oxygen concentration of less than 0.1 vol%, and then returned to its blue color as a result of subsequent exposure to air. An oxygen indicator, in the form of a thin film coated on paper prepared by adding a pigment, phloxine B, to the above organic/inorganic hybrid compound, exhibited a pink color at oxygen concentrations of less than 0.1 vol%, and a blue color at oxygen concentrations of higher than 0.5 vol%. In addition, this oxygen indicator exhibited superior photo-fading resistance and storage stability compared with indicators using only methylene blue as the functional dye. PMID:15352503

  17. The effects of amine/nitro/hydroxyl groups on the benzene rings of redox additives on the electrochemical performance of carbon-based supercapacitors.

    PubMed

    Huang, Xuan; Wang, Qian; Chen, Xiang Ying; Zhang, Zhong Jie

    2016-04-21

    In this work, a series of porous carbon materials with hierarchical porosities have been synthesized via a template carbonization method, in which cheap CaCO3 serves as a template and glucose as a carbon precursor. During the carbonization process, CO2 produced by the decomposition of the CaCO3 template can act as an internal activating agent, significantly improving microporosity and mesoporosity. All the carbon materials obtained by regulating the ratio of glucose to CaCO3 exhibit the amorphous features with a low graphitization degree. Among them, the carbon-1 : 2 sample shows a high BET surface area of up to 818.5 m(2) g(-1) and a large total pore volume of 1.78 cm(3) g(-1) as well as a specific capacitance of 107.0 F g(-1) at 1 A g(-1). In addition, a series of hydroquinone (HQ), p-aminophenol (PAP) and p-nitrophenol (PNP) as novel redox additives that can produce pseudo-capacitances have been added into the KOH electrolyte for promoting the total capacitive performances via redox reactions at the electrode-electrolyte interface. As expected, a 2.5-fold increase in the galvanostatic capacitance of 240.0 F g(-1) in the HQ-0.5 electrolyte occurs, compared with the conventional KOH electrolyte. Similarly, the PAP-0.5 electrolyte and the PNP-0.5 electrolyte also show a high specific capacitance of 184.0 F g(-1) at 2 A g(-1) (156.6 F g(-1) at 3 A g(-1)) and 153.0 F g(-1) at 3 A g(-1), respectively. Additionally, the three kinds of electrolytes exhibit excellent cyclic stability. The remarkable improvement of supercapacitors is attributed to the quick reversible Faradaic reactions of amine and hydroxyl groups adhering to the phenyl rings, which largely accelerates electron migration and brings additional pseudocapacitive contribution for carbon-based supercapacitors. PMID:27030290

  18. Methylene blue exerts a neuroprotective effect against traumatic brain injury by promoting autophagy and inhibiting microglial activation

    PubMed Central

    ZHAO, MINGFEI; LIANG, FENG; XU, HANGDI; YAN, WEI; ZHANG, JIANMIN

    2016-01-01

    Traumatic brain injury (TBI) leads to permanent neurological impairment, and methylene blue (MB) exerts central nervous system neuroprotective effects. However, only one previous study has investigated the effectiveness of MB in a controlled cortical impact injury model of TBI. In addition, the specific mechanisms underlying the effect of MB against TBI remain to be elucidated. Therefore, the present study investigated the neuroprotective effect of MB on TBI and the possible mechanisms involved. In a mouse model of TBI, the animals were randomly divided into sham, vehicle (normal saline) or MB groups. The treatment time-points were 24 and 72 h (acute phase of TBI), and 14 days (chronic phase of TBI) post-TBI. The brain water content (BWC), and levels of neuronal death, and autophagy were determined during the acute phase, and neurological deficit, injury volume and microglial activation were assessed at all time-points. The injured hemisphere BWC was significantly increased 24 h post-TBI, and this was attenuated following treatment with MB. There was a significantly higher number of surviving neurons in the MB group, compared with the Vehicle group at 24 and 72 h post-TBI. In the acute phase, the MB-treated animals exhibited significantly upregulated expression of Beclin 1 and increased LC3-II to LC3-I ratios, compared with the vehicle group, indicating an increased rate of autophagy. Neurological functional deficits, measured using the modified neurological severity score, were significantly lower in the acute phase in the MB-treated animals and cerebral lesion volumes in the MB-treated animals were significantly lower, compared with the other groups at all time-points. Microglia were activated 24 h after TBI, peaked at 72 h and persisted until 14 days after TBI. Although the number of Iba-1-positive cells in the vehicle and MB groups 24 h post-TBI were not significantly different, marked microglial inhibition was observed in the MB group 72 h and 14 days after

  19. The vast thin plane of M31 corotating dwarfs: an additional fossil signature of the M31 merger and of its considerable impact in the whole Local Group

    NASA Astrophysics Data System (ADS)

    Hammer, François; Yang, Yanbin; Fouquet, Sylvain; Pawlowski, Marcel S.; Kroupa, Pavel; Puech, Mathieu; Flores, Hector; Wang, Jianling

    2013-06-01

    The recent discovery by Ibata et al. of a vast thin disc of satellites (VTDS) around M31 offers a new challenge for the understanding of the Local Group properties. This comes in addition to the unexpected proximity of the Magellanic Clouds (MCs) to the Milky Way (MW), and to another vast polar structure (VPOS), which is almost perpendicular to our Galaxy disc. We find that the VTDS plane is coinciding with several stellar, tidally induced streams in the outskirts of M31, and, that its velocity distribution is consistent with that of the giant stream (GS). This is suggestive of a common physical mechanism, likely linked to merger tidal interactions, knowing that a similar argument may apply to the VPOS at the MW location. Furthermore, the VTDS is pointing towards the MW, being almost perpendicular to the MW disc, as the VPOS is. We compare these properties to the modelling of M31 as an ancient, gas-rich major merger, which has been successfully used to predict the M31 substructures and the GS origin. We find that without fine tuning, the induced tidal tails are lying in the VTDS plane, providing a single and common origin for many stellar streams and for the vast stellar structures surrounding both the MW and M31. The model also reproduces quite accurately positions and velocities of the VTDS spheroidal dwarfs. Our conjecture leads to a novel interpretation of the Local Group past history, as a gigantic tidal tail due to the M31 ancient merger is expected to send material towards the MW, including the MCs. Such a link between M31 and the MW is expected to be quite exceptional, though it may be in qualitative agreement with the reported rareness of MW-MCs systems in nearby galaxies.

  20. Highly regioselective para-methylthiolation/bridging methylenation of arylamines promoted by NH4I.

    PubMed

    Xu, Yinfeng; Cong, Tiantian; Liu, Ping; Sun, Peipei

    2015-10-14

    Aryl methyl thioethers and methylene-bridged arylamines were synthesized via highly regioselective para-methylthiolation/bridging methylenation of arylamines using DMSO as the methylthio or methylene source in the presence of NH4I under metal-free conditions. For the substrates with both electron-donating and electron-withdrawing substituents, the reaction proceeded smoothly and gave moderate to good yields. PMID:26337143

  1. Molecular and biochemical identification of alien chromosome additions in shallot (Allium cepa L. Aggregatum group) carrying extra chromosome(s) of bunching onion (A. fistulosum L.).

    PubMed

    Yaguchi, Shigenori; Hang, Tran Thi Minh; Tsukazaki, Hikaru; Hoa, Vu Quynh; Masuzaki, Shin-ichi; Wako, Tadayuki; Masamura, Noriya; Onodera, Shuichi; Shiomi, Norio; Yamauchi, Naoki; Shigyo, Masayoshi

    2009-02-01

    To develop the bunching onion (Allium fistulosum L.; genomes, FF) chromosome-specific genetic markers for identifying extra chromosomes, eight shallot (A. cepa L. Aggregatum group; genomes, AA)--A. fistulosum monosomic addition plants (AA+nF) and 62 shallot--A. fistulosum single-alien deletion plants (AAF-nF) were analyzed by 23 different chromosome-specific genetic markers of shallot. The eight monosomic addition plants consisted of one AA+2F, two AA+6F, and five AA+8F. Of the 62 single-alien deletion plants, 60 could be identified as six different single-alien deletion lines (AAF-1F, -3F, -4F, -6F, -7F, and -8F) out of the eight possible types. Several single-alien deletion lines were classified on the basis of leaf and bulb characteristics. AAF-8F had the largest number of expanded leaves of five deletion plants. AAF-7F grew most vigorously, as expressed by its long leaf blade and biggest bulb size. AAF-4F had very small bulbs. AAF-7F and AAF-8F had different bulbs from those of shallot as well as other types of single-alien deletion lines in skin and outer scale color. Regarding the sugar content of the bulb tissues, the single-alien deletion lines showed higher fructan content than shallot. Moreover, shallot could not produce fructan with degree of polymerization (DP) 12 or higher, although the single-alien deletion lines showed DP 20 or higher. The content of S-alk(en)yl-L-cysteine sulfoxide (ACSO) in the single-alien deletion lines was significantly lower than that in shallot. These results indicated that chromosomes from A. fistulosum might carry anonymous factors to increase the highly polymerized fructan production and inhibit the synthesis of ACSO in shallot bulbs. Accordingly, alien chromosomes from A. fistulosum in shallot would contribute to modify the quality of shallot bulbs. PMID:19420800

  2. Removal of methylene blue from dye effluent using ageratum conyzoide leaf powder (ACLP)

    NASA Astrophysics Data System (ADS)

    Ezechi, Ezerie Henry; Kutty, Shamsul Rahman bin Mohamed; Malakahmad, Amirhossein; Isa, Mohamed Hasnain; Aminu, Nasiru; Salihi, Ibrahim Umar

    2015-07-01

    Methylene blue (MB), a common environmental pollutant discharged from dye effluents were removed from synthetic effluents in this study using ageratum conyzoide leaf powder. Effects of operating parameters such as pH, initial Methylene blue concentration, adsorbent weight and contact time were examined on methylene blue removal whereas stirring speed was constant at 100 rpm. Results show that low pH (3-4) had more Methylene blue removal than high pH. Methylene blue removal decreased when initial concentration was increased but increased when adsorbent weight was increased. Removal of Methylene blue by Ageratum conyzoide leaf powder was rapid and significantly above 80% in all initial concentrations examined. At optimum conditions of pH 3, 20 minutes contact time and adsorbent weight of 60 mg for Methylene blue initial concentration of 20 mg/L, 40 mg/L and 60 mg/L, Methylene blue removal of 84.7%, 83.9% and 81.2% were obtained respectively. Results suggest that Ageratum conyzoide leaf powder could be potential adsorbents for Methylene blue removal from dye effluents.

  3. Toxicology and metabolism of methylene chloride. (Latest citations from the Life Sciences Collection database). Published Search

    SciTech Connect

    Not Available

    1993-06-01

    The bibliography contains citations concerning methylene chloride, its effects on biological systems, and its metabolic fate. Both animal and human studies, and case reports are examined for methylene chloride toxicity. Exposure to the chemical through inhalation, ingestion, and contact is examined. Occupational exposure to methylene chloride is included, and risk factors are discussed. Long term carcinogenicity of methylene chloride is also considered. Toxicity of other chlorinated organic compounds is referenced in related bibliographies. (Contains a minimum of 78 citations and includes a subject term index and title list.)

  4. A Reminder of Methylene Blue's Effectiveness in Treating Vasoplegic Syndrome after On-Pump Cardiac Surgery

    PubMed Central

    Brown, Lisa; Tadros, Hany B.; Munfakh, Nabil A.

    2015-01-01

    The inflammatory response induced by cardiopulmonary bypass decreases vascular tone, which in turn can lead to vasoplegic syndrome. Indeed the hypotension consequent to on-pump cardiac surgery often necessitates vasopressor and intravenous fluid support. Methylene blue counteracts vasoplegic syndrome by inhibiting the formation of nitric oxide. We report the use of methylene blue in a 75-year-old man who developed vasoplegic syndrome after cardiac surgery. After the administration of methylene blue, his hypotension improved to the extent that he could be weaned from vasopressors. The use of methylene blue should be considered in patients who develop hypotension refractory to standard treatment after cardiac surgery. PMID:26504450

  5. On-line spectroscopic studies of group IV alkoxides and their interactions with organic additives during the sol-gel process

    SciTech Connect

    Wettling, D.; Truchet, S.; Guilment, J.; Poncelet, O.

    1996-12-31

    The potential of vibrational spectroscopy for the study of group 4 alkoxides M(OR){sub 4} has been demonstrated in several papers, but only a few of these papers have presented results from online measurements. The monitoring of different reactions such as the stabilization of the alkoxides with organic additives, the exchange processes between different metal alkoxides (R exchange or M exchange) and the hydrolysis process can be of great importance for the development of new synthetic routes leading to materials which are easier to process. NIR spectroscopy is a very versatile technique but lacks specificity while IR and Raman give more interpretive results but are not always easy during processing. The authors used both techniques along with chemometric tools to extract relevant information on their processes. The 2D correlation allowed benefits from the specificity of IR and Raman to develop robust NIR methods which are able to be used on line to monitor the different steps of the sol-gel process.

  6. Effects of silver and group II fluoride solid lubricant additions to plasma-sprayed chromium carbide coatings for foil gas bearings to 650 C

    NASA Technical Reports Server (NTRS)

    Wagner, R. C.; Sliney, Harold E.

    1986-01-01

    A new self-lubricating coating composition of nickel aluminide-bonded chromium carbide formulated with silver and Group II fluorides was developed in a research program on high temperature solid lubricants. One of the proposed applications for this new coating composition is as a wide temperature spectrum solid lubricant for complaint foil gas bearings. Friction and wear properties were obtained using a foil gas bearing start-stop apparatus at temperatures from 25 to 650 C. The journals were Inconel 748. Some were coated with the plasma sprayed experimental coating, others with unmodified nickel aluminide/chromium carbide as a baseline for comparison. The additional components were provided to assist in achieving low friction over the temperature range of interest. Uncoated, preoxidized Inconel X-750 foil bearings were operated against these surfaces. The foils were subjected to repeated start/stop cycles under a 14-kPa (2-Psi) bearing unit loading. Sliding contact occurred during lift-off and coastdown at surface velocities less than 6 m/s (3000 rPm). Testing continued until 9000 start/stop cycles were accumulated or until a rise in starting torque indicated the journal/bearing had failed. Comparison in coating performance as well as discussions of their properties and methods of application are given.

  7. Additional Evidence that Juvenile Oyster Disease Is Caused by a Member of the Roseobacter Group and Colonization of Nonaffected Animals by Stappia stellulata-Like Strains†

    PubMed Central

    Boettcher, Katherine J.; Barber, Bruce J.; Singer, John T.

    2000-01-01

    Juvenile oyster disease (JOD) causes significant annual mortalities of hatchery-produced Eastern oysters, Crassostrea virginica, cultured in the Northeast. We have reported that a novel species of the α-proteobacteria Roseobacter group (designated CVSP) was numerically dominant in JOD-affected animals sampled during the 1997 epizootic on the Damariscotta River, Maine. In this study we report the isolation of CVSP bacteria from JOD-affected oysters during three separate epizootics in 1998. These bacteria were not detected in nonaffected oysters at the enzootic site, nor in animals raised at a JOD-free site. Animals raised at the JOD enzootic site that were unaffected by JOD were stably and persistently colonized by Stappia stellulata-like strains. These isolates (designated M1) inhibited the growth of CVSP bacteria in a disk-diffusion assay and thus may have prevented colonization of these animals by CVSP bacteria in situ. Laboratory-maintained C. virginica injected with CVSP bacteria experienced statistically significant elevated mortalities compared to controls, and CVSP bacteria were recovered from these animals during the mortality events. Together, these results provide additional evidence that CVSP bacteria are the etiological agent of JOD. Further, there are no other descriptions of specific marine α-proteobacteria that have been successfully cultivated from a defined animal host. Thus, this system presents an opportunity to investigate both bacterial and host factors involved in the establishment of such associations and the role of the invertebrate host in the ecology of these marine α-proteobacteria. PMID:10966410

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

    PubMed

    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. PMID:24788930

  9. Microwave assisted rapid synthesis of N-methylene phosphonic chitosan via Mannich-type reaction.

    PubMed

    Dadhich, Prabhash; Das, Bodhisatwa; Dhara, Santanu

    2015-11-20

    Bio-conjugation or functional group substitutions are well-explored methods to enhance the physico-chemical and biochemical functionality of chitosan. N-Methylene phosphonic chitosan (NMPC) is one of the major substituted forms of chitosan, which has significant bioactivity and promising biomedical application. However, the reported synthesis methods of NMPC have limitations alike poor yield, higher degradation rate and most importantly long synthesis time (∼14h). In the current study, rapid synthesis of NMPC via a Mannich type reaction route using microwave irradiation has been reported. This method of NMPC synthesis offers significantly less synthesis time with competitive product yield. Synthesized NMPC was characterized via NMR, FTIR, EDS, XRD and thermal analysis. Further, viscosity average molecular weight, solubility, and conductivity of the substituted polymer were measured. Preliminary cyto-compatibility results of synthesized NMPC were promising for further exploration in biomedical applications. PMID:26344290

  10. Effect of a magnetic field on the adsorptive removal of methylene blue onto wheat straw biochar.

    PubMed

    Li, Guoting; Zhu, Weiyong; Zhang, Chunyu; Zhang, Shen; Liu, Lili; Zhu, Lingfeng; Zhao, Weigao

    2016-04-01

    Biochar pyrolyzed from wheat straw was innovatively used for the adsorptive removal of cationic dye methylene blue through exposure to a magnetic field. The adsorption capability of the biochar pyrolyzed at 200 °C exceeded that of samples pyrolyzed at higher temperatures. The surface acidic functional groups of wheat straw biochar were deduced to be more sensitive to the effects of the external magnetic field. The enhancement of the magnetic field achieved by increases in the initial dye concentration, and a decrease in the biochar dosage and solution pH, were more significant compared with those caused by other conditions. Kinetic experiments indicated that chemisorption occurred during adsorption. The qmax values for dye adsorption without, and with, an external magnetic field were found to be 46.6 and 62.5mg/g, respectively. These demonstrated that wheat straw biochar could be used for the efficient adsorption of pollutants when assisted by an external magnetic field. PMID:26845216

  11. Anticancer properties of novel 4-methylene-1,2-diphenylpyrazolidin-3-ones.

    PubMed

    Gach, Katarzyna; Szymański, Jacek; Pomorska, Dorota; Długosz, Angelika; Modranka, Jakub; Michalak, Marlena; Janecki, Tomasz; Janecka, Anna

    2015-11-01

    The limited success of the currently used antitumor therapies is the driving force for organic chemists to seek new lead structures with anticancer potential. Two α-methylene-γ-lactams with an additional nitrogen atom in the lactam ring, 5-vinyl-1,2-diphenyl-4-methylenepyrazolidin-3-one (2a) and 5-phenyl-1,2-diphenyl-4-methylenepyrazolidin-3-one (2b) have been synthesized. Their anticancer activity was assessed in MCF-7 cells. Both compounds inhibited cell proliferation and induced DNA damage and apoptosis, with 2a being the more potent analog. Synergistic effects of 2a used in combination with known anticancer drugs, 5-fluorouracil, taxol, and oxaliplatin were evaluated. Compound 2a significantly enhanced the antitumor action of oxaliplatin and 5-fluorouracil, but not taxol. PMID:25832885

  12. Synthesis, Characterization, and Evaluation of Cytotoxicity of Poly(3-methylene-2-pyrrolidone).

    PubMed

    Heyns, Ingrid M; Pfukwa, Rueben; Klumperman, Bert

    2016-05-01

    The homo- and copolymerization of 3-methylene-2-pyrrolidone (3M2P) is introduced. 3M2P is readily polymerized via conventional free radical polymerization, and two reversible deactivation radical polymerization methods including reversible addition-fragmentation (chain) transfer and single-electron-transfer living radical polymerization. Poly(3M2P) has a high thermal stability and a very high glass transition temperature. Poly(3M2P) does not dissolve in most common organic solvents, but it has a high aqueous solubility. Cytotoxicity tests reveal that it is nontoxic to cells, even up to concentrations of 1 mg/mL. This adds poly(3M2P) to the family of water-soluble and biocompatible pyrrolidone-based vinyl polymers. PMID:27087262

  13. Rapid and simple spectrophotometric determination of persulfate in water by microwave assisted decolorization of Methylene Blue.

    PubMed

    Zhao, Lajuan; Yang, Shiying; Wang, Leilei; Shi, Chao; Huo, Meiqing; Li, Yan

    2015-05-01

    A rapid and simple method for determination of persulfate in aqueous solution was developed. The method is based on the rapid reaction of persulfate with Methylene Blue (MB) via domestic microwave activation, which can promote the activation of persulfate and decolorize MB quickly. The depletion of MB at 644 nm (the maximum absorption wavelength of MB) is in proportion to the increasing concentration of persulfate in aqueous solution. Linear calibration curve was obtained in the range 0-1.5 mmol/L, with a limit of detection of 0.0028 mmol/L. The reaction time is rapid (within 60 sec), which is much shorter than that used for conventional methods. Compared with existing analytical methods, it need not any additives, especially colorful Fe2+, and need not any pretreatment for samples, such as pH adjustment. PMID:25968279

  14. Thermochemical Properties and Bond Dissociation Energies for Fluorinated Methanol, CH3-xFxOH, and Fluorinated Methyl Hydroperoxides, CH3-xFxOOH: Group Additivity.

    PubMed

    Wang, Heng; Bozzelli, Joseph W

    2016-09-01

    Oxygenated fluorocarbons are routinely found in sampling of environmental soils and waters as a result of the widespread use of fluoro and chlorofluoro carbons as heat transfer fluids, inert materials, polymers, fire retardants and solvents; the influence of these chemicals on the environment is a growing concern. The thermochemical properties of these species are needed for understanding their stability and reactions in the environment and in thermal process. Structures and thermochemical properties on the mono- to trifluoromethanol, CH3-xFxOH, and fluoromethyl hydroperoxide, CH3-xFxOOH (1 ≤ x ≤ 3), are determined by CBS-QB3, CBS-APNO, and G4 calculations. Entropy, S°298, and heat capacities, Cp(T)'s (300 ≤ T/K ≤ 1500) from vibration, translation, and external rotation contributions are calculated on the basis of the vibration frequencies and structures obtained from the B3LYP/6-31+G(d,p) density functional method. Potential barriers for the internal rotations are also calculated from this method and used to calculate hindered rotor contributions to S°298 and Cp(T)'s using direct integration over energy levels of the internal rotational potentials. Standard enthalpies of formation, ΔfH°298 (units in kcal mol(-1)) are CH2FOOH (-83.7), CHF2OOH (-138.1), CF3OOH (-193.6), CH2FOO(•) (-44.9), CHF2OO(•) (-99.6), CF3OO(•) (-153.8), CH2FOH (-101.9), CHF2OH (-161.6), CF3OH (-218.1), CH2FO(•) (-49.1), CHF2O(•) (-97.8), CF3O(•) (-150.5), CH2F(•) (-7.6), CHF2(•) (-58.8), and CF3(•) (-112.6). Bond dissociation energies for the R-OOH, RO-OH, ROO-H, R-OO(•), RO-O(•), R-OH, RO-H, R-O(•), and R-H bonds are determined and compared with methyl hydroperoxide to observe the trends from added fluoro substitutions. Enthalpy of formation for the fluoro-hydrocarbon oxygen groups C/F/H2/O, C/F2/H/O, C/F3/O, are derived from the above fluorinated methanol and fluorinated hydroperoxide species for use in Benson's Group Additivity. It was determined that

  15. Water based drilling mud additive

    SciTech Connect

    McCrary, J.L.

    1983-12-13

    A water based fluid additive useful in drilling mud used during drilling of an oil or gas well is disclosed, produced by reacting water at temperatures between 210/sup 0/-280/sup 0/ F. with a mixture comprising in percent by weight: gilsonite 25-30%, tannin 7-15%, lignite 25-35%, sulfonating compound 15-25%, water soluble base compound 5-15%, methylene-yielding compound 1-5%, and then removing substantially all of the remaining water to produce a dried product.

  16. Methylene blue-enhanced arthroscopic resection of dorsal wrist ganglions.

    PubMed

    Lee, Byung Joo; Sawyer, Gregory A; Dasilva, Manuel F

    2011-12-01

    The ganglion is the most common soft tissue mass of the hand and wrist. Over the past 10 to 15 years, there has been a growing interest in arthroscopic treatment of dorsal wrist ganglions. Proposed advantages of arthroscopy include greater motion (particularly wrist flexion), improved cosmesis, and potential to identify/treat other intra-articular pathology. Despite the documented clinical success of arthroscopic ganglion excision, limitations include inconsistent identification of the ganglion stalk. Our described technique offers a means by which to improve visualization of the ganglion stalk intra-articularly to produce a more effective and efficient arthroscopic ganglion excision. During the procedure, a small volume of methylene blue solution is injected into the cyst. Its communication with the joint is apparent arthroscopically, thus identifying the location of the stalk. With the ability to precisely identify the ganglion stalk using an injection of methylene blue, the surgeon can direct the arthroscopic debridement toward the appropriate pathologic tissue. Unnecessary debridement of uninvolved tissue can be avoided with the technique. This also allows for optimal portal placement and, in particular, indicates whether a midcarpal portal should be employed. This should result in fewer recurrences, decreased operative time, and less iatrogenic injury. PMID:22105637

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

    PubMed

    Mirmohammadi, Mirtaghi; Ibrahim, M Hakimi; Ahmad, Anees; Kadir, Mohd Omar Abdul; Mohammadyan, M; Mirashrafi, S B

    2009-04-01

    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 EC\\UV 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 mug/m(3), 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. PMID:20165612

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

    PubMed Central

    Mirmohammadi, Mirtaghi; Ibrahim, M. Hakimi; Ahmad, Anees; Kadir, Mohd Omar Abdul; Mohammadyan, M.; Mirashrafi, S. B.

    2009-01-01

    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 EC\\UV 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. PMID:20165612

  19. 21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...-antispasmodic preparations that contained methylene blue cause Heinz body hemolytic anemia in cats when used... Heinz body hemolytic anemia reaction to methylene blue has also been demonstrated in dogs under... inclusion bodies (Heinz bodies) and associated hemolytic anemia is unclear. (2) The effectiveness of...

  20. 21 CFR 520.154b - Bacitracin methylene disalicylate and streptomycin sulfate powder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... sulfate powder. 520.154b Section 520.154b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... ANIMAL DRUGS § 520.154b Bacitracin methylene disalicylate and streptomycin sulfate powder. (a) Specifications. Each gram of powder contains 200 units bacitracin methylene disalicylate and streptomycin...

  1. 21 CFR 520.154b - Bacitracin methylene disalicylate and streptomycin sulfate powder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... sulfate powder. 520.154b Section 520.154b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... ANIMAL DRUGS § 520.154b Bacitracin methylene disalicylate and streptomycin sulfate powder. (a) Specifications. Each gram of powder contains 200 units bacitracin methylene disalicylate and streptomycin...

  2. Terahertz Spectroscopy of Deuterated Methylene Bi-Radical CD_2

    NASA Astrophysics Data System (ADS)

    Ozeki, Hiroyuki; Bailleux, Stephane

    2015-06-01

    Methylene, the parent of the carbene compounds, plays a crucial role in many chemical reactions. This bi-radical is a known interstellar molecule that has been detected towards hot cores in dense interstellar clouds. CH_2 is also thought to be present in cometary atmospheres. In the gas phase chemical models of both dense and diffuse molecular clouds, CH_2 is a key intermediate in interstellar carbon chemistry which is produced primarily by dissociative recombination of the methyl ion, CH^+_3. Recently tentative detection of the mono-deuterated methyl ion, CH_2D^+ has been reported toward an infrared source in the vicinity of Orion. Deuterated methylene CHD and CD_2 can be produced from this ion or its counterpart CHD^+_2 by dissociative recombination with an electron: CH2D+ + e- → CHD+ H or {CH2 + D}, CHD2+ ~+ e- → CHD+ D or CD2 + H. Thus, both CHD and CD_2 can be observed in warm interstellar clouds, where the deuterium fractionation process is important. Precise laboratory reference data are desirable for radioastronomical observation of these molecules. Here we report on our high-resolution spectroscopic investigation on the deuterated methylene radical, CD_2 (X ^3B_1) up to 1.45 THz. At present time, eleven out of the twelve fine-structure components of four pure rotational transitions have been newly recorded, and these measurements double the number of previously observed transitions. CD_2 was generated in a discharge in CD_2CO which was obtained from the flash pyrolysis of acetic anhydride-d6 ((CD_3CO)_2O). Effort is currently made to measure the astronomically important 111 - 000 transition whose fine-structure components are predicted to occur at 1.224,1.228 and 1.234 THz. D. C. Lis, P. F. Goldsmith, E. A. Bergin et al. 2009, in Submillimeter Astrophysics and Technology, ASP Conf. Ser., 417, 23. H. Ozeki and S. Saito J. Chem. Phys. 1996, 104, 2167.

  3. Characterization of methylene diphenyl diisocyanate haptenated human serum albumin and hemoglobin

    PubMed Central

    Mhike, Morgen; Chipinda, Itai; Hettick, Justin M.; Simoyi, Reuben H.; Lemons, Angela; Green, Brett J.; Siegel, Paul D.

    2013-01-01

    Protein haptenation by polyurethane industrial intermediate methylene diphenyl diisocyanate (MDI) is thought to be an important step in the development of diisocyanate (dNCO)-specific allergic sensitization; however, MDI haptenated albumins used to screen specific antibody are often poorly characterized. Recently, the need to develop standardized immunoassays using a consistent, well characterized dNCO-haptenated protein to screen for the presence of MDI-specific IgE and IgG from workers’ sera has been emphasized and recognized. This has been challenging to achieve due to the bivalent, electrophilic nature of dNCO leading to the capability to produce multiple cross-linked protein species and polymeric additions to proteins. In the present study, MDI was reacted with human serum albumin (HSA) and hemoglobin (Hb) at molar ratios ranging from 1:1 to 40:1 MDI: protein. Adducts were characterized by (1) loss of available trinitrobenzene sulfonic acid (TNBS) binding to primary amines, (2) electrophoretic migration in polyacrylamide gels, (3) quantification of methylene diphenyl diamine following acid hydrolysis and (4) immunoassay. Concentration dependent changes in all the above noted parameters were observed demonstrating increase in both number and complexity of conjugates formed with increasing MDI concentration. In conclusion, a series of bio-analytical assays should be performed to standardize MDI-antigen preparations across lots and laboratories for measurement of specific antibody in exposed workers which in total indicate degree of intra- and inter-molecular cross-linking, number of dNCO bound, number of different specific binding sites on the protein and degree of immuno-reactivity. PMID:23743149

  4. Control of burn wound sepsis in rats by methylene blue-mediated photodynamic treatment

    NASA Astrophysics Data System (ADS)

    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.

  5. Neurotoxic effects of methylene chloride: are they long lasting in humans?

    PubMed Central

    Lash, A A; Becker, C E; So, Y; Shore, M

    1991-01-01

    The neurotoxicity of methylene chloride (MC) is of special interest because of its acute effects on the central nervous system (CNS) and its metabolic conversion to carbon monoxide. A cohort study of retired airline mechanics was conducted to examine the hypothesis that long term exposure to MC results in lasting effects on the CNS. Retirees were studied to eliminate effects of current occupational exposures. The total retiree population (n = 1758) was surveyed to identify mechanics who met specific occupational, demographic, and medical criteria. A group of eligible retirees having long term exposure to MC and another group with low probability of exposure to solvents were given a comprehensive battery of physiological and psychological tests. The exposure groups were similar for all potential confounders that were measured. No statistically significant differences between groups were detected on outcome measures, although subtle differences in attention and memory were identified. Thus no firm evidence was found to support the hypothesis of lasting CNS effects in retired mechanics with long term exposure to MC. PMID:2064980

  6. Measuring the bioactivity and molecular conformation of typically globular proteins with phenothiazine-derived methylene blue in solid and in solution: A comparative study using photochemistry and computational chemistry.

    PubMed

    Ding, Fei; Xie, Yong; Peng, Wei; Peng, Yu-Kui

    2016-05-01

    distinction originates from different spatial structures of proteins and noncovalent interactions between proteins and methylene blue. In addition, biological relevance of the biorecognition of methylene blue with proteins was briefly discussed. We hope that this study could provide further standpoint so that one explore the biological activity of methylene blue and also phenothiazines. PMID:26950891

  7. Methylene blue adsorption on a DMPA lipid langmuir monolayer.

    PubMed

    Giner Casares, Juan José; Camacho, Luis; Martín-Romero, Maria Teresa; López Cascales, José Javier

    2010-07-12

    Adsorption of methylene blue (MB) onto a dimyristoylphosphatidic acid (DMPA) Langmuir air/water monolayer is studied by molecular dynamics (MD) simulations, UV reflection spectroscopy and surface potential measurements. The free-energy profile associated with MB transfer from water to the lipid monolayer shows two minima of -66 and -60 kJ mol(-1) for its solid and gas phase, respectively, corresponding to a spontaneous thermodynamic process. From the position of the free-energy minima, it is possible to predict the precise location of MB in the interior of the DMPA monolayer. Thus, MB is accommodated in the phosphoryl or carbonyl region of the DMPA Langmuir air/water interface, depending on the isomorphic state (solid or gas phase, respectively). Reorientation of MB, measured from the bulk solution to the interior of the lipid monolayer, passes from a random orientation in bulk solution to an orientation parallel to the surface of the lipid monolayer when MB is absorbed. PMID:20544777

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

    PubMed

    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. PMID:22400211

  9. Adsorption studies of methylene blue dye on tunisian activated lignin

    NASA Astrophysics Data System (ADS)

    Kriaa, A.; Hamdi, N.; Srasra, E.

    2011-02-01

    Activated carbon prepared from natural lignin, providing from a geological deposit, was used as the adsorbent for the removal of methylene blue (MB) dye from aqueous solutions. Batch adsorption studies were conducted to evaluate various experimental parameters like pH and contact time for the removal of this dye. Effective pH for MB removal was 11. Kinetic study showed that the adsorption of dye was gradual process. Quasi equilibrium reached in 4 h. Pseudo-first-order, pseudo-second-order were used to fit the experimental data. Pseudo-second-order rate equation was able to provide realistic description of adsorption kinetics. The experimental isotherms data were also modelled by the Langmuir and Freundlich equation of adsorption. Equilibrium data fitted well with the Langmuir model with maximum monolayer adsorption capacity of 147 mg/g. Activated lignin was shown to be a promising material for adsorption of MB from aqueous solutions.

  10. Sequestration of Methylene Blue into Polyelectrolyte Complex Coacervates.

    PubMed

    Zhao, Mengmeng; Zacharia, Nicole S

    2016-08-01

    Polyelectrolyte complex coacervation is a process that has been proposed as a model for protocell formation due to its ability to compartmentalize chemicals in solution without a membrane. During the liquid-liquid phase separation that results in water rich and polyelectrolyte rich phases, small molecules present in solution selectively partition to one phase over the other. This sequestration is based on relative affinities. Here, a study of the sequestration of methylene blue (MB) into the complex coacervate phase of three pairs of synthetic polyelectrolytes is presented; branched polyethylene imine with polyacrylic acid, polyvinyl sulfonate, or poly(4-styrenesulfonic acid). These materials are characterized with UV-vis, zeta potential measurements, and dynamic light scattering. The branched polyethylene imine/poly(4-styrenesulfonic acid) system is shown to have a significantly higher sequestration capacity for the MB as compared to either of the other two systems, based on π-π interactions which are not possible in the other systems. PMID:27336461

  11. Assess health effects associated with dichloromethane (methylene chloride). Final report

    SciTech Connect

    Not Available

    1988-03-09

    On August 13-14, 1987 the Halogenated Organics Subcommittee of the Science Advisory Board's Environmental Health Committee met in Washington, D.C. to review two documents prepared by EPA's Office of Research and Development that assess health effects associated with dichloromethane (methylene chloride). The documents included: a June 1987 Draft Technical Analysis of New Methods and Data Regarding Dichloromethane: Pharmacokinetics, Mechanism of Action and Epidemiology, a July 1987 Draft Addendum to the Health Assessment Document for Dichloromethane: Pharmacokinetics, Mechanism of Action and Epidemiology. The Subcommittees concluded that the Addendum was one of the best documents it has received in terms of its clarity, coverage of the data and analysis of scientific issues. The document clearly demonstrates the potential utility of pharmacokinetics data in risk assessment.

  12. Nanosized ZSM-5 will improve photodynamic therapy using Methylene blue.

    PubMed

    Kariminezhad, H; Habibi, M; Mirzababayi, N

    2015-07-01

    Nowadays, nanotechnology is growing to improve Photodynamic Therapy and reduce its side effects. In this research, the synthesized co-polymeric Zeolite Secony Mobile-5 (ZSM-5) was employed to modify Methylene Blue (MB) for these reasons. UV-Visible, FTIR, XRD analysis and SEM images were used to investigate obtained nanostructure. The crystal size for these nanostructures were determined 75 nm and maximum adsorption capacity of MB in the nanostructure was estimated 111 (mg g(-1)). Also, the role of Polyethylene Glycol (PEG) was studied as a capable non-toxic polymeric coating to overcome biological barriers. Moreover, potential of singlet oxygen production of the synthesized nanostructure was compared with MB and ZSM-5 nanoparticles control samples. Synthesized nanodrugs show impressive light induced singlet oxygen production efficiency. PMID:25900556

  13. Excited states of methylene from quantum Monte Carlo.

    PubMed

    Zimmerman, Paul M; Toulouse, Julien; Zhang, Zhiyong; Musgrave, Charles B; Umrigar, C J

    2009-09-28

    The ground and lowest three adiabatic excited states of methylene are computed using the variational Monte Carlo and diffusion Monte Carlo (DMC) methods using progressively larger Jastrow-Slater multideterminant complete active space (CAS) wave functions. The highest of these states has the same symmetry, (1)A(1), as the first excited state. The DMC excitation energies obtained using any of the CAS wave functions are in excellent agreement with experiment, but single-determinant wave functions do not yield accurate DMC energies of the states of (1)A(1) symmetry, indicating that it is important to include in the wave function Slater determinants that describe static (strong) correlation. Excitation energies obtained using recently proposed pseudopotentials [Burkatzki et al., J. Chem. Phys. 126, 234105 (2007)] differ from the all-electron excitation energies by at most 0.04 eV. PMID:19791848

  14. Microwave-Assisted Condensation Reactions of Acetophenone Derivatives and Activated Methylene Compounds with Aldehydes Catalyzed by Boric Acid under Solvent-Free Conditions.

    PubMed

    Brun, Elodie; Safer, Abdelmounaim; Carreaux, François; Bourahla, Khadidja; L'helgoua'ch, Jean-Martial; Bazureau, Jean-Pierre; Villalgordo, Jose Manuel

    2015-01-01

    We here disclosed a new protocol for the condensation of acetophenone derivatives and active methylene compounds with aldehydes in the presence of boric acid under microwave conditions. Implementation of the reaction is simple, healthy and environmentally friendly owing to the use of a non-toxic catalyst coupled to a solvent-free procedure. A large variety of known or novel compounds have thus been prepared, including with substrates bearing acid or base-sensitive functional groups. PMID:26111185

  15. The hemodynamic effects of methylene blue when administered at the onset of cardiopulmonary bypass.

    PubMed

    Maslow, Andrew D; Stearns, Gary; Butala, Parag; Batula, Parag; Schwartz, Carl S; Gough, Jeffrey; Singh, Arun K

    2006-07-01

    Hypotension occurs during cardiopulmonary bypass (CPB), in part because of induction of the inflammatory response, for which nitric oxide and guanylate cyclase play a central role. In this study we examined the hemodynamic effects of methylene blue (MB), an inhibitor of guanylate cyclase, administered during cardiopulmonary bypass (CPB) to patients taking angiotensin-converting enzyme inhibitors. Thirty patients undergoing cardiac surgery were randomized to receive either MB (3 mg/kg) or saline (S) after institution of CPB and cardioplegic arrest. CPB was managed similarly for all study patients. Hemodynamic data were assessed before, during, and after CPB. The use of vasopressors was recorded. All study patients experienced a similar reduction in mean arterial blood pressure (MAP) and systemic vascular resistance (SVR) with the onset of CPB and cardioplegic arrest. MB increased MAP and SVR and this effect lasted for 40 minutes. The saline group demonstrated a persistently reduced MAP and SVR throughout CPB. The saline group received phenylephrine more frequently during CPB, and more norepinephrine after CPB to maintain a desirable MAP. The MB group recorded significantly lower serum lactate levels despite equal or greater MAP and SVR. In conclusion, administration of MB after institution of CPB for patients taking angiotensin-converting enzyme inhibitors increased MAP and SVR and reduced the need for vasopressors. Furthermore, serum lactate levels were lower in MB patients, suggesting more favorable tissue perfusion. PMID:16790616

  16. Effects of methylene blue in acute lung injury induced by oleic acid in rats

    PubMed Central

    Cassiano Silveira, Ana Paula; Vento, Daniella Alves; Albuquerque, Agnes Afrodite Sumarelli; Celotto, Andrea Carla; Tefé-Silva, Cristiane; Ramos, Simone Gusmão; Rubens de Nadai, Tales; Rodrigues, Alfredo José; Poli-Neto, Omero Benedicto

    2016-01-01

    Background In acute lung injury (ALI), rupture of the alveolar-capillary barrier determines the protein-rich fluid influx into alveolar spaces. Previous studies have reported that methylene blue (MB) attenuates such injuries. This investigation was carried out to study the MB effects in pulmonary capillary permeability. Methods Wistar rats were divided into five groups: (I) Sham: saline bolus; (II) MB, MB infusion for 2 h; (III) oleic acid (OA), OA bolus; (IV) MB/OA, MB infusion for 2 h, and at 5 min after from the beginning, concurrently with an OA bolus; and (V) OA/MB, OA bolus, and after 2 h, MB infusion for 2 h. After 4 h, blood, bronchoalveolar lavage (BAL), and lung tissue were collected from all groups for analysis of plasma and tissue nitric oxide, calculation of the wet weight to dry weight ratio (WW/DW), and histological examination of lung tissue. Statistical analysis was performed using nonparametric test. Results Although favourable trends have been observed for permeability improvement parameters (WW/WD and protein), the results were not statistically significant. However, histological analysis of lung tissue showed reduced lesion areas in both pre- and post-treatment groups. Conclusions The data collected using this experimental model was favourable only through macroscopic and histological analysis. These observations are valid for both MB infusions before or after induction of ALI. PMID:26855944

  17. Synthesis, spectral characterization, thermal behaviour, antibacterial activity and DFT calculation on N'-[bis(methylsulfanyl) methylene]-2-hydroxybenzohydrazide and N'-(4-methoxy benzoyl)-hydrazinecarbodithioic acid ethyl ester.

    PubMed

    Bharty, M K; Dani, R K; Kushawaha, S K; Prakash, Om; Singh, Ranjan K; Sharma, V K; Kharwar, R N; Singh, N K

    2015-06-15

    Two new compounds N'-[bis(methylsulfanyl) methylene]-2-hydroxybenzohydrazide {Hbmshb (1)} and N'-(4-methoxy benzoyl)-hydrazinecarbodithioic acid ethyl ester {H2mbhce (2)} have been synthesized and characterized with the aid of elemental analyses, IR, NMR and single crystal X-ray diffraction data. Compounds 1 and 2 crystallize in orthorhombic and monoclinic systems with space group Pna21 and P21/n, respectively. Inter and intra molecular hydrogen bonding link two molecules and provide linear chain structure. In addition to this, compound 2 is stabilized by CH⋯π and NH⋯π interactions. Molecular geometry from X-ray analysis, geometry optimization, charge distribution, bond analysis, frontier molecular orbital (FMO) analysis and non-linear optical (NLO) effects have been performed using the density functional theory (DFT) with the B3LYP functional. The bioefficacy of compounds has been examined against the growth of bacteria to evaluate their anti-microbial potential. Compounds 1 and 2 are thermally stable and show NLO behaviour better than the urea crystal. PMID:25767993

  18. Metachromasy as an indicator of photostabilization of methylene blue adsorbed to clays and minerals.

    PubMed

    Samuels, Maya; Mor, Omer; Rytwo, Giora

    2013-04-01

    The influence of methylene blue adsorption to different clays on its photodegradation was studied. Methylene blue in solution was decomposed by sunlight in a zero-order process. Adsorption to some clay minerals (sepiolite and vermiculite) and a zeolite (clinoptilolite) accelerated the degradation process, and converted it to a first-order reaction. On the other hand, adsorption to other clay minerals (palygorskite and montmorillonite) stabilized the dye and prevented its degradation. Interestingly, in the clay-dye complexes that exhibited stability, clear metachromasy of the adsorbed methylene blue occurred, whereas the effect was not observed in the clay-dye complexes that underwent photodegradation. PMID:23474529

  19. The antimicrobial properties of light-activated polymers containing methylene blue and gold nanoparticles.

    PubMed

    Perni, Stefano; Piccirillo, Clara; Pratten, Jonathan; Prokopovich, Polina; Chrzanowski, Wojciech; Parkin, Ivan P; Wilson, Michael

    2009-01-01

    We report the formation of polysiloxane polymers containing embedded methylene blue and gold nanoparticles incorporated by a swell-encapsulation-shrink method. These polymers show significant antimicrobial activity against methicillin-resistant Staphylococcus aureus and Escherichia coli with up to a 3.5 log(10) reduction in the viable count when exposed for 5 min to light from a low power 660 nm laser. The bacterial kill is due to the light-induced production of singlet oxygen and other reactive oxygen species by the methylene blue. Interestingly, the presence of 2 nm gold nanoparticles significantly enhanced the ability of the methylene blue to kill bacteria. PMID:18838166

  20. Use of methylene blue for catecholamine-refractory vasoplegia from protamine and aprotinin.

    PubMed

    Del Duca, Danny; Sheth, Shashank S; Clarke, Ann E; Lachapelle, Kevin J; Ergina, Patrick L

    2009-02-01

    We present two cases of catecholamine-refractory and vasopressin-refractory vasoplegic syndrome associated with intraoperative anaphylaxis during cardiac surgery. One case was related to the administration of protamine and the other case to the administration of aprotinin. Both cases were successfully managed using intravenous methylene blue. The use of methylene blue blocks accumulation of cyclic guanosine monophosphate by competitively inhibiting the enzyme guanylate cyclase. This results in reduced responsiveness of the vasculature to cyclic guanosine monophosphate-mediated vasodilators, such as nitric oxide. This report provides a description of severe anaphylaxis induced by different agents, in which the use of methylene blue was associated with a significant clinical response. PMID:19161806

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

    PubMed

    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. PMID:19819072

  2. Pyridine Group-Assisted Addition of Diazo-Compounds to Imines in the 3-CC Reaction of 2-Aminopyridines, Aldehydes, and Diazo-Compounds

    PubMed Central

    Gulevich, Anton V.; Helan, Victoria; Wink, Donald J.

    2013-01-01

    A novel three-component (3-CC) coupling reaction of 2-aminoazines, aromatic aldehydes and diazo-compounds producing polyfunctional β-amino-α-diazo-compounds has been developed. The reaction features an unprecedented heterocycle-assisted addition of a diazo-compound to an imine. The obtained diazoesters were efficiently converted into valuable heterocycles, as well as to β-amino acid derivatives. PMID:23373731

  3. Mechanisms of Methylene Blue Degradation in Three-dimensionally Integrated Micro-solution Plasma

    NASA Astrophysics Data System (ADS)

    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. Magnetite/Polymer Brush Nanocomposites with Switchable Uptake Behavior Toward Methylene Blue.

    PubMed

    Dolatkhah, Asghar; Wilson, Lee D

    2016-03-01

    The grafting from approach was used to prepare pH-responsive polyacid brushes using poly(itaconic acid) (PIA) and poly(acrylic acid) (PAA) at the amine functional groups of chitosan. Hybrid materials consisting of polymer brushes and magnetite nanoparticles (MNPs) were also prepared. The products were structurally characterized and displayed reversible pH-responsive behavior and controlled adsorption/desorption of methylene blue (MB). Switchable binding of MB involves cooperative effects due to conformational changes of brushes and swelling phenomena in solution which arise from response to changes in pH. Above the pKa, magnetic nanocomposites (MNCs) are deprotonated and display enhanced electrostatic interactions with high MB removal efficiency (>99%). Below the pKa, MNCs undergo self-assembly and release the cationic dye. The switchable binding of MB and the structure of the polymer brush between collapsed and extended forms relate to changes in osmotic pressure due to reversible ionization of acid groups at variable pH. Reversible adsorption-desorption with variable binding affinity and regeneration ability was demonstrated after five cycles. PMID:26751742

  5. Green synthesis of halloysite nanotubes supported Ag nanoparticles for photocatalytic decomposition of methylene blue

    NASA Astrophysics Data System (ADS)

    Zou, MeiLing; Du, MingLiang; Zhu, Han; Xu, CongSheng; Fu, YaQin

    2012-08-01

    Using tea polyphenols (TPs) as a reductant, Ag nanoparticles (AgNPs) supported on halloysite nanotubes (HNTs) were simply and greenly synthesized for the photocatalytic decomposition of methylene blue (MB). HNTs were initially functionalized by N-β-aminoethyl-γ-aminopropyl trimethoxysilane (AEAPTMS) to introduce amino groups to form N-HNTs to fasten the AgNPs; then AgNPs were synthesized and ‘anchored’ on the surface of the HNTs. Fourier transform infrared spectroscopy was employed to testify the amino groups on the surface of the HNTs. Transmission electron microscopy, field-emission scanning electron microscopy and x-ray diffraction were utilized to characterize the structure and morphology of the synthesized HNTs supported by the AgNPs (AgNPs@N-HNTs). The results showed that the AgNPs had been synthesized and ‘anchored’ onto the surface of the HNTs with a diameter of about 20-30 nm. X-ray photoelectron spectroscopy analysis revealed the chelating interaction between the AgNPs and N atoms together with the TP molecular. The photocatalytic activity of the as-prepared AgNPs@N-HNTs catalyst was evaluated by decomposition of MB; the results showed that the prepared catalyst exhibited excellent catalytic activity and high adsorption capability to MB.

  6. Spectroscopic Study of CpG Alternating DNA-Methylene Blue Interaction for Methylation Detection.

    PubMed

    Hosseini, Morteza; Khaki, Fereshteh; Dadmehr, Mehdi; Ganjali, Mohammad Reza

    2016-05-01

    Recognition of methylated DNA sites would be useful strategy due to the important roles of methylation in disease occurrence and developmental processes. The interaction of CpG rich methylated and unmethylated DNA hybrid with methylene blue (MB) as an optical probe has been investigated by absorption, emission, circular dichorism and fluorescence anisotropy analysis. Titration of MB with both sequences caused a hypsochromism and decreased the absorption of MB that indicating an intercalative mode of interaction. The experimental results revealed that MB as the optical indicator could distinguish between the methylated and unmethylated DNA sequences. Under optimum conditions, upon the addition of methylated dsDNA, the fluorescence intensity increased in linear range from 1.0 × 10(-9) to 1.0 × 10(-6) M with detection limit of 7.2 × 10(-10) M and on the other hand, the intensity of MB showed no change with addition of unmethylated dsDNA. PMID:27048226

  7. Amended safety assessment of formaldehyde and methylene glycol as used in cosmetics.

    PubMed

    Boyer, Ivan J; Heldreth, Bart; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2013-01-01

    Formaldehyde and methylene glycol may be used safely in cosmetics if established limits are not exceeded and are safe for use in nail hardeners in the present practices of use and concentration, which include instructions to avoid skin contact. In hair-smoothing products, however, in the present practices of use and concentration, formaldehyde and methylene glycol are unsafe. Methylene glycol is continuously converted to formaldehyde, and vice versa, even at equilibrium, which can be easily shifted by heating, drying, and other conditions to increase the amount of formaldehyde. This rapid, reversible formaldehyde/methylene glycol equilibrium is distinguished from the slow, irreversible release of formaldehyde resulting from the so-called formaldehyde releaser preservatives, which are not addressed in this safety assessment (formaldehyde releasers may continue to be safely used in cosmetics at the levels established in their individual Cosmetic Ingredient Review safety assessments). PMID:24335968

  8. Methylene chloride exposure and birthweight in Monroe County, New York

    SciTech Connect

    Bell, B.P.; Franks, P.; Hildreth, N.; Melius, J. )

    1991-06-01

    This study examined the relationship between birthweight and exposure to emissions of methylene chloride (DCM) from manufacturing processes of the Eastman Kodak Company at Kodak Park in Rochester, Monroe County, New York. County census tracts were categorized as exposed to high, moderate, low or no DCM based on the Kodak Air Monitoring Program (KAMP) model, a theoretical dispersion model of DCM developed by Eastman Kodak Company. Birthweight and information on variables known to influence birthweight were obtained from 91,302 birth certificates of white singleton births to Monroe County residents from 1976 to 1987. No significant adverse effects of exposure to DCM on birthweight were found. Adjusted birthweight in high exposure census tracts was 18.7 g less than in areas with no exposure (95% confidence interval for the difference between high and no exposure - 51.6, 14.2 g). Problems inherent in the method of estimation of exposure, which may decrease power or bias the results, are discussed. Better methods to estimate exposure to emissions from multiple industrial point sources are needed.

  9. Methylene Blue for Acute Septic Cardiomyopathy in a Burned Patient.

    PubMed

    Schlesinger, Joseph J; Burger, Christina F

    2016-01-01

    The objective of this case summary was to describe the use of methylene blue (MB) in a burned patient with acute septic cardiomyopathy. A 60-year-old Caucasian man was admitted to the Burn Intensive Care Unit with 45% TBSA burns after a house explosion. During the course of his care, he experienced hypotension that was refractory to fluid therapy and vasoactive medications. Echocardiography and right heart catheterization showed new acute systolic dysfunction with concurrent elevated systemic vascular resistance (SVR). High-dose inotropic agents did not improve cardiac function, and septic shock rendered him a poor candidate for mechanical intra-aortic balloon pump support. MB was administered to sensitize the myocardium to catecholamines and improve contractility with the goal of weaning the other vasoactive medications and diuresing for afterload reduction when hemodynamic stability was achieved. MB has been described in critical care medicine predominately for vasoplegia after cardiopulmonary bypass and vasodilatory septic shock., Our patient had acute septic cardiomyopathy that was refractory to standard pharmacologic approaches to inotropy with concurrent elevated SVR. Hypothesizing the differential temporal effect of inducible nitric oxide synthase on the vasculature and myocardium, we administered MB to improve contractility and support the impending vasodilatory effects of distributive shock. Although MB is not a new drug, the application for septic cardiomyopathy with a supranormal SVR is a unique application. Because of the risk profile associated with MB, we recommend drug monitoring utilizing serial echocardiography and/or right heart catheterization. PMID:25798807

  10. [Adsorption of methylene blue onto vanadium-doped magnetite].

    PubMed

    Zhong, Yuan-Hong; Liang, Xiao-Liang; Zhu, Jian-Xi; He, Hong-Ping; Yuan, Peng

    2010-06-01

    A series of vanadium-doped magnetite (Fe3-x VxO4, x < 0.4) synthesized by an oxidation-precipitation method, were characterized using chemical analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetric and differential scanning calorimetry (TG-DSC) analyses. The obtained results show that the synthetic Fe3-x VxO4 has spinel structure while vanadium mostly replaces Fe3+ in the octahedral sites. The synthetic Fe3-x VxO4 is magnetic material, with crystal size ranging from 28 to 35 nm. The substitution of vanadium in the magnetite structure increases the amount of surface hydroxyls. The experimental adsorption results indicate that, in neutral pH condition, the maximum adsorption capacities of Fe3-x VxO4 increase obviously with the increase of vanadium concentration in magnetite while the adsorption isotherm complies well with the Langmuir model. The adsorption of methylene blue (MB) on Fe3-x VxO4 can get equilibrium in the first 25 min, supporting a pseudo-second order equation. Moreover, the rise of the solution pH value results in an increase of the adsorption capability of MB on Fe3-x VxO4. PMID:20698274

  11. A Novel Use of Methylene Blue in the Pediatric ICU.

    PubMed

    Rutledge, Chrystal; Brown, Brian; Benner, Kimberley; Prabhakaran, Priya; Hayes, Leslie

    2015-10-01

    Methylene blue (MB) is a medication commonly used to treat methemoglobinemia, reducing methemoglobin to hemoglobin. A novel use of MB, as detailed here, is in the treatment of refractory hypotension. A number of reports have detailed use of MB for this purpose in adults, but few data in pediatrics. A 22-month-old girl with Noonan syndrome, biventricular hypertrophic cardiomyopathy, and chronic positive pressure ventilation developed shock with tachycardia, hypotension, and fever after 3 days of diarrhea. She was critically ill, with warm extremities, bounding pulses, and brisk capillary refill. Laboratory tests revealed metabolic acidosis, low mixed venous oxygen saturation, and leukocytosis with bandemia. Treatment of severe septic shock was initiated with fluid resuscitation, inotropic support, sedation, and paralysis. She remained hypotensive despite norepinephrine at 0.7 μg/kg per minute, dopamine at 20 μg/kg per minute, and vasopressin at 0.04 U/kg per hour. Her vasoplegic shock worsened, despite aggressive conventional therapy. Intravenous MB was initiated, with a loading dose of 1 mg/kg followed by a continuous infusion at 0.25 mg/kg per hour. Upon initiation of MB, her systolic blood pressure increased by 33 points (40% increase), and diastolic blood pressure increased by 20 points (46% increase). She was able to wean off all inotropes quickly after initiation of MB. MB should be considered in the setting of refractory vasoplegic shock in the PICU. PMID:26347436

  12. Degradation of Methylene Blue Using Biologically Synthesized Silver Nanoparticles

    PubMed Central

    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. PMID:24772055

  13. Methylene blue laser therapy for the treatment of chronic maxillary sinusitis

    NASA Astrophysics Data System (ADS)

    Bashkatov, Alexey N.; Genina, Elina A.; Tuchin, Valery V.; Chikina, Elena E.; Knyazev, Anatoly B.; Mareev, Oleg V.

    2005-08-01

    The clinical results of photodynamic therapy of chronic maxillary sinusitis have been demonstrated. Obtained results show that the photodynamic therapy is effective in comparison with conservative methods of treatment of the disease. Diffusion of Methylene Blue in the mucous tissue has been studied in vitro and value of the diffusion coefficient of Methylene Blue in the tissue has been estimated at 20°C as (4.8+/-2.9)×10-7 cm2/sec.

  14. Fluorescent hybrid with electron acceptor methylene viologen units inside the pore walls of mesoporous MCM-48 silica.

    PubMed

    Liu, Aifeng; Han, Shuhua; Che, Hongwei; Hua, Lan

    2010-03-01

    A fluorescent material with methylene viologen units bonded into the pore walls of the mesoporous MCM-48 silica is synthesized using the method of periodic mesoporous organosilicas with bridging groups (PMOs), in which the methylene viologen units are located within the channel walls through the cohydrolysis and cocondensation of dichloride of N,N'-bis(triethoxysilylmethyl)-4,4'-bipyridinium (VP) and tetraethoxysilane (TEOS). It is found that the suspension of the hybrid emits fluorescence at ca. 380 and 420 nm, which is attributed to the S(1) state (pi* --> pi) of the viologen and the charge-transfer complex between the bipyridinium units as electron acceptor and accompanying halide (Br(-), Cl(-)) as donor components, respectively. The fluorescent emission intensity increases with increasing the amount of the VP covalently bonded to MCM-48 framework. The fluorescent intensity of VP adsorbed on the surface of the pore channel of MCM-48 was greatly weaker than that of the hybrid MCM-48-VP at the same molar ratio of TEOS to VP. No fluorescence was observed for pure VP. The different fluorescent intensity is ascribed to the fact that restricted degree of the rotation between two pyridine rings is different. It could be prospected that this material is potentially applied in drug delivery and fluorescence probing for medical diagnosis and synchronous therapy. PMID:20104919

  15. Methylene blue degradation by NaTaO3 sol-gel doped with Sm and La.

    PubMed

    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. PMID:19042087

  16. Exploring Coordination Modes: Late Transition Metal Complexes with a Methylene-bridged Macrocyclic Tetra-NHC Ligand.

    PubMed

    Altmann, Philipp J; Weiss, Daniel T; Jandl, Christian; Kühn, Fritz E

    2016-05-20

    A tetranuclear silver(I) N-heterocyclic carbene (NHC) complex bearing a macrocyclic, exclusively methylene-bridged, tetracarbene ligand was synthesized and employed as transmetalation agent for the synthesis of nickel(II), palladium(II), platinum(II), and gold(I) derivatives. The transition metal complexes exhibit different coordination geometries, the coinage metals being bound in a linear fashion forming molecular box-type complexes, whereas the group 10 metals adapt an almost ideal square planar coordination geometry within the ligand's cavity, resulting in saddle-shaped complexes. Both the Ag(I) and the Au(I) complexes show ligand-induced metal-metal contacts, causing photoluminescence in the blue region for the gold complex. Distinct metal-dependent differences of the coordination behavior between the group 10 transition metals were elucidated by low-temperature NMR spectroscopy and DFT calculations. PMID:27017146

  17. Effects of silver and group 2 fluorides addition to plasma sprayed chromium carbide high temperature solid lubricant for foil gas bearing to 650 deg C

    NASA Technical Reports Server (NTRS)

    Wagner, R. C.; Sliney, H. E.

    1984-01-01

    A new self-lubricating coating composition of nickel aluminide-bonded chromium carbide formulated with silver and Group II fluorides was developed in a research program on high temperature solid lubricants. One of the proposed applications for this new coating composition is as a wide temperature spectrum solid lubricant for complaint foil gas bearings. Friction and wear properties were obtained using a foil gas bearing start/stop apparatus at temperatures from 25 to 650 C. The journals were Inconel 718. Some were coated with the plasma sprayed experimental coating, others with unmodified nickel aluminide/chromium carbide as a baseline for comparison. The addtitional components were provided to assist in achieving low friction over the temperature range of interest. Uncoated, preoxidized Inconel X-750 foil bearings were operated against these surfaces. The foils were subjected to repeated start/stop cycles under a 14-kPa (2-psi) bearing unit loading. Sliding contact occurred during lift-off and coastdown at surface velocities less than 6 m/s (3000 rpm). Testing continued until 9000 start/stop cycles were accumulated or until a rise in starting torque indicated the journal/bearing had failed. Comparison in coating performance as well as discussions of their properties and methods of application are given.

  18. A preliminary study of extraction solvents for CW-agents and their decomposition products [3:1 (methylene chloride:isopropanol) vs. methylene chloride

    SciTech Connect

    Alcaraz, A.; Ward, R.L.; Hulsey, S.S.; Andresen, B.D.

    1994-09-15

    The major focus of this study was to explore the possibility of using different extraction solvents (or solvent combinations) to isolate CW agents and their degradation products from environmental and industrial samples. The general approach for extracting, e.g. water samples, required the use of a 3:1 (methylene chloride:isopropanol) extraction solvent. Although the 3:1 solvent extraction work-up methods provided excellent results in several Inter-laboratory Comparison Tests, the implementation of these methods for CW on-site analysis exercises was difficult (the methods require cumbersome equipment and are labor intensive). However, due to the time, power, and size restraints set forth by the Chemical Warfare Convention (CWC) for a CW on-site inspection, LLNL developed new sample work-up methods. The approach selected by LLNL incorporated solid phase extraction (SPE) techniques. It is evident from this preliminary study that new or previously used extraction solvents should be re-investigated. It was determined that care must be taken in handling the samples prior to NMR measurements. Also, it was determined that the four target compounds used in this study were extracted on average 18% higher with 3:1 (CH{sub 2}Cl{sub 2}: IPA) vs. CH{sub 2}Cl{sub 2}. However, additional target compounds need to be investigated using this extraction solvent to determine which classes of compounds are better extracted by the use of a 3:1 solvent system. This preliminary study clearly reveals that a mixed solvent system can yield better extraction efficiencies for mixture of compounds in aqueous samples.

  19. Additional mutations in SRSF2, ASXL1 and/or RUNX1 identify a high-risk group of patients with KIT D816V(+) advanced systemic mastocytosis.

    PubMed

    Jawhar, M; Schwaab, J; Schnittger, S; Meggendorfer, M; Pfirrmann, M; Sotlar, K; Horny, H-P; Metzgeroth, G; Kluger, S; Naumann, N; Haferlach, C; Haferlach, T; Valent, P; Hofmann, W-K; Fabarius, A; Cross, N C P; Reiter, A

    2016-01-01

    Most patients with KIT D816V(+) advanced systemic mastocytosis (SM) are characterized by somatic mutations in additional genes. We sought to clarify the prognostic impact of such mutations. Genotype and clinical characteristics of 70 multi-mutated KIT D816V(+) advanced SM patients were included in univariate and multivariate analyses. The most frequently identified mutated genes were TET2 (n=33 of 70 patients), SRSF2 (n=30), ASXL1 (n=20), RUNX1 (n=16) and JAK2 (n=11). In univariate analysis, overall survival (OS) was adversely influenced by mutations in SRSF2 (P<0.0001), ASXL1 (P=0.002) and RUNX1 (P=0.03), but was not influenced by mutations in TET2 or JAK2. In multivariate analysis, SRSF2 and ASXL1 remained the most predictive adverse indicators concerning OS. Furthermore, we found that inferior OS and adverse clinical characteristics were significantly influenced by the number of mutated genes in the SRSF2/ASXL1/RUNX1 (S/A/R) panel (P<0.0001). In conclusion, the presence and number of mutated genes within the S/A/R panel are adversely associated with advanced disease and poor survival in KIT D816V(+) SM. On the basis of these findings, inclusion of molecular markers should be considered in upcoming prognostic scoring systems for patients with SM. PMID:26464169

  20. A randomized placebo-controlled trial of intradiscal methylene blue injection for the treatment of chronic discogenic low back pain.

    PubMed

    Peng, Baogan; Pang, Xiaodong; Wu, Ye; Zhao, Changcheng; Song, Xinghua

    2010-04-01

    A preliminary report of clinical study revealed that chronic discogenic low back pain could be treated by intradiscal methylene blue (MB) injection. We investigated the effect of intradiscal MB injection for the treatment of chronic discogenic low back pain in a randomized placebo-controlled trial. We recruited 136 patients who were found potentially eligible after clinical examination and 72 became eligible after discography. All the patients had discogenic low back pain lasting longer than 6 months, with no comorbidity. Thirty-six were allocated to intradiscal MB injection and 36 to placebo treatment. The principal criteria to judge the effectiveness included alleviation of pain, assessed by a 101-point numerical rating scale (NRS-101), and improvement in disability, as assessed with the Oswestry Disability Index (ODI) for functional recovery. At the 24-month follow-up, both the groups differed substantially with respect to the primary outcomes. The patients in MB injection group showed a mean reduction in pain measured by NRS of 52.50, a mean reduction in Oswestry disability scores of 35.58, and satisfaction rates of 91.6%, compared with 0.70%, 1.68%, and 14.3%, respectively, in placebo treatment group (p<0.001, p<0.001, and p<0.001, respectively). No adverse effects or complications were found in the group of patients treated with intradiscal MB injection. The current clinical trial indicates that the injection of methylene blue into the painful disc is a safe, effective and minimally invasive method for the treatment of intractable and incapacitating discogenic low back pain. PMID:20167430

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

    NASA Astrophysics Data System (ADS)

    Milosevic, Maja; Kaludjerovic, Lazar; Logar, Mihovil

    2016-04-01

    minerals can be distinguished by application of at least three concentrations of the methylene blue dye on the same sample and observing the color change in comparison with standardized color chips that can be easily obtained and free of charge. If the color tests are properly used in conjunction with other more complex analytical procedures, they can be helpful addition in identification of different clay minerals, especially montmorillonite and kaolinite minerals. - Faust G. T., 1940, Staining of clay minerals as a rapid means of identification in natural and beneficiated products, U. S. Bur. Mines, Investigation Report. N0.3522 - Munsell Color, Munsell Book of Color, 1942. Macbeth Division of Kollmorgen Corporation, Maryland, U.S.A. - https://color.adobe.com/create/color-wheel/ - http://www.colorhexa.com/

  2. Porphyrin-Alkaline Earth MOFs with the Highest Adsorption Capacity for Methylene Blue.

    PubMed

    Hou, Yuxia; Sun, Junshan; Zhang, Daopeng; Qi, Dongdong; Jiang, Jianzhuang

    2016-04-25

    A series of four porphyrin-alkaline earth metal- organic frameworks [Mg(HDCPP)2 (DMF)2 ]n ⋅(H2 O)7 n (1), [Ca(HDCPP)2 (H2 O)2 ]n (DMF)1.5 n (2), [Sr(DCPP)(H2 O)(DMA)]n (3), and [Ba(DCPP)(H2 O)(DMA)]n (4) was isolated for the first time from solvothermal reaction between metal-free 5,15-di(4- carboxyphenyl)porphyrin (H2 DCPP) and alkaline earth ions. Single-crystal X-ray diffraction analysis reveals the 2D and 3D supramolecular network with periodic nanosized porosity for 1/2 and 3/4, respectively. The whole series of MOFs, in particular, compounds 1 and 2 with intrinsic low molecular formula weight, exhibit superior adsorption performance for methylene blue (MB) with excellent capture capacity as represented by the thus far highest adsorption amount of 952 mg g(-1) for 2 and good selectivity, opening a new way for the potential application of the main group metal-based MOFs. PMID:27002679

  3. Intradiscal methylene blue injection for the treatment of chronic discogenic low back pain.

    PubMed

    Peng, Baogan; Zhang, Yingmin; Hou, Shuxun; Wu, Wenwen; Fu, Xiaobing

    2007-01-01

    This article was a preliminary report of prospective clinical trial of a group of patients with chronic discogenic low back pain who met the criteria for lumbar interbody fusion surgery but were treated instead with an intradiscal injection of methylene blue (MB) for the pain relief. Twenty-four patients with chronic discogenic low back pain underwent diagnostic discography with intradiscal injection of MB. The principal criteria to judge the effectiveness included alleviation of pain, assessed by visual analog scale (VAS), and improvement in disability, as assessed with the Oswestry Disability Index (ODI) for functional recovery. The mean follow-up period was 18.2 months (range 12-23 months). Of the 24 patients, 21 (87%) reported a disappearance or marked alleviation of low back pain, and experienced a definite improvement in physical function. A statistically significant and clinically meaningful improvement in the changes in the ODI and the VAS scores were obtained in the patients with chronic discogenic low back pain (P=0.0001) after the treatment. The study suggests that the injection of MB into the painful disc may be a very effective alternative for the surgical treatment of chronic discogenic low back pain. PMID:16496191

  4. Methylene blue covalently loaded polyacrylamide nanoparticles for enhanced tumor-targeted photodynamic therapy†

    PubMed Central

    Qin, Ming; Hah, Hoe Jin; Kim, Gwangseong; Nie, Guochao; Lee, Yong-Eun Koo

    2013-01-01

    The use of targeted nanoparticles (NPs) as a platform for loading photosensitizers enables selective accumulation of the photosensitizers in the tumor area, while maintaining their photodynamic therapy (PDT) effectiveness. Here two novel kinds of methylene blue (MB)-conjugated polyacrylamide (PAA) nanoparticles, MBI-PAA NPs and MBII-PAA NPs, based on two separate MB derivatives, are developed for PDT. This covalent conjugation with the NPs (i) improves the loading of MB, (ii) prevents any leaching of MB from the NPs and (iii) protects the MB from the effects of enzymes in the biological environment. The loading of MB into these two kinds of NPs was controlled by the input amount, resulting in concentrations with optimal singlet oxygen production. For each of the MB-NPs, the highest singlet oxygen production was found for an MB loading of around 11 nmol mg−1. After attachment of F3 peptide groups, for targeting, each of these NPs was taken up, selectively, by MDA-MB-435 tumor cells, in vitro. PDT tests demonstrated that both kinds of targeted NPs resulted in effective tumor cell kill, following illumination, while not causing dark toxicity. PMID:21479315

  5. Influence of functional groups on organic aerosol cloud condensation nucleus activity.

    PubMed

    Suda, Sarah R; Petters, Markus D; Yeh, Geoffrey K; Strollo, Christen; Matsunaga, Aiko; Faulhaber, Annelise; Ziemann, Paul J; Prenni, Anthony J; Carrico, Christian M; Sullivan, Ryan C; Kreidenweis, Sonia M

    2014-09-01

    Organic aerosols in the atmosphere are composed of a wide variety of species, reflecting the multitude of sources and growth processes of these particles. Especially challenging is predicting how these particles act as cloud condensation nuclei (CCN). Previous studies have characterized the CCN efficiency for organic compounds in terms of a hygroscopicity parameter, κ. Here we extend these studies by systematically testing the influence of the number and location of molecular functional groups on the hygroscopicity of organic aerosols. Organic compounds synthesized via gas-phase and liquid-phase reactions were characterized by high-performance liquid chromatography coupled with scanning flow CCN analysis and thermal desorption particle beam mass spectrometry. These experiments quantified changes in κ with the addition of one or more functional groups to otherwise similar molecules. The increase in κ per group decreased in the following order: hydroxyl ≫ carboxyl > hydroperoxide > nitrate ≫ methylene (where nitrate and methylene produced negative effects, and hydroperoxide and nitrate groups produced the smallest absolute effects). Our results contribute to a mechanistic understanding of chemical aging and will help guide input and parametrization choices in models relying on simplified treatments such as the atomic oxygen:carbon ratio to predict the evolution of organic aerosol hygroscopicity. PMID:25118824

  6. Methylene blue provides behavioral and metabolic neuroprotection against optic neuropathy.

    PubMed

    Rojas, Julio C; John, Joseph M; Lee, Jung; Gonzalez-Lima, F

    2009-04-01

    Methylene blue (MB) is a diaminophenothiazine with potent antioxidant and unique redox properties that prevent morphologic degenerative changes in the mouse retina induced by rotenone, a specific mitochondrial complex I inhibitor. This study evaluated pigmented rats to determine whether MB's neuroprotective effects against rotenone-mediated retinal neurotoxicity have functional relevance and whether these effects are mediated by an improvement in neuronal energy metabolism in vivo. Visual function was behaviorally assessed by determining differences in the illuminance sensitivity threshold pre- and post-bilateral intravitreal injection of rotenone (200 microg/kg) or rotenone plus MB (70 microg/kg). Retinal degeneration was morphologically studied using unbiased stereological tools. Changes in histochemically determined cytochrome oxidase activity in the visual pathway were used to evaluate the impact of treatments on neuronal energy metabolism. Rotenone induced a 1.4 log unit increase in the illumination threshold compared to baseline, as well as a 32% decrease in ganglion cell layer cell (GCL) density, and a 56% decrease in GCL layer + nerve fiber layer thickness. Co-administration of MB prevented the changes in visual function and the retinal histopathology. Furthermore, rotenone induced a functional deafferentation of the visual system, as revealed by decreases in the metabolic activity of the retina, superior colliculus, and visual cortex. These metabolic changes were also prevented by MB. The results provided the first demonstration of MB's behavioral and metabolic neuroprotection against optic neuropathy, and implicate MB as a candidate neuroprotective agent with metabolic-enhancing properties that may be used in the treatment of neurodegenerative diseases associated with mitochondrial dysfunction. PMID:19384599

  7. Heterogeneous photodegradation of methylene blue with iron and tea or coffee polyphenols in aqueous solutions.

    PubMed

    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. PMID:27120642

  8. Effects of the oxidation degree of graphene oxide on the adsorption of methylene blue.

    PubMed

    Yan, Han; Tao, Xue; Yang, Zhen; Li, Kun; Yang, Hu; Li, Aimin; Cheng, Rongshi

    2014-03-15

    In this current work, a series of graphene oxides (GO) with different oxidation degrees (OD) was prepared using Hummer method. Fundamental adsorption behavior of the GO series for removal of methylene blue (MB) from aqueous solutions has been studied. The GO series shows an overall fast and pH-independent MB adsorption, which is even capable of removing trace levels of dye completely from very dilute solutions. Furthermore, the effects of the oxidation degree (OD) on MB adsorption behavior have been investigated systematically, indicating that the dye uptakes of GO exponentially increase with the increase of OD. Further study on the adsorption mechanism shows that adsorption behavior of GO would change from a Freundlich-type to a Langmuir-type adsorption as the OD increases. It may be due to both the enhanced exfoliation degree of the carbon planes in graphite caused by oxidation and the production of more active adsorption sites. The binding features of the MB loaded GO gradually change from MB molecule parallel stacking on graphite plane through hydrophobic π-π interaction to vertical standing via electrostatic interaction with increasing OD, resulting in a significant improvement of MB uptakes. In addition, the adsorption capacity of the regenerated GO has little loss until four cycles. PMID:24491443

  9. Inhibition of postsurgical adhesions by methylene blue-loaded nanofibers versus cast film matrices.

    PubMed

    El-Sayed, Nesma; Galal, Sally; El-Gowelli, Hanan; El-Khordagui, Labiba

    2016-07-01

    In the quest for barrier membranes for the prevention of post-surgical tissue adhesions, polymer matrices may provide a platform of biomaterials with versatile properties. However, the relationship between the anti-adhesion effects of different polymer matrices and their physicochemical and structural properties is not yet adequately understood. In a preclinical study using a rat cecum model, we directly compared the anti-adhesion potential of polyhydroxybutyrate (PHB) electrospun nanofibrous versus cast film matrices loaded with methylene blue (MB) as antioxidant adhesion inhibitor. PHB retained MB presumably forming MB-bioactivated matrices. In the preclinical study, quantitative morphologic assessment in addition to histopathologic and SEM examinations 14 days post-surgery indicated that plain PHB NFs and MB-PHB NFs, moderately enhanced cecal wall healing and inhibited adhesion formation. In contrast, reshaping PHB as cast films, significantly enhanced healing, reduced adhesion bands and prevented inter-visceral adhesions. Cast films also inhibited tissue attachment to the matrix recovered 14 days post-surgery. Both PHB matrix types reduced tissue inflammation. Despite tissue anti-adhesion potential of individual matrix components, modulation of the micro-architectural properties generated polymer barriers with varying tissue anti-adhesion and healing potentials, the MB-loaded cast film achieving the best outcome. PMID:27093975

  10. Influence of multidrug efflux systems on methylene blue-mediated photodynamic inactivation of Candida albicans

    PubMed Central

    Prates, Renato A.; Kato, Ilka T.; Ribeiro, Martha S.; Tegos, George P.; Hamblin, Michael R.

    2011-01-01

    Objectives To investigate whether the major fungal multidrug efflux systems (MESs) affect the efficiency of methylene blue (MB)-mediated antimicrobial photodynamic inactivation (APDI) in pathogenic fungi and test specific inhibitors of these efflux systems to potentiate APDI. Methods Candida albicans wild-type and mutants that overexpressed two classes of MESs [ATP-binding cassette (ABC) and major facilitator superfamily (MFS)] were tested for APDI using MB as the photosensitizer with and without addition of MES inhibitors. The uptake and cytoplasm localization of photosensitizer were achieved using laser confocal microscopy. Results ABC MES overexpression reduced MB accumulation and APDI killing more than MFS MES overexpression. Furthermore, by combining MB APDI with the ABC inhibitor verapamil, fungal killing and MB uptake were potentiated, while by combining MB APDI with the MFS inhibitor INF271, fungal killing and MB uptake were inhibited. This latter surprising finding may be explained by the hypothesis that the MFS channel can also serve as an uptake mechanism for MB. Conclusions The ABC pumps are directly implicated in MB efflux from the cell cytoplasm. Both the influx and efflux of MB may be regulated by MFS systems, and blocking this gate before incubation with MB can decrease the uptake and APDI effects. An ABC inhibitor could be usefully combined with MB APDI for treating C. albicans infections. PMID:21525022

  11. Broadband Transient Absorption and Two-Dimensional Electronic Spectroscopy of Methylene Blue.

    PubMed

    Dean, Jacob C; Rafiq, Shahnawaz; Oblinsky, Daniel G; Cassette, Elsa; Jumper, Chanelle C; Scholes, Gregory D

    2015-08-27

    Broadband transient absorption and two-dimensional electronic spectroscopy (2DES) studies of methylene blue in aqueous solution are reported. By isolating the coherent oscillations of the nonlinear signal amplitude and Fourier transforming with respect to the population time, we analyzed a significant number of coherences in the frequency domain and compared them with predictions of the vibronic spectrum from density function theory (DFT) calculations. We show here that such a comparison enables reliable assignments of vibrational coherences to particular vibrational modes, with their constituent combination bands and overtones also being identified via Franck–Condon analysis aided by DFT. Evaluation of the Fourier transform (FT) spectrum of transient absorption recorded to picosecond population times, in coincidence with 2D oscillation maps that disperse the FT spectrum into the additional excitation axis, is shown to be a complementary approach toward detailed coherence determination. Using the Franck–Condon overlap integrals determined from DFT calculations, we modeled 2D oscillation maps up to two vibrational quanta in the ground and excited state (six-level model), showing agreement with experiment. This semiquantitative analysis is used to interpret the geometry change upon photoexcitation as an expansion of the central sulfur/nitrogen containing ring due to the increased antibonding character in the excited state. PMID:26274093

  12. Methylene blue photosensitised strand cleavage of DNA: effects of dye binding and oxygen.

    PubMed Central

    OhUigin, C; McConnell, D J; Kelly, J M; van der Putten, W J

    1987-01-01

    It is shown that methylene blue (MB+) photosensitises DNA in either aerated or deaerated solutions, causing direct cleavage of phosphodiester bonds and rendering additional bonds labile to alkali. Evidence from unwinding and fluorimetric studies indicates that MB+ binds to DNA in at least 2 ways. Intercalation, which optimally induces helical unwinding of 24 degrees +/- 2 degrees per MB+, is markedly reduced upon neutralisation by Mg2+ of the DNA phosphates, while significant non-intercalative binding persists as shown by substantial fluorescence quenching at Mg2+ concentrations where there is little unwinding. MB+ induces photolysis at both low and high Mg2+ concentration - intercalation is apparently not required for photolysis. The quantum yield for strand breakage varies from 1-3 X 10(-7) under different conditions and is oxygen enhanced. The DNA cleavage is guanine specific. The 3' termini of the primary MB+-induced DNA photoproducts, unlike those generated by chemical sequencing retain an alkali labile adduct on the terminal phosphate. Images PMID:2821508

  13. A sensitive resveratrol assay with a simple probe methylene blue by resonance light scattering technique

    NASA Astrophysics Data System (ADS)

    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. Pump-probe optical coherence tomography using microencapsulated methylene blue as a contrast agent (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kim, Wihan; Zebrowski, Erin; Lopez, Hazel C.; Applegate, Brian E.; Charoenphol, Phapanin; Jo, Javier A.

    2016-03-01

    Molecular contrast imaging can target specific molecules or receptors to provide detailed information on the local biochemistry and yield enhanced visualization of pathological and physiological processes. When paired with Optical Coherence Tomography (OCT) it can simultaneously supply the morphological context for the molecular information. We recently demonstrated in vivo molecular contrast imaging of methylene blue (MB) using a 663 nm diode laser as a pump in a Pump-Probe OCT (PPOCT) system. The simple addition of a dichroic mirror in the sample arm enabled PPOCT imaging with a typical 830-nm band spectral-domain OCT system. Here we report on the development of a microencapsulated MB contrast agent. The poly lactic-co-glycolic acid (PLGA) microspheres loaded with MB offer several advantages over bare MB. The microsphere encapsulation improves the PPOCT signal both by enhancing the scattering and preventing the reduction of MB to leucomethylene blue. The surface of the microsphere can readily be functionalized to enable active targeting of the contrast agent without modifying the excited state dynamics of MB that enable PPOCT imaging. Both MB and PLGA are used clinically. PLGA is FDA approved and used in drug delivery and tissue engineering applications. 2.5 μm diameter microspheres were synthesized with an inner core containing 0.01% (w/v) aqueous MB. As an initial demonstration the MB microspheres were imaged in a 100 μm diameter capillary tube submerged in a 1% intralipid emulsion.

  15. Phase II Study of the Addition of Bevacizumab to Standard Chemoradiation for Loco-regionally Advanced Nasopharyngeal Carcinoma: Radiation Therapy Oncology Group (RTOG) Trial 0615

    PubMed Central

    Lee, Nancy Y.; Zhang, Ed; Pfister, David. G.; Kim, John; Garden, Adam. S.; Mechalakos, James; Hu, Kenneth; Le, Quynh T.; Colevas, A. Dimitrios; Glisson, Bonnie S.; Chan, Anthony T.C.; Ang, K. Kian

    2016-01-01

    Purpose We sought to improve the outcomes for loco-regionally advanced nasopharyngeal carcinoma (NPC) by testing the feasibility/safety of adding bevacizumab to chemoradiation. Patients/Methods Eligible patients with ≥T2b and/or positive node(s) were prescribed 3 cycles of bevacizumab (15 mg/kg) and cisplatin (100 mg/m2) both given on days 1, 22, and 43 of radiation (70 Gy) using IMRT delivered over 33 days on a daily basis, Monday through Friday. This is followed by 3 cycles of bevacizumab (15 mg/kg), cisplatin (80 mg/m2) both were given on days 64, 85, and 106 and fluorouracil (1000 mg/m2/d) on days 64–67, 85–88, 106–109 after radiation. The primary endpoint was to evaluate the safety of the addition of bevacizumab to chemoradiation, specifically looking at treatment-related Grade 4 hemorrhage and/or any Grade 5 adverse event in the first year. Toxicity during and after treatment were collected along with tumor control endpoints. The analysis was done per protocol. This protocol has completed its target accrual. Results There were a total of 46 patients enrolled in this study of whom 44 patients were eligible for analysis. No grade 3–4 hemorrhage or grade 5 adverse events were observed; 9 patients (20.5%) experienced grade 1–2 hemorrhage. Grade 4 adverse events were experienced by the following numbers of patients: leukopenia NOS – 6; lymphopenia – 5; neutrophil count – 5; pharyngolaryngeal pain – 2; hemoglobin – 1; infection with grade 3–4 neutrophils (blood) – 1; infection with grade 3–4 neutrophils [skin (cellulitis)] – 1; tinnitus – 1; thrombosis – 1; radiation mucositis – 1. The most common grade 3 adverse events were radiation mucositis – 33; dysphagia – 25; and mucositis/stomatitis (clinical exam) (pharynx) – 15. Two patients experienced late grade 3 xerostomia. Other late grade 3 adverse events were: dysphagia – 5; hearing impaired – 3; neuralgia NOS – 2; constitutional symptoms (other) – 1; dehydration

  16. Food additives

    MedlinePlus

    Food additives are substances that become part of a food product when they are added during the processing or making of that food. "Direct" food additives are often added during processing to: Add nutrients ...

  17. Dual contractile effects of ATP released by field stimulation revealed by effects of alpha,beta-methylene ATP and suramin in rat tail artery.

    PubMed Central

    Bao, J. X.; Stjärne, L.

    1993-01-01

    1. The field stimulation-induced release of endogenous ATP and noradrenaline (NA) and contractile response in rat isolated tail artery were examined. The release of ATP was studied by extracellular electrophysiological recording and that of NA by a novel voltammetrical technique. The effects of the P2-purinceptor antagonist, suramin, on these parameters were compared with those of alpha,beta-methylene ATP, a P2X-purinoceptor desensitizing agent. 2. Neither alpha,beta-methylene ATP (10 microM) nor suramin (100-500 microM) had significant effects on the extracellularly recorded nerve terminal action potential but both abolished the ATP-induced excitatory junction current caused by stimulation at 0.1 Hz. Neither agent affected significantly the voltammetrically measured release of NA induced by 10 or 100 pulses at 20 Hz. 3. Combined blockade of both postjunctional alpha 1- and alpha 2-adrenoceptors by prazosin and yohimbine (both 0.1 microM) profoundly depressed the contractile response to 10 pulses at 20 Hz. The small and fast residual contraction in the presence of these agents was abolished by alpha,beta-methylene ATP (10 microM) and inhibited by suramin in a concentration-dependent manner (10-500 microM; IC50 75 microM) and was hence probably caused by ATP or a related nucleotide. 4. When added first, alpha,beta-methylene ATP (10 microM) or suramin (100-500 microM) delayed the onset and enhanced the amplitude of the neurogenic contraction. This enhanced response was abolished by further addition of prazosin and yohimbine (both 0.1 microM). 5. The K+ channel blocker, tetraethylammonium (10 mM), dramatically enhanced the contractile response to 100 pulses at 1 Hz and caused it to become diphasic.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8306081

  18. N-acetylcysteine, Ascorbic Acid, and Methylene Blue for the Treatment of Aluminium Phosphide Poisoning: Still Beneficial?

    PubMed Central

    Gheshlaghi, Farzad; Lavasanijou, Mohamad Reza; Moghaddam, Noushin Afshar; Khazaei, Majid; Behjati, Mohaddeseh; Farajzadegan, Ziba; Sabzghabaee, Ali Mohammad

    2015-01-01

    Objectives: Intentional and accidental intoxication with aluminium phosphide (ALP) remains a clinical problem, especially in the Middle East region. Considering the high mortality rate besides lack of any recommended first option drug for its treatment, this study was aimed to compare the therapeutic effects of N-acetylcysteine (NAC), vitamin C (Vit C), and methylene blue; both in isolate and also in combination, for the treatment of ALP intoxication in a rat model. Materials and Methods: In this experimental animal study, 80 male Wistar rats in eight groups were intoxicated with ALP (12.5 mg/kg) and treated with a single dose of NAC (100 mg/kg) or Vit C (500–1,000 mg/kg) or methylene blue (1 mg/kg/5 min, 0.1%) or two of these agents or all three of them (controls were not treated). Rats were monitored regarding the parameters of drug efficacy as increased survival time and reduced morbidity and mortality rate for 3 consecutive days to ensure toxin neutralization. Macroscopic changes were recorded and biopsy sections were taken from brain, cerebellum, kidney, liver, and heart for microscopic evaluation regarding cellular hypoxia. Results: The mean survival times of rats exposed to ALP and treated with VitC + NAC was 210.55±236.22 minutes. In analysis of survival times, there was a significant difference between Group 5 which received VitC + NAC and the other groups (P < 0.01). Serum magnesium levels after death were higher than normal (P = 0.01). Conclusions: Despite the higher survival rate of antioxidant-treated rats compared with controls, this difference was not statistically significant. PMID:26862259

  19. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  20. Polymorphisms in the methylene tetrahydrofolate reductase and methionine synthase reductase genes and their correlation with unexplained recurrent spontaneous abortion susceptibility.

    PubMed

    Zhu, L

    2015-01-01

    We aimed to explore the correlation between unexplained recurrent spontaneous abortion and polymorphisms in the methylene tetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) genes. A case control study was conducted in 118 patients with unexplained recurrent spontaneous abortion (abortion group) and 174 healthy women (control group). The genetic material was extracted from the oral mucosal epithelial cells obtained from all subjects. The samples were subjected to fluorescence quantitative PCR to detect the single nucleotide polymorphisms (SNPs) in the MTHFR (C677T and A1298C) and MTRR (A66G) gene loci. The distribution frequency (18/118, 15.3%) of the MTHFR 677TT genotype was significantly higher in the abortion group (χ2 = 11.006, P = 0.004) than in the control group (2/174, 1.1%); on the other hand, the distribution frequency of the MTHFR A1298C genotype did not significantly differ between the abortion and control groups (χ(2) = 0.441, P = 0.507). The distribution frequency of the MTRR A66G genotype was also significantly higher in the abortion group (14/118, 11.9%; χ(2) = 10.503, P = 0.005) than in the control group (8/174, 4.6%). The MTHFR C677T and MTRR A66G polymorphisms are significantly correlated with the occurrence of spontaneous abortion. PMID:26345779

  1. Orientation and optical properties of methylene blue crystal for better understanding of interactions with clay mineral surface

    NASA Astrophysics Data System (ADS)

    Milošević, Maja; Logar, Mihovil

    2013-04-01

    The properties of cationic dye Methylene blue (MB) adsorbed on diferent surfaces have been investigated intensively over the years and various models for the orientation of its cations have been proposed (Hang and Brindley, 1970; Bujdak et al., 2003; Li and Zare, 2004; Marr III et al., 1973; Bujdak, 2006).The main objective of this work is to investigate and determine orientation and optical properties of metylene blue crystal upon its crystallization on a glass slate and to use those findings in better understanding of interactions with clay minerals. Cationic dyes have very high affinity for clay surfaces and those interactions are easily detected, therefore these dyes are used to determine several properties of clay surfaces (morphology, layer charge, CEC). For this study, we have selected a group of MB crystal and carried out XRD analysis, polarized absorption spectra measurement (400 - 900 nm) and determination of optical properties (pleochroism, determination of twining and extinction angle) using polarizing microscope. Methylene blue crystals are exhibiting mostly needle like habitus with huge difference in width - length ratio. According to X-ray diffraction it is quite obvious that the y (b) axis is perpendicular to the crystal surface. The x (a) and z (c) axis lie in the crystal plane (010). Crystals exhibit prominent dichroism: from blue (E || elong.) to colorless. In accordance with current interpretation of MB spectra peaks at 647 and 570 nm can be assigned as dimer aggregation and peaks at 475 and 406 nm as higher level of aggregation. All of them exhibit pronounced polarization dependence. The group of peaks at lower energy (700 to 900 nm) do not show significant polarization dependence and they correspond to the J - aggregates. Peak at around 800 nm have been noticed as fluorescence active. In dependence with thickness of the crystals and vibration direction we have observed presence of polysynthetic twinning which can be compared with polysynthetic

  2. Complexation between carrageenan and methylene blue for sensor design

    NASA Astrophysics Data System (ADS)

    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

  3. Synthetic method and biological activities of cis-fused alpha-methylene gamma-lactones.

    PubMed

    Higuchi, Yohsuke; Shimoma, Fumito; Ando, Masayoshi

    2003-06-01

    A reliable method was developed for the synthesis of cis-fused alpha-methylene gamma-lactones via alpha-methyl gamma-lactones. Bromination of alpha-methyl gamma-lactones with LDA/CBr(4) or TMSOTf/PTAB and successive dehydrobromination with DBU or TBAF of the resulting alpha-bromo-alpha-methyl gamma-lactones gave the desired alpha-methylene gamma-lactones in high yield. This method was successfully applied to the synthesis of biologically active compounds. alpha-Methylene gamma-lactone derivatives 1c, 2c, 4c, and 17 showed cell growth inhibitory activity to P388 lymphocytic leukemia. They also showed significant activities to crop diseases. Thus, alpha-methylene gamma-lactone 1c showed preventive activity in controlling scab of apple caused by Venturia inaequalis. alpha-Methylene gamma-lactones 2c, 4c, 17, and 18 also showed significant preventive activities in controlling damping off of cucumber caused by Pythium aphanidermatum. PMID:12828467

  4. Application of central composite design for simultaneous removal of methylene blue and Pb2+ ions by walnut wood activated carbon

    NASA Astrophysics Data System (ADS)

    Ghaedi, M.; Mazaheri, H.; Khodadoust, S.; Hajati, S.; Purkait, M. K.

    2015-01-01

    Activated carbon was prepared from walnut wood which was locally available, non-toxic, abundant and cheap. This new adsorbent was characterized using BET, FTIR and SEM. Point of zero charge (pHpzc) and oxygen containing functional groups were also determined. The prepared adsorbent was applied for simultaneous removal of Pb2+ ions and methylene blue (MB) dye from aqueous solution. The prominent effect and interaction of variables such as amount of adsorbent, contact time, concentration of MB and Pb2+ ions were optimized by central composite design. The equilibrium data obtained at optimum condition were fitted to conventional isotherm models and found that Langmuir model was the best fitted isotherm. Kinetic data were fitted using various models. It was revealed that the adsorption rate follows pseudo-second order kinetic model and intraparticle diffusion model.

  5. PBPK modeling/Monte Carlo simulation of methylene chloride kinetic changes in mice in relation to age and acute, subchronic, and chronic inhalation exposure.

    PubMed Central

    Thomas, R S; Yang, R S; Morgan, D G; Moorman, M P; Kermani, H R; Sloane, R A; O'Connor, R W; Adkins, B; Gargas, M L; Andersen, M E

    1996-01-01

    During a 2-year chronic inhalation study on methylene chloride (2000 or 0 ppm; 6 hr/day, 5 days/week), gas-uptake pharmacokinetic studies and tissue partition coefficient determinations were conducted on female B6C3F1, mice after 1 day, 1 month, 1 year, and 2 years of exposure. Using physiologically based pharmacokinetic (PBPK) modeling coupled with Monte Carlo simulation and bootstrap resampling for data analyses, a significant induction in the mixed function oxidase (MFO) rate constant (Vmaxc) was observed at the 1-day and 1-month exposure points when compared to concurrent control mice while decreases in glutathione S-transferase (GST) rate constant (Kfc) were observed in the 1-day and 1-month exposed mice. Within exposure groups, the apparent Vmaxc maintained significant increases in the 1-month and 2-year control groups. Although the same initial increase exists in the exposed group, the 2-year Vmaxc is significantly smaller than the 1-month group (p < 0.001). Within group differences in median Kfc values show a significant decrease in both 1-month and 2-year groups among control and exposed mice (p < 0.001). Although no changes in methylene chloride solubility as a result of prior exposure were observed in blood, muscle, liver, or lung, a marginal decrease in the fat:air partition coefficient was found in the exposed mice at p = 0.053. Age related solubility differences were found in muscle:air, liver:air, lung:air, and fat:air partition coefficients at p < 0.001, while the solubility of methylene chloride in blood was not affected by age (p = 0.461). As a result of this study, we conclude that age and prior exposure to methylene chloride can produce notable changes in disposition and metabolism and may represent important factors in the interpretation for toxicologic data and its application to risk assessment. Images Figure 1. Figure 2. Figure 3. Figure 4. Figure 4. Figure 4. Figure 4. Figure 5. Figure 5. Figure 5. Figure 5. PMID:8875160

  6. Evaluation of Coronal Leakage Following Different Obturation Techniques and in-vitro Evalution Using Methylene Blue Dye Preparation

    PubMed Central

    Mathur, Rachit; Sharma, Medhavi; Sharma, Deepak; Raisingani, Deepak; Vishnoi, Suchita; Singhal, Deepika

    2015-01-01

    Introduction Coronal and apical leakage still remains one of the most important cause for endodontic failure in spite of the presence of advanced endodontic materials. The cause may attribute to different filling techniques, physical and chemical properties of sealers and presence or absence of smear layer assessment of coronal or apical leakage is used as a research method to compare the sealing ability of different techniques and endodontic materials. Aim To compare the coronal bacterial leakage using methylene blue in four different obturation techniques after protaper hand instrumentation. Materials and Methods Ninety extracted single-rooted teeth were instrumented to an apical preparation size F3 Protaper hand files. Twenty teeth were randomly obturated with lateral compaction, 20 with vertical compaction, 20 with combination of vertical and lateral compaction and 20 with Thermafil. Ten teeth were used for positive and negative controls (five teeth in each group). Teeth were kept in 100% humidity for 90 days, and then subjected coronally to Proteus vulgaris for 21 days to assess bacterial leakage. After bacterial challenge, methylene blue was placed coronally for another 21 days, and then scoring was done according to depth of dye leakage. Chi-square test was done for statistical analysis. Results Leakage as observed with combination of vertical and lateral compaction was significantly less than vertical compaction, lateral compaction and thermafil carriers during bacterial challenge. However, when dye was used it also showed statistically significant results with thermafil carriers showing the least leakage in comparison to vertical condensation, lateral condensation and combined groups. Conclusion The study concludes that two different methods i.e. bacterial and dye leakage revealed considerable variation on the same substrate Thus, due to the presence of variability among the results obtained by two different analytical methods used in the present study

  7. Connecting glutathione with immune responses to occupational methylene diphenyl diisocyanate exposure

    PubMed Central

    Wisnewski, Adam V; Liu, Jian; Redlich, Carrie A

    2013-01-01

    Methylene diphenyl diisocyanate (MDI) is among the leading chemical causes of occupational asthma world-wide, however, the mechanisms of disease pathogenesis remain unclear. This study tests the hypothesis that glutathione (GSH) reacts with MDI to form quasistable conjugates, capable of mediating the formation of MDI-conjugated “self” protein antigens, which may participate in pathogenic inflammatory responses. To test this hypothesis, an occupationally relevant dose of MDI (0.1% w/v) was reacted with varying concentrations of GSH (10 μM-10 mM), and the reaction products were characterized with regard to mass/structure, and ability to carbamoylate human albumin, a major carrier protein for MDI in vivo. LC-MS/MS analysis of GSH-MDI reaction products identified products possessing the exact mass of previously described S-linked bis(GSH)-MDI and its partial hydrolysis product, as well as novel cyclized GSH-MDI structures. Upon co-incubation of GSH-MDI reaction products with human albumin, MDI was rapidly transferred to specific lysines of albumin, and the protein's native conformation/charge was altered, based on electrophoretic mobility. Three types of modification were observed, intra-molecular MDI cross-linking, addition of partially hydrolyzed MDI, and addition of “MDI-GSH”, where MDI's 2nd NCO had reacted with GSH's “N-terminus”. Importantly, human albumin carbamoylated by GSH-MDI was specifically recognized by serum IgG from MDI exposed workers, with binding dependent upon the starting GSH concentration, pH, and NaCl levels. Together, the data define a non-enzymatic, thiol-mediated transcarbamoylating mechanism by which GSH may promote immune responses to MDI exposure, and identify specific factors that might further modulate this process. PMID:23791970

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

    PubMed

    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. PMID:26930332

  9. A Study for Health Hazard Evaluation of Methylene Chloride Evaporated from the Tear Gas Mixture

    PubMed Central

    Chung, Eun-Kyo; Yi, Gwang-Yong; Chung, Kwang-Jae; Shin, Jung-Ah; Lee, In-Seop

    2010-01-01

    This study explored the health hazard of those exposed to methylene chloride by assessing its atmospheric concentration when a tear gas mixture was aerially dispersed. The concentration of methylene chloride ranged from 311.1-980.3 ppm (geometric mean, 555.8 ppm), 30 seconds after the dispersion started. However, the concentration fell rapidly to below 10 ppm after dispersion was completed. The concentration during the dispersion did not surpass the National Institute for Occupational Safety and Health 'immediately dangerous to life or health' value of 2,300 ppm, but did exceed the American Conference of Governmental Industrial Hygienists excursion limit of 250 ppm. Since methylene chloride is highly volatile (vapor pressure, 349 mmHg at 20℃), the postdispersion atmospheric concentration can rise instantaneously. Moreover, the o-chlorobenzylidenemalononitrile formulation of tear gas (CS gas) is an acute upper respiratory tract irritant. Therefore, tear gas mixtures should be handled with delicate care. PMID:22953168

  10. Utility of methylene blue for the reversal of excessive levels of methemoglobin

    SciTech Connect

    Vick, J.; Von Bredow, J.; Brown, L.; Kaminskis, A.; Bossone, C.

    1993-05-13

    Many new prophylactic and therapeutic compounds are being studied as potential sources of methemoglobin useful in counteracting the lethal effects of cyanide intoxication. The formation of methemoglobin also leads to a reduction in the blood oxygen carrying capacity which may, in extreme cases, lead to lethal consequences. The i.v. administration of Methylene blue rapidly reverses methemoglobin to hemoglobin. Unanticipated high levels of methemoglobin (65 - 85%) in three sheep exposed to propiophenone derivatives led to a lethal outcome in one untreated sheep and complete recovery in two sheep which were treated with 3.0 mg/kg methylene blue i.v. methemoglobin was reduced to safe levels within minutes following administration. A similar exposure of dogs to propriophenone derivatives led to high levels (77 - 78%) of methemoglobin which were readily reversed following the intravenous administration of the same dose of methylene blue.

  11. Viral Inactivation of Human Osteochondral Grafts with Methylene Blue and Light

    PubMed Central

    Zhao, Zhixing; Call, Gazell M.; Gao, Jizong; Yao, Jian Q.

    2014-01-01

    Objective: Cartilage injury is one of the most common disorders of synovial joints. Fresh osteochondral allografts are becoming a standard treatment; however, they are supply constrained with a potential risk of disease transmission. There are no known virucidal processes available for osteochondral allografts and most methods presently available are detrimental to cartilage. Methylene blue light treatment has been shown to be successful in the literature for viral inactivation of fresh frozen plasma. The purpose of this study was to determine the capacity of methylene blue light treatment to inactivate a panel of clinically relevant viruses inoculated onto osteochondral allografts. Design: Osteochondral grafts recovered from human cadaveric knees were inoculated with one of the following viruses: bovine viral diarrhea virus (BVDV), hepatitis A virus (HAV), human immunodeficiency virus type 1 (HIV-1), porcine parvovirus (PPV), and pseudorabies virus (PrV). The samples were processed through a methylene blue light treatment, which consisted of an initial soak in nonilluminated circulating methylene blue at ambient temperature, followed by light exposure with circulating methylene blue at cool temperatures. The final titer was compared with the recovery control for the viral log reduction. Results: HIV-1, BVDV, and PrV were reduced to nondetectable levels while HAV and PPV were reduced by 3.1 and 5.6 logs, respectively. Conclusions: The methylene blue light treatment was effective in reducing (a) enveloped DNA and RNA viruses to nondetectable levels and (b) nonenveloped DNA and RNA viruses of inoculated human osteochondral grafts by 3.1 to 5.6 logs. This study demonstrates the first practical method for significantly reducing viral load in osteochondral implants. PMID:26069682

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

    PubMed

    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. PMID:27107333

  13. MO-G-18C-07: Improving T2 Determination and Quantification of Lipid Methylene Protons in Proton Magnetic Resonance Spectroscopy at 3 T

    SciTech Connect

    Breitkreutz, D.; Fallone, B. G.; Yahya, A.

    2014-06-15

    Purpose: To improve proton magnetic resonance spectroscopy (MRS) transverse relaxation (T{sub 2}) determination and quantification of lipid methylene chain (1.3 ppm) protons by rewinding their J-coupling evolution. Methods: MRS experiments were performed on four lipid phantoms, namely, almond, corn, sunflower and oleic acid, using a 3 T Philips MRI scanner with a transmit/receive birdcage head coil. Two PRESS (Point RESolved Spectroscopy) pulse sequences were used. The first PRESS sequence employed standard bandwidth (BW) (∼550 Hz) RF (radiofrequency) refocussing pulses, while the second used refocussing pulses of narrow BW (∼50 Hz) designed to rewind J-coupling evolution of the methylene protons in the voxel of interest. Signal was acquired with each sequence from a 5×5×5 mm{sup 3} voxel, with a repetition time (TR) of 3000 ms, and with echo times (TE) of 100 to 200 ms in steps of 20 ms. 2048 sample points were measured with a 2000 Hz sampling bandwidth. Additionally, 30 mm outer volume suppression slabs were used to suppress signal outside the voxel of interest. The frequency of the RF pulses was set to that of the methylene resonance. Methylene peak areas were calculated and fitted in MATLAB to a monexponentially decaying function of the form M{sub 0}exp(-TE/T{sub 2}), where M{sub 0} is the extrapolated area when TE = 0 ms and yields a measure of concentration. Results: The determined values of M{sub 0} and T{sub 2} increased for all fatty acids when using the PRESS sequence with narrow BW refocussing pulses. M{sub 0} and T{sub 2} values increased by an average amount (over all the phantoms) of 31% and 14%, respectively. Conclusion: This investigation has demonstrated that J-coupling interactions of lipid methylene protons causes non-negligible signal losses which, if not accounted for, Result in underestimations of their levels and T{sub 2} values when performing MRS measurements. Funded by the Natural Sciences and Engineering Research Council of Canada

  14. Time resolved spectroscopic studies of methylene blue and phenothiazine derivatives used for bacteria inactivation

    NASA Astrophysics Data System (ADS)

    Chen, Jie; Cesario, Thomas C.; Rentzepis, Peter M.

    2010-09-01

    Phenothiazine dyes are known to inactivate bacteria in whole blood and plasma caused by the singlet oxygen photo generated by these dyes. Methylene blue (MB), 1,9-dimethyl-methylene blue (DMB) and toluidine blue (TB) transient singlet and triplet states spectra and their formation and decay kinetics have been measured by time resolved spectroscopy. The triplet state formation and singlet oxygen quantum yields in water are found to be approximately the same in MB and DMB. Therefore, based on our data we propose that although singlet oxygen is highly important as previously stated, the rate of inactivation is determined by the binding of the dye to the bacteria.

  15. Food additives.

    PubMed

    Berglund, F

    1978-01-01

    The use of additives to food fulfils many purposes, as shown by the index issued by the Codex Committee on Food Additives: Acids, bases and salts; Preservatives, Antioxidants and antioxidant synergists; Anticaking agents; Colours; Emulfifiers; Thickening agents; Flour-treatment agents; Extraction solvents; Carrier solvents; Flavours (synthetic); Flavour enhancers; Non-nutritive sweeteners; Processing aids; Enzyme preparations. Many additives occur naturally in foods, but this does not exclude toxicity at higher levels. Some food additives are nutrients, or even essential nutritents, e.g. NaCl. Examples are known of food additives causing toxicity in man even when used according to regulations, e.g. cobalt in beer. In other instances, poisoning has been due to carry-over, e.g. by nitrate in cheese whey - when used for artificial feed for infants. Poisonings also occur as the result of the permitted substance being added at too high levels, by accident or carelessness, e.g. nitrite in fish. Finally, there are examples of hypersensitivity to food additives, e.g. to tartrazine and other food colours. The toxicological evaluation, based on animal feeding studies, may be complicated by impurities, e.g. orthotoluene-sulfonamide in saccharin; by transformation or disappearance of the additive in food processing in storage, e.g. bisulfite in raisins; by reaction products with food constituents, e.g. formation of ethylurethane from diethyl pyrocarbonate; by metabolic transformation products, e.g. formation in the gut of cyclohexylamine from cyclamate. Metabolic end products may differ in experimental animals and in man: guanylic acid and inosinic acid are metabolized to allantoin in the rat but to uric acid in man. The magnitude of the safety margin in man of the Acceptable Daily Intake (ADI) is not identical to the "safety factor" used when calculating the ADI. The symptoms of Chinese Restaurant Syndrome, although not hazardous, furthermore illustrate that the whole ADI

  16. The effect of addition of low dose fentanyl to epidural bupivacaine (0.5%) in patients undergoing elective caesarean section: A randomized, parallel group, double blind, placebo controlled study

    PubMed Central

    Parate, LH; Manjrekar, SP; Anandaswamy, TC; Manjunath, B

    2015-01-01

    Background: Opioids have synergistic action with local anesthetics which may alter characteristics of epidural block. Giving opioids to mother before delivery of baby is still fully not accepted with some fearing risk of neonatal depression. Aims: Our primary aim was to evaluate the analgesic effect of addition of 50 μg fentanyl to epidural 0.5% bupivacaine in patients undergoing elective caesarean section using visual analog scale. The secondary aim was to assess onset of analgesia, volume of drug required to achieve T6 level, grade and duration of motor block and Apgar score. Materials and Methods: In this prospective, randomized, double blind, placebo controlled study 64 patients scheduled for elective caesarean section under epidural anesthesia were randomly divided into two groups of 32 each. The fentanyl group received 1ml of 50 μg fentanyl and the saline group received 1ml of normal saline mixed with 10ml of 0.5% bupivacaine for epidural anesthesia. VAS score, time to achieve T6 level, dose of bupivacaine, intraoperative analgesic consumption and duration of analgesia, grade and duration of motor block and any adverse maternal and neonatal effects were noted. Statistical Analysis: Data was analyzed using Students t test, chi-square test and Mann-Whitney U-test. The values of P < 0.05 were considered statistically significant. Results: Fentanyl improved the VAS score significantly (1.6 ± 1.32) compared to the saline group (3.77 ± 1.0, P < 0.0001). It also reduced the intraoperaitve analgesic supplementation compared to the saline group. (P = 0.031). The postoperative duration of analgesia was prolonged in the fentanyl group (275.80 ± 13.61 min) compared to the saline group (191.47 ± 12.16 min, P < 0.0001). The other characteristics of epidural block were unaltered. Conclusion: Addition of 50 μg fentanyl to epidural 0.5% bupivacaine significantly reduces the VAS score. It also reduces intra-operative analgesia supplementation and prolongs the duration

  17. Detection of DNA Hybridization by Methylene Blue Electrochemistry at Activated Nanoelectrode Ensembles.

    PubMed

    Silvestrini, Morena; Fruk, Ljiljana; Moretto, Ligia Maria; Ugo, Paolo

    2015-05-01

    Nanoelectrode ensembles (NEEs) obtained by electroless gold deposition in track-etched poly-carbonate (PC) membranes are functionalized and applied for DNA hybridization detection, using methylene blue (MB) as electroactive probe. To this aim, an amine terminated (ss)DNA probe is immobilized on the PC surface of the NEE by reaction via carbodiimide and N-hydroxysulfosuccinimide. In order to increase the number of carboxylic groups present on PC and suitable for the functionalization, the surface of NEEs is oxidized with potassium permanganate. The presence of carboxylic functionalities is verified by spectrochemical titration with thionin acetate (THA) and the effect of the activation treatment on the electrode performances is evaluated by cyclic voltammetry (CV). After activation and functionalization with the probes, the NEE-based sensor is hybridized with complementary target sequences. The effect of the functionalization of the NEEs both with the (ss)DNA probe alone and after hybridization with the target, is studied by measuring the changes in the MB reduction signal by square wave voltammetry (SWV), after incubation in a suitable MB solution, rinsing and transfer to the measurement cell. It was observed that this peak signal decreases significantly after hybridization of the probe with the complementary target. Experimental evidences suggest that the interaction between MB and the guanines of (ss)DNA and (ds)DNA is at the basis of the development of the here observed analytical signal. The proposed approach allows the easy preparation and testing of NEE-based sensors for the electrochemical DNA hybridization detection. PMID:26504963

  18. 76 FR 14432 - Methylene Chloride Standard; Extension of the Office of Management and Budget's (OMB) Approval of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-16

    ... Paperwork Reduction Act of 1995 (44 U.S.C. 3506 et seq.) and Secretary of Labor's Order No. 4-2010 (75 FR... requirements specified by the Methylene Chloride Standard (29 CFR 1910.1052). DATES: Comments must be submitted... entitled ``Methylene Chloride'' (MC) (29 CFR 1910.1052; the ``Standard'') protects workers from the...

  19. Various factors affecting photodecomposition of methylene blue by iron-oxides in an oxalate solution.

    PubMed

    Gulshan, Fahmida; Yanagida, Sayaka; Kameshima, Yoshikazu; Isobe, Toshihiro; Nakajima, Akira; Okada, Kiyoshi

    2010-05-01

    The effect of various factors on the photodecomposition of methylene blue (MB) by iron oxides calcined at various temperatures in various concentrations of oxalate solutions was investigated by illuminating with UV, visible and solar radiation. Iron oxides were prepared by a gel evaporation method and calcined at 200-700 degrees C. XRD showed that the as-synthesized iron oxides were amorphous, but formed maghemite (gamma-Fe(2)O(3)) at 200-400 degrees C and hematite (alpha-Fe(2)O(3)) at > or =500 degrees C. The effect of the various iron oxides, their contents, the oxalate concentration and wavelength of the light source (UV, visible and solar) were all found to strongly influence MB photodecomposition. The optimal contents of the iron oxides increased greatly from 25 to 2000 mg/L at higher calcining temperatures. The MB photodecomposition rate at each optimal iron oxide content was related to the calcining temperature in the order 700 degrees C6, consistent with the presence of iron-oxalate complexes. A much higher concentration of hydroxyl radicals was generated in the present system compared with those from a commercial TiO(2) (ST-01), as determined by the coumarin method. Since this process does not require the addition of hydrogen peroxide and shows good efficiency even under solar light, it is an economically viable method for pre-treating and/or decolorizing wastewaters containing dyes. PMID:20188391

  20. Photodynamic characterization and in vitro application of methylene blue-containing nanoparticle platforms.

    PubMed

    Tang, Wei; Xu, Hao; Kopelman, Raoul; Philbert, Martin A

    2005-01-01

    This article presents the development and characterization of nanoparticles loaded with methylene blue (MB), which are designed to be administered to tumor cells externally and deliver singlet oxygen (1O2) for photodynamic therapy (PDT), i.e. cell kill via oxidative stress to the membrane. We demonstrated the encapsulation of MB, a photosensitizer (PS), in three types of sub-200 nm nanoparticles, composed of polyacrylamide, sol-gel silica and organically modified silicate (ORMOSIL), respectively. Induced by light irradiation, the entrapped MB generated 1O2, and the produced 1O2 was measured quantitatively with anthracene-9,10-dipropionic acid, disodium salt, to compare the effects of different matrices on 1O2 delivery. Among these three different kinds of nanoparticles, the polyacrylamide nanoparticles showed the most efficient delivery of 1O2, but its loading of MB was low. In contrast, the sol-gel nanoparticles had the best MB loading but the least efficient 1O2 delivery. In addition to investigating the matrix effects, a preliminary in vitro PDT study using the MB-loaded polyacrylamide nanoparticles was conducted on rat C6 glioma tumor cells with positive photodynamic results. The encapsulation of MB in nanoparticles should diminish the interaction of this PS with the biological milieu, thus facilitating its systemic administration. Furthermore, the concept of the drug-delivering nanoparticles has been extended to a new type of dynamic nanoplatform (DNP) that only delivers 1O2. This DNP could also be used as a targeted multifunctional platform for combined diagnostics and therapy of cancer. PMID:15595888

  1. Reduction of methylene green by EDTA: a relation between dielectric constant of medium and activated state.

    PubMed

    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. PMID:23261728

  2. Synthesis and characterization of TiO2 pillared montmorillonites: application for methylene blue degradation.

    PubMed

    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. PMID:23957927

  3. Sensitive analytical performance of folding based biosensor using methylene blue tagged aptamers.

    PubMed

    Catanante, Gaëlle; Mishra, Rupesh K; Hayat, Akhtar; Marty, Jean-Louis

    2016-06-01

    This work demonstrates the development of a folding based electrochemical aptasensor using methylene blue (MB) tagged anti-Ochratoxin A (OTA) aptamers. Different aptamer coupling strategies were tested using Hexamethylenediamine, polyethylene glycol, simple adsorption and diazonium coupling mechanism. The best sensitivity was recorded by oxidation of amines using hexamethylenediamine (HDMA) on screen printed carbon electrode (SPCE). To achieve the direct detection of OTA, aptamer conjugated redox probe was used and detection was demonstrated based on the conformational changes in aptamer structure upon OTA sensing. Signaling in this class of sensors arises from changes in electron transfer efficiency upon target-induced changes in the conformation/flexibility of the aptamer probe. These changes can be readily recorded electrochemically. The developed aptasensor is unique in its own mechanism as redox probe tagged aptamer coupling such as MB has never been tried to immobilize using long carbon chain spacers as, addition of spacers would provide more sensitive detection methods. A good dynamic range 0.01-5ng/ml was obtained for OTA with Limit of detection (LOD) 0.01ng/ml and Limit of quantification (LOQ) of 0.03ng/ml respectively. The good reproducibility was recorded with RSD% of 3.75. The obtained straight line equation was y=0.4035x+0.90311, r=0.9976. We believe that the sensor design guidelines outlined here represents a general strategy for developing new folding-based electrochemical aptasensors. The developed aptasensor was extended to screen cocoa samples for OTA contamination. The cocoa samples were extracted and purified using molecular imprinted polymer (MIP) columns. The aptasensor displayed good recovery values in the range 84-85% thus, exhibited the effectiveness of proposed aptasensor for such complex matrices. PMID:27130100

  4. Therapeutic and preventive effects of methylene blue on Alzheimer's disease pathology in a transgenic mouse model.

    PubMed

    Paban, V; Manrique, C; Filali, M; Maunoir-Regimbal, S; Fauvelle, F; Alescio-Lautier, B

    2014-01-01

    Methylene blue (MB) belongs to the phenothiazinium family. It has been used to treat a variety of human conditions and has beneficial effects on the central nervous system in rodents with and without brain alteration. The present study was designed to test whether chronic MB treatment taken after (therapeutic effect) or before (preventive effect) the onset of beta-amyloid pathology influences cognition in a transgenic mouse model (APP/PS1). In addition, the present study aims at revealing whether these behavioral effects might be related to brain alteration in beta-amyloid deposition. To this end, we conducted an in vivo study and compared two routes of drug administration, drinking water versus intraperitoneal injection. Results showed that transgenic mice treated with MB orally or following intraperitoneal injection were protected from cognitive impairments in a variety of social, learning, and exploratory tasks. Immunoreactive beta-amyloid deposition was significantly reduced in the hippocampus and adjacent cortex in MB-treated transgenic mice. Interestingly, these beneficial effects were observed independently of beta-amyloid load at the time of MB treatment. This suggests that MB treatment is beneficial at both therapeutic and preventive levels. Using solid-state High Resolution Magic Angle Spinning Nuclear Magnetic Resonance (HRMAS-NMR), we showed that MB administration after the onset of amyloid pathology significantly restored the concentration of two metabolites related to mitochondrial metabolism, namely alanine and lactate. We conclude that MB might be useful for the therapy and prevention of Alzheimer's disease. This article is part of the Special Issue entitled 'The Synaptic Basis of Neurodegenerative Disorders'. PMID:23891615

  5. Renal effects of Mammea africana Sabine (Guttiferae) stem bark methanol/methylene chloride extract on L-NAME hypertensive rats

    PubMed Central

    Nguelefack-Mbuyo, Elvine Pami; Dimo, Théophile; Nguelefack, Télesphore Benoit; Dongmo, Alain Bertrand; Kamtchouing, Pierre; Kamanyi, Albert

    2010-01-01

    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. PMID:20927244

  6. Potlining Additives

    SciTech Connect

    Rudolf Keller

    2004-08-10

    In this project, a concept to improve the performance of aluminum production cells by introducing potlining additives was examined and tested. Boron oxide was added to cathode blocks, and titanium was dissolved in the metal pool; this resulted in the formation of titanium diboride and caused the molten aluminum to wet the carbonaceous cathode surface. Such wetting reportedly leads to operational improvements and extended cell life. In addition, boron oxide suppresses cyanide formation. This final report presents and discusses the results of this project. Substantial economic benefits for the practical implementation of the technology are projected, especially for modern cells with graphitized blocks. For example, with an energy savings of about 5% and an increase in pot life from 1500 to 2500 days, a cost savings of $ 0.023 per pound of aluminum produced is projected for a 200 kA pot.

  7. Methylene Homologues of Artemisone: An Unexpected Structure-Activity Relationship and a Possible Implication for the Design of C10-Substituted Artemisinins.

    PubMed

    Wu, Yuet; Wu, Ronald Wai Kung; Cheu, Kwan Wing; Williams, Ian D; Krishna, Sanjeev; Slavic, Ksenija; Gravett, Andrew M; Liu, Wai M; Wong, Ho Ning; Haynes, Richard K

    2016-07-01

    We sought to establish if methylene homologues of artemisone are biologically more active and more stable than artemisone. The analogy is drawn with the conversion of natural O- and N-glycosides into more stable C-glycosides that may possess enhanced biological activities and stabilities. Dihydroartemisinin was converted into 10β-cyano-10-deoxyartemisinin that was hydrolyzed to the α-primary amide. Reduction of the β-cyanide and the α-amide provided the respective methylamine epimers that upon treatment with divinyl sulfone gave the β- and α-methylene homologues, respectively, of artemisone. Surprisingly, the compounds were less active in vitro than artemisone against P. falciparum and displayed no appreciable activity against A549, HCT116, and MCF7 tumor cell lines. This loss in activity may be rationalized in terms of one model for the mechanism of action of artemisinins, namely the cofactor model, wherein the presence of a leaving group at C10 assists in driving hydride transfer from reduced flavin cofactors to the peroxide during perturbation of intracellular redox homeostasis by artemisinins. It is noted that the carba analogue of artemether is less active in vitro than the O-glycoside parent toward P. falciparum, although extrapolation of such activity differences to other artemisinins at this stage is not possible. However, literature data coupled with the leaving group rationale suggest that artemisinins bearing an amino group attached directly to C10 are optimal compounds. PMID:27273875

  8. Ene reaction of C{sub 60} and 3-methylene-2,3-dihydrofuran

    SciTech Connect

    Miles, W.H.; Smiley, P.M.

    1996-04-05

    3-Methylene-2,3-dihydrofuran adds to C{sub 60} with good yield. The adduct can be isolated from other products by flash chromatography on silica gel. The structure of the adduct was analyzed using NMR and UV-vis spectroscopies.

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

    PubMed

    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. PMID:9733667

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

    SciTech Connect

    Wojtoniszak, M.; Rogińska, D.; Machaliński, B.; Drozdzik, M.; Mijowska, E.

    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.

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

    EPA Science Inventory

    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...

  12. IRIS Toxicological Review of Dichloromethane (Methylene Chloride) (Interagency Science Consultation Draft)

    EPA Science Inventory

    On March 31, 2010, the draft IRIS Toxicological Review of Dichloromethane (Methylene Chloride) external review draft document and the charge to external peer reviewers were released for public review and comment. The draft document and the charge to external peer reviewers were r...

  13. 21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... 500.27 Section 500.27 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS GENERAL Specific Administrative Rulings and... Commissioner has concluded that animal drugs containing methylene blue for oral use in cats or dogs are...

  14. 21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... 500.27 Section 500.27 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS GENERAL Specific Administrative Rulings and... Commissioner has concluded that animal drugs containing methylene blue for oral use in cats or dogs are...

  15. 21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... 500.27 Section 500.27 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS GENERAL Specific Administrative Rulings and... Commissioner has concluded that animal drugs containing methylene blue for oral use in cats or dogs are...

  16. 21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... 500.27 Section 500.27 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS GENERAL Specific Administrative Rulings and... Commissioner has concluded that animal drugs containing methylene blue for oral use in cats or dogs are...

  17. 40 CFR 721.10581 - Brominated polyurethane prepolymers of methylene diphenyl diisocyanate (MDI) (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Brominated polyurethane prepolymers of... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10581 Brominated polyurethane... polyurethane prepolymers of methylene diphenyl diisocyanate (MDI) (PMNs P-10-524 and P-10-525) are subject...

  18. 40 CFR 721.10581 - Brominated polyurethane prepolymers of methylene diphenyl diisocyanate (MDI) (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Brominated polyurethane prepolymers of... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10581 Brominated polyurethane... polyurethane prepolymers of methylene diphenyl diisocyanate (MDI) (PMNs P-10-524 and P-10-525) are subject...

  19. Liver metastases of breast carcinoma detected on /sup 99m/Tc-methylene diphosphonate bone scan

    SciTech Connect

    Baumert, J.E.; Lantieri, R.L.; Horning, S.; McDougall, I.R.

    1980-02-01

    The accumulation of bone-seeking radiopharmaceuticals has been reported in liver metastases from colon carcinoma and oat cell carcinoma of the lung. Two patients with breast carcinoma in whom hepatic metastases were visualized on /sup 99m/Tc-methylene diphosphonate bone images are described. This has not been previously reported.

  20. SOURCE CHARACTERIZATION AND CONTROL TECHNOLOGY ASSESSMENT OF METHYLENE CHLORIDE EMISSIONS FROM EASTMAN KODAK COMPANY, ROCHESTER, NY

    EPA Science Inventory

    The report gives results of an assessment of potential control technologies for methylene chloride (also known as dichloromethane or DCM) emission sources at Eastman Kodak Company's Kodak Park facility in Rochester, NY. DCM is a solvent used by Kodak in the manufacture of cellulo...

  1. Sugar beet pulp and poly(lactic acid) composites using methylene diphenyl diisocyanate as coupling agent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Composites from sugar beet pulp (SBP) and poly(lactic acid) (PLA) were extruded in the presence of polymeric methylene diphenyl diisocyanate (pMDI). SBP particles were evenly distributed within the PLA matrix phase as revealed by confocal fluorescence microscopic analysis. The resultant composites w...

  2. 21 CFR 520.154b - Bacitracin methylene disalicylate and streptomycin sulfate powder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Bacitracin methylene disalicylate and streptomycin sulfate powder. 520.154b Section 520.154b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.154b Bacitracin...

  3. 21 CFR 520.154b - Bacitracin methylene disalicylate and streptomycin sulfate powder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Bacitracin methylene disalicylate and streptomycin sulfate powder. 520.154b Section 520.154b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.154b Bacitracin...

  4. 21 CFR 520.154b - Bacitracin methylene disalicylate and streptomycin sulfate powder.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Bacitracin methylene disalicylate and streptomycin sulfate powder. 520.154b Section 520.154b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.154b Bacitracin...

  5. A metabonomics study of the hepatotoxicants galactosamine, methylene dianiline and clofibrate in rats.

    PubMed

    Ishihara, Kenji; Katsutani, Naruo; Aoki, Toyohiko

    2006-09-01

    The efficacy of high-resolution (1)H nuclear magnetic resonance ((1)H-NMR) spectroscopy-based metabonomics was studied in a model of rat liver toxicity. Hepatotoxicities were induced in male rats using methylene dianiline, clofibrate and galactosamine. Twenty-four-hr urine from days 1 to 5 after treatment were subjected to (1)H-NMR evaluation of the biochemical effects. Blood were also taken at Days 2, 3 and 5 to examine biochemical changes associated with hepatotoxicities, and histopathological changes were evaluated at termination. Increases in liver enzymes were observed in animals treated with methylene dianiline or galactosamine, and histopathological analysis revealed changes associated with hepatobiliary damage and hepatocellular necrosis in methylene dianiline- and galactosamine-treated animals, respectively. Principal component analysis and statistical Spotfire analyses were used to visualize similarities and differences in urine biochemical profiles produced by (1)H-NMR spectra. The biochemical effects of methylene dianiline and galactosamine were characterized by elevated levels of glucose, fructose, beta-hydroxybutyrate, alanine, acetoacetate, lactate and creatine and decreased levels of hippurate, 2-oxoglutarate, citrate, succinate, trimethylamine-N-oxide, taurine and N-acetylglutamate in rat urine. Clofibrate treatment elevated the levels of N-methylnicotinamide and 3,4-dihydroxymandelate and decreased the levels of 2-oxoglutarate and N-acetylaspartate. This work shows that combinations of (1)H-NMR and pattern recognition are powerful tools in the evaluation of the biochemical effects of xenobiotics in liver. PMID:16930299

  6. Mortality of workers exposed to methylene chloride employed at a plant producing cellulose triacetate film base.

    PubMed Central

    Tomenson, J A; Bonner, S M; Heijne, C G; Farrar, D G; Cummings, T F

    1997-01-01

    OBJECTIVE: To study mortality among 1785 employees of a factory that produced cellulose triacetate film base at Brantham in the United Kingdom. Also, to investigate patterns of mortality after exposure to methylene chloride; in particular, mortality from liver and biliary tract cancer, lung cancer, pancreatic cancer, and cardiovascular disease. SUBJECTS AND METHODS: All male employees with a record of employment at the film factory in 1946-88. A total of 1473 subjects worked in jobs that entailed exposure to methylene chloride. The mean duration of exposure was nine years at 19 ppm (eight hour time weighted average). RESULTS: In the cohort, 334 deaths were identified up to 31 December 1994. Mortalities for the cohort were compared with national and local rates and expressed as standardised mortality ratios (SMR). In the subcohort of workers exposed to methylene chloride, substantially reduced mortalities compared with national and local rates were found for all causes, all cancers, and the principal cancer sites of interest. The significantly reduced lung cancer mortalities in exposed workers (SMR 48) seemed to reflect the restrictions on smoking at the workplace. In contrast, mortality from ischaemic heart disease in exposed workers, although lower than national rates (SMR 92), was slightly increased compared with local rates. However, mortality from ischaemic heart disease was lower in active employees (SMR 83) where a direct effect of exposure to methylene chloride should be concentrated. No in service mortality due to ischaemic heart disease was found in workers with the highest cumulative exposure (> or = 800 ppm-years). CONCLUSIONS: The study provided no indication that employment at the plant, or exposure to methylene chloride, had adversely affected the mortalities of workers. PMID:9282122

  7. Carbamate deposit control additives

    SciTech Connect

    Honnen, L.R.; Lewis, R.A.

    1980-11-25

    Deposit control additives for internal combustion engines are provided which maintain cleanliness of intake systems without contributing to combustion chamber deposits. The additives are poly(oxyalkylene) carbamates comprising a hydrocarbyloxyterminated poly(Oxyalkylene) chain of 2-5 carbon oxyalkylene units bonded through an oxycarbonyl group to a nitrogen atom of ethylenediamine.

  8. Density Functional Theory-Derived Group Additivity and Linear Scaling Methods for Prediction of Oxygenate Stability on Metal Catalysts. Adsorption of Open-Ring Alcohol and Polyol Dehydrogenation Intermediates on Pt-Based Metals

    SciTech Connect

    Salciccioli, Michael; Chen, Ying; Vlachos, Dion G.

    2010-11-09

    Semiempirical methods for prediction of thermochemical properties of adsorbed oxygenates are developed. Periodic density functional theory calculations are used to study the relative stability of ethanol, ethylene glycol, isopropyl alcohol, and glycerol dehydrogenation intermediates on Pt(111). For ethylene glycol dehydrogenation intermediates, it is found that the thermodynamically favored intermediates at each level of dehydrogenation are as follows: HOCH2CHOH, HOCHCHOH, HOCHCOH, HOCCOH ≈ HOCHCO, HOCCO, OCCO. Structural and energetic patterns emerge from these C2HxO2 adsorption calculations that lead to the formation of group additive properties for thermochemical property prediction of oxygenates on Pt(111). Finally, linear scaling relationships of atomic binding energy are used to predict the binding energy of the C2HxO2 species on the Ni(111) surface and Ni-Pt-Pt(111) bimetallic surface. It is shown that the linear scaling relationships can accurately predict the binding energy of larger oxygenates as well as of oxygenates on bimetallic catalysts. Corrections for ring strain and weak oxygen-metal and hydrogen-bonding interactions are added to increase the accuracy of group additivity and linear scaling relationships.

  9. One-pot green synthesis of reduced graphene oxide (RGO)/Fe3O4 nanocomposites and its catalytic activity toward methylene blue dye degradation

    NASA Astrophysics Data System (ADS)

    Vinothkannan, M.; Karthikeyan, C.; Gnana kumar, G.; Kim, Ae Rhan; Yoo, Dong Jin

    2015-02-01

    The reduced graphene oxide (RGO)/Fe3O4 nanocomposites were synthesized through a facile one-pot green synthesis by using solanum trilobatum extract as a reducing agent. Spherical shaped Fe3O4 nanoparticles with the diameter of 18 nm were uniformly anchored over the RGO matrix and the existence of fcc structured Fe3O4 nanoparticles over the RGO matrix was ensured from X-ray diffraction patterns. The amide functional groups exist in the solanum trilobatum extract is directly responsible for the reduction of Fe3+ ions and GO. The thermal stability of GO was increased by the removal of hydrophilic functional groups via solanum trilobatum extract and was further promoted by the ceramic Fe3O4 nanoparticles. The ID/IG ratio of RGO/Fe3O4 was increased over GO, indicating the extended number of structural defects and disorders in the RGO/Fe3O4 composite. The catalytic efficiency of prepared nanostructures toward methylene blue (MB) dye degradation mediated through the electron transfer process of BH4- ions was studied in detail. The π-π stacking, hydrogen bonding and electrostatic interaction exerted between the RGO/Fe3O4 composite and methylene blue, increased the adsorption efficiency of dye molecules and the large surface area and extended number of active sites completely degraded the MB dye within 12 min.

  10. One-pot green synthesis of reduced graphene oxide (RGO)/Fe3O4 nanocomposites and its catalytic activity toward methylene blue dye degradation.

    PubMed

    Vinothkannan, M; Karthikeyan, C; Gnana kumar, G; Kim, Ae Rhan; Yoo, Dong Jin

    2015-02-01

    The reduced graphene oxide (RGO)/Fe3O4 nanocomposites were synthesized through a facile one-pot green synthesis by using solanum trilobatum extract as a reducing agent. Spherical shaped Fe3O4 nanoparticles with the diameter of 18 nm were uniformly anchored over the RGO matrix and the existence of fcc structured Fe3O4 nanoparticles over the RGO matrix was ensured from X-ray diffraction patterns. The amide functional groups exist in the solanum trilobatum extract is directly responsible for the reduction of Fe(3+) ions and GO. The thermal stability of GO was increased by the removal of hydrophilic functional groups via solanum trilobatum extract and was further promoted by the ceramic Fe3O4 nanoparticles. The ID/IG ratio of RGO/Fe3O4 was increased over GO, indicating the extended number of structural defects and disorders in the RGO/Fe3O4 composite. The catalytic efficiency of prepared nanostructures toward methylene blue (MB) dye degradation mediated through the electron transfer process of BH4(-) ions was studied in detail. The π-π stacking, hydrogen bonding and electrostatic interaction exerted between the RGO/Fe3O4 composite and methylene blue, increased the adsorption efficiency of dye molecules and the large surface area and extended number of active sites completely degraded the MB dye within 12 min. PMID:25311523

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Application of anaerobic granular sludge for competitive biosorption of methylene blue and Pb(II): Fluorescence and response surface methodology.

    PubMed

    Shi, Li; Wei, Dong; Ngo, Huu Hao; Guo, Wenshan; Du, Bin; Wei, Qin

    2015-10-01

    This study assessed the biosorption of anaerobic granular sludge (AGS) and its capacity as a biosorbent to remove Pb(II) and methylene blue (MB) from multi-components aqueous solution. It emerged that the biosorption data fitted well to the pseudo-second-order and Langmuir adsorption isotherm models in both single and binary systems. In competitive biosorption systems, Pb(II) and MB will suppress each other's biosorption capacity. Spectroscopic analysis, including Fourier transform infrared spectroscopy (FTIR) and fluorescence spectroscopy were integrated to explain this interaction. Hydroxyl and amine groups in AGS were the key functional groups for sorption. Three-dimensional excitation-emission matrix (3D-EEM) implied that two main protein-like substances were identified and quenched when Pb(II) or MB were present. Response surface methodology (RSM) confirmed that the removal efficiency of Pb(II) and MB reached its peak when the concentration ratios of Pb(II) and MB achieved a constant value of 1. PMID:26210143

  13. Adsorption studies of methylene blue and phenol onto vetiver roots activated carbon prepared by chemical activation.

    PubMed

    Altenor, Sandro; Carene, Betty; Emmanuel, Evens; Lambert, Jacques; Ehrhardt, Jean-Jacques; Gaspard, Sarra

    2009-06-15

    Vetiver roots have been utilized for the preparation of activated carbon (AC) by chemical activation with different impregnation ratios of phosphoric acid, X(P) (gH(3)PO(4)/g precursor): 0.5:1; 1:1 and 1.5:1. Textural characterization, determined by nitrogen adsorption at 77K shows that mixed microporous and mesoporous structures activated carbons (ACs) with high surface area (>1000 m(2)/g) and high pore volume (up to 1.19 cm(3)/g) can be obtained. The surface chemical properties of these ACs were investigated by X-ray photoelectron spectroscopy (XPS) and Boehm titration. Their textural and chemical characteristics were compared to those of an AC sample obtained by steam activation of vetiver roots. Classical molecules used for characterizing liquid phase adsorption, phenol and methylene blue (MB), were used. Adsorption kinetics of MB and phenol have been studied using commonly used kinetic models, i.e., the pseudo-first-order model, the pseudo-second-order model, the intraparticle diffusion model and as well the fractal, BWS (Brouers, Weron and Sotolongo) kinetic equation. The correlation coefficients (R(2)) and the normalized standard deviation Deltaq (%) were determined showing globally, that the recently derived fractal kinetic equation could best describe the adsorption kinetics for the adsorbates tested here, indicating a complex adsorption mechanism. The experimental adsorption isotherms of these molecules on the activated carbon were as well analysed using four isotherms: the classical Freundlich, Langmuir, Redlich-Peterson equations, but as well the newly published deformed Weibull Brouers-Sotolongo isotherm. The results obtained from the application of the equations show that the best fits were achieved with the Brouers-Sotolongo equation and with the Redlich-Peterson equation. Influence of surface functional groups towards MB adsorption is as well studied using various ACs prepared from vetiver roots and sugar cane bagasse. Opposite effects governing MB

  14. Jaw uptake of technetium-99 methylene diphosphonate in patients on biphosphonates: a word of caution.

    PubMed

    Zanglis, Antonios; Andreopoulos, Dimitrios; Dima, Marina; Baltas, Georgios; Baziotis, Nikolaos

    2007-01-01

    Nitrogen-containing biphosphonates are a group of medications that are increasingly used in the management of Paget's disease, fibrous dysplasia, osteoporosis, multiple myeloma and metastatic prostate or breast cancer bone disease. On 2004 it was established that nitrogen-containing biphosphonates may induce jaw osteonecrosis and since then, a substantial number of publications has supported this finding. Jaw osteonecrosis may be asymptomatic, lasting for about a year or symptomatic, accompanied with mild or severe pain. Jaw osteonecrosis usually results in patients with poor dental hygiene, or subjected to invasive dental procedures. Its incidence increases with the length of nitrogen-containing biphosphonates treatment and appears to be higher for the Zometa(TM) users. It is important to early recognize this entity, since early intervention can make a significant difference to the outcome of this debilitating side effect. We here report three patients who had a positive technetium-99m methylene diphosphonate ((99m)Tc-MDP) bone scan. One of these patients also had osteomyelitis and was treated aggressively. The other two were treated in a more conservative manner. Detailed dental examination supported the scintigraphic findings. Biopsy was performed only in one patient and also offered specimens for antibiotic cultures. In discussion, jaw biopsy is a debatable procedure in the setting of jaw osteonecrosis and many consider that it should be avoided in most cases, except if it is necessary to establish the diagnosis and suggest antibiotic treatment by obtaining samples for bacterial cultures. Although axial tomography and magnetic resonance imaging are useful in defining the extent of the disease, 3-phase (99m)Tc-MDP bone scan is the most sensitive imaging modality pinpointing the disease at its early stages. In conclusion, a 3-phase (99m)Tc-MDP scan with anterior and lateral views of the skull is indicated in all symptomatic or asymptomatic patients, with a

  15. Study of epigenetic properties of Poly(HexaMethylene Biguanide) hydrochloride (PHMB).

    PubMed

    Creppy, Edmond E; Diallo, Aboudoulatif; Moukha, Serge; Eklu-Gadegbeku, Christophe; Cros, Daniel

    2014-08-01

    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

  16. Hyperbaric oxygen therapy augments the photodynamic action of methylene blue against bacteria in vitro

    NASA Astrophysics Data System (ADS)

    Bisland, S. K.; Dadani, F. N.; Chien, C.; Wilson, B. C.

    2007-02-01

    Photodynamic therapy (PDT) entails the combination of photosensitizer and light to generate cytotoxic molecules that derive from molecular oxygen (O II). The presence of sufficient O II within the target tissues is critical to the efficiency of PDT. This study investigates the use of hyperbaric oxygen therapy in combination with PDT (HOTPDT) to augment the photodynamic action of methylene blue (MB) or 5-aminolevulinic acid (ALA) against gram positive and gram negative bacterial strains in vitro. Staphylococcus aureus or Pseudomonas aeruginosa were grown in trypticase soy broth as planktonic cultures (~10 8/mL) or as established biofilms in 48 well plates (3 days old) at 32°C. Dark toxicity and PDT response in the presence or absence of HOT (2 atmospheres, 100% O II for 30, 60 or 120 min) was established for both MB (0-0.1 mM) and ALA (0- 1 mM) for a range of incubation times. The number of surviving colonies (CFU/mL) was plotted for each treatment groups. Light treatments (5, 10, 20 or 30 J/cm2) were conducted using an array of halogen bulbs with a red filter providing 90% transmittance over 600-800 nm at 21 mW/cm2. HOT increased the dark toxicity of MB (30 min, 0.1 mM) from < 0.2 log cell kill to 0.5 log cell kill. Dark toxicity of ALA (4 hr, 1 mM) was negligible and did not increase with HOT. For non-dark toxic concentrations of MB or ALA, (0.05 mM and 1 mM respectively) HOT-PDT enhanced the antimicrobial effect of MB against Staphylococcus aureus in culture by >1 and >2 logs of cell kill (CFU/mL) at 5 and 10 J/cm2 light dose respectively as compared to PDT alone. HOT-PDT also increased the anti-microbial effects of MB against Staphylococcus aureus biofilms compared to PDT, albeit less so (> 2 logs) following 10 J/cm2 light dose. Anti-microbial effects of PDT using ALA were not significant for either strain with or without HOT. These data suggest that HOTPDT may be useful for improving the PDT treatment of bacterial infections.

  17. Synthesis of a stationary phase based on silica modified with branched octadecyl groups by Michael addition and photoinduced thiol-yne click chemistry for the separation of basic compounds.

    PubMed

    Huang, Guang; Ou, Junjie; Wang, Hongwei; Ji, Yongsheng; Wan, Hao; Zhang, Zhang; Peng, Xiaojun; Zou, Hanfa

    2016-04-01

    A novel silica-based stationary phase with branched octadecyl groups was prepared by the sequential employment of the Michael addition reaction and photoinduced thiol-yne click chemistry with 3-aminopropyl-functionalized silica microspheres as the initial material. The resulting stationary phase denoted as SiO2 -N(C18)4 was characterized by elemental analysis, FTIR spectroscopy and Raman spectroscopy, demonstrating the existence of branched octadecyl groups in silica microspheres. The separations of benzene homologous compounds, acid compounds and amine analogues were conducted, demonstrating mixed-mode separation mechanism on SiO2 -N(C18)4 . Baseline separation of basic drugs mixture was acquired with the mobile phase of acetonitrile/H2 O (5%, v/v). SiO2 -N(C18)4 was further applied to separate Corydalis yanhusuo Wang water extracts, and more baseline separation peaks were obtained for SiO2 -N(C18)4 than those on Atlantis dC18 column. It can be expected that this new silica-based stationary phase will exhibit great potential in the analysis of basic compounds. PMID:26910263

  18. Computer-assisted assignment of functional domains in the nonstructural polyprotein of hepatitis E virus: delineation of an additional group of positive-strand RNA plant and animal viruses.

    PubMed

    Koonin, E V; Gorbalenya, A E; Purdy, M A; Rozanov, M N; Reyes, G R; Bradley, D W

    1992-09-01

    Computer-assisted comparison of the nonstructural polyprotein of hepatitis E virus (HEV) with proteins of other positive-strand RNA viruses allowed the identification of the following putative functional domains: (i) RNA-dependent RNA polymerase, (ii) RNA helicase, (iii) methyltransferase, (iv) a domain of unknown function ("X" domain) flanking the papain-like protease domains in the polyproteins of animal positive-strand RNA viruses, and (v) papain-like cysteine protease domain distantly related to the putative papain-like protease of rubella virus (RubV). Comparative analysis of the polymerase and helicase sequences of positive-strand RNA viruses belonging to the so-called "alpha-like" supergroup revealed grouping between HEV, RubV, and beet necrotic yellow vein virus (BNYVV), a plant furovirus. Two additional domains have been identified: one showed significant conservation between HEV, RubV, and BNYVV, and the other showed conservation specifically between HEV and RubV. The large nonstructural proteins of HEV, RubV, and BNYVV retained similar domain organization, with the exceptions of relocation of the putative protease domain in HEV as compared to RubV and the absence of the protease and X domains in BNYVV. These observations show that HEV, RubV, and BNYVV encompass partially conserved arrays of distinctive putative functional domains, suggesting that these viruses constitute a distinct monophyletic group within the alpha-like supergroup of positive-strand RNA viruses. PMID:1518855

  19. Mechanism of cell destruction and cell protection during methylene-blue-induced PDT

    NASA Astrophysics Data System (ADS)

    Rueck, Angelika C.; Beck, G.; Heckelsmiller, K.; Knoedlsdorfer, U.; Genze, Felicitas; Orth, K.

    1999-02-01

    Methylene Blue (MB+) is a well-known dye in medicine and has been discussed as an easily applicable drug for the topical treatment in photodynamic therapy (PDT). MB+ can potentially be used as a redox indicator to detect the important redox reactions that are induced during PDT. MB+ induced PDT was successful in the intraluminal treatment of inoperable esophageal tumors and in the topical treatment of psoriasis. In order to improve the therapy, the reaction mechanism of MB+ was investigated in vivo by local injection of MB+ in a xenotransplanted subcutaneous tumor (adeno-carcinoma, G-3) in female nude mice. The MB+ preparation 'MB+1%' was applied both undiluted and diluted to 0.1% and 0.01% with isotonic sodium chloride. After an incubation period of 1 h, the tumors were irradiated at 662 nm. Treatment with 1% MB+ and subsequent irradiation with 100 J/cm2 led to complete tumor destruction in 79% of the treated animals. A decrease of the fluence rate from 100 mW/cm2 to 50 mW/cm2 significantly increased the phototoxic response, which was attributed to oxygen depletion but also to nonlinear redox reactions. In addition, fractionated light application with 15 s interruption intervals enhanced the effect. When 0.1% MB+ was used, complete tumor destruction was observed only in 10% of the treated animals. Below a relatively high threshold dose the therapeutic response was not significant. The efficiency of the therapy was correlated with nonlinear dynamics of MB+ on a subcellular level, using laser scanning microscopy. During MB+-PDT nonlinear redox- reactions were induced. This could be deduced from local fast changes of the MB+-fluorescence as well as the pH-value during irradiation of single cells. The light induced reaction of MB+ seems to be correlated with the nonlinear production of reactive oxygen species (ROS). As a consequence below a threshold dose the reducing ability of MB+ prevents tissue from oxidative damage. However, above this dose, as a point of no

  20. Skin Flap Necrosis by Bone Marking with Methylene Blue in Cochlear Implantation.

    PubMed

    Kim, Yeon Hoo; Cho, Sung Il

    2015-09-01

    One of surgical complications in cochlear implantation is the necrosis of the skin flap above the receiver-stimulator coil. We present a case of 55-year-old woman who underwent cochlear implantation and developed a bluish skin necrosis due to bone marking. The planned position for the receiver-stimulator was marked using methylene blue through skin to bone. She did not undergo skin flap thinning and underwent successful implantation with complete electrode insertion. Few weeks postoperatively, the patient developed bluish discoloration with progressive thick, blue eschar formation and skin flap necrosis. She subsequently underwent wound debridement and skin flap closure. Cochlear explantation was not necessary. Timely diagnosis and management about this complication is necessary to prevent further skin breakdown and subsequent device extrusion. This report identifies the marking using methylene blue as another possible source of skin flap necrosis in cochlear implantation, and surgeons should be aware of this potential complication. PMID:26413579

  1. Photo-Induced Inactivation of Viruses: Adsorption of Methylene Blue, Thionine, and Thiopyronine on Qβ Bacteriophage

    NASA Astrophysics Data System (ADS)

    Jockusch, Steffen; Lee, Denis; Turro, Nicholas J.; Leonard, Edward F.

    1996-07-01

    The adsorption of cationic organic dyes (methylene blue, thionine, and thiopyronine) on Qβ bacteriophage was studied by UV-visible and fluorescence spectroscopy. The dyes have shown a strong affinity to the virus and some have been used as sensitizers for photo-induced inactivation of virus. In the methylene blue concentration range of 0.1-5 μ M and at high ratios of dye to virus (greater than 1000 dye molecules per virion), the dyes bind as aggregates on the virus. Aggregation lowers the efficiency of photoinactivation because of self-quenching of the dye. At lower ratios of dye to virus (lower than 500 dye molecules per virion), the dye binds to the virus as a monomer. Fluorescence polarization and time-resolved studies of the fluorescence support the conclusions based on fluorescence quenching. Increasing the ionic strength (adding NaCl) dissociates bound dye aggregates on the virus and releases monomeric dye into the bulk solution.

  2. ACINETOBACTER SPP.: DISTINCT MORPHOLOGY ON EOSIN METHYLENE BLUE AGAR AS AN AID TO IDENTIFICATION IN DRINKING WATER

    EPA Science Inventory

    'Acinetobacter calcoaceticus', frequently found in drinking waters and implicated in nosocomial infections, was presumptively identified by its tiny, blue colonial appearance on Levine eosin methylene blue agar. All of the 33 isolates from drinking water showing this distinctive ...

  3. 40 CFR 721.10626 - 1,4-Butanediol, polymer with substituted alkane and substituted methylene biscarbomonocycle, 2...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... activities. Requirements as specified in § 721.80(o) and (y)(1). (ii) (b) Specific requirements. The... substituted alkane and substituted methylene biscarbomonocycle, 2-hydroxyalkyl acrylate-blocked (PMN...

  4. POLLUTION PREVENTION DEMONSTRATION AND EVALUATION OF PAINT APPLICATION EQUIPMENT AND ALTERNATIVES TO METHYLENE CHLORIDE AND METHYL ETHYL KETONE

    EPA Science Inventory

    The report gives results of demonstrations of technologies to prevent or control emissions of hazardous air pollutant (HAPs) and volatile organic compounds (VOCs) from processes with high solvent usage: (1) paint stripping using methylene chloride, (2) cleaning paint equipment wi...

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

    EPA Science Inventory

    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...

  6. Enantioselective synthesis of fluorinated branched allylic compounds via Ir-catalyzed allylations of functionalized fluorinated methylene derivatives.

    PubMed

    Zhang, Hongbo; Chen, Jiteng; Zhao, Xiao-Ming

    2016-08-14

    Enantioselective introduction of the functionalized monofluorinated methylenes into the allylic fragment under Ir catalysis has been realized, which gave the fluorinated branched allyl products in good to high yields with excellent regio- and enantioselectivities. PMID:27383920

  7. Methylene blue facilitates the extinction of fear in an animal model of susceptibility to learned helplessness.

    PubMed

    Wrubel, Kathryn M; Barrett, Douglas; Shumake, Jason; Johnson, S Elizabeth; Gonzalez-Lima, F

    2007-02-01

    The objectives were to (1) extend previous findings on fear extinction deficits in male congenitally helpless rats (a model for susceptibility to learned helplessness) to female congenitally helpless rats, and (2) attempt a therapeutic intervention with methylene blue, a metabolic enhancer that improves memory retention, to alleviate the predicted extinction deficits. In the first experiment, fear acquisition (four tone-shock pairings in operant chamber) was followed by extinction training (60 tones in open field). Congenitally helpless rats showed fear acquisition similar to controls but had dramatic extinction deficits, and did not display the gradual extinction curves observed in controls. Congenitally helpless rats demonstrated greater tone-evoked freezing as compared to controls in both the acquisition and extinction contexts one week after extinction training, and also in the extinction probe conducted one month later. In the second experiment (which began one month after the first experiment) congenitally helpless subjects were further exposed to tones for 5 days, each followed by 4 mg/kg methylene blue or saline IP, and had a fear renewal test in the acquisition context. Methylene blue administration improved retention of the extinction memory as demonstrated by significant decreases in fear renewal as compared to saline-administered congenitally helpless subjects. The impaired ability to extinguish fear to a traumatic memory in congenitally helpless rats supports the validity of this strain as an animal model for vulnerability to post-traumatic stress disorder, and this study further suggests that methylene blue may facilitate fear extinction as an adjunct to exposure therapy. PMID:17011803

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

    PubMed

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

    2016-04-01

    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. PMID:26273895

  9. Extraosseous accumulation of bone scan tracer (99m)Tc-methylene diphosphonate in a phlebolith.

    PubMed

    Kulkarni, Mukta; Agrawal, Archi; Zade, Anand; Purandare, Nilendu; Shah, Sneha; Rangarajan, Venkatesh

    2012-01-01

    Uptake in non-osseous, non-urologic tissues is occasionally found in the performance of bone scintigraphy. These uptakes reflect an atypical interaction between the radiopharmaceutical and the patient. Knowledge of the rare extraskeletal uptakes and their clinical relevance helps in better interpretation of bone scans. We report an unusual occurrence of extraosseous accumulation of (99m)Tc-methylene diphosphonate in a phlebolith in bone scan, confirmed with the aid of photon emission computed tomography and computed tomography. PMID:23599599

  10. Extraosseous accumulation of bone scan tracer 99mTc-methylene diphosphonate in a phlebolith

    PubMed Central

    Kulkarni, Mukta; Agrawal, Archi; Zade, Anand; Purandare, Nilendu; Shah, Sneha; Rangarajan, Venkatesh

    2012-01-01

    Uptake in non-osseous, non-urologic tissues is occasionally found in the performance of bone scintigraphy. These uptakes reflect an atypical interaction between the radiopharmaceutical and the patient. Knowledge of the rare extraskeletal uptakes and their clinical relevance helps in better interpretation of bone scans. We report an unusual occurrence of extraosseous accumulation of 99mTc-methylene diphosphonate in a phlebolith in bone scan, confirmed with the aid of photon emission computed tomography and computed tomography. PMID:23599599

  11. Source reduction for prevention of methylene chloride hazards: cases from four industrial sectors

    PubMed Central

    Roelofs, Cora R; Ellenbecker, Michael J

    2003-01-01

    Background Source reduction, defined as chemical, equipment and process changes that intervene in an industrial process to eliminate or reduce hazards, has not figured as a front-line strategy for the protection of workers' health. Such initiatives are popular for environmental protection, but their feasibility and effectiveness as an industrial hygiene approach have not been well described. Methods We investigated four cases of source reduction as a hazard prevention strategy in Massachusetts companies that had used methylene chloride, an occupational carcinogen, for cleaning and adhesive thinning. Three cases were retrospective and one was prospective, where the researchers assisted with the source reduction process change. Data were collected using qualitative research methods, including in-depth interviews and site visits. Results Motivated by environmental restrictions, a new worker health standard, and opportunity for productivity improvements, three companies eliminated their use of methylene chloride by utilizing available technologies and drop-in substitutes. Aided by technical assistance from the investigators, a fourth case dramatically reduced its use of methylene chloride via process and chemistry changes. While the companies' evaluations of potential work environment impacts of substitutes were not extensive, and in two cases new potential hazards were introduced, the overall impact of the source reduction strategy was deemed beneficial, both from a worker health and a production standpoint. Conclusion The findings from these four cases suggest that source reduction should be considered potentially feasible and effective for reducing or eliminating the potential hazards of methylene chloride exposure. Especially when faced with a hazard that is both an environmental and worker health concern, companies may chose to change their processes rather than rely on local exhaust ventilation equipment or personal protective equipment that might not be as

  12. Adjuvant therapy with methylene blue in the treatment of right ventricular failure after pulmonary embolectomy.

    PubMed

    Raikhelkar, Jayashree K; Milla, Federico; Darrow, Bruce; Scurlock, Corey

    2011-04-01

    Severe pulmonary embolism often leads to right ventricular failure after surgical embolectomy secondary to ischaemia reperfusion injury and acute lung injury (ALI). Acute right ventricular dysfunction is traditionally treated with inotropes and vasopressors to maintain cardiac output and coronary perfusion as well as selective pulmonary vasodilators to provide right ventricular afterload reduction. We report the first case of utilisation of methylene (MB) in a patient with acute right ventricular failure and vasoplegic shock after surgical pulmonary embolectomy. PMID:20952252

  13. Methylene bisphosphonates as the inhibitors of HIV RT phosphorolytic activity.

    PubMed

    Yanvarev, D V; Korovina, A N; Usanov, N N; Khomich, O A; Vepsäläinen, J; Puljula, E; Kukhanova, M K; Kochetkov, S N

    2016-08-01

    The structure-function analysis of 36 methylenebisphosphonates (BPs) as inhibitors of the phosphorolytic activity of native and drug-resistant forms of HIV-1 reverse transcriptase (RT) was performed. It was shown that with the increase of the inhibitory potential of BPs towards the phosphorolytic activity raises their ability to inhibit the RT-catalyzed DNA elongation. Herein, we report the impact of the thymidine analog mutations (TAM) on the activity of bisphosphonates, as well as some structural features of the BPs, allowing them to maintain the inhibitory activity on the enzyme resistant to nucleoside analog therapy. We estimated the Mg(2+)-coordinating group structure, the linker and the aromatic pharmacophore influence on the inhibitory potential of the BPs. Based on the 31 BPs SAR, several BPs with improved inhibitory properties were designed and synthesized. PMID:27230835

  14. Methylene blue protects against TDP-43 and FUS neuronal toxicity in C. elegans and D. rerio.

    PubMed

    Vaccaro, Alexandra; Patten, Shunmoogum A; Ciura, Sorana; Maios, Claudia; Therrien, Martine; Drapeau, Pierre; Kabashi, Edor; Parker, J Alex

    2012-01-01

    The DNA/RNA-binding proteins TDP-43 and FUS are found in protein aggregates in a growing number of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and related dementia, but little is known about the neurotoxic mechanisms. We have generated Caenorhabditis elegans and zebrafish animal models expressing mutant human TDP-43 (A315T or G348C) or FUS (S57Δ or R521H) that reflect certain aspects of ALS including motor neuron degeneration, axonal deficits, and progressive paralysis. To explore the potential of our humanized transgenic C. elegans and zebrafish in identifying chemical suppressors of mutant TDP-43 and FUS neuronal toxicity, we tested three compounds with potential neuroprotective properties: lithium chloride, methylene blue and riluzole. We identified methylene blue as a potent suppressor of TDP-43 and FUS toxicity in both our models. Our results indicate that methylene blue can rescue toxic phenotypes associated with mutant TDP-43 and FUS including neuronal dysfunction and oxidative stress. PMID:22848727

  15. Methylene Blue Protects against TDP-43 and FUS Neuronal Toxicity in C. elegans and D. rerio

    PubMed Central

    Vaccaro, Alexandra; Patten, Shunmoogum A.; Ciura, Sorana; Maios, Claudia; Therrien, Martine; Drapeau, Pierre; Kabashi, Edor; Parker, J. Alex

    2012-01-01

    The DNA/RNA-binding proteins TDP-43 and FUS are found in protein aggregates in a growing number of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and related dementia, but little is known about the neurotoxic mechanisms. We have generated Caenorhabditis elegans and zebrafish animal models expressing mutant human TDP-43 (A315T or G348C) or FUS (S57Δ or R521H) that reflect certain aspects of ALS including motor neuron degeneration, axonal deficits, and progressive paralysis. To explore the potential of our humanized transgenic C. elegans and zebrafish in identifying chemical suppressors of mutant TDP-43 and FUS neuronal toxicity, we tested three compounds with potential neuroprotective properties: lithium chloride, methylene blue and riluzole. We identified methylene blue as a potent suppressor of TDP-43 and FUS toxicity in both our models. Our results indicate that methylene blue can rescue toxic phenotypes associated with mutant TDP-43 and FUS including neuronal dysfunction and oxidative stress. PMID:22848727

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

    NASA Astrophysics Data System (ADS)

    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. Electrochemical preparation of poly(methylene blue)/graphene nanocomposite thin films

    SciTech Connect

    Erçarıkcı, Elif; Dağcı, Kader; Topçu, Ezgi; Alanyalıoğlu, Murat

    2014-07-01

    Highlights: • Poly(MB)/graphene thin films are prepared by a simple electrochemical approach. • Graphene layers in the film show a broad band in visible region of absorbance spectra. • Morphology of composite films indicates both disordered and ordered regions. • XRD reveals that nanocomposite films include rGO layers after electropolymerization process. • Chemically prepared graphene is better than electrochemically prepared graphene for electrooxidation of nitrite. - Abstract: Poly(methylene blue)/graphene nanocomposite thin films were prepared by electropolymerization of methylene blue in the presence of graphene which have been synthesized by two different methods of a chemical oxidation process and an electrochemical approach. Synthesized nanocomposite thin films were characterized by using cyclic voltammetry, UV–vis. absorption spectroscopy, powder X-ray diffraction, and scanning tunneling microscopy techniques. Electrocatalytical properties of prepared poly(methylene blue)/graphene nanocomposite films were compared toward electrochemical oxidation of nitrite. Under optimized conditions, electrocatalytical effect of nanocomposite films of chemically prepared graphene through electrochemical oxidation of nitrite was better than that of electrochemically prepared graphene.

  18. Functional Elastic Hydrogel as Recyclable Membrane for the Adsorption and Degradation of Methylene Blue

    PubMed Central

    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 Pb2+ than Cu2+. 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. PMID:24586396

  19. Determination of low level sulfides in environmental waters by automated gas dialysis/methylene blue colorimetry

    SciTech Connect

    Francom, D. Goodwin, L.R.; Dieken, F.P. )

    1990-01-01

    A sensitive and rapid automated method has been developed for the selective analysis of acid extractable sulfide in environmental samples by combining gas dialysis separation techniques with methylene blue detection procedures. Acid extractable sulfide is separated from the sample matrix by the gas dialysis membrane and subsequently trapped in a dilute sodium hydroxide receiving stream. This stream is reacted with N,N-dimethyl-p-phenylenediamine and ferric chloride to produce methylene blue which is then quantitated colorimetrically at 660 nm. For standards and nonturbid environmental samples, there is good agreement between the results obtained by this procedure and the standard methylene blue method. The effect of interferences on the accurate determination of sulfide by both methods was also examined and it was found that cupric ions significantly interfered with sulfide estimation. To obtain adequate sulfide recoveries in tap water and environmental samples ascorbic acid must be added as an antioxidant. A detection limit of 2 {mu}g/L of sulfide has been obtained using this procedure.

  20. Methylene Blue: The Long and Winding Road from Stain to Brain: Part 1.

    PubMed

    Howland, Robert H

    2016-09-01

    Methylene blue, first discovered and used as a dye in the textile industry, has long been used for biological staining in histology, bacteriology, and hematology. Because of its unique physiochemical properties, it was the first synthetic drug used in medicine, having been used to treat malaria more than one century ago. Methylene blue was also one of the first drugs used for the treatment of patients with psychosis at the end of the 19th century and was the lead drug in the serendipitous development of phenothiazine antipsychotic drugs in the mid-20th century. It was studied in bipolar disorder in the 1980s and has been investigated in neurodegenerative disorders in recent years. The history of methylene blue from its discovery as a dye to its use as a stain and then its therapeutic application in medicine is an example of how a drug's use can evolve over time through careful observation, clinical needs, serendipity, and the integration of concepts from different disciplines. [Journal of Psychosocial Nursing and Mental Health Services, 54(9), 21-24.]. PMID:27576224

  1. 2H-NMR resolution of the methylenic isotopomers of ethanol applied to the study of stereospecific enzyme-catalysed exchange.

    PubMed

    Rabiller, C; Mesbahi, M; Martin, M L

    1990-01-01

    We have shown that site-specific natural isotope fractionation of hydrogen studied by NMR (SNIF-NMR) is an important source of information on the mechanistic and environmental effects which govern the photosynthesis of sugars and their fermentation into ethanol. Three isotope ratios associated with the methyl, methylene, and hydroxyl sites of ethanol are determined in achiral media. In this study we show that complementary information about possible stereospecific mechanisms involving the methylenic hydrogens is also rendered accessible by 2H-NMR enantiomeric resolution. The synthesis of mandelate esters enables exchange between the pro-R site of ethanol and water to be investigated. Simultaneous access to the three site-specific isotope ratios of the ethyl group is obtained at isotopic dilutions close to the natural ones. Mediation of the exchange by the enzymic system alcohol dehydrogenase-alpha-lipoyldehydrogenase and by the yeast Saccharomyces cerevisiae are compared. The progress of the reaction can be followed quantitatively as a function of time and the occurrence of glycolytic metabolism of endogeneous materials by yeast can be substantiated in a one-pot experiment. PMID:2205266

  2. A Case of Severe Chlorite Poisoning Successfully Treated With Early Administration of Methylene Blue, Renal Replacement Therapy, and Red Blood Cell Transfusion

    PubMed Central

    Gebhardtova, Andrea; Vavrinec, Peter; Vavrincova-Yaghi, Diana; Seelen, Mark; Dobisova, Anna; Flassikova, Zora; Cikova, Andrea; Henning, Robert H.; Yaghi, Aktham

    2014-01-01

    Abstract The case of a 55-year-old man who attempted suicide by ingesting <100 mL of 28% sodium chlorite solution is presented. On arrival in the intensive care unit, the patient appeared cyanotic with lowered consciousness and displayed anuria and chocolate brown serum. Initial laboratory tests revealed 40% of methemoglobin. The formation of methemoglobin was effectively treated with methylene blue (10% after 29 hours). To remove the toxin, and because of the anuric acute renal failure, the patient received renal replacement therapy. Despite these therapeutic measures, the patient developed hemolytic anemia and disseminated intravascular coagulation, which were treated with red blood cell transfusion and intermittent hemodialysis. These interventions led to the improvement of his condition and the patient eventually fully recovered. Patient gave written informed consent. This is the third known case of chlorite poisoning that has been reported. Based upon this case, we suggest the management of sodium chlorite poisoning to comprise the early administration of methylene blue, in addition to renal replacement therapy and transfusion of red blood cells. PMID:25144325

  3. Fabrication of magnetic carbon composites from peanut shells and its application as a heterogeneous Fenton catalyst in removal of methylene blue

    NASA Astrophysics Data System (ADS)

    Zhou, Lincheng; Ma, Junjun; Zhang, He; Shao, Yanming; Li, Yanfeng

    2015-01-01

    Magnetic carbons were prepared from agricultural waste peanut shells and Ferric ammonium oxalate via a simple impregnation and carbonization process. The obtained composites were characterized by element analysis, MÖssbauer spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, X-ray diffraction, vibrating sample magnetometry and the Brunauer-Emmett-Teller surface area method, respectively. The magnetic carbon material was used as catalyst of heterogeneous Fenton reaction to remove methylene blue with the help of persulfate in waste water. The results indicated that both the removal rate and removal efficiency of this catalytic system are very excellent. The degradation efficiency was best (90% within 30 min) using initial concentrations of 0.5 g L-1 persulfate and 40 mg L-1 methylene blue. The removal mechanism was investigated by LC-MS. The catalyst retained its activity after seven reuses, indicating its good stability and reusability. It is inexpensive because it consists mainly of agricultural waste. Its porosity contributed to its high activity, which was achieved without any additional activation process. These indicating that the catalyst is potentially useful in the treatment of wastewater.

  4. Methylene Blue-Loaded Dissolving Microneedles: Potential Use in Photodynamic Antimicrobial Chemotherapy of Infected Wounds

    PubMed Central

    Caffarel-Salvador, Ester; Kearney, Mary-Carmel; Mairs, Rachel; Gallo, Luigi; Stewart, Sarah A.; Brady, Aaron J.; Donnelly, Ryan F.

    2015-01-01

    Photodynamic therapy involves delivery of a photosensitising drug that is activated by light of a specific wavelength, resulting in generation of highly reactive radicals. This activated species can cause destruction of targeted cells. Application of this process for treatment of microbial infections has been termed “photodynamic antimicrobial chemotherapy” (PACT). In the treatment of chronic wounds, the delivery of photosensitising agents is often impeded by the presence of a thick hyperkeratotic/necrotic tissue layer, reducing their therapeutic efficacy. Microneedles (MNs) are an emerging drug delivery technology that have been demonstrated to successfully penetrate the outer layers of the skin, whilst minimising damage to skin barrier function. Delivering photosensitising drugs using this platform has been demonstrated to have several advantages over conventional photodynamic therapy, such as, painless application, reduced erythema, enhanced cosmetic results and improved intradermal delivery. The aim of this study was to physically characterise dissolving MNs loaded with the photosensitising agent, methylene blue and assess their photodynamic antimicrobial activity. Dissolving MNs were fabricated from aqueous blends of Gantrez® AN-139 co-polymer containing varying loadings of methylene blue. A height reduction of 29.8% was observed for MNs prepared from blends containing 0.5% w/w methylene blue following application of a total force of 70.56 N/array. A previously validated insertion test was used to assess the effect of drug loading on MN insertion into a wound model. Staphylococcus aureus, Escherichia coli and Candida albicans biofilms were incubated with various methylene blue concentrations within the range delivered by MNs in vitro (0.1–2.5 mg/mL) and either irradiated at 635 nm using a Paterson Lamp or subjected to a dark period. Microbial susceptibility to PACT was determined by assessing the total viable count. Kill rates of >96%, were achieved for

  5. Photodynamic therapy for American cutaneous leishmaniasis: the efficacy of methylene blue in hamsters experimentally infected with Leishmania (Leishmania) amazonensis.

    PubMed

    Peloi, Lílian Somenci; Biondo, Carlos Eduardo Guerino; Kimura, Elza; Politi, Mario José; Lonardoni, Maria Valdrinez Campana; Aristides, Sandra Mara Alessi; Dorea, Regina Coeli Cunha; Hioka, Noboru; Silveira, Thaís Gomes Verzignassi

    2011-08-01

    The aim of this study was to investigate the effectiveness of Photodynamic Therapy (PDT) using Methylene Blue (MB) as the photosensitizing compound and a Light-Emitting Diode (LED) in American cutaneous leishmaniasis (ACL). Hamsters were experimentally infected with Leishmania (Leishmania) amazonensis. After the development of the lesions in the footpad, the animals were treated with MB three times a week for 3 months. Ten minutes after each application of MB, the lesions were irradiated with LED for 1 h. The lesions were evaluated weekly by the measurement of the hamster footpad thickness. At the end of the treatment the parasitic load was quantified in the regional lymph node of the hamsters. The treatment promoted a decrease in the thickness of infected footpad (P=0.0001) and reduction in the parasitic load in the regional lymph node (P=0.0007) of the animals from group treated with MB+LED. PDT using MB+LED in ACL caused by L. amazonensis shows a strong photodynamic effect. This therapy is very promising, once it is an inexpensive system and the own patient can apply it in their wound and in their house without the need of technical assistance. PMID:21575635

  6. Effect of electrostatic interaction on the methylene blue and methyl orange adsorption by the pristine and functionalized carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Robati, D.; Bagheriyan, S.; Rajabi, M.; Moradi, O.; Peyghan, A. Ahmadi

    2016-09-01

    Multi-walled carbon nanotubes (MWCNTs) were functionalized with cysteamine groups by several percentage of mass as adsorbents, then kinetics adsorption capacity was investigated for methylene blue (MB) and methyl orange (MO) as anionic and cationic dyes adsorbate molecules, respectively. The effect of temperature (from 283 to 303 K), contact time and initial concentration of the MB and MO dyes in a solution (10 to 40 ppm) was considered. The optimal contact time was found to be about 60 min. Some kinetics model such as pseudo-first-order, pseudo-second-order, intra-particle diffusion and the Elovich were tested. The adsorptions of MB dye on the pristine and functionalized MWCNT surfaces were found to be the intra-particle diffusion and the pseudo-second-order kinetic model, respectively and for adsorption of MO dye by the pristine and low functionalized MWCNTs and highly functionalized tubes, found to be the pseudo-second-order and intra-particle diffusion kinetic model, respectively, based on the chi-square statistic (X2) and also high correlation coefficient (R2) values.

  7. Clay honeycomb monoliths for water purification: Modulating methylene blue adsorption through controlled activation via natural coal templating

    NASA Astrophysics Data System (ADS)

    Gatica, José M.; Gómez, Diana M.; Harti, Sanae; Vidal, Hilario

    2013-07-01

    Texturally modified clay honeycomb monoliths were prepared for use as filters to remove pollutants from water solutions. An easy, economical, "green chemistry" activation route was employed during the preparation to enhance the adsorption capacity of the honeycombs. The method involves mixing the clay before its extrusion with a natural coal that is subsequently eliminated from the monolith by heating it under air at the lowest possible temperature (440 °C according to a thermogravimetric study). The size of the coal particles used as a template was intentionally modified by adjusting the milling process (dry or wet) and its duration (1-120 min) to modulate the porosity induced in the clay monoliths after their further burning. N2 physisorption, mercury porosimetry, granulometry and SEM were used to investigate the influence of the above preparative variables on the textural properties of the clay, significant effects being found in the macropore range. Methylene blue adsorption tests under dynamic conditions suggest that there is a correlation between pollutant removal and the macropore structure generated. FTIR spectroscopy indicates that the differences observed in cationic dye adsorption over the monoliths must be related to their different texture rather than to differences in the nature of their surface hydroxyl groups.

  8. Sorption and Desorption Behaviors of Methylene Blue in Soils Amended with Rice-Straw Ash and Biochar

    NASA Astrophysics Data System (ADS)

    Liu, Xinzhong; Chen, Rongguo; Weng, Rengui; Chen, Yilan; Peng, Lei; Xiu, Furong

    2012-06-01

    The ash (Ash) and biochar (BC) derived from the partial combustion of rice-straw are ubiquitous in soils and sediments and can potentially affect the environmental fate of organic contaminants. In this study, the effects of Ash and BC on the sorption and desorption behaviors of methylene blue (MB) were investigated. Ash was obtained from the direct burning of the rice-straw, and BC was separated from Ash by HCl treatment. SEM, BET, FT-IR, and pore size distribution analyses were used to characterize the Ash and BC prepared. Sorption capacities of MB on Ash-amended soil (AS) and BC-amended soil (BS) increased significantly with increasing contents of Ash and BC in soils. Sorption isotherms of soil amended with various amounts of Ash or BC fitted better to the Langmuir equation. The significant increase of apparent desorption hysteresis could be observed with increasing content of Ash or BC in the soils, especially in the case of BC, presumably due to the presence of micropores, hydroxyl groups and relatively higher specific surface area. It is believed that the presence of small amounts of BC produced from the rice-straw-derived ash in soil can have a marked effect on the transfer behavior of dye contaminations.

  9. Synthesis of cyclotriphosphazene-containing polymeric nanotubes and their use as metal-free photocatalysts for methylene blue degradation

    NASA Astrophysics Data System (ADS)

    Li, Zhenke; Wang, Guanghui; Liang, Chen; Zhang, Aiqing

    2015-08-01

    Highly cross-linked, organic-inorganic hybrid polymer nanotubes with primary amine groups on the surface have been successfully prepared through a facile polycondensation of hexachlorocyclotriphosphazene and melamine in absence of any surfactants or template agents. Then, these nanotubes were used as visible light photocatalysts for the degradation of methylene blue (MB) in water and the physicochemical properties of catalysts were characterized by several techniques. The as-synthesized nanotubes were closed at one end with a micrometer-scale in length (about 3-10 μm), 200-300 nm in the diameter, and the inner diameters of the two ends of each nanotube was 100-200 nm and 5-10 nm, respectively. A large amount of free radicals (rad OH) were generated in aqueous phase under visible light irradiation, which can photocatalytically oxidize and eventually mineralize. And, the progress of degradation was similar with semiconductor materials. The simple preparation method and photocatalytic performance of the cyclotriphosphazene-containing polymeric nanotubes represent an important step towards photocatalytic reaction in general where artificial conjugated polymer semiconductors can be used as energy transducers.

  10. Phenylethynyl Containing Reactive Additives

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

    2002-01-01

    Phenylethynyl containing reactive additives were prepared from aromatic diamine, containing phenylethvnvl groups and various ratios of phthalic anhydride and 4-phenylethynviphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pvrrolidinone to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.

  11. The effect of methylene dimethanesulphonate (MDMS) on the conformation of DNA and its dependence on base composition.

    PubMed

    Poppitt, D G; Fox, B W

    1975-09-01

    The interaction of the alkanesulphonate, methylene dimethanesulphonate (MDMS) with DNA has been studied. Thermal denaturation studies on mixtures of MDMS and DNA showed a dose-dependent decrease of the melting temperature midpoint (Tm) of the DNA. In addition, an irreversible decrease in ultraviolet absorption (hypochromism) preceded the hyperchromic shift, the magnitude of the former being linearly related to both the relative concentration of MDMS and the G-C content of the DNA used. Neither the reduction in melting temperature nor the initial UV absorption decrease occurred after dialysis of the reaction mixture. Equimolar proportions of the hydrolysis products of MDMS did not give the same effects as observed with the unhydrolysed agent. A similar hypochromism followed by strand separation occurs when DNA is allowed to stand with MDMS at room temperature, the time of subsequent strand separation being related to the treatment level of the drug. A weak association of MDMS with DNA is considered to be involved resulting in a local compression of the helical structure in the vicinity of the G-C pairs. It is suggested that this conformational change may act as a substrate for repair enzymes in vivo. PMID:168977

  12. Adsorption and photodegradation of methylene blue by iron oxide impregnated on granular activated carbons in an oxalate solution

    NASA Astrophysics Data System (ADS)

    Kadirova, Zukhra C.; Katsumata, Ken-ichi; Isobe, Toshihiro; Matsushita, Nobuhiro; Nakajima, Akira; Okada, Kiyoshi

    2013-11-01

    The photocatalytic adsorbents BAU-OA, BAU-CL and BAU-HA with varying iron oxide content (9-10 mass%) were prepared by heat treatment at 250 °C from commercial activated carbon (BAU) impregnated with iron oxalate, chloride, tris-benzohydroxamate, respectively. The XRD patterns showed amorphous structure in the BAU-CL sample (SBET 50 m2/g) and low crystallinity (as FeOOH and Fe2O3 phases) in the BAU-HA and BAU-OA samples (SBET 4 and 111 m2/g, respectively). The methylene blue adsorption capacities was decreased in order of BAU-OA < BAU-CL < BAU-HA sample and the adsorption followed Langmuir model. The apparent MB photodegradation rate constant (kapp) was increased in same order BAU-HA < BAU-CL < BAU-OA under the standard experimental conditions (initial MB concentrations 0.015-0.025 mM; sample content - 10 mg/l; initial oxalic acid concentration - 0.43 mM; pH 3-4; UV illumination). The process included high efficiency combination of adsorption, heterogeneous and homogeneous catalysis under UV and solar lights illumination without addition of hydrogen peroxide. The detoxification of water sample containing organic dyes was confirmed after combined sorption-photocatalytic treatment.

  13. Antifungal Action of Methylene Blue Involves Mitochondrial Dysfunction and Disruption of Redox and Membrane Homeostasis in C. albicans.

    PubMed

    Ansari, Moiz A; Fatima, Zeeshan; Hameed, Saif

    2016-01-01

    Candida albicans is known to cause infections ranging from superficial and systemic in immunocompromised person. In this study, we explored that the antifungal action of Methylene blue (MB) is mediated through mitochondrial dysfunction and disruption of redox and membrane homeostasis against C. albicans. We demonstrated that MB displayed its antifungal potential against C. albicans and two clinical isolates tested. We also showed that MB is effective against two non- albicans species as well. Notably, the antifungal effect of MB seems to be independent of the major drug efflux pumps transporter activity. We explored that MB treated Candida cells were sensitive on non-fermentable carbon source leading us to propose that MB inhibits mitochondria. This sensitive phenotype was reinforced with the fact that sensitivity of Candida cells to MB could be rescued upon the supplementation of ascorbic acid, an antioxidant. This clearly suggests that disturbances in redox status are linked with MB action. We further demonstrated that Candida cells were susceptible to membrane perturbing agent viz. SDS which was additionally confirmed by transmission electron micrographs showing disruption of membrane integrity. Moreover, the ergosterol levels were significantly decreased by 66% suggesting lipid compositional changes due to MB. Furthermore, we could demonstrate that MB inhibits the yeast to hyphal transition in C. albicans which is one of the major virulence attribute in most of the hyphal inducing conditions. Taken together, the data generated from present study clearly establishes MB as promising antifungal agent that could be efficiently employed in strategies to treat Candida infections. PMID:27006725

  14. Enhanced photoluminescence properties of methylene blue dye encapsulated in nanosized hydroxyapatite/silica particles with core-shell structure

    NASA Astrophysics Data System (ADS)

    Ge, Xiaolu; Li, Chengfeng; Fan, Chengyu; Feng, Xiaoxing; Cao, Bingqiang

    2013-11-01

    Organic dye of methylene blue (MB) was encapsulated in core-shell structured hydroxyapatite/silica particles (HAp/silica-MB) through a modified Stöber method with the addition of polyvinylpyrrolidone molecules. It was found that MB molecules were released from HAp/silica-MB at a slower rate than those from silica-MB in deionized water. In phosphate buffered saline (pH: 7.2-7.4) and acidic solutions (pH: 1.5-1.6), the penetration of ions in the interface influenced the interaction between HAp and MB molecules, which resulted in the rapid release of MB molecules from HAp/silica-MB. From the UV-Vis absorbance spectra, one could see that MB molecules in HAp/silica-MB were weakly aggregated in comparison with those in silica-MB. For HAp/silica-MB, enhanced luminescence properties were observed in the photoluminescence spectra and dual luminescence with two emission peaks were caused by the presence of monomers and dimers. Contrarily, no photoluminescence emission was detected for samples of free MB and silica-MB under the same excitation condition because of the self-quenching effect. It was the adsorption of MB molecules on HAp that had resulted in the enlargement of intramolecular distance and the reduction of self-quenching effect. These hybrid particles with enhanced luminescent properties might find wide applications in the field of bioanalysis, bioseparation, and biomedical imaging.

  15. Synthesis and high-efficiency methylene blue adsorption of magnetic PAA/MnFe2O4 nanocomposites

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Ding, Zui; Cai, Minhan; Jian, Haitao; Zeng, Zhiqiao; Li, Feng; Liu, J. Ping

    2015-08-01

    MnFe2O4 nanoparticles and polyacrylic acid PAA/MnFe2O4 nanocomposites were synthesized by a hydrothermal method and ultrasonic mixing process. The obtained materials were characterized by XRD, FTIR, SEM, TEM, and VSM. XRD patterns indicate that the synthesized MnFe2O4 nanoparticles have a single cubic spinel phase. SEM images confirm the existence of three types of basic morphology of MnFe2O4 nanoparticles: octahedral, flower-like, and plate-like particles. High saturation magnetization Ms (up to 74.6 emu/g) of the as-synthesized MnFe2O4 nanoparticles was obtained. Experiments demonstrate that the variation of the hydrothermal reaction time does not remarkably affect the magnetic properties of MnFe2O4 nanoparticles. In PAA/MnFe2O4 nanocomposites, the coating of PAA leads to a slight decrease in magnetization of MnFe2O4 nanoparticles. Additionally, PAA coating greatly enhances the adsorption properties of MnFe2O4 nanoparticles for Methylene Blue (MB) dye. Especially, the removal efficiency reaches 96.3%. This research indicates that the as-synthesized PAA/MnFe2O4 nanocomposites exhibit excellent magnetic properties and can be taken as a promising adsorbent for removal of MB dye in industrial scale.

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

    PubMed

    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. PMID:3375164

  17. A study of the methylene/perfluormethylene selectivity of porous polymer monolithic stationary phases exhibiting different fluorous/hydrophobic content.

    PubMed

    Xu, Zhenpo; Oleschuk, Richard D

    2014-02-14

    Porous polymer monolithic columns are prepared from a variety of monomers and cross-linkers and can be customized to exhibit different selectivities for separate analyte classes. The composition of the monolith can be precisely controlled by selecting different monomers and or cross-linker ratios. In this work monoliths exhibiting both fluorous and hydrophobic character were prepared using butyl methacrylate and its fluorous analogue (monomer) and 1,3-butanediol diacrylate and its fluorous analogue (cross-linker) in different ratios. The selectivity of the monoliths was probed using capillary electrochromatography with several fluorous and alkyl benzene analytes. Hydrophobic stationary phases exhibited greater methylene selectivity ( [Formula: see text] ) while those with increasing fluorous character show enhanced pefluoromethylene selectivity ( [Formula: see text] ). The Gibbs free energy change associated with the sorption of the analytes on each stationary phase composition can be calculated from migration times (i.e. capacity factor) for the addition of an individual -CF2- or -CH2- moiety. Furthermore, the Gibbs free energy change associated with a single -CF2- or -CH2- moiety (analyte) interacting with an individual -CF2- or -CH2- (stationary phase) can also be estimated by plotting fluorous column composition against [Formula: see text] . Furthermore [Formula: see text] and [Formula: see text] can be plotted versus H2O percentage in mobile phase, and a new concept, hypothetical water percentage (HWP) is proposed to evaluate the hydrophobicity/fluorophilicity of a stationary phase. PMID:24461637

  18. Antifungal Action of Methylene Blue Involves Mitochondrial Dysfunction and Disruption of Redox and Membrane Homeostasis in C. albicans

    PubMed Central

    Ansari, Moiz A.; Fatima, Zeeshan; Hameed, Saif

    2016-01-01

    Candida albicans is known to cause infections ranging from superficial and systemic in immunocompromised person. In this study, we explored that the antifungal action of Methylene blue (MB) is mediated through mitochondrial dysfunction and disruption of redox and membrane homeostasis against C. albicans. We demonstrated that MB displayed its antifungal potential against C. albicans and two clinical isolates tested. We also showed that MB is effective against two non- albicans species as well. Notably, the antifungal effect of MB seems to be independent of the major drug efflux pumps transporter activity. We explored that MB treated Candida cells were sensitive on non-fermentable carbon source leading us to propose that MB inhibits mitochondria. This sensitive phenotype was reinforced with the fact that sensitivity of Candida cells to MB could be rescued upon the supplementation of ascorbic acid, an antioxidant. This clearly suggests that disturbances in redox status are linked with MB action. We further demonstrated that Candida cells were susceptible to membrane perturbing agent viz. SDS which was additionally confirmed by transmission electron micrographs showing disruption of membrane integrity. Moreover, the ergosterol levels were significantly decreased by 66% suggesting lipid compositional changes due to MB. Furthermore, we could demonstrate that MB inhibits the yeast to hyphal transition in C. albicans which is one of the major virulence attribute in most of the hyphal inducing conditions. Taken together, the data generated from present study clearly establishes MB as promising antifungal agent that could be efficiently employed in strategies to treat Candida infections. PMID:27006725

  19. Facile decolorization of methylene blue by morphology-dependence δ-MnO2 nanosheets -modified diatomite

    NASA Astrophysics Data System (ADS)

    Yu, Ting Ting; Li, Kai Lin; Guo, Xiao Long; Li, Fei; Huang, Jia Mu; Zhang, Yu Xin

    2015-12-01

    In this work, coscinodiscus-diatomite and melosira-diatomite have been decorated by ultrathin birnessite MnO2 (δ-MnO2) nanosheets through a one-pot hydrothermal method without using any surfactants. The δ-MnO2 nanosheets are observed to grow vertically on the purified melosira-diatomite as well as coscinodiscus-diatomite. Moreover, the two composites exhibit high efficiency for decomposing methylene blue (MB) in the presence of H2O2. The coscinodiscus-diatmite@MnO2 achieves a removal rate of 81.8% (2 h), and yet melosira-diatomite@MnO2 reaches a higher degradation rate of 91.3% in 2 h. Additionally, the effects of catalyst amount, catalysis reaction temperature, preparing time have also been investigated. In principle, the diverse diatomite@MnO2 nanostructures not only present an environmentally friendly and low cost with a good cycling stability, but also offer a simple way for the catalytic degradation of dye waste water in practical applications.

  20. Bacterial photodynamic inactivation mediated by methylene blue and red light is enhanced by synergistic effect of potassium iodide.

    PubMed

    Vecchio, Daniela; Gupta, Asheesh; Huang, Liyi; Landi, Giacomo; Avci, Pinar; Rodas, Andrea; Hamblin, Michael R

    2015-09-01

    The inexorable increase of antibiotic resistance occurring in different bacterial species is increasing the interest in developing new antimicrobial treatments that will be equally effective against multidrug-resistant strains and will not themselves induce resistance. One of these alternatives may be photodynamic inactivation (PDI), which uses a combination of nontoxic dyes, called photosensitizers (PS), excited by harmless visible light to generate reactive oxygen species (ROS) by type 1 (radical) and type 2 (singlet oxygen) pathways. In this study, we asked whether it was possible to improve the efficacy of PDI in vitro and in vivo by addition of the inert salt potassium iodide (KI) to a commonly investigated PS, the phenothiazinium dye methylene blue (MB). By adding KI, we observed a consistent increase of red light-mediated bacterial killing of Gram-positive and Gram-negative species in vitro and in vivo. In vivo, we also observed less bacterial recurrence in wounds in the days posttreatment. The mechanism of action is probably due to formation of reactive iodine species that are produced quickly with a short lifetime. This finding may have a relevant clinical impact by reducing the risk of amputation and, in some cases, the risk of death, leading to improvement in the care of patients affected by localized infections. PMID:26077247

  1. Fabrication of Fluoropolymer Microtubes via RAFT Copolymerization of N,N'-Methylene Bisacrylamide Gel Fibers and Fluoromonomer.

    PubMed

    Li, Qi; Wang, Yi; Tang, Liming

    2015-06-01

    Fluoropolymer microtubes with a smooth surface were fabricated in more than 70 % yield via reversible addition fragmentation chain transfer (RAFT) co-polymerization of N,N'-methylene bisacrylamide (MBA) gel fibers as both template and monomer, 2-(perfluoro-3-methylbutyl)ethyl acrylate (R-3420) as co-monomer, and pentaerythritol tetraacrylate (PET4A) as cross-linker. The resulting fluoropolymer microtubes were characterized fully by SEM, TEM, EDS, XPS, and FT-IR. The influence of the monomer composition on the yields and morphologies of the tubes were investigated in detail. The results indicated that polymer microtubes with a smooth surface were obtained at suitable amounts of R-3420 and PET4A. Because of the decreased solubility of MBA gel fibers, the wall thickness increased as more R-3420 was used. In the presence of PET4A, the solution polymerization could be facilitated and more R-3420 could be attached onto the tubes based on FT-IR analysis. The water contact angle and swelling ratio measurements both revealed the low hydrophilicity and high lipophilicity of the fluoropolymer microtubes, which made the sample able to absorb toluene selectively in a water/toluene two-phase system. PMID:25786386

  2. A facile modification of g-C3N4 with enhanced photocatalytic activity for degradation of methylene blue

    NASA Astrophysics Data System (ADS)

    Chang, Fei; Xie, Yunchao; Li, Chenlu; Chen, Juan; Luo, Jieru; Hu, Xuefeng; Shen, Jiaowen

    2013-09-01

    In this investigation, a facile modification of g-C3N4 through co-pyrolysis of melamine and sodium nitrate or potassium nitrate was reported and the as-synthesized samples were characterized by a collection of techniques, such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-vis diffuse reflectance spectroscopy, nitrogen adsorption-desorption, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and elemental analysis. Based upon the analysis, we speculated that the g-C3N4 framework was partially destroyed to produce cyano-containing fragments, which resulted into the variation of physical and optical properties, further affecting the adsorption and photocatalytic performance of g-C3N4 on the dye methylene blue. Furthermore, we found that nitrate anions rather than sodium or potassium ions had important effect on the structure and photocatalytic performance of g-C3N4. In addition, the photocatalysis mechanism and reusability test were also investigated and discussed in the study.

  3. Bacterial Photodynamic Inactivation Mediated by Methylene Blue and Red Light Is Enhanced by Synergistic Effect of Potassium Iodide

    PubMed Central

    Vecchio, Daniela; Gupta, Asheesh; Huang, Liyi; Landi, Giacomo; Avci, Pinar; Rodas, Andrea

    2015-01-01

    The inexorable increase of antibiotic resistance occurring in different bacterial species is increasing the interest in developing new antimicrobial treatments that will be equally effective against multidrug-resistant strains and will not themselves induce resistance. One of these alternatives may be photodynamic inactivation (PDI), which uses a combination of nontoxic dyes, called photosensitizers (PS), excited by harmless visible light to generate reactive oxygen species (ROS) by type 1 (radical) and type 2 (singlet oxygen) pathways. In this study, we asked whether it was possible to improve the efficacy of PDI in vitro and in vivo by addition of the inert salt potassium iodide (KI) to a commonly investigated PS, the phenothiazinium dye methylene blue (MB). By adding KI, we observed a consistent increase of red light-mediated bacterial killing of Gram-positive and Gram-negative species in vitro and in vivo. In vivo, we also observed less bacterial recurrence in wounds in the days posttreatment. The mechanism of action is probably due to formation of reactive iodine species that are produced quickly with a short lifetime. This finding may have a relevant clinical impact by reducing the risk of amputation and, in some cases, the risk of death, leading to improvement in the care of patients affected by localized infections. PMID:26077247

  4. Evaluation of a soil-flushing remediation project for a methylene chloride spill in Vinton County, Ohio

    SciTech Connect

    Stewart, R.J. )

    1992-01-01

    The CSX-Zaleski site covers approximately one acre and is located immediately east of the Village of Zaleski. A rail car derailed at this site in November of 1984, spilling 20,000 gallons of methylene chloride into a water-filled low area adjacent to the railroad grade. Initial response included the installation of two purge wells and an air stripping tower. Heterogeneous soils and poor recharge conditions at the site resulted in an upgraded system being installed which included nine purge wells, three sumps and 15 monitoring wells. This system was operated until August 1985 when it was discontinued because of insufficient recharge rates. In 1990, after further site evaluation, Ohio EPA determined that additional remediation was necessary. A pilot test was run at the site to determine the feasibility of a soil vapor extraction (SVE) system. The site was found to be unsuitable for a SVE system because of heterogeneous soil permeabilities. In 1991, a soil flushing system was installed and operated for four months. A significant removal of the remaining contaminant was observed. Monitoring to date indicates that the decreases in contaminant levels is permanent.

  5. The Synthesis and Anion Recognition Property of Symmetrical Chemosensors Involving Thiourea Groups: Theory and Experiments

    PubMed Central

    Shang, Xuefang; Yang, Zhenhua; Fu, Jiajia; Zhao, Peipei; Xu, Xiufang

    2015-01-01

    The synthesis of four symmetrical compounds containing urea/thiourea and anthracene/nitrobenzene groups was optimized. N,N’-Di((anthracen-9-yl)-methylene)thio-carbonohydrazide showed sensitive and selective binding ability for acetate ion among the studied anions. The presence of other competitive anions including F−, H2PO4−, Cl−, Br− and I− did not interfere with the strong binding ability. The mechanism of the host-guest interaction was through multiple hydrogen bonds due to the conformational complementarity and higher basicity. A theoretical investigation explained that intra-molecular hydrogen bonds existed in the compound which could strengthen the anion binding ability. In addition, molecular frontier orbitals in molecular interplay were introduced in order to explain the red-shift phenomenon in the host-guest interaction process. Compounds based on thiourea and anthracene derivatives can thus be used as a chemosensor for detecting acetate ion in environmental and pharmaceutical samples. PMID:26561816

  6. Characteristic intraepidermal nerve fibre endings of the intervibrissal fur in the mystacial pad of the rat: morphological details revealed by intravital methylene blue staining and the zinc iodide-osmium tetroxide technique

    PubMed Central

    MÜLLER, T.

    1999-01-01

    Light microscopic observations employing intravital methylene blue staining and impregnation by the zinc iodide-osmium tetroxide technique are presented for intraepidermal nerve fibre endings of the intervibrissal fur in the mystacial pad of the rat snout. Both procedures revealed anatomical details of the intraepidermal nerve fibre plexus in epidermal hillocks often located very close to the mouths of hairs. These nerve fibres appeared to resemble those described in previous immunohistochemical studies as cluster or bush endings. The methylene blue preparations demonstrated the existence of an intensely stained enlargement at the site of the branching point of the nerve fibres which seemed to be functionally related to the development of such nerve fibre plexuses. Due to their close association with hairs, these nerve fibre plexuses are most likely to be mechanoreceptive. Additionally, solitary varicose nerve fibres were found loosely distributed within the epidermis. The visualisation of 2 different morphological types of nerve fibre endings extends the validity of the concept of punctate sensibility into the epidermis. Methylene blue staining appeared to be somewhat superior to the zinc iodide-osmium tetroxide technique. Due to their selectivity for intraepidermal nerve fibres, the methods applied here supplement immunohistochemical procedures in a helpful manner. PMID:10473302

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

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-, (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...

  8. 40 CFR 721.8485 - 2-Propenoic acid, 2-methyl-, (octahydro-4,7-methano-1H- indene-5-diyl)bis(methylene) ester.

    Code of Federal Regulations, 2010 CFR

    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...

  9. Direct targeted glycation of the free sulfhydryl group of cysteine residue (Cys-34) of BSA. Mapping of the glycation sites of the anti-tumor Thomsen-Friedenreich neoglycoconjugate vaccine prepared by Michael addition reaction.

    PubMed

    Demian, Wael L L; Kottari, Naresh; Shiao, Tze Chieh; Randell, Edward; Roy, René; Banoub, Joseph H

    2014-12-01

    We present in this manuscript the characterization of the exact glycation sites of the Thomsen-Friedenreich antigen-BSA vaccine (TF antigen:BSA) prepared using a Michael addition reaction between the saccharide antigen as an electrophilic acceptor and the nucleophilic thiol and L-Lysine ε-amino groups of BSA using different ligation conditions. Matrix laser desorption ionization time-of-flight mass spectrometry of the neoglycoconjugates prepared with TF antigen:protein ratios of 2:1 and 8:1, allowed to observe, respectively, the protonated molecules for each neoglycoconjugates: [M + H](+) at m/z 67,599 and 70,905. The measurements of these molecular weights allowed us to confirm exactly the carbohydrate:protein ratios of these two synthetic vaccines. These were found to be closely formed by a TF antigen:BSA ratios of 2:1 and 8:1, respectively. Trypsin digestion and liquid chromatography coupled with electrospray ionization mass spectrometry allowed us to identify the series of released glycopeptide and peptide fragments. De novo sequencing affected by low-energy collision dissociation tandem mass spectrometry was then employed to unravel the precise glycation sites of these neoglycoconjugate vaccines. Finally, we identified, respectively, three diagnostic and characteristic glycated peptides for the synthetic glycoconjugate possessing a TF antigen:BSA ratio 2:1, whereas we have identified for the synthetic glycoconjugate having a TF:BSA ratio 8:1 a series of 14 glycated peptides. The net increase in the occupancy sites of these neoglycoconjugates was caused by the large number of glycoforms produced during the chemical ligation of the synthetic carbohydrate antigen onto the protein carrier. PMID:25476939

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

    SciTech Connect

    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.

  11. Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric α-Cr2O3(0001)

    NASA Astrophysics Data System (ADS)

    Dong, Yujung; Brooks, John D.; Chen, Tsung-Liang; Mullins, David R.; Cox, David F.

    2015-11-01

    The reaction of iodomethane on the nearly stoichiometric α-Cr2O3(0001) surface produces gas phase ethylene, methane, and surface iodine adatoms. The reaction is initiated by the dissociation of iodomethane into surface methyl fragments, - CH3, and iodine adatoms. Methyl fragments bound at surface Cr cation sites undergo a rate-limiting dehydrogenation reaction to methylene, = CH2. The methylene intermediates formed from methyl dehydrogenation can undergo coupling reactions to produce ethylene via two principle reaction pathways: (1) direct coupling of methylene and (2) methylene insertion into the methyl surface bond to form surface ethyl groups which undergo β-H elimination to produce ethylene. The liberated hydrogen also combines with methyl groups to form methane. Iodine adatoms from the dissociation of iodomethane deactivate the surface by simple site blocking of the surface Cr3 + cations.

  12. Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric α-Cr2O3(0001)

    DOE PAGESBeta

    Dong, Yujung; Brooks, John D.; Chen, Tsung-Liang; Mullins, David R.; Cox, David F.

    2015-06-10

    The reaction of iodomethane on the nearly stoichiometric α-Cr2O3(0001) surface produces gas phase ethylene, methane, and surface iodine adatoms. The reaction is first initiated by the dissociation of iodomethane into surface methyl fragments, -CH3, and iodine adatoms. Methyl fragments bound at surface Cr cation sites undergo a rate-limiting dehydrogenation reaction to methylene, =CH2. The methylene intermediates formed from methyl dehydrogenation can then undergo coupling reactions to produce ethylene via two principle reaction pathways: (1) direct coupling of methylene and (2) methylene insertion into the methyl surface bond to form surface ethyl groups which undergo β-H elimination to produce ethylene. Themore » liberated hydrogen also combines with methyl groups to form methane. Iodine adatoms from the dissociation of iodomethane deactivate the surface by simple site blocking of the surface Cr3+ cations.« less

  13. Encapsulation of methylene blue in polyacrylamide nanoparticle platforms protects its photodynamic effectiveness.

    PubMed

    Tang, Wei; Xu, Hao; Park, Edwin J; Philbert, Martin A; Kopelman, Raoul

    2008-05-01

    The ability to prevent methylene blue (MB), a photosensitizer, from being reduced by plasma reductases will greatly improve its efficacy in photodynamic therapy (PDT) applications. We have developed a delivery approach for PDT by encapsulating MB using nanoparticle platforms (NPs). The 30-nm polyacrylamide-based NPs provide protection for the embedded MB against reduction by diaphorase enzymes. Furthermore, our data shows the matrix-protected MB efficiently induces photodynamic damage to tumor cells. The unprecedented results demonstrate the significant in vitro photodynamic effectiveness of MB when encapsulated within NPs, which promises to open new opportunities for MB in its in vivo and clinical studies. PMID:18298950

  14. Methylene blue sensitized gelatin as a photosensitive medium for conventional and polarizing holography.

    PubMed

    Solano, C; Lessard, R A; Roberge, P C

    1987-05-15

    The properties of thin gelatin films sensitized with a dye (methylene blue) when used as a holographic material are discussed. On illumination the excited dye molecule changes its structure giving a colorless molecule. The higher rate of bleaching and therefore the higher diffraction efficiency of the developed phase gratings are obtained in an oxygen-free atmosphere. Furthermore, the light absorption probability of the dye molecules depends on its position with respect to the electric vector of the light, with the result that the exposed part of the dye becomes dichroic when illuminated with linearly polarized light. This result allows the use of this material for polarizing holography. PMID:20454433

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

    PubMed

    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. PMID:26574897

  16. Manganese dioxide modified silicon nanowires and their excellent catalysis in the decomposition of methylene blue

    NASA Astrophysics Data System (ADS)

    Gao, Weiwei; Shao, Mingwang; Yang, Li; Zhuo, Shujuan; Ye, Shiyong; Lee, Shuit-tong

    2012-02-01

    A redox between hydrofluoric acid and ammonium fluoride-treated silicon nanowires and potassium permanganate solution was investigated. The results showed that MnO2 nanoparticles might grow on the surface of silicon nanowires, which was confirmed with the transmission electron microscope. These MnO2 modified silicon nanowires were employed as catalysts in the decomposition of methylene blue using sodium borohydride as the reducing agent, which exhibited excellent catalysis with its reaction rate 6 times larger than the unsupported MnO2.

  17. Technetium 99m-methylene diphosphonate bone scans in children with reflex neurovascular dystrophy

    SciTech Connect

    Laxer, R.M.; Allen, R.C.; Malleson, P.N.; Morrison, R.T.; Petty, R.E.

    1985-03-01

    Eleven children with reflex neurovascular dystrophy were investigated by technetium-labeled methylene diphosphonate bone scanning. Eight of 12 scans demonstrated abnormal findings, four showing diffusely decreased uptake and four diffusely increased uptake of the radionuclide in the affected site. Three scans showed normal findings initially, as did one previously abnormal scan when repeated in the asymptomatic patient 6 months later. Diffusely abnormal findings can be helpful in the diagnosis of childhood reflex neurovascular dystrophy, but a normal scan does not exclude the diagnosis.

  18. Adsorption of methylene blue dye from aqueous solutions using Eichhornia crassipes.

    PubMed

    Wanyonyi, Wycliffe Chisutia; Onyari, John Mmari; Shiundu, Paul Mwanza

    2013-09-01

    Adsorption of methylene blue (MB) from aqueous solution using dried roots, stems, and leaves of Eichhornia crassipes biomass obtained from Lake Victoria was studied. Batch experimental results revealed that the adsorption process was highly dependent on adsorbent dosage, initial MB concentration, E. crassipes particle size and aqueous solution temperature. The isotherm data fitted Freundlich mathematical models with maximum dye adsorption of 35.37 mg g(-1). Roots adsorbed over 99 % of the MB in <5 min. Sorption kinetics followed a pseudo-second-order model. Results provide evidence that E. crassipes is an effective and inexpensive biomaterial for dye removal from aqueous dye solutions and industrial effluents. PMID:23839152

  19. An uncommon case showing three different pathologies on 99mtechnetium-methylene diphosphonate bone scintigraphy

    PubMed Central

    Chakraborty, Partha Sarathi; Karunanithi, Sellam; Dhull, Varun Singh; Kumar, Kunal; Gupta, Ravikant; Tripathi, Madhavi

    2015-01-01

    99mTechnetium-methylene diphosphonate bone scintigraphy (BS) has an important role in evaluating skeletal pathology, especially its extent. Incidental extra-osseous uptake may sometimes be seen in soft-tissue pathologies. We present a 64-year-old female with skull base osteomyelitis referred for BS which revealed involvement of the skull base on the left side, uptake was also noted in bilateral lungs secondary to hypercalcemia of renal failure and in the D12-L1 vertebrae as the patient had a history of Pott's spine. This is perhaps a unique case showing three findings each of a different etiology in the same scan. PMID:25589816

  20. Fluxional behavior of a cadmium zwitterion complex: proton transport and tautomerism in methylene chloride solution.

    PubMed

    Anderson, Oren P; la Cour, Agnete; Berg, Andrew; Garrett, Andrew D; Wicholas, Mark

    2003-07-28

    The synthesis and structure of the tautomeric Cd(II) isoindoline zwitterion coordination compound [Cd(4'-MeLH)(NO(3))(2)].CH(3)OH (4'-MeLH = 1,3-bis[2-(4-methylpyridyl)imino]isoindoline) are reported. In methylene chloride solution, tautomer interconversion occurs as the N-H proton moves between the identical imine nitrogen atoms. We report the kinetics of proton transfer as followed by variable temperature (1)H NMR spectroscopy and demonstrate that methanol of solvation and adventitious water facilitate rapid proton transfer. PMID:12870937

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

    PubMed Central

    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/cm2 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. PMID:22802686

  2. Impact of methylene blue and atorvastatin combination therapy on the apparition of cerebral malaria in a murine model

    PubMed Central

    2013-01-01

    Background Proveblue®, a methylene blue dye that complies with European Pharmacopoeia and contains limited organic impurities and heavy metals of recognized toxicity, showed in vitro synergy against Plasmodium falciparum when combined with atorvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl-Coenzyme A reductase. The objective of this study was to evaluate the in vivo efficacy of Proveblue® when combined with atorvastatin in a murine model of experimental cerebral malaria. Methods Forty female C57Bl6/N mice were divided into four groups (control, atorvastatin 40 mg/kg for seven days, Proveblue® 10 mg/kg for five days and atorvastatin combined with Proveblue®), infected with Plasmodium berghei ANKA parasites by intraperitoneal inoculation and observed for 45 days. Results Treatment with atorvastatin alone did not demonstrate an effect significantly different from no treatment (p = 0.0573). All the mice treated by atorvastatin alone died. Treatment with Proveblue® or a combination of Proveblue® and atorvastatin was significantly increased survival of cerebral malaria (p = 0.0011 and 0.0002, respectively). Although there was only one death in the atorvastatin and Proveblue® combination treatment group (10%) versus two deaths (22%) with Proveblue® treatment, the effect on cerebral malaria was not significant (p = 0.283). Conclusions The present work demonstrated, for the first time, the high efficacy of Proveblue® in preventing cerebral malaria. Atorvastatin alone or in combination appears to possess limited use for preventing cerebral malaria. Combination of atorvastatin with lower doses of Proveblue® (<10 mg/kg/day) should be evaluated to show potential synergistic effects in cerebral malaria prevention. PMID:23587099

  3. Comparison of raw and modified activated carbon and rice industry wastes for methylene blue sorption

    NASA Astrophysics Data System (ADS)

    Befani, Maria; Manariotis, Ioannis D.; Karapanagioti, Hrissi K.; Quintero, César E.

    2015-04-01

    In Argentina the average paddy rice production was 1.3x106 tn/year in the last decade. Entre Ríos province (E.R.) accounts for 60% of national milling, resulting in a significant accumulation of waste in the local environment; husk and ashes are used as fuel in drying grain plants. The use of rice wastes, as low-cost sorbents for the removal of synthetic dyes and other contaminants may be a sustainable option. The aim of this work is the investigation of the removal capacity of methylene blue (MB) from aqueous solutions using: (a) rice husk from a rice mill located in E.R. of size between 0.15 to 1.18 mm (RH2), (b) ash from rice husk burned at 800°C in oven for the grain drying unit of the rice mill (RHA800), and (c) biochar obtained from pyrolysis of RH2 material at 850°C (RHA4). Commercial activated carbon (AC), which is a porous material of high sorption capacity, was also used to compare its sorption capacity with the rice husk products. Furthermore, the incorporation of iron in the AC was studied using two different AC/Fe weight-by-weight ratios (AC-Fe and AC-0.5 Fe). The solution pH effect was studied in a range from 2 to 6.9. The maximal MB removal was achieved at pH of 6.8 to 6.9 for all materials studied, and at pH of 6.4 for AC. Kinetic experiments were conducted for a period of 48 h at pH 7 and C0 = 50 mg MB/L. Equilibrium was reached after 24 h and the adsorption capacity was 156, 104, 90, 79, 26, and 9 mg/g for AC, AC-Fe, AC-0.5 Fe, RHA4, RH2 and RHA800, respectively. The pseudo-second-order model expressed better the sorption kinetics of MB for all adsorbent materials. The AC-based materials presented better performance. The experimental data were fitted with the Freundlich and Langmuir isotherm models. The Langmuir model fits the data better in all cases. The maximum adsorption capacity was 238, 125, 92, 91, 46 and 9 mg/g for AC, AC-Fe, AC-0.5 Fe, RHA4, RH2 and RHA800, respectively. Agricultural wastes can be considered low-cost sorbents, but

  4. Hydrocarbon fuel additive

    SciTech Connect

    Ambrogio, S.

    1989-02-28

    This patent describes the method of fuel storage or combustion, wherein the fuel supply contains small amounts of water, the step of adding to the fuel supply an additive comprising a blend of a hydrophilic agent chosen from the group of ethylene glycol, n-butyl alcohol, and cellosolve in the range of 22-37% by weight; ethoxylated nonylphenol in the range of 26-35% by weight; nonylphenol polyethylene glycol ether in the range of 32-43% by weight.

  5. Spectroscopic investigation on interaction and sonodynamic damage of Riboflavin to DNA under ultrasonic irradiation by using Methylene Blue as fluorescent probe

    NASA Astrophysics Data System (ADS)

    Wang, Qi; Wu, Qiong; Wang, Jun; Chen, Dandan; Fan, Ping; Wang, Baoxin

    2014-01-01

    In this paper, the Riboflavin (RF) as a sonosensitizer and Methylene Blue (MB) as a fluorescent probe were used to study the interaction and sonodynamic damage to Deoxyribonucleic Acid (DNA) by fluorescence and UV-vis spectroscopy. The results showed that the RF could efficiently bind to DNA in aqueous solution and exchange with the MB through competing reaction. And then, under ultrasonic irradiation, the RF could obviously damage the DNA. In addition, the influencing factors such as ultrasonic irradiation time and RF concentration on the sonodynamic damage to DNA were also considered. The experimental results showed that the sonodynamic damage degree increase with the increase of ultrasonic irradiation time and RF concentration. Perhaps, this paper may offer some important subjects for broadening the application of RF in sonodynamic therapy (SDT) technologies for tumor treatment.

  6. Spectroscopic investigation on interaction and sonodynamic damage of Riboflavin to DNA under ultrasonic irradiation by using Methylene Blue as fluorescent probe.

    PubMed

    Wang, Qi; Wu, Qiong; Wang, Jun; Chen, Dandan; Fan, Ping; Wang, Baoxin

    2014-01-01

    In this paper, the Riboflavin (RF) as a sonosensitizer and Methylene Blue (MB) as a fluorescent probe were used to study the interaction and sonodynamic damage to Deoxyribonucleic Acid (DNA) by fluorescence and UV-vis spectroscopy. The results showed that the RF could efficiently bind to DNA in aqueous solution and exchange with the MB through competing reaction. And then, under ultrasonic irradiation, the RF could obviously damage the DNA. In addition, the influencing factors such as ultrasonic irradiation time and RF concentration on the sonodynamic damage to DNA were also considered. The experimental results showed that the sonodynamic damage degree increase with the increase of ultrasonic irradiation time and RF concentration. Perhaps, this paper may offer some important subjects for broadening the application of RF in sonodynamic therapy (SDT) technologies for tumor treatment. PMID:24094993

  7. The impact of crystallization conditions on structure-based drug design: A case study on the methylene blue/acetylcholinesterase complex.

    PubMed

    Dym, Orly; Song, Wanling; Felder, Clifford; Roth, Esther; Shnyrov, Valery; Ashani, Yacov; Xu, Yechun; Joosten, Robbie P; Weiner, Lev; Sussman, Joel L; Silman, Israel

    2016-06-01

    Structure-based drug design utilizes apoprotein or complex structures retrieved from the PDB. >57% of crystallographic PDB entries were obtained with polyethylene glycols (PEGs) as precipitant and/or as cryoprotectant, but <6% of these report presence of individual ethyleneglycol oligomers. We report a case in which ethyleneglycol oligomers' presence in a crystal structure markedly affected the bound ligand's position. Specifically, we compared the positions of methylene blue and decamethonium in acetylcholinesterase complexes obtained using isomorphous crystals precipitated with PEG200 or ammonium sulfate. The ligands' positions within the active-site gorge in complexes obtained using PEG200 are influenced by presence of ethyleneglycol oligomers in both cases bound to W84 at the gorge's bottom, preventing interaction of the ligand's proximal quaternary group with its indole. Consequently, both ligands are ∼3.0Å further up the gorge than in complexes obtained using crystals precipitated with ammonium sulfate, in which the quaternary groups make direct π-cation interactions with the indole. These findings have implications for structure-based drug design, since data for ligand-protein complexes with polyethylene glycol as precipitant may not reflect the ligand's position in its absence, and could result in selecting incorrect drug discovery leads. Docking methylene blue into the structure obtained with PEG200, but omitting the ethyleneglycols, yields results agreeing poorly with the crystal structure; excellent agreement is obtained if they are included. Many proteins display features in which precipitants might lodge. It will be important to investigate presence of precipitants in published crystal structures, and whether it has resulted in misinterpreting electron density maps, adversely affecting drug design. PMID:26990888

  8. Decomposition of Methylene Blue by using an Atmospheric Plasma Jet with Ar, N2, O2, or Air

    NASA Astrophysics Data System (ADS)

    Takemura, Yuichiro; Yamaguchi, Naohiro; Hara, Tamio

    2013-05-01

    We have performed experiments on the decomposition of methylene blue by using an atmospheric plasma jet with various working gases. The decomposition efficiencies of Ar, N2, and O2 plasmas are almost equivalent; on the other hand, the rate of methylene blue decomposition by air plasma is lower than those by the other plasmas. From the absorption spectra, it has been found that HONO (nitrous acid) is produced by air plasma-liquid reactions. It has been clarified by a series of experiments, where oxygen concentration in N2 plasma is varied, that the concentration of HONO increases and the rate of methylene blue decomposition degrades with increasing oxygen gas flow rate. Furthermore, the presence of nitrate ions and nitrite ions was confirmed by ion chromatography and pH measurement.

  9. In Situ XANES Study of CuO/TiO2 Thin Films During Photodegradation of Methylene Blue

    SciTech Connect

    Hsiung Tungli; Wang, H. Paul; Wei Yuling

    2007-02-02

    Speciation of copper in the CuO/TiO2 thin film (synthesized by the doctor-blade deposition method) during photocatalytic decomposition of methylene blue has been studied by in situ X-ray absorption near-edge structural (XANES) spectroscopy. During the UV/VIS radiation (90 min), in the presence of methylene blue, a decrease of Cu(II) and an increases of Cu(0) and Cu(I) fractions in the CuO/TiO2 thin film are observed by in situ XANES. The r-space Fourier transformation EXAFS (extend X-ray absorption fine structural) spectra also show that the bond distance of Cu-O in the thin film is decreased by 0.03 A during photocatalytic degradation of methylene blue.

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

    PubMed

    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 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. PMID:27236206

  11. Kinetic studies on the adsorption of methylene blue onto vegetal fiber activated carbons

    NASA Astrophysics Data System (ADS)

    Cherifi, Hakima; Fatiha, Bentahar; Salah, Hanini

    2013-10-01

    The vegetable sponge of cylindrical loofa (CL), a natural product which grows in the north of Algeria, was used to prepare activated carbons. Two activated carbons, AC1 and AC2, by two physiochemical activation methods to be used for methylene blue removal from wastewater. The surface structure of AC1, AC2 and CL were analyzed by scanning electron microscopy. Adsorption isotherm of methylene blue onto the prepared activated carbons was determined by batch tests. The effects of various parameters such as contact time, initial concentration, pH, temperature, adsorbent dose and granulometry were investigated, at agitation rate 150 rpm. The results showed that the equilibrium uptake increased with increasing initial MB concentration. The maximum % removal of MB obtained was 99% at 50 °C for AC1 and 82% at 30 °C for AC2. The increase in initial pH in the ranges of 2-10 increases the yields removal of MB on AC2. The pseudo-first-order and pseudo-second-order kinetic models were applied to test the experimental data. The latter provided the best correlation of the experimental data compared to the pseudo-first-order model.

  12. Electron transfer in the quenching of protonated triplet thionine and methylene blue by ground state thionine

    SciTech Connect

    Kamat, P.V.; Lichtin, N.N.

    1981-01-01

    Use of thiazine dyes, e.g., thionine and methylene blue, in the conversion of light energy into electrical energy has been studied extensively in recent years. Despite continuing efforts to improve the performance of photogalvanic cells, the highest reported engineering efficiency for photogalvanic conversion of sunlight into electricity is still less than 0.1%. One of the proposed steps to increase efficiency is to employ high concentrations of light-absorbing dye, e.g., 0.1 M. However, use of such high concentrations of dye may lead to wastage of absorbed quantum energy via a variety of processes, one of which is quenching of triplet dye by ground-state dye. A study of such ground-state quenching of protonated triplet methylene blue, /sup 3/MBH/sup 2 +/, with efficiency of net electron transfer in quenching, F/sub 1/, less than 0.5 was reported previously. Quenching without net electron-transfer inevitably reduces the conversion efficiency of photogalvanic cells. The results of a laser flash-photolytic, kinetic spectrometric study of kinetics and mechanism of quenching of protonated triplet thionine, /sup 3/TH/sub 2//sup 2 +/, and /sup 3/MBH/sup 2 +/ by ground-state thionine, TH/sup +/, in water, aqueous CH/sub 3/CN and aqueous ethanol are presented.

  13. Potential Biosorbent Derived from Calligonum polygonoides for Removal of Methylene Blue Dye from Aqueous Solution

    PubMed Central

    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 (R2) 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. PMID:25705714

  14. Structural characteristics of mixed oxides MOx/SiO2 affecting photocatalytic decomposition of methylene blue

    NASA Astrophysics Data System (ADS)

    Gun'ko, V. M.; Blitz, J. P.; Bandaranayake, B.; Pakhlov, E. M.; Zarko, V. I.; Sulym, I. Ya.; Kulyk, K. S.; Galaburda, M. V.; Bogatyrev, V. M.; Oranska, O. I.; Borysenko, M. V.; Leboda, R.; Skubiszewska-Zięba, J.; Janush, W.

    2012-06-01

    A series of photocatalysts based on silica (nanoparticulate) supported titania, ceria, and ceria/zirconia were synthesized and characterized by a variety of techniques including surface area measurements, X-ray diffraction, Fourier transform infrared spectroscopy, zeta potential, surface charge density, and photocatalytic behavior toward methylene blue decomposition. Thermal treatment at 600 °C increases the anatase content of the titania based catalysts detected by XRD. Changes in the infrared spectra before and after thermal treatment indicate that at low temperature there are more tbnd Sisbnd Osbnd Titbnd bonds than at high temperature. As these bonds break upon heating the SiO2 and TiO2 separate, allowing the TiO2 anatase phase to form. This results in an increased catalytic activity for the thermally treated samples. Nearly all titania based samples exhibit a negative surface charge density at pH 7 (initial pH of photocatalytic studies) which aids adsorption of methylene blue. The crystallinity of ceria and ceria/zirconia based catalysts are in some cases limited, and in others non-existent. Even though the energy band gap (Eg) can be lower for these catalysts than for the titania based catalysts, their photocatalytic properties are inferior.

  15. A fraction of methylene chloride from Geum japonicum Thunberg inhibits tumor metastatic and angiogenic potential.

    PubMed

    Heo, Jin-Chul; Son, Minsik; Woo, Sang-Uk; Kweon, Mi-Ae; Yoon, Eun Kyung; Lee, Hee Kyung; Choi, Won-Sik; Cho, Kang-Jin; Lee, Sang-Han

    2008-06-01

    The plant Geum japonicum Thunberg (GjT) has been used as a diuretic in traditional medicine. Herein, we report that the GjT extract blocks both the spread of human umbilical vein endothelial cells (HUVECs) on matrigel and the migration of B16 cells. We used various assays to test for cell attachment, spreading, wound healing and angiogenesis. A reverse transcription-polymerase chain reaction (RT-PCR) and a mitogen-activated protein kinase (MAPK) assay were also carried out for the mechanistic study of GjT. Our results showed that a fraction of methylene chloride fraction from GjT inhibited B16 cells during cell attachment and migration and suppressed tube formation in a dose-dependent manner. An RT-PCR analysis showed that the methylene chloride extract decreased the mRNA expression of CD44 and TIMP-2. A Western blot analysis of the phosphorylation of MAPK kinases (ERK, JNK and p38) showed that the GjT fraction increased the expression of phospho-JNK, suggesting that GjT has the potential to alleviate metastatic and angiogenic activity, via a phospho-JNK signaling pathway. PMID:18497943

  16. Headspace gas chromatographic determination of methylene chloride in decaffeinated tea and coffee, with electrolytic conductivity detection.

    PubMed

    Page, B D; Charbonneau, C F

    1984-01-01

    A headspace gas chromatographic procedure is described for the determination of methylene chloride (MC) in decaffeinated tea and coffee. The tea or coffee sample, with added methylene bromide (MB) internal standard, is equilibrated for 1.5 h at 100 degrees C in aqueous sodium sulfate before manual headspace sampling. MC and MB are separated on a Porasil A column at 160 degrees C and detected by using a Coulson electrolytic conductivity detector. For coffee and tea samples spiked at 1.3 ppm MC, as well as commercially decaffeinated teas and coffees containing up to 8 ppm MC, coefficients of variation were 10% or less. For decaffeinated teas, problems involving sample homogeneity and loss of MC before sealing the headspace vial had to be overcome. Similar problems with decaffeinated instant and ground coffees were minimal. The headspace procedure was superior to a previously reported distillation technique. MC was readily detected at 0.05 ppm. Fourteen decaffeinated teas and 15 decaffeinated coffees were analyzed; MC was detected at levels that ranged up to 15.9 and 4.0 ppm, respectively. PMID:6469909

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

    PubMed

    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. PMID:25705714

  18. Development of new 5-(chromene-3-yl)methylene-2,4-thiazolidinediones as antimicrobial agents

    PubMed Central

    NASTASĂ, CRISTINA MARIANA; DUMA, MIHAELA; PÎRNĂU, ADRIAN; VLASE, LAURIAN; TIPERCIUC, BRÎNDUŞA; ONIGA, OVIDIU

    2016-01-01

    Background and aims In the context of the increasing phenomenon of microbial resistance to usual drugs, the development of new treatment strategies and new therapeutic protocols is a constant need. Thiazolidinedione and chromone represent two important scaffolds in medicinal chemistry due to their large pharmacological applicability. Methods We synthesized a new 5-(chromene-3-yl)methylene-2,4-thiazolidinedione starting from 6,8-dichloro-4-oxo-4H-chromene-3-carbaldehyde. Then, by treating with different α-bromoalkylarylketones, we obtained N-substituted derivatives. All new compounds were investigated for their antimicrobial potential, using the diffusion method, against Listeria monocytogenes ATCC 13932, Staphylococcus aureus ATCC 49444, Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 14028 and Candida albicans ATCC 10231. Three concentrations, 10 mg/ml, 5 mg/ml and 1 mg/ml of compounds were used. The results were evaluated by the measurement of the inhibition zone diameters and compared to those of gentamicin and fluconazole respectively, as reference drugs. Results All new synthesized compounds were characterized using physico-chemical and spectrometric methods. They displayed modest to good antimicrobial activity. New molecules 8, 9 and 10 may represent promising candidates, showing zone inhibition diameters superior to those of reference drugs. Conclusions This work presents chemical synthesis, characterization and investigation of the antibacterial and antifungal potential of 5-(chromene-3-yl)methylene-2,4-thiazolidinedione derivatives, which may be worthy of future research for designing new chemical entities. PMID:27004035

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Extractive spectrophotometric determination of some nonsteroidal anti-inflammatory drugs using methylene blue.

    PubMed

    El-Kommos, Michael E; Mohamed, Niveen A; Hakiem, Ahmed F Abdel

    2013-01-01

    A simple, rapid, sensitive, and accurate extractive spectrophotometric method has been developed for the determination of seven nonsteroidal anti-inflammatory drugs (NSAIDs)--namely diclofenac sodium, ibuprofen, indomethacin, ketoprofen, ketorolac tromethamine, mefenamic acid, and naproxen-in pure forms as well as their pharmaceutical dosage forms (tablets, capsules, effervescent granules, syrups, oral drops, ampules, eye drops, gels, and suppositories). The method depends on the formation of an intensely colored ion-pair complex between the acidic drug and methylene blue in alkaline medium. The complex is stable and extractable into methylene chloride. All parameters were optimized. Beer-Lambert's law was obeyed in concentrations ranging from 0.04 to 9 microg/mL. Statistical analysis of the calibration data was carried out, and correlation coefficients were in the range from 0.9996 to 0.9998. The developed method was fully validated according to International Conference on Harmonization guidelines, and complied with U.S. Pharmacopeia guidelines. The proposed method was applied to the analysis of the investigated drugs in their pharmaceutical formulations, and good recoveries were obtained. The results obtained were compared with those of reported and official methods, and no significant differences were found with t- and F-tests. Interference effects of some compounds usually present in combination with NSAIDs were studied, and the tolerance limits of these compounds were determined. PMID:24000745

  1. Methylene blue treatment delays progression of perfusion-diffusion mismatch to infarct in permanent ischemic stroke

    PubMed Central

    Rodriguez, Pavel; Jiang, Zhao; Huang, Shiliang; Shen, Qiang; Duong, Timothy Q

    2016-01-01

    Stroke is a leading cause of morbidity and mortality in the world. Low-dose methylene blue (MB), which has been used safely to treat methemoglobinemia and cyanide poisoning in humans, has energy enhancing and antioxidant properties. We tested the hypothesis that methylene blue treatment delays progression of at-risk tissue (ca. perfusion-diffusion mismatch) to infarct in permanent middle cerebral artery occlusion in rats at two MB treatment doses. Serial MRI was used to evaluate MB treatment efficacy. The major findings were: (i) MB significantly prolonged the perfusion-diffusion mismatch, (ii) MB mildly increased the CBF in the hypoperfused tissue, (iii) MB did not change the final infarct volume in permanent ischemic stroke, and (iv) there were no dose-dependent effects on mismatch progression for the 1 and 3mg/kg doses studied. This neuroprotective effect is likely the result of sustained ATP production and increased CBF to tissue at risk. This work has the potential to readily lead to clinical stroke trials given MB's excellent safety profile. PMID:25218555

  2. Methylene chloride mortality study: dose-response characterization and animal model comparison.

    PubMed

    Hearne, F T; Grose, F; Pifer, J W; Friedlander, B R; Raleigh, R L

    1987-03-01

    To assess the potential chronic health effects of methylene chloride, the mortality experience of a maturing 1964 to 1970 cohort of 1,013 hourly men was evaluated through 1984. On average, employees were exposed at a rate of 26 ppm (eight-hour time-weighted average) for 22 years; median latency was 30 years. Compared with the general population, no statistically significant excesses were observed for such hypothesized causes as lung cancer (14 observed v 21.0 expected), liver cancer (0 v 0.8), and ischemic heart disease (69 v 98.1); dose-response relationships based on career methylene chloride exposure and latency were not demonstrated. Among nonhypothesized causes, a significant deficit was reported for total deaths (176 v 253.2). None of the industrial referent comparisons achieved statistical significance. Sufficient power was available to detect relative risks of 1.6 for lung malignancy and 1.3 for ischemic heart disease. In contrast, there was inadequate power to identify meaningful risk levels for hepatic cancer. With 14 combined lung and liver cancer deaths observed v 36.3 predicted (P less than .0001), the mortality estimate projected from a mathematical model derived from an animal bioassay substantially overestimated cancer mortality for these sites. This inconsistency emphasizes the need to incorporate epidemiologic evidence in assessing the human health risks associated with long-term exposure to this widely used solvent. PMID:3559766

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

    PubMed

    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. PMID:26724726

  4. Effects of feed additives and mixed eimeria species infection on intestinal microbial ecology of broilers.

    PubMed

    Hume, M E; Clemente-Hernández, S; Oviedo-Rondón, E O

    2006-12-01

    Evaluation of digestive microbial ecology is necessary to understand effects of growth-promoting feed. In the current study, the dynamics of intestinal microbial communities (MC) were examined in broilers fed diets supplemented with a combination of antibiotic (bacitracin methylene disalicylate) and ionophore (Coban 60), and diets containing 1 of 2 essential oil (EO) blends, Crina Poultry (CP) and Crina Alternate (CA). Five treatments were analyzed: 1) unmedicated uninfected control; 2) unmedicated infected control; 3) feed additives monensin (bacitracin methylene disalicylate) + monensin (Coban 60; AI); 4) EO blend CP; and 5) EO blend CA. Additives were mixed into a basal feed mixture, and EO were adjusted to 100 ppm. Chicks were infected by oral gavage at 19 d of age with Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Duodenal, ileal, and cecal samples were taken from 12 birds per treatment just before and 7 d after challenge; 2 samples each were pooled to give a final number of 6 samples total; and all pooled samples were frozen until used for DNA extraction. Denaturing gradient gel electrophoresis was used to examine PCR-amplified fragments of the bacterial 16S ribosomal DNA variable region. Results are presented as percentages of similarity coefficients (SC). Dendrograms of PCR amplicon or band patterns indicated MC differences due to intestinal location, feed additives, and cocci challenge. Essential oil blends CP and CA affected MC in all gut sections. Each EO had different effects over MC, and they differed in most instances from the AI group. The cocci challenge caused drastic MC population shifts in duodenal, ileal, and cecal sections (36.7, 55.4, and 36.2% SC, respectively). Diets supplemented with CP supported higher SC between pre- and postchallenge MC (89.9, 83.3, and 76.4%) than AI (81.8., 57.4, and 60.0%). We concluded that mixed coccidia challenge caused drastic shifts in MC. These EO blends modulated MC better than AI, avoiding drastic

  5. Optical properties of human maxillary sinus mucosa and estimation of Methylene Blue diffusion coefficient in the tissue

    NASA Astrophysics Data System (ADS)

    Bashkatov, Alexey N.; Genina, Elina A.; Kochubey, Vyacheslav I.; Tuchin, Valery V.; Chikina, Elena E.; Knyazev, Anatoly B.; Mareev, Oleg V.

    2005-06-01

    The optical properties of human maxillary sinus mucosa were measured in the wavelength range 400-2000 nm. The measurements were carried out using the commercially available spectrophotometer with the integrating sphere. The inverse adding-doubling method has been used to determine the absorption and reduced scattering coefficients from the measurements. Diffusion of Methylene Blue in the mucous tissue has been studied in vitro and value of the diffusion coefficient of Methylene Blue in the tissue has been estimated at 20°C as (4.77+/-2.9)x10-7 cm2/sec.

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

    PubMed

    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. PMID:27077228

  7. Dicarboxylic acid anhydride condensation with compounds containing active methylene groups. 4: Some 4-nitrophthalic anhydride condensation reactions

    NASA Technical Reports Server (NTRS)

    Oskaja, V.; Rotberg, J.

    1985-01-01

    By 4-nitrophthalic anhydride condensation with acetoacetate in acetic anhydride and triethylamine solution with subsequent breakdown of the intermediate condensation product, 5-nitroindanedione-1,3 was obtained. A 4-nitrophthalic anhydride with acetic anhydride, according to reaction conditions, may yield two products: in the presence of potassium acetate and at high temperatures 4-(or 5-)-nitro-2-acetylbenzoic acid is formed: in the presence of triethylamine and at room temperature 5-( or 6-)-nitrophthalic acetic acid is isolated. A 4-nitrophthalic anhydride and malonic acid in pyridine solution according to temperature yield either 5-( or 6-)-nitrophthalic acetic acid or 4-(or 5-)-nitro-2-acetylbenzoic acid.

  8. Synthesis and molecular characterization of 5,5‧-((2,4-dichlorophenyl)methylene)bis(1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione)

    NASA Astrophysics Data System (ADS)

    Barakat, Assem; Al-Najjar, Hany J.; Al-Majid, Abdullah Mohammed; Soliman, Saied M.; Mabkhot, Yahia Nasser; Ghabbour, Hazem A.; Fun, Hoong-Kun

    2015-03-01

    A simple, economical, and green approach to the synthesis of 5,5‧-((2,4-dichlorophenyl)methylene)bis(1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione) 4 using a tandem Aldol condensation-Michael addition process in aqueous diethylamine medium was described. The 3D structure of the latter was confirmed by single-crystal X-ray structure determination. The molecular structure of the titled compound was calculated using DFT B3LYP/6-311G(d,p) method. The calculated geometric parameters are in good agreement with the experimental data obtained from our reported X-ay structure. The two pyrimidinetrione rings have C16 and C20 atoms deviated significantly from the ring plane. The electronic spectra of the studied compound have been calculated using the TD-DFT method. The longest wavelength band (257.8 nm, f = 0.0276) occurs due to H → L (86%) transition. The 1H and 13C NMR calculated chemical shifts using GIAO method showed good correlation with the experimental data. The molecular electrostatic potential (MEP) showed that the most reactive sites for electrophilic and nucleophilic attacks are the carbonyl oxygen (O5) and the H21 atoms, respectively. The NBO calculations were performed to predict the natural atomic charges at the different atomic sites and to study the different intramolecular charge transfer (ICT) interactions occurring in the studied system. Interestingly, there is some delocalization of electron densities from the occupied σ-type NBO of the C20sbnd H21 to the unoccupied π∗-NBO of the two adjacent carbonyl groups.

  9. Cantor Groups

    ERIC Educational Resources Information Center

    Mathes, Ben; Dow, Chris; Livshits, Leo

    2011-01-01

    The Cantor subset of the unit interval [0, 1) is "large" in cardinality and also "large" algebraically, that is, the smallest subgroup of [0, 1) generated by the Cantor set (using addition mod 1 as the group operation) is the whole of [0, 1). In this paper, we show how to construct Cantor-like sets which are "large" in cardinality but "small"…

  10. The role of oxidative stress genes and effect of pH on methylene blue sensitized photooxidation of Escherichia coli.

    PubMed

    İdil, Önder; Macit, İkbal; Kaygusuz, Özge; Darcan, Cihan

    2016-03-01

    In this study, the survival time of wild type E. coli W3110 and 11 mutants was analysed with a plate count method in methylene blue added or control groups under daylight fluoroscence illumination (4950 lux) at different pH values (5.0, 6.0, 7.0, and 8.0) in phosphate buffer. As a result, while the number of bacteria did not decrease under photooxidative stress at pH 5.0 and 6.0 during a 6-hour incubation, the wild type and all mutants decreased more than 2 log. at pH 8.0, and approximately one log. at pH 7.0. It was determined that a 2 log decrease in wild type E. coli takes 3.7 h according to t99 value at pH 8, these values were 2.39 h in the katE mutant, 2.64 h in the soxR mutant, 2.67 h in the oxyR mutant, 2.71 h in the sodB mutant, 3 h in the btuE mutant, 3.38 h in the zwf mutant and 3.40 h in the soxS mutant, respectively (p < 0.05). The roles of these genes were proved with complement tests. Finally, it is found that the effectiveness of photooxidative stress is in direct relation with pH, and the katE, soxR, oxyR, sodB, btuE, zwf, and soxS genes are important for the protection against this stress. PMID:26960359

  11. γ-Fe2O3 nanocrystals-anchored macro/meso-porous graphene as a highly efficient adsorbent toward removal of methylene blue.

    PubMed

    Zhang, Lian Ying; Zhang, Wenlin; Zhou, Zhiqin; Li, Chang Ming

    2016-08-15

    An adsorbent, γ-Fe2O3 nanocrystals-anchored macro/meso-porous graphene was synthesized by metal etching approach toward removal of methylene blue, exhibiting rapid adsorption rate, high adsorption capacity and good recyclability, thus holding a great promise for treatment of methylene blue in wastewater. PMID:27218808

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

    PubMed

    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

  13. Designing and exploring active N'-[(5-nitrofuran-2-yl) methylene] substituted hydrazides against three Trypanosoma cruzi strains more prevalent in Chagas disease patients.

    PubMed

    Palace-Berl, Fanny; Pasqualoto, Kerly Fernanda Mesquita; Jorge, Salomão Dória; Zingales, Bianca; Zorzi, Rodrigo Rocha; Silva, Marcelo Nunes; Ferreira, Adilson Kleber; de Azevedo, Ricardo Alexandre; Teixeira, Sarah Fernandes; Tavares, Leoberto Costa

    2015-01-01

    Chagas disease affects around 8 million people worldwide and its treatment depends on only two nitroheterocyclic drugs, benznidazole (BZD) and nifurtimox (NFX). Both drugs have limited curative power in chronic phase of disease. Nifuroxazide (NF), a nitroheterocyclic drug, was used as lead to design a set of twenty one compounds in order to improve the anti-Trypanosoma cruzi activity. Lipinski's rules were considered in order to support drug-likeness designing. The set of N'-[(5-nitrofuran-2-yl) methylene] substituted hydrazides was assayed against three T. cruzi strains, which represent the discrete typing units more prevalent in human patients: Y (TcII), Silvio X10 cl1 (TcI), and Bug 2149 cl10 (TcV). All the derivatives, except one, showed enhanced trypanocidal activity against the three strains as compared to BZD. In the Y strain 62% of the compounds were more active than NFX. The most active compound was N'-((5-nitrofuran-2-yl) methylene)biphenyl-4-carbohydrazide (C20), which showed IC50 values of 1.17 ± 0.12 μM; 3.17 ± 0.32 μM; and 1.81 ± 0.18 μM for Y, Silvio X10 cl1, and Bug 2149 cl10 strains, respectively. Cytotoxicity assays with human fibroblast cells have demonstrated high selectivity indices for several compounds. Exploratory data analysis indicated that primarily topological, steric/geometric, and electronic properties have contributed to the discrimination of the set of investigated compounds. The findings can be helpful to drive the designing, and subsequently, the synthesis of additional promising drugs against Chagas disease. PMID:25899337

  14. Ni/Ti layered double hydroxide: synthesis, characterization and application as a photocatalyst for visible light degradation of aqueous methylene blue.

    PubMed

    Roy Chowdhury, Priyadarshi; Bhattacharyya, Krishna G

    2015-04-21

    Visible light responsive 2 : 1 Ni/Ti layered double hydroxide (LDH) was synthesized by a single step hydrothermal route using commercially available Ni(NO3)2·6H2O, TiCl4 and urea. The material exhibited significant absorption in the visible range with a very narrow band gap (2.68 eV). This could be attributed to structural defects as confirmed by diffuse reflectance spectroscopy (DRS), photoluminescence (PL), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) measurements. FT-IR, TGA, DTA, DSC, HR-TEM and SEM-EDX measurements yielded information about structural aspects, thermal stability and surface morphology. Surface and pore characteristics of the material were obtained from the BET isotherm for N2 adsorption at 77 K. Zeta potential measurements were used to characterize the electrical properties of the surface while XPS revealed changes in surface states and oxygen deficiencies. The material was found to be an excellent photocatalyst for the degradation of aqueous methylene blue in visible light. The photocatalytic properties of the material were explained on the basis of the narrow band gap, the high surface area and the presence of surface defects. The photocatalytic activity improved in alkaline media [pH 11.0, catalyst load 15 mg in 200 ml dye solution, dye concentration 1 × 10(-6) M (= 0.3198 mg L(-1))] due to the electrostatic attractions between the dye cations and the negative charges on the Ni/Ti LDH surface. The catalytic activity was found to be higher than the common commercial catalysts like ZnO, ZnS, NiO, TiO2 and Degussa P25. The catalytic activity was retained even after five methylene blue degradation cycles, demonstrating that the LDH could be an important addition to the field of wastewater treatment. PMID:25763803

  15. Effect of J coupling on 1.3-ppm lipid methylene signal acquired with localised proton MRS at 3 T.

    PubMed

    Breitkreutz, Dylan Y; Fallone, B Gino; Yahya, Atiyah

    2015-10-01

    The purpose of this work was to investigate the effect of J-coupling interactions on the quantification and T2 determination of 1.3-ppm lipid methylene protons at 3 T. The response of the 1.3-ppm protons of hexanoic, heptanoic, octanoic, linoleic and oleic acid was measured as a function of point-resolved spectroscopy (PRESS) and stimulated echo acquisition mode (STEAM) TE. In addition, a narrow-bandwidth refocusing PRESS sequence designed to rewind J-coupling evolution of the 1.3-ppm protons was applied to the five fatty acids, to corn oil and to tibial bone marrow of six healthy volunteers. Peak areas were plotted as a function of TE, and data were fitted to monoexponentially decaying functions to determine Mo (the extrapolated area for TE = 0 ms) and T2 values. In phantoms, rewinding J-coupling evolution resulted in 198%, 64%, 44%, 20% and 15% higher T2 values for heptanoic, octanoic, linoleic and oleic acid, and corn oil, respectively, compared with those obtained with standard PRESS. The narrow-bandwidth PRESS sequence also resulted in significant changes in Mo , namely -77%, -22%, 28%, 23% and 28% for heptanoic, octanoic, linoleic and oleic acid, and corn oil, respectively. T2 values obtained with STEAM were closer to the values measured with narrow-bandwidth PRESS. On average, in tibial bone marrow (six volunteers) rewinding J-coupling evolution resulted in 21% ± 3% and 9 % ± 1% higher Mo and T2 values, respectively. This work demonstrates that the consequence of neglecting to consider scalar coupling effects on the quantification of 1.3-ppm lipid methylene protons and their T2 values is not negligible. The linoleic and oleic acid T2 results indicate that T2 measures of lipids with standard MRS techniques are dependent on lipid composition. PMID:26314546

  16. A DFT study of addition reaction between fragment ion (CH₂) units and fullerene (C₆₀) molecule.

    PubMed

    Zaragoza, Irineo Pedro; Vergara, Jaime; Pérez-Manríquez, Liliana; Salcedo, Roberto

    2011-05-01

    The theoretical study of the interaction between CH(2) and fullerene (C(60)) suggests the existence of an addition reaction mechanism; this feature is studied by applying an analysis of electronic properties. Several different effects are evident in this interaction as a consequence of the particular electronic transfer which occurs during the procedure. The addition or insertion of the methylene group results in a process, where the inclusion of CH(2) into a fullerene bond produces the formation of several geometric deformations. A simulation of these procedures was carried out, taking advantage of the dynamic semi-classical Born-Oppenheimer approximation. Dynamic aspects were analyzed at different speeds, for the interaction between the CH(2) group and the two bonds: CC (6, 6) and CC (6, 5) respectively on the fullerene (C(60)) rings. All calculations which involved electrons employed DFT as well as exchange and functional correlation. The results indicate a tendency for the CH(2) fragment to attack the CC (6, 5) bond. PMID:20658255

  17. Boron addition to alloys

    SciTech Connect

    Coad, B. C.

    1985-08-20

    A process for addition of boron to an alloy which involves forming a melt of the alloy and a reactive metal, selected from the group consisting of aluminum, titanium, zirconium and mixtures thereof to the melt, maintaining the resulting reactive mixture in the molten state and reacting the boric oxide with the reactive metal to convert at least a portion of the boric oxide to boron which dissolves in the resulting melt, and to convert at least portion of the reactive metal to the reactive metal oxide, which oxide remains with the resulting melt, and pouring the resulting melt into a gas stream to form a first atomized powder which is subsequently remelted with further addition of boric oxide, re-atomized, and thus reprocessed to convert essentially all the reactive metal to metal oxide to produce a powdered alloy containing specified amounts of boron.

  18. Siloxane containing addition polyimides

    NASA Technical Reports Server (NTRS)

    Maudgal, S.; St. Clair, T. L.

    1984-01-01

    Addition polyimide oligomers have been synthesized from bis(gamma-aminopropyl) tetramethyldisiloxane and 3, 3', 4, 4'-benzophenonetetracarboxylic dianhydride using a variety of latent crosslinking groups as endcappers. The prepolymers were isolated and characterized for solubility (in amide, chlorinated and ether solvents), melt flow and cure properties. The most promising systems, maleimide and acetylene terminated prepolymers, were selected for detailed study. Graphite cloth reinforced composites were prepared and properties compared with those of graphite/Kerimid 601, a commercially available bismaleimide. Mixtures of the maleimide terminated system with Kerimid 601, in varying proportions, were also studied.

  19. The Effects of Self-Confrontation via TV and of Additional Training Components: Group Discussion, Discrimination Training, and Practice in a Scaled-Down Situation on the Indirectness of Teacher Trainees.

    ERIC Educational Resources Information Center

    Klinzing, Hans Gerhard; Klinzing-Eurich, Gisela

    Four experimental studies were conducted to assess the differences in effectiveness of self-confrontation via TV when used exclusively and in combination with group discussion, discrimination training (training in the use of interaction analysis), and practice in a scaled-down situation (peerteaching) on "the indirectness" of future secondary…

  20. Recovery of asphalt from methylene chloride and trichloroethylene by the abson method. Final report, November 1987-August 1989

    SciTech Connect

    Stuart, K.D.; Kumari, D.; Tran, K.T.

    1989-11-01

    The objective of the in-house study was to determine if methylene chloride (CH2Cl2) can be used to recover asphalts using the Abson method (AASHTO T 170 and ASTM D 1856), and to compare its effects on recovered binder properties to those of trichloroethylene (C2HCl3). Current nationally standardized test procedures (AASHTO and ASTM) do not allow methylene chloride in the Abson method. Virgin paving grade asphalts and hardened asphalts were used in the evaluation. Hardened asphalts consisted of paving grade asphalts aged by the thin film oven procedure, paving grade asphalts extracted from aged loose mixtures and cores, and coating grade roofing asphalts. The following tests were performed before and after recovering the asphalts from trichloroethylene or methylene chloride: penetration at 25 C, viscosity at 60 C, viscosity at 135 C, high pressure gel permeation chromatography, and infrared spectral analysis. The data indicated that methylene chloride can be used to recover asphalts from mixtures using the Abson method. Both solvents had some statistically significant effects on some asphalt properties, but neither solvent could clearly be recommended over the other.

  1. Developmental toxicity of copper chloride, methylene chloride, and 6-aminonicotinamide to embryos of the grass shrimp Palaemonetes pugio

    SciTech Connect

    Rayburn, J.R.; Fisher, W.S.

    1999-05-01

    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, copper chloride, and 6-aminonicotinamide, three known teratogenic chemicals. Two exposure periods were used, 4 d and 12 d, and both periods extended through hatching. The average 4-d LC50 values for methylene chloride, copper chloride, and 6-aminonicotinamide were 0.071% v/v, 1.82 mg/L, and 0.21 mg/ml, respectively. The average 12-d LC50 values for methylene chloride, copper chloride, and 6-aminonicotinamide were 0.031% v/v, 1.44 mg/L, and 0.057 mg/ml, respectively. Eye malformations were observed with embryos exposed to concentrations greater than 3 mg/L copper chloride or greater than 0.07% v/v methylene chloride. Very few abnormalities were observed in embryos exposed to 6-aminonicotinamide. Abnormal larval development was found with exposure to copper chloride at concentrations greater than 1 mg/L. The sensitivity and low variability found here further supports the development of these relatively simple methods using grass shrimp embryos. Establishment of sublethal developmental endpoints warrants further investigation because of their potential correspondence to mechanisms of toxic action.

  2. Successful Localization of Abnormal Parathyroid Gland Using Ultrasound-Guided Methylene Blue Dye Injection in the Reoperative Neck.

    PubMed

    Haciyanli, Mehmet; Koruyucu, Melike Bedel; Erdoğan, Nezahat Karaca; Dere, Ozcan; Sarı, Erdem; Kumkumoğlu, Yusuf; Tavusbay, Cengiz; Kamer, Erdinc

    2015-12-01

    Persistent or recurrent hyperparathyroidism is a challenging problem for endocrine surgeons. The aim of this study was to review our experience using ultrasound-guided (US-G) methylene blue dye injection for the localization and removal of abnormal parathyroid glands in patients having primary hyperparathyroidism and previous neck surgery. Between January 2012 and May 2013, six consecutive patients with primary hyperparathyroidism (PHPT) and previous neck surgery underwent focused parathyroidectomy with the use of US-G methylene blue dye injections to localize the presumed parathyroid adenoma were included in the study. We analyzed the data of six patients who underwent reoperative parathyroid surgery using US-G methylene blue dye injection retrospectively. The dye injection was performed just prior to surgery. All patients were successfully treated for their hyperparathyroidism which was confirmed by at least 50 % drop in intraoperative parathormone level 10 min after resection. There were no complications related with US-G dye injection or with surgery. US-G methylene blue dye injection is a cheap, safe, and effective method for localization of diseased parathyroid glands and guiding surgery in the reoperative neck. PMID:27011517

  3. DEMONSTRATION OF N-METHYL PYRROLIDONE (NMP) AS A POLLUTION PREVENTION ALTERNATIVE TO PAINT STRIPPING WITH METHYLENE CHLORIDE

    EPA Science Inventory

    This objective of this paper is to demonstrate that NMP is a viable pollution prevention alternative to methylene chloride. Maine Corps Logistics Base (MCLB), Albany, GA, USA was the host site for the demonstration. MCLB's primary function is maintenance of military ground supp...

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

    NASA Astrophysics Data System (ADS)

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

    2012-09-01

    Graphene sheets decorated with SnO2 nanoparticles (RGO-SnO2) were prepared via a redox reaction between graphene oxide (GO) and SnCl2. Graphene oxide (GO) was reduced to graphene (RGO) and Sn2+ was oxidized to SnO2 during the redox reaction, leading to a homogeneous distribution of SnO2 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-SnO2 composite showed an enhanced photocatalytic degradation activity for the organic dye methylene blue under sunlight compared to bare SnO2 nanoparticles. This result leads us to believe that the RGO-SnO2 composite could be used in catalytic photodegradation of other organic dyes.

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

    NASA Astrophysics Data System (ADS)

    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.

  6. The induction of apoptosis by a positively charged methylene blue derivative.

    PubMed

    Ball, D J; Luo, Y; Kessel, D; Griffiths, J; Brown, S B; Vernon, D I

    1998-02-01

    Identifying the cellular responses to photodynamic therapy (PDT) is important if the mechanisms of cell death are to be fully understood. PDT with a methylene blue analog DO15 yielded mitochondrial photodamage whilst membrane and lysosomal integrity were maintained. Apoptosis was detected using the DNA stain HO342, by the appearance of 50 kb fragments and by DNA ladder formation. The release of mono- and oligonucleosomes was further quantified using an ELISA protocol. Large DNA fragments were observed immediately following illumination, and nucleosomes were detected at 1-2 h post-treatment. Increasing the dose 4-fold accelerated the apoptotic response to PDT. This is the first report of a thiazine photosensitiser inducing apoptosis and is consistent with recent proposals suggesting that release of mitochondrial components may play an important role in the mechanism of cell death. PMID:9540222

  7. Removal of Methylene Blue and Orange-G from Waste Water Using Magnetic Biochar

    NASA Astrophysics Data System (ADS)

    Mubarak, N. M.; Fo, Y. T.; Al-Salim, Hikmat Said; Sahu, J. N.; Abdullah, E. C.; Nizamuddin, S.; Jayakumar, N. S.; Ganesan, P.

    2015-04-01

    The study on the removal of methylene blue (MB) and orange-G dyes using magnetic biochar derived from the empty fruit bunch (EFB) was carried out. Process parameters such as pH, adsorbent dosage, agitation speed and contact time were optimized using Design-Expert Software v.6.0.8. The statistical analysis reveals that the optimum conditions for the maximum adsorption of MB are at pH 2 and pH 10, dosage 1.0 g, and agitation speed and contact time of 125 rpm and 120 min respectively. While for orange-G, at pH 2, dosage 1.0 g, and agitation speed and contact time of 125 rpm and 120 min respectively. The maximum adsorption capacity of 31.25 mg/g and 32.36 mg/g for MB and orange-G respectively. The adsorption kinetic for both dyes obeyed pseudo-second order.

  8. Reactive extraction of lactic acid with trioctylamine/methylene chloride/n-hexane

    SciTech Connect

    Han, D.H.; Hong, W.H.

    1996-04-01

    The trioctylamine (TOA)/methylene chloride (MC)/n-hexane system was used as the extraction agent for the extraction of lactic acid. Curves of equilibrium and hydration were obtained at various temperatures and concentrations of TOA. A modified mass action model was proposed to interpret the equilibrium and the hydration curves. The reaction mechanism and the corresponding parameters which best represent the equilibrium data were estimated, and the concentration of water in the organic phase was predicted by inserting the parameters into the simple mathematical equation of the modified model. The concentration of MC and the change of temperature were important factors for the extraction and the stripping process. The stripping was performed by a simple distillation which was a combination of temperature-swing regeneration and diluent-swing regeneration. The type of inactive diluent has no influence on the stripping. The stripping efficiencies were about 70%.

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

    PubMed

    Bukkitgar, Shikandar D; Shetti, Nagaraj P

    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(-5)-1×10(-7)M and detection limit and quantification limit were calculated to be 2.04nM and 6.18nM respectively. Further, the sensor was successfully applied in pharmaceutical and biological fluid sample analysis. PMID:27157751

  10. Data on synthesis of methylene bisphosphonates and screening of their inhibitory activity towards HIV reverse transcriptase.

    PubMed

    Yanvarev, D V; Korovina, A N; Usanov, N N; Khomich, O A; Vepsäläinen, J; Puljula, E; Kukhanova, M K; Kochetkov, S N

    2016-09-01

    Inorganic pyrophosphate (PPi) mimetics designed on a basis of methylenediphosphonic acid backbone are promising inhibitors of two key HIV replication enzymes, IN [1] and RT [2]. Herein, we present chemical synthesis of eleven methylenebisphosphonates (BPs) with their NMR and HRMS analysis synthesized via five different ways. Also, we present data on inhibition of HIV RT catalyzed phosphorolysis and polymerization by synthesized BPs using two methods based on denaturing urea PAGE. Tests were also performed for thymidine analogue mutations reverse transcriptase (TAM RT), which was expressed and purified for that. Structure-activity relationships and inhibitory activity data of synthesized BPs are presented in "Methylene bisphosphonates as the inhibitors of HIV RT phosphorolytic activity" [2]. PMID:27547792

  11. Strong aggregation adsorption of methylene blue from water using amorphous WO3 nanosheets

    NASA Astrophysics Data System (ADS)

    Luo, Jian Yi; Cao, Zhi; Chen, Feng; Li, Li; Lin, Yu Rong; Liang, Bao Wen; Zeng, Qing Guang; Zhang, Mei; He, Xin; Li, Chen

    2013-12-01

    In this paper, authors demonstrate the high performance of the amorphous WO3 nanosheets in the removal of methylene blue (MB) from water. The saturated MB adsorbed amount by using WO3 nanosheets as an adsorbent can reach to 600 mg/g, exceeding the ones of the normal activated carbon powders. Results indicate that the aggregation of adsorbed MB molecules occurs in the porous micro-structures of the amorphous WO3 nanosheets, and a precipitation phenomenon begins to happen when the initial MB concentration reach to 20 mg/L or greater, attributed to the density increase of WO3 nanosheets after their porous micro-structures are adsorbed with enough MB molecules.

  12. Fluorescence tissue distribution of methylene blue used for photodynamic therapy of Helicobacter Pylori

    NASA Astrophysics Data System (ADS)

    Millson, Charles E.; Buonaccorsi, Giovanni A.; MacRobert, Alexander J.; Mlkvy, Peter; Bown, Stephen G.

    1995-03-01

    Helicobacter pylori is associated with a wide range of pathologies in the upper gastrointestinal tract. Current treatments employing antibiotics are disappointing, and an endoscopic PDT might offer a better alternative. Methylene blue is a widely known histological dye and has been in use for photodynamic therapy experimentally for some years. A prospective application of MB is photosensitization of Helicobacter pylori, but little is known about its effect with light on normal mucosa of the stomach. We studied the fluorescence microscopy of the stomachs of 3 ferrets which had been sensitized by oral route with three different concentrations of MB 1 hour prior to sacrifice. MB at all doses was seen to concentrate on the surface of the mucosa and shows little deeper penetration. As Helicobacter lie on the superficial mucosa, this study suggests that oral dosing with MB should sensitize these bacteria. These findings are an important preliminary to an in vivo trial of PDT for the treatment of H pylori.

  13. Novel alkylimidazolium/vanadium pentoxide intercalation compounds with excellent adsorption performance for methylene blue

    NASA Astrophysics Data System (ADS)

    Kong, AiGuo; Ding, Yong Jie; Wang, Ping; Zhang, Heng Qiang; Yang, Fan; Shan, Yong Kui

    2011-02-01

    Novel alkylimidazolium-intercalated V 2O 5 compounds were synthesized by a redox reaction between iodide ion and V 2O 5. The X-ray photoelectron spectroscopy and the diffuse reflectance UV-vis spectrometry experiments reveal that the vanadium in the intercalated V 2O 5 products was partially reduced by an iodide ion and the resultant iodine can be removed in the final products. The transmission electron microscope observation and X-ray diffraction analysis testify that the prepared alkylimidazolium/V 2O 5 intercalation compounds have typical lamellar structure with different d100 interlayer spacing values and the special straw-like nanofiber morphology with the length of 0.5-10 μm. Systematic investigation indicates that new intercalation compounds possess the extraordinary adsorption performance for methylene blue in an aqueous solution.

  14. Determination of Key Flavor Components in Methylene Chloride Extracts from Processed Grapefruit Juice.

    PubMed

    Jella; Rouseff; Goodner; Widmer

    1998-01-19

    The relative correlation of 52 aroma and 5 taste components in commercial not-from-concentrate grapefruit juices with flavor panel preference was determined. Methylene chloride extracts of juice were analyzed using GC/MS with a DB-5 column. Nonvolatiles determined included limonin and naringin by HPLC, degrees Brix, total acids, and degrees Brix/acid ratio. Juice samples were classified into low, medium, or high categories, based on average taste panel preference scores (nine-point hedonic scale). Principal component analysis demonstrated that highest quality juices were tightly clustered. Discriminant analysis indicated that 82% of the samples could be identified in the correct preference category using only myrcene, beta-caryophyllene, linalool, nootkatone, and degrees Brix. Nootkatone alone was not strongly associated with preference scores. The most preferred juices were strongly associated with low myrcene, low linalool, and intermediate levels of beta-caryophyllene. PMID:10554226

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

    NASA Astrophysics Data System (ADS)

    Liu, Yunping; Zheng, Ran; Han, Zhangang; Gong, Kaining; He, Xueli; Zhai, Xueliang

    2015-11-01

    Two supramolecular hybrids [Ni(mbpy)3]2[V2W4O19]·6H2O (1) and [Ni(mbpy)3]2[VW12O40] (2) (mbpy=4,4ʹ-dimethyl-2,2ʹ-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)3]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.

  16. High-Resolution Spectra and Analysis of the ν 8 Band of Methylene Chloride

    NASA Astrophysics Data System (ADS)

    Morone, A.; Snels, M.; Polanz, O.

    1995-09-01

    The infrared spectra of the ν 8 band of natural methylene chloride and isotopically pure CH 235Cl 2 have been recorded at a resolution of 0.0025 cm -1 in the range 1100-1400 cm -1 with a Bruker IFS 120 HR Fourier transform interferometer. The spectrum of the ν 8 fundamental band has been analyzed for the most abundant isotopic species CH 235Cl 2 and CH 235Cl 37Cl, as well as the ν 4 + ν 8 - ν 4 hot band of CH 235Cl 2. From a rotational analysis, excited state constants up to quartic terms have been obtained, using Watson's A-reduction Hamiltonian in the Ir representation. No perturbations have been observed. The standard deviations of the fits vary from 0.44 × 10 -3 to 0.62 × 10 -3 cm -1.

  17. Adsorptive removal of methylene blue by agar: effects of NaCl and ethanol

    PubMed Central

    2012-01-01

    Adsorption of methylene blue (MB) on agar was investigated as a function of temperature (308-328 K), different concentrations of NaCl and HCl and various weight percentages of binary mixtures of ethanol with water. It was observed that the maximum experimental adsorption capacity, qm, exp, in water is up to 50 mg g-1 and decreases with increase in weight percentage of ethanol and NaCl and HCl concentration compared to that of water. Analysis of data using ARIAN model showed that MB adsorbs as monomer and dimer on the surface of agar. Binding constants of MB to agar were calculated using the Temkin isotherm. The process is exothermic in water and other solutions. The mean adsorption energy (E) value indicated binding of MB to agar is chemical adsorption. Kinetics of this interaction obeys from the pseudo-second-order model and diffusion of the MB molecules into the agar is the main rate-controlling step. PMID:22339759

  18. Pseudopeptide-Based Hydrogels Trapping Methylene Blue and Eosin Y.

    PubMed

    Milli, Lorenzo; Zanna, Nicola; Merlettini, Andrea; Di Giosia, Matteo; Calvaresi, Matteo; Focarete, Maria Letizia; Tomasini, Claudia

    2016-08-16

    We present herein the preparation of four different hydrogels based on the pseudopeptide gelator Fmoc-l-Phe-d-Oxd-OH (Fmoc=fluorenylmethyloxycarbonyl), either by changing the gelator concentration or adding graphene oxide (GO) to the water solution. The hydrogels have been analysed by rheological studies that demonstrated that pure hydrogels are slightly stronger compared to GO-loaded hydrogels. Then the hydrogels efficiency to trap the cationic methylene blue (MB) and anionic eosin Y (EY) dyes has been analyzed. MB is efficiently trapped by both the pure hydrogel and the GO-loaded hydrogel through π-π interactions and electrostatic interactions. In contrast, the removal of the anionic EY is achieved in less satisfactory yields, due to the unfavourable electrostatic interactions between the dye, the gelator and GO. PMID:27417509

  19. Lifetime-based photoacoustic probe activation modeled by a dual methylene blue-lysine conjugate

    NASA Astrophysics Data System (ADS)

    Morgounova, Ekaterina; Johnson, Sadie M.; Shao, Qi; Hackel, Benjamin; Ashkenazi, Shai

    2014-03-01

    Activatable photoacoustic probes have a promising future due to their ability to provide high-resolution, high-penetration depth information on enzyme activity in vivo. Spectral identification methods, however, suffer from heterogeneous optical properties and wavelength-dependent light attenuation in tissue, thereby limiting the effective suppression of background noise signal. Our approach is predicated on probing the excited-state lifetime of a dual-labeled methylene blue (MB) probe that changes its lifetime from short to long upon cleavage. Recently, we have reported on the ability of our system to probe the long triplet lifetime of free MB monomers in solution and to differentiate between monomers and dimers based on their lifetime contrast. Here we introduce an improvement to our system that significantly increases the system sensitivity to fast changes, and reduces the minimum resolvable lifetime down to a few nanoseconds. We applied this method to probe the excited-state lifetime of a covalently coupled dual methylene blue-lysine conjugate (MB2K) in a mixed MB/MB2K solution. Preliminary results show that a stable dimeric bond is formed between the chromophores within the conjugate, and that this conjugate is statically quenched. Examination of the transient absorption of MB2K reveals it does not exhibit a triplet excited-state lifetime, suggesting that it undergoes a fast deexcitation process directly from the singlet state. Finally, we demonstrate how the transient photoacoustic lifetime signal can be used to selectively detect the presence of MB monomers while improving background noise suppression by differentiating the lifetime of free MB dye with other absorbing structures.

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

    PubMed

    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. PMID:27016719

  1. Diffusion of Methylene Blue in Phantoms of Agar Using a Photoacoustic Technique

    NASA Astrophysics Data System (ADS)

    Vilca-Quispe, L.; Alvarado-Gil, J. J.; Quintana, P.; Ordonez-Miranda, J.

    2010-05-01

    In this work, the kinetics of diffusion of methylene blue in agar aqueous solution is studied using a photoacoustic technique. Two agar phantoms solutions in water with a relation of mass/volume of 0.01% and 0.05% were analyzed. The study was performed using a modified Rosencwaig photoacoustic cell that is enclosed by transparent windows, on both sides. The sample is deposited directly on top of the upper window. A red light beam, at a fixed modulation frequency, is sent through the lower window illuminating the sample and inducing the photoacoustic effect inside the closed chamber of the cell. At the beginning of the experiment, a droplet of 100μL of agar solution is deposited; afterwards, the signal stabilizes, and 10μL of methylene blue aqueous solution (0.0125 g · mL-1) is added to the surface of the agar. During the first seconds of the experiment, the photoacoustic signal amplitude increases followed by a gradual and long decay. Results for modulation frequencies in the range from 10Hz to 80Hz for both agar concentrations are presented. A simple theoretical approach is presented to analyze the experimental data. It is demonstrated that the kinetics of the process can be parameterized as a function of the changes of an effective optical absorption coefficient. From these results, the characteristic time, in which the dye diffusion process stabilizes, is obtained. It is found that this time is larger for samples with a higher agar concentration. These differences provide important results for biomedical sciences in which agar gels are used as phantoms resembling some of the properties of living organs and tissues.

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

    PubMed

    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. PMID:16427273

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Perioperative Diagnosis and Treatment of Serotonin Syndrome Following Administration of Methylene Blue

    PubMed Central

    Francescangeli, James; Vaida, Sonia; Bonavia, Anthony S.

    2016-01-01

    Patient: Male, 67 Final Diagnosis: Serotonin syndrome Symptoms: Agitation • muscular spasticity, deficient muscular control • nystygmus • sweating • tachycardia Medication: Methylene Blue Clinical Procedure: Total abdominal colectomy Specialty: Anesthesiology Objective: Unusual clinical course Background: Serotonin syndrome (SS) involves serotonergic hyperactivity caused by excessive activation of 5-HT2A receptors. As the use of antidepressants increases, so does the population of patients at risk for developing this complication. The diagnosis is made based on current serotonergic medication use in conjunction with certain clinical signs. The severity of the clinical presentation may vary, especially when the complication occurs while the patient is under general anesthesia. As a result, the incidence of SS is likely underreported and treatment may be delayed, leading to life-threatening complications. Case Report: A 67-year-old, American Society of Anesthesiologist physical status 3 male with multiple medical comorbidities, including anxiety/depression and chronic neck pain, presented for an elective laparoscopic total abdominal colectomy for colonic inertia. His intraoperative course was significant for SS likely triggered by the administration of methylene blue, which only became clinically apparent during anesthetic emergence. We considered and systematically ruled out other potential causes of his clinical condition. His management was primarily supportive, using hydration and benzodiazepine administration, and resulted in full neurologic recovery. Conclusions: SS is an underdiagnosed condition with limited treatment options beyond symptom management. Thus, vigilance, early diagnosis, and cessation of offending medications are of utmost importance. Anesthesiologists managing at-risk surgical patients must have a high clinical suspicion of perioperative SS if their patients exhibit tachycardia, hypertension, and hyperthermia together with clonus

  5. Neighboring group catalysis in the design of nucleotide prodrugs.

    PubMed

    Khamnei, S; Torrence, P F

    1996-09-27

    An approach is described for potential application to the delivery of polar nucleosides and nucleotides across lipophilic membranes, namely, nucleotide prodrugs based on salicyl phosphate. 3'-Azido-3'-deoxythymidine (AZT) and 3'-deoxythymidine (ddT) were chosen as models. For the synthesis of prototype compounds 1 and 2, the approach was first to react either methyl salicylate (for 1) or phenyl salicylate (for 2) with phosphorus oxychloride in dry methylene chloride at 0 degree C with the addition of triethylamine as acid scavenger. The resulting intermediate phosphorodichloridate was reacted immediately with excess nucleoside under the same conditions. The control model compound 3 was prepared by reaction of phenyl phosphorodichloridate and excess nucleoside in pyridine/methylene chloride at 0 degree C to give 3 in 82% yield. The synthesis of triester 7 involved reaction of alpha-(chloroacetyl)salicyl chloride with 2,3,4,6-tetra-O-benzyl-D-glucopyranose to give [[(2,3,4,6-tetra-O-benzyl-D-glucopyranosyl)-oxy]carbonyl]-2- (1-chloroacetoxy)benzene (4) which was dechloroacetylated to 5,2,3,4,6-tetra-O-benzyl-D-glucopyranosyl salicylate. Phosphorylation of 5 with phosphorus oxychloride provided the phosphorodichloridate which was directly converted to 6 by reaction with dideoxythymidine. Removal of benzyl groups by catalytic hydrogenation gave compound 7, bis(2',3'-dideoxythymidin-5'-yl) D-glucopyranosyl phosphate. The AZT prodrug triesters, 1 and 2, underwent much more rapid hydrolysis than the triester 3, most probably due to the formation of an acyl phosphate complex from the attack on phosphorus of the salicylate carboxylate. The hydrolysis of the less lipophilic 7 was significantly slower than that of 1 or 2. Both pig liver esterase and rat brain cytosol were able to effect the cleavage to dinucleotide or mononucleotide of prodrug forms 2 and 7, much more rapidly than either 3 or 1, suggesting that the esterase-like enzymatic activity of rat brain was similar to

  6. Synthetic protocol toward fused pyrazolone derivatives via a Michael addition and reductive ring closing strategy.

    PubMed

    Parekh, Nikita; Thomas, Joice; John, Jubi; Kusurkar, Radhika; De Borggraeve, Wim M; Dehaen, Wim

    2014-06-01

    A new class of pyrazolo[3,4-c]pyridine-3,7-dione and pyrazolo[3,4-d]azepine-3,7-dione scaffolds was synthesized via a Michael addition and reductive cyclization strategy. These fused heterocycles were accessed from simple starting materials such as nitroolefins and 3-ethoxycarbonyl(methylene)pyrazoline-5-one. The pyrazolo-fused heterocycles were obtained in good overall yields. PMID:24797239

  7. Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric α-Cr2O3(0001)

    SciTech Connect

    Dong, Yujung; Brooks, John D.; Chen, Tsung-Liang; Mullins, David R.; Cox, David F.

    2015-06-10

    The reaction of iodomethane on the nearly stoichiometric α-Cr2O3(0001) surface produces gas phase ethylene, methane, and surface iodine adatoms. The reaction is first initiated by the dissociation of iodomethane into surface methyl fragments, -CH3, and iodine adatoms. Methyl fragments bound at surface Cr cation sites undergo a rate-limiting dehydrogenation reaction to methylene, =CH2. The methylene intermediates formed from methyl dehydrogenation can then undergo coupling reactions to produce ethylene via two principle reaction pathways: (1) direct coupling of methylene and (2) methylene insertion into the methyl surface bond to form surface ethyl groups which undergo β-H elimination to produce ethylene. The liberated hydrogen also combines with methyl groups to form methane. Iodine adatoms from the dissociation of iodomethane deactivate the surface by simple site blocking of the surface Cr3+ cations.

  8. MIR and NIR group spectra of n-alkanes and 1-chloroalkanes

    NASA Astrophysics Data System (ADS)

    Kwaśniewicz, Michał; Czarnecki, Mirosław A.

    2015-05-01

    Numerous attempts were undertaken to resolve the absorption originating from different parts of alkanes. The separation of the contributions from the terminal and midchain methylene units was observed only in the spectra of solid alkanes at low temperatures. On the other hand, for liquid alkanes this effect was not reported as yet. In this study, ATR-IR, Raman and NIR spectra of eight n-alkanes and seven 1-chloroalkanes in the liquid phase were measured from 1000 to 12,000 cm-1. The spectra were analyzed by using two-dimensional (2D) correlation approach and chemometrics methods. It was shown that in 2D asynchronous contour plots, constructed from the spectra of n-alkanes and 1-chloroalkanes, the methylene band was resolved into two components. These two components were assigned to the terminal and midchain methylene groups. For the first time, the contributions from these two molecular fragments were resolved in the spectra of liquid n-alkanes and 1-chloroalkanes. MCR-ALS resolved these spectra into two components that were assigned to the ethyl and midchain methylene groups. These components represent the group spectra that can be used for assignment, spectral analysis and prediction of unknown spectra. The spectral prediction based on the group spectra provides very good results for n-alkanes, especially in the first and second overtone regions.

  9. Analysis of transition state stabilization by non-covalent interactions in the Houk-List model of organocatalyzed intermolecular Aldol additions using functional-group symmetry-adapted perturbation theory.

    PubMed

    Bakr, Brandon W; Sherrill, C David

    2016-04-21

    Rational design of catalysts would be aided by a better understanding of how non-covalent interactions stabilize transition states. Here, we apply the newly-developed Functional-Group Symmetry-Adapted Perturbation Theory (F-SAPT) to quantify non-covalent interactions in transition states of the proline-catalyzed intermolecular aldol reaction between benzaldehyde and cyclohexanone, according to the Houk-List mechanism [Bahmanyar et al., J. Am. Chem. Soc., 2003, 125, 2475]. A recent re-examination of this organocatalytic reaction by Rzepa and co-workers [Armstrong et al., Chem. Sci., 2014, 5, 2057] used electron density analysis to identify three key non-covalent interactions thought to influence stereoselectivity: (1) a favorable electrostatic interaction (originally identified by Houk and List) between the NCH(δ+) group of the enamine intermediate and the (δ-)O[double bond, length as m-dash]C of benzaldehyde; (2) a C-H/π interaction between the cyclohexene group of the enamine intermediate and the benzaldehyde phenyl ring; (3) a stabilizing contact between an ortho-hydrogen of the phenyl and an oxygen of the carboxylic acid group of the enamine. These three interactions have been directly computed using F-SAPT, which confirms the stabilizing interaction between an ortho-hydrogen and the carboxylic acid in the (S,S) and (R,S) transition state stereoisomers. F-SAPT analysis also finds stabilizing dispersion and electrostatic interactions due to a C-H/π interaction between the cyclohexene and phenyl groups in the (S,S) and (R,R) transition states. However, unfavorable exchange-repulsion cancels the attractive terms that favor these stereoisomers. Surprisingly, the interaction thought to be most important for stereoselectivity, the NCH(δ+)(δ-)O[double bond, length as m-dash]C interaction, is actually found to be repulsive due to the negative charge on the nitrogen. Hence, our results indicate that geometric analysis and/or density-based analysis does not

  10. Further karyosystematic studies of the Boreonectes griseostriatus (De Geer) group of sibling species (Coleoptera, Dytiscidae)–characterisation of B. emmerichi (Falkenström, 1936) and additional European data

    PubMed Central

    Angus, Robert B.; Angus, Elizabeth M.; Jia, Fenglong; Chen, Zhen-ning; Zhang, Ying

    2015-01-01

    Abstract A lectotype is designated for the Tibetan species Deronectes emmerichi Falkenström, 1936 (Currently Boreonectes emmerichi (Falkenström)), and its habitus, as well as the median lobe and parameres of its aedeagus, are figured along with additional comparative material. Material of Boreonectes emmerichi from Sikkim (BMNH) represents the first record of a Boreonectes Angus, 2010 species from India. The karyotype of Boreonectes emmerichi is described as having 26 pairs of autosomes plus sex chromosomes which are X0 (♂), XX (♀). The karyotype is most like that of Boreonectes macedonicus (Géuorguiev, 1959), but with slight differences. Additional chromosomal information is given for Boreonectes griseostriatus griseostriatus (De Geer, 1774) in the French Alps, Boreonectes griseostriatus strandi (Brinck, 1943) on the Kola Peninsula, Boreonectes multilineatus (Falkenström, 1922) in the Pyrenees and Boreonectes ibericus (Dutton & Angus, 2007) in the Spanish Picos de Europa. PMID:25893080

  11. Further karyosystematic studies of the Boreonectesgriseostriatus (De Geer) group of sibling species (Coleoptera, Dytiscidae)-characterisation of B.emmerichi (Falkenström, 1936) and additional European data.

    PubMed

    Angus, Robert B; Angus, Elizabeth M; Jia, Fenglong; Chen, Zhen-Ning; Zhang, Ying

    2015-01-01

    A lectotype is designated for the Tibetan species Deronectesemmerichi Falkenström, 1936 (Currently Boreonectesemmerichi (Falkenström)), and its habitus, as well as the median lobe and parameres of its aedeagus, are figured along with additional comparative material. Material of Boreonectesemmerichi from Sikkim (BMNH) represents the first record of a Boreonectes Angus, 2010 species from India. The karyotype of Boreonectesemmerichi is described as having 26 pairs of autosomes plus sex chromosomes which are X0 (♂), XX (♀). The karyotype is most like that of Boreonectesmacedonicus (Géuorguiev, 1959), but with slight differences. Additional chromosomal information is given for Boreonectesgriseostriatusgriseostriatus (De Geer, 1774) in the French Alps, Boreonectesgriseostriatusstrandi (Brinck, 1943) on the Kola Peninsula, Boreonectesmultilineatus (Falkenström, 1922) in the Pyrenees and Boreonectesibericus (Dutton & Angus, 2007) in the Spanish Picos de Europa. PMID:25893080

  12. 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

    PubMed Central

    Jin, Kwang Nam; 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, P<0.001). MLM showed superior staining ability over methylene 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. PMID:24431917

  13. Assertive Training in Groups

    ERIC Educational Resources Information Center

    Sansbury, David L.

    1974-01-01

    This article describes a group approach to helping the nonassertive client. After describing the group composition and goals, he presents a session by session description for conducting the assertive training group. In addition, he presents suggestions based on experiences in leading the group. (Author)

  14. A simplified post preparation technique after Thermafil obturation: evaluation of apical microleakage and presence of voids using methylene blue dye penetration

    PubMed Central

    Pusinanti, Luca; Rubini, Riccardo; Pellati, Agnese; Zerman, Nicoletta

    2013-01-01

    Summary Aim To evaluate the apical microleakage of Thermafil obturations after three different post space preparation techniques. Materials and methods 33 root canals of mono-radiculated extracted teeth were prepared with M two and then obturated with Thermafil. Teeth so treated were then divided into three groups and the post space to middle root was prepared using three different techniques. In samples in group A the housing for the post was created using a Torpan bur, and the carrier was partially removed only in the coronal portion. In samples in group B the carrier was completely removed and gutta-percha was hand compacted, before canal preparation using a Torpan bur. In samples in group C the carrier was completely removed, without guttapercha compaction, before canal preparation using a Torpan bur. The roots were immersed for 72 hours in methylene blue dye solution and sectioned transversely at 1-3-5 mm from the apex for evaluation of dye penetration using a stereomicroscope. The data collected were processed using Win CAD software and subjected to statistical analysis using the Student t test for p<0.05. Results There were no significant differences between the three groups, except for the presence of voids in the intermediate section of teeth in groups B and C. Conclusions Post space preparation did not influence the apical seal, and gutta-percha without voids was always found in the last millimetre of the canal obturation. This study proposes a post preparation technique which provides for complete carrier removal using pliers, hand compaction of residual gutta-percha with a manual plugger and enlargement of the root canal, using appropriate post space burs, free of any interference from the carrier. Operating time is reduced, as is the risk of creating ledges or iatrogenic perforations. PMID:23991269

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

    SciTech Connect

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

    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.

  16. Economic analysis of a phase III clinical trial evaluating the addition of total androgen suppression to radiation versus radiation alone for locally advanced prostate cancer (Radiation Therapy Oncology Group protocol 86-10)

    SciTech Connect

    Konski, Andre . E-mail: a_konski@fccc.edu; Sherman, Eric; Krahn, Murray; Bremner, Karen; Beck, J. Robert; Watkins-Bruner, Deborah; Pilepich, Michael

    2005-11-01

    Purpose: To evaluate the cost-effectiveness of adding hormone therapy to radiation for patients with locally advanced prostate cancer, using a Monte Carlo simulation of a Markov Model. Methods and Materials: Radiation Therapy Oncology Group (RTOG) protocol 86-10 randomized patients to receive radiation therapy (RT) alone or RT plus total androgen suppression (RTHormones) 2 months before and during RT for the treatment of locally advanced prostate cancer. A Markov model was designed with Data Pro (TreeAge Software, Williamstown, MA). The analysis took a payer's perspective. Transition probabilities from one state of health (i.e., with no disease progression or with hormone-responsive metastatic disease) to another were calculated from published rates pertaining to RTOG 86-10. Patients remained in one state of health for 1 year. Utility values for each health state and treatment were obtained from the literature. Distributions were sampled at random from the treatment utilities according to a second-order Monte Carlo simulation technique. Results: The mean expected cost for the RT-only treatments was $29,240 (range, $29,138-$29,403). The mean effectiveness for the RT-only treatment was 5.48 quality-adjusted life years (QALYs) (range, 5.47-5.50). The mean expected cost for RTHormones was $31,286 (range, $31,058-$31,555). The mean effectiveness was 6.43 QALYs (range, 6.42-6.44). Incremental cost-effectiveness analysis showed RTHormones to be within the range of cost-effectiveness at $2,153/QALY. Cost-effectiveness acceptability curve analysis resulted in a >80% probability that RTHormones is cost-effective. Conclusions: Our analysis shows that adding hormonal treatment to RT improves health outcomes at a cost that is within the acceptable cost-effectiveness range.

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

    PubMed Central

    Martinez, Juan Carlos; Thomas, Jamie L.; Lukaszczyk, John J.

    2014-01-01

    INTRODUCTION Traditionally, localization of small intestine sources of obscure gastrointestinal bleeding has been a challenge. Advances in the field of endoscopy with the introduction of capsule endoscopy and radiographic imaging with computed tomography angiography and visceral angiography have facilitated more accurate visualization of the small intestine. If a bleeding lesion is identified on angiography and surgery is indicated, the use of methylene blue for enteric mapping is very effective to aid intraoperative localization of the culprit. However, when this is not an option, more invasive surgical techniques are required. 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. PMID:25460480

  18. Compounds extracted from feverfew that have anti-secretory activity contain an alpha-methylene butyrolactone unit.

    PubMed

    Groenewegen, W A; Knight, D W; Heptinstall, S

    1986-09-01

    Extracts of feverfew inhibit secretion of granular contents from platelets and neutrophils and this may be relevant to the therapeutic value of feverfew in migraine and other conditions. In this investigation we fractionated an extract of feverfew and obtained eleven fractions with antisecretory activity. The activity. The active fractions, together with two fractions that were devoid of anti-secretory activity, were examined using 1H NMR and infrared spectroscopy. All the active fractions (but neither of the inactive fractions) contained compounds with an alpha-methylene butyrolactone unit. Five compounds that contain this unit were identified as parthenolide, 3-beta-hydroxyparthenolide, secotanapartholide A, canin and artecanin, all of which are sesquiterpene lactones. It is very likely that these and other sesquiterpene lactones that contain an alpha-methylene butyrolactone unit are responsible for the anti-secretory activity in extracts of feverfew. PMID:2877077

  19. A polychromatic staining method for epoxy embedded tissue: a new combination of methylene blue and basic fuchsine for light microscopy.

    PubMed

    D'Amico, F

    2005-01-01

    A simple and rapid method is described for staining semithin sections of material embedded in epoxy resin for observing tissues prior to transmission electron microscopy. The method is suitable for tissue fixed with a glutaraldehyde-formaldehyde mixture and postfixed in osmium tetroxide. No etching or oxidizing procedures are necessary. Sections 0.5-0.8 microm thick are dried onto a slide and stained with either 0.75% methylene blue and 0.25% azure B or 0.5% methylene blue and 0.5% azure II in 0.5% aqueous borax and heated over a flame for 8-10 sec. The slides are rinsed with water, then stained the same way with 0.1% basic fuchsine in 5% aqueous ethanol. Cytoplasm stains blue; nuclei darker blue; collagen, mucus and elastin pink to red; fat and intracellular lipid droplets gray-green. PMID:16720521

  20. Tubular structured hierarchical mesoporous titania material derived from natural cellulosic substances and application as photocatalyst for degradation of methylene blue

    SciTech Connect

    Huang, Haiqing; Liu, Xiaoyan; Huang, Jianguo

    2011-11-15

    Graphical abstract: Bio-inspired, tubular structured hierarchical mesoporous titania material with high photocatalytic activity under UV light was fabricated employing natural cellulosic substance (cotton) as hard template and cetyltrimethylammonium bromide (CTAB) surfactant as soft template using a one-pot sol-gel method. Highlights: {yields} Tubular structured mesoporous titania material was fabricated by sol-gel method. {yields} The titania material faithfully recorded the hierarchical structure of the template substrate (cotton). {yields} The titania material exhibited high photocatalytic activity in decomposition of methylene blue. -- Abstract: Bio-inspired, tubular structured hierarchical mesoporous titania material was designed and fabricated employing natural cellulosic substance (cotton) as hard template and cetyltrimethylammonium bromide (CTAB) surfactant as soft template by one-pot sol-gel method. The tubular structured hierarchical mesoporous titania material processes large specific surface area (40.23 m{sup 2}/g) and shows high photocatalytic activity in the photodegradation of methylene blue under UV light irradiation.

  1. Effects of the aqueous and methylene chloride extracts of Bidens pilosa leaf on fructose-hypertensive rats.

    PubMed

    Dimo, T; Azay, J; Tan, P V; Pellecuer, J; Cros, G; Bopelet, M; Serrano, J J

    2001-08-01

    We investigated the effects of the aqueous (150-350 mg/kg) and methylene chloride (150-300 mg/kg) extracts of Bidens pilosa on fructose-induced hypertension in rats. Food and liquid intake were measured as well as systolic blood pressure and plasma levels of glucose, insulin, cholesterol, triglycerides and creatinine. Fructose feeding for 6 weeks induced hypertension, hyperinsulinemia and increased plasma triglyceride levels in male Wistar rats. The aqueous and methylene chloride extracts of B. pilosa reversed the high blood pressure and hypertriglyceridemia developed due to fructose feeding but did not have any effects on plasma levels of insulin and glucose. High doses of the extracts reduced plasma creatinine levels and tended to increase plasma cholesterol. These results suggest that the extracts of B. pilosa possess hypotensive effects whose mechanism of action is not related to insulin sensitivity. PMID:11448541

  2. Use of methylene blue as a simulant for the physical properties of cocaine HCl and heroin HCl

    NASA Astrophysics Data System (ADS)

    Patrick, Julie C.; Orzechowska, Grazyna E.; Poziomek, Edward J.

    1997-02-01

    Technological challenges in the development and testing of illicit narcotics include assuring safety of researchers and operations personnel from drug exposure, assessing the efficiency of sampling and sample handling, checking for artifacts introduced by field procedures, and maintaining quality control/quality assurance. The dye methylene blue was chosen as a simulant for cocaine HCl and heroin HCl. The similarities include the presence of fused ring systems, molecular weights over 300 g/mol, and melting points between 200 and 300 degrees C. A significant difference is that methylene blue has a much lower solubility in water than cocaine HCl and heroin HCl. Experiments have been conducted to successfully increase the solubility of the simulant to match those of cocaine HCl and heroin HCl by adding solidum methyl sulfate.

  3. Novelties of combustion synthesized titania ultrafiltration membrane in efficient removal of methylene blue dye from aqueous effluent.

    PubMed

    Doke, Suresh M; Yadav, Ganapati D

    2014-12-01

    In this study, titania nanoparticles were synthesized by combustion and used to make ultrafiltration membrane. Characteristics of titania membranes such as textural evaluation, surface morphology, pure water permeability and protein rejection were investigated. Titania membrane sintered at 450 °C showed pure water permeability 11 × 10−2 L h−1 m−2 kPa−1 and 76% protein rejection. The membrane presented good water flux and retention properties with regards to protein and methylene blue dye. Ultrafiltration process was operated at lower pressure (100 kPa) and showed 99% removal of methylene blue using adsorptive micellar flocculation at sodium dodecyl sulfate concentration below its critical micellar concentration. Ferric chloride was used as the coagulant. The method of making titania membrane and its use are new. These studies can be extended to other dyes and pollutants. PMID:25461945

  4. One-pot preparation of superparamagnetic attapulgite/Fe3O4/polydopamine nanocomposites for adsorption of methylene blue

    NASA Astrophysics Data System (ADS)

    Mu, Bin; Kang, Yuru; Zheng, Maosong; Wang, Aiqin

    2016-05-01

    Superparamagnetic attapulgite/Fe3O4/polydopamine nanocomposites have been facilely prepared by a one-pot process without the nitrogen protection, in which Fe(III) was served as both of the oxidant for dopamine and the precursor of Fe3O4 in the presence of attapulgite. The introduction of attapulgite can effectively induce the uniform encapsulation of polydopamine and Fe3O4 nanoparticles on the surface of attapulgite, preventing from the formation of the free aggregates of Fe3O4 nanoparticles. The as-prepared APT/Fe3O4/PANI nanocomposites can be used as an adsorbent for the removal of methylene blue, and the adsorption ratio toward 100 ppm of methylene blue could reach 95.8%.

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

    NASA Astrophysics Data System (ADS)

    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.

  6. Evaluation of the protein biomarkers and the analgesic response to systemic methylene blue in patients with refractory neuropathic pain: a double-blind, controlled study

    PubMed Central

    Miclescu, Adriana A; Svahn, Martin; Gordh, Torsten E

    2015-01-01

    Aim This study was carried out in patients with neuropathic pain in order to assess the analgesic effects and changes in protein biomarkers after the administration of methylene blue (MB), a diaminophenothiazine with antioxidant and anti-inflammatory properties, and with inhibitory effects on nitric oxide. Materials and methods Ten patients with chronic refractory neuropathic pain were randomized to receive either MB (10 mg/mL Methylthioninium chloride) 2 mg/kg (MB group) or MB 0.02 mg/kg (control group) infused over 60 minutes. Sensory function and pain (Numerical Rating Scale) were evaluated at baseline and at 60 minutes after the start of the infusion. The patients kept a pain diary during the next 24 hours and for the following 4 days. Plasma and urinary concentrations of 8-isoprostane-prostaglandin F2α (8-iso-PGF2α) and plasma protein biomarkers prior to and after the infusions were measured with radioimmunoassay and with proximity extension assay. Results A decrease of the Numerical Rating Scale at 60 minutes in comparison with baseline was observed in the MB (P=0.047) group. The decrease was significant between the MB and the control group on the day of and day after MB infusion (P=0.04 and P=0.008, respectively). There was no difference in systemic protein expressions between groups except for prolactin (PRL) (P=0.02). Three patients demonstrated diminished dynamic mechanical allodynia. Conclusion MB decreased the pain levels in patients with chronic therapy-resistant neuropathic pain on the first 2 days after administration. Known as an endocrine modulator on the anterior pituitary gland, MB infusion produced a decrease of PRL. The detailed role of PRL effects in chronic neuropathic pain remains undetermined. PMID:26213475

  7. Synthesis of Isoxazoline/Cyclic Nitrone-Featured Methylenes Using Unsaturated Ketoximes: A Dual Role of TEMPO.

    PubMed

    Chen, Fei; Yang, Xiu-Long; Wu, Zhi-Wei; Han, Bing

    2016-04-01

    A novel, metal-free, and regioselective approach for the synthesis of isoxazoline/cyclic nitrone-featured methylenes has been developed by the reaction of readily accessible β,γ- and γ,δ-unsaturated ketoximes with TEMPO via tandem iminoxyl radical-promoted cyclization/TEMPO-mediated Cope-like elimination, respectively. This protocol utilizes commercially available TEMPO as the iminoxyl radical initiator as well as the β-hydrogen acceptor in the Cope-like elimination. PMID:26954339

  8. A new suprasterol by photochemical reaction of 1α,25-dihydroxy-9-methylene-19-norvitamin D3.

    PubMed

    Kulesza, Urszula; Plum, Lori A; DeLuca, Hector F; Mouriño, Antonio; Sicinski, Rafal R

    2016-02-01

    The UV-induced photochemical reaction of 1α,25-dihydroxy-9-methylene-19-norvitamin D3 has been investigated. The pentacyclic structure of the isolated product has been unequivocally established by X-ray crystallographic analysis. The possible reaction paths of the examined photochemical transformation are discussed. Biological in vivo and in vitro tests proved that the photoproduct is devoid of calcemic activity. PMID:26693597

  9. Removal of Congo Red and Methylene Blue from Aqueous Solutions by Vermicompost-Derived Biochars.

    PubMed

    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. PMID:27144922

  10. Enzymatic hydroxylation of an unactivated methylene C-H bond guided by molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Narayan, Alison R. H.; Jiménez-Osés, Gonzalo; Liu, Peng; Negretti, Solymar; Zhao, Wanxiang; Gilbert, Michael M.; Ramabhadran, Raghunath O.; Yang, Yun-Fang; Furan, Lawrence R.; Li, Zhe; Podust, Larissa M.; Montgomery, John; Houk, K. N.; Sherman, David H.

    2015-08-01

    The hallmark of enzymes from secondary metabolic pathways is the pairing of powerful reactivity with exquisite site selectivity. The application of these biocatalytic tools in organic synthesis, however, remains under-utilized due to limitations in substrate scope and scalability. Here, we report how the reactivity of a monooxygenase (PikC) from the pikromycin pathway is modified through computationally guided protein and substrate engineering, and applied to the oxidation of unactivated methylene C-H bonds. Molecular dynamics and quantum mechanical calculations were used to develop a predictive model for substrate scope, site selectivity and stereoselectivity of PikC-mediated C-H oxidation. A suite of menthol derivatives was screened computationally and evaluated through in vitro reactions, where each substrate adhered to the predicted models for selectivity and conversion to product. This platform was also expanded beyond menthol-based substrates to the selective hydroxylation of a variety of substrate cores ranging from cyclic to fused bicyclic and bridged bicyclic compounds.

  11. Adsorption of Methylene Blue from Aqueous Solutions by Polyvinyl Alcohol/Graphene Oxide Composites.

    PubMed

    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. PMID:27433669

  12. Photocatalytic degradation of methylene blue under UV light irradiation on prepared carbonaceous TiO2.

    PubMed

    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. PMID:25013855

  13. Biosorption of methylene blue from aqueous solutions by a waste biomaterial: hen feathers

    NASA Astrophysics Data System (ADS)

    Chowdhury, Shamik; Saha, Papita Das

    2012-09-01

    Biosorption potential of hen feathers (HFs) to remove methylene blue (MB) from aqueous solutions was investigated. Batch experiments were carried out as function of different process parameters such as pH, initial dye concentration, biosorbent dose and temperature. The optimum conditions for removal of MB were found to be pH 7.0, biosorbent dose = 1.0 g, and initial dye concentration = 50 mg L-1. The temperature had a strong influence on the biosorption process. Experimental biosorption data were modeled by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms with the Langmuir isotherm showing the best fit at all temperatures studied. The maximum monolayer sorption capacity was determined as 134.76 mg g-1 at 303 K. According to the mean free energy values of sorption ( E) calculated using the D-R isotherm model, biosorption of MB onto HFs was chemisorption. Kinetic studies showed that the biosorption of MB followed pseudo second-order kinetics. The activation energy ( E a) determined using the Arrhenius equation confirmed that the biosorption involved chemical ion-exchange. Thermodynamic studies showed that the biosorption process was spontaneous and exothermic. To conclude, HFs is a promising biosorbent for MB removal from aqueous solutions.

  14. Real-Time Near-Infrared Fluorescence-Guided Identification of the Ureters using Methylene Blue

    PubMed Central

    Matsui, Aya; Tanaka, Eiichi; Choi, Hak Soo; Kianzad, Vida; Gioux, Sylvain; Lomnes, Stephen J.; Frangioni, John V.

    2009-01-01

    Background The aim of this study was to determine whether the invisible near-infrared (NIR) fluorescence properties of methylene blue (MB), a dye already FDA-approved for other indications, could be exploited for real-time, intraoperative identification of the ureters. Methods The optical properties of MB were quantified in vitro. Open surgery and laparoscopic NIR fluorescence imaging systems were employed. Yorkshire pigs were injected intravenously with: 0.1 mg/kg MB (n = 8), 10 mg furosemide followed by 0.1 mg/kg MB (n = 6), or 0.5 mg/kg MB (n = 6). The contrast-to-background ratio (CBR) of the kidney and ureters, and MB concentration in urine, were quantified. Results Peak MB absorbance, emission, and intensity in urine occurred at 668 nm, 688 nm, and 20 μM, respectively. After intravenous injection, doses as low as 0.1 mg/kg MB provided prolonged imaging of the ureters, and a dose of 0.5 mg/kg provided statistically significant improvement of CBR. Pre-injection of furosemide increased urine volume but did not improve CBR. Laparoscopic identification of the ureter using MB NIR fluorescence was demonstrated. Conclusions Ureteral imaging using MB NIR fluorescence provides sensitive, real-time, intraoperative identification of the ureters during open and laparoscopic surgeries. PMID:20117811

  15. Vibrational studies on (E)-1-((pyridine-2-yl)methylene)semicarbazide using experimental and theoretical method

    NASA Astrophysics Data System (ADS)

    Subashchandrabose, S.; Ramesh Babu, N.; Saleem, H.; Syed Ali Padusha, M.

    2015-08-01

    The (E)-1-((pyridine-2-yl)methylene)semicarbazide (PMSC) was synthesized. The experimental and theoretical study on molecular structure and vibrational spectra were carried out. The FT-IR (400-4000 cm-1), FT-Raman (50-3500 cm-1) and UV-Vis (200-500 nm) spectra of PMSC were recorded. The geometric structure, conformational analysis, vibrational wavenumbers of PMSC in the ground state have been calculated using B3LYP method of 6-311++G(d,p) basis set. The complete vibrational assignments were made on the basis of TED, calculated by SQM method. The Non-linear optical activity was measured by means of first order hyperpolarizability calculation and π-electrons of conjugative bond in the molecule. The intra-molecular charge transfer, mode hyperconjugative interaction and molecular stabilization energies were calculated. The band gap energies between occupied and unoccupied molecular orbitals were analyzed; it proposes lesser band gap with more reactivity. To understand the electronic properties of this molecule the Mulliken charges were also calculated.

  16. Sorption of methylene blue on treated agricultural adsorbents: equilibrium and kinetic studies

    NASA Astrophysics Data System (ADS)

    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.

  17. Comparative evaluation of methylene blue and demeclocycline for enhancing optical contrast of gliomas in optical images

    NASA Astrophysics Data System (ADS)

    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.

  18. Photocatalytic Degradation of Methylene Blue under UV Light Irradiation on Prepared Carbonaceous TiO2

    PubMed Central

    Che Ramli, Zatil Amali; 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 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. PMID:25013855

  19. Enzymatic Hydroxylation of an Unactivated Methylene C–H Bond Guided by Molecular Dynamics Simulations

    PubMed Central

    Narayan, Alison R. H.; Jiménez-Osés, Gonzalo; Liu, Peng; Negretti, Solymar; Zhao, Wanxiang; Gilbert, Michael M.; Ramabhadran, Raghunath O.; Yang, Yun-Fang; Furan, Lawrence R.; Li, Zhe; Podust, Larissa M.; Montgomery, John; Houk, K. N.; Sherman, David H.

    2015-01-01

    The hallmark of enzymes from secondary metabolic pathways is the pairing of powerful reactivity with exquisite site selectivity. The application of these biocatalytic tools in organic synthesis, however, remains under-utilized due to limitations in substrate scope and scalability. Here we report the reactivity of a monooxygenase (PikC) from the pikromycin pathway is modified through computationally-guided protein and substrate engineering, and applied to the oxidation of unactivated methylene C-H bonds. Molecular dynamics and quantum mechanical calculations were employed to develop a predictive model for substrate scope, site selectivity, and stereoselectivity of PikC mediated C-H oxidation. A suite of menthol derivatives was screened computationally and evaluated through in vitro reactions where each substrate adhered to the predicted models for selectivity and conversion to product. This platform was also expanded beyond menthol-based substrates to the selective hydroxylation of a variety of substrate cores ranging from cyclic to fused bicyclic and bridged bicyclic compounds. PMID:26201742

  20. Removal of methylene blue from aqueous solution by wood millet carbon optimization using response surface methodology

    NASA Astrophysics Data System (ADS)

    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).

  1. Adsorption of Methylene Blue, Bromophenol Blue, and Coomassie Brilliant Blue by α-chitin nanoparticles.

    PubMed

    Dhananasekaran, Solairaj; Palanivel, Rameshthangam; Pappu, Srinivasan

    2016-01-01

    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 (R (2) 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 (R (2) 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. PMID:26843977

  2. Methylene blue reduces Aβ levels and rescues early cognitive deficit by increasing proteasome activity

    PubMed Central

    Medina, David X.; Caccamo, Antonella; Oddo, Salvatore

    2010-01-01

    Promising results have emerged from a phase II clinical trial testing Methylene blue (MB) as a potential therapeutic for Alzheimer disease (AD), where improvements in cognitive functions of AD patients after 6 months of MB administration have been reported. Despite these reports, no preclinical testing of MB in mammals has been published, and thus its mechanism of action in relation to AD pathology remains unknown. In order to elucidate the effects of MB on AD pathology and to determine its mechanism of action, we used a mouse model (3xTg-AD) that develops age-dependent accumulation of Aβ and tau and cognitive decline. Here, we report that chronic dietary MB treatment reduces Aβ levels and improves learning and memory deficits in the 3xTg-AD mice. The mechanisms underlying the effects of MB on Aβ pathology appears to be mediated by an increase in Aβ clearance as we show that MB increases the chymotrypsin-and trypsin-like activities of the proteasome in the brain. To our knowledge, this is the first report showing that MB increases proteasome function and ameliorates AD-like pathology in vivo. Overall, the data presented here support the use of MB for the treatment of AD and offer a possible mechanism of action. PMID:20731659

  3. Sugarcane bagasse for the removal of erythrosin B and methylene blue from aqueous waste

    NASA Astrophysics Data System (ADS)

    Sharma, Pankaj; Kaur, Harleen

    2011-12-01

    Present study explores the potentiality of locally available cellulose, hemicellulose and lignin-rich agricultural by-product sugarcane bagasse (SB) for the removal of erythrosin B (EB) and methylene blue (MB) from aqueous waste. The SB has been characterized by Fourier transform infrared and scanning electron microscopy analytical techniques. Batch experiments have been carried out to determine the influence of parameters like initial dye concentration, pH of the medium, contact time between the adsorbate and adsorbent, weight of adsorbent and system temperature on the removal of EB and MB. Optimum conditions for adsorption are found to be pH 9, temperature 308 K and an equilibration time of 1 h. Under these conditions equilibrium isotherms have been analysed by Langmuir and Freundlich isotherm equations. Based on the Langmuir adsorption isotherm model, the predicted maximum monolayer adsorption capacities of SB for EB and MB are found to be 500 mg g-1 (at 328 K) and 1,000 mg g-1 (at 308 K), respectively. The separation factor reveals the favourable nature of the isotherm for the studied dyes—SB system. The thermodynamic study indicates that the adsorptions of dyes are spontaneous and endothermic process. High temperatures favour EB adsorption whereas optimum temperature for MB adsorption is 318 K.

  4. Adsorption of Methylene Blue, Bromophenol Blue, and Coomassie Brilliant Blue by α-chitin nanoparticles

    PubMed Central

    Dhananasekaran, Solairaj; Palanivel, Rameshthangam; Pappu, Srinivasan

    2015-01-01

    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. PMID:26843977

  5. Photodynamic inactivation of methylene blue and tungsten-halogen lamp light against food pathogen Listeria monocytogenes.

    PubMed

    Lin, Shao-ling; Hu, Jia-miao; Tang, Shu-shu; Wu, Xi-yang; Chen, Zhen-qiang; Tang, Shu-ze

    2012-01-01

    The aim of this study was to verify the bactericidal effect and the damage of photodynamic inactivation (PDI) using methylene blue (MB) and tungsten-halogen lamp over Listeria monocytogenes via atomic force microscopy, absorption spectrophotometry, agarose gel electrophoresis, real-time PCR and SDS-PAGE. The obtained data indicated that the viability of L. monocytogenes was ca 7-log reduced by illumination with 10 min tungsten-halogen lamp light under the presence of 0.5 μg mL(-1) MB, and this bactericidal activity against L. monocytogenes of PDI increased proportionally to the concentration of MB and the duration of irradiation. Moreover, after irradiation with MB and visible light, the leakage of intracellular contents was estimated by spectrophotometer at OD(260) and OD(280), which correlated with morphological alterations. Furthermore, genomic DNA cleavage and protein degradation were also detected after PDI treatment. Consequently, breakage of the membrane, damage of the genomic DNA and degradation of bacterial proteins may play an important role in the mechanisms involved in PDI-MB bactericidal activity on L. monocytogenes. PMID:22469298

  6. Adsorption of methylene blue and Congo red from aqueous solution by activated carbon and carbon nanotubes.

    PubMed

    Szlachta, M; Wójtowicz, P

    2013-01-01

    This study was conducted to determine the adsorption removal of dyes by powdered activated carbon (PAC, Norit) and multi-walled carbon nanotubes (MWCNTs, Chinese Academy of Science) from an aqueous solution. Methylene blue (MB) and Congo red (CR) were selected as model compounds. The adsorbents tested have a high surface area (PAC 835 m(2)/g, MWCNTs 358 m(2)/g) and a well-developed porous structure which enabled the effective treatment of dye-contaminated waters and wastewaters. To evaluate the capacity of PAC and MWCNTs to adsorb dyes, a series of batch adsorption experiments was performed. Both adsorbents exhibited a high adsorptive capacity for MB and CR, and equilibrium data fitted well with the Langmuir model, with the maximum adsorption capacity up to 400 mg/g for MB and 500 mg/g for CR. The separation factor, RL, revealed the favorable nature of the adsorption process under experimental conditions. The kinetics of adsorption was studied at various initial dye concentrations and solution temperatures. The pseudo-second-order model was used for determining the adsorption kinetics of MB and CR. The data obtained show that adsorption of both dyes was rapid in the initial stage and followed by slower processing to reach the plateau. The uptake of dyes increased with contact time, irrespective of their initial concentration and solution temperature. However, changes in the solution temperature did not significantly influence dye removal. PMID:24292474

  7. Methylene blue biosorption by pericarp of corn, alfalfa, and agave bagasse wastes.

    PubMed

    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. PMID:24701903

  8. Removal of Congo Red and Methylene Blue from Aqueous Solutions by Vermicompost-Derived Biochars

    PubMed Central

    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. PMID:27144922

  9. Decolourization of Methylene Blue in Water Using Bentonite Impregnated with Ti and Ag as Photocatalyst.

    PubMed

    Wu, Edward Ming-Yang; Kuo, Shu-Lung

    2015-08-01

    This article used bentonite impregnated with titanium and silver, respectively, as photocatalyst, to degrade methylene blue (MB) under conditions of MB solutions exposed to sodium lamp and sunlight. Due to the semi-conducting properties of synthesized bentonite catalysts, when exposed to sodium lamp and sunlight, catalyst particles are excited for photocatalysis to achieve decolourization. After an FT-IR analysis, this study finds that smectite catalysts have significant and complicated wave crests between the fingerprint area with wave numbers 415~600 cm⁻¹ and 750~1170 cm⁻¹. The bentonite impregnated with Ti(4+) (Sm-Ti) and with Ag⁺ (Sm-Ag) removes MB through the mechanisms of adsorption and degradation, while the commercial product of titanium dioxide (TiO₂) only exhibits the capability of MB degradation. At present, a heterogeneous photocatalytic system has been fully applied for use in daily life, with its efficiency determined by the free radical action of electrons and holes, the generation efficiency of ·OH. PMID:26237689

  10. Twenty years of vasoplegic syndrome treatment in heart surgery. Methylene blue revised

    PubMed Central

    Evora, Paulo Roberto Barbosa; Alves, Lafaiete; Ferreira, Cesar Augusto; Menardi, Antônio Carlos; Bassetto, Solange; Rodrigues, Alfredo José; Scorzoni, Adilson; Vicente, Walter Vilella de Andrade

    2015-01-01

    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. PMID:25859872

  11. New Twist on an Old Favorite: Gentian Violet and Methylene Blue Antibacterial Foams

    PubMed Central

    Edwards, Karen

    2016-01-01

    Significance: Absorptive antibacterial dressings that assist in controlling bioburden without risks of cytotoxicity or residual absorption can be effectively used for prolonged periods throughout the wound healing continuum. Recent Advances: Until recently, gentian violet and methylene blue (GV/MB) antibacterial dressings have been commercially available only in polyvinyl alcohol (PVA) foam; polyurethane (PU) foam bonded with GV and MB with thin film backing is now commercially available. GV/MB PU foam does not require hydration or a necessary secondary dressing. GV/MB PVA and PU foam dressings were recently granted FDA clearance as antibacterial dressings, as opposed to bacteriostatic dressings as previously classified. Within the class of antibacterial dressings, GV/MB foam dressings are of lower cost alternative to silver- or iodine-based antibacterial dressings with no risk of absorption of any of the foam components into the tissues. Critical Issues: Control of wound bioburden levels by antibacterial agents and absorption of excess exudate are crucial in preventing infections that drastically increase the price of wound care. Use of GV/MB dressings may improve wound healing outcomes and decrease overall costs through super absorption, promotion of autolytic debridement, bioburden reduction, ease of use, and decreased dressing change frequency. Future Directions: Evolution in resistant bacterial strains will drive continual changes in advanced wound care products. Demand will increase for economically priced, versatile wound care dressings that assist in debridement, maintain a moist wound environment, absorb and trap bacterial debris, and decrease dressing change frequency. PMID:26858911

  12. Cellular and Molecular Actions of Methylene Blue in the Nervous System

    PubMed Central

    Oz, Murat; Lorke, Dietrich E.; Hasan, Mohammed; Petroianu, George A.

    2010-01-01

    Methylene Blue (MB), following its introduction to biology in the 19th century by Ehrlich, has found uses in various areas of medicine and biology. At present, MB is the first line of treatment in methemoglobinemias, is used frequently in the treatment of ifosfamide-induced encephalopathy, and is routinely employed as a diagnostic tool in surgical procedures. Furthermore, recent studies suggest that MB has beneficial effects in Alzheimer's disease and memory improvement. Although the modulation of the cGMP pathway is considered the most significant effect of MB, mediating its pharmacological actions, recent studies indicate that it has multiple cellular and molecular targets. In the majority of cases, biological effects and clinical applications of MB are dictated by its unique physicochemical properties including its planar structure, redox chemistry, ionic charges, and light spectrum characteristics. In this review article, these physicochemical features and the actions of MB on multiple cellular and molecular targets are discussed with regard to their relevance to the nervous system. PMID:19760660

  13. Chemical convection in the methylene-blue-glucose system: Optimal perturbations and three-dimensional simulations

    NASA Astrophysics Data System (ADS)

    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.

  14. Designing metallic iron based water filters: Light from methylene blue discoloration.

    PubMed

    Btatkeu-K, B D; Tchatchueng, J B; Noubactep, C; Caré, S

    2016-01-15

    Available water filtration systems containing metallic iron (Fe(0) filters) are pragmatically designed. There is a lack of sound design criteria to exploit the full potential of Fe(0) filters. A science-based design relies on valuable information on processes within a Fe(0) filter, including chemical reactions, hydrodynamics and their relation to the performance of the filter. The aim of this study was to establish a simple method to evaluate the initial performance of Fe(0) filters. The differential adsorptive affinity of methylene blue (MB) onto sand and iron oxide is exploited to characterize the evolution of a Fe(0)/sand system using the pure sand system as operational reference. Five systems were investigated for more than 70 days: pure sand, pure Fe(0), Fe(0)/sand, Fe(0)/pumice and Fe(0)/sand/pumice. Individual systems were characterized by the extent of changes in pH value, iron breakthrough, MB breakthrough and hydraulic conductivity. Results showed that for MB discoloration (i) pure sand was the most efficient system, (ii) hybrid systems were more sustainable than the pure Fe(0) system, and (iii) the pores of used pumice are poorly interconnected. Characterizing the initial reactivity of Fe(0) filters using MB discoloration has introduced a powerful tool for the exploration of various aspects of filter design. PMID:26518123

  15. Adsorption of methylene blue on low-cost adsorbents: a review.

    PubMed

    Rafatullah, Mohd; Sulaiman, Othman; Hashim, Rokiah; Ahmad, Anees

    2010-05-15

    In this article, the use of low-cost adsorbents for the removal of methylene blue (MB) from solution has been reviewed. Adsorption techniques are widely used to remove certain classes of pollutants from waters, especially those which are not easily biodegradable. The removal of MB, as a pollutant, from waste waters of textile, paper, printing and other industries has been addressed by the researchers. Currently, a combination of biological treatment and adsorption on activated carbon is becoming more common for removal of dyes from wastewater. Although commercial activated carbon is a preferred adsorbent for color removal, its widespread use is restricted due to its relatively high cost which led to the researches on alternative non-conventional and low-cost adsorbents. The purpose of this review article is to organize the scattered available information on various aspects on a wide range of potentially low-cost adsorbents for MB removal. These include agricultural wastes, industrial solid wastes, biomass, clays minerals and zeolites. Agricultural waste materials being highly efficient, low cost and renewable source of biomass can be exploited for MB remediation. It is evident from a literature survey of about 185 recently published papers that low-cost adsorbents have demonstrated outstanding removal capabilities for MB. PMID:20044207

  16. Reversibility of photoelectrochromism at the TiO{sub 2}/methylene blue interface

    SciTech Connect

    Tacconi, N.R. de; Carmona, J.; Rajeshwar, K.

    1997-07-01

    This paper describes the photoelectrochromic bleaching and recoloration of methylene blue in aqueous or methanolic slurry suspensions of TiO{sub 2}. Using simple modification of a UV-visible diode-array spectrometer setup, the spectral changes undergone by the dye in these solutions were monitored in situ during irradiation of the TiO{sub 2} particles and in the dark. A particular focus of this study was a systematic investigation of factors underpinning the chemical and electrochemical (kinetic) reversibility of the dye bleaching-recoloration sequence. Thus, choice of solution pH and hole capture agents is shown to be critical to the suppression of parasitic chemical and photochemical reactions involving the dye. On the other hand, dye adsorption on the TiO{sub 2} surface, the solvent medium itself, and its O{sub 2} content are all important factors in dictating the kinetic reversibility of the photoelectrochromic process. Finally, the practical implications of the findings are presented.

  17. Degradation of aqueous methylene blue using an external loop airlift sonophotoreactor: Statistical analysis and optimization.

    PubMed

    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. PMID:27128152

  18. Formaldehyde dehydrogenase preparations from Methylococcus capsulatus (Bath) comprise methanol dehydrogenase and methylene tetrahydromethanopterin dehydrogenase.

    PubMed

    Adeosun, Ekundayo K; Smith, Thomas J; Hoberg, Anne-Mette; Velarde, Giles; Ford, Robert; Dalton, Howard

    2004-03-01

    In methylotrophic bacteria, formaldehyde is an important but potentially toxic metabolic intermediate that can be assimilated into biomass or oxidized to yield energy. Previously reported was the purification of an NAD(P)(+)-dependent formaldehyde dehydrogenase (FDH) from the obligate methane-oxidizing methylotroph Methylococcus capsulatus (Bath), presumably important in formaldehyde oxidation, which required a heat-stable factor (known as the modifin) for FDH activity. Here, the major protein component of this FDH preparation was shown by biophysical techniques to comprise subunits of 64 and 8 kDa in an alpha(2)beta(2) arrangement. N-terminal sequencing of the subunits of FDH, together with enzymological characterization, showed that the alpha(2)beta(2) tetramer was a quinoprotein methanol dehydrogenase of the type found in other methylotrophs. The FDH preparations were shown to contain a highly active NAD(P)(+)-dependent methylene tetrahydromethanopterin dehydrogenase that was the probable source of the NAD(P)(+)-dependent formaldehyde oxidation activity. These results support previous findings that methylotrophs possess multiple pathways for formaldehyde dissimilation. PMID:14993320

  19. Enhanced photocatalytic activity of TiO2-C hybrid aerogels for methylene blue degradation

    NASA Astrophysics Data System (ADS)

    Shao, Xia; Lu, Wencong; Zhang, Rui; Pan, Feng

    2013-10-01

    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.

  20. Improving the performance of methylene blue sensitized photopolymer by doping with nickel ion

    NASA Astrophysics Data System (ADS)

    Aswathy, G.; Rajesh, C. S.; Sreekumar, K.; Joseph, R.; Kartha, C. Sudha

    2016-05-01

    Holographic performance of an economically cheap metal ion doped photopolymer material is presented. We investigated the effect of incorporation of nickel ion into the methylene blue sensitized poly (vinyl alcohol)/acrylamide (MBPVA/AA) photopolymer system. The composition and preliminary characterization of the developed photopolymer material is reported. The presence of nickel ion improves the diffraction efficiency, stability of the material and it operates in a wide range of spatial frequencies (550-2000 lines/mm) at exposure energy of 100 mJ/cm2. When nickel ion concentration was 0.01 mM, maximum diffraction efficiency of 84% at exposure energy of 100 mJ/cm2 with spatial frequency 1335 lines/mm could be achieved for gratings recorded using wavelength of 632.8 nm. The material showed panchromaticity with more than 70% diffraction efficiency in both blue and green regions. Effects of humidity and temperature on the stored gratings were studied by keeping films in different environmental conditions. Suitability of recording large area holograms was also explored.

  1. Enhanced photocatalytic activity of TiO2-C hybrid aerogels for methylene blue degradation

    PubMed Central

    Shao, Xia; Lu, Wencong; Zhang, Rui; Pan, Feng

    2013-01-01

    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. PMID:24145581

  2. Immunochemical detection of the occupational allergen, methylene diphenyl diisocyanate (MDI), in situ.

    PubMed

    Wisnewski, Adam V; Liu, Jian

    2016-02-01

    Diisocyanate chemicals essential to polyurethane production are a well-recognized cause of occupational asthma. The pathogenesis of diisocyanate-induced asthma, including the pathways by which the chemical is taken up and its distribution in exposed tissue, especially the lung, remains unclear. We developed an antiserum with specificity for methylene diphenyl diisocyanate (MDI) the most abundantly produced and utilized diisocyanate world-wide, and established its ability to detect MDI in situ. Polyclonal MDI-specific IgG was induced by immunizing rabbits with MDI-conjugated to keyhole limpet hemocyanin (KLH) emulsified in complete Freund's adjuvant, followed by two booster injections with incomplete Freund's adjuvant. The antiserum contains IgG that recognize a variety of different MDI conjugated proteins, but not unconjugated or mock exposed proteins by dot blot analysis. The antiserum further demonstrates specificity for proteins conjugated with MDI, but not other commonly used diisocyanates. Immunochemical studies with cytospun airway cells and formalin-fixed paraffin embedded lung tissue sections from mice intranasally exposed to MDI (as reversibly reactive glutathione conjugates, e.g. GSH-MDI) demonstrated the antiserum's ability to detect MDI in tissue samples. The data demonstrate penetration of MDI into the lower airways, localized deposition in the epithelial region surrounding airways, and uptake by alveolar macrophages. The new immunochemical reagent should be useful for further studies delineating the uptake and tissue distribution of MDI, especially as it relates to adverse health effects from exposure. PMID:26690039

  3. Adsorption of methylene blue on biochar microparticles derived from different waste materials.

    PubMed

    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. PMID:26818183

  4. Chemical convection in the methylene-blue-glucose system: Optimal perturbations and three-dimensional simulations.

    PubMed

    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. PMID:25493878

  5. Plasma treated with methylene blue and light: clinical efficacy and safety profile.

    PubMed

    Lozano, Miguel; Cid, Joan; Müller, Thomas H

    2013-10-01

    Methylene blue (MB) was the first method developed for pathogen inactivation of a labile blood component that was introduced in 1991. MB and light (MBL) inactivates most lipid-enveloped viruses and those non-enveloped are, in general, resistant. MBL treatment affects several coagulation factors, most noticeably fibrinogen and factor VIII with a loss of approximately 30%. Using endogenous thrombin potential, a global hemostasis evaluation, MBL treatment of plasma resulted in a 7% to 10% of reduction in thrombin potential. Although, originally, the scientific evidence of its efficacy and safety were scarce, the 4.4 million of units transfused have provided a wide body of evidence of its efficacy and safety in most of clinical situations. Nevertheless, some doubts have arisen about the efficacy of MBL plasma when used as a replacement solution for plasma exchange in the treatment of patients suffering from TTP. Probably only randomized controlled trials would provide definite evidence to clarify this point. Reports of severe allergic reactions in a few patients receiving MBL plasma have provoked the recent decision to remove the product from the market in France. Interestingly hemovigilance data in countries such as the same France, Spain, and United Kingdom have not corroborated an increase in severe allergic reaction. Close monitoring of the patients receiving plasma and suffering from allergic reactions and reporting to hemovigilance schemes hopefully will provide the needed data to definitely establish the exact risk of this complication for MBL vs other types of plasma. PMID:24075476

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

    PubMed

    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- PMID:27433681

  7. Preparation of modified semi-coke by microwave heating and adsorption kinetics of methylene blue.

    PubMed

    Wang, Xin; Peng, Jin-Hui; Duan, Xin-Hui; Srinivasakannan, Chandrasekar

    2013-01-01

    Preparation of modified semi-coke has been achieved, using phosphoric acid as the modifying agent, by microwave heating from virgin semi-coke. Process optimization using a Central Composite Design (CCD) design of Response Surface Methodology (RSM) technique for the preparation of modifies semi-coke is presented in this paper. The optimum conditions for producing modified semi-coke were: concentration of phosphoric acid 2.04, heating time 20 minutes and temperature 587 degrees C, with the optimum iodine of 862 mg/g and yield of 47.48%. The textural characteristics of modified semi-coke were analyzed using scanning electron microscopy (SEM) and nitrogen adsorption isotherm. The BET surface area of modified semi-coke was estimated to be 989.60 m2/g, with the pore volume of 0.74 cm3/g and a pore diameter of 3.009 nm, with micro-pore volume contributing to 62.44%. The Methylene Blue monolayer adsorption capacity was found to be mg/g at K. The adsorption capacity of the modified semi-coke highlights its suitability for liquid phase adsorption application with a potential usage in waste water treatment. PMID:24779145

  8. Cellular and molecular actions of Methylene Blue in the nervous system.

    PubMed

    Oz, Murat; Lorke, Dietrich E; Hasan, Mohammed; Petroianu, George A

    2011-01-01

    Methylene Blue (MB), following its introduction to biology in the 19th century by Ehrlich, has found uses in various areas of medicine and biology. At present, MB is the first line of treatment in methemoglobinemias, is used frequently in the treatment of ifosfamide-induced encephalopathy, and is routinely employed as a diagnostic tool in surgical procedures. Furthermore, recent studies suggest that MB has beneficial effects in Alzheimer's disease and memory improvement. Although the modulation of the cGMP pathway is considered the most significant effect of MB, mediating its pharmacological actions, recent studies indicate that it has multiple cellular and molecular targets. In the majority of cases, biological effects and clinical applications of MB are dictated by its unique physicochemical properties including its planar structure, redox chemistry, ionic charges, and light spectrum characteristics. In this review article, these physicochemical features and the actions of MB on multiple cellular and molecular targets are discussed with regard to their relevance to the nervous system. PMID:19760660

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

    PubMed

    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. PMID:25661173

  10. Immobilization of methylene blue onto bentonite and its application in the extraction of mercury (II).

    PubMed

    Hassanien, Mohamed M; Abou-El-Sherbini, Khaled S; Al-Muaikel, Nayef S

    2010-06-15

    Methylene blue was immobilized onto bentonite (BNT). The modified clay (MB-BNT) was used to extract Hg(2+) at pH 6.0 yielding Hg-MB-BNT. BNT, MB-BNT and Hg-MB-BNT were characterized by X-ray diffractometry, infrared spectra, and elemental and thermogravimetric analyses. MB is suggested to be intercalated into the major phase of BNT; montmorillonite mineral (MMT), lying parallel to the aluminosilicate layers, with a capacity of 36 mequiv./100g. MB-BNT shows good stability in 0.1-1M hydrochloric or nitric acids, ammonium hydroxide, and concentrated Na(+), K(+) or NH(4)(+) chlorides or iodides. It shows good selectivity towards Hg(2+) with an extraction capacity of 37 mequiv./100g in the presence of I(-) giving rise to a ratio of MB/Hg(2+)/I(-) 1:1:3 in the clay phase. Extracted Hg(2+) could be quantitatively recovered by ammonia buffer at pH 8.5. MB-BNT was successfully applied to recover Hg(2+) from spiked natural water and cinnabar mineral samples using the optimum conditions; pH 6.0, time of stirring 10 min and 10 mL of 0.05 M NH(4)Cl/NH(4)OH at pH 8.5 as eluent. PMID:20133060

  11. Photophysical and antibacterial properties of complex systems based on smectite, a cationic surfactant and methylene blue.

    PubMed

    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. PMID:26248233

  12. Distribution of Methylene Blue after Injection into the Epidural Space of Anaesthetized Pregnant and Non-Pregnant Sheep

    PubMed Central

    Moll, Xavier; García, Felix; Ferrer, Rosa Isabel; Santos, Laura; Aguilar, Adrià; Andaluz, Anna

    2014-01-01

    The aim of the study was to determine the distribution of different volumes of methylene blue solution injected into the epidural space in anaesthetized pregnant and non-pregnant sheep, to evaluate its cranial distribution and to compare between them. Fifteen pregnant and fifteen non-pregnant sheep were included in the study. Sheep were anaesthetized and received 0.05, 0.1, or 0.2 mL/kg of a lumbosacral epidural solution containing 0.12% methylene blue in 0.9% saline. Thirty minutes after the epidural injection, the ewes were euthanized. The extension of the dye within the epidural space was measured, and the correlation between the volume of the dye injected and the number of stained vertebrae was evaluated. The cranial migration of the dye between pregnant and non-pregnant sheep was also compared. The results show that the volume of methylene blue injected epidurally into pregnant and non-pregnant sheep correlated directly with its cephalic distribution into the epidural space; and a volume of 0.1 mL/kg or 0.2 mL/kg stained up to the first lumbar segment in pregnant and non-pregnant sheep, respectively. Also, the results suggest that the volume of drugs administered into the epidural space of pregnant sheep should be half the volume that would be used in non-pregnant sheep. PMID:24709655

  13. Post-Session Administration of USP Methylene Blue Facilitates the Retention of Pathological Fear Extinction and Contextual Memory in Phobic Adults

    PubMed Central

    Telch, Michael J.; Bruchey, Aleksandra K.; Rosenfield, David; Cobb, Adam R.; Smits, Jasper; Pahl, Sandra; Gonzalez-Lima, F.

    2015-01-01

    Objective Preclinical studies have shown that low-dose USP methylene blue increases mitochondrial cytochrome oxidase activity in the brain and improves memory retention after learning tasks, including fear extinction. We report on the first controlled experiment to examine the memory-enhancing effects of post-training methylene blue administration on retention of fear extinction and contextual memory following fear extinction training. Method Adults (N = 42) displaying marked claustrophobic fear were randomized to double-blind administration of 260 mg of methylene blue versus placebo immediately following six five-minute extinction trials to an enclosed chamber. Retesting occurred one month later to assess fear renewal as indexed by peak fear during exposure to a non-trained enclosed chamber with the prediction that methylene blue's effects would vary as a function of fear reduction achieved during extinction training. Incidental contextual memory was assessed 1 and 30 days after training to assess the cognitive enhancing effects of methylene blue independent of its effects on fear attenuation. Results Consistent with predictions, participants displaying low end fear at post-training showed significantly less fear at follow-up if they received methylene blue post-training relative to placebo. In contrast, participants displaying moderate to high levels of post-training fear tended to fare worse at follow-up relative to placebo. Methylene blue's enhancement of contextual memory was unrelated to initial or post-training claustrophobic fear. Conclusions Methylene blue enhances memory and the retention of fear extinction when administered after a successful exposure session, but may have a deleterious effect on extinction when administered after an unsuccessful exposure session. PMID:25018057

  14. Effects of [alpha]-methyl group substitution on the dimerization products of furan-based o-quinodimethanes

    SciTech Connect

    Leung, M.K.; Trahanovsky, W.S. Ames Lab., IA )

    1995-01-25

    3-Ethylidene-2-methylene-(12), 2-ethylidene-3-methylene-(13), and 2,3-diethylidene-(14)2,3-dihydrofurans were prepared by fluoride induced 1,4-conjugative elimination of trimethylsilyl acetate from the appropriate precursors. The [sup 1]H NMR spectra of these furan-based o-quinodimethanes were obtained and the dimerization products of each were studied. It was found that a methyl group at the 3-methylene position retards the rate of dimerization which is consistent with the previously proposed dimerization mechanism, the two-step mechanism involving rate-determining formation of a diradical intermediate followed by rapid cyclization of the diradical. 25 refs., 8 figs., 6 tabs.

  15. Implementation and evaluation of an analytical method for a novel derivatizing agent to measure 4,4'-methylene diphenyl diisocyanate atmospheres.

    PubMed

    Puscasu, Silvia; Aubin, Simon; Spence, Mark; Gagné, Sébastien

    2016-08-01

    Accurate measurement of 4,4'-methylene diphenyl diisocyanate (MDI) atmospheres is a challenge since the molecule is both chemically reactive and likely to be present in aerosol form when heated and sprayed because of its low vapor pressure. Meeting this challenge requires optimizing both the sampling device used and the derivatization agent employed to stabilize the isocyanate functional group. This study describes the use of a novel derivatization reagent for isocyanate sampling to address the challenge of MDI aerosol exposure sampling. Like most conventional derivatizing agents for isocyanates, 1,8-diaminonapthalene (DAN) reacts with isocyanate functional groups to form a urea. However, unlike other isocyanate derivatizing agents, the sample workup procedure with DAN includes a second step which yields a single analyte molecule, perimidone, for each isocyanate group. This feature gives DAN the unique ability to assess exposure to "total reactive isocyanate group" (TRIG). The analytical method implemented to quantitate the perimidone uses liquid chromatography coupled with tandem mass spectrometry. Positive mode ionization led to LOD and LOQ of 10 ng/mL and 34 ng/mL, respectively. The dynamic range was from 50-2000 ng/mL (with R(2) ≥ 0.990), which corresponds to TRIG concentrations in air from 0.07-3.04 µg/m(3), assuming 60 min of sampling at 10 L/min (based on use of the CIP-10M sampler). The intra-day and inter-day analytical precisions were <4% for all of the concentration levels tested, and the accuracy was within an appropriate range of 98 ± 2%. Minimal matrix effect was observed, and a total recovery of 109% was obtained. The approach seems to be promising for TRIG measurements and further work is planned to establish DAN method behavior in samplers used for workplace monitoring. PMID:26954368

  16. Group Counseling

    ERIC Educational Resources Information Center

    Mahler, Clarence A.

    1971-01-01

    This article reviews the major concerns of group counseling and differentiates among group guidance, group counseling, and group therapy. It also evaluates the research status of group counseling and presents implications for the future of this approach. Comment by Carl E. Thoresen follows. (Author)

  17. Working Group 7 Summary

    SciTech Connect

    Nagaitsev S.; Berg J.

    2012-06-10

    The primary subject of working group 7 at the 2012 Advanced Accelerator Concepts Workshop was muon accelerators for a muon collider or neutrino factory. Additionally, this working group included topics that did not fit well into other working groups. Two subjects were discussed by more than one speaker: lattices to create a perfectly integrable nonlinear lattice, and a Penning trap to create antihydrogen.

  18. Bimodal porous silica microspheres decorated with polydopamine nano-particles for the adsorption of methylene blue in fixed-bed columns.

    PubMed

    Ataei-Germi, Taher; Nematollahzadeh, Ali

    2016-05-15

    Bimodal meso/macro-porous silica microspheres (MSM) were synthesized by a modified sol-emulsion-gel method and then the surface was coated with polydopamine (PDA) nano-particles of 39nm in size. Focusing on the encouraging properties of the synthesized adsorbent, such as high specific surface area (612.3m(2)g(-1), because of mesopores), fast mass transfer (0.9-2.67×10(-3)mLmin(-1)mg, because of macropores), and abundant "adhesive" functional groups of PDA, it was used for the removal of methylene blue (MB) from aqueous solution in a fixed-bed column. The effect of different parameters such as pH, initial concentration, and flow rate was studied. The results revealed that an appropriate sorption condition is an alkaline solution of MB (e.g., pH 10) at low flow rate (less than 5mLmin(-1)). Furthermore, the compatibility of the experimental data with mathematical models such as Thomas and Adams-Bohart was investigated. Both of the models showed a good agreement with the experimental data (R(2)=0.9954-0.9994), and could be applied for the prediction of the column properties and breakthrough curves. Regeneration of the column was performed by using HCl solution with a concentration of 0.1M as an eluent. PMID:26943002

  19. On structure and methylene blue degradation activity of an Aurivillius-type photocatalyst of Bi4V2O11 nanoparticles

    NASA Astrophysics Data System (ADS)

    Lu, Yuting; Pu, Yinfu; Wang, Jing; Qin, Chuangxiang; Chen, Cuili; Seo, Hyo Jin

    2015-08-01

    Aurivillius-type photocatalyst of Bi4V2O11 nanoparticles with an average particle size of 45 nm was prepared by the modified Pechini method. The sample was investigated by X-ray powder diffraction (XRD) and the structural refinement. The nanoparticles were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopic (XPS) and UV-vis absorption spectrum. Bi4V2O11 nanoparticles show an efficient absorption in the UV-vis light wavelength region with a narrowed band gap energy of 2.08 eV and an indirect allowed electronic transition. The photocatalytic activities of Bi4V2O11 nanoparticles were evaluated by photodegradation of methylene blue (MB) under visible-light irradiation in air atmosphere. These results indicate that Bi4V2O11 could be a potential photocatalyst driven by visible-light. Hybridization of the 6s and 6p orbitals of Bi3+ and the resulting lone electron pair yields interesting properties. The effective photocatalytic activity was discussed on the base of the crystal structure characteristic such as polar (VO3.5□0.5)2- anionic groups, Aurivillius-type (Bi2O2)2+ layers and long distance of the nearest V-V in the lattices, etc.

  20. Studies on growth, structural, dielectric, laser damage threshold, linear and nonlinear optical properties of methylene blue admixtured L-arginine phosphate single crystal

    NASA Astrophysics Data System (ADS)

    Peramaiyan, G.; Pandi, P.; Bhagavannarayana, G.; Mohan Kumar, R.

    2012-12-01

    L-Arginine phosphate (LAP) and methylene blue dye admixtured L-arginine phosphate single crystals were grown by slow cooling technique and their cell parameters, crystalline perfection, dopant inclusion were confirmed by single crystal, powder X-ray diffraction and high resolution X-ray diffraction analyses respectively. The modes of vibrations of different functional groups present in pure and dye admixtured LAP crystals have been identified by FTIR spectral analysis. The UV-Vis-NIR spectral study was performed on the grown crystals and found that the crystals are transparent in the entire visible-NIR region. The dielectric measurement was carried out on the grown crystals as a function of frequency at room temperature. The microhardness hardness study on (1 0 0) plane of grown crystals reveals the mechanical behavior of the crystals. The laser damage threshold value significantly enhanced for dye admixtured crystal in comparison with pure LAP crystal. The relative SHG efficiency of methylane blue admixtured LAP crystal was found to be 1.3 times higher than that of pure LAP crystal.