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Sample records for additional methylene group

  1. 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.

  2. 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.

  3. 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

  4. Methylene Blue Dichromated-Gelatin Holograms: Antihumidity Method for Taking Off Strongly Adsorbing Humidity Groups

    NASA Astrophysics Data System (ADS)

    Wang, Ketai; Guo, Lurong; Zhu, Jianhua; Zhang, Weiping; Cheng, Bo

    1998-01-01

    A new, to our knowledge, method of modifying methylene blue dichromated-gelatin (MBDCG) holograms by use of ninhydrin and removal of their amino groups and carboxyl groups, which strongly adsorb humidity, has been developed. The modified MBDCG holograms are stable for 1000-line /mm gratings (diffractional efficiency of 95%) in a high-humidity environment (relative humidity of 80% -85%). The modifying reaction does not affect the diffraction efficiency of the MBDCG holograms. It is demonstrated that the amino groups and carboxyl groups of the side chains in the gelatin do not undergo the chelation reaction with Cr iii in the sensitive area.

  5. Detection of chemisorbed methyl and methylene groups: Surface chemistry of methyl iodide on Pt(111)

    SciTech Connect

    Zaera, F.; Hoffmann, H. )

    1991-08-08

    The thermal chemistry of methyl iodide on Pt(111) surfaces was studied by using thermal programmed desorption (TPD), X-ray photoelectron (XPS), and reflection-absorption (RAIRS) spectroscopies. Spectra obtained at low temperatures for both normal and fully deuterated methyl iodide indicate that chemisorption is molecular and that the adsorption geometry changes with coverage, starting with a tilted configuration after small doses and switching to a structure where the C-I bond is perpendicular to the surface above half-saturation. The only reaction that can be thermally activated at low coverages is a C-I bond breaking step, which is then followed by total dehydrogenation and by hydrogen desorption. At higher coverages, however, an appreciable amount of methane also desorbs, and both methyl and methylene groups form on the surface.

  6. Molecular Orientation Analysis of Alkyl Methylene Groups from Quantitative Coherent Anti-Stokes Raman Scattering Spectroscopy.

    PubMed

    Zhang, Chi; Wang, Jie; Jasensky, Joshua; Chen, Zhan

    2015-04-16

    Quantitative data analysis in coherent anti-Stokes Raman scattering (CARS) spectroscopy is important for extracting molecular structural information. We developed a method to derive molecular tilt angle with respect to the surface normal based on quantitative CARS spectral analysis. We showed that the tilt angle of methylene alkyl chains on a surface can be directly obtained from the CH2 symmetric/asymmetric peak ratio in a CARS spectrum. The lipid alkyl chain tilt angle from a lipid monolayer was measured to be ∼0° and was verified by sum frequency generation spectroscopy, which probes the orientations of the lipid methyl end groups. The tilt angle of a silane monolayer alkyl chain was derived to be ∼35°, which agrees with the theoretical prediction. This method is submonolayer sensitive and can also be used to interpret polarization-dependent signals in CARS microscopy. It can be applied to elucidate detailed molecular structure from CARS spectroscopic and microscopic measurements.

  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. 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

  10. 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

  11. 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

  12. Preparation of highly developed mesoporous activated carbon fiber from liquefied wood using wood charcoal as additive and its adsorption of methylene blue from solution.

    PubMed

    Ma, Xiaojun; Zhang, Fan; Zhu, Junyan; Yu, Lili; Liu, Xinyan

    2014-07-01

    Activated carbon fiber (C-WACF) with super high surface area and well-developed small mesopores were prepared by liquefied wood and uses wood charcoal (WC) as additive. The characterization and properties of C-WACF were investigated by XRD, XPS and N2 adsorption. Results showed the pore development was significant at temperatures >750°C, and reached a maximum BET surface area (2604.7 m(2)/g) and total pore volume (1.433 cm(3)/g) at 850°C, of which 86.8% was from the contribution of the small mesopores of 2-4 nm. It was also found that the mesopore volume and methylene blue adsorption of C-WACF were highly increased as the temperature increases from 750 to 850°C. Additionally, the reduction of graphitic layers, the obvious changes of functional groups and the more unstable carbons on the surface of C-WACF, which played important roles in the formation of mesopores, were also observed.

  13. 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

  14. 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

  15. Preferential adsorption behavior of methylene blue dye onto surface hydroxyl group enriched TiO2 nanotube and its photocatalytic regeneration.

    PubMed

    Natarajan, Thillai Sivakumar; Bajaj, Hari C; Tayade, Rajesh J

    2014-11-01

    The present manuscript focus on the synthesis of surface hydroxyl group enriched titanium dioxide nanotube (TNT) by hydrothermal method for preferential adsorption of methylene blue (MB) dye. The mixture of methylene blue (MB) and rhodamine B (RhB) dye was used to study the preferential adsorption nature of TNT. The synthesized TNT were characterized by various techniques such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption, and ammonia-temperature programmed desorption (NH3-TPD) analysis. Result demonstrated that enhancement in the surface area of TNT and higher number of hydroxyl group on the surface of TNT. In the binary mixture, the adsorption of MB dye was 12.9 times higher as compared to RhB dye, which clearly indicated the preferential adsorption of MB dye on TNT surface. The preferential interaction of MB on TNT is due to the electrostatic interaction between the cationic MB and negatively charged TNT surface. The preferential adsorption of MB dye was studied by applying Langmuir, Freundlich and Sips isotherm; pseudo-first and second-order kinetic model. Furthermore, the regeneration of dye adsorbed TNT was carried out by eco-friendly photocatalytic process under the irradiation of ultraviolet light.

  16. 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…

  17. 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

  18. 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

  19. Reaction pathway of methylenation of carbonyl compounds with bis(iodozincio)methane.

    PubMed

    Sada, Mutsumi; Komagawa, Shinsuke; Uchiyama, Masanobu; Kobata, Masami; Mizuno, Tsuyoshi; Utimoto, Kiitiro; Oshima, Koichiro; Matsubara, Seijiro

    2010-12-15

    About 40 years have passed since methylene dizinc reagent was discovered as a substitute for Wittig reagent. Density functional theory (DFT) calculations have been performed to understand the reaction pathways of methylenation of carbonyl compounds with bis(iodozincio)methane. The present computational/theoretical study concluded that the methylenation reaction with gem-dizinc reagent proceeds as a two-step reaction, that is, methylene addition (RDS) and olefination. In the first step, the nucleophilic attack of the CH2 group enhanced by two Zn proceeds under the assistance of the electrophilic activation of the carbonyl group with the Zn atom. In the second step, the olefination is facilitated by both Zn atoms of the gem-dizinc reagent without an electron transfer process. PMID:21082850

  20. 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).

  1. Methylene chloride: a 2-year inhalation toxicity and oncogenicity study in rats

    SciTech Connect

    Nitschke, K.D.; Burek, J.D.; Bell, T.J.; Kociba, R.J.; Rampy, L.W.; McKenna, M.J.

    1988-07-01

    Male and female Sprague-Dawley rats were exposed to 0, 50, 200, or 500 ppm methylene chloride for 6 hr/day, 5 days/week for 2 years. Blood carboxyhemoglobin levels were elevated in a dose-dependent (less than linear) manner in rats exposed to 50-500 ppm methylene chloride. Histopathologic lesions related to methylene chloride exposure were confined to the liver and mammary tissue of rats. An increased incidence of hepatocellular vacuolization was observed in male and female rats exposed to 500 ppm methylene chloride. Female rats exposed to 500 ppm methylene chloride also had an increased incidence of multinucleated hepatocytes and number of spontaneous benign mammary tumors/tumor-bearing rat (adenomas, fibromas, and fibroadenomas with no progression toward malignancy); the incidence of benign mammary tumors in female rats exposed to 50 or 200 ppm methylene chloride was comparable to historical control values. No increase in the number of any malignant tumor type was observed in rats exposed to concentrations as high as 500 ppm methylene chloride. Additional groups of female rats were exposed to 500 ppm methylene chloride for the first 12 months or the last 12 months of the 24-month study. The response observed in female rats exposed to 500 ppm for the first 12 months was the same as that observed in female rats exposed to 500 ppm for 2 years. Conversely, the response observed in female rats exposed to 500 ppm during the last 12 months of the study was similar to that observed in control animals. Based upon the results of this study, the no-adverse-effect level for chronic inhalation exposure of Sprague-Dawley rats was judged to be 200 ppm methylene chloride.

  2. 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…

  3. 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.

  4. 34 CFR 300.308 - Additional group members.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CHILDREN WITH DISABILITIES Evaluations, Eligibility Determinations, Individualized Education Programs, and 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...

  5. 34 CFR 300.308 - Additional group members.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CHILDREN WITH DISABILITIES Evaluations, Eligibility Determinations, Individualized Education Programs, and 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...

  6. 34 CFR 300.308 - Additional group members.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CHILDREN WITH DISABILITIES Evaluations, Eligibility Determinations, Individualized Education Programs, and 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...

  7. 34 CFR 300.308 - Additional group members.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CHILDREN WITH DISABILITIES Evaluations, Eligibility Determinations, Individualized Education Programs, and 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...

  8. 34 CFR 300.308 - Additional group members.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CHILDREN WITH DISABILITIES Evaluations, Eligibility Determinations, Individualized Education Programs, and 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...

  9. The low photo-inactivation rate of bacteria in human plasma II. Inhibition of methylene blue bleaching in plasma and effective bacterial destruction by the addition of dilute acetic acid to human plasma.

    PubMed

    Chen, Jie; Cesario, Thomas C; Li, Runze; Er, Ali O; Rentzepis, Peter M

    2015-10-01

    Methylene blue (MB) and other photo-sensitizer molecules have been recognized as effective means for the inactivation of bacteria and other pathogens owing to their ability to photo-generate reactive oxygen species (ROS) including singlet oxygen. These reactive species react with the membrane of the bacteria causing their destruction. However, the efficiency of MB to destroy bacteria in plasma is very low because the MB 660 nm absorption band, that is responsible for the ROS generation, is bleached. The bleaching of MB, in plasma, is caused by the attachment of a hydrogen atom to the central ring nitrogen of MB, which destroys the ring conjugation and forms Leuco-MB which does not absorb in the 600 nm region. In this paper we show that addition of dilute acetic acid, ∼10(-4) M, to human plasma, prevents H-atom attachment to MB, allowing MB to absorb at 660 nm, generates singlet oxygen and thus inactivates bacteria. The mechanism proposed, for preventing MB bleaching in plasma, is based on the oxidation of cysteine to cystine, by reaction with added dilute acetic acid, thus eliminating the availability of the thiol hydrogen atom which attaches to the MB nitrogen. It is expected that the addition of acetic acid to plasma will be effective in the sterilization of plasma and killing of bacteria in wounds and burns.

  10. 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.

  11. 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

  12. 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.

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

    PubMed

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

    2015-09-24

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

  14. 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

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

    PubMed

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

    2008-07-01

    The UICC requires investigation of a minimum of 12 lymph nodes for adequate lymph node staging in colorectal cancer. Despite that, many authors recommend investigation of a larger number, and different techniques, such as fat clearance, have therefore been developed. In this study we introduce a novel technique involving ex vivo lymph node staining with intraarterial methylene blue injection in colon cancer. We compared 14 cases in which methylene injection was used with 14 cases from our records in which conventional investigation techniques were applied. The lymph node harvest differed highly significantly (p<0.001) between the two groups, with average numbers of 28+/-7 and 14+/-3 in the methylene blue group and the unstained group, respectively. The largest difference occurred in the size group 2-4 mm (191 vs 70 lymph nodes). In 6 cases in the unstained group additional embedding of fatty tissue was necessary to reach an adequate number of investigated lymph nodes. Methylene blue injection is a novel and highly effective method that will improve lymph node preparation in colorectal cancer.

  16. 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

  17. 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

  18. Enhancement of the thermostability of Hydrogenobacter thermophilus cytochrome c(552) through introduction of an extra methylene group into its hydrophobic protein interior.

    PubMed

    Tai, Hulin; Irie, Kiyofumi; Mikami, Shin-ichi; Yamamoto, Yasuhiko

    2011-04-19

    Careful scrutiny of the protein interior of Hydrogenobacter thermophilus cytochrome c(552) (HT) on the basis of its X-ray structure [Travaglini-Allocatelli, C., Gianni, S., Dubey, V. K., Borgia, A., Di Matteo, A., Bonivento, D., Cutruzzola, F., Bren, K. L., and Brunori, M. (2005) J. Biol. Chem. 280, 25729-25734] indicated that a void space, which is large enough to accommodate a methyl group, exists in the hydrophobic protein interior near the heme. We tried to reduce the void space through the replacement of a Val by Ile or Leu (Val/Ile or Val/Leu mutation), and then the structural and functional consequences of these two mutations were characterized in order to elucidate the relationship between the nature of the packing of hydrophobic residues and the functional properties of the protein. The study demonstrated striking differences in the structural and functional consequences between the two mutations. The Val/Ile mutation was found to cause further enhancement of the thermostability of the oxidized HT, as reflected in the increase of the denaturation temperature (T(m)) value by ∼ 3 deg, whereas the thermostability of the reduced form was essentially unaffected. As a result, the redox potential (E(m)) of the Val/Ile mutant exhibited a negative shift of ∼ 50 mV relative to that of the wild-type protein in an enthalpic manner, this being consistent with our previous finding that a protein with higher stability in its oxidized form exhibits a lower E(m) value [Terui, N., Tachiiri, N., Matsuo, H., Hasegawa, J., Uchiyama, S., Kobayashi, Y., Igarashi, Y., Sambongi, Y., and Yamamoto, Y. (2003) J. Am. Chem. Soc. 125, 13650-13651]. In contrast, the Val/Leu mutation led to a decrease in thermostability of both the redox forms of the protein, as reflected in the decreases of the T(m) values of the oxidized and reduced proteins by ∼ 3 and ∼ 5 deg, respectively, and the E(m) value of the Val/Leu mutant happened to be similar to that of the Val/Ile one. The E

  19. 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.

  20. 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

  1. 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

  2. Catalytic enantioselective 1,6-conjugate additions of propargyl and allyl groups

    NASA Astrophysics Data System (ADS)

    Meng, Fanke; Li, Xiben; Torker, Sebastian; Shi, Ying; Shen, Xiao; Hoveyda, Amir H.

    2016-09-01

    Conjugate (or 1,4-) additions of carbanionic species to α,β-unsaturated carbonyl compounds are vital to research in organic and medicinal chemistry, and there are several chiral catalysts that facilitate the catalytic enantioselective additions of nucleophiles to enoates. Nonetheless, catalytic enantioselective 1,6-conjugate additions are uncommon, and ones that incorporate readily functionalizable moieties, such as propargyl or allyl groups, into acyclic α,β,γ,δ-doubly unsaturated acceptors are unknown. Chemical transformations that could generate a new bond at the C6 position of a dienoate are particularly desirable because the resulting products could then be subjected to further modifications. However, such reactions, especially when dienoates contain two equally substituted olefins, are scarce and are confined to reactions promoted by a phosphine-copper catalyst (with an alkyl Grignard reagent, dialkylzinc or trialkylaluminium compounds), a diene-iridium catalyst (with arylboroxines), or a bisphosphine-cobalt catalyst (with monosilyl-acetylenes). 1,6-Conjugate additions are otherwise limited to substrates where there is full substitution at the C4 position. It is unclear why certain catalysts favour bond formation at C6, and—although there are a small number of catalytic enantioselective conjugate allyl additions—related 1,6-additions and processes involving a propargyl unit are non-existent. Here we show that an easily accessible organocopper catalyst can promote 1,6-conjugate additions of propargyl and 2-boryl-substituted allyl groups to acyclic dienoates with high selectivity. A commercially available allenyl-boron compound or a monosubstituted allene may be used. Products can be obtained in up to 83 per cent yield, >98:2 diastereomeric ratio (for allyl additions) and 99:1 enantiomeric ratio. We elucidate the mechanistic details, including the origins of high site selectivity (1,6- versus 1,4-) and enantioselectivity as a function of the catalyst

  3. 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.

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

    PubMed Central

    Albuquerque, Agnes Afrodite S.; Margarido, Edson A.; Menardi, Antonio Carlos; Scorzoni Filho, Adilson; Celotto, Andrea Carla; Rodrigues, Alfredo J.; Vicente, Walter Vilella A.; Evora, Paulo Roberto B.

    2016-01-01

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

  5. 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

  6. Counterintuitive mechanisms of the addition of hydrogen and simple olefins to heavy group 13 alkene analogues.

    PubMed

    Caputo, Christine A; Koivistoinen, Juha; Moilanen, Jani; Boynton, Jessica N; Tuononen, Heikki M; Power, Philip P

    2013-02-01

    The mechanism of the reaction of olefins and hydrogen with dimetallenes ArMMAr (Ar = aromatic group; M = Al or Ga) was studied by density functional theory calculations and experimental methods. The digallenes, for which the most experimental data are available, are extensively dissociated to gallanediyl monomers, :GaAr, in hydrocarbon solution, but the calculations and experimental data showed also that they react with simple olefins, such as ethylene, as intact ArGaGaAr dimers via stepwise [2 + 2 + 2] cycloadditions due to their considerably lower activation barriers vis-à-vis the gallanediyl monomers, :GaAr. This pathway was preferred over the [2 + 2] cycloaddition of olefin to monomeric :GaAr to form a gallacyclopropane ring with subsequent dimerization to yield the 1,2-digallacyclobutane intermediate and, subsequently, the 1,4-digallacyclohexane product. The calculations showed also that the addition of H(2) to digallene proceeds by a different mechanism involving the initial addition of one equivalent of H(2) to form a 1,2-dihydride intermediate. This reacts with a second equivalent of H(2) to give two ArGaH(2) fragments which recombine to give the observed product with terminal and bridging H-atoms, Ar(H)Ga(μ-H)(2)Ga(H)Ar. The computations agree with the experimental observation that the :GaAr(iPr(8)) (Ar(iPr(8)) = C(6)H-2,6-(C(6)H(3)-2,4,6-(i)Pr(3))(2)-3,5-(i)Pr(2)), which does not associate even in the solid state, does not react with ethylene or hydrogen. Calculations on the reaction of propene with ArAlAlAr show that, in contrast to the digallenes, addition involves an open-shell transition state consistent with the higher singlet diradical character of dialuminenes.

  7. 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

  8. Insecticidal Activity of α-Methylene-γ-butyrolactone against Several Insect Pests.

    PubMed

    Datta, P K; Kim, C S; Hara, T; Itoh, E; Horiike, M

    1999-01-01

    α-Methylene-γ-butyrolactone (tulipalin A), which has been found to possess effective insecticidal activity against Thrips palmi (Thysanoptera; Thripinae), was examined on several insect pests. This compound caused high mortality against thrips species such as Frankliniella occidentallis and Frankliniella intonsa. In addition, some mortality was observed against other agricultural pest species. It is considered that α-methylene-γ-butyrolactone has a wide spectrum of insecticidal activity.

  9. Polymers bearing groups derived from n-substituted lactams and their use as lubricating oil additives

    SciTech Connect

    Brulet, D.; Chauvel, B.; Pocheville, R.

    1980-09-16

    Novel lubricating oil polymer additives are obtained by the following: (1) by preparing, by anionic polymerization, a living diene polymer of mn of between about 20,000 and 300,000; (2) by functionalizing the said polymer by means of an nsubstituted lactam of the type of n-alkylcaprolactam, nbinylcaprolactam, and particularly of the type of nalkylpyrrolidione and n-vinylpyrrolidone; and (3) by hydrogenating the said functionalized polymer. A variant method of preparing the said polymers comprises subjecting the living polymer to a metalation operation before functionalization; the hydrogenation operation is carried out before metalation or after functionalization. The said polymers may be used as additives which improve the viscosity index and the dispersing power of lubricating oils. The amount of additive added is between about 0.1 and 10 percent by weight.

  10. 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…

  11. 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

  12. Three Additional Candidates for the Group of Very Wide Binary Asteroids

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.

    2016-10-01

    The very wide binary asteroids (VWBA) are a subgroup of binary asteroids that exhibit very long primary periods and, mostly, short secondary periods that are similar to those of the primary of "normal" small binary asteroids. It is unlikely that confirming mutual events will be seen by photometric observations, mostly because the orbital periods of the assumed satellites will be on the order of days. This paper introduces three additional candidates for this subgroup: (215442) 2002 MQ3, 2009 EC, and 2016 BU13. All three are considered to be among the more convincing examples that such systems exist.

  13. Heat tolerant fungi and applied research: Addition to the previously treated group of strictly thermotolerant species.

    PubMed

    Mouchacca, Jean

    2007-12-01

    Heat tolerant fungi are organisms that may perform bioconversion processes and produce industrially important metabolites. They may either be obligate thermophiles or simple thermotolerants. The present document is the continuation of a critical note on thermotolerant fungi erroneously reported in the literature as possessing thermophilic attributes. Fifty strictly thermotolerant taxa are here considered. Some of their binomials have only recently been introduced in the scientific literature. The reported thermotolerant species are grouped according to broad taxonomic categories. The nomenclature of zygomycetous taxa and anamorphic fungi is straightforward, as usually only one binomial is available or only one state is produced in culture respectively. For Ascomycetes regularly producing in culture a conidial state, the name of the sexual state (teleomorph) should be used to designate the organism even when a binomial is available for the anamorph; this prevents the practice of interchangeably using the name of either states of the same fungus. When ascomycetous taxa produce the anamorph regularly and the teleomorph only under specific cultural conditions, the name of the anamorph could be preferentially selected. The goal is to introduce uniformity in name citations of fungi, particularly in the literature of applied research. Each species is reported under its taxonomically correct name, either the original binomial or the latest combined binomial after generic transfer(s). Known synonyms are also specified. Maximum efforts were undertaken to trace updated information on the taxonomic position of these fifty strict thermotolerant species. For each, information on the type material, morphological features distinguishing it from related members of the genus (and when necessary a generic taxonomic assessment) and, finally, salient ecological features including heat tolerance levels are given. For some information on their biotechnological use is also provided

  14. 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

    2016-03-29

    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.

  15. 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

  16. Addition of ethylene or hydrogen to a main-group metal cluster under mild conditions.

    PubMed

    Vasko, Petra; Wang, Shuai; Tuononen, Heikki M; Power, Philip P

    2015-03-16

    Reaction of the tin cluster Sn8(Ar(Me6))4(Ar(Me6)=C6H2-2,6-(C6H3-2,4,6-Me3)2) with excess ethylene or dihydrogen at 25 °C/1 atmosphere yielded two new clusters that incorporated ethylene or hydrogen. The reaction with ethylene yielded Sn4(Ar(Me6))4(C2H2)5 that contained five ethylene moieties bridging four aryl substituted tin atoms and one tin-tin bond. Reaction with H2 produced a cyclic tin species of formula (Sn(H)Ar(Me6))4, which could also be synthesized by the reaction of {(Ar(Me6))Sn(μ-Cl)}2 with DIBAL-H. These reactions represent the first instances of direct reactions of isolable main-group clusters with ethylene or hydrogen under mild conditions. The products were characterized in the solid state by X-ray diffraction and IR spectroscopy and in solution by multinuclear NMR and UV/Vis spectroscopies. Density functional theory calculations were performed to explain the reactivity of the cluster.

  17. 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

  18. 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

  19. Synthesis of Heterocycles Through Classical Ugi and Passerini Reactions Followed by Secondary Transformations Involving One or Two Additional Functional Groups

    NASA Astrophysics Data System (ADS)

    Banfi, Luca; Basso, Andrea; Riva, Renata

    The combination of classical isocyanide-based multicomponent reactions (Ugi and Passerini) with a variety of post-condensation transformations, which take advantage of suitably positioned additional functional groups, allows the straightforward synthesis, often in 1-2 synthetic steps, of many diverse nitrogen-containing heterocycles. This review will cover all the applications of this strategy reported to date (September 2009).

  20. Enhancing First-Grade Students' Addition-Fact Fluency Using Classwide Cover, Copy, and Compare, a Sprint, and Group Rewards

    ERIC Educational Resources Information Center

    Poncy, Brian C.; Skinner, Christopher H.

    2011-01-01

    The authors used a multiple-probe, across-tasks design to evaluate the effects of a classwide, multicomponent intervention on first-grade students' addition-fact fluency. Intervention components included "cover, copy, and compare," a 2-min math sprint, and a weekly group reward. Results showed that classwide digits correct per minute averages…

  1. Adsorption thermodynamics of Methylene Blue onto bentonite.

    PubMed

    Hong, Song; Wen, Cheng; He, Jing; Gan, Fuxing; Ho, Yuh-Shan

    2009-08-15

    The effect of temperature on the equilibrium adsorption of Methylene Blue dye from aqueous solution using bentonite was investigated. The equilibrium adsorption data were analyzed using three widely applied isotherms: Langmuir, Freundlich, and Redlich-Peterson. A non-linear method was used for comparing the best fit of the isotherms. Best fit was found to be Redlich-Peterson isotherm. Thermodynamic parameters, such as DeltaG degrees, DeltaH degrees, and DeltaS degrees were calculated using adsorption equilibrium constant obtained from the Langmuir isotherm. Results suggested that the Methylene Blue adsorption on bentonite was a spontaneous and endothermic process.

  2. Severe anaphylactic shock with methylene blue instillation.

    PubMed

    Dewachter, Pascale; Mouton-Faivre, Claudie; Tréchot, Philippe; Lleu, Jean-Claude; Mertes, Paul Michel

    2005-07-01

    We report a documented severe immunoglobulin E-mediated hypersensitivity reaction associated with use of 1% methylene blue for detection of tubal permeability occurring during general anesthesia. Clinical symptoms, biological assessment results, and cutaneous test positivity confirmed an anaphylactic reaction to methylene blue. This case report confirms the need for systematic allergological investigation of all drugs and substances administered during the perioperative period in the event of a hypersensitivity reaction occurring during anesthesia. Anesthesiologists should be aware of the possibility of hypersensitivity reactions involving any drug or substance used during surgery.

  3. Carboxylic Acids as A Traceless Activation Group for Conjugate Additions: A Three-Step Synthesis of (±)-Pregabalin

    PubMed Central

    2015-01-01

    The direct application of carboxylic acids as a traceless activation group for radical Michael additions has been accomplished via visible light-mediated photoredox catalysis. Photon-induced oxidation of a broad series of carboxylic acids, including hydrocarbon-substituted, α-oxy, and α-amino acids, provides a versatile CO2-extrusion platform to generate Michael donors without the requirement for organometallic activation or propagation. A diverse array of Michael acceptors is amenable to this new conjugate addition strategy. An application of this technology to a three-step synthesis of the medicinal agent pregabalin (commercialized by Pfizer under the trade name Lyrica) is also presented. PMID:25032785

  4. Methylene Blue Causing Serotonin Syndrome Following Cystocele Repair.

    PubMed

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

    2016-11-01

    Methylene blue is an intravenously administered agent that may potentiate serotonin syndrome. The usage of methylene blue to evaluate ureters for injuries and patency during urological surgeries is recognized as common practice. However, there is no mention of serotonin syndrome caused by methylene blue in urological literature or for urological surgery. We report the first urological case in order to raise awareness of the risk for serotonin toxicity with utilizing methylene blue. PMID:27617215

  5. Number of Oxidations Relative to Methylene.

    ERIC Educational Resources Information Center

    Kjonaas, Richard A.

    1986-01-01

    Describes a new way of quantifying organic oxidation-reduction reactions that extends the traditional method of assigning oxidation numbers by replacing them with NORM's (Number of Oxidations Relative to Methylene). This modification allows the system to be applied to more complex examples without the cumbersomeness inherent in the original…

  6. 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.

  7. A quantum chemical study of the mechanisms of olefin addition to group 9 transition metal dioxo compounds.

    PubMed

    Ahmed, Issahaku; Tia, Richard; Adei, Evans

    2016-01-01

    triplet PES than on the singlet PES for the formation of similar analogues. There are fewer competitive reaction pathways on the triplet surface than on the singlet PES. Also, cycloadditions that seem impossible on the singlet PES seem possible on the doublet and or triplet PESs, this is the case typically for the Rh and Co complexes, illustrating the importance of multiple spin states in organometallic reactions.Graphical AbstractTable of Contents Synopsis: A study of the mechanism of ethylene addition to MO2(CH2)(CH3)(M=Co,Rh,Ir) shows the reactions of the Co complex have lower activation barriers for the preferred [3+2] and [2+2] addition pathways and fewer side reactions than those of Rh and Ir. Reactions are more feasible and selective on the triplet PES than on the singlet PES. These illustrate the importance of multiple spin states in organometallic reactions and shows catalyst activity and selectivity decreases down the group.

  8. 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...

  9. 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…

  10. Use of TOF-SIMS to study adsorption and loading behavior of methylene blue and papain in a nano-porous silicon layer.

    PubMed

    Kempson, Ivan M; Barnes, Timothy J; Prestidge, Clive A

    2010-02-01

    TOF-SIMS was applied to study the cross-sectional distribution of methylene blue and papain in porous silicon layers. Elemental and molecular information were used to study their distributions in the porous region and the chemistry of their adsorption. Methylene blue (MW = 284 Da) penetrated to the base to the pores. Positive ions (SiCH(3)(+)) suggest methylene blue binds to the substrate via its methyl groups. Negative fragments (SiOSH(3)(-) and SiO(2)SCH(-)) also suggested chemisorption via O bridging of the substrate Si and methylene blue S. The larger Papain molecule (23,406 Da) distributed itself in a similar manner to methylene blue demonstrating larger molecules can be effectively incorporated into such pore structures.

  11. 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.

  12. 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…

  13. 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.

  14. 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

  15. 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…

  16. 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

  17. Solvation free energy of the peptide group: its model dependence and implications for the additive-transfer free-energy model of protein stability.

    PubMed

    Tomar, Dheeraj S; Asthagiri, D; Weber, Valéry

    2013-09-17

    The group-additive decomposition of the unfolding free energy of a protein in an osmolyte solution relative to that in water poses a fundamental paradox: whereas the decomposition describes the experimental results rather well, theory suggests that a group-additive decomposition of free energies is, in general, not valid. In a step toward resolving this paradox, here we study the peptide-group transfer free energy. We calculate the vacuum-to-solvent (solvation) free energies of (Gly)n and cyclic diglycine (cGG) and analyze the data according to experimental protocol. The solvation free energies of (Gly)n are linear in n, suggesting group additivity. However, the slope interpreted as the free energy of a peptide unit differs from that for cGG scaled by a factor of half, emphasizing the context dependence of solvation. However, the water-to-osmolyte transfer free energies of the peptide unit are relatively independent of the peptide model, as observed experimentally. To understand these observations, a way to assess the contribution to the solvation free energy of solvent-mediated correlation between distinct groups is developed. We show that linearity of solvation free energy with n is a consequence of uniformity of the correlation contributions, with apparent group-additive behavior in the water-to-osmolyte transfer arising due to their cancellation. Implications for inferring molecular mechanisms of solvent effects on protein stability on the basis of the group-additive transfer model are suggested.

  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. 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.

  1. SUV measurement of normal vertebrae using SPECT/CT with Tc-99m methylene diphosphonate

    PubMed Central

    Kaneta, Tomohiro; Ogawa, Matsuyoshi; Daisaki, Hiromitsu; Nawata, Shintaro; Yoshida, Keisuke; Inoue, Tomio

    2016-01-01

    The purpose of this study is to perform quantitative measurement based on the standardized uptake value (SUV) of the uptake of Tc-99m methylene diphosphonate (MDP) in the normal vertebrae using a single photon emission tomography (SPECT)/computed tomography (CT) scanner. A retrospective study of patients with cancer or joint disorders was performed. We acquired data for a group of 29 patients (8 women and 21 men; mean age, 68.2 ± 6.7 years; age range, 44-87 years) undergoing bone SPECT/CT scans with Tc-99m MDP between September and October 2015. Various SUVs were calculated based on body-weight, lean-body-weight (lbw), Japanese lean-body-weight (jlbw) and Japanese bone-mineral-content (jbmc). SUVs of normal vertebrae showed a wide range of values. Among these, the maximum body-weight based SUV showed the lowest coefficient of variation. The SUVs also showed relatively small intra-subject variability. In addition, all SUVs showed moderate and significant correlation with height. Moreover, lbw-, jlbw-, and jbmc-based SUVs of men were significantly higher than those of women. In conclusions, SUVs of normal vertebrae showed a relatively large inter-individual variability and small intra-individual variability. As a quantitative imaging biomarker, SUVs might require standardization with adequate reference data for the same subject to minimize variability. PMID:27766184

  2. Prophylaxis and reversal of ifosfamide encephalopathy with methylene-blue.

    PubMed

    Küpfer, A; Aeschlimann, C; Wermuth, B; Cerny, T

    1994-03-26

    The antineoplastic ifosfamide produces dose-dependent signs of neurotoxicity. After ifosfamide overdose in a patient, we found excessive urinary excretion of glutaric acid and sarcosine, which is compatible with glutaric aciduria type II, a defect in mitochondrial fatty acid oxidation that results from defective electron transfer to flavoproteins. We therefore used the electron-accepting drug methylene-blue as an antidote for ifosfamide encephalopathy. In one patient, ifosfamide neurotoxicity was rapidly reversed by methylene-blue 50 mg intravenously. In another patient with previous episodes of ifosfamide encephalopathy, methylene-blue was administered orally prophylactically. No symptoms of neurotoxicity were noted.

  3. [Decomposition of hemoglobin UV absorption spectrum into absorption spectra of prosthetic group and apoprotein by means of an additive model].

    PubMed

    Lavrinenko, I A; Vashanov, G A; Artyukhov, V G

    2015-01-01

    The decomposition pathways of hemoglobin UV absorption spectrum into the absorption spectra of the protein and non-protein components are proposed and substantiated by means of an additive model. We have established that the heme component has an absorption band with a maximum at λ(max) = 269.2 nm (ε = 97163) and the apoprotein component has an absorption band with a maximum at λ(max) = 278.4 nm (ε = 48669) for the wavelength range from 240.0 to 320.0 nm. An integral relative proportion of absorption for the heme fraction (78.8%) and apoprotein (21.2%) in the investigating wavelength range is defined.

  4. Additional borehole geophysical logging at Waste Area Grouping 1 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Not Available

    1994-07-01

    This technical memorandum describes the borehole geophysical logging performed at selected coreholes at Waste Area Grouping 1 between March and November 1991 in support of the remedial investigation. The primary objectives of the borehole geophysical logging program were to (1) identify fractured bedrock zones and identify those fractured bedrock zones participating in active groundwater flow, (2) correlate the fractured intervals with the regional stratigraphy described, and (3) further characterize local bedrock geology and hydrogeology and gain insight about the bedrock aquifer flow system. A secondary objective was to provide stratigraphic correlations with existing logs for coreholes CH001 through CH005. Fractured bedrock zones and active or open fractures were identified in all coreholes logged. The fracture identification and analysis process was intended to distinguish between open or active fractures participating in active groundwater flow and closed or inactive fractures that are partially or completely filled (such as with calcite mineralization) and do not support groundwater circulation. Most of the fractures identified are bedding plane. Fracture occurrence varies with the different units of the Chickamauga Group; the greatest density of fractures and active fractures occurs in the upper 150 ft of stratum cored. Fractures actively contributing to groundwater flow were also identified, and direction of fluid movement within fractures was identified for those coreholes with flowmeter data.

  5. 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

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

    PubMed

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

    2014-02-15

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

  7. Thoracoscopic resection with intraoperative use of methylene blue to localize mediastinal parathyroid adenomas.

    PubMed

    Adachi, Yoshin; Nakamura, Hiroshige; Taniguchi, Yuji; Miwa, Ken; Fujioka, Shinji; Haruki, Tomohiro

    2012-03-01

    We report a case of thoracoscopic resection of mediastinal parathyroid adenomas using methylene blue to localize the tumors during the operation. After methylene blue 4 mg/kg was injected intravenously, we easily identified methylene blue-stained parathyroid glands and successfully resected them with sufficient surgical margins. The use of methylene blue for detection of parathyroid adenoma is a useful technique.

  8. [Study on the inclusion behavior of cucurbit [7] uril with methylene blue by spectrofluorometric titrations].

    PubMed

    Yu, Hua-peng; Sun, Jun-yong; Wu, Lian; Xu, Hong-wei; Wang, Lun; Zhou, Yun-you

    2009-04-01

    The characteristics of host-guest complexation between cucurbit [7] uril (CB7) and methylene blue (MB) were investigated by fluorescence spectrometry in acetate buffer solution at room temperature. It was found that the fluorescence intensity of methylene blue regularly increased upon the addition of cucurbit [7] uril accompanying with a blue-shift of the position of the emission maximum. The results indicate the formation of complex between CB7 and MB at a 1 : 1 complex stoichiometry and the association constant was calculated by applying a deduced equation. 1H NMR spectra were applied to to complement the fluorescence work to verify the formation of the complex. From the temperature dependence of the equilibrium constants, thermodynamics parametersH andS values were obtained, indicating an enthalpic driving force for complexation. The possible interaction mechanism was also discussed. This work may extend the application range of cucurbit [7] uril in biochemistry and pharmaceutical analysis.

  9. 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)

  10. 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

  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.

  12. 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

  13. Treatment of methylene-induced carbon monoxide poisoning with hyperbaric oxygenation. Final report

    SciTech Connect

    Rudge, F.W.

    1989-01-01

    Methylene chloride is an organic solvent with many industrial uses. Inhalation of methylene chloride fumes can result in toxicity, caused by hepatic biotransformation of methylene chloride to carbon monoxide. A case of acute methylene chloride poisoning is presented, including successful treatment of this patient with the use of hyperbaric oxygenation. The rationale for the use of hyperbaric oxygenation in the treatment of methylene chloride poisoning is discussed. (aw)

  14. Phosphazene additives

    DOEpatents

    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.

  15. 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.

  16. Simultaneous multiselective spectroelectrochemical fiber-optic sensor: demonstration of the concept using methylene blue and ferrocyanide.

    PubMed

    Imai, Kenichiro; Okazaki, Takuya; Hata, Noriko; Taguchi, Shigeru; Sugawara, Kazuharu; Kuramitz, Hideki

    2015-02-17

    Herein, we present a novel spectroelectrochemical fiber-optic sensor that combines electrochemistry, spectroscopy, and electrostatic adsorption in three modes of selectivity. The proposed sensor is simple and consists of a gold mesh cover on a multimode fiber optic that uses attenuated total reflection as the optical detection mode. The sensing is based on changes in the attenuation of the light that passes through the fiber-optic core accompanying the electrochemical oxidation-reduction of an analyte at the electrode. Methylene blue and ferrocyanide were used as model analytes to evaluate the performance of the proposed sensor. The optical transmission changes generated by electrochemical manipulation showed a good linear relationship with the concentration and the limits of detection (3σ) for methylene blue and ferrocyanide at 2.0 × 10(-7) and 1.6 × 10(-3) M, respectively. The sensor responses were successfully enhanced with an additional level of selectivity via an electrostatically adsorbed, self-assembled monolayer (SAM), which consisted of a silane coupling layer, a polyanion, and a polycation. The improvement observed in the sensitivity of a SAM-modified fiber-optic sensor was rather encouraging. The optimized sensor had detection limits (3σ) of 8.3 × 10(-9) M for methylene blue and 7.1 × 10(-4) M for ferrocyanide. The developed sensor was successfully applied to the detection of ferrocyanide in simulated nuclear waste.

  17. 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.

  18. A Multifaceted Directing Group Switching Ynones as Michael Donors in Chemo-, Enantio-, and γ-Selective 1,4-Conjugate Additions with Nitroolefins.

    PubMed

    Liu, Weiwei; Zou, Liwei; Fu, Binbin; Wang, Xinran; Wang, Ke; Sun, Zhongwen; Peng, Fangzhi; Wang, Wei; Shao, Zhihui

    2016-09-16

    α,β-Unsaturated ynones have historically been used as Michael acceptors in conjugate addition reactions. Herein, we have demonstrated for the first time that ynones can be harnessed as Michael donors for use in catalytic asymmetric conjugate addition reactions by strategically introducing a CO2t-Bu group as a multitasking directing group. Furthermore, this concept has enabled designer ynones as versatile synthetic equivalents of both α' anions of ynones and γ monoanions of 1,3-diketones, which are synthetically valued but difficult to generate. The first catalytic enantioselective conjugate addition of ynones as Michael donors has been realized in good yields with high enantioselectivities. A unified approach to regiospecifically and chemo- and enantioselectively access hitherto elusive γ-Michael adducts of 1,3-diketones has been achieved in a divergent manner. The strategy described here by exploring new reactivity and creating new reagents holds great potential applications in other still unsolved transformations. PMID:27571411

  19. A Multifaceted Directing Group Switching Ynones as Michael Donors in Chemo-, Enantio-, and γ-Selective 1,4-Conjugate Additions with Nitroolefins.

    PubMed

    Liu, Weiwei; Zou, Liwei; Fu, Binbin; Wang, Xinran; Wang, Ke; Sun, Zhongwen; Peng, Fangzhi; Wang, Wei; Shao, Zhihui

    2016-09-16

    α,β-Unsaturated ynones have historically been used as Michael acceptors in conjugate addition reactions. Herein, we have demonstrated for the first time that ynones can be harnessed as Michael donors for use in catalytic asymmetric conjugate addition reactions by strategically introducing a CO2t-Bu group as a multitasking directing group. Furthermore, this concept has enabled designer ynones as versatile synthetic equivalents of both α' anions of ynones and γ monoanions of 1,3-diketones, which are synthetically valued but difficult to generate. The first catalytic enantioselective conjugate addition of ynones as Michael donors has been realized in good yields with high enantioselectivities. A unified approach to regiospecifically and chemo- and enantioselectively access hitherto elusive γ-Michael adducts of 1,3-diketones has been achieved in a divergent manner. The strategy described here by exploring new reactivity and creating new reagents holds great potential applications in other still unsolved transformations.

  20. 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

  1. Neuroprotective and Functional Improvement Effects of Methylene Blue in Global Cerebral Ischemia.

    PubMed

    Lu, Qing; Tucker, Donovan; Dong, Yan; Zhao, Ningjun; Zhang, Quanguang

    2016-10-01

    Transient global cerebral ischemia (GCI) causes delayed neuronal cell death in the vulnerable hippocampus CA1 subfield, as well as behavioral deficits. Ischemia reperfusion (I/R) produces excessive reactive oxygen species and plays a key role in brain injury. The mitochondrial electron respiratory chain is the main cellular source of free radical generation, and dysfunction of mitochondria has a significant impact on the neuronal cell death in ischemic brain. The aim of the present study is to investigate the potential beneficial effects of methylene blue (MB) in a four-vessel occlusion (4VO) GCI model on adult male rats. MB was delivered at a dose of 0.5 mg/kg/day for 7 days, through a mini-pump implanted subcutaneously after GCI. We first found that MB significantly improved ischemic neuronal survival in the hippocampal CA1 region as measured by cresyl violet staining as well as NeuN staining. We also found that MB has the ability to rescue ischemia-induced decreases of cytochrome c oxidase activity and ATP generation in the CA1 region following I/R. Further analysis with labeling of MitoTracker® Red revealed that the depolarization of mitochondrial membrane potential (MMP) was markedly attenuated following MB treatment. In addition, the induction of caspase-3, caspase-8, and caspase-9 activities and the increased numbers of TUNEL-positive cells of the CA1 region were significantly reduced by MB application. Correspondingly, Barnes maze tests showed that the deterioration of spatial learning and memory performance following GCI was significantly improved in the MB-treatment group compared to the ischemic control group. In summary, our study suggests that MB may be a promising therapeutic agent targeting neuronal cell death and cognitive deficits following transient global cerebral ischemia.

  2. Treatment and toxicity evaluation of methylene blue using electrochemical oxidation, fly ash adsorption and combined electrochemical oxidation-fly ash adsorption.

    PubMed

    Wang, Kai-sung; Wei, Ming-Chi; Peng, Tzu-Huan; Li, Heng-Ching; Chao, Shu-Ju; Hsu, Tzu-Fang; Lee, Hong-Shen; Chang, Shih-Hsien

    2010-08-01

    Treatment of a basic dye, methylene blue, by electrochemical oxidation, fly ash adsorption, and combined electrochemical oxidation-fly ash adsorption was compared. Methylene blue at 100 mgL(-1) was used in this study. The toxicity was also monitored by the Vibrio fischeri light inhibition test. When electrochemical oxidation was used, 99% color and 84% COD were removed from the methylene blue solution in 20 min at a current density of 428 Am(-2), NaCl of 1000 mgL(-1), and pH(0) of 7. However, the decolorized solution showed high toxicity (100% light inhibition). For fly ash adsorption, a high dose of fly ash (>20,000 mgL(-1)) was needed to remove methylene blue, and the Freundlich isotherm described the adsorption behavior well. In the combined electrochemical oxidation-fly ash adsorption treatment, the addition of 4000 mgL(-1) fly ash effectively reduced intermediate toxicity and decreased the COD of the electrochemical oxidation-treated methylene blue solution. The results indicated that the combined process effectively removed color, COD, and intermediate toxicity of the methylene blue solution.

  3. Establishment of a series of alien monosomic addition lines of Japanese bunching onion (Allium fistulosum L.) with extra chromosomes from shallot (A. cepa L. aggregatum group).

    PubMed

    Shigyo, M; Tashiro, Y; Isshiki, S; Miyazaki, S

    1996-12-01

    Forty one plants of alien monosomic addition lines of Allium fistulosum L. with extra chromosomes from A. cepa L. Aggregatum group (FF + nA) were produced through the second backcross of amphidiploids between these two species to A. fistulosum. Identification of the extra chromosomes in the 16 plants by elaborate karyotype analyses indicate that a complete series (eight different types) of the alien monosomic addition lines was established in Allium for the first time in this study. Chromosomal locations of malate dehydrogenase (MDH) gene, triosephosphate isomerase (TPI) gene and 5S rDNA of A. cepa Aggregatum group were determined using the series; The gene locus Mdh-1 was located on 4A, Tpi-1 on 3A and a 5S rDNA locus on 7A. Our previous and present studies using the alien monosomic addition lines revealed 11 genetic markers (isozyme and 5S rDNA) assigned to all eight chromosomes of A. cepa Aggregatum group, and these markers reconfirmed the completion of the series. Extra chromosomes of 25 other plants were examined by means of simple analyses of the chromosome markers and karyotypes. Of the total 41 plants, frequencies of the alien monosomic addition lines with extra chromosomes 1A to 8A were as follows: 1A, 5 plants; 2A, 3; 3A, 5; 4A, 9; 5A, 4; 6A, 2; 7A, 11; and 8A, 2.

  4. Establishment of a series of alien monosomic addition lines of Japanese bunching onion (Allium fistulosum L.) with extra chromosomes from shallot (A. cepa L. aggregatum group).

    PubMed

    Shigyo, M; Tashiro, Y; Isshiki, S; Miyazaki, S

    1996-12-01

    Forty one plants of alien monosomic addition lines of Allium fistulosum L. with extra chromosomes from A. cepa L. Aggregatum group (FF + nA) were produced through the second backcross of amphidiploids between these two species to A. fistulosum. Identification of the extra chromosomes in the 16 plants by elaborate karyotype analyses indicate that a complete series (eight different types) of the alien monosomic addition lines was established in Allium for the first time in this study. Chromosomal locations of malate dehydrogenase (MDH) gene, triosephosphate isomerase (TPI) gene and 5S rDNA of A. cepa Aggregatum group were determined using the series; The gene locus Mdh-1 was located on 4A, Tpi-1 on 3A and a 5S rDNA locus on 7A. Our previous and present studies using the alien monosomic addition lines revealed 11 genetic markers (isozyme and 5S rDNA) assigned to all eight chromosomes of A. cepa Aggregatum group, and these markers reconfirmed the completion of the series. Extra chromosomes of 25 other plants were examined by means of simple analyses of the chromosome markers and karyotypes. Of the total 41 plants, frequencies of the alien monosomic addition lines with extra chromosomes 1A to 8A were as follows: 1A, 5 plants; 2A, 3; 3A, 5; 4A, 9; 5A, 4; 6A, 2; 7A, 11; and 8A, 2. PMID:9080683

  5. Group additivity values for estimating the enthalpy of formation of organic compounds: an update and reappraisal. 2. C, H, N, O, S, and halogens.

    PubMed

    Holmes, John L; Aubry, Christiane

    2012-07-01

    This study extends a previous publication on group additivity values (GAVs) for the elements C, H, and O, to include the elements nitrogen, sulfur, and the halogens. The present state and utility of the Benson additivity schemes for estimating the enthalpy of formation (Δ(f)H(0)) of organic compounds are again described, extending them to include more elements. Old and new GAVs for a wide variety of compounds are provided and are revised where necessary. When new terms are proposed, or old ones are significantly altered, the rationale for so doing is presented. GAV derived ring strain values for benzene and pyridine indicate that the aromatic stabilization of each is essentially the same. As before, the thermochemical consequences of replacing one functional group by another are also shown, thus permitting quick shortcuts to the estimation of new Δ(f)H(0) values.

  6. Adsorption of methylene blue from aqueous solution by graphene.

    PubMed

    Liu, Tonghao; Li, Yanhui; Du, Qiuju; Sun, Jiankun; Jiao, Yuqin; Yang, Guangming; Wang, Zonghua; Xia, Yanzhi; Zhang, Wei; Wang, Kunlin; Zhu, Hongwei; Wu, Dehai

    2012-02-01

    Graphene was prepared using a modified Hummers' method. The physico-chemical properties of graphene were characterized by TEM, BET specific surface area, FTIR, Raman and XRD measurements. The effect factors including pH, contact time, temperature and dosage on the adsorption properties of methylene blue onto graphene were investigated. The experimental data of isotherm followed the Langmuir isotherm model better than the Freundlich model. The maximum adsorption capacity obtained from Langmuir isotherm equation at 293 K was 153.85 mg/g, indicating graphene is a good adsorbent for the adsorption of MB. The kinetic study illustrated that the adsorption of methylene blue onto graphene fit the pseudo second-order model. The thermodynamic parameters indicated that the adsorption of methylene blue onto graphene was an endothermic and spontaneous process.

  7. 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

  8. A Helical Polyphenylacetylene Having Amino Alcohol Moieties Without Chiral Side Groups as a Chiral Ligand for the Asymmetric Addition of Diethylzinc to Benzaldehyde.

    PubMed

    Liu, Lijia; Long, Qing; Aoki, Toshiki; Zhang, Geng; Kaneko, Takashi; Teraguchi, Masahiro; Zhang, Chunhong; Wang, Yudan

    2015-08-01

    One-handed helical polyphenylacetylenes having achiral amino alcohol moieties, but no chiral side groups, were synthesized by the helix-sense-selective copolymerization of an achiral phenylacetylene having an amino alcohol side group with a phenylacetylene having two hydroxyl groups. Since the resulting helical copolymers were successfully utilized as chiral ligands for the enantioselective alkylation of benzaldehyde with diethylzinc, we can conclude that the main-chain chirality based on the one-handed helical conformation is useful for the chiral catalysis of an asymmetric reaction for the first time. The enantioselectivities of the reaction were controlled by the optical purities of the helical polymer ligands. In addition, the polymer ligands could be easily recovered by precipitation after the reaction.

  9. 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.

  10. 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

  11. 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

  12. 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

  13. 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

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

    Integrated Risk Information System (IRIS)

    TOXICOLOGICAL REVIEW of METHYLENE DIPHENYL DIISOCYANATE ( MDI ) ( CAS No . 101 - 68 - 8 and 9016 - 87 - 9 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) February 1998 U.S . ENVIRONMENTAL PROTECTION AGENCY WASHINGTON , DC TABLE OF CONTENTS TOXICOLOGICAL REVIEW

  15. 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

  16. 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…

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

    ERIC Educational Resources Information Center

    Snehalatha, K. C.; And Others

    1997-01-01

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

  18. Borax methylene blue: a spectroscopic and staining study.

    PubMed

    Donaldson, P T; Russo, A; Reynolds, C; Lillie, R D

    1978-07-01

    Borax methylene blue is quite stable at room temperatures of 22-25 C. At 30 C polychroming is slow; during 50 days in a water bath at this temperature the absorption peak moves from 665 to 656 nm. At 35 C, the absorption peak reaches 660 nm in 7 days, 654 nm in 14. At 60 C polychroming is rapid, the absorption peak reaching 640-620 nm in 3 days. When the pH of the borax methylene blue solutions, normally about 9.0, is adjusted to pH 6.5, the absorption peak remains at 665 nm even when incubated at 60 C for extended periods. When used as a blood stain 0.4 ml borax methylene blue (1% methylene blue in 1% borax), 4 ml acetone, 2 ml borax-acid phosphate buffer to bring the solution to pH 6.5, and distilled water to make 40 ml, with 0.2 ml 1% eosin added just before using, an excellent Nocht-Giemsa type stain is achieved after 30 minutes staining. The material plasmodia P. falciparum, P. vivax, and P. berghei stain moderate blue with dark red chromatin and green to black pigment granules. The study confirms Malachowski's 1891 results and explains Gautier's 1896-98 failure to duplicate it.

  19. Methylene blue solder re-absorption in microvascular anastomoses

    NASA Astrophysics Data System (ADS)

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

    2003-06-01

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

  20. 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.

  1. 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.

  2. Influence of additional load on the moments of the agonist and antagonist muscle groups at the knee joint during closed chain exercise.

    PubMed

    Rao, Guillaume; Amarantini, David; Berton, Eric

    2009-06-01

    The present study investigated the influence of additional loads on the knee net joint moment, flexor and extensor muscle group moments, and cocontraction index during a closed chain exercise. Loads of 8, 28, or 48 kg (i.e., respectively, 11.1+/-1.5%, 38.8+/-5.3%, and 66.4+/-9.0% of body mass) were added to subjects during dynamic half squats. The flexor and extensor muscular moments and the amount of cocontraction were estimated at the knee joint using an EMG-and-optimization model that includes kinematics, ground reaction, and EMG measurements as inputs. In general, our results showed a significant influence of the Load factor on the net knee joint moment, the extensor muscular moment, and the flexor muscle group moment (all Anova p<.05). Hence we confirmed an increase in muscle moments with increasing load and moreover, we also showed an original "more than proportional" evolution of the flexor and extensor muscle group moments relative to the knee net joint moment. An influence of the Phase (i.e., descent vs. ascent) factor was also seen, revealing different activation strategies from the central nervous system depending on the mode of contraction of the agonist muscle group. The results of the present work could find applications in clinical fields, especially for rehabilitation protocols.

  3. 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

  4. Mass transport in low Tg azo-polymers: Effect on the surface relief grating induction and stability of additional side chain groups able to generate physical interactions

    NASA Astrophysics Data System (ADS)

    Luca, Alina Raicu; Moleavin, Ioana-Andreea; Hurduc, Nicolae; Hamel, Matthieu; Rocha, Licinio

    2014-01-01

    The nanostructuration ability of low glass transition temperature (Tg) azo-polysiloxanes films is investigated at working temperatures close or higher than the film Tg. The behavior of materials incorporating additional side chain nitrobenzene or naphthalene groups and as a result presenting different Tg is compared in terms of the surface modulation dynamics and stability of the induced topographic modifications. This comparison is carried out under light exposure and in dark environment. We demonstrate the ability to optically generate surface modulations on these materials even at operating temperatures corresponding to the film Tg. Along with a modification of the opto-mechanic properties correlated with the materials chemical structure, a collapse of the surface structures occurring with different dynamics in materials of similar Tg is highlighted. These observations suggest the existence of an additional mechanism rather than a purely thermal redistribution of the polymer chains in the films.

  5. 21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Methylene blue-containing drugs for use in animals... Decisions § 500.27 Methylene blue-containing drugs for use in animals. (a) New information requires a re- evaluation of the status of drugs containing methylene blue (tetramethylthionine chloride) for oral use...

  6. 21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Methylene blue-containing drugs for use in animals... Decisions § 500.27 Methylene blue-containing drugs for use in animals. (a) New information requires a re- evaluation of the status of drugs containing methylene blue (tetramethylthionine chloride) for oral use...

  7. Methylene blue adsorption onto swede rape straw (Brassica napus L.) modified by tartaric acid: equilibrium, kinetic and adsorption mechanisms.

    PubMed

    Feng, Yanfang; Zhou, Hui; Liu, Guohua; Qiao, Jun; Wang, Jinhua; Lu, Haiying; Yang, Linzhang; Wu, Yonghong

    2012-12-01

    The aim of this study was to develop a promising and competitive bioadsorbent with the abundant of source, low price and environmentally friendly characters to remove cationic dye from wastewater. The swede rape straw (Brassica napus L.) modified by tartaric acid (SRSTA) was prepared, characterized and used to remove methylene blue (MB) from aqueous solution at varied operational conditions (including MB initial concentrations, adsorbent dose, etc.). Results demonstrated that the equilibrium data was well fitted by Langmuir isotherm model. The maximum MB adsorption capacity of SRSTA was 246.4 mg g(-1), which was comparable to the results of some previous studied activated carbons. The higher dye adsorption capacity could be attributed to the presence of more functional groups such as carboxyl group on the surface of SRSTA. The adsorption mechanism was also discussed. The results indicate that SRSTA is a promising and valuable absorbent to remove methylene blue from wastewater.

  8. 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

  9. 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.

  10. Production and characterization of alien chromosome additions in shallot (Allium cepa L. Aggregatum group) carrying extra chromosome(s) of Japanese bunching onion (A. fistulosum L.).

    PubMed

    Hang, Tran Thi Minh; Shigyo, Masayoshi; Yamauchi, Naoki; Tashiro, Yosuke

    2004-10-01

    First and second backcrosses of amphidiploid hybrids (2n = 4x = 32, genomes AAFF) between shallot (Allium cepa Aggregatum group) and A. fistulosum were conducted to produce A. cepa - A. fistulosum alien addition lines. When shallot (A. cepa Aggregatum group) was used as a pollinator, the amphidiploids and allotriploids set germinable BC(1) and BC(2) seeds, respectively. The 237 BC(1) plants mainly consisted of 170 allotriploids (2n = 3x = 24, AAF) and 42 hypo-allotriploids possessing 23 chromosomes, i.e., single-alien deletions (2n = 3x-1 = 23, AAF-nF). The single-alien deletions in the BC(1) progeny showed dwarfing characteristics and were discriminated from the allotriploids (2n = 24) and hyper-allotriploids (2n = 25) by means of flow cytometric analysis. The chromosome numbers of 46 BC(2) seedlings varied from 16 to 24. Eight monosomic additions (2n = 2x+1 = 17, AA+nF) and 20 single-alien deletions were found in these BC(2) seedlings. Consequently, six kinds of A. cepa - A. fistulosum alien chromosome additions possessing different chromosome numbers (2n = 17, 18, 20, 21, 22, 23) were recognized in the BC(1) and BC(2) populations. A total of 79 aneuploids, including 62 single-alien deletions, were analyzed by a chromosome 6F-specific isozyme marker (Got-2) in order to recognize its existence in their chromosome complements. This analysis revealed that two out of 62 single-alien deletions did not possess 6F. One (AAF-6F) out of the possible eight single-alien deletions could be identified at first. The present study is a first step toward the development of a useful tool, such as a complete set of eight different single-alien deletions, for the rapid chromosomal assignment of genes and genetic markers in A. fistulosum.

  11. Production and characterization of alien chromosome additions in shallot (Allium cepa L. Aggregatum group) carrying extra chromosome(s) of Japanese bunching onion (A. fistulosum L.).

    PubMed

    Hang, Tran Thi Minh; Shigyo, Masayoshi; Yamauchi, Naoki; Tashiro, Yosuke

    2004-10-01

    First and second backcrosses of amphidiploid hybrids (2n = 4x = 32, genomes AAFF) between shallot (Allium cepa Aggregatum group) and A. fistulosum were conducted to produce A. cepa - A. fistulosum alien addition lines. When shallot (A. cepa Aggregatum group) was used as a pollinator, the amphidiploids and allotriploids set germinable BC(1) and BC(2) seeds, respectively. The 237 BC(1) plants mainly consisted of 170 allotriploids (2n = 3x = 24, AAF) and 42 hypo-allotriploids possessing 23 chromosomes, i.e., single-alien deletions (2n = 3x-1 = 23, AAF-nF). The single-alien deletions in the BC(1) progeny showed dwarfing characteristics and were discriminated from the allotriploids (2n = 24) and hyper-allotriploids (2n = 25) by means of flow cytometric analysis. The chromosome numbers of 46 BC(2) seedlings varied from 16 to 24. Eight monosomic additions (2n = 2x+1 = 17, AA+nF) and 20 single-alien deletions were found in these BC(2) seedlings. Consequently, six kinds of A. cepa - A. fistulosum alien chromosome additions possessing different chromosome numbers (2n = 17, 18, 20, 21, 22, 23) were recognized in the BC(1) and BC(2) populations. A total of 79 aneuploids, including 62 single-alien deletions, were analyzed by a chromosome 6F-specific isozyme marker (Got-2) in order to recognize its existence in their chromosome complements. This analysis revealed that two out of 62 single-alien deletions did not possess 6F. One (AAF-6F) out of the possible eight single-alien deletions could be identified at first. The present study is a first step toward the development of a useful tool, such as a complete set of eight different single-alien deletions, for the rapid chromosomal assignment of genes and genetic markers in A. fistulosum. PMID:15599056

  12. (E)-3-chloro-N-((5-nitrothiophen-2-yl)methylene)aniline: a combined crystallographic, theoretical and antimicrobial activity investigation.

    PubMed

    Yılmaz, Işıl; Kazak, Canan; Gümüş, Sümeyye; Ağar, Erbil; Ardalı, Yüksel

    2012-11-01

    The title molecule, (E)-3-chloro-N-((5-nitrothiophen-2-yl)methylene)aniline, (C(11)H(7)ClN(2)O(2)S), was synthesized and characterized by IR and single-crystal X-ray structure determination. The compound crystallizes in the monoclinic space group P2(1)/c. In addition, the molecular geometry, vibrational frequencies and frontier molecular orbitals analysis of the title compound in the ground state have been calculated by using the PM3 semi-empirical, HF/6-31G(d) and B3LYP/6-31G(d) ab initio methods. The results of the optimized molecular structure are exhibited and compared with the experimental X-ray diffraction and the calculated results are show that the optimized geometry can well reproduce the crystal structure. The Schiff base compounds are very important in medicinal and pharmaceutical fields because of their wide spectrum of biological activities. Most of them show biological activities such as antimicrobial, antifungal as well as antitumor activity. Therefore, (C(11)H(7)ClN(2)O(2)S) was investigated for their antimicrobial activities, Gram-positive and Gram-negative bacteria.

  13. 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.

  14. 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

  15. 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

  16. 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

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

    PubMed

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

    2013-06-01

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

  18. Bipolar pulsed electrical discharge for decomposition of methylene blue in aqueous TiO2 nanoparticle dispersions.

    PubMed

    Kim, Byung Hoon; Kim, Sun-Jae; Chung, Minchul; Ahn, Ho-Geun; Lee, Heon; Park, Sung Hoon; Jung, Sang-Chul

    2013-03-01

    The objective of this paper is to investigate the decomposition process of organic pollutants by liquid phase plasma. A bipolar pulsed power supply was used to generate discharges in the aqueous TiO2 nanoparticle dispersions. The applied voltage, pulse width, and frequency were 250 V, 5 micros, and 30 kHz, respectively. Properties of generated plasma were investigated by electrical and optical emission spectroscopy methods. The comparison of properties of the discharge operated with and without oxygen gas bubbling is shown. The results of electrical-discharge degradation of methylene blue showed that the decomposition rate increased with the TiO2 particle dosages. Addition of oxygen gas bubbles also increased the degradation rate of methylene blue.

  19. 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.

  20. 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.

  1. Methylene blue injection into the rectal artery as a simple method to improve lymph node harvest in rectal cancer.

    PubMed

    Märkl, Bruno; Kerwel, Therese G; Wagner, Theodor; Anthuber, Matthias; Arnholdt, Hans M

    2007-07-01

    Adequate lymph node assessment in colorectal cancer is crucial for prognosis estimation and further therapy stratification. However, there is still an ongoing debate on required minimum lymph node numbers and the necessity of advanced techniques such as immunohistochemistry or PCR. It has been proven in several studies that lymph node harvest is often inadequate under routine analysis. Lymph nodes smaller than 5 mm are especially concerning as they can carry the majority of metastases. These small, but affected lymph nodes may escape detection in routine analysis. Therefore, fat-clearing protocols and sentinel techniques have been developed to improve accuracy of lymph node staging. We describe a novel and simple method of ex vivo methylene blue injection into the superior rectal artery of rectal cancer specimens, which highlights lymph nodes and makes them easy to detect during manual dissection. Initially, this method was developed for proving accuracy of total mesorectal excision. We performed a retrospective study comparing lymph node recovery of 12 methylene blue stained and an equal number of unstained cases. Lymph node recovery differed significantly with average lymph node numbers of 27+/-7 and 14+/-4 (P<0.001) for the methylene blue and the unstained group, respectively. The largest difference was found in size groups between 1 and 4 mm causing a shift in size distribution toward smaller nodes. Metastases were confirmed in 21 and 19 lymph nodes occurring in five and four cases, respectively. Hence, we conclude that methylene blue injection technique improves accuracy of lymph node staging by heightening the lymph node harvest in rectal resections. In our experience, it is a very simple time and cost effective method that can be easily established under routine circumstances.

  2. 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.

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

    PubMed

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

    2014-05-01

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

  4. 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.

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

    PubMed

    Loginov, Maksym; Lebovka, Nikolai; Vorobiev, Eugene

    2014-10-01

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

  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. 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

  8. [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.

  9. [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

  10. 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.

  11. 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

  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. A methylene blue-assisted technique for harvesting lymph nodes after radical surgery for gastric cancer: a prospective, randomized, controlled study.

    PubMed

    Aoyama, Toru; Fujikawa, Hirohito; Cho, Haruhiko; Ogata, Takashi; Shirai, Junya; Hayashi, Tsutomu; Rino, Yasushi; Masuda, Munetaka; Oba, Mari S; Morita, Satoshi; Yoshikawa, Takaki

    2015-02-01

    Harvesting lymph nodes (LNs) after gastrectomy is essential for accurate staging. This trial evaluated the efficiency and quality of a conventional method and a methylene blue-assisted method in a randomized manner. The key eligibility criteria were as follows: (i) histologically proven adenocarcinoma of the stomach; (ii) clinical stage I-III; (iii) R0 resection planned by gastrectomy with D1+ or D2 lymphadenectomy. The primary endpoint was the ratio of the pathologic number of harvested LNs per time (minutes) as an efficacy measure. The secondary endpoint was the number of harvested LNs, as a quality measure. Between August 2012 and December 2012, 60 patients were assigned to undergo treatment using the conventional method (n=29) and the methylene blue dye method (n=31). The baseline demographics were mostly well balanced between the 2 groups. The number of harvested LNs (mean±SD) was 33.6±11.9 in the conventional arm and 43.4±13.9 in the methylene blue arm (P=0.005). The ratio of the number of the harvested LNs per time was 1.12±0.46 LNs/min in the conventional arm and 1.49±0.59 LNs/min in the methylene blue arm (P=0.010). In the subgroup analyses, the quality and efficacy were both superior for the methylene blue dye method compared with the conventional method. The methylene blue technique is recommended for harvesting LNs during gastric cancer surgery on the basis of both the quality and efficacy.

  14. 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.

  15. Effects of silver and Group II fluorides addition to plasma sprayed chromium carbide high temperature solid lubricant for foil gas bearings to 650/sup 0/C

    SciTech Connect

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

    1985-01-01

    A new self-lubricating coating composition of nickel aluminide-bonded chromium carbide fromulated with silver and Group II fluorides was developed. One of the proposed applications for this new coating composition is as a wide temperature spectrum solid lubricant for compliant foil gas bearings. Friction and wear properties were obtained using a foil gas bearing start/stop apparatus at temperatures from 25 to 650/sup 0/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 additional components were provided to assist in achieving low friction over the temperature range of interest. Uncoated, preoxidized inconel X-750 foil bearing 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.

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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.)

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

    PubMed

    Manghelli, Joshua; Brown, Lisa; Tadros, Hany B; Munfakh, Nabil A

    2015-10-01

    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

  4. 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.

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

    PubMed

    Souza, Erick Miranda; Pappen, Fernanda Geraldes; Shemesh, Hagay; Bonanato-Estrela, Cristiane; Bonetti-Filho, Idomeo

    2009-12-01

    Methylene blue (MB) remains the most frequently used tracer for dye penetration tests of endodontic fillings, despite its chemical reactions with different materials. This study checked whether dye penetration displayed by MB is comparable to Rhodamine B (RB). One hundred and seventy-two root canals were filled with gutta-percha and six sealers. Samples were covered with nail varnish except for the apical area, and immersed in MB or RB solutions under negative pressure. After 24 h, roots were bisected, photographed and the maximal dye penetration recorded. Dye penetrations displayed by MB and RB were compared (Newman-Keuls test). MB and RB displayed comparable results for groups filled with AH Plus, EndoREZ and Polifil (P > 0.05). For Endofill, Sealer 26 and Sealapex, a significant lower dye penetration was observed when MB was used (P < 0.05). Laboratory tests using MB for measuring dye penetration through filled root canals can result in misleading conclusions.

  6. 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

  7. 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.

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

    PubMed

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

    2009-10-29

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

  9. Methylene blue protects astrocytes against glucose oxygen deprivation by improving cellular respiration.

    PubMed

    Roy Choudhury, Gourav; Winters, Ali; Rich, Ryan M; Ryou, Myoung-Gwi; Gryczynski, Zygmunt; Yuan, Fang; Yang, Shao-Hua; Liu, Ran

    2015-01-01

    Astrocytes outnumber neurons and serve many metabolic and trophic functions in the mammalian brain. Preserving astrocytes is critical for normal brain function as well as for protecting the brain against various insults. Our previous studies have indicated that methylene blue (MB) functions as an alternative electron carrier and enhances brain metabolism. In addition, MB has been shown to be protective against neurodegeneration and brain injury. In the current study, we investigated the protective role of MB in astrocytes. Cell viability assays showed that MB treatment significantly protected primary astrocytes from oxygen-glucose deprivation (OGD) & reoxygenation induced cell death. We also studied the effect of MB on cellular oxygen and glucose metabolism in primary astrocytes following OGD-reoxygenation injury. MB treatment significantly increased cellular oxygen consumption, glucose uptake and ATP production in primary astrocytes. In conclusion our study demonstrated that MB protects astrocytes against OGD-reoxygenation injury by improving astrocyte cellular respiration.

  10. Methylene blue-assisted technique for harvesting lymph nodes after radical surgery for gastric cancer: a prospective randomized phase III study

    PubMed Central

    2014-01-01

    Background This randomized Phase III trial will evaluate whether the methylene blue-assisted technique is efficient for harvesting lymph nodes after radical surgery for gastric cancer. Methods/design Patients that undergo distal or total gastrectomy with radical nodal dissection will be randomly assigned to Group A: the standard group, the lymph nodes (LNs) will be harvested from the fresh specimen immediately after surgery, or Group B: the methylene blue-assisted group, where the LNs will be harvested from specimens fixed with 10% buffered formalin with methylene blue for 48 hours after surgery. The primary endpoint is the ratio of the number of the harvested LNs per time (minute). The secondary endpoint is the number of harvested LNs. A 25% reduction in the ratio of harvested lymph-node/time (minute) was determined to be necessary for this test treatment, considering the balance between the cost and benefit. Retrospective data was used to estimate the ratio of the number of the harvested LNs per time (minute) to be 40/30 minutes in Group A. A 25% risk reduction and a rate of 40/22.5 minutes is expected in Group B. Therefore, the sample size required ensuring a two-sided alpha error of 5% and statistical power of 80% is 52 patients, with 26 patients per arm. The number of patients to be accrued was set at 60 in total, due to the likelihood of enrolling ineligible patients. Trial registration UMIN000008624 PMID:24597931

  11. Aminothienopyridazines and Methylene Blue Affect Tau Fibrillization via Cysteine Oxidation*

    PubMed Central

    Crowe, Alex; James, Michael J.; Lee, Virginia M.-Y.; Smith, Amos B.; Trojanowski, John Q.; Ballatore, Carlo; Brunden, Kurt R.

    2013-01-01

    Alzheimer disease and several other neurodegenerative disorders are characterized by the accumulation of intraneuronal fibrils comprised of the protein Tau. Tau is normally a soluble protein that stabilizes microtubules, with splice isoforms that contain either three (3-R) or four (4-R) microtubule binding repeats. The formation of Tau fibrils is thought to result in neuronal damage, and inhibitors of Tau fibrillization may hold promise as therapeutic agents. The process of Tau fibrillization can be replicated in vitro, and a number of small molecules have been identified that inhibit Tau fibril formation. However, little is known about how these molecules affect Tau fibrillization. Here, we examined the mechanism by which the previously described aminothieno pyridazine (ATPZ) series of compounds inhibit Tau fibrillization. Active ATPZs were found to promote the oxidation of the two cysteine residues within 4-R Tau by a redox cycling mechanism, resulting in the formation of a disulfide-containing compact monomer that was refractory to fibrillization. Moreover, the ATPZs facilitated intermolecular disulfide formation between 3-R Tau monomers, leading to dimers that were capable of fibrillization. The ATPZs also caused cysteine oxidation in molecules unrelated to Tau. Interestingly, methylene blue, an inhibitor of Tau fibrillization under evaluation in Alzheimer disease clinical trials, caused a similar oxidation of cysteines in Tau and other molecules. These findings reveal that the ATPZs and methylene blue act by a mechanism that may affect their viability as potential therapeutic agents. PMID:23443659

  12. Adsorption behavior of methylene blue on carbon nanotubes.

    PubMed

    Yao, Yunjin; Xu, Feifei; Chen, Ming; Xu, Zhongxiao; Zhu, Zhiwen

    2010-05-01

    The effect of temperature on the equilibrium adsorption of methylene blue dye from aqueous solution using carbon nanotubes was investigated. The equilibrium adsorption data were analyzed using two widely applied isotherms: Langmuir and Freundlich. The results revealed that Langmuir isotherm fit the experimental results well. Kinetic analyses were conducted using pseudo-first and second-order models and the intraparticle diffusion model. The regression results showed that the adsorption kinetics were more accurately represented by pseudo-second-order model. The activation energy of system (Ea) was calculated as 18.54 kJ/mol. Standard free energy changes (DeltaG(0)), standard enthalpy change (DeltaH(0)), and standard entropy change (DeltaS(0)) were calculated using adsorption equilibrium constants obtained from the Langmuir isotherm at different temperatures. All DeltaG(0) values were negative; the DeltaH(0) values and DeltaS(0) values of CNTs were 7.29 kJ/mol and 64.6 J/mol K, respectively. Results suggested that the methylene blue adsorption on CNTs was a spontaneous and endothermic process.

  13. Photobiological properties of positively charged methylene violet analogs.

    PubMed

    Houghtaling, M A; Perera, R; Owen, K E; Wagner, S; Kuhn, R J; Morrison, H

    2000-01-01

    O-Methyl methylene violet (OMeMV), O-methyl bromomethylene violet (OMeBrMV) and O-methyl iodomethylene violet (OMeIMV) have been prepared in order to test their potential utility as anti-viral and anti-tumor phototoxic dyes. Rates of photosensitized toxicity of KB cells with 633 nm irradiation are (x 10(-19) photon-1): 2.4, 2.2, 1.9 and 0.17 for OMeIMV, OMeBrMV, methylene violet (MV) and OMeMV, respectively. Rates of photosensitized inactivation of Sindbis virus in phosphate-buffered saline with 633 nm irradiation are (x 10(-18) photon-1): 3.3, 1.8, 0.99, 0.15 for MV, OMeIMV, OMeBrMV and OMeMV, respectively. Quantum efficiencies for singlet oxygen formation were determined as OMeIMV, 0.64; OMeBrMV, 0.40; OMeMV, 0.054. Titration of the dyes with double-stranded (ds)DNA resulted in bathochromic shifts and hypochromic effects in the visible absorption spectra. Association constants for interaction of the methylated dyes with dsDNA of approximately 1 x 10(5) M-1 were determined by Scatchard analysis of equilibrium dialysis and UV absorption titration data. Photolysis of the halogenated dyes with DNA under argon led to covalent bond formation with the nucleic acid; there was no evidence of covalent binding in the dark.

  14. Methylene as a possible universal footprinting reagent that will include hydrophobic surface areas: overview and feasibility: properties of diazirine as a precursor.

    PubMed Central

    Richards, F. M.; Lamed, R.; Wynn, R.; Patel, D.; Olack, G.

    2000-01-01

    Methylene is one of, if not the, most reactive organic chemical known. It has a very low specificity, which makes it essentially useless for synthesis, but suggests a possible role in protein footprinting with special importance in labeling solvent accessible nonpolar areas, identifying ligand binding sites, and outlining interaction areas on protomers that form homo or hetero oligomers in cellular assemblies. The singlet species is easily and conveniently formed by photolysis of diazirine. The reactions of interest are insertion into C-H bonds and addition to multiple bonds, both forming strong covalent bonds and stable compounds. Reaction with proteins and peptides is reported even in aqueous solutions where the vast majority of the reagent is used up in forming methanol. Species containing up to 5 to 10 extra :CH2 groups are easily detected by electrospray mass spectroscopy. In a mixture of a 14 Kd protein and a noninteracting 1.7 Kd peptide, the distribution of mass peaks in the electrospray spectra was close to that expected from random modification of the estimated solvent accessible area for the two molecules. For analysis at the single residue level, quantitation at labeling levels of one 13CH2 group per 10 to 20 kDa of protein appears to be possible with isotope ratio mass spectroscopy. In the absence of reactive solvents, photolysis of diazirine produces oily polymeric species that contain one or two nitrogen atoms, but not more, and are water soluble. PMID:11206072

  15. Methylene as a possible universal footprinting reagent that will include hydrophobic surface areas: overview and feasibility: properties of diazirine as a precursor.

    PubMed

    Richards, F M; Lamed, R; Wynn, R; Patel, D; Olack, G

    2000-12-01

    Methylene is one of, if not the, most reactive organic chemical known. It has a very low specificity, which makes it essentially useless for synthesis, but suggests a possible role in protein footprinting with special importance in labeling solvent accessible nonpolar areas, identifying ligand binding sites, and outlining interaction areas on protomers that form homo or hetero oligomers in cellular assemblies. The singlet species is easily and conveniently formed by photolysis of diazirine. The reactions of interest are insertion into C-H bonds and addition to multiple bonds, both forming strong covalent bonds and stable compounds. Reaction with proteins and peptides is reported even in aqueous solutions where the vast majority of the reagent is used up in forming methanol. Species containing up to 5 to 10 extra :CH2 groups are easily detected by electrospray mass spectroscopy. In a mixture of a 14 Kd protein and a noninteracting 1.7 Kd peptide, the distribution of mass peaks in the electrospray spectra was close to that expected from random modification of the estimated solvent accessible area for the two molecules. For analysis at the single residue level, quantitation at labeling levels of one 13CH2 group per 10 to 20 kDa of protein appears to be possible with isotope ratio mass spectroscopy. In the absence of reactive solvents, photolysis of diazirine produces oily polymeric species that contain one or two nitrogen atoms, but not more, and are water soluble.

  16. 21 CFR 700.19 - Use of methylene chloride as an ingredient of cosmetic products.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  17. 21 CFR 700.19 - Use of methylene chloride as an ingredient of cosmetic products.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  18. 21 CFR 700.19 - Use of methylene chloride as an ingredient of cosmetic products.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  19. 21 CFR 700.19 - Use of methylene chloride as an ingredient of cosmetic products.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  20. 21 CFR 700.19 - Use of methylene chloride as an ingredient of cosmetic products.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  1. 21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Methylene blue-containing drugs for use in animals. 500.27 Section 500.27 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... according to label directions. The specific cause of the reaction was determined to be the methylene...

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

    PubMed

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

    2003-08-01

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

  3. Synthesis of novel 6,6'-methylene-bis-[3-(2-anilinoacetyl)-4-hydroxycoumarin] derivatives.

    PubMed

    Sanjeeva Reddy, Cherkupally; Raghu, Mekala

    2008-12-01

    The synthesis of novel 6,6'-methylene-bis-[3-(2-anilinoacetyl)-4-hydroxycoumarin] derivatives 6a-f was achieved in excellent yields from 6,6'-methylene-bis-[3-(2-bromoacetyl)-4-hydroxycoumarin] 5 and various arylamines. 5,5'-Methylene-bis-ethylsalicylate 3 was obtained by the esterfication of 5,5'-methylene-bis-salicylic acid 2 with ethanol, which was in turn obtained from salicylic acid 1 and formaldehyde. Cyclocondensation of 3 with ethyl acetoacetate resulted in 6,6'-methylene-bis-[3-acetyl-4-hydroxycoumarin] 4, which on selective alpha-bromination with molecular bromine in the presence of montmorillonite K10-AlCl(3) catalyst, in chloroform-ethyl acetate binary solvent mixture at room temperature, afforded the compound 5 in excellent yield. All the newly synthesized compounds were characterized by their spectral data.

  4. 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.

  5. 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.

  6. 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.

  7. Photosensitization of Aggregatibacter actinomycetemcomitans with methylene blue: a microbiological and spectroscopic study

    NASA Astrophysics Data System (ADS)

    Yamada Júnior, Aécio M.; Prates, Renato A.; Cai, Silvana; Ribeiro, Martha S.

    2008-03-01

    The aim of this study was to determinate the efficiency of methylene blue (MB) to kill cultures of Aggregatibacter actinomycetemcomitans under red light and to investigate MB photobleaching by optical absorption spectroscopy. Bacteria were diluted in aqueous solution, putted in glass tubes and distributed in 5 groups: (L-MB-) control group; (L+MB-) laser alone by 5min; (L-MB+) MB alone through 5min; (3L+MB+) MB+laser 3min; (5L+MB+) MB+laser 5min. Laser parameters were P=30mW, λ=660nm, E=9J in 5min and E=5.4J in 3min. The samples were diluted and bacterial colonies were counted and converted into colony forming units (CFU). Absorption spectra of the MB-stained bacterial suspension and photosensitized bacterial suspension were obtained. Groups L-MB-, L+MB-, and L-MB+ did not show a decrease in CFU/mL. L+MB+ groups showed a significant decrease in CFU/mL but no statistically significant differences were observed between 3min and 5min. Spectroscopy showed that MB is photodegraded after irradiation and that dimer species are more notably consumed than monomeric species. These results suggest that MB is a suitable photosensitizer to reduce A. actinomycetemcomitans, and that 3min of irradiation are enough to produce a significant effect. Due to the spectral changes observed on MB solution after irradiation a type I mechanism may be involved.

  8. Study of Methylene Blue adsorption on keratin nanofibrous membranes.

    PubMed

    Aluigi, A; Rombaldoni, F; Tonetti, C; Jannoke, L

    2014-03-15

    In this work, keratin nanofibrous membranes (mean diameter of about 220nm) were prepared by electrospinning and tested as adsorbents for Methylene Blue through batch adsorption tests. The adsorption capacity of the membranes was evaluated as a function of initial dye concentration, pH, adsorbent dosage, time and temperature. The adsorption capacity increased with increasing the initial dye concentration and pH, while it decreased with increasing the adsorbent dosage and temperature, indicating an exothermic process. The adsorption results indicated that the Langmuir isotherm fitted the experimental data better than the Freundlich and Temkin isotherm models. A mean free energy evaluated through the Dubinin-Radushkevich model of about 16kJmol(-1), indicated a chemisorption process which occurred by ion exchange. The kinetic data were found to fit the pseudo-second-order model better than the pseudo-first-order model. The obtained results suggest that keratin nanofibrous membranes could be promising candidates as dye adsorption filters.

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. Male mice housed in groups engage in frequent fighting and show a lower response to additional bone loading than females or individually housed males that do not fight.

    PubMed

    Meakin, Lee B; Sugiyama, Toshihiro; Galea, Gabriel L; Browne, William J; Lanyon, Lance E; Price, Joanna S

    2013-05-01

    Experiments to investigate bone's physiological adaptation to mechanical loading frequently employ models that apply dynamic loads to bones in vivo and assess the changes in mass and architecture that result. It is axiomatic that bones will only show an adaptive response if the applied artificial loading environment differs in a significant way from that to which the bones have been habituated by normal functional loading. It is generally assumed that this normal loading is similar between experimental groups. In the study reported here we found that this was not always the case. Male and female 17-week-old C57BL/6 mice were housed in groups of six, and a single episode (40 cycles) of non-invasive axial loading, engendering 2,200 με on the medial surface of the proximal tibiae in sample mice, was applied to right tibiae on alternate days for two weeks. This engendered an adaptive increase in bone mass in females, but not males. Observation revealed the main difference in behaviour between males and females was that males were involved in fights 1.3 times per hour, whereas the females never fought. We therefore housed all mice individually. In females, there was a similar significant osteogenic response to loading in cortical and trabecular bone of both grouped and individual mice. In contrast, in males, adaptive increases in the loaded compared with non-loaded control bones was only apparent in animals housed individually. Our interpretation of these findings is that the frequent vigorous fighting that occurs between young adult males housed in groups could be sufficient to engender peak strains and strain rates that equal or exceed the stimulus derived from artificial loading. This indicates the importance of ensuring that physical activity is consistent between groups. Reducing the background level of the naturally engendered strain environment allows adaptive responses to artificial loading to be demonstrated at lower loads.

  15. 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

    2015-06-23

    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.

  16. 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

  17. 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

  18. 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

  19. Poly(amic acid)-modified biomass of baker's yeast for enhancement adsorption of methylene blue and basic magenta.

    PubMed

    Yu, Jun-xia; Li, Bu-hai; Sun, Xiao-mei; Yuan, Jun; Chi, Ru-an

    2010-03-01

    In this study, poly(amic acid)-modified biomass was prepared to improve the adsorption capacities for two cationic dyes, methylene blue and basic magenta. X-ray photoelectron spectroscopy and potentiometric titration demonstrated that a large number of imide, amine, and carboxyl groups were introduced on the biomass surface, and the concentrations of these functional groups were calculated to be 0.27, 1.08, and 1.08 mmol g(-1) by using the first derivative method. According to the Langmuir equation, the maximum uptake capacities (q(m)) for methylene blue and basic magenta were 680.3 and 353.4 mg g(-1), respectively, which were 13- and sevenfold than that obtained on the unmodified biomass. Adsorption kinetics study showed that the completion of the adsorption process needed only 40 min, which is faster than the common sorbent such as activated carbon and resin. Experimental results showed that pH and ionic strength had little effect on the capacity of the modified biomass, indicating that the modified biomass had good potential for practical use.

  20. 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.

  1. ON THE NATURE OF THE DYE PENETRATING THE VACUOLE OF VALONIA FROM SOLUTIONS OF METHYLENE BLUE.

    PubMed

    Irwin, M

    1927-07-20

    When uninjured cells of Valonia are placed in methylene blue dissolved in sea water it is found, after 1 to 3 hours, that at pH 5.5 practically no dye penetrates, while at pH 9.5 more enters the vacuole. As the cells become injured more dye enters at pH 5.5, as well as at pH 9.5. No dye in reduced form is found in the sap of uninjured cells exposed from 1 to 3 hours to methylene blue in sea water at both pH values. When uninjured cells are placed in azure B solution, the rate of penetration of dye into the vacuole is found to increase with the rise in the pH value of the external dye solution. The partition coefficient of the dye between chloroform and sea water is higher at pH 9.5 than at pH 5.5 with both methylene blue and azure B. The color of the dye in chloroform absorbed from methylene blue or from azure B in sea water at pH 5.5 is blue, while it is reddish purple when absorbed from methylene blue and azure B at pH 9.5. Dry salt of methylene blue and azure B dissolved in chloroform appears blue. It is shown that chiefly azure B in form of free base is absorbed by chloroform from methylene blue or azure B dissolved in sea water at pH 9.5, but possibly a mixture of methylene blue and azure B in form of salt is absorbed from methylene blue at pH 5.5, and azure B in form of salt is absorbed from azure B in sea water at pH 5.5. Spectrophotometric analysis of the dye shows the following facts. 1. The dye which is absorbed by the cell wall from methylene blue solution is found to be chiefly methylene blue. 2. The dye which has penetrated from methylene blue solution into the vacuole of uninjured cells is found to be azure B or trimethyl thionine, a small amount of which may be present in a solution of methylene blue especially at a high pH value. 3. The dye which has penetrated from methylene blue solution into the vacuole of injured cells is either methylene blue or a mixture of methylene blue and azure B. 4. The dye which is absorbed by chloroform from methylene

  2. MtsR is a dual regulator that controls virulence genes and metabolic functions in addition to metal homeostasis in the group A streptococcus.

    PubMed

    Toukoki, Chadia; Gold, Kathryn M; McIver, Kevin S; Eichenbaum, Zehava

    2010-05-01

    MtsR is a metal-dependent regulator in the group A streptococcus (GAS) that directly represses the transcription of genes involved in haem and metal uptake. While MtsR has been implicated in GAS virulence, the DNA recognition and full regulatory scope exerted by the protein are unknown. In this study we identified the shr promoter (P(shr)) and mapped MtsR binding to a 69 bp segment in P(shr) that overlaps the core promoter elements. A global transcriptional analysis demonstrated that MtsR modulates the expression of 64 genes in GAS, 44 of which were upregulated and 20 were downregulated in the mtsR mutant. MtsR controls genes with diverse functions including metal homeostasis, nucleic acid and amino acid metabolism, and protein fate. Importantly, the MtsR regulon includes mga, emm49 and ska, which are central for GAS pathogenesis. MtsR binding to the promoter region of both negatively and positively regulated genes demonstrates that it functions as a dual regulator. MtsR footprints are large (47-130 bp) and vary between target promoters. A 16 bp motif that consists of an interrupted palindrome is implicated in the DNA recognition by the metalloregulator. In conclusion, we report here that MtsR is a global regulator in GAS that shapes the expression of vital virulence factors and genes involved in metabolic functions and metal transport, and we discuss the implications for the GAS disease process.

  3. 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.

  4. [Introduction of additional thiol groups into glucoamylase in Aspergillus awamori and their effect on the thermal stability and catalytic activity of the enzyme].

    PubMed

    Surzhik, M A; Shmidt, A E; Glazunov, E A; Firsov, D L; Petukhov, M G

    2014-01-01

    Five mutant forms of glucoamylase (GA) from the filamentous fungus Aspergillus awamori with artificial disulfide bonds (4D-G137A\\A14C, 6D-A14C\\Y419C\\G137A, 10D-V13C\\G396C, 11D-V13C\\G396C\\A14C\\Y419C\\G137A, and 20D-G137A\\A246C\\A14C) were constructed using computer simulation and experimentally tested for thermostability. The introduction of two additional disulfide bonds between its first and thirteenth alpha-helices and that of the loop located close to a catalytic residue--E400--made it possible to assess the effects of disulfide bridges on protein thermostability. The mutant proteins with combined amino acid substitutions G137A\\A14C, V13C\\G396C\\A14C\\Y419C\\G137A, and G137A\\A246C\\A14C showed higher thermal stability as compared to the wild-type protein. At the same time, new disulfide bridges in the mutant A14C\\Y419C\\G137A and V13C\\G396C proteins led to the destabilization of their structure and the loss of thermal stability.

  5. Surface properties and adsorption characteristics to methylene blue and iodine of adsorbents from sludge.

    PubMed

    Deng, L Y; Xu, G R; Li, G B

    2010-01-01

    Adsorbent materials created from wastewater sludge have unique surface characteristics and could be effective in adsorption applications. In this research, the sludge-adsorbents were generated by pyrolyzing mixtures of sewage sludge and H(2)SO(4). Scanning electron microscope (SEM), thermal analysis, X-ray diffraction (XRD) and X-ray photoelectron spectroscope (XPS) were used to analyze the properties of sludge-adsorbent. XPS results show that the adsorbent surface functional groups with high contents of oxygen-containing groups serve as active sites for the adsorption and affect the surface characteristics; the adsorption mechanism of methylene blue (MB) is mainly Brönsted acid-base reaction between the adsorbent surface and MB; and iodine atoms are bonded to the surface of the adsorbent mainly by dispersive interactions rather than by electrostatic interactions. The results also show that H(2)SO(4) level, pyrolysis temperature and sulfuric acid/sludge weight ratio actually affected the adsorption characteristics. Using the conditions (H(2)SO(4) level of 1-18 M, pyrolysis temperature of 650°C, and weight ratio of 0.8), the adsorption capacities for MB and iodine were 74.7-62.3 mg g(-1) and 169.5-209.3 mg g(-1), respectively.

  6. Highly effective removal of Methylene Blue using functionalized attapulgite via hydrothermal process.

    PubMed

    Zhang, Zhifang; Wang, Wenbo; Wang, Aiqin

    2015-07-01

    Attapulgite (APT) has been frequently used for the adsorptive removal of dyes from aqueous solution owing to its unique one-dimensional nanoscale structure and low-cost, abundant, eco-friendly advantages. In this work, APT was functionalized under mild hydrothermal condition using chloroacetic acid (CA) with COOH functional groups to improve its adsorption properties. The effect of hydrothermal modification on the microstructure and physicochemical features of APT was investigated by Fourier transform infrared spectroscopy, X-ray diffraction and Field-emission scanning electron microscopy analyses. The effects of hydrothermal reaction parameters on the adsorption properties of modified APT were intensively investigated. It was revealed that the rearrangement of crystal structure and the surface functionalization of APT with COOH groups cause the surprising increase of adsorption capability for Methylene Blue (MB). The removal ratio of raw APT for MB is only 59.52%, while modified APT could almost completely remove MB in the 200 mg/L of MB solution with a removal ratio of 99.8%. The adsorption kinetics fitted pseudo second-order kinetic model, and the adsorption isotherm could be described with Langmuir isotherm model very well. The hydrogen-bonding interaction, electrostatic attraction and chemical association are the main driving force for the adsorption process.

  7. Miscibility of phospholipids with identical headgroups and acyl chain lengths differing by two methylene units: effects of headgroup structure and headgroup charge.

    PubMed

    Garidel, P; Blume, A

    1998-04-22

    We have investigated the influence of the chemical structure and charge of the hydrophillic headgroup on the miscibility of saturated phospholipids with acyl chain lengths differing by two methylene units, namely DMPA/DPPA, DMPC/DPPC, DMPE/DPPE and DMPG/DPPG (0.1 M NaCl). All four mixtures were analysed by DSC at pH 7. To study the influence of a change in headgroup charge, we additionally investigated DMPA/DPPA mixtures at pH 4 and 12, and DMPG/DPPG mixtures at pH 2. The experimental DSC thermograms were fitted using methods described before [Johann et al., Biophys. J. 71 (1996), 3215-3228] to obtain the temperatures of onset and end of melting and first approximations for the non-ideality parameters as a function of composition. The resulting phase diagrams were then fitted using a four non-ideality parameter model for non-ideal, non-symmetric mixing in both phases. The phase diagram of the system DMPG/DPPG has a lens-like shape, the non-ideality parameters rhog and rhol for the gel and the liquid-crystalline phase, respectively, are zero, indicating ideal mixing in both phases. For the other mixtures, differences in miscibility are observed depending on the structure of the headgroup. At pH 7, rhog > rhol, i.e., the miscibility in the liquid-crystalline phase is more ideal than in the gel state. All rhog values are positive and the sequence for rhog observed is PA>PE>PC>PG. Partial protonation of PA at pH 4 or complete deprotonation at pH 12 leads to negative non-ideality parameters for both phases, indicating a preference for mixed pair formation. Protonation of PG in DMPG/DPPG mixtures at pH 2 leads to positive non-ideality parameters for both phases, indicating a tendency for demixing. The results show, that the miscibility of phospholipids with identical headgroups but chain lengths differing by two methylene groups is dependent on headgroup structure and on headgroup charge.

  8. 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

  9. Quantum dot/methylene blue FRET mediated NIR fluorescent nanomicelles with large Stokes shift for bioimaging.

    PubMed

    Li, Li; Liu, Jianbo; Yang, Xiaohai; Peng, Zhihong; Liu, Wei; Xu, Jianguo; Tang, Jinlu; He, Xiaoxiao; Wang, Kemin

    2015-10-01

    Here we present a novel large Stokes shifting NIR fluorescent nanomicelle through the encapsulation of a quantum dot/methylene blue FRET pair, which is employed as an excellent contrast reagent for NIR fluorescence bioimaging. PMID:26267557

  10. Safety of methylene blue dye for lymphatic mapping in patients taking selective serotonin reuptake inhibitors.

    PubMed

    Shah-Khan, Miraj G; Lovely, Jenna; Degnim, Amy C

    2012-11-01

    Methylene blue dye has an important role in lymphatic mapping for sentinel lymph node surgery. A recent safety announcement from the US Food and Drug Administration warned physicians about possible serious central nervous system reactions in patients on serotonergic medications who received intravenous methylene blue for the identification of parathyroid glands. This report summarizes evidence from the Food and Drug Administration's announcement and methylene blue pharmacokinetics. The authors conclude that the use of methylene blue dye at low doses for lymphatic mapping likely carries very little risk for serotonin neurotoxicity, although breast surgeons should be aware of this potential complication in the event of mental status or neuromuscular changes in patients after lymphatic mapping.

  11. Removal of methylene blue from wastewater using fly ash as an adsorbent by hydrocyclone.

    PubMed

    Rastogi, K; Sahu, J N; Meikap, B C; Biswas, M N

    2008-10-30

    The excessive release of color into the environment is a major concern worldwide. Adsorption process is among the most effective techniques for color removal from wastewater and fly ash has been widely used as an adsorbent. Therefore, this study was carried out to understand the adsorption behavior of methylene blue from aqueous systems onto fly ash using the continuous mode. Continuous mode sorption experiments were carried out to remove methylene blue from its aqueous solutions in hydrocyclone equipment. The experiments were performed at constant temperature and dimensions of hydrocyclone with variation of flows through the equipment, concentrations of methylene blue solutions and fly ash concentration, respectively. A maximum removal of 58.24% was observed at adsorbent dosage of 900 mg/l at pH 6.75 for an initial methylene blue concentration of 65 mg/l.

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

    PubMed

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

    2011-07-01

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

  13. Adsorption of methylene blue onto bamboo-based activated carbon: kinetics and equilibrium studies.

    PubMed

    Hameed, B H; Din, A T M; Ahmad, A L

    2007-03-22

    Bamboo, an abundant and inexpensive natural resource in Malaysia was used to prepare activated carbon by physiochemical activation with potassium hydroxide (KOH) and carbon dioxide (CO(2)) as the activating agents at 850 degrees C for 2h. The adsorption equilibrium and kinetics of methylene blue dye on such carbon were then examined at 30 degrees C. Adsorption isotherm of the methylene blue (MB) on the activated carbon was determined and correlated with common isotherm equations. The equilibrium data for methylene blue adsorption well fitted to the Langmuir equation, with maximum monolayer adsorption capacity of 454.2mg/g. Two simplified kinetic models including pseudo-first-order and pseudo-second-order equation were selected to follow the adsorption processes. The adsorption of methylene blue could be best described by the pseudo-second-order equation. The kinetic parameters of this best-fit model were calculated and discussed.

  14. Formaldehyde and methylene glycol equivalence: critical assessment of chemical and toxicological aspects.

    PubMed

    Golden, R; Valentini, M

    2014-07-01

    Due largely to the controversy concerning the potential human health effects from exposure to formaldehyde gas in conjunction with the misunderstanding of the well-established equilibrium relationship with its hydrated reaction product, methylene glycol, the concept of chemical equivalence between these two distinctly different chemicals has been adopted by regulatory authorities. Chemical equivalence implies not only that any concentration of methylene glycol under some condition of use would be nearly or completely converted into formaldehyde gas, but also that these two substances would be toxicologically equivalent as well. A relatively simple worst case experiment using 37% formalin (i.e., concentrated methylene glycol) dispels the concept of chemical equivalence and a review of relevant literature demonstrates that methylene glycol has no inherent toxicity apart from whatever concentration of formaldehyde that might be present in equilibrium with such solutions.

  15. Photoacoustic lifetime imaging of dissolved oxygen using methylene blue

    NASA Astrophysics Data System (ADS)

    Ashkenazi, Shai

    2010-07-01

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

  16. Adsorption of methylene blue onto sonicated sepiolite from aqueous solutions.

    PubMed

    Küncek, Ilknur; Sener, Savaş

    2010-01-01

    The aim of the present study is to enhance the methylene blue (MB) adsorption of sepiolite by ultrasonic treatment. The natural sepiolite was pretreated by sonication to improve the surface characteristics and enhance the dye uptake capacity. Sonication process resulted in a significant increase in the specific surface area (SSA) of sepiolite. The FTIR spectrum of the sonicated sepiolite indicates that the tetrahedral sheet is probably distorted after sonication process. The effect of various parameters such as sonication, pH, initial dye concentration and temperature on dye adsorption has been investigated. The adsorbed amount of MB on sepiolite increased after sonication as well as with increasing pH and temperature. The experimental data were evaluated by applying the pseudo-first- and second-order, and the intraparticle diffusion adsorption kinetic models. Adsorption process of MB onto sepiolite followed the pseudo-second-order rate expression. The experimental data were analyzed by Langmuir and Freundlich isotherms, and found that the isotherm data were reasonably well correlated by Langmuir isotherm. Maximum monolayer adsorption capacity of sepiolite for MB increased from 79.37 to 128.21 mg/g after the sonication. Various thermodynamic parameters, such as Delta G(0), Delta H(0) and DeltaS(0) were calculated. The thermodynamics of MB/sepiolite system indicated spontaneous and endothermic nature of the process. Adsorption measurements showed that the process was very fast and physical in nature.

  17. Removal of methylene blue by lava adsorption and catalysis oxidation.

    PubMed

    Ma, Jianfeng; Zhang, Jinbao; Li, Dinglong

    2010-03-01

    Adsorption has been found to be effective for the removal of dyes from effluent; however, the contaminant will cause secondary pollution if it is not properly treated. In this paper, the ability of lava as a low-cost adsorbent and catalyst for the removal of a commercial dye, Methylene Blue (MB), from aqueous solution has been investigated under various experimental conditions. It was found that lava had a high efficiency (more than 98%) for MB removal by adsorption. The adsorption equilibrium data can be fitted well by the Langmuir adsorption isotherm model. The adsorption kinetics was shown to be pseudo-second-order. After adsorption the contaminant could be catalysis oxidized by lava with the aids of H2O2 and ultrasound. The result showed that 95% of the MB could be decomposed in 100 min with the aid of ultrasound at 85 W/cm2. Overall, this study demonstrates lava as a promising material for wastewater treatment to remove and decompose dyes in a single treatment step.

  18. 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

  19. [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.

  20. 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

  1. Amino group combined P/Ge and P/Sn Lewis pairs: synthesis and dipolar addition reactions to alkyne and aldehyde molecules.

    PubMed

    Yu, Ying; Li, Jiancheng; Liu, Weiping; Ye, Qingsong; Zhu, Hongping

    2016-04-14

    Amino group combined P/Ge-based frustrated Lewis pairs (FLPs) Ph2PN(R)GeCl3 (R = 2,6-iPr2C6H3 (1), 2,4,6-Me3C6H2 (2), and C6H11 (3)) and Ph2PN(2,6-iPr2C6H3)GeMe3 (4) as well as P/Sn-based FLP Ph2PN(2,6-iPr2C6H3)SnMe3 (5) were prepared and utilized for reactions with alkyne and aldehyde molecules. Compounds 1-3 each reacted with MeO2CC[triple bond, length as m-dash]CCO2Me to give zwitterionic cyclic vinyls [Ph2PN(R)GeCl3](MeO2CC[double bond, length as m-dash]CCO2Me) (6-8) and compound 1 reacted with HC[triple bond, length as m-dash]CCO2Me to give the similar compound [Ph2PN(2,4,6-Me3C6H2)GeCl3](HC[double bond, length as m-dash]CCO2Me) (9). Compound 4 reacted with RC[triple bond, length as m-dash]CCO2Me to afford acyclic vinyls 2,6-iPr2C6H3N[double bond, length as m-dash]P(Ph2)C(R)[double bond, length as m-dash]C(CO2Me)GeMe3 (R = CO2Me (10), H (11)) and 5 reacted with MeO2CC[triple bond, length as m-dash]CCO2Me to give 2,6-iPr2C6H3N[double bond, length as m-dash]P(Ph2)C(CO2Me)[double bond, length as m-dash]C(CO2Me)SnMe3 (12). The reactions of 1 with CH3CH2CHO and 1,4-(CHO)2C6H4 were also investigated and yielded novel zwitterionic OCPNGe five-heteroatom cycles [Ph2PN(2,6-iPr2C6H3)GeCl3][CH(CH2CH3)O] (13) and [Ph2PN(2,6-iPr2C6H3)GeCl3][p-(OCH)C6H4CHO][Cl3GeN(2,6-iPr2C6H3)PPh2] (14). Compounds 1-14 were characterized by NMR ((1)H, (13)C, and (31)P) and CHN elemental analysis, of which 1, 7, and 10-14 were further studied by X-ray crystallography. The reactions of 4 (or 5) with RC[triple bond, length as m-dash]CCO2Me to produce 10-12 present a novel way of obtaining the germyl (or stannyl) and iminophosphoranyl co-substituted vinyls.

  2. Amino group combined P/Ge and P/Sn Lewis pairs: synthesis and dipolar addition reactions to alkyne and aldehyde molecules.

    PubMed

    Yu, Ying; Li, Jiancheng; Liu, Weiping; Ye, Qingsong; Zhu, Hongping

    2016-04-14

    Amino group combined P/Ge-based frustrated Lewis pairs (FLPs) Ph2PN(R)GeCl3 (R = 2,6-iPr2C6H3 (1), 2,4,6-Me3C6H2 (2), and C6H11 (3)) and Ph2PN(2,6-iPr2C6H3)GeMe3 (4) as well as P/Sn-based FLP Ph2PN(2,6-iPr2C6H3)SnMe3 (5) were prepared and utilized for reactions with alkyne and aldehyde molecules. Compounds 1-3 each reacted with MeO2CC[triple bond, length as m-dash]CCO2Me to give zwitterionic cyclic vinyls [Ph2PN(R)GeCl3](MeO2CC[double bond, length as m-dash]CCO2Me) (6-8) and compound 1 reacted with HC[triple bond, length as m-dash]CCO2Me to give the similar compound [Ph2PN(2,4,6-Me3C6H2)GeCl3](HC[double bond, length as m-dash]CCO2Me) (9). Compound 4 reacted with RC[triple bond, length as m-dash]CCO2Me to afford acyclic vinyls 2,6-iPr2C6H3N[double bond, length as m-dash]P(Ph2)C(R)[double bond, length as m-dash]C(CO2Me)GeMe3 (R = CO2Me (10), H (11)) and 5 reacted with MeO2CC[triple bond, length as m-dash]CCO2Me to give 2,6-iPr2C6H3N[double bond, length as m-dash]P(Ph2)C(CO2Me)[double bond, length as m-dash]C(CO2Me)SnMe3 (12). The reactions of 1 with CH3CH2CHO and 1,4-(CHO)2C6H4 were also investigated and yielded novel zwitterionic OCPNGe five-heteroatom cycles [Ph2PN(2,6-iPr2C6H3)GeCl3][CH(CH2CH3)O] (13) and [Ph2PN(2,6-iPr2C6H3)GeCl3][p-(OCH)C6H4CHO][Cl3GeN(2,6-iPr2C6H3)PPh2] (14). Compounds 1-14 were characterized by NMR ((1)H, (13)C, and (31)P) and CHN elemental analysis, of which 1, 7, and 10-14 were further studied by X-ray crystallography. The reactions of 4 (or 5) with RC[triple bond, length as m-dash]CCO2Me to produce 10-12 present a novel way of obtaining the germyl (or stannyl) and iminophosphoranyl co-substituted vinyls. PMID:26658532

  3. 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

  4. 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.

  5. 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

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

    PubMed

    Golshan, Mehra; Nakhlis, Faina

    2006-01-01

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

  7. 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

  8. 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/

  9. Experimental Design Approach for Methylene Blue Dye Removal in Aqueous Environment by Nitrilotriacetic Modified Banana Pith.

    PubMed

    Lee, Shi-Ling; Liew, Shu-Wei; Ong, Siew-Teng

    2016-01-01

    Native banana pith (NBP) was modified by using nitrilotriacetic acid to increase its efficiency and adsorption capacity for methylene blue (MB) dye. The effect of various parameters such as pH, contact time and initial dye concentration, sorption isotherm and adsorbent dosage were studied. The maximum adsorption capacity of the NBP and NTA-BP is 100 and 142.86 mg/g, respectively. The IR spectrum of NBP and NTA-BP showed the presence of both carboxyl and hydroxyl groups. From the SEM micrographs, the surface morphology of NTA-BP before adsorption appeared to be smoother as compared to that after adsorption process. The pH(pzc) of NBP is 5.6 whereas for NTA-BP is 7.6. The experimental data fitted well into Langmuir isotherm with R(2) of 0.992. Plackett-Burman design was applied to identify the significant factors in affecting the uptake whereas the interaction between the factors and their optimum levels for the maximum percentage uptake of MB were determined using response surface methodology (RSM). Based on the results, the optimum condition for adsorption of MB was by using 0.06 g of NTA-BP in dye solution at pH 6 with 120 minutes contact time. The maximum adsorption of MB by NTA-BP achieved 99.42% under the optimum condition.

  10. Mechanism of Adsorptive Removal of Methylene Blue Using Dried Biomass of Rhizopus oryzae.

    PubMed

    Dey, Manash Deep; Shukla, Ruchi; Bordoloi, Naba K; Doley, Robin; Mukhopadhyay, Rupak

    2015-09-01

    Adsorption is an efficient way to remove synthetic dyes from industrial effluent. Here, we show mechanism of adsorptive removal of cationic dye methylene blue (MB) from its aqueous solution using dried biomass of Rhizopus oryzae as a biosorbent. The optimum pH and temperature for adsorption was found to be 7.0 and 28 °C, respectively. Scanning electron microscopy (SEM) of the biomass suggested distinct changes in surface topology post-MB adsorption, while Fourier transform infrared (FTIR) study indicated chemical interaction between the surface of the biomass and MB. Chemical modification of -OH and -C=O groups of biomass reduced the MB adsorption and corroborated with the FTIR analyses. Kinetics study revealed that the adsorption rate was fast initially and reached equilibrium at 4 h following a pseudo-second-order-kinetics. The adsorption isotherm followed Freundlich isotherm model with n value of 1.1615.The dried biomass of R. oryzae can be used as a potent biosorbent for the removal of MB.

  11. Removal of methylene blue from aqueous solutions by chemically modified bamboo.

    PubMed

    Guo, Jian-Zhong; Li, Bing; Liu, Li; Lv, Kangle

    2014-09-01

    Chemically modified bamboo (CMB) was utilized for removing methylene blue (MB) from aqueous media in the present study. The adsorbent was characterized by Fourier transform infrared (FTIR) spectra and elemental analysis, which confirms that carboxyl groups and diethylenetriamine were successfully introduced into the surface of bamboo. The effects of initial MB concentration (100-900mgL(-1)), contact time (15-315min), the pH of the solution (3-10), temperature (298-318K), adsorbent dosage (0.4-2.6gL(-1)) and salt concentration on the adsorption efficiency of CMB towards MB were investigated. It was found that the adsorption of MB in CMB fits Langmuir mode well, and the maximum adsorption capacity of CMB achieved 606mgg(-1) at 298K, which is much higher than those obtained from previously investigated bioadsorbents. The adsorption kinetics can be described by pseudo-second-order kinetic model, and the adsorption of MB on CMB was an exothermic process. The results of the present study suggest that CMB is an effective biosorbent for removal of organic pollutants from aqueous solutions.

  12. 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

  13. [Adsorption behavior of copper ion and methylene blue on citric acid- esterified wheat straw].

    PubMed

    Sun, Jin; Zhong, Ke-Ding; Feng, Min; Liu, Xing-Yan; Gong, Ren-Min

    2008-03-01

    A cationic adsorbent with carboxyl groups derived from citric acid- esterified wheat straw (EWS) was prepared by the method of solid phase preparation, and a batch experiment was conducted to study the adsorption behaviors of Cu (II) and methylene blue (MB) in aqueous solution on the EWS under conditions of different initial pH, adsorbent dosage, adsorbate concentration, and contact time. The results showed that the maximum adsorption of Cu (II) and MB was obtained when the initial solution pH was > or = 4.0. 96% of Cu (II) in 100 mg x L(-1) Cu solution and 99% of MB in 250 mg x L(-1) dye solution could be removed by > or = 2.0 g x L(-1) of EWS. The adsorption of Cu (II) and MB fitted the Langmuir sorption isothermal model. The maximum removal capacity (Qm) of EWS was 79.37 mg x g(-1) for Cu (II) and 312.50 mg x g(-1) for MB, and the adsorption equilibrium of Cu (II) and MB was reached within 75 min and 5 h, respectively. The adsorption processes of Cu (II) and MB could be described by pseudo-first order and pseudo-second order kinetic functions, respectively.

  14. 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.

  15. Enhanced photodynamic therapy efficacy of methylene blue-loaded calcium phosphate nanoparticles.

    PubMed

    Seong, Da-Young; Kim, Young-Jin

    2015-05-01

    Although methylene blue (MB) is the most inexpensive photosensitizer with promising applications in the photodynamic therapy (PDT) for its high quantum yield of singlet oxygen generation, the clinical use of MB has been limited by its rapid enzymatic reduction in the biological environment. To enhance PDT efficacy of MB by preventing the enzymatic reduction, we have developed a new mineralization method to produce highly biocompatible MB-loaded calcium phosphate (CaP-MB) nanoparticles in the presence of polymer templates. The resulting CaP-MB nanoparticles exhibited spherical shape with a size of under 50 nm. Fourier transform infrared (FT-IR) and zeta-potential analyses confirmed the insertion of MB into the CaP-MB nanoparticles. The encapsulation of MB in CaP nanoparticles could effectively protect MB from the enzymatic reduction. In addition, the CaP-MB nanoparticles exhibited a good biocompatibility in the dark condition and significantly enhanced PDT efficacy due to apoptotic cell death against human breast cancer cells as compared with free MB, implying that CaP-MB nanoparticle system might be potentially applicable in PDT.

  16. 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.

  17. [Adsorption properties of modified graphene for methylene blue removal from wastewater].

    PubMed

    Wu, Yan; Luo, Han-Jin; Wang, Hou; Zhang, Zi-Long; Wang, Can; Wang, Yu-Wei

    2013-11-01

    In this study, cetyltrimethylammonium bromide (CTAB) was chosen to modify graphene, which was applied to remove methylene blue (MB) from aqueous solutions. The characteristics of graphene and modified graphene were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), thermal gravimetric analyzer (TGA), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The effects of factors including pH, contact time, temperature, and dosage on the adsorption properties of MB onto graphene and modified graphene were investigated. The results revealed that the addition of CTAB in preparation could obviously increase the specific surface area and improve the efficiency of removal. The adsorption processes were rapid within the first 15 min and reached equilibrium in about 120 min. The adsorption kinetics fitted well with the pseudo-second-order model. The optimal reaction temperature was 293 K, the optimal concentration of adsorbent dosage was 2 g x L(-1), and the initial pH value of the solution had little impact on the amount of adsorption. The adsorption capacity of MB on modified graphene inferred from the Langmuir model was 86.43 mg x g(-1) at 293 K, and the adsorption was an exothermic process.

  18. 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.

  19. Removal of methylene blue from aqueous solution by Artist's Bracket fungi: kinetic and equilibrium studies.

    PubMed

    Naghipour, Daryush; Taghavi, Kamran; Moslemzadeh, Mehrdad

    2016-01-01

    In this study, adsorption of methylene blue (MB) dye onto Artist's Bracket (AB) fungi was investigated in aqueous solution. Fourier transform infrared and scanning electron microscopy were used to investigate surface characteristic of AB fungi. Influence of operational parameters such as pH, contact time, biosorbent dosage, dye concentration, inorganic salts and temperature was studied on dye removal efficiency. With the increase of pH from 3 to 9, removal efficiency increased from 74.0% to 90.4%. Also, it reduced from 99.8% to 81.8% with increasing initial MB concentration from 25 mg L(-1) to 100 mg L(-1), whereas it increased from 54.7% to 98.7% and from 98.5% to 99.9% with increasing biosorbent dosage from 0.5 g L(-1) to 2 g L(-1) and with increasing temperature from 25 °C to 50 °C, respectively. Isotherm studies have shown adsorption of MB dye over the AB fungi had a better coefficient of determination (R(2)) of 0.98 for Langmuir isotherm. In addition, the maximum monolayer adsorption capacity (qm) was 100 mg g(-1). Also, the MB dye adsorption process followed pseudo-second-order kinetic. In general, AB fungi particles can be favorable for removal of MB dye from dye aqueous solution with natural pH and high temperature. PMID:27232421

  20. Methylene Blue Reduces Acute Cerebral Ischemic Injury via the Induction of Mitophagy.

    PubMed

    Di, Yao; He, Yun-Ling; Zhao, Tong; Huang, Xin; Wu, Kui-Wu; Liu, Shu-Hong; Zhao, Yong-Qi; Fan, Ming; Wu, Li-Ying; Zhu, Ling-Ling

    2015-05-19

    The treatment of stroke is limited by a short therapeutic window and a lack of effective clinical drugs. Methylene blue (MB) has been used in laboratories and clinics since the 1890s. Few studies have reported the neuroprotective role of MB in cerebral ischemia-reperfusion injury. However, whether and how MB protects against acute cerebral ischemia (ACI) injury was unclear. In this study, we investigated the effect of MB on this injury and revealed that MB protected against ACI injury by augmenting mitophagy. Using a rat middle cerebral artery occlusion (MCAO) model, we demonstrated that MB improved neurological function and reduced the infarct volume and necrosis after ACI injury. These improvements depended on the effect of MB on mitochondrial structure and function. ACI caused the disorder and disintegration of mitochondrial structure, while MB ameliorated the destruction of mitochondria. In addition, mitophagy was inhibited at 24 h after stroke and MB augmented mitophagy. In an oxygen-glucose deprivation (OGD) model in vitro, we further revealed that the elevation of mitochondrial membrane potential (MMP) by MB under OGD conditions mediated the augmented mitophagy. In contrast, exacerbating the decline of MMP during OGD abolished the MB-induced activation of mitophagy. Taken together, MB promotes mitophagy by maintaining the MMP at a relatively high level, which contributes to a decrease in necrosis and an improvement in neurological function, thereby protecting against ACI injury.

  1. 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

  2. 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.

  3. Removal of basic dye (methylene blue) from wastewaters utilizing beer brewery waste.

    PubMed

    Tsai, Wen-Tien; Hsu, Hsin-Chieh; Su, Ting-Yi; Lin, Keng-Yu; Lin, Chien-Ming

    2008-06-15

    In the work, the beer brewery waste has been shown to be a low-cost adsorbent for the removal of basic dye from the aqueous solution as compared to its precursor (i.e., diatomite) based on its physical and chemical characterizations including surface area, pore volume, scanning electron microscopy (SEM), and non-mineral elemental analyses. The pore properties of this waste were significantly larger than those of its raw material, reflecting that the trapped organic matrices contained in the waste probably provided additional adsorption sites and/or adsorption area. The results of preliminary adsorption kinetics showed that the diatomite waste could be directly used as a potential adsorbent for removal of methylene blue on the basis of its adsorption-biosorption mechanisms. The adsorption parameters thus obtained from the pseudo-second-order model were in accordance with their pore properties. From the results of adsorption isotherm at 298 K and the applicability examinations in treating industrial wastewater containing basic dye, it was further found that the adsorption capacities of diatomite waste were superior to those of diatomite, which were also in good agreement with their corresponding physical properties. From the results mentioned above, it is feasible to utilize the food-processing waste for removing dye from the industrial dying wastewater.

  4. 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

  5. Methylene Blue Modulates β-Secretase, Reverses Cerebral Amyloidosis, and Improves Cognition in Transgenic Mice*

    PubMed Central

    Mori, Takashi; Koyama, Naoki; Segawa, Tatsuya; Maeda, Masahiro; Maruyama, Nobuhiro; Kinoshita, Noriaki; Hou, Huayan; Tan, Jun; Town, Terrence

    2014-01-01

    Amyloid precursor protein (APP) proteolysis is required for production of amyloid-β (Aβ) peptides that comprise β-amyloid plaques in the brains of patients with Alzheimer disease (AD). Here, we tested whether the experimental agent methylene blue (MB), used for treatment of methemoglobinemia, might improve AD-like pathology and behavioral deficits. We orally administered MB to the aged transgenic PSAPP mouse model of cerebral amyloidosis and evaluated cognitive function and cerebral amyloid pathology. Beginning at 15 months of age, animals were gavaged with MB (3 mg/kg) or vehicle once daily for 3 months. MB treatment significantly prevented transgene-associated behavioral impairment, including hyperactivity, decreased object recognition, and defective spatial working and reference memory, but it did not alter nontransgenic mouse behavior. Moreover, brain parenchymal and cerebral vascular β-amyloid deposits as well as levels of various Aβ species, including oligomers, were mitigated in MB-treated PSAPP mice. These effects occurred with inhibition of amyloidogenic APP proteolysis. Specifically, β-carboxyl-terminal APP fragment and β-site APP cleaving enzyme 1 protein expression and activity were attenuated. Additionally, treatment of Chinese hamster ovary cells overexpressing human wild-type APP with MB significantly decreased Aβ production and amyloidogenic APP proteolysis. These results underscore the potential for oral MB treatment against AD-related cerebral amyloidosis by modulating the amyloidogenic pathway. PMID:25157105

  6. 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.

  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. 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

  9. 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.

  10. 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

  11. Urea enhances the photodynamic efficiency of methylene blue.

    PubMed

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

    2015-09-01

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

  12. 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.

  13. 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.

  14. 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

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

    PubMed

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

    2013-09-01

    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 quasi-stable 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 (10μM-10mM), 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.

  16. 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

  17. 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

  18. Methylene-bis[(aminomethyl)phosphinic acids]: synthesis, acid-base and coordination properties.

    PubMed

    David, Tomáš; Procházková, Soňa; Havlíčková, Jana; Kotek, Jan; Kubíček, Vojtěch; Hermann, Petr; Lukeš, Ivan

    2013-02-21

    Three symmetrical methylene-bis[(aminomethyl)phosphinic acids] bearing different substituents on the central carbon atom, (NH(2)CH(2))PO(2)H-C(R(1))(R(2))-PO(2)H(CH(2)NH(2)) where R(1) = OH, R(2) = Me (H(2)L(1)), R(1) = OH, R(2) = Ph (H(2)L(2)) and R(1),R(2) = H (H(2)L(3)), were synthesized. Acid-base and complexing properties of the ligands were studied in solution as well as in the solid state. The ligands show unusually high basicity of the nitrogen atoms (log K(1) = 9.5-10, log K(2) = 8.5-9) if compared with simple (aminomethyl)phosphinic acids and, consequently, high stability constants of the complexes with studied divalent metal ions. The study showed the important role of the hydroxo group attached to the central carbon atom of the geminal bis(phosphinate) moiety. Deprotonation of the hydroxo group yields the alcoholate anion which tends to play the role of a bridging ligand and induces formation of polynuclear complexes. Solid-state structures of complexes [H(2)N=C(NH(2))(2)][Cu(2)(H(-1)L(2))(2)]CO(3)·10H(2)O and Li(2)[Co(4)(H(-1)L(1))(3)(OH)]·17.5H(2)O were determined by X-ray diffraction. The complexes show unexpected geometries forming dinuclear and cubane-like structures, respectively. The dinuclear copper(II) complex contains a bridging μ(2)-alcoholate group with the (-)O-P(=O)-CH(2)-NH(2) fragments of each ligand molecule chelated to the different central ion. In the cubane cobalt(II) complex, one μ(3)-hydroxide and three μ(3)-alcoholate anions are located in the cube vertices and both phosphinate groups of one ligand molecule are chelating the same cobalt(II) ion while each of its amino groups are bound to different neighbouring metal ions. All such three metal ions are bridged by the alcoholate group of a given ligand.

  19. Orientation of functional groups of soil organic matter on the surface of water repellent soils determined by pulse saturation magic angle spinning (PSTMAS) nuclear magnetic resonance (NMR) spectroscopy

    NASA Astrophysics Data System (ADS)

    Hiradate, Syuntaro; Kawamoto, Ken; Senani Wijewardana, Nadeeka; Müller, Karin; Møldrup, Per; Clothier, Brent; Komatsu, Toshiko

    2014-05-01

    Orientation of functional groups of soil organic matter on soil particles plays a crucial role in the occurrence of soil water repellency. In addition to a general method to characterize soil organic matter using cross polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) technique, we determined the surface orientation of functional groups in water repellent soils by using pulse saturation magic angle spinning (PSTMAS) NMR technique. A preliminary experiment confirmed that the PSTMAS NMR spectrum successfully determined the high mobility of methyl group of octadecylsilylated silica gels when a comparison was made with that of CPMAS NMR. This means that the methyl group oriented towards the outside of the silica gel particle. Similarly, for an experimental system consisting of mixtures of octadecylsilylated silica gel and dimethyl sulfoxide (DMSO), the extremely high mobility of methyl group derived from DMSO was detected using the same methodology. For water repellent soils from Japan and New Zealand, it was found that the methyl and methylene groups were highly mobile. In contrast, the NMR signals of aromatic moiety, another hydrophobic moiety of soil organic matter, were not as intense in PSTMAS compared with CPMAS. From these results, we conclude that alkyl moiety (methyl and methylene groups) would be oriented towards the outside of the soil particle and would play an important role in the appearance of water repellency of soils.

  20. Heinz-body hemolytic anemia associated with ingestion of methylene blue in a river otter.

    PubMed

    Narurkar, Neelesh S; Thomas, Jennifer S; Phalen, David N

    2002-02-01

    Heinz-body hemolytic anemia and nephrosis associated with hemoglobinuria were diagnosed in a North American river otter. Fluids were administered, and the signs of renal failure improved immediately. Severe anemia developed, and the otter received a semisynthetic hemoglobin product to maintain the oxygen-carrying capacity of the blood until a blood transfusion could be given. Immediate clinical improvement was observed following hemoglobin administration, and adverse effects were not seen. Six days after admission, the otter began to produce its own RBC and recovered without complications. The Heinz-body anemia was determined to be caused by methylene blue that was in the water of minnows consumed by the otter the night before it became ill. Methylene blue is a common ingredient in products used to extend the life of bait fish. Bait fish kept in water treated with methylene blue should not be used as food for fish-eating animals.

  1. 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

  2. Adsorption of chlorophenol, chloroaniline and methylene blue on fuel oil fly ash.

    PubMed

    Andini, Salvatore; Cioffi, Raffaele; Colangelo, Francesco; Montagnaro, Fabio; Santoro, Luciano

    2008-09-15

    Fuel oil fly ash has been tested as low-cost carbon-based adsorbent of 2-chlorophenol (CP), 2-chloroaniline (CA) and methylene blue (MB) from aqueous solutions. In all the cases the adsorption was found to be of cooperative type. Different adsorption capacities were found for the three organics. Specifically, it was highest for 2-chlorophenol, reaching about 70 mg g(-1), and quite lower in the other two cases, that is about 47 and 36 mg g(-1) for methylene blue and 2-chloroaniline, respectively. Varying the initial pH and adding KCl were found to have different effects on the adsorption of the three organics. In particular, the presence of other ions had no effect on the adsorption of methylene blue, adverse effect in the case of 2-chlorophenol and enhancing effect in the case of 2-chloroaniline.

  3. 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.

  4. 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.

  5. 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

  6. Aggregation of 1,3,7-trimethylxanthine with methylene blue in aqueous solution

    NASA Astrophysics Data System (ADS)

    Baranovskii, S. F.; Bolotin, P. A.; Evstigneev, M. P.

    2006-03-01

    We have studied self-association of aromatic molecules of the thiazine dye methylene blue in aqueous solution, using a dimer model. We have determined the dimerization equilibrium constant for the dye molecules KD = 3900 ± 800 M-1 at T = 293 K. We have decomposed the experimental spectrum into dimer and monomer components. Using the ratio of the molar absorption coefficients for two absorption bands of the dimer spectrum, we obtained the “average” value of the angle between the electronic transition moments of the molecules in the dimers, α = 48°. We have studied heteroassociation of methylene blue (MB) and 1,3,7-trimethylxanthine (caffeine) molecules in aqueous solution. We have calculated the heteroassociation constant as 200 ± 34 M-1. We conclude that heteroassociation of methylene blue and caffeine molecules leads to a lower effective dye concentration in solution, which hypothetically may affect its biological activity. We have determined the values of the Gibbs free energy, the enthalpy, and the entropy for dimerization of methylene blue molecules: ΔG293 = -(20 ± 3) kJ/mol, ΔH = -(25 ± 9) kJ/mol, Δ S293 = -(17 ± 6) J/mol·K; and for methylene blue-caffeine heteroassociation: ΔG293 = -(13 ± 3) kJ/mol, ΔH = -(14 ± 10) kJ/mol, ΔS293 = -(2.4 ± 0.2) J/mol·K, respectively. We have shown that the methylene blue aggregates and the heteroassociates with caffeine are predominantly stabilized by dispersion interactions between the chromophore molecules in the associates.

  7. 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

  8. 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

  9. 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.

  10. 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...

  11. Effect of Gelatin-Stabilized Copper Nanoparticles on Catalytic Reduction of Methylene Blue

    NASA Astrophysics Data System (ADS)

    Musa, Aminu; Ahmad, Mansor B.; Hussein, Mohd Zobir; Saiman, Mohd Izham; Sani, Hannatu Abubakar

    2016-10-01

    The synthesis of copper nanoparticles was carried out with gelatin as a stabilizer by reducing CuSO4.5H2O ions using hydrazine. Ascorbic acid and aqueous NaOH were also used as an antioxidant and pH controller, respectively. The effects of NaOH, hydrazine, and concentration of gelatin as stabilizer were studied. The synthesized copper nanoparticles were characterized by UV-vis spectroscopy, XRD, zeta potential measurements, FTIR, EDX, FESEM, and TEM. The formation of CuNPs@Gelatin is initially confirmed by UV-vis spectroscopic analysis with the characteristic band at 583 nm. XRD and TEM reports revealed that CuNPs@Gelatin (0.75 wt.%) is highly crystalline and spherical in shape with optimum average size of 4.21 ± 0.95 nm. FTIR studies indicated the presence of amide group on the surface of the CuNPs indicating the stability of CuNPs which is further supported by zeta potential measurements with the negative optimum value of -37.90 ± 0.6 mV. The CuNPs@G4 showed a good catalytic activity against methylene blue (MB) reduction using NaBH4 as a reducing agent in an aqueous solution. The best enhanced properties of CuNPs@G4 were found for the 0.75 wt.% gelatin concentration. Thermodynamic parameters (Δ H and Δ S) indicate that under the studied temperature, the reduction of MB by CuNPs@G4 is not feasible and had endothermic in nature.

  12. Doing the methylene shuffle--further insights into the inhibition of mitotic kinesin Eg5 with S-trityl L-cysteine.

    PubMed

    Abualhasan, Murad N; Good, James A D; Wittayanarakul, Kitiyaporn; Anthony, Nahoum G; Berretta, Giacomo; Rath, Oliver; Kozielski, Frank; Sutcliffe, Oliver B; Mackay, Simon P

    2012-08-01

    S-Trityl L-cysteine (STLC) is an inhibitor of the mitotic kinesin Eg5 with potential as an antimitotic chemotherapeutic agent. We previously reported the crystal structure of the ligand-protein complex, and now for the first time, have quantified the interactions using a molecular dynamics based approach. Based on these data, we have explored the SAR of the trityl head group using the methylene shuffle strategy to expand the occupation of one of the hydrophobic pockets. The most potent compounds exhibit strong (<100 nM) inhibition of Eg5 in the basal ATPase assay and inhibit growth in a variety of tumour-derived cell lines.

  13. 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

  14. 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.

  15. Electrode erosion during submerged arc treatment of methylene blue water solution

    NASA Astrophysics Data System (ADS)

    Parkansky, Naum; Yakubov, Violetta; Beilis, Isak I.; Boxman, Raymond L.; Berkh, Olga

    2015-06-01

    Low voltage, low energy submerged pulsed arcs with a pulse repetition rate of 100 Hz, energy of 48 mJ and duration of 20 μs were used to determine the electrode erosion rate during treatment of 10 mg l-1 methylene blue (MB) dissolved in 40 ml of deionized water, with and without the addition of 0.5% H2O2. Anode/cathode pairs of Fe/Fe, Ti/Ti, Cu/Cu, Cu/Fe, Fe/Cu, Ti/Fe, Fe/Ti, Cu/Ti and Ti/Cu were used. Smaller cathode erosion was measured, in the solutions without H2O2, with copper cathodes than with other cathodes. Smaller anode erosion in the same conditions was demonstrated by using pairs with a Ti anode than with other anodes and larger erosion was found for Cu anodes. By adding H2O2 to the treated solution, smaller cathode erosion was measured by using pairs with a Ti cathode than with other cathodes and larger rates were measured for Fe cathodes. The largest anode erosion was observed for a Cu anode. The erosion of the anode and cathode depends on material combination of the electrode pairs, i.e. on the thermo physical properties of the electrode materials. The correlations of anode/cathode erosion ratio (Ga/Gc) with ratio (qam/qcm) for various electrode materials were found, where qam and qcm are heat fluxes in the body of the anode and cathode, respectively. The experimental data were fitted by curves described with equation Ga/Gc =A(qa/qc)-b where A and b are experimental constants.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. The feasibility of using methylene blue sensitized polyvinylalcohol film as a linear polarizer

    SciTech Connect

    Jyothilakshmi, K.; Anju, K. S.; Arathy, K.; John, Beena Mary; Krishna, P. B.; Sruthi, C. T.; Chacko, Maria

    2014-01-28

    Linear light polarizing films selectively transmit radiations vibrating along an electromagnetic radiation vector and selectively absorb radiations vibrating along a second electromagnetic radiation vector. It happens according to the anisotropy of the film . In the present study the polarization effects of methylene blue sensitized polyvinyl alcohol is investigated. The polarization effects on the dye concentration, heating and stretching of film also are evaluated.

  1. 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...

  2. 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...

  3. Rapid alkaline methylene blue supravital staining for assessment of anterior segment infections

    PubMed Central

    Kiuchi, Katsuji

    2016-01-01

    Purpose To present the Löffler’s alkaline methylene blue technique of staining eye discharges in eyes with anterior segment infections. Method The Löffler’s alkaline methylene blue staining method is a simple staining technique that can be used to differentiate bacterial, viral, and fungal infections. It is a cationic dye that stains cells blue because the positively charged dye is attracted to negatively charged particles such as polyphosphates, DNAs, and RNAs. Specimens collected from patients by swabbing are smeared onto microscope slides and the methylene blue solution is dropped on the slide. The slide is covered with a glass cover slip and examined under a microscope. The entire time from the collection to the viewing is about 30 seconds. Results Histopathological images of the conjunctival epithelial cells and neutrophils in eye discharges were dyed blue and the nuclei were stained more intensely blue. Bacterial infections consisted mainly of neutrophils, and viral infections consisted mainly of lymphocytes. Conclusions Löffler’s alkaline methylene blue staining can be done in about 30 seconds for diagnosis. Even though this is a one color stain, it is possible to infer the cause of the infection by detection of the absence of bacteria and/or fungi in context of the differential distribution of neutrophils and lymphocytes. PMID:27784986

  4. 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...

  5. 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...

  6. 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...

  7. 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...

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

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

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

  9. 21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... 500.27 Section 500.27 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... cats or dogs. (1)(i) It has been demonstrated that two orally administered urinary antiseptic-antispasmodic preparations that contained methylene blue cause Heinz body hemolytic anemia in cats when...

  10. 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... cats or dogs. (1)(i) It has been demonstrated that two orally administered urinary antiseptic-antispasmodic preparations that contained methylene blue cause Heinz body hemolytic anemia in cats when...

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

    PubMed

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

    2011-04-01

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

  12. 21 CFR 520.154b - Bacitracin methylene disalicylate and streptomycin sulfate powder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.154b Bacitracin methylene disalicylate and streptomycin sulfate powder. (a..., Proteus spp., Staphylococcus spp., and Streptococcus spp., and for the symptomatic treatment of...

  13. 21 CFR 520.154b - Bacitracin methylene disalicylate and streptomycin sulfate powder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.154b Bacitracin methylene disalicylate and streptomycin sulfate powder. (a..., Proteus spp., Staphylococcus spp., and Streptococcus spp., and for the symptomatic treatment of...

  14. 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...

  15. 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

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

    PubMed

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

    2014-08-01

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

  17. 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

  18. CNS toxicity involving methylene blue: the exemplar for understanding and predicting drug interactions that precipitate serotonin toxicity.

    PubMed

    Gillman, P Ken

    2011-03-01

    Methylene blue has only recently been noted to cause severe central nervous system toxicity. Methylene blue is used for various conditions, including, intravenously, in methemoglobinemia, vasoplegia and as an aid to parathyroidectomy (at doses of 1-7.5 mg kg(-1)). This review of the current evidence concludes that 13 of 14 of the reported cases of CNS toxicity were serotonin toxicity that met the Hunter Serotonin Toxicity Criteria. That has important preventative and treatment implications. Serotonin toxicity is precipitated by the monoamine oxidase inhibitor (MAOI) property of methylene blue interacting with serotonin reuptake inhibitors. Serotonin toxicity is reviewed, using the lessons inherent in the methylene blue story and experience, to illustrate how the mechanisms and potency of serotonergic drugs interact to determine severity. Recent human data showed that an intravenous dose of only 0.75 mg kg(-1) of methylene blue produced a peak plasma concentration of 500 ng ml(-1) (1.6 µM), indicating that the concentration in the central nervous system reaches a level that inhibits monoamine oxidase A. That is consonant with the actual occurrence of severe serotonin toxicity in humans at the dose of only 1 mg kg(-1). It seems that all proposed uses of methylene blue entail levels that block monoamine oxidase, so cessation of serotonin reuptake inhibitors should be very carefully considered before using methylene blue.

  19. Effects of feeding diets containing bacitracin methylene disalicylate to heat-stressed finishing pigs.

    PubMed

    Song, R; Foster, D N; Shurson, G C

    2011-06-01

    The objective of this study was to evaluate the effects of heat stress and dietary bacitracin methylene disalicylate (BMD) on growth performance, carcass characteristics, and immunological responses in finishing pigs. Four groups of 32 finishing pigs (n = 128) with initial BW between 80 to 90 kg were used. Pigs were fed a corn-soybean meal-distillers grains-based control or BMD (31.5 mg/kg) diet for a 14-d adaptation period at the thermal neutral temperature (23°C), and continued to be fed their respective diets when exposed to a constant temperature (23°C) or a cyclical heat stress environment (37°C from 1000 to 1900 h and 27°C from 1900 to 1000 h) for a 28-d experimental period. Each group of pigs was housed in 4 rooms, with 2 pens/room and 4 pigs/pen. Saliva samples from each pig were collected on d -1 (initial baseline), 1, 13, and 27 for cortisol analysis. Concentrations of haptoglobin, IL-1β, and tumor necrosis factor-α were determined in serum samples on d -1, 1, 13, and 27. Pigs exposed to heat stress had 31% less ADG (P < 0.001), 23% less ADFI (P < 0.001), 9% less G:F (P < 0.001), and 34% greater average daily water intake (P = 0.03) than those in the non-heat-stress conditions. Dietary BMD tended to reduce ADG (P < 0.07) compared with the control (0.66 vs. 0.73 kg/d, respectively). Heat stress increased (P < 0.05) saliva cortisol on d 1, but no effects were observed on subsequent days. Serum haptoglobin concentrations were greater (P < 0.05) in heat-stressed pigs on d 1, and concentrations tended to remain greater (P < 0.1) on d 13. Pigs fed the BMD diet tended to have a longer villus height (P = 0.07) in the duodenum and greater crypt depths in the duodenum (P = 0.09) and jejunum (P = 0.07). Heat-stressed pigs tended to have a decreased proportion of propionate (P = 0.08), greater acetate:propionate (P = 0.08), and a reduced proportion of valerate (P = 0.02) in the cecum. These results indicate that BMD did not counteract the negative effects of

  20. 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.

  1. In vivo proton magnetic resonance spectroscopy of liver metabolites in non-alcoholic fatty liver disease in rats: T2 relaxation times in methylene protons.

    PubMed

    Song, Kyu-Ho; Baek, Hyeon-Man; Lee, Do-Wan; Choe, Bo-Young

    2015-10-01

    The aim of this study was to evaluate the transverse relaxation time of methylene resonance as compared to other lipid resonances. 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 with a repetition time (TR) of 6000ms and echo time (TE) of 40-550ms. For in vivo proton magnetic resonance spectroscopy ((1)H-MRS), eight male Sprague-Dawley rats were given free access to a normal-chow (NC) and another eight male Sprague-Dawley rats were given free access to a high-fat (HF) diet. Both groups drank water ad libitum. T2 measurements in the rats' livers were conducted at a fixed TR of 6000ms and TE of 40-220ms. Exponential curve fitting quality was calculated through the coefficients of determination (R(2)). Chemical analyses of the phantom and livers were not performed, but T2 decay curves were acquired. The T2 relaxation time of methylene resonance was estimated as follows: NC rats, 37.1±4.3ms; HF rats, 31.4±1.8ms (p<0.05). The extrapolated M0 values were higher in HF rats than in NC rats (p<0.005). This study of (1)H MRS led to sufficient spectral resolution and signal-to-noise ratio differences to characterize the T2 relaxation times of methylene resonance. (1)H MRS relaxation times may be useful for quantitative characterization of various liver diseases, including fatty liver disease.

  2. 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

  3. 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

  4. [Ectopic mediastinal parathyroid tumor resected by video-assisted thoracic surgery with intraoperative methylene blue infusion; report of a case].

    PubMed

    Okagawa, Takehiko; Hiramatsu, Yoshinori

    2014-03-01

    We report a surgical case of ectopic mediastinal parathyroid tumor resected by video-assisted thoracic surgery with intraoperative methylene blue infusion. It is often difficult to detect ectopic mediastinal parathyroid tumor during the operation because the tumor is soft, small and buried under mediastinal tissue. After methylene blue 4 mg/kg intravenously administration, the tumor was gradually dyed blue and easily detected and resected by video-assisted thoracic surgery. It is useful of methylene blue for detection of ectopic mediastinal parathyroid tumor.

  5. 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.

  6. Binding of methylene blue onto Langmuir monolayers representing cell membranes may explain its efficiency as photosensitizer in photodynamic therapy.

    PubMed

    Schmidt, Thaís F; Caseli, Luciano; Oliveira, Osvaldo N; Itri, Rosangela

    2015-04-14

    We provide evidence for the electrostatic interactions between the cationic photosensitizer methylene blue (MB) and cell membrane models represented by neat and mixed Langmuir monolayers of dioleylphosphatidylcholine (DOPC) and 1,1',2,2'-tetraoleoylcardiolipin (CL). From surface pressure measurements, MB was found to adsorb strongly and expand CL-containing monolayers, while it caused an apparent decreasing in molecular area on neat DOPC monolayer. The binding site of MB could be inferred from data with the surface-specific polarization-modulated infrared reflection-absorption spectroscopy (PM-IRRAS) technique, where changes induced by MB were observed in the vibrational modes of the phosphate groups of both CL and DOPC. The incorporation of MB also affected the carbonyl groups and the packing of the alkyl chains, thus indicating that MB binding site favors singlet oxygen generation close to the double bonds in the alkyl chains, an important requirement for photodynamic efficiency. Significantly, the data presented here demonstrate that MB may act in membranes composed by PCs, such as mammalian plasma membranes, and in those containing CL, as in bacterial and inner mitochondrial membranes.

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

    PubMed

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

    2014-08-08

    Poly(HexaMethylene Biguanide) hydrochloride (PHMB) CAS No. [32289-58-0] is a particularly effective member of the biguanides antiseptic chemical group, and has been in use since the early fifties in numerous applications. It has been proposed that PHMB be classified as a category 3 carcinogen although PHMB is not genotoxic. It has been hypothesized that PHMB may have epigenetic properties effects, including non-genotoxic modifications of DNA bases, DNA methylation and mitogenic cytokine production. These properties have been assessed in vitro using 3 cell types: Caco-2 cells (from a human colon adenocarcinoma) with a non-functional p53 gene. (∆p53: mut p53), N2-A (Neuro-2A cells, mouse neural cells), the brain being a possible target organ in rodents and HepG2 cells (human hepatocellular carcinoma) with functional p53 gene. From the concentration 1 µg/mL up to 20 µg/mL of PHMB, no effect was observed, either growth stimulation or inhibition. Viability testing using neutral red led to an IC 50 of 20-25 µg/mL after treatment with PHMB for 3 h, whereas the MTT test led to IC50 values of 80 µg/mL, 160 µg/mL and 160 µg/mL respectively for HepG2 cells, Neuro-2A cells and Caco-2 cells. PHMB does not induce significant oxidative stress (production of MDA or lipoperoxidation, nor does it induce hydroxylation of DNA (8-OH-dG) and/or its hypermethylation (m5dC), the latter being strongly implicated in DNA replication and regulation and cell division. PHMB does not induce significant production of mitogenic cytokines such as TNF-α (tumor necrosis factor), interleukins (IL-1 alpha), and the transcription factor nuclear factor kappa B (NF-κB) which can cause either apoptosis or stimulate the growth of transformed cells or tumors. Instead, from concentrations of 20 to 100 µg/mL, PHMB kills cells of all types in less than 3 h. The expression of genes involved in the mechanisms of cell death induced by PHMB, including p53, the pro apoptotic gene bax and others, the anti

  8. 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

  9. 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

  10. 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.

  11. Synthesis, characterization, and solvolysis of mono- and bis-S-(glutathionyl) adducts of methylene-bis-(phenylisocyanate) (MDI).

    PubMed

    Reisser, Martin; Schmidt, Brigitte F; Brown, William E

    2002-10-01

    Bifunctional isocyanates are highly reactive compounds that undergo nucleophilic attack by a variety of functional groups available in the biological system. While the etiology of the respiratory disease caused by diisocyanates is not fully understood, a great deal of research has been performed to elucidate the chemical mechanisms involved in the direct and indirect effects of these compounds. Since adducts of isocyanates are found not only to proteins along the entire respiratory tree but also to proteins in the circulatory system, it is likely that a transport mechanism for the isocyanate from the respiratory to the circulatory system exists. The initial reaction of isocyanates with cellular thiols to form thiocarbamates, which are known to release the isocyanate under physiological conditions, is believed to provide a possible carrier mechanism for the isocyanate functional group. Previous work with aliphatic mono-isocyanates and the aromatic diisocyanate toluene diisocyanate has demonstrated the feasibility of this mechanism. Adding to this database, the products of the reaction of the highly water-insoluble, low vapor pressure, methylene-bis-(phenylisocyanate) (MDI) with glutathione were synthesized, and their chemical stability under various pH and buffer conditions was tested. Novel synthetic routes were developed for both the mono- and bis-S-(glutathionyl) adducts with MDI that yielded each compound in analytically pure form. Both compounds were found to be unstable under mild basic conditions (phosphate-buffered saline, pH 7.4, and NaHCO(3), pH 8.2), however to a different degree. Furthermore, a significant influence of the pH value (the rate of degradation increases with pH) and the concentration of free glutathione (increasing thiol stabilizes the adduct) on the stability was observed, indicating a base-catalyzed mechanism of the degradation/formation of the thiocarbamate bond. Unlike the monoadduct, which forms almost exclusively the polyurea upon

  12. 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

  13. Methylene chloride exposure in furniture-stripping shops: ventilation and respirator use practices.

    PubMed

    Hall, A H; Rumack, B H

    1990-01-01

    Four cases of serious methylene chloride (dichloromethane) poisoning, including fatalities, in small-scale furniture-stripping shops were reported to the Rocky Mountain Poison and Drug Center between 1984 and 1988. Adequate ventilation systems and use of recommended respirators may seem impractical or overly expensive to the operators of such shops. Twenty-one shops in the metropolitan Denver, Colorado area were surveyed. A half-facepiece respirator with organic vapor cartridges was worn at least part-time in 14 of 21 shops; none was worn in 7. In 10 of 21 shops, workers had experienced dizziness, headache, or nausea when stripping furniture. Current safety practices in small-scale furniture-stripping shops may be inadequate to keep methylene chloride exposure levels in compliance with latest recommendations, and serious or fatal overexposure can occur.

  14. 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.

  15. 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...

  16. 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...

  17. Practical methylenation reaction for aldehydes and ketones using new Julia-type reagents.

    PubMed

    Ando, Kaori; Kobayashi, Takahisa; Uchida, Nariaki

    2015-05-15

    A new Julia-type methylenation reagent, 1-methyl-2-(methylsulfonyl)benzimidazole (1e), reacts with a variety of aldehydes and ketones in the presence of either NaHMDS (-55 °C to rt) or t-BuOK (rt, 1 h) in DMF to give the corresponding terminal alkenes in high yields. The byproducts are easily removed, and the reaction conditions are mild and practical.

  18. Reductive alkylation of active methylene compounds with carbonyl derivatives, calcium hydride and a heterogeneous catalyst.

    PubMed

    Guyon, Carole; Duclos, Marie-Christine; Sutter, Marc; Métay, Estelle; Lemaire, Marc

    2015-07-01

    A one-pot two-step reaction (Knoevenagel condensation - reduction of the double bond) has been developed using calcium hydride as a reductant in the presence of a supported noble metal catalyst. The reaction between carbonyl compounds and active methylene compounds such as methylcyanoacetate, 1,3-dimethylbarbituric acid, dimedone and the more challenging dimethylmalonate, affords the corresponding monoalkylated products in moderate to good yields (up to 83%) with minimal reduction of the starting carbonyl compounds. PMID:26053131

  19. 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

    2016-01-01

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

  20. 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

  1. 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

  2. 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

  3. 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

  4. Arylamino methylene bisphosphonate derivatives as bone seeking matrix metalloproteinase inhibitors.

    PubMed

    Tauro, Marilena; Laghezza, Antonio; Loiodice, Fulvio; Agamennone, Mariangela; Campestre, Cristina; Tortorella, Paolo

    2013-11-01

    The complexity of matrix metalloproteinase inhibitors (MMPIs) design derives from the difficulty in carefully addressing their inhibitory activity towards the MMP isoforms involved in many pathological conditions. In particular, specific metalloproteinases, such as MMP-2 and MMP-9, are key regulators of the 'vicious cycle' occurring between tumor metastases growth and bone remodeling. In an attempt to devise new approaches to selective inhibitor derivatives, we describe novel bisphosphonate bone seeking MMP inhibitors (BP-MMPIs), capable to be selectively targeted and to overcome undesired side effects of broad spectrum MMPIs. In vitro activity (IC50 values) for each inhibitor was determined against MMP-2, -8, -9 and -14, because of their relevant role in skeletal development and renewal. The results show that BP-MMPIs reached IC50 values of enzymatic inhibition in the low micromolar range. Computational studies, used to rationalize some trends in the observed inhibitory profiles, suggest a possible differential binding mode in MMP-2 that explains the selective inhibition of this isoform. In addition, survival assay was conducted on J774 cell line, a well known model system used to evaluate the structure-activity relationship of BPs for inhibiting bone resorption. The resulting data, confirming the specific activity of BP-MMPIs, and their additional proved propensity to bind hydroxyapatite powder in vitro, suggest a potential use of BP-MMPIs in skeletal malignancies.

  5. 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.

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

    PubMed

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

    2014-01-01

    Developing the application of high-strength hydrogels has gained much attention in the fields of medical, pharmacy, and pollutant removal due to their versatility and stimulus-responsive properties. In this presentation, a high-strength freestanding elastic hydrogel membrane was constructed by clay nanosheets, N, N-dimethylacrylamide and 2-acrylamide-2-methylpropanesulfonic acid for adsorption of methylene blue and heavy metal ions. The maximum values of elongation and Young's modulus for 0.5% AMPSNa hydrogel were 1901% and 949.4 kPa, respectively, much higher than those of traditional hydrogels. The adsorptions were confirmed to follow pseudo-second kinetic equation and Langmuir isotherm model fits the data well. The maximum adsorption capacity of hydrogel towards methylene blue was 434.8 mg g(-1). The hydrogel also exhibited higher separation selectivity to Pb(2+) than Cu(2+). The methylene blue adsorbed onto the hydrogel membrane can be photocatalytically degraded by Fenton agent and the hydrogel membrane could be recycled at least five times without obvious loss in mechanical properties. In conclusion, this presentation demonstrates a convenient strategy to prepare tough and elastic clay nanocomposite hydrogel, which can not only be applied as recyclable membrane for the photocatalytic degradation of organic dye, but also for the recovery of valuables. PMID:24586396

  7. Comparison of acridine orange, methylene blue, and Gram stains for blood cultures.

    PubMed Central

    Mirrett, S; Lauer, B A; Miller, G A; Reller, L B

    1982-01-01

    Direct microscopic screening of blood cultures by Gram stain or methylene blue stain is time consuming and frequently insensitive. Therefore, we evaluated a fluorescent-staining procedure that uses acridine orange (AO) at pH 3.5 and compared it with the methylene blue and Gram stain procedures. All smears were prepared within 24 h of receiving the culture, fixed with methanol, and examined without the results of the companion smears being known. AO-stained smears were examined with incident-light fluorescence at 600 x magnification and confirmed at 1,500x magnification. All bottles macroscopically positive within 24 h were excluded from the study. Of 2,946 cultures entered into the study, 204 (6.9%) were positive within 3 days. The sensitivity and specificity of AO based on these culture results were 52 and 98%, respectively, compared with 38% sensitivity and 99% specificity by methylene blue and Gram stains. The AO staining procedure is a simple, sensitive, screening technique for the early detection of positive blood cultures. PMID:6175656

  8. Adsorption of methylene blue from aqueous solution on pyrolyzed petrified sediment.

    PubMed

    Aroguz, Ayse Z; Gulen, J; Evers, R H

    2008-04-01

    The adsorption kinetics of methylene blue on pyrolyzed petrified sediment (PPS) has been performed using a batch-adsorption technique. The effects of various experimental parameters, such as initial dye concentration, contact time, and temperature were investigated. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetic data. The best correlation coefficient was obtained using the pseudo first-order kinetic model, which shows that the adsorption of methylene blue followed the pseudo-first-order rate expression and the rate constants were evaluated. The Langmuir and Freundlich adsorption isotherm models were applied to describe the equilibrium isotherms and the isotherm constants were determined. It was found that the data fitted well to Langmuir and Freundlich models. The activation energy of adsorption was also evaluated for the adsorption of methylene blue onto pyrolyzed sediment. It was found about 8.5 kJ mol(-1). Thermodynamics parameters DeltaG(o), DeltaH(o), DeltaS(o) were calculated, indicating that this process can be spontaneous and endothermic. The adsorption enthalpy and entropy were found as 14-18.5 kJ mol(-1) and 52.8-67 J mol(-1) K(-1), respectively. The results obtained from the adsorption process using PPS as adsorbent was subjected to student's t-test.

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

    PubMed

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

    2014-01-01

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

  10. 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.

  11. 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

  12. Mutations induced by methylene blue plus light in single-stranded M13mp2.

    PubMed Central

    McBride, T J; Schneider, J E; Floyd, R A; Loeb, L A

    1992-01-01

    Reactive oxygen species are generated by a variety of cellular processes. These endogenously generated, reactive intermediates produce a multiplicity of DNA alterations and mutations and have been implicated in the pathogenesis of several human diseases. We report here that treatment of single-stranded M13mp2 bacteriophage DNA with methylene blue and white light generates increased levels of 8-hydroxydeoxyguanosine and that mutagenesis is both highly specific and dependent on the SOS response. Lesions produced block the progression of DNA synthesis one base preceding template guanines. In SOS-induced Escherichia coli, 97% of all methylene blue-induced mutations in the lacZ alpha gene of M13mp2 DNA are single-base substitutions opposite template guanines. The most frequent mutations are G----C transversions. The G----T transversions expected from the presence of 8-hydroxydeoxyguanosine in the template strand occur, but at a lower frequency. Sequence data together with SOS dependency and the presence of replication blockage demonstrate that while 8-hydroxydeoxyguanosine may serve as an important marker to monitor oxygen-induced DNA damage in humans, it does not account for either the observed blockage to replication or the mutagenesis by methylene blue plus light in SOS-induced E. coli. Instead, an as yet unidentified lesion generated by active oxygen species is a more potent mutagenic event. Images PMID:1495976

  13. Methylene blue- and thiol-based oxygen depletion for super-resolution imaging.

    PubMed

    Schäfer, Philip; van de Linde, Sebastian; Lehmann, Julian; Sauer, Markus; Doose, Sören

    2013-03-19

    Anaerobic conditions are often required in solution-based bionanotechnological applications. Efficient oxygen depletion is essential for increasing photostability, optimizing fluorescence signals, and adjusting kinetics of fluorescence intermittency in single-molecule fluorescence spectroscopy/microscopy, particularly for super-resolution imaging techniques. We characterized methylene blue (MB)- and thiol-based redox reactions with the aim of designing an oxygen scavenger system as an alternative to the established enzyme-based oxygen scavenging systems or purging procedures. Redox reactions of the chromophore methylene blue in aqueous solution, commonly visualized in the blue bottle experiment, deplete molecular oxygen as long as a sacrificial reduction component is present in excess concentrations. We demonstrate that methylene blue in combination with reducing compounds such as β-mercaptoethylamine (MEA) can serve as fast and efficient oxygen scavenger. Efficient oxygen scavenging in aqueous solution is also possible with mere β-mercaptoethylamine at mM concentrations. We present kinetic parameters of the relevant reactions, pH-stability of the MB/MEA-oxygen scavenging system, and its application in single-molecule based super-resolution imaging.

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Supramolecular arrangement of 3,5-bis[methylene(dihydroxyphosphoryl)]benzoic acid and its complex with calcium

    NASA Astrophysics Data System (ADS)

    Przybył, Bartosz; Zoń, Jerzy; Janczak, Jan

    2013-09-01

    3,5-Bis[methylene(dihydroxyphosphoryl)]benzoic acid and its complex with calcium in the crystalline form were obtained. The 3,5-bis[methylene(dihydroxyphosphoryl)]benzoic acid crystallises as acetone monosolvate (1a) while its calcium complex as methanol disolvate (1b). The solvent molecules in the crystals are disordered. The 3,5-bis[methylene(dihydroxy-phosphoryl)]benzoic acid molecules in crystal 1a are interconnected via OH⋯O hydrogen bonds forming two-dimensional layers parallel to (1 0 0) plane. Within the layers there are present holes that occupied disordered acetone molecules. In 1b the calcium cation is surrounded by six singly deprotonated 3,5-bis[methylene(dihydroxyphosphoryl)]benzoic acid forming distorted octahedral environment. Each singly deprotonated 3,5-bis[methylene(dihydroxyphosphoryl)]benzoic acid links three calcium cations forming two-dimensional coordinating polymers parallel to (0 1 0) plane. The OH···O hydrogen bonds between the singly deprotonated 3,5-bis[methylene(dihydroxyphosphoryl)]benzoic acid ligands stabilize the two-dimensional polymers. Statistically disordered methanol molecules are located in the holes between the two-dimensional coordinating polymers and interact with them via OH···O hydrogen bonds.

  2. 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

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

    PubMed

    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 S

  4. Morphology and structure of microcapsules prepared by interfacial polycondensation of methylene bis(phenyl isocyanate) with hexamethylene diamine.

    PubMed

    Jabbari, E

    2001-01-01

    Polyurea microcapsules containing 2- chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl) acetamide as the active agent were prepared by the method of interfacial polycondensation with methylene bis(phenyl isocyanate) the multifunctional isocyanatae, hexamethylene diamine as the diamine, and anionic (SLS) as the emulsifying sodium lignin liinin the agent. The internal structure and morphology of the microcapsules were examined with transmission electron microscopy. The microcapsules had a micro-reservoir structure in which the wall extended well into the core and the active agent was accomodated by the micro-reservoirs, distributed uniformly throughout the entire volume of a microcapsule. Based on the observed morphology, permeability of the water soluble monomer in the polyurea film and its solubility in the oil phase have a significant effect on the morphology and microstructure of the microcapsules. The multivalent salt, calcium chloride, plays a significant role in stabilizing the microcapsule structure, by interacting with the anionic surfactant SLS, and physically crosslinks the SLS chains, by interacting with the negatively charged carboxylic and phenolic groups, with subsequent phase separation of the physically crosslinked chains to form a concentrated gel phase. This gel phase encompasses the microcapsule, increases the stability, and modifies its release behaviour.

  5. Catalytic reduction of methylene blue and Congo red dyes using green synthesized gold nanoparticles capped by salmalia malabarica gum

    NASA Astrophysics Data System (ADS)

    Ganapuram, Bhagavanth Reddy; Alle, Madhusudhan; Dadigala, Ramakrishna; Dasari, Ayodhya; Maragoni, Venkatesham; Guttena, Veerabhadram

    2015-08-01

    Stable gold nanoparticles (AuNPs) were synthesized using salmalia malabarica gum as both reducing and capping agent. It is a simple and eco-friendly green synthesis. The successful formation of AuNPs was confirmed by UV-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction and transmission electron microscopy (TEM). The synthesized AuNPs were characterized by a peak at 520-535 nm in the UV-Vis spectrum. The X-ray diffraction studies indicated that the resulting AuNPs were highly crystalline with face-centred cubic geometry. TEM studies showed that the average particle size of the synthesized AuNPs was 12 ± 2 nm. FTIR analysis revealed that -OH groups present in the gum matrix might be responsible for the reduction of Au+3 into AuNPs. The synthesized AuNPs exhibited good catalytic properties in the reduction of methylene blue and Congo red.

  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. A facile approach to prepare porous cup-stacked carbon nanotube with high performance in adsorption of methylene blue.

    PubMed

    Gong, Jiang; Liu, Jie; Jiang, Zhiwei; Wen, Xin; Mijowska, Ewa; Tang, Tao; Chen, Xuecheng

    2015-05-01

    Novel porous cup-stacked carbon nanotube (P-CSCNT) with special stacked morphology consisting of many truncated conical graphene layers was synthesized by KOH activating CSCNT from polypropylene. The morphology, microstructure, textural property, phase structure, surface element composition and thermal stability of P-CSCNT were investigated by field-emission scanning electron microscope, transmission electron microscope (TEM), high-resolution TEM, N2 sorption, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and thermal gravimetric analysis. A part of oblique graphitic layers were etched by KOH, and many holes with a diameter of several to a doze of nanometers connecting inner tube with outside were formed, which endowed P-CSCNT with high specific surface area (558.7 m(2)/g), large pore volume (1.993 cm(3)/g) and abundant surface functional groups. Subsequently, P-CSCNT was used for adsorption of methylene blue (MB) from wastewater. Langmuir model closely fitted the adsorption results, and the maximum adsorption capacity of P-CSCNT was as high as 319.1mg/g. This was ascribed to multiple adsorption mechanisms including pore filling, hydrogen bonding, π-π and electrostatic interactions. Pseudo second-order kinetic model was more valid to describe the adsorption behavior. Besides, P-CSCNT showed good recyclablity and reusability. These results demonstrated that P-CSCNT had potential application in wastewater treatment.

  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. 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.

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. Silver and zinc oxide nanostructures loaded on activated carbon as new adsorbents for removal of methylene green: a comparative study.

    PubMed

    Ghaedi, M; Karimi, H; Yousefi, F

    2014-09-01

    In this study, the removal of methylene green (MG) from aqueous solution based on two new adsorbents including silver nanoparticles and zinc oxide nanorods loaded on activated carbon (Ag-NP-AC and ZnO-NR-AC, respectively) has been carried out. The dependency of removal process to variables such as contact time, pH, amount of adsorbents, and initial MG concentration were examined and optimized. It was found that the maximum MG removal percentage was achieved at pH = 7.0 following stirring at 400 r min(-1) for 7 and 6 min for Ag-NP-AC and ZnO-NR-AC, respectively. Equilibrium data were well fitted with the Langmuir model having maximum adsorption capacity of 166.7 and 200 mg g(-1) for Ag-NP-AC and ZnO-NR-AC, respectively. Thermodynamic parameters of MG adsorption on Ag-NP-AC such as enthalpy and entropy changes, activation energy, sticking probability, and Gibbs free energy changes show the spontaneous and endothermic nature of the removal process. Among different conventional kinetic models, the pseudo second-order kinetics in addition to particle diffusion mechanism is the best and efficient model for the prediction and explanation of experimental data of MG adsorption onto both adsorbents.

  16. 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.

  17. 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.

  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. 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

  20. 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

  1. Evaluation of the developmental toxicity of alpha-methyl-3,4-methylene-dioxyhydrocinnamic aldehyde in rats.

    PubMed

    Api, Anne Marie; Lewis, Elise M; Hoberman, Alan M; Christian, Mildred S; Diener, Robert M

    2006-01-01

    The developmental toxicity of alpha-methyl-3,4-methylene-dioxyhydrocinnamic aldehyde (MMDHCA), a widely used fragrance ingredient, was evaluated for developmental toxicity in Sprague-Dawley rats (25/group; cesarean-sectioning identified 21 to 25 pregnant rats/group). Oral dosages of 0 (corn oil), 62, 125, or 250 mg/kg/day were administered by gavage on days 7 through 17 of gestation (GDs 7 through 17). Rats were observed for viability, clinical signs, body weights, and feed consumption. Necropsy and cesarean sectioning occurred on GD 21. Uteri were examined for number and distribution of implantations, live and dead fetuses, and early and late resorptions. Numbers of corpora lutea were also recorded. Fetuses were weighed and examined for gender, gross external changes, and soft tissue or skeletal alterations. Analysis of dosage preparations verified calculated dosages +/-10%. No deaths occurred. Excessive salivation occurred in all groups, but the incidence was increased at 250 mg/kg/day. The 250 mg/kg/day dosage also was associated with a significant increase in the incidences of a clear, red or yellow perioral and/or red perivaginal substance and significant reductions in mean feed consumption and body weight gains (11.6% and 7.4%, respectively) during the entire dosage period. No gross changes attributable to MMDHCA were observed at necropsy. Cesarean section or litter parameters, as well as fetal alterations, were not affected by MMDHCA at 250 mg/kg/day or either of the lower dosages tested. Based on these data, maternal and developmental no-observable-effect levels (NOAELs) of 125 and >250 mg/kg/day, respectively, were established for MMDHCA. It is concluded that MMDHCA is not a developmental toxicant in rats under the conditions of this study and dosing regimen.

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

    PubMed

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

    2010-05-15

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

  3. Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric α-Cr2O3(0001)

    DOE PAGES

    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

  4. 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.

  5. 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...

  6. 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...

  7. Modification of Hewlett-Packard Chemstation (G1034C version C.02.00 and G1701AA version C.02.00 and C.03.00) data analysis program for addition of automatic extracted ion chromatographic groups.

    PubMed

    Amick, G D

    1998-01-01

    A modification to data analysis macros to create "ion groups" and add a menu item to the data analysis menu bar is described. These "ion groups" consist of up to 10 ions for extracted ion chromatographs. The present manuscript describes modifications to yield a drop down menu in data analysis that contains user-defined names of groups (e.g., opiates, barbiturates, benzodiazepines) of ions that, when selected, will automatically perform extracted ion chromatographs with up to 10 ions in that group for the loaded datafile.

  8. Novel alkylimidazolium/vanadium pentoxide intercalation compounds with excellent adsorption performance for methylene blue

    SciTech Connect

    Kong Aiguo; Ding Yongjie; Wang Ping; Zhang Hengqiang; Yang Fan; Shan Yongkui

    2011-02-15

    Novel alkylimidazolium-intercalated V{sub 2}O{sub 5} compounds were synthesized by a redox reaction between iodide ion and V{sub 2}O{sub 5}. The X-ray photoelectron spectroscopy and the diffuse reflectance UV-vis spectrometry experiments reveal that the vanadium in the intercalated V{sub 2}O{sub 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{sub 2}O{sub 5} intercalation compounds have typical lamellar structure with different d{sub 100} interlayer spacing values and the special straw-like nanofiber morphology with the length of 0.5-10 {mu}m. Systematic investigation indicates that new intercalation compounds possess the extraordinary adsorption performance for methylene blue in an aqueous solution. -- Graphical abstract: The alkylimidazolium-intercalated V{sub 2}O{sub 5} compounds with special straw-like nanofiber morphology were synthesized by a redox reaction between iodide ion and V{sub 2}O{sub 5}, which show the excellent adsorption performance for methylene blue in an aqueous medium. Display Omitted Research highlights: {yields} Novel alkylimidazolium-intercalated V{sub 2}O{sub 5} compounds. {yields} A simple preparation method by a redox reaction between iodide ion in ionic liquid and V{sub 2}O{sub 5}. {yields} The excellent adsorption performance for methylene blue in an aqueous medium.

  9. 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.

  10. Silver-Catalyzed Cross-Coupling of Isocyanides and Active Methylene Compounds by a Radical Process.

    PubMed

    Liu, Jianquan; Liu, Zhenhua; Liao, Peiqiu; Zhang, Lin; Tu, Tao; Bi, Xihe

    2015-09-01

    Isocyanides are versatile building blocks, and have been extensively exploited in C-H functionalization reactions. However, transition-metal-catalyzed direct C-H functionalization reactions with isocyanides suffer from over-insertion of isocyanides. Reported herein is a radical coupling/isomerization strategy for the cross-coupling of isocyanides with active methylene compounds through silver-catalysis. The method solves the over-insertion issue and affords a variety of otherwise difficult to synthesize β-aminoenones and tricarbonylmethanes under base- and ligand-free conditions. This report presents a new fundamental C-C bond-forming reaction of two basic chemicals.

  11. 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.

  12. (99m)Tc-methylene diphosphonate bone scintigraphy findings in posttransplant distal limb syndrome.

    PubMed

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

    2014-07-01

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

  13. Mechanism of complexation of the phenothiazine dye methylene blue with fullerene C60

    NASA Astrophysics Data System (ADS)

    Buchelnikov, A. S.; Kostyukov, V. V.; Yevstigneev, M. P.; Prylutskyy, Yu. I.

    2013-04-01

    The complexation of fullerene C60 with the aromatic dye methylene blue (MB) in aqueous solution was studied. Spectrophotometric titration revealed a reasonably strong interaction between C60 and MB molecules with an equilibrium constant K = 2110 L/mol and the binding of up to five dye molecules with the surface of C60. The energy analysis of the MB-C60 system showed that the intermolecular and hydrophobic interactions were dominant in the energy profile of the complexation, and while the electrostatic factor played an insignificant role.

  14. 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.

  15. 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

  16. 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.

  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. 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

  19. 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

  20. Spectroscopic studies of the interactive model of methylene blue with DNA by means of β-cyclodextrin

    NASA Astrophysics Data System (ADS)

    Zhao, Guang-Chao; Zhu, Jun-Jie; Chen, Hong-Yuan

    1999-05-01

    The formation of the inclusion complex of methylene blue with β-cyclodextrin is studied by spectroscopic and electrochemical methods and the binding constant of the inclusion complex is 4.5×10 3 l mol -1. The interactive model of methylene blue with DNA has been investigated by means of the inclusion action of β-cyclodextrin. Through the changes of absorption and fluorescence spectra, the intrinsic binding constant ( k) of methylene blue with DNA and inclusion complex with DNA is obtained. In the case of 20 m mol l -1 Tris buffer solution (pH 7.2), their values are 1.53×10 5 l mol -1 and 9.98×10 4 l mol -1, respectively. The experimental results suggest that the inclusion complex does not decompose when it interacts with DNA. The binding number ( n) is 1 for both methylene blue and inclusion complex with DNA. According to the experimental results, it can be inferred that the interactive model of methylene blue with DNA is 'electrostatic binding'. This conclusion is able to explain the experimental phenomena clearly.

  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. Performance, kinetics, and equilibrium of methylene blue adsorption on biochar derived from eucalyptus saw dust modified with citric, tartaric, and acetic acids.

    PubMed

    Sun, Lei; Chen, Dongmei; Wan, Shungang; Yu, Zebin

    2015-12-01

    Biochar derived from eucalyptus saw dust modified with citric, tartaric, and acetic acids at low temperatures was utilized as adsorbent to remove methylene blue (MB) from aqueous solutions. Fourier transform infrared spectroscopy analysis showed that the carboxyl group was introduced on the biochar surface. Adsorption experiment data indicated that eucalyptus saw dust modified with citric acid showed higher MB adsorption efficiency than that modified with tartaric and acetic acids. Pseudo-second-order kinetics was the most suitable model for describing MB adsorption on biochar compared with pseudo-first-order, Elovich, and intraparticle diffusion models. The calculated values of ΔG(0) and ΔH(0) indicated the spontaneous and endothermic nature of the adsorption process. MB adsorption on biochar followed the Langmuir isotherm. The maximum adsorption capacities for eucalyptus saw dust modified with citric, tartaric, and acetic acids were 178.57, 99.01, and 29.94 mg g(-1), respectively, at 35°C.

  3. In vitro ALP and osteocalcin gene expression analysis and in vivo biocompatibility of N-methylene phosphonic chitosan nanofibers for bone regeneration.

    PubMed

    Datta, Pallab; Ghosh, Paulomi; Ghosh, Kuntal; Maity, Pritiprasanna; Samanta, Sintu Kumar; Ghosh, Sudip Kumar; Mohapatra, Pradeep Kumar Das; Chatterjee, Jyotirmoy; Dhara, Santanu

    2013-05-01

    Most polymeric nanofibers used for bone tissue engineering lack adequate functional groups for bioactivity. This study explores the potential of nanofibers of phosphate functionalized derivative of chitosan-N-methylene phosphonic chitosan (NMPC) for bone tissue engineering. Nanofibers were fabricated by electrospinning of NMPC/PVA blend solutions. NMPC/PVA nanofibers exhibited 172% higher viability of MG-63 cells compared to pure PVA nanofibers. ALP and Collagen type I genes revealed higher expression in NMPC nanofibers on day 3 whereas osteocalcin gene was expressed on day 7. In rabbit tibial defects, NMPC based electrospun graft showed presence of no adverse tissue reaction by histological examination while radiological examination suggested acceleration of bone healing by 300% compared to defects without any scaffold. Thus it is concluded NMPC based nanofibers may have potential for bone grafting applications. PMID:23802418

  4. 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

  5. Adsorption of methylene blue dye onto activated carbons based on agricultural by-products: equilibrium and kinetic studies.

    PubMed

    Ioannou, Z; Simitzis, J

    2013-01-01

    Mixtures of novolac resin and olive stone biomass (20/80 and 40/60 w/w) were cured, pyrolyzed up to 1,000 °C and activated with CO2 under a continuous flow operation (named N20B-cCa and N40B-cCa respectively). Commercial activated charcoal was similarly re-activated with CO2 and used for comparison reasons (AC-a). The characterization of these materials was performed by Fourier transform Infrared (FTIR) analysis and their specific surface area was determined according to DIN 66132. The materials were tested for their adsorption abilities at different temperatures (298, 333 K) and initial dye concentrations (0.01-0.35 g/L) using 1 L of methylene blue (MB) solution in 10 g of activated carbon. MB adsorption kinetic was also studied. The FTIR spectra of all activated carbons show absorption peaks which correspond to -OH, -CH, -C-O-C- groups and to aromatic ring. The presence of the absorption peak at about 1,400 cm(-1) for N20B-cCa, N40B-cCa indicates more acidic groups on them compared to the commercial AC-a. The specific surface area of N20B-cCa, N40B-cCa and AC-a has values equal to 352, 342 and 760 m(2)/g respectively. From the applied kinetic models, pseudo-second-order equation could best describe MB adsorption. Consequently, such adsorbents can be used as filters to adsorb dyes from wastewaters.

  6. Addition of cyclosporin-A to chemotherapy in secondary (post-MDS) AML in the elderly. A multicenter randomized trial of the Leukemia Working Group of the Hellenic Society of Hematology.

    PubMed

    Matsouka, P; Pagoni, M; Zikos, P; Giannakoulas, N; Apostolidis, I; Asprogeraka, T; Arvanitopoulou, E; Spanoudakis, E; Kotsianidis, I; Tsatalas, K; Papaioannou, M; Marinakis, T; Skandali, A; Viniou, N; Yataganas, X; Bakiri, M

    2006-04-01

    In elderly patients with secondary leukemia, poor therapeutic response and low overall survival have been attributed mainly to age and to the primary resistance of leukemic cells to chemotherapy. Modulation of resistance has been attempted in different studies, but the results have been contradictory. We conducted an open, randomized multicenter clinical trial involving patients more than 60 years old with secondary leukemia preceded by a myelodysplastic syndrome. The induction chemotherapy regimen included idarubicin, cytarabine, and etoposide (group A); randomization involved simultaneous administration of cyclosporin-A per os (group B). Fifty-five patients were evaluated, 26 in group A and 29 in group B. Overall complete remission was achieved in 40% of the patients, 27% vs 52% in groups A and B, respectively (p=0.01). Leukemia-free survival was more favorable in patients who received cyclosporin-A, 12 vs 7 months for groups B and A, respectively (p=0.03). In a follow up period of 30 months, 7 out of 55 patients (13%) were alive, 4 of whom were in complete remission. Five out of the 7 alive patients were randomized in group B and had received cyclosporin-A. Treatment failure was higher in group A [19 of 26 patients (73%)] than in group B with CsA [14 of 29 patients (48%)] (p<0.0001). Treatment-related toxicity/mortality was 13%. Modulation of drug resistance by CsA in elderly people suffering from secondary acute leukemia may improve the outcome of chemotherapy without increasing drug toxicity and treatment-related mortality.

  7. Alcohol-Induced C-N Bond Cleavage of Cyclometalated N-Heterocyclic Carbene Ligands with a Methylene-Linked Pendant Imidazolium Ring.

    PubMed

    Zhong, Wei; Fei, Zhaofu; Scopelliti, Rosario; Dyson, Paul J

    2016-08-16

    Reaction of the pentamethylcyclopentadienyl rhodium iodide dimer [Cp*RhI2 ]2 with 1,1'-diphenyl-3,3'-methylenediimidazolium diiodide in non-alcohol solvents, in the presence of base, led to the formation of bis-carbene complex [Cp*Rh(bis-NHC)I]I (bis-NHC=1,1'-diphenyl-4,4'-methylenediimidazoline-5,5'-diylidene). In contrast, when employing alcohols as the solvent in the same reaction, cleavage of a methylene C-N bond is observed, affording ether-functionalized (cyclometalated) carbene ligands coordinated to the metal center and the concomitant formation of complexes with a coordinated imidazole ligand. Studies employing other 1,1'-diimidazolium salts indicate that the cyclometalation step is a prerequisite for the activation/scission of the C-N bond and, based on additional experimental data, a SN 2 mechanism for the reaction is tentatively proposed. PMID:27412824

  8. 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.

  9. 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.

  10. "Directed" assembly of metallacalix[n]arenes with pyrimidine nucleobase ligands of low symmetry: interchanging metals in mixed-metal metallacalix[4]arenes and incorporating additional metals at the exocyclic groups.

    PubMed

    Khutia, Anupam; Sanz Miguel, Pablo J; Lippert, Bernhard

    2011-04-01

    The pyrimidine (pym) nucleobase cytosine (H(2)C) forms cyclic ring structures ("metallacalix[n]arenes") when treated with square-planar cis-a(2)M(II) entities (M=Pt, Pd; a=NH(3) or a(2)=diamine). The number of possible linkage isomers for a given n and the number of possible rotamers can be substantially reduced if a "directed" approach is pursued. Hence, two cytosine ligands are bonded in a defined way to a kinetically robust platinum corner stone. In the accompanying paper (Part I: A. Khutia, P. J. Sanz Miguel, B. Lippert, Chem. Eur. J. 2010, 17, DOI: 10.1002/chem.2010002722) we have demonstrated this principle by allowing cis-[Pta(2)(H(2)C-N3)(2)](2+) to react with (en)Pd(II) to give cycles of (N1,N3⋅N3,N1▪)(x) (with x=2 or 3; ⋅ represents Pt(II) and ▪ represents Pd(II)). In an extension of this work we have now prepared cis-[Pta(2)(HC-N1)(2)] (1; HC=monoanion of cytosine) and treated it with (bpy)Pd(II) (bpy=2,2'-bipyridine) to give the Pt(2) Pd(2) cycle cis-[{Pt(NH(3))(2)(N1-HC-N3)(2)Pd(bpy)}(2)](NO(3))(4) ⋅13H(2)O (5) with the coordination sites of the metals inverted; hence, platinum is bonded to N1 and palladium is bonded to N3 sites. Again, not only the expected single linkage isomer is formed, but at the same time the solid-state structure and (1)H NMR spectroscopy reveal the preferential occurrence of a single rotamer (1,3-alternate). The addition of (bpy)Pd(II) to 5 led to the formation of Pd(6) Pt(2) complex 6 in which the exocyclic N4H(2) groups of the cytosine ligands have undergone deprotonation and chelate four more (bpy)Pd(II) entities through the O2 and N4H sites. With a large excess of (bpy)Pd(II) over 5 (4:1), cis-(NH(3))(2) Pt(II) is eventually substituted by (bpy)Pd(II) to give the Pd(8) complex 7. In both 6 and 7 stacks of three (bpy)Pd(II) entities occur. The linkage isomer of 5,cis-[{Pt(NH(3))(2)(N3-HC-N1)(2)Pd(bpy)}(2)](NO(3))(4) ⋅9H(2)O (8), has been structurally characterized and the two complexes compared. The acid

  11. In Situ XANES Study of CuO/TiO2 Thin Films During Photodegradation of Methylene Blue

    NASA Astrophysics Data System (ADS)

    Hsiung, Tung Li; Wang, H. Paul; Wei, Yu-Ling

    2007-02-01

    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 Å during photocatalytic degradation of methylene blue.

  12. 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.

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

    PubMed

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

    2014-01-01

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

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

    PubMed

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

    2015-11-30

    Sarcocystosis in meat-producing animals is a major cause of reduced productivity in many countries, especially those that rely on agriculture. Although several diagnostic methods are available to detect sarcocystosis, many are too time-consuming for routine use in abattoirs and meat inspection centers, where large numbers of samples need to be tested. This study aimed to compare the sensitivity of the methylene blue tissue preparation, unstained tissue preparation and nested PCR in the detection of sarcocysts in tissue samples. Approximately three-fold more sarcocysts were detected in methylene blue-stained tissue compared to unstained controls (McNemar's test: P<0.01). Test sensitivity was comparable to that of the gold standard for sarcocyst detection, nested polymerase chain reaction. These results suggest that methylene blue can be used in tissue compression as a rapid, safe, and inexpensive technique for the detection of ruminant sarcocystosis in abattoirs. PMID:26455572

  15. Effect of methylene blue-mediated photodynamic therapy for treatment of basal cell carcinoma.

    PubMed

    Samy, Nevien A; Salah, Manal M; Ali, Maha F; Sadek, Ahmed M

    2015-01-01

    Photodynamic therapy (PDT) is regarded as a treatment option for basal cell carcinoma (BCC). The aim of this study is to investigate the efficacy of methylene blue (MB)-based PDT in patients suffering from nodular or ulcerative BCCs. This study is a prospective clinical trial with a 6-months follow-up. The study setting is at the Dermatology Clinic at NILES, Cairo University, Egypt. Seventeen patients complaining of nodular BCC (nBCC) and three patients complaining of ulcerative BCC (uBCC) were taken as samples. Methylene blue, the photosensitizer, was prepared in two different formulas: liposomal-loaded MB (LMB) was prepared and formulated in hydrogel (MB 0.2%) to be used topically alone for treating BCCs <2 cm in diameter or to be combined with intralesional injection (ILI) of free MB 2% aqueous solution for treating BCCs ≥2 cm in diameter. A session was performed every 2 weeks until complete response (CR) of the lesion or for a maximum of six sessions. Clinical assessments of clinical improvement, dermatological photography, monthly follow-up visits for 6 months, and skin biopsy after 3 months of follow-up to confirm the response, recurrence, or both in cases in which the clinical evaluation was ambiguous. Seventeen patients of the 20 completed the study, 11 patients achieved CR with very good cosmetic outcome, photosensitizer tolerance, and minimal reported side effects. MB is a cheap promising alternative photosensitizer for PDT of nBCC.

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

    NASA Astrophysics Data System (ADS)

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

    2008-07-01

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

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

    PubMed

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

    2014-01-30

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

  18. Removal of methylene blue from aqueous solution by adsorption onto pineapple leaf powder.

    PubMed

    Weng, Chih-Huang; Lin, Yao-Tung; Tzeng, Tai-Wei

    2009-10-15

    The ability of an unconventional bio-adsorbent, pineapple leaf powder (PLP) for the adsorption of methylene blue (MB) from aqueous solution was studied. It was observed that intra-particle diffusion was involved in the adsorption process and that the kinetic data fitted well with a pseudo-second-order equation. Fitting parameters revealed that the rate of adsorption increased with decrease in dye concentration and decrease in ionic strength while the mixing speed did not have a significant effect on adsorption. The adsorption was favorable at higher pH and lower temperature, and the equilibrium data were well fitted by the Langmuir isotherm. The maximum adsorption capacity varied from 4.68 x 10(-4) to 9.28 x 10(-4)mol/g when pH increases from 3.5 to 9.5. Thermodynamic parameters suggest that the adsorption is a typical physical process, spontaneous, and exothermic in nature. The results revealed that this agricultural waste has potential to be used as an economical adsorbent for the removal of methylene blue from aqueous solution.

  19. A Possible Phenomenon of Persistence in Pseudomonas aeruginosa Treated with Methylene Blue and Red Light.

    PubMed

    Forte Giacobone, Ana Florencia; Ruiz Gale, Maria Fernanda; Hogert, Elsa Noemí; Oppezzo, Oscar Juan

    2016-09-01

    Planktonic Pseudomonas aeruginosa cells harvested in stationary phase were exposed to red light in the presence of methylene blue to study the potential occurrence of persistence in bacterial populations submitted to photodynamic antimicrobial therapy. Survival curves revealed the existence of small subpopulations of cells exhibiting increased ability to tolerate the treatment. These subpopulations were detected even using high concentrations of photosensitizer, whether added in a single step or following a fractionated scheme, and when the irradiation medium was modified to delay the photodecomposition of methylene blue. When cells grown from survivors to the treatment were cultured and exposed to red light and dye, their responses were similar to that of the original strain. These results exclude exhaustion of the photosensitizer and selection of resistant mutants as explanations for the features of the survival curves. Cells able to tolerate the treatment were found even when radiation was imparted at a high-dose rate. They exhibit a response typical of persisters, which tolerate antimicrobial agents due to transient and reversible changes in their phenotype, suggesting that persistence is a factor to consider upon evaluating the efficacy of photodynamic antimicrobial therapy.

  20. 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.

  1. 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

  2. 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

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

    NASA Astrophysics Data System (ADS)

    Rezaei, Mostafa; Salem, Shiva

    2016-10-01

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

  4. 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

  5. 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.

  6. 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.

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

    PubMed

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

    2014-01-01

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

  8. 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

  9. Removal of methylene blue from aqueous solution by adsorption onto pineapple leaf powder.

    PubMed

    Weng, Chih-Huang; Lin, Yao-Tung; Tzeng, Tai-Wei

    2009-10-15

    The ability of an unconventional bio-adsorbent, pineapple leaf powder (PLP) for the adsorption of methylene blue (MB) from aqueous solution was studied. It was observed that intra-particle diffusion was involved in the adsorption process and that the kinetic data fitted well with a pseudo-second-order equation. Fitting parameters revealed that the rate of adsorption increased with decrease in dye concentration and decrease in ionic strength while the mixing speed did not have a significant effect on adsorption. The adsorption was favorable at higher pH and lower temperature, and the equilibrium data were well fitted by the Langmuir isotherm. The maximum adsorption capacity varied from 4.68 x 10(-4) to 9.28 x 10(-4)mol/g when pH increases from 3.5 to 9.5. Thermodynamic parameters suggest that the adsorption is a typical physical process, spontaneous, and exothermic in nature. The results revealed that this agricultural waste has potential to be used as an economical adsorbent for the removal of methylene blue from aqueous solution. PMID:19447547

  10. 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.

  11. Sarks as additional fermions

    NASA Astrophysics Data System (ADS)

    Agrawal, Jyoti; Frampton, Paul H.; Jack Ng, Y.; Nishino, Hitoshi; Yasuda, Osamu

    1991-03-01

    An extension of the standard model is proposed. The gauge group is SU(2) X ⊗ SU(3) C ⊗ SU(2) S ⊗ U(1) Q, where all gauge symmetries are unbroken. The colour and electric charge are combined with SU(2) S which becomes strongly coupled at approximately 500 GeV and binds preons to form fermionic and vector bound states. The usual quarks and leptons are singlets under SU(2) X but additional fermions, called sarks. transform under it and the electroweak group. The present model explains why no more than three light quark-lepton families can exist. Neutral sark baryons, called narks, are candidates for the cosmological dark matter having the characteristics designed for WIMPS. Further phenomenological implications of sarks are analyzed i including electron-positron annihilation. Z 0 decay, flavor-changing neutral currents. baryon-number non-conservation, sarkonium and the neutron electric dipole moment.

  12. 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…

  13. 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

  14. 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

  15. Two inorganic-organic hybrid materials based on polyoxometalate anions and methylene blue: Preparations, crystal structures and properties

    SciTech Connect

    Nie Shanshan; Zhang Yaobin; Liu Bin; Li Zuoxi; Hu Huaiming; Xue Ganglin; Fu Feng; Wang Jiwu

    2010-12-15

    Two novel inorganic-organic hybrid materials based on an organic dye cation methylene blue (MB) and Lindqvist-type POM polyanions, [C{sub 22}H{sub 18}N{sub 3}S]{sub 2}Mo{sub 6}O{sub 19} 2DMF (1) and [C{sub 22}H{sub 18}N{sub 3}S]{sub 2}W{sub 6}O{sub 19} 2DMF (2) were synthesized under ambient conditions and characterized by CV, IR spectroscopy, solid diffuse reflectance spectrum, UV-vis spectra in DMF solution, luminescent spectrum and single crystal X-ray diffraction. Crystallographic data reveal that compounds 1 and 2 are isostructural and both crystallize in the triclinic space group P1-bar . Their crystal structures present that the layers of organic molecules and inorganic anions array alternatively, and there exist strong {pi}...{pi} stacking interactions between dimeric MB cations and near distance interactions among organic dye cations, Lindqvist-type POM polyanions and DMF molecules. The solid diffuse reflectance spectra and UV-vis spectra in DMF solution appear new absorption bands ascribed to the charge-transfer transition between the cationic MB donor and the POM acceptors. Studies of the photoluminescent properties show that the formation of 1 and 2 lead to the fluorescence quenching of starting materials. -- Graphical abstract: Their crystal structures present that the layers of organic molecules and inorganic anions array alternatively, and there exist strong {pi}...{pi} stacking interactions between dimeric MB cations. Display Omitted

  16. Highly efficient hydrophosphonylation of aldehydes and unactivated ketones catalyzed by methylene-linked pyrrolyl rare earth metal amido complexes.

    PubMed

    Zhou, Shuangliu; Wu, Zhangshuan; Rong, Jiewei; Wang, Shaowu; Yang, Gaosheng; Zhu, Xiancui; Zhang, Lijun

    2012-02-27

    A series of rare earth metal amido complexes bearing methylene-linked pyrrolyl-amido ligands were prepared through silylamine elimination reactions and displayed high catalytic activities in hydrophosphonylations of aldehydes and unactivated ketones under solvent-free conditions for liquid substrates. Treatment of [(Me(3)Si)(2)N](3)Ln(μ-Cl)Li(THF)(3) with 2-(2,6-Me(2)C(6)H(3)NHCH(2))C(4)H(3)NH (1, 1 equiv) in toluene afforded the corresponding trivalent rare earth metal amides of formula {(μ-η(5):η(1)):η(1)-2-[(2,6-Me(2)C(6)H(3))NCH(2)](C(4)H(3)N)LnN(SiMe(3))(2)}(2) [Ln=Y (2), Nd (3), Sm (4), Dy (5), Yb (6)] in moderate to good yields. All compounds were fully characterized by spectroscopic methods and elemental analyses. The yttrium complex was also characterized by (1)H NMR spectroscopic analyses. The structures of complexes 2, 3, 4, and 6 were determined by single-crystal X-ray analyses. Study of the catalytic activities of the complexes showed that these rare earth metal amido complexes were excellent catalysts for hydrophosphonylations of aldehydes and unactivated ketones. The catalyzed reactions between diethyl phosphite and aldehydes in the presence of the rare earth metal amido complexes (0.1 mol%) afforded the products in high yields (up to 99%) at room temperature in short times of 5 to 10 min. Furthermore, the catalytic addition of diethyl phosphite to unactivated ketones also afforded the products in high yields of up to 99% with employment of low loadings (0.1 to 0.5 mol%) of the rare earth metal amido complexes at room temperature in short times of 20 min. The system works well for a wide range of unactivated aliphatic, aromatic or heteroaromatic ketones, especially for substituted benzophenones, giving the corresponding α-hydroxy diaryl phosphonates in moderate to high yields.

  17. SIRT1 activation by methylene blue, a repurposed drug, leads to AMPK-mediated inhibition of steatosis and steatohepatitis.

    PubMed

    Shin, Seo Young; Kim, Tae Hyun; Wu, Hongmin; Choi, Young Hee; Kim, Sang Geon

    2014-03-15

    Sirtuins maintain energy balance. Particularly, sirtuin 1 (SIRT1) activation mimics calorie restriction and nutrient utilization. However, no medications are available for the up-regulation of SIRT1. Methylene blue (MB) had been in clinical trials for the treatment of neurological diseases. This study investigated the effect of MB on sirtuin expression in association with the treatment of steatosis and steatohepatitis, and explored the underlying basis. The effects of MB on mitochondrial function, molecular markers, pharmacokinetics, and histopathology were assessed using hepatocyte and/or mouse models. Immunoblotting, PCR and reporter assays were done for molecular experiments. After oral administration, MB was well distributed in the liver. MB treatment increased NAD(+)/NADH ratio in hepatocytes. Of the major forms, MB treatment up-regulated SIRT1, and thereby decreased PGC-1α acetylation. Consistently, hepatic mitochondrial DNA contents and oxygen consumption rates were enhanced. MB treatment also notably activated AMPK, CPT-1 and PPARα: the AMPK activation relied on SIRT1. Activation of LXRα and the induction of SREBP-1c and its target genes by T0901317 were diminished by MB. In addition, MB treatment antagonized the ability of palmitate to acetylate PGC-1α, and increase SERBP-1c, FAS, and ACC levels. In mice fed on a high-fat diet for 8 weeks, MB treatment inhibited excessive hepatic fat accumulation and steatohepatitis. The ability of MB to activate SIRT1 promotes mitochondrial biogenesis and oxygen consumption and activates AMPK, contributing to anti-lipogenesis in the liver. Our results provide new information on the potential use of MB for the treatment of steatosis and steatohepatitis.

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

    PubMed

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

    2015-01-01

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

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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.

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 1,4-Butanediol, polymer with substituted alkane and substituted methylene biscarbomonocycle, 2-hydroxyalkyl acrylate-blocked (generic). 721.10626 Section 721.10626 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES...

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

    PubMed

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

    2014-07-01

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

  6. 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...

  7. Desorption and photodegradation of methylene blue from modified sugarcane bagasse surface by acid TiO2 hydrosol

    NASA Astrophysics Data System (ADS)

    Yu, Jun-Xia; Chi, Ru-An; Guo, Jia; Zhang, Yue-Fei; Xu, Zhi-Gao; Xiao, Chun-Qiao

    2012-02-01

    Waste sugarcane bagasse (SCB) was modified by pyromellitic dianhydride to improve its adsorption capacity for cationic dyes. Results showed that the adsorption capacity of the modified SCB for methylene blue was 564 mg g-1, which was about 12 times than that obtained on the unmodified SCB. Methylene blue loaded modified SCB was regenerated by a self-clean eluent: TiO2 hydrosol with pH ranged from 1 to 4, and HNO3 solution with the same pH range was tested at the same time for comparison. Results showed that desorption kinetics of methylene blue in the hydrosol systems fit two-step kinetic model and controlled mainly by the slow step. As a self-clean eluent, acid hydrosol could firstly desorb and then photodegrade methylene blue under sunlight irradiation. After five desorption-photodegradation cycles, 78.3% of the absorbed dyes could be desorbed by using hydrosol (pH 2) as eluent. The hydrosol could be continuously used in desorption and photodegradation process, which would economize large volume of the eluent and moreover it would not bring secondary pollution.

  8. 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.

  9. Epidemic of asthma in a wood products plant using methylene diphenyl diisocyanate.

    PubMed

    Woellner, R C; Hall, S; Greaves, I; Schoenwetter, W F

    1997-01-01

    Eighteen employees with lower respiratory symptoms later confirmed to be occupational asthma were referred for evaluation. All were employees of a single wood products plant using heated methylene diphenyl diisocyanate (MDI) in the manufacture of a synthetic wood product. Of the 18, 15 had no prior airway symptoms or other known bronchial injury, and 16 had positive methacholine bronchial provocation tests. All cases occurred during a 2.5-year period after exposure to a new manufacturing process using steam-heated MDI resin in a new manufacturing facility. Initially, employees developed symptoms related to the start-up process in the plant, with possible higher MDI exposures and probable higher resin temperatures. Later, most employees who developed new symptoms worked in areas of the plant where they were exposed mostly to heated boards. This suggests MDI sensitization arising at lower temperatures than previously considered likely for this substance.

  10. Comparative adsorption isotherms and modeling of methylene blue onto activated carbons

    NASA Astrophysics Data System (ADS)

    Belhachemi, Meriem; Addoun, Fatima

    2011-12-01

    The adsorption of methylene blue (MB) on activated carbons prepared from date stones with different degree of activation has been investigated. Equilibrium adsorption data of MB was carried out at 298 K. Four isotherm models (Freundlich, Langmuir, Redlich-Peterson and Sips) were tested for modeling the adsorption isotherms by nonlinear method. The three-parameter equations (Redlich-Peterson and Sips) showed more applicability than the two-parameter equations (Freundlich and Langmuir), which can be explained by the fact that these have three adjustable parameters. The best fit was achieved with the Redlich-Peterson equation according to the high value of correlation coefficient. All the samples were capable of retaining the MB, with the best result being reached by the sample with higher burn-off. Date stones activated carbon showed high adsorption capacity of 460 mg/g, calculated from the Sips isotherm model.

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

    PubMed

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

    2013-12-01

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

  12. Adsorption characteristics of methylene blue onto agricultural wastes lotus leaf in bath and column modes.

    PubMed

    Han, Xiuli; Wang, Wei; Ma, Xiaojian

    2011-01-01

    The adsorption potential of lotus leaf to remove methylene blue (MB) from aqueous solution was investigated in batch and fixed-bed column experiments. Langmuir, Freundlich, Temkin and Koble-Corrigan isotherm models were employed to discuss the adsorption behavior. The results of analysis indicated that the equilibrium data were perfectly represented by Temkin isotherm and the Langmuir saturation adsorption capacity of lotus leaf was found to be 239.6 mg g(-1) at 303 K. In fixed-bed column experiments, the effects of flow rate, influent concentration and bed height on the breakthrough characteristics of adsorption were discussed. The Thomas and the bed-depth/service time (BDST) models were applied to the column experimental data to determine the characteristic parameters of the column adsorption. The two models were found to be suitable to describe the dynamic behavior of MB adsorbed onto the lotus leaf powder column.

  13. Preparation of Fe3O4 Nanoparticles and Removal of Methylene Blue through Adsorption

    NASA Astrophysics Data System (ADS)

    Trujillo Hernandez, J. S.; Aragón Muriel, A.; Tabares, J. A.; Pérez Alcázar, G. A.; Bolaños, A.

    2015-07-01

    In this work, we studied the catalytic activity, structural properties, and behavior of a Fe3O4 magnetic system. The Fe3O4 nanoparticles were prepared by the thermal decomposition method. X-ray diffraction confirmed the presence of a structural Fe3O4 phase, where acicular shape of the grains is shown. Transmission Mossbauer spectroscopy showed a wide distribution of particle sizes at room temperature, some of these present superparamagnetic behavior and are responsible of paramagnetic sites. The hysteresis loops obtained by the use of a vibrating sample magnetometer showed that these nanoparticles exhibit superparamagnetic behavior. However, the cycles present a significant contribution from a ferrimagnetic component at 2 K, which agrees with Mossbauer results. Through scanning electron microscopy, a tendency to the agglomeration of nanoparticles was observed. Nanoparticle activity in the degradation of methylene blue (MB) was studied through fluorescence spectroscopy, finding dye adsorption properties.

  14. Study on the methylene blue adsorption from wastewaters by pore-expanded calcium fluoride sludge adsorbent.

    PubMed

    Hong, Junming; Lin, Bing; Hong, Gui-Bing; Chang, Chang-Tang

    2014-04-01

    The adsorption of methylene blue (MB) onto pore-expanded calcium fluoride sludge (ECF) by the batch adsorption technique was investigated. The results showed that the adsorption capacity increased with increasing MB concentration but decreased as pH was increased. In order to investigate the adsorption mechanisms, three simplified isotherm models and kinetic models were used in this study. The best-fit adsorption isotherm was achieved with the Temkin model. Furthermore, the pseudo-second-order kinetic model agreed very well with the dynamical behavior for the adsorption of MB onto ECF. Thermodynamic studies revealed that the adsorption process of MB onto ECF was spontaneous and exothermic. The results indicated that ECF adsorbed MB efficiently and could be used as a waste adsorbent for the removal of cationic dyes in wastewater treatment.

  15. 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.

  16. Equilibrium models and kinetic for the adsorption of methylene blue on Co-hectorites.

    PubMed

    Ma, Jun; Jia, Yong-Zhong; Jing, Yan; Sun, Jin-He; Yao, Ying; Wang, Xiao-Hua

    2010-03-15

    The adsorption of methylene blue (MB) onto the surface of cobalt doping hectorite (Co-hectorite) was systematically studied. The physical properties of Co-hectorites were investigated, where characterizations were carried out by X-ray diffraction (XRD) and Electron Diffraction Spectrum (EDS) techniques, and morphology was examined by nitrogen adsorption. The sample with a Co content 5% (m/m) had a higher specific surface area than other Co-hectorites. The pore diameters were distributed between 2.5 and 5.0 nm. The adsorption results revealed that Co-hectorite surfaces possessed effective interactions with MB and bases, and greatest adsorption capacity achieved with Co content 5%, where the best-fit isotherm model was the Langmuir adsorption model. Kinetic studies were fitted to the pseudo-second-order kinetic model. The intraparticle diffusion was not the rate-limiting step for the whole reaction.

  17. Methylene blue adsorption from aqueous solution by activated carbon: effect of acidic and alkaline solution treatments.

    PubMed

    Ijagbemi, Christianah O; Chun, Ji I; Han, Da H; Cho, Hye Y; O, Se J; Kim, Dong S

    2010-01-01

    The removal of Methylene Blue (MB) from aqueous solution using activated carbon (AC) has been investigated. Adsorption experiments were conducted and the maximum adsorption capacity was determined. The effect of experimental parameters such as pH, dye concentration and temperature were studied on the adsorption process. Equilibrium data were mathematically modeled using the Langmuir and Freundlich adsorption models to describe the equilibrium isotherms at different dye concentrations and temperature. Parameters of best-fit model were calculated and discussed. To understand the mechanism of adsorption, kinetic models were employed to follow the adsorption processes; the pseudo-first-order best described the adsorption of MB onto AC. It was found that pH plays a major role in the adsorption process; adsorption capacity was influenced by the physical and surface chemical properties of carbon and the pH of the solution. 99.0% MB removal was achieved at equilibrium.

  18. Adsorptive performance for methylene blue of magnetic Ni@activated carbon nanocomposites

    NASA Astrophysics Data System (ADS)

    Wang, Panfeng; Xu, Jingcai; Zhang, Beibei; Li, Jing; Jin, Hongxiao; Jin, Dingfeng; Peng, Xiaoling; Hong, Bo; Gong, Jie; Ge, Hongliang; Wang, Xinqing

    2015-11-01

    Owing to the unique microporous structure and high specific surface area, activated carbon (AC) can act as a good candidate for functional materials. In this paper, Ni@AC magnetic nanocomposites with excellent magnetic response are synthesized by the hydrothermal method. All Ni@AC nanocomposites present ferromagnetism and Ni nanoparticles exist in the pores of AC. The saturation magnetization (Ms) increases with the increasing content of Ni, while the specific surface area and pore volume decrease. The S-50 sample possesses the parameters of the specific surface area of 1156.8 m2 ṡ g-1 and Ms of 3.5 emu/g. Furthermore, the methylene blue (MB) removal analysis indicates that 99% MB can be adsorbed in 50 min. The as-prepared Ni@AC nanocomposites present good adsorptive capacity of MB and can be separated easily from water by magnetic separation technique.

  19. 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.

  20. A Silver Nanoparticle-Modified Evanescent Field Optical Fiber Sensor for Methylene Blue Detection

    PubMed Central

    Luo, Ji; Yao, Jun; Lu, Yonggang; Ma, Wenying; Zhuang, Xuye

    2013-01-01

    A silver nanoparticle-modified evanescent field optical fiber sensor based on a MEMS microchannel chip has been successfully fabricated. Experimental results show that the sensor response decreases linearly with increasing concentration of analyte. Over a range of methylene blue concentrations from 0 to 0.4 μmol/mL, the sensor response is linear (R = 0.9496). A concentration variation of 0.1 μmol/mL can cause an absorbance change of 0.402 dB. Moreover, the optical responses of the same sensing fiber without decoration and modified with silver nanoparticles have also been compared. It can be observed that the output intensity of the Ag nanoparticle-modified sensor is enhanced and the sensitivity is higher. Meanwhile, the absorbance spectra are found to be more sensitive to concentration changes compared to the spectra of the peak wavelength. PMID:23519353

  1. Near-infrared fluorescence imaging of a solitary fibrous tumor of the pancreas using methylene blue.

    PubMed

    van der Vorst, Joost R; Vahrmeijer, Alexander L; Hutteman, Merlijn; Bosse, Tjalling; Smit, Vincent T H B M; van de Velde, Cornelis J H; Frangioni, John V; Bonsing, Bert A

    2012-07-27

    A 67-year-old female presented with unexplained abdominal pain. A contrast-enhanced computed tomography scan of the abdomen incidentally revealed a mass in the uncinate process of the pancreas. This mass was resected and based on histopathological findings, diagnosed as a solitary fibrous tumor (SFT) of the pancreas. A SFT is an extremely rare benign mesenchymal tumor that in 65% of cases affects the visceral pleura but can also affect extra-pleural sites. The intraoperative demarcation of pancreatic tumors, such as SFTs, can be challenging. In this report, the first clear intraoperative identification of a SFT of the pancreas in a human was shown using near-infrared fluorescence and methylene blue.

  2. 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

  3. Adsorption of methylene blue onto jute fiber carbon: kinetics and equilibrium studies.

    PubMed

    Senthilkumaar, S; Varadarajan, P R; Porkodi, K; Subbhuraam, C V

    2005-04-01

    Jute fiber obtained from the stem of a plant was used to prepare activated carbon using phosphoric acid. Feasibility of employing this jute fiber activated carbon (JFC) for the removal of Methylene blue (MB) from aqueous solution was investigated. The adsorption of MB on JFC has found to dependent on contact time, MB concentration and pH. Experimental result follows Langmuir isotherm model and the capacity was found to be 225.64 mg/g. The optimum pH for the MB removal was found to be 5-10. The kinetic data obtained at different concentrations have been analyzed using a pseudo-first-order, pseudo-second-order equation, intraparticle diffusion and Elovich equation. Among the kinetic models studied, the intraparticle diffusion was the best applicable model to describe the adsorption of MB onto JFC.

  4. 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.

  5. Report: Simultaneous determination of naphazoline hydrochloride, chlorpheniramine maleate and methylene blue in their ternary mixture.

    PubMed

    Ali, Nouruddin Wageih; Hegazy, Maha Ahmad; Abdelkawy, Mohamad; Abdelfatah, Rehab Magdy

    2013-05-01

    Validated spectrophotometric and chemometric methods were developed for determination of Naphazoline Hydrochloride (NAP), Chlorpheniramine maleate (CLO) and Methylene blue (MB) in their ternary mixture. Method A was a spectrophotometric method, where NAP and MB were determined using second derivative (D²) spectrophoto metric method using the peak amplitudes at 299 nm and 337 nm for NAP and MB respectively , while CLO was determined using second derivative ratio (DD²) spectrophotometric method using the peak amplitude at 276.6 nm. Method B used the chemometric techniques; principal component regression (PCR) and partial least squares (PLS) for determination of NAP, CLO and MB using the information contained in the absorption spectra of their ternary mixture solutions. The proposed methods have been successfully applied for the analysis of NAP, CLO and MB in their pharmaceutical formulation and the obtained results were statistically compared with the reported methods.

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

    PubMed

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

    2013-12-01

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

  7. 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.

  8. Photocatalytic activity of TiO2 nanomaterials for methylene blue dye degradation

    NASA Astrophysics Data System (ADS)

    Lee, Deuk Yong; Son, Siwon; Jeon, Min-Seok; Lee, Myung-Hyun; Kim, Bae-Yeon

    2016-04-01

    TiO2 nanomaterials were prepared by a sol-gel derived electrospinning, calcination from 500°C to 650°C, and subsequent mechanical grinding to investigate the effect of calcination temperature on crystal structure, crystallinity, and photocatalytic activity of methylene blue (MB). XRD results indicated that TiO2 nanorods calcined at 500°C is composed of anatase TiO2 only. However, mixed crystals of anatase and rutile were observed for TiO2 calcined above 550°C. Higher MB degradation was found for the TiO2 nanorods calcined at 550°C probably due to the mixed crystals and larger surface area. However, the improved photocatalytic activity was achieved for TiO2 nanotube due to the synergic combinations of mixed crystals, larger specific surface area, and light trapping effect.

  9. Citric acid modified kenaf core fibres for removal of methylene blue from aqueous solution.

    PubMed

    Sajab, Mohd Shaiful; Chia, Chin Hua; Zakaria, Sarani; Jani, Saad Mohd; Ayob, Mohd Khan; Chee, Kah Leong; Khiew, Poi Sim; Chiu, Wee Siong

    2011-08-01

    Chemically modified kenaf core fibres were prepared via esterification in the presence of citric acid (CA). The adsorption kinetics and isotherm studies were carried out under different conditions to examine the adsorption efficiency of CA-treated kenaf core fibres towards methylene blue (MB). The adsorption capacity of the kenaf core fibres increased significantly after the citric acid treatment. The values of the correlation coefficients indicated that the Langmuir isotherm fitted the experimental data better than the Freundlich isotherm. The maximum adsorption capacity of the CA-treated kenaf core fibres was found to be 131.6mg/g at 60°C. Kinetic models, pseudo-first-order, pseudo-second-order and intraparticle diffusion, were employed to describe the adsorption mechanism. The kinetic data were found to fit pseudo-second-order model equation as compared to pseudo-first-order model. The adsorption of MB onto the CA-treated kenaf core fibres was spontaneous and endothermic.

  10. Isolation of a strain of Agrobacterium tumefaciens (Rhizobium radiobacter) utilizing methylene urea (ureaformaldehyde) as nitrogen source.

    PubMed

    Koivunen, Marja E; Morisseau, Christophe; Horwath, William R; Hammock, Bruce D

    2004-03-01

    Methylene ureas (MU) are slow-release nitrogen fertilizers degraded in soil by microbial enzymatic activity. Improved utilization of MU in agricultural production requires more knowledge about the organisms and enzymes responsible for its degradation. A Gram-negative, MU-degrading organism was isolated from a soil in Sacramento Valley, California. The bacterium was identified as Agrobacterium tumefaciens (recently also known as Rhizobium radiobacter) using both genotypic and phenotypic characterization. The pathogenic nature of the organism was confirmed by a bioassay on carrot disks. The MU-hydrolyzing enzyme (MUase) was intracellular and was induced by using MU as a sole source of nitrogen. The bacterial growth was optimized in NH4Cl, urea, or peptone, whereas the production and specific activity of MUase were maximized with either NH4Cl or urea as a nitrogen source. The result has a practical significance, demonstrating a potential to select for this plant pathogen in soils fertilized with MU.

  11. 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.

  12. 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

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

    PubMed

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

    2013-08-01

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

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

    PubMed

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

    2004-06-18

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

  15. 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.

  16. 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.

  17. 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

  18. Conformational analysis of oleandomycin and its 8-methylene-9-oxime derivative by NMR and molecular modelling.

    PubMed

    Novak, Predrag; Tomisić, Zrinka Banić; Tepes, Predrag; Lazarevski, Gorjana; Plavec, Janez; Turkalj, Gordana

    2005-01-01

    Conformations of the 14-membered macrolide antibiotic oleandomycin and its 8-methylene-9-oxime derivative were determined in various solvents. The experimental NMR data--coupling constants and NOE contacts--were compared with the results of molecular modelling--molecular mechanics calculations and molecular dynamics simulations. The conformational changes, on the right-hand side of the 14-membered ring, affected mostly the 3JH2,H3 values and NOE crosspeaks H3 or H4 to H11. Oleandomycin was found to be present predominantly in the C3-C5 folded-in conformations in DMSO-d6 solution, whereas in buffered D2O, acetone-d6 and CDCl3, there was a mixture of folded-in and folded-out conformational families. The predominant conformation of the 8-methylene-oleandomycin-9-oxime derivative in solution was a folded-out one although different amounts of folded-in conformation were also present depending on the solvent. Oleandrose and desosamine sugar moieties adopted the usual and expected chair conformation. The conformation around the glycosidic bonds, governing the relative orientation of sugars vs. the lactone ring, showed a certain flexibility within two conformationally close families. We believe that by combining the experimental NMR data and the molecular modelling techniques, as reported in this paper, we have made significant progress in understanding the conformational behaviour and properties of macrolides. Our belief is based on our own current studies on oleandomycins as well as on the previously reported results and best practices concerning other macrolides. A rational for macrolide conformational studies and advances in methodology has been suggested accordingly. PMID:15602597

  19. Methylene blue-assisted lymph node dissection technique is not associated with an increased detection of lymph node metastases in colorectal cancer.

    PubMed

    Märkl, Bruno; Schaller, Tina; Krammer, Ines; Cacchi, Claudio; Arnholdt, Hans M; Schenkirsch, Gerhard; Kretsinger, Hallie; Anthuber, Matthias; Spatz, Hanno

    2013-09-01

    Lymph node staging is of paramount importance for prognosis estimation and therapy stratification in colorectal cancer. A high number of harvested lymph nodes is associated with an improved outcome. Methylene blue-assisted lymph node dissection effectively improves the lymph node harvest and ensures sufficient staging. Now, the effect on node positivity rate and stage-related outcome was investigated. The study cohort with advanced lymph node dissection consisted of 669 colorectal cancer cases of all stages, which were collected between 2007 and 2012. A historical collection of 663 cases investigated with conventional techniques between 2002 and 2004 served as control. Lymph node harvest was dramatically improved in the study group with mean lymph node numbers of 34 ± 17 vs 13 ± 5 (P<0.001) and sufficient staging rates of 98% vs 62% (P<0.001). However, neither the rate of nodal positive cases (37% vs 37%; P = 0.98) nor the rate of N2 cases differed between the two groups (14% vs 13%; P = 0.80). Furthermore, no differences were found concerning the outcome in both groups. The advanced lymph node dissection technique guarantees adequate histopathological lymph node staging in virtually all cases of colorectal cancer and is therefore extremely helpful. The hypothesis that it also provides a higher sensitivity in detecting metastases, however, could be not proved.

  20. The Discriminative Properties of N-ETHYL-3,4-METHYLENE Dioxyamphetamine

    NASA Astrophysics Data System (ADS)

    Boja, John William

    The goal of this dissertation was to gain insight into the discriminative effects of N-ethyl-3,4-methylenedioxyamphetamine (MDE). In order to examine the possibility that MDE acts via both serotonergic and dopaminergic mechanisms, MDE was administered to three groups of rats trained to discriminate either (1) the serotonergic agent norfenfluramine from vehicle, (2) norfenfluramine from the dopaminergic agent amphetamine or (3) amphetamine from vehicle. The results of these discrimination studies are evidence that MDE expresses serotonergic and dopaminergic properties in a temporal pattern in which MDE initially activates the serotonergic system, followed by dopaminergic system activation. To examine additional discriminative effects of MDE, a separate group of rats was trained to discriminate 2.0 mg/kg MDE from vehicle. Various drugs were administrated to these animals to determine their similarity or dissimilarity to MDE. The results of this study are additional evidence as to a dual serotonergic/dopaminergic mediation for MDE. In addition, the related drug 3,4-methylenedioxymethamphetamine produced similar effects but this drug was more potent and possessed a longer duration of action than MDE. Subsequently, administration of the known serotonergic synthesis inhibitor para-chlorophenylalanine (PCPA) to the MDE trained rats reduced, but did not totally eliminate, MDE discrimination. This indicates that either reduced serotonin levels are still sufficient for MDE discrimination or that MDE discrimination is not solely mediated by serotonin. These experiments evidence a serotonergic/dopaminergic discriminative stimulus for MDE.

  1. 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

  2. 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.

  3. Military veterans with mental health problems: a protocol for a systematic review to identify whether they have an additional risk of contact with criminal justice systems compared with other veterans groups

    PubMed Central

    2012-01-01

    Background There is concern that some veterans of armed forces, in particular those with mental health, drug or alcohol problems, experience difficulty returning to a civilian way of life and may subsequently come into contact with criminal justice services and imprisonment. The aim of this review is to examine whether military veterans with mental health problems, including substance use, have an additional risk of contact with criminal justice systems when compared with veterans who do not have such problems. The review will also seek to identify veterans’ views and experiences on their contact with criminal justice services, what contributed to or influenced their contact and whether there are any differences, including international and temporal, in incidence, contact type, veteran type, their presenting health needs and reported experiences. Methods/design In this review we will adopt a methodological model similar to that previously used by other researchers when reviewing intervention studies. The model, which we will use as a framework for conducting a review of observational and qualitative studies, consists of two parallel synthesis stages within the review process; one for quantitative research and the other for qualitative research. The third stage involves a cross study synthesis, enabling a deeper understanding of the results of the quantitative synthesis. A range of electronic databases, including MEDLINE, PsychINFO, CINAHL, will be systematically searched, from 1939 to present day, using a broad range of search terms that cover four key concepts: mental health, military veterans, substance misuse, and criminal justice. Studies will be screened against topic specific inclusion/exclusion criteria and then against a smaller subset of design specific inclusion/exclusion criteria. Data will be extracted for those studies that meet the inclusion criteria, and all eligible studies will be critically appraised. Included studies, both quantitative and

  4. 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.

  5. Alteration of digestive tract microbiome in neonatal Holstein bull calves by bacitracin methylene disalicylate treatment and scours.

    PubMed

    Xie, G; Duff, G C; Hall, L W; Allen, J D; Burrows, C D; Bernal-Rigoli, J C; Dowd, S E; Guerriero, V; Yeoman, C J

    2013-10-01

    The effects of bacitracin methylene disalicylate (BMD) and scours on the fecal microbiome, animal performance, and health were studied in Holstein bull calves. Holstein bull calves (n = 150) were obtained from a single source at 12 to 24 h of age. Bull calves were randomly assigned to 1 of 2 treatments including CON (no BMD; n = 75 calves) and BMD (n = 75 calves). Starting 3 d after arrival, BMD was added into milk replacer (0.5 g/feeding; twice daily) and fed to the calves for 10 consecutive d. No differences (P > 0.10) were observed in ADG for d 0 to 28 and d 0 to 56, DMI for d 0 to 28, d 29 to 56, and d 0 to 56, or G:F for d 0 to 28, d 29 to 56, and d 0 to 56; ADG for d 29 to 56 tended to increase (P < 0.10) for BMD-treated calves compared with controls. Fecal samples were collected from 15 scouring calves and 10 cohorts (nonscouring calves received on the same day and administered the same treatment as the scouring calves). Animal morbidity and fecal score did not vary between the 2 treatments. Mortality was not influenced by the treatments in the BMD administration period or throughout the experiment. Fecal samples were subjected to pyrotagged 454 FLX pyrosequencing of 16S rRNA gene amplicon to examine compositional dynamics of fecal microbes. Escherichia, Enterococcus, and Shigella had greater (P < 0.05) populations in the BMD group whereas Dorea, Roseburia, Fecalibacterium, Papillibacter, Collinsella, Eubacterium, Peptostreptococcus, and Prevotella were decreased (P < 0.05) by BMD treatment. Genus populations were also compared between scouring and nonscouring calves. Streptococcus was the only genus that had notable increase (P < 0.05) in fecal samples from scouring calves whereas populations of Bacteroides, Roseburia, and Eubacterium were markedly (P < 0.05) greater in nonscouring calves. These results show that BMD has the ability to alter the composition of the fecal microbiome but failed to improve performance in Holstein bull calves. Discrepancy of

  6. Red blood cells donate electrons to methylene blue mediated chemical reduction of methemoglobin compartmentalized in liposomes in blood.

    PubMed

    Sakai, Hiromi; Li, Bing; Lim, Wei Lee; Iga, Yumika

    2014-07-16

    Electron-energy-rich coenzymes in cells, NADH and NADPH, are re-energized repeatedly through the Embden-Meyerhof and pentose-phosphate glycolytic pathways, respectively. This study demonstrates extraction of their electron energies in red blood cells (RBCs) for in vivo extracellular chemical reactions using an electron mediator shuttling across the biomembrane. Hemoglobin-vesicles (HbVs) are an artificial oxygen carrier encapsulating purified and concentrated Hb solution in liposomes. Because of the absence of a metHb-reducing enzymatic system in HbV, HbO2 gradually autoxidizes to form metHb. Wistar rats received HbV suspension (10 mL/kg body weight) intravenously. At the metHb level of around 50%, methylene blue [MB(+); 3,7-bis(dimethylamino)phenothiazinium chloride] was injected. The level of metHb quickly decreased to around 16% in 40 min, remaining for more than 5 h. In vitro mixing of HbV/MB(+) with RBCs recreated the in vivo metHb reduction, but not with plasma. NAD(P)H levels in RBCs decreased after metHb reduction. The addition of glucose facilitated metHb reduction. Liposome-encapsulated NAD(P)H, a model of RBC, reduced metHb in HbV in the presence of MB(+). These results indicate that (i) NAD(P)H in RBCs reacts with MB(+) to convert it to leukomethylene blue (MBH); (ii) MB(+) and MBH shuttle freely between RBC and HbV across the hydrophobic lipid membranes; and (iii) MBH is transferred into HbV and reduces metHb in HbV. Four other electron mediators with appropriate redox potentials appeared to be as effective as MB(+) was, indicating the possibility for further optimization of electron mediators. We established an indirect enzymatic metHb reducing system for HbV using unlimited endogenous electrons created in RBCs in combination with an effective electron mediator that prolongs the functional lifespan of HbV in blood circulation.

  7. 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.

  8. Adsorption of methylene blue on raw and MTZ/imogolite hybrid surfaces: effect of concentration and calorimetric investigation.

    PubMed

    Guerra, Denis L; Batista, Adriano C; Viana, Rúbia R; Airoldi, Claudio

    2010-11-15

    The synthetic imogolite sample was used for organofunctionalization process with 2-mercaptothiazoline (MTZ). The compound 2-mercaptothiazoline was anchored onto imogolite surface by heterogeneous route. Due to the increment of basic centers attached to the pendant chains the dye adsorption capability of the final chelating material, was found to be higher than is precursor. The ability of these materials to remove methylene blue from aqueous solution was followed by a series of adsorption isotherms at room temperature and pH 4.0. The maximum number of moles adsorbed was determined to be 40.32×10(-2) and 65.13×10(-2) mmol g(-1) for IMO and IMO(MTZ), respectively. The energetic effects caused by dye cations adsorption were determined through calorimetric titrations. Thermodynamics indicated the existence of favorable conditions for such methylene blue-nitrogen and sulfur interactions.

  9. 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%.

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

    PubMed

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

    2016-11-01

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

  11. Studies on the ion-association of methylene blue and salicylic acid in neat and mixed binary solvents

    NASA Astrophysics Data System (ADS)

    Basu, Soumen; Ghosh, Sujit Kumar; Kundu, Subrata; Nath, Sudip; Panigrahi, Sudipa; Praharaj, Snigdhamayee; Pal, Tarasankar

    2005-05-01

    Thiazine dye, methylene blue forms 1:1 ion-associate with salicylic acid in aqueous phase and the ion-associate can be extracted in a series of non-polar non-coordinating solvent systems. The influence of different parameters on the process of ion-association has been studied. The suitability of a number of phenolic precursors for the formation of ion-associate with methylene blue has been tested. Charge-transfer absorption band of the dye molecules in relation to ion-pair has been followed in a sequence of neat and mixed binary solvents and the dependence of the absorption maxima has been found to correlate well with the solvent polarity.

  12. Rapid inactivation of HIV-1 in single donor preparations of human fresh frozen plasma by methylene blue/light treatment.

    PubMed

    Lambrecht, B; Norley, S G; Kurth, R; Mohr, H

    1994-09-01

    Human fresh frozen plasma (FFP) was spiked with highly titered HIV-1 and illuminated with visible light in the presence of 1 microM of the photoactive dye methylene blue (MB). As shown by titration on MT-4 cells, the infectivity of the virus containing plasma was rapidly lost during illumination: after 5 min the infective titer was reduced by 4.3 and after 10 min by at least 6.32 log10, i.e. it was below the detection limit of the assay applied. Methylene blue without illumination and illumination alone had only a marginal effect on HIV-1 infectivity. Thus our data indicate that the MB/light treatment of FFP is an effective method to eliminate the risk of HIV-1 infection through use of the product. This is especially important for those cases in which the plasma is collected during the 'window period' between infection of the donor and the subsequent seroconversion.

  13. 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.

  14. 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.

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

    PubMed

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

    2016-11-01

    Methyl red, methylene blue and biochar were used to investigate simultaneous adsorption of dyes onto low-cost adsorbent at different concentrations combinations. Langmuir mixed model could describe the adsorption well at low concentrations. However, it could not describe the adsorption anymore when concentrations of methyl red and methylene blue were higher than 255 and 300 mg L(-1) respectively with 0.5 g L(-1) biochar loading. A new model on the interaction among adsorbed adsorbates at equilibrium was developed. It could describe the adsorption at high concentrations well. According to the experimental results, interaction among dyes molecules would replace the competition onto adsorbent to be the main factor influencing adsorption when amount of adsorbed adsorbates were higher than those required to form a monolayer on all the adsorbing sites of adsorbent. The model was further verified by adsorption with other solute such as glucose or NaCl in solution. PMID:27543677

  16. Group Work: How to Use Groups Effectively

    ERIC Educational Resources Information Center

    Burke, Alison

    2011-01-01

    Many students cringe and groan when told that they will need to work in a group. However, group work has been found to be good for students and good for teachers. Employers want college graduates to have developed teamwork skills. Additionally, students who participate in collaborative learning get better grades, are more satisfied with their…

  17. 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.

  18. Comparative study of polymer containing beta-cyclodextrin and -COOH for adsorption toward aniline, 1-naphthylamine and methylene blue.

    PubMed

    Zhao, Dong; Zhao, Liang; Zhu, Cheng-Shen; Shen, Xiangyu; Zhang, Xiaozhuan; Sha, Baofeng

    2009-11-15

    Three different polymers P1, P2 and P3 (P1 containing both beta-CD and -COOH, P2 containing beta-CD and P3 containing -COOH) were synthesized and applied to adsorption toward aniline, 1-naphthylamine and methylene blue. The concentrations (C) before and after adsorption were determined and the adsorption capacities (q) of P1, P2 and P3 were calculated. The maximum adsorption capacities (q(max)) toward aniline: q(max) (P1)=104 micromol g(-1), q(max) (P2)=14.9 micromol g(-1) and q(max) (P3)=53.1 micromol g(-1); toward 1-naphthylamine: q(max) (P1)=184 micromol g(-1), q(max) (P2)=53.8 micromol g(-1) and q(max) (P3)=125 micromol g(-1); toward methylene blue: q(max) (P1)=200 micromol g(-1), q(max) (P2)=12.7 micromol g(-1) and q(max) (P3)=215 micromol g(-1). P1 exhibited remarkable adsorption toward all the three adsorbates. P2 was almost equal to P1 in adsorption toward methylene blue, but was less efficient than P1 in adsorption toward aniline and 1-naphthylamine. P3 also exhibited considerable adsorption toward aniline and 1-naphthylamine, but was inefficient toward methylene blue. P1 was obtained from nontoxic materials and through environment friendly procedures, so it was potentially an efficient and green adsorbent for water purification.

  19. 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

  20. Bile ductular damage induced by methylene dianiline inhibits oval cell activation.

    PubMed Central

    Petersen, B. E.; Zajac, V. F.; Michalopoulos, G. K.

    1997-01-01

    Administration of 2-acetylaminofluorene (2-AAF) given before a two-thirds partial hepatectomy (PHx), results in suppression of hepatocyte proliferation and stimulation of oval cell proliferation. Our objective in this study was to examine the oval cell response and associated alpha-fetoprotein (AFP) gene expression by combining 2-AAF with selective hepatic damage caused by either carbon tetrachloride (CCl4) exposure or by PHx. We also examined oval cell response with the above two protocols (2-AAF/CCl4 and 2-AAF/PHx) as affected by previous bile ductular damage caused by 4,4'-methylene dianiline (4,4'-diaminodiphenylmethane, DAPM) exposure. DAPM is an aromatic diamine, known to cause bile ductular damage in both humans and animals. Using the protocols of 2-AAF/ CCl4 and 2-AAF/PHx, when DAPM was given 24 hours before the hepatic injury, no oval cell proliferation was seen (histological) and AFP expression was not detected by Northern blot analysis. These results provide direct evidence that oval cells are closely associated with the biliary epithelial cells and supports the theory that hepatic oval cells may originate from cells derived from either intraportal or periportal ductules. Images Figure 1 Figure 2 Figure 3 PMID:9327722

  1. Study on the interaction of methylene blue with cyclodextrin derivatives by absorption and fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Guomei; Shuang, Shaomin; Dong, Chuan; Pan, Jinghao

    2003-11-01

    The ability of β-cyclodextrin (β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD), and carboxymethyl-β-cyclodextrin (CM-β-CD) to break the aggregate of the methylene blue (MB) and to form 1:1 inclusion complexes has been studied by absorption and fluorescence spectroscopy. Experimental conditions including concentrations of various cyclodextrins (β-CD, HP-β-CD and CM-β-CD) and media acidity were investigated for the inclusion formation in detail. The formation constants are calculated by using steady-state fluorimetry, from which the inclusion capacity of different cyclodextrins (CDs) is compared. The results suggest that the charged β-cyclodextrin (CM-β-CD) is more suitable for inclusion of the cationic dye MB than the neutral β-cyclodextrins (β-CD, HP-β-CD) at pH>5. A mechanism is proposed which is consistent with the stronger binding of MB with CM-β-CD compared with the other CDs at pH>5.

  2. 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.

  3. 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

  4. A comparison of two sampling methods for the detection of airborne methylene bisphenyl diisocyanate.

    PubMed

    Schaeffer, Joshua W; Sargent, Layne Marie; Sandfort, Delvin R; Brazile, William J

    2013-01-01

    The purpose of this study was to determine if there was a significant difference between two readily available sampling methodologies for airborne methylene bisphenyl diisocyanate (MDI), which is an essential precursor in the spray-on truck bed lining industry. Seventy-two personal airborne samples of MDI were collected and analyzed from nine spray-on truck bed liner businesses in northern Colorado. Wide ranges of exposure concentrations were encountered during the spray-on application, including concentrations that exceeded the OSHA permissible exposure limit. The highest airborne MDI concentration measured was 690 ppb. A statistically significant difference between field-desorbed and laboratory-desorbed methods was determined. The field-desorbed sampling methodology yielded consistently higher MDI concentrations than the laboratory-desorbed sampling methodology, which suggests that immediate desorption minimizes isocyanate loss and potential underestimations. Results from the analysis of variance also indicated that different facility factors and environmental conditions within each company, such as the use of ventilation or humidity level, affected the MDI concentrations, indicating the potential for better mitigation of exposures using the hierarchy of controls.

  5. 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.

  6. Molecular determinants of humoral immune specificity for the occupational allergen, methylene diphenyl diisocyanate.

    PubMed

    Wisnewski, Adam V; Liu, Jian

    2013-06-01

    Methylene diphenyl diisocyanate (MDI), a low molecular weight chemical important for producing polyurethane foam, coatings, and elastomers is a major cause of occupational asthma, however, mechanisms of disease pathogenesis remain poorly understood. This study characterizes the rearranged germline and hypervariable region cDNA of new anti-MDI secreting hybridomas derived from mice immunized with MDI-conjugated to autologous serum proteins. Six IgG1 secreting clones were identified in initial screening ELISAs, based on differential binding to MDI conjugated human albumin vs. mock exposed albumin. The mAbs secreted by the hybridomas also recognized MDI conjugated to other model proteins (e.g. ovalbumin, transferrin), but did not bind unconjugated proteins, or protein conjugates prepared with other isocyanates (e.g. TDI, HDI). The mAbs displayed MDI-dose dependent binding in ELISA and Western blot, and exhibited varying degrees of cross-competition, suggesting differences in epitope specificity. The cDNA encoding the monoclonal antibodies reveal clonal differences in the CDR3 regions, germline gene usage, and patterns of somatic hypermutation related to epitope specificity. Together, the data provide new insight into the molecular determinants of humoral MDI specificity, and characterize anti-MDI IgG1 mAbs that may be developed into useful diagnostic reagents.

  7. 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

  8. The binding properties of photosensitizer methylene blue to herring sperm DNA: a spectroscopic study.

    PubMed

    Zhang, Lei Z; Tang, Guo-Qing

    2004-05-27

    Methylene blue (MB) is a phenothiazinium photosensitizer with promising applications in the photodynamic therapy (PDT) for anticancer treatment. The binding properties of MB to herring sperm DNA have been investigated by the measurements of absorption spectra, quenching experiments and the elucidation of the photobleaching processes. Remarkable hypochromic and bathochromic effects of MB in the presence of increasing amounts of DNA have been observed in the absorption spectra. The quenching of MB by the DNA bases obeys the Stern-Volmer equation and ferrocyanide quenching of MB in the absence and presence of DNA is also measured as extended experiments. Results from the above spectral measurements are all consistent with the intercalative binding mode of MB to DNA with the Kb value of 1.89 x 10(4) M(-1). The photobleaching processes of MB and its DNA complex have also been studies, which indicate that the photobleaching of MB and its DNA complex proceeds with different mechanisms and the reactive oxygen species are responsible for the self-sensitized photooxidation of MB. PMID:15157907

  9. Activated carbon coated palygorskite as adsorbent by activation and its adsorption for methylene blue.

    PubMed

    Zhang, Xianlong; Cheng, Liping; Wu, Xueping; Tang, Yingzhao; Wu, Yucheng

    2015-07-01

    An activation process for developing the surface and porous structure of palygorskite/carbon (PG/C) nanocomposite using ZnCl2 as activating agent was investigated. The obtained activated PG/C was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (SEM), and Brunauer-Emmett-Teller analysis (BET) techniques. The effects of activation conditions were examined, including activation temperature and impregnation ratio. With increased temperature and impregnation ratio, the collapse of the palygorskite crystal structure was found to accelerate and the carbon coated on the surface underwent further carbonization. XRD and SEM data confirmed that the palygorskite structure was destroyed and the carbon structure was developed during activation. The presence of the characteristic absorption peaks of CC and C-H vibrations in the FTIR spectra suggested the occurrence of aromatization. The BET surface area improved by more than 11-fold (1201 m2/g for activated PG/C vs. 106 m2/g for PG/C) after activation, and the material appeared to be mainly microporous. The maximum adsorption capacity of methylene blue onto the activated PG/C reached 351 mg/g. The activated PG/C demonstrated better compressive strength than activated carbon without palygorskite clay. PMID:26141882

  10. The use of methylene blue in abdominal aortic surgery: a case report.

    PubMed

    Piraccini, E; Agnoletti, V; Corso, R; Maitan, S; Gambale, G

    2010-01-01

    The open abdominal aortic surgery includes a well-known phase in which arterial blood flow is stopped by occluding clamps, resulting in peculiar physiologic changes usually superimposed on advanced pathologic conditions. An anesthetic plan should aim at providing hemodynamic stability and preserving organ function. Clamp removal leads to an acute fall in blood pressure following a decrease in systemic vascular resistance, caused by reactive hyperemia due to opening of the previously minimally perfused vascular beds. Several different mediators, including the nitrous oxide (NO) pathway, have been thought to be responsible for this hemodynamic effect. The massive production of NO by the inducible isoform of NO synthase could be partially responsible for the profound vasodilatation and myocardial dysfunction. The dye methylene blue (MB) has been used as to prevent vasodilatation in other clinical situations like sepsis, cardiopulmonary bypass and liver transplantation. We describe its use in a patient with poor hemodynamic status, who was submitted to aortic aneurism repair with infrarenal cross clamp. The intervention was also associated with a severe bleeding. In this case MB allowed us to control hypotension with relatively low doses of vasopressors. PMID:23440623

  11. 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

  12. Comparative evaluation of methylene blue and demeclocycline for enhancing optical contrast of gliomas in optical images.

    PubMed

    Wirth, Dennis; Snuderl, Matija; Curry, William; Yaroslavsky, Anna

    2014-09-01

    Contrast agents have shown to be useful in the detection of cancers. The goal of this study was to compare enhancement of brain cancer contrast using reflectance and fluorescence confocal imaging of two fluorophores, methylene blue (MB) and demeclocycline (DMN). MB absorbs light in the red spectral range and fluoresces in the near-infrared. It is safe for in vivo staining of human skin and breast tissue. However, its safety for staining human brain is questionable. Thus, DMN, which absorbs light in the violet spectral range and fluoresces between 470 and 570 nm, could provide a safer alternative to MB. Fresh human gliomas, obtained from surgeries, were cut in half and stained with aqueous solutions of MB and DMN, respectively. Stained tissues were imaged using multimodal confocal microscopy. Resulting reflectance and fluorescence optical images were compared with hematoxylin and eosin histopathology, processed from each imaged tissue. Results indicate that images of tissues stained with either stain exhibit comparable contrast and resolution of morphological detail. Further studies are required to establish the safety and efficacy of these contrast agents for use in human brain.

  13. Graphene oxide mediated delivery of methylene blue for combined photodynamic and photothermal therapy.

    PubMed

    Sahu, Abhishek; Choi, Won Il; Lee, Jong Hyun; Tae, Giyoong

    2013-08-01

    Nano graphene oxide sheet (nanoGO) was non-covalently functionalized with Pluronic block copolymer and complexed with methylene blue, a hydrophilic and positively charged photosensitizer, via electrostatic interaction for combined photodynamic-photothermal therapy of cancer. Pluronic coating of nanoGO ensured its stability in biological fluids. NanoGO plays dual role of a photothermal material as well as a delivery agent for photosensitizer. The release of the photosensitizer from nanoGO surface was pH-dependent and an acidic condition increased the release rate considerably. This nanocomplex showed enhanced uptake by cancer cells than normal cells and in the absence of light it showed no major toxicity towards the cells. In contrast, when irradiated with selective NIR laser lights, it induced significant cell death. Intravenous injection of the complex into tumor bearing mice showed high tumor accumulation, and when the tumors were exposed to NIR lights, it caused total ablation of tumor tissue through the combined action of photodynamic and photothermal effects. This work shows the potential of nanoGO for synergistic combination phototherapy of tumor in vivo.

  14. Methylene blue-mediated photodynamic therapy enhances apoptosis in lung cancer cells.

    PubMed

    Lim, Eun Jin; Oak, Chul-Ho; Heo, Jeonghoon; Kim, Young-Ho

    2013-08-01

    Combined treatment with a photosensitizer and iodide laser [photodynamic therapy (PDT)] has improved the outcome of various cancers. In this study, we investigated the effects of using the photosensitizer methylene blue (MB) in PDT in human lung adenocarcinoma cells. We found that MB enhances PDT-induced apoptosis in association with downregulation of anti-apoptotic proteins, reduced mitochondrial membrane potential (MMP), increased phosphorylation of the mitogen-activated protein kinase (MAPK) and the generation of reactive oxygen species (ROS). In MB-PDT-treated A549 cells, we observed PARP cleavage, procaspase-3 activation, downregulation of the anti-apoptotic proteins Bcl-2 and Mcl-1, and the reduction of mitochondrial membrane potential (MMP). Western blot data showed that phosphorylation of p38 was increased in MB-PDT-treated A549 cells, indicating that several signaling molecules participate in the apoptotic cascade. Our data also showed that apoptotic cell death in MB-PDT-treated cells occurred through a series of steps beginning with the photochemical generation of ROS. Demonstrating the role of ROS, pretreatment of A549 cells with the antioxidant N-acetylcysteine (NAC) followed by MB-PDT resulted in increased cell viability and reduced proteolytic cleavage of PARP.

  15. 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.

  16. 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.

  17. Chemoconvection patterns in the methylene-blue-glucose system: Weakly nonlinear analysis

    NASA Astrophysics Data System (ADS)

    Pons, A. J.; Sagués, F.; Bees, M. A.

    2004-12-01

    The oxidation of solutions of glucose with methylene-blue as a catalyst in basic media can induce hydrodynamic overturning instabilities, termed chemoconvection in recognition of their similarity to convective instabilities. The phenomenon is due to gluconic acid, the marginally dense product of the reaction, which gradually builds an unstable density profile. Experiments indicate that dominant pattern wavenumbers initially increase before gradually decreasing or can even oscillate for long times. Here, we perform a weakly nonlinear analysis for an established model of the system with simple kinetics, and show that the resulting amplitude equation is analogous to that obtained in convection with insulating walls. We show that the amplitude description predicts that dominant pattern wavenumbers should decrease in the long term, but does not reproduce the aforementioned increasing wavenumber behavior in the initial stages of pattern development. We hypothesize that this is due to horizontally homogeneous steady states not being attained before pattern onset. We show that the behavior can be explained using a combination of pseudo-steady-state linear and steady-state weakly nonlinear theories. The results obtained are in qualitative agreement with the analysis of experiments.

  18. Adsorption of methylene blue and methyl red dyes from aqueous solutions onto modified zeolites.

    PubMed

    Ioannou, Z; Karasavvidis, Ch; Dimirkou, A; Antoniadis, V

    2013-01-01

    Zeolite, hematite, modified zeolite and commercial activated charcoal were examined for their ability to remove methylene blue (MB) and methyl red (MR) from their aqueous solutions. Modified zeolite and hematite were produced according to the Schwertmann and Cornell method while zeolite and commercial activated charcoal were obtained from S&B and Fluka AG companies, respectively. Adsorption experiments were conducted at three different adsorbent-to-solution ratios, namely 8, 16 and 24 g/L under environmental conditions and continuous stirring. Equilibrium isotherms of MB and MR were studied at different initial concentrations (from 5 × 10(-4) to 5 × 10(-3) g/L). MB adsorption kinetics were also studied. The maximum adsorption of MB and MR from their aqueous solutions was achieved at 24 g/L (adsorbent-to-dye solution ratio) after 1 h and was equal to 100% (MB) on modified zeolite and 99% (MR) on commercial activated charcoal, respectively. All the other materials achieved intermediate values of dye adsorption. From the applied kinetic models, the pseudo-second-order equation best described the adsorption of MB and MR. Consequently, modified zeolite showed the highest adsorption capacity for MB, while commercial activated charcoal showed the highest adsorption capacity of MR. The studied adsorbents can be used as filters to remove dyes from wastewaters.

  19. Kinetics of competitive adsorption of β-casein and methylene blue on hydrophilic glass.

    PubMed

    Qi, Zhi-mei; Lu, Dan-feng; Deng, Lin; Matsuda, Naoki

    2012-03-01

    The competitive adsorption of methylene blue (MB) and β-casein on hydrophilic glass from an aqueous mixed solution was directly detected at the solution pH smaller than the protein isoelectric point (pI) by means of the waveguide-based broadband time-resolved evanescent wave absorption spectroscopy. The competitive adsorption causes the MB coverage to exponentially decrease with time from its peak value and prevents MB aggregation at the interface. The kinetic equation for the competitive adsorption of binary adsorbates was theoretically deduced based on the Langmuir model, and was used for creating the best fit to the experimental data. In the case of a fixed concentration of MB in the mixed solution, the best-fit parameter τ(-1) increases with the protein concentration at a specific pH and decreases with the solution pH at a given concentration of protein. The findings suggest that the β-casein concentration in sub-μM level can be rapidly determined by the time-resolved waveguide absorptiometry based on the competitive adsorption of MB and protein.

  20. Adsorption and Photocatalytic Degradation of Methylene Blue Using Potassium Polytitanate and Solar Simulator.

    PubMed

    Shahid, Mohammad; El Saliby, Ibrahim; McDonagh, Andrew; Chekli, Laura; Tijing, Leonard D; Kim, Jong-Ho; Shon, Ho Kyong

    2016-05-01

    Solar photocatalytic degradation of organic water pollutants can be used to degrade toxic organic pollutants in water. In this study, potassium titanate nanofibres were synthesized by an aqueous peroxide route at high pH and examined as photocatalysts for photodegradation of methylene blue (MB) using a solar simulator. Initially, MB was adsorbed on the surface of potassium polytitanates to achieve adsorption equilibrium before the photocatalysts were illuminated using solar simulator. The results showed that potassium polytitanate nanofibres were effective adsorbents of MB and also facilitated its photocatalytic degradation. Sulphate ion evolution during photocatalysis confirmed that some mineralisation occurred and hence photo-oxidative degradation of MB took place. The optimum operational conditions for the photocatalytic degradation of MB were found at 0.05 g/L of photocatalyst load, 10 mg/L MB and pH 7. The stability and regeneration of the photocatalyst specimen was also studied for 3 degradation cycles using adsorption/photocatalysis model. Morphological structure analysis of potassium titanate showed nanocrystallines structure of longitudinally-oriented isolated fibre with a length up to several micrometres with diameters ranging from 10 to 20 nanometres.