Analysis Of Reaction Products Research Articles

Pechini Synthesis of Na3V2(PO4)2F3/C Doped with Aluminum As Cathode for Lithium Ion Batteries

The demand of rechargeable batteries had increased significantly every year during the last decade, driven for the needs associated with technological development (portability, high performance of electronic devices and vehicles). Lithium ion battery is a device of mayor consumption, and it is designed for energy storage and conversion based on intercalation electrodes. Nowadays the efforts are directed to the improvement and replacement of current battery components: anode, cathode (LiCoO2) electrolyte, with materials that have higher efficiency in terms of energy, power, cost, reliability, life time and safety. In recent years there has been significant interest in polyanion-based active materials as safe alternatives for the traditional oxide cathodes. For example, phosphate phases such as LiFePO4 [1], Li3V2(PO4)3, [2], Li2.5V2(PO4)3, [3], LiVOPO4, [4,5] and LiVP2O7[6] have all been proposed. Therefore, the search of new cathode materials is an important task for researchers in materials science. The possibility of using sodium directly in lithium ion cells allows the study of new compositions and structures. In this research work a series of four compounds with formula Na3V2-xAlx(PO4)2F3 (x= 0, 0.02, 0.05, 0.1) were prepared, characterized and applied as cathode materials in lithium ion batteries. These materials were synthesized by sol-gel Pechini method. Aqueous solutions containing appropriate amounts of NH4VO3, NH4H2PO4 and NaF were poured into a mixture of citric acid and ethylene glycol solution. Mixture was then heat treated under reflux at 80°C until gel formation. Fresh samples were heated at 300°C under air to eliminate volatile matter. Resulting powders were grinded and formed into pellets for reaction between 300 to 650°C under nitrogen atmosphere. Thermal stability of materials was evaluated by simultaneous termogravimetric and differential analysis (TGA-DTA). Morphological and microstructural characterization were carried out with field emission scanning electron microscopy (FESEM), textural analysis by N2 physisorption with BET method; chemical composition and crystallographic parameters were determined with Induced coupled plasma – optic emission spectroscopy (ICP-OES), energy dispersive X-ray spectroscopy (EDXS) and X-ray powder diffraction (XRD); the application of materials as cathodes in lithium ion batteries was evaluated through electrochemical charge discharge experiments. Electrodes were prepared using a mixture of each synthesized materials, conductive carbon and PVDF binder. CR2032 coin cells were assembled inside a glove box under Ar atmosphere, using LiPF6electrolyte and Li° as anode. Experiments were performed using a MacPile II by Biologic. Thermal analysis of sol-gel reaction products exhibited an exothermic even between 550 and 750°C attributed to the crystallization of the fluorophosphates. Results from XRD analysis showed that Al doped Na3V2(PO4)2F3 crystalline phase was formed at 650°C for 8h. According to cell parameters Na3V2(PO4)2F3 can incorporate aluminum content up to x=0.1, without the presence of secondary phases or structural transitions. Granular morphology and small particles size of about 40 to 100 nm were observed, this can be attributed to the effect of residual carbon within samples (8% by weight) since this inhibits particle grown and also allows contact among particles, improving electrical conductivity. Materials present average porous size of about 20nm, with surface area of 30m2/g. The sample with x=0.05 of Aluminum content, presents the best textural properties. This material also presents high specific charge/discharge capacity (123/101 mAh/g at a 4.4 V vs Li cell) and good capacity retention (82%), in comparison to the material without doping (128/63 mAh/g and 49% of capacity retention). Aluminum doping of Na3V2(PO4)2F3phase permitted the stabilization of the structure related to cycling processes. These results are promising for future application of the material in lithium and sodium ion batteries. Keywords: Pechini, cathodes, phosphates, lithium ion batteries References [1] A.K. Padhi, K.S. Nanjundaswamy, C. Masquelier, J.B. Goodenough, J. Electrochem. Soc. 144 (1997) 2581. [2] M.Y. Saidi, J. Barker, H. Huang, J.L. Swoyer, G. Adamson, Electrochem. Solid-State Lett. 5 (2002) A149. [3] C. Yin, H. Grondey, P. Strobel, L.F. Nazar, Chem. Mater. 16 (2004) 1456. [4] B.M. Azmi, T. Ishihara, H. Nishiguchi, Yusaku Takita, J. Power Sources 146 (1–2) (2005). [5] J. Gaubicher, T. Le Mercier, Y. Chabre, J. Angenault, M. Quarton, J. Electrochem. Soc. 146 (1999) 4375. [6] J. Barker, R.K.B. Gover, P. Burns, A. Bryan, Electrochem. Solid-State Lett. 8 (9) (2005) 446.

Selective hydrogenation of fatty acids to alcohols over highly dispersed ReOx/TiO2 catalyst

Production of fatty alcohols through selective hydrogenation of fatty acids was studied over a 4% ReOx/TiO2 catalyst. Stearic acid was hydrogenated to octadecanol at temperatures and pressures between 180–200°C and 2–4MPa, with selectivity reaching 93%. A high yield of octadecanol was attributed to a strong adsorption of the acid compared to alcohol on the catalyst, which inhibits further alcohol transformation to alkanes. Low amounts (<7%) of alkanes (mainly octadecane) were formed during the conversion of stearic acid. However, it was found that the catalyst could be tuned for the production of alkanes. The reaction intermediates were octadecanal and stearyl stearate. Based on the reaction products analysis and catalyst characterization, a reaction mechanism and possible pathways were proposed.

Identification and characterization of 3,6-anhydro-L-galactonate cycloisomerase belonging to theenolase superfamily

Recently, we have shown that Postechiella marina M091 degrades 3,6-anhydro-L-galactose (L-AnG) to pyruvate and D-glyceraldehyde-3-phosphate via six enzyme-catalyzed reactions and that the L-AnG dehydrogenase, an enzyme catalyzing the first step of L-AnG degradation, converts L-AnG to 3,6-anhydro-L-galactonate (L-AnGA). In this study, we report the identification and characterization of L-AnGA cycloisomerase (L-AnGACI), a novel enzyme that catalyzes the second step of L-AnG metabolism in agar-degrading microorganisms. To characterize this enzyme, the L-AnGACI gene (M091_0722) from P. marina (Pm_LAnGACI) was cloned and expressed in E. coli. The recombinant Pm_L-AnGACI catalyzed conversion of LAnGA to 2-keto-3-deoxy-L-galactonate (L-KDGal), which was confirmed by the L-KDGal aldolase reaction and the LC-MS analysis of the aldolase reaction products. The enzyme showed activity only towards L-AnGA (100%) and galactarate (1.8%) among the 12 sugar acids and carboxylates tested, and the enzyme activity was maximal at 30°C and pH 8.0. Enzyme activity was enhanced by addition of divalent ions such as Co2+ and Mg2+, as is observed from enzymes of the enolase superfamily. L-AnGACI conserves several residues commonly found in the enolase superfamily, including three metal-ion binding ligands (Asp198, Glu224, Glu250) and five active-site residues (Lys167, Lys169, Asp273, His300, Glu320). Phylogenetic analysis of amino acid sequences indicates that Pm_L-AnGACI belongs to a novel family within the mandelate racemase subgroup of the enolase superfamily. A reaction mechanism for cycloisomerization of L-AnGA to L-KDGal is proposed, which implies that the absolute configuration does not change during the reaction. To our knowledge, this is the first report on the characterization of L-AnGACI.

Wet removal of sulfur dioxide and nitrogen oxides from simulated flue gas by ca(ClO)2 solution

To study the simultaneous removal of Sulfur Dioxide (SO2) and Nitrogen Oxides (NOx) from simulated flue gas by wet method, a bubbling device containing calcium hypochlorite (Ca(ClO)2) solution was used in the experiments. In the first place, thermodynamic analysis was conducted to determine the depth of reaction process, and the reaction mechanism of desulfurization and denitration was proposed. After that, experimental results exhibited that SO2 could be removed by Ca(ClO)2 solution completely while the removal efficiency of NOx was 41.2%. Moreover, on the basis of high SO2 removal efficiency, the effects of various factors on the removal efficiency of NOx, such as: the height of liquid layer, Ca(ClO)2 concentration, reaction temperature, initial pH value, O2 percent, SO2 concentration, and additives were investigated, respectively. Finally, simultaneous removal of SO2 and NOx under the optimized conditions were investigated, SO2 removal efficiency of 100% and NOx removal efficiency of 85.9% were achieved. The analysis of reaction products indicated that the main anions in the liquid phase were and . © 2015 American Institute of Chemical Engineers Environ Prog, 34: 1586–1595, 2015

Mechanistic Study of Palladium Based Electrocatalysts for Direct Borohydride Oxidation

The direct borohydride fuel cell (DBFC) is one of several promising direct liquid fuel cells due to easy fuel handling and high energy storage density [1]. DBFCs are still in an early stage of development and further improvements of anode catalyst materials and MEA design are necessary for widespread application. Herein we present an extensive study of Palladium based catalysts for the anode reaction of DBFCs (see reaction 1) including several electrochemical experiments supported by 11B-NMR and FTIR measurements. BH4 - + 8OH- → BO2 - + 6H2O + 8e- (1) (E0 = -1.24 V vs. SHE) Palladium based electrocatalysts nanodispersed on high surface area carbon are prepared by reduction of precursor salts in an aqueous dispersion of the support material. The catalyst is characterized by transition electron microscopy (TEM). Rotating disk electrode (RDE) and rotating ring disk electrode (RRDE) experiments with subsequent analysis of reaction products by 11B-NMR are conducted. Fig. 1 shows a typical result of Pd/C on a RDE with a borohydride concentration of 5 mM. Additionally mechanistic aspects on Palladium are investigated employing in-situ FTIR spectroscopy [2]. By combining all results obtained from the experiments mentioned above a substantial proposition of ongoing mechanisms of BH4 --electrooxidation on Palladium is presented. [1] J. Ma, N. a. Choudhury, Y. Sahai, Renew. Sustain. Energy Rev. 14 (2010) 183. [2] B.M. Concha, M. Chatenet, C. Coutanceau, F. Hahn, Electrochem. Commun. 11 (2009) 223. Caption Figure 1: RDE experiments of Pd/C catalyst at rotation rates of 0-2000 rpm (anodic sweeps) in 1M NaOH with 5 mM NaBH4, insert: according Levich-plot at 0.830 V. Figure 1

Increasing Octane Value in Catalytic Cracking of n-Hexadecane with Addition of *BEA Type Zeolite

In this study, multifunctional catalysts were developed by adding *BEA or MFI zeolite with high Si/Al ratio to a residual fluidized catalytic cracking (RFCC) catalyst and tested in the catalytic cracking of n-hexadecane, which is a heavy crude oil model compound, for the purpose of increasing the octane value of produced gasoline under the strong hydrogen transfer activity of the RFCC catalyst. Reaction products analysis revealed that the addition of *BEA zeolite to the RFCC catalyst increased the yields of olefins and multi-branched paraffins, which resulted in improvement of the octane value without sacrificing gasoline yield. On the contrary, the addition of MFI zeolite decreased the gasoline yield because it cracks the gasoline range olefins into LPG range olefins. In general, it is difficult to increase the yield of multi-branched molecules because the multi-branched molecule is more easily cracked than linear molecules. Our results suggest the possibility for the selective acceleration of isomerization reaction by the addition of less acidic *BEA zeolite to the RFCC catalyst.

Spectroscopic and Computational Study of Cr Oxide Structures and Their Anchoring Sites on ZSM-5 Zeolites

Cr/ZSM-5 catalysts with 0.5–2.6 wt % Cr loadings and zeolites with 15–140 Si/Al ratios were characterized with in situ UV–vis, IR, and Raman spectroscopies, including operando Raman measurements under reaction conditions in methane conversion at 773–1123 K with a simultaneous online analysis of reaction products. DFT calculations with cluster and periodic models were performed with DMol3, Gaussian 09, and VASP software packages. Isolated Cr(VI) dioxo and Cr(III) mono-oxo structures on framework Al anchoring sites were identified as the dominant species under most conditions. In the absence of gas-phase O2 (under Ar flow) at 773 K, the Cr(VI) dioxo species on framework Al anchoring sites autoreduce, and the Cr(III) mono-oxo species remain the only observable surface Cr oxide structures. For ZSM-5 zeolites with a relatively low concentration of framework Al atoms (Si/Al ≥ 25), exposure to gas-phase O2 at 773 K forces surface Cr oxide species to migrate from framework Al anchoring sites to Si sites on the ex...

Degradation of ciprofloxacin in aqueous bismuth oxybromide (BiOBr) suspensions under visible light irradiation: A direct hole oxidation pathway

Ciprofloxacin (CIP) in natural waters has caused serious environmental problems because of its potent biological activity. In this study, the visible light-induced degradation of CIP was examined by using bismuth oxybromide (BiOBr) as photocatalyst. The flake-shape BiOBr was synthesized by hydrothermal method and characterized by X-ray powder diffraction, scanning electron microscopy and UV–vis diffuse reflectance spectroscopy. The degradation process was monitored by high performance liquid chromatography. The photodegraded intermediates were identified by high performance liquid chromatography–mass spectrometry and the degradation pathway was proposed on the basis of product analysis. It was found that, during the visible light induced degradation of CIP on BiOBr, the piperazine moiety of CIP was the predominant reaction sites, while the quinolone and cyclopropane rings remained essentially intact. The pH-dependence of reaction rates, product analysis and theoretical calculation pointed to a surface reaction mechanism that the CIP oxidation is dominant by the direct hole oxidation process, whereas OH, which is the common active species in the advance oxidation processes, is not effective in the visible light induced photocatalytic process on BiOBr. This study demonstrated that CIP is a good model substrate to uncover the photodegradation mechanism for photocatalyst whose valence band has moderate oxidation ability.

Fast testing for explosive properties of mg-scale samples by thermal activation and classification by physical and chemical properties

To test explosive properties of substances, the strong exothermal reaction of an explosive after ignition can be used. Monitoring the emitted visible or infrared radiation by photodiodes and the change in pressure by a transducer in a closed system offers a low cost and mobile explosive identification device. The explosives investigated were hexamethylene triperoxide diamine, pentaerythritol tetranitrate, ammonium gelignite, ammonium nitrate fuel oil, cyclotrimethylene trinitramine, cyclotetramethylene tetranitramine, black powder, nitrocellulose, trinitrophenylmethylnitramine, gun propellant, triacetone triperoxide and trinitrotoluene. It has been shown, that the fast thermal activation of single-digit mg samples yields reproducible results for primary explosives, propellants, and trinitrotoluene. An analysis of the volatile reaction products with commercial semi-conductor gas sensors enables a differentiation between nitrate- and peroxide-based explosives and non-explosives.

RfiA, a novel PAP2 domain-containing polytopic membrane protein that confers resistance to the FtsZ inhibitor PC190723.

As an essential protein for bacterial cell division, the tubulin-like FtsZ protein has been selected as a target for development of next generation antimicrobials. PC190723 is a fluoride-containing benzamide compound developed as a FtsZ inhibitor that selectively inhibits growth of multidrug resistant Gram-positive bacteria. Our aim was to investigate the mechanism of resistance to PC109723 conferred by over-expression of a gene, rfiA, in an environmental bacterium Arthrobacter A3. The investigations included analysis of the effect of PC109723 on wild-type Arthrobacter A3 and a recombinant strain over-expressing rfiA, in vivo localization of RfiA, in vitro measurements of fluorine release from PC109723 by membrane extracts from the over-expression strain combined with mass spectrophotometric analysis of reaction products, and modelling of RfiA structure. We describe a novel protein, RfiA, from Arthrobacter A3 that confers PC190723 resistance. RfiA is a PAP2 domain-containing polytopic transmembrane protein that can modify the fluoridated benzamide ring that is critical for high affinity binding of PC190723 with FtsZ. RfiA-mediated modification of PC190723 is the first reported instance of resistance to this antibiotic involving a change to its structure. We predict that adoption of PC190723 or related benzamides as antimicrobials in clinical practice will lead to the acquisition by resistant pathogens of a gene encoding this subfamily of proteins.

Biochemical Characterization and Overexpression of an Endo-rhamnogalacturonan Lyase from Penicillium chrysogenum.

Rhamnogalacturonan lyase (PcRGL4A) was purified from the culture supernatant of Penicillium chrysogenum 31B. PcRGL4A optimal activity occurred between pH 7-8 and at 40°C. Conserved Domain Search analysis identified PcRGL4A as a member of Polysaccharide Lyase family 4. PcRGL4A contains two conserved catalytic and four conserved substrate-binding residues as determined by X-ray crystallography of the Aspergillus aculeatus RG lyase. Recombinant PcRGL4A (rPcRGL4A) expressed in Escherichia coli demonstrated specific activity against rhamnogalacturonan (RG) but not homogalacturonan. Analysis of the RG reaction products by high-performance anion-exchange chromatography revealed that rPcRGL4A cleaved the substrate in an endo-manner and that the major final product was an RG tetrasaccharide with 4-deoxy-4,5-unsaturated galacturonic acid at the nonreducing end. Based on these results, PcRGL4A was classified as an endo-acting RG lyase (EC 4.2.2.23). Divalent cations were not essential for the enzymatic activity of rPcRGL4A, but addition of calcium ions to the reaction mixture increased enzymatic activity. rPcRGL4A demonstrated a preference for RG lacking galactose decoration.

A novel pyrroloquinoline quinone-dependent 2-keto-D-glucose dehydrogenase from Pseudomonas aureofaciens.

A gene encoding an enzyme similar to a pyrroloquinoline quinone (PQQ)-dependent sugar dehydrogenase from filamentous fungi, which belongs to new auxiliary activities (AA) family 12 in the CAZy database, was cloned from Pseudomonas aureofaciens. The deduced amino acid sequence of the cloned enzyme showed only low homology to previously characterized PQQ-dependent enzymes, and multiple-sequence alignment analysis showed that the enzyme lacks one of the three conserved arginine residues that function as PQQ-binding residues in known PQQ-dependent enzymes. The recombinant enzyme was heterologously expressed in an Escherichia coli expression system for further characterization. The UV-visible (UV-Vis) absorption spectrum of the oxidized form of the holoenzyme, prepared by incubating the apoenzyme with PQQ and CaCl2, revealed a broad peak at approximately 350 nm, indicating that the enzyme binds PQQ. With the addition of 2-keto-d-glucose (2KG) to the holoenzyme solution, a sharp peak appeared at 331 nm, attributed to the reduction of PQQ bound to the enzyme, whereas no effect was observed upon 2KG addition to authentic PQQ. Enzymatic assay showed that the recombinant enzyme specifically reacted with 2KG in the presence of an appropriate electron acceptor, such as 2,6-dichlorophenol indophenol, when PQQ and CaCl2 were added. (1)H nuclear magnetic resonance ((1)H-NMR) analysis of reaction products revealed 2-keto-d-gluconic acid (2KGA) as the main product, clearly indicating that the recombinant enzyme oxidizes the C-1 position of 2KG. Therefore, the enzyme was identified as a PQQ-dependent 2KG dehydrogenase (Pa2KGDH). Considering the high substrate specificity, the physiological function of Pa2KGDH may be for production of 2KGA.

Sex Identification of Jackass Penguins (Spheniscus demersus) using the CHD Gene

In many avian species, it is difficult to distinguish the sexes based on their external features. Sex determination is an important area of study in developmental and evolutionary biology, as well as in ecology. In penguins, physical sexual characteristics between males and females are hard to differentiate particularly the Jackass penguins (Spheniscus demersus) which show little sexual dimorphism. Although it is always thought that males are usually larger than females, sexing by direct observation may be difficult especially in young birds. In this research, we evaluated a sex determination technique in Jackass Penguins using genomic deoxyribonucleic acid (DNA) amplification using primers. Genomic DNA was extracted from feathers of Jackass penguins, Chickens (Gallus gallus domesticus) and Ducks (Anas Platyrhynchos var. domestica) using E prep (Viagenkorea.CO, Korea) reagent. A primer set is designed for sex determination. The primers amplifythe homologous region of the CHD-W gene (chromo-helicase-DNA-binding gene) unique to females, and the CHD-Z gene, occurring in both sexes and characterized by two bands in females and only one band in males. The results showed that analyses of the polymerase chain reaction products in Jackass penguins using 2550F-2718R and P2/P8 primer sets showed one band in both males and females. Moreover, 2550F-2718R primer set identified the sex of chickens but not in ducks while primer P2/P8 showed only one band in both chickens and ducks. The 1272L-1237H primer showed one band in male and two bands in female in all species tested. It was confirmed that the use of 1272L-1237H primer concur in identifying the sex of the following species: Jackass penguins, ducks and chickens.

Electron transfer-initiated epoxidation and isomerization chain reactions of β-caryophyllene.

The abundant sesquiterpene β-caryophyllene can be epoxidized by molecular oxygen in the absence of any catalyst. In polar aprotic solvents, the reaction proceeds smoothly with epoxide selectivities exceeding 70 %. A mechanistic study has been performed and the possible involvement of free radical, spin inversion, and electron transfer mechanisms is evaluated using experimental and computational methods. The experimental data-including a detailed reaction product analysis, studies on reaction parameters, solvent effects, additives and an electrochemical investigation-all support that the spontaneous epoxidation of β-caryophyllene constitutes a rare case of unsensitized electron transfer from an olefin to triplet oxygen under mild conditions (80 °C, 1 bar O2 ). As initiation of the oxygenation reaction, the formation of a caryophyllene-derived radical cation via electron transfer is proposed. This radical cation reacts with triplet oxygen to a dioxetane via a chain mechanism with chain lengths exceeding 100 under optimized conditions. The dioxetane then acts as an in situ-formed epoxidizing agent. Under nitrogen atmosphere, the presence of a one-electron acceptor leads to the selective isomerization of β-caryophyllene to isocaryophyllene. Observations indicate that this isomerization reaction is a novel and elegant synthetic pathway to isocaryophyllene.

Statistical product distributions for ultracold reactions in external fields

The main limitation of most ultracold chemistry studies to date is the lack of an analysis of reaction products. Here, we discuss a generally tractable, rigorous theoretical framework for computing statistical product-state distributions for ultracold reactions in external fields. We show that fields have two main effects on the products of a statistical reaction, by (1) modifying the product energy levels and thus potentially reshaping the product distributions and/or (2) adding or removing product states by changing the reaction exothermicity. By analyzing these effects and the strength of the formalism to distinguish between different reaction mechanisms in benchmark reactions involving $^{40}\mathrm{K}$ and $^{87}\mathrm{Rb}$ species, we argue that statistical predictions will help understanding product formation and control, and lead developments to realize the full potential of ultracold chemistry.

Eksplorasi Senyawa-senyawa P-Mentan-3-OL Melalui Reaksi Katalitik Terhadap Sitronelal Menggunakan Katalis Cu/ZnBr2/gamma-Al203 dan Gas N2 dan H2

Exploration compound p-menthan-3-ol has been carried out using Cu/ZnBr 2 /γ-Al­ 2 O 3 as a catalyst in N2 and H2 atmospheric gases. This research was done in several stages that is Cu/ZnBr 2 /γ-Al­ 2 O 3 catalyst preparation, catalyst characterization, and catalytic reactions toward citronellal. Impregnation of Cu (NO 3 ) 2 .3H 2 O in ZnBr 2 /γ-Al­ 2 O 3 wasperformed in methanol as a solvent for Cu/ZnBr 2 /γ-Al­ 2 O 3 catalyst preparation. Stage was followed by a catalytic reaction to citronellal that performed in a glass reactor modification with atmospheric gases H 2 ; N 2 and H 2 at 90 O C temperature variations and 120 O C. Catalyst characterizations was performed using XRD and SEM - EDX, so it could be seen with either Cu was impregnated on ZnBr 2 /γ-Al­ 2 O 3 . Gas chromatography (GC) and gas chromatography - mass spectrum (GC-MS) was used to determine the activity of the catalyst through a catalytic reaction product analysis. Isopulegol was obtained from the product p- menthan-3-ol with a selectivity of 37.75 % in H 2 gas atmosphere at a temperature of 120 O C for 4 hours, and isopulegol selectivity was obtained in atmospheric gases N 2 : H 2 = 3:2 at a temperature of 120 O C with reaction time of 4 hours was equal to 25.82 % .

Fuel retention measurements in Alcator C-Mod using accelerator-based in situ materials surveillance

This paper presents the first in situ time- and space-resolved measurements of deuterium (D) fuel retention in plasma-facing component (PFC) surfaces using Accelerator-based In-situ Materials Surveillance (AIMS) on the Alcator C-Mod tokamak. AIMS is a novel in situ materials diagnostic technique based on the spectroscopic analysis of nuclear reaction products induced in PFC surfaces using an ∼MeV beam of deuterons from a compact linear accelerator in between plasma shots. AIMS measurements of D retention on inner wall PFCs were acquired during diverted and limited plasma operations and during wall conditioning experiments. Intershot measurements demonstrate the local erosion and codeposition of boron films on PFC surfaces with a constant D/B ratio. This is consistent with previous results suggesting that D codeposition with boron is insufficient to account for the net retention observed in Alcator C-Mod. Changes in deuterium concentration during boronization, electron cyclotron and glow cleanings were also measured.

Flagellin typing of Bordetella bronchiseptica strains originating from different host species

Bordetella bronchiseptica is a widespread Gram-negative pathogen occurring in different mammal species. It is known to play a role in the aetiology of infectious atrophic rhinitis of swine, canine kennel cough, respiratory syndromes of cats, rabbits and guinea pigs, and sporadic human cases have also been reported. In this study, 93 B. bronchiseptica strains were examined from a broad range of host species and different geographical regions using restriction fragment length polymorphism analysis of polymerase chain reaction products of flaA to reveal the possible host-specificity of the flagellin. Eight types (A–H) of flaA were identified, including five newly described ones (D–H). All but one of the 22 B. bronchiseptica strains from swine showed type B fragment pattern. The eighteen Hungarian isolates of canine origin were uniform (type A) while in other countries type B and D were also present in dogs. The sequence and phylogenetic analysis of 36 representative strains of flaA types revealed four clusters. These clusters correlated with flaA PCR-RFLP types and host species, especially in pigs and dogs. The revealed diversity of the strains isolated from human cases indicated possible zoonotic transmissions from various animal sources.

In vitro antibacterial analysis of phenoloxidase reaction products from the sea cucumber Apostichopus japonicus

Three phenoloxidases (POs) of Apostichopus japonicus, AjPOs (AjPO1, AjPO2 and AjPO3), were partially purified from the coelomocytes with an electrophoretic method, and then employed for the in vitro antibacterial analysis. Using L-3,4-dihydroxyphenylalanine (L-DOPA) as a substrate, AjPO1 and AjPO2-derived compounds inhibited the growth of Vibrio splendidus and Staphylococcus aureus, while AjPO3-derived compounds only inhibited the growth of V. splendidus. When dopamine was used as a substrate, AjPO1 and AjPO3-derived compounds inhibited the growth of V. splendidus and Vibrio harveyi, while AjPO2-derived compounds only inhibited the growth of V. splendidus. Moreover, AjPO1-derived compounds showed stronger inhibition in V. harveyi than AjPO3-derived compounds did. However, all of the three AjPO reaction products showed no inhibitions on the growth of Pseudoalteromonas nigrifaciens, Shewanella baltica, Micrococcus lysodeikticus, Streptococcus dysgalactiae and Nocardiopsis sp. with L-DOPA or dopamine as a substrate. Scanning electron microscope (SEM) observation of V. harveyi treated by AjPOs and dopamine showed that AjPO1-derived compounds resulted in massive bacteriolysis, AjPO2-derived compounds caused no obvious alteration on bacterial morphology, and AjPO3-derived compounds increased the ratio of spheroidal bacteria. All these results suggested that AjPO reaction products derived by L-DOPA and dopamine had different but limited antibacterial spectrum, and the different antibacterial effects observed among three AjPOs resulted from the different reaction products generated by AjPOs with the same substrate.

Nucleophilic conjugate 1,3-addition of phosphines to oligoynoates.

Herein we have elucidated unusual and unique nucleophilic conjugate 1,3-addition reactions of surveyed oligoynoates toward phosphines through spectroscopic and single crystal X-ray diffraction analyses of three-component reaction products of oligoynoates, phosphines and aldehydes.