| 11. |
- Abt, I, et al.
(författare)
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Measurement of the b(b)over-bar production cross section in 920 GeV fixed-target proton-nucleus collisions
- 2003
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 26:3, s. 345-355
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Tidskriftsartikel (refereegranskat)abstract
- Using the HERA-B detector, the b (b) over bar production cross section has been measured in 920 GeV proton collisions on carbon and titanium targets. The b (b) over bar production was tagged via inclusive bottom quark decays into J/psi by exploiting the longitudinal separation of J/psi --> l(+)l(-) decay vertices from the primary proton-nucleus interaction. Both e(+)e(-) and mu(+)mu(-) channels have been reconstructed and the combined analysis yields the cross section sigma(b (b) over bar) = 32(-12)(+14)(stat) (+6)(-7)(sys) nb/nucleon.
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| 12. |
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| 13. |
- Zhu, Bin, et al.
(författare)
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Innovative low temperature SOFCs and advanced materials
- 2003
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Ingår i: Journal of Power Sources. - 0378-7753 .- 1873-2755. ; 118:02-jan, s. 47-53
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Tidskriftsartikel (refereegranskat)abstract
- High ionic conductivity, varying from 0.01 to 1 S cm(-1) between 300 and 700 degreesC, has been achieved for the hybrid and nano-ceriacomposite electrolyte materials, demonstrating a successful application for advanced low temperature solid oxide fuel cells (LTSOFCs). The LTSOFCs were constructed based on these new materials. The performance of 0.15-0.25 W cm(-2) was obtained in temperature region of 320400 degreesC for the ceria-carbonate composite electrolyte, and of 0.35-0.66 W cm(-2) in temperature region of 500-600 degreesC for the ceria-lanthanum oxide composites. The cell could even function at as low as 200 degreesC. The cell has also undergone a life test for several months. A two-cell stack was studied, showing expected performance successfully. The excellent LTSOFC performance is resulted from both functional electrolyte and electrode materials. The electrolytes are two phase composite materials based on the oxygen ion and proton conducting phases, or two rare-earth oxides. The electrodes used were based on the same composite material system having excellent compatibility with the electrolyte. They are highly catalytic and conductive thus creating the excellent performances at low temperatures. These innovative LT materials and LTSOFC technologies would open the door for wide applications, not only for stationary but also for mobile power sources.
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| 14. |
- Chen, C. N., et al.
(författare)
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Aggregate manganese Schiff base moieties by terephthalate or acetate : Dinuclear manganese and trinuclear mixed metal Mn-2/Na complexes
- 2003
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 42:11, s. 3540-3548
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Tidskriftsartikel (refereegranskat)abstract
- A reaction system consisting of terephthalic acid, NaOH, inorganic Mn(II) or Mn(III) salt, and salicylidene alkylimine resulted in dinuclear manganese complexes (salpn)(2)Mn-2(mu-phth)(CH3OH)(2) (1, salpn = N,N'-1,3-propylene-bis(salicylideneiminato); phth = terephthalate dianion), (salen)(2)Mn-2(mu-phth)(CH3OH)(2) (2, salen = N,N'-ethylene-bis(salicylideneiminato)), (salen)(2)Mn-2(mu-phth)(CH3OH)(H2O) (3), and (salen)(2)Mn-2(mu-phth) (4), while the absence of NaOH in the reaction led to a mononuclear Mn complex (salph)Mn(CH3OH)(NO3) (5, salph = N,N'-1,2-phenylene-bis(salicylideneiminato)). In addition, a trinuclear mixed metal complex H{Mn2Na(salpn)(2)(mu-OAc)(2)(H2O)(2)}(OAc)(2) (6) was obtained from the reaction system by using maleic acid instead of terephthalic acid. Five-coordinate Mn ions were found in 4 giving rise to an intermolecular interaction and constructing a one-dimensional linear structure. Antiferromagnetic exchange interactions were observed for 1-3, and a total ferromagnetic exchange of 4 was considered to stem from intermolecular magnetic coupling. H-1 NMR signals of phenolate ring and alkylene (or phenylene) backbone of the diamine are similar to those reported in the literature, and the phth protons are at -2.3 to -10.1 ppm. Studies on structure, bond valence sum analysis, and magnetic properties indicate the oxidation states of the Mn ions in 6 to be +3, which are also indicated by ESR spectra in dual mode. Ferromagnetic exchange interaction between the Mn(III) sites was observed with J = 1.74 cm(-1). A quasireversible redox pair at -0.29V/0.12V has been assigned to the redox of Mn-2(III)/Mn(III)Mn(II), implying the intactness of the complex backbone in solution.
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| 15. |
- Haraldsen, P, et al.
(författare)
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Multimodal management - of value in fulminant acute pancreatitis?
- 2003
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Ingår i: Pancreatology. - : Elsevier BV. - 1424-3903. ; 3:1, s. 14-25
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedBackground: The multiple organ dysfunction syndrome (MODS) is the major cause of morbidity and mortality associated with acute pancreatitis. Presently, therapy is merely organ supportive as no effective therapy against underlying causative pathophysiologicla mechanisms exists. Aims: To evaluate the effect of treatmetn with a platelet-activating factor inhibitor (PAFI), a monoclonal antibody against platelet endothelial cell adhesion molecule (PECAM-1-MAb) and an oxygen free radical scavenger (N-acetylcystein; NAC), alone or in combination, on systemic organ dysfunction in experimental acute pancreatitis. Methods: Severe acute pancreatitis induced in rats by the intraductal administration of tauro-deoxycholate. Treatment was given after 1 or 3 h, and evaluations were performed 6 h after induction. Organ dysfunction was evaluated by means of endothelial integrity impairment expressed as endothelial barrier leakage index. Results: Severe acute pancreatitis caused a significant impairment in endothelial integrity in all organs studied and decreased levels of protease inhibitors compared to controls. The endothelial barrier impairment was significantly ameliorated by all treatment modalities, either given early or later. Combinations of NAC and the PECAM-1-MAb or the PECAM-1-MAb and the PAFI were the only schedules to restore endothelial barrier integrity to normal levels in most of the organs studied. Conclusion: Combination therapy with NAC and PECAM-1-MAb and/or PAFI may offer effective, causative-directed supplements to organ-supportive therapy of MODS in severe acute pancreatitis.
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| 16. |
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| 17. |
- Huang, D. G., et al.
(författare)
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Synthesis, structural characterizations and magnetic properties of a series of mono-, di- and polynuclear manganese pyridinecarboxylate compounds
- 2004
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Ingår i: European Journal of Inorganic Chemistry. - : Wiley. - 1434-1948 .- 1099-1948 .- 1099-0682. ; :7, s. 1454-1464
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Tidskriftsartikel (refereegranskat)abstract
- Seven new manganese(II, III, IV) pyridinecarboxylate compounds (Et4N)[MnCl2(pic)(2)] (1, Hpic = picolinic acid) [MnCl(Pic)(2)(H2O)].H2O (2), [MnCl(pic)(H2O)2](n) (3), [Mn(Pic)(2)](n) (4), [MnCl(pic)](n) (5), [MnCl2(4-C5H4NHCOO)](n) (6) and [Mn2O2(pic)(4)] (7) were synthesized and structurally characterized. The picolinate ligand coordinates to the Mn ion forming a chelating five-membered ring which constructs diverse architectures by various bridging modes, such as mu-Cl, mu(1,1)(-) and mu(1,3)-carboxylate bridges (syn-syn and syn-anti modes). The interaction between the pyridyl rings is discussed, displaying a face-to-face pi-pi stacking for complex 6 and a T-shaped C-H...pi attraction for complex 4. Complex 3 has an infinite zigzag chain structure in which two neighboring Mn ions are linked by a carboxylate bridge in a syn-anti mode. In complex 4, the Mn(pic)(2) fragments are joined to each other by double mu(1,1)-carboxylate bridges, forming a 2D layer structure. Complex 5 contains Mn4O4 square subunits which are connected by double mu-Cl bridges to form a grid-like 2D structure. The isonicotinate complex 6 has a zigzag chain structure containing mixed double mu-Cl and mu(1,3)-carboxylate bridges in a syn-syn mode. Protonation at the pyridyl-N position was found and identified by the IR and magnetic properties of 6. The participation of an oxidizing agent like MnO4- leads to complexes containing higher valent manganese (1, 2 and 7). The IR spectra of these complexes are discussed and found to be consistent with the structural features. The magnetic properties of complexes 4, 5 and 6 have been investigated. Antiferromagnetic coupling interactions were observed and satisfactory fitting results were obtained with J values ranging from -0.63 cm(-1) to -2.35 cm(-1). The magnetic parameters of these complexes, together with the parameters of other Mn complexes with comparable structures, are compared and discussed based on the bridging modes. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).
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| 18. |
- Huang, D. U., et al.
(författare)
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Synthesis, structural characterization and magnetic properties of 2-pyrazinecarboxylate manganese compounds Mn(pyz)(2)(H2O)(4) and MnCl(pyz)(H2O) (n) (pyz=2-pyrazinecarboxylate)
- 2003
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Ingår i: Inorganica Chimica Acta. - 0020-1693 .- 1873-3255. ; 353, s. 284-291
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Tidskriftsartikel (refereegranskat)abstract
- Two pyz complexes [Mn(pyz)(2)(H2O)(4)] (1) and [MnCl(pyz)(H2O)] (2) have been synthesized and structurally characterized. Complex 1 contains an eight-coordinate Mn(II) ion with square anti-prismatic geometry. The extensive intermolecular hydrogen-bonding interactions of O-carboxyl...H-O-aqua correlate the complex molecules, forming 2D polymeric layer structure. The structure of complex 2 contains 1D Mn/pyz chains, which link to each other by double mu(2)-Cl bridges to form 2D layer with Mn...Mn distance of 3.664 Angstrom. Hydrogen-bonding interactions of O-carboxyl...H-O-aqua are found between the layers to correlate the 2D layers to form a 3D framework. In addition, the variable temperature magnetic susceptibilities of complex 2 were measured and weak ferromagnetic exchange interactions between the neighboring magnetic species were found with J = 0.42 cm(-1).
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| 19. |
- Li, D. Z., et al.
(författare)
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Study of interaction between red-tide toxin, domoic acid and double-stranded DNA by capillary zone electrophoresis
- 2004
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Ingår i: Chinese Chemical Letters. - 1001-8417 .- 1878-5964. ; 15:9, s. 1079-1082
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Tidskriftsartikel (refereegranskat)abstract
- The interactions between amnesic red-tide toxin, domoic acid (DA) and 14mer double-stranded DNA (dsDNA with three kinds of sequences) were studied by capillary zone electrophoresis (CZE). For the dsDNA with a sequence of 5'-CCCCCTATACCCGC-3', the amount of free dsDNA decreases with the increase of added DA; and the signal of DA-dsDNA complex was observed. Meanwhile, the other two dsDNAs, 5'-(C)12GC-3' and 5'-(AT)7-3', the existence of DA could not lead to the change of dsDNA signal and indicated that there is no interaction between DA and these two dsDNAs.
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| 20. |
- Li, H. Y., et al.
(författare)
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Properties of a dinuclear Mn(III,III) complex with a tri-phenolate ligand N4O3 (3-) and a new complex containing a ligand covalently linked to ruthenium tris-bipyridine
- 2004
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Ingår i: Huaxue xuebao. - 0567-7351. ; 62:9, s. 916-922
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Tidskriftsartikel (refereegranskat)abstract
- A new high valent complex [Mn-2(III, III)L(mu-OAc)(2)].PF6 (2a) was prepared, where L was the trianion of 2, 6-bis {[(2-hydroxy-5-tert-butylbenzyl) (pyridyl-2-methyl)-amino]-methyl}-4-methylphenol, which contains two additional phenolate groups and two tert-butyl groups compared to its parent [Mn-2(II, II)(bpmp)(mu-OAc)(2)].ClO4 (1). These improvements narrowed the disparity between the new model and (Mn)(4) cluster (OEC in nature). Moreover, L was modified to be covalently linked with Ru(II) tris-bipyridine through an amide bond to construct a complex 2b for the study of photoinduced electron transfer (PET). UV-vis, IR, emission spectra and electrochemistry were used to investigate their photochemistry properties. The results showed that 2b has good photochemistry properties and the E-1/2 of Ru3+/Ru2+ was higher than those of phenol(+)/phenol and Mn(III, IV)/Mn(III, III). After coordination of manganese ions, the electron transfer process in the model complex conforms to the basic principles of electron donor side of photosystem II (PS II) in nature.
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