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'Phosphates' in keywords
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1Author    Giorgio Concas, Giorgio Spano, Marzia Carrada, Marco Bettinelli, Adolfo SpeghiniRequires cookie*
 Title    Local Structure of Europium Sites in Oxide Glasses by Nuclear Gamma Resonance  
 Abstract    The symmetry and disorder of the Eu 3+ site was investigated in some phosphate and borate glasses by means of 151 Eu Mössbauer spectroscopy. The quadrupole interaction parameter, which is due to the distortion of the Eu site compared to a cubic symmetry, has been measured together with the asymmetry parameter, which points out the absence of a threefold or fourfold axis of symmetry at the rare earth site. The correlation of the isomer shift with the optical basicity of the glass indicates a covalent component with 6s character in the Eu-0 bond. The axial component of the electric field gradient at the Eu site is also correlated with the optical basicity. 
  Reference    Z. Naturforsch. 54a, 539—544 (1999); received August 5 1999 
  Published    1999 
  Keywords    Europium, Oxide Glasses, Phosphates, Borates, 15 'Eu Mössbauer Spectroscopy 
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 TEI-XML for    default:Reihe_A/54/ZNA-1999-54a-0539.pdf 
 Identifier    ZNA-1999-54a-0539 
 Volume    54 
2Author    A. Chrissanthopoulos3, C. Pouchan3, G. N. Papatheodorou5Requires cookie*
 Title    Structural Investigation of Vanadium -Sodium Metaphosphate Glasses  
 Abstract    Paper presented a t the NATO A dvanced Study Institute, M ay 4-1 4 , 2001 (Kas, Turkey) The structure of the glass forming system (V20 5)x -(Na20 • P205)(1_^), (jc = 0-0.4), has been inves­ tigated using Raman spectroscopy. The stretching vibrations of various phosphate groups, connected to phosphorus or vanadium atoms, have been assigned. Variation o f the composition leads to structural changes where the sodium metaphosphate -P-O-P-chains break and then reconnect with the oxovana-dium units forming a -V-O-P-network structure. 
  Reference    Z. Naturforsch. 56a, 773—7 (2001); received August 8 2001 
  Published    2001 
  Keywords    Vanadium, Phosphates, Vanadium Glass, Raman Spectroscopy, Metaphosphates 
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 TEI-XML for    default:Reihe_A/56/ZNA-2001-56a-0773.pdf 
 Identifier    ZNA-2001-56a-0773 
 Volume    56 
3Author    Requires cookie*
 Title    Transphosphorylative Spin-Labeling Utilizing Diimidazolides of Pentavalent Phosphorus  
 Abstract    G e o r g e S o s n o v s k y a n d M a r i a K o n i e c z n y The reaction of the spin-labeled diimidazolide 1 with hydroxy and amino compounds was studied. Diimidazolide 1 was superior to the dichloridate 6 for the preparation of spin-labeled phosphates 3 and phosphorodiamidates 2. The spin-labeled phosphate 15 was synthesized through hydrolysis of 6 . Spin-labeled cyclophosphoramidates (10-13), analogs of the cytotoxic Endoxan, were prepared by the reaction of 1 and 6 with the appropriate difunctional nucleophile. Inductive effects of substituents in the imidazolyl m oiety on the transphosphorylation reaction were also studied. 0 0 0 0 R0p { N ^ f) 2 R O P (N r'r2)2 R 0P(0R> 2 RO PCIj I 2 3 6 0 o 1 1 / N OP (CH2)n N H 10 (n • 2 ,3) H 0 • II ,0 ROP r i i CH, ROP, n ' x h , 13 
  Reference    (Z. Naturforsch. 32b, 1048—1059 [1977]; received May 9 1977) 
  Published    1977 
  Keywords    Spin-labeled Imidazolides, Phosphates, Cyclophosphoramidates, Transphosphorylation, Phosphorodiamidates 
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 TEI-XML for    default:Reihe_B/32/ZNB-1977-32b-1048.pdf 
 Identifier    ZNB-1977-32b-1048 
 Volume    32 
4Author    HeinzP. Fritz, JordanisC G Thanos, DietrichW. WabnerRequires cookie*
 Title    Electrochemical Syntheses, XVII [1] Ozone Synthesis by Electrolysis of Water  
 Abstract    Dimensionally stable lead dioxide anodes on a titanium substrate [2, 3] were tested for application in ozone electrosynthesis in a variety of aqueous electrolytes. At room tem-perature an ozone concentration of up to 13% by weight in the anodic gas composed of O3 and O2 is attained by using an aqueous phosphate electrolyte. 
  Reference    Z. Naturforsch. 34b, 1617—1627 (1979); received August 16 1979 
  Published    1979 
  Keywords    Ozone, Electrosynthesis, Lead Dioxide, Sulphate, Phosphate 
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 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-1617.pdf 
 Identifier    ZNB-1979-34b-1617 
 Volume    34 
5Author    D. Frerichs, Hk Müller-BuschbaumRequires cookie*
 Title    Vier verschiedene Koordinationspolyeder um Cu2+ im Oxid-Arsenat-Phosphat Cu0  
 Abstract    (Cu,M g)3(As1_xPJt:0 4)2 (x = 0,3) Four Different Coordination Polyhedra Around Copper in the Oxide-Arsenate-Phosphate C u0(C u,M g)3(A s,_xP,.04)2 (x = 0.3) Single crystals of CuO(Cu,Mg)3[(As0.7P0.3)O4]2 have been prepared by crystallization from melts. The compound crystallizes with triclinic symmetry, space group C '-P l, a = 6.372(4), b = 7.643(7), c = 8.175(5) A, a = 98.59(6), ß = 112.26(3), 7 = 99.03(3)°, Z = 2. CuO(Cu,Mg)3[(Aso)7Po 3)0 4]2 is isotypic to Cu4(P 0 4)20 . X-ray investigations show square planar C u 04 polygons, twisted tetragonal C u 0 5 pyramids, C u 05 bipyramids and elongated (Cu,M g)06 octahedra. 
  Reference    (Z. Naturforsch. 51b, 25—28 [1996]; eingegangen am 27. Juli 1995) 
  Published    1996 
  Keywords    Copper, Magnesium, Arsenate, Phosphate, Crystal Structure 
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 TEI-XML for    default:Reihe_B/51/ZNB-1996-51b-0025.pdf 
 Identifier    ZNB-1996-51b-0025 
 Volume    51 
6Author    K. Bluhm, C. H. ParkRequires cookie*
 Title    Die Synthese und Kristallstruktur des Borat-Phosphats: a -Zn3(B0 3)(P04) Synthesis and Crystal Structure of the Borate-Phosphate: Q-Zn3(B 0 3)( P 0 4)  
 Abstract    Single crystals of the compound a -Z n 3(B 0 3)(P 0 4) were obtained at 1050 °C by using B20 3, P20 5 and Z n C 0 3 as starting materials and subsequent cooling to 600°C with 20°C/h. X-ray investigations on single crystals yield a new crystal structure in the monoclinic space group Cm -(Nr. 8) with a = 972.5(2); b = 1272.0(3); c = 487.4(3) pm; 0 = 1 1 9 .8 0 (4)°; Z = 4. The structure contains isolated trigonally planar B 0 3 and tetrahedral P 0 4 units which are not joined together. Zinc occupies three crystallographically different point positions and is trigonal-bipyramidally, tetragonal-pyramidally or distorted tetrahedrally coordinated by oxygen. 
  Reference    (Z. Naturforsch. 52b, 102—106 [1997]; eingegangen am 16. August 1996) 
  Published    1997 
  Keywords    Zinc, Borate, Phosphate, Synthesis, Crystal Structure 
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 TEI-XML for    default:Reihe_B/52/ZNB-1997-52b-0102.pdf 
 Identifier    ZNB-1997-52b-0102 
 Volume    52 
7Author    PierreM. Ermier, Wilhelm HasselbachRequires cookie*
 Title    The Effect of Calcium and Phosphate on the Biphasic Calcium Uptake by the Sarcoplasmic Reticulum  
 Abstract    The amplitude of the fast uptake and the initial rate of the slow uptake increase with in­ creasing free calcium concentrations, up to 30 [xu. In that range, both processes are correlated to each other. At higher concentrations, the slow uptake is more inhibited than the fast uptake. The fast uptake shows a maximum amplitude which remains unchanged in the presence of phosphate. The slow uptake leads to a nearly complete depletion of the external calcium, and its rate is pro­ portional to the phosphate concentration, even at physiological range. The sarcoplasmic ATPase liberates inorganic phosphate and the slow uptake 
  Reference    (Z. Naturforsch. 30c, 777 [1975]; received July 17 1975) 
  Published    1975 
  Keywords    Sarcoplasmic Reticulum, Calcium, Phosphate, Flow Dialysis 
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 TEI-XML for    default:Reihe_C/30/ZNC-1975-30c-0777.pdf 
 Identifier    ZNC-1975-30c-0777 
 Volume    30 
8Author    Ryszard Stolarski, Piotr Lassota, Zygmunt Kazimierczuk, David ShugarRequires cookie*
 Title    Solution Conformations of Some Acyclo Nucleoside and Nucleotide Analogues of Antiviral Acyclonucleosides, and Their Substrate/Inhibitor Properties in Several Enzyme Systems  
 Abstract    Chemical and enzymatic procedures have been employed for the preparation of various phos-phorylated derivatives of the acyclonucleoside 9-(l,3-dihydroxy-2-propoxymethyl)adenine, an analogue of the active antiviral agent 9-(l,3-dihydroxy-2-propoxymethyl)guanine (DHPG). In combination with the previously reported 2',3'-seco nucleosides and their phosphates and cyclic phosphates (Stolarski et al., this made available a broad class of acyclonucleosides and nucleotides, the acyclic moieties of which are capable of mimicing the ribose and 2'-deoxyribose rings. The solution conformations of the foregoing were determined with the aid of 'H, 13 C and 31 P NMR, and compared with those of DHPG and 9-(hydroxyethoxymethyl)guanine (Acyclovir, ACV). Particular attention was devoted to conformations about C-O bonds in different acyclic fragments, which demonstrated well-defined differences between 2',3'-seco derivatives on the one hand (conformational "rigidity") and derivatives with DHP and AC acyclic chains on the other (rotation about the C(l')-0(4') bond). The overall results are in good general agreement with reported crystal structures, and are compared with those obtained by quantum mechanical calcu-lations. The conformational features of the various compounds are also discussed in relation to their substrate and/or inhibitor properties in a number of enzyme systems, including adenosine deamin-ase, phosphodiesterases, nuclease PI, 3'-nucleotidase and herpes virus type 1 thymidine kinase. Abbreviations: AC, 2-hydroxyethoxymethyl; DHP, 1,3-di-hydroxy-2-propoxymethyl; seco, 2',3'-seco or 1,5-dihydro-4-hydroxymethyl-3-oxapentyl-2-[R]; ACV, Acyclovir or AcycloG, 9-(2-hydroxyethoxymethyl)guanine; ACVMP, monophosphate of ACV; AC-Cyt, l-(2-hydroxyethoxy-methyl)cytosine, with similar connotations for AC-Ade and AC-Ura; DHPG, 9-(l,3-dihydroxy-2-propoxymethyl)-guanine; DHP-Ade, adenine analogue of DHPG; DHPGMP, monophosphate of DHPG; DHP-AdeMP, monophosphate of DHP-Ade; DHP-Ade-diP, 3',5'-diphosphate of DHP-Ade; DHP-Ade-3' : 5'-cMP, the 3':5'-cyclic monophosphate of DHP-Ade; secoA, 2',3'-secoadenosine or 9-(l,5-dihydro-4-hydroxymethyl-3-oxa-pentyl-2-[R])adenine, with similar connotations for other acyclonucleosides; seco-5'-GMP, 5'-monophosphate of secoG, and similarly for seco-5'-CMP and seco-5'-AMP; secoC-3' :5'-cMP, 2',3'-secocytidine-3' :5'-cyclic phos-phate, and similarly for secoA-3':5'-cMP; TK, thymidine kinase; cPDase, cyclic nucleotide phosphodiesterase. For purposes of simplicity, the abbreviated terms are used in the text, with the carbon atoms of the acyclic chains numbered as for the corresponding carbon atoms of the pentose ring, as shown in Scheme 1. 
  Reference    Z. Naturforsch. 43c, 231—242 (1988); received December 3 1987 
  Published    1988 
  Keywords    Acyclonucleosides, Phosphates, Cyclic Phosphates, Solution Conformations, Substrate/Inhibitor Properties 
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 TEI-XML for    default:Reihe_C/43/ZNC-1988-43c-0231.pdf 
 Identifier    ZNC-1988-43c-0231 
 Volume    43