bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of x‐ray attenuation coefficients around K‐absorption edges using fe Kα x‐rays
Authors: Kerur B. R. , Thontadarya S. R. , Hanumaiah B. 
Published: May 2005

AbstractThe x‐ray mass attenuation coefficients were measured around the K‐absorption edges of elements in the range 16 ⩽ Z ⩽ 30 using Fe Kα x‐rays of energy 6.400 keV, which is the weighted average energy of Kα1 and Kα2 x‐ray components from the 57Co radioactive source. Kβ x‐rays were almost eliminated by the differential absorption technique. The small difference in energy between Kα1 and Kα2, 13 eV, was shown to be inconsequential by comparing the measured and theoretical values of μ/ρ for standard materials such as Al, Cu, Mo and Ta. The effect of fine structure of the K‐absorption edge on μ/ρ was elucidated by using the compounds of elements in the range 16 ⩽ Z ⩽ 30, containing one element with its K‐absorption edge energy (Ek) close to the incident photon energy (Ex). The results clearly indicate the validity of the theoretical mixture rule for all those compounds whose K edge is far away from the incident energy but show deviations of as much as 10% for the manganese compound whose K edge is 140 eV above Ex and about 12% for the chromium compound whose K edge is 410 eV below Ex. These deviations are attributed to the possible influence of resonance Raman scattering when the incident photon energy Ex is less than the edge energy and to the influence of EXAFS when Ex is more than the edge energy.
Measurement of total photoelectric cross‐sections for 52.4 keV photons
Authors: Jahagirdar H. A. , Hanumaiah B. , Thontadarya S. R. 
Published: May 2005

AbstractAccurate measurements (within 3.2%) of the total photoelectric cross‐sections of Ag, Sn and Ba for a 52.4 keV photon energy were made using an NaI(Tl) spectrometer system coupled to a 1K MCA in an extreme broad‐beam geometry configuration. The results were compared with their corresponding theoretical values and good agreement was obtained.
Vanadium metabolism in wild type and respiratory‐deficient strains of S. cerevisiae
Authors: Willsky Gail R. , Dosch Susan F. 
Published: May 2005

AbstractVanadium metabolism was studied in a wild type and respiratory‐deficient strains of S. cerevisiae. Inhibition of growth by vanadate [V(+5)], vanadate accumulation, and conversion of medium vanadate [V(+5)] to both cell‐associated and medium vanadyl [V(+4)] and vanadate [V(+5)] were compared. The growth of both the parental and respiratory‐deficient strains was inhibited by vanadate at concentrations greater than or equal to 1 mM. Both parental and respiratory‐deficient strains accumulated vanadate and converted medium vanadate to cellular vanadyl as detected using electron spin resonance (ESR). The accumulation of cell‐associated vanadyl was correlated with the loss of medium vanadate in both strains using a chemical assay. In contrast, the respiratory‐deficient strain showed a greater amount of a cell‐associated vanadate compound, as detected with vanadium‐51 nuclear magnetic resonance (51V‐NMR), than the wild strain or a representative respiratory‐competent vanadate‐resistant mutant. These data imply that mitochondrial function may be directly involved in vanadium metabolism.
Mechanism of inactivation of UDP‐glucose 4‐epimerase from Saccharomyces cerevisiac by D‐xylose and L‐arabinose
Authors: Cármenes Ricardo S. , Gascón Santiago , Moreno Fernando 
Published: May 2005

AbstractIn a previous paper (Cármenes et al., 1984) we reported that UDP‐glucose 4‐epimerase from Saccharomyces was inactivated both in vitro (Crude extracts) by L‐arabinose or D‐xylose. In this paper, we reported that pure epimerase requires the presence of UMP or UDP to be inactivated by sugars and that the inactivation is due to the reduction of the epimerase NAD+, which is essential for epimerase activity. The inactivation rate is directly proportional to epimerase and sugar concentrations and hyperbolically proportional to UMP concentration. In situ experiments made with permeabilized cells showed that epimerase is inactivated in the same way when it is inside the cell. In vivo studies showed that epimerase is inactivated to a smaller extent when 1% Dgalactose is present in the culture medium than when 1% ethanol is the main carbon source.
Characterization of plasma membrane H+‐ATPase from salt‐tolerant yeast Candida versatilis
Authors: Watanabe Yasuo , Yamaguchi Masahiro , Sakamoto Jun , Tamai Youichi 
Published: May 2005

AbstractPlasma membrane was isolated from the salt‐tolerant yeast Candida versatilis and the ATPase in plasma membrane was characterized. The ATPase was a typical H+‐ATPase with similar properties to the Saccharomyces cerevisiae and Zygosaccharomyces rouxii enzymes. It was reacted with antibody (IgG) raised against S. cerevisiae plasma membrane H+‐ATPase. The ATPase activity was not changed by adding NaCl and KCl to the assay solutions, but was increased by NH, especially by ammonium sulfate. In vivo stimulation of ATPase activity was observed by the addition of NaCl into the culture medium, as observed in Z. rouxii. No in vivo activation of H+‐ATPase by glucose metabolism was observed in C. versatilis cells and the activity was independent of the growth phase, like Z. rouxii and unlike S. cerevisiae cells.
Role of the γ component of preprotoxin in expression of the yeast K1 killer phenotype
Authors: Zhu Yun‐Song , Kane Jeff , Zhang Xia‐Ying , Zhang Meng , Tipper Donald J. 
Published: May 2005

AbstractK1 killer strains of Saccharomyces cerevisiae secrete a polypeptide toxin to which they are themselves immune. The α and β components of toxin comprise residues 45–147 and 234–316 of the 316‐residue K1 preprotoxin. The intervening 86‐residue segment is called γ. A 26‐residue signal peptide is removed on entry into the endoplasmic reticulum. The Kex2 protease excises the toxin components from the 290‐residue glycosylated protoxin in a late Golgi compartment. Expression of a cDNA copy of the preprotoxin gene confers the complete K1 killer phenotype on sensitive cells. We now show that expression of immunity requires that α component and the N‐terminal 31 residues of γ. An additional C‐terminal extension, either eight residues of γ or three of four unrelated peptides, is also required. Expression of preprotoxin terminating at the α C‐terminus, or lacking the γ N‐terminal half of γ causes profound but reversible growth inhibition. Inhibition is suppressed in cis by the same 31 residues of γ required for immunity to exocellular toxin in trans, but not by the presence of β. Both immunity and growth inhibition are alleviated by insertions in α that inactivate toxin. Inhibition is not suppressed by kex2, chc1 or kre1 mutations, by growth at higher pH or temperature, or by normal K1 immunity. Inhibition, therefore, probably does not involve processing of the α toxin component at its N‐terminus or release from the cell and binding to glucan receptors. Some insertion and substitution mutations in γ severely reduce toxin secretion without affecting immunity. They are presumed to affect protoxin folding in the endoplasmic reticulum and translocation to the Golgi.
Transcriptional studies on yeast SEC genes provide no evidence for regulation at the transcriptional level
Authors: Vahlensieck Yvonne , Riezman Howard , Meyhack Bernd 
Published: May 2005

AbstractA number of proteins have been identified as components of the secretory pathway of Saccharomyces cerevisiae (SEC gene products). However, very little is known about the expression of these components and their regulation at the transcriptional level. In this study yeast cells were exposed to conditions that changed the secretory activity of the cells. The conditions analysed include the different stages of the cell cycle, overexpression of secretory proteins, and block of secretion and endocytosis. The effect of these conditions on the transcriptional expression levels of a number of SEC genes (SAR1, SEC1, SEC14, SEC17, SEC18, SEC23, SEC62, YPT1) was analysed. In summary, no major changes in transcriptional expression levels could be detected. From these results we conclude that the components of the secretory pathway are expressed constitutively and that no general regulation of transcription exists, that could adjust the expression level of the SEC genes to the secretory activity of the cells.
The effect of ethanol and specific growth rate on the lipid content and composition of Saccharomyces cerevisiae grown anaerobically in a chemostat
Authors: Arneborg Nils , Høy Carl‐Erik , Jørgensen O. B. 
Published: May 2005

AbstractThe effects of produced ethanol and specific growth rate on the lipid content and composition of Saccharomyces cerevisiae CBS 2806 were studied using anaerobic chemostat cultures. The cells adapted to increased concentrations of produced ethanol by increasing the proportion of ergosterol at the expense of lanosterol, by increasing the proportion of phosphatidylinositol at the expense of phosphatidylcholine, and by increasing the amount of C18:0 fatty acids in total phospholipids at the expense of C16:0 fatty acids. The produced ethanol had no effect on the phospholipid content nor on the proportion of unsaturated fatty acids in the phospholipids.The specific growth rate had no effect on the phospholipid content, the sterol composition, the phospholipid composition, the fatty acid composition of total phospholipids, or on the proportion of unsaturated fatty acids in the phospholipids of S. cerevisiae. It was not possible to separate the effects of produced ethanol and growth rate on the ergosterol content of the chemostat‐grown S. cerevisiae cells.
Chemischer Transport fester Lösungen. 18 [1] Der Chemische Transport von ZnIn2S4, ZnIn2Se4 und ZnIn2S4−xSex‐Mischphasen
Authors: Locmelis S. , Milke E. , Binnewies M. , Gruhl S. , Vogt C. 
Published: May 2005

Chemical Vapor Transport of Solid Solutions. 18. [1] Chemical Vapor Transport of ZnIn2S4, ZnIn2Se4 and ZnIn2S4−xSex‐mixed CrystalsBy means of CVT methods using iodine as transport agent (725 → 675 °C) ZnIn2S4, ZnIn2Se4 und ZnIn2S4−xSex‐mixed phases could be obtained. Mass spectrometric investigations show the formation of ZnI2(g) and InI3(g) are due to the transport reaction. The transport process leads to a significant enrichment of sulphur.
Chemischer Transport fester Lösungen. 19 [1] Der Chemische Transport von Mischphasen im System Ga2S3/Ga2Se3
Authors: Hotje U. , Wartchow R. , Milke E. , Binnewies M. 
Published: May 2005

Chemical Vapor Transport of Solid Solutions. 19, Chemical Vapor Transport of Mixed Phases in the Systems Ga2S3/Ga2Se3By means of CVT methods using iodine as transport agent (950 → 800 °C) in the system Ga2S3/Ga2Se3 mixed crystals could be prepared. The miscibility gap, given in the literature, could not be observed, but the phase transition between a monoclinic (Ga2S3) and cubic (Ga2Se3) phase. The powder diffraction patterns of the mixed phases with the compositions Ga2S2,4Se0,6 und Ga2S0,6Se2,4 can be indexed hexagonally. The transport process occurs congruently. Thermochemical calculations as well as mass spectrometric investigations show that GaI3 (solid: Ga2S3) and GaI/GaI3 (Ga2Se3) are the gaseous species, due to the transport process. A congruent transport of all mixed phases in this system could be observed.
M(S)2(I)2 (M=Zn, Cd) and Hg(S)3I Coordination Environment of Transition Metal Complexes – Synthesis, Spectral, and Single Crystal X‐ray Structural Investigations
Authors: Saravanan M. , Prakasam B. Arul , Ramalingam K. , Bocelli G. , Cantoni A. 
Published: May 2005

AbstractThree new transition metal complexes [Zn(bipyrtds)I2](1), [Cd(bipyrtds)I2] (2) and [Hg(pipdtc)I](3) (where bipyrtds = bipyrrolidine thiuamdisulfide and pipdtc = piperidinecarbodithioate) were prepared by the reaction of the corresponding biscarbodithioates with iodine and were characterized by elemental analysis, IR and NMR spectra. The structures of all the three complexes were determined by single crystal X‐ray crystallography. Compounds 1 and 2 contain four coordinated metal atoms and both ZnII and CdII complexes are isostrucutral. Interestingly, complex 3 was found to contain effectively four coordinated mercury atom as a dimer with a relatively long Hg‐S (3.084Å) bond. The IR studies are in keeping with the observed thioureide distances. 1H NMR spectra of 1 and 2 show clear differences in environments of α‐ and β‐CH2 protons. However, in 1 a broad signal was observed at 4.02 ppm for α‐protons and a multiplet at 2.10 for β‐protons. For 2, two triplets appeared at 4.26 and 4.03 ppm for α‐protons and two quintets appeared in the range of 2.18 and 2.28 ppm for β‐protons. Complex 3 gave three sets of signals. Variation of stereochemical environment with respect to α and β protons of the rings is very clearly observed in the NMR spectra.
Structure Investigations on 4‐Halo‐1,2,3,5‐dithiadiazolyl Radicals XCNSSN• (X = F, Cl, Br): The Shortest Intradimer S···S Distance in Dithiadiazolyl Dimers
Authors: Knapp Carsten , Lork Enno , Gupta Kumar , Mews Rüdiger 
Published: May 2005

AbstractCrystals of the 4‐halo‐1,2,3,5‐dithiadiazolyl radicals (X = F, Cl, Br) were obtained by sublimation at 80 °C and 10−2 Torr, and the structures were determined by X‐ray diffraction. The fluoro derivative crystallizes as a cisoid dimer in the space group P21/n, whereas the chloro and bromo derivatives crystallize isomorphous as twisted dimers in the space group C2/c. The chloro and bromo derivatives show the shortest intradimer S···S contacts of all known 1,2,3,5‐dithiadiazolyl dimers. In addition the obtained structure of ClCN2S2• represents the fifth polymorph of ClCN2S2• characterized by X‐ray crystallography. The structures and the packing including secondary interactions are discussed.
Structural Patterns and Dimensionality in Magnesium Borophosphates: The Crystal Structures of Mg2(H2O)[BP3O9(OH)4] and Mg(H2O)2[B2P2O8(OH)2]·H2O
Authors: Ewald Bastian , Öztan Yigit , Prots Yurii , Kniep Rüdiger 
Published: May 2005

AbstractHydrothermal investigations in the system MgO/B2O3/P2O5(/H2O) yielded two new magnesium borophosphates, Mg2(H2O)[BP3O9(OH)4] and Mg(H2O)2[B2P2O8(OH)2]·H2O. The crystal structures were solved by means of single crystal X‐ray diffraction. While the acentric crystal structure of Mg2(H2O)[BP3O9(OH)4] (orthorhombic, P212121 (No. 19), a = 709.44(5) pm, b = 859.70(4) pm, c = 1635.1(1) pm, V = 997.3(3) × 106 pm3, Z = 4) contains 1D infinite chains of magnesium coordination octahedra interconnected by a borophosphate tetramer, Mg(H2O)2[B2P2O8(OH)2]·H2O (monoclinic, P21/c (No. 14), a = 776.04(5) pm, b = 1464.26(9) pm, c = 824.10(4) pm, β = 90.25(1)°, V = 936.44(9) × 106 pm3,Z = 4) represents the first layered borophosphate with 63 net topology. The structures are discussed and classified in terms of structural systematics.
Crystal Structure of Cesium Dihydrotrifluoride, CsH2F3. Refinement of the Crystal Structures of NMe4HF2 and NMe4H2F3
Authors: Troyanov S. I. , Morozov I. V. , Kemnitz E. 
Published: May 2005

AbstractSingle crystals of (NMe4)(HF2) were obtained during attempted recrystallization of NMe4F from fluoroolefin. X‐ray diffraction data show that (NMe4)(HF2) crystallizes in the orthorhombic space group Pmmn with unit cell dimensions a = 6.535(2), b = 8.688(3), and c = 5.333(2) Å. The symmetric and virtually linear HF2 anions exhibit a short F···F distance of 2.256(2) Å. The both crystal structures of (NMe4)(H2F3) (orthorhombic, Pbca, a = 8.509(1), b = 11.273(2), and c = 14.880(2) Å) and CsH2F3 (orthorhombic, P212121, a = 7.345(3), b = 9.126(4), and c = 11.444(4) Å) contain dihydrogentrifluoride anions, H2F3−, which have a bent shape and F···F distances of 2.30‐2.34Å.
Nitridorhenium(V) Complexes with 1,3,4‐Triphenyl‐1,2,4‐triazol‐5‐ylidene
Authors: Braband H. , Neubacher S. , Grosskopf S. , Abram Ulrich 
Published: May 2005

Abstract[ReNCl2(PPh3)2] and [ReNCl2(PMe2Ph)3] react with the N‐heterocyclic carbene (NHC) 1,3,4‐triphenyl‐1,2,4‐triazol‐5‐ylidene (HLPh) under formation of the stable rhenium(V) nitrido complex [ReNCl(HLPh)(LPh)], which contains one of the two NHC ligands with an additional orthometallation. The rhenium atom in the product is five‐coordinate with a distorted square‐pyramidal coordination sphere. The position trans to the nitrido ligand is blocked by one phenyl ring of the monodentate HLPh ligand. The Re–C(carbene) bond lengths of 2.072(6) and 2.074(6) Å are comparably long and indicate mainly σ‐bonding between the NHC ligand and the electron deficient d2 metal atom.The chloro ligand in [ReNCl(HLPh)(LPh)] is labile and can be replaced by ligands such as pseudohalides or monoanionic thiolates such as diphenyldithiophosphinate (Ph2PS2−) or pyridine‐2‐thiolate (pyS−). X‐ray structure analyses of [ReN(CN)(HLPh)(LPh)] and [ReN(pyS)(HLPh)(LPh)] show that the bonding situation of the NHC ligands (Re–C(carbene) distances between 2.086(3) and 2.130(3) Å) in the product is not significantly influenced by the ligand exchange. The potentially bidentate pyS− ligand is solely coordinated via its thiolato functionality.Hydrogen atoms of each one of the phenyl rings come close to the unoccupied sixth coordination positions of the rhenium atoms in the solid state structures of all complexes. Re–H distances between 2.620 and 2.712Å do not allow to discuss bonding, but with respect to the strong trans labilising influence of “N3−”, weak interactions are indicated.
Crystal Structure of Rubidium Tetraiodothallate(III) Dihydrate, RbTlI4·2H2O
Authors: Rieger Franziska , Mudring Anja‐Verena 
Published: May 2005

AbstractThe crystal structure of RbTlI4·2H2O (cubic, ${\rm Fm}{\bar 3}\rm c$, Nr. 226, Z = 24, a = 1993.5(2) pm, 327 unique reflections with Io > 2σ(Io), R1 = 0.0305, wR2 = 0.0702, GooF = 1.1199, T = 298(2) K) is characterized by an ReO3 analogous arrangement of rubidium centered [TlI4] tetrahedra. The cuboctahedral cavities of this structure are filled with crystal water molecules and additional disordered rubidium cations.
Zum Chemischer Transport ternärer Übergangsmetall‐ und Erdalkaliwolframate MWO4 mit Chlor
Authors: Steiner Udo 
Published: May 2005

On the Chemical Vapor Transport of Ternary Transition Metal‐ and Earth Alkaline Tungstates MWO4 with ChlorineThe chemical vapor transport of transition metal tungstates MWO4 (M=Mn, Co, Ni, Cu, Zn, Cd) was investigated in dependence on mean transport temperature (923 K to 1223 K) and amount of transport agent Cl2. All tungstates migrate in a temperature gradient ΔT = 100 K from the region of higher temperature to the lower temperature with migration rates of 0.5 to 8 mg/h depending on experimental conditions. The transport behaviour was determined by continuous measurement of mass change during the transport experiments. The results were compared to thermo chemical calculations and the influence of moisture content discussed in detail. MgWO4 migrates under the influence of Cl2 in a temperature gradient 1273 K to 1173 K (migration rate 0.7 mg/h), CaWO4 and SrWO4 in a temperature gradient 1423 K to 1323 K (migration rate <0.1 mg/h).
γ‐HIO3 – a Metastable, Centrosymmetric Polymorph of Iodic Acid
Authors: Fischer Andreas , Lindsjö Martin 
Published: May 2005

AbstractFrom solutions of chromium(III) perchlorate and periodic acid, single crystals of γ‐HIO3 were obtained and characterized by single‐crystal X‐ray diffraction, Raman spectroscopy and thermal analysis. The compound crystallizes in the orthorhombic crystal system, space group Pbca (a = 563.92, b = 611.10, c = 1507.16 pm). The structure is built up by dimers (HIO3)2, which are formed by hydrogen bonds. The crystals are metastable and transform into the stable modification, α‐HIO3, within a couple of weeks.
Hyperacidity and hypergastrinemia following extensive intestinal resection
Authors: Meyers William C. , Jones R. Scott 
Published: May 2005

AbstractIncreased gastric acid secretion occurs after extensive intestinal resection in man, dog, rat, and monkey. Hypergastrinemia has been observed in patients with short gut syndrome and appears to accompany the hyperacidity after intestinal resection in dog, rat, and monkey. Postresectional hypergastrinemia is caused by increased release of gastrin and/or decreased degradation of the hormone. Other hormonal changes after extensive resection include increased insulin, GIP, pancreatic glucagon, and decreased enteroglucagon.
Clinical studies with gastric inhibitory polypeptide
Authors: Brown John C. , Otte Sue 
Published: May 2005

AbstractIntravenous infusion of porcine GIP in man induces insulin release when a degree of hyperglycemia is present. This glucose‐dependent insulinotropic response occurs when a dose of GIP is administered to obtain circulating levels of approximately 1 ng/ml, a physiologic level that can be achieved by the ingestion of glucose or corn oil or a mixed meal. Serum GIP was measured by radioimmunoassay, and the single antiserum used in all the described studies measures 2 immunoreactive forms of GIP.In patients with chronic pancreatitis receiving an oral glucose load or a mixed liquid test meal, GIP levels have been shown to be exaggerated. Similar elevated responses have been observed in obese patients and in maturity onset diabetes. A reduced GIP response has been seen in patients with celiac disease.A physiologic role for GIP in the enteroinsular axis has been established. However, involvement of the hormone in pathophysiologic situations is equivocal.
Resection of the pancreas for acute hemorrhagic and necrotizing pancreatitis
Authors: Autio Ville , Juusela Eero , Lauslahti Kalevi , Markkula Hannu , Pessi Teuvo 
Published: May 2005

AbstractThe role of surgery in the treatment of acute hemorrhagic or necrotizing pancreatitis is discussed on the basis of a series of 996 patients with all types of acute pancreatitis who were treated in the years 1967–1976. Pancreatic resection was performed in 29 patients with hemorrhagic or necrotizing pancreatitis during the past 3 years. The extent of resection ranged from 60 to 100% of the pancreas. Eight patients died, for a mortality rate of 28%. Eight of 21 surviving patients developed diabetes requiring substitution therapy. During a follow‐up period of 6 to 36 months, 17 patients were able to resume work, 3 are still convalescing, and 1 has retired.
Diagnosis and surgical treatment of “H‐Type” tracheoesophageal fistulas
Authors: Lam Conrad R. 
Published: May 2005

AbstractFour cases of H‐type tracheoesophageal fistula are reported. The patients all had chronic aspiration from the esophagus. Although serious symptoms were present in all, definitive diagnoses were not made until the patients had reached 1, 6, 12, and 50 years of age, because ordinary radiologic methods failed to establish the diagnosis. The angulation of the fistula usually prevents contrast medium in the esophagus from entering the trachea, especially with the subject upright. On the other hand, air easily passes from the trachea to the esophagus, eventually producing megaesophagus which may be confused with the picture of achalasia. An ill‐advised Heller esophagomyotomy was done on 1 patient. All 4 patients eventually had successful closure of the fistulas. Three operations were by the transthoracic route, and 1 high fistula in an infant was closed through a cervical approach.