bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transgenic rescue of GATA-1–deficient mice with GATA-1 lacking a FOG-1 association site phenocopies patients with X-linked thrombocytopenia
Authors: Shimizu Ritsuko , Ohneda Kinuko , Engel James Douglas , Trainor Cecelia D. , Yamamoto Masayuki 
Published: December 2003

Abstract
Association of GATA-1 and its cofactor Friend of GATA-1 (FOG-1) is essential for erythroid and megakaryocyte development. To assess functions of GATA-1–FOG-1 association during mouse development, we used the GATA-1 hematopoietic regulatory domain to generate transgenic mouse lines expressing a mutant GATA-1, which contains a substitution of glycine 205 for valine (V205G) that abrogates its association with FOG-1. We examined whether the transgenic expression of mutant GATA-1 rescues GATA-1 germ line mutants from embryonic lethality. In high-expressor lines we observed that the GATA-1V205G rescues GATA-1–deficient mice from embryonic lethality at the expected frequency, revealing that excess GATA-1V205G can eliminate the lethal anemia that is due to GATA-1 deficiency. In contrast, transgene expression comparable to the endogenous GATA-1 level resulted in much lower frequency of rescue, indicating that the GATA-1–FOG-1 association is critical for normal embryonic hematopoiesis. Rescued mice in these analyses exhibit thrombocytopenia and display dysregulated proliferation and impaired cytoplasmic maturation of megakaryocytes. Although anemia is not observed under steady-state conditions, stress erythropoiesis is attenuated in the rescued mice. Our findings reveal an indispensable role for the association of GATA-1 and FOG-1 during late-stage megakaryopoiesis and provide a unique model for X-linked thrombocytopenia with inherited GATA-1 mutation.
Hemochromatosis mutations in the general population: iron overload progression rate
Authors: Andersen Rolf Værn , Tybjærg-Hansen Anne , Appleyard Merete , Birgens Henrik , Nordestgaard Børge Grønne 
Published: December 2003

Abstract
The progression rate of iron overload in hereditary hemochromatosis in individuals in the general population is unknown. We therefore examined in the general population iron overload progression rate in C282Y homozygotes. Using a cohort study of the Danish general population, The Copenhagen City Heart Study, we genotyped 9174 individuals. The 23 C282Y homozygotes identified were matched to 2 subjects each of 5 other HFE genotypes with respect to sex, age, and alcohol consumption. As a function of biologic age, transferrin saturation increased from 50% to 70% from 25 to 85 years of age and from 70% to 80% from 35 to 80 years of age in female and male C282Y homozygotes, respectively. Equivalently, ferritin levels increased from 100 to 500 μg/L and decreased from 800 to 400 μg/L in female and male C282Y homozygotes. As a function of 25 years follow-up irrespective of age, transferrin saturation and ferritin levels increased slightly in male and female C282Y homozygotes. None of the C282Y homozygotes developed clinically overt hemochromatosis. In conclusion, individuals in the general population with C282Y homozygosity at most demonstrate modest increases in transferrin saturation and ferritin levels, and clinically overt hemochromatosis is rare. Therefore, C282Y homozygotes identified during population screening, and not because of clinically overt hemochromatosis, at most need to be screened for manifestations of hemochromatosis every 10 to 20 years. (Blood. 2004;103: 2914-2919)
Isolation and Reaction of (Indolin-3-ylidene)pentacarbonyltungsten Generated from Tungsten-containing Azomethine Ylide
Authors: Takaya Jun , Kusama Hiroyuki , Iwasawa Nobuharu 
Published: December 2003

Abstract
(Indolin-3-ylidene)pentacarbonyltungsten, a non-heteroatom-stabilized carbene complex of group 6 metal, was successfully isolated by the reaction of N-(o-alkynylphenyl)imine derivative, vinyl ether and tungstenhexacarbonyl under photoirradiation. This complex was moderately stable and fully characterized by spectroscopic analysis.
2-Hydroxyphenyl-1,3-dimethylbenzimidazolines. Formal Two Hydrogen Atom-donors for Photoinduced Electron Transfer Reactions
Authors: Hasegawa Eietsu , Chiba Naoki , Takahashi Tomoya , Takizawa Shinya , Kitayama Takashi , Suzuki Toshio 
Published: December 2003

Abstract
Both 2-(2′-hydroxyphenyl)-1,3-dimethylbenzimidazoline and 2-(4′-hydroxyphenyl)-1,3-dimethylbenzimidazoline were found to act as formal two hydrogen atom-donors for photoinduced electron transfer reactions of epoxy ketones and other carbonyl compounds.
Synthesis of Mesoporous Ce-doped TiO2 with High Thermal Stability
Authors: Wang Chao , Xi Hong-an , Wang Ruo-Ding 
Published: December 2003

Abstract
Mesoporous Ce-doped TiO2 with a high thermal stability was prepared by using inexpensive glycerin as a pore former via sol-gel and hydrothermal processes. The product has a high specific surface area (129.7 m2/g) and a pore volume (0.41 cm3/g) even after calcination at 600 °C for 2 h.
Synthesizing Hyperbranched Azo Polymer through Azo-coupling Reaction
Authors: Che Pengchao , He Yaning , Zhang Yue , Wang Xiaogong 
Published: December 2003

Abstract
An AB2 monomer N,N-bis[2-(4-aminobenzoyloxy)ethyl]aniline was synthesized by nucleophilic substitution reaction between N,N-bis(2-chloroethyl)aniline and 4-aminobenzonic acid. Based on the monomer, the azo-coupling reaction was explored for the first time to prepare a hyperbranched azo polymer. The results showed that the scheme was a feasible way to synthesize hyperbranched azo polymers under extremely mild conditions.
Optical rotation in RbTiOAsO4(point groupmm2)
Authors: Kaminsky W. , Thomas P. A. , Glazer A. M. 
Published: December 2003

AbstractMeasurement of optical rotation in RbTiOAsO4(RTA) with the tilter method resulted in an optical rotation ofρ12= +17(3)o/mm at a wavelength of 670nm, when a (100) sample was tilted about [001]. A tilt about [010] showed no rotation, as expected from the directional dependence of optical rotation calculated from the tensor in point groupmm2. The absolute Miller-indices of the sam-les were found using X-ray anomalous scattering. The calculations with a dipole-dipole model show that the As5+-ions in RTA correlate with the main structural contribution of the optical rotation. However, there seems to be an even larger intrinsic contribution due to the Ti4+– ions as a result of the distorted octahedral co-ordination with oxygen.
X-ray crystal structure analysis of lanthanide trihydrogeno hydroxy-1-ethanebis(phosphonate)-1,1,dihydrogeno hydroxy-1ethanebis(phosphonate)-1,1 hemiundecahydrate, Ln{[C(CH3)(OH)(P2O6H3)][C(CH3)(OH)(P2O6H2)]}⋅5.5H2O with Ln = Y, Ho, Er; and energy parametrization of the absorption spectrum of the Er compound
Authors: Van Meervelt L. , Martello P. , Silvestre J.-P. , Rochdaoui R. , Lee M.-R. , Quy Dao N. , Görller-Walrand C. 
Published: December 2003

Abstract
The crystal structures of Ln{[C(CH3)⋅(OH)(P2O6H3)][C(CH3)(OH)(P2O6H2)]}⋅5.5H2O, with Ln = Y (compound 1), Ln = Ho (compound 2) and Ln = Er (compound 3), have been determined by single crystal X-ray diffraction. The three compounds are isomorphous and crystallize in the monoclinic space group P21/n (n°14). The cell parameters of 1 are a = 10.451(2) Å, b = 11.395(3) Å, c = 17.173(3) Å, β = 94.28(1)°, those of 2 are a = 10.447(2) Å, b = 11.382(2) Å, c = 17.129(4) Å, β = 94.32(3)°, and those of 3 are a = 10.432(1) Å, b = 11.398(2) Å, c = 17.134(2) Å, β = 94.35(2)°.The coordination polyhedron around the lanthanide cations is a distorted monocapped trigonal prism with a slightly distorted C
2

v
symmetry. The UV and visible light absorption spectrum was recorded for 3. A detailed theoretical simulation of the energy level scheme of the 4f11 configuration of Er3+ was carried out. The angular parts were accurately calculated by group-theoretical and tensorial methods and the radial integrals were left as parameters to be determined semi-empirically. The C
2

v
symmetry was described by free ion and crystal field parameters after refinement of these parameters on the absorption spectroscopic data of 3.
The crystal structure of the decomposition product NH4HC2O4 from powder diffraction data
Authors: Audebrand N. , Louër D. 
Published: December 2003

Abstract
The crystal structure of anhydrous ammonium acid oxalate, NH4HC2O4, obtained from the thermal decomposition of the related hemihydrate has been determined from powder diffraction data collected with monochromatic laboratory X-rays, using the capillary technique. The crystal structure is monoclinic, P21/c, Z = 4, a = 4.3629(1) Å, b = 13.5657(1) Å, c = 7.7100(1) Å, β = 102.602(1)° and V = 445.3(1) Å3. The structure has been solved with the direct methods and refined with the Rietveld method, from which the agreement factors R
wp = 8.19% and R
B = 5.18% have been obtained. The crystal structure consists of corrugated layers built from seven-fold ammonium coordination polyhedra and connected by oxalate groups. The hydrogen atom positions have been located and the hydrogen bond network is extensively discussed.
Nitridocompounds of manganese: manganese nitrides and nitridomanganates
Authors: Niewa R. 
Published: December 2003

AbstractThe chemistry of nitrides and nitridometalates is a rapidly growing field in solid state chemistry. This short review is intended to give a brief but comprehensive over-view on the compounds and phases formed with manga-nese, which cover an especially broad range of oxidation states. Furthermore, the present paper tries to put the ob-served structures and properties of the compounds into a broader context.
Analysis of short and long range atomic order in nanocrystalline diamonds with application of powder diffractometry
Authors: Palosz B. , Grzanka E. , Gierlotka S. , Stel´makh S. , Pielaszek R. , Bismayer U. , Neuefeind J. , Weber H.-P. , Proffen Th. , Von Dreele R. , Palosz W. 
Published: December 2003

Abstract
Fundamental limitations, with respect to nanocrystalline materials, of the traditional elaboration of powder diffraction data like the Rietveld method are discussed. A tentative method of the analysis of powder diffraction patterns of nanocrystals based on the examination of the variation of lattice parameters calculated from individual Bragg lines (named the “apparent lattice parameter”, alp) is introduced. We examine the application of our methodology using theoretical diffraction patterns computed for models of nanocrystals with a perfect crystal lattice and for grains with a two-phase, core-shell structure. We use the method for the analysis of X-ray and neutron experimental diffraction data of nanocrystalline diamond powders of 4, 6 and 12 nm in diameter. The effects of an internal pressure and strain at the grain surface are discussed. The results are based on the dependence of the alp values on the diffraction vector Q and on the PDF analysis. It is shown, that the experimental results lend a strong support to the concept of a two-phase structure of nanocrystalline diamond.
The crystal structure of non-stoichiometric monoclinic Cr5+

x
S8 (x = 0.20 and 0.26) prepared under high pressure and high temperature
Authors: Bensch W. , Lühmann H. , Näther C. , Huppertz H. 
Published: December 2003

Abstract
Two non-stoichiometric chromium rich Cr5+

x
S8 (x = 0.20 and 0.26) samples were prepared under high pressure and high temperature conditions. In the crystal structures three different metal atom sites are fully and the fourth site is only partially occupied. The results of single crystal and Rietveld refinements are in good agreement. The CrS6 octahedra share common corners and common faces. Across common faces extraordinary short Cr—Cr distances are observed suggesting metal-to-metal bonding. On the basis of the distortion of the CrS6 octahedra Cr4+ is located on two of the four Cr sites. With increasing Cr content the amount of Cr4+ is lowered and the distortion of two of the four CrS6 octahedra is significantly reduced.
Study of effect of thermal annealing on crystalline perfection of bismuth germanate single crystals grown by low thermal gradient Czochralski method
Authors: Choubey A. , Bhagavannarayana G. , Shubin Yu. V. , Chakraborty B. R. , Lal K. 
Published: December 2003

Abstract
Bismuth germanate single crystals containing low angle and very low angle boundaries were selected as specimen for annealing experiments at 1000 °C for varying lengths of time in the range: 8 h to 80 h. Specimen with larger surface along (111) and (100) planes were investigated. The tilt angles of the boundaries were found to be in the range: 16 arc sec to 88 arc sec. Half widths of the diffraction curves of different subgrains were in the range: 15 arc sec to 39 arc sec. High resolution X-ray diffractometry and topography were employed for structural characterization and secondary ion mass spectrometry (SIMS) was used for study of impurity distribution. Annealing led to significant improvement in the crystalline perfection of specimen and all but one of the boundaries could be removed. The very low angle boundaries, which could not be annealed out, had a tilt angle of 41 arc sec. The half widths of diffraction curves of the two remaining subgrains were: 10 arc sec and 17 arc sec. The growth of subgrains as a result of annealing was investigated. SIMS investigation of annealed specimen, in which a very low angle boundary persisted, showed the boundary was decorated with silicon impurity, which presumably acted as a pining center. Detailed diffractometric and topographic experiments helped in delineating the two subgrains around the very low angle boundary. The morphological features of the very low angle boundary were studied in detail.
The high-pressure behaviour of 3R-NbS2
Authors: Ehm L. , Knorr K. , Depmeier W. 
Published: December 2003

Abstract
The high pressure behaviour of 3R-NbS2 has been investigated by angle-dispersive X-ray powder diffraction using diamond anvil cells up to 14 GPa. The compression behaviour of the structure is highly anisotropic. The compressibility perpendicular to the layers is 2.5 times higher than within the layers. A fit of a 3
rd
-order Birch-Murnaghan equation of state gave a volume at zero pressure V
0=174(1) Å3 and a bulk modulus b
0=57(1) GPa, with a pressure derivative b'=8.6(5).
Crystal structure analysis and extremely long-living light-induced metastable states in RbY[Fe(CN)5NO]2·10H2O and CsY[Fe(CN)5NO]2·10H2O
Authors: Woike Th. , Held P. , Mühlberg M. , Imlau M. 
Published: December 2003

Abstract
Crystal structures of both isostructural com-pounds were solved from single crystal X-ray diffraction data (space group P21/n; Z = 4; Rb-compound: a = 9.812(1) Å, b = 25.793(3) Å, c = 11.777(2) Å, β = 104.68(1)°, R
gt(F) = 0.0458, wR
ref(F
2) = 0.0918; Cs-compound: a = 9.9058(8) Å, b = 25.919(2) Å, c = 11.883(1) Å,β = 105.542(7)o, Rgt(F) = 0.0450,wRref(F2) = 0.0951. The main structural feature is the nitrosylpentacyanoferrate(II)-complex [Fe(CN)5NO]2–. The iron atoms are coordinated to five cyanide and one nitrosyl ligand. The coordination polyhedron of the Y3+ cation is a distorted tetragonal antiprism built up from three nitrogen atoms of three complexes and five water molecules. Both rubidium and cesium ions are surrounded by seven cyanide groups of five complexes and one water molecule to form a distorted bicapped trigonal prism. One metastable state (SI) can be excited by irradiation with light in the spectral range of 400–500 nm at temperatures below 180 K. The radiationless thermal decay is detected by Differential Scanning Calorimetry by heating above T = 180 K. Evaluating the exothermal heat flow using the Arrhenius law yields an activation energy of EA
= 0.64(2) eV and a frequency factor of Z = 20(8)·1012s–1 for the rubidium compound and EA
= 0.56(2) eV, Z = 30(8)·1010s–1 for the cesium compound. The contribution of the cations on the decay temperature of the metastable states is discussed on the basis of the atomic distances and coordinations.
Structural investigation of the phase transitions of [N(CH3)4]2HgCl4
Authors: Amami M. , van Smaalen S. , Palatinus L. , Ben Salah A. , Helluy X. , Sebald A. 
Published: December 2003

Abstract
The crystal structures of [N(CH3)4]2HgCl4 between 191 K and 350 K have been studied by single crystal X-ray diffraction. Below Tc

1 = 277 K the structure is monoclinic P21/a with lattice parameters a = 12.320 (7), b = 9.034 (4), c = 15.402 (4) Å, and β = 89.64 (1)° at T = 191 K. Above Tc

1 the structure is orthorhombic Pnma with lattice parameters 12.419 (7), b = 9.068 (4), and c = 15.684 (2) Å at room temperature, and with lattice parameters a = 12.421 (9), b = 9.125 (1), and c = 15.777(4) Å at T = 350 K. At room temperature each TMA cation disorderly occupies two orientations (TMA is tetramethylammonium). At low temperature the structure is fully ordered, with additional shifts and rotations of all ions, in accordance with the results of Asahi et al., J. Phys. Soc. Jpn. 60 (1991) 921. Refinements using restrictions of the non-crystallographic tetrahedral point group for the TMA cations and refinements without restrictions are used to show that TMA has tetrahedral symmetry at all temperatures. The HgCl4 anions are distorted, but the distortions are independent of the temperature. The phase transition at Tc

1 is described as an order/disorder transition accompanied by major rotations and shifts of the ions. New evidence for a previously reported phase transition at Tc

2 = 320 K (Zangar et al. Phase Transitions 12 (1988) 141) is obtained from NMR. This transition is shown to be a non symmetry breaking structural transition, that correspond to a gradual loss of the orientational order of the TMA cations.
Phase transitions in solid solution series bismutocolumbite – stibiocolumbite (Bi-Sb)(Nb0.79Ta0.21)O4
Authors: Kazantsev S. S. , Pushcharovsky D. Yu. , Maximov B. , Molchanov V. , Werner S. , Schneider J. , Sapozhnikov A. N. 
Published: December 2003

Abstract
The crystal structure of bismutocolumbite, Bi(Nb0.79Ta0.21)O4 with orthorhombic (sp. gr. Pnna) stibio-tantalite structure type at ambient conditions has been de-termined at 2.59 and 9.56 GPa, and 23oC. Crystal data and results of structure refinement using powder X-ray diffrac-tion and Rietveld analysis for Bi-rich stibiocolumbite, (Sb0.52Bi0.48)(Nb0.71Ta0.29)O4, are reported. At the pressure ~2.9 GPa bismutocolumbite exhibits phase transition which is accompanied by the change of its symmetry: sp. gr. Pnna is replaced by the sp. gr. Pn21
a. This kind of transformation is anticipated at ambient pressure in bismutocolumbite- stibiocolumbite solid solution series in the compounds with Sb/(Bi+Sb) ratio higher than 0.52 which characterises the studied crystals of stibiotantalite. Similarly with scheelite-like BiVO4, in bismutocolumbite the reduction of the unit cell volume under HP is mainly a result of Bi-O polyhedral compression, which is accompanied by a rearrangement of (Nb,Ta)O6 octahedra within octahedral sheets parallel to (010). (Nb,Ta)O6 octahedra remain rigid with smaller change in size at high pressure.
A reinvestigation of Wilm's salt, (NH4)4[RhCl6]NO3 -structure, spectroscopy and thermal analysis-
Authors: Reiß G. J. 
Published: December 2003

Abstract
The redetermination of the crystal structure of Wilm's salt, tetraammonium hexachlororhodate(III) nitrate, (NH4)4[RhCl6]NO3 from single crystal data, necessitated a change in space group symmetry description, as a conse-quence of comparative structure refinements, from the polar space group R3m to the chiral space group R32 for the room temperature structure. In contrast to the former structure determination it is shown, that in the correct space group a structure model can be derived, in which all parts of the structure – including the H atom positions of the ammonium ions – appear completely ordered on their sites. The ammonium cations and the hexachlororhodate as well as the nitrate anions form a three-dimensional framework via weak N-H···Cl and N-H···O hydrogen bonds. Reproducing the original synthesis conditions and analysing the products by powder diffraction methods, the by-products have been identified as ammonium nitrate and diammonium aquapentachlororhodate(III). Doing DTA experiments on the title compound, two endothermic effects at 54°C and 128°C have been detected that may be related to phase transitions from the ordered room temperature structure to disordered high temperature sub structures. According to the results of thermo gravimetry the title compound decomposes at temperatures above 140°C. The temperature dependant IR spectroscopy in the range of RT-60 C it is probable that the above mentioned thermal effect at 54°C is associated with an order disorder phase transition introduced by the ammonium cations. The UV/Vis spectroscopy show that at 8 K a significant distortion of the [RhCl6]3–octahedron from highest 32 point symmetry is plausible.
Structural and chemical variations in rathite, Pb8Pb4—x(Tl2As2)x(Ag2As2)As16S40: modulations of a parent structure
Authors: Berlepsch P. , Armbruster Th. , Topa D. 
Published: December 2003

AbstractMembers of the 4,4 sartorite homologues can be deduced from a topological parent structure with orthorhombic symmetry, space groupPmnb,a= 4.233,b= 7.918,c= 24.692 Å. The observed modulations in 4,4 sartorite homologues are associated with symmetry lowering of the parent structure and superstructure formation. The Pb, Tl, Ag, As, Sb sulfosalt rathite is a 4,4 member of the sartorite homologous series with space group symmetryP21/cand is isostructural to synthetic Ba12Sb18.64S40and closely related to Ba10.48Pb5.52Sb16S40of reduced symmetryP21. In these structures the two-fold screw axes run parallel tobof the parent structure. Isotopological is also dufrénoysite Pb16As16S40, another 4,4 homologue of the same series, of space group symmetryP21. In dufrénoysite, however, the two-fold screw axes run parallel tocof the parent structure. To elucidate the modulation of the parent structure, rathite has been structurally and chemically reinvestigated emphasising cation order/disorder relations. Single crystal X-ray structure refinement (space groupP21/c;a= 8.496(1),b= 7.969(1),c= 25.122(3) Å,β= 100.704(2)°;R1= 3.67% for 2718 reflections withI> 2σ[I]) yielded three split cation positions indicating heterovalent substitutions. Considering that isoelectronic Pb2+and Tl+cannot be distinguished in our diffraction experiment the chemical composition (Pb9.25Tl1.37)Σ=10.62Ag2.01(As19.09Sb0.83)Σ=19.92S40derived from electron microprobe analyses matches the formula Pb10.96Ag1.90(As18.09Sb1.06)Σ=19.15S40obtained from the structure refinement. The complex composition is caused by two independent heterovalent substitutions Ag++ As3+→ 2 Pb2+and Tl++ As3+→ 2 Pb2+leading to the simplified rathite formula Pb8Pb4–x(Tl2As2)x(Ag2As2)As16S40. The substitution involving Ag seems to be essential for the formation of rathite and distinguishes rathite from dufrénoysite Pb16As16S40. The Tl substitution in rathite appears to be optional. In addition, minor Sb3+may replace As3+.
Die Packungsdichte der Atome in Modifikationen von Kohlenstoff und Silicium
Authors: Trömel Martin , Hübner Sven 
Published: December 2003

AbstractThe crystal chemistry of carbon and silicon is discussed with respect to the packing density of atoms in their crystalline modifications. The reduced atomic volumes of metallic carbon as calculated from diamond, hexagonal diamond and buckminsterfullerene C60agree within less than 0.2, indicating the correctness of the reducing procedure. A much lower value calculated from graphite, rhombohedral graphite and a low-temperature modification of buckminsterfullerene remains unexplained. Two proposed crystal structures of a cubic body-centered form of carbon appear unacceptable. The reduced atomic volumes of diamond-type silicon and metastableγ-Si are in good agreement. Their values, calculated from six allotropic modifications (Si I, II, XI, V, VI, VII, and Si X) at pressures up to ≈200 GPa, are represented by an empirical exponential function of pressure. From this function, an isothermal equation of state is derived including the packing density of the atoms.