bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Stannides AuNiSn2 and AuCuSn2 – Bulk Synthesis and Superstructure Determination
Authors: Lange Stefan , Nilges Tom , Hoffmann Rolf‐Dieter , Pöttgen Rainer 
Published: May 2006

AbstractThe stannides AuNiSn2 and AuCuSn2 were prepared by melting of the elements in silica ampoules at 1300 K followed by slow cooling to room temperature. The structures of both compounds were refined on the basis of single crystal X‐ray data: $P{\bar 3}m{\rm 1}$, a = 412.41(14), c = 529.24(11) pm, wR2 = 0.0268, 159 F2 values, 10 variables for AuNiSn2 and a = 425.97(17), c = 526.88(15) pm, wR2 = 0.0507, 159 F2 values, 11 variables for AuCuSn2 (twinned crystal, BASF = 0.305(4)). These stannides crystallize with a superstructure of the NiAs type with a complete ordering of the transition metal atoms. They derive from a AuSn subcell structure, where every other layer of octahedral voids in the hexagonal closest packing of the tin atoms is filled by nickel in AuNiSn2 and by copper in AuCuSn2. Due to the symmetry reduction smaller NiSn6/6 (CuSn6/6) and larger AuSn6/6 octahedra alternate along the c axis. The crystal chemistry is discussed on the basis of a group‐subgroup scheme.
Condensation of Rare Earth Pyrazolates: The Dimeric, Trimeric and Polymeric Units [Gd2(Pz)6(PzH)4], [Nd3(Pz)9(PzH)2] and $^{1}_{\infty}\rm [Eu(Pz)_{2}(PzH)_{2}]$
Authors: Quitmann Catharina C. , Bezugly Victor , Wagner Frank R. , Müller‐Buschbaum Klaus 
Published: May 2006

AbstractSolvent free high‐temperature oxidations of rare earth metals with the heterocycle pyrazole as well as in low to non‐coordinating solvents were investigated to isolate intermediate stages between monomeric and polymeric pyrazolates of the lanthanides. Reaction conditions were tuned according to simultaneous DTA/TG and temperature dependent X‐ray powder diffraction experiments on known monomeric and polymeric pyrazolates, that gave rise to the idea that further structure intermediates could be isolated. Reactions in 1,2,3,4‐tetrahydroquinoline gave the dimeric complex [Gd2(Pz)6(PzH)4](PzH)(Tech) (1) as well as the triangular complex [Nd3(Pz)9(PzH)2](PzH)(Tech)2 (2). The solvent free melt synthesis resulted in a new polymeric form of $^{1}_{\infty}\rm [Eu(Pz)_{2}(PzH)_{2}]$ (3) (pyrazole, PzH = C3H3NNH; pyrazolate anion, Pz− = C3H3NN−; 1,2,3,4‐tetrahydroquinoline, Tech = C9H13N). All three compounds contain coordinating pyrazolate amide groups and pyrazole molecules the latter decreasing in numbers upon condensation of the building units. According to simultaneous DTA/TG/MS investigations the condensation process can be identified with the release of pyrazole molecules.1 consists of dimeric molecules containing trivalent gadolinium with a C.N. of eight. The two gadolinium atoms show different coordination polyhedra. Only σ coordination and bridging is found for 1. 2 consists of trimeric molecules containing trivalent neodymium. The neodymium atoms also exhibit different coordination polyhedra with C.N.s of eight and nine. Both π and σ coordination is found for 2, the π coordinating pyrazolate ligands acting as lids of the triangular units. Topological analysis of the electron localization function (ELF) for 2 calculated at the scalar‐relativistic DFT level reveals only weakly covalent π donor η5‐Pz–Nd interactions compared to the stronger covalent σ donor Pz–Nd interactions. The topological analysis of both, the ELF and the electron density reveals no significant differences of the respective charges of the Nd atoms. 3 exhibits a one‐dimensional chain structure with EuII and a C.N of ten. It can thus be addressed the β form of the referring formula with a new arrangement of the coordinating ligands. Like the α form 3 shows σ and π coordination of pyrazole and pyrazolate ligands. Simultaneous DTA/TG analysis reveals that the low‐temperature α form shows a phase transition into the β form between 110 °C and 130 °C. The three compounds were investigated by low‐temperature single crystal X‐ray analysis, Mid IR and Far IR spectroscopy.
The Simultaneous Oxidation of Tellurium and Transition Metals by AsF5 – Syntheses and Crystal Structures of [M(SO2)6](Te6)[AsF6]6 (M = Ni, Zn) and [Cd(SO2)2][AsF6]2
Authors: Beck Johannes , Steden Folker , Zink Marcus 
Published: May 2006

AbstractThe reactions of elemental nickel and tellurium and of ZnTe with excess AsF5 in liquid SO2 yield [M(SO2)6](Te6)[AsF6]6 (M = Ni, Zn) as orange crystals. The crystal structure determinations (triclinic, $P{\bar 1}$, M = Ni: a = 1632.59(2), b = 1795.06(1), c = 1822.97(2) pm, α = 119.11(4), β = 90.78(4), γ = 106.28(4)°, V = 4408.24(8)·106pm3, Z = 4) show the two compounds to be isotypic. The structures are made up of discrete [M(SO2)6]2+ complexes, Te64+ clusters and octahedral [AsF6]− ions. In the [M(SO2)6]2+ complexes the metal ions are surrounded octahedrally by six SO2 molecules bound via the O atoms. The Te64+ polycations are of trigonal prismatic shape with short Te–Te bonds within the triangular faces (270 pm) and long Te–Te bonds along the edges parallel to the pseudo C3 axes of the prisms (312 pm). The arrangement of the ions is related to the Li3Bi structure type. [M(SO2)6]2+ complexes and Te64+ polycations together form a distorted cubic closest packing with all tetrahedral and octahedral interstices filled by [AsF6]− ions. The analogous reaction starting from CdTe did not yield a compound containing simultaneously [Cd(SO2)n]2+ complexes and tellurium polycations but instead Te6[AsF6]4 · 2 SO2 besides [Cd(SO2)2][AsF6]2 were obtained. It crystallizes isotypically to [Mn(SO2)2][AsF6]2 (Mews, Zemva, 2001) (orthorhombic, Fdd2, a = 1534.96(3), b = 1812.89(3), c = 892.28(3) pm, V = 2483·106 pm3, Z = 4).
The Structural Systematics of Protonation of Some Important Nitrogen‐base Ligands. I Some Univalent Anion Salts of Doubly Protonated 2, 2′:6′, 2″‐Terpyridyl
Authors: Junk Peter C. , Kepert Cameron J. , Semenova Lioubov I. , Skelton Brian W. , White Allan H. 
Published: May 2006

AbstractA number of salts of 2,2′:6′,2″ ‐terpyridyl (‘tpy’) with univalent anions (halides : X = Cl, Br, I; oxyanions of increasing basicity: ClO4, NO3, ‘tfa’ = trifluoroacetate, ‘tca’ = trichloroacetate), variously solvated, have been structurally characterized by single crystal X‐ray studies. In all cases the tpy moieties are found to be doubly protonated [tpyH2]2+, the hydrogen atoms being associated with the nitrogen atoms of the peripheral rings, these together with the central nitrogen atom being directed towards a common focus, in most cases ‘chelating’ one of the counter‐ion components in diverse ways. Thus the chloride and bromide compounds are isomorphous [(tpyH2)X]+X−·H2O arrays; a second dihydrate phase is also described for the chloride, the two forms having the unchelated anion and water molecules engaged in hydrogen‐bonded networks essentially independent of [(tpyH2)X]+. The iodide is anhydrous, and of a different structural type, the anions, presumably too large for chelation, lying out of plane to either side, and linking different cations into a one‐dimensional polymer; in the perchlorate, the unsolvated aggregate is now discrete [(tpyH2)X2], a pair of perchlorate ions disposed to either side of the tpy plane, lying each with one oxygen atom interacting with both of the two protonating hydrogen atoms. In the anhydrous X = NO3, tfa, tca arrays, the lattices are solvated by the parent acids; one oxygen atom of each anion is chelated by the [tpyH2]2+ as in the chlorides, the other anion, with the acid, forming an independent ‘acid salt’ counterion [XHX]− in each case, retaining the additional protonic hydrogen rather than further protonating the central ring, all being of the form [(tpyH2)X]X·HX = [(tpyH2)X][X(HX)].
The Structural Systematics of Protonation of Some Important Nitrogen‐base Ligands. II. Some Univalent Anion Salts of Singly Protonated Bis(2‐pyridyl)amine
Authors: Junk Peter C. , Wei‐Min Lu , Semenova Lioubov I. , Skelton Brian W. , White Allan H. 
Published: May 2006

AbstractSyntheses and single crystal X‐ray structure determinations are recorded for a number of normal and ‘acid’ salts of bis(2‐pyridylamine), ‘dpa’, with univalent anions, X, variously hydrated, i.e. [dpaH]X·nH2O, and [dpaH]X·HX·nH2O. The ‘normal’ salt arrays so characterized are for X = Br− (n = 2, isomorphous with the previously described chloride compound) and, I−, ClO4−, ‘tca−’ (≡ Cl3CCO2)− (all n = 1); acid salt arrays are described for X = NO3− and tca (both n = 0). In all cases except those of X = ClO4−, NO3−, there is one independent formula unit devoid of crystallographic symmetry comprising the asymmetric unit of the structure. In all cases, the proton associated with the cation is ‘chelated’ by the pair of ring nitrogen atoms, disposed ‘endo’; in the tca adducts and the nitrate salt, the total cation is disordered in each case by inversion about a real or putative inversion centre between the rings. In the perchlorate compound, the (ordered) cation lies on a crystallographic 2‐axis, as does the water molecule, and the perchlorate ion, which is disordered about such an axis; in the nitrate compound, the acid hydrogen atom is modelled as disposed on a crystallographic inversion centre between a pair of symmetry‐related nitrate groups, containing, like the Htca adduct, the [XHX]− moiety rather than a diprotonated cation.
The Iron Hydrido Complex [FeH(dppe)2]+: Solution and Solid‐State Reactivity with Dinitrogen
Authors: Franke Oliver , Wiesler Beatrix E. , Lehnert Nicolai , Peters Gerhard , Burger Peter , Tuczek Felix 
Published: May 2006

AbstractThe blue compound [FeH(dppe)2]BPh4 (1) (dppe = 1,2‐bis(diphenylphosphino)ethane) is investigated by optical absorption, vibrational, NMR and Mössbauer spectroscopy as well as magnetic susceptibility measurements. In the solid state, 1 is found to be paramagnetic (S=1) whereas in tetrahydrofuran (thf) solution it is diamagnetic. Importantly, 1 reacts with dinitrogen in thf solution and in the solid state to give the yellow and green dinitrogen complexes 2a and 2b, respectively, both of which have the formula [FeH(N2)(dppe)2]BPh4. Apart from their colour and optical spectroscopic properties, the dinitrogen compounds 2a and 2b also differ in their magnetic, Mössbauer and vibrational properties. The N‐N stretching frequency of 2a is found at 2120 cm−1 whereas 2b exhibits an N‐N stretching vibration of 2145 cm−1. Moreover, 2a is diamagnetic whereas 2b is paramagnetic. DFT is employed to determine the relative energies and structure of 1 and its dinitrogen adducts in the singlet and triplet state.
Structure and Properties of GdAuSn and the GdAuSn/MnAuSn System
Authors: Casper Frederick , Ksenofontov Vadim , Kandpal Hem Chandra , Reiman Sergey , Shishido Toetsu , Takahashi Masashi , Takeda Masuo , Felser Claudia 
Published: May 2006

AbstractThe crystal structure of GdAuSn was refined by means of single crystal X‐ray diffraction. Band structure calculations based on the structural data confirmed the antiferromagnetic ground state and the metallic behaviour of GdAuSn. 119mSn, 155Gd and 197Au Mössbauer spectroscopic studies were used to verify the values of the hyperfine parameters that were given by the band structure calculations. Band structure calculations of MnAuSn confirmed that this half‐Heusler compound belongs to the family of half‐metallic ferromagnets. Magnetic susceptibility, conductivity and Mössbauer studies were used to characterize granular material based on the half‐Heusler ferromagnet MnAuSn in the antiferromagnetic GdAuSn matrix. Magnetoresistance measurements of the granular systems revealed an enormously high positive effect at temperatures below the antiferromagnetic ordering in GdAuSn.
Chemischer Transport ternärer Oxide in den Systemen Ca/Mo/O und Sr/Mo/O
Authors: Steiner Udo , Reichelt Werner 
Published: May 2006

AbstractChemical Vapour Transport of Ternary Oxides in the Systems Ca/Mo/O and Sr/Mo/OThe chemical vapour transport behaviour of ternary phases in the Ca/Mo/O and Sr/Mo/O systems has been investigated using Cl2 as transport agent in a temperature gradient 1423 to 1323 K. MMoO4 (M= Ca, Sr) migrate in the above‐mentioned temperature gradient with rates of 0.1 to 0.2 mg/h. Starting from three phase mixtures crystals of the compounds MMo5O8 have been grown (migration rates: M = Ca 0.1 mg/h, M = Sr 0.01 mg/h). The observed transport behaviour is compared with predictions given by thermo dynamical model calculations and the influences of source composition and the moisture contents are described in detail.
The early road to material requirements planning
Authors: Mabert Vincent A. 
Published: May 2006

AbstractMaterial requirements planning (MRP) systems became a prominent approach to managing the flow of raw material and components on the factory floor in the late 20th century. Its adoption was not an over night phenomenon, but was a slow progression over many decades. This article chronicles many developments and events during the formative years of MRP, highlighting changes in computer technology and contributions by key early proponents of this approach for managing the flow of material on the factory floor.
Parathyroid Hormone: A Sensitive Predictor of Hypocalcemia Following Total Thyroidectomy
Authors: Khafif Avi , Pivoarov Arie , Medina Jesus E. , Avergel Avraham , Gil Ziv , Fliss Dan M. 
Published: May 2006

OBJECTIVETo investigate whether monitoring parathyroid hormone (PTH) could predict hypocalcemia following total thyroidectomy or other bilateral thyroid manipulations.STUDY DESIGN AND SETTINGForty patients undergoing total thyroidectomy as well as other bilateral thyroid procedures were prospectively enrolled. PTH levels were measured preoperatively and 30 minutes postoperatively. Calcium levels were measured preoperatively and every 8–12 hours for the first 72 postoperative hours. Changes in PTH levels as well as symptoms of hypocalcemia were correlated with postoperative hypocalcemia.RESULTSHypocalcemia developed in 13/40 patients (32.5%), mainly those patients undergoing total thyroidectomy in conjunction with paratracheal neck dissections. The respective sensitivity and specificity of a drop in PTH for detecting hypocalcemia was 92% and 66% (50% drop), 23% and 75% (75% drop), and 46% and 100% (drop below normal range).CONCLUSIONSA 50% drop in PTH levels 30 minutes following bilateral thyroid procedures is a sensitive predictor of hypocalcemia. A drop of 75% is a highly specific indicator of postoperative hypocalcemia, though not highly sensitive.
Tracheal Reconstruction with Porcine Small Intestine Submucosa in a Rabbit Model
Authors: Gubbels Samuel P. , Richardson Mark , Trune Dennis , Bascom Daphne A. , Wax Mark K. 
Published: May 2006

OBJECTIVETo evaluate the ability of porcine small intestine submucosa (SIS) to 1) maintain airway patency, 2) integrate, 3) prevent granulation tissue formation, and 4) permit mucosalization when used for tracheal reconstruction. Further studies were performed to evaluate the ability of SIS to support neochondrogenesis and investigate the impact of neochondrogenesis on airway patency.STUDY DESIGNProspective, controlled animal trial with SIS used with and without a perichondrial flap to reconstruct a tracheal defect in a rabbit model. Functional, histologic and endoscopic analyses were performed.RESULTSAll animals except 1 control animal were without stridor. The SIS graft supported neochondrogenesis, was completely mucosalized and was well integrated into the neotrachea. There was minimal granulation tissue formation. Endoscopic analyses did not reveal a consistent, significant difference in airway patency when SIS, with or without a perichondrial flap, was used for reconstruction.CONCLUSIONSIS can be used to reconstruct a sublethal rabbit tracheal defect with no mortality and minimal morbidity.
Does Topical Application of 5‐Fluorouracil Ointment Influence Inner Ear Function?
Authors: Iwanaga Tetsu , Tanaka Fujinobu , Tsukasaki Naoki , Terakado Mariko , Kaieda Satoru , Takasaki Kenji , Kumagami Hidetaka , Takahashi Haruo 
Published: May 2006

OBJECTIVETo investigate the effect of 5‐fluorouracil (5‐FU) ointment on the inner ear of guinea pigs.STUDY DESIGN AND SETTINGIn group A (n = 7), 5‐FU ointment was applied into the left external auditory canal. In group B (n = 10), 5‐FU ointment was applied to the left middle ear through myringotomy. In both groups, the right ear served as a control. One week later the endocochlear DC potential (EP) was measured and morphology of the cochleae was examined using scanning electron microscopy (SEM) and light microscopy.RESULTSIn group A, there was no significant difference between the EP values of the experimental side and the control side. In group B, there was a statistically significant difference between them (P < 0.05). Morphologic findings showed no damage.CONCLUSION5‐FU ointment application to the external ear seems to be safe but its application to the middle ear may pose some risk of ototoxicity.
Reduced pulmonary function in children with the Fontan circulation affects their exercise capacity
Authors: Matthews Iren Lindbak , Fredriksen Per Morten , Bjørnstad Per G. , Thaulow Erik , Gronn Morten 
Published: May 2006

Most children with functionally univentricular hearts nowadays are treated surgically by creating a total cavopulmonary connection. In the resulting Fontan circulation, the venous return and the pulmonary arterial bed are coupled in series, bypassing the heart. This gives the potential for interaction between the abnormal circulation and function of the lungs. In this study, we investigated the pattern of impairment of pulmonary function, and its relation to decreased exercise capacity.We performed spirometry in 33 (85 percent) of 39 eligible Norwegian children, aged from 8 to 16, with a total cavopulmonary connection, along with whole body plethysmography, the carbon monoxide single breath test, and a peak treadmill exercise test. The single breath test showed a mean corrected diffusing capacity of 66.5 percent of predicted, giving a z score of minus 2.88. The mean residual volume measured by whole body plethysmography was 146.8 percent, equivalent to a z score of 2.46, whereas the mean residual volume measured by the single breath test was 102.4 percent of predicted, this being the same as a z score of 0.43. The mean peak treadmill exercise test was 70.0 percent of predicted, equivalent with a z score of minus 3.07. Mean forced vital capacity was 85.7 percent of predicted, the equivalent z score being minus 0.92. Lung function correlated with the peak treadmill exercise test.We have shown, therefore, that children with the Fontan circulation have reduced diffusing capacity, possibly caused by the abnormal circulation through the lungs. The difference between residual volume measured by plethysmography and the single breath test implies trapping of air. The correlation of parameters for lung function with peak consumption of oxygen during exercise indicates that the abnormalities of pulmonary function may affect physical capacity.
Effect of Aging on the Structure and Function of Skeletal Muscle Microvascular Networks
Authors: BEARDEN SHAWN E. 
Published: May 2006

ABSTRACTHumans are active creatures, yet physical activity and activity tolerance decline over the life span. One prevailing theme in the literature to account for a portion of the reduced activity tolerance with aging is the observation that the capacity to augment blood flow to skeletal muscle may be impaired with advancing age. This dysfunction may be due to adaptations in the structure or function of their microvascular networks, which collectively determine blood flow resistance. The intent of this review is to present the current knowledge of structure and function of microvascular networks from skeletal muscle with special regard to how these may adapt to, or persist through, the aging process. Skeletal muscles are supplied by an intricate branching network of arterioles and venules. The consistency of findings among available studies suggests that the overall arteriolar and venular network branching topology establishes early in development and varies little, if at all, over the life span. Microvascular networks are not a series of functionally isolated segmental branches. Rather, these networks transmit and communicate vasomotor signals along their lengths and among their branches. Current evidence suggests that aging is associated with a decrement in the capacity of upstream vessels to respond to downstream vasodilation and signals transmitted cell‐to‐cell along the vascular wall.
A fresh look at the fossil evidence for early Archaean cellular life
Authors: Brasier Martin , McLoughlin Nicola , Green Owen , Wacey David 
Published: May 2006

The rock record provides us with unique evidence for testing models as to when and where cellular life first appeared on Earth. Its study, however, requires caution. The biogenicity of stromatolites and ‘microfossils’ older than 3.0 Gyr should not be accepted without critical analysis of morphospace and context, using multiple modern techniques, plus rejection of alternative non-biological (null) hypotheses. The previous view that the co-occurrence of biology-like morphology and carbonaceous chemistry in ancient, microfossil-like objects is a presumptive indicator of biogenicity is not enough. As with the famous Martian microfossils, we need to ask not ‘what do these structures remind us of?’, but ‘what are these structures?’ Earth's oldest putative ‘microfossil’ assemblages within 3.4–3.5 Gyr carbonaceous cherts, such as the Apex Chert, are likewise self-organizing structures that do not pass tests for biogenicity.There is a preservational paradox in the fossil record prior toca2.7 Gyr: suitable rocks (e.g. isotopically light carbonaceous cherts) are widely present, but signals of life are enigmatic and hard to decipher. One new approach includes detailed mapping of well-preserved sandstone grains in theca3.4 Gyr Strelley Pool Chert. These can contain endolithic microtubes showing syngenicity, grain selectivity and several levels of geochemical processing. Preliminary studies invite comparison with a class of ambient inclusion trails of putative microbial origin and with the activities of modern anaerobic proteobacteria and volcanic glass euendoliths.
Management of Chinese patients on warfarin therapy in two models of anticoagulation service – a prospective randomized trial
Authors: Chan Fredric W. H. , Wong Raymond S. M. , Lau Wing‐Hung , Chan Thomas Y. K. , Cheng Gregory , You Joyce H. S. 
Published: May 2006

AimTo compare the treatment outcomes of a clinical pharmacist‐managed anticoagulation service with physician‐managed service in Chinese patients.MethodsA prospective, randomized clinical trial was conducted at the anticoagulation clinic of a teaching hospital in Hong Kong. Patients aged ≥ 18 years who would required warfarin therapy for at least 3 months were recruited. Patients were randomized to the pharmacist‐managed or physician‐managed group. Primary clinical outcome was assessed by the percentage of patient time spent within the target international normalized ratio (INR) range. The incidence of major thromboembolic events (TEs) and major bleeding was assessed as secondary clinical outcomes. The cost per patient per month (cPPPM) was calculated and patient satisfaction was assessed by patient satisfaction questionnaire (PSQ)‐18.ResultsOne hundred and forty‐one patients were recruited at the anticoagulation clinic and 137 patients completed the study. Patients in the pharmacist‐managed group (n = 68) were in the target INR 64% of patient time vs. 59% in the physician‐managed group (n = 69) (P < 0.001). There was no significant difference in incidence of major TEs or bleeding. The cPPPM in the pharmacist‐managed group (US$76 ± 95) (£43 ± 53) was lower than in the physician‐managed group (US$98 ± 158) (£55 ± 89) (P < 0.001). The PSQ‐18 score of the pharmacist‐managed group (3.8 ± 0.2) was higher than that of the physician‐managed group (3.6 ± 0.3) (P < 0.001).ConclusionThe pharmacist‐managed anticoagulation service was more effective and less costly than the physician‐managed service in achieving target anticoagulation control for Chinese patients on warfarin therapy.