bluuebunny/crossref_metadata_2025_split huggingface dataset:
La4N2S3: Ein neues Nitridsulfid des Lanthans mit beispielloser Kristallstruktur
Authors: Lissner Falk , Schleid Thomas 
Published: May 2006

AbstractLa4N2S3: A New Nitride Sulfide of Lanthanum with Unprecedented Crystal StructureThe oxidation of lanthanum powder with sulfur and cesium azide (CsN3) in the presence of lanthanum tribromide (LaBr3) yields lanthanum nitride sulfide with the composition La4N2S3 when appropriate molar ratios of the reactants are used. Additional cesium bromide (CsBr) as a flux secures fast reactions (7 d) at 900 °C in evacuated silica tubes as well as the formation of almost black single crystals. The orthorhombic crystal structure (Pnnm, Z = 2) was determined from single crystal X‐ray diffraction data (a = 641.98(4), b = 1581.42(9), c = 409.87(3) pm). Two crystallographically different La3+ cations are present, La1 resides in sixfold coordination of two N3− and four S2− anions forming a trigonal prism and La2 is coordinated by two N3− and five S2− in the shape of a monocapped trigonal prism. However, the main feature of the crystal structure comprises N3−‐centred (La3+)4 tetrahedra which arrange as pairs [N2La6]12+ of edge‐shared [NLa4]9+ units and which are further connected via four vertices to form double chains $^{1}_{\infty}\rm \{[N_{2}La_{2}La^{\prime}_{4/2}]^{6+}\}$. They get bundled along [001] like a hexagonal rod packing and are held together by two crystallographically different S2− anions. Further motifs for the connectivity of [NM4]9+ tetrahedra in crystal structures of nitride chalcogenides and halides of the rare‐earth elements (M = Sc, Y, La; Ce – Lu) with ratios of N : M = 1 : 2 are presented and discussed for comparison.
Li6+2x[B10Se18]Sex (x ≈ 2), ein ionenleitendes Doppelsalz
Authors: Hammerschmidt A. , Döch M. , Pütz S. , Eckert H. , Krebs B. 
Published: May 2006

AbstractLi6+2x[B10Se18]Sex (x ≈ 2), an Ion‐conducting Double SaltLi6+2x[B10Se18]Sex (x ≈ 2) was prepared in a solid state reaction from lithium selenide, amorphous boron and selenium in evacuated carbon coated silica tubes at a temperature of 800 °C. Subsequent cooling from 600 °C to 300 °C gave amber colored crystals with the following lattice parameters: space group I2/a (at 173 K); a = 17.411(1) Å, b = 21.900(1) Å, c = 17.820(1) Å, β = 101.6(1)°. The crystal structure contains a well‐defined polymeric selenoborate network of composition ([B10Se16Se4/2]6−)n consisting of a system of edge‐sharing [B10Se16Se4/2] adamantanoid macro‐tetrahedra forming large channels in which a strongly disorderd system of partial occupied Li+ cations and additional disordered Se2− anions is observed. The crystal structure of the novel selenoborate is isotypic to Li6+2x[B10S18]Sx (x ≈ 2) [1]. X‐ray and 7Li magic‐angle spinning NMR data suggest that the site occupancies of the three crystallographically distinct lithium ions exhibit a significant temperature dependence. The lithium ion mobility has been characterized by detailed temperature dependent NMR lineshape and spin‐lattice relaxation measurements.
Die Aluminidiodide La24Al12I21 und La10Al5I8: Verbindungen mit intermetallischen La‐Al‐Bereichen und La‐Al‐Clustern
Authors: Mattausch Hansjürgen , Oeckler Oliver , Hoch Constantin , Simon Arndt 
Published: May 2006

AbstractThe Aluminide Iodides La24Al12I21 and La10Al5I8: Compounds with Intermetallic La‐Al Fractions and La‐Al ClustersReacting pieces of La, LaI3 and Al filings (molar ratio 22 : 8 : 15) at 800 °C–825 °C results in La24Al12I21 (70 % yield) together with La10Al5I8 (10 % yield), besides known La3Al2I2 and La2Al2I. Both new compounds form golden coloured needles. La10Al5I8 is brittle, whereas La24Al12I21 is shaped as hair‐like easily deformable bundles. Both are monoclinic, space group C2/m, La24Al12I21 with a = 35.753(7) Å, b = 4.327(1) Å, c = 27.442(6) Å, β = 116.62(3)° and La10Al5I8 with a = 19.649(1) Å, b = 4.296(1) Å, c = 18.0290(1) Å and β = 96.67(3)°. The La atoms form trigonal prisms condensed into double chains along [010]. The La prisms are centered by Al atoms which form Al6 rings connected into chains. The La‐Al strands are surrounded by I atoms in La24Al12I21, whereas in La10Al5I8 they are connected to form corrugated sheets separated by close packed layers of I atoms together with Al atoms. The octahedral voids around the Al atoms are occupied by La atoms, and such La6Al clusters are connected via opposite edges to octahedra chains along [010].
Rhenium‐Dicarbonyl‐Nitrosyl‐Komplexe mit Imidazol
Authors: Rattat Dirk , Verbruggen Alfons , Berke Heinz 
Published: May 2006

AbstractRhenium Dicarbonyl‐Nitrosyl Complexes with ImidazoleDifferent rhenium‐dicarbonyl‐nitrosyl complexes with imidazole (Im) as monodentate ligand have been synthesized and characterized, starting from [NEt4][ReCl3(CO)2(NO)] and [ReCl(μ−Cl)(CO)2(NO)]2. Whereas the complexes [ReCl2(Im)(CO)2(NO)] and [ReCl(Im)2(CO)2(NO)]+ were achieved in high yields, the complex [Re(Im)3(CO)2(NO)]2+ with three imidazole ligands could only be isolated after complete removal of all halide ions (with AgBF4) in low yield. The synthesis of a corresponding 99mTc‐dicarbonyl‐nitrosyl complex with imidazole opens a new perspective for such compounds as potential radiopharmaceuticals and alternatives to the already established 99mTc‐tricarbonyl complexes.
A New Europium(II) Oxide Iodide: Eu2OI2
Authors: Hammerich Stefanie , Meyer Gerd 
Published: May 2006

AbstractRed single crystals of Eu2OI2 were obtained from a reaction mixture of barium metal, EuI2, Eu4OI6 and some NH4I in a tantalum tube at 780/500 °C. The crystal structure (orthorhombic, Imcb, Z = 4, a = 648.93(11), b = 742.85(13), c = 1307.1(3) pm, R1(all) = 0.0605) contains {Eu4O} tetrahedra connected via trans‐edges to infinite chains. The iodide ions surround and connect these chains to a three‐dimensional structure.
The Structural Systematics of Protonation of Some Important Nitrogen‐base Ligands. III. Some (Univalent) Anion Salts of some Hindered Unidentate Nitrogen Bases
Authors: Effendy  , Junk Peter C. , Kepert Cameron J. , Louis Lance M. , Morien Travis C. , Skelton Brian W. , White Allan H. 
Published: May 2006

AbstractRecent structural studies of salts of the 2,2,6,6‐tetramethylpiperidinium cation [tmpH]+ (chloride, bromide; thiocyanate) present as interesting dimeric or polymeric associations linked by pairs of directional hydrogen‐bonds from the cationic = ${\rm NH}^{+}_{2}$ moieties to ‘two‐coordinate’ anions. Present single crystal X‐ray studies have characterized the iodide, perchlorate, nitrate and trifluoroacetate complexes, all, like those of the preceding studies, of composition [tmpH]+X− (anhydrous). A variety of forms are found: the nitrate compound is dimeric [[tmpH](O·NO·O)2[Htmp]], the trifluoroacetate compound being similar in form while the iodide and perchlorate salts are mixtures of dimers (with the anions essentially single atom bridges) and single‐stranded helical polymers, the stoichiometric ratio of these being 1:1 and 2:1 in terms of [tmpH]X formula units, respectively. A study of 4‐keto‐2,2,6,6‐tetramethyl‐piperidinium thiocyanate shows it to be a dimer $\left [ [{\rm OtmpH}] \left (^{\rm SCN}_{\rm NSC} \right ) [{\rm HtmpO}] \right ]$ unlike its previously studied chloride analogue which is a cyclic tetramer. A new P21/n phase of di‐isopropylammonium chloride, derivative of the previously described P212121 and P21 forms, is reported, together with descriptions of protonated salts of the other hindered unidentate bases 2,6‐lutidine (as the chloride salt), quinoline (as the perchlorate, trifluoroacetate, hexachlorostannate and bisulfate salts) and 2‐quinaldine (as the chloride (anhydrous and monohydrate) and hexachlorostannate salts), all displaying arrays derivative of ion‐pair formation (extended by anion‐anion hydrogen‐bonds as well in the bisulfate salt) and, in the case of the aromatic bases, dominated by parallel stacking.
The Structural Systematics of Protonation of Some Important Nitrogen‐Base Ligands. V. Some Univalent Anion Salts of Mono‐ and Bis(2‐picolyl)amine
Authors: Junk Peter C. , Kim Yang , Skelton Brian W. , White Allan H. 
Published: May 2006

AbstractA variety of salts derivative of bis(2‐picolyl)amine, ‘dipic’ = [{(C5NH4)(CH2)}2NH] in various stages of protonation have been structurally characterized, showing a considerable diversity of hydrogen‐bonding modes and interactions. For the triprotonated species (protonating hydrogen atoms on all three nitrogen atoms) the arrays are haphazard ([picH3]X3, X = Cl(·H2O), I(·H2O), NO3, tfs (= trifluoromethanesulfonate)(·H2O). For the diprotonated species, diverse forms are also found: in [dipicH2]Br2, the central nitrogen atom and one of the peripheral are protonated, but in the remainder, both peripheral nitrogen atoms are protonated, leading to a propensity to chelating interactions with an anion (as in the mixed anion salts ${\rm CL}^{-}\cdot{\rm I}^{-}_{3}$ and ${\rm I}^{-}\cdot{\rm I}^{-}_{3}$, where ${\rm I}^{-}_{3}$ does not interact) or a water molecule (in the I·2H2O salt) or anion (in the tfs salt) oxygen atom; in the nitrate salt, the ligand is twisted so that each pyridinium component interacts with an independent nitrate. By contrast, in the singly protonated species, [dipicH]X, the central nitrogen atom is protonated in all cases (X = Br, I, ClO4, thf). The tfs− salt is remarkable, containing a pair of cations with self‐interactions. In [picH]X only the aliphatic nitrogen is protonated (X = I−, ${\rm NO}^{-}_{3}$, ${\rm ClO}^{-}_{4}$, tfa− (= trifluoroacetate)). A single example of a diprotonated species [picH2]Cl2 has also been defined.
The Coordination Chemistry of Iron with the 1,4‐Bis(2‐pyridyl‐methyl)piperazine Ligand
Authors: Ostermeier Marc , Limberg Christian , Ziemer Burkhard 
Published: May 2006

AbstractThe behaviour of FeII and FeIII ions in combination with the potential ligand 1,4‐bis(2‐pyridyl‐methyl)piperazine (BPMP) under anhydrous conditions has been investigated. BPMP has been reacted with FeCl2, FeCl3 and [Fe(OTf)2(MeCN)2]. This led to the isolation of four new complexes, which were fully characterized and structurally investigated by single crystal X‐ray diffraction. It turned out that in the presence of chloride co‐ligands FeIII favours the tetradentate coordination mode of BPMP with the piperazine unit in a boat configuration, like for instance in [BPMP(Cl)Fe(μ‐O)FeCl3] or [BPMP‐FeCl2][FeCl4], (1). However, the employment of FeCl2 leads to the formation of a coordination polymer [BPMP‐FeCl2]n, (2), containing the piperazine ring in a chair configuration binding to two iron centres each. 2 can only be dissolved in very polar solvents like dmf which is capable of breaking up the polymeric structure under formation of [Cl2(dmf)Fe(μ‐BPMP‐1κ2N,N:2κ2N,N))Fe(dmf)Cl2]·2 dmf, (3). In contrast, using [Fe(OTf)2(MeCN)2] instead of FeCl2 as the starting material leads to a mononuclear FeII complex with BPMP bound in the desirable tetradentate fashion: [BPMP‐Fe(OTf)2], (4). Unlike other complexes with tetradentate N/py ligands the two residual ligands in 4 are bound almost trans to each other with the potential to adopt a cis orientation under oxidising conditions, and it will be interesting to exploit its catalytic properties in future.
Vibrational Spectra of Cluster Anions. 2. Vibrational Spectra of Compounds with the Cluster Anions [E4]4−: M4E4 (M = K, Rb, Cs; E = Ge, Sn) and β‐Na4Sn4
Authors: Somer Mehmet , Aydemir Umut , Baitinger Michael , von Schnering Hans Georg 
Published: May 2006

AbstractVibrational spectra of the compounds M4E4 (M = K, Rb, Cs; E = Ge, Sn) and of β‐Na4Sn4 with the cluster anions [E4]4− were analysed based on the point group ${\bar 4}{\rm 3}m-T_{d}$ of isolated tetrahedranide units. The lower individual ${\bar 4}{\rm 2}m-D_{2d}$ symmetry of the anions in the real structure being more patterned and complex primarily affects the spectra of the tetrahedro‐tetragermanides. ν3(F2) clearly splits both in Raman and IR and in the case of K4Sn4 only in IR. Rb4Sn4 and Cs4Sn4 exhibit very simple spectra with three bands in Raman and one band in IR. The breathing mode ν1(A1) for the quasi isolated [E4]4− cluster appears only in the Raman spectrum and is hardly influenced by the structural environment and by the nature of the alkali metal cations: ν1(A1) = 274 cm−1 ([Ge4]4−) and 183‐187 cm−1 ([Sn4]4−), respectively. The calculated valence force constants fd(E–E) are: [Ge4]4−: fd = 0.89 Ncm−1 (K), 0.87 Ncm−1 (Rb), 0.86 Ncm−1 (Cs) and [Sn4]4−: 0.67 Ncm−1 (Na), 0.66 Ncm−1 (K), 0.67 Ncm−1 (Rb), 0.68 Ncm−1 (Cs). Both, the frequencies and the force constants fit well into the range previously reported.
Adolescents’ views of food and eating: Identifying barriers to healthy eating
Authors: Stevenson Clifford , Doherty Glenda , Barnett Julie , Muldoon Orla T. , Trew Karen 
Published: May 2006

ABSTRACTContemporary Western society has encouraged an obesogenic culture of eating amongst youth. Multiple factors may influence an adolescent's susceptibility to this eating culture, and thus act as a barrier to healthy eating. Given the increasing prevalence of obesity amongst adolescents, the need to reduce these barriers has become a necessity. Twelve focus group discussions of single‐sex groups of boys or girls ranging from early to‐mid adolescence (N=73) were employed to identify key perceptions of, and influences upon, healthy eating behaviour. Thematic analysis identified four key factors as barriers to healthy eating. These factors were: physical and psychological reinforcement of eating behaviour; perceptions of food and eating behaviour; perceptions of contradictory food‐related social pressures; and perceptions of the concept of healthy eating itself. Overall, healthy eating as a goal in its own right is notably absent from the data and would appear to be elided by competing pressures to eat unhealthily and to lose weight. This insight should inform the development of future food‐related communications to adolescents.
Prognostic role of myocardial tumor necrosis factor‐alpha and terminal complement complex expression in patients with dilated cardiomyopathy
Authors: Zimmermann Oliver , Kochs Matthias , Zwaka Thomas P. , Bienek‐Ziolkowski Magdalena , Höher Martin , Hombach Vinzenz , Torzewski Jan 
Published: May 2006

AbstractBackground:In patients with dilated cardiomyopathy (DCM), elevated plasma levels of tumor necrosis factor‐α (TNF‐α) are associated with poor prognosis. The terminal complement complex (C5b‐9) stimulates myocardial TNF‐α expression.Aims:To investigate whether myocardial TNF‐α and C5b‐9 expression correlate with clinical outcome in DCM.Methods and results:71 patients with DCM underwent myocardial biopsy. Biopsies were analyzed for TNF‐α, C5b‐9, markers of inflammation and for viral genome. Patients were divided into three groups according to biopsy results: group A: no TNF‐α and no C5b‐9; group B: TNF‐α or C5b‐9; and group C: TNF‐α and C5b‐9. NYHA classification, ECG and echocardiography were documented. Patients received conventional treatment of heart failure and, in a few cases, additional treatment with interferon β1b (virus positive) or prednisolone (inflammatory DCM).There were 13 patients (18%) in group A, 19 patients (27%) in group B, and 39 patients (55%) in group C. All groups had a similar and significant improvement in NYHA classification and echocardiographic parameters. TNF‐α and C5b‐9 did not significantly correlate with the presence of viral genome or with markers of inflammation.Conclusion:TNF‐α and C5b‐9 are widely distributed in the myocardium of DCM patients. Neither of the antigens correlates with clinical outcome. Myocardial TNF‐α may not be a useful prognostic marker in DCM.
A multiproxy environmental investigation of Holocene wood from a submerged conifer forest in Lake Huron, USA
Authors: Hunter R. Douglas , Panyushkina Irina P. , Leavitt Steven W. , Wiedenhoeft Alex C. , Zawiskie John 
Published: May 2006

AbstractRemains of a Holocene drowned forest in southern Lake Huron discovered in 12.5 m of water (164 m above sea level), 4.5 km east of Lexington, Michigan USA (Sanilac site), provided wood to investigate environment and lake history using several proxies. Macrofossil evidence indicates a forest comprised primarily of conifers equivalent to the modern “rich conifer swamp” community, despite generally low regional abundance of these species in pollen records. Ages range from 7095 ± 50 to 6420 ± 70 14C yr BP, but the clustering of stump dates and the development of 2 floating tree-ring chronologies suggest a briefer forest interval of no more than c. 400 years. Dendrochronological analysis indicates an environment with high inter-annual climate variability. Stable-carbon isotope composition falls within the range of modern trees from this region, but the stable-oxygen composition is consistent with warmer conditions than today. Both our tree-ring and isotope data provide support for a warmer environment in this region, consistent with a mid-Holocene thermal maximum. This drowned forest also provides a dated elevation in the Nipissing transgression at about 6420 14C yr BP (7350 cal yr BP) in the southern Lake Huron basin, a few hundred years before reopening of the St. Clair River drainage.
Cd-hit: a fast program for clustering and comparing large sets of protein or nucleotide sequences
Authors: Li Weizhong , Godzik Adam 
Published: May 2006

Abstract
Motivation: In 2001 and 2002, we published two papers (Bioinformatics, 17, 282–283, Bioinformatics, 18, 77–82) describing an ultrafast protein sequence clustering program called cd-hit. This program can efficiently cluster a huge protein database with millions of sequences. However, the applications of the underlying algorithm are not limited to only protein sequences clustering, here we present several new programs using the same algorithm including cd-hit-2d, cd-hit-est and cd-hit-est-2d. Cd-hit-2d compares two protein datasets and reports similar matches between them; cd-hit-est clusters a DNA/RNA sequence database and cd-hit-est-2d compares two nucleotide datasets. All these programs can handle huge datasets with millions of sequences and can be hundreds of times faster than methods based on the popular sequence comparison and database search tools, such as BLAST.
Availability:
Contact: liwz@sdsc.edu
Metatool 5.0: fast and flexible elementary modes analysis
Authors: Kamp Axel von , Schuster Stefan 
Published: May 2006

Abstract
Summary: Elementary modes analysis is a powerful tool in the constraint-based modeling of metabolic networks. In recent years, new approaches to calculating elementary modes in biochemical reaction networks have been developed. As a consequence, the program Metatool, which is one of the first programs dedicated to this purpose, has been reimplemented in order to make use of these new approaches. The performance of Metatool has been significantly increased and the new version 5.0 can now be run inside the GNU octave or Matlab environments to allow more flexible usage and integration with other tools.
Availability: The script files and compiled shared libraries can be downloaded from the Metatool website at . Metatool consists of script files (m-files) for GNU octave as well as Matlab and shared libraries. The scripts are licensed under the GNU Public License and the use of the shared libraries is free for academic users and testing purposes. Commercial use of Metatool requires a special contract.
Contact: kamp@minet.uni-jena.de
ACE-it: a tool for genome-wide integration of gene dosage and RNA expression data
Authors: van Wieringen Wessel N. , Belien Jeroen A. M. , Vosse Sjoerd J. , Achame Eskeatnaf M. , Ylstra Bauke 
Published: May 2006

AbstractSummary: We describe a tool, called ACE-it (Array CGH Expression integration tool). ACE-it links the chromosomal position of the gene dosage measured by array CGH to the genes measured by the expression array. ACE-it uses this link to statistically test whether gene dosage affects RNA expression.Availability: ACE-it is freely available atContact: b.ylstra@vumc.nlSupplementary Information: Programs, the manual and supplementary information are available on the website.
Scanning microarrays at multiple intensities enhances discovery of differentially expressed genes
Authors: Skibbe David S. , Wang Xiujuan , Zhao Xuefeng , Borsuk Lisa A. , Nettleton Dan , Schnable Patrick S. 
Published: May 2006

Abstract
Motivation: Scanning parameters are often overlooked when optimizing microarray experiments. A scanning approach that extends the dynamic data range by acquiring multiple scans of different intensities has been developed. Results: Data from each of three scan intensities (low, medium, high) were analyzed separately using multiple scan and linear regression approaches to identify and compare the sets of genes that exhibit statistically significant differential expression. In the multiple scan approach only one-third of the differentially expressed genes were shared among the three intensities, and each scan intensity identified unique sets of differentially expressed genes. The set of differentially expressed genes from any one scan amounted to &lt;70% of the total number of genes identified in at least one scan. The average signal intensity of genes that exhibited statistically significant changes in expression was highest for the low-intensity scan and lowest for the high-intensity scan, suggesting that low-intensity scans may be best for detecting expression differences in high-signal genes, while high-intensity scans may be best for detecting expression differences in low-signal genes. Comparison of the differentially expressed genes identified in the multiple scan and linear regression approaches revealed that the multiple scan approach effectively identifies a subset of statistically significant genes that linear regression approach is unable to identify. Quantitative RT–PCR (qRT–PCR) tests demonstrated that statistically significant differences identified at all three scan intensities can be verified.
Availability: The data presented can be viewed at under GEO accession no. GSE3017.
Contact: schnable@iastate.edu
Supplementary information: Data from these experiments can be viewed at
Spatial stochastic modelling of the phosphoenolpyruvate-dependent phosphotransferase (PTS) pathway in Escherichia coli
Authors: Rodríguez J. Vidal , Kaandorp Jaap A. , Dobrzyński Maciej , Blom Joke G. 
Published: May 2006

Abstract
Motivation: Many biochemical networks involve reactions localized on the cell membrane. This can give rise to spatial gradients of the concentration of cytosolic species. Moreover, the number of membrane molecules can be small and stochastic effects can become relevant. Pathways usually consist of a complex interaction network and are characterized by a large set of parameters. The inclusion of spatial and stochastic effects is a major challenge in developing quantitative and dynamic models of pathways.
Results: We have developed a particle-based spatial stochastic method (GMP) to simulate biochemical networks in space, including fluctuations from the diffusion of particles and reactions. Gradients emerging from membrane reactions can be resolved. As case studies for the GMP method we used a simple gene expression system and the phosphoenolpyruvate:glucose phosphotransferase system pathway.
Availability: The source code for the GMP method is available at
Contact: jrodrigu@science.uva.nl