bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ribbed moraine stratigraphy and formation in southern Finnish Lapland
Authors: Sarala Pertti 
Published: May 2006

AbstractCharacteristics of ribbed moraines, the dominating moraine type in southern Finnish Lapland, have been studied in detail. The ridges are composed of several till units, of which the bottommost units consist of mature basal tills and the surficial parts are enriched with local, short‐transport rock fragments and boulders in till and at the surface of ridges. As a result of this re‐examination a two‐step model of the formation process of ribbed moraines is presented. In the first stage, while cold‐based conditions prevailed, both the bottommost part of the ice sheet and the frozen, substrate fractured under compressive ice flow. Following glacial transport of fractured blocks and formation of the transverse ridge morphology, erosion between the ridges continued owing to freeze–thaw process under variable pressure conditions. In the areas with a low pre‐existing till sheet, the process caused quarrying of the bedrock surface and subsequent deposition of rock fragments and boulders under high pressure on the next ridge. The most suitable conditions for ribbed moraine formation existed during Late Weichselian deglaciation, after the Younger Dryas when the climate warmed very quickly, leading to an imbalance between a warm glacier surface and a cold base. Copyright © 2006 John Wiley & Sons, Ltd.
Event driven electrical stimulation of the dorsal penile/clitoral nerve for management of neurogenic detrusor overactivity in multiple sclerosis
Authors: Fjorback Morten Voss , Rijkhoff Nico , Petersen Thor , Nohr Mads , Sinkjaer Thomas 
Published: May 2006

AbstractAimsThe aim of this study was to evaluate the effect of automatic event driven electrical stimulation on the dorsal penile/clitoral nerve for management of neurogenic detrusor overactivity in patients suffering from Multiple Sclerosis.MethodsA total of 10 patients participated in the study. Detrusor pressure was recorded during physiological filling of the bladder and electrical stimulation was applied with surface electrodes whenever the detrusor pressure exceeded 10 cm H2O.ResultsIn seven of the eight patients, where neurogenic detrusor overactivity was observed an average of 12 detrusor contractions could be inhibited by stimulation. In one patient, however, stimulation failed to inhibit the detrusor contractions. The average increase in bladder volume from first suppressed detrusor contraction until leakage was 94% (range: 22–366%). On average, the time from first suppressed contraction until leakage was 15 min and 50 sec (range: 4 min 58 sec–32 min 5 sec) with an average physiological filling rate of 8 ml/min. Urgency was effectively suppressed at the onset of stimulation.ConclusionsThe results indicate that involuntary detrusor contractions in patients with multiple sclerosis can effectively be inhibited with event driven stimulation, hereby improving bladder capacity and reducing the number of incontinence episodes. However, the used method for detecting detrusor contractions is not suitable in a chronic setting and alternative techniques needs to be investigated if stimulation should be applied automatically. Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.
Parasitoid wasp sting: A cocktail of GABA, taurine, and β‐alanine opens chloride channels for central synaptic block and transient paralysis of a cockroach host
Authors: Moore Eugene L. , Haspel Gal , Libersat Frederic , Adams Michael E. 
Published: May 2006

AbstractThe wasp Ampulex compressa injects venom directly into the prothoracic ganglion of its cockroach host to induce a transient paralysis of the front legs. To identify the biochemical basis for this paralysis, we separated venom components according to molecular size and tested fractions for inhibition of synaptic transmission at the cockroach cercal‐giant synapse. Only fractions in the low molecular weight range (<2 kDa) caused synaptic block. Dabsylation of venom components and analysis by HPLC and MALDI‐TOF‐MS revealed high levels of GABA (25 mM), and its receptor agonists β‐alanine (18 mM), and taurine (9 mM) in the active fractions. Each component produces transient block of synaptic transmission at the cercal‐giant synapse and block of efferent motor output from the prothoracic ganglion, which mimics effects produced by injection of whole venom. Whole venom evokes picrotoxin‐sensitive chloride currents in cockroach central neurons, consistent with a GABAergic action. Together these data demonstrate that Ampulex utilizes GABAergic chloride channel activation as a strategy for central synaptic block to induce transient and focal leg paralysis in its host. © 2006 Wiley Periodicals, Inc. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006
Effects of electron irradiation on poly(vinylidene fluoride–trifluoroethylene) copolymers studied by solid‐state nuclear magnetic resonance spectroscopy
Authors: Wang Liying , Zhao Xingzhong , Feng Jiwen 
Published: May 2006

AbstractThe effects of electron irradiation on the molecular chemical structure, conformation, mobility, and phase transition of vinylidene fluoride (VDF) and trifluoroethylene (TrFE) copolymer have been investigated with variable‐temperature, solid‐state 19F nuclear magnetic resonance (NMR). It has been found that electron irradiation converts all‐trans conformations of both VDF‐rich and TrFE‐containing segments into dynamically mixed trans–gauche conformations accompanied by a simultaneous ferroelectric‐to‐paraelectric (or amorphous) transition. The variable‐temperature 19F magic‐angle‐spinning spectra results show that the paraelectric phase melts at much lower temperatures in irradiated films than in an unirradiated sample. Moreover, 19F NMR relaxation data (spin–lattice relaxation times in both the laboratory and rotating frames) reveal that electron irradiation enhances the molecular motion in paraelectric regions, whereas the molecular motion in a high‐temperature amorphous melt (>100 °C) is more constrained in irradiated films. Besides these physical changes, electron irradiation also induces the formation of several CF3 groups. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1714–1724, 2006
Gd3+ and Eu2+ local environment in Ca1–xEuxB6 (0.0001 ≤ x ≤ 0.30) and Ca1–xGdxB6 (0.0001 ≤ x ≤ 0.01)
Authors: Urbano R. R. , Pagliuso P. G. , Rettori C. , Schlottmann P. , Fisk Z. , Chapler B. , Oseroff S. B. 
Published: May 2006

AbstractLocal environment of Gd3+ and Eu2+ 4f7 ions, S = 7/2, in Ca1–x Eux B6 (0.0001 ≤ x ≤ 0.30) and Cax Gdx B6 (0.0001 ≤ x ≤ 0.01) is investigated by means of electron spin resonance (ESR). For x ≤ 0.001 the spectra show resolved fine structures due to the cubic crystal electric field and, in the case of Eu, the hyperfine structure due to the nuclear hyperfine field is also observed. The resonances have Lorentzian line shape, indicating insulating host for the Gd3+ and Eu2+ ions. As x increases, the ESR lines broaden due to local distortions caused by the Ca/Gd,Eu ions substitution. For Gd (x ≈ 0.001) and Eu (x ≈ 0.02), the spectra present superposition of Lorentzian and Dysonian resonances, suggesting a coexistence of insulating and metallic hosts for the Gd3+ and Eu2+ ions. The Gd3+ and Eu2+ fine structures are still observable up to x ≈ 0.003 for Gd and x ≈ 0.15 for Eu. For larger values of x the fine and hyperfine structures are no longer observed, the line width increases, and the line shape becomes pure Dysonian anticipating the metallic and semimetallic character of GdB6 and EuB6, respectively. These results clearly show that in the low concentration regime the Ca1–x Rx B6 (R = Gd, Eu) systems are intrinsically inhomogeneous. No evidence of weak ferromagnetism (WF) was found in the ESR spectra of either metallic or insulating phases of these compounds, suggesting that, if WF is present in these materials, the Gd3+ and Eu2+ 4f7‐electrons are shielded from the WF field. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
AlGaN multiple quantum well based deep UV LEDs and their applications
Authors: Asif Khan M. 
Published: May 2006

AbstractIn this paper we will describe the approaches that we have used to grow AlGaN‐based multiple quantum well deep UV LED structures and to overcome issues of doping efficiency, cracking, and slow growth rates both for the n‐ and the p‐type layers of the device structures. This has led to the fabrication of devices with emission from 250–340 nm and cw‐milliwatt powers at pump currents of only 20 mA (V f ≤ 6 V). Record wall plug efficiencies as high as 1.5% are now achievable for devices with emission at 280 nm. Thermal management and a proper device design are not only a key to achieving these record performance numbers but are also crucial to device reliability. We will also discuss some of our initial research to clarify the factors influencing the lifetime of the deep UV LEDs. In addition to our own work, we will review the results from the excellent research carried out at several other laboratories worldwide. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
1‐Oxa‐nido‐dodecaborate [OB11H12]− from the Controlled Oxidation of the closo‐Borates [B11H11]2− and [B12H12]2−
Authors: Volkov Oleg , Paetzold Peter , Hu Chunhua 
Published: May 2006

AbstractThe closo‐dodecaborate [B12H12]2− is degraded at room temperature by oxygen in an acidic aqueous solution in the course of several weeks to give B(OH)3. The degradation is induced by Ag2+ ions, generated from Ag+ by the action of H2S2O8. Oxa‐nido‐dodecaborate(1−) is an intermediate anion, that can be separated from the reaction mixture as [NBzlEt3][OB11H12] after five days in a yield of 18 %. The action of FeCl3 on the closo‐undecaborate [B11H11]2− in an aqueous solution gives either [B22H22]2− (by fusion) or nido‐B11H13(OH)− (by protonation and hydration), depending on the concentration of FeCl3. In acetonitrile, however, [B11H11]2− is transformed into [OB11H12]− by Fe3+ and oxygen. The radical anions [B12H12]˙− and [B11H11]˙− are assumed to be the primary products of the oxidation with the one‐electron oxidants Ag2+ and Fe3+, respectively. These radical anions are subsequently transformed into [OB11H12]− by oxygen. The crystal structure analysis shows that the structure of [OB11H12]− is derived from the hypothetical closo‐oxaborane OB12H12 by removal of the B3 vertex, leaving a non‐planar pentagonal aperture with a three‐coordinate O vertex, as predicted by NMR spectra and theory.
Structure and Magnetic Properties of Ce3Ge0.66In4.34 and Ce11Ge4.74In5.26
Authors: Zaremba Vasyl' I. , Kaczorowski Dariusz , Nychyporuk Galyna P. , Rodewald Ute Ch. , Heying Birgit , Pöttgen Rainer 
Published: May 2006

AbstractNew indides Ce3Ge0.66In4.34 and Ce11Ge4.74In5.26 were synthesized from the elements by arc‐melting and subsequent annealing at 870 K. Single crystals were grown through special annealing procedures in sealed tantalum tubes in a high‐frequency furnace. Both compounds were investigated on the basis of X‐ray powder and single crystal data: I4/mcm, La3GeIn4 type, a = 848.8(1), c = 1192.0(2) pm, Z = 4, wR2 = 0.0453, 499 F2 values, 17 variables for Ce3Ge0.66In4.34 and I4/mmm, Sm11Ge4In6 type (ordered version of the Ho11Ge10 type), a = 1199.3(2), c = 1662.0(3) pm, wR2 = 0.0507, 1217 F2 values, 41 variables for Ce11Ge4.74In5.26. The Ce3Ge0.66In4.34 structure shows a mixed Ge/In occupancy on the 4c Wyckoff position. This site is octahedrally coordinated by cerium atoms. These octahedra share all edges, leading to a three‐dimensional network. The latter is penetrated by a two‐dimensional indium substructure which consists of flattened tetrahedra at In–In distances of 291 and 300 pm. The Ce11Ge4.74In5.26 structure contains three crystallographically independent germanium sites. The latter are coordinated by eight or nine cerium neighbors. These CN8 and CN9 polyhedra are condensed to a complex network which is penetrated by a three‐dimensional indium network with In–In distances of 301–314 pm. The 16m site shows a mixed In/Ge occupancy. Chemical bonding in both compounds is dominated by the p elements. Both ternaries studied exhibit localized magnetism due to the presence of Ce3+ ions. The compound Ce3GeIn4 remains paramagnetic down to 1.72 K, whereas Ce11Ge4In6 orders ferromagnetically at TC = 7.5 K.
Lanthanides as d Metals
Authors: Simon Arndt , Mattausch Hansjürgen , Ryazanov Mikhail , Kremer Reinhard K. 
Published: May 2006

Abstract Reduction of lanthanide trihalides with alkali metals along the route used by Klemm and Bommer leads to pure lanthanide metals. In closed Ta capsules at elevated temperatures, however, metal‐rich halides form which use the excess of Ln centered electrons for metal‐metal bonding. An overview of the extended d metal chemistry of lanthanides in binary, ternary and quaternary halides is presented. Consequences of the mutual interaction of d and f electrons are illustrated for selected magnetic and electrical properties.
A Mononuclear η2‐Bonded Phosphaalkyne Nickel(0) Complex
Authors: Schaub Thomas , Radius Udo 
Published: May 2006

AbstractThe synthesis and characterization of the new complex [Ni(ImiPr)2(η2‐P≡C‐tBu)] (1) is reported. Compound 1 represents the first structurally characterized example of a mononuclear nickel(0) complex with a side on coordinated phophaalkyne ligand.
High‐valent Molybdenum Imido Complexes with Tethered Olefins
Authors: Siewert Inke , Limberg Christian , Ziemer Burkhard 
Published: May 2006

AbstractAgainst the background of the (propene)Mo(=O)(=NH) and (allyl)Mo(=O)(=NH) surface species suggested as intermediates of the SOHIO process the potential of H2N–C6H4–CH2– CH=CH–CH3, (I), for the introduction of chelating imido/olefin or imido/allyl ligands at highvalent Mo centres was tested. Reaction of I with Na2[MoO4] and trimethylchlorosilane yielded [Cl2Mo(=N–C6H4–CH2–CH=CH–CH3)2(dme)] (1), containing pendant olefinic arms. All attempts to introduce the olefin into the coordination sphere of the Mo centre failed. The same observation was made with [Cl2Mo(=O)(=N–C6H4–CH2–CH=CH–CH3)(dme)] (2), synthesised via a commutation reaction from 1 and[(dme)Cl2Mo(=O)2]. Reaction of three equivalents of I with [CpMoCl4′] yields [CpCl2Mo(=N–C6H4–CH2–CH=CH–CH3)], (3), again with a pendant olefin arm; the products of experiments aiming at coordinating it to the Mo atom eluded isolation. I thus does not seem suitable for the synthesis of complexes with imido/olefin or imido/allyl ligands. However, products 1–3, (two of which (1, 3) were also characterised by single crystal X‐ray diffraction) are nevertheless interesting, e.g., with respect to the grafting of molybdenum complexes on the surfaces of solid supports to obtain heterogeneous oxidation catalysts.
Synthesis and Characterization of the Monomeric Sterically Encumbered Diaryls E{C6H3‐2,6‐(C6H3‐2,6‐Pri2)2}2 (E = Ge, Sn, or Pb)
Authors: Spikes Geoffrey H. , Peng Yang , Fettinger James C. , Power Philip P. 
Published: May 2006

AbstractThe reaction of two equivalents of LiC6H3‐2,6‐(C6H3‐2,6‐Pri2)2 with GeCl2·dioxane, SnCl2 or PbBr2 in a diethyl ether solution resulted in the isolation of the monomeric σ‐bonded diaryl tetrylene series E{C6H3‐2,6‐(C6H3‐2,6‐Pri2)2}2 (E = Ge (1), Sn (2), or Pb(3)). Compounds 1‐3 are highly sterically congested blue crystalline solids, which possess V‐shaped structures and wide interligand bond angles. The solid state structures of 1‐3 were determined by single‐crystal X‐ray methods while their solution structures were investigated by UV spectroscopy and in the cases of 2 and 3, respectively, by 119Sn and 207Pb NMR spectroscopy. The series 1‐3 constitutes the most sterically crowded examples of σ‐bonded diorgano group 14 derivatives yet isolated and, in contrast to previously reported: ER2 species, the C‐E‐C angles increase with increasing atomic number.
Nitridorhenium(V) Complexes with 1,3‐Dialkyl‐4,5‐dimethylimidazole‐2‐ylidenes
Authors: Braband Henrik , Oehlke Elisabeth , Abram Ulrich 
Published: May 2006

AbstractThe nitridorhenium(V) complexes [ReNCl2(PR2Ph)3] (R = Me, Et) react with the N‐heterocyclic carbenes (NHC) 1,3‐diethyl‐4,5‐dimethylimidazole‐5‐ylidene (LEt) or 1,3,4,5‐tetramethylimidazole‐2‐ylidene (LMe) in absolutely dry THF under complete replacement of the equatorial coordination sphere. The resulting [ReNCl(LR)4]+ complexes (LR = LMe, LEt) are moderately stable as solids and in solution, but decompose in hot methanol under formation of [ReO2(LR)4]+ complexes. With 1,3‐diisopropyl‐4,5‐dimethylimidazole‐5‐ylidene (Li‐Pr), the loss of the nitrido ligand and the formation of a dioxo species is more rapid and no nitridorhenium intermediate could be isolated.The Re‐C bond lengths in [ReNCl(LEt)4]Cl of approximately 2.195Å are relatively long and indicate mainly σ‐bonding in the electron‐deficient d2 system under study.The hydrolysis of the nitrido complexes proceeds via the formation of [ReO3N]2− anions as could be verified by the isolation and structural characterization of the intermediates [{ReN(PMe2Ph)3}{ReO3N}]2 and [{ReN(OH2)(LEt)2}2O][ReO3N].
Reactions of Silicon Atoms with Methanol: A Combined Matrix‐Spectroscopic and Density Functional Theory Study
Authors: Maier Günther , Glatthaar Jörg 
Published: May 2006

AbstractThe reaction of silicon atoms with methanol (4) has been studied in an argon matrix at 10 K. In the initial step a triplet n‐adduct T‐5 between a silicon atom and 4 is formed. It cannot be detected directly as long as a low concentration of 4 is used. But T‐5 must be generated since upon simultaneous irradiation during cocondensation methylsilanone (15) is found. Without irradiation T‐5 undergoes immediately O,H insertion and methoxysilylene (S‐7‐c) is isolated, which establishes a photoequilibrium between the s,trans (S‐7‐t) and s,cis form (S‐7‐c). If a high concentration of 4 is applied the silylenes exist as complexes S‐17. The next step needs photochemical activation. Products are dimethoxysilane (3) and (hydroxy)(methoxy)methylsilane (19). The picture becomes even more complicated when deuteromethanol ([D]4) is treated with silicon atoms. In this case the primarily formed n‐adduct ([D]T‐5) is stable under matrix conditions. As long as a low concentration is applied, the subsequent step has to be induced by long wavelength irradiation and leads – different from the undeuterated case – to O,CH3 insertion, giving (hydroxy)methylsilylenes ([D]S‐11‐c) and ([D]S‐11‐t). If a high concentration is used O,D insertion is preferred instead and even without irradiation the first observable products are methanol‐solvated methoxysilylenes ([D2]S‐17‐c) and ([D2]S‐17‐t). Subsequent irradiation of complexes [D2]S‐17 gives in accordance with the protonated series a mixture of [D2]3 and [D2]19. Our goal, to find a way to dimethylsilanediol ([D2]2), was finally reached by preparing silylenes [D]S‐11 in a diluted matrix, its specific solvation with [D]4 and final irradiation of complexes [D2]S‐18. The structural elucidation of all new species is based on the comparison of the experimental observations with density functional theory calculations. Upon cocondensation of silicon atoms with pure methanol at 77 K dimethoxysilane (3) and 1,1,2‐trimethoxydisilane (25) are produced. The also present methoxysilanes 22‐24 have to be regarded as secondary products of 3.
Germanium(II)‐, Zinn(II)‐ und Blei(II)‐Derivate des polycyclischen Alumosiloxans [Ph2SiO]8[Al(O)OH]4
Authors: Veith Michael , Hreleva Hinka , Gasthauer Matthias , Rammo Andreas , Huch Volker 
Published: May 2006

AbstractGermanium(II)‐, Tin(II)‐ and Lead(II)‐Derivatives of the polycyclic Alumosiloxane [Ph2SiO]8[Al(O)OH]4Five new derivatives of the polycyclic alumosiloxane [Ph2SiO]8[Al(O)OH]4 have been synthesized by replacement of the protic hydrogen atoms on the hydroxy‐groups attached to the aluminium atoms by the divalent group 14 elements germanium, tin and lead. The compounds can be divided in those with one metal atom per alumosiloxane moiety, [Ph2SiO]8[Al(O)OH]2[AlO2]M (M=Ge, Sn), and those with complete substitution of the protic hydrogen atoms by metal atoms like [Ph2SiO]8[AlO2]4M2 (M= Sn, Pb). Always one element of the series Ge, Sn, Pb is missing in the two types of compounds. Crystal structure analyses of [Ph2SiO]8[Al(O)OH]2[AlO2]2M · 2 C4H8O2 (M= Ge (1), Sn (2a)), [Ph2SiO]8[Al(O)OH]2[AlO2]2Sn · 2 THF (2b) and [Ph2SiO]8[AlO2]4M2 (M= Sn (3), Pb (4)) have been performed elucidating either polycyclic basket‐type (1, 2a, 2b) or closed polyhedral structures (3, 4).
Efficient Synthesis and Properties of Single‐Crystalline [SnTe4]4− Salts
Authors: Ruzin Eugen , Kracke Andreas , Dehnen Stefanie 
Published: May 2006

AbstractSingle‐crystalline K+, Rb+, and Cs+ salts of the ortho‐tellurostannate anion have been prepared by a very efficient fusing/extraction/evaporation method. The resulting compounds with the general composition [A4(H2O)n][SnTe4] can be transferred into mixed H2O/en solvates by solving the hydrates in 1,2‐diaminoethane (en) and ensuing layering by toluene. A mixed Rb+/Ba2+ salt results from a partial cation exchange of the Rb+ hydrate phase in solution. All hydrates react to polytellurides when exposed to air and represent useful starting materials for the synthesis of transition metal complexes with [SnTe4]4− groups as binary main group elemental ligands. [K4(H2O)0.5][SnTe4] (1), [Rb4(H2O)2][SnTe4] (2), [Cs4(H2O)2][SnTe4] (3), [K4(H2O)(en)][SnTe4] (4), [Rb4(H2O)0.67(en)0.33][SnTe4] (5), [Cs4(H2O)0.5(en)0.5][SnTe4] (6), and [Rb2Ba(H2O)11][SnTe4] (7) were characterized by means of X‐ray diffractometry and optical absorption spectroscopy.
Lens‐anomalies and other ophthalmic findings in a group of closely‐related angola lions (Panthera leo bleyenberghi)
Authors: Steinmetz Andrea , Eulenberger Klaus , Thielebein Jens , Buschatz Sarah , Bernhard Andreas , Wilsdorf Albrecht , Ofri Ron 
Published: May 2006

AbstractAfter the diagnosis of bilateral, immature, nuclear, and posterior cortical cataracts in one Angola lioness, and because of the possible implications of the cataracts for a breeding program, complete ophthalmic examinations on a group of related adult Angola lions and their offspring were carried out. Five adult lions, ranging in age from 1.5–5.5 years, and five lion cubs were studied clinically. The examination included slit‐lamp biomicroscopy, indirect ophthalmoscopy, and photography. The eyes of three of the offspring were submitted for histopathologic examination and examined by light microscopy. The most significant findings were cataracts of various stages, which were observed in four adult lions and one male cub. Mild lenticular abnormalities were noted in the histopathologic examination of the lion cubs' eyes. Additional ophthalmic findings, of lesser clinical consequence, were also noted. This breeding program would benefit from further investigation by animal nutritionists and geneticists, and the animals in this group should undergo periodic ophthalmologic examinations. Zoo Biol 0:1–7, 2006. © 2006 Wiley‐Liss, Inc.