bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and validation of an inductively coupled plasma mass spectrometry method for quantification of levothyroxine in dissolution studies
Authors: Pabla Dimple , Akhlaghi Fatemeh , Ahmed Aftab , Zia Hossein 
Published: March 2008

AbstractA simple, sensitive and reproducible inductively coupled plasma mass spectrometry (ICP‐MS) method for the direct determination of levothyroxine (T4), based on the analysis of iodide content, in aqueous media was developed. The sample preparation consisted of addition of antimony, as the internal standard, and dilution with a 0.5% ammonia solution. The analytes were quantified at m/z 126.90 and 120.90 for iodide and antimony, respectively. The assay was linear in the concentration range of 0.1–50 ng/mL for iodide and 0.3–100 ng/mL for T4. The method was precise and accurate with lower limits of quantification (LLOQs) of 0.1 ng/mL for iodide and 0.3 ng/mL for T4. The inter‐day accuracy was >94% for both analytes and the coefficient of variation (%CV) was less than 5%. The method has successfully been used for dissolution studies of T4 formulations and holds immense promise as a simple, precise and sensitive analytical technique for T4 concentration determination in in vitro studies. Copyright © 2008 John Wiley & Sons, Ltd.
Assessing the stable carbon isotopic composition of intercellular CO2 in a CAM plant using gas chromatography‐combustion‐isotope ratio mass spectrometry
Authors: Nogués Salvador , Aranjuelo Iker , Pardo Antoni , Azcón‐Bieto Joaquim 
Published: March 2008

AbstractMost of the literature focused on internal CO2 (Ci) determinations in plants has used indirect methods based on gas‐exchange estimations. We have developed a new method based on the capture of internal air gas samples and their analysis by gas chromatography‐combustion‐isotope ratio mass spectrometry (GC‐C‐IRMS). This method provided a direct measure of intercellular CO2 concentrations combined with stable carbon isotopic composition in O. ficus‐indica plants. Plants were grown at both ambient and elevated CO2 concentration. During the day period, when the stomata are closed, the Ci was high and was very 13C‐enriched in both ambient and elevated CO2‐grown plants, reflecting Rubisco's fractionation (this plant enzyme has been shown to discriminate by 29‰, in vitro, against 13CO2). Other enzyme fractionations involved in C metabolism in plants, such as carbonic anhydrase, could also be playing an important role in the diurnal δ13C enrichment of the Ci. During the night, when stomata are open, Ci concentrations were higher in elevated (and the corresponding δ13C values were more 13C‐depleted) than in ambient CO2‐grown plants. Copyright © 2008 John Wiley & Sons, Ltd.
Serum biomarker profiling by solid‐phase extraction with particle‐embedded micro tips and matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Navare Arti , Zhou Manshui , McDonald John , Noriega Fernando G. , Sullards M. Cameron , Fernandez Facundo M. 
Published: March 2008

AbstractOne of the main challenges in high‐throughput serum profiling by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) is the development of proteome fractionation approaches that allow the acquisition of reproducible profiles with a maximum number of spectral features and minimum interferences from biological matrices. This study evaluates a new class of solid‐phase extraction (SPE) pipette tips embedded with different chromatographic media for fractionation of model protein digests and serum samples. The materials embedded include strong anion exchange (SAX), weak cation exchange (WCX), C18, C8, C4, immobilized metal affinity chromatography (IMAC) and zirconium dioxide particles. Simple and rapid serum proteome profiling protocols based on these SPE micro tips are described and tested using a variety of MALDI matrices. We show that different types of particle‐embedded SPE micro tips provide complementary information in terms of the spectral features detected for β‐casein digests and control human serum samples. The effect of different sample pretreatments, such as serum dilution and ultrafiltration using molecular weight cut‐off membranes, and the reproducibility observed for replicate experiments, are also evaluated. The results demonstrate the usefulness of these simple SPE tips combined with offline MALDI‐TOF MS for obtaining information‐rich serum profiles, resulting in a robust, versatile and reproducible open‐source platform for serum biomarker discovery. Copyright © 2008 John Wiley & Sons, Ltd.
Whole‐cell matrix‐assisted laser desorption/ionization mass spectrometry for rapid identification of bacteriocin/lantibiotic‐producing bacteria
Authors: Stein Torsten 
Published: March 2008

AbstractThe potential of whole‐cell matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry (MS) for the discovery of microorganisms that produce lantibiotics and/or bacteriocins in the mass range 3–5 kDa is demonstrated. Cells of the antibiotic‐producing model strain Bacillus subtilis ATCC 6633 were grown on Landy agar plates, and prepared with a 9:1 mixture of 2,5‐dihydroxybenzoic acid and 2‐hydroxy‐5‐methoxybenzoic acid (DHBs) as matrix using the bottom‐layer method. Time‐course analyses showed that cells grown for 1–2 days on agar plates gave the best results in terms of intensity of the bacteriocin/lantibiotic signals. Even after storage of matrix‐crystal‐embedded cells for several days high‐resolution spectra (>10 000) could be obtained. To verify the applicability of this technique, different Bacillus wild‐type and gene deletion mutant cells were analyzed. In most of the cases the known antibiotic phenotype of the producer could be corroborated by whole‐cell MALDI‐TOFMS, particularly for the lantibiotics subtilin and ericin. The preparation recipe for whole‐cell analysis by MALDI‐TOF was also highly sensitive for hydrophobic lipopeptide antibiotics like surfactin, mycosubtilin, fengycin, and bacillomycin in the lower mass range (1–1.5 kDa). Copyright © 2008 John Wiley & Sons, Ltd.
Dip Pen Nanolithography®: A “Desktop Nanofab™” Approach Using High‐Throughput Flexible Nanopatterning
Authors: Haaheim Jason , Nafday Omkar A. 
Published: March 2008

AbstractThe ability to perform controllable nanopatterning with a broad range of “inks” at ambient conditions is a key aspect of the dip pen nanolithography® (DPN®) technique. The traditional ink system to demonstrate DPN is n‐alkanethiols on a gold substrate, but the DPN method has found numerous other applications since. This article is meant to outline recent advances in the DPN toolkit, both in terms of research and patterning technology, and to discuss applications of DPN as a viable nanofabrication method. We will summarize new DPN developments, and introduce our concept of the “Desktop Nanofab.” In addition, we outline our efforts to commercialize DPN as a viable nanofabrication technique by demonstrating massively parallel nanopatterning with the 55,000 tip 2D nano PrintArray™. This demonstrates our ability to overcome the serial nature of DPN patterning and enable high‐throughput nanofabrication. SCANNING 30: 000–000, 2008. © 2008 Wiley Periodicals, Inc.
A Bayesian hierarchical model for the estimation of two incomplete surveillance data sets
Authors: Buenconsejo Joan , Fish Durland , Childs James E. , Holford Theodore R. 
Published: March 2008

AbstractA model‐based approach to analyze two incomplete disease surveillance datasets is described. Such data typically consist of case counts, each originating from a specific geographical area. A Bayesian hierarchical model is proposed for estimating the total number of cases with disease while simultaneously adjusting for spatial variation. This approach explicitly accounts for model uncertainty and can make use of covariates.The method is applied to two surveillance datasets maintained by the Centers for Disease Control and Prevention on Rocky Mountain spotted fever (RMSF). An inference is drawn using Markov Chain Monte Carlo simulation techniques in a fully Bayesian framework. The central feature of the model is the ability to calculate and estimate the total number of cases and disease incidence for geographical regions where RMSF is endemic.The information generated by this model could significantly reduce the public health impact of RMSF and other vector‐borne zoonoses, as well as other infectious or chronic diseases, by improving knowledge of the spatial distribution of disease risk of public health officials and medical practitioners. More accurate information on populations at high risk would focus attention and resources on specific areas, thereby reducing the morbidity and mortality caused by some of the preventable and treatable diseases. Copyright © 2008 John Wiley & Sons, Ltd.
College students' perceptions of the theory of evolution
Authors: Hokayem Hayat , BouJaoude Saouma 
Published: March 2008

AbstractAlthough a well‐corroborated scientific theory, the theory of evolution has continued to cause dilemmas for some individuals who have not easily been able to accommodate the concepts of this theory within their “cognitive culture.” The reason lies in the overlap of some ideas that the theory advocates with other social, epistemological, and religious beliefs. This study describes how 11 college biology students who completed a course on the theory of evolution perceive the relationship among their epistemological beliefs about science, their beliefs about religion, and their perception of nature and causality and their position regarding the theory of evolution. It also compares the different positions of the students to that of the course instructor. Questionnaires and semistructured interviews were used to collect data. Qualitative methods were used to analyze the data and identify the various positions of the students and course instructor. The students' positions ranged from complete acceptance to complete rejection of the theory of evolution. The results suggest that students' personal beliefs should not be dismissed or underestimated when teaching the theory of evolution. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 395–419, 2008
The Vercelli Gospels laid open: an investigation into the inks used to write the oldest Gospels in Latin
Authors: Aceto Maurizio , Agostino Angelo , Boccaleri Enrico , Garlanda Anna Cerutti 
Published: March 2008

AbstractAn ancient religious manuscript datable to the 4th century A.D., the Codex Eusebii Evangeliorum or Vercelli Gospels, has been analysed by portable Raman and x‐ray fluorescence (XRF) spectrometry. The manuscript belongs to the Cathedral Treasure Museum of Vercelli (Italy) and is reputed to be the oldest existent copy of the Gospels written in Latin, being therefore of particular relevance to biblical scholars. Red and black inks were characterised: minium and cinnabar were identified in red text, and carbon black and metal gallate in black text. Moreover, XRF spectrometry allowed discrimination of black inks with similar composition on the basis of metal impurities. The black ink was found to be of the iron‐gall type, thus resulting in the oldest occurrence of the use of this kind of ink in Western manuscripts and allowing to date its introduction at least back to the 4th century A.D.; moreover, the hypothesis that a few pages had been written in a later time has been verified on the basis of differences in inks' composition. Copyright © 2008 John Wiley & Sons, Ltd.
Copper(I) π‐Complexes with 2‐Butyne‐1,4‐diol. Synthesis and Crystal Structure of Na[CuCl2(HOCH2C≡CCH2OH)]·2H2O
Authors: Slyvka Yu. , Kinzhybalo V. , Lis T. , Mykhalitchko B. , Mys'kiv M. 
Published: March 2008

AbstractCrystals of anionic Na[CuCl2(HOCH2C≡CCH2OH)]·2H2O π‐complex have been synthesized by interaction of 2‐butyne‐1,4‐diol with CuCl in a concentrated aqueous NaCl solution and characterized by X‐ray diffraction at 100 K. The crystals are triclinic: space group $P{\bar 1}$, a = 7.142(3), b = 7.703(3), c = 10.425(4) Å, α = 105.60(3), β = 99.49(3), γ = 110.43(3)°, V = 495.9(4) Å3, Z = 2, R = 0.0203 for 3496 reflections. The structure is built of discrete [CuCl2(HOCH2C≡CCH2OH)]− anionic stacks and polymeric $\rm [Na^{+}(H_{2}O)_{2}]_{\infty}$ cations among the stacks. The CuI atom adopts trigonal planar coordination of two Cl− anions and the C≡C bond of 2‐butyne‐1,4‐diol, Cu–(C≡C) distance is equal to 1.903(3) Å. Na+ cations environment is octahedral and consists of O and Cl atoms. The crystal packing is governed by strong hydrogen bonds of O–H···Cl and O–H···O types.
Metal Derivatives of 1,3‐Imidazolidine‐2‐thione with Divalent d10 Metal Ions (Zn–Hg) : Synthesis and Structures
Authors: Lobana Tarlok S. , Sharma Renu , Sharma Rekha , Sultana Razia , Butcher R. J. 
Published: March 2008

AbstractReactions of divalent Zn‐Hg metal ions with 1,3‐imidazolidine‐2‐thione (imdtH2) in 1 : 2 molar ratio have formed monomeric complexes, [Zn(η1‐S‐imdtH2)2(OAc)2] (1), [Cd((η1‐SimdtH2)2I2] (2), [Cd(η1‐S‐imdtH2)2Br2] (3), and [Hg(η1‐S‐imdtH2)2I2] (4). Complexes 1–4, have been characterized by elemental analysis (C, H, N), spectroscopy (IR, 1H, NMR) and x‐ray crystallography (1‐4). Hydrogen bonding between oxygen of acetate and imino hydrogen of ligand, {N(2)–H(2C)···O(2)#} in 1, ring CH and imino hydrogen, {C(2A)–H(2A)···Br(2)#} in 3 have formed H‐bonded dimers. Similarly, the interactions between molecular units of complexes 2 and 4 have yielded 2D polymers. The polymerization occurs via intermolecular interactions between thione sulfur and imino hydrogen, {N(2)–H(2)···S(1)#}, imino hydrogen and the iodine atom, {NH(1)···I(2)#} in 2 and imino hydrogen – iodine atom {N(2A)–H(2A)···I(2)} and I···I interaction in 4. Crystal data: [Zn(η1‐S‐imdtH2)2(OAc)2] (1), C10H18N4O4S2Zn, orthorhombic, Pbcn, a = 9.3854(7) Å, b = 12.4647(10) Å, c = 13.2263(11) Å; V = 1547.3(2) Å3, Z = 4, R = 0.0280 [Cd((η1‐S‐imdtH2)2I2] (2), C6H12CdI2N4S2, orthorhombic, Pnma, a = 13.8487(10) Å, b = 14.4232(11) Å, c = 7.0659(5) Å; Z = 4, V = 1411.36(18) Å3, R = 0.0186.
Unexpected Coordination Modes of the Tris(imidazolyl)phosphane Oxide Ligand 4‐TIPOiPr in the Chloro Complexes of Zinc, Cobalt and Nickel
Authors: Kunz Peter C. , Zribi Alya , Frank Walter , Kläui Wolfgang 
Published: March 2008

AbstractThe coordination chemistry of the water soluble phosphane oxide ligand tris[2‐isopropylimidazol‐4(5)‐yl]phosphane oxide, 4‐TIPOiPr, has been explored. A variety of 3d‐metal halide complexes have been prepared and the crystal structures of the solvates [(4‐TIPOiPr)ZnCl2]·MeOH·1/2dioxane (1·MeOH·1/2dioxane), [(4‐TIPOiPr)CoCl2]·H2O·2dioxane (2·H2O·2dioxane) and [(4‐TIPOiPr)2Ni(MeOH)2]Cl2·2MeOH (3·2MeOH) have been determined. All three structures show unprecedented coordination modes of the 4‐TIPOiPr ligand. Both zinc and cobalt complexes are coordinated in a bidentate κ2N fashion, whereas the nickel atom is coordinated by two ligands in a κN,O mode using one imidazolyl substituent and the P=O oxygen atom.
Synthese und Untersuchung von kohlenstoff‐ und stickstoffzentrierten (Z) trigonal‐prismatischen Wolframclustern des Formeltyps A[W6ZCl18]
Authors: Weisser Martina , Burgert Ralf , Schnöckel Hansgeorg , Meyer H.‐Jürgen 
Published: March 2008

AbstractSynthesis and Characterization of Carbon‐ and Nitrogen‐Centered (Z) Trigonal Prismatic Tungsten Clusters of the Formula Type A[W6ZCl18]Solid state reactions of tungsten(IV) chloride and carbodiimides (cyanamides) of lithium, sodium, calcium and silver yielded black crystalline powders of centered (Z) trigonal‐prismatic tungsten cluster compounds having the general formula A[W6ZCl18] with A = Li, Na, Ca, Ag and Z = C, N. Crystal structures of the corresponding compounds were investigated by powder and single‐crystal X‐ray diffraction. The nature of the central atom was studied by mass spectrometry and nuclear magnetic resonance spectrometry. It turned out that the central atom can be C (in the case of the lithium and sodium compound) or N (in the case of the sodium and calcium compound).
Nickel(II) Complexes with a Hydroxyl Pendant‐Armed Macrocyclic Ligand: Synthesis, Characterization, and Crystal Structures
Authors: Hosseini‐Yazdi Seyed Abolfazl , Khandar Ali Akbar , Azizi Hashem 
Published: March 2008

AbstractThe reactions of different nickel(II) salts with a mixed‐donor macrocyclic ligand L (6,7,8,9,10,11,18,19‐octahydro‐5H, 17H‐dibenzo[f,o][1,5,9,13] dioxadiazacyclohexadecin‐18‐ol), potentially pentadentate N2O3 donor sets containing one pendant alcohol function have been investigated. The physical properties and the chemical structures of 1:1 (metal:ligand) NiLX2 (X = Cl−, Br−, NO3−, ClO4−) complexes have been characterized by using IR, UV‐Vis spectroscopy and conductance measurements. The X‐ray determination have been employed to probe the nature of the respective complexes in solid state. The nickel atom in [NiL(NO3)]NO3·0.5H2O complex is six‐coordinate with a distorted octahedral coordination in which the all N2O3 donor atoms are coordinated to the nickel atom. The coordination sphere is completed by a nitrate anion. In contrast to the above nickel complex, in [NiLCl2] complex the pendant hydroxyl arm of macrocycle remains uncoordinated and ligand acts as tetradentate N2O2 donor atoms. The coordination sphere is completed by two chloride anions and the nickel atom is six‐coordinate with a distorted octahedral coordination.
Pertechnetyl Fluorosulfate, [TcO3]+[SO3F]−
Authors: Supeł Joanna , Hagenbach Adelheid , Abram U. , Seppelt Konrad 
Published: March 2008

AbstractA one step synthesis of [TcO3]+[SO3F]− is reported. The compound is volatile at room temperature and has according to calculations a tetrahedral coordination around Tc and a monodentate SO3F group. In the solid state the [SO3F]− anion bridges three [TcO3]+ cations, and vice versa. Space group P21/c, Z = 4, lattice dimensions at 173 K: a = 695.4(11), b = 808.6(12), c = 893.3(14) pm, β = 97.36(8)°.
Syntheses, Structures and Luminescent Properties of Metal Complexes with Imidazole‐Containing Polyamine Ligand
Authors: Lu Yi , Lu Xi‐Hong , Huang Yong‐Qing , Okamura Taka‐aki , Kong Ling‐Yan , Sun Wei‐Yin , Ueyama Norikazu 
Published: March 2008

AbstractFour novel metal complexes [Cd(L)Cl](BF4)·H2O (1), [Cd(L)Br]2[CdBr4]·2H2O (2), [Cu(L)Br]Br (3), and [Cu(L)](NO3)2 (4) were prepared by the reactions of ligand N1‐(2‐aminoethyl)‐N1‐(2‐imidazolethyl)‐ethane‐1,2‐diamine (L) with metal salts under different reaction conditions. All of these complexes exhibit 1D chains, but different structures. The results showed that the pH value of the reaction solution and counter ions have remarkable impact on the structure of the complexes. Furthermore, complexes 1 and 2 represent fluorescence properties in the solid state at room temperature.
Self‐Assembly of Polyoxometalate‐Supported Ln‐H nydroxo/Oxo Clusters with 1D Extended Structure: [LnIII(H2O)7Cr(OH)6Mo6O18]n·4nH2O (Ln = Ce, Sm, Eu)
Authors: Shi Dong‐Mei , Ma Feng‐Xia , Zhang Chun‐Jing , Lu Sheng , Chen Ya‐Guang 
Published: March 2008

AbstractThree novel polyoxometalate compounds consisting of Anderson‐type anions and trivalent lanthanide cations, [Ln(H2O)7Cr(OH)6Mo6O18]n·4nH2O (Ln = Ce 1; Sm 2; Eu 3), have been synthesized in aqueous solution and characterized by single crystal X‐ray diffraction, elemental analyses, IR spectra, and TG analyses. Single crystal X‐ray diffractions reveal that the structures of the 1:1 composite compound formed by the heteropolyanion [Cr(OH)6Mo6O18]3− as the building unit and the [Ln(H2O)7]3+ complex fragment as the linker, which exhibit a type of zig‐zag chain with alternating cations and anions through the Mo‐Ot′‐Ln‐Ot′‐Mo linkage in the crystal. The magnetic properties of 1−3 have been studied by measuring their magnetic susceptibility over the temperature range of 2‐300 K. The UV‐vis spectra of 1 give the Mo‐O and CrIII‐O charge transfer transitions at 203 and 543 nm, respectively. In addition, the fluorescent characteristic transition of the Eu3+ ions in compound 3 is reported.
Syntheses, Structures and Magnetic Properties of Two Mixed‐Valent Disc‐like Hepta‐nuclear Compounds of [FeIIFeIII6(tea)6](ClO4)2 and [MnII3MnIII4(nmdea)6(N3)6]·CH3OH (tea = N(CH2CH2O)33−, nmdea = CH3N(CH2CH2O)22−)
Authors: Liu Tao , Wang Bing‐Wu , Chen Yi‐Hong , Wang Zhe‐Ming , Gao Song 
Published: March 2008

AbstractTwo mixed‐valent disc‐like hepta‐nuclear compounds of [FeIIFeIII6(tea)6](ClO4)2 (1Fe, tea = N(CH2CH2O)33−) and [MnII3MnIII4(nmdea)6(N3)6]·CH3OH (2Mn, nmdea = CH3N(CH2CH2O)22−) have been synthesized by the reaction of Fe(ClO4)2·6H2O with triethanolamine (H3tea) for the former and reaction of Mn(ClO4)2·6H2O with diethanolamine (H2nmdea) and NaN3 for the later, respectively. 1Fe has the cationic cluster with a planar [FeIIFeIII6] core consisting of one central FeII and six rim FeIII atoms in hexagonal arrangement. The Fe ions are linked by the oxo‐bridges from the alcohol arms in the manner of edge‐sharing of their coordination octahedra. 2Mn is a neutral cluster with a [MnII3MnIII4] core possessing one central MnII atom surrounded by six rim Mn ions, two MnII and four MnIII. The structure is similar to 1Fe but involves six terminal azido ligands, each coordinate one rim Mn ion. 1Fe showed dominant antiferromagnetic interaction within the cluster and long‐range ordering at 2.7 K. The cluster probably has a ground state of low spin of S = 5/2 or 4/2. The long‐range ordering is weak ferromagnetic, showing small hysteresis with a remnant magnetization of 0.3 Nβ and a coercive field of 40 Oe. Moreover, the isofield of lines 1Fe are far from superposition, indicating the presence of significant zero–field splitting. Ferromagnetic interactions are dominant in 2Mn. An intermediate spin ground state 25/2 is observed at low field. In high field of 50 kOe, the energetically lowest state is given by the ms = 31/2 component of the S = 31/2 multiplet due to the Zeeman effect. Despite of the large ground state, no single‐molecule magnet behavior was found above 2 K.
An Unusual Mixed‐Anionic Iodine‐Rich Polyiodide: [Rb(crypt‐2,2,2)]4(I5)2(I8)
Authors: Link Caroline , Pantenburg Ingo , Meyer Gerd 
Published: March 2008

AbstractBlack crystals of [Rb(crypt‐2,2,2)]4(I5)2(I8) were obtained from a dichloromethane/ethanol solution of RbI, I2 and Kryptofix‐2,2,2®. The crystal structure (monoclinic, P21/c (no. 14), a = 1250.1(1), b = 2555.2(2), c = 2313.4(3) pm, β = 121.45(1)°, V = 6309.9(11)·106 pm3, Z = 2) consists of [Rb(crypt‐2,2,2)]+ cations leaving three‐dimensional channels for the V‐shaped (I5)− and Z‐shaped (I8)2− anions which are isolated from each other.
Reference Values for the B‐X Bond Lengths of BI3 and BBr3
Authors: Santiso‐Quiñones G. , Krossing I. 
Published: March 2008

AbstractHigh‐resolution X‐ray analysis of BI3 and BBr3 single crystals as well as high‐level theoretical calculations agree on accurate but long B‐X bond distances that should be used as future reference to account for their structure, bonding and reactivity.