bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of the lipophilic antipsychotic drug ziprasidone in rat plasma and brain tissue using liquid chromatography–tandem mass spectrometry
Authors: Zhang Guodong , Terry Alvin V. , Bartlett Michael G. 
Published: March 2008

AbstractA simple, sensitive and robust liquid chromatography/electrospray ionization tandem mass spectrometry (LCESI‐MS/MS) method with low matrix effects was developed and validated for the quantification of the lipophilic antipsychotic ziprasidone from rat plasma and brain tissue. Ziprasidone was extracted from rat plasma and brain homogenate using a single‐step liquid–liquid extraction. Ziprasidone was separated on an Agilent Eclipse XDB C8 column (150 × 2.1 mm i.d., 5 µm) column using a mobile phase of acetonitrile–0.02% ammonia in water (pH 7.20 adjusted with formic acid) using gradient elution. Ziprasidone was detected in the positive ion mode using multiple reaction monitoring. The method was validated and the specificity, linearity, lower limit of quantitation (LLOQ), precision, accuracy, recovery, matrix effects and stability were determined. The LLOQ was 0.2 ng/mL for plasma and 0.833 ng/g for brain tissue. The method was linear over the concentration range from 0.2 to 200.0 ng/mL for plasma and 0.833–833.3 ng/g for brain tissue. The correlation coefficient (R2) values were more than 0.996 for both plasma and brain homogenate. The precision and accuracy intra‐day and inter‐day were better than 8.13%. The relative and absolute recovery was above 81.0% and matrix effects were lower than 5.2%. This validated method has been successfully used to quantify the rat plasma and brain tissue concentration of ziprasidone after chronic treatment. Copyright © 2008 John Wiley & Sons, Ltd.
Divalent Carbon(0) Chemistry, Part 1: Parent Compounds
Authors: Tonner Ralf , Frenking Gernot 
Published: March 2008

AbstractQuantum‐chemical calculations with DFT (BP86) and ab initio methods [MP2, SCS‐MP2, CCSD(T)] have been carried out for the molecules C(PH3)2(1), C(PMe3)2(2), C(PPh3)2(3), C(PPh3)(CO) (4), C(CO)2(5), C(NHCH)2(6), C(NHCMe)2(7) (Me2N)2CCC(NMe2)2(8), and NHC (9), where NHC=N‐heterocyclic carbene and NHCMe=N‐methyl‐substituted NHC. The electronic structure in1–9was analyzed with charge‐ and energy‐partitioning methods. The results show that the bonding situations in L2C compounds1–8can be interpreted in terms of donor–acceptor interactions between closed‐shell ligands L and a carbon atom which has two lone‐pair orbitals L→C←L. This holds particularly for the carbodiphosphoranes1–3where L=PR3, which therefore are classified as divalent carbon(0) compounds. The NBO analysis suggests that the best Lewis structures for the carbodicarbenes6and7where L is a NHC ligand have CCC double bonds as in the tetraaminoallene8. However, the Lewis structures of6–8, in which two lone‐pair orbitals at the central carbon atom are enforced, have only a slightly higher residual density. Visual inspection of the frontier orbitals of the latter species reveals their pronounced lone‐pair character, which suggests that even the quasi‐linear tetraaminoallene8is a “masked” divalent carbon(0) compound. This explains the very shallow bending potential of8. The same conclusion is drawn for phosphoranylketene4and for carbon suboxide (5), which according to the bonding analysis have hidden double‐lone‐pair character. The AIM analysis and the EDA calculations support the assignment of carbodiphosphoranes as divalent carbon(0) compounds, while NHC9is characterized as a divalent carbon(II) compound. The L→C(1D) donor–acceptor bonds are roughly twice as strong as the respective L→BH3bond.
Divalent Carbon(0) Chemistry, Part 2: Protonation and Complexes with Main Group and Transition Metal Lewis Acids
Authors: Tonner Ralf , Frenking Gernot 
Published: March 2008

AbstractQuantum‐chemical calculations with DFT (BP86) and ab initio methods (MP2, SCS‐MP2) were carried out for protonated and diprotonated compoundsN‐H+andN‐(H+)2and for the complexesN‐BH3,N‐(BH3)2,N‐CO2,N‐(CO2)2,N‐W(CO)5,N‐Ni(CO)3andN‐Ni(CO)2whereN=C(PH3)2(1), C(PMe3)2(2), C(PPh3)2(3), C(PPh3)(CO) (4), C(CO)2(5), C(NHCH)2(6), C(NHCMe)2(7) (Me2N)2CCC(NMe2)2(8) and NHC (9) (NHCH=N‐heterocyclic carbene, NHCMe=N‐substituted N‐heterocyclic carbene). Compounds1–4and6–9are very strong electron donors, and this is manifested in calculated protonation energies that reach values of up to 300 kcal mol−1for7and in very high bond strengths of the donor–acceptor complexes. The electronic structure of the compounds was analyzed with charge‐ and energy‐partitioning methods. The calculations show that the experimentally known compounds2–5and8chemically behave like molecules L2C which have two L→C donor–acceptor bonds and a carbon atom with two electron lone pairs. The behavior is not directly obvious when the linear structures of carbon suboxide and tetraaminoallenes are considered. They only come to the fore on reaction with strong electron‐pair acceptors. The calculations predict that single and double protonation of5and8take place at the central carbon atom, where the negative charge increases upon subsequent protonation. The hitherto experimentally unknown carbodicarbenes6and7are predicted to be even stronger Lewis bases than the carbodiphosphoranes1–3.
Mechanism of Charge Separation in DNA by Hole Transfer through Consecutive Adenines
Authors: Kawai Kiyohiko , Osakada Yasuko , Fujitsuka Mamoru , Majima Tetsuro 
Published: March 2008

AbstractTo investigate the mechanism of charge separation in DNA with consecutive adenines adjacent to a photosensitizer (Sens), a series of naphthalimide (NI) and 5‐bromouracil (brU)‐modified DNAs were prepared, and the quantum yields of formation of the charge‐separated states (Φ) upon photo‐excitation of the Sens NI in DNA were measured. The Φ was modulated by the incorporation site of brU, which changes the oxidation potential of its complementary A through hydrogen bonding and the hole‐transfer rates between adenines. The results were interpreted as charge separation by means of the initial charge transfer between NI in the singlet excited state and the second‐ and third‐nearest adenine to the NI. In addition, the oxidation of the A nearest to NI leads to the rapid charge recombination within a contact ion pair. This suggests that the charge‐separation process can be refined to maximize the Φ by putting a redox‐inactive spacer base pair between a photosensitizer and an A–T stretch.
Experimental and numerical investigation of vortex‐induced flame propagation in a biomass furnace with tangential over fire registers
Authors: Shanmukharadhya K. S. , Sudhakar K. G. 
Published: March 2008

AbstractThe tangentially fired furnaces have evolved because of rapid contacting of the fuel and air flame impingement, and the increased particulate residence time due to vortex motion. Tangentially fired units have a good record in being able to meet emission regulation on NOx as a result of their flexibility and the ability to control the heat release rate. Yet, the flow inside the tangentially fired furnaces is known to have its own peculiar aerodynamics; it is quite complicated in such a way that it is not easy to reach a satisfactory model to describe it. The drawbacks with the traditional tangentially fired furnaces are burner velocities. Low velocities are not suitable for fuels having high volatile contents, as ignition occurs in or near the burner causing slugging and distortion problems. Very high velocities on the other hand are undesirable as fuel particles can centrifuge out of the main combustion zone as unburnt carbon. The test boiler used in this work has tangential over fire registers located in the side walls, which are directed to form an imaginary circle at the centre to aid the suspension burning. The vortex formed by these jets, is then induced by the under grate air in reaching the higher levels in the furnace. In the test furnace, the fuel is not coming along with the tangential over fire air, but enters the furnace through the bagasse spreaders and carried by the distributor air. The combustion of bagasse and the propagation of the flame within the furnace are influenced by the tangential over fire air and the under grate air. In the present work, the furnace is simulated and analyzed for the propagation of flame and the patterns at various heights of the furnace supported by the measurements.
Modélisation de la cinétique de biodégradation de phénol par granules aérobies
Authors: Calvario‐Rivera Claudia , Vázquez‐Rodríguez Gabriela A. , Roux Gilles , Waissman‐Vilanova Julio 
Published: March 2008

AbstractCe travail est consacré à la modélisation de la cinétique de biodégradation de phénol par granules aérobies. Ceux‐ci ont été obtenus à partir de la culture à alimentation séquentielle d'un surnageant de boues activées sur une eau usée synthétique ; puis ils ont été acclimatés au phénol (100 mg/L). La biodégradation de différentes concentrations de phénol (40–1112 mg/L) a été étudiée en fioles agitées ensemencées avec des granules acclimatés. Un modèle de type Haldane a été sélectionné, qui permet de décrire de manière adéquate l'évolution de la concentration de phénol avec un seul jeu de paramètres. Ce modèle pourrait permettre de mieux comprendre la biodégradation de molécules toxiques telles que le phénol dans des réacteurs granulaires aérobies.
Alkali Metal (Li+–Cs+) Salts with Hexafluorochromate(V), Hexafluorochromate(IV), Pentafluorochromate(IV), and Undecafluorodichromate(IV) Anions
Authors: Mazej Zoran , Goreshnik Evgeny 
Published: March 2008

AbstractThe compounds ACrF6 (A = Li–Cs) were prepared by photochemical reactions of AF/CrF3 mixtures in anhydrous HF with elemental F2 at ambient temperature. The crystal structures of compounds ACrF6 (A = K–Cs) are analogous to that of KOsF6, and NaCrF6 exhibits polymorphism. The trigonal phase (II) can be classified to have the well‐known LiSbF6 type of structure, while the crystal structure of the orthorhombic modification (I) appears to be a new structure‐type. Thermal decomposition of the ACrF6 salts produce ACrF5(A = Rb, Cs), ACrF5/A2CrF6 (A = K), or A2CrF6 (A = Li, Na). These compounds undergo partial solvolysis in anhydrous HF with precipitation of CrF4. From the remaining solutions of the [CrF6]2– anions and dissolved AF (A = Li–Cs), single crystals of ACrF5 (A = K–Cs), A2CrF6·2HF (A = Na, K), A2CrF6·4HF (A = Rb, Cs), Li2CrF6, and K3Cr2F11·2HF were grown, and their crystal structures determined. The main structural feature of the ACrF5 compounds is the infinite zig‐zag [CrF5]nn– chain of distorted [CrF6] octahedra joined by cis vertices. The crystal structures of A2CrF6·2HF (A = Na, K) and A2CrF6·4HF (A = Rb, Cs) consist of distorted [CrF6]2– octahedra involved in moderate to strong hydrogen bonding with HF molecules, while two A+ cations compensate the negative charge of each octahedron. In Na2CrF6·2HF, two neighboring HF molecules are involved in moderate to strong hydrogen bonding with each other. (HF)2 dimers with a parallelogram structure are formed. The mutual interactions in the crystal structure of K2CrF6·2HF differ from those found in Na2CrF6·2HF. In the former, each HF molecule interacts with the [CrF6]2– anion and three K+ cations. A2CrF6·4HF compounds of Rb and Cs are isostructural. Their structures consist of A+ cations and [CrF6]2– anions involved in hydrogen bonding with two sets of HF molecules in the trans position. The crystal structure of K3Cr2F11·2HF reveals a rare case of the [M2F11]3– anion. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Tetrakis(trimethylsilyl)cyclobutadiene Dianion Alkaline Earth Metal Salts: New Members of the 6π‐Electron Aromatics Family
Authors: Takanashi Kazunori , Inatomi Akira , Lee Vladimir Ya. , Nakamoto Masaaki , Ichinohe Masaaki , Sekiguchi Akira 
Published: March 2008

AbstractThe magnesium and calcium salts of the tetrakis(trimethylsilyl)cyclobutadiene dianion, [Mg(thf)3]2+[(Me3Si)4C4]2– (2a) and [Ca(thf)n]2+[(Me3Si)4C4]2– (2b), were synthesized by the reduction of tetrakis(trimethylsilyl)cyclobutadiene [(Me3Si)4C4, 1] with metallic magnesium or calcium, respectively. X‐ray analysis of 2a showed a planar four‐membered ring, featuring a diagnostic η4‐coordination to the magnesium atom and skeletal C–C bond lengths intermediate between those of typical C–C single and C=C double bonds. The structural and spectral features of the cyclobutadiene dianion magnesium salt 2a give evidence for its appreciable aromaticity.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
C‐D‐Glucopyranosyl Derivatives of Tocopherols – Synthesis and Evaluation as Amphiphilic Antioxidants
Authors: He Li , Galland Stéphanie , Dufour Claire , Chen Guo‐Rong , Dangles Olivier , Fenet Bernard , Praly Jean‐Pierre 
Published: March 2008

AbstractTreatment of dimethylhydroquinone dimethyl ethers (ortho and meta isomers) with glycopyranose pentaacetates (D‐gluco, D‐galacto) in the presence of SnCl4 and F3CCO2Ag selectively afforded the corresponding C‐β‐D‐glycosyl derivatives by aromatic electrophilic substitution. Oxidation of the dimethoxybenzene moiety with ceric ammonium nitrate delivered C‐β‐D‐glycosyl‐dimethylbenzoquinones, which were reduced with Na2S2O4 to the corresponding C‐β‐D‐glycosyl‐dimethylhydroquinones. ZnCl2‐catalyzed cyclization either with methylbut‐2‐en‐1‐ol (prenyl alcohol) or with all‐racemic phytol led to acetyl‐protected C‐β‐D‐glycosyl chromanols or C‐β‐D‐glycosyl tocopherols, the sugar residues of which were deacetylated under base catalysis conditions. These new molecules were evaluated as antioxidants in terms of their ability to inhibit the peroxidation of linoleic acid in SDS micelles. The position of the C‐glucosyl moiety on the phenolic nucleus emerges as the critical structural determinant of their activity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Capillary electrophoresis for the detection of PMP22 gene duplication: Study in Mexican patients
Authors: Hernández‐Zamora Edgar , de la Luz Arenas‐Sordo María , Maldonado‐Rodríguez Rogelio 
Published: March 2008

AbstractCharcot‐Marie‐Tooth (CMT) disease is the most common inherited disorder of the human peripheral nerve, with an estimated overall prevalence of 17‐40/10 000 [1]. The typical phenotype presents peroneal muscular atrophy andpes cavus[2]. CMT is usually divided into two large types, about two‐thirds of the patients have CMT type 1 (CMT1), that affects the layer of myelin (demyelination). In type 2 (CMT2) the nerve fibers are affected (axonal). CMT diseases have autosomal dominant, autosomal recessive, and X‐linked inheritance [1]. The most frequent subtype is 1A (CMT1A) with autosomal dominant transmission, secondary in most cases to a tandem duplication of a 1.5 Mb DNA fragment on chromosome 17p11.2‐p12 [4–7]. In this region, the codification of the peripheral myelin protein 22 (PMP22) takes place. The severity of the disease varies among patients, even within the same family, from almost no symptoms to severe foot‐drop and sensory loss. The PMP22 gene has four exons and is regulated by two promoters located toward the extreme 5′. The origin of the duplication that causes the disease is an uneven exchange of the chromatids during the meiosis. This unequal recombination occurs between two regions that limit the PMP22 gene, described as REP places of 24 kb, proximal and distal [3, 4].
Surface engineering of PHBV by covalent collagen immobilization to improve cell compatibility
Authors: Wang Yingjun , Ke Yu , Ren Li , Wu Gang , Chen Xiaofeng , Zhao Qichun 
Published: March 2008

AbstractCovalent immobilization of collagen onto poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) film was achieved to improve its cell compatibility. Amide groups photografted on PHBV films were initially converted into amine groups through Hofmann degradation and collagen was then chemically bonded to amine groups, consequently forming the amide, amine, and collagen‐modified PHBV. The structures of these modified PHBV films were confirmed by ATR‐FTIR, XPS, and SEM analyses. Compared with that of PHBV film, surface wettability of the modified PHBV films enhanced remarkably. In particular, water contact angle of the collagen‐modified PHBV film decreased from 65.0° to 2.1° within 130 s. Sheep chondrocytes cultured on PHBV and modified PHBV films were evaluated by cell adhesion test, MTT assay, and morphological observation under SEM. Results showed that the collagen‐modified PHBV film had better cell adhesion and proliferation than other modified PHBV films and PHBV film. Chondrocytes on the collagen‐modified PHBV film adhered through filopodia, spread by cytoplasmic webbing, and formed cells layer earlier than other modified ones, indicating that the collagen‐modified PHBV is a promising biomaterial for cartilage tissue engineering. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Composite resin degradation products from BisGMA monomer modulate the expression of genes associated with biofilm formation and other virulence factors in Streptococcus mutans
Authors: Singh Jatinderpreet , Khalichi Peyman , Cvitkovitch Dennis G. , Santerre J. Paul 
Published: March 2008

AbstractBacterial microleakage along the tooth/composite resin dental restoration interface contributes to postoperative sensitivity, recurrent caries, and necrosis. Studies have confirmed that enzymes in human saliva degrade composite resin monomers 2,2‐bis [4‐(2‐hydroxy‐3‐methacryloxypropoxy) phenyl] propane (BisGMA) and triethylene glycol dimethacrylate (TEGDMA) to release methacrylic acid (MA), bishydroxypropoxyphenyl propane (Bis‐HPPP), and triethylene glycol (TEG) at levels of 50 μM in vivo. Studies have found that TEGDMA degradation products alter the growth and gene expression of cariogenic Streptococcus mutans. Specifically, TEG was shown to alter S. mutans gene expression levels of gtfB, a known virulence factor, and yfiV, a putative transcriptional regulator of cell‐surface fatty acid genes. The objective of this study was to examine the effect of BisGMA degradation products on the growth and gene expression of S. mutans NG8 cells. Results demonstrated slight inhibition of bacterial growth at Bis‐HPPP concentrations of 1.0 × 102 and 2.5 × 102 μM at pH 5.5. Furthermore, both MA and Bis‐HPPP affected gtfB and yfiV expression in a concentration‐dependent manner. Because BisGMA is universally used across most dental restorative materials, with millions of placement procedures performed annually, these findings are relevant due to the potential influence of resin monomer‐derived biodegradation products on biofilm formation, acid tolerance, and proliferation of S. mutans cells. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Effect of the heating temperature on the corrosion resistance of alkali‐treated titanium
Authors: Krupa D. , Baszkiewicz J. , Mizera J. , Borowski T. , Barcz A. , Sobczak J. W. , Biliński A. , Lewandowska‐Szumieł M. , Wojewódzka M. 
Published: March 2008

AbstractThe paper presents the results of examinations of the corrosion resistance of titanium after its being subjected to the surface modification by the alkali‐ and heat‐treatments. The material examined was commercially pure titanium (grade 2). The samples were soaked in an aqueous 10M NaOH solution at 60°C for 24 h and subsequently heated at 500, 600, or 700°C for 1 h. The chemical composition of the surface layers was determined by X‐ray photoelectron spectroscopy and secondary ion mass spectroscopy. The phases present in the layers were identified by XRD. The corrosion resistance was evaluated by electrochemical methods (Stern's method, potentiodynamic method, and impedance spectroscopy) at a temperature of 37°C after short‐ and long‐time exposures. The 13 h exposure was aimed to allow the corrosion potential to stabilize. The aim of the long‐term exposures was to examine how the corrosion resistance of the modified samples changes during the exposure. Under the conditions prevailing during the experiments, the highest corrosion resistance was achieved with the samples heated at a temperature of 700°C. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Micropatterned hot‐embossed polymeric surfaces influence cell proliferation and alignment
Authors: Moroni Lorenzo , Lee Luke P. 
Published: March 2008

AbstractMicropatterning is a powerful technique to custom‐make and precisely control the surface topography of materials, which is determinant for a better interaction with cells. A modification of conventional micropatterning is proposed here to fabricate textured film from stiff and sticky polymers such as poly(lactide(s)‐co‐glycolide(s)) (PLGA) without the use of supports or solvents. Micropatterned PLGA films with square pits varying in height and channels varying in width were made to study the influence of these topographical parameters on human fibroblasts proliferation, morphology, and alignment. With increasing the square pit height, the cell attachment efficiency increased. After 10 days of culture the micropatterned films supported a significantly higher cell proliferation than smooth films. In particular, cell growth was highly stimulated in 150‐μm‐wide channels. Fibroblasts were spread with a typical spindle shape in all the films. Cell spreading increased with increasing the textured dimensions. A random cell organization was found for smooth and for square pit samples, and a high alignment was observed along the 150‐μm‐wide channels. Smaller and bigger channels did not support substantial cell growth, suggesting a possible “recognition” mechanism of the cells for optimal organization. These findings could be useful in tissue engineering applications where higher proliferation rates and eventual random or unidimensional alignments of cells are desirable. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
SEL1L and HRD1 are involved in the degradation of unassembled secretory Ig‐µ chains
Authors: Cattaneo Monica , Otsu Mieko , Fagioli Claudio , Martino Simone , Lotti Lavinia Vittoria , Sitia Roberto , Biunno Ida 
Published: March 2008

AbstractWhen expressed in the absence of light chains, secretory Ig‐µ chains (µs) undergo endoplasmic reticulum associated degradation (ERAD). This process involves the recognition of terminally misfolded or unassembled molecules, their retro‐translocation across the ER membrane and ubiquitination for degradation by cytosolic proteasomes. The molecular components of the ERAD pathway and their coordination remain largely unknown. Here we employed co‐immunoprecipitation, silencing or over‐expression assays to show that SEL1L and HRD1 are involved in the degradation of unassembled Ig‐µs, but have minor effects on another substrate, TCR‐α. SEL1L and HRD1 localize in the early secretory apparatus and are induced by ER stress and during B cell differentiation, concomitantly with the onset of massive IgM secretion. These findings reveal a role for SEL1L and HRD1 in IgM quality control. J. Cell. Physiol. 215: 794–802, 2008. © 2008 Wiley‐Liss, Inc.
An improvement in the calculation of the magnetic field for an arbitrary geometry coil with rectangular cross section Int. J. Numer. Model. 2005; 18(6):493–504
Authors: Babic Slobodan I. , Akyel Cevdet 
Published: March 2008

AbstractThe above article was published in Volume 18, Issue 6, Pages 493–504, (October 2005).A number of imperfections were subsequently identified and have been corrected below.On page 497, the following equation has been corrected to:

On page 501, the following equation has been corrected to:

On page 502, the following equation has been corrected to: