bluuebunny/crossref_metadata_2025_split huggingface dataset:
The tert‐Amino Effect in Heterocyclic Chemistry: Synthesis of Spiroheterocycles
Authors: D'yachenko Elisaveta V. , Glukhareva Tatiana V. , Dyudya Lyudmila V. , Eltsov Oleg V. , Morzherin Yury Yu. 
Published: November 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Recent Progress on the Chemical Synthesis of Annonaceous Acetogenins and Their Structurally Modified Mimics
Authors: Hu Tai‐Shan , Wu Yu‐Lin , Yao Zhu‐Jun 
Published: November 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Dynamic Combinatorial Chemistry
Authors: Corbett Peter T. , Leclaire Julien , Vial Laurent , West Kevin R. , Wietor Jean‐Luc , Sanders Jeremy K. M. , Otto Sijbren 
Published: November 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthetic Models of the Active Site of Catechol Oxidase: Mechanistic Studies
Authors: Koval Iryna A. , Gamez Patrick , Belle Catherine , Selmeczi Katalin , Reedijk Jan 
Published: November 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Mass Spectrometric Studies of Non‐Covalent Compounds: Why Supramolecular Chemistry in the Gas Phase?
Authors: Baytekin Bilge , Baytekin H. Tarik , Schalley Christoph A. 
Published: November 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Arylthiopyrrole (AThP) Derivatives as Non‐Nucleoside HIV‐1 Reverse Transcriptase Inhibitors: Synthesis, Structure–Activity Relationships, and Docking Studies (Part 1)
Authors: Di Santo Roberto , Costi Roberta , Artico Marino , Miele Gaetano , Lavecchia Antonio , Novellino Ettore , Bergamini Alberto , Cancio Reynel , Maga Giovanni 
Published: November 2006

AbstractNovel arylthio isopropyl pyridinylmethylpyrrolemethanol (AThP) derivatives 3–5, which are related to capravirine (S‐1153), were synthesized and tested for their ability to block the replication cycle of HIV‐1 in infected cells. The newly synthesized AThPs are active in the concentration range of 0.008–53 μM. Even if compounds 3–5 are generally less potent than S‐1153, their SI values are in some cases similar to that of the reference drug. In fact, the cytotoxicities of AThPs are generally lower than that of S‐1153. Compound 4 e was the most active derivative of this series in cell‐based assays; its potency is similar to that of S‐1153 (EC50=8 and 3 nM, respectively), as is its selectivity index (SI=6250 and 7000, respectively). AThP derivatives were proven to target HIV‐1 RT. In fact, compounds 3–5 generally inhibited the viral enzyme at concentrations similar to those observed in cell‐based assays. A selected number of AThPs (4 k and 5 a,e) were tested against clinically relevant drug‐resistant forms of recombinant reverse transcriptase (rRT) carrying the K103N and Y181I mutations. Carbamate 5 e showed an approximate 240‐fold decrease in activity against Y181I, but only a 10‐fold loss in potency against the K103N rRT form. Docking calculations were also performed to investigate the binding mode of compounds 2, 4 e, 4 j, 4 k and 5 e into the non‐nucleoside binding site of HIV‐1 RT and to rationalize some structure–activity relationships and resistance data.
Arylthiopyrrole (AThP) Derivatives as Non‐Nucleoside HIV‐1 Reverse Transcriptase Inhibitors: Synthesis, Structure–Activity Relationships, and Docking Studies (Part 2)
Authors: Lavecchia Antonio , Costi Roberta , Artico Marino , Miele Gaetano , Novellino Ettore , Bergamini Alberto , Crespan Emmanuele , Maga Giovanni , Di Santo Roberto 
Published: November 2006

AbstractArylthio isopropyl pyridinylmethylpyrrolemethanols (AThPs) have been recently reported as a new class of human immunodeficiency virus type 1 (HIV‐1) reverse transcriptase (RT) inhibitors acting at the non‐nucleoside binding site (NNBS) of this enzyme. Docking experiments of the potent inhibitors 4 k (IC50=0.24  μM, SI=167) and 5 e (IC50=0.11 μM, SI>1667) of wild‐type RT prompted the synthesis and biological evaluation of novel AThP derivatives featuring a number of polar groups in position 3 of the pyrrole ring and larger and more hydrophobic alicyclic substituents in place of the isopropyl group at position 4. Among the compounds synthesized and tested in cell‐based assays against HIV‐1 infected cells, 19 b was the most active, with EC50=0.007 μM, CC50=114.5 μm, and SI=16357. This compound and its precursor 18 b retained interesting activities against clinically relevant drug‐resistant RT forms carrying K103N, Y181I, and L100I mutations. Docking calculations of 10, 14, 18 b, and 19 b were also performed to investigate their binding mode into the RT NNBS and to rationalize both structure–activity relationship and resistance data.
HR‐MAS NMR spectroscopy in the characterization of human tissues: Application to healthy gastric mucosa
Authors: Schenetti Luisa , Mucci Adele , Parenti Francesca , Cagnoli Rita , Righi Valeria , Tosi M. Raffaella , Tugnoli Vitaliano 
Published: November 2006

AbstractThe HR‐MAS is an ideal technique for the investigation of intact tissue specimens (10–50 mg) and permits the obtainment of spectra with a resolution comparable to that observed in solution in a time that does not exceed a half of an hour for a routine analysis. The potentialities of HR‐MAS NMR spectroscopy in the identification of the metabolites characterizing the healthy gastric mucosa are here presented. The direct inspection of the 1D 1H NMR spectra enables only few metabolites to be confidently assigned, and the use of selected 2D experiments strongly amplify the analytical effectiveness of the technique. © 2006 Wiley Periodicals, Inc. Concepts Magn Reson Part A 28A: 430–443, 2006
Stress analyses of laminates under cylindrical bending
Authors: Kant Tarun , Desai Yogesh , Pendhari Sandeep 
Published: November 2006

AbstractA semi‐analytical approach for evaluation of stresses and displacements in composite and sandwich laminates under cylindrical bending subjected to transverse load has been developed in this paper. Two dimensional (2D) partial differential equations (PDEs) of such a laminate are obtained by imposing plane‐strain conditions of elasticity. The fundamental dependent variables are so selected in this formulation that they satisfy the continuity of displacements and transverse interlaminar stresses at the laminate interface through the thickness. The set of governing PDEs are transformed into a set of coupled first‐order ordinary differential equations (ODEs) in thickness direction by assuming suitable global orthogonal trigonometric functions for the fundamental variables satisfying the boundary conditions. These ODEs are numerically integrated by a specially formulated ODE integrator algorithm involving transformation of a two‐point boundary value problem (BVP) into a set of initial value problems (IVPs). Numerical studies on both composite and sandwich laminates for various aspect ratios are performed and presented. Accuracy of the present approach is demonstrated by comparing the results with the available elasticity solution. It is seen that the present results are in excellent agreement with the elasticity solutions. Some new results for sandwich laminates and for uniform loading condition are presented for future reference. Copyright © 2006 John Wiley & Sons, Ltd.
On closed boundary value problems for equations of mixed elliptic‐hyperbolic type
Authors: Lupo Daniela , Morawetz Cathleen S. , Payne Kevin R. 
Published: November 2006

AbstractFor partial differential equations of mixed elliptic‐hyperbolic type we prove results on existence and existence with uniqueness of weak solutions for closed boundary value problems of Dirichlet and mixed Dirichlet‐conormal types. Such problems are of interest for applications to transonic flow and are overdetermined for solutions with classical regularity. The method employed consists in variants of the a − b − c integral method of Friedrichs in Sobolev spaces with suitable weights. Particular attention is paid to the problem of attaining results with a minimum of restrictions on the boundary geometry and the form of the type change function. In addition, interior regularity results are also given in the important special case of the Tricomi equation. © 2006 Wiley Periodicals, Inc.
Asymptotic behavior of the global attractors to the Boussinesq system for Rayleigh‐Bénard convection at large Prandtl number
Authors: Wang Xiaoming 
Published: November 2006

AbstractWe study asymptotic behavior of the global attractors to the Boussinesq system for Rayleigh‐Bénard convection at large Prandtl number. In particular, we show that the global attractors to the Boussinesq system for Rayleigh‐Bénard convection converge to that of the infinite‐Prandtl‐number model for convection as the Prandtl number approaches infinity. This offers partial justification of the infinite‐Prandtl‐number model for convection as a valid simplified model for convection at large Prandtl number even in the long‐time regime. © 2006 Wiley Periodicals, Inc.
Behavior of Temperature‐Sensitive PNIPAM Confined in Polyelectrolyte Capsules
Authors: Prevot Michelle , Déjugnat Christophe , Möhwald Helmuth , Sukhorukov Gleb B. 
Published: November 2006

AbstractLayer‐by‐layer assembled polyelectrolyte microcapsules are of great interest because they can possibly be used as microcontainers and they show interesting stimuli‐responsive properties, which have been recently investigated. Here, we exploit capsules which are made temperature‐sensitive by encapsulating poly(N‐isopropylacrylamide) (PNIPAM). PNIPAM has a cloud point in water at about 32 °C, above which it collapses and is insoluble in water. Further this temperature responsiveness can be tuned by addition of various ions at various concentrations. Here, we present the encapsulation of PNIPAM inside polyelectrolyte microcapsules, and describe the dependence of the lower critical solution temperature (LCST) on the nature and the amount of different salts added. With this information, we demonstrate the ability to tune and finely control the collapse of encapsulated PNIPAM. In this light, this system could be used as a microsensor or drug‐ delivery system.
Magnetic Properties of Poly(propylene imine)–Copper Dendromesogenic Complexes: An EPR Study
Authors: Domracheva Natalia , Mirea Anisoara , Schwoerer Markus , Torre‐Lorente Laura , Lattermann Günter 
Published: November 2006

AbstractCopper(II) complexes formed by coordination of the CuII ion with liquid‐crystalline poly(propylene imine) dendrimer ligand (L) of the first (complex 1) and second (complex 2) generations with various CuII contents (x=Cu/L) have been studied by electron paramagnetic resonance (EPR) spectroscopy. The existence of a redox‐active blue complex 1 (x=1.9) and the copper(II) nitrate electron transfer associated with the valence tautomerism are revealed for the first time in copper‐based dendrimers. It has been shown that the electronic structure of the blue complex 1 (x=1.9) is adequately described as a mixed‐valence dimer containing d 9‐ and diamagnetic d 10‐configurated copper ions, and an antiferromagnetically coupled NO3. radical arising on the nitrate‐bridged counter ligand. The activation energy value found for the electron transfer is about 0.35 meV, which indicates a low‐energy charge dynamic. The ability of the blue and green complexes 1 (x=1.9) dissolved in isotropic solvents to orient themselves in the magnetic field was revealed by EPR spectroscopy. The degree of orientation of the molecular z axis (Sz) of these complexes in the magnetic field differs, depending on the type of copper(II)‐complexing site in the dendrimer ligand, and can reach 0.76, which is close to Sz=1 (completely aligned system). A combination of magnetic and orientational parameters indicates an NO4 environment of the CuII ion in green complex 1 (x=1.9), and confirms the chain structure with intermolecular CuII–NO3–CuII bridges between CuII centres in columns.
Effects of lactate and acetate on the determination of serum ethyl glucuronide by CZE
Authors: Mrázková Michaela , Caslavska Jitka , Thormann Wolfgang , Křivánková Ludmila 
Published: November 2006

AbstractThe analysis of ethyl glucuronide (EtG), a marker of recent alcohol consumption, in serum with an optimized CZE assay is reported. The method uses a 0.1‐mm id fused‐silica capillary of 50 cm effective length that is coated with linear polyacrylamide, a pH 4.4 nicotinic acid/ϵ‐aminocaproic acid (EACA) BGE, reversed polarity and indirect analyte detection. The assay is based on a 1:1 dilution of serum with deionized water and has LODs for EtG, lactate and acetate of 3.8×10−7 M, 2.60×10−6 M and 2.18×10−6 M, respectively. Separation of EtG from endogenous macro‐ and microcomponents (anionic serum components of high and low concentration, respectively) and its quantification are shown to be possible for a wide range of lactate (stacker) and acetate (destacker) concentrations, macrocomponents that have an impact on the CZE behavior of EtG and that change after intake of ethanol. The assay has been successfully applied to the analysis of EtG, lactate and acetate in (i) sera of volunteers that ingested known amounts of alcohol and (ii) samples of patients that were classified (teetotalers and social drinkers vs. alcohol abusers) via analysis of carbohydrate‐deficient transferrin.
On‐line CE‐MS using pressurized liquid junction nanoflow electrospray interface and surface‐coated capillaries
Authors: Fanali Salvatore , D'Orazio Giovanni , Foret Frantisek , Kleparnik Karel , Aturki Zeineb 
Published: November 2006

AbstractA simple and cost‐effective laboratory‐made liquid junction interface was used for coupling of CE with MS. In this device the capillary column and the spray tip were positioned in the electrode vessel containing appropriate spray liquid. The electrospray potential was applied on the electrode inside the liquid junction. A stable electrospray was produced at nanoliter per minute flow rates generated in the emitter tip without using an external pump. This arrangement provided high durability of the spray tip and independent optimization of the CE separation (use of coated capillaries) and ESI conditions. CE‐MS analysis of mixtures of drugs, peptides, tryptic digests of proteins and biological fluids was optimized with respect to the effects of the distance between the separation capillary and electrospray tip and pressure applied on the liquid junction. The sensitivity of the system, in terms of the LOD (base peak monitoring) was below 10 ng/mL for the β‐blocker drugs and below 200 ng/mL for peptide analysis.
Assessing the performance of intumescent coatings using bench‐scaled cone calorimeter and finite difference simulations
Authors: Bartholmai M. , Schartel B. 
Published: November 2006

AbstractA method was developed to assess the heat insulation performance of intumescent coatings. The method consists of temperature measurements using the bench‐scaled experimental set‐up of a cone calorimeter and finite difference simulation to calculate the effective thermal conductivity dependent on time/temperature. This simulation procedure was also adapted to the small scale test furnace, in which the standard time–temperature curve is applied to a larger sample and thus which provides results relevant for approval. Investigations on temperature and calculated effective thermal conduction were performed on intumescent coatings in both experimental set‐ups using various coating thicknesses. The results correspond to each other as well as showing the limits of transferability between both fire tests. It is shown that bench‐scaled cone calorimeter tests are a valuable tool for assessing and predicting the performance of intumescent coatings in larger tests relevant for approval. The correlation fails for processes at surface temperatures above 750°C, which are not reached in the cone calorimeter, but are attained in the small scale furnace set‐up. Copyright © 2006 John Wiley & Sons, Ltd.
IFN‐γ‐induced BACE1 expression is mediated by activation of JAK2 and ERK1/2 signaling pathways and direct binding of STAT1 to BACE1 promoter in astrocytes
Authors: Cho Hyun Jin , Kim Su‐Kyoung , Jin Seok Min , Hwang Eun‐Mi , Kim Yong Sik , Huh Kyoon , Mook‐Jung Inhee 
Published: November 2006

Abstractβ‐Site APP cleaving enzyme 1 (BACE1) is an essential enzyme for the production of β amyloid. Since we found that injection of interferon‐γ (IFN‐γ) into young mouse brains increased BACE1 expression in astrocytes, we investigated molecular mechanisms underlying this process by cloning a putative BACE1 promoter. BACE1 promoter activity was differentially regulated by IFN‐γ in a region specific manner and down‐regulated by an inhibitor of Janus kinase 2 (JAK2). A dominant negative mutant of signal transducer and activator of transcription 1 (STAT1) expression suppressed BACE1 promoter activity, and this was rescued by transfecting wild type STAT1. Electrophoretic mobility shift assay and promoter activity assays indicated that STAT1 binds directly to the putative STAT1 binding sequence of BACE1 promoter. Because IFN‐γ treatment induced STAT1 phosphorylation, we examined whether the expression of a suppressor of cytokine signaling (SOCS), negative regulator of JAK2, suppresses BACE1 promoter activity. The results show that SOCS1 or SOCS3 expression suppressed BACE1 promoter by blocking phosphorylation of Tyr701 residue in STAT1. Also, because IFN‐γ treatment specifically potentiated extracellular signal regulated MAP kinase (ERK) 1/2 activation, pretreatment of mitogen‐activated or extracellular signal‐regulated protein kinase (MEK) inhibitor, PD98059, significantly attenuated IFN‐γ‐induced BACE1 promoter activity and protein expression through blocking phosphorylation of Ser727 residue in STAT1, suggesting that ERK1/2 is associated with IFN‐γ‐induced STAT1 signaling cascade. Taken together, our results suggest that IFN‐γ activates JAK2 and ERK1/2 and then phosphorylated STAT1 binds to the putative STAT1 binding sequences in BACE1 promoter region to modulate BACE1 protein expression in astrocytes. © 2006 Wiley‐Liss, Inc.
TNF‐α/IFN‐γ‐induced iNOS expression increased by prostaglandin E2 in rat primary astrocytes via EP2‐evoked cAMP/PKA and intracellular calcium signaling
Authors: Hsiao Han‐Yun , Mak Oi‐Tong , Yang Chung‐Shi , Liu Yu‐Peng , Fang Kuan‐Ming , Tzeng Shun‐Fen 
Published: November 2006

AbstractAstrocytes, the most abundant glia in the central nervous system (CNS), produce a large amount of prostaglandin E2 (PGE2) in response to proinflammatory mediators after CNS injury. However, it is unclear whether PGE2 has a regulatory role in astrocytic activity under the inflamed condition. In the present work, we showed that PGE2 increased inducible nitric oxide synthase (iNOS) production by tumor necrosis factor‐α and interferon‐γ (T/I) in astrocytes. Pharmacological and RNA interference approaches further indicated the involvement of the receptor EP2 in PGE2‐induced iNOS upregulation in T/I‐treated astrocytes. Quantitative real‐time polymerase chain reaction and gel mobility shift assays also demonstrated that PGE2 increased iNOS transcription through EP2‐induced cAMP/protein kinase A (PKA)‐dependent pathway. Consistently, the effect of EP2 was significantly attenuated by the PKA inhibitor KT‐5720 and partially suppressed by the inhibitor (SB203580) of p38 mitogen‐activated protein kinase (p38MAPK), which serves as one of the downstream components of the PKA‐dependent pathway. Interestingly, EP2‐mediated PKA signaling appeared to increase intracellular Ca2+ release through inositol triphosphate (IP3) receptor activation, which might in turn stimulate protein kinase C (PKC) activation to promote iNOS production in T/I‐primed astrocytes. By analyzing the expression of astrocytic glial fibrillary acidic protein (GFAP), we found that PGE2 alone only triggered the EP2‐induced cAMP/PKA/p38MAPK signaling pathway in astrocytes. Collectively, PGE2 may enhance T/I‐induced astrocytic activation by augmenting iNOS/NO production through EP2‐mediated cross‐talk between cAMP/PKA and IP3/Ca2+ signaling pathways. © 2006 Wiley‐Liss, Inc.
Downregulation of Kir4.1 inward rectifying potassium channel subunits by RNAi impairs potassium transfer and glutamate uptake by cultured cortical astrocytes
Authors: Kucheryavykh Y. V. , Kucheryavykh L. Y. , Nichols C. G. , Maldonado H. M. , Baksi K. , Reichenbach A. , Skatchkov S. N. , Eaton M. J. 
Published: November 2006

AbstractGlial cell‐mediated potassium and glutamate homeostases play important roles in the regulation of neuronal excitability. Diminished potassium and glutamate buffering capabilities of astrocytes result in hyperexcitability of neurons and abnormal synaptic transmission. The role of the different K+ channels in maintaining the membrane potential and buffering capabilities of cortical astrocytes has not yet been definitively determined due to the lack of specific K+ channel blockers. The purpose of the present study was to assess the role of the inward‐rectifying K+ channel subunit Kir4.1 on potassium fluxes, glutamate uptake and membrane potential in cultured rat cortical astrocytes using RNAi, whole‐cell patch clamp and a colorimetric assay. The membrane potentials of control cortical astrocytes had a bimodal distribution with peaks at −68 and −41 mV. This distribution became unimodal after knockdown of Kir4.1, with the mean membrane potential being shifted in the depolarizing direction (peak at −45 mV). The ability of Kir4.1‐suppressed cells to mediate transmembrane potassium flow, as measured by the current response to voltage ramps or sequential application of different extracellular [K+], was dramatically impaired. In addition, glutamate uptake was inhibited by knock‐down of Kir4.1‐containing channels by RNA interference as well as by blockade of Kir channels with barium (100 μM). Together, these data indicate that Kir4.1 channels are primarily responsible for significant hyperpolarization of cortical astrocytes and are likely to play a major role in potassium buffering. Significant inhibition of glutamate clearance in astrocytes with knock‐down of Kir4.1 highlights the role of membrane hyperpolarization in this process. © 2006 Wiley‐Liss, Inc.
On elliptic and parabolic systems with x‐dependent multivalued graphs
Authors: Gwiazda Piotr , Zatorska‐Goldstein Anna 
Published: November 2006

AbstractWe consider elliptic and parabolic systems with multivalued x‐dependent graphs. The existence of solutions for elliptic equation was established in (Ann. Inst. H. Poincare Anal. Non Linéaire 1990; 7(3):123–160; Boll. Unione Mat. Ital. Sez. B Artic. Ric. Mat. (8) 2004; 7(1):23–59). We extend this result to the elliptic and parabolic systems, in particular to the systems describing a flow of non‐Newtonian incompressible fluids. Contrary to these two papers we follow the spirit of the compactness method of J. L. Lions for variational‐type operators, however, expanded on the framework of measure‐valued solutions. The main concept consists in applying the relation between x‐dependent maximal monotone graphs and 1‐Lipschitz Carathéodory functions to introduce the generalized Young measures. The method was announced in the short note (C. R. Math. Acad. Sci. Paris 2005; 340(7):489–492). Copyright © 2006 John Wiley & Sons, Ltd.