bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxetane δ‐Amino Acids: Chemoenzymatic Synthesis of 2,4‐Anhydro‐5‐N‐(t‐butoxycarbonyl)amino‐D‐lyxonic Acid (XI).
Authors: Lucas Susana Dias , Iding Hans , Alker Andre , Wessel Hans Peter 
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.
Dde as a Protecting Group for Carbohydrate Synthesis.
Authors: Bornaghi Laurent , Dekany Guyla , Drinnan Nicholas B. , Taylor Stephen , Toth Istvan , West Michael L. 
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.
Synthesis of N‐Protected Galactosamine Building Blocks from D‐Tagatose via the Heyns Rearrangement.
Authors: Wrodnigg Tanja M. , Lundt Inge , Stuetz Arnold E. 
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.
Synthesis of the Dimethyl Ester of 1‐Deoxy‐L‐idonojirimycin‐1‐methylenephosphonate: A New Approach to Iminosugar Phosphonates.
Authors: La Ferla Barbara , Bugada Piergiuliano , Nicotra Francesco 
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.
Syntheses Based on Anabasine. Preparation and Transformations of N‐Oxides.
Authors: Musina L. A. , Shul'ts E. E. , Krichevskii L. A. , Adekenov S. M. , Shakirov M. M. , Tolstikov G. 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.
In vitro Leishmanicidal Constituents from Millettia pendula.
Authors: Takahashi Marii , Fuchino Hiroyuki , Sekita Setsuko , Satake Motoyoshi , Kiuchi Fumiyuki 
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.
Equation of State and Phase Diagram of Quartz
Authors: Petrovtsev A. V. , Dremov V. V. , Vildanov V. G. , Gorshkov M. M. , Zahikin V. T. , Zhugin Yu. N. 
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.
One‐Dimensional Coloidal Gold and Silver Nanostructures
Authors: Murphy Catherine J. , Gole Anand M. , Hunyadi Simona E. , Orendorff Christopher J. 
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.
2‐Methyl‐4‐oxo‐4H‐1‐benzopyran‐4‐one as a Synthon in Heterocyclic Chemistry
Authors: Ghosh Chandra Kanta 
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.
3,5‐Dihalo‐2(1H)‐pyrazinones: Versatile Scaffolds in Organic Synthesis
Authors: Pawar Vijaykumar G. , De Borggraeve Wim M. 
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.
Bis‐Tetrahydrofuran: A Privileged Ligand for Darunavir and a New Generation of HIV Protease Inhibitors that Combat Drug Resistance.
Authors: Ghosh Arun K. , Sridhar Perali Ramu , Kumaragurubaran Nagaswamy , Koh Yasuhiro , Weber Irene T. , Mitsuya Hiroaki 
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.
Supramolecular Organization in Crystals Containing Quinoline‐2‐ Carboxylates and 9,10‐Dihydro‐9‐oxo‐10‐acridineacetates
Authors: Dobrzynska Danuta 
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.
Operator formalisms: An overview
Authors: Bain Alex D. 
Published: November 2006

AbstractOperator formalisms are mathematical recipes for simplifying the manipulations of the density matrix. Because the density matrix is a vital tool in describing and analyzing magnetic resonance experiments, many approaches have been developed. This article gives an overview of a number of different methods: spherical tensors, fictitious spin‐1/2, single‐transition operators, product operators, superspin methods, and others. In principle, they all must give the same answer, because an exact description of magnetic resonance phenomena is usually within reach. The choice of the formalism for the user, therefore, depends on various personal decisions. Among these decisions is the choice between spherical and Cartesian tensors, between Hilbert space and Liouville space, between commutators and matrix elements, and so on. We do not go into the details of any of the formalisms but rather try to compare their approaches at a fairly general level. The quadrupolar echo pulse sequence is used as an example of the application of the formalisms. The aim of this overview is to give readers enough of a picture so that they can make an intelligent choice for themselves. © 2006 Wiley Periodicals, Inc. Concepts Magn Reson Part A 28A: 369–383, 2006
Understanding spin turbulence in solution magnetic resonance through phase space dynamics and instability
Authors: Datta Sandip , Huang Susie Y. , Lin Yung‐Ya 
Published: November 2006

AbstractThe joint action of two feedback fields in solution magnetic resonance (MR), radiation damping and the distant dipolar field, are known to give rise to nonlinear evolution of the magnetization at high fields. The different stages of the resulting complex dynamics are explored here, and standard tools and terminology adopted from the theory of nonlinear dynamics are introduced to analyze the underlying dynamics. The nonlinear spin dynamics are shown to generate unexpected artifacts in routine MR experiments involving bulk solvents. Approaches to curtail the effects of the joint feedback fields are discussed, as well as applications exploiting these fields as new contrast enhancement mechanisms for MR imaging. © 2006 Wiley Periodicals, Inc. Concepts Magn Reson Part A 28A: 410–421, 2006
On the physical interpretation of density operators at the atomic scale: A thorough analysis of some simple cases
Authors: Paniagua Juan C. 
Published: November 2006

AbstractThe physical meaning of the concepts underlying the density operator formalism are analyzed from different points of view. In particular, the diversity of ways of expressing the density operator of the simplest NMR sample is exploited to show that there are many molecular‐scale physical pictures compatible with each macroscopic state, some of them being more useful than others for specific aims. Those corresponding to diagonal representations of the density matrix conform closely to classical‐like pictures, which allow us to ignore the subtle effects of quantum interferences that are implicit in the concept of coherence. A widespread biconical picture that does not rely on a sound physical basis is shown to be quantitatively valid provided that ad hoc populations are chosen for the involved quantum states. The interpretation of the coefficients of the density operator expansion in terms of observable‐related basis elements is discussed to show that the identification of these with the corresponding physical properties can be misleading in certain cases. © 2006 Wiley Periodicals, Inc. Concepts Magn Reson Part A 28A: 384–409, 2006
Fast multipole boundary element analysis of two‐dimensional elastoplastic problems
Authors: Wang P. B. , Yao Z. H. 
Published: November 2006

AbstractThis paper presents a fast multipole boundary element method (BEM) for the analysis of two‐dimensional elastoplastic problems. An incremental iterative technique based on the initial strain approach is employed to solve the nonlinear equations, and the fast multipole method (FMM) is introduced to achieve higher run‐time and memory storage efficiency. Both of the boundary integrals and domain integrals are calculated by recursive operations on a quad‐tree structure without explicitly forming the coefficient matrix. Combining multipole expansions with local expansions, computational complexity and memory requirement of the matrix–vector multiplication are both reduced to O(N), where N is the number of degrees of freedom (DOFs). The accuracy and efficiency of the proposed scheme are demonstrated by several numerical examples. Copyright © 2006 John Wiley & Sons, Ltd.
Transient Analysis of Proton Electrolyte Membrane Fuel Cells (PEMFC) at Start‐Up and Failure
Authors: Serincan M. F. , Yesilyurt S. 
Published: November 2006

AbstractA two‐dimensional, transient, single‐phase computational model, incorporating water transport in the membrane and the flow and transport of species in porous gas diffusion electrodes is developed to evaluate the transient performance of a PEMFC with interdigitated gas distributors. The co‐flow and counter‐flow of the anode and cathode reactants are discussed to address their effects on PEMFC performance and transients. The important role of water transport in the membrane on the transients is demonstrated. The membrane's water intake or outtake determines the duration of the transients. The effect of the operating conditions on steady state and transient performances is outlined. Overshoots and undershoots are observed in the average current density, due to a step change in the cell voltage and the cathode pressure under start‐up conditions. Simulation results are used to address the role of auxiliary components in the failure modes of the PEMFC.
Distinct roles of protein kinase R and toll‐like receptor 3 in the activation of astrocytes by viral stimuli
Authors: Carpentier Pamela A. , Williams Bryan R. , Miller Stephen D. 
Published: November 2006

AbstractImpaired immune surveillance and constitutive immunosuppressive properties make the central nervous system (CNS) a particular challenge to immune defense, and require that CNS‐resident cells be capable of rapidly recognizing and responding to infection. We have previously shown that astrocytes respond to treatment with a TLR3 ligand, poly I:C, with the upregulation of innate immune functions. In the current study, we examine the activation of innate immune functions of astrocytes by Theiler's murine encephalomyelitis virus (TMEV), a picornavirus, which establishes a persistent infection in the CNS of susceptible strains of mice and leads to the development of an autoimmune demyelinating disease that resembles human multiple sclerosis. Astrocytes infected with TMEV are activated to produce type I interferons, the cytokine IL‐6, and chemokines CCL2 and CXCL10. We further examined the mechanisms that are responsible for the activation of astrocytes in response to direct viral infection and treatment with poly I:C. We found that the cytoplasmic dsRNA‐activated kinase PKR is important for innate immune responses to TMEV infection, but has no role in their induction by poly I:C delivered extracellularly. In contrast, we found that TLR3 has only a minor role in responses to TMEV infection, but is important for responses to poly I:C. These results highlight the differences between responses induced by direct, nonlytic virus infection and extracellular poly I:C. The activation of astrocytes through these different pathways has implications for the initiation and progression of viral encephalitis and demyelinating diseases such as multiple sclerosis. © 2006 Wiley‐Liss, Inc.
PKCϵ induces astrocytic differentiation of multipotential neural precursor cells
Authors: Steinhart Rivka , Kazimirsky Gila , Okhrimenko Hana , Ben‐Hur Tamir , Brodie Chaya 
Published: November 2006

AbstractIn this study, we examined the role of PKC in the differentiation of multipotential neural precursor cells (NPCs). We found that the NPCs expressed PKCα,β2,δ,ϵ,ζ and low levels of PKCγ. The PKC activator, PMA, selectively increased the number of astrocytes, whereas it decreased the generation of neurons and oligodendrocytes. Similarly, overexpression of PKCϵ increased the differentiation of astrocytes and a PKCϵKD mutant abolished PMA effect. PMA phosphorylates PKCϵ on serine 729. Using a PKCϵS729A mutant, we found that the phosphorylation of PKCϵ on serine 729 was essential for the differentiation of astrocytes induced by PMA. To delineate the mechanisms involved in PMA and PKCϵ effects, we examined the expression of Notch1, which has been associated with astrocytic differentiation. We found that PMA and PKCϵ induced a large increase in Notch1 expression and the PKCϵS729A mutant abolished PMA effect. Moreover, the PKCϵS729A mutant also inhibited the effect of CNTF on astrocytic differentiation and Notch 1 expression. Finally, Notch1 mediated the effect of PMA on astrocytic differentiation, since the γ‐secretase inhibitor L‐685,458, and Notch1 silencing abolished PMA effect. Our data suggest an important role of PKCϵ in astrocytic differentiation and implicate Notch1 as a possible mediator of this effect. © 2006 Wiley‐Liss, Inc.
Neogene aquifer properties specified through the interpretation of electrical sounding data, Salamiyeh region, central Syria
Authors: Asfahani Jamal 
Published: November 2006

AbstractTwenty‐nine Schlumberger electrical soundings were carried out in the Salamiyeh region in Syria using a maximum current electrode separation of 1 km. Three soundings were made at existing boreholes for comparison. Aquifer parameters of hydraulic conductivity and transmissivity were obtained by analysing pumping test data from the existing boreholes. An empirical relationship between hydraulic conductivity determined from the pumping test and both resistivity and thickness of the Neogene aquifer has been established for these boreholes in order to calculate the geophysical hydraulic conductivity. A close agreement has been obtained between the computed hydraulic conductivity and that determined from the pumping test. The relationship established has, therefore, been generalized in the study area in order to evaluate hydraulic conductivity and transmissivity at all the points where geoelectrical measurements have been carried out. This generalization allows one to derive maps of the hydraulic conductivity and transmissivity in the study area based on geoelectrical measurements. These maps are important in future modelling processes oriented towards better exploitation of the aquifers. Copyright © 2006 John Wiley & Sons, Ltd.
Investigations on surface and subsurface drainage requirements at regional scale
Authors: Kumar Krishan , Singh J. , Gupta S. K. 
Published: November 2006

AbstractAmongst the three drainage basins in Haryana (India), the inland drainage basin is most prone to surface stagnation, rise in groundwater table and soil salinization. In order to understand the surface and subsurface drainage requirements of this basin, a number of groundwater regime maps (groundwater table contour map, depth to groundwater table map, groundwater fluctuation map and groundwater quality map) were prepared to assess long‐term groundwater table behaviour in a part (comprising Rohtak and Jhajjar districts) of this basin for the period 1984–98. Groundwater movement was observed to occur towards the central part of the study area, a possible cause of waterlogging and degradation in groundwater quality. The groundwater levels during the past two and a half decades (1974–98) registered a rise varying from 1 to 19 m with an average rise of 21 cm yr−1. The rainfall data of Rohtak and Jhajjar districts for the period (1975–98) were analysed for different frequencies of exceedance to determine 1, 2 and 3 days of consecutive rainfall. The surface drainable surplus was calculated taking into account the water storage in the soil profile, infiltration rates and evaporation that varied from 30–35, 35–40 and 5 mm day−1 respectively. The drainable surplus for consecutive 1, 2 and 3 days' rainfall for a 5‐year return period was 161, 113 and 0 m3 s−1 respectively. The existing surface drainage system with a capacity of 170 m3 s−1 and with availability of dead storage, could handle 1 and 2 days' consecutive rainfall for a 5‐year return period when full initial storage of 30–35 cm (equivalent to 50% of the available moisture) is available in the soil profile. From the groundwater regime maps, it was also estimated that nearly 16% of the study area (57 932 ha) required treatment with subsurface drainage. Therefore, a groundwater model (SWAP) was used to predict the subsurface drainable surplus considering various inputs related to the water balance of the area. The subsurface drainable surplus over the simulated years ranged between 0.4 and 1.92 mm day−1. This range is quite close to the recommended range of the subsurface drainage coefficient for this region on the basis of field trials. The study of irrigation and drainage maps of the area revealed that there is a need to strengthen field surface drains and introduce subsurface drainage in the area. As such, the methodology proposed in this paper could be used to investigate drainage requirements on a regional scale. Copyright © 2006 John Wiley & Sons, Ltd.
The welfare effects of restricted hospital choice in the US medical care market
Authors: Ho Katherine 
Published: November 2006

AbstractManaged care health insurers in the USA restrict their enrollees' choice of hospitals to within specific networks. This paper considers the implications of these restrictions. A three‐step econometric model is used to predict consumer preferences over health plans conditional on the hospitals they offer. The results indicate that consumers place a positive and significant weight on their expected utility from the hospital network when choosing plans. A welfare analysis, assuming fixed prices, implies that restricting consumers' choice of hospitals leads to a loss to society of approximately $1 billion per year across the 43 US markets considered. This figure may be outweighed by the price reductions generated by the restriction. Copyright © 2006 John Wiley & Sons, Ltd.
Frequent mutation of p16CDKN2A exon 1 during rat tongue carcinogenesis induced by 4‐nitroquinoline‐1‐oxide
Authors: Hong Yun , Yang Linglan , Li Chunyang , Xia Hongbin , Rhodus Nelson L. , Cheng Bin 
Published: November 2006

AbstractIn this study we explored the mutation types of p16CDKN2A exon 1 and the corresponding frequencies in experimental rat tongue carcinogenesis. Twenty barrier Sprague–Dawley (SD) rats were divided into the control (n = 5) and experimental group (n = 15), to which 4‐nitroquinoline‐1‐oxide (4‐NQO) in drinking water was administered. Two samples of normal, three samples of moderate/severe dysplasia and four samples of invasive squamous cell carcinoma lesions were selected following strict histopathological examination in double‐blind manner. The PCR products of p16CDKN2A exon 1 amplified from these tissues were sequenced. Point mutations of p16CDKN2A exon 1 were found in all of the precancerous and cancerous lesions. Half of the mutations were detected on guanine (G). Twenty mutations, including a missense mutation of the start codon resulting in alternative reading frame of p16CDKN2A exon 1, were also identified. These preliminary results suggested that mutation of p16CDKN2A exon 1 might be an early molecular event of rat tongue carcinogenesis induced by 4NQO and G was the mutation hotspot. © 2006 Wiley‐Liss, Inc.
Deoxycholic acid promotes the growth of colonic aberrant crypt foci
Authors: Flynn Christopher , Montrose David C. , Swank Daniel L. , Nakanishi Masako , Ilsley Jillian N.M. , Rosenberg Daniel W. 
Published: November 2006

AbstractAKR/J mice are resistant to the tumorigenic properties of the colon carcinogen, azoxymethane (AOM). Following AOM exposure, limited numbers of preneoplastic lesions, referred to as aberrant crypt foci (ACF), are formed in the colon, and their progression to tumors rarely occurs. To determine whether genetic resistance can be overcome by exposure to a dietary tumor promoter, AOM‐exposed AKR/J mice were fed a diet containing 0.25% deoxycholic acid (DCA). DCA exposure was begun 1 wk prior to or 1 wk after tumor initiation with AOM. Mice placed on the DCA diet prior to AOM treatment developed a significantly higher multiplicity of ACF compared to AOM‐exposed mice fed a control diet (15.50 ± 0.96 vs. 6.17 ± 0.48, respectively; P < 0.05). When DCA exposure was begun after AOM treatment (post‐initiation), ACF formation was further enhanced (34.00 ± 1.22). Interestingly, increased numbers of ACF were associated with the presence of nuclear β‐catenin, assessed by immunohistochemistry. While ∼33% of ACF from mice exposed to DCA prior to AOM treatment contained positive nuclear β‐catenin staining, ∼77% of ACF from mice fed DCA after AOM were positive. Accumulation of nuclear β‐catenin was not associated with a loss of E‐cadherin from the plasma membrane, although loss of APC staining was a consistent feature of most AOM‐induced ACF, regardless of DCA exposure. These results demonstrate that exposure to DCA, an important digestive component, is sufficient to sensitize the resistant AKR/J colon to formation of high‐grade dysplasia, and that nuclear translocation of β‐catenin may play an important role in this process. © 2006 Wiley‐Liss, Inc.
Expression of secretory phospholipase A2 in colon tumor cells potentiates tumor growth
Authors: Belinsky Glenn S. , Rajan Thiruchandurai V. , Saria Elizabeth A. , Giardina Charles , Rosenberg Daniel W. 
Published: November 2006

AbstractSecretory phospholipase A2 (sPLA2‐IIA) has been shown to attenuate intestinal tumorigenesis in ApcMin mice, demonstrating that it is a tumor modifier. To further explore the actions of sPLA2‐IIA in tumorigenesis, sPLA2‐IIA was overexpressed in two cell lines where it is normally absent, the murine colon tumor cell line AJ02nm0, and human colon carcinoma cell line HCT‐116. Two allelic variants of sPLA2‐IIA were tested in this study; sPLA2‐IIAAKR and sPLA2‐IIASWR, which are derived from AKR/J and SWR/J mice, respectively, and differ by a single amino acid at position 63 in the calcium‐ and receptor‐binding domain. There was no change in cell‐doubling time for either allele when compared to vector controls. Furthermore, sodium butyrate and arachidonic acid (AA)‐induced cell death were unchanged in control and transfected cells. Addition of the sPLA2 substrate, palmitoyl‐arachidonoyl‐phosphatidic acid (PAPA), to AJ02nm0 cells resulted in a modest (12%–24%), but significant (P < 0.01), inhibition of growth that was dependent on sPLA2‐IIA expression. However, when AJ02nm0 and HCT‐116 cells were injected subcutaneously (sc) into nude mice, Pla2g2a expression resulted in a 2.5‐fold increase in tumor size. In addition, sPLA2‐IIA expressing HCT‐116 tumors were found to be more infiltrative than controls. We conclude that the ability of sPLA2‐IIA to slow tumor cell growth is dependent upon the availability of substrate, and that in some instances sPLA2‐IIA may actually enhance tumor growth. Mechanisms that may account for differences between the tumor explant model versus the ApcMin model of intestinal cancer are discussed. © 2006 Wiley‐Liss, Inc.