bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mild, Single‐Pot Hydrocarboxylation of Gaseous Alkanes to Carboxylic Acids in Metal‐Free and Copper‐Promoted Aqueous Systems
Authors: Kirillova Marina V. , Kirillov Alexander M. , Pombeiro Armando J. L. 
Published: May 2010

AbstractA direct, selective and highly efficient method has been developed for the hydrocarboxylation of Cn gaseous alkanes into Cn+1 carboxylic acids, in aqueous acid‐solvent‐free medium at low temperatures. The approach is based on a metal‐free or copper‐promoted reaction of ethane, propane or n‐butane with carbon monoxide and water, in a H2O/MeCN medium at 50–60 °C, in the presence of potassium peroxodisulfate. The effects of various reaction parameters, such as the absence or presence of a copper promoter, solvent composition, temperature, time, CO and alkane pressure, were studied. A free radical mechanism was confirmed by radical trap experiments involving acyl radical formation, oxidation and subsequent hydroxylation by water. Remarkable yields (based on alkane) of carboxylic acids in the 34–41 % range were achieved even in the metal‐free systems, although in the presence of a tetracopper(II) triethanolaminate derived promoter they reach superior values of 58 and 87 % for the hydrocarboxylations of propane and n‐butane, respectively; in these cases, branched isobutyric and 2‐methylbutyric acids were the predominant products. From a green perspective, important features of the present alkane hydrocarboxylations include the exceptional metal‐free, mild and acid‐solvent‐free reaction conditions, the operation in aqueous medium with a rare hydroxylating role of water, with high selectivities, and yields of carboxylic acids. Taken together, these conditions correspond to the mildest and the most efficient method so far reported for the oxidative functionalisation of gaseous alkanes.
HIV‐1 impairs in vitro priming of naïve T cells and gives rise to contact‐dependent suppressor T cells
Authors: Che Karlhans F. , Sabado Rachel L. , Shankar Esaki M. , Tjomsland Veronica , Messmer Davorka , Bhardwaj Nina , Lifson Jeffrey D. , Larsson Marie 
Published: May 2010

AbstractPriming of T cells in lymphoid tissues of HIV‐infected individuals occurs in the presence of HIV‐1. DC in this milieu activate T cells and disseminate HIV‐1 to newly activated T cells, the outcome of which may have serious implications in the development of optimal antiviral responses. We investigated the effects of HIV‐1 on DC–naïve T‐cell interactions using an allogeneic in vitro system. Our data demonstrate a dramatic decrease in the primary expansion of naïve T cells when cultured with HIV‐1‐exposed DC. CD4+ and CD8+ T cells showed enhanced expression of PD‐1 and TRAIL, whereas CTLA‐4 expression was observed on CD4+ T cells. It is worth noting that T cells primed in the presence of HIV‐1 suppressed priming of other naïve T cells in a contact‐dependent manner. We identified PD‐1, CTLA‐4, and TRAIL pathways as responsible for this suppresion, as blocking these negative molecules restored T‐cell proliferation to a higher degree. In conclusion, the presence of HIV‐1 during DC priming produced cells with inhibitory effects on T‐cell activation and proliferation, i.e. suppressor T cells, a mechanism that could contribute to the enhancement of HIV‐1 pathogenesis.
A Supramolecular Derivative of a Nanoporous Molybdenum Oxide Based Inorganic Keplerate with Self‐Defocusing Nonlinear Optical Properties
Authors: Zhang Lijuan , Zhou Yunshan , Han Ruixue 
Published: May 2010

AbstractA new derivative of the highly charged inorganic Keplerate of the type {pentagon}12{linker}30 ≡ {(Mo)Mo5O21(H2O)6}12{Mo2O4(SO4)}30 with the formula (NH4)28(NH2CHNH2)6Gd3[{(NH2CHNH2)20 + Gd3 + (H2O)50} ⊂ {(MoVI)MoVI5O21(H2O)6}12 {MoV2O4(SO4)}30]·ca.250H2O was isolated and characterized by elemental analysis, IR and UV/Vis spectroscopy, single‐crystal X‐ray analysis, and magnetic susceptibility measurements. Three Gd3+ ions are found inside the internal cavity of the capsule. The coordination sphere of each Gd3+ ion is completed by the oxygen atoms of SO4 groups that act as bidentate ligands to a {Mo2} linker and by the oxygen atoms of the encapsulated new two‐shell underoccupied [{H2O}60+20 + {H2O}20] water cluster that acts as polydentate ligand. Twenty HC(NH2)2+ cations interact with the twenty {Mo9O9} pores through hydrogen bonds between the O and H atoms of the two NH2 groups, which demonstrates a surface supramolecular chemistry. Of importance, a third‐order nonlinear optical investigation, using the Z‐scan technique, shows for the first time that the derivative demonstrates a strong self‐defocusing third‐order nonlinear optical effect with large third‐order nonlinear optical susceptibility. This observation implies that these unique inorganic Keplerates and their derivatives might find applications in nonlinear optical materials science.
Synthesis, Spectroscopic and Magnetic Properties of the Co2(OH)(PO4)1–x(AsO4)x [0 ≤ x ≤ 1] Solid Solution
Authors: de Pedro Imanol , Rojo José María , Rodríguez Fernández Jesús , Lezama Luis , Rojo Teófilo 
Published: May 2010

AbstractThe Co2(OH)(PO4)1–x(AsO4)x [0 ≤ x ≤ 1] solid solution was prepared by hydrothermal synthesis and, polycrystalline samples characterized by X‐ray powder diffraction and spectroscopic measurements. The cell parameters of the isostructural phosphate–arsenate phases follow Vegard's law in the whole range of composition. The IR spectra are characteristic of three distinct features corresponding principally to the vibrations of both the hydroxide and tetrahedral (XO4)3– (X = P, As) groups together with the evolution of the intensity of stretching [νas (X–O)] vibration modes corresponding to the PO4 and AsO4 tetrahedra in the solid solution. Diffuse reflectance data show bands belonging to the octahedral and trigonal bipyramidal geometries of the Co2+ ions with a high degree of covalence in the Co–O bonds of the arsenate phases. Magnetization measurements of Co2(OH)(PO4)1–x(AsO4)x [0 ≤ x ≤ 1] show the existence of antiferromagnetic interactions with the presence of a ferromagnetic component below the ordering temperature. TN decreases from 71 to 19 K as the arsenate amount is increased. ZFC‐FC curves show irreversibility just below TN for Co2(OH)(PO4)1–x(AsO4)x [x = 0.1–0.75]. The magnetic behavior of Co2(OH)(PO4)0.1(AsO4)0.9 is completely different from the rest of the hydroxyphosphate–arsenate members and similar to that observed in the undoped arsenate compound where an incommensurate magnetic phase is observed.
A Comparative Study on the Reactivity of Tris‐β‐Diketiminate Ytterbium Complexes: Steric Effect of β‐Diketiminato Ligands
Authors: Jiao Rui , Xue Mingqiang , Shen Xiaodong , Zhang Yong , Yao Yingming , Shen Qi 
Published: May 2010

AbstractA series of tris‐β‐diketiminate ytterbium complexes with the general formula [YbL3] {L = [N(C6H5)C(Me)]2CH–, LH (1); [N(4‐MeC6H4)C(Me)]2CH–, L4‐Me (2), and [N(2‐MeC6H4)C(Me)]2CH–, L2‐Me (3)} were synthesized and structurally characterized. All complexes have longer Yb–N bond lengths than other YbL‐containing derivatives, and complex 3 has the longest average Yb–N bond length. A comparative study on the reactivity of complexes 1–3 revealed that complex 3 was a highly active catalyst for the polymerization of ϵ‐caprolactone and L‐lactide, as well as for the addition of amines to carbodiimides, whereas both complexes 1 and 2 were almost inactive under the same conditions. The active sequence is consistent with the distance of the Yb–N bond, which is reflected in the sterically induced activation of the bulky tris‐β‐diketiminate ytterbium complexes.
Regiospecific Three‐Component Access to Fluorescent 2,4‐Disubstituted Quinolines via One‐Pot Coupling‐Addition‐Cyclocondensation‐Sulfur Extrusion Sequence
Authors: Rotzoll Sven , Willy Benjamin , Schönhaber Jan , Rominger Frank , Müller Thomas J. J. 
Published: May 2010

Abstract2,4‐Di‐ and 2,4,7‐trisubstituted quinolines are readily synthesized in a regioselective fashion from acyl chlorides, terminal alkynes, and 2‐aminothiophenols by a consecutive, microwave‐assisted one‐pot three‐component Sonogashira coupling‐Michael addition–cyclocondensation sequence and following sulfur extrusion in moderate to good yields. The terminal sulfur extrusion step was studied by DFT computations. The absorption spectra of 2,4‐disubstituted quinolines can be rationalized by DFT‐ZINDO‐CI calculations and all derivatives show intense blue emission upon UV excitation.
Probing Fluorine Interactions in a Polyhydroxylated Environment: Conservation of a C–F···H–C Recognition Motif in Presence of O–H···O Hydrogen Bonds
Authors: Mehta Goverdhan , Sen Saikat 
Published: May 2010

AbstractThree conformationally locked fluorinated polycyclitols have been specially crafted on a rigid trans‐decalin backbone, employing a surprisingly facile pyridine‐poly(hydrogen fluoride)‐mediated stereospecific epoxide ring opening as the key reaction. Molecular design of the three fluorinated probes under study focused on providing an efficient platform for (a) evaluating the ability of covalently bonded fluorine, vis‐à‐vis the isosteric hydroxy group, to act as a H‐bond acceptor and (b) examining the possibility for an organic fluorine moiety, placed suitably in a spatially invariant position, to engage an 1,3‐diaxial OH functionality in a purported intramolecular O–H···F hydrogen bond. The present endeavour reveals that C(sp3)–F···H–C(sp3) hydrogen bonds, though weak and lesser investigated, can indeed be observed and supramolecular recognition motifs, involving such interactions, can be conserved even in crystal structures laden with stronger O–H···O hydrogen bonds.
Polymer‐Supported Chiral Organocatalysts: Synthetic Strategies for the Road Towards Affordable Polymeric Immobilization
Authors: Kristensen Tor E. , Hansen Tore 
Published: May 2010

AbstractIn this microreview, we highlight the field of polymer‐supported organocatalysis, especially immobilized enamine and iminium organocatalysts. We try to formalize the overall synthetic strategies for polymeric immobilization as spanning the area of two overlapping regions, from a copolymer strategy favoured by low‐valued and small catalysts to a classical post‐modification strategy favoured by valuable and/or large catalysts. Organocatalysis is particularly interesting as it is probably best described as being located in the transitional region, and we will trace the historic and factual origins for the unfortunate predispositions towards post‐modification schemes. In addition, we try to identify affordable and useful syntheses of key organocatalyst immobilization intermediates, as well as polymer supports that are more compatible with a broader range of reaction solvent polarity, something of crucial importance in organocatalysis.
The 3‐Hydroxypiperidine Skeleton: Key Element in Natural Product Synthesis (Eur. J. Org. Chem. 15/2010)
Authors: Wijdeven Marloes A. , Willemsen Jorgen , Rutjes Floris P. J. T. 
Published: May 2010

AbstractThe cover picture shows an artistic impression of the interaction of different types of 3‐hydroxypiperidine‐containing natural products with an imaginary receptor protein. The 3‐hydroxypiperidine motif represents a privileged structural element that occurs in a large variety of biologically relevant compounds displaying a range of activities. Examples include the natural products 3‐hydroxypipecolic acid, prosopinine, morusimic acid D, cassine and febrifugine. Enantioselective synthetic strategies to these compounds are presented in the Microreview by F. P. J. T. Rutjes et al. on p. 2831 ff. Cover picture design by Dr. Sander S. van Berkel.
Looking for honesty: The primary role of morality (vs. sociability and competence) in information gathering
Authors: Brambilla Marco , Rusconi Patrice , Sacchi Simona , Cherubini Paolo 
Published: May 2010

AbstractResearch on the two fundamental dimensions of social judgment, namely warmth and competence, has shown that warmth has a primary and a dominant role in information gathering about others. In two studies we examined whether the sociability and morality components of warmth play distinct roles in such a process. Study 1 (N = 60) investigated which traits were mostly selected when forming impressions about others. The results showed that, regardless of the task goal, traits related to morality and sociability were differently processed. Furthermore, participants were more interested in obtaining information about morality than about sociability when asked to form a global impression about others. Study 2 (N = 98) explored the adoption of asymmetric/symmetric strategies when asking questions to make inferences on others. As predicted, participants adopted an asymmetrically disconfirming strategy on morality traits, while they looked for more symmetrical evidence on sociability or competence traits. Overall, our findings indicated a distinct and a dominant role of the moral component of warmth in the information‐gathering process. Copyright © 2010 John Wiley & Sons, Ltd.
The hunt for the epiallele
Authors: Finer Sarah , Holland Michelle L. , Nanty Lisa , Rakyan Vardhman K. 
Published: May 2010

AbstractUnderstanding the origin of phenotypic variation remains one of the principle challenges of contemporary biology. Recent genome‐wide association studies have identified association between common genetic variants and complex phenotype; however, the minimal effect sizes observed in such studies highlight the potential for other causal factors to be involved in phenotypic variation. The epigenetic state of an organism (or ‘epigenome’) incorporates a landscape of complex and plastic molecular events that may underlie the ‘missing link’ that integrates genotype with phenotype. The nature of these processes has been the subject of intense scientific study over the recent years, and characterisation of epigenetic variation, in the form of ‘epialleles’, is providing fascinating insight into how the genome functions within a range of developmental processes, environments, and in states of health and disease. This review will discuss how and when mammalian epialleles may be generated and their interaction with genetic and environmental factors. We will outline how an epiallele has a variable relationship with phenotype, and how new technologies may be used for their detection and to facilitate an understanding of their contribution to phenotype. Finally, we will consider epialleles in population variation and their teleological role in evolution. variation and their teleological role in evolution. Environ. Mol. Mutagen. 52:1–11, 2011. © 2010 Wiley‐Liss, Inc.
Combining rapid bioassessment and field-based microcosms for identifying impacts in an urban river
Authors: O'Brien Matthew L. , Pettigrove Vincent , Carew Melissa E. , Hoffmann Ary A. 
Published: May 2010

Abstract
Rapid bioassessment indices based on macroinvertebrates are the most commonly used tools for assessing stream condition. However, once stream degradation has been detected, it is often difficult to identify which environmental stressors are most important because of changes in multiple correlated factors. In this study, we examined eight sites in an urban river watershed using a field-based microcosm experiment and the rapid bioassessment-based biotic index, SIGNAL. The experiment assessed the effects of polluted river sediment by examining the macroinvertebrate taxa that colonized sediments at an unpolluted wetland. Results were compared with an assessment of field-collected macroinvertebrates using SIGNAL, a biotic index that assigns pollution sensitivity scores to macroinvertebrate families, and environmental data, to determine whether sediment pollution or other factors such as habitat deterioration were likely to be influencing riverine macroinvertebrate communities. The microcosm results indicated that common species (Tanytarsus fuscithorax, Procladius paludicola, and Ablabesmyia notabilis) and the overall macroinvertebrate assemblage did not significantly change among sediments from different sites, with the exception of local effects on a few uncommon taxa (Chironomus pseudoppositus, Kiefferulus martini, Cladotanytarsus australomancus, Chaoboridae, Polypedilum “S1,” and Tanytarsus belairensis). In contrast, SIGNAL showed a gradual trend of deterioration from upstream to downstream, decreasing from a score of 6.5 in upstream areas (unimpacted) to a score of 4.4 in the downstream sites (moderately impacted). This result combined with a significant correlation of SIGNAL scores to habitat data suggested that habitat deterioration rather than polluted sediment was likely to be responsible for the declining stream condition detected with the rapid bioassessment approach. The addition of the microcosms to other monitoring approaches could be useful for determining whether sediment pollution is influencing degraded urban streams. Environ. Toxicol. Chem. 2010; 29:1773–1780. © 2010 SETAC
The Ichthyosaur Cemetery
Authors: Stinnesbeck Wolfgang , Frey Eberhard , Leppe Cartes Marcelo 
Published: May 2010

AbstractSome 120 million years ago, the ichthyosaurs died at the edge of the Tyndall Glacier. Now, palaeontologists are getting to the bottom of how such mass mortality in such a confined space came about – looking for clues in the Torres del Paine National Park in Chile
Design and characterization of PEGylated terpolymer biomaterials
Authors: Heath Daniel E. , Cooper Stuart L. 
Published: May 2010

AbstractA terpolymer copolymerized from hexyl methacrylate, methyl methacrylate, and poly(ethylene glycol) methacrylate (PEGMA) was synthesized. Polymers containing 0–25 mol % PEGMA were studied. As the mole fraction of PEGMA in the polymer chains increased, the material becomes more hydrophilic as observed by a decrease in the contact angle of water (81°–68°) and an increase in the equilibrium water absorption (0.7–237 wt %). Furthermore, the material shows nonfouling interfacial properties through resistance to protein adsorption and cellular attachment. A total of 1.2 μg/cm2 fibrinogen, 18,000 HUVECs/cm2, and 3,000,000 platelets/cm2 adsorbed or adhered on non‐PEGylated materials, whereas very low amounts of protein or cells were observed on materials containing ≥15 mol % PEGMA. Being thermoplastic, the polymer can be processed postsynthesis. To illustrate the processing capabilities of the material, polymer solutions were electrospun into nonwoven fibrous scaffold, which also retained their nonfouling character. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Oriented immobilization of anti‐CD34 antibody on titanium surface for self‐endothelialization induction
Authors: Li Quan‐Li , Huang Nan , Chen Cheng , Chen Jia‐Long , Xiong Kai‐Qin , Chen Jun‐Ying , You Tian‐Xue , Jin Jian , Liang Xin 
Published: May 2010

AbstractInducing spontaneous endothelialization of synthetic cardiovascular implant in vivo is thought to be a promising approach to solve the surface‐induced thrombosis and restenosis problem. In the present study, anti‐CD34 antibody, a kind of special marker of EPC, was oriented immobilized on titanium surface by means of a layer‐by‐layer self‐assembly coating technique. The multilayer coating was prepared by first depositing one layer of avidin on the NaOH‐treated titanium substrate, then depositing a layer of biotinylated protein A binding to the avidin, and finally anti‐CD34 antibody was oriented immobilized by protein A binding to the Fc fragment (COOH‐terminal of a antibody molecule, which has no antigen binding sites) of the anti‐CD34 antibody with its antigen binding fragment (Fab) away from the titanium surface. The coated titanium was exposed to EPC derived from mouse bone marrow in vitro, and implanted into dog femoral arteries. The results suggested that the anti‐CD34 antibody immobilized surfaces could increase EPC attachment and capture, and induce rapid complete endothelialization of the lumenal surface of the implant in vivo. It suggests that the approach described here may be used for fabrication of titanium‐based vascular implant surfaces for inducing endothelialization in vivo. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
GDF‐9 promotes the growth of prostate cancer cells by protecting them from apoptosis
Authors: Bokobza Sivan M. , Ye Lin , Kynaston Howard G. , Jiang Wen G. 
Published: May 2010

AbstractBone morphogenetic proteins (BMPs) have long been implicated in the process of prostate cancer progression and bone metastasis. This current study investigates the role of GDF‐9, a BMP member, in prostate cancer. GDF‐9 was over‐expressed in PC‐3 cells using a mammalian expression construct. Additionally, GDF‐9 ribozyme transgenes were generated in order to knock down the expression of GDF‐9 in PC‐3 and DU‐145 cells. These cells were then used in in vitro growth assays in order to determine the effect of GDF‐9 on prostate cancer cell growth. Recombinant GDF‐9 was also generated and used to treat both cell lines before carrying out further growth assays. Levels of apoptosis were subsequently analyzed using flow cytometry. Cell growth was significantly increased in the GDF‐9 over‐expressing cells compared to the two controls. The cell growth rate at day 5 was significantly greater in the PC‐3GDF‐9exp. (1,131.1 ± 79.1%) compared to both PC‐3WT (563.9 ± 90.6%) and PC‐3pEF (763.3 ± 82.0%), P ≤ 0.001 versus both controls. The opposite effect was seen in both PC‐3 and DU‐145 GDF‐9 knockdown cells. The PC‐3WT cells treated with rh‐GDF‐9 (1.35 ± 0.28) had a significantly increased absorbance and hence growth rate compared to the untreated PC‐3 cells (0.79 ± 0.05), P = 0.026. Finally, flow cytometry and Hoechst 33342 DNA staining demonstrated decreased apoptosis and caspase‐3 expression levels in PC‐3GDF‐9exp. cells and rh‐GDF‐9‐treated PC‐3WT cells. This study shows that GDF‐9 can promote the growth rate of both PC‐3 and DU‐145 cells by protecting the cells from caspase‐3‐mediated apoptosis, and suggests that GDF‐9 may aid in the progression of prostate cancer by acting as a survival factor. J. Cell. Physiol. 225: 529–536, 2010. © 2010 Wiley‐Liss, Inc.
Optimisation of lactic acid fermentation for improved vinegar flavour during rosy vinegar brewing
Authors: Jiang Yujian , Guo Jianna , Li Yudong , Lin Sen , Wang Li , Li Jianrong 
Published: May 2010

AbstractBACKGROUND: Rosy vinegar is a well‐known traditional Chinese product whose flavour is affected by its lactic acid content. In this study, Lactobacillus bacteria were employed to increase the content of lactic acid during the ethanol fermentation stage.RESULTS: The optimised fermentation parameters were determined as an inoculation amount of 3% (v/v), a temperature of 30 °C and an initial pH value of 4.0. Fermentation under these optimal conditions resulted in an alcohol degree of 6.2% (v/v), a total acidity of 49.5 g L−1 and a lactic acid content of 4.14 g L−1. The content of lactic acid (4.14 g L−1), which approached the level achieved by solid state fermentation, was 3.56‐fold higher than that in vinegar fermented without lactic acid bacteria (1.16 g L−1).CONCLUSION: The results indicate that mixed fermentation with Lactobacillus plantarum and Saccharomyces cerevisiae strains greatly increases the lactic acid content and improves the flavour of rosy vinegar. Copyright © 2010 Society of Chemical Industry
Computational analysis of unassigned high‐quality MS/MS spectra in proteomic data sets
Authors: Ning Kang , Fermin Damian , Nesvizhskii Alexey I. 
Published: May 2010

AbstractIn a typical shotgun proteomics experiment, a significant number of high‐quality MS/MS spectra remain “unassigned.” The main focus of this work is to improve our understanding of various sources of unassigned high‐quality spectra. To achieve this, we designed an iterative computational approach for more efficient interrogation of MS/MS data. The method involves multiple stages of database searching with different search parameters, spectral library searching, blind searching for modified peptides, and genomic database searching. The method is applied to a large publicly available shotgun proteomic data set.