bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Crystalline Carbon Nitride Nanocone Arrays by Direct‐Current Discharge Plasma‐Assisted CVD
Authors: Hu Wei , Xu Ning , Xu Xiaofeng , Wu Jiada , Shen Yiqun , Ying Zhifeng 
Published: December 2009

AbstractCrystalline carbon nitride nanocone (CNNC) arrays are prepared by a rather simple and facile direct current, abnormal glow discharge plasma‐assisted (PA) CVD method. The CNNCs are grown on the surfaces of (100) silicon wafers covered by Co/Ni intermediate layers. The experiments are carried out in an atmosphere of mixtures of methane and nitrogen, under a total pressure of 4000 Pa, and CH4/N2 pressure ratios in the range 1:50–1:5. The as‐grown CNNCs are vertically aligned in arrays with rather perfect crystallinity, and smallest tip diameters of 2–3 nm. Based on the optical emission spectra from the abnormal glow discharge plasma, the growth mechanism of the as‐grown CNNCs is discussed.
Reactions of Unsaturated Nickel–Molybdenum and –Tungsten Complexes with Primary Amines: Chemoselective N‐Coordination to Nickel To Give the First Structurally Characterised Primary Amine–Organonickel Complexes
Authors: Carmona Carmen Cuncillos , Clapham Sarah , Gonidec Mathieu , Ritleng Vincent , Braunstein Pierre , Welter Richard , Chetcuti Michael J. 
Published: December 2009

AbstractThe reactions of selected primary amines with the unsaturated heterodimetallic complex [(η‐C5Me5)Ni(μ‐CO)Mo(CO)2(η‐C5H5)](Ni[pb2]Mo) (1a) were investigated. Primary aminesreact with this heterodimetallic complex to form unstable adducts, which are in equilibrium with the free amine and complex 1a in solution. Complex 1b, the nickel–tungsten analogue of 1a, reacts similarly with benzylamine. The position of the equilibrium shifts in favour of the adducts at low temperature, and crystals of the allylamine and benzylamine complexes [(η‐C5Me5)(RNH2)Ni–Mo(CO)3(η‐C5H5)], (2a, R = C3H5; 4a, R = PhCH2) could be isolated. Their structures were established by single‐crystal X‐ray diffraction studies. The primary amines in complexes 2a and 4a are each coordinated, by means of their respective nitrogen atoms, to the nickel atom and thus provide the first structurally characterised examples of primary amine organometallic nickel complexes. The bonding of the amine to the heterodimetallic centre is in contrast to what has been observed with phosphorus‐containing 2‐electron donor ligands, in which the phosphane ligand is coordinated to the group 6 metal atom. A measure of the Ni–N bond dissociation enthalpy for the (benzylamine)nickel–tungsten complex 4b was obtained from a VT 1H NMR spectroscopic study and was found to be –149 ± 10 kJ mol–1. N‐Bonded hydrogen atoms in both 2a and 4a exhibit intermolecular hydrogen‐bonding interactions in the solid state with carbonyl oxygen atoms of adjacent molecules. These molecules exist as loosely bound dimers in the solid state. Complex 2a (C21H27MoNNiO3) crystallises in the monoclinic space group P21/n with a = 10.1922(2), b = 11.1538(3), c = 18.8053(4) Å, β = 90.777(2)° and Z = 4. Complex 4a (C25H29MoNNiO3) also crystallises in the monoclinic space group P21/n with a = 12.0840(4), b = 10.9490(4), c = 17.4930(6) Å, β = 90.396(3)° and Z = 4.
Fullerene Unsymmetrical Bis‐Adducts as Models for Novel Peptidomimetics
Authors: Milic Dragana , Prato Maurizio 
Published: December 2009

AbstractTwo classes of unsymmetrical, orthogonally protected bis‐fulleropyrrolidine amino acids have been prepared as models for fullerene‐based peptidomimetics with the carbon sphere inserted into the peptide backbone. Two successive [3+2]cycloadditions of azomethine ylides (thermally generated from formaldehyde and the corresponding orthogonally protected glycino‐amines and ‐acids) to C60 afforded NHFmoc/CO2tBu and NHBoc/CO2Me fulleropyrrolidine couples, offering the possibility of selective deprotection under both acidic and basic conditions. In both classes of unsymmetrical bis‐adducts, the distribution of all the trans (t1–t4) and equatorial (e′ and e″) isomers was quite similar except for the t3 NHBoc/CO2Me compound, which rapidly decomposed during chromatography. All compounds were characterized by UV/Vis, 1H and 13C NMR spectroscopy, and mass spectrometry.
Keronopsamides, a New Class of Pigments from Marine Ciliates
Authors: Guella Graziano , Frassanito Rita , Mancini Ines , Sandron Tommaso , Modeo Letizia , Verni Franco , Dini Fernando , Petroni Giulio 
Published: December 2009

AbstractNew pigments with an unprecedented skeleton, named keronopsamides A–C, were isolated from the marine ciliate Pseudokeronopsis riccii. The structure of the most abundant secondary metabolite, keronopsamide A, was established through extended Nuclear Magnetic Resonance (NMR) analysis and mass spectrometric (MS) data obtained by using electrospray (ESI) and matrix assisted laser desorption (MALDI) ionizations. Structures of the minor analogues (keronopsamide B and C) were inferred from 1H NMR, chemical correlation, and LC‐MS measurements. The analysis of NOE dipolar couplings and quantum chemical calculations, carried out by density functional theory (DFT) on the preferred rotamers of keronopsamide A, suggested a fully planar structure with amide bond in anti stereochemistry capable to break down the extended conjugation of the whole π electronic system. Although the presence of a 2‐substituted 3,4‐dibromo‐pyrrole moiety is reminiscent of previously isolated metabolites isolated from a cell extract of Pseudokeronopsis rubra (keronopsins), keronopsamides show a new molecular skeleton formally derived from a peptide‐like condensation of a 3‐pyrrolepropenoic acid with an unsaturated bromotyramine.
Enhancing the Reactivity of an Electrophilic Barbiturate Dye by Cooperative Hydrogen Bonding
Authors: Bauer Mirko , Spange Stefan 
Published: December 2009

AbstractThe supramolecular complex formation by cooperativehydrogen bonding of a highly dipolar barbiturate dye and 2,6‐diacetamidopyridine is shown to have a marked effect on the reactivity of the barbiturate. The increase of both Lewis acidity and electrophilicity by hydrogen bonding is demonstrated by thermodynamic and kinetic studies using the electrophile–nucleophile recombination reaction with cyanide.
A Water‐Soluble Cyclic Selenide with Enhanced Glutathione Peroxidase‐Like Catalytic Activities
Authors: Kumakura Fumio , Mishra Beena , Priyadarsini K. Indira , Iwaoka Michio 
Published: December 2009

AbstractAntioxidative catalytic activities of trans‐3,4‐dihydroxyselenolane (DHSred), a water‐soluble cyclic selenide, were investigated in the reaction of hydrogen peroxide with three different thiol substrates, monothiol glutathione (GSH), dithiol dithiothreitol (DTTred), and polythiol reduced ribonuclease A (RNase A) having eight thiol groups along the polypeptide chain. For all the thiol substrates, DHSred exhibited higher glutathione peroxidase (GPx)‐like antioxidative catalytic activities than the corresponding linear selenide, that is, Se(CH2CH2OH)2. The rate‐determining step of the catalytic cycle was unambiguously assigned to the oxidation process of the selenide rather than the reduction process of the selenoxide intermediate. The enhanced catalytic activities of DHSred can be ascribed to the cyclic structure, which elevates the HOMO energy level and makes the selenium atom more exposed to the surroundings.
Bezerramycins A–C, Antiproliferative Phenoxazinones from Streptomyces griseus Featuring Carboxy, Carboxamide or Nitrile Substituents
Authors: Gomes Patrícia Bezerra , Nett Markus , Dahse Hans‐Martin , Sattler Isabel , Martin Karin , Hertweck Christian 
Published: December 2009

AbstractThree new phenoxazinone antibiotics, named bezerramycins A–C (1–3), were isolated from a Streptomyces griseus strain (HKI 0545, DSM 41823) together with the known metabolite elloxazinone B (4). Their structures were elucidated by one‐ and two‐dimensional NMR techniques (1H, 13C, HSQC, 1H‐1H COSY and HMBC) as well as mass spectrometry. One of the isolated phenoxazinones (bezerramycin C) features a nitrile moiety, which is scarce in natural products. All compounds were evaluated for their antiproliferative and cytotoxic activities. Those featuring a hydroxymethyl substituent at C‐8 were found to exhibit moderate antiproliferative properties against vascular endothelium cells (HUVEC) (GI50 = 14.5–20 μM). A biosynthetic model for the isolated compounds is discussed.
Poly(2‐ethyl‐2‐oxazoline) as a sieving matrix for SDS‐CE
Authors: Bernard Richard , Loge Gary 
Published: December 2009

AbstractThe use of poly(2‐ethyl‐2‐oxazoline) with a number‐average molecular weight (of polymer) of 500 000 g/mol in a sieving matrix for SDS CE size separation of proteins is investigated using polymer solutions with concentrations between 6 and 12% w/v. Optimal separation efficiency is obtained using 10% w/v, with an average separation efficiency of 150 000 (12 000) theoretical plates observed for myoglobin (weight‐average molecular weight=18 kDa) and 8 800 000 (2 400 000) theoretical plates for carbonic anhydrase (weight‐average molecular weight=30 kDa) for 14 capillaries with an 80 cm effective length. Some adsorbed polymers were found to be effective in reducing EOF when applied to a clean capillary; however, a covalently attached polyacrylamide coating was found to be much less troublesome after initial wall treatment. Two different buffer systems, (i) 25 mM HEPES and (ii) 20 mM Tris with 40 or 60 mM tricene, were tried with 0.05 or 0.10% w/v SDS added. Tris‐tricene gave generally better current stability than HEPES but with no observed improvement in separation efficiency. This polymer has all the desired characteristics for an SDS‐CE sieving matrix using LIF detection, including hydrolytic stability, optical clarity, low viscosity, acceptable hydrophilicity, and commercial availability.
Multiplex microsphere‐based flow cytometric platforms for protein analysis and their application in clinical proteomics – from assays to results
Authors: Hsu Hsin‐Yun , Joos Thomas O. , Koga Hisashi 
Published: December 2009

AbstractAdvances in high‐throughput screening, together with rapid progress in genomic and proteomic sciences, have considerably stimulated the development of a variety of biomarker discovery tools and have contributed to the improvement of clinical diagnosis. Major challenges include the obtaining of high‐quality data sets based on assays that are rapid, reliable, and inexpensive, but still highly sensitive and easy to perform. The microsphere‐based flow cytometric technology is a platform that is currently entering the diagnostic market. This article reviews the development and the applications of microsphere‐based flow cytometric platforms in basic and applied proteomic research, and discusses bead‐based assays used in clinical applications.
Recent advances in capillary electrophoresis‐based proteomic techniques for biomarker discovery
Authors: Fang Xueping , Balgley Brian M. , Lee Cheng S. 
Published: December 2009

AbstractA compelling need exists for the development of technologies that facilitate and accelerate the discovery of novel protein biomarkers with therapeutic and diagnostic potential. The inherent disadvantage of biomarker dilution in complex biological fluids such as serum/plasma, urine, and saliva necessitates highly sensitive analytical approaches, often exceeding the dynamic range of currently available proteomic platforms. Thus, investigative studies directed at tissues obtained from the primary site of pathology probably afford the best opportunity for the discovery of disease biomarkers. This review therefore focuses on the most recent advances in capillary electrophoresis‐based single and multidimensional separations coupled with ESI‐MS for performing comprehensive and comparative analysis of protein expression profiles within clinical specimens. Advanced sample preparation techniques, including tissue microdissection, detergent‐based membrane protein extraction, and heat‐induced protein retrieval, further enable targeted protein profiling of both fresh‐frozen, formalin‐fixed, and paraffin‐embedded tissues. Comparative proteomics involving measurements in changes of biological pathways or functional processes are expected to provide relevant disease‐associated markers and networks, molecular relationships among different stages of disease, and molecular mechanisms that drive the progression of disease. From a practical perspective, the evaluation of comparative proteomic dataset within a biological context is essential for high‐throughput data validation, prioritization of follow‐on biomarker selection, and validation experiments.
Comparison of multidimensional shotgun technologies targeting tissue proteomics
Authors: Fang Xueping , Balgley Brian M. , Wang Weijie , Park Deric M. , Lee Cheng S. 
Published: December 2009

AbstractA compelling need exists for the development of technologies that facilitate and accelerate the discovery of novel protein biomarkers with therapeutic and diagnostic potential. Comparisons among shotgun proteome technologies, including capillary isotachophoresis (CITP)‐based multidimensional separations and multidimensional LC system, are therefore performed in this study regarding their abilities to address the challenges of protein complexity and relative abundance inherent in glioblastoma multiforme‐derived cancer stem cells. Comparisons are conducted using a single processed protein digest with equal sample loading, identical second‐dimension separation (RPLC) and MS conditions, and consistent search parameters and cutoff established by the target‐decoy determined false‐discovery rate. Besides achieving superior overall proteome performance in total peptide, distinct peptide, and distinct protein identifications; analytical reproducibility of the CITP proteome platform coupled with the spectral counting approach are determined by a Pearson R2 value of 0.98 and a CV of 15% across all proteins quantified. In contrast, extensive fraction overlapping in strong cation exchange greatly limits the ability of multidimensional LC separations for mining deeper into the tissue proteome as evidenced by the poor coverage in various protein functional categories and key protein pathways. The CITP proteomic technology, equipped with selective analyte enrichment and ultrahigh resolving power, is expected to serve as a critical component in the overall toolset required for biomarker discovery via shotgun proteomic analysis of tissue specimens.
Hunting down fungal secretomes using liquid‐phase IEF prior to high resolution 2‐DE
Authors: Vincent Delphine , Balesdent Marie‐Hélène , Gibon Julien , Claverol Stéphane , Lapaillerie Delphine , Lomenech Anne‐Marie , Blaise Françoise , Rouxel Thierry , Martin Francis , Bonneu Marc , Amselem Joëlle , Dominguez Victoria , Howlett Barbara J. , Wincker Patrick , Joets Johann , Lebrun Marc‐Henri , Plomion Christophe 
Published: December 2009

AbstractThe secreted proteins (secretome) of fungi play a key role in interactions of pathogenic and symbiotic fungi with plants. Using the plant pathogenic fungus Leptosphaeria maculans and symbiont Laccaria bicolor grown in culture, we have established a proteomic protocol for extraction, concentration and resolution of the fungal secretome. As no proteomic data were available on mycelium tissues from both L. maculans and L. bicolor, mycelial proteins were studied; they also helped verifying the purity of secretome samples. The quality of protein extracts was initially assessed by both 1‐DE and 2‐DE using first a broad pH range for IEF, and then narrower acidic and basic pH ranges, prior to 2‐DE. Compared with the previously published protocols for which only dozens of 2‐D spots were recovered from fungal secretome samples, up to approximately 2000 2‐D spots were resolved by our method. MS identification of proteins along several pH gradients confirmed this high resolution, as well as the presence of major secretome markers such as endopolygalacturonases, β‐glucanosyltransferases, pectate lyases and endoglucanases. Shotgun proteomic experiments evidenced the enrichment of secreted protein within the liquid medium. This is the first description of the proteome of L. maculans and L. bicolor, and the first application of liquid‐phase IEF to any fungal extracts.
Deciphering the proteomic profile of rice (Oryza sativa) bran: A pilot study
Authors: Ferrari Fabio , Fumagalli Marco , Profumo Antonella , Viglio Simona , Sala Alberto , Dolcini Lorenzo , Temporini Caterina , Nicolis Stefania , Merli Daniele , Corana Federica , Casado Begona , Iadarola Paolo 
Published: December 2009

AbstractThe exact knowledge of the qualitative and quantitative protein components of rice bran is an essential aspect to be considered for a better understanding of the functional properties of this resource. Aim of the present investigation was to extract the largest number of rice bran proteins and to obtain their qualitative characterization. For this purpose, three different extraction protocols have been applied either on full‐fat or on defatted rice bran. Likewise, to identify the highest number of proteins, MS data collected from 1‐DE, 2‐DE and gel‐free procedures have been combined. These approaches allowed to unambiguously identify 43 proteins that were classified as signalling/regulation proteins (30%), proteins with enzymatic activity (30%), storage proteins (30%), transfer (5%) and structural (5%) proteins. The fact that all extraction and identification procedures have been performed in triplicate with an excellent reproducibility provides a rationale for considering the platform of proteins shown in this study as the potential proteome profile of rice bran. It also represents a source of information to evaluate better the qualities of rice bran as food resource.
Development of a microfluidics‐based gel protein recovery system
Authors: Razunguzwa Trust Tariro , Biddle April , Anderson Heather , Zhan Dongliang , Powell Matthew 
Published: December 2009

AbstractA PMMA microfluidic chip, in which fluid is manipulated to transport protein from a PAGE gel piece to a collection reservoir via a microfluidic channel, has been developed. The protein sample is mobilized out of the gel (loaded in a chip access hole) into a low EOF‐CE microfluidic channel under the influence of an electric field. Simultaneously, hydrostatic pressure from the filled buffer reservoirs is used to direct the protein sample to a third reservoir, through a field‐free channel connected to the electrophoresis channel. Using this novel process of protein transport from a gel sample, proteins from Coomassie‐stained gels have been transferred into solution in 15–30 min, with good sample recovery, using a run buffer containing an anionic acid‐labile surfactant. A variety of small‐ and medium‐sized proteins were successfully recovered and detected using both electrospray and MALDI MS over gel loads of 0.1–10 μg. This technological tool is very important for extracting quality intact protein samples from polyacrylamide gels, from which accurate protein molecular weights and protein sequences can be obtained using intact molecules.
A Finite Element Approach for the Modelling of Skeletal Muscle Fatigue
Authors: Böl M. , Reese S. 
Published: December 2009

AbstractSkeletal muscles are the primary unit for the movement of the human body, they serve as shock absorber and protect the skeleton system against external loads. By maintaining a certain force level, muscle show fatigue effects, expressed by a decrease of the retentive force. To incorporate such effects in a finite element framework, we use a fatigue model that allows us to describe the dynamical processes between active, fatigued, and recovered fibres. The chosen modelling strategy facilitates the efficient transport of the known information about physiological processes in the single fibre to the three‐dimensional macroscopic level where e. g. the dependence of muscle contraction on fatigue effects is studied. Besides the theoretical derivation of the modelling approach, simulations at fibre as well as at muscle level have been investigated (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Impact of the virtual reality on the neural representation of an environment
Authors: Mellet Emmanuel , Laou Laetitia , Petit Laurent , Zago Laure , Mazoyer Bernard , Tzourio‐Mazoyer Nathalie 
Published: December 2009

AbstractDespite the increasing use of virtual reality, the impact on cerebral representation of topographical knowledge of learning by virtual reality rather than by actual locomotion has never been investigated. To tackle this challenging issue, we conducted an experiment wherein participants learned an immersive virtual environment using a joystick. The following day, participants' brain activity was monitored by functional magnetic resonance imaging while they mentally estimated distances in this environment. Results were compared with that of participants performing the same task but having learned the real version of the environment by actual walking. We detected a large set of areas shared by both groups including the parieto‐frontal areas and the parahippocampal gyrus. More importantly, although participants of both groups performed the same mental task and exhibited similar behavioral performances, they differed at the brain activity level. Unlike real learners, virtual learners activated a left‐lateralized network associated with tool manipulation and action semantics. This demonstrated that a neural fingerprint distinguishing virtual from real learning persists when subjects use a mental representation of the learnt environment with equivalent performances. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.
Professionalism and the know‐do gap: exploring intrinsic motivation among health workers in Tanzania
Authors: Leonard Kenneth L. , Masatu Melkiory C. 
Published: December 2009

AbstractProfessionalism can be defined generally as adhering to the accepted standards of a profession and placing the interests of the public above the individual professional's immediate interests. In the field of medicine, professionalism should lead at least some practitioners in developing countries to effectively care for their patients despite the absence of extrinsic incentives to do so. In this study we examine the behavior of 80 practitioners from the Arusha region of Tanzania for evidence of professionalism. We show that about 20% of these practitioners behave professionally, and almost half of those who do so practice in the public sector. These professional health care workers provide high quality care even when they work in an environment that does not reward this effort, a finding that has important implications for the use of performance‐based incentives. Copyright © 2009 John Wiley & Sons, Ltd.