bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Properties of Dendronized Chitosan
Authors: Aldana Ana Agustina , Martinelli Marisa , Strumia Miriam 
Published: January 2011

AbstractSummary: Chitosan films and microspheres were prepared and their surfaces were functionalized with first generation dendritic molecules. The films were modified by Weisocyanate dendron, while Behera's and bis Behera's amine dendrons were used to modify the microspheres. Prior to dendronization films were prepared by blending chitosan with 18% of polyvinyl pyrrolidone (PVP), and casting the resulting mixture. The degree of dendronization reached was 28%. The microspheres were prepared by coacervation/precipitation, after which the surfaces were activated with either epychlorohydrine (ECH) or 1,4‐butanediol diglycidyl ether (BDGE). The oxirane groups were utilized to form covalent bonds between chitosan and dendrons. The degree of dendronization yielded with Behera's amine was 60% for both activating agents. When bis Behera's amine was used, the dendronization reached values of 15 and 21% when ECH or BDGE were used, respectively. The dendronized products were characterized through spectroscopic and microscopic studies and by determination of swelling indexes. Only one of the surfaces was dendronized in every film, which therefore presented a hydrophobic and a hydrophilic surface. Since these films maintain the properties of chitosan, they offer interesting potential as dressings for exuding wounds. The different surfaces make the microspheres potentially applicable as carriers for delivery and controlled release of drugs.
Separation of Poly(propylene) Samples According to Tacticity Using a Hypercarb Column
Authors: Macko Tibor , Cutillo Francesco , Busico Vincenzo , Brüll Robert 
Published: January 2011

AbstractSummary: Samples of polypropylene having different stereoregularities, i.e., differing in the isotactic or syndiotactic stereosequence distribution, were separated by means of high‐temperature gradient adsorption liquid chromatography. The porous graphite was used as stationary phase in the column packing (Hypercarb®). Predominantly isotactic samples eluted in 1‐decanol, while predominantly syndiotactic samples eluted in a binary gradient composed of 1‐decanol and 1,2,4‐trichlorobenzene. Their elution volumes increased with the average content of the syndiotactic units (racemo dyads mole fraction as determined with the NMR spectroscopy) in the samples. Thus these chromatographic separations represent a new method for the analysis and characterization of stereoregular polyolefins. It requires substantially less time and solvents than the commonly used methods.
Dynamic Viscosity of PEG:PEG‐ran‐PPG Blends through Stress Relaxation
Authors: Das Ashok K. , Hsu Di‐Yao , Hong Po‐Da 
Published: January 2011

AbstractDensities and viscosities of a series of blends of poly(ethylene glycol) (PEG) and poly(ethylene glycol‐ran‐propylene glycol) (PEG‐ran‐PPG) were measured at a temperature above the melting point. The density and viscosity data were fitted with analytical functions involving the volume fraction of PEG,ϕPEG. Stress relaxation curves for the pure components and blends were obtained through Monte Carlo (MC) simulations. A typical stress relaxation curve exhibits a fast mode that represents energetic‐interactions‐driven motion and a slow mode that originates from the entropy‐driven motion. Flory–Huggins interaction parameters (χ) for the blends are much smaller than the critical values (χcritical). The calculation ofχandχcriticalprovides important clues for polymer blend processing.magnified image
Oil supply projection techniques: Past developments and future requirements
Authors: Bruce Alistair 
Published: January 2011

AbstractThis paper presents a critical assessment of the development of economic models of oil supply projection over the last two decades. The survey illustrates the fact that although most models have stressed the significance of the economic variables in the supply function, few attempts have been made to incorporate technology as a variable. Although such an approach can be justified under certain special circumstances, it is considered unsuitable as a supply forecaster in the increasingly numerous marginal fields where operations approach the technology frontier. In this connection, the latter part of the paper discusses the possibility of and problems associated with incorporating technology as a variable in the projection of supply.
Se‐methylselenocysteine inhibits lipopolysaccharide‐induced NF‐κB activation and iNOS induction in RAW 264.7 murine macrophages
Authors: Pan Min‐Hsiung , Hong Huei‐Mei , Lin Chih‐Li , Jhang Ai‐Zhi , Tsai Jie‐Heng , Badmaev Vladimir , Nagabhushanam Kalyanam , Ho Chi‐Tang , Chen Wei‐Jen 
Published: January 2011

AbstractScope: Se‐methyl‐L‐selenocysteine (MSC), a naturally occurring organoselenium compound, has shown cancer chemopreventive activity against several types of cancer. Herein, the effect of MSC on the inflammatory response in lipopolysaccharide (LPS)‐activated murine RAW 264.7 macrophage cells was investigated.Methods and results: The present results demonstrated that MSC markedly inhibited LPS‐induced production of NO in a dose‐dependent pattern with decreased mRNA and protein levels of inducible nitric oxide synthase (iNOS). MSC also reduced nuclear translocation of p65 and p50 subunits of nuclear factor‐κB (NF‐κB), a critical transcription factor necessary for iNOS expression, accompanied with downregulation of LPS‐triggered NF‐κB‐dependent gene expression evaluating by a luciferase reporter. Inhibition of nuclear translocation by MSC might result from the prevention of the inhibitor of NF‐κB from phosphorylation and consequent degradation via suppression inhibition of phosphorylation of IκB kinase α/β. Exploring the action mechanism involved, MSC can reduce the phosphorylation/activation of mitogen‐activated protein kinases (MAPKs) related to NF‐κB activation induced by LPS, including p38 MAPK and c‐Jun N‐terminal kinase in RAW 264.7 cells.Conclusion: MSC might contribute to the potent anti‐inflammatory effect in LPS‐activated RAW 264.7 cells via downregulation of NF‐κB activation and iNOS expression, suggesting that MSC may be considered as a therapeutic candidate for chronic inflammatory diseases.
BIRD‐J‐resolved HMBC and BIRD‐high‐resolution HMBC pulse sequences for measuring heteronuclear long‐range coupling constants and proton–proton spin coupling constants in complicated spin systems
Authors: Furihata Kazuo , Tashiro Mitsuru , Seto Haruo 
Published: January 2011

AbstractEfficient pulse sequences for measuring long‐range CH coupling constants (JCH) and proton‐proton spin coupling constants (JHH), named BIRD‐J‐resolved HMBC and BIRD‐high‐resolution HMBC, respectively, have been developed. In spin systems possessing a secondary methyl group positioned between protonated carbons (e.g.CH2CH(CH3)CH2), the methine proton splits in a complicated fashion, resulting in difficulty in the determination of its spin coupling constants. For easy and accurate measurements of the long‐range JCH and JHH in such a spin system, the BIRD pulse [90°x(H)− 180°x (H/C)− 90° (−x)(H)] or [90°x(H)− 180°x(H/C)− 90° (−x)(H)180°x(C)] is incorporated into the J‐resolved portion of the pulse sequence. As a result, the above secondary methyl group can be selectively decoupled, providing simplified cross‐peak patterns, which are suitable for the accurate measurements of the long‐range JCH and JHH. Copyright © 2010 John Wiley & Sons, Ltd.
An EPR analysis of β‐dimerization in α‐blocked pyrroles in oxidant conditions
Authors: Julià Luis , Rius Jordi , Torrelles Xavier 
Published: January 2011

AbstractElectron paramagnetic resonance (EPR) analysis of neutral and acidic solutions of 2,5‐dimethyl‐1‐phenylpyrrol (1) and meta‐, para‐, and ortho‐bis(2,5‐dimethylpyrrol‐1‐yl)benzenes (4–6) in the presence of Tl(III) trifluoroacetate as oxidant reveals the poor stability of their generated monomeric radical cations which dimerize through C(β)C(β) bond formation. EPR spectra of the monomeric radical cations 4•+, 5•+, and 6•+ coincide with that of 1•+, suggesting that the unpaired electron in these charged species is confined in one of the pyrrolic rings. The very twisted angles between pyrrolic and phenyl planes due to steric hindrance in the X‐ray analysis of the molecular structure of 4 confirm the absence of extended conjugation in the π‐system. Copyright © 2011 John Wiley & Sons, Ltd.
Polymer‐bound 4‐methylcoumarin/1‐heptanoyl‐5‐fluorouracil photodimers: NMR elucidation of dimer structure
Authors: Sinkel Carsten , Schwarzer Martin C. , Frenking Gernot , Greiner Andreas , Agarwal Seema 
Published: January 2011

AbstractHeterodimers based on the polymer‐bound chromophore 4‐methylcoumarin and the prodrug 1‐heptanoyl‐5‐fluorouracil, synthesized by photochemical [2 + 2]‐cycloaddition are promising photoresponsive drug depots. Drug release experiments are one possibility to deliver proof of a successful reversible drug immobilization, whereas NMR spectroscopy is a potent tool for further structural characterization of these polymer‐bound heterodimers. In case of the random copolymer poly(methyl methacrylate‐co‐7‐(2′‐methacryloyloxyethoxy)‐4‐methylcoumarin) three dimers have been identified of which the syn head‐to‐tail was the predominant one. In contrast, only the syn head‐to‐head dimer was formed in reasonable yield when the 4‐methylcoumarin monofunctionalized pMMA was used as the base polymer. 1D and 2D NMR spectroscopic techniques combined with some theoretical calculations helped in successfully closing one major gap concerning polymer bound 4‐methylcoumarin/1‐heptanoyl‐5‐fluorouracil heterodimers that are of potential use in photoresponsive drug delivery devices. Copyright © 2011 John Wiley & Sons, Ltd.
Perinatal outcome of prenatally diagnosed congenital talipes equinovarus
Authors: Sharma Rowena , Stone Stephanie , Alzouebi Aisha , Hamoda Haitham , Kumar Sailesh 
Published: January 2011

AbstractObjectiveThe purpose of this study was to investigate the perinatal outcome of prenatally diagnosed congenital talipes equinovarus.MethodsThis was a retrospective observational study of all cases of prenatally diagnosed congenital talipes equinovarus referred to a major tertiary fetal medicine unit. Cases were identified from the fetal medicine and obstetric databases and pregnancy details and delivery outcome data obtained. Details of termination of pregnancy, number of patients undergoing karyotyping as well as details of prenatal classification of severity were recorded.ResultsA total of 174 cases were identified. Of these, outcome data was available for 88.5% (154/174) of the pregnancies. Eighty three (47.7%) of cases were isolated and 91 cases (52.3%) were associated with additional abnormalities. There was a significant difference in birth weights between the two cohorts. Bilateral abnormality tended to be more severe. A high caesarean section rate was noted overall and a high preterm delivery rate seen in the isolated group.ConclusionThis study is important because it provides contemporary data that can be used to counsel women prenatally. In particular, the raised risk of preterm delivery and caesarean section as well as the increased severity of the condition when both feet are affected should be discussed. The poor perinatal outcome when additional anomalies are present and the increased risk of aneuploidy are also important factors. Copyright © 2011 John Wiley & Sons, Ltd.
Uncertainty of the spectral mismatch correction factor in STC measurements on photovoltaic devices
Authors: Hohl‐Ebinger Jochen , Warta Wilhelm 
Published: January 2011

AbstractValuation of photovoltaic devices depends strongly on the measured power output of the device. This quantity is usually determined under artificial sunlight in production line measurement systems or industrial or research test labs. A practical calibration chain is realized essentially with measurements at solar simulators. The measurement conditions are defined in the IEC 60904 series of standards. An important part of the standard testing conditions is the definition of a specific spectral distribution of the sunlight (AM1.5 global). The inevitable deviations of the spectrum of artificial light sources from the standard spectrum have to be taken into account by a spectral mismatch factor. The uncertainty of this crucial correction is spectrally dependent, in most cases unknown and complex and inconvenient to evaluate. In this article a randomizing method is proposed which allows one to calculate the uncertainty of the mismatch factor from the uncertainties of the input parameters determined with high spectral resolution. Based on a range of different spectral responses of solar cells on the one hand and variations of the solar simulator spectral distribution on the other, we are able to generalize the results to a broad set of measurement configurations. A sensitivity analysis reveals the crucial wavelength regions and thus allows the systematic optimization of simulator spectra and selection of reference cells. Copyright © 2010 John Wiley & Sons, Ltd.
Proteomic profiling of cerebrospinal fluid identifies prostaglandin D2 synthase as a putative biomarker for pediatric medulloblastoma: A pediatric brain tumor consortium study
Authors: Rajagopal Meena U. , Hathout Yetrib , MacDonald Tobey J. , Kieran Mark W. , Gururangan Sri , Blaney Susan M. , Phillips Peter , Packer Roger , Gordish‐Dressman Heather , Rood Brian R. 
Published: January 2011

AbstractThe aims of this study were to demonstrate the feasibility of centrally collecting and processing high‐quality cerebrospinal fluid (CSF) samples for proteomic studies within a multi‐center consortium and to identify putative biomarkers for medulloblastoma in CSF. We used 2‐DE to investigate the CSF proteome from 33 children with medulloblastoma and compared it against the CSF proteome from 25 age‐matched controls. Protein spots were subsequently identified by a combination of in‐gel tryptic digestion and MALDI‐TOF TOF MS analysis. On average, 160 protein spots were detected by 2‐DE and 76 protein spots corresponding to 25 unique proteins were identified using MALDI‐TOF. Levels of prostaglandin D2 synthase (PGD2S) were found to be six‐fold decreased in the tumor samples versus control samples (p<0.00001). These data were further validated using ELISA. Close examination of PGD2S spots revealed the presence of complex sialylated carbohydrates at residues Asn78 and Asn87. Total PGD2S levels are reduced six‐fold in the CSF of children with medulloblastoma most likely representing a host response to the presence of the tumor. In addition, our results demonstrate the feasibility of performing proteomic studies on CSF samples collected from patients at multiple institutions within the consortium setting.
Proteome analysis of Fusarium head blight in grains of naked barley (Hordeum vulgare subsp. nudum)
Authors: Eggert Kai , Pawelzik Elke 
Published: January 2011

AbstractThe effect of artificial Fusarium graminearum and F. culmorum infection at the level of the proteome on grains of naked barley (Hordeum vulgare subsp. nudum) was investigated in comparison to naturally infected samples. Fusarium infection in barley led to numerous host‐specific biochemical responses. NEPHGE 2‐D PAGE and MS were used to identify proteins that were differentially expressed in response to fungal infection and growing location of the plants. Moreover, the mycotoxin concentration of the grains was evaluated to characterize the infection degree. Inoculation of naked barley with Fusarium led to grain deoxynivalenol concentrations of up to 1.2 mg/kg. The carbon and nitrogen grain concentrations were not significantly changed after fungal infection, but differed between growing locations. Eleven proteins related to fungal infection were detected as were three proteins with effects based on growing location. These proteins belong to different protein groups involved in various cell functions: transcription regulation, defence response, nutrient reservoirs and starch biosynthesis. The results gave indications on plant defence strategies and changes as response to Fusarium infection in mature grains after a long infection period as well as being influenced by the growing location.
Application of 2‐D DIGE to formalin‐fixed, paraffin‐embedded tissues
Authors: Tanca Alessandro , Pagnozzi Daniela , Falchi Giovanni , Tonelli Roberto , Rocca Stefano , Roggio Tonina , Uzzau Sergio , Addis Maria Filippa 
Published: January 2011

AbstractThe ability to investigate the proteome of formalin‐fixed, paraffin‐embedded (FFPE) tissues can be considered a major recent achievement in the field of clinical proteomics. However, gel‐based approaches to the investigation of FFPE tissue proteomes have lagged behind, mainly because of insufficient quality of full‐length protein extracts. Here, the 2‐D DIGE technology was investigated for applicability to FFPE proteins, for internal reproducibility among replicate FFPE extracts, and for comparability between FFPE and fresh‐frozen tissue profiles. The 2‐D DIGE patterns obtained upon labeling and electrophoresis of replicate FFPE tissue extracts were highly reproducible, with satisfactory resolution and complexity. Moreover, the implementation of DIGE enabled to highlight and characterize the consistent differences found in the FFPE profiles compared with fresh‐frozen profiles, represented by an acidic shift, directly correlated to the protein pI value, and by a reduction in spot signal intensity, directly correlated to molecular weight and percentage of lysine residues. Being constantly and reproducibly present in all FFPE tissue extract replicates at similar extents, these modifications do not appear to hinder the comparative analysis of FFPE tissue extracts by 2‐D DIGE, opening the way to its application for the differential proteomic investigation of archival tissue repositories.
Catch me if you can: Mass spectrometry‐based phosphoproteomics and quantification strategies
Authors: Eyrich Beate , Sickmann Albert , Zahedi René Peiman 
Published: January 2011

AbstractPhosphorylation of proteins is one of the most prominent PTMs and for instance a key regulator of signal transduction. In order to improve our understanding of cellular phosphorylation events, considerable effort has been devoted to improving the analysis of phosphorylation by MS‐based proteomics. Different enrichment strategies for phosphorylated peptides/proteins, such as immunoaffinity chromatography (IMAC) or titanium dioxide, have been established and constantly optimized for subsequent MS analysis. Concurrently, specific MS techniques were developed for more confident identification and phosphorylation site localization. In addition, more attention is paid to the LC‐MS instrumentation to avoid premature loss of phosphorylated peptides within the analytical system. Despite major advances in all of these fields, the analysis of phosphopeptides still remains far from being routine in proteomics. However, to reveal cellular regulation by phosphorylation events, not only qualitative information about the phosphorylation status of proteins but also, in particular, quantitative information about distinct changes in phosphorylation patterns upon specific stimulation is mandatory. Thus, yielded insights are of outstanding importance for the emerging field of systems biology. In this review, we will give an insight into the historical development of phosphoproteome analysis and discuss its recent progress particularly regarding phosphopeptide quantification and assessment of phosphorylation stoichiometry.
Understanding the improved sensitivity of spectral library searching over sequence database searching in proteomics data analysis
Authors: Zhang Xin , Li Yunzi , Shao Wenguang , Lam Henry 
Published: January 2011

AbstractSpectral library searching has been recently proposed as an alternative to sequence database searching for peptide identification from MS/MS. We performed a systematic comparison between spectral library searching and sequence database searching using a wide variety of data to better demonstrate, and understand, the superior sensitivity of the former observed in preliminary studies. By decoupling the effect of search space, we demonstrated that the success of spectral library searching is primarily attributable to the use of real library spectra for matching, without which the sensitivity advantage largely disappears. We further determined the extent to which the use of real peak intensities and non‐canonical fragments, both under‐utilized information in sequence database searching, contributes to the sensitivity advantage. Lastly, we showed that spectral library searching is disproportionately more successful in identifying low‐quality spectra, and complex spectra of higher‐ charged precursors, both important frontiers in peptide sequencing. Our results answered important outstanding questions about this promising yet unproven method using well‐controlled computational experiments and sound statistical approaches.
GPDE: A biological proteomic database for biomarker discovery and evaluation
Authors: Griss Johannes , Haudek‐Prinz Verena , Gerner Christopher 
Published: January 2011

AbstractClinical proteomics faces extremely complex and variable data. Here, we present an updated version of the Griss Proteomics Database Engine (GPDE): A free biological proteomic database specifically designed for clinical proteomics and biomarker discovery (http://gpde.sourceforge.net). It combines experiments based on investigated cell types thereby supporting customizable biological meta‐analyses. Through the new features described here, the GPDE now became a powerful yet easy‐to‐use tool to support the fast identification and reliable evaluation of biomarker candidates.
Development of oleic acid‐functionalized magnetite nanoparticles as hydrophobic probes for concentrating peptides with MALDI‐TOF‐MS analysis
Authors: Chen Hemei , Liu Shasha , Li Yan , Deng Chunhui , Zhang Xiangmin , Yang Pengyuan 
Published: January 2011

AbstractThe oleic acid‐functionalized magnetite nanoparticles (OA‐Fe3O4) with mean diameter of about 15 nm were synthesized through a low‐cost, one‐pot method and were designed as hydrophobic probes to realize the convenient, efficient and fast concentration of low‐concentration peptides followed by MALDI‐TOF‐MS analysis. The capability of OA‐Fe3O4 nanoparticles in concentration of low‐abundance peptides from simple and complex solutions were evaluated by comparing them with a sort of C8‐modified magnetic microspheres. Samples of standard peptide solution, protein digest solution and human serum were introduced in the evaluating process, and the OA‐Fe3O4 nanoparticles exhibited good surface affinity toward low‐concentration peptides
SearchGUI: An open‐source graphical user interface for simultaneous OMSSA and X!Tandem searches
Authors: Vaudel Marc , Barsnes Harald , Berven Frode S. , Sickmann Albert , Martens Lennart 
Published: January 2011

AbstractThe identification of proteins by mass spectrometry is a standard technique in the field of proteomics, relying on search engines to perform the identifications of the acquired spectra. Here, we present a user‐friendly, lightweight and open‐source graphical user interface called SearchGUI (http://searchgui.googlecode.com), for configuring and running the freely available OMSSA (open mass spectrometry search algorithm) and X!Tandem search engines simultaneously. Freely available under the permissible Apache2 license, SearchGUI is supported on Windows, Linux and OSX.