bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of organophosphorous pesticides in the ppq range using a simple solid‐phase extraction method combined with dispersive liquid–liquid microextraction
Authors: Alves Andreia Cristina Henriques , Gonçalves Maria Margarida Pontes Boavida , Bernardo Maria Manuel Serrano , Mendes Benilde Simões 
Published: July 2011

AbstractSolid‐phase extraction combined with dispersive liquid–liquid microextraction (SPE‐DLLME) was applied for the extraction of six organophosphorous pesticides (OPPs) in water samples. The analytes considered in this study were determined by gas chromatography with mass spectrometry and included prophos, diazinon, chlorpyrifos methyl, methyl parathion, fenchlorphos and chlorpyrifos. Several extraction conditions (extraction solvent and elution/dispersion solvents nature, extraction solvent volume, elution solvent volume, water volume and sample volume) were tested for SPE‐DLLME with these analytes and the best results were obtained using carbon tetrachloride as the extraction solvent and acetone as the elution/dispersion solvent. Calibration curves for the determination of OPPs in water samples were constructed in the concentration range of 10–100 ng/L. Limits of detection (LODs) ranged from 38 to 230 pg/L values that are below the maximum admissible level for drinking water (100 ng/L). Relative standard deviations (RSD) were between 8.6 and 10.4% for a fortification level of 100 ng/L. At the same fortification level, the relative recoveries (R.R.) of tap, well and irrigation water samples were in the range of 30.2–97.1%.
Contributors to traumatic exposure and posttraumatic stress disorder in juvenile justice youths
Authors: Wasserman Gail A. , McReynolds Larkin S. 
Published: July 2011

AbstractThis study considers demographic, offense, and disorder contributors to exposure and posttraumatic stress disorder (PTSD) in a large (N = 9,611) dataset of standardized psychiatric assessments resulting from nationwide collaborations with justice agencies. Youths' antisocial history may elevate risk for traumatic exposure and PTSD; additionally, traumatic victimization increases risk for externalizing behavior. Rates of all types of traumatic exposure and PTSD were clearly elevated and expectably related to disorder and antisocial behavior. Males were significantly more likely than females to report assaultive violence, whereas females were significantly more likely than males to report forced sexual activity. Gender interactions with disorder and antisocial behavior were contributory only in predicting forced sexual activity: females' exposure was not conditional on features characterizing males' exposure. Findings highlight the high levels of trauma exposure at all levels of juvenile justice processing, and the particular vulnerability of males with internalizing psychopathology. Consistent with increased recent interest in the diagnosis of developmental trauma disorder, and given the likely interconnectedness between traumatic exposure and externalizing symptoms, treatment approaches for justice youths should address their co‐occurrence.
Energy‐Independent Intracellular Gene Delivery Mediated by Polymeric Biomimetics of Cell‐Penetrating Peptides
Authors: Chae Su Young , Kim Hyun June , Lee Min Sang , Jang Yeon Lim , Lee Yuhan , Lee Soo Hyeon , Lee Kyuri , Kim Sun Hwa , Kim Hong Tae , Chi Sang‐Cheol , Park Tae Gwan , Jeong Ji Hoon 
Published: July 2011

AbstractEfficient gene transfer into mammalian cells mediated by small molecular amphiphile‐polymer conjugates, bile acid‐polyethylenimine (BA‐PEI), is demonstrated, opening an efficient transport route for genetic materials across the cell membrane. This process occurs without the aid of endocytosis or other energy‐consuming processes, thus mimicking macromolecular transduction by cell‐penetrating peptides. The exposure of a hydrophilic face of the amphiphilic BA moiety on the surface of BA‐PEI/DNA complex that mediates direct contact of the BA molecules to the cell surface seems to play an important role in the endocytosis‐ and energy‐independent internalization process. The new modality of the polymeric biomimetics can be applied to enhanced delivery of macromolecular therapeutics.magnified image
Surface Property Modification of Epoxy Coatings by Polydimethylsiloxanes
Authors: Sangermano Marco , Sordo Federica , Messori Masismo 
Published: July 2011

AbstractSurface properties of epoxy coatings are modified by PDMS additives in cationic UV curing of a cycloaliphatic epoxy resin. The cured films show a very high hydrophobicity that does not depend on PDMS concentration, indicating that a threshold is reached even at 0.3 wt% additive. A slight increase of the water contact angle as a function of PDMS molecular weight is observed. The additive selectively modified the air‐side of the film, while the glass‐side retains the surface properties of the pure resin. This segregation phenomenon permits to obtain highly hydrophobic films with still good adhesion properties on polar substrates, which is an important advantage over common surface‐modified resins.magnified image
A note on groups of colour preserving automorphisms
Authors: Baumann Ulrike , Holthaus Ute 
Published: July 2011

AbstractA perfect edge colouring of a graph is defined by the property that all colour matchings are perfect matchings. Every edge‐coloured graph determines a group of graph automorphisms which preserve the colours of the edges. If the graph is connected, then this group of colour preserving automorphisms is a semiregular permutation group. The question which semiregular permutation groups with exactly one orbit or with an even number k of orbits arise as groups of colour preserving automorphisms of graphs with perfect edge colourings has been answered in 1,2. The present paper deals with the problem for semiregular permutation groups with an odd number of orbits.
Generalized Hankel operators on the Fock space II
Authors: Schneider Georg , Schneider Kristan 
Published: July 2011

AbstractIn this paper we study boundedness of generalized Hankel operators of the form \documentclass{article}\usepackage{amssymb,mathrsfs}\begin{document}\pagestyle{empty}${\rm H}_{{\overline{z}}^k}^l: {\mathscr F}^2\big (|z|^2\big )\rightarrow L^2\big (|z|^2\big )$\end{document} and thereby extend our results from 10. Here, \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\rm H_{{\overline{z}}^k}^l(f):=(\rm Id-\rm P_l)\big (\overline{z}^k f\big )$\end{document} and Pl is the projection onto \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$A^2_l\big (\mathbb C,| z|^2\big ):=\rm cl\big (\rm span\lbrace \overline{z} ^mz^n\,|\,m,n\in \mathbb N,\,m\le l\rbrace \big )$\end{document}. Additionally, we extend our results to general conjugate‐holomorphic L2 symbols. The arguments applied show a tight connection between operator theory and combinatorics.
Three‐dimensional Arrangement of Short DNA Oligonucleotides at Surfaces via the Synthesis of DNA‐branched Polyacrylamide Brushes by SI‐ATRP
Authors: Henry Olivier Y. F. , Mehdi Ahmed D. , Kirwan Sinead , Sanchez Josep Luis Acero , O'Sullivan Ciara K. 
Published: July 2011

AbstractShort DNA oligonucleotide branches are incorporated into acrylamide brushes via surface initiated atom transfer radical polymerization in an attempt to increase DNA surface density by building three‐dimensional molecular architectures. ATR‐FTIR as well as hybridization studies followed by SPR confirm the incorporation of the DNA sequences into the polymer backbone. MALDI‐TOF analysis further suggests that six acrylamide monomer units are typically separating DNA branches present on a single brushes approximately 26 units long. This new approach offers a promising alternative to SAM‐based nucleic acid and aptamer sensors and could enable the realization of more complex soft materials of controlled architecture capable of both recognition and signaling by including additional optically or electrochemically active moieties.magnified image
Macroporous Polymers with Hierarchical Pore Structure from Emulsion Templates Stabilised by Both Particles and Surfactants
Authors: Wong Ling L. Ching , Ikem Vivian O. , Menner Angelika , Bismarck Alexander 
Published: July 2011

AbstractInspired by natural porous materials, such as wood, bamboo and spongy bone consisting of individual structural units that are hierarchically arranged to optimise mechanical properties such as strength and toughness, synthetic macroporous polymers with enhanced physical properties were created by emulsion templating. Hierarchical poly(merised) high internal phase emulsions (HIPE) were created from HIPEs stabilised simultaneously by particles and a surfactant. In these HIPEs, surfactant stabilised and particle stabilised water droplets coexist, which upon polymerisation of the minority oil phase gives rise to macroporous polymers with a hierarchical pore structure. An improvement of the mechanical properties of our hierarchically structured macroporous polymers at equal porosity was observed, due to a more efficient packing of pores in a configuration that improves mechanical strength despite the presence of interconnecting pore throats. Moreover, the permeability of the hierarchically structured polyHIPEs are exceeding those measured for conventional polyHIPEs made from surfactant only stabilised HIPEs.magnified image
Compartmentalization Effects on Bimolecular Termination in Atom Transfer Radical Polymerization in Nanoreactors
Authors: Zetterlund P. B. 
Published: July 2011

AbstractThe factors that determine the magnitude of the segregation effect in atom transfer radical polymerization (ATRP) in a dispersed system (miniemulsion, emulsion, etc.) have been elucidated by means of simulations based on two‐dimensional Smith–Ewart equations. The segregation effect is not a function of merely the average number of propagating radicals per particle, but also depends on the values of the deactivation and termination rate coefficients. This occurs as a result of these rate coefficients exerting an influence on the distribution of propagating radicals between the particles, which in turn affects the termination rate. The results provide further information as to how one can potentially exploit compartmentalization to improve livingness (end‐functionality) in ATRP in dispersed systems. magnified image
Critical Micelle Concentration of Micelles with Different Geometries in Diblock Copolymer/Homopolymer Blends
Authors: Zhou Jiajia , Shi An‐Chang 
Published: July 2011

AbstractIt is well‐known that A‐B diblock copolymers in selective solvents or A‐homopolymers can form micelles of different shapes. The critical micelle concentration (CMC) of three basic micelle shapes (lamellar, cylindrical, and spherical) are calculated using the self‐consistent field theory formulated in the grand canonical ensemble. For a given set of molecular parameters, the stable micelle morphology is determined by a comparison of the CMC. The results confirm that micelles undergo a sequence of shape transitions, lamellar → cylindrical → spherical, when the A‐block of the diblock copolymer becomes longer. The results also reveal details about the micelle structure, such as the core radius and corona thickness. This information can be used to understand the effect of homopolymer molecular weight and monomer–monomer interaction on the micelle morphologies.magnified image
BIMM: A Bias Induced Matrix Model for Incomplete Reciprocal Pairwise Comparison Matrix
Authors: Ergu Daji , Kou Gang , Peng Yi , Shi Yong , Shi Yu 
Published: July 2011

ABSTRACTThe reciprocal pairwise comparison matrix is a well‐established technique and widely used in multiple criteria decision making methods. However, some entries in a pairwise comparison matrix may not be available in many real‐world decision problems. The goal of this paper is to propose a new method for estimating missing elements of an incomplete pairwise comparison matrix. A bias induced matrix model (BIMM), which combines the matrix multiplication and the properties of the original reciprocal pairwise comparison matrix, is used to calculate the missing entries in an incomplete pairwise comparison matrix. The proposed BIMM minimizes all bias values of the bias induced matrix to keep the global consistency. The missing value(s) can be estimated by solving the system of equations from the bias induced matrix. The theorems of the BIMM and the related corollaries are developed, and three numerical examples are introduced to illustrate the proposed model. Copyright © 2011 John Wiley & Sons, Ltd.
Lessons from probiotic–host interaction studies in murine models of experimental colitis
Authors: Claes Ingmar J. J. , De Keersmaecker Sigrid C. J. , Vanderleyden Jos , Lebeer Sarah 
Published: July 2011

AbstractIn inflammatory bowel diseases (IBD), it is known that besides genetic and environmental factors (e.g. diet, drugs, stress), the microbiota play an important role in the pathogenesis. Patients with IBD have an altered microbiota (dysbiosis) and therefore, probiotics, defined as ‘live micro‐organisms that when administered in adequate amounts can confer a health benefit on the host’, have been suggested as nutritional supplements to restore these imbalances. The best response on probiotics among the different types of IBD appears to be in the case of ulcerative colitis. Although probiotics show promise in IBD in both clinical and animal studies, further mechanistic studies are necessary to optimize the use of probiotics as supporting therapy in IBD. Murine models of experimental colitis have been used for decades to study this pathology, and these models have been proven useful to search for new therapeutic approaches. The purpose of this review is to summarize probiotic–host interaction studies in murine models of experimental colitis and to evaluate how these models can further help in understanding these complex interactions. Unraveling the molecular mechanisms behind the beneficial effects will assist in better and possibly more efficient probiotic formulations.
Vitamin C modulates the interaction between adipocytes and macrophages
Authors: Garcia‐Diaz Diego F. , Campion Javier , Quintero Pablo , Milagro Fermin I. , Moreno‐Aliaga Maria J. , Martinez José. A. 
Published: July 2011

AbstractScope: Increased adiposity is related with monocyte infiltration into the adipose tissue that accentuates inflammation. Antioxidant treatments emerge as approaches to counteract this phenomenon.Methods and results: Cocultures of differentiated 3T3‐L1 adipocytes and RAW264.7 macrophages were incubated for 24–72 h with/without 100 nM insulin and/or 200 μM vitamin C (VC). Nitric oxide (NO) secretion (24 h) was measured. Also, expression (24 h) and secretion (72 h) of MCP‐1, leptin and apelin were analyzed. NO secretion was significantly inhibited by insulin and VC only in cocultures. MCP‐1 expression/secretion was enhanced in cocultures. Insulin incubation reduced MCP‐1 expression in both cultures and VC only in controls. Both treatments inhibited MCP‐1 secretion in cocultures. Apelin gene expression was induced in cocultures. Insulin induced apelin mRNA expression, but VC inhibited its expression in cocultures under insulin treatment. Apelin secretion was notably induced by insulin and inhibited by VC in cocultures. Leptin expression was decreased in coculture, while presented no effects by VC.Conclusion: VC importantly modulates the established pro‐inflammatory state in the interaction between adipocytes and macrophages.
A Study of Particle Nucleation in Dispersion Copolymerization of Methyl Methacrylate
Authors: Cockburn Robert A. , McKenna Timothy F. L. , Hutchinson Robin A. 
Published: July 2011

AbstractThe dispersion polymerization of methyl methacrylate (MMA) and its copolymerization with the bio‐renewable monomer γ‐methyl‐α‐methylene‐γ‐butyrolactone (MeMBL) is studied in a methanol/water mixture. The addition of MeMBL to an MMA dispersion decreases both rate and particle size (PS), while rate decreases and PS increases when the fraction of methanol in the continuous phase is increased. The differing effects of comonomer and continuous phase composition can be attributed to monomer partitioning and critical chain length (jcrit) of the radicals formed in solution. A cobalt(II) catalytic chain transfer agent (CCTA) was used to determine a value of 20–30 monomer units for jcrit in MMA dispersion polymerization. A distinct population of small particles, about one‐tenth as large as the 1–2 µm mature particles, was observed throughout the entire course of the dispersion polymerization; it is these particles, most likely aggregates of nuclei continuously generated in solution, that are swept up by the mature particles during growth.magnified image
Developmental Stress and Survival among the Mid Upper Paleolithic Sunghir Children: Dental Enamel Hypoplasias of Sunghir 2 and 3
Authors: Guatelli‐Steinberg D. , Buzhilova A. P. , Trinkaus E. 
Published: July 2011

ABSTRACTThe Sunghir 2 and 3 late juvenile to early adolescent immature skeletons, from the Mid Upper Paleolithic (Eastern Gravettian) of northern Russia, exhibit several episodes of dental enamel hypoplasias. Those of the older male Sunghir 2 relate principally to a stress episode in the third year post‐natal, although subsequent minor stress episodes may be indicated. They are not accompanied by other marked developmental abnormalities. The younger female Sunghir 3 exhibits at least three episodes of pronounced post‐natal stress through the third to fifth years post‐natal, followed by femoral and tibial growth arrest lines that formed shortly before her death at 9–11 years. These first decade post‐natal stress episodes of Sunghir 3 may be related to the same developmental condition that produced her abnormally bowed femora pre‐natally and/or to continued frailty related to that condition. Surviving these stress episodes for different lengths of time, both Sunghir 2 and 3 were awarded the most elaborate Paleolithic burial known. Copyright © 2011 John Wiley & Sons, Ltd.
MLL gene rearrangements in infant leukemia vary with age at diagnosis and selected demographic factors: A Children's Oncology Group (COG) study
Authors: Sam Thien N. , Kersey John H. , Linabery Amy M. , Johnson Kimberly J. , Heerema Nyla A. , Hilden Joanne M. , Davies Stella M. , Reaman Gregory H. , Ross Julie A. 
Published: July 2011

AbstractBackgroundInfant leukemias have a high frequency of mixed lineage leukemia (MLL) gene rearrangements.ProcedureUsing data from a large etiologic study, we evaluated the distribution of selected demographic factors among 374 infant leukemia cases by leukemic subtype, MLL status and diagnosis age.ResultsOverall, 228 cases were MLL+. Compared to white infants, black infants were significantly less likely to have MLL+ leukemia. Further, there was a statistically significantly higher age at diagnosis for infants with t(9;11) translocations compared to all other translocation partners in both acute lymphoblastic leukemia and acute myeloid leukemia cases.ConclusionThese patterns may provide important etiological insight into the biology of infant leukemia. Pediatr Blood Cancer 2012; 58: 836–839. © 2011 Wiley Periodicals, Inc.
Differential proteomic analysis of highly purified placental cytotrophoblasts in pre‐eclampsia demonstrates a state of increased oxidative stress and reduced cytotrophoblast antioxidant defense
Authors: Johnstone Edward D. , Sawicki Grzgorz , Guilbert Larry , Winkler‐Lowen Bonnie , Cadete Virgilio J. J. , Morrish Donald W. 
Published: July 2011

AbstractProteomics were performed using highly (99.99%) purified cytotrophoblasts from six normal and six pre‐eclamptic placentas. Eleven proteins were found which decreased in pre‐eclampsia (actin, glutathione S‐transferase, peroxiredoxin 6, aldose reductase, heat shock protein 60 (Hsp60), two molecular forms of heat shock protein 70 (Hsp70) β‐tubulin, subunit proteasome, ezrin, protein disulfide isomerase, and phosphoglycerate mutase 1). Only one protein, α‐2‐HS‐glycoprotein (fetuin), was found to increase its expression. Western blots of actin, Hsp70, ezrin, and glutatione S‐transferase confirmed decrease in protein expression. Many of the proteins that decreased are consistent with a state of oxidative stress in the pre‐eclamptic placenta and a decreased cytotrophoblast defense against and response to oxidative stress.
Polymer brushes on multiwalled carbon nanotubes by activators regenerated by electron transfer for atom transfer radical polymerization
Authors: Aitchison Tony J , Ginic‐Markovic Milena , Saunders Martin , Fredericks Peter , Valiyaveettil Suresh , Matisons Janis G. , Simon George P. 
Published: July 2011

AbstractThe synthesis and characterization of multiwalled carbon nanotube (MWCNT) polymer brushes produced by activators regenerated by electron transfer (ARGET) in atom‐transfer radical polymerization (ATRP) was discussed. The polymer brushes were synthesized by esterification of the MWCNT carboxylic acid groups with hydroxyethyl‐2‐bromoisobutyrate and subsequently used in ARGET ATRP. This created a well defined living polymer brush carbon nanotube of comparatively low polydispersity and a polymer layer 10 nm thick. As, ARGET ATRP uses only minute concentrations of copper (II) catalyst, and is less sensitive to air compared to other living polymerization techniques, this process is a more industry‐compatible route for the commercialization of such materials. The structural and chemical properties were explored by a range of techniques including high resolution transmission electron microscopy, gel permeation chromatography, elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. In addition, the polymer brush nanotubes were explored for their potential use in films and as fillers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Cellulose‐based graft copolymers with controlled architecture prepared in a homogeneous phase
Authors: Raus Vladimír , Štěpánek Miroslav , Uchman Mariusz , Šlouf Miroslav , Látalová Petra , Čadová Eva , Netopilík Miloš , Kříž Jaroslav , Dybal Jiří , Vlček Petr 
Published: July 2011

AbstractCellulose‐based macroinitiators with predetermined number of initiation sites were synthesized by acylation of microcrystalline cellulose AVICEL PH‐101 with 2‐bromoisobutyryl bromide under homogeneous reaction conditions in the N,N‐dimethylacetamide/LiCl solvent system. The influence of different methods of cellulose activation on acylation efficiency and reproducibility was investigated. Best results were obtained using thermal activation under reduced pressure or the newly introduced protocol based on solvent exchange to 1,4‐dioxane. Prepared macroinitiators were used for grafting with styrene and methyl methacrylate (MMA) using optimized atom transfer radical polymerization reaction conditions to achieve well‐controlled polymerizations with high initiation efficiency. For MMA grafting, the initiation efficiency was shown to be dependent on certain reaction conditions, such as type of solvent, monomer concentration, or the presence of a sacrificial initiator. In addition, single‐electron transfer living radical polymerization with Cu(0) as the catalyst was used for the first time to prepare cellulose‐graft‐polystyrene and cellulose‐graft‐poly(MMA) copolymers in a homogeneous phase. In summary, homogeneous reaction conditions, stoichiometric control in the preparation of macroinitiators, and controlled grafting jointly allowed for an extensive control of copolymers architecture, that is, density of grafting, composition, and molecular parameters of grafts. Moreover, some of the prepared copolymers were characterized by static and dynamic light scattering and microscopic techniques (transmission electron microscopy and atomic force microscopy). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011