bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interspecific Mating and Cytological Studies of Closely Related Species of Ips DeGeer and Orthotomicus Ferrari (Coleoptera: Scolytidae)
Authors: Lanier Gerald N. 
Published: January 2010

AbstractInterspecific pairing of closely related species of Ips and Orthotomicus was undertaken to test their degree of breeding isolation. Pairings of the following species frequently resulted in sperm transfer but no eclosion: Ips mexicanus × I. concinnus (group I), confusus × montanus (group IX), plastographus (group III) × pini (group IV) and Orthotomicus latidens × O. sabinianae.Mating was generally unsuccessful when the more distantly related species, confusus × plastographus and confusus × pini, were paired.Individuals which produce all-female broods were discovered in a population of O. latidens. About 50% of the eggs deposited by these females hatched, whereas 92% of the eggs from “normal” females produced larvae.Cytological investigations revealed no constant differences between the karyotypes of I. mexicanus and concinnus (7AA+Xyp), O. latidens and sabinianae (9AA+Xyp), or between I. confusus and montanus (15AA+Xyp). I. pini (oregonis) and plastographus also have karyotypic formulae of 15AA+Xyp, but both are easily distinguished from confusus and montanus and an atypical chromosome in pini (oregonis) distinguishes it from plastographus. The mexicanus and concinnus karyotype and that of O. latidens and sabinianae can be directly derived from each other by fusion or fission. Their relationship to the karyotype of the European species O. proximus (6AA+Xy), is plausible but their karyotypes are composed of a remarkably different number of autosomal arms from those known for other species of Ips.
Associative Learning in Itoplectis conquisitor (Say) (Hymenoptera: Ichneumonidae)
Authors: Arthur A. P. 
Published: January 2010

AbstractFemales of I. conquisitor were conditioned to associate colour with the presence of hosts. Conditioning was important only during searching and did not affect the distribution of attacks once hosts were found. The ability of this species to associate colour with the presence of hosts could increase its efficiency as a parasite. Females of I. conquisitor showed an innate preference for blue over yellow.
CD155 Is Involved in Negative Selection and Is Required To Retain Terminally Maturing CD8 T Cells in Thymus
Authors: Qiu Quan , Ravens Inga , Seth Sebastian , Rathinasamy Anchana , Maier Michael K. , Davalos-Misslitz Ana , Forster Reinhold , Bernhardt Günter 
Published: January 2010

Abstract
During their final maturation in the medulla, semimature single-positive (SP) thymocytes downregulate activation markers and subsequently exit into the periphery. Although semimature CD4+ SP cells are sensitive to negative selection, the timing of when negative selection occurs in the CD8 lineage remains elusive. We show that the abundance of terminally matured CD8+ SP cells in adult thymus is modulated by the genetic background. Moreover, in BALB/c mice, the frequency of terminally matured CD8+ SP cells, but not that of CD4+ SP cells present in thymus, varies depending on age. In mice lacking expression of the adhesion receptor CD155, a selective deficiency of mature CD8+ SP thymocytes was observed, emerging first in adolescent animals at the age when these cells start to accumulate in wild-type thymus. Evidence is provided that the mature cells emigrate prematurely when CD155 is absent, cutting short their retention time in the medulla. Moreover, in nonmanipulated wild-type mice, semimature CD8+ SP thymocytes are subjected to negative selection, as reflected by the diverging TCR repertoires present on semimature and mature CD8+ T cells. In CD155-deficient animals, a shift was found in the TCR repertoire displayed by the pool of CD8+ SP cells, demonstrating that CD155 is involved in negative selection.
Commensal Microbiota and CD8+ T Cells Shape the Formation of Invariant NKT Cells
Authors: Wei Bo , Wingender Gerhard , Fujiwara Daisuke , Chen Diana YuHui , McPherson Michael , Brewer Sarah , Borneman James , Kronenberg Mitchell , Braun Jonathan 
Published: January 2010

Abstract
Commensal bacteria play an important role in formation of the immune system, but the mechanisms involved are incompletely understood. In this study, we analyze CD1d-restricted invariant NKT (iNKT) cells in germfree mice and in two colonies of C57BL/6 mice termed conventional flora and restricted flora (RF), stably bearing commensal microbial communities of diverse but distinct composition. In germfree mice, iNKT cells were moderately reduced, suggesting that commensal microbiota were partially required for the antigenic drive in maintaining systemic iNKT cells. Surprisingly, even greater depletion of iNKT cell population occurred in RF mice. This was in part attributable to reduced RF levels of intestinal microbial taxa (Sphingomonas spp.) known to express antigenic glycosphingolipid products. However, memory and activated CD8+ T cells were also expanded in RF mice, prompting us to test whether CD8+ T cell activity might be further depleting iNKT cells. Indeed, iNKT cell numbers were restored in RF mice bearing the CD8α−/− genotype or in adult wild-type RF mice acutely depleted with anti-CD8 Ab. Moreover, iNKT cells were restored in RF mice bearing the Prf1−/− phenotype, a key component of cytolytic function. These findings indicate that commensal microbiota, through positive (antigenic drive) and negative (cytolytic depletion by CD8+ T cells) mechanisms, profoundly shape the iNKT cell compartment. Because individuals greatly vary in the composition of their microbial communities, enteric microbiota may play an important epigenetic role in the striking differences in iNKT cell abundance in humans and therefore in their potential contribution to host immune status.
Influence of Treatment Conditions on the Chemical Oxidative Activity of H2SO4/H2O2 Mixtures for Modulating the Topography of Titanium
Authors: Variola Fabio , Lauria Alessandro , Nanci Antonio , Rosei Federico 
Published: January 2010

AbstractHost‐tissue integration of medical implants is governed by their surface properties. The capacity to rationally design the surface physico‐chemical cues of implantable materials is thus a fundamental prerequisite to confer enhanced biocompatibility. Our previous work demonstrated that different cellular processes are elicited by the nanotexture generated on titanium (cpTi) and Ti6Al4V alloy by chemical oxidation with a H2SO4/H2O2 mixture. Here, we illustrate that by varying the etching parameters such as temperature, concentration, and treatment time, we can create a variety of surface features on titanium which are expected to impact its biological response. The modified submicron and nanotextured surfaces were characterized by scanning electron (SEM) and atomic force (AFM) microscopies. Contact angle measurements revealed the higher hydrophilicity of the modified surfaces compared to untreated samples and Fourier transform infrared spectroscopy (FT‐IR) established that the etching generated a TiO2 layer with a thickness in the 40–60 nm range.
New method for age estimation of developmental defects of enamel formation in living populations
Authors: Gillett‐Netting Rhonda , Murphy Kimmarie 
Published: January 2010

AbstractHistologically based age of occurrence estimates for developmental defects of enamel (DDE) are raising questions about the continued utility of traditional macroscopic methods; however, the new techniques are not appropriate for use on living populations. This study, using methodology suitable for noninvasive use on living populations, compares assignment of defect timing using a histologically informed macroscopic method (HIMM) versus traditional methodology (TM). For this Southern African population, TM estimates later median age of DDE occurrence than HIMM (Z‐score: −13.565, P < 0.000) and modal age is 1 year earlier. HIMM allows for continued collection of DDE in living populations with the added benefit of more precise timing of enamel development. Accuracy for estimating general stressors during childhood is necessary for construction of diachronic analyses. Am. J. Hum. Biol., 2010. © 2010 Wiley‐Liss, Inc.
Great apes track hidden objects after changes in the objects' position and in subject's orientation
Authors: Albiach‐Serrano Anna , Call Josep , Barth Jochen 
Published: January 2010

AbstractEight chimpanzees (Pan troglodytes), five bonobos (Pan paniscus), five gorillas (Gorilla gorilla), and seven orangutans (Pongo pygmaeus) were presented with two invisible object displacement tasks. In full view of the subject, a food item was hidden under one of three opaque cups resting on a platform and, after an experimental manipulation, the subject was allowed to select one of the cups. In the rotation task, the platform was rotated 180° while the subject remained stationary. In the translocation task, the platform remained stationary while the subject walked to the opposite side from where she saw the reward being hidden. The final position of the food relative to the subject was equivalent in both tasks. Single displacement trials consisted of only one manipulation, either a rotation or a translocation, whereas double displacement trials consisted of both a rotation and a translocation. We also included no displacement trials in which no displacements took place. No displacement trials were easier than single displacements which, in turn, were easier than double displacements. Unlike earlier studies with children, there was no difference in performance between rotation and translocation displacements. Overall, apes performed above chance in all conditions, but chimpanzees outperformed the other species. This study reinforces the notion that the great apes use an allocentric spatial coding. Am. J. Primatol. 72:349–359, 2010. © 2010 Wiley‐Liss, Inc.
Einzelmoleküle als optische Nanosonden für weiche und komplexe Materie
Authors: Kulzer Florian , Xia Ted , Orrit Michel 
Published: January 2010

AbstractOptische Signale von Einzelmolekülen liefern Informationen über die Struktur und Dynamik ihrer nanoskaligen Umgebung, frei von zeitlichen und räumlichen Mittelungen. Die so erhaltenen Daten sind von Nutzen, wenn komplexe Strukturen oder Dynamiken auftreten, wie bei Polymeren oder porösen Oxiden, aber auch bei anderen Materialien, deren Heterogenität zunächst weniger offensichtlich ist. Der Aufsatz gibt einen Überblick über die wichtigsten aktuellen Anwendungen von Einzelmolekülen in Untersuchungen an kondensierter Materie auf Nanometerebene, mit Betonung auf weicher Materie und Materialwissenschaften. Beispiele umfassen die Orientierungsverteilung von Molekülen in Kristallen, Rotationsdiffusion in glasbildenden molekularen Flüssigkeiten, Studien an Polymeren mit Sonden und markierten Ketten, poröse und heterogene Oxidmaterialien, das Blinken einzelner Moleküle und Nanokristalle sowie das Potenzial oberfächenverstärkter Raman‐Streuung für die Analyse lokaler chemischer Eigenschaften. Die Beispiele zeigen, dass statische und dynamische Heterogenität und die Breiten der Verteilungen molekularer Parameter wesentlich größer sind, als bisher angenommen.
Iron oxide‐based magnetic nanostructures bearing cytotoxic organosilicon molecules for drug delivery and therapy
Authors: Zablotskaya Alla , Segal Izolda , Lukevics Edmunds 
Published: January 2010

AbstractThe results of our own investigation on synthesis, physico‐chemical and biological study of iron oxide based magnetic nanoparticles bearing cytotoxic organosilicon molecules of choline and colamine analogues, as potential agents for antitumor therapy, are summarized. These molecules contain hydrophilic head and long lipophilic tails, which are able to deepen inside the first surfactant shell (oleic acid), forming bilayer membrane like structures. Such compositions have a great privilege possessing magnetic properties, which in some cases could be essential moment in targeted drug delivery. The methodological approach has been developed and applied to the preparation of water soluble single or mixed coated biologically active nanoparticles of different types. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis of poly(vinylene‐arsine)s‐stabilized silver nanoparticles
Authors: Naka Kensuke , Nakahashi Akiko , Bravo Mia , Chujo Yoshiki 
Published: January 2010

AbstractStabilization of poly(vinylene‐arsine)s (1) towards silver nanoparticles was carried out to estimate the coordination and protecting ability of phenyl‐substituted poly(vinylene‐arsine) (1a) and methyl‐substituted poly(vinylene‐arsine) (1b). In the presence of 1 in 1:1 ratio with AgNO3, colloidal solutions were obtained. The methyl‐substituted poly(vinylene‐arsine) (1b) is a better stabilizer for silver nanoparticles in N,N‐dimethylformamide owing to its less bulky structure than the phenyl‐substituted poly(vinylene‐arsine) (1a). Copyright © 2010 John Wiley & Sons, Ltd.
Efficient fuel cell catalysts emerging from organometallic chemistry
Authors: Bönnemann Helmut , Khelashvili Guram 
Published: January 2010

AbstractDuring the last few decades organometallic methodologies have generated a number of highly effective electrocatalyst systems based on mono‐ and bimetallic nanosparticles having controlled size, composition and structure. In this microreview we summarize our results in fuel cell catalyst preparation applying triorganohydroborate chemistry, ‘reductive particle stabilization’ using organoaluminum compounds, and the controlled decomposition of organometallic complexes. The advantages of organometallic catalyst preparation pathways are exemplified with RuPt nanoparticles@C as promising anode catalysts to be used in direct methanol oxidation fuel cells (DMFC) or in polymer electrolyte fuel cells (PEMFC) running with CO‐contaminated H2 as the feed. Recent findings with highly efficient PtCo3@C fuel cell catalysts applied for the oxygen reduction reaction (ORR) and with the effect of Se‐doping on Ru@C ORR catalysts clearly demonstrate the benefits of organometallic catalyst synthesis. Copyright © 2010 John Wiley & Sons, Ltd.
Studies on the synthesis and thermal properties of alkoxysilane‐terminated organosilicone dendrimers
Authors: Saxena Kanak , Bisaria C. S. , Saxena A. K. 
Published: January 2010

AbstractSilicone core dendrimers bearing terminal dialkoxy and trialkoxy silane groups were prepared in a three‐step synthesis. Initially, the SiH terminated multifunctional silicone dendrimer, i.e. tetrakis(dimethylsiloxy)silane, was prepared by the reaction of tetraethoxysilane and dimethylethoxysilane. Tetrakis(dimethylsiloxy)silane on reaction with allylglycidylether in the presence of Speier's catalyst under pressure (100 psi) yielded epoxy‐terminated dendrimer in very high yield (95%). The epoxy‐terminated dendrimer was reacted with aminopropylalkoxysilanes to yield the next‐generation dendrimer bearing dialkoxy and trialkoxy silane groups. The dendrimers were characterized by the usual physico‐chemical techniques, i.e. elemental analysis, FT‐IR, 1H, 13C and 29Si NMR. Thermal studies (Thermogravimetric analysis and Thermomechanical analysis) of the alkoxy terminated dendrimers and its cured products were also carried out. Copyright © 2010 John Wiley & Sons, Ltd.
Application of confocal laser scanning microscope technique to visualize dynamic sorption behavior of perylene in cellulose acetate film
Authors: Hasegawa Takashi , Matsui Toshiro , Matsumoto Kiyoshi 
Published: January 2010

AbstractAdditives distributed in a polymer film were visualized by a confocal laser scanning microscope (CLSM) in this study. Cellulose acetate (CA) was used as the polymer film material. Perylene as a fluorescence reagent and glycerol triacetate (GTA) as a plasticizer for CA, respectively, were selected and mixed for visualizing the absorption of perylene into CA. Under optimized CLSM conditions of an objective lens (dry, 20×) and diode laser (408 nm, 290–330 μW), a fluorescent penetrant, perylene, in GTA solution was detected in CA casting film within around 9 μm depth of the film in 60 minutes after starting the sorption study. It was also found that the fluorescence intensity of perylene became lower with the film depth. This finding suggested that CLSM could visualize the sorption behavior of perylene as a dynamic diffusion process. Analytical conditions, such as a scanning range along the Z axis (±10 or ±30 μm from an air‐contact surface of the CA film) and a scan speed (1 or 30 fps) of CLSM, did not affect the fluorescence intensity of the sorbed perylene. It was concluded that a newly developed analytical methodology using CLSM was sufficient for visualizing the perylene penetrant across the cross‐sectional distribution of the CA film, being capable of monitoring the sorption behavior of compounds in polymer materials without any destruction of a given absorbed film. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis of well‐defined comblike hydroxy‐functionalized atactic polystyrene promoted by metallocene/tin/poly(phenyl glycidyl ether)‐co‐formaldehyde
Authors: Ma Lifu , Sheng Yaping , Huang Qigu , Deng Kunxue , Gao Kejing , Yang Wantai 
Published: January 2010

AbstractWell‐defined comblike atactic polystyrene functionalized with hydroxyl groups was synthesized via living/controlling radical polymerization promoted by metallocene complexes in the presence of poly(phenyl glycidyl ether)‐co‐formaldehyde as the initiator and Sn as a reducing agent. The effect of the polymerization conditions, such as the ratio of initiator to monomer, temperature, and polymerization time, and the structure of the metallocene complex on the polymerization process were investigated. The resulting polymers were characterized by gel permeation chromatography, multiangle laser light scattering, 1H‐NMR, and 13C‐NMR. The results show that the polymer had a narrow molecular weight distribution in the range 1.1–1.4 and the number‐average molecular weight of the polymer linearly depended on the monomer conversion within the polymerization timescale, which confirmed that living radical polymerization characteristics prevailed in the polymerization process. Both the number of arms and the number of hydroxyl groups in each polymer molecule were about four, which suggested that they arose from the epoxy functional groups of the initiator. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Optimization of the reaction conditions and characterization of L‐lactic acid direct polycondensation products catalyzed by a non‐metal‐based compound
Authors: Sedlarik Vladimir , Kucharczyk Pavel , Kasparkova Vera , Drbohlav Jan , Salakova Alexandra , Saha Petr 
Published: January 2010

AbstractIn this article, we deal with the investigation into a poly(lactic acid) (PLA) preparation process catalyzed by a non‐metal‐based compound. Low‐molecular‐weight PLA was synthesized by the direct melt polycondensation of L‐lactic acid catalyzed by methanesulfonic acid (MSA). This study was focused on the investigation into optimal MSA concentration determination and into the temperature (130, 145, 160, 175, and 190°C) and time (6, 12, 18, and 24 h) influence on the structure (Fourier transform infrared spectroscopy), molecular weight (viscometric measurements and gel permeation chromatography), and thermal properties (differential scanning calorimetry) of the samples. The results show an optimal MSA content of 0.5 wt %. The highest molecular weight of PLA prepared by this method was reached after 18 h of reaction at 175°C (weight‐average molar mass = 17.2 × 103 g/mol). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of quaternary ammonium PEGDA dendritic copolymer networks for water disinfection
Authors: Abid C. K. V. Zainul , Chattopadhyay Sruti , Mazumdar Nasreen , Singh Harpal 
Published: January 2010

AbstractQuaternary ammonium compounds are some of the most widely used antimicrobial agents for various medical applications due to their low toxicity and broad spectrum antimicrobial activity. Various generations of poly(ethyleneglycol)diacrylate (PEGDA) based dendrimers were synthesized by Michael addition reaction of PEGDA with ethylene diamine and diethyl amine. The percentage yield of different generation of dendrimers were 70%, 66%, 60%, and 85% for G1.0 (=), G1.5 (NH2), G2.0 (=), and G2.5 (=, NEt2), respectively. Synthesized dendrimers were also copolymerized with ethyleneglycol dimethacrylate by free radical bulk polymerization at room temperature using ammonium persulphate/N,N,N′,N′‐tetramethyl ethylenediamine as a redox initiator system to form dendritic copolymer networks. These networks were quaternized with hydrochloric acid by continuously refluxing at 40°C for 6 h. Dendrimers and quaternized dendritic copolymer networks were characterized by 1HNMR, FTIR, Differential scanning calorimetry, Thermogravimetric analysis, Scanning electron microscope, swelling, and leaching studies. Synthesized quaternary ammonium dendritic copolymer networks were found to be biostable and insoluble in water and capable of killing both Gram‐positive and Gram‐negative bacteria when contaminated water was treated with them. It was also observed that antimicrobial efficiency of dendritic copolymer networks increases with the increase in nitrogen atoms in the copolymer. The dendritic copolymer network with 16 quaternary ammonium groups (G2.5 (=, NEt2): EGDMA QHCl) were highly efficient to disinfect 10 mL bacterial solution of 2000 cfu/mL within 2 min even at a very low concentration of 0.005 g/mL. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and properties of novel aromatic polyamides with xanthene cardo groups
Authors: Sheng Shou‐Ri , Ma Chun‐Xin , Jiang Jian‐Wen , Huang Zhen‐Zhong , Song Cai‐Sheng 
Published: January 2010

AbstractTwo novel monomers, 9,9‐bis[4‐(4‐carboxyphenoxy)phenyl]xanthene (BCAPX) and 9,9‐bis[4‐(4‐aminophenoxy)phenyl]xanthene (BAPX) were prepared in two main steps starting from nucleophilic substitution of 9,9‐bis(4‐hydroxyphenyl)xanthene (BHPX) with p‐fluorobenzonitrile and p‐chloronitrobenzene, respectively. Using triphenyl phosphite and pyridine as condensing agents, two series of polyamides containing xanthene cardo groups with the inherent viscosities (0.82–1.32 dL/g) were prepared by polycondensation from BCAPX with various aromatic diamines or from BAPX with various aromatic dicarboxylic acids in an N‐methyl‐2‐pyrrolidone (NMP) solution containing dissolved calcium chloride, respectively. All new polyamides were amorphous and readily soluble in various polar solvents such as N,N‐dimethylformamide (DMF), NMP, N,N‐dimethylacetamide (DMAc) and pyridine. These polymers showed relatively high glass transition temperatures between 264 and 308°C, decomposition temperatures at 10% weight loss ranging from 502 to 540°C and 488 to 515°C in nitrogen and air, respectively, and char yields at 800°C in nitrogen higher than 56%. Transparent, flexible, and tough films of these polymers cast from DMAc solutions exhibited tensile strengths ranging from 86 to 109 MPa, elongations at break from 13 to 22%, and initial moduli from 2.15 to 2.63 GPa. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010