bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cover Picture: Spectroscopic and Photophysical Properties of a Highly Derivatized C60 Fullerol (Adv. Funct. Mater. 1/2006)
Authors: Vileno B. , Marcoux P. R. , Lekka M. , Sienkiewicz A. , Fehér T. , Forró L. 
Published: December 2005

AbstractThe photo‐oxidative stress in aqueous milieus can readily be generated in the presence of newly synthesized highly derivatized fullerenes (fullerols) reported in the Full Paper by Vileno and co‐workers on p. 120. Their basic structural and photophysical properties were characterized using a range of methods, including X‐ray photoelectron and IR spectroscopies, and electron spin resonance. Moreover, a significant drop of the local stiffness of a living cell was monitored using atomic force microscopy. This cell softening was attributed to the early effects of the photo‐oxidative stress.Hydroxylated C60 molecules, also called fullerols, are a class of water‐soluble fullerenes. Here we report the synthesis in acidic conditions of a highly derivatized fullerol (up to 36 carbons per C60 are oxidized). Spectroscopic investigations (X‐ray photoelectron spectroscopy and infrared absorption) highlight the coexistence of both acidic and basic forms for the hydroxyl addends of derivatized C60. pH titrimetry reveals that, at millimolar concentrations, only ten protons per fullerol molecule are labile. Such a low value, as compared to 36 hydroxyl groups, is explained by the formation of clusters. A UV‐vis absorption study performed over a large range of concentrations also points to the aggregation phenomenon. Moreover, this study shows that the clusters of fullerols appear at relatively low (micromolar) concentrations. An electron spin resonance (ESR) study, based on the attack of singlet oxygen (1Δg) on 2,2,6,6‐tetramethyl‐4‐piperidinol (TMP‐OH), has proved the potential of hydroxylated C60 for performing efficient generation of singlet oxygen in aqueous solution. ESR measurements, which allow detection and quantification of 1Δg, have also revealed the generation of reactive oxygen species (ROS). The yield of generation of 1Δg and ROS is strongly correlated to the concentration of fullerol, thus also pointing to the aggregation of fullerol molecules. Exposing glioblastoma cells to oxidative stress in the presence of hydroxylated C60 and visible light has also been performed. Atomic force microscopy is used to monitor the relevant diminishment of the Young's modulus values for cells exposed to the oxidative stress. These results point to a possible application field of fullerols for performing bio‐oxidations.
Dwarfs in ancient Egypt
Authors: Kozma Chahira 
Published: December 2005

AbstractAncient Egypt was one of the most advanced and productive civilizations in antiquity, spanning 3000 years before the “Christian” era. Ancient Egyptians built colossal temples and magnificent tombs to honor their gods and religious leaders. Their hieroglyphic language, system of organization, and recording of events give contemporary researchers insights into their daily activities. Based on the record left by their art, the ancient Egyptians documented the presence of dwarfs in almost every facet of life. Due to the hot dry climate and natural and artificial mummification, Egypt is a major source of information on achondroplasia in the old world. The remains of dwarfs are abundant and include complete and partial skeletons. Dwarfs were employed as personal attendants, animal tenders, jewelers, and entertainers. Several high‐ranking dwarfs especially from the Old Kingdom (2700–2190 BCE) achieved important status and had lavish burial places close to the pyramids. Their costly tombs in the royal cemeteries and the inscriptions on their statutes indicate their high‐ranking position in Egyptian society and their close relation to the king. Some of them were Seneb, Pereniankh, Khnumhotpe, and Djeder. There were at least two dwarf gods, Ptah and Bes. The god Ptah was associated with regeneration and rejuvenation. The god Bes was a protector of sexuality, childbirth, women, and children. He was a favored deity particularly during the Greco‐Roman period. His temple was recently excavated in the Baharia oasis in the middle of Egypt. The burial sites and artistic sources provide glimpses of the positions of dwarfs in daily life in ancient Egypt. Dwarfs were accepted in ancient Egypt; their recorded daily activities suggest assimilation into daily life, and their disorder was not shown as a physical handicap. Wisdom writings and moral teachings in ancient Egypt commanded respect for dwarfs and other individuals with disabilities. © 2005 Wiley‐Liss, Inc.
Synthesis and characterization of sequential interpenetrating polymer networks of novolac resin and poly(ethyl acrylate)
Authors: Goswami Sudipta , Chakrabarty Debabrata 
Published: December 2005

AbstractInterpenetrating polymer networks (IPN) of Novolac/poly(ethyl acrylate) have been prepared via in situ sequential technique of IPN formation. Both full and semi IPNs were characterized with respect to their mechanical properties that is, ultimate tensile strength (UTS), percentage elongation at break, modulus, and toughness. Physical properties of these were evaluated in terms of hardness, specific gravity, and crosslink density. Thermal behavior was studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The morphological features were observed by an optical microscope. There was a gradual decrease in modulus and UTS, with consequent increases in elongation at break and toughness for both types of IPNs with increasing proportions of PEA. An inward shift and lowering (with respect to pure phenolic resin) of the glass transition temperatures of the IPNs with increasing proportions of PEA were observed, thus, indicating a plasticizing influence of PEA on the rigid, brittle, and hard matrix of crosslinked phenolic resin. The TGA thermograms exhibit two‐step degradation patterns. An apparent increase in thermal stability at the initial stages, particularly, at lower temperature regions, was followed by a substantial decrease in thermal stability at the higher temperature region under study. As expected, a gradual decrease in specific gravity and hardness values was observed with increase in PEA incorporation in the IPNs. A steady decrease in crosslink densities with increase in PEA incorporation was quite evident. The surface morphology as revealed by optical microscope clearly indicates two‐phase structures in all the full and semi IPNs, irrespective of acrylic content. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
FTIR studies on the bond properties of the aspartyl phosphate moiety of the Ca2+–ATPase
Authors: Andersson Julia , Barth Andreas 
Published: December 2005

AbstractAs part of our work to determine the bond properties of the aspartyl phosphate moiety of the Ca2+–ATPase (SERCA1a) phosphoenzymes, we analyzed Morse potentials of the bridging PO bond as well as CO bond strengths for the model compound acetyl phosphate and the two phosphoenzyme intermediates Ca2E1P and E2P. Reaction‐induced infrared difference spectroscopy was used and a carbonyl band of E2P at 1708 cm–1 in the presence of mM Mg2+ was tentatively assigned to the carbonyl group of phosphorylated Asp351 because of its sensitivity to divalent cations. This band is found at 1716 cm–1 with mM Ca2+, for Ca2E1P at 1717 cm–1 with Mg2+, and at 1719 cm–1 with Ca2+ and at 1718 cm–1 for acetyl phosphate in the absence of divalent cations. The similar band positions indicate similar strengths of interaction of the carbonyl oxygen in acetyl phosphate and the two phosphoenzymes. Together with information on the PO bond strengths, this implies that the bridging oxygen exerts stronger interactions in the phosphoenzymes than in acetyl phosphate. © 2005 Wiley Periodicals, Inc. Biopolymers 82: 353–357, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Novel Five‐Membered Iminocyclitol Derivatives as Selective and Potent Glycosidase Inhibitors: New Structures for Antivirals and Osteoarthritis
Authors: Liang Pi‐Hui , Cheng Wei‐Chieh , Lee Yi‐Ling , Yu Han‐Pang , Wu Ying‐Ta , Lin Yi‐Ling , Wong Chi‐Huey 
Published: January 2006

AbstractA novel 5‐membered iminocyclitol derivative was found to be a potent and selective inhibitor of the glycoprotein‐processing α‐glucosidase with a Ki value of 53 nM. This compound was further derivatized to antiviral agents against Japanese encephalitis virus, dengue virus serotype 2 (DEN‐2), human SARS coronavirus, and human β‐hexosaminidase (Ki=2.6 nM), a new target for the development of osteoarthritis therapeutics.
Electrochemically Assisted Photocatalytic Oxidation of Nitrite over Cr‐Doped TiO2 under Visible Light
Authors: Shi J. Y. , Leng W. H. , Zhu W. C. , Zhang J. Q. , Cao C. N. 
Published: January 2006

AbstractTo investigate the photocatalytic oxidation (PCO) of nitrite ions under visible light, Cr‐doped TiO2 supported on a titanium plate was used as a photoelectrode operated under anodic bias potential. The results showed that applying bias potential (Eappl) played an important role in the PCO of NO2–. Without bias potential the PCO reaction could not be initiated due to the rapid recombination rate of the photogenerated carriers, but when the potential was larger than 1.2 V (vs. saturated calomel electrode, SCE) the removal efficiency of NO2– increased up to 90 % within 3 h for an initial concentration of 8 mg L–1. Zero‐order kinetics were observed at Eappl = 0.4 V (vs. SCE), while pseudo first order kinetics were found at Eappl ≥ 0.8 V (vs. SCE). The effects of the initial concentration of NO2–, initial solution pH, the gas atmosphere, and cathodic reaction on the PCO of NO2– were studied as well. Furthermore, the PCO mechanism of NO2– was investigated by using tert‐butyl alcohol or benzoic acid as a diagnostic probe. It showed that the PCO of NO2– under visible light most probably proceeded indirectly via OH radicals, not directly via the valence‐band holes.
Fluidization Characteristics of SiO2 Nanoparticles in an Acoustic Fluidized
Authors: Guo Q. , Li Y. , Wang M. , Shen W. , Yang C. 
Published: January 2006

AbstractUnder the action of an acoustic field, the fluidization behavior of 5–10 nm SiO2 nanoparticles, with and without surface modification, was investigated. In a packed bed, the sound wave energy has a significant influence on the compact ratio of the bed. Experimental results indicated that the bed of nanoparticle agglomerates can be fluidized smoothly with the assistance of an acoustic field, and the minimum fluidization velocity is initially reduced dramatically with increasing sound frequency and then rises with increasing sound frequency. Under the same experimental conditions, the minimum fluidization velocity of 5–10 nm SiO2 nanoparticles is greater than that of 5–10 nm SiO2 nanoparticles with surface modification. The collapse of the bed demonstrates that SiO2 nanoparticles, surface modified using organic compound, have longer minimum collapse times than SiO2 nanoparticles.
Bond Orders between Molecular Fragments
Authors: Bridgeman Adam J. , Empson Christopher J. 
Published: December 2005

AbstractAn extension of the Mayer bond order for the interaction between molecular fragments is presented. This approach allows the classical chemical concepts of bond order and valence to be utilised for fragments and the interactions between the fragments and symmetry‐adapted linear combinations to be analysed. For high‐symmetry systems, the approach allows the contribution from each irreducible representation to be assessed and provides a semiquantitative measure of the role of each bonding mode to interfragment interactions. The utility of this tool has been examined by a study of the bonding in symmetrical sandwich complexes. The validity of the frontier‐orbital approach and the contributions from each frontier‐orbital interaction can also be assessed within this model. As demonstrated by a study of a number of mixed‐sandwich complexes, the model proves to be especially useful for low‐symmetry systems in which separation of the σ, π and δ roles in bonding of the ligand is difficult to assess. The fragment bond order describes the interaction between preoptimized fragment orbitals and is independent of the charges that are placed on these fragments. Although the method allows the chemist to define fragments in any way they choose, most insight is gained by using the same frontier orbitals employed so successfully in perturbational molecular‐orbital approaches. The results are free from the influence of the electron‐counting method used to describe fragments, such as the rings and metals in sandwich complexes.
Platform Synthesis: A Useful Strategy for Rapid and Systematic Generation of Molecular Diversity
Authors: Itami Kenichiro , Yoshida Jun‐ichi 
Published: December 2005

AbstractEmergence of library‐based approaches have changed the way of developing new functional molecules in materials science and pharmaceutical science. Therefore, reliable methods for rapid and systematic generation of functional molecules are highly called for in this field. We herein describe our concept of “platform synthesis” as a useful strategy for generating molecular diversity. This simple yet powerful strategy realizes the synthesis of a number of interesting multifunctional molecules, such as multisubstituted olefins, in a programmable and diversity‐oriented format. As well as applications to the synthesis of pharmaceutically important molecules, such as tamoxifen and CDP840, applications to materials science, which have led to the discovery of interesting fluorescent materials and properties, are also described.
Characterization and Catalytic‐Hydrogenation Behavior of SiO2‐Embedded Nanoscopic Pd, Au, and Pd–Au Alloy Colloids
Authors: Pârvulescu Vasile I. , Pârvulescu Viorica , Endruschat Uwe , Filoti George , Wagner Friedrich E. , Kübel Christian , Richards Ryan 
Published: December 2005

AbstractColloids embedded in a silica sol–gel matrix were prepared by using fully alloyed Pd–Au colloids, and pure Pd and Au colloids stabilized with tetraalkylammonium bromide following a modified sol–gel procedure with tetrahydrofuran (THF) as the solvent. Tetraethoxysilicate (TEOS) was used as the precursor for the silica support. The molar composition of the sol was TEOS/THF/H2O/HCl=1:3.5:4:0.05 for the bimetallic Pd–Au and TEOS/THF/H2O/HCl=1:4.5:4:0.02 for Pd and Au monometallic systems. After refluxing, the colloid was added as a 4.5 wt % solution in THF for Pd–Au, 10.2 wt % solution in THF for Pd and 8.4 wt % solution in THF for Au at room temperature. The gelation was carried out with vigorous stirring (4 days) under an Ar atmosphere. Following these procedures, bimetallic Pd–Au–SiO2 catalysts with 0.6 and 1 wt % metal, and monometallic Pd– and Au–SiO2 catalysts with 1 wt % metal were prepared. These materials were further treated following four different routes: 1) by simple drying, 2) in which the dried catalysts were calcined in air at 723 K and then reduced at the same temperature, 3) in which they were directly reduced in hydrogen at 723 K, and 4) in which the surfactant was extracted using an ethanol–heptane azeotropic mixture. The catalysts were characterized by nitrogen adsorption–desorption isotherms at 77 K, H2 chemisorption measurements, solid‐state 1H, 13C, 29Si‐CP/MAS‐NMR spectroscopy, powder X‐ray diffraction (XRD), small angle X‐ray scattering (SAXS), X‐ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and 197Au Mössbauer spectroscopy. The physical characterization by a combination of these techniques has shown that the size and the structural characteristics of the Pd–Au colloid precursor are preserved when embedded in an SiO2 matrix. Catalytic tests were carried out in selective hydrogenation of 3‐hexyn‐1‐ol, cinnamaldehyde, and styrene. These data showed evidence that alloying Pd with Au in bimetallic colloids leads to enhanced activity and most importantly to improved selectivity. Also, the combination of the two metals resulted in catalysts that were very stable against poisoning, as was evidenced for the hydrogenation of styrene in the presence of thiophene.
Serial reversal learning of position discrimination in developing rats
Authors: Watson Deborah J. , Sullivan Jesse R. , Frank Julie G. , Stanton Mark E. 
Published: December 2005

AbstractThe current study established a procedure to evaluate the capability of rats on postnatal days (PND) 21, 26, and 30 to perform a spatial serial reversal task using a T‐maze. Training consisted of an acquisition session followed by a series of six reversal sessions. To examine the role of proactive interference in the serial reversal effect, the point of reversal was manipulated so that it occurred at the start of each session (between‐sessions) or the midpoint of each session (within‐sessions). Performance was initially impaired during the first reversal but improved dramatically across the series. Reversal between‐sessions enhanced this serial reversal effect in comparison to reversal within‐sessions. Experiment 1 showed that rats of all ages learned the between‐sessions serial reversal task at a comparable rate. However, on the within‐sessions task, PND21 rats were impaired relative to the PND26 and 30 rats, which did not differ. Experiment 2 revealed that the addition of a tactile cue that is correlated with each phase of reversal eliminated age and task differences in serial reversal performance. These findings suggest that higher‐order cognitive processes underlying serial reversal are present during the weanling period, but there is some improvement with age under conditions involving high memory interference and/or difficulty in detecting the transition between reversal phases. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 48: 79–94, 2006.
Examining the role of endogenous opioids in learned odor–stroke associations in infant rats
Authors: Roth Tania L. , Sullivan Regina M. 
Published: December 2005

AbstractMaternal touch profoundly regulates infant neural and behavioral development, and supports learned odor associations necessary for infant attachment. Endogenous opioids are well characterized to mediate the calming and analgesic properties of maternal touch; yet their role in learned odor–touch associations is unknown. We administered naltrexone, an opioid receptor antagonist, before or immediately following classical conditioning with peppermint odor and tactile stimulation (stroking) in rat neonates. Results indicate odor–stroke conditioning produces odor preferences facilitated by endogenous opioids during acquisition and memory consolidation. These results provide additional evidence for the modulatory role of opioids in neonate learning and memory. Disturbances to this system may alter the impact of touch on infant development, particularly in the realm of learning necessary for attachment. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 48: 71–78, 2006.
Trace conditioning in 1‐day‐old rats
Authors: Bordner Kelly A. , Spear Norman E. 
Published: December 2005

AbstractA recent test of 3‐hr‐old rats indicated surprisingly effective trace conditioning with a 60‐s trace interval. The present study tested similar trace conditioning in pups 24‐hr‐old, in the absence of circumstances that immediately follow birth and might promote cognition. In Experiment 1 pairing an olfactory CS with a gustatory US yielded conditioning despite a 120‐s trace. Experiment 2 determined that ambient CS odor remaining in the vicinity of the conditioning surface was not sufficient to result in the olfactory–gustatory association. Experiment 3 applied conditioning procedures more like those previously used for the 3‐hr‐old infant and more stringent than those applied in Experiment 1. With these procedures the 24‐hr‐old pups nevertheless acquired the CS–US contingency with a 60‐s trace. Perhaps perinatal tolerance for long trace intervals is linked to their substantial experience in dealing with odors and tastes prenatally and postnatally. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 48: 58–70, 2006.
Embryonic origin of mate choice in a lizard with temperature‐dependent sex determination
Authors: Putz Oliver , Crews David 
Published: December 2005

AbstractIndividual differences in the adult sexual behavior of vertebrates are rooted in the fetal environment. In the leopard gecko (Eublepharis macularius), a species with temperature‐dependent sex determination (TSD), hatchling sex ratios differ between incubation temperatures, as does sexuality in same‐sex animals. This variation can primarily be ascribed to the temperature having direct organizing actions on the brain. Here we demonstrate that embryonic temperature can affect adult mate choice in the leopard gecko. Given the simultaneous choice between two females from different incubation temperatures (30.0 and 34.0° C), males from one incubation temperature (30.0° C) preferred the female from 34.0° C, while males from another incubation temperature (32.5° C) preferred the female from 30.0° C. We suggest that this difference in mate choice is due to an environmental influence on brain development leading to differential perception of opposite‐sex individuals. This previously unrecognized modulator of adult mate choice lends further support to the view that mate choice is best understood in the context of an individual's entire life‐history. Thus, sexual selection results from a combination of the female's as well as the male's life history. Female attractiveness and male choice therefore are complementary. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 48: 29–38, 2006.
Age‐related changes in memory reactivation by 1‐ and 2‐year‐old human infants
Authors: Morgan Kirstie , Hayne Harlene 
Published: December 2005

AbstractIn three experiments, we examined the effect of a single reactivation treatment on retention by 1‐ and 2‐year‐old human infants who were tested in the visual recognition memory (VRM) paradigm. In all experiments, infants were familiarized with a visual stimulus and were tested after a delay. In the absence of a reactivation treatment, infants of both ages exhibited forgetting but exposure to a reactivation treatment alleviated forgetting after the same delay. When the duration of the original familiarization period was only 10 s, the minimum duration of an effective reminder treatment was 1 s for 2‐year‐olds, but was 5 s for 1‐year‐olds. When the duration of the original familiarization period was increased to 30 s, however, a 1‐s reminder also alleviated forgetting by 1‐year‐olds. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 48: 48–57, 2006.