bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organic Functional Molecules towards Information Processing and High‐Density Information Storage
Authors: Jiang Guiyuan , Song Yanlin , Guo Xuefeng , Zhang Deqing , Zhu Daoben 
Published: July 2008

AbstractIn this Progress Report, we discuss our recent achievements in design and synthesis of new functional molecules towards information processing at the molecular level and high‐density information storage. These include: 1) new molecular switches, logic gates, and combinational logic circuits based on molecules and ensembles with photochromic spiropyran units that undergo reversible structural transformation among multistates, in response to external inputs such as light, protons, and metal ions; 2) high‐density information storage, mainly focusing on nanometer‐scale electrical recording based on the conductance transition of organic molecules, and multimode data storage on multiresponsive molecules. Relevant progress and an outlook in this area are also discussed.magnified image
Supramolecular Chiroptical Switches Based on Achiral Molecules
Authors: Qiu Yunfeng , Chen Penglei , Guo Peizhi , Li Yuangang , Liu Minghua 
Published: July 2008

AbstractChirality plays an important role in biological and material sciences. By introducing chiral elements into functional materials, new properties are created and an increase in information density can be achieved. Chiral properties of functional materials do not only rely on molecular structure, but also on supramolecular interaction between the building blocks. In contrast to the generally accepted opinion that chiral systems should include chiral molecules, this Research News introduces the role of achiral molecules in realizing chiral properties in films and gel‐like materials. Even a system that is entirely composed of achiral molecules can exhibit interesting chiroptical properties in supramolecular ultrathin films. This article demonstrates how achiral molecules can be assembled into supramolecular chiral films and organogels. It further shows how the incorporated achiral molecules can be used to switch the chiral properties of these supramolecular films and organogels.
Solid‐Phase Synthesis of [5.5]‐Spiroketals
Authors: Sommer Stefan , Kühn Marc , Waldmann Herbert 
Published: July 2008

AbstractAn efficient and reliable multi‐step synthesis of 251 natural product‐like [5.5]‐spiroketals on solid supports has been developed. As central key step, a double intramolecular hetero‐Michael (DIHMA) reaction to alkynones was applied. The sequence allows for introduction of numerous substituents on the scaffold and for variation of stereochemistry. [5.5]‐Spiroketals bearing an additional ketone were obtained in high overall yields. Further diversification was achieved by reduction of the ketone and reductive amination using polymer‐supported borohydride, Grignard reaction and conversion to oxime derivatives in the solution phase.
Studies toward the Synthesis of (−)‐Zampanolide: Preparation of the Macrocyclic Core
Authors: Troast Dawn M. , Yuan Jiayi , Porco John A. 
Published: July 2008

AbstractStudies towards the synthesis of the macrocyclic core of (−)‐zampanolide are reported. The synthetic approach features a one‐pot reduction/vinylogous aldol reaction for construction of the C‐15–C‐20 fragment, an intramolecular silyl‐modified Sakurai (ISMS) reaction for construction of the 2,6‐cis‐disubstitutedexo‐methylene pyran subunit, and use of ansp2‐sp3Stille reaction for macrocyclization.
Enzyme‐Catalyzed Synthesis of a Hybrid N‐Linked Oligosaccharide using N‐Acetylglucosaminyltransferase I
Authors: Chen Rui , Pawlicki Mark A. , Hamilton Brian S. , Tolbert Thomas J. 
Published: July 2008

AbstractThe soluble catalytic domain of human N‐acetylglucosaminyltransferase I was purified from Escherichia coli and utilized in the enzyme‐catalyzed conversion of high mannose N‐linked oligosaccharide 1 into the rare hybrid oligosaccharide 2. Analysis of the reaction showed that the conversion of high mannose 1 into hybrid oligosaccharide 2 proceeded to 100% completion as assessed by MALDI‐TOF‐MS. Purification of the large polar oligosaccharide by gel filtration and silica gel chromatography afforded a 42% isolated yield of oligosaccharide 2. This enzyme‐catalyzed reaction can be utilized to produce rare hybrid oligosaccharides for biochemical and structural studies.
Chiral Lithium Salts of Phosphoric Acids as Lewis Acid–Base Conjugate Catalysts for the Enantioselective Cyanosilylation of Ketones
Authors: Hatano Manabu , Ikeno Takumi , Matsumura Tokihiko , Torii Shinobu , Ishihara Kazuaki 
Published: July 2008

AbstractThe catalytic enantioselective cyanosilylation of aromatic ketones was developed by using chiral lithium salts of (R)‐BINOL‐ or (S)‐BINAM‐derived phosphoric acid compounds. In the presence of 10 mol% of chiral conjugate lithium salts, the corresponding tertiary cyanohydrins were obtained in high yields with moderate to high enantioselectivities. This is the first efficient example of asymmetric catalysis using lithium salts of synthetically useful chiral phosphoric acid compounds. A possible catalytic mechanism and transition states are also discussed as a preliminary working hypothesis.
A pK determination method for proteins from titration curves using principle component analysis
Authors: Shim Jaesool , Dutta Prashanta , Ivory Cornelius F. 
Published: July 2008

AbstractPrincipal component analysis (PCA) technique is used for the precise determination of pK values from titration curves of amphoteric molecules, such as proteins and amino acids. A regression model is developed based on the effective charge of amphoteric molecules. Partial domain method, a new algorithm, is introduced to minimize or remove errors in extracted pK values from experimental (titration curve) data with hidden errors, such as sampling errors or experimental uncertainties. For the validation of our algorithm, 3 pK values are determined from the titration curves of glutamic acid and lysine. The extracted pKs are in exact agreement with the original pKs if partial domain method is used to obtain pKs from an exact (uncertainty free) titration curve. In addition, the effects of various uncertainty levels (1%, 2% and 3% noise) in the experimental titration curves are tested using both partial and full domain methods. Analytic results show that partial domain method is very effective in reducing the errors in extracted pKs especially at larger value of redundant number. Next, partial domain based PCA method is applied to extract 5 pKs from the experimental titration curve of hen egg‐white lysozyme protein. These pK values are then used to simulate the isoelectric focusing of lysozyme protein in the presence of 25 biprotic ampholytes in a 2‐D (two‐dimensional) straight microchannel. The transient, as well as focused state behaviors of lysozyme protein are compared between original titration curve (20 pKs) and approximated titration curve (5 pKs) cases. Although there are minor differences at the early stages of focusing, the focusing time, position, and shapes of protein and ampholytes are identical at focused state. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Approximations for unsteady‐state diffusion and reaction in porous catalyst and their application to packed‐bed reactor
Authors: Kim Dong Hyun 
Published: July 2008

AbstractIn this study, three approximations for unsteady‐state diffusion, a linear adsorption, and a first‐order reaction in a catalyst particle are presented. The time‐domain approximations are based on a first‐, a second‐, and a third‐order approximation of the Laplace‐domain solution of the exact partial differential equation for the catalyst. All the coefficients in the approximate equations are obtained as explicit functions of the Thiele modulus and easy to evaluate. In reactor modeling with the approximations, it is observed that the ratio of the space time in the reactor and the diffusion time in the catalyst is also an important parameter affecting the accuracy of the resulting model. A longer space time or shorter diffusion time improves the prediction of the approximate reactor model so that even the first‐order approximation is found to be sufficiently accurate when the ratio is over 0.9. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Investigation of solid–gas reaction heat transformer system with the consideration of multistep reactions
Authors: Wang C. , Zhang P. , Wang R. Z. 
Published: July 2008

AbstractThe performance of solid–gas reaction heat transformer system using MnCl2 and CaCl2 was investigated with the consideration of multistep reactions between CaCl2 and NH3. The reactions between CaCl2 and NH3 could be CaCl2·2/4NH3 and CaCl2·4/8NH3. The simulated results were verified by the experimental data. From the analysis results, it was concluded that the two reactions between CaCl2 and NH3 existed simultaneously. The favored conditions for the simultaneous occurrence of multistep reactions were discussed. The main reaction in the system with the initial state of CaCl2·2NH3 and CaCl2·4NH3 were designated as the reaction of CaCl2·2/4NH3 and CaCl2·4/8NH3, respectively. It was concluded that high driving temperature TM, large relative gas volume, and large specific heat transfer area were the favored conditions for the simultaneous occurrence of multistep reactions in the systems both with the initial state of CaCl2·2NH3 and CaCl2·4NH3. High initial charging pressure P0 was favored for the system with the initial state of CaCl2·2NH3, while low P0 was favored for the system with the initial state of CaCl2·4NH3. The impacts of the simultaneous occurrence of multistep reactions on the system performance indicators [temperature lift, specific power, and system coefficient of performance (COP)] were also investigated in this article. It was concluded that the occurrence of the reaction of CaCl2·4/8NH3 for the initial state of CaCl2·2NH3 led to better system performance, i.e., larger temperature lift, larger specific power, and larger system COP. However, the occurrence of the reaction of CaCl2·2/4NH3 for the initial state of CaCl2·4NH3 would lead to lower specific power. The temperature lift and system COP were larger for the initial state of CaCl2·4NH3; while the cycle period was shorter for the initial state of CaCl2·2NH3. © 2008 American Institute of Chemical Engineers AIChE J, 2008
COMT val158met modulates association between brain white matter architecture and IQ
Authors: Li Jun , Yu Chunshui , Li Yonghui , Liu Bing , Liu Yong , Shu Ni , Song Ming , Zhou Yuan , Zhu Wanlin , Li Kuncheng , Jiang Tianzi 
Published: July 2008

AbstractThe intelligence quotient (IQ) is typically associated with the architecture of gray and white matter in specific brain regions, and this association appears to be genetically based. However, specific sources of genetic variation for the association have not been studied extensively. Using diffusion tensor imaging in 15 mental retardation patients and 80 healthy volunteers, we studied the association between white matter architecture and IQ and also investigated the effects of COMT val158met on this association. The results showed that fractional anisotropy (FA) values in the prefrontal lobe and the hippocampus formation were associated with IQ and that val158met may affect this association. Subjects who were val homozygous showed steeper slopes for regression of the FA value on IQ than met carriers. Our findings suggest that COMT val158met may contribute to intelligence by affecting the association between IQ and the white matter architecture in the prefrontal lobe and the hippocampal formation. © 2008 Wiley‐Liss, Inc.
Taste difference thresholds for monosodium glutamate and sodium chloride in pigtail macaques (Macaca nemestrina) and spider monkeys (Ateles geoffroyi)
Authors: Laska Matthias , Persson Suorra Josefin , Bautista Rosa Mariela Rivas , Hernandez Salazar Laura Teresa 
Published: July 2008

AbstractThe purpose of this study was to determine taste difference thresholds for monosodium glutamate (MSG) and sodium chloride (NaCl) in pigtail macaques (Macaca nemestrina) and spider monkeys (Ateles geoffroyi). Using a two‐bottle preference test of brief duration, three animals of each species were presented with four different reference concentrations of 50, 100, 200, and 400 mM of a tastant and tested for their ability to discriminate these from lower concentrations of the same tastant. The just noticeable differences (JNDs), expressed as Weber ratios (ΔI/I), were found to range from 0.1 to 0.5 for MSG and 0.2 to 0.45 for NaCl in the pigtail macaques, with a significant tendency for higher Weber ratios with higher reference concentrations. In the spider monkeys, JNDs ranged from 0.15 to 0.4 for MSG and 0.1 to 0.25 for NaCl, with Weber ratios staying fairly constant across the reference concentrations tested. Thus, the JNDs were found to be generally similar in both species and to be at least as low as those found in humans for MSG and NaCl, as well as those found in spider monkeys for sucrose. The results support the assumption that both pigtail macaques and spider monkeys may use differences in perceived intensity of MSG and NaCl as a criterion for food selection. Am. J. Primatol. 70:839–847, 2008. © 2008 Wiley‐Liss, Inc.
Female social dynamics in a provisioned free‐ranging band of the Sichuan snub‐nosed monkey (Rhinopithecus roxellana) in the Qinling mountains, China
Authors: Zhang Peng , Watanabe Kunio , Li Baoguo 
Published: July 2008

AbstractLittle information is available on the social dynamics of the Sichuan snub‐nosed monkeys (Rhinopithecus roxellana). Here, we provide 5‐year observational data on a provisioned free‐ranging band in the Qinling Mountains, central China, from October 2001 to December 2005. The results of this study suggested that females place a high priority on maintaining long‐term relationships with other female in their one‐male units (OMUs). Females had more social interactions with unit members than with nonunit individuals. They showed relatively high rates of affiliation with their unit females, intermediate levels with the resident males, and low levels with individuals outside the unit. Females had few interactions with other resident males. Social interactions, especially affiliative interactions, were more symmetrical between focal females and their unit females than between focal females and the resident males. Thus female social interactions appeared to resemble those of other female‐bonded primate societies. On the other hand, female transfers occurred sometimes. We recorded 11 cases of female immigration and 5 cases of female disappearance, 1 case of female intraband shift, and 2 cases of “merging of OMUs,” which suggested that unit females might be loose‐knit in this species. We discussed influencing factors on female Sichuan snub‐nosed monkey social dynamics, by comparing them with those of Hamadryas and gelada baboons that also have multilevel societies. Am. J. Primatol. 70:1013–1022, 2008. © 2008 Wiley‐Liss, Inc.
Food transfer in common marmosets: parents change their tolerance depending on the age of offspring
Authors: Saito Atsuko , Izumi Akihiro , Nakamura Katsuki 
Published: July 2008

AbstractFood transfer is considered to provide infants with additional nutrients during weaning, and in fact, its frequency peaks around this time. However, the mechanisms underlying such food transfer remain unclear. In this study, we investigated whether adult common marmosets (Callithrix jacchus) change their tolerance to offspring begging for food depending on the offspring's age. We used four families consisting of breeding pairs, older offspring (29–49 weeks old), and younger offspring (7–15 weeks old). To directly compare the responses of a parent with its older and younger offspring, we placed one parent and one offspring in a testing space at one time. We presented foods where only the parent could reach them to ensure that the foods were transferred from the parent to offspring. Younger offspring showed more interest in food being held by the parents than older offspring. Parents refused older offspring more frequently than younger offspring and transferred food more often to younger offspring than to older offspring. There was no difference in all behavioral categories between fathers and mothers. These results suggest that both fathers and mothers are more tolerant to weanlings, but their tolerance decreases as offspring mature. Am. J. Primatol. 70:999–1002, 2008. © 2008 Wiley‐Liss, Inc.
Assessing mandibular shape variation within Gigantopithecus using a geometric morphometric approach
Authors: Miller Steven F. , White Jessica L. , Ciochon Russell L. 
Published: July 2008

AbstractThis study provides a survey of mandibular shape in a sample of extant hominoids (Pan, Gorilla, Pongo, and Hylobates), as well as extinct Asian and Eurasian taxa (Ouranopithecus, Sivapithecus, and Gigantopithecus) in order to compare overall shape similarity. Results presented call into question differences in mandible shape recently used to distinguish Gigantopithecus giganteus from Gigantopithecus blacki and to justify resurrecting a different generic designation, “Indopithecus,” for the former. It is concluded that while the two large‐bodied Asian taxa may have been adapted to slightly different dietary niches with different geographic and temporal ranges, the unique mandibular/dental characters that the two taxa share should not be viewed as independent evolutionary developments. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
What is it going to be? Pattern and potential function of natal coat change in sexually dichromatic redfronted lemurs (Eulemur fulvus rufus)
Authors: Barthold Julia , Fichtel Claudia , Kappeler Peter 
Published: July 2008

AbstractIn some primate species, pelage colorations at birth contrast with adult colorations. The intensity of natal coats and their phylogenetic distribution is highly variable within primates. Natal coat coloration seems to change to adult coloration in most species when infants become independent from their mothers, but an accepted functional explanation for natal coats is not available. Here we describe pelage coloration change in sexually dichromatic redfronted lemurs (Eulemur fulvus rufus) in Kirindy Forest, and propose a new functional hypothesis for this phenomenon. In this species, infants are born with adult male coloration and female infants subsequently undergo a change in coloration. Using digital pictures and behavioral data collected on eight mother‐offspring dyads from birth until the end of the coloration change, we 1) described timing and pattern of pelage developmentin redfronted lemur infants and 2) examined behavioral developmental correlates of the coloration change. The color change took place between 7 and 17 weeks of age and coincided with advanced physical independence; a pattern also found in monochromatic primate species with natal coats. No behavioral differences between male and female infants were found. Hypotheses about the ultimate function of natal coats focusing on enhanced infant care or reduced infanticide risk did not explain the pelage change in redfronted lemurs. The natal pelage pattern in this species may instead serve as sexual mimicry. Accordingly, female infants may mimic males during the most vulnerable developmental phase to avoid sex‐specific aggression by adult females in a species with intense female–female aggression and competition. Am J Phys Anthropol, 2009. © 2008 Wiley‐Liss, Inc.
Craniometric variation of the Ainu: An assessment of differential gene flow from Northeast Asia into Northern Japan, Hokkaido
Authors: Hanihara Tsunehiko , Yoshida Kohzo , Ishida Hajime 
Published: July 2008

AbstractIn and after the latest Neolithic period in Japan (∼B.P. 2,300 years), there were two distinct waves of migration from eastern Asia. One is well known as successive episodes in which indigenous inhabitants of main‐island Japan were intruded on by new arrivals with advanced technology, and of a different genetic stock. Another migration of people and culture, identified as the Okhotsk culture, reached the northeastern part of Hokkaido. As opposed to main‐island Japan, the morphological continuity from the Neolithic to recent inhabitants in Hokkaido (Ainu) is notable, so that the evidence of admixture easily could have escaped notice. In this study, the effects of gene flow from an outside source on the pattern of among‐group variation of Hokkaido Ainu are examined by means of two models. One is the R‐matrix model comparing observed and expected craniometric variation for estimating differential external gene flow into a region. The other is a simple simulation model that estimates admixture in a population with two parental populations. The two approaches give similar results. The results suggest the possibility of admixture between the migrants from Northeast Asia, the Okhotsk culture people, and the indigenous inhabitants in Hokkaido during the 5th to 12th centuries A.D., at least in northeastern Hokkaido. Such gene flow may have a certain degree of effect on the genetic structure of recent Ainu. The findings further suggest morphological heterogeneity in Northeast Asia during the Holocene that has relevance for understanding the morphological heterogeneity seen through time in the New World. Am J Phys Anthropol 2008. © 2008 Wiley‐Liss, Inc.
Brief communication: Skeletal biology past and present: Are we moving in the right direction?
Authors: Hens Samantha M. , Godde Kanya 
Published: July 2008

AbstractIn 1982, Spencer's edited volume A History of American Physical Anthropology: 1930–1980 allowed numerous authors to document the state of our science, including a critical examination of skeletal biology. Some authors argued that the first 50 years of skeletal biology were characterized by the descriptive‐historical approach with little regard for processual problems and that technological and statistical analyses were not rooted in theory. In an effort to determine whether Spencer's landmark volume impacted the field of skeletal biology, a content analysis was carried out for the American Journal of Physical Anthropology from 1980 to 2004. The percentage of skeletal biology articles is similar to that of previous decades. Analytical articles averaged only 32% and are defined by three criteria: statistical analysis, hypothesis testing, and broader explanatory context. However, when these criteria were scored individually, nearly 80% of papers attempted a broader theoretical explanation, 44% tested hypotheses, and 67% used advanced statistics, suggesting that the skeletal biology papers in the journal have an analytical emphasis. Considerable fluctuation exists between subfields; trends toward a more analytical approach are witnessed in the subfields of age/sex/stature/demography, skeletal maturation, anatomy, and nonhuman primate studies, which also increased in frequency, while paleontology and pathology were largely descriptive. Comparisons to the International Journal of Osteoarchaeology indicate that there are statistically significant differences between the two journals in terms of analytical criteria. These data indicate a positive shift in theoretical thinking, i.e., an attempt by most to explain processes rather than present a simple description of events. Am J Phys Anthropol 2008. © 2008 Wiley‐Liss, Inc.