bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Zintl Compound Ca5Al2Sb6 for Low‐Cost Thermoelectric Power Generation
Authors: Toberer Eric S. , Zevalkink Alexandra , Crisosto Nicole , Snyder G. Jeffrey 
Published: September 2010

AbstractUnderstanding transport in Zintl compounds is important due to their unusual chemistry, structural complexity, and potential for good thermoelectric performance. Resistivity measurements indicate that undoped Ca5Al2Sb6 is a charge‐balanced semiconductor with a bandgap of 0.5 eV, consistent with Zintl–Klemm charge counting rules. Substituting divalent calcium with monovalent sodium leads to the formation of free holes, and a transition from insulating to metallic electronic behavior is observed. Seebeck measurements yield a hole mass of ∼2me, consistent with a structure containing both ionic and covalent bonding. The structural complexity of Zintl compounds is implicated in their unusually low thermal conductivity values. Indeed, Ca5Al2Sb6 possesses an extremely low lattice thermal conductivity (0.6 W mK−1 at 850 K), which approaches the minimum thermal conductivity limit at high temperature. A single parabolic band model is developed and predicts that Ca4.75Na0.25Al2Sb6 possesses a near‐optimal carrier concentration for thermoelectric power generation. A maximum zT > 0.6 is obtained at 1000 K.Beyond thermoelectric applications, the semiconductor Ca5Al2Sb6 possesses a 1D covalent structure which should be amenable to interesting magnetic interactions when appropriately doped.
Kinetics‐Controlled Formation of Gold Clusters Using a Quasi‐Biological System
Authors: Zhang Ming‐Xi , Cui Ran , Tian Zhi‐Quan , Zhang Zhi‐Ling , Pang Dai‐Wen 
Published: September 2010

AbstractBy kinetically controlling a biomimetic reduction in a quasi‐biological system (an aqueous solution containing electrolyte, peptide, and coenzyme), water‐soluble, glutathione‐capped Au clusters with a mean diameter of 1.3 nm are successfully synthesized via a new route. Opportunities that facilitate the control of the reaction are created in such a quasi‐biological system. The relatively slow rate of the biomimetic reduction, the pH‐dependent reducibility of the reducing agent, and the favorable structure of the capping molecules conspire together for the realization of a kinetics‐controlled formation of the Au clusters under mild conditions. Compared to existing methods of synthesizing gold clusters by stoichiometrically controlling the molar ratio of the Au atoms and the ligands, our current method is based on slowing down the reduction of the Au precursors in the initial stage by adjusting the activity of the reducing agent in real time, instead of using a strong reducing agent such as NaBH4. This strategy of rationally utilizing biological or biomimetic processes with unique features to provide a beneficial complement to conventional chemical syntheses could open a new way for the sustainable development of nanotechnology.
Protein Particles Formed by Protein Activation and Spontaneous Self‐Assembly
Authors: Mak Wing Cheung , Georgieva Radostina , Renneberg Reinhard , Bäumler Hans 
Published: September 2010

AbstractIn this article, a non‐chemical crosslinking method is used to produce pure protein microparticles with an innovative approach, so‐called protein activation spontaneous and self‐assembly (PASS). The fabrication of protein microparticles is based on the idea of using the internal disulfide bridges within protein molecules as molecular linkers to assemble protein molecules into a microparticle form. The assembly process is triggered by an activating reagent–dithiothreitol (DTT), which only involved in the intermediate step without being incorporated into the resulting protein microparticles. Conventional protein microparticle fabrication methods usually involve emulsification process and chemical crosslink reactions using amine reactive reagents such as glutaraldehdye or EDC/NHS. The resulting protein microparticles are usually having various size distributions. Most importantly crosslinking reactions using amine reactive reagents will result in producing protein microparticles with undesired properties such as auto‐fluorescence and high toxicity. In contrast to the conventional methods, our technology provides a simple and robust method to produce highly homogeneous, stable and non‐fluorescence pure protein microparticles under mild conditions at physiological pH and temperature. The protein microparticles are found to be biodegradable, non‐toxic to MDCK cells and with preserved biological activities. Results on the cytotoxcity study and enzyme function demonstrate the potential applications of the protein microparticles in the area of pharmaceutics and analytical chemistry.
Carbon Nanotubes: High Electromechanical Response of Ionic Polymer Actuators with Controlled‐Morphology Aligned Carbon Nanotube/Nafion Nanocomposite Electrodes (Adv. Funct. Mater. 19/2010)
Authors: Liu Sheng , Liu Yang , Cebeci Hülya , de Villoria Roberto Guzmán , Lin Jun‐Hong , Wardle Brian L. , Zhang Q. M. 
Published: September 2010

AbstractRecent advances in fabricating controlled‐morphology vertically aligned carbon nanotubes (VA‐CNTs) with ultrahigh volume fraction create unique opportunities for markedly improving the electromechanical performance of ionic polymer conductor network composite (IPCNC) actuators. Continuous paths through inter‐VA‐CNT channels allow fast ion transport, and high electrical conduction of the aligned CNTs in the composite electrodes lead to fast device actuation speed (>10% strain/second). One critical issue in developing advanced actuator materials is how to suppress the strain that does not contribute to the actuation (unwanted strain) thereby reducing actuation efficiency. Here, experiments demonstrate that the VA‐CNTs give an anisotropic elastic response in the composite electrodes, which suppresses the unwanted strain and markedly enhances the actuation strain (>8% strain under 4 V). The results reported here suggest pathways for optimizing the electrode morphology in IPCNCs using ultrahigh volume fraction VA‐CNTs to further enhanced performance.
Temperature‐Responsive Substrates: Adhesion and Mechanical Properties of PNIPAM Microgel Films and Their Potential Use as Switchable Cell Culture Substrates (Adv. Funct. Mater. 19/2010)
Authors: Schmidt Stephan , Zeiser Michael , Hellweg Thomas , Duschl Claus , Fery Andreas , Möhwald Helmuth 
Published: September 2010

AbstractThermoresponsive poly(N‐isopropylacrylamide) (PNIPAM) microgel films are shown to allow controlled detachment of adsorbed cells via temperature stimuli. Cell response occurs on the timescale of several minutes, is reversible, and allows for harvesting of cells in a mild fashion. The fact that microgels are attached non‐covalently allows using them on a broad variety of (charged) surfaces and is a major advantage as compared to approaches relying on covalent attachment of active films. In the following, the microgels’ physico‐chemical parameters in the adsorbed state and their changes upon temperature variation are studied in order to gain a deeper understanding of the involved phenomena. By means of atomic force microscopy (AFM), the water content, mechanical properties, and adhesion forces of the microgel films are studied as a function of temperature. The analysis shows that these properties change drastically when crossing the critical temperature of the polymer film, which is the basis of the fast cell response upon temperature changes. Furthermore, nanoscale mechanical analysis shows that the films posses a nanoscopic gradient in mechanical properties.
Architecture of Supramolecular Soft Functional Materials: From Understanding to Micro‐/Nanoscale Engineering
Authors: Li Jing‐Liang , Liu Xiang‐Yang 
Published: September 2010

AbstractThis article gives an overview of the current progress of a class of supramolecular soft materials consisting of fiber networks and the trapped liquid. After discussing the up‐to‐date knowledge on the types of fiber networks and the correlation to the rheological properties, the gelation mechanism turns out to be one of the key subjects for this review. In this concern, the following two aspects will be focused upon: the single fiber network formation and the multi‐domain fiber network formation of this type of material. Concerning the fiber network formation, taking place via nucleation, and the nucleation‐mediated growth and branching mechanism, the theoretical basis of crystallographic mismatch nucleation that governs fiber branching and formation of three‐dimensional fiber networks is presented. In connection to the multi‐domain fiber network formation, which is governed by the primary nucleation and the subsequent formation of single fiber networks from nucleation centers, the control of the primary nucleation rate will be considered. Based on the understanding on the the gelation mechanism, the engineering strategies of soft functional materials of this type will be systematically discussed. These include the control of the nucleation and branching‐controlled fiber network formation in terms of tuning the thermodynamic driving force of the gelling system and introducing suitable additives, as well as introducing ultrasound. Finally, a summary and the outlook of future research on the basis of the nucleation‐growth‐controlled fiber network formation are given.
Nanostructure and Optoelectronic Characterization of Small Molecule Bulk Heterojunction Solar Cells by Photoconductive Atomic Force Microscopy
Authors: Dang Xuan‐Dung , Tamayo Arnold B. , Seo Junghwa , Hoven Corey V. , Walker Bright , Nguyen Thuc‐Quyen 
Published: September 2010

AbstractPhotoconductive atomic force microscopy is employed to study the nano­scale morphology and optoelectronic properties of bulk heterojunction solar cells based on small molecules containing a benzofuran substituted diketopyrrolopyrrole (DPP) core (3,6‐bis(5‐(benzofuran‐2‐yl)thiophen‐2‐yl)‐2,5‐bis(2‐ethylhexyl)pyrrolo[3,4‐c]pyrrole‐1,4‐dione, DPP(TBFu)2, and [6,6]–phenyl‐C71‐butyric acid methyl ester (PC71BM), which were recently reported to have power conversion efficiencies of 4.4%. Electron and hole collection networks are visualized for blends with different donor:acceptor ratios. Formation of nanostructures in the blends leads to a higher interfacial area for charge dissociation, while maintaining bicontinuous collection networks; conditions that lead to the high efficiency observed in the devices. An excellent agreement between nanoscale and bulk open‐circuit voltage measurements is achieved by surface modification of the indium tin oxide (ITO) substrate by using aminopropyltrimethoxysilane. The local open‐circuit voltage is linearly dependent on the cathode work function. These results demonstrate that photoconductive atomic force microscopy coupled with surface modification of ITO substrate can be used to study nanoscale optoelectronic phenomena of organic solar cells.
Direct C‐3‐Alkenylation of Quinolones via Palladium‐Catalyzed CH Functionalization
Authors: Li Mingzong , Li Liangxi , Ge Haibo 
Published: September 2010

AbstractAn unprecedented C‐3‐alkenylation of quinolones was reported through palladium‐catalyzed CH functionalization with 1% catalyst loading. This method provides an efficient route to a variety of new quinolone derivatives.
Making use of process tomography data for multivariate statistical process control
Authors: Boonkhao Bundit , Li Rui F. , Wang Xue Z. , Tweedie Richard J. , Primrose Ken 
Published: September 2010

AbstractA novel strategy for making effective use of on‐line process tomography measurements for process monitoring is described. The electrical resistance tomography (ERT) sensing system equipped with sixteen electrodes provides 104 conductivity measurements every 25 ms. The data has traditionally been used for construction of images for display purpose. In this study, ERT data was used for multivariate statistical process control. Data at predefined normal operational conditions was processed using principal component analysis. The compressed data was used to derive two statistics, T2 and squared prediction error (SPE). T2 and SPE charts predict the probability that the process being monitored has undergone statistically significant changes from previous state or the so‐called normal operational state, in terms of mixing quality. The methodology is illustrated by reference to a case study of a sunflower oil/water emulsion process. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Metacarpal trabecular architecture variation in the chimpanzee (Pan troglodytes): Evidence for locomotion and tool‐use?
Authors: Lazenby Richard A. , Skinner Matthew M. , Hublin Jean‐Jacques , Boesch Christophe 
Published: September 2010

AbstractTrabecular architecture was assessed by 3D micro‐computed tomography from spherical volumes of interest located within the head and base of metacarpals (MC) 1, 2, and 5 fromn= 19 adult common chimpanzees. Two subspecies, West AfricanPan troglodytes verusfrom the Taï Forest, Côte d'Ivoire (n= 12) and Central AfricanP. t. troglodytesfrom Cameroon (n= 7), were studied. For the combined sample, the metacarpal head is distinguished by greater bone volume fraction across all metacarpals, though the MC 1 is distinctive in having thicker, more plate‐like trabeculae. The architecture in the MC 2 and MC 5 can be related to strains associated with terrestrial knuckle‐walking. In particular, the relatively robust MC 5 head architecture may result from functional loading incurred during braking and use of a palm‐in hand posture. Examining differences between samples, we found that the Cameroon chimpanzees possess a more robust architecture across all metacarpals in the form of greater bone volume fraction, higher connectivity, and somewhat more plate‐like structure. These differences are not explicable in terms of population distinctions in body size or daily travel distance, but possibly reflect a combination of more terrestrial knuckle‐walking in the Cameroon sample and more diverse hand postures and precision handling required of nut‐cracking in West African chimpanzees. Am J Phys Anthropol, 2011. © 2010 Wiley‐Liss, Inc.
Age estimation from stages of epiphyseal union in the presacral vertebrae
Authors: Cardoso Hugo F.V. , Ríos Luis 
Published: September 2010

AbstractThe presacral vertebrae have various secondary centers of ossification, whose timing of fusion can be used for age estimation of human skeletal remains up to the middle to the latter third decade. However, detailed information about the age at which these secondary centers of ossification fuse has been lacking. In this study, the timing of epiphyseal union in presacral vertebrae was studied in a sample of modern Portuguese skeletons (57 females and 47 males) between the ages of 9 and 30, taken from the Lisbon documented skeletal collection. A detailed photographic record of these epiphyses and the age ranges for the different stages of epiphyseal union are provided. Partial union of epiphyses was observed from 11 to 27 years of age. In general, centers of ossification begin to fuse first in the cervical and lumbar vertebrae, followed by centers of ossification in the thoracic region. The first center of ossification to complete fusion is usually that of the mammillary process in lumbar vertebrae. This is usually followed by that of the transverse process, spinous transverse process, and annular ring, regardless of vertebra type. There were no statistically significant sex differences in timing of fusion, but there was a trend toward early maturation in females for some vertebra or epiphyses. Bilateral epiphyses did not show statistically significant differences in timing of fusion. This study offers information on timing of fusion of diverse epiphyseal locations useful for age estimation of complete or fragmented human skeletal remains. Am J Phys Anthropol, 2011. © 2010 Wiley‐Liss, Inc.
Human ancient and extant mtDNA from the Gambier Islands (French polynesia): Evidence for an early Melanesian maternal contribution and new perspectives into the settlement of Easternmost Polynesia
Authors: Deguilloux Marie‐France , Pemonge Marie‐Hélène , Dubut Vincent , Hughes Sandrine , Hänni Catherine , Chollet Lionel , Conte Eric , Murail Pascal 
Published: September 2010

AbstractMolecular anthropology has been widely used to infer the origin and processes of the colonization of Polynesia. However, there are still a lack of representative geographical studies of Eastern Polynesia and unchallenged genetic data about ancient Polynesian people. The absence of both of these elements prevents an accurate description of the demographic processes of internal dispersion within the Polynesian triangle. This study provides a twofold analysis of ancient and modern mtDNA in the eastern part of French Polynesia: the Gambier Islands. The paleogenetic analyses conducted on burials of the Temoe Atoll (14th−17th centuries) represent the first fully authenticated ancient human sequences from Polynesia. The identification of the “Melanesian” Q1 mtDNA lineage in ancient human remains substantiates the Near Oceanic contribution to the early gene pool of this region. Modern samples originate from Mangareva Island. Genealogical investigations enable us to reliably identify the conservation of the Melanesian component in Easternmost Polynesia, despite recent European colonization. Finally, the identification of rare mutations in sequences belonging to haplogroup B4a1a1a provides new perspectives to the debate on the internal peopling of the Polynesian region. Altogether, the results laid out in our study put the emphasis on the necessity of controlled sampling when discussing the internal settlement of Polynesia. Am J Phys Anthropol, 2011. © 2010 Wiley‐Liss, Inc.
Ancient DNA evidence supports the contribution of Di‐Qiang people to the han Chinese gene pool
Authors: Zhao Yong‐Bin , Li Hong‐Jie , Li Sheng‐Nan , Yu Chang‐Chun , Gao Shi‐Zhu , Xu Zhi , Jin Li , Zhu Hong , Zhou Hui 
Published: September 2010

AbstractHan Chinese is the largest ethnic group in the world. During its development, it gradually integrated with many neighboring populations. To uncover the origin of the Han Chinese, ancient DNA analysis was performed on the remains of 46 humans (∼1700 to 1900 years ago) excavated from the Taojiazhai site in Qinghai province, northwest of China, where the Di‐Qiang populations had previously lived. In this study, eight mtDNA haplogroups (A, B, D, F, M*, M10, N9a, and Z) and one Y‐chromosome haplogroup (O3) were identified. All analyses show that the Taojiazhai population presents close genetic affinity to Tibeto‐Burman populations (descendants of Di‐Qiang populations) and Han Chinese, suggesting that the Di‐Qiang populations may have contributed to the Han Chinese genetic pool. Am J Phys Anthropol, 2011. © 2010 Wiley‐Liss, Inc.
Brief communication: MaqFACS: A muscle‐based facial movement coding system for the rhesus macaque
Authors: Parr L.A. , Waller B.M. , Burrows A.M. , Gothard K.M. , Vick S.J. 
Published: September 2010

AbstractOver 125 years ago, Charles Darwin (1872) suggested that the only way to fully understand the form and function of human facial expression was to make comparisons with other species. Nevertheless, it has been only recently that facial expressions in humans and related primate species have been compared using systematic, anatomically based techniques. Through this approach, large‐scale evolutionary and phylogenetic analyses of facial expressions, including their homology, can now be addressed. Here, the development of a muscular‐based system for measuring facial movement in rhesus macaques (Macaca mulatta) is described based on the well‐known FACS (Facial Action Coding System) and ChimpFACS. These systems describe facial movement according to the action of the underlying facial musculature, which is highly conserved across primates. The coding systems are standardized; thus, their use is comparable across laboratories and study populations. In the development of MaqFACS, several species differences in the facial movement repertoire of rhesus macaques were observed in comparison with chimpanzees and humans, particularly with regard to brow movements, puckering of the lips, and ear movements. These differences do not seem to be the result of constraints imposed by morphological differences in the facial structure of these three species. It is more likely that they reflect unique specializations in the communicative repertoire of each species. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.
The influence of enzymatic treatment on the surface modification of PET fibers
Authors: Kardas Iwona , Lipp‐Symonowicz Barbara , Sztajnowski Slawomir 
Published: September 2010

AbstractThe paper deals with the assessment of the surface modification of glossy continuous poly(ethylene terephthalate) fibers from the point of view of changes in their surface structure in terms of its micro‐topography and the molecular and supermolecular structure of the filament surface layers. The performed SEM and AFM investigations have shown differences in the fiber surface carving before and after modification (smoothing or increased roughness), depending on the type of applied enzymatic preparation. Measurements with the use of the ATR‐IR method have shown changes in the physicochemical character of the investigated fiber surface. The cleavage of the ester bonds in PET macromolecular chains, resulting from the modifications used, leads to the formation of reactive OH and COOH groups. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Molecular weight‐dependent antifungal activity and action mode of chitosan against Fulvia fulva (cooke) ciffrri
Authors: Li Meiqin , Chen Xiguang , Liu Jianmin , Zhang Weifen , Tang Xuexi 
Published: September 2010

AbstractAntifungal activities of chitosans (CTS) with different molecular weights (Mw) and different concentrations against Fulvia fulva (cooke) ciffrri (F. fulva) causing leaf mold in tomato plants were studied in vitro and in vivo; the action mode and its inhibition at different stages during the life cycle of F. fulva were observed. The results showed that: (1) in vitro, CTS exhibited strong antifungal activity against F. fulva, especially for the medium Mw (213 and 499 KDa) CTS. Almost complete inhibition of F. fulva conidia germination and mycelia colony radial growth was found when CTS was at concentration of 0.5 and 2 mg mL−1, respectively; however, inhibitory effect on sporulation was not very obvious for all CTSs tested in this experiment. In vivo, CTS of 213 KDa CTS at 6 mg mL−1 concentration produced stronger antifungal effect than others. (2) The morphological study by scanning electron microscope (SEM) showed that CTS could induce the hyphal swelling, and the surface of hypha which was treated with low Mw (82 KDa) chitosan was smooth, but was rough treated with high Mw (1320 KDa) chitosan. The further study using a confocal laser scanning microscopy (CLSM) coupled with fluorescein isothiocyanate (FITC)‐fluorescence detection system showed fluorescence of the FITC‐labeled chitosans of which Mws were below 500 KDa could enter into the inner of hypha; however, 1320 KDa chitosan was blocked off the outer of hypha. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2011