bluuebunny/crossref_metadata_2025_split huggingface dataset:
The modification of graphene with alcohols and its use in shape memory polyurethane composites
Authors: Oh Seong Min , Oh Kyung Min , Dao Trung Dung , Lee Hyung‐il , Jeong Han Mo , Kim Byung Kyu 
Published: September 2012

AbstractGraphene prepared by the thermal reduction of graphite oxide was modified by reactions with methanol or 1‐butanol using aqueous HBF4 solution as a catalyst. Results showed that the reaction created hydroxyl groups on the graphene and at the same time reduced the number of defects. Gravimetry, thermogravimetry, X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy showed that the alcohols had reacted with epoxide groups on graphene. Raman spectroscopy showed that the defects in the graphene were repaired through other accompanying reactions. The reinforcing effect of graphene, observed in the tensile properties and the shape memory behavior of graphene/polyurethane composites, was increased when the graphene was modified with methanol. However, decreases in density and glass transition temperature were evident for the composites made with alcohol‐modified graphene. These results show that the newly created hydroxyl groups on graphene produce effective covalent bonds with the polyurethane chains of the matrix; however, the increased number of bonds restricts the rearrangement of the matrix molecules for dense packing. The covalent bonds between graphene and polyurethane chains enhanced shape recoverability and reduced the hysteresis brought about by repeated thermomechanical cycles. Copyright © 2012 Society of Chemical Industry
Synthesis, structure, and properties of chiral liquid crystal monomers and polymers based on menthol
Authors: Hu Jian‐She , Li Dan , Zhang Wen‐Chang , Meng Qing‐Bao 
Published: September 2012

AbstractTo study structure–mesomorphism relationships of the monomers and polymers based on menthol, four new chiral monomers (M1–M4) and the corresponding homopolymers (P1–P4) with menthyl group were synthesized. Their chemical structures, formula, phase behavior, and thermal stability were characterized by FTIR, 1H NMR, 13C NMR, elemental analyses, differential scanning calorimetry, polarizing optical microscopy, X‐ray diffraction, and thermogravimetric analysis. The selective reflection of light was investigated with ultraviolet/visible spectrometer. The influence of the mesogenic core rigidity, spacer length, and menthyl steric effect on the mesomorphism of M1–M4 and P1–P4 was examined. By inserting a flexible spacer between the mesogenic core and the terminal menthyl groups, four target monomers and polymers could form the expected mesophase. Moreover, their melting temperature (Tm), glass transition temperature (Tg), clearing temperature (Ti), and mesophase range (ΔT) increased with increasing the mesogenic core rigidity; whereas the Tm and Tg decreased, Ti and ΔT increased with an increase of the spacer length. M1 and M2 showed monotropic and enantiotropic cholesteric phase, respectively, whereas M3 and M4 all revealed chiral smectic C (SmC*), cholesteric and cubic blue phases. In addition, with increasing temperature, the selective reflection of light shifted to the long wavelength region at the SmC* phase range and to the short wavelength region at the cholesteric range, respectively. P1 and P2 only showed a smectic A (SmA) phase, whereas P3 and P4 exhibited the SmC* and SmA phases. All the obtained polymers had very good thermal stability. © 2012 Wiley Periodicals, Inc. J. Polym. Sci. Part A: Polym Chem, 2012
Efficient crystalline Si/organic hybrid heterojunction solar cells
Authors: Liu Qiming , Khatri Ishwor , Ishikawa Ryo , Ueno Keiji , Shirai Hajime 
Published: September 2012

AbstractEfficient crystalline silicon (c‐Si) heterojunction solar cells with conductive poly(ethylene dioxythiophene):poly(styrene sulfonate)(PEDOT:PSS) and graphene oxide (GO) are demonstrated using device structures of c‐Si/GO/PEDOT:PSS/Ag and c‐Si/PEDOT:PSS:GO composite/Al. The power‐conversion efficiency η increased from 8.76 to 9.27% under illumination of AM1.5 100 mW/cm2 simulated solar light by adjusting the GO thickness for the n‐Si/GO/PEDOT:PSS heterojunction solar cells. η also increased to 10.6% for the n‐Si/PEDOT:PSS:GO composite devices by adjusting the GO mixing concentration.The GO addition to conductive PEDOT:PSS suppressed electron recombination and/or promoted the hole current at the anode. The soluble PEDOT:PSS:GO composite is promising as a hole‐transporting transparent conducting layer for c‐Si/organic junction photovoltaic applications. The uniform coating of poly(3‐hexylthiophene‐2,5‐dily) (P3HT) and PEDOT:PSS on textured hydrophobic c‐Si wafer was observed by the electrospray deposition. The textured related enhancement of the device performance is demonstrated (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chemical mist deposition of graphene oxide and PEDOT:PSS films for crystalline Si/organic heterojunction solar cells
Authors: Khatri Ishwor , Imamura Takashi , Uehara Akira , Ishikawa Ryo , Ueno Keiji , Shirai Hajime 
Published: September 2012

AbstractThe chemical mist deposition of graphene oxide (GO) and poly(3,4‐ethylenedioxythiophene):poly(stylenesulfonate) (PEDOT:PSS) were investigated on the crystalline silicon (c‐Si) substrate for the n‐type c‐Si/organic heterojunction solar cells. The uniform coating of GO flake with an average size of 1‐5 μm was obtained on the hydrophobic c‐Si wafer using deionized water as a solvent. The GO layer thickness could be controlled from a monolayer to a few tens of nanometres by vary‐ ing mist deposition time. The c‐Si/GO/ PEDOT:PSS heterojunction solar cells shows the efficiency improved from 8.75 to 9.27% with insertion of GO flakes a the PEDOT:PSS and c‐Si interface owing to the enhanced suppression of electron recombination and/or promotion of hole current at the anode. Furthermore, the CMD was also applied to coat conductive PEDOT:PSS films on the textured c‐Si. The η of 7.75% was obtained with a short‐circuit current of 34.22 mA/cm2, a open‐circuit voltage of 0.46 V, and a fill factor of 0.48. These findings imply that CMD is a promising method for the uniform deposition of both nanomaterials (GO) and conjugated polymer for the c‐Si/ organic heterojunction solar cells (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stable carbon isotope analysis of fluvial sediment fluxes over two contrasting C4‐C3 semi‐arid vegetation transitions
Authors: Puttock Alan , Dungait Jennifer A. J. , Bol Roland , Dixon Elizabeth R. , Macleod Christopher J. A. , Brazier Richard E. 
Published: September 2012

RATIONALEGlobally, many drylands are experiencing the encroachment of woody vegetation into grasslands. These changes in ecosystem structure and processes can result in increased sediment and nutrient fluxes due to fluvial erosion. As these changes are often accompanied by a shift from C4 to C3 vegetation with characteristic δ13C values, stable isotope analysis provides a promising mechanism for tracing these fluxes.METHODSInput vegetation, surface sediment and fluvially eroded sediment samples were collected across two contrasting C4‐C3 dryland vegetation transitions in New Mexico, USA. Isotope ratio mass spectrometric analyses were performed using a Carlo Erba NA2000 analyser interfaced to a SerCon 20–22 isotope ratio mass spectrometer to determine bulk δ13C values.RESULTSStable isotope analyses of contemporary input vegetation and surface sediments over the monitored transitions showed significant differences (p <0.05) in the bulk δ13C values of C4 Bouteloua sp. (grama) grassland, C3 Larrea tridentata (creosote) shrubland and C3 Pinus edulis/Juniperus monosperma (piñon‐juniper) woodland sites. Significantly, this distinctive δ13C value was maintained in the bulk δ13C values of fluvially eroded sediment from each of the sites, with no significant variation between surface sediment and eroded sediment values.CONCLUSIONSThe significant differences in bulk δ13C values between sites were dependent on vegetation input. Importantly, these values were robustly expressed in fluvially eroded sediments, suggesting that stable isotope analysis is suitable for tracing sediment fluxes. Due to the prevalent nature of these dryland vegetation transitions in the USA and globally, further development of stable isotope ratio mass spectrometry has provided a valuable tool for enhanced understanding of functional changes in these ecosystems. Copyright © 2012 John Wiley & Sons, Ltd.
The privileged burial of the Pava Pieve (Siena, 8th Century AD)
Authors: Ricci Paola , Mongelli Valeria , Vitiello Angelica , Campana Stefano , Sirignano Carmina , Rubino Mauro , Fornaciari Gino , Lubritto Carmine 
Published: September 2012

RATIONALEThe 6th archaeological excavation campaign performed at the 'Pieve di Pava' (San Giovanni d'Asso, Siena, Italy) unearthed a privileged stone burial of a single individual (US 2378), covered by a monolithic slab and placed in front of an altar. The skeletal remains of a young male (18–20 years old), not in anatomical connection, were found at the bottom floor of a tomb (160 cm long, 40 cm large and over 70 cm deep).METHODSA multidisciplinary study has been carried out concerning that privileged bone burial. The study combines paleopathology studies, stable isotope palaeodietary reconstruction, radiocarbon dating and archaeological analyses.RESULTS14 C dating of the skeleton revealed a date between 650 and 688 AD. Stable isotope analysis (δ18O, δ13C, δ15N) attested that he was probably a member of the local population, whose diet was rather rich in animal proteins. The paleopathological study diagnosed a case of acromesomelic dysplasia, a congenital anomaly with disproportion of the limbs. Archaeological evidence regarding the circular delimitation of the bones suggested that the skeleton was a secondary deposition, transported to the church in a sack.CONCLUSIONSWe argue that the relic was used for the re‐consecration of the church, following the restoration work in the 8th century. We conclude that the skeleton belonged to an eminent personage (e.g., either the member of a local elite family or a saint). Copyright © 2012 John Wiley & Sons, Ltd.
Palaeoenvironmental modelling of δ13C and δ15N values in the North Atlantic Islands: understanding past marine resource use
Authors: Jones J. R. , Mulville J. A. , McGill R. A. R. , Evershed R. P. 
Published: September 2012

RATIONALECarbon (δ13C) and nitrogen (δ15N) analysis has been extensively used to investigate the importance of marine foods in the diet of archaeological populations in the North Atlantic Islands; however, few faunal studies exist to aid the interpretation of results. Palaeoenvironmental modelling of δ13C and δ15N values is crucial in determining whether changes in the stable isotope values are a result of dietary change, rather than temporal or geographical fluctuations in carbon and nitrogen. Investigating faunal dietary behaviour can provide an insight into past foddering and land management strategies.METHODSDetailed sampling of wild and domestic species for bulk collagen analysis was undertaken in order to characterise geographical variations in δ13C and δ15N values in the Outer Hebrides and Orkney. Samples from the Neolithic to the Norse period were analysed to assess temporal and geographical variations in δ13C and δ15N values, in addition to determining the contribution of marine foods to the diet of local fauna.RESULTSA δ15N shift of 1‰ was observed between the Outer Hebrides and Orkney in the Neolithic and Iron Age. A geographical variation in δ13C values was observed in the Norse period between Orkney and the Outer Hebrides. Temporal fluctuations in δ13C and δ15N values demonstrate variations in foddering practices of sheep in the Outer Hebrides. Pig specimens from the Outer Hebrides demonstrated evidence of marine food consumption in the Iron Age.CONCLUSIONSFaunal dietary behaviour can act as a vital indicator of the importance of marine resources in the past. Characterisation of faunal δ13C and δ15N values geographically and temporally is crucial in our interpretation of human dietary behaviour. Copyright © 2012 John Wiley & Sons, Ltd.
An optimized matrix‐assisted laser desorption/ionization sample preparation using a liquid matrix, 3‐aminoquinoline/α‐cyano‐4‐hydroxycinnamic acid, for phosphopeptides
Authors: Fukuyama Yuko , Takeyama Kohei , Kawabata Shin‐ichirou , Iwamoto Shinichi , Tanaka Koichi 
Published: September 2012

RATIONALEA liquid matrix, 3‐aminoquinoline (3‐AQ)/α‐cyano‐4‐hydroxycinnamic acid (CHCA), introduced by Kolli et al. in 1996 for matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS), has been reported for peptides and proteins, oligonucleotides, oligosaccharides, and glycopeptides. However, it has not been validated for phosphopeptides.METHODSWe optimized sample preparation using 3‐AQ/CHCA for phosphopeptides. The sensitivity of six phosphopeptide species as isolated or in digests was systematically evaluated by using MALDI‐quadropole ion trap (QIT)‐time of flight (TOF) MS in positive and negative ion modes, and compared with the conventional methods using a solid matrix, 2,5‐dihydroxybenzoic acid (2,5‐DHB).RESULTSThe sensitivity of mono‐ and tetraphosphopeptides was improved 10‐ to 10 000‐fold with the optimized preparation method using 3‐AQ/CHCA compared with the conventional methods using 2,5‐DHB. Improvement by 3‐AQ/CHCA itself was 10‐fold. Adding ammonium dihydrogen phosphate or an analyte solvent composition was also effectively improved the sensitivity. Phosphopeptides in isolated form or in digests were detected at femto‐ or subfemtomole levels.CONCLUSIONSSensitivity of phosphopeptides was improved by the optimized sample preparation method using 3‐AQ/CHCA compared with the conventional method using 2,5‐DHB. The validation of 3‐AQ/CHCA for phosphopeptides was systematically confirmed, expanding the potential of this matrix to phosphoproteomics. Copyright © 2012 John Wiley & Sons, Ltd.
Direct mass spectrometric screening of antibiotics from bacterial surfaces using liquid extraction surface analysis
Authors: Kai Marco , González Ignacio , Genilloud Olga , Singh Sheo B. , Svatoš Aleš 
Published: September 2012

RATIONALEThere is a need to find new antibiotic agents to fight resistant pathogenic bacteria. To search successfully for novel antibiotics from bacteria cultivated under diverse conditions, we need a fast and cost‐effective screening method.METHODSA combination of Liquid Extraction Surface Analysis (LESA), automated chip‐based nanoelectrospray ionization, and high‐resolution mass or tandem mass spectrometry using an Orbitrap XL was tested as the screening platform. Actinobacteria, known to produce well‐recognized thiazolyl peptide antibiotics, were cultivated on a plate of solid medium and the antibiotics were extracted by organic solvent mixtures from the surface of colonies grown on the plate and analyzed using mass spectrometry (MS).RESULTSLESA combined with high‐resolution MS is a powerful tool with which to extract and detect thiazolyl peptide antibiotics from different Actinobacteria. Known antibiotics were correctly detected with high mass accuracy (<4 ppm) and structurally characterized using tandem mass spectra. Our method is the first step toward the development of a novel high‐throughput extraction and identification tool for antibiotics in particular and natural products in general.CONCLUSIONSThe method described in this paper is suitable for (1) screening the natural products produced by bacterial colonies on cultivation plates within the first 2 min following extraction and (2) detecting antibiotics at high mass accuracy; the cost is around 2 Euro per sample. Copyright © 2012 John Wiley & Sons, Ltd.
Mapping and correction of the CMM workspace error with the use of an electronic gyroscope and neural networks—practical application
Authors: Swornowski Pawel J. 
Published: September 2012

SummaryThe article presents the application of neural networks in determining and correction of the deformation of a coordinate measuring machine (CMM) workspace. The information about the CMM errors is acquired using an ADXRS401 electronic gyroscope. A test device (PS‐20 module) was built and integrated with a commercial measurement system based on the SP25M passive scanning probe and with a PH10M module (Renishaw). The proposed solution was tested on a Kemco 600 CMM and on a DEA Global Clima CMM. In the former case, correction of the CMM errors was performed using the source code of WinIOS software owned by The Institute of Advanced Manufacturing Technology, Cracow, Poland and in the latter on an external PC. Optimum parameters of full and simplified mapping of a given layer of the CMM workspace were determined for practical applications. The proposed method can be employed for the interim check (ISO 10360–2 procedure) or to detect local CMM deformations, occurring when the CMM works at high scanning speeds (>20 mm/s). SCANNING 35: 222‐231, 2013. © 2012 Wiley Periodicals, Inc.
Effect of Long‐Chain Length on the Surface Activities of Zwitterionic Imidazolium‐Based Surfactants: 1‐Carboxymethyl‐3‐alkylimidazolium Inner Salts
Authors: Ni Bang‐qing , Hu Jie , Liu Xue‐feng , Chen Hui , Fang Yun 
Published: September 2012

AbstractZwitterionic imidazolium‐based surfactants, namely 1‐carboxymethyl‐3‐alkyl imidazolium inner salts (CnimCM, n = 10, 12, and 14), were synthesized. Their molecule structures were characterized by means of electrospray ionization mass spectrometry (ESI–MS), 1H nuclear magnetic resonance (1H NMR) and elemental analysis. Compared to the structurally related N‐alkylbetaines (CnH2n+1N+(CH3)2CH2COO−), the CMCs of CnimCM are smaller than those of N‐alkylbetaines. The effect of the long‐chain length on the typical physicochemical properties of CnimCM was studied. It is found that the lengthening of the long‐chain enhances the surface activity of CnimCM. The tendency for CnimCM surfactants is similar to the case of the structurally related traditional zwitterionic N‐alkylbetaines.
The effect of serotonin transporter gene promoter polymorphism on adolescent and adult ADHD symptoms and educational attainment: A longitudinal study
Authors: Kiive E. , Harro J. 
Published: September 2012

AbstractIntroduction:The purpose of this longitudinal study was to investigate the relationship between the 5-HTTLPR genotype, symptoms of ADHD in adolescence and adulthood, and educational attainment in a population representative sample. Neuroticism, depressive symptoms and general mental abilities were controlled for as possible confounding factors.Methods:ADHD symptoms were reported at age 15 and 18 by teachers using the Hyperactivity Scale of af Klinteberg and SNAP-IV, and self-reported at age 25 using the ASRS. Data about education were reported at age 25.Results:At age 15, subjects with the l/l genotype had more concentration difficulties compared to s-allele carriers, and they also had more inattention symptoms according to SNAP-IV at age 18. These results were not altered by taking neuroticism or depressive symptoms into account. No 5-HTTLPR genotype effect on self-reported ADHD symptoms at age 25 was found. Inattention symptoms in adolescence were associated with lower education in young adulthood. The proportion of subjects with higher education at age 25 was significantly larger among s/s genotype compared to the l/l or s/l genotype.Conclusions:The l/l genotype of the 5-HTTLPR is associated with inattentive symptoms during adolescence in the general population, and increases the likelihood of inferior educational level in young adulthood.
A comparison of surgical outcomes between laparoscopic and open myomectomy in Southern Taiwan
Authors: Chang Chi‐Chang , Chen Wency 
Published: September 2012

AbstractObjectiveTo compare operative data and operative and clinical outcomes of laparoscopic myomectomy (LM) with those of open myomectomy (OM).MethodsIn a retrospective study, the records of 81 women who underwent LM and 74 women who underwent at E‐DA Hospital, Yan‐Chau Shiang, Taiwan, from June 2004 to October 2007 were reviewed. Patient demographic, intraoperative, and postoperative data were compared between the 2 surgical groups.ResultsThe mean ± SD age of patients in the OM and LM groups was 40.08 ± 6.49 years and 41.14 ± 6.46 years, respectively. Median (range) surgical time and blood loss were both significantly less in the LM group than in the OM group (100 min [73–120 min] versus 120 min [90–146 min], and 100 mL [100–200 mL] versus 150 mL [100–305 mL], respectively). Thirteen patients in the OM group required a blood transfusion, compared with 1 in the LM group. There was no difference in complications or recurrences between the 2 groups.ConclusionCompared with OM, LM was found to be associated with shorter surgical time and less blood loss, but there was no difference in the rate of complications or recurrence between the 2 groups.
Simulations of a double-diffusive interface in the diffusive convection regime
Authors: Carpenter J. R. , Sommer T. , Wüest A. 
Published: September 2012

AbstractThree-dimensional direct numerical simulations are performed that give us an in-depth account of the evolution and structure of the double-diffusive interface. We examine the diffusive convection regime, which, in the oceanographically relevant case, consists of relatively cold fresh water above warm salty water. A ‘double-boundary-layer’ structure is found in all of the simulations, in which the temperature ($T$) interface has a greater thickness than the salinity ($S$) interface. Therefore, thin gravitationally unstable boundary layers are maintained at the edges of the diffusive interface. The$TS$-interface thickness ratio is found to scale with the diffusivity ratio in a consistent manner once the shear across the boundary layers is accounted for. The turbulence present in the mixed layers is not able to penetrate the stable stratification of the interface core, and the$TS$-fluxes through the core are given by their molecular diffusion values. Interface growth in time is found to be determined by molecular diffusion of the$S$-interface, in agreement with a previous theory. The stability of the boundary layers is also considered, where we find boundary layer Rayleigh numbers that are an order of magnitude lower than previously assumed.
‘HAVING A ROAD’: SOCIAL AND SPATIAL MOBILITY OF PERSONS OF SLAVE AND MIXED DESCENT IN POST-INDEPENDENCE CENTRAL MALI
Authors: PELCKMANS LOTTE 
Published: September 2012

ABSTRACTThis article examines the migration trajectories of individuals of slave descent and ‘mixed descent’ (children of slave concubines) in a royal family network from the Haayre region of central Mali. Focusing on the twentieth century, it considers the extent to which social status has defined options for mobility within this network. Its argument is twofold. First, it shows that attention should be paid not only to the slave/free divide but also to subtler hierarchical nuances such as mixed descent and royal slavery. Rather than social statusper se, it is internal hierarchies within social status groups which defined a person's options for movement. Second, the mobile trajectories of people with royal slave status tended to be intertwined with and depend on the movements of their patrons. Although these dependent forms of migration hardly ever changed their social status, they improved their economic condition considerably.