bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural Design of Ionic Conduction Paths in Molecular Crystals for Selective and Enhanced Lithium Ion Conduction
Authors: Moriya Makoto , Kato Daiki , Sakamoto Wataru , Yogo Toshinobu 
Published: August 2013

AbstractThe molecular crystals [Li{N(SO2CF3)2}{C6H4(OCH3)2}2] and [Li{N(SO2CF3)2}{C6F2H2(OCH3)2}2] with solid‐state lithium ion conductivity have been synthesized by the addition of two equivalents of 1,2‐dimethoxybenzene or 1,2‐difluoro‐4,5‐dimethoxybenzene to Li{N(SO2CF3)2}, respectively. Single‐crystal X‐ray diffraction analysis revealed the formation of ionic conduction paths with an ordered arrangement of lithium ions in these crystal structures, afforded by the self‐ assembled stacking of molecular‐based channels consisting of N(SO2CF3)2 anion and 1,2‐dimethoxybenzene frameworks as a result of intermolecular aromatic and hydrogen interactions. These compounds show selective lithium ion conductivity as the anions behave as a component unit of the conduction paths. The relationship between the crystal structure and ionic conductivity of the molecular crystals provides a clue to the development of novel solid electrolytes based on molecular crystals showing fast and selective lithium ion conduction.
Synthesis of Poly(benzothiadiazole‐co‐dithienobenzodithiophenes) and Effect of Thiophene Insertion for High‐Performance Polymer Solar Cells
Authors: Yun Hui‐Jun , Lee Yun‐Ji , Yoo Seung‐Jin , Chung Dae Sung , Kim Yun‐Hi , Kwon Soon‐Ki 
Published: August 2013

AbstractWe describe herein the synthesis of novel donor–acceptor conjugated polymers with dithienobenzodithiophenes (DTBDT) as the electron donor and 2,1,3‐benzothiadiazole as the electron acceptor for high‐performance organic photovoltaics (OPVs). We studied the effects of strategically inserting thiophene into the DTBDT as a substituent on the skeletal structure on the opto‐electronic performances of fabricated devices. From UV/Vis absorption, electrochemical, and field‐effect transistor analyses, we found that the thiophene‐containing DTBDT derivative can substantially increase the orbital overlap area between adjacent conjugated chains and thus dramatically enhance charge‐carrier mobility up to 0.55 cm2 V−1 s−1. The outstanding charge‐transport characteristics of this polymer allowed the realization of high‐performance organic solar cells with a power conversion efficiency (PCE) of 5.1 %. Detailed studies on the morphological factors that enable the maximum PCE of the polymer solar cells are discussed along with a hole/electron mobility analysis based on the space‐charge‐limited current model.
Tunable Emissive Lanthanidomesogen Derived from a Room‐Temperature Liquid‐Crystalline Schiff‐Base Ligand
Authors: Pramanik Harun A. R. , Das Gobinda , Bhattacharjee Chira R. , Paul Pradip C. , Mondal Paritosh , Prasad S. Krishna , Rao D. S. Shankar 
Published: August 2013

AbstractA novel photoluminescent room‐temperature liquid‐crystalline salicylaldimine Schiff base with a short alkoxy substituent and a series of lanthanide(III) complexes of the type [Ln(LH)3(NO3)3] (Ln=La, Pr, Sm, Gd, Tb, Dy; LH=(E)‐5‐(hexyloxy)‐2‐ [{2‐(2‐hydroxyethylamino)ethylimino]methyl}phenol) have been synthesized and characterized by FTIR, 1H and 13C NMR, UV/Vis, and FAB‐MS analyses. The ligand coordinates to the metal ions in its zwitterionic form. The thermal behavior of the compounds was investigated by polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). The ligand exhibits an enantiotropic hexagonal columnar (Colh) mesophase at room temperature and the complexes show an enantiotropic lamellar columnar (ColL) phase at around 120 °C with high thermal stability. Based on XRD results, different space‐filling models have been proposed for the ligand and complexes to account for the columnar mesomorphism. The ligand exhibits intense blue emission both in solution and in the condensed state. The most intense emissions were observed for the samarium and terbium complexes, with the samarium complex glowing with a bright‐orange light (ca. 560–644 nm) and the terbium complex emitting green light (ca. 490–622 nm) upon UV irradiation. DFT calculations performed by using the DMol3 program at the BLYP/DNP level of theory revealed a nine‐coordinate structure for the lanthanide complexes.
Total Synthesis of Enantiopure Pyrrhoxanthin: Alternative Methods for the Stereoselective Preparation of 4‐Alkylidenebutenolides
Authors: Vaz Belén , Otero Leticia , Álvarez Rosana , de Lera Ángel R. 
Published: August 2013

AbstractA new stereocontrolled total synthesis of the configurationally labile C37‐norcarotenoid pyrrhoxanthin in enantiopure form has been completed. A highly stereoselective Horner–Wadsworth–Emmons (HWE) condensation of a C17‐allylphosphonate and a C20‐aldehyde was used as the last conjunctive step. Both a Sonogashira reaction to form the C17‐phosphonate and the final HWE condensation proved to be compatible with the sensitive C7–C10 enyne E configuration. Regioselective (5‐exo‐dig) silver‐promoted lactonization reactions of three alternative pent‐2‐en‐4‐ynoic acid precursors with increased complexity, including a fully functionalized C20‐fragment, were explored for the preparation of the γ‐alkylidenebutenolide fragment. This survey extends the existing methodologies for the preparation of oxygen‐containing carotenoids (xanthophylls) and streamlines the synthesis of additional members of the C37‐norcarotenoid butenolide family of natural products.
Unusual Inherent Electrochemistry of Graphene Oxides Prepared Using Permanganate Oxidants
Authors: Eng Alex Yong Sheng , Ambrosi Adriano , Chua Chun Kiang , Šaněk Filip , Sofer Zdeněk , Pumera Martin 
Published: August 2013

AbstractGraphene and graphene oxides are materials of significant interest in electrochemical devices such as supercapacitors, batteries, fuel cells, and sensors. Graphene oxides and reduced graphenes are typically prepared by oxidizing graphite in strong mineral acid mixtures with chlorate (Staudenmaier, Hofmann) or permanganate (Hummers, Tour) oxidants. Herein, we reveal that graphene oxides pose inherent electrochemistry, that is, they can be oxidized or reduced at relatively mild potentials (within the range ±1 V) that are lower than typical battery potentials. This inherent electrochemistry of graphene differs dramatically from that of the used oxidants. Graphene oxides prepared using chlorate exhibit chemically irreversible reductions, whereas graphene oxides prepared through permanganate‐based methods exhibit very unusual inherent chemically reversible electrochemistry of oxygen‐containing groups. Insight into the electrochemical behaviour was obtained through cyclic voltammetry, chronoamperometry, and X‐ray photoelectron spectroscopy experiments. Our findings are of extreme importance for the electrochemistry community as they reveal that electrode materials undergo cyclic changes in charge/discharge cycles, which has strong implications for energy‐storage and sensing devices.
Forest Leaf Area Index (LAI) Estimation Using Airborne Discrete‐Return Lidar Data
Authors: She‐Zhou LUO , Cheng WANG , Gui‐Bin ZHANG , Xiao‐Huan XI , Gui‐Cai LI 
Published: August 2013

AbstractThe Leaf Area Index (LAI) is one of the most important parameters, which controls biological and physical processes associated with vegetation on the Earth's surface, such as photosynthesis, respiration, transpiration, carbon and nutrient cycles, and rainfall interception. Therefore, rapid, reliable and objective estimations of LAI are essential. In this study, we used a simplified approach to compute laser penetration index (LPI) from airborne discrete‐return LiDAR data, and LPI was computed based on corrected echo intensity for the first time. Using the variable of LPI, we built an LAI estimation model based on Beer‐Lambert law. This approach was applied to a forest area in Dayakou, Gansu Province of China. The accuracy of the corrected intensity‐derived LAI estimation model was compared with that of uncorrected intensity‐derived and echo counts‐derived model. The results show that the corrected echoes intensity can improve the accuracy of LAI estimation. To assess validity and generalization of the model, we validated the optimum model using the Leave‐One‐Out Cross‐Validation (LOOCV) procedure, and show that the model has no overfitting and is more general. Finally, we examined the accuracy of predicted LAIs with 16 field‐measured LAIs which were not involved in the modeling process and indicated that LAI can be estimated with a high accuracy in mountains area by corrected echo intensity. The comparison indicates the LiDAR‐derived LAI (R2=0.825, RMSE=0.165) is much higher than that of the LAI from Landsat TM images (R2=0.605, RMSE=0.257). It means that airborne LiDAR data can be used to obtain high‐accuracy LAI estimation and provide reliable data for ecological environment research.
Characteristics of Deep Crust Structure Beneath Western Yunnan
Authors: En‐Hui ZHANG , Hai LOU , Shi‐Xu JIA , Yong‐Hua LI 
Published: August 2013

AbstractOne two‐dimensional P wave velocity model of the crust and uppermost mantle was established based on the integrative interpretation of travel‐time data and amplitude information from the deep seismic sounding on the Pu'er‐Luxi profile, western Yunnan. Our results show strong lateral variations in crustal thickness along the profile, which is about 35 km in the southwest and 43 km in the northeast Yunnan. Average crustal P velocities are low with respect to the global average, varying from 5.9 to 6.13 km/s. Combined with previous joint inversion results of receiver functions and surface waves, the average crustal Poisson's ratio (σ) is calculated, 0.23 in the southwest part of the profile and 0.25 in the northeast part of the profile beneath the western Yunnan. The low P wave velocity and σ values for the upper crust layer beneath the southwest part of the profile is indicative of felsic rocks rich in quartz in the α state, while the relative high P wave velocity and σ for the upper crust layer under the northeast part of the profile is indicative of rocks of granitic and granodioritic composition. The P wave velocity and σ for the lower crust layer is 6.25∼6.75 km/s and 0.24∼0.26 km/s beneath the profile, which can be explained by felsic gneisses in the upper part of the lower crust transitioning to amphibolite in the lower part. Our crustal velocity model shows remarkable contrasts across the Red River fault and the velocity difference becomes gentler with increasing depth. The crustal thickness across the Red River fault is also significantly different. The variation of the velocity and crustal thickness across the Xiaojiang fault is not so remarkable.
Evaluation of a new 1H/31P dual‐tuned birdcage coil for 31P spectroscopy
Authors: Potter W.M. , Wang L. , McCully K.K. , Zhao Q. 
Published: August 2013

ABSTRACTWe introduce a new dual‐tuned hydrogen/phosphorus (1H/31P) birdcage coil, referred to as split birdcage coil, and evaluate its performance using both simulations and magnetic resonance (MR) experiments on a 3 T MR scanner. The proposed coil simplifies the practical matters of tuning and matching, which makes the coil easily reproducible. Simulations were run with the finite difference in time domain method to evaluate the sensitivity and homogeneity of the magnetic field generated by the proposed 1H coils. Following simulations, MR experiments were conducted using both a phantom and human thigh to compare the proposed design with a currently available commercial dual‐tuned flexible surface coil, referred to as flex surface coil, for signal to noise ratio (SNR) as well as homogeneity for the 31P coil. At regions deep within the human thigh, the split birdcage coil was able to acquire spectroscopic signal with a higher average SNR than the flex surface coil. For all regions except those close to the flex surface coil, the split birdcage coil matched or exceeded the performance of the flex surface coil. © 2013 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 43B: 90‐99, 2013
Design and implementation of an FPGA‐based timing pulse programmer for pulsed‐electron paramagnetic resonance applications
Authors: Sun Li , Savory Joshua J. , Warncke Kurt 
Published: August 2013

ABSTRACTThe design, construction, and implementation of a field‐programmable gate array (FPGA)‐based pulse programmer for pulsed‐electron paramagnetic resonance experiments is described. The FPGA pulse programmer offers advantages in design flexibility and cost over previous pulse programmers, which are based on commercial digital delay generators, logic pattern generators, and application‐specific integrated circuit designs. The FPGA pulse progammer features a novel transition‐based algorithm and command protocol, which is optimized for the timing structure required for most pulsed magnetic resonance experiments. The algorithm was implemented by using a Spartan‐6 FPGA (Xilinx), which provides an easily accessible and cost effective solution for FPGA interfacing. An auxiliary board was designed for the FPGA‐instrument interface, which buffers the FPGA outputs for increased power consumption and capacitive load requirements. Device specifications include: Nanosecond pulse formation (transition edge rise/fall times, ≤3 ns), low jitter (≤150 ps), large number of channels (16 implemented; 48 available), and long pulse duration (no limit). The hardware and software for the device were designed for facile reconfiguration to match user experimental requirements and constraints. Operation of the device is demonstrated and benchmarked by applications to one‐dimensional electron spin echo envelope modulation and two‐dimensional hyperfine sublevel correlation (HYSCORE) experiments. The FPGA approach is transferrable to applications in nuclear magnetic resonance (magnetic resonance imaging), and to pulse perturbation and detection bandwidths in spectroscopies up through the optical range. © 2013 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 43B: 100‐109, 2013
Fine‐needle aspirations of pancreatic serous cystadenomas: Improving diagnostic yield with cell blocks and α‐inhibin immunohistochemistry
Authors: Salomao Marcela , Remotti Helen , Allendorf John D. , Poneros John M. , Sethi Amrita , Gonda Tamas A. , Saqi Anjali 
Published: August 2013

BACKGROUNDThe diagnosis of serous cystadenoma (SCA), a rare benign pancreatic neoplasm, can alter the management of patients with pancreatic masses. Although characteristic imaging findings and fluid chemical analysis have been described, SCAs are not always recognized preoperatively. Furthermore, scant cellular yield on fine‐needle aspiration (FNA) often leads to a nondiagnostic or nonspecific benign diagnosis. α‐Inhibin (AI), a sensitive marker for SCA, is infrequently required for diagnosis in surgical specimens due to their characteristic histologic appearance. The objective of the current study was to determine whether AI staining can improve SCA diagnosis on FNA specimens.METHODSFifteen confirmed cases of SCA with prior FNA specimens were selected for this study. FNAs were evaluated for cellularity, cellular arrangement, and cytomorphology. Resection specimens were reviewed.RESULTSOf the 15 FNA cases, approximately 75% demonstrated scant cellularity (11 of 15 cases). On smears, the cells were arranged as flat sheets, corresponding to strips of cells on cell block sections. The cells were small and round to cuboidal, with clear cytoplasm; occasional plasmacytoid cells and oncocytic cells were identified. Flattened cells, corresponding to attenuated epithelial cells lining macrocysts on the resections, were also noted. Stromal fragments were present in 5 FNAs and correlated with the hyalinized stroma in the resection specimens. AI immunostaining was positive in 88% of cases (7 of 8 of cases), thereby supporting the diagnosis of SCA.CONCLUSIONSThe results of the current study indicate that low cellularity and bland cytology are inherent to SCAs. Performing cell blocks and AI staining on FNA specimens is useful for establishing the diagnosis of SCA. An immunohistochemical panel including AI, chromogranin, and synaptophysin may enhance the diagnostic accuracy of pancreatic FNA specimens. Cancer (Cancer Cytopathol) 2014;122:33–39. © 2013 American Cancer Society.
Patterns of cortical input to the primary motor area in the marmoset monkey
Authors: Burman Kathleen J. , Bakola Sophia , Richardson Karyn E. , Reser David H. , Rosa Marcello G.P. 
Published: August 2013

ABSTRACTIn primates the primary motor cortex (M1) forms a topographic map of the body, whereby neurons in the medial part of this area control movements involving trunk and hindlimb muscles, those in the intermediate part control movements involving forelimb muscles, and those in the lateral part control movements of facial and other head muscles. This topography is accompanied by changes in cytoarchitectural characteristics, raising the question of whether the anatomical connections also vary between different parts of M1. To address this issue, we compared the patterns of cortical afferents revealed by retrograde tracer injections in different locations within M1 of marmoset monkeys. We found that the entire extent of this area is unified by projections from the dorsocaudal and medial subdivisions of premotor cortex (areas 6DC and 6M), from somatosensory areas 3a, 3b, 1/2, and S2, and from posterior parietal area PE. While cingulate areas projected to all subdivisions, they preferentially targeted the medial part of M1. Conversely, the ventral premotor areas were preferentially connected with the lateral part of M1. Smaller but consistent inputs originated in frontal area 6DR, ventral posterior parietal cortex, the retroinsular cortex, and area TPt. Connections with intraparietal, prefrontal, and temporal areas were very sparse, and variable. Our results demonstrate that M1 is unified by a consistent pattern of major connections, but also shows regional variations in terms of minor inputs. These differences likely reflect requirements for control of voluntary movement involving different body parts. J. Comp. Neurol. 522:811–843, 2014. © 2013 Wiley Periodicals, Inc.
Rax regulates hypothalamic tanycyte differentiation and barrier function in mice
Authors: Miranda‐Angulo Ana L. , Byerly Mardi S. , Mesa Janny , Wang Hong , Blackshaw Seth 
Published: August 2013

ABSTRACTThe wall of the ventral third ventricle is composed of two distinct cell populations: tanycytes and ependymal cells. Tanycytes regulate many aspects of hypothalamic physiology, but little is known about the transcriptional network that regulates their development and function. We observed that the retina and anterior neural fold homeobox transcription factor (Rax) is selectively expressed in hypothalamic tanycytes, and showed a complementary pattern of expression to markers of hypothalamic ependymal cells, such as Rarres2 (retinoic acid receptor responder [tazarotene induced] 2). To determine whether Rax controls tanycyte differentiation and function, we generated Rax haploinsufficient mice and examined their cellular and molecular phenotype in adulthood. These mice appeared grossly normal, but careful examination revealed a thinning of the third ventricular wall and reduction of both tanycyte and ependymal markers. These experiments show that Rax is required for hypothalamic tanycyte and ependymal cell differentiation. Rax haploinsufficiency also resulted in the ectopic presence of ependymal cells in the α2 tanycytic zone, where few ependymal cells are normally found, suggesting that Rax is selectively required for α2 tanycyte differentiation. These changes in the ventricular wall were associated with reduced diffusion of Evans Blue tracer from the ventricle to the hypothalamic parenchyma, with no apparent repercussion on the gross anatomical or behavioral phenotype of these mice. In conclusion, we have provided evidence that Rax is required for the normal differentiation and patterning of hypothalamic tanycytes and ependymal cells, as well as for maintenance of the cerebrospinal fluid–hypothalamus barrier. J. Comp. Neurol. 522:876–899, 2014. © 2013 The Authors. The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.
Torsional Dynamics of Thioflavin T in Room‐Temperature Ionic Liquids: An Effect of Heterogeneity of the Medium
Authors: Chatterjee Aninda , Maity Banibrata , Seth Debabrata 
Published: August 2013

AbstractThe ultrafast excited‐state dynamics of a fibril binding dye, thioflavin T (ThT), has been studied in two room‐temperature ionic liquids (RTILs): 1‐Butyl‐1‐methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and methyltrioctylammonium bis(trifluoromethylsulfonyl)imide. Previously, in most studies, it was observed that the excited‐state dynamics of the ThT dye were dependent on the viscosity of the medium. In our study, by using RTILs, we have demonstrated that the excited‐state dynamics of ThT are not only viscosity dependent, but also dependent on the heterogeneous nature of the medium. The effect of structural heterogeneity present in neat RTILs on the excited‐state dynamics of ThT was observed. For both RTILs, excitation wavelength dependency on the emission properties of ThT was observed.
Comprehensive and Accurate Ab Initio Energy Surface of Simple Alanine Peptides
Authors: Lanza Giuseppe , Chiacchio Maria A. 
Published: August 2013

AbstractSecondary structures for AcAlanNH2 (n=2–4) peptides have been analyzed by means of ab initio MP2, CCSD(T), and DFT‐B3PW91 methods using large basis sets and including implicit hydration effects and thermal corrections. In addition to the classical “pure” right‐handed 310‐ and α‐helices, left‐handed polyproline II, inverse γ‐turn, and fully extended conformations, a large number of “mixed” structures obtained by combining characteristic φ/ψ angles of each residue in every way have been found. All mixed structures are energetically accessible and can be present at significant levels in aqueous solution. Furthermore, they represent the way through which hierarchical unfolding of 310‐ and α‐helices or nonhierarchical polyproline II to fully extended transitions occur. Computational results are in qualitative agreement with the large amount of experimental data for simpler polyalanines and provide significant insight into their thermodynamic properties and how these can be modulated by interactions with solvent.