bluuebunny/crossref_metadata_2025 huggingface dataset:
Resonance effects of Wannier–Frenkel excitons in luminescence properties of layered perovskite compounds (C6H5CH2NH3)2PbClxBr4−
x
Authors: Nagao Katsuhiko , Kawano Naoki , Koshimizu Masanori , Asai Keisuke
Published: January 2014

To analyze the luminescence properties under resonance between inorganic–organic layers, (C6H5CH2NH3)2PbCl
x
Br4−

x
thin films was fabricated. The Wannier exciton level in inorganic layer has been tuned to triplet excited levels in benzylamine in layered perovskite-type compounds by changing the halogen composition in the inorganic layer. When the Wannier exciton level was higher than the triplet state of benzylamine, energy transfer from the former to the latter occurred. The phosphorescence peak at 3.59 eV was sharpened and enhanced in the films with x = 3.75 and 3.80, and this effect can be ascribed to the enhancement of an electronic transition due to the resonance between the organic and inorganic layers.
Super-resolution phase reconstruction technique in electron holography with a stage-scanning system
Authors: Lei Dan , Mitsuishi Kazutaka , Harada Ken , Shimojo Masayuki , Ju Dongying , Takeguchi Masaki
Published: January 2014

Super-resolution image reconstruction is a digital signal processing technique that allows creating a high-resolution image from multiple low-resolution images taken at slightly different positions. We introduce the super-resolution image reconstruction technique into electron holography for reconstructing phase images as follows: the studied specimen is shifted step-wise with a high-precision piezo holder, and a series of holograms is recorded. When the step size is not a multiple of the CCD pixel size, processing of the acquired series results in a higher pixel density and spatial resolution as compared to the phase image obtained with conventional holography. The final resolution exceeds the limit of the CCD pixel size divided by the magnification.
Density functional studies of surface potentials for hydrogen and oxygen atoms on diamond (111) surfaces
Authors: Moustafa Samar , Tokuda Norio , Inokuma Takao
Published: January 2014

The adsorption of hydrogen and oxygen atoms on diamond (111)-(1 × 1) surfaces is investigated by a molecular orbital method based on the density functional theory. The potential energy for hydrogen and oxygen adatoms on a flat surface and a surface with monoatomic steps are studied. The oxygen adatom is found to have a much lower energy barrier for migration than the hydrogen adatom. On the basis of the variations of potential energy, surface diffusion coefficients of adatoms are calculated. The potential energy for the oxygen adatom is much lowered near the step edge in comparison with those on flat regions. It is suggested that the oxygen atoms adsorbed on the diamond (111) surface are preferentially trapped near atomic steps after migration.
Density functional theory study on the interaction of magnesium ions with graphene surface
Authors: Kato Koichi , Iyama Tetsuji , Tachikawa Hiroto
Published: January 2014

The interactions of magnesium species (Mg, Mg+, and Mg2+) with a graphene surface have been investigated by the density functional theory (DFT) method. The distances of Mg atoms from the graphene surface were calculated to be 1.80 Å (Mg2+), 2.16 Å (Mg+), and 4.17 Å (Mg) at the Coulomb-attenuating method (CAM)-B3LYP/6-31G(d) level. The binding nature of Mg ions (Mg2+ and Mg+) is caused by the charge transfer interaction, and the Mg atom interacts with the surface via van der Waals (vdW) force. The Mg ions can diffuse via the C–C bond center between hexagonal sites. The barrier heights for the diffusion of Mg2+ and Mg+ on the graphene surface were calculated to be 14.6 and 2.8 kcal/mol, respectively. On the other hand, the diffusion of Mg atoms proceeds with a very low barrier. The mechanism of the interaction of Mg with the graphene surface was discussed on the basis of theoretical results.
Transformation of multiwalled carbon nanotubes to amorphous carbon nanorods under ion irradiation
Authors: Honda Shin-ichi , Tamura Ryosuke , Nosho Yusuke , Tsukagoshi Akira , Niibe Masahito , Terasawa Mititaka , Hirase Ryuji , Izumi Hirokazu , Yoshioka Hideki , Niwase Keisuke , Taguchi Eiji , Lee Kuei-Yi , Oura Masaki
Published: January 2014

Amorphous carbon nanorods were synthesized from hollow multiwalled carbon nanotubes (MWCNTs) by low-energy Ar ion irradiation at room temperature. The obtained nanorods were investigated by Raman spectroscopy, transmission electron microscopy (TEM), soft X-ray photoelectron spectroscopy (XPS), and soft X-ray absorption spectroscopy (XAS). It was found that the diameter of the MWCNTs significantly increased with increasing the fluence. Finally, the original hollow structure and the graphite (002) TEM diffraction spots of MWCNTs completely disappeared and a broadening of Raman spectra occurred, indicating the amorphization of MWCNTs. The increase in the diameter by the irradiation can be explained by the bending and the randomization of the broken carbon hexagonal networks, and the accumulation of knocked-on atoms. The XPS and XAS measurements also support the formation of amorphous carbon nanorods.
Synthesis and diameter control of vertically-aligned carbon nanotube growth from Langmuir–Blodgett films deposited Fe3O4@SiO2 core–shell nanoparticles
Authors: Ohashi Masaaki , Sugawara Takehiro , Kawasaki Kohei , Kushida Masahito
Published: January 2014

We synthesized Fe3O4 nanoparticles (NPs) and Fe3O4@SiO2 core–shell NPs. Vertically-aligned carbon nanotubes (VA-CNTs) were grown from Fe3O4 NP monolayer and Fe3O4@SiO2 core–shell NP monolayer, respectively, by thermal chemical vapor deposition (CVD). The monolayer was prepared on SiO2/Si substrate by Langmuir–Blodgett (LB) technique. Fe3O4 NP monolayer was used as catalyst for CNT growth, and core–shell NP monolayer was used as catalyst for CNT growth, too. We found that Fe3O4 NP covered with SiO2 shell was moved from the center to the surface of core–shell NP during pre-thermal process at thermal CVD. The CNT carpet height tended to increase with the increasing thermal annealing time and decreasing shell thickness. And the average diameter of CNTs grown from core–shell LB film was smaller than that of CNTs grown from Fe3O4 LB film, and average diameter of CNTs almost conformed to Fe3O4 core size with SiO2 shell.
Structural modification of single-walled carbon nanotube induced by X-ray irradiation and subsequent annealing studied by Raman scattering spectroscopy in radial breathing mode
Authors: Murakami Toshiya , Yamamoto Yuki , Matsuda Mitsuaki , Kisoda Kenji , Itoh Chihiro
Published: January 2014

The formation of X-ray-induced defects changes the spectral shape of the radial breathing mode (RBM) and defect-induced mode (D band) in the Raman spectra of single-walled carbon nanotubes (SWNTs). X-ray-induced defects have been found to be annealed by thermal treatment, indicating that they are Frenkel pairs (vacancy and interstitial pairs). We found that the spectral shape of RBM is not entirely recovered after post-irradiation annealing. The temperatures for the complete annealing of X-ray-induced defects were within the range of 200–600 °C depending on the tube geometry. From these results, we suggest that the stability of X-ray-induced defects depends on the tube geometry and that the combination of X-ray irradiation and post-irradiation annealing causes a chirality change in SWNTs.
Three-dimensional structural control and analysis of hexagonal boron nitride nanosheets assembly in nanocomposite films induced by electric field concentration
Authors: Fujihara Takeshi , Cho Hong-Baek , Kanno Masanao , Nakayama Tadachika , Suzuki Tsuneo , Jiang Weihua , Suematsu Hisayuki , Niihara Koichi
Published: January 2014

Fabrication and controlled localization of BN nanosheets assemblies were performed in polymer-based nanocomposite films under application of DC electric field switching. The localization of BN nanosheets with linearly assembled structure were modulated by applying a Si-mold electrode with micro-dimensional protrusions on the surface during electric field inducement. The established assembly of BN nanosheets, incorporated in the composite was analyzed three-dimensionally using X-ray computed tomography. The structural variation of linear assembles of BN nanosheets (LABNs) were modulated from filament-like to bridge-like structure by applying switching DC electric field whose effect was further intensified induced by electric field concentration. The nanocomposite films with localized LABNs can be potentially applied for efficient heat dissipation from local heat source, such as modern electronic, optoelectronic, photonic devices, and systems in semiconductor industry.
Cavity polaritons in one-dimensional photonic crystals containing dye molecule–titanate nanosheet hybrids
Authors: Ishii Kenta , Suzuki Makoto , Chen Changdong , Feng Qi , Nakanishi Shunsuke , Tsurumachi Noriaki
Published: January 2014

We investigated the optical properties of one dimensional photonic crystal (1D-PC) microcavity with a wedge-shaped cavity layer containing fluorescent pseudoisocyanine (PIC)-gelatin and nonfluorescent PIC–H1.07Ti1.73O4∙nH2O (HTO) nanohybrids. In the case of the PIC-gelatin, the formation of cavity polaritons with a Rabi splitting energy of 49.2 meV was clearly observed. Contrary to our expectations, the formation of cavity polaritons in the case of the PIC–HTO nanohybrids was also observed, even though their splitting energy of 5.8 meV was small. Although different possible explanations were considered, at present, there is insufficient information to completely explain the phenomena. The formation of cavity polaritons with nonfluorescent excitons is indeed very rare and therefore interesting.
Eco-friendly step-and-flash imprint lithography using ultraviolet-curing liquid material with lactulose derivative derived from medicinal drugs for biomicrochips
Authors: Takei Satoshi
Published: January 2014

Eco-friendly step-and-flash imprint lithography was investigated for the future high-volume manufacture of biomicrochips. A nanoimprinted ultraviolet-curing liquid material with a lactulose derivative derived from medicinal drugs was found to have excellent UV curing properties, film shrinkage during a UV curing reaction, and good etch selectivity with a silicon-based middle layer in CF4 plasma treatment. 80 nm half-pitch lines of the nanoimprinted ultraviolet-curing liquid material with a lactulose derivative were resolved using the process conditions for a trilayer including a silicon-based middle layer with a high silicon concentration of 21.5 wt % and a novolac-based bottom layer on a 100 mm silicon wafer in step-and-flash imprint lithography.
Effect of contact resistance on mobility determination by impedance spectroscopy
Authors: Takata Masashi , Kouda Naoya , Ishihara Shingo , Nagase Takashi , Kobayashi Takashi , Naito Hiroyoshi
Published: January 2014

The effect of contact resistance on the determination of charge carrier mobility in single-injection space-charge-limited (SCL) diodes is numerically examined. Contact resistance is inevitably involved in the equivalent circuit of the SCL diodes. It is found that the mobility is accurately determined when it is less than or equal to 1.0 × 10−5 cm2 V−1 s−1 even in the presence of contact resistance at a semiconducting layer thickness of 100 nm, which is comparable to the active layer thickness of organic electronic devices, such as organic light-emitting diodes and organic photovoltaic devices. In contrast, when the input mobility is greater than 1.0 × 10−4 cm2 V−1 s−1 for the numerical calculation, the calculated mobility decreases with increasing contact resistance. Such information is an important guideline for the accurate measurements of mobility in single-injection SCL diodes.
Performance improvement of flexible bulk heterojunction solar cells using PTB7:PC71BM by optimizing spin coating and drying processes
Authors: Ohzeki Masaya , Fujii Shunjiro , Arai Yuki , Yanagidate Tatsuki , Yanagi Yuichiro , Okukawa Takanori , Yoshida Akira , Kataura Hiromichi , Nishioka Yasushiro
Published: January 2014

Bulk-heterojunction solar cells were fabricated using a dichlorobenzene solution of poly[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]-thiophenediyl] (PTB7):[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) on a flexible indium–tin-oxide-coated polyethylene terephthalate substrate. It was found that the performance of the solar cells could be markedly improved by minimizing the spin coating time of a blend of PTB7 and PC71BM to 10 s and maximizing the successive drying and solidification time up to 30 min in a confined Petri dish. As a result, a short-circuit current density of 14.5 mA/cm2, an open-circuit voltage of 0.62 V, and a power conversion efficiency of 3.67% were obtained. These improvements are attributed to the growth of favorable nanostructures during the slow drying process that increased the photocarrier collection efficiency while simultaneously increasing the performance fluctuations of each device.
The Transposition of European Union Open Data/Public Sector Information Policies in Greece: A Critical Analysis
Authors: Tsiavos Prodromos , Stefaneas Petros , Karounos Theodoros
Published: January 2014

The successful implementation of the European Union (EU) public sector information (PSI) Directive and the relevant open data (OD) policies promises financial growth, social benefits, and the creation of jobs. While Greece has transposed all relevant EU Directives and has frequently made reference to the Digital Agenda for Europe: A Europe 2020 Initiative Agenda in its own policy documents, it has failed to implement effectively OD regulation and open up PSI. This failure may to a great extent be attributed to the absence of a middle layer of regulation between the law and standard public licenses; a regulatory vacuum that hinders both the operationalization of the law and the development of technological infrastructures, while managing to avoid being classified as a violation of the PSI Directive transposition. Using Lessig's four modalities of regulation, we conclude that the promised benefits of OD will only be achieved when all the necessary legal, technical, cultural, and economic regulatory elements are fully operational. Focusing merely on the opening up of data in the absence of the right financial and institutional conditions will not produce the desired results.
Change of stress regime during geothermal reservoir stimulation
Authors: Schoenball Martin , Dorbath Louis , Gaucher Emmanuel , Wellmann J. Florian , Kohl Thomas
Published: January 2014

Earthquakes are induced by man‐made changes of the stress field by injection or withdrawal of fluids in hydrocarbon production, geothermal exploitation, and wastewater disposal. However, the actual perturbation of the stress field and stress release by injection‐induced seismicity remains largely unknown. We provide evidence for currently not understood hydromechanical processes after shut‐in of the well. We invert earthquake focal mechanisms from a massive stimulation to invert for stress resolved in time and depth to obtain changes of the stress orientation and magnitude. Prior information about fracture orientations from well logs is taken into account. Comparison with independent stress measures reveals that stresses obtained from inversion of fluid‐induced seismicity are highly perturbed and not representative of the initial stress field. The horizontal stresses change by tens of megapascals, turning the stress regime from transitional normal faulting/strike‐slip faulting to pure normal faulting. The observed stress changes are attributed to large‐scale aseismic deformation.
Seismic anisotropy and mantle flow beneath the northern Great Plains of North America
Authors: Yang Bin B. , Gao Stephen S. , Liu Kelly H. , Elsheikh Ahmed A. , Lemnifi Awad A. , Refayee Hesham A. , Yu Youqiang
Published: January 2014

A diverse set of tectonic features and the recent availability of high‐quality broadband seismic data from the USArray and other stations on the northern Great Plains of North America provide a distinct opportunity to test different anisotropy‐forming mechanisms. A total of 4138 pairs of well‐defined splitting parameters observed at 445 stations show systematic spatial variations of anisotropic characteristics. Azimuthally invariant fast orientations subparallel to the absolute plate motion (APM) direction are observed at most of the stations on the Superior Craton and the southern Yavapai province, indicating that a single layer of anisotropy with a horizontal axis of symmetry is sufficient to explain the anisotropic structure. For areas with simple anisotropy, the application of a procedure for estimating the depth of anisotropy using spatial coherency of splitting parameters results in a depth of 200–250 km, suggesting that the observed anisotropy mostly resides in the upper asthenosphere. In the vicinity of the northern boundary of the Yavapai province and the Wyoming Craton, the splitting parameters can be adequately explained by a two‐horizontal layer model. The lower layer has an APM‐parallel fast orientation, and the upper layer has a fast orientation that is mostly consistent with the regional strike of the boundary. Based on the splitting measurements and previous results from seismic tomography and geodynamic modeling, we propose a model involving deflecting of asthenosphere flow by the bottom of the lithosphere and channeling of flow by a zone of thinned lithosphere approximately along the northern boundary of the Yavapai province.
Experimental observations of the splitting of a gravity current at a density step in a stratified water body
Authors: Cortés A. , Rueda F. J. , Wells M. G.
Published: January 2014

When a gravity current reaches the level of neutral buoyancy in a stratified water body it can separate from the sloping boundary as an intrusion. If there is a density gradient within the gravity current, then multiple intrusions can form in the stratified water body. Using a series of laboratory experiments in a two‐layered ambient stratification, we document how a gravity current splits in two upon reaching the sharp density step. Our laboratory observations stress the significance of the densimetric Froude number of the gravity current (Fr), as well as a measure of the ambient stratification (density Richardson number, Riρ), on determining how a gravity current intrudes into a two‐layered stratified ambient water. Gravity currents are more likely to detrain into two parts at a density step when they have a diffuse density interface (Fr > 1). However, gravity currents tend to intrude as a single intrusion when they have a sharp, more step‐like density profile (Fr < 1). Using details of the internal structure of the gravity current, we develop a theory to predict the partition of the buoyancy flux into the interflow and underflow when the gravity current splits at the density step. Our predictions of buoyancy portions are in agreement with our experimental observations. We discuss when the application of our equations will be relevant for river intrusions into reservoirs, and for gravity currents in the stratified ocean.
Pulsed, cross‐shelf export of terrigenous dissolved organic carbon to the Gulf of Mexico
Authors: Fichot Cédric G. , Lohrenz Steven E. , Benner Ronald
Published: January 2014

The export of terrigenous dissolved organic carbon (tDOC) and other river‐borne material across the continental shelf boundary has important ramifications for biological productivity and the cycling of continentally derived bioelements in the ocean. Recent studies revealed the 275–295 nm spectral slope coefficient of chromophoric dissolved organic matter (CDOM), S275–295, is a reliable tracer for terrigenous dissolved organic carbon (tDOC) in river‐influenced ocean margins. Here an empirical algorithm for the accurate retrieval of S275–295 from ocean color was developed and validated using in situ optical properties collected seasonally in the northern Gulf of Mexico. This study also demonstrated S275–295 is a robust proxy for tDOC concentration in this environment, thereby providing a means to derive surface tDOC concentrations on synoptic scales and in quasi‐real time using remote sensing. The resulting tDOC‐algorithm was implemented using Aqua‐MODIS in a retrospective analysis of surface tDOC concentrations over the northern Gulf of Mexico between July 2002 and June 2013. Large pulses of tDOC were observed in continental‐slope surface waters off the Mississippi River delta, indicating cross‐shelf export of tDOC was sporadic and exhibited considerable interannual variability. Favorable winds following an anomalously high discharge from the Mississippi‐Atchafalaya river system always coincided with a major export event, and in general, cross‐shelf export was enhanced during years of anomalously high discharge. The tDOC‐algorithm will find applicability in the assessment of future climate‐ and human‐induced changes in tDOC export, in biogeochemical models of the continental shelf, and in the validation of high‐resolution coastal models of buoyancy‐driven shelf circulation.
Satellite observations of CO2 from a highly elliptical orbit for studies of the Arctic and boreal carbon cycle
Authors: Nassar Ray , Sioris Chris E. , Jones Dylan B. A. , McConnell John C.
Published: January 2014

Here we report on an observing system simulation experiment (OSSE) to compare the efficacy of near‐infrared satellite observations of CO2 from a highly elliptical orbit (HEO) and a low Earth orbit (LEO), for constraining Arctic and boreal CO2 sources and sinks. The carbon cycle at these latitudes (~50–90°N) is primarily driven by the boreal forests, but increasing anthropogenic activity and the effects of climate change such as thawing of permafrost throughout this region could also have an important role in the coming years. A HEO enables quasi‐geostationary observations of Earth's northern high latitudes, which are not observed from a geostationary orbit. The orbit and observing characteristics for the HEO mission are based on the Weather, Climate and Air quality (WCA) concept proposed for the Polar Communications and Weather (PCW) mission, while those for the LEO mission are based on the Greenhouse gases Observing Satellite (GOSAT). Two WCA instrument configurations were investigated. Adopting the Optimal configuration yielded an observation data set that gave annual Arctic and boreal regional terrestrial biospheric CO2 flux uncertainties an average of 30% lower than those from GOSAT, while a smaller instrument configuration resulted in uncertainties averaging 20% lower than those from GOSAT. For either WCA instrument configuration, much greater reductions in uncertainty occur for spring, summer, and autumn than for winter, with Optimal flux uncertainties for June–August nearly 50% lower than from GOSAT. These findings demonstrate that CO2 observations from HEO offer significant advantages over LEO for constraining CO2 fluxes from the Arctic and boreal regions.
Impacts of salt marsh plants on tidal channel initiation and inheritance
Authors: Schwarz C. , Ye Q. H. , van der Wal D. , Zhang L. Q. , Bouma T. , Ysebaert T. , Herman P. M. J.
Published: January 2014

At the transition between mudflat and salt marsh, vegetation is traditionally regarded as a sustaining factor for previously incised mudflat channels, able to conserve the channel network via bank stabilization following plant colonization (i.e., vegetation‐stabilized channel inheritance). This is in contrast to recent studies revealing vegetation as the main driver of tidal channel emergence through vegetation‐induced channel erosion. We present a coupled hydrodynamic morphodynamic plant growth model to simulate plant expansion and channel formation by our model species (Spartina alterniflora) during a mudflat‐salt marsh transition with various initial bathymetries (flat, shoal dense, shoal sparse, and deep dense channels). This simulated landscape development is then compared to remote sensing images of the Yangtze estuary, China, and the Scheldt estuary in Netherlands. Our results propose the existence of a threshold in preexisting mudflat channel depth, which favors either vegetation‐stabilized channel inheritance or vegetation‐induced channel erosion processes. The increase in depth of preexisting mudflat channels favors flow routing through them, consequently leaving less flow and momentum remaining for vegetation‐induced channel erosion processes. This threshold channel depth will be influenced by field specific parameters such as hydrodynamics (tidal range and flow), sediment characteristics, and plant species. Hence, our study shows that the balance between vegetation‐stabilized channel inheritance and vegetation‐induced channel erosion depends on ecosystem properties.
Conductive Transparent TiNx/TiO2 Hybrid Films Deposited on Plastics in Air Using Atmospheric Plasma Processing
Authors: Dong Siming , Watanabe Makoto , Dauskardt Reinhold H.
Published: January 2014

The successful deposition of conductive transparent TiNx/TiO2 hybrid films on both polycarbonate and silicon substrates from a titanium ethoxide precursor is demonstrated in air using atmospheric plasma processing equipped with a high‐temperature precursor delivery system. The hybrid film chemical composition, deposition rates, optical and electrical properties along with the adhesion energy to the polycarbonate substrate are investigated as a function of plasma power and plasma gas composition. The film is a hybrid of amorphous and crystalline rutile titanium oxide phases and amorphous titanium nitride that depend on the processing conditions. The visible transmittance increases from 71% to 83% with decreasing plasma power and increasing nitrogen content of the plasma gas. The film resistivity is in the range of ∼8.5 × 101 to 2.4 × 105 ohm cm. The adhesion energy to the polycarbonate substrate varies from ∼1.2 to 8.5 J/m2 with increasing plasma power and decreasing plasma gas nitrogen content. Finally, annealing the film or introducing hydrogen to the primary plasma gas significantly affects the composition and decreases thin‐film resistivity.
Helminths and human ancestral immune ecology: What is the evidence for high helminth loads among foragers?
Authors: London Douglas , Hruschka Daniel
Published: January 2014

Objectives

Recent theories of human immune ecology have invoked high helminth loads as an important selection factor among early humans. However, few studies have assessed this assumption among extant human foragers.

Methods

We review the current evidence for high helminth loads in documented forager populations and present new data from members of a Kawymeno Waorani forager group in Amazonian Ecuador (n = 16) compared with neighboring Kichwa subsistence farmers (n = 63).

Results

Stool samples indicated a near absence of helminths among the Kawymeno foraging group (6.25% with Ascaris lumbricoides and 0% with Ancylostoma duodenale or Trichuris trichiura). In contrast neighboring, isolated Kichwa subsistence farmers in a similar ecosystem had abundant helminth infestations (76.1% with Ascaris lumbricoides, 11.1% with Ancylostoma duodenale, and 1.5% with Trichuris trichiura). The presence of helminths among the Waorani and Kichwa was triangulated across multiple data sources, including presence in stool samples, medical exams, and 3 years of participant observation.

Conclusions

These findings, coupled with the modern forager literature, raise questions as to whether helminths were prevalent enough in Paleolithic humans to be a unique evolutionary selective force in human physiology. Am. J. Hum. Biol. 26:124–129, 2014. © 2014 Wiley Periodicals, Inc.
Increasing breadth of the frontal lobe but decreasing height of the human brain between two Chinese samples from a Neolithic site and from living humans
Authors: Liu Chao , Tang Yuchun , Ge Haitao , Wang Fen , Sun Huafu , Meng Haiwei , Wang Shaoyu , Xu Junhai , Fan Rong , Fan Lingzhong , Zhang Zhonghe , Shan Tao , Yuan Hongtu , Zhan Jinfeng , Yu Qiaowen , Ge Xinting , Tang Haiyan , Leng Yuan , Ding Shihai , Liu Shuwei
Published: January 2014

Morphological observation and measurements of endocasts have played a vital role in research on the evolution of the human brain. However, endocasts have never been used to investigate how the human brain has evolved since the Neolithic period. We investigated the evolution of the human brain during the Holocene by comparing virtual endocasts from Beiqian site (a Neolithic Chinese site) and a sample of Chinese modern‐day humans. Standardized measurements and indices were taken to provide quantification of the overall endocast shape, including the length, breadth, height, frontal breadth, and the ratio of frontal breadth to breadth, as well as the cranial capacity. We found that the height of the endocasts and cranial capacity have decreased between our two samples, whereas the frontal breadth and sexual dimorphism have increased. We argue that these changes can be caused by random genetic mutation and epigenetic change in response to changes in the environment. Am J Phys Anthropol 154:94–103, 2014. © 2014 Wiley Periodicals, Inc.
Magnetische TiO2‐Nanokomposite zur spektroskopischen Identifizierung und zum Abbau toxischer Aniline und Phenole
Authors: Han Xiao Xia , Chen Lei , Kuhlmann Uwe , Schulz Claudia , Weidinger Inez M. , Hildebrandt Peter
Published: January 2014

Benzidin und seine Derivate können im menschlichen Körper zu krebserregenden Aminen umgewandelt werden. Aus diesem Grund wird den potentiellen Risiken (z. B. Blasenkrebs) bei Kontakt mit kommerziell erhältlichen Benzidin‐haltigen und analogen Farbstoffen wachsende Aufmerksamkeit geschenkt.1, 2 Einige Phenolderivate, die in der Herstellung alltäglicher Produkte eingesetzt werden, haben Ähnlichkeiten mit hormonaktiven Stoffen und erhöhen möglicherweise das Brustkrebsrisiko.3, 4 In der hier vorgestellten Arbeit haben wir zum ersten Mal multifunktionale Nanokomposite konstruiert, die den hochempfindlichen Nachweis, die Manipulation und lichtinduzierte Zersetzung toxischer Benzidin‐ und Phenolderivate ermöglichen. Magnetische TiO2‐Nanokomposite (M‐TiO2‐NCs) wurden synthetisiert und mit p‐Aminothiophenol (PATP) zur Bindung der Zielmoleküle über eine Azo‐Kupplung funktionalisiert. Anhand der spezifischen spektroskopischen Signaturen in den oberflächenverstärkten Resonanz‐Raman‐Spektren (SERRS; surface‐enhanced resonance Raman scattering) der Azoprodukte war es möglich, zielgerichtet toxische Aniline und Phenole zu identifizieren und schließlich deren Azoprodukte an der TiO2‐Oberfläche photokatalytisch abzubauen, ein Prozess, der zudem durch Ausnutzung der Plasmonenresonanz eingebetteter Ag‐Partikel verstärkt werden konnte.
Minimal Tags for Rapid Dual‐Color Live‐Cell Labeling and Super‐Resolution Microscopy
Authors: Nikić Ivana , Plass Tilman , Schraidt Oliver , Szymański Jędrzej , Briggs John A. G. , Schultz Carsten , Lemke Edward A.
Published: January 2014

The growing demands of advanced fluorescence and super‐resolution microscopy benefit from the development of small and highly photostable fluorescent probes. Techniques developed to expand the genetic code permit the residue‐specific encoding of unnatural amino acids (UAAs) armed with novel clickable chemical handles into proteins in living cells. Here we present the design of new UAAs bearing strained alkene side chains that have improved biocompatibility and stability for the attachment of tetrazine‐functionalized organic dyes by the inverse‐electron‐demand Diels–Alder cycloaddition (SPIEDAC). Furthermore, we fine‐tuned the SPIEDAC click reaction to obtain an orthogonal variant for rapid protein labeling which we termed selectivity enhanced (se) SPIEDAC. seSPIEDAC and SPIEDAC were combined for the rapid labeling of live mammalian cells with two different fluorescent probes. We demonstrate the strength of our method by visualizing insulin receptors (IRs) and virus‐like particles (VLPs) with dual‐color super‐resolution microscopy.
Evaluation of the properties of bitumen modified by SBS copolymers with different styrene–butadiene structure
Authors: Zhang Qinqin , Wang Tiezhu , Fan Weiyu , Ying Yang , Wu Yumin
Published: January 2014

Four styrene–butadiene–styrene(SBS) modified bitumens had been prepared by a base bitumen, a crosslinking agent and four SBS copolymers which differ in styrene blocks content and molecular configuration (radial or linear) under the same experimental conditions. Conventional properties, morphology, thermal behavior and microstructure were investigated by means of conventional tests, fluorescence microscopy, differential scanning calorimetry (DSC), and Fourier transform infrared (FT‐IR) spectroscopy. In terms of linear SBS polymers, the SBS molecule with the styrene content of 30% has a perfect dispersion and complete stretching in bitumen matrix, and in this case, the conventional properties and thermal stability of bitumen are enhanced substantially. However, the star SBS polymer due to long branched chains forming the preferable steric hindrance to enhance the intensity of base bitumen, plays a more important role in improving the conventional properties of base bitumen than linear SBS polymers. Furthermore, the FT‐IR spectra indicate that, the main bands assignations of four modified bitumens are identical and the significant variation is the peak intensity. And a noncomplete crosslinking reaction happens between the bitumen and each SBS polymer, which can efficiently prevent excessive cross‐linking from affecting the intrinsic bitumen characteristics. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40398.
SUPPRESSING THE EXPRESSION OF A FORKHEAD TRANSCRIPTION FACTOR DISRUPTS THE CHITIN BIOSYNTHESIS PATHWAY IN Spodoptera exigua
Authors: Zhao Lina , Wei Ping , Guo Hongshuang , Wang Shigui , Tang Bin
Published: January 2014

Forkhead (Fox) transcription factors display functional diversity and are involved in various metabolic and developmental processes. The Spodoptera exigua Fox (SeFox) encodes a protein of 353 amino acids with a theoretical molecular mass of approximately 38.99 kDa and an isoelectric point of 8.86. qPCR results revealed that SeFox was expressed mainly in the brain, fat body, epidermis, midgut, Malpighian tubules, and testis. SeFox was expressed, with some changes, throughout development in the fat body and whole body. Injection of dsSeFox (SeFox dsRNA) into larvae resulted in incidences of albino plus molting deformity (4.8%), molting deformity (26.2%), and albino phenotypes (69.1%). dsSeFox injection resulted in approximately 50% knockdown of transcript levels at 36 h. Compared with control groups, hexokinase (HK) expression was reduced to approximately 40% at 48 h postinjection. Chitin synthase A (CHSA) expression was reduced to two‐thirds at 24 h, but increased at 72 h. Compared with untreated control and green fluorescent protein‐treated groups, Chitin synthase B (CHSB) expression decreased to 33% following dsSeFox injection by 36 h. We infer from our results that forkhead transcription factors act in chitin synthesis in S. exigua.
Induction of foetal haemoglobin synthesis in erythroid progenitor stem cells: mediated by water‐soluble components of Terminalia catappa
Authors: Aimola I. A. , Inuwa H. M. , Nok A. J. , Mamman A. I.
Published: January 2014

Current novel therapeutic agents for the treatment of sickle cell anaemia (SCA) focus on increasing foetal haemoglobin (HbF) levels in SCA patients. Unfortunately, the only approved HbF‐inducing agent, hydroxyurea, has long‐term unpredictable side effects. Studies have shown the potential of plant compounds to modulate HbF synthesis in primary erythroid progenitor stem cells. We isolated a novel HbF‐inducing Terminalia catappa distilled water active fraction (TCDWF) from Terminalia catappa leaves that induced the commitment of erythroid progenitor stem cells to the erythroid lineage and relatively higher HbF synthesis of 9.2‐ and 6.8‐fold increases in both erythropoietin (EPO)‐independent and EPO‐dependent progenitor stem cells respectively. TCDWF was differentially cytotoxic to EPO‐dependent and EPO‐independent erythroid progenitor stem cell cultures as revealed by lactate dehydrogenase release from the cells. TCDWF demonstrated a protective effect on EPO‐dependent and not EPO‐independent progenitor cells. TCDWF induced a modest increase in caspase 3 activity in EPO‐independent erythroid progenitor stem cell cultures compared with a significantly higher (P˂0.05) caspase 3 activity in EPO‐dependent ones. The results demonstrate that TCDWF may hold promising HbF‐inducing compounds, which work synergistically, and suggest a dual modulatory effect on erythropoiesis inherent in this active fraction. Copyright © 2014 John Wiley & Sons, Ltd.
Identification and Biosynthesis of New Acyloins from the Thermophilic Bacterium Thermosporothrix hazakensis SK20‐1T
Authors: Park Jin‐Soo , Kagaya Noritaka , Hashimoto Junko , Izumikawa Miho , Yabe Shuhei , Shin‐ya Kazuo , Nishiyama Makoto , Kuzuyama Tomohisa
Published: January 2014

Two new acyloin compounds were isolated from the thermophilic bacterium Thermosporothrix hazakensis SK20‐1T. Genome sequencing of the bacterium and biochemical studies identified the thiamine diphosphate (TPP)‐dependent enzyme Thzk0150, which is involved in the formation of acyloin. Through extensive analysis of the Thzk0150‐catalyzed reaction products, we propose a putative reaction mechanism involving two substrates: 4‐methyl‐2‐oxovalerate as an acyl donor and phenyl pyruvate as an acyl acceptor.
Ebselen exhibits glycation‐inhibiting properties and protects against osmotic fragility of human erythrocytes in vitro
Authors: Soares Julio C. M. , Folmer Vanderlei , Da Rocha João B. T. , Nogueira Cristina W.
Published: January 2014

Diabetic status is associated with an increase on oxidative stress markers in humans and animal models. We have investigated the in vitro effects of high concentrations of glucose on the profile of oxidative stress and osmotic fragility of blood from control and diabetic patients; we considered whether its antioxidant properties could afford some protection against glucose‐induced osmotic fragility, and whether ebselen could act as an inhibitor of hemoglobin glycation. Raising blood glucose to 5–100 mmol/L resulted in a concentration‐dependent increase of glycated hemoglobin (HbA1c; P < 0.001) and thiobarbituric acid reactive species (TBA‐RS) content (P < 0.004). Non‐protein SH groups (NPSH) also increased significantly as the concentration of glucose increased up to 30 mmol/L (P < 0.001). The osmotic fragility was more pronounced in blood of uncontrolled diabetic patients than in these non‐diabetic subjects. Ebselen significantly reduced the glucose‐induced increase in osmotic fragility and inhibited HbA1c formation (P < 0.0001). These results indicate that blood from patients with uncontrolled diabetes are more sensitive to osmotic shock than from patients with controlled diabetes and control subjects in relation to increased production of free radicals in vivo.
Separated performances of ammonium sulphate and ammonium chloride solutions treated by vacuum membrane distillation
Authors: You Wen‐Ting , Xu Zhen‐Liang , Dong Zhe‐Qing , Zhao Yu‐Jie
Published: January 2014

Polytetrafluoroethylene (PTFE) flat‐sheet membrane with the mean pore size of 0.1 μm was used to treat the high concentration (NH4)2SO4 and NH4Cl solutions by vacuum membrane distillation (VMD). The permeate flux was varied in the range 8–48 L h−1 m−2 and was dependent on the operating conditions. The effects of permeate pressures and feed parameters in terms of pH values, feed temperature, flow rate and feed concentration on both the permeate fluxes and the permeate concentrations of total nitrogen (TN) were investigated. Experiment results showed the feed temperature has the most significant effect on the permeate flux. The feed pH value was observed to be the most dominant factor on permeate concentration of TN. Ammonium was rejected with low feed pH value, high feed temperature and low permeate pressure. When the feed pH value was 3, the permeate concentration of TN was kept in the range of 1–3 mg/L and the ammonia nitrogen rejection rate is 99.95%, despite that the feed concentration was increased.
Enantioseparation of racemic mandelic acid by simulated moving bed chromatography using Chiralcel‐OD column
Authors: Mao Shimin , Zhang Yan , Rohani Sohrab , Ray Ajay K.
Published: January 2014

The chiral separation of the racemic mandelic acid ((R,S)‐MA) by simulated moving bed chromatography with columns packed with Chiralcel‐OD stationary phase is investigated experimentally and numerically. The transport dispersion model combined with the modified Langmuir isotherm was applied to predict the dynamic behaviour and separation performance of the SMB process. The Triangle Theory was used to obtain the complete separation region of the SMB operation. The influences of the switching time, loading, extract flow rate and column configuration on the SMB performance were also studied. The online monitoring system consisting of circular dichroism (CD) and UV detector in series was employed to measure the composition and purity of the extract and raffinate streams. Good agreement between the experimental data and model predictions proved the efficiency and reliability of SMB modelling and the Triangle theory in the design and operation of SMB chromatography. Experimental results show that purity and recovery at extract and raffinate port can reach 99% although not at the same time.
Thrombotic microangiopathy in metastatic melanoma patients treated with adoptive cell therapy and total body irradiation
Authors: Tseng Jennifer , Citrin Deborah E. , Waldman Meryl , White Donald E. , Rosenberg Steven A. , Yang James C.
Published: January 2014

BACKGROUND

Thrombotic microangiopathy (TMA) is a complication that developed in some patients receiving 12 Gy total body irradiation (TBI) in addition to lymphodepleting preparative chemotherapy prior to infusion of autologous tumor‐infiltrating lymphocytes (TIL) with high‐dose aldesleukin (IL‐2). This article describes the incidence, presentation, and course of radiation‐associated TMA.

METHODS

The data for patients with metastatic melanoma who received ACT with TIL plus aldesleukin following myeloablative chemotherapy and 12‐Gy TBI was examined, in order to look at patient characteristics and the natural history of TMA.

RESULTS

The median time to presentation was approximately 8 months after completing TBI. The estimated cumulative incidence of TMA was 31.2% (median follow‐up of 24 months). Noninvasive criteria for diagnosis included newly elevated creatinine levels, new‐onset hypertension, new‐onset anemia, microscopic hematuria, thrombocytopenia, low haptoglobin, and elevated lactate dehydrogenase values. Once diagnosed, patients were managed with control of their hypertension with multiple agents and supportive red blood cell transfusions. TMA typically stabilized or improved and no patient progressed to dialysis. TMA was associated with a higher probability of an antitumor response.

CONCLUSIONS

TMA occurs in approximately a third of patients treated with a lymphodepleting preparative chemotherapy regimen with TBI prior to autologous T cell therapy. The disease has a variable natural history, however, no patient developed end‐stage renal failure. Successful management with supportive care and aggressive hypertension control is vital to the safe application of a systemic therapy that has shown curative potential for patients with disseminated melanoma. Cancer 2014;120:1426–1432. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
A Chemosensor Bearing Sulfonyl Azide Moieties for Selective Chromo‐Fluorogenic Hydrogen Sulfide Recognition in Aqueous Media and in Living Cells
Authors: Santos‐Figueroa Luis E. , de laTorre Cristina , El Sayed Sameh , Sancenón Félix , Martínez‐Máñez Ramón , Costero Ana M. , Gil Salvador , Parra Margarita
Published: January 2014

A simple chemodosimeter based on a sulfonyl azide dye (1‐Az), which displayed a highly selective response toward hydrogen sulfide anion in mixed aqueous media, was synthesised and characterised. Addition of hydrogen sulfide to acetonitrile/HEPES 1:1 solutions of 1‐Az induced a clear colour change from red‐orange to yellow, which was easily detected by the naked eye, and by an enhancement in the emission intensity. Other common anions, thiol‐containing biomolecules and oxidants did not induce any noticeable colour or fluorescence modulation in the probe. The chemodosimeter also showed a good sensitivity, with limits of detection of 11.91 and 0.63 μM by using UV/Vis or fluorescence measurements, respectively. Moreover, 1‐Az could be used for real‐time fluorescence imaging of intracellular HS– at micromolar concentrations.
Total Syntheses of Cochliomycin B and Zeaenol
Authors: Gao Yangguang , Liu Jun , Wang Linlin , Xiao Ming , Du Yuguo
Published: January 2014

Divergent syntheses of two 14‐membered resorcylic acid lactones (RALs), cochliomycin B (6) and zeaenol (22), have been accomplished. The key feature in our strategy was the facile construction of three contiguous stereogenic centers in the title molecules by using natural L‐arabinose as the chiral template. The key reactions included Takai olefination, Suzuki cross coupling, transesterification, and a late‐stage ring‐closing metathesis (RCM).
Lewis Acid Assisted Decomplexation of F‐BODIPYs to Dipyrrins
Authors: Lakshmi Vellanki , Chatterjee Tamal , Ravikanth Mangalampalli
Published: January 2014

A simple synthetic route was developed for the decomplexation of F‐BODIPYs (fluorine‐substituted boron–dipyrromethenes) to afford dipyrrins in high yields. This was achieved by treating the F‐BODIPYs with different Lewis acids such as ZrCl4, TiCl4, AlCl3, Sc(OTf)3, or SnCl4 in CH3CN/CH3OH under refluxing conditions. This synthetic strategy was efficient for different types of F‐BODIPYs such as meso‐aryl‐substituted BODIPYs, 3‐pyrrolyl BODIPYs, functionalized 3‐pyrrolyl BODIPYs, π‐extended pyrrolyl BODIPYs, sterically crowded BODIPYs, and the BF2 complex of 25‐oxasmaragdyrin.
Delayed delivery from the sediment factory: modeling the impact of catchment response time to tectonics on sediment flux and fluvio‐deltaic stratigraphy
Authors: Forzoni Andrea , Storms Joep E.A. , Whittaker Alexander C. , de Jager Gerben
Published: January 2014

The sediment flux from a catchment is driven by tectonics and climate but is moderated by the geomorphic response of the landscape system to changes in these two boundary conditions. Consequently, catchment response time and the non‐linear behavior of landscapes in response to boundary condition change control the downstream propagation of climatic or tectonic perturbations from catchments to neighboring basins. In order to investigate the impact of catchment response time on sediment flux, we integrated a spatially‐lumped numerical model PaCMod, with new routines simulating the evolution of landscape morphology and erosion rates under tectonic and climatic forcing. We subsequently applied the model to reconstruct the sediment flux from a tectonically perturbed catchment in central Italy. Finally, we coupled our model to DeltaSim, a process‐response model simulating fluvio‐deltaic stratigraphy, and investigated the impact of catchment response time on stratigraphy, using both synthetic scenarios and a real world system (Fucino Basin, central Italy). Our results demonstrate that the differential response of geomorphic elements to tectonic and climatic changes induces a complex sediment flux signal, and produces characteristic stratigraphic architectures and shoreline trajectories. Copyright © 2014 John Wiley & Sons, Ltd.