bluuebunny/crossref_metadata_2025 huggingface dataset:
Daily minimum and maximum surface air temperatures from geostationary satellite data
Authors: Good Elizabeth
Published: February 2015

Observations of daily minimum and maximum land air temperatures, Tmin and Tmax, have traditionally been obtained through in situ observations at meteorological stations. While the station network is extensive, many land masses are poorly observed. Moreover, observations at stations are “point” observations and may not be representative of air temperatures at neighboring locations. Satellites provide the means to observe surface skin temperatures at spatial scales of tens of meters to kilometers. But although skin and near‐surface air temperatures may be strongly coupled, the two quantities can differ by several degrees over land, where the magnitude of the difference is variable in both space and time. This study describes a method for estimating daily Tmin and Tmax at the pixel scale using geostationary satellite data, providing spatially detailed observations for areas unobserved in situ. A dynamic multiple linear regression model is developed using daily minimum and maximum land surface temperature (LSTmin and LSTmax), fraction of vegetation, distance from coast, latitude, urban fraction, and elevation as predictors. The method is demonstrated over Europe for 2012–2013; evaluation with collocated station observations indicates a mean satellite‐minus‐station bias of 0.0 to 0.5°C with root‐mean‐square difference of 2.3 to 2.7°C. The data derived here are not designed to replace traditional gridded station air temperature data sets, but to augment them. Satellite surface temperature data usually have larger uncertainties than in situ data sets, but they can offer spatial detail and coverage that the latter may not provide.
Tides on the Moon: Theory and determination of dissipation
Authors: Williams James G. , Boggs Dale. H.
Published: February 2015

Solid body tides on the Moon vary by about ±0.1 m each month. In addition to changes in shape, the Moon's gravity field and orientation in space are affected by tides. The tidal expressions for an elastic sphere are compact, but dissipation introduces modifications that depend on the forcing period. Consequently, a Fourier representation of the tide‐raising potential is needed. A mathematical model for the distortion‐caused tidal potential may be used for the analysis of precise spacecraft tracking data. Since tides affect gravitational torques on the Moon from the Earth's attraction, the lunar orientation is also affected. Expressions for five periodic perturbations of orientation are presented. The rheological properties of lunar materials determine how the Moon responds to different tidal periods. New lunar laser ranging solutions for the tidal orientation terms are presented. The quality factor Q is 38 ± 4 at 1 month, 41 ± 9 at 1 year, ≥74 at 3 years, and ≥58 at 6 years. The ranging results can be matched with absorption band models that peak at ~120 days and single relaxation time models that peak at ~100 days. Combined models are possibilities. Dissipation can modify laser ranging solutions; previously reported core flattening is too uncertain to be useful. Strong lunar tidal dissipation, modeled to arise in the deep hot mantle, appears to be from a region with radius ≥535 km. Classical Maxwell‐type dissipation is too weak to detect at 3 and 6 year periods.
Partial net primary production of a mixed dipterocarp forest: Spatial patterns and temporal dynamics
Authors: Tan Zheng‐Hong , Deng Xiao‐Bao , Hughes Alice , Tang Yong , Cao Min , Zhang Wen‐Fu , Yang Xiao‐Fei , Sha Li‐Qing , Song Liang , Zhao Jun‐Fu
Published: February 2015

We examined how and why partial net primary production (NPPpart) varies across time and space in a Chinese dipterocarp forest. We hypothesize that (1) soil geochemistry explains the spatial pattern of NPPpart within the plot and (2) NPPpart can be used to measure the degree of drought resilience of a natural forest. Spatially, NPPpart was autocorrelated in the range of 75.3 m and homogenous. This spatial pattern could not be well explained by any of the soil properties individually or in combination. If drought sensitivity is defined by marked reduction in NPPpart, the studied forest is drought resilient even when a longer and drier than usual drought hit. Although annual NPPpart was unchanged (vary within 18.24 and 18.52 t ha−1 yr−1) after the drought, the allocation of NPPpart to short‐lived litterfall increased, which has further effects on the ecosystem net carbon balance.
Design of reflectarray antennas to achieve an optimum near‐field radiation for RFID applications via the implementation of SDM procedure
Authors: Chou Hsi‐Tseng , Liu Yu‐Xi , Dong Xiao‐Ying , You Bai‐Qiang , Kuo Li‐Ruei
Published: February 2015

This paper presents the design of reflectarray antennas to radiate an optimum near‐field distribution by using the procedure of steepest decent method to synthesize the impressed phases of reflectarray elements. In particular, the closed‐form formulations used in the electromagnetic modeling were developed for an efficient design. The design was further implemented to realize a reflectarray of microstrip patch elements, which is illuminated by the radiation of a feed antenna at the 2.4 GHz band in the radio frequency identification applications. Numerical investigations as well as experimental measurements over a prototype are presented to validate the feasibility of the developed models and the implemented antenna structure.
Antarctica's Dry Valleys: A potential source of soluble iron to the Southern Ocean?
Authors: Bhattachan Abinash , Wang Lixin , Miller Molly F. , Licht Kathy J. , D'Odorico Paolo
Published: February 2015

The soluble iron content and dust emission potential of sediment samples collected from the Taylor Valley in the McMurdo Dry Valleys (MDVs) and sea ice in the McMurdo Sound were evaluated to determine whether inputs to the Southern Ocean may be sufficient to affect ocean productivity. Our results show that the dust‐generating potential from the MDVs soils are comparable to those of sediments from other major dust sources in the Southern Hemisphere. Sediments from the MDVs and sea ice are one order of magnitude richer in soluble iron than those in other dust sources in the Southern Hemisphere. Forward trajectory analyses show that the dust from the MDVs is likely to be deposited in the Southern Ocean. These results provide evidence of the possible supply of soluble iron to the Southern Ocean associated with dust transport from the MDVs, should climate change expand the exposed areas of the continent.
Facet‐Level Mechanistic Insights into General Homogeneous Carbon Doping for Enhanced Solar‐to‐Hydrogen Conversion
Authors: Li Jie , Zhao Kun , Yu Ying , Zhang Lizhi
Published: February 2015

Homogeneous doping can boost solar‐to‐hydrogen conversion and therefore attracts great attention. Although a great deal of effort has been made to explore the doping–photoreactivity relationship, the doping mechanisms, especially from the perspective of crystal facets, are seldom explored. In this study, a general homogeneous carbon doping strategy is established and then serves as the doping model for a mechanistic investigation, as encouraged by its versatility in enabling homogeneous incorporation of carbon and improving solar‐to‐hydrogen conversion for typical oxides including TiO2, ZnO, and BiOCl. Using well‐defined BiOCl nanosheets of high {001} or {010} facet exposure, we clarify the homogeneous carbon doping mechanism at the level of crystal facets for the first time. This mechanism involves the initial facet‐dependent adsorption of the dopant precursor, regulated by the surface atomic structures, and the subsequent facet‐dependent diffusion of carbon dopants associated with the facet‐related arrangements of bulk atoms. This results in facet‐dependent carbon doping behavior and a dopant‐concentration‐dependent solar‐to‐hydrogen conversion property of BiOCl nanosheets. These mechanistic insights also suggest that the implantation of the dopant precursor in the shallow lattice of host nanocrystal is vital for the effective homogeneous doping. This new doping model is different from the conventional counterpart based on the organic ligands or gas molecules adsorption onto the surface of host nanocrystals, where surface doping usually occurs.
Microfluidic Spinning of Cell‐Responsive Grooved Microfibers
Authors: Shi Xuetao , Ostrovidov Serge , Zhao Yihua , Liang Xiaobin , Kasuya Motohiro , Kurihara Kazue , Nakajima Ken , Bae Hojae , Wu Hongkai , Khademhosseini Ali
Published: February 2015

Engineering living tissues that simulate their natural counterparts is a dynamic area of research. Among the various models of biological tissues being developed, fiber‐shaped cellular architectures, which can be used as artificial blood vessels or muscle fibers, have drawn particular attention. However, the fabrication of continuous microfiber substrates for culturing cells is still limited to a restricted number of polymers (e.g., alginate) having easy processability but poor cell–material interaction properties. Moreover, the typical smooth surface of a synthetic fiber does not replicate the micro‐ and nanofeatures observed in vivo, which guide and regulate cell behavior. In this study, a method to fabricate photocrosslinkable cell‐responsive methacrylamide‐modified gelatin (GelMA) fibers with exquisite microstructured surfaces by using a microfluidic device is developed. These hydrogel fibers with microgrooved surfaces efficiently promote cell encapsulation and adhesion. GelMA fibers significantly promote the viability of cells encapsulated in/or grown on the fibers compared with similar grooved alginate fibers used as controls. Importantly, the grooves engraved on the GelMA fibers induce cell alignment. Furthermore, the GelMA fibers exhibit excellent processability and could be wound into various shapes. These microstructured GelMA fibers have great potential as templates for the creation of fiber‐shaped tissues or tissue microstructures.
Additively Manufactured Device for Dynamic Culture of Large Arrays of 3D Tissue Engineered Constructs
Authors: Costa Pedro F. , Hutmacher Dietmar W. , Theodoropoulos Christina , Gomes Manuela E. , Reis Rui L. , Vaquette Cédryck
Published: February 2015

The ability to test large arrays of cell and biomaterial combinations in 3D environments is still rather limited in the context of tissue engineering and regenerative medicine. This limitation can be generally addressed by employing highly automated and reproducible methodologies. This study reports on the development of a highly versatile and upscalable method based on additive manufacturing for the fabrication of arrays of scaffolds, which are enclosed into individualized perfusion chambers. Devices containing eight scaffolds and their corresponding bioreactor chambers are simultaneously fabricated utilizing a dual extrusion additive manufacturing system. To demonstrate the versatility of the concept, the scaffolds, while enclosed into the device, are subsequently surface‐coated with a biomimetic calcium phosphate layer by perfusion with simulated body fluid solution. 96 scaffolds are simultaneously seeded and cultured with human osteoblasts under highly controlled bidirectional perfusion dynamic conditions over 4 weeks. Both coated and noncoated resulting scaffolds show homogeneous cell distribution and high cell viability throughout the 4 weeks culture period and CaP‐coated scaffolds result in a significantly increased cell number. The methodology developed in this work exemplifies the applicability of additive manufacturing as a tool for further automation of studies in the field of tissue engineering and regenerative medicine.
Advances in Skin Regeneration: Application of Electrospun Scaffolds
Authors: Norouzi Mohammad , Boroujeni Samaneh Moghadasi , Omidvarkordshouli Noushin , Soleimani Masoud
Published: February 2015

The paucity of cellular and molecular signals essential for normal wound healing makes severe dermatological ulcers stubborn to heal. The novel strategies of skin regenerative treatments are focused on the development of biologically responsive scaffolds accompanied by cells and multiple biomolecules resembling structural and biochemical cues of the natural extracellular matrix (ECM). Electrospun nanofibrous scaffolds provide similar architecture to the ECM leading to enhancement of cell adhesion, proliferation, migration and neo tissue formation. This Review surveys the application of biocompatible natural, synthetic and composite polymers to fabricate electrospun scaffolds as skin substitutes and wound dressings. Furthermore, the application of biomolecules and therapeutic agents in the nanofibrous scaffolds viz growth factors, genes, antibiotics, silver nanoparticles, and natural medicines with the aim of ameliorating cellular behavior, wound healing, and skin regeneration are discussed.
Exciton–Polaron‐Induced Aggregation of Organic Electroluminescent Materials: A Major Degradation Mechanism in Wide‐Bandgap Phosphorescent and Fluorescent Organic Light‐Emitting Devices
Authors: Wang Qi , Aziz Hany
Published: February 2015

The electroluminescence (EL) degradation mechanisms of organic light‐emitting devices (OLEDs) are studied utilizing phosphorescent and fluorescent materials as emitter guests. The results show that these emitter guests, despite being used in low concentrations in OLEDs, aggregate as a result of electrical stress, giving rise to the emergence of new longer‐wavelength bands in their EL spectra after prolonged device operation. Such electrical‐driving‐induced aggregation occurs more significantly in guest materials with wider bandgap (Eg) and flatter molecular structures. Further investigations reveal that the aggregation process is mainly induced by interactions between excitons and positive polarons that reside on the guests. The findings uncover a previously unknown degradation mechanism that appears to be responsible for the generally much lower EL stability of blue devices relative to their green and red counterparts, especially in case of phosphorescent emitters.
Bioinspired Therapeutic Dendrimers as Efficient Peptide Drugs Based on Supramolecular Interactions for Tumor Inhibition
Authors: Zhang Xiao , Zhang Zhijun , Xu Xianghui , Li Yunkun , Li Yachao , Jian Yeting , Gu Zhongwei
Published: February 2015

Bioinspired tryptophan‐rich peptide dendrimers (TRPDs) are designed as a new type of dendritic peptide drugs for efficient tumor therapy. The TRPDs feature a precise molecular structure and excellent water solubility and are obtained in a facile process. Based on the unique features of peptide dendrimers, including highly branched structures, abundant terminal groups, and globular‐protein‐like architectures, the therapeutic dendrimers show significant supramolecular interactions with DNA through the tryptophan residues (indole rings and amino groups). Further experimental results indicate that TRPDs are efficient antitumor agents both in vitro and in vivo.
Structure and relaxation in cellulose hydrogels
Authors: Xia Zhiyong , Patchan Marcia , Maranchi Jeffrey , Trexler Morgana
Published: February 2015

Cellulose‐based hydrogels show great potential for a wide range of applications. However, the structure of these hydrated gels is not fully understood. The impact of moisture on the structure and stability of cellulose based hydrogels is reported in this article. Analytical data based on GPC, NMR, and rheology are discussed. It was found that moisture‐induced gelation greatly reduces the crystallinity of the hydrogels, and the release of water from the hydrogels leads to permanent structural changes in the network structure due to the reformation of hydrogen bonding. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42071.
Fuels and plastics from lignocellulosic biomass via the furan pathway: an economic analysis
Authors: Eerhart Aloysius J.J.E. , Patel Martin K. , Faaij André P.C.
Published: February 2015

Furan compounds represent a class of chemicals that have the potential to become platform chemicals due to their attractive properties thanks to their structure. In a previous publication, three biorefinery cases were presented that convert wheat straw into polyethylene furanoate (PEF) and furfuryl ethyl ether (FEE) and analyzed from a technical point of view. In this paper, the production costs were calculated using the net present value methodology, including a sensitivity analysis to determine the effects for changes in financial parameters, feedstock, chemicals, and market prices. In order to compete with petrochemical polymers, the production costs of PEF has to be around 1500 $/tonne. For the base case, all three cases approach this level of 1500 $/tonne; the production costs for Case I are 1495 $/tonne PEF and Case II at 1555 $/tonne PEF. For Case III, the costs are calculated to be negative (at −131) $/tonne. This is because PEF is not the main product within Case III, as dimethyl ether (DME) and methyl levulinate (ML) account for 75% of the product basket. The results show that the production of PEF can become a competitive alternative for petrochemical PET, under the condition of large scale production, proper price levels for the by‐products FEE and ML, and the availability of sustainable harvested wheat straw at an assumed cost between 50 and 150 $/tonne. Considering also the improved material performance of PEF and a potentially more favorable greenhouse gas (GHG) footprint, PEF produced from biomass may become a superior plastic to PET produced from petrochemical feedstocks. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd
Randomized clinical trial of skin closure by subcuticular suture or skin stapling after elective colorectal cancer surgery
Authors: Kobayashi S , Ito M , Yamamoto S , Kinugasa Y , Kotake M , Saida Y , Kobatake T , Yamanaka T , Saito N , Moriya Y
Published: February 2015

Background

The best suture method to prevent incisional surgical-site infection (SSI) after clean-contaminated surgery has not been clarified.

Methods

Patients undergoing elective colorectal cancer surgery at one of 16 centres were randomized to receive either subcuticular sutures or skin stapling for skin closure. The primary endpoint was the rate of incisional SSI. Secondary endpoints of interest included time required for wound closure, incidence of wound problems, postoperative length of stay, wound aesthetics and patient satisfaction.

Results

A total of 1264 patients were enrolled. The cumulative incidence of incisional SSI by day 30 after surgery was similar after subcuticular sutures and stapled closure (8·7 versus 9·8 per cent respectively; P = 0·576). Comparison of cumulative incidence curves revealed that SSI occurred later in the subcuticular suture group (P = 0·019) (hazard ratio 0·66, 95 per cent c.i. 0·45 to 0·97). Wound problems (P = 0·484), wound aesthetics (P = 0·182) and postoperative duration of hospital stay (P = 0·510) did not differ between the groups; subcuticular sutures took 5 min longer than staples (P < 0·001). Patients in the subcuticular suture group were significantly more satisfied with their wound (52·4 per cent versus 42·7 per cent in the staple group; P = 0·002).

Conclusion

Compared with skin stapling, subcuticular sutures did not reduce the risk of incisional SSI after colorectal surgery. Registration number: UMIN000004001 (http://www.umin.ac.jp/ctr).
Metabolic pathways visualization skills development by undergraduate students
Authors: dos Santos Vanessa J. S. V. , Galembeck Eduardo
Published: February 2015

We have developed a metabolic pathways visualization skill test (MPVST) to gain greater insight into our students' abilities to comprehend the visual information presented in metabolic pathways diagrams. The test is able to discriminate students' visualization ability with respect to six specific visualization skills that we identified as key to the understanding of metabolic map diagrams. Application of the MPVST to B. S. Biochemistry students showed that their visualization skills develop informally and progressively during their college years. Furthermore, the complex nature of biochemical pathways, together with students' lack of familiarity with metabolic maps, suggests that it is important for instructors to spend more time than usual explaining visual representations to their students. © 2015 by The International Union of Biochemistry and Molecular Biology, 43(3):162–167, 2015.
Morphological and biomechanical analyses of the subchondral mineralized zone in human sacral facet joints: Application to improved diagnosis of osteoarthritis
Authors: Berteau Jean‐Philippe , Mielke Gabriela , Morlock Michael M. , Huber Gerd
Published: February 2015

The anatomy of the facet joint subchondral mineralized zone (SMZ) is the main parameter used in diagnosing osteoarthritis. Usually, a single CT scan slice is used to measure the thickness, but the measurement is highly location‐dependent. Bone mineral density (BMD) and porosity could be more reliable than thickness for detecting SMZ sclerosis, and linking them to stiffness can provide insights into the mechanism of osteoarthritis progression. The goal of this study was two‐fold: (1) to assess spatial heterogeneity in thickness, BMD, and porosity within the non‐pathological human facet joint SMZ; (2) to correlate these measurements with the static modulus of elasticity (MOEsta). Four non‐pathological facet joints were excised and imaged using micro‐computed tomography (µCT) to measure SMZ thickness, BMD, and porosity. A total of eight parallelepiped SMZ samples were similarly analyzed and then mechanically tested. The mean SMZ BMD, porosity, and thickness (± Standard Deviation) of the whole facet joints were 611 ± 35 mgHA/cc, 9.8 ± 1.3%, and 1.39 ± 0.41 mm, respectively. The mean BMD, porosity, and MOEsta of the eight SMZ samples were 479 ± 23 mgHA/cc, 12 ± 0.01%, and 387 ± 138 MPa, respectively, with a positive rank correlation between BMD and porosity. BMD and porosity were more homogeneous within the facet joint than thickness and they could be more reliable parameters than thickness for detecting SMZ sclerosis. The values for the physiological SMZ and MOEsta of human facets joints obtained here were independent of BMD. SMZ BMD and porosity were related to each other. Clin. Anat. 28:538–544, 2015. © 2015 Wiley Periodicals, Inc.
Evidence for the Formation of an Enamine Species during Aldol and Michael‐type Addition Reactions Promiscuously Catalyzed by 4‐Oxalocrotonate Tautomerase
Authors: Poddar Harshwardhan , Rahimi Mehran , Geertsema Edzard M. , Thunnissen Andy‐Mark W. H. , Poelarends Gerrit J.
Published: February 2015

The enzyme 4‐oxalocrotonate tautomerase (4‐OT), which has a catalytic N‐terminal proline residue (Pro1), can promiscuously catalyze various carbon–carbon bond‐forming reactions, including aldol condensation of acetaldehyde with benzaldehyde to yield cinnamaldehyde, and Michael‐type addition of acetaldehyde to a wide variety of nitroalkenes to yield valuable γ‐nitroaldehydes. To gain insight into how 4‐OT catalyzes these unnatural reactions, we carried out exchange studies in D2O, and X‐ray crystallography studies. The former established that H–D exchange within acetaldehyde is catalyzed by 4‐OT and that the Pro1 residue is crucial for this activity. The latter showed that Pro1 of 4‐OT had reacted with acetaldehyde to give an enamine species. These results provide evidence of the mechanism of the 4‐OT‐catalyzed aldol and Michael‐type addition reactions in which acetaldehyde is activated for nucleophilic addition by Pro1‐dependent formation of an enamine intermediate.
Role of Vanadium and Phosphorus in Substituted Keggin‐Type Heteropolyoxo Molybdates Supported on Silica SBA‐15 in Selective Propene Oxidation
Authors: Zubrzycki Rafael , Epping Jan Dirk , Ressler Thorsten
Published: February 2015

Vanadium‐containing Keggin‐type heteropolyoxo molybdate ([PV2Mo10O40]5−) was supported on silica SBA‐15 (denoted as PV2Mo10‐SBA‐15). The structural evolution and catalytic activity of PV2Mo10‐SBA‐15 and a suitable reference V2Mo10Ox‐SBA‐15 were investigated under selective propene oxidation conditions by using in situ X‐ray absorption spectroscopy. 31P MAS NMR measurements of supported PV2Mo10‐SBA‐15 and reference H3PO4‐SBA‐15 were performed after the catalytic reaction. PV2Mo10‐SBA‐15 formed a mixture of mainly tetrahedral [MoOx] and [VOx] units during thermal treatment under propene oxidation conditions. Changes in the average local structure around V centers coincided with the changes in the average local structure around Mo centers and the onset of catalytic activity. In addition, mainly tetrahedral [MoOx] and [VOx] units seemed to be in close proximity and interacted under catalytic conditions. Conversely, in the reference material V2Mo10Ox‐SBA‐15 synthesized with individual V and Mo source precursors, Mo and V centers appeared to be more separated from each other. The structural environment of P in PV2Mo10‐SBA‐15 under catalytic conditions corresponded to a mixture of various species. P was connected to both the support material SBA‐15 via POSi bonds and [MoOx] or [VOx] units. Apparently, the proximity of V and Mo in Keggin precursors was a prerequisite for obtaining (Mo,V) oxide species on the support material.
Fluoro‐ and Perfluoralkylsulfonylpentafluoroanilides: Synthesis and Characterization of NH Acids for Weakly Coordinating Anions and Their Gas‐Phase and Solution Acidities
Authors: Kögel Julius F. , Linder Thomas , Schröder Fabian G. , Sundermeyer Jörg , Goll Sascha K. , Himmel Daniel , Krossing Ingo , Kütt Karl , Saame Jaan , Leito Ivo
Published: February 2015

Fluoro‐ and perfluoralkylsulfonyl pentafluoroanilides [HN(C6F5)(SO2X); X=F, CF3, C4F9, C8F17] are a class of imides with two different strongly electron‐withdrawing substituents attached to a nitrogen atom. They are NH acids, the unsymmetrical hybrids of the well‐known symmetrical bissulfonylimides and bispentafluorophenylamine. The syntheses, the structures of these perfluoroanilides, their solvates, and some selected lithium salts give rise to a structural variety beyond the symmetrical parent compounds. The acidities of representative subsets of these novel NH acids have been investigated experimentally and quantum‐chemically and their gas‐phase acidities (GAs) are reported, as well as the pKa values of these compounds in acetonitrile (MeCN) and DMSO solution. In quantum chemical investigations with the vertical and relaxed COSMO cluster‐continuum models (vCCC/rCCC), the unusual situation is encountered that the DMSO‐solvated acid Me2SO–H‐N(SO2CF3)2, optimized in the gas phase (vCCC model), dissociates to Me2SO‐H+–N(SO2CF3)2− during structural relaxation and full optimization with the solvation model turned on (rCCC model). This proton transfer underlines the extremely high acidity of HN(SO2CF3)2. The importance of this effect is studied computationally in DMSO and MeCN solution. Usually this effect is less pronounced in MeCN and is of higher importance in the more basic solvent DMSO. Nevertheless, the neglect of the structural relaxation upon solvation causes typical changes in the computational pKa values of 1 to 4 orders of magnitude (4–20 kJ mol−1). The results provide evidence that the published experimental DMSO pKa value of HN(SO2CF3)2 should rather be interpreted as the pKa of a Me2SO‐H+–N(SO2CF3)2− contact ion pair.
Automated Synthesis of Arabinoxylan‐Oligosaccharides Enables Characterization of Antibodies that Recognize Plant Cell Wall Glycans
Authors: Schmidt Deborah , Schuhmacher Frank , Geissner Andreas , Seeberger Peter H. , Pfrengle Fabian
Published: February 2015

Monoclonal antibodies that recognize plant cell wall glycans are used for high‐resolution imaging, providing important information about the structure and function of cell wall polysaccharides. To characterize the binding epitopes of these powerful molecular probes a library of eleven plant arabinoxylan oligosaccharides was produced by automated solid‐phase synthesis. Modular assembly of oligoarabinoxylans from few building blocks was enabled by adding (2‐naphthyl)methyl (Nap) to the toolbox of orthogonal protecting groups for solid‐phase synthesis. Conjugation‐ready oligosaccharides were obtained and the binding specificities of xylan‐directed antibodies were determined on microarrays.
Chiral Discrimination by Ionic Liquids: Impact of Ionic Solutes
Authors: Brown Christopher J. , Hopkins Todd A.
Published: February 2015

Chiral ionic liquids hold promise in many asymmetric applications. This study explores the impact of ionic solutes on the chiral discrimination of five amino acid methyl ester‐based ionic liquids, including L‐ and D‐alanine methyl ester, L‐proline methyl ester, L‐leucine methyl ester, and L‐valine methyl ester cations combined with bis(trifluoromethanesulfonimide) anion. Circularly polarized luminescence spectroscopy was used to study the chiral discrimination by measuring the racemization equilibrium of a dissymmetric europium complex, Eu(dpa)33− (where dpa = 2,6‐pyridinedicarboxylate). The chiral discrimination measured was dependent on the concentration of Eu(dpa)33− and this concentration‐dependence was different in each of the ionic liquids. Ionic liquids with L‐leucine methyl ester and L‐valine methyl ester even switched enantiomeric preference based on the solute concentration. Changing the cation of the Eu(dpa)33− salt from tetrabutylammonium to tetramethylammonium ion also affected the chiral discrimination demonstrated by the ionic liquids. Chirality 27:320–325, 2015. © 2015 Wiley Periodicals, Inc.
Theoretical Modeling of Surface Confined Chiral Nanoporous Networks: Cruciform Molecules as Versatile Building Blocks
Authors: Kasperski Adam , Szabelski Paweł
Published: February 2015

Patterning of solid surfaces with functional organic molecules has been a convenient route to fabricate two‐dimensional materials with programmed architecture and activities. One example is the chiral nanoporous networks that can be created via controlled self‐assembly of star‐shaped molecules under 2D confinement. In this contribution we use computer modeling to predict the formation of molecular networks in adsorbed overlayers comprising cruciform molecular building blocks equipped with discrete interaction centers. To that end, we employ the Monte Carlo simulation method combined with a coarse‐grained representation of the adsorbed molecules which are treated as collections of interconnected segments. The interaction centers within the molecules are represented by active segments whose number and distribution are adjusted. Our particular focus is on those distributions that produce prochiral molecules able to occur in adsorbed configurations being mirror images of each other (surface enantiomers). We demonstrate that, depending on size, aspect ratio, and intramolecular distribution of active sites, the surface enantiomers can co‐crystallize or segregate into extended homochiral domains with largely diversified nanosized cavities. The insights from our theoretical studies can be helpful in designing 2D chiral porous networks with potential applications in enantioselective adsorption and asymmetric heterogeneous catalysis. Chirality 27:397–404, 2015. © 2015 Wiley Periodicals, Inc.
Dynamical analysis of a delayed six‐neuron BAM network
Authors: Huang Chengdai , Li Ning , Cao Jinde , Hayat Tasawar
Published: February 2015

In this article, a simplified bidirectional associative memory network with delays involving six neurons is considered. By analyzing the distribution of roots of the characteristic equation for linearized system regarding the sum of delay as a bifurcation parameter, we obtain the condition of the occurrence for Hopf bifurcation. It reveals that Hopf bifurcation occurs when the sum of the delay passes through a critical value. The direction and the stability of the bifurcating periodic solution are determined by applying the normal form theory and center manifold theorem. Finally, a numerical example is used to illustrate the validity of theoretical results obtained. © 2015 Wiley Periodicals, Inc. Complexity 21: 9–28, 2016
Robust stability results for nonlinear Markovian jump systems with mode‐dependent time‐varying delays and randomly occurring uncertainties
Authors: Krishnasamy Ramasamy , Balasubramaniam Pagavathigounder
Published: February 2015

This article is concerned with the robust stability analysis for Markovian jump systems with mode‐dependent time‐varying delays and randomly occurring uncertainties. Sufficient delay‐dependent stability results are derived with the help of stability theory and linear matrix inequality technique using direct delay‐decomposition approach. Here, the delay interval is decomposed into two subintervals using the tuning parameter η such that
, and the sufficient stability conditions are derived for each subintervals. Further, the parameter uncertainties are assumed to be occurring in a random manner. Numerical examples are given to validate the derived theoretical results. © 2015 Wiley Periodicals, Inc. Complexity 21: 50–60, 2016
Distribution of human response times
Authors: Ma Tao , Holden John G. , Serota R. A.
Published: February 2015

We confirm that distributions of human response times have power‐law tails and argue that, among closed‐form distributions, the generalized inverse gamma distribution is the most plausible choice for their description. We speculate that the task difficulty tracks the half‐width of the distribution and show that it is related to the exponent of the power‐law tail. © 2015 Wiley Periodicals, Inc. Complexity 21: 61–69, 2016
Facile Synthesis and Enhanced Visible‐Light Photocatalysis of Graphitic Carbon Nitride Composite Semiconductors
Authors: Li Huiquan , Liu Yuxing , Gao Xing , Fu Cong , Wang Xinchen
Published: February 2015

The semiconductor heterojunction has been an effective architecture to enhance photocatalytic activity by promoting photogenerated charge separation. Here, graphitic carbon nitride (CN) and B‐modified graphitic carbon nitride (CNB) composite semiconductors were fabricated by a facile calcination process using cheap, sustainable, and easily available sodium tetraphenylboron and urea as precursors. The synthetic CN‐CNB‐25 semiconductor with a suitable CNB content showed the highest visible‐light activity. Its degradation ratio for methyl orange and phenol was more than twice that of CN and CNB and its H2 evolution rate was ∼3.4 and ∼1.8 times higher than that of CN and CNB, respectively. It also displayed excellent stability and reusability. The enhanced activity of CN‐CNB‐25 was attributed predominantly to the efficient separation of photoinduced electrons and holes. This paper describes a visible‐light‐responsive CN composite semiconductor with great potential in environmental and energy applications.
Screening method for stimulants in urine by UHPLC‐MS/MS: identification of isomeric compounds
Authors: Monfort Núria , Martínez Laura , Bergés Rosa , Segura Jordi , Ventura Rosa
Published: February 2015

A fast screening method for the detection of more than 60 stimulants in urine was developed. The method consisted of a dilution of the urine (1:5 v/v) and analysis by ultra high performance liquid chromatography coupled to tandem mass spectrometry, using a C18 column (1.7 µm particle size), a mobile phase containing deionized water and acetonitrile with formic acid, and gradient elution. The chromatographic run time was 5 min. The detection was performed in positive mode electrospray ionization, monitoring one or two specific ion transitions for each analyte. Appropriate repeatability was obtained, with relative standard deviation (RSD) values below 25% for most of the analytes. Regarding intermediate precision, estimated during routine work, higher RSDs were obtained, probably due to between‐day differences in the status of the mass spectrometer and in the chromatographic system. Matrix effect ranged from 60 to 255% with RSD lower than 35% for the majority of compounds. Despite the matrix effect observed, the signal/noise ratio of the analytes spiked at 50 ng/mL was greater than three in all tested samples, allowing a correct detection of all substances at the minimum required performance levels required by the World Anti‐Doping Agency and demonstrating the suitability of the method. The method was tested in administration study samples and satisfactorily in operation for more than one year with routine doping samples. The presence of isomeric stimulants with closely similar chromatographic and/or mass spectrometric properties did not allow the unequivocal identification of these compounds after the first analysis. Different possibilities for separation and identification of isomeric compounds are presented. Copyright © 2015 John Wiley & Sons, Ltd.
Postcombustion CO2 capture using N‐(3‐trimethoxysilylpropyl)diethylenetriamine‐grafted solid adsorbent
Authors: Mittal Nikhil , Samanta Arunkumar , Sarkar Partha , Gupta Rajender
Published: February 2015

In this work, the performance of N‐(3‐trimethoxysilylpropyl)diethylenetriamine (DAEAPTS)‐grafted mesoporous SBA‐15 adsorbent for postcombustion carbon capture was studied. Wet grafting technique was adopted to functionalize SBA‐15 surface. The adsorption of CO2 on the amine‐grafted sorbent was measured by the thermogravimetric method over a CO2 partial pressure range of 0–90 kPa and a temperature range of 25–105°C under atmospheric pressure. The optimal amine loaded SBA‐15 adsorbent containing 40 wt% DAEAPTS exhibited capture capacity up to 2.3 mmol/g under simulated gas conditions (88.2% CO2/N2) at 75°C. The CO2 adsorption–desorption kinetics of the grafted sorbents were found to be sufficiently fast in both dry and humid CO2 streams and it was observed that the grafted adsorbent achieved 75% of the total capacity in 5 min of adsorption time in dry 8.8% CO2/N2 and in less than 3.5 min in humid 8.8% CO2/N2. It was also observed that 95% of the total desorption occurred in less than 7 min at 150°C under pure N2. The grafted sorbents showed good reversibility and multicycle stability and the drop in capacity after 100 cycles in dry and humid 8.8% CO2/N2 streams was around 7.09% and 11.65%, respectively.
A high‐resolution hybrid scheme for hyperbolic conservation laws
Authors: Xiaoshuai Wu , Yuxin Zhao
Published: February 2015

A new hybrid scheme is proposed, which combines the improved third‐order weighted essentially non‐oscillatory (WENO) scheme presented in this paper with a fourth‐order central scheme by a novel switch. Two major steps have been gone through for the construction of a high‐performance and stable hybrid scheme. Firstly, to enhance the WENO part of the hybrid scheme, a new reference smoothness indicator has been devised, which, combined with the nonlinear weighting procedure of WENO‐Z, can drive the third‐order WENO toward the optimal linear scheme faster. Secondly, to improve the hybridization with the central scheme, a hyperbolic tangent hybridization switch and its efficient polynomial counterpart are devised, with which we are able to fix the threshold value introduced by the hybridization. The new hybrid scheme is thus formulated, and a set of benchmark problems have been tested to verify the performance enhancement. Numerical results demonstrate that the new hybrid scheme achieves excellent performance in resolving complex flow features, even compared with the fifth‐order classical WENO scheme and WENO‐Z scheme. Copyright © 2015 John Wiley & Sons, Ltd.
A prospective study of positron emission tomography for evaluation of neck node response 6 weeks after radiotherapy in patients with head and neck squamous cell carcinoma
Authors: Sjövall Johanna , Wahlberg Peter , Almquist Helen , Kjellén Elisabeth , Brun Eva
Published: February 2015

Background

The purpose of this study was to evaluate if a positron emission tomography (PET) scan, 6 weeks after radiotherapy (RT), adequately selects patients in whom a neck node dissection can be omitted. Primary endpoints were isolated neck recurrences and overall survival (OS).

Methods

One hundred five patients, mainly with oropharyngeal human papillomavirus (HPV)‐positive tumors, with a positive PET scan before treatment, were evaluated regarding the neck response 6 weeks post‐RT. The PET results determined the management of the neck: observation versus neck dissection.

Results

Median follow‐up was 25 months. Positive predictive value (PPV) and negative predictive value (NPV) were 56% and 94%, respectively. Four isolated neck recurrences occurred. The 2‐year OS rate was 86.3%.

Conclusion

PET scans performed 6 weeks after RT have a high NPV and can obviate neck dissections but the PPV is insufficient. A later scheduled scan is recommended. © 2015 Wiley Periodicals © 2015 Wiley Periodicals, Inc. Head Neck 38: E473–E479, 2016
Targeted pharmacotherapy in progressive familial intrahepatic cholestasis type 2: Evidence for improvement of cholestasis with 4‐phenylbutyrate
Authors: Gonzales Emmanuel , Grosse Brigitte , Schuller Brice , Davit‐Spraul Anne , Conti Filomena , Guettier Catherine , Cassio Doris , Jacquemin Emmanuel
Published: February 2015

Progressive familial intrahepatic cholestasis type 2 (PFIC2) is a result of mutations in ABCB11 encoding bile salt export pump (BSEP), the canalicular bile salt export pump of hepatocyte. In some PFIC2 patients with missense mutations, BSEP is not detected at the canaliculus owing to mistrafficking of BSEP mutants. In vitro, chaperone drugs, such as 4‐phenylbutyrate (4‐PB), have been shown to partially correct mistrafficking. Four PFIC2 patients harboring at least one missense mutation (p.G982R, p.R1128C, and p.T1210P) were treated orally with 4‐PB and followed prospectively. Patient mutations were reproduced in a Bsep/green fluorescent protein plasmid. Cellular localization of the resulting Bsep mutants was studied in a hepatocellular line (Can 10), and effects of treatment with 4‐PB and/or ursodeoxycholic acid (UDCA) were assessed. In Can 10 cells, Bsep mutants were detected in the endoplasmic reticulum instead of at the canalicular membrane. Treatment with 4‐PB and UDCA partially corrected Bsep mutant targeting. With 4‐PB, we observed, in all patients, a decrease of pruritus and serum bile acid concentration (BAC) as well as an improvement of serum liver tests. Pathological liver injuries improved, and BSEP, which was not detected at the canalicular membrane before treatment, appeared at the canalicular membrane. Bile analyses showed an increase in BAC with 4‐PB. Patient conditions remained stable with a median follow‐up of 40 months (range, 3‐53), and treatment tolerance was good. Conclusion: 4‐PB therapy may be efficient in selected patients with PFIC2 owing to ABCB11 missense mutations affecting BSEP canalicular targeting. Bile secretion improvement may be a result of the ability of 4‐PB to retarget mutated BSEP. (Hepatology 2015) Hepatology 2015;62:558–566
Multicenter experience using simeprevir and sofosbuvir with or without ribavirin to treat hepatitis C genotype 1 after liver transplant
Authors: Pungpapong Surakit , Aqel Bashar , Leise Michael , Werner K. Tuesday , Murphy Jennifer L. , Henry Tanisha M. , Ryland Kristen , Chervenak Amy E. , Watt Kymberly D. , Vargas Hugo E. , Keaveny Andrew P.
Published: February 2015

Treatment with an all‐oral interferon‐free antiviral regimen using simeprevir and sofosbuvir with or without ribavirin (RBV) for 12 weeks resulted in high sustained virologic response (SVR) rates along with minimal adverse events in non–liver transplant (LT) patients with hepatitis C virus (HCV) genotype 1 infection. This is the first multicenter report on the efficacy, safety, and tolerability of this regimen in LT recipients. A total of 123 patients (76% male, 74% white, 60% genotype 1a, 30% METAVIR F3‐F4, 4% decompensation, 11% cholestatic recurrence, 7% had kidney transplant, and 82% previously failed pegylated interferon/RBV‐based regimens) received treatment and were followed for a median of 30 weeks (range 12‐53 weeks). The median time from LT to treatment was 32 months (range 2‐317 months). Tacrolimus was the primary immunosuppression in 91% of patients. Minimal immunosuppression dose adjustments were required. An SVR 12 weeks after treatment completion (SVR12) was achieved in 90% of patients (95% confidence interval 84%‐96%). In patients with genotype 1a infection, the SVR12 rate was significantly lower in those with METAVIR F3‐F4 (71%) compared to those with F0‐F2 (91%). Half of the patients achieved undetected HCV RNA at treatment week 4, and their SVR12 rate was significantly higher (96%) compared to those with detectable HCV RNA (83%). Treatment was very well tolerated with mild degrees of adverse events, except for one death possibly due to drug‐induced lung injury. In the 25 patients who received RBV, 72% developed anemia requiring intervention. Conclusion: An all‐oral interferon‐free antiviral regimen using simeprevir and sofosbuvir with or without RBV for 12 weeks was very well tolerated and resulted in excellent SVR12 rates in LT recipients with HCV genotype 1 infection. (Hepatology 2015;61:1880–1886)
Toward the measurement of multiple fluorescence lifetimes in flow cytometry: maximizing multi‐harmonic content from cells and microspheres
Authors: Jenkins Patrick , Naivar Mark A. , Houston Jessica P.
Published: February 2015

Flow cytometry is a powerful means for in vitro cellular analyses where multi‐fluorescence and multi‐angle light scattering can indicate unique biochemical or morphological features of single cells. Yet, to date, flow cytometry systems have lacked the ability to capture complex fluorescence dynamics due to the transient nature of flowing cells. In this contribution we introduce a simple approach for measuring multiple fluorescence lifetimes from a single cytometric event. We leverage square wave modulation, Fourier analysis, and high frequency digitization and show the ability to resolve more than one fluorescence lifetime from fluorescently‐labelled cells and microspheres.

Illustration of a flow cytometer capable of capturing multiple fluorescence lifetime measurements; creating potential for multi‐parametric, time‐resolved signals to be captured for every color channel.

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Illustration of a flow cytometer capable of capturing multiple fluorescence lifetime measurements; creating potential for multi‐parametric, time‐resolved signals to be captured for every color channel.
Detecting concentrations of milk components by an iterative optical technique
Authors: Yariv Inbar , Kapp‐Barnea Yaara , Genzel Eran , Duadi Hamootal , Fixler Dror
Published: February 2015

This paper introduces a theoretical and practical model for reconstructing the scattering properties of a participating media. Our theory is based on a robust generalization of the Gerchberg–Saxton (G–S) algorithm. At the end of this algorithm the reduced scattering coefficient μ′s of a given substance, can be estimated from the standard deviation (STD) of the retrieved phase of the remitted light. We use the theory to compute the phase's STD that directly correlated to the optical properties for different types of milk components, and we derive a novel appearance model for milk parameterized by the lactose and protein contents. Our results show that we are able to detect the possibility of lactose and milk proteins' quantitative signature by the G–S optical tool, en route to the design of a novel milk‐content‐monitoring tool.

Sketch of the experimental setup for light intensity measurements and reduced scattering coefficient reconstruction. The samples were prepared from various milk components: whey protein, sodium casienate and lactose, at different concentrations.

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Sketch of the experimental setup for light intensity measurements and reduced scattering coefficient reconstruction. The samples were prepared from various milk components: whey protein, sodium casienate and lactose, at different concentrations.