bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polarized reflectance factors of vegetation covers from laboratory and field: A comparison with modeled results
Authors: Sun Zhongqiu , Wu Di , Lv Yunfeng , Zhao Yunsheng 
Published: December 2016

AbstractLight scattered from surfaces is partly polarized, which has implications for remote sensing of vegetation. To study the contribution of polarized light to multiangular reflectance over vegetation covers, we produced a hyperspectral bidirectional polarized reflectance data set for four types of vegetation cover acquired over a wide‐viewing range in the laboratory and field. The data sets were analyzed with respect to basic physical polarized reflectance mechanisms. Moreover, we compared the modeled polarization from five existing polarimetric models (1‐D) with our measured polarization of vegetation covers at selected wavelengths. The analyses indicated that our measured polarized reflectance factors of a special vegetation cover, in which the leaves of vegetation were horizontally oriented, were much greater than previous results. All of the models produced good fits to the measurements, except for the special vegetation cover, which leaded to markedly different distribution patterns for the five models. We also found that the maximum relative difference between modeled and measured polarization was in the backward scattering direction near the principal plane. These results suggested that we can model the polarization accurately by using the existing polarimetric models in visible and near‐infrared bands; more measurements should be performed in the laboratory and the field to illustrate the inherent polarization property of vegetation covers and to avoid underestimating the contribution of vegetation covers on the polarization of atmosphere in the polarized remote sensing study. Our study not only deepens our understanding of the scattering properties of vegetation covers but also provides the polarization properties of vegetated surfaces for the study of atmosphere polarization.
Entrainment of stratospheric air and Asian pollution by the convective boundary layer in the southwestern U.S.
Authors: Langford A. O. , Alvarez R. J. , Brioude J. , Fine R. , Gustin M. S , Lin M. Y. , Marchbanks R. D. , Pierce R. B. , Sandberg S. P. , Senff C. J. , Weickmann A. M. , Williams E. J. 
Published: December 2016

AbstractA series of deep stratospheric intrusions in late May 2013 increased the daily maximum 8 h surface ozone (O3) concentrations to more than 70 parts per billion by volume (ppbv) at rural and urban surface monitors in California and Nevada. This influx of ozone‐rich lower stratospheric air and entrained Asian pollution persisted for more than 5 days and contributed to exceedances of the 2008 8 h national ambient air quality standard of 75 ppbv on 21 and 25 May in Clark County, NV. Exceedances would also have occurred on 22 and 23 May had the new standard of 70 ppbv been in effect. In this paper, we examine this episode using lidar measurements from a high‐elevation site on Angel Peak, NV, and surface measurements from NOAA, the Clark County, Nevada Department of Air Quality, the Environmental Protection Agency Air Quality System, and the Nevada Rural Ozone Initiative. These measurements, together with analyses from the National Centers for Environmental Prediction/North American Regional Reanalysis; NOAA Geophysical Fluid Dynamics Laboratory AM3 model; NOAA National Environmental Satellite, Data, and Information Service Real‐time Air Quality Modeling System; and FLEXPART models, show that the exceedances followed entrainment of ~20 to 40 ppbv of lower stratospheric ozone mingled with another 0 to 10 ppbv of ozone transported from Asia by the unusually deep convective boundary layers above the Mojave desert. Our analysis suggests that this vigorous mixing can affect both high and low elevations and help explain the springtime ozone maximum in the southwestern U.S.
A tale of two poles: Toward understanding the presence, distribution, and origin of volatiles at the polar regions of the Moon and Mercury
Authors: Lawrence David J. 
Published: December 2016

AbstractThe Moon and Mercury both have permanently shaded regions (PSRs) at their poles, which are locations that do not see the Sun for geologically long periods of time. The PSRs of the Moon and Mercury have very cold temperatures (<120 K) and as a consequence act as traps for volatile materials. Volatile enhancements have been detected and characterized at both planetary bodies, but the volatile concentrations at Mercury's poles are significantly larger than at the Moon's poles. This paper documents the study of PSR volatiles at the Moon and Mercury that has taken place over the past 60 years. Starting with speculative ideas in the 1950s and 1960s, the field of PSR volatiles has emerged into a thriving subfield of planetary science that has significant implications for scientific studies of the solar system, as well as future human exploration of the solar system. While much has been learned about PSRs and PSR volatiles, many foundational aspects of PSRs are still not understood. One of the most important unanswered questions is why the PSR volatile concentrations at the Moon and Mercury are so different. After describing the initial predictions and measurements of PSR volatiles, this paper documents a variety of PSR measurements, summarizes the current understanding of PSR volatiles, and then suggests what new measurements and studies are needed to answer many of the remaining open questions about PSR volatiles.
Adapting a climatology model to improve estimation of ionosphere parameters and subsequent validation with radio occultation and ionosonde data
Authors: Habarulema John Bosco , Ssessanga Nicholas 
Published: December 2016

AbstractThis paper reports on the adaptation and modification of a climatological model, the International Reference Ionosphere (IRI 2012 model) with the use of total electron content (TEC) data derived from the Global Navigation Satellite System (GNSS), and most importantly its subsequent validation with both radio occultation from Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) and ionosonde data. By adjusting the solar activity indices used within the standard IRI 2012 model with the aim of minimizing error differences between IRI TEC and GNSS TEC, the adjusted indices are used as drivers of the IRI 2012 model on a regional scale and results for electron density (Ne) profiles, maximum height of the F2 layer (hmF2), TEC, and critical frequency of the F2 layer (foF2) generated. Validation was done by direct comparison with ionosonde and COSMIC‐derived data parameters. By averaging results over low, equatorial, and midlatitude regions, the modified IRI 2012 gave an improvement of about 18% in estimating TEC during the storm period of 9 March 2012. An important result observed during our candidate period of study is that COSMIC data provides maximum electron density of the F2 layer (NmF2) and hmF2 closer to ionosonde data even during the disturbed period and is hence a suitable data set that can be incorporated into the climatological IRI model to improve its performance. The Ne profiles from the modified IRI 2012 model accurately approximates ionosonde Ne profiles especially below 300 km altitude but underestimates the ionosonde NmF2 and hence foF2 in midlatitude regions. In most cases both standard and modified IRI 2012 models match COSMIC data for topside electron density representation, making the COSMIC data set a valuable resource for the improvement of ionospheric climatological models.
Superoxide Radical Anion‐Mediated Aerobic Oxidative Synthesis of 2‐Substituted Quinazolines under Visible Light
Authors: Yang Xiu‐Long , Meng Qing‐Yuan , Gao Xue‐Wang , Lei Tao , Wu Cheng‐Juan , Chen Bin , Tung Chen‐Ho , Wu Li‐Zhu 
Published: December 2016

AbstractA facile and efficient one‐pot reaction for the aerobic oxidative synthesis of 2‐substituted quinazolines using visible‐light catalysis has been developed. A variety of substituted aldehydes and 2‐aminobenzylamines are amenable to producing the corresponding quinazolines in good to excellent yields under metal‐free conditions. Electron paramagnetic resonance (EPR) measurements provide clear evidence on the formation of a superoxide radical anion (O2⋅−), which is responsible for this transformation.
Channeling Exciton Migration into Electron Transfer in Formamidinium Lead Bromide Perovskite Nanocrystal/Fullerene Composites
Authors: Nair Vijayakumar C. , Muthu Chinnadurai , Rogach Andrey L. , Kohara Reiko , Biju Vasudevanpillai 
Published: December 2016

AbstractHydrophobically capped nanocrystals of formamidinium lead bromide (FAPbBr3) perovskite (PNC) show bright and stable fluorescence in solution and thin‐film states. When compared with isolated PNCs in a solution, close‐packed PNCs in a thin film show extended fluorescence lifetime (ca. 4.2 μs), which is due to hopping or migration of photogenerated excitons among PNCs. Both fluorescence quantum efficiency and lifetime decrease in a PNC thin film doped with fullerene (C60), which is attributed to channeling of exciton migration into electron transfer to C60. On the other hand, quenching of fluorescence intensity of a PNC solution is not accompanied by any change in fluorescence lifetime, indicating static electron transfer to C60 adsorbed onto the hydrophobic surface of individual PNCs. Exciton migration among close‐packed PNCs and electron transfer to C60 places C60‐doped PNC thin films among cost‐effective antenna systems for solar cells.
Separating Dipolar and Chemical Exchange Magnetization Transfer Processes in 1H‐CEST
Authors: Yuwen Tairan , Sekhar Ashok , Kay Lewis E. 
Published: December 2016

AbstractAn amide 1H‐Chemical Exchange Saturation Transfer (CEST) experiment is presented for studies of conformational exchange in proteins. The approach, exploiting spin‐state‐selective magnetization transfer, completely suppresses undesired NOE‐based dips in CEST profiles so that chemical exchange processes can be studied. The methodology is demonstrated with applications involving proteins that interconvert on the millisecond timescale between major and invisible minor states, and accurate amide 1H chemical shifts of the minor conformer are obtained in each case. The spin‐state‐selective magnetization transfer approach offers unique possibilities for quantitative studies of protein exchange through 1H‐CEST.
Quantitative electron tomography of PLA/clay nanocomposites to understand the effect of the clays in the thermal stability
Authors: Iturrondobeitia Maider , Guraya Teresa , Okariz Ana , Srot Vesna , van Aken Peter A. , Ibarretxe Julen 
Published: December 2016

ABSTRACTPoly(lactic acid) (PLA) is one of the most promising bio‐based and biodegradable polymers. However, its processability and range of applications are limited by its low thermal stability. The novelty of this work is studying the thermal stability of two PLA/clay nanocomposites (PLA/Cloisite 20A and PLA/Cloisite 30B) as a function of the composition and the microstructure, which is exhaustively studied by performing quantitative electron tomography (ET). Quantitative ET involves image acquisition, reconstruction of the volume and a subsequent segmentation of the objects under study. In this work, an objective segmentation is applied to compare the two PLA/clay microstructures. Then, relevant descriptors of the 3D microstructure (dimensions of the reconstructed objects, their specific surface area and orientation) are measured and used to quantitatively explain the effect of the clay particles on the thermal stability of the nanocomposites. The tortuous path has been calculated—based on the descriptors of the microsturecture—and proved to be larger for PLA/Cloisite 30B nanocomposite compared to that of PLA/Cloisite 20A. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44691.
Evaluation of the Electronic Structure of Single‐Molecule Junctions Based on Current–Voltage and Thermopower Measurements: Application to C60 Single‐Molecule Junction
Authors: Komoto Yuki , Isshiki Yuji , Fujii Shintaro , Nishino Tomoaki , Kiguchi Manabu 
Published: December 2016

AbstractThe electronic structure of molecular junctions has a significant impact on their transport properties. Despite the decisive role of the electronic structure, a complete characterization of the electronic structure remains a challenge. This is because there is no straightforward way of measuring electron spectroscopy for an individual molecule trapped in a nanoscale gap between two metal electrodes. Herein, a comprehensive approach to obtain a detailed description of the electronic structure in single‐molecule junctions based on the analysis of current–voltage (I–V) and thermoelectric characteristics is described. It is shown that the electronic structure of the prototypical C60 single‐molecule junction can be resolved by analyzing complementary results of the I–V and thermoelectric measurement. This combined approach confirmed that the C60 single‐molecule junction was highly conductive with molecular electronic conductances of 0.033 and 0.003 G0 and a molecular Seebeck coefficient of −12 μV K−1. In addition, we revealed that charge transport was mediated by a LUMO whose energy level was located 0.5≈0.6 eV above the Fermi level of the Au electrode.
Acceleration of protein backbone NMR assignment by combinatorial labeling: Application to a small molecule binding study
Authors: Hein Christopher , Löhr Frank , Schwarz Daniel , Dötsch Volker 
Published: December 2016

AbstractSelective labeling with stable isotopes has long been recognized as a valuable tool in protein NMR to alleviate signal overlap and sensitivity limitations. In this study, combinatorial 15N‐, 13Cα‐, and 13C'‐selective labeling has been used during the backbone assignment of human cyclophilin D to explore binding of an inhibitor molecule. Using a cell‐free expression system, a scheme that involves 15N, 1‐13C, 2‐13C, fully 15N/13C, and unlabeled amino acids was optimized to gain a maximum of assignment information from three samples. This scheme was combined with time‐shared triple‐resonance NMR experiments, which allows a fast and efficient backbone assignment by giving the unambiguous assignment of unique amino acid pairs in the protein, the identity of ambiguous pairs and information about all 19 non‐proline amino acid types. It is therefore well suited for binding studies where de novo assignments of amide 1H and 15N resonances need to be obtained, even in cases where sensitivity is the limiting factor.
A novel serum microRNA signature to screen esophageal squamous cell carcinoma
Authors: Huang Zebo , Zhang Lan , Zhu Danxia , Shan Xia , Zhou Xin , Qi Lian‐wen , Wu Lirong , Zhu Jun , Cheng Wenfang , Zhang Huo , Chen Yan , Zhu Wei , Wang Tongshan , Liu Ping 
Published: December 2016

AbstractCirculating microRNAs (miRNAs) have been used as promising diagnostic biomarkers for esophageal squamous cell carcinoma (ESCC). We performed miRNA expression profiling using quantitative reverse transcription polymerase chain reaction (qRT‐PCR) based Exiqon panels from three ESCC pools and one normal control (NC) pool samples. Using qRT‐PCR, identified serum miRNAs were further confirmed in training (32 ESCC vs. 32 NCs) and testing stages (108 ESCC vs. 96 NCs). Consequently, five serum miRNAs (miR‐20b‐5p, miR‐28‐3p, miR‐192‐5p, miR‐223‐3p, and miR‐296‐5p) were significantly overexpressed in ESCC compared with NCs. The diagnostic value of the 5‐miRNA signature was validated by an external cohort (60 ESCC vs. 60 NCs). The areas under the receiver operating characteristic curve (ROC) of the 5‐miRNA signature were 0.753, 0.763, and 0.966 for the training, testing, and the external validation stages, respectively. The expression levels of the miRNAs were also determined in tissues, arterial serum, and exosomes. MiR‐20b‐5p, miR‐28‐3p, and miR‐192‐5p were significantly upregulated in ESCC tissues, while miR‐296‐5p was overexpressed in ESCC serum exosomes. In conclusion, we identified a 5‐miRNA signature in serum for the detection of ESCC.
TXNIP mediates the differential responses of A549 cells to sodium butyrate and sodium 4‐phenylbutyrate treatment
Authors: Jin Xuefang , Wu Nana , Dai Juji , Li Qiuxia , Xiao XiaoQiang 
Published: December 2016

AbstractSodium butyrate (NaBu) and sodium 4‐phenylbutyrate (4PBA) have promising futures in cancer treatment; however, their underlying molecular mechanisms are not clearly understood. Here, we show A549 cell death induced by NaBu and 4PBA are not the same. NaBu treatment induces a significantly higher level of A549 cell death than 4PBA. A gene expression microarray identified more than 5000 transcripts that were altered (>1.5‐fold) in NaBu‐treated A549 cells, but fewer than 2000 transcripts that were altered in 4PBA. Moreover, more than 100 cell cycle‐associated genes were greatly repressed by NaBu, but slightly repressed by 4PBA; few genes were significantly upregulated only in 4PBA‐treated cells. Gene expression was further validated by other experiments. Additionally, A549 cells that were treated with these showed changes in glucose consumption, caspase 3/7 activation and histone modifications, as well as enhanced mitochondrial superoxide production. TXNIP was strongly induced by NaBu (30‐ to 40‐fold mRNA) but was only slightly induced by 4PBA (two to fivefold) in A549 cells. TXNIP knockdown by shRNA in A549 cells significantly attenuated caspase 3/7 activation and restored cell viability, while TXNIP overexpression significantly increased caspase 3/7 activation and cell death only in NaBu‐treated cells. Moreover, TXNIP also regulated NaBu‐ but not 4PBA‐induced H4K5 acetylation and H3K4 trimethylation, possibly by increasing WDR5 expression. Finally, we demonstrated that 4PBA induced a mitochondrial superoxide‐associated cell death, while NaBu did so mainly through a TXNIP‐mediated pathway. The above data might benefit the future clinic application.
The role of TGF‐β1 during skeletal muscle regeneration
Authors: Delaney Kamila , Kasprzycka Paulina , Ciemerych Maria Anna , Zimowska Malgorzata 
Published: December 2016

AbstractThe injury of adult skeletal muscle initiates series of well‐coordinated events that lead to the efficient repair of the damaged tissue. Any disturbances during muscle myolysis or reconstruction may result in the unsuccessful regeneration, characterised by strong inflammatory response and formation of connective tissue, that is, fibrosis. The switch between proper regeneration of skeletal muscle and development of fibrosis is controlled by various factors. Amongst them are those belonging to the transforming growth factor β family. One of the TGF‐β family members is TGF‐β1, a multifunctional cytokine involved in the regulation of muscle repair via satellite cells activation, connective tissue formation, as well as regulation of the immune response intensity. Here, we present the role of TGF‐β1 in myogenic differentiation and muscle repair. The understanding of the mechanisms controlling these processes can contribute to the better understanding of skeletal muscle atrophy and diseases which consequence is fibrosis disrupting muscle function.
A Sustainable Heterogeneous Iron Catalyst Fe/SBA‐15 towards Direct Arylation of Unactivated C(sp3)−H and C(sp2)−H Bonds with Arenes
Authors: Rajendran C. , Satishkumar G. 
Published: December 2016

AbstractIron grafted over mesoporous silica (8 wt %Fe/SBA‐15) is a sustainable, efficient heterogeneous iron catalyst for direct arylation of biphenyl methane C(sp3)−H and benzene C(sp2)−H bonds. The selective extraction deposition (SED) technique was adopted to graft iron easily over the mesoporous support SBA‐15 by using LaFeO3 as an iron precursor. The synthesized catalyst has been characterized by EPR spectroscopy, diffuse reflectance UV/Vis spectroscopy, and temperature programmed reduction (TPR) analysis to understand the coordination environment and state of oxidic iron species grafted over the mesoporous SBA‐15. TPR results confirm the presence of isolated, clustered, oligomeric oxidic iron species in the catalyst. The adopted SED technique is highly successful for grafting 8 wt % iron into the mesopores of SBA‐15 without forming iron oxide particles. Unlike homogeneous iron, the 8 wt %Fe/SBA‐15 catalyst does not need support from an electron‐withdrawing group and additives to carry out arylation of benzene and could be successfully recycled five times.
Somatic and neuritic spines on tyrosine hydroxylase–immunopositive cells of rat retina
Authors: Fasoli Anna , Dang James , Johnson Jeffrey S. , Gouw Aaron H. , Fogli Iseppe Alex , Ishida Andrew T. 
Published: December 2016

AbstractDopamine‐ and tyrosine hydroxylase–immunopositive cells (TH cells) modulate visually driven signals as they flow through retinal photoreceptor, bipolar, and ganglion cells. Previous studies suggested that TH cells release dopamine from varicose axons arborizing in the inner and outer plexiform layers after glutamatergic synapses depolarize TH cell dendrites in the inner plexiform layer and these depolarizations propagate to the varicosities. Although it has been proposed that these excitatory synapses are formed onto appendages resembling dendritic spines, spines have not been found on TH cells of most species examined to date or on TH cell somata that release dopamine when exposed to glutamate receptor agonists. By use of protocols that preserve proximal retinal neuron morphology, we have examined the shape, distribution, and synapse‐related immunoreactivity of adult rat TH cells. We report here that TH cell somata, tapering and varicose inner plexiform layer neurites, and varicose outer plexiform layer neurites all bear spines, that some of these spines are immunopositive for glutamate receptor and postsynaptic density proteins (viz., GluR1, GluR4, NR1, PSD‐95, and PSD‐93), that TH cell somata and tapering neurites are also immunopositive for a γ‐aminobutyric acid (GABA) receptor subunit (GABAARα1), and that a synaptic ribbon‐specific protein (RIBEYE) is found adjacent to some colocalizations of GluR1 and TH in the inner plexiform layer. These results identify previously undescribed sites at which glutamatergic and GABAergic inputs may stimulate and inhibit dopamine release, especially at somata and along varicose neurites that emerge from these somata and arborize in various levels of the retina. J. Comp. Neurol. 525:1707–1730, 2017. © 2016 Wiley Periodicals, Inc.