bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of the successive planting of Eucalyptus urophylla on soil bacterial and fungal community structure, diversity, microbial biomass, and enzyme activity
Authors: Zhu Lingyue , Wang Xiuhai , Chen Fangfang , Li Chunhua , Wu Lichao 
Published: January 2019

AbstractEucalyptus are a widely used short‐rotation species for timber production in South China. There are growing concerns regarding the influences of successive planting of Eucalyptus urophylla on microorganisms and soil. The aim of this work was to determine the effects of the successive planting of E. urophylla on soil characteristics. Five different stands, including 5‐, 10‐, 15‐, and 18‐year‐old E. urophylla plantations (abbreviated as 5yr, 10yr, 15yr, and 18yr, respectively) and one native evergreen broadleaf forest as a 0‐year‐old E. urophylla plantation (abbreviated as CK) were used. All of measured chemical indicators, microbial biomass, and enzyme activities were significantly lower in E. urophylla plantations compared with CK stand. The microbial biomass and enzyme activities significantly decreased in 5yr stand, significantly increased in 10yr stand, and subsequently declined in 15yr and 18yr stands. The relative abundance of Ascomycota in 15yr (77.10%) and 18yr (72.71%) plantations was significantly higher than in other stands. Basidiomycota relative abundance in the E. urophylla plantations was significantly lower than in the CK stand. In addition, the bacterial diversity was significantly decreased in 15yr and 18yr stands, whereas the fungal diversity was the lowest in 5yr stand and significantly increased in 10yr, 15yr, and 18yr stands. Furthermore, structural equation modelling showed that successive planting of E. urophylla decreased the soil bacterial community diversity, microbial biomass, and enzyme activity but increased the fungal community diversity. Thus, successive planting of E. urophylla negatively influenced the soil bacterial diversity, microbial biomass, and enzyme activity and positively influenced soil fungal diversity.
Soil organic matter and texture estimation from visible–near infrared–shortwave infrared spectra in areas of land cover changes using correlated component regression
Authors: Rosero‐Vlasova Olga A. , Vlassova Lidia , Pérez‐Cabello Fernando , Montorio Raquel , Nadal‐Romero Estela 
Published: January 2019

AbstractLand use changes due to natural and human‐related factors, which include wildfires and crop abandonment, are among the most important drivers of soil degradation and demand regular monitoring. Proximal soil sensing in visible–near infrared–shortwave infrared spectral regions could offer a solution. However, to become operational, optimal combination of data and technique has to be defined. Thus, the purpose of this study was (a) to predict the soil organic matter (SOM) content and soil texture in areas of wildfire burns and crop abandonment in Aragón Province, Northern Spain, from their laboratory reflectance spectra using novel correlated components regression with a step‐down variable selection algorithm (CCR‐SD) and (b) to compare the CCR‐SD and the partial least squares regression (PLSR) methods. The results obtained by the tested methods were similar. CCR‐SD models showed high predictive capacity with coefficients of determination (R2) in the range of 0.80–0.86 and 0.70–0.87 for calibration and validation data sets, respectively, and the highest R2 value was attained in the SOM estimation. Moreover, the CCR‐SD models stand out for the superior accuracy–parsimony relationship: the number of predictors varied from 16 (silt models) to 49 (SOM models). On average, the CCR‐SD calibrations needed less than a half of the predictors employed in PLSR models. This research confirmed that CCR‐SD can be used for monitoring SOM content and texture of soils from visible–near infrared–shortwave infrared spectra in the study area and, probably, in other areas of land use/land cover change and that CCR‐SD can create highly parsimonious models that achieve results comparable with the commonly used PLSR method.
Ultrahigh‐Q Photonic Nanocavity Devices on a Dual Thickness SOI Substrate Operating at Both 1.31‐ and 1.55‐µm Telecommunication Wavelength Bands
Authors: Kuwabara Mitsuki , Noda Susumu , Takahashi Yasushi 
Published: January 2019

AbstractA feasible method for integrating several silicon (Si) photonic devices with operating wavelengths separated by several hundred nanometers on a single chip will greatly help increasing capacities of small optical communication modules. This work demonstrates the integration of two photonic crystal nanocavity devices that exhibit ultrahigh quality factors (Q) and operate at the 1.31‐ and 1.55‐µm bands. A dual thickness Si‐on‐insulator substrate forms the base of the device. The two nanocavity patterns are defined by electron beam lithography on the thick and thin substrate regions and are transferred to the top Si layer by performing plasma etching only once. All dimensions of the fabricated 1.31‐µm nanocavity are ≈15.5% smaller (1–1.31/1.55) than those of the 1.55‐µm nanocavity; that is, they can be treated with the same photonic band diagram. Both nanocavities exhibit an ultrahigh Q > 2.0 × 106 and enable fabrication of nanocavity‐based Raman lasers for the 1.31/1.55‐µm bands with sub‐microwatt threshold.
Reconfigurable Near‐field Enhancement with Hybrid Metal‐Dielectric Oligomers
Authors: Sun Yali , Sinev Ivan , Zalogina Anastasia , Ageev Eduard , Shamkhi Hadi , Komissarenko Filipp , Morozov Ivan , Lepeshov Sergey , Milichko Valentin , Makarov Sergey , Mukhin Ivan , Zuev Dmitry 
Published: January 2019

AbstractTailoring of the near‐field properties of the nanostructures is a significant task for the control of radiation of nanoscale light sources as well as for sensing applications. Generally, this task is solved in plasmonic oligomers on the fabrication step by the choice of geometry or by controlling the excitation light during the experiments. Here, the pronounced modification of the near‐field pattern in hybrid gold‐silicon oligomers by femtosecond laser reshaping by visualizing it with aperture‐type near‐field optical microscope is demonstrated. This effect correlates with a moderate red‐shift of the broadband magnetic dipole resonance of the structure that occurs upon reshaping the gold component of the oligomers. The proposed all‐optical near‐field reconfiguration approach makes hybrid oligomers a promising platform for on‐demand engineering of local field enhancement in metadevices for data recording and sensing.
Chain End‐Functionalized Polymer Brushes with Switchable Fluorescence Response
Authors: Tas Sinem , Kopec´ Maciej , van der Pol Rianne , Cirelli Marco , de Vries Ilse , Bölükbas Deniz A. , Tempelman Kristianne , Benes Nieck E. , Hempenius Mark A. , Vancso G. Julius , de Beer Sissi 
Published: January 2019

AbstractHerein is described the switchable fluorescence response of poly(methyl methacrylate) (PMMA) brushes. Chain end fluorescein labeled PMMA brushes are prepared by combining surface‐initiated atom transfer radical polymerization (SI‐ATRP) with a copper‐catalyzed alkyne‐azide cycloaddition (CuAAC) click reaction. Successful attachment of fluorescein is confirmed by measuring fluorescence of the as‐prepared films. Utilizing co‐solvency of PMMA in isopropanol‐water mixtures, responsive behavior of the end‐functionalized brushes is demonstrated by measuring the changes in fluorescence intensity between the swollen and collapsed states.
Design of an UWB antenna with two slits for 5G/WLAN‐notched bands
Authors: Bong Han‐Ul , Jeong Minjoo , Hussain Niamat , Rhee Seung‐Yeop , Gil Sang‐Keun , Kim Nam 
Published: January 2019

AbstractIn this article, we propose a dual notched‐band antenna with 2 slits for ultra‐wideband (UWB) applications. The antenna consists of a circular ground plane and a patch radiator with having 2 slits and a folding arm. The patch with folding arm is used to achieve UWB band while a V‐shaped and a split ring‐shaped slit are used to eliminate the interference from WLAN and 5G band, respectively. The width and length of the slits are optimized to obtain the necessary band notch characteristics. The prototype of the antenna having a total size of 75 × 10 mm2 is fabricated. Simulated and measured results show that the antenna covers the entire UWB frequency ranging from 2.754 to 14.656 GHz (127%) for VSWR < 2 except at notched bands. Moreover, the antenna successfully notched the WLAN band (5.15‐5.825 GHz) and 5G band (3.4‐3.7 GHz) besides of providing a stable gain and radiation patterns.
On the possibility of linear polarization in elliptical microstrip patch antenna
Authors: Mishra Suvendu Narayan , Konhar Diptimayee , Mishra Debasis , Mishra Rabindra Kishore 
Published: January 2019

AbstractThis article presents a linearly polarized, coaxial probe‐fed elliptical patch antenna, useful for C‐Band application areas. The suggested patch with an eccentricity of 0.866 is simulated. The prototype is fabricated and subsequent measurements are done. A simple theoretical method is developed to determine resonant frequency, which nearly matches with the simulation and experimental values, by incorporating and equivalently modifying the well‐known formulas of rectangular patch antenna. Some comparisons of experimental results of proposed patch with that of rectangular patch antenna suggest the potentiality of elliptical patch in terms of size, bandwidth, and realized gain at resonant frequency. It can also be suggested, here, that eccentricity and feed position determine the nature of polarization.
Bone retouchers from the Middle Palaeolithic site of El Salt, Stratigraphic Unit Xa (Alicante, Spain): First data and comparison with the Middle to Upper Pleistocene European record
Authors: Pérez Leopoldo , Hernández Cristo M. , Galván Bertila 
Published: January 2019

AbstractMiddle Palaeolithic sites frequently present bones with a double function, linked to subsistence and technology, which are generally referred to as “retouchers” or “bone retouchers.” These have been identified in several European sites from the Middle Pleistocene to Holocene, but different explanations of their origin and functionality have been cited. Although bone retouchers were made using various animal parts, they were usually produced from diaphyseal fragments of medium to large hoofed mammals. We present a small assemblage of six bone retouchers recovered from Stratigraphic Unit Xa (52.3 ± 4.6 ka), in the Middle Palaeolithic site of El Salt (Alicante, Spain), and compare our data with previous studies from several sites in south‐western France, northern Italy, and north‐eastern Spain. These tools were generated using diaphyseal fragments from red deer, horses, and other large mammals previously exploited by humans for meat and marrow. Our findings add to the existing knowledge on the behaviour and faunal resource management of the last Neanderthal groups on the western Iberian Peninsula before they disappeared from the region around 45–40 ka.
Association Between Cardiorespiratory Fitness and Risk of Type 2 Diabetes: A Meta‐Analysis
Authors: Qiu Shanhu , Cai Xue , Yang Bingquan , Du Ziwei , Cai Min , Sun Zilin , Zügel Martina , Michael Steinacker Jürgen , Schumann Uwe 
Published: January 2019

ObjectiveThis meta‐analysis aimed to (1) quantify the association of cardiorespiratory fitness (CRF) with type 2 diabetes risk in the general population and statin users and (2) investigate the joint effects of CRF and fatness with type 2 diabetes risk.MethodsDatabases were searched for cohort studies reporting the association between CRF and type 2 diabetes risk. Summary hazard ratios (HRs) were obtained using random‐effects models.ResultsFifteen studies were included. The HRs of type 2 diabetes for every 1–metabolic equivalent increase in CRF were 0.90 (95% CI: 0.86‐0.94) for the general population and 0.92 (95% CI: 0.87‐0.97) for statin users, and the HRs were linearly shaped (both Pnonlinearity > 0.40). Compared with the nonstatin cohort, there was an increased risk of type 2 diabetes in statin users with the lowest and moderate CRF categories, but this was not present in the highest CRF category. The HR of type 2 diabetes for overweight/obesity‐fit category versus normal weight–fit category was larger than that of the normal weight–unfit category versus the normal weight–fit category (Pinteraction = 0.004).ConclusionsThere was an inverse and dose‐dependent association between CRF and type 2 diabetes risk. High CRF may eliminate the diabetogenic effect from statins, yet decreased body weight index seems superior in preventing type 2 diabetes.
A mild and efficient procedure for alkenols oxyselenocyclization by using ionic liquids
Authors: Kostić Marina , Verdía Pedro , Fernández‐Stefanuto Verónica , Puchta Ralph , Tojo Emilia 
Published: January 2019

AbstractA mild and efficient procedure for the oxyselenocyclization of unsaturated alcohols by treatment with phenylselenyl chloride using ionic liquids as solvents/catalyzers has been developed. The reaction proceeds instantaneously under mild conditions with absolute regioselectivity, using primary, secondary, tertiary, and aromatic alcohols, as well as monosubstituted, disubstituted, and trisubstituted alkenols. This procedure provides a new method for the synthesis of substituted tetrahydrofurans and tetrahydropyrans ethers, the precursors of many biologically active metabolites, avoiding the use of toxic and corrosive catalysts. There are no previous reports of selenium‐mediated cyclofuncionalization reactions in ionic liquids. Taking into the account the good results obtained with [MMIM][MSO4], its ease preparation, low viscosity, low price, and its capacity to be recovered and reused, it was selected as the solvent/catalyzer. Quantum‐chemical calculations (MP2(fc)/6‐311 + G**//B3LYP/6‐311 + G**) has shown that the intramolecular cyclization is promoted by the hydrogen bond formed between the ionic liquid anion and the hydroxyl group of the alkenol.
Triarylpyridinium salts: Synthesis and electrochemical properties
Authors: Dolganov Alexandr V. , Tanaseichuk Boris S. , Pryanichnikova Margarita K. , Ivleva Alina Y. , Chernyaeva Oksana Y. , Grigoryan Karina A. , Chugunova Ekaterina A. , Yurova Veronika Y. 
Published: January 2019

AbstractThe electrochemical properties of the triarylpyridinium salts were studied. The effect of functional substituents on redox properties has been investigated in detail. Electrochemical reduction of salts to the anion in acetonitrile is the result of two one‐electron‐transfer steps through the stage of the radical formation and its subsequent reduction (EE electrochemical mechanism). A correlation between the reduction potentials and the structure of the salts was established.
Van der Waals effects on structure and optical properties in organic photovoltaics
Authors: Götz Andreas W. , Rodríguez Juan I. , Castillo‐Alvarado Fray L. , Trujillo‐González Daniel E. 
Published: January 2019

AbstractWe have recently reported that dispersion forces can have drastic effects on the structure and charge separation in organic photovoltaics (OPVs) (Martinez et al., J. Phys. Chem. C 121, 20 134 [2017]). Here we investigate dimer complexes formed by the polymer P3HT and the fullerene derivative PCBM. We show how van der Waals (vdW) interactions affect the geometrical structure, which has strong effects on the electronic structure and UV‐Vis absorption spectrum. Time‐dependent density functional theory calculations demonstrate that the experimentally observed blue‐shift of the absorption maximum of P3HT/PCBM OPV cells with respect to pure P3HT results mainly from distortions in P3HT due to vdW interactions between donor and acceptor fragments. Reduced absorption in the red region of the UV‐Vis spectrum results from distortions of P3HT and small charge transfer between P3HT and PCBM. These results are in qualitative agreement with experiments and recent theoretical results on the corresponding solid‐state films.
Laser ablation synthesis of carbon–phosphides from graphene/nanodiamond–phosphorus composite precursors: Laser desorption ionisation time‐of‐flight mass spectrometry
Authors: Mandal Govinda , Vaňhara Petr , Havel Josef 
Published: January 2019

RationaleCarbon–phosphides are new and promising strategic materials with applications e.g. in optoelectronics. However, their chemistry and methods of synthesis are not completely understood, and only a limited number of C–P clusters have been detected up to now. Laser ablation synthesis (LAS) or laser desorption ionisation (LDI) has great potential to generate CmPn clusters in the gas phase and to act as the basis for the development of new technology.MethodsThe LAS of carbon phosphides using mixtures of nano‐carbon sources (graphene, nanodiamonds) with phosphorus allotropes (red, black, and phosphorene) was examined. Since phosphorene is not commercially available, it was synthesised. A reflectron time‐of‐flight mass spectrometer was used to produce and identify the C–P clusters. A transmission electron microscope was used to characterise the prepared composites.ResultsLDI of various carbon–phosphorus composites generated a range of carbon–phosphides. From graphene–red phosphorus, CmP+ (m = 3–47), CmP2+ (m = 2–44), CmP3+ (m = 1–42), CmP4+ (m = 1–39), CmP5+ (m = 1–37), CmP6+ (m = 1–34), CmP7+ (m = 1–31), CmP8+ (m = 1–29), CmP9+ (m = 1–26), CmP10+ (m = 1–24), CmP11+ (m = 1–21), and CmP12+ (m = 1–19) clusters were detected, while nanodiamond composites with red/black phosphorus and with phosphorene yielded C24P5 + 2n+ (n = 0–28), C24P5 + 2n+ (n = 0–16), and C24P5 + 2n+ (n = 0–14) clusters, respectively. In total, over 300 new carbon–phosphide clusters were generated.ConclusionsThe novel series of carbon–phosphide clusters generated from graphene or nanodiamond composites with red/black phosphorus or with phosphorene demonstrated rich carbon–phosphide chemistry that might inspire the development of novel nano‐materials with specific properties.
Does women's political empowerment matter for improving the environment? A heterogeneous dynamic panel analysis
Authors: Lv Zhike , Deng Chao 
Published: January 2019

AbstractAccording to the UN Agenda 21 in 1992, women were regarded as a very important part in achieving sustainable development. In this agenda, participation, equality, and empowerment for females were emphasized as bases for sustainable development. In this paper, we make an attempt to explore the relationship between women's political empowerment (WPE) and CO2 emissions. To that end, we apply panel‐cointegration techniques to investigate both long‐term and short‐term effects of WPE on the environment in 72 countries during 1971–2012. The results from the pooled mean group (PMG) estimator indicate that, in the long run, CO2 emissions decrease by about 11.51 percent points in response to a one‐unit increase in the index of WPE after controlling for a variety of other factors. However, the short‐term estimated coefficient of WPE is statistically insignificant. Moreover, further study shows that women's civil society participation has the largest effect, followed by political participation. Another noteworthy result is the effect of energy intensity. We find that both the long‐term and short‐term estimated coefficient of energy intensity are positive and highly statistically significant, but the magnitude of the short‐term estimated coefficient is lower than the long‐term one. This comparison suggests that the influence of energy intensity on CO2 emissions would usually take some time to materialize fully. From a policy perspective, our estimation results suggest that improving the status of women worldwide, especially in the developing countries, can reduce CO2 emissions.
Organoacid‐Decorated NiFe2O4 Nanoparticles: An Efficient Catalyst for Green Synthesis of 2H‐Indazolo[2, 1‐b]phthalazine‐Triones and Pyrimido[1,2‐a]benzimidazoles
Authors: Hamidinasab Mahdia , Mobinikhaledi Akbar 
Published: January 2019

AbstractOrgano‐Sulfonic acid tags anchored on magnetic titana coated NiFe2O4 nanoparticles (nano‐NiFe2O4@TiO2‐SiO2‐Pr‐DEA‐OSO3H) was prepared and characterized by various analysis methods including Fourier transform infrared (FT‐IR) spectroscopy, field emission scanning electron microscopy (FE‐SEM), energy dispersive X‐ray spectroscopy (EDS), vibrating sample magnetometer (VSM), X‐ray diffraction (XRD) and thermo gravimetric analysis (TGA). These modified nanoparticles were used as efficient and recoverable hybrid nanocatalyst in multicomponent synthesis of some phthalazine‐trione and benzo[4,5]imidazo[1,2‐a]pyrimidine derivatives under green conditions. High yields within shorter reaction times, simple purification, and environmentally mild reaction conditions are some advantages of this protocol.
Fluorescent Gadolinium(III)‐Oligopeptide Complexes and Carbon Nanotube Composite as Dual Modality Anticancer Agents
Authors: Sheikh Aasif Hassan , Khalid Anam , Khan Farah , Begum Ameerunisha 
Published: January 2019

AbstractIn search of non‐platinum based anticancer drugs, we have synthesized and characterized a new class of three gadolinium(III)‐oligopeptides [Gd(L1)2(NO3)2][NO3] (1, L1=l‐aspartyl(OMe)‐N‐boc‐l‐aspartyl‐l‐aspartyl (OMe)), [Gd(L2)2(NO3)2][NO3] (2, L2=N‐fmoc‐l‐arginyl‐(Pbf)‐glycyl‐l‐aspartyl(OMe)), [Gd(L3)(NO3)3] (3, L3=N‐fmoc‐l‐arginyl‐(Pbf)‐l‐arginyl(OMe) and a carbon nanotube composite, 1@CNT 4. The three oligopeptides, L1 – L3 were prepared in a novel synthetic route using tetramethyl benzotriazolyl uronium hexaflurophosphate (HBTU) as a peptide coupling reagent. Confocal microscopic analysis of the gadolinium(III)‐oligopeptides, 1, 2 and CNT composite, 1@CNT 4 indicate that they display white and green light emissions upon excitations at λ, 405 and 488 nm with characteristic patterns. The oligopeptides, L1 & L3 display in vitro anticancer activity on HeLa cells with IC50 values in one mM concentration whereas the IC50 of RGD‐based oligopeptide was found to be 1 μM. The IC50 of gadolinium(III)‐oligopeptide, 1 and the CNT composite, 4 were found to be 1 μM and 10 nM. The transmission electron microscopic investigation of the HeLa cells treated with the composite 4 confirm the cellular uptake and indicate the presence of CNTs in the cytoplasm and that CNTs appear like bullets carrying the gadolinium(III)‐triaspartate, 1.
Syntheses, X‐Ray Crystal Structures, Emission Properties and DFT Calculations of Monoprotonated Polypyridines
Authors: Yoshikawa Naokazu , Yamazaki Shoko , Kato Natsumi , Kubota Akari , Sawai Mika , Noda Kaoru , Kanehisa Nobuko , Inoue Tsuyoshi , Nakata Eiji , Takashima Hiroshi 
Published: January 2019

AbstractMonoprotonated compounds [(L)HPF6] were prepared by the reaction of (L=bpy, phen, dpphen, bqn and ppy) with concentrated HCl in water. Monoprotonated pyridine rings are hydrogen bonded intramolecularly to the adjacent pyridine ring and intermolecularly to the adjacent PF6− in compounds. These hydrogen bonds restrain the nonradiative decay to produce intense emission. Density functional theory was applied to interpret the planarity in compounds. The attachment of one proton to the nitrogen in [(dpphen)HPF6] and [(bqn)HPF6] leads to the strong emission in acetonitrile (Φ = 0.046 and 0.097, respectively). In particular, the attachment of one proton to the ppy nitrogen results in exhibiting a strong emission with a large quantum yield (Φ = 0.264).