bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphology‐Tuned Activity of Ru/Nb2O5 Catalysts for Ketone Reductive Amination
Authors: Guo Wanjun , Tong Tao , Liu Xiaohui , Guo Yong , Wang Yanqin 
Published: April 2019

AbstractAmines are important compounds in natural products and medicines. Specifically, cyclopentylamine is one of the value‐added chemicals widely used in the production of pesticides, cosmetics and medicines. In this work, three Ru/Nb2O5 catalysts with different Nb2O5 morphologies were used in the reductive amination of cyclopentanone under mild reaction conditions (90 °C, 2 MPa H2), among which 1 %Ru/Nb2O5−L catalyst exhibits best performance with the yield of cyclopentylamine reaching 84 %. This catalytic system is stable and has not significant deactivation even after 5 runs in the durability test. In addition, this catalyst can be extended to a series of aldehydes/ketones. Further comprehensive characterizations (XPS analysis and CO‐adsorption DRIFT) reveal that the electronic effect of Ru species can be ruled out; instead, the activity of the catalyst is strongly influenced by the geometric effect. Layered Nb2O5 material possesses the highest surface area, resulting in the highest Ru dispersion, and therefore shows the highest catalytic activity. The in‐situ DRIFT‐MS technique was also used to reveal and understand the reaction mechanism. It is found that Ru species play a key role in activating carbonyl groups. This study illustrates a promising application of Ru/Nb2O5‐Layer catalyst in the synthesis of amine and provides an understanding to the reaction mechanism.
Simulative Approach for Linking Electrode and Electrolyte Properties to Supercapacitor Performance
Authors: Krois Konrad , Hüfner Lucas , Gläsel Jan , Etzold Bastian J. M. 
Published: April 2019

AbstractSupercapacitors as energy storage devices show distinct advantages like high power density and high cycle stability. While in current applications, mainly the high power density is leveraged, future non‐mobile storage devices could also benefit from the robustness and materials employed, while lower charging/discharging time constants are acceptable. In this study, a simulative approach is employed to investigate the complex interplay of mass transfer, electric losses, double layer capacitance for different electrode thicknesses, electrode and electrolyte conductivities as well as charging/discharging time constants. Within the simulation cyclic voltammetry, galvanostatic cycling as also electrochemical impedance spectroscopy experiment could be realized, showing the dependency of achievable maximum capacitance and voltage efficiency on various properties.
Research on Alzheimer's Disease – an interdisciplinary learning concept
Authors: Rößler Tina , Alia‐Matysik Alia , Heimann Rebekka 
Published: April 2019

AbstractIm Rahmen dieses Beitrags wird eine Unterrichtseinheit zum Thema Alzheimerkrankheit (AD) vorgestellt, die in der Stufe 10 des Gymnasiums erprobt wurde. Außer der Vernetzung von biologischen und chemischen Inhalten soll ein Einblick in aktuelle Forschung ermöglicht werden. In vielen Phasen sind die Schülerinnen und Schüler selbstständig tätig.
CaCoxZr1−xO3−δ Perovskites as Oxygen‐Selective Sorbents for Air Separation
Authors: Zheng Qinghe , Lail Marty , Zhou Shaojun , Chung Ching‐Chang 
Published: April 2019

AbstractABO3−δ perovskites are ideal for high‐temperature thermochemical air separation for oxygen production because their oxygen nonstoichiometry δ can be varied in response to changes in temperature and oxygen partial pressure [
]. Herein, the outstanding oxygen‐sorption performance of CaCoxZr1−xO3−δ perovskites and their potential application as oxygen‐selective sorbents for air separation is reported. In situ thermal X‐ray diffraction was used to study the materials’ structural changes in response to temperature variations in air and inert atmosphere. Temperature‐programmed reduction was employed to elucidate the relationship between perovskite composition and redox property. O2 sorption performance was evaluated by isothermal analyses at various temperature and
along with long‐term absorption–desorption cycle tests. The high oxygen‐sorption capacity was mainly attributed to Co at B‐site, whereas partial substitution of Co by Zr enhanced the structural crystallinity and thermal stability of the perovskite. A stable oxygen production of 2.87 wt % was observed at 900 °C during 5 min‐sorption cycles for 100 cycles.
Uncovering mechanisms of bird seed dispersal in semiarid environments to help to restore them
Authors: Martínez‐López V. , Zapata V. , De la Rúa P. , Robledano F. 
Published: April 2019

AbstractMediterranean semiarid areas are suffering a growing process of agricultural abandonment that represents a challenge for restoration. Limited seed arrival, drought, and scarce suitable microhabitats in oldfields make plant colonization difficult. Restoration through ecological succession can take advantage of increased seed dispersal through animal vectors, but precise knowledge of the factors involved (e.g., seed disperser behavior, rate of effective recruitment of dispersed seeds, and effectiveness of the applied restoration structures) is critical. Otherwise, efforts to foster the processes of interest may be misdirected. We propose and test a methodological approach based on the combination of ecological (bird censuses and camera trapping) and genetic tools (DNA barcoding), to assess seed dispersal of fleshy‐fruited shrub species by birds toward oldfields in one of the driest areas of southeastern Spain. We assisted natural restoration with artificial bird attractors (perches and water troughs) in two abandoned areas with different ages. Furthermore, we provided microenvironments (rocks) and prevented herbivory (by fencing) to enhance plant recruitment. Results revealed strong differences among assessment techniques in the characterization of dispersal interactions. While bird censuses only informed about frugivores occurrence, camera trapping and barcoding enabled the quantification of species responses. Attractors proved to be effective in triggering a quantifiable seed arrival, but no subsequent plant establishment occurred. We highlight the importance of implementing different techniques to characterize and assess avian seed disperser performance. Water provision increased seed arrival, but our design failed to enhance plant recruitment. The next logical step in the restoration of Mediterranean oldfields is the optimization of conditions for seed germination and successful plant establishment.
Energy capacity and seismic performance of RC waffle‐flat plate structures under two components of far‐field ground motions: Shake table tests
Authors: Benavent‐Climent Amadeo , Galé‐Lamuela David , Donaire‐Avila Jesús 
Published: April 2019

SummaryThe bidirectional response of a portion of a reinforced concrete (RC) waffle‐flat plate (WFP) structure subjected to far‐field ground motions is studied through shake table tests. The test specimen is a scaled portion of a prototype structure designed under current building codes and located in a region of moderate seismicity of the Mediterranean area. The specimen was subjected to a sequence of tests of increasing acceleration amplitude that respectively represented very frequent, frequent, design, and very rare earthquakes at the site. The test structure performed well (basically in the elastic domain) under very frequent and frequent earthquakes, approached the boundary between the performance levels of life safety and near collapse under the design earthquake, and collapsed under the very rare earthquake. Damage concentrated at column bases and at the transverse beams of the exterior plate‐to‐column connection. Columns dissipated about 10% of the total energy that contributes to damage, and the rest was dissipated by the exterior plate‐column connection. The total energy input on the structure until collapse under the bidirectional seismic action was very close to the value obtained in previous studies on a similar specimen tested under unidirectional ground motions. The capacity curve estimated from the experimental base shear vs top displacement relationship suggests it is best to use a behavior factor of at most q = 2 when designing WFP structures with the reduced‐spectrum force‐based approach.
Microplastic–Contaminant Interactions: Influence of Nonlinearity and Coupled Mass Transfer
Authors: Seidensticker Sven , Zarfl Christiane , Cirpka Olaf Arie , Grathwohl Peter 
Published: April 2019

Abstract
Microplastic particles are ubiquitously detected in the environment. Despite intensive public and scientific discussions, their potential to transport contaminants in rivers and oceans under environmental conditions is still under assessment. In the present study we measured sorption isotherms and kinetics in batch experiments using phenanthrene (as a typical hydrophobic wastewater contaminant) and microplastic particles of different sizes and materials. We observed a linear sorption isotherm for polyethylene, in contrast to nonlinear sorption of polyamide and polystyrene, which could be best described by the Freundlich and the Polanyi–Dubinin–Manes isotherms, respectively. We modeled sorption kinetics as a combination of external mass transfer governed by diffusion through an aqueous boundary layer and intraparticle diffusion within the plastic. Which of these processes controls the kinetics depends on the sorption strength, particle size, diffusion coefficients, and time. We used semi-analytical and numerical methods to simulate the coupled mass transfer for both linear and nonlinear sorption. We successfully applied the semi-analytical model to polyethylene and the numerical code to polyamide and polystyrene, reproducing the measured kinetics and obtaining reasonable values for mass transfer and intraparticle diffusion coefficients. Subsequently, we used these coefficients to estimate the transport potential and relevant time scales for microplastic-bound contaminants under environmental conditions. Environ Toxicol Chem 2019;38:1635–1644. © 2019 SETAC
Abstract
Time scales for 50% desorption under different conditions.
Research Impact on Emerging Quantum Materials for Electrochromic Applications
Authors: Koo Bon‐Ryul , Ahn Hyo‐Jin 
Published: April 2019

AbstractElectrochromic devices (ECDs), which can dynamically vary optical properties under applied specific voltage, have been actively studied for use in applications requiring human comfort and energy efficiency (i. e. smart windows and electronic displays). In order to improve the electrochromic (EC) performances, many researchers have been using nanomaterials. In this respect, in the present study, we highlight some of valuable examples using WO3 from unique nanostructures to quantum dots (QDs) and discuss the core relationship between nanostructuring and EC performances. In particular, the present study proposes major impact on the novel approach using QDs to upgrade technical value and application of ECDs.
Annexin A3 depletion overcomes resistance to oxaliplatin in colorectal cancer via the MAPK signaling pathway
Authors: Xu Ruisi , Yin Jian , Zhang Ying , Zhang Siqi 
Published: April 2019

AbstractColorectal cancer (CRC) is a common disease with high mortality and morbidity. Annexin A3 (ANXA3) belongs to the structurally homologous family of Ca2+ and phospholipid‐binding proteins. This study aimed to investigate the effects and potential mechanisms of ANXA3 on oxaliplatin (Ox) resistance in CRC. We generated two human CRC cell lines (HCT116/Ox and SW480/Ox) with acquired Ox resistance and determined their resistance properties. ANXA3 expression and cell apoptosis, migration and invasion also were evaluated. We found that cell viability of HCT116/Ox and SW480/Ox was higher than that in parental cells in the presence of Ox. ANXA3 was highly expressed in HCT116/Ox and SW480/Ox cells. ANXA3 downregulation diminished cell survival, migration and invasion, while increased the apoptosis of HCT116 and SW480 with or without Ox. Moreover, depletion of ANXA3 reduced cell viability and BrdU incorporation, increased cell apoptosis and c‐caspase 3 expression in HCT116/Ox with or without Ox. A transwell assay determined that knockdown of ANXA3 impeded the migration and invasion of HCT116/Ox and SW480/Ox cells. Additionally, phosphorylation of extracellular signal–regulated kinase (ERK) and c‐Jun N‐terminal kinase (JNK) decreased upon ANXA3 depletion in HCT116/Ox cells, and ANXA3 silencing suppressed Ox‐induced activation of ERK and JNK signaling pathway. ANXA3 downregulation reduced Ox resistance in CRC, and treatment with the ERK inhibitor PD098059 or JNK inhibitor SP600125 contributed to this process. These results indicate that silencing ANXA3 could overcome Ox resistance in CRC via the mitogen‐activated protein kinase signaling pathway.
Potential of stem cell‐derived exosomes to regenerate β islets through Pdx‐1 dependent mechanism in a rat model of type 1 diabetes
Authors: Mahdipour Elahe , Salmasi Zahra , Sabeti Nona 
Published: April 2019

AbstractType 1 diabetes, has been recognized as an autoimmune disease. Like other immunological conditions, regulation of immune response is a key strategy to control the autoimmunity in diabetic patients. Mesenchymal stem cells have been shown to have a distinct potential in modulating the immune reactions. However, treatment with stem cells is combined with concerns about safety issues. To overcome these concerns, in this study, we have utilized the regenerative potential of exosomes isolated from menstrual blood‐derived mesenchymal stem cells to restore the β‐cell mass and insulin production in type 1 diabetes. Exosomes are nanovesicles containing various cargos involved in cellular communications. Streptozotocin was used to induce islet destruction and diabetes in male Wistar rats. Then, exosomes were intravenously injected into animals at different time points and in a single or repeated therapeutic doses. After about 6 weeks, animals were euthanized and the pancreas was analyzed for the presence of the regenerated β islets as well as the insulin secretion. The non‐fasting blood glucose and the serum insulin level were also monitored during the study. Our results represented that menstrual blood‐derived mesenchymal stem cell‐derived exosomes enhance the β‐cell mass and insulin production in the pancreas of diabetic animals that received repeated doses of exosomes. Immunohistochemistry analysis also confirmed the presence of insulin in the islets of treated animals. Further investigations proposed that exosomes induce the islet regeneration through pancreatic and duodenal homeobox 1 pathway. The exosome tracking also revealed the homing of injected exosomes to the pancreas.
The impairment in the NLRP3-induced NO secretion renders astrocytes highly permissive to T. cruzi replication
Authors: Pacheco Aline L , Vicentini Gabriella , Matteucci Kely C , Ribeiro Rafaela Rosa , Weinlich Ricardo , Bortoluci Karina R 
Published: April 2019

Abstract
Trypanossoma cruzi (T. cruzi), the causative protozoan of Chagas disease (CD) invades many cell types, including central nervous system (CNS) cells triggering local lesions and neurological impact. Previous work from our group described NLRP3 inflammasomes as central effectors for the parasite control by macrophages. Recent evidences demonstrate that NLRP3 can be activated in CNS cells with controversial consequences to the control of infections and inflammatory pathologies. However, the relative contribution of NLRP3 in different cell types remains to be elucidated. In this article, we described an effector response mediated by NLRP3 that works on microglia but not on astrocytes to control T. cruzi infection. Despite T. cruzi ability to invade astrocytes and microglia, astrocytes were clearly more permissive to parasite replication. Moreover, the absence of NLRP3 renders microglia but not astrocytes more permissive to T. cruzi replication. In fact, microglia but not astrocytes were able to secrete NLRP3-dependent IL-1β and NO in response to T. cruzi. Importantly, the pharmacological inhibition of iNOS with aminoguanidine resulted in a significant increase in the numbers of amastigotes found in microglia from wild-type but not from NLRP3−/− mice, indicating the importance of NLRP3-mediated NO secretion to the infection control by these cells. Taken together, our findings revealed that T. cruzi differentially activates NLRP3 inflammasomes in astrocytes and microglia and established a role for these platforms in the control of a protozoan infection by glial cells from CNS.
Structural stabilization of soil backfill with quicklime
Authors: Zimmermann Iris , Filser Stefan , Mordhorst Anneka , Fleige Heiner , Horn Rainer 
Published: April 2019

AbstractThe application of quicklime (CaO) to soil backfill for the amelioration of poorly aerated grave soils (sandy loam) was tested in a cemetery in Germany. Two grave simulations (soil pits 9 m × 2 m × 1.6 m, l × w × d) were set up. Variation sans was only excavated and refilled, while in variation qlm, 20 kg quicklime per m3 soil were added to the backfill. Soil matric potential and gas composition were recorded over a period of 24 months in the two refilled pits and in the surrounding undisturbed soil (ref) at the 50 cm and 135 cm depths, respectively. Soil samples were taken in the beginning from ref and in three‐month intervals from the treatments sans and qlm. Soil pH and CaCO3 content, as well as bulk density (ρB), air capacity (AC), air conductivity (kl), and saturated hydraulic conductivity (ks) were measured. Excavation and backfill of the untreated soil (sans) led to an increase in ρB at the 50 and 90 cm depths and decreases in AC, kl, and ks when compared to ref. Quicklime application led to an increase in pH, the formation of CaCO3 in the formerly carbonate‐free soil, consistently reduced ρB, and increased AC, kl and ks. Although the quicklime application did not lead to notably more negative matric potentials, it increased the O2 concentration in the soil air and reduced the CO2 concentration to zero. The results show that the application of quicklime helps the structural amelioration of cemetery soils even at relatively low clay contents.
Seasonal and diel variation in greenhouse gas emissions from an urban pond and its major drivers
Authors: van Bergen Tamara J. H. M. , Barros Nathan , Mendonça Raquel , Aben Ralf C. H. , Althuizen Inge H. J. , Huszar Vera , Lamers Leon P. M. , Lürling Miquel , Roland Fábio , Kosten Sarian 
Published: April 2019

AbstractSmall water systems are important hotspots of greenhouse gas (GHG) emission, but estimates are poorly constrained as data are scarce. Small ponds are often constructed in urban areas, where they receive large amounts of nutrients and therefore tend to be highly productive. Here, we investigated GHG emissions, seasonal and diel variation, and net ecosystem production (NEP) from an urban pond. In monthly 24‐h field campaigns during 11 months, diffusive water–atmosphere methane (CH4) and carbon dioxide (CO2) fluxes and CH4 ebullition and oxidation were quantified. With oxygen (O2) measurements, NEP was assessed. The pond was a net GHG source the entire year, with an emission of 3.4 kg CO2 eq m−2 yr−1. The dominant GHG emission pathway was CH4 ebullition (bubble flux, 50%), followed by diffusive emissions of CO2 (38%) and CH4 (12%). Sediment CH4 release was primarily driven by temperature and especially ebullition increased exponentially above a temperature threshold of 15°C. The pond's atmospheric CO2 exchange was not related to NEP or temperature but likely to a high allochthonous carbon (C) input via runoff and anaerobic mineralization of C. We expect urban ponds to show a large increase in GHG emission with increasing temperature, which should be considered carefully when constructing ponds in urban areas. Emissions may partly be counteracted by pond management focusing on a reduction of nutrient and organic matter input.
Surface‐Independent and Oriented Immobilization of Antibody via One‐Step Polydopamine/Protein G Coating: Application to Influenza Virus Immunoassay
Authors: Moon Jeong , Byun Jihyun , Kim Hongki , Jeong Jinyoung , Lim Eun‐Kyung , Jung Juyeon , Cho Soojeong , Cho Woo Kyung , Kang Taejoon 
Published: April 2019

AbstractFor the construction of high‐performance biosensor, it is important to interface bioreceptors with the sensor surface densely and in the optimal orientation. Herein, a simple surface modification method that can optimally immobilize antibodies onto various kinds of surfaces is reported. For the surface modification, a mixture of polydopamine (PDA) and protein G was employed. PDA is a representative mussel‐inspired polymer, and protein G is an immunoglobulin‐binding protein that enables an antibody to have an optimal orientation. The surface characteristics of PDA/Protein G mixture‐coated substrates are analyzed and the PDA/protein G ratio is optimized to maximize the antibody binding efficiency. Moreover, the antibody‐immobilized substrates are applied to the detection of influenza viruses with the naked eye, providing a detection limit of 2.9 × 103pfu mL‐1. Importantly, the several substrates (glass, SiO2, Si, Al2O3, polyethylene terephthalate, polyethylene, polypropylene, and paper) can be modified by simple incubation with the mixture of PDA/protein G, and then the anti‐influenza A H1N1 antibodies can be immobilized on the substrates successfully. Regardless of the substrate, the influenza viruses are detectable after the sandwich immunoreaction and silver enhancement procedure. It is anticipated that the developed PDA/protein G coating method will extend the range of applicable materials for biosensing.
EPR spectroscopy of multicomponent, multispin molecular system obtained by the photolysis of 2,4,6‐triazido‐3‐cyano‐5‐fluoropyridine in solid argon
Authors: Chapyshev Sergei V. , Korchagin Denis V. , Grote Dirk , Sander Wolfram 
Published: April 2019

AbstractComplex multicomponent, multispin molecular system, consisting of a septet trinitrene, two quintet dinitrenes, and three triplet mononitrenes, was obtained by the photolysis of 2,4,6‐triazido‐3‐cyano‐5‐fluoropyridine in solid argon. To identify these paramagnetic products, electron paramagnetic resonance spectroscopy in combination with line‐shape spectral simulations and density functional theory calculations was used. The products of the photolysis was found to be triplet 2,4‐diazido‐3‐cyano‐5‐fluoropyridyl‐6‐nitrene (DT = 1.000 cm−1, ET = 0), triplet 2,4‐diazido‐3‐cyano‐5‐fluoropyridyl‐2‐nitrene (DT = 1.043 cm−1, ET = 0), triplet 2,6‐diazido‐3‐cyano‐5‐fluoropyridyl‐4‐nitrene (DT = 1.128 cm−1, ET = 0 cm−1), quintet 4‐azido‐3‐cyano‐5‐fluoropyridyl‐2,6‐dinitrene (DQ = 0.211 cm−1, EQ = 0.0532 cm−1), quintet 2‐azido‐3‐cyano‐5‐fluoropyridyl‐4,6‐dinitrene (DQ = 0.208 cm−1, EQ = 0.0386 cm−1), and septet 3‐cyano‐5‐fluoropyridyl‐2,4,6‐trinitrene (DS = −0.1017 cm−1, ES = −0.0042 cm−1) in a 38:4:7:22:14:4 ratio, respectively.