bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics of hydroformylation of 1‐decene using carbon‐supported ossified HRh(CO)(TPPTS)3 catalyst
Authors: Pagar Nitin S. , Deshpande Raj M. 
Published: December 2018

AbstractThe kinetics of hydroformylation of 1‐decene has been investigated using a carbon‐supported ossified HRh(CO)(TPPTS)3/Ba catalyst in a temperature range of 343–363 K. The effect of concentration of 1‐decene, catalyst loading, partial pressure of H2 and CO, and stirring speed on the reaction rate has been investigated. A first‐order dependence was observed for catalyst concentration and hydrogen partial pressure. The rate showed a typical case of substrate inhibition for high 1‐decene concentration. The rate varied with a linear dependence on PCO up to a CO partial pressure of 5–6 MPa in contrast to the general trends; for most of the rhodium‐phosphine catalyzed hydroformylation reactions, severe inhibition of rate is observed with an increase in CO pressure. A rate equation has been proposed, which was found to be in good agreement with the observed rate data within the limit of experimental errors. The kinetic parameters and activation energy values have been reported.
Biological transformation of Arctic dissolved organic matter in a NE Greenland fjord
Authors: Lund Paulsen Maria , Müller Oliver , Larsen Aud , Møller Eva Friis , Middelboe Mathias , Sejr Mikael K. , Stedmon Colin 
Published: December 2018

AbstractArctic waters are often enriched with terrestrial dissolved organic matter (DOM) characterized by having elevated visible wavelength fluorescence (commonly termed humic‐like). Here, we have identified the sources of fluorescent DOM (FDOM) in a high Arctic fjord (Young Sound, NE Greenland) influenced by glacial meltwater. The biological transformation of FDOM was further investigated using plankton community size‐fractionation experiments. The intensity of ultraviolet fluorescence (commonly termed amino acid‐like) was highly variable and positively correlated to bacterial production and mesozooplankton grazing. The overall distribution of visible FDOM in the fjord was hydrographically driven by the high‐signal intrusion of Arctic terrestrial DOM from shelf waters and dilution with glacial runoff in the surface waters. However, the high‐intensity visible FDOM that accumulated in subsurface waters in summer was not solely linked to allochthonous sources. Our data indicate that microbial activity, in particular, protist bacterivory, to be a source. A decrease in visible FDOM in subsurface waters was concurrent with an increase in bacterial abundance, indicating an active bacterial uptake or modification of this DOM fraction. This was confirmed by net‐loss of visible FDOM in experiments during summer when bacterial activity was high. The degradation of visible FDOM appeared to be associated with bacteria belonging to the order Alteromonadales mainly the genus Glaciecola and the SAR92 clade. The findings provide new insight into the character of Arctic terrestrial DOM and the biological production and degradation of both visible and UV wavelength organic matter in the coastal Arctic.
Differential stimulation and suppression of phytoplankton growth by ammonium enrichment in eutrophic hardwater lakes over 16 years
Authors: Swarbrick Vanessa J. , Simpson Gavin L. , Glibert Patricia M. , Leavitt Peter R. 
Published: December 2018

AbstractPrevious research suggests that fertilization of surface waters with chemically reduced nitrogen (N), including ammonium (NH4+), may either enhance or suppress phytoplankton growth. To identify the factors influencing the net effect of NH4+, we fertilized natural phytoplankton assemblages from two eutrophic hardwater lakes with growth‐saturating concentrations of NH4Cl in 241 incubation experiments conducted biweekly May–August during 1996–2011. Phytoplankton biomass (as chlorophyll a) was significantly (p < 0.05) altered in fertilized trials relative to controls after 72 h in 44.8% of experiments, with a marked rise in both spring suppression and summer stimulation of assemblages over 16 yr, as revealed by generalized additive models (GAMs). Binomial GAMs were used to compare contemporaneous changes in physico‐chemical (temperature, Secchi depth, pH, nutrients; 19.5% deviance explained) and biological parameters (phytoplankton community composition; 40.0% deviance explained) to results from fertilization experiments. Models revealed that that the likelihood of growth suppression by NH4+ increased with abundance of diatoms, cryptophytes, and unicellular cyanobacteria, particularly when water temperatures and soluble reactive phosphorus (SRP) concentrations were low. In contrast, phytoplankton was often stimulated by NH4+ when chlorophytes and non‐N2‐fixing cyanobacteria were abundant, and temperatures and SRP concentrations were high. Progressive intensification of NH4+ effects over 16 yr reflects changes in both spring (cooler water, increased diatoms and cryptophytes) and summer lake conditions (more chlorophytes, earlier cyanobacteria blooms), suggesting that the seasonal effects of NH4+ will vary with future climate change and modes of N enrichment.
SIRT3 Deficiency Promotes High‐Fat Diet‐Induced Nonalcoholic Fatty Liver Disease in Correlation with Impaired Intestinal Permeability through Gut Microbial Dysbiosis
Authors: Chen Mengting , Hui Suocheng , Lang Hedong , Zhou Min , Zhang Yong , Kang Chao , Zeng Xianglong , Zhang Qianyong , Yi Long , Mi Mantian 
Published: December 2018

ScopeSirtuin 3 (SIRT3) plays a protective role against nonalcoholic fatty liver disease (NAFLD) by improving hepatic mitochondrial dysfunction. Gut microbiota imbalance contributes to the pathogenesis of NAFLD, yet the underlying mechanism linking SIRT3 with gut microbiota in NAFLD progression remains obscure.Methods and resultsWild‐type 129 mice and SIRT3 knockout (SIRT3KO) mice are placed under a chow diet or high‐fat diet (HFD) treatment for 18 weeks. HFD resulted in a significantly increased hepatic steatosis and inflammation, which are exacerbated in SIRT3KO mice. The gut microbiota by 16s rRNA gene sequencing and phylogenetic reconstruction of unobserved states analysis are characterized. Lack of SIRT3 facilitates gut microbial dysbiosis in mice following HFD, with increased Desulfovibrio, Oscillibacter, and decreased Alloprevotella. SIRT3 deficiency resulted in an impaired intestinal permeability and inflammation in HFD‐fed mice, which can be attenuated by sodium butyrate (NaB). SIRT3KO HFD‐fed mice is followed by an increased lipopolysaccharide into the circulation and dysregulated expressions of cannabinoid receptor 1 and 2 in colon and liver, which are significantly associated with the alterations of intestinal microbiota.ConclusionsSIRT3 deficiency promotes NAFLD progression in correlation with impaired intestinal permeability through gut microbiota dysbiosis.
The design of optically controlled phase shifter based on silicon photosensitivity
Authors: Meng Ru , Xia Yulong , Li Yongguang , Zhu Qi 
Published: December 2018

AbstractBased on the photosensitivity of silicon, a novel optically controlled microwave phase shifter is proposed, which consists of a Xenon lamp and a rectangular waveguide inserted with a silicon slice. By altering the intensity of illumination, the presented structure can change the phase of transmission coefficient efficiently. The performance of the phase shifter is theoretically analyzed and simulated. Experiments are conducted at X band, and the results show that a phase shift of 44° can be obtained, and the insertion loss is 5.8 dB. Especially, the power capacity of the presented structure reaches to 460 MW under vacuum state according to the simulation, which is far greater than traditional microwave phase shifters. This novel structure is attractive for high power microwave (HPM) applications.
Energy yield of all thin‐film perovskite/CIGS tandem solar modules
Authors: Langenhorst Malte , Sautter Benjamin , Schmager Raphael , Lehr Jonathan , Ahlswede Erik , Powalla Michael , Lemmer Uli , Richards Bryce S. , Paetzold Ulrich W. 
Published: December 2018

AbstractPerovskite/CuIn1 − xGaxSe2 (CIGS) tandem photovoltaics (PV) promises high power conversion efficiencies in combination with the advantages of a light weight and an all thin‐film PV technology. However, the complexity of perovskite/CIGS tandem solar module architectures requires careful optimization of the layer stack under realistic solar irradiation conditions. Here, we provide a systematic numerical study on the energy yield (EY) of perovskite/CIGS tandem solar modules, optimizing the device architecture with regard to irradiance in various climate zones. In particular, variations of the spectral irradiation and the average photon energy are of decisive importance for the location‐specific optimization of the device architecture. Compared with the reference single‐junction CIGS thin‐film PV technology, we demonstrate a strong improvement in EY (>30%) in perovskite/CIGS thin‐film PV for perovskites of a wide range of bandgaps (1.55 ‐ 2.0 eV), reaching up to 52% improvement in EY for the optimal bandgap (around 1.8 eV). Of the two most favored architectures, the two‐terminal and four‐terminal devices, perovskite/CIGS tandem solar modules with low bandgap (∼1.55 eV) perovskite absorbers in the four‐terminal architecture outperform those in the two‐terminal architecture in average by 3.5% relative. However, for wide perovskite bandgaps ranging from 1.75 eV to 1.85 eV, both architectures perform comparably. The improvements in EY for perovskite/CIGS tandem solar modules highlight the potential of this technology but also the vital need for light management in tandem photovoltaics.
A nationwide survey on tracheostomy for very‐low‐birth‐weight infants in Japan
Authors: Kurata Hiroaki , Ochiai Masayuki , Inoue Hirosuke , Ichiyama Masako , Yasuoka Kazuaki , Fujiyoshi Junko , Matsushita Yuki , Honjo Satoshi , Sakai Yasunari , Ohga Shouichi ,   on behalf of the Neonatal Research Network of Japan
Published: December 2018

ObjectivesTracheostomy is indicated for very‐low‐birth‐weight infants (VLBWIs) with prolonged respiratory problems during the perinatal period. The objective of this study is to clarify the epidemiology and risk factors in VLBWIs with tracheostomy after birth in Japan.MethodsA total of 40 806 VLBWIs were registered in the Neonatal Research Network of Japan database from 2003 to 2012. Among them, 34 674 infants (85%) survived over 28 days after birth and were subjected to this study. The clinical variables at birth, outcomes at hospital discharge and associated factors for tracheostomy were examined.ResultsThe proportion of VLBWIs with tracheostomy did not increase during the study period (mean 36 cases per year, 0.93%). The rate of in‐hospital death over 28 days after birth did not differ between tracheostomized and non‐tracheostomized infants (2/324, 0.6% vs 314/34 350, 0.9%). Tracheostomized infants more frequently had severe or moderate bronchopulmonary dysplasia (BPD) (75.5% vs 26.0%, P < 0.01) and longer hospitalization (229 days vs 83 days, P < 0.01) than non‐tracheostomized infants. Tracheostomized patients showed higher comorbidities with hypoxic ischemic encephalopathy (odds ratio [OR] 10.98, P < 0.01), muscular disease (OR 10.95, P < 0.01), severe or moderate BPD (OR 7.79, P < 0.01), chromosomal abnormality (OR 4.43, P < 0.01) or sepsis (OR 1.78, P < 0.05) at hospital discharge than non‐tracheostomized patients.ConclusionWe demonstrated the non‐increasing rate in tracheostomy for VLBWIs and such cases were associated with an excellent survival in Japan. These data provide evidence that more attentive care must be practiced in order to reduce the pulmonary and neuromuscular burdens of VLBWIs at birth.
Contributions of dsRNases to differential RNAi efficiencies between the injection and oral delivery of dsRNA in Locusta migratoria
Authors: Song Huifang , Fan Yunhe , Zhang Jianqin , Cooper Anastasia MW , Silver Kristopher , Li Daqi , Li Tao , Ma Enbo , Zhu Kun Yan , Zhang Jianzhen 
Published: December 2018

AbstractBACKGROUNDThe efficiency of RNA interference (RNAi) varies considerably among different insect species, and there is growing evidence to suggest that degradation of double‐stranded (dsRNA) prior to uptake is an important factor that limits the efficiency of RNAi in insects. In Locusta migratoria, RNAi is highly efficient when dsRNA is delivered by injection, but not by feeding. However, detailed mechanisms causing such differential RNAi efficiency are still elusive.RESULTSWe identified and characterized the full‐length complementary DNAs (cDNAs) of two new dsRNA nuclease (dsRNase) genes from L. migratoria, which were named LmdsRNase1 and LmdsRNase4. Transcript analyses revealed that LmdsRNase1 and LmdsRNase4 were highly expressed in hemolymph with relatively lower expression in other tested tissues. Our study using heterologously expressed LmdsRNase1 and LmdsRNase4 fusion proteins showed that LmdsRNase1 can degrade dsRNA rapidly at an optimal pH of 5, whereas LmdsRNase4 had no activity at any of the pH values examined. In comparing the substrate specificity of the four LmdsRNases, we found that only LmdsRNase1 and LmdsRNase2 digested dsRNA; however, our experiments suggested that the physiological pH of hemolymph (7.0) suppresses LmdsRNase1 activity permitting significant dsRNA stability in this tissue. Conversely, the physiological pH of midgut juice (6.8) is ideal for LmdsRNase2 activity, resulting in degradation of dsRNA in midgut.CONCLUSIONThe physiological pH of different insect tissues or compartments can significantly alter the stability of dsRNA by influencing LmdsRNase activity in L. migratoria. Thus, new strategies to overcome such obstacles are expected to help implement RNAi‐based technologies for insect pest management. © 2018 Society of Chemical Industry
Stress tensor eigenvector following with next‐generation quantum theory of atoms in molecules
Authors: Li Jia Hui , Huang Wei Jie , Xu Tianlv , Kirk Steven R. , Jenkins Samantha 
Published: December 2018

AbstractThe eigenvectors of the electronic stress tensor have been identified as useful for the prediction of chemical reactivity because they determine the most preferred directions to move the bonds. A new 3–D vector based interpretation of the chemical bond that we refer to as the bond‐path framework set B provides a version of the quantum theory of atoms in molecules (QTAIM) beyond the minimum definition for bonding that is particularly suitable for understanding changes in molecular electronic structure that occur during reactions. We demonstrate that the most preferred direction for bond motion using the stress tensor corresponds to the most compressible direction and not to the least compressible direction as previously reported. We show the necessity for a directional approach constructed using the eigenvectors along the entire bond‐length and demonstrate the insufficiency of scalar measures for capturing the nature of the stress tensor within the QTAIM partitioning.
A theoretical study of the photoelectron spectra of dichloroketene with accurate computation of ionization energies via complete basis set limit extrapolation
Authors: Chang Jia‐Lin , Hsieh Jung‐Hang , Huang Yun‐Jhu , Chen Chiing‐Chang , Chang Mu‐Fong 
Published: December 2018

AbstractWe calculated the equilibrium geometries and harmonic vibrational frequencies of the ground state and five cationic states of dichloroketene using (TD‐)B3LYP, PBE0, and M06/M06‐2X approaches. The photoelectron spectra of dichloroketene were simulated by computing Franck‐Condon factors. The ionization energies were computed using the CCSD(T) approach with extrapolation to the complete basis set (CBS) limit. We propose two new CBS energy formulas (E = ECBS + Aexp(‐x) + B/(x−1)
n, n = 2 or 3) and compare the performance of different CBS approaches. A new ionic state of dichloroketene belonging to the Cs point group is reported. This state is identified as the first excited state of Cl2CCO+ having a double‐well potential‐energy curve along the CCO bending mode with a barrier height of 1.335 eV. The simulated photoelectron spectra are in agreement with the experiment. The vertical ionization energies calculated via spectral simulation are more accurate compared with those obtained at the ground‐state structure. Among the CBS formulas used, the proposed ansatz with n = 2 performs best, with a mean absolute error of 0.021 and 0.012 eV for the adiabatic and vertical ionization energies, respectively.
Surface functionalization of magnetic nanoparticles via palladium‐catalyzed Diels‐Alder approach
Authors: Maleki Ali , Taheri‐Ledari Reza , Soroushnejad Mahya 
Published: December 2018

AbstractMetal nanoparticles are currently being used as substantial catalysts for a number of classical chemical transformations. In contrast, performing novel biochemical reactions with the help of nano‐organocatalysts is highly underdeveloped area in chemical synthesis. In order to prepare an efficient nano‐organocatalyst, facilitated stable covalent bonding would be achieved by using Diels‐Alder reactions on the surface of magnetic nanoparticles. Herein, we report the synthesis of magnetic nano‐organocatalysts by using Fe3O4 nanoparticle coated by SiO2 network and functionalized with vinylsilane, as dienophile moiety of Diels‐Alder reactions. In this work, palladium(II) is used as an instrumental catalyst for Diels‐Alder reaction, as well.
Phosphine‐Promoted Amide Bond Formation Reactions from Carboxylic Acids and Tetraalkylthiuram Disulfides
Authors: Wu Zhiyong , Cheng Chuance , Tang Xiangting , Liu Shi , Xi Gaolei , Zhao Mingqin , Liu Pengfei 
Published: December 2018

AbstractAn efficient protocol for the straightforward synthesis of amides from readily available carboxylic acids and tetraalkylthiuram disulfides is presented. The reaction proceeds through direct cross‐coupling reactions promoted by catalytic amount of PPh3 in DMSO. This protocol is compatible with a wide variety of electron‐donating and ‐withdrawing acids, which shows its practical synthetic value in organic synthesis.
First monodontid cetacean (Odontoceti, Delphinoidea) from the early Pliocene of the north‐western Pacific Ocean
Authors: Ichishima Hiroto , Furusawa Hitoshi , Tachibana Makino , Kimura Masaichi 
Published: December 2018

AbstractMonodontids are among the most enigmatic cetaceans due to their scarcity in the fossil record. Previously, except for fragmentary materials, only three skulls were known from the pre‐Pleistocene; these came from the east coast of the Pacific and both east and west coasts of the Atlantic.Haborodelphis japonicus, a new early Pliocene monodontid cetacean from the north‐west Pacific, significantly expands the palaeobiogeographical extent of the ancestral monodontids. The new taxon differs from all other monodontids in the following character states: the robust postorbital process for the skull size; the short rostrum relative to the whole skull length; the anterior dorsal infraorbital foramina posterior to the level of the antorbital notch; the premaxillary foramen on the level of the antorbital notch; the dorsally gently convex premaxillary sac fossa; the palatines wedged into the maxillae anteriorly on the midline; and the presence of the clearly excavated posteromedial sulcus. Monodontids were almost certainly adapted to warmer waters than their living counterpartsDelphinapterus leucasandMonodon monoceros, both of which are confined to the high latitudes of the northern hemisphere. However, closer inspection (based mainly on fossil invertebrates) of the palaeoenvironments from which the monodontid fossils were produced, reveals that they may have preferred cooler conditions than previously thought. Due to the short climatic fluctuation cycles during the Pliocene in the northern hemisphere, and the increase of heterogeneity and regionality of the coastal environments, the dating of layers within a formation is critical for understanding palaeoenvironment in terms of the sea surface temperatures.
Radlastinduzierte Ermüdung bei Kranbahnträgern schwerer Hüttenkrane
Authors: Feldmann Markus , Citarelli Sandro 
Published: December 2018

AbstractIm Vergleich zu früheren Normen gelten in DIN EN 1993 für hochbeanspruchte Kranbahnträger wesentlich schärfere Kerbfallklassifizierungen, insbesondere im Bereich der Radlasteinleitung. Dies hat überaus starke wirtschaftliche Auswirkungen. So können die Änderungen nun bis zu einer Verdoppelung der Querschnittsdicken führen, z. B. Stegblechdicken von bis zu 80 mm oder darüber hinaus, deren K‐Nahtanschlüsse an den Flansch fertigungs‐ und überwachungstechnisch sehr aufwendig werden. Aufgrund der Massenzunahme ist häufig auch eine Verstärkung der Unterkonstruktion notwendig.Angeregt durch die Hüttenindustrie wurde daher angestrebt, Ergänzungen und Modifikationen der zugehörigen Kerbfälle im Eurocode 3 zu gestalten. Grundlage der Untersuchungen sind zahlreiche Kranbahnträger deutscher Stahlwerke, deren K‐Nähte am Steg‐Flanschanschluss nach jahrzehntelangem Betrieb intensiv schadensinspiziert wurden. Bei ausreichender Rückverfolgbarkeit der Lastgeschichte können die Träger als „Versuche im Bauwerk” interpretiert und ausgewertet werden.Die Untersuchungen, die von numerischen Simulationen begleitet wurden, zeigen, dass auch weit jenseits der Ausnutzbarkeit des Details „Radlasteinleitung” nach Eurocode 3 keine Ermüdungsschäden auftreten. Dies bestätigt die alten Regeln nach DIN 4132. Die Ergebnisse schließen somit eine Versuchslücke, die in früheren Normen durch Erfahrungswerte und Interpretation von Einzelergebnissen überbrückt wurde und rechtfertigen eine Änderung der Regeln in EC 3‐1‐9 Tabelle 8.10.
Das Netzquartier: die neue Zentrale des Netzbetreibers 50Hertz Transmission GmbH in Berlin
Authors: Fourmont Marcus , Prüfer Ralph , Meyer Dirk 
Published: December 2018

AbstractMit der Europacity wird im Herzen Berlins auf dem Gelände eines ehemaligen Bahnhofs ein neuer Stadtteil erschlossen. Gegenüber des Berliner Hauptbahnhofs entstehen Flächen für Wohnungen, Büro, Kunst und Einzelhandel. Für den Stromnetzbetreiber 50Hertz Transmission GmbH ist in der Europacity gegenüber des Total‐Towers die neue Firmenzentrale, das sogenannte Netzquartier, errichtet worden. Das Bürogebäude für ca. 650 Mitarbeiterinnen und Mitarbeiter ist das Deutschlandhauptquartier des Konzerns und integriert die TCC‐Ersatzleitwarte. Das Gesamtvorhaben wurde von DGNB und LEED als führende Nachhaltigkeitszertifizierungssysteme jeweils in Gold ausgezeichnet. Zudem erhielt das 50Hertz Netzquartier als erstes Gebäude weltweit die Auszeichnung DGNB Diamant. Im vorliegenden Beitrag wird auf die Besonderheiten eingegangen, die sich in Bezug auf die Berechnungen und Nachweise aus dem außergewöhnlichen Tragwerk ergeben. Weiterhin werden die besonderen Einflüsse aus dem lokalen Umfeld sowie die wesentlichen Aspekte der Herstellungstechnologie aufgezeichnet.
Seismic collapse analysis of high‐rise reinforced concrete frames under long‐period ground motions
Authors: Bai Yongtao , Guan Shaoyu , Lin Xuchuan , Mou Ben 
Published: December 2018

SummaryStructural damages associated with buckling of longitudinal reinforcing steel and crushing of concrete induce strength and stiffness degradation in reinforced concrete (RC) beams and columns. This paper presents a numerical investigation on earthquake‐induced damages and collapse of typical high‐rise RC buildings model incorporating strength degradation (SD) effects. In a simple finite‐element analysis program with the generalized stress fiber discretization, hysteretic constitutive models primarily dominate the inelastic behavior. Buckling of reinforcing steel and crushing of confined concrete are taken into accounted to the stress–strain relationship of fiber elements. The SD effect in components with small hoop ratio tends to amplify the seismic responses high‐rise RC moment‐resisting frames when the intensity of ground motions exceeds the design level. Buckling of steel rebar and crushing of concrete should be fully considered together with the P‐Δ effect for collapse simulations.