bluuebunny/crossref_metadata_2025 huggingface dataset:
BOOK AS A COMMUNICATION MEDIUM: USING BARCLAYS AYAKOROMA’S DANCE ON THE GRAVE TO DISCUSS SALIENT GENDER ISSUES
Authors: Guanah Seigha Jammy
Published: February 2019

Book is an effective communication tool that can be used to achieve different purposes, including gender equality; it is a complimentary medium to the mainstream media. Gender ine-quity is prevalent in the society, and this exposes women to a lot of discrimination that widens the dichotomy between them and their male counterparts, and invariably prevents the women-folk from participating and playing vital and supportive roles in developing the society. The agitation for gender equality and advocacy for women liberation is being carried out through various fronts, including books written in form of Drama, which is a very formidable force and a transformer of society; drama being a useful tool in national discourse and social commentary. Consequently, this study looked at Barclays Ayakoroma`s play (book), Dance on the grave, a drama that focuses on women`s agitation for a voice and equality with men in the society.This research work is anchored on the Muted Group Theory (MGT); and in order to pick and analyse the burning gender issues raised in the play, review and textual analyses were used as the qualitative research methods. In conclusion, this paper submitted that women are endowed with a lot of potentials that can contribute to the development of the society if they are not discriminated against, but that women must develop themselves in all aspects of life. It recommended, among others, that women should be protected from all forms of gender-based violence, and that more books that highlight the ills against women in the society should be written.
INDONESIA AND CENTRAL ASIA: ROMANTICIZING AUTHORITARIAN REGIME IN THE PAST?
Authors: Aviandy Mochamad
Published: February 2019

Even though countries in Central Asia and Indonesia seem to be unrelated, both actually have experienced authoritarian regime and implemented decentralization system after that regime collapsed. Nevertheless, decentralization along with non-authoritarian regime does not automatically bring the desired good result since a new authoritarian regime based on decentralization appears. As a result, the citizens long for the welfare of the centralism system. Before talking further about the comparison of both regions, it is better to have a good understanding of each region.
CHILDHOOD AND A CULTURE OF FEAR IN LEMONY SNICKET’S A SERIES OF UNFORTUNATE EVENTS
Authors: Annapurna Nur Aini , Hapsarani Dhita
Published: February 2019

This article is an excerpt from an undergraduate thesis of the same title which focuses on A Series of Unfortunate Events, a children‟s book series by Lemony Snicket. This thesis explores how a culture of fear shapes childhood, which is represented in the series. By using qualitative textual analysis the research discusses how the series represent the way childhood is shaped by a culture of fear through the depiction of various characters and social institutions in the novels. This research also explores the author‟s attempts in challenging the notion that children are vulnerable by analyzing the Baudelaires‟ identity and vulnerability. Results suggest that A Series of Unfortunate Events demonstrates ambivalence in the perception of childhood. Social institutions that should create a safe space for children tend to further perpetuate the culture of fear for them. Furthermore, children‟s vulnerability is often taken advantage of by adults for their own interests. Results also suggest that for children, their childhood is shaped by a culture of fear that is created and maintained by adults.
NETWORK LIBRARIANSHIP PARADIGM: BASED ON NETWORK SOCIETY THEORY
Authors: Al Muhdil Karim , Laksmi Laksmi , Evi Zakiyah
Published: February 2019

The 21st Century is marked with the development society that has close relationships with microelectronics network, network society. According to Manuell Castells, the network society is a society using microelectronic network as the basis of its activity. In this study, researchers sought to formulate a paradigm of network librarianship by building a common ontology which is then reflected by Manuel Castells network society theory. This study used a qualitative approach with philosophical approach. Documents are used for collecting the data and analysis. Researchers used hermeneutics approach by Hans Georg Gadamer. Research results showed that the unique characteristics of the network society found by Manuel Castells. As we known, the evolution chain of society had a serious implication for human being. Librarianship need to evaluate and rethink their based scientific paradigm to seek information phenomena being, especially for 21st century.
A modification of the leaf-bags method to assess spring ecosystem functioning: benthic invertebrates and leaf-litter breakdown in Vera Spring (Central Italy)
Authors: Cristiano Giovanni , Cicolani Bruno , Miccoli Francesco Paolo , Di Sabatino Antonio
Published: February 2019

The evaluation of leaf detritus processing (decomposition and breakdown) is one of the most simple and cost-effective method to assess the functional characteristics of freshwater ecosystems. However, in comparison with other freshwater habitats, information on leaf litter breakdown in spring ecosystems is still scarce and fragmentary. In this paper, we present results of the first application of a variant of the leaf-bags method to assess structure of macroinvertebrate assemblages and leaf-litter breakdown in a Central Apennines (Italy) cold spring which was investigated from July 2016 to October 2016. Notwithstanding the stable conditions of almost all hydrological and physico-chemical parameters, we found significant temporal differences in (i) % of mass loss of poplar leaves (ii) number of Ephemeroptera, Plecoptera and Trichoptera taxa, (iii) shredder and predator densities. We demonstrate that detritus processing in cold springs may be faster than or as fast as in warmer streams/rivers. Shredders activity and biocoenotic interactions, rather than temperature and nutrients load, were the main drivers of the process. A routine application of the modified leaf-bags may contribute to expand our knowledge on detritus processing in cold springs and may help to predict impacts of climate warming on freshwater ecosystem functioning.
Evolutionary insights ofBean common mosaic necrosis virusandCowpea aphid-borne mosaic virus
Authors: Wainaina James M. , Kubatko Laura , Harvey Jagger , Ateka Elijah , Makori Timothy , Karanja David , Boykin Laura M. , Kehoe Monica A.
Published: February 2019

Plant viral diseases are one of the major limitations in legume production within sub-Saharan Africa (SSA), as they account for up to 100% in production losses within smallholder farms. In this study, field surveys were conducted in the western highlands of Kenya with viral symptomatic leaf samples collected. Subsequently, next-generation sequencing was carried out to gain insights into the molecular evolution and evolutionary relationships of Bean common mosaic necrosis virus (BCMNV) and Cowpea aphid-borne mosaic virus (CABMV) present within symptomatic common bean and cowpea. Eleven near-complete genomes of BCMNV and two for CABMV were obtained from western Kenya. Bayesian phylogenomic analysis and tests for differential selection pressure within sites and across tree branches of the viral genomes were carried out. Three well–supported clades in BCMNV and one supported clade for CABMNV were resolved and in agreement with individual gene trees. Selection pressure analysis within sites and across phylogenetic branches suggested both viruses were evolving independently, but under strong purifying selection, with a slow evolutionary rate. These findings provide valuable insights on the evolution of BCMNV and CABMV genomes and their relationship to other viral genomes globally. The results will contribute greatly to the knowledge gap involving the phylogenomic relationship of these viruses, particularly for CABMV, for which there are few genome sequences available, and inform the current breeding efforts towards resistance for BCMNV and CABMV.
Genes of the undead: hibernation and death display different gene profiles
Authors: Hadj‐Moussa Hanane , Watts Alexander J. , Storey Kenneth B.
Published: February 2019

A degree of regulation continues into death according to post‐mortem transcriptome studies, which have identified ‘zombie genes’ that come alive hours and days after organismal death. We hypothesized that hibernation, representing the closest natural mammalian phenomenon to death, would display similar gene expression profiles. Exploring zombie genes using qPCR and available transcriptomic resources from multiple torpid tissues in 13‐lined ground squirrels showed little in common with gene profiles observed following death. Hibernators repress transcription, surviving only on the transcripts required during profound slowdowns of metabolic rate and of most physiological functions, therefore not requiring zombie gene expression that could be the cell's last resort during stress. This is the first study to explore zombie gene responses to a near‐death situation in a living system.
Enantioselective Hydrogenation of Ketones using Different Metal Complexes with a Chiral PNP Pincer Ligand
Authors: Garbe Marcel , Wei Zhihong , Tannert Bianca , Spannenberg Anke , Jiao Haijun , Bachmann Stephan , Scalone Michelangelo , Junge Kathrin , Beller Matthias
Published: February 2019

The synthesis of different metal pincer complexes coordinating to the chiral PNP ligand bis(2‐((2R,5R)‐2,5‐dimethyl‐phospholanoethyl))amine is described in detail. The characterized complexes with Mn, Fe, Re and Ru as metal centers showed good activities regarding the reduction of several prochiral ketones. Comparing these catalysts, the non‐noble metal complexes produced best selectivities not only for aromatic substrates, but also for different kinds of aliphatic ones leading to enantioselectivities up to 99% ee. Theoretical investigations elucidated the mechanism and rationalized the selectivity.

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Fluorierung von C‐H‐Bindungen: Entwicklungen und Perspektiven
Authors: Szpera Robert , Moseley Daniel F. J. , Smith Lewis B. , Sterling Alistair J. , Gouverneur Véronique
Published: February 2019

Dieser Aufsatz gibt einen aktuellen Überblick über Fluorierungen per C(sp2)‐H‐ und C(sp3)‐H‐Aktivierung. Übergangsmetallkatalysierte Methoden haben den regio‐ und stereoselektiven Einbau von Fluor an C(sp2)‐ und C(sp3)‐Zentren ermöglicht, indem die Reaktivität von Übergangsmetall‐Fluorid‐Komplexen in hohen Oxidationszuständen mit dirigierenden Gruppen kombiniert wurde. Die meisten Methoden beruhen auf der Verwendung elektrophiler Fluorierungsreagenzien. Allerdings wurden bereits Methoden mit einer nukleophilen Fluoridquelle in Gegenwart eines Oxidationsmittels publiziert. Kontrolle über die Reaktivität wurde mithilfe eines schwach koordinierenden Auxiliars im Substrat in Kombination mit einem externen Liganden erreicht. Komplementär zu übergangsmetallkatalysierten Verfahren ermöglichen Methoden auf Basis der Bildung radikalischer Intermediate undirigierte C(sp3)‐H‐Fluorierungen. Elektrophile N‐F‐Fluorierungsreagenzien bilden gewöhnlich die Grundlage für radikalische C‐H‐Fluorierungen, mit der Ausnahme einer MnIII‐katalysierten oxidativen C‐H‐Fluorierung mit Fluorid. Das Gebiet der nukleophilen C‐H‐Fluorierungen im späten Synthesestadium hat sich insgesamt weitaus langsamer entwickelt, weshalb sich die 18F‐Fluorierung von C‐H‐Bindungen noch im Anfangsstadium befindet.
Ein neutrales geminales frustriertes Zinn/Phosphor‐Lewis‐Paar
Authors: Holtkamp Philipp , Friedrich Felix , Stratmann Erik , Mix Andreas , Neumann Beate , Stammler Hans‐Georg , Mitzel Norbert W.
Published: February 2019

Das geminale frustrierte Lewis‐Paar (FLP) (F5C2)3SnCH2P(tBu)2 (2) wurde mittels der Reaktion von (F5C2)3SnCl mit LiCH2P(tBu)2 hergestellt. Es ist ungeladen und enthält eine extrem elektronegativ substituierte, aber relativ weiche (HSAB) Zinn‐Säurefunktion. Seine FLP‐artige Reaktivität zeigte es in Reaktionen mit einer Vielzahl kleiner Moleküle (CO2, SO2, CS2, PhNCO, HCl, (Ph3P)AuCl); in H/D‐Austauschexperimenten mit H2/D2‐Gemischen ist es jedoch unreaktiv. Es bindet reversibel CO2, was mit VT‐NMR‐Spektroskopie nachverfolgt wurde. Verbindung 2 und alle ihre Addukte wurden mittels Mehrkern‐NMR‐Spektroskopie, Elementaranalyse und Röntgenbeugungsexperimenten vollständig charakterisiert.
Curing characteristics and kinetics of EPDM and EOC compounds in co‐vulcanization as blend
Authors: Thitithammawong Anoma , Uthaipan Nattapon , Junhasavasdikul Banja , Nakason Charoen , Kalkornsurapranee Ekwipoo
Published: February 2019

Possibility of co‐vulcanization of ethylene octene copolymer (EOC) and ethylene propylene diene terpolymer (EPDM) molecules was studied by assessing the curing characteristic and crosslinking kinetics of EOC and EPDM compounds. Regarding curing, the curing characteristics, cure rate index, and the torque difference (MH− ML) of the EPDM compound are quite similar to those of the EOC compounds at the curing temperature of 180 °C, especially when the EOC octene comonomer content is 5.9 or 9.7 mol %. The kinetic parametersEaandkwere analyzed. The study showed that EOC with 9.7 mol % octene comonomer content is very suitable for blending with EPDM, as it has crosslinking kinetics similar to the EPDM. This observation confirms the possibility of chemical co‐crosslinking at EPDM–EOC interfaces, especially at the curing temperature of 180 °C. Differential scanning calorimetry and dynamic mechanical analysis were also used to assess interfacial crosslinking. The lowest activation energy of vulcanization is found for the EPDM/EOC blend with 9.7 mol % octene comonomer contents. Furthermore, chemical co‐crosslinking in combination with chain flexibility in the EPDM/EOC blend with 9.7 mol % octene comonomer contents give lower tanδat room temperature than for the blends with octene comonomer contents of 5.9 and 16.9 mol %. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47613.
An application of the Household Food Insecurity Access Scale to assess food security in rural communities of Nepal
Authors: Pandey Rishikesh , Bardsley Douglas K.
Published: February 2019

The state of food (in)security in rural communities of different ecological zones of the Kaligandaki Basin, Nepal, is assessed using a Household Food Insecurity Access Scale (HFIAS). The data were collected from 360 households using face‐to‐face interviews. The results show poor availability of food from subsistence production in the Middle‐Mountains and Trans‐Himalaya, whereas most households with sufficient purchasing power are able to access additional food from the market. Net food security is poor, with the highest level of insecurity in the Middle‐Mountains, followed by the Trans‐Himalaya and the Tarai. Although weaknesses were found in application of the HFIAS method due to respondent bias in subjective assessments of food insecurity in producer–consumer rural households, the method was found to be effective for rapidly incorporating utilization and stability elements into appraisals. Although not comprehensive, this approach has the potential to complement other forms of knowledge for designing targeted food policy in Nepal.
WARP: A Unique Extracellular Matrix Component of Cartilage, Muscle, and Endothelial Cell Basement Membranes
Authors: Fitzgerald Jamie
Published: February 2019

The von Willebrand factor A‐domain‐related protein (WARP) encoded by the VWA1 gene, is an orphan extracellular matrix protein that is expressed in a subset of ECM structures but whose function is poorly understood. Here, recent advances on understanding VWA1/WARP will be reviewed including analysis of VWA1 reporter and global knock‐out mice, interaction studies, and recent transcriptome analyses. Anat Rec, 2019. © 2019 Wiley Periodicals, Inc.
Preferential Face‐on and Edge‐on Orientation of Thiophene Oligomers by Rational Molecular Design
Authors: Ghosh Tanwistha , Nagasawa Shinji , Raveendran Neethi , Darshan Vibhu , Saeki Akinori , Nair Vijayakumar C.
Published: February 2019

Precise control over the supramolecular organization of organic semiconducting materials guiding to exclusive face‐on or edge‐on orientation is a challenging task. In the present work, we study the preferential packing of thiophene oligomers induced through rational molecular designing and self‐assembly. The acceptor–donor–acceptor‐type oligomers having 2‐(1,1‐dicyano‐methylene)rhodanine as acceptor (OT1) favored a face‐on packing, whereas that of functionalized with N‐octyl rhodanine (OT2) preferred an edge‐on packing as evident from 2D‐grazing incidence angle X‐ray diffraction, tapping‐mode atomic force microscopy (AFM) and Raman spectroscopy analyses. The oligomers exhibited anisotropic conductivity in the self‐assembled state as an outcome of the preferred orientation, revealed by the conducting AFM experiment.
Dynamische CO2‐Emissionsfaktoren für den deutschen Strom‐Mix
Authors: Wörner Patrick , Müller André , Sauerwein David
Published: February 2019

Die Energiewende hat in den letzten Jahren zu einer deutlichen Erhöhung des Anteils erneuerbarer Energien an der Stromerzeugung geführt. Einen essenziellen Beitrag zum Klimaschutz soll der Ausbau volatil einspeisender Windkraft‐ und Photovoltaikanlagen leisten, die im Vergleich zur konventionellen Stromerzeugung geringere spezifische Treibhausgasemissionen über den Lebenszyklus aufweisen. Im Kontext der ökologischen Bewertung zeigt sich die stetige Verbesserung des Strom‐Mix in einer Anpassung der CO2‐ bzw. Treibhausgasfaktoren für den Energieträger Strom. Die Bewertung innovativer und elektrifizierter Energieversorgungskonzepte kann jedoch mit statischen Emissionsfaktoren und auf Basis des Jahresendenergiebedarfs nicht zielführend vorgenommen werden. Deshalb wird eine Methodik vorgestellt, welche die CO2‐ und Treibhausgasemissionen des deutschen Strom‐Mix dynamisch in 15‐minütiger zeitlicher Auflösung für das Jahr 2017 abbildet. Hierfür werden frei verfügbare Stromerzeugungszeitreihen aufbereitet, der nationalen Strombilanz gegenübergestellt und in zeitvariable Emissionsfaktoren überführt. Ein Anwendungsbeispiel demonstriert, dass der über eine Jahresbilanz ermittelte CO2‐Ausstoß eines Gebäudes deutlich von den tatsächlichen Emissionen abweicht, die sich mithilfe zeitlich hoch aufgelöster CO2‐Faktoren ergeben. Dadurch zeigt sich im konkreten Fall eine Reduktion der Emissionen der Heizwärmeversorgung von etwa 12 Prozent.
Novel Old Yellow Enzyme Subclasses
Authors: Peters Christin , Frasson David , Sievers Martin , Buller Rebecca
Published: February 2019

Many drug candidate molecules contain at least one chiral centre, and consequently, the development of biocatalytic strategies to complement existing metal‐ and organocatalytic approaches is of high interest. However, time is a critical factor in chemical process development, and thus, the introduction of biocatalytic steps, even if more suitable, is often prevented by the limited availability of off‐the‐shelf enzyme libraries. To expand the biocatalytic toolbox with additional ene reductases, we screened 19 bacterial strains for double bond reduction activity by using the model substrates cyclohexanone and carvone. Overall, we identified 47 genes coding for putative ene reductases. Remarkably, bioinformatic analysis of all genes and the biochemical characterization of four representative novel ene reductases led us to propose the existence of two new Old Yellow Enzyme subclasses, which we named OYE class III and class IV. Our results demonstrate that although, on a DNA level, each new OYE subclass features a distinct combination of sequence motifs previously known from the classical and the thermophilic‐like group, their substrate scope more closely resembles the latter subclass.
Using big data to predict the likelihood of low falling numbers in wheat
Authors: Williams Richard M. , Diepeveen Dean A. , Evans Fiona H.
Published: February 2019

Background and objectives

Preharvest sprouting in wheat reduces quality and impacts farmer profitability. The international recognized falling number test can be used to measure that damage. Trying to understand the complex interactions that cause a reduction in wheat quality, equating to low falling number levels, is challenging. An alternative research approach to replicated experiments was to use a multiseason dataset of load‐by‐load delivery information to investigate whether correlations between falling number levels and 40 climate measurements could be identified.

Findings

This study used over 250,000 falling number data points from individual truckloads tested during seven harvests in Western Australia. The analyses identified relative humidity measured at the maximum temperature and daily temperature range as having consistent correlations with falling number levels over multiple seasons. Other climate measurements were also observed to have significant correlations with falling number, but these were less consistent within and between seasons.

Conclusions

The linkage of humidity and temperature range levels in the period before harvest commences to the occurrence of low falling number levels helps to further understand the complex interactions that change starch quality.

Significance and novelty

The findings demonstrate that value can be obtained from the use of a large, nonexperimentally designed dataset.
Pervaporation‐Assisted Esterification of Caproic Acid with Isobutanol in Conventional, In Situ, and Ex Situ Reactors
Authors: Chandane Vishal S. , Rathod Ajit P. , Wasewar Kailas L.
Published: February 2019

The factors that affect the pervaporation‐assisted esterification of caproic acid and isobutanol have been investigated in a batch reactor and compared with two different pervaporation reactors, in situ and ex situ reactors, with different configurations. The operating process parameters of the pervaporation modules can be adjusted to optimize the performance, which improves the conversion of reactants and reduces the operating costs. The performances of the reactors have been extensively studied and the membrane selectivity has been investigated in terms of the flux of individual reaction species. The mass transfer limitation of both pervaporation reactors was studied and suitably eliminated. In addition, the performance of the pervaporation reactors was investigated by evaluating the ratio of water removal rate to the water production rate.
Revisiting a Historical Concept by Using Quantum Crystallography: Are Phosphate, Sulfate and Perchlorate Anions Hypervalent?
Authors: Fugel Malte , Malaspina Lorraine A. , Pal Rumpa , Thomas Sajesh P. , Shi Ming W. , Spackman Mark A. , Sugimoto Kunihisa , Grabowsky Simon
Published: February 2019

There are many examples of atoms in molecules that violate Lewis’ octet rule, because they have more than four electron pairs assigned to their valence. These atoms are referred to as hypervalent. However, hypervalency may be regarded as an artifact arising from Lewis’ description of molecules, which is based on the assumption that electrons are localized in two‐center two‐electron bonds and lone pairs. In the present paper, the isoelectronic phosphate (PO43−), sulfate (SO42−) and perchlorate (ClO4−) anions were examined with respect to the concept of hypervalency. Lewis formulas containing a hypervalent central atom exist for all three anions. Based on X‐ray wavefunction refinements of high‐resolution X‐ray diffraction data of representative crystal structures (MgNH4PO4⋅6 H2O, Li2SO4⋅H2O, and KClO4), complementary bonding analyses were performed. In this way, experimental information from the new field of quantum crystallography validate long‐known facts, or refute long‐standing misunderstandings. It is shown that the P−O and S−O bonds are highly polarized covalent bonds and, thus, the increase in the valence population following three‐center four‐electron bonding is not sufficient to yield hypervalent phosphorus or sulfur atoms, respectively. However, for the highly covalent Cl−O bond, most bonding indicators imply a hypervalent chlorine atom.
Thermochemische Depolymerisation von Lignin zur Gewinnung von Aromaten
Authors: Zurbel Alexander , Kaiser Doreen , Hippmann Sebastian , Bertau Martin
Published: February 2019

Zur Entwicklung einer effizienten Verwertungsstrategie von Lignin wurde ein Kraft‐Lignin mit sub‐ und überkritischem Wasser umgesetzt. Dabei wurden die Einflüsse von Temperatur und Phasenzustand der Lösungsmittel auf das via GC‐MS detektierte Produktspektrum untersucht. Die grundlegenden Erkenntnisse sollen erste Ansätze für Applikationsmöglichkeiten der biomassebasierten aromatischen Grundstoffchemie liefern.
Haploinsufficiency of UNC13D increases the risk of lymphoma
Authors: Löfstedt Alexandra , Ahlm Clas , Tesi Bianca , Bergdahl Ingvar A. , Nordenskjöld Magnus , Bryceson Yenan T. , Henter Jan‐Inge , Meeths Marie
Published: February 2019

Background

Experimental models have demonstrated that immune surveillance by cytotoxic lymphocytes can protect from spontaneous neoplasms and cancer. In humans, defective lymphocyte cytotoxicity is associated with the development of hemophagocytic lymphohistiocytosis, a hyperinflammatory syndrome. However, to the best of the authors’ knowledge, the degree to which human lymphocyte cytotoxicity protects from cancer remains unclear. In the current study, the authors examined the risk of lymphoma attributable to haploinsufficiency in a gene required for lymphocyte cytotoxicity.

Methods

The authors exploited a founder effect of an UNC13D inversion, which abolishes Munc13‐4 expression and causes hemophagocytic lymphohistiocytosis in an autosomal recessive manner. Within 2 epidemiological screening programs in northern Sweden, an area demonstrating a founder effect of this specific UNC13D mutation, all individuals with a diagnosis of lymphoma (487 patients) and matched controls (1844 controls) were assessed using polymerase chain reaction for carrier status.

Results

Among 487 individuals with lymphoma, 15 (3.1%) were heterozygous carriers of the UNC13D inversion, compared with 18 controls (1.0%) (odds ratio, 3.0; P = .002). It is interesting to note that a higher risk of lymphoma was attributed to female carriers (odds ratio, 3.7; P = .004).

Conclusions

Establishing a high regional prevalence of the UNC13D inversion, the authors have reported an overrepresentation of this mutation in individuals with lymphoma. Therefore, the results of the current study indicate that haploinsufficiency of a gene required for lymphocyte cytotoxicity can predispose patients to lymphoma, suggesting the importance of cytotoxic lymphocyte‐mediated surveillance of cancer. Furthermore, the results of the current study suggest that female carriers are more susceptible to lymphoma.
Selective Electrocatalytic H2O2 Generation by Cobalt@N‐Doped Graphitic Carbon Core–Shell Nanohybrids
Authors: Lenarda Anna , Bevilacqua Manuela , Tavagnacco Claudio , Nasi Lucia , Criado Alejandro , Vizza Francesco , Melchionna Michele , Prato Maurizio , Fornasiero Paolo
Published: February 2019

Electrocatalytic oxygen reduction (ORR) is an emerging synthetic strategy to prepare H2O2 in a sustainable fashion. N‐doped graphitic carbon with embedded cobalt nanoparticles was selected as an advanced material able to selectively trigger the ORR to form H2O2 with a faradaic efficiency of almost 100 % at very positive applied potentials. The production of H2O2 proceeded with high rates as calculated by bulk electrolysis (49 mmol g−1 h−1) and excellent current densities (≈−0.8 mA cm−2 at 0.5 V vs. reversible hydrogen electrode). The totally selective behavior depended on the combination of concomitant material features, such as the textural properties, the nature of the metal, the distribution of N moieties, the acidic environment, and the applied potential.
Vegetation and location of water inflow affect evaporation in a subtropical wetland as indicated by the deuterium excess method
Authors: Zhai Lu , Wang Xin , Wang Peng , Miralles‐Wilhelm Fernando , Sternberg Leonel da Silveira Lobo
Published: February 2019

Evaporation represents a principal form of water loss from water bodies, but quantifying evaporation with transpiring vegetation is challenging, owing to the difficulties in disentangling evaporation from transpiration. As the two processes have different effects on water isotope signatures (i.e., oxygen and hydrogen stable isotope ratios expressed by δ18O and δ2H), we used both the δ18O and δ2H values of water samples to calculate their deuterium excess (d) values, which are proportionate to fraction of evaporation loss (Ef) of water being sampled. Comparing with a single isotope method, the d method holds the advantage that it does not require knowledge of the initial isotope ratios of source water. Limitations of the d method, for example, effects of prior‐evaporation of water before entering water bodies, can be checked and corrected. The sampling locations throughout our study site differed in vegetation coverage, water depth, and distance to water inflow (or discharge gate of water inflow), which are three important factors in water management. This sampling design offered us a unique opportunity to quantify the influences of the above three factors on Ef. We found the following: (1) There was a spatiotemporal pattern in δ18O distribution. (2) The Ef was negatively related to the vegetation coverage, positively related to distance to the water source inflow but nonsignificantly related to water depth. Therefore, vegetation and distance to the water inflow are two important considerations for the control of evaporative water loss, and evaporation calculated by the d method can lead to more informed water management.
Investigating old‐growth ponderosa pine physiology using tree‐rings, δ13C, δ18O, and a process‐based model
Authors: Ulrich Danielle E. M. , Still Christopher , Brooks J. Renée , Kim Youngil , Meinzer Frederick C.
Published: February 2019

In dealing with predicted changes in environmental conditions outside those experienced today, forest managers and researchers rely on process‐based models to inform physiological processes and predict future forest growth responses. The carbon and oxygen isotope ratios of tree‐ring cellulose (δ13Ccell, δ18Ocell) reveal long‐term, integrated physiological responses to environmental conditions. We incorporated a submodel of δ18Ocell into the widely used Physiological Principles in Predicting Growth (3‐PG) model for the first time, to complement a recently added δ13Ccell submodel. We parameterized the model using previously reported stand characteristics and long‐term trajectories of tree‐ring growth, δ13Ccell, and δ18Ocell collected from the Metolius AmeriFlux site in central Oregon (upland trees). We then applied the parameterized model to a nearby set of riparian trees to investigate the physiological drivers of differences in observed basal area increment (BAI) and δ13Ccell trajectories between upland and riparian trees. The model showed that greater available soil water and maximum canopy conductance likely explain the greater observed BAI and lower δ13Ccell of riparian trees. Unexpectedly, both observed and simulated δ18Ocell trajectories did not differ between the upland and riparian trees, likely due to similar δ18O of source water isotope composition. The δ18Ocell submodel with a Peclet effect improved model estimates of δ18Ocell because its calculation utilizes 3‐PG growth and allocation processes. Because simulated stand‐level transpiration (E) is used in the δ18O submodel, aspects of leaf‐level anatomy such as the effective path length for transport of water from the xylem to the sites of evaporation could be estimated.
NHC Nickel Catalyzed Hiyama‐ and Negishi‐Type Cross‐Coupling of Aryl Fluorides and Investigations on the Stability of Nickel(II) Fluoroaryl Alkyl Complexes
Authors: Kuntze‐Fechner Maximilian W. , Kerpen Christoph , Schmidt David , Häring Mathias , Radius Udo
Published: February 2019

The reactivity of [Ni(iPr2Im)4(µ‐COD)] 1 (iPr2Im = 1,3‐diisopropyl‐imidazolin‐2‐ylidene, COD = 1,4‐cyclooctadiene) in Hiyama‐ and Negishi‐type cross‐coupling reactions as well as the synthesis of several novel nickel fluoroaryl alkyl complexes is reported. Hiyama coupling of 1.1 equiv. perfluoroaromatics and 1 equiv. PhSi(OR)3 (R = Me, Et) with 5 mol‐% of 1 as catalyst leads to the C–C coupling product ArF–Ph in good to fair yields. In presence of the additive NMe4F alkoxy transfer from PhSi(OR)3 to the perfluoroarene occurs to yield ArF–OR and PhSiF(OR)2. Negishi cross‐coupling between C6F6 or C7F8 (1 equiv.), diorganozinc reagents [ZnR2] (R = Me, Et) (2.1 equiv.) and 5 mol‐% 1 as the catalyst in toluene at 115 °C leads to ArF–R only in traces. However, NMR experiments revealed that nickel alkyl complexes are readily formed from the reaction of trans‐[Ni(iPr2Im)2(F)(ArF)] with [ZnR2] (R = Me, Et). In course of these investigations, a series of novel nickel alkyl complexes trans‐[Ni(iPr2Im)2(R)(ArF)] (R = Me, ArF = C6F5 2, C7F7 3, C12F9 4; R = Et, ArF = C6F5 5, C7F7 6, C12F9 7) have been synthesized in stoichiometric reactions starting from trans‐[Ni(iPr2Im)2(F)(ArF)] (ArF = C6F5, C7F7, C12F9) and [ZnR2] (R = Me, Et) in thf at –78 °C. As these nickel alkyl complexes 2–7 are stable at room temperature in solution for several days with respect to reductive elimination, their thermal stability was investigated. Heating trans‐[Ni(iPr2Im)2(Me)(C6F5)] 2 for 24 hours at 100 °C leads to 91 % unreacted complex 2 and only traces of reductive elimination product, i.e. C6F5Me, are formed. Furthermore, the nickel ethyl complex trans‐[Ni(iPr2Im)2(Et)(C6F5)] 5 is also very stable, even with respect to β‐hydride elimination. After heating this complex to 100 °C for 24 hours there is still 26 % unreacted 5 left.
Ammonia and Hydrazine from Coordinated Dinitrogen by Complexes of Iron(0)
Authors: Field Leslie D. , Li Hsiu L. , Dalgarno Scott J. , McIntosh Ruaraidh D.
Published: February 2019

The iron(0) dinitrogen complexes [Fe(N2)(PP3R)] (PP3R = P(CH2CH2PR2)3, R = Ph, iPr, Cy) were synthesized by reduction of the precursor chloro complexes with potassium graphite. On reaction with triflic acid, [Fe(N2)(PP3R)] complexes afforded ammonia and hydrazine in yields of up to 23 and 16 % respectively. The complex [Fe(N2)(PP3Ph)] which has only been previously synthesized in situ, has now been isolated and fully characterized by 15N NMR spectroscopy and by X‐ray crystallography.
Synthesis of Amino‐ and Hydroxymethyl Benzoxaboroles: Prominent Scaffolds for Further Functionalization
Authors: Fuscaldo Rodrigo S. , Vontobel Pedro H. V. , Boeira Eduam O. , Moro Angélica V. , Costa Jessie S. da
Published: February 2019

Herein, we describe the development of a short, simple, and efficient synthesis of amino‐ and hydroxymethyl‐substituted benzoxaboroles. The key step in our strategy was the early stage incorporation of the boron by the borylation of an aniline. The formed boronates were then elaborated to the final products in two additional steps, usually in good yields. The synthetic sequence was amenable to be performed on a preparative scale and 4‐amino benzoxaborole 4b and 6‐hydroxymethyl benzoxaborole 10c have been prepared, without any significant decrease in the overall yield. The amino and hydroxymethyl present at the molecules are useful for further elaboration and/or conjugation to bioactive molecules and therefore we believe that this method should be useful in the development of new compounds for Medicinal Chemistry.
Rare‐Earth‐Metal‐Catalyzed Kinetic Resolution of Chiral Aminoalkenes via Hydroamination: The Effect of the Silyl Substituent of the Binaphtholate Ligand on Resolution Efficiency
Authors: Nguyen Hiep N. , Hultzsch Kai C.
Published: February 2019

The kinetic resolution of α‐substituted aminopentenes via intramolecular hydroamination was investigated using various 3,3′‐silyl‐substituted binaphtholate yttrium catalysts. High efficiencies in the kinetic resolution were observed for methyl‐, benzyl‐, and phenyl‐substituted substrates utilizing the cyclohexyldiphenylsilyl‐substituted catalyst 2c with resolution factors reaching as high as 90(5) for hex‐5‐en‐2‐amine (3a). Kinetic analysis of the enantioenriched substrates with the matching and mismatching catalyst revealed that the efficiency of catalyst 2c benefits significantly from a favorable Curtin–Hammett pre‐equilibrium and by a large kfast/kslow ratio. Other binaphtholate catalysts were less efficient due to a less favorable Curtin–Hammett pre‐equilibrium, which often favored the mismatching substrate‐catalyst combination. Cyclization of the matched substrate proceeds generally with large trans‐selectivity, whereas the trans/cis‐ratio for mismatched substrates is significantly diminished, favoring the cis‐cyclization product isomer in some instances.
New Insights into the Reaction Capabilities of Ionic Organic Bases in Cu‐Catalyzed Amination
Authors: Lo Quintin A. , Sale David , Braddock D. Christopher , Davies Robert P.
Published: February 2019

The application of ionic organic bases in the copper‐catalyzed amination reaction (Ullmann reaction) has been studied at room temperature, with sub‐mol‐% catalyst loadings, and with more challenging amines at elevated temperatures. The cation present in the base has been shown to have little effect on the reaction at standard catalyst and ancillary ligand loadings, whereas the choice of anion is crucial for good reactivity. A substrate scope carried out at room temperature with the best performing bases, TBAM and TBPM, showed both bases to be highly effective under these mild reaction conditions. Moreover, under sub‐mol % catalyst loadings and room temperature conditions, TBPM gave good to excellent yields for a number of different amines and functionalized aryl iodides (14 examples). However, reactions involving more challenging amines gave little or no yield. By using more forceful conditions (120 °C) moderate to excellent yields of cross‐coupled products containing more challenging amines was achievable using TBPM and to a lesser extent with TBAM. As part of this work a study on the stability of the organic bases at 120 °C was undertaken. TBAM is shown to decompose to give nBu3N and mono‐butylmalonate at higher temperatures, and this can be correlated to a decrease in performance in the coupling reaction. The phosphonium cations in TBPM did not undergo analogous reactivity but were shown instead to experience some degree of deprotonation at the α‐CH2 to generate phosphonium ylides. This however did not lead to a significantly degradation in the activity of the TBPM in the cross‐coupling reaction.
The “Flint Depot” of prehistoric northern Israel: Comprehensive geochemical analyses of flint extraction and reduction complexes and implications for provenance studies
Authors: Finkel Meir , Barkai Ran , Gopher Avi , Tirosh Ofir , Ben‐Yosef Erez
Published: February 2019

Recent research has demonstrated that the Eocene Timrat formation in northeastern Israel, which appears as an extensive land “strip” west of and parallel to the Rift Valley, was a major source of prehistoric flint. This supposition is supported by three large‐scale extraction and reduction (E&R) complexes identified within this region, which offer direct evidence of intense Lower and Middle Palaeolithic exploitation and limited Neolithic/Chalcolithic activities. Here, we present a first comprehensive overview of this “industrial strip” and of its E&R complexes (Nahal Dishon, Mt. Achbara, and Sede Ilan), demonstrating that these production areas were used mainly for the manufacture of large‐volume items such as Lower Palaeolithic hand axes, Middle Palaeolithic Levallois cores, and Neolithic/Chalcolithic axes/adzes. Furthermore, we integrate information from recently published field studies and lithic analyses with new intercomplex and intracomplex inductively coupled plasma mass spectrometry (inductively coupled plasma (ICP)‐MS) analyses of flint debitage. The relatively large number of analysed samples (
n = 69) constitutes the first robust reference database for provenance studies of this E&R “strip.” The potential contribution for provenance studies is demonstrated by a detailed ICP‐MS comparison drawn between specific extraction and reduction localities within the Dishon complex and flint tools found in six occupation sites located up to 20 km from the sources. The detailed geochemical study also yielded methodological insights regarding challenges associated with flint heterogeneity and patination effects.
Emission mechanism and reduction countermeasures of agricultural greenhouse gases – a review
Authors: Liu Ying , Tang Haiying , Muhammad Aamer , Huang Guoqin
Published: February 2019

Global climate change, especially global warming, has caused widespread concern in the international community. Increasing concentrations of greenhouse gases, such as carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) produced by human activities, are the main cause of global warming. According to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), agriculture is an important source of greenhouse gas emissions, so reduction of such emissions is of great significance to global climate change. There are many driving factors affecting agricultural greenhouse gas emissions. These factors are interrelated and interact with each other, so the mechanism of action is complicated. In this paper, first, the driving factors of agricultural greenhouse gas emissions and emission sources are introduced. Second, the factors influencing agricultural greenhouse gas emissions are analyzed and summarized. Third, to clarify the factors influencing agricultural greenhouse gas emissions, measures and countermeasures for reducing greenhouse gas emission are proposed, discussed, and compared. Finally, action mechanisms, action pathways, and long‐term reduction measures for agricultural greenhouse gases are described. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.
Evaluating contemporary pain management practices in thyroid and parathyroid surgery: A national survey of head and neck endocrine surgeons
Authors: Ferrell Jay K. , Singer Michael C. , Farwell D. Gregory , Stack Brendan C. , Shindo Maisie
Published: February 2019

Background

There is currently a lack of evidence‐based guidelines regarding postoperative opioids after thyroid and parathyroid surgery. This study aimed to objectively characterize contemporary postoperative pain management practices via a national survey of head and neck endocrine surgeons.

Methods

A standardized electronic survey was distributed to the membership of the American Head and Neck Society's Endocrine section.

Results

A total of 102 surgeons completed the survey representing a 34% response rate. In all, 65.7% of respondents utilize opioids with wide variations in the total morphine equivalents prescribed. Practice environment (χ2 = 10.0; P = 0.04) and performing preoperative pain counseling (χ2 = 9.7; P = 0.002) were significantly associated with a decreased likelihood of prescribing postoperative opioids. Utilization of non‐opioid pain management strategies was common and significantly associated with performing outpatient surgery (χ2 = 6.2; P = 0.013) and preoperative pain counseling (χ2 = 4.5; P = 0.034).

Conclusions

Pain management practice patterns vary significantly among head and neck endocrine surgeons which further emphasize the need for evidence‐based guidelines.
Hand as hammer: A comprehensive review of biomechanical studies related to occupational hand strikes
Authors: Hausmanninger Lukas , Komnik Igor , Potthast Wolfgang
Published: February 2019

A growing number of workers in modern automotive assembly plants are confronted with occupational tasks involving repeated high‐impact hand strikes. Such repetitive physical workloads account for diseases of soft tissues or musculoskeletal disorders in the hand, wrist, or entire upper body. The purpose of this review was to identify and discuss the most pertinent occupational and physiological investigations concerning such hand strikes with particular emphasis on the biomechanical parameters examined. Articles were drawn from four databases to identify publications about occupational hand strikes. First, studies were selected that evaluated hand impact loads measured with the help of force measurement devices. For a deeper understanding of biomechanical factors regarding hand impacts, the scope of the search was extended to include ancillary studies about impacts on wrists or elbows. Overall, 945 abstracts were screened, and five full‐text articles were included in the final review. In addition, 34 ancillary articles about impact stress on the hand–arm complex were discussed because of positive relations between high forces, repetition rates or acceleration, and progressing stress in the hand–arm complex identified in studies about critical biomechanical load limits, in the field of fall arrests and sports, i.e. tennis. Furthermore, studies about effective arm movements and body postures during hand strikes as used in martial arts were reviewed. Although certain biomechanical parameters are both known and well documented, studies available at present cannot sufficiently account for specific disorders in the wrist or arm that are triggered by occupational hand strikes.
Label‐Free Quantification of 5‐Azacytidines Directly in the Genome
Authors: Schiffers Sarah , Wildenhof Thomas M. , Iwan Katharina , Stadlmeier Michael , Müller Markus , Carell Thomas
Published: February 2019

Azacytidines (AzaC and AzadC) are clinically relevant pharmaceuticals that operate at the epigenetic level. They are integrated into the genome as antimetabolites to block DNA methylation events. This leads to a reduction of the 5‐methyl‐2′‐deoxycytidine (m5dC) level in the genome, which can activate epigenetically silenced genes. Because of the inherent chemical instability of Aza(d)Cs, their incorporation levels in DNA and RNA are difficult to determine, which hinders correlation of therapeutic effects with incorporation and removal processes. Existing methods involve radioactive labeling and are therefore unsuitable to monitor levels from patients. We report here a new direct chemical method that allows absolute quantification of the levels of incorporated AzaC and AzadC in both RNA and DNA. Furthermore, it clarifies that Aza(d)C accumulates to high levels (up to 12.9 million bases per genome). Although RNA‐based antimetabolites are often 2′‐deoxygenated in vivo and incorporated into DNA, for AzaC we see only limited incorporation into DNA. It accumulates predominantly in RNA where it, however, only leads to insignificant demethylation.
An optical study of drug resistance detection in endometrial cancer cells by dynamic and quantitative phase imaging
Authors: Yao Tian , Cao Runyu , Xiao Wen , Pan Feng , Li Xiaoping
Published: February 2019

Platinum chemosensitivity detection plays a vital role during endometrial cancer treatment because chemotherapy responses have profound influences on patient's prognosis. Although several methods can be used to detect drug resistance characteristics, studies on detecting drug sensitivity based on dynamic and quantitative phase imaging of cancer cells are rare. In this study, digital holographic microscopy was applied to distinguish drug‐resistant and nondrug‐resistant endometrial cancer cells. Based on the reconstructed phase images, temporal evolutions of cell height (CH), cell projected area (CPA) and cell volume were quantitatively measured. The results show that change rates of CH and CPA were significantly different between drug‐resistant and nondrug‐resistant endometrial cancer cells. Furthermore, the results demonstrate that morphological characteristics have the potential to be utilized to distinguish the drug sensitivity of endometrial cancer cells, and it may provide new perspectives to establish optical methods to detect drug sensitivity and guide chemotherapy in endometrial cancer.