bluuebunny/crossref_metadata_2025 huggingface dataset:
Management of Rice Caseworm (Nymphula depunctalis) in Rice in Eastern Region of Uttar Pradesh, India
Authors: Patel Gopi , Chauhan Saroj , Kumar Ritesh , Mourya Pradumn Kumar
Published: August 2024

The present investigationwas carried out at Heera Puri research field, Institute of Agriculture and Natural Sciences, Deen Dayal Upadhyaya Gorakhpur University, District Gorakhpur during Kharif, 2023. In the kharif season of 2023, there was a rice crop, the relative effectiveness of six insecticides viz. flubendiamide 39.35% SC, NSKE 5%, cartap hydrochloride 50% SP, spinosad 45 SC, neem oil 5%, and emamectin benzoate 5% SC with control was assessed in the field against the rice caseworm. Spinosad 45 SC (3.95 %) was found to be the most effective insecticide treatment among all pesticides for controlling the rice caseworm, as it has recorded the lowest infestation. The second-best treatment was emamectin benzoate 5% SC (4.07 %), followed by flubendiamide 39.35% SC (4.21%), cartap hydrochloride 50% SP (4.32%), Neem oil 5% (4.75%), and NSKE 5% (4.85%). The significantly higher grain yield was obtained in Spinosad 45 SC (55.94 q/ha) treated plots which are followed by emamectin benzoate 5% SC (54.19%), flubendiamide 39.35% SC (54.02 q/ha), cartap hydrochloride 50% SP (53.21 q/ha), neem oil 5% (52.36 q/ha) and NSKE 5% (51.27 q/ha). The economics of various treatments based on net profit and cost of plant protection revealed that the highest cost: benefit ratio Spinosad 45 SC (1:4.47) followed by Emamectin benzoate 5% SC (1:3.96), followed by Cartap hydrochloride 50% SP (1: 2.06), Neem oil 5% (1: 1.25), NSKE 5% (1: 1.23) and the lowest cost-benefit ratio was observed in Flubendiamide 39.35% SC (1: 0.88).
Impact of Delay in ZigBee WSNs for Smart Home Applications
Authors: Baqer Naseem Kadhim , Harbi Yahya Jasim , Al-Asady Heba Abdul-Jaleel
Published: August 2024

A smart home is a comprehensive integration system that employs technologies such as computers, structured wiring and network communication to interconnect indoor subsystems, home appliances and electrical devices. WSNs play a crucial role in the functionality of smart homes. In this study, the IEEE 802.15.4/ ZigBee wireless communication standard was applied. Compared to other wireless communication standards, it offers a number of benefits, such as low battery and power consumption. Delays in ZigBee-based WSNs used in smart homes can be attributed to various factors, including network configuration, routing efficiency, device availability, sensor reporting intervals and power management. By optimizing the network parameters of ZigBee-based WSNs with concomitant reduction in inherent delays, it is possible to enhance the performance and user experience of smart home systems. Furthermore, the influence of coordinators and routers on ZigBee-based WSN delays is thoroughly examined and discussed. The results indicate that while adding more sensors to the WSN produces an extra delay, by contrast, the addition of an extra coordinator reduces the delay. Finally, the presence of a router in the WSN does not have a large impact on the delay.
Investigating plasma motion of magnetic clouds at 1 AU through a velocity‐modified cylindrical force‐free flux rope model
Authors: Wang Yuming , Zhou Zhenjun , Shen Chenglong , Liu Rui , Wang S.
Published: February 2015

Magnetic clouds (MCs) are the interplanetary counterparts of coronal mass ejections (CMEs), and usually modeled by a flux rope. By assuming the quasi‐steady evolution and self‐similar expansion, we introduce three types of global motion into a cylindrical force‐free flux rope model and developed a new velocity‐modified model for MCs. The three types of the global motion are the linear propagating motion away from the Sun, the expanding, and the poloidal motion with respect to the axis of the MC. The model is applied to 72 MCs observed by Wind spacecraft to investigate the properties of the plasma motion of MCs. First, we find that some MCs had a significant propagation velocity perpendicular to the radial direction, suggesting the direct evidence of the CME's deflected propagation and/or rotation in interplanetary space. Second, we confirm the previous results that the expansion speed is correlated with the radial propagation speed and most MCs did not expand self‐similarly at 1 AU. In our statistics, about 62%/17% of MCs underwent a underexpansion/overexpansion at 1 AU and the expansion rate is about 0.6 on average. Third, most interestingly, we find that a significant poloidal motion did exist in some MCs. Three speculations about the cause of the poloidal motion are therefore proposed. These findings advance our understanding of the MC's properties at 1 AU and the dynamic evolution of CMEs from the Sun to interplanetary space.
Low‐frequency waves within isolated magnetic clouds and complex structures: STEREO observations
Authors: Siu‐Tapia A. , Blanco‐Cano X. , Kajdic P. , Aguilar‐Rodriguez E. , Russell C. T. , Jian L. K. , Luhmann J. G.
Published: February 2015

Complex Structures (CSs) formed by the interaction of magnetic cloud (MC)‐like structures with other transients (e.g., another MC, a stream interaction region, or a fast stream of solar wind) were frequently observed in the interplanetary space by STEREO spacecraft during the solar minimum 23 and the rising phase of the solar cycle 24. Here we report the presence of low‐frequency waves (LFWs) inside some isolated MCs (IMCs) and inside the CSs observed by STEREO during such period (2007–2011). It is important to study in detail the properties of waves in space plasmas since particle distribution functions can be modified by wave‐particle interactions. We compare wave characteristics within IMCs with those waves observed inside CSs. Both left‐handed (LH) and right‐handed (RH), near‐circularly polarized, transverse and almost parallel‐propagating LFWs (around the proton cyclotron frequency) were sporadically observed inside both IMCs and CSs. In contrast, compressive mirror‐mode waves (MMs) were observed only within CSs. We studied local plasma conditions inside the IMCs and CSs to gain insight about wave origin: most of the MMs within CSs were observed in regions with enhanced plasma beta (β>1); the majority of the LH waves were found in low beta plasmas (β<1), and the RH waves were predominantly observed at moderate betas (0.4<β≤2). These observations are in agreement with linear kinetic theory predictions for the growth of the mirror, the LH ion cyclotron, and the RH ion firehose instability, respectively. It is possible that the waves were generated locally inside the IMCs and CSs via temperature anisotropies. The plasma beta enhancements that were frequently observed inside the CSs may be the result of compressions and heating taking place inside the interacting structures.
Role of neutral wind in the performance of artificial neural‐network based TEC models at diverse longitudes in the low latitudes
Authors: Sur D. , Ray S. , Paul A.
Published: February 2015

The equatorial ionosphere is characterized by (i) large values of total electron content (TEC) and sharp latitudinal gradients of TEC, (ii) steep temporal variation of TEC, (iii) large diurnal variation of TEC, and (iv) postsunset secondary enhancement of TEC. These features cause major limitations in the accuracy of standard ionospheric TEC models in this region. Three artificial neural‐network (ANN) based models have been developed based on real‐time low‐latitude TEC data along 77°E, 88°E, and 121°E longitudes in the region between the magnetic equator and locations beyond the northern crest of equatorial ionization anomaly to predict the vertical TEC values. ANN models have shown more accurate predictions than other standard ionospheric TEC models like International Reference Ionosphere, Parameterized Ionospheric Model, and NeQuick. The effects of the neutral wind in the variation of TEC are significant and have been incorporated as inputs to these ANN models. The outputs with neutral wind incorporated shows better correspondence with measured TEC than the models without neutral wind inputs. The longitudinally separated models have been used to find any longitudinal differences in TEC along equatorial regions. The causes behind the longitudinal differences in TEC and its diurnal variations in these regions have been explained in terms of the geomagnetic declination and inclination angles along with the role of zonal wind.
The postsunset vertical plasma drift and its effects on the generation of equatorial plasma bubbles observed by the C/NOFS satellite
Authors: Huang Chao‐Song , Hairston Marc R.
Published: February 2015

The prereversal enhancement (PRE) of the vertical plasma drift in the postsunset sector is an important factor that controls the generation of equatorial plasma bubbles. In this study, we use the measurements of the ion velocity meter on board the Communication/Navigation Outage Forecasting System satellite during 2008–2014 to identify the PRE and its effects on the occurrence of plasma bubbles. The seasonal and longitudinal distributions of the PRE are derived at different solar flux levels. Large PRE occurs at 240–360° longitudes in equinoctial months and December solstice, and small or downward PRE occurs around ±60° in June solstice. The seasonal and longitudinal distributions of large‐amplitude equatorial spread F (ESF) (ΔN > 5 × 1010 m−3) are similar to that of the PRE, while the occurrence probability of ESF including smaller‐amplitude perturbations (ΔN > 1 × 1010 m−3) can be quite high at any longitude in any season. A quantitative relationship between the PRE and the ESF occurrence probability is derived and well characterized by the cumulative distribution function of a continuous probability distribution. Such a distribution implies that the occurrence of ESF is a probability event. The ESF occurrence probability is small when the PRE is zero or downward and becomes larger than 80% when the PRE is greater than 40 m s−1. Both the ESF occurrence probability and the amplitude increase with the solar radio flux.
Numerical modeling of the Mount Meager landslide constrained by its force history derived from seismic data
Authors: Moretti L. , Allstadt K. , Mangeney A. , Capdeville Y. , Stutzmann E. , Bouchut F.
Published: February 2015

We focus on the 6 August 2010 Mount Meager landslide that occurred in Southwest British Columbia, Canada. This 48.5 Mm3 rockslide that rapidly changed into a debris flow was recorded by over 25 broadband seismic stations. We showed that the waveform inversion of the seismic signal making it possible to calculate the time history of the force applied by the landslide to the ground is very robust and stable, even when using only data from a single station. By comparing this force with the force calculated through numerical modeling of the landslide, we are able to support the interpretation of seismic data made using a simple block model. However, our study gives different values of the friction coefficients involved and more details about the volumes and orientation of the subevents and the flow trajectory and velocity. Our sensitivity analysis shows that the characteristics of the released mass and the friction coefficients all contribute to the amplitude and the phase of the force. Despite this complexity, our study makes it possible to discriminate the best values of all these parameters. Our results suggest that comparing simulated and inverted forces helps to identify appropriate rheological laws for natural flows. We also show that except for the initial collapse, peaks in the low‐frequency force related to bends and runup over topography changes are associated with high‐frequency generation, possibly due to an increased agitation of the granular material involved.
An experimental investigation of dyke injection under regional extensional stress
Authors: Daniels K. A. , Menand T.
Published: February 2015

Dyke injection is a fundamental process of magma transport in the crust, occurring in all tectonic settings. The effect of extensional stress regimes on dyke injections is particularly important to understanding a wide spectrum of processes including continental rifting and volcanic activity. Yet dyke injection in extensional regimes has been relatively understudied. In addition, the effect of dyke‐dyke interaction modifying the surrounding stress field and leading to dyke rotation about the vertical axis has not been addressed. We present the results from 23 laboratory analogue experiments investigating lateral dyke injections in a remote extensional stress field. This study is unique in that it addresses the effect of both extension and dyke‐dyke interaction on the lateral propagation and rotation of dykes. The experiments study the interrelationship between successive lateral dyke injections by examining dyke injection thickness, injection spacing, injection orientation, extension, and structural relationship. A relationship between the rotation angle between two successive intrusions and the distance separating them under given extensional stress conditions is established. The rotation angle depends on two dimensionless numbers: the ratio of fluid overpressure of the first injection and remote tensile stress, and the ratio of the spacing between injections and the height of the first intrusion. The experiments show how the stress field is perturbed by an intrusion and how the remote stress field is locally relieved by this intrusion. The results show furthermore that measuring or estimating the rotation angles between successive intrusions within rift zones allows the spatial distribution of these intrusions to be estimated. In the case of the actively spreading Red Sea rift in Afar, Ethiopia, we find that the vast majority of the dykes are predicted to intrude within 10 km of each other and most frequently between 4 and 5 km, in good agreement with independent geophysical observations.
On the eastward shift of winter surface chlorophyll‐a bloom peak in the Bay of Bengal
Authors: Martin M. V. , Shaji C.
Published: February 2015

Analysis of satellite‐derived surface layer phytoplankton chlorophyll‐a concentration (Chl‐a) in the Bay of Bengal revealed an eastward shift of peak of Chl‐a bloom during northeast monsoon period (November–March) from western to the eastern Bay. The winter Chl‐a bloom in the western Bay is shorter duration (∼1–2 months) while that in the eastern Bay is longer duration (∼3–4 months). Unlike other oceans, the eastward bloom peak shift found in the Bay of Bengal is opposite to the direction of propagation of Rossby wave and seasonal mean zonal currents. During winter, sufficient light is available in the Bay of Bengal for phytoplankton growth. Herein, we studied the processes controlling the eastward winter bloom peak shift and the zonal depiction of bloom duration in the Bay of Bengal. There is no single dominant process that drives the eastward bloom peak shift everywhere in the Bay of Bengal. Rather, different physical processes operate in different regions. The physical mechanisms governing the eastward winter Chl‐a bloom peak shift reported here include open ocean Ekman pumping, coastal upwelling, upwelling driven by Rossby wave, wind‐induced vertical mixing, nutrients supply from river input, and westward advection through prevailing zonal currents.
Short wind waves on the ocean: Wavenumber‐frequency spectra
Authors: Plant William J.
Published: February 2015

Dominant surface waves on the ocean exhibit a dispersion relation that confines their energy to a curve in a wavenumber‐frequency spectrum. Short wind waves on the ocean, on the other hand, are advected by these dominant waves so that they do not exhibit a well‐defined dispersion relation over many realizations of the surface. Here we show that the short‐wave analog to the dispersion relation is a distributed spectrum in the wavenumber‐frequency plane that collapses to the standard dispersion relation in the absence of long waves. We compute probability distributions of short‐wave wavenumber given a (frequency, direction) pair and of short‐wave frequency given a (wavenumber, direction) pair. These two probability distributions must yield a single spectrum of surface displacements as a function of wavenumber and frequency, F(k,f). We show that the folded, azimuthally averaged version of this spectrum has a “butterfly” pattern in the wavenumber‐frequency plane if significant long waves are present. Integration of this spectrum over frequency yields the well‐known k−3 wavenumber spectrum. When integrated over wavenumber, the spectrum yields an f−4 form that agrees with measurement. We also show that a cut through the unfolded F(k,f) at constant k produces the well‐known form of moderate‐incidence‐angle Doppler spectra for electromagnetic scattering from the sea. This development points out the dependence of the short‐wave spectrum on the amplitude of the long waves.
A Southern Hemisphere sea level pressure‐based precursor for ENSO warm and cold events
Authors: Hamlington B. D. , Milliff R. F. , van Loon H. , Kim K.‐Y.
Published: February 2015

Past studies have described large‐scale sea level pressure (SLP) variations in the Southern Hemisphere that lead to El Nino–Southern Oscillation (ENSO) warm and cold events (WE and CE). By relying on this description and the importance of the related variability in the lead up to WE and CE, Southern Hemisphere SLP variations in May‐June‐July (MJJ) are shown here to be excellent predictors for the peak warm/cold events in sea‐surface temperatures (SST) and sea level pressure that mark the mature phase of a warm/cold event in November‐January of the same year. Cyclostationary empirical orthogonal functions (CSEOFs) are used to extract the variability associated with this description of SLP evolution leading to extreme events, underscoring the importance of this signal in the build‐up to ENSO events. Using the CSEOF decomposition, an MJJ precursor is established and shown to precede impending warm and cold events in the past sixty years. Furthermore, the precursor developed in this study would have suggested that a significant WE for the latter half of 2014 was unlikely.
Cross‐tail expansion of dipolarizing flux bundles
Authors: Liu Jiang , Angelopoulos V. , Zhou Xu‐Zhi , Yao Zhong‐Hua , Runov A.
Published: February 2015

Dipolarizing flux bundles (DFBs), magnetotail flux tubes with stronger, more dipolar magnetic field than the background magnetotail plasma, which are led by dipolarization fronts, typically propagate earthward within bursty bulk flows. Although DFBs are localized (typically 1–3 RE) in the cross‐tail direction, many of them may combine to cause global effects, such as the substorm current wedge. Knowledge of how this local‐to‐global coupling happens is crucial for understanding magnetotail dynamics. We investigate how the coupling happens using multipoint observations from the Time History of Events and Macroscale Interactions during Substorms mission. Our results show that most DFBs expand in the cross‐tail direction as they propagate earthward. Through such expansion, azimuthally localized DFBs can cover a wide region to cause global effects when they arrive at the inner edge of the plasma sheet.
Multifunctional Silver‐Exchanged Zeolite Micromotors for Catalytic Detoxification of Chemical and Biological Threats
Authors: Singh Virendra V. , Jurado‐Sánchez Beatriz , Sattayasamitsathit Sirilak , Orozco Jahir , Li Jinxing , Galarnyk Michael , Fedorak Yuri , Wang Joseph
Published: February 2015

Multifunctional reactive‐zeolite‐based micromotors have been developed and characterized toward effective and rapid elimination of chemical and biological threats. The incorporation of silver ions (Ag+) into aluminosilicate zeolite framework imparts several attractive functions, including strong binding to chemical warfare agents (CWA) followed by effective degradation, and enhanced antibacterial activity. The new zeolite‐micromotors protocol thus combines the remarkable adsorption capacity of zeolites and the efficient catalytic properties of the reactive Ag+ ions with the autonomous movement of the zeolite micromotors for an accelerated detoxification of CWA. Furthermore, the high antibacterial activity of Ag+ along with the rapid micromotor movement enhances the contact between bacteria and reactive Ag+, leading to a powerful “on‐the‐fly” bacteria killing capacity. These attractive adsorptive/catalytic features of the self‐propelled zeolite micromotors eliminate secondary environmental contamination compared to adsorptive micromotors. The distinct cubic geometry of the zeolite micromotors leads to enhanced bubble generation and faster movement, in unique movement trajectories, which increases the fluid convection and highly efficient detoxification of CWA and killing of bacteria. The attractive capabilities of these zeolite micromotors will pave the way for their diverse applications in defense, environmental and biomedical applications in more economical and sustainable manner.
Polymeric Photocatalysts Based on Graphitic Carbon Nitride
Authors: Cao Shaowen , Low Jingxiang , Yu Jiaguo , Jaroniec Mietek
Published: February 2015

Semiconductor‐based photocatalysis is considered to be an attractive way for solving the worldwide energy shortage and environmental pollution issues. Since the pioneering work in 2009 on graphitic carbon nitride (g‐C3N4) for visible‐light photocatalytic water splitting, g‐C3N4‐based photocatalysis has become a very hot research topic. This review summarizes the recent progress regarding the design and preparation of g‐C3N4‐based photocatalysts, including the fabrication and nanostructure design of pristine g‐C3N4, bandgap engineering through atomic‐level doping and molecular‐level modification, and the preparation of g‐C3N4‐based semiconductor composites. Also, the photo­catalytic applications of g‐C3N4‐based photocatalysts in the fields of water splitting, CO2 reduction, pollutant degradation, organic syntheses, and bacterial disinfection are reviewed, with emphasis on photocatalysis promoted by carbon materials, non‐noble‐metal cocatalysts, and Z‐scheme heterojunctions. Finally, the concluding remarks are presented and some perspectives regarding the future development of g‐C3N4‐based photocatalysts are highlighted.
Clumping Criteria of Vertical Nanofibers on Surfaces
Authors: Zhou Ming , Tian Yu , Zeng Hongbo , Pesika Noshir , Israelachvili Jacob
Published: February 2015

The side–side, side–tip, and tip–tip clumping of nanofibers, including nanowires and nanotubes on surfaces, is a common problem that can diminish their optical, electrical, and mechanical performance. However, these different clumping configurations brought much complexity and confused researchers to predict or design the desired clumping or nonclumping. In this study, a universal model in the unified formula for the critical clumping criteria for three contact geometries of nanofiber arrays is derived in terms of two‐dimensionless geometric and mechanical parameters, based on the length, radius, spacing, Young's modulus, and adhesion energy of the nanofibers. The model provides an easy way to predict the sequences of the three clumping configurations, which are successfully verified by analyzing various clumping structures reported in the literatures. This study provides new insights into, and methods for, designing nanofiber arrays on surfaces to achieve desired clumping or nonclumping structures.
Ruthenium‐Catalyzed Hydroamination of Aminoallenes: an Approach to Vinyl Substituted Heterocycles
Authors: Broggini Gianluigi , Poli Giovanni , Beccalli Egle M. , Brusa Filippo , Gazzola Silvia , Oble Julie
Published: February 2015

Heterosubstituted aminoallenes underwent smooth ruthenium‐catalyzed intramolecular exo‐hydroamination reactions yielding the corresponding five‐, six‐, or seven‐membered 1,3‐diaza‐ or 1,3‐oxaza‐heterocyclic structures. This procedure is a valuable and less expensive alternative to the already known transition metal‐catalyzed hydroamination reactions of aminoallenes.

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Highly Regio‐ and Diastereoselective Addition of Organolithium Reagents to Chiral Fluoroalkyl α,β‐Unsaturated N‐tert‐Butanesulfinyl Ketimines: A General and Efficient Access to α‐Tertiary Fluoroalkyl Allylic Amines and α‐Fluoroalkyl α‐Amino Acids
Authors: Liu Peng , Liu Zhen‐Jiang , Wu Fanhong
Published: February 2015

Highly regio‐ and diastereoselective 1,2‐addition of organolithium reagents to chiral fluoroalkyl α,β‐unsaturated N‐tert‐butanesulfinyl ketimines was developed, providing a general and efficient method for the asymmetric synthesis of structurally diverse α‐tertiary fluoroalkyl allylic amines in high yields and with excellent diastereoselectivities (dr up to>99:1). The synthetic application of the method was demonstrated by the rapid and convenient preparation of challenging α‐fluoroalkyl α‐amino acids with α‐tetrasubstituted carbon.

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Design and Synthesis of Chiral Binaphthol‐Derived Bisphosphoric Acids and Their Application in the Catalytic Enantioselective Hydrogenation of Quinolines
Authors: Wang Pei , Jia Yan‐E , Zhao Jia‐Zhen , Zhao Dan , Yuan Rui , Da Chao‐Shan
Published: February 2015

A series of binaphthol‐based bisphosphoric acids were successfully developed with inclusion of rigid cyclic phosphamide and phosphonate motifs. These chiral bisphosphoric acids were used as chiral organocatalysts in the hydrogen transformation of a series of quinolines to investigate their enantioselective catalytic activity.
Dekonstruktion kovalenter Organokatalyse
Authors: Holland Mareike C. , Gilmour Ryan
Published: February 2015

Die moderne Organokatalyse hat sich zu einem essenziellen Bestandteil der gegenwärtigen organischen Synthese entwickelt. Einer der markantesten Aspekte organokatalytischer Prozesse ist die biomimetische Weise, in welcher der Katalysator das Substrat bindet, wobei oftmals kovalent gebundene Intermediate in einer Art gebildet werden, die an enzymatische Katalyse erinnert. In der Tat geht der Prozess der Intermolekularisierung oft mit Konformationsänderungen des Katalysatorgerüsts einher, was die Analogie zu biologischen Systemen weiter verstärkt. Die Isolierung und Untersuchung dieser Katalyse‐Intermediate vereinfachen die rasche Erstellung von Konformations‐ und Reaktivitätsprofilen, welche die Entwicklung organokatalytischer Reaktionen erleichtern und/oder Reaktionsresultate erklären können. Die Dekonstruktion von kovalent gebundenen Organokatalyse‐Intermediaten als Designstrategie gewinnt an Bedeutung, motiviert durch die Fortschritte aus der Untersuchung von Reaktionsintermediaten in der mechanistischen metallorganischen und Enzymkatalyse.
Aus Biomasse hergestellte Kohlenstoff‐Quantenpunkt‐Sensibilisatoren für nanostrukturierte Festkörper‐Solarzellen
Authors: Briscoe Joe , Marinovic Adam , Sevilla Marta , Dunn Steve , Titirici Magdalena
Published: February 2015

Neue Hybridmaterialien aus ZnO‐Nanostäbchen, die mit drei verschiedenen, aus Biomasse hergestellten Kohlenstoff‐Quantenpunkten (CQDs) sensibilisiert wurden, wurden synthetisiert, charakterisiert und zum ersten Mal zur Produktion von nanostrukturierten Festkörper‐Solarzellen verwendet. Die funktionellen Gruppen der CQDs beeinflussen die Leistung der Solarzellen, und der beste Wirkungsgrad konnte durch alternierende Beschichtung mit zwei verschiedenen CQD‐Varianten erzielt werden.
Plumbonacrite Identified by X‐ray Powder Diffraction Tomography as a Missing Link during Degradation of Red Lead in a Van Gogh Painting
Authors: Vanmeert Frederik , Van der Snickt Geert , Janssens Koen
Published: February 2015

Red lead, a semiconductor pigment used by artists since antiquity, is known to undergo several discoloration phenomena. These transformations are either described as darkening of the pigment caused by the formation of either plattnerite (β‐PbO2) or galena (PbS) or as whitening by which red lead is converted into anglesite (PbSO4) or (hydro)cerussite (2 PbCO3⋅Pb(OH)2; PbCO3). X‐ray powder diffraction tomography, a powerful analytical method that allows visualization of the internal distribution of different crystalline compounds in complex samples, was used to investigate a microscopic paint sample from a Van Gogh painting. A very rare lead mineral, plumbonacrite (3 PbCO3⋅ Pb(OH)2⋅PbO), was revealed to be present. This is the first reported occurrence of this compound in a painting dating from before the mid 20th century. It constitutes the missing link between on the one hand the photoinduced reduction of red lead and on the other hand (hydro)cerussite, and thus sheds new light on the whitening of red lead.
Cobalt(III)‐katalysierte dirigierte C‐H‐Kupplung mit Diazoverbindungen: einfacher Zugang zu ausgedehnten π‐Systemen
Authors: Zhao Dongbing , Kim Ju Hyun , Stegemann Linda , Strassert Cristian A. , Glorius Frank
Published: February 2015

Die erste hocheffiziente und skalierbare Cobalt‐katalysierte dirigierte C‐H‐Funktionalisierung mit Carbenvorstufen wird vorgestellt. Diese Methode ermöglicht einen modularen Zugang zu einer neuen Klasse konjugierter polycyclischer Kohlenwasserstoffe mit einstellbarer Emissionswellenlänge in Lösung und im Festkörper.
Tetracyanido(difluorido)phosphate M+[PF2(CN)4]−
Authors: Bresien Jonas , Ellinger Stefan , Harloff Jörg , Schulz Axel , Sievert Katharina , Stoffers Alrik , Täschler Christoph , Villinger Alexander , Zur Täschler Cornelia
Published: February 2015

Die Untersuchung der Reaktion von M[PF6]‐Salzen mit Me3SiCN führte zu einem einfachen Syntheseprotokoll für die Isolierung einer Reihe von Salzen des zuvor unbekannten [PF2(CN)4]−‐Anions. Reaktionstemperatur und ‐druck sowie stöchiometrisches Verhältnis wurden optimiert, und die Kristallstrukturen von M[PF2(CN)4] (M= [nBu4N]+, Ag+, K+, Li+, H5O2+) wurden bestimmt. Die Einkristallröntgenstrukturanalyse zeigte, in Übereinstimmung mit den 31P‐ und 19F‐NMR‐Daten, ausschließlich die Bildung des cis‐Isomers. Ausgehend vom K[PF2(CN)4] konnte EMIm[PF2(CN)4], eine ionische Flüssigkeit mit sehr niedriger Viskosität, hergestellt werden.
Catalytic Upgrading of Biomass‐Derived Methyl Ketones to Liquid Transportation Fuel Precursors by an Organocatalytic Approach
Authors: Sankaranarayanapillai Shylesh , Sreekumar Sanil , Gomes Joseph , Grippo Adam , Arab George E. , Head‐Gordon Martin , Toste F. Dean , Bell Alexis T.
Published: February 2015

A highly efficient water‐tolerant, solid‐base catalyst for the self‐condensation of biomass‐derived methyl ketones to jet‐diesel fuel precursors was developed by grafting site‐isolated secondary amines on silica‐alumina supports. It is shown that apart from the nature and density of amine groups and the spatial separation of the acidic and basic sites, the acidity of the support material plays a critical role in defining the catalytic activity. It is also found that a combination of weakly acidic silanol/aluminol with secondary amine groups can mimic proline catalysts and are more effective in catalyzing the selective dimerization reaction than the combination of amines with organic acids. In situ FTIR measurements demonstrate that acidic groups activate methyl ketones through their carbonyl groups leading to a favorable CC bond formation step involving an enamine intermediate. DFT analysis of the reaction pathway confirms that CC bond formation is the rate‐limiting step.
Development of Imidazoline‐2‐Thiones Based Two‐Photon Fluorescence Probes for Imaging Hypochlorite Generation in a Co‐Culture System
Authors: Xu Qingling , Heo Cheol Ho , Kim Gyoungmi , Lee Hyo Won , Kim Hwan Myung , Yoon Juyoung
Published: February 2015

We designed and prepared the imidazoline‐2‐thione containing OCl− probes, PIS and NIS, which operate through specific reactions with OCl− that yield corresponding fluorescent imidazolium ions. Importantly, we demonstrated that PIS can be employed to image OCl− generation in macrophages in a co‐culture system. We have also employed two‐photon microscopy and PIS to image OCl− in live cells and tissues, indicating that this probe could have wide biological applications.
Cooperative Catalysis of Noncompatible Catalysts through Compartmentalization: Wacker Oxidation and Enzymatic Reduction in a One‐Pot Process in Aqueous Media
Authors: Sato Hirofumi , Hummel Werner , Gröger Harald
Published: February 2015

A Wacker oxidation using CuCl/PdCl2 as a catalyst system was successfully combined with an enzymatic ketone reduction to convert styrene enantioselectively into 1‐phenylethanol in a one‐pot process, although the two reactions conducted in aqueous media are not compatible due to enzyme deactivation by Cu ions. The one‐pot feasibility was achieved via compartmentalization of the reactions. Conducting the Wacker oxidation in the interior of a polydimethylsiloxane thimble enables diffusion of only the organic substrate and product into the exterior where the biotransformation takes place. Thus, the Cu ions detrimental to the enzyme are withheld from the reaction media of the biotransformation. In this one‐pot process, which formally corresponds to an asymmetric hydration of alkenes, a range of 1‐arylethanols were formed with high conversions and 98–99 % ee. In addition, the catalyst system of the Wacker oxidation was recycled 15 times without significant decrease in conversion.
Sulfates‐Based Nanothermites: An Expanding Horizon for Metastable Interstitial Composites
Authors: Comet Marc , Vidick Geoffrey , Schnell Fabien , Suma Yves , Baps Bernard , Spitzer Denis
Published: February 2015

Metal sulfates (Ba, Bi, Ca, Cu, Mg, Mn, Na, Zn, Zr) were used as oxidizers in reactive compositions with Al nanopowder. These new kinds of nanothermites have outstandingly high reaction heats (4–6 kJ g−1) compared to conventional Al/metal oxides (1.5–4.8 kJ g−1) and also have good combustion velocities (200–840 m s−1 vs 100–2500 m s−1). These compositions are extremely insensitive to friction making their preparation and handling easy and safe. The sulfate hydration water increases the reaction heats and has a significant effect on the sensitivity to impact and to electrostatic discharge. The reaction of Al with water is easier to initiate than the one with sulfate which leads to two possible decomposition modes for samples exposed to an open flame. The pyrotechnical properties observed with sulfates have also been found for other sulfur oxygenates (SO32−, S2O32−, S2O82−) which opens up new horizons in the domain of metastable interstitial composites.
Tetracyanido(difluorido)phosphates M+[PF2(CN)4]−
Authors: Bresien Jonas , Ellinger Stefan , Harloff Jörg , Schulz Axel , Sievert Katharina , Stoffers Alrik , Täschler Christoph , Villinger Alexander , Zur Täschler Cornelia
Published: February 2015

The systematic study of the reaction of M[PF6] salts and Me3SiCN led to a synthetic method for the synthesis and isolation of a series of salts containing the unprecedented [PF2(CN)4]− ion in good yields. The reaction temperature, pressure, and stoichiometry were optimized. The crystal structures of M[PF2(CN)4] (M=[nBu4N]+, Ag+, K+, Li+, H5O2+) were determined. X‐ray crystallography showed the exclusive formation of the cis isomer in accord with 31P and 19F solution NMR spectroscopy data. Starting with the K[PF2(CN)4] the room temperature ionic liquid EMIm[PF2(CN)4] was prepared exhibiting a rather low viscosity.
Enhancing management effectiveness of invasive lionfish using distance sampling and detection probability
Authors: Tilley Alexander , Carter Elliott , Wassermann Sophia , López‐Angarita juliana
Published: February 2015

Invasive lionfishPterois volitansandPterois milesare one of the greatest threats to coral reef fisheries in the Caribbean. Management currently relies solely on removal, however, there is little understanding of spatial ecology of lionfish to inform management strategies and thus, increase their effectiveness.

The use of detection probability and population density estimates from distance sampling as a method to: (a) estimate spatial and depth variations in detectability of lionfish to prioritize removal efforts; (b) reduce costs related to removal in the Caribbean; and (c) provide quantifiable baseline data against which management success can be measured was evaluated.

Underwater visual transect surveys were conducted at varying depths at four coral reef sites in the Turks and Caicos Islands using perpendicular distance sampling. Detection functions were fitted to distance data from 299 lionfish sightings across 37 transects to explore variation in detectability among survey sites and depths.

Lionfish were detected with a 15.9% (12.2–20.6%) (mean ± 95% CI) probability across all sampling. Detection probability was significantly higher in depths < 15 m, however, lionfish density and mean size increased with depth. Population density on South Caicos reefs was estimated at 1679 (1140.4–2473.1) individuals per km2. Increased detection probability in shallower depths implies caution is needed in assessing management success at depth, and that removal methods and effort should be related specifically to depth and habitat factors.

Distance sampling is an effective method for accurate estimation of lionfish population density and detection probability, providing metrics by which to identify priority management areas, and track population changes along with the success of removal efforts. As a result its integration into initial planning and continued monitoring aspects of lionfish management throughout the Caribbean is recommended.

Copyright © 2015 John Wiley & Sons, Ltd.
What is the true nitrogenase reaction? A guided approach
Authors: Ipata Piero L. , Pesi Rossana
Published: February 2015

Only diazotrophic bacteria, called Rizhobia, living as symbionts in the root nodules of leguminous plants and certain free‐living prokaryotic cells can fix atmospheric N2. In these microorganisms, nitrogen fixation is carried out by the nitrogenase protein complex. However, the reduction of nitrogen to ammonia has an extremely high activation energy due to the stable (unreactive) NN triple bond. The structural and functional features of the nitrogenase protein complex, based on the stepwise transfer of eight electrons from reduced ferredoxin to the nitrogenase, coupled to the hydrolysis of 16 ATP molecules, to fix one N2 molecule into two NH3 molecules, is well understood. Yet, a number of different nitrogenase‐catalyzed reactions are present in biochemistry textbooks, which might cause misinterpretation. In this article, we show that when trying to balance the reaction catalyzed by the nitrogenase protein complex, it is important to show explicitly the 16 H+ released by the hydrolysis of the 16 ATP molecules needed to fix the atmospheric N2 © 2015 by the International Union of Biochemistry and Molecular Biology, 43(3):142–144, 2015.
Biodiesel: Sustainable Energy Replacement to Petroleum‐Based Diesel Fuel – A Review
Authors: Ajala Olawale E. , Aberuagba Folorunsho , Odetoye Temitope E. , Ajala Adejoke M.
Published: February 2015

Biodiesel is a sustainable and renewable source of fuel. It has been considered as a comparable substitute to petro‐diesel, which is a fast depleting resource. Many studies have been undertaken on biodiesel production from various feedstock as a result of its importance. The differences between the physico‐chemical properties of biodiesel and petro‐diesel were considered with the aim of justifying the applicability of biodiesel in compression ignition engines (CIE). It was established that biodiesel has relatively close BTE (brake thermal efficiency) and BSFC (brake specific fuel consumption) values with petro‐diesel, hence, is suitable for CIE operation without any modification. The exhaust from CIE using biodiesel was lower compared to petro‐diesel and this confirms the environmental friendliness of biodiesel. The catalyst being an important substance in the transesterification reaction of vegetable oil/animal fat to produce biodiesel was comprehensively discussed, and heterogeneous catalysts were established to be preferred due to several advantages over homogenous catalysts. This paper reviews biodiesel production, prospects, benefits and challenges as a replacement for petrol diesel.
Rational Design of a β‐Glycosidase with High Regiospecificity for Triterpenoid Tailoring
Authors: Park Sang Jin , Choi Jung Min , Kyeong Hyun‐Ho , Kim Song‐Gun , Kim Hak‐Sung
Published: February 2015

Triterpenoids with desired glycosylation patterns have attracted considerable attention as potential therapeutics for inflammatory diseases and various types of cancer. Sugar‐hydrolyzing enzymes with high substrate specificity would be far more efficient than other methods for the synthesis of such specialty triterpenoids, but they are yet to be developed. Here we present a strategy to rationally design a β‐glycosidase with high regiospecificity for triterpenoids. A β‐glycosidase with broad substrate specificity was isolated, and its crystal structure was determined at 2.0 Å resolution. Based on the product profiles and substrate docking simulations, we modeled the substrate binding modes of the enzyme. From the model, the substrate binding cleft of the enzyme was redesigned in a manner that preferentially hydrolyzes glycans at specific glycosylation sites of triterpenoids. The designed mutants were shown to produce a variety of specialty triterpenoids with high purity.
Generations: The old gives way to the new, and the new is too soon the old
Authors: Butman Samuel
Published: February 2015

Key Points

This report highlights the importance of unique lesion characteristics (ostial RCA) with regard to outcomes

In practice, choosing the correct stent for the right lesion and patient does make a difference

New stent delivery systems, for specific subsets of lesions will continually need to be compared to optimize long‐term outcomes
Evolving TAVR, and the need for intelligent design
Authors: Block Peter C.
Published: February 2015

Key Points

It is possible to identify a subgroup of TF/TAVR patients who can be extubated early and have brief intensive unit stays with early discharge.

This strategy results in reduced hospital stays and reduced direct costs, though costs may still exceed reimbursement.

Outcomes are not compromised.
Metal–Organic Frameworks: New Interlayer Dielectric Materials
Authors: Usman Muhammad , Mendiratta Shruti , Lu Kuang‐Lieh
Published: February 2015

Some metal–organic frameworks (MOFs) with low dielectric constants, high thermal/mechanical stabilities, low leakage currents, and good comparability in devices can lead to integrated circuits, in which the MOF can act as an interlayer dielectric (ILD) material with tunable structural properties and high porosity. Based on initial research, in this Highlight, we propose a roadmap that can serve as a starting point for addressing the potential use of MOFs as ILD materials in the microelectronics industry, providing an effective path towards achieving remarkable new applications of dielectric MOFs in the future.
Sterically Hindered Luminescent PtII–Phosphite Complexes for Electroluminescent Devices
Authors: Mydlak Mathias , Yang Cheng‐Han , Polo Federico , Galstyan Anzhela , Daniliuc Constantin G. , Felicetti Michael , Leonhardt Jens , Strassert Cristian A. , De Cola Luisa
Published: February 2015

PtII complexes with one bulky, sterically demanding, tertiary phosphite ancillary ligand and a coordinating chromophore are herein presented. The phosphite ligand, tris(2,4‐di‐tert‐butylphenyl) acts as a bidentate ligand coordinating the platinum ion through the central phosphorus atom and a cyclometalating carbon atom of one of the substituents. The two free phenoxy moieties lie above and below the coordination plane, leading to steric hindrance that avoids aggregation and provides solubility in organic solvents. The other two coordination sites on the central metal ion are occupied by a chromophoric ligand, which is responsible for the energy of the luminescent excited state. This separation of functions, on the two coordinated ligands, allows the use of a wider range of luminophores with good luminescent properties, maintaining the control of the intermolecular interactions with the non‐chromophoric ligand. Based on this approach we were able to achieve a bright deep blue emission (λ=444 nm, Φem=0.38) from a complex with a tailored ligand, which was then used for the fabrication of an electroluminescent device. In addition commercially available luminophores were also employed to synthesize green emitters.
On the Radical Nature of Iron‐Catalyzed Cross‐Coupling Reactions
Authors: Hedström Anna , Izakian Zakieh , Vreto Irma , Wallentin Carl‐Johan , Norrby Per‐Ola
Published: February 2015

The radical nature of iron‐catalyzed cross‐coupling between Grignard reagents and alkyl halides has been studied by using a combination of competitive kinetic experiments and DFT calculations. In contrast to the corresponding coupling with aryl halides, which commences through a classical two‐electron oxidative addition/reductive elimination sequence, the presented data suggest that alkyl halides react through an atom‐transfer‐initiated radical pathway. Furthermore, a general iodine‐based quenching methodology was developed to enable the determination of highly accurate concentrations of Grignard reagents, a capability that facilitates and increases the information output of kinetic investigations based on these substrates.
Access to New Endoperoxide Derivatives by Electrochemical Oxidation of Substituted 3‐Azabicyclo[4.1.0]hept‐4‐enes
Authors: Nuter Frédérick , Dimé Abdou Khadre Djily , Chen Cheng , Bounaadja Lotfi , Mouray Elisabeth , Florent Isabelle , Six Yvan , Buriez Olivier , Marinetti Angela , Voituriez Arnaud
Published: February 2015

A series of substituted 3‐azabicyclo[4.1.0]hept‐4‐ene derivatives were prepared and analysed by cyclic voltammetry. Preparative aerobic electrochemical oxidation reactions were then carried out. Three original endoperoxides were isolated, characterised and subjected to antimalarial and cytotoxicity activity assays.
High Excimer‐State Emission of Perylene Bisimides and Recognition of Latent Fingerprints
Authors: Wang Ke‐Rang , Yang Zi‐Bo , Li Xiao‐Liu
Published: February 2015

High excimer‐state emission in the H‐type aggregate of a novel asymmetric perylene bisimide derivative, 6, with triethyleneglycol chains and lactose functionalization was achieved in water. Furthermore, its application for enhancing the visualization of transfer latent fingerprints from glass slides to the poly(vinylidene fluoride) (PVDF) membrane was explored, which showed clear images of the latent fingerprint in daylight and under 365 nm ultraviolet illumination.
The Correlation of Electrochemical Measurements and Molecular Junction Conductance Simulations in β‐Strand Peptides
Authors: Horsley John R. , Yu Jingxian , Abell Andrew D.
Published: February 2015

Understanding the electronic properties of single peptides is not only of fundamental importance, but it is also paramount to the realization of peptide‐based molecular electronic components. Electrochemical and theoretical studies are reported on two β‐strand‐based peptides, one with its backbone constrained with a triazole‐containing tether introduced by Huisgen cycloaddition (peptide 1) and the other a direct linear analogue (peptide 2). Density functional theory (DFT) and non‐equilibrium Green’s function were used to investigate conductance in molecular junctions containing peptides 3 and 4 (analogues of 1 and 2). Although the peptides share a common β‐strand conformation, they display vastly different electronic transport properties due to the presence (or absence) of the side‐bridge constraint and the associated effect on backbone rigidity. These studies reveal that the electron transfer rate constants of 1 and 2, and the conductance calculated for 3 and 4, differ by approximately one order of magnitude, thus providing two distinctly different conductance states and what is essentially a molecular switch. A definitive correlation of electrochemical measurements and molecular junction conductance simulations is demonstrated using two different charge transfer techniques. This study furthers our understanding of the electronic properties of peptides at the molecular level, which provides an opportunity to fine‐tune their molecular orbital energies through suitable structural manipulation.