bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impact of Tax Governance on the Governmental Corruption level in Jordan
Authors: Baker Abed Al-Rahman Mohammad , Al-Ibainy Mohannad Mohammad
Published: March 2018

The current study aimed at identifying the impact of applying two tax governance mechanisms (i.e. direct and indirect tax control) on the financial and administrative governmental corruption levels at the income and sales tax department in Jordan in 2017. The researchers developed a questionnaire to collect data. Then, they distributed the questionnaire forms to the random sample they selected. The study’s sample consists of 22 tax auditors, 8 tax supervisors, and 2 heads of the auditing departments who work at several directorates affiliated with the income and sales tax department at Jordan. The sample also includes 61 external certified auditors who were accredited by the latter department (n=93). The collected data was analyzed through the SPSS program and percentages and frequencies were calculatedIt was concluded that the application of the two tax governance mechanisms (i.e. direct and indirect tax control) can significantly reduce the levels of financial and administrative governmental corruption at the income and sales tax department. It was also concluded that external auditors - who are part of the tax governance system - play a significant role in reducing such corruption levels through enforcing indirect tax control on the income and sales tax department.Finally, the researchers recommend holding training programs to improve the efficiency of the employees working at the control departments of taxation authorities. They also recommend using advanced accounting and tax systems to raise the efficiency of the employees working at of the control department at taxation authorities.
The Impact of Motivations on Employees Performance: Case Study from Palestinian Commercial Banks
Authors: Abusharbeh Mohammed T. , Nazzal Hanan Hasan
Published: March 2018

Motivation aims to empower and liberalize people as enhance their entrepreneurial abilities to recognize the interactions between humans and their abilities to work. Thus, this paper is aimed to examine the impact of motivations on employee’s performance in Palestinian banking industry. The survey data was collected through distributing a questionnaire on employees that working in Palestinian commercial banks. Relied on Pearson correlation and multiple regression analysis, this paper reveals that moral motives are significantly and positively predicted employees performance. Moreover, the scholars find a high level of motivations provided to employees that working in Palestinian commercial banks. However, the material and social incentives are not predicted employees performance. On other side, the paper found that there are differences between the levels of motivation when it comes to the demographic data like qualifications, years of experiences, and job title. Finally, the study recommended that Palestinian banks needs to adapt and develop their motivation system in order to satisfy all employees’ moral needs.
Evaluation of Two Lactic Acid Bacteria Starter Cultures for the Fermentation of Natural Black Table Olives (Olea europaea L cv Kalamon)
Authors: Papadelli Marina , Zoumpopoulou Georgia , Georgalaki Marina , Anastasiou Rania , Manolopoulou Eugenia , Lytra Ioanna , Papadimitriou Kostas , Tsakalidou Effie
Published: March 2018

The production of Greek-style natural black table olives remains an empirical process relying on spontaneous fermentation despite its economic significance. For this reason producers often resort to increased NaCl concentration of the brine to secure quality of the product. In this study we employ two lactic acid bacteria Leuconostoc mesenteroides subsp. mesenteroides Lm139 and Lactobacillus pentosus DSM 16366 as starters in separate laboratory low salinity fermentations of “Kalamon” cultivar olives, processed according to the Greek-style method. L. mesenteroides subsp. mesenteroides Lm139 was previously isolated from Kalamon olives laboratory spontaneous fermentations, while L. pentosus DSM 16366 was isolated from fermenting green olives prepared according to the Spanish-style method. Spontaneous olives fermentation was also performed as a control. Microbiological and physicochemical analyses of the brines revealed that the use of the starters had a significant effect on the olives fermentation, leading to a faster acidification due to the more efficient consumption of soluble sugars in the brines. The final pH value reached by each starter culture used indicates a successful lactic fermentation. The production of lactic acid by the starters and the concomitant drop of the pH value proved to inhibit enterobacteria in a shorter period of time compared to the spontaneous fermentation. Concluding, the use of either of the two lactic acid bacteria as starters in Greek-style Kalamon olives fermentation could lead to a more controllable fermentation at lower salinities. The resulting product could be of higher quality with extended shelf-life while being at the same time safer for the consumer.
Chaperone DnaJ Influences the Formation of Biofilm by Escherichia coli
Authors: Grudniak Anna , Włodkowska Jolanta , Wolska Krystyna
Published: March 2018

DnaJ chaperone, a member of the so called DnaK-DnaJ-GrpE chaperone machine plays an important role in cell physiology. The ability of Escherichia coli ΔdnaJ mutant to form biofilm was studied. It was shown that this mutant is impaired in biofilm development when exposed to 42°C for 2 h. The impairment in biofilm development was observed when the heat shock was applied either at the onset of biofilm formation or 2 h later. The biofilm formed was thinner and its structure was changed as compared to wild-type strain. This defect could be complemented by the introduction of a wild-type gene on a low-copy plasmid.
Nociceptive interneurons control modular motor pathways to promote escape behavior in Drosophila
Authors: Burgos Anita , Honjo Ken , Ohyama Tomoko , Qian Cheng Sam , Shin Grace Ji-eun , Gohl Daryl M , Silies Marion , Tracey W Daniel , Zlatic Marta , Cardona Albert , Grueber Wesley B
Published: March 2018

Rapid and efficient escape behaviors in response to noxious sensory stimuli are essential for protection and survival. Yet, how noxious stimuli are transformed to coordinated escape behaviors remains poorly understood. In Drosophila larvae, noxious stimuli trigger sequential body bending and corkscrew-like rolling behavior. We identified a population of interneurons in the nerve cord of Drosophila, termed Down-and-Back (DnB) neurons, that are activated by noxious heat, promote nociceptive behavior, and are required for robust escape responses to noxious stimuli. Electron microscopic circuit reconstruction shows that DnBs are targets of nociceptive and mechanosensory neurons, are directly presynaptic to pre-motor circuits, and link indirectly to Goro rolling command-like neurons. DnB activation promotes activity in Goro neurons, and coincident inactivation of Goro neurons prevents the rolling sequence but leaves intact body bending motor responses. Thus, activity from nociceptors to DnB interneurons coordinates modular elements of nociceptive escape behavior.
ICE1 promotes the link between splicing and nonsense-mediated mRNA decay
Authors: Baird Thomas D , Cheng Ken Chih-Chien , Chen Yu-Chi , Buehler Eugen , Martin Scott E , Inglese James , Hogg J Robert
Published: March 2018

The nonsense-mediated mRNA decay (NMD) pathway detects aberrant transcripts containing premature termination codons (PTCs) and regulates expression of 5–10% of non-aberrant human mRNAs. To date, most proteins involved in NMD have been identified by genetic screens in model organisms; however, the increased complexity of gene expression regulation in human cells suggests that additional proteins may participate in the human NMD pathway. To identify proteins required for NMD, we performed a genome-wide RNAi screen against >21,000 genes. Canonical members of the NMD pathway were highly enriched as top hits in the siRNA screen, along with numerous candidate NMD factors, including the conserved ICE1/KIAA0947 protein. RNAseq studies reveal that depletion of ICE1 globally enhances accumulation and stability of NMD-target mRNAs. Further, our data suggest that ICE1 uses a putative MIF4G domain to interact with exon junction complex (EJC) proteins and promotes the association of the NMD protein UPF3B with the EJC.
Out of Asia: mitochondrial evolutionary history of the globally introduced supralittoral isopodLigia exotica
Authors: Hurtado Luis A. , Mateos Mariana , Wang Chang , Santamaria Carlos A. , Jung Jongwoo , Khalaji-Pirbalouty Valiallah , Kim Won
Published: March 2018

The native ranges and invasion histories of many marine species remain elusive due to a dynamic dispersal process via marine vessels. Molecular markers can aid in identification of native ranges and elucidation of the introduction and establishment process. The supralittoral isopodLigia exoticahas a wide tropical and subtropical distribution, frequently found in harbors and ports around the globe. This isopod is hypothesized to have an Old World origin, from where it was unintentionally introduced to other regions via wooden ships and solid ballast. Its native range, however, remains uncertain. Recent molecular studies uncovered the presence of two highly divergent lineages ofL. exoticain East Asia, and suggest this region is a source of nonindigenous populations. In this study, we conducted phylogenetic analyses (Maximum Likelihood and Bayesian) of a fragment of the mitochondrial 16S ribosomal (r)DNA gene using a dataset of this isopod that greatly expanded previous representation from Asia and putative nonindigenous populations around the world. For a subset of samples, sequences of 12S rDNA and NaK were also obtained and analyzed together with 16S rDNA. Our results show thatL. exoticais comprised of several highly divergent genetic lineages, which probably represent different species. Most of the 16S rDNA genetic diversity (48 haplotypes) was detected in East and Southeast Asia. Only seven haplotypes were observed outside this region (in the Americas, Hawai’i, Africa and India), which were identical or closely related to haplotypes found in East and Southeast Asia. Phylogenetic patterns indicate theL. exoticaclade originated and diversified in East and Southeast Asia, and only members of one of the divergent lineages have spread out of this region, recently, suggesting the potential to become invasive is phylogenetically constrained.
Chloropid flies (Diptera, Chloropidae) associated with pitcher plants in North America
Authors: Mlynarek Julia J. , Wheeler Terry A.
Published: March 2018

We review the taxonomy and ecology of Chloropidae (Diptera) associated with pitcher plants (Sarraceniaceae) in North America.Tricimba wheeleriMlynarek sp.n. is described from the pitchers ofSarracenia alataAlph.Wood andS. leucophyllaRaf. in the southeastern United States (Alabama, Mississippi).Aphanotrigonum darlingtoniae(Jones) associated withDarlingtonia californicaTorr. in northern California is redescribed, including the first description of male genitalic characters. A lectotype is designated forA. darlingtoniae. Published records of other species ofTricimbaLioy in pitcher plants in North America are considered accidental or facultative occurrences; published records ofAphanotrigonumDuda as pitcher plant associates in eastern North America are probably errors in identification.
Millennial‐Scale Instability in the Geomagnetic Field Prior to the Matuyama‐Brunhes Reversal
Authors: Balbas Andrea Marie , Koppers Anthony A. P. , Clark Peter U. , Coe Robert S. , Reilly Brendan T. , Stoner Joseph S. , Konrad Kevin
Published: March 2018

Changes in the Earth's magnetic field have global significance that reach from the outer core extending out to the uppermost atmosphere. Paleomagnetic records derived from sedimentary and volcanic sequences provide important insights into the geodynamo processes that govern the largest geomagnetic changes (polarity reversals), but dating uncertainties have hindered progress in this understanding. Here, we report a paleomagnetic record from multiple lava flows on Tahiti that bracket the Matuyama‐Brunhes (M‐B) polarity reversal ∼771,000 years ago. Our high‐precision 40Ar/39Ar ages constrain several rapid and short‐lived changes in field orientation up to 33,000 years prior to the M‐B reversal. These changes are similar to ones identified in other less well‐dated lava flows in Maui, Chile, and La Palma that occurred during an extended period of reduced field strength recorded in sediments. We use a simple stochastic model to show that these rapid polarity changes are highly attenuated in sediment records with low sedimentation rates. This prolonged 33,000 year period of reduced field strength and increased geomagnetic instability supports models that show frequent centennial‐to‐millennial‐scale polarity changes in the presence of a strongly weakened dipole field.
Deriving Global Convection Maps From SuperDARN Measurements
Authors: Gjerloev J. W. , Waters C. L. , Barnes R. J.
Published: March 2018

A new statistical modeling technique for determining the global ionospheric convection is described. The principal component regression (PCR)‐based technique is based on Super Dual Auroral Radar Network (SuperDARN) observations and is an advanced version of the PCR technique that Waters et al. (, https//:doi.org.10.1002/2015JA021596) used for the SuperMAG data. While SuperMAG ground magnetic field perturbations are vector measurements, SuperDARN provides line‐of‐sight measurements of the ionospheric convection flow. Each line‐of‐sight flow has a known azimuth (or direction), which must be converted into the actual vector flow. However, the component perpendicular to the azimuth direction is unknown. Our method uses historical data from the SuperDARN database and PCR to determine a fill‐in model convection distribution for any given universal time. The fill‐in data process is driven by a list of state descriptors (magnetic indices and the solar zenith angle). The final solution is then derived from a spherical cap harmonic fit to the SuperDARN measurements and the fill‐in model. When compared with the standard SuperDARN fill‐in model, we find that our fill‐in model provides improved solutions, and the final solutions are in better agreement with the SuperDARN measurements. Our solutions are far less dynamic than the standard SuperDARN solutions, which we interpret as being due to a lack of magnetosphere‐ionosphere inertia and communication delays in the standard SuperDARN technique while it is inherently included in our approach. Rather, we argue that the magnetosphere‐ionosphere system has inertia that prevents the global convection from changing abruptly in response to an interplanetary magnetic field change.
Intervals of Intense Energetic Electron Beams Over Jupiter's Poles
Authors: Paranicas C. , Mauk B. H. , Haggerty D. K. , Clark G. , Kollmann P. , Rymer A. M. , Bonfond B. , Dunn W. R. , Ebert R. W. , Gladstone G. R. , Roussos E. , Krupp N. , Bagenal F. , Levin S. M. , Connerney J. E. P. , Bolton S. J.
Published: March 2018

Juno's Jupiter Energetic particle Detector Instrument often detects energetic electron beams over Jupiter's polar regions. In this paper, we document a subset of intense magnetic field‐aligned beams of energetic electrons moving away from Jupiter at high magnetic latitudes both north and south of the planet. The number fluxes of these beams are often dominated by electrons with energies above about 1 MeV. These very narrow beams can create broad angular responses in the Jupiter Energetic particle Detector Instrument with unique signatures in the detector count rates, probably because of >10 MeV electrons. We use these signatures to identify the most intense beams. These beams occur primarily above the swirl region of the polar cap aurora. This polar region is described as being of low brightness and high absorption and the most magnetically “open” at Jupiter.
On the Relationship Between Hydrogen Saturation in the Tropical Atlantic Ocean and Nitrogen Fixation by the Symbiotic Diazotroph UCYN‐A
Authors: Moore R. M. , Grefe I. , Zorz J. , Shan S. , Thompson K. , Ratten J. , LaRoche J.
Published: March 2018

Dissolved hydrogen measurements were made at high resolution in surface waters along a tropical north Atlantic transect between Guadeloupe and Cape Verde in 2015 (Meteor 116). Parallel water samples acquired to assess the relative abundance of the nifH gene from several types of diazotrophs, indicated that Trichodesmium and UCYN‐A were dominant in this region. We show that a high degree of correlation exists between the hydrogen saturations and UCYN‐A nifH abundance, and a weak correlation with Trichodesmium. The findings suggest that nitrogen fixation by UCYN‐A is a major contributor to hydrogen supersaturations in this region of the ocean. The ratio of hydrogen released to nitrogen fixed has not been determined for this symbiont, but the indications are that it may be high in comparison with the small number of diazotrophs for which the ratio has been measured in laboratory cultures. We speculate that this would be consistent with the diazotroph being an exosymbiont on its haptophyte host. Our high resolution measurements of hydrogen concentrations are capable of illustrating the time and space scales of inferred activity of diazotrophs in near real‐time in a way that cannot be achieved by biological sampling and rate measurements requiring incubations with 15N2. Direct measurement of high resolution spatial variability would be relatively challenging through collection and analysis of biological samples by qPCR, and extremely challenging by 15N‐uptake techniques, neither of which methods yields real‐time data. Nonetheless, determination of fixation rates still firmly depends on the established procedure of incubations in the presence of 15N2.
Ventilation of the Subtropical North Atlantic: Locations and Times of Last Ventilation Estimated Using Tracer Constraints From GEOTRACES Section GA03
Authors: Holzer Mark , Smethie William M. , Ting Yu‐Heng
Published: March 2018

The ventilation of the subtropical North Atlantic along GEOTRACES section GA03 is quantified in terms of where and how long ago water was last in the mixed layer. Measurements of T, S,
, CFC‐11, CFC‐12, SF6, and estimates of prebomb 14C are deconvolved for the boundary propagator
using a maximum‐entropy approach. From
, we calculate the fractions of water last ventilated in specified surface regions Ωw. We estimate that (56 ± 13)% of the water deeper than 1,000 m was ventilated in northern high latitudes, (15 ± 5)% in the Mediterranean, and (27 ± 12)% in the Southern Ocean. Below the thermocline and outside the deep western boundary current, mean ages of Ωw‐ventilated water exceed a century. Consequently, memory of where last ventilation occurred tends to get lost and the deep mean‐age patterns of Ωw‐ventilated water are broadly similar for all Ωw. The mean ventilation ages, averaged over the section with Ωw‐fraction weights, are roughly 200 years for all deep water masses except for water last ventilated south of the Antarctic divergence, which is about twice as old. The uncertainties in the section‐mean profiles of the Ωw fractions and their mean ages are ∼50% and ∼20%, respectively. The Ωw fractions have vertically diffuse overlapping patterns suggesting significant diapycnal mixing, consistent with century‐scale mean ages. We quantify the seasonal cycle of ventilation and find that in both hemispheres peak ventilation occurs during late winter and early spring, but Northern Hemisphere ventilated deep waters have a more pronounced seasonal cycle with nearly zero summertime ventilation.
An Accurate Fire‐Spread Algorithm in the Weather Research and Forecasting Model Using the Level‐Set Method
Authors: Muñoz‐Esparza Domingo , Kosović Branko , Jiménez Pedro A. , Coen Janice L.
Published: March 2018

The level‐set method is typically used to track and propagate the fire perimeter in wildland fire models. Herein, a high‐order level‐set method using fifth‐order WENO scheme for the discretization of spatial derivatives and third‐order explicit Runge‐Kutta temporal integration is implemented within the Weather Research and Forecasting model wildland fire physics package, WRF‐Fire. The algorithm includes solution of an additional partial differential equation for level‐set reinitialization. The accuracy of the fire‐front shape and rate of spread in uncoupled simulations is systematically analyzed. It is demonstrated that the common implementation used by level‐set‐based wildfire models yields to rate‐of‐spread errors in the range 10–35% for typical grid sizes (Δ = 12.5–100 m) and considerably underestimates fire area. Moreover, the amplitude of fire‐front gradients in the presence of explicitly resolved turbulence features is systematically underestimated. In contrast, the new WRF‐Fire algorithm results in rate‐of‐spread errors that are lower than 1% and that become nearly grid independent. Also, the underestimation of fire area at the sharp transition between the fire front and the lateral flanks is found to be reduced by a factor of ≈7. A hybrid‐order level‐set method with locally reduced artificial viscosity is proposed, which substantially alleviates the computational cost associated with high‐order discretizations while preserving accuracy. Simulations of the Last Chance wildfire demonstrate additional benefits of high‐order accurate level‐set algorithms when dealing with complex fuel heterogeneities, enabling propagation across narrow fuel gaps and more accurate fire backing over the lee side of no fuel clusters.
Nonrotating Convective Self‐Aggregation in a Limited Area AGCM
Authors: Arnold Nathan P. , Putman William M.
Published: March 2018

We present nonrotating simulations with the Goddard Earth Observing System (GEOS) atmospheric general circulation model (AGCM) in a square limited area domain over uniform sea surface temperature. As in previous studies, convection spontaneously aggregates into humid clusters, driven by a combination of radiative and moisture‐convective feedbacks. The aggregation is qualitatively independent of resolution, with horizontal grid spacing from 3 to 110 km, with both explicit and parameterized deep convection. A budget for the spatial variance of column moist static energy suggests that longwave radiative and surface flux feedbacks help establish aggregation, while the shortwave feedback contributes to its maintenance. Mechanism‐denial experiments confirm that aggregation does not occur without interactive longwave radiation. Ice cloud radiative effects help support the humid convecting regions but are not essential for aggregation, while liquid clouds have a negligible effect. Removing the dependence of parameterized convection on tropospheric humidity reduces the intensity of aggregation but does not prevent the formation of dry regions. In domain sizes less than (5,000 km)2, the aggregation forms a single cluster, while larger domains develop multiple clusters. Larger domains initialized with a single large cluster are unable to maintain them, suggesting an upper size limit. Surface wind speed increases with domain size, implying that maintenance of the boundary layer winds may limit cluster size. As cluster size increases, large boundary layer temperature anomalies develop to maintain the surface pressure gradient, leading to an increase in the depth of parameterized convective heating and an increase in gross moist stability.
Microfluidic Devices for Studying the Effect of Netrin‐1 on Neutrophil and Breast Cancer Cell Migration
Authors: Hipolito Jolly , Peretz‐Soroka Hagit , Torres Aniel Moya , Booy Evan , Yang Ke , Gupta Monika , Meier Markus , McKenna Sean , Koch Manuel , Santos Susy , Stetefeld Jörg , Lin Francis
Published: March 2018

Netrin‐1 is well‐known for its chemoattractive and chemorepulsive properties for axon guidance. Early studies report that netrin‐1 inhibits granulocyte migration. On the other hand, netrin‐1 can promote cancer cell migration and invasion. The underlying mechanisms are not well understood, which requires more in‐depth characterizations of netrin‐1 mediated immune and cancer cell migration. The present study, for the first time, employs microfluidic devices that are recently developed to quantitatively investigate the effects of netrin‐1 on the motility and chemotaxis of human blood neutrophils and human breast cancer cells under well‐controlled gradient conditions. The results show that netrin‐1 reduces chemokinetic motility of human neutrophils, which is accompanied with reduced cell polarization and spreading. In addition, netrin‐1 reduces neutrophil chemotaxis to N‐formyl‐Met‐Leu‐Phe on fibronectin substrate but interestingly not on collagen substrate. By contrast, netrin‐1 promotes the migration of human breast cancer cells. Furthermore, it is found that netrin‐1 reduces neutrophil chemotaxis to the supernatant of human breast cancer cell culture. Collectively, this microfluidic cell migration study provides quantitative characterizations of the effects of netrin‐1 on the motility and chemotaxis of neutrophils and breast cancer cells, and further suggests the potential role of netrin‐1 in regulating neutrophil recruitment to breast cancer microenvironments.
Carbon‐Dot‐Decorated TiO2 Nanotubes toward Photodynamic Therapy Based on Water‐Splitting Mechanism
Authors: Yang Dan , Yang Guixin , Sun Qianqian , Gai Shili , He Fei , Dai Yunlu , Zhong Chongna , Yang Piaoping
Published: March 2018

The use of visible light to produce reactive oxygen species (ROS) from renewable water splitting is a highly promising means in photodynamic therapy (PDT). Up to date, diverse inorganic–organic hybrid materials developed as photosensitizers still undergo low therapeutic efficiency and/or poor stability. Herein, a kind of carbon‐nanodot‐decorated TiO2 nanotubes (CDots/TiO2 NTs) composite is developed and applied for photodynamic therapy. Upon 650 nm laser light excitation, the emissions with short wavelengths (325–425 nm) from the CDots as a result of upconversion process excite TiO2 NTs to form electron/hole (e−/h+) pairs, triggering the reaction with the adsorbed oxidants to produce ROS. Moreover, the CDots deposited on the surface of TiO2 NTs markedly enhance the light absorption response and narrow the band gap compared with anatase TiO2 nanoparticles, thereby increasing the photosensitizing efficiency. Besides, the CDots show high chemical catalytic activity for H2O2 decomposition even if no light is needed, which is essential for PDT. The excellent therapeutic performance actuated by 650 nm light is demonstrated by in vitro and in vivo assays. This photosensitizer comprises low‐cost, earth‐abundant, environment‐friendly merits, and especially excellent stability, implying its feasible application in biomedical field.
Stability of High‐Performance Pt‐Based Catalysts for Oxygen Reduction Reactions
Authors: Lin Rui , Cai Xin , Zeng Hao , Yu Zhuoping
Published: March 2018

Due to their environmental sustainability and high efficiency, proton‐exchange‐membrane fuel cells (PEMFCs) are expected to be an essential type of energy source for electric vehicles, energy generation, and the space industry in the coming decades. Here, the recent developments regarding shape‐controlled nanostructure catalysts are reviewed, with a focus on the stability of high‐performance Pt‐based catalysts and related mechanisms. The catalysts, which possess great activity, are still far from meeting the requirements of their applications, due to stability issues, especially in membrane electrode assemblies (MEAs). Thus, solutions toward the comprehensive performance of Pt‐based catalysts are discussed here. The research trends and related theories that can promote the application of Pt‐based catalysts are also provided.
Dithieno[3,2‐b:2′,3′‐d]pyrrol Fused Nonfullerene Acceptors Enabling Over 13% Efficiency for Organic Solar Cells
Authors: Sun Jia , Ma Xiaoling , Zhang Zhuohan , Yu Jiangsheng , Zhou Jie , Yin Xinxing , Yang Linqiang , Geng Renyong , Zhu Rihong , Zhang Fujun , Tang Weihua
Published: March 2018

A new electron‐rich central building block, 5,5,12,12‐tetrakis(4‐hexylphenyl)‐indacenobis‐(dithieno[3,2‐b:2′,3′‐d]pyrrol) (INP), and two derivative nonfullerene acceptors (INPIC and INPIC‐4F) are designed and synthesized. The two molecules reveal broad (600–900 nm) and strong absorption due to the satisfactory electron‐donating ability of INP. Compared with its counterpart INPIC, fluorinated nonfullerene acceptor INPIC‐4F exhibits a stronger near‐infrared absorption with a narrower optical bandgap of 1.39 eV, an improved crystallinity with higher electron mobility, and down‐shifted highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels. Organic solar cells (OSCs) based on INPIC‐4F exhibit a high power conversion efficiency (PCE) of 13.13% and a relatively low energy loss of 0.54 eV, which is among the highest efficiencies reported for binary OSCs in the literature. The results demonstrate the great potential of the new INP as an electron‐donating building block for constructing high‐performance nonfullerene acceptors for OSCs.
Surface Chemistry of All Inorganic Halide Perovskite Nanocrystals: Passivation Mechanism and Stability
Authors: Yang Dandan , Li Xiaoming , Zeng Haibo
Published: March 2018

All inorganic halide perovskite (IHP) nanocrystals (NCs) have emerged as a new class of optoelectronic materials for various applications. Surface ligands as surface passivators are essential components of nucleation and growth processes, photoluminescence quantum yields (PL QY), stability, and photoelectric applications. In this review, the relationship of perovskite structure modified is outlined by surface ligand and some properties on account of the ion structure features. This review specifically focuses on the roles of surface ligands in the construction of IHP NCs with fewer defects, higher PL QY, and better stability. Generally, ligands binding to the surface of IHP NCs can form passivation layer, which are beneficial to not only the improvement of PL QY by filling the Br− or Pb2+ vacancy but also the enhancement of stability. The surface passivation mechanisms are attributed to the [Br⋯HN+] hydrogen‐bonding, chelation, and dative covalent bond interactions. Furthermore, degradation mechanisms assigned to the hydration, ion migration, and dissociation are discussed. The equilibrium problem of purifying and QY and possible reasons are also addressed, which are believed to be solved in the near future with the help of coordination chemistry and surface engineering. Finally, a brief outlook including challenges and possible development is provided.
Fiber‐Shaped ZnO/Graphene Schottky Photodetector with Strain Effect
Authors: Zhu Zhengfeng , Wang Shalong , Zhu Ying , Liu Xuhai , Zou Yousheng , Gu Yu , Ju Dan , Zeng Haibo
Published: March 2018

The flexible fiber‐shaped photodetectors (PDs) suitable for wearable applications have recently attracted enormous research attention. However, the fiber‐shaped structures with the PN junction usually suffer from the poor interface between the all‐inorganic semiconductors and twisted linear electrodes. In this work, fiber‐shaped ZnO/graphene PDs based on a Schottky junction are constructed for the first time. The PDs exhibit excellent device performance because of the combination of the interface and strain engineering. In this novel structure, ZnO nanorod arrays are uniformly grown onto the Zn wire, and a graphene film is wrapped outside as the surface electrode. The built‐in electric field and the conformal contacts facilitate the separation and transport of photoinduced charge carriers. The photoresponsivity is as high as 1.92 A W−1. Moreover, the device performance can be further improved by applying external compressive strain due to the piezoelectric effect of ZnO. For instance, the responsivity of the PD under −0.33% compressive strain can increase by 12.5% and reach 2.16 A W−1.
C70 Fullerene‐Catalyzed Metal‐Free Photocatalytic ipso‐Hydroxylation of Aryl Boronic Acids: Synthesis of Phenols
Authors: Kumar Inder , Sharma Ritika , Kumar Rakesh , Kumar Rakesh , Sharma Upendra
Published: March 2018

A metal‐free C70 fullerene‐catalyzed method has been developed for the ipso‐hydroxylation of aryl and heteroaryl boronic acids to corresponding phenols under photocatalytic conditions. The reaction proceeds under oxygen atmosphere and the mechanistic study revealed that C70 plays a critical role in the generation of reactive oxygen species in the presence of blue light. Reactions in the presence of 18O‐labelled water and oxygen confirmed the generation of reactive oxygen species from oxygen molecule. Amine used as a reductant could be recovered in the form of imine. The current method is also applicable to the synthesis of aryl ethers in one‐pot two‐step process.

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Xanthan Gum–Chitosan: Delayed, prolonged, and burst‐release tablets using same components in different ratio
Authors: Consumi Marco , Leone Gemma , Pepi Simone , Tamasi Gabriella , Lamponi Stefania , Donati Alessandro , Bonechi Claudia , Rossi Claudio , Magnani Agnese
Published: March 2018

Chitosan and xanthan gum were combined in nine different percentages without using any cross‐linking agent. The obtained physical matrices were able to give a burst, delayed, or prolonged release of red yeast rice (RYR) on the basis of xanthan gum percentage. In fact, thermal analysis, swelling behavior, and rheological analysis pointed out that a slight interaction among xanthan gum and RYR was present. This was reflected in a burst release when the amount of xanthan gum was under the 30%. On the contrary, a prolonged release was observed when the xanthan gum percent was higher than 70%. A delayed release was observed using similar percentage of the polymers (i.e., F5–F7). The effect of the formulation on RYR inhibition activity toward 3‐hydroxy‐3‐methyl‐glutaryl‐coenzyme A reductase and on cholesterol production was also evaluated.
Green‐Light‐Activated Photoreaction via Genetic Hybridization of Far‐Red Fluorescent Protein and Silk
Authors: Leem Jung Woo , Park Jongwoo , Kim Seong‐Wan , Kim Seong‐Ryul , Choi Seung Ho , Choi Kwang‐Ho , Kim Young L.
Published: March 2018

Fluorescent proteins often result in phototoxicity and cytotoxicity, in particular because some red fluorescent proteins produce and release reactive oxygen species (ROS). The photogeneration of ROS is considered as a detrimental side effect in cellular imaging or is proactively utilized for ablating cancerous tissue. As ancient textiles or biomaterials, silk produced by silkworms can directly be used as fabrics or be processed into materials and structures to host other functional nanomaterials. It is reported that transgenic fusion of far‐red fluorescent protein (mKate2) with silk provides a photosensitizer hybridization platform for photoinducible control of ROS. Taking advantage of green (visible) light activation, native and regenerated mKate2 silk can produce and release superoxide and singlet oxygen, in a comparable manner of visible light‐driven plasmonic photocatalysis. Thus, the genetic expression of mKate2 in silk offers immediately exploitable and scalable photocatalyst‐like biomaterials. It is further envisioned that mKate2 silk can potentially rule out hazardous concerns associated with foreign semiconductor photocatalytic nanomaterials.
How Low Nucleation Density of Graphene on CuNi Alloy is Achieved
Authors: Liu Yifan , Wu Tianru , Yin Yuling , Zhang Xuefu , Yu Qingkai , Searles Debra J. , Ding Feng , Yuan Qinghong , Xie Xiaoming
Published: March 2018

CuNi alloy foils are demonstrated to be one of the best substrates for synthesizing large area single‐crystalline graphene because a very fast growth rate and low nucleation density can be simultaneously achieved. The fast growth rate is understood to be due the abundance of carbon precursor supply, as a result of the high catalytic activity of Ni atoms. However, a theoretical understanding of the low nucleation density remains controversial because it is known that a high carbon precursor concentration on the surface normally leads to a high nucleation density. Here, the graphene nucleation on the CuNi alloy surfaces is systematically explored and it is revealed that: i) carbon atom dissolution into the CuNi alloy passivates the alloy surface, thereby drastically increasing the graphene nucleation barrier; ii) carbon atom diffusion on the CuNi alloy surface is greatly suppressed by the inhomogeneous atomic structure of the surface; and iii) a prominent increase in the rate of carbon diffusion into the bulk occurs when the Ni composition is higher than the percolation threshold. This study reveals the key mechanism for graphene nucleation on CuNi alloy surfaces and provides a guideline for the catalyst design for the synthesis of graphene and other 2D materials.
Microstructured Elastomer‐PEG Hydrogels via Kinetic Capture of Aqueous Liquid–Liquid Phase Separation
Authors: Lau Hang Kuen , Paul Alexandra , Sidhu Ishnoor , Li Linqing , Sabanayagam Chandran R. , Parekh Sapun H. , Kiick Kristi L.
Published: March 2018

Heterogeneous hydrogels with desired matrix complexity are studied for a variety of biomimetic materials. Despite the range of such microstructured materials described, few methods permit independent control over microstructure and microscale mechanics by precisely controlled, single‐step processing methods. Here, a phototriggered crosslinking methodology that traps microstructures in liquid–liquid phase‐separated solutions of a highly elastomeric resilin‐like polypeptide (RLP) and poly(ethylene glycol) (PEG) is reported. RLP‐rich domains of various diameters can be trapped in a PEG continuous phase, with the kinetics of domain maturation dependent on the degree of acrylation. The chemical composition of both hydrogel phases over time is assessed via in situ hyperspectral coherent Raman microscopy, with equilibrium concentrations consistent with the compositions derived from NMR‐measured coexistence curves. Atomic force microscopy reveals that the local mechanical properties of the two phases evolve over time, even as the bulk modulus of the material remains constant, showing that the strategy permits control of mechanical properties on micrometer length scales, of relevance in generating mechanically robust materials for a range of applications. As one example, the successful encapsulation, localization, and survival of primary cells are demonstrated and suggest the potential application of phase‐separated RLP‐PEG hydrogels in regenerative medicine applications.
Improving Miscibility of a Naphthalene Diimide‐Bithiophene Copolymer with n‐Type Dopants through the Incorporation of “Kinked” Monomers
Authors: Shin Younghun , Massetti Matteo , Komber Hartmut , Biskup Till , Nava Diego , Lanzani Guglielmo , Caironi Mario , Sommer Michael
Published: March 2018

N‐type doping of polymer semiconductors is necessary to enable printable and efficient organic thermoelectric generators. A recently reported method relies on blending air‐stable benzimidazole derivative dopant molecules with good electron transporting materials, such as the well‐known poly{[N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5′‐(2,2′‐bithiophene)}, also known as PNDIT2. One of the main limitations to doping efficiency is miscibility of the dopant with the polymer. In order to overcome such limitation, controlled amounts of the covalently incorporated, meta‐substituted monomer 1,3‐bis(2‐thienyl)benzene (TPT) (“kinked monomer”) are introduced into the otherwise straight backbone of PNDIT2. Differential scanning calorimetry shows that crystallinity of P(NDI‐alt‐[T2‐co‐TPT]) first decreases with increasing TPT content up to 5 mol%, but then increases again for higher TPT contents. Miscibility of P(NDI‐alt‐[T2‐co‐TPT]) with the dopant 4‐(1,3‐dimethyl‐2,3‐dihydro‐1H‐benzoimidazol‐2‐yl)‐N,N‐diphenylaniline increases with increasing TPT content up to 30 mol%. The electrical conductivity of doped P(NDI‐alt‐[T2‐co‐TPT]) films is reduced with respect to PNDIT2, owing to a lower charge mobility caused by TPT units which break conjugation. Nevertheless, the doping efficiency at high doping concentration is substantially improved, with an estimated ≈20‐fold increase with respect to PNDIT2, as a result of the improved miscibility of dopant and copolymer.
Transient Resistive Switching Memory of CsPbBr3 Thin Films
Authors: Lin Qiqi , Hu Wei , Zang Zhigang , Zhou Miao , Du Juan , Wang Ming , Han Shuai , Tang Xiaosheng
Published: March 2018

Recently, transient electronic devices play an indispensable role in modern disposable electronics and create potential application fields that cannot be addressed with conventional electronic devices or systems. However, the choice of transient materials has some limitations. It is therefore of great significance to explore transient electrodes, materials, and substrates that can undergo rapid and complete degradation on demand. In this work, the CsPbBr3 thin films as the switching layer are utilized to implement transient memory devices with a flexible Ag/CsPbBr3/PEDOT:PSS/ITO structure. This flexible nonvolatile memory device exhibits reproducible resistive switching performance, uniform switching voltages, concentrated distributions of high and low resistance states, and good mechanical stability over 50 bending times. The elemental mapping images of the memory device reveal that the resistive switching mechanism is interpreted through electrochemical formation/dissolution of metallic Ag filaments in CsPbBr3 layer. More importantly, it is demonstrated that the CsPbBr3 films and memory device can be dissolved rapidly in deionized water within 60 s, showing the transient characteristics. In addition, the optical and electrical properties disappear completely after the device dissolved in deionized water. This work demonstrates that the all‐inorganic perovskite CsPbBr3‐based transient memory devices have great potential for applications in secure data storage systems and disposable electronics.
The Scale‐up and Commercialization of Nonaqueous Na‐Ion Battery Technologies
Authors: Bauer Alexander , Song Jie , Vail Sean , Pan Wei , Barker Jerry , Lu Yuhao
Published: March 2018

This report provides an overview of development activities that enable the scale‐up and thereby a pathway toward the commercialization of sodium‐ion battery technologies for the energy storage market. The electrochemical performance of active materials and full cell performance of batteries developed by two startup companies, Novasis Energies, Inc. and Faradion Limited, are discussed in detail. Both companies offer low‐cost sodium‐ion battery chemistries with uniquely developed active materials that afford high rate capability and cycling stability. Their technologies are highly scalable due to the implementation of abundant and predominantly nontoxic elements and the ability to utilize common battery fabrication and manufacturing equipment. Both companies utilize active materials that are cost competitive compared to low‐cost lithium‐ion battery materials while exhibiting very similar specific capacity. In addition, improved safety characteristics with respect to operation and transportation distinguish the described sodium‐ion batteries from their incumbent lithium‐ion counterparts. The featured technology is particularly attractive for large‐scale energy storage applications.
High Power Magnetic Field Energy Harvesting through Amplified Magneto‐Mechanical Vibration
Authors: Kang Min Gyu , Sriramdas Rammohan , Lee Hyeon , Chun Jinsung , Maurya Deepam , Hwang Geon Tae , Ryu Jungho , Priya Shashank
Published: March 2018

Internet of Things (IoT) is driving the development of new generation of sensors, communication components, and power sources. Ideally, IoT sensors and communication components are expected to be powered by sustainable energy source freely available in the environment. Here, a breakthrough in this direction is provided by demonstrating high output power energy harvesting from very low amplitude stray magnetic fields, which exist everywhere, through magnetoelectric (ME) coupled magneto‐mechano‐electric (MME) energy conversion. ME coupled MME harvester comprised of multiple layers of amorphous magnetostrictive material, piezoelectric macrofiber composite, and magnetic tip mass, interacts with an external magnetic field to generate electrical energy. Comprehensive experimental investigation and a theoretical model reveal that both the magnetic torque generated through magnetic loading and amplification of magneto‐mechanical vibration by ME coupling contributes toward the generation of high electrical power from the stray magnetic field around power cables of common home appliances. The generated electrical power from the harvester is sufficient for operating microsensors (gyro, temperature, and humidity sensing) and wireless data transmission systems. These results will facilitate the deployment of IoT devices in emerging intelligent infrastructures.
A Flexible and Ultrahigh Energy Density Capacitor via Enhancing Surface/Interface of Carbon Cloth Supported Colloids
Authors: Liang Xitong , Chen Kunfeng , Xue Dongfeng
Published: March 2018

Pseudocapacitors are now reaching the energy density limits set by the surface redox reaction of their electrode materials, requiring new cation paradigms for a fast cation Faradaic reaction with high capacitance. In this work, a flexible and ultrahigh energy density capacitor is reported via enhancing surface/interface of active colloids and supported carbon cloth. A flexible asymmetrical capacitor assembled with Ni2+ colloidal cathode and Fe3+ colloidal anode displays a high energy density of 353 W h kg−1 at the power density of 2250 W kg−1, outperforming recent reported pseudocapacitors, and shows superior cycling stability after 10 000 charge–discharge cycles at current density of 30 A g−1. This work demonstrates that the optimized surface/interface of carbon cloth and colloids can lead to the enhancement of both stability and activity of colloidal electrode.
Fused‐Ring Electron Acceptor ITIC‐Th: A Novel Stabilizer for Halide Perovskite Precursor Solution
Authors: Qin Minchao , Cao Jie , Zhang Tiankai , Mai Jiangquan , Lau Tsz‐Ki , Zhou Shu , Zhou Yang , Wang Jiayu , Hsu Yao‐Jane , Zhao Ni , Xu Jianbin , Zhan Xiaowei , Lu Xinhui
Published: March 2018

Solution‐processed perovskite solar cells have great potential for low‐cost roll‐to‐roll fabrication. However, the degradation of aged precursor solutions will become a critical obstacle to mass production. In this report, a small molecule (ITIC‐Th) is employed to stabilize the perovskite precursor solution containing mixed cations and halides. It is found that ITIC‐Th can effectively suppress the formation of yellow δ‐phase in the films made from aged precursor solutions. Consequently, the devices fabricated from the aged precursor solution with ITIC‐Th experience much less efficiency drop with the increase of the precursor aging time—from 19.20% (fresh) to 16.55% (39 d), compared with the devices made from conventional precursor solutions dropping from 18.07% (fresh) to 1.76% (39 d). The characterizations suggest that ITIC‐Th is beneficial for CH3NH3+ cations to be incorporated into the crystal structure, facilitating the formation of perovskite phase. Furthermore, the presence of ITIC‐Th in the perovskite thin film gives rise to additional photocurrent as well as improved fill factor due to the well‐matched energy levels, the passivation of defects, and the complementary absorption spectra, suggesting a new route toward future high‐efficiency solar cells—incorporating organic non‐fullerene acceptors and halide perovskite materials into the same active layer.