bluuebunny/crossref_metadata_2025 huggingface dataset:
Cassini plasma observations of Saturn's magnetospheric cusp
Authors: Jasinski Jamie M. , Arridge Christopher S. , Coates Andrew J. , Jones Geraint H. , Sergis Nick , Thomsen Michelle F. , Reisenfeld Daniel B. , Krupp Norbert , Waite J. Hunter
Published: November 2016

The magnetospheric cusp is a funnel‐shaped region where shocked solar wind plasma is able to enter the high‐latitude magnetosphere via the process of magnetic reconnection. The plasma observations include various cusp signatures such as ion energy dispersions and diamagnetic effects. We present an overview analysis of cusp plasma observations at the Saturnian magnetosphere from the Cassini spacecraft era. A comparison of the observations is made as well as classification into groups due to varying characteristics. The locations of the reconnection site are calculated and shown to vary along the subsolar magnetopause. We show the first in situ evidence for lobe reconnection that occurred at nearly the same time as dayside reconnection for one of the cusp crossings. Evidence for “bursty” and more “continuous” reconnection signatures is observed at different cusp events. The events are compared to solar wind propagation models, and it is shown that magnetic reconnection and plasma injection into the cusp can occur for a variety of upstream conditions. These are important results because they show that Saturn's magnetospheric interaction with the solar wind and the resulting cusp signatures are dynamic and that plasma injection in the cusp occurs due to a variety of solar wind conditions. Furthermore, reconnection can proceed at a variety of locations along the magnetopause.
Comparison of Van Allen Probes radiation belt proton data with test particle simulation for the 17 March 2015 storm
Authors: Engel M. A. , Kress B. T. , Hudson M. K. , Selesnick R. S.
Published: November 2016

The loss of protons in the outer part of the inner radiation belt (L = 2 to 3) during the 17 March 2015 geomagnetic storm was investigated using test particle simulations that follow full Lorentz trajectories with both magnetic and electric fields calculated from an empirical model. The simulation results presented here are compared with proton pitch angle measurements from the Van Allen Probe satellites Relativistic Electron Proton Telescope (REPT) instrument before and after the coronal mass ejection‐shock‐driven storm of 17–18 March 2015, with minimum Dst =− 223 nT, the strongest storm of Solar Cycle 24, for four different energy ranges with 30, 38, 50, and 66 MeV mean energies. Two simulations have been run, one with an inductive electric field and one without. All four energy channels show good agreement with the Van Allen Probes REPT measurements for low L (L < 2.4) in both simulations but diverge for higher L values. The inclusion of the inductive electric field, calculated from the time‐changing magnetic field, significantly improves the agreement between simulation and REPT measurements at L > 2.4. A previous study using the Highly Elliptical Orbiter 3 spacecraft also showed improved agreement when including the inductive electric field but was unable to compare effects on the pitch angle distributions.
A simple lightning assimilation technique for improving retrospective WRF simulations
Authors: Heath Nicholas K. , Pleim Jonathan E. , Gilliam Robert C. , Kang Daiwen
Published: November 2016

Convective rainfall is often a large source of error in retrospective modeling applications. In particular, positive rainfall biases commonly exist during summer months due to overactive convective parameterizations. In this study, lightning assimilation was applied in the Kain‐Fritsch (KF) convective scheme to improve retrospective simulations using the Weather Research and Forecasting (WRF) model. The assimilation method has a straightforward approach: force KF deep convection where lightning is observed and, optionally, suppress deep convection where lightning is absent. WRF simulations were made with and without lightning assimilation over the continental United States for July 2012, July 2013, and January 2013. The simulations were evaluated against NCEP stage‐IV precipitation data and MADIS near‐surface meteorological observations. In general, the use of lightning assimilation considerably improves the simulation of summertime rainfall. For example, the July 2012 monthly averaged bias of 6 h accumulated rainfall is reduced from 0.54 to 0.07 mm and the spatial correlation is increased from 0.21 to 0.43 when lightning assimilation is used. Statistical measures of near‐surface meteorological variables also are improved. Consistent improvements also are seen for the July 2013 case. These results suggest that this lightning assimilation technique has the potential to substantially improve simulation of warm‐season rainfall in retrospective WRF applications.
Optimizing significance testing of astronomical forcing in cyclostratigraphy
Authors: Kemp David B.
Published: November 2016

The recognition of astronomically forced (Milankovitch) climate cycles in geological archives marked a major advance in Earth science, revealing a heartbeat within the climate system of general importance and key utility. Power spectral analysis is the primary tool used to facilitate identification of astronomical cycles in stratigraphic data, but commonly employed methods for testing the statistical significance of relatively high narrow‐band variance of potential astronomical origin in spectra have been criticized for inadequately balancing the respective probabilities of type I (false positive) and type II (false negative) errors. This has led to suggestions that the importance of astronomical forcing in Earth history is overstated. It can be readily demonstrated, however, that the imperfect nature of the stratigraphic record and the quasiperiodicity of astronomical cycles sets an upper limit on the attainable significance of astronomical signals. Optimized significance testing is that which minimizes the combined probability of type I and type II errors. Numerical simulations of stratigraphically preserved astronomical signals suggest that optimum significance levels at which to reject a null hypothesis of no astronomical forcing are between 0.01 and 0.001 (i.e., 99–99.9% confidence level). This is lower than commonly employed in the literature (90–99% confidence levels). Nevertheless, in consonance with the emergent view from other scientific disciplines, fixed‐value null hypothesis significance testing of power spectra is implicitly ill suited to demonstrating astronomical forcing, and the use of spectral analysis remains a difficult and subjective endeavor in the absence of additional supporting evidence.
Bounded fractional diffusion in geological media: Definition and Lagrangian approximation
Authors: Zhang Yong , Green Christopher T. , LaBolle Eric M. , Neupauer Roseanna M. , Sun HongGuang
Published: November 2016

Spatiotemporal fractional‐derivative models (FDMs) have been increasingly used to simulate non‐Fickian diffusion, but methods have not been available to define boundary conditions for FDMs in bounded domains. This study defines boundary conditions and then develops a Lagrangian solver to approximate bounded, one‐dimensional fractional diffusion. Both the zero‐value and nonzero‐value Dirichlet, Neumann, and mixed Robin boundary conditions are defined, where the sign of Riemann‐Liouville fractional derivative (capturing nonzero‐value spatial‐nonlocal boundary conditions with directional superdiffusion) remains consistent with the sign of the fractional‐diffusive flux term in the FDMs. New Lagrangian schemes are then proposed to track solute particles moving in bounded domains, where the solutions are checked against analytical or Eulerian solutions available for simplified FDMs. Numerical experiments show that the particle‐tracking algorithm for non‐Fickian diffusion differs from Fickian diffusion in relocating the particle position around the reflective boundary, likely due to the nonlocal and nonsymmetric fractional diffusion. For a nonzero‐value Neumann or Robin boundary, a source cell with a reflective face can be applied to define the release rate of random‐walking particles at the specified flux boundary. Mathematical definitions of physically meaningful nonlocal boundaries combined with bounded Lagrangian solvers in this study may provide the only viable techniques at present to quantify the impact of boundaries on anomalous diffusion, expanding the applicability of FDMs from infinite domains to those with any size and boundary conditions.
Comparison of static and dynamic resilience for a multipurpose reservoir operation
Authors: Simonovic Slobodan P. , Arunkumar R.
Published: November 2016

Reliability, resilience, and vulnerability are the traditional risk measures used to assess the performance of a reservoir system. Among these measures, resilience is used to assess the ability of a reservoir system to recover from a failure event. However, the time‐independent static resilience does not consider the system characteristics, interaction of various individual components and does not provide much insight into reservoir performance from the beginning of the failure event until the full performance recovery. Knowledge of dynamic reservoir behavior under the disturbance offers opportunities for proactive and/or reactive adaptive response that can be selected to maximize reservoir resilience. A novel measure is required to provide insight into the dynamics of reservoir performance based on the reservoir system characteristics and its adaptive capacity. The reservoir system characteristics include, among others, reservoir storage curve, reservoir inflow, reservoir outflow capacity, and reservoir operating rules. The reservoir adaptive capacity can be expressed using various impacts of reservoir performance under the disturbance (like reservoir release for meeting a particular demand, socioeconomic consequences of reservoir performance, or resulting environmental state of the river upstream and downstream from the reservoir). Another way of expressing reservoir adaptive capacity to a disturbing event may include aggregated measures like reservoir robustness, redundancy, resourcefulness, and rapidity. A novel measure that combines reservoir performance and its adaptive capacity is proposed in this paper and named “dynamic resilience.” The paper also proposes a generic simulation methodology for quantifying reservoir resilience as a function of time. The proposed resilience measure is applied to a single multipurpose reservoir operation and tested for a set of failure scenarios. The dynamic behavior of reservoir resilience is captured using the system dynamics simulation approach, a feedback‐based object‐oriented method, very effective for modeling complex systems. The results of dynamic resilience are compared with the traditional performance measures in order to identify advantages of the proposed measure. The results confirm that the dynamic resilience is a powerful tool for selecting proactive and reactive adaptive response of a multipurpose reservoir to a disturbing event that cannot be achieved using traditional measures. The generic quantification approach proposed in the paper allows for easy use of dynamic resilience for planning and operations of various civil infrastructure systems.
Network Meta‐Analysis
Authors: Rücker Gerta
Published: November 2016

Network meta‐analysis is an extension of pairwise meta‐analysis, mainly applied in healthcare. It is used to compare three or more treatments for a given medical condition, based on combining information from all existing randomized comparisons among the treatments. To combine direct and indirect evidence, it is assumed that the studies are independent, the underlying effects are consistent, and the differences between them are only due to random error. For estimation, Bayesian or frequentist methods (weighted least squares regression) can be applied, while adjusting for multiarm studies. Similar to in pairwise meta‐analysis, fixed and random effects models may be used, and heterogeneity should be explored.
Flexible, Graphene‐Coated Biocomposite for Highly Sensitive, Real‐Time Molecular Detection
Authors: Wang Lili , Jackman Joshua A. , Ng Wei Beng , Cho Nam‐Joon
Published: November 2016

Wearable biosensors hold significant potential for healthcare and environmental applications, and the development of flexible and biocompatible sensing platforms for high accuracy detection of physiological biomarkers remains an elusive goal. Herein, an ultrasensitive, flexible sensor is described that is based on a 3D hierarchical biocomposite comprised of hollow, natural pollen microcapsules that are coated with a conductive graphene layer. Modular assembly of the graphene‐coated microcapsules onto an ultrathin polyethylene terephthalate layer enables a highly flexible sensor configuration with tunable selectivity afforded by subsequent covalent immobilization of antibodies against target antigens. In a proof‐of‐concept example, the biosensor demonstrates ultrahigh sensitivity detection of prostate specific antigen (PSA) down to 1.7 × 10−15m with real‐time feedback and superior performance over conventional 2D graphene‐coated sensors. Importantly, the device performance is consistently high across various bending conditions. Taken together, the results demonstrated in this work highlight the merits of employing lightweight biocomposites as modular building blocks for the design of flexible biosensors with highly responsive and sensitive molecular detection capabilities.
Synergistic Effect of Hybrid PbS Quantum Dots/2D‐WSe2 Toward High Performance and Broadband Phototransistors
Authors: Hu Chao , Dong Dongdong , Yang Xiaokun , Qiao Keke , Yang Dun , Deng Hui , Yuan Shengjie , Khan Jahangeer , Lan Yang , Song Haisheng , Tang Jiang
Published: November 2016

The transitionmetal dichalcogenides‐based phototransistors have demonstrated high transport mobility but are limited to poor photoresponse, which greatly blocks their applications in optoelectronic fields. Here, light sensitive PbS colloidal quantum dots (QDs) combined with 2D WSe2 to develop hybrid QDs/2D‐WSe2 phototransistors for high performance and broadband photodetection are utilized. The device shows a responsivity up to 2 × 105 A W–1, which is orders of magnitude higher than the counterpart of individual material‐based devices. The detection spectra of hybrid devices can be extended to near infrared similar to QDs' response. The high performance of hybrid 0D‐2D phototransistor is ascribed to the synergistic function of photogating effect. PbS QDs can efficiently absorb the input illumination and 2D WSe2 supports a transport expressway for injected photocarriers. The hybrid phototransistors obtain a specific detectivity over 1013 Jones in both ON and OFF state in contrast to the depleted working state (OFF) for other reported QDs/2D phototransistors. The present device construction strategy, photogating enhanced performance, and robust device working conditions contain high potential for future optoelectronic devices.
Assembly and Electronic Applications of Colloidal Nanomaterials
Authors: Zhu Jian , Hersam Mark C.
Published: November 2016

Artificial solids and thin films assembled from colloidal nanomaterials give rise to versatile properties that can be exploited in a range of technologies. In particular, solution‐based processes allow for the large‐scale and low‐cost production of nanoelectronics on rigid or mechanically flexible substrates. To achieve this goal, several processing steps require careful consideration, including nanomaterial synthesis or exfoliation, purification, separation, assembly, hybrid integration, and device testing. Using a ubiquitous electronic device – the field‐effect transistor – as a platform, colloidal nanomaterials in three electronic material categories are reviewed systematically: semiconductors, conductors, and dielectrics. The resulting comparative analysis reveals promising opportunities and remaining challenges for colloidal nanomaterials in electronic applications, thereby providing a roadmap for future research and development.
3D Hierarchical Indium Tin Oxide Nanotrees for Enhancement of Light Extraction in GaN‐Based Light‐Emitting Diodes
Authors: Park Min Joo , Kim Chan Ul , Kang Sung Bum , Won Sang Hyuk , Kwak Joon Seop , Kim Chil‐Min , Choi Kyoung Jin
Published: November 2016

Recently, 3D nanostructures have attracted much interest because of their interesting electrical/optical properties such as wave guiding modes, light scattering, antireflection effects, etc. In this work, a facile yet efficient method for the fabrication of hierarchical 3D indium tin oxide (ITO) nanotrees (NTs) and their integration in GaN‐based blue‐light‐emitting diodes (LEDs) for efficient light‐extraction are reported. The ITO NTs are fabricated by the oblique‐angle (≈85°) deposition method at 240 °C using electron‐beam evaporation. The ITO NTs grow via a self‐catalytic vapor–liquid–solid mechanism with the branches having an epitaxial relationship with the trunks. The ITO NTs successively deposited on an ITO thin film as a p‐contact layer are annealed at 600 °C for 1 min under ambient air in order to form a transparent ohmic contact. The indium gallium nitrde/gallium nitride (InGaN/GaN) LED with ITO NTs presents a 29.5% enhancement in the light output power at an injection current of 20 mA, compared to the reference LED with an ITO thin film p‐contact. This enhancement is ascribed to the effective light extraction of the ITO NTs due to to the gradually decreasing profile of the refractive index from 2.08 (ITO thin film), 1.15 (dense ITO NTs), 1.06 (porous ITO NTs) to 1.0 (air). These results are in good agreement with the optical simulation by the COMSOL wave optics module.
A Novel Strategy to Suppress Capacity and Voltage Fading of Li‐ and Mn‐Rich Layered Oxide Cathode Material for Lithium‐Ion Batteries
Authors: Zhang Shiming , Gu Haitao , Pan Hongge , Yang Suhui , Du Wubin , Li Xiang , Gao Mingxia , Liu Yongfeng , Zhu Min , Ouyang Liuzhang , Jian Dechao , Pan Feng
Published: November 2016

Poor cycling stability is one of the key scientific issues needing to be solved for Li‐ and Mn‐rich layered oxide cathode. In this paper, sodium carboxymethyl cellulose (CMC) is first used as a novel binder in Li1.2Ni0.13Co0.13Mn0.54O2 cathode to enhance its cycling stability. Electrochemical performance is conducted by galvanostatic charge and discharge. Structure and morphology are characterized by X‐ray diffraction, scanning electronic microscopy, high‐resolution transmission electron microscopy, and X‐ray photoelectron spectroscopy. Results reveal that the CMC as binder can not only stabilize the electrode structure by preventing the electrode materials to detach from the current collector but also suppress the voltage fading of the Li1.2Ni0.13Co0.13Mn0.54O2 cathode due to Na+ ions doping. Most importantly, the dissolution of metal elements from the cathode materials into the electrolyte is also inhibited.
Investigating the liquid film characteristics of gas–liquid swirling flow using ultrasound doppler velocimetry
Authors: Liang Fachun , Fang Zhaojun , Chen Jing , Sun Shitao
Published: November 2016

A novel gas–liquid two‐phase flow metering method was proposed. A spiral vane mounted in the inner pipe was used to transform inlet flow patterns into gas–liquid swirling annular flow. The thickness and velocity profile of liquid film were measured by ultrasound Doppler velocimetry. The liquid flow rates were obtained by integrating of velocity profile during the liquid film zone. Experiments were carried out in an air–water two‐phase flow loop and an ultrasonic transducer was installed under the bottom of the test section with the Doppler angle of 70°. The flow patterns included stratified wavy, annular, and slug flows. Compared with non‐swirling flow, the liquid film thickness at the bottom reduces greatly. The measurement accuracy of liquid flow rate was independent of inlet flow patterns, gas and liquid velocities. © 2016 American Institute of Chemical Engineers AIChE J, 63: 2348–2357, 2017
Experimental investigation of gas‐liquid flow in monolith channels using monofiber optical probes
Authors: Chugh Deepali , Roy Shantanu , Shao Jianbin , Al‐Dahhan Muthanna H.
Published: November 2016

Two‐phase hydrodynamics has been experimentally investigated using optical fibre probes in individual channels of a laboratory scale monolith bed. Experimental investigations were carried out to validate the optical probe measurements in a single capillary. Optical probes were positioned at selected single channels of a monolith block, and the signals were processed to assess the local hydrodynamics under cocurrent gas‐liquid downflow configuration, using air and water as fluids. The investigations were performed for three different distributors, viz. single pipe, multipipe, and packed bed distributor configurations. The different distributor configurations were evaluated on the basis of void fraction and bubble frequency for a wide range of flow velocities. The specific novelty aspect of this study comes from the fact that we have undertaken channel scale investigations in monoliths under conditions where we have also reported the global gas‐liquid distribution. Thus, one can readily correlate the bed‐scale hydrodynamics with the local channel‐scale hydrodynamics. © 2016 American Institute of Chemical Engineers AIChE J, 63: 327–336, 2017
Pulmonary abnormalities as a result of exposure to Libby amphibole during childhood and adolescence—The Pre‐Adult Latency Study (PALS)
Authors: Szeinuk Jaime , Noonan Curtis W. , Henschke Claudia I. , Pfau Jean , Black Brad , Miller Albert , Yankelevitz David F. , Liang Mingzhu , Liu Ying , Yip Rowena , Linker Laura , McNew Tracy , Flores Raja M.
Published: November 2016

Background

The purpose of Pre‐Adult Latency Study was to evaluate lung findings among adults who had been environmentally exposed to Libby Amphibole only during childhood and adolescence.

Methods

Recruitment was restricted to volunteers who attended primary and/or secondary school, lived in Libby, MT, prior to age 23 years for males and 21 years for females and subsequently left the area. Subjects completed exposure and respiratory questionnaires, underwent pulmonary function tests (PFTs), and chest CT scans. A Pleural Score was calculated for degree and extent of pleural thickening. Logistic regression and multivariate linear regression were used.

Results

Of the 219 who met inclusion criteria, 198 participated. Pleural thickening was found in 96 (48%) of 198 participants. In almost half of these, it was of the lamellar type, not generally seen in exposure to other asbestos. Environmental Libby amphibole exposure was associated with pleural thickening, and the likelihood of pleural thickening increased with the number of years lived in the area. An inverse association between Pleural Score and PFT was found, which remained significant for FVC and DLco after additional sensitivity analyses.

Conclusions

Cumulative environmental exposure was associated with risk of pleural thickening. Among this cohort, quantitative measures of pleural thickening were associated with decreased PFT. Am. J. Ind. Med. 60:20–34, 2017. © 2016 Wiley Periodicals, Inc.
De novo microdeletions and point mutations affecting SOX2 in three individuals with intellectual disability but without major eye malformations
Authors: Dennert Nicola , Engels Hartmut , Cremer Kirsten , Becker Jessica , Wohlleber Eva , Albrecht Beate , Ehret Julia K. , Lüdecke Hermann‐Josef , Suri Mohnish , Carignani Giulia , Renieri Alessandra , Kukuk Guido M. , Wieland Thomas , Andrieux Joris , Strom Tim M. , Wieczorek Dagmar , Dieux‐Coëslier Anne , Zink Alexander M.
Published: November 2016

Loss‐of‐function mutations and deletions of the SOX2 gene are known to cause uni‐ and bilateral anophthalmia and microphthalmia as well as related disorders such as anophthalmia‐esophageal‐genital syndrome. Thus, anophthalmia/microphthalmia is the primary indication for targeted, “phenotype first” analyses of SOX2. However, SOX2 mutations are also associated with a wide range of non‐ocular abnormalities, such as postnatal growth retardation, structural brain anomalies, hypogenitalism, and developmental delay. The present report describes three patients without anophthalmia/microphthalmia and loss‐of‐function mutations or microdeletions of SOX2 who had been investigated in a “genotype first” manner due to intellectual disability/developmental delay using whole exome sequencing or chromosomal microarray analyses. This result prompted us to perform SOX2 Sanger sequencing in 192 developmental delay/intellectual disability patients without anophthalmia or microphthalmia. No additional SOX2 loss‐of‐function mutations were detected in this cohort, showing that SOX2 is clearly not a major cause of intellectual disability without anophthalmia/microphthalmia. In our three patients and four further, reported “genotype first” SOX2 microdeletion patients, anophthalmia/microphthalmia was present in less than half of the patients. Thus, SOX2 is another example of a gene whose clinical spectrum is broadened by the generation of “genotype first” findings using hypothesis‐free, genome‐wide methods. © 2016 Wiley Periodicals, Inc.
Dietary habits in New France during the 17th and 18th centuries: An isotopic perspective
Authors: Vigeant J. , Ribot I. , Hélie J.‐F.
Published: November 2016

Objective

Little attention has been given, so far, to the early colonial diet in New France from an isotopic perspective. Historical records that compare France to New France suggest a shift toward a more diverse diet, including a higher protein intake due to an improvement in living conditions in the New World, despite the retention of ancestral dietary habits. This hypothesis will be explored here.

Materials and methods

Stable carbon (organic and mineral) and nitrogen isotopes were measured on 43 individuals from Notre Dame cemetery (first Catholic parish church cemetery in Montreal, 1683–1803) as well as 13 French compatriots from La Rochelle, France (Protestant Hospital Cemetery, 1765–1792). Intragroup variation (age at death, sex, and/or burial location) was investigated and compared to compiled data from various northeastern North American sites (N = 99).

Results

The Notre Dame sample means are as follows: −19.6‰ versus VPDB for δ13Ccollagen, −12.22‰ versus VPDB for δ13Ccarbonate, and 11.5‰ versus AIR for δ15N. They are significantly lower than both La Rochelle (−18.4‰, −11.67‰, and 12.7‰, respectively, p ≤ .005) and the northeastern North American groups used for this comparison (p = .000).

Discussion

The isotopic values obtained from Notre Dame cemetery suggest that the diet was mainly based on C3 resources with limited C4 resources. Although different from all comparable contemporary sites, colonial Montreal's diet remains most similar to La Rochelle, France. This study agrees with historians who have suggested that French dietary traditions seem to have been retained among the early colonial inhabitants of Montreal.
Malformations of cortical development
Authors: Desikan Rahul S. , Barkovich A. James
Published: November 2016

Malformations of cortical development (MCDs) compose a diverse range of disorders that are common causes of neurodevelopmental delay and epilepsy. With improved imaging and genetic methodologies, the underlying molecular and pathobiological characteristics of several MCDs have been recently elucidated. In this review, we discuss genetic and molecular alterations that disrupt normal cortical development, with emphasis on recent discoveries, and provide detailed radiological features of the most common and important MCDs. Ann Neurol 2016;80:797–810
Induction of Strong Long‐Lived Room‐Temperature Phosphorescence of N‐Phenyl‐2‐naphthylamine Molecules by Confinement in a Crystalline Dibromobiphenyl Matrix
Authors: Wei Jinbei , Liang Baoyan , Duan Ruihong , Cheng Zong , Li Chenglong , Zhou Tianlei , Yi Yuanping , Wang Yue
Published: November 2016

The design and preparation of metal‐free organic materials that exhibit room‐temperature phosphorescence (RTP) is a very attractive topic owing to potential applications in organic optoelectronic devices. Herein, we present a facile approach to efficient and long‐lived organic RTP involving the doping of N‐phenylnaphthalen‐2‐amine (PNA) or its derivatives into a crystalline 4,4′‐dibromobiphenyl (DBBP) matrix. The resulting materials showed strong and persistent RTP emission with a quantum efficiency of approximately 20 % and a lifetime of a few to more than 100 milliseconds. Bright white dual emission containing blue fluorescence and yellowish‐green RTP from the PNA‐doped DBBP crystals was also confirmed by Commission Internationale de l'Eclairage (CIE) coordinates of (x=0.29–0.31, y=0.38–0.41).
Preparation of Vinyl Arenes by Nickel‐Catalyzed Reductive Coupling of Aryl Halides with Vinyl Bromides
Authors: Liu Jiandong , Ren Qinghua , Zhang Xinghua , Gong Hegui
Published: November 2016

This work emphasizes the synthesis of substituted vinyl arenes by reductive coupling of aryl halides with vinyl bromides under mild and easy‐to‐operate nickel‐catalyzed reaction conditions. A broad range of aryl halides, including heteroaromatics, and vinyl bromides were employed to yielding products in moderate to excellent yields with high functional‐group tolerance. The nickel‐catalytic system displays good chemoselectivity between the two C(sp2)‐halide coupling partners, thus demonstrating a mechanistic pathway distinct from other stepwise protocols.
Palladium‐Catalyzed Fluorination of Cyclic Vinyl Triflates: Effect of TESCF3 as an Additive
Authors: Ye Yuxuan , Takada Takashi , Buchwald Stephen L.
Published: November 2016

A method for the palladium‐catalyzed fluorination of cyclic vinyl triflates has been developed. As with several previous palladium‐catalyzed fluorination reactions using fluoride salts, controlling the regioselectivity presented a challenge in developing a practical synthetic procedure. The addition of triethyl(trifluoromethyl)silane (TESCF3) was found to effectively address this problem and resulted in drastically improved regioselectivities in this palladium‐catalyzed fluorination reaction. This discovery, along with the use of a new biarylphosphine ligand, allowed for the development of an efficient and highly regioselective protocol for the fluorination of vinyl triflates. This method is compatible with a range of sensitive functional groups and provides access to five‐, six‐, and seven‐membered cyclic vinyl fluorides.
Alkenyl Arenes as Dipolarophiles in Catalytic Asymmetric 1,3‐Dipolar Cycloaddition Reactions of Azomethine Ylides
Authors: Pascual‐Escudero Ana , de Cózar Abel , Cossío Fernando P. , Adrio Javier , Carretero Juan C.
Published: November 2016

The use of alkenyl arenes as dipolarophiles in the catalytic asymmetric 1,3‐dipolar cycloaddition of azomethine ylides is reported. Under appropriate reaction conditions with a CuI or AgI catalyst either the exo or the endo adduct was obtained with high stereoselectivity. This process provides efficient access to highly enantiomerically enriched 4‐aryl proline derivatives. The observed results are compatible with the blockage of one prochiral face of the 1,3‐dipole, as well as with the efficient transmission of electrophilicity towards the terminal carbon atom of the dipolarophile. This polarization results in a change from a concerted to a stepwise mechanism.
Self‐Sorting of Two Hydrocarbon Receptors with One Carbonaceous Ligand
Authors: Matsuno Taisuke , Sato Sota , Yokoyama Atsutoshi , Kamata Sho , Isobe Hiroyuki
Published: November 2016

Non‐directional van der Waals forces in biological and synthetic supramolecular systems play important roles in molecular assembly, particularly in determining the distances of the interacting species. The van der Waals forces are normally used in combination with other directional forces and are considered to play a secondary role in achieving specificity and fidelity in molecular recognition. Using an ideal supramolecular system consisting solely of hydrogen and carbon atoms, we found that the van der Waals interactions enable the high‐fidelity sorting of two homomeric receptors during ligand‐induced assembly. The self‐sorting occurred in a narcissistic manner by repulsion of a competing diastereoisomeric receptor from the assembly. The structure–sorting relationship study with enantiomers further revealed the dominant role of the van der Waals forces in shape recognition for high‐fidelity self‐sorting.
Instantaneous Functionalization of Chemically Etched Silicon Nanocrystal Surfaces
Authors: Mobarok Md Hosnay , Purkait Tapas K. , Islam Muhammad Amirul , Miskolzie Mark , Veinot Jonathan G. C.
Published: November 2016

Remarkable advances in surface hydrosilylation reactions of C=C and C=O bonds on hydride‐terminated silicon have revolutionized silicon surface functionalization. However, existing methods for functionalizing hydride‐terminated Si nanocrystals (H‐SiNCs) require long reaction times and elevated temperatures. Herein, we report a room‐temperature method for functionalizing H‐SiNC surfaces within seconds by stripping outermost atoms on H‐SiNC surfaces with xenon difluoride (XeF2). Detailed analysis of the reaction byproducts by in situ NMR spectroscopy and GC‐MS provided unprecedented insight into NC surface composition and reactivity as well as the complex reaction mechanism of XeF2 activated hydrosilylation.
Copper Catalysis in Living Systems and In Situ Drug Synthesis
Authors: Clavadetscher Jessica , Hoffmann Scott , Lilienkampf Annamaria , Mackay Logan , Yusop Rahimi M. , Rider Sebastien A. , Mullins John J. , Bradley Mark
Published: November 2016

The copper‐catalyzed azide–alkyne cycloaddition (CuAAC) reaction has proven to be a pivotal advance in chemical ligation strategies with applications ranging from polymer fabrication to bioconjugation. However, application in vivo has been limited by the inherent toxicity of the copper catalyst. Herein, we report the application of heterogeneous copper catalysts in azide–alkyne cycloaddition processes in biological systems ranging from cells to zebrafish, with reactions spanning from fluorophore activation to the first reported in situ generation of a triazole‐containing anticancer agent from two benign components, opening up many new avenues of exploration for CuAAC chemistry.
Synthesis of Chiral Aminocyclopropanes by Rare‐Earth‐Metal‐Catalyzed Cyclopropene Hydroamination
Authors: Teng Huai‐Long , Luo Yong , Wang Baoli , Zhang Liang , Nishiura Masayoshi , Hou Zhaomin
Published: November 2016

The search for efficient and selective routes for the synthesis of chiral aminocyclopropane derivatives is of great interest and importance as these structures are important components of biologically active natural products and pharmaceuticals. We herein report the enantioselective intermolecular hydroamination of substituted cyclopropenes with various amines catalyzed by chiral half‐sandwich rare‐earth‐metal complexes. This method constitutes a 100 % atom‐efficient route for the synthesis of a variety of chiral α‐aminocyclopropane derivatives in high yields (up to 96 %) and excellent stereoselectivity (up to >20:1 d.r. and 99 % ee) under mild reaction conditions (25 °C).
CpPEt2As4—An Organic‐Substituted As4 Butterfly Compound
Authors: Heinl Sebastian , Balázs Gábor , Stauber Andreas , Scheer Manfred
Published: November 2016

CpPEt2As4 (CpPEt=C5(4‐EtC6H4)5) (1) is synthesized by the reaction of CpPEt. radicals with yellow arsenic (As4). In solution an equilibrium of the starting materials and the product is found. However, 1 can be isolated and stored in the solid state without decomposition. As4 can be easily released from 1 under thermal or photochemical conditions. From powder samples of CpPEt2As4, yellow arsenic can be sublimed under rather mild conditions (T=125 °C). A similar behavior for the P4‐releasing agent was determined for the related phosphorus compound CpBIG2P4 (2; CpBIG=C5(4‐nBuC6H4)5). DFT calculations show the importance of dispersion forces for the stability of the products.
A Monoanionic Arsenide Source: Decarbonylation of the 2‐Arsaethynolate Anion upon Reaction with Bulky Stannylenes
Authors: Hinz Alexander , Goicoechea Jose M.
Published: November 2016

We report fundamental studies on the reactivity of the 2‐arsaethynolate anion (AsCO−), a species that has only recently become synthetically accessible. The reaction of AsCO− with the bulky stannylene Ter2Sn (Ter=2,6‐bis[2,4,6‐trimethylphenyl]phenyl) is described, which leads to the unexpected formation of a [Ter3Sn2As2]− cluster compound. On the reaction pathway to this cluster, several intermediates were identified and characterized. After the initial association of AsCO− to Ter2Sn, decarbonylation occurs to give an anion featuring monocoordinate arsenic, [Ter2SnAs]−. Both species are not stable under ambient conditions, and [Ter2SnAs]− rearranges to form [TerSnAsTer]−, an unprecedented anionic mixed Group 14/15 alkene analogue.
An Enantioselective Bidentate Auxiliary Directed Palladium‐Catalyzed Benzylic C−H Arylation of Amines Using a BINOL Phosphate Ligand
Authors: Wang Hao , Tong Hua‐Rong , He Gang , Chen Gong
Published: November 2016

A new enantioselective palladium(II)‐catalyzed benzylic C−H arylation reaction of amines is enabled by the bidentate picolinamide (PA) directing group. This reaction provides the first example of enantioselective benzylic γ‐C−H arylations of alkyl amines, and proceeds with up to 97 % ee. The 2,2′‐dihydroxy‐1,1′‐binaphthyl (BINOL) phosphoric acid ligand, Cs2CO3, and solvent‐free conditions are essential for high enantioselectivity. Mechanistic studies suggest that multiple BINOL ligands are involved in the stereodetermining C−H palladation step.
Ultrashort Beryllium−Beryllium Distances Rivalling Those of Metal−Metal Quintuple Bonds Between Transition Metals
Authors: Yuan Caixia , Zhao Xue‐Feng , Wu Yan‐Bo , Wang Xiaotai
Published: November 2016

Chemical bonding is at the heart of chemistry. Recent work on high bond orders between homonuclear transition metal atoms has led to ultrashort metal−metal (TM−TM) distances defined as dM−M<1.900 Å. The present work is a computational design and characterization of novel main group species containing ultrashort metal−metal distances (1.728–1.866 Å) between two beryllium atoms in different molecular environments, including a rhombic Be2X2 (X=C, N) core, a vertical Be−Be axis in a 3D molecular star, and a horizontal Be−Be axis supported by N‐heterocyclic carbene (NHC) ligands. The ultrashort Be−Be distances are achieved by affixing bridging atoms to attract the beryllium atoms electrostatically or covalently. Among these species are five global minima and one chemically viable diberyllium complex, which provide potential targets for experimental realization.
Surface modification of alumina with biosafe molecules: Nanostructure, thermal, and mechanical properties of PVA nanocomposites
Authors: Mallakpour Shadpour , Sadeghzadeh Rozita
Published: November 2016

In this investigation, citric acid (CA) and ascorbic acid (AA) as biocompatible and biodegradable coupling agents were grafted onto surface of Al2O3 nanoparticles (NP)s via ultrasonic process. Then, various percentages of the modified Al2O3 NP were immobilized onto matrix of pristine poly(vinyl alcohol) (PVA) and ameliorated their morphology, mechanical and thermal properties. Transmission electron microscopy photographs were valid criterion for characterizing morphology of Al2O3 with CA and AA. The improvement of the mechanical properties revealed good dispersion of the modified Al2O3 into the matrix of PVA. Finally, thermogravimetric analysis curves displayed an increase in the thermal stability of the nanocomposites upon grafting of the modified Al2O3. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44561.
Synthesis of a novel phosphorus‐containing dicyclopentadiene novolac hardener and its cured epoxy resin with improved thermal stability and flame retardancy
Authors: Yang Jian‐Wei , Wang Zheng‐Zhou , Liu Lei
Published: November 2016

A novel phosphorus‐containing dicyclopentadiene novolac (DCPD‐DOPO) curing agent for epoxy resins, was prepared from 9,10‐dihydro‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) and n‐butylated dicyclopentadiene phenolic resin (DCPD‐E). The chemical structure of the obtained DCPD‐DOPO was characterized with FTIR, 1H NMR and 31P NMR, and its molecular weight was determined by gel permeation chromatography. The flame retardancy and thermal properties of diglycidyl ether bisphenol A (DGEBA) epoxy resin cured with DCPD‐DOPO or the mixture of DCPD‐DOPO and bisphenol A‐formaldehyde Novolac resin 720 (NPEH720) were studied by limiting oxygen index (LOI), UL 94 vertical test and cone calorimeter (CCT), and differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. It is found that the DCPD‐DOPO cured epoxy resin possess a LOI value of 31.6% and achieves the UL 94 V‐0 rating, while its glass transition temperature (Tg) is a bit lower (133 °C). The Tg of epoxy resin cured by the mixture of DCPD‐DOPO and NPEH720 increases to 137 °C or above, and the UL 94 V‐0 rating can still be maintained although the LOI decreases slightly. The CCT test results demonstrated that the peak heat release rate and total heat release of the epoxy resin cured by the mixture of DCPD‐DOPO and NPEH720 decrease significantly compared with the values of the epoxy resin cured by NPEH720. Moreover, the curing reaction kinetics of the epoxy resin cured by DCPD‐DOPO, NPEH720 or their mixture was studied by DSC. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44599.
Ag@AgCl‐TiO2/organic rectorite/quaternized chitosan microspheres: An efficient and environmental photocatalyst
Authors: Yang Lianli , Ma Xiaoyan , Zhang Weihong , Gen Wei
Published: November 2016

A plasmonic composite, Ag@AgCl‐TiO2/OREC, was prepared by sol–gel combing calcination technique, precipitation, and photoreduction method. Then, Ag@AgCl‐TiO2/OREC/QCS composite microspheres were fabricated by an emulsification/chemical crosslinking method using quaternized chitosan and Ag@AgCl‐TiO2/OREC as scaffolds materials, potassium persulphate as initiator and N,N′‐methylenebisacrylamide as crosslinker. The resulting materials were characterized by Fourier transform infrared spectrometer (FTIR), X‐ray diffraction (XRD), UV‐visible diffused reflectance spectra (UV–vis DRS), and scanning electron microscopy (SEM). SEM showed that the Ag@AgCl‐TiO2/OREC/QCS composite microspheres had loose, rough surface, and spherical shape, with an average diameter of 15–45 μm. The Ag@AgCl‐TiO2/OREC/QCS composite microspheres present good adsorption–photocatalytic activities in the degradation of methylene orange (MO) and 92.1% MO was degraded after irradiation for 180 min. The high photocatalysis activity was attributed to the combined results of the relative high adsorption capacity, loose structure, and the surface plasmon resonance of silver nanoparticles formed on the surface of AgCl. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44601.
Divided Zygomatic Bone in Primates With Implications of Skull Morphology and Biomechanics
Authors: Wang Qian , Dechow Paul C.
Published: November 2016

Typically the zygoma is a single bone in the facial skeleton whose shape uniquely copes with loads associated with mastication. Rarely but naturally, the zygoma is divided into two or more parts by supernumerary sutures. These extra intrazygomatic sutures are located at an area of critical morphological and biomechanical importance, yet their impacts have not been studied. In this study, the morphological and possible biomechanical consequences of the divided zygoma (DZ) were investigated in primates including rhesus macaques (Macaca mulatta), orangutans (Pongo abelii and P. pygmaeus), and modern humans (Homo sapiens). Results demonstrated that a unilateral supernumerary suture within the zygoma affected facial symmetry. The superior division of the divided zygoma was normally slender along with the adjacent frontal bone parts; while the inferior division of the divided zygoma was normally more robust, along with stronger temporal and maxillary bones. These were possible biomechanical consequences, in which the stresses incurred during normal masticatory activities were shunted from the upper face to the lower face, especially along the zygomatic arch. These findings revealed that the DZ condition would alter overall morphology of the midface of the affected side, and unfavorably affect the pattern of stress distribution in the loaded side of the face during mastication. The developmental mechanisms for the supernumerary sutures dividing the zygoma were unclear. Further insights into this rare condition may deepen our understanding of craniofacial form, adaptation, developmental plasticity, and evolution, and help to improve therapeutic philosophies in corrective and regenerative medicine. Anat Rec, 299:1801–1829, 2016. © 2016 Wiley Periodicals, Inc.
The Biomechanics of Zygomatic Arch Shape
Authors: Smith Amanda L. , Grosse Ian R.
Published: November 2016

Mammalian zygomatic arch shape is remarkably variable, ranging from nearly cylindrical to blade‐like in cross section. Based on geometry, the arch can be hypothesized to be a sub‐structural beam whose ability to resist deformation is related to cross sectional shape. We expect zygomatic arches with different cross sectional shapes to vary in the degree to which they resist local bending and torsion due to the contraction of the masseter muscle. A stiffer arch may lead to an increase in the relative proportion of applied muscle load being transmitted through the arch to other cranial regions, resulting in elevated cranial stress (and thus, strain). Here, we examine the mechanics of the zygomatic arch using a series of finite element modeling experiments in which the cross section of the arch of Pan troglodytes has been modified to conform to idealized shapes (cylindrical, elliptical, blade‐like). We find that the shape of the zygomatic arch has local effects on stain that do not conform to beam theory. One exception is that possessing a blade‐like arch leads to elevated strains at the postorbital zygomatic junction and just below the orbits. Furthermore, although modeling the arch as solid cortical bone did not have the effect of elevating strains in other parts of the face, as had been expected, it does have a small effect on stress associated with masseter contraction. These results are counterintuitive. Even though the arch has simple beam‐like geometry, we fail to find a simple mechanical explanation for the diversity of arch shape. Anat Rec, 299:1734–1752, 2016. © 2016 Wiley Periodicals, Inc.
Bacterial Peptide Deformylase Inhibition of Tetrazole‐Substituted Biaryl Acid Analogs: Synthesis, Biological Evaluations, and Molecular Docking Study
Authors: Khan Firoz A. Kalam , Patil Rajendra H. , Patil Manjiri , Arote Rohidas , Shinde Devanand B. , Sangshetti Jaiprakash N.
Published: November 2016

The synthesis and screening of tetrazole‐substituted biaryl acid analogs 7a–l as bacterial peptide deformylase (PDF) enzyme inhibitors is reported. The compounds 7e (IC50 value = 5.50 μM) and 7g (IC50 value = 7.25 μM) showed good PDF inhibition activity. The compounds 7e (MIC range = 10.75–11.66 μg/mL) and 7g (MIC range = 8.91–12.83 μg/mL) also showed potent antibacterial activity when compared with the standard ciprofloxacin (MIC range = 25–50 μg/mL). Thus, the active derivatives were not only potent PDF enzyme inhibitors but also efficient antibacterial agents. In order to gain more insight into the binding mode of the compounds with the PDF enzyme, the most active compounds 7e and 7g, the moderately active compound 7k, and the least active compound 7h were docked against the PDF enzyme of Escherichia coli. The docking study of the most active compounds 7e and 7g against the PDF enzyme exhibited good binding properties. Hence, we believe our synthesized compounds 7a–l could serve as reservoir for bacterial PDF inhibitor development.