bluuebunny/crossref_metadata_2025 huggingface dataset:
Testing constitutive equations for brittle‐ductile deformation associated with faulting in granitic rock
Authors: Nevitt Johanna M. , Warren Jessica M. , Pollard David D.
Published: July 2017

Uncertainty in constitutive equations for brittle‐ductile deformation limits our understanding of earthquake nucleation and propagation at the base of the seismogenic lithosphere. To reduce this uncertainty, we investigate exhumed strike‐slip faults and related deformation features in the Lake Edison granodiorite (central Sierra Nevada, CA) that developed at 250–500°C and ~250 MPa. The Seven Gables outcrop contains a 10 cm wide contractional fault step separating 2 m‐scale left‐lateral faults. Within the step, an ~ 4 cm thick leucocratic dike is stretched and rotated, thus constraining the kinematics of deformation, and the dike and surrounding granodiorite are strongly mylonitized. Petrographic and electron backscatter diffraction analyses reveal evidence for brittle and plastic deformation mechanisms, including dislocation creep, diffusion creep, microfracturing, and cataclasis. We present a 2‐D finite element model of the Seven Gables outcrop that tests a series of candidate constitutive equations: Von Mises elastoplasticity, Drucker‐Prager elastoplasticity, power law creep viscoelasticity, two‐layer elastoviscoplasticity, and coupled elastoviscoplasticity. Models based on Von Mises yielding most accurately match the outcrop deformation. Frictional plastic yield criteria (i.e., Drucker‐Prager) are incapable of reproducing the outcrop deformation due to the elevated mean compressive stress and reduced plastic yielding within the model fault step. Furthermore, the power law creep viscoelastic model requires a high strain rate (~10−4 s−1) to resolve slip on faults and fails to localize strain within the step region. Comparing model results and elastic stress fields with field observations suggests that deformation localizes in regions of elevated mean compressive stress and Mises equivalent stress.
Highly variable aerodynamic roughness length (z0) for a hummocky debris‐covered glacier
Authors: Miles Evan S. , Steiner Jakob F. , Brun Fanny
Published: July 2017

The aerodynamic roughness length (z0) is an essential parameter in surface energy balance studies, but few literature values exist for debris‐covered glaciers. We use microtopographic and aerodynamic methods to assess the spatial variability of z0 for Lirung Glacier, Nepal. We apply structure from motion to produce digital elevation models for three nested domains: five 1 m2 plots, a 21,300 m2 surface depression, and the lower 550,000 m2 of the debris‐mantled tongue. Wind and temperature sensor towers were installed in the vicinity of the plots within the surface depression in October 2014. We calculate z0 according to a variety of transect‐based microtopographic parameterizations for each plot, then develop a grid version of the algorithms by aggregating data from all transects. This grid approach is applied to the surface depression digital elevation model to characterize z0 spatial variability. The algorithms reproduce the same variability among transects and plots, but z0 estimates vary by an order of magnitude between algorithms. Across the study depression, results from different algorithms are strongly correlated. Using Monin‐Obukov similarity theory, we derive z0 values from the meteorological data. Using different stability criteria, we derive median values of z0 between 0.03 m and 0.05 m, but with considerable uncertainty due to the glacier's complex topography. Considering estimates from these algorithms, results suggest that z0 varies across Lirung Glacier between ∼0.005 m (gravels) to ∼0.5 m (boulders). Future efforts should assess the importance of such variable z0 values in a distributed energy balance model.
Fabrication of Nanoporous Alumina Ultrafiltration Membrane with Tunable Pore Size Using Block Copolymer Templates
Authors: Zhou Chun , Segal‐Peretz Tamar , Oruc Muhammed Enes , Suh Hyo Seon , Wu Guangpeng , Nealey Paul F.
Published: July 2017

Control over nanopore size and 3D structure is necessary to advance membrane performance in ubiquitous separation devices. Here, inorganic nanoporous membranes are fabricated by combining the assembly of cylinder‐forming poly(styrene‐block‐methyl methacrylate) (PS‐b‐PMMA) block copolymer and sequential infiltration synthesis (SIS). A key advance relates to the use of PMMA majority block copolymer films and the optimization of thermal annealing temperature and substrate chemistry to achieve through‐film vertical PS cylinders. The resulting morphology allows for direct fabrication of nanoporous AlOx by selective growth of Al2O3 in the PMMA matrix during the SIS process, followed by polymer removal using oxygen plasma. Control over the pore diameter is achieved by varying the number of Al2O3 growth cycles, leading to pore size reduction from 21 to 16 nm. 3D characterization, using scanning transmission electron microscopy tomography, reveals that the AlOx channels are continuous through the film and have a gradual increase in pore size with depth. Finally, the ultrafiltration performance of the fabricated AlOx membrane for protein separation as a function of protein size and charge is demonstrated.
Taming Charge Transport in Semiconducting Polymers with Branched Alkyl Side Chains
Authors: Schroeder Bob C. , Kurosawa Tadanori , Fu Tianren , Chiu Yu‐Cheng , Mun Jaewan , Wang Ging‐Ji Nathan , Gu Xiaodan , Shaw Leo , Kneller James W. E. , Kreouzis Theo , Toney Michael F. , Bao Zhenan
Published: July 2017

The solid‐state packing and polymer orientation relative to the substrate are key properties to control in order to achieve high charge carrier mobilities in organic field effect transistors (OFET). Intuitively, shorter side chains are expected to yield higher charge carrier mobilities because of a denser solid state packing motif and a higher ratio of charge transport moieties. However our findings suggest that the polymer chain orientation plays a crucial role in high‐performing diketopyrrolopyrrole‐based polymers. By synthesizing a series of DPP‐based polymers with different branched alkyl side chain lengths, it is shown that the polymer orientation depends on the branched alkyl chain lengths and that the highest carrier mobilities are obtained only if the polymer adopts a mixed face‐on/edge‐on orientation, which allows the formation of 3D carrier channels in an otherwise edge‐on‐oriented polymer chain network. Time‐of‐flight measurements performed on the various polymer films support this hypothesis by showing higher out‐of‐plane carrier mobilities for the partially face‐on‐oriented polymers. Additionally, a favorable morphology is mimicked by blending a face‐on polymer into an exclusively edge‐on oriented polymer, resulting in higher charge carrier mobilities and opening up a new avenue for the fabrication of high performing OFET devices.
Stabilization of Black Phosphorous Quantum Dots in PMMA Nanofiber Film and Broadband Nonlinear Optics and Ultrafast Photonics Application
Authors: Xu Yanhua , Wang Wenxi , Ge Yanqi , Guo Hanyu , Zhang Xiaojian , Chen Si , Deng Yonghong , Lu Zhouguang , Zhang Han
Published: July 2017

The stabilization of black phosphorous quantum dots (BPQDs) for optical application under ambient conditions is highly challenging. Here, a facile approach is presented to substantially stabilize BPQDs by making a uniform BPQDs/polymethyl methacrylate (PMMA) composite nanofiber film via an electrospinning technique. As verified by femtosecond laser Z‐scan measurement, the BPQDs/PMMA composite nanofiber film that has been stored for three months exhibits almost the same nonlinear optical properties as the fresh BPQDs. Additionally, the BPQDs/PMMA composite nanofiber film demonstrates broadband nonlinear optical response ranging from the visible bandwidth (400 nm) to the mid‐IR bandwidth (at least 1930 nm). By employing the BPQDs/PMMA composite nanofiber film as an optical saturable absorber, an ultrashort pulse with the pulse duration of ≈1.07 ps centered at the wavelength of 1567.6 nm is generated in a mode‐locked fiber laser. These results suggest that the BPQDs/PMMA composite nanofiber film can combine the advantage of convenient integration and mitigation of the drawback of the easy oxidation of black phosphorous and pave the way for BP‐based practical optoelectronic devices.
Spatially Separated CdS Shells Exposed with Reduction Surfaces for Enhancing Photocatalytic Hydrogen Evolution
Authors: Xing Mingyang , Qiu Bocheng , Du Mengmeng , Zhu Qiaohong , Wang Lingzhi , Zhang Jinlong
Published: July 2017

To the photocatalytic H2 evolution, the exposure of a reduction surface over a catalyst plays an important role for the reduction of hydrogen protons. Here, this study demonstrates the design of a noble‐metal‐free spatially separated photocatalytic system exposed with reduction surfaces (MnOx@CdS/CoP) for highly solar‐light‐driven H2 evolution activity. CoP and MnOx nanoparticles are employed as the electron and hole collectors, which are selectively anchored on the outer and inner surface of CdS shells, respectively. Under solar light irradiation, the photogenerated holes and electrons can directionally move to the MnOx and CoP, respectively, leading to the exposure of a reduction surface. As a result, the H2 evolution increases from 32.0 to 238.4 µmol h−1, which is even higher than the activity of platinum‐loaded photocatalyst (MnOx@CdS/Pt). Compared to the pure CdS with serious photocorrosion, the MnOx@CdS/CoP maintains a changeless activity for the H2 evolution and rhodamine B degradation, even after four cycles. The research provides a new strategy for the preparation of spatially separated photocatalysts with a selective reduction surface.
Monodispersed Bioactive Glass Nanoclusters with Ultralarge Pores and Intrinsic Exceptionally High miRNA Loading for Efficiently Enhancing Bone Regeneration
Authors: Xue Yumeng , Guo Yi , Yu Meng , Wang Min , Ma Peter X. , Lei Bo
Published: July 2017

Bioactive glass nanoparticles (BGNs) have attracted much attention in drug delivery and bone tissue regeneration, due to the advantages including biodegradation, high bone‐bonding bioactivity, and facile large‐scale fabrication. However, the wide biomedical applications of BGNs such as efficient gene delivery are limited due to their poor pore structure and easy aggregation. Herein, for the first time, this study reports novel monodispersed bioactive glass nanoclusters (BGNCs) with ultralarge mesopores (10–30 nm) and excellent miRNA delivery for accelerating critical‐sized bone regeneration. BGNCs with different size (100–500 nm) are fabricated by using a branched polyethylenimine as the structure director and catalyst. BGNCs show an excellent apatite‐forming ability and high biocompatibility. Importantly, BGNCs demonstrate an almost 19 times higher miRNA loading than those of conventional BGNs. Additionally, BGNCs–miRNA nanocomplexes exhibit a significantly high antienzymolysis, enhance cellular uptake and miRNA transfection efficiency, overpassing BGNs and commercial Lipofectamine 3000. BGNCs‐mediated miRNA delivery significantly improves the osteogenic differentiation of bone marrow stromal stem cells in vitro and efficiently enhances bone formation in vivo. BGNCs can be a highly efficient nonviral vector for various gene therapy applications. The study may provide a novel strategy to develop highly gene‐activated bioactive nanomaterials for simultaneous tissue regeneration and disease therapy.
Laser‐Induced Graphene Formation on Wood
Authors: Ye Ruquan , Chyan Yieu , Zhang Jibo , Li Yilun , Han Xiao , Kittrell Carter , Tour James M.
Published: July 2017

Wood as a renewable naturally occurring resource has been the focus of much research and commercial interests in applications ranging from building construction to chemicals production. Here, a facile approach is reported to transform wood into hierarchical porous graphene using CO2 laser scribing. Studies reveal that the crosslinked lignocellulose structure inherent in wood with higher lignin content is more favorable for the generation of high‐quality graphene than wood with lower lignin content. Because of its high electrical conductivity (≈10 Ω per square), graphene patterned on wood surfaces can be readily fabricated into various high‐performance devices, such as hydrogen evolution and oxygen evolution electrodes for overall water splitting with high reaction rates at low overpotentials, and supercapacitors for energy storage with high capacitance. The versatility of this technique in formation of multifunctional wood hybrids can inspire both research and industrial interest in the development of wood‐derived graphene materials and their nanodevices.
Multicellular Vascularized Engineered Tissues through User‐Programmable Biomaterial Photodegradation
Authors: Arakawa Christopher K. , Badeau Barry A. , Zheng Ying , DeForest Cole A.
Published: July 2017

A photodegradable material‐based approach to generate endothelialized 3D vascular networks within cell‐laden hydrogel biomaterials is introduced. Exploiting multiphoton lithography, microchannel networks spanning nearly all size scales of native human vasculature are readily generated with unprecedented user‐defined 4D control. Intraluminal channel architectures of synthetic vessels are fully customizable, providing new opportunities for next‐generation microfluidics and directed cell function.
Modeling and optimization of electrospinning of polyvinyl alcohol (PVA)
Authors: Elkasaby Mohamed , Hegab Hussien A. , Mohany Atef , Rizvi Ghaus M.
Published: July 2017

The electrospun fibers can have applications in diverse fields, such as tissue scaffolds, optical electronics, nanocatalysis, and sound absorption. Nanoscale fibers with a higher surface area can provide superior mechanical, physical, and thermal properties. Therefore, investigation of the factors affecting the electrospinning process, for various materials, is required. In this study, the design of experiments issued for optimization of electrospinning of polyvinyl alcohol (PVA). Analysis of variance (ANOVA) and the Taguchi orthogonal array L27OA are employed to analyze the influence of process control parameters. The variables studied are the applied voltages, solution concentrations, rotational speeds, collecting distances, and flow rates. A mathematical model of the polymer fiber diameter as a function of significant process parameters has been built using response surface methodology (RSM). The concentration percentage and the flow rate were determined to be the most significant process variables at 99% and 90% confidence levels, respectively. The predictive model provides 84.34% average model accuracy, which is considered acceptable as this study deals only with 27 of 243 trials needed for a full study based on principles of design of experiments. An additional ANOVA test and corresponding mathematical model have been developed to obtain the interaction effects for processing parameters.
Hierarchical Porous Carbonized Co3O4 Inverse Opals via Combined Block Copolymer and Colloid Templating as Bifunctional Electrocatalysts in Li–O2 Battery
Authors: Cho Seol A. , Jang Yu Jin , Lim Hee‐Dae , Lee Ji‐Eun , Jang Yoon Hee , Nguyen Trang‐Thi Hong , Mota Filipe Marques , Fenning David P. , Kang Kisuk , Shao‐Horn Yang , Kim Dong Ha
Published: July 2017

Hierarchically organized porous carbonized‐Co3O4 inverse opal nanostructures (C‐Co3O4 IO) are synthesized via complementary colloid and block copolymer self‐assembly, where the triblock copolymer Pluronic P123 acts as the template and the carbon source. These highly ordered porous inverse opal nanostructures with high surface area display synergistic properties of high energy density and promising bifunctional electrocatalytic activity toward both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). It is found that the as‐made C‐Co3O4 IO/Ketjen Black (KB) composite exhibits remarkably enhanced electrochemical performance, such as increased specific capacity (increase from 3591 to 6959 mA h g−1), lower charge overpotential (by 284.4 mV), lower discharge overpotential (by 19.0 mV), and enhanced cyclability (about nine times higher than KB in charge cyclability) in Li–O2 battery. An overall agreement is found with both C‐Co3O4 IO/KB and Co3O4 IO/KB in ORR and OER half‐cell tests using a rotating disk electrode. This enhanced catalytic performance is attributed to the porous structure with highly dispersed carbon moiety intact with the host Co3O4 catalyst.
Fetal hemoglobin in sickle cell anemia: The Arab‐Indian haplotype and new therapeutic agents
Authors: Habara Alawi H. , Shaikho Elmutaz M. , Steinberg Martin H.
Published: July 2017

Fetal hemoglobin (HbF) has well‐known tempering effects on the symptoms of sickle cell disease and its levels vary among patients with different haplotypes of the sickle hemoglobin gene. Compared with sickle cell anemia haplotypes found in patients of African descent, HbF levels in Saudi and Indian patients with the Arab‐Indian (AI) haplotype exceed that in any other haplotype by nearly twofold. Genetic association studies have identified some loci associated with high HbF in the AI haplotype but these observations require functional confirmation. Saudi patients with the Benin haplotype have HbF levels almost twice as high as African patients with this haplotype but this difference is unexplained. Hydroxyurea is still the only FDA approved drug for HbF induction in sickle cell disease. While most patients treated with hydroxyurea have an increase in HbF and some clinical improvement, 10 to 20% of adults show little response to this agent. We review the genetic basis of HbF regulation focusing on sickle cell anemia in Saudi Arabia and discuss new drugs that can induce increased levels of HbF.
Internal diversification of non‐Sub‐Saharan haplogroups in Sahelian populations and the spread of pastoralism beyond the Sahara
Authors: Kulichová Iva , Fernandes Verónica , Deme Alioune , Nováčková Jana , Stenzl Vlastimil , Novelletto Andrea , Pereira Luísa , Černý Viktor
Published: July 2017

Background

Today, African pastoralists are found mainly in the Sahel/Savannah belt spanning 6,000 km from west to east, flanked by the Sahara to the north and tropical rainforests to the south. The most significant group among them are the Fulani who not only keep cattle breeds of possible West Eurasian ancestry, but form themselves a gene pool containing some paternally and maternally‐transmitted West Eurasian haplogroups.

Materials and Methods

We generated complete sequences for 33 mitogenomes belonging to haplogroups H1 and U5 (23 and 10, respectively), and genotyped 16 STRs in 65 Y chromosomes belonging to haplogroup R1b‐V88.

Results

We show that age estimates of the maternal lineage H1cb1, occurring almost exclusively in the Fulani, point to the time when the first cattle herders settled the Sahel/Savannah belt. Similar age estimates were obtained for paternal lineage R1b‐V88, which occurs today in the Fulani but also in other, mostly pastoral populations. Maternal clade U5b1b1b, reported earlier in the Berbers, shows a shallower age, suggesting another possibly independent input into the Sahelian pastoralist gene pool.

Conclusions

Despite the fact that animal domestication originated in the Near East ∼ 10 ka, and that it was from there that animals such as sheep, goats as well as cattle were introduced into Northeast Africa soon thereafter, contemporary cattle keepers in the Sahel/Savannah belt show uniparental genetic affinities that suggest the possibility of an ancient contact with an additional ancestral population of western Mediterranean ancestry.
Fast Adsorption of Soft Hydrogel Microspheres on Solid Surfaces in Aqueous Solution
Authors: Matsui Shusuke , Kureha Takuma , Hiroshige Seina , Shibata Mikihiro , Uchihashi Takayuki , Suzuki Daisuke
Published: July 2017

The real‐time adsorption behavior of polymeric colloidal microspheres onto solid surfaces in aqueous solution was visualized for the first time using high‐speed atomic force microscopy (HS‐AFM) to reveal how the softness of the microspheres affects their dynamic adsorption. Studies that focus on the deformability of microspheres upon dynamic adsorption have not yet been reported, most likely on account of a lack of techniques that appropriately depict the dynamic adsorption and deformation behavior of individual microspheres at the nanoscale in real time. In this study, the deformability of microspheres plays a crucial role on the adsorption kinetics, that is, soft hydrogel microspheres adsorb faster than harder elastomeric or rigid microspheres. These results should provide insight towards development of new colloidal nanomaterials that exhibit effective adsorption on specific sites in aqueous solution.
Photon‐Induced Near‐Field Electron Microscopy of Eukaryotic Cells
Authors: Kaplan Mohammed , Yoo Byung‐Kuk , Tang Jau , Karam Tony E. , Liao Bolin , Majumdar Devdoot , Baltimore David , Jensen Grant J. , Zewail Ahmed H.
Published: July 2017

Photon‐induced near‐field electron microscopy (PINEM) is a technique to produce and then image evanescent electromagnetic fields on the surfaces of nanostructures. Most previous applications of PINEM have imaged surface plasmon‐polariton waves on conducting nanomaterials. Here, the application of PINEM on whole human cancer cells and membrane vesicles isolated from them is reported. We show that photons induce time‐, orientation‐, and polarization‐dependent evanescent fields on the surfaces of A431 cancer cells and isolated membrane vesicles. Furthermore, the addition of a ligand to the major surface receptor on these cells and vesicles (epidermal growth factor receptor, EGFR) reduces the intensity of these fields in both preparations. We propose that in the absence of plasmon waves in biological samples, these evanescent fields reflect the changes in EGFR kinase domain polarization upon ligand binding.
Asymmetric Synthesis of Tertiary Alcohols and Thiols via Nonstabilized Tertiary α‐Oxy‐ and α‐Thio‐Substituted Organolithium Species
Authors: Pulis Alexander P. , Varela Ana , Citti Cinzia , Songara Pradip , Leonori Daniele , Aggarwal Varinder K.
Published: July 2017

Nonstabilized α‐O‐substituted tertiary organolithium species are difficult to generate, and the α‐S‐substituted analogues are configurationally unstable. We now report that they can both be generated easily and trapped with a range of electrophiles with high enantioselectivity, providing ready access to a range of enantioenriched tertiary alcohols and thiols. The configurational stability of the α‐S‐organolithium species was enhanced by using a less coordinating solvent and short reaction times.
Unexpected Chiro‐Thermoresponsive Behavior of Helical Poly(phenylacetylene)s Bearing Elastin‐Based Side Chains
Authors: Arias Sandra , Freire Felix , Calderón Marcelo , Bergueiro Julian
Published: July 2017

The thermoresponsive behavior of an elastin‐based polymer can be altered by the polymeric macromolecular conformation. Thus, when the elastin basic amino acid sequence VPGVG is used as a pendant group of a poly(phenylacetylene) (PPA) its thermoresponsive behavior in water can be remotely detected through conformational changes on the formed helix. Circular dichroism at different temperatures shows an inversion of the first Cotton effect (450 nm) at 25.8 °C that matches with the cloud point temperature. The elastin‐based side‐chain poly(phenylacetylene) shows an upper critical solution temperature with low pH and concentration dependency, not expected in elastin‐based polymers. It was found that the polymer self‐assembles in water into spherical nanoparticles with hydrodynamic diameters of 140 nm at the hydrophobic state.
Sustainable plasticizer for butyl rubber cured by phenolic resin
Authors: Li Jiaxi , Isayev Avraam I. , Wang Qianhe , Soucek Mark D.
Published: July 2017

Butyl rubber (also known as isobutylene isoprene rubber, IIR) containing plasticizers and cured by phenolic resin is widely used to manufacture rubber products exposed to high temperature environments. Therefore, carbon black (CB)‐filled IIR containing a petroleum‐based plasticizer [naphthenic oil (NO)] and environmentally friendly bio‐based plasticizers [soybean oil (SO) and norbornylized soybean oil (NSO)] cured by the brominated phenolic resin were studied. The NSO was prepared through the reaction of SO and dicyclopentadiene at different ratios. Gel fraction, crosslink density, curing behavior, thermal, mechanical, and aging properties of the CB‐filled IIR containing different oils were investigated. The addition of SO and NSO increased the thermal stability and decreased the crosslink density of the IIR vulcanizates compared to that of the IIR/NO vulcanizate. This was found to be due to the reaction between the phenolic resin and the bio‐based oils. Reducing the oil level increased the crosslink density of the IIR/SO and IIR/NSO vulcanizates, which in turn increased the modulus and tensile strength. Among various vulcanizates, the IIR/NSO vulcanizates showed the best overall hot air aging resistance. Results showed that NSO in the amount less than 10 phr could be a good replacement for the petroleum‐based plasticizer in IIR cured by phenolic resins. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45500.
Lignin‐based carbon fibers: Accelerated stabilization of lignin fibers in the presence of hydrogen chloride
Authors: Yue Zhongren , Vakili Ahmad , Hosseinaei Omid , Harper David Paul
Published: July 2017

Organosolv switchgrass lignin (SGL) and hardwood lignin (HWL) polymers are used as precursors to prepare low cost carbon fibers (CFs). Lignin powder and fiber samples are stabilized and carbonized at different conditions to investigate the effect of HCl on thermal‐oxidative stabilization time, mass yield, fiber diameter, and mechanical properties. The results show that HCl can accelerate stabilization and reduce the stabilization time from many hours to 75 min for the SGL fibers, and to 35 min for the HWL fiber. The rate of rapid stabilization in HCl/air is at least four times faster than conventional stabilization in air. The CFs prepared with two different stabilization methods have almost the same strength and modulus, but higher carbon yield is obtained with the rapid stabilization due to a short time of oxidation. Pores and defects observed on the surface and the cross‐section of the CFs across all stabilization conditions contribute to low fiber strength. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45507.
Inverted Organic Solar Cells Fabricated with Room‐Temperature‐deposited Transparent Multilayer Electrodes
Authors: Kim Jun Ho , Kwon Sung‐Nam , Na Seok‐In , Yoo Young‐Zo , Seong Tae‐Yeon
Published: July 2017

We investigated the electrical, optical, and structural properties of Al‐dopedZnO(AZO)/Ag/AZOand indium gallium zinc oxide (IGZO)/Ag/IGZOmultilayer films, and the performance of inverted organic solar cells (OSCs) fabricated with Sn‐doped indium oxide (ITO),AZO/Ag/AZO, andIGZO/Ag/IGZOelectrodes. Even though deposited at room temperature,AZO/Ag/AZO(36 nm/19 nm/36 nm) andIGZO/Ag/IGZO(39 nm/19 nm/39 nm) multilayer films showed sheet resistances of 4.1 and 4.2 Ω/sq, resistivities of 3.3 × 10−5and 4.1 × 10−5Ω cm, and transmittances of 93 and 88% at 550 nm, respectively. Figures of merit (FOMs) were obtained to be 99.9 and 49.9 × 10−3Ω−1for theAZO/Ag/AZOandIGZO/Ag/IGZOfilms, respectively. InvertedOSCsfabricated using the as‐depositedAZO/Ag/AZOandIGZO/Ag/IGZOelectrodes produced power conversion efficiencies (PCEs) of 2.4 and 2.6%, respectively, while that with high‐temperature annealedITOelectrode gave aPCEof 3.2%.
Inverse Power Law for Complete Basis Limit of CCSD(T) Theory for OH Vibrational Potential Energies of Water Molecules
Authors: Jeon Kiyoung , Yang Mino
Published: July 2017

Quantum chemical electronic energy of a molecular system depends on the level of the employed basis functions. The inverse power laws describing the convergences of the calculated Hartree–Fock (HF) and electronic correlation energies of water molecules have been determined by fitting the energies predicted by the CCSD(T) theory with various levels of correlation consistent basis functions. The law was applied to calculate the energies of a few simple water clusters by varying the OH bond distance of a molecule in order to understand how the two parts of the potential energy subject to the stretching motion of water molecules depend on the variation of local environments. It is found that the HF energy strongly depends on the environments of a local OH bond while the correlation energy is almost insensitive to the neighboring molecules. This suggests that the HF theory may have a great advantage in saving computation time for efficient calculations of vibrational frequencies widely distributed due to the inhomogeneity in the local environments of water molecules in the condensed phases.
Bioactive Pimarane‐Type Diterpenes from Marine Organisms
Authors: Wang Xiaoli , Yu Haobing , Zhang Yixin , Lu Xiaoling , Wang Bin , Liu Xiaoyu
Published: July 2017

Marine organisms represent an abundant sources of bioactive natural products with unique chemical structure. Pimarane diterpenes are a structurally diverse family of natural products with various biological activities and pharmacological properties. A prolific source of new marine‐derived pimarane diterpenes have attracted considerable interest because of their unique structural diversity and varied biological activities, including antimicrobial, antitumor, and antiproliferative activities. This review provides a comprehensive overview of the structures, names, bioactivities, and references of 80 marine‐derived pimarane‐type natural products for the first time.
A Continuous Process for the Purification of Terpenyl Amines Using a Reversible Acid‐Base Reaction
Authors: Färber Tobias , Behr Arno , Fink Natalia , Koop Jörg
Published: July 2017

The reversible reactive extraction of long‐chain terpenyl amines (TPAs) using organic acids as reactive extractants was investigated. The scope of suitable acids has been extended and semicontinuous and continuous experiments were performed to prove the applicability of this concept. High extraction yields could be achieved using a variety of acids in batch and semicontinuous experiments. Furthermore, the recovery and separation of the extracted TPAs from the extractant phase has been studied. The TPAs can be recovered in high yields and purities by simple means of process parameter changes. The proposed process allows the separation and purification of TPAs in high yields and purities without the creation of salts or other chemical by‐products.
Thermally Activated Delayed Fluorescence in CuI Complexes Originating from Restricted Molecular Vibrations
Authors: Li Guangfu , Nobuyasu Roberto S. , Zhang Baohua , Geng Yun , Yao Bing , Xie Zhiyuan , Zhu Dongxia , Shan Guogang , Che Weilong , Yan Likai , Su Zhongmin , Dias Fernando B. , Bryce Martin R.
Published: July 2017

The mechanism of thermally activated delayed fluorescence (TADF) in molecules in aggregated or condensed solid states has been rarely studied and is not well understood. Nevertheless, many applications of TADF emitters are strongly affected by their luminescence properties in the aggregated state. In this study, two new isomeric tetradentate CuI complexes which simultaneously show aggregation induced emission (AIE) and TADF characteristics are reported for the first time. We provide direct evidence that effectively restricting the vibrations of individual molecules is a key requisite for TADF in these two CuI complexes through in‐depth photophysical measurements combined with kinetic methods, single crystal analysis and theoretical calculations. These findings should stimulate new molecular engineering endeavours in the design of AIE–TADF active materials with highly emissive aggregated states.
Component‐Customizable Porous Rare‐Earth‐Based Colloidal Spheres towards Highly Effective Catalysts and Bioimaging Applications
Authors: Li Cheng Chao , Rui Xianhong , Wei Weifeng , Chen Libao , Yu Yan
Published: July 2017

Multicomponent porous colloidal spheres are of interest because they not only show a combination of the properties associated with all different components, but also usually present synergy effects. However, a combination of different components in a single porous sphere is still greatly challenged due to the different precipitation behaviors of each component. In this work, we have developed a general synthetic route to prepare several categories of porous monodisperse rare‐earth (RE)‐based colloidal spheres with customizable elemental compositions and a uniform element distribution. The two‐step synthetic strategy is based on the integration of coordination chemistry precipitation of RE ions and a subsequent ion‐exchange process, which steers clear of obstacles, such as differences in solubility product constant, that are to be found in traditional co‐precipitation methods. Our approach provides a new mixing mechanism to realize homogeneous distribution of each element within the porous spheres. An array of binary, ternary, and even senary RE colloidal porous spheres with diameters of 500 nm to 700 nm has been successfully synthesized. Taking advantage of their good dispersibility, porosity, and customizable components, these porous RE oxide spheres show excellent catalytic activity for the reduction of 4‐nitrophenol, and promising application in single‐phase multifunctional bioprobes.
Crystallization Caught in the Act with Terahertz Spectroscopy: Non‐Classical Pathway for l‐(+)‐Tartaric Acid
Authors: Soltani Amin , Gebauer Denis , Duschek Lennart , Fischer Bernd M. , Cölfen Helmut , Koch Martin
Published: July 2017

Crystal formation is a highly debated problem. This report shows that the crystallization of l‐(+)‐tartaric acid from water follows a non‐classical path involving intermediate hydrated states. Analytical ultracentrifugation indicates solution clusters of the initial stages aggregate to form an early intermediate. Terahertz spectroscopy performed during water evaporation highlights a transient increase in the absorption during nucleation; this indicates the recurrence of water molecules that are expelled from the intermediate phase. Besides, a transient resonance at 750 GHz, which can be assigned to a natural vibration of large hydrated aggregates, vanishes after the final crystal has formed. Furthermore, THz data reveal the vibration of nanosized clusters in the dilute solution indicated by analytical ultracentrifugation. Infrared spectroscopy and wide‐angle X‐ray scattering highlight that the intermediate is not a crystalline hydrate. These results demonstrate that nanoscopic intermediate units assemble to form the first solvent‐free crystalline nuclei upon dehydration.
Synthesis of Benzofurans and Indoles from Terminal Alkynes and Iodoaromatics Catalyzed by Recyclable Palladium Nanoparticles Immobilized on Siliceous Mesocellular Foam
Authors: Bruneau Alexandre , Gustafson Karl P. J. , Yuan Ning , Tai Cheuk‐Wai , Persson Ingmar , Zou Xiaodong , Bäckvall Jan‐E.
Published: July 2017

Herein, we report on the utilization of a heterogeneous catalyst, consisting of Pd nanoparticles supported on a siliceous mesocellular foam (Pd0‐AmP‐MCF), for the synthesis of heterocycles. Reaction of o‐iodophenols and protected o‐iodoanilines with acetylenes in the presence of a Pd nanocatalyst produced 2‐substituted benzofurans and indoles, respectively. In general, the catalytic protocol afforded the desired products in good to excellent yields under mild reaction conditions without the addition of ligands. Moreover, the structure of the reported Pd nanocatalyst was further elucidated with extended X‐ray absorption fine‐structure spectroscopy, and it was proven that the catalyst could be recycled multiple times without significant loss of activity.
Divergent Regio‐ and Stereoselective Gold‐catalyzed Synthesis of α‐Fluorosulfones and β‐Fluorovinylsulfones from Alkynylsulfones
Authors: Zeng Xiaojun , Liu Shiwen , Hammond Gerald B. , Xu Bo
Published: July 2017

We developed a widely applicable, highly efficient synthesis of α‐fluorosulfone and β‐fluorovinylsulfone catalyzed by gold. Starting with alkynyl sulfone 1, an [Au]/HF/N‐oxide system gives α‐fluorosulfone 3 via a gold carbene intermediate, and, if no N‐oxide is used, direct addition of HF to 1 gives vinyl sulfone 4 via a vinylfluoro gold intermediate. Both methods have good functional group tolerance and the reactions can be conducted in ambient atmosphere.
Testing perfect rankings in ranked‐set sampling with binary data
Authors: Frey Jesse , Zhang Yimin
Published: July 2017

In ranked‐set sampling, the rankings may be either perfect or imperfect. Statistical procedures that assume perfect rankings tend to be more efficient than procedures that do not assume perfect rankings when perfect rankings actually hold, but may perform poorly if the rankings are imperfect. Several procedures have been developed for testing the null hypothesis of perfect rankings, but these procedures break down if the data are not continuous. In this article, we develop tests of perfect rankings that can be applied with binary data. Motivated by new theoretical results about how the success probabilities in the judgment strata differ under perfect and imperfect rankings, we develop a consistent test with a test statistic that is asymptotically normal. We find, however, that the test does not properly control the type I error rate with small samples. This motivates us to instead implement a bootstrap version of the test. This bootstrap test controls the type I error rate even with small sample sizes. Functions for implementing both tests using R are available in the Supplementary Material. The Canadian Journal of Statistics 45: 326–339; 2017 © 2017 Statistical Society of Canada
Transforming the empirical likelihood towards better accuracy
Authors: Jing Bing‐Yi , Tsao Min , Zhou Wang
Published: July 2017

Under‐coverage has been a long‐standing issue with the empirical likelihood confidence region. Several methods can be used to address this issue, but they all add complexity to the empirical likelihood inference requiring extra computation and/or extra theoretical investigation. The objective of this article is to find a method that does not add complexity. To this end we look for a simple transformation of the empirical likelihood to alleviate the under‐coverage. Using several criteria concerning the accuracy, consistency, and preservation of the geometric appeal of the original empirical likelihood we obtain a transformed version of the empirical likelihood that is extremely simple in theory and computation. Its confidence regions are surprisingly accurate, even in small sample and multidimensional situations. It can be easily used to alleviate the under‐coverage problem of empirical likelihood confidence regions. The Canadian Journal of Statistics 45: 340–352; 2017 © 2017 Statistical Society of Canada
Fluorescent Metal–Organic Frameworks for Selective Sensing of Toxic Cations (Tl3+, Hg2+) and Highly Oxidizing Anions ((CrO4)2−, (Cr2O7)2−, (MnO4)−)
Authors: Jana Ajay Kumar , Natarajan Srinivasan
Published: July 2017

The ligand 4,4′‐(benzothiadiazole‐4,7‐diyl)dibenzoic acid was synthesized and employed for the synthesis of two metal–organic framework (MOF) compounds, [Mn4(C20H10N2O4S)2(HCOO)4(DEF)2] (I; DEF=N,N′‐diethylformamide) and [Pb(C20H10N2O4S)(DMF)] (II; DMF=N,N′‐dimethylformamide). Single‐crystal structure studies revealed that compound I has a three‐dimensional structure and compound II has a two‐dimensional structure. The luminescent nature of the MOFs was gainfully employed as a probe for the detection of highly toxic metal ions such as Tl3+ and Hg2+. The detection limits were found to be in the parts per billion (ppb) level. The presence of an unsubstituted thiadiazole ring in the ligand appears to help in the detection of these highly toxic metal ions in solution as the metal ions interact with S, which was revealed by Raman spectroscopic studies. The compounds were also found to be good candidates for the detection of highly oxidizing anions such as chromate, dichromate, and permanganate, again in ppb levels of concentration in solution. Magnetic studies on compound I indicate antiferromagnetic behavior. The variable‐temperature electrical conductivity studies indicate a semiconducting nature with comparable behavior to well‐known semiconductors such as CdSe, ZnTe, and GaP.
Genetic Variants in HSD17B3, SMAD3, and IPO11 Impact Circulating Lipids in Response to Fenofibrate in Individuals With Type 2 Diabetes
Authors: Rotroff Daniel M. , Pijut Sonja S. , Marvel Skylar W. , Jack John R. , Havener Tammy M. , Pujol Aurora , Schluter Agatha , Graf Gregory A. , Ginsberg Henry N. , Shah Hetal S. , Gao He , Morieri Mario‐Luca , Doria Alessandro , Mychaleckyi Josyf C. , McLeod Howard L. , Buse John B. , Wagner Michael J. , Motsinger‐Reif Alison A. ,   the ACCORD/ACCORDion Investigators
Published: July 2017

Individuals with type 2 diabetes (T2D) and dyslipidemia are at an increased risk of cardiovascular disease. Fibrates are a class of drugs prescribed to treat dyslipidemia, but variation in response has been observed. To evaluate common and rare genetic variants that impact lipid responses to fenofibrate in statin‐treated patients with T2D, we examined lipid changes in response to fenofibrate therapy using a genomewide association study (GWAS). Associations were followed‐up using gene expression studies in mice. Common variants in SMAD3 and IPO11 were marginally associated with lipid changes in black subjects (P < 5 × 10‐6). Rare variant and gene expression changes were assessed using a false discovery rate approach. AKR7A3 and HSD17B13 were associated with lipid changes in white subjects (q < 0.2). Mice fed fenofibrate displayed reductions in Hsd17b13 gene expression (q < 0.1). Associations of variants in SMAD3, IPO11, and HSD17B13, with gene expression changes in mice indicate that transforming growth factor‐beta (TGF‐β) and NRF2 signaling pathways may influence fenofibrate effects on dyslipidemia in patients with T2D.
Phase I, Randomized, Double‐blind, Placebo‐controlled, Single‐dose, and Multiple‐dose Studies of Erenumab in Healthy Subjects and Patients With Migraine
Authors: de Hoon Jan , Van Hecken Anne , Vandermeulen Corinne , Yan Lucy , Smith Brian , Chen Jiyun Sunny , Bautista Edgar , Hamilton Lisa , Waksman Javier , Vu Thuy , Vargas Gabriel
Published: July 2017

Monoclonal antibodies (mAbs) targeting calcitonin gene‐related peptide (CGRP) signaling are being explored as prophylactic treatments for migraine. Erenumab (AMG 334) is the first potent, selective, and competitive human mAb antagonist of the CGRP receptor. We report the data from two phase I studies assessing the safety, pharmacokinetics (PK), and pharmacodynamics of single and multiple administrations of erenumab in healthy subjects and patients with migraine. The results indicate that the PK profile of erenumab is nonlinear from 1 mg to 70 mg and the linear portion of the clearance from 70 mg to 210 mg is consistent with other human immunoglobulin G2 antibodies. Single doses of erenumab resulted in >75% inhibition of capsaicin‐induced dermal blood flow, with no apparent dose‐dependency for erenumab ≥21 mg. Erenumab was generally well tolerated, with an acceptable safety profile, supporting further clinical development of erenumab for migraine prevention.
One‐Step Formation of 3D Alternating‐Layer Structures Composed of Plates of Nanocrystalline Bismuth Oxide and Spherical Particles of Metallic Bismuth
Authors: Bokhonov Boris B. , Yukhin Yurii M.
Published: July 2017

Three‐dimensional (3D) objects with a periodic structure composed of particles differing in composition and/or morphology have attracted a lot of attention due to their high potential for achieving new sets of properties nonexistent in single‐phase materials and materials lacking a periodic structure. In this work, we have demonstrated a possibility of synthesizing a periodic heterostructure consisting of layers of nanocrystalline β‐bismuth oxide and layers of spherical particles of metallic bismuth in a single step by conducting partial reduction of [Bi6O5(OH)3](NO3)5·3H2O in benzyl alcohol. The synthesis method of micrometer‐sized particles of nanocrystalline β‐Bi2O3/spherical Bi with a 3D periodic structure is proposed in this work for the first time. The mechanisms governing the interface formation during the synthesis of the β‐Bi2O3/spherical Bi alternating‐layer structure are discussed. The structural evolution of [Bi6O5(OH)3](NO3)5·3H2O during its partial reduction in benzyl alcohol shows an example of the strong interrelation between the phase composition, morphology and architecture of the reaction products derived from a single‐phase precursor. The proposed synthesis method of the β‐Bi2O3/spherical Bi alternating‐layer 3D materials is easily scalable, shows good reproducibility and is based on simple experimental procedures.
Impact of Interfacial Layers in Perovskite Solar Cells
Authors: Cho An‐Na , Park Nam‐Gyu
Published: July 2017

Perovskite solar cells (PCSs) are composed of organic–inorganic lead halide perovskite as the light harvester. Since the first report on a long‐term‐durable, 9.7 % efficient, solid‐state perovskite solar cell, organic–inorganic halide perovskites have received considerable attention because of their excellent optoelectronic properties. As a result, a power conversion efficiency (PCE) exceeding 22 % was certified. Controlling the grain size, grain boundary, morphology, and defects of the perovskite layer is important for achieving high efficiency. In addition, interfacial engineering is equally or more important to further improve the PCE through better charge collection and a reduction in charge recombination. In this Review, the type of interfacial layers and their impact on photovoltaic performance are investigated for both the normal and the inverted cell architectures. Four different interfaces of fluorine‐doped tin oxide (FTO)/electron‐transport layer (ETL), ETL/perovskite, perovskite/hole‐transport layer (HTL), and HTL/metal are classified, and their roles are investigated. The effects of interfacial engineering with organic or inorganic materials on photovoltaic performance are described in detail. Grain‐boundary engineering is also included because it is related to interfacial engineering and the grain boundary in the perovskite layer plays an important role in charge conduction, recombination, and chargecarrier life time.
Phytochemical Investigation, Antitumor Activity, and Hepatoprotective Effects of Acrocarpus fraxinifolius Leaf Extract
Authors: El‐Nashar Heba A. S. , Eldahshan Omayma A. , Elshawi Omama E. , Singab Abdel Nasser B.
Published: July 2017

Preclinical Research

Nine known phenolic compounds were isolated from an aqueous methanolic extract of Acrocarpus fraxinifolius Weight and Arn leaves (AFL) family Fabaceae. This extract of AFL contained approximately 169 mg gallic acid/g as assessed by HPLC. The AFL extract had marginal antitumor activity (IC50 > 200 µL/mL) but showed a concentration‐dependent hepatoprotective effect against CCl4‐induced hepatotoxicity in vitro. Cell viability was increased, ALT and AST activity declined and reduced GSH concentration and SOD activity were restored as compared with silymarin. In vivo concurrent administration of AFL extract (500 mg/kg po) showed a hepatoprotective effect against gamma irradiation and CCl4 as evidenced by reduction of TNF‐α, interleukin‐6, malondialdehyde, nitric oxide, DNA fragmentation, caspase‐3 activity, and downregulation of its m‐RNA level and decreased proapoptotic protein Bax expression. AFL extract enhanced glutathione peroxidase, superoxide dismutase, and catalase activities, reduced glutathione concentrations and upregulated the expression of antiapoptotic Bcl‐2. The extract could ameliorate hepatic injuries induced by gamma irradiation and CCl4 in rats suggesting potent hepatoprotective activity. Drug Dev Res 78 : 210–226, 2017. © 2017 Wiley Periodicals, Inc.