bluuebunny/crossref_metadata_2025 huggingface dataset:
Laboratory study of gravel‐bed cluster formation and disintegration
Authors: Heays K. G. , Friedrich H. , Melville B. W.
Published: February 2014

Increased knowledge of clusters is essential for the understanding of sediment transport behavior and the monitoring and protection of aquatic life. A physical study using graded river gravels is conducted in a laboratory environment. Using photogrammetry and painted gravels, a cluster identification tool (CIT) is developed based on image subtraction between subsequent frames, allowing identification of any stable areas and groups of particles on the bed. This is combined with digital particle tracking (DPT) to present a novel approach for monitoring the formation and disintegration of clusters. Clusters from graded gravels are formed successfully during the experimental stage, allowing investigation into the complex dynamic behavior of cluster formation and disintegration in a simulated natural environment. Various anchor stone arrangements are used in the experiments. However, only about one fifth of the potential anchor stones on the bed surface enable cluster formation. In general, clusters classified as “typical” and “heap” are most common. Inspection of temporal cluster coverage of the test‐bed surface shows that the proportion of clusters present on the surface tends to grow with time. Maximum cluster surface coverage of between 5% and 34% is observed. In addition, particles entering and departing from clusters are monitored. Most commonly, particles enter from directly upstream of the cluster, however >20% of particles approach from a direction >20 deg from the streamwise direction. Approximately 35% of all particles directly upstream of a cluster bypass the cluster.
Modeling dependence between extreme rainfall and storm surge to estimate coastal flooding risk
Authors: Zheng Feifei , Westra Seth , Leonard Michael , Sisson Scott A.
Published: February 2014

Accounting for dependence between extreme rainfall and storm surge can be critical for correctly estimating coastal flood risk. Several statistical methods are available for modeling such extremal dependence, but the comparative performance of these methods for quantifying the exceedance probability of rare coastal floods is unknown. This paper compares three classes of statistical methods—threshold‐excess, point process, and conditional—in terms of their ability to quantify flood risk. The threshold‐excess method offers approximately unbiased estimates for dependence parameters, but its application for quantifying flood risk is limited because it is unable to handle situations where only one of the two variables is extreme. In contrast, the point process method (with the logistic and negative logistic models) and the conditional method describe the full distribution of extremes, but they overestimate and underestimate the dependence strength, respectively. We conclude that the point process method is the most suitable approach for modeling dependence between extreme rainfall and storm surge when the dependence is relatively strong, while none of the three methods produces satisfactory results for bivariate extremes with very weak dependence. It is therefore important to take the bias of each method into account when applying them to flood estimation problems. A case study is used to demonstrate the three statistical methods and illustrate the implication of dependence to flood risk.
Coherent structure generated in the boundary layer of a laboratory‐created ionospheric depletion
Authors: Liu Yu , Cao Jinxiang , Xu Liang , Zhang Xiao , Wang Pi , Wang Jian , Du Yinchang , Zheng Zhe
Published: February 2014

Laboratory experiments have been conducted to simulate the boundary processes of ionospheric depletion. The ionospheric depletion was modeled through releasing depletion chemical (SF6) into the ambient plasmas. These plasmas were segregated into two regions by a boundary layer of width electric scale length. In the localized boundary layer, the electron density decreased sharply that yielded steep density gradients. Meanwhile, the floating potential increased in the time scales of the lower hybrid (LH) period, which produced strong sheared electron flows. The shear frequency ωs=VE/LE, which characterizes the sheared flow, is much larger than the LH frequency ωLH. A coherent structure was observed when the floating potential fluctuations were analyzed using digital spectral analysis techniques. Comparison with the theory indicated that the structure is driven by the electron‐ion hybrid instability which is generated owing to the nonlinear coupling between the electron density gradient and the sheared electron flow. Our results are important to study the early phase nonlinear evolution of the ionospheric depletion, especially in the development of plasma irregularities and turbulence in the boundary layer.
The peridotite ridge province in the southern Iberia Abyssal Plain: Seismic constraints revisited
Authors: Minshull T. A. , Dean S. M. , Whitmarsh R. B.
Published: February 2014

The west Iberia margin has become the type example of a magma‐starved margin in which extension during breakup led to the exhumation of mantle rocks apparently over a broad area. Much of our understanding of this process is based on geophysical and drilling data from the southern Iberia Abyssal Plain, where the seaward part of the region of exhumed mantle is composed of a series of margin‐parallel basement ridges. Here we analyze wide‐angle and normal‐incidence seismic data from a series of intersecting profiles across this peridotite ridge province and develop a three‐dimensional picture of its structure. Using these seismic data, we infer a location and age (magnetic anomaly M1; 125–127 Ma) of first‐formed oceanic crust in this region that are consistent with Ocean Drilling Program data and data from the conjugate margin. We infer that the peridotite ridge province is about 70 km wide with strong serpentinization (>75%) at the top of the basement reducing to much lower degrees (< 25%) around 2 km below. We map the geometry of some prominent reflectors on the landward margin of the peridotite ridge province that likely represent detachment faults and show that one of these has a domal structure similar to that of detachment faults at slow to ultraslow spreading mid‐ocean ridges.
Electro‐Drawn Drug‐Loaded Biodegradable Polymer Microneedles as a Viable Route to Hypodermic Injection
Authors: Vecchione Raffaele , Coppola Sara , Esposito Eliana , Casale Costantino , Vespini Veronica , Grilli Simonetta , Ferraro Pietro , Netti Paolo Antonio
Published: February 2014

Hypodermic needle injection is still the most common method of drug delivery despite its numerous limitations and drawbacks, such as pain, one‐shot administration, and risk of infection. Seeking a viable, safe, and pain‐free alternative to the over 16 billion injections per year has therefore become a top priority for our modern technological society. Here, a system that uses a pyroelectric cartridge in lieu of the syringe piston as a potential solution is discussed. Upon stimulation, the cartridge electro‐draws, at room temperature, an array of drug‐encapsulated, biodegradable polymer microneedles, able to deliver into hypodermic tissue both hydrophobic and hydrophilic bioactive agents, according to a predefined chrono‐programme. This mould‐free and contact‐free method permits the fabrication of biodegradable polymer microneedles into a ready‐to‐use configuration. In fact, they are formed on a flexible substrate/holder by drawing them directly from drop reservoirs, using a controlled electro‐hydrodynamic force. Tests of insertion are performed and discussed in order to demonstrate the possibility to prepare microneedles with suitable geometric and mechanical properties using this method.
Rapid Prototyping for Soft‐Matter Electronics
Authors: Lu Tong , Finkenauer Lauren , Wissman James , Majidi Carmel
Published: February 2014

A series of rapid and inexpensive methods to produce elastically soft sensors and circuits in minutes using a CO2 laser (10.6 μm wavelength) are introduced. These soft‐matter electronics are composed of laser‐patterned films of conductive poly(dimethylsiloxane) (cPDMS) and liquid‐phase gallium–indium (GaIn) alloy embedded in a thin sheet of soft silicone elastomer. Direct laser patterning eliminates the need for photolithography, replica molding, and customized inkjet or microcontact (μCP) printing, and allows conductive traces of cPDMS and liquid GaIn to be rapidly integrated into a single soft‐matter circuit. The versatility of this fabrication method is demonstrated by the production of a variety of electrically functional soft‐matter sensors and circuit elements that contain features with >150 μm planar dimensions. It is postulate that in the case of GaIn alloy patterning occurs when the recoil force of the escaping vapor exceeds the liquid's surface tension. This mechanism exploits the unique “moldability” of liquid GaIn alloy, which forms a surface oxide of Ga2O3 that allows the patterned film to maintain its shape.
Theoretical Investigation and Structural Optimization of Single‐Electrode Triboelectric Nanogenerators
Authors: Niu Simiao , Liu Ying , Wang Sihong , Lin Long , Zhou Yu Sheng , Hu Youfan , Wang Zhong Lin
Published: February 2014

Single‐electrode triboelectric nanogenerators (SETENGs) significantly expand the application of triboelectric nanogenerators in various circumstances, such as touch‐pad technologies. In this work, a theoretical model of SETENGs is presented with in‐depth interpretation and analysis of their working principle. Electrostatic shield effect from the primary electrode is the main consideration in the design of such SETENGs. On the basis of this analysis, the impacts of two important structural parameters, that is, the electrode gap distance and the area size, on the output performance are theoretically investigated. An optimized electrode gap distance and an optimized area size are observed to provide a maximum transit output power. Parallel connection of multiple SETENGs with micro‐scale size and relatively larger spacing should be utilized as the scaling‐up strategy. The discussion of the basic working principle and the influence of structural parameters on the whole performance of the device can serve as an important guidance for rational design of the device structure towards the optimum output in specific applications.
Tailoring Microstructure of Graphene‐Based Membrane by Controlled Removal of Trapped Water Inspired by the Phase Diagram
Authors: Lv Wei , Li Zhengjie , Zhou Guangmin , Shao Jiao‐Jing , Kong Debin , Zheng Xiaoyu , Li Baohua , Li Feng , Kang Feiyu , Yang Quan‐Hong
Published: February 2014

As an important form of graphene assembled in macroscale, the graphene‐based membrane attracts much attention due to its easy manipulation and various potential applications. However, tailoring the microstructure of these membranes is hard to achieve and the surface utilization of graphene layers is low. By analyzing the drying process for the wet graphene oxide membrane (GOM), it is found that the trapped water in freshly formed GOM actually provides potential forces to tune its microstructure. According to the phase diagram of pure water, with a reduced pressure, the trapped water boils seriously and then transforms into ice crystal instantaneously around the triple point. This sudden phase change across the triple point provides strong forces to change and fix the microstructure of GOM. In this study, the ordinary evaporation drying process for the wet GOM is replaced with a two‐stage drying process and the tightly layered structure of graphene membrane is turned into an open and grade structure. The obtained membrane shows high surface utilization. Thus, after reduction, the membrane possesses high adsorption capability towards various molecules, especially for heavy oil and lithium polysulfide products in the cathode of Li–S battery. Furthermore, the membrane shows high rate performance as the electrodes for supercapacitors.
Flexible and Transparent Nanocomposite of Reduced Graphene Oxide and P(VDF‐TrFE) Copolymer for High Thermal Responsivity in a Field‐Effect Transistor
Authors: Trung Tran Quang , Ramasundaram Subramanian , Hong Seok Won , Lee Nae‐Eung
Published: February 2014

A new class of temperature‐sensing materials is demonstrated along with their integration into transparent and flexible field‐effect transistor (FET) temperature sensors with high thermal responsivity, stability, and reproducibility. The novelty of this particular type of temperature sensor is the incorporation of an R‐GO/P(VDF‐TrFE) nanocomposite channel as a sensing layer that is highly responsive to temperature, and is optically transparent and mechanically flexible. Furthermore, the nanocomposite sensing layer is easily coated onto flexible substrates for the fabrication of transparent and flexible FETs using a simple spin‐coating method. The transparent and flexible nanocomposite FETs are capable of detecting an extremely small temperature change as small as 0.1 °C and are highly responsive to human body temperature. Temperature responsivity and optical transmittance of transparent nanocomposite FETs were adjustable and tuneable by changing the thickness and R‐GO concentration of the nanocomposite.
Fabrication of Barium‐ and Strontium‐Doped Silica/Titania Hollow Nanoparticles and Their Synergetic Effects on Promoting Neuronal Differentiation by Activating ERK and p38 Pathways
Authors: Kim Sojin , Jang Yoonsun , Oh Wan‐Kyu , Kim Chanhoi , Jang Jyongsik
Published: February 2014

Pristine, barium‐doped, and strontium‐doped hollow nanoparticles (p‐HNPs, Ba‐HNP, and Sr‐HNP; HNPs) are prepared by sonication‐mediated etching and redeposition (SMER) method and alkali‐earth‐metal hydroxide solution treatment. The HNPs are investigated to facilitate synergetic neuronal differentiation through alkali‐earth‐metal doping and in conjunction with nerve growth factor (NGF). PC12 cells are used as model cells for neuronal differentiation. The differentiation efficiency is improved in the presence of the HNPs+NGF, and the neurite length is in the order of Sr‐HNP+NGF > Ba‐HNP+NGF > p‐HNP+NGF > NGF. Silica/titania have increasing effect on both differentiation efficiency and neurite length, and doped barium/strontium influences additional elongation of the average neurite length. Take advantage of hollow structure, NGF is encapsulated into HNPs, and they are further applied for directly inducing differentiation. The maximum differentiation efficiency is 67% in presence of the NGF‐encapsulated Sr‐HNP, which was 1.3 times higher than previous research. Furthermore, the neurite length is also 2.7 times higher than MnO2 decorated poly(3,4‐ethylenedioxythiophene) nanoellipsoids. Ba‐ and Sr‐HNP may offer a possibility for novel application of metal‐hybrid nanomaterials for cell differentiation, and can be expanded to other cellular applications.
Characterization of Conjugated Polymer Actuation under Cerebral Physiological Conditions
Authors: Daneshvar Eugene Dariush , Smela Elisabeth
Published: February 2014

Conjugated polymer actuators have potential use in implantable neural interface devices for modulating the position of electrode sites within brain tissue or guiding insertion of neural probes along curved trajectories. The actuation of polypyrrole (PPy) doped with dodecylbenzenesulfonate (DBS) is characterized to ascertain whether it can be employed in the cerebral environment. Microfabricated bilayer beams are electrochemically cycled at either 22 or 37 °C in aqueous NaDBS or in artificial cerebrospinal fluid (aCSF). Nearly all the ions in aCSF are exchanged into the PPy—the cations Na+, K+, Mg2+, Ca2+, as well as the anion PO43−; Cl− is not present. Nevertheless, deflections in aCSF are comparable to those in NaDBS and they are monotonic with oxidation level: strain increases upon reduction, with no reversal of motion despite the mixture of ionic charges and valences being exchanged. Actuation depends on temperature. Upon warming, the cyclic voltammograms show additional peaks and an increase of 70% in the consumed charge. Bending is, however, much less affected: strain increases somewhat (6%–13%) but remains monotonic, and deflections shift (up to 20%). These results show how the actuation environment must be taken into account, and demonstrate proof of concept for actuated implantable neural interfaces.
25th Anniversary Article: Materials for High‐Performance Biodegradable Semiconductor Devices
Authors: Hwang Suk‐Won , Park Gayoung , Cheng Huanyu , Song Jun‐Kyul , Kang Seung‐Kyun , Yin Lan , Kim Jae‐Hwan , Omenetto Fiorenzo G. , Huang Yonggang , Lee Kyung‐Mi , Rogers John A.
Published: February 2014

We review recent progress in a class of silicon‐based electronics that is capable of complete, controlled dissolution when immersed in water or bio‐fluids. This type of technology, referred to in a broader sense as transient electronics, has potential applications in resorbable biomedical devices, eco‐friendly electronics, environmental sensors, secure hardware systems and others. New results reported here include studies of the kinetics of hydrolysis of nanomembranes of single crystalline silicon in bio‐fluids and aqueous solutions at various pH levels and temperatures. Evaluations of toxicity using live animal models and test coupons of transient electronic materials provide some evidence of their biocompatibility, thereby suggesting potential for use in bioresorbable electronic implants.
25th Anniversary Article: Double Emulsion Templated Solid Microcapsules: Mechanics And Controlled Release
Authors: Datta Sujit S. , Abbaspourrad Alireza , Amstad Esther , Fan Jing , Kim Shin‐Hyun , Romanowsky Mark , Shum Ho Cheung , Sun Bingjie , Utada Andrew S. , Windbergs Maike , Zhou Shaobing , Weitz David A.
Published: February 2014

How droplet microfluidics can be used to fabricate solid‐shelled microcapsules having precisely controlled release behavior is described. Glass capillary devices enable the production of monodisperse double emulsion drops, which can then be used as templates for microcapsule formation. The exquisite control afforded by microfluidics can be used to tune the compositions and geometrical characteristics of the microcapsules with exceptional precision. The use of this approach to fabricate microcapsules that only release their contents when exposed to a specific stimulus – such as a change in temperature, exposure to light, a change in the chemical environment, or an external stress – only after a prescribed time delay, and at a prescribed rate is reviewed.
Application and Future Challenges of Functional Nanocarbon Hybrids
Authors: Shearer Cameron J. , Cherevan Alexey , Eder Dominik
Published: February 2014

Hybridizing nanocarbons, such as carbon nanotubes (CNTs) or graphene, with an active material is a powerful strategy towards designing next‐generation functional materials for environmental and sustainable energy applications. While research on nanocomposites, created by dispersing the nanocarbon into polymer or ceramic matrices, began almost immediately after the popularization of CNTs and graphene in 1991 and 2004, respectively, nanocarbon hybrids are a relatively recent addition to the family of composite materials. In contrast to nanocomposites, which typically combine the intrinsic properties of both compounds, nanocarbon hybrids additionally provide access to both a large surface area required for gas/liquid‐solid interactions and an extended interface, through which charge and energy transfer processes create synergistic effects that result in unique properties and superior performance. This progress report looks at the history of research on nanocarbons (fullerenes, CNTs and graphene) and their composites and hybrids, presents the origin of synergistic effects, reviews the most intriguing results on nanocarbon hybrid performance in heterogeneous catalysis, electrocatalysis, photocatalysis, batteries, supercapacitors, photovoltaics and sensors, and discusses remaining challenges and future research directions.
Growth Mechanism of Metal Clusters on a Graphene/Ru(0001) Template
Authors: Zhang L. Z. , Du S. X. , Sun J. T. , Huang L. , Meng L. , Xu W. Y. , Pan L. D. , Pan Y. , Wang Y. L. , Hofer W. A. , Gao H.‐J.
Published: February 2014

Using first‐principles calculations combined with scanning tunneling microscopy experiments, we investigated the adsorption configurations, electronic structures and the corresponding growth mechanism of several transition metal (TM) atoms (Pt, Ru, Ir, Ti, Pd, Au, Ag, and Cu) on a graphene/Ru(0001) moiré template (G/Ru(0001)) at low coverage. We find that Pt, Ru, Ir, and Ti selectively adsorb on the fcc region of G/Ru(0001) and form ordered dispersed metal nanoclusters. This behavior is due to the unoccupied d orbital of the TM atoms and the strong sp3 hybridization of carbon atoms in the fcc region of G/Ru(0001). Pd, Au, Ag, and Cu form nonselective structures because of the fully occupied d orbital. This mechanism can be extended to metals on a graphene/Rh(111) template. By using Pt as an example, we provide a layer by layer growth path for Pt nanoclusters in the fcc region of the G/Ru(0001). The simulations of growth mechanism agree well with the experimental observations. Moreover, they also provide guidance for the selection of suitable metal atoms to form ordered dispersed metal nanoclusters on similar templates.
2D Characterization of OPV from Single and Tandem Cells to Fully Roll‐to‐Roll Processed Modules with and without Electrical Contact
Authors: Krebs Frederik C. , Jørgensen Mikkel
Published: February 2014

A new type of light beam‐induced current 2D mapping system is developed that speeds up acquisition time from hours and days to minutes or even seconds. It is particularly relevant as a tool to characterize printed, large‐scale, organic photovoltaics. Defects inherent to the multi‐layer printing or degradation effects that develop later can be detected with a spatial resolution of <100 μm. It can be used as an in‐line characterization element in the roll‐to‐roll production of organic photovolatics. Several types of electrical connection schemes are developed, including methods suited for continuous web transport. One particularly exciting development is contactless connection through capacitive coupling, which is especially suited for fast roll‐to‐roll characterization of organic photovoltaic modules during the process where electrodes might not be accessible for making a physical electrical contact. Another variation of the technique allows for the extraction of solar cell parameters such as the capacitive time constant, capacitance, and shunt‐ and series resistance at every position (pixel) in the device, which allows new types of 2D mapping that bring out variations and defects in solar cells that are complementary to standard LBIC. It for instance becomes possible to distinguish a short from an open circuit.
Improved Open‐ Circuit Voltage in ZnO–PbSe Quantum Dot Solar Cells by Understanding and Reducing Losses Arising from the ZnO Conduction Band Tail
Authors: Hoye Robert L. Z. , Ehrler Bruno , Böhm Marcus L. , Muñoz‐Rojas David , Altamimi Rashid M. , Alyamani Ahmed Y. , Vaynzof Yana , Sadhanala Aditya , Ercolano Giorgio , Greenham Neil C. , Friend Richard H. , MacManus‐Driscoll Judith L. , Musselman Kevin P.
Published: February 2014

Colloidal quantum dot solar cells (CQDSCs) are attracting growing attention owing to significant improvements in efficiency. However, even the best depleted‐heterojunction CQDSCs currently display open‐circuit voltages (VOCs) at least 0.5 V below the voltage corresponding to the bandgap. We find that the tail of states in the conduction band of the metal oxide layer can limit the achievable device efficiency. By continuously tuning the zinc oxide conduction band position via magnesium doping, we probe this critical loss pathway in ZnO–PbSe CQDSCs and optimize the energetic position of the tail of states, thereby increasing both the VOC (from 408 mV to 608 mV) and the device efficiency.
Particle ordering in colloidal thin films deposited by flow‐coating
Authors: Lau Cindy Y. , Russel William B.
Published: February 2014

The wide applications of two‐dimensionally ordered nanoscale features have stimulated the development of cheap and fast fabrication techniques in recent years. We achieved large area of uniform film of nanoparticles between 49.8 ± 8.7 and 117.6 ± 6.7 nm via flow‐coating. However, the single crystalline domains of a close‐packed monolayer remained limited. That motivated deposition of initially ordered colloidal dispersions, attained through deionized solutions to extend electrostatic double layers for long‐range repulsion. Although the deposition agreed reasonably well with our power‐law model, the initial order was destroyed at high shear. While the particle order was partially preserved during deposition at low shear, the domain size was not particularly extensive due to the high compression of double layers during evaporation. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1287–1302, 2014
Influence of void fraction calculation on fidelity of CFD‐DEM simulation of gas‐solid bubbling fluidized beds
Authors: Peng Zhengbiao , Doroodchi Elham , Luo Caimao , Moghtaderi Behdad
Published: February 2014

The correct calculation of cell void fraction is pivotal in accurate simulation of two‐phase flows using a computational fluid dynamics‐discrete element method (CFD‐DEM) approach. Two classical approaches for void fraction calculations (i.e., particle centroid method or PCM and analytical approach) were examined, and the accuracy of these methodologies in predicting the particle‐fluid flow characteristics of bubbling fluidized beds was investigated. It was found that there is a critical cell size (3.82 particle diameters) beyond which the PCM can achieve the same numerical stability and prediction accuracy as those of the analytical approach. There is also a critical cell size (1/19.3 domain size) below which meso‐scale flow structures are resolved. Moreover, a lower limit of cell size (1.63 particle diameters) was identified to satisfy the assumptions of CFD‐DEM governing equations. A reference map for selecting the ideal computational cell size and the suitable approach for void fraction calculation was subsequently developed. © 2014 American Institute of Chemical EngineersAIChE J, 60: 2000–2018, 2014
Organocatalytic Asymmetric Conjugate Addition of 2‐Oxindole‐3‐Carboxylate Esters to 2‐Phthalimido Acrylates: Efficient Synthesis of Cγ‐tetrasubstituted α‐Amino Acid Derivatives
Authors: Gao Juan , Chen Jia‐Rong , Duan Shu‐Wen , Li Tian‐Ren , Lu Liang‐Qiu , Xiao Wen‐Jing
Published: February 2014

An organocatalytic asymmetric conjugate addition of 2‐oxindole‐3‐carboxylate esters to 2‐phthalimidoacrylates catalyzed by a quinine‐derived thiourea is described. The reaction provides efficient access to a variety of quaternary oxindole based Cγ‐tetrasubstituted α‐amino acid derivatives in good to excellent yields (up to 96 %) with moderate to good enantioselectivity (up to 90 % ee). The opposite enantiomers of the products can also be obtained with comparable yields and stereoselectivity by simply using a quinidine‐derived thiourea catalyst.
Exceptional expansion and conservation of a CT‐repeat complex in the core promoter of PAXBP1 in primates
Authors: Mohammadparast Saeid , Bayat Hadi , Biglarian Akbar , Ohadi Mina
Published: February 2014

Adaptive evolution may be linked with the genomic distribution and function of short tandem repeats (STRs). Proximity of the core promoter STRs to the +1 transcription start site (TSS), and their mutable nature are characteristics that highlight those STRs as a novel source of interspecies variation. The PAXBP1 gene (alternatively known as GCFC1) core promoter contains the longest STR identified in a Homo sapiens gene core promoter. Indeed, this core promoter is a stretch of four consecutive CT‐STRs. In the current study, we used the Ensembl, NCBI, and UCSC databases to analyze the evolutionary trend and functional implication of this CT‐STR complex in six major lineages across vertebrates, including primates, non‐primate mammals, birds, reptiles, amphibians, and fish. We observed exceptional expansion (≥4‐repeats) and conservation of this CT‐STR complex across primates, except prosimians, Microcebus murinus and Otolemur garnettii (Fisher exact P < 4.1 × 10−7). H. sapiens has the most complex STR formula, and longest repeats. Macaca mulatta and Callithrix jacchus monkeys have the simplest STR formulas, and shortest repeat numbers. CT ≥4‐repeats were not detected in non‐primate lineages. Different length alleles across the PAXBP1 core promoter CT‐STRs significantly altered gene expression in vitro (P < 0.001, t‐test). PAXBP1 has a crucial role in craniofacial development, myogenesis, and spine morphogenesis, properties that have been diverged between primates and non‐primates. To our knowledge, this is the first instance of expansion and conservation of a STR complex co‐occurring specifically with the primate lineage. Am. J. Primatol. 76:747–756, 2014. © 2014 Wiley Periodicals, Inc.
Chimpanzee diet: Phytolithic analysis of feces
Authors: Phillips Caroline , Lancelotti Carla
Published: February 2014

Most primate populations remain unobservable; therefore, researchers depend on the analyses of indirect evidence encountered at a study‐site in order to understand their behavioral ecology. Diet can be determined through the analyses of scats or feeding remains encountered on‐site. This allows aspects of their dietary repertoire to be established, which has implications both for conservation efforts (by locating food resources), and for understanding the evolution of hominin diet (if used as referential models). Macroscopic inspection of fecal samples is a common method applied to ascertain a primate population's diet. However, new approaches are required to identify food‐items unrecognizable at this level. We applied a dry ash extraction method to fecal samples (N = 50) collected from 10 adult chimpanzees in Kanyawara, Kibale National Park, Uganda and also to plant parts (N = 66) from 34 species known to be included in the diet of this community of apes. We recovered phytoliths in 26 of the 34 plant species. Fifteen phytolith morphotypes were only detected in 14 plant species (termed “distinct” phytoliths). We used these distinct phytoliths to identify plant foods (i.e., that they were associated with) in fecal samples. We then validated findings by checking if the 10 chimpanzees had eaten parts of these plants ∼24 hr prior to fecal sample collection; six plant species associated with five distinct phytoliths had been eaten. Finally, we compared plant foods identified in fecal samples from phytolith analyses with plants that had been identified from macroscopic inspection of the same fecal samples. Findings from phytolith analyses corroborate with those from macroscopic inspection by expanding the total number of plant species identified per fecal sample (i.e., we identified certain plant parts that remained unrecognizable at macroscopic level). This study highlights the potential of phytolith analyses of feces to increase our knowledgebase of the dietary repertoire of primate populations. Am. J. Primatol. 76:757–773, 2014. © 2014 Wiley Periodicals, Inc.
Developing a pig model for crypt fenestration‐induced localized hypoplastic enamel defects in humans
Authors: Skinner Mark F. , Rodrigues Antonia T. , Byra Chris
Published: February 2014

Hypoplastic pits on human deciduous canine teeth are attributed to nutritionally induced thinning of the crypt wall prior to eruption, exposing ameloblasts to unspecified physical trauma through the fenestration. Traditionally known as localized hypoplasia of the primary canine (LHPC), this little‐understood condition is reported in fields ranging from public health to bioarchaeology. We propose the defect be termed a ‘crypt fenestration hypoplastic enamel defect’ (CFED) to reflect that an analogous lesion is created postnatally on maxillary molars of pigs. Pigs are accepted as a suitable proxy for many studies in human biology. We compare fenestration defects and CFEDs between 50 Sick Pen pigs, who died naturally, and 20 Controls. Observations were made of the presence, number and size of fenestrations in molar crypts. CFEDs were counted on erupted deciduous last molars and permanent first molars. Signs of being underweight and cranio‐dental infection at death were recorded. Sick pen pigs show significantly more fenestrations at death and CFEDs acquired before death. These conditions co‐occur with infection and poor growth. The deep fibers of temporalis muscle lie adjacent to the crypt wall of maxillary molars. We propose that contraction of this muscle during suckling and chewing creates large compressive forces against fenestrated bony surfaces sufficient to have physiological consequences for physically unprotected ameloblasts. While we conclude that a pig model is appropriate to study fenestration‐induced enamel defects, this naturalistic experiment leaves unresolved whether osteopenia in pigs, and by extension in human infants, is due to disease and/or malnutrition. Am J Phys Anthropol 154:239–250, 2014. © 2014 Wiley Periodicals, Inc.
Synthese hochsubstituierter 3‐Formylfurane über eine Kaskade aus Gold(I)‐katalysierter Oxidation, 1,2‐Alkinylwanderung und Cyclisierung
Authors: Wang Tao , Shi Shuai , Hansmann Max M. , Rettenmeier Eva , Rudolph Matthias , Hashmi A. Stephen K.
Published: February 2014

3‐Formylfuranmotive bilden die Grundstrukturen einer Reihe bioaktiver Naturstoffe, allerdings sind für ihre Herstellung nur wenige Verfahren bekannt, die zudem nicht atomökonomisch sind: Sie erfordern mehrere Stufen oder harsche Reaktionsbedingungen und verlaufen unselektiv. Hier berichten wir über eine effiziente Gold(I)‐katalysierte Kaskadenreaktion, die aus leicht zugänglichen Ausgangsverbindungen zu 3‐Formylfuranen führt. Eine breite Palette von 3‐Formylfuranen wurde aus den jeweiligen symmetrischen und unsymmetrischen 1,4‐Diin‐3‐olen in Gegenwart eines N‐Oxids in guten bis ausgezeichneten Ausbeuten erhalten. Isotopenmarkierungsexperimente und DFT‐Rechnungen sprechen für einen Mechanismus, bei dem nach einer einleitenden Sauerstoffübertragung eine 1,2‐Alkinylwanderung gegenüber einer Hydridwanderung bevorzugt ist; dem schließt sich eine Cyclisierung zum gewünschten Furangrundgerüst an.
Kontrolle über Bildung und Bruch kovalenter Verknüpfungen durch Licht
Authors: Göstl Robert , Hecht Stefan
Published: February 2014

Der Wunsch nach Bauteilverkleinerung und die wachsende Komplexität von Strukturen auf dem Gebiet der Nanotechnologie verlangen nach der präzisen und kontrollierten Bildung kovalenter Bindungen auf molekularer Ebene. Eine solche Kontrolle erfordert jedoch den Einsatz externer Stimuli mit herausragender räumlicher, zeitlicher und energetischer Auflösung. Mit Licht adressierbare Schalter sind deshalb exzellente Kandidaten für Systeme, die eine reversible Photokontrolle über kovalente chemische Ver‐ und Entknüpfungen ermöglichen. Hier stellen wir ein solches System vor, das ausschließlich durch die Bestrahlung mit Licht unterschiedlicher Farbe kontrolliert werden kann. Zu diesem Zweck wurde ein Furyl‐substituiertes photoschaltbares Diarylethen konstruiert, das eine reversible Diels‐Alder‐Reaktion mit Maleinimid eingehen kann. Unser System verspricht Anwendungsmöglichkeiten in allen Gebieten, die schon jetzt die Vorteile von reversiblen Diels‐Alder‐Reaktionen nutzen.
Copper‐Catalyzed Intramolecular C(sp3)H and C(sp2)H Amidation by Oxidative Cyclization
Authors: Wang Zhen , Ni Jizhi , Kuninobu Yoichiro , Kanai Motomu
Published: February 2014

The first copper‐catalyzed intramolecular C(sp3)H and C(sp2)H oxidative amidation has been developed. Using a Cu(OAc)2 catalyst and an Ag2CO3 oxidant in dichloroethane solvent, C(sp3)H amidation proceeded at a terminal methyl group, as well as at the internal benzylic position of an alkyl chain. This reaction has a broad substrate scope, and various β‐lactams were obtained in excellent yield, even on gram scale. Use of CuCl2 and Ag2CO3 under an O2 atmosphere in dimethyl sulfoxide, however, leads to 2‐indolinone selectively by C(sp2)H amidation. Kinetic isotope effect (KIE) studies indicated that CH bond activation is the rate‐determining step. The 5‐methoxyquinolyl directing group could be removed by oxidation.
Autoamplification of Molecular Chirality through the Induction of Supramolecular Chirality
Authors: van Dijken Derk Jan , Beierle John M. , Stuart Marc C. A. , Szymański Wiktor , Browne Wesley R. , Feringa Ben L.
Published: February 2014

The novel concept for the autoamplification of molecular chirality, wherein the amplification proceeds through the induction of supramolecular chirality, is presented. A solution of prochiral, ring‐open diarylethenes is doped with a small amount of their chiral, ring‐closed counterpart. The molecules co‐assemble into helical fibers through hydrogen bonding and the handedness of the fibers is biased by the chiral, ring‐closed diarylethene. Photochemical ring closure of the open diarylethene yields the ring‐closed product, which is enriched in the template enantiomer.
A Concerted Transfer Hydrogenolysis: 1,3,2‐Diazaphospholene‐Catalyzed Hydrogenation of NN Bond with Ammonia–Borane
Authors: Chong Che Chang , Hirao Hajime , Kinjo Rei
Published: February 2014

1,3,2‐diazaphospholenes catalyze metal‐free transfer hydrogenation of a NN double bond using ammonia–borane under mild reaction conditions, thus allowing access to various hydrazine derivatives. Kinetic and computational studies revealed that the rate‐determining step involves simultaneous breakage of the BH and NH bonds of ammonia–borane. The reaction is therefore viewed as a concerted type of hydrogenolysis.
Diprotonated [28]Hexaphyrins(1.1.1.1.1.1): Triangular Antiaromatic Macrocycles
Authors: Ishida Shin‐ichiro , Higashino Tomohiro , Mori Shigeki , Mori Hirotaka , Aratani Naoki , Tanaka Takayuki , Lim Jong Min , Kim Dongho , Osuka Atsuhiro
Published: February 2014

Protonation of meso‐aryl [28]hexaphyrins(1.1.1.1.1.1) triggered conformational changes. Whereas protonation with trifluoroacetic acid led to the formation of monoprotonated Möbius aromatic species, protonation with methanesulfonic acid led to the formation of diprotonated triangular antiaromatic species. A peripherally hexaphenylated [28]hexaphyrin was rationally designed and prepared to undergo diprotonation to favorably afford a triangular‐shaped antiaromatic species.
Size‐Selective Complexation and Extraction of Endohedral Metallofullerenes with Cycloparaphenylene
Authors: Nakanishi Yusuke , Omachi Haruka , Matsuura Sanae , Miyata Yasumitsu , Kitaura Ryo , Segawa Yasutomo , Itami Kenichiro , Shinohara Hisanori
Published: February 2014

A new strategy for the non‐chromatographic extraction of metallofullerenes from solutions of arc‐processed raw soot is based on the size‐selective complexation with cycloparaphenylene (CPP). [11]CPP has a high affinity for Mx@C82 (x=1, 2); for example, Gd@C82 can be selectively extracted from a fullerene mixture by the addition of [11]CPP. This approach should open new opportunities in metallofullerene chemistry, including for the bulk extraction of metallofullerenes.
Deracemization By Simultaneous Bio‐oxidative Kinetic Resolution and Stereoinversion
Authors: Schrittwieser Joerg H. , Groenendaal Bas , Resch Verena , Ghislieri Diego , Wallner Silvia , Fischereder Eva‐Maria , Fuchs Elisabeth , Grischek Barbara , Sattler Johann H. , Macheroux Peter , Turner Nicholas J. , Kroutil Wolfgang
Published: February 2014

Deracemization, that is, the transformation of a racemate into a single product enantiomer with theoretically 100 % conversion and 100 % ee, is an appealing but also challenging option for asymmetric synthesis. Herein a novel chemo‐enzymatic deracemization concept by a cascade is described: the pathway involves two enantioselective oxidation steps and one non‐stereoselective reduction step, enabling stereoinversion and a simultaneous kinetic resolution. The concept was exemplified for the transformation of rac‐benzylisoquinolines to optically pure (S)‐berbines. The racemic substrates were transformed to optically pure products (ee>97 %) with up to 98 % conversion and up to 88 % yield of isolated product.
Pretreatment and kinetics of oil extraction from algae for biodiesel production
Authors: Valizadeh Derakhshan Mehrab , Nasernejad Bahram , Dadvar Mitra , Hamidi Mohammad
Published: February 2014

In this study, extraction of lipid from algal sp. Chlorella vulgaris is investigated based on Bligh and Dyer method employing methanol and chloroform on wet biomass. Optimization methodology was established on comparison of pretreatment methods as well as investigation of ultrasonication and stirrer parameters to enhance cell disruption. It was found that biomass with water/solid proportion (w/s = 5) operating temperature of 50 °C both for ultrasonication and shaking, 5 min ultrasonication with further 3 h of stirring with 200 rpm is the best set of parameters for breakdown of cell envelops, and using these parameters, total extraction of 22.07% was obtained. Kinetic study of breakdown was carried out with further full‐factorial investigation of extraction (%) vs time and temperature. Using Arrhenius equation, activation energy of about 34.73 kJ/mol was obtained for this algal sp. with R2 = 97.81%. Further analysis using analysis of variance showed that when using lower temperatures, sudden increase of extraction occurs in longer times, and vice versa, hence emphasizing the interaction thereof. It was also found that temperature plays the vital role among all examined parameters. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
Chemical and physical modifications of electrospun keratin nanofibers induced by heating treatments
Authors: Varesano Alessio , Vineis Claudia , Tonetti Cinzia , Ramírez Diego Omar Sánchez , Mazzuchetti Giorgio
Published: February 2014

In this study, we aimed to examine to study the effects of heating treatments on wool‐derived keratin nanofibers obtained by electrospinning. Interestingly, the keratin nanofibers did not lose their nanofibrous shape at high temperatures. On the contrary, the diameter of keratin nanofibers significantly decreased after heating. Even the chemical structure of the keratin was not significantly altered by heating, as observed by IR spectroscopy, except for a shoulder at 1720 cm−1 and the amide III band. The spectral feature changes matched the formation of crosslinking amide bonds between protein chains well. Moreover, for various applications, it is essential that nanofibers are stable in water. Heating treatments were carried out at different temperatures and times to assess what heating conditions gave the keratin nanofibers water stability. Finally, no significant changes in the thermal behavior were observed in the samples after heating treatments compared to the untreated keratin nanofibers; this was a sign of negligible or slight degradations of the protein chains. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40532.
Pullulan‐based films and coatings for food packaging: Present applications, emerging opportunities, and future challenges
Authors: Farris Stefano , Unalan Ilke Uysal , Introzzi Laura , Fuentes‐Alventosa José Maria , Cozzolino Carlo A.
Published: February 2014

Societal and industrial demands for lower environmental impact, cost effectiveness, and high‐performance goods and services are increasingly impacting the choice of technologies which are developed and deployed in consumer products. Like many other sectors, food packaging is moving to new technologies; the use of biopolymers is one of the most promising strategies toward an optimized use of traditional packaging materials (e.g., oil‐based plastics) without impairing the goal of extending shelf life. Among other food packaging materials, pullulan is attracting much attention due to its unique features. The goal of this review is to provide an overview of current and emerging applications of pullulan within the food packaging sector. In particular, the functional properties of interest for the food packaging industry will be discussed in light of the physicochemical attributes of this exopolysaccharide. Future challenges that may dictate the successful penetration of pullulan in the food packaging market are also outlined. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40539.
Independent learning modules enhance student performance and understanding of anatomy
Authors: Serrat Maria A. , Dom Aaron M. , Buchanan James T. , Williams Alison R. , Efaw Morgan L. , Richardson Laura L.
Published: February 2014

Didactic lessons are only one part of the multimodal teaching strategies used in gross anatomy courses today. Increased emphasis is placed on providing more opportunities for students to develop lifelong learning and critical thinking skills during medical training. In a pilot program designed to promote more engaged and independent learning in anatomy, self‐study modules were introduced to supplement human gross anatomy instruction at Joan C. Edwards School of Medicine at Marshall University. Modules use three‐dimensional constructs to help students understand complex anatomical regions. Resources are self‐contained in portable bins and are accessible at any time. Students use modules individually or in groups in a structured self‐study format that augments material presented in lecture and laboratory. Pilot outcome data, measured by feedback surveys and examination performance statistics, suggest that the activity may be improving learning in gross anatomy. Positive feedback on both pre‐ and post‐examination surveys showed that students felt the activity helped to increase their understanding of the topic. In concordance with student perception, average examination scores on module‐related laboratory and lecture questions were higher in the two years of the pilot program compared with the year before its initiation. Modules can be fabricated on a modest budget using minimal resources, making implementation practical for smaller institutions. Upper level medical students assist in module design and upkeep, enabling continuous opportunities for vertical integration across the curriculum. This resource offers a feasible mechanism for enhancing independent and lifelong learning competencies, which could be a valuable complement to any gross anatomy curriculum. Anat Sci Educ 7: 406–416. © 2014 American Association of Anatomists.
Self‐training author name disambiguation for information scarce scenarios
Authors: Ferreira Anderson A. , Veloso Adriano , Gonçalves Marcos André , Laender Alberto H. F.
Published: February 2014

We present a novel 3‐step self‐training method for author name disambiguation—SAND (self‐training associative name disambiguator)—which requires no manual labeling, no parameterization (in real‐world scenarios) and is particularly suitable for the common situation in which only the most basic information about a citation record is available (i.e., author names, and work and venue titles). During the first step, real‐world heuristics on coauthors are able to produce highly pure (although fragmented) clusters. The most representative of these clusters are then selected to serve as training data for the third supervised author assignment step. The third step exploits a state‐of‐the‐art transductive disambiguation method capable of detecting unseen authors not included in any training example and incorporating reliable predictions to the training data. Experiments conducted with standard public collections, using the minimum set of attributes present in a citation, demonstrate that our proposed method outperforms all representative unsupervised author grouping disambiguation methods and is very competitive with fully supervised author assignment methods. Thus, different from other bootstrapping methods that explore privileged, hard to obtain information such as self‐citations and personal information, our proposed method produces topnotch performance with no (manual) training data or parameterization and in the presence of scarce information.