bluuebunny/crossref_metadata_2025_split huggingface dataset:
Permafrost: Definition and Extent
Authors: Dobiński Wojciech 
Published: October 2018

Permafrost is a rock or soil the temperature of which is ≤0°C for at least two consecutive years. It is formed as a result of a freezing climate. It occurs at all latitudes around the world in continuous, discontinuous, sporadic, and isolated patches and covers more than 36 × 10
6
km
2
. It is invisible and separated from the surface by an active layer from zero to several meters thick. The Arctic permafrost is connected with colder weather resulting from the increase of latitude. In the Northern Hemisphere it covers especially: Canada, Alaska, and Siberia, with a depth reaching up to 1500 m. Mountain permafrost begins at an altitude of 500 m above sea level and reaches up to an altitude of 8848 m in the Himalayas. In the Southern Hemisphere it covers Antarctica and the mountain range of the Andes, about 13.5 × 10
6
km
2
in total. It also occurs in space.
Diffusion MRI abnormalities in adolescent rats given repeated mild traumatic brain injury
Authors: Wortman Ryan C. , Meconi Alicia , Neale Katie J. , Brady Rhys D. , McDonald Stuart J. , Christie Brian R. , Wright David K. , Shultz Sandy R. 
Published: October 2018

AbstractObjectiveMild traumatic brain injury (mTBI) is a serious health concern in the adolescent population. Repeated mTBI may result in more pronounced deficits, and has been associated with long‐term neurological consequences including neurodegeneration. As such, there is a critical need for the development of objective mTBI biomarkers to help guide medical management. Diffusion‐weighted imaging (DWI) is an advanced magnetic resonance imaging (MRI) technique that may detect brain abnormalities after mTBI. Diffusion tensor imaging (DTI) is the most commonly applied DWI method, and initial studies have reported DTI changes in mTBI patients. Furthermore, new DWI methods (e.g., track‐weighted imaging; TWI) are being developed that may also be sensitive to mTBIs, but remain to be comprehensively studied.MethodsThis study utilized the Awake Closed Head Injury (ACHI) model of mTBI to investigate changes in DTI and TWI following repeated mTBI in adolescent male and female rats. A total of four ACHI impacts, two/day over two consecutive days, were delivered beginning on postnatal day 25. At 1 day and 7 days postinjury, rats were euthanized and brains were collected for DWI analyses.ResultsRats given repeated mTBI displayed changes in fractional anisotropy and radial diffusivity (i.e., DTI measures), as well as track density (i.e., TWI).InterpretationThese findings are consistent with initial DTI findings in mTBI patients, suggest that TWI may complement DTI, support the utility of DWI measures as biomarkers in mTBI, and further validate the ACHI rat model of mTBI.
Effect of the Molecular Polarizability of SAMs on the Work Function Modification of Gold: Closed‐ versus Open‐Shell Donor–Acceptor SAMs
Authors: Diez‐Cabanes Valentin , Morales Dayana C. , Souto Manuel , Paradinas Markos , Delchiaro Francesca , Painelli Anna , Ocal Carmen , Cornil David , Cornil Jérôme , Veciana Jaume , Ratera Imma 
Published: October 2018

AbstractCharge injection barriers at metal/organic interfaces can be tuned by modifying the work function of metallic electrodes using self‐assembled monolayers (SAMs) of polar molecules. An interesting example of polar molecules is offered by donor–acceptor (D–A) dyads based on ferrocene (Fc) as electron‐donor unit and either a polychlorotriphenylmethyl radical or a polychlorotriphenylmethane as electron‐acceptor units, connected by a π‐conjugated vinylene bridge. The D–A radical exhibits high chemical and thermal stability and presents different electronic, optical, and magnetic properties with respect to the closed‐shell form. The magnitude of the shift in the charge injection barriers for these two D–A systems is estimated by means of surface potential measurements performed by Kelvin probe force microscopy. The experimental data are compared with density functional theory calculations, which evidence the importance of the molecular dipole moments and polarizabilities to understand the experimental values. In order to achieve high work function shifts of metals upon SAM formation, the molecules forming the SAM have to exhibit both a high permanent dipole moment and a low polarizability along the direction normal to the substrate. In presence of polarizable molecules, the work function shifts can be enhanced by reducing the intermolecular interactions; by using mixed SAMs with active molecules embedded into a passive matrix.
Spray‐Coated Organic Photodetectors and Image Sensors with Silicon‐Like Performance
Authors: Biele Markus , Montenegro Benavides Cindy , Hürdler Judith , Tedde Sandro F. , Brabec Christoph J. , Schmidt Oliver 
Published: October 2018

AbstractSolution‐processed bulk heterojunction based organic photodiodes are ideal candidates for large‐area light sensing. Here, spray‐coated large‐area organic photodiodes based on a novel polymer (Lisicon PV‐D4650) with dark current densities down to 34 pA cm−2 and a maximum responsivity of ≈0.44 A W−1@660 nm under reverse bias conditions of −5 V are reported. These values are comparable to commercially available state‐of‐the‐art solid‐state photodetectors. Furthermore, cutoff frequencies of 50 kHz and a linear dynamic range exceeding eight orders of magnitude or ≥160 dB are achieved. The usage of 1,8‐diiodooctane as processing additive for spray coating vastly reduces the surface roughness of spray‐coated organic photodiodes which facilitates the preparation of large‐area light sensors and image sensors.
Therapeutic Applications of Phytoplankton, with an Emphasis on Diatoms and Coccolithophores
Authors: Lomora Mihai , Shumate David , Rahman Asrizal Abdul , Pandit Abhay 
Published: October 2018

AbstractPhytoplankton are complex living organisms that have attracted significant interest in the field of biomedicine. One subclass of phytoplankton, the diatoms, produce elegant self‐assembled siliceous architectural features with a complex 3D porous structure. Diatoms are characterized by a distinct 3D architecture of silica cell walls called frustules with a highly ordered nano‐/micropore structure and pattern. Another phytoplankton subclass of interest is the coccolithophore, which produces unique calcium carbonate plates with distinct architectural features called coccoliths. The unique morphological characteristics of coccoliths resembling the shape of a wagon wheel allows a higher surface area, thus an increased amount of immobilized therapeutic agent on their surface compared to a synthetic calcium carbonate microparticle. This review offers a summary of phytoplankton (microalgae) and their potential for application in drug delivery, diagnostics, drug discovery, as molecular factories, and as scaffolds for various therapeutic applications.
Superior Sensing Properties of Black Phosphorus as Gas Sensors: A Case Study on the Volatile Organic Compounds
Authors: Ou Pengfei , Song Pengfei , Liu Xinyu , Song Jun 
Published: October 2018

AbstractThe unique structure and prominent properties of black phosphorus (BP) and its monolayer and multilayers in device applications have attracted significant attention to this elemental 2D material. In this study, a comprehensive evaluation of the candidacy of monolayer BP as a channel material for high‐performance volatile organic compound (VOC) sensors is conducted combining first‐principles density functional theory calculations and non‐equilibrium Green's function formalism. The adsorption configurations and energetics of several typical VOCs (ethanol, propionaldehyde, acetone, toluene, and hexane) on monolayer BP are examined and it is demonstrated that VOCs generally exhibit stronger interaction with monolayer BP than with the widely studied monolayer MoS2, indicative of monolayer BP potentially being a more sensitive VOC sensor. Monolayer BP is shown to exhibit highly anisotropic transport behaviors, whereas the absolute modification of current–voltage responses due to VOCs is found to show a trend that is direction independent. Moreover, the adsorption of VOCs on monolayer BP is strong enough to resist thermal disturbance, yet allows fast recovery time. The results suggest that BP is a compelling and feasible candidate for sensing applications of VOCs.
Direct Synthesis and Pseudomorphic Transformation of Mixed Metal Oxide Nanostructures with Non‐Close‐Packed Hollow Sphere Arrays
Authors: Liu Zhendong , Zhao Wenyang , Kumar Prashant , Li Xinyu , Al Wahedi Yasser , Mkhoyan K. Andre , Tsapatsis Michael , Stein Andreas 
Published: October 2018

AbstractWhile bottom‐up syntheses of ordered nanostructured materials at colloidal length scales have been successful at producing close‐packed materials, it is more challenging to synthesize non‐close‐packed (ncp) structures. Here, a metal oxide nanostructure with ncp hollow sphere arrays was synthesized by combining a polymeric colloidal crystal template (CCT) with a Pechini precursor. The CCT provided defined confinement through its tetrahedral (Td) and octahedral (Oh) voids where the three‐dimensionally (3D) ordered, ncp hollow sphere arrays formed as a result of a crystallization‐induced rearrangement. This nanostructure, consisting of alternating, interconnected large and small hollow spheres, is distinct from the inverse opal structures typically generated from these CCTs. The morphology of the ncp hollow sphere arrays was retained in pseudomorphic transformations involving sulfidation and reoxidation cycling despite the segregation of zinc during these steps.
Proton‐Activated “Off–On” Room‐Temperature Phosphorescence from Purely Organic Thioethers
Authors: Huang Linkun , Chen Biao , Zhang Xuepeng , Trindle Carl O. , Liao Fan , Wang Yucai , Miao Hui , Luo Yi , Zhang Guoqing 
Published: October 2018

AbstractRoom‐temperature phosphorescence (RTP)‐based sensors have distinctive advantages over the fluorescence counterparts, such as larger Stokes shifts and longer lifetimes. Unfortunately, almost all RTP sensors are operated on quenching‐based mechanisms given the sensitive nature of the emissive triplet state. Here we report a type of thioether RTP molecules that shows RTP “turn‐on” when volatile acid vapors such as HCl are in contact. To elucidate the underlying mechanism, model thioethers containing different donor/acceptor combinations are investigated via fluorescence spectroscopy and theoretical calculations aided by molecular coordinates obtained from single‐crystal X‐ray diffraction. It is revealed that a charge‐transfer character in the phosphorescence state is crucial. The “turn‐on” design concept may significantly broaden the sensing application scope for organic RTP molecules.
Phenytoin‐induced choreoathetosis after serial seizures due to traumatic brain injury and chronic alcoholism
Authors: Finsterer Josef , Keller Hans , Reining‐Festa Alice , Enzelsberger Barbara , Weidinger Franz 
Published: October 2018

Key Clinical MessageIntravenous phenytoin (PHT) for suspected seizures may trigger severe choreoathetosis. Discontinuation of PHT results in immediate and complete resolution of hyperkinesias. Co‐medication with valproic acid, levetiracetam, tranquilisers, and anesthetics or alcohol presumably do not modify this adverse effect of PHT. Choreoathetosis can be easily misinterpreted as seizures.
Seizure manifesting as a reaching/grasping movement in a patient with post‐traumatic epilepsy
Authors: Horinouchi Toru , Sakurai Kotaro , Kurita Tsugiko , Takeda Youji , Yoshida Yusuke , Akiyama Hisashi , Fukushima Katsuyuki , Kusumi Ichiro 
Published: October 2018

Key Clinical MessageElectrical stimulation (ES) of the pre‐supplementary or cingulate motor area can cause reaching/grasping (R/G) movements with the hand contralateral to the side of the brain receiving the ES. We report this phenomenon occurring in a 23‐year‐old right‐handed man during spontaneous epileptic seizure, which developed after traumatic brain injury.
One‐step Synthesis of Self‐standing Ni3S2/Ni2P Heteronanorods on Nickel Foam for Efficient Electrocatalytic Hydrogen Evolution over a Wide pH Range
Authors: Zhou Yun , Li Tongtong , Xi Shengqi , He Cheng , Yang Xigang , Wu Hongjing 
Published: October 2018

AbstractThe development of efficient, stable and low‐cost electrocatalysts for hydrogen evolution reaction (HER) through a facile strategy is undoubtedly vital to realize sustainable production of H2 in water splitting but still challenging. Herein, we present a one‐step approach, a simultaneous phosphorization and sulfurization thermal treatment of NF at low temperature, to direct grow Ni‐S−P heteronanorod arrays consisting of Ni3S2 and Ni2P on nickel foam (Ni‐S−P NRs/NF). Due to the direct growth, one‐dimensional structure and good conductivity of the catalyst hybrid, as well as the synergistic effect between Ni3S2 and Ni2P, the resultant Ni‐S−P NRs/NF exhibited excellent HER electrocatalytic activity over a wide pH range. Ni‐S−P NRs/NF shows an overpotential of 180, 148 and 292 mV to reach the current density of 100 mA cm−2 in 1.0 M KOH, 0.5 M H2SO4 and 1.0 M PBS solution, respectively. DFT theoretical calculations was further confirmed that the superior pH‐universal HER activity of Ni‐S−P NRs/NF is originated from the thermo‐neutral hydrogen adsorption free energy and the enhanced adsorption of water molecular by the Ni3S2/Ni2P heterostructure.
Experimental and Computational Mechanistic Studies of the β‐Diketiminatoiron(II)‐Catalysed Hydroamination of Primary Aminoalkenes
Authors: Lepori Clément , Bernoud Elise , Guillot Régis , Tobisch Sven , Hannedouche Jérôme 
Published: October 2018

AbstractA comprehensive mechanistic study by means of complementary experimental and computational approaches of the exo‐cyclohydroamination of primary aminoalkenes mediated by the recently reported β‐diketiminatoiron(II) complex B is presented. Kinetic analysis of the cyclisation of 2,2‐diphenylpent‐4‐en‐1‐amine (1 a) catalysed by B revealed a first‐order dependence of the rate on both aminoalkene and catalyst concentrations and a primary kinetic isotope effect (KIE) (kH/kD) of 2.7 (90 °C). Eyring analysis afforded ΔH≠=22.2 kcal mol−1, ΔS≠=−13.4 cal mol−1 K−1. Plausible mechanistic pathways for competitive avenues of direct intramolecular hydroamination and oxidative amination have been scrutinised computationally. A kinetically challenging proton‐assisted concerted N−C/C−H bond‐forming non‐insertive pathway is seen not to be accessible in the presence of a distinctly faster σ‐insertive pathway. This operative pathway involves 1) rapid and reversible syn‐migratory 1,2‐insertion of the alkene into the Fe−Namido σ bond at the monomer {N^N}FeII amido compound; 2) turnover‐limiting Fe−C σ bond aminolysis at the thus generated transient {N^N}FeII alkyl intermediate and 3) regeneration of the catalytically competent {N^N}FeII amido complex, which favours its dimer, likely representing the catalyst resting state, through rapid cycloamine displacement by substrate. The collectively derived mechanistic picture is consonant with all empirical data obtained from stoichiometric, catalytic and kinetics experiments.
Malignancy rate of atypia of undetermined significance/follicular lesion of undetermined significance in thyroid nodules undergoing FNA in a suburban endocrinology practice: A retrospective cohort analysis
Authors: Seagrove‐Guffey Maighan A. , Hatic Haris , Peng Haoran , Bates Kimberly C. , Odugbesan A. Ola 
Published: October 2018

AbstractBackgroundThe Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) was created to establish a standard terminology regarding thyroid nodules that can be shared between endocrinologists, pathologists, radiologists, and surgeons. Since its inception and use in 2009, multiple large hospitals and academic institutions have performed retrospective studies to compare their classification rates, specifically those of atypia of undetermined significance (AUS) and follicular lesion of undetermined significance (FLUS), with the recommended rates created by the National Cancer Institute. The current study compared AUS/FLUS rates at a private suburban endocrine practice with those of previous publications from large institutions and the rates established by the National Cancer Institute.MethodsCharts from 893 patients with fine‐needle aspiration (FNA) performed in 2015 were reviewed. Data specific to thyroid aspirates classified as AUS/FLUS were organized into whether patients underwent surgery, underwent subsequent repeat FNA, or required continued observation. These results then were calculated to reveal the rate of malignancy in the AUS/FLUS category with surgical pathology in the study institution.ResultsA total of 893 patients underwent FNA, with 43 patients (4.82%) shown to have AUS/FLUS. A total of 21 patients proceeded to undergo thyroidectomy or lobectomy, with 7 patients (33.3%) found to have papillary or follicular thyroid carcinoma.ConclusionsThe rate of use of the AUS/FLUS category for thyroid nodules examined at the study institution was found to be within the recommended range set forth by TBSRTC. However, the malignancy rates on histopathology in the study institution were found to be higher than the new proposed malignancy rates from TBSRTC published in 2017. This finding is comparable to those of multiple other community and academic institutions performed prior to and after institution of the new guidelines.
An interactive control system for mobile robot based on cloud services
Authors: Zhang Lei , Zhang Kaibo 
Published: October 2018

SummaryVisual interaction is one of the most important ways for mobile robots to serve the elderly in the future. Mobile robots need to recognize human movements to follow human movements or evade actions. An indoor mobile robot interaction system based on cloud servers is presented. In a human‐machine coexistence environment, the mobile robot recognizes human motion, which represents the control intention for robot. In addition, if the person does not issue a control command, the robot follows the operator moving trajectory as a follower. A mobile robot with four Mecanum wheels is used in experiments. In the robot, a 3D camera is used to capture human motion and recognizes the language control commands. Then, the mobile robot executes the command action after translating the human body language to its motion direction control mode. Moreover, a 2D camera in the robot is used to autonomously capture 2D human multi‐view images and combines facial recognition to achieve specific human target to follow‐up. Some experiments are presented to verify the effectiveness of the whole Interaction control system.
Surface Modifications of Ti2CO2 for Obtaining High Hydrogen Evolution Reaction Activity and Conductivity: A Computational Approach
Authors: Wang Shuo , Chen Liang , Wu Yang , Zhang Qiuju 
Published: October 2018

AbstractThe identification of hydrogen evolution reaction (HER) catalysts with high conductivity and high activity is the top priority in the development of renewable energy. Oxygen‐terminated Ti2C (Ti2CO2), as one of the typical MXenes, shows good HER Gibbs free energy (ΔGH) at low hydrogen coverage, whereas the large band gap of approximately 1.0 eV limits its conductivity capability. By doping phosphor (P) or sulfur (S) to partially substitute the surficial O, the average free energy (ΔGHa) at various hydrogen coverages has been draggd to approach zero, and the conductivity is also significantly improved by narrowing the band gap to lower than 0.3 eV. Partial charge analysis indicates that doping P or S on the surface induces the diffusion of electrons on oxygen from O 2px to O 2pz, resulting in O 2pz reaction with H 1s. The facial overlapping of H 1s with O 2pz will strengthen the binding strength, hence lowering ΔGH. The energy shift toward Fermi level of Ti 3d after P or S doping contributes to the reduced band gap and high conductivity. Surficial O or P vacancies are created to evaluate the vacancy effect on HER performance, which not only improves ΔGHa and conductivity but also leads to a low reaction barrier of H2O splitting (<0.2 eV). The armchair nanoribbon (ANR) displays improved HER activity by P‐doping at 50% ratio. Our research shows that modification of end‐group in MXenes can effectively improve HER catalytic activity and conductivity, which is expected to promote their potential applications in electrocatalysis and energy conversion.
Managing birds of conservation concern on sandy shores: How much room for future conservation actions is there?
Authors: Maslo Brooke , Leu Karen , Pover Todd , Weston Michael A. , Schlacher Thomas A. 
Published: October 2018

AbstractResource limitations often prevent the active management required to maintain habitat quality in protected areas. Because restrictions in access or allowable public activities are the sole conservation measure in these locations, an important question to consider is whether species of conservation concern truly benefit from parcels that are shielded from human disturbance. Here, we assess the conservation benefit of protecting birds from human recreation on over 204 km of sandy beaches by (a) estimating the total area of beach‐nesting bird habitat that has been created by conservation protections; (b) quantifying the change in nesting habitat extent should further conservation protections be implemented; and (c) providing data to inform future protected area expansion. We use a maximum entropy species distribution modeling approach to estimate the extent and quality of suitable habitat for four beach‐nesting bird species of conservation concern under the existing management regime and compare it to scenarios in which the entire study area is either unprotected of fully protected from human disturbance. Managing humans has dramatic conservation returns for least terns and piping plovers, creating extensive nesting habitat that otherwise would not exist. There is considerable scope for conservation gains, potentially tripling the extent of nesting areas. Expanding conservation footprints for American oystercatchers and black skimmers is predicted to enhance the quality of existing nesting areas. The work demonstrates the utility of modeling changes in habitat suitability to inform protected area expansion on ocean beaches and coastal dunes.
Soil organic carbon dynamics matching ecological equilibrium theory
Authors: Caruso Tancredi , De Vries Franciska T. , Bardgett Richard D. , Lehmann Johannes 
Published: October 2018

AbstractThe persistence of soil organic carbon (SOC) has traditionally been explained as a combination of recalcitrance properties and stabilization processes, which lead to the formation of complex organic compounds. However, recent conceptual advances and experimental evidence challenge this view. Here, we test these conceptual advances using a dynamic equilibrium theory of SOC founded on classic ecological theory. We postulate that the persistence of SOC is an equilibrium point where SOC losses resulting from continuous decomposition and SOC gains due to SOC protection are balanced. We show that we can describe the temporal dynamics of SOC remarkably well (average and median R2 = 0.75) in publicly available SOC time series from experiments that investigated the effects of agricultural practices in arable soils. The predictive power of our simplistic model is not meant to compete with that of current multi‐pool SOC models or recent developments that include microbial loops. The simplicity of our analysis can, however, show how the conceptual distinction between the forces that control SOC loss and gain, and their equilibrium, can shed light on SOC dynamics. Specifically, our analysis shows that, regardless of specific mechanisms, the persistence of SOC will depend on the ultimate equilibrium between SOC gains and losses, which may depend on environmental (e.g. temperature) and ecological (e.g. spatially structured microbial activities) factors and the relative roles of these factors. Future experimental studies should quantify these roles to formulate a new generation of SOC dynamics model.