Showing papers by "University of Delaware published in 2015"
University of Washington1, Pacific Northwest National Laboratory2, Radcliffe Institute for Advanced Study3, University of Wisconsin-Madison4, Eindhoven University of Technology5, University of Minnesota6, Lawrence Berkeley National Laboratory7, Northwestern University8, University of California, Berkeley9, University of Houston10, University of California, Davis11, University of Delaware12, Virginia Tech13, University of Leeds14, University of Konstanz15
TL;DR: The current understanding of CPA is described, some of the nonclassical thermodynamic and dynamic mechanisms known to give rise to experimentally observed pathways are examined, and the challenges to the understanding of these mechanisms are highlighted.
Abstract: Field and laboratory observations show that crystals commonly form by the addition and attachment of particles that range from multi-ion complexes to fully formed nanoparticles. The particles involved in these nonclassical pathways to crystallization are diverse, in contrast to classical models that consider only the addition of monomeric chemical species. We review progress toward understanding crystal growth by particle-attachment processes and show that multiple pathways result from the interplay of free-energy landscapes and reaction dynamics. Much remains unknown about the fundamental aspects, particularly the relationships between solution structure, interfacial forces, and particle motion. Developing a predictive description that connects molecular details to ensemble behavior will require revisiting long-standing interpretations of crystal formation in synthetic systems, biominerals, and patterns of mineralization in natural environments.
1,357 citations
TL;DR: Recent advances in understanding global soil resources, including how carbon stored in soil responds to anthropogenic warming are reviewed, reveal the severity of soil-related issues at stake for the remainder of this century and the need to rapidly regain a balance to the physical and biological processes that drive and maintain soil properties.
Abstract: Human security has and will continue to rely on Earth's diverse soil resources. Yet we have now exploited the planet's most productive soils. Soil erosion greatly exceeds rates of production in many agricultural regions. Nitrogen produced by fossil fuel and geological reservoirs of other fertilizers are headed toward possible scarcity, increased cost, and/or geopolitical conflict. Climate change is accelerating the microbial release of greenhouse gases from soil organic matter and will likely play a large role in our near-term climate future. In this Review, we highlight challenges facing Earth's soil resources in the coming century. The direct and indirect response of soils to past and future human activities will play a major role in human prosperity and survival.
852 citations
TL;DR: Flexible compounds Fe(bdp) and Co(BDp) (bdp2− = 1,4-benzenedipyrazolate) are shown to undergo a structural phase transition in response to specific CH4 pressures, resulting in adsorption and desorption isotherms that feature a sharp ‘step’.
Abstract: Two flexible metal-organic frameworks are presented as solid adsorbents for methane that undergo reversible phase transitions at specific methane pressures, enabling greater storage capacities of usable methane than have been achieved previously, while also providing internal heat management of the system. Natural gas — methane — is a clean and cheap fuel but its usefulness in transport applications is limited by storage problems, given its low energy density per unit volume under ambient conditions compared with petrol or diesel. One way of increasing methane storage capacity is to use tanks containing porous materials, such as metal–organic frameworks, as a storage medium. However, for every methane molecule adsorbed and desorbed there is an associated thermal fluctuation that could cause overheating or reduce storage efficiency if left unchecked. Here Jeffrey Long and colleagues describe two flexible metal–organic frameworks that undergo reversible phase transitions at specific methane pressures, enabling greater storage capacities of usable methane than have been achieved previously, while also providing internal heat management of the system. As a cleaner, cheaper, and more globally evenly distributed fuel, natural gas has considerable environmental, economic, and political advantages over petroleum as a source of energy for the transportation sector1,2. Despite these benefits, its low volumetric energy density at ambient temperature and pressure presents substantial challenges, particularly for light-duty vehicles with little space available for on-board fuel storage3. Adsorbed natural gas systems have the potential to store high densities of methane (CH4, the principal component of natural gas) within a porous material at ambient temperature and moderate pressures4. Although activated carbons, zeolites, and metal–organic frameworks have been investigated extensively for CH4 storage5,6,7,8, there are practical challenges involved in designing systems with high capacities and in managing the thermal fluctuations associated with adsorbing and desorbing gas from the adsorbent. Here, we use a reversible phase transition in a metal–organic framework to maximize the deliverable capacity of CH4 while also providing internal heat management during adsorption and desorption. In particular, the flexible compounds Fe(bdp) and Co(bdp) (bdp2− = 1,4-benzenedipyrazolate) are shown to undergo a structural phase transition in response to specific CH4 pressures, resulting in adsorption and desorption isotherms that feature a sharp ‘step’. Such behaviour enables greater storage capacities than have been achieved for classical adsorbents9, while also reducing the amount of heat released during adsorption and the impact of cooling during desorption. The pressure and energy associated with the phase transition can be tuned either chemically or by application of mechanical pressure.
737 citations
TL;DR: Three-dimensional porous crystalline polyimide covalent organic frameworks (termed PI-COFs) have been synthesized and show high thermal stability and surface area and high loading and good release control for drug delivery applications.
Abstract: Three-dimensional porous crystalline polyimide covalent organic frameworks (termed PI-COFs) have been synthesized. These PI-COFs feature non- or interpenetrated structures that can be obtained by choosing tetrahedral building units of different sizes. Both PI-COFs show high thermal stability (>450 °C) and surface area (up to 2403 m2 g–1). They also show high loading and good release control for drug delivery applications.
730 citations
TL;DR: The correlation between hydrogen oxidation/evolution activity and experimentally measured hydrogen binding energy for polycrystalline platinum examined in several buffer solutions in a wide range of electrolyte pH is reported, strongly supporting the hypothesis that hydrogen binding power is the sole reaction descriptor for the hydrogen oxidation-evolution reaction on monometallic platinum.
Abstract: The hydrogen oxidation/evolution reactions are two of the most fundamental reactions in distributed renewable electrochemical energy conversion and storage systems. The identification of the reaction descriptor is therefore of critical importance for the rational catalyst design and development. Here we report the correlation between hydrogen oxidation/evolution activity and experimentally measured hydrogen binding energy for polycrystalline platinum examined in several buffer solutions in a wide range of electrolyte pH from 0 to 13. The hydrogen oxidation/evolution activity obtained using the rotating disk electrode method is found to decrease with the pH, while the hydrogen binding energy, obtained from cyclic voltammograms, linearly increases with the pH. Correlating the hydrogen oxidation/evolution activity to the hydrogen binding energy renders a monotonic decreasing hydrogen oxidation/evolution activity with the hydrogen binding energy, strongly supporting the hypothesis that hydrogen binding energy is the sole reaction descriptor for the hydrogen oxidation/evolution activity on monometallic platinum.
696 citations
TL;DR: This work performs a new accuracy evaluation of the JILA Sr clock, reducing many systematic uncertainties that limited previous measurements, such as those in the lattice ac Stark shift, the atoms' thermal environment and the atomic response to room-temperature blackbody radiation.
Abstract: Atomic clocks are increasingly important for many applications in scientific research and technology. Here, Nicholson et al. present a series of developments allowing them to achieve a new record in atomic clock performance, with a systematic uncertainty of just 2.1 × 10−18 for their 87Sr atomic clock.
695 citations
TL;DR: In this paper, the authors apply a text analytical approach to a large quantity of consumer reviews extracted from Expedia.com to deconstruct hotel guest experience and examine its association with satisfaction ratings.
662 citations
TL;DR: A way to define the potential educational impact of current and future apps is offered and how the design and use of educational apps aligns with known processes of children’s learning and development is shown to offer a framework that can be used by parents and designers alike.
Abstract: Children are in the midst of a vast, unplanned experiment, surrounded by digital technologies that were not available but 5 years ago. At the apex of this boom is the introduction of applications ("apps") for tablets and smartphones. However, there is simply not the time, money, or resources available to evaluate each app as it enters the market. Thus, "educational" apps-the number of which, as of January 2015, stood at 80,000 in Apple's App Store (Apple, 2015)-are largely unregulated and untested. This article offers a way to define the potential educational impact of current and future apps. We build upon decades of work on the Science of Learning, which has examined how children learn best. From this work, we abstract a set of principles for two ultimate goals. First, we aim to guide researchers, educators, and designers in evidence-based app development. Second, by creating an evidence-based guide, we hope to set a new standard for evaluating and selecting the most effective existing children's apps. In short, we will show how the design and use of educational apps aligns with known processes of children's learning and development and offer a framework that can be used by parents and designers alike. Apps designed to promote active, engaged, meaningful, and socially interactive learning-four "pillars" of learning-within the context of a supported learning goal are considered educational.
592 citations
TL;DR: Wide variation in the quality of nonverbal and verbal interactions at 24 months accounted for 27% of the variance in expressive language 1 year later, and indicators of quality were considerably more potent predictors of later language ability than was the quantity of mothers’ words during the interaction or sensitive parenting.
Abstract: The disparity in the amount and quality of language that low-income children hear relative to their more-affluent peers is often referred to as the 30-million-word gap. Here, we expand the literature about this disparity by reporting the relative contributions of the quality of early parent-child communication and the quantity of language input in 60 low-income families. Including both successful and struggling language learners from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development, we noted wide variation in the quality of nonverbal and verbal interactions (symbol-infused joint engagement, routines and rituals, fluent and connected communication) at 24 months, which accounted for 27% of the variance in expressive language 1 year later. These indicators of quality were considerably more potent predictors of later language ability than was the quantity of mothers’ words during the interaction or sensitive parenting. Bridging the word gap requires ...
526 citations
TL;DR: Clinically important posttraumatic stress disorder symptoms occurred in one fifth of critical illness survivors at 1-year follow-up, with higher prevalence in those who had comorbid psychopathology, received benzodiazepines, and had early memories of frightening ICU experiences.
Abstract: Objective:To conduct a systematic review and metaanalysis of the prevalence, risk factors, and prevention/treatment strategies for posttraumatic stress disorder symptoms in critical illness survivors.Data Sources:PubMed, Embase, CINAHL, PsycINFO, and Cochrane Library from inception through March 5,
500 citations
TL;DR: In this article, the results from six different IceCube searches for astrophysical neutrinos in a maximum-likelihood analysis are combined, and the combined event sample features high-statistics samples of shower-like and track-like events.
Abstract: Evidence for an extraterrestrial flux of high-energy neutrinos has now been found in multiple searches with the IceCube detector. The first solid evidence was provided by a search for neutrino events with deposited energies greater than or similar to 30 TeV and interaction vertices inside the instrumented volume. Recent analyses suggest that the extraterrestrial flux extends to lower energies and is also visible with throughgoing, nu(mu)-induced tracks from the Northern Hemisphere. Here, we combine the results from six different IceCube searches for astrophysical neutrinos in a maximum-likelihood analysis. The combined event sample features high-statistics samples of shower-like and track-like events. The data are fit in up to three observables: energy, zenith angle, and event topology. Assuming the astrophysical neutrino flux to be isotropic and to consist of equal flavors at Earth, the all-flavor spectrum with neutrino energies between 25 TeV and 2.8 PeV is well described by an unbroken power law with best-fit spectral index -2.50 +/- 0.09 and a flux at 100 TeV of (6.7(-1.2)(+1.1)) x 10(-18) GeV-1 s(-1) sr(-1) cm(-2). Under the same assumptions, an unbroken power law with index -2 is disfavored with a significance of 3.8 sigma (p = 0.0066%) with respect to the best fit. This significance is reduced to 2.1 sigma (p = 1.7%) if instead we compare the best fit to a spectrum with index -2 that has an exponential cut-off at high energies. Allowing the electron-neutrino flux to deviate from the other two flavors, we find a nu(e) fraction of 0.18 +/- 0.11 at Earth. The sole production of electron neutrinos, which would be characteristic of neutron-decay-dominated sources, is rejected with a significance of 3.6 sigma ( p = 0.014%).
Katholieke Universiteit Leuven1, University of Delaware2, University of California, Los Angeles3, University of Texas Southwestern Medical Center4, Case Western Reserve University5, Broad Institute6, Université catholique de Louvain7, University of Cambridge8, Cancer Research UK9, University of Luxembourg10, McGill University11, University of Glasgow12, Yale University13, Harvard University14, Cornell University15, Michigan State University16, University of California, San Diego17, University of Arizona18, University of Rochester19, Princeton University20, Medical Research Council21, ETH Zurich22, Massachusetts Institute of Technology23, University of Birmingham24, Saarland University25, Vanderbilt University26
TL;DR: Key issues in interpreting (13)C metabolite labeling patterns are reviewed, with the goal of drawing accurate conclusions from steady state and dynamic stable isotopic tracer experiments.
TL;DR: The intracellular signaling cascades involved in the apoptotic response to PTT using cells harboring photothermal transducing nanoprisms are revealed and photothermally induced apoptosis is discussed as a potential therapeutic pathway.
Abstract: Photothermal therapy (PTT) utilizes nanoparticles embedded within tumors as exogenous energy absorbers to convert laser light energy into heat to ablate cancer cells. While PTT is a promising alternative to conventional cancer therapy, under certain irradiation conditions, it can produce cellular necrosis, and this necrosis may lead to pro-inflammatory responses that are detrimental to treatment success. Recent studies have shown that PTT can be modulated to induce apoptosis rather than necrosis, which is appealing since apoptosis discourages an inflammatory response. In this issue of ACS Nano, del Pino, Pardo, de la Fuente, and colleagues reveal the intracellular signaling cascades involved in the apoptotic response to PTT using cells harboring photothermal transducing nanoprisms. In this Perspective, we present an overview of nanoparticle-mediated PTT and discuss photothermally induced apoptosis as a potential therapeutic pathway.
TL;DR: It is shown that transcript abundance correlates with cellular volume at the single-cell level due to increased global transcription in larger cells, and a separate mechanism for gene dosage compensation after DNA replication that enables proper transcriptional output during early and late S phase is revealed.
TL;DR: In this article, the authors combine experimental and computational efforts to explore the electrocatalytic reaction mechanism of CO2 reduction on nanostructured Ag catalyst surfaces in an aqueous electrolyte.
Abstract: Electroreduction of CO2 in a highly selective and efficient manner is a crucial step toward CO2 utilization. Nanostructured Ag catalysts have been found to be effective candidates for CO2 to CO conversion. In this report, we combine experimental and computational efforts to explore the electrocatalytic reaction mechanism of CO2 reduction on nanostructured Ag catalyst surfaces in an aqueous electrolyte. In contrast to bulk Ag catalysts, both nanoparticle and nanoporous Ag catalysts show enhanced ability to reduce the activation energy of the CO2 to COOHads intermediate step through the low-coordinated Ag surface atoms, resulting in a reaction mechanism involving a fast first electron and proton transfer followed by a slow second proton transfer as the rate-limiting step.
TL;DR: The rapid development of MnO 2 -based nanocomposites for high-performance supercapacitors in recent years has been reviewed in terms of the charge storage mechanism, materials science, and smart cell assembly as discussed by the authors.
TL;DR: It is reported that a hierarchical nanoporous copper-titanium bimetallic electrocatalyst is able to produce hydrogen from water under a mild overpotential at more than twice the rate of state-of-the-art carbon-supported platinum catalyst.
Abstract: A robust and efficient non-precious metal catalyst for hydrogen evolution reaction is one of the key components for carbon dioxide-free hydrogen production. Here we report that a hierarchical nanoporous copper-titanium bimetallic electrocatalyst is able to produce hydrogen from water under a mild overpotential at more than twice the rate of state-of-the-art carbon-supported platinum catalyst. Although both copper and titanium are known to be poor hydrogen evolution catalysts, the combination of these two elements creates unique copper-copper-titanium hollow sites, which have a hydrogen-binding energy very similar to that of platinum, resulting in an exceptional hydrogen evolution activity. In addition, the hierarchical porosity of the nanoporous copper-titanium catalyst also contributes to its high hydrogen evolution activity, because it provides a large-surface area for electrocatalytic hydrogen evolution, and improves the mass transport properties. Moreover, the catalyst is self-supported, eliminating the overpotential associated with the catalyst/support interface.
TL;DR: This paper devise an efficient hierarchical codebook by jointly exploiting sub-array and deactivation (turning-off) antenna processing techniques, where closed-form expressions are provided to generate the codebook.
Abstract: In millimeter-wave communication, large antenna arrays are required to achieve high power gain by steering towards each other with narrow beams, which poses the problem to efficiently search the best beam direction in the angle domain at both Tx and Rx sides. As the exhaustive search is time consuming, hierarchical search has been widely accepted to reduce the complexity, and its performance is highly dependent on the codebook design. In this paper, we propose two basic criteria for the hierarchical codebook design, and devise an efficient hierarchical codebook by jointly exploiting sub-array and deactivation (turning-off) antenna processing techniques, where closed-form expressions are provided to generate the codebook. Performance evaluations are conducted under different system and channel models. Results show superiority of the proposed codebook over the existing alternatives.
TL;DR: In this article, the authors used electrical detection, in combination with microwave transmission, to investigate both resonant and nonresonant magnon-photon coupling at room temperature, and found that the coupling features such as modes anticrossing, linewidth evolution, peculiar line shape and resonance broadening are systematically measured and consistently analyzed by a theoretical model set on the foundation of classical electrodynamic coupling.
Abstract: We use electrical detection, in combination with microwave transmission, to investigate both resonant and nonresonant magnon-photon coupling at room temperature Spin pumping in a dynamically coupled magnon-photon system is found to be distinctly different from previous experiments Characteristic coupling features such as modes anticrossing, linewidth evolution, peculiar line shape, and resonance broadening are systematically measured and consistently analyzed by a theoretical model set on the foundation of classical electrodynamic coupling Our experimental and theoretical approach paves the way for pursuing microwave coherent manipulation of pure spin current via the combination of spin pumping and magnon-photon coupling
TL;DR: In this paper, three key major components of nonaqueous RFBs: organic solvents, supporting electrolytes, and redox pairs are selectively focused and discussed, with emphasis on providing an overview of those components and highlighting the relationship between structure and properties.
Abstract: As members of the redox-flow battery (RFB) family, nonaqueous RFBs can offer a wide range of working temperature, high cell voltage, and potentially high energy density. These key features make nonaqueous RFBs an important complement of aqueous RFBs, broadening the spectrum of RFB applications. The development of nonaqueous RFBs is still at its early research stage and great challenges remain to be addressed before their successful use for practical applications. As such, it is essential to understand the major components in order to advance the nonaqueous RFB technology. In this perspective, three key major components of nonaqueous RFBs: organic solvents, supporting electrolytes, and redox pairs are selectively focused and discussed, with emphasis on providing an overview of those components and on highlighting the relationship between structure and properties. Urgent challenges are also discussed. To advance nonaqueous RFBs, the understanding of both components and systems is critically needed and it calls for inter-disciplinary collaborations across expertise including electrochemistry, organic chemistry, physical chemistry, cell design, and system engineering. In order to demonstrate the key features of nonaqueous RFBs, herein we also present an example of designing a 4.5 V ultrahigh-voltage nonaqueous RFB by combining a BP/BP˙− redox pair and an OFN˙+/OFN redox pair.
Qatar Airways1, La Trobe University2, University College Dublin3, University of Warwick4, University of British Columbia5, Australian Institute of Sport6, University of Sydney7, University of Eastern Finland8, University of Pittsburgh9, University of Leeds10, University of Melbourne11, Leeds Beckett University12, Hvidovre Hospital13, University of Delaware14, Nicholas Institute of Sports Medicine and Athletic Trauma15, Erasmus University Rotterdam16
TL;DR: The Doha agreement meeting on terminology and definitions in groin pain in athletes reached a consensus on a clinically based taxonomy using three major categories based on history and physical examination to categorise athletes, making it simple and suitable for both clinical practice and research.
Abstract: Background Heterogeneous taxonomy of groin injuries in athletes adds confusion to this complicated area. Aim The ‘Doha agreement meeting on terminology and definitions in groin pain in athletes’ was convened to attempt to resolve this problem. Our aim was to agree on a standard terminology, along with accompanying definitions. Methods A one-day agreement meeting was held on 4 November 2014. Twenty-four international experts from 14 different countries participated. Systematic reviews were performed to give an up-to-date synthesis of the current evidence on major topics concerning groin pain in athletes. All members participated in a Delphi questionnaire prior to the meeting. Results Unanimous agreement was reached on the following terminology. The classification system has three major subheadings of groin pain in athletes: 1. Defined clinical entities for groin pain: Adductor-related, iliopsoas-related, inguinal-related and pubic-related groin pain. 2. Hip-related groin pain. 3. Other causes of groin pain in athletes. The definitions are included in this paper. Conclusions The Doha agreement meeting on terminology and definitions in groin pain in athletes reached a consensus on a clinically based taxonomy using three major categories. These definitions and terminology are based on history and physical examination to categorise athletes, making it simple and suitable for both clinical practice and research.
TL;DR: In this paper, a nanostructured Zn dendrite catalyst was used to reduce CO2 to CO in an aqueous bicarbonate electrolyte with greatly enhanced properties.
Abstract: Electrochemical CO2 reduction is a key reaction for CO2 conversion to valuable fuels and chemicals. Because of the high stability of the CO2 molecule, a catalyst is typically required to minimize the energy input and improve reaction rates needed for device level commercialization. In this paper, we report a nanostructured Zn dendrite catalyst that is able to electrochemically reduce CO2 to CO in an aqueous bicarbonate electrolyte with greatly enhanced properties. The catalytic activity is over an order of magnitude higher than that of bulk Zn counterparts, with a CO faradaic efficiency around 3-fold higher. The stability of the Zn electrode under realistic CO2 electrolysis conditions was explored using scanning electron microscopy and in situ/operando X-ray absorption spectroscopy techniques. The results clearly demonstrate that nanostructured and bulk Zn catalysts are structurally stable at potentials more negative than −0.7 V versus RHE, whereas severe chemical oxidation occurs at more positive potentials.
TL;DR: In this paper, the authors presented the results of a search for neutrino interactions inside IceCube's instrumented volume between 1 TeV and 1 PeV in 641 days of data taken from 2010-2012, and showed that neutrinos from the southern sky below 10 TeV for the first time, far below the threshold of the previous high-energy analysis.
Abstract: The IceCube Neutrino Observatory was designed primarily to search for high-energy (TeV-PeV) neutLrinos produced in distant astrophysical objects. A search for. greater than or similar to 100 TeV neutrinos interacting inside the instrumented volume has recently provided evidence for an isotropic flux of such neutrinos. At lower energies, IceCube collects large numbers of neutrinos from the weak decays of mesons in cosmic-ray air showers. Here we present the results of a search for neutrino interactions inside IceCube's instrumented volume between 1 TeV and 1 PeV in 641 days of data taken from 2010-2012, lowering the energy threshold for neutrinos from the southern sky below 10 TeV for the first time, far below the threshold of the previous high-energy analysis. Astrophysical neutrinos remain the dominant component in the southern sky down to a deposited energy of 10 TeV. From these data we derive new constraints on the diffuse astrophysical neutrino spectrum, Phi(v) = 2.06(-0.3)(+0.4) x 10(-18) (E-v = 10(5) GeV)-2.46 +/- 0.12GeV-1 cm(-2) sr(-1) s(-1) for 25 TeV < E-v < 1.4 PeV, as well as the strongest upper limit yet on the flux of neutrinos from charmed-meson decay in the atmosphere, 1.52 times the benchmark theoretical prediction used in previous IceCube results at 90% confidence.
TL;DR: In this paper, a data sample of approximately 35 000 muon neutrinos from the Northern sky is extracted from data taken during 659.5 days of live time recorded between May 2010 and May 2012.
Abstract: Results from the IceCube Neutrino Observatory have recently provided compelling evidence for the existence of a high energy astrophysical neutrino flux utilizing a dominantly Southern Hemisphere data set consisting primarily of nu(e) and nu(tau) charged-current and neutral-current ( cascade) neutrino interactions. In the analysis presented here, a data sample of approximately 35 000 muon neutrinos from the Northern sky is extracted from data taken during 659.5 days of live time recorded between May 2010 and May 2012. While this sample is composed primarily of neutrinos produced by cosmic ray interactions in Earth's atmosphere, the highest energy events are inconsistent with a hypothesis of solely terrestrial origin at 3.7 sigma significance. These neutrinos can, however, be explained by an astrophysical flux per neutrino flavor at a level of Phi(E-nu) = 9.9(-3.4)(+3.9) x 10(-19) GeV-1 cm(-2) sr(-1) s(-1) (E-nu/100 TeV)(-2), consistent with IceCube's Southern-Hemisphere-dominated result. Additionally, a fit for an astrophysical flux with an arbitrary spectral index is performed. We find a spectral index of 2.2(-0.2)(+0.2), which is also in good agreement with the Southern Hemisphere result.
18 Dec 2015
TL;DR: The progress in cell based therapies that utilize Mesenchymal Stem Cell (MSC) infusion for cartilage repair may lead to new therapeutics in the long term, however, many questions are unanswered such as the efficacy of MSCs usage in therapy.
Abstract: Articular cartilage (AC) covers the diarthrodial joints and is responsible for the mechanical distribution of loads across the joints. The majority of its structure and function is controlled by chondrocytes that regulate Extracellular Matrix (ECM) turnover and maintain tissue homeostasis. Imbalance in their function leads to degenerative diseases like Osteoarthritis (OA). OA is characterized by cartilage degradation, osteophyte formation and stiffening of joints. Cartilage degeneration is a consequence of chondrocyte hypertrophy along with the expression of proteolytic enzymes. Matrix Metalloproteinases (MMPs) and A Disintegrin and Metalloproteinase with Thrombospondin Motifs (ADAMTS) are an example of these enzymes that degrade the ECM. Signaling cascades involved in limb patterning and cartilage repair play a role in OA progression. However, the regulation of these remains to be elucidated. Further the role of stem cells and mature chondrocytes in OA progression is unclear. The progress in cell based therapies that utilize Mesenchymal Stem Cell (MSC) infusion for cartilage repair may lead to new therapeutics in the long term. However, many questions are unanswered such as the efficacy of MSCs usage in therapy. This review focuses on the role of chondrocytes in cartilage formation and the progression of OA. Moreover, it summarizes possible alternative therapeutic approaches using MSC infusion for cartilage restoration.
TL;DR: Three-dimensional (3D) topological insulators are known for their strong spin-orbit coupling (SOC) and the existence of spin-textured surface states that might be potentially exploited for "topological spintronics."
Abstract: Three-dimensional (3D) topological insulators are known for their strong spin-orbit coupling (SOC) and the existence of spin-textured surface states that might be potentially exploited for "topological spintronics." Here, we use spin pumping and the inverse spin Hall effect to demonstrate successful spin injection at room temperature from a metallic ferromagnet (CoFeB) into the prototypical 3D topological insulator Bi2Se3. The spin pumping process, driven by the magnetization dynamics of the metallic ferromagnet, introduces a spin current into the topological insulator layer, resulting in a broadening of the ferromagnetic resonance (FMR) line width. Theoretical modeling of spin pumping through the surface of Bi2Se3, as well as of the measured angular dependence of spin-charge conversion signal, suggests that pumped spin current is first greatly enhanced by the surface SOC and then converted into a dc-voltage signal primarily by the inverse spin Hall effect due to SOC of the bulk of Bi2Se3. We find that the FMR line width broadens significantly (more than a factor of 5) and we deduce a spin Hall angle as large as 0.43 in the Bi2Se3 layer.
Science for Life Laboratory1, Swedish University of Agricultural Sciences2, University of Edinburgh3, University of Adelaide4, AgResearch5, University of Arizona6, United States Department of Agriculture7, European Bioinformatics Institute8, Livestock Improvement Corporation9, Commonwealth Scientific and Industrial Research Organisation10, University of Missouri11, Institut national de la recherche agronomique12, Wageningen University and Research Centre13, La Trobe University14, Department of Environment and Primary Industries15, Cooperative Research Centre16, Jiangxi Agricultural University17, University of Wisconsin-Madison18, Seoul National University19, University of Queensland20, Mississippi State University21, University of Alberta22, Iowa State University23, University of Delaware24, Washington State University25, Huazhong Agricultural University26, University of California, Davis27
TL;DR: The organization of a nascent international effort, the Functional Annotation of Animal Genomes (FAANG) project, whose aim is to produce comprehensive maps of functional elements in the genomes of domesticated animal species is described.
Abstract: We describe the organization of a nascent international effort, the Functional Annotation of Animal Genomes (FAANG) project, whose aim is to produce comprehensive maps of functional elements in the genomes of domesticated animal species.
TL;DR: An asymmetric configuration is applied to the WSS, achieving tripled energy density and doubled power density compared to its asymmetric counterpart while accomplishing stretchability of up to 100% through the prestrainning-then-buckling approach.
Abstract: While the emerging wire-shaped supercapacitors (WSS) have been demonstrated as promising energy storage devices to be implemented in smart textiles, challenges in achieving the combination of both high mechanical stretchability and excellent electrochemical performance still exist. Here, an asymmetric configuration is applied to the WSS, extending the potential window from 0.8 to 1.5 V, achieving tripled energy density and doubled power density compared to its asymmetric counterpart while accomplishing stretchability of up to 100% through the prestrainning-then-buckling approach. The stretchable asymmetric WSS constituted of MnO2/CNT hybrid fiber positive electrode, aerogel CNT fiber negative electrode and KOH-PVA electrolyte possesses a high specific capacitance of around 157.53 μF cm–1 at 50 mV s–1 and a high energy density varying from 17.26 to 46.59 nWh cm–1 with the corresponding power density changing from 7.63 to 61.55 μW cm–1. Remarkably, a cyclic tensile strain of up to 100% exerts negligible eff...
TL;DR: Klemas et al. as discussed by the authors presented an overview of UAVs for coastal and environmental remote sensing from unmanned aerial vehicles (UAVs), including various configurations of unmanned aircraft, multi-rotor helicopters (e.g., quadcopters), and balloons/blimps of different sizes and shapes.
Abstract: Klemas, V.V., 2015. Coastal and environmental remote sensing from unmanned aerial vehicles: An overview. Unmanned aerial vehicles (UAVs) offer a viable alternative to conventional platforms for acquiring high-resolution remote-sensing data at lower cost and increased operational flexibility. UAVs include various configurations of unmanned aircraft, multirotor helicopters (e.g., quadcopters), and balloons/blimps of different sizes and shapes. Quadcopters and balloons fill a gap between satellites and aircraft when a stationary monitoring platform is needed for relatively long-term observation of an area. UAVs have advanced designs to carry small payloads and integrated flight control systems, giving them semiautonomous or fully autonomous flight capabilities. Miniaturized sensors are being developed/adapted for UAV payloads, including hyperspectral imagers, LIDAR, synthetic aperture radar, and thermal infrared sensors. UAVs are now used for a wide range of environmental applications, such as coast...
TL;DR: Simulation results show that the proposed pilot reuse in single cell for massive multiuser multiple-input multiple-output (MIMO) transmission to reduce the pilot overhead provides significant performance gains over the conventional orthogonal training scheme in terms of net spectral efficiency.
Abstract: We propose pilot reuse (PR) in single cell for massive multiuser multiple-input multiple-output (MIMO) transmission to reduce the pilot overhead. For spatially correlated Rayleigh fading channels, we establish a relationship between channel spatial correlations and channel power angle spectrum when the base station antenna number tends to infinity. With this channel model, we show that sum mean square error (MSE) of channel estimation can be minimized provided that channel angle of arrival intervals of the user terminals reusing the pilots are non-overlapping, which shows feasibility of PR over spatially correlated massive MIMO channels with constrained channel angular spreads. Regarding that channel estimation performance might degrade due to PR, we also develop the closed-form robust multiuser uplink receiver and downlink precoder that minimize sum MSE of signal detection, and reveal a duality between them. Subsequently, we investigate pilot scheduling, which determines the PR pattern, under two minimum MSE related criteria, and propose a low complexity pilot scheduling algorithm which relies on the channel statistics only. Simulation results show that the proposed PR scheme provides significant performance gains over the conventional orthogonal training scheme in terms of net spectral efficiency.