Recent Submissions

  • Runtime Abstraction for Autonomous Adaptive Systems on Reconfigurable Hardware

    Bucknall, Alex R.; Fahmy, Suhaib A. (IEEE, 2021-02-01) [Conference Paper]
    Autonomous systems increasingly rely on on-board computation to avoid the latency overheads of offloading to more powerful remote computing. This requires the integration of hardware accelerators to handle the complex computations demanded by date-intensive sensors. FPGAs offer hardware acceleration with ample flexibility and interfacing capabilities when paired with general purpose processors, with the ability to reconfigure at runtime using partial reconfiguration. Managing dynamic hardware is complex and has been left to designers to address in an ad-hoc manner without first-class integration in autonomous software frameworks. This paper presents an abstracted runtime for managing adaptation of FPGA accelerators, including partial reconfiguration and parametric changes, that presents as a typical interface used in autonomous software systems. We present a demonstration using the Robot Operating System (ROS), showing negligible latency overhead as a result of the abstraction.
  • Heat stress destabilizes symbiotic nutrient cycling in corals

    Rädecker, Nils; Pogoreutz, Claudia; Gegner, Hagen; Cardenas, Anny; Roth, Florian; Bougoure, Jeremy; Guagliardo, Paul; Wild, Christian; Pernice, Mathieu; Raina, Jean-Baptiste; Meibom, Anders; Voolstra, Christian R. (Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, 2021-01-26) [Article]
    Recurrent mass bleaching events are pushing coral reefs worldwide to the brink of ecological collapse. While the symptoms and consequences of this breakdown of the coral–algal symbiosis have been extensively characterized, our understanding of the underlying causes remains incomplete. Here, we investigated the nutrient fluxes and the physiological as well as molecular responses of the widespread coral Stylophora pistillata to heat stress prior to the onset of bleaching to identify processes involved in the breakdown of the coral–algal symbiosis. We show that altered nutrient cycling during heat stress is a primary driver of the functional breakdown of the symbiosis. Heat stress increased the metabolic energy demand of the coral host, which was compensated by the catabolic degradation of amino acids. The resulting shift from net uptake to release of ammonium by the coral holobiont subsequently promoted the growth of algal symbionts and retention of photosynthates. Together, these processes form a feedback loop that will gradually lead to the decoupling of carbon translocation from the symbiont to the host. Energy limitation and altered symbiotic nutrient cycling are thus key factors in the early heat stress response, directly contributing to the breakdown of the coral–algal symbiosis. Interpreting the stability of the coral holobiont in light of its metabolic interactions provides a missing link in our understanding of the environmental drivers of bleaching and may ultimately help uncover fundamental processes underpinning the functioning of endosymbioses in general.
  • Improving dust simulations in WRF-Chem v4.1.3 coupled with the GOCART aerosol module

    Ukhov, Alexander; Ahmadov, Ravan; Grell, Georg; Stenchikov, Georgiy L. (Geoscientific Model Development, Copernicus GmbH, 2021-01-25) [Article]
    Abstract. In this paper, we rectify inconsistencies that emerge in the Weather Research and Forecasting model with chemistry (WRF-Chem) v3.2 code when using the Goddard Chemistry Aerosol Radiation and Transport (GOCART) aerosol module. These inconsistencies have been reported, and corrections have been implemented in WRF-Chem v4.1.3. Here, we use a WRF-Chem experimental setup configured over the Middle East (ME) to estimate the effects of these inconsistencies. Firstly, we show that the old version underestimates the PM2.5 diagnostic output by 7 % and overestimates PM10 by 5 % in comparison with the corrected one. Secondly, we demonstrate that submicron dust particles' contribution was incorrectly accounted for in the calculation of optical properties. Therefore, aerosol optical depth (AOD) in the old version was 25 %–30 % less than in the corrected one. Thirdly, we show that the gravitational settling procedure, in comparison with the corrected version, caused higher dust column loadings by 4 %–6 %, PM10 surface concentrations by 2 %–4 %, and mass of the gravitationally settled dust by 5 %–10 %. The cumulative effect of the found inconsistencies led to the significantly higher dust content in the atmosphere in comparison with the corrected WRF-Chem version. Our results explain why in many WRF-Chem simulations PM10 concentrations were exaggerated. We present the methodology for calculating diagnostics we used to estimate the impacts of introduced code modifications. We share the developed Merra2BC interpolator, which allows processing Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2) output for constructing initial and boundary conditions for chemical species and aerosols.
  • Perovskite Single-Crystal Solar Cells: Going Forward

    Turedi, Bekir; Yeddu, Vishal; Zheng, Xiaopeng; Kim, Do Young; Bakr, Osman; Saidaminov, Makhsud I. (ACS Energy Letters, American Chemical Society (ACS), 2021-01-25) [Article]
    Most efficient perovskite solar cells are based on polycrystalline thin films; however, substantial structural disorder and defective grain boundaries place a limit on their performance. Perovskite single crystals are free of grain boundaries, leading to significantly low defect densities, and thus hold promise for high-efficiency photovoltaics. However, the surfaces of perovskite single crystals present a major performance bottleneck because they possess a higher density of traps than the bulk. Hence, it is crucial to understand and control the surface trap population to fully exploit perovskite single crystals. This Perspective highlights the importance of surface-trap management in unleashing the potential of perovskite single-crystal photovoltaics and discusses strategies to take this technology beyond the proof-of-concept stage.
  • Lycopene β-cyclase expression influences plant physiology, development and metabolism in tobacco plants

    Kossler, Stella; Armarego-Marriott, Tegan; Tarkowska, Danuse; Tureckova, Veronika; Agrawal, Shreya; Mi, Jianing; Perez da Sousa, Leonardo; Aurel Schottler, Mark; Schadach, Anne; Frohlich, Anja; Bock, Ralph; Al-Babili, Salim; Ruf, Stephanie; Sampathkumar, Arun; Moreno, Juan C (Journal of Experimental Botany, Oxford University Press (OUP), 2021-01-23) [Article]
    Abstract Carotenoids are important isoprenoids produced in the plastids of photosynthetic organisms that play key roles in photoprotection and antioxidative processes. β-carotene is generated from lycopene by the lycopene β-cyclase (LCYB). Previously, we demonstrated that the introduction of the Daucus carota (carrot) DcLCYB1 gene into tobacco (cultivar Xanthi) resulted in increased levels of abscisic acid (ABA) and especially gibberellins (GAs), resulting in increased plant yield. In order to understand this phenomenon prior exporting this genetic strategy to crops, we generated tobacco (cultivar Petit Havana) mutants that exhibited a wide range of LCYB expression. Transplastomic plants expressing DcLCYB1 at high levels showed a wild-type-like growth, even though their pigment content was increased, and their leaf GA content was reduced. RNAi NtLCYB lines showed different reductions in NtLCYB transcript abundance, correlating with reduced pigment content and plant variegation. Photosynthesis (leaf absorptance, Fv/Fm, and ETRII) and plant growth were impaired. Remarkably, drastic changes in phytohormone content also occurred in the RNAi lines. However, external application of phytohormones was not sufficient to rescue their phenotypes, suggesting that altered photosynthetic efficiency might be another important factor explaining their reduced biomass. These results show that LCYB expression influences plant biomass by different mechanisms and suggests thresholds for LCYB expression levels that might be beneficial/detrimental for plant growth.
  • Binder-Free Construction of a Methanol Tolerant Pt/TiO2/Carbon Paper Anode by Atomic Layer Deposition

    Ballai, Gergő; Gyenes, Tamás; Haspel, Henrik; Vásárhelyi, Lívia; Szenti, Imre; Sebők, Dániel; Kónya, Z.; Kukovecz, Ákos (Catalysts, MDPI AG, 2021-01-22) [Article]
    Direct liquid fuel cells are very appealing alternatives for fighting climate change, particularly in the field of personal mobility solutions. This is especially true for direct methanol fuel cells (DMFCs) that use and burn safe fuels that are readily available from sustainable sources using well-established C1 chemistry. However, DMFCs also have some serious competitive disadvantages, like the high cost of the noble metal catalysts, the difficulties of the catalyst application, and the poisoning of the catalyst due to carbon monoxide formation. Here we demonstrate that depositing platinum on TiO2 by atomic layer deposition (ALD) is an easy, reproducible method for the synthesis of TiO2-supported platinum catalyst for methanol oxidation with superior anti-poisoning properties.
  • Microseismic Location Error Due to Eikonal Traveltime Calculation

    Alexandrov, Dmitry; Waheed, Umair bin; Eisner, Leo (Applied Sciences, MDPI AG, 2021-01-22) [Article]
    The accuracy of computed traveltimes in a velocity model plays a crucial role in localization of microseismic events. The conventional approach usually utilizes robust fast sweeping or fast marching methods to solve the eikonal equation numerically with a finite-difference scheme. These methods introduce traveltime errors that strongly depend on the direction of wave propagation. Such error results in moveout changes of the computed traveltimes and introduces significant location bias. The issue can be addressed by using a finite-difference scheme to solve the factored eikonal equation. This equation yields significantly more accurate traveltimes and therefore reduces location error, though the traveltimes computed with the factored eikonal equation still contain small errors with systematic bias. Alternatively, the traveltimes can be computed using a physics-informed neural network solver, which yields more randomized traveltimes and resulting location errors.
  • BAlN for III-nitride UV light-emitting diodes: undoped electron blocking layer

    Gu, Wen; Lu, Yi; Lin, Rongyu; Guo, Wenzhe; Zhang, Zi-hui; Ryou, Jae-Hyun; Yan, Jianchang; Wang, Junxi; Li, Jinmin; Li, Xiaohang (Journal of Physics D: Applied Physics, IOP Publishing, 2021-01-22) [Article]
    The undoped BAlN electron-blocking layer (EBL) is investigated to replace the conventional AlGaN EBL in light-emitting diodes (LEDs). Numerical studies of the impact of variously doped EBLs on the output characteristics of LEDs demonstrate that the LED performance shows heavy dependence on the p-doping level in the case of the AlGaN EBL, while it shows less dependence on the p-doping level for the BAlN EBL. As a result, we propose an undoped BAlN EBL for LEDs to avoid the p-doping issues, which a major technical challenge in the AlGaN EBL. Without doping, the proposed BAlN EBL structure still possesses a superior capacity in blocking electrons and improving hole injection compared with the AlGaN EBL having high doping. Compared with the Al0.3Ga0.7N EBL with a doping concentration of 1×1020 /cm3, the undoped BAlN EBL LED still shows lower droop (only 5%), compatible internal quantum efficiency (2% enhancement), and optical output power (6% enhancement). This study provides a feasible route to addressing electron leakage and insufficient hole injection issues when designing UV LED structures.
  • Group-III-nitride and halide-perovskite semiconductor gain media for amplified spontaneous emission and lasing applications

    Ng, Tien Khee; Holguin Lerma, Jorge Alberto; Kang, Chun Hong; Ashry, Islam; Zhang, Huafan; Bucci, Giada; Ooi, Boon S. (Journal of Physics D: Applied Physics, IOP Publishing, 2021-01-22) [Article]
    Group-III-nitride optical devices are conventionally important for displays and solid-state lighting, and recently have garnered much interest in the field of visible-light communication. While visible-light laser technology has become mature, developing a range of compact, small footprint, high optical power components for the green-yellow gap wavelengths still requires material development and device design breakthroughs, as well as hybrid integration of materials to overcome the limitations of conventional approaches. The present review focuses on the development of laser and amplified spontaneous emission (ASE) devices in the visible wavelength regime using primarily group-III-nitride and halide-perovskite semiconductors, which are at disparate stages of maturity. While the former is well established in the violet-blue-green operating wavelength regime, the latter, which is capable of solution-based processing and wavelength-tunability in the green-yellow-red regime, promises easy heterogeneous integration to form a new class of hybrid semiconductor light emitters. Prospects for the use of perovskite in ASE and lasing applications are discussed in the context of facile fabrication techniques and promising wavelength-tunable light-emitting device applications, as well as the potential integration with group-III-nitride contact and distributed Bragg reflector layers, which is promising as a future research direction. The absence of lattice-matching limitations, and the presence of direct bandgaps and excellent carrier transport in halide-perovskite semiconductors, are both encouraging and thought-provoking for device researchers who seek to explore new possibilities either experimentally or theoretically. These combined properties inspire researchers who seek to examine the suitability of such materials for potential novel electrical injection devices designed for targeted applications related to lasing and operating-wavelength tuning.
  • EMF-Aware Cellular Networks in RIS-Assisted Environments

    Ibraiwish, Hussam; Elzanaty, Ahmed; Al-Badarneh, Yazan H; Alouini, Mohamed-Slim (2021-01-21) [Preprint]
    The dense deployment of the 5th-generation cellular networks (5G) and beyond has triggered health concerns due to the electric and magnetic fields (EMF) exposure. In this paper, we propose minimizing the populations’ exposure to EMF by considering a smart radio environment with a reconfigurable intelligent surface (RIS). We propose a novel algorithm for the RIS phase design that minimizes an exposure index (EI), in terms of the specific absorption rate (SAR), while maintaining a minimum target quality of service (QoS). The proposed algorithm achieves up to 60% and 50% reduction in EI compared to schemes without RISs and with non-optimized RIS, respectively.
  • Multiscale Assembly of [AgS 4 ] Tetrahedrons into Hierarchical Ag–S Networks for Robust Photonic Water

    Wu, Zhennan; Yao, Qiaofeng; Liu, Zhihe; Xu, Hongyi; Guo, Peng; Liu, Lingmei; Han, Yu; Zhang, Kuo; Lu, Zhongyuan; Li, Xuke; Zhang, Jiangwei; Xie, Jianping (Advanced Materials, Wiley, 2021-01-21) [Article]
    There is an urgent need to assemble ultrasmall metal chalcogenides (with atomic precision) into functional materials with the required anisotropy and uniformity, on a micro- or even macroscale. Here, a delicate yet simple chemistry is developed to produce a silver-sulfur network microplate with a high monodispersity in size and morphology. Spanning from the atomic, molecular, to nanometer, to micrometer scale, the key structural evolution of the obtained microplates includes 2D confinement growth, edge-sharing growth mode, and thermodynamically driven layer-by-layer stacking, all of which are derived from the [AgS<sub>4</sub> ] tetrahedron unit. The key to such a high hierarchical, complex, and accurate assembly is the dense deprotonated ligand layer on the surface of the microplates, forming an infinite surface with high negative charge density. This feature operates at an orderly distance to allow further hierarchical self-assembly on the microscale to generate columnar assemblies composed of microplate components, thereby endowing the feature of the 1D photonic reflector to water (i.e., photonic water). The reflective color of the resulting photonic water is highly dependent on the thickness of the building blocks (i.e., silver-sulfur microplates), and the coexistent order and fluidity help to form robust photonic water.
  • Broadcast spawning of Pocillopora verrucosa across the eastern and western coast of the central Red Sea

    Bouwmeester, Jessica; Coker, Darren James; Sinclair-Taylor, Tane H.; Berumen, Michael L. (Ecosphere, Wiley, 2021-01-21) [Article]
    Coral spawning is a fundamental process in the preservation of coral reef systems. However, reproductive information is still rare for many coral species and across a number of locations. No reproductive information is yet available from the western coast of the central and southern Red Sea. We document here the daytime spawning of Pocillopora verrucosa across the two coasts of the central Red Sea, in Saudi Arabia on the eastern side and in Sudan on the western side. In both sites, P. verrucosa released its gametes in the morning, 1–2 d before the new moon, within a 25-day window between mid-May and mid-June, matching other known observations from the east coast of the central Red Sea. Spawning followed a period of rapidly changing sea surface temperature. We here propose that given the reproductive synchrony of P. verrucosa across both coasts, the timing of coral spawning from other species is likely to be similar as well.
  • Structure–property correlations and conductivity of mixed boro-tellurite glass formers

    El-Egili, K.; El Agammy, E. F.; Al-Zaibani, M.; Jaremko, Mariusz; Emwas, Abdul-Hamid M. (Applied Physics A, Springer Science and Business Media LLC, 2021-01-20) [Article]
    Glasses of the formula 30Ag2O⋅xB2O3⋅(70–x)TeO2 (0 ≤ x ≤ 70 mol%) were prepared under normal conditions, followed by FTIR spectroscopy, density, molar volume, XRD, SEM, and dc conductivity studies. FTIR spectra were deconvoluted to track the change in the fraction of the TeO4 and BO4 units. FTIR results showed a linear decrease in both fractions of the N4Te and N4B units with B2O3 content, while BO4 and BO3 units increased with nearly equal values up to 40 mol% B2O3. The rate of increasing BO3 was greater than BO4 units for glasses with > 40 mol% B2O3. Density linearly decreased, whereas molar volume increased when replacing TeO2 with B2O3. XRD and SEM revealed formation of AgTeO3 and AgBO3 micro-crystallites depending on the concentration of B2O3. The introduction of B2O3 into the Ag2O–TeO2 network caused an increase in the conductivity up to 50 mol%, which decreased for further additions of B2O3 content. Finally, the conductivity of the studied glasses was more strongly affected by the pre-exponential factor rather than the activation energy.
  • Protein-protein interactions decoys datasets for machine learning algorithm development

    Barradas Bautista, Didier; Almajed, Ali; Cavallo, Luigi; Kalnis, Panos; Oliva, Romina (KAUST Research Repository, 2021-01-20) [Dataset]
    This is the most complete and diverse protein docking decoys set derived from the Benchmark5, Scorers_set. We used three different rigid-body docking programs to generate the decoys for the Bechmark5. We analyzed all docking decoys with more than 150 different scoring functions from different sources ( CCharppi, FreeSASA, CIPS, CONSRANK). We provide a balanced and unbalanced version of the data. This balanced data is intended for the training and test of machine learning algorithms. the unbalanced data is provided to simulated the real-world scenario. We also provide a set of rigid-body docking decoys from Interactome3D that spans 1391 interactions. We obtained the labels for this set using a weakly-supervised approach we called hAIkal. We used this data to augment the train data and improve machine learning classifiers.
  • Electrolyte-Mediated Stabilization of High-Capacity Micro-Sized Antimony Anodes for Potassium-Ion Batteries

    Zhou, Lin; Cao, Zhen; Zhang, Jiao; Cheng, Hraoran; Liu, Gang; Park, Geon-Tae; Cavallo, Luigi; Wang, Limin; Alshareef, Husam N.; Sun, Yang-Kook; Ming, Jun (Advanced Materials, Wiley, 2021-01-20) [Article]
    Alloying anodes exhibit very high capacity when used in potassium-ion batteries, but their severe capacity fading hinders their practical applications. The failure mechanism has traditionally been attributed to the large volumetric change and/or their fragile solid electrolyte interphase. Herein, it is reported that an antimony (Sb) alloying anode, even in bulk form, can be stabilized readily by electrolyte engineering. The Sb anode delivers an extremely high capacity of 628 and 305 mAh g<sup>-1</sup> at current densities of 100 and 3000 mA g<sup>-1</sup> , respectively, and remains stable for more than 200 cycles. Interestingly, there is no need to do nanostructural engineering and/or carbon modification to achieve this excellent performance. It is shown that the change in K<sup>+</sup> solvation structure, which is tuned by electrolyte composition (i.e., anion, solvent, and concentration), is the main reason for achieving this excellent performance. Moreover, an interfacial model based on the K<sup>+</sup> -solvent-anion complex behavior is presented. The electronegativity of the K<sup>+</sup> -solvent-anion complex, which can be tuned by changing the solvent type and anion species, is used to predict and control electrode stability. The results shed new light on the failure mechanism of alloying anodes, and provide a new guideline for electrolyte design that stabilizes metal-ion batteries using alloying anodes.
  • Protein-protein benchmark5 decoys balanced dataset

    Barradas Bautista, Didier; Oliva, Romina; Cavallo, Luigi (KAUST Research Repository, 2021-01-19) [Dataset]
    This is the most complete and diverse protein docking decoys set derived from the Benchmark5. We used three different rigid-body docking programs to generate the decoys. We analyzed these docking decoys with more than 150 different scoring functions from different sources ( CCharppi, FreeSASA, CIPS, CONSRANK). This version of the dataset is balanced with the raw values from the scoring functions. This data is intended for the training of Machine learning algorithms.
  • Wide range tunable bandgap and composition β-phase (AlGa)2O3 thin film by thermal annealing

    Liao, Che-Hao; Li, Kuang-Hui; Torres Castanedo, Carlos Gerardo; Zhang, Guozheng; Li, Xiaohang (Applied Physics Letters, AIP Publishing, 2021-01-18) [Article]
    We have demonstrated wide bandgap and composition range b-(AlxGa1x)2O3 thin films by employing thermal annealing of b-Ga2O3/ sapphire templates. With proper annealing conditions at 1000–1500 C, the b-Ga2O3 thin films transformed to the b-(AlxGa1x)2O3 thin films with different bandgaps and compositions due to the Al diffusion from sapphire. Meanwhile, the Ga atoms diffused into sapphire. The interdiffusion process caused an increased film thickness, which was enhanced in proportion to the annealing temperature. It was confirmed by secondary ion mass spectrometry (SIMS) and transmission electron microscopy. Thus, higher temperatures resulted in high Al contents in the b-(AlxGa1x)2O3 films. Also, the SIMS measurements show highly homogeneous Al contents throughout the b-(AlxGa1x)2O3 films annealed at 1200 C and above. Evaluated by x-ray diffraction (XRD), the Al content range of the samples is 0–0.81 for the b-Ga2O3 templates without annealing and with annealing up to 1500 C. Evaluated by UV-Vis spectroscopy, the optical bandgap range of the samples is 4.88–6.38 eV for the b-Ga2O3 templates without annealing and with annealing up to 1400 C, translating to the Al content range of 0–0.72. Moreover, the crystal quality of b-(AlxGa1x)2O3 improved as the Al composition became larger due to higher annealing temperatures. The proposed technique is promising for the preparation of b-(AlxGa1x)2O3 thin films without employing “direct-growth” techniques.
  • Symmetry-dependent field-free switching of perpendicular magnetization

    Liu, Liang; Zhou, Chenghang; Shu, Xinyu; Li, Changjian; Zhao, Tieyang; Lin, Weinan; Deng, Jinyu; Xie, Qidong; Chen, Shaohai; Zhou, Jing; Guo, Rui; Wang, Han; Yu, Jihang; Shi, Shu; Yang, Ping; Pennycook, S. J.; Manchon, Aurelien; Chen, Jingsheng (Nature Nanotechnology, Springer Science and Business Media LLC, 2021-01-18) [Article]
    Modern magnetic-memory technology requires all-electric control of perpendicular magnetization with low energy consumption. While spin–orbit torque (SOT) in heavy metal/ferromagnet (HM/FM) heterostructures1,2,3,4,5 holds promise for applications in magnetic random access memory, until today, it has been limited to the in-plane direction. Such in-plane torque can switch perpendicular magnetization only deterministically with the help of additional symmetry breaking, for example, through the application of an external magnetic field2,4, an interlayer/exchange coupling6,7,8,9 or an asymmetric design10,11,12,13,14. Instead, an out-of-plane SOT15 could directly switch perpendicular magnetization. Here we observe an out-of-plane SOT in an HM/FM bilayer of L11-ordered CuPt/CoPt and demonstrate field-free switching of the perpendicular magnetization of the CoPt layer. The low-symmetry point group (3m1) at the CuPt/CoPt interface gives rise to this spin torque, hereinafter referred to as 3m torque, which strongly depends on the relative orientation of the current flow and the crystal symmetry. We observe a three-fold angular dependence in both the field-free switching and the current-induced out-of-plane effective field. Because of the intrinsic nature of the 3m torque, the field-free switching in CuPt/CoPt shows good endurance in cycling experiments. Experiments involving a wide variety of SOT bilayers with low-symmetry point groups16,17 at the interface may reveal further unconventional spin torques in the future.
  • Paired Ru‒O‒Mo ensemble for efficient and stable alkaline hydrogen evolution reaction

    Li, Huang Jing Wei; Liu, Kang; Fu, Junwei; Chen, Kejun; Yang, Kexin; Lin, Yiyang; Yang, Baopeng; Wang, Qiyou; Pan, Hao; Cai, Zhoujun; Li, Hongmei; Cao, Maoqi; Hu, Junhua; Lu, Ying Rui; Chan, Ting Shan; Cortés, Emiliano; Fratalocchi, Andrea; Liu, Min (Nano Energy, Elsevier BV, 2021-01-18) [Article]
    Electrocatalytic hydrogen evolution reaction (HER) in alkaline media is a promising electrochemical energy conversion strategy. Ruthenium (Ru) is an efficient catalyst with a desirable cost for HER, however, the sluggish H2O dissociation process, due to the low H2O adsorption on its surface, currently hampers the performances of this catalyst in alkaline HER. Herein, we demonstrate that the H2O adsorption improves significantly by the construction of Ru–O–Mo sites. We prepared Ru/MoO2 catalysts with Ru–O–Mo sites through a facile thermal treatment process and assessed the creation of Ru–O–Mo interfaces by transmission electron microscope (TEM) and extended X-ray absorption fine structure (EXAFS). By using Fourier-transform infrared spectroscopy (FTIR) and H2O adsorption tests, we proved Ru–O–Mo sites have tenfold stronger H2O adsorption ability than that of Ru catalyst. The catalysts with Ru–O–Mo sites exhibited a state-of-the-art overpotential of 16 mV at 10 mA cm–2 in 1 M KOH electrolyte, demonstrating a threefold reduction than the previous bests of Ru (59 mV) and commercial Pt (31 mV) catalysts. We proved the stability of these performances over 40 h without decline. These results could open a new path for designing efficient and stable catalysts.
  • Protein Phosphatase 1 regulates atypical chromosome segregation and cell polarity during mitotic and meiotic division in Plasmodium sexual stages

    Zeeshan, Mohammad; Pandey, Rajan; Subudhi, Amit; Ferguson, David J P; Kaur, Gursimran; Rashpa, Ravish; Nugmanova, Raushan; Brady, Declan; Bottrill, Andrew R.; Vaughan, Sue; Brochet, Mathieu; Bollen, Mathieu; Pain, Arnab; Holder, Anthony A.; Guttery, David; Tewari, Rita (Cold Spring Harbor Laboratory, 2021-01-17) [Preprint]
    AbstractPP1 is a conserved eukaryotic serine/threonine phosphatase that regulates many aspects of mitosis and meiosis, often working in concert with other phosphatases, such as CDC14 and CDC25. The proliferative stages of the parasite life cycle include sexual development within the mosquito vector, with male gamete formation characterized by an atypical rapid mitosis, consisting of three rounds of DNA synthesis, successive spindle formation with clustered kinetochores, and a meiotic stage during zygote to ookinete development following fertilization. It is unclear how PP1 is involved in these unusual processes. Using real-time live-cell and ultrastructural imaging, conditional gene knockdown, RNA-seq and proteomic approaches, we show that Plasmodium PP1 is involved in both chromosome segregation during mitotic exit, and establishment of cell polarity during zygote development in the mosquito midgut, suggesting that small molecule inhibitors of PP1 should be explored for blocking parasite transmission.

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