bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-responsivity graphene photodetectors integrated on silicon microring resonators
Authors: Schuler S. , Muench J. E. , Ruocco A. , Balci O. , Thourhout D. van , Sorianello V. , Romagnoli M. , Watanabe K. , Taniguchi T. , Goykhman I. , Ferrari A. C. , Mueller T. 
Published: June 2021

AbstractGraphene integrated photonics provides several advantages over conventional Si photonics. Single layer graphene (SLG) enables fast, broadband, and energy-efficient electro-optic modulators, optical switches and photodetectors (GPDs), and is compatible with any optical waveguide. The last major barrier to SLG-based optical receivers lies in the current GPDs’ low responsivity when compared to conventional PDs. Here we overcome this by integrating a photo-thermoelectric GPD with a Si microring resonator. Under critical coupling, we achieve >90% light absorption in a ~6 μm SLG channel along a Si waveguide. Cavity-enhanced light-matter interactions cause carriers in SLG to reach ~400 K for an input power ~0.6 mW, resulting in a voltage responsivity ~90 V/W, with a receiver sensitivity enabling our GPDs to operate at a 10−9 bit-error rate, on par with mature semiconductor technology, but with a natural generation of a voltage, rather than a current, thus removing the need for transimpedance amplification, with a reduction of energy-per-bit, cost, and foot-print.
Vimentin intermediate filaments stabilize dynamic microtubules by direct interactions
Authors: Schaedel Laura , Lorenz Charlotta , Schepers Anna V. , Klumpp Stefan , Köster Sarah 
Published: June 2021

AbstractThe cytoskeleton determines cell mechanics and lies at the heart of important cellular functions. Growing evidence suggests that the manifold tasks of the cytoskeleton rely on the interactions between its filamentous components—actin filaments, intermediate filaments, and microtubules. However, the nature of these interactions and their impact on cytoskeletal dynamics are largely unknown. Here, we show in a reconstituted in vitro system that vimentin intermediate filaments stabilize microtubules against depolymerization and support microtubule rescue. To understand these stabilizing effects, we directly measure the interaction forces between individual microtubules and vimentin filaments. Combined with numerical simulations, our observations provide detailed insight into the physical nature of the interactions and how they affect microtubule dynamics. Thus, we describe an additional, direct mechanism by which cells establish the fundamental cross talk of cytoskeletal components alongside linker proteins. Moreover, we suggest a strategy to estimate the binding energy of tubulin dimers within the microtubule lattice.
Impact of carbon dioxide removal technologies on deep decarbonization of the electric power sector
Authors: Bistline John E. T. , Blanford Geoffrey J. 
Published: June 2021

AbstractCarbon dioxide removal technologies, such as bioenergy with carbon capture and direct air capture, are valuable for stringent climate targets. Previous work has examined implications of carbon removal, primarily bioenergy-based technologies using integrated assessment models, but not investigated the effects of a portfolio of removal options on power systems in detail. Here, we explore impacts of carbon removal technologies on electric sector investments, costs, and emissions using a detailed capacity planning and dispatch model with hourly resolution. We show that adding carbon removal to a mix of low-carbon generation technologies lowers the costs of deep decarbonization. Changes to system costs and investments from including carbon removal are larger as policy ambition increases, reducing the dependence on technologies like advanced nuclear and long-duration storage. Bioenergy with carbon capture is selected for net-zero electric sector emissions targets, but direct air capture deployment increases as biomass supply costs rise.
Memory effect assisted imaging through multimode optical fibres
Authors: Li Shuhui , Horsley Simon A. R. , Tyc Tomáš , Čižmár Tomáš , Phillips David B. 
Published: June 2021

AbstractWhen light propagates through opaque material, the spatial information it holds becomes scrambled, but not necessarily lost. Two classes of techniques have emerged to recover this information: methods relying on optical memory effects, and transmission matrix (TM) approaches. Here we develop a general framework describing the nature of memory effects in structures of arbitrary geometry. We show how this framework, when combined with wavefront shaping driven by feedback from a guide-star, enables estimation of the TM of any such system. This highlights that guide-star assisted imaging is possible regardless of the type of memory effect a scatterer exhibits. We apply this concept to multimode fibres (MMFs) and identify a ‘quasi-radial’ memory effect. This allows the TM of an MMF to be approximated from only one end - an important step for micro-endoscopy. Our work broadens the applications of memory effects to a range of novel imaging and optical communication scenarios.
Principled approach to the selection of the embedding dimension of networks
Authors: Gu Weiwei , Tandon Aditya , Ahn Yong-Yeol , Radicchi Filippo 
Published: June 2021

AbstractNetwork embedding is a general-purpose machine learning technique that encodes network structure in vector spaces with tunable dimension. Choosing an appropriate embedding dimension – small enough to be efficient and large enough to be effective – is challenging but necessary to generate embeddings applicable to a multitude of tasks. Existing strategies for the selection of the embedding dimension rely on performance maximization in downstream tasks. Here, we propose a principled method such that all structural information of a network is parsimoniously encoded. The method is validated on various embedding algorithms and a large corpus of real-world networks. The embedding dimension selected by our method in real-world networks suggest that efficient encoding in low-dimensional spaces is usually possible.
Coordination of two enhancers drives expression of olfactory trace amine-associated receptors
Authors: Fei Aimei , Wu Wanqing , Tan Longzhi , Tang Cheng , Xu Zhengrong , Huo Xiaona , Bao Hongqiang , Kong Yalei , Johnson Mark , Hartmann Griffin , Talay Mustafa , Yang Cheng , Riegler Clemens , Herrera Kristian J. , Engert Florian , Xie X. Sunney , Barnea Gilad , Liberles Stephen D. , Yang Hui , Li Qian 
Published: June 2021

AbstractOlfactory sensory neurons (OSNs) are functionally defined by their expression of a unique odorant receptor (OR). Mechanisms underlying singular OR expression are well studied, and involve a massive cross-chromosomal enhancer interaction network. Trace amine-associated receptors (TAARs) form a distinct family of olfactory receptors, and here we find that mechanisms regulating Taar gene choice display many unique features. The epigenetic signature of Taar genes in TAAR OSNs is different from that in OR OSNs. We further identify that two TAAR enhancers conserved across placental mammals are absolutely required for expression of the entire Taar gene repertoire. Deletion of either enhancer dramatically decreases the expression probabilities of different Taar genes, while deletion of both enhancers completely eliminates the TAAR OSN populations. In addition, both of the enhancers are sufficient to drive transgene expression in the partially overlapped TAAR OSNs. We also show that the TAAR enhancers operate in cis to regulate Taar gene expression. Our findings reveal a coordinated control of Taar gene choice in OSNs by two remote enhancers, and provide an excellent model to study molecular mechanisms underlying formation of an olfactory subsystem.
Tick extracellular vesicles enable arthropod feeding and promote distinct outcomes of bacterial infection
Authors: Oliva Chávez Adela S. , Wang Xiaowei , Marnin Liron , Archer Nathan K. , Hammond Holly L. , Carroll Erin E. McClure , Shaw Dana K. , Tully Brenden G. , Buskirk Amanda D. , Ford Shelby L. , Butler L. Rainer , Shahi Preeti , Morozova Kateryna , Clement Cristina C. , Lawres Lauren , Neal Anya J. O’ , Mamoun Choukri Ben , Mason Kathleen L. , Hobbs Brandi E. , Scoles Glen A. , Barry Eileen M. , Sonenshine Daniel E. , Pal Utpal , Valenzuela Jesus G. , Sztein Marcelo B. , Pasetti Marcela F. , Levin Michael L. , Kotsyfakis Michail , Jay Steven M. , Huntley Jason F. , Miller Lloyd S. , Santambrogio Laura , Pedra Joao H. F. 
Published: June 2021

AbstractExtracellular vesicles are thought to facilitate pathogen transmission from arthropods to humans and other animals. Here, we reveal that pathogen spreading from arthropods to the mammalian host is multifaceted. Extracellular vesicles fromIxodes scapularisenable tick feeding and promote infection of the mildly virulent rickettsial agentAnaplasma phagocytophilumthrough the SNARE proteins Vamp33 and Synaptobrevin 2 and dendritic epidermal T cells. However, extracellular vesicles from the tickDermacentor andersonimitigate microbial spreading caused by the lethal pathogenFrancisella tularensis. Collectively, we establish that tick extracellular vesicles foster distinct outcomes of bacterial infection and assist in vector feeding by acting on skin immunity. Thus, the biology of arthropods should be taken into consideration when developing strategies to control vector-borne diseases.
Cell-specific and divergent roles of the CD40L-CD40 axis in atherosclerotic vascular disease
Authors: Lacy Michael , Bürger Christina , Shami Annelie , Ahmadsei Maiwand , Winkels Holger , Nitz Katrin , van Tiel Claudia M. , Seijkens Tom T. P. , Kusters Pascal J. H. , Karshovka Ela , Prange Koen H. M. , Wu Yuting , Brouns Sanne L. N. , Unterlugauer Sigrid , Kuijpers Marijke J. E. , Reiche Myrthe E. , Steffens Sabine , Edsfeldt Andreas , Megens Remco T. A. , Heemskerk Johan W. M. , Goncalves Isabel , Weber Christian , Gerdes Norbert , Atzler Dorothee , Lutgens Esther 
Published: June 2021

AbstractAtherosclerosis is a major underlying cause of cardiovascular disease. Previous studies showed that inhibition of the co-stimulatory CD40 ligand (CD40L)-CD40 signaling axis profoundly attenuates atherosclerosis. As CD40L exerts multiple functions depending on the cell-cell interactions involved, we sought to investigate the function of the most relevant CD40L-expressing cell types in atherosclerosis: T cells and platelets. Atherosclerosis-prone mice with a CD40L-deficiency in CD4+ T cells display impaired Th1 polarization, as reflected by reduced interferon-γ production, and smaller atherosclerotic plaques containing fewer T-cells, smaller necrotic cores, an increased number of smooth muscle cells and thicker fibrous caps. Mice with a corresponding CD40-deficiency in CD11c+ dendritic cells phenocopy these findings, suggesting that the T cell-dendritic cell CD40L-CD40 axis is crucial in atherogenesis. Accordingly, sCD40L/sCD40 and interferon-γ concentrations in carotid plaques and plasma are positively correlated in patients with cerebrovascular disease. Platelet-specific deficiency of CD40L does not affect atherogenesis but ameliorates atherothrombosis. Our results establish divergent and cell-specific roles of CD40L-CD40 in atherosclerosis, which has implications for therapeutic strategies targeting this pathway.
Designed and biologically active protein lattices
Authors: Wang Shih-Ting , Minevich Brian , Liu Jianfang , Zhang Honghu , Nykypanchuk Dmytro , Byrnes James , Liu Wu , Bershadsky Lev , Liu Qun , Wang Tong , Ren Gang , Gang Oleg 
Published: June 2021

AbstractVersatile methods to organize proteins in space are required to enable complex biomaterials, engineered biomolecular scaffolds, cell-free biology, and hybrid nanoscale systems. Here, we demonstrate how the tailored encapsulation of proteins in DNA-based voxels can be combined with programmable assembly that directs these voxels into biologically functional protein arrays with prescribed and ordered two-dimensional (2D) and three-dimensional (3D) organizations. We apply the presented concept to ferritin, an iron storage protein, and its iron-free analog, apoferritin, in order to form single-layers, double-layers, as well as several types of 3D protein lattices. Our study demonstrates that internal voxel design and inter-voxel encoding can be effectively employed to create protein lattices with designed organization, as confirmed by in situ X-ray scattering and cryo-electron microscopy 3D imaging. The assembled protein arrays maintain structural stability and biological activity in environments relevant for protein functionality. The framework design of the arrays then allows small molecules to access the ferritins and their iron cores and convert them into apoferritin arrays through the release of iron ions. The presented study introduces a platform approach for creating bio-active protein-containing ordered nanomaterials with desired 2D and 3D organizations.
Photon upconversion through triplet exciton-mediated energy relay
Authors: Han Sanyang , Yi Zhigao , Zhang Jiangbin , Gu Qifei , Liang Liangliang , Qin Xian , Xu Jiahui , Wu Yiming , Xu Hui , Rao Akshay , Liu Xiaogang 
Published: June 2021

AbstractExploration of upconversion luminescence from lanthanide emitters through energy migration has profound implications for fundamental research and technology development. However, energy migration-mediated upconversion requires stringent experimental conditions, such as high power excitation and special migratory ions in the host lattice, imposing selection constraints on lanthanide emitters. Here we demonstrate photon upconversion of diverse lanthanide emitters by harnessing triplet exciton-mediated energy relay. Compared with gadolinium-based systems, this energy relay is less dependent on excitation power and enhances the emission intensity of Tb3+ by 158-fold. Mechanistic investigations reveal that emission enhancement is attributable to strong coupling between lanthanides and surface molecules, which enables fast triplet generation (<100 ps) and subsequent near-unity triplet transfer efficiency from surface ligands to lanthanides. Moreover, the energy relay approach supports long-distance energy transfer and allows upconversion modulation in microstructures. These findings enhance fundamental understanding of energy transfer at molecule-nanoparticle interfaces and open exciting avenues for developing hybrid, high-performance optical materials.
City footprints and SDGs provide untapped potential for assessing city sustainability
Authors: Wiedmann Thomas , Allen Cameron 
Published: June 2021

AbstractCities are recognised as central to determining the sustainability of human development. However, assessment concepts that are able to ascertain whether or not a city is sustainable are only just emerging. Here we review literature since the Sustainable Development Goals (SDGs) were agreed in 2015 and identify three strands of scientific inquiry and practice in assessing city sustainability. We find that further integration is needed. SDG monitoring and assessment of cities should take advantage of both consumption-based (footprint) accounting and benchmarking against planetary boundaries and social thresholds in order to achieve greater relevance for designing sustainable cities and urban lifestyles.
A platform for on-the-complex annulation reactions with transient aryne intermediates
Authors: Chari Jason V. , Spence Katie A. , Susick Robert B. , Garg Neil K. 
Published: June 2021

AbstractOrganometallic complexes are ubiquitous in chemistry and biology. Whereas their preparation has historically relied on ligand synthesis followed by coordination to metal centers, the ability to efficiently diversify their structures remains a synthetic challenge. A promising yet underdeveloped strategy involves the direct manipulation of ligands that are already bound to a metal center, also known as chemistry-on-the-complex. Herein, we introduce a versatile platform for on-the-complex annulation reactions using transient aryne intermediates. In one variant, organometallic complexes undergo transition metal-catalyzed annulations with in situ generated arynes to form up to six new carbon–carbon bonds. In the other variant, an organometallic complex bearing a free aryne is generated and intercepted in cycloaddition reactions to access unique scaffolds. Our studies, centered around privileged polypyridyl metal complexes, provide an effective strategy to annulate organometallic complexes and access complex metal–ligand scaffolds, while furthering the synthetic utility of strained intermediates in chemical synthesis.
Access to enantioenriched compounds bearing challenging tetrasubstituted stereocenters via kinetic resolution of auxiliary adjacent alcohols
Authors: Niu Shengtong , Zhang Hao , Xu Weici , Bagdi Prasanta Ray , Zhang Guoxiang , Liu Jinggong , Yang Shuang , Fang Xinqiang 
Published: June 2021

AbstractContemporary asymmetric catalysis faces huge challenges when prochiral substrates bear electronically and sterically unbiased substituents and when substrates show low reactivities. One of the inherent limitations of chiral catalysts and ligands is their incapability in recognizing prochiral substrates bearing similar groups. This has rendered many enantiopure substances bearing several similar substituents inaccessible. Here we report the rationale, scope, and applications of the strategy of kinetic resolution of auxiliary adjacent alcohols (KRA*) that can be used to solve the above troubles. Using this method, a large variety of optically enriched tertiary alcohols, epoxides, esters, ketones, hydroxy ketones, epoxy ketones, β-ketoesters, and tetrasubstituted methane analogs with two, three, and four spatially and electronically similar groups can be readily obtained (totally 96 examples). At the current stage, the strategy serves as the optimal solution that can complement the inability caused by direct asymmetric catalysis in getting chiral molecules with challenging fully substituted stereocenters.
Magnetic field reveals vanishing Hall response in the normal state of stripe-ordered cuprates
Authors: Shi Zhenzhong , Baity P. G. , Terzic J. , Pokharel Bal K. , Sasagawa T. , Popović Dragana 
Published: June 2021

AbstractThe origin of the weak insulating behavior of the resistivity, i.e. $${\rho }_{xx}\propto {\mathrm{ln}}\,(1/T)$$

ρ

x
x

∝
ln

(

1
/
T

)

, revealed when magnetic fields (H) suppress superconductivity in underdoped cuprates has been a longtime mystery. Surprisingly, the high-field behavior of the resistivity observed recently in charge- and spin-stripe-ordered La-214 cuprates suggests a metallic, as opposed to insulating, high-field normal state. Here we report the vanishing of the Hall coefficient in this field-revealed normal state for all $$T\ <\ (2-6){T}_{{\rm{c}}}^{0}$$
T

<

(

2
−
6

)

T

c

0

, where $${T}_{{\rm{c}}}^{0}$$

T

c

0

is the zero-field superconducting transition temperature. Our measurements demonstrate that this is a robust fundamental property of the normal state of cuprates with intertwined orders, exhibited in the previously unexplored regime of T and H. The behavior of the high-field Hall coefficient is fundamentally different from that in other cuprates such as YBa2Cu3O6+x and YBa2Cu4O8, and may imply an approximate particle-hole symmetry that is unique to stripe-ordered cuprates. Our results highlight the important role of the competing orders in determining the normal state of cuprates.
Combining machine learning and nanopore construction creates an artificial intelligence nanopore for coronavirus detection
Authors: Taniguchi Masateru , Minami Shohei , Ono Chikako , Hamajima Rina , Morimura Ayumi , Hamaguchi Shigeto , Akeda Yukihiro , Kanai Yuta , Kobayashi Takeshi , Kamitani Wataru , Terada Yutaka , Suzuki Koichiro , Hatori Nobuaki , Yamagishi Yoshiaki , Washizu Nobuei , Takei Hiroyasu , Sakamoto Osamu , Naono Norihiko , Tatematsu Kenji , Washio Takashi , Matsuura Yoshiharu , Tomono Kazunori 
Published: June 2021

AbstractHigh-throughput, high-accuracy detection of emerging viruses allows for the control of disease outbreaks. Currently, reverse transcription-polymerase chain reaction (RT-PCR) is currently the most-widely used technology to diagnose the presence of SARS-CoV-2. However, RT-PCR requires the extraction of viral RNA from clinical specimens to obtain high sensitivity. Here, we report a method for detecting novel coronaviruses with high sensitivity by using nanopores together with artificial intelligence, a relatively simple procedure that does not require RNA extraction. Our final platform, which we call the artificially intelligent nanopore, consists of machine learning software on a server, a portable high-speed and high-precision current measuring instrument, and scalable, cost-effective semiconducting nanopore modules. We show that artificially intelligent nanopores are successful in accurately identifying four types of coronaviruses similar in size, HCoV-229E, SARS-CoV, MERS-CoV, and SARS-CoV-2. Detection of SARS-CoV-2 in saliva specimen is achieved with a sensitivity of 90% and specificity of 96% with a 5-minute measurement.
Collisionless relaxation of a disequilibrated current sheet and implications for bifurcated structures
Authors: Yoon Young Dae , Yun Gunsu S. , Wendel Deirdre E. , Burch James L. 
Published: June 2021

AbstractCurrent sheets are ubiquitous plasma structures that play the crucial role of being energy sources for various magnetic phenomena. Although a plethora of current sheet equilibrium solutions have been found, the collisionless process through which a disequilibrated current sheet relaxes or equilibrates remains largely unknown. Here we show, through analyses of phase-space distributions of single-particle orbit classes and particle-in-cell simulations, that collisionless transitions among the orbit classes are responsible for this process. Bifurcated current sheets, which are readily observed in geospace but whose origins remain controversial, are shown to naturally arise from the equilibration process and thus are likely to be the underlying structures in various phenomena; comparisons of spacecraft observations to particle-in-cell simulations support this fact. The bearing of this result on previous explanations of bifurcated structures is also discussed.
Observed increasing water constraint on vegetation growth over the last three decades
Authors: Jiao Wenzhe , Wang Lixin , Smith William K. , Chang Qing , Wang Honglang , D’Odorico Paolo 
Published: June 2021

AbstractDespite the growing interest in predicting global and regional trends in vegetation productivity in response to a changing climate, changes in water constraint on vegetation productivity (i.e., water limitations on vegetation growth) remain poorly understood. Here we conduct a comprehensive evaluation of changes in water constraint on vegetation growth in the extratropical Northern Hemisphere between 1982 and 2015. We document a significant increase in vegetation water constraint over this period. Remarkably divergent trends were found with vegetation water deficit areas significantly expanding, and water surplus areas significantly shrinking. The increase in water constraints associated with water deficit was also consistent with a decreasing response time to water scarcity, suggesting a stronger susceptibility of vegetation to drought. We also observed shortened water surplus period for water surplus areas, suggesting a shortened exposure to water surplus associated with humid conditions. These observed changes were found to be attributable to trends in temperature, solar radiation, precipitation, and atmospheric CO2. Our findings highlight the need for a more explicit consideration of the influence of water constraints on regional and global vegetation under a warming climate.