bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three‐Dimensional S Wave Velocity Structure of Central Japan Estimated by Surface‐Wave Tomography Using Ambient Noise
Authors: Nimiya H. , Ikeda T. , Tsuji T. 
Published: March 2020

AbstractMany significant geological features in central Japan reflect the history of tectonic events such as volcanic eruptions, fault ruptures, and the collision of the Izu‐Bonin arc. Because most previous studies focused on deep, large‐scale structures at relatively low resolution or on local structures using high‐resolution data (e.g., active source seismic data), tectonic structures over a wide area throughout central Japan have not been characterized in detail. In this study, we estimated 3D S wave velocity structures with high spatial resolution by extracting surface waves from 1‐year‐long ambient seismic data recorded by the Hi‐net high‐sensitivity seismograph network. We computed cross spectra of ambient noise data between station pairs and then extracted phase velocity dispersion curves using a frequency domain method. We developed an algorithm to calculate phase velocity and obtained numerous dispersion data. We then estimated the 3D S wave velocity structure by applying a direct surface‐wave inversion method. Our results clearly mapped heterogeneous features such as tectonic lines, sedimentary plains, and volcanic systems. We observed some low‐velocity anomalies below volcanoes. Active fault zones identified as low‐velocity zones were consistent with features on seismic reflection profiles. Several geological blocks that are related to the Izu collision were observed around the Izu Peninsula. We observed previously unreported geological features of the island of Honshu. Our high‐resolution S wave velocity model can be used for not only interpretation of geological structures but also hazard assessment of earthquake.
Influences of Solar Forcing at Ultraviolet and Longer Wavelengths on Climate
Authors: Shindell Drew T. , Faluvegi Greg , Schmidt Gavin A. 
Published: March 2020

AbstractSolar forcing has contributed minimally to modern global warming, but its role in decadal and regional climate change and the mechanisms underlying those impacts remain incompletely understood. Analyses of modern observations show inconsistent surface climate responses to the solar cycle, though a clear signal is found aloft. A “top‐down” mechanism connecting high altitudes to the surface has been documented, as has a “bottom‐up” mechanism mediated by the ocean, but their relative importance remains unclear. To investigate these issues, we performed simulations using the GISS E2‐R climate model exploring both cyclic and constant solar forcing. Simulations were driven by irradiance variations across the spectrum, and at only short (<310 nm) wavelengths, which trigger the “top‐down” mechanism, and long (≥310 nm) wavelengths, which initiate the “bottom‐up” mechanism. We find weak surface temperature response to cyclic solar forcing across all wavelengths despite a clear stratospheric response. In contrast, persistent solar forcing induces clear impacts in both the stratosphere and troposphere, including at the surface. For persistent forcing, tropical areas warm, which is almost entirely attributable to long wavelength forcing, whereas boreal winter extratropical responses include areas of warming and cooling with comparable magnitude impacts for short and long wavelength forcings. Both appear to excite similar annular mode responses, so that there is not a clear separation between the “top‐down” and “bottom‐up” mechanisms. It seems clear, however, that longwave forcing and the “bottom‐up” mechanism dominate the tropical response to solar forcing, whereas both wavelengths/mechanisms can be important at middle to high latitudes, especially during the boreal winter.
Characterization of the receptor-binding domain (RBD) of 2019 novel coronavirus: implication for development of RBD protein as a viral attachment inhibitor and vaccine
Authors: Tai Wanbo , He Lei , Zhang Xiujuan , Pu Jing , Voronin Denis , Jiang Shibo , Zhou Yusen , Du Lanying 
Published: March 2020

AbstractThe outbreak of Coronavirus Disease 2019 (COVID-19) has posed a serious threat to global public health, calling for the development of safe and effective prophylactics and therapeutics against infection of its causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as 2019 novel coronavirus (2019-nCoV). The CoV spike (S) protein plays the most important roles in viral attachment, fusion and entry, and serves as a target for development of antibodies, entry inhibitors and vaccines. Here, we identified the receptor-binding domain (RBD) in SARS-CoV-2 S protein and found that the RBD protein bound strongly to human and bat angiotensin-converting enzyme 2 (ACE2) receptors. SARS-CoV-2 RBD exhibited significantly higher binding affinity to ACE2 receptor than SARS-CoV RBD and could block the binding and, hence, attachment of SARS-CoV-2 RBD and SARS-CoV RBD to ACE2-expressing cells, thus inhibiting their infection to host cells. SARS-CoV RBD-specific antibodies could cross-react with SARS-CoV-2 RBD protein, and SARS-CoV RBD-induced antisera could cross-neutralize SARS-CoV-2, suggesting the potential to develop SARS-CoV RBD-based vaccines for prevention of SARS-CoV-2 and SARS-CoV infection.
Vibronic mixing enables ultrafast energy flow in light-harvesting complex II
Authors: Arsenault Eric A. , Yoneda Yusuke , Iwai Masakazu , Niyogi Krishna K. , Fleming Graham R. 
Published: March 2020

AbstractSince the discovery of quantum beats in the two-dimensional electronic spectra of photosynthetic pigment-protein complexes over a decade ago, the origin and mechanistic function of these beats in photosynthetic light-harvesting has been extensively debated. The current consensus is that these long-lived oscillatory features likely result from electronic-vibrational mixing, however, it remains uncertain if such mixing significantly influences energy transport. Here, we examine the interplay between the electronic and nuclear degrees of freedom (DoF) during the excitation energy transfer (EET) dynamics of light-harvesting complex II (LHCII) with two-dimensional electronic-vibrational spectroscopy. Particularly, we show the involvement of the nuclear DoF during EET through the participation of higher-lying vibronic chlorophyll states and assign observed oscillatory features to specific EET pathways, demonstrating a significant step in mapping evolution from energy to physical space. These frequencies correspond to known vibrational modes of chlorophyll, suggesting that electronic-vibrational mixing facilitates rapid EET over moderately size energy gaps.
Excitatory VTA to DH projections provide a valence signal to memory circuits
Authors: Han Yuan , Zhang Yi , Kim Haram , Grayson Viktoriya S. , Jovasevic Vladimir , Ren Wenjie , Centeno Maria V. , Guedea Anita L. , Meyer Mariah A. A. , Wu Yixin , Gutruf Philipp , Surmeier Dalton J. , Gao Can , Martina Marco , Apkarian Apkar V. , Rogers John A. , Radulovic Jelena 
Published: March 2020

AbstractThe positive or negative value (valence) of past experiences is normally integrated into neuronal circuits that encode episodic memories and plays an important role in guiding behavior. Here, we show, using mouse behavioral models, that glutamatergic afferents from the ventral tegmental area to the dorsal hippocampus (VTA→DH) signal negative valence to memory circuits, leading to the formation of fear-inducing context memories and to context-specific reinstatement of fear. To a lesser extent, these projections also contributed to opioid-induced place preference, suggesting a role in signaling positive valence as well, and thus a lack of dedicated polarity. Manipulations of VTA terminal activity were more effective in females and paralleled by sex differences in glutamatergic signaling. By prioritizing retrieval of negative and positive over neutral memories, the VTA→DH circuit can facilitate the selection of adaptive behaviors when current and past experiences are valence congruent.
A severe leakage of intermediates to shunt products in acarbose biosynthesis
Authors: Zhao Qinqin , Luo Yuchang , Zhang Xin , Kang Qianjin , Zhang Dan , Zhang Lili , Bai Linquan , Deng Zixin 
Published: March 2020

AbstractThe α-glucosidase inhibitor acarbose, produced byActinoplanessp. SE50/110, is a well-known drug for the treatment of type 2 diabetes mellitus. However, the largely unexplored biosynthetic mechanism of this compound has impeded further titer improvement. Herein, we uncover that 1-epi-valienol and valienol, accumulated in the fermentation broth at a strikingly high molar ratio to acarbose, are shunt products that are not directly involved in acarbose biosynthesis. Additionally, we find that inefficient biosynthesis of the amino-deoxyhexose moiety plays a role in the formation of these shunt products. Therefore, strategies to minimize the flux to the shunt products and to maximize the supply of the amino-deoxyhexose moiety are implemented, which increase the acarbose titer by 1.2-fold to 7.4 g L−1. This work provides insights into the biosynthesis of the C7-cyclitol moiety and highlights the importance of assessing shunt product accumulation when seeking to improve the titer of microbial pharmaceutical products.
Ca2+-Daptomycin targets cell wall biosynthesis by forming a tripartite complex with undecaprenyl-coupled intermediates and membrane lipids
Authors: Grein Fabian , Müller Anna , Scherer Katharina M. , Liu Xinliang , Ludwig Kevin C. , Klöckner Anna , Strach Manuel , Sahl Hans-Georg , Kubitscheck Ulrich , Schneider Tanja 
Published: March 2020

AbstractThe lipopeptide daptomycin is used as an antibiotic to treat severe infections with gram-positive pathogens, such as methicillin resistant Staphylococcus aureus (MRSA) and drug-resistant enterococci. Its precise mechanism of action is incompletely understood, and a specific molecular target has not been identified. Here we show that Ca2+-daptomycin specifically interacts with undecaprenyl-coupled cell envelope precursors in the presence of the anionic phospholipid phosphatidylglycerol, forming a tripartite complex. We use microbiological and biochemical assays, in combination with fluorescence and optical sectioning microscopy of intact staphylococcal cells and model membrane systems. Binding primarily occurs at the staphylococcal septum and interrupts cell wall biosynthesis. This is followed by delocalisation of components of the peptidoglycan biosynthesis machinery and massive membrane rearrangements, which may account for the pleiotropic cellular events previously reported. The identification of carrier-bound cell wall precursors as specific targets explains the specificity of daptomycin for bacterial cells. Our work reconciles apparently inconsistent previous results, and supports a concise model for the mode of action of daptomycin.
Two-dimensional gersiloxenes with tunable bandgap for photocatalytic H2 evolution and CO2 photoreduction to CO
Authors: Zhao Fulai , Feng Yiyu , Wang Yu , Zhang Xin , Liang Xuejing , Li Zhen , Zhang Fei , Wang Tuo , Gong Jinlong , Feng Wei 
Published: March 2020

AbstractThe discovery of graphene and graphene-like two-dimensional materials has brought fresh vitality to the field of photocatalysis. Bandgap engineering has always been an effective way to make semiconductors more suitable for specific applications such as photocatalysis and optoelectronics. Achieving control over the bandgap helps to improve the light absorption capacity of the semiconductor materials, thereby improving the photocatalytic performance. This work reports two-dimensional −H/−OH terminal-substituted siligenes (gersiloxenes) with tunable bandgap. All gersiloxenes are direct-gap semiconductors and have wide range of light absorption and suitable band positions for light driven water reduction into H2, and CO2 reduction to CO under mild conditions. The gersiloxene with the best performance can provide a maximum CO production of 6.91 mmol g−1 h−1, and a high apparent quantum efficiency (AQE) of 5.95% at 420 nm. This work may open up new insights into the discovery, research and application of new two-dimensional materials in photocatalysis.
New insights into US flood vulnerability revealed from flood insurance big data
Authors: Wing Oliver E. J. , Pinter Nicholas , Bates Paul D. , Kousky Carolyn 
Published: March 2020

AbstractImprovements in modelling power and input data have vastly improved the precision of physical flood models, but translation into economic outputs requires depth–damage functions that are inadequately verified. In particular, flood damage is widely assumed to increase monotonically with water depth. Here, we assess flood vulnerability in the US using >2 million claims from the National Flood Insurance Program (NFIP). NFIP claims data are messy, but the size of the dataset provides powerful empirical tests of damage patterns and modelling approaches. We show that current depth–damage functions consist of disparate relationships that match poorly with observations. Observed flood losses are not monotonic functions of depth, but instead better follow a beta function, with bimodal distributions for different water depths. Uncertainty in flood losses has been called the main bottleneck in flood risk studies, an obstacle that may be remedied using large-scale empirical flood damage data.
Efficient wavelength conversion of exchange magnons below 100 nm by magnetic coplanar waveguides
Authors: Che Ping , Baumgaertl Korbinian , Kúkol’ová Anna , Dubs Carsten , Grundler Dirk 
Published: March 2020

AbstractExchange magnons are essential for unprecedented miniaturization of GHz electronics and magnon-based logic. However, their efficient excitation via microwave fields is still a challenge. Current methods including nanocontacts and grating couplers require advanced nanofabrication tools which limit the broad usage. Here, we report efficient emission and detection of exchange magnons using micron-sized coplanar waveguides (CPWs) into which we integrated ferromagnetic (m) layers. We excited magnons in a broad frequency band with wavelengths λ down to 100 nm propagating over macroscopic distances in thin yttrium iron garnet. Applying time- and spatially resolved Brillouin light scattering as well as micromagnetic simulations we evidence a significant wavelength conversion process near mCPWs via tunable inhomogeneous fields. We show how optimized mCPWs can form microwave-to-magnon transducers providing phase-coherent exchange magnons with λ of 37 nm. Without any nanofabrication they allow one to harvest the advantages of nanomagnonics by antenna designs exploited in conventional microwave circuits.
Surface-wave-assisted nonreciprocity in spatio-temporally modulated metasurfaces
Authors: Cardin Andrew E. , Silva Sinhara R. , Vardeny Shai R. , Padilla Willie J. , Saxena Avadh , Taylor Antoinette J. , Kort-Kamp Wilton J. M. , Chen Hou-Tong , Dalvit Diego A. R. , Azad Abul K. 
Published: March 2020

AbstractEmerging photonic functionalities are mostly governed by the fundamental principle of Lorentz reciprocity. Lifting the constraints imposed by this principle could circumvent deleterious effects that limit the performance of photonic systems. Most efforts to date have been limited to waveguide platforms. Here, we propose and experimentally demonstrate a spatio-temporally modulated metasurface capable of complete violation of Lorentz reciprocity by reflecting an incident beam into far-field radiation in forward scattering, but into near-field surface waves in reverse scattering. These observations are shown both in nonreciprocal beam steering and nonreciprocal focusing. We also demonstrate nonreciprocal behavior of propagative-only waves in the frequency- and momentum-domains, and simultaneously in both. We develop a generalized Bloch-Floquet theory which offers physical insights into Lorentz nonreciprocity for arbitrary spatial phase gradients, and its predictions are in excellent agreement with experiments. Our work opens exciting opportunities in applications where free-space nonreciprocal wave propagation is desired.
Matter-wave interference of a native polypeptide
Authors: Shayeghi A. , Rieser P. , Richter G. , Sezer U. , Rodewald J. H. , Geyer P. , Martinez T. J. , Arndt M. 
Published: March 2020

AbstractThe de Broglie wave nature of matter is a paradigmatic example of quantum physics and it has been exploited in precision measurements of forces and fundamental constants. However, matter-wave interferometry has remained an outstanding challenge for natural polypeptides, building blocks of life, which are fragile and difficult to handle. Here, we demonstrate the wave nature of gramicidin, a natural antibiotic composed of 15 amino acids. Its center of mass is delocalized over more than 20 times the molecular size in our time-domain Talbot-Lau interferometer. We compare the observed interference fringes with a model that includes both a rigorous treatment of the peptide’s quantum wave nature as well as a quantum chemical assessment of its optical properties to distinguish our result from classical predictions. The realization of quantum optics with this prototypical biomolecule paves the way for quantum-assisted measurements on a large class of biologically relevant molecules.
Olfactory specificity regulates lipid metabolism through neuroendocrine signaling in Caenorhabditis elegans
Authors: Mutlu Ayse Sena , Gao Shihong Max , Zhang Haining , Wang Meng C. 
Published: March 2020

AbstractOlfactory and metabolic dysfunctions are intertwined phenomena associated with obesity and neurodegenerative diseases; yet how mechanistically olfaction regulates metabolic homeostasis remains unclear. Specificity of olfactory perception integrates diverse environmental odors and olfactory neurons expressing different receptors. Here, we report that specific but not all olfactory neurons actively regulate fat metabolism without affecting eating behaviors in Caenorhabditis elegans, and identified specific odors that reduce fat mobilization via inhibiting these neurons. Optogenetic activation or inhibition of the responsible olfactory neural circuit promotes the loss or gain of fat storage, respectively. Furthermore, we discovered that FLP-1 neuropeptide released from this olfactory neural circuit signals through peripheral NPR-4/neuropeptide receptor, SGK-1/serum- and glucocorticoid-inducible kinase, and specific isoforms of DAF-16/FOXO transcription factor to regulate fat storage. Our work reveals molecular mechanisms underlying olfactory regulation of fat metabolism, and suggests the association between olfactory perception specificity of each individual and his/her susceptibility to the development of obesity.
BrtB is an O-alkylating enzyme that generates fatty acid-bartoloside esters
Authors: Reis João P. A. , Figueiredo Sandra A. C. , Sousa Maria Lígia , Leão Pedro N. 
Published: March 2020

AbstractEsterification reactions are central to many aspects of industrial and biological chemistry. The formation of carboxyesters typically occurs through nucleophilic attack of an alcohol onto the carboxylate carbon. Under certain conditions employed in organic synthesis, the carboxylate nucleophile can be alkylated to generate esters from alkyl halides, but this reaction has only been observed transiently in enzymatic chemistry. Here, we report a carboxylate alkylating enzyme – BrtB – that catalyzes O-C bond formation between free fatty acids of varying chain length and the secondary alkyl halide moieties found in the bartolosides. Guided by this reactivity, we uncovered a variety of natural fatty acid-bartoloside esters, previously unrecognized products of the bartoloside biosynthetic gene cluster.
Stronger policy required to substantially reduce deaths from PM2.5 pollution in China
Authors: Yue Huanbi , He Chunyang , Huang Qingxu , Yin Dan , Bryan Brett A. 
Published: March 2020

AbstractAir pollution kills nearly 1 million people per year in China. In response, the Chinese government implemented the Air Pollution Prevention and Control Action Plan (APPCAP) from 2013 to 2017 which had a significant impact on reducing PM2.5 concentration. However, the health benefits of the APPCAP are not well understood. Here we examine the spatiotemporal dynamics of annual deaths attributable to PM2.5 pollution (DAPP) in China and the contribution from the APPCAP using decomposition analysis. Despite a 36.1% increase in DAPP from 2000 to 2017, The APPCAP-induced improvement in air quality achieved substantial health benefits, with the DAPP in 2017 reduced by 64 thousand (6.8%) compared to 2013. However, the policy is unlikely to result in further major reductions in DAPP and more ambitious policies are required to reduce the health impacts of air pollution by 2030 and meet the United Nation’s Sustainable Development Goal 3.
Adolescent overweight and obesity and the risk of papillary thyroid cancer in adulthood: a large-scale case-control study
Authors: Kim Kyoung-Nam , Hwang Yunji , Kim Kyu Hyung , Lee Kyu Eun , Park Young Joo , Kim Su-jin , Kwon Hyungju , Park Do Joon , Cho BeLong , Choi Ho-Chun , Kang Daehee , Park Sue K. 
Published: March 2020

AbstractThis study aimed to investigate the association between adolescent overweight and obesity and PTC risk in adulthood. We conducted a case-control study in the Republic of Korea with 1,549 PTC patients and 15,490 controls individually matched for age and sex. We estimated body mass index (BMI) at age 18 years from self-reported weight at this age. Compared with BMI < 23.0 at age 18 years, BMI ≥ 25.0 at age 18 years was associated with higher PTC risk (odds ratio [OR] = 4.31, 95% confidence interval [CI]: 3.57, 5.22). The association between BMI ≥ 25.0 at age 18 years and PTC risk was stronger among men (OR = 6.65, 95% CI: 4.78, 9.27) than among women (OR = 3.49, 95% CI: 2.74, 4.43), and stronger among individuals with current BMI ≥ 25.0 (OR = 8.21, 95% CI: 6.34, 10.62) than among those with current BMI < 25.0 (OR = 2.21, 95% CI: 1.49, 3.27). Among PTC patients, BMI ≥ 25.0 at age 18 years was associated with extra-thyroidal extension and T stage ≥2, but not with N stage ≥1 orBRAFV600Emutation. Adolescent overweight and obesity was associated with higher risk of PTC in adulthood. Our results emphasise the importance of weight management in adolescence to decrease the PTC risk.
A Combined Experimental and Theoretical Study of Screen-printing High Transparent Conductive Mesoscopic ITO Films
Authors: Qiao Feiyang , Lu Lei , Han Pingcheng , Ge Dekai , Rui Yunjun , Gu Dawei , Zhang Tianyou , Hou Jiwei , Yang Ying 
Published: March 2020

AbstractWe have successfully fabricated transparent conductive mesoporous indium tin oxide (TCM-ITO) films by a screen-printing method. The TCM-ITO films possess approximately 22 nm mesopores and obtain electrical conductivity up to 14.96 S/cm by adjusting the mass ratio of cubic-shaped ITO nanoparticles to ethyl cellulose (EC) and precisely controlling the annealing process. The regulation mechanism of EC and the heat-induced recrystallization process of ITO nanoparticles are elaborated. The internal kinetic processes of the films based on different surface states are analysed, and an extensible impedance model is established.