bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radical-mediated C-C cleavage of unstrained cycloketones and DFT study for unusual regioselectivity
Authors: Wang Mingyang , Li Man , Yang Shan , Xue Xiao-Song , Wu Xinxin , Zhu Chen 
Published: February 2020

AbstractThe C-C σ-bond activation of unstrained cycloketones represents an ingenious and advanced technique in synthetic chemistry, but it remains a challenging area which has been largely underexplored. Herein we report an efficient strategy for the direct C-C cleavage of cyclohexanones and cyclopentanones. The cyclic C-C σ-bond is readily cleaved under mild conditions with the aid of an in situ formed side-chain aryl radical. Density functional theory calculations are carried out to shed light on the unusual regioselectivity of C-C bond cleavage. The reaction affords a variety of structurally diverse 3-coumaranones and indanones that widely exist in natural products and bioactive molecules, illustrating the synthetic value of this method.
The tight junction protein TJP1 regulates the feeding-modulated hepatic circadian clock
Authors: Liu Yi , Zhang Yuanyuan , Li Tong , Han Jinbo , Wang Yiguo 
Published: January 2020

AbstractCircadian clocks in the suprachiasmatic nucleus and peripheral tissues orchestrate behavioral and physiological activities of mammals in response to environmental cues. In the liver, the circadian clock is also modulated by feeding. However, the molecular mechanisms involved are unclear. Here, we show that TJP1 (tight junction protein 1) functions as a mediator of mTOR (mechanistic target of rapamycin) to modulate the hepatic circadian clock. TJP1 interacts with PER1 (period circadian regulator 1) and prevents its nuclear translocation. During feeding, mTOR phosphorylates TJP1 and attenuates its association with PER1, thereby enhancing nuclear shuttling of PER1 to dampen circadian oscillation. Therefore, our results provide a previously uncharacterized mechanistic insight into how feeding modulates the hepatic circadian clock.
A RAF-SnRK2 kinase cascade mediates early osmotic stress signaling in higher plants
Authors: Lin Zhen , Li Yuan , Zhang Zhengjing , Liu Xiaolei , Hsu Chuan-Chih , Du Yanyan , Sang Tian , Zhu Chen , Wang Yubei , Satheesh Viswanathan , Pratibha Pritu , Zhao Yang , Song Chun-Peng , Tao W. Andy , Zhu Jian-Kang , Wang Pengcheng 
Published: January 2020

AbstractOsmoregulation is important for plant growth, development and response to environmental changes. SNF1-related protein kinase 2s (SnRK2s) are quickly activated by osmotic stress and are central components in osmotic stress and abscisic acid (ABA) signaling pathways; however, the upstream components required for SnRK2 activation and early osmotic stress signaling are still unknown. Here, we report a critical role for B2, B3 and B4 subfamilies of Raf-like kinases (RAFs) in early osmotic stress as well as ABA signaling in Arabidopsis thaliana. B2, B3 and B4 RAFs are quickly activated by osmotic stress and are required for phosphorylation and activation of SnRK2s. Analyses of high-order mutants of RAFs reveal critical roles of the RAFs in osmotic stress tolerance and ABA responses as well as in growth and development. Our findings uncover a kinase cascade mediating osmoregulation in higher plants.
In cellulo crystallization of Trypanosoma brucei IMP dehydrogenase enables the identification of genuine co-factors
Authors: Nass Karol , Redecke Lars , Perbandt M. , Yefanov O. , Klinge M. , Koopmann R. , Stellato F. , Gabdulkhakov A. , Schönherr R. , Rehders D. , Lahey-Rudolph J. M. , Aquila A. , Barty A. , Basu S. , Doak R. B. , Duden R. , Frank M. , Fromme R. , Kassemeyer S. , Katona G. , Kirian R. , Liu H. , Majoul I. , Martin-Garcia J. M. , Messerschmidt M. , Shoeman R. L. , Weierstall U. , Westenhoff S. , White T. A. , Williams G. J. , Yoon C. H. , Zatsepin N. , Fromme P. , Duszenko M. , Chapman H. N. , Betzel C. 
Published: January 2020

AbstractSleeping sickness is a fatal disease caused by the protozoan parasite Trypanosoma brucei (Tb). Inosine-5’-monophosphate dehydrogenase (IMPDH) has been proposed as a potential drug target, since it maintains the balance between guanylate deoxynucleotide and ribonucleotide levels that is pivotal for the parasite. Here we report the structure of TbIMPDH at room temperature utilizing free-electron laser radiation on crystals grown in living insect cells. The 2.80 Å resolution structure reveals the presence of ATP and GMP at the canonical sites of the Bateman domains, the latter in a so far unknown coordination mode. Consistent with previously reported IMPDH complexes harboring guanosine nucleotides at the second canonical site, TbIMPDH forms a compact oligomer structure, supporting a nucleotide-controlled conformational switch that allosterically modulates the catalytic activity. The oligomeric TbIMPDH structure we present here reveals the potential of in cellulo crystallization to identify genuine allosteric co-factors from a natural reservoir of specific compounds.
Absence of unidirectionally propagating surface plasmon-polaritons at nonreciprocal metal-dielectric interfaces
Authors: Buddhiraju Siddharth , Shi Yu , Song Alex , Wojcik Casey , Minkov Momchil , Williamson Ian A. D. , Dutt Avik , Fan Shanhui 
Published: February 2020

AbstractIn the presence of an external magnetic field, the surface plasmon polariton that exists at the metal-dielectric interface is believed to support a unidirectional frequency range near the surface plasmon frequency, where the surface plasmon polariton propagates along one but not the opposite direction. Recent works have pointed to some of the paradoxical consequences of such a unidirectional range, including in particular the violation of the time-bandwidth product constraint that should otherwise apply in general in static systems. Here we show that such a unidirectional frequency range is nonphysical using both a general thermodynamic argument and a detailed calculation based on a nonlocal hydrodynamic Drude model for the metal permittivity. Our calculation reveals that the surface plasmon-polariton at metal-dielectric interfaces remains bidirectional for all frequencies.
Dust tides and rapid meridional motions in the Martian atmosphere during major dust storms
Authors: Wu Zhaopeng , Li Tao , Zhang Xi , Li Jing , Cui Jun 
Published: January 2020

AbstractThe atmosphere of Mars is strongly affected by the spatial and temporal variability of airborne dust. However, global dust variability within a sol (Martian day) is still poorly understood. Although short-term dynamic processes are crucial, detailed comparisons of simulated diurnal variations are limited by relatively sparse observations. Here, we report the discovery of ubiquitous, strong diurnal tides of dust in the Southern Hemisphere of Mars. Driven by the westward-propagating migrating diurnal thermal tide, zonally distributed dust fronts slosh back and forth in a wide latitudinal range of up to 40° within one sol during major dust storms. Dust tides—tidal transport of dust in this way—rapidly transport heat and constituents meridionally, allowing moist air near the summer pole to be rapidly transported to lower latitudes during the night, where it then can be lifted by daytime deep convection and contribute to hydrogen escape from Mars during global dust storms.
PRMT6-mediated H3R2me2a guides Aurora B to chromosome arms for proper chromosome segregation
Authors: Kim Seul , Kim Nam Hyun , Park Ji Eun , Hwang Jee Won , Myung Nayeon , Hwang Ki-Tae , Kim Young A , Jang Chang-Young , Kim Yong Kee 
Published: January 2020

AbstractThe kinase Aurora B forms the chromosomal passenger complex (CPC) together with Borealin, INCENP, and Survivin to mediate chromosome condensation, the correction of erroneous spindle-kinetochore attachments, and cytokinesis. Phosphorylation of histone H3 Thr3 by Haspin kinase and of histone H2A Thr120 by Bub1 concentrates the CPC at the centromere. However, how the CPC is recruited to chromosome arms upon mitotic entry is unknown. Here, we show that asymmetric dimethylation at Arg2 on histone H3 (H3R2me2a) by protein arginine methyltransferase 6 (PRMT6) recruits the CPC to chromosome arms and facilitates histone H3S10 phosphorylation by Aurora B for chromosome condensation. Furthermore, in vitro assays show that Aurora B preferentially binds to the H3 peptide containing H3R2me2a and phosphorylates H3S10. Our findings indicate that the long-awaited key histone mark for CPC recruitment onto mitotic chromosomes is H3R2me2a, which is indispensable for maintaining appropriate CPC levels in dynamic translocation throughout mitosis.
Genomic regions under selection in the feralization of the dingoes
Authors: Zhang Shao-jie , Wang Guo-Dong , Ma Pengcheng , Zhang Liang-liang , Yin Ting-Ting , Liu Yan-hu , Otecko Newton O. , Wang Meng , Ma Ya-ping , Wang Lu , Mao Bingyu , Savolainen Peter , Zhang Ya-ping 
Published: February 2020

AbstractDingoes are wild canids living in Australia, originating from domestic dogs. They have lived isolated from both the wild and the domestic ancestor, making them a unique model for studying feralization. Here, we sequence the genomes of 10 dingoes and 2 New Guinea Singing Dogs. Phylogenetic and demographic analyses show that dingoes originate from dogs in southern East Asia, which migrated via Island Southeast Asia to reach Australia around 8300 years ago, and subsequently diverged into a genetically distinct population. Selection analysis identifies 50 positively selected genes enriched in digestion and metabolism, indicating a diet change during feralization of dingoes. Thirteen of these genes have shifted allele frequencies compared to dogs but not compared to wolves. Functional assays show that an A-to-G mutation in ARHGEF7 decreases the endogenous expression, suggesting behavioral adaptations related to the transitions in environment. Our results indicate that the feralization of the dingo induced positive selection on genomic regions correlated to neurodevelopment, metabolism and reproduction, in adaptation to a wild environment.
Highly skewed current–phase relation in superconductor–topological insulator–superconductor Josephson junctions
Authors: Kayyalha Morteza , Kazakov Aleksandr , Miotkowski Ireneusz , Khlebnikov Sergei , Rokhinson Leonid P. , Chen Yong P. 
Published: January 2020

AbstractThree-dimensional topological insulators (TIs) in proximity with superconductors are expected to exhibit exotic phenomena, such as topological superconductivity (TSC) and Majorana-bound states (MBS), which may have applications in topological quantum computation. In superconductor–TI–superconductor Josephson junctions, the supercurrent versus the phase difference between the superconductors, referred to as the current–phase relation (CPR), reveals important information including the nature of the superconducting transport. Here, we study the induced superconductivity in gate-tunable Josephson junctions (JJs) made from topological insulator BiSbTeSe2 with superconducting Nb electrodes. We observe highly skewed (non-sinusoidal) CPR in these junctions. The critical current, or the magnitude of the CPR, increases with decreasing temperature down to the lowest accessible temperature (T ~ 20 mK), revealing the existence of low-energy modes in our junctions. The gate dependence shows that close to the Dirac point the CPR becomes less skewed, indicating the transport is more diffusive, most likely due to the presence of electron/hole puddles and charge inhomogeneity. Our experiments provide strong evidence that superconductivity is induced in the highly ballistic topological surface states (TSS) in our gate-tunable TI-based JJs. Furthermore, the measured CPR is in good agreement with the prediction of a model which calculates the phase-dependent eigenstate energies in our system, considering the finite width of the electrodes, as well as the TSS wave functions extending over the entire circumference of the TI.
Aperiodic quantum oscillations in the two-dimensional electron gas at the LaAlO3/SrTiO3 interface
Authors: Rubi Km , Gosteau Julien , Serra Raphaël , Han Kun , Zeng Shengwei , Huang Zhen , Warot-Fonrose Benedicte , Arras Rémi , Snoeck Etienne , Ariando  , Goiran Michel , Escoffier Walter 
Published: January 2020

AbstractDespite several attempts, the intimate electronic structure of two-dimensional electron systems buried at the interface between LaAlO3 and SrTiO3 still remains to be experimentally revealed. Here, we investigate the transport properties of a high-mobility quasi-two-dimensional electron gas at this interface under high magnetic field (55 T) and provide new insights for electronic band structure by analyzing the Shubnikov-de Haas oscillations. Interestingly, the quantum oscillations are not 1∕B-periodic and produce a highly non-linear Landau plot (Landau level index versus 1/B). We explore different scenarios leading to 1/B-aperiodic oscillations where the charge and the chemical potential vary as the magnetic field increases. Overall, the magneto-transport data are discussed in light of high-resolution scanning transmission electron microscopy (HRSTEM) analysis of the interface as well as calculations from density functional theory.
Separate tuning of nematicity and spin fluctuations to unravel the origin of superconductivity in FeSe
Authors: Baek Seung-Ho , Ok Jong Mok , Kim Jun Sung , Aswartham Saicharan , Morozov Igor , Chareev Dmitriy , Urata Takahiro , Tanigaki Katsumi , Tanabe Yoichi , Büchner Bernd , Efremov Dmitri V. 
Published: January 2020

AbstractThe interplay of orbital and spin degrees of freedom is the fundamental characteristic in numerous condensed matter phenomena, including high-temperature superconductivity, quantum spin liquids, and topological semimetals. In iron-based superconductors (FeSCs), this causes superconductivity to emerge in the vicinity of two other instabilities: nematic and magnetic. Unveiling the mutual relationship among nematic order, spin fluctuations, and superconductivity has been a major challenge for research in FeSCs, but it is still controversial. Here, by carrying out 77Se nuclear magnetic resonance (NMR) measurements on FeSe single crystals, doped by cobalt and sulfur that serve as control parameters, we demonstrate that the superconducting transition temperature Tc increases in proportion to the strength of spin fluctuations, while it is independent of the nematic transition temperature Tnem. Our observation therefore directly implies that superconductivity in FeSe is essentially driven by spin fluctuations in the intermediate coupling regime, while nematic fluctuations have a marginal impact on Tc.
Projected distribution and climate refugia of endangered Kashmir musk deer Moschus cupreus in greater Himalaya, South Asia
Authors: Singh Paras Bikram , Mainali Kumar , Jiang Zhigang , Thapa Arjun , Subedi Naresh , Awan Muhammad Naeem , Ilyas Orus , Luitel Himal , Zhou Zhixin , Hu Huijian 
Published: January 2020

AbstractKashmir musk deerMoschus cupreus(KMD) are the least studied species of musk deer. We compiled genetically validated occurrence records of KMD to construct species distribution models using Maximum Entropy. We show that the distribution of KMD is limited between central Nepal on the east and north-east Afghanistan on the west and is primarily determined by precipitation of driest quarter, annual mean temperature, water vapor, and precipitation during the coldest quarter. Precipitation being the most influential determinant of distribution suggests the importance of pre-monsoon moisture for growth of the dominant vegetation, Himalayan birchBetula utilisand Himalayan firAbies spectabilis, in KMD’s preferred forests. All four Representative Concentration Pathway Scenarios result an expansion of suitable habitat in Uttarakhand, India, west Nepal and their associated areas in China in 2050s and 2070s but a dramatic loss of suitable habitat elsewhere (Kashmir region and Pakistan-Afghanistan border). About 1/4thof the current habitat will remain as climate refugia in future. Since the existing network of protected areas will only include a tiny fraction (4%) of the climatic refugia of KMD, the fate of the species will be determined by the interplay of more urgent short-term forces of poaching and habitat degradation and long-term forces of climate change.
Beamed UV sonoluminescence by aspherical air bubble collapse near liquid-metal microparticles
Authors: Boyd Bradley , Suslov Sergey A. , Becker Sid , Greentree Andrew D. , Maksymov Ivan S. 
Published: January 2020

AbstractIrradiation with UV-C band ultraviolet light is one of the most commonly used ways of disinfecting water contaminated by pathogens such as bacteria and viruses. Sonoluminescence, the emission of light from acoustically-induced collapse of air bubbles in water, is an efficient means of generating UV-C light. However, because a spherical bubble collapsing in the bulk of water creates isotropic radiation, the generated UV-C light fluence is insufficient for disinfection. Here we show, based on detailed theoretical modelling and rigorous simulations, that it should be possible to create a UV light beam from aspherical air bubble collapse near a gallium-based liquid-metal microparticle. The beam is perpendicular to the metal surface and is caused by the interaction of sonoluminescence light with UV plasmon modes of the metal. We estimate that such beams can generate fluences exceeding 10 mJ/cm2, which is sufficient to irreversibly inactivate most common pathogens in water with the turbidity of more than 5 Nephelometric Turbidity Units.
On the interplay between hypothermia and reproduction in a high arctic ungulate
Authors: Schmidt Niels M. , Grøndahl Carsten , Evans Alina L. , Desforges Jean-Pierre , Blake John , Hansen Lars H. , Beumer Larissa T. , Mosbacher Jesper B. , Stelvig Mikkel , Greunz Eva M. , Chimienti Marianna , van Beest Floris M. 
Published: January 2020

AbstractFor free-ranging animals living in seasonal environments, hypometabolism (lowered metabolic rate) and hypothermia (lowered body temperature) can be effective physiological strategies to conserve energy when forage resources are low. To what extent such strategies are adopted by large mammals living under extreme conditions, as those encountered in the high Arctic, is largely unknown, especially for species where the gestation period overlaps with the period of lowest resource availability (i.e. winter). Here we investigated for the first time the level to which high arctic muskoxen (Ovibos moschatus) adopt hypothermia and tested the hypothesis that individual plasticity in the use of hypothermia depends on reproductive status. We measured core body temperature over most of the gestation period in both free-ranging muskox females in Greenland and captive female muskoxen in Alaska. We found divergent overwintering strategies according to reproductive status, where pregnant females maintained stable body temperatures during winter, while non-pregnant females exhibited a temporary decrease in their winter body temperature. These results show that muskox females use hypothermia during periods of resource scarcity, but also that the use of this strategy may be limited to non-reproducing females. Our findings suggest a trade-off between metabolically-driven energy conservation during winter and sustaining foetal growth, which may also apply to other large herbivores living in highly seasonal environments elsewhere.
Systematic Comparison of High-throughput Single-Cell and Single-Nucleus Transcriptomes during Cardiomyocyte Differentiation
Authors: Selewa Alan , Dohn Ryan , Eckart Heather , Lozano Stephanie , Xie Bingqing , Gauchat Eric , Elorbany Reem , Rhodes Katherine , Burnett Jonathan , Gilad Yoav , Pott Sebastian , Basu Anindita 
Published: January 2020

AbstractA comprehensive reference map of all cell types in the human body is necessary for improving our understanding of fundamental biological processes and in diagnosing and treating disease. High-throughput single-cell RNA sequencing techniques have emerged as powerful tools to identify and characterize cell types in complex and heterogeneous tissues. However, extracting intact cells from tissues and organs is often technically challenging or impossible, for example in heart or brain tissue. Single-nucleus RNA sequencing provides an alternative way to obtain transcriptome profiles of such tissues. To systematically assess the differences between high-throughput single-cell and single-nuclei RNA-seq approaches, we compared Drop-seq and DroNc-seq, two microfluidic-based 3′ RNA capture technologies that profile total cellular and nuclear RNA, respectively, during a time course experiment of human induced pluripotent stem cells (iPSCs) differentiating into cardiomyocytes. Clustering of time-series transcriptomes from Drop-seq and DroNc-seq revealed six distinct cell types, five of which were found in both techniques. Furthermore, single-cell trajectories reconstructed from both techniques reproduced expected differentiation dynamics. We then applied DroNc-seq to postmortem heart tissue to test its performance on heterogeneous human tissue samples. Our data confirm that DroNc-seq yields similar results to Drop-seq on matched samples and can be successfully used to generate reference maps for the human cell atlas.
Reversible Atmospheric Water Harvesting Using Metal-Organic Frameworks
Authors: Logan Matthew W. , Langevin Spencer , Xia Zhiyong 
Published: January 2020

AbstractThe passive capture of clean water from humid air without reliance on bulky equipment and high energy has been a substantial challenge and has attracted significant interest as a potential environmentally friendly alternative to traditional water harvesting methods. Metal-organic frameworks (MOFs) offer a high potential for this application due to their structural versatility which permits scalable, facile modulations of structural and functional elements. Although MOFs are promising materials for water harvesting, little research has been done to address the microstructure-adsorbing characteristics relationship with respect to the dynamic adsorption-desorption process. In this article, we present a parametric study of nine hydrolytically stable MOFs with diverse structures for unraveling fundamental material properties that govern the kinetics of water sequestration in this class of materials as well as investigating overall uptake capacity gravimetrically. The effects of temperature, relative humidity, and powder bed thickness on the adsorption-desorption process are explored for achieving optimal operational parameters. We found that Zr-MOF-808 can produce up to 8.66 LH2O kg−1MOF day−1, an extraordinary finding that outperforms any previously reported values for MOF-based systems. The presented findings help to deepen our understanding and guide the discovery of next-generation water harvesting materials.