bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrasensitive detection of local acoustic vibrations at room temperature by plasmon-enhanced single-molecule fluorescence
Authors: Xie Mingcai , Liu Hanyu , Wan Sushu , Lu Xuxing , Hong Daocheng , Du Yu , Yang Weiqing , Wei Zhihong , Fang Susu , Tao Chen-Lei , Xu Dan , Wang Boyang , Lu Siyu , Wu Xue-Jun , Xu Weigao , Orrit Michel , Tian Yuxi 
Published: June 2022

AbstractSensitive detection of local acoustic vibrations at the nanometer scale has promising potential applications involving miniaturized devices in many areas, such as geological exploration, military reconnaissance, and ultrasound imaging. However, sensitive detection of weak acoustic signals with high spatial resolution at room temperature has become a major challenge. Here, we report a nanometer-scale system for acoustic detection with a single molecule as a probe based on minute variations of its distance to the surface of a plasmonic gold nanorod. This system can extract the frequency and amplitude of acoustic vibrations with experimental and theoretical sensitivities of 10 pm Hz−1/2 and 10 fm Hz−1/2, respectively. This approach provides a strategy for the optical detection of acoustic waves based on molecular spectroscopy without electromagnetic interference. Moreover, such a small nano-acoustic detector with 40-nm size can be employed to monitor acoustic vibrations or read out the quantum states of nanomechanical devices.
Efferocytosis requires periphagosomal Ca2+-signaling and TRPM7-mediated electrical activity
Authors: Schappe Michael S. , Stremska Marta E. , Busey Gregory W. , Downs Taylor K. , Seegren Philip V. , Mendu Suresh K. , Flegal Zachary , Doyle Catherine A. , Stipes Eric J. , Desai Bimal N. 
Published: June 2022

AbstractEfficient clearance of apoptotic cells by phagocytosis, also known as efferocytosis, is fundamental to developmental biology, organ physiology, and immunology. Macrophages use multiple mechanisms to detect and engulf apoptotic cells, but the signaling pathways that regulate the digestion of the apoptotic cell cargo, such as the dynamic Ca2+signals, are poorly understood. Using an siRNA screen, we identify TRPM7 as a Ca2+-conducting ion channel essential for phagosome maturation during efferocytosis.Trpm7-targeted macrophages fail to fully acidify or digest their phagosomal cargo in the absence of TRPM7. Through perforated patch electrophysiology, we demonstrate that TRPM7 mediates a pH-activated cationic current necessary to sustain phagosomal acidification. Using mice expressing a genetically-encoded Ca2+sensor, we observe that phagosome maturation requires peri-phagosomal Ca2+-signals dependent on TRPM7. Overall, we reveal TRPM7 as a central regulator of phagosome maturation during macrophage efferocytosis.
Probing material absorption and optical nonlinearity of integrated photonic materials
Authors: Gao Maodong , Yang Qi-Fan , Ji Qing-Xin , Wang Heming , Wu Lue , Shen Boqiang , Liu Junqiu , Huang Guanhao , Chang Lin , Xie Weiqiang , Yu Su-Peng , Papp Scott B. , Bowers John E. , Kippenberg Tobias J. , Vahala Kerry J. 
Published: June 2022

AbstractOptical microresonators with high quality (Q) factors are essential to a wide range of integrated photonic devices. Steady efforts have been directed towards increasing microresonator Q factors across a variety of platforms. With success in reducing microfabrication process-related optical loss as a limitation of Q, the ultimate attainable Q, as determined solely by the constituent microresonator material absorption, has come into focus. Here, we report measurements of the material-limited Q factors in several photonic material platforms. High-Q microresonators are fabricated from thin films of SiO2, Si3N4, Al0.2Ga0.8As, and Ta2O5. By using cavity-enhanced photothermal spectroscopy, the material-limited Q is determined. The method simultaneously measures the Kerr nonlinearity in each material and reveals how material nonlinearity and ultimate Q vary in a complementary fashion across photonic materials. Besides guiding microresonator design and material development in four material platforms, the results help establish performance limits in future photonic integrated systems.
Force–reversible chemical reaction at ambient temperature for designing toughened dynamic covalent polymer networks
Authors: Du Mengqi , Houck Hannes A. , Yin Qiang , Xu Yewei , Huang Ying , Lan Yang , Yang Li , Du Prez Filip E. , Chang Guanjun 
Published: June 2022

AbstractForce-reversible C-N bonds, resulting from the click chemistry reaction between triazolinedione (TAD) and indole derivatives, offer exciting opportunities for molecular-level engineering to design materials that respond to mechanical loads. Here, we displayed that TAD-indole adducts, acting as crosslink points in dry-state covalently crosslinked polymers, enable materials to display reversible stress-responsiveness in real time already at ambient temperature. Whereas the exergonic TAD-indole reaction results in the formation of bench-stable adducts, they were shown to dissociate at ambient temperature when embedded in a polymer network and subjected to a stretching force to recover the original products. Moreover, the nascent TAD moiety can spontaneously and immediately be recombined after dissociation with an indole reaction partners at ambient temperature, thus allowing for the adjustment of the polymer segment conformation and the maintenance of the network integrity by force-reversible behaviors. Overall, our strategy represents a general method to create toughened covalently crosslinked polymer materials with simultaneous enhancement of mechanical strength and ductility, which is quite challenging to achieve by conventional chemical methods.
Spontaneous water-on-water spreading of polyelectrolyte membranes inspired by skin formation
Authors: Tang Sihan , Gong Jiang , Shi Yunsong , Wen Shifeng , Zhao Qiang 
Published: June 2022

AbstractStable interfaces between immiscible solvents are crucial for chemical synthesis and assembly, but interfaces between miscible solvents have been less explored. Here the authors report the spontaneous water-on-water spreading and self-assembly of polyelectrolyte membranes. An aqueous mixture solution containing poly(ethyleneimine) and poly(sodium 4-styrenesulfonate) spreads efficiently on acidic water, leading to the formation of hierarchically porous membranes. The reduced surface tension of the polyelectrolyte mixture solution drives the surface spreading, while the interfacial polyelectrolytes complexation triggered by the low pH of water mitigates water-in-water mixing. The synergy of surface tension and pH-dependent complexation represents a generic mechanism governing interfaces between miscible solvents for materials engineering, without the need for surfactants or sophisticated equipment. As a proof-of-concept, porous polyelectrolyte hybrid membranes are prepared by surface spreading, exhibiting exceptional solar thermal evaporation performance (2.8 kg/m2h) under 1-sun irradiation.
Imaging translational control by Argonaute with single-molecule resolution in live cells
Authors: Cialek Charlotte A. , Galindo Gabriel , Morisaki Tatsuya , Zhao Ning , Montgomery Taiowa A. , Stasevich Timothy J. 
Published: June 2022

AbstractA major challenge to our understanding of translational control has been deconvolving the individual impact specific regulatory factors have on the complex dynamics of mRNA translation. MicroRNAs (miRNAs), for example, guide Argonaute and associated proteins to target mRNAs, where they direct gene silencing in multiple ways that are not well understood. To better deconvolve these dynamics, we have developed technology to directly visualize and quantify the impact of human Argonaute2 (Ago2) on the translation and subcellular localization of individual reporter mRNAs in living cells. We show that our combined translation and Ago2 tethering sensor reflects endogenous miRNA-mediated gene silencing. Using the sensor, we find that Ago2 association leads to progressive silencing of translation at individual mRNA. Silencing was occasionally interrupted by brief bursts of translational activity and took 3–4 times longer than a single round of translation, consistent with a gradual increase in the inhibition of translation initiation. At later time points, Ago2-tethered mRNAs cluster and coalesce with P-bodies, where a translationally silent state is maintained. These results provide a framework for exploring miRNA-mediated gene regulation in live cells at the single-molecule level. Furthermore, our tethering-based, single-molecule reporter system will likely have wide-ranging application in studying RNA-protein interactions.
Nickel catalyzed multicomponent stereodivergent synthesis of olefins enabled by electrochemistry, photocatalysis and photo-electrochemistry
Authors: Zhu Chen , Yue Huifeng , Rueping Magnus 
Published: June 2022

AbstractTrisubstituted alkenes are important organic synthons and have broad applications in the synthesis of many pharmaceuticals and materials. The stereoselective synthesis of such compounds has long been a research focus for organic researchers. Herein, we report a three-component, reductive cascade, cross-coupling reaction for the arylalkylation of alkynes. A wide range of trisubstituted alkenes are obtained in good to high yields with excellent chemo- and stereoselectivity by switching between electrochemistry and photocatalysis. The E isomer of the product is obtained exclusively when the reaction is conducted with electricity and nickel, while the Z isomer is generated with high stereoselectivity when photo- and nickel dual catalysts are used. Moreover, photo-assisted electrochemically enabled nickel catalyzed protocol is demonstrated to selectively deliver Z-trisubstituted alkenes without the addition of photocatalysts.
Molecularly cleavable bioinks facilitate high-performance digital light processing-based bioprinting of functional volumetric soft tissues
Authors: Wang Mian , Li Wanlu , Hao Jin , Gonzales Arthur , Zhao Zhibo , Flores Regina Sanchez , Kuang Xiao , Mu Xuan , Ching Terry , Tang Guosheng , Luo Zeyu , Garciamendez-Mijares Carlos Ezio , Sahoo Jugal Kishore , Wells Michael F. , Niu Gengle , Agrawal Prajwal , Quiñones-Hinojosa Alfredo , Eggan Kevin , Zhang Yu Shrike 
Published: June 2022

AbstractDigital light processing bioprinting favors biofabrication of tissues with improved structural complexity. However, soft-tissue fabrication with this method remains a challenge to balance the physical performances of the bioinks for high-fidelity bioprinting and suitable microenvironments for the encapsulated cells to thrive. Here, we propose a molecular cleavage approach, where hyaluronic acid methacrylate (HAMA) is mixed with gelatin methacryloyl to achieve high-performance bioprinting, followed by selectively enzymatic digestion of HAMA, resulting in tissue-matching mechanical properties without losing the structural complexity and fidelity. Our method allows cellular morphological and functional improvements across multiple bioprinted tissue types featuring a wide range of mechanical stiffness, from the muscles to the brain, the softest organ of the human body. This platform endows us to biofabricate mechanically precisely tunable constructs to meet the biological function requirements of target tissues, potentially paving the way for broad applications in tissue and tissue model engineering.
Three-dimensional network of filamentary currents and super-thermal electrons during magnetotail magnetic reconnection
Authors: Li Xinmin , Wang Rongsheng , Lu Quanming , Russell Christopher T. , Lu San , Cohen Ian J. , Ergun R. E. , Wang Shui 
Published: June 2022

AbstractMagnetic reconnection is a fundamental plasma process by which magnetic field lines on two sides of the current sheet flow inward to yield an X-line topology. It is responsible for producing energetic electrons in explosive phenomena in space, astrophysical, and laboratorial plasmas. The X-line region is supposed to be the important place for generating energetic electrons. However, how these energetic electrons are generated in such a limited region is still poorly understood. Here, using Magnetospheric multiscale mission data acquired in Earth’s magnetotail, we present direct evidence of super-thermal electrons up to 300 keV inside an X-line region, and the electrons display a power-law spectrum with an index of about 8.0. Concurrently, three-dimensional network of dynamic filamentary currents in electron scale is observed and leads to electromagnetic turbulence therein. The observations indicate that the electrons are effectively accelerated while the X-line region evolves into turbulence with a complex filamentary current network.
Iridium-catalyzed direct asymmetric reductive amination utilizing primary alkyl amines as the N-sources
Authors: Wu Zitong , Wang Wenji , Guo Haodong , Gao Guorui , Huang Haizhou , Chang Mingxin 
Published: June 2022

AbstractDirect asymmetric reductive amination is one of the most efficient methods for the construction of chiral amines, in which the scope of the applicable amine coupling partners remains a significant challenge. In this study we describe primary alkyl amines effectively serve as the N-sources in direct asymmetric reductive amination catalyzed by the iridium precursor and sterically tunable chiral phosphoramidite ligands. The density functional theory studies of the reaction mechanism imply the alkyl amine substrates serve as a ligand of iridium strengthened by a (N)H-O(P) hydrogen-bonding attraction, and the hydride addition occurs via an outer-sphere transition state, in which the Cl-H H-bonding plays an important role. Through this concise procedure, cinacalcet, tecalcet, fendiline and many other related chiral amines have been synthesized in one single step with high yields and excellent enantioselectivity.
Association between resting-state functional brain connectivity and gene expression is altered in autism spectrum disorder
Authors: Berto Stefano , Treacher Alex H. , Caglayan Emre , Luo Danni , Haney Jillian R. , Gandal Michael J. , Geschwind Daniel H. , Montillo Albert A. , Konopka Genevieve 
Published: June 2022

AbstractGene expression covaries with brain activity as measured by resting state functional magnetic resonance imaging (MRI). However, it is unclear how genomic differences driven by disease state can affect this relationship. Here, we integrate from the ABIDE I and II imaging cohorts with datasets of gene expression in brains of neurotypical individuals and individuals with autism spectrum disorder (ASD) with regionally matched brain activity measurements from fMRI datasets. We identify genes linked with brain activity whose association is disrupted in ASD. We identified a subset of genes that showed a differential developmental trajectory in individuals with ASD compared with controls. These genes are enriched in voltage-gated ion channels and inhibitory neurons, pointing to excitation-inhibition imbalance in ASD. We further assessed differences at the regional level showing that the primary visual cortex is the most affected region in ASD. Our results link disrupted brain expression patterns of individuals with ASD to brain activity and show developmental, cell type, and regional enrichment of activity linked genes.
Extracellular release of two peptidases dominates generation of the trypanosome quorum-sensing signal
Authors: Tettey Mabel Deladem , Rojas Federico , Matthews Keith R. 
Published: June 2022

AbstractTrypanosomes causing African sleeping sickness use quorum-sensing (QS) to generate transmission-competent stumpy forms in mammalian hosts. This density-dependent process is signalled by oligopeptides that stimulate the signal transduction pathway leading to stumpy formation. Here, using mass spectrometry analysis, we identify peptidases released by trypanosomes and, for 12 peptidases, confirm their extracellular delivery. Thereafter, we determine the contribution of each peptidase to QS signal production using systematic inducible overexpression in vivo, and confirm this activity operates through the physiological QS signalling pathway. Gene knockout of the QS-active peptidases identifies two enzymes, oligopeptidase B and metallocarboxypeptidase 1, that significantly reduce QS when ablated individually. Further, combinatorial gene knockout of both peptidases confirms their dominance in the generation of the QS signal, with peptidase release of oligopeptidase B mediated via an unconventional protein secretion pathway. This work identifies how the QS signal driving trypanosome virulence and transmission is generated in mammalian hosts.
Airway Prevotella promote TLR2-dependent neutrophil activation and rapid clearance of Streptococcus pneumoniae from the lung
Authors: Horn Kadi J. , Schopper Melissa A. , Drigot Zoe G. , Clark Sarah E. 
Published: June 2022

AbstractThis study investigates how specific members of the lung microbiome influence the early immune response to infection. Prevotella species are a major component of the endogenous airway microbiota. Increased abundance of Prevotella melaninogenica correlates with reduced infection with the bacterial pathogen Streptococcus pneumoniae, indicating a potentially beneficial role. Here, we show that P. melaninogenica enhances protection against S. pneumoniae, resulting in rapid pathogen clearance from the lung and improved survival in a mouse lung co-infection model. This response requires recognition of P. melaninogenica lipoproteins by toll-like receptor (TLR)2, the induction of TNFα, and neutrophils, as the loss of any of these factors abrogates Prevotella-induced protection. Improved clearance of S. pneumoniae is associated with increased serine protease-mediated killing by lung neutrophils and restraint of P. melaninogenica-induced inflammation by IL-10 in co-infected mice. Together, these findings highlight innate immune priming by airway Prevotella as an important protective feature in the respiratory tract.
Converting waste PET plastics into automobile fuels and antifreeze components
Authors: Gao Zhiwen , Ma Bing , Chen Shuang , Tian Jingqing , Zhao Chen 
Published: June 2022

AbstractWith the aim to solve the serious problem of white plastic pollution, we report herein a low-cost process to quantitatively convert polyethylene terephthalate (PET) into p-xylene (PX) and ethylene glycol (EG) over modified Cu/SiO2 catalyst using methanol as both solvent and hydrogen donor. Kinetic and in-situ Fourier-transform infrared spectroscopy (FTIR) studies demonstrate that the degradation of PET into PX involves tandem PET methanolysis and dimethyl terephthalate (DMT) selective hydro-deoxygenation (HDO) steps with the in-situ produced H2 from methanol decomposition at 210 °C. The overall high activities are attributed to the high Cu+/Cu0 ratio derived from the dense and granular copper silicate precursor, as formed by the induction of proper NaCl addition during the hydrothermal synthesis. This hydrogen-free one-pot approach allows to directly produce gasoline fuels and antifreeze components from waste poly-ester plastic, providing a feasible solution to the plastic problem in islands.
Parallel ventral hippocampus-lateral septum pathways differentially regulate approach-avoidance conflict
Authors: Yeates Dylan C. M. , Leavitt Dallas , Sujanthan Sajeevan , Khan Nisma , Alushaj Denada , Lee Andy C. H. , Ito Rutsuko 
Published: June 2022

AbstractThe ability to resolve an approach-avoidance conflict is critical to adaptive behavior. The ventral CA3 (vCA3) and CA1 (vCA1) subfields of the ventral hippocampus (vHPC) have been shown to facilitate avoidance and approach behavior, respectively, in the face of motivational conflict, but the neural circuits by which this subfield-specific regulation is implemented is unknown. We demonstrate that two distinct pathways from these subfields to lateral septum (LS) contribute to this divergent control. In Long-Evans rats, chemogenetic inhibition of the vCA3- LS caudodorsal (cd) pathway potentiated approach towards a learned conflict-eliciting stimulus, while inhibition of the vCA1-LS rostroventral (rv) pathway potentiated approach non-specifically. Additionally, vCA3-LScd inhibited animals were less hesitant to explore food during environmental uncertainty, while the vCA1- LSrv inhibited animals took longer to initiate food exploration. These findings suggest that the vHPC influences multiple behavioral systems via differential projections to the LS, which in turn send inhibitory projections to motivational centres of the brain.
A Catharanthus roseus Fe(II)/α-ketoglutarate-dependent dioxygenase catalyzes a redox-neutral reaction responsible for vindolinine biosynthesis
Authors: Eng Jasmine Ga May , Shahsavarani Mohammadamin , Smith Daniel Patrick , Hájíček Josef , De Luca Vincenzo , Qu Yang 
Published: June 2022

AbstractThe Madagascar’s periwinkle is the model plant for studies of plant specialized metabolism and monoterpenoid indole alkaloids (MIAs), and an important source for the anticancer medicine vinblastine. The elucidation of entire 28-step biosynthesis of vinblastine allowed further investigations for the formation of other remarkably complex bioactive MIAs. In this study, we describe the discovery and characterization of vindolinine synthase, a Fe(II)/α-ketoglutarate-dependent (Fe/2OG) dioxygenase, that diverts assembly of tabersonine to vinblastine toward the formation of three alternatively cyclized MIAs: 19S-vindolinine, 19R-vindolinine, and venalstonine. Vindolinine synthase catalyzes a highly unusual, redox-neutral reaction to form a radical from dehydrosecodine, which is further cyclized by hydrolase 2 to form the three MIA isomers. We further show the biosynthesis of vindolinine epimers from tabersonine using hydrolase 2 catalyzed reverse cycloaddition. While the occurrence of vindolinines is rare in nature, the more widely found venalstonine derivatives are likely formed from similar redox-neutral reactions by homologous Fe/2OG dioxygenases.
A statistical perspective on baseline adjustment in pharmacogenomic genome-wide association studies of quantitative change
Authors: Zhang Hong , Chhibber Aparna , Shaw Peter M. , Mehrotra Devan V. , Shen Judong 
Published: June 2022

AbstractIn pharmacogenetic (PGx) studies, drug response phenotypes are often measured in the form of change in a quantitative trait before and after treatment. There is some debate in recent literature regarding baseline adjustment, or inclusion of pre-treatment or baseline value as a covariate, in PGx genome-wide association studies (GWAS) analysis. Here, we provide a clear statistical perspective on this baseline adjustment issue by running extensive simulations based on nine statistical models to evaluate the influence of baseline adjustment on type I error and power. We then apply these nine models to analyzing the change in low-density lipoprotein cholesterol (LDL-C) levels with ezetimibe + simvastatin combination therapy compared with simvastatin monotherapy therapy in the 5661 participants of the IMPROVE-IT (IMProved Reduction of Outcomes: Vytroin Efficacy International Trial) PGx GWAS, supporting the conclusions drawn from our simulations. Both simulations and GWAS analyses consistently show that baseline-unadjusted models inflate type I error for the variants associated with baseline value if the baseline value is also associated with change from baseline (e.g., when baseline value is a mediator between a variant and change from baseline), while baseline-adjusted models can control type I error in various scenarios. We thus recommend performing baseline-adjusted analyses in PGx GWASs of quantitative change.