bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amine-responsive cellulose-based ratiometric fluorescent materials for real-time and visual detection of shrimp and crab freshness
Authors: Jia Ruonan , Tian Weiguo , Bai Haotian , Zhang Jinming , Wang Shu , Zhang Jun 
Published: February 2019

AbstractHerein, we design and prepare cellulose-based ratiometric fluorescent materials with superior amine-response, which offers the real-time and visual detection of seafood freshness. Through utilizing the reactive hydroxyl groups along cellulose chains, we covalently immobilize the fluorescein isothiocyanate (FITC) as indicator and protoporphyrin IX (PpIX) as internal reference onto cellulose acetate (CA), respectively. Subsequently, a series of dual-emission solid fluorescent materials are achieved by simply blending green emitting CA-FITC with red-emitting CA-PpIX with varying ratios. They exhibit a sensitive, color-responsive, rapid and linear response to ammonia in a wide range of 5.0 ppm to 2.5 × 104 ppm. Benefiting from the excellent solubility and processibility of cellulose derivatives, the as-prepared materials are readily processed into different material forms, including printing ink, coating, flexible film, and nanofibrous membrane. The electrospun nanofibrous membrane is successfully employed as a low-cost, high-contrasting, quick-responsive fluorescent trademark for visual monitoring the freshness of shrimp and crab.
Resolution limit of image analysis algorithms
Authors: Cohen Edward A. K. , Abraham Anish V. , Ramakrishnan Sreevidhya , Ober Raimund J. 
Published: February 2019

AbstractThe resolution of an imaging system is a key property that, despite many advances in optical imaging methods, remains difficult to define and apply. Rayleigh’s and Abbe’s resolution criteria were developed for observations with the human eye. However, modern imaging data is typically acquired on highly sensitive cameras and often requires complex image processing algorithms to analyze. Currently, no approaches are available for evaluating the resolving capability of such image processing algorithms that are now central to the analysis of imaging data, particularly location-based imaging data. Using methods of spatial statistics, we develop a novel algorithmic resolution limit to evaluate the resolving capabilities of location-based image processing algorithms. We show how insufficient algorithmic resolution can impact the outcome of location-based image analysis and present an approach to account for algorithmic resolution in the analysis of spatial location patterns.
Oxygen vacancy associated single-electron transfer for photofixation of CO2 to long-chain chemicals
Authors: Chen Shichuan , Wang Hui , Kang Zhixiong , Jin Sen , Zhang Xiaodong , Zheng Xusheng , Qi Zeming , Zhu Junfa , Pan Bicai , Xie Yi 
Published: February 2019

AbstractThe photofixation and utilization of CO2 via single-electron mechanism is considered to be a clean and green way to produce high-value-added commodity chemicals with long carbon chains. However, this topic has not been fully explored for the highly negative reduction potential in the formation of reactive carbonate radical. Herein, by taking Bi2O3 nanosheets as a model system, we illustrate that oxygen vacancies confined in atomic layers can lower the adsorption energy of CO2 on the reactive sites, and thus activate CO2 by single-electron transfer in mild conditions. As demonstrated, Bi2O3 nanosheets with rich oxygen vacancies show enhanced generation of •CO2– species during the reaction process and achieve a high conversion yield of dimethyl carbonate (DMC) with nearly 100% selectivity in the presence of methanol. This study establishes a practical way for the photofixation of CO2 to long-chain chemicals via defect engineering.
Mutation of a single residue promotes gating of vertebrate and invertebrate two-pore domain potassium channels
Authors: Ben Soussia Ismail , El Mouridi Sonia , Kang Dawon , Leclercq-Blondel Alice , Khoubza Lamyaa , Tardy Philippe , Zariohi Nora , Gendrel Marie , Lesage Florian , Kim Eun-Jin , Bichet Delphine , Andrini Olga , Boulin Thomas 
Published: February 2019

AbstractMutations that modulate the activity of ion channels are essential tools to understand the biophysical determinants that control their gating. Here, we reveal the conserved role played by a single amino acid position (TM2.6) located in the second transmembrane domain of two-pore domain potassium (K2P) channels. Mutations of TM2.6 to aspartate or asparagine increase channel activity for all vertebrate K2P channels. Using two-electrode voltage-clamp and single-channel recording techniques, we find that mutation of TM2.6 promotes channel gating via the selectivity filter gate and increases single channel open probability. Furthermore, channel gating can be progressively tuned by using different amino acid substitutions. Finally, we show that the role of TM2.6 was conserved during evolution by rationally designing gain-of-function mutations in four Caenorhabditis elegans K2P channels using CRISPR/Cas9 gene editing. This study thus describes a simple and powerful strategy to systematically manipulate the activity of an entire family of potassium channels.
A mathematical-descriptor of tumor-mesoscopic-structure from computed-tomography images annotates prognostic- and molecular-phenotypes of epithelial ovarian cancer
Authors: Lu Haonan , Arshad Mubarik , Thornton Andrew , Avesani Giacomo , Cunnea Paula , Curry Ed , Kanavati Fahdi , Liang Jack , Nixon Katherine , Williams Sophie T. , Hassan Mona Ali , Bowtell David D. L. , Gabra Hani , Fotopoulou Christina , Rockall Andrea , Aboagye Eric O. 
Published: February 2019

AbstractThe five-year survival rate of epithelial ovarian cancer (EOC) is approximately 35–40% despite maximal treatment efforts, highlighting a need for stratification biomarkers for personalized treatment. Here we extract 657 quantitative mathematical descriptors from the preoperative CT images of 364 EOC patients at their initial presentation. Using machine learning, we derive a non-invasive summary-statistic of the primary ovarian tumor based on 4 descriptors, which we name “Radiomic Prognostic Vector” (RPV). RPV reliably identifies the 5% of patients with median overall survival less than 2 years, significantly improves established prognostic methods, and is validated in two independent, multi-center cohorts. Furthermore, genetic, transcriptomic and proteomic analysis from two independent datasets elucidate that stromal phenotype and DNA damage response pathways are activated in RPV-stratified tumors. RPV and its associated analysis platform could be exploited to guide personalized therapy of EOC and is potentially transferrable to other cancer types.
Highly efficient photothermal nanoagent achieved by harvesting energy via excited-state intramolecular motion within nanoparticles
Authors: Zhao Zheng , Chen Chao , Wu Wenting , Wang Fenfen , Du Lili , Zhang Xiaoyan , Xiong Yu , He Xuewen , Cai Yuanjing , Kwok Ryan T. K. , Lam Jacky W. Y. , Gao Xike , Sun Pingchuan , Phillips David Lee , Ding Dan , Tang Ben Zhong 
Published: February 2019

AbstractThe exciting applications of molecular motion are still limited and are in urgent pursuit, although some fascinating concepts such as molecular motors and molecular machines have been proposed for years. Utilizing molecular motion in a nanoplatform for practical application has been scarcely explored due to some unconquered challenges such as how to achieve effective molecular motion in the aggregate state within nanoparticles. Here, we introduce a class of near infrared-absorbing organic molecules with intramolecular motion-induced photothermy inside nanoparticles, which enables most absorbed light energy to dissipate as heat. Such a property makes the nanoparticles a superior photoacoustic imaging agent compared to widely used methylene blue and semiconducting polymer nanoparticles and allow them for high-contrast photoacoustic imaging of tumours in live mice. This study not only provides a strategy for developing advanced photothermal/photoacoustic imaging nanoagents, but also enables molecular motion in a nanoplatform to find a way for practical application.
Copper-catalyzed remote C(sp3)–H azidation and oxidative trifluoromethylation of benzohydrazides
Authors: Bao Xu , Wang Qian , Zhu Jieping 
Published: February 2019

AbstractThe Hofmann-Löffler-Freytag (HLF) reaction is a prototypical example of radical-based remote functionalization of unactivated C(sp3)–H bond. While 1,5-hydrogen atom transfer (1,5-HAT) of the amidyl radical is thermodynamically favorable and is well-established, the method for the subsequent functionalization of the translocated carbon radical is still limited. We report herein two catalytic remote C(sp3)–H functionalization protocols. Cu(MeCN)4PF6-catalyzed reaction of 2-alkyl benzohydrazides 3 with TMSN3 in the presence of MeCO2OtBu affords the γ-azido amides 4, while CuCl-catalyzed reaction of 3 with Togni’s reagent provides 2-(β-trifluoromethylvinyl)benzamides 5 via an oxidative δ-trifluoromethylation of the alkyl group. Mechanistic studies suggest that the γ-azidation of benzohydrazides 3 goes through 1,5-HAT followed by a Cu-mediated azido transfer cascade, while the oxidative δ-trifluoromethylation of 3 proceeds via, after 1,5-HAT process, a radical-polar crossover mechanism.
Carbon sequestration during core formation implied by complex carbon polymerization
Authors: Solomatova Natalia V. , Caracas Razvan , Manning Craig E. 
Published: February 2019

AbstractCurrent estimates of the carbon flux between the surface and mantle are highly variable, and the total amount of carbon stored in closed hidden reservoirs is unknown. Understanding the forms in which carbon existed in the molten early Earth is a critical step towards quantifying the carbon budget of Earth's deep interior. Here we employ first-principles molecular dynamics to study the evolution of carbon species as a function of pressure in a pyrolite melt. We find that with increasing pressure, the abundance of CO2 and CO3 species decreases at the expense of CO4 and complex oxo-carbon polymers (CxOy) displaying multiple C-C bonds. We anticipate that polymerized oxo-carbon species were a significant reservoir for carbon in the terrestrial magma ocean. The presence of Fe-C clusters suggests that upon segregation, Fe-rich metal may partition a significant fraction of carbon from the silicate liquid, leading to carbon transport into the Earth's core.
Structural insights into chaperone addiction of toxin-antitoxin systems
Authors: Guillet Valérie , Bordes Patricia , Bon Cécile , Marcoux Julien , Gervais Virginie , Sala Ambre Julie , Dos Reis Suzana , Slama Nawel , Mares-Mejía Israel , Cirinesi Anne-Marie , Maveyraud Laurent , Genevaux Pierre , Mourey Lionel 
Published: February 2019

AbstractSecB chaperones assist protein export by binding both unfolded proteins and the SecA motor. Certain SecB homologs can also control toxin-antitoxin (TA) systems known to modulate bacterial growth in response to stress. In such TA-chaperone (TAC) systems, SecB assists the folding and prevents degradation of the antitoxin, thus facilitating toxin inhibition. Chaperone dependency is conferred by a C-terminal extension in the antitoxin known as chaperone addiction (ChAD) sequence, which makes the antitoxin aggregation-prone and prevents toxin inhibition. Using TAC of Mycobacterium tuberculosis, we present the structure of a SecB-like chaperone bound to its ChAD peptide. We find differences in the binding interfaces when compared to SecB–SecA or SecB-preprotein complexes, and show that the antitoxin can reach a functional form while bound to the chaperone. This work reveals how chaperones can use discrete surface binding regions to accommodate different clients or partners and thereby expand their substrate repertoire and functions.
Disulfide-mediated conversion of 8-mer bowl-like protein architecture into three different nanocages
Authors: Zang Jiachen , Chen Hai , Zhang Xiaorong , Zhang Chenxi , Guo Jing , Du Ming , Zhao Guanghua 
Published: February 2019

AbstractConstructing different protein nanostructures with high-order discrete architectures by using one single building block remains a challenge. Here, we present a simple, effective disulfide-mediated approach to prepare a set of protein nanocages with different geometries from single building block. By genetically deleting an inherent intra-subunit disulfide bond, we can render the conversion of an 8-mer bowl-like protein architecture (NF-8) into a 24-mer ferritin-like nanocage in solution, while selective insertion of an inter-subunit disulfide bond into NF-8 triggers its conversion into a 16-mer lenticular nanocage. Deletion of the same intra-subunit disulfide bond and insertion of the inter-subunit disulfide bond results in the conversion of NF-8 into a 48-mer protein nanocage in solution. Thus, in the laboratory, simple mutation of one protein building block can generate three different protein nanocages in a manner that is highly reminiscent of natural pentamer building block originating from viral capsids that self-assemble into protein assemblies with different symmetries.
Designing interfaces in energy materials applications with first-principles calculations
Authors: Butler Keith T. , Sai Gautam Gopalakrishnan , Canepa Pieremanuele 
Published: February 2019

AbstractMaterials for energy-related applications, which are crucial for a sustainable energy economy, rely on combining materials that form complex heterogenous interfaces. Simultaneously, progress in computational materials science in describing complex interfaces is critical for improving the understanding and performance of energy materials. Hence, we present an in-depth review of the physical quantities regulating interfaces in batteries, photovoltaics, and photocatalysts, that are accessible from modern electronic structure methods, with a focus on density functional theory calculations. For each energy application, we highlight unique approaches that have been developed to calculate interfacial properties and explore the possibility of applying some of these approaches across disciplines, leading to a unified overview of interface design. Finally, we identify a set of challenges for further improving the theoretical description of interfaces in energy devices.
Deterministic bidirectional communication and remote entanglement generation between superconducting qubits
Authors: Leung N. , Lu Y. , Chakram S. , Naik R. K. , Earnest N. , Ma R. , Jacobs K. , Cleland A. N. , Schuster D. I. 
Published: February 2019

AbstractWe propose and experimentally demonstrate an efficient scheme for bidirectional and deterministic photonic communication between two remote superconducting modules. The two chips, each consists of a transmon, are connected through a one-meter long coaxial cable that is coupled to a dedicated “communication” resonator on each chip. The two communication resonators hybridize with a mode of the cable to form a dark “communication mode” that is highly immune to decay in the coaxial cable. We overcome the various restrictions of quantum communication channels established by other recent approaches in deterministic communication for superconducting qubits. Our approach enables bidirectional communication, and eliminates the high insertion loss and large volume footprint of circulators. We modulate the transmon frequency via a parametric drive to generate sideband interactions between the transmon and the communication mode. We demonstrate bidirectional single-photon transfer with a success probability exceeding 60%, and generate an entangled Bell pair with a fidelity of 79.3 ± 0.3%.
Dynamics of soil microbial communities following vegetation succession in a karst mountain ecosystem, Southwest China
Authors: Zhao Chang , Long Jian , Liao Hongkai , Zheng Chunli , Li Juan , Liu Lingfei , Zhang Mingjiang 
Published: February 2019

AbstractThe interaction between soil property and soil microbial community in karst area still remains an open question. The characteristics of soil physicochemical properties and microbial community structure and their relationship under five vegetation succession stages (grassland, shrub land, secondary forest, plantation forest, and natural forest) at two soil depths (0–10 cm and 10–20 cm) were explored in a karst mountain ecosystem. We found that soil moisture content (SMC) and pH increased with soil depth across vegetation succession. The highest content of soil nutrients was found in the natural forest stage at both soil depths. The total PLFAs, the abundance of Gram-positive (GP) bacteria, actinomycetes (ACT), fungi, and arbuscular mycorrhizal fungi (AMF) were significantly (P < 0.05) related to variations with soil total carbon (TC) and total nitrogen (TN). Furthermore, the distribution of soil microbial community distinctly differed in vegetation succession both at two soil layers which was demonstrated by Principal-coordinates analysis. Redundancy analyses patterns indicated that soil TC and TN were positively related to cy19:0 and 10Me 16:0, but an opposite relationship with a15:0. Changes of soil microbial communities were significantly determined by vegetation succession, and soil microbial community structure can be a sensitive indicator to reflect the stabilization of karst mountain ecosystem, southwest of China.
Genome-wide identification, characterization, interaction network and expression profile of GRAS gene family in sweet orange (Citrus sinensis)
Authors: Zhang Hua , Mi Limin , Xu Long , Yu Changxiu , Li Chen , Chen Chunli 
Published: February 2019

AbstractGRAS genes are suggested to be grouped into plant-specific transcriptional regulatory families that have been reported to participate in multiple processes, including plant development, phytohormone signaling, the formation of symbiotic relationships, and response to environmental signals. GRAS genes have been characterized in a number of plant species, but little is known about this gene family in Citrus sinensis. In this study, we identified a total of 50 GRAS genes and characterized the gene structures, conserved motifs, genome localizations and cis-elements within their promoter regions. According to their structural and phylogenetic features, the identified sweet orange GRAS members were divided into 11 subgroups, of which subfamily CsGRAS34 was sweet orange-specific. Based on publicly available RNA-seq data generated from callus, flower, leaf and fruit in sweet orange, we found that some sweet orange GRAS genes exhibited tissue-specific expression patterning. Three of the six members of subfamily AtSHR, particularly CsGRAS9, and two of the six members of subfamily AtPAT1 were preferentially expressed in leaf. Moreover, protein-protein interactions with CsGRAS were predicted. Gene expression analysis was performed under conditions of phosphate deficiency, and GA3 and NaCl treatment to identify the potential functions of GRAS members in regulating stress and hormone responses. This study provides the first comprehensive understanding of the GRAS gene family in the sweet orange genome. As such, the study generates valuable information for further gene function analysis and identifying candidate genes to improve abiotic stress tolerance in citrus plants.
Honey bees long-lasting locomotor deficits after exposure to the diamide chlorantraniliprole are accompanied by brain and muscular calcium channels alterations
Authors: Kadala Aklesso , Charreton Mercédès , Charnet Pierre , Collet Claude 
Published: February 2019

AbstractDiamides belong to one of the newest insecticides class. We characterized cellular effects of the first commercialized diamide, chlorantraniliprole (ChlorAnt). ChlorAnt not only induces a dose-dependent calcium release from internal stores of honey bee muscle cells, but also a dose-dependent blockade of the voltage-gated calcium current involved in muscles and brain excitability. We measured a long lasting impairment in locomotion after exposure to a sublethal dose and despite an apparent remission, bees suffer a critical relapse seven days later. A dose that was sublethal when applied onto the thorax turned out to induce severe mortality when applied on other body parts. Our results may help in filling the gap in the toxicological evaluation of insecticides that has recently been pointed out by international instances due to the lack of suitable tests to measure sublethal toxicity. Intoxication symptoms in bees with ChlorAnt are consistent with a mode of action on intracellular calcium release channels (ryanodine receptors, RyR) and plasma membrane voltage-gated calcium channels (CaV). A better coupling of in vitro and behavioral tests may help in more efficiently anticipating the intoxication symptoms.
A computational study of Anthracyclines interacting with lipid bilayers: Correlation of membrane insertion rates, orientation effects and localisation with cytotoxicity
Authors: Toroz D. , Gould I. R. 
Published: February 2019

AbstractAnthracyclines interact with DNA and topoisomerase II as well as with cell membranes, and it is these latter interactions that can cause an increase in their cytotoxic activity. In the present study a detailed computational analysis of the initial insertion, orientation and nature of the interaction occurring between Anthracyclines and two different lipid bilayers (unsaturated POPC and saturated DMPC) is explored through molecular dynamics (MD) simulations; four Anthracyclines: Doxorubicin (DOX), Epirubicin (EPI), Idarubicin (IDA) and Daunorubicin (DAU) were examined. The results indicate that the increased cytotoxicity of DOX, in comparison to the other three analogues, is correlated with its ability to diffuse at a faster rate into the bilayers. Additionally, DOX exhibited considerably different orientational behaviour once incorporated into the bilayer and exhibited a higher propensity to interact with the hydrocarbon tails in both lipids indicating a higher probability of transport to the other leaflet of the bilayer.
Atomic palladium on graphitic carbon nitride as a hydrogen evolution catalyst under visible light irradiation
Authors: Liu Liping , Wu Xi , Wang Li , Xu Xuejun , Gan Lin , Si Zhichun , Li Jia , Zhang Qun , Liu Yuxiang , Zhao Yanyan , Ran Rui , Wu Xiaodong , Weng Duan , Kang Feiyu 
Published: February 2019

AbstractDeveloping single-atom catalysts is extremely attractive for maximizing atomic efficiency and activity. However, the properties a nd roles of atomic catalysts in catalyzing water splitting reactions remain unclear. Here we report atomic palladium on graphitic carbon nitride with low palladium loading (0.1 wt%). The hydrogen evolution of this graphitic carbon nitride increases from 1.4 to 728 µmol g−1 h−1under visible light irradiation, which is also 10 times higher than that of palladium nanoparticles (3 wt%) counterpart. The electronic structure of graphitic carbon nitride is modified after isolated palladium is introduced, which results in efficient charge separation, appropriate sites for adsorption for hydrogen, as well as accumulation of photoinduced electrons. Our results suggest that the pyridine nitrogen in the adjacent cavity to the palladium rather than the isolated palladium site is the active site which differs to that of the palladium nanoparticle counterpart.