bluuebunny/crossref_metadata_2025_split huggingface dataset:
Negative circular polarization emissions from WSe2/MoSe2 commensurate heterobilayers
Authors: Hsu Wei-Ting , Lu Li-Syuan , Wu Po-Hsun , Lee Ming-Hao , Chen Peng-Jen , Wu Pei-Ying , Chou Yi-Chia , Jeng Horng-Tay , Li Lain-Jong , Chu Ming-Wen , Chang Wen-Hao 
Published: April 2018

AbstractVan der Waals heterobilayers of transition metal dichalcogenides with spin–valley coupling of carriers in different layers have emerged as a new platform for exploring spin/valleytronic applications. The interlayer coupling was predicted to exhibit subtle changes with the interlayer atomic registry. Manually stacked heterobilayers, however, are incommensurate with the inevitable interlayer twist and/or lattice mismatch, where the properties associated with atomic registry are difficult to access by optical means. Here, we unveil the distinct polarization properties of valley-specific interlayer excitons using epitaxially grown, commensurate WSe2/MoSe2 heterobilayers with well-defined (AA and AB) atomic registry. We observe circularly polarized photoluminescence from interlayer excitons, but with a helicity opposite to the optical excitation. The negative circular polarization arises from the quantum interference imposed by interlayer atomic registry, giving rise to distinct polarization selection rules for interlayer excitons. Using selective excitation schemes, we demonstrate the optical addressability for interlayer excitons with different valley configurations and polarization helicities.
Inhibition of cancer stem cell like cells by a synthetic retinoid
Authors: Chen Junwei , Cao Xin , An Quanlin , Zhang Yao , Li Ke , Yao Wenting , Shi Fuchun , Pan Yanfang , Jia Qiong , Zhou Wenwen , Yang Fang , Wei Fuxiang , Wang Ning , Yu Biao 
Published: April 2018

AbstractDeveloping novel drugs that can abrogate the growth and metastasis of malignant tumors is a major challenge for cancer researchers. Here we describe a novel synthetic retinoid, namely WYC-209, which inhibits proliferation of malignant murine melanoma tumor-repopulating cells (TRCs), known to resist conventional drug treatment, with an IC50 of 0.19 μM in a dose-dependent manner. WYC-209 also inhibits proliferation of TRCs of human melanoma, lung cancer, ovarian cancer, and breast cancer in culture. Interestingly, the treated TRCs fail to resume growth even after the drug washout. Importantly, the molecule abrogates 87.5% of lung metastases of melanoma TRCs in immune-competent wild-type C57BL/6 mice at 0.22 mg kg−1 without showing apparent toxicity. Pretreating the melanoma TRCs with retinoic acid receptor (RAR) antagonists or with RAR siRNAs blocks or reduces the inhibitory effect of the molecule, suggesting that the target of the molecule is RAR. WYC-209 induces TRC apoptosis and pretreating the TRCs with caspase 3 inhibitor or depleting caspase 3 with siRNAs substantially rescues growth of TRCs from WYC-209 inhibition, suggesting that WYC-209 induces TRCs apoptosis primarily via the caspase 3 pathway. Our findings demonstrate the promise of the new retinoid WYC-209 in treating malignant melanoma tumors with high efficacy and little toxicity.
Chemically triggered drug release from an antibody-drug conjugate leads to potent antitumour activity in mice
Authors: Rossin Raffaella , Versteegen Ron M. , Wu Jeremy , Khasanov Alisher , Wessels Hans J. , Steenbergen Erik J. , ten Hoeve Wolter , Janssen Henk M. , van Onzen Arthur H. A. M. , Hudson Peter J. , Robillard Marc S. 
Published: April 2018

AbstractCurrent antibody-drug conjugates (ADCs) target internalising receptors on cancer cells leading to intracellular drug release. Typically, only a subset of patients with solid tumours has sufficient expression of such a receptor, while there are suitable non-internalising receptors and stroma targets. Here, we demonstrate potent therapy in murine tumour models using a non-internalising ADC that releases its drugs upon a click reaction with a chemical activator, which is administered in a second step. This was enabled by the development of a diabody-based ADC with a high tumour uptake and very low retention in healthy tissues, allowing systemic administration of the activator 2 days later, leading to efficient and selective activation throughout the tumour. In contrast, the analogous ADC comprising the protease-cleavable linker used in the FDA approved ADC Adcetris is not effective in these tumour models. This first-in-class ADC holds promise for a broader applicability of ADCs across patient populations.
Gold nanocrystal-mediated sliding of doublet DNA origami filaments
Authors: Urban Maximilian J. , Both Steffen , Zhou Chao , Kuzyk Anton , Lindfors Klas , Weiss Thomas , Liu Na 
Published: April 2018

AbstractSliding is one of the fundamental mechanical movements in machinery. In macroscopic systems, double-rack pinion machines employ gears to slide two linear tracks along opposite directions. In microscopic systems, kinesin-5 proteins crosslink and slide apart antiparallel microtubules, promoting spindle bipolarity and elongation during mitosis. Here we demonstrate an artificial nanoscopic analog, in which gold nanocrystals can mediate coordinated sliding of two antiparallel DNA origami filaments powered by DNA fuels. Stepwise and reversible sliding along opposite directions is in situ monitored and confirmed using fluorescence spectroscopy. A theoretical model including different energy transfer mechanisms is developed to understand the observed fluorescence dynamics. We further show that such sliding can also take place in the presence of multiple DNA sidelocks that are introduced to inhibit the relative movements. Our work enriches the toolbox of DNA-based nanomachinery, taking one step further toward the vision of molecular nanofactories.
Energy-loss return gate via liquid dielectric polarization
Authors: Kim Taehun , Yong Hyungseok , Kim Banseok , Kim Dongseob , Choi Dukhyun , Park Yong Tae , Lee Sangmin 
Published: April 2018

AbstractThere has been much research on renewable energy-harvesting techniques. However, owing to increasing energy demands, significant energy-related issues remain to be solved. Efforts aimed at reducing the amount of energy loss in electric/electronic systems are essential for reducing energy consumption and protecting the environment. Here, we design an energy-loss return gate system that reduces energy loss from electric/electronic systems by utilizing the polarization of liquid dielectrics. The use of a liquid dielectric material in the energy-loss return gate generates electrostatic potential energy while reducing the dielectric loss of the electric/electronic system. Hence, an energy-loss return gate can make breakthrough impacts possible by amplifying energy-harvesting efficiency, lowering the power consumption of electronics, and storing the returned energy. Our study indicates the potential for enhancing energy-harvesting technologies for electric/electronics systems, while increasing the widespread development of these systems.
Accessing valley degree of freedom in bulk Tin(II) sulfide at room temperature
Authors: Lin Shuren , Carvalho Alexandra , Yan Shancheng , Li Roger , Kim Sujung , Rodin Aleksandr , Carvalho Lídia , Chan Emory M. , Wang Xi , Castro Neto Antonio H. , Yao Jie 
Published: April 2018

AbstractThe field of valleytronics has promised greater control of electronic and spintronic systems with an additional valley degree of freedom. However, conventional and two-dimensional valleytronic systems pose practical challenges in the utilization of this valley degree of freedom. Here we show experimental evidences of the valley effect in a bulk, ambient, and bias-free model system of Tin(II) sulfide. We elucidate the direct access and identification of different sets of valleys, based primarily on the selectivity in absorption and emission of linearly polarized light by optical reflection/transmission and photoluminescence measurements, and demonstrate strong optical dichroic anisotropy of up to 600% and nominal polarization degrees of up to 96% for the two valleys with band-gap values 1.28 and 1.48 eV, respectively; the ease of valley selection further manifested in their non-degenerate nature. Such discovery enables a new platform for better access and control of valley polarization.
A nanofluidic knot factory based on compression of single DNA in nanochannels
Authors: Amin Susan , Khorshid Ahmed , Zeng Lili , Zimny Philip , Reisner Walter 
Published: April 2018

AbstractKnots form when polymers self-entangle, a process enhanced by compaction with important implications in biological and artificial systems involving chain confinement. In particular, new experimental tools are needed to assess the impact of multiple variables influencing knotting probability. Here, we introduce a nanofluidic knot factory for efficient knot formation and detection. Knots are produced during hydrodynamic compression of single DNA molecules against barriers in a nanochannel; subsequent extension of the chain enables direct assessment of the number of independently evolving knots. Knotting probability increases with chain compression as well as with waiting time in the compressed state. Using a free energy derived from scaling arguments, we develop a knot-formation model that can quantify the effect of interactions and the breakdown of Poisson statistics at high compression. Our model suggests that highly compressed knotted states are stabilized by a decreased free energy as knotted contour contributes a lower self-exclusion derived free energy.
High-sensitivity ion detection at low voltages with current-driven organic electrochemical transistors
Authors: Ghittorelli Matteo , Lingstedt Leona , Romele Paolo , Crăciun N. Irina , Kovács-Vajna Zsolt Miklós , Blom Paul W. M. , Torricelli Fabrizio 
Published: April 2018

AbstractIons dissolved in aqueous media play a fundamental role in plants, animals, and humans. Therefore, the in situ quantification of the ion concentration in aqueous media is gathering relevant interest in several fields including biomedical diagnostics, environmental monitoring, healthcare products, water and food test and control, agriculture industry and security. The fundamental limitation of the state-of-art transistor-based approaches is the intrinsic trade-off between sensitivity, ion concentration range and operating voltage. Here we show a current-driven configuration based on organic electrochemical transistors that overcomes this fundamental limit. The measured ion sensitivity exceeds by one order of magnitude the Nernst limit at an operating voltage of few hundred millivolts. The ion sensitivity normalized to the supply voltage is larger than 1200 mV V−1 dec−1, which is the largest value ever reported for ion-sensitive transistors. The proposed approach is general and can be extended to any transistor technology, thus opening opportunities for high-performance bioelectronics.
A novel autophagy enhancer as a therapeutic agent against metabolic syndrome and diabetes
Authors: Lim Hyejin , Lim Yu-Mi , Kim Kook Hwan , Jeon Young Eui , Park Kihyoun , Kim Jinyoung , Hwang Hui-Yun , Lee Dong Jin , Pagire Haushabhau , Kwon Ho Jeong , Ahn Jin Hee , Lee Myung-Shik 
Published: April 2018

AbstractAutophagy is a critical regulator of cellular homeostasis, dysregulation of which is associated with diverse diseases. Here we show therapeutic effects of a novel autophagy enhancer identified by high-throughput screening of a chemical library against metabolic syndrome. An autophagy enhancer increases LC3-I to LC3-II conversion without mTOR inhibition. MSL, an autophagy enhancer, activates calcineurin, and induces dephosphorylation/nuclear translocation of transcription factor EB (TFEB), a master regulator of lysosomal biogenesis and autophagy gene expression. MSL accelerates intracellular lipid clearance, which is reversed by lalistat 2 orTfebknockout. Its administration improves the metabolic profile ofob/obmice and ameliorates inflammasome activation. A chemically modified MSL with increased microsomal stability improves the glucose profile not only ofob/obmice but also of mice with diet-induced obesity. Our data indicate that our novel autophagy enhancer could be a new drug candidate for diabetes or metabolic syndrome with lipid overload.
Resonantly enhanced multiple exciton generation through below-band-gap multi-photon absorption in perovskite nanocrystals
Authors: Manzi Aurora , Tong Yu , Feucht Julius , Yao En-Ping , Polavarapu Lakshminarayana , Urban Alexander S. , Feldmann Jochen 
Published: April 2018

AbstractMulti-photon absorption and multiple exciton generation represent two separate strategies for enhancing the conversion efficiency of light into usable electric power. Targeting below-band-gap and above-band-gap energies, respectively, to date these processes have only been demonstrated independently. Here we report the combined interaction of both nonlinear processes in CsPbBr3 perovskite nanocrystals. We demonstrate nonlinear absorption over a wide range of below-band-gap excitation energies (0.5–0.8 Eg). Interestingly, we discover high-order absorption processes, deviating from the typical two-photon absorption, at specific energetic positions. These energies are associated with a strong enhancement of the photoluminescence intensity by up to 105. The analysis of the corresponding energy levels reveals that the observed phenomena can be ascribed to the resonant creation of multiple excitons via the absorption of multiple below-band-gap photons. This effect may open new pathways for the efficient conversion of optical energy, potentially also in other semiconducting materials.
Stable transformation of Babesia bigemina and Babesia bovis using a single transfection plasmid
Authors: Silva Marta G. , Knowles Donald P. , Mazuz Monica L. , Cooke Brian M. , Suarez Carlos E. 
Published: April 2018

AbstractBabesia bigemina and Babesia bovis, are the two major causes of bovine babesiosis, a global neglected disease in need of improved methods of control. Here, we describe a shared method for the stable transfection of these two parasites using electroporation and blasticidin/blasticidin deaminase as a selectable marker. Stably transfected B. bigemina and B. bovis were obtained using a common transfection plasmid targeting the enhanced green fluorescent protein-BSD (egfp-bsd) fusion gene into the elongation factor-1α (ef-1α) locus of B. bigemina and B. bovis under the control of the B. bigemina ef-1α promoter. Sequencing, Southern blotting, immunoblotting and immunofluorescence analysis of parasite-infected red blood cells, demonstrated that the egfp-bsd gene was expressed and stably integrated solely into the ef-1α locus of both, B. bigemina and B. bovis. Interestingly, heterologous B. bigemina ef-1α sequences were able to drive integration into the B. bovis genome by homologous recombination, and the stably integrated B. bigemina ef-1α-A promoter is fully functional in B. bovis. Collectively, the data provides a new tool for genetic analysis of these parasites, and suggests that the development of vaccine platform delivery systems based on transfected B. bovis and B. bigemina parasites using homologous and heterologous promoters is feasible.
Analysis of HIV-1 envelope evolution suggests antibody-mediated selection of common epitopes among Chinese former plasma donors from a narrow-source outbreak
Authors: Andrews Sophie M. , Zhang Yonghong , Dong Tao , Rowland-Jones Sarah L. , Gupta Sunetra , Esbjörnsson Joakim 
Published: April 2018

AbstractThe HIV-1 envelope mutates rapidly to evade recognition and killing, and is a major target of humoral immune responses and vaccine development. Identification of common epitopes for vaccine development have been complicated by genetic variation on both virus and host levels. We studied HIV-1 envelopegp120evolution in 12 Chinese former plasma donors infected with a purportedly single founder virus, with the aim of identifying common antibody epitopes under immune selection. We found five amino acid sites under significant positive selection in ≥50% of the study participants, and 22 sites consistent with antibody-mediated selection. Despite strong selection pressure, some sites housed a limited repertoire of amino acids. Structural modelling revealed that most of the variable amino acid sites were located on the exposed distal edge of the Gp120 trimer, whilst invariant sites clustered within the centre of the protein complex. Two sites, flanking the V3 hypervariable loop, represent novel antibody sites. Analysis of HIV-1 evolution in hosts infected with a narrow-source virus may provide insight and novel understanding of common epitopes under antibody-mediated selection. If verified in functional studies, such epitopes could be suitable as targets in vaccine development.
Community Detection in Complex Networks via Clique Conductance
Authors: Lu Zhenqi , Wahlström Johan , Nehorai Arye 
Published: April 2018

AbstractNetwork science plays a central role in understanding and modeling complex systems in many areas including physics, sociology, biology, computer science, economics, politics, and neuroscience. One of the most important features of networks is community structure, i.e., clustering of nodes that are locally densely interconnected. Communities reveal the hierarchical organization of nodes, and detecting communities is of great importance in the study of complex systems. Most existing community-detection methods consider low-order connection patterns at the level of individual links. But high-order connection patterns, at the level of small subnetworks, are generally not considered. In this paper, we develop a novel community-detection method based on cliques, i.e., local complete subnetworks. The proposed method overcomes the deficiencies of previous similar community-detection methods by considering the mathematical properties of cliques. We apply the proposed method to computer-generated graphs and real-world network datasets. When applied to networks with known community structure, the proposed method detects the structure with high fidelity and sensitivity. When applied to networks with no a priori information regarding community structure, the proposed method yields insightful results revealing the organization of these complex networks. We also show that the proposed method is guaranteed to detect near-optimal clusters in the bipartition case.
Poultry hatcheries as potential reservoirs for antimicrobial-resistant Escherichia coli: A risk to public health and food safety
Authors: Osman Kamelia M. , Kappell Anthony D. , Elhadidy Mohamed , ElMougy Fatma , El-Ghany Wafaa A. Abd , Orabi Ahmed , Mubarak Aymen S. , Dawoud Turki M. , Hemeg Hassan A. , Moussa Ihab M. I. , Hessain Ashgan M. , Yousef Hend M. Y. 
Published: April 2018

AbstractHatcheries have the power to spread antimicrobial resistant (AMR) pathogens through the poultry value chain because of their central position in the poultry production chain. Currently, no information is available about the presence of AMREscherichia colistrains and the antibiotic resistance genes (ARGs) they harbor within hatchezries. Therefore, this study aimed to investigate the possible involvement of hatcheries in harboring hemolytic AMRE.coli. Serotyping of the 65 isolated hemolyticE.colirevealed 15 serotypes with the ability to produce moderate biofilms, and shared susceptibility to cephradine and fosfomycin and resistance to spectinomycin. The most common β-lactam resistance gene wasblaTEM, followed byblaOXA-1,blaMOX-like,blaCIT-like,blaSHVandblaFOX. Hierarchical clustering ofE.coliisolates based on their phenotypic and genotypic profiles revealed separation of the majority of isolates from hatchlings and the hatchery environments, suggesting that hatchling and environmental isolates may have different origins. The high frequency of β-lactam resistance genes in AMRE.colifrom chick hatchlings indicates that hatcheries may be a reservoir of AMRE.coliand can be a major contributor to the increased environmental burden of ARGs posing an eminent threat to poultry and human health.
Bumblebee olfactory learning affected by task allocation but not by a trypanosome parasite
Authors: Martin Callum D. , Fountain Michelle T. , Brown Mark J. F. 
Published: April 2018

AbstractParasites can induce behavioural changes in their host organisms. Several parasite species are known to infect bumblebees, an important group of pollinators. Task allocation within bumblebee colonies can also cause differences in behaviour. Thus, task allocation may lead to context-dependent impacts of parasites on host behaviour. This study usesBombus terrestrisand its gut trypanosomeCrithidia bombi, to investigate the effects of parasitism, task allocation (foraging or nest-work) and their interactions, on olfactory learning. Prior to undergoing the olfactory learning task, bees were orally infected with a field-realistic dose ofC. bombi, and observed to determine task allocation. Parasitism did not significantly affect olfactory learning, but task allocation did, with foragers being significantly more likely to learn than nest bees. There was no significant interaction between parasitism and task. These results suggest thatC. bombiis unlikely to affect pollination services via changes in olfactory learning of its host if bees are under no environmental or nutritional stress. However, wild and commercial colonies are likely to face such stressors. Future studies in the field are needed to extrapolate our results to real world effects.
Implementation of a Toffoli gate using an array of coupled cavities in a single step
Authors: Cao Y. , Wang G. C. , Liu H. D. , Sun C. F. 
Published: April 2018

AbstractThe Toffoli gate (controlled-controlled-NOT gate) is one typical three-qubit gate, it plus a Hadamard gate form a universal set of gates in quantum computation. We present an efficient method to implement the Toffoli gate using an array of coupled cavities with one three-level atom in each cavity. The large detuning between atoms and classical (quantum) fields plays an important role and the gate is implemented in one-step. The quantum information is encoded into the low-lying states of identical atoms and it is convenient to address qubit individually. Based on the Markovian master equation, it is shown that the scheme to implement the Toffoli gate is robust against the decoherence.
Bilayer synergetic coupling double negative acoustic metasurface and cloak
Authors: Ma Fuyin , Huang Meng , Xu Yicai , Wu Jiu Hui 
Published: April 2018

AbstractIn this paper, we propose a bilayer plate-type lightweight double negative metasurface based on a new synergetic coupling design concept, by which the perfect absorption, double negative bands, free manipulation of phase shifts with a 2π span and acoustic cloak can be successively realized. Firstly, the synergetic behavior between resonant and anti-resonant plates is presented to construct a bilayer unit in which each component respectively provides a pre-defined function in realizing the perfect absorption. Based on this bilayer structure, a double negative band with simultaneously negative effective mass density and bulk modulus is obtained, which, as a metasurface, can obtain continuous phase shifts almost completely covering a 2π range, thus facilitating the design of a three-dimensional (3D) acoustic cloak. In addition, based on this strong sound absorption concept, a two-dimensional (2D) omnidirectional broadband acoustical dark skin, covering between 800 to 6000 Hz, is also demonstrated through the proposed bilayer plate-type structure form. The proposed design concepts and metasurfaces have widespread potential application values in strong sound attenuation, filtering, superlens, imaging, cloak, and extraordinary wave steering, in which the attributes of strong absorption, double negative parameters or continuous phase shifts with full 2π span are required to realize the expected extraordinary physical features.