bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultra-strong nonlinear optical processes and trigonal warping in MoS2 layers
Authors: Säynätjoki Antti , Karvonen Lasse , Rostami Habib , Autere Anton , Mehravar Soroush , Lombardo Antonio , Norwood Robert A. , Hasan Tawfique , Peyghambarian Nasser , Lipsanen Harri , Kieu Khanh , Ferrari Andrea C. , Polini Marco , Sun Zhipei 
Published: October 2017

AbstractNonlinear optical processes, such as harmonic generation, are of great interest for various applications, e.g., microscopy, therapy, and frequency conversion. However, high-order harmonic conversion is typically much less efficient than low-order, due to the weak intrinsic response of the higher-order nonlinear processes. Here we report ultra-strong optical nonlinearities in monolayer MoS2 (1L-MoS2): the third harmonic is 30 times stronger than the second, and the fourth is comparable to the second. The third harmonic generation efficiency for 1L-MoS2 is approximately three times higher than that for graphene, which was reported to have a large χ(3). We explain this by calculating the nonlinear response functions of 1L-MoS2 with a continuum-model Hamiltonian and quantum mechanical diagrammatic perturbation theory, highlighting the role of trigonal warping. A similar effect is expected in all other transition-metal dichalcogenides. Our results pave the way for efficient harmonic generation based on layered materials for applications such as microscopy and imaging.
Targeted delivery of celastrol to mesangial cells is effective against mesangioproliferative glomerulonephritis
Authors: Guo Ling , Luo Shi , Du Zhengwu , Zhou Meiling , Li Peiwen , Fu Yao , Sun Xun , Huang Yuan , Zhang Zhirong 
Published: October 2017

AbstractMesangial cells-mediated glomerulonephritis is a frequent cause of end-stage renal disease. Here, we show that celastrol is effective in treating both reversible and irreversible mesangioproliferative glomerulonephritis in rat models, but find that its off-target distributions cause severe systemic toxicity. We thus target celastrol to mesangial cells using albumin nanoparticles. Celastrol-albumin nanoparticles crosses fenestrated endothelium and accumulates in mesangial cells, alleviating proteinuria, inflammation, glomerular hypercellularity, and excessive extracellular matrix deposition in rat anti-Thy1.1 nephritis models. Celastrol-albumin nanoparticles presents lower drug accumulation than free celastrol in off-target organs and tissues, thereby minimizing celastrol-related systemic toxicity. Celastrol-albumin nanoparticles thus represents a promising treatment option for mesangioproliferative glomerulonephritis and similar glomerular diseases.
Picosecond orientational dynamics of water in living cells
Authors: Tros Martijn , Zheng Linli , Hunger Johannes , Bonn Mischa , Bonn Daniel , Smits Gertien J. , Woutersen Sander 
Published: October 2017

AbstractCells are extremely crowded, and a central question in biology is how this affects the intracellular water. Here, we use ultrafast vibrational spectroscopy and dielectric-relaxation spectroscopy to observe the random orientational motion of water molecules inside living cells of three prototypical organisms: Escherichia coli, Saccharomyces cerevisiae (yeast), and spores of Bacillus subtilis. In all three organisms, most of the intracellular water exhibits the same random orientational motion as neat water (characteristic time constants ~9 and ~2 ps for the first-order and second-order orientational correlation functions), whereas a smaller fraction exhibits slower orientational dynamics. The fraction of slow intracellular water varies between organisms, ranging from ~20% in E. coli to ~45% in B. subtilis spores. Comparison with the water dynamics observed in solutions mimicking the chemical composition of (parts of) the cytosol shows that the slow water is bound mostly to proteins, and to a lesser extent to other biomolecules and ions.
A novel true random number generator based on a stochastic diffusive memristor
Authors: Jiang Hao , Belkin Daniel , Savel’ev Sergey E. , Lin Siyan , Wang Zhongrui , Li Yunning , Joshi Saumil , Midya Rivu , Li Can , Rao Mingyi , Barnell Mark , Wu Qing , Yang J. Joshua , Xia Qiangfei 
Published: October 2017

AbstractThe intrinsic variability of switching behavior in memristors has been a major obstacle to their adoption as the next generation of universal memory. On the other hand, this natural stochasticity can be valuable for hardware security applications. Here we propose and demonstrate a novel true random number generator utilizing the stochastic delay time of threshold switching in a Ag:SiO2 diffusive memristor, which exhibits evident advantages in scalability, circuit complexity, and power consumption. The random bits generated by the diffusive memristor true random number generator pass all 15 NIST randomness tests without any post-processing, a first for memristive-switching true random number generators. Based on nanoparticle dynamic simulation and analytical estimates, we attribute the stochasticity in delay time to the probabilistic process by which Ag particles detach from a Ag reservoir. This work paves the way for memristors in hardware security applications for the era of the Internet of Things.
A long-range cis-regulatory element for class I odorant receptor genes
Authors: Iwata Tetsuo , Niimura Yoshihito , Kobayashi Chizuru , Shirakawa Daichi , Suzuki Hikoyu , Enomoto Takayuki , Touhara Kazushige , Yoshihara Yoshihiro , Hirota Junji 
Published: October 2017

AbstractIndividual olfactory sensory neurons express a single odorant receptor gene from either class I genes residing in a single cluster on a single chromosome or class II genes spread over multiple clusters on multiple chromosomes. Here, we identify an enhancer element for mouse class I genes, the J element, that is conserved through mammalian species from the platypus to humans. The J element regulates most class I genes expression by exerting an effect over ~ 3 megabases within the whole cluster. Deletion of the trans J element increases the expression frequencies of class I genes from the intact J allele, indicating that the allelic exclusion of class I genes depends on the activity of the J element. Our data reveal a long-range cis-regulatory element that governs the singular class I gene expression and has been phylogenetically preserved to retain a single cluster organization of class I genes in mammals.
All-optical regenerator of multi-channel signals
Authors: Li Lu , Patki Pallavi G. , Kwon Young B. , Stelmakh Veronika , Campbell Brandon D. , Annamalai Muthiah , Lakoba Taras I. , Vasilyev Michael 
Published: October 2017

AbstractOne of the main reasons why nonlinear-optical signal processing (regeneration, logic, etc.) has not yet become a practical alternative to electronic processing is that the all-optical elements with nonlinear input–output relationship have remained inherently single-channel devices (just like their electronic counterparts) and, hence, cannot fully utilise the parallel processing potential of optical fibres and amplifiers. The nonlinear input–output transfer function requires strong optical nonlinearity, e.g. self-phase modulation, which, for fundamental reasons, is always accompanied by cross-phase modulation and four-wave mixing. In processing multiple wavelength-division-multiplexing channels, large cross-phase modulation and four-wave mixing crosstalks among the channels destroy signal quality. Here we describe a solution to this problem: an optical signal processor employing a group-delay-managed nonlinear medium where strong self-phase modulation is achieved without such nonlinear crosstalk. We demonstrate, for the first time to our knowledge, simultaneous all-optical regeneration of up to 16 wavelength-division-multiplexing channels by one device. This multi-channel concept can be extended to other nonlinear-optical processing schemes.
Structural insights into the competitive inhibition of the ATP-gated P2X receptor channel
Authors: Kasuya Go , Yamaura Toshiaki , Ma Xiao-Bo , Nakamura Ryoki , Takemoto Mizuki , Nagumo Hiromitsu , Tanaka Eiichi , Dohmae Naoshi , Nakane Takanori , Yu Ye , Ishitani Ryuichiro , Matsuzaki Osamu , Hattori Motoyuki , Nureki Osamu 
Published: October 2017

AbstractP2X receptors are non-selective cation channels gated by extracellular ATP, and the P2X7 receptor subtype plays a crucial role in the immune and nervous systems. Altered expression and dysfunctions of P2X7 receptors caused by genetic deletions, mutations, and polymorphic variations have been linked to various diseases, such as rheumatoid arthritis and hypertension. Despite the availability of crystal structures of P2X receptors, the mechanism of competitive antagonist action for P2X receptors remains controversial. Here, we determine the crystal structure of the chicken P2X7 receptor in complex with the competitive P2X antagonist, TNP-ATP. The structure reveals an expanded, incompletely activated conformation of the channel, and identified the unique recognition manner of TNP-ATP, which is distinct from that observed in the previously determined human P2X3 receptor structure. A structure-based computational analysis furnishes mechanistic insights into the TNP-ATP-dependent inhibition. Our work provides structural insights into the functional mechanism of the P2X competitive antagonist.
Heterozygous RFX6 protein truncating variants are associated with MODY with reduced penetrance
Authors: Patel Kashyap A. , Kettunen Jarno , Laakso Markku , Stančáková Alena , Laver Thomas W. , Colclough Kevin , Johnson Matthew B. , Abramowicz Marc , Groop Leif , Miettinen Päivi J. , Shepherd Maggie H. , Flanagan Sarah E. , Ellard Sian , Inagaki Nobuya , Hattersley Andrew T. , Tuomi Tiinamaija , Cnop Miriam , Weedon Michael N. 
Published: October 2017

AbstractFinding new causes of monogenic diabetes helps understand glycaemic regulation in humans. To find novel genetic causes of maturity-onset diabetes of the young (MODY), we sequenced MODY cases with unknown aetiology and compared variant frequencies to large public databases. From 36 European patients, we identify two probands with novel RFX6 heterozygous nonsense variants. RFX6 protein truncating variants are enriched in the MODY discovery cohort compared to the European control population within ExAC (odds ratio = 131, P = 1 × 10−4). We find similar results in non-Finnish European (n = 348, odds ratio = 43, P = 5 × 10−5) and Finnish (n = 80, odds ratio = 22, P = 1 × 10−6) replication cohorts. RFX6 heterozygotes have reduced penetrance of diabetes compared to common HNF1A and HNF4A-MODY mutations (27, 70 and 55% at 25 years of age, respectively). The hyperglycaemia results from beta-cell dysfunction and is associated with lower fasting and stimulated gastric inhibitory polypeptide (GIP) levels. Our study demonstrates that heterozygous RFX6 protein truncating variants are associated with MODY with reduced penetrance.
The microbiota continuum along the female reproductive tract and its relation to uterine-related diseases
Authors: Chen Chen , Song Xiaolei , Wei Weixia , Zhong Huanzi , Dai Juanjuan , Lan Zhou , Li Fei , Yu Xinlei , Feng Qiang , Wang Zirong , Xie Hailiang , Chen Xiaomin , Zeng Chunwei , Wen Bo , Zeng Liping , Du Hui , Tang Huiru , Xu Changlu , Xia Yan , Xia Huihua , Yang Huanming , Wang Jian , Wang Jun , Madsen Lise , Brix Susanne , Kristiansen Karsten , Xu Xun , Li Junhua , Wu Ruifang , Jia Huijue 
Published: October 2017

AbstractReports on bacteria detected in maternal fluids during pregnancy are typically associated with adverse consequences, and whether the female reproductive tract harbours distinct microbial communities beyond the vagina has been a matter of debate. Here we systematically sample the microbiota within the female reproductive tract in 110 women of reproductive age, and examine the nature of colonisation by 16S rRNA gene amplicon sequencing and cultivation. We find distinct microbial communities in cervical canal, uterus, fallopian tubes and peritoneal fluid, differing from that of the vagina. The results reflect a microbiota continuum along the female reproductive tract, indicative of a non-sterile environment. We also identify microbial taxa and potential functions that correlate with the menstrual cycle or are over-represented in subjects with adenomyosis or infertility due to endometriosis. The study provides insight into the nature of the vagino-uterine microbiome, and suggests that surveying the vaginal or cervical microbiota might be useful for detection of common diseases in the upper reproductive tract.
Coulomb spin liquid in anion-disordered pyrochlore Tb2Hf2O7
Authors: Sibille Romain , Lhotel Elsa , Ciomaga Hatnean Monica , Nilsen Gøran J. , Ehlers Georg , Cervellino Antonio , Ressouche Eric , Frontzek Matthias , Zaharko Oksana , Pomjakushin Vladimir , Stuhr Uwe , Walker Helen C. , Adroja Devashibhai T. , Luetkens Hubertus , Baines Chris , Amato Alex , Balakrishnan Geetha , Fennell Tom , Kenzelmann Michel 
Published: October 2017

AbstractThe charge ordered structure of ions and vacancies characterizing rare-earth pyrochlore oxides serves as a model for the study of geometrically frustrated magnetism. The organization of magnetic ions into networks of corner-sharing tetrahedra gives rise to highly correlated magnetic phases with strong fluctuations, including spin liquids and spin ices. It is an open question how these ground states governed by local rules are affected by disorder. Here we demonstrate in the pyrochlore Tb2Hf2O7, that the vicinity of the disordering transition towards a defective fluorite structure translates into a tunable density of anion Frenkel disorder while cations remain ordered. Quenched random crystal fields and disordered exchange interactions can therefore be introduced into otherwise perfect pyrochlore lattices of magnetic ions. We show that disorder can play a crucial role in preventing long-range magnetic order at low temperatures, and instead induces a strongly fluctuating Coulomb spin liquid with defect-induced frozen magnetic degrees of freedom.
Binary temporal upconversion codes of Mn2+-activated nanoparticles for multilevel anti-counterfeiting
Authors: Liu Xiaowang , Wang Yu , Li Xiyan , Yi Zhigao , Deng Renren , Liang Liangliang , Xie Xiaoji , Loong Daniel T. B. , Song Shuyan , Fan Dianyuan , All Angelo H. , Zhang Hongjie , Huang Ling , Liu Xiaogang 
Published: October 2017

AbstractOptical characteristics of luminescent materials, such as emission profile and lifetime, play an important role in their applications in optical data storage, document security, diagnostics, and therapeutics. Lanthanide-doped upconversion nanoparticles are particularly suitable for such applications due to their inherent optical properties, including large anti-Stokes shift, distinguishable spectroscopic fingerprint, and long luminescence lifetime. However, conventional upconversion nanoparticles have a limited capacity for information storage or complexity to prevent counterfeiting. Here, we demonstrate that integration of long-lived Mn2+ upconversion emission and relatively short-lived lanthanide upconversion emission in a particulate platform allows the generation of binary temporal codes for efficient data encoding. Precise control of the particle’s structure allows the excitation feasible both under 980 and 808 nm irradiation. We find that the as-prepared Mn2+-doped nanoparticles are especially useful for multilevel anti-counterfeiting with high-throughput rate of authentication and without the need for complex time-gated decoding instrumentation.
Bielectron vortices in two-dimensional Dirac semimetals
Authors: Downing C. A. , Portnoi M. E. 
Published: October 2017

AbstractSearching for new states of matter and unusual quasi-particles in emerging materials and especially low-dimensional systems is one of the major trends in contemporary condensed matter physics. Dirac materials, which host quasi-particles which are described by ultrarelativistic Dirac-like equations, are of a significant current interest from both a fundamental and applied physics perspective. Here we show that a pair of two-dimensional massless Dirac–Weyl fermions can form a bound state independently of the sign of the inter-particle interaction potential, as long as this potential decays at large distances faster than Kepler’s inverse distance law. This leads to the emergence of a new type of energetically favorable quasiparticle: bielectron vortices, which are double-charged and reside at zero-energy. Their bosonic nature allows for condensation and may give rise to Majorana physics without invoking a superconductor. These novel quasi-particles arguably explain a range of poorly understood experiments in gated graphene structures at low doping.
Volcanic suppression of Nile summer flooding triggers revolt and constrains interstate conflict in ancient Egypt
Authors: Manning Joseph G. , Ludlow Francis , Stine Alexander R. , Boos William R. , Sigl Michael , Marlon Jennifer R. 
Published: October 2017

AbstractVolcanic eruptions provide tests of human and natural system sensitivity to abrupt shocks because their repeated occurrence allows the identification of systematic relationships in the presence of random variability. Here we show a suppression of Nile summer flooding via the radiative and dynamical impacts of explosive volcanism on the African monsoon, using climate model output, ice-core-based volcanic forcing data, Nilometer measurements, and ancient Egyptian writings. We then examine the response of Ptolemaic Egypt (305–30 BCE), one of the best-documented ancient superpowers, to volcanically induced Nile suppression. Eruptions are associated with revolt onset against elite rule, and the cessation of Ptolemaic state warfare with their great rival, the Seleukid Empire. Eruptions are also followed by socioeconomic stress with increased hereditary land sales, and the issuance of priestly decrees to reinforce elite authority. Ptolemaic vulnerability to volcanic eruptions offers a caution for all monsoon-dependent agricultural regions, presently including 70% of world population.
Heterogeneous integration for on-chip quantum photonic circuits with single quantum dot devices
Authors: Davanco Marcelo , Liu Jin , Sapienza Luca , Zhang Chen-Zhao , De Miranda Cardoso José Vinícius , Verma Varun , Mirin Richard , Nam Sae Woo , Liu Liu , Srinivasan Kartik 
Published: October 2017

AbstractSingle-quantum emitters are an important resource for photonic quantum technologies, constituting building blocks for single-photon sources, stationary qubits, and deterministic quantum gates. Robust implementation of such functions is achieved through systems that provide both strong light–matter interactions and a low-loss interface between emitters and optical fields. Existing platforms providing such functionality at the single-node level present steep scalability challenges. Here, we develop a heterogeneous photonic integration platform that provides such capabilities in a scalable on-chip implementation, allowing direct integration of GaAs waveguides and cavities containing self-assembled InAs/GaAs quantum dots—a mature class of solid-state quantum emitter—with low-loss Si3N4 waveguides. We demonstrate a highly efficient optical interface between Si3N4 waveguides and single-quantum dots in GaAs geometries, with performance approaching that of devices optimized for each material individually. This includes quantum dot radiative rate enhancement in microcavities, and a path for reaching the non-perturbative strong-coupling regime.
Evidence of a chimpanzee-sized ancestor of humans but a gibbon-sized ancestor of apes
Authors: Grabowski Mark , Jungers William L. 
Published: October 2017

AbstractBody mass directly affects how an animal relates to its environment and has a wide range of biological implications. However, little is known about the mass of the last common ancestor (LCA) of humans and chimpanzees, hominids (great apes and humans), or hominoids (all apes and humans), which is needed to evaluate numerous paleobiological hypotheses at and prior to the root of our lineage. Here we use phylogenetic comparative methods and data from primates including humans, fossil hominins, and a wide sample of fossil primates including Miocene apes from Africa, Europe, and Asia to test alternative hypotheses of body mass evolution. Our results suggest, contrary to previous suggestions, that the LCA of all hominoids lived in an environment that favored a gibbon-like size, but a series of selective regime shifts, possibly due to resource availability, led to a decrease and then increase in body mass in early hominins from a chimpanzee-sized LCA.
Chemical signal activation of an organocatalyst enables control over soft material formation
Authors: Trausel Fanny , Maity Chandan , Poolman Jos M. , Kouwenberg D. S. J. , Versluis Frank , van Esch Jan H. , Eelkema Rienk 
Published: October 2017

AbstractCells can react to their environment by changing the activity of enzymes in response to specific chemical signals. Artificial catalysts capable of being activated by chemical signals are rare, but of interest for creating autonomously responsive materials. We present an organocatalyst that is activated by a chemical signal, enabling temporal control over reaction rates and the formation of materials. Using self-immolative chemistry, we design a deactivated aniline organocatalyst that is activated by the chemical signal hydrogen peroxide and catalyses hydrazone formation. Upon activation of the catalyst, the rate of hydrazone formation increases 10-fold almost instantly. The responsive organocatalyst enables temporal control over the formation of gels featuring hydrazone bonds. The generic design should enable the use of a large range of triggers and organocatalysts, and appears a promising method for the introduction of signal response in materials, constituting a first step towards achieving communication between artificial chemical systems.
Effective purifying selection in ancient asexual oribatid mites
Authors: Brandt Alexander , Schaefer Ina , Glanz Julien , Schwander Tanja , Maraun Mark , Scheu Stefan , Bast Jens 
Published: October 2017

AbstractSex is beneficial in the long term because it can prevent mutational meltdown through increased effectiveness of selection. This idea is supported by empirical evidence of deleterious mutation accumulation in species with a recent transition to asexuality. Here, we study the effectiveness of purifying selection in oribatid mites which have lost sex millions of years ago and diversified into different families and species while reproducing asexually. We compare the accumulation of deleterious nonsynonymous and synonymous mutations between three asexual and three sexual lineages using transcriptome data. Contrasting studies of young asexual lineages, we find evidence for strong purifying selection that is more effective in asexual as compared to sexual oribatid mite lineages. Our results suggest that large populations likely sustain effective purifying selection and facilitate the escape of mutational meltdown in the absence of sex. Thus, sex per se is not a prerequisite for the long-term persistence of animal lineages.
Engineering species-like barriers to sexual reproduction
Authors: Maselko Maciej , Heinsch Stephen C. , Chacón Jeremy M. , Harcombe William R. , Smanski Michael J. 
Published: October 2017

AbstractControlling the exchange of genetic information between sexually reproducing populations has applications in agriculture, eradication of disease vectors, control of invasive species, and the safe study of emerging biotechnology applications. Here we introduce an approach to engineer a genetic barrier to sexual reproduction between otherwise compatible populations. Programmable transcription factors drive lethal gene expression in hybrid offspring following undesired mating events. As a proof of concept, we target theACT1promoter of the model organismSaccharomyces cerevisiaeusing a dCas9-based transcriptional activator. Lethal overexpression of actin results from mating this engineered strain with a strain containing the wild-typeACT1promoter.