bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rotational symmetry breaking in the topological superconductor SrxBi2Se3 probed by upper-critical field experiments
Authors: Pan Y. , Nikitin A. M. , Araizi G. K. , Huang Y. K. , Matsushita Y. , Naka T. , de Visser A. 
Published: June 2016

AbstractRecently it was demonstrated that Sr intercalation provides a new route to induce superconductivity in the topological insulator Bi2Se3. Topological superconductors are predicted to be unconventional with an odd-parity pairing symmetry. An adequate probe to test for unconventional superconductivity is the upper critical field,Bc2. For a standard BCS layered superconductorBc2shows an anisotropy when the magnetic field is applied parallel and perpendicular to the layers, but is isotropic when the field is rotated in the plane of the layers. Here we report measurements of the upper critical field of superconducting SrxBi2Se3crystals (Tc = 3.0 K). Surprisingly, field-angle dependent magnetotransport measurements reveal a large anisotropy ofBc2when the magnet field is rotated in the basal plane. The large two-fold anisotropy, while six-fold is anticipated, cannot be explained with the Ginzburg-Landau anisotropic effective mass model or flux flow induced by the Lorentz force. The rotational symmetry breaking ofBc2indicates unconventional superconductivity with odd-parity spin-triplet Cooper pairs (Δ4-pairing) recently proposed for rhombohedral topological superconductors, or might have a structural nature, such as self-organized stripe ordering of Sr atoms.
Electroacupuncture ameliorates memory impairments by enhancing oligodendrocyte regeneration in a mouse model of prolonged cerebral hypoperfusion
Authors: Ahn Sung Min , Kim Yu Ri , Kim Ha Neui , Shin Yong-Il , Shin Hwa Kyoung , Choi Byung Tae 
Published: June 2016

AbstractWe modeled prolonged cerebral hypoperfusion in mice using bilateral common carotid artery stenosis (BCAS) and electroacupuncture (EA) stimulation was applied at two acupoints, Baihui (GV20) and Dazhui (GV14). In behavioral tests of memory, BCAS produced impairments in spatial and short-term memory in mice that were attenuated by therapeutic EA stimulation. Therapeutic use of EA in BCAS also enhanced oligodendrocyte (OL) differentiation from oligodendrocyte precursor cells (OPCs), in association with white matter improvements in the corpus callosum (CC). In PCR analyses of growth factor gene expression, significant positive changes in 3 genes were observed following EA stimulation in BCAS, and here we highlight alterations in neurotrophin-4/5 (NT4/5). We confirmed EA-mediated positive changes in the expression of NT4/5 and its receptor, tyrosine receptor kinase B (TrkB). Treatment of naïve and BCAS + EA animals with a selective TrkB antagonist, ANA-12, produced losses of myelin and cognitive function that were ameliorated by EA therapy. Moreover, following BCAS we observed an EA-dependent increase in phospho-activated CREB (a downstream mediator of NT4/5-TrkB signaling) in OPCs and OLs of the CC. Our results suggest that EA stimulation promotes the recovery of memory function following white matter injury via a mechanism that promotes oligodendrocyte regeneration and involves NT4/5-TrkB signaling.
Pubertal development in healthy children is mirrored by DNA methylation patterns in peripheral blood
Authors: Almstrup Kristian , Lindhardt Johansen Marie , Busch Alexander S. , Hagen Casper P. , Nielsen John E. , Petersen Jørgen Holm , Juul Anders 
Published: June 2016

AbstractPuberty marks numerous physiological processes which are initiated by central activation of the hypothalamic–pituitary–gonadal axis, followed by development of secondary sexual characteristics. To a large extent, pubertal timing is heritable, but current knowledge of genetic polymorphisms only explains few months in the large inter-individual variation in the timing of puberty. We have analysed longitudinal genome-wide changes in DNA methylation in peripheral blood samples (n = 102) obtained from 51 healthy children before and after pubertal onset. We show that changes in single methylation sites are tightly associated with physiological pubertal transition and altered reproductive hormone levels. These methylation sites cluster in and around genes enriched for biological functions related to pubertal development. Importantly, we identified that methylation of the genomic region containing the promoter of TRIP6 was co-ordinately regulated as a function of pubertal development. In accordance, immunohistochemistry identified TRIP6 in adult, but not pre-pubertal, testicular Leydig cells and circulating TRIP6 levels doubled during puberty. Using elastic net prediction models, methylation patterns predicted pubertal development more accurately than chronological age. We demonstrate for the first time that pubertal attainment of secondary sexual characteristics is mirrored by changes in DNA methylation patterns in peripheral blood. Thus, modulations of the epigenome seem involved in regulation of the individual pubertal timing.
New insights about pilus formation in gut-adapted Lactobacillus rhamnosus GG from the crystal structure of the SpaA backbone-pilin subunit
Authors: Chaurasia Priyanka , Pratap Shivendra , von Ossowski Ingemar , Palva Airi , Krishnan Vengadesan 
Published: June 2016

AbstractThus far, all solved structures of pilin-proteins comprising sortase-assembled pili are from pathogenic genera and species. Here, we present the first crystal structure of a pilin subunit (SpaA) from a non-pathogen host (Lactobacillus rhamnosus GG). SpaA consists of two tandem CnaB-type domains, each with an isopeptide bond and E-box motif. Intriguingly, while the isopeptide bond in the N-terminal domain forms between lysine and asparagine, the one in the C-terminal domain atypically involves aspartate. We also solved crystal structures of mutant proteins where residues implicated in forming isopeptide bonds were replaced. Expectedly, the E-box-substituted E139A mutant lacks an isopeptide bond in the N-terminal domain. However, the C-terminal E269A substitution gave two structures; one of both domains with their isopeptide bonds present and another of only the N-terminal domain, but with an unformed isopeptide bond and significant conformational changes. This latter crystal structure has never been observed for any other Gram-positive pilin. Notably, the C-terminal isopeptide bond still forms in D295N-substituted SpaA, irrespective of E269 being present or absent. Although E-box mutations affect SpaA proteolytic and thermal stability, a cumulative effect perturbing normal pilus polymerization was unobserved. A model showing the polymerized arrangement of SpaA within the SpaCBA pilus is proposed.
SARS Coronavirus Fusion Peptide-Derived Sequence Suppresses Collagen-Induced Arthritis in DBA/1J Mice
Authors: Shen Zu T. , Sigalov Alexander B. 
Published: June 2016

AbstractDuring the co-evolution of viruses and their hosts, the viruses have evolved numerous strategies to counter and evade host antiviral immune responses in order to establish a successful infection, replicate and persist in the host. Recently, based on our model of immune signaling, the Signaling Chain HOmoOLigomerization (SCHOOL) model, we suggested specific molecular mechanisms used by different viruses such as severe acute respiratory syndrome coronavirus (SARS-CoV) to modulate the host immune response mediated by members of the family of multichain immune recognition receptors (MIRRs). This family includes T cell receptor (TCR) that is critically involved in immune diseases such as autoimmune arthritis. In the present study, we provide compelling experimental in vivo evidence in support of our hypothesis. Using the SCHOOL approach and the SARS-CoV fusion peptide sequence, we rationally designed a novel immunomodulatory peptide that targets TCR. We showed that this peptide ameliorates collagen-induced arthritis in DBA/1J mice and protects against bone and cartilage damage. Incorporation of the peptide into self-assembling lipopeptide nanoparticles that mimic native human high density lipoproteins significantly increases peptide dosage efficacy. Together, our data further confirm that viral immune evasion strategies that target MIRRs can be transferred to therapeutic strategies that require similar functionalities.
Virus-derived small RNAs in the penaeid shrimp Fenneropenaeus chinensis during acute infection of the DNA virus WSSV
Authors: Liu Chengzhang , Li Fuhua , Sun Yumiao , Zhang Xiaojun , Yuan Jianbo , Yang Hui , Xiang Jianhai 
Published: June 2016

AbstractSmall interfering RNAs (siRNAs) and microRNAs (miRNAs) are two classes of small RNAs (sRNAs) that are critical for virus-host interplay via the RNA interference (RNAi) pathway. One virus-derived siRNA and numerous miRNAs has been reported for the double-stranded DNA virus white spot syndrome virus (WSSV), however, the expression profiles of these different types of sRNAs have not been assessed. Here, by sequencing the sRNAs and mRNAs of WSSV-infected Chinese shrimp (Fenneropenaeus chinensis), we found that the viral transcripts were universally targeted by WSSV-derived siRNAs, supporting a pivotal role for RNAi in the anti-viral immunity of shrimp. The genesis of WSSV-derived siRNAs was associated with long RNA structures. Moreover, by separating miRNAs from siRNAs, 12 WSSV miRNAs were identified. Investigation of conserved viral miRNA targets in different host species indicated the involvement of viral miRNAs in host immune responses. Collectively, our data provide new insights into the role of the RNAi pathway in the interplay between DNA viruses and crustaceans.
Epigenetic repression of ribosomal RNA transcription by ROCK-dependent aberrant cytoskeletal organization
Authors: Wu Tse-Hsiang , Kuo Yuan-Yeh , Lee Hsiao-Hui , Kuo Jean-Cheng , Ou Meng-Hsin , Chang Zee-Fen 
Published: June 2016

AbstractIt is known that ribosomal RNA (rRNA) synthesis is regulated by cellular energy and proliferation status. In this study, we investigated rRNA gene transcription in response to cytoskeletal stress. Our data revealed that the cell shape constrained by isotropic but not elongated micropatterns in HeLa cells led to a significant reduction in rRNA transcription dependent on ROCK. Expression of a dominant-active form of ROCK also repressed rRNA transcription. Isotropic constraint and ROCK over-activation led to different types of aberrant F-actin organization, but their suppression effects on rRNA transcription were similarly reversed by inhibition of histone deacetylase (HDAC) or overexpression of a dominant negative form of Nesprin, which shields the signal transmitted from actin filament to the nuclear interior. We further showed that the binding of HDAC1 to the active fraction of rDNA genes is increased by ROCK over-activation, thus reducing H3K9/14 acetylation and suppressing transcription. Our results demonstrate an epigenetic control of active rDNA genes that represses rRNA transcription in response to the cytoskeletal stress.
Functional map of arrestin binding to phosphorylated opsin, with and without agonist
Authors: Peterhans Christian , Lally Ciara C. M. , Ostermaier Martin K. , Sommer Martha E. , Standfuss Jörg 
Published: June 2016

AbstractArrestins desensitize G protein-coupled receptors (GPCRs) and act as mediators of signalling. Here we investigated the interactions of arrestin-1 with two functionally distinct forms of the dim-light photoreceptor rhodopsin. Using unbiased scanning mutagenesis we probed the individual contribution of each arrestin residue to the interaction with the phosphorylated apo-receptor (Ops-P) and the agonist-bound form (Meta II-P). Disruption of the polar core or displacement of the C-tail strengthened binding to both receptor forms. In contrast, mutations of phosphate-binding residues (phosphosensors) suggest the phosphorylated receptor C-terminus binds arrestin differently for Meta II-P and Ops-P. Likewise, mutations within the inter-domain interface, variations in the receptor-binding loops and the C-edge of arrestin reveal different binding modes. In summary, our results indicate that arrestin-1 binding to Meta II-P and Ops-P is similarly dependent on arrestin activation, although the complexes formed with these two receptor forms are structurally distinct.
Azithromycin induces anti-viral effects in cultured bronchial epithelial cells from COPD patients
Authors: Menzel Mandy , Akbarshahi Hamid , Bjermer Leif , Uller Lena 
Published: June 2016

AbstractRhinovirus infection is a major cause of chronic obstructive pulmonary disease (COPD) exacerbations and may contribute to the development into severe stages of COPD. The macrolide antibiotic azithromycin may exert anti-viral actions and has been reported to reduce exacerbations in COPD. However, little is known about its anti-viral actions on bronchial epithelial cells at clinically relevant concentrations. Primary bronchial epithelial cells from COPD donors and healthy individuals were treated continuously with azithromycin starting 24 h before infection with rhinovirus RV16. Expression of interferons, RIG-I like helicases, pro-inflammatory cytokines and viral load were analysed. Azithromycin transiently increased expression of IFNβ and IFNλ1 and RIG-I like helicases in un-infected COPD cells. Further, azithromycin augmented RV16-induced expression of interferons and RIG-I like helicases in COPD cells but not in healthy epithelial cells. Azithromycin also decreased viral load. However, it only modestly altered RV16-induced pro-inflammatory cytokine expression. Adding budesonide did not reduce interferon-inducing effects of azithromycin. Possibly by inducing expression of RIG-I like helicases, azithromycin increased rhinovirus-induced expression of interferons in COPD but not in healthy bronchial epithelium. These effects would reduce bronchial viral load, supporting azithromycin’s emerging role in prevention of exacerbations of COPD.
Changes in cerebral metabolites in obstructive sleep apnea: a systemic review and meta-analysis
Authors: Xia Yunyan , Fu Yiqun , Xu Huajun , Guan Jian , Yi Hongliang , Yin Shankai 
Published: June 2016

AbstractCognitive impairment is associated with changes in cerebral metabolites in patients with obstructive sleep apnea (OSA). Several studies have used magnetic resonance spectroscopy (MRS) to detect variations in cerebral metabolites; however, the results have been inconsistent. This meta-analysis summarizes the differences in cerebral metabolites between patients with OSA and controls. Two electronic databases, PubMed and Embase, were searched for articles (published before March 31, 2016) describing studies that used MRS to evaluate the cerebral metabolite changes. The overall effects were measured using the weighted mean difference with a 95% confidence interval. Subgroup analysis and sensitivity analysis were used to explore the sources of between-study heterogeneity and the stability of the results. Publication bias was also evaluated. Thirteen studies were ultimately included. In the hippocampus, the N-acetylaspartate (NAA)/creatine ratio was lower in patients with OSA. In the frontal lobe, only the NAA/choline ratio was lower in patients with OSA. Cerebral metabolites are significantly altered in the hippocampus in patients with OSA. Further clinical studies are needed to explore the underlying mechanisms between OSA and the changes in cerebral metabolites in the brain.
Adaptation to second order stimulus features by electrosensory neurons causes ambiguity
Authors: Zhang Zhubo D. , Chacron Maurice J. 
Published: June 2016

AbstractUnderstanding the coding strategies used to process sensory input remains a central problem in neuroscience. Growing evidence suggests that sensory systems process natural stimuli efficiently by ensuring a close match between neural tuning and stimulus statistics through adaptation. However, adaptation causes ambiguity as the same response can be elicited by different stimuli. The mechanisms by which the brain resolves ambiguity remain poorly understood. Here we investigated adaptation in electrosensory pyramidal neurons within different parallel maps in the weakly electric fish Apteronotus leptorhynchus. In response to step increases in stimulus variance, we found that pyramidal neurons within the lateral segment (LS) displayed strong scale invariant adaptation whereas those within the centromedial segment (CMS) instead displayed weaker degrees of scale invariant adaptation. Signal detection analysis revealed that strong adaptation in LS neurons significantly reduced stimulus discriminability. In contrast, weaker adaptation displayed by CMS neurons led to significantly lesser impairment of discriminability. Thus, while LS neurons display adaptation that is matched to natural scene statistics, thereby optimizing information transmission, CMS neurons instead display weaker adaptation and would instead provide information about the context in which these statistics occur. We propose that such a scheme is necessary for decoding by higher brain structures.
A new strategy for exploring the hierarchical structure of cancers by adaptively partitioning functional modules from gene expression network
Authors: Xu Junmei , Jing Runyu , Liu Yuan , Dong Yongcheng , Wen Zhining , Li Menglong 
Published: June 2016

AbstractThe interactions among the genes within a disease are helpful for better understanding the hierarchical structure of the complex biological system of it. Most of the current methodologies need the information of known interactions between genes or proteins to create the network connections. However, these methods meet the limitations in clinical cancer researches because different cancers not only share the common interactions among the genes but also own their specific interactions distinguished from each other. Moreover, it is still difficult to decide the boundaries of the sub-networks. Therefore, we proposed a strategy to construct a gene network by using the sparse inverse covariance matrix of gene expression data and divide it into a series of functional modules by an adaptive partition algorithm. The strategy was validated by using the microarray data of three cancers and the RNA-sequencing data of glioblastoma. The different modules in the network exhibited specific functions in cancers progression. Moreover, based on the gene expression profiles in the modules, the risk of death was well predicted in the clustering analysis and the binary classification, indicating that our strategy can be benefit for investigating the cancer mechanisms and promoting the clinical applications of network-based methodologies in cancer researches.
Circularly polarized laser emission induced in isotropic and achiral dye systems
Authors: Cerdán Luis , García-Moreno Sara , Costela Angel , García-Moreno Inmaculada , de la Moya Santiago 
Published: June 2016

AbstractThe production of efficient, tunable, and switchable circularly polarized laser emission would have far reaching implications in optical communications or biophotonics. In this work, it is demonstrated the direct generation of circularly polarized (CP) laser emission in achiral and isotropic dye laser systems without the use of extracavity polarizing elements, and without resorting to chiral dyes, chiral liquid crystal matrices, or interferometric methods. The origin of this ellipticity arises from the dynamic birefringence induced by the strong and polarized laser pumping and the subsequent orientation anisotropy of the excited molecular dipoles. A complete polarimetric characterization of the polarization state of conventional dye laser oscillators as a function of different experimental parameters is performed and it is shown that the generated light always possesses a certain level of circularity that changes in a distinctive way with pump energy and polarization. These results demonstrate that it is possible to generate and modulate CP laser light from efficient and photostable conventional laser dyes.
Heralded quantum repeater based on the scattering of photons off single emitters using parametric down-conversion source
Authors: Song Guo-Zhu , Wu Fang-Zhou , Zhang Mei , Yang Guo-Jian 
Published: June 2016

AbstractQuantum repeater is the key element in quantum communication and quantum information processing. Here, we investigate the possibility of achieving a heralded quantum repeater based on the scattering of photons off single emitters in one-dimensional waveguides. We design the compact quantum circuits for nonlocal entanglement generation, entanglement swapping and entanglement purification and discuss the feasibility of our protocols with current experimental technology. In our scheme, we use a parametric down-conversion source instead of ideal single-photon sources to realize the heralded quantum repeater. Moreover, our protocols can turn faulty events into the detection of photon polarization and the fidelity can reach 100% in principle. Our scheme is attractive and scalable, since it can be realized with artificial solid-state quantum systems. With developed experimental technique on controlling emitter-waveguide systems, the repeater may be very useful in long-distance quantum communication.
Formation of a series of stable pillar[5]arene-based pseudo[1]-rotaxanes and their [1]rotaxanes in the crystal state
Authors: Han Ying , Huo Gui-Fei , Sun Jing , Xie Ju , Yan Chao-Guo , Zhao Yue , Wu Xuan , Lin Chen , Wang Leyong 
Published: June 2016

AbstractA series of mono-amide-functionalized pillar[5]arenes with different lengths of N-ω-aminoalkyl groups as the side chain on the rim were designed and synthesized, which all formed pseudo[1]rotaxanes in the crystal state. And these pseudo[1]rotaxanes could be transformed into [1]rotaxanes or open forms in the crystal state. In addition, they were also studied in solution by 1H NMR spectroscopy.
Spontaneous mutations in Streptococcus pyogenes isolates from streptococcal toxic shock syndrome patients play roles in virulence
Authors: Ikebe Tadayoshi , Matsumura Takayuki , Nihonmatsu Hisako , Ohya Hitomi , Okuno Rumi , Mitsui Chieko , Kawahara Ryuji , Kameyama Mitsuhiro , Sasaki Mari , Shimada Naomi , Ato Manabu , Ohnishi Makoto 
Published: June 2016

AbstractStreptococcus pyogenes(group AStreptococcus; GAS) is a widespread human pathogen and causes streptococcal toxic shock syndrome (STSS). STSS isolates have been previously shown to have high frequency mutations in thecsrS/csrR(covS/covR) and/orrgg(ropB) genes, which are negative regulators of virulence. However, these mutations were found at somewhat low frequencies inemm1-genotyped isolates, the most prevalent STSS genotype. In this study, we sought to detect causal mutations of enhanced virulence inemm1isolates lacking mutation(s) in thecsrS/csrRandrgggenes. Three mutations associated with elevated virulence were found in thesic(a virulence gene) promoter, thecsrRpromoter and therocAgene (acsrRpositive regulator).In vivocontribution of thesicpromoter androcAmutations to pathogenicity and lethality was confirmed in a GAS mouse model. Frequency of thesicpromoter mutation was significantly higher in STSSemm1isolates than in non-invasive STSS isolates; therocAgene mutation frequency was not significantly different among STSS and non-STSS isolates. STSSemm1isolates possessed a high frequency mutation in thesicpromoter. Thus, this mutation may play a role in the dynamics of virulence and STSS pathogenesis.