bluuebunny/crossref_metadata_2025_split huggingface dataset:
Super-resolution microscopy reveals functional organization of dopamine transporters into cholesterol and neuronal activity-dependent nanodomains
Authors: Rahbek-Clemmensen Troels , Lycas Matthew D. , Erlendsson Simon , Eriksen Jacob , Apuschkin Mia , Vilhardt Frederik , Jørgensen Trine N. , Hansen Freja H. , Gether Ulrik 
Published: September 2017

AbstractDopamine regulates reward, cognition, and locomotor functions. By mediating rapid reuptake of extracellular dopamine, the dopamine transporter is critical for spatiotemporal control of dopaminergic neurotransmission. Here, we use super-resolution imaging to show that the dopamine transporter is dynamically sequestrated into cholesterol-dependent nanodomains in the plasma membrane of presynaptic varicosities and neuronal projections of dopaminergic neurons. Stochastic optical reconstruction microscopy reveals irregular dopamine transporter nanodomains (∼70 nm mean diameter) that were highly sensitive to cholesterol depletion. Live photoactivated localization microscopy shows a similar dopamine transporter membrane organization in live heterologous cells. In neurons, dual-color dSTORM shows that tyrosine hydroxylase and vesicular monoamine transporter-2 are distinctively localized adjacent to, but not overlapping with, the dopamine transporter nanodomains. The molecular organization of the dopamine transporter in nanodomains is reversibly reduced by short-term activation of NMDA-type ionotropic glutamate receptors, implicating dopamine transporter nanodomain distribution as a potential mechanism to modulate dopaminergic neurotransmission in response to excitatory input.
Species-dependent structural polymorphism of Y145Stop prion protein amyloid revealed by solid-state NMR spectroscopy
Authors: Theint Theint , Nadaud Philippe S. , Aucoin Darryl , Helmus Jonathan J. , Pondaven Simon P. , Surewicz Krystyna , Surewicz Witold K. , Jaroniec Christopher P. 
Published: September 2017

AbstractOne of the most puzzling aspects of the prion diseases is the intricate relationship between prion strains and interspecies transmissibility barriers. Previously we have shown that certain fundamental aspects of mammalian prion propagation, including the strain phenomenon and species barriers, can be reproduced in vitro in seeded fibrillization of the Y145Stop prion protein variant. Here, we use solid-state nuclear magnetic resonance spectroscopy to gain atomic level insight into the structural differences between Y145Stop prion protein amyloids from three species: human, mouse, and Syrian hamster. Remarkably, we find that these structural differences are largely controlled by only two amino acids at positions 112 and 139, and that the same residues appear to be key to the emergence of structurally distinct amyloid strains within the same protein sequence. The role of these residues as conformational switches can be rationalized based on a model for human Y145Stop prion protein amyloid, providing a foundation for understanding cross-seeding specificity.
Elucidating the origins of multimode vibrational coherences of polyatomic molecules induced by intense laser fields
Authors: Wei Zhengrong , Li Jialin , Wang Lin , See Soo Teck , Jhon Mark Hyunpong , Zhang Yingfeng , Shi Fan , Yang Minghui , Loh Zhi-Heng 
Published: September 2017

AbstractStrong-field laser–molecule interaction forms much of the basis for initiating and probing ultrafast quantum dynamics. Previous studies aimed at elucidating the origins of vibrational coherences induced by intense laser fields have been confined to diatomic molecules. Furthermore, in all cases examined to date, vibrational wave packet motion is found to be induced by R-selective depletion; wave packet motion launched by bond softening, though theoretically predicted, remains hitherto unobserved. Here we employ the exquisite sensitivity of femtosecond extreme ultraviolet absorption spectroscopy to sub-picometer structural changes to observe both bond softening-induced vibrational wave packets, launched by the interaction of intense laser pulses with iodomethane, as well as multimode vibrational motion of the parent ion produced by strong-field ionization. In addition, we show that signatures of coherent vibrational motion in the time-dependent extreme ultraviolet absorption spectra directly furnish vibronic coupling strengths involving core-level transitions, from which geometrical parameters of transient core-excited states are extracted.
Biogenic manganese oxide nanoparticle formation by a multimeric multicopper oxidase Mnx
Authors: Romano Christine A. , Zhou Mowei , Song Yang , Wysocki Vicki H. , Dohnalkova Alice C. , Kovarik Libor , Paša-Tolić Ljiljana , Tebo Bradley M. 
Published: September 2017

AbstractBacteria that produce Mn oxides are extraordinarily skilled engineers of nanomaterials that contribute significantly to global biogeochemical cycles. Their enzyme-based reaction mechanisms may be genetically tailored for environmental remediation applications or bioenergy production. However, significant challenges exist for structural characterization of the enzymes responsible for biomineralization. The active Mn oxidase in Bacillus sp. PL-12, Mnx, is a complex composed of a multicopper oxidase (MCO), MnxG, and two accessory proteins, MnxE and MnxF. MnxG shares sequence similarity with other, structurally characterized MCOs. MnxE and MnxF have no similarity to any characterized proteins. The ~200 kDa complex has been recalcitrant to crystallization, so its structure is unknown. Here, we show that native mass spectrometry defines the subunit topology and copper binding of Mnx, while high-resolution electron microscopy visualizes the protein and nascent Mn oxide minerals. These data provide critical structural information for understanding Mn biomineralization by such unexplored enzymes.
Boosting the down-shifting luminescence of rare-earth nanocrystals for biological imaging beyond 1500 nm
Authors: Zhong Yeteng , Ma Zhuoran , Zhu Shoujun , Yue Jingying , Zhang Mingxi , Antaris Alexander L. , Yuan Jie , Cui Ran , Wan Hao , Zhou Ying , Wang Weizhi , Huang Ngan F. , Luo Jian , Hu Zhiyuan , Dai Hongjie 
Published: September 2017

AbstractIn vivo fluorescence imaging in the near-infrared region between 1500–1700 nm (NIR-IIb window) affords high spatial resolution, deep-tissue penetration, and diminished auto-fluorescence due to the suppressed scattering of long-wavelength photons and large fluorophore Stokes shifts. However, very few NIR-IIb fluorescent probes exist currently. Here, we report the synthesis of a down-conversion luminescent rare-earth nanocrystal with cerium doping (Er/Ce co-doped NaYbF4 nanocrystal core with an inert NaYF4 shell). Ce doping is found to suppress the up-conversion pathway while boosting down-conversion by ~9-fold to produce bright 1550 nm luminescence under 980 nm excitation. Optimization of the inert shell coating surrounding the core and hydrophilic surface functionalization minimize the luminescence quenching effect by water. The resulting biocompatible, bright 1550 nm emitting nanoparticles enable fast in vivo imaging of blood vasculature in the mouse brain and hindlimb in the NIR-IIb window with short exposure time of 20 ms for rare-earth based probes.
Epithelial Chloride Transport by CFTR Requires TMEM16A
Authors: Benedetto Roberta , Ousingsawat Jiraporn , Wanitchakool Podchanart , Zhang Yong , Holtzman Michael J. , Amaral Margarida , Rock Jason R. , Schreiber Rainer , Kunzelmann Karl 
Published: September 2017

AbstractCystic Fibrosis Transmembrane Conductance Regulator (CFTR) is the secretory chloride/bicarbonate channel in airways and intestine that is activated through ATP binding and phosphorylation by protein kinase A, but fails to operate in cystic fibrosis (CF). TMEM16A (also known as anoctamin 1, ANO1) is thought to function as the Ca2+ activated secretory chloride channel independent of CFTR. Here we report that tissue specific knockout of the TMEM16A gene in mouse intestine and airways not only eliminates Ca2+-activated Cl− currents, but unexpectedly also abrogates CFTR-mediated Cl− secretion and completely abolishes cAMP-activated whole cell currents. The data demonstrate fundamentally new roles of TMEM16A in differentiated epithelial cells: TMEM16A provides a mechanism for enhanced ER Ca2+ store release, possibly engaging Store Operated cAMP Signaling (SOcAMPS) and activating Ca2+ regulated adenylyl cyclases. TMEM16A is shown to be essential for proper activation and membrane expression of CFTR. This intimate regulatory relationship is the cause for the functional overlap of CFTR and Ca2+-dependent chloride transport.
Understanding the differences of the ligand binding/unbinding pathways between phosphorylated and non-phosphorylated ARH1 using molecular dynamics simulations
Authors: Zhu Jingxuan , Lv Yishuo , Han Xiaosong , Xu Dong , Han Weiwei 
Published: September 2017

AbstractADP-ribosylhydrolases (ARH1, ARH2 and ARH3) are a family of enzymes to catalyze ADP-ribosylation, a reversible and covalent post-translational modification (PTM). There are four phosphorylated sites (Tyr-4, Tyr-19, Tyr-20, and Tyr-205) in ARH1. To explore the structural changes and functional impact induced by phosphorylation, molecular dynamics (MD) simulations and steered molecular dynamics (SMD) simulations were performed for the phosphorylated and non-phosphorylated ARH1 with the ligands. MD simulations results indicate that: (1) Glu-25 is more frequently in the α helix group in the phosphorylated state with the adenosine-5-diphosphate-ribosylarginine (ADP-RA) complex (51.56%) than that of the non-phosphorylated state(2.12%); (2) Ser-124 and Ser-264 become less flexible in the phosphorylated state with ADP-RA complex, which helps two residues form hydrogen bonds with ADP-RA; and (3) Tyr-211 is also less flexible in the phosphorylated state with ADP-RA complex, which helps stabilize the cation-π interaction of Y211-R119. All these changes facilitate ADP-RA to bind ARH1. In addition, according to the crystal structure of adenosine-5-diphosphate-ribose (ADP-ribose) in complex with non-phosphorylated and phosphorylated ARH1, the possible unbinding pathways of ADP-ribose from non-phosphorylated and phosphorylated ARH1 were explored respectively using SMD simulations. Our results show that phosphorylated ARH1 has more ordered structures than the non-phosphorylated type.
Population density gratings induced by few-cycle optical pulses in a resonant medium
Authors: Arkhipov R. M. , Pakhomov A. V. , Arkhipov M. V. , Babushkin I. , Demircan A. , Morgner U. , Rosanov N. N. 
Published: September 2017

AbstractCreation, erasing and ultrafast control of population density gratings using few-cycle optical pulses coherently interacting with resonant medium is discussed. In contrast to the commonly used schemes, here the pulses do not need to overlap in the medium, interaction between the pulses is mediated by excitation of polarization waves. We investigate the details of the dynamics arising in such ultrashort pulse scheme and develop an analytical theory demonstrating the importance of the phase memory effects in the dynamics.
Space division multiplexing chip-to-chip quantum key distribution
Authors: Bacco Davide , Ding Yunhong , Dalgaard Kjeld , Rottwitt Karsten , Oxenløwe Leif Katsuo 
Published: September 2017

AbstractQuantum cryptography is set to become a key technology for future secure communications. However, to get maximum benefit in communication networks, transmission links will need to be shared among several quantum keys for several independent users. Such links will enable switching in quantum network nodes of the quantum keys to their respective destinations. In this paper we present an experimental demonstration of a photonic integrated silicon chip quantum key distribution protocols based on space division multiplexing (SDM), through multicore fiber technology. Parallel and independent quantum keys are obtained, which are useful in crypto-systems and future quantum network.
Phosphorylation of FE65 at threonine 579 by GSK3β stimulates amyloid precursor protein processing
Authors: Lee Yat Shing , Chow Wan Ning Vanessa , Lau Kwok-Fai 
Published: September 2017

AbstractExcessive generation of amyloid-β peptide (Aβ) by aberrant proteolysis of amyloid precursor protein (APP) is a key event in Alzheimer's disease (AD) pathogenesis. FE65 is a brain-enriched phospho-adaptor protein that interacts with APP and has been shown to modulate APP processing. However, the mechanism(s) that FE65 alters APP processing is still not fully understood. In the present study, we demonstrate that FE65 is phosphorylated at threonine 579 (T579) by glycogen synthase kinase 3β (GSK3β). Moreover, FE65 T579 phosphorylation potentiates γ- and β-secretases-mediated APP processing and Aβ liberation. Additionally, the phosphorylation suppresses FE65 PTB2 intermolecular dimerization but enhances FE65/APP complex formation. Hence, our findings reveal a novel mechanism that GSK3β stimulates amyloidogenic processing of APP by phosphorylation of FE65 at T579.
Regioselectivity and diastereoselectivity of three-component reaction of α-amino acid, dialkyl acetylenedicarboxylates and 2-arylidene-1,3-indanediones
Authors: Chen Liang , Sun Jing , Huang Ying , Zhang Yu , Yan Chao-Guo 
Published: September 2017

AbstractThe 1,3-dipolar cycloaddition of active azomethine ylide, which were generated in situ from addition reaction of α-amino acids with dialkyl acetylenedicarboxylates, with 2-arylidene-1,3-indanediones showed versatile regioselectivity and diastereoselectivity. The reaction of sarcosine and glycine afforded one kind of functionalized spiro[indene-2,3′-pyrrolidines]. The other primary α-amino acids such as alanine, phenylalanine and leucine gave another kind of regioisomeric spiro[indene-2,3′-pyrrolidines]. The cyclic α-amino acids resulted in the corresponding spiro[indene-2,2′-pyrrolizines] and [indene-2,6’-pyrrolo[1,2-c]thiazoles].
Comparison of Solid-Water Partitions of Radiocesium in River Waters in Fukushima and Chernobyl Areas
Authors: Takahashi Yoshio , Fan Qiaohui , Suga Hiroki , Tanaka Kazuya , Sakaguchi Aya , Takeichi Yasuo , Ono Kanta , Mase Kazuhiko , Kato Kenji , Kanivets Vladimir V. 
Published: September 2017

AbstractAdsorption of radiocesium (RCs) on particulate matters in aquatic environment is important to understand its mobility and bioavailability. We here focused on factors controlling partition of RCs on particulate matters and sediments in Kuchibuto (Fukushima) and Pripyat (Chernobyl) Rivers, though RCs level in water was much smaller than WHO guideline. Moreover, Cs speciation and organic matter-clay mineral interaction were studied: (i) extended X-ray absorption fine structure showed that the contribution of outer-sphere complex of Cs on particulate matters is larger in Chernobyl than in Fukushima and (ii) scanning transmission X-ray microscope revealed larger association of humic substances and clay minerals in Chernobyl partly due to high [Ca2+] in the Pripyat River. Consequently, RCs is more soluble in the Pripyat River due to weaker interaction of RCs with clay minerals caused by the inhibition effect of the adsorbed humic substances. In contrast, particulate matters and sediments in the Kuchibuto River display high adsorption affinity with lesser inhibition effect of adsorbed humic substances. This difference is possibly governed by the geology and soil type of provenances surrounding both catchments (Fukushima: weathered granite; Chernobyl: peat wetland and carbonate platform) which leads to high concentrations of organic matter and Ca2+ in the Pripyat River.
Rapid, cool sintering of wet processed yttria-stabilized zirconia ceramic electrolyte thin films
Authors: Park Jun-Sik , Kim Dug-Joong , Chung Wan-Ho , Lim Yonghyun , Kim Hak-Sung , Kim Young-Beom 
Published: September 2017

AbstractHere we report a photonic annealing process for yttria-stabilized zirconia films, which are one of the most well-known solid-state electrolytes for solid oxide fuel cells (SOFCs). Precursor films were coated using a wet-chemical method with a simple metal-organic precursor solution and directly annealed at standard pressure and temperature by two cycles of xenon flash lamp irradiation. The residual organics were almost completely decomposed in the first pre-annealing step, and the fluorite crystalline phases and good ionic conductivity were developed during the second annealing step. These films showed properties comparable to those of thermally annealed films. This process is much faster than conventional annealing processes (e.g. halogen furnaces); a few seconds compared to tens of hours, respectively. The significance of this work includes the treatment of solid-state electrolyte oxides for SOFCs and the demonstration of the feasibility of other oxide components for solid-state energy devices.
Hedgehog-Interacting Protein (HIP) Regulates Apoptosis Evasion and Angiogenic Function of Late Endothelial Progenitor Cells
Authors: Lee Bom Nae Rin , Son Yeon Sung , Lee Dabin , Choi Young-Jin , Kwon Sang-Mo , Chang Hyun-Kyung , Kim Pyung-Hwan , Cho Je-Yoel 
Published: September 2017

AbstractLate endothelial progenitor cells (LEPCs) are derived from mononuclear cells (MNCs) and are thought to directly incorporate into blood vessels and differentiate into mature endothelial cells (ECs). Using transcriptome and proteome analysis, we identified distinctive LEPC profiles and found that Hedgehog-interacting protein (HIP) is strongly expressed in LEPCs. Inhibition of HIP by lentiviral knockdown activated canonical hedgehog signaling in LEPCs, while it activated non-canonical hedgehog signaling in ECs. In LEPCs, HIP knockdown induced much enhanced tube formation and resistance to apoptosis under oxidative stress conditions via canonical hedgehog signaling. Although HIP is strongly expressed in proliferating LEPCs, HIP expression is down-regulated during angiogenesis and under oxidative stress condition. Moreover, when LEPCs are treated with angiogenic triggers such as VEGF and FGF2, HIP expression is reduced. Our findings suggest that HIP blocks LEPC angiogenesis and regulate survival when there is no angiogenic stimulation. HIP inhibition in LEPCs enhanced tube formation and reduced apoptosis, resulting in improved angiogenesis.
Normobaric hyperoxia does not improve derangements in diffusion tensor imaging found distant from visible contusions following acute traumatic brain injury
Authors: Veenith Tonny V. , Carter Eleanor L. , Grossac Julia , Newcombe Virginia F. J. , Outtrim Joanne G. , Nallapareddy Sri , Lupson Victoria , Correia Marta M. , Mada Marius M. , Williams Guy B. , Menon David K. , Coles Jonathan P. 
Published: September 2017

AbstractWe have previously shown that normobaric hyperoxia may benefit peri-lesional brain and white matter following traumatic brain injury (TBI). This study examined the impact of brief exposure to hyperoxia using diffusion tensor imaging (DTI) to identify axonal injury distant from contusions. Fourteen patients with acute moderate/severe TBI underwent baseline DTI and following one hour of 80% oxygen. Thirty-two controls underwent DTI, with 6 undergoing imaging following graded exposure to oxygen. Visible lesions were excluded and data compared with controls. We used the 99% prediction interval (PI) for zero change from historical control reproducibility measurements to demonstrate significant change following hyperoxia. Following hyperoxia DTI was unchanged in controls. In patients following hyperoxia, mean diffusivity (MD) was unchanged despite baseline values lower than controls (p < 0.05), and fractional anisotropy (FA) was lower within the left uncinate fasciculus, right caudate and occipital regions (p < 0.05). 16% of white and 14% of mixed cortical and grey matter patient regions showed FA decreases greater than the 99% PI for zero change. The mechanistic basis for some findings are unclear, but suggest that a short period of normobaric hyperoxia is not beneficial in this context. Confirmation following a longer period of hyperoxia is required.
Synthesis of prenylated flavonols and their potents as estrogen receptor modulator
Authors: Tao Zhenru , Liu Juan , Jiang Yueming , Gong Liang , Yang Bao 
Published: September 2017

AbstractPrenylated flavonols are known as phytoestrogen and have good bioactivties. However, their abundances in nature are pretty low. It is required to find an efficient synthesis technique. Icariin is a prenylated flavonol glycoside with low cost. It can be used to synthesize different prenylated flavonols. A combination of cellulase and trifluoacetic acid hydrolysis could effectively remove rhamnose and glucose from icariin. Icaritin, anhydroicaritin and wushanicaritin were the leading prenylated flavonol products. Their affinities to estrogen receptors α and β were predicted by docking study. The weak affinity of wushanicaritin indicated that prenyl hydroxylation impaired its affinity to estrogen receptor β. The prenyl cyclization led to a loss of affinity to both receptors. The interactions between icaritin and ligand binding cavity of estrogen receptor β were simulated. π-π stacking and hydrophobic forces were predicted to be the dominant interactions positioning icaritin, which induced the helix (H12) forming an activated conformation.
Declining soil Crustacea in a World Heritage Site caused by land nemertean
Authors: Shinobe Shotaro , Uchida Shota , Mori Hideaki , Okochi Isamu , Chiba Satoshi 
Published: September 2017

AbstractInvasive non-native species are of great concern throughout the world. Potential severity of the impacts of non-native species is assessed for effective conservation managements. However, such risk assessment is often difficult, and underestimating possible harm can cause substantial issues. Here, we document catastrophic decline of a soil ecosystem in the Ogasawara Islands, a UNESCO World Heritage site, due to predation by non-native land nemertineGeonemertes pelaensisof which harm has been previously unnoticed. This nemertine is widely distributed in tropical regions, and no study has shown that it feeds on arthropods. However, we experimentally confirmed thatG. pelaensispredates various arthropod groups. Soil fauna of Ogasawara was originally dominated by isopods and amphipods, but our surveys in the southern parts of Hahajima Island showed that these became extremely scarce in the areas invaded byG. pelaensis. Carnivorous arthropods decreased by indirect effects of its predation. Radical decline of soil arthropods since the 1980s on Chichijima Island was also caused byG. pelaensisand was first recorded in 1981. Thus, the soil ecosystem was already seriously damaged in Ogasawara by the nemertine. The present findings raise an issue and limitation in recognizing threats of non-native species.