bluuebunny/crossref_metadata_2025_split huggingface dataset:
Probing the Fluxional Bonding Nature of Rapid Cope rearrangements in Bullvalene C10H10 and Its Analogs C8H8, C9H10, and C8BH9
Authors: Ma Yuan-Yuan , Yan Miao , Li Hai-Ru , Wu Yan-Bo , Tian Xin-Xin , Lu Hai-Gang , Li Si-Dian 
Published: November 2019

AbstractBullvalene C10H10 and its analogs semibullvalene C8H8, barbaralane C9H10, and 9-Borabarbaralane C8BH9 are prototypical fluxional molecules with rapid Cope rearrangements at finite temperatures. Detailed bonding analyses performed in this work reveal the existence of two fluxional π-bonds (2 2c-2e π → 2 3c-2e π → 2 2c-2e π) and one fluxional σ-bond (1 2c-2e σ → 1 4c-2e σ → 1 2c-2e σ) in their ground states and transition states, unveiling the universal π + σ double fluxional bonding nature of these fluctuating cage-like species. The highest occupied natural bond orbitals (HONBOs) turn out to be typical fluxional bonds dominating the dynamics of the systems. The 13C-NMR and 1H-NMR shielding tensors and chemical shifts of the model compound C8BH9 are computationally predicted to facilitate future experiments.
Recruitment of a critically endangered sawfish into a riverine nursery depends on natural flow regimes
Authors: Lear Karissa O. , Gleiss Adrian C. , Whitty Jeff M. , Fazeldean Travis , Albert J. R. , Green Nathan , Ebner Brendan C. , Thorburn Dean C. , Beatty Stephen J. , Morgan David L. 
Published: November 2019

AbstractThe freshwater sawfish (Pristis pristis) was recently listed as the most Evolutionarily Distinct and Globally Endangered (EDGE) animal. The Fitzroy River in the remote Kimberley region of north-western Australia represents a significant stronghold for the species, which uses the freshwater reaches of the river as a nursery. There is also mounting pressure to develop the water resources of the region for agriculture that may substantially affect life history dynamics of sawfish in this system. However, the relationship between hydrology and population dynamics of freshwater sawfish was unknown. We used standardized catch data collected over 17 years to determine how wet season volume influences recruitment of freshwater sawfish into their riverine nursery. Negligible recruitment occurred in years with few days of high flood levels (above 98th percentile of cease-to-flow stage height), and relatively high recruitment occurred in years with 14 or more days of high flood levels. This relationship is indicative of a distinct boom-or-bust cycle, whereby freshwater sawfish rely almost entirely on the few years with large wet season floods, and the brief periods of highest water levels within these years, to replenish juvenile populations in the Fitzroy River nursery. This has direct implications for sustainable water resource management for the Fitzroy River basin in order to preserve one of the last known intact nursery habitats for this globally threatened species.
The podocin V260E mutation predicts steroid resistant nephrotic syndrome in black South African children with focal segmental glomerulosclerosis
Authors: Govender Melanie A. , Fabian June , Gottlich Errol , Levy Cecil , Moonsamy Glenda , Maher Heather , Winkler Cheryl A. , Ramsay Michèle 
Published: November 2019

AbstractIn black African children with focal segmental glomerulosclerosis (FSGS) there are high rates of steroid resistance. The aim was to determine genetic associations with apolipoprotein L1 (APOL1) renal risk variants and podocin (NPHS2) variants in 30 unrelated black South African children with FSGS. Three APOL1 variants were genotyped and the exons of the NPHS2 gene sequenced in the cases and controls. APOL1 risk alleles show a modest association with steroid sensitive nephrotic syndrome (SSNS) and steroid resistant nephrotic syndrome (SRNS). The NPHS2 V260E variant was present in SRNS cases (V/V = 5; V/E = 4; E/E = 11), and was absent in SSNS cases. Haplotype analysis suggests a single mutation origin for V260E and it was associated with a decline in kidney function over a 60-month period (p = 0.026). The V260E variant is a good predictor of autosomal recessive SRNS in black South African children and could provide useful information in a clinical setting.
Delta oscillations phase limit neural activity during sevoflurane anesthesia
Authors: Chamadia Shubham , Pedemonte Juan C. , Hahm Eunice Y. , Mekonnen Jennifer , Ibala Reine , Gitlin Jacob , Ethridge Breanna R. , Qu Jason , Vazquez Rafael , Rhee James , Liao Erika T. , Brown Emery N. , Akeju Oluwaseun 
Published: November 2019

AbstractUnderstanding anesthetic mechanisms with the goal of producing anesthetic states with limited systemic side effects is a major objective of neuroscience research in anesthesiology. Coherent frontal alpha oscillations have been postulated as a mechanism of sevoflurane general anesthesia. This postulate remains unproven. Therefore, we performed a single-site, randomized, cross-over, high-density electroencephalogram study of sevoflurane and sevoflurane-plus-ketamine general anesthesia in 12 healthy subjects. Data were analyzed with multitaper spectral, global coherence, cross-frequency coupling, and phase-dependent methods. Our results suggest that coherent alpha oscillations are not fundamental for maintaining sevoflurane general anesthesia. Taken together, our results suggest that subanesthetic and general anesthetic sevoflurane brain states emerge from impaired information processing instantiated by a delta-higher frequency phase-amplitude coupling syntax. These results provide fundamental new insights into the neural circuit mechanisms of sevoflurane anesthesia and suggest that anesthetic states may be produced by extracranial perturbations that cause delta-higher frequency phase-amplitude interactions.
Synthesis, characterization, and antitumor properties of Au(i)–thiourea complexes
Authors: Yu Bingqiong , Liu Yanhong , Peng Xian , Hua Siyu , Zhou Gangcheng , Yan Kun , Liu Yi 
Published: November 2019

AbstractThe anticancer property of cisplatin has stimulated the development of metal complexes as antitumor agents. Among these complexes, metal thiourea complexes have attracted sufficient attention, and they possess the potential possibility to become new antitumor metallodrugs. Herein, four Au(i) complexes derived from N,N-disubstituted cyclic thiourea ligands were synthesized and characterized. The crystal structure analysis indicated that the complex Au(i)(3c)2OTf was a mononuclear crystal structure with Au(i) coordinated by two sulfur atoms. These Au(i) complexes exhibited excellent toxicities against several tumor cell lines, especially complex Au(i)(3c)2OTf (IC50 = 8.06 μM against HeLa). It was found that Au(i)(3c)2OTf triggered a burst of ROS, disrupted the mitochondrial membrane potential (MMP), subsequently released Cyt-c, and then triggered the activation of caspase 9, caspase 7 and caspase 3. Mechanism experiments manifested that Au(i)(3c)2OTf induced the down-regulation of Bcl-2 and up-regulation of Bax, which further indicated that Au(i)(3c)2OTf triggered mitochondria-mediated apoptosis. In addition, the ROS scavenger-NAC completely blocked the apoptosis and inhibited the reduction of MMP, showing that Au(i)(3c)2OTf induced a ROS-dependent apoptosis pathway. These results indicate that Au(i)(3c)2OTf is worthy of in-depth research as an antitumor agent and may throw light on a better understanding of the effect of thiourea derivatives on antitumor mechanisms.
Poly-amino acids coated gold nanorod and doxorubicin for synergistic photodynamic therapy and chemotherapy in ovarian cancer cells
Authors: Liu JinYing , Ma Wei , Kou Wei , Shang Lina , Huang Rui , Zhao Jin 
Published: November 2019

Abstract
In this work, we have successfully designed and formulated a doxorubicin-loaded polypeptide-based multilayer assembled gold nanorod (DH-GNR). We have hypothesized that near-infrared (NIR) laser irradiation of DH-GNR will combine the benefits of chemotherapy and photothermal therapy. The GNR was surface functionalized with poly-glutamic acid (PGA) and poly-l-Lysine (PLL) with a final layer of hyaluronic acid (HA) that could also serve as a targeting ligand toward the overexpressed CD44 receptors in ovarian cancer cells. The zigzag ζ potential of nanoparticle is a proof of successful assembly of alternative polymers on the GNR surface. NIR irradiation exhibited a burst release of drug in pH 7.4 and pH 5.0 buffer conditions. The combination of doxorubicin (DOX)-based chemotherapy and GNR-based photothermal therapy exhibited a synergistic effect in killing the SKOV3 cancer cells. DH-GNR(+NIR) induced a 82.5% apoptosis (combined early and late apoptosis) compared with only 35.2 and 38.5% for DOX or DH-GNR(−NIR) treated cell group. Results clearly suggest that the excessive reactive oxygen species (ROS) generation in DH-GNR (+NIR) might be responsible for the cell apoptosis and cell death. The promising anticancer effect of DH-GNR will be of great potential in the treatment of ovarian cancers and worth further development for treating other malignant tumors.
Combined in silico and 19F NMR analysis of 5-fluorouracil metabolism in yeast at low ATP conditions
Authors: Pawłowski Piotr H. , Szczęsny Paweł , Rempoła Bożenna , Poznańska Anna , Poznański Jarosław 
Published: November 2019

Abstract
The cytotoxic effect of 5-fluorouracil (5-FU) on yeast cells is thought to be mainly via a misincorporation of fluoropyrimidines into both RNA and DNA, not only DNA damage via inhibition of thymidylate synthase (TYMS) by fluorodeoxyuridine monophosphate (FdUMP). However, some studies on Saccharomyces cerevisiae show a drastic decrease in ATP concentration under oxidative stress, together with a decrease in concentration of other tri- and diphosphates. This raises a question if hydrolysis of 5-fluoro-2-deoxyuridine diphosphate (FdUDP) under oxidative stress could not lead to the presence of FdUMP and the activation of so-called ‘thymine-less death’ route. We attempted to answer this question with in silico modeling of 5-FU metabolic pathways, based on new experimental results, where the stages of intracellular metabolism of 5-FU in Saccharomyces cerevisiae were tracked by a combination of 19F and 31P NMR spectroscopic study. We have identified 5-FU, its nucleosides and nucleotides, and subsequent di- and/or triphosphates. Additionally, another wide 19F signal, assigned to fluorinated unstructured short RNA, has been also identified in the spectra. The concentration of individual metabolites was found to vary substantially within hours, however, the initial steady-state was preserved only for an hour, until the ATP concentration dropped by a half, which was monitored independently via 31P NMR spectra. After that, the catabolic process leading from triphosphates through monophosphates and nucleosides back to 5-FU was observed. These results imply careful design and interpretation of studies in 5-FU metabolism in yeast.
Late encounter events as source of disks and spiral structures
Authors: Kuffmeier M. , Goicovic F. G. , Dullemond C. P. 
Published: November 2019

Context. Observations of arc-like structures and luminosity bursts of stars >1 Myr in age indicate that at least some stars undergo late infall events.
Aims. We investigate scenarios of replenishing the mass reservoir around a star via capturing and infalling events of cloudlets.
Methods. We carried out a total of 24 three-dimensional hydrodynamical simulations of cloudlet encounters with a Herbig star of mass 2.5 M⊙ using the moving-mesh code AREPO. To account for the two possibilities of a star or a cloudlet traveling through the interstellar medium (ISM), we put either the star or the cloudlet at rest with respect to the background gas.
Results. For absent cooling in the adiabatic runs, almost none of the cloudlet gas is captured as a result of high thermal pressure. However, second-generation disks easily form when accounting for cooling of the gas. The disk radii range from several 100 to ~1000 au and associated arc-like structures up to 104 au in length form around the star for runs with and without stellar irradiation. Consistent with angular momentum conservation, the arcs and disks are larger for larger impact parameters. Accounting for turbulence in the cloudlet only mildly changes the model outcome. In the case of the star being at rest with the background gas, the disk formation and mass replenishment process is more pronounced and the associated arc-shaped streamers are longer lived.
Conclusions. The results of our models confirm that late encounter events lead to the formation of transitional disks associated with arc-shaped structures such as observed for AB Aurigae or HD 100546. In addition, we find that second-generation disks and their associated filamentary arms are longer lived (>105 yr) in infall events, when the star is at rest with the background gas.
Temperature profiles of young disk-like structures
Authors: van ’t Hoff Merel L. R. , van Dishoeck Ewine F. , Jørgensen Jes K. , Calcutt Hannah 
Published: November 2019

Context. Temperature is a crucial parameter in circumstellar disk evolution and planet formation because it governs the resistance of the gas to gravitational instability and sets the chemical composition of the planet-forming material.
Aims. We set out to determine the gas temperature of the young disk-like structure around the Class 0 protostar IRAS 16293–2422A.
Methods. We used Atacama Large Millimeter/submillimeter Array (ALMA) observations of multiple H2CS J = 7 − 6 and J = 10 − 9 lines from the Protostellar Interferometric Line Survey (PILS) to create a temperature map for the inner ~200 AU of the disk-like structure. This molecule is a particularly useful temperature probe because transitions between energy levels with different Ka quantum numbers operate only through collisions.
Results. Based on the H2CS line ratios, the temperature is between ~100–175 K in the inner ~150 AU, and drops to ~75 K at ~200 AU. At the current resolution (0.5′′~70 AU), no jump is seen in the temperature at the disk–envelope interface.
Conclusions. The temperature structure derived from H2CS is consistent with envelope temperature profiles that constrain the temperature from 1000 AU scales down to ~100 AU, but does not follow the temperature rise seen in these profiles at smaller radii. Higher angular resolution observations of optically thin temperature tracers are needed to establish whether cooling by gas-phase water, the presence of a putative disk, or the dust optical depth influences the gas temperature at ≲100 AU scales. The temperature at 100 AU is higher in IRAS 16293A than in the embedded Class 0/I disk L1527, consistent with the higher luminosity of the former.
Correlation femtoscopy at NICA energies
Authors: Mikhaylov Konstantin , Batyuk Pavel , Kodolova Olga , Malinina Lyudmila , Nigmatkulov Grigory , Romanenko Gleb 
Published: November 2019

The space-time characteristics of particle production are measured by the correlation femtoscopy with use of quantum statistics (QS) and final state interactions (FSI) effects. Femtoscopy at lower energy was a key of importance at AGS, SPS and in the Beam Energy Scan (BES) physics program at RHIC.
Using femtoscopy observables we investigate possibilities to observe a difference from the first-order phase transition expected, according to some theoretical predictions, at low energies and the cross over one, to be occurred at high energies. The hybrid model vHLLE+UrQM is used as a baseline for this study. The possibilities to use kaon femtoscopy complementary to the usually used pion one are discussed.
LHCb results on rare leptonic decays of B-mesons
Authors: Kurbatov Evgenii 
Published: November 2019

A search for the rare leptonic decays was performed, using the proton-proton collision data collected with the LHCb experiment at center-ofmass energies of 8TeV and 13TeV. The following analysis are reviewed in this work:
• Measurements of the B0s → µ+µ− branching fraction and effective lifetime and search for B0 → µ+µ− decays
• Search for the decays B0s → τ+τ− and B0 → τ+τ−
• Search for the lepton-flavour violating decays B0(s) → e±µ∓
• Search for the lepton-flavour-violating decays B0s → τ±µ∓ and B0 → τ±µ∓
• Search for the rare decay B+ → µ+µ−µ+νµ
All results are consistent with the Standard Model. Nearly all results presented are either unique or the most accurate for the time.
Advanced instructions for imparting knowledge: Getting scientists heard amidst the noise of fake news
Authors: Plüss Matthias 
Published: November 2019

A compacted re-print of an article by science writer Matthias Plüss, Swiss Science Magazine ‘Horizons’ of 05/06/2018 – DOI: https://doi.org/10.1051/epn/2019507
It’s getting more and more difficult for experts to get their arguments across to a broad public. We investigate why, and offer six suggestions for improving things.
A portrait of wellbore leakage in northeastern British Columbia, Canada
Authors: Wisen Joshua , Chesnaux Romain , Werring John , Wendling Gilles , Baudron Paul , Barbecot Florent 
Published: November 2019

Significance
The possibility of leakage from oil and gas wells has raised environmental concerns. There are 2 major environmental consequences of wellbore leakage: 1) the risk of groundwater contamination from hydrocarbons and brines and 2) the risk of greenhouse gas (GHG) emissions. In this study, oil and gas wellbore leakage data from British Columbia (BC) were analyzed in order to quantify the occurrence and pathways of leakage as well as the contribution to GHG emissions. The key results summarize as follows. 1) In total, 2,329 wells in BC (of 21,525 that have been tested for leakage) have had reported leakage during the lifetime of the well. 2) In total, GHG emissions are estimated to reach about 75,000 metric t/y. The study also underlines that the values of leaky wells are likely underreported.
Bone-inspired microarchitectures achieve enhanced fatigue life
Authors: Torres Ashley M. , Trikanad Adwait A. , Aubin Cameron A. , Lambers Floor M. , Luna Marysol , Rimnac Clare M. , Zavattieri Pablo , Hernandez Christopher J. 
Published: November 2019

Significance
Microarchitectured materials, such as foams and lattice structures, can achieve high stiffness and strength while remaining extremely lightweight. Applying high-porosity microarchitectured materials to durable devices, such as vehicles, however, will require the materials to also resist failure during cyclic loading. Here, we identify an aspect of microstructure in cancellous bone that greatly influences failure under cyclic loading and show that the effect is generalizable to synthetic microarchitectured materials. Our findings demonstrate that a common design strategy to improve stiffness and strength of microarchitectured materials comes at the cost of impaired service life. Our findings are useful for the design and application of microarchitectured materials and additionally provide insight into human health in situations of osteoporosis.
Spin foam models and the Duflo map
Authors: Finocchiaro Marco , Oriti Daniele 
Published: November 2019

Abstract
We give a general definition of spin foam models, and then of models of 4d quantum gravity based on constraining BF theory. We highlight the construction and quantization ambiguities entering model building, among which the choice of quantization map applied to the B variables carrying metric information after imposing simplicity constraints, and the different strategies for imposing the latter constraints. We then construct a new spin foam model for 4d quantum gravity, using the flux representation of states and amplitudes, based on the Duflo quantization map and the associated non-commutative Fourier transform for Lie groups. The advantages of the new model are the geometrically transparent way in which constraints are imposed, and the underlying mathematical properties of the Duflo map itself. Finally, the presence of a closed analytical formula for the model’s amplitudes is another valuable asset for future applications.
Hard X-ray Imager (HXI) onboard the ASO-S mission
Authors: Zhang Zhe , Chen Deng-Yi , Wu Jian , Chang Jin , Hu Yi-Ming , Su Yang , Zhang Yan , Wang Jian-Ping , Liang Yao-Ming , Ma Tao , Guo Jian-Hua , Cai Ming-Sheng , Zhang Yong-Qiang , Huang Yong-Yi , Peng Xiao-Yan , Tang Zong-Bin , Zhao Xuan , Zhou Hong-He , Wang Lian-Guo , Song Jing-Xing , Ma Miao , Xu Guang-Zhou , Yang Jian-Feng , Lu Di , He Ying-Hong , Tao Jin-You , Ma Xiao-Long , Lv Bao-Gang , Bai Yan-Ping , Cao Cai-Xia , Huang Yu , Gan Wei-Qun 
Published: November 2019

Abstract
Hard X-ray Imager (HXI) is one of the three scientific instruments onboard the Advanced Spacebased Solar Observatory (ASO-S) mission, which is proposed for the 25th solar maximum by the Chinese solar community. HXI is designed to investigate the non-thermal high-energy electrons accelerated in solar flares by providing images of solar flaring regions in the energy range from 30 keV to 200 keV. The imaging principle of HXI is based on spatially modulated Fourier synthesis and utilizes about 91 sets of bi-grid sub-collimators and corresponding LaBr3 detectors to obtain Fourier components with a spatial resolution of about 3 arcsec and a time resolution better than 0.5 s. An engineering prototype has been developed and tested to verify the feasibility of design. In this paper, we present background, instrument design and the development and test status of the prototype.
Lyα science from the LST aboard the ASO-S mission
Authors: Vourlidas Angelos 
Published: November 2019

Abstract
We review the status of solar Lyα science in anticipation of the upcoming Advanced Space-based Solar Observatory (ASO-S) mission, planned for a late 2021 (or 2022) launch. The mission carries a pair of the Lyα Solar Telescopes (LST) capable of high resolution disk and off-limb imaging, which will provide the first synoptic Lyα imaging observations of the solar atmosphere. We discuss the history of Lyα imaging and latest results, and outline the open questions that ASO-S could address. ASO-S will launch at an optimal time for Lyα science. Several other Lyα telescopes will be in operation. We identify the synergies between ASO-S and other missions as well as serendipitous non-solar science opportunities. We conclude that ASO-S has the potential for breakthrough observations and discoveries in the chromosphere-corona interface where the Lyα emission is the major player.
Advances in flexible and wearable pH sensors for wound healing monitoring
Authors: Qin Mei , Guo Hao , Dai Zhang , Yan Xu , Ning Xin 
Published: November 2019

Abstract
Wound healing has been recognized as a complex and dynamic regeneration process and attracted increasing interests on its management. For effective wound healing management, a continuous monitoring on the wound healing based on sensors is essential. Since pH has been found to play an important role on wound healing process, a variety of pH sensors systems for wound healing monitoring have been greatly developed in recent years. Among these pH sensors, flexible and wearable pH sensors which can be incorporated with wound dressing have gained much attention. In this review, the recent advances in the development of flexible and wearable pH sensors for wound healing monitoring have been comprehensive summarized from the range of optical and electrochemical bases.