bluuebunny/crossref_metadata_2025 huggingface dataset:
Nucleosynthesis in Population III Supernovae
Authors: Nomoto K. , Maeda K. , Umeda H. , Tominaga N.
Published: March 2016

Stars more massive than ~ 20–25 M⊙ form a black hole at the end of their evolution. Stars with non-rotating black holes are likely to collapse ”quietly” ejecting a small amount of heavy elements (Faint supernovae). In contrast, stars with rotating black holes are likely to give rise to very energetic supernovae (Hypernovae). Nucleosynthesis in Hypernovae is characterized by larger abundance ratios (Zn,Co,V,Ti)/Fe and smaller (Mn,Cr)/Fe than normal supernovae, which can explain the observed trend of these ratios in extremely metal-poor stars. Nucleosynthesis in Faint supernovae is characterized by a large amount of fall-back. We show that the abundance pattern of the recently discovered most Fe-poor star, HE0107-5240, and other extremely metal-poor carbon-rich stars are in good accord with those of black-hole-forming supernovae, but not pair-instability supernovae. This suggests that black-hole-forming supernovae made important contributions to the early Galactic (and cosmic) chemical evolution as the First (Pop III) Supernovae.
New Radiative Atomic Data
Authors: Nahar Sultana N.
Published: March 2016

Large amount of new radiative atomic data for I) energy levels, II) oscillator strengths (f), line strengths (S), radiative transition probabilities (A), III) photoioniztion cross sections (σPI) – total and level-specific, and IV) unified total and level-specific electron-ion recombination rate coefficients, αR, including radiative and dielectronic recombination (RR and DR) are reported for various astrophysical applications. Most of the data are with fine structure. These data are not yet available from any databases. Photoionization and recombination data are self-consistent, using the same wave-function for both processes.
NEAR at Mathilde and Eros: An Update
Authors: Cheng Andrew
Published: March 2016

At the slowly rotating C-asteroid Mathilde, the Near Earth Asteroid Rendezvous (NEAR) mission imaged only one face of the body but still constrained the density to only 1.3 g/cm3, indicating high porosity. This porosity and the approximate saturation of the surface with giant craters led to suggestions that Mathilde must be a rubble pile. At S-type Eros, NEAR measured elemental abundances and spatially resolved reflectance spectra that appear most consistent with an ordinary chondrite composition, although the Eros composition could not be identified with any known meteorite type. Imaging and altimetry data were interpreted as showing Eros to be a globally consolidated, albeit heavily fractured, collisional shard. A spectacular feature, ponding of regolith on Eros, was discovered. Continuing analyses of NEAR data suggest that Mathilde is not strengthless, and that if it is a rubble pile, large coherent components are present. Both composition and internal structure of Eros pose unresolved issues. Although almost uniform internally, Eros cannot be perfectly so. The density of 2.67 g/cm3 is significantly less than that of ordinary chondrites and suggests significant porosity, but this may not be explained by macroscopic fracturing if these spaces can be filled with particulates.
The ISHTAR Mission: Probing the Internal Structure of NEOs
Authors: Barucci M. Antonietta , D’Arrigo Paolo , Ball P. , Doressoundiram Alain , Dotto Elisabetta , Kofman W. , Orosei Roberto , Patzold Martin , Perozzi Ettore
Published: March 2016

ISHTAR (Internal Structure High-resolution Tomography by Asteroid Rendezvous) is a mission developed through ESA General Studies programme. The study, led by Astrium in cooperation with several scientific institutes throughout Europe, has produced a spacecraft design capable of performing multiple asteroid rendezvous and to characterize them with a focussed set of instruments. The ISHTAR concept is centred around a Radar Tomography paylod able to probe the internal structure of a small asteroid to depths of few hundred meters, combined with a small camera for investigation of the surface properties and a radio science experiment for gravity field measurement. This combination will allow the first detailed characterization of a NEO and will give valuable insights into the origin and evolution processes that govern the NEO population. In particular, ISHTAR will be able to visit at least 2 NEOs belonging to two different spectral classes, thereby allowing us to probe the diversity of the NEO population.
The Deep Impact Project
Authors: A’Hearn Michael F. ,   The Deep Impact Project Team
Published: March 2016

The Deep Impact mission aims at understanding the third dimension of a cometary nucleus, the physical and chemical properties as a function of depth below the surface. General wisdom holds that comets, because they are small and spend most of their lives far from the sun, hold primordial ices in their interiors. However, it is universally agreed that the surface layers have evolved, whether from cosmic rays while residing in the Oort cloud or from solar heating during previous perihelion passages. Clearly, in order to interpret surface observations and outgassing, we must understand how the surface layers differ from the interior. Deep Impact is the first mission to carry out a macroscopic experiment on a planetary body since the Apollo program dropped a lunar module on the moon and measured the seismic response.
Ground-Based Optical Observations of Asteroids
Authors: Cellino Alberto
Published: March 2016

Many physical parameters of asteroids can be inferred from remote measurements at optical wavelengths. These observations constitute the bulk of the information we have about these objects, and nicely complement the detailed physical studies which are made possible by in situ explorations of a few selected targets. The discovery of many binary systems for which mass determinations become possible, the identification of hydration features in asteroid spectra, including unexpectedly many M-types, the detection of space-weathering phenomena affecting S-type near-Earth objects, as well as improved estimates of sizes, albedos, and spin properties for many objects are among the major results obtained in recent years by means of remote-sensing techniques. These data can be used to infer important properties of the internal structures of the asteroids.
Gamma-ray Spectroscopy
Authors: Knödlseder Jürgen
Published: March 2016

Gamma-ray spectroscopy has made important progress with the observations of the OSSE and COMPTEL telescopes aboard CGRO, and has entered the domain of high-resolution spectroscopy with the launch of the SPI telescope aboard the INTEGRAL satellite. Recent science highlights in this field are presented, and an outlook is given to future promising projects.
Surface Gravities and Masses in Substellar Objects
Authors: Mohanty Subhanjoy , Basri Gibor , Jayawardhana Ray
Published: March 2016

Using high-resolution optical spectra, we determine effective temperatures and gravities for a sample of very low-mass stellar and substellar PMS cluster objects. Masses and radii are then derived using known cluster distance and photometry; two of our targets seem to have planetary masses. Our results are independent of theoretical evolutionary tracks. While our results agree with the track predictions for hotter, higher mass objects, discrepancies appear for the coolest, lowest mass ones. This may be due to track uncertainties related to formation effects, and/or internal conditions, in these very young, ultra-low-mass objects.
The Distribution and Nature of Titan’s Aerosols: A New Look
Authors: Lemmon Mark T. , Smith Peter H. , Lorenz Ralph D.
Published: March 2016

Titan passed through southern summer solstice in late 2002, allowing an unprecedented view of summer seasonal effects. A set of images was acquired with the Hubble Space Telescope spanning the 0.25-2 μmspectral range. Among the effects seen were a rapidly changing hemispheric asymmetry and a polar hood that is visible at short wavelengths. The north-south asymmetry has reversed, returning Titans dominant visual feature to something like its Voyager-era state. The polar hood is spectrally different from the north-south asymmetry and is due to a mode of small particles. The amount of absorbing material in the polar hood cannot be uniquely constrained, but a lower limit can be derived by assuming that the absorber is the same as that found in the main haze (i.e., it is analogous to Titan tholin) and that the absorber is entirely above the main haze. The hood spectrum is consistent with about 4xl0_6g/cm2 of tholin-like material above the main haze south of 65 S. A larger amount of material mixed lower in the atmosphere cannot be ruled out. An upper limit to the particle radius of about 0.02 μmcan be determined by the lack of a bright polar hood in near-infrared methane band images. Considering time scales for removing material from the stratosphere leads to an estimate of summer polar mass production that is within a factor of five of published estimates of annual, global aerosol mass production. More detailed modeling of the observations is proceeding. The model includes the prediction of disk-resolved polarization based on particle characteristics. Comparisons to HST polarimetric images will provide new constraints on the properties of the northern, southern, and polar aerosols. Preliminary analysis of the polarimetry images shows the polarization is radial at all wavelengths (0.25-2 μm) and the magnitude of polarization peaks near 0.75 μm. The polarization is consistent with small particles, but is less than predicted by models of Pioneer 11 and Voyager 2 polarimetry.
The New Horizons Mission to Pluto-Charon and the Kuiper Belt
Authors: Tyler G. Leonard , Stern S. Alan , Weaver Harold A.
Published: March 2016

The New Horizons Mission to Pluto-Charon and the Kuiper Belt is under development for launch in 2006. The experiment complement of eight sensors addresses fundamental issues of density, composition, albedo, geology, and atmospheric state, chemistry, and escape.
Mapping Mars at Global to Human Scales
Authors: Archinal Brent A. , Kirk Randolph L. , Howington-Kraus Elpitha , Rosiek Mark R. , Soderblom Laurence A. , Lee Ella M.
Published: March 2016

We report on current Mars mapping projects in support of NASA planetary exploration. This includes a summary of the current state and accuracy of such mapping at global, regional, and local (human) scales. The availability of Mars Orbiter Laser Altimeter data has revolutionized such mapping. Aside from its use as a global topographic dataset, images can easily be correlated to it with absolute uncertainties of ≈100 m horizontally. We are using this to create a revised version of the global Mars digital image mosaic (MDIM) that will have absolute errors of ≈231 m (one pixel) and improved cosmetic characteristics. We are undertaking stereo-topographic mapping at regional to local scales, using Viking and Mars Orbiter Camera Narrow Angle (NA) images, with horizontal resolutions of 600 to 5 m, and expected vertical precision of 200 to 1 m. Derived topography and altimetric information can also be used to calibrate shape-from-shading (photoclinometry) topographic models at down to single-pixel resolution (i.e. 1.4 m for NA images). Products of these efforts have a multitude of purposes, from assisting in large-scale geologic mapping, to characterizing the geology/safety of proposed landing sites. Plans are underway to also use THEMIS, HRSC, and HiRISE camera data in future efforts.
Paradox of Flows on Mars
Authors: Ksanfomality L.V.
Published: March 2016

Using the high-resolution images acquired by cameras onboard the MARS GLOBAL SURVEYOR orbiter made it possible to reveal the previously unknown objects on the Martian surface, which changed dramatically a notion of Mars as a dry, hydrologically dead planet (Malin and Edgett, 2000). Examination of new images shows that the nature of some extended dark formations on the slopes of craters and uplands may be associated with contemporary abundant sources of liquid water arising on the slopes at small depths below the level of surrounding plains.
A Large Reflective Schmidt Telescope for Antarctica
Authors: Saunders Will , McGrath Andrew
Published: March 2016

We present a simple design for a 16 metre, wide-field, fixed-axis, all-reflective, low cost f/4 Schmidt telescope to take advantage of the unique advantages of Antarctica as an Optical/IR site.
FTS Opacity Measurements of the South Pole Submillimeter Sky
Authors: Chamberlin Richard A.
Published: March 2016

A sub-millimeter Fourier Transform Spectrometer (FTS) was used at the South Pole to acquire wide frequency span (300 GHz < v < 2 THz) measurements of the atmospheric opacity, T(V). Comparisons were made with other ongoing measurements to allow inference of typical wintertime observing statistics.
Space Telescope Findings Suggest Molten Planetary Surface
Authors: Wendel JoAnna
Published: March 2016

Researchers studying the super-Earth 55 Cancri e spotted some puzzling features that provide a new vision of the orb's surface.
The fine tuning of metabolism, autophagy and differentiation during in vitro myogenesis
Authors: Fortini P , Ferretti C , Iorio E , Cagnin M , Garribba L , Pietraforte D , Falchi M , Pascucci B , Baccarini S , Morani F , Phadngam S , De Luca G , Isidoro C , Dogliotti E
Published: March 2016

Although the mechanisms controlling skeletal muscle homeostasis have been identified, there is a lack of knowledge of the integrated dynamic processes occurring during myogenesis and their regulation. Here, metabolism, autophagy and differentiation were concomitantly analyzed in mouse muscle satellite cell (MSC)-derived myoblasts and their cross-talk addressed by drug and genetic manipulation. We show that increased mitochondrial biogenesis and activation of mammalian target of rapamycin complex 1 inactivation-independent basal autophagy characterize the conversion of myoblasts into myotubes. Notably, inhibition of autophagic flux halts cell fusion in the latest stages of differentiation and, conversely, when the fusion step of myocytes is impaired the biogenesis of autophagosomes is also impaired. By using myoblasts derived from p53 null mice, we show that in the absence of p53 glycolysis prevails and mitochondrial biogenesis is strongly impaired. P53 null myoblasts show defective terminal differentiation and attenuated basal autophagy when switched into differentiating culture conditions. In conclusion, we demonstrate that basal autophagy contributes to a correct execution of myogenesis and that physiological p53 activity is required for muscle homeostasis by regulating metabolism and by affecting autophagy and differentiation.
Local proliferation initiates macrophage accumulation in adipose tissue during obesity
Authors: Zheng C , Yang Q , Cao J , Xie N , Liu K , Shou P , Qian F , Wang Y , Shi Y
Published: March 2016

Obesity-associated chronic inflammation is characterized by an accumulation of adipose tissue macrophages (ATMs). It is generally believed that those macrophages are derived from peripheral blood monocytes. However, recent studies suggest that local proliferation of macrophages is responsible for ATM accumulation. In the present study, we revealed that both migration and proliferation contribute to ATM accumulation during obesity development. We show that there is a significant increase in ATMs at the early stage of obesity, which is largely due to an enhanced in situ macrophage proliferation. This result was obtained by employing fat-shielded irradiation and bone marrow reconstitution. Additionally, the production of CCL2, a pivotal chemoattractant of monocytes, was not found to be increased at this stage, corroborating with a critical role of proliferation. Nonetheless, as obesity proceeds, the role of monocyte migration into adipose tissue becomes more significant and those new immigrants further proliferate locally. These proliferating ATMs mainly reside in crown-like structures formed by macrophages surrounding dead adipocytes. We further showed that IL-4/STAT6 is a driving force for ATM proliferation. Therefore, we demonstrated that local proliferation of resident macrophages contributes to ATM accumulation during obesity development and has a key role in obesity-associated inflammation.
Nupr1/Chop signal axis is involved in mitochondrion-related endothelial cell apoptosis induced by methamphetamine
Authors: Cai D , Huang E , Luo B , Yang Y , Zhang F , Liu C , Lin Z , Xie W-B , Wang H
Published: March 2016

Methamphetamine (METH) abuse has been a serious global public health problem for decades. Previous studies have shown that METH causes detrimental effects on the nervous and cardiovascular systems. METH-induced cardiovascular toxicity has been, in part, attributed to its destructive effect on vascular endothelial cells. However, the underlying mechanism of METH-caused endothelium disruption has not been investigated systematically. In this study, we identified a novel pathway involved in endothelial cell apoptosis induced by METH. We demonstrated that exposure to METH caused mitochondrial apoptosis in human umbilical vein endothelial cells and rat cardiac microvascular endothelial cells in vitro as well as in rat cardiac endothelial cells in vivo. We found that METH mediated endothelial cell apoptosis through Nupr1–Chop/P53–PUMA/Beclin1 signaling pathway. Specifically, METH exposure increased the expression of Nupr1, Chop, P53 and PUMA. Elevated p53 expression raised up PUMA expression, which initiated mitochondrial apoptosis by downregulating antiapoptotic Bcl-2, followed by upregulation of proapoptotic Bax, resulting in translocation of cytochrome c (cyto c), an apoptogenic factor, from the mitochondria to cytoplasm and activation of caspase-dependent pathways. Interestingly, increased Beclin1, upregulated by Chop, formed a ternary complex with Bcl-2, thereby decreasing the dissociative Bcl-2. As a result, the ratio of dissociative Bcl-2 to Bax was also significantly decreased, which led to translocation of cyto c and initiated more drastic apoptosis. These findings were supported by data showing METH-induced apoptosis was significantly inhibited by silencing Nupr1, Chop or P53, or by PUMA or Beclin1 knockdown. Based on the present data, a novel mechanistic model of METH-induced endothelial cell toxicity is proposed. Collectively, these results highlight that the Nupr1–Chop/P53–PUMA/Beclin1 pathway is essential for mitochondrion-related METH-induced endothelial cell apoptosis and may be a potential therapeutic target for METH-caused cardiovascular toxicity. Future studies using knockout animal models are warranted to substantiate the present findings.
Dihydroartemisinin attenuates lipopolysaccharide-induced osteoclastogenesis and bone loss via the mitochondria-dependent apoptosis pathway
Authors: Dou C , Ding N , Xing J , Zhao C , Kang F , Hou T , Quan H , Chen Y , Dai Q , Luo F , Xu J , Dong S
Published: March 2016

Dihydroartemisinin (DHA) is a widely used antimalarial drug isolated from the plant Artemisia annua. Recent studies suggested that DHA has antitumor effects utilizing its reactive oxygen species (ROS) yielding mechanism. Here, we reported that DHA is inhibitory on lipopolysaccharide (LPS)-induced osteoclast (OC) differentiation, fusion and bone-resorption activity in vitro. Intracellular ROS detection revealed that DHA could remarkably increase ROS accumulation during LPS-induced osteoclastogenesis. Moreover, cell apoptosis was also increased by DHA treatment. We found that DHA-activated caspase-3 increased Bax/Bcl-2 ratio during LPS-induced osteoclastogenesis. Meanwhile, the translocation of apoptotic inducing factor (AIF) and the release of cytochrome c from the mitochondria into the cytosol were observed, indicating that ROS-mediated mitochondrial dysfunction is crucial in DHA-induced apoptosis during LPS-induced osteoclastogenesis. In vivo study showed that DHA treatment decreased OC number, prevents bone loss, rescues bone microarchitecture and restores bone strength in LPS-induced bone-loss mouse model. Together, our findings indicate that DHA is protective against LPS-induced bone loss through apoptosis induction of osteoclasts via ROS accumulation and the mitochondria-dependent apoptosis pathway. Therefore, DHA may be considered as a new therapeutic candidate for treating inflammatory bone loss.
Quaking promotes monocyte differentiation into pro-atherogenic macrophages by controlling pre-mRNA splicing and gene expression
Authors: de Bruin Ruben G. , Shiue Lily , Prins Jurriën , de Boer Hetty C. , Singh Anjana , Fagg W. Samuel , van Gils Janine M. , Duijs Jacques M. G. J. , Katzman Sol , Kraaijeveld Adriaan O. , Böhringer Stefan , Leung Wai Y. , Kielbasa Szymon M. , Donahue John P. , van der Zande Patrick H.J. , Sijbom Rick , van Alem Carla M. A. , Bot Ilze , van Kooten Cees , Jukema J. Wouter , Van Esch Hilde , Rabelink Ton J. , Kazan Hilal , Biessen Erik A. L. , Ares Manuel , van Zonneveld Anton Jan , van der Veer Eric P.
Published: March 2016

A hallmark of inflammatory diseases is the excessive recruitment and influx of monocytes to sites of tissue damage and their ensuing differentiation into macrophages. Numerous stimuli are known to induce transcriptional changes associated with macrophage phenotype, but posttranscriptional control of human macrophage differentiation is less well understood. Here we show that expression levels of the RNA-binding protein Quaking (QKI) are low in monocytes and early human atherosclerotic lesions, but are abundant in macrophages of advanced plaques. Depletion of QKI protein impairs monocyte adhesion, migration, differentiation into macrophages and foam cell formation in vitro and in vivo. RNA-seq and microarray analysis of human monocyte and macrophage transcriptomes, including those of a unique QKI haploinsufficient patient, reveal striking changes in QKI-dependent messenger RNA levels and splicing of RNA transcripts. The biological importance of these transcripts and requirement for QKI during differentiation illustrates a central role for QKI in posttranscriptionally guiding macrophage identity and function.
Revisiting the vortex-core tunnelling spectroscopy in YBa2Cu3O7−δ
Authors: Bruér Jens , Maggio-Aprile Ivan , Jenkins Nathan , Ristić Zoran , Erb Andreas , Berthod Christophe , Fischer Øystein , Renner Christoph
Published: March 2016

The observation by scanning tunnelling spectroscopy of Abrikosov vortex cores in the high-temperature superconductor YBa2Cu3O7−δ (Y123) has revealed a robust pair of electron-hole symmetric states at finite subgap energy. Their interpretation remains an open question because theory predicts a different signature in the vortex cores, characterized by a strong zero-bias conductance peak. Here, we present scanning tunnelling spectroscopy data on very homogeneous Y123 at 0.4 K revealing that the subgap features do not belong to vortices: they are actually observed everywhere along the surface with high spatial and energy reproducibility, even in the absence of magnetic field. Detailed analysis and modelling show that these states remain unpaired in the superconducting phase and belong to an incoherent channel, which contributes to the tunnelling signal in parallel with the superconducting density of states.
A new insight into high-strength Ti62Nb12.2Fe13.6Co6.4Al5.8 alloys with bimodal microstructure fabricated by semi-solid sintering
Authors: Liu L. H. , Yang C. , Kang L. M. , Qu S. G. , Li X. Q. , Zhang W. W. , Chen W. P. , Li Y. Y. , Li P. J. , Zhang L. C.
Published: March 2016

It is well known that semi-solid forming could only obtain coarse-grained microstructure in a few alloy systems with a low melting point, such as aluminum and magnesium alloys. This work presents that semi-solid forming could also produce novel bimodal microstructure composed of nanostructured matrix and micro-sized (CoFe)Ti2 twins in a titanium alloy, Ti62Nb12.2Fe13.6Co6.4Al5.8. The semi-solid sintering induced by eutectic transformation to form a bimodal microstructure in Ti62Nb12.2Fe13.6Co6.4Al5.8 alloy is a fundamentally different approach from other known methods. The fabricated alloy exhibits high yield strength of 1790 MPa and plastic strain of 15.5%. The novel idea provides a new insight into obtaining nano-grain or bimodal microstructure in alloy systems with high melting point by semi-solid forming and into fabricating high-performance metallic alloys in structural applications.
Looking for hotspots of marine metacommunity connectivity: a methodological framework
Authors: Melià Paco , Schiavina Marcello , Rossetto Marisa , Gatto Marino , Fraschetti Simonetta , Casagrandi Renato
Published: March 2016

Seascape connectivity critically affects the spatiotemporal dynamics of marine metacommunities. Understanding how connectivity patterns emerge from physically and biologically-mediated interactions is therefore crucial to conserve marine ecosystem functions and biodiversity. Here, we develop a set of biophysical models to explore connectivity in assemblages of species belonging to a typical Mediterranean community (Posidonia oceanicameadows) and characterized by different dispersing traits. We propose a novel methodological framework to synthesize species-specific results into a set of community connectivity metrics and show that spatiotemporal variation in magnitude and direction of the connections, as well as interspecific differences in dispersing traits, are key factors structuring community connectivity. We eventually demonstrate how these metrics can be used to characterize the functional role of each marine area in determining patterns of community connectivity at the basin level and to support marine conservation planning.
Multiplex congruence network of natural numbers
Authors: Yan Xiao-Yong , Wang Wen-Xu , Chen Guan-Rong , Shi Ding-Hua
Published: March 2016

Congruence theory has many applications in physical, social, biological and technological systems. Congruence arithmetic has been a fundamental tool for data security and computer algebra. However, much less attention was devoted to the topological features of congruence relations among natural numbers. Here, we explore the congruence relations in the setting of a multiplex network and unveil some unique and outstanding properties of the multiplex congruence network. Analytical results show that every layer therein is a sparse and heterogeneous subnetwork with a scale-free topology. Counterintuitively, every layer has an extremely strong controllability in spite of its scale-free structure that is usually difficult to control. Another amazing feature is that the controllability is robust against targeted attacks to critical nodes but vulnerable to random failures, which also differs from ordinary scale-free networks. The multi-chain structure with a small number of chain roots arising from each layer accounts for the strong controllability and the abnormal feature. The multiplex congruence network offers a graphical solution to the simultaneous congruences problem, which may have implication in cryptography based on simultaneous congruences. Our work also gains insight into the design of networks integrating advantages of both heterogeneous and homogeneous networks without inheriting their limitations.
Interface failure modes explain non-monotonic size-dependent mechanical properties in bioinspired nanolaminates
Authors: Song Z. Q. , Ni Y. , Peng L. M. , Liang H. Y. , He L. H.
Published: March 2016

Bioinspired discontinuous nanolaminate design becomes an efficient way to mitigate the strength-ductility tradeoff in brittle materials via arresting the crack at the interface followed by controllable interface failure. The analytical solution and numerical simulation based on the nonlinear shear-lag model indicates that propagation of the interface failure can be unstable or stable when the interfacial shear stress between laminae is uniform or highly localized, respectively. A dimensionless key parameter defined by the ratio of two characteristic lengths governs the transition between the two interface-failure modes, which can explain the non-monotonic size-dependent mechanical properties observed in various laminate composites.
Contagion on complex networks with persuasion
Authors: Huang Wei-Min , Zhang Li-Jie , Xu Xin-Jian , Fu Xinchu
Published: March 2016

The threshold model has been widely adopted as a classic model for studying contagion processes on social networks. We consider asymmetric individual interactions in social networks and introduce a persuasion mechanism into the threshold model. Specifically, we study a combination of adoption and persuasion in cascading processes on complex networks. It is found that with the introduction of the persuasion mechanism, the system may become more vulnerable to global cascades and the effects of persuasion tend to be more significant in heterogeneous networks than those in homogeneous networks: a comparison between heterogeneous and homogeneous networks shows that under weak persuasion, heterogeneous networks tend to be more robust against random shocks than homogeneous networks; whereas under strong persuasion, homogeneous networks are more stable. Finally, we study the effects of adoption and persuasion threshold heterogeneity on systemic stability. Though both heterogeneities give rise to global cascades, the adoption heterogeneity has an overwhelmingly stronger impact than the persuasion heterogeneity when the network connectivity is sufficiently dense.
Anatomical and functional gonadotrope networks in the teleost pituitary
Authors: Golan Matan , Martin Agnés O. , Mollard Patrice , Levavi-Sivan Berta
Published: March 2016

Mammalian pituitaries exhibit a high degree of intercellular coordination; this enables them to mount large-scale coordinated responses to various physiological stimuli. This type of communication has not been adequately demonstrated in teleost pituitaries, which exhibit direct hypothalamic innervation and expression of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in distinct cell types. We found that in two fish species, namely tilapia and zebrafish, LH cells exhibit close cell–cell contacts and form a continuous network throughout the gland. FSH cells were more loosely distributed but maintained some degree of cell–cell contact by virtue of cytoplasmic processes. These anatomical differences also manifest themselves at the functional level as evidenced by the effect of gap-junction uncouplers on gonadotropin release. These substances abolished the LH response to gonadotropin-releasing hormone stimulation but did not affect the FSH response to the same stimuli. Dye transfer between neighboring LH cells provides further evidence for functional coupling. The two gonadotropins were also found to be differently packaged within their corresponding cell types. Our findings highlight the evolutionary origin of pituitary cell networks and demonstrate how the different levels of cell–cell coordination within the LH and FSH cell populations are reflected in their distinct secretion patterns.
Investigation of Y/SBA Composite Molecular Sieves Morphology Control and Catalytic Performance for n-Pentane Aromatization
Authors: Shi Chun-Wei , Wu Wen-Yuan , Li Shuai , Bian Xue , Zhao Shan-lin , Pei Ming-Yuan
Published: March 2016

Using Y molecular sieve as the core, Y/SBA-15 composite molecular sieves were prepared by different crystallization methods in the paper. The growth process and morphologies of the composite molecular sieves were controlled by adjusting the synthesis factors. The structures and acidity of two kinds of composite molecular sieves were characterized by X-ray diffraction (XRD), N2 adsorption/desorption, transmission electron microscopy (TEM), and NH3-TPD. The catalysis performances of the composite molecular sieves were investigated in the aromatization reaction of n-pentane. The results indicated that the desired core-shell composite molecular sieves were obtained when the crystallization conditions were 36 hours, 100 °C and secondary crystallization. The aromatization results showed that core-shell composite molecular sieves had better selectivity for producing high application value xylenes compared to mixed-crystal composite molecular sieves.
Scaling Laws for Thin Films near the Superconducting-to-Insulating Transition
Authors: Tao Yong
Published: March 2016

We propose a Lagrangian function, which combines Landau-Ginzburg term and Chern-Simons term, for describing the competition between disorder and superconductivity. To describe the normal-to-superconducting transition in the thin superconducting films, we apply Wilson’s renormalization group methods into this Lagrangian function. Finally, we obtain a scaling law between critical temperature (Tc), film thickness (d), sheet resistance of the film at the normal state (Rs) and number density of the electrons at the normal state (N). Such a scaling law is in agreement with recent experimental investigations [Ivry, Y. et al., Physical Review B 90, 214515 (2014)]. Our finding may have potential benefits for improving transition temperature Tc.
KCa3.1 mediates dysfunction of tubular autophagy in diabetic kidneys via PI3k/Akt/mTOR signaling pathways
Authors: Huang Chunling , Lin Mike Z. , Cheng Delfine , Braet Filip , Pollock Carol A. , Chen Xin-Ming
Published: March 2016

Autophagy is emerging as an important pathway in many diseases including diabetic nephropathy. It is acknowledged that oxidative stress plays a critical role in autophagy dysfunction and diabetic nephropathy and KCa3.1 blockade ameliorates diabetic renal fibrosis through inhibiting TGF-β1 signaling pathway. To identify the role of KCa3.1 in dysfunctional tubular autophagy in diabetic nephropathy, human proximal tubular cells (HK2) transfected with scrambled or KCa3.1 siRNAs were exposed to TGF-β1 for 48 h, then autophagosome formation, the autophagy marker LC3, signaling molecules PI3K, Akt and mTOR and oxidative stress marker nitrotyrosine were examined respectively. In vivo, LC3, nitrotyrosine and phosphorylated mTOR were examined in kidneys of diabetic KCa3.1+/+ and KCa3.1−/− mice. The results demonstrated that TGF-β1 increased the formation of autophagic vacuoles, LC3 expression and phosphorylation of PI3K, Akt and mTOR in scrambled siRNA transfected HK2 cells compared to control cells, which was reversed in KCa3.1 siRNA transfected HK2 cells. In vivo, expression of LC3 and nitrotyrosine and phosphorylation of mTOR were significantly increased in kidneys of diabetic KCa3.1+/+ mice compared to non-diabetic mice, which were attenuated in kidneys of diabetic KCa3.1−/− mice. These results suggest that KCa3.1 activation contributes to dysfunctional tubular autophagy in diabetic nephropathy through PI3K/Akt/mTOR signaling pathways.
β-TrCP-mediated ubiquitination and degradation of liver-enriched transcription factor CREB-H
Authors: Cheng Yun , Gao Wei-Wei , Tang Hei-Man Vincent , Deng Jian-Jun , Wong Chi-Ming , Chan Chi-Ping , Jin Dong-Yan
Published: March 2016

CREB-H is an endoplasmic reticulum-resident bZIP transcription factor which critically regulates lipid homeostasis and gluconeogenesis in the liver. CREB-H is proteolytically activated by regulated intramembrane proteolysis to generate a C-terminally truncated form known as CREB-H-ΔTC, which translocates to the nucleus to activate target gene expression. CREB-H-ΔTC is a fast turnover protein but the mechanism governing its destruction was not well understood. In this study, we report on β-TrCP-dependent ubiquitination and proteasomal degradation of CREB-H-ΔTC. The degradation of CREB-H-ΔTC was mediated by lysine 48-linked polyubiquitination and could be inhibited by proteasome inhibitor. CREB-H-ΔTC physically interacted with β-TrCP, a substrate recognition subunit of the SCFβ-TrCP E3 ubiquitin ligase. Forced expression of β-TrCP increased the polyubiquitination and decreased the stability of CREB-H-ΔTC, whereas knockdown of β-TrCP had the opposite effect. An evolutionarily conserved sequence, SDSGIS, was identified in CREB-H-ΔTC, which functioned as the β-TrCP-binding motif. CREB-H-ΔTC lacking this motif was stabilized and resistant to β-TrCP-induced polyubiquitination. This motif was a phosphodegron and its phosphorylation was required for β-TrCP recognition. Furthermore, two inhibitory phosphorylation sites close to the phosphodegron were identified. Taken together, our work revealed a new intracellular signaling pathway that controls ubiquitination and degradation of the active form of CREB-H transcription factor.
Metal free carboamination of internal alkynes – an easy access to polysubstituted quinolines
Authors: Stopka T. , Niggemann M.
Published: March 2016

A synergistic Brønsted acid catalyst was used to intermolecularly generate vinyl cations for a C–C bond formation – Schmidt rearrangement – sequence.
A comparative computational study on hydrogen adsorption on the Ag+, Cu+, Mg2+, Cd2+, and Zn2+ cationic sites in zeolites
Authors: Kozyra Paweł , Piskorz Witold
Published: March 2016

Three essential factors have been identified (i–iii) for the interaction between H2 and Ag+, Cu+, Mg2+, Cd2+, and Zn2+ sites in zeolites: (i) donation from σH2 to the cation, (ii) π-backdonation from the cation to antibonding orbital of the molecule, and (iii) the interaction between H2 and oxygen framework which is crucial for H2 dissociation on Zn2+ sites.
Oxidomolybdenum complexes for acid catalysis using alcohols as solvents and reactants
Authors: Gomes Ana C. , Neves Patrícia , Cunha-Silva Luís , Valente Anabela A. , Gonçalves Isabel S. , Pillinger Martyn
Published: March 2016

With ethanol as solvent and reactant, a molybdenum (pre)catalyst promotes selective acid-catalysed reactions. Depending on the conditions, the MoVIcomplex is converted to MoVIoxidoalkoxido, MoVoxido-bridged dinuclear, and MoVIoctanuclear complexes.
Synthetic biology: insights into biological computation
Authors: Manzoni Romilde , Urrios Arturo , Velazquez-Garcia Silvia , de Nadal Eulàlia , Posas Francesc
Published: March 2016

Synthetic biology attempts to rationally engineer biological systems in order to perform desired functions. Our increasing understanding of biological systems guides this rational design, while the huge background in electronics for building circuits defines the methodology.
Polyurethane/58S bioglass nanofibers: synthesis, characterization, and in vitro evaluation
Authors: Hafezi Masoud , Safarian Shokofeh , Khorasani Mohammad Taghi , Abu Osman Noor Azuan
Published: March 2016

In this study, polyurethane nanofibers containing 5 and 10 wt% synthesized 58S bioglass were designed and fabricated by the electrospinning process.
Molecularly imprinted polymers for the analysis and removal of polychlorinated aromatic compounds in the environment: a review
Authors: Ndunda Elizabeth N. , Mizaikoff Boris
Published: March 2016

Molecularly imprinted polymers selective to polychlorinated aromatic compounds for application in environmental studies.
Synchronous intramolecular cycloadditions of the polyene macrolactam polyketide heronamide C
Authors: Booth Thomas J. , Alt Silke , Capon Robert J. , Wilkinson Barrie
Published: March 2016

Two spontaneous intramolecular cycloadditions lead to the biosynthetic congeners heronamide A and B.
Na+ doping induced changes in the reduction and charge transport characteristics of Al2O3-stabilized, CuO-based materials for CO2 capture
Authors: Imtiaz Q. , Abdala P. M. , Kierzkowska A. M. , van Beek W. , Schweiger S. , Rupp J. L. M. , Müller C. R.
Published: March 2016

We report on the influence of Na+ doping on the local structure, electronic properties and cyclic redox characteristics of alumina-stabilized copper oxide based materials for chemical looping combustion based CO2 capture architectures.
Thermophysical properties of LiCoO2–LiMn2O4blended electrode materials for Li-ion batteries
Authors: Gotcu Petronela , Seifert Hans J.
Published: March 2016

The first experimental thermophysical properties of two cathodes containing LiCoO2and LiMn2O4blended active materials combine application oriented and fundamental research.
Flexible magnetic filaments under the influence of external magnetic fields in the limit of infinite dilution
Authors: Cerdà Joan J. , Sánchez Pedro A. , Lüsebrink Daniel , Kantorovich Sofia , Sintes Tomàs
Published: March 2016

The presence of an external magnetic field enables the existence of bistable and multi-stable regions in the phase diagram of magnetic filaments.
First-principles study of line-defect-embedded zigzag graphene nanoribbons: electronic and magnetic properties
Authors: Guan Zhaoyong , Si Chen , Hu Shuanglin , Duan Wenhui
Published: March 2016

The spin density of H-6-LD-6-2H at the ferromagnetic ground state and the band structure of the ferromagnetic state calculated by hybrid functional HSE06 show its half-metallicity.
Understanding the morphology of solution processed fullerene-free small molecule bulk heterojunction blends
Authors: Namepetra Andrew , Kitching Elizabeth , Eftaiha Ala'a F. , Hill Ian G. , Welch Gregory C.
Published: March 2016

The impact of processing conditions on the morphological characteristics of bulk-heterojunction molecular blends prepared from small molecules based on diketopyrrolopyrrole (DPP) and perylene-diimide (PDI) chromophores have been investigated.
Access to highly active Ni–Pd bimetallic nanoparticle catalysts for C–C coupling reactions
Authors: Rai Rohit K. , Gupta Kavita , Tyagi Deepika , Mahata Arup , Behrens Silke , Yang Xinchun , Xu Qiang , Pathak Biswarup , Singh Sanjay K.
Published: March 2016

A facile access to highly active (with enhanced TONs/TOFs) and durable bimetallic Ni–Pd nanoparticle catalysts for C–C coupling reactions was achieved by tuning Ni to Pd atomic ratio in the Ni–Pd nanoparticle catalyst and therefore the electronic charge transfer from Ni to Pd.
A practical and scalable synthesis of carbohydrate based oxepines
Authors: Vannam Raghu , Peczuh Mark W.
Published: March 2016

A versatile synthetic route that converts pyranoses to oxepines via reductive elimination of septanosyl bromides is reported.
Enhancement of the performance of constructed wetlands for wastewater treatment in winter: the effect of Tubifex tubifex
Authors: Kang Yan , Zhang Jian , Xie Huijun , Guo Zizhang , Li Pengfei , Cheng Cheng , Lv Lu
Published: March 2016

An improved constructed wetland (CW) with the addition ofTubifex tubifexin winter was studied in laboratory batch systems. The outcomes of this study indicate that the potential use ofTubifex tubifexcould improve the ecosystem and water purification by CWs in winter.
Highly thermally conductive polymer nanocomposites based on boron nitride nanosheets decorated with silver nanoparticles
Authors: Wang Fangfang , Yao Yimin , Zeng Xiaoliang , Huang Tao , Sun Rong , Xu Jianbin , Wong Ching-Ping
Published: March 2016

The interfacial thermal resistance among boron nitride nanosheets are reduced by sintering silver nanoparticles deposited on boron nitride nanosheets surfaces, beneficial for the forming networks.
Tailoring of ammonia reduced graphene oxide into amine functionalized graphene quantum dots through a Hofmann rearrangement
Authors: Dai Yongqiang , Pang Hao , Huang Jianheng , Yang Yong , Huang Hao , Wang Kun , Ma Zhe , Liao Bing
Published: March 2016

A Hofmann rearrangement tailored and exfoliated multi-layered ammonia reduced graphene oxide into amine functionalized graphene quantum dots.
Maltitol-based biodegradable polyesters with tailored degradation and controlled release for bone regeneration
Authors: Natarajan Janeni , Madras Giridhar , Chatterjee Kaushik
Published: March 2016

Polyesters based on maltitol and different dicarboxylic acids promoted mineral deposition and directed cells towards osteogenic lineage.
Micro- and mesoscopic structural features of a bio-based choline-amino acid ionic liquid
Authors: Russina Olga , De Santis Serena , Gontrani Lorenzo
Published: March 2016

The structure of bio-based choline–norleucine ionic liquid has been explored by means of combined x-ray diffraction and MD simulations.
RAFT copolymerization of a phosphorus-containing monomer with α-hydroxy phosphonate and methyl methacrylate
Authors: Tian Chun , Xu Tianchi , Zhang Lifen , Cheng Zhenping , Zhu Xiulin
Published: March 2016

RAFT copolymerization of a phosphorus-containing monomer with α-hydroxy phosphonate PHMA and MMA was successfully conducted and the resultant well-defined copolymer material shows good superior flame-retardant properties and hydrophilicity.
Generation of hydrogen peroxide and hydroxyl radical resulting from oxygen-dependent oxidation of l-ascorbic acid via copper redox-catalyzed reactions
Authors: Zhou Peng , Zhang Jing , Zhang Yongli , Liu Ya , Liang Juan , Liu Bei , Zhang Wei
Published: March 2016

The generation of hydrogen peroxide (H2O2) and hydroxyl radical (HO˙) during the oxidation of l-ascorbic acid (l-AA) by oxygen with copper as a catalyst.
Contrary interfacial effects for textured and non-textured multilayer solid oxide electrolytes
Authors: Yao Lei , Nishijima Hiroki , Pan Wei
Published: March 2016

We report a negative and a positive interfacial effect for textured and non-textured polycrystalline Ce0.8Sm0.2O2−δ/Al2O3 multilayered solid electrolytes which are due to differences in microstructures.
Ideal dielectric thermally conductive bismaleimide nanocomposites filled with polyhedral oligomeric silsesquioxane functionalized nanosized boron nitride
Authors: Gu Junwei , Liang Chaobo , Dang Jing , Dong Wencai , Zhang Qiuyu
Published: March 2016

NH2–POSS functionalized nanosized boron nitride fillers were performed to fabricate thermally conductive bismaleimide/diallylbisphenol A (BMI/DABA) nanocomposites combining excellent dielectric properties and outstanding thermal stabilities.
Bioinspired aerobic oxidation of alcohols with a bifunctional ligand based on bipyridine and TEMPO
Authors: Wang Lianyue , Bie Zhixing , Shang Sensen , Lv Ying , Li Guosong , Niu Jingyang , Gao Shuang
Published: March 2016

A new bifunctional ligand bearing bipyridine and TEMPO in combination with copper for the oxidation of alcohols was developed.
Synthesis and characterization of calcium lanthanum sulfide via a wet chemistry route followed by thermal decomposition
Authors: Li Yiyu , Zhang Lihua , Wu Yiquan
Published: March 2016

In the present research, the ternary sulfide CaLa2S4 has been successfully synthesized via a wet chemistry method followed by thermal decomposition and characterized to investigate the microstructural features and optical properties.
A supramolecularly tunable chiral diphosphine ligand: application to Rh and Ir-catalyzed enantioselective hydrogenation
Authors: Zhang Xi-Chang , Hu Yi-Hu , Chen Chuan-Fu , Fang Qiang , Yang Li-Yao , Lu Ying-Bo , Xie Lin-Jie , Wu Jing , Li Shijun , Fang Wenjun
Published: March 2016

A supramolecularly tunable chiral bisphosphine ligand bearing two pyridyl-containing crown ethers was synthesized and applied in Rh or Ir-catalyzed asymmetric hydrogenations in high yields with excellent ee values (90–99% ee).
Photon upconversion in Yb3+–Tb3+ and Yb3+–Eu3+ activated core/shell nanoparticles with dual-band excitation
Authors: Dong Hao , Sun Ling-Dong , Wang Ye-Fu , Xiao Jia-Wen , Tu Datao , Chen Xueyuan , Yan Chun-Hua
Published: March 2016

Photon upconversion emission in a series of Yb3+–Tb3+ and Yb3+–Eu3+ activated nanoparticles were investigated in this study.