bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical abundances from planetary nebulae in local spiral galaxies
Authors: Richer Michael G. , McCall Marshall L. 
Published: May 2017

AbstractWhile the chemical abundances observed in bright planetary nebulae in local spiral galaxies are less varied than their counterparts in dwarfs, they provide new insight. Their helium abundances are typically enriched by less than 50% compared to the primordial abundance. Nitrogen abundances always show some level of secondary enrichment, but the absolute enrichment is not extreme. In particular, type I PNe are rare among the bright PNe in local spirals. The oxygen and neon abundances are very well correlated and follow the relation between these abundances observed in star-forming galaxies, implying that either the progenitor stars of these PNe modify neither abundance substantially or that they modify both to maintain the ratio (not predicted by theory). According to theory, these results imply that the progenitor stars of bright PNe in local spirals have masses of about 2 M⊙ or less. If so, the progenitors of these PNe have substantial lifetimes that allow us to use them to study the recent history of their host galaxies, including gravitational interactions with their neighbours. Areas that require further study include the systematic differences observed between spectroscopy obtained through slits and fibres, the uncertainties assigned to chemical abundances, including effects due to ionization correction factors, and the physics that gives rise to the PN luminosity function. Indeed, so long as we lack an understanding of how the last arises, our ability to use bright PNe as probes to understand the evolution of their host galaxies will remain limited.
Nonlinear convective pulsation models of type II Cepheids
Authors: Smolec Radoslaw 
Published: May 2017

AbstractWe present a grid of nonlinear convective pulsation models of type-II Cepheids: BL Her stars, W Vir stars and RV Tau stars. The models have 0.6M⊙ and cover a wide range of luminosities, effective temperatures and chemical compositions. The most important result is the detection of two domains in the HR diagram, in which period doubling effect is present. First domain, with pulsation periods in between 2 d and 5.5 d, was also detected in earlier radiative computations. The first star showing the period doubling effect with period in the predicted range (≈ 2.4 d) was discovered recently. The second domain extends for periods longer than 9.5 d but so far no period-doubled type-II Cepheid that could be associated with this domain was discovered. We also detect very small domains in which modulation of pulsation is possible. The origin of these phenomena may be assocaited with half-integer resonances between radial pulsation modes. In the most luminous models a dynamical instability is detected, which indicates that pulsation driven mass loss is important process occurring in type-II Cepheids.
An Appropriate Stepping Stone? A case study into student and teacher perceptions of the value of the WJEC Level 1 Certificate in Latin
Authors: McPherson Lisa 
Published: May 2017

During my second placement on the PGCE in Latin with Classics, the Head of Classics explained the curriculum plan for Latin, and the use of the WJEC Level 1 Certificate in Latin which she had implemented for the students in Year 9. She was keen for the students to receive recognition for their effort in Latin and yet concerned that the pressure of an additional external exam might detract from the students’ enjoyment of the subject. I was unaware of the possibility for external exams outside of GCSE and A Level and I was fascinated by what role the certificate might play for the students as they progressed through their education.
PLSCR1/IP3R1/Ca2+ axis contributes to differentiation of primary AML cells induced by wogonoside
Authors: Li Hui , Xu Jingyan , Zhou Yuxin , Liu Xiao , Shen L e , Zhu Y u , Li Zhiyu , Wang Xiaotang , Guo Qinglong , Hui Hui 
Published: May 2017

AbstractMultiple lines of evidence have demonstrated that increased expression of phospholipid scramblase 1 (PLSCR1) is involved in the differentiation of acute myeloid leukemia (AML) cells by several differentiation-inducing agents including ATRA and phorbol 12-myristate 13-acetate. However, none of these agents can achieve nonhomogenous subcellular distribution of PLSCR1. We have demonstrated that wogonoside possesses differentiation and anti-leukemic effects in AML cell lines by promoting PLSCR1 trafficking into nucleus. Here we report that wogonoside promotes the expression of PLSCR1 and enhances its nuclear translocation and binding to the 1, 4, 5-trisphosphate receptor 1 (IP3R1) promoter in AML patient-derived primary cells. Wogonoside activates IP3R1, in turn, promotes release of Ca2+ from endoplasmic reticulum, and eventually leads to cell differentiation. Our in vivo study further confirms that wogonoside can promote PLSCR1 and IP3R1 expression in primary AML cells and reduce the AML cell counts in engrafted nonobese diabetic/severe combined immunodeficient mice. Taken together, our findings provide new insight into the mechanism of wogonoside-induced differentiation and anti-leukemic effect on primary AML cells, suggesting the therapeutic potential of wogonoside for AML, especially for non-APL AML.
Acidic pH is essential for maintaining mast cell secretory granule homeostasis
Authors: Pejler Gunnar , Hu Frisk Jun Mei , Sjöström Daniel , Paivandy Aida , Öhrvik Helena 
Published: May 2017

AbstractIt has been recognized for a long time that the secretory granules of mast cells are acidic, but the functional importance of maintaining an acidic pH in the mast cell granules is not fully understood. Here we addressed this issue by examining the effects of raising the pH of the mast cell secretory granules. Mast cells were incubated with bafilomycin A1, an inhibitor of the vacuolar-type ATPase proton pump. Supporting a role of vacuolar-type ATPase in mast cell granule acidification, bafilomycin A1 treatment caused a robust increase in granule pH. This was accompanied by marked effects on mast cell granules, including swelling and acquisition of vacuole-like morphology. Moreover, bafilomycin A1 caused extensive, yet selective effects on the granule content. These included aberrant processing of pro-carboxypeptidase A3 and a reduction in the level of intracellular histamine, the latter being accompanied by an increase in extracellular histamine. In contrast, the storage of β-hexosaminidase, a prototype lysosomal hydrolase known to be stored in mast cell granules, was not affected by abrogation of granule acidification. Moreover, bafilomycin A1 caused a reduction of tryptase enzymatic activity and appearance of tryptase degradation products. Tryptase inhibition prevented the formation of such degradation products, suggesting that the pH elevation causes tryptase to undergo autoproteolysis. Taken together, our findings reveal that mast cell secretory granule homeostasis is critically dependent on an acidic milieu.
High-efficiency and high-power rechargeable lithium–sulfur dioxide batteries exploiting conventional carbonate-based electrolytes
Authors: Park Hyeokjun , Lim Hee-Dae , Lim Hyung-Kyu , Seong Won Mo , Moon Sehwan , Ko Youngmin , Lee Byungju , Bae Youngjoon , Kim Hyungjun , Kang Kisuk 
Published: May 2017

AbstractShedding new light on conventional batteries sometimes inspires a chemistry adoptable for rechargeable batteries. Recently, the primary lithium-sulfur dioxide battery, which offers a high energy density and long shelf-life, is successfully renewed as a promising rechargeable system exhibiting small polarization and good reversibility. Here, we demonstrate for the first time that reversible operation of the lithium-sulfur dioxide battery is also possible by exploiting conventional carbonate-based electrolytes. Theoretical and experimental studies reveal that the sulfur dioxide electrochemistry is highly stable in carbonate-based electrolytes, enabling the reversible formation of lithium dithionite. The use of the carbonate-based electrolyte leads to a remarkable enhancement of power and reversibility; furthermore, the optimized lithium-sulfur dioxide battery with catalysts achieves outstanding cycle stability for over 450 cycles with 0.2 V polarization. This study highlights the potential promise of lithium-sulfur dioxide chemistry along with the viability of conventional carbonate-based electrolytes in metal-gas rechargeable systems.
Fast oxygen diffusion and iodide defects mediate oxygen-induced degradation of perovskite solar cells
Authors: Aristidou Nicholas , Eames Christopher , Sanchez-Molina Irene , Bu Xiangnan , Kosco Jan , Islam M. Saiful , Haque Saif A. 
Published: May 2017

AbstractMethylammonium lead halide perovskites are attracting intense interest as promising materials for next-generation solar cells, but serious issues related to long-term stability need to be addressed. Perovskite films based on CH3NH3PbI3 undergo rapid degradation when exposed to oxygen and light. Here, we report mechanistic insights into this oxygen-induced photodegradation from a range of experimental and computational techniques. We find fast oxygen diffusion into CH3NH3PbI3 films is accompanied by photo-induced formation of highly reactive superoxide species. Perovskite films composed of small crystallites show higher yields of superoxide and lower stability. Ab initio simulations indicate that iodide vacancies are the preferred sites in mediating the photo-induced formation of superoxide species from oxygen. Thin-film passivation with iodide salts is shown to enhance film and device stability. The understanding of degradation phenomena gained from this study is important for the future design and optimization of stable perovskite solar cells.
Paramagnetic resonance in spin-polarized disordered Bose-Einstein condensates
Authors: Kovalev V. M. , Savenko I. G. 
Published: May 2017

AbstractWe study the pseudo-spin density response of a disordered two-dimensional spin-polarized Bose gas to weak alternating magnetic field, assuming that one of the spin states of the doublet is macroscopically occupied and Bose-condensed while the occupation of the other state remains much smaller. We calculate spatial and temporal dispersions of spin susceptibility of the gas taking into account spin-flip processes due to the transverse-longitudinal splitting, considering microcavity exciton polaritons as a testbed. Further, we use the Bogoliubov theory of weakly-interacting gases and show that the time-dependent magnetic field power absorption exhibits double resonance structure corresponding to two particle spin states (contrast to paramagnetic resonance in regular spin-polarized electron gas). We analyze the widths of these resonances caused by scattering on the disorder and show that, in contrast with the ballistic regime, in the presence of impurities, the polariton scattering on them is twofold: scattering on the impurity potential directly and scattering on the spatially fluctuating condensate density caused by the disorder. As a result, the width of the resonance associated with the Bose-condensed spin state can be surprisingly narrow in comparison with the width of the resonance associated with the non-condensed state.
Automatic Segmentation of Kidneys using Deep Learning for Total Kidney Volume Quantification in Autosomal Dominant Polycystic Kidney Disease
Authors: Sharma Kanishka , Rupprecht Christian , Caroli Anna , Aparicio Maria Carolina , Remuzzi Andrea , Baust Maximilian , Navab Nassir 
Published: May 2017

AbstractAutosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common inherited disorder of the kidneys. It is characterized by enlargement of the kidneys caused by progressive development of renal cysts, and thus assessment of total kidney volume (TKV) is crucial for studying disease progression in ADPKD. However, automatic segmentation of polycystic kidneys is a challenging task due to severe alteration in the morphology caused by non-uniform cyst formation and presence of adjacent liver cysts. In this study, an automated segmentation method based on deep learning has been proposed for TKV computation on computed tomography (CT) dataset of ADPKD patients exhibiting mild to moderate or severe renal insufficiency. The proposed method has been trained (n = 165) and tested (n = 79) on a wide range of TKV (321.2–14,670.7 mL) achieving an overall mean Dice Similarity Coefficient of 0.86 ± 0.07 (mean ± SD) between automated and manual segmentations from clinical experts and a mean correlation coefficient (ρ) of 0.98 (p < 0.001) for segmented kidney volume measurements in the entire test set. Our method facilitates fast and reproducible measurements of kidney volumes in agreement with manual segmentations from clinical experts.
MiR-520b as a novel molecular target for suppressing stemness phenotype of head-neck cancer by inhibiting CD44
Authors: Lu Ya-Ching , Cheng Ann-Joy , Lee Li-Yu , You Guo-Rung , Li Yan-Liang , Chen Hsin-Ying , Chang Joseph T. 
Published: May 2017

AbstractCancer stem cells preferentially acquire the specific characteristics of stress tolerance and high mobility, allowing them to progress to a therapy-refractive state. To identify a critical molecule to regulate cancer stemness is indispensable to erratically cure cancer. In this study, we identified miR-520b as a novel molecular target to suppress head-neck cancer (HNC) with stemness phenotype. MiR-520b inhibited cellular migration and invasion via the mechanism of epithelial-mesenchymal transition. It also sensitized cells to therapeutic drug and irradiation. Significantly, miR-520b suppressed spheroid cell formation, as well as reduced expressions of multiple stemness regulators (Nestin, Twist, Nanog, Oct4). The CD44 molecule was identified as a direct target of miR-520b, as shown by the reverse correlative expressions, the response to miR-520 modulation, the luciferase reporter assay, and the functional rescue analyses. These cellular results were confirmed by a tumor xenograft mice study. Administration of miR-520b dramatically restrained tumorigenesis and liver colonization. Conversely, miR-520b silencing led to an acceleration of tumor growth. Taken together, our study demonstrated that miR-520b inhibits the malignancy of HNC through regulation of cancer stemness conversion by targeting CD44. MiR-520b may serve as an emerging therapeutic target that may be further developed for the intervention of refractory HNC.
Cancer cachexia associates with a systemic autophagy-inducing activity mimicked by cancer cell-derived IL-6 trans-signaling
Authors: Pettersen Kristine , Andersen Sonja , Degen Simone , Tadini Valentina , Grosjean Joël , Hatakeyama Shinji , Tesfahun Almaz N. , Moestue Siver , Kim Jana , Nonstad Unni , Romundstad Pål R. , Skorpen Frank , Sørhaug Sveinung , Amundsen Tore , Grønberg Bjørn H. , Strasser Florian , Stephens Nathan , Hoem Dag , Molven Anders , Kaasa Stein , Fearon Kenneth , Jacobi Carsten , Bjørkøy Geir 
Published: May 2017

AbstractThe majority of cancer patients with advanced disease experience weight loss, including loss of lean body mass. Severe weight loss is characteristic for cancer cachexia, a condition that significantly impairs functional status and survival. The underlying causes of cachexia are incompletely understood, and currently no therapeutic approach can completely reverse the condition. Autophagy coordinates lysosomal destruction of cytosolic constituents and is systemically induced by starvation. We hypothesized that starvation-mimicking signaling compounds secreted from tumor cells may cause a systemic acceleration of autophagy during cachexia. We found that IL-6 secreted by tumor cells accelerates autophagy in myotubes when complexed with soluble IL-6 receptor (trans-signaling). In lung cancer patients, were cachexia is prevalent, there was a significant correlation between elevated IL-6 expression in the tumor and poor prognosis of the patients. We found evidence for an autophagy-inducing bioactivity in serum from cancer patients and that this is clearly associated with weight loss. Importantly, the autophagy-inducing bioactivity was reduced by interference with IL-6 trans-signaling. Together, our findings suggest that IL-6 trans-signaling may be targeted in cancer cachexia.
Cardiolipin content, linoleic acid composition, and tafazzin expression in response to skeletal muscle overload and unload stimuli
Authors: Fajardo Val A. , Mikhaeil John S. , Leveille Cameron F. , Saint Caitlin , LeBlanc Paul J. 
Published: May 2017

AbstractCardiolipin (CL) is a unique mitochondrial phospholipid that, in skeletal muscle, is enriched with linoleic acid (18:2n6). Together, CL content and CL 18:2n6 composition are critical determinants of mitochondrial function. Skeletal muscle is comprised of slow and fast fibers that have high and low mitochondrial content, respectively. In response to overloading and unloading stimuli, these muscles undergo a fast-to-slow oxidative fiber type shift and a slow-to-fast glycolytic fiber type shift, respectively, with a concomitant change in mitochondrial content. Here, we examined changes in CL content and CL 18:2n6 composition under these conditions along with tafazzin (Taz) protein, which is a transacylase enzyme that generates CL lipids enriched with 18:2n6. Our results show that CL content, CL 18:2n6 composition, and Taz protein content increased with an overload stimulus in plantaris. Conversely, CL content and CL 18:2n6 composition was reduced with an unloaded stimulus in soleus. Interestingly, Taz protein was increased in the unloaded soleus, suggesting that Taz may provide some form of compensation for decreased CL content and CL 18:2n6 composition. Together, this study highlights the dynamic nature of CL and Taz in skeletal muscle, and future studies will examine the physiological significance behind the changes in CL content, CL 18:2n6 and Taz.
A Split Ring Resonator Dielectric Probe for Near-Field Dielectric Imaging
Authors: Isakov Dmitry , Stevens Chris J. , Castles Flynn , Grant Patrick S. 
Published: May 2017

AbstractA single split-ring resonator (SRR) probe for 2D surface mapping and imaging of relative dielectric permittivity for the characterisation of composite materials has been developed. The imaging principle, the analysis and the sensitivity of the SRR surface dielectric probe data is described. The surface dielectric properties of composite materials in the frequency range 1–3 GHz have been measured based on the magnetic resonance frequency of the transmission loss of the SRR dielectric probe when in contact with the surface. The SRR probe performance was analysed analytically and using full-wave simulation, and predictions showed close agreement with experiment for composite materials with spatially varying dielectric permittivity manufactured by 3D printing. The spatial and permittivity resolution of the SRR dielectric probe were controlled by the geometrical parameters of the SRR which provided flexibility to tune the SRR probe. The best accuracy of the dielectric permittivity measurements was within 5%.
Spin-orbit-torque-induced magnetic domain wall motion in Ta/CoFe nanowires with sloped perpendicular magnetic anisotropy
Authors: Zhang Yue , Luo Shijiang , Yang Xiaofei , Yang Chang 
Published: May 2017

AbstractIn materials with the gradient of magnetic anisotropy, spin-orbit-torque-induced magnetization behaviour has attracted attention because of its intriguing scientific principle and potential application. Most of the magnetization behaviours microscopically originate from magnetic domain wall motion, which can be precisely depicted using the standard cooperative coordinate method (CCM). However, the domain wall motion in materials with the gradient of magnetic anisotropy using the CCM remains lack of investigation. In this paper, by adopting CCM, we established a set of equations to quantitatively depict the spin-orbit-torque-induced motion of domain walls in a Ta/CoFe nanotrack with weak Dzyaloshinskii–Moriya interaction and magnetic anisotropy gradient. The equations were solved numerically, and the solutions are similar to those of a micromagnetic simulation. The results indicate that the enhanced anisotropy along the track acts as a barrier to inhibit the motion of the domain wall. In contrast, the domain wall can be pushed to move in a direction with reduced anisotropy, with the velocity being accelerated by more than twice compared with that for the constant anisotropy case. This substantial velocity manipulation by anisotropy engineering is important in designing novel magnetic information devices with high reading speeds.
Interplay between Alternative Splicing and Alternative Polyadenylation Defines the Expression Outcome of the Plant Unique OXIDATIVE TOLERANT-6 Gene
Authors: Li Qingshun Q. , Liu Zhaoyang , Lu Wenjia , Liu Man 
Published: May 2017

AbstractPre-mRNA alternative splicing and alternative polyadenylation have been implicated to play important roles during eukaryotic gene expression. However, much remains unknown regarding the regulatory mechanisms and the interactions of these two processes in plants. Here we focus on an Arabidopsis gene OXT6 (Oxidative Tolerant-6) that has been demonstrated to encode two proteins through alternative splicing and alternative polyadenylation. Specifically, alternative polyadenylation at Intron-2 of OXT6 produces a transcript coding for AtCPSF30, an Arabidopsis ortholog of 30 kDa subunit of the Cleavage and Polyadenylation Specificity Factor. On the other hand, alternative splicing of Intron-2 generates a longer transcript encoding a protein named AtC30Y, a polypeptide including most part of AtCPSF30 and a YT521B domain. To investigate the expression outcome of OXT6 in plants, a set of mutations were constructed to alter the splicing and polyadenylation patterns of OXT6. Analysis of transgenic plants bearing these mutations by quantitative RT-PCR revealed a competition relationship between these two processes. Moreover, when both splice sites and poly(A) signals were mutated, polyadenylation became the preferred mode of OXT6 processing. These results demonstrate the interplay between alternative splicing and alternative polyadenylation, and it is their concerted actions that define a gene’s expression outcome.
Fluorescence dynamics of the biosynthesized CdSe quantum dots in Candida utilis
Authors: Tian Li-Jiao , Zhou Nan-Qing , Liu Xian-Wei , Zhang Xing , Zhu Ting-Ting , Li Ling-Li , Li Wen-Wei , Yu Han-Qing 
Published: May 2017

AbstractOrganisms served as factories of bio-assembly of nanoparticles attracted a lot of attentions due to the safe, economic and environmental-benignity traits, especially the fabrication of the super fluorescence properties quantum dots (QDs). However, information about the developmental dynamics of QDs in living organisms is still lacking. In this work, we synthesized cadmium-selenium (CdSe) QDs in Candida utilis WSH02-08, and then tracked and quantitatively characterized the developmental dynamics (photoactivation, photostable and photobleaching processes) of bio-QDs by translating fluorescence microscopy movies into visual quantitative curve. These findings shed light on the fluorescence properties of the bio-assembled QDs and are expected to accelerate the applications of the synthesized QDs in vivo. It provided a new way to screen bio-QDs and monitor the quality of QDs in vivo.