bluuebunny/crossref_metadata_2025_split huggingface dataset:
Squeezing dynamics of a nanowire system with spin-orbit interaction
Authors: Mohamed R. I. , Farouk Ahmed , Homid A. H. , El-Kalaawy O. H. , Abdel-Aty Abdel-Haleem , Abdel-Aty M. , Ghose S. 
Published: July 2018

AbstractWe analyze the dynamics of squeezing in a ballistic quantum wire with Rashba spin-orbit interaction in the presence of both strong and weak magnetic fields and for different initial states of the system. Compared to the more standard measure of squeezing based on variances, we show that entropy squeezing is a more sensitive measure. Our results show that there is a strong relationship between the spin-orbit interaction and the strength of entropy squeezing. Furthermore, there is a relationship between the initial state and the number of squeezed components. This allows new knobs to control the strength and the component of entropy squeezing in a nanowire system.
Inhibition of the precursor and mature forms of HIV-1 protease as a tool for drug evaluation
Authors: Humpolíčková Jana , Weber Jan , Starková Jana , Mašínová Eva , Günterová Jana , Flaisigová Iva , Konvalinka Jan , Majerová Taťána 
Published: July 2018

AbstractHIV-1 protease (PR) is a homodimeric enzyme that is autocatalytically cleaved from the Gag-Pol precursor. Known PR inhibitors bind the mature enzyme several orders of magnitude more strongly than the PR precursor. Inhibition of PR at the precursor level, however, may stop the process at its rate-limiting step before the proteolytic cascade is initiated. Due to its structural heterogeneity, limited solubility and autoprocessing, the PR precursor is difficult to access by classical methods, and limited knowledge regarding precursor inhibition is available. Here, we describe a cell-based assay addressing precursor inhibition. We used a reporter molecule containing the transframe (TFP) and p6* peptides, PR, and N-terminal fragment of reverse transcriptase flanked by the fluorescent proteins mCherry and EGFP on its N- and C- termini, respectively. The level of FRET between EGFP and mCherry indicates the amount of unprocessed reporter, allowing specific monitoring of precursor inhibition. The inhibition can be quantified by flow cytometry. Additionally, two microscopy techniques confirmed that the reporter remains unprocessed within individual cells upon inhibition. We tested darunavir, atazanavir and nelfinavir and their combinations against wild-type PR. Shedding light on an inhibitor’s ability to act on non-mature forms of PR may aid novel strategies for next-generation drug design.
Thermostatic properties of nitrate molten salts and their solar and eutectic mixtures
Authors: D’Aguanno B. , Karthik M. , Grace A. N. , Floris A. 
Published: July 2018

AbstractNitrate molten salts are extensively used for sensible heat storage in Concentrated Solar Power (CSP) plants and thermal energy storage (TES) systems. They are the most promising materials for latent heat storage applications. By combining classical molecular dynamics and differential scanning calorimetry experiments, we present a systematic study of all thermostatic, high temperature properties of pure KNO3and NaNO3salts and their eutectic and ”solar salt” mixtures, technologically relevant. We first study, in solid and liquid regimes, their mass densities, enthalpies, thermal expansion coefficients and isothermal compressibilities. We then analyze thecPandcVspecific heats of the pure salts and of the liquid phase of the mixtures. Our theoretical results allow to resolve a long-standing experimental uncertainty about thecP(T) thermal behaviour of these systems. In particular, they revisit empirical laws on thecP(T) behaviour, extensively used at industrial level in the design of TES components employing the ”solar salt” as main storage material. Our findings, numerically precise and internally consistent, can be used as a reference for the development of innovative nanomaterials based on nitrate molten salts, crucial in technologies as CSP, waste heat recovery, and advanced adiabatic compressed air energy storage.
Gas Phase Chemical Evolution of Uranium, Aluminum, and Iron Oxides
Authors: Koroglu Batikan , Wagnon Scott , Dai Zurong , Crowhurst Jonathan C. , Armstrong Michael R. , Weisz David , Mehl Marco , Zaug Joseph M. , Radousky Harry B. , Rose Timothy P. 
Published: July 2018

AbstractWe use a recently developed plasma-flow reactor to experimentally investigate the formation of oxide nanoparticles from gas phase metal atoms during oxidation, homogeneous nucleation, condensation, and agglomeration processes. Gas phase uranium, aluminum, and iron atoms were cooled from 5000 K to 1000 K over short-time scales (∆t < 30 ms) at atmospheric pressures in the presence of excess oxygen. In-situ emission spectroscopy is used to measure the variation in monoxide/atomic emission intensity ratios as a function of temperature and oxygen fugacity. Condensed oxide nanoparticles are collected inside the reactor for ex-situ analyses using scanning and transmission electron microscopy (SEM, TEM) to determine their structural compositions and sizes. A chemical kinetics model is also developed to describe the gas phase reactions of iron and aluminum metals. The resulting sizes and forms of the crystalline nanoparticles (FeO-wustite, eta-Al2O3, UO2, and alpha-UO3) depend on the thermodynamic properties, kinetically-limited gas phase chemical reactions, and local redox conditions. This work shows the nucleation and growth of metal oxide particles in rapidly-cooling gas is closely coupled to the kinetically-controlled chemical pathways for vapor-phase oxide formation.
Circular-polarized-light-induced spin polarization characterized for the Dirac-cone surface state at W(110) with C2v symmetry
Authors: Miyamoto K. , Wortelen H. , Okuda T. , Henk J. , Donath M. 
Published: July 2018

AbstractThe C2v surface symmetry of W(110) strongly influences a spin-orbit-induced Dirac-cone-like surface state and its characterization by spin- and angle-resolved photoelectron spectroscopy. In particular, using circular polarized light, a distinctive k-dependent spin texture is observed along the $$\overline{{\boldsymbol{\Gamma }}{\boldsymbol{H}}}$$

Γ
H

¯

direction of the surface Brillouin zone. For all spin components Px, Py, and Pz, non-zero values are detected, while the initial-state spin polarization has only a Py component due to mirror symmetry. The observed complex spin texture of the surface state is controlled by transition matrix element effects, which include orbital symmetries of the involved electron states as well as the geometry of the experimental set-up.
Isolation of Cottonseed Extracts That Affect Human Cancer Cell Growth
Authors: Cao Heping , Sethumadhavan Kandan , Bland John M. 
Published: July 2018

AbstractCottonseeds are classified as glanded or glandless seeds depending on the presence or absence of gossypol glands. Glanded cottonseed has anticancer property and glandless cottonseed was reported to cause cancer in one animal study. It is important to investigate the effect of bioactive components from cottonseeds. Our objectives were to isolate ethanol extracts from cottonseeds and investigate their effects on human cancer cells. A protocol was developed for isolating bioactive extracts from seed coat and kernel of glanded and glandless cottonseeds. HPLC-MS analyzed the four ethanol extracts but only quercetin was identified in the glandless seed coat extract. Residual gossypol was detected in the glanded and glandless seed kernel extracts and but only in the glanded seed coat extract. Ethanol extracts were used to treat human cancer cells derived from breast and pancreas followed by MTT assay for cell viability. Ethanol extracts from glanded and glandless cottonseed kernels and gossypol significantly decreased breast cancer cell mitochondrial activity. Ethanol extract from glanded cottonseed kernel and gossypol also significantly decreased pancreas cancer cell mitochondrial activity. These results suggest that ethanol extracts from cottonseeds, like gossypol, contain anticancer activities.
The morphospace of language networks
Authors: Seoane Luís F. , Solé Ricard 
Published: July 2018

AbstractWhat is the nature of language? How has it evolved in different species? Are there qualitative, well-defined classes of languages? Most studies of language evolution deal in a way or another with such theoretical contraption and explore the outcome of diverse forms of selection on the communication matrix that somewhat optimizes communication. This framework naturally introduces networks mediating the communicating agents, but no systematic analysis of the underlying landscape of possible language graphs has been developed. Here we present a detailed analysis of network properties on a generic model of a communication code, which reveals a rather complex and heterogeneous morphospace of language graphs. Additionally, we use curated data of English words to locate and evaluate real languages within this morphospace. Our findings indicate a surprisingly simple structure in human language unless particles with the ability of naming any other concept are introduced in the vocabulary. These results refine and for the first time complement with empirical data a lasting theoretical tradition around the framework ofleast effort language.
Efficient Blue-emitting Phosphor SrLu2O4:Ce3+ with High Thermal Stability for Near Ultraviolet (~400 nm) LED-Chip based White LEDs
Authors: Zhang Sheng , Hao Zhendong , Zhang Liangliang , Pan Guo-Hui , Wu Huajun , Zhang Xia , Luo Yongshi , Zhang Ligong , Zhao Haifeng , Zhang Jiahua 
Published: July 2018

AbstractBlue-emitting phosphors for near ultraviolet (NUV) based tri-color RGB phosphor blend converted white light emitting diodes (LEDs) have been extensively investigated in the past few years. LED chip peaked near 400 nm is the most efficient among the NUV chips currently. However, most of blue phosphors show inefficient excitation around 400 nm. Herein, a novel blue phosphor SrLu2O4:Ce3+ matching well with near 400 nm chip and showing high thermal stability has been developed. The photoluminescence spectrum presents a broad emission band peaking at 460 nm with a bandwidth of nearly 90 nm. By optimizing the Ce3+ concentration, an internal quantum efficiency (IQE) as high as 76% was achieved. Furthermore, 86% of the room-temperature emission intensity is still maintained at 150 °C, indicating a good thermal stability and practicality. A series of white LEDs were fabricated based on 405 nm chips coated with a blend of the new blue phosphor with the commercial yellow and red phosphors. High color rendering indexes (≥90) were achieved while the correlated color temperature was tuneable in the range of 3094 to 8990 K. These results suggest that SrLu2O4:Ce3+ can be utilized as a blue-emitting phosphor in NUV based white LEDs.
Extracellular matrix scaffold and hydrogel derived from decellularized and delipidized human pancreas
Authors: Sackett Sara Dutton , Tremmel Daniel M. , Ma Fengfei , Feeney Austin K. , Maguire Rachel M. , Brown Matthew E. , Zhou Ying , Li Xiang , O’Brien Cori , Li Lingjun , Burlingham William J. , Odorico Jon S. 
Published: July 2018

AbstractExtracellular matrix (ECM) plays an important developmental role by regulating cell behaviour through structural and biochemical stimulation. Tissue-specific ECM, attained through decellularization, has been proposed in several strategies for tissue and organ replacement. Decellularization of animal pancreata has been reported, but the same methods applied to human pancreas are less effective due to higher lipid content. Moreover, ECM-derived hydrogels can be obtained from many decellularized tissues, but methods have not been reported to obtain human pancreas-derived hydrogel. Using novel decellularization methods with human pancreas we produced an acellular, 3D biological scaffold (hP-ECM) and hydrogel (hP-HG) amenable to tissue culture, transplantation and proteomic applications. The inclusion of a homogenization step in the decellularization protocol significantly improved lipid removal and gelation capability of the resulting ECM, which was capable of gelation at 37 °C in vitro and in vivo, and is cytocompatible with a variety of cell types and islet-like tissues in vitro. Overall, this study demonstrates the characterisation of a novel protocol for the decellularization and delipidization of human pancreatic tissue for the production of acellular ECM and ECM hydrogel suitable for cell culture and transplantation applications. We also report a list of 120 proteins present within the human pancreatic matrisome.
Hyperspectral near infrared imaging quantifies the heterogeneity of carbon materials
Authors: Mäkelä Mikko , Geladi Paul 
Published: July 2018

AbstractFor many applications heterogeneity is a direct indicator of material quality. Reliable determination of chemical heterogeneity is however not a trivial task. Spectral imaging can be used for determining the spatial distribution of an analyte in a sample, thus transforming each pixel of an image into a sampling cell. With a large amount of image pixels, the results can be evaluated using large population statistics. This enables robust determination of heterogeneity in biological samples. We show that hyperspectral imaging in the near infrared (NIR) region can be used to reliably determine the heterogeneity of renewable carbon materials, which are promising replacements for current fossil alternatives in energy and environmental applications. This method allows quantifying the variation in renewable carbon and other biological materials that absorb in the NIR region. Reliable determination of heterogeneity is also a valuable tool for a wide range of other chemical imaging applications.
Electrosensory capture during multisensory discrimination of nearby objects in the weakly electric fish Gnathonemus petersii
Authors: Schumacher Sarah , Burt de Perera Theresa , von der Emde Gerhard 
Published: July 2018

AbstractAnimal multisensory systems are able to cope with discrepancies in information provided by individual senses by integrating information using a weighted average of the sensory inputs. Such sensory weighting often leads to a dominance of a certain sense during particular tasks and conditions, also called sensory capture. Here we investigated the interaction of vision and active electrolocation during object discrimination in the weakly electric fishGnathonemus petersii.Fish were trained to discriminate between two objects using both senses and were subsequently tested using either only vision or only the active electric sense. We found that at short range the electric sense dominates over vision, leading to a decreased ability to discriminate between objects visually when vision and electrolocation provide conflicting information. In line with visual capture in humans, we call this dominance of the electric senseelectrosensory capture. Further, our results suggest that the fish are able to exploit the advantages of multiple senses using vision and electrolocation redundantly, synergistically and complementarily. Together our results show that by providing similar information about the environment on different spatial scales, vision and the electric sense ofG. petersiiare well attuned to each other producing a robust and flexible percept.
Investigation of dust attenuation and star formation activity in galaxies hosting GRBs
Authors: Corre D. , Buat V. , Basa S. , Boissier S. , Japelj J. , Palmerio J. , Salvaterra R. , Vergani S.D. , Zafar T. 
Published: July 2018

Context. The gamma-ray bursts hosts (GRBHs) are excellent targets to study the extinction properties of dust and its effects on the global emission of distant galaxies. The dust extinction curve is measured along the GRB afterglow line of sight and the analysis of the spectral energy distribution (SED) of the host galaxy gives access to the global dust attenuation of the stellar light.
Aims. In this pilot study we gather information on dust extinction in GRBHs to compare the properties of the extinction curve to those of the dust obscuration affecting the total stellar light of the host galaxy. Assuming the extinction curve to be representative of the dust properties, we aim to investigate which dust-stars geometries and local dust distribution in the inter stellar medium (ISM) can reproduce the observed attenuation curve.
Methods. We selected a sample of 30 GRBs for which the extinction curve along the GRB afterglow line-of-sight (l.o.s.) is measured in the rest-frame ultraviolet (UV) up to optical and we analysed the properties of the extinction curve as a function of the host galaxy properties. From these 30 GRBs, we selected seven GRBHs with a good rest-frame UV to near-infrared (NIR) spectral coverage for the host. The attenuation curve was derived by fitting the SEDs of the GRBH sample with the CIGALE SED fitting code. Different star formation histories (SFH) were studied to recover the star formation rates (SFR) derived using Hα luminosities. Implications for the dust-stars geometries in the ISM are inferred by a comparison with radiative transfer simulations.
Results. The most extinguished GRBs are preferentially found in the more massive hosts and the UV bump is preferentially found in the most extinguished GRB l.o.s. Five out of seven hosts are best fitted with a recent burst of star formation, leading to lower stellar mass estimates than previously found. The average attenuation in the host galaxies is about 70% of the amount of extinction along the GRB l.o.s. We find a great variety in the derived attenuation curves of GRBHs, the UV slope can be similar, flatter or even steeper than the extinction curve slope. Half of the attenuation curves are consistent with the Calzetti attenuation law and there is evidence of a UV bump in only one GRBH. We find that the flatter (steeper) attenuation curves are found in galaxies with the highest (lowest) SFR and stellar masses. The comparison of our results with radiative transfer simulations leads to a uniform distribution of dust and stars in a very clumpy ISM for half the GRBHs and various dust-stars geometries for the second half of the sample.
Asteroid models reconstructed from the Lowell Photometric Database and WISE data
Authors: Ďurech J. , Hanuš J. , Alí-Lagoa V. 
Published: July 2018

Context. Information about the spin state of asteroids is important for our understanding of the dynamical processes affecting them. However, spin properties of asteroids are known for only a small fraction of the whole population.Aims. To enlarge the sample of asteroids with a known rotation state and basic shape properties, we combined sparse-in-time photometry from the Lowell Observatory Database with flux measurements from NASA’s WISE satellite.Methods. We applied the light curve inversion method to the combined data. The thermal infrared data from WISE were treated as reflected light because the shapes of thermal and visual light curves are similar enough for our purposes. While sparse data cover a wide range of geometries over many years, WISE data typically cover an interval of tens of hours, which is comparable to the typical rotation period of asteroids. The search for best-fitting models was done in the framework of the Asteroids@home distributed computing project.Results. By processing the data for almost 75 000 asteroids, we derived unique shape models for about 900 of them. Some of them were already available in the DAMIT database and served us as a consistency check of our approach. In total, we derived new models for 662 asteroids, which significantly increased the total number of asteroids for which their rotation state and shape are known. For another 789 asteroids, we were able to determine their sidereal rotation period and estimate the ecliptic latitude of the spin axis direction. We studied the distribution of spins in the asteroid population. Apart from updating the statistics for the dependence of the distribution on asteroid size, we revealed a significant discrepancy between the number of prograde and retrograde rotators for asteroids smaller than about 10 km.Conclusions. Combining optical photometry with thermal infrared light curves is an efficient approach to obtaining new physical models of asteroids. The amount of asteroid photometry is continuously growing and joint inversion of data from different surveys could lead to thousands of new models in the near future.
Severe Vitamin D3 Deficiency in the Majority of Patients with Diabetic Foot Ulcers
Authors: Feldkamp Joachim , Jungheim Karsten , Schott Matthias , Jacobs Beatrix , Roden Michael 
Published: July 2018

AbstractDiabetic foot ulcers are a severe complication in patients with diabetes mellitus. Vitamin D is associated with impaired β-cell function and insulin resistance, and is necessary for wound healing and bone metabolism. We measured the serum concentrations of 25-hydroxyvitamin D3 in 104 patients (63 inpatients, 41 outpatients) with diabetic foot ulcers and compared them to 99 healthy humans (control) and 103 patients with diabetes mellitus type 2 without diabetic foot ulcers. Calcium, creatinine, and parathyroid hormone were measured in patients with diabetic foot ulcers. The data were analysed together with glycosylated hemoglobin A1c and the severity of diabetic foot lesions according to the Armstrong classification. Levels of 25-hydroxyvitamin D3 were lower (11.8±11.3 ng/ml, p<0.001) in patients with diabetic foot ulcers (mean age 70±12 years) than in the control group (27.2±12.2 ng/ml). No difference was found between in- and outpatients. Fifty-eight (55.8%) of patients with diabetic foot ulcers had a severe 25-hydroxyvitamin D3 deficiency with levels below 10 ng/ml. Only 12% of the patients had 25-hydroxyvitamin D3 levels above 20 ng/ml. Secondary hyperparathyroidism was found in 27.9% of patients and 11.5% of the patients were hypocalcemic. There was a negative correlation (r=–0.241) (p<00.1) between Armstrong classification and 25-hydroxyvitamin D3 status. In conclusion, patients with diabetic foot syndrome are at high risk of 25-hydroxyvitamin D3 deficiency. Thus, any patient with diabetic foot syndrome should undergo 25-hydroxyvitamin D3 measurement and supplementation, if values are found to be decreased.
A New Type of Congenital Dysfibrinogen, Fibrinogen Bremen, with an Aα Gly-17 to Val Substitution Associated with Hemorrhagic Diathesis and Delayed Wound Healing
Authors: Wada Yasuo , Niwa Kazuki , Meakawa Hisato , Asakura Shinji , Sugo Teruko , Nakanishi Makoto , Auerswald Günter , Popp Manfred , Matsuda Michio 
Published: July 2018

SummaryWe have identified a new type of Aα Gly-17 to Val substitution in a congenital dysfibrinogen, fibrinogen Bremen, derived from a 15-year-old boy having manifested easy bruising and delayed wound healing. The functional abnormality was characterized by altered fibrin monomer polymerization, which became evident by increasing the salt concentration and pH. A synthetic tetrapeptide with a sequence of the amino-terminal segment of normal fibrin α-chain, Gly-Pro-Arg-Val, substantially inhibited polymerization of both normal and the patient-derived fibrin monomers. A synthetic tetrapeptide with the Bremen type sequence of Val-Pro-Arg-Val inhibited polymerization of the patient’s fibrin monomers partially at a peptide: fibrin monomer molar ratio of 4,000:1, and that of normal one at a much higher ratio of 10,000:1. Likewise, a synthetic peptide Ala-Pro-Arg-Val with a replacement of the Gly residue by another aliphatic amino acid Ala inhibited similarly the patient’s fibrin monomer polymerization. Thus, the hypothetical two-pronged socket-like structure consisting of the α-amino group of the amino-terminal Gly and the guanidino group of an Arg at position 3 of the normal fibrin α-chain seems to be restored considerably in the mutant fibrin α-chain at low ionic strengths and pH’s, despite the replacement of the amino-terminal Gly by another aliphatic amino acid Val.