bluuebunny/crossref_metadata_2025 huggingface dataset:
E-Zigaretten: gesundheitliche Bewertung und potenzieller Nutzen für Raucher
Authors: Schaller K. , Mons U.
Published: June 2018

In E-Zigaretten wird eine aromatisierte Flüssigkeit erhitzt, und der Konsument inhaliert das dabei entstehende Aerosol. Die große Vielfalt der E-Zigaretten und Liquids erschwert die Abschätzung der gesundheitlichen Auswirkungen der verschiedenen Produkte. Die Inhaltsstoffe der Liquids sind – abgesehen von Nikotin – für die orale und dermale Aufnahme unbedenklich, zu den gesundheitlichen Auswirkungen chronischer Inhalation fehlen jedoch toxikologische Daten. Studien haben im E-Zigaretten-Aerosol verschiedene gesundheitsschädliche Substanzen nachgewiesen, darunter auch Kanzerogene, allerdings in niedrigerer Konzentration als in Tabakrauch. Die vorliegenden Studien deuten darauf hin, dass E-Zigaretten-Konsum zu kurzfristigen Gesundheitseffekten wie entzündlichen Reaktionen in der Lunge führt. In Tier- und Zellversuchen zeigte E-Zigaretten-Aerosol gesundheitsschädliche Effekte wie Zytotoxizität, verstärkte Infiltration von Entzündungszellen und entzündungsfördernden Zytokinen, erhöhten oxidativen Stress und moderate Entzündung.

Sehr wahrscheinlich ist der E-Zigaretten-Konsum im Vergleich zum Tabakrauchen weniger schädlich, aufgrund fehlender Studien zu langfristigen Gesundheitsgefahren kann das Ausmaß der Schadensminderung jedoch nicht quantifiziert werden. Zwar verwenden Raucher E-Zigaretten oftmals, um mit dem Rauchen aufzuhören, aber derzeit sind die Produkte nicht als Hilfsmittel zur Tabakentwöhnung zugelassen. Da E-Zigaretten-Aerosol eine neue Quelle für die Belastung der Raumluft ist, ist davon auszugehen, dass es für im Raum anwesende Nichtkonsumenten eine Gesundheitsgefährdung bedeutet, insbesondere für vulnerable Personengruppen wie Kinder oder Menschen mit Gesundheitsproblemen. Auf die öffentliche Gesundheit können sich E-Zigaretten positiv auswirken, wenn viele Raucher vollständig vom Tabakrauchen auf E-Zigaretten-Konsum umsteigen und langfristig auch diesen einstellen, und wenn gleichzeitig negative Effekte (wie steigender Konsum unter Jugendlichen) begrenzt bleiben.
Congruence method for global Darboux reduction of finite-dimensional Poisson systems
Authors: Hernández-Bermejo Benito
Published: June 2018

A new procedure for the global construction of the Casimir invariants and Darboux canonical form for finite-dimensional Poisson systems is developed. This approach is based on the concept of matrix congruence and can be applied without the previous determination of the Casimir invariants (recall that their prior knowledge is unavoidable for the standard reduction methods, thus requiring either the integration of a system of PDEs or solving some equivalent problem). Well the opposite, in the new congruence method, both the Darboux coordinates and the Casimir invariants arise simultaneously as the outcome of the reduction algorithm. In fact, the congruence algorithm proceeds only in terms of matrix-algebraic transformations and direct quadratures, thus avoiding the need of previously integrating a system of PDEs and therefore improving previously known approaches. Physical examples illustrating different aspects of the theory are provided.
Biomass and lipid production of a novel microalga, Chlorellaceae sp. P5, through heterotrophic and swine wastewater cultivation
Authors: Chiang Yin-Ling , Chen Yu-Pei , Yu Ming-Chen , Hsieh Sung-Yuan , Hwang Ing-Er , Liu Yi-Ju , Huang Cheng-Yu , Tseng Ching-Ping , Liaw Li-Ling
Published: June 2018

A potential novel genus of microalgae was isolated from swine wastewater. According to a phylogenetic analysis of 18S rRNA and internal transcribed spacer (ITS) sequences, as well as the ITS2 secondary structure, this strain was designated as Chlorellaceae sp. P5. Acclimatization to various temperatures, pH conditions, and salinities demonstrated that this strain can grow at temperatures of 20 °C–40 °C, in an acidity range of pH 4–7, and with salinity as high as 3% NaCl. To optimize biomass production, response surface methodology was used which included variables associated with carbon and nitrogen sources. In this study, flask cultivation yielded 1.66 g l−1 d−1 of biomass under 15.19 g l−1 glucose and 8.26 mM ammonium bicarbonate. The fatty acid composition suggested that the lipid from Chlorellaceae sp. P5 can be typically used for biodiesel production, with a low degree of unsaturated fatty acids. Moreover, a high content of the first-limiting amino acid (lysine) and 9,12-Octadecadienoic acid (linoleic acid, C18:2) for nutritional supplements was also observed. With respect to swine wastewater treatment, the isolated strain showed an excellent removal rate of ammonia and phosphate over 97.3 mg l−1 of NH3-N and 20.3 mg of l−1 PO43− in the sterilized and none-sterilized wastewater. The biomass and lipid derived from Chlorellaceae sp. P5 can be attained at 0.49 g l−1 d−1 and 0.13 g l−1 d−1 by swine wastewater cultivation with 5% CO2 supply, respectively. According to the various characteristic analyses, Chlorellaceae sp. P5 has great potential for different industrial developments such as biodiesel and wastewater treatment.
Ultrafast two-dimensional lithium beam emission spectroscopy diagnostic on the EAST tokamak
Authors: Zoletnik S. , Hu G. H. , Tál B. , Dunai D. , Anda G. , Asztalos O. , Pokol G. I. , Kálvin S. , Németh J. , Krizsanóczi T.
Published: June 2018

A diagnostic instrument is described for the Experimental Advanced Superconducting Tokamak (EAST) for the measurement of the edge plasma electron density profile and plasma turbulence properties. An accelerated neutral lithium beam is injected into the tokamak and the Doppler shifted 670.8 nm light emission of the Li2p-2s transition is detected. A novel compact setup is used, where the beam injection and observation take place from the same equatorial diagnostic port and radial-poloidal resolution is achieved with microsecond time resolution. The observation direction is optimized in order to achieve a sufficient Doppler shift of the beam light to be able to separate from the strong edge lithium line emission on this lithium coated device. A 250 kHz beam chopping technique is also demonstrated for the removal of background light. First results show the capability of measuring turbulence and its poloidal flow velocity in the scrape-off layer and edge region and the resolution of details of transient phenomena like edge localized modes with few microsecond time resolution.
Gap-junction coupling can prolong beta-cell burst period by an order of magnitude via phantom bursting
Authors: Loppini Alessandro , Pedersen Morten Gram
Published: June 2018

Pancreatic β-cells show multiple intrinsic modes of oscillation with bursting electrical activity playing a crucial role. Bursting is seen both in experimentally isolated β-cells as well as in electrically coupled cells in the pancreatic islets, but the burst period is typically an order of magnitude greater in coupled cells. This difference has previously been attributed to noisier dynamics, or perturbed electrophysiological properties, in isolated β-cells. Here, we show that diffusive coupling alone can extend the period more than ten-fold in bursting oscillators modeled with a so-called phantom burster model and analyze this result with slow-fast bifurcation analysis of an electrically coupled pair of cells. Our results should be applicable to other scenarios where coupling of bursting units, e.g., neurons, may increase the oscillation period drastically.
Enhanced laser proton acceleration by target ablation on a femtosecond laser system
Authors: Liao Q. , Wu M. J. , Gong Z. , Geng Y. X. , Xu X. H. , Li D. Y. , Shou Y. R. , Zhu J. G. , Li C. C. , Yang M. , Li T. S. , Lu H. Y. , Ma W. J. , Zhao Y. Y. , Lin C. , Yan X. Q.
Published: June 2018

Proton acceleration during the interaction of an ultraintense (6 × 1019 W/cm2) femtosecond (fs) laser pulse with a thin (2.5 μm) foil target pre-ablated by a picosecond (ps) pulse is experimentally and numerically investigated. Enhancements in both proton cut-off energy and charge are observed with the target ablation due to a large number of energetic electrons generated from the preformed preplasma in front of the target. The enhanced proton beams are successfully collected at 4–9 MeV with ±4% energy spread and then transported to the irradiating platform. The results show that for the interaction between fs laser pulse and μm-thickness target, proton energy and charge can be enhanced by target ablation using a ps laser pulse, which is valuable for application like cancer radiotherapy.
Analysis of adhesion kinetics of cancer cells on inflamed endothelium using a microfluidic platform
Authors: Thompson Taylor J. , Han Bumsoo
Published: June 2018

Metastasis is the ultimate cause of death among the vast majority of cancer patients. This process is comprised of multiple steps, including the migration of circulating cancer cells across microvasculature. This trans-endothelial migration involves the adhesion and eventual penetration of cancer cells to the vasculature of the target organ. Many of these mechanisms remain poorly understood due to poor control of pathophysiological conditions in tumor models. In this work, a microfluidic device was developed to support the culture and observation of engineered microvasculature with systematic control of the environmental characteristics. This device was then used to study the adhesion of circulating cancer cells to an endothelium under varying conditions to delineate the effects of hemodynamics and inflammations. The resulting understanding will help to establish a quantitative and biophysical mechanism of interactions between cancer cells and endothelium.
Folding free energy landscapes of β-sheets with non-polarizable and polarizable CHARMM force fields
Authors: Hazel Anthony J. , Walters Evan T. , Rowley Christopher N. , Gumbart James C.
Published: June 2018

Molecular dynamics (MD) simulations of peptides and proteins offer atomic-level detail into many biological processes, although the degree of insight depends on the accuracy of the force fields used to represent them. Protein folding is a key example in which the accurate reproduction of folded-state conformations of proteins and kinetics of the folding processes in simulation is a longstanding goal. Although there have been a number of recent successes, challenges remain in capturing the full complexity of folding for even secondary-structure elements. In the present work, we have used all-atom MD simulations to study the folding properties of one such element, the C-terminal β-hairpin of the B1 domain of streptococcal protein G (GB1). Using replica-exchange umbrella sampling simulations, we examined the folding free energy of two fixed-charge CHARMM force fields, CHARMM36 and CHARMM22*, as well as a polarizable force field, the CHARMM Drude-2013 model, which has previously been shown to improve the folding properties of α-helical peptides. The CHARMM22* and Drude-2013 models are in rough agreement with experimental studies of GB1 folding, while CHARMM36 overstabilizes the β-hairpin. Additional free-energy calculations show that small adjustments to the atomic polarizabilities in the Drude-2013 model can improve both the backbone solubility and folding properties of GB1 without significantly affecting the model’s ability to properly fold α-helices. We also identify a non-native salt bridge in the β-turn region that overstabilizes the β-hairpin in the C36 model. Finally, we demonstrate that tryptophan fluorescence is insufficient for capturing the full β-hairpin folding pathway.
On matching the anode ring with the magnetic field in an ATON-type Hall effect thruster
Authors: Liu Jinwen , Li Hong , Zhang Xu , Ding Yongjie , Wei Liqiu , Li Jianzhi , Yu Daren , Wang Xiaogang
Published: June 2018

In an ATON-type Hall effect thruster, a ring-shaped anode and a cusped magnetic field intersect the match between the anode shape and the field topology thus must be clarified to optimize the electron transport to the anode and consequently the design of a high-efficiency thruster. By changing the match pattern with both the change in the length of the anode ring and the axial displacement of the cusp magnetic field, this study experimentally investigated the influence of the match pattern on the discharge characteristics of an ATON-type thruster—P100—under the condition of a moderate discharge voltage. The experimental results show that there is a match pattern that always optimizes the performance of the P100 thruster. At the rated operation parameters (300 V of discharge voltage and 5 mg/s of propellant mass flow rate) and the rated magnetic field strength, the observed improvements on thrust (∼79 mN to ∼85 mN) and anode efficiency (∼46% to ∼55%) are significant. Through further theoretical analysis, this study revealed that the change in the characteristics of electron momentum and energy transfer in the near-anode region, induced by the change of the match pattern, is the basic reason. The findings of this work are instructive for both understanding the electron motion in a cusp magnetic field and guiding the design of the anode ring intersecting with a cusp magnetic field in an ATON-type Hall effect thruster.
Analysis of dependent scattering mechanism in hard-sphere Yukawa random media
Authors: Wang B. X. , Zhao C. Y.
Published: June 2018

The structural correlations in the microscopic structures of random media can induce the dependent scattering mechanism and thus influence the optical scattering properties. Based on our recent theory on the dependent scattering mechanism in random media composed of discrete dipolar scatterers [B. X. Wang and C. Y. Zhao, Phys. Rev. A 97, 023836 (2018)], in this paper, we study the hard-sphere Yukawa random media, in order to further elucidate the role of structural correlations in the dependent scattering mechanism and hence optical scattering properties. Here, we consider charged colloidal suspensions, whose effective pair interaction between colloids is described by a screened Coulomb (Yukawa) potential. By means of adding salt ions, the pair interaction between the charged particles can be flexibly tailored and therefore the structural correlations are modified. It is shown that this strategy can affect the optical properties significantly. For colloidal TiO2 suspensions, the modification of electric and magnetic dipole excitations induced by the structural correlations can substantially influence the optical scattering properties, in addition to the far-field interference effect described by the structure factor. However, this modification is only slightly altered by different salt concentrations and is mainly because of the packing-density-dependent screening effect. On the other hand, for low refractive index colloidal polystyrene suspensions, the dependent scattering mechanism mainly involves the far-field interference effect, and the effective exciting field amplitude for the electric dipole almost remains unchanged under different structural correlations. The present study has profound implications for understanding the role of structural correlations in the dependent scattering mechanism.
Letter: Symmetric instability drastically changes upon inclusion of the full Coriolis force
Authors: Zeitlin V.
Published: June 2018

It is shown that the classical symmetric instability drastically changes, if the usually neglected vertical component of the Coriolis force and the contribution of the vertical velocity into its horizontal components are taken into account. The influence of these “non-traditional” terms is different for flows with positive and negative horizontal relative vorticities. A critical value of the Richardson number appears in the second case, with the instability changing its character across it. Major differences appear between hydrostatic and non-hydrostatic versions of the instability. All these features are absent in the traditional approximation.
Properties of magnetized Coulomb crystals of ions with polarizable electron background
Authors: Kozhberov A. A.
Published: June 2018

We have studied phonon and thermodynamic properties of a body-centered cubic (bcc) Coulomb crystal of ions with weakly polarized electron background in a uniform magnetic field B. At B = 0, the difference between phonon moments calculated using the Thomas-Fermi (TF) and random phase approximations is always less than 1% and for description of phonon properties of a crystal, TF formalism was used. This formalism was successfully applied to investigate thermodynamic properties of magnetized Coulomb crystals. It was shown that the influence of the polarization of the electron background is significant only at κTFa>0.1 and T≪Tp(1+h2)−1/2, where κTF is the Thomas-Fermi wavenumber, a is the ion sphere radius, Tp≡ℏωp is the ion plasma temperature, h≡ωB/ωp, ωB is the ion cyclotron frequency, and ωp is the ion plasma frequency.
Electron collection and thermionic emission from a spherical dust grain in the space-charge limited regime
Authors: Autricque A. , Khrapak S. A. , Couëdel L. , Fedorczak N. , Arnas C. , Layet J.-M. , Grisolia C.
Published: June 2018

The collection and emission of electrons from a spherical body in the Space-Charge Limited (SCL) regime are investigated. When a Virtual Cathode (VC) in the potential profile around the body is present, the barrier in the effective potential energy of electrons is assumed to be located near the position of the minimum of the VC potential, for both collected and emitted electrons. This assumption is confirmed to be reasonable in the case of a double Yukawa potential profile and allows the SCL cross-section for electron collection and the emitted electron’s trapped-passing boundary to be written in a simple way. An expression for the collection current for Maxwellian electrons is derived and is shown to recover the classical Orbital Motion Limited (OML) theory when the VC vanishes. Using the same assumptions, an expression for the thermionic emission current in the SCL regime is also obtained and comparisons with the OML+ theory are made. Finally, an expression for the dust electric charge in the SCL regime is derived and shown to give drastically different results when compared to the commonly used formula (obtained from a Yukawa potential profile). Consequences in the framework of dust in tokamak plasmas are discussed.
Reduced electronic correlation effects in half substituted Ba(Fe1−xCox)2As2
Authors: Liu Z.-H. , Yaresko A. N. , Li Y. , Evtushinsky D. V. , Dai P.-C. , Borisenko S. V.
Published: June 2018

We report a comprehensive study of the tridimensional nature and orbital character of the low-energy electronic structure in 50% Cobalt doped Ba(Fe1−xCox)2As2 (d6.5), by using polarization- and photon energy-dependent angle-resolved photoemission spectroscopy. An extra electron-like Fermi surface is observed around the Brillouin zone boundary compared with isoelectronic KyFe2−xSe2 (d6.5). The bands near the Fermi level (EF) are mainly derived from Fe/Co 3d t2g orbitals, revealing visible dispersions along the kz direction. In combination with the local density approximation and the dynamical mean-field theory calculations, we find that the As 4p bands are non-renormalized and the whole 3d band needs to be renormalized by a “single” factor of ∼1.6, indicating moderate electronic correlation effects. The “single” factor description of the correlation strength among the different 3d orbitals is also in sharp contrast to orbital-dependent correlation effects in BaFe2As2. Our findings indicate a remarkable reduction of correlation effects with little difference among 3d orbitals in BaFeCoAs2, due to the increased filling of the electronic 3d shell in the presence of significant Hund's coupling. The results support that the electronic correlation effects and multiple orbital physics play an important role in the superconductivity of the 122 system and in other ferropnictides.
Communication: Correlation of terminal relaxation rate and viscosity enhancement in supramolecular small-molecule liquids
Authors: Bierwirth S. P. , Gainaru C. , Böhmer R.
Published: June 2018

Monohydroxy alcohols with a large supramolecular Debye-type dielectric process often exhibit a significant decoupling between the Debye mode and the structural relaxation. Using shear rheology, a technique that is sensitive to both processes as well, the current work reveals a widely applicable correlation in terms of the dynamical onset and the viscosity enhancement of the supramolecular shear mode with respect to the structural relaxation. Rheological data from an array of about 50 oligomers, associating polymers, (polymerized) ionic liquids, and aqueous solutions corroborate this correlation which thus appears to be generic to many classes of complex fluids.
Distribution of organic carbon: possible causes and impacts in the Pangani River Basin ecosystem, Tanzania
Authors: Selemani Juma R. , Zhang Jing , Wu Ying , Muzuka Alfred N. N. , Njau Karoli N. , Zhang Guosen , Mzuza Maureen K. , Maggid Arafa , Zhang Miao , Qi Lijun
Published: June 2018

Environmental contextUnderstanding the sources of organic carbon and its spatial and seasonal variation is essential for implementing measures to control water pollution. There is, however, only limited information about organic carbon in east African rivers. This study reports the distribution of dissolved and particulate organic carbon in the Pangani River Basin, using isotopes to trace sources of carbon to the basin and its flux to the Indian Ocean.
AbstractThere is limited information on organic carbon in African rivers, especially from the eastern side. Here, we report distribution and impacts of total suspended matter (TSM), and dissolved and particulate organic carbon (DOC & POC) in the Pangani River Basin (PRB) ecosystem together with their fluxes to the Indian Ocean. δ13C was also used to trace sources of carbon in the basin. Results showed that the basin is supplied with carbon from allochthonous sources dominated by C3 plants, with higher levels of TSM and DOC in the wet season than in the dry season. Several factors, including altitude, temperature, rainfall, lithology and anthropogenic activities, have a significant influence on the seasonal and spatial distribution of organic carbon in the basin. High discharge in the wet season mobilised terrestrial organic carbon to elevate concentrations of DOC, POC and TSM. Mean concentrations of DOC, dissolved inorganic carbon (DIC), POC and TSM in PRB were in ranges comparable to that in other tropical rivers but their fluxes were lower than in most tropical rivers around the world. Diverting water from the river for irrigation and hydroelectric power production was one of the factors that reduced the flux of carbon. Observed hypoxic conditions in the reservoir indicates that the quality of water for human and aquatic ecosystem health is possibly threatened by a high level of organic carbon; furthermore, the trends of increasing population, deforestation, temperature and rainfall will likely increase the concentration of organic carbon in the future. Better management of waste, afforestation and reforestation are recommended to restore degraded natural forest, so as to reduce uptake of organic carbon from the terrestrial environment.
Emerging opportunities for developing a diversified land sector economy in Australia’s northern savannas
Authors: Russell-Smith Jeremy , Sangha Kamaljit K.
Published: June 2018

We explore sustainable land sector opportunities for Australia’s 1.2 million km2 northern savanna rangelands where extensive beef cattle pastoralism is the predominant contemporary land use. Our focal region is characterised by mean annual rainfall exceeding 600 mm, ecologically bountiful wet season water availability followed by 6–8 months of surface water deficit, mostly nutrient-poor soils, internationally significant biodiversity and carbon stock values, very extensive dry season fires in pastorally unproductive settings, a sparse rural population (0.14 persons km–2) comprising a high proportion of Indigenous people, and associated limited infrastructure. Despite relatively high beef cattle prices in recent seasons and property values escalating at a spectacular ~6% p.a. over the past two decades, long-term economics data show that, for most northern regions, typical pastoral enterprises are unprofitable and carry significant debt. Pastoral activities can also incur very significant environmental impacts on soil and scarce dry season water resources, and greenhouse gas emissions, which currently are not accounted for in economic sustainability assessments. Over the same period, the conservation sector (including National Parks, Indigenous Protected Areas) has been expanding rapidly and now occupies 25% of the region. Since 2012, market-based savanna burning projects aimed at reducing greenhouse gas emissions occur over a further 25%. Returns from nature-based tourism focussed particularly on maintaining intact freshwater systems and associated recreational fishing opportunities dwarf returns from pastoralism. The growth of these latter industries illustrates the potential for further development of profitable ‘ecosystem services’ markets as part of a more environmentally and socially sustainable diversified regional land sector economy. We outline some of the imminent challenges involved with, and opportunities for developing, this new industry sector.
Origin of slow spontaneous resting-state neuronal fluctuations in brain networks
Authors: Krishnan Giri P. , González Oscar C. , Bazhenov Maxim
Published: June 2018

Significance

Resting-state infra-slow brain activity fluctuations are observed across various cognitive and disease brain states. Although resting-state fluctuations have received a great deal of interest over the past few years, the underlying biophysical mechanisms are not known. Using computational modeling, we show that spontaneous resting-state fluctuations arise from dynamic ion concentrations and are influenced by the Na
+
/K
+
pump, glial K
+
buffering, and AMPA/GABA synaptic currents. These findings provide insights into the biophysical mechanisms underlying generation of this phenomenon and may lead to better understanding of how different cognitive or disease states influence resting-state activity.
Structure–properties’ modification of 70/30 brass by large-load and low-speed friction stir processing
Authors: Xu Nan , Song Qining , Bao Yefeng
Published: June 2018

A novel one-step approach named large-load and low-speed friction stir processing was developed to produce an ultrafine-grain structure in 70/30 brass. The material so processed was characterised by a mean grain size of 0.5 µm and high angle boundaries of 91%. Abundant twin boundaries and stacking fault were produced in the grains as well. The grain refinement mechanism is attributed to the combination of discontinuous dynamic recrystallisation (DRX), microshear bands assisted DRX and twinning-induced DRX. A good combination of yield strength and uniform strain was achieved. This study provides a simple and effective method to improve the microstructure and mechanical properties in metals and alloys with low stacking fault energy.
PiggyBac-based screening identifiedBEM4as a suppressor to rescue growth defects in och1-disrupted yeast cells
Authors: Mutumwinka Diane , Zhao Shen-Bao , Liu Yi-Shi , Mensah Emmanuel Osei , Gao Xiao-Dong , Fujita Morihisa
Published: June 2018

Glycoengineered yeast cells, which express human-compatible glycan structures, are particularly attractive host cells to produce therapeutic glycoproteins. Disruption of OCH1 gene, which encodes an α-1,6-mannosyltransferase required for mannan-type N-glycan formation, is essential for the elimination of yeast-specific N-glycan structures. However, the gene disruption causes cell wall defects leading to growth defects. Here, we tried to identify factors to rescue the growth defects of och1Δ cells by in vivo mutagenesis using piggyBac (PB)-based transposon. We isolated a mutant strain, named 121, which could grow faster than parental och1Δ cells. The PB element was introduced into the promoter region of BEM4 gene and upregulated the BEM4 expression. Overexpression of BEM4 suppressed growth defects in och1Δ cells. The slow grow phenotypes were partially rescued by expression of Rho1p, whose function is regulated by Bem4p. Our results indicate that BEM4 would be useful to produce therapeutic proteins in glycoengineered yeast without the growth defects.
Extracellular vesicles direct migration by synthesizing and releasing chemotactic signals
Authors: Kriebel Paul W. , Majumdar Ritankar , Jenkins Lisa M. , Senoo Hiroshi , Wang Weiye , Ammu Sonia , Chen Song , Narayan Kedar , Iijima Miho , Parent Carole A.
Published: June 2018

Chemotactic signals are relayed to neighboring cells through the secretion of additional chemoattractants. We previously showed in Dictyostelium discoideum that the adenylyl cyclase A, which synthesizes the chemoattractant cyclic adenosine monophosphate (cAMP), is present in the intraluminal vesicles of multivesicular bodies (MVBs) that coalesce at the back of cells. Using ultrastructural reconstructions, we now show that ACA-containing MVBs release their contents to attract neighboring cells. We show that the released vesicles are capable of directing migration and streaming and are central to chemotactic signal relay. We demonstrate that the released vesicles not only contain cAMP but also can actively synthesize and release cAMP to promote chemotaxis. Through proteomic, pharmacological, and genetic approaches, we determined that the vesicular cAMP is released via the ABCC8 transporter. Together, our findings show that extracellular vesicles released by D. discoideum cells are functional entities that mediate signal relay during chemotaxis and streaming.
What Is Successful Aging? A Psychometric Validation Study of Different Construct Definitions
Authors: Kleineidam Luca , Thoma Myriam V , Maercker Andreas , Bickel Horst , Mösch Edelgard , Hajek André , König Hans-Helmut , Eisele Marion , Mallon Tina , Luck Tobias , Röhr Susanne , Weyerer Siegfried , Werle Jochen , Pentzek Michael , Fuchs Angela , Wiese Birgitt , Mamone Silke , Scherer Martin , Maier Wolfgang , Riedel-Heller Steffi G , Wagner, Michael
Published: June 2018

Background and Objectives

We examined the validity of 5 successful aging (SA) operationalizations that assessed different facets of the SA construct (cognitive and physical health and disability; well-being; social engagement).

Research Design and Methods

A total of 2,478 participants (mean age = 82.5 years, standard deviation [SD] = 3.47) were studied. We used confirmatory factor analysis to investigate the relationships between facets and to determine the convergent validity as well as short-term (1.5 years) and long-term (4.5 years) predictive validity of the 5 SA operationalizations for measures of quality of life (QoL) and objective health outcomes.

Results

A general SA operationalization that included all SA facets but also allowed differences between them showed the best model fit and construct validity. A biomedical operationalization of SA that excluded either the well-being or the social engagement facet showed lower convergent and predictive validity for subjective measures (e.g., QoL) but higher associations with objective measures (e.g., health). A purely psychosocial SA operationalization that excluded the physiological facet did not allow good prediction of objective health outcomes.

Discussion and Implications

Our results suggest that a well-balanced SA operationalization should include measures assessing health, disability, well-being, and social engagement.
AMBER: Assessment of Metagenome BinnERs
Authors: Meyer Fernando , Hofmann Peter , Belmann Peter , Garrido-Oter Ruben , Fritz Adrian , Sczyrba Alexander , McHardy Alice C
Published: June 2018

Reconstructing the genomes of microbial community members is key to the interpretation of shotgun metagenome samples. Genome binning programs deconvolute reads or assembled contigs of such samples into individual bins. However, assessing their quality is difficult due to the lack of evaluation software and standardized metrics. Here, we present Assessment of Metagenome BinnERs (AMBER), an evaluation package for the comparative assessment of genome reconstructions from metagenome benchmark datasets. It calculates the performance metrics and comparative visualizations used in the first benchmarking challenge of the initiative for the Critical Assessment of Metagenome Interpretation (CAMI). As an application, we show the outputs of AMBER for 11 binning programs on two CAMI benchmark datasets. AMBER is implemented in Python and available under the Apache 2.0 license on GitHub.
Semibricks
Authors: Asai Sota
Published: June 2018

In representation theory of finite-dimensional algebras, (semi)bricks are a generalization of (semi)simple modules, and they have long been studied. The aim of this paper is to study semibricks from the point of view of $\tau $-tilting theory. We construct canonical bijections between the set of support $\tau $-tilting modules, the set of semibricks satisfying a certain finiteness condition, and the set of 2-term simple-minded collections. In particular, we unify Koenig–Yang bijections and Ingalls–Thomas bijections generalized by Marks–Št’ovíček, which involve several important notions in the derived categories and the module categories. We also investigate connections between our results and two kinds of reduction theorems of $\tau $-rigid modules by Jasso and Eisele–Janssens–Raedschelders. Moreover, we study semibricks over Nakayama algebras and tilted algebras in detail as examples.
Interrogating the ‘Dignity’ Argument for Mandatory Retirement: An Undignified Development?
Authors: Blackham Alysia
Published: June 2018

Human dignity is often cited as a justification and foundation for equality law. However, it is also used in some contexts to justify detracting from equal treatment, including in relation to mandatory retirement ages in the UK. Drawing on interdisciplinary scholarship from legal theory and industrial relations, this article argues case law on retirement ages adopts a limited approach to the notion of ‘dignity’, which is grounded in age stereotypes. It considers how a re-conceptualisation of ‘dignity’ might inform the future development of the law on retirement ages and proposes alternative ways to secure individual dignity in employment that do not depend on mandatory retirement ages.
T-Cell Receptor Diversity and the Control of T-Cell Homeostasis Mark Ebola Virus Disease Survival in Humans
Authors: Speranza Emily , Ruibal Paula , Port Julia R , Feng Feng , Burkhardt Lia , Grundhoff Adam , Günther Stephan , Oestereich Lisa , Hiscox Julian A , Connor John H , Muñoz-Fontela César
Published: June 2018

Differences in T-cell phenotype, particularly the expression of markers of T-cell homeostasis, have been observed in fatal and nonfatal Ebola virus disease (EVD). However, the relationship between these markers with T-cell function and virus clearance during EVD is poorly understood. To gain biological insight into the role of T cells during EVD, combined transcriptomics and T-cell receptor sequencing was used to profile blood samples from fatal and nonfatal EVD patients from the recent West African EVD epidemic. Fatal EVD was characterized by strong T-cell activation and increased abundance of T-cell inhibitory molecules. However, the early T-cell response was oligoclonal and did not result in viral clearance. In contrast, survivors mounted highly diverse T-cell responses, maintained low levels of T-cell inhibitors, and cleared Ebola virus. Our findings highlight the importance of T-cell immunity in surviving EVD and strengthen the foundation for further research on targeting of the dendritic cell-T cell interface for postexposure immunotherapy.
Middle Fossa Approach for Resection of Vestibular Schwannomas: A Decade of Experience
Authors: Kosty Jennifer A , Stevens Shawn M , Gozal Yair M , DiNapoli Vincent A , Patel Smruti K , Golub Justin S , Andaluz Norberto O , Pensak Myles , Zuccarello Mario , Samy Ravi N
Published: June 2018

BACKGROUND

The middle cranial fossa (MCF) approach is a challenging surgical technique for the resection of small and intermediate sized, primarily intracanalicular, vestibular schwannomas (VS), with the goal of hearing preservation (HP).

OBJECTIVE

To describe a decade-long, single institutional experience with the MCF approach for resection of VS.

METHODS

This is a retrospective cohort study of 63 patients who underwent the MCF approach for resection of VS from 2006 to 2016. Audiometric data included pure-tone average (PTA), low-tone pure-tone average (LtPTA), word recognition score, and American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) hearing classification at presentation and follow-up. Patients with postoperative serviceable (AAO-HNS class A-B) and/or useful (AAO-HNS class A-C) hearing were compared to those without HP. Facial nerve function was assessed using the House–Brackmann scale.

RESULTS

The mean age and duration of follow-up were 50 ± 13 yr and 21 ± 21 mo, respectively. The mean tumor size was 10 ± 4 mm. The serviceable and usable HP rates were 54% and 50%, respectively. Some residual hearing was preserved in 71% of patients. Large tumor size (P = .05), volume (P = .03), and extrameatal tumor extension (P = .03) were associated with poor audiometric outcomes. The presence of a fundal fluid cap (P = .01) was a favorable finding. At definitive testing, LtPTA was significantly better preserved than traditional PTA (P = .01). Facial nerve outcomes, tumor control rates, and durability of audiometric outcomes were excellent. 47% of patients pursued aural rehabilitation.

CONCLUSION

In our series, the MCF approach for VS provided excellent rates of tumor and facial nerve function, with durable serviceable HP.
Hybrid Therapy for Metastatic Epidural Spinal Cord Compression: Technique for Separation Surgery and Spine Radiosurgery
Authors: Barzilai Ori , Laufer Ilya , Robin Adam , Xu Ran , Yamada Yoshiya , Bilsky Mark H
Published: June 2018

BACKGROUND

Despite major advances in radiation and systemic treatments, surgery remains a critical step in the multidisciplinary treatment of metastatic spinal cord tumors.

OBJECTIVE

To describe the indications, rationale, and technique of “hybrid therapy” (separation surgery and concomitant spine stereotactic radiosurgery [SRS]) along with practical nuances.

METHODS

Separation surgery describes a posterolateral approach for circumferential epidural decompression and stabilization. The goal is to decompress the spinal cord, stabilize the spine, and create adequate separation between the neural elements and the tumor for SRS to achieve durable tumor control.

RESULTS

A transpedicular route to achieve ventrolateral access and limited resection of the tumorous vertebral body is carried out. In the setting of high-grade cord compression, caution must be taken when performing the tumor decompression. “Separation” of the ventral epidural tumor component anteriorly creates space for concomitant SRS while a simple laminectomy would not adequately achieve this goal. Dissection of the posterior longitudinal ligament allows maximal ventral decompression. Gross total tumor resection is not crucial for durable tumor control using the “hybrid therapy” model. Thus, attempts at ventral tumor resection may unnecessarily increase operative morbidity. Cement augmentation of the construct or vertebral body may improve construct stability. CT myelogram is the preferred exam for postoperative SRS planning. Radiosurgical planning constitutes a multidisciplinary effort and guidelines for contouring in the postoperative setting have recently become available.

CONCLUSION

Separation surgery is an effective, well-tolerated, and reproducible surgery. It provides safe margins for concomitant SRS. Combined, this “Hybrid Therapy” allows durable local control, maintenance of spinal stability, and palliation of symptoms, while minimizing operative morbidity.
MAXI upper limits of the electromagnetic counterpart of GW170817
Authors: Sugita Satoshi , Kawai Nobuyuki , Nakahira Satoshi , Negoro Hitoshi , Serino Motoko , Mihara Tatehiro , Yamaoka Kazutaka , Nakajima Motoki
Published: June 2018

We report on the Monitor of All-sky X-ray Image (MAXI) observation of the gravitational-wave (GW) event GW170817 and the electromagnetic counterpart of GW170817. GW170817 is a binary neutron star coalescence candidate detected by the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) and Advanced Virgo detectors, and it is the first event for which the optical counterpart has been discovered. In the MAXI observation, the Gas Slit Camera (GSC) covered approximately 62% of the sky region of the GW event within the 90% probability during the first 92 min orbital period after the trigger. No significant X-ray transient was detected in the error region, and the upper limit of the average flux with a significance of 3σ in the 2–10 keV band was 53/26 mCrab (one-orbit observation/one-day observation). In the optical counterpart of GW170817, the observational window of the GSC at the position started 20 s after the GW trigger, but the high-voltage power supply of the GSC was unfortunately off at the time because the International Space Station (ISS) was entering a high-particle-background region.The first observation of the position by the GSC was eventually performed 16797 s (4.6 hr) after the GW trigger, yielding the 3σ upper limit of 8.60 × 10−9 erg cm−2 s−1 in the 2–10 keV band, though it was the earliest X-ray observation of the counterpart.
Obesity treatment by epigallocatechin‐3‐gallate−regulated bile acid signaling and its enriched Akkermansia muciniphila
Authors: Sheng Lili , Jena Prasant Kumar , Liu Hui‐Xin , Hu Ying , Nagar Nidhi , Bronner Denise N. , Settles Matthew L. , Baümler Andreas J. , Wan Yu‐Jui Yvonne
Published: June 2018

Dysregulated bile acid (BA) synthesis is accompanied by dysbiosis, leading to compromised metabolism. This study analyzes the effect of epigallocatechin‐3‐gallate (EGCG) on diet‐induced obesity through regulation of BA signaling and gut microbiota. The data revealed that EGCG effectively reduced diet‐increased obesity, visceral fat, and insulin resistance. Gene profiling data showed that EGCG had a significant impact on regulating genes implicated in fatty acid uptake, adipogenesis, and metabolism in the adipose tissue. In addition, metabolomics analysis revealed that EGCG altered the lipid and sugar metabolic pathways. In the intestine, EGCG reduced the FXR agonist chenodeoxycholic acid, as well as the FXR‐regulated pathway, suggesting intestinal FXR deactivation. However, in the liver, EGCG increased the concentration of FXR and TGR‐5 agonists and their regulated signaling. Furthermore, our data suggested that EGCG activated Takeda G protein receptor (TGR)‐5 based on increased GLP‐1 release and elevated serum PYY level. EGCG and antibiotics had distinct antibacterial effects. They also differentially altered body weight and BA composition. EGCG, but not antibiotics, increased Verrucomicrobiaceae, under which EGCG promoted intestinal bloom of Akkermansia muciniphila. Excitingly, A. muciniphila was as effective as EGCG in treating diet‐induced obesity. Together, EGCG shifts gut microbiota and regulates BA signaling thereby having a metabolic beneficial effect.—Sheng, L., Jena, P. K., Liu, H.‐X., Hu, Y., Nagar, N., Bronner, D. N., Settles, M. L., Baumler, A. J., Wan, Y.‐J. Y. Obesity treatment by epigallocatechin‐3‐gallate−regulated bile acid signaling and its enriched Akkermansia muciniphila. FASEB J. 32, 6371–6384 (2018). www.fasebj.org
Treatment of Nonhealing Ulcers with an Allograft/Xenograft Substitute: A Case Series
Authors: Sivlér Tobias , Sivlér Petter , Skog Mårten , Conti Luca , Aili Daniel
Published: June 2018

OBJECTIVE:

Wound dressings that use biosynthetic cellulose may be a good alternative to dressings currently used to treat chronic and acute ulcers because their nanostructure is similar to collagen. The objective of this study was to evaluate a wound dressing created with a new material that is composed of a fibrillary network of biosynthetic cellulose.

METHODS:

A case series of 8 patients in primary healthcare centers in Östergötland county council, Sweden, with chronic and acute lower limb wounds were treated with a wound dressing based on eiratex (S2Medical AB, Linköping, Sweden). The dressing was applied to traumatic (n = 5) and venous ulcers (n = 3). All ulcers were considered healed at the end of the treatment.

MAIN OUTCOME MEASURE:

The wounds were examined at regular intervals by a physician to determine healing time, number of dressing changes, and number of visits.

MAIN RESULTS:

Mean healing time was 43 ± 6 days after the first application of the dressing. The mean number of visits was 5.7 ± 0.6, and the mean number of dressings used per patient was 1.7 ± 0.2.

CONCLUSIONS:

These results demonstrate the efficacy of a wound dressing made of eiratex to heal chronic and acute ulcers. The data show that the number of dressings used and dressing changes needed to heal the ulcers are lower than what have been reported in the literature for other dressing materials.
Mixed-methods development of a new patient-reported outcome instrument for chronic low back pain: part 2—The Patient Assessment for Low Back Pain–Impacts (PAL-I)
Authors: Bushnell Donald M. , Blum Steven I. , Liedgens Hiltrud , Martin Mona L. , Freynhagen Rainer , Wallace Mark , Argoff Charles , Eerdekens Mariёlle , Kok Maurits , Patrick Donald L.
Published: June 2018

We describe qualitative and quantitative development and preliminary validation of the Patient Assessment for Low Back Pain–Impacts (PAL-I), a patient-reported outcome measure for use in chronic low back pain (cLBP) clinical trials. Concept elicitation and cognitive interviews (qualitative methods) were used to identify and refine symptom concepts. Classical test theory and Rasch measurement theory (quantitative methods) were used to evaluate item-level and scale-level performance of the PAL-I using an iterative approach between qualitative and quantitative methods. Patients with cLBP participated in concept elicitation interviews (N = 43), cognitive interviews (N = 38), and assessment of paper-to-electronic format equivalence (N = 8). A web-based sample of self-reported patients with cLBP participated in quantitative studies to evaluate preliminary (N = 598) and revised (n = 401) drafts and patients with physician-diagnosed cLBP (N = 45) participated in preliminary validation of the PAL-I. The instrument contained 9 items describing cLBP impacts (walking, sitting, standing, lifting, sleep, social activities, travelling, climbing, and body movements). Item-level performance, scale structure, and scoring seemed to be appropriate. One-week test–retest reproducibility was acceptable (intraclass correlation coefficient 0.88 [95% confidence interval, 0.78-0.94]). Convergent validity was demonstrated with PAL-I total score and Roland-Morris Disability Questionnaire (Pearson correlation 0.82), MOS-36 Physical Functioning (−0.71), and MOS-36 Bodily Pain (−0.71). Individual item scores and total score discriminated between numeric rating scale tertile groups and painDETECT categories. Interpretation of paper and electronic administration modes was equivalent. The PAL-I demonstrated content validity and is potentially useful to assess treatment benefit in clinical trials of cLBP therapies.