bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of novel pathogenic ABCA4 variants in a Han Chinese family with Stargardt disease
Authors: Xiang Qin , Cao Yanna , Xu Hongbo , Guo Yi , Yang Zhijian , Xu Lu , Yuan Lamei , Deng Hao
Published: December 2018

Stargardt disease (STGD1, OMIM 248200) is a common hereditary juvenile or early adult onset macular degeneration. It ultimately leads to progressive central vision loss. Here, we sought to identify gene mutations associated with STGD1 in a three-generation Han Chinese pedigree by whole exome sequencing and Sanger sequencing. Two novel potentially pathogenic variants in a compound heterozygous state, c.3607G>T (p.(Gly1203Trp)) and c.6722T>C (p.(Leu2241Pro)), in the ATP binding cassette subfamily A member 4 gene (ABCA4) were identified as contributing to the family’s STGD1 phenotype. These variants may impact the ABCA4 protein structure and reduce the retinal-activated ATPase activity, leading to abnormal all-trans retinal accumulation in photoreceptor outer segments and in retinal pigment epithelium cells. The present study broadens the mutational spectrum of the ABCA4 responsible for STGD1. A combination of whole exome sequencing and Sanger sequencing is likely to be a time-saving and cost-efficient approach to screen pathogenic variants in genetic disorders caused by sizable genes, as well as avoiding misdiagnosis. These results perhaps refine genetic counseling and ABCA4-targetted treatments for families affected by STGD1.
Theory and experiment on horizontally inhomogeneous rectangular microstrip antenna
Authors: Maity Sudipta , Gangopadhyaya Malay , Gupta Bhaskar
Published: December 2018

Theoretical investigation on horizontally inhomogeneous rectangular microstrip antenna is presented here. The dielectric inhomogeneity is introduced by adding two different substrate materials side by side to increase the degrees of freedom by 2 (arm ratio and relative permittivity of newly added material). and both modes are used here for theoretical investigations. The transcendental equation is derived here to predict the resonant frequency for different modes. Closed‐form analytical expressions are also given to predict the far‐zone electric fields for different modes. Theoretical results are compared with published results as found in the open literature, data obtained using commercially available numerical three‐dimensional electromagnetic simulator high‐frequency structure simulator, and the authors’ own experimental data to show the accuracy of their theory. The additional horizontal dielectric segment gives more flexibility to the antenna designer, leading to wider tuning range over conventional homogeneous RMA. Advantages of this novel antenna structure are also discussed in detail. The authors’ theory can be used (or extended) to investigate log‐periodic antenna using RMAs, fractal‐shaped RMAs etc.
Monitoring of contact state of GIS switch based on infrared sensing technology
Authors: Chen Chen , Zhang Lei , Wang Liqiang , Liu Qi , Shan Tao , Wei Wei
Published: December 2018

The GIS is widely used in the power system. However, the overheating of the device contacts may cause serious accidents. A method of online monitoring of contact temperature of GIS equipment is put forward based on infrared sensing technology in view of the structural characteristics of GIS device. The method realises continuous and automatic measurement of temperature. The selection and installation location of temperature sensor are analysed, and here, the characteristics of GIS contact temperature measurement are studied. The GIS temperature measurement system is set up on the basis of previous research. The system is used to carry out experiments, whether the shielding cover of the device contact is existing in the process of temperature measurement is studied, respectively. The artificial neural network algorithm is used to process the data. The experimental results verify the feasibility and stability of the GIS contact temperature‐monitoring system. The potential economic benefit of this study is huge and its application prospect is very broad.
Modular multilevel converter composite submodule topology and control
Authors: Zhang Jianpo , Jiang Chang , Han Yanan
Published: December 2018

The DC‐side short‐circuit fault suppression of modular multilevel converter (MMC) applied to DC transmission has been a technical problem. According to the different location of cutting off fault current, this study first analyses three possible suppression schemes: AC/DC circuit breaker, bridge arm damper, and MMC submodule (SM) topologies and their respective features. Then, characteristics of SM topologies with DC fault current self‐blocking capability are summarised, and an improved composite SM topology is designed based on the full‐bridge SM and multilevel capacitor storage structures. The suppression characteristics of the proposed topology under different operation modes, capacitor voltage balancing control during blocking, and self‐starting process are also studied. Finally, a simulation model is built in the PSCAD/EMTDC to verify the DC‐side short‐circuit fault suppression characteristics and control strategies.
Optimisation of commutation circuit parameters for DC vacuum circuit breakers
Authors: Yu Deen , Chen Hai , Liu Wei , Liu Xiaoming
Published: December 2018

As the environmental problems caused by the consumption of the non‐renewable fossil energy are getting increasingly serious, the new energy power generation has received wide attentions. Multi‐terminal high voltage DC (HVDC) transmission is one of the key technologies for improving the reliability and stability of new energy power generations. Besides, HVDC circuit breakers (CBs) become the bottleneck of the development and application for multi‐terminal HVDC transmission power systems. Here, the active DC vacuum circuit breaker (VCB) is taken as the research object. Meanwhile, the optimisation design of the commutation circuit for the DC VCB is realised. According to Kirchhoff's law, the genetic algorithm is used to calculate the commutation parameters under different optimisation objectives, to obtain the lowest cost and the shortest sheath development time. Based on the software package MATLAB, the simulations and analyses of different optimisation objectives and parameters are carried out. Through the comparative analyses of the two optimisation objectives, the relationships between the development time of the sheath gap and the cost have been obtained.
Architecture of urban rail transit power supply based on PET braking energy feedback
Authors: Liu Hao , Zheng Zedong , Xu Zheng
Published: December 2018

In recent years, the urban rail transit has a great development in many cities of China. It is important to keep the DC transit grid strong and the power transmitted/power transmission high quality. During the process of rail operation, braking energy leads to a wide range of load oscillation for the traction and city grid, which cannot be absorbed inside the rail transit system. In this study, a novel architecture of urban rail transit power supply based on power electronics transformer braking energy feedback is put forward. Based on the circle grid, the topology adds an inverter to LLC series resonant converter to carry the power from 1500 V DC traction grid to 1180 V AC. Analysis together with simulation on the topology and control strategy is made on the basis of MATLAB/Simulink. Process of braking energy feedback and transmission of energy are illustrated with simulation. By paralleling the three‐phase H bridge and braking energy feedback device, double direction of the power flow is ensured. As a consequence, the power quality increases and harmonics reduce. The energy can be used more efficiently to achieve better effects on energy conservation.
Research on optimisation of minimum air clearance of 1000 kV UHV AC substation
Authors: Zhenqiang Li , Liang Xie , Jing Liu , Huiwen He
Published: December 2018

Based on air clearance discharge characteristic curve and insulation coordination method, it is pointed out that the minimum air clearance of 1000 kV ultra‐high voltage (UHV) AC substation can be further optimised. On the basis of analysis of the merits and demerits of the two insulation coordination methods for air clearances of UHV substation stated in the national standard GB/Z 24842–2009, it is concluded that using statistical method for insulation coordination is more reasonable and feasible. The minimum air clearance of UHV substation is optimised with the statistical method based on 1000 μs switching impulse characteristic test results. According to the study results, the phase‐to‐earth air clearance A1′ can be 1 m less than that specified in standard, the air clearance between conductors 0.5 m less than that specified in standard, and the phase‐to‐phase air clearance of grading ring and tubular bus 0.6 and 1.8 m, respectively, less than that specified in standard.
No unique solution to the seismological problem of standing kink magnetohydrodynamic waves
Authors: Arregui I. , Goossens M.
Published: December 2018

The aim of this paper is to point out that the classic seismological problem using observations and theoretical expressions for the periods and damping times of transverse standing magnetohydrodynamic waves in coronal loops is better referred to as a reduced seismological problem. “Reduced” emphasises the fact that only a small number of characteristic quantities of the equilibrium profiles can be determined. Reduced also implies that there is no unique solution to the full seismological problem. Even the reduced seismological problem does not allow a unique solution. Bayesian inference results support our mathematical arguments and offer insight into the relationship between the algebraic and the probabilistic inversions.
Junction conditions for finite horizon optimal control problems on multi-domains with continuous and discontinuous solutions
Authors: Ghilli Daria , Rao Zhiping , Zidani Hasnaa
Published: December 2018

This paper deals with junction conditions for Hamilton–Jacobi–Bellman (HJB) equations for finite horizon control problems on multi-domains. We consider two different cases where the final cost is continuous or lower semi-continuous. In the continuous case, we extend the results in Z. Rao and H. Zidani, Hamilton-Jacobi-Bellman equations on multi-domains, in Control and Optimization with PDE Constraints, Vol. 164 of International Series of Numerical Mathematics. Birkhäuser, Basel (2013) 93–116. in a more general framework with switching running costs and weaker controllability assumptions. The comparison principle has been established to guarantee the uniqueness and the stability results for the HJB system on such multi-domains. In the lower semi-continuous case, we characterize the value function as the unique lower semi-continuous viscosity solution of the HJB system, under a local controllability assumption.
Effect of hot rolling on the corrosion behavior of AZ31 magnesium alloy
Authors: Hanna Abdelkader , Dakhouche Achour , Tirsatine Kamel , Sari Ali , Khereddine Yazid , Bradai Djamel , Azzeddine Hiba
Published: December 2018

The aim of the present study is to investigate the effect of deformation conditions on the corrosion behavior of AZ31 (Mg-3Al-1Zn, % wt.) in 0.9% NaCl (wt.%) solution. The AZ31 alloy was hot rolled at 360 °C to 20 and 50% of thickness reduction. Electrochemical measurements were used to study the corrosion behavior of AZ31 alloy. Analysis of corrosion products after immersion test was performed using optical microscopy, X-ray diffraction and Raman spectroscopy. The mechanical properties of corroded samples were investigated using tensile test at room temperature. Results indicated that the corrosion rate was strongly affected by the hot rolling level. A lower corrosion potential and reduced polarization resistance was observed after hot rolling compared to the as received AZ31 alloy. The corrosion product was evidenced mainly as Mg(OH)2 compound exhibiting a filiform-like morphology. Apparently, the corrosion improved the room temperature ductility of AZ31 alloy.
Characterization and boriding kinetics of AISI T1 steel
Authors: Ortiz-Domínguez Martin , Keddam Mourad , Elias-Espinosa Milton , Ramírez-Cardona Marius , Arenas-Flores Alberto , Zuno-Silva Jorge , Cervantes-Sodi Felipe , Cardoso-Legorreta Edgar
Published: December 2018

The AISI T1 steel was hardened by the solid boriding process in the temperature range 1123–1273 K for a time duration of 2 to 8 h. A kinetic model, based on the integral method, was applied to the growth of a single boride layer (Fe2B) at the surface of AISI T1 steel. This diffusion model has been validated experimentally by considering two additional boriding conditions. A numerical solution was then obtained after solving the set of differential algebraic equations in order to compare the experimental thicknesses of Fe2B layers with the predicted values. The activation energy for boron diffusion in AISI T1 steel was estimated as 212.76 kJ mol−1and a comparison was made with other values available in the literature. The formed boride layers with a saw-tooth morphology were examined by scanning electron microscopy (SEM). X-ray diffraction confirmed that the borided layer was composed of only Fe2B. The Daimler-Benz Rockwell-C indentation technique was employed to assess the cohesion of Fe2B layers on AISI T1 steel. In addition, the pin-on-disc and wear scratch tests were carried out for investigating the wear behaviour of borided AISI T1 steel.
Vor 50 Jahren: Erste erfolgreiche Behandlung einer akuten Herztransplantat-Abstoßungskrise
Authors: Land Walter
Published: December 2018

The first clinical use of the “Munich antilymphocyte globulin” (ALG) at the occasion of the first successful human heart transplantation is briefly described. The cardiac transplantation was carried out by Christiaan Barnard and his team in Cape Town, South Africa, in 1968. The patient developed an acute allograft rejection which could be successfully reversed within three weeks using the intravenous administration of ALG. This event can be regarded as the beginning of a success story of ALG in its use as a powerful immunosuppressive agent in all categories of clinical organ transplantation.
Vom Chirurgen zum Verleger – Das Jahrhundertleben des Gottfried Bermann Fischer (1897–1995)
Authors: Bruns Florian
Published: December 2018

Gottfried Bermann Fischer was a German-Jewish physician and publisher who dedicated his life to the S. Fischer publishing company which ranks among the most significant German-language publishers in the 20th century. In 1925 Bermann left his position as a surgeon and married Brigitte Fischer, daughter of the company’s founder Samuel Fischer. Now called Bermann Fischer he became a passionate publisher and steered the company through the Weimar Republic and Nazi years, publishing authors like Hermann Hesse, Thomas Mann, and Alfred Döblin. Fearing the Nazi terror Bermann-Fischer left Germany in 1936 with his family and parts of the company. From his exile in Austria, Sweden, and later in the United States Bermann Fischer carried on with publishing. In 1950 the S. Fischer publishing company was reestablished in Frankfurt, West Germany. Bermann Fischer and his wife brought out the works of Sigmund Freud and books like Alexander Mitscherlich’s “Doctors of Infamy”. Through these publishing activities Bermann Fischer had a significant impact on public debates about medicine and its past in Germany.
Die Influenza 1918
Authors: Salzberger Bernd , Mohr Arno , Hitzenbichler Florian
Published: December 2018

Die Influenza 1918 war die größte Pandemie des 20. Jahrhunderts und hat eine große Zahl an Opfern gefordert. Das öffentliche Echo der Pandemie war in Deutschland aufgrund des Endes des Ersten Weltkrieges eher verhalten, allerdings wurde die Pandemie ausführlich in der wissenschaftlichen Literatur behandelt. In Europa war die Deutsche Medizinische Wochenschrift das erste Publikationsorgan, das von der Pandemie ab Juli 1918 ausführlich berichtete. Von Beginn an war die Frage des Erregers kontrovers, sie wurde 1930 endgültig geklärt. Zeitgenössische Publikationen und aktuelle Untersuchungen demonstrieren klar die prominente Rolle bakterieller Koinfektionen für die hohe Rate von Komplikationen und Todesfällen. Der Ablauf der Pandemie und die wissenschaftliche Aufarbeitung bis in die heutige Zeit werden hier dargestellt.
Mineralstoff- und Säure-Basen-Dysbalance als Risikofaktor für Wohlstandserkrankungen
Authors: Manfred Jacob Ludwig
Published: December 2018

Chronische Störungen der Säure-Basen- und Mineralstoff-Homöostase verändern unzählige biochemische Reaktionen, die Funktion von Enzymen, Membranpotenziale und Gewebe. Meist treten sie schleichend auf, sodass sie lange unbemerkt bleiben. Zahlreiche wissenschaftliche Arbeiten zeigen, dass sie maßgeblich zur Entstehung von Wohlstandskrankheiten wie Hypertonie, Insulinresistenz, chronische Müdigkeit, aber auch Schmerzen, Gicht und Nierenerkrankungen beitragen können.

Zur Erhaltung der Homöostase eignet sich generell am besten eine pflanzenbetonte Ernährung mit viel Gemüse, Obst, Kräutern, Hülsenfrüchten und Nüssen, ggf. ist eine Substitution bestimmter Nährstoffe notwendig. Ähnlich essenziell sind regelmäßige Bewegung, tiefe Bauchatmung, Phasen der Regeneration und ausreichend guter Schlaf.
Konstitutionslehren traditioneller Medizinsysteme
Authors: Uehleke Bernhard
Published: December 2018

Konstitutionslehren sind Bestandteil der meisten traditionellen Medizinsysteme. So unterscheidet beispielsweise die Dosha-Lehre im Ayurveda zwischen Vata, Pitta und Kapha, die Konstitutionslehre der traditionellen europäischen Medizin kennt die 4 Typen Choleriker, Sanguiniker, Phlegmatiker und Melancholiker. Neben den symptombezogenen spezifischen Therapiemaßnahmen werden in traditionellen Medizinsystemen zusätzliche unspezifische Therapiemaßnahmen angewendet, um eine extrem ausgeprägte Konstitution in Richtung einer günstigeren Ideal-Misch-Konstitution zu führen.

Der Autor unterzieht die Konstitutionsansätze traditioneller Medizinsysteme einer kritischen Analyse hinsichtlich ihrer Plausibilität und ihrem möglichen Nutzen für die Praxis.
Kalziphylaxie 2018
Authors: Brandenburg Vincent M.
Published: December 2018

Die Kalziphylaxie (kalzifizierende urämische Arteriolopathie) ist eine seltene,
aber dramatische Spielart der Weichteilverkalkung bei Patienten mit terminaler
Niereninsuffizienz. Noch seltener ist sie auch bei Patienten ohne nennenswerte
Nierenerkrankung 1. Die Kalziphylaxie ist
eine diagnostische und vor allem therapeutische Herausforderung. Sie trifft die
Patienten mit heftigen Einschränkungen der Lebensqualität und ist trotz aller
Fortschritte immer noch mit einem hohen Mortalitätsrisiko behaftet. Die
Ätiologie der Kalziphylaxie ist nur teilweise verstanden und in der Therapie
sind große Lücken hinsichtlich evidenzbasierter Standards zu beklagen.
Betroffene Patienten sollten in einem interdisziplinären Team und gegebenenfalls
in einem spezialisierten Zentrum betreut werden. Allerdings spricht unsere
Erfahrung aus solchen überregionalen Behandlungszentren für einen Rückgang der
Erkrankungsziffern und ein besseres Ansprechen der Therapie. Die Kooperation mit
überregionalen Registern und Netzwerken, Aufklärungskampagnen sowie eine
verbesserte Sensibilität im Umgang mit ausschaltbaren Risikofaktoren könnten
daher in den letzten Jahren doch Früchte getragen haben.
Ernährung bei chronischen Nierenerkrankungen: wann, was,
wie
Authors: Bischoff Stephan C. , Basrai Maryam
Published: December 2018

Chronische Nierenerkrankungen gehen mit metabolischen Störungen einher. Der
Nährstoffbedarf variiert erheblich und wird vielfach nicht gedeckt. Die Folge
davon sind oft schwere Mangelzustände, andererseits aber müssen Natrium, Kalium
und Phosphat beschränkt werden. Die Ernährung bei chronisch Nierenkranken ist
ein relevanter Teil der Therapie. Dieser Beitrag erläutert das praktische
Vorgehen.
Pd-Catalyzed C–H Silylation Reactions with Disilanes
Authors: Zhang Yanghui , Zhou Bo , Lu Ailan
Published: December 2018

Pd-catalyzed C–H silylation reactions remain underdeveloped. General strategies usually rely on the use of complex bidentate directing groups. C,C-Palladacycles exhibit extremely high reactivity towards hexamethyldisilane and can be disilylated very efficiently. The C,C-palladacycles are prepared through halide-directed C–H activation. This account introduces Pd-catalyzed C–H silylation reactions with di­silanes as the silyl source, and is focused on studies on the silylation of C,C-palladacycles.

1 Introduction and Background

2 Allylic C–H Silylation Reaction

3 Coordinating-Ligand-Directed C–H Silylation Reaction

4 Disilylation of C(sp2),C(sp2)-Palladacycles That are Generated by C(sp2)–H activation

5 Disilylation of C(sp2),C(sp3)-Palladacycles That are Generated by C(sp3)–H Activation

6 Disilylation of C,C-Palladacycles That are Generated through Domino Processes

7 Summary and Outlook
Die X-Chromosomale Hypophosphatämie – XLH
Authors: Genest F. , Rak D. , Böhle F. , Seefried L.
Published: December 2018

Bei der X-chromosomalen Hypophosphatämischen Rachitis (XLH) handelt es sich um eine seltene, aber mit einer Prävalenz von 1 : 20 000 gleichzeitig die häufigste genetisch bedingte Phosphatverlusterkrankung. Ursächlich sind Veränderungen im PHEX-Gen (Phosphate Regulating Endopeptidase Homolog, X-linked) auf dem X-Chromosom. Die Mutationen führen zu einer Störung der Metabolisierung des vorwiegend von Osteozyten sezernierten FGF-23 und bedingen über eine Verminderung von Natrium-Phosphat Co- Transportern in der apikalen Membran des proximalen Tubulus eine verminderte renale Phosphat-Reabsorption und eine Hemmung der 1-α-Hydroxylierung und Aktivierung von Vitamin D. In der Summe führt dies u. a. zu Phosphaturie, Hypophosphatämie und einer Mineralisierungsstörung des Knochens. Das klinische Bild im Kindesalter ist gekennzeichnet durch Zeichen der Rachitis mit Kleinwuchs und Knochendeformierungen. Im Erwachsenenalter stehen Arthralgien, (Pseudo-) Frakturen, Kontrakturen und die frühzeitige Entwicklung einer Arthrose im Vordergrund. Wesentliche Säulen der Therapie sind derzeit die Substitution von Phosphat und von unzureichend gebildetem aktivem Vitamin D. Aktuell für Kinder und zukünftig auch für Erwachsene könnte ein Antikörper gegen FGF-23 (Bursosumab) die Therapie verbessern.
Electrical response of thermoelectric generator to geometry variation under transient thermal boundary condition
Authors: Yazdanshenas Elias , Rezania Alireza , Karami Rad Meysam , Rosendahl Lasse
Published: December 2018

A three-dimensional numerical model is applied in this study to illustrate the electrical response of a thermoelectric generator (TEG) during transient heat flux at the hot side. In this work, various types of thermal boundary conditions are considered to evaluate the performance of the TEG. Thus, a TEG under pulsed heat flux is studied numerically, and the numerical model is verified by experimental results. With the consideration of a defined reference geometry, different heat flux frequencies are applied in order to evaluate the corresponding electrical output by the TEG. In addition, variation of the module performance for various TEG leg lengths and its cross-sectional area are studied over a wide range of heat fluxes. The results indicate that the open circuit voltage in the experiment is in a good agreement with the open circuit voltage in the simulation results. The results show that the range of power oscillation reduces at higher frequency of the applied heat flux. Furthermore, the variability of the output power increases as the thermoelectric element length increases and the area of the element reduces.
A priori study of the subgrid energy transfers for small-scale dynamo in kinematic and saturation regimes
Authors: Offermans Gerardus Petrus , Biferale Luca , Buzzicotti Michele , Linkmann Moritz
Published: December 2018

The statistical properties of the subgrid energy transfers of homogeneous small-scale dynamo are investigated during the kinematic, nonlinear, and statistically saturated stages. We carry out an a priori analysis of data obtained from an ensemble of direct numerical simulations on 5123 grid points and at unity magnetic Prandtl number. In order to provide guidance for subgrid-scale (SGS) modelling of different types of energy transfer that occur in magnetohydrodynamic dynamos, we consider the SGS stress tensors originating from inertial dynamics, Lorentz force, and the magnetic induction separately. We find that all SGS energy transfers display some degree of intermittency as quantified by the scale-dependence of their respective probability density functions. Concerning the inertial dynamics, a depletion of intermittency occurs in the presence of a saturated dynamo.
Plasma characterization of a microwave discharge ion source with mirror magnetic field configuration
Authors: Mallick C. , Bandyopadhyay M. , Kumar R.
Published: December 2018

Microwave coupling to plasma through cavity dependent resonant modes is one of the key aspects in a microwave discharge ion source (MDIS) for improving the ion beam qualities as well as plasma dynamics. Knowing these concerns, a MDIS is designed, fabricated, and developed at Institute for Plasma Research to produce high current and a low emittance ion beam for accelerator applications. The present manuscript reports the development of MDIS and the characterization results of the first plasma produced by launching a microwave (MW) of frequency 2.45 GHz. The plasma is characterized at a particular distance away from the ion extraction aperture, using three diagnostics tools such as a Langmuir Probe (LP), Optical Emission Spectroscopy (OES), and a microwave spectrum analyzer. The required mirror-B magnetic field is created by placing four high power ring magnets (each magnet pole strength is 1.38 T) around the cylindrical source chamber. All diagnostics measurements are performed under an operating pressure of range 2 × 10−4–1 × 10−3 mbar and the plasma absorbed power of 30–160 W. The measured cold electron temperature and density varies in the range of ∼1.5-11.8 eV and 5.6 × 1016 m−3–6 × 1017 m−3, respectively, within the source volume. The electron population has distinct hot and cold plasma temperature. The hot electron temperature changes from ∼20 to 70 eV within the above absorbed power range. The LP and OES measurements witnessed the density jumps from under-dense (∼7.3 × 1016 m−3) to over-dense (∼2.9 × 1017 m−3) for the change in absorbed power from 50 W to 80 W. This density jump is accompanied by the sideband generation around the cavity resonant mode (including the launched MW) frequencies which range from 238 kHz to 873 kHz and is recognized as ion waves from the dispersion relation. The ion temperature, estimated from these observed low frequency instabilities, changes from 0.095 to 1.25 eV. The influences of these instabilities on beam emittance growth are of paramount importance in future studies.
Step-flow growth in homoepitaxy of β-Ga2O3 (100)—The influence of the miscut direction and faceting
Authors: Schewski R. , Lion K. , Fiedler A. , Wouters C. , Popp A. , Levchenko S. V. , Schulz T. , Schmidbauer M. , Bin Anooz S. , Grüneberg R. , Galazka Z. , Wagner G. , Irmscher K. , Scheffler M. , Draxl C. , Albrecht M.
Published: December 2018

We present a systematic study on the influence of the miscut orientation on structural and electronic properties in the homoepitaxial growth on off-oriented β-Ga2O3 (100) substrates by metalorganic chemical vapour phase epitaxy. Layers grown on (100) substrates with 6° miscut toward the [001¯] direction show high electron mobilities of about 90 cm2 V−1 s−1 at electron concentrations in the range of 1–2 × 1018 cm−3, while layers grown under identical conditions but with 6° miscut toward the [001] direction exhibit low electron mobilities of around 10 cm2 V−1 s−1. By using high-resolution scanning transmission electron microscopy and atomic force microscopy, we find significant differences in the surface morphologies of the substrates after annealing and of the layers in dependence on their miscut direction. While substrates with miscuts toward [001¯] exhibit monolayer steps terminated by (2¯01) facets, mainly bilayer steps are found for miscuts toward [001]. Epitaxial growth on both substrates occurs in step-flow mode. However, while layers on substrates with a miscut toward [001¯] are free of structural defects, those on substrates with a miscut toward [001] are completely twinned with respect to the substrate and show stacking mismatch boundaries. This twinning is promoted at step edges by transformation of the (001)-B facets into (2¯01) facets. Density functional theory calculations of stoichiometric low index surfaces show that the (2¯01) facet has the lowest surface energy following the (100) surface. We conclude that facet transformation at the step edges is driven by surface energy minimization for the two kinds of crystallographically inequivalent miscut orientations in the monoclinic lattice of β-Ga2O3.
Quantumness in light harvesting is determined by vibrational dynamics
Authors: Reppert Mike , Brumer Paul
Published: December 2018

We demonstrate for the multi-level spin-boson (MLSB) Hamiltonian, typically used to describe biological light-harvesting, that the distinction between quantum and classical dynamics is determined entirely by the thermal environment. In particular, any MLSB model featuring classical interactions with a classical bath is exactly equivalent in its absorption and energy transfer dynamics to a classical model involving coupled harmonic oscillators. This result holds in the linear response regime for both pulsed and incoherent excitation. In the biological context, this finding highlights the centrality of vibrational dynamics in determining the “quantumness” of photosynthetic light-harvesting, particularly in the creation of the photosynthetic energy funnel where excitation energy concentrates near the reaction center via a series of downhill energy transfer events. These findings support the idea that this energy funnel is exclusively quantum-mechanical in origin, although it need not rely on entanglement.
Rotational coherence beating in molecular oxygen: Coupling between electronic spin and nuclear angular momenta
Authors: Courtney Trevor L. , Kliewer Christopher J.
Published: December 2018

Time-resolved pure-rotational hybrid femtosecond/picosecond coherent anti-Stokes Raman spectroscopy (fs/ps RCARS) of oxygen (O2) is performed at pressures from ∼0.04 to 0.4 atm. As the RCARS spectra evolve with probe delay, they exhibit coherence beating between unresolved S-branch triplet transitions (ΔN = 2, ΔJ = 2). The time-domain fitting of the RCARS signal intensity enables the determination of these transition frequency separations, which are as low as 480 MHz (0.016 cm−1). Additionally, we study the underlying pressure-dependent dynamics and the signatures of the time-domain triplet signals compared to the simple decays associated with the O2 self-broadened linewidths. Pressure- and N-dependent O2 linewidths are compared to literature coefficients obtained from experiments and models that have not incorporated the triplet splitting. Our findings are incorporated into a time-domain model for rotational CARS thermometry of O2 and have significant impact for spectral evaluations at probe delays greater than 100 ps for temperature or species concentration determination. The time- and frequency-resolved experiments presented in this work provide insight into the spectroscopic complexities introduced by the electronic ground state of O2 for accurate evaluation of time-resolved coherent Raman spectra.
Diagnostic signatures of performance degrading perturbations in inertial confinement fusion implosions
Authors: McGlinchey K. , Appelbe B. D. , Crilly A. J. , Tong J. K. , Walsh C. A. , Chittenden J. P.
Published: December 2018

We present 3D radiation-hydrodynamics simulations of indirect-drive inertial confinement fusion experiments performed at the National Ignition Facility (NIF). The simulations are carried out on two shots from different NIF experimental campaigns: N130927 from the high foot series and N161023 from the ongoing high density carbon series. Applying representative perturbation sources from each implosion, synthetic nuclear diagnostics are used to post-process the simulations to infer the stagnation parameters. The underlying physical mechanisms that produce the observed signatures are then explored. We find that the radiation asymmetry and tent scar perturbations extend the nuclear burn width; this is due to an asymmetric stagnation of the shell that causes the delivery of mechanical PdV work to be extended compared to an idealised implosion. Radiation asymmetries seed directed flow patterns that can result in a difference in the inferred ion temperature ranging from 80 eV to 230 eV depending on the magnitude and orientation of the asymmetry considered in the simulation; the tent scar shows no such temperature difference. For N130927, radiation asymmetries dominate the yield and inferred ion temperature and the tent scar has the largest influence on the neutron burnwidth. For N161023, the fill tube decreases the burn width by injecting mix into the hot spot, leading to a smaller hot spot and increased energy losses. Both the radiation asymmetry and the fill tube generate directed flows that lead to an anisotropic inferred temperature distribution. Through existing and novel synthetic neutron imaging techniques, we can observe the hot spot and shell shape to a degree that accurately captures the perturbations present.
Biomedical applications of 3D printing technologies
Authors: Kim Meeri
Published: December 2018

A new review paper outlines the growing popularity of 3D printing in biomedical research applications, such as medical implants and bioreactor culture platforms.
Chemical constituents and allelopathic activity of the essential oil from leaves of Eremanthus erythropappus
Authors: Pinto Ana Paula Resende , Seibert Janaína Brandão , dos Santos Orlando David Henrique , Filho Sidney Augusto Vieira , do Nascimento Andréa Mendes
Published: December 2018

The essential oil from leaves of Eremanthus erythropappus (DC.) MacLeish (Asteraceae) collected in South-eastern Brazil was extracted using a combination of water and steam distillation and investigated by chromatography/mass spectrometry (GC-MS). The sesquiterpene hydrocarbons were predominant (46.6%), followed by oxygenated sesquiterpenes (29.3%) and monoterpene hydrocarbons (18.8%). The major compounds were (β)-caryophyllene (29.3%), caryophyllene oxide (22.1%) and β-pinene (12.8%). The allelopathic activity of E. erythropappus essential oil on the seed germination and radicle length of seedlings was evaluated in lettuce (Lactuca sativa L.), tomato (Lycopersicum esculentum Mill.) and in two field weeds (field mustard – Brassica rapa L. and hairy beggarticks – Bidens pilosa L.). Among the weed species tested, the most significant inhibition of seed germination was observed in field mustard, as measured by the half–minimal inhibitory concentration, IC50 (IC50=26.5μL mL–1), and the most significant inhibitory effect on radicle length of seedlings was observed in seedlings of hairy beggarticks (IC50=16.3μL mL–1). In contrast, the lowest allelopathic effects of E. erythropappus essential oil on seed germination and radicle length of seedlings were observed in tomato (IC50=>200μL mL–1 and 130.1μL mL–1 respectively) and lettuce (IC50=97.1μL mL–1 and 35.1μL mL–1 respectively). These results revealed significant allelopathic potential of E. erythropappus essential oil against weeds, but minimal effect on lettuce and tomato germination, and thus suggests it is feasible to use E. erythropappus sustainability as an eco-friendly bioherbicide in cropping settings.
Associations between oral sex practices and frequent mouthwash use in men who have sex with men: implications for gonorrhoea prevention
Authors: Phillips Tiffany , Fairley Christopher K. , Walker Sandra , Chow Eric P. F.
Published: December 2018

Background
Rates of gonorrhoea continue to rise among men who have sex with men (MSM) in Australia and worldwide. Recently, it has been proposed that oropharyngeal gonorrhoea may play a role in its onward transmission and that mouthwash use may be an effective intervention for gonorrhoea prevention and control. The objective of this study was to determine the association between specific oral sex practices and frequency of mouthwash use. Methods: A questionnaire-based study was conducted among MSM attending the Melbourne Sexual Health Centre in Australia from March to September 2015. Logistic regression was performed to examine the association between frequent mouthwash use (i.e. daily or weekly mouthwash use) and four oral sex practices (tongue kissing, receptive fellatio with or without ejaculation, and insertive rimming) among MSM. Results: Of the 918 MSM included in the final analysis, 490 men (53.4%) were frequent mouthwash users. Participants aged 24–34 years were 2.13-fold (95% CI 1.52–2.98) and those ≥35 years were 2.64-fold (95% CI 1.83–3.83) more likely to use mouthwash frequently than those aged ≤24 years. The most common oral sex practice was tongue kissing (n=874; 95.2%), followed by receptive fellatio without ejaculation (n=839; 91.4%), receptive fellatio with ejaculation (n=610; 66.5%), then insertive rimming (n=356; 38.8%). No significant association was found between frequent mouthwash use and tongue kissing, receptive fellatio with or without ejaculation, or insertive rimming with regular or casual male partners in the previous 3 months. Conclusions: Younger MSM are less likely to use mouthwash. There is no association between engaging in oral sex practices and frequent mouthwash use among MSM.
Brain-inspired automated visual object discovery and detection
Authors: Chen Lichao , Singh Sudhir , Kailath Thomas , Roychowdhury Vwani
Published: December 2018

Despite significant recent progress, machine vision systems lag considerably behind their biological counterparts in performance, scalability, and robustness. A distinctive hallmark of the brain is its ability to automatically discover and model objects, at multiscale resolutions, from repeated exposures to unlabeled contextual data and then to be able to robustly detect the learned objects under various nonideal circumstances, such as partial occlusion and different view angles. Replication of such capabilities in a machine would require three key ingredients: (
i
) access to large-scale perceptual data of the kind that humans experience, (
ii
) flexible representations of objects, and (
iii
) an efficient unsupervised learning algorithm. The Internet fortunately provides unprecedented access to vast amounts of visual data. This paper leverages the availability of such data to develop a scalable framework for unsupervised learning of object prototypes—brain-inspired flexible, scale, and shift invariant representations of deformable objects (e.g., humans, motorcycles, cars, airplanes) comprised of parts, their different configurations and views, and their spatial relationships. Computationally, the object prototypes are represented as geometric associative networks using probabilistic constructs such as Markov random fields. We apply our framework to various datasets and show that our approach is computationally scalable and can construct accurate and operational part-aware object models much more efficiently than in much of the recent computer vision literature. We also present efficient algorithms for detection and localization in new scenes of objects and their partial views.
p47 licenses activation of the immune deficiency pathway in the tick
Ixodes scapularis
Authors: McClure Carroll Erin E. , Wang Xiaowei , Shaw Dana K. , O’Neal Anya J. , Oliva Chávez Adela S. , Brown Lindsey J. , Boradia Vishant Mahendra , Hammond Holly L. , Pedra Joao H. F.
Published: December 2018

Significance

Translocation of the nuclear factor (NF)-κB homolog Relish in response to microbial infection is a hallmark of the arthropod immune deficiency (IMD) pathway. Classically, transduction within the IMD molecular cascade is regulated by the inhibitor of apoptosis protein 2 (IAP2). In the Lyme disease
Ixodes scapularis
tick, X-linked inhibitor of apoptosis (XIAP) is considered a functionally analogous enzyme. Ticks lack homologs for some genes of the IMD network. As such, substrates of XIAP remain elusive. Here, we identify the molecule p47 as a binding partner of XIAP and Kenny (IKKγ/NEMO). We demonstrate that p47 induces a signaling cascade within the tick IMD pathway to limit microbial infection. This work emphasizes the importance of studying ticks to discover fundamental immunological processes.
Spatially resolved metabolomics to discover tumor-associated metabolic alterations
Authors: Sun Chenglong , Li Tiegang , Song Xiaowei , Huang Luojiao , Zang Qingce , Xu Jing , Bi Nan , Jiao Guanggen , Hao Yanzeng , Chen Yanhua , Zhang Ruiping , Luo Zhigang , Li Xin , Wang Luhua , Wang Zhonghua , Song Yongmei , He Jiuming , Abliz Zeper
Published: December 2018

Significance

Tumor cells reprogram their metabolism to support cell growth, proliferation, and differentiation, thus driving cancer progression. Profiling of the metabolic signatures in heterogeneous tumors facilitates the understanding of tumor metabolism and introduces potential metabolic vulnerabilities that might be targeted therapeutically. We proposed a spatially resolved metabolomics method for high-throughput discovery of tumor-associated metabolite and enzyme alterations using ambient mass spectrometry imaging. Metabolic pathway-related metabolites and metabolic enzymes that are associated with tumor metabolism were efficiently discovered and visualized in heterogeneous esophageal cancer tissues. Spatially resolved metabolic alterations hold the key to defining the dependencies of metabolism that are most limiting for cancer growth and exploring metabolic targeted strategies for better cancer treatment.
Magnesium stable isotopes support the lunar magma ocean cumulate remelting model for mare basalts
Authors: Sedaghatpour Fatemeh , Jacobsen Stein B.
Published: December 2018

Significance

Soon after the return of the first lunar samples by the Apollo missions, it became clear that the Moon is a highly differentiated object, with a plagioclase-rich crust formed by mineral flotation in a very early magma ocean. The younger lunar mare basalts were interpreted to result from remelting of these lunar magma ocean (LMO) cumulate layers. Here we report significant Mg isotope variations produced by the Moon’s early magmatic differentiation. These results support models in which lunar basalts are formed by partial melting of distinct cumulate sources produced during the LMO crystallization and imply that the bulk lunar Mg isotope composition is similar to that of the inner solar system.
Holographic acoustic tweezers
Authors: Marzo Asier , Drinkwater Bruce W.
Published: December 2018

Significance

Holographic optical tweezers use focused light to manipulate multiple objects independently without contact. They are used in tasks such as measuring the spring constant of DNA, the pulling force of the kinesin protein, or to trap matter in exotic states. Differently, acoustic tweezers use sound radiation forces to trap particles at a larger scale (i.e., from micrometers to centimeters). However, previous implementations did not provide individual control. We present the realization of holographic acoustic tweezers. Using an array of sound emitters, we engineer the generated sound field to manipulate multiple particles individually. This enables applications in contactless assembly both at the micrometer and centimeter scale as well as the creation of displays in which the pixels are levitating particles.
Dietary sugar silences a colonization factor in a mammalian gut symbiont
Authors: Townsend Guy E. , Han Weiwei , Schwalm Nathan D. , Raghavan Varsha , Barry Natasha A. , Goodman Andrew L. , Groisman Eduardo A.
Published: December 2018

Significance

Diet is known to alter the gut microbiota composition by supplying nutrients that promote the expansion of particular microorganisms. However, we demonstrate that fructose, a common dietary additive in the Western world, decreases the abundance of a regulator of gut colonization in the human gut commensal
Bacteroides thetaiotaomicron
. Rendering the levels of this colonization factor refractory to silencing by fructose confers an advantage in mice fed a fructose-rich diet. We provide a singular example of the host diet controlling the amounts of a bacterial protein necessary for murine gut colonization by a beneficial gut commensal bacterium, but dispensable for growth on such dietary components.
Discriminatory language in the workplace: unmasking prejudices and stereotypes / El lenguaje discriminatorio en contextos laborales: desenmascarando prejuicios y estereotipos
Authors: Di Marco Donatella , Arenas Alicia , Munduate Lourdes , Hoel Helge
Published: December 2018

The link between language, communication and open discrimination has been the focus of numerous studies. For many years, language has been a vehicle of prejudice and negative stereotypes. However, in the last few years, overt verbal aggressions have diminished thanks to the implementation of equality policies and awareness-raising initiatives. Despite that, negative attitudes against protected groups might not have disappeared and may instead be transmitted subtly, such as through uncivil language. The goal of this research is to study the relation between language and subtle discrimination against lesbian and gay (LG) workers. With this goal in mind, 39 in-depth interviews were conducted. The analysis showed that LG people are victims of subtle discrimination and that language is one of the most common vehicles of prejudice and negative stereotypes. Jokes, inappropriate comments and questions are the expression of negative attitudes, which are probably present at an implicit level. Due to the ambiguity of these expressions and the settings where they have been studied — the workplace — these acts could be defined as uncivil behaviours. Practical implications, limitations and directions for future research are discussed.
Friendship in politics, community, populism and liberalism: a response to Nordin and Smith
Authors: Roberts Adam
Published: December 2018

This response looks first at the authors’ suggestion that friendship is a useful concept for understanding and shaping politics and agrees that it is commonly used, though its meaning is commonly understood as different from the one proposed by the authors. Secondly, it focuses on their argument that friendship could serve as ‘a politics beyond community’, asking if friendship is not more easily understood as a sub-set of community or the means to building a community of the like-minded. Thirdly, it comments on the links of community and populism, noting that the populism is a recurring phenomenon and not exclusively rooted in European thought. Lastly, while agreeing that the proposed ethos is welcome, it asks how much it differs from other ideas, notably liberal, universal values that are built on the idea of individual rights, including a belief in tolerance, moderation and respect for political views that differ from one's own.