bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of menopausal hormone therapy on bone and body composition
Authors: Papadakis Georgios E , Lamy Olivier
Published: May 2019

Die Wechseljahre sind durch tiefgreifende klinische und hormonelle Veränderungen gekennzeichnet. Ein Östrogenmangel führt zu einem beschleunigten Knochenverlust und erhöhtem Frakturrisiko. Parallel dazu deuten Verlaufs-Studien auf einen Anstieg der Adipositas mit einer Neigung zu mehr zentralem Fett sowie einen Verlust an Muskelmasse hin. Die post-menopausale Hormontherapie (MHT), die derzeit auf die symptomatische Linderung von Hitzewallungen und andere klimakterische Symptome beschränkt ist, hat sich als wirksam erwiesen, um die Knochendichte zu erhalten. Jüngste Daten der OsteoLaus-Kohorte, einer bevölkerungsbasierten Studie mit postmenopausalen Frauen im Alter von 50–80 Jahren, deuten darauf hin, dass zusätzlich ein günstiger Effekt auf die Mikroarchitektur der Knochen vermittelt wird. Darüber hinaus haben Frauen unter MHT, weniger androides und viszerales Fett, entsprechend der verfügbaren Daten aus anderen Studien. Die Physiopathologie dieses Zusammenhangs ist nicht vollständig geklärt und kann Änderungen des Energieverbrauchs durch Östrogene betreffen. Im Gegenteil scheint die Wirkung der MHT auf die Magermasse begrenzter zu sein und könnte mit spezifischen Arten MHT oder dem zeitlichen Einsatz der MHT in Verbindung gebracht werden. Interessanterweise ist die Entwicklung nach dem MHT-Entzug in verschiedenen Geweben nicht identisch, wobei der Verlust des Nutzens für das Fettgewebe schneller eintritt. In Anbetracht des erneuten Interesses von MHT, zumindest für Frauen in der frühen Postmenopause, können diese Daten bei der Erwägung einer MHT wertvoll sein.
Research on combustion flow field imaging method based on ray casting algorithm
Authors: Yao Min , Zhang Yueqi , Zhao Min , Guo Ruipeng , Xu Jun
Published: May 2019

Measurement of flame or combustion is an important method to estimate combustion quality, study the performance of engine and develop renewable energy sources. This paper presents a method to detect the combustion flow field in a confined space using Positron Emission Tomography (PET) technology. Radionuclides are labelled in aviation kerosene, and the nuclides are distributed in the confined space along with the kerosene in the process of combustion. γ photons generated by the decay of the nuclides in the combustion region are detected by the detectors around the object. Each pair of γ photons with 511keV travelling in opposite directions within a short time window are detected as a line of response (LOR). The distributions of nuclide concentrations in the combustion region, which are related to the combustion flow field, are estimated through the counts of LORs at different angles and positions. In order to display the combustion flow field based on human visual features, ray casting algorithm is used to reconstruct the 3D image with the slice images got from PET. Due to the complexity of ray casting algorithm, the interpolation algorithm in ray casting algorithm is optimized. The experiment results show that the image construction speed is improved with the optimized ray casting algorithm. The constructed 3D image can display the combustion flow field from different viewpoints.
Optoelectronic characteristics of the Ag-doped Si p-n photodiodes prepared by a facile thermal diffusion process
Authors: El-Amir Ahmed A. M. , Ohsawa Takeo , Ishii Satoshi , Imura Masataka , Segawa Hiroyo , Sakaguchi Isao , Nagao Tadaaki , Shimamura Kiyoshi , Ohashi Naoki
Published: May 2019

For the full benefit of the silicon chip industry and to further shift the photoresponse cut-off wavelength of the silicon photodetectors, high-performance Ag-doped Si p-n photodiodes with an extended infrared photoresponsivity are constructed on the bulk silicon wafer by a facile thermal diffusion process at 550 °C for different annealing periods of 5, 10, and 15 minutes under an argon atmosphere. These Si-compatible p-n photodiodes revealed an obvious zero-bias room temperature photoresponsivity with a threshold photon energy at a longer wavelength compared to the photoresponsivity cut-off wavelength of the commercial Si photodiode of the Hamamatsu Photonics Co (model: S2281/-04). The photoresponsivity has decreased with the annealing time increase however; the detectivity has been improved by the significant drop in leakage current and noise power. The outcomes indicate that this study paves the way for developing cost-effective Si-compatible p-n junction photodiodes, with an obvious zero-biased room-temperature photoresponsivity of a comparable intensity and longer cut-off wavelength compared to the commercial Hamamatsu Si photodiode.
Surface structure chemical transfer method to fabricate low reflectance multi-crystalline Si wafers produced with fixed abrasive machining technology
Authors: Kunieda Shogo , Imamura Kentaro , Kobayashi Hikaru
Published: May 2019

Conventional acidic etching cannot form low reflectance surfaces from multi-crystalline silicon (multi-Si) wafers sawn by fixed abrasive (FXA) machining technology, which makes it difficult to replace the time- and cost-consuming free abrasive (FRA) machining method. In the present work, a nanocrystalline Si (nc-Si) layer is formed by use of the surface structure chemical transfer (SSCT) method, and the layer is used as a starting point of alkaline etching to fabricate low reflectance submicron texture on FXA multi-Si wafers. Although the nc-Si layer cannot be passivated by deposition of a silicon nitride (SiN) layer, the submicron textured surface formed from the nc-Si layer by alkaline etching can effectively be passivated by the SiN layer. Using the developed method, the SiN passivated submicron textured FXA multi-Si wafers possess both high minority carrier lifetime and lower reflectance than that of acidic textured FRA multi-Si wafers. The excellent passivation effect of the SiN layer on the low reflectance textured surface is attributed to the low interface state density of 1.2×1011 cm-2eV-1.
Effects of plasmoid formation on sawtooth process in a tokamak
Authors: Ali A. , Zhu P.
Published: May 2019

For realistic values of the Lundquist number in tokamak plasmas, 1/1 magnetic islands lead to the formation of a secondary thin current sheet, which breaks up into a chain of small magnetic islands, called plasmoids. The role of plasmoid dynamics during the sawtooth reconnection process in fusion plasmas remains an unresolved issue. In this study, systematic simulations are performed to investigate the resistive internal kink mode using the full resistive magnetohydrodynamics equations implemented in the NIMROD code in a simplified tokamak geometry. For Lundquist number S≥1.6×107, the secondary current sheet is found to be unstable to plasmoids during the nonlinear resistive kink mode evolution with a critical aspect ratio of the current sheet of ∼70. The merging of small plasmoids leads to the formation of a monster plasmoid that can significantly affect the primary island evolution. This may provide an explanation for the partial reconnection observed in sawtooth experiments.
Role of the pre-plasma on electron beam currents from a biased laser-plasma
Authors: Versteegen Maud , Raymond Xavier , Gobet Franck , Henares Jose Luis
Published: May 2019

We are investigating laser-plasmas produced in the interaction of a 1 J 9 ns Nd:YAG laser with a solid metal target as a source of electrons. An electron beam pulsed at the laser repetition rate is produced by biasing the target and making the plasma expand in an electric field. In this paper, we focus on the measured beam currents and charge surface distribution of the beam. The peak beam currents are much higher than what is given by a simplified toy model based on the Child-Langmuir limit in a vacuum and the charge surface distributions are inhomogeneous. Both these observations are explained by the presence of a positive preplasma expanding ahead of the laser-plasma front edge.
Convection pattern formation in a domain with a horizontal interface
Authors: Holzbecher Ekkehard
Published: May 2019

For the classical constellation of a fluid heated from below and cooled at the top, convection patterns are examined, with the additional feature of a horizontal interface. The interface separates two subdomains of different types, which contain porous media with different properties. The case of a pure diffusive layer at the bottom and the case of a free fluid above a porous medium are considered also. It is outlined that the approach can also be valid for the case of haline convection. Using finite element modeling for the nondimensional formulation, 2-dimensional transient and steady state convection patterns are visualized and examined. The simulations show that the interface significantly changes the convection cells in the domain as well as the heat transfer through the system. In all cases, the emerging pattern on one side of the interface is related to the pattern on the other side. The results are relevant for the understanding of heat and mass flow through layered geological strata, at the bottom of water bodies and in technical devices, for example layered insulation systems.
Sound insulation properties of a spherical structure of subwavelength size
Authors: Han Jianning , Qin Jiajie , Zhou Zhiyu , Ji Xinrui , Su Yuchao , Tang Shuai
Published: May 2019

Because of the limited sound insulation provided by a single material, it is common to use multiple layers of materials to improve the effects of sound insulation, but multiple materials increase the size of the model. In some cases, there are limits to the size of the model, or, if subwavelength sizes are required, it is necessary to investigate wideband sound insulation of subwavelength size. We designed a coded topological spherical model on the subwavelength scale, with two materials arranged periodically according to the coding idea. The results showed that at the subwavelength scale, the sound insulation effect of the coded topological spherical model was very significant; the sound pressure after using sound insulation was near 0.3 Pa, but the incident sound pressure was 100 Pa. These results overcome the excessive thickness problem of traditional materials used in sound insulation, which has long puzzled researchers, and expands the application of new sound insulation materials in the energy collection field.
Simulations on photovoltaic conversion in perovskite solar cells by solving hierarchical equations of motion
Authors: Cao Hui , Wang Shurong , Zhang Mingdao , Tao Tao , Sun Jinwei , Ma Jing
Published: May 2019

Understanding the mechanism of photovoltaic conversion in perovskite solar cells (PSCs) remains a great challenge. In this work, we have simulated the charge generation, transport and recombination in PSCs under standard AM 1.5G sunlight on the basis of solving hierarchical equations of motion with model Hamiltonian. Reasonable current/voltage characteristics, power conversion efficiency (PCE), and incident photon to current conversion efficiency (IPCE) can be obtained by investigating different interaction with respect to the interfacial recombination. Moreover, it is found that the interfacial charge transfer (CT) states can greatly affect the current/voltage characteristics, which is elucidated by analyzing the density of states. Dynamics response of current to sunlight or bias is demonstrated and the intrinsic temperature effect on PCE is also discussed.
Water in the hydrated protein powders: Dynamic and structure
Authors: Sasaki Kaito , Popov Ivan , Feldman Yuri
Published: May 2019

It is not an understatement to say that the interplay between water and protein is a fundamental aspect of life. The vitality of an organism depends on the functionality of its biological machinery, and this, in turn, is mediated in water. Yet, we understand surprisingly little about the nature of the interface between bulk water and the protein. On the one hand, we know that the nature of the bulk water is dominated by the existence of H-bonding and H-bonded networks. On the other hand, the protein surface, where much of the bioactivity is centered, is a complex landscape of hydrophilic and hydrophobic elements. So how does the interface between these two entities work and how do they influence each other? The question is important because if one understands how a particular protein interface influences the dynamics of the water, it then becomes an easily accessible marker for similar behavior in other protein systems. The dielectric relaxation of hydrated proteins with different structures, lysozyme, collagen, and phycocyanin, has been reviewed in this paper. The dynamics of hydrated water was analyzed in terms of orientation and the ionic defect migration model. This approach enables to characterize the microscopic relaxation mechanism of the dynamics of hydration water on the different structures of the protein. In addition, our model is also capable of characterizing not only hydrated proteins but also polymer-water systems.
Dynamics of uncertainties for one-dimensional semiclassical wave packets: Isochronicity, scattering, and capture
Authors: Punoševac Predrag , Robinson Sam L.
Published: May 2019

We complete our study on the uncertainties in position and momentum associated with the semiclassical Hagedorn wave packets by first filling in a technical gap in the dynamics of bound states for isochronous potentials. We then consider scattered states and show that, if the packet is reflected from the potential or transmitted through a symmetric potential, then a minimal uncertainty “initial” state cannot in general lead to a “final” state with minimal uncertainty, and we give an explicit relationship for the difference in terms of a characteristic time associated with classical trajectories. We also characterize the behavior of the uncertainty product in the case where the underlying classical dynamics lead to capture by the potential.
Critical thickness of hexagonal GaBN/BN heterostructures
Authors: Wang Q. W. , Li J. , Lin J. Y. , Jiang H. X.
Published: May 2019

We report the growth of hexagonal boron gallium nitride alloys, h-GaxB1−xN, on hexagonal boron nitride (h-BN) templates by metalorganic chemical vapor deposition and the observation of the critical thickness (LC) phenomenon in the h-GaBN/BN heterostructure system. It was observed that GaxB1−xN alloys in a pure hexagonal phase can be obtained when the film thickness is below LC. X-ray diffraction (XRD) θ–2θ measurement results revealed the formation of separate wurtzite (w)-GaN domains within the h-GaBN matrix when the film thickness is beyond LC. XRD results were supported by photoluminescence spectroscopy which revealed the absence of the band edge emission of w-GaN near 3.4 eV in very thin layers, but an increase in the w-GaN band edge emission with an increase in the h-GaxB1−xN layer thickness beyond LC. Despite the fact that layered structured materials generally possess a weak interlayer interaction, our results revealed that phase separation still occurs in layered h-GaxB1−xN alloys and the critical thickness depends on the Ga composition. The present study also provided insights into possible ways to synthesize layered GaBN/BN heterostructures and quantum wells in the pure hexagonal phase with tunable bandgaps and optical properties, which would open up many new applications.
In situ investigations of interfacial degradation and ion migration at CH3NH3PbI3 perovskite/Ag interface
Authors: Li Xiong , Ding Hong-he , Li Gui-hang , Wang Yan , Fang Zhi-min , Yang Shang-feng , Ju Huan-xin , Zhu Jun-fa
Published: May 2019

Interfacial properties between perovskite layers and metal electrodes play a crucial role in the device performance and the long-term stability of perovskite solar cells. Here, we report a comprehensive study of the interfacial degradation and ion migration at the interface between CH3NH3PbI3 perovskite layer and Ag electrode. Using in situ photoemission spectroscopy measurements, we found that the Ag electrode could induce the degradation of perovskite layers, leading to the formation of PbI2 and AgI species and the reduction of Pb2+ ions to metallic Pb species at the interface. The unconventional enhancement of the intensities of I 3d spectra provides direct experimental evidences for the migration of iodide ions from CH3NH3PbI3 subsurface to Ag electrode. Moreover, the contact of Ag electrode and perovskite layers induces an interfacial dipole of 0.3 eV at CH3NH3PbI3/Ag interfaces, which may further facilitate iodide ion diffusion, resulting in the decomposition of perovskite layers and the corrosion of Ag electrode.
Role of hydrogen migrations in carbonyl peroxy radicals in the atmosphere
Authors: Wang Sai-nan , Wu Run-run , Wang Li-ming
Published: May 2019

Carbonyl peroxy radicals (RC(O)O2) are the ubiquitous radical intermediates in the atmospheric oxidation of volatile organic compounds. In this work, theoretical studies are carried out to explore the role of the unimolecular H-migration in the carbonyl peroxy radicals by using quantum chemistry and kinetics calculations. The results showed that H-migration could be significant in the atmosphere at least in CH3CH2CH2C(O)O2 and (CH3)2CHCH2C(O)O2 with rates of ~0.012 and ~0.58 s−1 at 298 K. Subsequent reactions of CH3CHCH2C(O)OOH would lead to the products with multi-functional groups, which might affect the aerosol formation process; while (CH3)2CCH2C(O)OOH would transform to formaldehyde and acetone in a few steps. These processes would be important for the atmospheric modelling of volatile organic compounds under low-NOx conditions.
Adjustment in tumbling rates improves bacterial chemotaxis on obstacle-laden terrains
Authors: Rashid Sabrina , Long Zhicheng , Singh Shashank , Kohram Maryam , Vashistha Harsh , Navlakha Saket , Salman Hanna , Oltvai Zoltán N. , Bar-Joseph Ziv
Published: May 2019

Significance

Bacterial chemotaxis is the process of bacterial migration in the direction of food and/or a chemoattractant and away from chemorepellents. Several models have been proposed for this process and these predict that their migration across obstacle-laden terrains would be slower when compared with terrains that do not contain obstacles. However, our experiments show that the presence of obstacles does not alter the average time it takes
Escherichia coli
cells to reach the food source. We show, both theoretically and experimentally, that a modified model that relies on adaptive movement following collisions with obstacles accurately explains this surprising result. These findings imply operational short-term memory of bacteria and motivate improved algorithms for self-autonomous robotic swarms.
Histone deacetylase 4 promotes type I interferon signaling, restricts DNA viruses, and is degraded via vaccinia virus protein C6
Authors: Lu Yongxu , Stuart Jennifer H. , Talbot-Cooper Callum , Agrawal-Singh Shuchi , Huntly Brian , Smid Andrei I. , Snowden Joseph S. , Dupont Liane , Smith Geoffrey L.
Published: May 2019

Significance

Histone deacetylases (HDACs) are regulators of host gene expression. HDAC4 is shown here to have an important role in type I interferon (IFN) signaling. Here, multiple cell lines lacking HDAC4 had impaired responses to IFN-α and were rescued by reintroduction of HDAC4. The biological significance of HDAC4 was demonstrated by the enhanced replication and spread of two DNA viruses, vaccinia virus (VACV) and herpes simplex virus type I, in HDAC4
−/−
cells, and their diminished replication when HDAC4 was overexpressed. Furthermore, HDAC4 was targeted for proteasomal degradation early after infection with VACV, and VACV protein C6, an inhibitor of type I IFN signaling, was necessary and sufficient for this degradation. In summary, HDAC4 is a restriction factor for large DNA viruses.
Direct high-resolution mapping of electrocatalytic activity of semi-two-dimensional catalysts with single-edge sensitivity
Authors: Sun Tong , Wang Dengchao , Mirkin Michael V. , Cheng Hao , Zheng Jin-Cheng , Richards Ryan M. , Lin Feng , Xin Huolin L.
Published: May 2019

Significance

A major challenge in electrocatalysis is pinpointing active sites on the surface, particularly when they are at the atomic scale. Direct electrochemical measurements of individual materials’ edges have not yet been reported. Here we use the scanning electrochemical microscope (SECM) to independently image topography and local catalytic activity. The 15-nm spatial resolution and high sensitivity allowed us to distinguish the higher activities of the materials’ edges from that of the fully coordinated surfaces
in operando
. The spatially resolved electrochemical information combined with state-of-the-art electron tomography that unravels the three-dimensional complexity of the edges and ab initio calculations revealed the intricate coordination-dependent catalytic activity of the Ni oxide nanosheet edge that is not accessible by other methods.
Mechanism of CAP1-mediated apical actin polymerization in pollen tubes
Authors: Jiang Yuxiang , Chang Ming , Lan Yaxian , Huang Shanjin
Published: May 2019

Significance

Actin polymerization drives rapid polarized pollen tube growth, but the mechanism underlying actin polymerization within the growth domain of pollen tubes remains incompletely understood. We here identify CAP1 as a major player in driving actin polymerization via recharging ADP-G-actin and facilitating the formation and maintenance of a pool of polymerization-competent actin monomers in a manner that involves the nucleotide exchange activity of CAP1 in pollen tubes. Our study directly links the actin nucleotide exchange activity of CAP1 to its role in promoting actin polymerization. Our study thus significantly enhances our understanding of the mechanism of actin polymerization in pollen tubes.
Mosaic origin of the eukaryotic kinetochore
Authors: Tromer Eelco C. , van Hooff Jolien J. E. , Kops Geert J. P. L. , Snel Berend
Published: May 2019

Significance

Eukaryotes, which include diverse species like animals, fungi, and plants, have cells that are fundamentally more complex than prokaryotic cells, such as bacteria. However, eukaryotes did evolve from prokaryotes, so they must have acquired this cellular complexity after they diverged from prokaryotes. A key cellular feature unique to eukaryotes is the kinetochore, a large, multiprotein structure that plays an essential role in cell division. Here we shed light on the origination of the kinetochore by studying the evolution of its proteins. We find that the kinetochore has diverse evolutionary roots and that it expanded via gene duplications. We present a mode by which eukaryotic systems originated and illuminate the prokaryote-to-eukaryote transition.
MZB1 promotes the secretion of J-chain–containing dimeric IgA and is critical for the suppression of gut inflammation
Authors: Xiong Ermeng , Li Yingqian , Min Qing , Cui Chaoqun , Liu Jun , Hong Rongjian , Lai Nannan , Wang Ying , Sun Jiping , Matsumoto Ryohtaroh , Takahashi Daisuke , Hase Koji , Shinkura Reiko , Tsubata Takeshi , Wang Ji-Yang
Published: May 2019

Significance

IgA is the most abundantly produced antibody in the body (in humans, >5 g/d) and plays a crucial role in mucosal immunity. IgA forms a dimer that covalently associates with the joining (J) chain, which is essential for IgA transport into the gut. We show that MZB1 is required for the secretion of IgA, but not IgG, by antibody-secreting plasma cells. MZB1 mediates the stabilization of Igα heavy-chain–light-chain complexes and, more importantly, promotes J-chain binding to IgA. Mice lacking MZB1 are impaired in secreting large amounts of IgA into the gut in response to acute inflammatory stimuli and develop severe colitis. The present study reveals an important mechanism that controls the quantity, quality, and function of IgA.
Multifunctional graphene supports for electron cryomicroscopy
Authors: Naydenova Katerina , Peet Mathew J. , Russo Christopher J.
Published: May 2019

With recent technological advances, the atomic resolution structure of any purified biomolecular complex can, in principle, be determined by single-particle electron cryomicroscopy (cryoEM). In practice, the primary barrier to structure determination is the preparation of a frozen specimen suitable for high-resolution imaging. To address this, we present a multifunctional specimen support for cryoEM, comprising large-crystal monolayer graphene suspended across the surface of an ultrastable gold specimen support. Using a low-energy plasma surface modification system, we tune the surface of this support to the specimen by patterning a range of covalent functionalizations across the graphene layer on a single grid. This support design reduces specimen movement during imaging, improves image quality, and allows high-resolution structure determination with a minimum of material and data.
Implantable multireservoir device with stimulus-responsive membrane for on-demand and pulsatile delivery of growth hormone
Authors: Lee Seung Ho , Piao Huiyan , Cho Yong Chan , Kim Se-Na , Choi Goeun , Kim Cho Rim , Ji Han Bi , Park Chun Gwon , Lee Cheol , Shin Chong In , Koh Won-Gun , Choy Young Bin , Choy Jin-Ho
Published: May 2019

Significance

We propose an implantable multireservoir device equipped with stimulus-responsive membrane to allow for on-demand and pulsatile drug delivery. The stimulus-responsive membrane is made of a thermosensitive polymer, POSS(MEO
2
MA-co-OEGMA), and photothermal nanoparticles of reduced graphene oxide. Each of the drug reservoirs is filled with the same amount of human growth hormone and capped with the stimulus-responsive membrane. Therefore, when implanted in living animals, the device herein can deliver drug reproducibly by rupturing a stimulus-responsive membrane only at the times of near-infrared irradiation applied from the outside body without showing complications.
A medium-Mn steel processed by novel twin-roll strip casting route
Authors: Wang Hesong , Zhang Yuanxiang , Ran Rong , Wang Yang , Kang Jian , Li Yunjie , Misra R. D. K. , Yuan Guo , Wang Guodong
Published: May 2019

A medium-Mn steel (Fe–0.3C–4Mn–1.82Al–0.6Si wt-%) was produced by a novel processing route involving twin-roll strip casting, hot rolling and intercritical annealing (IA). Macrosegregation was absent in the as-cast strip. The microstructure of the as-cast strip consisted of martensite and austenite (∼10 vol.-%), and the solidification structure was characterised by dendritic structure. With an increase in IA temperature from 680 to 725 and to 755°C, austenite fraction in intercritically annealed steels was increased from 22 to 45% and then decreased to 27%. The 710°C intercritically annealed steel yielded excellent mechanical properties with a tensile strength of ∼1007 MPa and total elongation of ∼48%, achieved by a high volume fraction of austenite (∼42%) with appropriate mechanical stability.
Creep behaviour and microstructural evolution of AlxCrMnFeCoNi high-entropy alloys
Authors: Cao C. M. , Xu J. , Tong W. , Hao Y. X. , Gu P. , Peng L. M.
Published: May 2019

The creep deformation behaviour of thermo-mechanically treated Al xCrMnFeCoNi high-entropy alloys was investigated in the high-temperature range of 600–700°C. Compared with the Al-free CrMnFeCoNi alloy, the Al xCrMnFeCoNi alloys showed higher creep resistance under the same creep conditions due to strengthening contribution from elemental Al. The Al0.4CrMnFeCoNi alloy exhibited a stress-dependent transition from the low-stress region to high-stress region. The Al0.6CrMnFeCoNi alloy showed decreased creep resistance compared to the Al0.4CrMnFeCoNi alloy, which was ascribed to the higher activation volume and stacking-fault energy in the former alloy. Specifically, the intragranular formation of Cr-rich σ precipitation was widely found in the matrix grain among testing conditions, indicating a striking atomic diffusion process due to the limited entropic stabilisation in Al-containing CrMnFeCoNi alloys.
A customized multispectral needle probe combined with a virtual photometric setup for in vivo detection of Lewis lung carcinoma in an animal model
Authors: Braun Frank , Schalk Robert , Nachtmann Marcel , Hien Andreas , Frank Rudolf , Beuermann Thomas , Methner Frank-Jürgen , Kränzlin Bettina , Rädle Matthias , Gretz Norbert
Published: May 2019

Optical systems applied for tissue analysis are primarily based on single spectroscopic techniques. This paper however presents a multispectral backscattering sensor designed for in vivo application by a specially formed probe tip which allows side by side monitoring of ultraviolet, visible, near-infrared and fluorescence spectra. The practical applicability of the measurement system was demonstrated in vitro (muscle and adipose tissue) and in vivo in an animal model (mouse). By comparing associated measuring changes in biochemical, physical-morphological and colorimetric values this procedure allows a differentiation between healthy, marginal and malignant tissue.
Mechanics of tissue competition: interfaces stabilize coexistence
Authors: Ganai Nirmalendu , Büscher Tobias , Gompper Gerhard , Elgeti Jens
Published: May 2019

Mechanical forces influence the dynamics of growing tissues. Computer simulations are employed to study the importance of interfacial effects in tissue competition. It was speculated previously that mechanical pressure determines the competition, where the determining quantity is the homeostatic pressure-the pressure where division and apoptosis balance; the tissue with the higher homeostatic pressure overwhelms the other. In contrast, we find that a weaker tissue can persist in stable coexistence with a stronger tissue, if adhesion between them is small enough. An analytic continuum description can quantitatively describe the underlying mechanism and reproduce the resulting pressures and cell-number fractions. Furthermore, simulations reveal a variety of coexisting structures, ranging from spherical inclusions to a bicontinuous state.
Electron–hole collisions in an atomically thin semiconductor
Authors: Langer F , Schmid C P , Schlauderer S , Nagler P , Schüller C , Korn T , Gmitra M , Fabian J , Hawkins P G , Huttner U , Steiner J T , Koch S W , Kira M , Huber R
Published: May 2019

Strong-field biasing of a solid with intense lightwaves leads to simultaneous interband excitation and intraband acceleration of electron–hole pairs. These coupled dynamics result in high-harmonic emission from the bulk solid. For a controlled acceleration of quasiparticles with well-defined initial conditions, we prepare coherent electron–hole pairs by a resonant near - infrared pulse before a strong multi-terahertz field accelerates these entities. The ballistic dynamics manifests itself as high-order sidebands to the near-infrared excitation spectrum. This mechanism allows for the implementation of a quasiparticle collider in order to study those entities in close analogy to conventional collision experiments. Accelerating electrons and holes in a monolayer of a transition metal dichalcogenide extends this scheme to internal quantum degrees of freedom. We show how a strong lightwave can transport electron–hole pairs from one valley to the other faster than one oscillation of the carrier wave, effectively switching the valley pseudospin on a sub-cycle scale. This scheme paves the way to ultimately fast valleytronics.
Ultrafast electronic relaxation dynamics in a valence fluctuation material Sm0.83Y0.17S
Authors: Ikeda Ryohei , Watanabe Hiroshi , Negoro Yusuke , Takeno Yusuke , Imura Keiichiro , Suzuki Hiroyuki S. , Sato Noriaki K. , Kimura Shin-ichi
Published: May 2019

We report ultrafast electronic relaxation dynamics of yttrium-doped samarium monosulfide, Sm0.83Y0.17S, which is one of valence fluctuating compounds, by pump-probe measurements. We observed a large increase of the Drude weight in the reflectivity spectrum by the photo-excitation and a double exponential decay of the relaxation time to a metastable state. This suggests that the photo-induced effect can be explained as the change of carrier density. The metastable state has a long lifetime ( > 1 ns) and the carrier density is slightly higher than that before the photo-excitation.
Temperature dependence of photoluminescence properties of water-soluble CdS quantum dots
Authors: Shimura Kunio , Lee TaeGi , Kim DaeGwi
Published: May 2019

We investigated the size dependence of band-edge photoluminescence (PL) dynamics for CdS quantum dots (QDs). The temperature dependence of the PL-decay profiles of CdS QDs with an average diameter of 3.7–6.0 nm was measured. The PL-decay profiles became longer as the temperature increased. Further, it was found that the temperature dependence of the PL-decay profiles depends greatly on the QD size. These experimental results can be understood by considering that the magnitude of the splitting energy between the bright-and dark-exciton states depends on the QD size and becomes larger as the QD size becomes smaller.
Raman imaging studies on perforated MoS2 films prepared by RF sputtering method
Authors: Hasuike N , Yamauchi S , Nishio K , Kamoi S , Yoo Woo Sik , Kisoda K
Published: May 2019

We investigated the spatial distribution of the crystallinity for sputtered-MoS2 films by Raman imaging technique. MoS2 lattice could not be structured in as-sputtered sample prepared at room temperature. The crystallinity could be improved by thermal annealing at 630 oC in vacuum condition. However, annealed MoS2 films had two kinds of circular perforated areas on their top surface. In one area, MoS2 film was evaporated and the substrate was exposed. In another area, MoS2 films formed a hillock shape and showed tensile strain. In addition, the crystallinity was deteriorated in hillock formed area, which is due the generation of sulfur vacancies by thermal annealing.
Detection of optical force due to multiphoton absorption
Authors: Nakamura S , Sunakawa R , Setoura K , Ito S , Miyasaka H
Published: May 2019

Resonant optical manipulation using absorption force so far has been based on the linear (one-photon) absorption by target material, while optical forces due to multiphoton absorption have not been much investigated. As multiphoton absorption obeys different selection rule from that of one-photon absorption, and also shows non-linear dependence on light intensity, a larger variety of photo-mechanical responses of small particles can be expected by using multiphoton absorption force. In this study, we focused femtosecond laser pulses to a single polymer microparticle containing fluorescence dyes to exert multiphoton absorption force on the particle. We successfully observed the three-dimensional motion of the photo-irradiated microparticle due to the multiphoton absorption.
Anomalous Hanle curves induced by in-plane nuclear field in single self-assembled InAlAs and InAs nanostructures
Authors: Yamamoto S. , Matsusaki R. , Kaji R. , Adachi S.
Published: May 2019

We studied the formation mechanism of in-plane nuclear field by anomalous Hanle effect measurements in single self-assembled In0.75Al0.25As/Al0.3Ga0.7As quantum dots and InAs/GaAs quantum rings. The observed anomalous Hanle curves indicated quite large width and hysteretic behavior to the externally applied magnetic field. These anomalies appears in both materials whose electron g factors have opposite sign each other, and cannot be reproduced by a traditional spin dynamics model. In this study, we show that a proposed spin dynamics model can explain the formation of a large in-plane nuclear field regardless of the sign of electron g factor. The model is based on the dynamic nuclear spin polarization mechanism including the effects of nuclear quadrupole interaction.
Q-factor dependence of angle-resolved transmission spectra in CuCl microcavities
Authors: Yokoyama T , Nishida T , Oohata G , Mizoguchi K
Published: May 2019

We have investigated the angle-resolved transmission spectra of the CuCl λ-and λ/2-microcavities composed of cavity layers sandwiched by distributed Bragg reflectors (DBRs) with various numbers of periods of the DBR layer which affect the degree of confinement of the photons in the microcavity, so-called quality factors (Q factors). The angle-resolved transmission spectra of the CuCl microcavities drastically change with the Q factor and the thickness of the cavity layer. The incident angle dependence of the peak energies obtained from the angle-resolved transmission spectra indicates that the cavity polariton modes are observed in the CuCl microcavities, except for the λ-microcavity with 2 periods of the DBR layer. The change of the angle-resolved transmission spectra in the microcavities will result from the difference in the coupling state between the excitons and photons in the microcavities.
Increased levels of soluble Receptor for Advanced Glycation End-products (RAGE) are associated with a higher risk of mortality in frail older adults
Authors: Butcher Lee , Carnicero Jose A , Gomez Cabrero David , Dartigues Jean-François , Pérès Karine , Garcia-Garcia Francisco Jose , Rodriguez-Mañas Leocadio , Erusalimsky Jorge D ,   FRAILOMIC Consortium
Published: May 2019

Objective

to evaluate the relationship between serum levels of the soluble Receptor for Advanced Glycation End-products (sRAGE) and mortality in frail and non-frail older adults.

Methods

we studied 691 subjects (141 frail and 550 non-frail) with a median age of 75 years from two population-based cohorts, the Toledo Study of Healthy Aging and the AMI study, who were enrolled to the FRAILOMIC initiative. Multivariate Cox proportional hazards regression and Kaplan–Meier survival analysis were used to assess the relationship between baseline sRAGE and mortality.

Results

during 6 years of follow-up 101 participants died (50 frail and 51 non-frail). Frail individuals who died had significantly higher sRAGE levels than those who survived (median [IQR]: 1563 [1015-2248] vs 1184 [870-1657] pg/ml, P = 0.006), whilst no differences were observed in the non-frail group (1262 [1056-1554] vs 1186 [919-1551] pg/ml, P = 0.19). Among frail individuals higher sRAGE levels were associated with an increased risk of death after adjustment for relevant covariates (HR = 2.72 per unit increment in ln-sRAGE, 95%CI 1.48-4.99, P = 0.001). In contrast, in non-frail individuals sRAGE showed no association with mortality. Survival curves demonstrated that among frail individuals the incidence of death was significantly higher in the top sRAGE quartile compared to the three lower quartiles (P = 0.002). Area under the ROC curve analysis demonstrated that for frail individuals, inclusion of sRAGE in the hazard model increased its predictive accuracy by ~3%.

Conclusions

sRAGE is an independent predictor of mortality among frail individuals. Determination of sRAGE in frail subjects could be useful for prognostic assessment and treatment stratification.
Diagnosing Covariate Balance Across Levels of Right-Censoring Before and After Application of Inverse-Probability-of-Censoring Weights
Authors: Jackson John W
Published: May 2019

Covariate balance is a central concept in the potential outcomes literature. With selected populations or missing data, balance across treatment groups can be insufficient for estimating marginal treatment effects. Recently, a framework for using covariate balance to describe measured confounding and selection bias for time-varying and other multivariate exposures in the presence of right-censoring has been proposed. Here, we revisit this framework to consider balance across levels of right-censoring over time in more depth. Specifically, we develop measures of covariate balance that can describe what is known as “dependent censoring” in the literature, along with its associated selection bias, under multiple mechanisms for right censoring. Such measures are interesting because they substantively describe the evolution of dependent censoring mechanisms. Furthermore, we provide weighted versions that can depict how well such dependent censoring has been eliminated when inverse-probability-of-censoring weights are applied. These results provide a conceptually grounded way to inspect covariate balance across levels of right-censoring as a validity check. As a motivating example, we applied these measures to a study of hypothetical “static” and “dynamic” treatment protocols in a sequential multiple-assignment randomized trial of antipsychotics with high dropout rates.
Platelet-Rich Plasma and Stem Cells for Hair Growth: A Review of the Literature
Authors: Semsarzadeh Nina , Khetarpal Shilpi
Published: May 2019

The prevalence of hair loss, its psychological consequences, and historically subpar treatments present a unique challenge to the physician. The current Food and Drug Administration–approved treatments for hair loss are plagued by ineffectiveness, noncompliance, and adverse effects. Recent advances in our understanding of hair physiology have fueled the development of more efficacious, minimally invasive, and safer treatment options for hair restoration including plasma-rich protein and stem cell therapy. Platelet-rich plasma, the autologous preparation of concentrated platelets in plasma, when injected into the scalp of patients with both androgenetic alopecia (AGA) and alopecia areata (AA), has been shown to increase hair count and density. The clinical findings have been supported by histologic evaluation of the scalp skin. These findings have been recapitulated in numerous randomized controlled trials. Stem cell therapy, although newer in its application in hair restoration, has also been effective for treating both AGA and AA. The isolation techniques for stem cells are varied, but regardless have shown promising results in early prospective and retrospective studies.
ExpansionHunter: a sequence-graph-based tool to analyze variation in short tandem repeat regions
Authors: Dolzhenko Egor , Deshpande Viraj , Schlesinger Felix , Krusche Peter , Petrovski Roman , Chen Sai , Emig-Agius Dorothea , Gross Andrew , Narzisi Giuseppe , Bowman Brett , Scheffler Konrad , van Vugt Joke J F A , French Courtney , Sanchis-Juan Alba , Ibáñez Kristina , Tucci Arianna , Lajoie Bryan R , Veldink Jan H , Raymond F Lucy , Taft Ryan J , Bentley David R , Eberle Michael A
Published: May 2019

We describe a novel computational method for genotyping repeats using sequence graphs. This method addresses the long-standing need to accurately genotype medically important loci containing repeats adjacent to other variants or imperfect DNA repeats such as polyalanine repeats. Here we introduce a new version of our repeat genotyping software, ExpansionHunter, that uses this method to perform targeted genotyping of a broad class of such loci.

Availability and implementation

ExpansionHunter is implemented in C++ and is available under the Apache License Version 2.0. The source code, documentation, and Linux/macOS binaries are available at https://github.com/Illumina/ExpansionHunter/.

Supplementary information

Supplementary data are available at Bioinformatics online.
Plasma or serum? A qualitative study on rodents and humans using high-throughput microRNA sequencing for circulating biomarkers
Authors: Dufourd Thibault , Robil Noémie , Mallet David , Carcenac Carole , Boulet Sabrina , Brishoual Sonia , Rabois Emilie , Houeto Jean-Luc , de la Grange Pierre , Carnicella Sebastien
Published: May 2019

microRNAs are small non-coding RNAs gaining interest for their potential roles as reliable biomarkers for the diagnosis and therapeutics of numerous pathologies, ranging from cancer to neurodegenerative or psychiatric disorders. Indeed, microRNAs are present in various accessible biofluids, including peripheral blood, and specific dysregulation of their expression may be associated with these different pathological conditions. microRNAs can be isolated from plasma or serum for sequencing with commercial kits. However, these two biofluids might exhibit some differences in their microRNA contents, due notably to the coagulation process occurring during serum collection. It remains unclear from previous studies and commercial recommendations which blood fraction is preferable. Because of the small amount of circulating microRNAs in a given blood volume, this question appears crucial for qualitative and quantitative optimization of microRNA profiling, especially in animal models used for investigating the pathophysiological relevancy of this approach. We therefore evaluated the efficiency of RNA isolation and microRNA levels from plasma and sera isolated from rats and humans, with a widely used extraction kit (QIAGEN miRNeasy), and assessed microRNA quality and quantity with high-throughput sequencing. Fewer reads with length corresponding to non-miRNAs sequences were observed in plasma than in serum, both from rats and humans. Moreover, rat plasma produced twice as many aligned reads compared to sera, as well as more aligned reads corresponding to microRNAs (84.6% against 38.7%), differences that were not find in human samples. Our results, therefore, clearly indicate that plasma should be preferred for miRNA investigations, particularly for translational studies.
Antiretroviral Therapy Reduces T-cell Activation and Immune Exhaustion Markers in Human Immunodeficiency Virus Controllers
Authors: Li Jonathan Z , Segal Florencia P , Bosch Ronald J , Lalama Christina M , Roberts-Toler Carla , Delagreverie Heloise , Getz Rachel , Garcia-Broncano Pilar , Kinslow Jennifer , Tressler Randall , Van Dam Cornelius N , Keefer Michael , Carrington Mary , Lichterfeld Mathias , Kuritzkes Daniel , Yu Xu G , Landay Alan , Sax Paul E ,   AIDS Clinical Trials Group Study A5308 Team
Published: May 2019

Background

Despite low plasma human immunodeficiency virus (HIV) RNA, HIV controllers have evidence of viral replication and elevated inflammation. We assessed the effect of antiretroviral therapy (ART) on HIV suppression, immune activation, and quality of life (QoL).

Methods

A5308 was a prospective, open-label study of rilpivirine/emtricitabine/tenofovir disoproxil fumarate in ART-naive HIV controllers (N = 35), defined as having HIV RNA <500 copies/mL for ≥12 months. The primary outcome measured change in %CD38+HLA-DR+ CD8+ T cells. Residual plasma viremia was measured using the integrase single-copy assay. QoL was measured using the EQ-5D questionnaire. Outcomes were evaluated using repeated measures general estimating equations models.

Results

Before ART, HIV controllers with undetectable residual viremia <0.6 HIV-1 RNA copies/mL had higher CD4+ counts and lower levels of T-cell activation than those with detectable residual viremia. ART use was effective in further increasing the proportion of individuals with undetectable residual viremia (pre-ART vs after 24–48 weeks of ART: 19% vs 94%, P < .001). Significant declines were observed in the %CD38+HLA-DR+CD8+ T cells at 24–48 (−4.0%, P = .001) and 72–96 (−7.2%, P < .001) weeks after ART initiation. ART use resulted in decreases of several cellular markers of immune exhaustion and in a modest but significant improvement in self-reported QoL. There were no significant changes in CD4+ counts or HIV DNA.

Conclusions

ART in HIV controllers reduces T-cell activation and improves markers of immune exhaustion. These results support the possible clinical benefits of ART in this population.
De-escalation of IBD Therapy: When, Who, and How?
Authors: Waljee Akbar K , Chaisidhivej Natapat , Saini Sameer D , Higgins Peter D R
Published: May 2019

When patients with inflammatory bowel disease reach clinical remission with biologic therapy, a question that often comes up is, “when can I stop my biologic medication?” This is a question fraught with challenges for both physicians and patients. For physicians, there are valid concerns that stepping down from a successful therapy will lead to relapse and disease exacerbation, and that stepping down could lead to anti-biologic antibodies. For patients, the question is often driven by concerns about long-term side effects and costs of biologics. This review provides an overview of the rationale for, and risks of, withdrawal of IBD therapy. Selected studies have shown how to identify subsets of patients in whom de-escalation can be performed with low risk of relapse. Practical guidance on when and how to de-escalate IBD therapy is provided.