bluuebunny/crossref_metadata_2025 huggingface dataset:
MT2A is an early predictive biomarker of response to chemotherapy and a potential therapeutic target in osteosarcoma
Authors: Mangelinck Adèle , da Costa Maria Eugénia Marques , Stefanovska Bojana , Bawa Olivia , Polrot Mélanie , Gaspar Nathalie , Fromigué Olivia
Published: August 2019

Osteosarcoma is the most prevalent primary bone malignancy in children and young adults. Resistance to chemotherapy remains a key challenge for effective treatment of patients with osteosarcoma. The aim of the present study was to investigate the preventive role of metallothionein-2A (MT2A) in response to cytotoxic effects of chemotherapy. A panel of human and murine osteosarcoma cell lines, modified for MT2A were evaluated for cell viability, and motility (wound healing assay). Cell-derived xenograft models were established in mice. FFPE tumour samples were assessed by IHC. In vitro experiments indicated a positive correlation between half-maximal inhibitory concentration (IC50) for drugs in clinical practice, and MT2A mRNA level. This reinforced our previously reported correlation between MT2A mRNA level in tumour samples at diagnosis and overall survival in patients with osteosarcoma. In addition, MT2A/MT2 silencing using shRNA strategy led to a marked reduction of IC50 values and to enhanced cytotoxic effect of chemotherapy on primary tumour. Our results show that MT2A level could be used as a predictive biomarker of resistance to chemotherapy, and provide with preclinical rational for MT2A targeting as a therapeutic strategy for enhancing anti-tumour treatment of innate chemo-resistant osteosarcoma cells.
GSK3-CRMP2 signaling mediates axonal regeneration induced by Pten knockout
Authors: Leibinger Marco , Hilla Alexander M. , Andreadaki Anastasia , Fischer Dietmar
Published: August 2019

Knockout of phosphatase and tensin homolog (PTEN−/−) is neuroprotective and promotes axon regeneration in mature neurons. Elevation of mTOR activity in injured neurons has been proposed as the primary underlying mechanism. Here we demonstrate that PTEN−/− also abrogates the inhibitory activity of GSK3 on collapsin response mediator protein 2 (CRMP2) in retinal ganglion cell (RGC) axons. Moreover, maintenance of GSK3 activity in Gsk3S/A knockin mice significantly compromised PTEN−/−-mediated optic nerve regeneration as well as the activity of CRMP2, and to a lesser extent, mTOR. These GSK3S/A mediated negative effects on regeneration were rescued by viral expression of constitutively active CRMP2T/A, despite decreased mTOR activation. Gsk3S/A knockin or CRMP2 inhibition also decreased PTEN−/− mediated neurite growth of RGCs in culture and disinhibition towards CNS myelin. Thus, the GSK3/CRMP2 pathway is essential for PTEN−/− mediated axon regeneration. These new mechanistic insights may help to find novel strategies to promote axon regeneration.
Ultrasensitive electrochemical detection of ochratoxin A based on signal amplification by one-pot synthesized flower-like PEDOT–AuNFs supported on a graphene oxide sponge
Authors: Wang Pengxiang , Wang Luyan , Ding Mei , Pei Meishan , Guo Wenjuan
Published: August 2019

An ultrasensitive electrochemical aptasensor without additional signal amplifiers was designed to detect OTA, and it was based on flower-like PEDOT–AuNFs supported on GOS.
Multidrug resistant tumors-aimed theranostics on the basis of strong electrostatic attraction between resistant cells and nanomaterials
Authors: Liu Shuwei , Wang Lu , Li Shuyao , Meng Xuya , Sun Bin , Zhang Xue , Zhang Lening , Liu Yi , Lin Min , Zhang Hao , Yang Bai
Published: August 2019

The gene expression of resistant cells usually raises the negative potential of cell membranes. Utilizing the strong electrostatic attraction of resistant cells with nanomaterials, multidrug resistance tumors-aimed theranostics is demonstrated.
A halogen ion-selective phosphorescence turn-on probe based on induction of Pt–Pt interactions
Authors: Yang Jing , Sun Lili , Hao Liang , Yang Gang-Gang , Zou Zhi-Cong , Cao Qian , Ji Liang-Nian , Mao Zong-Wan
Published: August 2019

A halogen ion induced self-assembly of square-planar platinum complexes has been, for the first time, observed and applied as a turn-on phosphorescent probe for Cl−.
Covalent organic nanospheres: facile preparation and application in high-resolution gas chromatographic separation
Authors: Chen Jia , Huang Yanni , Wei Xin , Lei Xiaoqiang , Zhao Liang , Guan Ming , Qiu Hongdeng
Published: August 2019

A facile and rapid room-temperature solution-phase strategy was used to fabricate covalent organic nanospheres with uniform morphology and outstanding thermal/solvent stability for GC separation.
Inverting the reactivity of troponoid systems in enantioselective higher-order cycloaddition
Authors: Frankowski Sebastian , Skrzyńska Anna , Albrecht Łukasz
Published: August 2019

The first enantioselective higher-order cycloaddition involving a tropone derivative that acts as an electron-rich 8π-component is described.
Synthesis of Ag2O decorated hierarchical TiO2 templated by double comb copolymers for efficient solar water splitting
Authors: Choi Gyo Hun , Lim Seung Man , Moon Juyoung , Lim Jeong Min , Baek Uoon Chul , Park Jung Tae
Published: August 2019

Preparation of Ag2O decorated hierarchical TiO2 templated using a double comb copolymer.
Formation of α-helical and β-sheet structures in membrane-bound human IAPP monomer and the resulting membrane deformation
Authors: Qiao Qin , Wei Guanghong , Yao Demin , Song Zhijian
Published: August 2019

Upon adsorption on membrane, human IAPP monomer takes conformational changes from coils to α-helices and β-sheets. The helices inserted and β on surface cause different types of membrane deformation, implying two distinct aggregation mechanisms.
Ferroelectric nanocomposite networks with high energy storage capacitance and low ferroelectric loss by designing a hierarchical interface architecture
Authors: Chen Yingxin , Yue Yifeng , Liu Jie , Shu Jie , Liu Aiping , Chu Baojin , Xu Minhui , Xu Weizhong , Chen Tong , Zhang Jian , Shen Qun-Dong
Published: August 2019

Hierarchical interfaces were successfully established in ferroelectric nanocomposite networks, resulting in high energy density and low loss for capacitor applications.
Identification of the key steps in the self-assembly of homogeneous gold metal nanoparticles produced using inverse micelles
Authors: Decarolis Donato , Odarchenko Yaroslav , Herbert Jennifer J. , Qiu Chengwu , Longo Alessandro , Beale Andrew M.
Published: August 2019

The self-assembly of gold nanoparticles (Au NPs) using polymer-encapsulated inverse micelles was studied using a set of advanced X-ray techniques (i.e. XAFS, SAXS) in addition to DLS, UV-vis spectroscopy and TEM.
Two-level stochastic search of low-energy conformers for molecular spectroscopy: implementation and validation of MM and QM models
Authors: Chandramouli Balasubramanian , Del Galdo Sara , Fusè Marco , Barone Vincenzo , Mancini Giordano
Published: August 2019

The search for stationary points in the molecular potential energy surfaces (PES) is a problem of increasing relevance in molecular sciences especially for large, flexible systems featuring several large-amplitude internal motions.
Synthesis, characterization and catalytic activity of novel ruthenium complexes bearing NNN click based ligands
Authors: Sole Roberto , Bortoluzzi Marco , Spannenberg Anke , Tin Sergey , Beghetto Valentina , de Vries Johannes G.
Published: August 2019

New ruthenium complexes based on click-synthesized triazole-containing NNN ligands were successfully used for the hydrogenation of aldehydes and ketones.
Two microporous CoII-MOFs with dual active sites for highly selective adsorption of CO2/CH4 and CO2/N2
Authors: Ma Hui-Yan , Zhang Yong-Zheng , Yan Hui , Zhang Wen-Jie , Li Yun-Wu , Wang Su-Na , Li Da-Cheng , Dou Jian-Min , Li Jian-Rong
Published: August 2019

Two microporous CoII-MOFs exhibit highly CO2/CH4 and CO2/N2 selective adsorption owing to abundant dual active sites. GCMC theoretical simulations further verify the experimental results.
Synthesis, characterization, and photoluminescence properties of three two-dimensional lanthanide-containing Dawson-type polyoxometalates
Authors: Wu Hechen , Zhi Minna , Chen Chunli , Zhu Yanhong , Ma Pengtao , Wang Jingping , Niu Jingyang
Published: August 2019

Three isostructural lanthanide-containing polyoxometalates with 2D network architectures were successfully obtained under hydrothermal conditions.
NH4V4O10/rGO Composite as a high-performance electrode material for hybrid capacitive deionization
Authors: Li Chengxu , Wang Shiyong , Wang Gang , Wang Shuaifeng , Che Xiaoping , Li Duanzheng , Qiu Jieshan
Published: August 2019

Sodium ions in an NH4V4O10/rGO CDI cell can be reversibly inserted into NH4V4O10.
Effects of grape products on blood lipids: a systematic review and dose–response meta-analysis of randomized controlled trials
Authors: Ghaedi Ehsan , Moradi Sajjad , Aslani Zahra , Kord-Varkaneh Hamed , Miraghajani Maryam , Mohammadi Hamed
Published: August 2019

Grape products through several plausible mechanisms-of-action are reported to improve lipid profile. The present systematic review revealed that grape product supplementation might have a positive effect on achieving a lipid profile target.
Correlative microscopy of freeze-dried cells and studies on intracellular calcium stores with imaging secondary ion mass spectrometry (SIMS)
Authors: Chandra Subhash
Published: August 2019

Secondary ion mass spectrometry (SIMS)-based imaging techniques have become effective tools for studies of elements and molecules in biological samples.
Microfluidic SlipChip device for multistep multiplexed biochemistry on a nanoliter scale
Authors: Zhukov Dmitriy V. , Khorosheva Eugenia M. , Khazaei Tahmineh , Du Wenbin , Selck David A. , Shishkin Alexander A. , Ismagilov Rustem F.
Published: August 2019

Using interfacial energy between carrier and sample phases, this manually operated device accurately meters and merges nanoliter scale reagent droplets repeatedly.
Processing code-multiplexed Coulter signals via deep convolutional neural networks
Authors: Wang Ningquan , Liu Ruxiu , Asmare Norh , Chu Chia-Heng , Sarioglu A. Fatih
Published: August 2019

Deep learning-enhanced Coulter counter networks for electronic tracking of particles in microfluidic devices.
Novel electro-magnetophoretic separation method for the highly sensitive detection of analytes
Authors: Giovannini Giorgia , De Angelis Francesco
Published: August 2019

We present a method to improve the detection limits of assays based on magnetic particles based on electro-magnetophoretic separation. It can be used with existing protocols to lower their detection limits by removing the excess of magnetic NP.
Controlling exciton transport in monolayer MoSe2 by dielectric screening
Authors: Hao Shengcai , Bellus Matthew Z. , He Dawei , Wang Yongsheng , Zhao Hui
Published: August 2019

Exciton transport in a two-dimensional semiconductor is controlled by placing a top dielectric layer.
Nanostructured g-C3N4/AgI composites assembled by AgI nanoparticles-decorated g-C3N4 nanosheets for effective and mild photooxidation reaction
Authors: Cheng Ying , He Lingling , Xia Guangqiang , Ren Chunguang , Wang Zhonghua
Published: August 2019

AgI nanoparticles-decorated g-C3N4 nanosheets with enhanced visible-light photocatalytic activity for the mild photooxidation of 1,4-DHP into its pyridine derivatives.
Ionic liquid-assisted synthesis of dihydropyrimidin(thi)one Biginelli adducts and investigation of their mechanism of urease inhibition
Authors: Braga Taniris Cafiero , Silva Thamara Ferreira , Maciel Thamilla Maria Silva , da Silva Edjan Carlos Dantas , da Silva-Júnior Edeildo Ferreira , Modolo Luzia Valentina , Figueiredo Isis Martins , Santos Josué Carinhanha Caldas , de Aquino Thiago Mendonça , de Fátima Ângelo
Published: August 2019

Three out of twenty-six synthesized Biginelli adducts were identified as potent competitive urease inhibitors.
Inception of molybdate as a “pore forming additive” to enhance the bifunctional electrocatalytic activity of nickel and cobalt based mixed hydroxides for overall water splitting
Authors: Ganguli Sagar , Ghosh Sourav , Das Soumik , Mahalingam Venkataramanan
Published: August 2019

Understanding the effect of molybdate incorporation on the structure, morphology, porosity, surface area and etching-induced enhanced electrocatalytic water splitting of low-cost transition metal hydroxides grown on inexpensive copper substrate.
Vertical ferroelectric switching by in-plane sliding of two-dimensional bilayer WTe2
Authors: Liu Xingen , Yang Yali , Hu Tao , Zhao Guodong , Chen Chen , Ren Wei
Published: August 2019

Vertical ferroelectric switching by in-plane sliding of two-dimensional bilayer WTe2, leading to the spin texture and spin-FET design with strain tunability.
Suppression of coffee-ring effect via periodic oscillation of substrate for ultra-sensitive enrichment towards surface-enhanced Raman scattering
Authors: Ji Bing , Zhang Lingjun , Li Mingzhong , Wang Shuangpeng , Law Man-Kay , Huang Yingzhou , Wen Weijia , Zhou Bingpu
Published: August 2019

A novel and simple strategy with the integration of a magnetically functional membrane and reciprocating magnetic field for the improvement of the SERS uniformity and property towards the highly reliable and ultra-sensitive detection is reported.
β-Sulfonylation of α-bromoenals enabled by N-heterocyclic carbene catalysis
Authors: Jin Shiyi , Fang Shuaishuai , Ma Rui , Liang Zheng , Xu Ye , Lu Tao , Du Ding
Published: August 2019

An N-heterocyclic carbene (NHC)-catalyzed three-component tandem β-sulfonylation/esterification of α-bromoenals was developed.
Spermidine enhanced resistance of Chlorella to high levels of CO2 and light intensity for improving photosynthetic growth rate
Authors: Zhang Xiangdong , Cheng Jun , Lu Hongxiang , Chu Feifei , Xu Junchen , Wang Xuebin , Cen Kefa
Published: August 2019

Spermidine enhanced resistance of Chlorella to high levels of CO2 and light intensity.
Deposition kinetics of bi- and tridisperse colloidal suspensions in microchannels under the van der Waals regime
Authors: Cejas Cesare M. , Maini Lucrezia , Monti Fabrice , Tabeling Patrick
Published: August 2019

Particle–particle interactions can be neglected in the deposition of non-monodisperse suspensions inside confined microchannel walls during early times of deposition.
Enhanced elasticity in poly(acrylic acid) gelsviasynthesis in the presence of high concentrations of select salts
Authors: Walker Anne , Vratsanos Maria , Kozawa Susan , Askew Tiara , Hemmendinger Karina , McGrail Brendan , Bedford Nicholas , Wnek Gary
Published: August 2019

Poly(acrylic acid) gels synthesizedviafree-radical polymerization of acrylic acid and high molarities of salt show properties quite different from such gels synthesized without salt. Enhanced properties include increased extensibility and modulus.
Generic packing motifs in vapor-deposited glasses of organic semiconductors
Authors: Bagchi Kushal , Gujral Ankit , Toney M. F. , Ediger M. D.
Published: August 2019

Organic semiconductors with an anisotropic shape exhibit a surprisingly similar tendency towards face-on packing when deposited at ∼0.75–0.8Tg.
Rational design of tailored porous carbon-based materials for CO2 capture
Authors: Zhang Zhen , Cano Zachary Paul , Luo Dan , Dou Haozhen , Yu Aiping , Chen Zhongwei
Published: August 2019

This review summarizes the up-to-date advances in porous carbons with tailored pore texture and surface chemistry toward efficient CO2 capture.
A hollow CuS nanocube cathode for rechargeable Mg batteries: effect of the structure on the performance
Authors: Shen Jingwei , Zhang Yujie , Chen Dong , Li Xue , Chen Zhongxue , Cao Shun-an , Li Ting , Xu Fei
Published: August 2019

Hollow CuS nanocubes are used as rechargeable Mg battery cathodes with fast solid-state Mg2+ ion diffusion kinetics.
Molten salts promoting the “controlled carbonization” of waste polyesters into hierarchically porous carbon for high-performance solar steam evaporation
Authors: Zhang Boyi , Song Changyuan , Liu Chang , Min Jiakang , Azadmanjiri Jalal , Ni Yunxia , Niu Ran , Gong Jiang , Zhao Qiang , Tang Tao
Published: August 2019

Hierarchically porous carbon is synthesized from PET using ZnCl2/NaCl, exhibiting a high evaporation rate (1.68 kg m−2 h−1) and energy conversion efficiency (97%).
K+ pre-intercalated manganese dioxide with enhanced Zn2+ diffusion for high rate and durable aqueous zinc-ion batteries
Authors: Liu Guoxue , Huang Huawen , Bi Ran , Xiao Xue , Ma Tianyi , Zhang Lei
Published: August 2019

α-K0.19MnO2 nanotubes with high K+ content as cathodes for zinc-ion batteries show high capacity, excellent rate capability and cycling stability.
Cathodoluminescence of a 2 inch ultraviolet-light-source tube based on the integration of AlGaN materials and carbon nanotube field emitters
Authors: Tawfik Wael Z. , Kumar C. M. Manoj , Park Joonmo , Shim Sang Kyun , Lee Hansung , Lee Jaehwi , Han Jong Hun , Ryu Sang-Wan , Lee Naesung , Lee June Key
Published: August 2019

High efficiency and mass-scale production ultraviolet (UV) light sources have become a basic requirement for various applications, and as such have attracted considerable technological interest.
Defect-induced broadband photodetection of layered γ-In2Se3 nanofilm and its application in near infrared image sensors
Authors: Wu Chun-Yan , Kang Jing-Wei , Wang Bin , Zhu Hui-Nan , Li Zhong-Jun , Chen Shi-Rong , Wang Li , Yang Wen-Hua , Xie Chao , Luo Lin-Bao
Published: August 2019

We report on the synthesis of layered γ-In2Se3 nanofilm for broadband photodetector and near infrared light image sensing applications.
Pair‐based sink relocation and route adjustment in mobile sink WSN integrated IoT
Authors: Thiruchelvi A. , Karthikeyan N.
Published: August 2019

In recent years, Wireless Sensor Network (WSN) have expanded as foundation infrastructure for Internet of Things (IoT). However, integrating WSN into IoT is a challenging task due to its poor network lifetime and high energy consumption. To address these shortcomings, our proposed work performs five sequential processes: Initially, we split the network region into multiple partitions using Quad Tree combined Binary Tree (QTcBT) partitioning algorithm. We carry out Weight based Cluster Head Selection (WCHS) method to select a cluster head in each partition. A novel Pair based Sink Relocation Scheme (PSRS) is proposed to relocate the sink node which effectually increases the network lifetime. We execute Destination Oriented Directed Acyclic Graph (DODAG) based route adjustment that adjusts route by considering three rules. Finally, we perform Type 2 Fuzzy based Adaptive MAC Scheduling (T2FAMS) that is handled by the cluster head. At last, we evaluate the performance of our proposed work in terms of metrics including Energy consumption, End to End delay, Network lifetime, Delivery success ratio and Number of nodes alive. From the evaluation, we conclude that our work reduces energy consumption up to 20% and improves network lifetime up to 30% compared to the existing QDVGDD and GR methods.
Retinal vessel segmentation approach based on corrected morphological transformation and fractal dimension
Authors: Wang Weihua , Wang Weiqing , Hu Zhangping
Published: August 2019

The morphological structure of retinal vessels plays an important role in analysing and diagnosing fundus disease. In this study, an unsupervised automatic segmentation method for retinal blood vessels with corrected morphological transformation and fractal dimension is proposed. To enhance the contrast between retinal vessels and background in a fundus image, the morphological operator with linear structural elements is used; to remove the lesion and its light reflection, a compensation method is proposed; to extract the objects from a grey image, the multi‐threshold approach is applied; to recognise the blood vessels and noise from the fundus image, a new method based on fractal dimension is presented. The new approach is tested in detail on three public databases STARE, DRIVE and HRF. Experimental results show that the segmentation algorithm is better than other existing unsupervised automatic segmentation algorithms, and the new approach is robust.
Two‐dimensional FFT and two‐dimensional CA‐CFAR based on ZYNQ
Authors: Yuan Yunneng , Li Weihua , Sun Zhongsheng , Zhang Yuxi , Xiang Hong
Published: August 2019

Here, two‐dimensional FFT and two‐dimensional CA‐CFAR are combined to process echoes of LFMCW radar based on ZYNQ, which are implemented on hardware, using parallel feature of ZYNQ to improve processing speed. With the high accurate information of two‐dimensional FFT and two‐dimensional CA‐CFAR, the velocity and range information of echo signal is extracted. The coupling problem of velocity and range is solved and the situation of alarm leakage in multi‐target is avoided. First, the basic form of the LFMCW signal is introduced. Then, the implementation flow of 2D‐FFT and 2D CA‐CFAR is described in detail. At last, the conclusion is given by analysing the results of the tested data processed by ZYNQ and is compared with 1D‐FFT combined with 1D‐CFAR.
Experimental measurements of radar signatures of large wind turbine
Authors: Fioranelli Francesco , Patel Jarez , Horne Colin , Palamà Riccardo , Griffiths Hugh , Danoon Laith , Brown Anthony
Published: August 2019

This study presents preliminary results on the signature of a large offshore wind turbine collected using an active S‐band radar. The intensity fluctuations of this clutter signal in the range and Doppler domain are characterised, looking at their evolution over time, statistics, and spread in the Doppler domain. The polarisation impact on the signatures is also discussed.
Underdetermined direction‐of‐arrival estimation using super nested array
Authors: Jiang Zheng‐Ming , Zhang Peichang , Huang Lei , Zhang Jihong
Published: August 2019

Among various sparse‐arrays, super nested array (SNA) is found to be more attractive because it can achieve large degrees‐of‐freedom (DOFs) and alleviate the mutual coupling. This article address the problem of direction‐of‐arrival (DOA) estimation under underdetermined conditions based on the SNA. To tackle the underdetermined method, vectorising covariance matrix to obtain the large virtual array is developed to enlarge the DOFs and avoid phase ambiguity. However, the rank of vectorised covariance matrix equals to one, which fail to yield DOAs estimates, when multiple signals applied to the array. In order to circumvent this issue, the article first exploits the selective matrix to transform the disorder virtual array to an ordered one and remove the redundant element of the virtual array. Then reconstruct covariance matrix to overcome the low‐rank problem. Exploiting the structure of SNA, the authors’ proposed method can achieve more target than conventional methods and reduce the mutual coupling when the number of source is larger than the number of antennas. Simulation results demonstrate the effectiveness of the authors’ proposed method.
SAR high‐resolution imaging from missing raw data using StOMP
Authors: Qian Yulei , Zhu Daiyin , Yu Xiang
Published: August 2019

SAR raw data missing occurs when radar is interrupted for various reasons. In order to deal with this problem, a method is proposed to focus the missing SAR raw data via stage‐wise orthogonal matching pursuit (StOMP). A reference function in time domain is designed for the missing raw data. After matched with the reference function, the energy of missing raw data is concentrated in two‐dimensional frequency domain. Then, StOMP algorithm is available to recover the matched raw data in two‐dimensional frequency domain. The recovered raw data is available to be processed with traditional SAR imaging algorithms. The Omega‐K algorithm is chosen to deal with the recovered raw data in experiments. Point target and area target simulations are carried out to validate the effectiveness of the proposed method for azimuth missing SAR raw data. The data missing rate is 50% in both point and area target simulation. The resolution of point targets can reach 0.3 m in both range and azimuth direction.
Inner rocky super-Earth formation: distinguishing the formation pathways in viscously heated and passive discs
Authors: Bitsch Bertram
Published: August 2019

Observations have revealed that super-Earths (planets up to 10 Earth masses) are the most abundant type of planets in the inner systems. Their formation is strongly linked to the structure of the protoplanetary disc, which determines growth and migration. In the pebble accretion scenario, planets grow to the pebble isolation mass, at which the planet carves a small gap in the gas disc halting the pebble flux and thus its growth. The pebble isolation mass scales with the disc’s aspect ratio, which directly depends on the heating source of the protoplanetary disc. I compare the growth of super-Earths in viscously heated discs, where viscous heating dissipates within the first million years, and discs purely heated by the central star with super-Earth observations from the Kepler mission. This allows two formation pathways of super-Earths to be distinguished in the inner systems within this framework. Planets growing within 1 Myr in the viscously heated inner disc reach pebble isolation masses that correspond directly to the inferred masses of the Kepler observations for systems that feature planets in resonance or not in resonance. However, to explain the period ratio distribution of Kepler planets – where most Kepler planet pairs are not in mean motion resonance configurations – a fraction of these resonant chains has to be broken. In case the planets are born early in a viscously heated disc, these resonant chains thus have to be broken without planetary mergers, for example through the magnetic rebound effect, and the final system architecture should feature low mutual inclinations. If super-Earths form either late or in purely passive discs, the pebble isolation mass is too small (around 2–3 Earth masses) to explain the Kepler observations, implying that planetary mergers have to play a significant role in determining the final system architecture. Resonant planetary systems thus have to experience mergers already during the gas disc phase, so the planets can get trapped in resonance after reaching 5–10 Earth masses. In case instabilities are dominating the system architecture, the systems should not be flat, but feature mutually inclined orbits. This implies that future observations of planetary systems with radial velocities (RV) and transits (for example through the Transiting Exoplanet Survey Satellite (TESS) and its follow up RV surveys) could distinguish between these two formation channels of super-Earth and thus constrain planet formation theories.
Solar Hα features with hot onsets
Authors: Rutten Robert J. , Rouppe van der Voort Luc H. M. , De Pontieu Bart
Published: August 2019

Even in quiet areas underneath coronal holes the solar chromosphere contains ubiquitous heating events. They tend to be small scale and short lived, hence difficult to identify. Here we do not address their much-debated contribution to outer-atmosphere heating, but their aftermaths. We performed a statistical analysis of high-resolution observations in the Balmer Hα line to suggest that many slender dark Hα fibrils spreading out from network represent cooling gas that outlines tracks of preceding rapid type II spicule events or smaller similar but as yet unresolved heating agents in which the main gas constituent, hydrogen, ionizes at least partially. Subsequent recombination then causes dark Hα fibrils enhanced by nonequilibrium overopacity. We suggest that the extraordinary fibrilar appearance of the Hα chromosphere around network results from intermittent, frequent small-scale prior heating.
Sound of a nut rolling inside an elastic rubber balloon
Authors: Barral Amaury , Louis Quentin , Brochet Clément , André Julie , Guillen Anthony , Goh Fang , Prieto Angel , Guillet Thibault
Published: August 2019

This article studies the sound produced by nuts of different shapes swirling in an elastic rubber balloon. First, the sound is studied experimentally, both in terms of frequency and amplitude. Regarding the frequency components of the sound, we show that they can be divided into two main contributions – one due to the oscillations of the elastic membrane, the other due to the hits of the nut against the balloon – and present models to describe the frequency’s dependence on the main parameters of the system. We analysed the influence of several parameters such as the balloon’s geometry, the nut’s geometry and its mass.
Insights on heterogeneity in blinking mechanisms and non-ergodicity using sub-ensemble statistical analysis of single quantum-dots
Authors: Mukherjee Amitrajit , Ray Korak Kumar , Phadnis Chinmay , Layek Arunasish , Bera Soumya , Chowdhury Arindam
Published: August 2019

Photo-luminescence (P-L) intermittency (or blinking) in semiconductor nanocrystals (NCs), a phenomenon ubiquitous to single-emitters, is generally considered to be temporally random intensity fluctuations between “bright” (“On”) and “dark” (“Off”) states. However, individual quantum-dots (QDs) rarely exhibit such telegraphic signals, and yet, a vast majority of single-NC blinking data are analyzed using a single fixed threshold which generates binary trajectories. Furthermore, while blinking dynamics can vary dramatically over NCs in the ensemble, the extent of diversity in the exponents (mOn/Off) of single-particle On-/Off-time distributions (P(tOn/Off)), often used to validate mechanistic models of blinking, remains unclear due to a lack of statistically relevant data sets. Here, we subclassify an ensemble of QDs based on the emissivity of each emitter and subsequently compare the (sub)ensembles’ behaviors. To achieve this, we analyzed a large number (>1000) of blinking trajectories for a model system, Mn+2 doped ZnCdS QDs, which exhibits diverse blinking dynamics. An intensity histogram dependent thresholding method allowed us to construct distributions of relevant blinking parameters (such as mOn/Off). Interestingly, we find that single QD P(tOn/Off)s follow either truncated power law or power law, and their relative proportion varies over subpopulations. Our results reveal a remarkable variation in mOn/Off amongst as well as within subensembles, which implies multiple blinking mechanisms being operational amongst various QDs. We further show that the mOn/Off obtained via cumulative single-particle P(tOn/Off) is distinct from the weighted mean value of all single-particle mOn/Off, evidence for the lack of ergodicity. Thus, investigation and analyses of a large number of QDs, albeit for a limited time span of a few decades, are crucial to characterize the spatial heterogeneity in possible blinking mechanisms.
Capacitive silicon micro-electromechanical resonator for enhanced photoacoustic spectroscopy
Authors: Chamassi Kaim , Trzpil Wioletta , Arinero Richard , Rousseau Roman , Vicet Aurore , Bahriz Michael
Published: August 2019

Photoacoustic spectroscopy (PAS) has been increasingly applied to detect gas traces in many applications. Gas absorption is detected through the excitation of a mechanical transducer, actuated by the acoustic pressure generated after optical absorption. PAS is potentially the best method to achieve some selective, sensitive, compact, and reliable sensors. However, the main limitation comes from the use of some mechanical transducers which are not specifically designed for this application. Great interest for realizing efficient devices with specific characteristics led us to study microelectromechanical systems (MEMS). Silicon is the core material of this technology. It offers high performances in terms of quality factor and residual stress and is an attractive alternative to conventional acoustic transducers. MEMS are widely used as transducers, and electrostatic transduction is a well-established method. In this work, we describe mechanical resonators fabricated on a silicon-on-insulator (SOI) wafer to be used as acoustic transducers in PAS. The performances of the developed devices are strictly linked to their mechanical properties and viscous damping. Their sensitivity is evaluated through an experimental setup; we achieved to detect methane and ethylene using a distributed feedback (DFB) laser diode and a DFB-QCL (Quantum Cascade Laser) emitting at 1.6 μm and 11 μm, respectively. By demonstrating stable and reproducible detection, this work opens the way to a concept of compact gas sensors based on tunable diode laser absorption spectroscopy and capacitive silicon microelectromechanical resonators.
Decomposition of plasma kinetic entropy into position and velocity space and the use of kinetic entropy in particle-in-cell simulations
Authors: Liang Haoming , Cassak Paul A. , Servidio Sergio , Shay Michael A. , Drake James F. , Swisdak Marc , Argall Matt R. , Dorelli John C. , Scime Earl E. , Matthaeus William H. , Roytershteyn Vadim , Delzanno Gian Luca
Published: August 2019

We describe a systematic development of kinetic entropy as a diagnostic in fully kinetic particle-in-cell (PIC) simulations and use it to interpret plasma physics processes in heliospheric, planetary, and astrophysical systems. First, we calculate kinetic entropy in two forms—the “combinatorial” form related to the logarithm of the number of microstates per macrostate and the “continuous” form related to flnf, where f is the particle distribution function. We discuss the advantages and disadvantages of each and discuss subtleties about implementing them in PIC codes. Using collisionless PIC simulations that are two-dimensional in position space and three-dimensional in velocity space, we verify the implementation of the kinetic entropy diagnostics and discuss how to optimize numerical parameters to ensure accurate results. We show the total kinetic entropy is conserved to three percent in an optimized simulation of antiparallel magnetic reconnection. Kinetic entropy can be decomposed into a sum of a position space entropy and a velocity space entropy, and we use this to investigate the nature of kinetic entropy transport during collisionless reconnection. We find the velocity space entropy of both electrons and ions increases in time due to plasma heating during magnetic reconnection, while the position space entropy decreases due to plasma compression. This project uses collisionless simulations, so it cannot address physical dissipation mechanisms; nonetheless, the infrastructure developed here should be useful for studies of collisional or weakly collisional heliospheric, planetary, and astrophysical systems. Beyond reconnection, the diagnostic is expected to be applicable to plasma turbulence and collisionless shocks.
Quantum transport properties of monolayer graphene with antidot lattice
Authors: Wang Leizhi , Yin Ming , Zhong Bochen , Jaroszynski Jan , Mbamalu Godwin , Datta Timir
Published: August 2019

Quantum transport properties in monolayer graphene are sensitive to structural modifications. We find that the introduction of a hexagonal lattice of antidots has a wide impact on weak localization and Shubnikov-de Haas (SdH) oscillation of graphene. The antidot lattice reduces both phase coherence and intervalley scattering length. Remarkably, even with softened intervalley scattering, i.e., the phase-breaking time is shorter than intervalley scattering time, coherence between time reversed states remains adequate to retain weak localization, an offbeat and rarely reported occurrence. Whereas SdH oscillation is boosted by the antidot lattice, the amplitude of the SdH signal rises rapidly with the increasing antidot radius. But both effective mass and carrier density are reduced in a larger antidot lattice. A bandgap of ∼10 meV is opened. The antidot lattice is an effective dopant-free way to manipulate electronic properties in graphene.
Adsorption of 5-Fluorouracil on Au(111) and Cu(111) surfaces
Authors: Cassidy Andrew , Tsud Nataliya , Bercha Sofiia , Feyer Vitaliy , Prince Kevin C. , Plekan Oksana
Published: August 2019

The adsorption of 5-Fluorouracil (5FU) on Au(111) and Cu(111) surfaces as a function of molecular coverage and temperature has been studied, using x-ray photoelectron spectroscopy (XPS) and near-edge x-ray absorption fine structure (NEXAFS) spectroscopy. The nature of 5-Fluorouracil bonding with the two substrates is remarkably different. The Cu substrate forms a chemisorbed complex with 5-FU while the Au substrate shows only physisorption. NEXAFS data at the C, N and O K-edge show a strong angular dependence, indicating that 5-FU lies nearly parallel on the inert Au(111) surface, and at a steep angle on the Cu(111) surface. 5-FU is a biomolecule used for cancer treatment and the results are relevant for those using metal surfaces to prepare 5-FU for applications such as drug delivery.
Spallation of polycarbonate under plate impact loading
Authors: Ye S. J. , Chai H. W. , Xiao X. H. , Cai Y. , Yao X. H. , Luo S. N.
Published: August 2019

We investigate spallation of polycarbonate under plate impact loading. The Hugoniot equation of state up to ∼1.3GPa (corresponding to a peak particle velocity ∼380m/s) is obtained, and spall strength and corresponding strain rates are determined at peak shock stresses up to ∼2.4GPa (corresponding to a peak particle velocity ∼600m/s). With increasing shock strength, the transition from strain-hardening to softening at shock states occurs as a result of shock heating; spall strength remains approximately constant, followed by a rapid drop upon strain softening. Release/tensile melting occurs at higher impact velocities. Three-dimensional void configurations of the postmortem samples are obtained via X-ray computerized tomography. The small voids are flat and curved for low-speed shots but become ellipsoidal for high-speed shots, and their coalescence leads to different shapes likely due to different damage mechanisms.
Limitations of In2O3 as a transparent conducting oxide
Authors: Peelaers H. , Kioupakis E. , Van de Walle C. G.
Published: August 2019

Sn-doped In2O3 or ITO is the most widely used transparent conducting oxide. We use first-principles calculations to investigate the limitations to its transparency due to free-carrier absorption mediated by phonons or charged defects. We find that the main contribution to the phonon-assisted indirect absorption is due to emission (as opposed to absorption) of phonons, which explains why the process is relatively insensitive to temperature. The wavelength dependence of this indirect absorption process can be described by a power law. Indirect absorption mediated by charged defects or impurities is also unavoidable since doping is required to obtain conductivity. At high carrier concentrations, screening by the free carriers becomes important. We find that charged-impurity-assisted absorption becomes larger than phonon-assisted absorption for impurity concentrations above 1020 cm–3. The differences in the photon-energy dependence of the two processes can be explained by band structure effects.
Quasiparticle band structure and optical properties of rutile GeO2, an ultra-wide-band-gap semiconductor
Authors: Mengle Kelsey A. , Chae Sieun , Kioupakis Emmanouil
Published: August 2019

Rutile GeO2 is a visible and near-ultraviolet-transparent oxide that has not been explored for semiconducting applications in electronic and optoelectronic devices. We investigate the electronic and optical properties of rutile GeO2 with first-principles calculations based on density functional theory and many-body perturbation theory. Our band-structure calculations indicate a dipole-forbidden direct bandgap at Γ with an energy of 4.44 eV and effective masses equal to m∗e⊥=0.43m0, m∗e∥=0.23m0, m∗h⊥=1.28m0, and m∗h∥=1.74m0. In contrast to the self-trapped hole polarons by lattice distortions in other wide-bandgap oxides that reduce the hole mobility, holes in rutile GeO2 are delocalized due to their small effective mass. The first allowed optical transitions at Γ occur at 5.04 eV (E→⊥c→) and 6.65 eV (E→∥c→). We also evaluate the optical absorption coefficient and refractive index along both crystallographic directions. Our estimates for the exciton binding energies using the Bohr model are close to the reported experimental value. The ultrawide-bandgap and light carrier effective masses of rutile GeO2, coupled with its optical transparency in the visible and near UV, are promising for applications in UV-transparent conductors and solar-blind photodetectors.
Response of poly(methyl methacrylate) to shock-wave loading at elevated temperatures
Authors: Zaretsky E. B. , Kanel G. I.
Published: August 2019

The shock wave response of commercial poly(methyl methacrylate), PMMA, in the vicinity of its glass transition temperature (Tg = 110–120 °C) was studied in two series of impact experiments, the first of which was aimed at the variation of the PMMA spall strength with temperature. The purpose of the second series was the effect of temperature on the PMMA Hugoniot. It was found that the spall strength of PMMA experiences an abrupt twofold drop at ≈120 °C. The PMMA Hugoniot Us=C0+sup was found to be that of a virtually elastic solid with C0 close to the longitudinal speed of sound, cl, at room temperature and transformed above Tg into a viscous material with no shear strength and C0 close to the bulk speed of sound, cb.
An ultra-stable setup for measuring electrical and thermoelectrical properties of nanojunctions
Authors: Popp Matthias A. , Weber Heiko B.
Published: August 2019

We present a setup that is excellently suited to measure the electrical and thermoelectrical transport across single-molecule junctions at both room temperature and low temperatures. It employs a sandwich configuration of two silicon carbide chips each equipped with metallic electrodes. Upon compression with an external piezo/spring mechanism, fine-tuned displacement control is achieved such that ultrastable atomically thin nanojunctions can be established. As a consequence of its stability, the setup gives access to point-by-point comparisons of electrical and thermoelectrical transport across single-molecule contacts. As a first demonstration of the capabilities of our setup, we present experiments with gold-molecule-gold contacts. Investigating a large ensemble of nanojunctions, each fully characterized by current-voltage characteristics and thermovoltage, correlations between these quantities are uncovered which can be rationalized within the Landauer transport picture. When including characteristics with resonant features, the Seebeck coefficient adds the decisive parameter to fully describe datasets within a resonant tunneling model. The setup provides further potential of controlling additional parameters as it is optically fully transparent. It also allows for nearly arbitrary material combinations for electrode-nanoobject object-electrode nanojunctions.
Thinking outside the system: the integrated care experience in Queensland, Australia
Authors: Mundy Linda , Hewson Kaye
Published: August 2019

Health policy-makers are faced with a demand for health care that exceeds supply, driven in part by an ageing population and an increased prevalence of chronic disease. An integrated ‘people-centred’ model of care across primary, secondary and tertiary health care can strengthen the health system by streamlining services to improve the patient journey and outcomes. Integrated care offers an opportunity to reduce admissions and re-admissions to hospitals, reduce presentations to emergency departments and improve the capacity of outpatient clinics while delivering better outcomes to patients. Queensland’s $35 million Integrated Care Innovation Fund (ICIF) has provided seed funding to 24 projects covering a wide spectrum of chronic disease management and complex disease. Programs such as the ICIF offer an opportunity to provide a new approach to caring for vulnerable populations such as the frail and elderly; children with behavioural and developmental issues; children in out-of-home care; rural and remote populations; and people with mental health issues, whose care runs the risk of ‘falling through the cracks’ with conventional healthcare approaches.
Effects of wet season mineral nutrition on chital deer distribution in northern Queensland
Authors: Watter Kurt , Baxter Greg S. , Pople Tony , Murray Peter J.
Published: August 2019

Abstract ContextTo predict the success of an invasive species, it is important to understand the habitat factors that influence its distribution and abundance. In northern Queensland, chital deer (Axis axis) is an introduced ungulate that occupies specific areas over periods of several decades. AimsThe aim was to compare mineral concentrations in the soil and food plants of areas that chital occupy in high and low densities, and to assess mineral levels in blood sera. MethodsFaecal counts were used to identify areas of high and low chital density. Samples of soil and food plants were analysed from high- and low-density areas to determine the concentrations of 10 minerals from 32 collection sites. Laboratory examination was conducted on serum collected from 46 culled chital to evaluate mineral concentrations. Key resultsChital density varied markedly, with higher mineral concentrations found in soil and food plants in areas of high chital density compared with low-density locations. Average-ranked analyses indicated soil phosphorus levels were significantly (1.5×) higher in areas of high chital density, together with levels of Na (3.4×), Mg (2.3×), Mn (2.1×) and Fe (1.3×) in grasses that comprise more than 90% of the wet season (November to March) diet. Based on minimum requirements for ruminants, the concentrations of Na and Zn in grasses were suboptimal for chital. Serum Zn concentrations suggest a marginal deficiency in most of the animals sampled. ConclusionsMineral requirements of ungulates are such that deficiencies in availability of key nutrients may be sufficient to influence density and distribution. If there are deficiencies, the principal determinants of habitat selection are likely to be P in soil, and Na and Zn in food plants. Deficiencies of both Na and Zn in the diet may limit growth and reproductive output. Implications Mineral adequacy in the diet of chital may be a determinant of their current distribution and a predictor of the habitats they may successfully colonise in the future. Recognition of mineral nutrition as a habitat predictor may aid in the management of chital as a keystone species where it is native on the Indian subcontinent, and as an invasive species where it has become naturalised.
Iridescence in nematics: Photonic liquid crystals of nanoplates in absence of long-range periodicity
Authors: Zeng Minxiang , King Daniel , Huang Dali , Do Changwoo , Wang Ling , Chen Mingfeng , Lei Shijun , Lin Pengcheng , Chen Ying , Cheng Zhengdong
Published: August 2019

Significance

The striking colors of organisms, like butterflies, have sparked tremendous research interest in developing artificial photonic crystals with extraordinary optical properties. In most cases, the color of photonic crystals originates from the periodic microstructure that manipulates light through optical interference. Here, we report a photonic structure that does not rely on long-range periodic arrangements. Instead, such structural color comes from the nematic liquid crystals of nanodiscs as opposed to the conventional achiral nematic phases that are colorless under white light. This finding challenges the stereotypical design of photonic liquid crystals based mainly on periodically layered or helical structures. We expect that the concept of nematic photonic nanoparticles may open research opportunities for developing advanced photonic materials.
Antibody barriers to going viral
Authors: Burton Dennis R.
Published: August 2019

Antibody neutralization of a virus in vitro is often associated with protection against viral exposure in vivo, but the mechanisms operational in vivo are often unclear. By investigating a large number of antibodies, Earnest et al. (https://doi.org/10.1084/jem.20190736) show the importance of antibody effector function in neutralizing antibody protection against an emerging alphavirus in a mouse model.