bluuebunny/crossref_metadata_2025 huggingface dataset:
Yolk–shell nanostructures: synthesis, photocatalysis and interfacial charge dynamics
Authors: Chen Yi-An , Wang Yu-Ting , Moon Hyun Sik , Yong Kijung , Hsu Yung-Jung
Published: March 2021

This review gives a comprehensive retrospection on the preparation and photocatalytic applications of yolk–shell nanostructures with additional focus on the realization of interfacial charge dynamics.
Total and bioaccessible heavy metals in cabbage from major producing cities in Southwest China: health risk assessment and cytotoxicity
Authors: Li Mengying , Qin Yishu , Wang Chengchen , Wang Kun , Deng Zhihua , Xu Wumei , Xiang Ping , Ma Lena Q.
Published: March 2021

We analyzed the total and bioaccessible concentrations of heavy metals in a popular vegetable cabbage (Brassica oleracea) from producing cities in Yunnan, Southwest China and assessed their health risk based on both bioaccessibility and cytotoxicity.
Medicinal chemistry perspectives of 1,2,3,4-tetrahydroisoquinoline analogs – biological activities and SAR studies
Authors: Faheem  , Karan Kumar Banoth , Chandra Sekhar Kondapalli Venkata Gowri , Chander Subhash , Kunjiappan Selvaraj , Murugesan Sankaranarayanan
Published: March 2021

This review provides critical insights into the biological activities and Structure–Activity Relationship (SAR) studies of tetrahydroisoquinoline (THIQ) analogs.
Prominent roles of Ni(OH)2 deposited on ZnIn2S4 microspheres in efficient charge separation and photocatalytic H2 evolution
Authors: Guo Zhuang , Hou Huixia , Zhang Jingyi , Cai Pinglong , Lin Jun
Published: March 2021

The capture of the photogenerated holes by the deposited Ni(OH)2 contributes to the efficient charge separation, allowing more photogenerated electrons to be left on ZnIn2S4 to reduce H+ to H2.
High coercivity Pr2Fe14B magnetic nanoparticles by a mechanochemical method
Authors: Shang Xiaoyun , Tu Haoran , Zhang Jingjing , Ni Bingying , Wang Liying , Wang Minggang , Wu Chen , Zhao Zhankui
Published: March 2021

Nd2Fe14B nanoparticles are widely used because of their outstanding hard magnetic properties.
Rational design of iridium–porphyrin conjugates for novel synergistic photodynamic and photothermal therapy anticancer agents
Authors: Zhang Liping , Geng Yun , Li Lijuan , Tong Xiaofan , Liu Shi , Liu Xingman , Su Zhongmin , Xie Zhigang , Zhu Dongxia , Bryce Martin R.
Published: March 2021

Iridium–porphyrin conjugates assembled in nanoparticles are photosensitizers that exhibit excellent photothermal imaging and synergistic PDT and PTT in vivo.
Bimetallic cyclic redox couple in dimanganese copper oxide supported by nickel borate for boosted alkaline electrocatalytic oxygen evolution reaction
Authors: Bhowmick Sourav , Alam Suhaib , Shah Adit Kumar , Qureshi Mohammad
Published: March 2021

Self-redox mechanism in Mn2CuO4 is a crucial phenomenon for its high stability and activity towards oxygen evolution reaction.
Correction: Role of the spacer cation in the growth and crystal orientation of two-dimensional perovskites
Authors: Parikh Nishi , Tavakoli Mohammad Mahdi , Pandey Manoj , Kalam Abul , Prochowicz Daniel , Yadav Pankaj
Published: March 2021

Correction for ‘Role of the spacer cation in the growth and crystal orientation of two-dimensional perovskites’ by Nishi Parikh et al., Sustainable Energy Fuels, 2021, 5, 1255–1279, DOI: 10.1039/d0se01469a.
Dilatational rheology of water-in-diesel fuel interfaces: effect of surfactant concentration and bulk-to-interface exchange
Authors: Narayan Shweta , Barman Sourav , Moravec Davis B. , Hauser Brad G. , Dallas Andrew J. , Zasadzinski Joseph A. , Dutcher Cari S.
Published: March 2021

The dilatational modulus of water-in-diesel fuel interfaces stabilized by mono-olein and poly(isobutylene)succinimide (PIBSI) is measured using a capillary pressure microtensiometer.
Sunlight-activated phase change materials for controlled heat storage and triggered release
Authors: Shi Yuran , Gerkman Mihael A. , Qiu Qianfeng , Zhang Shuren , Han Grace G. D.
Published: March 2021

Photo-responsive organic phase change materials that can absorb filtered solar radiation in the visible range to store both latent heat and photon energy are demonstrated.
A photostable reaction-based A–A–A type two-photon fluorescent probe for rapid detection and imaging of sulfur dioxide
Authors: Zhang Qiang , Hu Xiaoxiao , Dai Xiaomei , Sun Junyong , Gao Feng
Published: March 2021

A novel BTD-based A–A–A type two-photon fluorescent probe with improved specificity, a fast response, and two-photon photostability has been successfully designed to detect exogenous and endogenous SO2 in HeLa cells and larval zebrafish.
A parallax view of type 1 diabetes
Authors: Weaver Staci A. , Felton Jamie L. , Evans-Molina Carmella
Published: March 2021

The year 2021 marks the 100th anniversary of the discovery of insulin, a therapy that transformed type 1 diabetes (T1D) from a once fatal diagnosis into a chronic condition that can be successfully managed with exogenous insulin administration. In this article, we celebrate the remarkable journey that led to the discovery of insulin and our subsequent understanding of T1D as a disease of immune-mediated β-cell destruction. Further, we discuss an alternative and parallax view of disease development, highlighting maladaptive β-cell responses that act to amplify immune responses and have been implicated in diabetes development.
Diagnostik und Therapie der aplastischen Anämie – Update 2021
Authors: Panse Jens
Published: March 2021

Was ist neu?

Diagnostik Telomeropathie-Erkrankungen und andere konstitutionelle Ursachen werden zunehmend auch im Erwachsenenalter als AA-Ursache erkannt. Screening-Untersuchungen, Erfassung der Familiengeschichte und körperliche Untersuchung auf mögliche Hinweise konstitutioneller Syndrome sind daher auch bei erwachsenen AA-Patienten durchzuführen.

Therapie Eine Stammzelltransplantation von unverwandten 10/10-Spendern ergibt fast ebenso gute Ergebnisse wie von Familienspendern bei Patienten unter 30. Eltrombopag ist zur Behandlung von refraktären Patienten mit schwerer aplastischer Anämie zugelassen. Patienten mit Chromosom-7-Anomalien sollen kein Eltrombopag erhalten; vor Eltrombopag-Therapie muss ein zytogenetisches Screening erfolgen. Patienten mit seltenen Erkrankungen wie der AA sollte die Anbindung an Patientenselbsthilfegruppen empfohlen werden und die Lebensqualität muss bei allen Therapieformen adäquat erfasst und gewürdigt werden.

Ausblick Eine immunsuppressive Therapie mit ATG und CSA wird zukünftig mit Eltrombopag kombiniert werden. Romiplostim, ein weiterer TRA, ist ebenfalls wirksam bei AA. Die differenzierte molekulare Diagnostik wird die Pathophysiologie klonaler Evolution weiter verstehbar machen.
Die asymptomatische Karotisstenose: Was ist neu?
Authors: Sander Dirk
Published: March 2021

Was ist neu?

Indikation zur Revaskularisation asymptomatischer Karotisstenosen Mit einer optimalen medikamentösen Therapie kann eine vergleichbare Risikoreduktion wie mit einer Revaskularisation erreicht werden. Daher empfiehlt die aktualisierte S3-Leitlinie, die Indikation zur Revaskularisation einer asymptomatischen hochgradigen Karotisstenose unter sorgfältiger Risiko-Nutzen-Abwägung individualisiert zu treffen. Voraussetzung ist, dass kein erhöhtes Operationsrisiko besteht und ein oder mehrere klinische oder bildgebende Befunde vorliegen, die mit einem erhöhten Schlaganfallrisiko assoziiert sind. Die periprozedurale Schlaganfallrate/Letalität soll maximal 2 % betragen.

Optimierte konservative Therapie (BMT) Die Einnahme von ASS (100 mg/Tag) führt bei Patienten mit asymptomatischer Karotisstenose zu einer signifikanten Reduktion der 5-Jahres-Mortalität auch nach Adjustierung für andere Risikofaktoren. Ein LDL-Zielwert < 70 mg/dl führt im Vergleich zu einem Zielwert von 90–110 mg/dl zu einer signifikant größeren Reduktion der Intima-Media-Dicke.
Aktueller Stellenwert der Kardio-MRT in Diagnostik und Therapie
Authors: Vietheer Julia M. , Hamm Christian W. , Rolf Andreas
Published: March 2021

Quantifizierung der links- und rechtsventrikulären Funktion Strain Imaging erweitert die klassische Volumetrie der MRT um einen sehr subtilen globalen und regionalen Funktionsparameter. Strain detektiert sehr frühe Funktionseinbußen beider Ventrikel, die visuell noch nicht erkennbar sind. Insbesondere der longitudinale Strain ist bei ischämischen und nichtischämischen Erkrankungen frühzeitig reduziert. Strain hat über die EF hinaus zusätzliche prognostische Bedeutung.

Gewebecharakterisierung T1- und T2-Mapping erweitern die klassische Gewebecharakterisierung mit Late Gadolinium Enhancement (LGE) um sehr subtile quantitative Parameter, die diffuse Fibrose (T1) und Ödem (T1 und T2) widerspiegeln.

Ischämiediagnostik Die Perfusions-MRT unter Vasodilatatorstress ist das genaueste Verfahren zur Ischämiediagnostik. Die MR-INFORM-Studie zeigt, dass mithilfe der Stress-MRT fast die Hälfte der Katheteruntersuchungen in einem Kollektiv mit hoher Prätestwahrscheinlichkeit vermieden werden kann. Dabei ist die Stress-MRT der FFR-basierten Strategie nicht unterlegen und genauso sicher.
Prärestaurative Aligner-Therapie eines Deckbisses mit
ausgeprägten Zahnhartsubstanzverlusten – ein
Fallbericht
Authors: Drechsler Thomas , Gernhardt Johannes
Published: March 2021

Ein interdisziplinäres Behandlungskonzept mittels Aligner-Therapie
bei einer adoleszenten Patientin mit Deckbisskonfiguration, asymmetrischer
Angle-Klasse-II-Verzahnung und ausgeprägten
Zahnhartsubstanzverlusten bei bestehender Bruxismus-Anamnese wird
vorgestellt.

Die geplanten kieferorthopädischen Maßnahmen sollten im Sinne
einer prärestaurativen Therapie neben funktionellen Verbesserungen
insbesondere eine orthoaxiale Frontzahninklination erreichen, um ausreichend
Platz zur morphologischen Rekonstruktion der abradierten Inzisiven zu
schaffen.

Die Aligner-Therapie bietet gerade bei erwachsenen Patienten mit
ausgeprägtem Bruxismusverhalten eine adäquate Alternative
zur herkömmlichen Multibracketapparatur, da sie neben
ästhetischen Aspekten gleichzeitig einen Schutz der Zahnhartsubstanz
gewährleistet.

Wichtig bei der initialen Behandlungsplanung, hier mittels
ClinCheck-Software/Align Technology, sind fundierte Kenntnisse des
Fachzahnarztes* zur Umsetzung des virtuellen, biomechanischen
Kraftmodells in das klinisch angestrebte Therapieziel.

Dabei spielen neben materialspezifischen Eigenschaften der Aligner
zusätzlich auch individuelle, körpereigene Reaktionen eine
Rolle, die das klinische Behandlungsergebnis beeinflussen können. So
konnte bei der hier therapierten Patientin neben der Korrektur der
Frontzahninklination auch die initial vorhandene Distalverzahnung ohne
Verwendung zusätzlicher Mechaniken allein durch
neuromuskuläre Adaptation infolge des vergrößerten
sagittalen Freiraums spontan verbessert werden.

Die Rekonstruktion der abradierten Inzisiven erfolgte im Anschluss an die
orthodontischen Maßnahmen zunächst provisorisch durch den
Behandler mittels Kompositaufbauten, welche durch Veneers oder (Teil-)Kronen
zur definitiven Langzeitrehabilitation ersetzt werden können.
Proctorship in Minimally Invasive Colorectal Surgery
Authors: Zahid Assad , Miskovic Danilo
Published: March 2021

Teaching an established surgeon in a novel technique by a colleague who has acquired a level of expertise is often referred to as “proctoring” or “precepting.” Surgical preceptorships can be defined as supervised teaching programs, whereby individual or groups of surgeons (proctors) experienced in a certain technique support a colleague who wants to adopt this technique (sometimes referred to as “delegates” or “preceptees”). Preceptorship programs really focus on a specific technique, technology, or skill which is required to broaden, complement, or transform an established surgeon's practice.

Within colorectal surgery, in the past 30 years, there is been an evolution of interventional options including open, laparoscopic, robotic, and endoscopic procedures. With each new emerging technology and technique, safe and effective uptake by established surgeons is best been attained by a period of proctorship by an experienced colleague. Formalizing this has been facilitated largely through industry support. There, however, remains a considerable chasm when it comes to standardization, quality control, and jurisprudence.

This article aims to describe the requirements for a contemporary proctorship program, to examine instruments of quality control, and how to improve effectiveness.
Development of a time of flight spectrometer based on position sensitive multi-wire proportional counters for fission fragment mass distribution studies
Authors: Jhingan Akhil , Saneesh N. , Kumar M. , Mahajan Ruchi , Thakur Meenu , Kaur Gurpreet , Kapoor K. , Kumar Neeraj , Shareef M. , Dubey R. , Appannababu S. , Prasad E. , Singh Hardev , Golda K. S. , Ahuja R. , Behera B. R. , Sugathan P.
Published: March 2021

Characteristics and performance of a time of flight (TOF) spectrometer developed for performing fission mass distribution studies are presented. The spectrometer contains two TOF arms based on multi-wire proportional counters (MWPCs). Each arm has two MWPCs to form a start–stop detection system for TOF measurements. The start detector has an active area of 4 × 4 cm2. The stop detector is a two-dimensional position sensitive MWPC with an active area of 16 × 11 cm2. Salient features of the MWPCs are the use of reduced sub-millimeter wire pitches of 0.635 and 0.317 mm in the electrodes along with the use of gold plated tungsten wires of diameters 10 and 20 µm. A delay line for position electrodes is prepared using chip inductors and capacitors. Ten different configurations of MWPC were investigated for the start detector, which involved the use of three and four electrode geometries, use of different wire pitches, and use of aluminized mylar for timing electrodes. Performance results close to micro-channel plate detectors have been observed with some designs of MWPC, displaying rise times better than 2 ns with an estimated inherent time resolution of ∼100 ps FWHM. A position resolution of ∼1 mm (FWHM) has been observed. Design features of the MWPCs and their test performance results are described in this article.
Estimation of Weibull parameters for wind energy analysis across the UK
Authors: Shu Z. R. , Jesson Mike
Published: March 2021

Harvesting wind energy resources is a major part of the UK strategy to diversify the power supply portfolio and mitigate environmental degradation. Based on wind speed data for the period 1981–2018, collected at 38 surface observation stations, this study presents a comprehensive assessment of wind speed characteristics by means of statistical analysis using the Weibull distribution function. The estimated Weibull parameters are used to evaluate wind power density at both station and regional levels and important, turbine-specific wind energy assessment parameters. It is shown that the Weibull distribution function provides satisfactory modeling of the probability distribution of daily mean wind speeds, with the correlation coefficient generally exceeding 0.9. Site-to-site variability in wind power density and other essential parameters is apparent. The Weibull scale parameter lies in the range between 4.96 m/s and 12.06 m/s, and the shape parameter ranges from 1.63 to 2.97. The estimated wind power density ranges from 125 W/m2 to 1407 W/m2. Statistically significant long-term trends in annual mean wind speed are identified for only 15 of the 38 stations and three of the 11 geographical regions. The seasonal variability of Weibull parameters and wind power density is confirmed and discussed.
Lessons from combined experimental and theoretical examination of the FTIR and 2D-IR spectroelectrochemistry of the amide I region of cytochrome c
Authors: El Khoury Youssef , Le Breton Guillaume , Cunha Ana. V. , Jansen Thomas L. C. , van Wilderen Luuk J. G. W. , Bredenbeck Jens
Published: March 2021

Amide I difference spectroscopy is widely used to investigate protein function and structure changes. In this article, we show that the common approach of assigning features in amide I difference signals to distinct secondary structure elements in many cases may not be justified. Evidence comes from Fourier transform infrared (FTIR) and 2D-IR spectroelectrochemistry of the protein cytochrome c in the amide I range, in combination with computational spectroscopy based on molecular dynamics (MD) simulations. This combination reveals that each secondary structure unit, such as an alpha-helix or a beta-sheet, exhibits broad overlapping contributions, usually spanning a large part of the amide I region, which in the case of difference absorption experiments (such as in FTIR spectroelectrochemistry) may lead to intensity-compensating and even sign-changing contributions. We use cytochrome c as the test case, as this small electron-transferring redox-active protein contains different kinds of secondary structure units. Upon switching its redox-state, the protein exhibits a different charge distribution while largely retaining its structural scaffold. Our theoretical analysis suggests that the change in charge distribution contributes to the spectral changes and that structural changes are small. However, in order to confidently interpret FTIR amide I difference signals in cytochrome c and proteins in general, MD simulations in combination with additional experimental approaches such as isotope labeling, the insertion of infrared labels to selectively probe local structural elements will be required. In case these data are not available, a critical assessment of previous interpretations of protein amide I 1D- and 2D-IR difference spectroscopy data is warranted.
Fabrication and characterization of an L3 nanocavity designed by an iterative machine-learning method
Authors: Shibata Takeshi , Asano Takashi , Noda Susumu
Published: March 2021

Optical nanocavities formed by defects in a two-dimensional photonic crystal (PC) slab can simultaneously realize a very small modal volume and an ultrahigh quality factor (Q). Therefore, such nanocavities are expected to be useful for the enhancement of light–matter interaction and slowdown of light in devices. In the past, it was difficult to design a PC hole pattern that makes sufficient use of the high degree of structural freedom of this type of optical nanocavity, but very recently, an iterative optimization method based on machine learning was proposed that efficiently explores a wide parameter space. Here, we fabricate and characterize an L3 nanocavity that was designed by using this method and has a theoretical Q value of 29 × 106 and a modal volume of 0.7 cubic wavelength in the material. The highest unloaded Q value of the fabricated cavities is 4.3 × 106; this value significantly exceeds those reported previously for an L3 cavity, i.e., ≈2.1 × 106. The experimental result shows that the iterative optimization method based on machine learning is effective in improving cavity Q values.
Generation of −10.7 dB unbiased entangled states of light
Authors: Wang Yajun , Zhang Wenhui , Li Ruixin , Tian Long , Zheng Yaohui
Published: March 2021

In a continuous variable quantum key distribution (CV-QKD) system, strong Einstein–Podolsky–Rosen entangled states can significantly boost the robustness and distance for secure communication. However, an inevitable bias of two entanglement quadratures may degrade the secret key rate and distance during random quadrature base switching. The bias originates from several interdependent factors in the generation, propagation, and detection of entangled states, which faces a challenge to be completely eliminated. Here, we analyze in detail the origin of the bias effect and report on a scheme of generating unbiased entangled states, whereby a −10.7 ± 0.1 dB quadrature noise unbiased entanglement is first generated experimentally with two single-mode squeezed states. The unbiased quadrature correlations within the measurement bandwidth are expected to immensely enhance the key rate and secure distance for CV-QKD.
Non-adiabatic Matsubara dynamics and non-adiabatic ring-polymer molecular dynamics
Authors: Chowdhury Sutirtha N. , Huo Pengfei
Published: March 2021

We present the non-adiabatic Matsubara dynamics, a general framework for computing the time-correlation function (TCF) of electronically non-adiabatic systems. This new formalism is derived based on the generalized Kubo-transformed TCF using the Wigner representation for both the nuclear degrees of freedom and the electronic mapping variables. By dropping the non-Matsubara nuclear normal modes in the quantum Liouvillian and explicitly integrating these modes out from the expression of the TCF, we derived the non-adiabatic Matsubara dynamics approach. Further making the approximation to drop the imaginary part of the Matsubara Liouvillian and enforce the nuclear momentum integral to be real, we arrived at the non-adiabatic ring-polymer molecular dynamics (NRPMD) approach. We have further justified the capability of NRPMD for simulating the non-equilibrium TCF. This work provides the rigorous theoretical foundation for several recently proposed state-dependent RPMD approaches and offers a general framework for developing new non-adiabatic quantum dynamics methods in the future.
Transistor-enabled reciprocity breaking in a mechanical lattice yielding giant isolation and unidirectional propagation
Authors: Kuchibhatla Sai Aditya Raman , Leamy Michael J.
Published: March 2021

This paper presents non-reciprocal information transfer between two mass-spring chains enabled using an electromechanical cell incorporating a metal–oxide–semiconductor field effect transistor (MOSFET). Mechanical information propagating through an input chain is converted into an electrical signal, and vice versa for an output chain, using a permanent magnet and a conducting coil in each chain. The conducting coils are coupled electrically via a MOSFET, leading to giant isolation and unidirectional signal transfer. We present theory, numerical simulations, and an experimental demonstration of the concept. The proposed system can be implemented as a “sonocoupler”, an acoustic analog of an optocoupler, which can isolate one mechanical system from another while transmitting information in a unidirectional manner.
A reconfigurable active acoustic metalens
Authors: Zhang Cheng , Cao Wen Kang , Wu Li Ting , Ke Jun Chen , Jing Yun , Cui Tie Jun , Cheng Qiang
Published: March 2021

Acoustic metasurfaces have enabled unprecedented control over acoustic waves, offering opportunities in areas such as holographic rendering, sound absorption, and acoustic communication. Despite the steady progress made in this field, most acoustic metasurface designs are passive in that they only provide static functionalities. Here, a reconfigurable active acoustic metalens is implemented to showcase scanning of the focus along arbitrary trajectories in free space with the help of a previously developed active acoustic metasurface platform. Each unit cell of the metasurface contains a cavity, whose size can be tuned continuously by a dynamic control system to adjust the phase of the reflected wave. While this work focuses on beam focusing, it could hold great promise for a wide range of applications including acoustic levitation and tweezers.
Density of states in locally ordered amorphous organic semiconductors: Emergence of the exponential tails
Authors: Novikov S. V.
Published: March 2021

We present a simple model of the local order in amorphous organic semiconductors, which naturally produces a spatially correlated exponential density of states (DOS). The dominant contribution to the random energy landscape is provided by electrostatic contributions from dipoles or quadrupoles. An assumption of the preferable parallel orientation of neighbor quadrupoles or antiparallel orientation of dipoles directly leads to the formation of the exponential tails of the DOS even for a moderate size of the ordered domains. The insensitivity of the exponential tail formation to the details of the microstructure of the material suggests that this mechanism is rather common in amorphous organic semiconductors.
Fast and robust exciton preparation in a coupled semiconductor quantum dot–metal nanoparticle system using shortcuts to adiabaticity
Authors: Smponias Athanasios , Stefanatos Dionisis , Paspalakis Emmanuel
Published: March 2021

We study the efficient preparation of the exciton state in a hybrid nanostructure composed by a semiconductor quantum dot and a metallic nanoparticle, when starting from the ground state, using pulses derived with the method of shortcuts to adiabaticity. We show with numerical simulations that high levels of exciton population can be obtained for a wide range of interparticle distances and for short pulse durations. This behavior appears also to be robust against small positioning errors of the system. The fidelity of the population inversion degrades for smaller distances and longer pulses, as the nonlinear terms in the equations, expressing the quantum dot–metal nanoparticle interaction, become stronger and affect the evolution for longer times. The present work is expected to help schemes toward the generation of single photons on demand or ultrafast nanoswitches, where the controlled population inversion in semiconductor quantum dots coupled to metal nanoparticles is an important task.
High-strain-rate mechanical response of HTPE propellant under SHPB impact loading
Authors: Zhang Heng-ning , Chang Hai , Li Jun-qiang , Li Xiao-jiang , Wang Han
Published: March 2021

The high-strain-rate dynamic response of a hydroxyl-terminated polyether (HTPE) propellant during impact loading is essential for assessing the structural reliability and impact safety of HTPE propellant. In this study, a modified split Hopkinson pressure bar (SHPB) apparatus has been developed to research the stress–strain behavior of the HTPE propellant over strain rates ranging from 470 to 5910 s−1 at room temperature, and the validity of the SHPB test is analyzed in detail. Meanwhile, the evolution of deformation to failure of the HTPE propellant was recorded by a high-speed digital camera synchronized with the SHPB test, which revealed the correlation between mechanical response and failure mode. Scanning electron microscopy was applied to investigate the microscopic failure mechanism of the post-test HTPE propellant, which indicated two characteristic failure modes: cracking propagates along the (1) debonding surface and (2) transgranular damage path. Finally, based on the stress–strain plots derived from the SHPB tests, the ultimate stress, strain energy density, and adiabatic temperature-rise effect of the HTPE propellant were seen to show strong strain rate dependence by following an empirical power law function.
Screening and discovery of phosphors by the single-particle-diagnosis approach
Authors: Wang Xiao-Jun , Xie Rong-Jun
Published: March 2021

Discovery of new phosphors becomes an endless topic with great advances in light sources and emissive displays. Traditional trial-and-error methods are time-consuming and inefficient, and innovative approaches are, therefore, required for speeding up the materials discovery. In this paper, the single-particle-diagnosis approach, a novel materials screening method based on single crystal x-ray diffractometry and single-particle luminescence, will be introduced. The concept of this approach is first interpreted, followed by presenting the crystal structure and photoluminescence of newly discovered nitride phosphors. Finally, future perspectives of the single-particle-diagnosis approach are demonstrated.
Optical refrigeration of the Yb3+-doped YAG crystal close to the thermoelectric cooling limit
Authors: Zhong Biao , Lei Yongqing , Duan Xuelu , Yang Tao , Yin Jianping
Published: March 2021

The Yb3+:YAG crystal has been one of the most widely used active media in the solid-state lasers of high power, mainly thanks to its excellent thermal, mechanical, and optical properties. Thermal effect due to heat deposition in the active medium, however, greatly deteriorates the beam quality of the laser output and sets a limit on its maximum power available. Although the cooling proposal of anti-Stokes fluorescence can help realize the heat-free high-power lasers with good beam quality, so-called radiation-balanced lasers, there is no substantial advancement in the optical cooling of Yb3+:YAG crystals since its latest experimental report with a temperature drop of about 9 K. Here we demonstrate experimentally a remarkable temperature drop of about 80 K in a 3% Yb3+-doped YAG single crystal pumped by a fiber laser at 1030 nm. Further analysis predicts that the cooling limit of the titled crystal can reach as low as 180 K from the room temperature. Our work therefore reveals a key pathway to facilitate the optical refrigeration of the Yb3+:YAG crystal down to the thermoelectric cooling limit, thus offering a unique entry point to practical radiation-balanced lasers.
Enhancement of the spin Seebeck effect owing to bismuth substitution in thermoelectric generators fabricated from LPE Bi-substituted YIG films
Authors: Imamura Masaaki , Asada Hironori , Nishimura Ryo , Yamaguchi Keita , Tashima Daisuke , Kitagawa Jiro
Published: March 2021

Raising the thermoelectric voltage in spin thermoelectric generators is an important subject. We investigated the substitution of bismuth for yttrium to increase spin pumping at the paramagnetic metal and ferrimagnetic insulator (PM/FMI) interface, and tested bismuth-substituted iron garnet films grown by liquid phase epitaxy. Epitaxial Bi-substituted iron garnet films exhibit large growth-induced magnetic anisotropy perpendicular to the film surface. This anisotropy increases the magnetic damping α in the FMI; α also increases with increasing Bi content. We report the rise in voltage observed in a spin thermoelectric generator incorporating Bi-substituted YIG films grown by liquid phase epitaxy, and explain the origin of the voltage rise based on the results of FMR measurements.
Flicker and random telegraph noise between gyrotropic and dynamic C-state of a vortex based spin torque nano oscillator
Authors: Wittrock Steffen , Talatchian Philippe , Romera Miguel , Garcia Mafalda Jotta , Cyrille Marie-Claire , Ferreira Ricardo , Lebrun Romain , Bortolotti Paolo , Ebels Ursula , Grollier Julie , Cros Vincent
Published: March 2021

Vortex based spin torque nano oscillators (STVOs) can present more complex dynamics than the spin torque induced gyrotropic (G) motion of the vortex core. The respective dynamic modes and the transition between them can be controlled by experimental parameters such as the applied dc current. An interesting behavior is the stochastic transition from the G-to a dynamic C-state occurring for large current densities. Moreover, the C-state oscillations exhibit a constant active magnetic volume. We present noise measurements in the different dynamic states that allow accessing specific properties of the stochastic transition, such as the characteristic state transition frequency. Furthermore, we confirm, as theoretically predicted, an increase of flicker noise with Idc2 when the oscillation volume remains constant with the current. These results bring insight into the potential optimization of noise properties sought for many potential rf applications with spin torque oscillators. Furthermore, the investigated stochastic characteristics open up new potentialities, for instance in the emerging field of neuromorphic computing schemes.
Acousto-optic modulation of light polarisation in monoclinic crystals
Authors: Chizhikov A.I. , Naumenko N.F. , Yushkov K.B. , Molchanov V.Ya. , Pavlyuk A.A.
Published: March 2021

A configuration of a laser polarisation modulator based on isotropic acousto-optic interaction is proposed. Polarisation control is performed by a 2D acousto-optic cell based on one monoclinic single crystal. A possibility of implementing this modulator on the basis of a KY(WO4)2 crystal is demonstrated.
Two-dimensional image edge enhancement using a spatial frequency filter of two-color radiation
Authors: Kotov V.M.
Published: March 2021

Two-dimensional optical image edge enhancement is investigated using a spatial acousto-optical (AO) filter operating at two wavelengths of optical radiation, which significantly increases the reliability of measurements and also reduces the effect of noise. The filter operates basing on diffraction of light in two diffraction orders. It is shown that, in the general case, it is impossible to obtain a two-dimensional image contour simultaneously at two wavelengths at the same energy and frequency-angular parameters of the AO filter. A regime has been found that makes it possible to switch from one wavelength to another while maintaining the operation of edge enhancement by changing the acoustic power. This regime has been experimentally confirmed by the example of the formation of a two-dimensional image contour using two-colour radiation of an Ar laser emitting at wavelengths of 0.488 × 10−4 and 0.514 × 10−4 cm, and an AO cell made of TeO2, operating at a sound frequency of 57 MHz.
Comparison of AlGaInAs/InP semiconductor lasers (λ = 1450 – 1500 nm) with ultra-narrow and strongly asymmetric waveguides
Authors: Volkov N.A. , Svetogorov V.N. , Ryaboshtan Yu.L. , Andreev A.Yu. , Yarotskaya I.V. , Ladugin M.A. , Padalitsa A.A. , Marmalyuk A.A. , Slipchenko S.O. , Lyutetskii A.V. , Veselov D.A. , Pikhtin N.A.
Published: March 2021

Semiconductor lasers based on AlGaInAs/InP heterostructures with ultra-narrow and asymmetric waveguides are comparatively studied. It is shown that the use of these waveguides with a simultaneous increase in the quantum well depth makes it possible to increase output powers. Such lasers based on both strongly asymmetric and ultra-narrow waveguides with a stripe contact width of 100 μm demonstrate an output power of 5 W (at pump currents of 11.5 and 14 A, respectively) in a continuous-wave regime at room temperature and a wavelength of 1450 – 1500 nm.
Associations between adolescent cannabis use and young-adult functioning in three longitudinal twin studies
Authors: Schaefer Jonathan D. , Hamdi Nayla R. , Malone Stephen M. , Vrieze Scott , Wilson Sylia , McGue Matt , Iacono William G.
Published: March 2021

Significance

A widely voiced concern regarding cannabis legalization in the United States is that cannabis is harmful to minors, affecting the developing brain to increase emotional and cognitive problems while impairing functioning. However, these associations may be due to confounding by common vulnerability factors that make some individuals more prone to both cannabis use and negative outcomes. We evaluate this possibility by conducting a series of cotwin control analyses in a sample that combines data from three longitudinal studies. Our findings provide little support for a strong, causal relationship between adolescent cannabis use and adult mental health or cognitive ability but do suggest that cannabis use may impair academic functioning during the secondary school years, with downstream effects on socioeconomic status.
Molecular mechanism of abnormally large nonsoftening deformation in a tough hydrogel
Authors: Ye Ya Nan , Cui Kunpeng , Hong Wei , Li Xueyu , Yu Chengtao , Hourdet Dominique , Nakajima Tasuku , Kurokawa Takayuki , Gong Jian Ping
Published: March 2021

Significance

Tough soft materials usually show strain softening. Avoiding strain softening, although important for practical application, had not been a focus of research. Recently, a series of tough hydrogels made from hyperconnective physical networks and linear polymers as molecular glue show extraordinarily large nonsoftening, quasi-linear but inelastic deformation. Here, we studied the molecular mechanism of this behavior and clarified that it is a direct consequence of the interplay between hyperconnectivity of the skeleton network and the stress transfer through molecular glues. We believe that this work gives important insight on the design and development of tough soft materials without strain softening.
An ancient, conserved gene regulatory network led to the rise of oral venom systems
Authors: Barua Agneesh , Mikheyev Alexander S.
Published: March 2021

Oral venom systems evolved multiple times in numerous vertebrates, enabling the exploitation of unique predatory niches. Yet how and when they evolved remains poorly understood. Up to now, most research on venom evolution has focused strictly on toxins. However, using toxins present in modern-day animals to trace the origin of the venom system is difficult, since they tend to evolve rapidly, show complex patterns of expression, and were incorporated into the venom arsenal relatively recently. Here we focus on gene regulatory networks associated with the production of toxins in snakes, rather than the toxins themselves. We found that overall venom gland gene expression was surprisingly well conserved when compared to salivary glands of other amniotes. We characterized the “metavenom network,” a network of ∼3,000 nonsecreted housekeeping genes that are strongly coexpressed with toxins and are primarily involved in protein folding and modification. Conserved across amniotes, this network was coopted for venom evolution by exaptation of existing members and the recruitment of new toxin genes. For instance, starting from this common molecular foundation,
Heloderma
lizards, shrews, and solenodon evolved venoms in parallel by overexpression of kallikreins, which were common in ancestral saliva and induce vasodilation when injected, causing circulatory shock. Derived venoms, such as those of snakes, incorporated novel toxins, though they still rely on hypotension for prey immobilization. These similarities suggest repeated cooption of shared molecular machinery for the evolution of oral venom in mammals and reptiles, blurring the line between truly venomous animals and their ancestors.
Potent neutralization of Rift Valley fever virus by human monoclonal antibodies through fusion inhibition
Authors: Chapman Nathaniel S. , Zhao Haiyan , Kose Nurgun , Westover Jonna B. , Kalveram Birte , Bombardi Robin , Rodriguez Jessica , Sutton Rachel , Genualdi Joseph , LaBeaud A. Desiree , Mutuku Francis M. , Pittman Phillip R. , Freiberg Alexander N. , Gowen Brian B. , Fremont Daved H. , Crowe James E.
Published: March 2021

Significance

Rift Valley fever virus (RVFV)–specific monoclonal antibodies from survivors of natural infection and vaccination were isolated to understand how RVFV is targeted for neutralization by the human immune system. These antibodies bind to specific regions of the viral surface, some of which are complex quaternary epitopes, and they block RVFV infection at extremely low concentrations. A new mechanism by which these mAbs can neutralize RVFV is described whereby the antibody may prevent necessary structural rearrangements in the viral proteins for infection. The antibodies isolated here have potential use in pre-exposure prophylaxis or post-exposure therapy against RVFV infection and should be studied further in that context.
Gymnandrosoma aurantianum (citrus fruit borer).
Authors: Brown John W.
Published: March 2021

Gymnandrosoma aurantianum is a small blackish brown to black tortricid moth with a whitish or pale pinkish, grub-like larva that feeds on the buds and fruit of several plant families, primarily Rutaceae and Sapindaceae. In 2000, economic loss caused by the damage of G. aurantianum to citrus fruit in the state of São Paulo, Brazil was estimated at 50 million USD. The species is native to much of South America, but may be introduced in Central America and the Caribbean, where it feeds on hosts other than citrus. It is encountered in native forests, orchards and urban landscapes, usually below 500 m elevation. In Costa Rica it has been found at higher elevations, such as Tilarán (564 m elevation), Turrialba (646 m elevation) and Juan Viñas (1165 m elevation). Although there is no evidence that it has successfully invaded any region outside of the New World tropics, the species has been intercepted at ports-of-entry on several occasions in shipments of citrus from Brazil, and the NPPO of Spain has suggested that G. aurantianum should be added to the EPPO Alert List.
Calacarus carinatus (purple tea mite).
Authors: Beverley Claire
Published: March 2021

C. carinatus is a mite native to Asia. It is now also present in Africa, Europe, the USA and Australia. It usually attacks camellias and can reduce tea leaf production. In Kenya, C. carinatus has resulted in loss of capital due to the reduction in tea leaf production.
Ferrisia virgata (striped mealybug).
Authors: Watson Gillian
Published: March 2021

Ferrisia virgata is a highly polyphagous mealybug. It reproduces quite rapidly in tropical conditions, but it tolerates subtropical and to some extent temperate conditions too. It has been reported on host-plants belonging to over 203 genera in 77 families, and can damage many crops, particularly tropical fruit, nut and spice crops and field crops like soybean and tomato. It is known to transmit plant badnavirus diseases of cocoa and black pepper. It is of Neotropical origin and spread around the world in only about 10 years after being first described from Jamaica. Its polyphagy has facilitated its spread by human transport of infested plants, and it is now established in all the subtropical and tropical zoogeographic regions. Its small size and cryptic habits make it difficult to detect and identify at plant quarantine inspection. The increase in international trade in fresh plant material in recent years is likely to facilitate its continued spread.
Impatiens glandulifera (Himalayan balsam).
Authors: Pollard Kate , Tanner Rob
Published: March 2021

I. glandulifera is a highly invasive annual species which has spread rapidly in many parts of Europe and North America after its introduction as an ornamental. The spread is likely to continue to more northerly or high montane areas as a result of global climatic change. Due to its ability to form dense stands and its conspicuous appearance it has been blamed for negative biodiversity effects. Even though these effects are less severe than often thought, further spread is undesirable and should not be facilitated by further use, in particular in natural areas. Control is advisable in certain situations, e.g. nature reserves and conservation sensitive areas, but eradication from larger parts of its invasive range is not feasible due to the need to control the plant on a catchment scale, which is often impossible due to the sheer scale of occurrence and division of land ownership.
Pennisetum clandestinum (Kikuyu grass).
Authors: Parker Chris
Published: March 2021

P. clandestinum is an aggressive perennial plant, spreading by rhizomes below ground, especially by long runners above ground, and it also sets seed. It is native to the highlands of eastern Africa but has been widely introduced elsewhere for forage and for soil conservation. In well managed situations it does not generally spread very far but it is highly tolerant of grazing and mowing and can steadily invade poorly managed plantations. It also readily invades natural vegetation with resultant loss of biodiversity. This has occurred in Australia, New Zealand, South Africa, Hawaii and the Galapagos. It is listed as a Federal Noxious Weed in the USA.
Sclerophthora rayssiae var. zeae (brown stripe downy mildew of maize).
Authors: Magill Clint
Published: March 2021

The first record of brown stripe downy mildew of maize occurred in India in the early 1960s. In 1967, the pathogen was defined as Sclerophthora rayssiae var. zeae by Payak and Renfro. It spread rapidly across India, especially in regions with over 100 cm of annual rainfall and into neighbouring countries, probably via seed transfer. It has been effectively controlled by the use of resistant hybrids and seed treatment. It is not reported to be an invasive species.
Xylosandrus mutilatus (camphor shoot beetle).
Authors: Mattson William
Published: March 2021

X. mutilatus is a polyphagous ambrosia beetle, of possible relevance as a pest, that is indigenous to at least 10 countries in eastern and southern Asia (Japan to India). It has been recently discovered (1999) in the warm temperate, southeastern United States (Alabama, Georgia, Florida, Mississippi, Tennessee, and Texas), the only region occupied outside of its native Asian range. In northern Mississippi, it has multiplied prolifically and appears therefore highly capable of surviving and spreading in its newly adopted territory.
Aphis glycines (soyabean aphid).
Authors: Hodgson Erin
Published: March 2021

A. glycines is distributed throughout eastern Asia, principally in China, Japan, Indonesia, Thailand, Korea, far eastern Russia, North Borneo, peninsular Malaysia and the Philippines (Blackman and Easop, 2000). It is a major pest of soyabean in China, causing particularly severe economic losses in the regions of Jilin, Liaoning, Heilongjiang and Neimenggu (Wang et al., 1962). It attacks soyabeans and is also a minor pest on other leguminous crops. It has recently been introduced into Australia, Canada and the USA (Fletcher and Desborough, 2000; Edwards et al., 2001; Michelutti et al., 2002). It has quickly become a soyabean pest in North America, where aphids had previously not attacked soyabeans (Ragsdale et al., 2011). A. glycines causes economic injury due to direct feeding, and indirect injury due to the spread of viruses, in particular Soybean mosaic virus (SMV).
An intubation catheter integrated with flow sensors and smart actuators for characterizing airflow patterns in stenosed trachea: an objective guide for CAO management
Authors: Alekya B , Sitaramgupta V V S N , Arjun B S , Bhushan V , Abishek Kevin , Rao Sanjay , Kim Yeongjin , Pandya Hardik J
Published: March 2021

Stenosis reduces the effective lumen area in the tracheal and bronchial segments of the airway anatomy. Loss in patency due to obstruction increases resistance to airflow; thus, severe narrowing is often associated with morbidity and mortality. Etiologies such as congenital tracheal stenosis, tracheomalacia, laryngeal and subglottic stenosis, atresia are few among the many pathologies causing major airway obstruction and respiratory distress. Diagnosis of such anomalies is usually based on clinical suspicion due to the non-specificity of the associated clinical symptoms. Visual assessment using conventional bronchoscopy or radiography images from CT scan for precisely locating obstruction site is highly subject to clinician’s expertise. Characterizing airflow patterns in stenosed airway calls for newer diagnostic tools that can effectively quantify changes in airflow due to construction sites. Our work presents a steerable intubation catheter that can quantitatively measure air velocity across various segments of the tracheobronchial tree. The catheter consists of a three-layer flexible printed circuit board integrated with micro-electro-mechanical system-based thermal flow sensors and a pair of sub-millimeter helical shape memory actuators. Flow distribution is measured in excised sheep tracheal tissues at 15, 30, 50, 65, and 80 l min−1 for normal and stenosed conditions. Even a 10% reduction in lumen area generated unique peaks corresponding to the obstruction site; thus, the catheter can locate stenosis at the precritical stage. For 50% tracheal obliteration, the sensor closest to stenosis showed a 2.4-fold increase in velocity when tested for reciprocating flows. Thus, flow rate scales quadratically with reducing cross-section area, contributing to increased airflow resistance.