bluuebunny/crossref_metadata_2025 huggingface dataset:
Transition metal- and light-free radical borylation of alkyl bromides and iodides using silane
Authors: Sun Beiqi , Zheng Sihan , Mo Fanyang
Published: April 2021

We report operationally simple and neutral conditions for borylation of alkyl bromides and iodides to alkyl boronic esters under transition metal- and light-free conditions.
The Sc2WxMo3−xO12 series as electrodes in alkali-ion batteries
Authors: Liu Junnan , Johannessen Bernt , Brand Helen E. A. , Andersen Henrik L. , Sharma Neeraj
Published: April 2021

Herein, the series Sc2WxMo3−xO12 (0 ≤ x ≤ 3) is synthesised and the structure and electrochemical performance in alkali-ion batteries is characterised.
Two-dimensional Weyl semi-half-metallic NiCS3 with a band structure controllable by the direction of magnetization
Authors: Li Gui-Gui , Xie Rong-Rong , Ding Li-Juan , Ji Wei-Xiao , Li Sheng-Shi , Zhang Chang-Wen , Li Ping , Wang Pei-Ji
Published: April 2021

A NiCS3 monolayer has 12 fully spin-polarized Weyl nodal points in one spin channel. It is possible to control the opening and closing of Weyl points by applying and rotating external magnetic fields.
A kinetic model of thin-film fluorescent sensors for strategies to enhance chemical selectivity
Authors: Campbell Iain A. , Turnbull Graham A.
Published: April 2021

An analytical model was developed for thin film chemical sensors which provides insight into the sensor dynamics and potential strategies to develop chemical recognition.
Study of colored lacquerwares from Zenghou Yi Tomb in Early Warring States
Authors: Wu Meng , Zhang Yunfan , Zhang Bingjian , Li Lan
Published: April 2021

Yellow pigment on the lacquerware from Zenghou Yi Tomb was glued by gelatin instead of lacquer.
Sakrale Wurzeltaschenzysten - Epidemiologie, Diagnostik und Therapie
Authors: Neulen Axel , Jägersberg Max , Brockmann Carolin , Ringel Florian
Published: April 2021

Sakrale Wurzeltaschenzysten (Tarlov Zysten) sind Zysten, die von den sakralen Nervenwurzeln ausgehen. Sie stellen in der wirbelsäulenchirurgischen Sprechstunde ein eher seltenes Krankheitsbild dar. Allerdings berichten radiologische Studien von einer relativ hohen Prävalenz von bis zu 8,9%, wobei nur ein sehr kleiner Teil der Zysten symptomatisch wird. Die Symptome können sich einerseits in mono- oder polyradikulären Beschwerden wie Ischialgien, sensiblen Defiziten, Paresen oder Blasen-/Mastdarmstörungen äußern, andererseits in Schmerzen wie tief sitzenden Lumbalgien, sakralen Schmerzen, einer Coccygodynie oder auch abdominellen Schmerzen. Die Diagnose einer Wurzeltaschenzyste wird in der Schnittbildgebung gestellt, meist in der Magnetresonanztomographie. Eine Myelographie erlaubt die Differenzierung zwischen Zysten mit und ohne freier Kommunikation mit dem Liquorraum. Bei persistierenden der Zyste zuzuordnenden Beschwerden stehen operative wie auch interventionelle Verfahren zur Verfügung.
Immuntherapie mit vielversprechenden Studienergebnissen
Authors: Schmale Ine
Published: April 2021

Die Therapielandschaft für Patientinnen mit tripel-negativem Mammakarzinom kann mit neuen Wirkstrategien erweitert werden. Ein wirksamer Mechanismus ist die Checkpoint-Blockade mit PD-(L)1-Antikörpern, die schon bei anderen onkologischen Entitäten zu teils drastischen Änderungen im Therapiealgorithmus geführt hat. Beim SABCS wurden Analysen der Studien KEYNOTE-355 und IMpassion-031 präsentiert.
Nebenwirkungsmanagement unter Checkpoint-Inhibitor-Therapie
Authors: Schmale Ine
Published: April 2021

Mit der Zulassung der Checkpoint-Inhibitoren zur Behandlung des metastasierten Melanoms begann 2016 die Erfolgsgeschichte der Immuntherapie. Neben einer langanhaltenden Wirksamkeit wurde auch die Erhaltung einer guten Lebensqualität beobachtet. Durch die wachsende Erfahrung in der Anwendung dieser Wirkstoffklasse wird das Management mit immunvermittelten Nebenwirkungen effizienter. Da Immuntherapien in immer früheren Therapielinien eingesetzt werden und die Patienten langfristig überleben, nimmt die Forschung zu den Nebenwirkungen einen wachsenden Stellenwert ein. Beim Deutschen Hautkrebskongress 2020 waren 2 große Symposien den unerwünschten Ereignissen unter Checkpoint-Inhibitor-Therapie gewidmet.
Besserer Outcome unter Radium-223 plus Enzalutamid versus Enzalutamid allein
Authors: Kretzschmar Alexander
Published: April 2021

Bei Patienten mit metastasiertem kastrationsresistentem Prostatakarzinom führt die zusätzliche Therapie mit Radium-223 zusammen mit Enzalutamid zu einer signifikanten Verlängerung des progressionsfreien Überlebens (PFS) und der Verbesserung anderer Therapiemarker. Das ergab eine neue Auswertung einer Phase-II-Studie (NCT02199197), die auf dem ASCO-GU vorgestellt wurde.
Evidenz beim neu diagnostizierten und rezidivierten Glioblastom
Authors: Kretzschmar Alexander
Published: April 2021

Die Laser-induzierte Thermotherapie (Laser Interstitial Thermal Therapy, LITT) wird bereits erfolgreich als minimal invasives Verfahren zur lokalen Behandlung maligner hepatozellulärer Karzinome eingesetzt. Zwei systematische Reviews haben sich jetzt mit der vorliegenden Evidenz zum Einsatz bei Patienten mit neu diagnostiziertem bzw. rezidiviertem Glioblastom beschäftigt.
ESMO-EANO-Guidelines definieren erstmals Behandlungsstandards
Authors: Kretzschmar Alexander
Published: April 2021

Patienten mit Gehirntumoren benötigen ein engmaschiges Monitoring aufgrund der zahlreichen möglichen Komplikationen. Dazu gehören insbesondere epileptische Anfälle, Hirnödeme sowie Blutungen und Thrombosen. Bisher fehlten allerdings einheitliche Standards zur Diagnostik und Therapie dieser Beschwerdebilder bei dieser Patientenpopulation. Mit den neuen Guidelines haben die beiden onkologischen Gesellschaften ESMO (European Society for Medical Oncology) und EANO (European Association of Neuro-Oncology) jetzt erstmals Standards für das praktische Management dieser Komplikationen vorgelegt.
Stellenwert der operativen multimodalen venösen Thrombektomie bei der Behandlung der akuten iliofemoralen Thrombose
Authors: Mühlberger Dominic , Falkenstein Thomas , Mumme Achim , Stücker Markus , Reich-Schupke Stefanie , Hummel Thomas
Published: April 2021

Für das Gros aller Patienten mit tiefer Beinvenenthrombose ist ein konservatives Vorgehen mit Antikoagulation und Kompression die Therapie der Wahl. In ausgewählten Fällen kann jedoch auch ein rekanalisierendes Therapieverfahren zum Einsatz kommen. Dies gilt speziell für besonders ausgedehnte Thrombosen mit Beteiligung der Vena cava oder der Beckenetage. Die multimodale operative Thrombektomie kann ein drohendes postthrombotisches Syndrom abwenden. Die Vorteile der operativen Therapie liegen vor allem in der hohen Effektivität und einer breiten Anwendbarkeit, auch bei Kontraindikation zur Fibrinolysetherapie.
Autoimmunerkrankung Typ-1-Diabetes
Authors: Scherm Martin G. , Daniel Carolin
Published: April 2021

Die umfassende Erforschung der Immunologie des Typ-1-Diabetes kann entscheidend zu unserem Verständnis der Krankheit beitragen. Hierbei ist insbesondere auch die Identifizierung der zugrundeliegenden Signalwege, die zur fehlerhaften Immuntoleranz sowie der Aktivierung und dem Fortschreiten der Inselautoimmunität beitragen, von entscheidender Bedeutung für die Entwicklung zukünftiger Interventionsstrategien, um die Entstehung von Typ-1-Diabetes zu verlangsamen oder sogar ganz zu verhindern 1. So bieten kürzlich identifizierte miRNAs, die zur Entstehung von Inselautoimmunität beitragen, einen vielversprechenden Ansatz, um Treg-vermittelte Toleranzdefekte mittels gezielter miRNA-Modulation zu reduzieren.
Risk evaluation of duodenoscope-associated infections in the Netherlands calls for a heightened awareness of device-related infections: a systematic review
Authors: Kwakman Judith A. , Erler Nicole S. , Vos Margreet C. , Bruno Marco J.
Published: April 2021

Background The risk of exogenous infections from endoscopic procedures is often cited as almost negligible (1 infection in 1.8 million procedures); however, this risk is based on older literature and does not seem to match the number of infectious outbreaks due to contaminated duodenoscopes reported after endoscopic retrograde cholangiopancreatography (ERCP). Using Dutch data, we aimed to estimate the minimum risk of duodenoscope-associated infection (DAI) and colonization (DAC) in patients undergoing ERCP.

Methods A systematic literature search identified all DAI outbreaks in the Netherlands reported between 2008 and 2019. Included cases were confirmed by molecular matching of patient and duodenoscope cultures. Risk ratios were calculated based on the total number of ERCPs performed during the study period.

Results Three outbreaks were reported and published between 2008 and 2018, including 21 confirmed DAI cases and 52 confirmed DAC cases. The estimated number of ERCPs performed during the same period was 181 209–227 006. The calculated minimum estimated DAI risk was approximately 0.01 % and the minimum estimated DAC risk was 0.023 %–0.029 %.

Conclusions The estimated risk of DAI in Dutch ERCP practice was at least 180 times higher than previously published risk estimates. The actual risk is likely to be (much) higher due to underreporting of infections caused by multidrug-resistant organisms and sensitive bacteria. Greater awareness by healthcare personnel involved in endoscopy and endoscope cleaning is required, as well as innovative technical solutions to contain and ultimately eliminate DAIs.
Illuminating a Path4914. Copyright 2016 Wiley for Organic Synthesis Towards Sustainability. No One Said It Would Be Easy…
Authors: Lipshutz Bruce H.
Published: April 2021

A personalized account is presented describing some of the stories behind the scenes in efforts to convert organic chemistry into a more sustainable discipline. These are part of a group ‘crusade’ started almost 15 years ago aimed at providing technologies illustrative of how key reactions used today can be ‘faster, better, cheaper’ when run in recyclable water. Hence, the option now exists to do organic synthesis in a far more environmentally responsible fashion. By contrast, most of organic chemistry developed over the past 200 years that relies on organic solvents continues to generate enormous amounts of pollution, while depleting finite petroleum reserves and our supplies of many precious and base metals. Making the switch to water, Nature’s chosen reaction medium, akin to that in which bio-catalysis is typically performed, is inevitable.

1 The Story Begins: A Different Type of Prejudice

2 Are We up to the Challenge? Too Late Now…

3 ‘Impossible’ Reactive Metal Chemistry in Water

4 Didn’t I Once Say: ‘It’s All about the Ligand’?

5 What Happens When Our Supply of Palladium Runs Out?

6 What Are the Implications from These Tales for Today and Tomorrow?

7 What Is the ‘Broader Impact’ of This Work?

8 The Bottom Line…
Primary Systemic Therapy for HER2/Neu-Positive Operable Breast Cancer Increases the Number of Breast-Conserving Surgery and Disease-Free Survival: Retrospective Cohort Analysis at Single Institution
Authors: Azhar Yohana , Agustina Hasrayat , Hernowo Bethy S
Published: April 2021

Objective The aim of this study was to evaluate the efficacy and cardiotoxicity profile, and to reduce the extend of breast cancer surgery in primary systemic therapy (PST) HER2/neu–positive operable breast cancer patients.

Materials and Methods A total of 152 patients diagnosed from 2010 to 2015 were included in the study. The PST consisted of a sequential regimen of taxanes and anthracyclines plus trastuzumab. The clinical and pathological responses and the type of breast cancer surgery were evaluated and correlated with clinical and biological factors. The cardiotoxicity profile and long-term benefits were analyzed.

Results The median patient age was 47 (37–67) years, with T2 and T3 67 (44.1%) and 85 (55.9%), respectively. Axillary lymph node breast cancer at diagnosis N0 was 104 (68.4%) and N1 and N2 were 28.9% and 2.6%, respectively. A total of 95.7% of patients had nonspecific type of breast cancer, 67% of tumors were hormonal receptor–negative, 75.5% were grade III, 100% Ki67 > 20%, and 90% of tumors were confirmed to be HER2/neu–positive through immunohistochemistry. Following PST, pathological complete response (pCR) rate was achieved in 44.7% evaluable patients. The pCR rate was higher in HR-negative (93.1% vs. 6.9%) cancer and in grade III (86.2%) than in grade I and II (13.8%) cancer; only 75.5% of complete response (CR) on ultrasound and magnetic resonance imaging were also CR on pathology results. Breast conserving surgery was performed in 41.4%. Regarding type of chemotherapy, there were no significant differences between chemotherapy with anthracycline backbone or taxanes to achieved pathological complete response. Despite that, we were unable to demonstrate an association between pCR and better DFS with p = 0.096; HR 5.7 95.0% CI (0.73–45.52). Patients who are hormonal receptor positive tend to have lower disease-free survival (DFS) than those who are hormonal receptor negative; HR = 6.34, 95.0% CI (1.54–26.00) and p = 0.010. Five years DFS was higher for those who achieved pCR compare with those who did not. Even in this research we failed to show it is statistically significant.

Conclusion A sequential regimen of taxanes and anthracyclines plus trastuzumab was effective with high pCR rates and increases the possibility to do breast conservation surgery and had tolerable cardiotoxicity profile.
Thermal management of a 3D packaging structure for superconducting quantum annealing machines
Authors: Feng Wei , Kikuchi Katsuya , Hidaka Mutsuo , Yamamori Hirotake , Araga Yuuki , Makise Kazumasa , Kawabata Shiro
Published: April 2021

Quantum annealing (QA) is a computing paradigm for solving combinatorial optimization problems by finding the low-energy configurations of complicated Ising models through quantum fluctuation. Recently, because of the strictly limited number of superconducting qubits per chip, three-dimensional (3D) integrated technologies have attracted great attention for realizing a practical large-scale QA machine. Because a cryogenic environment is required for qubit chip operation, the less-effective heat transfer in the stacked structure has become a major concern. In the present paper, a method to realize a sufficiently low temperature for quantum operation in large-scale superconducting QA machines based on 3D packaging technology is proposed and demonstrated numerically. We reveal that the heating in such a 3D structure, which seriously reduces the quantum coherence of qubit chips, is effectively prevented by adding through-silicon vias (TSVs). Accordingly, the temperature of the qubit chip is drastically reduced from 57.8 mK to 16.4 mK. Our results indicate that using TSVs are a powerful and simple approach to realizing practical large-scale superconducting QA machines.
Measurements of neutron fluxes from tokamak plasmas using a compact neutron spectrometer
Authors: Iliasova M. V. , Shevelev A. E. , Khilkevitch E. M. , Lebedev S. V. , Askinazi L. G. , Kornev V. A. , Minaev V. B. , Tukachinsky A. S. , Doinikov D. N. , Polunovsky I. A. , Naidenov V. O. , Gin D. B.
Published: April 2021

A compact neutron spectrometer based on the BC-501A liquid organic scintillator was applied to neutron measurements at the TUMAN-3M tokamak. The spectrometer was calibrated using measurements from the ion beam of the cyclotron accelerator. Neutron spectra were measured during discharges using a neutral deuterium beam injection into the TUMAN-3M D-plasma. An energy distribution of the neutrons from the plasma that hit the spectrometer was obtained from the measured BC-501A instrumental spectra by the DeGaSum code using detector response functions obtained in the course of the calibration. This allowed for the estimation of the 2.45 MeV neutron yield and the evaluation of both the time evolution of the DD fusion rate and the characteristic time of the injected deuterium slowing down in discharges with neutral beam injection heating.
Macroscopic and microscopic stabilization mechanisms of unstable interface with interfacial mass flux
Authors: Ilyin D. V. , Abarzhi S. I.
Published: April 2021

Unstable interfaces are omnipresent in plasma processes in nature and technology at astrophysical and at molecular scales. This work investigates the interface dynamics with interfacial mass flux and focuses on the interplay of macroscopic and microscopic stabilization mechanisms, due to the inertial effect and the surface tension, respectively, with the destabilizing acceleration. We derive solutions for the interfacial dynamics conserving mass, momentum, and energy and find the critical values of the acceleration, density ratio, and surface tension separating the stable and unstable regimes. While the surface tension influences only the interface, its presence leads to the formation of vortical structures in the bulk. The vortical structures are energetic in nature, and the velocity field is shear free at the interface. We find that the conservative dynamics is unstable only when it is accelerated and when the acceleration value exceeds a threshold combining the contributions of macroscopic and microscopic mechanisms. In the unstable regime, the interface dynamics corresponds to the standing wave with the growing amplitude and has the growing interface velocity. For strong accelerations and weak surface tensions typical for high energy density plasmas, the unstable conservative dynamics is the fastest when compared to other instabilities; it has finite values of the initial perturbation wavelength at which the interface is stabilized and at which its growth is the fastest. We elaborate extensive theory benchmarks for experiments and simulations and outline its outcomes for application problems in nature and technology.
DLPNO-MP2 second derivatives for the computation of polarizabilities and NMR shieldings
Authors: Stoychev Georgi L. , Auer Alexander A. , Gauss Jürgen , Neese Frank
Published: April 2021

We present a derivation and efficient implementation of the formally complete analytic second derivatives for the domain-based local pair natural orbital second order Møller–Plesset perturbation theory (MP2) method, applicable to electric or magnetic field-response properties but not yet to harmonic frequencies. We also discuss the occurrence and avoidance of numerical instability issues related to singular linear equation systems and near linear dependences in the projected atomic orbital domains. A series of benchmark calculations on medium-sized systems is performed to assess the effect of the local approximation on calculated nuclear magnetic resonance shieldings and the static dipole polarizabilities. Relative deviations from the resolution of the identity-based MP2 (RI-MP2) reference for both properties are below 0.5% with the default truncation thresholds. For large systems, our implementation achieves quadratic effective scaling, is more efficient than RI-MP2 starting at 280 correlated electrons, and is never more than 5–20 times slower than the equivalent Hartree–Fock property calculation. The largest calculation performed here was on the vancomycin molecule with 176 atoms, 542 correlated electrons, and 4700 basis functions and took 3.3 days on 12 central processing unit cores.
Atom interferometry with quantized light pulses
Authors: Soukup Katharina , Di Pumpo Fabio , Asano Tobias , Schleich Wolfgang P. , Giese Enno
Published: April 2021

The far-field patterns of atoms diffracted from a classical light field or from a quantum one in a photon-number state are identical. On the other hand, diffraction from a field in a coherent state, which shares many properties with classical light, displays a completely different behavior. We show that in contrast to the diffraction patterns, the interference signal of an atom interferometer with light-pulse beam splitters and mirrors in intense coherent states does approach the limit of classical fields. However, low photon numbers reveal the granular structure of light, leading to a reduced visibility since welcher-Weg (which-way) information is encoded into the field. We discuss this effect for a single photon-number state as well as a superposition of two such states.
Stacking faults: Origin of leakage current in halide vapor phase epitaxial (001)
β
-Ga2O3 Schottky barrier diodes
Authors: Sdoeung Sayleap , Sasaki Kohei , Masuya Satoshi , Kawasaki Katsumi , Hirabayashi Jun , Kuramata Akito , Kasu Makoto
Published: April 2021

Killer defects are responsible for leakage current and breakdown in β-gallium oxide (β-Ga2O3) Schottky barrier diodes, which are crucial for power device applications. We have found that stacking faults in the halide vapor phase epitaxial (HVPE) (001) layer are killer defects. One type of defect is found to consist of (111) and (11¯1) stacking faults. The leakage current is 50 nA/defect at −200 V. This defect appears as a heart-shaped etch pit. Another type of defect is found to be a sequence of stacking faults from microparticles, which are formed at low gas flow rate during HVPE growth. The leakage current is 0.11–0.49 μA/defect at −200 V. This defect appears as a group of bullet-shaped etch pits.
On the molecular electronic flux: Role of nonadiabaticity and violation of conservation
Authors: Hanasaki Kota , Takatsuka Kazuo
Published: April 2021

Analysis of electron flux within and in between molecules is crucial in the study of real-time dynamics of molecular electron wavepacket evolution such as those in attosecond laser chemistry and ultrafast chemical reaction dynamics. We here address two mutually correlated issues on the conservation law of molecular electronic flux, which serves as a key consistency condition for electron dynamics. The first one is about a close relation between “weak” nonadiabaticity and the electron dynamics in low-energy chemical reactions. We show that the electronic flux in adiabatic reactions can be consistently reproduced by taking account of nonadiabaticity. Such nonadiabaticity is usually weak in the sense that it does not have a major effect on nuclear dynamics, whereas it plays an important role in electronic dynamics. Our discussion is based on a nonadiabatic extension of the electronic wavefunction similar in idea to the complete adiabatic formalism developed by Nafie [J. Chem. Phys. 79, 4950 (1983)], which has also recently been reformulated by Patchkovskii [J. Chem. Phys. 137, 084109 (2012)]. We give straightforward proof of the theoretical assertion presented by Nafie using a time-dependent mixed quantum–classical framework and a standard perturbation expansion. Explicitly taking account of the flux conservation, we show that the nonadiabatically induced flux realizes the adiabatic time evolution of the electronic density. In other words, the divergence of the nonadiabatic flux equals the time derivative of the electronic density along an adiabatic time evolution of the target molecule. The second issue is about the accurate computationability of the flux. The calculation of flux needs an accurate representation of the (relative) quantum phase, in addition to the amplitude factor, of a total wavefunction and demands special attention for practical calculations. This paper is the first one to approach this issue directly and show how the difficulties arise explicitly. In doing so, we reveal that a number of widely accepted truncation techniques for static property calculations are potential sources of numerical flux non-conservation. We also theoretically propose alternative strategies to realize better flux conservation.
Structure and activity of SLAC1 channels for stomatal signaling in leaves
Authors: Deng Ya-nan , Kashtoh Hamdy , Wang Quan , Zhen Guang-xiao , Li Qi-yu , Tang Ling-hui , Gao Hai-long , Zhang Chun-rui , Qin Li , Su Min , Li Fei , Huang Xia-he , Wang Ying-chun , Xie Qi , Clarke Oliver B. , Hendrickson Wayne A. , Chen Yu-hang
Published: April 2021

Significance

Stomatal openings in plant leaves admit CO
2
and release water vapor between plant and atmosphere. Environmental stimuli such as darkness or dryness lead to closure, whereas light or low CO
2
stimulate opening. Each stoma is defined by a pair of guard cells, and its pore aperture is controlled by ion channels that regulate the turgor pressure in these cells. SLAC1 anion channels are of central importance here, and environmental factors affect channel activity by controlling SLAC1 phosphorylation. Our studies define multiple sites of regulatory phosphorylation in the context of an atomic structure of the SLAC1 channel, providing a mechanistic understanding of the fine-tuning of channel activity and thereby of stomatal apertures in response to the environment.
Hamaspora acutissima.
Authors:   USA, USDA-ARS
Published: April 2021

There is little published information on this plant pathogenic fungus, which has limited geographic distribution. As hosts exist in other regions of the world with similar environmental conditions, this species may pose a threat to native or agricultural plants if introduced.
Phragmidium kamtschatkae.
Authors:   USA, USDA-ARS
Published: April 2021

There is little published information on this plant pathogenic fungus, which has limited geographic distribution. As hosts exist in other regions of the world with similar environmental conditions, this species may pose a threat to native or agricultural plants if introduced.
Candidatus Liberibacter solanacearum (zebra chip).
Authors: Munyaneza Joseph E
Published: April 2021

Candidatus Liberibacter solanacearum (Lso) is a phloem-limited, Gram-negative, unculturable bacterium that is primarily spread by psyllid insect vectors. It is considered very invasive due to its ability to be transported primarily in infective psyllids (Munyaneza et al., 2007a; 2010a,b; 2012a,b; Munyaneza, 2012; Alfaro-Fernandez et al., 2012a,b). It has been shown that Lso distribution in the Americas, New Zealand and Europe follows the distribution of its known psyllid vectors (Munyaneza, 2010; 2012).In New Zealand, where Lso was introduced along with Bactericera cockerelli, supposedly from Western USA in early 2000s, the bacterium had already spread to both North and South Island by the time it was first documented in 2006 (Gill, 2006). It is clear that introduction of the psyllid vectors of Lso into new regions is likely to result in the rapid spread of this bacterium. Lso and several of its vectors are already on several alert lists, including the EPPO A1 Regulated Quarantine Plant Pests.
Citrus tristeza virus (citrus tristeza).
Authors: Cambra Mariano
Published: April 2021

CTV is the most economically important virus pathogen of citrus worldwide. About 100 million citrus trees on sour orange have been killed by CTV decline epidemics in Argentina, Brazil, Venezuela, Peru, Florida and California (USA), Israel, Spain, and other locations. With current estimates of approximately 45 million trees on sour orange killed by CTV in Spain (Cambra et al., 2000a; Vidal et al., 2012) from 1935 to date without T. citricida implication. It is estimated that worldwide, mainly in the Mediterranean basin citrus industries, there are over 200 million trees on sour orange rootstock which are at risk to this disease. Sour orange is popular because it produces a vigorous tree with high quality fruit, is adaptable to many soil conditions including high lime and salt content, and has tolerance to many other viruses, viroids and virus-like pathogens, and to Phytophthora. The use of tristeza-tolerant rootstocks often risks losses from other factors. In addition to decline, many severe CTV isolates cause stem pitting diseases of susceptible scion cultivars and these occur even when tolerant rootstocks are used. Stem pitting weakens trees and eventually reduces fruit size, quality and quantity (Marais et al., 1996). Grapefruit and lime are very sensitive to stem pitting. Sweet orange is more tolerant but can be severely affected by some isolates. Mandarin is the most tolerant among the main citrus cultivars against SP isolates.
Altered selection on a single self-ligand promotes susceptibility to organ-specific T cell infiltration
Authors: Klawon David E.J. , Gilmore Dana C. , Leonard John D. , Miller Christine H. , Chao Jaime L. , Walker Matthew T. , Duncombe Ryan K. , Tung Kenneth S. , Adams Erin J. , Savage Peter A.
Published: April 2021

For the large array of self-peptide/MHC class II (pMHC-II) complexes displayed in the body, it is unclear whether CD4+ T cell tolerance must be imparted for each individual complex or whether pMHC-II–nonspecific bystander mechanisms are sufficient to confer tolerance by acting broadly on T cells reactive to multiple self-pMHC-II ligands. Here, via reconstitution of T cell–deficient mice, we demonstrate that altered T cell selection on a single prostate-specific self-pMHC-II ligand renders recipient mice susceptible to prostate-specific T cell infiltration. Mechanistically, this self-pMHC-II complex is required for directing antigen-specific cells into the Foxp3+ regulatory T cell lineage but does not induce clonal deletion to a measurable extent. Thus, our data demonstrate that polyclonal T reg cells are unable to functionally compensate for a breach in tolerance to a single self-pMHC-II complex in this setting, revealing vulnerabilities in antigen-nonspecific bystander mechanisms of immune tolerance.
Ptpn2 and KLRG1 regulate the generation and function of tissue-resident memory CD8+ T cells in skin
Authors: Hochheiser Katharina , Wiede Florian , Wagner Teagan , Freestone David , Enders Matthias H. , Olshansky Moshe , Russ Brendan , Nüssing Simone , Bawden Emma , Braun Asolina , Bachem Annabell , Gressier Elise , McConville Robyn , Park Simone L. , Jones Claerwen M. , Davey Gayle M. , Gyorki David E. , Tscharke David , Parish Ian A. , Turner Stephen , Herold Marco J. , Tiganis Tony , Bedoui Sammy , Gebhardt Thomas
Published: April 2021

Tissue-resident memory T cells (TRM cells) are key elements of tissue immunity. Here, we investigated the role of the regulator of T cell receptor and cytokine signaling, Ptpn2, in the formation and function of TRM cells in skin. Ptpn2-deficient CD8+ T cells displayed a marked defect in generating CD69+ CD103+ TRM cells in response to herpes simplex virus type 1 (HSV-1) skin infection. This was accompanied by a reduction in the proportion of KLRG1− memory precursor cells and a transcriptional bias toward terminal differentiation. Of note, forced expression of KLRG1 was sufficient to impede TRM cell formation. Normalizing memory precursor frequencies by transferring equal numbers of KLRG1− cells restored TRM generation, demonstrating that Ptpn2 impacted skin seeding with precursors rather than downstream TRM cell differentiation. Importantly, Ptpn2-deficient TRM cells augmented skin autoimmunity but also afforded superior protection from HSV-1 infection. Our results emphasize that KLRG1 repression is required for optimal TRM cell formation in skin and reveal an important role of Ptpn2 in regulating TRM cell functionality.
BFAR coordinates TGFβ signaling to modulate Th9-mediated cancer immunotherapy
Authors: Pei Siyu , Huang Mingzhu , Huang Jia , Zhu Xiaodong , Wang Hui , Romano Simona , Deng Xiuyu , Wang Yan , Luo Yixiao , Hao Shumeng , Xu Jing , Yu Tao , Zhu Qingchen , Yuan Jia , Shen Kunwei , Liu Zhiqiang , Hu Guohong , Peng Chao , Luo Qingquan , Wen Zhenzhen , Dai Dongfang , Xiao Yichuan
Published: April 2021

TGFβ is essential for the generation of anti-tumor Th9 cells; on the other hand, it causes resistance against anti-tumor immunity. Despite recent progress, the underlying mechanism reconciling the double-edged effect of TGFβ signaling in Th9-mediated cancer immunotherapy remains elusive. Here, we find that TGFβ-induced down-regulation of bifunctional apoptosis regulator (BFAR) represents the key mechanism preventing the sustained activation of TGFβ signaling and thus impairing Th9 inducibility. Mechanistically, BFAR mediates K63-linked ubiquitination of TGFβR1 at K268, which is critical to activate TGFβ signaling. Thus, BFAR deficiency or K268R knock-in mutation suppresses TGFβR1 ubiquitination and Th9 differentiation, thereby inhibiting Th9-mediated cancer immunotherapy. More interestingly, BFAR-overexpressed Th9 cells exhibit promising therapeutic efficacy to curtail tumor growth and metastasis and promote the sensitivity of anti–PD-1–mediated checkpoint immunotherapy. Thus, our findings establish BFAR as a key TGFβ-regulated gene to fine-tune TGFβ signaling that causes Th9 induction insensitivity, and they highlight the translational potential of BFAR in promoting Th9-mediated cancer immunotherapy.
A toy model for relativistic neutrino masses
Authors: Bruce Stanley A.
Published: April 2021

We propose a toy model to study Dirac charged leptons and their associated antineutrinos in the presence of a homogeneous magnetic field within the framework of relativistic quantum mechanics. The discussion is kept concrete by reducing the space dimensions to 2, considering ‘spinless antineutrinos’ in 2 + 1 space-time dimensions. Solutions to specific problems in particle physics are often hindered by the technical complexities encountered in

3
+
1

-dimensions. In such cases, it is convenient to have a lower space dimensional model at ones disposal that captures some physical features while reducing technical difficulties to a minimum. The content of this article is suitable for graduate students in theoretical and experimental particle physics.
High-buckled

3×3

stanene with a topologically nontrivial energy gap
Authors: Song Ye-Heng , Wang Zhi-Wen , Jia Zhen-Yu , Zhu Xin-Yang , Shi Zhi-Qiang , Zhu Li , Yuan Qian-Qian , Shu Da-Jun , Li Shao-Chun
Published: April 2021

We demonstrate an efficient way of tuning the atomic buckling in stanene to open a topologically nontrivial energy gap. By tuning the growth kinetics, we obtain an unexpected high-buckled

3

×

3

stanene on the Bi(111) substrate. Scanning tunneling microscopy study combined with density functional theory calculation confirms that the

3

×

3

stanene is a distorted 1 × 1 structure with a high-buckled Sn in every three 1 × 1 unit cells. The high-buckled

3

×

3

stanene favors a large band inversion at the Γ point, and the spin–orbit coupling opens a topologically nontrivial energy gap. This study provides an alternate way to tune the topology of monolayer topological materials.
Anomalous hybridization complementation effect on phonon transport in heterogeneous nanowire cross junction
Authors: Ma Dengke , Zhao Yunshan , Zhang Lifa
Published: April 2021

Controlling phonon transport via its wave nature in nanostructures can achieve unique properties for various applications. In this paper, thermal conductivity of heterogeneous nano cross junction (hetero-NCJ) is studied through molecular dynamics simulation. It is found that decreasing or increasing the atomic mass of four side wires (SWs) severed as resonators, thermal conductivity of hetero-NCJ is enhanced, which is larger than that of homogeneous NCJ (homo-NCJ). Interestingly, by setting two SWs with larger atomic mass and other two SWs with smaller atomic mass, thermal conductivity of hetero-NCJ is abnormally decreased, which is even smaller than that of homo-NCJ. After further non-equilibrium Green’s function calculations, it is demonstrated that origin of increase is attributed to the hybridization broken induced by unidirectional shift of resonant modes. However, the decrease in thermal conductivity originates from hybridization complementation induced by bidirectional shift of resonant modes, which synergistically blocks phonon transport. This work provides a mechanism for further strengthening resonant hybridization effect and manipulating thermal transport.
Automated image analysis for quantification of materials microstructure evolution
Authors: Ahmed Mansur , Horst Oliver Martin , Obaied Abdulmonem , Steinbach Ingo , Roslyakova Irina
Published: April 2021

In this work, an automated image analysis procedure for the quantification of microstructure evolution during creep is proposed for evaluating scanning electron microscopy micrographs of a single crystal Ni-based superalloy before and after creep at 950 °C and 350 MPa. scanning electron microscopy-micrographs of γ/γ′ microstructures are transformed into binary images. Image analysis, which involves pixel by pixel classification and feature extraction, is then combined with a supervised machine learning algorithm to improve the binarization and the quality of the results. The binarization of the gray scale images is not always straight forward, especially when the difference in gray levels between the γ-channels and the γ′-phase is small. To optimize feature extraction, we utilized a series of bilateral filters as well as a machine learning algorithm, known as the gradient boosting method, that was used for training and classifying the micrograph pixels. After testing the two methods, the gradient boosting method was identified as the most effective. Subsequently, a Python routine was written and implemented for the automated quantification of the γ′ area fraction and the γ channel width. Our machine learning method is documented and the results of the automatic procedure are discussed based on results which we previously reported in the literature.
Theoretical study of the critical dynamic behaviors for pore collapse in explosive
Authors: Long Yao , Chen Jun
Published: April 2021

The shock loading process of porous explosive is simulated by molecular dynamics for different pore diameters and piston velocities. We find that the defect evolution consists of three steps: pore collapse, stress relaxation and hot spot evolution. The critical dynamic behaviors for each step are investigated. First, at the pore collapse process, the shock wave reflected at pore face induces rarefaction waves. Two reflection types are considered: downside face reflection and upside face reflection. The wave reflection equations are derived. Second, at the stress relaxation process, a spherical rebounding wave is obtained. For low spherical radius, the rebounding wave is supersonic; and for high spherical radius, the rebounding wave is sonic. The propagation of rebounding wave is an adiabatic expansion process for hot spot, therefore, the hot spot temperature decreases quickly at this stage. Third, by considering the thermal diffusion and thermal decomposition effects, the hot spot ignition equation is derived, and the critical temperature for ignition is evaluated. A complete physical picture of defect evolution is obtained.
Interlayer exchange couple based reliable and robust 3-input adder design methodology
Authors: Mattela Venkat , Debroy Sanghamitra , Sivasubramani Santhosh , Acharyya Amit
Published: April 2021

In this paper, a novel inter-layer exchange coupled (IEC) based 3-input full adder design methodology is proposed and subsequently the architecture has been implemented on the widely accepted micromagnetic OOMMF platform. The impact of temperature on the IEC coupled full-adder design has been analyzed up to Curie temperature. It was observed that even up to Curie temperature the IEC based adder design was able to operate at sub-50 nm as contrast to dipole coupled adder design which failed at 5 K for sub 50 nm. Simulation results obtained from OOMMF micromagnetic simulator shows, the IEC based adder design was at a lower energy state as compared to the dipole coupled adder indicating a more stable system and as the temperature of the design was increased, the total energy increased resulting in reduced stability. Potential explanation for the thermodynamic stability of IEC model lies in its energetically favored architecture, such that the total energy was lower than its dipole coupled counterparts. IEC architecture demonstrates supremacy in reliability and strength enabling NML to march towards beyond CMOS devices.
Superman vs momentum
Authors: Kızılcık Hasan Şahin
Published: April 2021

The purpose of this study is to consider Superman’s acts against impulse–momentum and conservation of momentum principles. Superheroes as fantasy fiction characters attract the attention of not only children and teenagers but also adults. Superheroes can be useful in explaining a phenomenon, as well as overcoming conceptual difficulties that may occur in students. Superman is a superhero who often challenges the impulse–momentum principle and conservation of momentum. Therefore, he may be the best superhero to use when talking about momentum. This context gives educators an opportunity to motivate students.
Study of fluid motion in different configurations and temperatures
Authors: Wadhwa Ajay
Published: April 2021

We have investigated the motion of water flow through glass tubes of different shapes by calculating the value of the Reynolds number denoted as

Re

. We know that at a given flow rate the value of

Re

determines the type of flow being classified as laminar, transitional or tubulent. The dependence of

Re

in different configurations of glass tubes as well as on temperature is investigated. The apparatus for the experiment is designed in the undergraduate laboratory and the conventional method of measuring the flow rate using a dye for detecting the type of flow is used.
Head and neck multi-organ segmentation on dual-energy CT using dual pyramid convolutional neural networks
Authors: Wang Tonghe , Lei Yang , Roper Justin , Ghavidel Beth , Beitler Jonathan J , McDonald Mark , Curran Walter J , Liu Tian , Yang Xiaofeng
Published: April 2021

Organ delineation is crucial to diagnosis and therapy, while it is also labor-intensive and observer-dependent. Dual energy CT (DECT) provides additional image contrast than conventional single energy CT (SECT), which may facilitate automatic organ segmentation. This work aims to develop an automatic multi-organ segmentation approach using deep learning for head-and-neck region on DECT. We proposed a mask scoring regional convolutional neural network (R-CNN) where comprehensive features are firstly learnt from two independent pyramid networks and are then combined via deep attention strategy to highlight the informative ones extracted from both two channels of low and high energy CT. To perform multi-organ segmentation and avoid misclassification, a mask scoring subnetwork was integrated into the Mask R-CNN framework to build the correlation between the class of potential detected organ’s region-of-interest (ROI) and the shape of that organ’s segmentation within that ROI. We evaluated our model on DECT images from 127 head-and-neck cancer patients (66 training, 61 testing) with manual contours of 19 organs as training target and ground truth. For large- and mid-sized organs such as brain and parotid, the proposed method successfully achieved average Dice similarity coefficient (DSC) larger than 0.8. For small-sized organs with very low contrast such as chiasm, cochlea, lens and optic nerves, the DSCs ranged between around 0.5 and 0.8. With the proposed method, using DECT images outperforms using SECT in almost all 19 organs with statistical significance in DSC (p<0.05). Meanwhile, by using the DECT, the proposed method is also significantly superior to a recently developed FCN-based method in most of organs in terms of DSC and the 95th percentile Hausdorff distance. Quantitative results demonstrated the feasibility of the proposed method, the superiority of using DECT to SECT, and the advantage of the proposed R-CNN over FCN on the head-and-neck patient study. The proposed method has the potential to facilitate the current head-and-neck cancer radiation therapy workflow in treatment planning.
A novel magnetorheological fluid damper with a heat insulation function
Authors: Du Chengbin , Zeng Fanang , Liu Bing , Fu Yankai
Published: April 2021

A novel magnetorheological fluid (MRF) damper was designed by adding an aluminium foil bubble insulation material with a low thermal conductivity in the cavity between the electromagnetic coil and the MRF to avoid a rapid rise in the temperature of the MRF in the working process of the damper. First, the rheological properties of the MRF at different temperatures were tested by a rheometer, squeezing and stretching tests of the MRF at different temperatures were carried out by a test machine, and the relationship between the dynamic viscosity and the shear stress, squeezing stress, stretching stress and temperature was obtained experimentally. Second, a new type of MRF damper was designed, and a corresponding numerical simulation was carried out to study the effect of this heat insulation on the temperature field and the damping effect under different electromagnetic coil temperatures. The results show that the rate of increase in the MRF temperature in the working area of the damper with the insulation material could be reduced by 57.4% compared to that of the damper without the insulation material. At the same time, the damping force increased greatly. The rate of increase in the rebound force was 12.0% ∼ 40.0%, the rate of increase in the compression force was 11.0% ∼ 39.9%, and the magnitude of increase increased with the frequency, amplitude and temperature. Finally, the damper was experimentally studied, and the numerical simulation results were consistent with the experimental results.
Oxygen out-diffusion in REBCO coated conductor due to heating
Authors: Lu Jun , Xin Yan , Jarvis Brent , Bai Hongyu
Published: April 2021

Rare earth barium copper oxide (REBCO) coated conductor has emerged as one of the high T
c superconductors suitable for future ultrahigh field superconducting magnet applications. In the design and fabrication of such ultrahigh field REBCO magnets, it is essential to understand the behavior of REBCO coated conductor. The effect of heating on the properties of commercial REBCO coated conductors is very important for many practical reasons. Nevertheless, a comprehensive study on this effect have not yet been presented in the published literature. This work studies a commercial REBCO coated conductor heat-treated at temperatures between 175 °C and 300 °C for various durations. Critical current and lap joint resistivity were measured at 77 K and 4.2 K for the heat-treated samples. We found that critical current degrades with heat treatment time and temperature. This degradation can be described by a one-dimensional oxygen out-diffusion model with a diffusion coefficient of D = 2.5 × 10−6 exp (−1.17eV kT−1) m2 s−1. The heat treatment also causes appreciable increase in joint resistivity. Comprehensive structural and chemical analyses were performed on Cu/Ag/RECBO interfaces by transmission electron microscopy. Our electron energy loss spectroscopy study provided direct evidence of oxygen deficiency in the heat treated REBCO samples. In addition, it is found that the oxygen diffused out of the REBCO layer forms mostly Cu2O at both Ag/REBCO and Cu/Ag interfaces. Cu2O is also observed at grain boundaries of the Ag layer. The oxygen out-diffusion model proposed in this work is used to predict REBCO thermal degradation in several engineering scenarios.