bluuebunny/crossref_metadata_2025 huggingface dataset:
A hidden Markov model for lymphatic tumor progression in the head and neck
Authors: Ludwig Roman , Pouymayou Bertrand , Balermpas Panagiotis , Unkelbach Jan
Published: June 2021

Currently, elective clinical target volume (CTV-N) definition for head and neck squamous cell carcinoma (HNSCC) is mostly based on the prevalence of nodal involvement for a given tumor location. In this work, we propose a probabilistic model for lymphatic metastatic spread that can quantify the risk of microscopic involvement in lymph node levels (LNL) given the location of macroscopic metastases and T-category. This may allow for further personalized CTV-N definition based on an individual patient’s state of disease. We model the patient's state of metastatic lymphatic progression as a collection of hidden binary random variables that indicate the involvement of LNLs. In addition, each LNL is associated with observed binary random variables that indicate whether macroscopic metastases are detected. A hidden Markov model (HMM) is used to compute the probabilities of transitions between states over time. The underlying graph of the HMM represents the anatomy of the lymphatic drainage system. Learning of the transition probabilities is done via Markov chain Monte Carlo sampling and is based on a dataset of HNSCC patients in whom involvement of individual LNLs was reported. The model is demonstrated for ipsilateral metastatic spread in oropharyngeal HNSCC patients. We demonstrate the model's capability to quantify the risk of microscopic involvement in levels III and IV, depending on whether macroscopic metastases are observed in the upstream levels II and III, and depending on T-category. In conclusion, the statistical model of lymphatic progression may inform future, more personalized, guidelines on which LNL to include in the elective CTV. However, larger multi-institutional datasets for model parameter learning are required for that.
Genome-wide characterization of peptidyl-prolyl cis–trans isomerases in Penicillium and their regulation by salt stress in a halotolerant P. oxalicum
Authors: Singh Mangaljeet , Kaur Kirandeep , Sharma Avinash , Kaur Rajvir , Joshi Dimple , Chatterjee Megha , Dandapath Iman , Kaur Amarjeet , Singh Harpreet , Singh Prabhjeet
Published: June 2021

Peptidyl-prolyl cis–trans isomerases (PPIases) are the only class of enzymes capable of cis–trans isomerization of the prolyl peptide bond. The PPIases, comprising of different families viz., cyclophilins, FK506-binding proteins (FKBPs), parvulins and protein phosphatase 2A phosphatase activators (PTPAs), play essential roles in different cellular processes. Though PPIase gene families have been characterized in different organisms, information regarding these proteins is lacking in Penicillium species, which are commercially an important fungi group. In this study, we carried out genome-wide analysis of PPIases in different Penicillium spp. and investigated their regulation by salt stress in a halotolerant strain of Penicillium oxalicum. These analyses revealed that the number of genes encoding cyclophilins, FKBPs, parvulins and PTPAs in Penicillium spp. varies between 7–11, 2–5, 1–2, and 1–2, respectively. The halotolerant P. oxalicum depicted significant enhancement in the mycelial PPIase activity in the presence of 15% NaCl, thus, highlighting the role of these enzymes in salt stress adaptation. The stress-induced increase in PPIase activity at 4 and 10 DAI in P. oxalicum was associated with higher expression of PoxCYP18. Characterization of PPIases in Penicillium spp. will provide an important database for understanding their cellular functions and might facilitate their applications in industrial processes through biotechnological interventions.
Author Correction: Simulation of the Bell inequality violation based on quantum steering concept
Authors: Ruzbehani Mohsen
Published: June 2021

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
A printed millimetre-wave modulator and antenna array for backscatter communications at gigabit data rates
Authors: Kimionis John , Georgiadis Apostolos , Daskalakis Spyridon Nektarios , Tentzeris Manos M.
Published: June 2021

Future devices for the Internet of Things will require communication systems that can deliver higher data rates at low power. Backscatter radio—in which wireless communication is achieved via reflection rather than radiation—is a low-complexity approach that requires a minimal number of active elements. However, it is typically limited to data rates of hundreds of megabits per second because of the low frequency bands used and the modulation techniques involved. Here we report a millimetre-wave modulator and antenna array for backscatter communications at gigabit data rates. This radiofrequency front-end consists of a microstrip patch antenna array and a single pseudomorphic high-electron-mobility transistor that supports a range of modulation formats including binary phase shift keying, quadrature phase shift keying and quadrature amplitude modulation. The circuit is additively manufactured with inkjet printing using silver nanoparticle inks on a flexible liquid-crystal polymer substrate. A millimetre-wave transceiver is also designed to capture and downconvert the backscattered signals and route them for digital signal processing. With the system, we demonstrate a bit rate of two gigabits per second of backscatter transmission at millimetre-wave frequencies of 24–28 GHz, and with a front-end energy consumption of 0.17 pJ per bit.
Macropinocytosis requires Gal-3 in a subset of patient-derived glioblastoma stem cells
Authors: Seguin Laetitia , Odouard Soline , Corlazzoli Francesca , Haddad Sarah Al , Moindrot Laurine , Calvo Tardón Marta , Yebra Mayra , Koval Alexey , Marinari Eliana , Bes Viviane , Guérin Alexandre , Allard Mathilde , Ilmjärv Sten , Katanaev Vladimir L. , Walker Paul R. , Krause Karl-Heinz , Dutoit Valérie , Sarkaria Jann N. , Dietrich Pierre-Yves , Cosset Érika
Published: June 2021

Recently, we involved the carbohydrate-binding protein Galectin-3 (Gal-3) as a druggable target for KRAS-mutant-addicted lung and pancreatic cancers. Here, using glioblastoma patient-derived stem cells (GSCs), we identify and characterize a subset of Gal-3high glioblastoma (GBM) tumors mainly within the mesenchymal subtype that are addicted to Gal-3-mediated macropinocytosis. Using both genetic and pharmacologic inhibition of Gal-3, we showed a significant decrease of GSC macropinocytosis activity, cell survival and invasion, in vitro and in vivo. Mechanistically, we demonstrate that Gal-3 binds to RAB10, a member of the RAS superfamily of small GTPases, and β1 integrin, which are both required for macropinocytosis activity and cell survival. Finally, by defining a Gal-3/macropinocytosis molecular signature, we could predict sensitivity to this dependency pathway and provide proof-of-principle for innovative therapeutic strategies to exploit this Achilles’ heel for a significant and unique subset of GBM patients.
Chiroptical activity of hydroxycarboxylic acids with implications for the origin of biological homochirality
Authors: Bocková Jana , Jones Nykola C. , Meierhenrich Uwe J. , Hoffmann Søren V. , Meinert Cornelia
Published: June 2021

Circularly polarised light (CPL) interacting with interstellar organic molecules might have imparted chiral bias and hence preluded prebiotic evolution of biomolecular homochirality. The l-enrichment of extra-terrestrial amino acids in meteorites, as opposed to no detectable excess in monocarboxylic acids and amines, has previously been attributed to their intrinsic interaction with stellar CPL revealed by substantial differences in their chiroptical signals. Recent analyses of meteoritic hydroxycarboxylic acids (HCAs) – potential co-building blocks of ancestral proto-peptides – indicated a chiral bias toward the l-enantiomer of lactic acid. Here we report on novel anisotropy spectra of several HCAs using a synchrotron radiation electronic circular dichroism spectrophotometer to support the re-evaluation of chiral biomarkers of extra-terrestrial origin in the context of absolute photochirogenesis. We found that irradiation by CPL which would yield l-excess in amino acids would also yield l-excess in aliphatic chain HCAs, including lactic acid and mandelic acid, in the examined conditions. Only tartaric acid would show “unnatural” d-enrichment, which makes it a suitable target compound for further assessing the relevance of the CPL scenario.
Charge density waves and their transitions in anisotropic quantum Hall systems
Authors: He Yuchi , Yang Kang , Goerbig Mark Oliver , Mong Roger S. K.
Published: June 2021

In recent experiments, external anisotropy has been a useful tool to tune different phases and study their competitions. In this paper, we look at the quantum Hall charge density wave states in the N = 2 Landau level. Without anisotropy, there are two first-order phase transitions between the Wigner crystal, the 2-electron bubble phase, and the stripe phase. By adding mass anisotropy, our analytical and numerical studies show that the 2-electron bubble phase disappears and the stripe phase significantly enlarges its domain in the phase diagram. Meanwhile, a regime of stripe crystals that may be observed experimentally is unveiled after the bubble phase gets out. Upon increase of the anisotropy, the energy of the phases at the transitions becomes progressively smooth as a function of the filling. We conclude that all first-order phase transitions are replaced by continuous phase transitions, providing a possible realisation of continuous quantum crystalline phase transitions.
Coherently amplifying photon production from vacuum with a dense cloud of accelerating photodetectors
Authors: Wang Hui , Blencowe Miles
Published: June 2021

An accelerating photodetector is predicted to see photons in the electromagnetic vacuum. However, the extreme accelerations required have prevented the direct experimental verification of this quantum vacuum effect. In this work, we consider many accelerating photodetectors that are contained within an electromagnetic cavity. We show that the resulting photon production from the cavity vacuum can be collectively enhanced such as to be measurable. The combined cavity-photodetectors system maps onto a parametrically driven Dicke-type model; when the detector number exceeds a certain critical value, the vacuum photon production undergoes a phase transition from a normal phase to an enhanced superradiant-like, inverted lasing phase. Such a model may be realized as a mechanical membrane with a dense concentration of optically active defects undergoing gigahertz flexural motion within a superconducting microwave cavity. We provide estimates suggesting that recent related experimental devices are close to demonstrating this inverted, vacuum photon lasing phase.
Engineering chemical communication between micro/nanosystems
Authors: de Luis Beatriz , Llopis-Lorente Antoni , Sancenón Félix , Martínez-Máñez Ramón
Published: June 2021

This review covers recent developments in the engineering of chemical communication between micro/nanosystems as a key emergent topic in micro/nanotechnology, biomimicry and related areas.
Variable stoichiometry cocrystals: occurrence and significance
Authors: Saikia Basanta , Pathak Debabrat , Sarma Bipul
Published: June 2021

Stoichiometric variation in organic cocrystals, their synthesis, structure elucidation and properties are discussed. Accountable reasons for the occurrence of such cocrystals are emphasised.
Transient FTIR spectroscopy after one- and two-colour excitation on a highly luminescent chromium(iii) complex
Authors: Boden Pit , Di Martino-Fumo Patrick , Niedner-Schatteburg Gereon , Seidel Wolfram , Heinze Katja , Gerhards Markus
Published: June 2021

Depending on the energy of the near-IR photon, the lowest emissive state of the molecular ruby is depopulated or populated.
Optimising air quality co-benefits in a hydrogen economy: a case for hydrogen-specific standards for NOx emissions
Authors: Lewis Alastair C.
Published: June 2021

Hydrogen may play a major role as an energy source to support net zero but combustion leads to emissions of NOx, a key air pollutant. Delivering optimal air quality co-benefits may need more ambitious hydrogen-specific emission standards developing.
Melt-reprocessing of mixed polyurethane thermosets
Authors: Khan Ajmir , Naveed Muhammad , Rabnawaz Muhammad
Published: June 2021

Herein we have developed melt-reprocessing of mixed aromatic and aliphatic polyurethanes (PUR) thermosets. This study will enable post-consumer mixed PURs with immense benefits for science, the economy, and the environment.
Lithium ion battery recycling using high-intensity ultrasonication
Authors: Lei Chunhong , Aldous Iain , Hartley Jennifer M. , Thompson Dana L. , Scott Sean , Hanson Rowan , Anderson Paul A. , Kendrick Emma , Sommerville Rob , Ryder Karl S. , Abbott Andrew P.
Published: June 2021

Electric vehicle battery electrodes are delaminated ultra-fast using high-powered ultrasound, separating active materials from the foil current collectors.
Effect of C12H25O– substituent position on the self-assembly behaviour of C6H5COO–Ala–Ala dipeptide
Authors: Lin Shuwei , Tong Qiyun , Jiang Pan , Li Baozong , Li Yi , Yang Yonggang
Published: June 2021

Intramolecular hydrogen bonding and steric hindrance of side chain lead the different molecular packing of dipeptides and the morphological transformation of self-assemblies’ nanostructures.
Ferrocene-appended boronated ester: effect of cyanovinylene group on the nonlinear optical properties and colorimetric detection of fluoride ion
Authors: Viswanathan Thamodharan , Palanisami Nallasamy
Published: June 2021

A centrosymmetric ferrocenyl boronated ester shows second-order NLO effect, selective and sensitive detection of fluoride ion.
Core-functionalized nanoaggregates: preparation via polymerization-induced self-assembly and their applications
Authors: Damsongsang Panittha , Hoven Voravee P. , Yusa Shin-ichi
Published: June 2021

Core-functionalized nanoaggregates can be prepared by a combination of polymerization-induced self-assembly (PISA) and post-polymerization modification.
Elemental mapping of half-sandwich azopyridine osmium arene complexes in cancer cells
Authors: Bolitho Elizabeth M. , Bridgewater Hannah E. , Needham Russell J. , Coverdale James P. C. , Quinn Paul D. , Sanchez-Cano Carlos , Sadler Peter J.
Published: June 2021

Nanofocused synchrotron X-ray fluorescence and inductively coupled plasma-mass spectrometry provide insights into time-dependent ligand exchange reactions of organo-osmium anticancer complexes in cancer cells. Created with Biorender.com.
Dual anionic substitution engineering for an advanced NASICON phosphate cathode in sodium-ion batteries
Authors: Zhao Xin-Xin , Gu Zhen-Yi , Guo Jin-Zhi , Zhao Chen-De , Wang Xiao-Tong , Xie Dan , Li Wen-Hao , Wu Xing-Long
Published: June 2021

Dual anionic substitution materials of Na3V2(PO4)2O2−2xF1+2x are prepared using the solid-state method, and the regulation mechanism of different F/O ratios is studied by analyzing the structural evolution, electrochemical performance and reaction kinetics.
Regulating the adsorption behavior of intermediates on Ir–W@Ir–WO3−x boosts acidic water oxidation electrocatalysis
Authors: Lu Zheng , Wei Cong , Liu Xinmiao , Fang Yanyan , Hao Xiaobin , Zang Yipeng , Pei Zhibin , Cai Jinyan , Wu Yishang , Niu Di , Mosallanezhad Amirabbas , Sun Da , Ye Jian , Niu Shuwen , Wang Gongming
Published: June 2021

The activity and stability toward acidic water oxidation on Ir–W@Ir–WO3−x can be boosted by regulating the adsorption behavior of oxygen-containing intermediates.
Nano beta zeolites catalytic-cracking effect on hydrochlorofluorocarbon molecule for specific detection of Freon
Authors: Wang Xueqing , Xu Pengcheng , Tang Lei , Chen Ying , Li Xinxin
Published: June 2021

Nano beta zeolite is innovatively used for catalytic-cracking of Freon R22 molecules, the catalytic products (i.e., ˙CCl3) are detectable using a ZnO gas sensor.
Structural self-sorting of pseudopeptide homo and heterodimeric disulfide cages in water: mechanistic insights and cation sensing
Authors: Konopka Marcin , Cecot Piotr , Harrowfield Jack M. , Stefankiewicz Artur R.
Published: June 2021

Water-soluble, multi-component disulfide cages showing a self-sorting behavior and cation sensing ability.
Bacteria autoaggregation: how and why bacteria stick together
Authors: Nwoko El-shama Q. A. , Okeke Iruka N.
Published: June 2021

Autoaggregation, adherence between identical bacterial cells, is important for colonization, kin and kind recognition, and survival of bacteria. It is directly mediated by specific interactions between proteins or organelles on the surfaces of interacting cells or indirectly by the presence of secreted macromolecules such as eDNA and exopolysaccharides. Some autoaggregation effectors are self-associating and present interesting paradigms for protein interaction. Autoaggregation can be beneficial or deleterious at specific times and niches. It is, therefore, typically regulated through transcriptional or post-transcriptional mechanisms or epigenetically by phase variation. Autoaggregation can contribute to bacterial adherence, biofilm formation or other higher-level functions. However, autoaggregation is only required for these phenotypes in some bacteria. Thus, autoaggregation should be detected, studied and measured independently using both qualitative and quantitative in vitro and ex vivo methods. If better understood, autoaggregation holds the potential for the discovery of new therapeutic targets that could be cost-effectively exploited.
Detergent-free systems for structural studies of membrane proteins
Authors: Guo Youzhong
Published: June 2021

Membrane proteins play vital roles in living organisms, serving as targets for most currently prescribed drugs. Membrane protein structural biology aims to provide accurate structural information to understand their mechanisms of action. The advance of membrane protein structural biology has primarily relied on detergent-based methods over the past several decades. However, detergent-based approaches have significant drawbacks because detergents often damage the native protein–lipid interactions, which are often crucial for maintaining the natural structure and function of membrane proteins. Detergent-free methods recently have emerged as alternatives with a great promise, e.g. for high-resolution structure determinations of membrane proteins in their native cell membrane lipid environments. This minireview critically examines the current status of detergent-free methods by a comparative analysis of five groups of membrane protein structures determined using detergent-free and detergent-based methods. This analysis reveals that current detergent-free systems, such as the styrene-maleic acid lipid particles (SMALP), the diisobutyl maleic acid lipid particles (DIBMALP), and the cycloalkane-modified amphiphile polymer (CyclAPol) technologies are not better than detergent-based approaches in terms of maintenance of native cell membrane lipids on the transmembrane domain and high-resolution structure determination. However, another detergent-free technology, the native cell membrane nanoparticles (NCMN) system, demonstrated improved maintenance of native cell membrane lipids with the studied membrane proteins, and produced particles that were suitable for high-resolution structural analysis. The ongoing development of new membrane-active polymers and their optimization will facilitate the maturation of these new detergent-free systems.
Physically motivated X-ray obscurer models
Authors: Buchner Johannes , Brightman Murray , Baloković Mislav , Wada Keiichi , Bauer Franz E. , Nandra Kirpal
Published: June 2021

Context. The nuclear obscurer of active galactic nuclei (AGN) is poorly understood in terms of its origin, geometry, and dynamics.

Aims. We investigate whether physically motivated geometries emerging from hydro-radiative simulations can be differentiated with X-ray reflection spectroscopy.

Methods. For two new geometries, the radiative fountain model and a warped disk, we release spectral models produced with the ray tracing code XARS. We contrast these models with spectra of three nearby AGN taken by NuSTAR and Swift/BAT.

Results. Along heavily obscured sightlines, the models present different 4−20 keV continuum spectra. These can be differentiated by current observations. Spectral fits of the Circinus Galaxy favour the warped disk model over the radiative fountain, and clumpy or smooth torus models.

Conclusions. The necessary reflector (NH ≥ 1025 cm2) suggests a hidden population of heavily Compton-thick AGN amongst local galaxies. X-ray reflection spectroscopy is a promising pathway to understand the nuclear obscurer in AGN.
Pinpointing the jet apex of 3C 84
Authors: Paraschos G. F. , Kim J.-Y. , Krichbaum T. P. , Zensus J. A.
Published: June 2021

Nearby radio galaxies that contain jets are extensively studied with very long baseline interferometry (VLBI), addressing jet launching and the physical mechanisms at play around massive black holes. 3C 84 is unique in this regard because the combination of its proximity and large super massive black hole mass provides a high spatial resolution to resolve the complex structure at the jet base. For 3C 84, an angular scale of 50 μas corresponds to 200−250 Schwarzschild radii (Rs). Recent RadioAstron VLBI imaging at 22 GHz has revealed an east-west elongated feature at the northern end of the VLBI jet, which challenges past interpretations. Here we propose instead that the jet apex is not located within the 22 GHz VLBI core region but more upstream in the jet. We base our arguments on a 2D cross-correlation analysis of quasi-simultaneously obtained VLBI images at 15, 43, and 86 GHz, which measures the opacity shift of the VLBI core in 3C 84. With the assumption of the power-law index (kr) of the core shift being set to 1, we find the jet apex to be located 83 ± 7 μas north (upstream) of the 86 GHz VLBI core. Depending on the assumptions forkrand the particle number density power-law index,n, we find a mixed toroidal-poloidal magnetic field configuration, consistent with a region that is offset from the central engine by about 400–1500Rs. The measured core shift is then used to estimate the magnetic field strength, which amounts toB= 1.80−4.0 G near the 86 GHz VLBI core. We discuss some physical implications of these findings.
TOPoS
Authors: Bonifacio P. , Monaco L. , Salvadori S. , Caffau E. , Spite M. , Sbordone L. , Spite F. , Ludwig H.-G. , Di Matteo P. , Haywood M. , François P. , Koch-Hansen A. J. , Christlieb N. , Zaggia S.
Published: June 2021

Context. The goal of the Turn-Off Primordial Stars survey (TOPoS) project is to find and analyse turn-off (TO) stars of extremely low metallicity. To select the targets for spectroscopic follow-up at high spectral resolution, we relied on low-resolution spectra from the Sloan Digital Sky Survey (SDSS).

Aims. In this paper, we use the metallicity estimates we obtained from our analysis of the SDSS spectra to construct the metallicity distribution function (MDF) of the Milky Way, with special emphasis on its metal-weak tail. The goal is to provide the underlying distribution out of which the TOPoS sample was extracted.

Methods. We made use of SDSS photometry, Gaia photometry, and distance estimates derived from the Gaia parallaxes to derive a metallicity estimate for a large sample of over 24 million TO stars. This sample was used to derive the metallicity bias of the sample for which SDSS spectra are available.

Results. We determined that the spectroscopic sample is strongly biased in favour of metal-poor stars, as intended. A comparison with the unbiased photometric sample allows us to correct for the selection bias. We selected a sub-sample of stars with reliable parallaxes for which we combined the SDSS radial velocities with Gaia proper motions and parallaxes to compute actions and orbital parameters in the Galactic potential. This allowed us to characterise the stars dynamically, and in particular to select a sub-sample that belongs to the Gaia-Sausage-Enceladus (GSE) accretion event. We are thus also able to provide the MDF of GSE.

Conclusions. The metal-weak tail derived in our study is very similar to that derived in the H3 survey and in the Hamburg/ESO Survey. This allows us to average the three MDFs and provide an error bar for each metallicity bin. Inasmuch as the GSE structure is representative of the progenitor galaxy that collided with the Milky Way, that galaxy appears to be strongly deficient in metal-poor stars compared to the Milky Way, suggesting that the metal-weak tail of the latter has been largely formed by accretion of low-mass galaxies rather than massive galaxies, such as the GSE progenitor.
A Bayesian risk assessment of the COVID-19 pandemic using FMEA and a modified SEIR epidemic model
Authors: Koucha Yacine , Yang QingPing
Published: June 2021

The COVID-19 outbreak is of great concern due to the high rates of infection and the large number of deaths worldwide. In this paper, we considered a Bayesian inference and failure mode and effects analysis of the modified susceptible-exposed-infectious-removed model for the transmission dynamics of COVID-19 with an exponentially distributed infectious period. We estimated the effective reproduction number based on laboratory-confirmed cases and death data using Bayesian inference and analyse the impact of the community spread of COVID-19 across the United Kingdom. We used the failure mode and effects analysis tool to evaluate the effectiveness of the action measures taken to manage the COVID-19 pandemic. We focused on COVID-19 infections and therefore the failure mode is taken as positive cases. The model is applied to COVID-19 data showing the effectiveness of interventions adopted to control the epidemic by reducing the reproduction number of COVID-19. Results have shown that the combination of Bayesian inference, compartmental modelling and failure mode and effects analysis is effective in modelling and studying the risks of COVID-19 transmissions, leading to the quantitative evaluation of the action measures and the identification of the lessons learned from the governmental measures and actions taken in response to COVID-19 in the United Kingdom. Analytical and numerical methods are used to highlight the practical implications of our findings. The proposed methodology will find applications in current and future COVID-19 like pandemics and wide quality engineering.
68Ga-NeoB: Präklinische Ergebnisse zur Bildgebung gastrointestinaler Stromatumoren und zur Bestimmung der Zielrezeptordichte im Gastrointestinaltrakt
Authors: Pretze Marc , Wängler Carmen , Schönberg Stefan O. , Wängler Björn
Published: June 2021

68Ga-NeoB (früher bekannt als NeoBOMB1) ist ein neuartiger DOTA-gekoppelter Gastrin-Releasing-Peptid-Rezeptor(GRPR)-Antagonist mit hoher Bindungsaffinität zum GRPR und ausgezeichneter In-vivo-Stabilität. Ziel dieser präklinischen Studie war es, die Verwendung von 68Ga-NeoB zur Bestimmung der GRPR-Expression im Pankreasgewebe weiter zu erforschen, indem der GRPR-Sättigungsgrad im Pankreas bei der Verwendung verschiedener molarer Stoffmengen von 68Ga-NeoB geschätzt wurde. Darüber hinaus wurde 68Ga-NeoB als Tracer für gastrointestinale Stromatumoren (GIST) in 2 verschiedenen Mausstämmen untersucht. Anschließende Ex-vivo-Biodistributionsstudien mit verschiedenen Stoffmengen des antagonistischen Tracers 68Ga-NeoB mit hoher Bindungsaffinität zu GRPR wurden zur Abschätzung der Rezeptordichte in Organen oder Geweben mit hoher Expression dieses Rezeptors genutzt. Die Kombination von PET/CT und MRT-Datensätzen unterstützte die Ermittlung von Organanreicherungen auch bei Erreichen des Sättigungsgrades des Radiotracers in gastrointestinalen Organen.
Die Bedeutung des Elementes Barium in der Nuklearmedizin
Authors: Reissig Falco , Kopka Klaus , Mamat Constantin
Published: June 2021

Von Erdalkalimetallionen außer Beryllium ist bekannt, dass sie ein calcimimetisches Verhalten zeigen. Damit ist ihr Schicksal in vivo vorgezeichnet, das in einem beträchtlichen Maße durch den Einbau in Knochengewebe, welches zum Hauptteil aus Hydroxylapatit besteht, charakterisiert ist. In diesem Sinne wurde auch die Verwendung von Radionukliden dieser Elemente als Knochensucher forciert. Mit Ausnahme von Beryllium und Magnesium wurden Tierexperimente und Humananwendungen mit Radionukliden von Calcium, Strontium, Barium und Radium durchgeführt, wobei bis heute lediglich Strontium und Radium, in der Hauptsache als Therapienuklide zur palliativen Behandlung von Knochenmetastasen, Eingang in nuklearmedizinische Routineanwendungen gefunden haben. In diesem Übersichtsartikel werden die Radionuklide des Bariums vorgestellt, sowie deren Herstellung und Verwendung. Aktuelle Forschungsergebnisse mit Radionukliden des Bariums in Radiopharmazie und Nuklearmedizin werden präsentiert.
Evidence-Based Examination Techniques for the Shoulder Joint
Authors: Meder Adrian , Stefanescu Maria-Christina , Ateschrang Atesch , Froehlich Susanne , Obertacke Udo , Schulz Arndt Peter , Meyerhoff Hauke S. , Oswald Eva J. , Sterz Jasmina , Ruesseler Miriam
Published: June 2021

Objective Digitalisation now almost covers all areas of medical student teaching. Teaching videos are a good way to help students learn practical skills. The existing evidence is a recognised aid for the classification of the respective technology.

Method This video presents the usual examination techniques of the shoulder joint on a patient with an unstable shoulder. The respective techniques, if available, were backed up with appropriate evidence.

Conclusion The examination techniques presented allow students to view them in a standardized manner on a patient. The evidence for the examination techniques can help with the classification of the respective technique.
Live endoscopy events (LEEs): European Society of Gastrointestinal Endoscopy Position Statement – Update 2021
Authors: Webster George J. , El Menabawey Tareq , Arvanitakis Marianna , Hassan Cesare , van Hooft Jeanin E. , Messmann Helmut , Dinis-Ribeiro Mário
Published: June 2021

The European Society of Gastrointestinal Endoscopy (ESGE) is dedicated to improving the quality of gastrointestinal endoscopy, including through educational activities such as live endoscopy events (LEEs). The primary goal of LEEs should be to facilitate the improvement of endoscopic patient care through the acquisition of best endoscopic practice. Patients should not expect additional benefit from being treated during a LEE compared to a routine setting. There is limited available evidence on LEE safety but to date there is no indication that patients are at increased risk from participation. Pre-recorded cases with live facilitation can also be used to fulfill learning outcomes. Establishing an endoscopic curriculum with clear learning outcomes is important to structure attendees’ learning, assess course outcomes, and allow appropriate targeting of courses to learner experience. Increasingly, LEEs are streamed online and therefore the necessary measures should be taken to ensure that patients have given appropriate consent and that their anonymity has been safeguarded. ESGE recommends that an endoscopist who is not participating in the live demonstrations is named as patient advocate, and that patient safety should must be prioritized throughout. In all ESGE-organized LEEs the intended learning outcomes, procedural indications and descriptions, attendee feedback, and adverse events should be recorded and submitted in a post-event report to ESGE.
Minimally Invasive Direct Coronary Artery Bypass in High-Risk Patients with Multivessel Disease
Authors: Hoffmann Grischa , Friedrich Christine , Huenges Katharina , Petzina Rainer , Vogt Astrid-Mareike , Cremer Joachim , Grothusen Christina
Published: June 2021

Background High-risk patients with multivessel disease (MVD) including a complex stenosis of the left anterior descending coronary may not be ideal candidates for guideline compliant therapy by coronary artery bypass grafting (CABG) regarding invasiveness and perioperative complications. However, they may benefit from minimally invasive direct coronary artery bypass (MIDCAB) grafting and hybrid revascularization (HCR).

Methods A logistic European system for cardiac operative risk evaluation score (logES) >10% defined high risk. In high-risk patients with MVD undergoing MIDCAB or HCR, the incidence of major adverse cardiac and cerebrovascular events (MACCEs) after 30 days and during midterm follow-up was evaluated.

Results Out of 1,250 patients undergoing MIDCAB at our institution between 1998 and 2015, 78 patients (logES: 18.5%; age, 76.7 ± 8.6 years) met the inclusion criteria. During the first 30 days, mortality and rate of MACCE were 9.0%; early mortality was two-fold overestimated by logES. Complete revascularization as scheduled was finally achieved in 64 patients (82.1%). Median follow-up time reached 3.4 (1.2–6.5) years with a median survival time of 4.7 years. Survival after 1, 3, and 5 years was 77, 62, and 48%.

Conclusion In high-risk patients with MVD, MIDCAB is associated with acceptable early outcome which is better than predicted by logES. Taking the high-risk profile into consideration, midterm follow-up showed satisfying results, although scheduled HCR was not realized in a relevant proportion. In selected cases of MVD, MIDCAB presents an acceptable alternative for high-risk patients.
Dynamic evolution of arc plasma in a semi-enclosed arc-extinguishing chamber and its influencing factors
Authors: Sima Wenxia , Jia Wenbin , Yuan Tao , Yang Ming , Cheng Huang , Zuo Sijia
Published: June 2021

Multi-chamber arc-extinguishing has been widely researched and used to protect transmission and distribution lines from lightning. Its principle is to divide a long-gap arc into multiple short-gap arcs using multiple semi-enclosed arc-extinguishing chambers. To study the dynamic evolution of arc plasma in an arc-extinguishing chamber, we establish a three-dimensional simulation model of arc plasma in a semi-enclosed arc-extinguishing chamber by solving the Navier–Stokes and Maxwell equations. We analyze the dynamic evolution of an arc from the inside of the chamber to the outside. An impact current test platform is built and the arc motion is photographed by a high-speed camera, revealing the acceleration of the arc in the semi-enclosed chamber. Finally, the influence of chamber dimensions on key arc parameters is analyzed. In the simulation, the time when the arc completely moves out of the chamber and is extinguished is consistent with the experimental images, which verifies the accuracy of the simulation model. The arc temperature, chamber pressure, and airflow velocity first increase in an oscillating manner and then slowly decrease with time. The change of the opening diameter will lead to the obvious change of the arc temperature maximum. The opening diameter is the main chamber dimension that affects the arc temperature. The electrode spacings have the most obvious effect on the maximum pressure in the chamber. The minimum pressure in different chamber dimensions is lower than the atmospheric pressure. The influence of opening diameter, distance from central axis to closed side, and opening wall length on the maximum airflow velocity is the same, and the maximum airflow velocity decreases with the increase in these dimensions. The influence of electrode spacing on the maximum airflow velocity is opposite to them.
Macromolecular crowding effects on electrostatic binding affinity: Fundamental insights from theoretical, idealized models
Authors: Kim Rachel , Radhakrishnan Mala L.
Published: June 2021

The crowded cellular environment can affect biomolecular binding energetics, with specific effects depending on the properties of the binding partners and the local environment. Often, crowding effects on binding are studied on particular complexes, which provide system-specific insights but may not provide comprehensive trends or a generalized framework to better understand how crowding affects energetics involved in molecular recognition. Here, we use theoretical, idealized molecules whose physical properties can be systematically varied along with samplings of crowder placements to understand how electrostatic binding energetics are altered through crowding and how these effects depend on the charge distribution, shape, and size of the binding partners or crowders. We focus on electrostatic binding energetics using a continuum electrostatic framework to understand effects due to depletion of a polar, aqueous solvent in a crowded environment. We find that crowding effects can depend predictably on a system’s charge distribution, with coupling between the crowder size and the geometry of the partners’ binding interface in determining crowder effects. We also explore the effect of crowder charge on binding interactions as a function of the monopoles of the system components. Finally, we find that modeling crowding via a lowered solvent dielectric constant cannot account for certain electrostatic crowding effects due to the finite size, shape, or placement of system components. This study, which comprehensively examines solvent depletion effects due to crowding, complements work focusing on other crowding aspects to help build a holistic understanding of environmental impacts on molecular recognition.
The essential role of the plasma sheath in plasma–liquid interaction and its applications—A perspective
Authors: Vanraes Patrick , Bogaerts Annemie
Published: June 2021

Based on the current knowledge, a plasma–liquid interface looks and behaves very differently from its counterpart at a solid surface. Local processes characteristic to most liquids include a stronger evaporation, surface deformations, droplet ejection, possibly distinct mechanisms behind secondary electron emission, the formation of an electric double layer, and an ion drift-mediated liquid resistivity. All of them can strongly influence the interfacial charge distribution. Accordingly, the plasma sheath at a liquid surface is most likely unique in its own way, both with respect to its structure and behavior. However, insights into these properties are still rather scarce or uncertain, and more studies are required to further disclose them. In this Perspective, we argue why more research on the plasma sheath is not only recommended but also crucial to an accurate understanding of the plasma–liquid interaction. First, we analyze how the sheath regulates various elementary processes at the plasma–liquid interface, in terms of the electrical coupling, the bidirectional mass transport, and the chemistry between plasma and liquid phase. Next, these three regulatory functions of the sheath are illustrated for concrete applications. Regarding the electrical coupling, a great deal of attention is paid to the penetration of fields into biological systems due to their relevance for plasma medicine, plasma agriculture, and food processing. Furthermore, we illuminate the role of the sheath in nuclear fusion, nanomaterial synthesis, and chemical applications. As such, we hope to motivate the plasma community for more fundamental research on plasma sheaths at liquid surfaces.
Enhancement of photon detection in superconducting nanowire single photon detector exposed to oscillating magnetic field
Authors: Hakimi Ilan , Vardi Naor , Sharoni Amos , Rosenbluh Michael , Yeshurun Yosef
Published: June 2021

We measured the photon count rate (PCR) and dark count rate (DCR) of a superconducting nanowire single photon detector (SNSPD) exposed to either a DC magnetic field (up to 60 mT) or to a low-amplitude oscillating field (0.12–0.48 mT, up to 50 kHz). In both cases, the results show an increase in the PCR and the DCR as the DC field or the frequency of the AC field increase. However, the ratio DCR/(PCR + DCR) increases significantly with an increasing DC field, whereas this ratio is approximately constant as the frequency of the AC field increases up to frequencies in the kHz regime. The results suggest a more favorable effect of AC fields on the operation of the SNSPD.
The electron affinity of the uranium atom
Authors: Ciborowski Sandra M. , Liu Gaoxiang , Blankenhorn Moritz , Harris Rachel M. , Marshall Mary A. , Zhu Zhaoguo , Bowen Kit H. , Peterson Kirk A.
Published: June 2021

The results of a combined experimental and computational study of the uranium atom are presented with the aim of determining its electron affinity. Experimentally, the electron affinity of uranium was measured via negative ion photoelectron spectroscopy of the uranium atomic anion, U−. Computationally, the electron affinities of both thorium and uranium were calculated by conducting relativistic coupled-cluster and multi-reference configuration interaction calculations. The experimentally determined value of the electron affinity of the uranium atom was determined to be 0.309 ± 0.025 eV. The computationally predicted electron affinity of uranium based on composite coupled cluster calculations and full four-component spin–orbit coupling was found to be 0.232 eV. Predominately due to a better convergence of the coupled cluster sequence for Th and Th−, the final calculated electron affinity of Th, 0.565 eV, was in much better agreement with the accurate experimental value of 0.608 eV. In both cases, the ground state of the anion corresponds to electron attachment to the 6d orbital.
2D particle-in-cell simulations of the electron temperature anisotropy driven whistler instability in plasmas having kappa velocity distributions
Authors: Abdul R. F. , Matthews A. P. , Mace R. L.
Published: June 2021

This study presents the results of 2D particle-in-cell (PIC) simulations of the electron temperature anisotropy driven whistler instability for plasmas in which the electron species is modeled by a bi-kappa velocity distribution. These simulations utilize our previously developed method to generate the initial multi-dimensional kappa velocity distributions. The use of multi-dimensional kappa loadings in PIC simulations provides insights into the non-linear regime of wave evolution in plasmas having non-equilibrium velocity distributions. Three cases are considered, corresponding to κe=2,3, and ∞ (Maxwellian case). Owing to the use of a large value of electron anisotropy required for reasonable simulation run times, the Maxwellian electron run has the fastest growth rate, reaching saturation earliest. The κe=2 case exhibits the slowest growth rate. Spectral analysis of the fluctuating fields reveals considerable wave intensity at frequencies and wavenumbers that satisfy the linear whistler wave dispersion relation. In the runs with kappa distributions, the regions of most intense fluctuations comprise frequencies and wavenumbers that agree only qualitatively with linear whistler wave theory. The results suggest that after saturation, there is some degree of Landau damping of the oblique whistler modes, which returns energy to the electron species. The rate of damping of the oblique modes is highest in the Maxwellian case and lowest for κe=2. Evidence of significant superthermal acceleration of electrons in the direction parallel to the ambient magnetic field is also observed. Thus, the power-law index of the electron distribution is reduced by the anisotropic whistler turbulence produced.
Machine learning-aided design optimization of a mechanical micromixer
Authors: Granados-Ortiz F.-J. , Ortega-Casanova J.
Published: June 2021

In real-life mechanical engineering applications, it is often complex to achieve an optimal multi-objective design, because of the costs related to fabrication and test of different prototypes. For this reason, the use of computational tools is a recommended practice. In this work, the design of an efficient mixing mechanical device composed of a rectangular pillar confined in a microchannel is aided by machine learning techniques (addressed as machine learning-aided design optimization, MLADO, proposed in this work). A random forest classifier is trained to predict which geometric configuration may lead to vortex shedding. Later, a multi-objective optimization problem is investigated, which consists of minimizing the required pumping power and maximizing the mixing efficiency under some design constrains. If extra training data are desired for surrogates, the random forest classifier can be used to predict whether it is worthy or not to simulate the new configuration, avoiding to run irrelevant computational intensive cases and accelerating the data-driven process. The resulting optimal designs from using the NSGA-II genetic algorithm on the surrogates are simulated, and their performance is shown. The optimal geometric configurations, even for very unfavorable mixing conditions and a medium-low Reynolds number of 200, give a maximum mixing efficiency of around 50% at very low pumping power cost in a short channel, outperforming existing devices in the literature. The MLADO framework followed in this work can be easily extendable and automated for other similar design processes in mechanical engineering at any scale, by including shape parameterization strategies.
Identification of an ultrafast internal conversion pathway of pyrazine by time-resolved vacuum ultraviolet photoelectron spectrum simulations
Authors: Kanno Manabu , Mignolet Benoît , Remacle Françoise , Kono Hirohiko
Published: June 2021

The internal conversion from the optically bright S2 (1B2u, ππ*) state to the dark S1 (1B3u, nπ*) state in pyrazine is a standard benchmark for experimental and theoretical studies on ultrafast radiationless decay. Since 2008, a few theoretical groups have suggested significant contributions of other dark states S3 (1Au, nπ*) and S4 (1B2g, nπ*) to the decay of S2. We have previously reported the results of nuclear wave packet simulations [Kanno et al., Phys. Chem. Chem. Phys. 17, 2012 (2015)] and photoelectron spectrum calculations [Mignolet et al., Chem. Phys. 515, 704 (2018)] that support the conventional two-state picture. In this article, the two different approaches, i.e., wave packet simulation and photoelectron spectrum calculation, are combined: We computed the time-resolved vacuum ultraviolet photoelectron spectrum and photoelectron angular distribution for the ionization of the wave packet transferred from S2 to S1. The present results reproduce almost all the characteristic features of the corresponding experimental time-resolved spectrum [Horio et al., J. Chem. Phys. 145, 044306 (2016)], such as a rapid change from a three-band to two-band structure. This further supports the existence and character of the widely accepted pathway (S2 → S1) of ultrafast internal conversion in pyrazine.