bluuebunny/crossref_metadata_2025 huggingface dataset:
Velocity measurement in the extensive [OIII] emission region 1.2° south-east of M 31
Authors: Amram P. , Adami C. , Epinat B. , Chemin L.
Published: March 2023

Context. The discovery of a broad, ∼1.5° long filamentary [OIII] 5007 emission ∼1.2° south-east of the M 31 nucleus has recently been reported. More than 100 hours of exposures of a wide field (3.48° × 2.32°) have allowed this pioneering detection based on 30 Å narrow-band filters and several small refractors equipped with large cameras.

Aims. We report a first velocity measurement in this extensive [OIII] emission line region.

Methods. We used the low-resolution spectrograph MISTRAL (R ∼ 750), a facility of the Haute-Provence Observatory 193 cm telescope. The velocity measurement is based on the Hα, [NII], [SII] and [OIII] lines.

Results. The best solution to fit the spectrum indicates that the Hα and [OIII] emissions are at the same heliocentric line-of-sight velocity of −96±4 km s−1. This was measured within an area of ∼250 arcsec2 selected on a bright knot along the long filament of ∼1.5°, together with a [OIII]5007 surface brightness of 4.2±2.1×10−17 erg s−1 cm−2 arcsec−2. This agrees moderately well with the previous measurement. We also estimated the Hα/[NII] line ratio as ∼1.1.

Conclusions. The radial velocities at which the Hα and [OIII] lines were detected seem to show that these hydrogen and oxygen atoms belong to the same layer, but we cannot exclude that another weaker [OIII] line, belonging to another structure, that is, at another velocity, is below our detection threshold. Different scenarios have been considered to explain this filamentary structure. The extra-galactic origin was excluded in favour of Galactic origins. We tentatively assume that this filament is a piece of a supernova remnant located at a distance of ∼0.7 kpc from the Sun, of which we only see a small fraction of the shells with a radius of ∼35 pc. The progenitor may be along the line of sight of the galaxy M 31, but this observation might also just be part of a large-scale filamentary structure that should be investigated further.
Quality indicators of traditional Bulgarian artisanal sheep’s cheese
Authors: Stankov Stanko , Fidan Hafize , Dincheva Ivayla , Balabanova Tatyana , Ibrahim Salam A.
Published: March 2023

The aim of the present study is focused on the evaluation of the quality parameters of artisan sheep cheese produced by old Bulgarian technology. The study was carried out in three stages - at the end of the ripening process (45th day), during and at the end of storage (180th and 360th day). An increase of 9.0% in dry matter and a decrease in water content and titratable acidity values were observed over the entire period studied. There was a decrease in oleic fatty acid (C18:1n9c) from 28.16% at day 45 to 26.09% at day 360 of ripening. In the case of palmitic acid (C16:0) the values recorded were similar from 30.24% (45th day) to 30.74% (360th day). Changes in the composition of organic acids were observed, with lactic acid levels decreasing from 27.66% at day 45 to 8.62% at day 360. After microbiological analysis, it was found that the main microflora present in the samples were representatives of lactic acid microorganisms as compared to the non-starter microflora.
Effect of sucrose replacement on nutritional parameters and sensory characteristics of the lollipops with isomaltulose
Authors: Hadjikinova Raina , Petrova Ivanka
Published: March 2023

Lollipops are one of the most popular confectionary products among the consumers of all over the world. The main ingredient for their production is crystal sugar (sucrose). Its partial or complete replacement with suitable alternatives and sweeteners leads to change in sensory profile of lollipops and the overall perception by consumers. The use of isomaltulose may be consider as a revolution in confectionary industry due to its characteristics as a functional, digestible, non-cariogenic and just as important as a low glycaemic disaccharide. The aim of the present study was to evaluate the effect of isomaltulose as a sugar replacement in lollipops on main nutritional parameters and sensory characteristics as appearance (color and opacity), taste, aroma also the texture attribute perceived in a mouth. Results shown that isomaltulose can affect significantly the sensory and texture profile of the lollipops comparing the control products with sucrose. The data shows that samples have the same energy values of 388 kcal/g but sample obtained with isomaltulose has about 12% lower glycaemic indicator.
Influence of grape processing technology on the characteristics of the obtained distillates
Authors: Mitev Panko , Ginev Miroslav , Galabova Mariana , Melnyk Iryna
Published: March 2023

In the production of wine distillates, the factors influencing their composition, respectively their quality, can be divided into the following directions: composition of grapes (as raw material), the technology for its processing and alcoholic fermentation to obtain wine material, as well as the method of distillation of the wine material to derive a distillate. Each of these factors is important for the production of quality wine distillate and significantly affects the concentration of chemical substances that determine its aromatic and flavour profile. The present study was carried out with Muscat Ottonel grapes, a raw material typical for the production of Muscat brandies, through double batch distillation. The grapes are processed and vinified according to three different technological schemes. It is established their influence on both the chemical composition of the wine materials and the received distillate fractions, typical for batch distillation.
Microbiome status of unregulated raw tobacco blends for hand-rolling cigarettes (RYO tobaccos)
Authors: Hristeva Tsveta , Nikolov Nikolay , Nikolova Violeta , Peeva Silvia
Published: March 2023

The research was conducted on 18 samples of RYO tobacco. The density (CFU/g a.d.s.) of three heterotrophic groups of microorganisms and some physical-chemical indicators were determined. The analyses were performed according to classic methods. Quantitative and qualitative changes at the microbiome as a result of disruption of homeostasis in microbial communities and development of secondary succession in the direction of intensive mineralization processes were found. Statistically significant correlation dependences with the physical-chemical parameters were registered. In addition to a potential risk in term of sanitary-hygiene and health aspects, the changes also have a negative impact on the consumer qualities of tobacco blends.
Isolation and selection of sauerkraut lactic acid bacteria producing exopolysaccharides
Authors: Georgieva Aneliya , Petkova Mariana , Todorova Emanoila , Gotcheva Velitchka , Angelov Angel
Published: March 2023

Fermented plant-based foods, including sauerkraut, offer high nutritional and functional value. Their microflora is dominated by lactic acid bacteria which are a source of different substances with health- promoting benefits and diverse applications in the food industry. Production of exopolysaccharides (EPSs) by lactic acid bacteria attracts particular interest in the food industry due to their rheological properties. In the present study, we isolated 20 strains of lactic acid bacteria from traditional Bulgarian sauerkraut. The isolates were identified by 16S rDNA sequencing and were attributed to Lactiplantibacillus plantarum (75%) and Pediococcus pentosaceus (25%). All strains were screened for their ability to synthesize exopolysaccharides, and 6 of them proved positive. Since culture media composition and especially the carbon source is a critical factor influencing the yield of bacterial EPSs, the impact of various carbon sources on the EPSs synthesis by the selected producers was explored. The best results were obtained by using glucose and sucrose as sole carbon sources.
PCR analysis for meat products authenticity - detection of horse meat
Authors: Stefanova Petya , Gotcheva Velitchka , Angelov Angel
Published: March 2023

Food adulteration regarding species origin of meats is a common problem in the meat products sector. With regard to horse meat, its undeclared use in food products is not only a fraud, but could present a health risk since is often associated with the presence of the veterinary drug phenylbutazone in meat products. Therefore, it is important to use reliable methods for authentication of meat products regarding their species composition, which are applicable to complex food matrices. Polymerase chain reaction (PCR) with species-specific primers remains the most widely used analytical approach to detect species-related food adulteration due to its high sensitivity and specificity. The aim of the present study was to establish the authenticity of 20 different meat products on the Bulgarian market without declared horse meat content by using a species-specific PCR method. The specificity test of the PCR method used showed no amplification of DNA from beef and pork. A detection limit of 0.01% horse DNA in three-component meat mixtures was established for the PCR method. The PCR method enabled detection of undeclared presence of horse meat in 25% of the analyzed meat products, which demonstrates the need for strict control regarding authenticity in the meat food chain.
Investigation of selected independent variables on extrusion of rice semolina with and without propeller
Authors: Chalamov Yanush , Simitchiev Apostol , Nenov Ventzislav , Vassilev Kiril
Published: March 2023

The influence of screws with and without propeller, as well as the independent variables of material moisture content, working screw speed, feeding screw speed and die temperature on the changes of some physical and mechanical properties during singles-screw extrusion of rice semolina was studied. The response surface methodology was used with an orthogonal central composite design. Optimum modes of operation which lead to the maximization of the mass flow rate and the sectional expansion index and the minimization of the specific mechanical energy were established. The obtained results show that the use of a propeller in single-screw extrusion leads to an increase in extruder mass flow rate, a decrease in the specific mechanical energy and an increase in the sectional expansion index.
Metal ions removal from wastewaters using Moringa oleifera seeds
Authors: Stanikina Nikoleta
Published: March 2023

Heavy metal contamination and its consequences for human health and the environment have gained interest in developing economical, easy-to-use and environmentally friendly methods in wastewater treatment. One such aspect is the utilization of natural materials collected from plants in coagulation- flocculation process. This study outlines the potentialities of metal ions removal from wastewater through the use of Moringa oleifera seeds. Water samples were taken from the entrance and exit of a sewage treatment plant and the quality of water was examined before and after the treatment using aqueous extracts from powdered seeds with different dosages between 1 and 6 g/1. The determination of Chloride and Fluoride was performed by an automatic Mettler Toledo titrator with an electrode 141 SC and Fluoride selective electrode, ICP-OES determined the concentration of 12 heavy metals, all calibrated before use. The removal efficiency of the extracted bio flocculants was influenced by the type and initial concentration of water pollutants as well the dosage used. The highest percentage of removal was 98% for Fe, 95% for Cu and 72% for Zn, whereas this effect was less notable for residual Cl ions even at high dosage and have no influence of fluoride concentration.
A software tool for data mining of physicochemical properties of peptides
Authors: Terziyski Zhelyazko , Terziyska Margarita , Hadzhikoleva Stanka , Desseva Ivelina
Published: March 2023

Biologically active peptides (BAP) are increasingly in the focus of scientific research due to their widespread use in medicine, food and pharmaceutical industries. Researching and studying the properties of peptides is a laborious and expensive process. In recent years, in silico methods, including data mining or artificial intelligence, have been applied more and more to reveal biological, physicochemical and sensory properties of peptides. This significantly shortens the process of peptide sequences analysis. This article presents a software tool that uses a data mining approach to discover a number of physicochemical properties of a specific peptide. Working with it is extremely simple - it is only necessary to input the amino acid sequence of the peptide of interest. The software tool is designed to generate data in order to increase the classification and prediction accuracy, as well as to leverage the engineering of new amino acid sequences. This way, the proposed software greatly facilitates the work or scientific researchers. The software application is publicly available at www.pep-lab.info/dmpep.
Nanoporous structures with Fe0/FeII/FeIII co-existed as catalysts for phenol degradation
Authors: Ni Bingying , Zhao Zhankui , Shi Jinfang
Published: March 2023

Fe-based amorphous alloy was widely concerned in the field of wastewater treatment because of its nanoporous structure, which has higher reactivity activity. However, as it is easy to get oxidative poisoning, its long-term reactivity activity is restricted. A uniform nanoporous layer has been synthesized by mechanical attrition and dealloying on the surface of Fe76Si9B10P5 amorphous alloy powders in this work. In the test of catalytic performance, due to nanoporous structure, Fe0/FeⅡ/FeⅢ are involved in the Fenton process at the same time. The Fenton reaction was further catalyzed to generate more active group  · OH; therefore, the degradation rate reaches 99.8% within 60 min. This coexistence of Fe0/FeII/FeIII persisted after five cycles of the catalytic reaction, indicating the excellent catalytic stability of the catalyst. Using this tunable pretreatment method for surface activation, novel applications for metallic glasses can be developed.
Die Äskulapnatter – Symbol der
Heilkundigen
Authors: Brendieck-Worm Cäcilia
Published: March 2023

Die Äskulapnatter, Symbol der Heilung, ist in ihrem ursprünglich
weit ausgedehnten Verbreitungsraum selten geworden. Die ungiftige Schlange
bevorzugt feuchte, warme Habitate mit ausreichend
Unterschlupfmöglichkeiten in verfallenem Gemäuer oder lichtem
Buschwerk. Um die Bestände der stark gefährdeten Art zu
erhalten, muss man für geeignete Brut-, Sonnen- und
Überwinterungsplätze sorgen und den Verlusten durch
Straßenverkehr und Mäharbeiten vorbeugen.
SARS-CoV-2 in Pregnancy, Birth and Puerperium. Guideline of the DGGG and DGPM (S2k-Level, AWMF Registry Number 015/092, March 2022)
Authors: Pecks Ulrich , Agel Lena , Doubek Klaus J. , Hagenbeck Carsten , Jennewein Lukas , von Kaisenberg Constantin , Kranke Peter , Leitner Sabine , Mand Nadine , Rüdiger Mario , Zöllkau Janine , Mingers Nina , Sitter Magdalena , Louwen Frank
Published: March 2023

Objective This S2k guideline of the German Society for Gynecology and Obstetrics (DGGG) and the German Society of Perinatal Medicine (DGPM) contains consensus-based recommendations for the care and treatment of pregnant women, parturient women, women who have recently given birth, and breastfeeding women with SARS-CoV-2 infection and their newborn infants. The aim of the guideline is to provide recommendations for action in the time of the COVID-19 pandemic for professionals caring for the above-listed groups of people.

Methods The PICO format was used to develop specific questions. A systematic targeted search of the literature was carried out using PubMed, and previously formulated statements and recommendations issued by the DGGG and the DGPM were used to summarize the evidence. This guideline also drew on research data from the CRONOS registry. As the data basis was insufficient for a purely evidence-based guideline, the guideline was compiled using an S2k-level consensus-based process. After summarizing and presenting the available data, the guideline authors drafted recommendations in response to the formulated PICO questions, which were then discussed and voted on.

Recommendations Recommendations on hygiene measures, prevention measures and care during pregnancy, delivery, the puerperium and while breastfeeding were prepared. They also included aspects relating to the monitoring of mother and child during and after infection with COVID-19, indications for thrombosis prophylaxis, caring for women with COVID-19 while they are giving birth, the presence of birth companions, postnatal care, and testing and monitoring the neonate during rooming-in or on the pediatric ward.
Palladium(II)-Catalyzed Intramolecular Tandem Cyclization Reaction for the Assembly of Unsymmetrical 2,6-Disubstituted Pyrazines
Authors: Chen Wenteng , Zhang Guolin , Chen Yitong , Zhu Qi , Wang Haiyang , Yu Yongping
Published: March 2023

An efficient synthesis of unsymmetrical 2,6-disubstituted pyrazines was developed via a palladium(II)-catalyzed cascade reaction from aminoacetonitriles and arylboronic acids. This transformation involves a C(sp)–C(sp2) coupling followed by an intramolecular C–N bond formation in good to excellent yields.
Diiodine–Triethylsilane System: Formation of N-Alkylsulfonamides from Aldehydes or Ketones and Sulfonamides
Authors: Jiang Jin , Feng Siyan , Chang Jinming
Published: March 2023

Reductive amination has not been commonly used in the preparation of N-alkylsulfonamides because of the low nucleophilicity of sulfonamides. In this work, a protocol for the synthesis of N-alkylsulfonamides from aldehydes or ketones and sulfonamides was developed. Molecular iodine, triethylsilane, and ethyl acetate were used as the initiator, reductant, and solvent, respectively. The key role of triethyl(iodo)silane in the reaction was confirmed through control experiments.
Markov properties of partially open quantum random walks
Authors: Kang Yuan Bao
Published: March 2023

In this paper, we first construct (nonhomogeneous) quantum Markov chains (QMCs, for short) associated with partially open quantum random walks (POQRWs, for short). We then focus on the study of the analogs of irreducibility, period, and ergodic behavior of POQRWs by QMCs. Moreover, we get the characterization of invariant states of POQRWs via QMCs.
Determining local modulus and strength of heterogeneous films by force–deflection mapping of microcantilevers
Authors: Larsen Kyle , Lehnardt Stefan , Anderson Bryce , Rowley Joseph , Vanfleet Richard , Davis Robert
Published: March 2023

Estimating the elastic modulus and strength of heterogeneous films requires local measurement techniques. For local mechanical film testing, microcantilevers were cut into suspended many-layer graphene using a focused ion beam. An optical transmittance technique was used to map thickness near the cantilevers, and multipoint force–deflection mapping with an atomic force microscope was used to record the compliance of the cantilevers. These data were used to estimate the elastic modulus of the film by fitting the compliance at multiple locations along the cantilever to a fixed-free Euler–Bernoulli beam model. This method resulted in a lower uncertainty than is possible from analyzing only a single force–deflection. The breaking strength of the film was also found by deflecting cantilevers until fracture. The average modulus and strength of the many-layer graphene films are 300 and 12 GPa, respectively. The multipoint force–deflection method is well suited to analyze films that are heterogeneous in thickness or wrinkled.
Study of stationary rigidly rotating anisotropic cylindrical fluids with new exact interior solutions of GR. II. More about axial pressure
Authors: Célérier M.-N.
Published: March 2023

This paper is the second in a series devoted to the study of spacetimes sourced by a stationary cylinder of fluid rigidly rotating around its symmetry axis and exhibiting an anisotropic pressure by using new exact interior solutions of general relativity. The configurations have been specialized to three different cases where the pressure is, in turn, directed alongside each principal stress. The two first articles in the series display the analysis of the axial pressure case. Indeed, the first axial class published in Paper I is merely a special case. It is recalled here and its properties are revised and supplemented. Moreover, a fully general method aiming at constructing different classes of such solutions is displayed. This method described in Paper II represents a key result of this work. It is exemplified and applied to two new classes of solutions depending on a single constant parameter. One of them, denoted Class A, is shown to verify every condition needing to be satisfied by a fully achieved set of exact solutions: axisymmetry and, when appropriate, regularity conditions; matching to an exterior vacuum; proper metric signature; and weak and strong energy conditions. Other properties and general rules are exhibited, some shedding light on rather longstanding issues. Astrophysical and physical applications are suggested.
Microstructures and properties of as-cast AlCrFeMnV, AlCrFeTiV, and AlCrMnTiV multi-principal element alloys
Authors: Knipling K. , Narayana P. , Nguyen L. , Beaudry D.
Published: March 2023

This study reports on the as-cast microstructures of AlCrFeMnV, AlCrFeTiV, and AlCrMnTiV equimolar multi-principal element alloys. Thermodynamic modeling predicts that these alloys solidify as BCC solid solutions, with additional phases forming at lower temperatures. We present the measured densities, the elastic modulus values measured by nanoindentation, and the Vickers microhardness of the alloys. These properties are correlated to the underlying microstructures, as measured by x-ray diffraction, scanning electron microscopy, and atom-probe tomography. The densities of the alloys range from 5.53 to 6.42 ×103 kgm−3. The elastic modulus of AlCrFeMnV, AlCrFeTiV, and AlCrMnTiV are 211, 194, and 175 GPa, respectively, and their Vickers microhardness values are 3.9, 6.1, and 5.7 GPa, respectively. After arc-melting, AlCrFeMnV and AlCrFeTiV are BCC solid solutions while AlCrMnTiV has two phases: a BCC phase and a minor hexagonal C14 Laves phase that is enriched in V and Cr.
Quantifying heterogeneity to drug response in cancer–stroma kinetics
Authors: Alemanno Francesco , Cavo Marta , Delle Cave Donatella , Fachechi Alberto , Rizzo Riccardo , D’Amone Eliana , Gigli Giuseppe , Lonardo Enza , Barra Adriano , del Mercato Loretta L.
Published: March 2023

A crucial challenge in medicine is choosing which drug (or combination) will be the most advantageous for a particular patient. Usually, drug response rates differ substantially, and the reasons for this response unpredictability remain ambiguous. Consequently, it is central to classify features that contribute to the observed drug response variability. Pancreatic cancer is one of the deadliest cancers with limited therapeutic achievements due to the massive presence of stroma that generates an environment that enables tumor growth, metastasis, and drug resistance. To understand the cancer–stroma cross talk within the tumor microenvironment and to develop personalized adjuvant therapies, there is a necessity for effective approaches that offer measurable data to monitor the effect of drugs at the single-cell level. Here, we develop a computational approach, based on cell imaging, that quantifies the cellular cross talk between pancreatic tumor cells (L3.6pl or AsPC1) and pancreatic stellate cells (PSCs), coordinating their kinetics in presence of the chemotherapeutic agent gemcitabine. We report significant heterogeneity in the organization of cellular interactions in response to the drug. For L3.6pl cells, gemcitabine sensibly decreases stroma–stroma interactions but increases stroma–cancer interactions, overall enhancing motility and crowding. In the AsPC1 case, gemcitabine promotes the interactions among tumor cells, but it does not affect stroma–cancer interplay, possibly suggesting a milder effect of the drug on cell dynamics.
Transcription shapes 3D chromatin organization by interacting with loop extrusion
Authors: Banigan Edward J. , Tang Wen , van den Berg Aafke A. , Stocsits Roman R. , Wutz Gordana , Brandão Hugo B. , Busslinger Georg A. , Peters Jan-Michael , Mirny Leonid A.
Published: March 2023

Cohesin folds mammalian interphase chromosomes by extruding the chromatin fiber into numerous loops. “Loop extrusion” can be impeded by chromatin-bound factors, such as CTCF, which generates characteristic and functional chromatin organization patterns. It has been proposed that transcription relocalizes or interferes with cohesin and that active promoters are cohesin loading sites. However, the effects of transcription on cohesin have not been reconciled with observations of active extrusion by cohesin. To determine how transcription modulates extrusion, we studied mouse cells in which we could alter cohesin abundance, dynamics, and localization by genetic “knockouts” of the cohesin regulators CTCF and Wapl. Through Hi-C experiments, we discovered intricate, cohesin-dependent contact patterns near active genes. Chromatin organization around active genes exhibited hallmarks of interactions between transcribing RNA polymerases (RNAPs) and extruding cohesins. These observations could be reproduced by polymer simulations in which RNAPs were moving barriers to extrusion that obstructed, slowed, and pushed cohesins. The simulations predicted that preferential loading of cohesin at promoters is inconsistent with our experimental data. Additional ChIP-seq experiments showed that the putative cohesin loader Nipbl is not predominantly enriched at promoters. Therefore, we propose that cohesin is not preferentially loaded at promoters and that the barrier function of RNAP accounts for cohesin accumulation at active promoters. Altogether, we find that RNAP is an extrusion barrier that is not stationary, but rather, translocates and relocalizes cohesin. Loop extrusion and transcription might interact to dynamically generate and maintain gene interactions with regulatory elements and shape functional genomic organization.
Proprioceptive feedback amplification restores effective locomotion in a neuromechanical model of lampreys with spinal injuries
Authors: Hamlet Christina , Fauci Lisa , Morgan Jennifer R. , Tytell Eric D.
Published: March 2023

Spinal injuries in many vertebrates can result in partial or complete loss of locomotor ability. While mammals often experience permanent loss, some nonmammals, such as lampreys, can regain swimming function, though the exact mechanism is not well understood. One hypothesis is that amplified proprioceptive (body-sensing) feedback can allow an injured lamprey to regain functional swimming even if the descending signal is lost. This study employs a multiscale, integrative, computational model of an anguilliform swimmer fully coupled to a viscous, incompressible fluid and examines the effects of amplified feedback on swimming behavior. This represents a model that analyzes spinal injury recovery by combining a closed-loop neuromechanical model with sensory feedback coupled to a full Navier–Stokes model. Our results show that in some cases, feedback amplification below a spinal lesion is sufficient to partially or entirely restore effective swimming behavior.
Using conditional independence tests to elucidate causal links in cell cycle regulation in
Escherichia coli
Authors: Kar Prathitha , Tiruvadi-Krishnan Sriram , Männik Jaana , Männik Jaan , Amir Ariel
Published: March 2023

How cells regulate their cell cycles is a central question for cell biology. Models of cell size homeostasis have been proposed for bacteria, archaea, yeast, plant, and mammalian cells. New experiments bring forth high volumes of data suitable for testing existing models of cell size regulation and proposing new mechanisms. In this paper, we use conditional independence tests in conjunction with data of cell size at key cell cycle events (birth, initiation of DNA replication, and constriction) in the model bacterium
Escherichia coli
to select between the competing cell cycle models. We find that in all growth conditions that we study, the division event is controlled by the onset of constriction at midcell. In slow growth, we corroborate a model where replication-related processes control the onset of constriction at midcell. In faster growth, we find that the onset of constriction is affected by additional cues beyond DNA replication. Finally, we also find evidence for the presence of additional cues triggering initiations of DNA replication apart from the conventional notion where the mother cells solely determine the initiation event in the daughter cells via an adder per origin model. The use of conditional independence tests is a different approach in the context of understanding cell cycle regulation and it can be used in future studies to further explore the causal links between cell events.
MYC-driven synthesis of Siglec ligands is a glycoimmune checkpoint
Authors: Smith Benjamin A. H. , Deutzmann Anja , Correa Kristina M. , Delaveris Corleone S. , Dhanasekaran Renumathy , Dove Christopher G. , Sullivan Delaney K. , Wisnovsky Simon , Stark Jessica C. , Pluvinage John V. , Swaminathan Srividya , Riley Nicholas M. , Rajan Anand , Majeti Ravindra , Felsher Dean W. , Bertozzi Carolyn R.
Published: March 2023

The Siglecs (sialic acid-binding immunoglobulin-like lectins) are glycoimmune checkpoint receptors that suppress immune cell activation upon engagement of cognate sialoglycan ligands. The cellular drivers underlying Siglec ligand production on cancer cells are poorly understood. We find the
MYC
oncogene causally regulates Siglec ligand production to enable tumor immune evasion. A combination of glycomics and RNA-sequencing of mouse tumors revealed the
MYC
oncogene controls expression of the sialyltransferase
St6galnac4
and induces a glycan known as disialyl-T. Using in vivo models and primary human leukemias, we find that disialyl-T functions as a “don’t eat me” signal by engaging macrophage Siglec-E in mice or the human ortholog Siglec-7, thereby preventing cancer cell clearance. Combined high expression of
MYC
and
ST6GALNAC4
identifies patients with high-risk cancers and reduced tumor myeloid infiltration. MYC therefore regulates glycosylation to enable tumor immune evasion. We conclude that disialyl-T is a glycoimmune checkpoint ligand. Thus, disialyl-T is a candidate for antibody-based checkpoint blockade, and the disialyl-T synthase ST6GALNAC4 is a potential enzyme target for small molecule-mediated immune therapy.
Diamagnetic response and phase stiffness for interacting isolated narrow bands
Authors: Mao Dan , Chowdhury Debanjan
Published: March 2023

Superconductivity is a macroscopic manifestation of a quantum phenomenon where pairs of electrons delocalize and develop phase coherence over a long distance. A long-standing quest has been to address the underlying microscopic mechanisms that fundamentally limit the superconducting transition temperature,
T

c

. A platform which serves as an ideal playground for realizing “high”-temperature superconductors are materials where the electrons’ kinetic energy is quenched and interactions provide the only energy scale in the problem. However, when the noninteracting bandwidth for a set of isolated bands is small compared to the interactions, the problem is inherently nonperturbative. In two spatial dimensions,
T

c

is controlled by superconducting phase stiffness. Here, we present a theoretical framework for computing the electromagnetic response for generic model Hamiltonians, which controls the maximum possible superconducting phase stiffness and thereby
T

c

, without resorting to any mean-field approximation. Our explicit computations demonstrate that the contribution to the phase stiffness arises from i) “integrating out” the remote bands that couple to the microscopic current operator and ii) the density–density interactions projected on to the isolated narrow bands. Our framework can be used to obtain an upper bound on the phase stiffness and relatedly
T

c

for a range of physically inspired models involving both topological and nontopological narrow bands with density–density interactions. We discuss a number of salient aspects of this formalism by applying it to a specific model of interacting flat bands and compare the upper bound against the known
T

c

from independent numerically exact computations.
Convergence of Ras- and Rac-regulated formin pathways is pivotal for phagosome formation and particle uptake in
Dictyostelium
Authors: Körber Sarah , Junemann Alexander , Litschko Christof , Winterhoff Moritz , Faix Jan
Published: March 2023

Macroendocytosis comprising phagocytosis and macropinocytosis is an actin-driven process regulated by small GTPases that depend on the dynamic reorganization of the membrane that protrudes and internalizes extracellular material by cup-shaped structures. To effectively capture, enwrap, and internalize their targets, these cups are arranged into a peripheral ring or ruffle of protruding actin sheets emerging from an actin-rich, nonprotrusive zone at its base. Despite extensive knowledge of the mechanism driving actin assembly of the branched network at the protrusive cup edge, which is initiated by the actin-related protein (Arp) 2/3 complex downstream of Rac signaling, our understanding of actin assembly in the base is still incomplete. In the
Dictyostelium
model system, the Ras-regulated formin ForG was previously shown to specifically contribute to actin assembly at the cup base. Loss of ForG is associated with a strongly impaired macroendocytosis and a 50% reduction in F-actin content at the base of phagocytic cups, in turn indicating the presence of additional factors that specifically contribute to actin formation at the base. Here, we show that ForG synergizes with the Rac-regulated formin ForB to form the bulk of linear filaments at the cup base. Consistently, combined loss of both formins virtually abolishes cup formation and leads to severe defects of macroendocytosis, emphasizing the relevance of converging Ras- and Rac-regulated formin pathways in assembly of linear filaments in the cup base, which apparently provide mechanical support to the entire structure. Remarkably, we finally show that active ForB, unlike ForG, additionally drives phagosome rocketing to aid particle internalization.
When, how, and why the path of an air bubble rising in pure water becomes unstable
Authors: Bonnefis Paul , Fabre David , Magnaudet Jacques
Published: March 2023

Recently, [Herrada, M. A. and Eggers, J. G., Proc. Natl. Acad. Sci. U.S.A. 120, e2216830120 (2023)] reported predictions for the onset of the path instability of an air bubble rising in water and put forward a physical scenario to explain this intriguing phenomenon. In this Brief Report, we review a series of previously established results, some of which were overlooked or misinterpreted by the authors. We show that this set of findings provides an accurate prediction and a consistent explanation of the phenomenon that invalidates the suggested scenario. The instability mechanism actually at play results from the hydrodynamic fluid-body coupling made possible by the unconstrained motion of the bubble which behaves essentially, in the relevant size range, as a rigid, nearly spheroidal body on the surface of which water slips freely.
PP6 regulation of Aurora A–TPX2 limits NDC80 phosphorylation and mitotic spindle size
Authors: Sobajima Tomoaki , Kowalczyk Katarzyna M. , Skylakakis Stefanos , Hayward Daniel , Fulcher Luke J. , Neary Colette , Batley Caleb , Kurlekar Samvid , Roberts Emile , Gruneberg Ulrike , Barr Francis A.
Published: March 2023

Amplification of the mitotic kinase Aurora A or loss of its regulator protein phosphatase 6 (PP6) have emerged as drivers of genome instability. Cells lacking PPP6C, the catalytic subunit of PP6, have amplified Aurora A activity, and as we show here, enlarged mitotic spindles which fail to hold chromosomes tightly together in anaphase, causing defective nuclear structure. Using functional genomics to shed light on the processes underpinning these changes, we discover synthetic lethality between PPP6C and the kinetochore protein NDC80. We find that NDC80 is phosphorylated on multiple N-terminal sites during spindle formation by Aurora A–TPX2, exclusively at checkpoint-silenced, microtubule-attached kinetochores. NDC80 phosphorylation persists until spindle disassembly in telophase, is increased in PPP6C knockout cells, and is Aurora B-independent. An Aurora-phosphorylation-deficient NDC80-9A mutant reduces spindle size and suppresses defective nuclear structure in PPP6C knockout cells. In regulating NDC80 phosphorylation by Aurora A–TPX2, PP6 plays an important role in mitotic spindle formation and size control and thus the fidelity of cell division.
Enhancing the performance of coupled quantum Otto thermal machines without entanglement and quantum correlations
Authors: El Makouri Abdelkader , Slaoui Abdallah , Daoud Mohammed
Published: March 2023

We start with a revision study of two coupled spin-

1

/

2

under the influence of Kaplan–Shekhtman–Entin-Wohlman–Aharony interaction and a magnetic field. We first show the role of idle levels, i.e. levels that do not couple to the external magnetic field, when the system is working as a heat engine as well as when it is a refrigerator. Then we extend the results reported in Altintas and Müstecaplıoğlu (2015 Phys. Rev. E 92 022142) by showing that it is not necessary to change both the magnetic field as well as the coupling parameters to break the extensive property of the work extracted globally from two coupled spin-

1

/

2

as has been demonstrated there. Then we study the role of increasing the number of coupled spins on efficiency, extractable work, and coefficient of performance (COP). First, we consider two- and three-coupled spin-

1

/

2

Heisenberg

X
X
X

-chain. We prove that the latter can outperform the former in terms of efficiency, extractable work, and COP. Then we consider the Ising model, where the number of interacting spins ranges from two to six. We show that only when the number of interacting spins is odd the system can work as a heat engine in the strong coupling regime. The enhancements in efficiency and COP are explored in detail. Finally, this model confirms the idea that entanglement and quantum correlations are not the reasons behind the enhancements observed in efficiency, extractable work, and COP, but only due to the structure of the energy levels of the Hamiltonian of the working substance. In addition to this, the extensive property of global work as well, is not affected by entanglement and quantum correlations.
Seeded spin-mixing interferometry with long-time evolution in microwave-dressed sodium spinor Bose-Einstein condensates
Authors: Zhong Shan , Ooi Hio Giap , Prajapati Sankalp , Zhang Qimin , Schwettmann Arne
Published: March 2023

We experimentally demonstrate a new type of spin-mixing interferometry in sodium Bose–Einstein condensates (BECs) based on seeded initial states. Seeding is useful because it speeds up the generation of entangled pairs, allowing many collisions to take place quickly, creating large populations in the arms of the interferometer. The entangled probe states of our interferometer are generated via spin-exchange collisions in F = 1 spinor BECs, where pairs of atoms with the magnetic quantum number

m
F

=
0

collide and change into pairs with

m
F

=
±
1

. Our results show that our seeded spin-mixing interferometer beats the standard quantum limit (SQL) with a metrological gain of 3.69 dB with spin-mixing time t = 10 ms in the case of single-sided seeding, and 3.33 dB with spin-mixing time t = 8 ms in the case of double sided seeding. The mechanism for beating the SQL is two-mode spin squeezing generated via spin-exchange collisions. Our results on spin-mixing interferometry with seeded states are useful for future quantum technologies such as quantum-enhanced microwave sensors, and quantum parametric amplifiers based on spin-mixing.
All-metal cavity antenna with light weight, high efficiency and circular polarization for satellite platform applications
Authors: Luo Yanbin , Zeng Qingsheng , Xu Guanghui , Chen Shitao , Denidni Tayeb A , Gao Steven , Wang Wei
Published: March 2023

In this paper, a lightweight high-efficiency circularly polarized (CP) all-metal antenna design method is presented for satellite industry applications. The proposed antenna is composed of a rectangular waveguide feeder, a high-order mode cavity and a metasurface circular polarizer (MCP). The cavity high-order mode TE440 is directly excited by four coupling slots in the waveguide. The MCP is placed on the cavity to generate the CP radiation. Due to the introduction of high-order mode technology and MCP, all metal walls inside the antenna can be removed, which are necessary in conventional waveguide structures, and weight is thereby significantly reduced. To reflect the weight advantage, a conventional metal wall-loaded waveguide antenna of the same size is designed. The measured results show that the proposed antenna has wider impedance and axial ratio bandwidths, and higher radiation efficiency. In particular, the proposed antenna is 40% lighter than the comparative one, indicating that it is more applicable to satellite platforms with limited loading capacities.
Optical properties of ZnSe using linear response theory
Authors: Joshi Nikhil , Maurya Vijay , Joshi K B
Published: March 2023

The electronic structure and optical response of ZnSe are studied in this work. The studies are carried out using first-principles full-potential linearized augmented plane wave method. After settling the crystal structure, the electronic band structure of the ground state of ZnSe is calculated. Linear response theory is applied to study optical response considering bootstrap (BS) and the long range contribution (LRC) kernels for the first time. We also use the random phase and adiabatic local density approximations for comparison. A procedure based on empirical pseudopotential method is developed to find material dependent parameter α required in the LRC kernel. The results are assessed by calculating the real and imaginary parts of linear dielectric function, refractive index, reflectivity, and the absorption coefficient. Results are compared with other calculations and available experimental data. The results of LRC kernel finding α from the proposed scheme are encouraging and at par with the BS kernel.
Case study of developing an affordable undergraduate observatory
Authors: Scowcroft Victoria , Davies Steve R , Mathlin Gary , Sloan Peter A
Published: March 2023

Astronomy is one of the few sciences where the data (star-light) can be seen by all. Yet, there is a disconnect between a typical undergraduate lecture and, for example, where a planet may be in the sky and how to observe it. With the advent of moderate cost, high-quality ‘back-garden’ astronomy, and standard computers powerful enough to produce original research, we show it is possible to build a small observatory capable of actual astrophysical research for a modest budget

≈

£

30
000

. We detail the iterative process of planning, funding, results and student-projects, that we followed over 4 years from a Raspberry Pi camera and home-owned telescope, to a permanent roll-top observatory with two fully automated telescope systems capable of undergraduate use and astronomical science. We report on projects ranging from early-years projects based on observational planning, data analysis and some restricted actual observations, to more open-ended final-year projects to observe, e.g. planetary transits, variable stars or high-resolution planetary imaging. We hope this work may act as a blue-print or encourage and aid other small to medium sized higher-education institutions and astrophysics groups to also develop their own undergraduate observatory.
Automated treatment planning framework for brachytherapy of cervical cancer using 3D dose predictions
Authors: Kallis Karoline , Moore Lance C , Cortes Katherina G , Brown Derek , Mayadev Jyoti , Moore Kevin L , Meyers Sandra M
Published: March 2023

Objective. To lay the foundation for automated knowledge-based brachytherapy treatment planning using 3D dose estimations, we describe an optimization framework to convert brachytherapy dose distributions directly into dwell times (DTs). Approach. A dose rate kernel

d
̇

(
r
,
θ
,
φ
)

was produced by exporting 3D dose for one dwell position from the treatment planning system and normalizing by DT. By translating and rotating this kernel to each dwell position, scaling by DT and summing over all dwell positions, dose was computed (D
calc). We used a Python-coded COBYLA optimizer to iteratively determine the DTs that minimize the mean squared error between D
calc and reference dose D
ref, computed using voxels with D
ref 80%–120% of prescription. As validation of the optimization, we showed that the optimizer replicates clinical plans when D
ref = clinical dose in 40 patients treated with tandem-and-ovoid (T&O) or tandem-and-ring (T&R) and 0–3 needles. Then we demonstrated automated planning in 10 T&O using D
ref = dose predicted from a convolutional neural network developed in past work. Validation and automated plans were compared to clinical plans using mean absolute differences (

MAD
=

1
N

∑

n
=
1

N

abs

x
n

−

x
n

′

) over all voxels (xn
= Dose, N = #voxels) and DTs (xn
= DT, N = #dwell positions), mean differences (MD) in organ D
2cc and high-risk CTV D90 over all patients (where positive indicates higher clinical dose), and mean Dice similarity coefficients (DSC) for 100% isodose contours. Main results. Validation plans agreed well with clinical plans (MADdose = 1.1%, MADDT = 4 s or 0.8% of total plan time, D
2cc MD = −0.2% to 0.2% and D90 MD = −0.6%, DSC = 0.99). For automated plans, MADdose = 6.5% and MADDT = 10.3 s (2.1%). The slightly higher clinical metrics in automated plans (D
2cc MD = −3.8% to 1.3% and D90 MD = −5.1%) were due to higher neural network dose predictions. The overall shape of the automated dose distributions were similar to clinical doses (DSC = 0.91). Significance. Automated planning with 3D dose predictions could provide significant time savings and standardize treatment planning across practitioners, regardless of experience.
Enhancement of K-shell spectroscopy for temperature measuring of isochorically heated matter in the sub-keV range
Authors: Martynenko A S , Pikuz T A , Skobelev I Yu , Pikuz S A , Iwata N , Johzaki T , Kawanaka J , Law K F F , Fujioka S , Kodama R , Morace A
Published: March 2023

Both K-shell x-ray emission spectroscopy and fluorescence spectroscopy are well-accepted diagnostics for experimental studies of warm dense matter and hot dense matter (HDM). Until now, however, this diagnosis has been used for the study of dense matter with temperatures lower than 100 eV or with temperatures above 1 keV. In this work, we have demonstrated the possibility of using K-shell emission spectroscopy for an intermediate temperature range of 100s eV to study dense plasma. Here, we discuss an analysis of the HDM emission spectra of a solid-state copper with temperatures up to a few hundreds of electronvolts heated by laser-accelerated charged particles.