bluuebunny/crossref_metadata_2025 huggingface dataset:
A Discretize-then-Optimize Approach to PDE-Constrained Shape Optimization
Authors: Herzog Roland , Loayza-Romero Estefanía
Published: October 2023

We consider discretized two-dimensional PDE-constrained shape optimization problems, in which shapes are represented by triangular meshes. Given the connectivity, the space of admissible vertex positions was recently identified to be a smooth manifold, termed the manifold of planar triangular meshes. The latter can be endowed with a complete Riemannian metric, which allows large mesh deformations without jeopardizing mesh quality; see R. Herzog and E. Loayza-Romero, Math. Comput. 92 (2022) 1-50. Nonetheless, the discrete shape optimization problem of finding optimal vertex positions does not, in general, possess a globally optimal solution. To overcome this ill-possedness, we propose to add a mesh quality penalization term to the objective function. This allows us to simultaneously render the shape optimization problem solvable, and keep track of the mesh quality. We prove the existence of a globally optimal solution for the penalized problem and establish first-order necessary optimality conditions independently of the chosen Riemannian metric. Because of the independence of the existence results of the choice of the Riemannian metric, we can numerically study the impact of different Riemannian metrics on the steepest descent method. We compare the Euclidean, elasticity, and a novel complete metric, combined with Euclidean and geodesic retractions to perform the mesh deformation.
The Childhood Opportunity Index's Association with Adverse Pregnancy and Newborn Outcomes in Nulliparous Persons
Authors: Abraham Olivia C. , Jampa Alekhya , Quinney Sara K. , Haas David M.
Published: October 2023

Objective The objective of the study was to determine if using a novel measure of social determinants of health, the Childhood Opportunity Index (COI), at the time of delivery was associated with development of adverse pregnancy outcomes (APO) in nulliparous pregnant persons.

Study Design Data were extracted from the 779 participants from a single nuMoM2b (Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be) study site, a prospective cohort study designed to identify contributors to APOs. Residential address information at delivery was linked to the location's COI. The overall composite and component scores in education, health and environmental, and socioeconomic indices were recorded. APOs of interest included preterm birth, hypertensive disorders of pregnancy, small for gestational age at birth, stillbirth, and gestational diabetes. Participant characteristics were compared by COI category and the association of COI with APOs was analyzed by logistic regression, controlling for age and self-reported race/ethnicity.

Results The overall COI distribution was very low (45%), low (17%), moderate (10%), high (15%), and very high (13%). A total of 329 (43.5%) participants experienced at least one APO. Overall COI was associated with developing an APO (p = 0.02). Each component score was also associated with developing APOs and with race/ethnicity (p < 0.05). Compared with higher COI categories, an overall low or very low categorized location was independently associated with developing an APO (odds ratio: 1.636, 95% confidence interval: 1.16–2.31). Adjusting for gestational age at birth, those in lower COI areas had newborns with lower birth weight, birth length, and head circumference (estimate [95% confidence interval] birth weight: −0.0005 g [−0.0008 to −0.0001]; length: −0.065 cm [−0.124 to −0.0091]; head circumference: −0.123 cm [−0.208 to −0.045]). COI was not associated with other newborn outcomes.

Conclusion COI, a marker for social determinants of health, is independently associated with APOs. The COI may be a tool for risk stratification for pregnant people to help with APO-reducing strategies.

Key Points
Bland Embolization and Transarterial Chemoembolization in Hepatocarcinoma
Authors: Holguín Holguín Alfonso Jose , Toro Gutierrez Juan Sebastián , Bustamante-Cristancho Luis Alfonso , Alvarez Saa Tatiana , Camacho Juan C.
Published: October 2023

Hepatocarcinoma (HCC) is the main cause of morbidity and mortality worldwide in patients with cirrhosis. Eighty percent of cases worldwide are due to infections with hepatitis B and C viruses, but nonalcoholic steatohepatitis (NASH) is projected to be an important etiology. It is usually diagnosed in advanced stages, only 15% of patients are surgical candidates, and up to 35% can receive only supportive care. This pathology has changed over time with the significant advances in treatment alternatives that can improve life expectancy for patients who are not surgical candidates. Therapeutic alternatives are available based on staging according to different models and the Barcelona Clinic Liver Cancer (BCLC) staging system. Systemic pharmacological options (neoadjuvant, adjuvant, and hormonal therapy), surgical options, and locoregional therapies have been developed; all these interventions have been directed to increase the life expectancy of some patients with variable results. Regional therapies include transarterial embolization (TAE) or bland embolization, transarterial infusion chemotherapy, conventional transarterial chemoembolization (TACE), drug-eluting bead transarterial chemoembolization (DEB-TACE), and transarterial radioembolization, with no substantial difference in outcomes between patients treated with TACE and those receiving DEB-TACE, but benefits of lower systemic adverse effects and improved of quality-adjusted life years measure with DEB-TACE. With the addition of immunotherapy to these interventions, the outcomes are expected to be even more impactful on main outcomes such as survival and disease-free survival.
Cognitive Biases and Shared Decision Making in Acute Brain Injury
Authors: Steinberg Alexis , Fischhoff Baruch
Published: October 2023

Many patients hospitalized after severe acute brain injury are comatose and require life-sustaining therapies. Some of these patients make favorable recoveries with continued intensive care, while others do not. In addition to providing medical care, clinicians must guide surrogate decision makers through high-stakes, emotionally charged decisions about whether to continue life-sustaining therapies. These consultations require clinicians first to assess a patient's likelihood of recovery given continued life-sustaining therapies (i.e., prognosticate), then to communicate that prediction to surrogates, and, finally, to elicit and interpret the patient's preferences. At each step, both clinicians and surrogates are vulnerable to flawed decision making. Clinicians can be imprecise, biased, and overconfident when prognosticating after brain injury. Surrogates can misperceive the choice and misunderstand or misrepresent a patient's wishes, which may never have been communicated clearly. These biases can undermine the ability to reach choices congruent with patients' preferences through shared decision making (SDM). Decision science has extensively studied these biases. In this article, we apply that research to improving SDM for patients who are comatose after acute brain injury. After introducing SDM and the medical context, we describe principal decision science results as they relate to neurologic prognostication and end-of-life decisions, by both clinicians and surrogates. Based on research regarding general processes that can produce imprecise, biased, and overconfident prognoses, we propose interventions that could improve SDM, supporting clinicians and surrogates in making these challenging decisions.
A neutron beam monitor based on ceramic gas electron multiplier with high spatial resolution for low flux measurements
Authors: Tan Jinhao , Zhou Jianrong , Zhu Lin , Zhou Xiaojuan , Zeng Lixin , Xiao Liang , Xia Yuanguang , Xu Hong , Jiang Xingfen , Yang Wenqin , Wang Yanfeng , Yang Gui-an , Xie Yuguang , Teng Haiyun , Li Jiajie , Qiu Yongxiang , Shen Peixun , Wang Songlin , Liu Yang , Zhu Jingtao , Zhuang Jian , Zhao Yubin , Sun Zhijia , Song Yushou , Chen Yuanbo
Published: October 2023

Neutron scattering instruments play an important role in studying the inner structure of materials. A neutron beam monitor is a detector commonly used in a neutron scattering instrument. The detection efficiency for most neutron beam monitors is quite low (10−4–10−6). However, in some experiments with a low neutron flux, such as small angle neutron scattering (SANS) and inelastic neutron scattering experiments, a neutron beam monitor with a higher detection efficiency (∼1% for thermal neutrons) is required to reduce the duration of the experiment. To meet this requirement, a ceramic gas electron multiplier-based neutron beam monitor equipped with a 1 µm 10B4C neutron converter was developed in this study. Its performance was determined both experimentally and in simulations. The detection efficiency in the wavelength range of 1.8–5.5 Å was measured experimentally and was confirmed by the simulation results. An algorithm based on event selection and position reconstruction was developed to improve the spatial resolution to about 1 mm full-width-half-maximum. The wavelength spectrum was measured in beamline 20 (BL20) and agreed well with the results obtained using a commercial monitor. The maximum counting rate was 1.3 MHz. The non-uniformity over the whole 100 × 100 mm2 active area was determined to be 1.4%. Due to the excellent performance of this monitor, it has been used in several neutron instruments, such as the SANS and the High-Energy Direct-Geometry Inelastic Spectrometer instruments in the China spallation neutron source.
Local well-posedness of the Einstein-Yang-Mills system in constant mean extrinsic curvature spatial harmonic generalized Coulomb gauge
Authors: Mondal Puskar
Published: October 2023

We study the local well-posedness of the Einstein-Yang-Mills equations in constant mean extrinsic curvature spatial harmonic generalized Coulomb gauge. In this choice of gauge, the complete Einstein-Yang-Mills equations reduce to a coupled elliptic-hyperbolic system. We establish the existence of a unique, local, continuous-in-time solution to this coupled system. This yields an “in time” continuation criteria of the solutions which are to be used in the potential future proof of improved continuation criteria for this coupled system utilizing Moncrief’s light cone estimate technique.
Skyrme crystals with massive pions
Authors: Harland Derek , Leask Paul , Speight Martin
Published: October 2023

The crystalline structure of nuclear matter is investigated in the standard Skyrme model with massive pions. A semi-analytic method is developed to determine local minima of the static energy functional with respect to variations of both the field and the period lattice of the crystal. Four distinct Skyrme crystals are found. Two of these were already known–the cubic lattice of half-skyrmions and the α-particle crystal–but two are new. These new solutions have lower energy per baryon number and less symmetry, being periodic with respect to trigonal but not cubic period lattices. Minimal energy crystals are also constructed under the constraint of constant baryon density, and it is shown that the two new non-cubic crystals tend to chain and multi-wall solutions at low densities.
Enhancement of near edge luminescence in cadmium ions doped CsPbCl3 single crystals
Authors: Pidhornyi O. , Chornodolskyy Ya. , Pushak A. , Smortsova Y. , Kotlov A. , Antonyak O. , Demkiv T. , Gamernyk R. , Voloshinovskii A.
Published: October 2023

Cd2+ cation doped CsPbCl3 single crystals were synthesized, and their luminescent properties were investigated under excitation with synchrotron radiation quanta with energy greater than Eg and at a sample temperature of 12 K. Pure single crystals exhibit a narrow band of exciton emission at 416.7 nm. Doping the single crystals leads to a high-energy shift of the excitonic luminescence, the appearance of new luminescent bands, the broadening of the luminescent bands, an increase in the decay time constants, and a significant enhancement of the luminescence intensity. The observed changes in luminescent parameters upon doping are discussed in terms of the crystal structure ordering, a decrease in the number of defects responsible for capturing charge carriers at the stage of electronic excitation thermalization, and a decrease in defects that quench excitonic luminescence. Doped single crystals with decay times of the order of 0.4 ns and intensities that significantly exceed the intensity of pure single crystals can be promising scintillation materials for positron emission tomography in the time-of-flight mode.
Ion detector of time-of-flight mass spectrometer with registration of leading and trailing edges
Authors: Filatov V. V. , Filatov S. V. , Pikhtelev A. R. , Zhu H. , Sulimenkov I. V. , Huang Z. , Brusov V. S. , Kozlovskiy V. I.
Published: October 2023

The accuracy of the ion flight time measurement in the time-of-flight mass spectrometer is critical to achieving high resolution. The pulse amplitude variation of the detector pulses leads to the registration time spread at a given pulse detection threshold. This time spread can be eliminated by determining the position of the pulse apex. To determine the position of the pulse apex, the output of the ion detector is fed simultaneously to the two channels of the time-to-digital converter. In this case, the first channel is set to register the leading edge, and the second channel is set to register the trailing edge of the pulse. Using a simple processing of the received data, the position of the pulse tip is determined. Thus, the dependence of the temporal position of the peak on the pulse amplitude is largely eliminated. Examples are given, and the efficiency of using this algorithm to increase the resolution of time-of-flight mass spectral peak registration is demonstrated.
Influence of thermal stratification on the transport of polydispersed expiratory particles
Authors: Monka Aleksandra , Fraga Bruño , Soper David , Hemida Hassan
Published: October 2023

The fluid dynamics of expiratory events are complex, and understanding how indoor air conditions affect this and the spread of exhaled material is crucial to the prevention of large-scale spread of diseases. It is known that thermal stratification can trap contaminants in the lower levels of a room; however, there is a lack of studies that investigate the influence of vertical temperature gradients on the transport of expiratory particles at room scale. To this effect, we used Eulerian–Lagrangian large-eddy simulations to investigate the effect of thermal stratification on the transport of polydispersed expiratory particles during speaking in two different sized rooms. Cases with increasing temperature gradient were compared to an isothermal base case, and the influence of stratification on the exhalation jet and the particles suspended within is analyzed. The particle volume fraction was computed to quantify the spatiotemporal evolution of different particle size categories. Our results show that thermal stratification leads to an increased concentration of aerosols in the breathing zone and extends their forward reach. Aerosols up to a size threshold between 12 and 20 μm are locked up at different heights by stratification—beyond this threshold, they fall out continuously. In all cases, aerosols <20 μm traveled up to 4 m from the source, showing that physical distancing guidelines alone may be inadequate for controlling cross-infection risk for long-term exposures. Particles >60 μm are unaffected by stratification and do not follow a ballistic trajectory, falling out within 0.5 m of the infectious individual in all cases.
Experimental investigation on tip vortex cavity deformation and flow dynamics using high-speed imaging and laser Doppler velocimetry measurements
Authors: Simanto R. I. A. , Hong Ji-Woo , Ahn Byoung-Kwon , Jeong So-Won
Published: October 2023

Cavitation affects engineering applications relating to aquatic operations. Tip vortex cavitation (TVC) leads to several technical problems, such as efficiency loss and noise. Hence, there is a need for a comprehensive understanding of the formation mechanism, shape distortions, and underlying physical phenomena of TVC. The dispersion relation of inertial waves on inviscid cavitating vortices is a valuable tool for predicting various TVC shapes. This study explains the patterns of flow around the tip of an elliptical foil and the cavity shape deformations under different flow conditions through experimental analysis. Experiments are conducted using a National Advisory Committee for Aeronautics hydrofoil in the cavitation tunnel at Chungnam National University. The appearance, development, and shapes of vortex cavitation are closely examined using high-speed imaging technology. There is good agreement between the vortex cavity shapes captured by this high-speed imaging and those derived in previous studies. Using laser Doppler velocimetry (LDV) measurements and analysis through image processing of high-speed images, we compare the vortex core trajectories in cavitating and non-cavitating conditions. There is a good match between the two, demonstrating the feasibility of predicting the flow behaviors around vortex cavities using LDV data. As the noise from the TVC is considered a significant source of underwater radiated noise we also measured sound pressure level, which exhibits abrupt changes at specific cavitation numbers, supporting the occurrence of the singing vortex phenomenon and highlighting its sensitivity to small variations in flow conditions. Furthermore, we obtain precise measurements of the instantaneous TVC diameter under different cavitation numbers, allowing the physical functionality of distinct TVC shapes to be determined. Our results significantly extend the scientific understanding of the flow around TVC and the fundamental causes of TVC distortions.
Whistler heat flux instability governed interaction of anisotropic beam electrons in electromagnetic Vlasov simulations
Authors: Paul Anjan , Sharma Devendra
Published: October 2023

The kinetic instability of whistlers in a warm plasma, arising from electron temperature anisotropy with respect to directions parallel and perpendicular to the magnetizing field, is studied. Whistlers resonantly interacting with the electron beams, for example, the fast electrons accelerated by strong parallel electric fields and the so-called runaway electrons in a tokamak, are strong players in the schema of thermalization of stellar winds and mitigation of fast electrons in tokamak disruption events. As an evidence of their role in runaway mitigation, most fusion plasma experiments are found to show a threshold magnetic field strength for the generation of runaways. In many of these examples, the faster primary runaways produce a secondary runaway beam having an avalanche-like non-thermal velocity distribution. The electromagnetic Vlasov simulations presented here self-consistently examine the collisionless interaction of anisotropic electron beams, including an avalanche-like beam distribution, with parallel propagating whistlers and dependence of this process on the magnetic field strength. Analysis of the interaction process includes comparison with the simulations done using more analytically accessible anisotropic bulk and beam electron distributions, namely, the bi-Maxwellian and bi-kappa, for the reference.
Darboux transformations of the modified BKP hierarchy by fermionic approach
Authors: Guo Weici , Chen Mengyao , Yang Yi , Cheng Jipeng
Published: October 2023

The modified BKP (mBKP) hierarchy is an important integrable hierarchy related with BKP hierarchy. Darboux transformation is a powerful method to obtain various solutions of integrable systems. But for mBKP hierarchy, it is usually very difficult to construct the corresponding Darboux transformations, since it has a more complicated constraint on the Lax operator, compared with the BKP hierarchy. In this paper, we use the fermionic approach to obtain the explicit Darboux transformation operators of the mBKP hierarchy starting from the changes in tau functions. Also we investigate the relations among these new Darboux transformation operators. It is usually very difficult to convert the changes in tau functions to the ones in the Lax operator, while here we provide one successful example.
Spectral-selective near-infrared photothermal detector enabled by integrating graphene-Au nanorods hybrid on a thermistor
Authors: Yang Kai , Kang Shenghui , Wu Xiaoyu , Liu Bohua , Sun Chongling , Wang Yanyan
Published: October 2023

Near-infrared (NIR) detectors with high sensitivity and spectral selectivity are highly desired in various applications. In this work, a photothermal detector with high NIR sensitivity and spectral selectivity was developed by simply modifying a photothermal layer of reduced graphene oxide-Au nanorods (rGO-AuNRs) hybrid on a thermistor, which can convert the light energy into heat and reflect as resistance changes of a thermistor. Owing to the plasmon coupling of the two materials, the obtained rGO-AuNRs hybrid not only has remarkable photothermal conversion efficiency but also exhibits dependence on spectral response. Thus, benefiting from the excellent performance of the hybrid, the fabricated detector is sensitive to illumination in the wavelength range from 700 to 1000 nm with the highest photoresponsivity of 2.50 × 105 Ω·W−1. The photothermal detector presented in this work will provide a simple and inexpensive alternative for NIR detector development.
An efficient framework for solving forward and inverse problems of nonlinear partial differential equations via enhanced physics-informed neural network based on adaptive learning
Authors: Guo Yanan , Cao Xiaoqun , Song Junqiang , Leng Hongze , Peng Kecheng
Published: October 2023

In recent years, the advancement of deep learning has led to the utilization of related technologies to enhance the efficiency and accuracy of scientific computing. Physics-Informed Neural Networks (PINNs) are a type of deep learning method applied to scientific computing, widely used to solve various partial differential equations (PDEs), demonstrating tremendous potential. This study improved upon original PINNs and applied them to forward and inverse problems in the nonlinear science field. In addition to incorporating the constraints of PDEs, the improved PINNs added constraints on gradient information, which further enhanced the physical constraints. Moreover, an adaptive learning method was used to update the weight coefficients of the loss function and dynamically adjust the weight proportion of each constraint term. In the experiment, the improved PINNs were used to numerically simulate localized waves and two-dimensional lid-driven cavity flow described by partial differential equations. Meanwhile, we critically evaluate the accuracy of the prediction results. Furthermore, the improved PINNs were utilized to solve the inverse problems of nonlinear PDEs, where the results showed that even with noisy data, the unknown parameters could be discovered satisfactorily. The study results indicated that the improved PINNs were significantly superior to original PINNs, with shorter training time, increased accuracy in prediction results, and greater potential for application.
Investigation on the entropy production distribution in a multiphase pump considering gas–liquid two-phase velocity slip
Authors: Li Chen-Hao , Wu Xi-Tong , Luo Xing-Qi , Feng Jian-Jun , Zhu Guo-Jun
Published: October 2023

To study the energy loss characteristics of a semi-open mixed-flow multiphase pump, an improved entropy generation theory considering the slip velocity was established to locate local areas with high energy loss. The relationships among local entropy generation, phase interface entropy generation, wall entropy generation, and unstable flow were analyzed for each component. The results showed that magnitude of interface entropy generation was similar to turbulent entropy generation and wall entropy generation, which could not be ignored. The interface entropy generation was mainly distributed at the leading edge, trailing edge, hub, and blade tip clearance. With an increased inlet gas volume fraction, the proportion of interfacial entropy production loss to total entropy production loss increased. As the inlet gas volume fraction increased to 30%, the interface entropy generation loss accounted for 70% of the local entropy generation loss at leading edge and 63% at trailing edge. The high interface entropy generation zone at the tip clearance region began to extend from the pressure side of the blade to the suction side of the blade. During the evolution of tip leakage vortex, the generation, unstable stretching, and breakup–regeneration stages were accompanied by a large loss of interface entropy generation.
Presence of a chiral soliton lattice in the chiral helimagnet MnTa3S6
Authors: Miyagi Y. , Jiang J. , Ohishi K. , Kawamura Y. , Suzuki J. , Alshalawi D. R. , Campo J. , Kousaka Y. , Togawa Y.
Published: October 2023

Chiral helimagnetism was investigated in transition-metal intercalated dichalcogenide single crystals of MnTa3S6. Small-angle neutron scattering (SANS) experiments revealed the presence of harmonic chiral helimagnetic order, which was successfully detected as a pair of satellite peaks in the SANS pattern. The magnetization data are also supportive of the presence of chiral soliton lattice (CSL) phase in MnTa3S6. The observed features are summarized in the phase diagram of MnTa3S6, which is in strong contrast with that observed in other dichalcogenides such as CrNb3S6 and CrTa3S6. The presence of the remanent state provides tunable capability of the number of chiral solitons at zero magnetic field in the CSL system, which may be useful for memory device applications.
Structural diversity in tetranuclear ytterbium-based metal–organic frameworks and their divided net analysis
Authors: Yang Lingyi , Sun Yuqian , Jiang Zhongwen , Rao Yin , Tang Yi , Li Qiaowei
Published: October 2023

Lanthanides such as ytterbium have high and various coordination numbers, which lead to the generation of versatile secondary building units (SBUs) for metal–organic framework (MOF) synthesis. However, the versatility also tends to impose relatively low symmetry and uncertainty on the structures, thus understanding the connectivity modes between the inorganic units and the linkers is essential. In this work, a ditopic linker with an α-amino group is employed to regulate the hydrolysis of Yb(III) to facilitate the generation of SBUs with [Yb4(μ3-OH)4] cores, which further reticulate with the linkers to afford three kinds of MOFs. Analysis of the coordination linkages reveals that the linkers can be divided into three different modes, and the arrangement of the linkers with different modes around the SBUs leads to the structures with completely different nets. Furthermore, linker vacancies are found and quantified in the real crystal structures. In addition, a divided net strategy is used to analyze the nets of the two 8-connected MOFs. By dividing each 8-connected node into a 6-connected node and a 2-connected node, the underlying nets of the two MOFs can be regarded as an integration of a pcu net with infinite zig-zag chains or straight rods.
Effects of water stress on endogenous hormones and free polyamines in different tissues of grapevines (Vitis vinifera L. cv. ‘Merlot’)
Authors: Zhan Zhennan , Wang Ning , Chen Zumin , Zhang Yanxia , Geng Kangqi , Li Dongmei , Wang Zhenping
Published: October 2023

Water stress can affect plant ecological distribution, crop growth and carbohydrate distribution, impacting berry quality. However, previous studies mainly focused on short-term water stress or osmotic stress and few studies paid attention to the responses of grape to long-term water stresses. Grapevines were subjected to no water stress (CK), mild water stress (T1) and moderate water stress (T2). Hundred-berry weight and malic acid content were reduced under T1 and T2; however, glucose and fructose content showed the opposite trend. Endogenous hormones and polyamines (PAs) can regulate plant growth and development as well as physiological metabolic processes. T1 and T2 could increase abscisic acid content, however, indole-3-acetic acid, jasmonate, gibberellins 3 and 4, cytokinin and trans-zeatin contents were slightly decreased. Three species of PAs (putrescine, spermidine and spermine) were detected, presenting obvious tissue specificity. Furthermore, there was a statistically positive correlation relating spermidine content in the pulp with glucose and fructose contents of grape berries; and a negative correlation with organic acid. In summary, water stress had a profound influence on hormonally-driven changes in physiology and berry quality, indicating that endogenous hormones and the PAs play a critical role in the development and ripening of grape berries under water stress.
The inhibitory mechanism of a small protein reveals its role in antimicrobial peptide sensing
Authors: Jiang Shan , Steup Lydia C. , Kippnich Charlotte , Lazaridi Symela , Malengo Gabriele , Lemmin Thomas , Yuan Jing
Published: October 2023

A large number of small membrane proteins have been uncovered in bacteria, but their mechanism of action has remained mostly elusive. Here, we investigate the mechanism of a physiologically important small protein, MgrB, which represses the activity of the sensor kinase PhoQ and is widely distributed among enterobacteria. The PhoQ/PhoP two-component system is a master regulator of the bacterial virulence program and interacts with MgrB to modulate bacterial virulence, fitness, and drug resistance. A combination of cross-linking approaches with functional assays and protein dynamic simulations revealed structural rearrangements due to interactions between MgrB and PhoQ near the membrane/periplasm interface and along the transmembrane helices. These interactions induce the movement of the PhoQ catalytic domain and the repression of its activity. Without MgrB, PhoQ appears to be much less sensitive to antimicrobial peptides, including the commonly used C18G. In the presence of MgrB, C18G promotes MgrB to dissociate from PhoQ, thus activating PhoQ via derepression. Our findings reveal the inhibitory mechanism of the small protein MgrB and uncover its importance in antimicrobial peptide sensing.
Modelling plurilingual instruction through a crosslinguistic-communicative task sequence
Authors: Wouters Isabelle , Woll Nina , Paquet Pierre-Luc
Published: October 2023

This study aims to bridge the gap between ‘communicative’ and ‘plurilingual’ approaches, by providing a means for teachers to integrate learners’ plurilingual repertoires when teaching an additional language (Lx). We developed a model of crosslinguistic instruction embedded within the task-based language teaching approach. It consists of a 4 stages task sequence: input-based task, crosslinguistic consciousness-raising task, output-based task, and recap of the sequence. An iterative process of field testing and analysis (Harvey & Loiselle, 2009) allowed us to refine the model: researchers in-depth analysis (functional field test), implementation of the model in Lx classrooms (empirical field test) and experts assessment (second functional field test). Participant perceptions and evaluations provide an overview of their appreciation of different aspects, which lead to the current version of the model.
Report of the CCRI(II) supplementary international comparison of measurement of activity per unit mass of Cs-134 and Cs-137 in wheat flour (CCRI(II)-S13)
Authors: Yunoki Akira , Miura Tsutomu , Furukawa Rio , Maringer Franz Josef , Wiedner Hannah , Medina Virginia Peyres , Fazio Aldo , Petrucci Andrea , Luca Aurelian , Ioan Mihail-Razvan , Antohe Andrei , Sahagia Maria , Cimpeanu Catalina , Črnič Boštjan , Glavič-Cindro Denis , Nečemer Marijan , Petrovič Toni , Vodenik Branko , Zorko Benjamin , Lutter Guillaume , Marissens Gerd , Lee J M , Lee K B , Lee M K , Heo D H , Hwang S H , Rosa Jerome La , Nour Svetlana , Rooy Milton van , Lubbe Joline , Staden Martin van , Javornik Andrej , Zalesakova Michaela , Ometakova Jarmila , Yeltepe Emin , Hachinohe Mayumi , Hamamatsu Shioka
Published: October 2023

Main text

A supplementary international comparison of measurement of activity per unit mass of Cs-134 and Cs-137 in wheat flour (CCRI(II)-S13) was carried out by CCRI in 2018. The matrix of the sample was wheat harvested in 2011 after the Fukushima Daiichi Nuclear Power Plant accident. No spiking was applied to the sample. Twelve institutes reported their results. Averages of the reported results and the associated uncertainties were obtained using the power-moderated mean. This report describes the supplementary comparison reference value, the degrees of equivalence of the results, the procedures of this comparison, and the sample preparation and measurements by the participants. Successful participation in this comparison by a laboratory may provide evidential support for Calibration and Measurement Capability (CMC) claims for Cs-134 and Cs-137 measured using the laboratory's method(s) used in the comparison or methods calibrated by those used for the comparison.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Hodge duality transformations in tensor-hierarchy formulations
Authors: Nishino Hitoshi , Rajpoot Subhash
Published: October 2023

We show in arbitrary

(
D
−
1
)
+
1

space-time dimensions that duality-transformations are possible in general tensor-hierarchy with field-strengths of arbitrary ranks. We first consider the non-Abelian tensor field-strength

G

μ
1

⋯

μ
n

I

of the potential

B

μ
1

⋯

μ

n
−
1

I

, and its compensator field-strength

H

μ
1

⋯

μ

n
−
1

I

of the potential

C

μ
1

⋯

μ

n
−
2

I

, where

I

is the adjoint index. We next perform duality transformations into their respective Hodge-dual field-strength

M

μ
1

⋯

μ

D
−
n

I

of the potential

K

μ
1

⋯

μ

D
−
n
−
1

I

and the field-strength

N

μ
1

⋯

μ

D
−
n
+
1

I

of the potential

L

μ
1

⋯

μ

D
−
n

I

. As a typical application, we show this to take place in

D
=
3
+
1

dimensions with an N = 1 supersymmetric set consisting of a Yang–Mills vector-multiplet

(

A

μ

I

,

λ

I

)

, an extra vector-multiplet

(

B

μ

I

,

χ
I

)

, and a compensating chiral multiplet

(

C
I

,

ρ
I

,

E
I

)

. The λ

I
and χ

I
are Majorana spinors, and

B

μ

I

is an extra vector with the Proca–Stückelberg scalar CI
, while EI
is a pseudo-scalar. We perform duality-transformations on

B

μ

I

and

 

C
I

to their Hodge-dual fields

 

K

μ

I

and

 

L

μ
ν

I

, respectively, ending up with the new set of multiplets

 
(
A

μ

I

,

λ
I

)
,
 
(
K

μ

I

,

χ
I

)

and

 
(
L

μ
ν

I

,

ρ
I

,

E
I

)

. Another example is the set of multiplets

 
(
A

μ

I

,

λ
I

,
B

μ
ν
ρ

I

)

and

 
(
C

μ
ν

I

,

χ
I

,

φ
I

)

in

 
D
=
3
+
1

. Even though

 
B

μ
ν
ρ

I

has the maximal 4th rank field-strength, its supersymmetric dual system exists with

 
(
A

μ

I

,

λ
I

)

and

 
(

L
I

,

χ
I

,

φ
I

)

after a duality-transformation. Our duality-transformations provide previously-unknown-links among supersymmetric tensor-hierarchy formulations.
Positron re-emission, reflection, and diffraction from W(100) surface at very low energies
Authors: Samarin S N , Petrov V N , Sudarshan K , Guagliardo P , Baraban A P , Williams J F
Published: October 2023

The energy distributions of scattered and re-emitted low-energy positrons from a W(100) surface were measured as a function of incident positron energy from 0 to 25 eV. Given that tungsten has a negative work function of about −3 eV for positrons, one can envisage three scenarios of very low-energy positron scattering from such a surface. First, a positron approaching the sample surface with energy say 1 eV above the vacuum level will see a potential barrier of about 2 eV height and will be reflected back to the vacuum. Second, when the energy of incident positrons increases up to the top of the surface potential barrier (positron work function), they start entering the solid and, therefore, the reflectivity of positrons from the surface reduces. Positrons entering the solid are thermalised within few picoseconds and have a chance to escape back to the vacuum with kinetic energy about 3 eV above the vacuum level undergoing so-called re-emission. Third, coherent scattering of low-energy positrons may occur on the crystal surface, i.e. positron diffraction. All the three scenarios of low-energy positrons scattering are studied here experimentally. Measured spectra are very sensitive to the surface conditions of the sample: they change dramatically after surface oxidation or thin film deposition.
Measuring the permeability of magnetic materials in the GHz region
Authors: Thompson Frank
Published: October 2023

Magnetic materials have always been important in the commercial world and, as our transport systems are switching to electrification from fossil fuels, they are likely to become more so. Relative permeability, μ
r, is one parameter which characterizes such materials and this article discusses some measurements of μ
r, made on powdered iron oxide and two ferrite magnetic materials. Preliminary measured values of μ
r range from 1.5 to 4 and the imaginary part of μ
r, show that magnetic losses occur in the GHz region. An idea for improved measurements is suggested.
Energy transfer and vortex structures: visualizing the incompressible turbulent energy cascade
Authors: McKeown Ryan , Pumir Alain , Rubinstein Shmuel M , Brenner Michael P , Ostilla-Mónico Rodolfo
Published: October 2023

The transfer of kinetic energy from large to small scales is a hallmark of turbulent flows. Yet, a precise mechanistic description of this transfer, which is expected to occur via an energy cascade, is still missing. Several conceptually simple configurations with vortex tubes have been proposed as a testing ground to understand the energy cascade. Here, we focus on incompressible flows and compare the energy transfer occurring in a statistically steady homogeneous isotropic turbulent (HIT) flow with the generation of fine-scale motions in configurations involving vortex tubes. We start by filtering the velocity field in bands of wavenumbers distributed logarithmically, which allows us to study energy transfer in Fourier space and also visualize the energy cascade in real space. In the case of a statistically steady HIT flow at a moderate Reynolds number, our numerical results do not reveal any significant correlation between regions of intense energy transfers and vorticity or strain, filtered in corresponding wavenumber bands, nor any simple self-similar process. In comparison, in the transient turbulent flow obtained from the interaction between two antiparallel vortex tubes, we observe a qualitatively simpler organization of the intense structures, as well as of the energy transfer. However, the correlations between energy transfer and strain are small, and point to complicated dynamics of energy transfer. By imposing a structure at large scales consisting of antiparallel vortex tubes in a statistically steady flow, we observed a picture qualitatively similar to what was observed for the transient flow, but the energy transfer statistics do not reproduce the type of triadic interactions seen in HIT. These results indicate that the specific properties of the large-scale vortical structures affect the way energy is transferred, and may not be fully representative of HIT.
Two-terminal tandem solar cell with Sb2S3/Sb2Se3 absorber pair: achieving 14% power conversion efficiency
Authors: Shrivastav Nikhil , Yadav Vishal , Bhattarai Sagar , Madan Jaya , Hossain M Khalid , Samajdar D P , Dwivedi D K , Pandey Rahul
Published: October 2023

Embarking on a journey toward high solar efficiency, this study delves into a two-terminal tandem solar cell (TSC) featuring Sb2S3/Sb2Se3 as an absorber layer. The tandem setup consists of different bandgap (Eg) absorbers to selectively target photon energies: the top cell employs a wide bandgap material to efficiently absorb high-energy photons, while the bottom cell utilizes a lower bandgap material to capture refined photons transmitted from the top cell. This strategy mitigates thermalization and transparent energy losses by assigning distinct photon absorption and conversion roles to the top and bottom cells. Realizing peak efficiency in a tandem configuration rests on the apt choice of active materials for the top and bottom cells. In this regard, a comprehensive study is presented, introducing a TSC architecture that pairs an Sb2S3-based top cell (Eg 1.7 eV) with a Sb2Se3-based bottom cell (Eg 1.2 eV). Through meticulous analysis, the performance of these cells in the tandem setup is analyzed, employing methods such as filtered spectrum analysis and current-matching strategies. The Sb2S3/Sb2Se3 tandem design incorporates a critical tunnel recombination junction facilitated by an ITO layer. Noteworthy is the investigation’s uncovering of impressive metrics for the tandem device, encompassing an open-circuit voltage (VOC) of 1.58 V, a current density (JSC) of 15.50 mA.cm−2, and a fill factor (FF) of 56.90%. This collective attainment culminates in an extraordinary power conversion efficiency of 14%. The insights gleaned from this study hold substantial promise for the future development of monolithic TSC. By adroitly harnessing the distinctive strengths of Sb2S3 and Sb2Se3 materials within a tandem configuration, a clear trajectory is charted toward momentous advancement in solar energy conversion technology.
Comparison of optimized GeSn/Si heterojunction and GaInAsSb/GaSb thermophotovoltaic cells with similar bandgaps
Authors: Tang Yili , Liu Yonghui , Yuan Chengyang , Tang Liangliang , Shao Jianxiong
Published: October 2023

The bandgap of Ge1−xSnx material can be designed within 0.5 ∼ 0.6 eV with different Sn content, and the characteristic of indirect bandgap of pure Ge will change to direct, which make Ge1−xSnx become a proper and low cost thermophotovoltaic cell material. Here we investigate direct bandgap Ge1−xSnx cells with bandgaps of 0.508 ∼ 0.548 eV. Triple antireflection layers, the surface recombination rate, p–n junction depth, impurity doping concentration, etc are optimized for cell design. The optimal cell structures are adopted for cell performance evaluation under given blackbody radiation within 1000 ∼ 2000 K. Simultaneously, the output power densities of GeSn cells are compared with those of traditional GaInAsSb cells with similar bandgap designs. GeSn cells show comparable performances with GaInAsSb cells over the temperature range of 1000 ∼ 1500 K blackbody radiation, and the efficiencies are 1.01 ∼ 2.49 times over 1500 ∼ 2000 K.
Rapid prediction of lab-grown tissue properties using deep learning
Authors: Andrews Allison E , Dickinson Hugh , Hague James P
Published: October 2023

The interactions between cells and the extracellular matrix are vital for the self-organisation of tissues. In this paper we present proof-of-concept to use machine learning tools to predict the role of this mechanobiology in the self-organisation of cell-laden hydrogels grown in tethered moulds. We develop a process for the automated generation of mould designs with and without key symmetries. We create a large training set with N = 6400 cases by running detailed biophysical simulations of cell–matrix interactions using the contractile network dipole orientation model for the self-organisation of cellular hydrogels within these moulds. These are used to train an implementation of the pix2pix deep learning model, with an additional 100 cases that were unseen in the training of the neural network for review and testing of the trained model. Comparison between the predictions of the machine learning technique and the reserved predictions from the biophysical algorithm show that the machine learning algorithm makes excellent predictions. The machine learning algorithm is significantly faster than the biophysical method, opening the possibility of very high throughput rational design of moulds for pharmaceutical testing, regenerative medicine and fundamental studies of biology. Future extensions for scaffolds and 3D bioprinting will open additional applications.
Sub-picosecond laser surface modification of Ti–Ni alloy and its antibacterial activity
Authors: Saraeva Irina N , Nastulyavichus Alena A , Sozaev Islam V , Tolordava Eteri R , Rudenko Andrey A , Kudryashov Sergey I , Tokmacheva-Kolobova Anastasiia Yu , Gonchukov Sergey A
Published: October 2023

Surface modification of titanium nickelide (Ti–Ni) alloy improves its properties, forming a barrier oxidized/carbonized subsurface layer, which blocks the release of toxic nickel ions. We have modified Ti–Ni alloys by structuring the surface with sub-picosecond laser at different radiation parameters. The modified surface was characterized using scanning electron microscopy and layer-by-layer energy dispersive x-ray spectroscopy. The antibacterial properties of structured surfaces were tested against the planktonic culture of Staphylococcus aureus, and the viability was measured by ‘Live/Dead’ microbiological staining method.
Optoacoustic angiography for noninvasive monitoring of experimental tumor angiogenesis
Authors: Glyavina Anna , Akhmedzhanova Ksenia , Kurnikov Alexey , Khochenkov Dmitry , Khochenkova Yulia , Subochev Pavel , Orlova Anna
Published: October 2023

The paper demonstrates the results of a study of experimental SN-12C xenograft vascular network formation using optoacoustic microscopy. A sevenfold increase in vascularity during tumor growth from days 7 to 121 was shown. The possibility of monitoring the development of individual vessels inside the tumor node has been demonstrated. The data obtained are important for understanding the mechanisms of development of the tumor vascular system and may be useful in testing antiangiogenic therapeutic agents.
Analysis of Surface Wind Speed at Minangkabau International Airport for the period 2011-2020 using the Windrose Method
Authors: Oktavia Shinta , Syafriani  , Dwiridal Letmi , Sudiar Nofi Yendri
Published: October 2023

Weather information is very much needed in flight operations because it is related to the smooth running of the aircraft from takeoff to landing. Weather information required by the runway surface wind data needs as important information in the landing process. Information on the surface wind components determines Minangkabau International Airport’s direction and average surface wind speed pattern. Analysis of changes in surface winds also determines the effect of wind on flight safety, especially in the process of taking off and landing aircraft. Wind direction and speed data obtained are from synoptic observations of the Minangkabau Meteorological Station for ten years (2011-2020). Surface wind data is processed using the windrose method with the WRPLOT (Wind Rose Plots for Meteorological Data) application which shows the direction and difference in wind speed and produces a wind pattern image in the form of a windrose diagram. The results of this study note that the dominant wind blows from the Southwest (203°-248°) with a percentage of 41.97%. The west direction (248°-293°) with a percentage of 27.93%. The south (158°-203°) with a percentage of 13.81%. The prevailing wind speed is 4.08 – 7 knots, with a percentage of 54.8%. The rate of 0.97 – 4.08 knots with a percentage of 38.1%, and the speed that occurs is 7-11.08 knots with a percentage of 6.1%. The condition of the overall average wind direction and speed that occurred from 2011-2022 at Minangkabau International Airport was still in the safe category for the takeoff and landing process.