bluuebunny/crossref_metadata_2025 huggingface dataset:
High-Order Parity Improves the Perinatal Outcome of Twin Deliveries
Authors: Kashani-Ligumsky Lior , Cohen Ronnie , Many Ariel , Elmalech Avshalom , Neiger Ran , Lopian Miriam
Published: March 2023

Objective Twin gestations are associated with an increased risk of obstetric and perinatal complications. We studied the association between parity and the rate of maternal and neonatal complications in twins deliveries.

Study Design We performed a retrospective analysis of a cohort of twin gestations delivered between 2012 and 2018. Inclusion criteria consisted of twin gestation with two nonanomalous live fetuses at ≥24 weeks' gestation and no contraindications to vaginal delivery. Women were divided into three groups based on parity: primiparas, multiparas (parity of 1–4), and grand multiparas (parity ≥5). Demographic data were collected from electronic patient records and included maternal age, parity, gestational age at delivery, need for induction of labor, and neonatal birth weight. The primary outcome was mode of delivery. Secondary outcomes were maternal and fetal complications.

Results The study population included 555 twin gestations. One hundred and three were primiparas, 312 were multiparas, and 140 were grand multiparas. Sixty-seven (65%) primiparas delivered the first twin vaginally, as did 294 (94%) multiparas and 133 (95%) grand multiparas (p <0.05). Thirteen (2.3%) women required delivery of the second twin by cesarean section. Among those who delivered both twins vaginally, there was no significant difference in the average time interval between the delivery of the first and the second twins between the groups. The need for transfusion of blood products was higher in the primiparous group compared with the other two groups (11.6 vs. 2.5 and 2.8%, p < 0.05). The rate of adverse maternal composite outcomes was higher among primiparous women compared with multiparous and grand multiparous (12.6, 3.2, and 2.8%, respectively, p < 0.05). The gestational age at delivery was earlier in the primiparous group compared with the other two groups, and the rate of preterm labor at <34 weeks' gestation was higher among the primiparas. The rate of second twin's 5-minute Apgar's score <7 and the composite adverse neonatal outcome among the primiparous group were significantly higher than the multiparous and grand multiparous groups.

Conclusion Our study demonstrates that there is an association between high-parity and good obstetric outcomes in twin pregnancies; high parity seems to serve as a protective, rather than a risk factor for adverse maternal and neonatal outcomes.

Key Points
Advances in Selected Heterocyclization Methods
Authors: Gevorgyan Vladimir , Rivas Mónica
Published: March 2023

This Account summarizes efforts in our group toward synthesis of heterocycles in the past decade. Selected examples of transannulative heterocyclizations, intermediate construction of reactive compounds en route to these important motifs, and newer developments of a radical approach are outlined.

1 Introduction

2 Transannulative Heterocyclization

2.1 Rhodium-Catalyzed Transannulative Heterocyclization

2.2 Copper-Catalyzed Transannulative Heterocyclization

3 Synthesis of Heterocycles from Reactive Precursors

3.1 Synthesis of Heterocycles from Diazo Compounds

3.2 Synthesis of Heterocycles from Alkynones

4 Radical Heterocyclization

4.1 Light-Induced Radical Heterocyclization

4.2 Light-Free Radical Heterocyclization

7 Conclusion
Survey on the Updated German S3 Guideline for Intensive Care in Cardiac Surgery Patients
Authors: Zajonz Thomas Simon , Habicher Marit , Böning Andreas , Heringlake Matthias , Ender Jörg , Markewitz Andreas , Brenck Florian , Sander Michael
Published: March 2023

Background The German guideline on intensive care treatment of cardiac surgical patients provides evidence-based recommendations on management and monitoring. It remains unclear if, respectively, to which degree the guidelines are implemented into the daily practice. Therefore, this study aims to characterize the implementation of guideline recommendations in German cardiac surgical intensive care units (ICUs).

Methods An internet-based online survey (42 questions, 9 topics) was sent to 158 German head physicians of cardiac surgical ICUs. To compare the effect over time, most questions were based on a previously performed survey (2013) after introduction of the last guideline update in 2008.

Results A total of n = 65 (41.1%) questionnaires were included. Monitoring changed to increased provision of available transesophageal echocardiography specialists in 86% (2013: 72.6%), SvO2 measurement in 93.8% (2013: 55.1%), and electroencephalography in 58.5% (2013: 2.6%). The use of hydroxyethyl starch declined (9.4% vs. 2013: 38.7%), gelatin 4% presented the most administered colloid with 23.4% (2013: 17.4%). Low cardiac output syndrome was primarily treated with levosimendan (30.8%) and epinephrine (23.1%), while norepinephrine (44.6%) and dobutamine (16.9%) represented the most favored drug combination. The main way of distribution was web-based (50.9%), with increasing impact on therapy regimens (36.9% vs. 2013: 24%).

Conclusion Changes were found in all questioned sectors compared with the preceding survey, with persisting variability between ICUs. Recommendations of the updated guideline have increasingly entered clinical practice, with participants valuing the updated publication as clinically relevant.
A novel T-shaped high-power waveguide phase shifter with continuous linear phase adjustment
Authors: Zhuang Qinghe , Xiong Zhengfeng , Yan Feng , Yang Meng , Liu Yingjun
Published: March 2023

A novel T-shaped high-power waveguide phase shifter is investigated in this paper. The phase shifter consists of straight waveguides, four 90° H-bend waveguides, a stretching metal plate, and a metal spacer linked with the stretching metal plate. The entire structure for the phase shifter is symmetrical along both sides of the metal spacer. The phase-shifting principle for the phase shifter is to change the microwave transmission path by moving the stretching metal plate and then realize the linear phase adjustment. An optimal design approach of the phase shifter based on the boundary element method is described in detail. On this basis, a T-shaped waveguide phase shifter prototype with a center frequency of 9.3 GHz is designed. Simulation results show that the phase shifters can achieve 0°–360° linear phase adjustment by altering the distance of the stretched metal plate to 24 mm, and the efficiency of power transmission is more than 99.6%. In the meanwhile, experiments were conducted and the test results are in good agreement with simulation results. The return loss is more than 29 dB, and the insertion loss is less than 0.3 dB at 9.3 GHz in the entire phase-shifting range.
A
δf
PIC method with forward–backward Lagrangian reconstructions
Authors: Campos Pinto M. , Pelz M. , Tournier P.-H.
Published: March 2023

In this work, we describe a δf particle simulation method where the bulk density is periodically remapped on a coarse spline grid using a forward–backward Lagrangian approach. This method is designed to handle plasma regimes where the densities strongly deviate from their initial state and may evolve into general profiles. We describe the method in the case of an electrostatic particle-in-cell scheme and validate its qualitative properties using a classical two-stream instability subject to a uniform oscillating drive.
How NaFTA salt affects the structural landscape and transport properties of Pyrr1,3FTA ionic liquid
Authors: Singh Navneet , Jha Mrityunjay K. , Dhattarwal Harender S. , Kashyap Hemant K.
Published: March 2023

Recently, it has been demonstrated that ionic liquids (ILs) with an asymmetric anion render a wider operational temperature range and can be used as a solvent in sodium ion batteries. In the present study, we examine the microscopic structure and dynamics of pure 1-methyl-1-propylpyrrolidinium fluorosulfonyl(trifluoromethylsulfonyl)amide (Pyrr1,3FTA) IL using atomistic molecular dynamics simulations. How the addition of the sodium salt (NaFTA) having the same anion changes the structural landscape and transport properties of the pure IL has also been explored. The simulated x-ray scattering structure functions reveal that the gradual addition of NaFTA salt (up to 1.2 molal) suppresses the charge alternating feature of the pure IL because of the replacement of the Pyrr+ cations with the Na+ ions. The Na+ ions are majorly found near the oxygen atoms of the anions, but the probability of finding the Na+ ions near these atoms slightly decreases with increasing salt concentration. As expected, the Na+ ions stay away from the Pyrr+ cations. However, the probability of finding the anions around anions increases with increasing salt concentration. The simulated self-diffusion coefficients of the ions in the pure IL reveal slightly faster diffusion of the Pyrr+ cations as compared to the FTA− anions. Interestingly, in the salt solution, despite having smaller size, the diffusion of the Na+ ions is found to be lesser than the Pyrr+ cations and the FTA− anions. The analysis of the ionic conductivity and transport numbers reveals that the fractional contribution of the FTA− anion to the overall conductivity remains nearly constant with increasing salt concentration, but the contribution of Pyrr+ cation decreases and Na+ ion increases.
Ultra-low-frequency waves for below threshold and thousand times threshold flux events
Authors: Shah Asif
Published: March 2023

A recent study by Shah et al. [Astrophys. Space Sci. 366(2), 22 (2021)] explored the effects of large-scale solar wind structures on relativistic electron fluxes in the slot region and categorized the flux events into four classes, including those with the events of maximum peak fluxes, TTF (thousand times threshold flux), and the events of smallest fluxes, BTF (below threshold flux). This study compares ultra-low-frequency (ULF) waves inside a magnetosphere and at the magnetopause boundary for the BTF and TTF events. It is found that during the TTF event, the electron radial drift velocity peaked very early at the position of an inner Van Allen radiation belt (L = 2–3). The delay between the radial velocity peak and the peak of the toroidal mode electric field was 12 min. For the BTF event, strong ULF waves were absent in the outer Van Allen radiation belt. In contrast, peak powers of ULF waves in the outer radiation belt approached 80 (mV/m)2/Hz for the TTF event, and this peak exceeded the peak power of the toroidal mode electric field at the magnetopause boundary (L = 11) for the BTF event. Our findings are critical for understanding the transport of ULF wave-driven charged particles from the magnetopause boundary to the inner magnetosphere.
Droplet-induced optical effects in an opto-microfluidic cross-configuration system
Authors: Zanini Leonardo , Sada Cinzia
Published: March 2023

A comprehensive description of all the optical phenomena occurring when light interacts with a moving dispersed phase in a constrained environment such as a real microfluidic channel is needed to perform a quantitative analysis as well as predictive one. This requires identifying fingerprints in the detected optical signal that are doubtlessly correlated with the shape and content type of the dispersed phase from those connected to uncertainties of the optical detection systems and/or instabilities in the microfluidics apparatus leading to dispersed phase size distribution. This article aims to model all the droplet-induced optical effects in an opto-microfluidic cross-configuration system and quantify how diffraction, transmission, absorbance, and reflection contribute to the overall response in the detected intensity after light-matter interaction. The model has been tested in the case of water droplets dispersed in hexadecane continuous phase as generated in an opto-microfluidic platform where optical waveguides are fully integrated with the microfluidic channels, so that light illuminates the flowing droplets from the channel wall and collected on the opposite side. A critical discussion of the impact of geometry and constrains is proposed as well as the impact of each contribute in terms of fingerprints in the detected signal. The good agreement obtained demonstrates the potentialities of both the derived model and the cross-configuration, getting information on droplet characteristics from the intensity arising from its light interaction.
Molybdenum disulfide under extreme conditions: An ab initio study on its melting
Authors: Saiz Fernan
Published: March 2023

Crystalline molybdenum disulfide has become a central actor in the 2D-materials community due to its promising optoelectronic and thermoelectric properties. Despite the extensive work made in investigating these properties, a vast area of knowledge remains unknown on the structure and dynamics of its disordered phases such as liquid and amorphous. Thus, the goal of this work is to investigate the melting of bulk molybdenum disulfide using ab initio molecular dynamics based on density functional theory. We employ the two-phase and Z-methods to evaluate the melting in a number of conditions. Our results at 1 bar reveal that the two-phase procedure is preferred since it predicts a melting point of 2266.92 K that is directly computed using simulations at constant pressure and energy. In contrast, this temperature is indirectly estimated at 2154.01 K with the Z-method using an interpolation of simulations at constant volume and energy. Nevertheless, we find that both methods are complementary as they allow computing different thermodynamic and structural properties. For instance, we estimate a melting heat of 0.67 eV/atom with the two-phase coexistence route, which shows very good agreement with the value of 0.75 eV/atom obtained from the difference of the internal energies of separate crystalline and liquid ensembles at the same conditions of 1 bar and 2266.92 K. In contrast, the Z-method allows us to determine the influence of pressure on the melting temperature, density, and coordination number with a lower computational cost.
A novel steady-state corona characteristics simulation approach for a sharp rod-type static discharger based on the corona zone range iteration of electrode boundary
Authors: Qiu Shanliang , Zhao Yushun , Huang Yeyuan , Li Zhibao , Duan Zemin
Published: March 2023

This paper presents a simulation approach to solve the steady-state corona model of a rod-type static discharger with a sharp tip. Based on the requirement of charge density distribution on the corona boundary, a novel iteration calculation method is proposed to automatically solve the corona zone range of the electrode boundary that cannot be predetermined for a sharp electrode. Moreover, a recursive calculation strategy that uses the corona convergence solution of some high-voltage parameters as the initial solution is employed to improve the computational stability and efficiency in scanning simulations with different voltage and wind speed parameters. Through the simulation and verification of a typical rod-type static discharger, we observed that the convergence is fast for the boundary range iteration, and the recursive calculation strategy is also effective. In addition, the volt–ampere characteristics and inception voltage obtained using the simulation were in good agreement with the measurement. Through simulation of a static discharger applied in a typical longitudinal wind field environment, we observed that the proposed approach is still effective at wind speeds up to hundreds of m/s.
SAMPL9 blind predictions for toluene/water partition coefficients using nonequilibrium alchemical approaches
Authors: Procacci Piero , Guarnieri Guido
Published: March 2023

We present our blind prediction of the toluene–water partition coefficients in the context of the SAMPL9 challenge. For the calculation of the solvation free energies in water, toluene, and 1-octanol, we used an efficient MD-based nonequilibrium alchemical technique relying on the GAFF2 non-polarizable force field. The method is based on the fast-growth of an initially decoupled solute. Canonical sampling of the associated end-state is efficiently obtained by performing a Hamiltonian replica exchange simulation of the gas-phase solute molecule alone, combined with equilibrium configurations of the solvent. Before submitting the prediction, a pre-assessment of the method and of the force field was made by comparing with the known experimental counterpart the calculated octanol–water partition coefficients using different set of atomic charges. The analysis allowed to optimize our blind prediction for the toluene–water partition coefficients, providing at the same time valid clues for improving the performance and reliability of the non-polarizable force field in free energy calculations of drug-receptor systems.
Immune cells use active tugging forces to distinguish affinity and accelerate evolution
Authors: Jiang Hongda , Wang Shenshen
Published: March 2023

Cells are known to exert forces to sense their physical surroundings for guidance of motion and fate decisions. Here, we propose that cells might do mechanical work to drive their own evolution, taking inspiration from the adaptive immune system. Growing evidence indicates that immune B cells—capable of rapid Darwinian evolution—use cytoskeletal forces to actively extract antigens from other cells’ surfaces. To elucidate the evolutionary significance of force usage, we develop a theory of tug-of-war antigen extraction that maps receptor binding characteristics to clonal reproductive fitness, revealing physical determinants of selection strength. This framework unifies mechanosensing and affinity-discrimination capabilities of evolving cells: Pulling against stiff antigen tethers enhances discrimination stringency at the expense of absolute extraction. As a consequence, active force usage can accelerate adaptation but may also cause extinction of cell populations, resulting in an optimal range of pulling strength that matches molecular rupture forces observed in cells. Our work suggests that nonequilibrium, physical extraction of environmental signals can make biological systems more evolvable at a moderate energy cost.
The Academic Discourse of Mechanical Engineering
Authors: Le Thi Ngoc Phuong , Pham Minh Man , Barlow Michael
Published: March 2023

This volume examines rhetorical conventions employed in mechanical engineering research to understand the knowledge-making principles of the discipline, as well as their expression within the research article. In particular, the study analyses the organisational patterns of mechanical engineering research articles using Swales’s conceptualisation of moves and steps. In addition, the research identifies the phraseology associated with specific moves and steps. The study draws on a corpus of 120 mechanical engineering research articles, equally distributed across two sub-disciplines (mechanical systems and thermal-fluids engineering), three research traditions (experimental, theoretical and mixed methods), and two publication periods (2002–2006 and 2012–2016). It adopts an integrated methodology, intertwining various approaches and perspectives including corpus linguistics, move analysis, discourse analysis and interviews to address two main strands of research enquiry: (i) What are the properties of the rhetorical structures in terms of range, frequency, and length for each section of mechanical engineering research articles? (ii) What effect does sub-discipline, research tradition and publication date have on the rhetorical structure of research articles?
The unintentional body rotation with the Fukuda stepping test is not proportional to the number of steps
Authors: Paquet Nicole , Maheu Maxime
Published: March 2023

Objective

This study was to compare the magnitude and variability of the unintended body rotation at the 20th and 50th step while performing the 50-step Fukuda stepping test (FST50) without and with modifications, i.e. restricted linear displacements and 30° head flexion.

Methods

Kinematic data previously collected from 14 and 20 healthy young adults were analyzed. Body rotation was extracted at the 20th step and the 50th step of the FST50 and the ratio between the two was calculated. The impact of test modifications on rotation was assessed with a two-way ANOVA for repeated measure and the variability of rotation was described with the coefficient of variation (CV).

Results

The ratio of rotation was 0.27 for the FST50 and 0.29 for the modified FST50. The CVs of rotation of were 57.9% and 65.0% at the 20th step and 79.7% and 81.8% at the 50th step for the FST50 and modified FST50, respectively. Modifications to the FST50 did not change the magnitude of rotation (p > .05).

Conclusion

The control of body rotation seems to progressively deteriorates during the FST50. From our results, it appears that a 20-step FST might not be a simple, proportional shortened version of the FST50.
License to kill: Retinoic acid programs T cells for tissue residency
Authors: Heeg Maximilian , Goldrath Ananda W.
Published: March 2023

In this issue of JEM, Qiu et al. (2023. J. Exp. Med. https://doi.org/10.1084/jem.20210923) show that retinoic acid signaling during priming in the mesenteric lymph node licenses CD8+ T cells to develop into small intestinal tissue-resident memory cells, a finding that provides key insights into tissue-specific vaccination strategies.
Toward a “Both-And” Semiotics of Intersectionality: Raciolinguistics beyond White Settler-Colonial Situations
Authors: Babcock Joshua , Ke-Schutte Jay
Published: March 2023

In proposing a “both-and” semiotics of intersectionality, this special issue responds to recent timely studies of white supremacy, anti-Blackness, settler supremacy, and other oppressive systems undertaken by linguistic anthropologists and other critical scholars of language. Contributors to this issue turn our attention toward two pressing concerns that are at stake in the continued theorization of raciolinguistics: First, we insist that the conaturalization of language and race is flexible and expansive, not reductive, narrow, or epiphenomenal. Second, we situate our projects at what has until now been a point of breakdown in raciolinguistic discussions by examining and theorizing raciolinguistic ordering in situations that are reflexively positioned as lying beyond the white settler colonial.
A Raciosemiotics of Appropriation: Transnational Performance of Raciogender among Mexican K-Pop Fans
Authors: Yoo Joyhanna
Published: March 2023

Advancing a raciosemiotics (Smalls 2020) of appropriation, this article examines what happens when raciolinguistically charged signs circulate and are taken up in a context different to their production. Based on face-to-face and digital ethnography of K-pop fans in Mexico, this study presents a multimodal semiotic analysis of fans’ metapragmatic discourses and social media practices. I show how fans orient to the female K-pop idol, a mediatized figure of personhood (Agha 2005; Hiramoto and Kang 2017) indexical of hegemonic cosmopolitan femininity but simultaneously an exotic racialized Other in many non-Korean contexts. My examination of fan discourses and performance on social media treats the characterological figure of the female K-pop idol as a desirable, aspirational racial other for Mexican fans, while attending to the sociohistorical specificities of Asian racialization in the context of Mexico. The characterological figure is shaped by, and must interact with, local racial ideologies. My analysis suggests that such performances allow fans to differentiate themselves from other Mexican youth by demonstrating their knowledge of intra-Asian differences. Moreover, they are able to fashion neoliberal and queer subjectivities, albeit conditionally, through their indexical approximation of K-pop idols.
Three-body harmonic molecule
Authors: Olivares-Pilón H , Escobar-Ruiz A M , Molina F Montoya
Published: March 2023

In this study, the quantum three-body harmonic system with finite rest length R and zero total angular momentum L = 0 is explored. It governs the near-equilibrium S-states eigenfunctions

ψ
(

r

12

,

r

13

,

r

23

)

of three identical point particles interacting by means of any pairwise confining potential

V
(

r

12

,

r

13

,

r

23

)

that entirely depends on the relative distances

r

i
j

=

|

r

i

−

r

j

|

between particles. At R = 0, the system admits a complete separation of variables in Jacobi-coordinates, it is (maximally) superintegrable and exactly-solvable. The whole spectra of excited states is degenerate, and to analyze it a detailed comparison between two relevant Lie-algebraic representations of the corresponding reduced Hamiltonian is carried out. At R > 0, the problem is not even integrable nor exactly-solvable and the degeneration is partially removed. In this case, no exact solutions of the Schrödinger equation have been found so far whilst its classical counterpart turns out to be a chaotic system. For R > 0, accurate values for the total energy E of the lowest quantum states are obtained using the Lagrange-mesh method. Concrete explicit results with not less than eleven significant digits for the states

N
=
0
,
1
,
2
,
3

are presented in the range

0
⩽
R
⩽
4.0

 a.u. In particular, it is shown that (I) the energy curve

E
=
E
(
R
)

develops a global minimum as a function of the rest length R, and it tends asymptotically to a finite value at large R, and (II) the degenerate states split into sub-levels. For the ground state, perturbative (small-R) and two-parametric variational results (arbitrary R) are displayed as well. An extension of the model with applications in molecular physics is briefly discussed.
Resonantly enhanced interatomic Coulombic electron capture in a system of three atoms
Authors: Remme S , Voitkiv A B , Müller C
Published: March 2023

In interatomic Coulombic electron capture, the capture of a free electron at an atomic center is accompanied by the radiationless transfer of the excess energy to a neighboring atom of different species, leading to ionization of the latter. We show that this interatomic process can be strongly enhanced by the presence of an additional third atom, provided the energy of the free-bound capture transition in the first atom is resonant to a dipole-allowed excitation energy in this assisting atom. The relation of the resonantly enhanced three-center electron capture with other processes is discussed, and its dependencies on the incident electron energy and the spatial geometry of the triatomic system are illustrated.
CP-odd and CP-even weak-basis invariants in the presence of vector-like quarks
Authors: Albergaria Francisco , Branco G C , Bastos José Filipe , Silva-Marcos J I
Published: March 2023

We propose a minimal set of weak-basis invariants in an extension of the standard model (SM) where one up-type isosinglet vector-like quark is introduced, which allows us to obtain all the physical content of the CKM matrix. We present CP-odd invariants of lower order in mass than the one in the SM, which may have important consequences for Baryogenesis. We study the ECL, where the two lightest generations have vanishing mass, showing that in this extension, contrary to the SM, CP violation can be observed in collisions much above the electroweak scale.
Intelligent fault diagnosis of planetary gearboxes under time-varying conditions based on dynamic adversarial balance adaptation with multi-label information confusion
Authors: Han Songjun , Feng Zhipeng
Published: March 2023

Intelligent diagnosis methods based on big data have been extensively applied in the fault diagnosis of rotating equipment such as planetary gearboxes. Most of these methods usually satisfy the condition of independent identically distribution among the training and diagnosis data. However, the data distribution in the actual diagnosis task struggles to satisfy the above conditions due to the lack of fault data, missing label information and the feature differences within different signals, thus increasing the difficulty of cross-condition fault diagnosis in small sample sets. Therefore, we propose a dynamic adversarial balance adaptation method with multi-label information confusion (MLC-DABA) for diagnosing planetary gearbox faults under time-varying conditions. In the signal preprocessing process, we transform the nonstationary timing signals into two-dimensional time-frequency matrices for the feature learning of networks, which avoids the frequency characteristic mess caused by frequency overlap. Moreover, we adopt a balance adaptation algorithm to dynamically evaluate the feature distribution between source and target tasks through the domain labels and category labels, thus establishing a balanced adaptation relationship between the feature distributions of both tasks. This dynamic adversarial training mechanism can tap more domain-invariant feature information to measure the distribution distance among tasks, thus closing the feature differences in different tasks and increasing the generalization of source tasks to the data distribution in target tasks. The proposed method is verified in planetary gearbox experiments. Experimental analysis results indicate that the diagnostic performance of MLC-DABA outperforms other comparison methods in terms of accuracy and training robustness.
Patient-specific Monte Carlo-based organ dose estimates in spiral CT via optical 3D body scanning and adaptation of a voxelized phantom dataset: proof-of-principle
Authors: Maddaloni Francesca Saveria , Sarno Antonio , Mettivier Giovanni , Clemente Stefania , Oliviero Caterina , Ricciardi Roberta , Varallo Antonio , Russo Paolo
Published: March 2023

Objective. We present a method for personalized organ dose estimates obtained before the computed tomography (CT) exam, via 3D optical body scanning and Monte Carlo (MC) simulations. Approach. A voxelized phantom is derived by adapting a reference phantom to the body size and shape measured with a portable 3D optical scanner, which returns the 3D silhouette of the patient. This was used as an external rigid envelope for incorporating a tailored version of the internal body anatomy derived from a phantom dataset (National Cancer Institute, NIH, USA) matched for gender, age, weight, and height. The proof-of-principle was conducted on adult head phantoms. The Geant4 MC code provided estimates of the organ doses from 3D absorbed dose maps in the voxelized body phantom. Main results. We applied this approach for head CT scanning using an anthropomorphic voxelized head phantom derived from 3D optical scans of manikins. We compared the estimates of head organ doses with those provided by the NCICT 3.0 software (NCI, NIH, USA). Head organ doses differed up to 38% using the proposed personalized estimate and MC code, with respect to corresponding estimates calculated for the standard (non-personalized) reference head phantom. Preliminary application of the MC code to chest CT scans is shown. Real-time pre-exam personalized CT dosimetry is envisaged with adoption of a Graphics Processing Unit-based fast MC code. Significance. The developed procedure for personalized organ dose estimates before the CT exam, introduces a new approach for realistic description of size and shape of patients via voxelized phantoms specific for each patient.
A novel algorithm to assess the quality of 12-lead ECG recordings: validation in a real telecardiology application
Authors: de Moraes Jermana L , Paixão Gabriela M M , Gomes Paulo R , Mendes Eduardo M A M , Ribeiro Antônio Luiz P , Beda Alessandro
Published: March 2023

Objective. Automatic detection of Electrocardiograms (ECG) quality is fundamental to minimize costs and risks related to delayed diagnosis due to low ECG quality. Most algorithms to assess ECG quality include non-intuitive parameters. Also, they were developed using data non-representative of a real-world scenario, in terms of pathological ECGs and overrepresentation of low-quality ECG. Therefore, we introduce an algorithm to assess 12-lead ECG quality, Noise Automatic Classification Algorithm (NACA) developed in Telehealth Network of Minas Gerais (TNMG). Approach. NACA estimates a signal-to-noise ratio (SNR) for each ECG lead, where ‘signal’ is an estimated heartbeat template, and ‘noise’ is the discrepancy between the template and the ECG heartbeat. Then, clinically-inspired rules based on SNR are used to classify the ECG as acceptable or unacceptable. NACA was compared with Quality Measurement Algorithm (QMA), the winner of Computing in Cardiology Challenge 2011 (ChallengeCinC) by using five metrics: sensitivity (Se), specificity (Sp), positive predictive value (PPV), F
2, and cost reduction resulting from adoption of the algorithm. Two datasets were used for validation: TestTNMG, consisting of 34 310 ECGs received by TNMG (1% unacceptable and 50% pathological); ChallengeCinC, consisting of 1000 ECGs (23% unacceptable, higher than real-world scenario). Main results. Both algorithms reached a similar performance on ChallengeCinC, although NACA performed considerably better than QMA in TestTNMG (Se = 0.89 versus 0.21; Sp = 0.99 versus 0.98; PPV = 0.59 versus 0.08; F
2 = 0.76 versus 0.16 and cost reduction 2.3 ± 1.8% versus 0.3 ± 0.3%, respectively). Significance. Implementing of NACA in a telecardiology service results in evident health and financial benefits for the patients and the healthcare system.
Experiments and non-linear MHD simulations of hot vertical displacement events in ASDEX-Upgrade
Authors: Schwarz N , Artola F J , Hoelzl M , Bernert M , Brida D , Giannone L , Maraschek M , Papp G , Pautasso G , Sieglin B , Zammuto I , Upgrade Team the ASDEX
Published: March 2023

Hot vertical displacement events (VDEs) are one of the worst case scenarios for high-current tokamaks as they are associated with large heat loads and electro-magnetic forces. Non-linear magneto-hydrodynamic (MHD) simulations of the thermal and current quench can help to understand their dynamics and consequences. In order to make predictions for future devices, the validation of codes against present machines is crucial. Dedicated experiments were performed in ASDEX Upgrade to provide a basis for simulations with the non-linear extended MHD code JOREK. 2D as well as non-axisymmetric simulations at realistic parameters can reproduce quantities like the edge safety factor q
95 at the thermal quench onset, the halo current magnitude and the level of vertical forces, while the exact width of the halo current area requires more sophisticated boundary conditions and is left for future work. Small horizontal forces are observed during the hot VDEs in the experiment as well as in the simulations.
Data-driven design and optimization of ultra-tunable acoustic metamaterials
Authors: Huo Jindong , Wang Yifei , Wang Ningzhen , Gao Wenqiang , Zhou Jierui , Cao Yang
Published: March 2023

This paper presents a data-driven design and optimization of acoustic metamaterials with three-phase materials for highly tunable wave transmission. The geometry of representative unitcell is defined by the trigonometric series function to describe an arbitrary shape with symmetry, which enables the unitcell to achieve a large sub-wavelength bandgap. We propose a lightweight and efficient algorithm, ‘decoupled gradient decent (DGD)’, to search for the optimal design and uncover the ‘best’ shape features—the interface curvature—in tuning the wave transmission. As a result, the host composite can partly overlap the individual cell’s bandgap and achieve a wide frequency gap that forbids wave transmission, namely a passive tunability. Another advantage of the trigonometric series designed shape is the high flexibility. A slight surface pressure obviously deforms the unitcell and shifts its band structure. Our simulation shows that a moderate pressure dramatically changes the frequency forbidding gap for both traversal and longitudinal wave transmissions, which indicates an active tunability. The surface deformation can be applied by either a mechanical pressure or external electric field if the composite uses a dielectric substrate. Therefore, this study opens a sandbox of manipulating wave transmission through the topology and structure optimization in applications such as seismic damping (Hz), noise insulating (kHz) and ultrasound imaging (MHz).
Toward improved loading, cooling, and trapping of molecules in magneto-optical traps
Authors: Langin T K , DeMille D
Published: March 2023

Recent experiments have demonstrated direct cooling and trapping of diatomic and triatomic molecules in magneto-optical traps (MOTs). However, even the best molecular MOTs to date still have density 10−5 times smaller than in typical atomic MOTs. The main limiting factors are: (i) inefficiencies in slowing molecules to velocities low enough to be captured by the MOT, (ii) low MOT capture velocities, and (iii) limits on density within the MOT resulting from sub-Doppler heating (Devlin and Tarbutt 2018 Phys. Rev. A 90 063415). All of these are consequences of the need to drive ‘Type-II’ optical cycling transitions, where dark states appear in Zeeman sublevels, in order to avoid rotational branching. We present simulations demonstrating ways to mitigate each of these limitations. This should pave the way toward loading molecules into conservative traps with sufficiently high density and number to evaporatively cool them to quantum degeneracy.
DFT study of efficient hydrogen storage on B12@Ca14 cage
Authors: Chen Yi-Sha , Guo Jing-Jing , Liu Peng-Bo , Zhao Hui-Yan , Wang Jing , Liu Ying
Published: March 2023

Hydrogen, as a zero-carbon energy carrier, has attracted considerable attention of scientific community. Therefore, the development of hydrogen storage materials has always been a hot topic. Currently, there have been numerous researches on hydrogen storage performance of boron nanostructures decorated by alkaline-Earth atoms. Here based on first-principles calculations, a core–shell B12@Ca14 structure with D
2h
symmetry has been proposed. Surprisingly, 14 Ca atoms in the metal shell of the B12@Ca14 structure can form a good package for B12 core without aggregation, thus forming a novel hydrogen storage material with all-metal atomic shell, which also provides a new idea for the research of hydrogen storage materials. Molecular dynamics simulation and vibration frequency analysis have been revealed the thermodynamic and kinetic stability of the B12@Ca14 structure. The analysis of binary system illustrates that the structure can be used as a building block for nano-assembly. For the hydrogen storage performance of the structure, the research results show that the B12@Ca14 structure can adsorb about 75 H2 molecules, with a high hydrogen storage mass density of 18.0 wt%. What’s more, non-covalent interaction analysis verifies that H2 molecules are adsorbed by weak interactions.
Impact of yttrium hydride formation on multi-isotopic hydrogen retention by a getter trap for the DONES lithium loop
Authors: Hendricks S.J. , Molla J. , Urgorri F.R. , Carella E.
Published: March 2023

Compliance with imposed hydrogen concentration limits in the lithium loop of the DEMO-Oriented Neutron Source (DONES) requires the installation of an yttrium-based hydrogen trap. To determine an appropriate H-trap design, it is essential to have access to a numerical tool capable of simulating hydrogen transport in the DONES lithium loop connected to an yttrium pebble-bed. In the past, a simplified model was created that allows such calculations when hydrogen concentrations in the lithium are low. However, in certain DONES operating phases, the concentration in the lithium is high and in a range where yttrium dihydride (YH2) formation is likely. Due to the anticipated great impact of YH2 formation on the H-trap performance a new model is developed that includes the mechanism of hydride formation. It is based on a mathematical reproduction of complete pressure-composition isotherms of the Li–H and Y–H systems. Thus, the conditions that trigger YH2 formation are determined and the variation of hydrogen solubility in different yttrium hydride phases is deduced. An approximate concentration-dependent relationship of hydrogen diffusivity in yttrium is derived and incorporated into the model. Simulations are performed to analyze the dynamics of the concentration decrease during purification of the lithium circuit prior to the experimental DONES phase by varying design parameters of the trap. It is found that hydride formation greatly increases the hydrogen gettering capacity of the H-trap and limits the maximum concentration in the lithium. Indeed, YH2 formation may be purposefully triggered to exploit its beneficial properties for DONES. Simulations of the hydrogen purification process during the experimental phase of DONES show that the H-trap must be replaced at least every 28 days to meet tritium limits. This work sets the conditions for the required pebble-bed mass of the H-trap at a given temperature to comply with the DONES safety requirements. Finally, the model is validated by numerical reproduction of experimental results.
Transportation Oriented Development Method: literature review
Authors: Vega Julio , Balcázar Robinson , Guerra Xavier
Published: March 2023

Cities are a wealth production system that attract more and more people in search of a better lifestyle. Migration to cities affects the demand for more housing, services and facilities that, in many cases, imply uncontrolled urban growth, an increase in the number of vehicles, processes of social segregation and effects on natural systems. Indeed, cities are responsible for 70% of greenhouse gas emissions, one of the causes of climate change. Transportation Oriented Development (TOD) is an urban planning model that considers higher density, mixed land use, promotion of public transportation and also promotes a walkable and cycleable environment. This study aims to identify the characteristics of TOD that, from various studies, contribute to the construction of a more efficient and equitable city. The objective is to identify and define the characteristics that build this urban planning approach. A review of the state of the art was carried out in two phases: the first consisted of a bibliometric review based on the Vosviewer software and in the second, 28 articles published in high-impact journals were reviewed according to the Scimago ranking. The results indicate that several of the characteristics of TOD overlap in several studies and that others are not considered at a general level and should be strengthened.
Citizen science as a tool for education: First Bioblitz in Quito, Ecuador
Authors: Páez-Vacas Mónica , Bustamante Martín R. , Baer Natasha , Oleas Nora H. , Adriana Argoti M. , Sandra Espinoza F , Lozano Zayda , Morales-Espín Belén , Mercedes Gavilanez María , Donoso David A. , Franco-Mena Daniela , Brito Jorge , Miguel Pinto C. , Salazar Laura , Endara María-José , Falconí-López Ana , Bravo-Vera Erick , Sánchez-Lara Enmily , Rivera-Albuja Jordi , Mena Liliana , Muñoz-Lara Kevin , Navas Daniel , Ortiz-Galarza Flor M. , Pamballo Tito , Pineda Doménica , Rivadeneira Jefferson , Segura Sebastián , Valencia Kevin , Vásquez-Barba Pamela , Salazar-Valenzuela David
Published: March 2023

Bioblitz is a citizen global science initiative which aims to find and identify as many species of fauna and flora as possible in a specific area during a short period of time. This activity promotes the engagement of the public to learn about the biodiversity of a particular region, often in urban areas. The objective of this study was to do the first Bioblitz in Quito (Ecuador) to (1) survey the flora and fauna of Quito, specifically in the Guangüiltagua Metropolitan Park; and (2) engage citizens in such activity. This first Bioblitz, held on December 2, 2017, was organized by Universidad Tecnológica Indoamérica and Fundación Zoológica del Ecuador. The event was attended by 15 experts, 21 students, and 29 citizens, including two children under 10 years of age. Standard biological diversity assessment methods were used for amphibians, reptiles, birds, mammals, insects, aquatic macroinvertebrates, and plants. A total of 18 species of birds, two of amphibians, one reptile, 21 terrestrial invertebrates, two macroinvertebrates, one mammal, and 26 plant species were identified. This experience allowed the engagement of citizens to learn about the local biodiversity in their city.
Perspectives of informal street waste pickers in Loja-Ecuador
Authors: Iñiguez-Gallardo Verónica , Romero Mejía Pablo.
Published: March 2023

Waste pickers contribute to country environmental and sustainability goals, and yet they are a marginalised and precarious group that requires further research. Using a case study design of informal waste pickers in Loja-Ecuador, representatives from waste picker associations, recycling warehouses, and public agencies were interviewed about the dynamics of informal recycling in this city. In addition, street level waste pickers were interviewed to understand their difficulties. The data obtained were complemented by participant observation of the recycling work on the street. The results show that in the city of Loja, two types of waste pickers coexist —associated and non-associated—, those who are associated obtain higher profits although the main perceived benefit is to carry out the activity under the authority’s consent. Likewise, it was found that waste recovery is the main income source for most of the families engaged in this activity, however, the income generated varies by gender. Furthermore, the majority of waste pickers are women who, along with children and the elderly, are disadvantaged as compared with their male counterparts in performing this activity. Competition for recyclable material among waste pickers was cited as the main problem. The findings provide the basis for constructing an inclusive urban development process that considers the work of waste pickers within the framework of a popular and solidarity economy.
Storage Systems for Energy Harvesting Applications
Authors: Gordón Carlos , Salazar Fabián , Gallardo Cristina , Cuji Julio
Published: March 2023

Currently, the use of energy from the environment to generate electricity has triggered applications like Energy Harvesting because it is an ecological and autonomous energy that can be used in countless applications, the disadvantage of these systems is the storage system so in this research, a literature review of the use of storage technologies for their implementation in energy Harvesting systems has been carried out. The main objective is to evaluate the performance of the soul-saving systems by making a comparison with existing batteries on the market, with an analysis of the modelling and simulation through Wolfram System Modeler where it allows to understand the behavior of the charging and unchanging processes from the results obtained in energy harvesting systems previously developed by students of the Technical University of Ambato obtaining parameters involved in them to test the Energy Harvesting system with different batteries and thus, achieve greater energy re-collection and storage. These results are very promising because it has been possible to demonstrate by simulation and measurement that the batteries contained in their composition are suitable for Energy Harvesting systems.