bluuebunny/crossref_metadata_2025 huggingface dataset:
Gender Dysphoria in the Pediatric Population: Initial Experience of a Transdisciplinary Group
Authors: Moreno-Bencardino Camila , Zuluaga Laura , Perez Jaime , Cespedes Camila , Forero Catalina , Fernandez Nicolas
Published: December 2021

Introduction Although there is an increasing experience in the management of transgender individuals, this has not been thoroughly explored in children. The need to establish a comprehensive and transdisciplinary management is of critical importance. In order to solve this issue, we want to report the results of a cohort of individuals with gender dysphoria (GD) seen by our transdisciplinary group from a social and clinical and health access perspective.

Methods A 10-year retrospective case series of all patients that had been seen by our transdisciplinary team was reviewed. The main demographic characteristics were described, as well as impact variables in terms of diagnosis and treatment of these individuals. A social description of each individual was described. Frequency, distribution, and central tendency measures were evaluated for data presentation. IBM SPSS Statistics for Windows, version 24.0 (IBM Corp, Armonk, NY) software was used.

Results Four cases of GD were included. Three had male to female dysphoria and one female to male. The median reported age of GD awareness was 6 years old (between 4 and 8 years old), and the median time between GD awareness and the 1st medical evaluation was 7 years for all individuals. The median age at gender role expression was 12 years old (between 10 and 14 years old). All patients had already assumed their experienced gender role before the 1st evaluation by our group. The median age at the 1st evaluation by our group was 13 years old (between 10 and 16 years old); three of the patients were evaluated after initiation of puberty. In the present study, individuals with GD demonstrated having health care access barriers for their transition process. Referral times are high, and individuals with GD are cared after pubertal development, which is related to suboptimal outcomes. The spectrum of GD is broad, and management must be individualized according to expectations.

Conclusion Individuals with GD face multiple access barriers that limit their possibility of being seen by a transdisciplinary team. This reflects in longer waiting times that negatively impact medical management. Gender dysphoria is a wide spectrum, and individuals should be evaluated individually by a transdisciplinary team.
Treatment of Unique Bilateral Distal Fusiform Superior Cerebellar Artery Aneurysms with Mini-Flow Diverter Device Implantation: Case Report
Authors: Hofmann Björn B. , Rubbert Christian , Turowski Bernd , Hänggi Daniel , Muhammad Sajjad
Published: December 2021

Currently, surgical revascularization procedures using intracranial–intracranial (IC-IC) or extracranial–intracranial (EC-IC) bypass and distal clipping or trapping are the valid and rescue treatment modality for extremely rare unilateral distal fusiform superior cerebellar artery (SCA) aneurysms. Yet, in case of bilateral fusiform SCA aneurysms, surgical therapy reaches its limit. Mini-flow diverter devices (FDDs) have only recently become available for treating fusiform aneurysms of such small vessels. We report the unique case of bilateral distal fusiform SCA aneurysms in a 43-year-old man with subarachnoid hemorrhage (Fisher grade IV and World Federation of Neurosurgical Societies [WFNS] grade II) treated with endovascular implantation of bilateral mini-FDDs with excellent outcome and no radiographic signs of infarction. Yet, occlusion of one of the FDDs was found in the follow-up, which again shows the eminent danger of occlusion in case of an implantation of FDDs in such small-caliber vessels, which leaves the discussion about the optimal therapy method open.
Vertebroplasty, Kyphoplasty, and Implant-Based Mechanical Vertebral Augmentation
Authors: Key Brandon M. , Symanski John , Scheidt Matthew J. , Tutton Sean M.
Published: December 2021

Vertebral compression fractures are a global public health issue with a quantifiable negative impact on patient morbidity and mortality. The contemporary approach to the treatment of osteoporotic fragility fractures has moved beyond first-line nonsurgical management. An improved understanding of biomechanical forces, consequential morbidity and mortality, and the drive to reduce opioid use has resulted in multidisciplinary treatment algorithms and significant advances in augmentation techniques. This review will inform musculoskeletal radiologists, interventionalists, and minimally invasive spine surgeons on the proper work-up of patients, imaging features differentiating benign and malignant pathologic fractures, high-risk fracture morphologies, and new mechanical augmentation device options, and it describes the appropriate selection of devices, complications, outcomes, and future trends.
Tumor fibroblástico inguinal superficial positivo para CD34. Reporte de un caso y revisión de la literatura
Authors: Linares R Francisco , Messa B Oscar , Cuello G Sebastián , Martín V Helbert
Published: December 2021

El tumor fibroblástico superficial de tejidos blandos positivo para antígeno CD34 (CD34) es un tumor raro, de baja frecuencia, que se caracteriza histológicamente por un marcado pleomorfismo, baja actividad mitótica, e inmunoreactividad difusa para CD34. Puede tener un comportamiento similar al de un tumor mesenquimal de malignidad intermedia. Existen sólo 52 casos publicados en la literatura. Se presenta el caso de una paciente de 31 años con una masa en tejidos blandos en región inguinal izquierda, de crecimiento progresivo, de varios meses de evolución dolorosa. La masa fue biopsiada y, con la sospecha de un tumor fibroblástico superficial positivo para CD34, fue posteriormente tratada con una resección ampliada de la lesión y con cobertura del defecto en la piel con un colgajo local de avance de V-Y, con una evolución satisfactoria en su seguimiento postquirúrgico. El reporte de patología confirmó la sospecha diagnóstica de un tumor con reactividad fuerte para CD34, con proteína P53 en 60% a 70%, antígeno Ki67 menor al 15%, sin pérdida de proteína nuclear INI-1, y negatividad para CD31, CD163, AE1AE3, CAM5.2, EMA, CD30, receptores de progestágenos, proteína S100, y desmina, con bordes negativos.

Nivel de evidencia IV.
Radiofrequency Ablation of Spine Metastases: A Clinical and Technical Approach
Authors: Yevich Steven , Chen Stephen , Metwalli Zeyad , Kuban Joshua , Lee Stephen , Habibollahi Peiman , McCarthy Colin J. , Irwin David , Huang Steven , Sheth Rahul A.
Published: December 2021

Percutaneous radiofrequency ablation (RFA) is an integral component of the multidisciplinary treatment algorithm for both local tumor control and palliation of painful spine metastases. This minimally invasive therapy complements additional treatment strategies, such as pain medications, systemic chemotherapy, surgical resection, and radiotherapy. The location and size of the metastatic lesion dictate preprocedure planning and the technical approach. For example, ablation of lesions along the spinal canal, within the posterior vertebral elements, or with paraspinal soft tissue extension are associated with a higher risk of injury to adjacent spinal nerves. Additional interventions may be indicated in conjunction with RFA. For example, ablation of vertebral body lesions can precipitate new, or exacerbate existing, pathologic vertebral compression fractures that can be prevented with vertebral augmentation. This article reviews the indications, clinical work-up, and technical approach for RFA of spine metastases.
Interpretación medicolegal para el abordaje de individuos con desórdenes del desarrollo sexual en Colombia
Authors: Fernandez Nicolas , Zuluaga Laura , Perez Maria Fernanda , Perez Jaime , Cespedes Camila , Forero Catalina , Orjuela Camilo , Suarez Fernando
Published: December 2021

Objetivo Los desórdenes del desarrollo sexual (DDSs) son un grupo de condiciones médicas cuyo manejo implica un enfoque transdisciplinario. En la legislación colombiana, no existe una regulación específica en materia de intervenciones médicas en individuos con DDSs. La Corte Constitucional Colombiana se ha encargado de proferir sentencias, en las cuales se han establecido unos lineamientos y parámetros para el manejo jurídico de los casos de ambigüedad genital.

Teniendo en cuenta lo anterior, nos proponemos en este artículo exponer y analizar, desde la visión de un grupo transdisciplinario, las sentencias más relevantes que han sido proferidas por la Corte Constitucional Colombiana.

Métodos Se realizó una revisión narrativa en las bases de datos de la Corte Constitucional y de la literatura legal. Se recopilaron todas las sentencias disponibles, y se evaluaron lo casos clínicos identificados por el grupo transdisciplinario de DDSs del Hospital Universitario San Ignacio. Finalmente, los autores generaron por consenso un texto de discusión, como guía para los lectores, luego de analizar cada una de las sentencias y los casos presentados.

Resultados Se identificaron 9 sentencias y los antecedentes que llevaron a la elaboración de cada una de ellas. Los nueve casos presentados contienen conceptos importantes para la articulación por parte del grupo transdisciplinario, tales como, autonomía, consentimiento sustituto y asistido, e indicación médica del tratamiento. Se excluyeron las sentencias T-692/99 y la T-918/2012, dado que daban información duplicada con referencia a sentencias incluidas en este documento.

Conclusión La Corte Constitucional Colombiana ha proferido sentencias en las cuales no se ha contado con la participación de grupos de expertos. La terminología usada no describe apropiadamente el lenguaje técnico que se aplica al manejo de nuestros pacientes. Para el abordaje de individuos con DDSs, resulta muy importante conocer la relevancia de las sentencias basadas en un análisis individual de cada caso.
Evaluation of Hindlimb Deformity and Posture in Dogs with Grade 2 Medial Patellar Luxation during Awake Computed Tomography Imaging while Standing
Authors: Tomo Yuma , Edamura Kazuya , Yamazaki Atsushi , Tanegashima Koji , Seki Mamiko , Asano Kazushi , Tinga Selena , Hayashi Kei
Published: December 2021

Objective The aim of this study was to determine the degree of bone deformities and hindlimb postural abnormalities in a standing position in awake Toy poodles with and without grade 2 medial patellar luxation (MPL) using high speed 320-row computed tomography (CT).

Methods The limbs with grade 2 MPL (MPL-G2 group) and without any orthopaedic disorders (control group) were imaged in a standing position, without sedation or anaesthesia, using CT. In MPL-G2 group, images were obtained when the patella was luxated (G2-L group) and reduced (non-luxation, G2-NL group). Bone morphologies of the femur and tibia were quantified three-dimensionally. Hindlimb standing posture was evaluated by measuring femoral rotation and abduction angles, tibial rotation angle, metatarsal rotation angle, foot rotation angle, angle between the femoral anatomical axis and the mechanical axis of hindlimb and stifle joint line convergence angle.

Results There were no significant differences in bone morphologic parameters between the MPL-G2 group (5 limbs) and the control group (6 limbs). In the G2-NL group, there were no significant hindlimb postural abnormalities. In contrast, in the G2-L group, significant hindlimb postural abnormalities including external rotation of femur, internal rotation of tibia and foot, external rotation of tarsal joint, large stifle joint convergence angle, genu varum and toe-in standing were observed.

Conclusion Dogs with grade 2 MPL have no bone deformities but show abnormal standing posture when the patella is luxated.
Anomalous Hall effect in spatially inhomogeneous SrRuO3 films
Authors: Zhu Mo , Cui Zhangzhang , Li Weiwei , Shan Zheling , Wang Jianlin , Huang Haoliang , Fu Zhengping , Lu Yalin
Published: December 2021

The Topological Hall Effect (THE) has been considered a hallmark of magnetic skyrmions in SrRuO3 single films and heterostructures. Alternative interpretations suggest that the THE-like anomalies could also originate from multi-channel anomalous Hall effects (AHEs) induced by structural inhomogeneity. Here, we reveal another type of THE-like anomaly in SrRuO3 films that was rarely reported previously. By scanning minor loops of the Hall resistivity of ultrathin SrRuO3 films, we demonstrate that the increased saturation resistivity and reversed polarity with decreasing a scanning field cannot be explained by THE, while it shows consistence with spatially inhomogeneous AHE. Our research provides a simple but effective way to quantitatively distinguish between THE and inhomogeneous AHE in those magnetic systems even beyond SrRuO3.
Toward “hereditary epidemiology”: A temporal Boltzmann approach to COVID-19 fatality trends
Authors: Ukaj Niketa , Scheiner Stefan , Hellmich Christian
Published: December 2021

Countless research contributions reflect two major concepts for modeling the spread of the COVID-19 pandemic: (i) ordinary differential equations for population compartments, such as infected or deceased persons (these approaches often exhibit limited predictive capabilities); and (ii) rules applied to digitally realized agents in the populations (these approaches often lack reliable input data and may become computationally overly expensive). As a remedy, we here introduce and discuss convolutional integrodifferential equations adapted from Boltzmann's hereditary mechanics, so as to predict COVID-19 fatality trends from the evolutions of newly infected persons. Replacing the classical statistical reasoning by deliberations arising from the notion of “virus loads” and the corresponding compliance of the infected population to these loads, model errors with respect to data recorded in 102 countries, territories, or US states can be drastically reduced, namely, up to 98% when compared to the traditional kinetics equation of Kermack and McKendrick. The coefficients of determination between model predictions and recorded data range from 94% to 100%, a precision hitherto unachieved in equation-based epidemic modeling.
Role of antioxidative defense system in amelioration of cadmium-induced phytotoxic effects in germinating seeds of maize (
Authors: Abbas Aamer , Ahmad Muhammad Sajid Aqeel , Ashraf Muhammad , Ali Qasim , Alvi Ambreen Khadija
Published: December 2021

Context Anthropogenic activities are increasing Cd concentration in soil and environment that limits seed germination capacity and causes poor seedling establishment. Aims The effect of different Cd concentrations on seed germination and seedling growth of two maize cultivars (C-20 and EV-1098) was tested in this study. Methods Maize seeds were sown in Petri dishes lined with double filter paper. The seedlings were grown in a growth chamber, applied with different Cd concentrations (0, 2, 4, 6, 8 and 10 μM), and harvested 12 days after germination. Key results Seeds applied with higher levels of Cd showed a significant decrease in seed germination percentage (GP), seed emergence index (EI) and germination energy (GE). A significant delay in seed germination was observed at the highest Cd treatment in terms of increased mean emergence time (MET), days to 50% germination (T 50) and coefficient of uniformity of emergence (CUE). A marked decline in leaf K, Ca, Na, and P was observed, whereas root K, Ca and P increased with an increase in external Cd concentration. The roots and leaves of maize C-20 showed greater activities of superoxide dismutase (SOD) than did those of EV-1098. In contrast, peroxidase (POD) activity was reasonably high in roots and leaves, whereas catalase (CAT) was high only in roots of EV-1098. Non-enzymatic antioxidants such as phenolics and ascorbicacid (AsA) also significantly increased, accompanied with substantially lowermalondialdehyde (MDA) contents in the roots and leaves of EV-1098 than of C-20. Conclusions The differential modulation of the activities of enzymatic and non-enzymaticanti-oxidative defense system in roots and leaves played a critical role intolerance of both cultivars to Cd stress. Implications The findings of this study are helpful in improving seed germination capacity and seedling growth of maize in Cd contaminated soils.
Comparing acoustic survey data for European bats: do walked transects or automated fixed-point surveys provide more robust data?
Authors: Perks Samantha J. , Goodenough Anne E.
Published: December 2021

Abstract Context Monitoring schemes provide vital data on the distribution and population dynamics of species. This information can be used to inform conservation management and, especially for legally protected species, ensure legislative compliance in development contexts. For bats, acoustic activity surveys are widely used and often involve (1) deployment of automated fixed-point detectors or (2) using bat detectors on walked or driven transects. Transect surveys are typically performed for 2 h, commencing approximately at sunset; automated fixed-point surveys record continually between sunset and sunrise, often over multiple consecutive nights. Aims Despite both walked transects and fixed-point surveys being common methods used to survey bat activity in many parts of the world, often just one technique is used per site. We test the similarity of these two survey methods by comparing acoustic data encompassing 12 species of European bat to determine whether data from different surveys are directly comparable. Methods In this study, we use acoustic data covering 2349 survey hours over a 3-year period to investigate the relative effectiveness of walked activity transects and automated fixed-point methods for 12 species of European bats. Key results A greater number of bat species were recorded via the fixed-point method. Three species, namely, greater horseshoe (Rhinolophus ferrumequinum), lesser horseshoe (Rhinolophus hipposideros) and Daubenton’s (Myotis daubentonii), were recorded only by using automated detectors, possibly because the survey window encompassed the entire night rather than the period immediately after sunset. However, activity transects recorded a significantly higher mean species richness per hour than fixed-point surveys. When both methods were used at the same sites on the same nights, providing paired data for direct comparison, detection of brown long-eared (Plecotus auratus) and soprano pipistrelle (Pipistrellus pygmaeus) bat activity was significantly higher for transect surveys. Conclusions and implications This study demonstrated important differences in the data resulting from different bat survey methods and highlighted the potential for combining acoustic survey types to obtain rigorous and reliable monitoring data for bat populations.
No mammal recovery from feral cat experimental exclusion trials in Kakadu National Park
Authors: Stokeld Danielle , Fisher Alaric , Gentles Tim , Hill Brydie M. , Woinarski John C. Z. , Gillespie Graeme R.
Published: December 2021

Abstract Context Small and medium-sized native mammals have declined precipitously across northern Australia. Feral cats have been implicated in causing declines and ongoing suppression of populations. Aims The aim of the present study was to evaluate the response of small and medium-sized native mammal populations when cat predation was removed. Methods A field experiment was conducted in a tropical savanna environment of northern Australia. Three experimental treatments were applied to six plots to compare and contrast responses of native mammals to predator exclusion and the additive effects of frequent fire. Plots were monitored regularly between 2013 and 2017. Key results After 4 years of monitoring, no significant difference in capture rates of native mammals was detected between cat-accessible plots and those where they were excluded. Conclusions There was no evidence of population recovery of native mammals in response to predator exclusion. There was some evidence that frequent burning, independent of cat exclusion, adversely affects native mammal diversity. Implications Although predation by feral cats is a major threat to small and medium-sized native mammals, disturbance from fire, and grazing by introduced herbivores, have been shown to significantly impede native mammal population recovery in tropical savanna ecosystems. Management programs that solely focus on suppressing feral cat populations may be inadequate in ameliorating ongoing mammal declines in landscapes with other significant disturbance regimes.
Reducing opinion polarization: Effects of exposure to similar people with differing political views
Authors: Balietti Stefano , Getoor Lise , Goldstein Daniel G. , Watts Duncan J.
Published: December 2021

Significance

Informal political discussions with peers can increase trust in democracy and improve understanding of self and others. However, these benefits do not often materialize because people tend to shy away from political discussions and because friendship networks rarely expose highly divergent political views. In a large-scale experiment, we overcome these limitations by matching participants to peers selected for sharing common interests and demographics and exposing them to a personal message about a divisive political topic: wealth redistribution. As a result, support for redistributive policies increased and polarization decreased. Furthermore, feeling close to a peer greatly increased the assimilation of a political message. Our results suggest that incidental similarities may cold-start cross-cutting political arguments and increase consensus on divisive topics.
Strong-field atomic physics meets 229Th nuclear physics
Authors: Wang Wu , Zhang Hanxu , Wang Xu
Published: December 2021

We show how two apparently unrelated research areas, namely, strong-field atomic physics and 229Th nuclear physics, are connected. The connection is possible due to the existence of a very low-lying excited state of the 229Th nucleus, which is only about 8 eV above the nuclear ground state. The connection is physically achieved through an electron recollision process, which is the core process of strong-field atomic physics. The laser-driven recolliding electron is able to excite the nucleus, and a simple model is presented to explain this recollision-induced nuclear excitation process. The connection of these two research areas provides novel opportunities for each area and intriguing possibilities from the direct three-partite interplay between atomic physics, nuclear physics, and laser physics.
Temperature-dependent ion chemistry in nanosecond discharge plasma-assisted CH4 oxidation
Authors: Sun Jintao , Chen Qi , Zhao Baoming , Guo Caohui , Liu Jianyu , Zhang Mingming , Li Decai
Published: December 2021

Ion chemistry with temperature evolution in weakly ionized plasma is important in plasma-assisted combustion and plasma-assisted catalysis, fuel reforming, and material synthesis due to its contribution to plasma generation and state transition. In this study, the kinetic roles of ionic reactions in nanosecond discharge (NSD) plasma-assisted temperature-dependent decomposition and oxidation of methane are investigated by integrated studies of experimental measurements and mathematical simulations. A detailed plasma chemistry mechanism governing the decomposition and oxidation processes in a He/CH4/O2 combustible mixture is proposed and studied by including a set of electron impact reactions, reactions involving excited species, and ionic reactions. A zero-dimensional model incorporating the plasma kinetics solver ZDPlasKin and the combustion chemical kinetics solver CHEMKIN is used to calculate the time and temperature evolution of the ion density. Uncertainty analysis of ionic reactions on key species generation is conducted by using different referenced data, and insignificant sensitivity is found. The numerical model is consistent with experimental data for methane consumption and generation of major species including CO, CO2, and H2. By modeling the temporal evolution of key ions, it is observed that O2
+ presents the largest concentration in the discharge stage, followed by CH4
+, CH3
+, and CH2
+, which is in accordance with the traditional ion chemistry in hydrocarbon flames and agrees well with molecular-beam mass spectrometer investigations. The path flux shows that the concentrations of key species, including electrons, O, OH, H, O(1D), O2(a1Δg), O2
+, CH3
+, and CH4
+, change within 1–2 orders of magnitude and that the transition from a homogeneous state to a contracted/constricted state does not occur. The path flux and sensitivity analysis reveal the significant roles of cations in the stimulation of active radical generation, including CH, O, OH, and O(1D), thus accelerating methane oxidation. This work provides a deep insight into the ion chemistry of temperature-dependent plasma-assisted CH4 oxidation.
First-principles study on the heterostructure of twisted graphene/hexagonal boron nitride/graphene sandwich structure
Authors: Chen Yiheng , Guo Wen-Ti , Chen Zi-Si , Wang Suyun , Zhang Jian-Min
Published: December 2021

In recent years, the discovery of ‘magic angle’ graphene has given new inspiration to the formation of heterojunctions. Similarly, the use of hexagonal boron nitride, known as white graphene, as a substrate for graphene devices has more aroused great interest in the graphene/hexagonal boron nitride heterostructure system. Based on the first principles method of density functional theory, the band structure, density of states, Mulliken population, and differential charge density of a tightly packed model of twisted graphene/hexagonal boron nitride/graphene sandwich structure have been studied. Through the establishment of heterostructure models twisted bilayer-graphene inserting hBN with different twisted angles, it was found that the band gap, Mulliken population, and charge density, exhibited specific evolution regulars with the rotation angle of the upper graphene, showing novel electronic properties and realizing metal–insulator phase transition. We find that the particular value of the twist angle at which the metal–insulator phase transition occurs and propose a rotational regulation mechanism with angular periodicity. Our results have guiding significance for the practical application of heterojunction electronic devices.
A multi-scale kernel-based network with improved attention mechanism for rotating machinery fault diagnosis under noisy environments
Authors: Weng Chaoyang , Lu Baochun , Gu Qian
Published: December 2021

Considering that the vibration signals are easily contaminated by strong and highly nonstationary noise, extracting more sensitive and effective features from the noised vibration signals is still a great challenge for intelligent fault diagnosis of rotating machinery. This paper proposes a multi-scale kernel-based network with an improved attention mechanism (IA-MKNet) to overcome this challenge. In the proposed method, an improved attention mechanism (IAM) for multi-scale convolution is firstly developed to adaptively extract the meaningful fault features and automatically suppress noise. Then, due to the inherent multiple time characteristics of vibration signals, an adaptive multi-scale kernel-based residual block with IAM is designed to capture fault features in multi-time scales of vibration signals. Finally, a combination strategy based on an adaptive ensemble learner is proposed to increase the diversity of features by fusing the outputs of multiple IA-MKNets, which further improves diagnostics accuracy and stability. The experimental results, verified by two bearing data sets with noise interference, confirm that the proposed method improves the fault diagnosis accuracy of rotating machinery under noisy environments, whose performance is superior to the other five benchmark methods.
Optical flow tracking velocimetry of near-field explosions
Authors: Higham J E , Isaac O S , Rigby S E
Published: December 2021

To better understand the complex dynamics and physics associated with the rapid expansion of the detonation product fireball following an explosion, it is imperative to have a full description of its associated velocity field. Typical experimental techniques rely on simple single-point measurements captured from pressure transducers or Hopkinson pressure bars. In this technical design note, we aim to improve the current state-of-the-art by introducing a means to determine full velocity fields from high-speed video using optical flow tracking velocimetry. We demonstrate the significance of this method from our results by comparing velocity fields derived from high-speed video and a validated numerical model of the same case. A wider use of this technique will allow researchers to elucidate spatial and temporal features of explosive detonations, which could not be obtained thus far using single-point measurements.
Melting at Mg/Al interface in Mg–Al–Mg nanolayer by molecular dynamics simulations
Authors: Lv Xue-Qi , Li Xiong-Ying
Published: December 2021

The melting at the magnesium/aluminum (Mg/Al) interface is an essential step during the fabrications of Mg–Al structural materials and biomaterials. We carried out molecular dynamics simulations on the melting at the Mg/Al interface in a Mg–Al–Mg nanolayer via analyzing the changes of average atomic potential energy, Lindemann index, heat capacity, atomic density distribution and radial distribution function with temperature. The melting temperatures (

T

m

) of the nanolayer and the slabs near the interface are significantly sensitive to the heating rate (

v

h

) over the range of

v

h

 ≤ 4.0 K ps−1. The distance (

d

) range in which the interface affects the melting of the slabs is predicted to be (−98.2, 89.9) Å at

v

h

→
0
,

if the interface is put at

d

 = 0 and Mg (Al) is located at the left (right) side of the interface. The

T

m

of the Mg (Al) slab just near the interface (e.g.

d
=
4.0

Å) is predicted to be 926.8 K (926.6 K) at

v

h

→
0
,

with 36.9 K (37.1 K) below 963.7 K for the nanolayer. These results highlight the importance of regional research on the melting at an interface in the nanolayers consisting of two different metals.
Critical current improvement and resistance evaluation of superconducting joint between Bi2223 tapes
Authors: Takeda Y , Kobayashi K , Uchida A , Kitaguchi H , Nishijima G , Yanagisawa Y , Nakashima T , Yamade S , Kobayashi S , Kato T , Nakamura S , Motoki T , Shimoyama J
Published: December 2021

We improved the critical current (I
c) of the superconducting joint between the Bi2223 tapes by introducing the two-step sintering process. The in-field transport I
c of ∼300 A at 4.2 K and 1 T under a 10−9 Ω criterion was successfully demonstrated. The I
c improvement can probably be attributed to the enhancement of the intergrain critical current density for a Bi2223 intermediate layer. Ultra-low in-field joint resistance below 10−14 Ω at 4.2 K and 1 T was also demonstrated using current decay measurement. To the best of our knowledge, this study is the first to demonstrate a practical level of in-field transport I
c and ultra-low in-field joint resistance for the superconducting joint between Bi2223 tapes. We believe that this superconducting joint technology will facilitate development of persistent current mode Bi2223 superconducting magnets.
Quantum versus classical regime in circuit quantum acoustodynamics
Authors: Zeng Gang-hui , Zhang Yang , Bolgar Aleksey N , He Dong , Li Bin , Ruan Xin-hui , Zhou Lan , Kuang Le-Mang , Astafiev Oleg V , Liu Yu-xi , Peng Z H
Published: December 2021

We experimentally study a circuit quantum acoustodynamics system with a superconducting artificial atom coupled to both a two-dimensional surface acoustic wave resonator and a one-dimensional microwave transmission line. The strong coupling between the artificial atom and the acoustic wave resonator is confirmed by the observation of the vacuum Rabi splitting at the base temperature of dilution refrigerator. We show that the propagation of microwave photons in the microwave transmission line can be controlled by a few phonons in the acoustic wave resonator. Furthermore, we demonstrate the temperature effect on the measurements of the Rabi splitting and temperature induced transitions from high excited dressed states. We find that the spectrum structure of two-peak for the Rabi splitting could become into those of several peaks under some special experimental conditions, and gradually disappears with the increase of the environmental temperature T. The continuous quantum-to-classical crossover is observed around the crossover temperature T
c, which is determined via the thermal fluctuation energy k
B
T and the characteristic energy level spacing of the coupled system. Experimental results agree well with the theoretical simulations via the master equation of the coupled system at different effective temperatures.
Topological signatures in nodal semimetals through neutron scattering
Authors: Nguyen Thanh , Tsurimaki Yoichiro , Pablo-Pedro Ricardo , Bednik Grigory , Liu Tongtong , Apte Anuj , Andrejevic Nina , Li Mingda
Published: December 2021

Topological nodal semimetals are known to host a variety of fascinating electronic properties due to the topological protection of the band-touching nodes. Neutron scattering, despite its power in probing elementary excitations, has not been routinely applied to topological semimetals, mainly due to the lack of an explicit connection between the neutron response and the signature of topology. In this work, we theoretically investigate the role that neutron scattering can play to unveil the topological nodal features: a large magnetic neutron response with spectral non-analyticity can be generated solely from the nodal bands. A new formula for the dynamical structure factor for generic topological nodal metals is derived. For Weyl semimetals, we show that the locations of Weyl nodes, the Fermi velocities and the signature of chiral anomaly can all leave hallmark neutron spectral responses. Our work offers a neutron-based avenue toward probing bulk topological materials.
Density- and elongation speed-dependent error correction in RNA polymerization
Authors: Zuo Xinzhe , Chou Tom
Published: December 2021

Backtracking of RNA polymerase (RNAP) is an important pausing mechanism during DNA transcription that is part of the error correction process that enhances transcription fidelity. We model the backtracking mechanism of RNAP, which usually happens when the polymerase tries to incorporate a noncognate or ‘mismatched’ nucleotide triphosphate. Previous models have made simplifying assumptions such as neglecting the trailing polymerase behind the backtracking polymerase or assuming that the trailing polymerase is stationary. We derive exact analytic solutions of a stochastic model that includes locally interacting RNAPs by explicitly showing how a trailing RNAP influences the probability that an error is corrected or incorporated by the leading backtracking RNAP. We also provide two related methods for computing the mean times for error correction and incorporation given an initial local RNAP configuration. Using these results, we propose an effective interacting-RNAP lattice that can be readily simulated.
Push or pull: how cytoskeletal crosstalk facilitates nuclear movement through 3D environments
Authors: Marks Pragati C , Petrie Ryan J
Published: December 2021

As cells move from two-dimensional surfaces into complex 3D environments, the nucleus becomes a barrier to movement due to its size and rigidity. Therefore, moving the nucleus is a key step in 3D cell migration. In this review, we discuss how coordination between cytoskeletal and nucleoskeletal networks is required to pull the nucleus forward through complex 3D spaces. We summarize recent migration models which utilize unique molecular crosstalk to drive nuclear migration through different 3D environments. In addition, we speculate about the role of proteins that indirectly crosslink cytoskeletal networks and the role of 3D focal adhesions and how these protein complexes may drive 3D nuclear migration.
Integrating neural and ocular attention reorienting signals in virtual reality
Authors: Lapborisuth Pawan , Koorathota Sharath , Wang Qi , Sajda Paul
Published: December 2021

Objective. Reorienting is central to how humans direct attention to different stimuli in their environment. Previous studies typically employ well-controlled paradigms with limited eye and head movements to study the neural and physiological processes underlying attention reorienting. Here, we aim to better understand the relationship between gaze and attention reorienting using a naturalistic virtual reality (VR)-based target detection paradigm. Approach. Subjects were navigated through a city and instructed to count the number of targets that appeared on the street. Subjects performed the task in a fixed condition with no head movement and in a free condition where head movements were allowed. Electroencephalography (EEG), gaze and pupil data were collected. To investigate how neural and physiological reorienting signals are distributed across different gaze events, we used hierarchical discriminant component analysis (HDCA) to identify EEG and pupil-based discriminating components. Mixed-effects general linear models (GLM) were used to determine the correlation between these discriminating components and the different gaze events time. HDCA was also used to combine EEG, pupil and dwell time signals to classify reorienting events. Main results. In both EEG and pupil, dwell time contributes most significantly to the reorienting signals. However, when dwell times were orthogonalized against other gaze events, the distributions of the reorienting signals were different across the two modalities, with EEG reorienting signals leading that of the pupil reorienting signals. We also found that the hybrid classifier that integrates EEG, pupil and dwell time features detects the reorienting signals in both the fixed (AUC = 0.79) and the free (AUC = 0.77) condition. Significance. We show that the neural and ocular reorienting signals are distributed differently across gaze events when a subject is immersed in VR, but nevertheless can be captured and integrated to classify target vs. distractor objects to which the human subject orients.
A computational approach for generating continuous estimates of motor unit discharge rates and visualizing population discharge characteristics
Authors: Beauchamp James A , Khurram Obaid U , Dewald Julius P A , Heckman CJ , Pearcey Gregory E P
Published: December 2021

Objective. Successive improvements in high density surface electromyography and decomposition techniques have facilitated an increasing yield in decomposed motor unit (MU) spike times. Though these advancements enhance the generalizability of findings and promote the application of MU discharge characteristics to inform the neural control of motor output, limitations remain. Specifically, (1) common approaches for generating smooth estimates of MU discharge rates introduce artifacts in quantification, which may bias findings, and (2) discharge characteristics of large MU populations are often difficult to visualize. Approach. In the present study, we propose support vector regression (SVR) as an improved approach for generating smooth continuous estimates of discharge rate and compare the fit characteristics of SVR to traditionally used methods, including Hanning window filtering and polynomial regression. Furthermore, we introduce ensembles as a method to visualize the discharge characteristics of large MU populations. We define ensembles as the average discharge profile of a subpopulation of MUs, composed of a time normalized ensemble average of all units within this subpopulation. Analysis was conducted with MUs decomposed from the tibialis anterior (N = 2128), medial gastrocnemius (N = 2673), and soleus (N = 1190) during isometric plantarflexion and dorsiflexion contractions. Main result. Compared to traditional approaches, we found SVR to alleviate commonly observed inaccuracies and produce significantly less absolute fit error in the initial phase of MU discharge and throughout the entire duration of discharge. Additionally, we found the visualization of MU populations as ensembles to intuitively represent population discharge characteristics with appropriate accuracy for visualization. Significance. The results and methods outlined here provide an improved method for generating estimates of MU discharge rate with SVR and present a unique approach to visualizing MU populations with ensembles. In combination, the use of SVR and generation of ensembles represent an efficient method for rendering population discharge characteristics.
Canonical EEG microstates transitions reflect switching among BOLD resting state networks and predict fMRI signal
Authors: Al Zoubi Obada , Mayeli Ahmad , Misaki Masaya , Tsuchiyagaito Aki , Zotev Vadim , Refai Hazem , Paulus Martin , Bodurka Jerzy
Published: December 2021

Objective. Electroencephalography (EEG) microstates (MSs), which reflect a large topographical representation of coherent electrophysiological brain activity, are widely adopted to study cognitive processes mechanisms and aberrant alterations in brain disorders. MS topographies are quasi-stable lasting between 60–120 ms. Some evidence suggests that MS are the electrophysiological signature of resting-state networks (RSNs). However, the spatial and functional interpretation of MS and their association with functional magnetic resonance imaging (fMRI) remains unclear. Approach. In a cohort of healthy subjects (n = 52), we conducted several statistical and machine learning (ML) approaches analyses on the association among MS spatio-temporal dynamics and the blood-oxygenation-level dependent (BOLD) simultaneous EEG-fMRI data using statistical and ML approaches. Main results. Our results using a generalized linear model showed that MS transitions were largely and negatively associated with BOLD signals in the somatomotor, visual, dorsal attention, and ventral attention fMRI networks with limited association within the default mode network. Additionally, a novel recurrent neural network (RNN) confirmed the association between MS transitioning and fMRI signal while revealing that MS dynamics can model BOLD signals and vice versa. Significance. Results suggest that MS transitions may represent the deactivation of fMRI RSNs and provide evidence that both modalities measure common aspects of undergoing brain neuronal activities. These results may help to better understand the electrophysiological interpretation of MS.
Transcranial photoacoustic characterization of neurovascular physiology during early-stage photothrombotic stroke in neonatal piglets in vivo
Authors: Kang Jeeun , Liu Xiuyun , Cao Suyi , Zeiler Steven R , Graham Ernest M , Boctor Emad M , Koehler Raymond C
Published: December 2021

Objective: Perinatal ischemic stroke is estimated to occur in 1/2300–1/5000 live births, but early differential diagnosis from global hypoxia-ischemia is often difficult. In this study, we tested the ability of a hand-held transcranial photoacoustic (PA) imaging probe to non-invasively detect a focal photothrombotic stroke (PTS) within 2 h of stroke onset in a gyrencephalic piglet brain. Approach: About 17 stroke lesions of approximately 1 cm2 area were introduced randomly in anterior or posterior cortex via the light/dye PTS technique in anesthetized neonatal piglets (n = 11). The contralateral non-ischemic region served as control tissue for discrimination contrast for the PA hemoglobin metrics: oxygen saturation, total hemoglobin (tHb), and individual quantities of oxygenated and deoxygenated hemoglobin (HbO2 and HbR). Main results: The PA-derived tissue oxygen saturation at 2 h yielded a significant separation between control and affected regions-of-interest (p < 0.0001), which were well matched with 24 h post-stroke cerebral infarction confirmed in the triphenyltetrazolium chloride-stained image. The quantity of HbO2 also displayed a significant contrast (p = 0.021), whereas tHb and HbR did not. The analysis on receiver operating characteristic curves and multivariate data analysis also agreed with the results above. Significance: This study shows that a hand-held transcranial PA neuroimaging device can detect a regional thrombotic stroke in the cerebral cortex of a neonatal piglet. In particular, we conclude that the oxygen saturation metric can be used alone to identify regional stroke lesions. The lack of change in tHb may be related to arbitrary hand-held imaging configuration and/or entrapment of red blood cells within the thrombotic stroke.
Performance improvement of Compton imaging of astatine-211 by optimising coincidence time windows
Authors: Nagao Y. , Yamaguchi M. , Watanabe S. , Ishioka N.S. , Kawachi N. , Watabe H.
Published: December 2021

Astatine-211 is one of the promising radioisotopes for targeted alpha therapy. Optimising treatment strategies as well as determining the suitability of a given agent for a particular patient requires to image the time-dependent distribution of the targeted radiotherapeutic agent both in tumours and in normal tissues. Since the biodistribution of astatine is different from that of iodine, imaging astatine-211 directly is essential. In the previous study of astatine-211 Compton imaging, random coincidence events due to polonium K-shell X-rays were dominant and seemed to cause saturation of counts. Thus optimisation of the coincidence time windows is important to reduce random coincidence events. In this study, we have optimised the coincidence time windows of a Compton camera and improved the sensitivity, noise and spatial resolution of astatine-211 imaging.
Blood compatibility evaluations of two-dimensional Ti3C2T
x
nanosheets
Authors: Yu Hongbo , Wan Yi , Zhang Guiyin , Huang Xiuhong , Lin Lichen , Zhou Changren , Jiao Yanpeng , Li Hong
Published: December 2021

Two-dimensional nanomaterial Ti3C2T
x
is a novel biomaterial used for medical apparatus. For its application, biosafety serves as a prerequisite for their use in vivo. So far, no research has systematically reported how Ti3C2T
x
interacts with various components in the blood. In this work, we evaluated the hemocompatibility of Ti3C2T
x
nanosheets which we prepared by HF etching. Effects of the concentration and size of Ti3C2T
x
on the morphology and hemolysis rate of human red blood cells (RBCs), the structure and conformation of plasma proteins, the complement activation, as well as in vitro blood coagulation were studied. In general, Ti3C2T
x
takes on good blood compatibility, but in the case of high concentration (>30 μg ml−1) and ‘small size’ (about 100 nm), it led to the rupture of RBCs membrane and a higher rate of hemolysis. Meanwhile, platelets and complement were inclined to be activated with the increased concentration, accompanying the changed configuration of plasma proteins dependent on concentration. Surprisingly, the presence of Ti3C2T
x
did not significantly disrupt the coagulation. In vitro cell culture, the results prove that when the Ti3C2T
x
concentration is as high as 60 μg ml−1 and still has good biological safety. By establishing a fuzzy mathematical model, it was proved that the hemocompatibility of Ti3C2T
x
is more concentration-dependent than size-dependent, and the hemolysis rate is the most sensitive to the size and concentration of the Ti3C2T
x
. These findings provide insight into the potential use of Ti3C2T
x
as biofriendly nanocontainers for biomaterials in vivo.