bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal resistance in superconducting flip-chip assemblies
Authors: Hätinen J. , Mykkänen E. , Viisanen K. , Ronzani A. , Kemppinen A. , Lehtisyrjä L. , Lehtinen J. S. , Prunnila M.
Published: October 2023

Cryogenic microsystems that utilize different 3D integration techniques are being actively developed, e.g., for the needs of quantum technologies. 3D integration can introduce opportunities and challenges to the thermal management of low temperature devices. In this work, we investigate sub-1 K inter-chip thermal resistance of a flip-chip bonded assembly, where two silicon chips are interconnected by compression bonding via indium bumps. The total thermal contact area between the chips is 0.306 mm2, and we find that the temperature dependence of the inter-chip thermal resistance follows the power law of αT−3, with α=7.7–15.4 K4μm2/nW. The T−3 relation indicates phononic interfacial thermal resistance, which is supported by the vanishing contribution of the electrons to the thermal conduction, due to the superconducting interconnections. Such a thermal resistance value can introduce a thermalization bottleneck in particular at cryogenic temperatures. This can be detrimental for some applications, yet it can also be harnessed. We provide an example of both cases by estimating the parasitic overheating of a cryogenic flip-chip assembly operated under various heat loads as well as simulate the performance of solid-state junction microrefrigerators utilizing the observed thermal isolation.
Aeroacoustic investigation of transonic flow behavior in M219 deep cavity with passive flow control configurations
Authors: Şeker A. E. , Zafer B. , Gonzalez-Martino I. , Yücetepe M.
Published: October 2023

This study aims to investigate the effect of front and aft wall modifications and their combinations on the sound pressure level response of the deep configuration of the M219 cavity at transonic speed. Experimental results for the baseline geometry of the cavity were validated with the high-fidelity lattice Boltzmann method computational fluid dynamics solver, SIMULIA PowerFLOW®. In this study, inclined and parallel cuts were applied to the front and aft walls of the M219 cavity to determine their efficiency in reducing the overall sound pressure level (OASPL). The most effective configurations on reducing OASPL at the front and aft walls were combined to form mixed configurations. All front wall and aft wall configurations as well as mixed configurations were validated through grid independence studies. Simulations showed that modifications to the aft wall were more effective in reducing noise than modifications to the front wall. The spectral analysis of pressure oscillations provided information about the broadband and tonal pressure responses of the mixed configurations. The findings showed that the mixed configurations were effective in reducing the frequency and amplitude of the Rossiter modes. The most successful configurations on noise reduction also showed a decrease in the drag coefficient and the average static pressure distribution along the cavity.
A numerical study on MHD Cu-Al2O3/H2O hybrid nanofluid with Hall current and cross-diffusion effect
Authors: Rath Chinmoy , Nayak Anita
Published: October 2023

A numerical investigation has been performed to analyze an unsteady magnetohydrodynamic gravity-driven flow of a Newtonian hybrid nanofluid (Cu-Al2O3/H2O) along an impermeable vertical plate with linearly accelerated temperature and concentration. The Hall current, nanoparticle volume fraction, inclined magnetic field, and Soret effect on water-based Cu-Al2O3 hybrid nanofluid are incorporated into the flow model. The model's governing nonlinear partial differential equations are formulated and transformed into a non-dimensional form by introducing suitable variables and parameters. The finite difference method is implemented via the MATLAB solver fsolve to resolve the model equations numerically. The evolution of the primary and secondary velocities, temperature, and species concentration profiles is discussed via graphical illustration. Furthermore, a comparative analysis is performed on the coefficient of skin friction, rate of heat, and mass transport for hybrid nanofluid and nanofluid through tabular values. The novelty of the investigation reveals that a deceleration in the primary velocity and acceleration in the secondary velocity with the increasing magnetic field inclination parameter exists. The rising value of Cu nanoparticle volume fraction augments the primary, secondary skin friction coefficients, and the heat and mass transport rates at the plate. The Dufour number stimulates a reduction in the heat transport rate, while an enhancement occurs with the Soret number. The present investigation demonstrates that the heat transfer rate for water-based Cu-Al2O3 hybrid nanofluid is higher than that for water-based Cu nanofluid. The current research can be implemented to augment the efficiency of the cooling mechanism of heat exchangers, solar collectors, nuclear reactors, and many more.
Towards lowering energy consumption during magnetron sputtering: Benefits of high-mass metal ion irradiation
Authors: Greczynski G. , Hultman L. , Petrov I.
Published: October 2023

The quest for lowering energy consumption during thin film growth by magnetron sputtering techniques becomes of particular importance in view of sustainable development goals. As large fraction of the process energy is consumed in substrate heating for the purpose of providing high adatom mobility necessary to grow dense films, the most straightforward strategy toward more environment-friendly processing is to find alternatives to thermally activated surface diffusion. One possibility is offered by high mass metal ion irradiation of the growing film surface, which has been recently shown to be very effective in densification of transition metal nitride layers grown with no external heating, such that Zone 2 microstructures of the structure-zone model are obtained in the substrate temperature Ts range otherwise typical for Zone 1 growth. The large mass difference between the incident ion and the atoms constituting the film results in effective creation of low energy recoils, which leads to film densification at low Ts. Due to their high mass, metal ions become incorporated at lattice sites beyond the near-surface region of intense recoil generation leading to further densification, while preventing the buildup of residual stress. The practical implementation of this technique discussed in this Perspective employs heavy metal targets operating in the high-power impulse magnetron sputtering (HiPIMS) mode to provide periodic metal-ion fluxes that are accelerated in the electric field of the substrate to irradiate layers deposited from direct current magnetron sputtering (DCMS) sources. A key feature of this hybrid HiPIMS/DCMS configuration is the substrate bias that is synchronized with heavy metal ion fluxes for selective control of their energy and momentum. As a consequence, the major fraction of process energy is used at sputtering sources and for film densification, rather than for heating of the entire vacuum vessel. Model material systems include TiN and metastable NaCl-structure Ti1−yAlyN films, which are well-known for challenges in stoichiometry and phase stability control, respectively, and are of high relevance for industrial applications. This Perspective provides a comprehensive overview of the novel film growth method. After presenting basic concepts, time-resolved measurements of ion fluxes at the substrate plane, essential for selective control of metal ion energy and momentum, are discussed. The role of metal ion mass, energy, momentum, and concentration is described in more detail. As some applications require substrate rotation for conformal coating, a section is devoted to the related complexity in the implementation of metal-ion-synchronized growth under industrial conditions.
Enhancing energy channel and carriers recycling in sky-blue perovskite light-emitting diodes via a fluorescent fortifier
Authors: Yang Wei , Gao Chun-Hong , Xia Yu , Wang Bin , Wang Kai-Li , Lou Yan-Hui , Wang Zhao-Kui
Published: October 2023

Metal halide perovskite materials are renowned for their exceptional photoelectric properties, holding immense promise as next-generation luminescent materials. However, challenges, such as inferior film morphology, multidimensional phase coexistence, and energy level barrier hindrance, result in carrier transport imbalance and poor confinement. The presence of numerous defects in the light-emitting layer (EML) or at the interface leads to auger recombination, hindering the attainment of high-efficiency and stable devices. To address these issues, herein, we introduce a fluorescent material named t-DABNA-dtB in a hole transport layer (HTL) as a carrier catcher, leveraging the Förster channel to enhance energy and carrier utilization. Moreover, the reduction in energy level barriers between HTL and EML ensures balanced carrier transport within the EML and effectively suppresses trap-induced non-radiative losses. Consequently, the diminished density of defect states effectively curbs luminescence quenching, leading to enhanced device stability.
Albatross movement suggests sensitivity to infrasound cues at sea
Authors: Gillies Natasha , Martín López Lucía Martina , den Ouden Olivier F. C. , Assink Jelle D. , Basille Mathieu , Clay Thomas A. , Clusella-Trullas Susana , Joo Rocío , Weimerskirch Henri , Zampolli Mario , Zeyl Jeffrey N. , Patrick Samantha C.
Published: October 2023

The ways in which seabirds navigate over very large spatial scales remain poorly understood. While olfactory and visual information can provide guidance over short distances, their range is often limited to 100s km, far below the navigational capacity of wide-ranging animals such as albatrosses. Infrasound is a form of low-frequency sound that propagates for 1,000s km in the atmosphere. In marine habitats, its association with storms and ocean surface waves could in effect make it a useful cue for anticipating environmental conditions that favor or hinder flight or be associated with profitable foraging patches. However, behavioral responses of wild birds to infrasound remain untested. Here, we explored whether wandering albatrosses,
Diomedea exulans
, respond to microbarom infrasound at sea. We used Global Positioning System tracks of 89 free-ranging albatrosses in combination with acoustic modeling to investigate whether albatrosses preferentially orientate toward areas of ‘loud’ microbarom infrasound on their foraging trips. We found that in addition to responding to winds encountered in situ, albatrosses moved toward source regions associated with higher sound pressure levels. These findings suggest that albatrosses may be responding to long-range infrasonic cues. As albatrosses depend on winds and waves for soaring flight, infrasonic cues may help albatrosses to identify environmental conditions that allow them to energetically optimize flight over long distances. Our results shed light on one of the great unresolved mysteries in nature, navigation in seemingly featureless ocean environments.
Reinventing metabolic pathways: Independent evolution of benzoxazinoids in flowering plants
Authors: Florean Matilde , Luck Katrin , Hong Benke , Nakamura Yoko , O’Connor Sarah E. , Köllner Tobias G.
Published: October 2023

Benzoxazinoids (BXDs) form a class of indole-derived specialized plant metabolites with broad antimicrobial and antifeedant properties. Unlike most specialized metabolites, which are typically lineage-specific, BXDs occur sporadically in a number of distantly related plant orders. This observation suggests that BXD biosynthesis arose independently numerous times in the plant kingdom. However, although decades of research in the grasses have led to the elucidation of the BXD pathway in the monocots, the biosynthesis of BXDs in eudicots is unknown. Here, we used a metabolomic and transcriptomic-guided approach, in combination with pathway reconstitution in
Nicotiana benthamiana,
to identify and characterize the BXD biosynthetic pathways from both
Aphelandra squarrosa
and
Lamium galeobdolon
, two phylogenetically distant eudicot species. We show that BXD biosynthesis in
A. squarrosa
and
L. galeobdolon
utilize a dual-function flavin-containing monooxygenase in place of two distinct cytochrome P450s, as is the case in the grasses. In addition, we identified evolutionarily unrelated cytochrome P450s, a 2-oxoglutarate-dependent dioxygenase, a UDP-glucosyltransferase, and a methyltransferase that were also recruited into these BXD biosynthetic pathways. Our findings constitute the discovery of BXD pathways in eudicots. Moreover, the biosynthetic enzymes of these pathways clearly demonstrate that BXDs independently arose in the plant kingdom at least three times. The heterogeneous pool of identified BXD enzymes represents a remarkable example of metabolic plasticity, in which BXDs are synthesized according to a similar chemical logic, but with an entirely different set of metabolic enzymes.
Normal and Sjogren’s syndrome models of the murine lacrimal gland studied at single-cell resolution
Authors: Rattner Amir , Heng Jacob S. , Winer Briana L. , Goff Loyal A. , Nathans Jeremy
Published: October 2023

The lacrimal gland is of central interest in ophthalmology both as the source of the aqueous component of tear fluid and as the site of autoimmune pathology in the context of Sjogren’s syndrome (SjS). To provide a foundational description of mouse lacrimal gland cell types and their patterns of gene expression, we have analyzed single-cell transcriptomes from wild-type (Balb/c) mice and from two genetically based SjS models,
MRL/lpr
and
NOD
(nonobese diabetic)
.H2b
, and defined the localization of multiple cell-type-specific protein and mRNA markers. This analysis has uncovered a previously undescribed cell type, Car6+ cells, which are located at the junction of the acini and the connecting ducts. More than a dozen secreted polypeptides that are likely to be components of tear fluid are expressed by acinar cells and show pronounced sex differences in expression. Additional examples of gene expression heterogeneity within a single cell type were identified, including a gradient of Claudin4 along the length of the ductal system and cell-to-cell heterogeneity in transcription factor expression within acinar and myoepithelial cells. The patterns of expression of channels, transporters, and pumps in acinar, Car6+, and ductal cells make strong predictions regarding the mechanisms of water and electrolyte secretion. In
MRL/lpr
and
NOD.H2b
lacrimal glands, distinctive changes in parenchymal gene expression and in immune cell subsets reveal widespread interferon responses, a T cell–dominated infiltrate in the
MRL/lpr
model, and a mixed B cell and T cell infiltrate in the
NOD.H2b
model.
A new climate externalities food knowledge test validated by item response theory and behavioural data prediction (Validación de una nueva prueba de conocimientos sobre la externalidad climática de los alimentos mediante la teoría de respuesta al ítem y la predicción a partir de datos conductuales)
Authors: Haefner Gonzalo , Schobin Janosch
Published: October 2023

Research underscores the imperative for global dietary shifts to curb global temperature rise within the Paris Agreement’s 2°C limit. Understanding human dietary behaviour is crucial for effective environmental policies promoting pro-environmental actions. A significant obstacle is the lack of awareness regarding the CO2 implications of meat and dairy consumption, hindering sustainable diet adoption. Thus, evaluating knowledge-based interventions requires reliable tools to quantify climate impact knowledge related to food consumption. Unfortunately, existing pro-environmental knowledge measurement instruments lack domain specificity, leaving a void in assessing climate-conscious food choice knowledge. Addressing this void, our climate externalities food knowledge test was developed. It underwent calibration via item response theory with a German university student sample and validation across one German and two Chilean student samples. The resulting scale exhibited a strong approximate model fit, acceptable item fit metrics, good reliability and the ability to predict climate-relevant food-choice patterns and expert group performance. However, notable differential item functioning was observed based on cultural context. Our instrument provides a valuable contribution to understanding and promoting sustainable food choices on a global scale.
Emergence of High-Temperature Superconducting Phase in Pressurized La3Ni2O7 Crystals
Authors: Hou 侯 Jun 钧 , Yang 杨 Peng-Tao 芃焘 , Liu 刘 Zi-Yi 子儀 , Li 李 Jing-Yuan 婧嫄 , Shan 单 Peng-Fei 鹏飞 , Ma 马 Liang 良 , Wang 王 Gang 罡 , Wang 王 Ning-Ning 宁宁 , Guo 郭 Hai-Zhong 海中 , Sun 孙 Jian-Ping 建平 , Uwatoko Yoshiya , Wang 王 Meng 猛 , Zhang 张 Guang-Ming 广铭 , Wang 王 Bo-Sen 铂森 , Cheng 程 Jin-Guang 金光
Published: October 2023

The recent report of pressure-induced structural transition and signature of superconductivity with T
c ≈ 80 K above 14 GPa in La3Ni2O7 crystals has garnered considerable attention. To further elaborate this discovery, we carried out comprehensive resistance measurements on La3Ni2O7 crystals grown in an optical-image floating zone furnace under oxygen pressure (15 bar) using a diamond anvil cell (DAC) and cubic anvil cell (CAC), which employ a solid (KBr) and liquid (glycerol) pressure-transmitting medium, respectively. Sample 1 measured in the DAC exhibits a semiconducting-like behavior with large resistance at low pressures and gradually becomes metallic upon compression. At pressures P ⩾ 13.7 GPa we observed the appearance of a resistance drop of as much as ∼ 50% around 70 K, which evolves into a kink-like anomaly at pressures above 40 GPa and shifts to lower temperatures gradually with increasing magnetic field. These observations are consistent with the recent report mentioned above. On the other hand, sample 2 measured in the CAC retains metallic behavior in the investigated pressure range up to 15 GPa. The hump-like anomaly in resistance around ∼ 130 K at ambient pressure disappears at P ⩾ 2 GPa. In the pressure range of 11–15 GPa we observed the gradual development of a shoulder-like anomaly in resistance at low temperatures, which evolves into a pronounced drop of resistance of 98% below 62 K at 15 GPa, reaching a temperature-independent resistance of 20 μΩ below 20 K. Similarly, this resistance anomaly can be progressively shifted to lower temperatures by applying external magnetic fields, resembling a typical superconducting transition. Measurements on sample 3 in the CAC reproduce the resistance drop at pressures above 10 GPa and realize zero resistance below 10 K at 15 GPa even though an unusual semiconducting-like behavior is retained in the normal state. Based on these results, we constructed a dome-shaped superconducting phase diagram and discuss some issues regarding the sample-dependent behaviors on pressure-induced high-temperature superconductivity in the La3Ni2O7 crystals.
Spin Hall Magnetoresistance in Pt/BiFeO3 Bilayer
Authors: He 贺 Anpeng 安鹏 , Lu 卢 Yu 羽 , Du 杜 Jun 军 , Li 李 Yufei 宇飞 , Shi 时 Zhong 钟 , Wu 吴 Di 镝 , Xu 徐 Qingyu 庆宇
Published: October 2023

Multiferroic materials are general antiferromagnets with negligibly small net magnetization, which strongly limits their magnetoelectric applications in spintronics. Spin Hall magnetoresistance (SMR) is sensitive to the orientation of the Néel vector, which can be applied for the detection of antiferromagnetic states. Here, we apply SMR on the unique room-temperature antiferromagnetic multiferroic material BiFeO3 (BFO). The angular dependence of SMR in a bilayer of epitaxial BFO (001) and heavy metal Pt is studied. By rotating the sample under a magnetic field of 80 kOe in the film plane, the resistance shows the maximum when the field is perpendicular to the current while it shows the minimum when the field is along the current. This can be well explained by the SMR in the bilayer of heavy metal/antiferromagnet with the relative orientation between the Néel vector and current direction. In contrast, the angular dependence of the resistance of Pt directly deposited on a SrTiO3 (001) substrate shows a 90° shift with the magnetic field rotating in the film plane, which originates from the Hanle magnetoresistance of Pt. The obtained spin mixing conductance at the Pt/BFO interface clearly confirms the efficient spin transmission. Our results provide a possible solution for applications of antiferromagnetic multiferroic materials in spintronics.
Nanoparticles with cubic symmetry: classification of polyhedral shapes
Authors: Hermann Klaus E
Published: October 2023

Structural studies of polyhedral bodies can help to analyze geometric details of observed crystalline nanoparticles (NP) where we consider compact polyhedra of cubic point symmetry as simple models. Their surfaces are described by facets with normal vectors along selected Cartesian directions (a, b, c) together with their symmetry equivalents forming a direction family {abc}. Here we focus on polyhedra with facets of families {100}, {110}, and {111}, suggested for metal and oxide NPs with cubic lattices. Resulting generic polyhedra, cubic, rhombohedral, octahedral, and tetrahexahedral, have been observed as NP shapes by electron microscopy. They can serve for a complete description of non-generic polyhedra as intersections of corresponding generic species, not studied by experiment so far. Their structural properties are shown to be fully determined by only three parameters, facet distances R
100, R
110, and R
111 of the three facet types. This provides a novel phase diagram to systematically classify all corresponding polyhedra. Their structural properties, such as shape, size, and facet geometry, are discussed in analytical and numerical detail with visualization of typical examples. The results may be used for respective NP simulations but also as a repository stimulating the structural interpretation of new NP shapes to be observed by experiment.
Honing in on a topological zero-bias conductance peak
Authors: Pal Subhajit , Benjamin Colin
Published: October 2023

A popular signature of Majorana bound states in topological superconductors is the quantized zero-energy conductance peak. However, a similar zero energy conductance peak can also arise due to non-topological reasons. Here we show that these trivial and topological zero energy conductance peaks can be distinguished via the zero energy local density of states (LDOSs) and local magnetization density of states (LMDOSs). We find that the zero-energy LDOSs and the LMDOSs exhibit periodic oscillations for a trivial zero-bias conductance peak (ZBCP). In contrast, these oscillations disappear for the topological ZBCP because of perfect Andreev reflection at zero energy in topological superconductor junctions. Our results suggest that the zero-energy LDOSs and the LMDOSs can be used as an experimental probe to distinguish a trivial zero-energy conductance peak from a topological zero-energy conductance peak.
Cross-domain bearing fault diagnosis method based on SMOTENC and deep transfer learning under imbalanced data
Authors: Jin Yupeng , Yang Junfeng , Yang Xu , Liu Zhongchao
Published: October 2023

The issue of cross-device fault diagnosis is a focal point in bearing fault diagnosis. Nevertheless, due to the imbalance in bearing fault data, conventional fault diagnosis methods have certain limitations in practical applications. To overcome this problem, this paper proposes a bearing fault diagnosis method based on synthetic minority over-sampling technique for nominal and continuous (SMOTENC) and deep transfer learning. Firstly, the SMOTENC algorithm is employed to oversample the imbalanced bearing vibration signals, thereby obtaining a balanced dataset. Secondly, a six-layer deep transfer neural network model is constructed, and a novel conditional distribution metric loss function is utilized to minimize the distance between the source and target domains. Lastly, the proposed method is applied to 12 cross-device bearing fault diagnosis tasks under an imbalanced dataset, and validated using three performance metrics. The research findings demonstrate that the bearing fault diagnosis method based on SMOTENC and deep transfer learning exhibits significant advantages in handling imbalanced data, offering an effective solution for research in the field of bearing fault diagnosis.
Adjustable short-term memory of SiO
x
:Ag-based memristor for reservoir computing
Authors: Li Ruiyi , Yang Haozhang , Zhang Yizhou , Tang Nan , Chen Ruiqi , Zhou Zheng , Liu Lifeng , Kang Jinfeng , Huang Peng
Published: October 2023

Temporal information processing is critical for a wide spectrum of applications, such as finance, biomedicine, and engineering. Reservoir computing (RC) can efficiently process temporal information with low training costs. Various memristors have been explored to demonstrate RC systems leveraging the short-term memory and nonlinear dynamic behaviours. However, the short-term memory is fixed after the device fabrication, limiting the applications to diverse temporal analysis tasks. In this work, we propose the approaches to modulating the short-term memory of Pt/SiO
x
:Ag/Pt memristor for the performance improvement of the RC systems. By controlling the read voltage, pulse amplitude and pulse width applied to the devices, the obtainable range of the characteristic time reaches three orders of magnitude from microseconds to around milliseconds. Based on the fabricated memristor, the classification of 4-bit pulse streams is demonstrated. Memristor-based RC systems with adjustable short-term memory are constructed for time-series prediction and pattern recognition tasks with different requirements for the characteristic times. The simulation results show that low normalized root mean square error of 0.003 (0.27) in Hénon map (Mackey–Glass time series) and excellent classification accuracy of 99.6% (91.7%) in spoken-digit recognition (MNIST image recognition) are achieved, which outperforms most memristor-based RC systems recently reported. Furthermore, the RC networks with diverse short-term memories are constructed to address more complicated tasks with low prediction errors. This work proves the high controllability of memristor-based RC systems to handle multiple temporal processing tasks.
High energy x-ray Talbot-Lau interferometer employing a microarray anode-structured target source to extend the field of view
Authors: Lin Qisi , Wu Zhao , Zan Guibin , Huang Meng , Dang Zheng , Tian Lijiao , Guan Yong , Liu Gang , Lu Yalin , Tian Yangchao
Published: October 2023

Objective. High energy and large field of view (FOV) phase contrast imaging is crucial for biological and even medical applications. Although some works have devoted to achieving a large FOV at high energy through bending gratings and so on, which would be extremely challenging in medical high energy imaging. Approach. We analyze the angular shadowing effect of planar gratings in high-energy x-ray Talbot-Lau interferometer (XTLI). Then we design and develop an inverse XTLI coupled with a microarray anode-structured target source to extend the FOV at high energy. Main results. Our experimental results demonstrate the benefit of the source in the inverse XTLI and a large FOV of 106.6 mm in the horizontal direction is achieved at 40 keV. Based on this system, experiments of a mouse demonstrate the potential advantage of phase contrast mode in imaging lung tissue. Significance. We extend the FOV in a compact XTLI using a microarray anode-structured target source coupled with an inverse geometry, which eliminates grating G0 and relaxes the fabrication difficulty of G2. We believe the established design idea and imaging system would facilitate the wide applications of XTLI in high energy phase contrast imaging.
Laser wakefield acceleration of electrons in a magnetically controlled plasma
Authors: Nikrah B , Jafari S
Published: October 2023

In the present study, the laser wakefield acceleration of electrons in a magnetically-controlled plasma is investigated. The results indicate that by employing a linearly-chirped laser pulse propagating through magnetized plasma with a reversed external magnetic field, higher energy electrons are obtained than with unmagnetized plasma and/or a nonchirped laser pulse. By considering an appropriate constant chirping magnitude and an axial external magnetic field, one can obtain remarkable GeV electron energies. It is also found that the effect of the external magnetic field direction on the electron energy is not sensed much in the mildly relativistic regime, while the reversed magnetic field increases the peak of electron energy gains compared with the forward magnetic field in the highly relativistic regime. For the mildly relativistic case, a peak energy of 412 MeV and a relative energy spread of 7% is obtained. In addition, for the highly relativistic case, a peak energy of 1.55 GeV is obtained.
In2O3 decorated TiO2 for broadband photosensing applications
Authors: B Sharmila , Dwivedi Priyanka
Published: October 2023

This paper presents the fabrication and broadband photosensing of bare TiO2 and In2O3 decorated TiO2 based photodetectors. The photosensing properties of the In2O3 decorated TiO2 were compared with the bare TiO2. The proposed photosensing devices are wafer scalable. The devices were tested in the broad spectral range from ultraviolet to near-infrared wavelengths. The In2O3 decorated TiO2 heterojunction-based photodetector showed improved photocurrent with a high photo to dark current ratio in the order of 4 × 103, which is 103 times higher than the TiO2 photodetector at 450 nm. In addition, this heterojunction based photodetector shows the responsivity and detectivity of 1415 mA W–1 and 4.97 × 1012Jones respectively. Moreover, In2O3 decorated TiO2 heterojunction shows highly repeatable results with a rise/fall time of 1.42/0.09 s. The fabricated photodetectors could have more potential in the field of broadband optical sensing.
A TOPAS model for lens-based proton radiography
Authors: Broder Brittany A , Aulwes Ethan F , Espy Michelle , Merrill Frank E , Sidebottom Rachel B , Tupa Dale , Freeman Matthew S
Published: October 2023

Objective. Proton Radiography can be used in conjunction with proton therapy for patient positioning, real-time estimates of stopping power, and adaptive therapy in regions with motion. The modeling capability shown here can be used to evaluate lens-based radiography as an instantaneous proton-based radiographic technique. The utilization of user-friendly Monte Carlo program TOPAS enables collaborators and other users to easily conduct medical- and therapy- based simulations of the Los Alamos Neutron Science Center (LANSCE). The resulting transport model is an open-source Monte Carlo package for simulations of proton and heavy ion therapy treatments and concurrent particle imaging. Approach. The four-quadrupole, magnetic lens system of the 800-MeV proton beamline at LANSCE is modeled in TOPAS. Several imaging and contrast objects were modelled to assess transmission at energies from 230–930 MeV and different levels of particle collimation. At different proton energies, the strength of the magnetic field was scaled according to βγ, the inverse product of particle relativistic velocity and particle momentum. Main results. Materials with high atomic number, Z, (gold, gallium, bone-equivalent) generated more contrast than materials with low-Z (water, lung-equivalent, adipose-equivalent). A 5-mrad collimator was beneficial for tissue-to-contrast agent contrast, while a 10-mrad collimator was best to distinguish between different high-Z materials. Assessment with a step-wedge phantom showed water-equivalent path length did not scale directly according to predicted values but could be mapped more accurately with calibration. Poor image quality was observed at low energies (230 MeV), but improved as proton energy increased, with sub-mm resolution at 630 MeV. Significance. Proton radiography becomes viable for shallow bone structures at 330 MeV, and for deeper structures at 630 MeV. Visibility improves with use of high-Z contrast agents. This modality may be particularly viable at carbon therapy centers with accelerators capable of delivering high energy protons and could be performed with carbon therapy.
Optimization strategies in WAHTOR algorithm for quantum computing empirical ansatz: a comparative study
Authors: Ratini Leonardo , Capecci Chiara , Guidoni Leonardo
Published: October 2023

By exploiting the invariance of the molecular Hamiltonian by a unitary transformation of the orbitals it is possible to significantly shorter the depth of the variational circuit in the variational quantum eigensolver (VQE) algorithm by using the wavefunction adapted Hamiltonian through orbital rotation (WAHTOR) algorithm. This work introduces a non-adiabatic version of the WAHTOR algorithm and compares its efficiency with three implementations by estimating quantum processing unit (QPU) resources in prototypical benchmarking systems. Calculating first and second-order derivatives of the Hamiltonian at fixed VQE parameters does not introduce a significant QPU overload, leading to results on small molecules that indicate the non-adiabatic Newton–Raphson method as the more convenient choice. On the contrary, we find out that in the case of Hubbard model systems the trust region non-adiabatic optimization is more efficient. The preset work therefore clearly indicates the best optimization strategies for empirical variational ansatzes, facilitating the optimization of larger variational wavefunctions for quantum computing.
PGR - 1 Average Intelligence with Rare Genetic Mutation Associated with Intellectual Disability
Authors: Cavanaugh Christopher
Published: October 2023

Objective

Chung-Jansen syndrome is caused by haploinsufficiency of pleckstrin homology domain interacting protein (PHIP). Patients identified with PHIP typically present with intellectual disability, learning disorder, atypical social behavior, facial dysmorphism and obesity. Common co-occurring clinical conditions include attention deficit hyperactivity disorder (ADHD), anxiety and/or depression, and autism spectrum disorder (ASD). Neurocognitive functioning is notable for a leftward shift, presenting with a relative strength in language comprehension and weakness in nonverbal ability.

Method

This is a 9-year-old female with an atypical PHIP mutation. The patient was born full-term. The pregnancy and delivery were uncomplicated (birth weight: 3572 grams). The PHIP mutation was identified in December 2020. Genetic testing was conducted due to developmental delay, ADHD, obesity, abnormal motor functioning, learning disability, and somatic complaints.

Results

Neuropsychological testing indicated average intellectual functioning (FSIQ = 94). There were strengths in verbal comprehension (VCI = 116), verbal learning, and reading, with relative weaknesses in non-verbal ability (NVI = 83), non-verbal learning, and math. Scores on measures of social perception (Affect Recognition, Theory of Mind) were consistent with verbal ability.

Conclusions

This is an important case in understanding Chung-Jansen syndrome and PHIP. Most key clinical features are present (e.g., ADHD, atypical social behavior, obesity), albeit at a higher level of intellectual functioning. PHIP has typically been associated with intellectual disability; the present case suggests that the clinical pattern is present with higher functioning individuals as well. Genetic testing may be warranted when evaluating individuals with average cognitive functioning and relative strengths in verbal ability along with co-occurring atypical social behavior, ADHD, and obesity.
PGR - 2 Demons In The Mirrors: A Childhood Case Report of 22q11.2 Deletion Syndrome First Addressed By Tele-Neuropsychological Evaluation During The COVID-19 Lockdown
Authors: Pizer Jasmin H , Myers Melissa A , Hill Benjamin D
Published: October 2023

Objective

22q11.2 Deletion Syndrome (22q11DS) results in physical, cognitive, and behavioral issues. Although it is the most common microdeletion syndrome, there remains a high prevalence of delayed diagnosis. Its heterogeneous phenotypic presentation lead to differing considerations for early diagnostic identification. If initial symptomatology includes behavioral and cognitive disturbance, it is likely for such individuals to be referred first for neuropsychological testing before genetic testing. This case will expand upon diagnostic identification of 22q11DS.

Method

A 12-year-old, 5-years educated, white female was seen for tele-neuropsychological evaluation due to COVID-19 restrictions in December 2020. Patient’s mother reported concern regarding sudden and worsening behavioral changes including hallucinations, unusual affects, odd beliefs, academic decline, illegible handwriting, attention and memory issues, and behavioral problems in school to the point of removal.

Results

Overall performance on the Meyers Neuropsychological Battery was severely impaired. See uploaded image file for specific test findings. Speech, affect, and behavior were notable during examination. Diagnoses included schizophrenia (provisional) and specific learning disorder with reading impairment (historical). Immediate neurology consultation was recommended. Later EEG, brain MRI, and CSF were unremarkable. Acute metabolic etiology was ruled out. Subsequent genetic testing revealed 22q11DS.

Conclusions

Diagnostic identification of 22q11DS and resulting access to care management heavily depends on initial symptom presentation. In this specific case, the COVID-19 lockdown created barrier to sufficient services. This case expands upon knowledge of the cognitive profile of 22q11DS and calls upon increased awareness. Targeted improvement of neurocognition potentially protects against cognitive decline related to psychotic symptoms, and thus neuropsychologists play a vital role in referral to such resources.
AGR - 2 Colloid Cyst: Underrecognized Neuropsychological Sequalae of a Neurosurgical Diagnosis
Authors: Bender Heidi , Bander Evan , Gavarrete-Olvera Alice , Giambrone Julia , Katsman Kseniya , Muhareb Samer , Rosen Kate , Sacks-Zimmerman Amanda , Seger Madison , Souweudane Mark , Tosi Umberto , Yap David L
Published: October 2023

Objective

Colloid cysts are a benign, fluid-filled collection often found in the rostral third ventricle at/near the foramen of Monro, accounting for 0.5–2% of all brain tumors. Modifying factors of neurocognition include: resultant hydrocephalus, mass effect, as well as size, location and laterality of cyst. The modality of neurosurgical intervention/approach also impacts the risk of post-operative neurocognitive morbidity. This grand rounds presentation reviews relevant literature - anchored by our own research - highlighting neuropsychological assessment considerations and possible interventional strategies in order to enhance outcomes in patients with colloid cyst.

Method

Neuropsychological test data evaluating 20 patients who underwent neuropsychological assessment pre- and post-endoscopic removal of a colloid cyst are discussed. Comprehensive testing included gold-standard metrics of attention, executive functioning, learning, memory, visuospatial abilities, language, motor, and mood. Neuroimaging data, surgical parameters and pre and post-neurosurgical neuropsychological test data are also presented on all patients. Additionally, a small subset of patients were evaluated post-computerized cognitive remediation to establish treatment efficacy.

Results

For each variable, a paired t-test was performed between the pre- and post-operative z-score. Only one sub-score evinced a statistically significant change post-operatively (p = 0.037), with Stroop Color-Word score improving from pre-surgical baseline. No other metric or analyzed sub-score reached statistical significance.

Conclusions

Though obtained findings argue against post-operative declines, a variety of neuroanatomical, neurosurgical, neuropsychological, and behavioral factors underscore the need for a coordinated, multi-disciplinary approach to continuity of care in this patient population, as well as others with non-cancerous brain tumors and/or cysts.
A - 4 Establishing Test–Retest Reliability of Large-Scale Neural Networks after Neurotrauma: toward Clinically Useful Biomarkers
Authors: Mullin Hollie , Carpenter Catherine M , Cwiek Andrew P , Lan Gloria , Carter Emily E , Vervoordt Samantha , Rabinowitz Amanda R , Venkatesan Umesh M , Hillary Frank G
Published: October 2023

Objective

Integrating neuropsychological assessment and resting-state functional magnetic resonance imaging (rsfMRI) may provide crucial information about brain functioning and cognition. However, rsfMRI is not ready to be used clinically due to questions about reproducibility. This study investigated the test–retest reliability of resting-state networks in moderate-to-severe TBI using back-to-back rsfMRI scans.

Method

51 TBI participants and 28 healthy controls received two, 10-minute rsfMRI scans separated by minutes. The data were preprocessed with fMRIPrep. XcpEngine was used to divide the brain into 264 regions based on the Power atlas, which were then grouped into 13 brain networks. Intraclass correlation coefficients (ICCs) were calculated to examine the reliability of within-network connectivity (strength of a region’s connection to other regions within the same network) for each network across each participant’s two scans.

Results

ICCs for healthy controls varied in reliability (ICCs = 0.42–0.80). ICCs for the TBI group varied similarly (ICCs = 0.41–0.86). For both groups, the most reliable networks were the dorsal attention, visual, and sensory networks (ICCs = 0.77–0.81). The least reliable networks were the cerebellar and ventral attention networks (ICCs = 0.42–0.43). Overlapping intervals for the ICC values indicated non-significant differences in network reliability between the healthy control and TBI groups.

Conclusions

Results suggest that within-network connectivity is more reliable in attentional and sensory networks, even after significant neurological compromise. However, the variability of within-network ICCs should continue to be explored. Alterations in network reliability may relate to changes in cognition and serve as a starting point to identify resting-state biomarkers, especially after moderate-to-severe TBI.
A - 6 Applying Artificial Intelligence Language Models for Knowledge Integration of Neuroimaging, Health Behavioral Assessment, and Clinical Intervention: Potential Impact on Brain Health in Special Operators
Authors: Chacko Thomas , Toole J Tory , Oh Hyuk , Lu Calvin , Reinhard Matthew , Brewster Ryan , Forsten Robert , Barrett John , Costanzo Michelle , Broderick Gordon
Published: October 2023

Objective

Specialized military groups like Explosive Ordnance Disposal (EOD) personnel can suffer allostatic overload leading to complex health outcomes characterized as Operator Syndrome (OS). Here we (1) evaluate Brodmann’s Areas (BA) brain regions associated with OS-related behavioral health symptoms then (2) explore how DoD/VA-recommended clinical interventions relate to these brain regions using large-scale automated text mining.

Data Selection

Neuroimaging reported by Brodmann’s Areas and 9 behavioral symptom measures and constructs of interest were extracted from full-text peer-reviewed publications using both rule-based and generative AI natural language processing (NLP) engines. The relationships linking BA regions with behavioral symptoms and the 7 interventions were assessed, with a focus on post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI) severity.

Data Synthesis

The network connected behavioral health symptoms and 39 of 52 BA regions through 131 interactions. Co-occurring PTSD and TBI associations to BA (counting ≥3 citations) were detected with the precentral gyrus (BA4), premotor cortex and supplementary motor cortex (BA6), middle temporal gyrus (BA21), superior temporal gyrus (BA22), angular gyrus (BA39), and dorsolateral prefrontal cortex (BA46). Behavioral interventions of Cognitive Processing Therapy (CPT), Prolonged Exposure Therapy, Cognitive Behavioral Therapy were found to modulate BA 6, with CPT alone also modulating BA 46. Only the pharmacotherapy fluoxetine (SSRI) related to BA6.

Conclusions

NLP offers a rapid means of exploring complex injuries in Veterans. Future investigations will test these models using acquired data from EOD veterans and specific neuroimaging modalities (e.g., BOLD fMRI) to determine how they might improve understanding of health sequelae of environmental exposures and inform intervention.
A - 7 Genome-Wide Association Study of Traumatic Brain Injury in U.S. Military Veterans
Authors: Merritt Victoria C , Maihofer Adam X , Gasperi Marianna , Ketema Elizabeth , Chanfreau-Coffinier Catherine , Stein Murray B , Panizzon Matthew S , Hauger Richard L , Logue Mark W , Delano-Wood Lisa , Nievergelt Caroline M
Published: October 2023

Objective

Large-scale genetic studies of traumatic brain injury (TBI) are lacking; thus, our understanding of the influence of genetic factors on TBI risk and recovery is incomplete. This study aimed to conduct a genome-wide association study (GWAS) of TBI in VA Million Veteran Program (MVP) enrollees.

Method

Participants included a multi-ancestry cohort (European, African, and Hispanic ancestries; N = 304,485; 111,494 TBI cases, 192,991 controls). TBI was assessed using MVP survey data and ICD codes from electronic health records. GWAS was performed using logistic regression in PLINK, and FUMA was used for post-GWAS analysis. Genetic correlations between TBI and several health domains (risk-taking behaviors, psychiatric disorders, neurocognitive variables, and brain morphometrics) were also evaluated.

Results

SNP-based heritability was 0.060 (SE = 0.004, p = 7.83x10–66). GWAS analysis identified 15 genome-wide significant loci at p < 5x10–8. Gene-based analyses revealed 14 gene-wide significant genes, including NCAM1, APOE, FTO, and FOXP2. Gene tissue expression analysis identified the brain as significantly enriched, particularly in the frontal cortex, anterior cingulate cortex, and nucleus accumbens. Genetic correlations with TBI were significant for risk-taking behaviors and psychiatric disorders, but generally non-significant for neurocognitive and brain morphometric variables. The strongest genetic correlation was with PTSD (rg = 0.69, SE = 0.04, p = 2.5x10–75).

Conclusions

This first well-powered GWAS of TBI showed that TBI is a heritable trait and identified 15 loci including genes relevant to TBI biology. Findings also revealed high genetic correlations with psychiatric and risk-taking traits, significantly advancing understanding of the genetic basis of TBI. Results set the stage for future TBI GWASs that focus on diversity and chronicity of symptom sequelae.