bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of the electromagnetic shielding efficiency of FeB and Fe2B: ab-initio calculations
Authors: Üşenti Hakan , Duru İzzet Paruğ
Published: October 2024

The electromagnetic (EM) pollution that we are exposed to in our daily lives has reached levels that threaten the health of living organisms and the stable operation of sensitive systems. The most effective way to protect against this pollution is to create isolated areas framed with shielding materials that can minimize the transmission of EM radiation. The development of shielding materials with high physical endurance against external factors to meet the needs of various sectors remains a popular research topic. This process, which started with metal plates, has continued with the development of doped polymers and composite materials. In recent years, materials with 2D structures have been developed. In this study, the shielding effectiveness (SE) of FeB and Fe2B nanostructures are revealed using ab initio calculations in Perdew–Burke–ErnzerhofSol scheme. SE has been widely figuring out via optical properties which are strongly related to mechanical and electronic properties herewith magnetic phases. The ferrimagnetic FeB and Fe2B nanostructures are considered. Besides, we focus on the thickness and photon energy dependent behavior along various projections. The findings demonstrate shielding performance at levels of >20 dB. Although both materials show similar shielding performance, it is observed that Fe2B is promising when compared to FeB. This study demonstrates that FeB and Fe2B, members of the MBene family, are promising materials not only because of their superior physical and chemical properties but also because of their shielding performance.
Reliable fabrication of 3D freestanding nanostructures via all dry stacking of incompatible photoresist
Authors: Shu Zhiwen , Liang Huikang , Chen Lei , Liu Qing , Zeng Pei , Zhou Yuting , Wang Quan , Fan Fu , Zhou Yu , Chen Yiqin , Feng Bo , Duan Huigao
Published: October 2024

Three-dimensional (3D) free-standing nanostructures based on electron-beam lithography (EBL) have potential applications in many fields with extremely high patterning resolution and design flexibility with direct writing. In numerous EBL processes designed for the creation of 3D structures, the multilayer resist system is pivotal due to its adaptability in design. Nevertheless, the compatibility of solvents between different layers of resists often restricts the variety of feasible multilayer combinations. This paper introduces an innovative approach to address the bottleneck issue by presenting a novel concept of multilayer resist dry stacking, which is facilitated by a near-zero adhesion strategy. The poly(methyl methacrylate) (PMMA) film is stacked onto the hydrogen silsesquioxane (HSQ) resist using a dry peel and release technique, effectively circumventing the issue of HSQ solubilization by PMMA solvents typically encountered during conventional spin-coating procedures. Simultaneously, a dry lift-off technique can be implemented by eschewing the use of organic solvents during the wet process. This pioneering method enables the fabrication of high-resolution 3D free-standing plasmonic nanostructures and intricate 3D free-standing nanostructures. Finally, this study presents a compelling proof of concept, showcasing the integration of 3D free-standing nanostructures, fabricated via the described technique, into the realm of Fabry–Perot cavity resonators, thereby highlighting their potential for practical applications. This approach is a promising candidate for arbitrary 3D free-standing nanostructure fabrication, which has potential applications in nanoplasmonics, nanoelectronics, and nanophotonics.
A repeated jumping solution based on the bistable film structure for film-structured miniature soft robots
Authors: Chen Huimin , Cao Shuhong , Wang Dongkai , Miao Zicong , Liu Ying , Wang Xiaohao , Zhang Min
Published: October 2024

Miniature film-structured robots achieved remarkable locomotion performance and various applications. The integration of a jumping function could empower existing film-structured terrestrial robots to conquer complex terrains. However, current repeated jumping mechanisms for miniature soft robots are often constrained to specific materials and mechanical configurations, rendering them incompatible with film-structured robots. A solution that effectively addresses these limitations remains absent in the field. This work introduces an electrically actuated solution for repeated jumping in miniature soft robots, utilizing a bistable film structure coupled with a numerical two-rod model. The bistable film structure integrates a flexible film, polydimethylsiloxane (PDMS) linear spring, and a shape memory alloy spring to achieve repeated jumping motion through snap-through buckling. The numerical model is employed to optimize the spring parameters, tailoring the structure to the specific properties of the target robot. To demonstrate the practicality of this solution, the bistable film structure is seamlessly integrated into an existing fast-steering insect robot, which previously lacks jumping capabilities. By customizing PDMS spring design based on the robot body’s dimensions and stiffness, the prototype robot, measuring 23 × 16 × 8 mm3 in size and 120 mg in weight, demonstrates repeated jumping ability with a maximum horizontal jumping distance of 11.8 cm (5.1 body lengths), a jumping height of 3.8 cm (4.7 body heights) and a jumping frequency of 0.1 Hz. The robot traverses a 43 cm-long road with half walls and trench obstacles in 41 s. This work presents the bistable film structure’s potential as a repeated jumping solution for film-structured robots, enhancing their obstacle-crossing abilities and expanding their applicability in complex environments.
Two step synthesis of g-C3N4@GO composites with enhanced photoluminescence response
Authors: Verma Shankee , Santra Bisweswar , Sakthievel Arunkumar , Alwarappan Subbiah , Katharria Y S , Kanjilal Aloke
Published: October 2024

Tuning the optical properties of graphene oxide (GO) by making composites with 2D materials has attracted considerable interest for various applications. Here, the g-C3N4@GO composite is synthesised by a two-step modified Hummer’s method with 3 wt% and 7 wt% g-C3N4. Structural and chemical properties of GO and with g-C3N4 are investigated by x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS), respectively, while scanning electron microscopy reveals a flake-like structure in g-C3N4@GO composites. Raman analysis gives an increase in ID/IG ratio from 3.1 to 3.2 due to the formation of defects for 3 wt% g-C3N4 but reduced to 2.9 with 7 wt% g-C3N4. Optical bandgap of GO (∼3.35 eV) is reduced to ∼3.30 eV (3 wt% g-C3N4) and ∼3.25 eV (7 wt% g-C3N4) with respective defect edges at ∼2.53 eV, 2.52 eV and 2.50 eV, in good agreement with the photoluminescence (PL) results. The appearance of a broad XRD peak at ∼23.2° signifies the formation of rGO by reducing GO with g-C3N4, where the existence of HO–C=O in XPS analysis reveals the formation of defects. This is found to be associated with a chemical reaction at the g-C3N4/GO interfaces and thus makes this system promising with increased PL intensity.
Lattice Boltzmann method for tempered time-fractional diffusion equation
Authors: Ren Junjie , Song Jie , Lei Hao
Published: October 2024

Tempered fractional calculus, as an extension of fractional calculus, has been successfully applied in numerous scientific and engineering fields. Although several traditional numerical methods have been improved for solving a variety of tempered fractional partial differential equations, solving these equations by the lattice Boltzmann (LB) method is an unresolved issue. This paper is dedicated to presenting a novel LB method for the tempered time-fractional diffusion equation. The tempered time-fractional diffusion equation is first transformed into an integer-order partial differential equation by approximating the tempered fractional derivative term. Then the LB method is proposed to solve the transformed objective equation. The Chapman-Enskog procedure is conducted to confirm that the present LB method can accurately recover the objective equation. Some numerical examples with an analytical solution are employed to validate the present LB method, and a strong consistency is observed between the numerical and analytical solutions. The numerical simulations indicate that the LB method is a second-order accurate scheme. The proposed LB method presents a new approach to solving the tempered time-fractional diffusion equation, which is beneficial for the widespread application of the tempered time-fractional diffusion equation in addressing complex transport problems.
An analysis of the synthesis, crystal structure, optical, spectroscopic, mechanical, self-focusing, and third-order nonlinear optical properties of Kojic acid single crystals
Authors: Lakshmi S , Saravanan M
Published: October 2024

A single, excellent crystal of Kojic acid (KA) was developed utilising the traditional approach of gradual evaporation in a solution-growing procedure. A variety of characterisation techniques were utilised to evaluate the characteristics of the crystals generated. Single crystal x-ray diffraction (SXRD) was utilised to identify the crystal structure. The crystalline arrangement of the KA crystal was confirmed using a powder x-ray diffraction (PXRD) analysis. Experiments with UV–vis spectrometers revealed that the KA crystal has a lower wavelength at which it blocks UV light but has outstanding light transmission throughout the visible spectrum. The KA single crystal has an energy band gap (Eg) of 2.5 eV. The Z-scan method was used to examine the third order susceptibility, nonlinear refraction, and nonlinear absorption coefficient of the synthesised KA crystal. The dielectric characteristics and AC conductivity were examined, with a particular emphasis on their connection to resistance at room temperature. The presence of appreciable levels of kojic acid was confirmed by energy-dispersive spectrometry. The crystal’s thermal behaviour was investigated using differential thermal analysis (DTA) and thermogravimetric (TG) methods. The nucleation parameters and controlled nucleation rate were calculated using normal theoretical research methods.
Evaluating extensions to LCDM: an application of Bayesian model averaging and selection
Authors: Paradiso S. , McGee G. , Percival W.J.
Published: October 2024

We present a powerful and innovative statistical framework to address key cosmological
questions about the universe's fundamental properties, performing Bayesian model averaging (BMA)
and model selection. Utilizing this framework, we systematically explore extensions beyond the
standard ΛCDM model, considering a varying curvature density parameter ΩK,
a spectral index ns
= 1 and a varying n
run, a constant dark energy equation of
state (EOS) w
0CDM and a time-dependent one w
0
w
aCDM. We also assess
cosmological data against a varying effective number of neutrino species N
eff. Our analysis
incorporates data from various combinations of cosmic microwave background (CMB) data from the
latest Planck PR4 analysis, CMB lensing from Planck 2018, baryonic acoustic oscillations (BAO),
and the Bicep-KECK 2018 results.

We reinforce the standard ΛCDM model statistical preference when combining CMB data with
CMB lensing, BAO, and Bicep-KECK 2018 data against the K-ΛCDM model and
dns
/d ln k-ΛCDM with a probability > 80%. When
evaluating the dark energy EOS, we find that this dataset does not exhibit a strong preference
between the standard ΛCDM model and the constant dark energy EOS model w
0CDM,
with a model posterior probability distribution of approximately ≈ 40%:60% in favour of
 w
0CDM, while the time-varying dark energy EOS model only holds below 1%
probability. We find a similar result also when considering the N
eff-ΛCDM model, with a
split probability almost 50%-50% from both our datasets.

Overall, our application of BMA reveals that including model uncertainty in these cases does not
significantly impact the Hubble tension, showcasing BMA's robustness and utility in cosmological
model evaluation.
Impact of strain relaxation on the growth rate of heteroepitaxial germanium tin binary alloy
Authors: Jahandar Pedram , Myronov Maksym
Published: October 2024

The growth of high-quality germanium tin (Ge1–y
Sn
y
) binary alloys on a Si substrate using chemical vapor deposition (CVD) techniques holds immense potential for advancing electronics and optoelectronics applications, including the development of efficient and low-cost mid-infrared detectors and light sources. However, achieving precise control over the Sn concentration and strain relaxation of the Ge1–y
Sn
y
epilayer, which directly influence its optical and electrical properties, remain a significant challenge. In this research, the effect of strain relaxation on the growth rate of Ge1–y
Sn
y
epilayers, with Sn concentration >11at.%, is investigated. It is successfully demonstrated that the growth rate slows down by ~55% due to strain relaxation after passing its critical thickness, which suggests a reduction in the incorporation of Ge into Ge1–y
Sn
y
growing layers. Despite the increase in Sn concentration as a result of the decrease in the growth rate, it has been found that the Sn incorporation rate into Ge1–y
Sn
y
growing layers has also decreased due to strain relaxation. Such valuable insights could offer a foundation for the development of innovative growth techniques aimed at achieving high-quality Ge1–y
Sn
y
epilayers with tuned Sn concentration and strain relaxation.
Improved efficiency and stability of inverse perovskite solar cells via passivation cleaning
Authors: Ge Kunyang , Liang Chunjun
Published: October 2024

Amidst the global energy and environmental crisis, the quest for efficient solar energy utilization intensifies. Perovskite solar cells, with efficiencies over 26% and cost-effective production, are at the forefront of research. Yet, their stability remains a barrier to industrial application. This study introduces innovative strategies to enhance the stability of inverted perovskite solar cells. By bulk and surface passivation, defect density is reduced, followed by a "passivation cleaning" using Apacl amino acid salt and isopropyl alcohol to refine film surface quality. Employing X-ray diffraction (XRD), scanning electron microscope (SEM), and atomic force microscopy (AFM), we confirmed that this process effectively neutralizes surface defects and curbs non-radiative recombination, achieving 22.6% efficiency for perovskite solar cells with the composition Cs0.15FA0.85PbI3. Crucially, the stability of treated cells in long-term tests has been markedly enhanced, laying groundwork for industrial viability.
SSA-over-array (SSoA): A stacked DRAM architecture for near-memory computing
Authors: Jiang Xiping , Bai Fujun , Wang Song , Guo Yixin , Zuo Fengguo , Xiao Wenwu , Wang Yubing , Yang Jianguo , Liu Ming
Published: October 2024

Aiming to enhance the bandwidth in near-memory computing, this paper proposes a SSA-over-array (SSoA) architecture. By relocating the secondary sense amplifier (SSA) from dynamic random access memory (DRAM) to the logic die and repositioning the DRAM-to-logic stacking interface closer to the DRAM core, the SSoA overcomes the layout and area limitations of SSA and master DQ (MDQ), leading to improvements in DRAM data-width density and frequency, significantly enhancing bandwidth density. The quantitative evaluation results show a 70.18 times improvement in bandwidth per unit area over the baseline, with a maximum bandwidth of 168.296 Tbps/Gb. We believe the SSoA is poised to redefine near-memory computing development strategies.
Influence of internal heating and natural convection on airborne transmission of viral diseases
Authors: Patel R , Krishnaprasad K A , Zgheib N , Salinas J S , Balachandar S
Published: October 2024

We conduct large eddy simulations in a canonical room of size

10
×
10
×
3.2

m
3

subject to mechanical ventilation to assess the impact of internal heating on droplet nuclei dispersal in indoor spaces. We conduct two simulations with a solitary heat source placed at the center of the room in the first, and 16 heat sources arranged in an equidistant non-staggered formation in the second. The heat sources mimic heat generation from an adult person. The simulations employ a statistical overloading approach where 10 million droplet nuclei are individually monitored for approximately one hour in real-time. These results are then compared to previous simulations that share identical setup and procedures but do not account for any thermal load. We assess the effect of internal heat sources on multiple levels by averaging over all possible positions of the infected (source) and the susceptible (sink) occupants within the room. We find that, at the room-average level, the room concentration, which results from a balance of droplet nuclei production through expiratory events and removal through various mechanisms is unaffected by the presence of heat sources. On the other hand, the spatial and temporal dispersion of droplet nuclei, as observed from the standpoint of a known source or sink location, or when a combination of sources and sinks at fixed separation distances is considered, is significantly influenced by the presence of heat sources.
Improved rate-distance trade-offs for quantum codes with restricted connectivity
Authors: Baspin Nouédyn , Guruswami Venkatesan , Krishna Anirudh , Li Ray
Published: October 2024

For quantum error-correcting codes to be realizable, it is important that the qubits subject to the code constraints exhibit some form of limited connectivity. The works of Bravyi and Terhal (2009 New J. Phys.
11 043029) (BT) and Bravyi et al (2010 Phys. Rev. Lett.
104 050503) (BPT) established that geometric locality constrains code properties—for instance

[

[
n
,
k
,
d
]

]

quantum codes defined by local checks on the D-dimensional lattice must obey

k

d

2

/

(
D
−
1
)

⩽
O
(
n
)

. Baspin and Krishna (2022 Quantum
6 711) studied the more general question of how the connectivity graph associated with a quantum code constrains the code parameters. These trade-offs apply to a richer class of codes compared to the BPT and BT bounds, which only capture geometrically-local codes. We extend and improve this work, establishing a tighter dimension-distance trade-off as a function of the size of separators in the connectivity graph. We also obtain a distance bound that covers all stabilizer codes with a particular separation profile, rather than only LDPC codes.
Physical coherent cancellation of optical addressing crosstalk in a trapped-ion experiment
Authors: Flannery Jeremy , Matt Roland , Huber Luca I , Wang Kaizhao , Axline Christopher , Oswald Robin , Home Jonathan P
Published: October 2024

We present an experimental investigation of coherent crosstalk cancellation methods for light delivered to a linear ion chain cryogenic quantum register. The ions are individually addressed using focused laser beams oriented perpendicular to the crystal axis, which are created by imaging each output of a multi-core photonic-crystal fibre waveguide array onto a single ion. The measured nearest-neighbor native crosstalk intensity of this device for ions spaced by 5 µm is found to be

∼

10

−
2

. We show that we can suppress this intensity crosstalk from waveguide channel coupling and optical diffraction effects by a factor

>

10
3

using cancellation light supplied to neighboring channels which destructively interferes with the crosstalk. We measure a rotation error per gate on the order of

ϵ

x

∼

10

−
5

on spectator qubits, demonstrating a suppression of crosstalk error by a factor of

>

10
2

. We compare the performance to composite pulse methods for crosstalk cancellation, and describe the appropriate calibration methods and procedures to mitigate phase drifts between these different optical paths, including accounting for problems arising due to pulsing of optical modulators.
Enhanced O3 concentration due to biogenic emissions during a hot summer in 2018 over the Tokyo metropolitan area, Japan
Authors: Miki Kenji , Itahashi Syuichi
Published: October 2024

Photochemical ozone (O3) is an important chemical component in the atmosphere as an indicator of air pollution. Anthropogenic sources, such as domestic automobiles and industries, have been considered a main source of O3 especially in urban areas; however, recent emission regulations have led to declining trends in anthropogenic sources. Therefore, other sources, such as biogenic emissions, could be important in the near future. In addition, increasing temperatures caused by global warming will relate to increasing biogenic emissions. In this study, the role of biogenic volatile organic compounds (BVOC) on O3 concentration was focused. The target period was a hot summer in 2018 in Japan, and O3 concentration by simulating with and without biogenic emissions over the Tokyo metropolitan area was analyzed. The result clarified that around 20% (up to 63%) of O3 was produced from biogenic sources at high temperatures, even in the Tokyo metropolitan area. This study suggested that the biogenic sources should be paid attention to and taken into account in the regulation of anthropogenic emissions.
Cuspidal cohomology classes for 𝐺𝐿_{𝑛}(𝐙)
Authors: Boxer George , Calegari Frank , Gee Toby
Published: October 2024

We prove the existence of a cuspidal automorphic representation 

π
\pi

for 

GL

79

⁡

/

Q

\operatorname {GL}_{79}/\mathbf {Q}

of level one and weight zero. We construct 

π
\pi

using symmetric power functoriality and a change of weight theorem, using Galois deformation theory. As a corollary, we construct the first known cuspidal cohomology classes in

H
∗

(

GL

n

⁡
(

Z

)
,

C

)

H^*(\operatorname {GL}_{n}(\mathbf {Z}),\mathbf {C})

for any 

n
>
1

n > 1

.
A unified structure-preserving parametric finite element method for anisotropic surface diffusion
Authors: Bao Weizhu , Li Yifei
Published: October 2024

We propose and analyze a unified structure-preserving parametric finite element method (SP-PFEM) for the anisotropic surface diffusion of curves in two dimensions

(
d
=
2
)

(d=2)

and surfaces in three dimensions

(
d
=
3
)

(d=3)

with an arbitrary anisotropic surface energy density

γ
(
n
)

\gamma (\boldsymbol {n})

, where

n
∈

S

d
−
1

\boldsymbol {n}\in \mathbb {S}^{d-1}

represents the outward unit vector. By introducing a novel unified surface energy matrix

G
k

(
n
)

\boldsymbol {G}_k(\boldsymbol {n})

depending on

γ
(
n
)

\gamma (\boldsymbol {n})

, the Cahn-Hoffman

ξ
\boldsymbol {\xi }

-vector and a stabilizing function

k
(
n
)
:
 

S

d
−
1

→

R

k(\boldsymbol {n}):\ \mathbb {S}^{d-1}\to {\mathbb R}

, we obtain a unified and conservative variational formulation for the anisotropic surface diffusion via different surface differential operators, including the surface gradient operator, the surface divergence operator and the surface Laplace-Beltrami operator. A SP-PFEM discretization is presented for the variational problem. In order to establish the unconditional energy stability of the proposed SP-PFEM under a very mild condition on

γ
(
n
)

\gamma (\boldsymbol {n})

, we propose a new framework via local energy estimate for proving energy stability/structure-preserving properties of the parametric finite element method for the anisotropic surface diffusion. This framework sheds light on how to prove unconditional energy stability of other numerical methods for geometric partial differential equations. Extensive numerical results are reported to demonstrate the efficiency and accuracy as well as structure-preserving properties of the proposed SP-PFEM for the anisotropic surface diffusion with arbitrary anisotropic surface energy density

γ
(
n
)

\gamma (\boldsymbol {n})

arising from different applications.
On the computation of lattice sums without translational invariance
Authors: Buchheit Andreas , Keßler Torsten , Serkh Kirill
Published: October 2024

This paper introduces a new method for the efficient computation of oscillatory multidimensional lattice sums in geometries with boundaries. Such sums are ubiquitous in both pure and applied mathematics and have immediate applications in condensed matter and topological quantum physics. The challenge in their evaluation results from the combination of singular long-range interactions with the loss of translational invariance caused by the boundaries, rendering standard tools like Ewald summation ineffective. Our work shows that these lattice sums can be generated from a generalization of the Riemann zeta function to multidimensional non-periodic lattice sums. We put forth a new representation of this zeta function together with a numerical algorithm that ensures exponential convergence across an extensive range of geometries. Notably, our method’s runtime is influenced only by the complexity of the considered geometries and not by the number of particles, providing the foundation for efficient and precise simulations of macroscopic condensed matter systems. We showcase the practical utility of our method by computing interaction energies in a three-dimensional crystal structure with

3
×

10

23

3\times 10^{23}

particles. Our method’s accuracy is demonstrated through extensive numerical experiments. A reference implementation is provided online along with this article.
Borel Vizing’s theorem for graphs of subexponential growth
Authors: Bernshteyn Anton , Dhawan Abhishek
Published: October 2024

We show that every Borel graph

G
G

of subexponential growth has a Borel proper edge-coloring with

Δ
(
G
)
+
1

\Delta (G) + 1

colors. We deduce this from a stronger result, namely that an

n
n

-vertex (finite) graph

G
G

of subexponential growth can be properly edge-colored using

Δ
(
G
)
+
1

\Delta (G) + 1

colors by an

O
(

log
∗

⁡
n
)

O(\log ^\ast n)

-round deterministic distributed algorithm in the LOCAL model, where the implied constants in the

O
(
⋅
)

O(\cdot )

notation are determined by a bound on the growth rate of

G
G

.
On vector measures with values in 𝑐₀(𝜅)
Authors: Rodríguez José
Published: October 2024

Let

ν
\nu

be a vector measure defined on a

σ
\sigma

-algebra 

Σ
\Sigma

and taking values in a Banach space. We prove that if

ν
\nu

is homogeneous and

L
1

(
ν
)

L_1(\nu )

is non-separable, then there is a vector measure

ν
~

:
Σ
→

c
0

(
κ
)

\tilde {\nu }:\Sigma \to c_0(\kappa )

such that

L
1

(
ν
)
=

L
1

(

ν
~

)

L_1(\nu )=L_1(\tilde {\nu })

with equal norms, where

κ
\kappa

is the density character of 

L
1

(
ν
)

L_1(\nu )

. This is a non-separable version of a result of G.P. Curbera [Pacific J. Math. 162 (1994), pp. 287–303].
𝐵𝑉-structure on Hochschild cohomology for exceptional local algebras of quaternion type. The case of an even parameter
Authors: Generalov A. , Semenov A.
Published: October 2024

A full description is provided for the

B
V

BV

-structure on the Hochschild cohomology of exceptional local algebras of quaternion type determined by parameters

(
k
,
0
,
d
)

(k,0,d)

in the case of an even parameter

k
≥
3

k \geq 3

, according to Erdmann’s classification. The method of comparison morphisms and the weak self-homotopy method are developed and used. This article may be viewed as a generalization of similar results about the

B
V

BV

-structures on the Hochschild cohomology of algebras of quaternion type.
Invariant subspaces of analytic perturbations
Authors: Das S. , Sarkar J.
Published: October 2024

Analytic perturbations are understood here as shifts of the form

M
z

+
F

M_z + F

, where

M
z

M_z

is the unilateral shift and

F
F

is a finite rank operator on the Hardy space over the open unit disk. Here the term “a shift” refers to the multiplication operator

M
z

M_z

on some analytic reproducing kernel Hilbert space. In this paper, first, a natural class of finite rank operators is isolated for which the corresponding perturbations are analytic, and then a complete classification of invariant subspaces of those analytic perturbations is presented. Some instructive examples and several distinctive properties (like cyclicity, essential normality, hyponormality, etc.) of analytic perturbations are also described.
On the set of values of a positive ternary quadratic form
Authors: Filonov N.
Published: October 2024

It is shown that the set of values of an integer positive definite quadratic form in three variables contains an infinite arithmetic progression.
Degrees of points on varieties over Henselian fields
Authors: Creutz Brendan , Viray Bianca
Published: October 2024

Let

W

/

K

W/K

be a nonempty scheme over the field of fractions of a Henselian local ring

R
R

. A result of Gabber, Liu and Lorenzini [Invent. Math. 192 (2013), pp. 567–626] shows that the

G
C
D

GCD

of the set of degrees of closed points on

W
W

(which is called the index of

W

/

K

W/K

) can be computed from data pertaining only to the special fiber of a proper regular model of

W
W

over

R
R

. We show that the entire set of degrees of closed points on

W
W

can be computed from data pertaining only to the special fiber, provided the special fiber is a strict normal crossings divisor.

As a consequence we obtain an algorithm to compute the degree set of any smooth curve over a Henselian field with finite or algebraically closed residue field. Using this we show that degree sets of curves over such fields can be dramatically different than degree sets of curves over finitely generated fields. For example, while the degree set of a curve over a finitely generated field contains all sufficiently large multiples of the index, there are curves over

p
p

-adic fields with index

1
1

whose degree set excludes all integers that are coprime to

6
6

.
Geriatric medicine and Olympic elite sports—parallels and philosophies
Authors: McDonald Claire , Sayer Avan A , Witham Miles D
Published: October 2024

The 30th Olympiad took place in July 2024. At first glance, sports science and training of elite athletes may appear to be of little relevance to geriatric medicine. However, there are important parallels between the practice of geriatric medicine and elite sports and lessons that we can learn from our sports science colleagues. Elite athletes and older people are operating at the margins of physiological capacity. Both benefit from tailored, scientifically informed training programmes delivered and monitored by a multidisciplinary team. There are parallels between the comprehensive geriatric assessment and the philosophy of marginal gains pioneered by British Cycling. Insights into the biology of skeletal muscle function are beginning to translate into the development of clinical interventions and substances that offer an unfair advantage in sport by improving muscle strength and physical performance may be of therapeutic benefit in sarcopenia. The 2024 Olympics provide an opportunity for us to learn lessons for excellence in our research and provide an opportunity to promote exercise across the life course—important for healthy ageing.
Intersection between person-centred practice and Montessori for dementia and ageing in residential aged care
Authors: Woolford Marta , Bruce Lauren , Rigoni Daniella , Gulline Hannah , Horsman Phillipa , MacRae Ann , Berkovic Danielle , Morawaka Niluksha , Alberti Silvia , Skouteris Helen , Ayton Darshini
Published: October 2024

Background

Internationally, person-centred care (PCC) is embedded in the language of regulations and mandated to be practised in residential aged care (RAC). Despite this, PCC has not been fully adopted in RAC in Australia and internationally, and concerns about the quality of care persist. Over the past 2 decades, Montessori for dementia and ageing has been introduced in RAC to support and inform a cultural change towards PCC. This study aimed to examine the intersection between the goals and approaches of Montessori and PCC in RAC.

Methods

This qualitative descriptive study reports on a secondary analysis of qualitative data from focus groups (FGs) and interviews with residents, family-members, staff, and volunteers from eight RAC homes in Victoria, Australia. Sixteen FGs and 36 interviews were conducted. A qualitative deductive approach using researcher-developed Montessori for dementia and ageing framework for data analysis was applied.

Results

Findings provide support for the intersection between PCC and Montessori with participants’ descriptions of PCC aligning with many of the goals and approaches of Montessori. Participants most commonly described Montessori approaches of engagement in daily tasks with purposeful roles and promoting cognitive abilities through multi-sensory stimulation. Least frequently-described approaches included focusing on residents’ strengths/abilities, maintaining function, using familiar objects, and guided repetition.

Conclusions

Findings have important implications for practice to use Montessori as a vehicle that supports and upskills the workforce to deliver care that is person-centred. Future research must examine the resources required to support the implementation and sustainability of Montessori as a vehicle for PCC.
Molecular genetic regulation of the vegetative–generative transition in wheat from an environmental perspective
Authors: Kiss Tibor , Horváth Ádám D , Cseh András , Berki Zita , Balla Krisztina , Karsai Ildikó
Published: October 2024

The key to the wide geographical distribution of wheat is its high adaptability. One of the most commonly used methods for studying adaptation is investigation of the transition between the vegetative–generative phase and the subsequent intensive stem elongation process. These processes are determined largely by changes in ambient temperature, the diurnal and annual periodicity of daylength, and the composition of the light spectrum. Many genes are involved in the perception of external environmental signals, forming a complex network of interconnections that are then integrated by a few integrator genes. This hierarchical cascade system ensures the precise occurrence of the developmental stages that enable maximum productivity. This review presents the interrelationship of molecular–genetic pathways (Earliness per se, circadian/photoperiod length, vernalization – cold requirement, phytohormonal – gibberellic acid, light perception, ambient temperature perception and ageing – miRNA) responsible for environmental adaptation in wheat. Detailed molecular genetic mapping of wheat adaptability will allow breeders to incorporate new alleles that will create varieties best adapted to local environmental conditions.
Unpacking unstructured data: A pilot study on extracting insights from neuropathological reports of Parkinson’s Disease patients using large language models
Authors: Stroganov Oleg , Schedlbauer Amber , Lorenzen Emily , Kadhim Alex , Lobanova Anna , Lewis David A , Glausier Jill R
Published: October 2024

The aim of this study was to make unstructured neuropathological data, located in the NeuroBioBank (NBB), follow Findability, Accessibility, Interoperability, and Reusability principles and investigate the potential of large language models (LLMs) in wrangling unstructured neuropathological reports. By making the currently inconsistent and disparate data findable, our overarching goal was to enhance research output and speed. The NBB catalog currently includes information from medical records, interview results, and neuropathological reports. These reports contain crucial information necessary for conducting an in-depth analysis of NBB data but have multiple formats that vary across different NBB biorepositories and change over time. In this study, we focused on a subset of 822 donors with Parkinson’s disease (PD) from seven NBB biorepositories. We developed a data model with combined Brain Region and Pathological Findings data at its core. This approach made it easier to build an extraction pipeline and was flexible enough to convert resulting data to Common Data Elements, a standardized data collection tool used by the neuroscience community to improve consistency and facilitate data sharing across studies. This pilot study demonstrated the potential of LLMs in structuring unstructured neuropathological reports of PD patients available in the NBB. The pipeline enabled successful extraction of detailed tissue-level (microscopic) and gross anatomical (macroscopic) observations, along with staging information from pathology reports, with extraction quality comparable to manual curation results. To our knowledge, this is the first attempt to automatically standardize neuropathological information at this scale. The collected data have the potential to serve as a valuable resource for PD researchers, facilitating integration with clinical information and genetic data (such as genome-wide genotyping and whole-genome sequencing) available through the NBB, thereby enabling a more comprehensive understanding of the disease.
A retrospective audit of an artificial intelligence software for the detection of intracranial haemorrhage used by a teleradiology company in the United Kingdom
Authors: Pettet Garry , West Julie , Robert Dennis , Khetani Aneesh , Kumar Shamie , Golla Satish , Lavis Robert
Published: October 2024

Objectives

Artificial intelligence (AI) algorithms have the potential to assist radiologists in the reporting of head computed tomography (CT) scans. We investigated the performance of an AI-based software device used in a large teleradiology practice for intracranial haemorrhage (ICH) detection.

Methods

A randomly selected subset of all non-contrast CT head (NCCTH) scans from patients aged ≥18 years referred for urgent teleradiology reporting from 44 different hospitals within the United Kingdom over a 4-month period was considered for this evaluation. Thirty auditing radiologists evaluated the NCCTH scans and the AI output retrospectively. Agreement between AI and auditing radiologists is reported along with failure analysis.

Results

A total of 1315 NCCTH scans from as many distinct patients (median age, 73 years [IQR 53-84]; 696 [52.9%] females) were evaluated. One hundred twelve (8.5%) scans had ICH. Overall agreement, positive percent agreement, negative percent agreement, and Gwet’s AC1 of AI with radiologists were found to be 93.5% (95% CI, 92.1-94.8), 85.7% (77.8-91.6), 94.3% (92.8-95.5) and 0.92 (0.90-0.94), respectively, in detecting ICH. 9 out of 16 false negative outcomes were due to missed subarachnoid haemorrhages and these were predominantly subtle haemorrhages. The most common reason for false positive results was due to motion artefacts.

Conclusions

AI demonstrated very good agreement with the radiologists in the detection of ICH.

Advances in knowledge

Real-world evaluation of an AI-based CT head interpretation device is reported. Knowledge of scenarios where false negative and false positive results are possible will help reporting radiologists.
Encephalitis lethargica: clinical features and aetiology
Authors: Rogers Jonathan P , Mastellari Tomas , Berry Alex J , Kumar Kieron , Burchill Ella , David Anthony S , Lewis Glyn , Lees Andrew , Zandi Michael S
Published: October 2024

Encephalitis lethargica, an epidemic neurological illness, typically involved a severe sleep disorder and progressive parkinsonism. A century later, our understanding relies on seminal descriptions, more recent historical research and the study of small numbers of possible sporadic cases. Theories around infection, environmental toxins, catatonia and autoimmune encephalitis have been proposed. We aimed to describe the presentation of encephalitis lethargica and test these diagnostic and aetiological theories. Subjects with encephalitis lethargica were identified in the archives of the National Hospital for Neurology and Neurosurgery, UK between 1918 and 1946. Case notes were examined to establish illness temporality, clinical features and cerebrospinal fluid results. Controls from the archives were identified for 10% of cases, matching on discharge year, sex and neurologist. Clinical presentation was compared to modern diagnostic criteria for encephalitis lethargica, catatonia and autoimmune encephalitis. In a case–control design, a multilevel logistic regression was conducted to ascertain whether cases of encephalitis lethargica were associated with febrile illnesses and with environmental exposures. Six hundred and fourteen cases of encephalitis lethargica and 65 controls were identified. Cases had a median age of 29 years (interquartile range 18) and a median time since symptomatic onset of 3.00 years (interquartile range 3.52). Motor features were present in 97.6%, cranial nerve findings in 91.0%, ophthalmological features in 77.4%, sleep disorders in 66.1%, gastrointestinal or nutritional features in 62.1%, speech disorders in 60.8% and psychiatric features in 53.9%. Of the 167 cases who underwent lumbar puncture, 20 (12.0%) had a pleocytosis. The Howard and Lees criteria for encephalitis lethargica had a sensitivity of 28.5% and specificity of 96.9%. Among the cases, 195 (31.8%, 95% confidence interval 28.1–35.6%) had a history of febrile illness within one calendar year prior to illness onset, which was more common than among the controls (odds ratio 2.70, 95% confidence interval 1.02–7.20, P = 0.05), but there was substantial reporting bias. There was no evidence that occupational exposure to solvents or heavy metals was associated with encephalitis lethargica. Two hundred and seventy-six (45.0%) of the cases might meet criteria for possible autoimmune encephalitis, but only 3 (0.5%) might meet criteria for probable NMDA receptor encephalitis. Only 11 cases (1.8%) met criteria for catatonia. Encephalitis lethargica has a distinct identity as a neuropsychiatric condition with a wide range of clinical features. Evidence for a relationship with infectious or occupational exposures was weak. Autoimmune encephalitis may be an explanation, but typical cases were inconsistent with NMDA receptor encephalitis.
Quantifying epileptic networks: every data point brings us a step closer to an optimized surgery
Authors: Thomas John , Jaber Kassem , Frauscher Birgit
Published: October 2024

This scientific commentary refers to ‘The sixth sense: how much does interictal intracranial EEG add to determining the focality of epileptic networks?’, by Gallagher et al. (https://doi.org/10.1093/braincomms/fcae320).
Two pressure-induced molecular superconductors with different types of crystal and electronic structures derived from an unsymmetrical tetrachalcogenafulvalene
Authors: Uebe Masashi , Minamidate Takaaki , Cui Hengbo , Oshima Yugo , Kato Reizo
Published: October 2024

We newly synthesized an organic donor molecule ETTM-STF (ethylenedithio(trimethylene)diselenadithiafulvalene), a molecular hybrid of HMTTF (hexamethylenetetrathiafulvalene) and BETS (bis(ethylenedithio)tetraselenafulvalene). Electrochemical oxidation of ETTM-STF provided two cation radical salts, (ETTM-STF)2Au(CN)2 and (ETTM-STF)2BF4. Crystal structure of the Au(CN)2 salt is characterized by a monolayer structure based on dimerized donor molecules. On the other hand, the BF4 salt shows a bilayer structure that is composed of two crystallographically independent conducting layers with different types of electronic structures. At ambient pressure, the Au(CN)2 salt is a Mott insulator and the BF4 salt undergoes a metal–nonmetal transition where the two types of conducting layers exhibit different behavior. Application of pressure suppressed the nonconducting behavior and induced a superconducting state in the Au(CN)2 salt (Tc = 3.4 K at 9.5 kbar) and in the BF4 salt (Tc = 6.8 K at 8 kbar).
Efficacy and safety of atenolol vs. propranolol for treatment of infantile haemangioma: a narrative review
Authors: Shi Michelle , Wargon Orli , Tatian Artiene
Published: October 2024

Infantile haemangioma (IH) remains the most common benign vascular tumour in childhood. Although most IH can be managed conservatively, a proportion of these lesions can cause disfigurement, ulceration or functional impairment, requiring prompt intervention. Propranolol, a lipophilic nonselective beta blocker, has been regarded as first-line therapy, following a serendipitous discovery of its use for IH in 2008. Although efficacious, it has been associated with adverse effects such as hypoglycaemia, bronchospasm, sleep disturbances and agitation in infant trials. Atenolol, a hydrophilic beta-1 selective blocker, has demonstrated similar efficacy and potentially greater tolerability, being less likely to cause sleep disturbances given its inability to cross the blood–brain barrier, and a decrease in bronchial reactivity. The purpose of this review is to explore and critique current knowledge about the efficacy and safety of propranolol vs. atenolol in children with an IH. In total, seven studies comparing the two beta blockers were identified in our search. Atenolol appeared to be as efficacious as propranolol and was associated with fewer central nervous system and bronchial-related adverse events. Further research exploring the optimal dosing for atenolol, particularly for ulcerated or syndromic IHs, as well as the incidence and management of rebound growth would be beneficial.
Uncovering neural substrates across Alzheimer’s disease stages using contrastive variational autoencoder
Authors: Tang Yan , Yang Chao , Wang Yuqi , Zhang Yunhao , Xin Jiang , Zhang Hao , Xie Hua ,   For the Alzheimer’s Disease Metabolomics Consortium
Published: October 2024

Alzheimer’s disease is the most common major neurocognitive disorder. Although currently, no cure exists, understanding the neurobiological substrate underlying Alzheimer’s disease progression will facilitate early diagnosis and treatment, slow disease progression, and improve prognosis. In this study, we aimed to understand the morphological changes underlying Alzheimer’s disease progression using structural magnetic resonance imaging data from cognitively normal individuals, individuals with mild cognitive impairment, and Alzheimer’s disease via a contrastive variational autoencoder model. We used contrastive variational autoencoder to generate synthetic data to boost the downstream classification performance. Due to the ability to parse out the nonclinical factors such as age and gender, contrastive variational autoencoder facilitated a purer comparison between different Alzheimer’s disease stages to identify the pathological changes specific to Alzheimer’s disease progression. We showed that brain morphological changes across Alzheimer’s disease stages were significantly associated with individuals’ neurofilament light chain concentration, a potential biomarker for Alzheimer’s disease, highlighting the biological plausibility of our results.
Copper(II) triflate-mediated addition reaction of 2-tributylstannyl-1,3-dithiane with imines
Authors: Kagoshima Hirotaka , Kawamoto Junki , Takeo Yuki , Narui Yuta , Ohkubo Shiori , Kawai Tomoya
Published: October 2024

The addition of 2-tributylstannyl-1,3-dithiane to imines was achieved using copper(II) triflate in MeNO2 at room temperature. Furthermore, this reaction can be applied to various aromatic and heteroaromatic imines. Consequently, the corresponding α-amino-1,3-dithiane derivatives were efficiently and readily synthesized under mild conditions.
Closed-chest robotic mitral repair using a semi-rigid ring inserted through a trocar
Authors: Sandoval Elena , Morales-Rey Ignacio , Bartolozzi Luis , Sanchez Jesús , Pereda Daniel
Published: October 2024

There are several types of annuloplasty devices for mitral repair. We present a totally-thoracoscopic robotic mitral repair using a new semi-rigid ring with a nitinol core that makes it malleable so that it can be inserted through a trocar. This technique combines the advantages of semi-rigid rings and a totally-thoracoscopic approach, which may further expand this approach to other aetiologies.