bluuebunny/crossref_metadata_2025 huggingface dataset:
Processing recycled silicone powder in liquid silicone rubber injection molding and its influence on mechanical properties
Authors: Mayer Dennis , Heienbrock Simon J. , Weißer Dennis F. , Deckert Matthias H.
Published: June 2024

Liquid silicone rubber (LSR) is characterized by a wide range of advantageous properties and is therefore used in many branches and industries. However, the material is difficult to recycle due to the non‐reversible cross‐linking reaction. A promising approach to recycle the already cross‐linked (post‐industrial) waste is the mechanical recycling of LSR via grinding and addition of the powder as filler in virgin material. This research focused on the processing of such LSR‐powder‐compounds via injection molding and the influence of the powder content on mechanical properties. Compounds of virgin LSR and ambient ground powder were prepared and injection molded. Both the processability and the mechanical properties were analyzed. Compounds of up to 40 wt% powder content could be processed with standard injection molding machine equipment without any noticeable issues. The results show a similar compression set for the virgin as for the recycled compounds. Hardness decreases slightly but constantly. Tensile strength and elongation at break are at similar levels for all powder added compounds and drop only by 16.6% and 12.6% compared with the virgin LSR. The results are promising and should be the basis for further and more detailed investigations to industrialize the mechanical recycling of LSR.

Highlights

Processing on standard injection molding machine with standard parameters.

Up to 40 wt% recycled silicone powder content.

Using recycled silicone particles has no effect on compression set.

Tensile strength and elongation at break decrease only by 16.6% and 12.6%.
Low temperature aging induced conjugated polymers aggregation by UV–Vis spectroscopy
Authors: Chu Zhaoyang , Guo Hang , Yu Wanchen , Sun Zhe , Chen Wei
Published: June 2024

Multiscale structural evolution of conjugated polymer (CP) solutions from disorder to aggregation via environmental perturbations is a universal phenomenon in condensed matter physics. Here, we take poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) as a model material and use Ultraviolet–Visible (UV–Vis) spectroscopy to study the hierarchical structure evolution during prolonged aging at relatively low temperature. Using in‐situ UV–Vis spectroscopy and the Franck‐Condon (FC) method, the dynamics of multiscale structural transitions in P3HT were elucidated. Hierarchical structural details can be extracted from the UV–Vis spectra, including the overall percentage of aggregates, conjugation length, degree of H‐/J‐type molecular packing, and site energetic disorder. Through covariance analysis of conformational disorder to aggregation transitions of conjugated polymers obtained under multiple conditions, we find that the trends of the above four key parameters are not consistent, which informs the unique evolution of the degree of ordering at different length scales within the aggregates. This work facilitates the scrutiny of the hierarchical structural transition from multi‐length scale perspective.
Self‐healing and cell adhesion properties of dynamic and photo‐crosslinking PEG‐based dual networks soft hydrogels
Authors: Yasar Merve , Oktay Burcu , Gurkan Ajda Coker , Apohan Nilhan Kayaman
Published: June 2024

Self‐healing involves an autonomic response that repairs damage to living systems. In this study, polyethylene glycol (PEG) underwent aldehyde‐functionalization using the Albrigh Goldman oxidation technique. Flexible, dynamic crosslink points to encourage self‐healing are generated by the formation of acylhydrazone bonds formed between long‐chain PEG dialdehyde and adipic acid dihydrazide. Furthermore, methacrylated PEG was synthesized to support the polymer matrix through dynamic covalent bonds. The hydrogels exhibited self‐healing within the first 4 hours at room temperature and after 24 h. hydrogels with mechanical performance close to the original were obtained. They have good tensile and elongation strength and are well‐suited for interaction with living cells.
Assessing the functional roles of coevolving PHD finger residues
Authors: Basu Shraddha , Subedi Ujwal , Tonelli Marco , Afshinpour Maral , Tiwari Nitija , Fuentes Ernesto J. , Chakravarty Suvobrata
Published: June 2024

Although in silico folding based on coevolving residue constraints in the deep‐learning era has transformed protein structure prediction, the contributions of coevolving residues to protein folding, stability, and other functions in physical contexts remain to be clarified and experimentally validated. Herein, the PHD finger module, a well‐known histone reader with distinct subtypes containing subtype‐specific coevolving residues, was used as a model to experimentally assess the contributions of coevolving residues and to clarify their specific roles. The results of the assessment, including proteolysis and thermal unfolding of wildtype and mutant proteins, suggested that coevolving residues have varying contributions, despite their large in silico constraints. Residue positions with large constraints were found to contribute to stability in one subtype but not others. Computational sequence design and generative model‐based energy estimates of individual structures were also implemented to complement the experimental assessment. Sequence design and energy estimates distinguish coevolving residues that contribute to folding from those that do not. The results of proteolytic analysis of mutations at positions contributing to folding were consistent with those suggested by sequence design and energy estimation. Thus, we report a comprehensive assessment of the contributions of coevolving residues, as well as a strategy based on a combination of approaches that should enable detailed understanding of the residue contributions in other large protein families.
Antigen‐binding fragments with improved crystal lattice packing and enhanced conformational flexibility at the elbow region as crystallization chaperones
Authors: Bruce Heather A. , Singer Alexander U. , Blazer Levi L. , Luu Khanh , Ploder Lynda , Pavlenco Alevtina , Kurinov Igor , Adams Jarrett J. , Sidhu Sachdev S.
Published: June 2024

It has been shown previously that a set of three modifications—termed S1, Crystal Kappa, and elbow—act synergistically to improve the crystallizability of an antigen‐binding fragment (Fab) framework. Here, we prepared a phage‐displayed library and performed crystallization screenings to identify additional substitutions—located near the heavy‐chain elbow region—which cooperate with the S1, Crystal Kappa, and elbow modifications to increase expression and improve crystallizability of the Fab framework even further. One substitution (K141Q) supports the signature Crystal Kappa‐mediated Fab:Fab crystal lattice packing interaction. Another substitution (E172G) improves the compatibility of the elbow modification with the Fab framework by alleviating some of the strain incurred by the shortened and bulkier elbow linker region. A third substitution (F170W) generates a split‐Fab conformation, resulting in a powerful crystal lattice packing interaction comprising the biological interaction interface between the variable heavy and light chain domains. In sum, we have used K141Q, E172G, and F170W substitutions—which complement the S1, Crystal Kappa, and elbow modifications—to generate a set of highly crystallizable Fab frameworks that can be used as chaperones to enable facile elucidation of Fab:antigen complex structures by x‐ray crystallography.
Adaptive sliding mode boundary control of a perturbed diffusion process
Authors: Mayr Paul , Orlov Yury , Pisano Alessandro , Koch Stefan , Reichhartinger Markus
Published: June 2024

This paper proposes a sliding‐mode‐based adaptive boundary control law for stabilizing a class of uncertain diffusion processes affected by a matched disturbance. The matched disturbance is assumed to be uniformly bounded along with its time derivative, whereas the corresponding upper bounding constants are not known. This motivates the use of adaptive control strategies. In addition, the spatially‐varying diffusion coefficient is also uncertain. To achieve asymptotic stability of the plant origin in the ‐sense in the presence of the disturbance, a discontinuous boundary feedback law is proposed where the gain of the discontinuous control term is adjusted according to a gradient‐based adaptation law. A constructive Lyapunov analysis supports the stability properties of the considered closed‐loop system, yielding sufficient convergence conditions in terms of suitable inequalities involving the controllers' tuning parameters. Simulation results are presented to corroborate the theoretical findings.
Observer‐based fixed‐time task‐space cooperative tracking control of networked Lagrangian agents with quantized communication
Authors: Ding Teng‐Fei , Zhang Qiu‐Yue , Ge Ming‐Feng , Liu Jie , Park Ju H.
Published: June 2024

In this article, the task‐space cooperative tracking control (TSCTC) problem of networked Lagrangian agents (NLAs) with quantized communication is investigated in fixed time, where every Lagrangian agent suffers from imprecise dynamics and external disturbances. A hierarchical observer‐based fixed‐time control (HOBFTC) algorithm is proposed, where there are four parts: a prescribed‐time input observer is proposed to recover the unknown input of the leader, a distributed estimator control is designed to force the estimated values to converge the states (position and velocity) of the leader, a fixed‐time disturbance observer is presented to recover the total disturbances of NLAs, and a nonsingular fixed‐time local control is given to guarantee that the task‐space cooperative tracking can be achieved. The salient features are twofold: (1) by employing the hierarchical control strategy, the proposed control algorithm is clearly structured to solve the complex cooperative tracking problem with multiple constraints including quantized communication, imprecise dynamics and external disturbances. (2) the convergence time of the proposed control algorithm can be set freely by selecting some parameters, which are independent of the initial conditions. Some sufficient conditions are obtained and some simulation examples are given to validate the effectiveness of the proposed algorithm.
Adaptive Neuro‐Fuzzy Inference System‐Long Short‐Term Memory Hybrid Model to Forecast Castability of Al‐Killed Steel Prior to Continuous Casting
Authors: Kuthe Sudhanshu , Oña Izaskun Alonso , Glaser Björn
Published: June 2024

Continuous casting of aluminum (Al) deoxidized steels demands careful inspection due to the occurrence of submerged entry nozzle (SEN) clogging, leading to unexpected production stops. Recognizing the castability of a specific “cast” by monitoring the condition of the SEN is essential for uninterrupted casting. With this information prior to casting, operators can take preventive action against possible clogging occurrences, thus reducing unplanned downtimes. In response to the severe implications of SEN clogging, this work introduces a novel way to forecast castability of Al‐killed steels. A hybrid model is proposed that integrates the adaptive neuro‐fuzzy inference system (ANFIS) and long short‐term memory (LSTM) networks. The output of the model helps to anticipate the event of clogging by analyzing both the past condition of the SEN and changes in the steel chemistry during the transport of the steel ladle from refining to the casting process. A comprehensive analysis of 150 casts helped to build the ANFIS algorithm for estimating the castability index (CI) parameter from steel chemistry. LSTM algorithm is used as a subsequent step to forecast castability in the next 20–25 min. Discrepancies between the predictive response and the actual conditions are reported. Although the real‐time implementation of the proposed model is the ultimate goal, the focus of this work was to present the methodology and demonstrate its potential.
Solving the missing at random problem in semi‐supervised learning: An inverse probability weighting method
Authors: Su Jin , Zhang Shuyi , Zhou Yong
Published: June 2024

We propose an estimator for the population mean under the semi‐supervised learning setting with the Missing at Random (MAR) assumption. This setting assumes that the probability of observing , denoted by , depends on the total sample size and satisfies . To efficiently estimate , we introduce an adaptive estimator based on inverse probability weighting and cross‐fitting. Theoretical analysis reveals that our proposed estimator is consistent and efficient, with a convergence rate of , slower than the typical rate, due to the diminishing proportion of labelled data as the sample size increases in the semi‐supervised setting. We also prove the consistency of inverse probability weighting (IPW)–Nadaraya–Watson density function estimators. Extensive simulations and an application to the Los Angeles homeless data validate the effectiveness of our approach.
Machine learning for genomic and pedigree prediction in sugarcane
Authors: Inamori Minoru , Kimura Tatsuro , Mori Masaaki , Tarumoto Yusuke , Hattori Taiichiro , Hayano Michiko , Umeda Makoto , Iwata Hiroyoshi
Published: June 2024

Sugarcane (Saccharum spp.) plays a crucial role in global sugar production; however, the efficiency of breeding programs has been hindered by its heterozygous polyploid genomes. Considering non‐additive genetic effects is essential in genome prediction (GP) models of crops with highly heterozygous polyploid genomes. This study incorporates non‐additive genetic effects and pedigree information using machine learning methods to track sugarcane breeding lines and enhance the prediction by assessing the degree of association between genotypes. This study measured the stalk biomass and sugar content of 297 clones from 87 families within a breeding population used in the Japanese sugarcane breeding program. Subsequently, we conducted analyses based on the marker genotypes of 33,149 single‐nucleotide polymorphisms. To validate the accuracy of GP in the population, we first predicted the prediction accuracy of the best linear unbiased prediction (BLUP) based on a genomic relationship matrix. Prediction accuracy was assessed using two different cross‐validation methods: repeated 10‐fold cross‐validation and leave‐one‐family‐out cross‐validation. The accuracy of GP of the first and second methods ranged from 0.36 to 0.74 and 0.15 to 0.63, respectively. Next, we compared the prediction accuracy of BLUP and two machine learning methods: random forests and simulation annealing ensemble (SAE), a newly developed machine learning method that explicitly models the interaction between variables. Both pedigree and genomic information were utilized as input in these methods. Through repeated 10‐fold cross‐validation, we found that the accuracy of the machine learning methods consistently surpassed that of BLUP in most cases. In leave‐one‐family‐out cross‐validation, SAE demonstrated the highest accuracy among the methods. These results underscore the effectiveness of GP in Japanese sugarcane breeding and highlight the significant potential of machine learning methods.
Thermal and flow dynamics of blood‐based Casson hybrid nanofluid under transient conditions
Authors: Kolsi Lioua , Khan Sami Ullah , Al‐Khaled Kamel , Benabdallah Faiza , Ghachem Kaouther , Albalawi Hind
Published: June 2024

Owing to enhanced performance, the hybrid nanofluids are finding increasingly varied applications in areas such as energy systems, extrusion operations, industrial activities, and chemical processes. The aim of current model is to explore thermal behavior of Casson hybrid nanofluid flow when subjected to a magnetic force. Two types of carbon nanotubes, the single‐walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs), dispersed in blood were investigated. The study addressed the problem based on time‐dependent thermal conductivity and considering an external heat source. It is important to understand how heat transfer occurs in nanofluids with variable thermal conductivity because it is a significant feature in many thermodynamic systems where nanofluids play important roles. To formulate the set of dimensionless governing equations, similarity variables are employed. The numerical shooting method, known for its high precision, is applied to solve these equations. The accuracy of the solutions is verified by comparison with results from previous studies, and the impact of various parameters is examined. It is noticed that velocity profile declined due to unsteady parameter for both types of CNTs (SWCNTs‐MWCNTs). An increase in the nanoparticles' volume fraction results in elevated temperatures.
Kind, Karriere – kein Problem?
Authors: Voß Julia , Meyer zu Altenschildesche Clara , Ettl Kerstin
Published: June 2024

Die Fallstudie porträtiert den Weg von Carmen Kim, einst eine hochbezahlte und angesehene Führungskraft in der Pharmabranche, die nach ihrer Elternzeit vor der Herausforderung steht, zukünftig Beruf und Familie vereinbaren zu müssen. Zwischen dem Stigma der potenziellen „Rabenmutter“ aus ihrem privaten Umfeld und der Sorge, im Unternehmen als „nicht belastbar“ betrachtet zu werden, scheint kein konventioneller Karriereweg mehr für sie möglich zu sein. In diesem Dilemma findet sie die Inspiration, ihr eigenes Unternehmen zu gründen und nun selbst Lösungen zur Vereinbarkeit von Beruf und Familie für andere Organisationen anzubieten. Der Fall verdeutlicht den Einfluss gesellschaftlicher Rollenerwartungen auf Karrierepfade von Müttern und zeigt dabei nicht nur die Dringlichkeit der Überwindung bestehender Hürden, sondern auch wie gemachte Erfahrungen zur Flexibilisierung von Karriere- und Berufswegen führen und Auslöser von Innovationen sein können.
Hilbert series for covariants and their applications to minimal flavor violation
Authors: Grinstein Benjamín , Lu Xiaochuan , Merlo Luca , Quílez Pablo
Published: June 2024

Abstract

We elaborate how to apply the Hilbert series method to enumerating group covariants, which transform under any given representation, including but going beyond group invariants. Mathematically, group covariants form a module over the ring of the invariants. The number of independent covariants is given by the rank of the module, which can be computed by taking a ratio of two Hilbert series. In many cases, the rank equals the dimension of the group covariant representation. When this happens, we say that there is a rank saturation. We apply this technology to revisit the hypothesis of Minimal Flavor Violation in constructing Effective Field Theories beyond the Standard Model. We find that rank saturation is guaranteed in this case, leading to the important consequence that the MFV symmetry principle does not impose any restriction on the EFT, i.e. MFV SMEFT = SMEFT, in the absence of additional assumptions.
Earth-catalyzed detection of magnetic inelastic dark matter with photons in large underground detectors
Authors: Eby Joshua , Fox Patrick J. , Kribs Graham D.
Published: June 2024

Abstract

Inelastic dark matter with moderate splittings, $$ \mathcal{O} $$
O
(few to 150) keV, can upscatter to an excited state in the Earth, with the excited state subsequently decaying, leaving a distinctive monoenergetic photon signal in large underground detectors. The photon signal can exhibit sidereal-daily modulation, providing excellent separation from backgrounds. Using a detailed numerical simulation, we examine this process as a search strategy for magnetic inelastic dark matter with the dark matter mass near the weak scale, where the upscatter to the excited state and decay proceed through the same magnetic dipole transition operator. At lower inelastic splittings, the scattering is dominated by moderate mass elements in the Earth with high spin, especially 27Al, while at larger splittings, 56Fe becomes the dominant target. We show that the proposed large volume gaseous detector CYGNUS will have excellent sensitivity to this signal. Xenon detectors also provide excellent sensitivity through the inelastic nuclear recoil signal, and if a future signal is seen, we show that the synergy among both types of detection can provide strong evidence for magnetic inelastic dark matter. In the course we have calculated nuclear response functions for elements relevant for scattering in the Earth, which are publicly available on GitHub.
On a generalized notion of metrics
Authors: Beyn Wolf-Jürgen
Published: June 2024

In these notes we generalize the notion of a (pseudo) metric measuring the distance of two points, to a (pseudo) n-metric which assigns a value to a tuple of $$n \ge 2$$

n
≥
2

points. Some elementary properties of pseudo n-metrics are provided and their construction via exterior products is investigated. We discuss some examples from the geometry of Euclidean vector spaces leading to pseudo n-metrics on the unit sphere, on the Stiefel manifold, and on the Grassmann manifold. Further, we construct a pseudo n-metric on hypergraphs and discuss the problem of generalizing the Hausdorff metric for closed sets to a pseudo n-metric.
WTAP and m6A-modified circRNAs modulation during stress response in acute myeloid leukemia progenitor cells
Authors: Iaiza Alessia , Mazzanti Gilla , Goeman Frauke , Cesaro Bianca , Cortile Clelia , Corleone Giacomo , Tito Claudia , Liccardo Francesca , De Angelis Luciana , Petrozza Vincenzo , Masciarelli Silvia , Blandino Giovanni , Fanciulli Maurizio , Fatica Alessandro , Fontemaggi Giulia , Fazi Francesco
Published: June 2024

N6-methyladenosine (m6A) is one of the most prevalent and conserved RNA modifications. It controls several biological processes, including the biogenesis and function of circular RNAs (circRNAs), which are a class of covalently closed-single stranded RNAs. Several studies have revealed that proteotoxic stress response induction could be a relevant anticancer therapy in Acute Myeloid Leukemia (AML). Furthermore, a strong molecular interaction between the m6A mRNA modification factors and the suppression of the proteotoxic stress response has emerged. Since the proteasome inhibition leading to the imbalance in protein homeostasis is strictly linked to the stress response induction, we investigated the role of Bortezomib (Btz) on m6A regulation and in particular its impact on the modulation of m6A-modified circRNAs expression. Here, we show that treating AML cells with Btz downregulated the expression of the m6A regulator WTAP at translational level, mainly because of increased oxidative stress. Indeed, Btz treatment promoted oxidative stress, with ROS generation and HMOX-1 activation and administration of the reducing agent N-acetylcysteine restored WTAP expression. Additionally, we identified m6A-modified circRNAs modulated by Btz treatment, including circHIPK3, which is implicated in protein folding and oxidative stress regulation. These results highlight the intricate molecular networks involved in oxidative and ER stress induction in AML cells following proteotoxic stress response, laying the groundwork for future therapeutic strategies targeting these pathways.
Essential Self-Adjointness of Even-Order, Strongly Singular, Homogeneous Half-Line Differential Operators
Authors: Gesztesy Fritz , Hunziker Markus , Teschl Gerald
Published: June 2024

We consider essential self-adjointness on the space

$$C_0^{\infty }((0,\infty ))$$

C
0
∞

(

(
0
,
∞
)

)

of even-order, strongly singular, homogeneous differential operators associated with differential expressions of the type

$$\begin{aligned} \tau _{2n}(c) = (-1)^n \frac{d^{2n}}{d x^{2n}} + \frac{c}{x^{2n}}, \quad x > 0, \; n \in {{\mathbb {N}}}, \; c \in {{\mathbb {R}}}, \end{aligned}$$

τ

2
n

(
c
)

=

(
-
1
)

n

d

2
n

d

x

2
n

+

c

x

2
n

,

x
>
0
,

n
∈
N
,

c
∈
R
,

in

$$L^2((0,\infty );dx)$$

L
2

(

(
0
,
∞
)

;
d
x
)

. While the special case

$$n=1$$

n
=
1

is classical and it is well known that

$$\tau _2(c)\big |_{C_0^{\infty }((0,\infty ))}$$

τ
2

(
c
)

|

C
0
∞

(

(
0
,
∞
)

)

is essentially self-adjoint if and only if

$$c \ge 3/4$$

c
≥
3
/
4

, the case

$$n \in {{\mathbb {N}}}$$

n
∈
N

,

$$n \ge 2$$

n
≥
2

, is far from obvious. In particular, it is not at all clear from the outset that

$$\begin{aligned} \begin{aligned}&\textit{there exists }c_n \in {{\mathbb {R}}}, n \in {{\mathbb {N}}}\textit{, such that} \\&\quad \tau _{2n}(c)\big |_{C_0^{\infty }((0,\infty ))} \, \textit{ is essentially self-adjoint}\quad \quad \quad \quad \quad \quad \quad \quad \quad \quad (*)\\ {}&\quad \textit{ if and only if } c \ge c_n. \end{aligned} \end{aligned}$$

there exists

c
n

∈
R
,
n
∈
N
,

such that

τ

2
n

(
c
)

|

C
0
∞

(

(
0
,
∞
)

)

is essentially

self
-
adjoint

(

∗
)

if and

only if

c
≥

c
n

.

As one of the principal results of this paper we indeed establish the existence of

$$c_n$$

c
n

, satisfying

$$c_n \ge (4n-1)!!\big /2^{2n}$$

c
n

≥

(
4
n
-
1
)

!
!

/

2

2
n

, such that property (*) holds. In sharp contrast to the analogous lower semiboundedness question,

$$\begin{aligned} \textit{for which values of }c\textit{ is }\tau _{2n}(c)\big |_{C_0^{\infty }((0,\infty ))}{} \textit{ bounded from below?}, \end{aligned}$$

for which

values of

c

is

τ

2
n

(
c
)

|

C
0
∞

(

(
0
,
∞
)

)

bounded from

below
?
,

which permits the sharp (and explicit) answer

$$c \ge [(2n -1)!!]^{2}\big /2^{2n}$$

c
≥

[

(
2
n
-
1
)

!
!
]

2

/

2

2
n

,

$$n \in {{\mathbb {N}}}$$

n
∈
N

, the answer for (*) is surprisingly complex and involves various aspects of the geometry and analytical theory of polynomials. For completeness we record explicitly,

$$\begin{aligned} c_{1}&= 3/4, \quad c_{2 }= 45, \quad c_{3 } = 2240 \big (214+7 \sqrt{1009}\,\big )\big /27, \end{aligned}$$

c
1

=
3
/
4
,

c
2

=
45
,

c
3

=
2240

(

214
+
7

1009

)

/

27
,

and remark that

$$c_n$$

c
n

is the root of a polynomial of degree

$$n-1$$

n
-
1

. We demonstrate that for

$$n=6,7$$

n
=
6
,
7

,

$$c_n$$

c
n

are algebraic numbers not expressible as radicals over

$${{\mathbb {Q}}}$$

Q

(and conjecture this is in fact true for general

$$n \ge 6$$

n
≥
6

).
Computed tomography as distortion mitigation method for selective laser sintering mass production
Authors: Marczis Attila , Odrobina Miklós , Drégelyi-Kiss Ágota
Published: June 2024

Most additive manufacturing (AM) technologies use heat to fuse materials together to create the manufactured part. The heat used in the AM process distorts the parts. Powder bed–based 3D printers can print multiple parts in their build chamber. The distortion is not uniform across the different locations of the build volume. Parts printed in different locations will have different thermal histories and therefore different distortions. In some cases, the achievable accuracy of the parts is insufficient due to the distortion. Subtractive processes such as milling, turning, and grinding make it difficult or impossible to improve part accuracy. For AM to produce more accurate parts, a distortion reduction method must be implemented. To take advantage of the ability to print multiple parts in a powder-based polymer 3D printing process in one build unit, a distortion mitigation technique must be applied to all the parts being printed simultaneously in the build chamber. The performance of the distortion mitigation method can be evaluated by measuring the dimensional accuracy of the uncompensated and compensated parts. Uncompensated 3D printing uses the nominal 3D model, which is the normal use of the 3D printers. Compensated 3D printing uses a distorted 3D model that is used for the printing. The 3D model is compensated with the reversed distortion data obtained from uncompensated manufacturing. X-ray computed tomography (XCT) is the chosen measurement method to extract the point cloud for the dimensional measurements. Unlike optical 3D scanners and coordinate measuring machines (CMM), the XCT is able to measure undercut and internal surfaces. The nominal difference % is improved by 18% by using compensation for the 3D models in the case of distances between two parallel planes. The standard deviation of the measured values was also improved. The distortion reduction method studied can significantly reduce the calibration errors of the 3D printer build chamber. When the tolerances of the parts are close to the limit of the 3D printer, this method can reduce the number of rejected parts. The XCT measurement of the parts is costly, so this method can be cost effective for high value parts or large production volumes.
A Classification of G-Charge Thouless Pumps in 1D Invertible States
Authors: Bachmann Sven , De Roeck Wojciech , Fraas Martin , Jappens Tijl
Published: June 2024

Recently, a theory has been proposed that classifies cyclic processes of symmetry protected topological (SPT) quantum states. For the case of spin chains, i.e. one-dimensional bosonic SPT’s, this theory implies that cyclic processes are classified by zero-dimensional SPT’s. This is often described as a generalization of Thouless pumps, with the original Thouless pump corresponding to the case where the symmetry group is U(1) and pumps are classified by an integer that corresponds to the charge pumped per cycle. In this paper, we review this one-dimensional theory in an explicit and rigorous setting and we provide a proof for the completeness of the proposed classification for compact symmetry groups G.
Thermal conductivities and complex network properties of fractal self-assembled/self-organized texture in binary composite materials
Authors: Munakata Fumio , Ogiya Taito , Sato Yoshihiro
Published: June 2024

To investigate the relationship between histological properties and thermal conductivities of binary self-assembled/self-organized fractal materials fabricated by the mixed diffusion of filler particles, the particle group distribution of the filler particles was analyzed. Unlike conventional research on particle size distribution, we performed an analysis that focuses on interactions and connectivity between particles from the perspective of the Barabasi-Albert model. In three complex network systems of β-Si3N4 (SN)/austenitic stainless steel (SUS), SN/piezoelectric polyvinylidene fluoride (PVDF), and BaTiO3 (BT)/PVDF, the size distribution of secondary particles was a power-law distribution until the particle group grew relatively large. In the SN/SUS and SN/PVDF systems, a crossover phenomenon was observed in which the order distribution exhibited a power-law in the region where the particle group area was small, and as the particle group became larger, the order distribution became exponential distribution. On the other hand, the BT/PVDF system deviated from the power law distribution as the particle group area increased but did not exhibit an exponential distribution. The characteristics of the particle group distribution of these filler particles were closely related to thermal conductivity, indicating that the connection of particle groups was important. Furthermore, the relationship between the multifractal capacitance dimension, which is strongly correlated with the distance between the particle groups, and the total number of filler particle groups suggests that the texture of these composite material systems may have both small-world and scale-free properties. We also focused on the relationship between the multifractal and complex network properties of the three particle groups. As a result, a correlation was found between the slope γ, which reflects the characteristics of the power distribution, and the thermodynamic parameter α (corresponding to internal energy change) obtained from multifractals. In particular, the smaller the change in γ relative to the change in α, the more pronounced the bonding of particles and particle groups, while the larger change in γ suggested the dispersion of particle groups.
NET burden in left atrial blood is associated with biomarkers of thrombosis and cardiac injury in patients with enlarged left atria
Authors: Martinod Kimberly , Claessen Annika , Martens Caroline , Krauel Krystin , Velásquez Pereira Leydi Carolina , Witsch Jens , Witsch Thilo
Published: June 2024

Background

Emerging data suggest an association between left atrial (LA) enlargement, thrombus formation, and ischemic stroke. However, it is unknown what may mediate such clot formation in LA dysfunction. Neutrophils promote large vessel occlusion and microthrombosis via neutrophil extracellular trap (NET) release, thus lying at the interface of inflammation, thrombosis, and fibrosis.

Approach

We conducted a prospective all-comers cohort study in patients undergoing catheterization procedures with atrial transseptal access (MitraClip, MC; left atrial appendage closure, LAAC; pulmonary vein ablation, PVA; patent foramen ovale closure, PFO). We measured NETs, cytokines, thrombotic factors, and cardiac injury markers in paired blood samples collected from peripheral blood and within the left atrium. We correlated these biomarkers with echocardiographic measures of LA structure and function (including left atrial volume index, LAVI). Data were analyzed by procedure type, and stratified by LAVI or atrial fibrillation (AF) status.

Results

We enrolled 70 patients (mean age 64 years, 53% women). NETs, but not other markers, were elevated in LA compared to peripheral blood samples. Most thrombotic, inflammatory, and cardiac damage markers were elevated in LAs from MC or LAAC compared to PFO patients. Overall, NET biomarkers positively correlated with VWF, LAVI, and markers of cardiac injury and negatively with ADAMTS13 activity. LA enlargement and the presence of AF similarly stratified patients based on thromboinflammation measurements, but this was not limited to AF at the time of sample collection.

Conclusion

Elevated NETs and VWF in patients with enlarged LA or AF suggest enhanced thromboinflammation within the LA.
Evaluation of machine learning-based classification of clinical impairment and prediction of clinical worsening in multiple sclerosis
Authors: Noteboom Samantha , Seiler Moritz , Chien Claudia , Rane Roshan P. , Barkhof Frederik , Strijbis Eva M. M. , Paul Friedemann , Schoonheim Menno M. , Ritter Kerstin
Published: June 2024

Background

Robust predictive models of clinical impairment and worsening in multiple sclerosis (MS) are needed to identify patients at risk and optimize treatment strategies.

Objective

To evaluate whether machine learning (ML) methods can classify clinical impairment and predict worsening in people with MS (pwMS) and, if so, which combination of clinical and magnetic resonance imaging (MRI) features and ML algorithm is optimal.

Methods

We used baseline clinical and structural MRI data from two MS cohorts (Berlin: n = 125, Amsterdam: n = 330) to evaluate the capability of five ML models in classifying clinical impairment at baseline and predicting future clinical worsening over a follow-up of 2 and 5 years. Clinical worsening was defined by increases in the Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk Test (T25FW), 9-Hole Peg Test (9HPT), or Symbol Digit Modalities Test (SDMT). Different combinations of clinical and volumetric MRI measures were systematically assessed in predicting clinical outcomes. ML models were evaluated using Monte Carlo cross-validation, area under the curve (AUC), and permutation testing to assess significance.

Results

The ML models significantly determined clinical impairment at baseline for the Amsterdam cohort, but did not reach significance for predicting clinical worsening over a follow-up of 2 and 5 years. High disability (EDSS ≥ 4) was best determined by a support vector machine (SVM) classifier using clinical and global MRI volumes (AUC = 0.83 ± 0.07, p = 0.015). Impaired cognition (SDMT Z-score ≤ −1.5) was best determined by a SVM using regional MRI volumes (thalamus, ventricles, lesions, and hippocampus), reaching an AUC of 0.73 ± 0.04 (p = 0.008).

Conclusion

ML models could aid in classifying pwMS with clinical impairment and identify relevant biomarkers, but prediction of clinical worsening is an unmet need.
Understanding the associations between receipt of, and interest in, advice from a healthcare professional and quality of life in individuals with a stoma from colorectal cancer: a latent profile analysis
Authors: Goodman William , Downing Amy , Allsop Matthew , Munro Julie , Hubbard Gill , Beeken Rebecca J
Published: June 2024

Purpose

To explore whether profiles derived from self-reported quality of life were associated with receipt of, and interest in, advice from a healthcare professional in people with a stoma.

Methods

Secondary analysis of cross-sectional national survey data from England of 4487 people with a stoma from colorectal cancer. The survey assessed quality of life using various scales, receipt and interest in various forms of advice, and physical activity. A three-step latent profile analysis was conducted to determine the optimum number of profiles. Multinomial regression explored factors associated with profile membership. A series of logistic regression models examined whether profile membership was associated with interest in advice.

Results

Five profiles were identified; ‘consistently good quality of life’, ‘functional issues’, ‘functional and financial issues’, ‘low quality of life’ and ‘supported but struggling’. Individuals in the ‘functional and financial issues’ and ‘low quality of life’ profiles were more likely to have received financial advice compared to the ‘consistently good quality of life’ profile. When compared to the ‘consistently good quality of life’ profile, all other profiles were more likely to report wanting advice across a range of areas, with the strongest associations in the ‘low quality of life’ profile.

Conclusion

Findings indicate that people with a stoma are not a homogenous group in terms of quality of life. Participants in profiles with quality of life concerns report wanting more advice across various categories but findings suggest there is scope to explore how this can be tailored or adapted to specific groups.
Health professionals’ perceptions of prehabilitation before haematopoietic cell transplantation to optimise candidacy in older adults
Authors: Guinan E. , Heuston C. , Sheill G. , Chonghaile M. Ní , Orfali N.
Published: June 2024

Purpose

Haematologic malignancies for the most part are diseases of the elderly. Haematopoietic stem cell transplantation (HSCT) remains the only potentially curative strategy for many patients but carries substantial morbidity and mortality risks, particularly in frail or co-morbid patients. Pre-transplant optimisation of key targets through prehabilitation may have significant clinical impact.

Methods

We utilised qualitative methodology (semi-structured interviews) to gain insights and understanding of the perceptions of medical, nursing and allied health professionals towards prehabilitation before haematopoietic cell transplantation to optimise candidacy in older adults. Thematic analysis was performed using a qualitative descriptive approach completed in duplicate by two researchers.

Results

Between August and October 2023, eleven health professionals participated from four large cancer centres across the island of Ireland (n = 3 consultant haematologists, n = 7 specialist haematology nurses and n = 1 senior haematology physiotherapist). Four major themes were identified. The themes comprehensive biopsychosocial care and increasing demand for transplant in older patients highlight the unique challenges impacting older adults who receive HSCT. The multimodality pathways of care theme highlights the heterogeneity of treatment pathways across different clinical sites and disease types. This has implications for the prehabilitation: logistics and benefits theme, which indicated strong support for prehabilitation but emphasised that implementation must consider national reach and context.

Conclusions

There is broad national multidisciplinary interest in the development of prehabilitation programmes for patients being considered for transplant. Our results will inform the development of services in this area in consideration of national reach, malignancy-specific pathways and the unique factors associated with older age.
Total hip arthroplasty for fractured neck of femur does not restore preoperative hip-specific function, health-related quality of life, or level of fitness
Authors: Ho Lucas , Ford Benjamin , Gaston Paul , Clement Nick D.
Published: June 2024

Purpose

The primary aim was to assess whether a total hip arthroplasty (THA) was able to restore health-related quality of life (HRQoL) following an intracapsular hip fracture. The secondary aims were to assess changes in hip-specific function, fitness/frailty, mortality risk, complications and revision risk, and factors independently associated with these.

Methods

This retrospective cohort study included all patients aged ≥ 50 years admitted with a hip fracture from the emergency department at a single centre during a 42-month period. Patient demographics, perioperative variables, complications, revision, and mortality were collected. Patient-reported outcome measures (PROMs) were assessed at final follow-up.

Results

Among 250 identified patients, 189 (75.6%) were women with a mean age of 70.3 (range 50–94 years). Mean follow-up was 2.3 (SD 1.1) years. The implant and patient survival rates at 2 years were both 95.5% (95% confidence intervals (CI) +/− 2.7). Older age (hazard ratio [HR] 1.22, 95% CI 1.12–1.33, p < 0.001) and male sex (HR 3.33, 95% CI 1.15–10.0, p = 0.026) were independently associated with mortality. There were 19 (7.6%) postoperative complications that included 6 (2.4%) periprosthetic fractures, 5 (2.0%) deep infections, and 8 (3.2%) dislocations, of which 13 underwent revision. Increasing time to theatre (HR 1.02, 95% CI 1.01–1.03, p = 0.017) was independently associated with a postoperative complication. Postoperative PROMs were available for 166 (66.4%) patients. There were significant (p < 0.001) deteriorations in EuroQol-5D (Mean difference [MD] 0.192, 95% CI 0.133–0.252), Oxford hip score (MD 2.5, 95% CI 1.5–3.6), and fitness (Rockwood score MD 0.7, 95% CI 0.5–0.8) relative to preoperative levels of function.

Conclusion

THA may be the treatment of choice in a physically active patient with the aim of restoring their HRQoL, hip function, and fitness, but this was not observed. Furthermore, there was a high complication rate which was associated with increasing time to theatre.

Level of evidence

III, retrospective cohort study.
Cost analysis of open versus robot-assisted ventral hernia repair – a retrospective cohort study
Authors: Henriksen Nadia A. , Marckmann Mads , Christoffersen Mette Willaume , Jensen Kristian K.
Published: June 2024

Background

Robot-assisted ventral hernia repair is associated with decreased length of stay and lower complication rates compared with open repair, but acquisition and maintenance of the robotic system is costly. The aim of this was study was to compare the procedure-specific cost of robot-assisted and open ventral and incisional hernia repair including cost of procedure-related readmissions and reoperations within 90 days postoperatively.

Methods

Single-center retrospective cohort study of 100 patients undergoing robot-assisted ventral hernia. Patients were propensity-score matched 1:1 with 100 patients undergoing open repairs on age, type of hernia (primary/incisional), and horizontal defect size. The primary outcome of the study was the total cost per procedure in Euros including the cost of a robotic approach, extra ports, mesh, tackers, length of stay, length of readmission, and operative reintervention. The cost of the robot itself was not included in the cost calculation.

Results

The mean length of stay was 0.3 days for patients undergoing robot-assisted ventral hernia repair, which was significantly shorter compared with 2.1 days for patients undergoing open repair, P < 0.005. The readmission rate was 4% for patients undergoing robot-assisted ventral hernia repairs and was significantly lower compared with open repairs (17%), P = 0.006. The mean total cost of all robot-assisted ventral and incisional hernia repairs was 1,094 euro compared with 1,483 euro for open repairs, P = 0.123. The total cost of a robot-assisted incisional hernia repair was significantly lower (1,134 euros) compared with open ventral hernia repair (2,169 euros), P = 0.005.

Conclusions

In a Danish cohort of patients with incisional hernia, robot-assisted incisional hernia repair was more cost-effective than an open repair due to shortened length of stay, and lower rates of readmission and reintervention within 90 days.
Marginality in the berry fields: hierarchical ordering of food and agrarian systems in Norway
Authors: Juskaite Greta
Published: June 2024

Although being essential to sustaining food production, migrant workers continuously find themselves at the bottom of the social and power hierarchy in food and agrarian systems around the world. Effects and origins of hierarchical ordering in food and agrarian systems increasingly gather public, political, and academic attention, however, how it matters for these systems remains little understood. As such, this paper aims to understand how hierarchical ordering shapes migrant worker marginality and links it to the contemporary formations of food and agrarian systems. To do so, this paper explores engaged and embodied dimensions of disadvantaged migrant worker realities. This is done by drawing on research conducted in Norway, mainly consisting of interviews with migrant agri-food worker and farmers, as well as ethnographic data from Norwegian berry farms and supporting document analysis. The analysis reveals a complex picture of the power and reach of hierarchical ordering as it directly and indirectly impacts migrant workers in the Norwegian berry fields, as well as ideas around narrow divisions in food and agrarian systems and society more broadly that are implicated in naturalizing and internalizing such ordering. Following these insights, the paper proposes a theorization of food and agrarian systems as hierarchical projects– structures that find their foundations in patterned ordering that arranges and regularizes power hierarchies on the count of differences.
Forward–reverse blockchain traceability: promoting electric vehicles with battery recycling in the presence of subsidy
Authors: Li Jizi , Liu Fangbing , Zhang Justin Z. , Li Longyu , Ferreira João
Published: June 2024

Electric vehicles (EVs) and their battery recycling have recently garnered heightened attention from both firms and consumers, primarily driven by concerns related to environmental sustainability. However, consumers often grapple with uncertainties regarding the green valuation of EVs. Integrating blockchain traceability technology presents a promising solution to mitigate these ambiguities by providing traceable, immutable, and precise information. Within this context, this research, grounded in a game-theoretical framework, delves into the strategies involving blockchain traceability in the pre-purchase and post-purchase stages of EVs. Specifically, the paper analytically studies the influence of three distinct strategies, namely, non-blockchain traceability, forward blockchain traceability, and Forward–reverse blockchain traceability, on the willingness of EV manufacturers to adopt blockchain technology. In addition, the study incorporates two prevalent government subsidies to scrutinize and contrast their implications on optimal outcomes. The findings of this study uncover the nuanced relationship between adopting blockchain traceability and its impact on EV sales. Notably, the research shows that the positive impact on consumers’ surplus from blockchain adoption depends on the cost coefficient of green low-carbon levels not exceeding a particular threshold. Moreover, regarding the use of government subsidies to enhance overall social welfare, it is shown that the forward blockchain traceability strategy should align with consumer-oriented subsidies and the Forward–reverse blockchain traceability strategy with EV maker-oriented subsidies.