bluuebunny/crossref_metadata_2025 huggingface dataset:
Population-based estimation for PDE system – Applications in electroporation of tumor spheroids
Authors: Collin Annabelle
Published: March 2024

The estimation of partial differential systems (PDE) – in particular, the identification of their parameters – is fundamental in many applications to combine modeling and available measurements. However, it is well known that parameter prior values must be chosen appropriately to balance our distrust of measurements, especially when data are sparse or corrupted by noise. A classic strategy to compensate for this weakness is to use repeated measurements collected in configurations with common priors, such as multiple subjects in a clinical trial. In the mixed-effects approach, all subjects are pooled and a global distribution of model parameters in the population is estimated. However, due to the high computational cost, this strategy is often not applicable in practice for PDE. In this paper, we propose an estimation strategy to overcome this challenge. This sophisticated method is based on two important existing methodological strategies: (1) a population-based Kalman filter and, (2) a joint state-parameter estimation. More precisely, the errors coming from the initial conditions are controlled by a Luenberger observer and the parameters are estimated using a population-based reduced-order Kalman filter restricted to the parameter space. The performance of the algorithm is evaluated using synthetic and real data for tumor spheroid electroporation.
Experimental Investigation of Al-6061 Metal Matrix Composite Reinforced with Selenium
Authors: Tirumala Sri Harsha Kandala , Kavili Sai Sujith , Manubolu Venugopal Naidu , V Diwakar Reddy
Published: March 2024

The creation of innovative materials with essential properties is required due to the industry’s rapid advancements. The most desirable properties of metals used in the aerospace industry, automotive industry, and marine industry are hardness, compression, shear, etc. Aluminium metal matrix composites (AMMCs) are effective and meet industrial standards. This study focuses on the influence of reinforcement particles (Selenium) on Al-6061 by using the stir-casting fabrication method and the composites are prepared. Mechanical characteristics are studied by varying Selenium weight percentages such as 0.5%, 1%, and 1.5%. Based on the Mechanical tests it is noticed that there is an improvement in Mechanical strength such as tensile strength, flexural strength, and compression strength by 32%, 29.5%, and 25% at 1 Wt% of Selenium. By implying the Powder XRD test on the prepared sample which is a significant parameter drawn from mechanical tests, based on the Standard XRD data it is noticed that a Hexagonal Crystal Structure is formed.
Fabrication and Characterization of a Stir Casting-Based Aluminium Hybrid MMC Reinforced with SiC, TiC, and MoS2
Authors: Arun M. , Ragupathy K. , Anand T. , Vishvanathperumal S.
Published: March 2024

The need for strong, lightweight materials has prompted the creation of innovative metal matrix composites based on aluminum. The properties of metal matrix composites that are uniformly dispersed with nanoparticles are much superior to those of monolithic alloy and microparticle-reinforced composites. The objective of this work was to create and evaluate a metal matrix composite reinforced with MoS2, SiC, and TiC that is a hybrid aluminum alloy, Al6061. It was also investigated how the weight percentages (3, 6, 9, and 12%) of MoS2, SiC, and TiC reinforcement affected the mechanical, morphological, tribological, and physical characteristics of the metal matrix composite. The addition of SiC and MoS2 increased the density of the reinforced Al6061 composite when compared to as-cast non-reinforced Al6061. It was found that the hybrid composite Al6061/12% SiC/4% MoS2 had the maximum density. The hybrid metal matrix composite's toughness increased as the proportion of TiC weight increased. The composite made of Al6061, 12% TiC, and 4% MoS2 had the maximum hardness, measuring 114.03 HV. The composite Al6061/12% TiC/4% MoS2 has the most ultimate tensile strength. The tribology analysis revealed that when applied stress increased from 10 to 50 N, mass loss increased dramatically. Because of the solid MoS2 lubricant and the development of the TiC layer at the contact zone, Double- and triple-reinforced specimens had less wear loss than non-reinforced specimens, as shown by the wear performance of hybrid composites. The main wear mechanisms of the composites were delamination wear and wear debris.
Numerical Study on the Effect of Spinning for 7.62 APM2 Projectile Impacting on Al 7075-T651 Target
Authors: Pranay Vaggu , Panigrahi S.K.
Published: March 2024

When a projectile launches from a rifled barrel, it undergoes rotation around its longitudinal axis, commonly referred to as spinning, to maintain stability during its flight through the air. Upon reaching the target, the projectile possesses both rotational and translational energies. This study examines the impact of rotational energy on the penetration of 7.62 APM2 projectiles by using Finite Element Analysis(FEA). Al 7075-T651 alloy with a thickness of 20mm is considered as target material. Initially, the model is validated using the experimental results available in the literature. The validated model has been extended to study the effect of the projectile’s spinning by using the Recht-Ipson parameters. Based on the results, it is observed that the rotation of the projectile leads to an enhancement in penetrating energy and a reduction in ballistic limit velocity.
Machine Learning-Driven Wind Energy Forecasting for Sustainable Development
Authors: T Magesh , F Samuel Franklin , S Santhi P. , M Thiyagesan
Published: March 2024

The growing need for energy, in addition to the depletion of fossil fuel supply, has underlined the importance of renewable energy for long-term growth. Renewable energy stands out among these, but its broad usage is hampered by the inherent uncertainty of wind power generation. This study uses machine learning to predict wind energy yield. Several regression models were used, including decision tree regression, linear regression, and random forest regression. The results emphasize the random forest regression, which has a high R-squared score, suggesting strong predictive ability. The paper also contains wind power output projections, which provide insights for optimal wind energy planning and usage. Overall, this attempt gives vital insights to improving the effective use of renewable energy, advancing the cause of sustainable development.
Numerical investigation on the effect of stroke plane inclination on the aerodynamic performance of dragonfly take-off flight
Authors: Tiwari Shubham , Madan Sejal , Chandel Sunil
Published: March 2024

A numerical investigation is carried out to study the role of inclined stroke plane on the aerodynamic performance of a dragonfly during a take-off flight. A two-dimensional numerical simulation of tandem foils oscillating in-phase along an inclined stroke plane at Re = 160 is performed using ANSYS Fluent. The stroke plane angle is varied from 10° ≤ β ≤ 80° to determine its effect on aerodynamic force coefficients of forefoil and hindfoil. The result shows that the presence of forefoil reduces the hindfoil Cv for low stroke plane angle cases. The cycle-average vertical force coefficient Cv of both foils increases with β up to 50° and then decreases. A vortex pair is present in the wake of the foils during each cycle, which induces a downward dipole jet. The dipole jet characteristics such as jet width, location and maximum velocity components are measured for each stroke plane angle. It is observed that the cause of variation in Cv and CH with stroke plane angle can be explained with the help of dipole jet characteristics.
A Robotic Exoskeleton Assistive Device: Design and Kinematic Analysis of a Hand Exoskeleton for Assistance
Authors: Dhal Arpeet , Majhi Durgeshwar , Rout Ashish Kumar , S. Soumya
Published: March 2024

Addressing the challenges faced by individuals with motor disabilities, which impedes ease in movement, coordination, or sensation, a low-weight hand exoskeleton was developed considering accessibility, low cost, adaptability, and mass manufacturing to overcome the impact of hand functioning disorders on people's physical and social well-being. In this paper, a 12-DOF Hand exoskeleton consisting of a 6-DOF Arm and 6-DOF finger exoskeleton was designed and later its kinematic analysis was performed. By taking into consideration the constraints provided by the exoskeleton to human hand motion, the Forward kinematics, using Denavit- Hartenberg (D-H) parameters were conducted to determine its workspace.
Nach der Pandemie ist vor der Pandemie: Und wie interdisziplinäre Forschung hier helfen kann
Authors: Ly Yen-Tran , Arndt Franca , Boschert Alessa L. , Pavletić Bruno , Webner Florian , Kohl Andreas , Grübbel Henrik , Soltau Julian , Talai Iman , Diallo Mohamed Diaoulé , Westhoff Andreas , Schreiber Andreas , Hecking Tobias , Duschek Frank , Grünewald Karin , Meller Frank , Biedermann Jörn , Rinderknecht Frank , Kraft Werner , Schmeling Daniel , Jordan Jens , Moeller Ralf
Published: March 2024

Die Luftfahrt gehört zu den am stärksten durch die COVID-19-Pandemie beeinträchtigten gesellschaftlichen Bereiche und hat gleichzeitig zu einer raschen globalen Ausbreitung des SARS-CoV-2-Virus beigetragen. SARS-CoV-2 gehört zu den Coronaviren, die schon in der Vergangenheit zu Ausbrüchen wie MERS-CoV geführt haben. Diese Erregergruppe sowie weitere zum aktuellen Zeitpunkt möglicherweise noch unbekannte Erreger werden auch in Zukunft unsere Gesellschaft herausfordern. Um hier besser reagieren zu können, wurde am DLR unter Kooperation von 6 Instituten ein Graduiertenkolleg ins Leben gerufen, das interdisziplinäre Lösungsansätze zur Erforschung und Bekämpfung von aktuellen und zukünftigen Pandemien entwickeln wird. Dabei arbeiten Ingenieure, Physiker, Softwareentwickler, Biologen und Mediziner in enger Zusammenarbeit an neuen Konzepten und dem Aufbau fachgebietsübergreifenden Wissens, um zukünftige Pandemien besser kontrollieren und eindämmen zu können sowie gezielter reagieren zu können. Ein Schwerpunkt ist hierbei die Reduzierung der Keimbelastung in Flugzeugen aber auch anderen öffentlichen Verkehrsmitteln wie Bussen und Bahnen. In dieser Übersichtsarbeit geben wir einen Überblick über die Ausgangslage und mögliche Ansätze, um künftigen pandemischen Herausforderungen begegnen zu können.
The Adrenal Gland and Pancreatic Islets – A Beneficial Endocrine
Alliance
Authors: Schubert Undine , Lehmann Susann , Schmid Janine , Morawietz Henning , Bornstein Stefan R. , Ludwig Barbara
Published: March 2024

Intraportal islet transplantation in patients with type 1 diabetes enables
restoration of glucose-regulated insulin secretion. However, several factors
hamper a widespread application and long-term success: chronic hypoxia, an
inappropriate microenvironment and suppression of regenerative and proliferative
potential by high local levels of immunosuppressive agents. Therefore, the
identification of alternative and superior transplant sites is of major
scientific and clinical interest. Here, we aim to evaluate the adrenal as an
alternative transplantation site. The adrenal features a particular
microenvironment with extensive vascularization, anti-apoptotic and
pro-proliferative, anti-inflammatory and immunosuppressive effects. To validate
this novel transplantation site, an in vitro co-culture system of adrenal cells
and pancreatic islets was established and viability, islet survival, functional
potency and antioxidative defense capacity were evaluated. For in vivo
validation, an immune-deficient diabetic mouse model for intra-adrenal islet
transplantation was applied. The functional capacity of intra-adrenally grafted
islets to reverse diabetes was compared to a standard islet transplant model and
measures of engraftment such as vascular integration were evaluated. The
presence of adrenal cells positively impacted on cell metabolism and oxidative
stress. Following transplantation, we could demonstrate enhanced islet function
in comparison to standard models with improved engraftment and superior
re-vascularization. This experimental approach allows for novel insights into
the interaction of endocrine systems and may open up novel strategies for islet
transplantation augmented through the bystander effect of other endocrine cells
or the active factors secreted by adrenal cells modulating the
microenvironment.
Association of VEGF+936 C/T Polymorphism with Susceptibility to Type
2 Diabetic Retinopathy: A Meta-Analysis
Authors: Huo Yanhong , Zhang Xin , Su Li , Zhang Yan
Published: March 2024

The objective of this study is to explore the relationship between the vascular
endothelial growth factor (VEGF)+936 C/T polymorphism and the risk of type 2
diabetic retinopathy (T2DR) by a method of meta-analysis. Six online databases
were queried to identify studies investigating the VEGF+936 C/T polymorphism
that influenced T2DR up to August 2023. The statistical tool of the pooled data
was adopted using Stata 15.0 software. The experimental group comprised patients
with T2DR, while patients with type 2 diabetes mellitus without retinopathy were
considered as the controls. The odds ratio (OR) was utilized as effect size.
Eight eligible publications were identified in this review, including 1546
patients with T2DR. The combined results revealed that the VEGF+936 C/T
polymorphism was significantly associated with the T2DR risk under the allelic
(C/T: OR=0.54, p<0.001), the dominant (CC+CT/TT: OR=0.37, p<0.001),
recessive (CC/CT+TT: OR=0.52, p=0.001), homozygous (CC/TT: OR=0.31, p<0.001),
and heterozygous (CT/TT: OR=0.55, p=0.005) gene models. No significant
correlation was observed regarding the VEGF+936 C/T polymorphism that
contributed to the risk of proliferative diabetic retinopathy (PDR) versus
non-PDR. In conclusion, the VEGF+936 C/T polymorphism significantly contributed
to the T2DR risk. Specifically, at the VEGF+936 C/T locus, the presence of
allele C and genotypes CC, CT, and CC+CT were found to be associated with a
reduced risk of T2DR.
Characterizing the Impact of Facial Rehabilitation on Acute Facial Paralysis
Authors: Abend Audrey , Perillo Lauren , DeSimone Jenna , Eytan Danielle F.
Published: March 2024

Evidence on facial rehabilitation therapy (FRT) for acute facial paralysis (FP) remains limited. We present a retrospective review of patients with acute FP who have received FRT with physical therapists within 1 year of FP onset as determined by Sunnybrook Facial Grading Scale (SFGS) composite scores. A total of 702 patients with a clinical diagnosis of FP were referred to a university rehabilitation program between January 1, 2015 and January 1, 2022. Seventy-six patients met the criteria, defined as FP diagnosis <12 months before FRT initiation, ≥3 therapy sessions, and sufficient follow-up data. Average number of treatment sessions between SFGS scores was 7.7. History of cancer, sex, number of treatment sessions, and initial SFGS score were correlated with change in SFGS. Time to treatment was not correlated with change in SFGS score. SFGS improved with each additional treatment session (p < 0.01). Each additional point in the initial SFGS was correlated with less change in the final SFGS score (p < 0.01). FRT can provide meaningful improvement in functionality for patients with acute FP, regardless of time to treatment. Furthermore, patients who present with poorer functionality at baseline and those who undergo more treatment are most likely to see SFGS improvement. Research comparing the effect of facial rehabilitation with other treatment modalities and to a control cohort is warranted.
Oral Health Literacy Rate Among Schoolteachers—A Quantitative Study
Authors: Ain Qurat-ul , Gillani Syeda Munazza , Ain Qurat-ul
Published: March 2024

Objective The aim of this study was to evaluate oral health literacy (OHL) rate among schoolteachers of Abbottabad city by using structured questionnaire divided in sections of reading skills, numeracy, listening skills, and appropriate decision-making skills.

Materials and Methods Descriptive cross-sectional study was conducted among schoolteachers with survey method. Total 159 participants were selected as sample from 10 different local schools of Abbottabad city. Data was gathered by using OHL-AQ (oral health literacy-adult questionnaire) with convenient sampling technique. Responses were calculated by using IBM SPSS.V.26 and descriptive analyses were performed.

Results Satisfactory results were seen among schoolteachers: high-level of OHL, 44.65%; moderate level of OHL, 40.9 and low-level OHL, 14.46%. The questionnaire section, “numeracy-calculation skills” and “appropriate decision-making skills,” exhibited high scores.

Conclusion This study concluded that the OHL rate among schoolteachers was satisfactory. But as teachers play a pivotal role in shaping and influencing young minds, setting a goal of achieving 100% would ensure commitment toward better oral health of their wards. Those participants who showed considerably low OHL level is alarming for oral health challenges.
Detection of doxycycline by using a tapered droplet structure fiber sensor
Authors: Yang Zhitao , Wang Shan , Wang Shijie , Han Sijia , Wei Lingzui , Yang Wenlong
Published: March 2024

The abuse of doxycycline (DC) can lead to residues in animals and water environments, which severely threaten human health; however, currently accepted detection methods are generally complicated and cannot be used for real-time detection. Therefore, developing a method for rapid real-time detection of DC microcontent residues is highly important. Herein, based on the Mach–Zehnder interference, we propose a simple tapered droplet structure fiber sensor with a high detection sensitivity. By modifying the sensing region with a molecularly imprinted polymer film of DC, this sensor realizes the specific detection of DC and has a detection sensitivity of 58.81 pm/ppm for DC in a large concentration range of 0–300 ppm. This sensor can be used to detect DC microcontent in aqueous solutions in real time.
An experimental investigation on the ice-breaking phenomenon induced by the spark-generated bubble near a vertical plate
Authors: Dong Qianqian , Chen Qiyang , Xiong Chengwang , Wang Shiping
Published: March 2024

The present work experimentally studied the coupled interaction between the fracture of an ice plate floating on the water surface, induced by the pulsation of a high-pressure bubble, and the associated deformation of a vertically submerged aluminum plate. The dynamic behaviors of bubbles and fractured ice were concurrently recorded using two high-speed cameras, and the plastic deformation of the aluminum plate was measured by an ultra-depth three-dimensional microscope. The results indicated that the jet direction of the collapsed bubble is heavily influenced by the position to generate the bubble due to the competing Bjerknes forces caused by various boundaries. There is also a significant discrepancy in the phenomena of bubble collapse near thin vs thick ice plates, attributed to the sudden alteration in boundary conditions caused by ice fracturing. Three distinct ice-breaking mechanisms, namely, the hogging moment, jet impact, and the secondary shock wave, were identified based on the types of loads, leading to the initial ice fractures. In general, it was observed that the efficiency of ice breaking improved with a decrease in the bubble–ice distance (γf) and an increase in the bubble–plate distance (γm). It was found that the contacting jet from an upwardly collapsed bubble is the most effective in breaking the thickest ice plates for γm>1.9. While the shock wave from a bubble collapsing near solid wall corners could fracture thick ice plates, the aluminum plate risked damage from jet impacts when γm was less than 0.6.
Analytical solution for the submerged free jet
Authors: Oved Avishai , Haustein Herman D.
Published: March 2024

Laminar submerged free jet theory still falls short in the near-nozzle region and transition to Schlichting's self-similar jet. The author's recent solution, based on mass conservation, is found lacking beyond the near-nozzle jet-core region. Instead, it is here constrained to conserve momentum, resulting in a locally linearized convection-diffusion equation, valid over jet width and up to self-similarity, when compared to simulations. This new solution leads to profile-specific values of virtual-origin correction to Schlichting's solution. Additionally, extensive jet characteristics are examined: (1) curvature core, (2) radial inflection location, (3) radial velocity, (4) vorticity field, (5) issuing mass, and (6) jet width. All are well predicted, and new insights are gained for a variety of issuing profiles: from uniform, through a non-monotonous profile and up to fully developed. The issuing mass of all non-uniform profiles undergoes an initial contraction proportional to the profile's level of development. Interestingly, the submerged jet contracts identically to the free-surface jet in the very near-nozzle region, before significant influence of their differing boundary conditions. Moreover, unless the issuing profile contains a radial inflection point, the inflection always occurs in the entrained fluid, just beyond the bounds of the issuing mass. It also follows an initial contraction and only later a widening toward the self-similar trend. Despite this contraction, the entrained fluid causes monotonous total jet-widening, at a rate inversely proportional to the level of development. Finally, this new solution correctly captures additional jet features, such as the local radial velocity and decay of the primary vorticity.
Ion trap with in-vacuum high numerical aperture imaging for a dual-species modular quantum computer
Authors: Carter Allison L. , O’Reilly Jameson , Toh George , Saha Sagnik , Shalaev Mikhail , Goetting Isabella , Monroe Christopher
Published: March 2024

Photonic interconnects between quantum systems will play a central role in both scalable quantum computing and quantum networking. Entanglement of remote qubits via photons has been demonstrated in many platforms; however, improving the rate of entanglement generation will be instrumental for integrating photonic links into modular quantum computers. We present an ion trap system that has the highest reported free-space photon collection efficiency for quantum networking. We use a pair of in-vacuum aspheric lenses, each with a numerical aperture of 0.8, to couple 10(1)% of the 493 nm photons emitted from a 138Ba+ ion into single-mode fibers. We also demonstrate that proximal effects of the lenses on the ion position and motion can be mitigated.
Stability of low-pressure turbine boundary layers under variable Reynolds number and pressure gradient
Authors: Dotto Alessandro , Luzzi Matteo , Verdoya Jacopo , Simoni Daniele , Hanifi Ardeshir , Pralits Jan Oscar
Published: March 2024

The free-stream turbulence induced transition occurring under typical low-pressure turbine flow conditions is investigated by comparing linear stability theory with wind tunnel measurements acquired over a flat plate subjected to high turbulence intensity. The analysis was carried out, accounting for three different Reynolds numbers and four different adverse pressure gradients. First, a non-similarity-based boundary layer (BL) solver was used to compute base flows and validated against pressure taps and particle image velocimetry (PIV) measurements. Successively, the optimal disturbances and their spatial transient growth were calculated by coupling classical linear stability theory and a direct-adjoint optimization procedure on all flow conditions considered. Linear stability results were compared with experimental particle image velocimetry measurements on both wall-normal and wall-parallel planes. Finally, the sensitivity of the disturbance spatial transient growth to the spanwise wavenumber of perturbations, the receptivity position, and the location where disturbance energy is maximized were investigated via the built numerical model. Overall, the optimal perturbations computed by linear stability theory show good agreement with the streaky structures surveyed in experiments. Interestingly, the energy growth of disturbances was found to be maximum for all the flow conditions examined, when perturbations entered the boundary layer close to the position where minimum pressure occurs.
Low divergence cold-wall oven for loading ion traps
Authors: Prakash Anand , Ayyadevara Akhil , Krishnakumar E. , Rangwala S. A.
Published: March 2024

We present a compact cold-wall oven that is simple to build and align for loading miniature ion traps with calcium ions. The cold-wall oven, which is a metal-loaded capillary heated only through a portion of its length by the passage of a current, is described and characterized. An atomic beam with a low divergence of 14 mrad is produced. We perform Doppler-sensitive, resonant fluorescence measurements on the atomic beam to characterize the oven’s performance. The emission of atoms from the oven is seen within ∼70 s after turning on the oven at an electric power consumption of <10 W. The flow rate is measured to be 1.5 ± 0.2 × 109 atoms s−1 at a temperature of 702 ± 7 K. The entire oven assembly is mounted on a CF16 feedthrough. This design can be extended to other species for producing a collimated atomic beam.
Flow dynamics of a liquid–liquid bi-swirl injector
Authors: Natarajan Vishnu , Unnikrishnan Umesh , Choi Jeong-Yeol , Yang Vigor
Published: March 2024

This work presents detailed two-phase flow simulations of liquid–liquid bi-swirl injectors for engineering applications. Liquid oxygen and kerosene are delivered into the injector, which is initially filled with air. A parametric study is conducted on the recess length of the inner tube to investigate its effect on the flow dynamics and spray pattern. The simulations are performed using an improved multiphase flow solver in OpenFOAM, which employs the volume-of-fluid approach for interface tracking and the large-eddy simulation technique for turbulence modeling. Detailed flow dynamics of both fuel and oxidizer, along with their spray patterns, are examined systematically. A comprehensive account is provided on the impact of the recess length on flow evolution, including the film thickness, air core diameter, and spray cone angle. Spectral and dynamic mode decomposition analyses are performed to further examine the flow structures and dynamics. Results from this study can be effectively used to facilitate the design optimization of injectors for liquid-fueled propulsion systems.
Dielectrophoretic–inertial microfluidics for Symbiodinium separation and enrichment
Authors: Zhou Teng , He Jixin , Wu Zhihao , Bian Qin , He Xiaohan , Zhou Shizheng , Zhao Juncheng , Wu Tao , Shi Liuyong , Yan Hong
Published: March 2024

In the marine environment, the symbiotic relationship between Symbiodinium and corals plays a pivotal role in coral growth and development. Against the backdrop of widespread coral bleaching due to the global climate change, the facile and efficient separation and enrichment of different strains of Symbiodinium hold significant importance for studying coral bleaching. This paper aims to report a platform that integrates dielectrophoretic and inertial forces for the separation and enrichment of Symbiodinium, comprising two modular components: a separation module and an enrichment module. Within the separation module, distinct strains of Symbiodinium undergo preliminary stratification in a contraction–expansion microchannel under the influence of inertial forces. Dielectrophoretic forces generated by the indium tin oxide electrodes divert them toward different outlets, achieving separation. In the enrichment module, the Symbiodinium collected from outlets is rapidly focused through a contraction–expansion microchannel and high-purity samples are concentrated through a single outlet. Evaluating separation efficiency is based on the purity of collected Symbiodinium at the outlet under three different flow rates: 13, 16, and 19 μl/min, while the concentration of enriched Symbiodinium at 100, 200, 300, and 400 μl/min flow rates evaluates the effectiveness of the enrichment process. The experimental results demonstrate a separation purity of approximately 90% and an enrichment factor of around 5.5. The platform holds promise for further applications in the selection and targeted enrichment of high-quality coral symbiotic algae, providing essential research foundations for the conservation of coral ecosystems.
Enhancing numerical accuracy in the prediction of rotor wake vortex structures
Authors: Bodling Andrew , Schwarz Clemens , Wolf C. Christian , Gardner Anthony D.
Published: March 2024

In modern high-fidelity computational fluid dynamic simulations, the primary vortex system in hover often breaks down into secondary vortices. The sources of numerical error influencing the prediction of the vortex system were studied by performing high-fidelity simulations of the wake of a two-bladed rotor and comparing the predictions to stereoscopic particle image velocimetry measurements in different measurement planes. Various numerical inputs, including sub-iteration convergence, blade pitch offset, and grid resolution, were varied to resolve discrepancies between the measured and predicted vortex characteristics from a previous study done by the authors. A parametric study on near- and off-body solver sub-iteration convergence demonstrated that although the secondary vortex characteristics converged as the sub-iteration convergence of both solvers increased, a large discrepancy in the number of secondary vortices remained. This discrepancy was investigated by varying the thrust, where it was found that the breakdown of the primary vortex is directly linked to the number of secondary vortices. Dissimilarities in the blade pitch angle, which could not be avoided in the experiment, were modeled by intentionally using an offset in the blade pitch angle of the two blades. It was shown that as blade pitch angle offset increases, vortex pairing becomes more distinct. When vortex pairing occurred in both the experiment and simulation, the decay of secondary vortices in the experiment and simulation agreed best. To better match the experimental resolution, grid resolution was increased and comparing the two simulations, the finer mesh simulation agreed best with the measured primary and secondary vortex characteristics.
Balance and imbalance in biogeochemical cycles reflect the operation of closed, exchange, and open sets
Authors: Kemeny Preston Cosslett , Torres Mark A. , Fischer Woodward W. , Blättler Clara L.
Published: March 2024

Biogeochemical reactions modulate the chemical composition of the oceans and atmosphere, providing feedbacks that sustain planetary habitability over geological time. Here, we mathematically evaluate a suite of biogeochemical processes to identify combinations of reactions that stabilize atmospheric carbon dioxide by balancing fluxes of chemical species among the ocean, atmosphere, and geosphere. Unlike prior modeling efforts, this approach does not prescribe functional relationships between the rates of biogeochemical processes and environmental conditions. Our agnostic framework generates three types of stable reaction combinations: closed sets, where sources and sinks mutually cancel for all chemical reservoirs; exchange sets, where constant ocean–atmosphere conditions are maintained through the growth or destruction of crustal reservoirs; and open sets, where balance in alkalinity and carbon fluxes is accommodated by changes in other chemical components of seawater or the atmosphere. These three modes of operation have different characteristic timescales and may leave distinct evidence in the rock record. To provide a practical example of this theoretical framework, we applied the model to recast existing hypotheses for Cenozoic climate change based on feedbacks or shared forcing mechanisms. Overall, this work provides a systematic and simplified conceptual framework for understanding the function and evolution of global biogeochemical cycles.
SNARE chaperone Sly1 directly mediates close-range vesicle tethering
Authors: Duan Mengtong , Plemel Rachael L. , Takenaka Tomoka , Lin Ariel , Delgado Beatriz Marie , Nattermann Una , Nickerson Daniel P. , Mima Joji , Miller Elizabeth A. , Merz Alexey J.
Published: March 2024

The essential Golgi protein Sly1 is a member of the Sec1/mammalian Unc-18 (SM) family of SNARE chaperones. Sly1 was originally identified through remarkable gain-of-function alleles that bypass requirements for diverse vesicle tethering factors. Employing genetic analyses and chemically defined reconstitutions of ER–Golgi fusion, we discovered that a loop conserved among Sly1 family members is not only autoinhibitory but also acts as a positive effector. An amphipathic lipid packing sensor (ALPS)-like helix within the loop directly binds high-curvature membranes. Membrane binding is required for relief of Sly1 autoinhibition and also allows Sly1 to directly tether incoming vesicles to the Qa-SNARE on the target organelle. The SLY1-20 mutation bypasses requirements for diverse tethering factors but loses this ability if the tethering activity is impaired. We propose that long-range tethers, including Golgins and multisubunit tethering complexes, hand off vesicles to Sly1, which then tethers at close range to initiate trans-SNARE complex assembly and fusion in the early secretory pathway.
DPM1 modulates desmosomal adhesion and epidermal differentiation through SERPINB5
Authors: Rathod Maitreyi , Franz Henriette , Beyersdorfer Vivien , Wanuske Marie-Therès , Leal-Fischer Karen , Hanns Pauline , Stüdle Chiara , Zimmermann Aude , Buczak Katarzyna , Schinner Camilla , Spindler Volker
Published: March 2024

Glycosylation is essential to facilitate cell–cell adhesion and differentiation. We determined the role of the dolichol phosphate mannosyltransferase (DPM) complex, a central regulator for glycosylation, for desmosomal adhesive function and epidermal differentiation. Deletion of the key molecule of the DPM complex, DPM1, in human keratinocytes resulted in weakened cell–cell adhesion, impaired localization of the desmosomal components desmoplakin and desmoglein-2, and led to cytoskeletal organization defects in human keratinocytes. In a 3D organotypic human epidermis model, loss of DPM1 caused impaired differentiation with abnormally increased cornification, reduced thickness of non-corneal layers, and formation of intercellular gaps in the epidermis. Using proteomic approaches, SERPINB5 was identified as a DPM1-dependent interaction partner of desmoplakin. Mechanistically, SERPINB5 reduced desmoplakin phosphorylation at serine 176, which was required for strong intercellular adhesion. These results uncover a novel role of the DPM complex in connecting desmosomal adhesion with epidermal differentiation.
N-cadherin dynamically regulates pediatric glioma cell migration in complex environments
Authors: Kim Dayoung , Olson James M. , Cooper Jonathan A.
Published: March 2024

Pediatric high-grade gliomas are highly invasive and essentially incurable. Glioma cells migrate between neurons and glia, along axon tracts, and through extracellular matrix surrounding blood vessels and underlying the pia. Mechanisms that allow adaptation to such complex environments are poorly understood. N-cadherin is highly expressed in pediatric gliomas and associated with shorter survival. We found that intercellular homotypic N-cadherin interactions differentially regulate glioma migration according to the microenvironment, stimulating migration on cultured neurons or astrocytes but inhibiting invasion into reconstituted or astrocyte-deposited extracellular matrix. N-cadherin localizes to filamentous connections between migrating leader cells but to epithelial-like junctions between followers. Leader cells have more surface and recycling N-cadherin, increased YAP1/TAZ signaling, and increased proliferation relative to followers. YAP1/TAZ signaling is dynamically regulated as leaders and followers change position, leading to altered N-cadherin levels and organization. Together, the results suggest that pediatric glioma cells adapt to different microenvironments by regulating N-cadherin dynamics and cell–cell contacts.
Broken chromosomes heading into mitosis: More than one way to patch a flat tire
Authors: Messer C. Luke , Fox Donald T.
Published: March 2024

A cell dealing with a broken chromosome in mitosis is like a driver dealing with a flat tire on the highway: damage repair must occur under non-ideal circumstances. Mitotic chromosome breaks encounter problems related to structures called micronuclei. These aberrant nuclei are linked to cell death, mutagenesis, and cancer. In the last few years, a flurry of studies illuminated two mechanisms that prevent mitotic problems related to micronuclei. One mechanism prevents micronuclei from forming during mitosis and involves DNA Polymerase Theta, a DNA repair regulator that patches up broken mitotic chromosomes. A second mechanism is activated after micronuclei form and then rupture, and involves CIP2A and TOPBP1 proteins, which patch micronuclear fragments to promote their subsequent mitotic segregation. Here, we review recent progress in this field of mitotic DNA damage and discuss why multiple mechanisms exist. Future studies in this exciting area will reveal new DNA break responses and inform therapeutic strategies.
Laura Feltri: Of Schwann cells, matrix, and family
Authors: Previtali Stefano C. , Taveggia Carla
Published: March 2024

Laura Feltri (1963–2023) has been a pioneer in the study of extracellular matrix in peripheral nervous system myelination.
Xiaoyu Hu: Let the data guide you
Authors: Van Emmenis Lucie
Published: March 2024

Xiaoyu Hu is a professor and director of the Institute for Immunology at Tsinghua University. Her lab is interested in understanding the molecular mechanisms underlying the transcriptional, translational, and metabolic mechanisms of the key cell types involved in host defense and inflammatory responses: macrophages and intestinal epithelial cells (IECs). We recently spoke with Xiaoyu about her current work, the benefits of a multidisciplinary team, and how being part of journal editorial boards brings her intellectual stimulation and inspiration for her own lab.
SIM.T-K9.3: Standard platinum resistance thermometer ITS-90 realizations from the Hg triple point to the Zn freezing point
Authors: Quelhas Klaus N , Lozano Bruno M , Hamilton Francis
Published: March 2024

Main text

This report shows the results of a bilateral comparison of temperature standards between Instituto Nacional de Metrologia, Qualidade e Tecnologia (Inmetro, Brazil), and Trinidad and Tobago Bureau of Standards (TTBS, Trinidad and Tobago), carried out between January and July of 2020. The measurands of this comparison were the W(t90) ratios of two Standard Platinum Resistance Thermometers (SPRTs), used as transfer standards, measured at the zinc freezing point (Zn FP, 419.527 °C), tin freezing point (Sn FP, 231.928 °C), gallium melting point (Ga MP, 29.7646 °C), triple point of water (TPW, 0.01 °C) and mercury triple point (Hg TP, -38.8344 °C).

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Controlling of spontaneous emission of quantum dots based on hyperbolic metamaterials
Authors: Mao Yu , Zhang Hao , Xiong Jing , Liu Xiangpeng , Wang Qiaoqiao , Wang Junqiao
Published: March 2024

The study of spontaneous emission has basic and supporting significance for enhancing the interaction between light and matter, solid-state lighting and biosensors. Hyperbolic metamaterials (HMMs) can support high k modes due to their hyperbolic dispersion characteristics, resulting in extremely high photon density, which affects spontaneous emission. Therefore, here we study the effect of HMMs on the spontaneous emission of quantum dots (QDs), and the Purcell factor reaches 20 times. At the same time, the structure of HMMs with gold nanoantennas is studied. The addition of gold nanoantennas further increases the Purcell factor to 120 times. In addition, the effects of the metal filling rate, the position and polarization direction of QDs on spontaneous emission enhancement and radiation power peak position are also studied. This provides a new perspective for enhancing and controlling spontaneous emission of QDs based on HMMs.
Effects of Mn doping on the conduction mechanism and dielectric nonlinearity of Na0.5Bi0.5TiO3 thin film
Authors: Liang Zhongshuai , Shen Cheng-Ao , Wang Jiawei , Liu Xin , Hu Tianyi , Li Chao , Xiong Lilong , Du Xianfeng
Published: March 2024

In this work, the conduction mechanism and dielectric nonlinearity of undoped and Mn-doped Na0.5Bi0.5TiO3 (NBT) films were investigated. The potential conduction mechanism in relatively low electric fields should be dominated by hopping conduction rather than typical Ohmic conduction. In the high electric field region, the conduction mechanism is dominated by Poole–Frenkel emission and Schottky emission. The enhancement of electrical insulation of NBT films after Mn doping was shown to result from a decrease in oxygen vacancies and elevation of the conduction energy barrier. Furthermore, significant improvements in the nonlinearity of both the dielectric constant and polarization of Mn-doped NBT films were observed, as indicated by the results of Rayleigh fitting and first-order reversal curve distributions. Such enhancements were attributed to the reduction in domain wall pinning, decreased interference from electrostatic potential and improved leakage characteristics.
Characterization of tracks from alpha-particles in PADC detectors for passive environmental monitoring of fast neutron radiation field
Authors: Biordi Chantal , Sarchiapone Lucia , Gallo Salvatore
Published: March 2024

Fast neutron dosimetry is particularly crucial in the realm of radioprotection, as it significantly contributes to evaluating the radiation protection measures. This assessment aims to ensure and enhance the effectiveness of implemented safeguards and precautions, thereby minimizing the risks and potential harm associated with radiation exposure. Given the substantial biological damage that fast neutrons can inflict when interacting with living tissues, accurate dosimetry is indispensable for ensuring the safety of personnel in these environments and for optimizing radiation therapy treatments. Employing an indirect detector technique, this research focuses on characterizing the geometrical and optical properties of tracks produced by alpha particles resulting from boron-neutron reactions and distinguish them from the background made up of tracks generated from radon decay and impurities on the surface of the detector. This methodology holds potential utility particularly in situations where dosimeters are not adequately stored: while the idea of employing plastic or alternative materials to shield dosimeters from radon may appear straightforward, there are numerous factors complicating its effectiveness and universal applicability, for example when the radon proof encapsulations are not sealed perfectly. Through the development of a robust protocol for fast neutron dosimetry, we can not only differentiate between tracks produced by alpha particles of varying energy levels but also quantify the dose resulting from exposure to the neutron field. A solid-state nuclear track detector system (Politrack, Mi.am, Italy) was used to address the critical need for measuring exposure to fast neutrons, thermalized by polyethylene spheres. This advancement facilitates the implementation of more effective radioprotection strategies and contributes to the overall safety of radiation therapy procedures.
Thermally stable radiative recombination centers within trench structures of red multi-quantum wells
Authors: Pan Zuojian , Yang Han , Chen Zhizhong , Zhang Haodong , Deng Chuhan , Wang Zeren , Chen Weihua , Kang Xiangning , Jia Chuanyu , Liang Zhiwen , Wang Qi , Zhang Guoyi , Shen Bo
Published: March 2024

High-Indium (In)-content multi-quantum wells (MQWs) are generally thermally unstable due to poor crystal quality resulting from low-temperature growth. In this study, red emission was achieved by modulating trench structures using dual-colour MQW structures. Impressively, the red MQWs inside deep trenches showed excellent thermal stability despite being grown at low temperatures. After high-temperature annealing at 950 °C for 30 min, the photoluminescence (PL) intensity of red MQWs exhibited a significant reduction of 91.9% outside trenches, while it dropped by only 9.3% inside trenches, as confirmed by confocal PL mapping. Transmission electron microscopy results show that massive In-rich phases and stacking faults appeared in the MQWs outside trenches after annealing. By contrast, the red MQWs inside deep trenches remained intact in lattice arrangement without being significantly damaged. The superior thermal stability of red MQWs inside deep trenches was mainly attributed to the low-defect-density epitaxy of InGaN layers in strain-relaxed states.
Goos–Hänchen shift for coupled vibrational modes in a semiconductor structure
Authors: Villegas Diosdado , Lazcano Zorayda , Arriaga Jesús , Pérez-Álvarez R , de León-Pérez Fernando
Published: March 2024

We present a theoretical investigation of the Goös–Hanchen shift (GHS) experienced by acoustic and optical vibrational modes reflected and transmitted from the surfaces of a semiconductor thin film sandwiched between two semi-infinite media. Our study focuses on the impact of the incident angle on the GHS, considering the coupling between longitudinal and transverse modes. For acoustic vibrations, our findings reveal that the GHS can reach magnitudes up to seven times larger than the thickness of the thin film and up to 20 times larger than the incident wavelength. Besides, it is shown that this significant amplification of the GHS highlights the strong influence of the incident angle and the frequency of the modes involved. In the case of optical vibrations, we observe even more pronounced GHS values, exceeding 30 times the incident wavelength. This demonstrates the potential of GHS in acoustical systems, which opens up possibilities for applications in the design of acoustic devices.
Intelligent fault diagnosis for electro-hydrostatic actuator based on multisource information convolutional residual network
Authors: Liu Jiahui , Hu Yuanhao , Zhu Xingjun , Zhao Xiaoli , Gao Guangfa , Yao Jianyong
Published: March 2024

The electro-hydrostatic actuator (EHA), known for its advantages such as minimal throttling loss, high efficiency, and a significant volume-to-power ratio, has found extensive application in the fields of aeronautics and astronautics. However, ensuring the safety of aircraft that utilize EHAs requires efficient fault diagnosis due to the demanding operational conditions and prolonged usage. Traditional diagnostic approaches face challenges such as intricate fault modeling, complex multi-channel monitoring data, and a limited number of fault samples within the electro-hydraulic system. To overcome these challenges, we propose an intelligent diagnosis method based on a multi-source information convolutional residual network. Specifically, a multis-cale kernel is implemented to capture features at different scales, enhancing model expressiveness. The efficiency channel attention mechanism dynamically focuses on relevant channel features to improve feature learning ability. The residual network adaptively recalibrates features at each layer to facilitate fault feature learning. Additionally, the activate or not activation function is introduced to selectively activate shallow features, thereby improving the feature representation and generalization capability of the model. Experimental data from the EHA system validates the superiority of the proposed method, demonstrating a significant enhancement in the diagnostic accuracy of EHAs with limited samples.