bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-assembly of ferromagnetic particles into chains and spin under the control of traveling magnetic field
Authors: Sun Zebang , Liu Shaogang , Zhao Dan , Dong Liqiang , Qi Jinming , Guo Chang
Published: November 2023

In this paper, the spin phenomenon of self-assembly of ferromagnetic particles to form particle chains under the action of a traveling magnetic field (TMF) is investigated, and a TMF generator is designed and fabricated to experimentally observe the self-assembly and spin phenomenon of ferromagnetic particles under the action of TMF. The TMF generator is capable of generating a TMF, which is an alternating motion magnetic field with sinusoidally varying and translating magnetic induction, under the action of which a chain of self-assembled ferromagnetic particles is subjected to an alternating magnetic force thereby generating a spin motion. By analyzing the spin mechanism of the self-assembled ferromagnetic particle chain, the relationship between the rotational velocity of the spin motion of the particle chain and the frequency of the three-phase AC power supply of the TMF generator was obtained. Adjusting the frequency of the three-phase AC power supply of the TMF generator can control the spin velocity of the particle chain. TMF generator enable ferromagnetic particles to self-assemble to form particle chains and drive the particle chains to spin controllably, which has a wide range of applications in micro-robotics, biomedicine, and microfluidics.
Two modes of motions for a single disk on the vibration stage
Authors: Guan Liyang , Tian Li , Hou Meiying , Han Yilong
Published: November 2023

The motion of a single granular particle is important for understanding their collective motions on vibration stage, but it remains poorly studied for simple shaped particles, such as a disk. Here, we systematically measure the motions of a single disk with different vibration amplitudes A at a fixed vibration frequency f or a fixed acceleration a. The distributions, time-correlations, and power spectra of displacements per step, mean squared displacements and couplings for translational and rotational motions are measured. These analyses reveal that the motions randomly switch between active and inactive modes. Both a and f are important to particle’s motions and the fraction of active mode. The translational and rotational kinetic energy deviates from Boltzmann distribution and violates the equipartition theorem in each mode. We find three types of motion: rolling, lying flat, and fluttering, which give rise to active and inactive modes. The translational and rotational mean squared displacements, autocorrelations, and power spectra at different a collapse in active modes, because the disk rolls along its rim with a fixed inclination angle though our system is under vibration and confinement. The nonzero cross-correlations between particle’s translational and rotational motions indicate that only translational motions are insufficient for understanding dense particle systems.
Metastable atomic-ordered configurations for Al1/2Ga1/2N predicted by Monte-Carlo method based on first-principles calculations
Authors: Gueriba Jessiel Siaron , Mizuseki Hiroshi , Cadatal-Raduban Marilou , Sarukura Nobuhiko , Kawazoe Yoshiyuki , Nagasawa Yosuke , Hirano Akira , Amano Hiroshi
Published: November 2023

Metastability of Al
n

/12Ga1−n/12N (n= 2–10: integer) with the 1–2 monolayer (ML) in-plane configuration towards the c [0001] direction has been demonstrated recently. To theoretically explain the existence of these metastable structures, relatively large calculation cells are needed. However, previous calculations were limited to the use of small calculation cell sizes to estimate the local potential depth (Δσ) of ordered Al1/2Ga1/2N models. In this work, we were able to evaluate large calculation cells based on the interaction energies between proximate Al atoms (δE
Al–Al) in AlGaN alloys. To do this, δE
Al–Al values were estimated by first-principles calculations (FPCs) using a (5a
1 × 5a
2 × 5c) cell. Next, a survey of the possible ordered configurations using various large calculation cell models was performed using the estimated δE
Al–Al values and the Monte-Carlo method. Then, various Δσ values were estimated by FPCs and compared with the configurations previously reported by other research groups. We found that the ordered configuration obtained from the (4a
1 × 2a
2 × 1c) calculation cell (C
42) has the lowest Δσ of −9.3 meV/cation and exhibited an in-plane configuration at the c(0001) plane having (–Al–Al–Ga–Ga–) and (–Al–Ga–) sequence arrangements observed along the

m

1

1
ˉ

00

planes. Hence, we found consistencies between the morphology obtained from experiment and the shape of the primitive cell based on our numerical calculations.
TeenyNet: a novel lightweight attention model for sunflower disease detection
Authors: Zhong Yi , Tong MengJun
Published: November 2023

Sunflower is one of the oilseed crops which is popularly and widely cultivated globally and contributes significantly to human health. Leaf diseases of sunflower seriously affect the growth and yield of sunflower, which directly leads to the loss of agricultural economy. However, existing machine learning algorithms and deep learning techniques are mainly based on large models with attention mechanisms, which lack considerations in computational performance, especially model size. Therefore, this study proposes a lightweight model called TeenyNet to break through the dilemma. First, the designed global multi-frequency feature extraction module decomposes the image to extract multi-frequency multi-scale features. Then, a parameter-free maximum pooling layer further extracts edge and texture features and simplifies the network complexity through downsampling, after which the proposed lightweight dual fusion attention and multi-branching structure fuses all the feature vectors to enhance multidimensional feature learning and accelerate the model convergence. Finally, the fully connected linear layer solves the multi-classification problem of sunflower disease under natural illumination background conditions. The experimental results show that TeenyNet obtains the highest accuracy of 98.94% for sunflower disease recognition with a minimum size of 143 KB and has better recognition performance in comparison experiments. TeenyNet can be effectively used for the detection of sunflower leaf diseases to achieve disease prevention and control.
An accurate and robust visual-inertial positioning method
Authors: Niu Zhiyuan , Ren Yongjie , Lin Jiarui , Ma Keyao , Zhu Jigui
Published: November 2023

The human–machine integrated coordinate measurement is a promising coordinate measurement method with high flexibility and efficiency for the complex working environments. The cameras installed on the head-mounted measurement device achieves accurate global positioning by observing the uncoded LED landmarks, and then combines with the local measuring to obtain 3D coordinates. However, limited by the frame rate of the camera, the fast movements of the operator’s head may cause landmark misidentification and visual positioning failure. In order to improve the robustness, a visual-inertial positioning method is proposed in this paper. An inertial measurement unit (IMU) is added to compensate for the deficiency of the visual positioning and enhance the dynamic performance. An adaptive extended Kalman filter (EKF), which adjusts the measurement noise covariance matrix based on the visual positioning uncertainty, is established to obtain the optimal state estimation. And an efficient initialization procedure is presented to implement the initial registration of uncoded landmarks based on the normal distribution transform algorithm and to determine the initial state of the IMU. Furthermore, the residual chi-square test is employed to detect false pose estimate in real time and to avoid positioning failure. The experiments demonstrate that the proposed method has high static positioning accuracy (0.681 mm) and high dynamic positioning robustness. The adaptive EKF realizes reliable landmark identification under fast movements and provides a higher accuracy than the common EKF.
Mixed convection of two layers with radiative electro-magnetohydrodynamics nanofluid flow in vertical enclosure
Authors: Ellahi Rahmat , Zeeshan Ahmad , Shehzad Nasir , Hussain Aneel , Sait Sadiq M
Published: November 2023

Mixed convection flow of two layers nanofluid in a vertical enclosure is studied. The channel consists of two regions. Region I is electrically conducting while Region II is electrically non-conducting. Region I is filled with base fluid water with copper oxides nanoparticles and Region II is filled with base fluid kerosene oil with iron oxides. The simultaneous effects of electro-magnetohydrodynamics and Grashof number are also taken into account. The governing flow problem consists of nonlinear coupled differential equations which is tackled using analytical technique. Analytical results have been obtained by the homotopy analysis method (HAM). The results for the leading parameters, such as the Hartmann numbers, Grashof numbers, ratio of viscosities, width ratio, volume fraction of nanoparticles, and the ratio of thermal conductivities for three different electric field scenarios under heat generation/absorption were examined. It is found that the effect of the negative electric load parameter assists the flow while the effect of the positive electric load parameter opposes the flow as compared to the case when the electric load parameter is zero. All outcomes for significant parameters on velocity and temperature are discussed graphically.
Smartphone photography based determination of refractive index of liquid
Authors: Pal Mrinal Kanti , Panchadhyayee Pradipta
Published: November 2023

A simple but useful method is presented to measure the refractive index of a liquid using the smartphone camera. We have measured the image lengths by utilizing the ImageMeter application (free online) and determine the refractive index directly. We mention some striking points based upon which this simple method can be considered robust and novel: (i) no extra device other than the smartphone is required; (ii) there is no need to know the focal length of the camera lens of the smartphone; (iii) instead of finding the size of the object, only the image sizes of the object in different conditions are to be measured in pixel units to determine the refractive index of the liquid.
Determination of acoustic phonon anharmonicities via second-order Raman scattering in CuI
Authors: Hildebrandt R , Seifert M , George J , Blaurock S , Botti S , Krautscheid H , Grundmann M , Sturm C
Published: November 2023

We demonstrate the determination of anharmonic acoustic phonon properties via second-order Raman scattering exemplarily on copper iodide single crystals. The origin of multi-phonon features from the second-order Raman spectra was assigned by the support of the calculated 2-phonon density of states. In this way, the temperature dependence of acoustic phonons was determined down to 10 K. To determine independently the harmonic contributions of respective acoustic phonons, density functional theory in quasi-harmonic approximation was used. Finally, the anharmonic contributions were determined. The results are in agreement with earlier publications and extend CuI’s determined acoustic phonon properties to lower temperatures with higher accuracy. This approach demonstrates that it is possible to characterize the acoustic anharmonicities via Raman scattering down to zero-temperature renormalization constants of at least 0.1 cm−1.
Amplification of quantum transfer and quantum ratchet
Authors: Kozyrev Sergei V , Pechen Alexander N
Published: November 2023

Amplification of quantum transfer and ratchet–type processes are important for quantum technologies. We also expect that quantum ratchet works in quantum photosynthesis, where possible role of quantum effects is now widely discussed but the underlying dynamical processes are still not clearly known. In this work, we study a model of amplification of quantum transfer and making it directed, which we call the quantum ratchet model. The model is based on a special quantum control master equation with dynamics induced by a feedback-type process. The ratchet effect is achieved in the quantum control model with dissipation and sink, where the Hamiltonian depends on vibrations in the energy difference synchronized with transitions between energy levels. A similarity between this model and the model of coherent transport in quantum photosynthesis, where the time dependence of the Hamiltonian arises due to vibrons, is studied. Amplitude and frequency of the oscillating vibron together with the dephasing rate are the parameters of the quantum ratchet which determine its efficiency. We study with which parameters the quantum ratchet minimizes the exction recombination time and show that the experimentally known values of the parameters of the photosynthetic reaction center correspond to values of the parameters of the quantum ratchet which realize a local minimum of the exciton recombination time. We also find other values of the parameters of the quantum ratchet minimizing the exciton recombination time, which correspond to a twice smaller frequency of the vibron compared to that observed in experiments.
Wear analysis of rolling bearing contact surfaces based on finite element method
Authors: Li Wei , Tan Yalou , Tao Yaping , Bai Diaojun
Published: November 2023

Wear leads to the roughening of bearing surfaces, increased internal clearances, decreased rotational precision, and amplified vibration and noise, ultimately causing the bearing to fail to meet specified performance criteria. This study employs the quasi-static analysis method to examine bearing sliding behavior. Based on the Archard wear model and Hertz contact theory, a computational model for wear depth in lubricated conditions is established for rolling ball bearings, accounting for both the rolling and sliding of the rolling elements. The distribution law of load and wear coefficient along the raceway circumference are analyzed, along with the characteristics of stress and sliding velocity in the contact region. The study investigates the impact of rotational speed, load, surface roughness, and raceway curvature coefficient on the wear coefficient, wear depth, and minimum oil film thickness. Furthermore, sensitivity analysis is conducted on the parameters of the wear depth model. Finite element analysis, utilizing ANSYS Workbench, is employed to study the evolution of surface wear on the raceway of deep groove ball bearings and explore the dynamic relationship between contact stress and wear depth. These findings offer important theoretical guidance for the design, selection, and maintenance of rolling bearings.
Photon to axion conversion during Big Bang Nucleosynthesis
Authors: Cuesta A.J. , Illana J.I. , Masip M.
Published: November 2023

We investigate how the resonant conversion at a temperature T̅ = 25–65 keV of a fraction of the CMB photons into an axion-like majoron affects BBN. The scenario, that assumes the presence of a primordial magnetic field and the subsequent decay of the majorons into neutrinos at T ≈ 1 eV, has been proposed to solve the H
0 tension. We find two main effects. First, since we lose photons to majorons at T̅, the baryon to photon ratio is smaller at the beginning of BBN (T > T̅) than during decoupling and structure formation (T ≪ T̅). This relaxes the 2σ mismatch between the observed deuterium abundance and the one predicted by the standard ΛCDM model. Second, since the conversion implies a sudden drop in the temperature of the CMB during the final phase of BBN, it interrupts the synthesis of lithium and beryllium and reduces their final abundance, possibly alleviating the lithium problem.
Beam displacement tolerances on a segmented mirror for higher-order Hermite–Gauss modes
Authors: Tao Liu , Brown Nina , Fulda Paul
Published: November 2023

Odd-indexed higher-order Hermite–Gauss (HG) modes are compatible with four-quadrant segmented mirrors due to their intensity nulls along the principal axes, which guarantees minimum beam intensity illuminating the bond lines between the segments thus leading to low power loss. However, a misplaced HG beam can cause extra power loss due to the bright intensity spots probing the bond lines. This paper analytically and numerically studies the beam displacement tolerances on a segmented mirror for the

H

G

3
,
3

mode. We conclude that for ‘effective’ bond lines with 6 µm width, and the

H

G

3
,
3

beam size chosen to guarantee 1 ppm clipping loss when centered, the beam can be rotated by roughly 1∘ or laterally displaced by 4% of its beam size while keeping the total power on the bond lines under 1 ppm. We also demonstrate that the constrained beam displacement parameter region that guarantees a given power loss limit, or the beam displacement tolerance, is inversely proportional to the bond line thickness.
Prognostic Significance of Blood Pressure at Rest and After Performing the Six-Minute Walk Test in Patients With Acute Heart Failure
Authors: Huang Jiale , Yu Zhongping , Wu Yuzhong , He Xin , Zhao Jingjing , He Jiangui , Staessen Jan A , Dong Yugang , Liu Chen , Wei Fang-Fei
Published: November 2023

BACKGROUND

It remains unclear whether systolic (SBP) and diastolic (DBP) pressure and BP response after six-minute walk test (6MWT) are associated with adverse outcomes in patients with acute heart failure (AHF).

METHODS

We investigated these associations in 98 AHF patients (24.5% women; mean age, 70.5 years) enrolled in the ROSE trial (The Low-dose Dopamine or Low-dose Nesiritide in Acute Heart Failure with Renal Dysfunction). The primary endpoint consisted of any death or rehospitalization within 6 months after randomization. We computed hazard ratios (HRs) of the risks associated with 1-SD increase in post-exercise BP levels and BP ratios, calculated as BP immediately after 6MWT divided by BP before 6MWT.

RESULTS

The BP before and after 6MWT averaged 110.6/117.5 mm Hg for SBP and 61.9/64.7 mm Hg for DBP. In multivariable-adjusted analyses including clinic BP measured at the same day of 6MWT, higher DBP after 6MWT was associated with lower risk of the primary endpoint (HR, 0.49; 95% confidence interval [CI], 0.26–0.95; P = 0.034). Both higher SBP and DBP immediately after 6MWT were associated with lower risk of 6-month mortality (HRs, 0.39/0.16; 95% CI, 0.17–0.90/0.065–0.40; P ≤ 0.026). The post-exercise SBP ratio was associated with the risk of 6-month mortality in multivariable-adjusted analyses (HR, 0.44; P = 0.023).

CONCLUSIONS

Higher BP levels and BP ratios immediately after 6MWT conferred lower risk of adverse health outcomes. Our observations highlight that 6MWT-related BP level and response may refine risk estimates in patients hospitalized AHF and may help further investigation for the development of HF preventive strategies.
Expression analysis of genes encoding extracellular leucine-rich repeat proteins in Arabidopsis thaliana
Authors: Dutta Amit Kumar , Sultana Mst Momtaz , Tanaka Ai , Suzuki Takamasa , Hachiya Takushi , Nakagawa Tsuyoshi
Published: November 2023

Leucine-rich repeat (LRR)-containing proteins have been identified in diverse species, including plants. The diverse intracellular and extracellular LRR variants are responsible for numerous biological processes. We analyzed the expression patterns of Arabidopsis thaliana extracellular LRR (AtExLRR) genes, 10 receptor-like proteins, and 4 additional genes expressing the LRR-containing protein by a promoter: β-glucuronidase (GUS) study. According to in silico expression studies, several AtExLRR genes were expressed in a tissue- or stage-specific and abiotic/hormone stress-responsive manner, indicating their potential participation in specific biological processes. Based on the promoter: GUS assay, AtExLRRs were expressed in different cells and organs. A quantitative real-time PCR investigation revealed that the expressions of AtExLRR3 and AtExLRR9 were distinct under various abiotic stress conditions. This study investigated the potential roles of extracellular LRR proteins in plant growth, development, and response to various abiotic stresses.
From intuition to AI: evolution of small molecule representations in drug discovery
Authors: McGibbon Miles , Shave Steven , Dong Jie , Gao Yumiao , Houston Douglas R , Xie Jiancong , Yang Yuedong , Schwaller Philippe , Blay Vincent
Published: November 2023

Within drug discovery, the goal of AI scientists and cheminformaticians is to help identify molecular starting points that will develop into safe and efficacious drugs while reducing costs, time and failure rates. To achieve this goal, it is crucial to represent molecules in a digital format that makes them machine-readable and facilitates the accurate prediction of properties that drive decision-making. Over the years, molecular representations have evolved from intuitive and human-readable formats to bespoke numerical descriptors and fingerprints, and now to learned representations that capture patterns and salient features across vast chemical spaces. Among these, sequence-based and graph-based representations of small molecules have become highly popular. However, each approach has strengths and weaknesses across dimensions such as generality, computational cost, inversibility for generative applications and interpretability, which can be critical in informing practitioners’ decisions. As the drug discovery landscape evolves, opportunities for innovation continue to emerge. These include the creation of molecular representations for high-value, low-data regimes, the distillation of broader biological and chemical knowledge into novel learned representations and the modeling of up-and-coming therapeutic modalities.
Continuing Medical Education-accredited reflectance confocal microscopy course in the USA and its impact on learning and clinical integration: report from a single centre
Authors: Navarrete-Dechent Cristian , Rajadhyaksha Milind , Marghoob Ashfaq A , Nehal Kishwer S , Halpern Allan C , Rossi Anthony M , Jain Manu
Published: November 2023

Reflectance confocal microscopy (RCM) images skin lesions noninvasively at quasi-histological resolution. RCM has improved the diagnosis of skin neoplasms, and recently acquired billing codes in the USA.1 However, reading RCM images requires training, imposing a major barrier to its widespread adoption.2 To date, RCM learning has not been standardized and is primarily based on ‘mentorship’ and ‘on-site’ learning. There is a paucity of CME-accredited RCM courses in the USA and across the globe, as well as a lack of reports on CME’s clinical impact. This study aimed to evaluate the impact of a short-duration RCM course on learning and clinical integration.
Delay in diagnosis is the most important proximate reason for mortality in hereditary angio-oedema: our experience at Chandigarh, India
Authors: Kumar Jindal Ankur , Basu Suprit , Tyagi Reva , Barman Prabal , Sil Archan , Chawla Sanchi , Kaur Anit , Tyagi Rahul , Jangra Isheeta , Machhua Sanghamitra , Sendhil Kumaran Muthu , Dogra Sunil , Vinay Keshavamurthy , Bishnoi Anuradha , Sharma Rajni , Garg Ravinder , Saka Ruchi , Suri Deepti , Pandiarajan Vignesh , Pilania Rakesh , Dhaliwal Manpreet , Sharma Saniya , Rawat Amit , Singh Surjit
Published: November 2023

Background

Hereditary angio-oedema (HAE) is a rare autosomal dominant disorder characterized clinically by recurrent episodes of nonpruritic subcutaneous and/or submucosal oedema. Laryngeal oedema is the commonest cause of mortality in patients with HAE. Prior to the availability of first-line treatment options for the management of HAE, mortality was as high as 30%. Mortality has significantly declined in countries where first-line treatment options are available and patients can access these therapies. There is a paucity of literature on the outcomes of patients with HAE in developing countries where availability of and access to first-line treatment options are still a challenge.

Objectives

To report our experience on mortality in patients with HAE and to report factors associated with the death of these patients.

Methods

We carried out a record review of all patients diagnosed with HAE between January 1996 and August 2022. Families with HAE who had reported the death of at least one family member/relative from laryngeal oedema were studied in detail.

Results

Of the 65 families (170 patients) registered in the clinic, 16 families reported the death of at least one family member/relative from laryngeal oedema (total of 36 deaths). Of these 16 families, 14 reported that 1 or more family members had experienced at least 1 attack of laryngeal oedema. One patient died during follow-up when she was taking long-term prophylaxis with stanozolol and tranexamic acid, while the remaining 35 patients were not diagnosed with HAE at the time of their death. At the time of death of all 36 patients, at least 1 other family member had symptoms suggestive of HAE, but the diagnosis was not established for the family.

Conclusions

To our knowledge, this is the largest single-centre cohort of patients with HAE in India reporting mortality data and factors associated with death in these families. The delay in diagnosis is the most important reason for mortality.
Increased regional Hurst exponent reflects response inhibition related neural complexity alterations in pediatric bipolar disorder patients during an emotional Go-Nogo task
Authors: Guo Yi-Bing , Jiao Qing , Zhang Xiao-Tong , Xiao Qian , Wu Zhou , Cao Wei-Fang , Cui Dong , Yu Guang-Hui , Dou Ru-Hai , Su Lin-Yan , Lu Guang-Ming
Published: November 2023

Fractal patterns have been shown to change in resting- and task-state blood oxygen level-dependent signals in bipolar disorder patients. However, fractal characteristics of brain blood oxygen level-dependent signals when responding to external emotional stimuli in pediatric bipolar disorder remain unclear. Blood oxygen level-dependent signals of 20 PBD-I patients and 17 age- and sex-matched healthy controls were extracted while performing an emotional Go-Nogo task. Neural responses relevant to the task and Hurst exponent of the blood oxygen level-dependent signals were assessed. Correlations between clinical indices and Hurst exponent were estimated. Significantly increased activations were found in regions covering the frontal lobe, parietal lobe, temporal lobe, insula, and subcortical nuclei in PBD-I patients compared to healthy controls in contrast of emotional versus neutral distractors. PBD-I patients exhibited higher Hurst exponent in regions that involved in action control, such as superior frontal gyrus, inferior frontal gyrus, inferior temporal gyrus, and insula, with Hurst exponent of frontal orbital gyrus correlated with onset age. The present study exhibited overactivation, increased self-similarity and decreased complexity in cortical regions during emotional Go-Nogo task in patients relative to healthy controls, which provides evidence of an altered emotional modulation of cognitive control in pediatric bipolar disorder patients. Hurst exponent may be a fractal biomarker of neural activity in pediatric bipolar disorder.
Effectiveness of an Unsupervised Primaquine Regimen for Preventing Plasmodium vivax Malaria Relapses in Northeast Myanmar: A Single-Arm Nonrandomized Observational Study
Authors: Malla Pallavi , Wang Zenglei , Brashear Awtum , Yang Zhaoqing , Lo Eugenia , Baird Kevin , Wang Chengqi , Cui Liwang
Published: November 2023

Background

Plasmodium vivax presents a significant challenge for malaria elimination in the Greater Mekong Subregion. We evaluated the effectiveness of primaquine for reducing relapses of vivax malaria.

Methods

Patients with uncomplicated P vivax malaria from eastern Myanmar received chloroquine (25-mg base/kg given in 3 days) plus unsupervised PQ (0.25 mg/kg/d for 14 days) without screening for glucose-6-phosphate dehydrogenase deficiency and were followed for a year.

Results

A total of 556 patients were enrolled to receive the chloroquine/primaquine treatment from February 2012 to August 2013. During the follow-up, 38 recurrences were detected, presenting a cumulative recurrence rate of 9.1% (95% CI, 4.1%–14.1%). Genotyping at the pvmsp1 and pvmsp3α loci by amplicon deep sequencing and model prediction indicated that 13 of the 27 recurrences with genotyping data were likely due to relapses. Notably, all confirmed relapses occurred within the first 6 months.

Conclusions

The unsupervised standard dose of primaquine was highly effective as a radical cure for P vivax malaria in eastern Myanmar. The high presumed effectiveness might have benefited from the health messages delivered during the enrollment and follow-up activities. Six-month follow-ups in the Greater Mekong Subregion are sufficient for detecting most relapses.
The incorporation of extracellular vesicle markers varies among vesicles with distinct surface charges
Authors: Maeda Koki , Goto Simon , Miura Koya , Saito Koki , Morita Eiji
Published: November 2023

Extracellular vesicles (EVs) are important mediators of intercellular communication. However, the methods available for distinguishing the heterogeneity of secreted EVs and isolating and purifying them are limited. This study introduced a HiBiT-tag to detect various EV markers, including CD63, CD9, Epidermal Growth Factor Receptor (EGFR), Flotilin1, and Syndecan-1, and investigated whether these marker-containing vesicles were capable of binding to differently charged column carriers. Four column carriers, Diethylaminoethyl (DEAE), Capto Adhere, Blue and Heparin, showed affinity for CD63 containing EVs, but their elution patterns varied. Furthermore, we observed that the elution patterns of the EV markers differed among vesicles with distinct surface charges when a DEAE column was used. This suggests that the incorporation of EV markers varied between these vesicles. The markers showed different subcellular localizations, indicating that the site of vesicle formation may contribute to the production of vesicles with varying charges and marker incorporation. These findings may have implications for the development of methods to purify homogeneous EVs, which could be useful in EV-mediated drug delivery systems.
Black hole binaries in AGN accretion discs – II. Gas effects on black hole satellite scatterings
Authors: Rowan Connar , Whitehead Henry , Boekholt Tjarda , Kocsis Bence , Haiman Zoltán
Published: November 2023

The black hole (BH) binaries in active galactic nuclei (AGN) are expected to form mainly through scattering encounters in the ambient gaseous medium. Recent simulations, including our own, have confirmed this formation pathway is highly efficient. We perform 3D smoothed particle hydrodynamics (SPH) simulations of BH scattering encounters in AGN discs. Using a range of impact parameters, we probe the necessary conditions for binary capture and how different orbital trajectories affect the dissipative effects from the gas. We identify a single range of impact parameters, typically of width ∼0.86−1.59 binary Hill radii depending on AGN disc density, that reliably leads to binary formation. The periapsis of the first encounter is the primary variable that determines the outcome of the initial scattering. We find an associated power law between the energy dissipated and the periapsis depth to be ΔE ∝ r−b with b = 0.42 ± 0.16, where deeper encounters dissipate more energy. Excluding accretion physics does not significantly alter these results. We identify the region of parameter space in initial energy versus impact parameter where a scattering leads to binary formation. Based on our findings, we provide a ready-to-use analytic criterion that utilizes these two pre-encounter parameters to determine the outcome of an encounter, with a reliability rate of >90 per cent. As the criterion is based directly on our simulations, it provides a reliable and highly physically motivated criterion for predicting binary scattering outcomes which can be used in population studies of BH binaries and mergers around AGN.
Emulation of the cosmic dawn 21-cm power spectrum and classification of excess radio models using an artificial neural network
Authors: Sikder Sudipta , Barkana Rennan , Reis Itamar , Fialkov Anastasia
Published: November 2023

The cosmic 21-cm line of hydrogen is expected to be measured in detail by the next generation of radio telescopes. The enormous data set from future 21-cm surveys will revolutionize our understanding of early cosmic times. We present a machine learning approach based on an artificial neural network that uses emulation in order to uncover the astrophysics in the epoch of reionization and cosmic dawn. Using a seven-parameter astrophysical model that covers a very wide range of possible 21-cm signals, over the redshift range 6 to 30 and wavenumber range 0.05 to $1 \ \rm {Mpc}^{-1}$ we emulate the 21-cm power spectrum with a typical accuracy of $10 - 20~{{\ \rm per\ cent}}$. As a realistic example, we train an emulator using the power spectrum with an optimistic noise model of the square kilometre array (SKA). Fitting to mock SKA data results in a typical measurement accuracy of 2.8 per cent in the optical depth to the cosmic microwave background, 34 per cent in the star-formation efficiency of galactic haloes, and a factor of 9.6 in the X-ray efficiency of galactic haloes. Also, with our modelling we reconstruct the true 21-cm power spectrum from the mock SKA data with a typical accuracy of $15 - 30~{{\ \rm per\ cent}}$. In addition to standard astrophysical models, we consider two exotic possibilities of strong excess radio backgrounds at high redshifts. We use a neural network to identify the type of radio background present in the 21-cm power spectrum, with an accuracy of 87  per cent for mock SKA data.
Chaotic Type I migration in turbulent discs
Authors: Wu Yinhao , Chen Yi-Xian , Lin Douglas N C
Published: November 2023

By performing global hydrodynamical simulations of accretion discs with driven turbulence models, we demonstrate that elevated levels of turbulence induce highly stochastic migration torques on low-mass companions embedded in these discs. This scenario applies to planets migrating within gravito-turbulent regions of protoplanetary discs as well as stars and black holes embedded in the outskirts of active galactic nucleus (AGN) accretion discs. When the turbulence level is low, linear Lindblad torque persists in the background of stochastic forces and its accumulative effect can still dominate over relatively long time-scales. However, in the presence of very stronger turbulence, classical flow patterns around the companion embedded in the disc are disrupted, leading to significant deviations from the expectations of classical Type I migration theory over arbitrarily long time-scales. Our findings suggest that the stochastic nature of turbulent migration can prevent low-mass companions from monotonically settling into universal migration traps within the traditional laminar disc framework, thus reducing the frequency of three-body interactions and hierarchical mergers compared to previously expected. We propose a scaling for the transition mass ratio from classical to chaotic migration q ∝ αR, where αR is the Reynolds viscosity stress parameter, which can be further tested and refined by conducting extensive simulations over the relevant parameter space.
Energy–momentum and angular momentum densities in the Poincaré gauge theory of gravity
Authors: Kawai Toshiharu
Published: November 2023

In the $\overline{\rm {Poincar\acute{e}}}$ gauge theory of gravity, we examine the energy–momentum and angular momentum densities of the source of the gravitational field (gauge potentials $A^{k}{}_{\mu }, \, A^{kl}{}_{\mu }$). There are two types of these quantities, the Hilbert-type densities ${\boldsymbol \Theta}_{k}{}^{\mu },\, {\boldsymbol \Phi}_{kl}{}^{\mu }$, which appear in the right-hand sides of the gravitational field equations, and $\, ^{M}{\boldsymbol T}_{k}{}^{\mu }, \, ^{M}{\boldsymbol S}_{kl}{}^{\mu }$, which are the densities (Noether currents) of the generators of $T^{4}\underline{\otimes }SL(2,C)$ transformations. We show that these are identical to each other, respectively, i.e., ${\boldsymbol \Theta}_{k}{}^{\mu }\equiv \, ^{M}{\boldsymbol T}_{k}{}^{\mu } ,\, {\boldsymbol \Phi}_{kl}{}^{\mu }\equiv \, ^{M}{\boldsymbol S}_{kl}{}^{\mu }$, in parallel with the cases of the electromagnetic and Yang–Mills fields.
‘Telling them “that’s what it says in the guidance” didn’t feel good enough’: moral distress during the pandemic in UK public health professionals
Authors: Bow Steven M A , Schröder-Bäck Peter , Norcliffe-Brown Dominic , Wilson James , Tahzib Farhang
Published: November 2023

Background

The study aimed to identify the causes of moral distress in public health professionals associated with the COVID-19 pandemic, and the potential ways of avoiding or mitigating the distress.

Methods

The survey was distributed to all members of the UK Faculty of Public Health between 14 December 2021 and 23 February 2022. Conventional qualitative content analysis was conducted to explore the situations in which moral distress arises, the moral judgments that led to distress and the proposed ways to address moral distress.

Results

A total of 629 responses were received from respondents broadly representative of the public health professional workforce. The main situations causing moral distress were national policy, guidance and law; public health advice; and workplace environments. Moral distress was precipitated by judgments about having caused injury, being unable to do good, dishonest communications and unjust prioritization. The need to improve guidance, communication and preparedness was recognized, though there was disagreement over how to achieve this. There were consistent calls for more subsidiarity, moral development and support and freedom to voice concerns.

Conclusions

The causes of moral distress in public health are distinct from other healthcare professions. Important proposals for addressing moral distress associated with the COVID-19 pandemic have been voiced by public health professionals themselves.
Folic acid antioxidant supplementation to binge drinking adolescent rats improves hydric‐saline balance and blood pressure, but fails to increase renal NO availability and glomerular filtration rate
Authors: Gallego‐López María del Carmen , Ojeda María Luisa , Romero‐Herrera Inés , Rua Rui Manuel , Carreras Olimpia , Nogales Fátima
Published: November 2023

Binge drinking (BD) is an especially pro‐oxidant pattern of alcohol consumption, particularly widespread in the adolescent population. In the kidneys, it affects the glomerular filtration rate (GFR), leading to high blood pressure. BD exposure also disrupts folic acid (FA) homeostasis and its antioxidant properties. The aim of this study is to test a FA supplementation as an effective therapy against the oxidative, nitrosative, and apoptotic damage as well as the renal function alteration occurred after BD in adolescence. Four groups of adolescent rats were used: control, BD (exposed to intraperitoneal alcohol), control FA‐supplemented group and BD FA‐supplemented group. Dietary FA content in control groups was 2 ppm, and 8 ppm in supplemented groups. BD provoked an oxidative imbalance in the kidneys by dysregulating antioxidant enzymes and increasing the enzyme NADPH oxidase 4 (NOX4), which led to an increase in caspase‐9. BD also altered the renal nitrosative status affecting the expression of the three nitric oxide (NO) synthase (NOS) isoforms, leading to a decrease in NO levels. Functionally, BD produced a hydric‐electrolytic imbalance, a low GFR and an increase in blood pressure. FA supplementation to BD adolescent rats improved the oxidative, nitrosative, and apoptotic balance, recovering the hydric‐electrolytic equilibrium and blood pressure. However, neither NO levels nor GFR were recovered, showing in this study for the first time that NO availability in the kidneys plays a crucial role in GFR regulation that the antioxidant effects of FA cannot repair.
Physiologic Treatment of Severe Hypertension in Pregnancy and Postpartum
Authors: Davis Allison M. , Blanchard Christina T. , Subramaniam Akila , Sinkey Rachel G. , Tita Alan T. , Battarbee Ashley N.
Published: November 2023

We aimed to evaluate physiologic treatment of severe hypertension. This was a retrospective cohort study of pregnant and postpartum patients with severe hypertension (systolic blood pressure [BP] 160 mm Hg or higher or diastolic BP 110 mm Hg or higher) treated with intravenous labetalol or hydralazine at a single tertiary care center between 2013 and 2018. Patients were classified as having physiologic treatment if they had hyperdynamic physiology (pulse pressure 65 mm Hg or higher) and received labetalol or had vasoconstrictive physiology (diastolic BP 100 mm Hg or higher) and received hydralazine. The primary outcome was number of antihypertensive doses to achieve nonsevere BP. Of 1,120 patients included in the analysis, 653 had physiologic treatment and 467 had nonphysiologic treatment, with 16 (1.4%) excluded for inability to classify physiology. Physiologic treatment was associated with fewer antihypertensive doses (1.4±0.9 doses vs 1.6±1.4 doses; adjusted β −0.28, 95% CI, −0.42 to −0.14) and lower odds of medication conversion (2.5% vs 4.7%; adjusted odds ratio 0.48, 95% CI, 0.24–0.93) but no difference in time to nonsevere BP (31 minutes [interquartile range 16–66 minutes] vs 34 minutes [interquartile range 15–76 minutes]; adjusted hazard ratio 1.0, 95% CI, 0.9–1.2). Physiologic treatment of severe hypertension warrants further evaluation.
Frequency and Characteristics of Posterior Labral Injuries in Operative Acetabular Fractures Treated Through a Posterior Approach: A Prospective Observational Study
Authors: Nolte Elizabeth , Blommer Joseph , Som Maria , Parsa Shirin , Kim Peter , Hasan Sania , Boissonneault Adam , O’Hara Nathan N. , Slobogean Gerard P. , O’Toole Robert V.
Published: November 2023

OBJECTIVE:

The association between labral injuries and acetabular fractures is unknown. This study aimed to identify the frequency and characteristics of labral injuries in operatively treated acetabular fractures that cannot be identified on preoperative imaging.

METHODS:

Design:

Prospective observational cohort.

Setting:

Level I trauma center.

Patient Selection Criteria:

Adult patients with an acetabular fracture operatively treated through a posterior approach.

Outcome Measures and Comparisons:

The frequency and characteristics of labral injuries.

RESULTS:

Fifty-three of 71 acetabular fractures (75%; 95% CI, 63%–83%) demonstrated a labral injury visible via the posterior approach. Posterior labral injuries occured in 88.7% of operative acetabular fracture patterns involving the posterior wall and most commonly represent a detachment of the posteroinferior labrum (n = 39, 75%). Fractures with a labral injury were more likely to have gluteus minimus damage (93% vs. 61%, P = 0.02), femoral head lesions (38% vs.17%, P = 0.03), joint capsule detachment (60% vs. 33%, P = 0.05), and fracture patterns involving the posterior wall (89% vs. 50%, P = 0.05).

CONCLUSIONS:

This study describes the high rate (89%) of posterior labral injuries in posterior wall fractures, the most common injury pattern being a detachment of the posteroinferior labrum. Labral injuries in acetabular fractures may have important clinical implications and this study is the first to identify the frequency and characteristics of these injuries. Further studies should assess the relationship between labral injuries, treatment strategies, and the progression to post-traumatic osteoarthritis.
Reimbursement of Lumbar Fusion at an Orthopaedic Specialty Hospital Versus Tertiary Referral Center
Authors: Karamian Brian A. , Canseco Jose A. , Kanhere Arun P. , Minetos Paul D. , Lambrechts Mark J. , Lee Yunsoo , Trenchfield Delano , Pohl Nicholas , Kothari Parth , Conaway William , Jeyamohan Hareindra , Endersby Kevin , Kaye David , Woods Barrett I. , Rihn Jeffrey A. , Kurd Mark F. , Hilibrand Alan S. , Kepler Christopher K. , Vaccaro Alexander R. , Schroeder Gregory D.
Published: November 2023

Study Design:

Retrospective Cohort Study.

Objective:

To explore the differences in Medicare reimbursement for lumbar fusion performed at an orthopaedic specialty hospital (OSH) and a tertiary referral center and to elucidate drivers of Medicare reimbursement differences.

Summary of Background Data:

To provide more cost-efficient care, appropriately selected patients are increasingly being transitioned to OSHs for lumbar fusion procedures. There are no studies directly comparing reimbursement of lumbar fusion between tertiary referral centers (TRC) and OSHs.

Methods:

Reimbursement data for a tertiary referral center and an orthopaedic specialty hospital were compiled through the Centers for Medicare and Medicaid Services. Any patient with lumbar fusions between January 2014 and December 2018 were identified. OSH patients were matched to TRC patients by demographic and surgical variables. Outcomes analyzed were reimbursement data, procedure data, 90-day complications and readmissions, operating room times, and length of stay (LOS).

Results:

A total of 114 patients were included in the final cohort. The tertiary referral center had higher post-trigger ($13,554 vs. $8,541, P<0.001) and total episode ($49,973 vs. $43,512, P<0.010) reimbursements. Lumbar fusion performed at an OSH was predictive of shorter OR time (β=0.77, P<0.001), shorter procedure time (β=0.71, P<0.001), and shorter LOS (β=0.53, P<0.001). There were no significant differences in complications (9.21% vs. 15.8%, P=0.353) or readmission rates (3.95% vs. 7.89%, P=0.374) between the 2 hospitals; however, our study is underpowered for complications and readmissions.

Conclusion:

Lumbar fusion performed at an OSH, compared with a tertiary referral center, is associated with significant Medicare cost savings, shorter perioperative times, decreased LOS, and decreased utilization of post-acute resources.

Level of Evidence:

3.