bluuebunny/crossref_metadata_2025 huggingface dataset:
Importance of dialysis specialists in early mortality in elderly hemodialysis patients: a multicenter retrospective cohort study
Authors: Park Yohan , Lee Ji Won , Yoon Se-Hee , Yun Sung-Ro , Kim Hyunsuk , Bae Eunjin , Hyun Young Youl , Chung Sungjin , Kwon Soon Hyo , Cho Jang-Hee , Yoo Kyung Don , Park Woo Yeong , Sun In O , Yu Byung Chul , Ko Gang-Jee , Yang Jae Won , Song Sang Heon , Shin Sung Joon , Hong Yu Ah , Hwang Won Min
Published: January 2024

The early mortality rate in elderly patients undergoing hemodialysis is more than twice that in young patients, requiring more specialized healthcare. We investigated whether the number of professional dialysis specialists affected early mortality in elderly patients undergoing hemodialysis. This multicenter retrospective cohort study analyzed data from 1860 patients aged ≥ 70 years who started hemodialysis between January 2010 and December 2017. Study regions included Seoul, Gyeonggi-do, Gangwon-do, Daejeon/Chungcheong-do, Daegu/Gyeongsangbuk-do, and Busan/Ulsan/Gyeongsangnam-do. The number of patients undergoing hemodialysis per dialysis specialist was calculated using registered data from each hemodialysis center. Early mortality was defined as death within 6 months of hemodialysis initiation. Gangwon-do (28.3%) and Seoul (14.5%) showed the highest and lowest early mortality rate, respectively. Similarly, Gangwon-do (64.6) and Seoul (43.9) had the highest and lowest number of patients per dialysis specialist, respectively. Relatively consistent results were observed for the regional rankings of early mortality rate and number of patients per dialysis specialist. Multivariate Cox regression analysis—adjusted for previously known significant risk factors—revealed that the number of patients per dialysis specialist was an independent risk factor for early mortality (hazard ratio: 1.031, p < 0.001). This study underscores the growing need for dialysis specialists for elderly hemodialysis patients in Korea.
Classification feasibility test on multi-lead electrocardiography signals generated from single-lead electrocardiography signals
Authors: Yoon Gi-Won , Joo Segyeong
Published: January 2024

Nowadays, Electrocardiogram (ECG) signals can be measured using wearable devices, such as smart watches. Most wearable devices provide only a few details; however, they have the advantage of recording data in real time. In this study, 12-lead ECG signals were generated from lead I and their feasibility was tested to obtain more details. The 12-lead ECG signals were generated using a U-net-based generative adversarial network (GAN) that was trained on ECG data obtained from the Asan Medical Center. Subsequently, unseen PTB-XL PhysioNet data were used to produce real 12-lead ECG signals for classification. The generated and real 12-lead ECG signals were then compared using a ResNet classification model; and the normal, atrial fibrillation (A-fib), left bundle branch block (LBBB), right bundle branch block (RBBB), left ventricular hypertrophy (LVH), and right ventricular hypertrophy (RVH) were classified. The mean precision, recall, and f1-score for the real 12-lead ECG signals are 0.70, 0.72, and 0.70, and that for the generated 12-lead ECG signals are 0.82, 0.80, and 0.81, respectively. In our study, according to the result generated 12-lead ECG signals performed better than real 12-lead ECG.
Effect of milk exposure on the redox profile of Caenorhabditis elegans
Authors: de Oliveira Ingrid Laíse Silvestre , Silva Giovanna Melo Martins , Cadavid Cesar Orlando Muñoz , Sales Danielle Cavalcanti , Anaya Katya , de Paula Oliveira Riva , do Nascimento Rangel Adriano Henrique
Published: January 2024

The consumption of bovine milk and its derivatives is associated with inflammation, gastrointestinal disorders and the development of diseases in humans. Most studies related to milk effects are based on either clinal trials or experimental models such as mice and cell cultures. In this study we present the nematode Caenorhabditis elegans as an alternative model to evaluate the effects of milk on oxidative stress in other animal models. The toxicological effect of 20% milk exposure for 8 h on C. elegans was evaluated by progeny quantification, body size and pharyngeal pumping rate. Treating the worms with milk did not affect the worms brood size but interfered with their fecundity by delaying the average number of eggs in the first day of oviposition when compared to the control group. The size of worms treated with milk were significantly smaller compared to control. The pharyngeal pumping rate of milk-treated animals was not significantly different compared to untreated animals. Taking together, the results suggest that 20% milk treatment is not toxic for the worms but induces a minor delay achieving its adulthood and therefore its reproduction period. Milk exposure did not reduce the worms’ survival under stress conditions and increase endogenous ROS levels. This study contributes to characterize the effects of milk exposure on the C. elegans nematode.
A MEK inhibitor arrests the cell cycle of human conjunctival fibroblasts and improves the outcome of glaucoma filtration surgery
Authors: Lee Jinhee , Honjo Megumi , Aihara Makoto
Published: January 2024

Better agents are needed to improve glaucoma filtration surgery outcomes compared to current ones. The purpose of this study is to determine whether mitogen-activated protein kinase kinase (MEK) inhibitors can effectively arrest the cell cycle of human conjunctival fibroblasts (HCFs) and inhibit the formation of fibrosis and scarring following glaucoma filtration surgery. A cell counting kit‑8 assay revealed that the MEK inhibitor PD0325901 exhibited concentration-dependent growth inhibition of HCFs. Quantitative PCR, immunocytochemistry, and western blotting demonstrated decreased expression of proliferating cell nuclear antigen (PCNA) and cyclin D1 and increased expression of p27 in HCFs treated with PD0325901. Flow cytometry indicated that PD0325901 arrested the cell cycle of HCFs in the G0/1 phase. The cell-migration assay showed that HCF migration rate was significantly suppressed by PD0325901 exposure. Rabbits were divided into PD0325901-treatment and control groups, and glaucoma filtration surgery was performed. Although intraocular pressure did not differ between PD0325901-treatment and control groups, bleb height was greater in the treatment group. Histopathological evaluation revealed that fibrotic changes were significantly attenuated in the PD0325901-treatment group compared to the control group. In conclusion, the MEK inhibitor impedes HCF proliferation via cell-cycle arrest and may be beneficial for glaucoma filtration surgery by reducing bleb scarring.
Combination of clinical information and radiomics models for the differentiation of acute simple appendicitis and non simple appendicitis on CT images
Authors: Zhao Yinming , Wang Xin , Zhang Yaofeng , Liu Tao , Zuo Shuai , Sun Lie , Zhang Junling , Wang Kexin , Liu Jing
Published: January 2024

To investigate the radiomics models for the differentiation of simple and non-simple acute appendicitis. This study retrospectively included 334 appendectomy cases (76 simple and 258 non-simple cases) for acute appendicitis. These cases were divided into training (n = 106) and test cohorts (n = 228). A radiomics model was developed using the radiomic features of the appendix area on CT images as the input variables. A CT model was developed using the clinical and CT features as the input variables. A combined model was developed by combining the radiomics model and clinical information. These models were tested, and their performance was evaluated by receiver operating characteristic curves and decision curve analysis (DCA). The variables independently associated with non-simple appendicitis in the combined model were body temperature, age, percentage of neutrophils and Rad-score. The AUC of the combined model was significantly higher than that of the CT model (P = 0.041). The AUC of the radiomics model was also higher than that of the CT model but did not reach a level of statistical significance (P = 0.053). DCA showed that all three models had a higher net benefit (NB) than the default strategies, and the combined model presented the highest NB. A nomogram of the combined model was developed as the graphical representation of the final model. It is feasible to use the combined information of clinical and CT radiomics models for the differentiation of simple and non-simple acute appendicitis.
A novel reactive-extractive distillation process for separation of water/methanol/tetrahydrofuran mixtures
Authors: Neyestani F. , Eslamloueyan R.
Published: January 2024

The design of separation systems for the purification of azeotropic mixtures is of great importance in the chemical industries from economic and environmental points of view. Two novel reactive-extractive distillation (RED) processes, new design (I) and new design (II), were proposed for separating the azeotropic mixture of water/methanol/tetrahydrofuran (THF). These processes were compared to a conventional extractive distillation (ED) process. New design (I) employs dimethyl sulfoxide as a solvent, while new design (II) utilizes ethylene glycol. Ethylene oxide was introduced to the first column in both designs, enabling the in-situ production of ethylene glycol, a valuable byproduct. This is a novel solution to separate water from the azeotropic mixture by reaction between ethylene oxide and water. Aspen Plus software was used to simulate and design the processes. Both suggested designs were compared economically with the base design which is an ED process. According to the results, the new design (I) is more cost-effective and environmentally friendly alternative to the base design and the new design (II). It has a lower total capital cost and produces less carbon dioxide. Additionally, it generates a valuable by-product, ethylene glycol, which can be sold for substantial revenue. As a result, the new design (I) is the preferred choice for replacing the conventional extractive distillation method.
Research on surface defect detection algorithm of pipeline weld based on YOLOv7
Authors: Xu Xiangqian , Li Xing
Published: January 2024

Aiming at the problems of low target detection accuracy and high leakage rate of the current traditional weld surface defect detection methods and existing detection models, an improved YOLOv7 pipeline weld surface defect detection model is proposed to improve detection results. In the improved model, a Le-HorBlock module is designed, and it is introduced into the back of fourth CBS module of the backbone network, which preserves the characteristics of high-order information by realizing second-order spatial interaction, thus enhancing the ability of the network to extract features in weld defect images. The coordinate attention (CoordAtt) block is introduced to enhance the representation ability of target features, suppress interference. The CIoU loss function in YOLOv7 network model is replaced by the SIoU, so as to optimize the loss function, reduce the freedom of the loss function, and accelerate convergence. And a new large-scale pipeline weld surface defect dataset containing 2000 images of pipeline welds with weld defects is used in the proposed model. In the experimental comparison, the improved YOLOv7 network model has greatly improved the missed detection rate compared with the original network. The experimental results show that the improved YOLOv7 network model mAP@80.5 can reach 78.6%, which is 15.9% higher than the original model, and the detection effect is better than the original network and other classical target detection networks.
Non-fatal outcomes of COVID-19 disease in pediatric organ transplantation associates with down-regulation of senescence pathways
Authors: Subramanian Kumar , Varghese Rency , Pochedly Molly , Muralidaran Vinona , Yazigi Nada , Kaufman Stuart , Khan Khalid , Vitola Bernadette , Kroemer Alexander , Fishbein Thomas , Ressom Habtom , Ekong Udeme D.
Published: January 2024

This is a cross-sectional study examining kinetics and durability of immune response in children with solid organ transplants (SOTs) who had COVID-19 disease between November 2020 through June 2022, who were followed for 60-days at a single transplant center. Blood was collected between 1–14 (acute infection), and 15–60 days of a positive PCR (convalescence). SOT children with peripheral blood mononuclear cells (PBMC) cryopreserved before 2019 were non-infected controls (ctrls). PBMCs stimulated with 15-mer peptides from spike protein and anti-CD49d/anti-CD28. Testing done included mass cytometry, mi-RNA sequencing with confirmatory qPCR. 38 children formed the study cohort, 10 in the acute phase and 8 in the convalescence phase. 20 subjects were non-infected controls. Two subjects had severe disease. Subjects in the acute and convalescent phases were different subjects. The median age and tacrolimus level at blood draw was not significantly different. There was no death, and no subject was lost to follow-up. During acute infection CD57 expression was low in NKT, Th17 effector memory, memory Treg, CD4−CD8−, and γδT cells (p = 0.01, p = 0.04, p = 0.03, p = 0.03, p = 0.004 respectively). The frequencies of NK and Th2 effector memory cells increased (p = 0.01, p = 0.02) during acute infection. Non-switched memory B and CD8 central memory cell frequencies were decreased during acute infection (p = 0.02; p = 0.02), but the decrease in CD8 central memory cells did not persist. CD4−CD8− and CD14 monocyte frequencies increased during recovery (p = 0.03; p = 0.007). Our observations suggest down regulation of CD57 with absence of NK cell contraction protect against death from COVID-19 disease in children with SOTs.
Biophysical chemistry behind sickle cell anemia and the mechanism of voxelotor action
Authors: Suhail Mohd.
Published: January 2024

Sickle cell anemia disease has been a great challenge to the world in the present situation. It occurs only due to the polymerization of sickle hemoglobin (HbS) having Pro–Val–Glu typed mutation, while the polymerization does not occur in normal hemoglobin (HbA) having Pro–Glu–Glu peptides. It is also well confirmed that the oxygenated HbS (OHbS) does not participate in the polymerization, while the deoxygenated HbS (dHbS) does, which causes the shape of red blood cells sickled. After polymerization, the blood has a low oxygen affinity. Keeping this fact into consideration, only those drugs are being synthesized that stabilize the OHbS structure so that the polymerization of HbS can be stopped. The literature data showed no systematic description of the changes occurring during the OHbS conversion to dHbS before polymerization. Hence, an innovative reasonable study between HbA and HbS, when they convert into their deoxygenated forms, was done computationally. In this evaluation, physiochemical parameters in HbA/HbS before and after deoxygenation were studied and compared deeply. The computationally collected data was used to understand the abnormal behaviour of dHbS arising due to the replacement of Glu6 with Val6. Consequently, during the presented computational study, the changes occurring in HbS were found opposite/abnormal as compared to HbA after the deoxygenation of both. The mechanism of Voxelotor (GBT-440) action to stop the HbS polymerization was also explained with the help of computationally collected data. Besides, a comparative study between GBT-440 and another suggested drug was also done to know their antisickling strength. Additionally, the effect of pH, CO, CO2, and 2,3-diphosphoglycerate (2,3-DPG) on HbS structure was also studied computationally.
Oculomotor inhibition markers of working memory load
Authors: Kadosh Oren , Inbal Kfir , Snir Hadar , Bonneh Yoram S.
Published: January 2024

Involuntary eye movements occur constantly even during fixation and were shown to convey information about cognitive processes. They are inhibited momentarily in response to external stimuli (oculomotor inhibition, OMI), with a time and magnitude that depend on stimulus saliency, attention, and expectations. It was recently shown that the working memory load for numbers modulates the microsaccade rate; however, the generality of the effect and its temporal properties remain unclear. Our goal was to investigate the relationship between OMI and the working memory load for simple colored shapes. Participants (N = 26) maintained their fixation while their eyes were tracked; they viewed briefly flashed colored shapes accompanied by small arrows indicating the shapes to be memorized (1/2/3). After a retention period, a probe shape appeared for matching. The microsaccade rate modulation and temporal properties were analyzed for the memory encoding, maintenance, and retrieval phases. Microsaccade inhibition was stronger when more shapes were memorized, and performance improved when microsaccades were suppressed during maintenance and retrieval. This occurred even though the physical stimuli were identical in number under all conditions. Thus, oculomotor inhibition may play a role in silencing the visual input while processing current stimuli and is generally related to processing time and load.
Converging synaptic and network dysfunctions in distinct autoimmune encephalitis
Authors: Hunter Daniel , Petit-Pedrol Mar , Fernandes Dominique , Bénac Nathan , Rodrigues Catarina , Kreye Jakob , Ceanga Mihai , Prüss Harald , Geis Christian , Groc Laurent
Published: January 2024

Psychiatric and neurological symptoms, as well as cognitive deficits, represent a prominent phenotype associated with variable forms of autoimmune encephalitis, regardless of the neurotransmitter receptor targeted by autoantibodies. The mechanistic underpinnings of these shared major neuropsychiatric symptoms remain however unclear. Here, we investigate the impacts of patient-derived monoclonal autoantibodies against the glutamatergic NMDAR (NMDAR mAb) and inhibitory GABAaR (GABAaR mAb) signalling in the hippocampal network. Unexpectedly, both excitatory and inhibitory synaptic receptor membrane dynamics, content and transmissions are altered by NMDAR or GABAaR mAb, irrespective of the affinity or antagonistic effect of the autoantibodies. The effect of NMDAR mAb on inhibitory synapses and GABAaR mAb on excitatory synapses requires neuronal activity and involves protein kinase signalling. At the cell level, both autoantibodies increase the excitation/inhibition balance of principal cell inputs. Furthermore, NMDAR or GABAaR mAb leads to hyperactivation of hippocampal networks through distinct alterations of principal cell and interneuron properties. Thus, autoantibodies targeting excitatory NMDAR or inhibitory GABAaR trigger convergent network dysfunctions through a combination of shared and distinct mechanisms.
Supramolecular assemblies of Cu(ii) with a tetraphenylethene-imidazole ligand for tuning photocatalytic CO2 reduction
Authors: Qiu Zhao-Feng , Wang Peng , Zhang Xiao-Yu , Chen Jia-Qi , Zhang Kai-Yang , Lu Xiang-Yu , Zhao Yue , Sun Wei-Yin
Published: January 2024

Two Cu(ii) assemblies were constructed, and the relationship between the structure/coordination environment and photocatalytic CO2 reduction under visible-light irradiation was explored.
Quantitative mass spectrometry imaging: therapeutics & biomolecules
Authors: Holbrook Joseph H. , Kemper Gabrielle E. , Hummon Amanda B.
Published: January 2024

In this feature article, we discuss quantitative mass spectrometry imaging of therapeutics and biomolecules conducted by recent studies for matrix-assisted laser desorption/ionization (MALDI) and desorption electrospray ionization (DESI) techniques.
Cu and Zn promoted Al-fumarate metal organic frameworks for electrocatalytic CO2 reduction
Authors: Dieu Thuy Ung Thi , Huan Tran Ngoc , Zanna Sandrine , Wilson Karen , Lee Adam F. , Le Ngoc-Diep , Mensah Jim , Dasireddy Venkata D. B. C. , Liem Nguyen Quang
Published: January 2024

Metal organic frameworks (MOFs) are attractive materials to generate multifunctional catalysts for the electrocatalytic reduction of CO2 to hydrocarbons.
Investigation into the intersection between response process validity and answer-until-correct validity: development of the repeated attempt processing issue detection (RAPID) method
Authors: Schreurs David G. , Trate Jaclyn M. , Srinivasan Shalini , Teichert Melonie A. , Luxford Cynthia J. , Schneider Jamie L. , Murphy Kristen L.
Published: January 2024

With the already widespread nature of multiple-choice assessments and the increasing popularity of answer-until-correct, it is important to have methods available for exploring the validity of these types of assessments as they are developed. This work analyzes a 20-question multiple choice assessment covering introductory undergraduate chemistry topics which was given to students in an answer-until-correct manner. Response process validity was investigated through one-on-one think-aloud interviews with undergraduate chemistry students. Answer-until-correct validity was also explored using an analysis of partial credit assignments. Results indicated the convenience of the quantitative partial credit method came at great cost to the precision of validity issue detection and is therefore not a valid shortcut to more rich qualitative approaches. The repeated attempt processing issue detection (RAPID) method is a novel method developed as a combination of response process and answer-until-correct validity. Results from this new method revealed validity issues that were undetected from the use of either approach individually or in concert.
The Potency of Locally Available Orange Peel Essential Oil as A Feed Additive to Improve Performances of Poultry
Authors: Widodo Eko
Published: January 2024

Indonesia as a tropical country has several orange varieties grown in the archipelago. The peel which contributes about 10 – 14% of the whole orange, is a potential waste to be utilized for making essential oil useful as an Antibiotic Growth Promoter (AGP) for poultry. Therefore, elaborative research is needed, because there are about 258 oranges from the genus citrus only. Since, many methods have been developed, to find a cheap method for the extraction of essential oil, and then protect the oil from evaporating before being implemented as a feed additive. Some foreign research on the use of orange peel essential oil shows prospective results. It is expected then, that the use of local orange peel essential oil will enable to replace the use of imported essential oil which is more expensive to the feed mills industry.
Effect of Moringa (Moringa oleifera) Flour on Physical and Chemistry Qualities of Duck Meat Traditional Crackers
Authors: Salsabila Dinda , Widati Aris Sri , Widyastuti Eny Sri
Published: January 2024

The low nutritional content of traditional crackers and typical taste of ordinary crackers is an opportunity to make crackers that have more nutritional value and have a delicious flavour. The aim of this research was to determine the effect of adding moringa flour (Moringa oleifera) on the quality of duck meat traditional crackers in terms of physical and chemical quality. Duck meat traditional crackers were added with moringa flour to improve taste and increase nutrition. The research treatments included P0 (control without adding moringa flour), P1 (addition of 1% moringa flour), P2 (addition of 2% moringa flour), and P3 (addition of 3% moringa flour). The results showed that moringa flour affected the swellability, organoleptic value, water content, fat content, protein content, ash content, crude fiber content, calcium, antioxidant activity and beta-carotene value of the cracker. However, the moringa flour did not affect the breaking strength. After carrying out the De Garmo test, the best treatment based on physicochemical and organoleptic was obtained by adding duck meat to crackers with a concrentration of 2% of addition.
“Egg Sell Points” A Chicken Eggs Marketing Strategy Based On Smart Farming System
Authors: Manurung Dian Khofifah , Firmansyah Richi Dwi , Satria Awang Tri , Putritamara Jaisy Aghniarahim
Published: January 2024

Post-COVID-19 in 2022, reported an increase in chicken egg consumption by 2.7 percent in Indonesia consumer’s. In 2021, the amount of eggs consumption was 18.92 Kg/Capita/year up to 20.02 Kg/capita/year in 2022. Estimated output consumption in 2023-2026 is estimated to grow by 1.16% per year. This condition is an excellent opportunity for laying hen farmers to maximize productivity and profits. However, generally the farmers still carry out the open house traditional farming system, its need to implement smart farming systems in the production process, and rely on one marketing channel. This paper is a review article and is collaborated with existing conditions in current laying hen farms. The first objective of this study is to overview the potential of laying hen farms using a smart farming system approach with the aim of farmers being able to diversify products with segmented distribution channels. The second is to build a segmented marketing network according to the product needs of each consumer. The expected result of this study is that farmers can maximize productivity and increase profits through segmented distribution channels. The innovation of this marketing system will be called ^Eggs sell points^ an integrated chicken egg marketing system through a sales point connected to the Internet of Things.
Intercostal Nerve Transfers to Native Triceps or Free Muscle Flaps for Elbow Extension in Brachial Plexus Injuries
Authors: Ferris Scott , Maciburko Simon
Published: January 2024

Intercostal nerve donors for traumatic brachial plexus injury reconstruction have been used to neurotize native muscles or free-functioning muscle transfers, with inconsistent outcomes reported. The aim was to record a substantial series, evaluate functional outcomes, and identify prognostic factors. We present a single-surgeon case series of 21 consecutive patients who underwent 21 transfer procedures to either native muscles or free-functioning muscles to reconstruct elbow extension over a 9-year period. Outcome parameters included target muscle power grade and timing of recovery. A Medical Research Council power grade ≥ M4 was achieved in 17 reconstructions. The free-functioning muscle group had significantly higher success rate and reached their best power grade 14 months earlier. Free-functioning muscle reconstruction with intercostal nerve transfer is a more complex procedure but has quicker functional recovery and greater reliability in achieving grade M4.
Cardiac Hemangioma in the Left Ventricular Septum
Authors: Ilcheva Lilly , Cholubek Magdalena , Loiero Dominik , Dzemali Omer
Published: January 2024

Background Primary cardiac tumors are an exceedingly rare benign group of tumors that may remain asymptomatic for a prolonged duration or could lead to significant clinical events.

Case Presentation A 64-year-old female patient underwent echocardiography prior to elective knee surgery due to the presence of palpitations and dyspnea. This revealed the existence of a mass located on the left side of the interventricular septum, which was resected successfully.

Conclusion Surgical resection represents the primary therapeutic approach for the management of cardiac hemangiomas. Failure to perform timely resection may elevate the risk of developing total atrioventricular block and experiencing sudden death.
Terahertz-induced second harmonic radiation from transient electron behavior in water
Authors: Zhao Hang , Tan Yong , Lu Guang , Wu Yijian , Liu Ming , Zhao Yuejin
Published: January 2024

Laser-induced liquid plasma is expected to be an efficient medium for a new generation of terahertz (THz) devices. However, the mechanism of interaction between liquid plasma and THz waves is currently unclear. Here, we observed two phenomena related to THz wave interaction with water plasma: THz-induced second harmonic (TISH) radiation in water plasma and THz absorption by water plasma. We established an internal relationship between these two macroscopic phenomena by utilizing a photocurrent model and the Drude model. Using liquid water and air as examples, a scheme is proposed to analyze the photonic characteristics of plasma in different physical states. This study offers an experimental basis for predicting the TISH phenomenon across various substances and states and also provides the theoretical support for the practical implementation of liquid-based detection of THz waves.
Harnessing vibrational resonance to identify and enhance input signals
Authors: Ashokkumar P. , Kabilan R. , Sathish Aravindh M. , Venkatesan A. , Lakshmanan M.
Published: January 2024

We report the occurrence of vibrational resonance and the underlying mechanism in a simple piecewise linear electronic circuit, namely, the Murali–Lakshmanan–Chua circuit, driven by an additional biharmonic signal with widely different frequencies. When the amplitude of the high-frequency force is tuned, the resultant vibrational resonance is used to detect the low-frequency signal and also to enhance it into a high-frequency signal. Further, we also show that even when the low-frequency signal is changed from sine wave to square and sawtooth waves, vibrational resonance can be used to detect and enhance them into high-frequency signals. These behaviors, confirmed by experimental results, are illustrated with appropriate analytical and numerical solutions of the corresponding circuit equations describing the system. Finally, we also verify the signal detection in the above circuit even with the addition of noise.
Infinite-memory classical wave-particle entities, attractor-driven active particles, and the diffusionless Lorenz equations
Authors: Valani R. N.
Published: January 2024

A classical wave-particle entity (WPE) can materialize as a millimeter-sized droplet walking horizontally on the free surface of a vertically vibrating liquid bath. This WPE comprises a particle (droplet) that shapes its environment by locally exciting decaying standing waves, which, in turn, guides the particle motion. At high amplitude of bath vibrations, the particle-generated waves decay very slowly in time and the particle motion is influenced by the history of waves along its trajectory. In this high-memory regime, WPEs exhibit hydrodynamic quantum analogs where quantum-like statistics arise from underlying chaotic dynamics. Exploration of WPE dynamics in the very high-memory regime requires solving an integrodifferential equation of motion. By using an idealized one-dimensional WPE model where the particle generates sinusoidal waves, we show that in the limit of infinite memory, the system dynamics reduce to a 3D nonlinear system of ordinary differential equations (ODEs) known as the diffusionless Lorenz equations (DLEs). We use our algebraically simple ODE system to explore in detail, theoretically and numerically, the rich set of periodic and chaotic dynamical behaviors exhibited by the WPE in the parameter space. Specifically, we link the geometry and dynamics in the phase-space of the DLE system to the dynamical and statistical features of WPE motion, paving a way to understand hydrodynamic quantum analogs using phase-space attractors. Our system also provides an alternate interpretation of an attractor-driven particle, i.e., an active particle driven by internal state-space variables of the DLE system. Hence, our results might also provide new insights into modeling active particle locomotion.
Describing geophysical turbulence with a Schrödinger–Coriolis equation in velocity space
Authors: de Montera Louis , Lehner Thierry , Mouhali Waleed , Nottale Laurent
Published: January 2024

In this paper, we examine the predictions of the scale-relativity approach for a turbulent fluid in rotation. We first show that the time derivative of the governing Navier–Stokes equation in the usual x-space can be transformed into a Schrödinger-like equation in velocity space with an external vectorial field to account for the rotation, together with a local velocity harmonic oscillator (VHO) potential in the v-space. The coefficients of this VHO are given by the second order x-derivatives of the pressure. We can then give formulas for the velocity and acceleration probability distribution functions (PDF). Using a simple model of anisotropic harmonic oscillator, we compare our predictions with relevant data from both direct numerical simulations (DNS) and oceanic drifter velocity measurements. We find a good agreement of the predicted acceleration PDF with that observed from drifters and some possible support in DNS for the existence of gaps in the local velocity PDF, expected in the presence of a Coriolis force.
Color center in
β
-Ga2O3 emitting at the telecom range
Authors: Stehr J. E. , Jansson M. , Pearton S. J. , McCloy J. S. , Jesenovec J. , Dutton B. L. , McCluskey M. D. , Chen W. M. , Buyanova I. A.
Published: January 2024

Transition metal (TM) ions incorporated into a host from a wide bandgap semiconductor are recognized as a promising system for quantum technologies with enormous potential. In this work, we report on a TM color center in β-Ga2O3 with physical properties attractive for quantum information applications. The center is found to emit at 1.316 μm and exhibits weak coupling to phonons, with optically addressable higher-lying excited states, beneficial for single-photon emission within the telecom range (O-band). Using magneto-photoluminescence (PL) complemented by time-resolved PL measurements, we identify the monitored emission to be internal 1E→3A2 spin-forbidden transitions of a 3d8 TM ion with a spin-triplet ground state—a possible candidate for a spin qubit. We tentatively attribute this color center to a complex involving a sixfold coordinated Cu3+ ion.
Shockwave velocimetry using wave-based image processing to measure anisotropic shock emission
Authors: Reuter Fabian , Mur Jaka , Petelin Jaka , Petkovsek Rok , Ohl Claus-Dieter
Published: January 2024

Noninvasive optical measurements of the shockwave propagation velocity using multiple pulse illumination allow deducing the shockwave pressure amplitude through Hugoniot relations and an appropriate equation of state of the medium. This technique is particularly useful for spatially resolved measurements near the shockwave emission site. Due to diffraction, however, a shockwave front can significantly change its morphology, rendering precise velocity measurements non-trivial. As solution we propose a wave front evolution (WaFE) velocimetry technique, which applies Huygens principle. We take a shadowgraph of the wave front at subsequent times as initial condition for the acoustic Helmholtz equation and numerically propagate the fronts in time. From the instance of time, when two subsequently taken wave front shadows numerically interfere and form one sharp wave front, the local shock velocity is obtained and the local shock pressure amplitude measured. With artificial test images, it is shown that this technique has excellent sub-pixel accuracy, robustness to noise, and can work with low contrast images and even overlapping and interfering wave fronts. The software is made available freely and can be applied to general shock front velocity measurements. We apply WaFE to determine the anisotropic shockwave emission from an elongated laser-induced plasma in water from shadowgraphs of the shockwave front imaged four times onto the same camera frame using multiple pulse illumination at a repetition rate of 60 MHz. The direction dependence of attenuation of the shockwave pressure amplitude is measured at distances of 50–300 μm to the plasma.
Hysteresis erasure in ZIF-8@ZnO nanorod array field-effect transistors through oxygen chemisorption-induced depolarization
Authors: Luan Pengyan , Yang Zhenxin , Liang Zheng , Li Xiaoliang , Chen Nan , Li Fushun , Li Xuanhe , Su Jiale , Lu Zheng-Hong , Zhu Qiang
Published: January 2024

Zeolitic imidazolate framework-8 (ZIF-8) is a versatile candidate for next-generation electronics owing to its adjustable lattice and physicochemical properties. However, the utilization of ZIF-8 for the fabrication of solid-state electronics and circuit components, such as field-effect transistors (FETs), has not been realized thus far, primarily due to ongoing debates surrounding its electrical properties. In this work, we fabricated n-type FETs using ZIF-8@ZnO nanorod arrays. A significant hysteresis behavior was observed. It was demonstrated that this hysteresis cannot be assigned to the well-established ferroelectric effect but rather to the polarization of ZIF-8, wherein the electric field of the gate aligns the dipole of 2-methylimidazole through molecular orientation rotation. It was clarified that the process of annealing in air can result in the chemisorption of oxygen on methylimidazole, leading to a limitation in the rotation of methylimidazole. This restriction ultimately causes the depolarization of ZIF-8, resulting in the erasure of hysteresis. This study unfolds the tunable hysteresis behavior of ZIF-8 and its sensibility to oxygen, thereby highlighting the potential applications of ZIF-8 in FETs, nonvolatile memories, and gas sensors.
Experimental and numerical investigation of flow dynamics in an upward bubbly flow in a tube undergoing oscillating rolling motion
Authors: Kim Myung Ho , Cho Hyoung Kyu , Kim Byoung Jae
Published: January 2024

Offshore nuclear power plants are characterized by a potential oscillatory motion depending on ocean waves. Investigating the local flow behavior in a system undergoing oscillating motion is necessary. In particular, because the local void fraction near the heating element surface significantly affects the nucleating boiling heat transfer and critical heat flux, understanding the dynamic behavior of the local void fraction is very important. Therefore, in this study, as an essential first step in predicting boiling heat transfer and departure from nucleate boiling in offshore nuclear reactors, the dynamic behavior of air–water bubbly flows has been experimentally and numerically investigated in a tube under oscillatory rolling conditions. An optical fiber Doppler probe was used to measure the local bubble parameters. The effects of the rolling period on the void fraction distributions, bubble sizes, and bubble velocities were insignificant. However, the rolling amplitude effect was significant. The void fraction was the highest at the downward-facing wall when the tube was at its maximum tilt. Moreover, the local water velocity became the highest when the tube returned to near vertical because of the combined effect of gravity and Euler force. These findings provide insights into understanding the characteristics of bubbly flow in a rolling tube.
Photonics-based all-dielectric horn antenna for millimeter waves in 5G and 6G applications
Authors: Ribeiro J. A. P. , Boas E. C. Vilas , Figueiredo F. A. P. , Mejía-Salazar J. R.
Published: January 2024

This work introduces a cost-effective photonics-based approach for fast-implementing horn antennas operating in millimeter-wave frequencies (mm-waves). Instead of using conventional metallic guiding structures, we employed an all-dielectric quarter-wave stack Bragg mirror photonic design. As a proof-of-concept, we used five semi-spherical air-polylactic acid bilayers stacked with a conical (horn-like) aperture fabricated through a one-step 3D printing process. The prototype, with a bandwidth of 2.6 GHz (from 24.96 to 27.50 GHz), was fed by the WR28 standard waveguide mechanism with measured gain ranging from 10.6 to 13.9 dBi (between 25 and 27 GHz). These outcomes demonstrate our idea's suitability for alternative design of high-frequency antennas for future 5G and 6G wireless communications systems, overcoming the precision constraints of traditional manufacturing methods.
Sensing the ocean electric fields via a self-supported CNT sponge
Authors: Chen Kai , Chen Yun , Li Haifan , Liu Jingshan , Song Sixuan , Huang Weibo , Yang Shaodian , Chen Nuofu , Gui Xuchun , Chen Jikun
Published: January 2024

A self-supported CNT sponge is composed of uniformly twisted CNTs with high aspect ratio that enables the large specific surface area and good carrier conduction to go beyond the conventional carbon-based materials, shedding light on its high electrochemical activity in salt water. Herein, we demonstrate the comparable performance of the CNT sponge as the electrode pair to the most commonly used Ag/AgCl for sensing underwater electric fields. The CNT sponge electrodes exhibit a high electrochemical reactivity in salt water with a low noise of ∼10 nV/rt(Hz)@100 Hz within a wide range of the electric field frequency (e.g., 10–105 Hz), while the frequency response approaches a constant magnitude across the same range of frequency. The performance of the CNT sponge electrodes in ocean electric field sensing is further verified by measuring the electrical signal response curve at various characteristic frequencies within a small water container, and also under a simulated source within the water pool. The high chemical stability and low costs of carbon-based CNT sponges pave the way to their potential applications.
Exploiting droplet impact-driven flows and jetting to guide and extract particles from particle-laden droplets
Authors: Lekshmi Bindhu Sunilkumar , Joseph Abel Paul , Varanakkottu Subramanyan Namboodiri
Published: January 2024

The low concentration of target particles in liquids necessitates their enrichment to a measurable level to provide precise and accurate analytical results. However, the enrichment and extraction of the adsorbed target particles from the droplets remains a challenge. The existing stimuli-responsive strategies for particle enrichment and extraction are not always desirable, as they depend on various parameters, including charge, dielectric constant, magnetic state, size of the particles, etc., which limits their applicability. An ideal method should be capable of extracting particles from the target droplet, irrespective of particle properties, and the process should be fast, preferably in an additive and electrode-free environment. This article presents an efficient strategy for realizing particle extraction based on droplet impact-driven fluid flows under isothermal, non-evaporative, and additive/electrode-free environments. The process relies on the droplet impact-driven redistribution of the particles at the liquid–air interface and the generation of a particle-rich satellite droplet at a designed Weber number, We ∼ 65. The impact dynamics and flow profiles are investigated using simulation and high-speed imaging, and the droplet impact-driven particle extraction is demonstrated experimentally. The particle extraction efficiency is estimated by weight percentage and optical profilometry analysis, and at optimal impact conditions, an extraction efficiency of about 90% is achieved, which takes only a few milliseconds to complete. The role of particle size, surface tension, and We on the extraction efficiency is investigated experimentally. Since the developed method is based on flows, it could be a potential candidate for the extraction/enrichment of various particles/biological entities and does not require complicated setups/skills.
On determining Navier's slip parameter at a solid boundary in flows of a Navier–Stokes fluid
Authors: Málek Josef , Rajagopal Kumbakonam R.
Published: January 2024

While the assumption of the “no-slip” condition at a solid boundary is unquestioningly applied to study the flow characteristics of a Navier–Stokes fluid, there was considerable debate among the early pioneers of fluid mechanics, Du Buat, Girard, Navier, Coulomb, Poisson, Prony, Stokes, and others, as to the proper condition that has to be met at a solid boundary due to a fluid, such as water flowing adjacent to the same. Contemporary usage of the no-slip boundary condition notwithstanding, in our previous study [Málek and Rajagopal, “On a methodology to determine whether the fluid slips adjacent to a solid surface,” Int. J. Non-Linear Mech. 157, 104512 (2023)], we outlined a methodology to test the validity of the assumption. In this study, we continue the investigation further by providing a scheme for determining the slip parameter that characterizes the extent of slip, if one presumes that Navier's slip boundary condition is satisfied. We find that depending on whether the volumetric flow rate is greater or less than the volumetric flow rate corresponding to the no-slip case, different scenarios present themselves regarding what transpires at the boundary.
Theoretical study on the interfacial instability of a spherical droplet subject to vertical vibration
Authors: Li Yikai , Zhu Ming , Wu Kun , Liu Dehua , Xi Ru
Published: January 2024

Interfacial instability would be aroused on a spherical liquid droplet when it is subject to external vertical vibration. In this paper, a linear analysis was conducted on this instability problem. The polar-angle dependent acceleration in the spherical coordinate is strongly coupled with the temporal and spatial component of the surface deformation displacement, which gives a recursion equation that implicitly expresses the dispersion relation between the growth rate and the spherical mode numbers. The unstable regions (or unstable tongues) for the inviscid fluids considering the latitudinal mode (longitudinal mode number m=0) were derived and presented in the parameter space. Compared to the solution of the spherical Faraday instability under radial vibration acceleration, the regions of harmonic unstable tongues for the mono-directional vibration cases become much narrower, and the subharmonic unstable tongues almost approach straight lines. The analysis shows that the latitudinal waves emerging on the spherical droplet surface ought to oscillate harmonically instead of subharmonically, which is opposite to the results for the case under radial vibration acceleration. A corresponding experiment of a liquid droplet lying on a vertically vibrating plate was conducted, and the observations substantiate our theoretical predictions.
Nontoxic, precious-metal-free titanium-based metallic glasses with exceptional glass-forming ability and high specific strength
Authors: Chen Lei , Thaiyanurak Tittaya , Wang Zhengming , Ayers Madeline , Zaitseva Natalia , Xu Donghua
Published: January 2024

Titanium-based metallic glasses (TBMGs) are attracting broad interest due to their simultaneous light weight, superhigh strength, and specific strength, exceptional wear- and corrosion-resistance and biocompatibility, desirable for electronic, biomedical, and aerospace applications. However, the glass-forming ability (GFA) of TBMGs, except some containing significant amount of toxic (Be) or precious (Pd, Ag) elements, is disappointingly low, as manifested by a critical casting diameter (dc) not more than 6 mm, which significantly restricts their manufacturing and applications. Here, we report our discovery of a series of TBMGs in the (TiZrHf)x(CuNi)y(SnSi)z pseudo-ternary system. These alloys possess an exceptionally large dc, reaching up to 12 mm, doubling the current record for Be and precious-metal free TBMGs. Moreover, these alloys exhibit a low density (7.0–7.3 g/cm3), high fracture-strength (up to ∼2700 MPa), high specific fracture-strength (up to ∼370 N m g−1), and even good plasticity with a plastic strain of up to 9.4% upon compression. They also possess high activation energy for crystallization and high atomic packing efficiency, which provide an initial physical account for their exceptional GFA and manufacturability.