bluuebunny/crossref_metadata_2025 huggingface dataset:
Ion-concentration-polarization-assisted photocatalytic reactor for highly efficient water purification
Authors: Wang Cong , Jeon Joa , Seo Eunseok , Park Jungyul
Published: June 2022

An ion-concentration-polarization-assisted photocatalytic reactor can enhance the water purification performance by inducing the nonlinear electric field that inhibits the recombination of photoexcited electrons and holes.
Highly accurate multiprotein detection on a digital ELISA platform
Authors: Yang Shih-Mo , Bi Qingbo , Zhang Wen Jun , Cui Xiaochuan , Zhou Ying , Yuan Cunyin , Cui Yubao
Published: June 2022

The emerging single-molecule detection platform digital enzyme-linked immunosorbent assay (ELISA) can detect numerous proteins simultaneously at serum concentrations as low as picograms per milliliter.
Recent advances in bimetallic metal–organic frameworks (BMOFs): synthesis, applications and challenges
Authors: Liu Si , Qiu Yuzhi , Liu Yafen , Zhang Wenfeng , Dai Zhong , Srivastava Devyani , Kumar Abhinav , Pan Ying , Liu Jianqiang
Published: June 2022

An overview on the recent progress in bimetallic MOFs regarding their design strategies, syntheses and multifarious applications.
Cis and trans platinum(ii) N-heterocyclic carbene isomers: synthesis, characterization and biological activity
Authors: Rivera Carolina , Bacilio-Beltrán Héctor A. , Puebla-Pérez Ana M. , Rangel-Salas Irma I. , Alvarado-Rodríguez José G. , Flores-Moreno Roberto , Velázquez-Juárez Gilberto , Peregrina-Lucano A. Aarón , Becerra-Martínez Elvia , Valdez-Ruvalcaba Jaime , Rubio José E. , Cortés-Llamas Sara A.
Published: June 2022

Cis- and trans-NHC-Pt(ii) isomers from the masked carbene 1,3-dimethylimidazolium-2-carboxylate: the relevance of isomerism in the biological activity.
Ultra-bright and narrow-band emission from Ag atomic sized nanoclusters in a self-assembled plasmonic resonator
Authors: Gritchenko Anton S. , Kalmykov Alexey S. , Kulnitskiy Boris A. , Vainer Yuri G. , Wang Shao-Peng , Kang Bin , Melentiev Pavel N. , Balykin Victor I.
Published: June 2022

We have proposed, implemented and investigated a novel, efficient narrow-band quantum emitter based on an atomic-sized Ag nanocluster in a plasmonic resonator.
Facile synthesis of ZIF-67 derived dodecahedral C/NiCO2S4 with broadband microwave absorption performance
Authors: Zhou Congyu , Yao Zhengjun , Wei Bo , Li Wenying , Li Zhejia , Tao Xuewei , Zhou Jintang
Published: June 2022

The dodecahedral structure formed by etching ZIF-67 and introducing NICo2S4 on the surface exhibits excellent microwave absorption performance.
Decoding microRNA drivers in atherosclerosis
Authors: Vartak Tanwi , Kumaresan Soundharya , Brennan Eoin
Published: June 2022

An estimated 97% of the human genome consists of non-protein-coding sequences. As our understanding of genome regulation improves, this has led to the characterization of a diverse array of non-coding RNAs (ncRNA). Among these, micro-RNAs (miRNAs) belong to the short ncRNA class (22–25 nucleotides in length), with approximately 2500 miRNA genes encoded within the human genome. From a therapeutic perspective, there is interest in exploiting miRNA as biomarkers of disease progression and response to treatments, as well as miRNA mimics/repressors as novel medicines. miRNA have emerged as an important class of RNA master regulators with important roles identified in the pathogenesis of atherosclerotic cardiovascular disease. Atherosclerosis is characterized by a chronic inflammatory build-up, driven largely by low-density lipoprotein cholesterol accumulation within the artery wall and vascular injury, including endothelial dysfunction, leukocyte recruitment and vascular remodelling. Conventional therapy focuses on lifestyle interventions, blood pressure-lowering medications, high-intensity statin therapy and antiplatelet agents. However, a significant proportion of patients remain at increased risk of cardiovascular disease. This continued cardiovascular risk is referred to as residual risk. Hence, a new drug class targeting atherosclerosis could synergise with existing therapies to optimise outcomes. Here, we review our current understanding of the role of ncRNA, with a focus on miRNA, in the development and progression of atherosclerosis, highlighting novel biological mechanisms and therapeutic avenues.
The intersection between circadian and heat-responsive regulatory networks controls plant responses to increasing temperatures
Authors: Laosuntisuk Kanjana , Doherty Colleen J.
Published: June 2022

Increasing temperatures impact plant biochemistry, but the effects can be highly variable. Both external and internal factors modulate how plants respond to rising temperatures. One such factor is the time of day or season the temperature increase occurs. This timing significantly affects plant responses to higher temperatures altering the signaling networks and affecting tolerance levels. Increasing overlaps between circadian signaling and high temperature responses have been identified that could explain this sensitivity to the timing of heat stress. ELF3, a circadian clock component, functions as a thermosensor. ELF3 regulates thermoresponsive hypocotyl elongation in part through its cellular localization. The temperature sensitivity of ELF3 depends on the length of a polyglutamine region, explaining how plant temperature responses vary between species. However, the intersection between the circadian system and increased temperature stress responses is pervasive and extends beyond this overlap in thermosensing. Here, we review the network responses to increased temperatures, heat stress, and the impacts on the mechanisms of gene expression from transcription to translation, highlighting the intersections between the elevated temperature and heat stress response pathways and circadian signaling, focusing on the role of ELF3 as a thermosensor.
Evaluating the Efficacy of a Smartphone App for Tinnitus Relief Using Behavioral and Brain Imaging Measures
Authors: Husain Fatima T. , Khan Rafay A. , Tai Yihsin , Shahsavarani Somayeh
Published: June 2022

Purpose:

In this exploratory, open-label study, we used behavioral and brain imaging measures to assess the effectiveness of a smartphone application (ReSound Relief app), which aims to help reduce tinnitus-related distress.

Method:

Fourteen participants with a wide range of tinnitus-related symptoms and who were not currently undergoing any external treatment participated. They completed the 6-month study and reported different levels of engagement with the app.

Results:

Across a range of tinnitus questionnaires, most participants showed either no change or decrease in tinnitus handicap. Resting-state and task-based functional magnetic resonance imaging (fMRI) data were collected at baseline and the end of the study. Resting-state fMRI of 12 participants revealed alterations in interregional connectivity of default mode, salience, emotion, auditory, and visual processing networks at the end of the intervention period compared to baseline. Ratings of affective sounds (as pleasant, neutral, or unpleasant) were assessed using fMRI, and comparison after 6 months of app usage revealed reduced activity in the left superior temporal gyrus (secondary auditory cortex), right superior occipital gyrus, and left posterior cingulate cortex. Our findings were not significant at a false discovery rate level of
p
< .05.

Conclusions:

The reported changes were not significant, possibly due to the small sample size, heterogeneity of the tinnitus handicap among subjects at the start of the project, and the length of the intervention period. Nevertheless, this study underscores the ease of usage of the app and the potential use of brain imaging to assess changes due to a passive, self-administered intervention for individuals with varying levels of tinnitus severity.
Inequity in Peer Review in Communication Sciences and Disorders
Authors: Girolamo Teresa M. , Castro Nichol , Fannin Danai Kasambira , Ghali Samantha , Mandulak Kerry
Published: June 2022

Purpose:

The American Speech-Language-Hearing Association (ASHA) has committed to advancing diversity, equity, and inclusion (DEI) by retaining and advancing Black, Indigenous, and people of color (BIPOC) individuals in the discipline of communication sciences and disorders (CSD), amid critical shortages of faculty to train the next generation of practitioners and researchers. Publishing research is central to the recruitment, retention, and advancement of faculty. However, inequity in peer review may systematically target BIPOC scholars, adding yet another barrier to their success as faculty. This viewpoint article addresses the challenge of inequity in peer review and provides some practical strategies for developing equitable peer-review practices. First, we describe the demographics of ASHA constituents, including those holding research doctorates, who would typically be involved in peer review. Next, we explore the peer-review process, describing how inequity in peer review may adversely impact BIPOC authors or research with BIPOC communities. Finally, we offer real-world examples of and a framework for equitable peer review.

Conclusions:

Inequity at the individual and systemic levels in peer review can harm BIPOC CSD authors. Such inequity has effects not limited to peer review itself and exerts long-term adverse effects on the recruitment, retention, and advancement of BIPOC faculty in CSD. To uphold ASHA's commitment to DEI and to move the discipline of CSD forward, it is imperative to build equity into the editorial structure for publishing, the composition of editorial boards, and journals content. While we focus on inequity in CSD, these issues are relevant to other disciplines.
An intelligent sliding mode control for stabilization of parallel converters feeding CPLs in DC‐microgrid
Authors: Mosayebi Mahdi , Gheisarnejad Meysam , Khooban Mohammad Hassan
Published: June 2022

The constant power loads (CPLs) threaten the stability of the DC microgrids (DCMGs) due to the negative impedance characteristic, which leads to voltage oscillations or a blackout in the DCMG. This paper proposes a new droop control for paralleled DC–DC converters feeding CPLs in the DCMG to improve the stability of the whole system. In this approach, an optimization droop gain is conducted for each converter to guarantee current sharing among paralleled converters. Furthermore, an intelligent single input interval type‐II fuzzy logic controller (SIT2‐FLC) is developed in a model‐free framework to further ameliorate the current sharing and voltage regulation in the DCMG when supplying the CPLs. An extended‐state observer (ESO) is adopted in the model‐free controller to estimate the unmodelled dynamics in the DC‐DC converters feeding CPLs. Since an estimation observer error often appears in the presence of uncertainties, a sliding mode control (SMC) technique is proposed to remove the estimation error and enhance the system stability. The studied DCMG is developed in hardware‐in‐the‐loop (HIL) with various levels of CPL's power to verify the applicability of the suggested mode‐free intelligent controller.
Investigating magnetic field inference from the spectral region around the Mg Ib2line using the weak-field approximation
Authors: Vukadinović D. , Milić I. , Atanacković O.
Published: June 2022

Context.The understanding of the magnetic field structure in the solar atmosphere is important in assessing both the dynamics and the energy balance of the solar atmosphere. Our knowledge about these magnetic fields comes predominantly from the interpretation of spectropolarimetric observations. Simpler approaches based on approximations such as the weak-field approximation (WFA) deserve special attention as key methods in the interpretation of large, high-resolution datasets.

Aims.We investigate the applicability of the WFA for retrieving the depth-dependent line-of-sight (LOS) magnetic field from the spectral region containing the Mg Ib2spectral line and two photospheric Ti I and Fe I lines in its wings.

Methods.We constructed and applied a 12-level model for Mg I atom that realistically reproduces theb2line profile of the mean quiet Sun. We tested the applicability of the WFA to the spectra computed from the FAL C atmospheric model with different magnetic and velocity fields added on an ad hoc basis . Then we extended the analysis to the spectra computed from two 3D magneto-hydrodynamic (MHD) MURaM simulations of the solar atmosphere. The first MHD cube was used to estimate the StokesVformation heights of each spectral line. These heights correspond to optical depths at which the standard deviation of the difference between the WFA-inferred magnetic field and the magnetic field in the MHD cube is minimal. The estimated formation heights were verified using the second MHD cube.

Results.The LOS magnetic field retrieved by the WFA is reliable for the magnetic field strength up to 1.4 kG even when moderate velocity gradients are present. The exception is the Fe I line, for which we found a strong discrepancy in the WFA-inferred magnetic fields because of the line blend. We estimated the StokesVformation heights of each spectral line to be: logτFe = −2.6, logτMg = −3.3, and logτTi = −1.8. We were able to estimate the LOS magnetic field from the MURaM cube at these heights with the uncertainty of 150 G for the Fe I and Ti I lines and only 40 G for the Mg Ib2line.

Conclusions.Using the WFA, we can quickly get a reliable estimate of the structure of the LOS magnetic field in the observed region. This offers a significant advantage in comparison with otherwise time-consuming classical spectropolarimetric inversions. We find that the Mg Ib2line profile calculated from the quiet Sun MURaM simulation agrees very well with the observed mean spectrum of the quiet Sun.
Multiscale entropy analysis of astronomical time series
Authors: Audenaert J. , Tkachenko A.
Published: June 2022

Context.The multiscale entropy assesses the complexity of a signal across different timescales. It originates from the biomedical domain and was recently successfully used to characterize light curves as part of a supervised machine learning framework to classify stellar variability.

Aims.We aim to explore the behavior of the multiscale entropy in detail by studying its algorithmic properties in a stellar variability context and by linking it with traditional astronomical time series analysis methods and metrics such as the Lomb-Scargle periodogram. We subsequently use the multiscale entropy as the basis for an interpretable clustering framework that can distinguish hybrid pulsators with bothp- and g-modes from stars with onlyp-mode pulsations, such asδScuti (δSct) stars, or from stars with onlyg-mode pulsations, such asγDoradus (γDor) stars.

Methods.We calculate the multiscale entropy for a set ofKeplerlight curves and simulated sine waves. We link the multiscale entropy to the type of stellar variability and to the frequency content of a signal through a correlation analysis and a set of simulations. The dimensionality of the multiscale entropy is reduced to two dimensions and is subsequently used as input to the HDBSCAN density-based clustering algorithm in order to find the hybrid pulsators within sets ofδSct andγDor stars that were observed byKepler.

Results.We find that the multiscale entropy is a powerful tool for capturing variability patterns in stellar light curves. The multiscale entropy provides insights into the pulsation structure of a star and reveals how short- and long-term variability interact with each other based on time-domain information only. We also show that the multiscale entropy is correlated to the frequency content of a stellar signal and in particular to the near-core rotation rates ofg-mode pulsators. We find that our new clustering framework can successfully identify the hybrid pulsators with bothp- andg-modes in sets ofδSct andγDor stars, respectively. The benefit of our clustering framework is that it is unsupervised. It therefore does not require previously labeled data and hence is not biased by previous knowledge.
Study on radius of influence of groundwater circulation well in the field experiment
Authors: Yuan Haowei , Qu Zhihui , Zhang Chaoyu , Jiang Yutong , Zhang Ying
Published: June 2022

In recent years, groundwater circulation wells (GCW) have gradually become a research hotspot as an In-situ remediation technology. This technology reduces the construction of gas phase extraction wells and saves underground space compared to the traditional Air sparging (AS) remediation technology, the remediation process involves both volatile removal and microbial degradation. This study fully combines the background conditions of an organic contamination site and designs a positive circulation airflow lift circulation well. By analyzing the diffusion law of chloride tracer with aeration time and the changes of water level and water pressure of the monitoring well, it is known that the influence radius of the circulation well can be stabilized at 5.00 m when the aeration volume is 10 L/min. It not only has an essential demonstration significance for the development of groundwater circulation well remediation technology, but also provides reference process parameters for subsequent applications in type site remediation engineering applications.
Variation in Urban Forest Regulation of Air Particulate Matter Concentration
Authors: Ma Fengfeng , Zhou Xiang , Deng Nan , Li Xiquan
Published: June 2022

Urban forest was vital to adjusting Air Particulate Matter Concentration (APMC). The purpose of this study was designed to provide a more detailed analysis of the urban forest long-time scales effect on APMC. The paper assessed effect of forests (urban greening) on APMC in an urban environment, where an urban green center (nearly 2 km2) and a nearby (5 km away) bare-ground site (at a road intersection) in Yuhua District of Changsha, China, were chosen to delve into daily, seasonal, and annual variation of APMC in an urban forest and a non-forested site respectively. It was found that: (1) on a daily basis, APMC in both the urban forest and the non-forested site was high in the morning and evening, but low at noon, demonstrating a “two-peak-one-trough” or V-shaped pattern. Additionally, APMC in the morning was higher than evening. (2) in terms of season, APMC was high in spring and winter, but low in summer and fall. (3) the annual change of the APMC showed a “bimodal” annual trend in urban forest and non-forested site, with a peak concentration in the urban forest coming later than the non-forested site. (4) temperature and average wind speed composed main factors affecting APMC in Changsha’s ecotope. The paper characterized the change pattern in APMC in urban environment (forested and non-forested), suggested appropriate recreational periods in the urban forest, and gave insight in planning and construction of urban greening projects.
Geochemical characteristics and ecological effects of Se and Zn in topsoil in Western Fuling of Chongqing
Authors: Mao Lingling , Tian Heming , Zhang Xiong , Zhang Ruigang , Luan Jinhua , Zhao Haitong , Hu Feng , Li Changchao , Luo Xu
Published: June 2022

A large area of soil in China is deficient in selenium (Se) and zinc (Zn)，meanwhile, Se and Zn are essential trace elements for human body, so it is of great significance to find Se and Zn rich soil to cultivate crops. Based on the data of Se and Zn in topsoil, crops and root soil obtained from 1:50000 land quality geochemical survey, this paper taking the western area of Fuling in Chongqing as the research area, studies the content and spatial distribution characteristics of Se and Zn in soil and crops, and analyzes the enrichment law of Se and Zn in agricultural crops. The results show that the average values of Se and Zn in the topsoil of the study area are 0.265mg/kg and 77.56mg/kg respectively. There are some differences in the contents of Se and Zn in different geological backgrounds, soil parent materials and soil types. The high value areas of Se and Zn are mainly distributed in the exposed areas of Triassic carbonate; in the study area, the average contents of Se and Zn in maize seeds are 0.029mg/kg and 20.752mg/kg respectively, and the enrichment rates are 96% and 82% respectively. The average contents of Se and Zn in rice seeds are 0.032mg/kg and 11.463mg/kg respectively, and the enrichment rates are 13.3% and 5% respectively. The bioaccumulation coefficients of Se and Zn in maize are higher than that in rice, and the availability of Se and Zn elements in maize root soil is higher.The results can provide geochemical basis for developing characteristic land resources, functional agriculture and promoting rural revitalization in Fuling District.
Global Dynamics and Reflections on Critical Minerals
Authors: Su Yina , Hu Dewen
Published: June 2022

Critical minerals refer to minerals that have an important strategic position in high-tech application and economic development such as national defense, military industry and emerging industry, but their resource security is at risk. In the context of a new round of technological revolution and industrial transformation, critical minerals have become the focus in the world competition. The United States, the European Union, Japan, Canada, Australia and China have released the lists of critical minerals respectively. Their lists have a high degree of coincidence. In terms of the demand and governance situation, the distribution areas of critical minerals are highly concentrated but their demand shows structural differentiation. Moreover, developed countries have great power but China has weak power in the global governance of critical minerals. In terms of improving the global governance capability, China needs to create the evaluation system for sustainable development of critical minerals, strengthen international cooperation, promote the reform of governance and enhance China’s voice in the word. Moreover, China should carry out the strategy of critical minerals reserves.
Surface Cranial Ultrasound: The Natural Heir to X-Ray for the Screening of Skull Deformities in Infants
Authors: Pogliani Laura Maria , Zuccotti Gian Vincenzo , Reggiori Maddalena , Erbetta Alessandra , Lacerenza Michele , Prada Francesco , Furlanetto Marika , Vetrano Ignazio Gaspare , Valentini Laura Grazia
Published: June 2022

Purpose Volumetric tomography (3D-CT) is currently considered the gold standard for the diagnosis of craniosynostosis, but its use as the first-line examination for cranial deformities is a topic of debate, because of skull X-ray radiation and low sensitivity and specificity. Cranial ultrasound is an emerging noninvasive radiation-free alternative, but its diagnostic accuracy still needs confirmation.

Materials and Methods The present prospective study included 350 infants with skull deformities, who underwent cranial ultrasound as the first-line examination, followed by 3D-CT if the echography results was positive or unclear. If the results were negative, infants underwent physical treatment and follow-up. To evaluate ultrasound reliability, we focused on cases that underwent both the index test and the gold standard and performed a double-blind comparison of the echography and 3D-CT results.

Results Ultrasound documented patent sutures in 293 infants and 9 had inconclusive results. The 293 ultrasound-negative infants were followed clinically: all improved, except 28 that underwent 3D-CT. In all of these cases, 3D-CT confirmed the ultrasonography results (no false negatives). 48 infants showed premature suture closure and underwent 3D-CT: 47 were confirmed (true positive), 1 was false positive. The sensitivity was 100%, the specificity was 99.7%, the positive and negative predictive values were 97.9% and 100%, respectively, the accuracy was 99.7%, and the diagnostic test evaluation was conclusive.

Conclusion The study documented the high sensitivity and specificity of echography for the diagnosis of craniosynostosis in a referral center, with better results being achieved before 6 months of age. Major limitations are the loss of diagnostic significance as the child grows and the learning curve needed. The advantages are avoidance of radiation and chance to evaluate the brain at the same time.
Exploring the Impact of Using Patient-Specific 3D Prints during Consent for Skull Base Neurosurgery
Authors: Mian Shan Y. , Jayasangaran Shubash , Qureshi Aishah , Hughes Mark A.
Published: June 2022

Objectives Informed consent is fundamental to good practice. We hypothesized that a personalized three-dimensional (3D)-printed model of skull base pathology would enhance informed consent and reduce patient anxiety.

Design Digital images and communication in medicine (DICOM) files were 3D printed. After a standard pre-surgery consent clinic, patients completed part one of a two-part structured questionnaire. They then interacted with their personalized 3D printed model and completed part two. This explored their perceived involvement in decision-making, anxiety, concerns and also their understanding of lesion location and surgical risks. Descriptive statistics were used to report responses and text classification tools were used to analyze free text responses.

Setting and Participants In total,14 patients undergoing elective skull base surgery (with pathologies including skull base meningioma, craniopharyngioma, pituitary adenoma, Rathke cleft cyst, and olfactory neuroblastoma) were prospectively identified at a single unit.

Results After 3D model exposure, there was a net trend toward reduced patient-reported anxiety and enhanced patient-perceived involvement in treatment. Thirteen of 14 patients (93%) felt better about their operation and 13/14 patients (93%) thought all patients should have access to personalized 3D models. After exposure, there was a net trend toward improved patient-reported understanding of surgical risks, lesion location, and extent of feeling informed. Thirteen of 14 patients (93%) felt the model helped them understand the surgical anatomy better. Analysis of free text responses to the model found mixed sentiment: 47% positive, 35% neutral, and 18% negative.

Conclusion In the context of skull base neurosurgery, personalized 3D-printed models of skull base pathology can inform the surgical consent process, impacting the levels of patient understanding and anxiety.
Qualitative Study of Participant Impressions as Simulated Patients of MediLinker—A Blockchain-Based Identity Verification Application
Authors: Bautista John Robert , Usman Muhammad , Harrell Daniel Toshio , Desai Ishav , Holan Cole , Cowley Cody , Alexander Jeremiah , Hanson Ladd , Meyer Eric T. , Khurshid Anjum
Published: June 2022

Objective In this study, we obtained participants' views on using MediLinker—a blockchain-based identity verification and personal health information management application. We also gathered their views about the use of blockchain technology for controlling and managing personal health information, especially in the context of a global health crisis such as a pandemic.

Methods Online semistructured interviews were conducted with 29 simulated patients (i.e., avatars) who used MediLinker between February and May 2020. Interview data were analyzed qualitatively using a phenomenological approach to thematic analysis.

Results Most of the participants noted that they do not know what blockchain is nor understand how it works. Nonetheless, in the context of the study, they trust blockchain as a technology that can enhance data protection and privacy of their personal health information. Participants noted that MediLinker is a useful application that allows patients to easily input, share, and revoke personal health information. As a proof-of-concept application, participants also noted several issues and recommendations that can serve as points of improvement when developing subsequent versions of MediLinker. In the context of using MediLinker as part of a telemedicine system during a pandemic, participants noted that it facilitates social distancing, makes clinical transactions efficient and convenient, and enhances identity verification.

Conclusion In general, the findings lay the foundation for a user-centered approach in developing future iterations of MediLinker and other patient-facing blockchain-based health information technologies. Also, the findings provide important insights into how people perceive blockchain-based health information technologies, especially during a pandemic.
Chaotic dynamics of small-sized charged Yukawa dust clusters
Authors: Deshwal Priya , Yadav Mamta , Prasad Chaitanya , Sridev Shantam , Ahuja Yash , Maity Srimanta , Das Amita
Published: June 2022

In a recent work [Maity et al., Phys. Rev. E 102(2), 023213 (2020)] the equilibrium of a cluster of charged dust particles mutually interacting with screened Coulomb force and radially confined by an externally applied electric field in a two-dimensional configuration was studied. It was shown that the particles arranged themselves on discrete radial rings forming a lattice structure. In some cases with a specific number of particles, no static equilibrium was observed. Instead, angular rotation of particles positioned at various rings was observed. In a two-ringed structure, it was shown that the direction of rotation of the particles positioned in different rings was opposite. The direction of rotation was also observed to change apparently at random time intervals. A detailed characterization of the dynamics of small-sized Yukawa clusters, with a varying number of particles and different strengths of the confining force, has been carried out. The correlation dimension and the largest Lyapunov index for the dynamical state have been evaluated to demonstrate that the dynamics is chaotic. This is interesting considering that the charged microparticles have many applications in a variety of industrial processes.
Optothermal control of spin Hall nano-oscillators
Authors: Muralidhar Shreyas , Houshang Afshin , Alemán Ademir , Khymyn Roman , Awad Ahmad A. , Åkerman Johan
Published: June 2022

We investigate the impact of localized laser heating on the auto-oscillation properties of a 170 nm wide nano-constriction spin Hall nano-oscillators (SHNOs) fabricated from a NiFe/Pt bilayer on a sapphire substrate. A 532 nm continuous wave laser is focused down to a spot size of about 500 nm at a power ranging from 0 to 12 mW. Through a comparison with resistive heating, we estimate a local temperature rise of about 8 K/mW. We demonstrate reversible laser tuning of the threshold current, the frequency, and the peak power and find that the SHNO frequency can be tuned by up to 350 MHz, which is over three times more than the current tuning alone. Increasing the temperature also results in increased signal jitter, an increased threshold current, and a reduced maximum current for auto-oscillations. Our results open up for optical control of single SHNOs in larger SHNO networks without the need for additional voltage gates.
Determination of Al occupancy and local structure for β-(AlxGa1−x)2O3 alloys across nearly full composition range from Rietveld analysis
Authors: Bhattacharjee Jayanta , Sagdeo Archna , Singh S. D.
Published: June 2022

Al occupancy and local structure (bond lengths and bond angles) for monoclinic β-(AlxGa1−x)2O3 alloys, with Al compositions (x) up to 90%, have been determined from Rietveld refinement of x-ray diffraction data. An Al atom preferentially occupies an octahedron (Oh) atomic site in comparison with a tetrahedron (Td) atomic site. However, a sizable number of Td atomic sites, i.e., 20% for Al composition of 5%, remain occupied by Al atoms, which is found to increase sharply with Al composition. The Oh atomic sites are not fully occupied by Al atoms even for the Al composition of 90%. The lattice parameters (bandgap) of the β-(AlxGa1−x)2O3 alloy decrease (increase) linearly with Al composition, but a change in slope of the variation of both lattice parameters and bandgap is observed at around Al composition of 50%. The lattice is found to be distorted for Al compositions more than 50% as indicated by a large change in the bond angles. The lattice distortion is determined to be the origin for the observed change in slope of the variation of both lattice parameters and bandgap for a monoclinic β-(AlxGa1−x)2O3 alloy system. Our results provide an insight into the local structure of β-(AlxGa1−x)2O3 alloys, which are required to have better understanding of their physical properties.
The structure, electronic, and magnetic properties of PbRuO3 under hydrostatic pressure: A first-principles study
Authors: Yue Caixia , Zhang Wenying , Wang Min , Liu Jia , Zhang Jiamei , Hou Denglu
Published: June 2022

Density functional theory in the local spin density approximation is used to investigate the structural, electronic, and magnetic properties of PbRuO3 under hydrostatic pressure. The calculated results show that under hydrostatic pressure, the ground state of Pm3¯m PbRuO3 is a ferromagnetic metal. The covalent bond of Pb–O strengthens as hydrostatic pressure increases, the exchange splitting of up- and down-spin channels of Ru 4d t2g weakens, and the magnetic properties decrease. The calculated ground state of Pbnm PbRuO3 is a paramagnetic metal, which is consistent with the experimental results at P = 0 GPa. The ground state of Imma PbRuO3 has weak ferromagnetism, which is close to the experimental results at P = 0 GPa. The Pbnm–Imma phase transition occurs when passing the critical hydrostatic pressure. The main reason is the distortion of Pb2+ at the A-site, which changed the bond length of Pb–O and the covalent strength of Pb–O, affecting the electron occupation of Ru 4d and leading to the Pbnm–Imma phase transition.
Wall shear stress, pressure and heat flux fluctuations in compressible wall-bounded turbulence. II. Spectra, correlation and nonlinear interactions
Authors: Yu Ming , Liu Peng Xin , Fu Ya Lu , Tang Zhi Gong , Yuan Xian Xu
Published: June 2022

Wall shear stress, pressure, and heat flux are of significant importance in engineering applications. In this two-part study, we investigate the compressibility effects on wall shear stress, pressure, and heat flux fluctuations in compressible wall-bounded turbulence by exploiting direct numerical simulation databases. In Paper I, we primarily deal with the one-point statistics, whereas in this second part, we report the effects of compressibility on the frequency spectra, wavenumber-frequency spectra of these flow quantities, and the two-point cross-correlations between them. It is found that the scaling laws of the spectra at low and high frequencies are retained as those of incompressible flows, whereas the spectra intensities at mid frequencies increase with the enhancement of compressibility effects, which is identified to be related to the ever-predominating traveling wave packets. These wave packets are convected downstream at the same velocity of 0.87Ub as that of pressure fluctuations, higher than that of the streaky structures 0.65Ub (Ub the bulk velocity), and enhance the space and time cross correlation between wall shear stress, pressure, and heat flux fluctuations. By extracting the envelopes of the traveling wave packets and inspecting the time and space correlations between the envelopes and the streaky structures, we found that the emergence of traveling wave packets comes later than the streaky structures, both in time and space. Based on these observations, we provide a depiction of the physical processes regarding the formation and evolution of the traveling wave packets.
Electron accumulation and distribution at interfaces of hexagonal ScxAl1−xN/GaN- and ScxAl1−xN/InN-heterostructures
Authors: Ambacher O. , Yassine A. , Yassine M. , Mihalic S. , Wade E. , Christian B.
Published: June 2022

Electron charges and distribution profiles induced by polarization gradients at the interfaces of pseudomorphic, hexagonal ScxAl1−xN/GaN- and ScxAl1−xN/InN-heterostructures are simulated by using a Schrödinger–Poisson solver across the entire range of random and metal-face ScxAl1−xN-alloys, considering the transition from wurtzite to hexagonal layered crystal structure. In contrast to previous calculations of polarization-induced sheet charges, we use Dryer’s modern theory of polarization, which allows for consideration of the spontaneous polarization measured on ferroelectric ScxAl1−xN-layers. Because the sheet density of the electrons accumulating at the heterostructure interfaces can strongly depend both on the data set of the piezoelectric and structural coefficients and on the alloying region of the ScxAl1−xN-layers in which the transition from the wurtzite to the hexagonal layered crystal structure occurs, we have calculated the charge carrier sheet densities and profiles for three representative data sets and evaluated their relevance for devices. We predict electron sheet densities of (2.26±0.20)×1014cm−2 and (6.25±0.20)×1014cm−2 for all three sets of data for Ni/AlN/InN- and Ni/ScN/InN-heterostructures, respectively. We demonstrate that the polarization-induced interface charges of Ni/ScxAl1−xN/InN-heterostructures are always positive, tend to increase with increasing Sc-content, and can cause electron accumulations that lead to flooding of the triangular quantum wells at the semiconductor interface. We identify Ni/ScxAl1−xN/GaN-heterostructures with 0.13≤x≤0.19 as particularly promising candidates for the processing of energy-efficient high electron mobility transistors due to their missing or low mechanical strain and their large electron sheet densities between (4.11±0.20)×1013cm−2 and (6.37±0.20)×1013cm−2. Furthermore, we present simulation results of highly strained Ni/ScxAl1−xN/GaN-heterostructures for 0.81≤x≤1.0, which point to electron accumulations of up to (8.02±0.40)×1014cm−2. These heterostructures are not suitable for transistor devices, but they may be of great interest for the implementation of low impedance contacts.
Development of slurry targets for high repetition-rate x-ray free electron laser experiments
Authors: Smith Raymond F. , Rastogi Vinay , Lazicki Amy E. , Gorman Martin G. , Briggs Richard , Coleman Amy L. , Davis Carol , Singh Saransh , McGonegle David , Clarke Samantha M. , Volz Travis , Hutchinson Trevor , McGuire Christopher , Fratanduono Dayne E. , Swift Damian C. , Folsom Eric , Bolme Cynthia A. , Gleason Arianna E. , Coppari Federica , Ja Lee Hae , Nagler Bob , Cunningham Eric , Heimann Philip , Kraus Richard G. , Rudd Robert E. , Duffy Thomas S. , Eggert Jon H. , Wicks June K.
Published: June 2022

Combining an x-ray free electron laser with a high-power laser driver enables the study of equations-of-state, high strain-rate deformation processes, structural phase transitions, and transformation pathways as a function of pressure to hundreds of GPa along different thermodynamic compression paths. Future high repetition-rate laser operation will enable data to be accumulated at >1 Hz, which poses a number of experimental challenges, including the need to rapidly replenish the target. Here, we present a combined shock compression and an x-ray diffraction study on epoxy (50% vol.)-crystalline grains (50% vol.) slurry targets, which can be fashioned into extruded ribbons for high repetition-rate operation. For shock-loaded NaCl-slurry samples, we observe pressure, density, and temperature states within the embedded NaCl grains consistent with observations from shock-compressed single-crystal NaCl.
Observation of conformational dynamics in single light-harvesting proteins from cryptophyte algae
Authors: Moya Raymundo , Norris Audrey C. , Spangler Leah C. , Scholes Gregory D. , Schlau-Cohen Gabriela S.
Published: June 2022

Photosynthetic organisms use pigment–protein complexes to capture the sunlight that powers most life on earth. Within these complexes, the position of the embedded pigments is all optimized for light harvesting. At the same time, the protein scaffold undergoes thermal fluctuations that vary the structure, and, thus, photophysics, of the complexes. While these variations are averaged out in ensemble measurements, single-molecule spectroscopy provides the ability to probe these conformational changes. We used single-molecule fluorescence spectroscopy to identify the photophysical substates reflective of distinct conformations and the associated conformational dynamics in phycoerythrin 545 (PE545), a pigment–protein complex from cryptophyte algae. Rapid switching between photophysical states was observed, indicating that ensemble measurements average over a conformational equilibrium. A highly quenched conformation was also identified, and its population increased under high light. This discovery establishes that PE545 has the characteristics to serve as a photoprotective site. Finally, unlike homologous proteins from the evolutionarily related cyanobacteria and red algae, quenching was not observed upon photobleaching, which may allow for robust photophysics without the need for rapid repair or replacement machinery. Collectively, these observations establish the presence of a rich and robust set of conformational states of PE545. Cryptophytes exhibit particularly diverse energetics owing to the variety of microenvironments in which they survive, and the conformational states and dynamics reported here may provide photophysical flexibility that contributes to their remarkable ability to flourish under diverse conditions.
Microwave-ignited DC-plasma ejection from basalt: Powder-generation and lightning-like effects
Authors: Shoshani Yoav , Jerby Eli
Published: June 2022

A phenomenon of dusty plasma ejected from basalt is presented, in the form of a stable, long-lived fire-pillar, solely sustained by a direct-current (DC) supply. The plasma is emitted to the air atmosphere from a molten hotspot, initially created in the basalt rock by localized microwave-heating (LMH). After an LMH-to-DC transition, the plasma column is solely sustained as a fire-pillar of ∼2 cm diameter, ∼4-cm height using a DC supply of ∼0.2 kV, ∼5 A, steadily lasting for periods longer than 3 min. The dusty-plasma products, accumulated in a powder form, consist of micro- and nanoparticles of basalt's components, including oxides of Si, Na, Fe, P, K, Mg, and Ti. The experimental conditions for the DC sustainability of basalt's dusty-plasma column are analyzed by various theoretical estimates. A possible relevance of these laboratory observations is attributed to atmospheric fire-pillar-like effects, associated, for instance, with volcanic-, ball-lighting, and lunar dusty-plasma phenomena. A potential application, utilizing this effect of DC-sustained dusty-plasma columns, is proposed for the direct extraction of mineral powders from rocks.
Improving sound absorption via coupling modulation of resonance energy leakage and loss in ventilated metamaterials
Authors: Gao Yong-xin , Li Zheng-wei , Liang Bin , Yang Jing , Cheng Jian-chun
Published: June 2022

Achieving broadband sound absorption in two-port open ducts is of fundamental importance in the acoustics, with wide applications ranging from noise control to duct sound mitigation. Yet the existing metamaterial designs are usually based on the use of Helmholtz-type cavities, posing limitations on the resulting absorption performance. Here, we propose and experimentally demonstrate a mechanism that uses coupling modulation of the resonance energy leakage and loss in ventilated metamaterials to realize optimal sound absorption. We design a slit-type unit cell as a practical implementation of the proposed mechanism and analytically prove its potential to obtain the desired leakage and loss factors simultaneously by properly adjusting the structural parameters. We benchmark our designed metamaterial with a conventional Helmholtz resonator-based design to demonstrate its advantage of sound absorption. Good agreement is observed between the theoretical predictions and experimental measurements. Our strategy represents a paradigm extending beyond classical models and opens up possibility for the design of high-efficiency acoustic absorbing devices and their applications in diverse scenarios especially broadband duct noise muffling.
Explicit series solutions for supersonic flat-plate boundary layer flows
Authors: Liu Ling , Li Jing , Liao Shijun
Published: June 2022

This paper describes explicit series solutions for supersonic flat-plate boundary layer flows that are convergent in the whole spatial domain for Mach numbers of up to 50. These series solutions are achieved by means of the homotopy analysis method (HAM), an analytic technique for highly nonlinear problems. Unlike the analytic approximations given by perturbation methods or other approaches, our explicit series solutions are guaranteed to converge with arbitrary physical parameters because of the so-called “convergence-control parameter” in the HAM framework. Explicit analytic expressions for the local surface skin-friction coefficient and the local heat-transfer coefficient of the supersonic boundary layer flow are also derived. These analytical solutions are found to be in perfect agreement with the corresponding numerical results, allowing the effects of physical parameters on supersonic boundary layer flows to be discussed in detail. The explicit series solutions described in this paper provide a benchmark for supersonic flat-plate boundary layer flows with Mach numbers in the range 0.8≤Ma≤50. To the best of our knowledge, no such explicit series solutions for supersonic flat-plate boundary layer flows have previously been reported. To enable relevant applications, a corresponding Mathematica package is provided to enable convenient access to explicit series solutions for supersonic flat-plate boundary layer flows.
MicroRNA expression in male infertility
Authors: Burgos C. F. , Cikutovic R. , Alarcón M.
Published: June 2022

Male infertility is a multifactorial disorder that involves different physiopathological mechanisms and multiple genes. In this sense, we analyse the role of miRNAs in this pathology. Gene expression analysis can provide relevant information to detect biomarkers, signalling pathways, pathologic mechanisms, and potential therapeutic targets for the disease. In this review, we describe four miRNA microarrays related to patients who present infertility diseases, including azoospermia, asthenozoospermia, and oligoasthenozoospermic. We selected 13 miRNAs with altered expressions in testis tissue (hsa-miR-122-5p, hsa-miR-145-5p, hsa-miR-16-5p, hsa-miR-193a-3p, hsa-miR-19a-3p, hsa-miR-23a-3p, hsa-miR-30b-5p, hsa-miR-34b-5p, hsa-miR-34c-5p, hsa-miR-374b-5p, hsa-miR-449a, hsa-miR-574-3p and hsa-miR-92a-3p), and systematically examine the mechanisms of four relevant miRNAs (hsa-miR-16-5p, hsa-miR-19a-3p, hsa-miR-92a-3p and hsa-miR-30b-5p) which we found that regulated a large number of proteins. An interaction network was generated, and its connections allowed us to identify signalling pathways and interactions between proteins associated with male infertility. In this way, we confirm that the most affected and relevant pathway is the PI3K-Akt signalling.