bluuebunny/crossref_metadata_2025 huggingface dataset:
Polycystic Ovary Syndrome and Metabolic Syndrome: Clinical and Laboratory Findings and Non-Alcoholic Fatty Liver Disease Assessed by Elastography
Authors: Lavor Claruza Braga Holanda , Viana Júnior Antonio Brazil , Medeiros Francisco das Chagas
Published: May 2022

Objective To evaluate the association between polycystic ovary syndrome (PCOS) and metabolic syndrome (MetS), adding liver assessment through elastography and ultrasound, for correlation with non-alcoholic fatty liver disease (NAFLD). Metabolic syndrome occurs in ∼ 43% of women with PCOS, and NAFLD is the hepatic expression of MetS.

Methods One hundred women, 50 with PCOS and 50 controls, matched by age (18–35 years) and body mass index (BMI) were included, restricted to patients with overweight and obesity grade 1, at the Assis Chateaubrian Maternity School, Universidade Federal do Ceará, Brazil. For the diagnosis of PCOS, we adopted the Rotterdam criteria, and for the diagnosis of MetS, the criteria of the National Cholesterol Education Program (NCEP/ATP III). Hepatic elastography and ultrasound were performed to assess liver stiffness and echotexture, respectively.

Results The average ages were 29.1 (±5.3) and 30.54 (±4.39) years, for the PCOS and the control group, respectively. Patients with PCOS had a risk 4 times higher of having MetS, odds ratio (95% confidence interval) = 4.14, than those in the control group. Women with PCOS had higher average of abdominal circumference (100.9 ± 9.08 cm vs 94.96 ± 6.99 cm) and triglycerides (162 ± 54.63 mg/dL vs 137.54 ± 36.91 mg/dL) and lower average of HDL cholesterol (45.66 ± 6.88 mg/dL vs 49.78 ± 7.05 mg/dL), with statistically significant difference. Hepatic steatosis was observed on ultrasound in women with PCOS; however, with no statistically significant difference. There was no change to NAFLD at elastography in any group.

Conclusion Women with PCOS had 4-fold higher frequency of MetS and more hepatic steatosis, with no statistically significant difference. There was no change in liver stiffness between the groups at elastography. The results can be extended only to populations of overweight and obesity grade 1, with PCOS or not. They cannot be generalized to other untested groups.
Utilization of Telestroke Prior to and Following the COVID-19 Pandemic
Authors: Turner Ashby C. , Etherton Mark R.
Published: May 2022

For over two decades, telestroke has been utilized as a means for improving acute access to a stroke specialist when this expertise is otherwise unavailable. During this time, telestroke use has increased and improvements in care metrics have been widely reported. Several telestroke model variations are utilized; each has different workflow implications. A successful telestroke system should include adequate protocols and training, equipment, documentation system, and tracking of quality metrics. Upfront costs of needed technology and devices, credentialing hurdles, and limited reimbursement are all reported barriers to the utilization of telestroke. Emphasis on safety measures during the COVID-19 pandemic resulted in the dramatic upscaling of telehealth utilization, although overall stroke volumes declined in many areas in the early phases of the pandemic. Going forward, continued reduction in cost of required devices and broadband connections, increased use of automated and advanced analytical software, and a universal licensing and credentialing system are needed to continue the expansion of telestroke use.
Telehealth for Comprehensive Care of Acute Neurologic Disorders
Authors: Matiello Marcelo , Cohen Adam B.
Published: May 2022

A teleneurology hospitalist model aims to address the demand for high-quality neurologic acute care and the shortage of neurologists. Here, we review concepts and models of teleneurology services to address access and care gaps in neurology beyond telestroke models. The goal of these emergent teleservices is to empower community hospitals to deliver the highest quality care, while also reducing unnecessary patient transfers to tertiary care hospitals. We highlight the clinical models, patient populations, and innovative approaches of different tele-neurohospitalist services. This includes challenges related to clinical limitations, legal issues, and reimbursement. We highlight specific areas of research that can further clarify and refine the appropriate use, cost-effectiveness, and clinical outcomes of these telemedicine-based care models.
Cognitive Behavioral Therapy in Endometriosis, Psychological Based Intervention: A Systematic Review
Authors: Donatti Lilian , Malvezzi Helena , Azevedo Bruna Cestari de , Baracat Edmund Chada , Podgaec Sergio
Published: May 2022

Introduction Endometriosis is an inflammatory disease that affects women of reproductive age, causing pain and the possibility of infertility. Endometriosis was associated to low life quality and research shows the impact of endometriosis in several areas of life, justifying how these patients are more likely to develop depression, anxiety, and stress.

Objective The aim of the present systematic review was to explore the field of psychology in endometriosis, identifying studies that used the cognitive behavioral therapy technique as a treatment for endometriosis and chronic pelvic pain.

Methods The keywords used were Endometriosis and Behavioral Therapy; Behavioral Disciplines and Activities; Cognitive Behavioral Therapy; Mental Health; Psychological Techniques; Psychology; Psychotherapy; Mental Health Services; and the search was performed in the following databases: PubMed/Medline, Scielo, Lilacs, and Capes. The study followed the PRISMA guidelines and all studies whose intervention strategy used was related to cognitive-behavioral therapy were considered.

Results Of the 129 articles found, only 5 were selected, and it was possible to identify that the psychological intervention whose approach brought cognitive-behavioral therapy techniques promoted a decrease in the sensation of pain, improvements in the scores of depression and stress, and significant changes in aspects of quality of life such as vitality, physical and social functioning, emotional well-being, control, and autonomy.

Conclusion Cognitive-behavioral therapy can be very promising to take care of the emotional side of those who have endometriosis However, the present systematic review highlights the need to develop more structured studies with consistent, clear and replicable methods to reach a psychological intervention protocol for patients who live with this gynecological-physical-emotional condition.
Primary Central Nervous System Angiitis Mimicking a Space-Occupying Lesion
Authors: Gandham Edmond Jonathan , Patel Bimal , Mathew Vivek , Raju Krishna Prabhu
Published: May 2022

Background and Purpose Intracranial space-occupying lesions are a sine qua non for neoplastic lesions; however, occasionally non-neoplastic lesions mimic neoplastic lesions, leading to diagnostic dilemmas. We report our experience with three patients who presented with a progressive hemispheric syndrome and the diagnostic considerations involved in the cases.

Materials and Methods In this retrospective study, we included three patients with primary angiitis of central nervous system (PACNS) who underwent craniotomy and biopsy, suspecting it to be mass lesions. Demographic features, clinical features, radiological features, histopathology, treatment, and clinical outcomes were studied.

Results Majority were males. The male:female ratio was 2:1. Lobar involvement was common. MR brain with contrast showed features of high-grade glioma. Despite hemispheric involvement, there was no mass effect. Perilesional edema was seen in all cases. All underwent craniotomy and biopsy; histopathology was consistent with PACNS. All patients were treated with corticosteroids and cyclophosphamide. Rituximab was used in addition to cyclophosphamide in one patient. At 2 years follow-up, two patients were in disease remission and one patient died due to disease progression.

Conclusion PACNS has a protean clinical manifestation. A high index of suspicion is required in cases with atypical clinical presentations, radiological features, and normal angiograms. Early histological diagnosis and aggressive immunotherapy with high-dose corticosteroids combined with intravenous cyclophosphamide yields favorable outcomes.
Adjunctive Benefit of High-Field 3 Tesla MRI Guidance in Endoscopic Transsphenoidal Resection of Pituitary Adenoma
Authors: Multani Kartik Manoj , Balasubramaniam Anandh , Rajesh Boyina Jagadeshwar , Kumar Krishna , Manohar Nitin , Kumar Anjani
Published: May 2022

Introduction Pituitary adenomas (PAs) although benign, are difficult to resect intracranial tumors and their residues are associated with morbidity and reduced quality of life. Thus, gross total resection (GTR) is the goal for all PAs. Role of various modalities for better intraoperative visualization and thus improve resection of adenoma have been tested and each have their pros and cons. The aim of this paper is to analyze adjunctive benefit of high-field 3 Tesla intraoperative magnetic resonance imaging (iMRI) in PAs resection by endoscopic transnasal transsphenoidal surgery (eTSS).

Materials and Methods A total of 50 patients who underwent iMRI-guided eTSS were included. MRI findings in preoperative, intraoperative, and 3 months postoperative stage were compared. Adjunctive value of iMRI in improving resection rates of adenoma, postoperative endocrinological outcomes, need for adjuvant radiotherapy, and postoperative cerebrospinal fluid leak rates was assessed.

Results High-field 3 Tesla iMRI helped us to detect residues in 24 (48%) patients and iMRI-guided second look surgery increased our GTR rates from initial 52 to 80% and also helped us to identify and achieve 100% GTR in intrasellar residues and parasellar residues that were medial to medial carotid tangential line. With better resection rates, need for adjuvant radiotherapy was also reduced and only 2% received adjuvant radiotherapy. Average increase in surgical time with the use of iMRI was 38.78 minutes without any side effects pertaining to prolonged surgery.

Conclusion High-field iMRI is a useful adjunct in assessment and improvement in extent of resection of PA by endoscopic transsphenoidal surgery. Also, it was found beneficial in preserving normal anatomical gland and, thus, reducing the need for postoperative adjuvant hormonal and radiation therapy.
The Correlation between Chlamydia Trachomatis and Female Infertility: A Systematic Review
Authors: Passos Laura Gazal , Terraciano Paula , Wolf Nicole , Oliveira Fernanda dos Santos de , Almeida Isabel de , Passos Eduardo Pandolfi
Published: May 2022

The impact of Chlamydia trachomatis (CT) infection on female's fertility is not completely established yet, since the level of evidence associating these factors is still weak. Hence, the goal of the present review is to contribute to a better elucidation of this matter. The electronic database chosen was the Medline/PubMed, with the last survey on May 11, 2021. Publication date was used as a filter, with the previous 5 years having been selected. The following describers were used: chlamydia trachomatis AND infertility; chlamydia trachomatis AND tubal alteration AND infertility; chlamydia AND low pregnancy rates. From the 322 studies screened, 293 that failed to meet our eligibility criteria were excluded. Subsequently, we removed seven studies for not having the possible correlation between CT infections and female infertility as its main focus, and three for being about sexually transmitted infections (STIs) in general. Moreover, two studies designed as reviews were also excluded. Ergo, we included 17 studies in our qualitative analysis. The authors conducted research individually and analyzed carefully the studies selected. As we retrieved the information needed for our study through reading the texts, no contact was made with the authors of the studies selected. This systematic review corroborates the hypothesis that CT infection potentiates female infertility, as 76.47% of the included studies found a positive correlation between them. We conclude that there is an important association between CT infection and female infertility. Ergo, making CT screening part of the infertility investigation routine is relevant and has a reasonable justification.
Impact of a Potential 20-Week Abortion Ban on Likelihood of Completing Required Views in Second-Trimester Fetal Anatomy Ultrasound
Authors: Henkel Andrea , Beshar Isabel , Cahill Erica P. , Blumenfeld Yair J. , Chueh Jane , Shaw Kate A.
Published: May 2022

Objective The aim of this study was to quantify the likelihood of assessing all mandated fetal views during the second-trimester anatomy ultrasound prior to the proposed federal 20-week abortion ban.

Study Design Retrospective cohort study of a random sample of 1,983 patients undergoing anatomy ultrasound in 2017 at a tertiary referral center. The difference in proportion of incomplete anatomic surveys prior compared with after 20-week gestation was analyzed using X
2 and adjusted logistic regression; difference in mean days elapsed from anomaly diagnosis to termination tested using t-tests and survival analysis.

Results Incomplete views were more likely with initial ultrasound before 20 weeks (adjusted relative risk: 1.70; 95% confidence interval: 1.50–1.94); 43.5% versus 26.1% were incomplete before and after 20 weeks, respectively. Fetal structural anomalies were identified in 6.4% (n = 127/1,983) scans, with 38.0% (n = 49) identified at follow-up after initial scan was incomplete. 22.8% (n = 29) with an anomaly terminated.

Conclusion A complete assessment of fetal views during an anatomy ultrasound prior to 20-week gestation is often not technically feasible. Legislation limiting abortion to this gestational age would greatly impact patient's ability to make informed choices about their pregnancies.

Key Points
A social networks-driven approach to understand the unique alcohol mixing patterns of tuberculosis patients: reporting methods and findings from a high TB-burden setting
Authors: Nagarajan Karikalan , Palani Bharathidasan , Basha Javeed , Jayabal Lavanya , Muniyandi Malaisamy
Published: May 2022

Individuals who consume alcohol have a higher chance of contracting tuberculosis (TB) due to their social mixing patterns. We aimed to study the social mixing patterns of TB patients who consume alcohol on a regular basis using a quantitative social network approach. In a high-TB prevalence context in India, a social network survey of 300 newly diagnosed pulmonary drug-sensitive TB patients was done. The survey found 52 (17%) male TB patients who shared alcohol on a regular basis with 106 (4%) of their first-degree social contacts. Alcohol sharing happened in 16 neighborhood venues. When compared to contacts who did not use alcohol, a higher proportion of contacts with regular alcohol use were diagnosed with TB (12.3%; 95% CI: 6.6–20.00 vs. 3.5%; 95% CI: 2.8–4.3). Social network analysis showed that the network consisting of patients and contacts was less dense and less connected (with density ratio of 0.009, and degree centrality of 1.3, and betweenness centrality of 0.5), indicating weaker transmission potential of the network. Comparatively the network consisting of patients, contacts and their alcohol sharing venues was more dense and more connected (with density ratio of 0.018, higher degree centrality of 3.1 and betweenness centrality of 154.2) indicating stronger transmission potential of the network. Regular alcohol sharing in four venues created a giant network component, that linked a higher proportion of contacts without TB (72.3%) to a higher proportion of TB patients (67.3%) and their contacts with TB (38.4%). When examined from a network perspective, the pooled TB transmission exposure of contacts with regular alcohol use grew by a factor of 10, which helped explain the unfavorable social mixing of patients and contacts with regular alcohol use.
Multiscale modeling of electrospray ion emission
Authors: Petro Elaine M. , Gallud Ximo , Hampl Sebastian K. , Schroeder Madeleine , Geiger Carl , Lozano Paulo C.
Published: May 2022

A multi-scale approach to electrospray ion source modeling has been developed. The evolution of a single-emitter electrospray plume in a pure ionic regime is simulated with a combination of electrohydrodynamic fluids and n-body particle modeling. Simulations are performed for the ionic liquid, EMI-BF4, firing in a positive pure-ion mode. The metastable nature of ion clusters is captured using an ion fragmentation model informed by molecular dynamics simulations and experimental data. Results are generated for three operating points (120, 324, and 440 nA) and are used to predict performance relevant properties, such as the divergence angle and the extractor surface impingement rate. Comparisons to experimental data recorded at similar operating points are provided.
On the terahertz response of metal-gratings on anisotropic dielectric substrates and its prospective application for anisotropic refractive index characterization
Authors: Jia Wei , Lou Minhan , Gopalan Prashanth , Bhattacharyya Arkka , Krishnamoorthy Sriram , Sensale-Rodriguez Berardi
Published: May 2022

This paper discusses the terahertz electromagnetic response of metallic gratings on anisotropic dielectric substrates. The metallic gratings consist of parallel gold stripes. Utilizing numerical simulations, we observe that it is possible to excite a series of resonant modes in these structures. These modes are affected differently by the different indices on the anisotropic substrate. An analytical model is discussed to show that modes associated with transmission peaks are due to the excitation of (a) Fabry–Pérot modes with polarization along the grating and/or (b) waveguide modes with polarization perpendicular to the grating. It is observed that the resonance associated with the TM1,1 mode is a narrow linewidth resonance which, in some particular circumstances, becomes nearly independent of substrate thickness. Therefore, from the spectral position of this resonance, it is possible to extract the out-of-plane component of the substrate refractive index with very small uncertainty. Based on this observation, we demonstrate the refractive index characterization of several lossless semiconductor substrates through frequency-domain polarized terahertz transmission measurements in the frequency range of 0.2–0.6 THz at normal incidence. The reliability of the technique is demonstrated on well-known materials, such as high-resistivity silicon and sapphire substrates. This technique is also applied for the characterization of a Fe-doped β-Ga2O3 single-crystal substrate.
Incipient fault diagnosis for the cam-driven absolute gravimeter
Authors: Hu Ruo , Feng Jinyang , Mou Zonglei , Yin Xunlong , Li Zhenfei , Ma Hongrong
Published: May 2022

The vibration disturbance caused by incipient faults is an important factor affecting the measurement accuracy of the cam-driven absolute gravimeter. Based on the characteristics of the cam-driven absolute gravimeter, such as the small amplitude of the incipient faults, the inadequate representation of features for the faults, and hard-to-find in the noise, a novel method for incipient fault diagnosis of the cam-driven absolute gravimeter is put forward in this paper, which integrates the parameter-optimized Variational Mode Decomposition (VMD) with Light Gradient Boosting Machine (LightGBM). The sparrow search algorithm is used to optimize the VMD parameters. The parameter-optimized VMD algorithm is used to adaptively decompose the vibration signals of the gravimeter under different cases, and then an effective intrinsic mode function (IMF) is selected based on the Pearson correlation coefficient. Some high-frequency IMFs are subjected to adaptive noise reduction combined with low-frequency IMF reconstruction, and then the multi-scale permutation entropy with sensitive characteristics under different time scales is extracted as the fault feature vectors. The extracted multi-dimensional vector matrix is entered into the LightGBM classifier to realize the accurate diagnosis of the incipient faults for the cam-driven absolute gravimeter. The test results show that this method can effectively detect various incipient failures of the cam-driven absolute gravimeter, with an identification accuracy of 98.41%. With this method, the problem of low measurement accuracy for the cam-driven absolute gravimeter caused by the incipient faults is solved, and the rapid tracing and accurate positioning of these faults for the gravimeter are realized, promising a good prospect for engineering application.
Electron Affinities of Atoms and Structures of Atomic Negative Ions
Authors: Ning Chuangang , Lu Yuzhu
Published: May 2022

This Review presents electron affinities of atoms and structures of atomic negative ions. The negative ion properties of many elements in the main groups of the Periodic Table were well known in the late 20th century. However, our knowledge of the atomic negative ions of transitional elements, lanthanides, and actinides was completely lacking or largely rather qualitative at that time. Substantial progress both on experimental and theoretical sides in this subject has happened during the last two decades. New developments in the experimental methods that yield accurate electron affinities are described in this Review. Based on the previous reviews, a survey of the electron affinity toward the completion of the Periodic Table is presented. A set of atomic electron affinities and energy levels of atomic anions is recommended.
Enhanced optoelectronic performance and photogating effect in quasi-one-dimensional BiSeI wires
Authors: Hu H. J. , Zhen W. L. , Weng S. R. , Li Y. D. , Niu R. , Yue Z. L. , Xu F. , Pi L. , Zhang C. J. , Zhu W. K.
Published: May 2022

Quasi-one-dimensional (quasi-1D) materials are a newly arising topic in low-dimensional research. As a result of reduced dimensionality and enhanced anisotropy, the quasi-1D structure gives rise to novel properties and promising applications such as photodetectors. However, it remains an open question whether performance crossover will occur when the channel material is downsized. Here, we report on the fabrication and testing of photodetectors based on exfoliated quasi-1D BiSeI thin wires. Compared with the device on bulk crystal, a significantly enhanced photoresponse is observed, which is manifested by a series of performance parameters, including ultrahigh responsivity (7 × 104 A W−1), specific detectivity (2.5 × 1014 Jones), and external quantum efficiency (1.8 × 107%) when Vds = 3 V, λ = 515 nm, and P = 0.01 mW cm−2. The conventional photoconductive effect is unlikely to account for such a superior photoresponse, which is ultimately understood in terms of the increased specific surface area and the photogating effect caused by trapping states. This work provides a perspective for the modulation of optoelectronic properties and performance in quasi-1D materials.
Metaplectic geometrical optics for ray-based modeling of caustics: Theory and algorithms
Authors: Lopez N. A. , Dodin I. Y.
Published: May 2022

The optimization of radio frequency-wave (RF) systems for fusion experiments is often performed using ray-tracing codes, which rely on the geometrical-optics (GO) approximation. However, GO fails at caustics such as cutoffs and focal points, erroneously predicting the wave intensity to be infinite. This is a critical shortcoming of GO, since the caustic wave intensity is often the quantity of interest, e.g., RF heating. Full-wave modeling can be used instead, but the computational cost limits the speed at which such optimizations can be performed. We have developed a less expensive alternative called metaplectic geometrical optics (MGO). Instead of evolving waves in the usual x (coordinate) or k (spectral) representation, MGO uses a mixed X≡Ax+Bk representation. By continuously adjusting the matrix coefficients A and B along the rays, one can ensure that GO remains valid in the X coordinates without caustic singularities. The caustic-free result is then mapped back onto the original x space using metaplectic transforms. Here, we overview the MGO theory and review algorithms that will aid the development of an MGO-based ray-tracing code. We show how using orthosymplectic transformations leads to considerable simplifications compared to previously published MGO formulas. We also prove explicitly that MGO exactly reproduces standard GO when evaluated far from caustics (an important property that until now has only been inferred from numerical simulations), and we relate MGO to other semiclassical caustic-removal schemes published in the literature. This discussion is then augmented by an explicit comparison of the computed spectrum for a wave bounded between two cutoffs.
Direct current magnetic Hall probe technique for measurement of field penetration in thin film superconductors for superconducting radio frequency resonators
Authors: Senevirathne I. H. , Gurevich A. , Delayen J. R.
Published: May 2022

Superconducting Radio Frequency (SRF) cavities used in particle accelerators are typically formed from or coated with superconducting materials. Currently, high purity niobium is the material of choice for SRF cavities that have been optimized to operate near their theoretical field limits. This brings about the need for significant R & D efforts to develop next generation superconducting materials that could outperform Nb and keep up with the demands of new accelerator facilities. To achieve high quality factors and accelerating gradients, the cavity material should be able to remain in the superconducting Meissner state under a high RF magnetic field without penetration of quantized magnetic vortices through the cavity wall. Therefore, the magnetic field at which vortices penetrate a superconductor is one of the key parameters of merit of SRF cavities. Techniques to measure the onset of magnetic field penetration on thin film samples need to be developed to mitigate the issues with the conventional magnetometry measurements that are strongly influenced by the film orientation and shape and edge effects. In this work, we report the development of an experimental setup to measure the field of full flux penetration through films and multi-layered superconductors. Our system combines a small superconducting solenoid that can generate a magnetic field of up to 500 mT at the sample surface and three Hall probes to detect the full flux penetration through the superconductor. This setup can be used to study alternative materials that could potentially outperform niobium, as well as superconductor–insulator–superconductor (SIS) multilayer coatings on niobium.
Electronic and magnetic properties of vanadium dichalcogenides: A brief overview on theory and experiment
Authors: Abdul Wasey A. H. M. , Das G. P.
Published: May 2022

Two-dimensional layered materials, in general, and transition metal dichalcogenides, in particular, are promising as future device materials. Vanadium based dichalcogenides, i.e., VX2 (X = S, Se, and Te) are special in the class for showing a wide range of intriguing properties. Depending on the structural phases, VX2 can be metallic or semiconducting. The T-phase, i.e., the metallic one, is well known to host some exotic electronic properties like the charge density wave, anomalous Hall effect, ferromagnetism, etc., having strong bearing as an electronic device material. The H-phase, on the other hand, is also predicted to show ferromagnetism. The materials show properties strongly dependent on their physical dimensionality, a clear manifestation of quantum confinement effects. Several experimental attempts successfully demonstrated chemical and bio-medical applications also of this class of materials. Moreover, the heterostructures formed by VX2 with other electronically dissimilar materials could bring more variation in their existing properties. Therefore, the study of VX2 materials provides a fertile ground to explore several fascinating physical phenomena and their possibilities in future applications. Here, in the present paper, we have tried to review the current scenario in this particular field by highlighting some recent key findings. The paper is aimed at providing some insight into the recent theoretical and experimental achievements in this direction, especially in the context of electronic and magnetic properties in their lower physical dimensionality. This could furnish a comprehensive guiding tour toward exploration in the journey through VX2 materials.
Bayesian, frequentist, and information geometric approaches to parametric uncertainty quantification of classical empirical interatomic potentials
Authors: Kurniawan Yonatan , Petrie Cody L. , Williams Kinamo J. , Transtrum Mark K. , Tadmor Ellad B. , Elliott Ryan S. , Karls Daniel S. , Wen Mingjian
Published: May 2022

In this paper, we consider the problem of quantifying parametric uncertainty in classical empirical interatomic potentials (IPs) using both Bayesian (Markov Chain Monte Carlo) and frequentist (profile likelihood) methods. We interface these tools with the Open Knowledgebase of Interatomic Models and study three models based on the Lennard-Jones, Morse, and Stillinger–Weber potentials. We confirm that IPs are typically sloppy, i.e., insensitive to coordinated changes in some parameter combinations. Because the inverse problem in such models is ill-conditioned, parameters are unidentifiable. This presents challenges for traditional statistical methods, as we demonstrate and interpret within both Bayesian and frequentist frameworks. We use information geometry to illuminate the underlying cause of this phenomenon and show that IPs have global properties similar to those of sloppy models from fields, such as systems biology, power systems, and critical phenomena. IPs correspond to bounded manifolds with a hierarchy of widths, leading to low effective dimensionality in the model. We show how information geometry can motivate new, natural parameterizations that improve the stability and interpretation of uncertainty quantification analysis and further suggest simplified, less-sloppy models.
Identification and assessment method of cable joint health status based on traveling wave reflection
Authors: Zhou Feng , Zhu Fan , Lyu Qiang , Bai Xingzhen , Cui Baochun , Wang Pengfei
Published: May 2022

Due to the difficulty in accurately detecting the health status of cable joints, a new method of identifying and assessing the cable joints’ health status based on traveling wave reflection is proposed. By transmitting nanosecond pulse signals at the head end of the cable, the health status characteristics of the cable joints can be obtained, and the noise reduction of the measurement signals is performed by the wavelet function to identify the reflected wave at the joint and the end of the cable. The equivalent circuits and simulation models of contact resistance and leakage resistance are established, and the contact resistance and leakage resistance of the cable joints are calculated according to the amplitude and phase of the reflected signals at the joint and the end of the cable. By comparing with the resistance when the joint is in healthy operation, any measured parameter exceeding the corresponding standard is considered a joint fault. Simulations and test results show that the method can accurately identify the reflected signals of the cable joints in different operating states, and with changes in joint health, clear regular features can be extracted from the reflected signals, and the quality and health of the joints can be determined. The traveling wave method can be used to detect cable joint faults and provide an early warning of defects, which provides a new idea for online monitoring and early warning of cable joints in both theory and engineering practice.
Ultrafast vibrational dynamics of the free OD at the air/water interface: Negligible isotopic dilution effect but large isotope substitution effect
Authors: Ahmed Mohammed , Nihonyanagi Satoshi , Tahara Tahei
Published: May 2022

Vibrational relaxation dynamics of the OH stretch of water at the air/water interface has been a subject of intensive research, facilitated by recent developments in ultrafast interface-selective nonlinear spectroscopy. However, a reliable determination of the vibrational relaxation dynamics in the OD stretch region at the air/D2O interface has not been yet achieved. Here, we report a study of the vibrational relaxation of the free OD carried out by time-resolved heterodyne-detected vibrational sum frequency generation spectroscopy. The results obtained with the aid of singular value decomposition analysis indicate that the vibrational relaxation (T1) time of the free OD at the air/D2O interface and air/isotopically diluted water (HOD-H2O) interfaces show no detectable isotopic dilution effect within the experimental error, as in the case of the free OH in the OH stretch region. Thus, it is concluded that the relaxation of the excited free OH/OD predominantly proceeds with their reorientation, negating a major contribution of the intramolecular energy transfer. It is also shown that the T1 time of the free OD is substantially longer than that of the free OH, further supporting the reorientation relaxation mechanism. The large difference in the T1 time between the free OD and the free OH (factor of ∼2) may indicate the nuclear quantum effect on the diffusive reorientation of the free OD/OH because this difference is significantly larger than the value expected for a classical rotational motion.
Slow dynamics and time–composition superposition in gels of cellulose nanocrystals
Authors: Morlet-Decarnin Lise , Divoux Thibaut , Manneville Sébastien
Published: May 2022

Cellulose nanocrystals (CNCs) are rodlike biosourced colloidal particles used as key building blocks in a growing number of materials with innovative mechanical or optical properties. While CNCs form stable suspensions at low volume fractions in pure water, they aggregate in the presence of salt and form colloidal gels with time-dependent properties. Here, we study the impact of salt concentration on the slow aging dynamics of CNC gels following the cessation of a high-shear flow that fully fluidizes the sample. We show that the higher the salt content, the faster the recovery of elasticity upon flow cessation. Most remarkably, the elastic modulus G′ obeys a time–composition superposition principle: the temporal evolution of G′ can be rescaled onto a universal sigmoidal master curve spanning 13 orders of magnitude in time for a wide range of salt concentrations. Such a rescaling is obtained through a time-shift factor that follows a steep power-law decay with increasing salt concentration until it saturates at large salt content. These findings are robust to changes in the type of salt and the CNC content. We further show that both linear and nonlinear rheological properties of CNC gels of various compositions, including, e.g., the frequency-dependence of viscoelastic spectra and the yield strain, can be rescaled based on the sample age along the general master curve. Our results provide strong evidence for universality in the aging dynamics of CNC gels and call for microstructural investigations during recovery as well as theoretical modeling of time–composition superposition in rodlike colloids.
Tiered synchronization in coupled oscillator populations with interaction delays and higher-order interactions
Authors: Skardal Per Sebastian , Xu Can
Published: May 2022

We study synchronization in large populations of coupled phase oscillators with time delays and higher-order interactions. With each of these effects individually giving rise to bistability between incoherence and synchronization via subcriticality at the onset of synchronization and the development of a saddle node, we find that their combination yields another mechanism behind bistability, where supercriticality at onset may be maintained; instead, the formation of two saddle nodes creates tiered synchronization, i.e., bistability between a weakly synchronized state and a strongly synchronized state. We demonstrate these findings by first deriving the low dimensional dynamics of the system and examining the system bifurcations using a stability and steady-state analysis.
Supervised learning for accurate mesoscale simulations of suspension flow in wall-bounded geometries
Authors: Barcelos Erika I. , Khani Shaghayegh , Naccache Mônica F. , Maia Joao
Published: May 2022

Herein, we have employed a supervised learning approach combined with Core-Modified Dissipative Particle Dynamics Simulations (CM-DPD) in order to develop and design a reliable physics-based computational model that will be used in studying confined flow of suspensions. CM-DPD was recently developed and has shown promising performance in capturing rheological behavior of colloidal suspensions; however, the model becomes problematic when the flow of the material is confined between two walls. Wall-penetration by the particles is an unphysical phenomenon that occurs in coarse-grained simulations such as Dissipative Particle Dynamics (DPD) that mostly rely on soft inter-particle interactions. Different solutions to this problem have been proposed in the literature; however, no reports have been given on how to deal with walls using CM-DPD. Due to complexity of interactions and system parameters, designing a realistic simulation model is not a trivial task. Therefore, in this work we have trained a Random Forest (RF) for predicting wall penetration as we vary input parameters such as interaction potentials, flow rate, volume fraction of colloidal particles, and confinement ratio. The RF predictions were compared against simulation tests, and a sufficiently high accuracy and low errors were obtained. This study shows the viability and potentiality of ML combined with DPD to perform parametric studies in complex fluids.
Physics-based statistical learning perspectives on droplet formation characteristics in microfluidic cross-junctions
Authors: Wang Ji-Xiang , Yu Wei , Wu Zhe , Liu Xiangdong , Chen Yongping
Published: May 2022

Size-controllable micro-droplets obtained in microfluidic cross-junctions are significant in microfluidics. Modeling and predictions in microfluidic-based droplet formation characteristics to date using various traditional theoretical or empirical correlations are far from satisfactory. Driven by unprecedented data volumes from microfluidic experiments and simulations, statistical learning can offer a powerful technique to extract data that can be interpreted into underlying fluid physics and modeling. This Letter historically combines the current experimental data and experimental/numerical data from previous publications as a microfluidics-based droplet formation characteristics database. Two supervised statistical learning algorithms, deep neural network and factorization-machine-based neural network (Deep-FM), were established to model and predict the formed droplet size in microfluidic cross-junctions. As a newly developed statistical learning code in 2017, the Deep-FM manifests a better prediction performance, where the average relative error was only 4.09% and nearly 98% of the data points had individual relative errors of 10% or less. Such high accuracy can be attributed to the outstanding interactions between high-order and low-order features of the Deep-FM framework. Another innovation in this Letter lies in the training dataset shrinkage and optimization without sacrificing the prediction accuracy. Such a method pioneers statistical learning algorithms in small-sample modeling problems, which is different from big data modeling and analyses. The improved statistical learning proposed in this Letter provides universal high-accuracy modeling for microfluidic-based droplet characteristics prediction, which can be an influential data-processing framework that can boost and probably transform current lines of microfluidic physics research and industrial applications.
Perspective on atomic scale investigation of point and extended defects in gallium oxide
Authors: Huang Hsien-Lien , Chae Christopher , Hwang Jinwoo
Published: May 2022

Beta-gallium oxide (β-Ga2O3) has recently attracted significant attention as an outstanding candidate for ultra-wide bandgap applications due to its unique advantages. Point and extended defects in β-Ga2O3 can significantly reduce the net doping and play an essential role with their functionality in advancing β-Ga2O3 device performance. It is, therefore, critical to gain an atomic level understanding of the structure of the defects and how they correlate to important properties of defects in β-Ga2O3. In this Perspective, we provide an overview of the recent characterization works involving scanning transmission electron microscopy and related techniques revealing the detailed structure of various point and extended defects in β-Ga2O3 and β-(AlxGa1−x)2O3 heterostructures. This article aims to offer insight into how defects determine important aspects of the material, such as in crystal growth, dopant incorporation and activation, and phase stability. The new information that we summarize here is expected to help achieve atomic scale control of defects in β-Ga2O3 materials and devices for development of the next generation power electronics applications.
Efficient implementation of molecular CCSD gradients with Cholesky-decomposed electron repulsion integrals
Authors: Schnack-Petersen Anna Kristina , Koch Henrik , Coriani Sonia , Kjønstad Eirik F.
Published: May 2022

We present an efficient implementation of ground and excited state coupled cluster singles and doubles (CCSD) gradients based on Cholesky-decomposed electron repulsion integrals. Cholesky decomposition and density fitting are both inner projection methods, and, thus, similar implementation schemes can be applied for both methods. One well-known advantage of inner projection methods, which we exploit in our implementation, is that one can avoid storing large V3O and V4 arrays by instead considering three-index intermediates. Furthermore, our implementation does not require the formation and storage of Cholesky vector derivatives. The new implementation is shown to perform well, with less than 10% of the time spent calculating the gradients in geometry optimizations. Furthermore, the computational time per optimization cycle is significantly lower compared to other implementations based on an inner projection method. We showcase the capabilities of the implementation by optimizing the geometry of the retinal molecule (C20H28O) at the CCSD/aug-cc-pVDZ level of theory.
Direct bandgap GeSn nanowires enabled with ultrahigh tension from harnessing intrinsic compressive strain
Authors: Burt Daniel , Joo Hyo-Jun , Kim Youngmin , Jung Yongduck , Chen Melvina , Luo Manlin , Kang Dong-Ho , Assali Simone , Zhang Lin , Son Bongkwon , Fan Weijun , Moutanabbir Oussama , Ikonic Zoran , Tan Chuan Seng , Huang Yi-Chiau , Nam Donguk
Published: May 2022

GeSn alloys are a promising emerging complementary metal–oxide–semiconductor compatible technology for applications in photonics and electronics. However, the unavoidable intrinsic compressive strain introduced during epitaxial growth has prevented researchers from pushing the performance of GeSn devices to the limit and realizing real-world applications. In this paper, we present a straightforward geometric strain-inversion technique that harnesses the harmful compressive strain to achieve beneficial tensile strain in GeSn nanowires, drastically increasing the directness of the band structure. We achieve ∼2.67% uniaxial tensile strain in ∼120 nm wide nanowires, surpassing other values reported thus far. Unique pseudo-superlattices comprising of indirect and direct bandgap GeSn are demonstrated in a single material only by applying a periodic tensile strain. Improved directness in tensile-strained GeSn significantly enhances the photoluminescence by a factor of ∼2.5. This work represents a way to develop scalable band-engineered GeSn nanowire devices with lithographic design flexibility. This technique can be potentially applied to any layer with an intrinsic compressive strain, creating opportunities for unique tensile strained materials with diverse electronic and photonic applications.
Controlling cluster size in 2D phase-separating binary mixtures with specific interactions
Authors: Palaia Ivan , Šarić Anđela
Published: May 2022

By varying the concentration of molecules in the cytoplasm or on the membrane, cells can induce the formation of condensates and liquid droplets, similar to phase separation. Their thermodynamics, much studied, depends on the mutual interactions between microscopic constituents. Here, we focus on the kinetics and size control of 2D clusters, forming on membranes. Using molecular dynamics of patchy colloids, we model a system of two species of proteins, giving origin to specific heterotypic bonds. We find that concentrations, together with valence and bond strength, control both the size and the growth time rate of the clusters. In particular, if one species is in large excess, it gradually saturates the binding sites of the other species; the system then becomes kinetically arrested and cluster coarsening slows down or stops, thus yielding effective size selection. This phenomenology is observed both in solid and fluid clusters, which feature additional generic homotypic interactions and are reminiscent of the ones observed on biological membranes.
High temperature phase transitions in NaNbO3 epitaxial films grown under tensile lattice strain
Authors: Bin Anooz S. , Wang Y. , Petrik P. , de Oliveira Guimaraes M. , Schmidbauer M. , Schwarzkopf J.
Published: May 2022

We have investigated high temperature phase transitions in NaNbO3 thin films epitaxially grown under tensile lattice strain on (110) DyScO3 substrates using metal-organic vapor phase epitaxy. At room temperature, a very regular stripe domain pattern consisting of the monoclinic a1a2 ferroelectric phase was observed. Temperature-dependent studies of the refractive index and the optical bandgap as well as in situ high-resolution x-ray diffraction measurements prove a ferroelectric–ferroelectric phase transition in the range between 250 and 300 °C. The experimental results strongly suggest that the high-temperature phase exhibits a distorted orthorhombic a1/a2 crystal symmetry, with the electric polarization vector lying exclusively in the plane. A second phase transition was observed at about 500 °C, which presumably signifies the transition to the paraelectric phase. Both phase transitions show a pronounced temperature-dependent hysteresis, indicating first-order phase transitions.
Effective single component description of steady state structures of passive particles in an active bath
Authors: Singh Jay Prakash , Pattanayak Sudipta , Mishra Shradha , Chakrabarti Jaydeb
Published: May 2022

We model a binary mixture of passive and active Brownian particles in two dimensions using the effective interaction between passive particles in the active bath. The activity of active particles and the size ratio of two types of particles are the two control parameters in the system. The effective interaction is calculated from the average force on two particles generated by the active particles. The effective interaction can be attractive or repulsive, depending on the system parameters. The passive particles form four distinct structural orders for different system parameters, viz., homogeneous structures, disordered cluster, ordered cluster, and crystalline structure. The change in structure is dictated by the change in nature of the effective interaction. We further confirm the four structures using a full microscopic simulation of active and passive mixture. Our study is useful to understand the different collective behavior in non-equilibrium systems.