bluuebunny/crossref_metadata_2025 huggingface dataset:
Prähospitaler Kreislaufstillstand unter einem seltenen Umstand
Authors: Grübl Tobias , Günnewig Sebastian , Schulte Holger , Weller Norbert , Schmidbauer Willi , Jänig Christoph Walter , Müller Gunnar
Published: September 2022

Es wird der Fall eines jungen Patienten mit Kreislaufstillstand nach suizidaler Inkorporation von Natriumnitrat beschrieben.

Während der Reanimation sind reversible Ursachen zu suchen und schnell zu therapieren. Intoxikationen sind dabei oft nur schwer detektierbar. Nitroverbindungen führen zur Bildung von
Methämoglobin und so zur Hypoxie. Anhand mobiler Laborgeräte kann dies bereits prähospital diagnostiziert werden. Therapeutisch ist zunächst ein symptomatisches Vorgehen mit Oxygenierung
und Kreislaufunterstützung sowie ggf. erweiterten Maßnahmen angezeigt. Auch für seltene Intoxikationen sollten spezifische Antidota zumindest zentral vorgehalten werden. Notfallmediziner
müssen die Zugriffs- und alternative Behandlungsmöglichkeiten bis zu deren Verfügbarkeit kennen. Im Falle eines Kreislaufstillstands können Systeme zur extrakorporalen
Kreislaufunterstützung diesen Zeitraum überbrücken.
Neurodegeneration: Microglia: Nf-Kappab Signaling
Pathways
Authors: Singh Aditya , Ansari Vaseem Ahamad , Mahmood Tarique , Ahsan Farogh , Wasim Rufaida
Published: September 2022

Microglia is cells of mesodermal/mesenchymal origin that migrate into the
central nervous system (CNS) to form resident macrophages inside the special
brain microenvironment. Intact with both neuronal and non-neuronal cells,
microglia is highly active cells. Continuous process extension and retraction
allows microglia to scan the brain parenchyma for threats. They are also able to
change their morphology from ramified to amoeboid, which is a sign of cell
activity. In response to pleiotropic stimuli such as neurotransmitters,
cytokines, and plasma proteins, microglia express a diverse range of receptors.
As controllers of synaptic activities and phagocytosis of developing neurons,
they serve a critical role in the healthy brain and have significant effects on
synaptic plasticity and adult neurogenesis. A frequent cause of
hypoparathyroidism is a mutation in the gene glial cells missing-2 (GCM2).
Neonatal hypoparathyroidism has an amorphic recessive GCM2 mutation, while
autosomal dominant hypoparathyroidism has a dominant-negative GCM2 mutation.
Curiously, familial isolated hyperparathyroidism has been associated with
activating GCM2 mutation. In addition to seizures, neurocognitive impairment,
carpopedal spasm, tingling and numbness are common clinical manifestations of
hypoparathyroidism. Biogenic amines are a group of four neurotransmitters that
belong to that category and these include serotonin, dopamine, norepinephrine,
and epinephrine. Numerous antidepressants prevent the reuptake from occurring
the brain-gut axis is hardwired through the CNS, enteric nervous system (ENS),
neuroendocrine linkages and highly innervated nerve plexuses.
Comparative Inhibitory Effects of Natural Biflavones from Ginkgo against Human CYP1B1 in Recombinant Enzymes and MCF-7 Cells
Authors: Chen Xiaodong , Zhao Tingting , Du Jie , Guan Xintong , Yu Hong , Wang Dalong , Wang Changyuan , Meng Qiang , Yao Jialin , Sun Huijun , Liu Kexin , Wu Jingjing
Published: September 2022

Human cytochrome P450 1B1 (CYP1B1) is an extrahepatic enzyme overexpressed in many tumors and associated with angiogenesis. Ginkgetin, isoginkgetin, sciadopitysin, and amentoflavone, the
primary biflavones found in Ginkgo biloba, have excellent anti-inflammatory and anti-tumor effects. However, the effect of biflavones on CYP1B1 activities remains unknown. In this
study, 7-ethoxyresorufin O-deethylation (EROD) was used to characterize the activities of CYP1 families. The impacts of four ginkgo biflavones on CYP1B1 activity and the cellular
protein expression of CYP1B1 were systematically investigated. The results showed that amentoflavone with six hydroxyl substituents exhibited the most potent selective inhibitory effect on
CYP1B1 activity with IC50 of 0.054 µM in four biflavones. Sciadopitysin, with three hydroxyl and three methoxy substituents, had the weakest inhibitory activity against CYP1B1.
Ginkgetin and isoginkgetin, both with four hydroxyl and two methoxy substituents, showed similar inhibitory intensity towards CYP1B1 with IC50 values of 0.289 and 0.211 µM,
respectively. Kinetic analysis showed that ginkgetin and amentoflavone inhibited CYP1B1 in a non-competitive mode, whereas sciadopitysin and isoginkgetin induced competitive or mixed types
of inhibition. Notably, four ginkgo biflavones were also confirmed to suppress the protein expressions of CYP1B1 and AhR in MCF-7. Furthermore, molecular docking studies indicated
more hydrogen bonds formed between amentoflavone and CYP1B1, which might explain the strongest inhibitory action towards CYP1B1. In summary, these findings suggested that biflavones
remarkably inhibited both the activity and protein expression of CYP1B1 and the inhibitory activities enhanced with the increasing hydroxyl substitution, providing new insights into the
anti-tumor potentials of biflavones.
Assessment of Deviations of Implants Installed with Prototyped Surgical Guide and Conventional Guide: In Vitro Study
Authors: Rodrigues João Marcelo Meireles , Santos Pâmela Leticia , Mendonça Gustavo , Faloni Ana Paula de Souza , Finoti Livia Sertori , Margonar Rogério
Published: September 2022

Objective The study aimed to assess the angular and linear deviations of implants installed in mannequins aided by surgical guides produced with the techniques of dual tomography (DT), model-based tomography (MT), and nonprototyped guide.

Materials and Methods Implants were installed in mannequins of a partially edentulous maxilla and divided into three groups: Group C (n = 20), implants installed using the conventional technique with flap opening and conventional guide; Group DT (n = 20), implants installed using guided surgery with the dual tomography technique; and Group MT (n = 20), implants installed using the model-based tomography technique. After implant installation, the mannequin was subjected to a computed tomography (CT) to measure the linear and angular deviations of implant positioning relative to the initial planning on both sides.

Results There was a higher mean angular deviation in group C (4.61 ± 1.21, p ≤ 0.001) than in groups DT (2.13 ± 0.62) and MT (1.87 ± 0.94), which were statistically similar between each other. Similarly, the linear deviations showed group C with the greatest discrepancy in relation to the other groups in the crown (2.17 ± 0.82, p = 0.007), central (2.2 ± 0.77, p = 0.004), and apical (2.34 ± 0.8, p = 0.001) regions.

Conclusion The techniques of DT and MT presented smaller angular and linear deviations than the conventional technique with the nonprototyped guide. There was no difference between the two-guided surgery techniques.
New Technique Seeking Prophylaxis in the Displacement of Distal Ventriculoperitoneal Shunt Catheter – Case Report
Authors: Melo João Victor Oliveira de , Silva Rebeca Brasil da , Reis Franklin , Amorim Robson Luís Oliveira de
Published: September 2022

Idiopathic intracranial hypertension is a comorbidity treated in neurosurgical practice today with the ventriculoperitoneal derivation technique. However, despite its great safety and efficacy, this technique is susceptible to infrequent failures, such as displacement of the catheter leading to the need for reoperation. In the present article, we report a case involving a peritoneal catheter tip retropulsion for subcutaneous tissue in an obese patient with posterior correction using an extending connector to the distal catheter, without harming the drainage flow. In our case report, the patient went on without complications and without the occurrence of new displacement after 8 months of surgery. The results obtained by this technique supported the idea that this alternative construction minimizes the risk of displacement of the peritoneal tip catheter in obese patients and with high intra-abdominal pressure, helping to reduce the need for reoperations. In addition, the present case report supports the need for further studies and clinical trials on the subject.
Endoscopic Third Ventriculostomy in the Pediatric Population: Case Series Report
Authors: Pinto Hortência Angelina Silva , Ferreira Ana Luísa de Cássia Magalhães , Deus Isadora Barbosa de , Ferreira Darlan Rebolças Gama , Gonçalves Laryssa Vieira , Faleiro Rodrigo Moreira
Published: September 2022

Objective Hydrocephalus is characterized by multi- or uniloculated ventricular dilatation, and there are differences between the etiology and therapeutic response of each type. Endoscopic third ventriculostomy (ETV) is indicated for the treatment of obstructive hydrocephalus, with a reported efficacy between 50% and 76%. Reduced efficacy of the procedure has been demonstrated in communicating hydrocephalus due to multifactorial pathogenesis, and, in patients with myelomeningocele, its efficacy ranges from 15% to 20% at birth. The present study aims to compare the efficacy of ETV in the treatment of congenital obstructive hydrocephalus (COH) and acquired obstructive hydrocephalus (AOH) in the pediatric population.

Methods A retrospective study of 169 endoscopic surgeries performed by the senior author in two institutions, one public (Hospital João XXIII, Belo Horizonte, Minas Gerais) and another private (Hospital Felício Rocho, Belo Horizonte, Minas Gerais), in the period from 2003 a 2020. From the selection of 169 patients, only 77 cases fit the age profile ≤12 years of the present study. Of these, 46 were male, and the age range ranged from 10 days to 12 years. The study included multiple etiologies, which were divided into 2 groups, 34 related to COH, and 43 to AOH.

Results Regarding the cases of COH, 22 were submitted to ETV as the main treatment, with 14 (63.63%) effective and 8 (36.36%) ineffective procedures. As for the cases of AOH, 13 patients underwent ETV, and 8 (61.53%) procedures were effective, and 5 (38.46%), ineffective.

Conclusions Through the calculation of the p-value of 0.49, we concluded that it cannot stated that the efficacy of ETV is greater in COH than in AOH.
Characterization, Physical Properties, and Biocompatibility of Novel Tricalcium Silicate–Chitosan Endodontic Sealer
Authors: Maharti Ike D. , Suprastiwi Endang , Agusnar Harry , Herdianto Nendar , Margono Anggraini
Published: September 2022

Objective The purpose of this study was to compare the characteristics, physical properties, and biocompatibility of the novel tricalcium silicate–chitosan (TCS-C) sealer with AH Plus and Sure-Seal Root.

Materials and Methods The TCS-C powder was prepared by mixing tricalcium silicate with 2% water-soluble chitosan at a 5:1 ratio, followed by sufficient addition of 10 g/mL ratio of double-distilled water to form a homogeneous cement. Material characterizations (the Fourier Transform InfraRed [FTIR] and X-ray diffraction [XRD]), physical property investigations (flow and film thickness), and cytotoxicity tests in 3T3 mouse embryo fibroblast cell (MTT assay method) were performed on sealers, and the results were compared with those of the commercial products.

Statistical Analysis Statistical analysis was performed on flow and film thickness. The normality of the data was tested using the Shapiro–Wilk test. Statistical analysis was performed with one-way analysis of variance (ANOVA). The level of significance was set at p < 0.05.

Results The TCS-C showed a mean flow of 31.98 ± 0.68 mm, compared with Sure Seal Root at 26.38 ± 0.69 mm and AH Plus at 26.50 ± 0.12 mm. The TCS-C showed a mean film thickness of 60 ± 10.0 mm compared with Sure-Seal Root at 50 ± 10.0 mm and AH Plus at 40 ± 15.8 mm. The TCS-C exhibited low to no cytotoxicity in fibroblast cell at all concentrations and exposure times.

Conclusion Adding water-soluble chitosan may improve the physical and biologic properties of tricalcium silicate cement. The novel TCS-C sealer did not fully meet the physical properties of an endodontic sealer, but it was not cytotoxic to fibroblast cells.
Atypical Presentation of Marginal Zone Lymphoma as Isolated Diffuse Bone Marrow Involvement: Utility of F-18 FDG PET/CT in Diagnosis and Response Assessment
Authors: Gauthaman Dinesh Kumar , Subramanyam Padma , Palaniswamy Shanmuga Sundaram
Published: September 2022

Non-Hodgkin's lymphoma (NHL) with secondary bone marrow involvement is relatively common. However, isolated involvement of bone marrow in marginal zone type of NHL is atypical and rare. Here, we describe a patient of atypical marginal zone lymphoma with isolated bone marrow involvement who presented with weight loss and bicytopenia, where F-18 FDG PET/CT (fluorine-18-labeled fluorodeoxyglucose positron emission tomography with computed tomography) imaging played a pivotal role in establishing the diagnosis when conventional imaging modalities were unremarkable. The patient was successfully treated with systemic chemotherapy (rituximab, cyclophosphamide, prednisolone) and achieved complete remission, as demonstrated by a follow-up F-18 FDG PET/CT scan.
Preradioactive Iodine Thyroglobulin Levels as Predictors of Metastasis in Well-Differentiated Thyroid Carcinoma Patients
Authors: Darmawan Budi , Sari Meutia , Susilo Stefani , Kartamihardja Achmad Hussein S.
Published: September 2022

Objective The aim of this study was to determine the cut-off value of thyroglobulin (Tg) levels as a predictor of metastases in post total thyroidectomy patients with well-differentiated thyroid carcinoma (DTC).

Materials and Methods A retrospective case-control study with an observational diagnostic approach was done. Subjects were 102 DTC patients divided into a case group with metastases and a control group without metastases. Tg and antithyroglobulin antibody (ATA) levels on thyroid-stimulating hormone (TSH)-stimulated preradioactive iodine were compared with each other. Diagnosis of metastases was based on postradioactive iodine whole-body scan. The cut-off value for Tg preradioactive iodine and the area under the curve (AUC) were obtained from the receiver operating characteristic curve.

Result The characteristics and histopathological type of DTC among these two groups were not significantly different (p = 0.47). The Tg levels in the case and control groups were 106 (2.2–6,000) ng/mL and 2.7 (0.3–10.10) ng/mL, respectively (p = 0.0001). TSH level in the case group was 50 (30–107) µIU/mL and in the control was 50 (20–100) µIU/mL (p = 0.224). ATA levels in the case and control groups were 0–3,000 and 0–629 ng/mL, respectively (p = 0.01). The AUC was 0.976 with a 95% confidence interval of 0.924 to 0.996 and a standard error of 0.016. The cut-off value of preradioactive iodine Tg was 10.1 ng/mL or higher with sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 96.1, 100, 98.0, 100, and 96.2%, respectively.

Conclusion Preradioactive iodine Tg level 10.1 ng/mL or higher can be used as a predictor of metastasis in patients with DTC.
A Prospective Study to Assess Patients' Understanding and Retention of Postoperative Instructions following a Fixed Partial Denture, Using Different Information Delivery Techniques
Authors: Adawi Hafiz , Jain Saurabh , Hakami Aeshah H. , Mtwam Naseem A. , Koriri Almaha Y. A. , Adawi Abdulaziz A. A.
Published: September 2022

Objective This study was aimed to evaluate the effect of using different modes of at-home maintenance information delivery on patients' understanding and the level of information retention.

Materials and Methods Sixty patients were asked to answer a questionnaire while undergoing mouth preparations for receiving a fixed partial denture. The questionnaire includes questions related to at-home maintenance procedures and recall visits. After finishing the first questionnaire, these patients were randomly assigned into three groups, and each group was given education about at-home maintenance procedures and recall visits by different means. Group 1 participants were educated by giving live demonstrations. Group 2 participants were shown a prerecorded video, whereas group 3 participants were given written instructions. All Participants were recalled after 1 week of the last visit and were asked to fill out the same questionnaire.

Statistical Ananlysis Collected data were tabulated in a Microsoft Excel Spreadsheet and were analyzed using the Chi-square test, one-way ANOVA, paired t-test, and post hoc Bonferroni test. A p-Value < 0.05 was regarded as statistically significant for all the analyses.

Results Group 1 showed greatest information retention as compared with groups 2 and 3 (p = 0.045). There was significant difference in the knowledge of group 1 as compared with groups 2 (p = 0.020) and 3 (p = 0.048).

Conclusion The mode of delivering postoperative instructions after fixed partial denture treatment does have an effect on the patient understanding level and information retention. Patients who were given live demonstrations showed the best results compared with video recordings and written leaflets.
Active MMP-8 as a Biomarker of Peri-implant Health or Disease
Authors: Xanthopoulou Vithleem , Räisänen Ismo , Sorsa Timo , Sakellari Dimitra
Published: September 2022

Objectives This study investigated the potential of testing for active matrix metalloproteinase-8 (aMMP-8) by a quantitative point-of-care (PoC), chairside, lateral flow immunotest as a biomarker for the presence or absence of peri-implant diseases.

Materials and Methods Eighty healthy patients with implants were recruited. The samples were collected from peri-implant sulcular fluid and quantitatively analyzed for aMMP-8. Clinical indices, which included probing depth, clinical attachment loss, bleeding on probing, and plaque, were recorded and radiographic assessments were performed.

Statistical Analysis Comparisons of aMMP-8 levels and clinical parameters were analyzed by the Kruskal–Wallis test and the pairwise post hoc Dunn–Bonferroni test. A receiver operating curve analysis was used to analyze the diagnostic ability of aMMP-8 and the correlation between aMMP-8 and probing depth of the sampled site was sought by Spearman's rho and the coefficient of determination (R
2).

Results Statistical analysis revealed statistically significant differences of aMMP-8 levels between the healthy and the mucositis and peri-implantitis groups, and between the mucositis and the peri-implantitis groups. Increasing probing depths of the sampled site and aMMP-8 levels were significantly correlated.

Conclusions These data suggest that the aMMP-8 PoC test can be a beneficial adjunctive tool for early identification and screening of the risk of peri-implant diseases and progression.
Measuring Quality of Life after Venous Thromboembolism: Who, When, and How?
Authors: Tavoly Mazdak , Asady Elia , Wik Hilde Skuterud , Ghanima Waleed
Published: September 2022

There is a growing body of evidence revealing that many patients with a history of venous thromboembolism (VTE) suffer from long-lasting sequelae such as post-thrombotic syndrome and post-pulmonary embolism syndrome. These two syndromes are detrimental to patients as they affect their quality of life (QOL). From this perspective, monitoring QOL may play a crucial role to improve quality care in VTE patients. Many studies have explored possible temporal relations between VTE episodes and decreased functional status and/or QOL. However, studies exploring the implementation of QOL and functional status questionnaires in clinical practice are scarce. In this context, we discuss possible perspectives synthetized from available literature regarding in whom, when, and how QOL could be measured in clinical practice.
Hahnemann's Sick Proving: A Comprehensive Study on Its Working Methodology
Authors: Tiwary Himanshu Sekhar , Tiwary Nidhi
Published: September 2022

Background Homoeopathy operates with highly potentised medicines since, during sickness, there is a state of heightened sensitivity to similar stimuli in an individual. The same proposition is also the guiding principle behind one of the advanced methods of Hahnemann, i.e. sick proving. This tool was employed by Hahnemann in his later life to record the symptoms from sensitive and chronic patients. Unfortunately, this collateral method of drug proving has not been examined thoroughly and hence has not been utilised. This study intends to revisit Hahnemann's sick proving and decipher the finer shades of its working methodology.

Material and Methods A comprehensive literature search and analysis for sick proving was done from Hahnemann's major works such as Organon of Medicine, the Chronic Diseases, Materia Medica Pura and other literature such as lesser writings, redacted writings, letters, biographies and miscellaneous publications. All the proving records of the Chronic Diseases were examined in terms of their source and methodology and analysed from the perspective of sick proving.

Results From the present study, it has distinctly emerged that Hahnemann had a very systemic and methodical process of sick proving observed mainly in unaltering chronic patients. He used to take healthy drug proving symptoms mainly from other sources for his work in the Chronic Diseases and add symptoms from his sick proving as a collateral route. Sick proving was part of follow-up consultation in new as well as extensively proved drugs as evident from the Letter of Hermann Hartlaub in 1834. He added many valuable polychrest drugs in our armamentarium with the help of this method in his book the Chronic Diseases.

Conclusion Unlike healthy drug proving, sick proving by Hahnemann has not been thoroughly investigated despite its sound logic and tangible merits. A more detailed study is required to realise the full potential of this wonderful method of drug proving.
Padrão incomum de impacto marginal osteocondral em fraturas acetabulares: Um relatório de dois casos
Authors: Ibrahim Bahaaeldin , Badran Mahmoud , Khalifa Ahmed A. , Abubeih Hossam , Farouk Osama
Published: September 2022

As fraturas acetabulares podem ser acompanhadas por lesões de impacto articular, afetando os desfechos se não vistas ou tratadas de modo incompleto. A impactação marginal detectada em estudos de imagem pré- ou intraoperatórios deve ser reduzida anatomicamente usando a cabeça femoral como modelo e aumentando o defeito com enxerto ósseo, se necessário. A superfície articular do segmento impactado parece voltada para a frente durante a cirurgia, que é a descrição clássica de tais lesões. No relatório atual, descrevemos um padrão incomum de aparecimento de lesões de impacto marginal em dois pacientes, onde a superfície articular do fragmento impactado está voltado para a cavidade articular, sendo o inverso da descrição clássica, aludindo ao mecanismo provável de sua ocorrência, à técnica de redução e às consequências de ignorar tal lesão. Lesões de impacto marginal devem ser diagnosticadas e tratadas corretamente para preservar a congruência articular; no entanto, o cirurgião deve estar ciente da possibilidade de um padrão incomum de impacto marginal no qual o fragmento poderia ser revertido; manter esta possibilidade em mente facilitaria seu diagnóstico e manejo.
Aero-thermal numerical characterization of blunt fin-induced shock wave–boundary layer interaction and its control through leading-edge cooling injection
Authors: Lozano Francisco , Saavedra Jorge , Paniagua Guillermo
Published: September 2022

This study represents a novel evaluation of active flow control to alleviate the aerothermal penalties created by the blunt fin-induced shock wave–boundary layer interaction. The manuscript analyzes the effect of flow injection on a blunt fin-induced shock wave–boundary layer interaction via computational fluid dynamics simulations with various degrees of resolution. The impact on the mean flow topology and wall variables was investigated utilizing Reynolds-averaged Navier–Stokes simulations. Detached-eddy simulations revealed the low-frequency shock motion, shock wave–boundary layer, and horseshoe vortex interaction. The test article was exposed to two different incoming boundary layer thicknesses; the thicker boundary layer led to the appearance of larger turbulent scales. The Detached-eddy simulations revealed the time history of the shock wave–boundary layer interaction, focusing on the inception and development of the recirculated flow regions. Ultimately, spectral proper orthogonal decomposition was employed to identify the structures associated with the low-frequency shock motion caused by the shock wave–boundary layer interaction.
Numerical investigations of electric field-mediated active droplet transfer in a ternary phase system
Authors: Dutta Satarupa , Gooh Pattader Partho Sarathi , Bandyopadhyay Dipankar
Published: September 2022

A method of active transport of a droplet from a carrier liquid to a target liquid is proposed with the aid of an electric field. Numerical investigations shed light on the dynamics associated with the active migration of a water droplet across the interface of two weakly conducting oils via application of an electric field. With the aid of two model ternary liquid systems, two modes of droplet transfer are identified—(i) the film drainage mode and (ii) the tailing mode. In the film drainage mode obtained for the model system of silicone oil–water–oleic acid, at low electric fields, the water droplets undergo negligible distortions in shape and the film drainage and rupture occur in a quasi-steady manner. At higher fields, the droplet distorts into a prolate with unsteady drainage and the film rupture. The rate of film drainage increases with the strength of the applied electric field. The tailing mode of droplet transport is achieved for very low interfacial tension between the carrier and the target liquids. For the model system of silicone oil–water–soybean oil, in the tailing mode, the droplet entrains carrier liquid approximately equal to 4.5 times its own volume into the target liquid with the length of the tail as high as eight times the drop radius. The interfacial tensions of the liquid pairs, densities, viscosities, and dielectric constants of the liquids comprising the ternary system are the key parameters influencing the dynamics of migrations. The phenomena may find applications in liquid–liquid extraction, micro-reactions, and ultra-low tensiometry.
Flow control using single dielectric barrier discharge plasma actuator for flow over airfoil
Authors: Sundaram Prasannabalaji , Sengupta Soumyo , Suman Vajjala K. , Sengupta Tapan K. , Bhumkar Yogesh G. , Mathpal Rakesh K.
Published: September 2022

The single dielectric barrier discharge (SDBD) plasma actuator has been developed in the present work for high-accuracy, high-performance computing of flow control applications. The present physics-based SDBD model is a significant improvement over the one developed by Bagade et al., [“Frequency-dependent capacitance–based plasma model for direct simulation of Navier–Stokes equation,” AIAA J. 55, 180–194 (2017)], which was used for planar geometry using sequential computation. Based on the physics of SDBD operation, phase-averaged fully developed body force over an ac cycle is computed and stored, which is reused. Thus, the intensive body force computations are bypassed in the new model, and the body force due to the SDBD plasma actuator is incorporated in the compressible Navier–Stokes equation that is solved in a body-fitted curvilinear coordinates. Here, the modified SDBD model enables performing large-scale simulations for the aerodynamic flow control at low speed and transonic flow past airfoils used in unmanned aerial vehicles and executive jets. The flow control by SDBD plasma actuation is finally compared with other forms of flow control strategies.
Principles to adapt financing mechanisms for fully integrated hybrid energy systems
Authors: Cox Jordan , Murphy Caitlin , Foss Andrew
Published: September 2022

As the electricity sector evolves, and as all energy types (thermal, electric, chemical, etc.) become more coupled, there has been increased interest to develop and deploy hybrid energy systems (HES). This work focuses on fully integrated HES, where there are multiple energy sources and multiple energy products, often coupled through a storage buffer. A significant amount of the available literature on this work describes technology pathways for fully integrated HES; however, it is unclear how financial institutions should treat these systems. Fully integrated HES represent an increase in complexity from their stand-alone counterparts, but they also potentially mitigate financial risk and provide value to the energy system, which has not yet been accounted for in financing mechanisms that could help to enable such systems. This paper provides some examples of fully integrated HES and proposes principles to help adapt financing to adequately capture the value of such systems.
Effects of Al on microstructure and mechanical properties of hot-extruded Mg–3Nd alloys
Authors: Yu Peichen , Wang Lei , Wang Liping , Feng Yicheng , Fu Yuanke , Zhao Sicong , Guo Erjun , Wang Zhiwei
Published: September 2022

The effects of Al content on microstructure, texture, and mechanical properties of as-extruded Mg–3Nd alloy were investigated. The particle stimulated nucleation effect of Al2Nd and Al11Nd3 phases promotes dynamic recrystallisation and the texture is weakened of the as-extruded alloys. With the increase in Al content in the alloys, the microstructure transformed from a bimodal structure to an almost fully recrystallised structure. Grain refinement, the distribution of the second phases, and texture are important factors determining the mechanical properties of as-extruded alloys. As-extruded Mg–3Nd–3Al achieved a good balance of strength and plasticity. The ultimate tensile strength, yield strength, and elongation are 283, 221.3 MPa, and 15.7%, respectively.
In-Plane Anisotropic Response to Uniaxial Pressure in the Hidden Order State of URu2Si2
Authors: Wang Xingyu , Gong Dongliang , Liu Bo , Ma Xiaoyan , Zhao Jinyu , Wang Pengyu , Sheng Yutao , Guo Jing , Sun Liling , Zhang Wen , Lai Xinchun , Tan Shiyong , Yang Yi-feng , Li Shiliang
Published: September 2022

We investigate the uniaxial-pressure dependence of resistivity for URu2−x
Fe
x
Si2 samples with x = 0 and 0.2, which host a hidden order (HO) and a large-moment antiferromagnetic (LMAFM) phase, respectively. For both samples, the elastoresistivity ζ shows a seemingly divergent behavior above the transition temperature T
0 and a quick decrease below it. We find that the temperature dependence of ζ for both samples can be well described by assuming the uniaxial pressure effect on the gap or certain energy scale except for ζ
(110) of the x = 0 sample, which exhibits a nonzero residual value at 0 K. We show that this provides a qualitative difference between the HO and LMAFM phases. Our results suggest that there is an in-plane anisotropic response to the uniaxial pressure that only exists in the hidden order state without necessarily breaking the rotational lattice symmetry.
Design and performance of a flexible broadband metamaterial absorbing structure fabricated based on the direct ink writing 3D printing
Authors: Shi Linghui , Xiao Xingzhi , Liu Tingting , Liao Wenhe , Kong Linghui
Published: September 2022

The method of three-dimensional (3D) printing significantly improves the design freedom of absorbing structures as these are fabricated under the layer-by-layer stacking mode. A four-layer gradient woodpile metamaterial absorbing structure (FGWMAS) based on the direct ink writing 3D printing (DIW3DP) is proposed. First, carbonyl iron powder/polydimethylsiloxane, which endows FGWMAS with outstanding flexibility, chemical and thermal stability, is prepared as the absorbing composites. The electromagnetic parameters are measured and used as inputs of the FGWMAS design. Additionally, the correlation is established between DIW3DP process parameters and the cross-sectional dimensions of the woodpile unit cell. Furthermore, the validity of the equivalent medium theory is verified, and it is utilised to realise the rapid design of FGWMAS. The thickness of each layer is optimised using genetic algorithms, and the optimised FGWMAS is obtained. The simulation results reveal that the maximum effective absorbing bandwidth of the proposed FGWMAS is up to 12.15 GHz (5.85–18 GHz) in the 1–18 GHz band range, and the minimum reflectivity is −37.91 dB at 10.95 GHz. This paper provides a new design and manufacturing method for metamaterial absorbing structures with micro unit cells. The DIW3DP flexible metamaterial absorbing structure has strong potential for conformal, low-cost, and customised application.
Modulating the microscopic lattice distortions through the Al-rich layers for boosting the ferroelectricity in Al:HfO2 nanofilms
Authors: Yao Lulu , Das Sambit , Liu Xin , Wu Kai , Cheng Yonghong , Gavini Vikram , Xiao Bing
Published: September 2022

Combining the experimental characterization with the large-scale density functional theory calculations based on finite-element discretization (DFT-FE), we address the stabilization of polar orthorhombic phases (o-HfO2) in Al:HfO2 nanofilms by means of the atomic registry distortions and lattice deformation caused by Al substitutional defects (AlHf) and Schottky defects (2AlHf + VO) in tetragonal phases (t-HfO2) or monoclinic phases (m-HfO2). The phase transformation directly from the t-HfO2 into polar o-HfO2 are also elucidated within a heterogeneous distribution of Al dopants in both t-HfO2 bulk crystal structure and Al:HfO2 nanofilm. It is revealed using large-scale DFT calculations that the Al substitutional defects (AlHf) or the Schottky defect (2AlHf + VO) could induce the highly extended atomic registry distortions or lattice deformation in the t- and m-HfO2 phases, but such effects are greatly diminished in ferroelectric orthorhombic phase. By purposely engineering the multiple AlHf defects to form dopant-rich layers in paraelectric t-HfO2 nanofilm or bulk crystal, the induced extended lattice distortions surrounding the defect sites exhibit the shearing-like atomic displacement vector field. The large-scale DFT calculations further predicted that the shearing-like microscopic lattice distortions could directly induce the phase transformation from the t-HfO2 into polar orthorhombic phase in both Al:HfO2 bulk crystal and nanofilms, leading to the large remanent polarization observed in Al:HfO2 nanofilms with the presence of Al-rich layers. The current study demonstrates that the ferroelectricity of HfO2 bulk crystal or thin film can be optimized and tuned by delicately engineering both the distribution and concentration of Al dopants in atomic layer deposition without applying the top capping electrode, providing the extra flexibility for designing the HfO2 based electronic devices in the future.
Investigation on dislocation and deflection morphology of PVT-grown on-axis 4H-SiC crystals
Authors: Li Huadong , Peng Yan , Yang Xianglong , Xie Xuejian , Chen Xiufang , Hu Xiaobo , Xu Xiangang
Published: September 2022

The morphologies of dislocation etch pits and dislocation deflections of on-axis 4H-SiC substrate etched by molten KOH were observed with the help of a microscope. Based on experimental observation and etch mechanism, a method for the identification of threading edge dislocations, threading screw dislocations (TSDs) and threading mixed dislocations was proposed. The details about the inner micro-structure of threading edge dislocations and TSDs were observed by laser scanning confocal microscope and scanning electron microscopy. The morphologies and the cross-sectional views of the basal plane dislocation formed by threading edge dislocation were observed and two models were formed to explain it.
Energy evolution of the overlap functions: increasing ratio of σ
el(s)/σ
tot(s) and black ring emergence
Authors: Troshin S M , Tyurin N E
Published: September 2022

We consider two possible options of the energy dependency of the elastic and inelastic overlap functions. Those correspond to saturation of the black disk limit (BEL effect) and to the unitarity saturation (REL effect) at s → ∞. Relation of the REL effect to increase of the ratio σ
el(s)/σ
tot(s) and emergence of black ring picture at the LHC is underlined.
Anomalous dielectric response in the triple perovskite ruthenate Ba3BiRu2O9
Authors: Kumar Jitender , Dey Kaustav , Panja Soumendra Nath , Nair Sunil
Published: September 2022

We have investigated the magnetic, dielectric and thermal properties of the S

R
u

= 1 magnetic dimer Ba3BiRu2O9, which is known to exhibit a spin-gap opening in conjunction with a first-order magneto-elastic phase transition at ∼175 K. Above the spin-gap temperature, the temperature dependence dielectric constant shows a peak like feature with pronounced frequency dependence. The critical slowing down behavior of this frequency dispersion suggests that a ferroelectric relaxor like electrical glassy state exists above the spin-gap opening temperature regime. The extermination of frequency dispersion—right at the magneto-elastic phase transition, is suggestive of a strong coupling between the lattice and charge-spin degrees of freedom in this triple perovskite system.
Excitonic instability in transition metal dichalcogenides
Authors: Martins Quintela M F C , Costa A T , Peres N M R
Published: September 2022

When transition-metal dichalcogenide monolayers lack inversion symmetry, their low-energy single particle spectrum near some high-symmetry points can, in some cases, be described by tilted massive Dirac Hamiltonians. The so-called Janus materials fall into that category. Inversion symmetry can also be broken by the application of out-of-plane electric fields, or by the mere presence of a substrate. Here we explore the properties of excitons in TMDC monolayers lacking inversion symmetry. We find that exciton binding energies can be larger than the electronic band gap, making such materials promising candidates to host the elusive exciton insulator phase. We also investigate the excitonic contribution to their optical conductivity and discuss the associated optical selection rules.
Can armchair nanotubes host organic color centers?
Authors: Eller Benjamin , Fortner Jacob , Kłos Jacek , Wang YuHuang , Clark Charles W
Published: September 2022

We use time-dependent density functional theory to investigate the possibility of hosting organic color centers in (6, 6) armchair single-walled carbon nanotubes, which are known to be metallic. Our calculations show that in short segments of (6, 6) nanotubes

∼
5

nm in length there is a dipole-allowed singlet transition related to the quantum confinement of charge carriers in the smaller segments. The introduction of

s

p
3

defects to the surface of (6, 6) nanotubes results in new dipole-allowed excited states. Some of these states are redshifted from the native confinement state of the defect-free (6, 6) segments; this is similar behavior to what is observed with

s

p
3

defects to exciton transitions in semiconducting carbon nanotubes. This result suggests the possibility of electrically wiring organic color centers directly through armchair carbon nanotube hosts.
Thermoelectric transport properties of XAgP (X = Sr and Ba) from first principles
Authors: Dhawan Rakshanda , Zeeshan Mohd , Nautiyal Tashi , van den Brink Jeroen , Kandpal Hem C
Published: September 2022

For thermoelectric applications those materials are of interest that have significant power factor (PF) and low lattice thermal conductivity,

κ

L

. Here we theoretically explore

κ

L

of two novel materials SrAgP and BaAgP using linearized Boltzmann transport equation with a single-mode relaxation time approach. We estimate the figure of merit zT by employing ab-initio calculations based on density functional theory and semiclassical Boltzmann transport theory. It is observed that at room temperature SrAgP exhibits slightly higher lattice thermal conductivity than BaAgP, which is mainly due to the large phonon group velocity. The relaxation time derived from deformation potential theory indicates a higher p-type PF for SrAgP compared to BaAgP over the entire temperature range. This provides an estimate for the figure of merit for the two materials. The low lattice thermal conductivity and higher PF make SrAgP a more promising thermoelectric material.
Early fault diagnosis of rolling bearings based on parameter-adaptive multipoint optimal minimum entropy deconvolution adjusted and dynamic mode decomposition
Authors: Xiong Manman , Lv Yong , Dang Zhang , Yuan Rui , Song Hao
Published: September 2022

Fault vibration signals of rolling bearings in early stages are affected by complex transmission paths and strong background noise, resulting in weak information about fault characteristics, which is difficult to extract clearly and accurately. To this end, a new diagnosis method for early faults of rolling bearings is proposed. First, the parameter-adaptive multipoint optimal minimum entropy deconvolution adjusted (PA-MOMEDA) algorithm is used to preprocess the fault signals by strengthening their shock components and weakening the influence of noise on their results. Second, the maximum envelope-spectrum characteristic energy ratio is employed as the selection criterion for the optimal truncation order of dynamic mode decomposition (DMD) to decompose and reconstruct the signals. Finally, the processed signals are subjected to the Hilbert envelope spectral transformation to accurately extract early fault characteristic frequencies. An analysis of simulated signals, public database signals, and bearing signals from a wind turbine has shown that the proposed PA-MOMEDA–DMD method can successfully extract the early fault characteristics of rolling bearings. Compared with the traditional pattern decomposition algorithms, the proposed method is much better at extracting fault characteristics and diagnosing early faults of rolling bearings. The facts have proved that the proposed method is promising in engineering applications.
Analysis of electrospinning and additive effect on β phase content of electrospun PVDF nanofiber mats for piezoelectric energy harvester nanogenerators
Authors: Oflaz Kamil , Özaytekin İlkay
Published: September 2022

Harvesting energy with piezoelectric nanoparticles enables the development of self-powered devices. Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF) has been widely used in a variety of fields due to its superior piezoelectric properties. PVDF’s piezoelectric performance is affected by the presence of polar phase in the crystalline structure. The electrospinning process was used in this study to achieve high β phase ratios in the PVDF crystalline structure using various additives (graphene, boron nitride, and quartz (SiO2)). The Taguchi experimental design method was used to determine the most significant parameters affecting β phase content from seven factors, as well as the optimal levels of the significant factors. The Fourier transform infrared, x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray and differential scanning calorimetry analyses were used to characterize the composite PVDF nanofiber mats produced under optimal conditions, and the output voltage was measured using an oscilloscope. The composite PVDF nanofiber mat with the highest β phase concentration demonstrated a maximum output voltage of 8.68 V under optimal conditions, indicating that it outperformed than pure PVDF under equal electrospinning conditions.
Electron transport in quantum channels with spin–orbit interaction: effects of the sign of the Rashba coupling and applications to nanowires
Authors: Gogin Leonid , Rossi Fausto , Dolcini Fabrizio
Published: September 2022

We investigate the effects of the sign of the Rashba spin–orbit coupling (RSOC) on electron transmission through a single-channel nanowire (NW) in the quantum coherent regime. We show that, while for a finite length NW with homogeneous RSOC contacted to two electrodes the sign of its RSOC does not affect electron transport, the situation can be quite different in the presence of an inhomogeneous RSOC and a magnetic field applied along the NW axis. By analyzing transport across an interface between two regions of different RSOC we find that, if the two regions have equal RSOC signs, the transmission within the magnetic gap energy range is almost perfect, regardless of the ratio of the spin–orbit energies to the Zeeman energy. In contrast, when the two regions have opposite RSOC signs and are Rashba-dominated, the transmission gets suppressed. Furthermore, we discuss the implementation on a realistic NW setup where two RSOC regions are realized with suitably coupled gates separated by a finite distance. We find that the low-temperature NW conductance exhibits a crossover from a short distance behavior that strongly depends on the relative RSOC sign of the two regions to a large distance oscillatory behavior that is independent of such relative sign. We are thus able to identify the conditions where the NW conductance mainly depends on the sign of the RSOC and the ones where only the RSOC magnitude matters.
Position-dependent mass with modulated velocity in 1-D heterostructures
Authors: Valencia-Torres R , Avendaño J , García-Ravelo J , Choreño E
Published: September 2022

We study the (1+1)-dimensional Dirac equation for charge carriers in some heterostructures. Both, the mass profile and the modulated Fermi velocity of the quasi-particle, are considered position dependent. We have used mass and Fermi velocity that admit only approximate analytical solutions. However, we also calculate numerically the exact energy spectra of each heterostructure through the corresponding reflection coefficient poles.
Effective field theory of black hole perturbations with timelike scalar profile: formulation
Authors: Mukohyama Shinji , Yingcharoenrat Vicharit
Published: September 2022

We formulate the Effective Field Theory (EFT) of perturbations within scalar-tensor theories on an inhomogeneous background. The EFT is constructed while keeping a background of a scalar field to be timelike, which spontaneously breaks the time diffeomorphism. We find a set of consistency relations that are imposed by the invariance of the EFT under the 3d spatial diffeomorphism. This EFT can be generically applied to any inhomogeneous background metric as long as the scalar profile is everywhere timelike. For completeness, we report a dictionary between our EFT parameters to those of Horndeski theories. Finally, we compute background equations for a class of spherically symmetric, static black hole backgrounds, including a stealth Schwarzschild-de Sitter solution.