bluuebunny/crossref_metadata_2025 huggingface dataset:
Nucleotide Sequence Sharing between the Human Genome and Primers for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Detection
Authors: Kanduc Darja
Published: March 2022

This study shows that oligonucleotide sequences are shared between the human genome and primers that have been proposed/used for SARS-CoV-2 detection by polymerase chain reaction (PCR). The high level of sharing (namely, up to 19mer with a maximum number of gaps equal to 2) might bear implications for the diagnostic validity of SARS-CoV-2 detection by PCR.
Synergy-Based Motor Therapy Inducing Favorable Changes in Motor Function Components among Poststroke Subjects: A Single-Group Study
Authors: Pandian Shanta , Arya Kamal Narayan , Kumar Vikas , Joshi Akshay Kumar
Published: March 2022

Background Synergy is an outcome of multiple muscles acting in a synchronized pattern, controlled by the central nervous system. After brain insult, a set of deviated movement pattern emerges in the affected limb. The methods to train synchronization of muscles may diminish the deviated movement augmenting neuromotor control. The purpose of this investigation was to develop a synergy-based motor therapy (SBMT) protocol for the paretic upper limb in poststroke subjects. Further, the feasibility and effectiveness of the program was evaluated. .

Methods The design was Pretest–posttest single-group assessor-blinded trial. Department of occupational therapy of a national institute for persons with physical disabilities was the study site. There were 40 study subjects (23 men, ranging from 40 to 60 years, 18 subjects with hemorrhagic cerebrovascular accident, and > 6 months after the accident) exhibiting motor paresis of half side of the body. SBMT is a stage-specific regime based on the linkage between the deviated and usual muscle action. SBMT items were selected considering the strength and magnitude of the deviated motor components. The movement linkages were utilized to dissociate strong coupled components; for instance, forearm pronation-supination with elbow 90-degree flexion. Fugl-Meyer Assessment (upper extremity) (FMA-UE), Wolf Motor Function Test (WMFT), and Barthel Index (BI) were applied to quantify the motor status, motor functional ability of the upper extremity, and self-care activities, respectively.

Results All the enrolled subjects could perform their corresponding SBMT sessions. Posttreatment, FMA-UE improved significantly (p < 0.001) from mean of 26.30 (standard deviation [SD] 15.02) to 35.20 (SD 17.64). Similarly, the WMFT both time (in seconds) and quality also positively improved significantly (p < .001) from mean of 76.77 (SD 54.73) to 64.07 (SD 56.99) and 1.34 (SD 1.06) to 1.87 (SD 1.34), respectively. BI improved from 79.88 (SD 17.07) to 92.62 (SD 21.2) after the intervention (p < 0.001).

Conclusion SBMT protocol was a feasible and effective intervention to facilitate motor function components in chronic hemiparetic subjects. The regime could be considered as a potential intervention for stroke rehabilitation. Further trials and use of sophisticated measures are recommended to authenticate the outcome of this investigation.

Clinical Trial Registration Clinical Trial Registry of India as CTRI/2017/10/010162 on October 23, 2017 (retrospectively).
Closure of Transsplenic Access Tracts Using Tract Embolics: Success, Clinical Outcomes, and Complications in a Tertiary Center
Authors: Rigual David , Chen Isaac , Roberts Dustin L. , Sayre James , Srinivasa Ravi
Published: March 2022

Purpose The aim of the study was to evaluate the safety and effectiveness of transsplenic venous access closure.

Materials and Methods Twenty patients (mean age: 51.8 years; range: 28–72), underwent 21 transsplenic venous access procedures over 4 years in this retrospective study. Comorbidities, active hemorrhage, anticoagulation, coagulation parameters, platelets, indications for transsplenic access, needle gauge, sheath size, variceal embolization method, tract embolization method, bleeding complications, and transfusion requirements and additional procedures to manage bleeding complications were recorded.

Results Preprocedure comorbidities included portal hypertension (n = 18/20, 90%), portal vein thrombosis (n = 14/20, 70%), hemorrhage (n = 6/20, 30%), splenic vein thrombosis (n = 7/20, 35%), anticoagulation (n = 2/20, 10%), and sinistral portal hypertension (n = 2/20,10%). Mean baseline international normalized ratio was 1.3 (range: 1–1.9), platelets 122 (range: 18–492). Most common transsplenic access indications were gastric varices with nonpatent portosystemic shunt (n = 11/21, 52%) and portal vein targeting for transjugular intrahepatic portosystemic shunt (n = 8, 38%). Most common access sheath sizes were 4-French (n = 5, 24%) and 6-French (n = 6, 29%). Fifteen procedures (71%) involved variceal embolization. Transsplenic tracts were embolized with microfibrillar collagen alone (n = 7), coils and microfibrillar collagen (n = 8), or others (n = 6). Based on the Society of Interventional Radiology adverse event classification system, embolization complications included one major (splenic artery pseudoaneurysm and a splenic vein pseudoaneurysm) and three moderate (19%) adverse bleeding events, which required blood transfusion.

Conclusion Transsplenic venous access tract embolization is a safe and moderately effective method to achieve tract hemostasis, with an overall clinical failure rate of 20%.
The Association between Helicobacter Pylori Infection and Iron Deficiency Anemia in Children: A Systematic Review and Meta-Analysis
Authors: Hamdan Sara Z. , Hamdan Hamdan Zaki , Nimieri Mustafa , Adam Ishag
Published: March 2022

Objectives This study, comprising a systematic review and meta-analysis, was conducted to assess the association between Helicobacter pylori infection and the risk of iron deficiency anemia (IDA) in children.

Methods We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant published studies were searched in the databases. Retrieved studies were assessed for quality using the Modified Newcastle-Ottawa Scale for quality assessment. The “meta” package of statistical software “R 4.0.3 was used for statistical analysis.

Results Overall, 22 eligible studies (eight cross-sectional, six randomized control trials, five case-control, two surveys, and one cohort), including nine (40.9%) from Asia, four (18.1%) from America, four (18.1%) from Africa, four (18.1%) from Europe, and one (4.5%) from Australia with a total of 3,434 cases and 4,455 controls were included in this systematic review and meta-analysis. We found that H. pylori infection was associated with a high risk of IDA (odds ratio 1.70, 95% confidence interval 1.21 − 2.38) in a random-effects model. Meta-regression analysis showed that none of the investigated factors that may affect the prevalence of IDA reached statistical significance. There was statistically significant difference between results when studies were categorized according to the methods used to diagnose H. pylori and level of incomes based on World Bank classification. The GRADEpro Guideline Development Tool evidence for the risk of IDA was of a “moderate certainty.”

Conclusions This meta-analysis with a “moderate certainty” of evidence showed an association between H. pylori infection and a high risk of developing IDA in children.
Evaluation of Utilizing the Distinct Genes as Predictive Biomarkers in Late-Onset Alzheimer's Disease
Authors: Kenanoglu Sercan , Kandemir Nefise , Akalin Hilal , Gokce Nuriye , Gol Mehmet F. , Gultekin Murat , Koseoglu Emel , Mirza Meral , Dundar Munis
Published: March 2022

Alzheimer's disease (AD) is a neurodegenerative disease that is characterized by a devastating decline in cognitive activities among all types of dementia, and it severely affects the quality of life. Late-onset AD (LOAD) occurs after the age of 65 years and develops sporadically. Although aging comes first along the main risk factors underlying LOAD, disease-causing susceptibility genes have been associated with disease pathogenesis. In our study, we included the genes PARP1, POLB, HTRA2, SLC1A2, HS1BP3, and DRD3 to be investigated in LOAD patients based on their expression levels. Within this framework, we aimed to determine the possible functions of these genes in the pathophysiology of the disease. We investigated whether the utilization of these genes as biomarkers in the early diagnosis of LOAD may help the treatment scheme to be applied in the clinic. We involved 50 individuals in the study and collected peripheral blood samples from the patients and control groups for molecular genetic analysis. Subsequently, RNA was extracted from the peripheral blood samples, and expression analyzes were performed using qualitative reverse transcription polymerase chain reaction. The results obtained were evaluated by using proper statistical methods. Our results demonstrated that there was no difference between patient and control groups in terms of HTRA2, DRD3, HS1BP3, and POLB genes. The expression levels of the SLC1A2 and PARP1 genes were significantly lower in the patient group compared with the control group. In conclusion, we presume that the PARP1 and SLC1A2 genes can be utilized as molecular biomarkers for LOAD.
Epidemiology of Meniscus Injuries in the Military Health System and Predictive Factors for Arthroscopic Surgery
Authors: Tropf Jordan G. , Colantonio Donald F. , Tucker Christopher J. , Rhon Daniel I.
Published: March 2022

Meniscus injuries occur at a higher rate in the military than the general population. Appropriate management and rehabilitation of meniscus injuries is important for maintaining readiness. The purpose of this study was to describe the health burden of meniscus injuries in the Military Health System (MHS) to identify the surgical intervention rate for meniscus injuries, and to determine which injury characteristics and demographic variables were associated with the likelihood of surgery after injury. The U.S. Department of Defense Management Analysis and Reporting Tool, a database of health care encounters by military personnel and dependents, was queried for encounters associated with a meniscal injury diagnosis between January 1, 2010, and December 31, 2011. Meniscus injuries were categorized into (1) isolated medial, (2) isolated lateral, (3) combined medial and lateral, and (4) unspecified cohorts. Patients under 18 and over 51 years were excluded, as well as patients without records at least 1 year prior to diagnosis or 2 years after. Relevant surgical procedures were identified with the Current Procedural Terminology (CPT) codes for arthroscopic surgery of the knee, meniscus repair, meniscectomy, and anterior cruciate ligament (ACL) reconstruction. There were 2,969 meniscus injuries meeting inclusion criteria during the study period. There were 1,547 (52.1%) isolated medial meniscus injuries, 530 (17.9%) isolated lateral meniscus injuries, 452 (15.3%) involved both menisci, and 435 (14.7%) were unspecified. The mean age was 35.5 years (standard deviation [SD] = 9.3). An adjacent ligamentous injury occurred in 901 patients (30.3%). The treatment course led to arthroscopic surgery in 52.8% (n = 1,568) of all meniscus injuries. Eighty-five percent (n = 385) of combined medial and lateral tears, 54.9% of medial tears, and 51.6% of lateral tears underwent surgery. Partial meniscectomy was the most common procedure performed while 47.2% (n = 1,401) of tears were not treated surgically. Bilateral meniscus injuries had 4.57 greater odds of undergoing knee arthroscopy (95% confidence interval [CI]: 3.46, 6.04), 2.42 times odds of undergoing a meniscus repair, and 4.59 times odds for undergoing a meniscus debridement (95% CI: 3.62, 5.82). The closed nature of the MHS allows reliable capture of surgical rates for meniscus injuries within the military population. Meniscus injuries are common in the military and impose a significant burden on the MHS. Appropriate management and rehabilitation of this injury is important for maintaining readiness.
Ultrasonographic Diagnosis of Twin-to-Twin Transfusion Syndrome
Authors: Reyna-Villasmil Eduardo , Briceño-Pérez Carlos , Briceño-Sanabria Juan C.
Published: March 2022

Introduction Twin-twin transfusion syndrome (TTTS) is a typical complication of monochorionic twin pregnancies (MCTP). Placental vessels that communicate in the chorionic plate between donor and recipient, are responsible for the imbalance of blood flow. Circulatory imbalance causes hypovolemia in donor and hypervolemia in recipient fetus. In a typical case, recipient fetus develops polyhydramnios, weight gain, cardiomegaly and hydrops fetalis. In contrast, donor fetus develops oligohydramnios and fetal growth restriction.

Aim The objective of this review is to evaluate in detail the main diagnostic aspects and add other important data for diagnosis of TTTS.

Scientific bases The main diagnostic event for this condition is based on the ultrasonographic discovery of oligohydramnios-polyhydramnios sequence. Other useful elements for diagnosis, staging and prognosis are fetal urinary bladder visualization, urinary bladder volumen measurements, edema of subcutaneous and/or generalized tissue edema, Doppler flow velocity waves and cardiac evaluation.

Conclusion Considerations regarding diagnosis of TTTS make it possible to emphasize that role of physicians treating patients with MCTP is to identify ultrasound sequence of oligohydramnios-polyhydramnios. Other ultrasonographic fetal data as fetal urinary bladder visualization, urinary bladder volumen measurements, edema of subcutaneous and/or generalized tissue edema, Doppler flow velocity waves and cardiac evaluation; may help diagnosis, staging and prognosis of TTTS. It is their responsibility to accurately assess severity, therapeutic possibilities and prognosis.

Key Points
Breakdown characteristics of deep-ultraviolet Al0.6Ga0.4N p-i-n avalanche photodiodes
Authors: Jeong Hoon , Cho Minkyu , Xu Zhiyu , Mehnke Frank , Bakhtiary-Noodeh Marzieh , Detchprohm Theeradetch , Shen Shyh-Chiang , Otte Nepomuk , Dupuis Russell D.
Published: March 2022

A top-illuminated deep-ultraviolet Al0.6Ga0.4N p-i-n avalanche photodiode (APD) structure was designed and grown by metalorganic chemical vapor deposition on an AlN bulk substrate and on two different quality AlN/sapphire templates, and APDs were fabricated and tested. The APD devices with a circular diameter of 20 μm have demonstrated a distinctive reverse-bias breakdown behavior. The reverse breakdown voltage of the APDs is approximately −140 V, which corresponds to a breakdown electric field of 6–6.2 MV/cm for the Al0.6Ga0.4N material as estimated by Silvaco TCAD simulation. The APDs grown on the AlN bulk substrate show the lowest leakage current density of <1 × 10−8 A/cm2 (at low reverse bias) compared to that of the devices grown on the AlN templates. From the photocurrent measurement, a maximum gain (current limited) of 1.2 × 104 is calculated. The average temperature coefficients of the breakdown voltage are negative for APD devices fabricated from both the AlN bulk substrate and the AlN templates, but these data show that the coefficient is the least negative for the APD devices grown on the low-dislocation-density AlN bulk substrate.
Synthesis and characterization of large-sized monolayer MoS2 nanoflakes by sulfurization of exfoliated MoO3 powder
Authors: Zhu Zusong , Zhu Dequan , Jiang Guisheng , Zhang Lihua , Zhan Shengbao , Wen Jun , You Jiancun
Published: March 2022

We demonstrate a novel approach based on sulfurization of MoO3 powder pre-exfoliated on the SiO2/Si substrate to synthesize high crystalline quality and large-sized monolayer MoS2 films uniformly covering the whole substrate. The surface morphology, thickness, crystalline quality, and luminescence mechanism of the MoS2 films were characterized by the optical microscopy, Raman spectroscopy, and photoluminescence spectroscopy. The results reveal that MoS2 films directly synthesized on the bare SiO2/Si substrate by our method have high surface coverage superior over those of one-step chemical vapor deposition (CVD) method and exhibit uniform monolayer with larger lateral length up to ∼120 µm compared to those of the traditional two-step CVD method. Our proposed growth strategy opens up new pathways for CVD synthesis of high crystalline quality and large-sized uniform monolayer MoS2 films and can also be utilized for synthesizing other two-dimensional materials.
Visualization of synchronization zone on the Bloch sphere through an anti-PT-symmetric electrical circuit
Authors: Kim M. , Yang Y. , Gui Y. S. , Hu C.-M.
Published: March 2022

This work reports an analysis of the anti-parity-time (APT) symmetry system produced by pure dissipative coupled passive electric oscillators. Through spectral and time-domain measurements, the complex eigenfrequencies of the APT-symmetric system were measured. Interesting physics, such as exceptional points, APT-symmetry breaking transitions, and frequency synchronization with explicitly defined phase differences, were observed. Most importantly, we found that synchronous signals span the equator of the Bloch sphere. Therefore, our methodology functions as an analogon understructure to explore APT-symmetric systems.
Influence of anomalous perpendicular transport on linear tearing mode dynamics in tokamak plasmas
Authors: Fitzpatrick R.
Published: March 2022

The analysis of a previous paper [A. Cole and R. Fitzpatrick, Phys. Plasmas 13, 032503 (2006)] that maps out all of the two-fluid response regimes of a linear tearing layer interacting with an externally generated resonant magnetic perturbation, in a large aspect-ratio tokamak plasma, is generalized to take into account realistic levels of perpendicular particle transport. A new response-regime map is obtained that differs substantially, in many respects, from the old one. The improved analysis is first employed to find all of the two-fluid growth-rate regimes of a non-interacting low-mode-number tearing mode in a large aspect-ratio tokamak plasma. The analysis is then used to determine the scaling of the error-field penetration threshold with machine parameters in large aspect-ratio tokamak plasmas.
Enstrophy dissipation of the tip leakage vortex in a multiphase pump
Authors: Shu Zekui , Shi Guangtai , Dan Yue , Wang Binxin , Tan Xiao
Published: March 2022

Tip clearance is the distance required between the blade tip and the pump body wall of the impeller in the multiphase pump, of which the resulting tip leakage vortex (TLV) causes unstable flow, leading to energy dissipation. However, only a few studies have been made on the energy dissipation caused by the TLV, and the internal mechanism of energy dissipation has not been revealed. In the present work, enstrophy dissipation theory is innovatively applied to quantitatively study the energy dissipation of the TLV in impeller, to provide guidelines for controlling energy dissipation associated with the TLV, and to optimize the design of the multiphase pump. The location, mode, and energy dissipation rate caused by the TLV are analyzed. The relationship between vorticity and the enstrophy dissipation rate is summarized, and the energy dissipation law is revealed during the inception, development, and dissipation of the TLV. The present analysis indicates that the vorticity is highest at the core of the TLV and gradually weakens along the radial direction with the vortex core at the center; the enstrophy dissipation, however, presented the opposite distribution law. The enstrophy dissipation rate changes as the spatialtemporal evolution of the TLV. The gas phase significantly deteriorates the flow pattern of the TLV, enhances the volume enstrophy dissipation rate, and reduces the wall enstrophy dissipation rate. The volume enstrophy dissipation power increases by 45.33% with an inlet gas void fraction of 10%, the wall enstrophy dissipation power decreases by 23.90%, and the total enstrophy dissipation power increases by 17.21%.
Experimental investigation of instability of fluid mud layer under surface wave motion
Authors: Aleebrahim Mohammad Ali , Jamali Mirmosadegh
Published: March 2022

Motivated by environmental impacts of surface-wave induced mixing of fluid mud with clear water in nearshore areas, this paper presents quantitative measurements of excitation of interfacial waves over a bed mud layer by a surface wave in a wave flume. After an initial fluidization process, a quasi-standing interfacial wave comprised of four interfacial waves was observed at the interface as a result of a resonant wave interaction with the surface wave. The interfacial waves were subharmonic to the surface wave and traveled at the maximum possible angle from it. The growth rate and kinematic properties of the interfacial waves were measured, and good agreement with theoretical predictions of a two-layer interaction model was obtained. It was found that excitation of these waves was highly dependent on the surface wave height and fluid mud viscosity. Furthermore, thickening of the lutocline layer as a result of resuspension of fluid mud highly influenced the wavelengths as well as the damping rate of the interfacial waves.
Hysteresis in a two-liquid whirlpool
Authors: Naumov Igor V. , Skripkin Sergey G , Gusev Grigoriy E. , Shtern Vladimir N.
Published: March 2022

This experimental study reveals a curious phenomenon—hysteresis in a lab-scale two-liquid flow. The rotating bottom disk drives a toroidal circulation of water–glycerin solution (lower fluid) and sunflower oil (upper fluid) in a vertical cylindrical container. As the rotation speeds up, the solution–oil interface and the oil–air (free) surface deform rising near the sidewall and depressing near the axis as typical of whirlpools. We choose that the oil–solution volume ratio be small (having in mined oil-pollution applications) but not too small (for convenient observation). As the rotation speeds up, the oil separates from the sidewall and collects in the solution funnel. Next, the interface touches the bottom, and this is the point of no return. The centrifugal force pushes the near-bottom oil to the periphery and the buoyancy pushes oil upward. The Rayleigh–Taylor instability breaks the interface, and oil droplets disperse in the solution. If before this breakdown, the rotation starts to decrease, the oil separates from the bottom at the angular velocity ω being remarkably smaller than that for which the oil touches the bottom. Therefore, the hysteresis is a capillary-induced phenomenon.
Multi-phase field model simulation based on MPI+OpenMP parallel: Evolution of seaweed and dendritic structure in directional solidification
Authors: Gao Zihao , Zhu Changsheng , Qi Meiling , Wang Canglong , Wang Yinlong , Zhao Borui
Published: March 2022

A multi-phase model was established to imitate the growth of algal and dendritic grains during directional solidification. We studied the effects of temperature on the growth of bi-crystals and quantitatively analyzed the influence of anisotropic strength, thermal gradient, and pulling velocity on the evolution of bi-crystals. The results show that both weaker anisotropy strength and smaller pulling velocity can maintain the formation of seaweed tissue. The increase in the pulling velocity can degenerate the seaweed grains into dendrites and improve the growth rate of the dendrites, which make grain B produce more spindles, thereby accelerating the elimination of grain A. The thermal gradient is inversely proportional to the average initial spacing of dendrites. When the thermal gradient is too small, dendritic dendrites produce developed secondary dendrite arms, which, in turn, develop into tertiary dendrite arms to occupy the grain boundary, accelerating the elimination of seaweed grains. In addition, the multi-phase field model is solved by using central processing unit serial computation, single MPI (message passing interface) parallel programming method calculation, and MPI+OpenMP hybrid parallel programming structure, and the relevant factors affecting the efficiency of program operation are analyzed and tested. By comparing the computational efficiency of the three methods, it can be seen that the MPI+OpenMP hybrid parallel programming technology can make full use of computing resources in the case of large computing scale, further optimize the MPI parallel model, and obtain a higher acceleration ratio.
Functional analysis of human brain endothelium using a microfluidic device integrating a cell culture insert
Authors: Miura Shigenori , Morimoto Yuya , Furihata Tomomi , Takeuchi Shoji
Published: March 2022

The blood-brain barrier (BBB) is a specialized brain endothelial barrier structure that regulates the highly selective transport of molecules under continuous blood flow. Recently, various types of BBB-on-chip models have been developed to mimic the microenvironmental cues that regulate the human BBB drug transport. However, technical difficulties in complex microfluidic systems limit their accessibility. Here, we propose a simple and easy-to-handle microfluidic device integrated with a cell culture insert to investigate the functional regulation of the human BBB endothelium in response to fluid shear stress (FSS). Using currently established immortalized human brain microvascular endothelial cells (HBMEC/ci18), we formed a BBB endothelial barrier without the substantial loss of barrier tightness under the relatively low range of FSS (0.1–1 dyn/cm2). Expression levels of key BBB transporters and receptors in the HBMEC/ci18 cells were dynamically changed in response to the FSS, and the effect of FSS reached a plateau around 1 dyn/cm2. Similar responses were observed in the primary HBMECs. Taking advantage of the detachable cell culture insert from the device, the drug efflux activity of P-glycoprotein (P-gp) was analyzed by the bidirectional permeability assay after the perfusion culture of cells. The data revealed that the FSS-stimulated BBB endothelium exhibited the 1.9-fold higher P-gp activity than that of the static culture control. Our microfluidic system coupling with the transwell model provides a functional human BBB endothelium with secured transporter activity, which is useful to investigate the bidirectional transport of drugs and its regulation by FSS.
Magnetic-field and temperature dependence of anomalous Hall effect in Pt/Cr2O3/Pt trilayer
Authors: Wang Xinrui , Toyoki Kentaro , Nakatani Ryoichi , Shiratsuchi Yu
Published: March 2022

The Pt/Cr2O3 interface exhibits a variety of spin-related phenomena. In this study, we investigated the anomalous Hall effect (AHE) of a Pt/40-nm-thick Cr2O3/Pt trilayer grown on Al2O3(0001), where Cr2O3 is an antiferromagnetic (AFM) insulator. All layers were grown epitaxially on the substrate, and X-ray reflectivity measurement showed an interfacial roughness of approximately 0.2 nm at each interface. The AHE resistance showed a nonlinear magnetic-field dependence at 300 K. Below 250 K, a clear hysteresis with coercivity was observed. The coercivity was approximately 7 T above 150 K and approximately 6 T below 100 K. The remanent AHE resistance shows a finite value below 285 K. The temperature dependence forms a broad peak with a maximum at approximately 200 K and gradually decreases with decreasing temperature. This temperature dependence is similar to that reported for the interfacial magnetic moment on Cr2O3(0001). Based on these results, the remanent AHE coupled with the AFM order parameter or the Néel vector was successfully detected in the 40-nm-thick Cr2O3 layer grown on the conductive layer.
Structural, magnetic, and Mössbauer spectroscopic study of La3+ and Cu1+ co-doped M-type strontium hexaferrite
Authors: Kim Hyung Joon , Yoon Sunghyun
Published: March 2022

Effects of La3+ and Cu1+ co-doping on the structural and the magnetic properties of M-type strontium hexaferrite have been studied by using crystallographic and magnetic measurements. Stoichiometric samples have been prepared by a conventional ceramic technique with repeated sintering at 1300 °C for 24 hours in the air. XPS Cu 2p scan shows that dominant valence state of Cu is +1. Analyses of the hysteresis curve reveals that MS increases and HC decreases with La-Cu content x. Room temperature Mössbauer spectral analysis indicates that Cu1+ preferentially replaces Fe3+ at 4f2 site, which is consistent with the increase of MS with respect to the La3+-Cu1+ co-doping.
Study of effective particle shape-dependent magnetization behavior of soft magnetic polymeric composites
Authors: Kiarie Winnie M. , Sitarski Dylan , Jiles David C.
Published: March 2022

This reports an investigation of the effect of magnetic particles with same chemical composition but different aspect ratios on the effective magnetization response of magnetorheological elastomers (MREs). MREs are composites that consist of magnetically permeable particles dispersed in a non-magnetic polymeric matrix. These materials are known for the tunability of their magnetoelastic properties. When subjected to an externally applied magnetic field, changes occur in their mechanical properties such as stiffness; this is the so-called magnetorheological (MR) effect. This is usually attributed to the magnetic interactions between the magnetic filler particles. Several factors significantly influence the MR effect. These are the polymer matrix, volume fraction, size, and shape of the magnetic particles. In this study, based on continuum formulation theory, microscale modeling using a finite element analysis (FEA) was used to determine the effect of the latter on the macroscopic magnetization of MREs. Using Jiles-Atherton hysteresis model parameters, the hysteresis loops of MRE were numerically resolved in the FEA software COMSOL Multiphysics. The model calculations were performed for randomly oriented (unaligned) and aligned microstructures with constant particle-volume fraction (φ= ∼20%) and varying particle-aspect ratios (AR=1, 2.5, 5 and 7.5). A computational homogenization scheme was used to relate the microscopic behavior to the macroscopic properties of these composites. From the analysis, it was found that for unaligned MRE the effective magnetization increased with increase in the particle aspect ratio, particularly in the linear region, while the saturation magnetization is seen to be independent of the particle shape. The effect is much more noticeable for particles aligned with the applied field, while for particles aligned perpendicular to the applied field an opposite effect is seen, where increasing aspect ratio results in decreased magnetization relative to the applied field.
Latin American early childhood education and social vulnerability links to toddlers’ executive function and early communication (La educación temprana en Latinoamérica y las relaciones de la vulnerabilidad social con las funciones ejecutivas y la comunicación temprana en la primera infancia)
Authors: Gago-Galvagno Lucas G. , Miller Stephanie E. , De Grandis María C. , Elgier Ángel M.
Published: March 2022

Several studies have analysed the impact of attending early childhood education centres on communication, regulatory skills and social-emotional development. These educational institutions have increased in presence annually, partially due to the access of women to the labour market. It has been found that infant education may modulate development in vulnerable contexts (typically associated with negative cognitive outcomes), although the results are contradictory. We presented a study that evaluated Latin American dyads of mothers–infants aged 18 to 24 months regarding the influence of infant education and social vulnerability on Executive Functions (EF) and Communication Skills (CS). To address these goals, toddlers completed several EF tasks and the Early Social Communication Scales. Parents completed the Socioeconomic Level Scale from INDEC. Results revealed that social vulnerability was associated with both EF and CS, daycare attendance was positively related to CS and finally, the contribution of daycare varied by SES on EF. These findings highlight the importance of considering infant education and socioeconomic status to generate equal opportunities from the first months of life.
Influence of punch diameter on impression creep behaviour of AZ91 magnesium alloy
Authors: Khoubrou I. , Nami B. , Miresmaeili S.M.
Published: March 2022

The influence of punch diameter on impression creep behaviour of the AZ91 alloy in the cast and wrought conditions was studied. The stress exponents of 5.3–7.8 and 1.8–2.6 were found, respectively, for the cast and wrought alloy, and the activation energy is close to the lattice diffusion of magnesium for both conditions. The punch diameter has no influence on the deformation mechanisms and the obtained creep data introduce lattice diffusion-controlled dislocation climb and grain boundary sliding, which are the dominant deformation mechanisms during creep of the cast and wrought alloys, respectively. The punch diameter affected the impression creep behaviour of the alloys so that with an increase in the punch diameter, the steady-state impression rate in both deformation mechanisms was increased exponentially.
In situ cryo-electron tomography reveals local cellular machineries for axon branch development
Authors: Nedozralova Hana , Basnet Nirakar , Ibiricu Iosune , Bodakuntla Satish , Biertümpfel Christian , Mizuno Naoko
Published: March 2022

Neurons are highly polarized cells forming an intricate network of dendrites and axons. They are shaped by the dynamic reorganization of cytoskeleton components and cellular organelles. Axon branching allows the formation of new paths and increases circuit complexity. However, our understanding of branch formation is sparse due to the lack of direct in-depth observations. Using in situ cellular cryo-electron tomography on primary mouse neurons, we directly visualized the remodeling of organelles and cytoskeleton structures at axon branches. Strikingly, branched areas functioned as hotspots concentrating organelles to support dynamic activities. Unaligned actin filaments assembled at the base of premature branches accompanied by filopodia-like protrusions. Microtubules and ER comigrated into preformed branches to support outgrowth together with accumulating compact, ∼500-nm mitochondria and locally clustered ribosomes. We obtained a roadmap of events supporting the hypothesis of local protein synthesis selectively taking place at axon branches, allowing them to serve as unique control hubs for axon development and downstream neural network formation.
COOMET.PR-S1 Comparison of whiteness and brightness. Final report
Authors: Shirokov S S , Khlevnoy B B , Ivashin E A , Gorshkova T B , Tarasova O B , Scums D V , Kupko A D , Huriev M V
Published: March 2022

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Final report on the supplementary comparison EURAMET.AUV.V-S1
Authors: Rosenkranz Peter , Virovska Daniela , Prasil Milan , Ribeiro Luis Filipe , Maina Anderson K , Hof Christian , Hämäläinen Jussi , Bruns Thomas , Sadikoglu Enver
Published: March 2022

Main text

The Supplementary comparison EURAMET.AUV.V-S1 has been carried out within the framework of the CIPM MRA. The specific task of this comparison is the measurement of the magnitude and phase of the sensitivity of single-ended accelerometers in the medium frequency domain (10 to 10 000 Hz). The sensitivity is calculated as the ratio of the amplitude of the output of the accelerometer to the amplitude of the acceleration at its reference surface with secondary means in accordance with ISO 16063-21 "Methods for the calibration of vibration and shock transducers - Part 21: Vibration calibration by comparison to a reference transducer". The participating NMIs are BEV (Austria), BIM (Bulgaria), CMI (Czech Republic), IPQ (Portugal), KEBS (Kenya), METAS (Switzerland) and MIKES (Finland). BEV (Austria) was the pilot laboratory of the comparison. The measurements took place between October 2019 and February 2021. Three single-ended accelerometers were circulated. The final report includes the measurement results from the participants, information about their calibration methods, and the analysis leading to the assignation of equivalence degrees.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
A joint ranking statistic for multi-messenger astronomical searches with gravitational waves
Authors: Piotrzkowski Brandon , Baylor Amanda , Hernandez Ignacio Magaña
Published: March 2022

Joint ranking statistics are used to distinguish real from random coincidences, ideally considering whether shared parameters are consistent with each other as well as whether the individual candidates are distinguishable from noise. We expand on previous works to include additional shared parameters, we use galaxy catalogues as priors for sky localization and distance, and avoid some approximations previously used. We develop methods to calculate this statistic both in low-latency using HEALPix sky maps, as well as with posterior samples. We show that these changes lead to a factor of one to two orders of magnitude improvement for GW170817-GRB 170817A depending on the method used, placing this significant event further into the foreground. We also examined the more tenuous joint candidate GBM-GW150914, which was largely penalized by these methods. Finally, we performed a simplistic simulation that argues these changes could better help distinguish between real and random coincidences in searches, although more realistic simulations are needed to confirm this.
The pseudoharmonic oscillator energy spectrum
Authors: Baykal Melek , Baykal Ahmet
Published: March 2022

The solution to the one dimensional Schrodinger equation for the potential of type x
2 + αx
−2, for positive values of the constant α is discussed using an operator method by factorizing the Hamiltonian.
Structural evolution of granular cubes packing during shear-induced ordering
Authors: Ding Yunhao , Yang Jing , Ou Yao , Zhao Yu , Li Jianqi , Hu Bingwen , Xia Chengjie
Published: March 2022

Packings of granular particles may transform into ordered structures under external agitation, which is a special type of out-of-equilibrium self-assembly. Here, evolution of the internal packing structures of granular cubes under cyclic rotating shearing has been analyzed using magnetic resonance imaging techniques. Various order parameters, different types of contacts and clusters composed of face-contacting cubes, as well as the free volume regions in which each cube can move freely have been analyzed systematically to quantify the ordering process and the underlying mechanism of this granular self-assembly. The compaction process is featured by a first rapid formation of orientationally ordered local structures with faceted contacts, followed by further densification driven by free-volume maximization with an almost saturated degree of order. The ordered structures are strongly anisotropic with contacting ordered layers in the vertical direction while remaining liquid-like in the horizontal directions. Therefore, the constraint of mechanical stability for granular packings and the thermodynamic principle of entropy maximization are both effective in this system, which we propose can be reconciled by considering different depths of supercooling associated with various degrees of freedom.
On the dynamically arrested states of equilibrium and non-equilibrium gels: a comprehensive Brownian dynamics study
Authors: Torres-Carbajal Alexis , Ramírez-González Pedro E
Published: March 2022

In this work a systematic study over a wide number of final thermodynamic states for two gel-forming liquids was performed. Such two kind of gel formers are distinguished by their specific interparticle interaction potential. We explored several thermodynamic states determining the thermodynamic, structural and dynamic properties of both liquids after a sudden temperature change. The thermodynamic analysis allows to identify that the liquid with short range attraction and long range repulsion lacks of a stable gas–liquid phase separation liquid, in contrast with the liquid with short range attractions. Thus, although for some thermodynamic states the structural behavior, measured by the static structure factor, is similar to and characteristic of the gel phase, for the short range attractive fluid the gel phase is a consequence of a spinodal decomposition process. In contrast, gelation in the short range attraction and long range repulsion liquid is not due to a phase separation. We also analyze the similarities and differences of the dynamic behavior of both systems through the analysis of the mean square displacement, the self part of the intermediate scattering function, the diffusion coefficient and the α relaxation time. Finally, using one of the main results of the non-equilibrium self-consistent generalized Langevin equation theory (NE-SCGLE), we determine the dynamic arrest phase diagram in the volume fraction and temperature (φ vs T) plane.
What’s better for our health? Conducting protective actions during a nuclear emergency or accepting a certain radiation dose?
Authors: Callen-Kovtunova J , McKenna T , Steinhauser G
Published: March 2022

The threat caused by ionising radiation has resulted in the establishment of strict radiation protection guidelines. This is especially true for severe nuclear power plant (NPP) accident scenarios, which may involve the release of significant amounts of ionising radiation. However, we believe that the fine balance between the benefit of a certain protective action (e.g. evacuation) and its risks is not always accounted for properly. Deaths and mental health problems have been associated with protective actions (e.g. evacuation) implemented in the response to the Fukushima Daiichi (NPP) accident in 2011. The protective actions were implemented consistent with international recommendations, to reduce radiation-induced health effects, even though the off-site effective doses were too low to indicate that there would be any discernible radiation-induced health effects. In this paper, we will provide a first step for the development of tools to evaluate the risk of protective actions versus the radiation-induced health risk. Over 50 papers were selected as useful from more than 600 reviewed papers to characterise the health impact of protective actions taken during different emergencies (including, technical and natural emergencies). An analysis was performed comparing the radiation-induced health effects averted by protective actions with the health effects associated with the protective actions. We concentrated our analysis on deaths and mental health problems associated with protective actions compared with the inferred radiation-induced deaths averted by the protective actions. Our analysis is stated in terms of absolute risk (cases per 1000) of health effects to allow for a direct comparison. It indicates that taking protective actions consistent with dose criteria typically used in many countries could result in more excess deaths than the inferred radiation-induced deaths prevented, as well as resulting in mental health problems. We identified that residents of facilities for long stays and the elderly are particularly vulnerable and a significant number of the deaths among the general public are associated with a lack of emergency preparedness provisions.
New operational dose quantity ambient dose H* in the context of galactic cosmic radiation in aviation
Authors: Matthiä Daniel , Meier Matthias M , Schennetten Kai
Published: March 2022

Abstract

The International Commission on Radiation Units and Measurements recently proposed new operational quantities for external radiation exposure. Among those, the ambient dose is intended to replace the ambient dose equivalent as estimator for the effective dose. Following its definition, the measurement of the ambient dose requires a much more detailed knowledge about the radiation field than the ambient dose equivalent. The implications for radiation protection in aviation concerning galactic cosmic radiation that would follow the adoption of the ambient dose as operational quantity at flight altitudes were investigated in this work using model calculations. It was found that the ambient dose is about 10% higher than the ambient dose equivalent for conditions relevant in commercial aviation and overestimates the effective dose by about 30%.
Phase stability of the argon crystal: first-principles study based on random phase approximation plus renormalized single excitation corrections
Authors: Yang Sixian , Ren Xinguo
Published: March 2022

The energy differences between the face-centered cubic (fcc) and hexagonal closed packed (hcp) structures of the argon (Ar) crystal are studied using the first-principles electronic-structure approach at the level of random phase approximation (RPA) plus renormalized single excitation (rSE) correction. By treating both structures at equal footing (i.e., employing the same computational supercell and k grid sampling), our RPA+rSE calculations show that, at zero temperature, the fcc structure is lower in energy than the hcp structure over a wide pressure range. The influence of zero-point energy (ZPE) is also studied and it is found that ZPE only plays a secondary role in determining the relative stability of the two structures, whereas the electron correlation effect dominates. We further examine the equation of states in the high pressure regime, and our RPA+rSE results, complemented with phonon contributions, show excellent agreement with available experimental data. Finally, by computing the Gibbs free energies for both the fcc and hcp at different temperatures, we are able to generate a T–P phase diagram for the Ar crystal, disclosing the pressure–temperature range for each phase. Our calculations show that the fcc phase has a slightly larger entropy and volume than hcp phase at the temperature and pressure condition.
Dark energy from inspiraling
in field space
Authors: Anguelova Lilia , Dumancic John , Gass Richard , Wijewardhana L.C.R.
Published: March 2022

We find an exact solution of the equations of motion of a two-field cosmological model, which realizes multi-field dark energy. The latter is characterized by field-space trajectories with turning rates that are always large. We study a class of two-field models and show that it is possible to have such trajectories, giving accelerated space-time expansion, even when the scalar potential preserves the rotational invariance of the field-space metric. For the case of Poincaré-disk field space, we derive the form of the scalar potential compatible with such background solutions and, furthermore, we find the exact solutions analytically. Their field-space trajectories are spirals inward, toward the center of the Poincaré disk. Interestingly, the functional form of the relevant scalar potential is compatible with a certain hidden symmetry, although the latter is broken by the presence of a constant term.
Tunable 2.3–3 μm optical vortex parametric laser
Authors: Wang Shutong , Tulake Yusufu , Sulaiman Dulikun , Ababaike Mairihaba , Miyamoto Katsuhiko , Omatsu Takashige , Yusufu Taximaiti
Published: March 2022

We generate a tunable (2.3–3 μm) optical vortex output with an order of 1 or 2 from a 1 μm optical-vortex-pumped singly resonant parametric oscillator based on a Mg doped periodically poled lithium niobate crystal. The orbital angular momentum (OAM) from the pump vortex beam was transferred to the mid-infrared idler output in this signal singly resonant high-Q cavity configuration. A maximum vortex output energy of 1.52 mJ was achieved within a wavelength tuning range of 2.27–2.96 µm. The signal beam with the Gaussian spatial profile was also generated within a 1.66–2 μm tuning range. The wide spectral bandwidth was experimentally measured near the wavelength degeneracy and explained by theoretically.