bluuebunny/crossref_metadata_2025 huggingface dataset:
Reversible data hiding in encrypted images for coding channel based on adaptive steganography
Authors: Yu Kunliang , Chen Liquan , Wang Yu , Han Jinguang , Zhang Lejun
Published: February 2021

In this study, a novel reversible data hiding (RDH) in encrypted domain scheme for coding channel based on sliding‐block segmentation and adaptive steganography is proposed. The proposed scheme enriches the residual information with as little additional encryption information as possible to improve the testing error rate of a steganalyser by sliding‐block segmentation with bit stream encryption. The specific encryption process effectively weakens the correlation between the adjacent pixels and minimises the size of key stream bits. The encryption key can be further embedded in the channel code stream before transmitted in the channel. Experimental analysis shows that the image encrypted by the proposed RDH scheme can achieve a peak‐signal‐to‐noise ratio of >50 dB, as the payload is 0.5 bits per pixel (bpp). In terms of security performance, compared with the state‐of‐the‐art methods, their method has a higher testing error rate when the steganalyser is utilised. Even if the payload is 0.5 bpp, the testing error rate is >0.25.
KiDS-1000 Cosmology: Constraints beyond flat ΛCDM
Authors: Tröster Tilman , Asgari Marika , Blake Chris , Cataneo Matteo , Heymans Catherine , Hildebrandt Hendrik , Joachimi Benjamin , Lin Chieh-An , Sánchez Ariel G. , Wright Angus H. , Bilicki Maciej , Bose Benjamin , Crocce Martin , Dvornik Andrej , Erben Thomas , Giblin Benjamin , Glazebrook Karl , Hoekstra Henk , Joudaki Shahab , Kannawadi Arun , Köhlinger Fabian , Kuijken Konrad , Lidman Chris , Lombriser Lucas , Mead Alexander , Parkinson David , Shan HuanYuan , Wolf Christian , Xia Qianli
Published: February 2021

We present constraints on extensions to the standard cosmological model of a spatially flat Universe governed by general relativity, a cosmological constant (Λ), and cold dark matter (CDM) by varying the spatial curvature ΩK, the sum of the neutrino masses ∑mν, the dark energy equation of state parameter w, and the Hu-Sawicki f(R) gravity fR0 parameter. With the combined 3 × 2 pt measurements of cosmic shear from the Kilo-Degree Survey (KiDS-1000), galaxy clustering from the Baryon Oscillation Spectroscopic Survey (BOSS), and galaxy-galaxy lensing from the overlap between KiDS-1000, BOSS, and the spectroscopic 2-degree Field Lensing Survey, we find results that are fully consistent with a flat ΛCDM model with ΩK = 0.011−0.057+0.054, ∑mν < 1.76 eV (95% CL), and w = −0.99−0.13+0.11. The fR0 parameter is unconstrained in our fully non-linear f(R) cosmic shear analysis. Considering three different model selection criteria, we find no clear preference for either the fiducial flat ΛCDM model or any of the considered extensions. In addition to extensions to the flat ΛCDM parameter space, we also explore restrictions to common subsets of the flat ΛCDM parameter space by fixing the amplitude of the primordial power spectrum to the Planck best-fit value, as well as adding external data from supernovae and lensing of the cosmic microwave background (CMB). Neither the beyond-ΛCDM models nor the imposed restrictions explored in this analysis are able to resolve the ∼3σ tension in S8 between the 3 × 2 pt constraints and the Planck temperature and polarisation data, with the exception of wCDM, where the S8 tension is resolved. The tension in the wCDM case persists, however, when considering the joint S8 − w parameter space. The joint flat ΛCDM CMB lensing and 3 × 2 pt analysis is found to yield tight constraints on Ωm = 0.307−0.013+0.008, σ8 = 0.769−0.010+0.022, and S8 = 0.779−0.013+0.013.
Diagnostic Value of Ultrasound in Fatty Liver Disease
Authors: Karlas Thomas , Blank Valentin , Böhlig Albrecht
Published: February 2021

Hepatic steatosis is a commonly seen phenomenon in clinical practice and is the result of the accumulation of lipids in the hepatocytes. In most cases steatosis refers to nonalcoholic fatty liver disease (NAFLD), but it also occurs in other diseases of the liver parenchyma of a different etiology and is the result of the dysregulation of metabolic processes. Consequently, inflammatory processes can induce progressive fibrosis. Due to the high prevalence of fatty liver disease, a further increase in metabolic liver cirrhosis with corresponding complications can be expected in the near future. Due to its broad availability, ultrasound is particularly important, especially for the management of NAFLD. In addition to diagnosis and risk stratification, the monitoring of high-risk patients in NAFLD is becoming increasingly clinically important. Multimodality ultrasound includes B-mode and duplex methods, analysis of tissue stiffness (elastography), contrast-enhanced imaging (CEUS), and steatosis quantification. When using ultrasound in fatty liver disease, a standardized approach that takes into account the limitations of the method is essential.
Opioid Mortality Following Implementation of Medical Cannabis
Programs in the United States
Authors: Kaufman Daniel E. , Nihal Asawer M. , Leppo Janan D. , Staples Kelly M. , McCall Kenneth L. , Piper Brian J.
Published: February 2021

Introduction The United States is in the midst of an opioid overdose
epidemic. Emerging evidence suggests that medical cannabis (MC) may reduce use
of opioids for pain in some individuals, with potential impacts on
opioid-related overdose. However, there may be other important differences
between states that did, and did not, adopt MC.

Methods This study evaluated differences following legal MC sales on US
opioid-related overdose deaths, corrected for population, from 1999 to 2017
using an interrupted time series. Comparisons by MC status were also made for
Medicaid expansion and the Centers for Disease Control death certificate
reporting quality (0: <good, 1: good, 2: excellent).

Results Overdose deaths were significantly higher in MC states from
2012–2017. Overdose death slopes over time increased in states with
(pre=1.46±0.46, post=2.90±0.58, p<0.05)
and without (pre =0.20±.10, post=1.04±0.22,
p<0.005) MC. Post-legalization slopes were significantly higher in MC
states (p<0.01). Two states without (11.1%) as compared to 11
states with (91.7%) MC expanded Medicaid by 2014
(χ2[1]=19.03, p<0.0005). MC states
(1.50±0.23) had higher death certificate reporting quality relative to
states without MC (0.78±0.22, p<0.05).

Discussion MC states had higher rates of opioid overdoses. Although there
was no decrease in association with MC introduction, these results were
confounded by states without MC having lower overdose reporting quality.
Medicaid expansion was also more common in states with MC. Finally, the potency
of fentanyl analogues may have obscured any protective effects of MC against
illicit opioid harms.
Störungen der Chemosensorik bei Covid-19: Pathomechanismen und klinische Relevanz
Authors: Isenmann Stefan , Haehner Antje , Hummel Thomas
Published: February 2021

In dieser Übersichtsarbeit wurden aktuelle Angaben zu Häufigkeit und Relevanz chemosensorischer Störungen bei Covid-19 erfasst, pathophysiologisch zugeordnet und Aussagen zur prognostischen Bedeutung abgeleitet. Die Ergebnisse basieren auf einer umfassenden Literaturrecherche sämtlicher Literatur zu diesem Thema und eigenen Erfahrungen in der Behandlung von Patienten mit Riech- und Schmeckstörungen seit dem Beginn der Pandemie.

Bisherige Studienergebnisse deuten darauf hin, dass klinisch gering betroffene Covid-19-Patienten ohne stationäre Behandlungs- und Beatmungspflicht häufig Störungen der Chemosensorik aufweisen. Insbesondere bei jungen Patienten und Frauen scheinen sie ein Indikator einer günstigen Prognose des Krankheitsverlaufs zu sein. Riechstörungen können früh, isoliert oder als eines von mehreren Symptomen einer Covid-19-Erkrankung auftreten. Ob eine Ageusie eigenständig auftreten kann oder aber im Rahmen der Anosmie mit empfunden wird, ist noch nicht geklärt. In der Pandemie ist das neue Auftreten einer Anosmie ohne Kongestion / Obstruktion/Schnupfen wahrscheinlich Ausdruck einer Infektion mit SARS-CoV-2 und sollte stets zu Quarantäne und Testung auf SARS-CoV-2 Anlass geben. Die Riechstörung bei Covid-19 scheint meist vorübergehend zu sein; ob es regelhaft zu einer vollständigen Restitution kommt, kann noch nicht abschließend beurteilt werden. Die bereits bei anderen postviralen Riechstörungen etablierten Therapieansätze (z. B. Riechtraining) kommen auch hier zum Einsatz.
A Review of Minimally Invasive Techniques in Thoracolumbar Trauma
Authors: Raheja Amol , Tandon Vivek , Garg Kanwaljeet , Sinha Sumit
Published: February 2021

The development of endoscopy, microscopy, and image guidance system provided the impetus for the adoption of minimally invasive surgery (MIS) techniques in the management of spinal trauma patients. The underlying drive has been an attempt to achieve the functional and biomechanical goals inherent to trauma care but through MIS techniques. Broadly the MIS techniques for spinal trauma can be divided into two categories—fusion and nonfusion methods. Fusion methods include mini-open or keyhole approaches that allow for discectomy and/or corpectomy and cage reconstruction via an anterior/lateral/posterior operative corridor. The nonfusion methods primarily include percutaneous pedicle screw fixation, kyphoplasty, and vertebroplasty, all without placement of bone graft or other attempts at inducing arthrodesis. In this review article, we have stratified the MIS techniques based on the operative corridor used and briefly described the decision-making process, technical nuances, pros, and cons of each technique.
Minimally Invasive Management of Diverticular Disease
Authors: Madiedo Andrea , Hall Jason
Published: February 2021

Traditionally, management of complicated diverticular disease has involved open damage control operations with large definitive resections and colostomies. Studies are now showing that in a subset of patients who would typically have undergone an open Hartmann's procedure for Hinchey III/IV diverticulitis, a laparoscopic approach is equally safe, and has better outcomes. Similar patients may be good candidates for primary anastomosis to avoid the morbidity and subsequent reversal of a colostomy.

While most operations for diverticulitis across the country are still performed open, there has been an incremental shift in practice toward minimally invasive approaches in the elective setting. The most recent data from large trials, most notably the SIGMA trial, found laparoscopic sigmoid colectomy is associated with fewer short-term and long-term complications, decreased pain, improvement in length of stay, and maintains better cost-effectiveness than open resections. Some studies even demonstrate that robotic sigmoid resections can maintain a similar if not more reduction in morbidity as the laparoscopic approach while still remaining cost-effective.

Intraoperative approaches also factor into improving outcomes. One of the most feared complications in colorectal surgery is anastomotic leak, and many studies have sought to find ways to minimize this risk. Factors to consider to minimize incidence of leak are the creation of tension-free anastomoses, amount of contamination, adequacy of blood supply, and a patient's use of steroids. Techniques supported by data that decrease anastomotic leaks include preoperative oral antibiotic and mechanical bowel prep, intraoperative splenic flexure mobilization, low-tie ligation of the inferior mesenteric artery, and use of indocyanine green immunofluorescence to assess perfusion.

In summary, the management of benign diverticular disease is shifting from open, morbid operations for a very common disease to a minimally invasive approach. In this article, we review those approaches shown to have better outcomes, greater patient satisfaction, and fewer complications.
Trend Analysis of Head and Neck Neoplasms between 2012–2018 in Patients Residing in Al-Madinah, Saudi Arabia: A Retrospective Study
Authors: Alsharif Maha T. , Alsharif Alla T. , Krsoum Majid A. , Aljohani Mazen A. , Qadiri Osama M. , Alharbi Abdulkarim A. , Al-Maweri Sadeq A. , Warnakulasuriya Saman , Kassim Saba
Published: February 2021

Objectives This study sought to present a view of head and neck neoplasms (HNN) prevalence with specific focus on sociodemographic determinants in Al-Madinah Province, Saudi Arabia.

Materials and Methods This was a hospital-based retrospective study based on retrieval of histopathological data for a period of 6 years between 2012 and 2018. Data was collected from the archives of the Oral and Maxillofacial Pathology Laboratory at King Fahad Hospital (the only referral center for biopsy services) in Al-Madinah City.

Statistical Analysis An independent t-test and/or nonparametric (Mann–Whitney U test, chi-squared test) tests were used to determine the differences between groups. Statistical significance was set at the p-value < 0.05.

Results Out of 96 patients, a total of 58 patients had valid biopsy data with preoperative diagnosis. Over three quarters of the cases (n = 44) were benign with only 24% were malignant. Males were more likely to be diagnosed with a benign tumor than females (54.5 vs. 45.6%, respectively), and malignancy was also more common in males (64.3 vs. 24.1). A significant difference was found in relation to mean age of older patients who were more likely to be diagnosed with malignant tumors (p = 0.001).

Conclusions The findings suggest that most of biopsied HNN cases are benign neoplasms. Age is a significant risk factor for head and neck malignancy in this region. Delays in diagnosis of HNN need to be explored.
Preservation Rhinoplasty: Evolution and Current State of Practice in the United States
Authors: Patel Priyesh N. , Friedman Oren , Kandathil Cherian K. , Most Sam P.
Published: February 2021

Classic Joseph hump reduction techniques have been a hallmark of current rhinoplasty practice and teaching. Recently, there has been a renewed global interest in preservation rhinoplasty techniques, although these techniques are not new. The work and techniques of innovative surgeons including Goodale, Lothrop, and Cottle describing preservation concepts from the late nineteenth century and early twentieth century were not as prevalently adopted as open structural approaches. As such, there has been a relative paucity in both research and teaching of preservation techniques—particularly in the United States. A survey of members of the American Academy of Facial Plastic and Reconstructive Surgery and The Rhinoplasty Society (145 respondents) demonstrates that while 15 (10%) of surgeons are not at all familiar with dorsal preservation surgery, 130 (90%) were. In the group that was familiar with dorsal preservation, the majority were only somewhat familiar (84, 65%) with these techniques. Only 11 respondents received any formal training in dorsal preservation techniques during residency or fellowship. 61 (42%) had attended a course or conference in which dorsal preservation techniques were discussed. One-hundred twenty-two survey respondents (84.1%) do not currently implement preservation techniques into their rhinoplasty practice. Twelve (8%) respondents implement it in <25% of cases, 5 (3%) in 25 to 50% of cases, and 6 (4%) in >50% of cases. As research and formal training in preservation rhinoplasty grow, familiarity and implementation of these techniques will likely also grow in the United States.
Evaluation of the Secretor Status of ABO Blood Group Antigens in Saliva using Absorption Inhibition Method
Authors: Tejasvi M.L Avinash , Bukkya Jaya Laksmi , Rao Pandu Ranga , Bhayya Harsha
Published: February 2021

Objectives While DNA profiling has become the principal technique for individualization of biological evidences, ABO blood grouping is still a useful test method in the initial stages of crime investigation. Objectives of the study were blood group determination using slide agglutination method, blood group determination from saliva using absorption inhibition method, and comparison of slide agglutination method with that of absorption inhibition method from saliva sample.

Materials and Methods A total of 60 subjects were taken randomly with their age ranging from 20 to 60 years. Sixty subjects were divided in to two groups, study group and control group. 5 to 10 mL of unstimulated saliva was collected from 60 patients and Wieners agglutination test was performed to detect the secretor status of blood using absorption inhibition method and compared with that of slide agglutination method

Results Out of 60 subjects, 52 subjects showed secretors of antigen in saliva with percentage value of 86.66% and eight subjects were nonsecretors (13.33%). Slightly higher percentage of secretor status was seen in males 84.6 and 88.2% in females.

Conclusion Evaluation of secretor status of blood group antigen from saliva using absorption inhibition method can be useful method in identification of medicolegal cases.
History of Dorsum Conservative Techniques in Rhinoplasty: The Evolution of a Revived Technique
Authors: Arancibia-Tagle Diego , Neves José Carlos , D'Souza Alwyn
Published: February 2021

The correction and management of the nasal hump has been a classic problem in rhinoplasty since the beginning of the aesthetic purpose of this surgery. For many years, the resective technique described by Joseph has been the battle horse to solve this problem but it has several drawbacks if not done properly. In the late 19th and early 20th centuries, a new dorsal conservative technique was born and for several years was an alternative option to treat the same problem without damaging the keystone area while preserving the dorsal connection between the upper lateral cartilage and the septum. The aim of this article is to review the history and evolution of this technique, which has been reborn after several years, and how it has evolved since then.
Cytokine Profile in Children with Severe Multisystem Inflammatory Syndrome Related to the Coronavirus Disease 2019
Authors: Rodríguez-Rubio Miguel , Menéndez-Suso Juan J. , Cámara-Hijón Carmen , Río-García Miguel , Laplaza-González María , Amores-Hernández Irene , Romero-Gómez María P. , Álvarez-Rojas Elena , Salas-Mera Diana , López-Granados Eduardo , de la Oliva Pedro
Published: February 2021

The multisystem inflammatory syndrome in children (MIS-C) is a novel and concerning entity related to severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. Although MIS-C has been the subject of intensive research efforts, its pathophysiology and optimal treatment remain elusive. We studied the clinical features, laboratory findings, and immunoinflammatory profiles of seven children prospectively admitted to a pediatric intensive care unit (PICU) during the first wave of the pandemic. All patients had immunoglobulin (Ig)-G against SARS-CoV-2, four of seven patients had both IgM and IgG, and in one of the 7 SARS-CoV-2 was detected in a respiratory sample. All patients received intravenous fluid boluses (median: 15 mL/kg) and norepinephrine. The most common form of respiratory support was supplemental oxygen via nasal cannula. None of the patients needed mechanical ventilation. The cardiovascular system was frequently involved. All patients had an elevated troponin-I (median: 107.3 ng/L). Four out of seven patients had coronary artery abnormalities, and two of seven had both abnormal electrocardiogram (EKG) findings and evidence of left ventricular dysfunction on echocardiogram. Ig levels and complement function were normal. Peripheral blood phenotyping with flow cytometry showed decreased T-cell numbers at the expense of CD8+ T-cells. Cytokine profiling showed a heterogeneous increase in interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-18, IL-2Ra, IL-10, and IL-1Ra that tended to normalize after treatment. Our study shows that children with MIS-C have elevated plasma levels of pro- and anti-inflammatory cytokines in the acute phase of the disease without other relevant immunologic disturbances. These findings suggest the presence of a mixed antagonist response syndrome (MARS) similar to that present in pediatric sepsis. Combining a meticulous differential diagnosis with cautiously coordinated immunomodulatory therapy and high-quality supportive care can help clinicians avoid causing iatrogenic harm in patients with MIS-C.
Patient Satisfaction with Absorbable Anchoring Facial Threads
Authors: Ziade Georges , Daou Dayane , Karam Desiree
Published: February 2021

This study aimed to evaluate satisfaction in terms of facial appearance, quality of life, and adverse effects in patients undergoing the facial thread lifting procedure using the absorbable facial threads anchored on the superficial and deep temporal fascias. The charts of patients for whom facial anchored thread lifting was performed using absorbable threads between February 2017 and September 2019 were reviewed. Demographic data including age and gender as well as data from the Face-Q scales were collected. Descriptive analysis was made for the adverse effects 1 week after the procedure. The mean value of adverse effects scales was compared 1 and 2 weeks after the procedure and also the mean values of facial appearance and quality-of-life scales were compared at baseline, 6 months, and 12 months after the procedure. All recruited subjects were females with a mean age of 43.42 years. There was a statistically significant decrease in the rate of adverse effects following the procedure between the first and second week. The mean difference in patients' perceived age 6 and 12 months after the procedure was statistically significant when compared with baseline. The psychological distress significantly decreased and the psychological function improved 6 and 12 months after the procedure. The overall satisfaction with facial appearance increased significantly after 6 months with a mean of 20.08. This was maintained at 12 months. The satisfaction in skin appearance, cheeks, nasolabial folds, marionettes, lower face, and jawline appearances improved significantly 6 months after the procedure. This was also maintained at 12 months. Face lifting using the polycaprolactone threads anchored on the temporalis fascia showed a significant improvement in the quality of life and facial appearance. The adverse effects are tolerable starting 2 weeks after the procedure.
Prudential supervisory disclosure (PSD) with supervisory technology (SupTech): lessons from a FinTech crisis
Authors: Zeranski Stefan , Sancak Ibrahim E.
Published: February 2021

The U.S. financial markets faced an unprecedented rapid decline and recovery on May 6, 2010, known as the May 6 flash crash. Roughly one trillion $ market value in less than thirty minutes vanished with the biggest one-day point decline in the history of the DJIA at the time. Since the market events took place in electronic markets, and algorithmic trading and high-frequency trading, parts of FinTech, played significant roles, we handle the May 6 flash crash from the FinTech, SupTech, and financial supervision perspectives. With the flashback method, we analyzed the reactions of market participants, media, and two financial supervisors, the SEC, and the CFTC, to the market crash. We find that the technological imbalance between financial markets or institutions and their supervisors drove the markets in uncertainty, hence in a fear and panic environment. Since the imbalance has not diminished yet, the same risks still exist. As a remedy, we introduce a new concept and model with a well-functioning SupTech system to cope with the May 6 type FinTech crises.
Scalable chemical vapor deposited graphene field-effect transistors for bio/chemical assay
Authors: Rajesh  , Gao Zhaoli , Charlie Johnson A. T. , Puri Nidhi , Mulchandani Ashok , Aswal D. K.
Published: February 2021

The adsorption of chemical species on the surface of graphene alters the concentration of charge carries by either increasing or decreasing it depending on the nature of the adsorbed chemical species and inducing noticeable changes in the material's electronic properties. This remarkable feature enables graphene-based sensors to detect a wide range of biomolecules, chemicals, and gas/vapors. A lot of progress has been made in this field and technologies based on reduced graphene oxide flakes have been well reviewed. Graphene grown by chemical vapor deposition has proven to be the most prominent route to large-scale production of devices. However, until now, a comprehensive review on scalable, macro-sized, chemical vapor-deposited, graphene-based field-effect transistor sensors was missing. Here we review the present status, current challenges, and future prospects for the bio/chemical sensing applications of scalable, chemical vapor-deposited, graphene field-effect transistors. We explain and examine the fabrication techniques, sensing mechanisms, and various assay strategies. We also discuss the sensing performance of graphene based on quantum mechanics simulations and theoretical calculations.
Estimating winter wheat straw amount and spatial distribution in Qihe County, China, using GF-1 satellite images
Authors: Huawei Mou A. , Huan Li B. , Yuguang Zhou C. , Yongjun Zheng D. , Renjie Dong E. , Jinxin Cao F.
Published: February 2021

Crop straw is considered an important renewable energy source. China produces approximately one billion tons of crop straw annually, but 35% of this yield is not used effectively. In this study, a novel method for estimating the regional winter wheat straw yield was developed to promote straw resource recovery. Medium resolution (16 m) GF-1 satellite images of Qihe County were obtained. A weighted normalized difference vegetation index (WNDVI) image of winter wheat based on time-series normalized difference vegetation index values was generated by weighting samples to distinguish winter wheat from other land cover types, such as woodland, bare land, water, settlement, and other cultivated land. Four kernel functions of support vector machines (SVMs) were used for image classification. The linear kernel function with the highest accuracy was selected to construct the extraction model of the winter wheat plantation area in the Qihe County, Shandong Province, China, and the estimation method for total theoretical resources and spatial distribution of winter wheat straw in the region was established. The results show that the winter wheat straw in the Qihe County was mainly concentrated in the central and southern regions followed by the northern region; the central urban districts in the central-north region had the lowest straw concentration. The theoretical total quantity of straw resources of winter wheat in the county was 690 497 t; and the theoretical recoverable resource quantity was 504 063 t. The error between the estimated data and statistical data was only 1.27%, indicating that SVM and WNDVI can accurately identify winter wheat and estimate the spatial distribution of winter wheat straw in Qihe County.
Evolution of mesoscopic domain structure and macroscopic properties in lead-free Bi0.5Na0.5TiO3-BaTiO3 ferroelectric ceramics
Authors: Zhao Jinyan , Zhang Nan , Quan Yi , Niu Gang , Ren Wei , Wang Zhe , Zheng Kun , Zhao Yulong , Ye Zuo-Guang
Published: February 2021

Bismuth sodium titanate and related compounds are promising lead-free ferroelectric materials potentially useful in a wide range of piezoelectric applications. The domain structure plays an important role in determining the piezoelectric and ferroelectric properties and thereby the performance of electromechanical transducers. In this work, piezoresponse force microscopy (PFM) is used to gain insights into the mesoscopic-scale domain structure and its evolution under electric field in the (1−x)Bi0.5Na0.5TiO3-xBaTiO3 (BNT-BT) piezoceramics with compositions varying from x = 0 to x = 0.08. A phase transition from the rhombohedral phase to the tetragonal phase is observed with increasing BT contents. A relationship is established between the relaxor behavior and the domain structures imaged by PFM, i.e., short-range polar regions without visible domains in relaxor ceramics of pure BNT, while long-range ordered polar states with clear domains in ferroelectric ceramics with the addition of BT content. Distinct micro-domains are observed in the ceramics with compositions close to the morphotropic phase boundary (MPB), but the domain size drops to nanometers in the MPB composition with an increasing domain wall density. An electric field can induce the transformation from the relaxor behavior to a ferroelectric state, accompanied by an increase in domain sizes and a rearrangement/reorientation of the polar domains. This study of domain structure and its evolution in BNT-BT provides a better understanding of the relationship between the crystal structure, mesoscopic-scale domains, and macroscopic properties in these important lead-free piezoelectric ceramics.
Effect of alloying elements on the structure and mechanical properties of NbMoTaWX (X = Cr, V, Ti, Zr, and Hf) refractory high-entropy alloys
Authors: Liu Haibo , Liu Lei , Xin Cunlin
Published: February 2021

Numerous alloying elements can improve the mechanical properties of NbMoTaW refractory high-entropy alloys (RHEAs), but the relationship between the alloying of different elements and the changes in the microstructure and mechanical properties of RHEAs is ambiguous. The first principles based on density functional theory are used to calculate the lattice parameters, electronic properties, and elastic properties of NbMoTaW-based RHEAs to reveal the microstructure and mechanical properties of NbMoTaW RHEAs with alloying elements of the same period or subgroup. The melting point, lattice constant, and mass density of NbMoTaW-based RHEAs are controlled by the alloying elements such as Cr, V, Ti, Zr, and Hf. Valence electron concentration (VEC) is a key factor affecting the electronic structure and mechanical properties of NbMoTaW-based RHEAs. High VEC can improve the mechanical properties of RHEAs but reduce the ductility. Cr-alloying has a significant effect on mechanical properties of NbMoTaW RHEAs, and Ti has a significant effect on ductility. The orbital electronic interactions between the alloying elements and Nb, Mo, Ta, and W atoms shown by the density of states and electron density difference may explain the relationship between VEC and the mechanical properties of RHEAs. Our results provide the underlying insights needed to guide the design of NbMoTaW RHEAs with excellent mechanical properties.
Estimating COVID-19 exposure in a classroom setting: A comparison between mathematical and numerical models
Authors: Foster Aaron , Kinzel Michael
Published: February 2021

The COVID-19 pandemic has driven numerous studies of airborne-driven transmission risk primarily through two methods: Wells–Riley and computational fluid dynamics (CFD) models. This effort provides a detailed comparison of the two methods for a classroom scenario with masked habitants and various ventilation conditions. The results of the studies concluded that (1) the Wells–Riley model agrees with CFD results without forced ventilation (6% error); (2) for the forced ventilation cases, there was a significantly higher error (29% error); (3) ventilation with moderate filtration is shown to significantly reduce infection transmission probability in the context of a classroom scenario; (4) for both cases, there was a significant amount of variation in individual transmission route infection probabilities (up to 220%), local air patterns were the main contributor driving the variation, and the separation distance from infected to susceptible was the secondary contributor; (5) masks are shown to have benefits from interacting with the thermal plume created from natural convection induced from body heat, which pushes aerosols vertically away from adjacent students.
Weak localization and dimensional crossover in compositionally graded AlxGa1−xN
Authors: Al-Tawhid Athby , Shafe Abdullah-Al , Bagheri Pegah , Guan Yan , Reddy Pramod , Mita Seiji , Moody Baxter , Collazo Ramon , Sitar Zlatko , Ahadi Kaveh
Published: February 2021

The interaction between the itinerant carriers, lattice dynamics, and defects is a problem of long-standing fundamental interest for developing quantum theory of transport. Here, we study this interaction in the compositionally and strain-graded AlGaN heterostructures grown on AlN substrates. The results provide direct evidence that a dimensional crossover (2D–3D) occurs with increasing temperature as the dephasing scattering events reduce the coherence length. These heterostructures show a robust polarization-induced 3D electron gas and a metallic-like behavior down to liquid helium temperature. Using magnetoresistance measurements, we analyze the evolution of the interaction between charge carriers, lattice dynamics, and defects as a function of temperature. A negative longitudinal magnetoresistance emerges at low temperatures, in line with the theory of weak localization. A weak localization fit to near zero-field magneto-conductance indicates a coherence length that is larger than the elastic mean free path and film thickness (lφ>t>lel), suggesting a 2D weak localization in a three-dimensional electron gas. Our observations allow for a clear and detailed picture of two distinct localization mechanisms that affect carrier transport at low temperature.
Identification of tetracycline combinations as EphB1 tyrosine kinase inhibitors for treatment of neuropathic pain
Authors: Ahmed Mahmoud S. , Wang Ping , Nguyen Ngoc Uyen Nhi , Nakada Yuji , Menendez-Montes Ivan , Ismail Muhammad , Bachoo Robert , Henkemeyer Mark , Sadek Hesham A. , Kandil Enas S.
Published: February 2021

Significance

Chronic pain is one of the most pressing national healthcare problems, and as a result, chronic pain was named by the NIH as the “silent epidemic.” Consequentially, chronic pain has directly contributed to the disproportionate increase in opioid use in America. However, thus far, there has been little progress in discovery of alternative noninvasive therapeutics for chronic pain. The current report outlines the repurposing of three tetracyclines for treatment of neuropathic pain by targeting the catalytic domain of EphB1 kinase. These results can be readily applicable clinically for treatment of neuropathic pain and provide proof of concept for the development of molecules for targeting Eph/ephrin-mediated pathologies.
Identifying vital nodes by Achlioptas process
Authors: Qiu Zhihao , Fan Tianlong , Li Ming , Lü Linyuan
Published: February 2021

The vital nodes are the ones that play an important role in the organization of network structure or the dynamical behaviors of networked systems. Previous studies usually applied the node centralities to quantify the importance of nodes. Realizing that the percolation clusters are dominated by local connections in the subcritical phase and by global connections in the supercritical phase, in this paper we propose a new method to identify the vital nodes via a competitive percolation process that is based on an Achlioptas process. Compared with the existing node centrality indices, the new method performs overall better in identifying the vital nodes that maintain network connectivity and facilitate network synchronization when considering different network structure characteristics, such as link density, degree distribution, assortativity, and clustering. We also find that our method is more tolerant of noisy data and missing data. More importantly, compared with the unique ranking list of nodes given by most centrality methods, the randomness of the percolation process expands the possibility space of the optimal solutions, which is of great significance in practical applications.
Bilinear dynamic mode decomposition for quantum control
Authors: Goldschmidt Andy , Kaiser E , DuBois J L , Brunton S L , Kutz J N
Published: February 2021

Data-driven methods for establishing quantum optimal control (QOC) using time-dependent control pulses tailored to specific quantum dynamical systems and desired control objectives are critical for many emerging quantum technologies. We develop a data-driven regression procedure, bilinear dynamic mode decomposition (biDMD), that leverages time-series measurements to establish quantum system identification for QOC. The biDMD optimization framework is a physics-informed regression that makes use of the known underlying Hamiltonian structure. Further, the biDMD can be modified to model both fast and slow sampling of control signals, the latter by way of stroboscopic sampling strategies. The biDMD method provides a flexible, interpretable, and adaptive regression framework for real-time, online implementation in quantum systems. Further, the method has strong theoretical connections to Koopman theory, which approximates nonlinear dynamics with linear operators. In comparison with many machine learning paradigms minimal data is needed to construct a biDMD model, and the model is easily updated as new data is collected. We demonstrate the efficacy and performance of the approach on a number of representative quantum systems, showing that it also matches experimental results.
Numerical investigation of oxygen transport in the retinal artery with higher order accuracy by using seven and nine point finite difference technique: a comparative study
Authors: Raza Muhammad , Riaz Arshad , Hamid Abdul Haleem , Khan Sami Ullah , Siddiqui Muhammad Arshad
Published: February 2021

The model explains the special distribution of oxygen pressure, typically normal breathing pressure with time-dependent diffusion including depletion of oxygen by normal metabolism. The model considered here has four sections described as the inner retina, the outer retina, the fluid layer, and the choriocapillaris. The oxygen transportation is considered through these four layers with metabolism in each layer that consumes oxygen. For the numerical investigation of the diffusion model, the method of lines (MOL) with Runge–Kutta (RK4) method is implemented. For the spatial derivatives, the different 6th (seven-point) and 8th order (nine-point) finite difference schemes are used to achieve higher accuracy. Three various models are thoroughly focused in the study. The normal metabolism rate of oxygen through each layer is found in the first case while abnormal rate is predicted in the second case and in third case; the vision loss due to extensive stage of hypoxia is observed. The key finding of the study comes in terms of getting higher accuracy by seven-point and nine-point formula as compared to five-point formula. All the major results are tabulated and sketched diagrammatically.
Quantum non-linear effects in colliding light beams and interferometers
Authors: Hacyan S
Published: February 2021

Small corrections to the electromagnetic field in colliding light beams are evaluated taking into account the interaction of light with the quantum vacuum, as predicted by quantum electrodynamics. The nonlinear formulation of McKenna and Platzman (1963) is used. Possible implications for very energetic light beams and the radiation pressure in interferometers (e.g., gravitational waves detector) are considered. It is also shown that a head-on collision produces secondary waves along conical directions at angles

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1

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First-principles study of plasmons in doped graphene nanostructures*
Authors: Shu Xiao-Qin , Cheng Xin-Lu , Liu Tong , Zhang Hong
Published: February 2021

The operating frequencies of surface plasmons in pristine graphene lie in the terahertz and infrared spectral range, which limits their utilization. Here, the high-frequency plasmons in doped graphene nanostructures are studied by the time-dependent density functional theory. The doping atoms include boron, nitrogen, aluminum, silicon, phosphorus, and sulfur atoms. The influences of the position and concentration of nitrogen dopants on the collective stimulation are investigated, and the effects of different types of doping atoms on the plasmonic stimulation are discussed. For different positions of nitrogen dopants, it is found that a higher degree of symmetry destruction is correlated with weaker optical absorption. In contrast, a higher concentration of nitrogen dopants is not correlated with a stronger absorption. Regarding different doping atoms, atoms similar to carbon atom in size, such as boron atom and nitrogen atom, result in less spectral attenuation. In systems with other doping atoms, the absorption is significantly weakened compared with the absorption of the pristine graphene nanostructure. Plasmon energy resonance dots of doped graphene lie in the visible and ultraviolet spectral range. The doped graphene nanostructure presents a promising material for nanoscaled plasmonic devices with effective absorption in the visible and ultraviolet range.
Analysis of properties of krypton ion-implanted Zn-polar ZnO thin films*
Authors: Jiang Qing-Fen , Lian Jie , Ying Min-Ju , Wei Ming-Yang , Wang Chen-Lin , Zhang Yu
Published: February 2021

The optical properties of materials are of great significance for their device applications. Different numbers of krypton ions are doped into high-quality Zn-polar ZnO films fabricated by molecular beam epitaxy (MBE) on sapphire substrates through ion implantation. Krypton is chemically inert. The structures, morphologies, and optical properties of films are measured. The x-ray diffraction (XRD) spectra confirm the wurtzite structures of Zn-polar ZnO films. Atomic force microscopy (AFM) results show that the films have pit surface structure and higher roughness after Kr ion implantation. A detailed investigation of the optical properties is performed by using the absorption spectrum, photoluminescence (PL), and spectroscopic ellipsometry (SE). The absorption spectrum is measured by UV-visible spectrophotometer and the bandgap energy is estimated by the Tauc method. The results show that the absorption increases and the bandgap decreases after Kr ion implantation. Moreover, the Kr ion implantation concentration also affects the properties of the film. The ellipsometry results show that the films’ refractive index decreases with the Kr ion implantation concentration increasing. These results can conduce to the design and optimization of Kr ion-implanted polar ZnO films for optoelectronic applications.
Identification of unstable individuals in dynamic networks*
Authors: Duan Dongli , Chai Tao , Wu Xixi , Wu Chengxing , Si Shubin , Bian Genqing
Published: February 2021

To identify the unstable individuals of networks is of great importance for information mining and security management. Exploring a broad range of steady-state dynamical processes including biochemical dynamics, epidemic processes, birth–death processes and regulatory dynamics, we propose a new index from the microscopic perspective to measure the stability of network nodes based on the local correlation matrix. The proposed index describes the stability of each node based on the activity change of the node after its neighbor is disturbed. Simulation and comparison results show our index can identify the most unstable nodes in the network with various dynamical behaviors, which would actually create a richer way and a novel insight of exploring the problem of network controlling and optimization.
Experimental validation of theoretically predicted cut-off of L1–L3M4,5 transitions at Z
= 50 through measurements of fluorescence and Coster–Kronig yields for Sn and Sb
Authors: Kaur Sandeep , Ayri Vibha , Kumar Anil , Czyzycki M , Karydas A G , Puri Sanjiv
Published: February 2021

In the present work, we have deduced the fluorescence (ω
1, ω
2, ω
3) and Coster–Kronig (CK)(f
12, f
13, f
23) yields for Sn (Z = 50) and Sb (Z = 51) from the L
i
(i = 1–3) sub-shell x-ray intensities measured using the energy tunable synchrotron radiation employing the selective photoionization method. For both the elements, yields have been obtained using two sets of theoretical photoionization cross sections based on the non-relativistic Hartree–Fock–Slater (HFS) model and the self-consistent Dirac–Hartree–Fock (DHF) model. In case of Sb, we have obtained a third set of measured yields also by using the experimental photoionization cross sections evaluated from independent measurements of the mass-attenuation coefficients. The experimental yields for Sb are reported for the first time by us. We have compared the present deduced fluorescence and CK yields with the Dirac–Hartree–Slater model based values, the semi-empirical values tabulated by Krause and the earlier reported values. In case of Sn, using the DHF and the HFS model based photoionization cross sections, two sets of present measured L1 sub-shell fluorescence yields (ω
1) are found to be 0.039 ± 0.007 and 0.036 ± 0.003, and the CK yields (f
13) are found to be 0.428 ± 0.107 and 0.405 ± 0.028, respectively. In case of Sb, using three sets of the photoionization cross sections (DHF, HFS and recent experimental values), the ω
1 values are measured to be 0.042 ± 0.007, 0.040 ± 0.004 and 0.047 ± 0.005, and the CK yields are measured to be 0.343 ± 0.085, 0.297 ± 0.021 and 0.247 ± 0.022, respectively. The comparison of these present measured yields with the theoretical values provided a reliable experimental evidence indicating cut-off of the intense L1–L3M4,5 CK transitions at Z = 50.
Methods for detecting order-by-disorder transitions: the example of the Domino model
Authors: Bacry Hugo , Cugliandolo Leticia F , Tarzia Marco
Published: February 2021

Detecting the zero-temperature thermal order-by-disorder (ObD) transition in classical magnetic systems is notably difficult. We propose a method to probe this transition in an indirect way. The idea is to apply adequate and suitably engineered magnetic fields to transform the zero-temperature transition into a finite-temperature sharp crossover, which should be much easier to observe and characterise with usual laboratory methods. Such a crossover should constitute proof of existence of the ObD transition in the underlying unperturbed system.
Temperature Effects on Plasma Li-heparin and Transaminase Activity in Children Blood with Tetralogy of Fallot
Authors: Fadhilah F , Rahmawati I , Anggraeni N , Riyadi S A
Published: February 2021

Tetralogy of Fallot (TOF) is a congenital heart disease that is caused by four heart defects, namely VSD, overriding aorta, obstruction of the right ventricular outflow tract and right ventricle hypertrophy. These abnormalities, which affect the anatomic structure of the heart, cause poor oxygenated blood to be pumped out of the heart. Children have smaller veins than adults, which make obtaining blood sample much harder. An experimental design was utilized, which allows the researchers to manipulate one or more variables and measure the resultant effects on the dependent variables. The population in this study was all vein blood sample of paediatric patients under the age of ten in National Cardiovascular Centre Harapan Kita Jakarta with TOF. Eleven sample were choose randomly as the sample in this study. We took 3 millilitres of blood from each sample and gave Li-heparin. The samples were then stored for 30 minutes at 5° C, 22-25° C and 37 ° C. We then used these sample to conduct ALT and AST tests. Based on the results of these tests we conducted descriptive statistical analysis, the normality test, homogeneity test and ANOVA test. We found that there is no significant difference in the results of AST and ALT tests using the three different samples. This study aimed to examine the effects of different temperatures on the volume of Li-heparin plasma and transaminase activity in human blood with Tetralogy of Fallot. The highest plasma volume was obtained from the sample that was put 30 minutes at 37°C.