bluuebunny/crossref_metadata_2025 huggingface dataset:
A secure data transmission and efficient data balancing approach for 5G‐based IoT data using UUDIS‐ECC and LSRHS‐CNN algorithms
Authors: Yadav Kusum , Jain Anurag , Alharbi Yasser , Alferaidi Ali , Alkwai Lulwah M. , Ahmed Nada Mohamed Osman Sid , Hamad Sawsan Ali Saad
Published: January 2022

Due to the realization of 5G technology, the Internet of things (IoT) has made remarkable advancements in recent years. However, security along with data balancing issues is proffered owing to IoT data's growth. The universally unique identifier short input pseudo‐random (SiP) hash‐based elliptic curve cryptography (UUDIS‐ECC) centred secure data transfer (DT) and linear scaling Rock Hyraxes swarm‐based convolutional neural network (LSRHS‐CNN) centred 5G IoT data balancing are proposed here to address those issues. Authentication, destination selection, validation, secure DT, and also load balancing are the proposed method's five phases. Initially, during the registration phase, the Length Nano ID (LNanoID) is created in the authentication. The user is permitted to further communicate if the LNanoID is matched with the already saved LNanoID. The destination is selected if the user is authorized. Utilizing the sender and the receiver's public key, the hash code is produced in the validation centre by the SiP hash function after destination selection. After that, by employing the UUDIS‐ECC algorithm, the IoT data is safely transmitted towards the destination. The 5G IoT data is balanced by using the LSRHS‐CNN algorithm during DT. Superior results are attained by the proposed methods analogized to existing research methods.
Forecast of transmission line clearance using quantile regression‐based weather forecasts
Authors: Karimi Soheila , Dawson Leanne , Musilek Petr , Knight Andrew M.
Published: January 2022

This paper uses dynamic thermal line rating methods and a probabilistic prediction methodology to forecast line clearance and conductor temperature and evaluate the risk of clearance encroachment. A transient model is used to predict conductor temperature at different prediction levels. Clearance is estimated using a relationship model, developed based on historical measured clearance and conductor temperature data. Additional sensitivity analysis is performed to determine the applicability of ambient‐adjusted predictions when considering a lightly loaded line compared to a heavily loaded line. The developed methodology enables utilities to make decisions on line loading in advance of real‐time operation with information on confidence associated with that decision.
Impact of renewable energy integration on a novel method for pricing incentive payments of incentive‐based demand response program
Authors: Nguyen Duc Tuyen , Tran Thanh Son , Do Van Long , Tran Quoc Ngu , Takano Hirotaka
Published: January 2022

With the desire to improve the efficiency and the reliability of the power system as well as the advancement of smart meter and communication networks, the demand response (DR) program has been facilitated to become a key component in the smart grid. Many current researches focus on incentives‐based DR research orientation. In addition, accurately quantifying the incentive payment is also a significant challenge because of the fact that the incentive payment is currently determined depending on knowledge, experience, and experimental results. This paper presents a method of pricing incentive payments for the incentive‐based DR program through social welfare maximization framework which ensures the benefits of all participants involved. Besides, this study also proposed the quantification of incentive payments by a theoretical approach based on the satisfaction level of electricity consumers which is approximated through a fuzzy logic model. Moreover, the impact of renewable energy sources on the pricing mechanism and benefits of all parties participating in the DR program is also discussed through the calculation cost for renewable energy integration and emission cost function. The results show the validity and feasibility of the method.
Improving visual multi‐object tracking algorithm via integrating GM‐PHD and correlation filter
Authors: Yang Jinlong , Ni Peng , Miao Jiani , Ge Hongwei
Published: January 2022

The traditional visual multi‐object tracking methods based on the Gaussian mixture probability hypothesis density filter are generally not well adapted for tracking the targets in the complex scenarios, where there are a large number of unknowable newborn objects and occluded objects, even some missing objects cannot be associated with their previous trajectories when they are redetected. An improved visual multi‐object tracking algorithm is proposed by integrating an improved efficient convolution operator of the correlation filter and the Gaussian mixture probability hypothesis density filter. First, a similarity matrix based on the intersection‐of‐union is proposed for classifying the objects of survival objects, newborn objects, and then the improved efficient convolution operator method is employed to further identify whether the objects disappear or are missing. Moreover, the feature pyramid similarity is proposed to update the objects for enhancing the tracking accuracy. Finally, compared with some challenging methods on some challenging video sequences from publicly available MOT17 dataset, the proposed Gaussian mixture probability hypothesis density–feature pyramid similarity—efficient convolution operator* method has a good performance on detecting the newborn objects, occluded objects, blurring objects and re‐identifying the missing objects with higher multiple object tracking accuracy.
Channel splitting attention network for low‐light image enhancement
Authors: Lu Bibo , Pang Zebang , Gu Yanan , Zheng Yanmei
Published: January 2022

Low‐light enhancement is a crucial task in computer vision because of the limited dynamic range of digital imaging devices in poor lighting conditions. Images taken under low‐light conditions often suffer from insufficient brightness and severe noise. At present, many models based on convolutional neural networks have been proposed to enhance low‐light images. However, most models treat the features on different channels equally, which is not conducive to models learning hierarchical features. Consequently, the method proposed a channel splitting attention network (CSAN) that divides the shallow features into two branches, the residual and dense branches, transmitting different information. Residual branching facilitates feature reuse, while dense branching promotes the exploration of new features. In addition, CSAN uses merge‐and‐run mappings to assist information integration between different branches and distinguishes the information contained in different branch features through an attention module designed in this paper. Multiple experiment results show that the method proposed is superior to state‐of‐the‐art methods in qualitative and quantitative evaluation. Furthermore, CSAN can better suppress chromaticity aberration while enhancing low‐light images.
Case report – Selective internal radiation therapy (SIRT) in a patient with hyperinsulinemic hypoglycemia due to a metastatic insulinoma with late onset of endocrine activity
Authors: Henker Robert , Lincke Thomas , Hoffmeister Albrecht
Published: January 2022

Insulinomas are the most common functioning pancreatic neuroendocrine tumors (NET), which can lead to hyperinsulinemic hypoglycemia. In advanced metastatic stages of the disease, the prognosis is poor. Patients with hormonally active insulinomas primarily present with features of neuroglycopenia. Transformation from a nonfunctional to a functional NET is rare. Here, we present a case of a 59-year-old male adult with a metastatic insulinoma and late onset of endocrine activity. Besides medical treatment with Diazoxide and small frequent feedings, continuous intravenous glucose application was eventually required to avoid hypoglycemia. Furthermore, we show that selective internal radiation therapy (SIRT) can be an effective therapeutic approach for symptom reduction in advanced metastatic disease.
SARS-CoV-2 vaccination does not induce relapses of patients with inflammatory bowel disease
Authors: Elkharsawi Ahmed , Arnim Ulrike von , Schmelz Renate , Sander Cornelia , Stallmach Andreas , Teich Niels , Walldorf Jens , Reuken Philipp A.
Published: January 2022

Background Vaccination against SARS-CoV-2 is a promising strategy to protect immunocompromised IBD patients from a severe course of COVID-19. As these patients were excluded from initial clinical vaccination trials, patients frequently express concerns regarding the safety of these vaccines, especially whether vaccination might trigger IBD flares (“hit-and-run-hypothesis”).

Methods In order to assess the risk of an IBD flare after vaccination against SARS-CoV-2, an anonymous survey was performed at five German IBD centers and one patient organization (Deutsche Morbus Crohn/Colitis ulcerosa Vereinigung (DCCV) e.V.) in August and October 2021.

Results The questionnaire was answered by 914 patients, 781 of whom reported a previous vaccination against SARS-CoV-2 (85.4%). Vaccination against SARS-CoV-2 was not associated with an increased risk of IBD flares (p=0.319) or unscheduled visits to the IBD physician (p=0.848). Furthermore, typical symptoms of an IBD flare including abdominal pain, increases in stool frequency, or rectal bleeding were not influenced by the vaccination.

Conclusion Vaccination against SARS-CoV-2 is safe in IBD patients. These results may help to reduce fears regarding the vaccination in IBD patients. Our results can help to reduce fears in IBD patients regarding the SARS-CoV-2 vaccine. A close communication between patients and physicians before and after the vaccination may be beneficial.
Severe alcoholic hepatitis as precipitant for organ failure and ACLF
Authors: Trebicka Jonel , Louvet Alexandre , Arroyo Vicente , Jalan Rajiv , Shah Vijay H. , Moreau Richard
Published: January 2022

Alcoholic hepatitis is the acute deterioration of alcoholic liver disease with rapid onset or worsening of jaundice, which in severe cases, may transition to acute-on-chronic liver failure with extremely high short-term mortality, increasing with the number and severity of hepatic and extra-hepatic organ dysfunction. Diagnosis and treatment are insufficient and challenging, especially due to the complex, multi-factorial and as yet not fully understood pathogenesis. While current management is limited to steroids and best supportive care, debate is ongoing concerning liver transplantation for selected patients, and several novel approaches are under way with mixed results. These drawbacks in disease management together with increasing prevalence in Germany, and generally in Western countries, constitute an unmet need for the healthcare systems. This review tries to summarize the current status of these aspects and provides an overview for pathogenesis, management and potential future treatments.
Inflammation in alcohol-associated liver disease progression
Authors: Lotersztajn Sophie , Riva Antonio , Wang Sai , Dooley Steven , Chokshi Shilpa , Gao Bin
Published: January 2022

Chronic alcohol consumption induces stress and damage in alcohol metabolising hepatocytes, which leads to inflammatory and fibrogenic responses. Besides these direct effects, alcohol disrupts intestinal barrier functions and induces gut microbial dysbiosis, causing translocation of bacteria or microbial products through the gut mucosa to the liver and, which induce inflammation indirectly. Inflammation is one of the key drivers of alcohol-associated liver disease progression from steatosis to severe alcoholic hepatitis. The current standard of care for the treatment of severe alcoholic hepatitis is prednisolone, aiming to reduce inflammation. Prednisolone, however improves only short-term but not long-term survival rates in those patients, and even increases the risk for bacterial infections. Thus, recent studies focus on the exploration of more specific inflammatory targets for the treatment of severe alcoholic hepatitis. These comprise, among others interference with inflammatory cytokines, modulation of macrophage phenotypes or targeting of immune cell communication, as summarized in the present overview. Although several approaches give promising results in preclinical studies, data robustness and ability to transfer experimental results to human disease is still not sufficient for effective clinical translation.
Liver specific, systemic and genetic contributors to alcohol-related liver disease progression
Authors: Schnabl Bernd , Arteel Gavin E. , Stickel Felix , Hengstler Jan , Vartak Nachiket , Ghallab Ahmed , Dooley Steven , Li Yujia , Schwabe Robert F.
Published: January 2022

Alcohol-related liver disease (ALD) impacts millions of patients worldwide each year and the numbers are increasing. Disease stages range from steatosis via steatohepatitis and fibrosis to cirrhosis, severe alcohol-associated hepatitis and liver cancer. ALD is usually diagnosed at an advanced stage of progression with no effective therapies. A major research goal is to improve diagnosis, prognosis and also treatments for early ALD. This however needs prioritization of this disease for financial investment in basic and clinical research to more deeply investigate mechanisms and identify biomarkers and therapeutic targets for early detection and intervention. Topics of interest are communication of the liver with other organs of the body, especially the gut microbiome, the individual genetic constitution, systemic and liver innate inflammation, including bacterial infections, as well as fate and number of hepatic stellate cells and the composition of the extracellular matrix in the liver. Additionally, mechanical forces and damaging stresses towards the sophisticated vessel system of the liver, including the especially equipped sinusoidal endothelium and the biliary tract, work together to mediate hepatocytic import and export of nutritional and toxic substances, adapting to chronic liver disease by morphological and functional changes. All the aforementioned parameters contribute to the outcome of alcohol use disorder and the risk to develop advanced disease stages including cirrhosis, severe alcoholic hepatitis and liver cancer. In the present collection, we summarize current knowledge on these alcohol-related liver disease parameters, excluding the aspect of inflammation, which is presented in the accompanying review article by Lotersztajn and colleagues.
Synthesis and Applications of Asymmetric Catalysis Using Chiral Ligands Containing Quinoline Motifs
Authors: Dhayalan Vasudevan , Dandela Rambabu , Devi K. Bavya , Dhanusuraman Ragupathy
Published: January 2022

In the past decade, asymmetric synthesis of chiral ligands containing quinoline motifs, a family of natural products displaying a broad range of structural diversity and their metal complexes, have become the most significant methodology for the generation of enantiomerically pure compounds of biological and pharmaceutical interest. This review provides comprehensive insight on the plethora of nitrogen-based chiral ligands containing quinoline motifs and organocatalysts used in asymmetric synthesis. However, it is confined to the synthesis of quinoline-based chiral ligands and metal complexes, and their applications in asymmetric synthesis as homogeneous and heterogeneous catalysts.

1 Introduction

2 Synthesis of Chiral Ligands Containing Quinoline Motifs

2.1 Synthesis of Schiff Base Type Chiral Ligands

2.2 Synthesis of Oxazolinyl-Type Chiral Ligands

2.3 Synthesis of Chiral N,N-Type Ligands

2.4 Synthesis of Amine-Based Chiral Ligands

2.5 Synthesis of P,N-Type Chiral Ligands

2.6 Synthesis of Chiral N-Oxide and Nitrogen Ligands

3 Homogeneous Catalytic Asymmetric Reactions

3.1 Asymmetric Carbon–Carbon Bond Formation Reactions

3.2 Asymmetric Allylic Reactions

3.3 Asymmetric Cycloadditions

3.4 Asymmetric Carbene Insertions

3.5 Asymmetric Pinacol Couplings

3.6 Asymmetric Pudovik Reactions

3.7 Asymmetric Strecker Reactions

4 Heterogeneous Catalytic Asymmetric Reactions

4.1 Asymmetric Cyclopropanation of Olefins

4.2 Asymmetric Heck Reactions

4.3 Asymmetric Hydrogenations

4.4 Asymmetric Hydroformylation of Styrene

4.5 Asymmetric Dialkoxylation of 2-Propenylphenols

4.6 Asymmetric Cascade Cyclizations

4.7 Asymmetric Allylic Alkylations

4.8 Asymmetric Alkylation of β-Keto Esters

4.9 Asymmetric C–H Bond Arylation Reactions

4.10 Intramolecular Aerobic Oxidative Amination of Alkenes

4.11 Asymmetric Oxidative Hydroboration of Alkenes

5 Conclusions
p-Quinol Ethers and p-Quinone Monoacetals as Arylation and Oxidation Reagents: Tandem N-Arylation and α-Functionalization of Pyrrolidine via Redox-Neutral Three-Component Reaction
Authors: Shen Ruwei , Li Xiaojie , Xie Yuxin , Yin Kaixin , Zhu Dunru
Published: January 2022

The value of functional pyrrolidines in the fields of biology, pharmacology, catalysis, and natural product synthesis stimulates an intensive interest in developing new synthetic methods for this class of compounds, and direct functionalization of the simple pyrrolidine represents an attractive and effective approach. Herein, a metal-free protocol for direct N-arylation and α-functionalization of pyrrolidine via redox-neutral three-component reactions is reported, in which p-quinol ethers or p-quinone monoacetals serve as the arylation components and the formal oxidants for α-functionalization of pyrrolidine.
Synthesis of 2-Arylbenzothiazoles from Nitrobenzenes, Benzylamines, and Elemental Sulfur via Redox Cyclization
Authors: Teramoto Masahiro , Mizuno Takumi , Imoto Mitsutaka , Takeda Motonori , Nomoto Akihiro , Ogawa Akiya
Published: January 2022

A sustainable advanced synthetic method was developed based on redox cyclization for the synthesis of 2-arylbenzothiazoles in good to excellent yields from readily available nitrobenzenes, benzylamines, and elemental sulfur without the use of transition-metal catalysts. This method is remarkable: nitro group reduction, a benzylamine redox reaction, sulfuration, condensation, and cyclization, all proceed in a single step to generate a heterocycle. It is also highly atom-economical and does not require any external oxidizing or reducing agents.
Synthesis of Aryl Nitriles via Aerobic Oxidative Cleavage of Aryl C=C Bonds with (NH4)2CO3 as the Nitrogen Source
Authors: Zheng Yi , Liu Wenbo , Ren Yun-Lai , Tian Xinzhe
Published: January 2022

An aerobic oxidative method was developed for conversion of arylethenes to aromatic nitriles using (NH4)2CO3 as the nitrogen source and Cu(NO3)2 as the catalyst. The present method allowed a series of arylethenes to underwent oxidative cleavage of C=C bonds to give the targeted products in low to high yields. In addition, the present conditions are compatible with many groups such as alkyl, alkoxy, N,N-dimethylamino, chloro, bromo, iodo, ester, cyano group, and so on.
Surgical Outcome of Spinal Subdural Abscesses: A Report of Four Consecutive Patients and Brief Review of the Literature
Authors: Abdallah Anas , Emel Erhan , Abdallah Betül Güler , Öztürk Delal , Çınar İrfan , Avyasov Rashid
Published: January 2022

Background and Study Aims Spinal subdural abscesses (SSAs) are rare and have a poor prognosis, especially when they are diagnosed late. In the literature, most cases of SSAs have been reported as case reports and small case series. In this study, we aimed to evaluate the surgical outcomes of four consecutive SSA patients.

Material and Methods In this retrospective study, we reviewed the medical charts of four SSA patients who underwent surgical intervention at two neurosurgical centers from September 2012 to September 2019.

Results Our series comprised four patients (three females and one male) with SSA (intradural–extramedullary) who were treated surgically. Holocord SSA was observed in two patients. The mean age was 15.1 ± 17.1 years. Unsteady gait and weakness of legs was the presenting symptom in all patients. The mean preoperative course was 5.3 ± 3.4 weeks. The causative pathogens were methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, and Mycobacterium tuberculosis. In the fourth case, the pathogen was non–M. tuberculosis. In the 44th postoperative month, the patient underwent surgery for an intramedullary abscess. The causative pathogen was E. coli. Except for one adolescent male who was paraplegic at presentation, improvement was observed in all patients at their last follow-up after 54.0 ± 35.9 months after surgery.

Conclusion Early diagnosis and urgent surgical intervention are essential for a good prognosis in SSA cases. We recommend drainage followed by appropriate antibiotics.
A Novel Technique of Intradiverticular Papillary Canulation Aided by EVL Band Ligator in a Case of Lemmel's Syndrome
Authors: Subramanyam Shanmuganathan , Bachkaniwala Vatsal , Vikranth Chunduri V.V. , Ganesh P
Published: January 2022

A duodenal periampullary diverticulum can cause changes in the local anatomy and pose a challenge for the cannulation of the bile duct. Cannulation may be much more difficult if the ampulla is located within the diverticula. We present the case of a 40-year-old man who developed obstructive jaundice and cholangitis because of the duodenal diverticula mechanically obstructing the common bile duct (Lemmel's syndrome). The papilla was located entirely within the duodenal diverticula and was brought out after placing endoscopic variceal ligation (EVL) bands. Biliary access and stenting could be done easily, after exposing the papilla. There were no complications during the procedure or the recovery period.
Dexmedetomidine Can Reduce the Level of Oxidative Stress and Serum miR-10a in Patients with Lung Cancer after Surgery
Authors: Zhou Yan , Dong Xia , Zhang Lei
Published: January 2022

Objective Lung cancer is a primary cause of cancer death. This study assessed the action of dexmedetomidine (DEX) on oxidative stress (OS) and microRNA 10a (miR-10a) in patients with lung cancer.

Methods Patients were given 1 µg/kg DEX before anesthesia and control patients were given saline. The duration of intraoperative one-lung ventilation (OLV) and fluid intake were determined, and mean arterial pressure, heart rate and bispectral index were observed at the time of before anesthesia (T0), immediately after endotracheal intubation (T1), 1 hour after OLV (T2), and 10 minutes before the end of surgery (T3). The expressions and correlations of miR-10a, inflammation and OS levels in the serum were analyzed. The effects of DEX intervention and miR-10a level on pulmonary complications were analyzed.

Results Patients with DEX intervention had lower levels of inflammation and OS during perioperative period than the controls. DEX intervention reduced miR-10a levels in patients during perioperative period. miR-10a in serum of patients with DEX intervention after surgery was positively-correlated with the concentrations of malondialdehyde, and inflammatory factors, while negatively-correlated with superoxide dismutase. The total incidence of postoperative pulmonary complications after DEX intervention was lowered. Patients with high miR-10a expression had a higher cumulative incidence of pulmonary complications than those with low miR-10a expression.

Conclusion DEX can reduce postoperative OS and plasma miR-10a level in patients with lung cancer, and high expression of miR-10a predicts a high incidence of postoperative pulmonary complications.
Risk Factors for High Blood Product Use in Patients with Stanford Type A Dissection
Authors: Schafigh Myriam , Welz Armin , Hamiko Marwan , Kohistani Zaki , Treede Hendrik , Probst Chris
Published: January 2022

Background Intraoperative and postoperative bleeding associated with allogeneic blood transfusion and reoperation is still a common and feared complication in patients undergoing surgery due to acute Type A Aortic Dissection (aTAAD). The aim of our study was to identify risk factors for higher transfusion rates.

Methods In this retrospective single center study we evaluated pre -, intra-, and postoperative data of 121 patients with aTAAD. Depending on the median of received packed red blood cells (PRBCs), patients were divided into Group A (<8 PRBC, n = 53) and Group B (≥8 PRBC n = 68). Statistical analyses (descriptive statistics, univariable and multivariable logistic regression) were performed using SPSS software 25.0. Statistical significance was assumed at p-value <0.05.

Results A total of 120 patients received a blood product during their perioperative course. Among others we identified age, hemorrhagic pericardial effusion, and dual antiplatelet therapy as preoperative risk factors, low rectal temperature as intraoperative risk factor and low body temperature, positive fluid balance, high lactate level and beginning development of acute renal failure as postoperative risk factors.

Conclusion Our study identifies several factors which predict a higher likelihood of bleeding and consecutive blood transfusion. Knowledge of these factors could influence the therapy to reduce transfusion requirements and lead to a targeted and more efficient use of coagulation products.
Breaking the Barrier in Endoscopy
Authors: Pal Partha , Ramchandani Mohan , Pradev Inavolu , Singh Aniruddha Pratap , Reddy Duvvuru Nageshwar
Published: January 2022

In this narrative review, invited by the Editors of the Journal of Digestive Endoscopy, we summarize recent advances in the field of gastrointestinal endoscopy with regard to reaching the earlier inaccessible areas in the gut by newer methods and technology. This article primarily discusses recent advances in the past few years in the following headings: (1) reaching redundant small bowel via enteroscopy (primarily motorized spiral enteroscopy), (2) reaching the thin pancreaticobiliary ducts via cholangioscopy and pancreatoscopy, (3) going out of the gut wall: third-space endoscopy (primarily peroral endoscopic myotomy: POEM). A thorough literature review was performed on each topic describing how the advances were evolving.
Salivary Antioxidant Capacity and Oral Health Status in Children with Visual Impairments—A Cross-Sectional Study
Authors: Hazra Madhurima , Shetty Vabitha , Suresh Lekshmi Radhakrishnan
Published: January 2022

Background Children with visual impairment are at a higher risk for developing dental disease, and imbalances in the antioxidant levels may play an important role in the development and management of oral diseases.

Aim Our aim was to evaluate and compare the oral health status and salivary total antioxidant capacity (TAC) in children with and without visual impairment.

Methods Oral health was evaluated among 6 to 11 years old children with and without visual impairment (50 each) using World Health Organization oral health assessment form for caries prevalence, gingival health, and oral hygiene levels. Unstimulated saliva was collected and assayed for TAC using the phosphomolybdic method.

Statistical Analysis The data collected were tabulated, and the results, thus, obtained were subjected to statistical analysis using EZR software—version 1.37. The variables between the two groups were compared using the Mann–Whitney U test and Fisher's exact test. A correlation test was done using Spearman's correlation test.

Results The mean TAC levels among children with and without visual impairment were 49.17 (±25.702) and 156.67 (±56.031) µg/mL, respectively, which was statistically significant (p < 0.001). The children with visual impairment showed a significantly higher number of carious lesions compared with the control group (p < 0.001). Oral hygiene status and gingival health status were significantly poorer in children with visual impairments than the children in the control group (p < 0.001).

Conclusions Oral health was significantly poorer, and salivary TAC levels were significantly lower in children with visual impairment. There may be an inverse correlation between salivary TAC and oral health status. Clinical Significance: Since these children have been shown to have poorer oral health status, a baseline assessment of their salivary antioxidant capacity may indicate the need to reinforce oral care efforts and supplement them using an antioxidant-rich diet.
Challenges at Technology Adoption in Academic Learning among Students during the COVID-19 Lockdown
Authors: Rodrigues Devina E. , Kamath Neetha , Souza Renita Priya D.
Published: January 2022

Introduction Traditional classrooms with limited flexibility in cell phones and social platforms like Twitter and Facebook are typical for most schools and colleges. The coronavirus disease 2019 lockdown scenario opened up a new way and created a wave in purchasing and using android phones, laptops, high-intensity Wi-Fi, which gave an entirely new look to the educational system. Hence, the present study aims to assess the challenges at technology adaption in academic learning faced by nursing students.

Methodology A quantitative cross-sectional descriptive survey design was adopted. A total of 708 nursing students were selected using the universal sampling technique in the study. Prior to the study obtained ethical clearance certificate and authority permission from the institutes where the participants were pursuing their nursing course. Demographic Proforma and challenges of technology adoption rating scale were prepared and sent to nursing students online to determine the challenges of technology adoption for academic learning. A second reminder was sent if the participants failed to submit the online forms within 2 days.

Results The majority of the students, 557 (78.6%), were between the age group of 18 to 21 years, 658 (92.9%) were females, and 688 (97.2%) of them were pursuing a BSc nursing course. The majority, 188 (26.6%), of the students were pursuing second year BSc. One-third (257; 36.3%) of the participants were from Karnataka. Most of the students, (677; 95.6%), felt that virtual classes have barriers to learning opportunities. A small proportion of the students felt that technology adoption is an opportunity to learn academics during the lockdown. Mean percentage scores of (394; 55.59%) subjects indicate virtual classes made them face many challenges in the form of barriers to learning academics.

Conclusion Adequate training on handling technical issues and advanced technology is the need of the hour in higher education institutions. Online teaching and learning should be made an integral part of teaching-learning methodologies to keep the students abreast of advancing technologies.
Algebraic and geometric structures inside the Birkhoff polytope
Authors: Rajchel-Mieldzioć Grzegorz , Korzekwa Kamil , Puchała Zbigniew , Życzkowski Karol
Published: January 2022

The Birkhoff polytope Bd consisting of all bistochastic matrices of order d assists researchers from many areas, including combinatorics, statistical physics, and quantum information. Its subset Ud of unistochastic matrices, determined by squared moduli of unitary matrices, is of particular importance for quantum theory as classical dynamical systems described by unistochastic transition matrices can be quantized. In order to investigate the problem of unistochasticity, we introduce the set Ld of bracelet matrices that forms a subset of Bd, but a superset of Ud. We prove that for every dimension d, this set contains the set of factorizable bistochastic matrices Fd and is closed under matrix multiplication by elements of Fd. Moreover, we prove that both Ld and Fd are star-shaped with respect to the flat matrix. We also analyze the set of d × d unistochastic matrices arising from circulant unitary matrices and show that their spectra lie inside d-hypocycloids on the complex plane. Finally, applying our results to small dimensions, we fully characterize the set of circulant unistochastic matrices of order d ≤ 4 and prove that such matrices form a monoid for d = 3.
Integrable classes of a family of evolution equations
Authors: Ndogmo J. C.
Published: January 2022

The problem of classification into symmetry integrable classes is solved for a family of second order nonlinear evolution equations labeled by arbitrary functions. Four nonequivalent symmetry integrable classes are thus obtained, and the results are transformed into known integrable equations from the literature. Recursion operators are also given for all the symmetry integrable classes found, some of which are the only ones known for some of the canonical classes.
Surface phonon polaritons for infrared optoelectronics
Authors: Gubbin Christopher R. , De Liberato Simone , Folland Thomas G.
Published: January 2022

In recent years, there has been significant fundamental research into surface phonon polaritons, owing to their ability to compress light to extremely small dimensions, low losses, and the ability to support anisotropic propagation. In this Perspective, after briefly reviewing the present state of mid-infrared optoelectronics, we will assess the potential of surface phonon polariton-based nanophotonics for infrared (3–100 μm) light sources, detectors, and modulators. These will operate in the Reststrahlen region where conventional semiconductor light sources become ineffective. Drawing on the results from the past few years, we will sketch some promising paths to create such devices and we will evaluate their practical advantages and disadvantages when compared to other approaches to infrared optoelectronics.
Qualitative evidence of the flexoelectric effect in a single multi-wall carbon nanotube by nanorobotic manipulation
Authors: El Beainou R. , Rauch J.-Y. , Dembélé S. , Lehmann O. , Hirsinger L. , Devel M.
Published: January 2022

The flexoelectric effect corresponds to the linear variation of the electric polarization of a material subjected to a strain gradient (i.e., during its mechanical bending). Unlike piezoelectricity, it also exists in non-centrosymmetric materials. Furthermore, due to the gradient term, its magnitude can increase as the size of the system decreases. Thanks to this effect, nanoscale systems could be used to harvest thermal vibration energy to power a microdevice. These could be multi-wall carbon nanotubes since they are known to bend easily in an elastic manner. However, it is very challenging to experimentally measure the flexoelectric behavior of a single multi-wall carbon nanotube due to its small size (less than 50 nm in diameter), to the low level of induced charges, and to the need to vary the imposed stress. To progress in this direction, a six-degree-of-freedom robot with a fiber tip is used inside a dual-beam microscope to pick up few single carbon nanotubes from a tangle and connect them to the fiber tip. After ion-soldering the two tips, each carbon nanotube is dynamically bent several times while monitoring the brightness of the bending area and its effective radius of curvature. This allowed us to demonstrate qualitatively the flexoelectric effect at the level of a single multi-wall carbon nanotube.
Equivalence between exponential stabilization and boundary observability for swelling problem
Authors: Ramos A. J. A. , Apalara T. A. , Freitas M. M. , Araújo M. L.
Published: January 2022

The present work investigates the equivalence result between the exponential stabilization of swelling porous elastic media and its exact boundary observability. The well-posedness result is also established.
Recovery of aluminum–zinc alloy from 55%Al–Zn dross by supergravity separation
Authors: Wang Lu , Wang Zhe , Zhang Shuai , Wei Kuixian , Guo Zhancheng
Published: January 2022

As a by-product of hot-dip 55%Al–Zn coating processing, the dross contains high levels of Al and Zn. However, no cost-effective recycling methods have been reported to date. Therefore, this work aims at developing a novel method for Al–Zn alloy recovery from an industrial 55%Al–Zn dross using supergravity separation. The separation efficiency was analyzed as a function of separation time and temperature as well as the gravity coefficient (G). Al–Zn alloy was recovered at G values above 70. Separation at higher temperatures benefited the recovery of Al–Zn alloy but decreased the removal rate of Fe impurities due to the increased Fe solubility. With the optimal conditions at 590 °C and G > 500, over 86 wt. % of Al–Zn alloy, containing only 0.4 wt. % of Fe, was recovered. According to the FactSage software calculation, the solubility of Fe increases from 0.06 to 1.11 wt. % when the temperature rises from 550 to 650 °C. This is consistent with the experimental results. The purified alloy could then be further used in the hot-dip 55%Al–Zn bath for production. This study demonstrates the feasibility of supergravity separation as a promising process efficient for recovering Al–Zn alloy from 55%Al–Zn dross.
Enhancement of anomalous Hall effect in epitaxial thin films of intrinsic magnetic topological insulator MnBi2Te4 with Fermi-level tuning
Authors: Watanabe Ryota , Yoshimi Ryutaro , Kawamura Minoru , Kaneko Yoshio , Takahashi Kei S. , Tsukazaki Atsushi , Kawasaki Masashi , Tokura Yoshinori
Published: January 2022

The recently discovered intrinsic magnetic topological insulator MnBi2Te4 has attracted keen interest for exotic quantum states such as a quantum anomalous Hall insulator and an axion insulator. Such quantum states of MnBi2Te4 have been intensively studied mainly in atomically thin exfoliated samples, yet thin film samples with critically tuned Fermi level would be indispensable for further pursuit of topological functionality in MnBi2Te4 and related heterointerfaces. Here, we report on fabrication of an Sb-doped MnBi2Te4 thin film by molecular beam epitaxy and their transport properties. The Sb-substitution induces the change in the carrier type and the subsequent increase in resistivity, demonstrating the tuning of the Fermi level (EF) across the bulk bandgap and the phase change to the topologically nontrivial phase. The EF is further finely controlled in a field-effect transistor device. We observe the enhancement of the anomalous Hall conductivity at the charge neutral point, confirming the opening of the magnetic exchange gap in surface Dirac states. The precise control of the band structure and the Fermi level in the thin-film form will lead to exploring exotic phenomena based on intrinsic magnetic topological insulators.
Effects of Fermi pinning and quantum mechanisms on leakage current of 4H-SiC Schottky diodes
Authors: Baum I. , Darmody C. , Cui Y. , Goldsman N.
Published: January 2022

Reverse bias leakage current through 4H-SiC Schottky diodes was modeled using quantum transmission theory and the theoretically calculated values were compared with the measured values from fabricated Schottky diodes. To account for interface defects, energy barriers due to Fermi pinning from previously observed defects were used in place of the ideal barrier structure predicted by the Schottky–Mott rule. Incorporating barriers with energy values set due to Fermi pinning at known defect energies resulted in better experimental agreement by many orders of magnitude.
Voltage-programmable negative differential resistance in memristor of single-crystalline lithium niobate thin film
Authors: Wang Jiejun , Pan Xinqiang , Luo Wenbo , Shuai Yao , Zeng Huizhong , Xie Qin , Huang Shitian , Wu Chuangui , Zhang Wanli
Published: January 2022

Negative differential resistance (NDR) in memristor has attracted considerable attention due to its nonlinear dynamic characteristic accompanied by resistive switching behavior. Here, we demonstrated the voltage-programmable NDR effect in an Au/LNO/Pt memristor based on a single-crystalline lithium niobate (SC-LNO) thin film tuned by low-energy Ar+ irradiation. A typical N-Shape NDR behavior occurs in reverse bias and can be programmed by changing the positive sweeping voltage. Moreover, thickness-dependent of the NDR behavior was also investigated. Thanks to the merit of the SC-LNO thin film, our memristor reveals excellent uniformity and reproducibility with low cycle-to-cycle variation (down to 1.82% for Ipeak and 2.94% for Vvalley). The carrier transport mechanism of our device is attributed to the interplay of trap-controlled space-charge-limited conduction (SCLC) and the Fowler–Nordheim (FN) tunneling. The transition from bulk-limited conduction (SCLC) to interfacial one (FN) tuned by Ar+ irradiation is crucial for our NDR devices.
Microwave absorption in epoxy composites filled with MoS2 and carbon nanotubes
Authors: Vovchenko Ludmila , Matzui Ludmila , Yakovenko Olena , Oliynyk Viktor , Len Tetyana , Naumenko Antonina , Kulikov Leonid
Published: January 2022

In this study, the microwave absorbing properties of epoxy composites filled with micro-sized MoS2 and carbon nanotubes (CNT)/MoS2 were investigated in the frequency range of 1–67 GHz. Sample characterization was performed using electron microscopy and Raman spectroscopy methods. Direct current (DC) conductivity, complex permittivity, and shielding properties of composite materials with 50 wt. % of MoS2 and 1.5–2 wt. %CNT/50 wt.%MoS2 were measured. The permittivity of 50 wt. % MoS2/epoxy composite was found to be equal to 7.3, decreasing monotonically down to 4.5 at 67 GHz, while the imaginary part is equal to 1 and does not change. The addition of 2 wt. % of CNTs increases the real part of permittivity εr′ up to 30 at 1 GHz (13 at 67 GHz) and also leads to a large increase of the imaginary part of permittivity, with the most pronounced relaxation peak εr′′=10 at 10 GHz. Such an increase of dielectric loss correlates with the increase of DC conductivity up to 3.2 × 10−5 S/m as compared to the two-phase composite 50 wt. %MoS2/epoxy (σdc = 1.7 × 10−9 S/m). It was shown that 50 wt. %MoS2/epoxy composite exhibited an effective microwave absorption bandwidth of 9.9 GHz at the sample thickness of 2.0 mm with reflection loss minimum of -20.0 dB at 51.5 GHz. 2 wt. %CNT/50 wt. %MoS2/epoxy composite with a thickness of 0.9 mm showed a reflection loss minimum of −38 dB at 20.2 GHz with the absorption bandwidth of 3.68 GHz. The influence of sample thickness on position, width, and depth of EMR absorption maximums for the composites filled with MoS2 and mixed filler CNT/MoS2 was also determined.
Machine learning-assisted low-frequency and broadband sound absorber with coherently coupled weak resonances
Authors: Chen An , Xu Zi-Xiang , Zheng Bin , Yang Jing , Liang Bin , Cheng Jian-Chun
Published: January 2022

An artificial broadband sound absorber composed of multiple components is of significant interest in the physics and engineering communities. The existence of coherently coupled weak resonances (CCWRs) makes it difficult to achieve optimal broadband sound absorption, especially in the presence of complex and aperiodic components. Here, we present and experimentally implement a machine learning-assisted subwavelength sound absorber with CCWRs using an improved Gauss–Bayesian model, which exhibits flexible, high-efficient, and broadband properties at low frequencies (<500 Hz). The proposed aperiodic structure comprises three parallel split-ring units, which enable a quasi-symmetric resonant mode to be generated and effectively dissipate energy because of the huge phase difference between each component at the coupled resonant frequency. With high algorithmic efficiency (no more than 80 iterations), the improved Gauss–Bayesian model inversely determines the optimal CCWRs, realizing a reconfigurable high sound absorption spectrum (α > 0.9) from 229 to 457 Hz. The optimal configuration of sound spectrum characteristics and the unit cell structure can be confirmed flexibly. Good agreement between numerical and experimental results verifies the effectiveness of the proposed method. To further exhibit broadband and multiparameter optimization, a nine-unit sound absorber (27 parameters) is numerically simulated and shown to achieve high acoustic absorption and a relatively broad bandwidth (44.8%). Our work lifts the restrictions on analytic models of complex and aperiodic components with coherent coupling effects, paving the way for combining machine learning with the optimal design of metamaterials.
On nonlinearity in field-effect transistor-based binding assay response
Authors: Gao Wuran , Chui Chi On
Published: January 2022

Field-effect transistor (FET)-based biosensors have demonstrated highly sensitive label-free detection of a plethora of biomolecules as next-generation binding assays. While the dose–response curve of affinity-based binding assays generally has a nonlinear shape, any distortion contributed by the FET transducers has not been well understood. In this paper, we show that the signal transduction of FET sensors plays an important role in shaping their dose–response curves when operating in the nonlinear screening regime. We have found that the nonlinearity arising from the counterion screening in the electrical double layer could distort the relationship between the device flatband voltage shift and the analyte concentrations in (1) lowering its half-maximal response concentration as well as the sensitive detection range and (2) expanding its dynamic range. Negligence of such nonlinearity would introduce errors in the extracted affinity properties of the analyte–receptor pair. This work provides useful guidelines for designing FET-based binding assays and interpreting their measurement data.
Dual-configuration in-memory computing bitcells using SiOx RRAM for binary neural networks
Authors: Kingra Sandeep Kaur , Parmar Vivek , Negi Shubham , Bricalli Alessandro , Piccolboni Giuseppe , Regev Amir , Nodin Jean-François , Molas Gabriel , Suri Manan
Published: January 2022

Conventional DNN (deep neural network) implementations rely on networks with sizes in the order of MBs (megabytes) and computation complexity of the order of Tera FLOPs (floating point operations per second). However, implementing such networks in the context of edge-AI (artificial intelligence) poses limitations due to the requirement of high precision computation blocks, large memory requirement, and memory wall. To address this, low-precision DNN implementations based on IMC (in-memory computing) approaches utilizing NVM (non-volatile memory) devices have been explored recently. In this work, we experimentally demonstrate a dual-configuration XNOR (exclusive NOR) IMC bitcell. The bitcell is realized using fabricated 1T-1R SiOx RRAM (resistive random access memory) arrays. We have analyzed the trade-off in terms of circuit-overhead, energy, and latency for both IMC bitcell configurations. Furthermore, we demonstrate the functionality of the proposed IMC bitcells with mobilenet architecture based BNNs (binarized neural networks). The network is trained on VWW (visual wake words) and CIFAR-10 datasets, leading to an inference accuracy of ≈80.3% and ≈84.9%, respectively. Additionally, the impact of simulated BER (bit error rate) on the BNN accuracy is also analyzed.