bluuebunny/crossref_metadata_2025 huggingface dataset:
Recurrence-Free Survival in Early and Locally Advanced Large Cell Neuroendocrine Carcinoma of the Lung after Complete Tumor Resection
Authors: Altieri Barbara , La Salvia Anna , Modica Roberta , Marciello Francesca , Mercier Olaf , Filosso Pier Luigi , de Latour Bertrand Richard , Giuffrida Dario , Campione Severo , Guggino Gianluca , Fadel Elie , Papotti Mauro , Colao Annamaria , Scoazec Jean-Yves , Baudin Eric , Faggiano Antongiulio
Published: February 2023

Background: Large Cell Neuroendocrine Carcinoma (LCNEC) is a rare subtype of lung cancer with poor clinical outcomes. Data on recurrence-free survival (RFS) in early and locally advanced pure LCNEC after complete resection (R0) are lacking. This study aims to evaluate clinical outcomes in this subgroup of patients and to identify potential prognostic markers. Methods: Retrospective multicenter study including patients with pure LCNEC stage I-III and R0 resection. Clinicopathological characteristics, RFS, and disease-specific survival (DSS) were evaluated. Univariate and multivariate analyses were performed. Results: 39 patients (M:F = 26:13), with a median age of 64 years (44–83), were included. Lobectomy (69.2%), bilobectomy (5.1%), pneumonectomy (18%), and wedge resection (7.7%) were performed mostly associated with lymphadenectomy. Adjuvant therapy included platinum-based chemotherapy and/or radiotherapy in 58.9% of cases. After a median follow-up of 44 (4–169) months, the median RFS was 39 months with 1-, 2- and 5-year RFS rates of 60.0%, 54.6%, and 44.9%, respectively. Median DSS was 72 months with a 1-, 2- and 5-year rate of 86.8, 75.9, and 57.4%, respectively. At multivariate analysis, age (cut-off 65 years old) and pN status were independent prognostic factors for both RFS (HR = 4.19, 95%CI = 1.46–12.07, p = 0.008 and HR = 13.56, 95%CI 2.45–74.89, p = 0.003, respectively) and DSS (HR = 9.30, 95%CI 2.23–38.83, p = 0.002 and HR = 11.88, 95%CI 2.28–61.84, p = 0.003, respectively). Conclusion: After R0 resection of LCNEC, half of the patients recurred mostly within the first two years of follow-up. Age and lymph node metastasis could help to stratify patients for adjuvant therapy.
An Overview of Specific Considerations in Chronic Venous Disease and Iliofemoral Venous Stenting
Authors: Saleem Taimur
Published: February 2023

Unlike arterial disease, chronic venous disease (CVD) is rarely life-threatening or limb-threatening. However, it can impose substantial morbidity on patients by influencing their lifestyle and quality of life (QoL). The aim of this nonsystematic narrative review is to provide an overview of the most recent information on the management of CVD and specifically, iliofemoral venous stenting in the context of personalized considerations for specific patient populations. The philosophy of treating CVD and phases of endovenous iliac stenting are also described in this review. Additionally, the use of intravascular ultrasound is described as the preferred operative diagnostic procedural tool for iliofemoral venous stent placement.
Spironolactone as a Potential New Treatment to Prevent Arrhythmias in Arrhythmogenic Cardiomyopathy Cell Model
Authors: Reisqs Jean-Baptiste , Moreau Adrien , Sleiman Yvonne , Charrabi Azzouz , Delinière Antoine , Bessière Francis , Gardey Kevin , Richard Sylvain , Chevalier Philippe
Published: February 2023

Arrhythmogenic cardiomyopathy (ACM) is a rare genetic disease associated with ventricular arrhythmias in patients. The occurrence of these arrhythmias is due to direct electrophysiological remodeling of the cardiomyocytes, namely a reduction in the action potential duration (APD) and a disturbance of Ca2+ homeostasis. Interestingly, spironolactone (SP), a mineralocorticoid receptor antagonist, is known to block K+ channels and may reduce arrhythmias. Here, we assess the direct effect of SP and its metabolite canrenoic acid (CA) in cardiomyocytes derived from human-induced pluripotent stem cells (hiPSC-CMs) of a patient bearing a missense mutation (c.394C>T) in the DSC2 gene coding for desmocollin 2 and for the amino acid replacement of arginine by cysteine at position 132 (R132C). SP and CA corrected the APD in the muted cells (vs. the control) in linking to a normalization of the hERG and KCNQ1 K+ channel currents. In addition, SP and CA had a direct cellular effect on Ca2+ homeostasis. They reduced the amplitude and aberrant Ca2+ events. In conclusion, we show the direct beneficial effects of SP on the AP and Ca2+ homeostasis of DSC2-specific hiPSC-CMs. These results provide a rationale for a new therapeutical approach to tackle mechanical and electrical burdens in patients suffering from ACM.
Institutional Investors’ Distraction and Executive Compensation Stickiness Based on Multiple Regression Analysis
Authors: Hong Yizhao , Cao Chongyan
Published: February 2023

Based on the impact of industry extreme return on the attention of institutional investors, taking Chinese A-share listed companies from 2011 to 2020 as a sample, this paper empirically tests the relationship between institutional investors’ distraction and executive compensation stickiness based on multiple regression analysis. The study finds that institutional investors’ distraction promotes the executive compensation stickiness, which is more significant in the group of pressure-resistant institutional investors. The mechanism test finds that based on the governance effect, information effect and psychological effect, corporate external governance, stock price information content and management anxiety play a partial intermediary role between institutional investors’ distraction and executive compensation stickiness. The moderating effect finds that the level of corporate internal governance and managerial overconfidence will weaken the impact of institutional investors’ distraction on executive compensation stickiness. In addition, the distraction behavior in non-state-owned and western companies has a more significant economic impact.
Assessment of Project Management Maturity Models Strengths and Weaknesses
Authors: Nikolaenko Valentin , Sidorov Anatoly
Published: February 2023

The purpose of this article is to analyze the most popular maturity models in order to identify their strengths and weaknesses. Research conducted by international project management communities such as Software Engineering Institute (SEI), Project Management Institute (PMI), International Project Management Association (IPMA), Office of Government Commerce (OGC) and International Organization for Standardization (ISO) showed that organizations with high managerial maturity are more likely to achieve their planned project goals than those that do not identify and standardize their best management practices. This circumstance has encouraged scientists from all over the world to start developing various models that can measure and evaluate managerial maturity in projects. Nowadays, the variety of models created has led to considerable difficulty in understanding the strengths and weaknesses of each model. To solve this problem, the article authors conducted a critical analysis to identify the strengths and weaknesses of the most popular project management maturity models. The results obtained will be of interest to project managers, members of project teams, heads of organizations, project offices and everyone involved in the development of project activities. Based on the analysis, it was found that the most developed maturity models are based on international codes of knowledge of project management. Most maturity models ignore the presence of structural and infrastructural elements, such as a workplace, the necessary equipment and software, the availability of professional standards, instructions, regulations, etc. It was also revealed that there are no processes for assessing the effectiveness and efficiency of using the best practices in the maturity models.
Retirement Income Sufficiency: A Comparison Study in Australia and New Zealand
Authors: Xu Xiaobo , Young Martin , Zou Liping , Fang Jiali
Published: February 2023

We use the 2018 survey data from the Household, Income, and Labour Dynamic (HILDA) in Australia and the Household Economic Survey (HES) in New Zealand to investigate the retirement income sufficiency in Australia and New Zealand. Our baseline results indicate that the annuitized net wealth is greater for Australian retirees than for New Zealand retirees. However, New Zealand retirees enjoy a higher level of life satisfaction than Australian retirees. Further analysis reveals a significant greater pre- and postretirement income for the top 10% of wealthy Australian retirees, mainly due to the higher level of homeownership in Australia within this group. Our study fills the gap in the existing literature, which studies the macro- and microlevel influences on Australia and New Zealand retirees, and it also offers important policy implications.
WEF Nexus Policy Review of Four Mediterranean Countries
Authors: Bazzana Davide , Comincioli Nicola , El Khoury Cristina , Nardi Fernando , Vergalli Sergio
Published: February 2023

The Water–Energy–Food (WEF) nexus describes natural resource use in the context of social needs and economic development, addressing food, water, and energy security. Population growth and rising economic prosperity will increase the demand for energy, food, and water in the Mediterranean region, compromising the sustainable use of resources. As governments are required to make decisions in order to cope with increasing demands for resources, this paper performs a review of the legislation and WEF policies, identifying the main political and institutional actors involved and the possible policy (in)coherence in four MED countries located on two continents: Egypt, Italy, Spain, and Tunisia. This choice will allow the identification of the barriers and catalysts influencing the implementation of WEF policies and will improve our understanding of the WEF trade-offs and synergies by exploring them on national, regional, and local scales.
Decision Making and Influencing Factors in Withdrawal of Rural Residential Land-Use Rights in Suzhou, Anhui Province, China
Authors: Wang Xianjun , Kang Junfang
Published: February 2023

The withdrawal of rural residential land-use rights is a major initiative in China’s current rural land reform, and it is of great importance in promoting the rural revitalization and urbanization strategy. The Chinese government encourages farmers to withdraw from their residential bases in an orderly manner to effectively revitalize land resources. The study aimed to explore the key factors that influenced the decision of farmers to withdraw from their rural residential lands in different contexts and proposed suggestions for related policy reforms. Firstly, the study proposed hypotheses based on the theories of the hierarchy of needs and peasant household behavior, combined with the current situation of the research area. Then taking the withdrawal policies and practical experiences of some pilot areas in China as a reference. Secondly, the study set five exit modes for withdrawing the right to use rural residential land and programmed four dimensions of the factors that affected those decisions to form the questionnaire. A total of 533 valid questionnaires were obtained by using scenario simulation. Thirdly, the study analyzed the influential factors of the exit decisions of the different modes using the multivariate ordered logistic regression model and tested the hypotheses using the abovementioned methods. The results showed the following: (1) the willingness of the rural residents to accept the different exit modes for withdrawing their rural residential land-use rights substantially varied. The rural residents prioritized the exit modes that were beneficial to their future housing and other social security. (2) There were some differences in the influencing factors on the exit decisions. Among the four-dimensional factors, the “rural residents’ cognitive characteristics” had a substantial impact on the decisions for withdrawing rural residential land-use rights. Based on the research conclusions, the study proposed some targeted policy suggestions: steadily promoting the construction of a high-quality social security system, promoting classified governance policies based on the diversified needs of farmers and strengthening the individual cognition of relocated farmers to withdraw from homesteads. In addition, a more scientific and reasonable land governance system needs to be established.
The Main Drivers of Wetland Evolution in the Beijing-Tianjin-Hebei Plain
Authors: Li Shuai , Ma Haiyu , Yang Di , Hu Wei , Li Hao
Published: February 2023

Analysis of the driving mechanism of wetland change can help identify the spatial differences in the mechanisms of different elements in order to better scientifically prevent and utilize wetlands. The Beijing-Tianjin-Hebei Plain (BTHP) was selected as the study area, and the dynamic degree model and change intensity index were utilized to examine the spatial and temporal changes of wetlands based on four periods of land use data. After establishing a wetland change evaluation system that included topography, geology, meteorological, and human activities, we utilized a random forest model to study the driving mechanism of wetland change from 1990–2020. Based on the developed zoning map, we then offered specific protection policies. We have four major findings: (1) the wetlands reduced significantly in the BTHP and underwent a change process from decreasing to increasing, and reservoirs and rivers, particularly along the Bohai Rim, were the primary determinants of wetland changes; (2) the impact of topographic factors such as elevation showed a significant gradient effect, the impact of geological factors such as hydrogeological division was low and indirect, the impact of meteorological factors was nonlinear, and the impact of anthropic factors was most significant and showed clear spatial directivity; (3) the urban expansion and agricultural reclamation had significant dominant effects, coupled with the topographical effects of elevation and slope, the geological environmental effects of surface subsidence and hydrogeological division, and the cumulative effects of temperature and precipitation, which resulted in the spatial change of wetlands; and (4) protecting wetland integrity, dynamic monitoring, restricting human activities, and establishing wetland buffer zones should be applied to the general area, natural factors area, anthropic factors area, and significant comprehensive area, respectively.
Toward Holistic Perceptions of “Smart” Growth in Development Paradigms and Policy Agendas
Authors: Lankauskienė Rita , Gedminaitė-Raudonė Živilė
Published: February 2023

The examination of “smart” growth in various economic and societal development areas and contexts has spread around the globe, in both scientific and policy discourse, with a recent focus on transformations concerning “smart” green growth, “smart” regional development, and green transformation, including “smart” villages. However, until recently, much confusion has existed regarding different understandings of “smartness” for different communities in different contexts. The main aims of this research are to emphasize the proliferation of perceptions of the term “smart” in different contexts of growth and development paradigms and policy agendas and to illustrate the theoretical findings with a case study concerning Lithuanian perceptions of “smart” development of rural areas. We applied a combination of qualitative and quantitative research methods in this study. The research results and the suggested policy recommendations propose that, currently, “smartness” is perceived more broadly than as a simple application of the word “smart”; i.e., it involves intelligent digital equipment or mechanisms in a particular setting. In the context of economic and political processes—at all levels, supranational, regional, and local—“smart” growth includes “green” growth, increasingly emphasizing the ambition to create holistic intelligent [eco]systems to provide better services—i.e., “smarter” and “greener” services—to the quality of life for human beings.
Suppression of the HOS1 Gene Affects the Level of ROS Depending on Light and Cold
Authors: Gorpenchenko Tatiana , Veremeichik Galina , Shkryl Yurii , Yugay Yulia , Grigorchuk Valeria , Bulgakov Dmitry , Rusapetova Tatiana , Vereshchagina Yulia , Mironova Anastasiya , Subbotin Evgeniyy , Kulchin Yuriy , Bulgakov Victor
Published: February 2023

The E3 ubiquitin-protein ligase HOS1 is an important integrator of temperature information and developmental processes. HOS1 is a negative regulator of plant cold tolerance, and silencing HOS1 leads to increased cold tolerance. In the present work, we studied ROS levels in hos1Cas9 Arabidopsis thaliana plants, in which the HOS1 gene was silenced by disruption of the open reading frame via CRISPR/Cas9 technology. Confocal imaging of intracellular reactive oxygen species (ROS) showed that the hos1 mutation moderately increased levels of ROS under both low and high light (HL) conditions, but wild-type (WT) and hos1Cas9 plants exhibited similar ROS levels in the dark. Visualization of single cells did not reveal differences in the intracellular distribution of ROS between WT and hos1Cas9 plants. The hos1Cas9 plants contained a high basal level of ascorbic acid, maintained a normal balance between reduced and oxidized glutathione (GSH and GSSG), and generated a strong antioxidant defense response against paraquat under HL conditions. Under cold exposure, the hos1 mutation decreased the ROS level and substantially increased the expression of the ascorbate peroxidase genes Apx1 and Apx2. When plants were pre-exposed to cold and further exposed to HL, the expression of the NADPH oxidase genes RbohD and RbohF was increased in the hos1Cas9 plants but not in WT plants. hos1-mediated changes in the level of ROS are cold-dependent and cold-independent, which implies different levels of regulation. Our data indicate that HOS1 is required to maintain ROS homeostasis not only under cold conditions, but also under conditions of both low and high light intensity. It is likely that HOS1 prevents the overinduction of defense mechanisms to balance growth.
Myositis Autoantibodies in Patients with Suspected Post-Treatment Lyme Disease Syndrome
Authors: Sloupenska Kristyna , Koubkova Barbora , Horak Pavel , Hutyrova Beata , Racansky Mojmir , Mares Jan , Miklusova Martina , Schovanek Jan , Zapletalova Jana , Raska Milan , Krupka Michal
Published: February 2023

Most patients suffering from Lyme disease are effectively treated with antibiotics. In some patients, however, problems persist for a long time despite appropriate therapy. The term post-treatment Lyme disease syndrome (PTLDS) is currently used for this condition in scientific literature. The pathogenesis is still not precisely known, but the involvement of immunopathological mechanisms is assumed. In our study, we analyzed the presence of autoantibodies including myositis-specific (MSA) and myositis-associated autoantibodies (MAA) in patients with laboratory proven history of Lyme disease and with clinical symptoms of PTLDS. A total of 59 patients meeting the criteria for PTLDS were enrolled in this study. The control group consisted of 40 patients undergoing differential diagnosis of neurological disorders without clinical and/or laboratory-proven history of Lyme disease. The presence of autoantibodies was determined by immunoblot methods and positive samples were further tested for serum creatine kinase (CK) and myoglobin levels. The presence of myositis autoantibodies was detected in 18 subjects with suspected PTLDS (30.5%), but only in 5% of control subjects exhibiting no evidence of Lyme disease history. The difference was statistically significant (p = 0.002). The subsequent biochemical analysis of muscle-damage markers in positive subjects found a mild elevation in six MSA/MAA-positive PTLDS patients. The study detected raised MSA/MAA autoantibodies formation in the group of PTLDS patients raising the question about their involvement in the pathogenesis of this syndrome.
Clinicopathological Characteristics and Prognostic Profiles of Breast Carcinoma with Neuroendocrine Features
Authors: Qiu Yue , Dai Yongjing , Zhu Li , Hao Xiaopeng , Zhang Liping , Bao Baoshi , Chen Yuhui , Wang Jiandong
Published: February 2023

Background: Breast carcinoma with neuroendocrine features includes neuroendocrine neoplasm of the breast and invasive breast cancer with neuroendocrine differentiation. This study aimed to investigate the clinicopathological features and prognosis of this disease according to the fifth edition of the World Health Organization classification of breast tumors. Materials and Methods: A total of 87 patients with breast carcinoma with neuroendocrine features treated in the First Medical Center, Chinese PLA General Hospital from January 2001 to January 2022 were retrospectively enrolled in this study. Results: More than half of the patients were postmenopausal patients, especially those with neuroendocrine neoplasm (62.96%). There were more patients with human epidermal growth factor receptor 2 negative and hormone receptor positive tumors, and most of them were Luminal B type (71.26%). The multivariate analysis showed that diabetes and stage IV disease were related to the progression-free survival of breast carcinoma with neuroendocrine features patients (p = 0.004 and p < 0.001, respectively). Conclusion: Breast carcinoma with neuroendocrine features tended to be human epidermal growth factor receptor 2 negative and hormone receptor positive tumors, most of them were Luminal B type, and the related factors of progression-free survival were diabetes and stage IV disease.
Principles of Treatment and Clinical-Evolutionary Peculiarities of Deep Cervical Spaces Suppurations—Clinical Study
Authors: Jicman (Stan) Daniela , Sârbu Nicolae , Rebegea Laura-Florentina , Crăescu Mihaela , Niculeț Elena , Țuța Maria-Daniela , Nechita Aurel , Nicolescu Alin Codruț , Tatu Alin Laurențiu
Published: February 2023

As medical-surgical emergencies, regardless of the causal agent, deep cervical space suppurations are not only a diagnostic challenge, but also a therapeutic one. In some cases, in spite of proper therapeutic measures, extremely severe complications can develop. A 5-year retrospective study (2016–2020) was conducted on a group of 107 patients suffering from cervical suppurations, being hospitalized and treated in the ENT Clinic of the “Sf. Apostol Andrei” Emergency County Hospital of Galați. This research is a clinical-statistical study based on the experience of this ENT clinic and was carried out based on the analysis of the patients’ medical records. Descriptive analysis’ statistical methods of the data series collected from the clinical observation sheets were used, with the patients’ informed consent for the processing of the aforementioned data, with the agreement of the Ethics Commission of the Emergency Clinical Hospital “Sf. Apostol Andrei” Galați and the College of Physicians Galați, România. The patients’ clinical and multidisciplinary treatment features included in the study group are presented. The results highlight the clinical particularities of deep cervical space suppurations treatment, including under COVID-19 impact, or with other comorbidities, having consequences on the case mix index increase or directly on the costs, admittance duration and the clinical status of the patient at discharge. The conclusions of the clinical study are based on the fulfillment of the research objectives in terms of treatment and symptomatology of deep cervical space suppurations and under the impact of comorbidities (global health crisis and pandemic, triggering of comorbidities due to health care access difficulty in the context of anti-COVID-19 government-implemented measures and the infection-rate that overburdened the medical system in the early period of the pandemic). Individualized treatment of deep cervical space suppurations is recommended to be approached multidisciplinary. Of particular importance is early diagnosis combined with prompt and correctly instituted multidisciplinary treatment. In this context, an appropriate medical measure that we recommend is patient health education, as it was observed in the clinical study: most times, patients address medical services with advanced disease, hence the generally unfavorable prognosis and outcome (about 25% of patients develop unfavorable prognosis and 4% die).
Exploring the Role of ACE2 as a Connecting Link between COVID-19 and Parkinson’s Disease
Authors: Angelopoulou Efthalia , Karlafti Eleni , Georgakopoulou Vasiliki E. , Papalexis Petros , Papageorgiou Sokratis G. , Tegos Thomas , Savopoulos Christos
Published: February 2023

Coronavirus disease 2019 (COVID-19) is frequently accompanied by neurological manifestations such as headache, delirium, and epileptic seizures, whereas ageusia and anosmia may appear before respiratory symptoms. Among the various neurological COVID-19-related comorbidities, Parkinson’s disease (PD) has gained increasing attention. Some cases of PD disease have been linked to COVID-19, and both motor and non-motor symptoms in Parkinson’s disease patients frequently worsen following SARS-CoV-2 infection. Although it is still unclear whether PD increases the susceptibility to SARS-CoV-2 infection or whether COVID-19 increases the risk of or unmasks future cases of PD, emerging evidence sheds more light on the molecular mechanisms underlying the relationship between these two diseases. Among them, angiotensin-converting enzyme 2 (ACE2), a significant component of the renin-angiotensin system (RAS), seems to play a pivotal role. ACE2 is required for the entry of SARS-CoV-2 to the human host cells, and ACE2 dysregulation is implicated in the severity of COVID-19-related acute respiratory distress syndrome (ARDS). ACE2 imbalance is implicated in core shared pathophysiological mechanisms between PD and COVID-19, including aberrant inflammatory responses, oxidative stress, mitochondrial dysfunction, and immune dysregulation. ACE2 may also be implicated in alpha-synuclein-induced dopaminergic degeneration, gut–brain axis dysregulation, blood–brain axis disruption, autonomic dysfunction, depression, anxiety, and hyposmia, which are key features of PD.
The Mechanism of Hyperglycemia-Induced Renal Cell Injury in Diabetic Nephropathy Disease: An Update
Authors: Wu Tong , Ding Lei , Andoh Vivian , Zhang Jiaxin , Chen Liang
Published: February 2023

Diabetic Nephropathy (DN) is a serious complication of type I and II diabetes. It develops from the initial microproteinuria to end-stage renal failure. The main initiator for DN is chronic hyperglycemia. Hyperglycemia (HG) can stimulate the resident and non-resident renal cells to produce humoral mediators and cytokines that can lead to functional and phenotypic changes in renal cells and tissues, interference with cell growth, interacting proteins, advanced glycation end products (AGEs), etc., ultimately resulting in glomerular and tubular damage and the onset of kidney disease. Therefore, poor blood glucose control is a particularly important risk factor for the development of DN. In this paper, the types and mechanisms of DN cell damage are classified and summarized by reviewing the related literature concerning the effect of hyperglycemia on the development of DN. At the cellular level, we summarize the mechanisms and effects of renal damage by hyperglycemia. This is expected to provide therapeutic ideas and inspiration for further studies on the treatment of patients with DN.
Dibenzyl-(1S*,2S*)-2,3-dihydro-1H-indene-1,2-dicarboxylate
Authors: Olivieri Diego , Tarroni Riccardo , Carfagna Carla
Published: February 2023

The synthesis of dibenzyl-(1S*,2S*)-2,3-dihydro-1H-indene-1,2-dicarboxylate has been realized through a diastereospecific bis-alkoxycarbonylation reaction, which starts from the cheap and easily available 1H-indene, benzyl alcohol, and carbon monoxide. The catalyst is formed in situ by mixing Pd(TFA)2, the ligand N2,N3-bis(2,6-dimethylphenyl)butane-2,3-diimine, p-benzoquinone is used as an oxidant, and benzyl alcohol acts both as a nucleophile and as the main solvent.
3-Methyl-1-phenyl-4-thioacetylpyrazol-5-one
Authors: Petkova Zhanina , Rusew Rusi , Shivachev Boris , Kurteva Vanya
Published: February 2023

The novel compound 3-methyl-1-phenyl-4-thioacetylpyrazol-5-one is obtained in excellent yield via a thionation of the corresponding oxygen analogue. The product is isolated in pure form using column chromatography and is characterised using 1D and 2D NMR experiments, ATR IR and HRMS spectra, and single-crystal XRD.
Triethylammonium 2-(3-Hydroxy-2-oxoindolin-3-yl)-5,5-dimethyl-3-oxocyclohex-1-en-1-olate
Authors: Ryzhkova Yuliya E. , Ryzhkov Fedor V. , Elinson Michail N.
Published: February 2023

In recent years, the application of privileged structures has become a powerful approach in the discovery of new biologically active molecules. Ion pairing is a strategy used to enhance the permeation of ionized topical drugs. A convenient and efficient method for the synthesis of triethylammonium 2-(3-hydroxy-2-oxoindolin-3-yl)-5,5-dimethyl-3-oxocyclohex-1-en-1-olate has been developed. The presented protocol includes an aldol reaction and the formation of an ammonium salt. Triethylamine is both a reactant and a catalyst in the process. The structure of the synthesized title compound has been established by 1H, 13C-NMR and IR spectroscopy, mass spectrometry, and elemental analysis.
Hydrogen Storage Performance of Mg/MgH2 and Its Improvement Measures: Research Progress and Trends
Authors: Yang Xinglin , Li Wenxuan , Zhang Jiaqi , Hou Quanhui
Published: February 2023

Due to its high hydrogen storage efficiency and safety, Mg/MgH2 stands out from many solid hydrogen storage materials and is considered as one of the most promising solid hydrogen storage materials. However, thermodynamic/kinetic deficiencies of the performance of Mg/MgH2 limit its practical applications for which a series of improvements have been carried out by scholars. This paper summarizes, analyzes and organizes the current research status of the hydrogen storage performance of Mg/MgH2 and its improvement measures, discusses in detail the hot studies on improving the hydrogen storage performance of Mg/MgH2 (improvement measures, such as alloying treatment, nano-treatment and catalyst doping), and focuses on the discussion and in-depth analysis of the catalytic effects and mechanisms of various metal-based catalysts on the kinetic and cyclic performance of Mg/MgH2. Finally, the challenges and opportunities faced by Mg/MgH2 are discussed, and strategies to improve its hydrogen storage performance are proposed to provide ideas and help for the next research in Mg/MgH2 and the whole field of hydrogen storage.
Silver Nanoparticles for Fluorescent Nanocomposites by High-Pressure Magnetron Sputtering
Authors: Zikmund Tomáš , Bulíř Jiří , Novotný Michal , Fekete Ladislav , Chertopalov Sergii , Irimiciuc Stefan Andrei , Klementová Mariana , Balogová Jarmila , Lančok Jan
Published: February 2023

We report on the formation of silver nanoparticles by gas aggregation in a reaction chamber at room temperature. The size distribution of nanoparticles deposited on a silicon substrate for various lengths of an aggregation (high-pressure) chamber was investigated by atomic force microscopy. Nanoparticles were characterized by scanning and transmission electron microscopy and spectral ellipsometry. The physical shape of the nanoparticles and its distribution was correlated with their optical properties. Metal–dielectric nanocomposites were deposited employing simultaneous deposition of Ag NPs via high-pressure magnetron sputtering and the dielectric matrix was deposited via thermal evaporation. Pure and Eu-, Er-, and Yb-doped lithium fluoride was used as the dielectric host matrix. Optical transmittance of lithium fluoride containing silver nanoparticles was measured and their theoretical absorption cross-section calculated. The nanoparticles were also embedded in Eu3+-doped downshifting and Er3+- and Yb3+-doped up-conversion materials to study their influence on emission spectra. Spectra of identical layers with and without nanoparticles were compared. Their transmittance at various annealing temperatures is also presented.
Effect of AISI H13 Steel Substrate Nitriding on AlCrN, ZrN, TiSiN, and TiCrN Multilayer PVD Coatings Wear and Friction Behaviors at a Different Temperature Level
Authors: Özkan Doğuş , Yilmaz Mustafa Alper , Karakurt Deniz , Szala Mirosław , Walczak Mariusz , Bakdemir Seda Ataş , Türküz Cenk , Sulukan Egemen
Published: February 2023

Moving components of industrial machines and tools are subjected to wear and friction. This reduces their useful life and efficiency in running conditions, particularly at high temperatures. One of the most popular solutions is to apply an appropriate surface coating to the tribocouple’s base materials. In this study, tribometer experiments were used to evaluate the tribological performance of cathodic arc physical vapor deposited (CAPVD) AlCrN, TiSiN, CrTiN, and ZrN coatings on the gas nitrided AISI H13 tool steel to explore the effects of nitriding the steel on wear and friction behavior of these coatings at ambient and elevated temperatures. The coatings characterization is split into three main parts: mechanical, morphological, and chemical characterization. Nanoindentation has been used for mechanical characterization, thin film X-ray diffraction (XRD), and an energy-dispersive X-ray spectrometer mounted on a scanning electron microscope for chemical characterization, optical profilometer, and atomic force microscopy (AFM) for morphological characterization. Significant improvements in the adhesion qualities of the coatings to the substrate were achieved as a result of nitration. Due to this circumstance, the coatings’ load-bearing capacity and high-temperature wear resistance ratings were enhanced. The wear results showed that the AISI H13 tool steel nitriding with AlCrN and ZrN layers decreased wear rates by two to three times at 700 °C.
Simulation and Verification of Effect of Arc Duration on Arc Temperature Based on COMSOL
Authors: Yu Xiaoying , Song Mengjie , Wang Ze
Published: February 2023

The pantograph–catenary arc of urban rail has the characteristic of high temperature, which directly acts on the surface of the pantograph–catenary system, will seriously ablate pantograph and contact line, and affect the flow of the pantograph–catenary system. In this paper, based on MHD, a mathematical model of the arcing of urban rail pantograph–catenary system is established. COMSOL finite element software was used to simulate the arc temperature field of the pantograph–catenary arc. Through the temperature distribution cloud diagram and related images, the relationship between the arc central temperature, the duration, and the gap of the pantograph arc were studied. It is found that the arc temperature increases with the increase in arc duration when the arc gap is fixed. When the arc duration is fixed, the arc center temperature changes inversely with the increase in the arc gap. The feasibility of the simulation model is verified by the pantograph–catenary arc experiment platform. The research conclusion of this paper can provide a certain basis for the research of arc erosion on the surface of the pantograph–catenary system.
State Estimation of Positive Switched Interval Systems with Metzler–Takagi–Sugeno Fuzzy Models
Authors: Krokavec Dušan , Filasová Anna
Published: February 2023

This paper addresses the problem of estimating the state of a class of interval and positive nonlinear switched systems. The considered system class is represented by Metzler–Takagi–Sugeno fuzzy switched models with positive Lipschitz nonlinear functions and bounded disturbance. The fuzzy switching interval observers need real-time measurable values of premise variables. The introduced design method in this paper allows us to compute the lower and upper bounds of the system state under assumption that unknown disturbances are norm-bounded, computing the observer gain to achieve such robustness. Formulations and proofs of the design condition for switching fuzzy positive interval observers document that the diagonal stabilisation principle is implementable by a common set of LMIs in the construction of strictly positive interval observer gains, guaranteeing Metzler and Hurwitz observer system matrices and positiveness of the lower and upper bounds of the estimated system states. Design conditions for the interval-switching observer structures are formulated via linear matrix inequalities to also ensure H∞-norm disturbance attenuation and corresponding Lipschitz parameter upper bounds. The proposed algorithm structures are informal and easily creatable as is illustrated by a numerical example.
Numerical Analysis and Parametric Optimization of T-Shaped Symmetrical Metasurface with Broad Bandwidth for Solar Absorber Application Based on Graphene Material
Authors: Alsharari Meshari , Armghan Ammar , Aliqab Khaled
Published: February 2023

Solar energy is an essential renewable energy source among all the other renewable energy sources. It is possible to improve the efficiency of the solar energy absorber by increasing the solar energy absorber’s capacity for absorption, which can help in building better solar-based renewable energy devices. The need of covering the whole solar spectrum led us to design this T-shaped metasurface solar absorber which is based on graphene material. The T-shaped absorber gives 90, 88 and 57% absorption in the visible, infrared and UV regions, respectively. This symmetrical structure is also periodic with respect to x-axis and y-axis. This solar absorber demonstrates better efficiency compared to many other existing solar absorbers. The solar absorber is also compared with two other square-1 and square-2 designs to show the improvement in solar energy absorption. The parametric optimization method is applied to optimize the design. The parameters, such as the length and width of the substrate and the thicknesses of the T-shaped metasurface and substrate, are varied to find out the optimized design for maximum solar energy absorption. The optimized parameters obtained from the optimization are 1000, 2500, 3000 and 3000 nm, for resonator thickness, substrate thickness, substrate length and substrate width, respectively. The design results for graphene material and its potential variation are also observed. The design also shows good absorption for a wide-angle of incidence of about 0 to 50°. The increased efficiency of this design can be applied in future solar absorber devices.
Ultimately Exponentially Bounded Estimates for a Class of Nonlinear Discrete−Time Stochastic Systems
Authors: Miao Xiufeng , Xu Yaoqun , Yao Fengge
Published: February 2023

In this paper, the ultimately exponentially bounded estimate problem of nonlinear stochastic discrete−time systems under generalized Lipschitz conditions is considered. A new sufficient condition making the estimation error system uniformly exponentially bounded in the mean square sense is given. The gain matrix can be obtained by solving matrix inequality. In the last section, numerical examples are provided verify the effectiveness of the conclusions.
Impact-Angle-Control Guidance Law with Terminal Constraints on Curvature of Trajectory
Authors: Song Kyoung-Rok , Jeon In-Soo
Published: February 2023

This paper presents an impact-angle-control guidance law with terminal constraints on the curvature of the missile trajectory. The formulation takes into account nonlinear kinematics and time-varying velocity, allowing for more general cases in which the flight path angle may not be small throughout the entire trajectory. The proposed optimal guidance law aims to minimize the change rate of pseudo-curvature, which is defined as a curvature with weighting factors based on the flight-path angle and range to go. The analysis shows that the trajectories generated by this nonlinear guidance law have a simple polynomial form with respect to downrange. Numerical simulations demonstrate that the cost function parameter can be used to shape the trajectories along the downrange.
Breast Abnormality Boundary Extraction in Mammography Image Using Variational Level Set and Self-Organizing Map (SOM)
Authors: Ghani Noor Ain Syazwani Mohd , Jumaat Abdul Kadir , Mahmud Rozi , Maasar Mohd Azdi , Zulkifle Farizuwana Akma , Jasin Aisyah Mat
Published: February 2023

A mammography provides a grayscale image of the breast. The main challenge of analyzing mammography images is to extract the region boundary of the breast abnormality for further analysis. In computer vision, this method is also known as image segmentation. The variational level set mathematical model has been proven to be effective for image segmentation. Several selective types of variational level set models have recently been formulated to accurately segment a specific object on images. However, these models are incapable of handling complex intensity inhomogeneity images, and the segmentation process tends to be slow. Therefore, this study formulated a new selective type of the variational level set model to segment mammography images that incorporate a machine learning algorithm known as Self-Organizing Map (SOM). In addition to that, the Gaussian function was applied in the model as a regularizer to speed up the processing time. Then, the accuracy of the segmentation’s output was evaluated using the Jaccard, Dice, Accuracy and Error metrics, while the efficiency was assessed by recording the computational time. Experimental results indicated that the new proposed model is able to segment mammography images with the highest segmentation accuracy and fastest computational speed compared to other iterative models.
AutoGAN: An Automated Human-Out-of-the-Loop Approach for Training Generative Adversarial Networks
Authors: Nazari Ehsan , Branco Paula , Jourdan Guy-Vincent
Published: February 2023

Generative Adversarial Networks (GANs) have been used for many applications with overwhelming success. The training process of these models is complex, involving a zero-sum game between two neural networks trained in an adversarial manner. Thus, to use GANs, researchers and developers need to answer the question: “Is the GAN sufficiently trained?”. However, understanding when a GAN is well trained for a given problem is a challenging and laborious task that usually requires monitoring the training process and human intervention for assessing the quality of the GAN generated outcomes. Currently, there is no automatic mechanism for determining the required number of epochs that correspond to a well-trained GAN, allowing the training process to be safely stopped. In this paper, we propose AutoGAN, an algorithm that allows one to answer this question in a fully automatic manner with minimal human intervention, being applicable to different data modalities including imagery and tabular data. Through an extensive set of experiments, we show the clear advantage of our solution when compared against alternative methods, for a task where the GAN outputs are used as an oversampling method. Moreover, we show that AutoGAN not only determines a good stopping point for training the GAN, but it also allows one to run fewer training epochs to achieve a similar or better performance with the GAN outputs.
Hybrid Backstepping Control of a Quadrotor Using a Radial Basis Function Neural Network
Authors: Maaruf Muhammad , Hamanah Waleed M. , Abido Mohammad A.
Published: February 2023

This article presents a hybrid backstepping consisting of two robust controllers utilizing the approximation property of a radial basis function neural network (RBFNN) for a quadrotor with time-varying uncertainties. The quadrotor dynamic system is decoupled into two subsystems: the position and the attitude subsystems. As part of the position subsystem, adaptive RBFNN backstepping control (ANNBC) is developed to eliminate the effects of uncertainties, trace the quadrotor’s position, and provide the desired roll and pitch angles commands for the attitude subsystem. Then, adaptive RBFNN backstepping is integrated with integral fast terminal sliding mode control (ANNBIFTSMC) to track the required Euler angles and improve robustness against external disturbances. The proposed technique is advantageous because the quadrotor states trace the reference states in a short period of time without requiring knowledge of dynamic uncertainties and external disturbances. In addition, because the controller gains are based on the desired trajectories, adaptive algorithms are used to update them online. The stability of a closed loop system is proved by Lyapunov theory. Numerical simulations show acceptable attitude and position tracking performances.
Deep Reinforcement Learning Heterogeneous Channels for Poisson Multiple Access
Authors: Zhang Xu , Chen Pingping , Yu Genjian , Wang Shaohao
Published: February 2023

This paper proposes a medium access control (MAC) protocol based on deep reinforcement learning (DRL), i.e., multi-channel transmit deep-reinforcement learning multi-channel access (MCT-DLMA) in heterogeneous wireless networks (HetNets). The work concerns practical unsaturated channel traffic that arrives following a Poisson distribution instead of saturated traffic that arrives before.By learning the access mode from historical information, MCT-DLMA can well fill the spectrum holes in the communication of existing users. In particular, it enables the cognitive user to multi-channel transmit at a time, e.g., via the multi-carrier technology. Thus, the spectrum resource can be fully utilized, and the sum throughput of the HetNet is maximized. Simulation results show that the proposed algorithm provides a much higher throughput than the conventional schemes, i.e., the whittle index policy and the DLMA algorithms for both the saturated and unsaturated traffic, respectively. In addition, it also achieves a near-optimal result in dynamic environments with changing primary users, which proves the enhanced robustness to time-varying communications.
Utility of Opportunistic Infections, Joints’ Involvement and Accuracy of Various Screening Tests to Diagnose Rheumatoid Arthritis Patients
Authors: Ahmad Ausaf , Khan Ashfaque , Khan Abdur Raheem , Ahmed Hashim , Alajam Ramzi Abdu , Alshehri Mohammed M. , Ganesan Bhuvanesh Babu Mondey , Dayah Salma Jabril Abu , Shaphe Mohammad Abu , Alameer Abdulaziz H. , Esht Vandana
Published: February 2023

Background and Objectives: Rheumatoid Arthritis (RA) is an auto-immune disease in which the body mistakenly considers some parts of its own system as pathogens and attacks them. Prevalence is approximately 0.75% in India. About 40% of the diseased become work disabled within 5 years from the onset of symptoms. The objective of this paper is to assess the sign/symptoms, joints’ involvement, difficulties in daily activities and screening accuracy of serology tests of clinically suspected RA patients. Material and Methods: A cross-sectional cohort study design was conducted on two hundred ninety clinically suspected subjects who were referred by different OPDs of hospitals for screening. The profiles of study subjects were carried through a semi-structured, pre-tested schedule method. About 2 mL of blood samples were collected in a plain vial from each patient and tested for diagnostic tests RF, CRP and AntiCCP by using RF-Latex, CRP Latex and ELISA method, respectively, by the laboratory persons. Results: Joint pain shows to be a leading problem in RA as compared to other signs and symptoms. The majority of the study subjects suffer from knee problems (62%). Approximately equal numbers of RA-positive cases were screened by RF and AntiCCP tests. The CRP test screened about one-third of cases. CRP+ AntiCCP, RF+ AntiCCP and RF + CRP all have good sensitivity, and RF+ AntiCCP + CRP has a very high sensitivity for diagnosing RA. Conclusions: This study found that a substantiation of a major proportion of clinically suspected RA patients were suffering from knee pain. Predication of AntiCCP increased the possibility for the diagnosis of RA. However, RF was also moderately related to the diagnosis of RA, and the combination of both tests was more valuable.