bluuebunny/crossref_metadata_2025 huggingface dataset:
Non‐contact monitoring of human heartbeat signals using mm‐wave frequency‐modulated continuous‐wave radar under low signal‐to‐noise ratio conditions
Authors: Zhang Wenyu , Li Gang , Wang Zetao , Wu Hao
Published: November 2021

Radar has been shown potentially to be used for non‐contact sensing of biosignals in a more comfortable and easier way than wearable and contact devices. By detecting and extracting body motions linked to physiological activities, accurate estimation of the heart rate is possible. However, the detection and estimation of heartbeat signal in practical applications is disturbed seriously by noise and respiration harmonic signal. In this study, a multi‐level coarse‐to‐fine method is proposed for heartbeat rate (HR) estimation with a frequency‐modulated continuous‐wave radar operating at 60 GHz utilised to extract the heartbeat information of human body under low signal‐to‐noise ratio conditions. First, the frequencies, which are likely to be the HR, are extracted in the coarse estimation part. Then, evaluations about the extracted frequencies are conducted in the fine estimation part. Finally, the multiple signal classification algorithm is utilised to separate the HR frequency from the respiration harmonics, which solves the frequency resolution issue caused by the observation window size, and achieves high accuracy estimation of HR. The experiments on measured data demonstrate the effectiveness of the proposed method. Compared with the state of the art, the proposed method has superiority in terms of estimation accuracy of HR.
[CII] line intensity mapping the epoch of reionization with the Prime-Cam on FYST
Authors: Karoumpis C. , Magnelli B. , Romano-Díaz E. , Haslbauer M. , Bertoldi F.
Published: November 2021

Aims. We predict the three-dimensional intensity power spectrum (PS) of the [CII] 158 μm line throughout the epoch of (and post) reionization at redshifts from ≈3.5 to 8. We study the detectability of the PS in a line intensity mapping (LIM) survey with the Prime-Cam spectral-imager on the Fred Young Submillimeter Telescope (FYST).

Methods. We created mock [CII] tomographic scans in redshift bins at z ≈ 3.7, 4.3, 5.8, and 7.4 using the Illustris TNG300-1 ΛCDM simulation and adopting a relation between the star formation activity and the [CII] luminosity (L[CII]) of galaxies. A star formation rate (SFR) was assigned to a dark matter halo in the Illustris simulation in two ways: (i) we adopted the SFR computed in the Illustris simulation and, (ii) we matched the abundance of the halos with the SFR traced by the observed dust-corrected ultraviolet luminosity function of high-redshift galaxies. The L[CII] is related to the SFR from a semi-analytic model of galaxy formation, from a hydrodynamical simulation of a high-redshift galaxy, or from a high-redshift [CII] galaxy survey. The [CII] intensity PS was computed from mock tomographic scans to assess its detectability with the anticipated observational capability of the FYST.

Results. The amplitude of the predicted [CII] intensity power spectrum varies by more than a factor of 10, depending on the choice of the halo-to-galaxy SFR and the SFR-to-L[CII] relations. In the planned 4° ×4° FYST LIM survey, we expect a detection of the [CII] PS up to z ≈ 5.8, and potentially even up to z ≈ 7.4. The design of the envisioned FYST LIM survey enables a PS measurement not only in small (< 10 Mpc) shot noise-dominated scales, but also in large (> 50 Mpc) clustering-dominated scales making it the first LIM experiment that will place constraints on the SFR-to-L[CII] and the halo-to-galaxy SFR relations simultaneously.
On-sky validation of image-based adaptive optics wavefront sensor referencing
Authors: Skaf Nour , Guyon Olivier , Gendron Éric , Ahn Kyohoon , Bertrou-Cantou Arielle , Boccaletti Anthony , Cranney Jesse , Currie Thayne , Deo Vincent , Edwards Billy , Ferreira Florian , Gratadour Damien , Lozi Julien , Norris Barnaby , Sevin Arnaud , Vidal Fabrice , Vievard Sébastien
Published: November 2021

Context.Differentiating between a true exoplanet signal and residual speckle noise is a key challenge in high-contrast imaging (HCI). Speckles result from a combination of fast, slow, and static wavefront aberrations introduced by atmospheric turbulence and instrument optics. While wavefront control techniques developed over the last decade have shown promise in minimizing fast atmospheric residuals, slow and static aberrations such as non-common path aberrations (NCPAs) remain a key limiting factor for exoplanet detection. NCPAs are not seen by the wavefront sensor (WFS) of the adaptive optics (AO) loop, hence the difficulty in correcting them.

Aims.We propose to improve the identification and rejection of slow and static speckles in AO-corrected images. The algorithm known as the Direct Reinforcement Wavefront Heuristic Optimisation (DrWHO) performs a frequent compensation operation on static and quasi-static aberrations (including NCPAs) to boost image contrast. It is applicable to general-purpose AO systems as well as HCI systems.

Methods.By changing the WFS reference at every iteration of the algorithm (a few tens of seconds), DrWHO changes the AO system point of convergence to lead it towards a compensation mechanism for the static and slow aberrations. References are calculated using an iterative lucky-imaging approach, where each iteration updates the WFS reference, ultimately favoring high-quality focal plane images.

Results.We validated this concept through both numerical simulations and on-sky testing on the SCExAO instrument at the 8.2-m Subaru telescope. Simulations show a rapid convergence towards the correction of 82% of the NCPAs. On-sky tests were performed over a 10 min run in the visible (750 nm). We introduced a flux concentration (FC) metric to quantify the point spread function (PSF) quality and measure a 15.7% improvement compared to the pre-DrWHO image.

Conclusions.The DrWHO algorithm is a robust focal-plane wavefront sensing calibration method that has been successfully demonstrated on-sky. It does not rely on a model and does not require wavefront sensor calibration or linearity. It is compatible with different wavefront control methods, and can be further optimized for speed and efficiency. The algorithm is ready to be incorporated in scientific observations, enabling better PSF quality and stability during observations.
Fast growth of pure V2O5 nanoparticles by low-cost hydrothermal process
Authors: Ferhati Fariza , Simo Aline , Belkaid Mohammed S. , Maaza Malek , Boussoum Ouiza , Hocine Dalila
Published: November 2021

Vanadium pentoxide (V2O5) nanorods were successfully grown through an easy, quick and clean hydrothermal method using vanadium oxide sols (V2O5.1,6H2O) as precursor. Structurals studies based on the X-ray diffraction and Raman spectroscopy revealed that the synthesized nanomaterials are pure divanadium pentoxide with an orthorhombic phase. The morphological properties and the particle size of the developed V2O5 nanoparticles were investigated by scanning electron microscopy (SEM) and high resolution transmission electron microscope (HRTEM). The results show that the as-grown samples consist of a large amount of one-dimensional V2O5 nanorods with the widths approximately 52 nm and the lengths are up to several hundred nanometers. The effects of different growth conditions, such as hydrothermal duration and stirring temperature of the precursor on the formation of the nanorods has been recorded. Moreover, the structural and morphological properties of the resulting nanopowders have been experimentally studied. Time-dependent experiments showed that V2O5.1,6H2O were dehydrated progressively and transformed into orthorhombic V2O5 single-crystalline nanorods. It has been established that high stirring temperature of the precursor is benefical for the formation of V2O5 nanorods and minimizes the duration time of the heat treatment. Hence the adjusted parameters (time and temperature) appears to be the key element to achieving the desired nanomaterial with defined forms.
Nanostructured LaFeO3/Si thin films grown by pulsed laser deposition
Authors: Jędrusik Mateusz , Turquat Christian , Cieniek Łukasz , Kopia Agnieszka , Leroux Christine
Published: November 2021

The orthorhombic LaFeO3thin films grown by pulsed laser deposition on silicon showed nano-structuration of their surface and preferential crystallographic exposed facets, depending on the deposition temperature. The LaFeO3film deposited at 850 °C has two types of grain termination, flat or tip-like, corresponding to two different growth directions, respectively [110] and [200]. However, due to the shape of the termination, the two types of grains expose the same {110} facets. The prepared lanthanum iron oxide films are iron deficient and consequently contains oxygen vacancies, the exact chemical formula being LaFe0.82O3-δ.
Validation of a thermal non-equilibrium Eulerian-Eulerian multiphase model of a 620 MWe pulverized fuel power boiler
Authors: Rawlins Brad , Laubscher Ryno , Rousseau Pieter
Published: November 2021

The use of a thermal non-equilibrium Eulerian-Eulerian model for the simulation of a 620 MWe power boiler is proposed for capturing the combustion and radiative heat transfer found in the pulverized fuel systems. The models eliminates the use of a Lagrangian reference frame in tracking solid fuel particles thereby reducing the computational expense and time. The model solves the scalar transport for the particle mass, energy and radiation interactions between the pseudo-particle and continuous phases. The goal is to apply the modelling approach to generate a simulation database for different load cases and firing conditions which in turn will be used to study flexible operation. The model is validated against both numerical and applicable site data measurements. It is shown that the model is able to adequately resolve the furnace and superheater wall heat fluxes. Additionally the resolution of the flow field, combustion dynamics and wall fluxes are demonstrated for both an 80% and 60% operational loads. Moreover, it is shown that the Eulerian-Eulerian model results in approximately a 30% computational resource reduction when compared to traditional modelling approaches.
Development and validation of a robust integrated thermal power plant model for load loss analysis and identification
Authors: Marx Alton , Rousseau Pieter , Laubscher Ryno
Published: November 2021

The development of deep learning methodologies for the analysis of thermal power plant load losses requires a combination of real plant data and data derived from fundamental physics-based process models. For this purpose, a robust integrated power plant thermofluid process model of a complete +600MW coal-fired power plant was developed within the Flownex Simulation Environment. It consists of standard and compound components, combined with specially developed scripts to ensure complete energy balance, specifically on the two-phase tank components. This enables simulation of the complete plant operation to determine power output as a function of any given set of internal and external operational variables, boundary conditions and component states. The model was validated against real plant design and acceptance test data. In order to demonstrate the ability of the model it was used to evaluate the plant performance related to three specific load loss inducing scenarios. The results show that a combination of mechanical faults, process anomalies and operational phenomena can be analysed. This provides the basis for generating model-based performance data that can be combined with real plant data to facilitate the development of deep learning analytics tools for load loss fault diagnosis and root cause analysis, as well as fault propagation and load loss forecasting.
Neural Network for Modeling the Mechanical Properties of Gelatin-Cellulose Nanocrystals Hydrogel Membrane for Heavy Metal ions Removal from Wastewater
Authors: Kabuba John
Published: November 2021

The mechanical properties of Gelatin-cellulose nanocrystals hydrogel membrane were investigated for the removal of heavy metal ions from wastewater. The membrane was characterized using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) analysis. Neural Network (NN) model was developed to predict the mechanical properties such as Young’s modulus, tensile strength, and elongation. The NN predicted results are very close to the experimental results with R2 = 0.99315. The predicted values were found to be in excellent agreement with the experimental data and the current model has a good learning precision and generalization. The results revealed that the developed model is very accurate.
A review of composite leaf springs for automotive vehicles
Authors: Manaba Brighton , Hashe Vuyo T
Published: November 2021

In the quest to conserve natural resources and economic energy. Weight reduction has been the focus of auto-manufactures and the aerospace industry in the present day. Weight reduction can be archived primarily by introducing better design optimization, better material, and improved manufacturing processes. This approach by introducing composite materials into automobile industries, which has high strength to weight ratio and excellent corrosive resistance, can fulfil the requirement. This review paper investigates the use of composite materials in the design of leaf springs for automotive vehicles. The paper underscores the suitability of composite materials for leaf spring in automobiles and develops a new leaf spring design that optimizes weight reduction and strength. The review provides details regarding previous efforts conducted on the design of leaf springs while outlining the knowledge gap areas. This review commences with an introduction to leaf springs and a brief history of their development. Followed by the properties that make an excellent leaf spring, this helps narrow down the information required for further developments providing avenues for possible future research.
Numerical investigation of the hydrocyclone vortex finder depth on separation efficiency
Authors: Mokonyama Lesiba , Kunene Thokozani Justin , Tartibu Lagouge Kwanda
Published: November 2021

Hydrocyclones are devices used in numerous chemicals, food, and mineral-related industrial sectors for the separation of fine particles. A d50 mm hydrocyclone was modelled with the use of the Computational fluid dynamics (CFD) simulation, ANSYS® Fluent 2021 R1. The vortex finder depth was varied from 20 mm, 30 mm, and 35 mm to observe the effects of pressure drop and separation efficiency from a varied vortex finder depth and characteristics of the air core. The numerical methods validated the results observed from different parameters such as volume fraction characteristics based on CFD simulations. The tangential and axial velocities increased as the vortex finder length increased. It was found that as the depth of the vortex finder is increased, particle re-entrainment time in the underflow stream increases, and separation efficiency improved.
The role of the organizational culture of trust in the formation of regional social capital
Authors: Kolmykova Marina Alexandrovna , Korneeva Elena Nikolaevna
Published: November 2021

The article discusses the problem of reducing the level of trust in various social institutions, including public authorities. It is shown that this problem is an obstacle to the formation of regional social capital. The research purpose is to determine the role of the organizational culture of trust in the process of formation and accumulation of regional social capital. Based on the study, it was found that the integrated level of trust is most observed in the social institution of the family, and the lowest one – in the social institution of the state, this confirms the tendency of a significant decrease in the level of trust in public authorities and, in turn, this prevents the accumulation of social capital in regions. It has been established that today regions face socio-economic challenges, namely: a pandemic, digitalization of social relations, changes in the labor market, the outflow of talented young people to the capital universities, brain drain, “anti-human factor” in enterprises. It is assumed that the most rational response to the challenges will be the development of regional social capital through the organizational culture of trust in enterprises. Moreover, regional social capital can be considered as a set of social capital of citizens with a pro-active attitude, inspiring political leaders, as well as public figures, and social capital of enterprises which organizational culture is based on trust. The article notes that the formation of the organizational culture of trust can contribute to a decrease in staff turnover, an increase in labor productivity, personnel involvement, an increase in the competitiveness of an enterprise, organizational commitment, an increase in business reputation.
Female education in post-reform Russia as a social lift
Authors: Bodrova Yulia Viktorovna , Vinnik Aleksey Viktorovich , Ermishkina Olga Konstantinovna , Makarova Elena Alekseevna , Tsyganova Angelina Valerievna
Published: November 2021

A significant expansion of female education for the representatives of different classes was a progressive phenomenon of the “great reforms” of Emperor Alexander II. Against the background of social changes in Russia, women thus received additional opportunities for their socialization and work. The study of the use of female education as a social lift is of interest from the point of view of the history of social modernization. The study aims to study the experience of using female education as a social lift on the example of the Tver province of the Russian Empire. The study uses a set of methods of female and gender history and the local history approach, which collectively make it possible to focus on the regional specifics of the modernization of the female education system in the context of the individual’s everyday practices within the framework of an interdisciplinary field. Published statistical data are involved in the research; unpublished documents from the funds of regional archives are also introduced into scientific circulation. The novelty of the article lies in the recreation of the practices of using female education as a social lift in the second half of the 19th – early 20th centuries using the example of the Tver province. Various levels and forms of female education in Russia in the era of “great reforms” and the period that followed them have been studied. The mechanisms of socialization of Russian women of different classes are revealed, depending on the level of education received.
Employment problems of disabled persons: Stereotypes and employer missing
Authors: Naberushkina Elmira Kamalovna , Raidugin Dmitry Sergeevich , Voevodina Ekaterina Vladimirovna , Ikhneva Valeria Evgenievna
Published: November 2021

The article presents the results of an empirical study aimed at examining social stereotypes and established attitudes that hinder the employment of people with disabilities. To identify stereotypical ideas about the employment of people with disabilities, at the beginning of 2021, we undertook a study of two subgroups: employers (1) and people with disabilities (2). The paper presents a comparative analysis of the responses of representatives of the two groups, describes deep-rooted stereotypes, identified similarities and differences in existing attitudes about the barriers to employment of people with disabilities. The results of the study showed that people with disabilities and employers have stereotypes that either promote or, on the contrary, hinder the employment of a person with a disability. Negative stereotypes include: the idea of people with disabilities as inconvenient workers, dependents. On the other hand, employers have a fairly firmly formed setting of social responsibility and the obligation to hire people with disabilities, to promote their labor adaptation. In people with disabilities, although there is an attitude towards expectation of paternalism, the attitude towards self-development and social activity dominates. Turning to research within the framework of a qualitative methodology clarified the position of employers and showed the most vulnerable areas of employment of people with disabilities, namely, the unattractiveness of certain categories as workers and the absence of significant incentives for the employer to induce to hire people with disabilities.
New paradigm of the Russian labor market in the context of the formation of an inclusive economy and a new gender order
Authors: Sillaste Galina Georgievna
Published: November 2021

The author considers the profound changes that have occurred in the Russian labor market during the transition from a transitive economy to an inclusive one and the expanding influence of the emerging gender order, the theoretical concept of which is the theory of gender neutrality. A new paradigm for the development of the Russian labor market is proposed, which meets the radically changed economic and social conditions for the development of socio-gender labor resources in the conditions of digitalization. According to the author, a new multi-vector structure has formed in the Russian economic space, consisting of four closely interrelated markets: labor, employment, professions, and educational services. The labor market and the employment market have become the epicenter of the development of social inclusion and an inclusive economy, which have presented qualitatively different requirements for socio-gender labor resources. The complex interrelations between the four segments of the new structuration are analyzed as deep structural changes and tectonic shifts in the formation of socio-gender labor resources, the implementation of their social functions, and the reformatting of social mechanisms for managing ongoing processes. The inertial view of the labor market as a single social space does not correspond to the realities of its modern development. The article reveals the essence of the new social structuration in the context of the theory of Giddens, its architectonics, logistics of development, dialectics, and social multidimensionality. The trends in the development of a new social structuration are evaluated through the standpoint of the formation of a new gender order and the theory of gender neutrality.
Professional objectives of higher education: Imbalances and adaptation
Authors: Voronkova Elena Konstantinovna , Dolgova Mariya Vladimirovna
Published: November 2021

This article analyzes the systemic issues of personnel education in higher education, reveals their causes and consequences. Qualitative and quantitative characteristics of university graduates are one of the conditions for the state economic development. The goals and objectives of higher education should meet the needs of the state, industries, regions, and business. The lack of strong signals from consumers of educational services creates an imbalance between the higher education system and the market requirements and results in the conservatism of higher education. In this context, the purpose of this article is to develop a conceptual model for assessing the contribution of higher education to the national economy as one of the drivers of its transformation. The need to optimize the professional structure of education, with reference to the potential and prospects of the national economy, is emphasized. Research methods involve analysis and synthesis, induction and deduction, system and logical methods. The study result is a model that takes into account a number of indicators of employer satisfaction in university graduates, as well as indicators of regional and industrial security of specific professionals with higher education. An effective motivation for employers to take a more active part in the organization of higher education is the system of educational loans. The state’s management of the credit sphere creates opportunities for consumers of educational services to direct financial flows primarily to education in priority specialties. The effectiveness of this tool requires ensuring its accessibility to employers and differentiating interest rates.
Digitalization in the system of methods of scientific knowledge
Authors: Denikin Anatoly Vasilyevich , Sablukov Aleksandr Valentinovich , Primakov Viacheslav Leonidovich , Lapshov Valery Alexandrovich , Shikhgafizov Pirmagomed Shikhmagomedovich
Published: November 2021

The study aims to clarify the methodological status of digitalization in the framework of the philosophical theory of knowledge. The subject of the study: explication of the instrumental and methodological nature of digitalization. The problem is solved by employing the categorical and conceptual apparatus of philosophy of science, particularly in paradigm analysis. A comparative analysis of the concepts of “information” and “digitalization” is carried out. Information within the framework of classical scientific rationality coincides with the phenomenon of absolute-relative knowledge. In non-classical rationality, it represents a movement of meaning and expresses the value-valued nature of information technology. In postnonclassical science, the phenomenon of information is associated with intrasystemic communications. Digitalization as a mode of data transmission is incorporated into the deductive and inductive logic of classical science and leads to an essential limitation of the source base. In modern science, data selection entails the creation of systematic factual meaning, and digitalization coincides with analytical activity. In addition to general logical functions, digitalization points to new perspectives on such types of systems methodology as modeling and design. In relation to the information as a methodology, digitalization acts as a meta-methodology. That is, the digital world is defined as an observing reality. In the framework of digitalization, information is identical to knowledge in its postnonclassical meaning. In digitalization, the process of cognition is incorporated into reality itself, forming an intersubjective field of meaning. In this context, digitalization serves as an inter-paradigmatic method of scientific knowledge. Digitalization refers to the rational side of cognition and is a type of systematic methodology and general logical methods.
Development of the digital competence of students through the electronic course
Authors: Svetlova Natalia Ivanovna , Vasilieva Lydia Nikolaevna , Ilyina Irina Igorevna
Published: November 2021

The article is concerned with the role of an electronic course in higher mathematics in the development of digital competence of students of technical faculties. The principle of organizing the educational process with the help of an electronic course in higher mathematics, focused on the development of students’ digital competence, is considered. The experience of testing an electronic notebook in higher mathematics, which is part of an electronic course, is presented. The experience of the implementation of an electronic notebook in higher mathematics in teaching students at all its stages is considered: the examples of problems solved in seminars are given; the design of classroom lessons is described taking into account the specifics of the academic subject “Mathematical Analysis”. The structure of the electronic notebook, including test tasks and cases for intermediate certification of students based on the results of the seminar, is given. The effectiveness of the organization of the educational process using an electronic course in higher mathematics to develop the digital competence of students in a technical direction is shown. The work examines the attitude of students to teaching higher mathematics using an electronic course, their self-assessment of involvement in the educational process. Moreover, the educational results of the development of digital competence were demonstrated. A reliable relationship was confirmed between the level of development of digital competence and the positive attitude of students to a new format of teaching mathematics: an interactive electronic course with a component base in the form of an electronic notebook. Based on the results of the experimental work, it can be argued that the students positively assessed the use of the electronic course in teaching, because have constant access to training materials and to information about the individual trajectory of the course. This interactive development is convenient to use when preparing yourself for classes.
Synthesis of Azepine- or Azocine-Embedded Hexabenzocoronene-Based Nanographenes
Authors: An Peng , Ma Bin , Xiao Ming-Jun , Liu Pi-Jin
Published: November 2021

Classical polycyclic aromatic hydrocarbons (PAHs) are a large group of π-conjugated planar structures. To explore more properties of PAHs, new structures have been designed, including some with nonplanar topologies and heteroatom-containing moieties. As important nanographene (NG) units, hexabenzocoronene (HBC) and its derivatives have been intensively researched. Many HBC-based nonplanar NGs have been developed, and heteroatom-doped HBC-based NGs have also been designed and synthesized. Here, we summarize some methods for the synthesis of HBC-based NGs containing a seven- or eight-membered ring, and we discuss our newly synthesized NGs containing embedded azepine or azocine moieties, obtained by a modified synthetic route and a conventional Müllen’s synthetic method, respectively.
Recognition of Symmetry as a Powerful Tool in Natural Product Synthesis
Authors: Gaviria Mario A. , Kim Scott L. , Vogel Trenton R. , Schindler Corinna S. , Cala Lara
Published: November 2021

The design of concise and efficient synthetic strategies to access naturally occurring, pharmaceutically active complex molecules is of utmost importance in current chemistry. It not only enables rapid access to these molecules and their analogues but also provides sufficient quantities for their biological evaluation. Identification of any symmetric or pseudosymmetric synthetic intermediates upon retrosynthetic bond disconnection of the target molecule holds the promise to significantly streamline the route towards the compound of interest. This review will highlight recent examples of successful natural product syntheses reported within the past five years that benefited from the recognition of symmetry elements during the retrosynthetic design.

1 Introduction

2 Examples

2.1 Chondrosterin I and J

2.2 (–)-Bilobalide A

2.3 Delavatine A

2.4 Oxycodone

2.5 (–)-20-epi-vincamine and (–)-20-epi-eburnamonine

2.6 Reserpine

2.7 (–)-Berkeleyone A

2.8 (–)-Maximiscin

2.9 Aplysiasecosterol A

2.10 (–)-Batrachotoxinin A

2.11 (–)-Mitrephorone A

3 Conclusions
Applications of Photoredox Catalysis for the Radical-Induced Cleavage of C–C Bonds
Authors: Das Shoubhik , Vanderghinste Jaro
Published: November 2021

Selective cleavage of C–C bonds forms one of the greatest challenges in current organic chemistry, due to the relative strength of these bonds. However, such transformations are an invaluable instrument to break down and construct new carbon–carbon bonds. To achieve this, photochemistry can be used as a tool to generate radicals and induce the cleavage of these bonds due to their high reactivity. This review examines some of the most influential contributions in this field since 2010.

1 Introduction

2 C–C Bond Cleavage

2.1 Homogeneous Catalyst

2.1.1 N-Centered Radical

2.2.2 O-Centered Radical

2.2 Heterogeneous Catalyst

3 C=C Bond Cleavage

3.1 Homogeneous Catalyst

3.2 Heterogeneous Catalyst

4 C≡C Bond Cleavage

4.1 Homogeneous Catalyst

4.2 Heterogeneous Catalyst

5 Conclusion
Heterocyclic Mechanophores in Polymer Mechanochemistry
Authors: Yoon Hyo Jae , Jung Sangmin
Published: November 2021

This Account covers the recent progress made on heterocyclic mechanophores in the field of polymer mechanochemistry. In particular, the types of such mechanophores as well as the mechanisms and applications of their force-induced structural transformations are discussed and related perspectives and future challenges proposed.

1 Introduction

2 Types of Mechanophores

3 Methods to Incorporate Heterocycle Mechanophores into Polymer Systems

4 Mechanochemical Reactions of Heterocyclic Mechanophores

4.1 Three-Membered-Ring Mechanophores

4.2 Four-Membered-Ring Mechanophores

4.3 Six-Membered-Ring Mechanophores

4.4 Bicyclic Mechanophores

5 Applications

5.1 Cross-Linking of Polymer

5.2 Degradable Polymer

5.3 Mechanochromic Polymer

6 Concluding Remarks and Outlook
Anastomotic Troubleshooting
Authors: Sell Naomi M. , Francone Todd D.
Published: November 2021

Anastomotic leak remains a critical and feared complication in colorectal surgery. The development of a leak can be catastrophic for a patient, resulting in overall increased morbidity and mortality. To help mitigate this risk, there are several ways to assess and potentially validate the integrity of a new anastomosis to give the patient the best chance of avoiding this postoperative complication. A majority of anastomoses will appear intact with no obvious sign of anastomotic dehiscence on gross examination. However, each anastomosis should be interrogated before the conclusion of an operation. The most common method to assess for an anastomotic leak is the air leak test (ALT). The ALT is a safe intraoperative method utilized to test the integrity of left-sided colon and rectal anastomoses and most importantly allows the ability to repair a failed test before concluding the operation. Additional troubleshooting is sometimes needed due to technical difficulties with the circular stapler. Problems, such as incomplete doughnuts and stapler misfiring, do occur and each surgeon should be prepared to address them.
Anastomotic Leak after Ileal Pouch–Anal Anastomosis
Authors: Guyton Kristina , Kearney David , Holubar Stefan D.
Published: November 2021

There are special considerations when treating anastomotic leak after restorative proctocolectomy and ileal pouch–anal anastomosis. The epidemiology, risk factors, anatomic considerations, diagnosis and management, as well as the short- and long-term consequences to the patient are unique to this patent population. Additionally, there are specific concerns such as “tip of the J” leaks, transanal management of anastomotic leak/presacral sinus, functional outcomes after leak, and considerations of redo pouch procedures.
Oral Health-Related Quality of Life, Dry Mouth Sensation, and Level of Anxiety in Elderly Patients Rehabilitated with New Removable Dentures
Authors: Bannwart Lisiane Cristina , de Moraes Melo Neto Clóvis Lamartine , Goiato Marcelo Coelho , dos Santos Daniela Micheline , da Silva Paiva Cristina Aparecida , de Araújo Moreno Nathaly Vilene , da Silva Emily Vivianne Freitas , de Magalhães Bertoz André Pinheiro
Published: November 2021

Objective This study aimed to evaluate the influence of new complete dentures (CDs) and new removable partial dentures (RPDs) on oral health-related quality of life, dry mouth sensation, and anxiety level of their wearers.

Materials and Methods In total, 20 complete edentulous patients (in both arches) that needed to be rehabilitated with new CDs, and 20 partial edentulous patients (in both arches) that needed to be rehabilitated with new RPDs, were included in this study. Each patient must wear the same pair of CDs or RPDs for more than 5 years. Oral health-related quality of life, dry mouth sensation, and level of anxiety were assessed by using the following questionnaires: Geriatric Oral Health Assessment Index (GOHAI), VAS (Visual Analog Scale) Xerostomia Questionnaire, and State-Trait Anxiety Inventory (STAI). These questionnaires were applied before oral rehabilitation (initially initial time point) and 3 months after insertion of new dentures (end time point).

Statistical Analysis For the results of STAI-State, STAI-Trait, and GOHAI, the Wilcoxon test was applied to compare the time points. For the results of the VAS xerostomia questionnaire, two-way repeated measures ANOVA (analysis of variance) was applied, followed by the Tukey test. The p-values lower than 0.05 were considered statistically significant.

Results/Conclusion For both groups, it was observed that 3 months after the insertion of new removable dentures: (1) there was an increase in oral health-related quality of life; (2) there was a reduction in anxiety (trait anxiety and state anxiety); and (3) there was a perception of greater salivation.
Clinical Outcome in Cerebral Vasospasm Patients Treated with and without Intra-Arterial Nimodipine Infusion
Authors: Yindeedej Vich , Nimmannitya Pree , Noiphithak Raywat , Punyarat Prachya , Tantongtip Dilok
Published: November 2021

Background Cerebral vasospasm (CV) after aneurysmal subarachnoid hemorrhage (aSAH) is still a problem. Hypertension, hypervolemia, and hemodilution (triple-H) therapy and oral nimodipine only a modest effect on patients. Intra-arterial treatment, including nimodipine, has been studied, but only as retrospective and single-arm prospective studies. We compared the outcomes between CV patients who received an adjunct intra-arterial nimodipine infusion (IANI) and those who received the standard medical treatment alone in a prospective randomized controlled trial.

Methods In this study, patients between the age of 18 and 80 years, who underwent angiography within 14 days after aneurysm obliteration, were recruited and randomized to receive adjunct IANI or not, if they were identified with angiographic vasospasm. All the angiographic and neurologic data were recorded and analyzed during their admission, at the discharge date, and during the 6-month follow-up period.

Results From June 2016 to December 2018, we enrolled 68 patients who were randomized into two groups, 36 in the intervention group and 32 in the control group. The patients' characteristics, aneurysm data, and modalities of treatment were similar between the two groups. Within 24 hours after IANI, Glasgow Coma Scale (GCS) score and motor strength revealed a significant improvement of 33.33 and 38.89%, respectively, in the intervention group versus 12.5 and 9.38%, respectively, in the control group. At discharge, the intervention group still had significant motor improvement (58.33 vs. 21.88%; p = 0.002).

Conclusion IANI could be considered an effective treatment for CV without significant complications. This is the first RCT demonstrating statistically significant motor strength improvement within 24 hours and at discharge.
Study on Inborn and Outborn Neonatal Admissions in Relation to Gestational Maturity in Neonatal Intensive Care Unit at a Tertiary Care University Hospital in Upper Egypt
Authors: Abdel-Aziz Safwat M. , Hamed Enas A. , Shalaby Amira M.
Published: November 2021

Neonatal morbidity and mortality rates indicate a country's socioeconomic status and the quality, and effectiveness of its health care system. This research aimed to identify the clinical pattern and causes of neonatal admission for inborn and outborn babies in a tertiary care university hospital and their outcomes. Over a year, this prospective hospital-based research was conducted in the neonatal intensive care unit (NICU) of Assiut Children's Hospital in Upper Egypt (January 1st to December 31st, 2020). Gender, birth weight, gestational age, postnatal age, delivery mode, delivery place, admission cause, hospital stay period, and neonatal outcomes were collected. A total of 1,638 newborns were admitted; 930 (56.8%) were preterm and 708 (43.2%) full-term. Inborn admissions were 1,056 (64.5%) and outborn 582 (35.5%). The majority of inborn admissions were preterm 726 (68.8%), and outborn were full-term 378 (64.9%). The commonest admission causes among inborn and outborn preterm infants were respiratory distress syndrome (84.3%) and congenital intestinal obstruction (22.5%), respectively, while multiple congenital anomalies were the commonest cause for admission among both inborn and outborn full-term babies. The mortality rate was 708 (43.2%), higher among inborn (50%) versus outborn (30.9%). The leading cause of death was respiratory distress syndrome among premature inborn with case fatality rate of (56.9%) and multiple congenital anomalies among premature outborn (60%), as well as inborn (67.4%), and outborn (42.6%) full-term neonates. In conclusion, the neonatal mortality rate was high among studied cases. Morbidity and mortality of respiratory distress syndrome and congenital anomalies were alarmingly high. Therefore, all health care providers must devote a considerable effort to improve health care delivered to these neonates.
Extradural Middle Fossa and Transcavernous Approach for Resection of Trigeminal Neurinoma at Lateral Cavernous Sinus
Authors: Ono Hideaki , Torazawa Seiei , Tanishima Takeo , Tamura Akira , Saito Isamu
Published: November 2021

We present a 52-year-old male case of right trigeminal neurinoma at lateral cavernous sinus. The tumor was 40 mm in maximum diameter, obviously compressed temporal lobe and encased internal carotid artery. Extradural middle fossa and transcavernous approach was applied and the tumor was resected via Parkinson's triangle. This approach enabled safe and effective tumor resection, sufficient visualization, and operative field (Figs. 1 and 2). We performed dissection of the tumor from trigeminal nerve, tentorium, and middle fossa and resect the tumor around internal carotid artery sufficiently. Postoperative course was good without any new neurological deficit. This surgical method is considered safe and effective for the resection of the tumor at lateral cavernous sinus.

The link to the video can be found at: https://youtu.be/2ekuILIgEuo.
Comparative Evaluation of the Effect of Three Different Types of Pattern Materials on the Vertical Marginal Accuracy of Complete Cast Crown: An In Vitro Study
Authors: Sharma Preetica , Kalra Tarun , Kumar Manjit , Bansal Ajay , Malik Shefali Singh
Published: November 2021

Aim and Objective The main aim of this study was to evaluate the effect of three different types of pattern materials on the vertical marginal accuracy of complete cast crown.

Material and Methods Three groups of 20 specimens each were made based on three pattern materials, that is, blue inlay wax, autopolymerizing acrylic resin, and light cure pattern resin. Castings were made and examined using stereo microscope for vertical marginal discrepancy.

Results The result showed that the highest mean gap was noticed in the castings fabricated using inlay type B pattern wax followed by the castings fabricated using autopolymerizing resin and the least mean gap was observed in the castings fabricated using light cure modeling material.

Conclusion It was concluded from this study that the use of light cure modeling material to make patterns for casting with lost wax technique is best recommended than inlay type B pattern and autopolymerizing resin.
Evaluation of Tear Film Urea Level as a Diagnostic Marker of Dry Eye Disease: A Pilot Study
Authors: Velamakanni Gurunadh Satyanarayana , Sharma Anil , Batra Hitender S. , Velamakanni Subrahmanya Murti , Khan Mansur , Gupta Sandeep
Published: November 2021

Introduction Urea secreted in the sweat is important for skin moisture. Similarly, ocular surface moisture is maintained by the conjunctiva. Based on this, the level of urea in tear film can be used as a potential diagnostic test for dry eye disease (DED). One of the standard tests for DED is Schirmer's test (ST). The aim of this study was to compare tear film urea to values of ST.

Methods Fifty patients symptomatic for DED having ST ≤ 10 mm/5 min were enrolled in the study. Fifty age- and sex-matched asymptomatic subjects with ST > 10 mm/5 min were taken as controls. All patients were subjected to an estimation of tear film urea, collected using micropipettes, and analyzed by an Erba Chem 5 semi-autoanalyzer. Based on the ST reading as per the Dry Eye Workshop 2007 (DEWS) classification, dry eye was classified as dry eye (≤ 10 mm/5 min), severe dry eye (≤ 5 mm/5 min), and very severe dry eye (≤ 2 mm/5 min). Tear film urea values were compared with ST values that were considered standard. Statistical analysis was done using Medcalc version 19.7. A p-value ≤ 0.05 was considered significant.

Results The mean tear film urea levels in cases were (26.78 ± 5.70 mg/dL) significantly lower compared with controls (41.72 ± 6.86 mg/dL). The area under the receiver characteristic operator curve (AUC) for tear film urea in diagnosing DED was 0.936 (p < 0.0001) with a cutoff of ≤ 37.2 mg/dL, yielding a sensitivity of 96% and a specificity of 76%. For diagnosing severe DED, the AUC for tear film urea was 0.824 (p < 0.0001) with a cutoff value of ≤ 23.4 mg/dL, yielding a sensitivity of 60.8% and a specificity of 92.59%. For diagnosis of very severe DED, the AUC for tear film urea was 0.972 (p < 0.0001) with a cutoff value of ≤ 19.8 mg/dL, yielding a sensitivity of 100% and a specificity of 93.62%. On comparing ST values to tear film urea, the regression coefficient was 0.85 (p < 0.0001), suggesting a linear relationship between ST and tear film urea.

Conclusion The study demonstrates that tear film urea can be a potential diagnostic marker for DED. The study also indicates that tear film urea level is linearly related to Schirmer's test values and provides an approximate diagnostic cutoff level for the design of future large-scale studies.
Putting qualitative international business research in context(s)
Authors: Reuber A. Rebecca , Fischer Eileen
Published: November 2021

The Welch et al. (J Int Bus Stud 42(5):740–762, 2011) JIBS Decade Award-winning article highlights the importance of the contextualization of international business research that is based on qualitative research methods. In this commentary, we build on their foundation and develop further the role of contextualization, in terms of the international business phenomena under study, contemporaneous conversations about qualitative research methods, and the situatedness of individual papers within the broader research process. Our remarks are largely targeted to authors submitting international business papers based on qualitative research, and to the gatekeepers – editors and reviewers – assessing them, and we provide some guidance with respect to these three dimensions of context.
The political-economy of land acquisition and privatization of Birr and Ayehu Farms in Amhara Region, North-West Ethiopia
Authors: Alamineh Asabu Sewenet , Workie Getachew Fentahun , Moges Nurlign Birhan
Published: November 2021

The recognition of commercial agricultural investment led to the expansion of large-scale farms through eviction of farmers during the Derg and Ethiopian People Revolutionary Democratic Front (EPRDF) regimes. But anti-dispossession voices and investment driven violence have frequently occurred in post-Derg Ethiopia. This study thus attempts to uncover the political-economy of land acquisition and privatization of Birr and Ayehu farms. The necessary data for the study were collected through interview, questionnaire, focused group discussion and document review. The data collected through questionnaire was analyzed using descriptive statistics and the qualitative data was analyzed thematically. The findings of the study indicated that the farms were began during the Derg regime as public enterprises, and later privatized to Ethio-Agri-CEFT in a neo-patrimonial modality with a gigantic trend of land acquisition, legal distortion and violation of landholding rights. This poor and neo-patrimonial operation of farms jeopardized local livelihoods, created land use change and evoked stiff public grievance, political upheaval and polarized state–society relations. This indicated that the expansion of farms have brought lopsided development to party affiliated investors by dismantling local livelihoods. Ethio Agri-CEFT thus should respect legal frameworks and adopt inclusive developmental practices for its sustainability and success.