bluuebunny/crossref_metadata_2025 huggingface dataset:
Процес дроселювання в соплових апаратах з поворотними діафрагмами
Authors: Zhyrkov Оleksandr , Usaty Оleksandr , Avdieieva Olena , Torba Yuriy
Published: August 2022

In the process of developing a method for numerically investigating a plane flow around a nozzle array with a rotary diaphragm, calculations were performed for various degrees of opening of the rotary diaphragm δ and pressure drops π on the array. The article presents some results of a numerical study of the flow in the nozzle channel at the degree of opening of the rotary diaphragm δ = (1…0.15). Modeling and calculations of the flow of the working fluid were performed using the Fluent software package. The construction of computational areas, limited by one inter-blade channel, for a different degree of opening of the diaphragm of the nozzle apparatus has been carried out. The grids for the computational domains were constructed. Calculations were carried out for δ = (1…0.15) and for various degrees of pressure drop across the grate. Because of the performed calculations, flow patterns in the interblade channel and behind it, and the distribution of kinetic energy loss coefficients along the grating front at various degrees of aperture opening at the nozzle inlet, were obtained. Based on the results of the work carried out, the following conclusions can be drawn: the operation of a nozzle array with a rotary diaphragm at different degrees of opening of the rotary diaphragm δ and pressure drops π on the grate can be divided in the range of opening steps δ = (1…0.77) as operation in the nozzle mode, and in the range δ = (0.77…0.15) as in throttle mode; when the angle of attack changes, the values of the kinetic energy loss coefficients increase significantly (up to 25 %) only for π = 0.7 and δ = 1; at π = 0.3 and δ = 1, the coefficient increases slightly (up to 0.5 %); at π = 0.7; 0.3 and δ = 0.3, the coefficient increases to 5 %, while the coefficient ζі changes less relative to the coefficient ζ90 at the calculated angle of attack α0 = 90 grids). The results obtained in this work will be used to develop a technique for numerically investigating the spatial flow around nozzle arrays with rotary diaphragms.
Аналіз впливу кривизни S-подібного каналу та умов польоту на ефективність ковшового вхідного пристрою
Authors: Zhornik Oleg , Kravchenko Ihor , Mitrakhovych Mykhailo , Balalaieva Ekaterina
Published: August 2022

When creating a modern aircraft, the principle of optimal integration of the power plant and the aircraft is used to ensure the maximum target function, determined by its functional purpose. The specific fuel consumption and specific thrust of the power plant depend significantly on the loss of the total air pressure in the inlet device, which is characterized by the total recovery factor. The change in pressure along the diameter of the propfan affects the efficiency of the inlet of the power plant. When using the inlet ring device, its efficiency decreases, due to low pressure in the area of the root part of the propfan blades. The use of a bucket inlet allows air to be supplied to the channel from the area located near the middle part of the blade height and this is the main factor influencing the reduction of pressure losses in the air supply channel. When using a bucket inlet, curvature and constriction are important factors influencing the effectiveness of S-channels. The influence of the curvature of the S-shaped channel on the total pressure recovery coefficient at a constant value of its narrowing is studied in this work. The study S-shaped channel in its geometric parameters is equivalent to the channel of the annular inlet device of a power plant with a turbofan engine. The total pressure recovery coefficient of an S-shaped channel is calculated from the flow parameters in the sections of the S-shaped channel by solving the Navier-Stokes equations using the Florian Menter two-layer turbulence model (SST Transitional No. 4 Gamma Theta) and the combined finite element model at the entrance to the channel and in the channel itself - hexahedral, at the exit tetrahedral. An analysis of the dependence of the total pressure recovery coefficient of the S-shaped channel on the M number and the channel curvature shows that, up to a curvature of 0.002, the total pressure recovery coefficient is not significantly affected. A further increase in the channel curvature has a significant effect on the change in the total pressure recovery coefficient, which is associated with flow separation and losses from the vortex formation.
Аналіз роботи гідростатичного підшипника на перехідних режимах
Authors: Nazin Volodymyr
Published: August 2022

The design of reliable rotor supports for modern high-speed machines is associated with the solution of many complex problems, both theoretical and experimental. Experimental studies play an important role in the system of scientific research and allow improvement and refine mathematical models and the application of numerical methods for their implementation. Experimental studies are usually selective and therefore require careful preparation. The task was set to investigate the characteristics of a hydrostatic bearing in the starting and braking modes. A program of experimental studies of the behavior of a shaft on hydrostatic bearings for the most difficult operating conditions has been developed. The advantages of hydrostatic bearings are given compared with other types of plain bearings, as well as compared with rolling bearings. The effectiveness of hydrostatic bearings is shown, compared with other types of bearings, for modern high-speed machines, in which there is an increase in vibration overloads and vibration displacements. Hydrostatic bearings have proven themselves in all operating modes, including transient ones. A description of the experimental setup for the study of transient modes of operation of the shaft on hydrostatic bearings is given. Studies of the transient modes of operation of the shaft on hydrostatic bearings were conducted at various values of the pressure of the working fluid supply, residual unbalance, as well as various values of the diameter of the hydrostatic bearing. To identify the movement of the rotor on hydrostatic bearings, the values of the amplitudes of oscillations during stationary (steady) movement of the rotor are also presented. It is shown that the comparison of the oscillation amplitudes of the rotor on hydrostatic bearings with a diameter of 0.06 m for the cases of non-stationary and stationary modes of its operation during the acceleration of the amplitude of oscillations in the entire range of rotational speeds is slightly lower (by about 15…20 %) than in the case of a stationary mode of operation of the rotor. When the rotor slows down, the amplitude of the rotor oscillations at high speeds is somewhat larger (by about 7…9 %), and at low speeds it is less by 8…10 % than in the case of a stationary rotor operation. The small influence of the non-stationary nature of the rotor movement on the dynamic characteristics can be explained by its large mass.
Connecting Past and Present Pieces: Contemporary African Digital Collage with European Colonial Experience
Authors:   United European Research Society, PARK Jaeyeon
Published: August 2022

Africa's 'digitalization' is now a clear social, economic, and cultural phenomenon. Digital culture permeates the daily lives of many Africans and connects Africa to other regions in a way that has never been before. How are contemporary African artists changing the existing story? They are not only experimenting with digital technology, but also creating new images that project space between the past and the present, analog and digital, pre-colonial and post-colonial reality. By shortening complex perceptions to moments, overlapping reality and unreality, and reorganizing landscapes and history through multiple spatial implementations, digital collages build a world closer to neutral than concrete actions.
The artists want to use digital collage to remind their values that have faded in the long history of oppression and to volatilize negatives about black culture. Through this act, the concept of modern 'memory represented by the past' is dismantled, disappeared, and the past as a dead time is revived. Another characteristic of contemporary African digital collage is that it rejects fixed identity and tries to expand it in an irregular and distracting way. By combining broken symbols through contradictory mixed styles, contemporary african digital collage that contain metaphors for deviation overthrow tradition. It aims to overturn the image of the colony through the process of "African remix," which consists of multiple images containing complex contexts of self-sustaining memories and overlapping memories that cannot be defined in language.
OPTIMASI RUTE SALES COVERAGE MENGGUNAKAN ALGORITMA CHEAPEST INSERTION HEURISTIC DAN LAYANAN GOOGLE MAPS API
Authors: Yulianto Erwin , Setiawan Awan
Published: August 2022

Traveling Salesman Problem (TSP) is one of the distribution issues which is long discussed in the optimization review, where the review problem is how a salesman visits the entire travel route within the coverage area and returns to the starting point of departure with the rule that no destination should be visited more than once. PT. Panjunan is a company engaged in the products distribution of various principles. Currently the managing process of customer location data at the company is still not maximal due to the absence of calculations in every daily visit routes so it impact on the effectiveness of time. In addition, the absence of visualization of real customer data on the field leads to the error distribution and marketing of goods which is uneven, not on target and impact on the decline in sales value. One of the techniques used to accelerate the search solutions of TSP problems is to use an insertion algorithm, or also called the Cheapest Insertion Heuristic (CIH) algorithm. The discussion of this research is to study and apply CIH algorithm in determining the optimization of daily sales traffic route with the aim of this research is to make daily trip route optimization program by applying Cheapest Insertion Heuristics algorithm and provide real customer data visualization on original map in the field as analysis material for operational team and management by utilizing Google Maps API service. System development method used in this research using waterfall model with implementation tools is laravel framework and mySQL as DBMS.
Sistem Informasi Akademik Berbasis Website untuk Meningkatkan Prestasi Belajar Siswa MAN 3 Cirebon di Masa Pandemi Covid-19
Authors: Septian Nanda , Suarna Nana , Rizki Amalia Dita
Published: August 2022

Parents need information about children's activities and learning outcomes in school. Academic information system is one way that information about the results of learning activities can be delivered more easily and quickly by the school and can be well received by parents as guardians of students. Therefore, an academic information system is designed that is able to provide information about student learning outcomes and activities so that parents can still supervise learning activities in schools. The system is expected to be able to be a material for evaluating children on the results of their learning in school so that children are able to become outstanding students. The purpose of this study is so that parents can find out the results of children's learning, namely grades and other learning activities in school. This research uses a qualitative approach where data collection is obtained from interviews, observations, and documentation. In addition, this system is designed using the waterfall method with stages of analysis, design or design, implementation, verification, and maintenance. The result of the research is the application of a web-based academic information system capable of being a means of parental supervision of the results of children's learning activities so that it has an impact on increasing student achievement.
El letrado y la ciudad en la modernidad latinoamericana: una lectura político-crítica de la ciudad letrada de Ángel Rama
Authors: Cápona González Daniela , Pérez Diaz Pedro
Published: August 2022

En el presente artículo se evidencia la vinculación que establece Rama entre lengua/literatura y espacio/poder en La ciudad letrada. Este nuevo paradigma ha permitido pensar y repensar la literatura latinoamericana y los estudios culturales, sin embargo, entraña contradicciones dentro del mismo pensamiento del uruguayo. La tajante división que el autor establece entre ciudad real y ciudad letrada hace imposible pensar el rol de la literatura fuera de la esfera del poder institucional, al mismo tiempo que relega ontológicamente la realidad de esta última a una meramente instrumental. Nuestra propuesta es leer a la luz del concepto de transculturación esta oposición, para establecer una dialéctica que permita considerar la politicidad propia de la ciudad real y su rol activo en la expresión de una literatura de resistencia política.
La sinrazón de lo imperativo: Macario de Juan Rulfo
Authors: Torres Vergel Frak
Published: August 2022

El artículo explica el funcionamiento del discurso dominante y su sistema de referencias en Macario (El llano en llamas, 1953) de Juan Rulfo (1917-1986). Se propone una lectura del cuento en tanto alegoría de la dominación de una dictadura y del estado de alienación sufrido por el pueblo mexicano durante el período inmediatamente anterior a la Revolución mexicana (1910). Para conseguir tal propósito, se analiza ampliamente el estatus sociosemiótico del sujeto hablante y la red de convergencia de los signos que lo definen. Se logra así poner de relieve una precisa codificación de las elaboraciones sociales en la estructura discursiva, que permea la percepción desplegada por la figura del sujeto de la enunciación.
Театральная школа Bolshoi в Рио-де-Жанейро: интеграция искусства, образования и архитектуры
Authors: Santos Vanessa Lessa Fraga dos , Salgado Mônica Santos
Published: August 2022

Настоящий проект является результатом размышлений о таких темах, как классический балет, искусство, традиционное обучение в Бразилия и архитектура, о том, как каждая из них связана и как вставить их в композицию архитектурного проекта, представленного в качестве требования для получения степень Факультета Архитектуры и Градостроительства UFRJ. Искалась концепция, которая могла бы объединить все дизайнерские замыслы и сделать соотношение между искусством классического балета, искусством архитектуры и программой потребностей предприятия. Искусство дизайна не должно просто следовать жестким образцам, параметрам и формам, и в этом контексте мы стремились разработать плавную, легкую архитектуру, которая имела бы характеристики искусства и классического балет. Для этого было проверено, как тело танцора выполняет балетные па и как ось этого тела позволяет движениям и плавности па в хореографии. При реализация проекта нет «правильных или неправильных», необходимо учитывать руководящие принципы, потребности и спецификации для каждого общественного, физического пространства или местной культуры. Проект Escola do Ballet Bolshoi в Рио-де-Жанейро добавляет знания в области танца, предлагая практические и теоретические занятия по балету, джазу, современным танцам, фламенко, чечетке и народным танцам к обучению в средней школе, проводимому в Бразилия. Студенты изучают видео и музыкальные техники, а также проходят практические и теоретические музыкальные занятия, что еще больше расширяет их танцевальную подготовку, делая их более совершенными танцорами.
Pembuatan Briket sebagai Salah Satu Upaya Pemanfaatan Limbah Pertanian Bonggol Jagung di Desa Tampingmojo
Authors: Faizah Mazidatul , Rizky Achmad , Zamroni Ahmad , Khasan Umar
Published: August 2022

Limbah adalah buangan yang dihasilkan dari suatu proses produksi baik industri maupun domestik. Desa Tampingmojo Tambelang Jombang memiliki area persawahan yang ditanami jagung. Dengan banyaknya persawahan yang menanam pohon jagung, bisa dipastikan bahwa limbah pertanian berupa bonggol jagung yang dihasilkan juga akan banyak. Briket merupakan padatan berpori yang mengandung karbon yang dihasilkan dari bahan-bahan yang mengandung karbon dengan pemanasan pada suhu tinggi. Tujuan dibuatnya briket dari bonggol jagung adalah untuk mengurangi limbah pertanian berupa bonggol jagung sehingga limbah bonggol jagung yang terbuang dapat terkurangi dengan dibuatnya briket bonggol jagung.
Percepção sobre a dinâmica do jogo InterRaps com estudantes de cursos de graduação da saúde
Authors: Souza Maria Gabriela Rodrigues , Lourenço Rafaela Gessner , Santos Danyelle Leonette Araújo , Heiden Nicolle Boell , Sabino Martha Porto
Published: August 2022

Este estudo objetiva analisar a percepção de estudantes de cursos de graduação da saúde sobre a dinâmica do jogo InterRaps, identificando os seus limites e suas potencialidades. O jogo oferece uma imersão digital simulada da experiência de trabalho interprofissional nos equipamentos de saúde da Rede de Atenção Psicossocial. Estudo qualitativo, exploratório e descritivo. A coleta de dados ocorreu entre fevereiro e abril de 2021, durante quatro partidas do jogo InterRaps, com a participação de nove estudantes da área da saúde de uma universidade do sul do Brasil. Os dados foram submetidos à análise de conteúdo, com o apoio do Software MaxQDA. Os resultados apontaram reflexões acerca da dinâmica do jogo, jogabilidade, interprofissionalidade e do uso de plataformas online para o ensino remoto durante a pandemia de COVID-19. Constatou-se que o jogo se apresenta como alternativa para o ensino remoto, pois utiliza a metodologia ativa de gamificação do ensino na perspectiva da interprofissionalidade.
What is the Cost of Silence: Examining the Drawbacks of the In-class Participation Grading Method in American K-12 Schools
Authors: Zhou Ricky
Published: August 2022

This study weighs the significance of one of the commonly used grading methods in K-12 schools in a new way: the in-class participation grading method, which measures a student’s quantitative engagement in classes. The participation grade is often combined with other gradings and makes up the Grade Point Average (mostly in high schools). Yet numerous flaws exist within the grading system. While it is used worldwide, only K-12 schools in the United States will be considered in this paper. The objective is to determine whether the grading method is inclusive or, in other words, fair to be used in the American education system. The essay examines and discusses the drawbacks of the method and provides plausible alternatives. Such alternatives to grading participation might shed light on innovating the American Education System in general. Though no experimental procedures were conducted, this literary analysis utilizes multiple sources for empirical evidence.
The Impact of Commute on Students’ Performance
Authors: Jamil Dawood , Rayyan Mohammed , Abdulla Hameed Ahmed Khalifa , Masood Fatima , Javed Palwasha , Sreejith Anusha
Published: August 2022

This study aimed to assess the prevalence of commuters in Gulf Medical University (GMU), the impact of length of commute on student's health, and the association between length of commute and academic performance. We conducted a cross-sectional study at Gulf Medical University in the Summer of 2018. It included students 18 years of age and above, regardless of gender, nationality, and year of study, enrolled across the various GMU programs, including Medicine, Dentistry, Basic Medical Science, Physical Therapy, Health Science, Nursing, and Pharmacy. Four hundred and twenty students actively participated in our self-administered questionnaire. Our study determined statistically significant associations between commute and a variety of factors such as physical difficulties, stress, the prevalence of accidents, sleep schedule, etc. Our study concluded that students having longer commutes experienced significant physical difficulties, higher levels of stress, and an increased risk of accidents. Furthermore, we found that students with increased commute times also seemed to lose sleep more frequently than those with shorter commute times. In addition, our study established that commute harms academic performance, as students who commuted for extended periods were shown to have decreased academic performance in addition to having less time to study.
A DISCOURSE ANALYSIS ON STUDENTS SKILL IN INTERPRETING ENGLISH SENTENCES INTO INDONESIAN IN ENGLISH INTERPRETATION CLASS DURING COVID-19 PANDEMICS
Authors: Dina Mela , Sparingga Myke Fitria
Published: August 2022

The purpose of this research was to know about the students’ difficulties in interpreting English sentences into Indonesia in English Interpretation Class. The type of this research was qualitative research which was the case study to 8 students as the informants. They had been chosen by using purposive sampling. The data were collected by seeing the interview guided. After collecting the data, the validity of the data was tested by using prolonged engagement. Then, it was analyzed by reducing, displaying, verifying, and drawing the conclusion. Based on the result of the research, it can be concluded that there some difficulties found by the students in interpreting English sentences into Indonesian. They are: 1) Being difficult to adjust the meaning of a word with the sentence, 2) Being difficult to find a word in the dictionary, 3) Having lack of vocabulary, 4) Having lack of practice, 5) Time Pressure that contributes to nervousness, 6) Being difficult to read faster the slide show, 7) Having lack of signal, 8) Tending to translate word by word.
In/Visible Finnishness: Representations of Finnishness and Whiteness in the Sweden-Finnish Social Media Landscape
Authors: Liimatainen Tuire
Published: August 2022

This chapter examines embodied representations of Finnishness and whiteness in Sweden where the collective notion of Sweden-Finnishness is situated in the nexus migrant and minority experiences. Based on material generated by individuals and activists as part of Sweden-Finnish social media campaigns in the 2010s, the chapter discusses the different ways in which Finnishness and whiteness are negotiated on an individual level and how they are situated in different social, political and historical contexts. By applying the analytical lens of in/visibility and drawing from both critical whiteness studies and intersectionally informed thinking, the study reveals how Finnishness can at the same time be invisible and visible due to the whiteness of the Finns, but also visible as minoritized and racialized others. The chapter provides novel insights into contemporary Sweden-Finnishness and experiences of non-white Sweden-Finns, as well as politicized and minoritized Sweden-Finnishness. In addition to highlighting the diversity of different Finnish experiences in Sweden, the study demonstrates that whiteness is a highly fluid, situational and contextual way of boundary-drawing.
Maternal mortality and its risk factors in Africa: A systematic review and meta-analysis
Authors: Kolleh Edwina M , Bestman Prince L , Bajinka Ousman , Weamie Sonkarlay JY , Luo Jiayou
Published: August 2022

Background: Maternal mortality is a significant global health problem, which affects women of reproductive age. Maternal mortality is especially high in Africa, where more women die during pregnancy and childbirths from preventable causes. This review therefore aim to assess maternal mortality ratio and identify its risk factors. Methods: PubMed, Web of science, Embase, and Medline were searched for cohort, casecotrol and cross-sectonal studies published between 2008 and 2021that assessed maternal mortality or its risk risk in Africa, or among African women. The preferred reporting items for a systematic review and meta-analysis was carefully considered while conducting this review. Random effect model was used to generate pooled estimates. Data were analyzed using StataCorp version 16.0 statistical software. Results: A total of 1,657 articles were retrieved from searching four electronic databases. The sum of 1,639 records were excluded and a total of 18 studies were included into the the systematic review and meta-analysis. Using a random effect approach, this systematic review and meta-analysis estimated the MMR of 496/100,000 for Africa. Further, maternal age ≥ 35 years [OR = 2.50; 95% CI: (1.50, 4.15)], no formal education/illiterate mother [OR = 2.30; 95% CI: (1.50, 3.52)], no history of ANC attendance [OR = 2.42; 95% CI: (0.43, 13.50)], pregnancy complication/previous pregnancy-related illness [OR = 4.47; 95% CI: (3.03, 6.60)], delayed in seeking health care [OR = 5.12; 95% CI: (3.14, 8.34)], mother being referred [OR= 5.60; 95% CI: (4.16, 7.54)], and husband's education (illiterate/primary) [OR = 1.32; 95% CI: (0.69, 2.53)] were identified as risk factors of maternal mortality. Conclusion: A high MMR of 496/100,000 live birth for Africa was estimate in this review. Also, several risk factors of maternal mortality were identified. Healthcare professionals are therefore reminded to regularly educate mothers about the risk and benefits of seeking early prenatal healthcare
A classification of the main psychiatric disorders in the perinatal period
Authors: Moretti Patrizia , Brufani Francesca , Falsini Cecilia , Menculini Giulia , Tortorella Alfonso
Published: August 2022

This work aim is to classify main psychiatric disorders in the perinatal period to the present day, highlighting their main nosographic characteristics. Moreover to show the problem of mental health during pregnancy and repercussions on the current social network, on the organizational health network and on global health.
The role of private military companies in the light of International Humanitarian Law (IHL)
Authors: Sakib S M Nazmuz
Published: August 2022

In this research paper it has been explained how the changing nature of conflict has encouraged the private military companies to participate in the state affairs. The mercenaries that have existed almost for centuries have started to operate in a more systematic manner now. It is argued in this indenture what Machiavelli had suggested a long while ago. The mercenaries can help you with the short term gains but they cannot win you wars. It is explained how the mercenaries are not bound by any moral obligation. They are often found involved in human rights violations. An attempt has been made to understand the utility of mercenaries in the light of International Humanitarian Law (IHL). The knowledge of IHL is important to analyze how the private militaries can be held accountable by Law.
Molecular basis for pericyte-induced capillary tube network assembly and maturation
Authors: Kemp Scott S. , Lin Prisca K. , Sun Zheying , Castaño Maria A. , Yrigoin Ksenia , Penn Marlena R. , Davis George E.
Published: August 2022

Here we address the functional importance and role of pericytes in capillary tube network assembly, an essential process that is required for vascularized tissue development, maintenance, and health. Healthy capillaries may be directly capable of suppressing human disease. Considerable advances have occurred in our understanding of the molecular and signaling requirements controlling EC lumen and tube formation in 3D extracellular matrices. A combination of SCF, IL-3, SDF-1α, FGF-2 and insulin (“Factors”) in conjunction with integrin- and MT1-MMP-induced signaling are required for EC sprouting behavior and tube formation under serum-free defined conditions. Pericyte recruitment to the abluminal EC tube surface results in elongated and narrow tube diameters and deposition of the vascular basement membrane. In contrast, EC tubes in the absence of pericytes continue to widen and shorten over time and fail to deposit basement membranes. Pericyte invasion, recruitment and proliferation in 3D matrices requires the presence of ECs. A detailed analysis identified that EC-derived PDGF-BB, PDGF-DD, ET-1, HB-EGF, and TGFβ1 are necessary for pericyte recruitment, proliferation, and basement membrane deposition. Blockade of these individual factors causes significant pericyte inhibition, but combined blockade profoundly interferes with these events, resulting in markedly widened EC tubes without basement membranes, like when pericytes are absent.
Thioester deprotection using a biomimetic NCL approach
Authors: Villamil Valentina , Saiz Cecilia , Mahler Graciela
Published: August 2022

The reversibility of the thiol-thioester linkage has been broadly employed in many fields of biochemistry (lipid synthesis) and chemistry (dynamic combinatorial chemistry and material science). When the transthioesterification is followed by a S-to-N acyl transfer to give an amide bond, it is called Native Chemical Ligation (NCL), a high-yield chemoselective process used for peptide synthesis. Recently, we described thioglycolic acid (TGA) as a useful reagent for thioester deprotection both in solution and anchored to a solid-support under mild conditions. Inspired by NCL, in this work, we extended this approach and explored the use of 2-aminothiols for the deprotection of thiols bearing an acyl group. The best results were obtained using cysteamine or L-cysteine in an aqueous buffer pH 8 at room temperature for 30 min. The described approach was useful for S-acetyl, S-butyryl, and S-benzoyl heterocycles deprotection with yields up to 84%. Employing this methodology, we prepared six new analogs 2 of mercaptomethyl bisthiazolidine 1, a useful inhibitor of a wide-range of Metallo-β-Lactamases (MBLs). Compared with the previous methodologies (TGA polymer supported and TGA in solution), the biomimetic deprotection herein described presents better performance with higher yields, shorter reaction times, less time-consuming operations, easier setup, and lower costs.
Multifunctional exosomes derived from bone marrow stem cells for fulfilled osseointegration
Authors: Zhuang Jingwen , Hang Ruiyue , Sun Ruoyue , Ding Yanshu , Yao Xiaohong , Hang Ruiqiang , Sun Hui , Bai Long
Published: August 2022

Bone marrow mesenchymal stem cells (BMSCs) have self-renewal, multi-directional differentiation potential, and immune regulation function and are widely used for de novo bone formation. However, the wide variation in individual amplification, the potential risk of cancer cell contamination, and the need for culture time significantly limit their widespread use clinically. Alternatively, numerous studies have shown that exosomes secreted by BMSCs in the nanoscale can also affect the functionality of endothelial cells (angiogenesis), macrophages (immunomodulation), and osteoblasts/osteoclasts (osteogenesis), which is a highly promising therapy for osseointegration with pronounced advantages (e.g., safety, high efficiency, and no ethical restrictions). The review aims to summarize the multifaceted effect of BMSCs-derived exosomes on osseointegration and provide reference and basis for rapid and qualified osseointegration.
Novel high strength PVA/soy protein isolate composite hydrogels and their properties
Authors: Zhao Yanteng , Jin Lu , Liu Xin , Liu Xue , Dong Shuling , Chen Yun , Li Xianyu , Lv Xianping , He Meng
Published: August 2022

High strength polyvinyl alcohol (PVA)/soy protein isolate (SPI) composite hydrogels (EPSG) were constructed by the introduction of PVA into SPI through the crosslinking with epichlorohydrin (ECH) and a freezing-thawing process. The EPSG hydrogels were characterized by scanning electron microscopy, FTIR, X-ray diffraction and compressive test. The results revealed that chemical crosslinking interactions occurred for SPI and PVA during the fabrication process. The composite hydrogels exhibited a homogenous porous structure, indicating certain miscibility between PVA and SPI. The introduction of PVA increased the compressive strength of SPI hydrogels greatly, which could reach as high as 5.38 MPa with the water content ratio of 89.5%. Moreover, the water uptake ratio of completely dried SPI hydrogel (namely xerogel) decreased gradually from 327.4% to 148.1% with the incorporation of PVA, showing a better potential as implants. The cytocompatibility and hemocompatibility of the EPSG hydrogels were evaluated by a series of in vitro experiments. The results showed that the EPSG hydrogels had no cytotoxicity (cell viability values were above 86.7%), good biocompatibility and hemocompatibility, showing potential applications as a direct blood contact material in the field of tissue engineering.
In silico investigation and potential therapeutic approaches of natural products for COVID-19: Computer-aided drug design perspective
Authors: Rahman Md. Mominur , Islam Md. Rezaul , Akash Shopnil , Mim Sadia Afsana , Rahaman Md. Saidur , Emran Talha Bin , Akkol Esra Küpeli , Sharma Rohit , Alhumaydhi Fahad A. , Sweilam Sherouk Hussein , Hossain Md. Emon , Ray Tanmay Kumar , Sultana Sharifa , Ahmed Muniruddin , Sobarzo-Sánchez Eduardo , Wilairatana Polrat
Published: August 2022

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a substantial number of deaths around the world, making it a serious and pressing public health hazard. Phytochemicals could thus provide a rich source of potent and safer anti-SARS-CoV-2 drugs. The absence of approved treatments or vaccinations continues to be an issue, forcing the creation of new medicines. Computer-aided drug design has helped to speed up the drug research and development process by decreasing costs and time. Natural compounds like terpenoids, alkaloids, polyphenols, and flavonoid derivatives have a perfect impact against viral replication and facilitate future studies in novel drug discovery. This would be more effective if collaboration took place between governments, researchers, clinicians, and traditional medicine practitioners’ safe and effective therapeutic research. Through a computational approach, this study aims to contribute to the development of effective treatment methods by examining the mechanisms relating to the binding and subsequent inhibition of SARS-CoV-2 ribonucleic acid (RNA)-dependent RNA polymerase (RdRp). Thein silicomethod has also been employed to determine the most effective drug among the mentioned compound and their aquatic, nonaquatic, and pharmacokinetics’ data have been analyzed. The highest binding energy has been reported -11.4 kcal/mol against SARS-CoV-2 main protease (7MBG) in L05. Besides, all the ligands are non-carcinogenic, excluding L04, and have good water solubility and no AMES toxicity. The discovery of preclinical drug candidate molecules and the structural elucidation of pharmacological therapeutic targets have expedited both structure-based and ligand-based drug design. This review article will assist physicians and researchers in realizing the enormous potential of computer-aided drug design in the design and discovery of therapeutic molecules, and hence in the treatment of deadly diseases.
Seroepidemiological surveillance, community perceptions and associated risk factors of malaria exposure among forest-goers in Northeastern Thailand
Authors: Rahim Mohd Amirul Fitri A. , Chuangchaiya Sriwipa , Chanpum Paisit , Palawong Laun , Kantee Panuwat , Dian Nor Diyana , Lubis Inke Nadia D. , Divis Paul C. S. , Kaneko Akira , Tetteh Kevin K. A. , Idris Zulkarnain Md
Published: August 2022

Malaria remains a major public health challenge in Thailand. Continuous assessment and understanding of the behavior and perceptions related to malaria exposure in the high-risk group are necessary to achieve the elimination goal. This study aimed to investigate the parasite prevalence, seroprevalence rate, knowledge, attitudes, and practices (KAP), and malaria risk factors in rural communities living close to a forested area in the northeastern part of Thailand. A community-based cross-sectional survey was conducted in three forest-goer communities (i.e., Ban Khok, Ban Koh, and Dong Yang) located in Khamcha-i district, Mukdahan Province, Thailand, from July to August 2019. Demographic, socioeconomic information and KAP data were collected using a structured questionnaire. Parasite prevalence was determined by microscopy. Seroprevalence was determined via ELISA using two Plasmodium falciparum (PfAMA-1 and PfMSP-119) and two Plasmodium vivax (PvAMA-1 and PvMSP-119) antigens. Age-adjusted antibody responses were analyzed using a reversible catalytic model to calculate seroconversion rate (SCR). Malaria parasite was not detected in any of the 345 participants. The overall malaria seroprevalence was 72.2% for PfAMA-1, 18.8% for PfMSP-119, 32.5% for PvAMA-1, and 4.4% for PvMSP-119. The proportion of seroprevalence for P. falciparum and P. vivax antigens was significantly highest in Ban Koh (35.1%, P < 0.001) and Don Yang (18.8%, P < 0.001), respectively. For all parasite antigens except PvMSP-119, the proportion of seropositive individuals significantly increased with age (P < 0.001). Based on the SCRs, there was a higher level of P. falciparum transmission than P. vivax. Regarding KAP, almost all respondents showed adequate knowledge and awareness about malaria. Nevertheless, significant effort is needed to improve positive attitudes and practices concerning malaria prevention measures. Multivariate regression analyses showed that living in Ban Koh was associated with both P. falciparum (adjusted odds ratio [aOR] 12.87, P < 0.001) and P. vivax (aOR 9.78, P < 0.001) seropositivities. We also found significant associations between age and seropositivity against P. falciparum and P. vivax antigens. The data suggest that seroepidemiological surveillance using AMA-1 and MSP-119 antigens may provide further evidence to reconstruct malaria exposure history. The absence of weak evidence of recent malaria transmission in Mukdahan Province is promising in the context of the disease elimination program.
Safety and Efficacy of Stereotactic Arrhythmia Radioablation for the Treatment of Ventricular Tachycardia: A Systematic Review
Authors: Volpato Giovanni , Compagnucci Paolo , Cipolletta Laura , Parisi Quintino , Valeri Yari , Carboni Laura , Giovagnoni Andrea , Dello Russo Antonio , Casella Michela
Published: August 2022

Catheter ablation (CA) is a fundamental therapeutic option for the treatment of recurrent ventricular arrhythmias. Notwithstanding the tremendous improvements in the available technology and the increasing amount of evidence in support of CA, in some patients the procedure fails, or is absolutely contraindicated due to technical or clinical issues. In these cases, the clinical management of patients is highly challenging, and mainly involves antiarrhythmic drugs escalation. Over the last 5 years, stereotactic arrhythmia radioablation (STAR) has been introduced into clinical practice, with several small studies reporting favorable arrhythmia-free outcomes, without severe side effects at a short to mid-term follow-up. In the present systematic review, we provide an overview of the available studies on stereotactic arrhythmia radioablation, by describing the potential indications and technical aspects of this promising therapy.
Investigation of the protective mechanism of leonurine against acute myocardial ischemia by an integrated metabolomics and network pharmacology strategy
Authors: Rong Weiwei , Li Jiejia , Wang Lifeng , Luo Shanshan , Liang Tulu , Qian Xunjia , Zhang Xiaodan , Zhou Qinbei , Zhu Yizhun , Zhu Qing
Published: August 2022

Background

Leonurus japonicus Houtt has an obvious efficacy on cardiovascular diseases. As the most representative component in the herb, leonurine has attracted increasing attention for its potential in myocardial ischemia. However, its protective mechanism against myocardial ischemia remains incompletely elucidated.

Objectives

The present study aimed to reveal the potential mechanism of leonurine in acute myocardial ischemia using a strategy combining metabolomics and network pharmacology.

Methods

First, a metabolomics method was proposed to identify the differential metabolites of plasma in rats. Then, network pharmacology was performed to screen candidate targets of leonurine against acute myocardial ischemia. A compound-reaction-enzyme-gene network was thus constructed with the differential metabolites and targets. Finally, molecular docking was carried out to predict the binding capability of leonurine with key targets.

Results

A total of 32 differential metabolites were identified in rat plasma, and 16 hub genes were detected through network pharmacology. According to the results of compound-reaction-enzyme-gene network and molecular docking, what was screened included six key targets (GSR, CYP2C9, BCHE, GSTP1, TGM2, and PLA2G2A) and seven differential metabolites (glycerylphosphorylcholine, lysophosphatidylcholine, choline phosphate, linoleic acid, 13-HpODE, tryptophan and glutamate) with four important metabolic pathways involved: glycerophospholopid metabolism, linoleic acid metabolism, tryptophan metabolism and glutamate metabolism. Among them, glycerophospholipid and tryptophan metabolism were shown to be important, since the regulation of leonurine on these two pathways was also observed in our previous metabolomics study conducted on clinical hyperlipidemia patients.

Conclusion

This is the first study of its kind to reveal the underlying mechanism of leonurine against acute myocardial ischemia through a strategy combining metabolomics and network pharmacology, which provides a valuable reference for the research on its future application.
Performance of a deep learning tool to detect missed aortic dilatation in a large chest CT cohort
Authors: Pradella Maurice , Achermann Rita , Sperl Jonathan I. , Kärgel Rainer , Rapaka Saikiran , Cyriac Joshy , Yang Shan , Sommer Gregor , Stieltjes Bram , Bremerich Jens , Brantner Philipp , Sauter Alexander W.
Published: August 2022

Purpose

Thoracic aortic (TA) dilatation (TAD) is a risk factor for acute aortic syndrome and must therefore be reported in every CT report. However, the complex anatomy of the thoracic aorta impedes TAD detection. We investigated the performance of a deep learning (DL) prototype as a secondary reading tool built to measure TA diameters in a large-scale cohort.

Material and methods

Consecutive contrast-enhanced (CE) and non-CE chest CT exams with “normal” TA diameters according to their radiology reports were included. The DL-prototype (AIRad, Siemens Healthineers, Germany) measured the TA at nine locations according to AHA guidelines. Dilatation was defined as >45 mm at aortic sinus, sinotubular junction (STJ), ascending aorta (AA) and proximal arch and >40 mm from mid arch to abdominal aorta. A cardiovascular radiologist reviewed all cases with TAD according to AIRad. Multivariable logistic regression (MLR) was used to identify factors (demographics and scan parameters) associated with TAD classification by AIRad.

Results

18,243 CT scans (45.7% female) were successfully analyzed by AIRad. Mean age was 62.3 ± 15.9 years and 12,092 (66.3%) were CE scans. AIRad confirmed normal diameters in 17,239 exams (94.5%) and reported TAD in 1,004/18,243 exams (5.5%). Review confirmed TAD classification in 452/1,004 exams (45.0%, 2.5% total), 552 cases were false-positive but identification was easily possible using visual outputs by AIRad. MLR revealed that the following factors were significantly associated with correct TAD classification by AIRad: TAD reported at AA [odds ratio (OR): 1.12, p < 0.001] and STJ (OR: 1.09, p = 0.002), TAD found at >1 location (OR: 1.42, p = 0.008), in CE exams (OR: 2.1–3.1, p < 0.05), men (OR: 2.4, p = 0.003) and patients presenting with higher BMI (OR: 1.05, p = 0.01). Overall, 17,691/18,243 (97.0%) exams were correctly classified.

Conclusions

AIRad correctly assessed the presence or absence of TAD in 17,691 exams (97%), including 452 cases with previously missed TAD independent from contrast protocol. These findings suggest its usefulness as a secondary reading tool by improving report quality and efficiency.
Net clinical benefit of antithrombotic therapy for atrial fibrillation patients with stable coronary artery disease
Authors: Lee So-Ryoung , Jung Jin-Hyung , Choi Eue-Keun , Lee Seung-Woo , Kwon Soonil , Park Ji-Suck , Kang Jeehoon , Han Kyung-Do , Park Kyung Woo , Oh Seil , Lip Gregory Y. H.
Published: August 2022

Objectives

To compare the net clinical benefit of oral anticoagulant (OAC) monotherapy to OAC plus single antiplatelet therapy (SAPT) in patients with atrial fibrillation (AF) and stable coronary artery disease (CAD) at 1- and 3-year after percutaneous coronary intervention (PCI).

Background

It has not been studied whether the net clinical benefit of the antithrombotic treatment options differs depending on the elapsed time from the index PCI.

Methods

Using the Korean nationwide claims database, we included AF patients who underwent PCI from 2009 to 2019 and constructed two cohorts: 1- and 3-year after PCI. In each cohort, the baseline characteristics of two groups were balanced using propensity score weighting. Ischemic stroke, myocardial infarction, major bleeding, and composite clinical outcomes were analyzed.

Results

Among patients with 1-year after PCI, OAC monotherapy (n = 678), and OAC plus SAPT (n = 3,159) showed comparable results for all clinical outcomes. In patients with 3-year after PCI, OAC monotherapy (n = 1,038) and OAC plus SAPT (n = 2,128) showed comparable results for ischemic stroke and myocardial infarction, but OAC monotherapy was associated with a lower risk of composite clinical outcomes (HR 0.762, 95% CI 0.607–0.950), mainly driven by the reduction of major bleeding risk (HR 0.498, 95% CI 0.345–0.701).

Conclusion

Oral anticoagulant monotherapy may be a comparable choice for patients with AF and stable CAD compared to OAC plus SAPT. In patients with stable CAD more than 3-year after index PCI, OAC monotherapy would be a better choice, being associated with less major bleeding and a positive net clinical benefit.
Classification of seismic activity at the Lazufre Volcanic System, based on 2011 to 2012 data
Authors: McFarlin Heather , Thompson Glenn , McNutt Stephen R. , Braunmiller Jochen , West Michael E.
Published: August 2022

The Lazufre Volcanic System (LVS), on the border of northern Chile and Argentina, is an active complex of two volcanoes, Lastarria to the north and Cordón del Azufre to the south. The LVS is not regularly monitored with any scientific equipment despite being recognized as a top ten volcanic hazard in Argentina by the Observatorio Argentino de Vigilancia Volcánica of the Servicio Geológico y Minero Argentino. The system has shown unusual inflation signatures observed in InSAR but the level of seismic activity and its spatial and temporal distribution were unknown due to the lack of a permanent local seismic network. The PLUTONS Project deployed eight broadband seismic stations throughout the LVS between November 2011 and March 2013. This study shows event locations and types from November 2011 through March 2012. We analyze 591 seismic events within 20 km of Lastarria. Most events cluster tightly beneath Lastarria and almost no activity is observed beneath Cordón del Azufre or the primary inflation center. All events are reviewed manually, and located using a velocity model that assimilates prior studies and accounts for hypocenters within the edifice up to 5 km above sea level. More than 90% of the resulting hypocenters are shallower than 10 km below sea level. The waveforms have characteristics similar to those observed at many other volcanoes, suggesting five classes of events: volcano-tectonic (VT), long-period 1 (LP1), long period 2 (LP2), hybrid (HY), and unknown (X). Frequency-magnitude analysis reveals distinct b-values ranging from 1.2 for VT events to 2.5 for LP1 events. Based on the spatial distribution of events and the b-values, we infer that seismic activity is driven mainly by movement of fluids and gases associated with the regional magma zones and inflation centers. The seismic activity is energetic at times, and quieter at others, suggesting the presence of episodic magmatic and/or hydrothermal activity, focused at Lastarria. Our findings indicate that the previously observed inflation signals are indeed volcanic in origin. These results also demonstrate the potential for success of a future seismic monitoring system and provide a framework for interpreting the subsequent observations, both of which are critical to assessing the volcanic risk of the northern Chile-Argentina region.