bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction model for prolonged fever in patients with Mycoplasma pneumoniae pneumonia: a retrospective study of 716 pediatric patients
Authors: Jang Min Sik , Kim Bit Gyeol , Kim Jihye
Published: May 2021

Objective

To identify patients with Mycoplasma pneumoniae pneumonia (MPP) with a risk of prolonged fever while on macrolides.

Methods

A retrospective study was performed with 716 children admitted for MPP. Refractory MPP (RMPP-3) was defined as fever persisting for > 72 h without improvement in clinical and radiologic findings after macrolide antibiotics (RMPP-3) or when fever persisted for > 120 h (RMPP-5) without improvement in clinical and radiologic findings. Radiological data, laboratory data, and fever profiles were compared between the RMPP and non-RMPP groups. Fever profiles included the highest temperature, lowest temperature, and frequency of fever. Prediction models for RMPP were created using the logistic regression method and deep neural network. Their predictive values were compared using receiver operating characteristic curves.

Results

Overall, 716 patients were randomly divided into two groups: training and test cohorts for both RMPP-3 and RMPP-5. For the prediction of RMPP-3, a conventional logistic model with radiologic grouping showed increased sensitivity (63.3%) than the model using laboratory values. Adding laboratory values in the prediction model using radiologic grouping did not contribute to a meaningful increase in sensitivity (64.6%). For the prediction of RMPP-5, laboratory values or radiologic grouping showed lower sensitivities ranging from 12.9 to 16.1%. However, prediction models using predefined fever profiles showed significantly increased sensitivity for predicting RMPP-5, and neural network models using 12 sequential fever data showed a greatly increased sensitivity (64.5%).

Conclusion

RMPP-5 could not be effectively predicted using initial laboratory and radiologic data, which were previously reported to be predictive. Further studies using advanced mathematical models, based on large-sized easily accessible clinical data, are anticipated for predicting RMPP.
Loss of IL-33 enhances elastase-induced and cigarette smoke extract-induced emphysema in mice
Authors: Morichika Daisuke , Taniguchi Akihiko , Oda Naohiro , Fujii Utako , Senoo Satoru , Itano Junko , Kanehiro Arihiko , Kitaguchi Yoshiaki , Yasuo Masanori , Hanaoka Masayuki , Satoh Takashi , Akira Shizuo , Kiura Katsuyuki , Maeda Yoshinobu , Miyahara Nobuaki
Published: May 2021

Background

IL-33, which is known to induce type 2 immune responses via group 2 innate lymphoid cells, has been reported to contribute to neutrophilic airway inflammation in chronic obstructive pulmonary disease. However, its role in the pathogenesis of emphysema remains unclear.

Methods

We determined the role of interleukin (IL)-33 in the development of emphysema using porcine pancreas elastase (PPE) and cigarette smoke extract (CSE) in mice. First, IL-33−/− mice and wild-type (WT) mice were given PPE intratracheally. The numbers of inflammatory cells, and the levels of cytokines and chemokines in the bronchoalveolar lavage (BAL) fluid and lung homogenates, were analyzed; quantitative morphometry of lung sections was also performed. Second, mice received CSE by intratracheal instillation. Quantitative morphometry of lung sections was then performed again.

Results

Intratracheal instillation of PPE induced emphysematous changes and increased IL-33 levels in the lungs. Compared to WT mice, IL-33−/− mice showed significantly greater PPE-induced emphysematous changes. No differences were observed between IL-33−/− and WT mice in the numbers of macrophages or neutrophils in BAL fluid. The levels of hepatocyte growth factor were lower in the BAL fluid of PPE-treated IL-33−/− mice than WT mice. IL-33−/− mice also showed significantly greater emphysematous changes in the lungs, compared to WT mice, following intratracheal instillation of CSE.

Conclusion

These observations suggest that loss of IL-33 promotes the development of emphysema and may be potentially harmful to patients with COPD.
Analytical methods to assess the impacts of activity-based funding (ABF): a scoping review
Authors: Valentelyte Gintare , Keegan Conor , Sorensen Jan
Published: May 2021

Background

Activity-Based Funding (ABF) has been implemented across many countries as a means to incentivise efficient hospital care delivery and resource use. Previous reviews have assessed the impact of ABF implementation on a range of outcomes across health systems. However, no comprehensive review of the methods used to generate this evidence has been undertaken. The aim of this review is to identify and assess the analytical methods employed in research on ABF hospital performance outcomes.

Methods

We conducted a scoping review in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews. Five academic databases and reference lists of included studies were used to identify studies assessing the impact of ABF on hospital performance outcomes. Peer-reviewed quantitative studies published between 2000 and 2019 considering ABF implementation outside the U.S. were included. Qualitative studies, policy discussions and commentaries were excluded. Abstracts and full text studies were double screened to ensure consistency. All analytical approaches and their relative strengths and weaknesses were charted and summarised.

Results

We identified 19 studies that assessed hospital performance outcomes from introduction of ABF in England, Korea, Norway, Portugal, Israel, the Netherlands, Canada, Italy, Japan, Belgium, China, and Austria. Quasi-experimental methods were used across most reviewed studies. The most commonly used assessment methods were different forms of interrupted time series analyses. Few studies used difference-in-differences or similar methods to compare outcome changes over time relative to comparator groups. The main hospital performance outcome measures examined were case numbers, length of stay, mortality and readmission.

Conclusions

Non-experimental study designs continue to be the most widely used method in the assessment of ABF impacts. Quasi-experimental approaches examining the impact of ABF implementation on outcomes relative to comparator groups not subject to the reform should be applied where possible to facilitate identification of effects. These approaches provide a more robust evidence-base for informing future financing reform and policy.
The need for translation and cultural adaptation of audiology questionnaires to enable the development of hearing healthcare policies in the Pacific Islands: a Samoan perspective
Authors: Kaspar Annette , Pifeleti Sione , Driscoll Carlie
Published: May 2021

Background

Translation and cultural adaptation of health resources is an integral part of good health-policy development and health program implementation. As part of our efforts to address ear disease and hearing loss in the Pacific Islands, we promote the translation an cultural adaptation of hearing-related questionnaires into local languages and cultural contexts. The Pacific Islands have among the highest rates of ear and hearing disorders in the world and, given the scarcity of ear/hearing health professionals in the region, a public health approach that uses appropriately translated ear/hearing health resources is highly recommended to tackle this health issue.

Although formal translation and culturally adaption of hearing-related questionnaires may seem a cumbersome process, the aim of this commentary is to illustrate the potential benefits of translating two audiology questionnaires for our use in Samoa. We have carefully selected questionnaires that will serve multiple purposes (i.e., clinical, epidemiology, monitoring and evaluation, evidence-based health policy formulation and implementation), thus making the process ultimately beneficial and worthwhile.

Main body

The leading cause of preventable hearing loss among Samoan adolescents and young people is excessive noise exposure to recreational and environmental noise. The Youth Attitude to Noise Scale is a validated tool that assess knowledge and attitudes of adolescents towards recreational and environmental noise, and a Samoan version should provide preliminary data to guide health promotion activities for adolescents on noise-induced hearing loss.

The leading cause of hearing disability among older adult Samoans is age-related hearing loss. The Revised Hearing Handicap Inventory is a tool that assess the emotional and social/situational impact of hearing difficulty among older adults, and a Samoan version should provide preliminary data to guide the development of auditory rehabilitation services.

Conclusion

Investment in quality translations and cultural adaptations of hearing-related questionnaires is essential for the development of audiology services that are relevant to their Pacific Island context. The use of formally translated audiology questionnaires in research studies will optimise data quality, leading to improved hearing health promotion activities, as well as provision of evidence for advocacy for public health noise policy legislation.
Mental health and wellbeing implications of the COVID-19 quarantine for disabled and disadvantaged children and young people: evidence from a cross-cultural study in Zambia and Sierra Leone
Authors: Sharpe Darren , Rajabi Mohsen , Chileshe Clement , Joseph Sitali Mayamba , Sesay Ibrahim , Williams James , Sait Siraj
Published: May 2021

Background

The mental health impact of the COVID-19 pandemic and quarantining on children and young people (CYP) living in low- and middle-income countries (LMICs) has yet to be fully comprehended. CYP in LMICs are at utmost risk, given the COVID-19-related restrictions and social distancing measures, resulting in reduced access to school-based services for nutritional and mental health needs. This study examined mental health of CYP during the first COVID-19 lockdown in Zambia and Sierra Leone.

Method

A total of 468 disabled and disadvantaged CYP aged 12 to 25 completed a planning tool that comprised the short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS), as well as open-ended questions covering social connectedness, physical distancing and educational challenges during the lockdown. The community coaches screened individuals and families who could be eligible to receive emergency aid, and based on a convenience sample following distribution of aid, recipients were invited to complete the planning tool.

Results

The data showed that participants in the global south have increasing anxieties and fears centred on accessing offline educational resources and income loss in the family effecting food security and their ability to return to education. Mean (SD) SWEMWBS scores for all participants in Zambia and Sierra Leone, were 19.61 (3.45) and 21.65 (2.84), respectively. Mental well-being scores were lower in females, children aged 12–14 and participants with two or more disabilities. Factors significantly associated with poor mental wellbeing in the sample were: type of disability, nationality, peer relationships, connection to others during the pandemic, knowledge about COVID-19, worry about the long-term impact of COVID-19, and the types of self-isolating.

Conclusion

The study shows that participants who self-reported low levels of COVID-19 health literacy also scored low on the mental wellbeing self-assessment. Yet, despite undoubted limited resources, these CYP are doing well in identifying their needs and maintaining hope in the face of the problems associated with COVID-19 in countries where stigma persists around mental ill-health.
Linearity extensions of the market model: a case of the top 10 cryptocurrency prices during the pre-COVID-19 and COVID-19 periods
Authors: Neslihanoglu Serdar
Published: May 2021

This research investigates the appropriateness of the linear specification of the market model for modeling and forecasting the cryptocurrency prices during the pre-COVID-19 and COVID-19 periods. Two extensions are offered to compare the performance of the linear specification of the market model (LMM), which allows for the measurement of the cryptocurrency price beta risk. The first is the generalized additive model, which permits flexibility in the rigid shape of the linearity of the LMM. The second is the time-varying linearity specification of the LMM (Tv-LMM), which is based on the state space model form via the Kalman filter, allowing for the measurement of the time-varying beta risk of the cryptocurrency price. The analysis is performed using daily data from both time periods on the top 10 cryptocurrencies by adjusted market capitalization, using the Crypto Currency Index 30 (CCI30) as a market proxy and 1-day and 7-day forward predictions. Such a comparison of cryptocurrency prices has yet to be undertaken in the literature. The empirical findings favor the Tv-LMM, which outperforms the others in terms of modeling and forecasting performance. This result suggests that the relationship between each cryptocurrency price and the CCI30 index should be locally instead of globally linear, especially during the COVID-19 period.
Research on the composite and functional characteristics of leather fiber mixed with nitrile rubber
Authors: Guo Jun , Dai Rui , Chen Hui , Liang Yan , Shan Zhihua
Published: May 2021

The recycling of leather solid waste not only involves resource utilization and environmental protection but also has important significance for the sustainable development of the leather industry. In this paper, the leather waste was crushed into fibers, which were stabilized and mixed with nitrile-butadiene rubber (NBR). The mixture was milled and vulcanized and a composite NBR-SLF (Stabilized Leather Fiber) is prepared for sealing material. The physical and mechanical properties, water resistance, oil resistance and aging resistance of NBR-SLF were tested and analyzed. It is found that the optimized NBR-SLF not only reduces the cost of raw material, but also changes the physical and mechanical performance of NBR. As a sealing material, it satisfies the substitution of NBR in terms of hardness and thermal stability. Especially the anti-aging ability is better than NBR.

Graphical abstract
Synthesis of sulfonated Sesamum indicum L. seed oil and its application as a fatliquor in leather processing
Authors: Nkwor Adachukwu N. , Ukoha Pius O. , Ifijen Ikhazuagbe H.
Published: May 2021

Fatliquor is an oil-in-water emulsion that improves the physical properties of leather such as tensile strength, flexibility, and softness by lubricating the leather fibres. Sulfonated Sesamum indicum oil was synthesized, characterized, and examined for consideration as a substitute for imported fatliquor in Nigeria. The sulfonation of the oil was confirmed by the significant observations made in the FTIR, 1H NMR, 13C NMR, and 13C NMR DEPT analysis results. A remarkable difference was observed in the physicochemical properties results of both unsulfonated and sulfonated oils. The sulfonated sesame fatliquor was applied onto goatskin and compared with a commercial sulfated fatliquor in the processing of shoe upper leather using standard methods. The average results for tensile strength, double edge tear, elongation, and softness results for the commercial and synthesized fatliquors are as follows: 14.27 N/mm2; 13.77 N/mm2, 50.61 N; 60.11 N, 38.06%; 54.28%, 25.2; 25.0. A comparable level of lubrication of the leather treated with the sulfonated Sesamum indicum oil and that treated with the commercial leather fatliquor was revealed by the Sudan IV stain test as well as scanning electron microscopy analysis results. Experimental analyses, therefore, show that the as-synthesized sulfonated Sesamum indicum oil could be considered as a substitute for imported fatliquor in the leather industry.

Graphical abstract
Acute effects of cigarette smoke on Endothelial Nitric Oxide synthase, vascular cell adhesion molecule 1 and aortic intima media thickness
Authors: Ardiana Meity , Santoso Anwar , Hermawan Hanestya Oky , Nugraha Ricardo Adrian , Pikir Budi Susetyo , Suryawan I. Gde Rurus
Published: May 2021

Background. Cigarette smoking could induce endothelial dysfunction and the increase of circulating markers of inflammation by activation of monocytes. This can lead to increased intima media thickness (IMT) of entire blood vessels and result in acceleration of the atherosclerosis process. However, to our knowledge, little is known about the role of cigarette smoking in this atherosclerotic inflammatory process.

The aim of this study is to explore the link between cigarette smoking and its effect on endothelial nitric oxide synthase (e-NOS) and vascular cell adhesion molecule 1 (VCAM-1).

Methods. An experimental study with a post-test only controlled group design was used. We used 18 Wistar rats (Rattus norvegicus) randomly subdivided into two groups: group K (-) were not exposed to tobacco smoke, whereas group K (+) were exposed to smoke equivalent of more than 40 cigarettes for 28 days daily. After 28 days, samples were analyzed for e-NOS, VCAM-1 and aortic IMT.

Results. Our results indicate that tobacco smoke can enhance the expression of VCAM-1 on rat cardiac vascular endothelial cells, resulting in a decreased expression of e-NOS level and increase of aortic IMT. Linear regression model found that eNOS level negatively correlated wiith aortic IMT (r2 = 0.584, β = -0.764, p < 0.001), whereas VCAM-1 expression did not correlate with aortic IMT (r2 = 0.197, p = 0.065).

Conclusion. Low e-NOS level and high VCAM-1 level observed  after cigarette smoke exposure which may increase aortic IMT.
Rationality over fashion and hype in drug design
Authors: Medina-Franco José L. , Martinez-Mayorga Karina , Fernández-de Gortari Eli , Kirchmair Johannes , Bajorath Jürgen
Published: May 2021

The current hype associated with machine learning and artificial intelligence often confuses scientists and students and may lead to uncritical or inappropriate applications of computational approaches. Even the field of computer-aided drug design (CADD) is not an exception. The situation is ambivalent. On one hand, more scientists are becoming aware of the benefits of learning from available data and are beginning to derive predictive models before designing experiments. However, on the other hand, easy accessibility of in silico tools comes at the risk of using them as “black boxes” without sufficient expert knowledge, leading to widespread misconceptions and problems. For example, results of computations may be taken at face value as “nothing but the truth” and data visualization may be used only to generate “pretty and colorful pictures”. Computational experts might come to the rescue and help to re-direct such efforts, for example, by guiding interested novices to conduct meaningful data analysis, make scientifically sound predictions, and communicate the findings in a rigorous manner. However, this is not always ensured. This contribution aims to encourage investigators entering the CADD arena to obtain adequate computational training, communicate or collaborate with experts, and become aware of the fundamentals of computational methods and their given limitations, beyond the hype. By its very nature, this Opinion is partly subjective and we do not attempt to provide a comprehensive guide to the best practices of CADD; instead, we wish to stimulate an open discussion within the scientific community and advocate rational rather than fashion-driven use of computational methods. We take advantage of the open peer-review culture of F1000Research such that reviewers and interested readers may engage in this discussion and obtain credits for their candid personal views and comments. We hope that this open discussion forum will contribute to shaping the future practice of CADD.
A scoping review protocol of evidence-based guidance published by general practitioner professional organisations
Authors: O'Brien Emer , Clyne Barbara , Smith Susan M. , O'Herlihy Noirin , Harkins Velma , Wallace Emma
Published: May 2021

Introduction: General practitioners (GPs) strive to use a patient centred approach to achieve shared decision making by integrating clinical evidence, clinical judgement, and patient priorities. This protocol outlines a scoping review to identify what evidence-based guidance is produced by general practitioner professional organisations internationally to support general practice clinical decision making.

Methods: This scoping review will be conducted using the framework proposed by the Joanna Briggs Institute and the Preferred Reporting Items for Systematic Reviews and Meta-analysis extension for scoping reviews (PRISMA-ScR), will be used to guide the reporting. Two researchers will search electronic databases (Medline, Embase, Cochrane Library and Scopus), grey literature sources and contact international GP professional organisations directly to identify appropriate studies for inclusion. Key information will be categorised and classified to generate a summary of the methods used internationally to develop and implement evidence-based guides for general practitioners and a narrative synthesis will be conducted.

Conclusions: This scoping review will identify the role of GP professional organisations in generating, endorsing and/or disseminating evidence-based guidance for supporting general practitioner’s clinical decision making to benefit patient care.
Low diagnostic yield and time to diagnostic confirmation results in prolonged use of antimicrobials in critically ill children
Authors: Clark John , White Deborah , Daubney Esther , Curran Martin , Bousfield Rachel , Gouliouris Theodore , Powell Elizabeth , Palmer Adam , Agrawal Shruti , Inwald David , Kean Iain , Török M. Estée , Baker Stephen , Pathan Nazima
Published: May 2021

Background: Broad-spectrum antimicrobial therapy is a key driver of antimicrobial resistance. Here, we aimed to review indications for antimicrobial therapy, determine the proportion of suspected bacterial infections that are confirmed by culture, and assess the time taken for microbiology test results to become available in the paediatric intensive care unit (PICU).

Methods: A single-centre prospective observational cohort study of 100 consecutive general PICU admissions from 30 October 2019 to 19 February 2020. Data were collected from the hospital medical record and entered into a study database prior to statistical analysis using standard methods.

Results: Of all episodes of suspected infection, 22% of lower respiratory tract infection, 43% of bloodstream and 0% of central nervous system infection were associated with growth on microbiology culture. 90% of children received antimicrobial therapy. Hospital-acquired infection occurred less commonly than primary infection, but an organism was grown in a greater proportion (64%) of cultures. Final laboratory reports for negative cultures were issued at a median of 120.3 hours for blood cultures and 55.5 hours for endotracheal tube aspirate cultures.

Conclusions: Despite most critically children receiving antimicrobial therapy, infection was often not microbiologically confirmed. Novel molecular diagnostics may improve rationalisation of treatment in this population.
¿Os recibimos con alegría? Il viaggio di Olga Raggio a Vélez Blanco nel 1959: l’itinerario, gli interlocutori, i rapporti frail Metropolitan Museum e le istituzioni spagnole.
Authors: Mozzati Tommaso
Published: May 2021

L’articolo intende ripercorrere il dialogo apertosi fra il Metropolitan Museum of Art di New York, le autorità ministeriali spagnole e l’intelligentsia andalusa negli anni compresi fra il 1959 e il 1963, cioè durante la ricostruzione del patio proveniente dal castello di Vélez Blanco nelle sale dell’istituzione newyorkese. Nel far questo il contributo si propone di ricollocare una simile rete di relazioni sullo sfondo della più ampia situazione politica e diplomatica vissuta in quegli anni dal regime franchista all’interno della comunità internazionale e, in particolare, nel contesto dei negoziati intrattenuti al tempo con il governo di Washington.
Continuity of General Training of Future Teachers and Academics in the Context of a Three-level System of Education
Authors:   State Institution Luhansk Taras Shevchenko National University, Butenko Ludmila
Published: May 2021

The author has analyzed the term ‘general teachers’ training’ in modern scientific discourse. Peculiarities of general training of future teachers and academics in the context of a three-level system of higher education (Bachelor’s course, Master’s course and post-graduate course) have been disclosed. The researcher has substantiated the need for contiguity of general training of future teachers, Master’s students and postgraduate students who have teaching as their major. The ways, the content and the peculiarities of the methodological support for providing contiguity of general training of future teachers and academics at university have been described. General teachers’ training of future specialists in the field of education (bachelor's, master's, postgraduate) should provide conceptual-target continuity; content and information continuity, technological and activity continuity.
Socio-Psychological Factors of the Formation of Conflict Competence of a Specialist in the Work Community
Authors:   Alfred Nobel University, Voshcolup Anna
Published: May 2021

The article based on the analysis of scientific works on nature of conflicts proves that conflict can be considered from three different perspectives: as a psychological phenomenon under the influence of the human factor on the basis of disagreement; as an organizational and activity phenomenon based on the imbalance between a person and their environment; as a socio-philosophical phenomenon associated with the perception of conflict as a social anomaly. The chronology of scientific doctrines about the essence and nature of conflict, the reasons for its occurrence and ways to avoid and prevent it have been outlined. It has been determined that conflicts in the work community are one of the types of social conflicts, the nature of which is associated with the use of labour (with labour relations) and the relationship of professionals in the work community (cooperation, collective problem solving, the pair «manager-subordinate», unfair distribution of duties, rights, responsibilities, etc.). The essential significance of conflict competence has been characterized, and the importance of forming this competence of specialists in the work community has been emphasized. Conflict competence has been structured into competencies and components of a lower level. The componential and structural analysis of such a phenomenon of conflict competence with the aim of minimizing conflicts in the work community has allowed identifying the following components: motivational (emotional and volitional, and constructive competences); cognitive (normative, personal and creative competences); managerial (design, reflective, regulatory, situational and preventive competencies); social (behavioural and ethical competences).
Top tips for wellbeing success
Authors: Gujral Joel
Published: May 2021

Joel Gujral from mental health start-up MYNDUP offers advice for boosting wellbeing and productivity amid challenging circumstances
Neural Network Identification and Direct Adaptive Fuzzy Neural Network (DAFNN) Controller for Unknown Nonlinear Non-affine Pneumatic Servo System
Authors: Mawlani Peyman , Arbabtafti Mohammadreza
Published: May 2021

In this paper, a direct adaptive fuzzy neural network (DAFNN) controller for trajectory tracking control of the non-linear non-affine pneumatic servo system is presented. First, using a neural network identifier, the non-linear dynamics of a real pneumatic servo system is simulated. By comparing the output of the neural network and the output of the experimental setup, it is observed that the non-linear pneumatic actuator system is well-identified using neural networks. By incorporating the Lyapunov stability theorem, the adaptive laws for the parameters of the controller are obtained, parameter boundedness and stability of the closed-loop system are guaranteed. Finally, practical results are successfully implemented for trajectory tracking control of the pneumatic servo system, in which the effect of the simultaneous updating of the antecedent and consequent’s parameters of the fuzzy neural network controller has been investigated. The tracking error ±1.3mm and ±1 mm for proposed updating method compared to ±2.5mm and ±3.5mm, for a case that the weigh parameters are merely adjusted, are obtained. The results indicate the proposed adjustment method improves the performance of the controller in the presence of unknown nonlinearities and dynamics uncertainty.
Model-based Simulation of a Hydraulic Closed-loop Rotary Transmission with Automatic Control
Authors: Grossschmidt Gunnar , Harf Mait
Published: May 2021

Model-based simulation of a hydraulic closed-loop rotary transmission with automatic control of hydraulic pump and hydraulic motor is considered in the paper. The approach is based on multi-pole modelling and intelligent simulation. In the paper the functional scheme of the transmission is proposed and multi-pole models of components are introduced. Mathematical multi-pole models of components for steady state conditions and for dynamic transient responses are presented. A high-level graphical environment CoCoVila (compiler compiler for visual languages) is used as a tool for describing models and performing simulations. Object-oriented multi-pole models, visual programming environment, automatic program synthesis and distributed computing are as original approach in simulation of fluid power systems.
A Note on Leakage Jet Forces: Application in the Modelling of Digital Twins of Hydraulic Valves
Authors: Lauer-Baré Zoufiné , Gaertig Erich , Krebs Johannes , Arndt Christian , Sleziona Christian , Gensel André
Published: May 2021

The proper modelling of fluid flow through annular gaps is of great interest in leakage calculations for many applications in fluid power technology. However, while detailed numerical simulations are certainly possible, they are very time consuming, in various cases prone to numerical instabilities and may not even include all physically relevant effects. This is an issue especially in system simulations, where a large set of computations is needed in order to prepare the lookup-tables for the required input fields. In this work, an analytical approximation for the shear force, which is induced by viscous flow between two eccentric cylinders, is presented. This relation, and its derivation, mimics and enhances the well-known Piercy-relation for the corresponding volume flow that is utilized in state-of-the-art system simulation tools. To determine its range of validity, the analytical relation for the shear force is compared to 3D-simulations. Additionally, an application of this approximation for creating digital twins of hydraulic valves is also discussed in this work.
Towards Standardized Prevention of Unsolicited Communications and Phishing Attacks
Authors: Song JaeSeung , Kunz Andreas
Published: May 2021

The world of communication technology is changing fast and the means of communication are moving towards a packet switched transmission systems such as Voice over IP (VoIP). Formerly call identity spoofing of the displayed number in circuit switched (CS) networks was too difficult to perform so that people could be sure that when receiving a call on their mobile phone or at home, the displayed number is the one as it is supposed to be. Nowadays this is not the case anymore, voice communication from the internet with VoIP is cheap and spam calls can be easily realized without any costs, also it is getting easier to perform spoofed calls with wrong display name or number.

The mobile network operators have no mechanisms to tackle those threats, but standardization activities are already in place within the security group SA3 of 3GPP. This paper provides an overview of the current status of the standards activities and shows the most promising solutions that are proposed up to now. The proposed solutions detect unsolicited communications and spoofed calls by tracing back to the displayed number used in the attack.
LoRaWAN Link Layer
Authors: Seller Olivier
Published: May 2021

The LoRaWAN Link Layer specification [1] is a communication protocol for the Internet of Things. It targets low power, long range, low cost communication using unlicensed spectrum. Network topology is collaborative, which reduces a lot protocol signalling compared to a cellular network. The device is connected to a network server, and protocol overhead is limited to 13 bytes for any data frame. There are three classes of operation. Class A is optimized for low power operation of end-devices, while class B and class C offer reduced downlink latency. The protocol specification offers several mechanisms to adjust the link layer parameters: adaptive data rate, adaptive power control, variable repetition rate, and channel selection.
LoRa Alliance Certification
Authors: Hunt Derek
Published: May 2021

LoRaWAN® Certification of devices is critical for effective and efficient mass deployment of LoRaWAN Networks, as it ensures devices will work on any network, under all conditions. Certified Devices significantly reduce the support costs as any product failures detected later when the device is deployed is far more expensive to repair and poor RF performance of the device increase number of gateways needed and cost of the network infostructure.
Recognition Method of Abnormal Behavior of Marine Fish Swarm Based on In-Depth Learning Network Model
Authors: Chen Liyong , Yin Xiuye
Published: May 2021

In order to solve the problem that individual coordinates are easily ignored in the localization of abnormal behavior of marine fish, resulting in low recognition accuracy, execution efficiency and high false alarm rate, this paper proposes a method of fish abnormal behavior recognition based on deep learning network model. Firstly, the shadow of the fish behavior data is removed, and the background image is subtracted from each frame image to get the gray image of the fish school. Then, the label watershed algorithm is used to identify the fish, and the coordinates of different individuals in the fish swarm are obtained. Combined with the experimental size constraints and the number of fish, and combined with the deep learning network model, the weak link of video tag monitoring of abnormal behavior of marine fish is analyzed. Finally, the multi instance learning method and dual flow network model are used to identify the anomaly of marine fish school. The experimental results show that the method has high recognition accuracy, low false alarm rate and high execution efficiency. This method can provide a practical reference for the related research in this field.
Local and Temporal Effects on Ant Richness, Recruitment and Resource Dominance in Two Cerrado Areas
Authors: Dos Santos Liegy Resende , Moura Renan
Published: May 2021

Ecological interactions and environmental conditions are associated with community structuring, where the resource quality and availability, in addition to interspecific competition, determine potential local interactions. Using ground-dwelling ant species as a methodological tool model, we evaluated how three different daily periods affected species richness, recruitment, and resource dominance (baits) within two Cerrado (Brazilian savanna) phytophysiognomies. We found a total of 34 ant species and significant differences in species composition between the cerrado areas. Camponotus and Pheidole genera were the most abundant in both studied areas in which several species shared baits. Ant richness did not vary between the cerrado areas, but ant recruitment was affected by observation periods: in both areas, the hottest period (afternoon) reflected the lowest recruitment, while the coolest period (morning) had the highest recruitment. We observed that the ant species that first found baits had a 29% chance of being the only species observed using the resource, while those that arrived after other species had only 7%. Both areas promote the coexistence of ant species by shaping their interactions. We suggest that environmental structuring promotes niche partitioning in both spatial and temporal scales, providing possibilities of microhabitats that allow species to explore the environment and forage.
Beam propagation simulation of phased laser arrays with atmospheric
perturbations
Authors: Hettel Will , Meinhold Peter , Suen Jonathan Y. , Srinivasan Prashant , Krogen Peter , Wirth Allan , Lubin Philip
Published: May 2021

Directed energy phased array (DEPA) systems have been proposed for applications such as beaming optical power for electrical use on remote sensors, rovers, spacecraft, and future moon bases, as well as for planetary defense against asteroids and photonic propulsion up to relativistic speeds. All such scenarios involve transmission through atmosphere and beam perturbations due to turbulence that must be quantified. Numerical beam propagation and feedback control simulations were performed using an algorithm optimized for efficient calculation of real-time beam dynamics in a Kolmogorov atmosphere. Results were used to quantify the effectiveness of the system design with different degrees of atmospheric turbulence and zenith angles, and it was found that a large aperture DEPA system placed at a high altitude site can produce a stable diffraction limited spot (

S
t
r
e
h
l

>

0.8

) on space-based targets for Fried length

r
0

≥
10

c
m

(at 500 nm) and zenith angles up to 60 deg, depending on atmospheric conditions. We believe these results are promising for the next generation of power beaming and deep space exploration applications.
Controlling Tamm phonons using hBN and a distributed Bragg reflector for narrowband refractive index sensing
Authors: Wang Li , Liu Jinlai , Ren Bin , Cui Ying , Song Jie , Jiang Yongyuan
Published: May 2021

Optical Tamm state with sharp reflection dip provides the sensing potential combined with high sensitivity. In this paper, we numerically demonstrate that narrowband refractive index sensing can be realized in a distributed Bragg reflector (DBR) structure with hexagonal boron nitride (hBN). Here, we show that the sensitivity and narrowband properties can not only be regularly governed by different analyte thickness but also exhibit dependence on the number of DBR pairs and the thickness of the hBN layer. With varying the analyte index and optimized analyte thickness, the deep reflectance dip can be sustained with the sensitivity (figure of merit, FOM) close to 3.02 µm/RIU (1093/RIU). In addition, the different analyte categories can be detected through adjusting the thickness of the analyte-filled cavity. High sensitivity, combined with ultra-high FOM originated from strong Tamm phonon mode, offers a promising platform to detect the smallest variation of the refractive index.
High-speed label-free confocal microscopy of Caenorhabditis elegans with near infrared spectrally encoded confocal microscopy
Authors: Rashtchian Sadaf , Youssef Khaled , Rezai Pouya , Tabatabaei Nima
Published: May 2021

Caenorhabditis elegans (C. elegans)
is an optically transparent nematode that shares many gene orthologs
and homologs with humans. C. elegans are widely used
in large populations for genetic studies relevant to human biology and
disease. Success of such studies frequently relies on the ability to
image C. elegans structure at high-resolution and
high-speed. In this manuscript, we report on the feasibility and
suitability of a high-speed variant of reflectance confocal
microscopy, known as spectrally encoded confocal microscopy (SECM),
for label-free imaging of C. elegans. The developed
system utilizes near-infrared illumination in conjunction with
refractive and diffractive optics to instantaneously image a confocal
image line at a speed of up to 147 kHz with lateral and axial
resolutions of 2µm and 10µm, respectively. Our imaging
results from wild-type C. elegans and four mutant
strains (MT2124, MT1082, CB61, and CB648) demonstrate the ability of
SECM in revealing the overall geometry, key internal organs, and
mutation-induced structural variations, opening the door for
downstream integration of SECM in microfluidic platforms for high
throughput structural imaging of C. elegans.
Photodynamic therapy reduces metastasis of breast cancer by minimizing circulating tumor cells
Authors: Weng Xiaofu , Wei Dan , Yang Zhangru , Pang Wen , Pang Kai , Gu Bobo , Wei Xunbin
Published: May 2021

Cancer metastasis after traditional surgery introduces a high barrier to therapy efficacy. Photodynamic therapy (PDT) for cancer is based on a photochemical process of photosensitizers that concentrate in tumors and release oxidant species under light excitation to destroy cells. Compared with traditional surgery, PDT provides minimal invasion and targeted therapy. In this in vivo study, we monitor the real-time and long-term dynamics of circulating tumor cells (CTCs) after a single round of PDT and after surgical resection in a breast cancer animal model. The CTC level is low after PDT treatment, and the recurrence of the primary tumor is postponed in the PDT group compared with the resection group. We find that metastasis is correlated with the CTC level, and the PDT-treated mice show no metastasis in the lung or liver. Our results suggest PDT can effectively reduce metastasis by minimizing CTCs after treatment and is a great technology for breast cancer therapy.
Dynamic control of THz polarization modulation and multi-channel beam generation using a programmable metasurface
Authors: Ren Bin , Feng Yuxin , Tang Shuai , Wang Li , Jiang Huan , Jiang Yongyuan
Published: May 2021

Polarization modulation and multichannel beam generation are crucial in multichannel communication and high-resolution imaging at THz frequency. In this work, we present a polarization-reprogrammable coding metasurface composed of VO2/Au composite concentric rings (CCRs). Owing to the phase-change property of VO2, the CCR is designed as a digital coding element for the polarization conversion. When VO2 remains insulator state at room temperature, the y-polarized incident wave is transformed into x-polarized wave, which can be regarded as digital state 0. When VO2 converts into metal state at critical temperature (68 °C), the polarization of reflected wave stays unchanged, corresponding to digital state 1. Any desired linear polarization state of reflected beam is achieved by taking advantage of different coding sequences in a programmable manner. Furthermore, by combining phase gradient with polarization coding states, we propose an anisotropic programmable metasurface to control the multi-channel reflected beams dynamically. By arranging distinct coding sequences, we show that the EM reflected beams can be manipulated flexibly. The proposed programmable metasurface paves new ways towards THz polarization manipulation, signal detection and information communication.
Extremely low light scattering in nanostructured glasses formed by simultaneous nucleation and diffusion-limited growth of particles: modeling: erratum
Authors: Shepilov Michael P.
Published: May 2021

We present an erratum to our Letter [Opt. Lett.
45, 3645 (2020)OPLEDP0146-959210.1364/OL.386605].
Labeling errors in one figure and corresponding sentence in the text
are corrected. The corrections have no influence on the results and
conclusions of the original Letter.
A megfelelő ellátásilánc-stratégia kiválasztása
Authors: Hackler János
Published: May 2021

Az elmúlt évtizedek alatt mind a nemzetközi kereskedelem, mind a külföldi működőtőke-beruházások értéke hatalmas mértékben emelkedett, és ezzel párhuzamosan a nagyobb termelő vállalatok szerepe is megváltozott. A folyamat során a nagyvállalatok többsége úgynevezett érték hálózattá alakult, ami alatt a különböző, nem feltétlenül egy kézben lévő egységek hálózatát értjük, ahol az egyes pontokon különböző formában növelik a termék fogyasztói értékét. Az értékhálózatok egyik kutatási területe az ellátásilánc­menedzsment (supply chain management) elmélete. A dolgozatban a szerző arra keresi a választ, hogy milyen szempontok segíthetnek egy vállalatnak a megfelelő ellátásilánc-stratégia kiválasztásában.
Assessment of the quality of life of patients after parathyroidectomy from standard and small access
Authors: Ogorodnikov A. V. , Kharnas S. S.
Published: May 2021

BACKGROUND. Primary hyperparathyroidism (PGPT) is an increase in the secretory activity of the parathyroid glands (OSH), due to their tumor or hyperplastic changes. Due to the lack of an effective alternative to the treatment of PGPT, the surgical method is still the only correct tactical solution for the management of patients with an established diagnosis of PGPT. The paper presents the long-term results and assessment of the quality of life of patients who underwent surgical treatment from standard and small access. The results obtained showed the promise of a sparing approach to the treatment of PGPT caused by LV adenoma.AIM. To study the effectiveness of surgical treatment of patients with PGPT based on the assessment of the quality of life of patients who underwent parathyroidectomy from standard and small access.MATERIALS AND METHODS. A retrospective study of the quality of life of patients with PGPT after surgical treatment was conducted using the SF-36 questionnaire and the linear analog scale (LAS). Statistical data processing is performed in the R programming language using the FMSB package. The quantitative parameters were presented as median (Median) and interquartile range (25th (1st Qu) — lower quartile and 75th (3rd Qu ) — upper quartile). As a nonparametric statistical criterion, the Mann–Whitney U-test was used, on the basis of which the p-value was calculated. The calculated data of the research results are presented in graphical form — in the form of bar charts, spider plot and barplot.RESULTS. This study involved 264 patients. The patients were divided into 2 groups: GR1 — patients operated from the Kocher access with mandatory revision of all 4 OSH, GR2 — patients who received surgical treatment from the small access with the removal of the altered OSH, without revision of the remaining OSH. When analyzing the quality of life of patients before surgery, there were no statistically significant differences in the groups in terms of PF (Physical Functioning) and VT (Vitality). Small-access parathyroidectomy (patients with GR 2) significantly improved the quality of life in the GH (General Health) and VT (Vitality) domains. The analysis of LAS before surgery between the groups showed no statistically significant differences, while after surgical treatment, the indicators on the linear analog scale differ in the direction of improvement in GR2.CONCLUSION. The results obtained in the course of the study showed the promise of a gentle approach to the treatment of PGPT caused by LV adenoma, which is reflected in higher quality of life indicators.