bluuebunny/crossref_metadata_2025 huggingface dataset:
Types of Submanifolds in Metallic Riemannian Manifolds: A Short Survey
Authors: Hretcanu Cristina E. , Blaga Adara M.
Published: October 2021

We provide a brief survey on the properties of submanifolds in metallic Riemannian manifolds. We focus on slant, semi-slant and hemi-slant submanifolds in metallic Riemannian manifolds and, in particular, on invariant, anti-invariant and semi-invariant submanifolds. We also describe the warped product bi-slant and, in particular, warped product semi-slant and warped product hemi-slant submanifolds in locally metallic Riemannian manifolds, obtaining some results regarding the existence and nonexistence of non-trivial semi-invariant, semi-slant and hemi-slant warped product submanifolds. We illustrate all these by suitable examples.
Algebraic Solution of Tropical Polynomial Optimization Problems
Authors: Krivulin Nikolai
Published: October 2021

We consider constrained optimization problems defined in the tropical algebra setting on a linearly ordered, algebraically complete (radicable) idempotent semifield (a semiring with idempotent addition and invertible multiplication). The problems are to minimize the objective functions given by tropical analogues of multivariate Puiseux polynomials, subject to box constraints on the variables. A technique for variable elimination is presented that converts the original optimization problem to a new one in which one variable is removed and the box constraint for this variable is modified. The novel approach may be thought of as an extension of the Fourier–Motzkin elimination method for systems of linear inequalities in ordered fields to the issue of polynomial optimization in ordered tropical semifields. We use this technique to develop a procedure to solve the problem in a finite number of iterations. The procedure includes two phases: backward elimination and forward substitution of variables. We describe the main steps of the procedure, discuss its computational complexity and present numerical examples.
Observer-Based Robust Control Method for Switched Neutral Systems in the Presence of Interval Time-Varying Delays
Authors: Ghadiri Hamid , Khodadadi Hamed , Mobayen Saleh , Asad Jihad H. , Rojsiraphisal Thaned , Chang Arthur
Published: October 2021

In this study, the challenges of the controller design of a class of Uncertain Switched Neutral Systems (USNSs) in the presence of discrete, neutral, and time-varying delays are considered by using a robust observer-based control technique. The cases where the uncertainties are normbounded and time-varying are emphasized in this research. The adopted control approach reduces the prescribed level of disturbance input on the controlled output in the closed-loop form and the robust exponential stability of the control system. The challenge of parametric uncertainty in USNSs is solved by designing a robust output observer-based control and applying the Yakubovich lemma. Since the separation principle does not generally hold in this research, the controller and observer cannot be designed separately, sufficient conditions are suggested. These conditions are composed of applying the average dwell time approach and piecewise Lyapunov function technique in terms of linear matrix inequalities, which guarantees robust exponential stability of the observer-based output controller. Finally, two examples are given to determine the effectiveness of the proposed method.
Dynamic Programming Algorithms for Computing Optimal Knockout Tournaments
Authors: Bădică Amelia , Bădică Costin , Buligiu Ion , Ciora Liviu Ion , Logofătu Doina
Published: October 2021

We study competitions structured as hierarchically shaped single-elimination tournaments. We define optimal tournaments by maximizing attractiveness such that the topmost players will have the chance to meet in higher stages of the tournament. We propose a dynamic programming algorithm for computing optimal tournaments and we provide its sound complexity analysis. Based on the idea of the dynamic programming approach, we also develop more efficient deterministic and stochastic sub-optimal algorithms. We present experimental results obtained with the Python implementation of all the proposed algorithms regarding the optimality of solutions and the efficiency of the running time.
On a Bivariate Generalization of Berrut’s Barycentric Rational Interpolation to a Triangle
Authors: Bos Len , De Marchi Stefano
Published: October 2021

We discuss a generalization of Berrut’s first and second rational interpolants to the case of equally spaced points on a triangle in R2.
Structural Optimization and Application Research of Alkali-Activated Slag Ceramsite Compound Insulation Block Based on Finite Element Method
Authors: Fan Xiaona , Guo Yu , Zhao Qin , Zhu Yiyun
Published: October 2021

The research and application of new wall materials have been attracting increasing attention owing to the continuous promotion of sustainable development in the building industry. An alkali-activated slag ceramsite compound insulation block (AASCCIB) is used as the research object. Based on the finite element method, the effects of different numbers of hole rows and hole ratios on the thermal and mechanical performances of AASCCIBs are analyzed using ANSYS CFX. On this basis, the AASCCIB with the optimal comprehensive performance is determined by a multi-objective optimization analysis. Finally, the improvement effect of the AASCCIB wall on the indoor thermal environment relative to an ordinary block (OB) wall is quantitatively analyzed using ANSYS CFX. The results show that the von Mises equivalent stress and heat transfer coefficient of the AASCCIB decrease with the increase in the hole ratio when the hole shape and number of hole rows are constant. AASCCIB B1 has the optimal comprehensive performance among six AASCCIBs, with the heat transfer coefficient and average von Mises equivalent stress of 0.446 W/(m2∙K) and 9.52 MPa, respectively. Compared with the indoor lowest and average temperatures of the building with the OB wall, those of the building with the AASCCIB wall increased by at least 1.39 and 0.82 °C on the winter solstice, respectively. The indoor temperature difference decreased by at least 0.83 °C. In addition, the indoor highest temperature, average temperature, and temperature difference decreased by at least 1.75, 0.79, and 1.89 °C on the summer solstice, respectively.
Weak and Strong Convergence Theorems for Common Attractive Points of Widely More Generalized Hybrid Mappings in Hilbert Spaces
Authors: Thongpaen Panadda , Kaewkhao Attapol , Phudolsitthiphat Narawadee , Suantai Suthep , Inthakon Warunun
Published: October 2021

In this work, we study iterative methods for the approximation of common attractive points of two widely more generalized hybrid mappings in Hilbert spaces and obtain weak and strong convergence theorems without assuming the closedness for the domain. A numerical example supporting our main result is also presented. As a consequence, our main results can be applied to solving a common fixed point problem.
Non-Sequential Linear Construction Project Scheduling Model for Minimizing Idle Equipment Using Constraint Programming (CP)
Authors: Liu Shu-Shun , Budiwirawan Agung , Arifin Muhammad Faizal Ardhiansyah
Published: October 2021

Over the last several decades, the scheduling of linear construction projects (LCPs) has been explored extensively by experts. The linear scheduling method (LSM), which focuses on work rate and work continuity, has the advantage of tackling LCPs’ scheduling problems. The traditional LSM uses work continuity to monitor resource allocation continuity on the premise that activities with the same type of work use the same crew. However, some LCPs require a combination of different types of equipment to comprise the crew. Sometimes, parts of different crews require the same types of equipment, and sometimes, the same crew requires different equipment configurations. This causes the pattern of work continuity to be different from the pattern of resource allocation continuity. Therefore, we propose an optimization model of the LSM to minimize idle equipment on a non-sequential linear construction project—i.e., a road network maintenance project. This model is intended to minimize the number of idle equipment and their idle time to achieve more efficient scheduling for linear construction projects. This model offers novel details of resource allocation continuity assessment by taking into account equipment combination and configuration (ECC). Therefore, the scheduling concept used by the proposed model is named the linear scheduling model with ECC (LSM–ECC). The model was developed using constraint programming (CP), as CP has good performance and robustness in the optimization field. The model was implemented to a representation of a road network maintenance project and has satisfactory results.
Analysing Probability Teaching Practices in Primary Education: What Tasks Do Teachers Implement?
Authors: Vásquez Claudia , Alsina Ángel
Published: October 2021

This study analyses probability tasks proposed by primary education teachers to promote probabilistic literacy. To this end, eight class sessions at various levels of the Chilean educational system were recorded on video and analysed through the ”probability tasks” dimension from the “Observation Instrument for Probability Classes” (IOC-PROB), which includes five components: use of resources, probabilistic contexts, cognitive challenge, procedures and strategies, and probability meanings. The results show that probability tasks focus mainly on technical knowledge, causing the probability class to become an arithmetic class in which only formulas are applied, mechanically and with no meaning. As a result, we see no use of technological resources, a low use of physical materials, and an absolute predominance of solving decontextualised exercises. We conclude that it is necessary to enhance the probability teaching practices based on lesson plans that consider a wide variety of resources and contexts to gradually advance towards a representation of probabilistic knowledge that relies on conventional procedures and notations.
Koopman Operator Framework for Spectral Analysis and Identification of Infinite-Dimensional Systems
Authors: Mauroy Alexandre
Published: October 2021

We consider the Koopman operator theory in the context of nonlinear infinite-dimensional systems, where the operator is defined over a space of bounded continuous functionals. The properties of the Koopman semigroup are described and a finite-dimensional projection of the semigroup is proposed, which provides a linear finite-dimensional approximation of the underlying infinite-dimensional dynamics. This approximation is used to obtain spectral properties from the data, a method which can be seen as a generalization of the Extended Dynamic Mode Decomposition for infinite-dimensional systems. Finally, we exploit the proposed framework to identify (a finite-dimensional approximation of) the Lie generator associated with the Koopman semigroup. This approach yields a linear method for nonlinear PDE identification, which is complemented with theoretical convergence results.
Connecting Mathematics and Science in Primary School STEM Education: Modeling the Population Growth of Species
Authors: Gamboa Genaro de , Badillo Edelmira , Couso Digna , Márquez Conxita
Published: October 2021

In this research, we explored the potential of using a research-based teaching and learning sequence to promote pupils’ engagement in practices that are coherent with those of real world mathematical and scientific activity. This STEM (Science, Technology, Engineering and Mathematis) sequence was designed and implemented by pre-service teachers and science and mathematics education researchers with the aim of modeling the growth of a real population of rabbits. Results show explicit evidence of pupils’ engagement in relevant mathematical and scientific practices, as well as detailed descriptions of mathematical connections that emerged from those practices. We discuss how these practices and connections allowed the progressive construction of models, and the implications that this proposal may have for STEM task design and for the analysis of extra-mathematical connections.
Incorporating a New Summary Statistic into the Min–Max Approach: A Min–Max–Median, Min–Max–IQR Combination of Biomarkers for Maximising the Youden Index
Authors: Aznar-Gimeno Rocío , Esteban Luis M. , Sanz Gerardo , del-Hoyo-Alonso Rafael , Savirón-Cornudella Ricardo
Published: October 2021

Linearly combining multiple biomarkers is a common practice that can provide a better diagnostic performance. When the number of biomarkers is sufficiently high, a computational burden problem arises. Liu et al. proposed a distribution-free approach (min–max approach) that linearly combines the minimum and maximum values of the biomarkers, involving only a single coefficient search. However, the combination of minimum and maximum biomarkers alone may not be sufficient in terms of discrimination. In this paper, we propose a new approach that extends that of Liu et al. by incorporating a new summary statistic, specifically, the median or interquartile range (min–max–median and min–max–IQR approaches) in order to find the optimal combination that maximises the Youden index. Although this approach is more computationally intensive than the one proposed by Liu et al, it includes more information and the number of parameters to be estimated remains reasonable. We compare the performance of the proposed approaches (min–max–median and min–max–IQR) with the min–max approach and logistic regression. For this purpose, a wide range of different simulated data scenarios were explored. We also apply the approaches to two real datasets (Duchenne Muscular Dystrophy and Small for Gestational Age).
ABS-Based Direct Method for Solving Complex Systems of Linear Equations
Authors: Abaffy József , Fodor Szabina
Published: October 2021

Efficient solution of linear systems of equations is one of the central topics of numerical computation. Linear systems with complex coefficients arise from various physics and quantum chemistry problems. In this paper, we propose a novel ABS-based algorithm, which is able to solve complex systems of linear equations. Theoretical analysis is given to highlight the basic features of our new algorithm. Four variants of our algorithm were also implemented and intensively tested on randomly generated full and sparse matrices and real-life problems. The results of numerical experiments reveal that our ABS-based algorithm is able to compute the solution with high accuracy. The performance of our algorithm was compared with a commercially available software, Matlab’s mldivide (\) algorithm. Our algorithm outperformed the Matlab algorithm in most cases in terms of computational accuracy. These results expand the practical usefulness of our algorithm.
Fuzzy Differential Subordinations Obtained Using a Hypergeometric Integral Operator
Authors: Oros Georgia Irina
Published: October 2021

This paper is related to notions adapted from fuzzy set theory to the field of complex analysis, namely fuzzy differential subordinations. Using the ideas specific to geometric function theory from the field of complex analysis, fuzzy differential subordination results are obtained using a new integral operator introduced in this paper using the well-known confluent hypergeometric function, also known as the Kummer hypergeometric function. The new hypergeometric integral operator is defined by choosing particular parameters, having as inspiration the operator studied by Miller, Mocanu and Reade in 1978. Theorems are stated and proved, which give corollary conditions such that the newly-defined integral operator is starlike, convex and close-to-convex, respectively. The example given at the end of the paper proves the applicability of the obtained results.
Interconnections between Content Knowledge and Pedagogical Content Knowledge of a University Lecturer in Linear Algebra
Authors: Vasco-Mora Diana , Climent-Rodríguez Nuria , Escudero-Ávila Dinazar
Published: October 2021

The aim of this study is to deepen our understanding of the practice of a lecturer in linear algebra by exploring the connections he makes between his content knowledge and his pedagogical content knowledge while working on the topic of matrices. Data were collected through video recordings of his classes and semi-structured interviews, and were analysed with the Mathematics Teacher’s Specialised Knowledge model. Instances of classroom performance, supported by the teacher’s own affirmations, provided evidence relating to the categories comprising the model, and enabled us to establish connections between the lecturer’s knowledge, his understanding of his students’ learning capabilities, and his knowledge of teaching mathematics, which together account for his classroom practice: the use of varied examples to introduce new content, the highlighting of the most salient aspects of the topic, and alerts about potential errors and difficulties. The contribution that these results could make to the training of university teachers, which would be done with the knowledge of the areas of difficulty shown by the teacher in mind, could be used to deepen other elements of their pedagogical content knowledge. The interconnections between areas of knowledge identified by the study also serve to validate the usefulness of a theoretical model for studying teachers’ knowledge.
Wavelet Modeling of Control Stochastic Systems at Complex Shock Disturbances
Authors: Sinitsyn Igor , Sinitsyn Vladimir , Korepanov Eduard , Konashenkova Tatyana
Published: October 2021

This article is devoted to the development of methodological supports and experimental software tools for accuracy analysis and information processing in control stochastic systems (CStS) with complex shock disturbances (ShD) by means of wavelet Haar–Galerkin technologies. Basic new results include methods and algorithms of stochastic covariance analysis and modeling on the basis of the Galerkin method and wavelet expansion for linear, linear with parametric noises, and quasilinear CStS with ShD. Results are illustrated by an information-control system at ShD. New stochastic effects accumulation for systematic and random errors are detected and investigated.
Multiscale Multiphysics Modeling of the Infiltration Process in the Permafrost
Authors: Stepanov Sergei , Nikiforov Djulustan , Grigorev Aleksandr
Published: October 2021

In this work, we design a multiscale simulation method based on the Generalized Multiscale Finite Element Method (GMsFEM) for numerical modeling of fluid seepage under permafrost condition in heterogeneous soils. The complex multiphysical model consists of the coupled Richards equation and the Stefan problem. These problems often contain heterogeneities due to variations of soil properties. For this reason, we design coarse-grid spaces for the multiphysical problem and design special algorithms for solving the overall problem. A numerical method has been tested on two- and three-dimensional model problems. A a quasi-real geometry with a complex surface is considered for the three-dimensional case. We demonstrate the efficiency and accuracy of the proposed method using several representative numerical results.
Could Self-Control and Emotion Influence Physical Ability and Functional Recovery after Stroke?
Authors: Choe Yu-Won , Kim Myoung-Kwon
Published: October 2021

Background and Objectives: This study was conducted to determine whether self-control and emotions could influence patients’ physical ability and functional recovery after stroke. Materials and Methods: Twenty-four patients within eight weeks after a stroke were included in this study (age: 54.04 ± 10.31; days after stroke: 42.66 ± 8.84). The subjects participated in tests at the baseline, four weeks later, and eight weeks later. Subjects were asked to complete the following: (1) self-control level test, (2) positive and negative emotion test, (3) knee muscle strength testing, (4) static balance test, (5) gait measurement, and (6) activities of daily living evaluation. Results: The muscle strength of the knee, static balance, gait ability, and the Functional Independence Measure score increased significantly in the stroke patients over time. A significant correlation was noted between the emotion and physical variables in stroke patients. The self-control level was significantly associated with the change in the physical variables in stroke patients over time. Conclusions: The self-control level was positively related to the increases in functional recovery of stroke patients with time, while the emotions were related more to the physical abilities.
A Seroprevalence Study of Anti-SARS-CoV-2 Antibodies in Patients with Inflammatory Bowel Disease during the Second Wave of the COVID-19 Pandemic in Italy
Authors: Di Ruscio Mirko , Lunardi Gianluigi , Buonfrate Dora , Gobbi Federico , Bertoli Giulia , Piccoli Donatella , Conti Antonio , Geccherle Andrea , Variola Angela
Published: October 2021

Background and Objectives: Studies have shown a lower prevalence of anti-SARS-CoV-2 antibodies in patients with inflammatory bowel disease (IBD), including amongst those receiving biological therapy. Aims were to determine the seroprevalence of anti-SARS-CoV-2 antibodies in IBD patients and to assess any association between seropositivity and IBD characteristics. Materials and Methods: Serum from adult IBD patients was prospectively collected between December 2020 and January 2021 and analyzed for anti-SARS-CoV-2 antibodies. Information about IBD characteristics and SARS-CoV-2 exposure risk factors was collected and analyzed. Serum from non-IBD healthcare workers formed the control group. Results: 311 IBD patients on biologics and 75 on mesalazine were enrolled. Ulcerative colitis (UC) extension (p < 0.001), Crohn’s disease (CD) phenotype (p = 0.009) and use of concomitant corticosteroids (p < 0.001) were significantly different between the two IBD groups. Overall seroprevalence among IBD patients was 10.4%. The control group showed a prevalence of 13.0%, not significantly different to that of IBD patients (p = 0.145). Only a close contact with SARS-CoV-2 positive individuals and the use of non-FFP2 masks were independently associated with a higher likelihood of seropositivity amongst IBD patients. Conclusion: In IBD patients, the prevalence of anti-SARS-CoV-2 antibodies is not determined by their ongoing treatment. Disease-related characteristics are not associated with a greater risk of antibody seropositivity.
Polymorphism in Gene for ABCC2 Transporter Predicts Methotrexate Drug Survival in Patients with Psoriasis
Authors: Grželj Jasna , Marovt Maruška , Marko Pij B. , Mlinarič-Raščan Irena , Gmeiner Tanja , Šmid Alenka
Published: October 2021

Background and Objectives: Methotrexate is widely prescribed for the treatment of moderate-to-severe psoriasis. As drug survival encompasses efficacy, safety, and treatment satisfaction, such studies provide insights into successful drug treatments in the real-life scenario. The objective was to define methotrexate drug survival and reasons for discontinuation, along with factors associated with drug survival, in a cohort of adult patients with moderate-to-severe plaque psoriasis. Materials and Methods: Data on methotrexate treatment were extracted from our institutional registry. Drug survival was estimated by Kaplan–Meier analysis, and predictors of drug survival were analyzed by Cox proportional hazards regression. Results: We included 133 patients treated with methotrexate. Due to significant effects of the year of treatment initiation, drug survival analysis was performed for 117 patients who started methotrexate in 2010 or later. Median methotrexate drug survival was 11.0 months. Overall, 89% of patients discontinued treatment, with over half of these (51%) due to lack of efficacy. Significantly longer drug survival was seen for patients who discontinued treatment due to lack of efficacy versus drug safety (p = 0.049); when stratified by sex, this remained significant only for women (p = 0.002). The patient ABCC2 rs717620 genotype was significantly associated with drug survival in both univariate log-rank and multivariate Cox regression analyses, with variant T allele associated with longer drug survival (hazard ratio, 0.606; 95% confidence interval, 0.380–0.967; p = 0.036). Conclusions: We have identified the novel association of patient ABCC2 rs717620 genotype with methotrexate drug survival. This pharmacogenetic marker might thus help in the management of psoriasis patients in daily practice.
Spontaneous Spine Fracture in Patient with Ankylosing Spondylitis under Spinal Anesthesia: A Case Report and Review of the Literature
Authors: Jeung Ul-Oh , Joo Dae-Chang , Kim Sung-Kyu , Im Chae-Jin
Published: October 2021

Factures in ankylosing spondylitis (AS) patients tend to occur due to the absence of motion between vertebrae, poor bone quality, and a long lever arm that generates extension force. However, most patients have a history of at least minor trauma. The aim of this report was that a vertebral fracture in a patient with AS can be caused not only by minor trauma, but also by position changes or maintenance of position for examination due to structural weakness. A 75-year-old woman with AS visited her local hospital on foot for back pain. She usually had back pain. However, she had increased back pain after falling over three weeks prior. In plain radiographs, no fracture was apparent. The doctor tried to perform magnetic resonance imaging (MRI) for further evaluation. However, several attempts of MRI failed due to continuous movement arising from pain. As a result, MRI was performed under spinal anesthesia for pain control. However, complete paraplegia developed during the MRI examination. MRI showed extension-type vertebral fracture with displacement and the patient was transferred to our hospital. We performed emergency posterior fusion, but neurological symptoms did not improve. This case suggests the need for careful positioning, sedation, or anesthesia when performing an examination or surgery in AS patients. We recommend that all patients with AS should be carefully positioned at all times during testing or surgery.
Transcatheter Arterial Embolization for Spontaneous Hepatic Rupture Associated with HELLP Syndrome: A Case Report
Authors: Nam In-Chul , Won Jung-Ho , Kim Sungbin , Bae Kyungsoo , Jeon Kyung-Nyeo , Moon Jin-Il , Cho Eun , Park Ji-Eun , Jang Jae-Yool , Park Sung-Eun
Published: October 2021

Background: Spontaneous hepatic rupture associated with the syndrome characterized by hemolysis, elevated liver enzymes, and a low platelet count (HELLP syndrome) is a rare and life-threatening condition, and only a few cases regarding the management of this condition through transcatheter arterial embolization (TAE) have been previously reported. Case summary: Herein, we report a case involving a 35-year-old pregnant woman who presented at 28 weeks of gestation with right upper quadrant pain, hypotension, and elevated levels of liver enzymes. Transabdominal ultrasound revealed fetal death. She required an emergency cesarean section, and hepatic rupture was identified after the fetus had been delivered. Hepatic packing and TAE were performed. The postprocedural course was uneventful, and the patient was discharged 14 days after she had been admitted to our hospital. Conclusions: Spontaneous hepatic rupture associated with HELLP syndrome is a very serious condition that requires prompt and decisive management. The high maternal and fetal mortality rates associated with this condition can be reduced through early accurate diagnosis and adequate management. The findings in the reported case indicate that TAE may be an attractive alternative to surgery for the management of spontaneous hepatic rupture associated with HELLP syndrome.
Percutaneous Navigation under Local Anesthesia for Computed Tomography-Guided Microwave Ablation of Malignant Liver Lesions Located in the Hepatic Dome
Authors: Filippiadis Dimitrios K. , Velonakis Georgios , Mazioti Argyro , Tsochatzis Athanasios , Vrachliotis Thomas , Kelekis Alexis , Kelekis Nikolaos
Published: October 2021

Background and Objectives: The aim of the present study was to report the safety and efficacy of percutaneous navigation under local anesthesia for computed tomography-guided microwave ablation of malignant liver lesions located in the hepatic dome. Patients with primary and secondary malignant liver lesions located in the hepatic dome who underwent percutaneous computed tomography-guided microwave ablation using a computer-assisted navigation system under local anesthesia were prospectively evaluated. The primary objective was technical success. Materials and Methods: The sample consisted of 10 participants (16 lesions) with a mean age of 60.60 years (SD = 9.25 years) and a mean size of 20.37 ± 7.29 cm, and the mean follow-up time was 3.4 months (SD = 1.41) months. Results: Primary technical success was 93.75%. Tumor remnant was noticed at one month follow-up in a single metastatic lesion, which was re-treated with an ablation session, and no tumor remnant was depicted in the subsequent imaging follow-up (secondary technical success 100%). Grade I self-limited complications (according to the CIRSE classification system) included small pleural effusion (n = 1) and minor bleeding post antenna removal (n = 1) requiring nothing but observation. Conclusions: the findings of the present study indicate that percutaneous navigation under local anesthesia is a safe and efficacious approach for computed tomography-guided microwave ablation of malignant liver lesions located in the hepatic dome. Large randomized controlled studies are warranted to observe treatment effectiveness and compare the results with those of other options.
ENT Residents Benefit from a Structured Operation Planning Approach in the Training of Functional Endoscopic Sinus Surgery
Authors: Becker Sven , Gonser Phillipp , Haas Magnus , Sailer Martin , Froelich Matthias F. , Betz Christian , Löwenheim Hubert , Hirt Bernhard , Sommer Wieland H. , Holderried Martin , Ernst Benjamin P.
Published: October 2021

Background and Objectives: Preoperative planning utilizing computed tomographies (CT) is of utmost importance in functional endoscopic sinus surgery (FESS). Frequently, no uniform documentation and planning structures are available to residents in training. Consequently, overall completeness and quality of operation planning may vary greatly. The objective of the present study was to evaluate the impact of a structured operation planning (SOP) approach on the report quality and user convenience during a 4-day sinus surgery course. Materials and Methods: Fifteen participant were requested to plan a FESS procedure based on a CT scan of the paranasal sinuses that exhibited common pathological features, in a conventional manner, using a free text. Afterwards, the participants reevaluated the same scans by means of a specifically designed structured reporting template. Two experienced ENT surgeons assessed the collected conventional operation planning (COP) and SOP methods independently with regard to time requirements, overall quality, and legibility. User convenience data were collected by utilizing visual analogue scales. Results: A significantly greater time expenditure was associated with SOPs (183 s vs. 297 s, p = 0.0003). Yet, legibility (100% vs. 72%, p < 0.0001) and overall completeness (61.3% vs. 22.7%, p < 0.0001) of SOPs was significantly superior to COPs. Additionally, description of highly relevant variants in anatomy and pathologies were outlined in greater detail. User convenience data delineated a significant preference for SOPs (VAS 7.9 vs. 6.9, p = 0.0185). Conclusions: CT-based planning of FESS procedures by residents in training using a structured approach is more time-consuming while producing a superior report quality in terms of detailedness and readability. Consequently, SOP can be considered as a valuable tool in the process of preoperative evaluations, especially within residency.
Clinical Characteristics of Actinomyces viscosus Bacteremia
Authors: Hsiao Yi-Chun , Lee Yi-Hsuan , Ho Chun-Mei , Tseng Chien-Hao , Wang Jui-Hsing
Published: October 2021

Background and Objectives: Actinomyces species are part of the normal flora of humans and rarely cause disease. It is an uncommon cause of disease in humans. The clinical features of actinomycosis have been described, and various anatomical sites (such as face, bones and joints, respiratory tract, genitourinary tract, digestive tract, central nervous system, skin, and soft tissue structures) can be affected. It is not easy to identify actinomycosis because it sometimes mimics cancer due to under-recognition. As new diagnostic methods have been applied, Actinomyces can now more easily be identified at the species level. Recent studies have also highlighted differences among Actinomyces species. We report a case of Actinomyces viscosus bacteremia with cutaneous actinomycosis. Materials and Methods: A 66 years old male developed fever for a day with progressive right lower-leg erythematous swelling. Blood culture isolates yielded Actinomyces species, which was identified as Actinomyces viscosus by sequencing of the 16S rRNA gene. In addition, we searched for the term Actinomyces or actinomycosis cross-referenced with bacteremia or “blood culture” or “blood stream” from January 2010 to July 2020. The infectious diseases caused by species of A. viscosus from January 1977 to July 2020 were also reviewed. Results: The patient recovered well after intravenous ampicillin treatment. Poor oral hygiene was confirmed by dental examination. There were no disease relapses during the following period. Most cases of actinomycosis can be treated with penicillin. However, clinical alertness, risk factor evaluation, and identification of Actinomyces species can prevent inappropriate antibiotic or intervention. We also compiled a total of 18 cases of Actinomyces bacteremia after conducting an online database search. Conclusions: In summary, we describe a case of fever and progressive cellulitis. Actinomyces species was isolated from blood culture, which was further identified as Actinomyces viscosus by 16S rRNA sequencing. The cellulitis improved after pathogen-directed antibiotics. Evaluation of risk factors in patients with Actinomyces bacteremia and further identification of the Actinomyces species are recommended for successful treatment.
The Outcomes of Enamel Matrix Derivative on Periodontal Regeneration under Diabetic Conditions
Authors: Narita Laura Elena , Mester Alexandru , Onisor Florin , Bran Simion , Onicas Maria Ioana , Voina-Tonea Andrada
Published: October 2021

Background and Objectives: Enamel matrix derivative (EMD) is a biomaterial used for periodontal regenerative therapy due to its properties of stimulating cementum development and bone synthesis. Diabetes is a chronic condition that affects healing and predisposes to infection. The aim of this review was to evaluate the current studies available on the application and results of EMD for periodontal regenerative therapy under diabetic conditions. Materials and Methods: Five databases (PubMed, ResearchGate, Scopus, Web of Science and Google Scholar) were searched for relevant articles, using specific keywords in different combinations. The inclusion criteria were clinical trials, case reports, case studies, and animal studies published in English, where periodontal treatment for bone defects includes EMD, and it is performed under diabetic conditions. Results: Of the 310 articles resulted in search, five studies published between 2012 and 2020 met the inclusion criteria and were selected for the current review. In human studies, the use of EMD in infrabony defects showed favorable results at follow-up. In animal studies, periodontal regeneration was reduced in diabetic rats. Conclusions: EMD might promote bone healing when used under diabetic conditions for the regenerative periodontal therapy. Due to limited number of studies, more data are required to sustain the effects of EMD therapy in diabetic settings.
The Psychosocial Role of Body Image in the Quality of Life of Head and Neck Cancer Patients. What Does the Future Hold?—A Review of the Literature
Authors: Covrig Vlad Ioan , Lazăr Diana Elena , Costan Victor Vlad , Postolică Roxana , Ioan Beatrice Gabriela
Published: October 2021

Background and Objectives: It is well known that among all cancers, cancers of the head and neck (HNC) have a major impact on patients’ quality of life. Disfigurement, anxiety and disabling physical and psychological symptoms affect people with HNC to such an extent that the suicide rate in this category of patients is exceeded only by that of patients with pancreatic cancer. The aim of this review was to summarize the published literature describing the severity of body image and quality of life impairment in patients with HNC over time, and to examine the psychosocial and functional associations and interventions implemented to improve body image and quality of life. Materials and Methods: We conducted a literature search from 1 January 2018 to June 2021 that included electronic searches of six major databases (PubMed, ScienceDirect, ProQuest, PsycINFO, PsychArticles and Scopus) and review of references of articles screened. Of 620 records, only 9 articles met the eligibility criteria. Results: Numerous studies have been conducted to analyze various psychological variables, but there is still a lack of standardization in the assessment of body image perception (BI) and quality of life, resulting in small-scale testing of interventions with poor results. Conclusions: Expected longitudinal studies describing the flow of body image problems and the mediation and balance factors associated with body image will allow researchers to design methods aimed at limiting body image disorders and thus improving quality of life of patients with head and neck cancer.
Effect of Vitamin D Supplementation on Muscle Status in Old Patients Recovering from COVID-19 Infection
Authors: Caballero-García Alberto , Pérez-Valdecantos Daniel , Guallar Pablo , Caballero-Castillo Aurora , Roche Enrique , Noriega David C. , Córdova Alfredo
Published: October 2021

Background and Objectives: Vitamin D, in addition to its effect on mineral homeostasis, plays a key role in muscle metabolism. Vitamin D supplementation is involved in muscle recovery after damage as a consequence of either pathology or after high-intensity exercise. In this context, the aim of this study was to analyze the effect of vitamin D on muscle fitness in elderly patients in the recovery phase after SARS-CoV-2 (COVID-19) infection. Materials and Methods: This pilot study was conducted at the Soria Norte Health Center. The study consisted of a double-blind trial with two groups of men (placebo and vitamin D-supplemented) (n = 15/group). Treatment with vitamin D (cholecalciferol: 2000 IU/day) and placebo was carried out for 6 weeks. Circulating hematological and biochemical parameters (total protein, glucose, vitamin D, urea, uric acid, aspartate aminotransferase/glutamic-oxaloacetic transaminase, alanine aminotransferase/glutamic-pyruvic transaminase, creatine kinase, lactate dehydrogenase, aldolase, gamma-glutamyl transferase and myoglobin) and the hormones cortisol and testosterone were determined. As for respiratory function tests, FEV1 and respiratory flow were also studied. For physical fitness tests, the “six-minute walk test” (6MWT) was used. Results: After vitamin D supplementation, we observed that serum creatine kinase levels returned to optimal values. This change suggests a protective role of vitamin D against muscle catabolism compared to placebo. In terms of physical test results, we observed only slight non-significant improvements, although patients reported feeling better. Conclusions: Vitamin D supplementation produces decreases in indicators of muscle damage, which may ultimately contribute to improving the health status and quality of life of patients who have suffered from COVID-19, during the recovery process.
Microbiome Changes after Type 2 Diabetes Treatment: A Systematic Review
Authors: Merkevičius Kajus , Kundelis Ričardas , Maleckas Almantas , Veličkienė Džilda
Published: October 2021

Background and objectives: Although the role of the gut microbiome in type 2 diabetes (T2D) pathophysiology is evident, current systematic reviews and meta-analyses analyzing T2D treatment mainly focus on metabolic outcomes. The objective of this study is to evaluate the microbiome and metabolic changes after different types of treatment in T2D patients. Materials and Methods: A systematic search of PubMed, Wiley online library, Science Direct, and Cochrane library electronic databases was performed. Randomized controlled clinical trials published in the last five years that included T2D subjects and evaluated the composition of the gut microbiome alongside metabolic outcomes before and after conventional or alternative glucose lowering therapy were selected. Microbiome changes were evaluated alongside metabolic outcomes in terms of bacteria taxonomic hierarchy, intestinal flora biodiversity, and applied intervention. Results: A total of 16 eligible studies involving 1301 participants were reviewed. Four trials investigated oral glucose-lowering treatment, three studies implemented bariatric surgery, and the rest analyzed probiotic, prebiotic, or synbiotic effects. The most common alterations were increased abundance of Firmicutes and Proteobacteria parallel to improved glycemic control. Bariatric surgery, especially Roux-en-Y gastric bypass, led to the highest variety of changed bacteria phyla. Lower diversity post-treatment was the most significant biodiversity result, which was present with improved glycemic control. Conclusions: Anti-diabetic treatment induced the growth of depleted bacteria. A gut microbiome similar to healthy individuals was achieved during some trials. Further research must explore the most effective strategies to promote beneficial bacteria, lower diversity, and eventually reach a non-T2D microbiome.
The Role of Contrast-Enhanced Harmonic Endoscopic Ultrasound in Interventional Endoscopic Ultrasound
Authors: Binda Cecilia , Coluccio Chiara , Marocchi Gianmarco , Sbrancia Monica , Fabbri Carlo
Published: October 2021

Over the last decades, contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) has emerged as an important diagnostic tool for the diagnosis and differentiation of several gastrointestinal diseases. The key advantage of CH-EUS is that the influx and washout of contrast in the target lesion can be observed in real time, accurately depicting microvasculature. CH-EUS is established as an evidence-based technique complementary to B-mode EUS to differentiate solid appearing structures, to characterize mass lesions, and to improve the staging of gastrointestinal and pancreatobiliary cancer. In the last few years, interest has increased in the use of CH-EUS in interventional procedures such as tissue acquisition, tumor ablation, biliary drainage, and the management of pancreatic fluid collections. The aim of this narrative review is to evaluate the available evidence and future expectations of CH-EUS in interventional EUS.
Transfer of Gold, Platinum and Non-Ferrous Metals from Matte to Slag by Flotation
Authors: Amdur Alexey M. , Fedorov Sergei A. , Yurak Vera V.
Published: October 2021

One of the stages of extracting gold and platinum from sulfide materials and circulating slags is the melting stage in ore-thermal and electric furnaces, where the melt is separated into matte and slag. Gold, platinum, and non-ferrous metals are concentrated in the matte. However, a significant portion of them ends up in the slag, which reduces recovery and increases environmental pollution. The main reason for their transition to slag is the flotation of sulfide droplets by gas bubbles, a significant proportion of which occurs during the decomposition of sulfides. Gold and platinum are associated with matte droplets during flotation. Evaluation of adhesion showed that it is large and comparable to the cohesion of these metals. One of the options to reduce the loss of valuable components is to add fluxes to the slag. The influence of calcite and fluorite on the distribution of gold and platinum over the melting products of copper–nickel sulfide materials (matte and slag) has been experimentally studied based on the above theoretical concepts of droplet flotation. When calcite was added to sulfide ore, there was a significant decrease in the sulfur content in the slag (more than 3 times). This, in turn, led to a decrease in non-ferrous metals in the slag by 2–3 times, with gold from 0.45 to 0.29 g/t and platinum from 2.15 to 2.06 g/t. The addition of fluorite to the mixture of copper–nickel matte and model slag (CaO/SiO2/Al2O3 = 40/40/20) significantly reduced the sulfur content and non-ferrous metals by 1.5 times, whereas gold was not found in the slag. The decrease in the number of sulfides in the slag is mainly because the listed additives reduce its viscosity. This leads to acceleration of the coagulation of sulfide drops, which are inevitably carried into the slag during flotation, and increases the rate of their settling to the slag–matte boundary, where they merge with the matte mass.
Immunoglobulin A, an Active Liaison for Host-Microbiota Homeostasis
Authors: Abokor Ahmed A. , McDaniel Grant H. , Golonka Rachel M. , Campbell Connor , Brahmandam Sreya , Yeoh Beng San , Joe Bina , Vijay-Kumar Matam , Saha Piu
Published: October 2021

Mucosal surfaces in the gastrointestinal tract are continually exposed to native, commensal antigens and susceptible to foreign, infectious antigens. Immunoglobulin A (IgA) provides dual humoral responses that create a symbiotic environment for the resident gut microbiota and prevent the invasion of enteric pathogens. This review features recent immunological and microbial studies that elucidate the underlying IgA and microbiota-dependent mechanisms for mutualism at physiological conditions. IgA derailment and concurrent microbiota instability in pathological diseases are also discussed in detail. Highlights of this review underscore that the source of IgA and its structural form can dictate microbiota reactivity to sustain a diverse niche where both host and bacteria benefit. Other important studies emphasize IgA insufficiency can result in the bloom of opportunistic pathogens that encroach the intestinal epithelia and disseminate into circulation. The continual growth of knowledge in these subjects can lead to the development of therapeutics targeting IgA and/or the microbiota to treat life threatening diseases.
Sex-Specific Associations between Gut Microbiome and Non-Alcoholic Fatty Liver Disease among Urban Chinese Adults
Authors: Shi Jiajun , Yang Yaohua , Xu Wanghong , Cai Hui , Wu Jie , Long Jirong , Cai Qiuyin , Zheng Wei , Flynn Charles R. , Shu Xiao-Ou , Yu Danxia
Published: October 2021

Non-alcoholic fatty liver disease (NAFLD) has been linked to altered gut microbiome; however, evidence from large population-based studies is limited. We compared gut microbiome profiles of 188 male and 233 female NAFLD cases with 571 male and 567 female controls from two longitudinal studies of urban Chinese adults. History of NAFLD was assessed during surveys administered in 2004–2017. Microbiota were assessed using 16S rRNA sequencing of stool samples collected in 2015–2018. Associations of NAFLD with microbiome diversity and composition were evaluated by generalized linear or logistic regression models. Compared with controls, male cases had lower microbial α-diversity, higher abundance of genera Dialister and Streptococcus and Bifidobacterium species, lower abundance of genus Phascolarctobacterium, and lower prevalence of taxa including order RF39 (all p < 0.05). In contrast, female cases had higher α-diversity, higher abundance of genus Butyricimonas and a family of order Clostridiales, lower abundance of Dialister and Bifidobacterium species, and higher prevalence of RF39. Significant NAFLD–sex interactions were found for α-diversity and above taxa (all false discovery rate < 0.1). In conclusion, we observed sex-specific gut microbiome features related to history of NAFLD. Further studies are needed to validate our findings and evaluate the health effects of NAFLD-related gut microbiota.