bluuebunny/crossref_metadata_2025 huggingface dataset:
Integral Formulas for Almost Product Manifolds and Foliations
Authors: Rovenski Vladimir
Published: October 2022

Integral formulas are powerful tools used to obtain global results in geometry and analysis. The integral formulas for almost multi-product manifolds, foliations and multiply twisted products of Riemannian, metric-affine and sub-Riemannian manifolds, to which this review paper is devoted, are useful for studying such problems as (i) the existence and characterization of foliations with a given geometric property, such as being totally geodesic, minimal or totally umbilical; (ii) prescribing the generalized mean curvatures of the leaves of a foliation; (iii) minimizing volume-like functionals defined for tensors on foliated manifolds. We start from the series of integral formulas for codimension one foliations of Riemannian and metric-affine manifolds, and then we consider integral formulas for regular and singular foliations of arbitrary codimension. In the second part of the article, we represent integral formulas with the mixed scalar curvature of an almost multi-product structure on Riemannian and metric-affine manifolds, give applications to hypersurfaces of space forms with k=2,3 distinct principal curvatures of constant multiplicities and then discuss integral formulas for foliations or distributions on sub-Riemannian manifolds.
MS-CheXNet: An Explainable and Lightweight Multi-Scale Dilated Network with Depthwise Separable Convolution for Prediction of Pulmonary Abnormalities in Chest Radiographs
Authors: Shetty Shashank , S. Ananthanarayana V , Mahale Ajit
Published: October 2022

Pulmonary diseases are life-threatening diseases commonly observed worldwide, and timely diagnosis of these diseases is essential. Meanwhile, increased use of Convolution Neural Networks has promoted the advancement of computer-assisted clinical recommendation systems for diagnosing diseases using chest radiographs. The texture and shape of the tissues in the diagnostic images are essential aspects of prognosis. Therefore, in the latest studies, the vast set of images with a larger resolution is paired with deep learning techniques to enhance the performance of the disease diagnosis in chest radiographs. Moreover, pulmonary diseases have irregular and different sizes; therefore, several studies sought to add new components to existing deep learning techniques for acquiring multi-scale imaging features from diagnostic chest X-rays. However, most of the attempts do not consider the computation overhead and lose the spatial details in an effort to capture the larger receptive field for obtaining the discriminative features from high-resolution chest X-rays. In this paper, we propose an explainable and lightweight Multi-Scale Chest X-ray Network (MS-CheXNet) to predict abnormal diseases from the diagnostic chest X-rays. The MS-CheXNet consists of four following main subnetworks: (1) Multi-Scale Dilation Layer (MSDL), which includes multiple and stacked dilation convolution channels that consider the larger receptive field and captures the variable sizes of pulmonary diseases by obtaining more discriminative spatial features from the input chest X-rays; (2) Depthwise Separable Convolution Neural Network (DS-CNN) is used to learn imaging features by adjusting lesser parameters compared to the conventional CNN, making the overall network lightweight and computationally inexpensive, making it suitable for mobile vision tasks; (3) a fully connected Deep Neural Network module is used for predicting abnormalities from the chest X-rays; and (4) Gradient-weighted Class Activation Mapping (Grad-CAM) technique is employed to check the decision models’ transparency and understand their ability to arrive at a decision by visualizing the discriminative image regions and localizing the chest diseases. The proposed work is compared with existing disease prediction models on chest X-rays and state-of-the-art deep learning strategies to assess the effectiveness of the proposed model. The proposed model is tested with a publicly available Open-I Dataset and data collected from a private hospital. After the comprehensive assessment, it is observed that the performance of the designed approach showcased a 7% to 18% increase in accuracy compared to the existing method.
A New Low-Rank Structurally Incoherent Algorithm for Robust Image Feature Extraction
Authors: Ge Hongmei , Song Aibo
Published: October 2022

In order to solve the problem in which structurally incoherent low-rank non-negative matrix decomposition (SILR-NMF) algorithms only consider the non-negativity of the data and do not consider the manifold distribution of high-dimensional space data, a new structurally incoherent low rank two-dimensional local discriminant graph embedding (SILR-2DLDGE) is proposed in this paper. The algorithm consists of the following three parts. Firstly, it is vital to keep the intrinsic relationship between data points. By the token, we introduced the graph embedding (GE) framework to preserve locality information. Secondly, the algorithm alleviates the impact of noise and corruption uses the L1 norm as a constraint by low-rank learning. Finally, the algorithm improves the discriminant ability by encrypting the structurally incoherent parts of the data. In the meantime, we capture the theoretical basis of the algorithm and analyze the computational cost and convergence. The experimental results and discussions on several image databases show that the proposed algorithm is more effective than the SILR-NMF algorithm.
A Game Theoretic Model of Struggle with Corruption in Auctions: Computer Simulation
Authors: Kozlov Kirill , Ougolnitsky Guennady
Published: October 2022

There is a great deal of literature devoted to mathematical models of corruption, including corruption in auctions. However, the relationship between the seller and the auctioneer is not studied sufficiently. The research aim is to analyze such relations in a game theoretic setup. We built a difference game theoretic model in normal form that describes possible collusion between an auctioneer and participants of an auction. The auctioneer acts on behalf of a seller. The seller can control possible collusions by administrative and economic mechanisms. The probability of detection depends on audit cost. We consider four cases of absence/presence of the collusion and those of the audit. The model is investigated numerically by simulation modeling using an original method of qualitatively representative scenarios. Several conclusions are made: factors of corruption are low probability of detection, small penalty, and big corruption gain of the auctioneer.
Growth Recovery and COVID-19 Pandemic Model: Comparative Analysis for Selected Emerging Economies
Authors: Akaev Askar , Zvyagintsev Alexander I. , Sarygulov Askar , Devezas Tessaleno , Tick Andrea , Ichkitidze Yuri
Published: October 2022

The outburst of the COVID-19 pandemic and its rapid spread throughout the world in 2020 shed a new light on mathematic models describing the nature of epidemics. However, as the pandemic shocked economies to a much greater extent than earlier epidemics, the recovery potential of economies was emphasized and its inclusion in epidemic models is becoming more important. The present paper deals with the issues of modeling the recovery of economic systems that have undergone severe medical shocks, such as COVID-19. The proposed mathematical model considers the close relationship between the dynamics of pandemics and economic development. This distinguishes it from purely “medical” models, which are used exclusively to study the dynamics of the spread of the COVID-19 pandemic. Unlike standard SIR models, the present approach involves the introduction of the “vaccine” equation to the SIR model and introduces correction components that include the possibility of re-infection and other nuances such as the number of people at risk of infection (not sick with COVID but not vaccinated); sick with COVID; recovered; fully vaccinated (two doses) citizens; the rate of COVID infection; the rate of recovery of infected individuals; the vaccination coefficients, respectively, for those who have not been ill and recovered from COVID; the coefficient of revaccination; the COVID re-infection rate; and the population fluctuation coefficient, which takes into account the effect of population change as a result of births and deaths and due to the departure and return of citizens. The present model contains governance so that it not only generates scenario projections but also models specific governance measures as well to include the pandemic and restore economic growth. The model also adds management issues, so that it not only generates scenario forecasts but simultaneously models specific management measures as well, aiming to suppress the pandemic and restoring economic growth. The model was implemented on specific data on the dynamics of the spread of the COVID-19 pandemic in selected developing economies.
Transient and Quasi-Steady-State Analytical Methods for Simulating a Vertical Gas Flow in a Landfill with Layered Municipal Solid Waste
Authors: Wu Xun , Shi Jianyong , Zhang Tao , Li Yuping , Shu Shi
Published: October 2022

The exploration of gas pressure and its distribution in landfills is a principal concern for the design and management of municipal solid waste (MSW) landfills. A one-dimensional analytical model was proposed to simulate a vertical gas flow in a landfill with layered MSWs. The transient analytical solution was obtained by the method of superposition and eigenfunction expansion and verified by a semi-analytical solution and numerical simulation. According to the results of a parametric analysis by the transient analytical solution, a vertical gas flow in landfills can be simplified to a quasi-steady-state flow. A quasi-steady-state analytical solution for simulating a vertical gas flow in a landfill with layered MSW is proposed. The quasi-steady-state analytical solution showed good agreement with the transient solution. Both temporal and spatial variations of the gas generation rate in MSW landfills were considered in the transient and quasi-steady-state analytical methods. A comparison between the proposed quasi-steady-state solution and the previously described steady-state solution showed that using the average gas generation rate or the gas generation rate corresponding to the average age of the MSW layer in the steady-state solution resulted in an error in the estimation of the gas pressure in landfills. The proposed solutions are reliable and can provide a reference for the design, management, and subsequent restoration of landfills.
Defects Classification of Hydro Generators in Indonesia by Phase-Resolved Partial Discharge
Authors: Lee Chun-Yao , Purba Nando , Zhuo Guang-Lin
Published: October 2022

This paper proposed a phase-resolved partial discharge (PRPD) shape method to classify types of defect generator units by using offline partial discharge (PD) measurement instruments. In this paper, the experimental measurement was applied to two generators in the Inalum hydropower plant, located in North Sumatera, Indonesia. The recorded PRPD using the instrument MPD600 can illustrate the PRPD patterns of generator defects. The proposed PRPD shape method is used to mark auxiliary lines on the PRPD patterns. Moreover, four types of defects refer to the IEC 60034-27 standard, which are microvoid (S1), delamination tape layer (S2), slot defect (S3), and internal delamination (S4) and are used to classify the defect types of the generators. The results show that the proposed method performs well to classify types of defect generator units.
What Drives Economic Growth across European Countries? A Multimodal Approach
Authors: Batrancea Larissa M. , Balcı Mehmet Ali , Akgüller Ömer , Gaban Lucian
Published: October 2022

This research study examines the factors that determined economic growth measured by gross domestic product, gross value added, final consumption expenditure of households, and gross fixed capital formation across a sample of 36 European countries during the time frame Q3 2018−Q3 2021. We conducted a panel data analysis with the first-difference generalized method of moments (GMM) approach and cross-section fixed effects. Empirical results estimated with four econometric models indicated a significant robust impact of the independent variables exports, imports, foreign direct investment inflow, foreign direct investment outflow, social contributions, and wages on economic growth proxies. In addition, multiplex network analysis was used to investigate the connection architectures of the 36 countries, and it yielded statistical measurements for all layers in the multi-layered structure. Relevant policy implications of reported empirical results are also addressed.
A Reverse Positional Encoding Multi-Head Attention-Based Neural Machine Translation Model for Arabic Dialects
Authors: Baniata Laith H. , Kang Sangwoo , Ampomah Isaac. K. E.
Published: October 2022

Languages with a grammatical structure that have a free order for words, such as Arabic dialects, are considered a challenge for neural machine translation (NMT) models because of the attached suffixes, affixes, and out-of-vocabulary words. This paper presents a new reverse positional encoding mechanism for a multi-head attention (MHA) neural machine translation (MT) model to translate from right-to-left texts such as Arabic dialects (ADs) to modern standard Arabic (MSA). The proposed model depends on an MHA mechanism that has been suggested recently. The utilization of the new reverse positional encoding (RPE) mechanism and the use of sub-word units as an input to the self-attention layer improve this sublayer for the proposed model’s encoder by capturing all dependencies between the words in right-to-left texts, such as AD input sentences. Experiments were conducted on Maghrebi Arabic to MSA, Levantine Arabic to MSA, Nile Basin Arabic to MSA, Gulf Arabic to MSA, and Iraqi Arabic to MSA. Experimental analysis proved that the proposed reverse positional encoding MHA NMT model was efficiently able to handle the open grammatical structure issue of Arabic dialect sentences, and the proposed RPE MHA NMT model enhanced the translation quality for right-to-left texts such as Arabic dialects.
On the Dynamics of New 4D and 6D Hyperchaotic Systems
Authors: Rezzag Samia , Zhang Fuchen
Published: October 2022

One of the most interesting problems is the investigation of the boundaries of chaotic or hyperchaotic systems. In addition to estimating the Lyapunov and Hausdorff dimensions, it can be applied in chaos control and chaos synchronization. In this paper, by means of the analytical optimization, comparison principle, and generalized Lyapunov function theory, we find the ultimate bound set for a new six-dimensional hyperchaotic system and the globally exponentially attractive set for a new four-dimensional Lorenz- type hyperchaotic system. The novelty of this paper is that it not only shows the 4D hyperchaotic system is globally confined but also presents a collection of global trapping regions of this system. Furthermore, it demonstrates that the trajectories of the 4D hyperchaotic system move at an exponential rate from outside the trapping zone to its inside. Finally, some numerical simulations are shown to demonstrate the efficacy of the findings.
Modified Whiteside’s Line-Based Transepicondylar Axis for Imageless Total Knee Arthroplasty
Authors: Sohail Muhammad , Park Jaehyun , Kim Jun Young , Kim Heung Soo , Lee Jaehun
Published: October 2022

One of the aims of successful total knee arthroplasty (TKA) is to restore the natural range of motion of the infected joint. The operated leg motion highly depends on the coordinate systems that have been used to prepare the bone surfaces for an implant. Assigning a perfect coordinate system to the knee joint is a considerable challenge. Various commercially available knee arthroplasty devices use different methods to assign the coordinate system at the distal femur. Transepicondylar axis (TEA) and Whiteside’s line are commonly used anatomical axes for defining a femoral coordinate system (FCS). However, choosing a perfect TEA for FCS is trickier, even for experienced surgeons, and a small error in marking Whiteside’s line leads to a misaligned knee joint. This work proposes a modified Whiteside’s line method for the selection of TEA. The Whiteside’s line, along with the knee center and femur head center, define two independent central planes. Multiple prominent points on the lateral and medial sides of epicondyles are marked. Based on the lengths of perpendicular distances between the multiple points and central planes, the most prominent epicondyle points are chosen to define an optimal TEA. Compared to conventional techniques, the modified Whiteside’s line defines a repeatable TEA
SaMfENet: Self-Attention Based Multi-Scale Feature Fusion Coding and Edge Information Constraint Network for 6D Pose Estimation
Authors: Li Zhuoxiao , Li Xiaobing , Chen Shihao , Du Jialong , Li Yong
Published: October 2022

Accurate estimation of an object’s 6D pose is one of the crucial technologies for robotic manipulators. Especially when the lighting conditions changes or the object is occluded, resulting in the missing or the interference of the object information, which makes the accurate 6D pose estimation more challenging. To estimate the 6D pose of the object accurately, a self-attention-based multi-scale feature fusion coding and edge information constraint 6D pose estimation network is proposed, which can achieve accurate 6D pose estimation by employing RGB-D images. The proposed algorithm first introduces the edge reconstruction module into the pose estimation network, which improves the attention of the feature extraction network to the edge features. Furthermore, a self-attention multi-scale point cloud feature extraction module, i.e., MSPNet, is proposed to extract point cloud geometric features, which are reconstructed from depth maps. Finally, the clustering feature encoding module, i.e., SE-NetVLAD, is proposed to encode multi-modal dense feature sequences to construct more expressive global features. The proposed method is evaluated on the LineMOD and YCB-Video datasets, and the experimental results illustrate that the proposed method has an outstanding performance, which is close to the current state-of-the-art methods.
Speeding-Up Elliptic Curve Cryptography Algorithms
Authors: Maimuţ Diana , Matei Alexandru Cristian
Published: October 2022

In recent decades there has been an increasing interest in Elliptic curve cryptography (ECC) and, especially, the Elliptic Curve Digital Signature Algorithm (ECDSA) in practice. The rather recent developments of emergent technologies, such as blockchain and the Internet of Things (IoT), have motivated researchers and developers to construct new cryptographic hardware accelerators for ECDSA. Different types of optimizations (either platform dependent or algorithmic) were presented in the literature. In this context, we turn our attention to ECC and propose a new method for generating ECDSA moduli with a predetermined portion that allows one to double the speed of Barrett’s algorithm. Moreover, we take advantage of the advancements in the Artificial Intelligence (AI) field and bring forward an AI-based approach that enhances Schoof’s algorithm for finding the number of points on an elliptic curve in terms of implementation efficiency. Our results represent algorithmic speed-ups exceeding the current paradigm as we are also preoccupied by other particular security environments meeting the needs of governmental organizations.
Energy Efficiency of a New Parallel PIC Code for Numerical Simulation of Plasma Dynamics in Open Trap
Authors: Chernykh Igor , Kulikov Igor , Vshivkov Vitaly , Genrikh Ekaterina , Weins Dmitry , Dudnikova Galina , Chernoshtanov Ivan , Boronina Marina
Published: October 2022

The generation of energy-efficient parallel scientific codes became very important in the time of carbon footprint reduction. In this paper, we briefly present our latest particle-in-cell code with the results of a numerical simulation of plasma dynamics in an open trap. This code can be auto-vectorized by the Fortran compiler for Intel Xeon processors with AVX-512 instructions such as Intel Xeon Phi and the highest series of all generations of Intel Xeon Scalable processors. Efficient use of processor architecture is the main feature of an energy-efficient solution. We present a step-by-step methodology of energy consumption calculation using Intel hardware features and Intel VTune software. We also give an estimated value of carbon footprint with the impact of high-performance water cooled hardware. The Power Usage Effectiveness (PUE) in the case of high-performance water cooled hardware is equal to 1.03–1.05, and is up to 1.3 in the case of air-cooled systems. This means that power consumption of liquid cooled systems is lower than that air-cooled ones by up to 25%. All these factors play an important role in the carbon footprint reduction problem.
HIV Dynamics with a Trilinear Antibody Growth Function and Saturated Infection Rate
Authors: Fikri Fatima Ezzahra , Allali Karam
Published: October 2022

The objective of this paper is to study a new mathematical model describing the human immunodeficiency virus (HIV). The model incorporates the impacts of cytotoxic T lymphocyte (CTL) immunity and antibodies with trilinear growth functions. The boundedness and positivity of solutions for non-negative initial data are proved, which is consistent with biological studies. The local stability of the equilibrium is established. Finally, numerical simulations are presented to support our theoretical findings.
Nitrogen Starvation Enhances the Production of Saturated and Unsaturated Fatty Acids in Aurantiochytrium sp. PKU#SW8 by Regulating Key Biosynthetic Genes
Authors: Chen Xiaohong , He Yaodong , Liu Lu , Zhu Xingyu , Sen Biswarup , Wang Guangyi
Published: October 2022

Nitrogen deprivation is known to improve lipid accumulation in microalgae and thraustochytrids. However, the patterns of fatty acid production and the molecular mechanisms underlying the accumulation of unsaturated and saturated fatty acids (SFAs) under nitrogen starvation remain largely unknown for thraustochytrids. In this study, batch culture experiments under nitrogen replete and nitrogen starvation conditions were performed, and the changes in the transcriptome of Aurantiochytrium sp. PKU#SW8 strain between these conditions were investigated. Our results showed improved yields of total fatty acids (TFAs), total unsaturated fatty acids, and total SFAs under nitrogen starvation, which suggested that nitrogen starvation favors the accumulation of both unsaturated and saturated fatty acids in PKU#SW8. However, nitrogen starvation resulted in a more than 2.36-fold increase of SFAs whereas a 1.7-fold increase of unsaturated fatty acids was observed, indicating a disproportionate increase in these groups of fatty acids. The fabD and enoyl-CoA hydratase genes were significantly upregulated under nitrogen starvation, supporting the observed increase in the yield of TFAs from 2.63 ± 0.22 g/L to 3.64 ± 0.16 g/L. Furthermore, the pfaB gene involved in the polyketide synthase (PKS) pathway was significantly upregulated under nitrogen starvation. This suggested that the increased expression of the pfaB gene under nitrogen starvation may be one of the explanations for the increased yield of docosahexaenoic acid by 1.58-fold. Overall, our study advances the current understanding of the molecular mechanisms that underlie the response of thraustochytrids to nitrogen deprivation and their fatty acid biosynthesis.
Intratympanic Administration of Dieckol Prevents Ototoxic Hearing Loss
Authors: Li Hui , Oh Seung , Shin Hyeon-Cheol , Suh Myung-Whan
Published: October 2022

Objective. Systemic administration of dieckol reportedly ameliorates acute hearing loss. In this study, dieckol was delivered to the inner ear by the intratympanic route. The functional and anatomic effects and safety of dieckol were assessed using the rat ototoxicity model. Materials and methods. Dieckol in a high-molecular-weight hyaluronic acid vehicle (dieckol+vehicle group) or vehicle without dieckol (vehicle-only group) were randomly delivered into 12 ears intratympanically. Ototoxic hearing loss was induced by intravenous administration of cisplatin, gentamicin, and furosemide. The hearing threshold and surviving outer hair cells (OHC) were enumerated. Biocompatibility was assessed by serial endoscopy of the tympanic membrane (TM), and the histology of the TM and the base of bulla (BB) mucosa was quantitatively assessed. Results. The hearing threshold was significantly better (difference of 20 dB SPL) in the dieckol+vehicle group than in the vehicle-only group. The number of surviving OHCs was significantly greater in the dieckol+vehicle group than in the vehicle-only group. There were no signs of inflammation or infection in the ear. The thickness of the TM and the BB mucosa did not differ between the two groups. Conclusion. Intratympanic local delivery of dieckol may be a safe and effective method to prevent ototoxic hearing loss.
Growth Factor-Free Vascularization of Marine-Origin Collagen Sponges Using Cryopreserved Stromal Vascular Fractions from Human Adipose Tissue
Authors: Freitas-Ribeiro Sara , Diogo Gabriela S. , Oliveira Catarina , Martins Albino , Silva Tiago H. , Jarnalo Mariana , Horta Ricardo , Reis Rui L. , Pirraco Rogério P.
Published: October 2022

The successful integration of transplanted three-dimensional tissue engineering (TE) constructs depends greatly on their rapid vascularization. Therefore, it is essential to address this vascularization issue in the initial design of constructs for perfused tissues. Two of the most important variables in this regard are scaffold composition and cell sourcing. Collagens with marine origins overcome some issues associated with mammal-derived collagen while maintaining their advantages in terms of biocompatibility. Concurrently, the freshly isolated stromal vascular fraction (SVF) of adipose tissue has been proposed as an advantageous cell fraction for vascularization purposes due to its highly angiogenic properties, allowing extrinsic angiogenic growth factor-free vascularization strategies for TE applications. In this study, we aimed at understanding whether marine collagen 3D matrices could support cryopreserved human SVF in maintaining intrinsic angiogenic properties observed for fresh SVF. For this, cryopreserved human SVF was seeded on blue shark collagen sponges and cultured up to 7 days in a basal medium. The secretome profile of several angiogenesis-related factors was studied throughout culture times and correlated with the expression pattern of CD31 and CD146, which showed the formation of a prevascular network. Upon in ovo implantation, increased vessel recruitment was observed in prevascularized sponges when compared with sponges without SVF cells. Immunohistochemistry for CD31 demonstrated the improved integration of prevascularized sponges within chick chorioalantoic membrane (CAM) tissues, while in situ hybridization showed human cells lining blood vessels. These results demonstrate the potential of using cryopreserved SVF combined with marine collagen as a streamlined approach to improve the vascularization of TE constructs.
A New Perspective: Revealing the Algicidal Properties of Bacillus subtilis to Alexandrium pacificum from Bacterial Communities and Toxins
Authors: Cheng Ruihong , Song Xiuxian , Song Weijia , Yu Zhiming
Published: October 2022

Algicidal bacteria are important in the control of toxic dinoflagellate blooms, but studies on the environmental behavior of related algal toxins are still lacking. In this study, Bacillus subtilis S3 (S3) showed the highest algicidal activity against Alexandrium pacificum (Group IV) out of six Bacillus strains. When treated with 0.5% (v/v) S3 bacterial culture and sterile supernatant, the algicidal rates were 69.74% and 70.22% at 12 h, respectively, and algicidal substances secreted by S3 were considered the mechanism of algicidal effect. During the algicidal process, the rapid proliferation of Alteromonas sp. in the phycosphere of A. pacificum may have accelerated the algal death. Moreover, the algicidal development of S3 released large amounts of intracellular paralytic shellfish toxins (PSTs) into the water, as the extracellular PSTs increased by 187.88% and 231.47% at 12 h, compared with the treatment of bacterial culture and sterile supernatant at 0 h, respectively. Although the total amount of PSTs increased slightly, the total toxicity of the algal sample decreased as GTX1/4 was transformed by S3 into GTX2/3 and GTX5. These results more comprehensively reveal the complex relationship between algicidal bacteria and microalgae, providing a potential source of biological control for harmful algal blooms and toxins.
Network Pharmacological Analysis of the Red Sea Sponge Hyrtios erectus Extract to Reveal Anticancer Efficacy of Corresponding Loaded Niosomes
Authors: Abou-Taleb Heba A. , Sayed Ahmed M. , Refaat Hesham , Alsenani Faisal , Alaaeldin Eman , Mokhtar Fatma A. , Abdelmohsen Usama Ramadan , Shady Nourhan Hisham
Published: October 2022

In this study, the LC-HRMS-assisted chemical profiling of Hyrtios erectus sponge led to the annotation of eleven major compounds (1–11). H. erectus-derived crude extract (HE) was tested in vitro for its antiproliferative activity against three human cancer cell lines, Hep-G2 (human liver cancer cell line), MCF-7 (breast cancer cell line), and Caco-2 (colon cancer cell line), before and after encapsulation within niosomes. Hyrtios erectus extract showed moderate in vitro antiproliferative activities towards the studied cell lines with IC50 values 18.5 ± 0.08, 15.2 ± 0.11, and 13.4 ± 0.12, respectively. The formulated extract-containing niosomes (size 142.3 ± 10.3 nm, PDI 0.279, and zeta potential 22.8 ± 1.6) increased the in vitro antiproliferative activity of the entrapped extract significantly (IC50 8.5 ± 0.04, 4.1 ± 0.07, and 3.4 ± 0.05, respectively). A subsequent computational chemical study was performed to build a sponge–metabolite–targets–cancer diseases network, by focusing on targets that possess anticancer activity toward the three cancer types: breast, colon, and liver. Pubchem, BindingDB, and DisGenet databases were used to build the network. Shinygo and KEGG databases in addition to FunRich software were used for gene ontology and functional analysis. The computational analysis linked the metabolites to 200 genes among which 147 genes related to cancer and only 64 genes are intersected in the three cancer types. The study proved that the co-occurrence of compounds 1, 2, 3, 7, 8, and 10 are the most probable compounds possessing cytotoxic activity due to large number of connections to the intersected cytotoxic genes with edges range from 9-14. The targets possess the anticancer effect through Pathways in cancer, Endocrine resistance and Proteoglycans in cancer as mentioned by KEGG and ShinyGo 7.1 databases. This study introduces niosomes as a promising strategy to promote the cytotoxic potential of H. erectus extract.
Molecular Network Guided Cataloging of the Secondary Metabolome of Selected Egyptian Red Sea Soft Corals
Authors: Hegazi Nesrine M. , Mohamed Tarik A. , Saad Hamada H. , Al-Hammady Montaser A. , Hussien Taha A. , Hegazy Mohamed-Elamir F. , Gross Harald
Published: October 2022

Soft corals are recognized as an abundant source of diverse secondary metabolites with unique chemical features and physiologic capabilities. However, the discovery of these metabolites is usually hindered by the traditional protocol which requires a large quantity of living tissue for isolation and spectroscopic investigations. In order to overcome this problem, untargeted metabolomics protocols have been developed. The latter have been applied here to study the chemodiversity of common Egyptian soft coral species, using only minute amounts of coral biomass. Spectral similarity networks, based on high-resolution tandem mass spectrometry data, were employed to explore and highlight the metabolic biodiversity of nine Egyptian soft coral species. Species-specific metabolites were highlighted for future prioritization of soft coral species for MS-guided chemical investigation. Overall, 79 metabolites were tentatively assigned, encompassing diterpenes, sesquiterpenes, and sterols. Simultaneously, the methodology assisted in shedding light on newly-overlooked chemical diversity with potential undescribed scaffolds. For instance, glycosylated fatty acids, nitrogenated aromatic compounds, and polyketides were proposed in Sinularia leptoclados, while alkaloidal terpenes and N-acyl amino acids were proposed in both Sarcophyton roseum and Sarcophyton acutum.
Total Synthesis and Biological Evaluation of Modified Ilamycin Derivatives
Authors: Greve Jennifer , Mogk Axel , Kazmaier Uli
Published: October 2022

Ilamycins/rufomycins are marine cycloheptapeptides containing unusual amino acids. Produced by Streptomyces sp., these compounds show potent activity against a range of mycobacteria, including multidrug-resistant strains of Mycobacterium tuberculosis. The cyclic peptides target the AAA+ protein ClpC1 that, together with the peptidases ClpP1/ClpP2, forms an essential ATP-driven protease. Derivatives of the ilamycins with a simplified tryptophane unit are synthesized in a straightforward manner. The ilamycin derivative 26 with a cyclic hemiaminal structure is active in the nM-range against several mycobacterial strains and shows no significant cytotoxicity. In contrast, derivative 27, with a glutamic acid at this position, is significantly less active, with MICs in the mid µM-range. Detailed investigations of the mode of action of 26 indicate that 26 deregulates ClpC1 activity and strongly enhances ClpC1-WT ATPase activity. The consequences of 26 on ClpC1 proteolytic activities were substrate-specific, suggesting dual effects of 26 on ClpC1-WT function. The positive effect relates to ClpC1-WT ATPase activation, and the negative to competition with substrates for binding to the ClpC1 NTD.
Effects of COVID-19 in Endocrine Patients: A Cross-Sectional Study
Authors: Morini Elisabetta , Maresca Giuseppa , Bonanno Lilla , Corallo Francesco , Lo Buono Viviana , De Cola Maria Cristina
Published: October 2022

Introduction: Home confinement due to COVID-19 lockdown led to changes in daily routines, including social interactions, as well as restrictions on the possibility of playing sports and eating habits. These changes could have a greater impact on patients suffering from chronic diseases, such as endocrine patients, especially in emotional and behavioral dimensions. Materials and Methods: This study aimed to assess the effects of COVID-19-induced quarantine on daily habits in a group of patients with endocrine disorders, focusing on food consumption, eating habits and sleep during the confinement. Eighty-five endocrine patients were enrolled. A structured interview was administered to investigate socio-demographic information, general medical conditions, and habits adopted during quarantine. All patients underwent the Spielberger State Anxiety Inventory (STAI-Y1) to assess state anxiety. Result: Results showed that subjects mainly had a sedentary lifestyle. We found a significant increase in the number of cigarettes in smokers and in meals consumed during confinement, as well as a high rate of sleep disturbance, especially insomnia. Notably, physical well-being resulted to be a predictive factor (OR = 0.38; 95%CI = [0.95,0.66]), whereas anxiety was a risk factor for sleep disorder (OR = 1.22; 95%CI = [1.10,1.40]), as was working in public and private offices and being a student. Conclusions: Changes in daily habits were likely due to the alterations in routine, resulting in greater boredom and inactivity during the day. In addition, future research should focus on the importance of patient adherence to therapy.
The Changes in Trends of Lower Gastrointestinal Endoscopy Conducted in Children and Adolescents after the COVID-19 Outbreak in Korea
Authors: Lee Sang Woo , Kang Ben , Choi Sujin , Choe Byung-Ho , Kim Yu Bin , Lee Kyung Jae , Kim Hyun Jin , Jang Hyo-Jeong , Choi So Yoon , Yi Dae Yong , Choi You Jin , Kim Ju Young , Lee Eun Hye , Lee Yoo Min
Published: October 2022

Background and Objectives: The coronavirus disease 2019 (COVID-19) pandemic has affected medical practice in diverse ways. We aimed to investigate the change in trends of lower gastrointestinal (LGI) endoscopy conducted in children and adolescents after the COVID-19 outbreak in Korea. Material and Methods: This was a multicenter, retrospective study conducted in Korea. We included children and adolescents aged <19 years who had undergone their first LGI endoscopy between 2016 and 2020. We compared clinicodemographic and endoscopic factors between groups divided according to the pre- and postCOVID-19 era in Korea. Results: We included 1307 patients in this study. Colonoscopies, instead of sigmoidoscopies, were conducted in most patients in the postCOVID-19 era compared to those in the preCOVID-19 era (86.9% vs. 78.5%, p = 0.007). The diagnosis of inflammatory bowel disease (IBD) was also significantly higher in the postCOVID-19 era compared to the preCOVID-19 era (47.2% vs. 28.5%, p < 0.001). According to multivariate logistic regression analysis, age at LGI endoscopy, LGI bleeding indication, and IBD diagnosis were independently associated with the use of a colonoscopy over a sigmoidoscopy (odds ratio (OR) 1.19, 95% confidence interval (CI) 1.12–1.27, p < 0.001; OR 0.56, 95% CI 0.37–0.83, p = 0.005; OR 1.80, 95% CI 1.20–2.77, p = 0.006, respectively). Conclusions: The COVID-19 pandemic has changed LGI endoscopy practice trends of pediatric gastroenterologists in Korea, who tended to perform lesser LGI endoscopies compared to previous years while conducting significantly more colonoscopies than sigmoidoscopies in the postCOVID-19 era. Furthermore, these colonoscopies were significantly associated with the diagnosis of IBD, as well as a significant increase in IBD diagnosis in the postCOVID-19 era.
Investigating the Influence of Anaesthesiology for Cancer Resection Surgery on Oncologic Outcomes: The Role of Experimental In Vivo Models
Authors: Howle Ryan , Moorthy Aneurin , Buggy Donal J.
Published: October 2022

The incidence and societal burden of cancer is increasing globally. Surgery is indicated in the majority of solid tumours, and recent research in the emerging field of onco-anaesthesiology suggests that anaesthetic-analgesic interventions in the perioperative period could potentially influence long-term oncologic outcomes. While prospective, randomised controlled clinical trials are the only research method that can conclusively prove a causal relationship between anaesthetic technique and cancer recurrence, live animal (in vivo) experimental models may more realistically test the biological plausibility of these hypotheses and the mechanisms underpinning them, than limited in vitro modelling. This review outlines the advantages and limitations of available animal models of cancer and how they might be used in perioperative cancer metastasis modelling, including spontaneous or induced tumours, allograft, xenograft, and transgenic tumour models.
Ascites as First Atypical and Only Clinical Manifestation of De Novo Follicular Lymphoma
Authors: Zdravkovic Natasa D. , Grbovic Vesna M. , Vojinovic Radisa H. , Stolic Radojica V. , Zivic Jelena Z. , Maksic Mladen M. , Zivic Ziva P. , Andjelkovic Nebojsa V. , Zivic Milos Z. , Todorovic Zeljko D.
Published: October 2022

Follicular lymphoma is the most common indolent non-Hodgkin’s lymphoma and is usually initially detected in lymph nodes. Primary extranodal NHL is most commonly primarily localized in the gastrointestinal tract. We present one unusual case of ileum FL with ascites as the first clinical sign. The 73-year-old female patient was presented to the emergency department for evaluation of mild abdominal pain and abdominal swelling that had been going on for three days followed by bloating and occasional pain in the spine. The abdominal contrast-enhanced CT revealed the contrast stagnation in the distal part of the ileum. The ileum wall about 11 cm in length was thickened up to 2.9 cm and the tumor mass infiltrated all layers of ileum mesenteric lymphadenopathy up to 2 cm in diameter and significant ascites. On the upper ileum wall, the vegetative mass was described 3 cm in diameter. The patient had an emergent laparotomy with the ileocolic resection and latero-lateral ileocolic anastomosis. The microscopy finding of terminal ileum and the regional lymph nodes showed domination of cleaved cells with irregular nuclei which correspond to centrocytes. There were 0–15 large non-cleaved cells corresponding to centroblast in the microscopy high-power field. The final diagnosis was follicular lymphoma, the clinical stage 2E and histological grade by Berard and Mann criteria 1–2.
Gastrointestinal Involvement in Extra-Digestive Disease: Which Is the Role of Fecal Calprotectin?
Authors: Saviano Angela , Candelli Marcello , Zanza Christian , Piccioni Andrea , Migneco Alessio , Ojetti Veronica
Published: October 2022

Fecal calprotectin (FC) is a very sensitive marker of inflammation of the gastrointestinal tract. Its clinical utility can be appreciated in both intestinal and extraintestinal diseases. Recent evidence suggests a link between intestinal inflammation and dermatological, rheumatic and neurological diseases. This review focuses on the role of FC in non-gastrointestinal disease, such as rheumatic, dermatologic, neurologic and last but not least SARS-CoV-2 infection.
Hybrid Management of an Aortobronchial Fistula after Patch Aortoplasty for Aortic Coarctation in a Patient with SARS-CoV-2 Pneumonia: Case Report and Review of the Literature
Authors: Tinica Grigore , Tarus Andrei , Bacusca Alberto , Chistol Raluca Ozana , Rusu Alexandra Cristina , Todosia Mihaela Tomaziu , Furnica Cristina
Published: October 2022

Aortobronchial fistula is a rare cause of repeated hemoptysis and a potentially fatal condition if left untreated. We present the case of a 40-year-old man with repeated hemoptysis, excessive cough, and epistaxis ongoing for several days after SARS-CoV-2 pneumonia diagnosis. The patient had a history of patch aortoplasty for aortic coarctation and aortic valve replacement with a mechanical valve for aortic insufficiency due to bicuspid aortic valve at the age of 24. Computed tomography scan performed at presentation revealed a severely dilated ascending aorta, a thoracic aorta pseudoaneurysm at the site of the former coarctation, an aortobronchial fistula suggested by the thickened left lower lobe apical segmental bronchus in contact with the pseudoaneurysm and signs of alveolar hemorrhage in the respective segment. The patient was treated with thoracic endovascular aneurysm repair (TEVAR) after prior hemi-aortic arch debranching and transposition of the left common carotid artery and subclavian artery through a closed-chest surgical approach. Our case report together with a systematic review of the literature highlight the importance of both considering an aortobronchial fistula in the differential diagnosis of hemoptysis in patients with prior history of thoracic aorta surgical intervention, regardless of associated pathology, and of taking into account endovascular and hybrid techniques as an alternative to open surgical repair, which carries a high risk of morbidity and mortality.
How Genetics and Genomics Advances Are Rewriting Pediatric Cancer Research and Clinical Care
Authors: Cipri Selene , Abenavoli Ludovico , Boccuto Luigi , Del Baldo Giada , Mastronuzzi Angela
Published: October 2022

In the last two decades, thanks to the data that have been obtained from the Human Genome Project and the development of next-generation sequencing (NGS) technologies, research in oncology has produced extremely important results in understanding the genomic landscape of pediatric cancers, which are the main cause of death during childhood. NGS has provided significant advances in medicine by detecting germline and somatic driver variants that determine the development and progression of many types of cancers, allowing a distinction between hereditary and non-hereditary cancers, characterizing resistance mechanisms that are also related to alterations of the epigenetic apparatus, and quantifying the mutational burden of tumor cells. A combined approach of next-generation technologies allows us to investigate the numerous molecular features of the cancer cell and the effects of the environment on it, discovering and following the path of personalized therapy to defeat an “ancient” disease that has had victories and defeats. In this paper, we provide an overview of the results that have been obtained in the last decade from genomic studies that were carried out on pediatric cancer and their contribution to the more accurate and faster diagnosis in the stratification of patients and the development of new precision therapies.
The Association between Admission Procalcitonin Level and The Severity of COVID-19 Pneumonia: A Retrospective Cohort Study
Authors: Aon Mohamed , Alsaeedi Abdullah , Alzafiri Azeez , Ibrahim Mohamed M. , Al-Shammari Abdelrahman , Al-Shammari Omar , Tawakul Mahmoud , Taha Sherif , Alherz Naser , Alshammari Jarrah , Albazee Ebraheem , Alharbi Teflah , Alshammari Duaa , Alenezi Zaid , Alenezi Monerah , Aldouseri Salem , Eyadah Meshari , Aldhafeeri Mariam , Aoun Ahmed H.
Published: October 2022

Background and Objectives: An elevated procalcitonin level has classically been linked to bacterial infections. Data on the association between elevated procalcitonin and the outcome of coronavirus disease 2019 (COVID-19) are conflicting. Some linked it to associated bacterial co-infections, while others correlated the elevation with disease severity without coexisting bacterial infections. We aimed to investigate the association between high procalcitonin and the severity of COVID-19. Materials and Methods: Hospitalized patients with confirmed COVID-19 pneumonia were divided into two groups: the normal-procalcitonin group and the high-procalcitonin group (>0.05 ng/mL). Patients with concomitant bacterial infections on admission were excluded. The primary outcomes were the need for intensive care unit (ICU) admission, progression to invasive mechanical ventilation (IMV), and in-hospital 28-day mortality. Results: We included 260 patients in the normal procalcitonin group and 397 patients in the high procalcitonin group. The mean age was 55 years and 49% were females. A higher number of patients in the elevated procalcitonin group required ICU admission (32.7% vs. 16.2%, p < 0.001) and IMV (27.2% vs. 13.5%, p < 0.001). In-hospital mortality was significantly higher in the elevated procalcitonin group (18.9% vs. 8.5%, p < 0.001). After adjusting for other covariates, procalcitonin > 0.05 ng/mL was an independent predictor of progression to IMV (OR, 1.71; 95% CI, 1.08–2.71; p = 0.022), ICU admission (OR, 1.73; 95% CI, 1.13–2.66; p = 0.011), and in-hospital mortality (OR, 1.99; 95% CI, 1.14–3.47; p = 0.015). An elevated procalcitonin level was the strongest predictor of in-hospital mortality. Conclusions: Measurement of procalcitonin can have a prognostic role among COVID-19 patients. The admission procalcitonin level can identify patients at risk of ICU admission, progression to IMV, and in-hospital mortality.