bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Geoinformation Systems for Assessment of Effective Integration of Renewable Energy Technologies in the Energy Sector of Ukraine
Authors: Ostapenko Olga , Olczak Piotr , Koval Viktor , Hren Larysa , Matuszewska Dominika , Postupna Olena
Published: January 2022

The scientific novelty of the results presented in this article is to substantiate and expand the possibilities of using global and local geographic information systems (GIS) to assess the potential of renewable energy sources in Ukraine. GIS analysis focused on key resource parameters can help identify territories for development of renewable energy sources and assess of their possible technical potential, as well as the possibility of effective integration of technologies for the use of renewable energy sources in the energy sector of Ukraine. In this paper the possibilities for using geographic information systems to assess the potential of renewable energy sources in Ukraine are analyzed. The possibility of using the Global Atlas of the International Renewable Energy Agency (IRENA) to support planning of technologies for the use of energy from biomass is analyzed. The data can point to large-scale programs and applications in relation to key parameters (quality resources, transmission distance, population density, terrain and site protection), helping identify additional areas for development of renewable energy sources and give an approximate assessment of technical potential. It is determined that the software products of IRENA are able to support national and regional planning of renewable energy technologies, help establish the viability of future renewable energy facilities and help project developers identify and analyze promising facilities for the implementation of technologies using renewable energy. The application of geographic information systems of Ukrainian web resources (“UA MAP”) for assessing the potential of renewable energy sources and energy efficiency in Ukraine is been analyzed. The scientific novelty of the results lies in applying global and local GIS for comprehensive assessment of the potential and effectiveness of the use of regional non-traditional and renewable energy resources on the territory of Ukraine. This makes it possible to assess the possibilities of generating additional electric and thermal power for the needs of the regions of Ukraine using non-traditional and renewable energy sources. A comprehensive methodology for the use of GIS is proposed for assessing the potential of non-traditional and renewable energy sources at the regional level in Ukraine, taking into account energy, environmental and socio-economic factors affecting the placement of non-traditional and renewable energy facilities.
Dosimetric Characterization of Small Radiotherapy Electron Beams Collimated by Circular Applicators with the New Microsilicon Detector
Authors: Russo Serenella , Bettarini Silvia , Grilli Leonulli Barbara , Esposito Marco , Alpi Paolo , Ghirelli Alessandro , Barca Raffaella , Fondelli Simona , Paoletti Lisa , Pini Silvia , Scoccianti Silvia
Published: January 2022

High-energy small electron beams, generated by linear accelerators, are used for radiotherapy of localized superficial tumours. The aim of the present study is to assess the dosimetric performance under small radiation therapy electron beams of the novel PTW microSilicon detector compared to other available dosimeters. Relative dose measurements of circular fields with 20, 30, 40, and 50 mm aperture diameters were performed for electron beams generated by an Elekta Synergy linac, with energy between 4 and 12 MeV. Percentage depth dose, transverse profiles, and output factors, normalized to the 10 × 10 cm2 reference field, were measured. All dosimetric data were collected in a PTW MP3 motorized water phantom, at SSD of 100 cm, by using the novel PTW microSilicon detector. The PTW diode E and the PTW microDiamond were also used in all beam apertures for benchmarking. Data for the biggest field size were also measured by the PTW Advanced Markus ionization chamber. Measurements performed by the microSilicon are in good agreement with the reference values for all the tubular applicators and beam energies within the stated uncertainties. This confirms the reliability of the microSilicon detector for relative dosimetry of small radiation therapy electron beams collimated by circular applicators.
Multi-UAV Conflict Resolution with Graph Convolutional Reinforcement Learning
Authors: Isufaj Ralvi , Omeri Marsel , Piera Miquel Angel
Published: January 2022

Safety is the primary concern when it comes to air traffic. In-flight safety between Unmanned Aircraft Vehicles (UAVs) is ensured through pairwise separation minima, utilizing conflict detection and resolution methods. Existing methods mainly deal with pairwise conflicts, however, due to an expected increase in traffic density, encounters with more than two UAVs are likely to happen. In this paper, we model multi-UAV conflict resolution as a multiagent reinforcement learning problem. We implement an algorithm based on graph neural networks where cooperative agents can communicate to jointly generate resolution maneuvers. The model is evaluated in scenarios with 3 and 4 present agents. Results show that agents are able to successfully solve the multi-UAV conflicts through a cooperative strategy.
A Comparative Study of the Application of Different Commercial Software for Topology Optimization
Authors: Tyflopoulos Evangelos , Steinert Martin
Published: January 2022

Topology optimization (TO) has been a popular design method among CAD designers in the last decades. This method optimizes the given design domain by minimizing/maximizing one or more objective functions, such as the structure’s stiffness, and at the same time, respecting the given constraints like the volume or the weight reduction. For this reason, the companies providing the commercial CAD/FEM platforms have taken this design trend into account and, thus, have included TO in their products over the last years. However, it is not clear which features, algorithms, or, in other words, possibilities the CAD designers do have using these software platforms. A comparative study among the most applied topology optimization software was conducted for this research paper. First, the authors developed an online database of the identified TO software in the form of a table. Interested CAD designers can access and edit its content, contributing in this way to the creation of an updated library of the available TO software. In addition, a deeper comparison among three commercial software platforms—SolidWorks, ANSYS Mechanical, and ABAQUS—was implemented using three common case studies—(1) a bell crank lever, (2) a pillow bracket, and (3) a small bridge. These models were designed, optimized, and validated numerically, as well as compared for their strength. Finally, the above software was evaluated with respect to optimization time, optimized designs, and TO possibilities and features.
Hybrid Dual-Hop RF/FSO Terrestrial-Deep Space Communication System under Solar Scintillation during Superior Solar Conjunction
Authors: Jin Meng , Liu Wenyi , Hao Yuan , Wu Ruihuan , Wei Zhongchao , Deng Dongmei , Liu Hongzhan
Published: January 2022

Free-space optical communication (FSO) technology has wide prospects in deep space exploration, but it will encounter coronal turbulence during superior solar conjunction, and solar scintillation will seriously affect the communication quality. In this paper, we propose a terrestrial–deep space hybrid radio frequency (RF)/FSO system with the hybrid L-pulse position modulation-binary phase shift keying-subcarrier intensity modulation (L-PPM–BPSK–SIM) scheme, where the RF channel of the satellite-terrestrial relay follows the Rayleigh distribution, and the FSO channel of the relay satellite to the deep space probe adopts Gamma–Gamma distribution. Considering the pointing error, the expression of the bit error rate (BER), the outage probability, and the average channel capacity of the hybrid system are derived. In addition, we evaluated the influence of coronal turbulence parameters on the system through amplitude fluctuations. The simulation results demonstrate that the hybrid RF/FSO system improves the BER performance by 10 to 30 times in a deep space environment, and the use of a hybrid modulation can further reduce the BER. The non-Kolmogorov spectral index, outer scale, solar wind density fluctuation factor, and optical wavelength comprehensively affect the BER through amplitude fluctuations. Our research results have potential application value for evaluating the link performance of future deep space communications.
Design, Manufacture and Wind Tunnel Test of a Modular FishBAC Wing with Novel 3D Printed Skins
Authors: Rivero Andrés E. , Fournier Stephane , Heeb Rafael M. , Woods Benjamin K. S.
Published: January 2022

This paper introduces a new modular Fish Bone Active Camber morphing wing with novel 3D printed skin panels. These skin panels are printed using two different Thermoplastic Polyurethane (TPU) formulations: a soft, high strain formulation for the deformable membrane of the skin, reinforced with a stiffer formulation for the stringers and mounting tabs. Additionally, this is the first FishBAC device designed to be modular in its installation and actuation. Therefore, all components can be removed and replaced for maintenance purposes without having to remove or disassemble other parts. A 1 m span, 0.27 m chord morphing wing with a 25% chord FishBAC was built and tested mechanically and in a low-speed wind tunnel. Results show that the new design is capable of achieving the same large changes in airfoil lift coefficient (approximate ΔCL≈0.55) with a low drag penalty seen in previous FishBAC work, but with a much simpler, practical and modular design. Additionally, the device shows a change in the pitching moment coefficient of ΔCM≈0.1, which shows the potential that the FishBAC has as a control surface.
A Real Time Algorithm for Versatile Mode Parking System and Its Implementation on FPGA Board
Authors: Naji Baligh , Abdelmoula Chokri , Masmoudi Mohamed
Published: January 2022

This paper presents the design and development of a technique for an Autonomous and Versatile mode Parking System (AVPS) that combines a various number of parking modes. The proposed approach is different from that of many developed parking systems. Previous research has focused on choosing only a parking lot starting from two parking modes (which are parallel and perpendicular). This research aims at developing a parking system that automatically chooses a parking lot starting from four parking modes. The automatic AVPS was proposed for the car-parking control problem, and could be potentially exploited for future vehicle generation. A specific mode can be easily computed using the proposed strategy. A variety of candidate modes could be generated using one developed real time VHDL (VHSIC Hardware Description Language) algorithm providing optimal solutions with performance measures. Based on simulation and experimental results, the AVPS is able to find and recognize in advance which parking mode to select. This combination describes full implementation on a mobile robot, such as a car, based on a specific FPGA (Field-Programmable Gate Array) card. To prove the effectiveness of the proposed innovation, an evaluation process comparing the proposed technique with existing techniques was conducted and outlined.
Physiological Effects of Bioactive Compounds Derived from Whole Grains on Cardiovascular and Metabolic Diseases
Authors: Chung Sangwon , Hwang Jin-Taek , Park Soo-Hyun
Published: January 2022

Cardiovascular diseases are a global health burden with an increasing prevalence. In addition, various metabolic diseases, such as obesity, diabetes, and hypertension are associated with a higher risk of cardiovascular diseases. Dietary strategies based on healthy foods have been suggested for the prevention or improvement of cardiovascular and metabolic diseases. Grains are the most widely consumed food worldwide, and the preventive effects of whole grains (e.g., oats, barley, and buckwheat) on metabolic diseases have been reported. The germ and bran of grains are rich in compounds, including phytochemicals, vitamins, minerals, and dietary fiber, and these compounds are effective in preventing and improving cardiovascular and metabolic diseases. Thus, this review describes the characteristics and functions of bioactive ingredients in whole grains, focusing on mechanisms by which polyphenols, antioxidants, and dietary fiber contribute to cardiovascular and metabolic diseases, based on preclinical and clinical studies. There is clear evidence for the broad preventive and therapeutic effects of whole grains, supporting the value of early dietary intervention.
Experimental and Numerical Study for a Novel Arrangement of a SuperCapacitors Stack to Improve Heat Transfer
Authors: Victor Voicu Ionut , Bode Florin , Abboud Wassim , Louahlia Hasna , Gualous Hamid , Sandu Mihnea , Nastase Ilinca
Published: January 2022

Supercapacitors (SCs) are electrical energy storage devices which have the peculiarity of storing more electrical energy than capacitors and supply it at higher power outputs than batteries. This, together with the fact that the SCs have high cyclability and long-term stability, make them very attractive devices for electrical energy storage. Thermal transfer around a novel arrangement of a module of five rows of SCs is approached in this paper. A mixed aligned/staggered configuration is studied, aiming to explore a new possibility that can improve heat transfer more than other configurations studied before in the literature. The maximum SC current rate current is 84 A and the maximum temperature is 65 °C. The module undergoes charge and discharge cycles. The current tests are performed up to 50 A for natural convection and up to 70 A in forced convection. For the natural convection case, the SC located in the center of module is the most critical from the temperature point of view and the temperature evolution shows the necessity of a cooling system. The relative temperature reaches 27 °C for 50 A and the permanent regime cannot be reached with a current greater than 50 A. Thereafter, the impact of position and current on the temperature of SCs in forced convection is examined. The airflow mean air velocity is 0.69 m/s. The temperature of the SCs located on the third and fourth row are very close. However, the last row is the least cooled. This low temperature rise can be explained by the change from an aligned to a staggered arrangement between these rows. Compared to the natural convection case, a significant decrease is observed for the relative temperatures. The difference between the highest and lowest temperature augmentation also decrease but remain high. The temperature difference becomes greater than 5 °C if continuous current exceeds 39 A. CFD numerical simulation is performed for steady state at maximum experimental current rate in order to better understand the thermal and flow behavior. Numerical and experimental results are in good agreement, with a temperature deviation of less than 10%.
Effect of Permittivity on the Electric-Field-Driven Rotation Dynamics in a Liquid Film
Authors: Shirsavar Reza , Mollaei Saeid , Moeini Rizi Mansoure , Moradi Ali-Reza , Amjadi Ahmad , Habibi Mehdi , Najafi Ali
Published: January 2022

Applying a constant electric field on a suspended film of liquid that carries an electric current, either by the transport of ions or surface charges, induces a rotation in the film. This system is known as “liquid film motor”. So far, the effect of permittivity of the liquid on its rotation has been ignored. We showed that the permittivity of the liquid can significantly affect the dynamics of rotation. Using an experimental approach, we studied the liquid film rotation for a broad range of pure liquids with diverse permittivities and surface tensions. We observed two different regimes of rotation depending on the permittivity of the liquids. We also found that there is no correlation between the surface tension of the liquid and the angular velocity of the rotation. We considered a theoretical framework and suggested scenarios to explain our experimental observations. These results help in better understanding the physics of liquid film motors and suggest opportunities for new flow manipulation techniques at small scales.
From Time-Collocated to Leapfrog Fundamental Schemes for ADI and CDI FDTD Methods
Authors: Tan Eng Leong
Published: January 2022

The leapfrog schemes have been developed for unconditionally stable alternating-direction implicit (ADI) finite-difference time-domain (FDTD) method, and recently the complying-divergence implicit (CDI) FDTD method. In this paper, the formulations from time-collocated to leapfrog fundamental schemes are presented for ADI and CDI FDTD methods. For the ADI FDTD method, the time-collocated fundamental schemes are implemented using implicit E-E and E-H update procedures, which comprise simple and concise right-hand sides (RHS) in their update equations. From the fundamental implicit E-H scheme, the leapfrog ADI FDTD method is formulated in conventional form, whose RHS are simplified into the leapfrog fundamental scheme with reduced operations and improved efficiency. For the CDI FDTD method, the time-collocated fundamental scheme is presented based on locally one-dimensional (LOD) FDTD method with complying divergence. The formulations from time-collocated to leapfrog schemes are provided, which result in the leapfrog fundamental scheme for CDI FDTD method. Based on their fundamental forms, further insights are given into the relations of leapfrog fundamental schemes for ADI and CDI FDTD methods. The time-collocated fundamental schemes require considerably fewer operations than all conventional ADI, LOD and leapfrog ADI FDTD methods, while the leapfrog fundamental schemes for ADI and CDI FDTD methods constitute the most efficient implicit FDTD schemes to date.
Reconstruction of Differential Operators with Frozen Argument
Authors: Dobosevych Oles , Hryniv Rostyslav
Published: January 2022

We study spectral properties of a wide class of differential operators with frozen arguments by putting them into a general framework of rank-one perturbation theory. In particular, we give a complete characterization of possible eigenvalues for these operators and solve the inverse spectral problem of reconstructing the perturbation from the resulting spectrum. This approach provides a unified treatment of several recent studies and gives a clear explanation and interpretation of the obtained results.
Numerical Scheme Based on the Implicit Runge-Kutta Method and Spectral Method for Calculating Nonlinear Hyperbolic Evolution Equations
Authors: Takei Yasuhiro , Iwata Yoritaka
Published: January 2022

A numerical scheme for nonlinear hyperbolic evolution equations is made based on the implicit Runge-Kutta method and the Fourier spectral method. The detailed discretization processes are discussed in the case of one-dimensional Klein-Gordon equations. In conclusion, a numerical scheme with third-order accuracy is presented. The order of total calculation cost is O(Nlog2N). As a benchmark, the relations between numerical accuracy and discretization unit size and that between the stability of calculation and discretization unit size are demonstrated for both linear and nonlinear cases.
On Developing Generic Models for Predicting Student Outcomes in Educational Data Mining
Authors: Ramaswami Gomathy , Susnjak Teo , Mathrani Anuradha
Published: January 2022

Poor academic performance of students is a concern in the educational sector, especially if it leads to students being unable to meet minimum course requirements. However, with timely prediction of students’ performance, educators can detect at-risk students, thereby enabling early interventions for supporting these students in overcoming their learning difficulties. However, the majority of studies have taken the approach of developing individual models that target a single course while developing prediction models. These models are tailored to specific attributes of each course amongst a very diverse set of possibilities. While this approach can yield accurate models in some instances, this strategy is associated with limitations. In many cases, overfitting can take place when course data is small or when new courses are devised. Additionally, maintaining a large suite of models per course is a significant overhead. This issue can be tackled by developing a generic and course-agnostic predictive model that captures more abstract patterns and is able to operate across all courses, irrespective of their differences. This study demonstrates how a generic predictive model can be developed that identifies at-risk students across a wide variety of courses. Experiments were conducted using a range of algorithms, with the generic model producing an effective accuracy. The findings showed that the CatBoost algorithm performed the best on our dataset across the F-measure, ROC (receiver operating characteristic) curve and AUC scores; therefore, it is an excellent candidate algorithm for providing solutions on this domain given its capabilities to seamlessly handle categorical and missing data, which is frequently a feature in educational datasets.
Monocytes in Neonatal Bacterial Sepsis: Think Tank or Workhorse?
Authors: Doughty Caitlin , Oppermann Louise , Hartmann Niels-Ulrik , Dreschers Stephan , Gille Christian , Orlikowsky Thorsten
Published: January 2022

Infection and sepsis remain among the leading causes of neonatal mortality. The susceptibility of newborns to infection can be attributed to their immature immune system. Regarding immune response, monocytes represent a numerically minor population of leukocytes. However, they contribute to a variety of immunological demands, such as continuous replenishment of resident macrophages under non-infectious conditions and migration to inflamed sites where they neutralize pathogens and secrete cytokines. Further functions include the presentation of antigens and T-cell activation. Cytokines coordinate host responses to bacterial and viral infections and orchestrate ongoing physiological signaling between cells of non-immune tissues. A critical event is the skewing of the cytokine repertoire to achieve a resolution of infection. In this regard, monocytes may hold a key position as deciders in addition to their phagocytic activity, securing the extinction of pathogens to prevent broader organ damage by toxins and pro-inflammatory reactions. Neonatal monocytes undergo various regulatory and metabolic changes. Thus, they are thought to be vulnerable in anticipating pro-inflammatory conditions and cause severe progressions which increase the risk of developing sepsis. Furthermore, clinical studies have shown that exposure to inflammation puts neonates at a high risk for adverse pulmonary, immunological and other organ developments, which may result in multiorgan disease. This review discusses significant functions and impairments of neonatal monocytes that are decisive for the outcome of bacterial infections.
Nutrient Digestibility, Microbial Fermentation, and Response in Bacterial Composition to Methionine Dipeptide: An In Vitro Study
Authors: Kong Fanlin , Liu Yanfang , Wang Shuo , Zhang Yijia , Wang Wei , Yang Hongjian , Lu Na , Li Shengli
Published: January 2022

It is well known that the methionine dipeptide (MD) could enhance the dairy cows milking performance. However, there is still a knowledge gap of the effects of MD on the rumen fermentation characteristics, microbiota composition, and digestibility. This experiment was conducted to determine the effect of different nitrogen sources with a total mixed ration on in vitro nutrient digestibility, fermentation characteristics, and bacterial composition. The treatments included 5 mg urea (UR), 25.08 mg methionine (Met), 23.57 mg MD, and no additive (CON) in fermentation culture medium composed of buffer solution, filtrated Holstein dairy cow rumen fluid, and substrate (1 g total mixed ration). Nutrient digestibility was measured after 24 h and 48 h fermentation, and fermentation parameters and microbial composition were measured after 48 h fermentation. Digestibility of dry matter, crude protein, neutral detergent fiber (NDF), and acid detergent fiber (ADF) in the MD group at 48 h were significantly higher than in the CON and UR groups. The total volatile fatty acid concentration was higher in the MD group than in the other groups. In addition, 16S rRNA microbial sequencing results showed MD significantly improved the relative abundances of Succinivibrio, Anaerotruncus, and Treponema_2, whereas there was no significant difference between Met and UR groups. Spearman’s correlation analysis showed the relative abundance of Succinivibrio and Anaerotruncus were positively correlated with gas production, NDF digestibility, ADF digestibility, and acetate, propionate, butyrate, and total volatile fatty acid concentrations. Overall, our results suggested that the microbiota in the fermentation system could be affected by additional nitrogen supplementation and MD could effectively enhance the nutrient utilization in dairy cows.
KL-6 in ANCA-Associated Vasculitis Patients with and without ILD: A Machine Learning Approach
Authors: Conticini Edoardo , d’Alessandro Miriana , Bergantini Laura , Castillo Diego , Cameli Paolo , Frediani Bruno , Cantarini Luca , Bargagli Elena
Published: January 2022

Background: ANCA-associated vasculitis (AAV) are small vessel vasculitis distinguished between microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA). The former may have interstitial lung disease (ILD) associated with high morbidity and mortality. Here, Krebs von den Lungen-6 (KL-6), a marker of fibrotic ILD, was assessed for distinguishing AAV patients with ILD from those without ILD, and whether its changes over time are correlated with disease activity. Materials and Methods: Thirteen AAV patients (eight females, mean age 61 ± 14.8 years) were enrolled: six MPA and six GPA. Serum samples were assayed for KL-6 concentrations (Fujirebio Europe, Belgium). To investigate potential binary classifiers for diagnosis of AAV-ILD, we constructed a regression decision tree model. Results: Higher serum KL-6 were in AAV-ILD compared with those without ILD (972.8 ± 398.5 vs 305.4 ± 93.9, p = 0.0040). Area under the receiver operating characteristics curve showed 100% of the diagnostic performance of KL-6 for identifying the ILD involvement (accuracy 91.7%) and the best cutoff value of 368 U/mL (sensitivity 100% and specificity 87.5%). The decision tree model showed a 33% improvement in class purity using a cut-off value of 513 U/mL to distinguish AAV patients with and without ILD. Stratifying AAV patients as MPA and GPA with and without ILD considering T0 and T1 KL-6, the model obtained an improvement of 40% for classifying GPA non-ILD with a T0 serum KL-6 cut-off value of 513 U/mL and a T1 KL-6 cut-off of 301 U/mL. A direct correlation was found between serum T0 KL-6 and T0 BVAS (r = 0.578, p = 0.044). Conclusion: Our multicenter study demonstrated KL-6 as a reliable, non-invasive, and easy-to-perform marker of ILD in AAV patients and its helpfulness for disease activity assessment. Changes in serum concentrations of KL-6 over time could be useful for monitoring AAV patients. Further study of KL-6 as a marker of response to therapy during long-term follow-up would also be worthwhile.
A Time-Course Study on a Food Contact Material (FCM)-Certified Coating Based on Titanium Oxide Deposited onto Aluminum
Authors: Di Cerbo Alessandro , Mescola Andrea , Rosace Giuseppe , Trovato Valentina , Canton Roberto , Iseppi Ramona , Stocchi Roberta , Ghazanfar Shakira , Rea Stefano , Loschi Anna Rita , Sabia Carla
Published: January 2022

Aluminum is the second most widely used metal worldwide. It is present as an additive in cosmetics, pharmaceuticals, food, and food contact materials (FCM). In this study, we confirm the bactericidal effect of a special anodizing method, based on TiO2 nanoparticles (DURALTI®) deposited on aluminum disks with different roughness and subjected to two sanitizing treatments: UV and alcohol 70%. Consequently, we perform a time-course evaluation against both Gram-negative and Gram-positive bacteria to better frame the time required to achieve the best result. Approximately 106 CFU/mL of Escherichia coli ATCC 25922; Salmonella Typhimurium ATCC 1402; Yersinia enterocolitica ATCC 9610; Pseudomonas aeruginosa ATCC 27588; Staphylococcus aureus ATCC 6538; Enterococcus faecalis ATCC 29212; Bacillus cereus ATCC 14579 and Listeria monocytogenes NCTT 10888 were inoculated onto each aluminum surface and challenged with UV and alcohol 70% at 0, 15”, 30”, 1′, 5′, 15′, 30′, 1, 2, 4 and 6 h. DURALTI® coating already confirmed its ability to induce a 4-logarithmic decrease (from 106 to 102 CFU/mL) after 6 h. Once each sanitizing treatment was applied, an overall bacterial inhibition occurred in a time ranging from 15′′ to 1′. The results are innovative in terms of preventing microbial adhesion and growth in the food industry.
Biological Response of Planktic Foraminifera to Decline in Seawater pH
Authors: Dong Shuaishuai , Lei Yanli , Bi Hongsheng , Xu Kuidong , Li Tiegang , Jian Zhimin
Published: January 2022

Understanding the way in which a decline in ocean pH can affect calcareous organisms could enhance our ability to predict the impacts of the potential decline in seawater pH on marine ecosystems, and could help to reconstruct the paleoceanographic events over a geological time scale. Planktic foraminifera are among the most important biological proxies for these studies; however, the existing research on planktic foraminifera is almost exclusively based on their geochemical indices, without the inclusion of information on their biological development. Through a series of on-board experiments in the western tropical Pacific (134°33′54″ E, 12°32′47″ N), the present study showed that the symbiont-bearing calcifier Trilobatus sacculifer—a planktic foraminifer—responded rapidly to a decline in seawater pH, including losing symbionts, bleaching, etc. Several indices were established to quantify the relationships between these biological parameters and seawater pH, which could be used to reconstruct the paleoceanographic seawater pH. We further postulated that the loss of symbionts in planktic foraminifera acts as an adaptive response to the stress of low pH. Our results indicate that an ongoing decline in seawater pH may hinder the growth and calcification of planktic foraminifera by altering their biological processes. A reduction in carbonate deposition and predation could have profound effects on the carbon cycle and energy flow in the marine food web.
The Role of miRNA in Regulating the Fate of Monocytes in Health and Cancer
Authors: Alwani Anna , Andreasik Aneta , Szatanek Rafał , Siedlar Maciej , Baj-Krzyworzeka Monika
Published: January 2022

Monocytes represent a heterogeneous population of blood cells that provide a link between innate and adaptive immunity. The unique potential of monocytes as both precursors (e.g., of macrophages) and effector cells (as phagocytes or cytotoxic cells) makes them an interesting research and therapeutic target. At the site of a tumor, monocytes/macrophages constitute a major population of infiltrating leukocytes and, depending on the type of tumor, may play a dual role as either a bad or good indicator for cancer recovery. The functional activity of monocytes and macrophages derived from them is tightly regulated at the transcriptional and post-transcriptional level. This review summarizes the current understanding of the role of small regulatory miRNA in monocyte formation, maturation and function in health and cancer development. Additionally, signatures of miRNA-based monocyte subsets and the influence of exogenous miRNA generated in the tumor environment on the function of monocytes are discussed.
Lignin-Based Nonviral Gene Carriers Functionalized by Poly[2-(Dimethylamino)ethyl Methacrylate]: Effect of Grafting Degree and Cationic Chain Length on Transfection Efficiency
Authors: Liu Xiaohong , Yin Hui , Song Xia , Zhang Zhongxing , Li Jun
Published: January 2022

Lignin is a natural renewable biomass resource with great potential for applications, while its development into high value-added molecules or materials is rare. The development of biomass lignin as potential nonviral gene delivery carriers was initiated by our group through the “grafting-from” approach. Firstly, the lignin was modified into macroinitiator using 2-bromoisobutyryl bromide. Then cationic polymer chains of poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) were grown from the lignin backbone using atom transfer radical polymerization (ATRP) to yield lignin-PDMAEMA graft copolymers (LPs) with branched structure. To gain a deep understanding of the relationship between the nonviral gene transfection efficiency of such copolymers and their structural and compositional factors, herein eight lignin-based macroinitiators with different modification degrees (MDs, from 3.0 to 100%) were synthesized. Initiated by them, a series of 20 LPs were synthesized with varied structural factors such as grafting degree (GD, which is equal to MD, determining the cationic chain number per lignin macromolecule), cationic chain length (represented by number of repeating DMAEMA units per grafted arm or degree of polymerization, DP) as well as the content of N element (N%) which is due to the grafted PDMAEMA chains and proportional to molecular weight of the LPs. The in vitro gene transfection capability of these graft copolymers was evaluated by luciferase assay in HeLa, COS7 and MDA-MB-231cell lines. Generally, the copolymers LP-12 (N% = 7.28, MD = 36.7%, DP = 13.6) and LP-14 (N% = 6.05, MD = 44.4%, DP = 5.5) showed good gene transfection capabilities in the cell lines tested. Overall, the performance of LP-12 was the best among all the LPs in the three cell lines at the N/P ratios from 10 to 30, which was usually several times higher than PEI standard. However, in MDA-MB-231 at N/P ratio of 30, LP-14 showed the best gene transfection performance among all the LPs. Its gene transfection efficiency was ca. 11 times higher than PEI standard at this N/P ratio. This work demonstrated that, although the content of N element (N%) which is due to the grafted PDMAEMA chains primarily determines the gene transfection efficiency of the LPs, it is not the only factor in explaining the performance of such copolymers with the branched structure. Structural factors of these copolymers such as grafting degree and cationic chain length could have a profound effect on the copolymer performance on gene transfection efficiency. Through carefully adjusting these factors, the gene transfection efficiency of the LPs could be modulated and optimized for different cell lines, which could make this new type of biomass-based biomaterial an attractive choice for various gene delivery applications.
Longitudinal Effects of Serum Calcium and Phosphate Levels and Their Ratio on Incident Ischemic Heart Disease among Korean Adults
Authors: Jung Dong Hyuk , Park Byoungjin , Lee Yong Jae
Published: January 2022

Serum calcium and phosphate levels are controlled by a regulatory system, but their individual concentration tendencies and interactions may affect long-term vascular health. This study aimed to assess the effects of serum calcium and phosphate levels on incident ischemic heart disease (IHD) in a large-scale community-dwelling Korean cohort. We evaluated 15,259 non-diabetic individuals (median age, 45 years; range, 30–85) without previous IHD or ischemic stroke using the Korean National Health Insurance data. The study population was classified based on the calcium, phosphate, and calcium/phosphate ratios. Using Cox proportional hazards regression models, we estimated hazard ratios (HRs) with 95% confidence intervals (CIs) for IHD over 50 months after baseline enrolment. The age- and sex-adjusted incidence of IHD gradually increased with serum calcium and phosphate quartiles and decreased with calcium/phosphate ratio quartiles, with an overall crude rate of 2.1% (315/15,259). After setting the lowest calcium, phosphate, and calcium/phosphate ratio quartiles as a reference group, the HRs (95% CIs) of the highest calcium, phosphate, and calcium/phosphate ratio quartiles for IHD were 1.77 (1.15–2.72), 1.73 (1.18–2.55), and 0.58 (0.39–0.87), respectively, after adjusting for potential confounding variables. Serum calcium and phosphate levels were positively associated with IHD incidence, while the serum calcium/phosphate ratio exhibited an inverse relationship. Serum calcium and phosphate homeostasis may merit serious consideration to understand the pathogenesis of coronary atherosclerosis as a risk modifier for IHD.
Liver Stiffness, Albuminuria and Chronic Kidney Disease in Patients with NAFLD: A Systematic Review and Meta-Analysis
Authors: Ciardullo Stefano , Ballabeni Cinzia , Trevisan Roberto , Perseghin Gianluca
Published: January 2022

An association between liver stiffness, a surrogate measure of liver fibrosis, and chronic kidney disease (CKD) in patients with nonalcoholic fatty liver disease (NAFLD) has been proposed. However, most studies were small and had low statistical power. We systematically searched PubMed-MEDLINE and Scopus from inception to August 2021 for cross-sectional or cohort studies reporting the association between liver stiffness diagnosed by vibration controlled transient elastography (VCTE) and renal dysfunction. The primary outcome was CKD, defined as a composite of urinary albumin to creatinine ratio (UACR) ≥ 30 mg/g and estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2. Measures of association from individual studies were meta-analyzed using random effects models. Of the 526 titles initially scrutinized, 7 cross-sectional studies fulfilled the criteria and were included. For CKD, risk was higher in patients with liver fibrosis assessed by VCTE, compared with patients without (n = 5 studies: OR 2.49, 95% CI 1.89–3.29; test for overall effect z = 6.475, p < 0.001). When increased UACR was considered as an outcome, elevated liver stiffness was associated with a significantly increased risk as well (n = 3 studies: OR 1. 98 95% CI 1.29–3.05; test for overall effect z = 3.113, p = 0.002). Neither analysis showed significant heterogeneity (I2 = 0% and I2 = 46.5%, respectively for the two outcomes). This meta-analysis indicates that elevated liver stiffness is associated with increased odds of kidney outcomes among patients with NAFLD. Wider use of VCTE to screen for advanced fibrosis might help identify patients at risk of end-stage renal disease.
Sex Hormone-Specific Neuroanatomy of Takotsubo Syndrome: Is the Insular Cortex a Moderator?
Authors: Nagai Michiaki , Förster Carola Yvette , Dote Keigo
Published: January 2022

Takotsubo syndrome (TTS), a transient form of dysfunction in the heart’s left ventricle, occurs predominantly in postmenopausal women who have emotional stress. Earlier studies support the concept that the human circulatory system is modulated by a cortical network (consisting of the anterior cingulate gyrus, amygdala, and insular cortex (Ic)) that plays a pivotal role in the central autonomic nervous system in relation to emotional stressors. The Ic plays a crucial role in the sympathovagal balance, and decreased levels of female sex hormones have been speculated to change functional cerebral asymmetry, with a possible link to autonomic instability. In this review, we focus on the Ic as an important moderator of the human brain–heart axis in association with sex hormones. We also summarize the current knowledge regarding the sex-specific neuroanatomy in TTS.
Impact of Physical Activity and Exercise on the Epigenome in Skeletal Muscle and Effects on Systemic Metabolism
Authors: Plaza-Diaz Julio , Izquierdo David , Torres-Martos Álvaro , Baig Aiman Tariq , Aguilera Concepción M. , Ruiz-Ojeda Francisco Javier
Published: January 2022

Exercise and physical activity induces physiological responses in organisms, and adaptations in skeletal muscle, which is beneficial for maintaining health and preventing and/or treating most chronic diseases. These adaptations are mainly instigated by transcriptional responses that ensue in reaction to each individual exercise, either resistance or endurance. Consequently, changes in key metabolic, regulatory, and myogenic genes in skeletal muscle occur as both an early and late response to exercise, and these epigenetic modifications, which are influenced by environmental and genetic factors, trigger those alterations in the transcriptional responses. DNA methylation and histone modifications are the most significant epigenetic changes described in gene transcription, linked to the skeletal muscle transcriptional response to exercise, and mediating the exercise adaptations. Nevertheless, other alterations in the epigenetics markers, such as epitranscriptomics, modifications mediated by miRNAs, and lactylation as a novel epigenetic modification, are emerging as key events for gene transcription. Here, we provide an overview and update of the impact of exercise on epigenetic modifications, including the well-described DNA methylations and histone modifications, and the emerging modifications in the skeletal muscle. In addition, we describe the effects of exercise on epigenetic markers in other metabolic tissues; also, we provide information about how systemic metabolism or its metabolites influence epigenetic modifications in the skeletal muscle.
Interplay of Oxidative Stress and Necrosis-like Cell Death in Cardiac Ischemia/Reperfusion Injury: A Focus on Necroptosis
Authors: Adameova Adriana , Horvath Csaba , Abdul-Ghani Safa , Varga Zoltan V. , Suleiman M. Saadeh , Dhalla Naranjan S.
Published: January 2022

Extensive research work has been carried out to define the exact significance and contribution of regulated necrosis-like cell death program, such as necroptosis to cardiac ischemic injury. This cell damaging process plays a critical role in the pathomechanisms of myocardial infarction (MI) and post-infarction heart failure (HF). Accordingly, it has been documented that the modulation of key molecules of the canonical signaling pathway of necroptosis, involving receptor-interacting protein kinases (RIP1 and RIP3) as well as mixed lineage kinase domain-like pseudokinase (MLKL), elicit cardioprotective effects. This is evidenced by the reduction of the MI-induced infarct size, alleviation of myocardial dysfunction, and adverse cardiac remodeling. In addition to this molecular signaling of necroptosis, the non-canonical pathway, involving Ca2+/calmodulin-dependent protein kinase II (CaMKII)-mediated regulation of mitochondrial permeability transition pore (mPTP) opening, and phosphoglycerate mutase 5 (PGAM5)–dynamin-related protein 1 (Drp-1)-induced mitochondrial fission, has recently been linked to ischemic heart injury. Since MI and HF are characterized by an imbalance between reactive oxygen species production and degradation as well as the occurrence of necroptosis in the heart, it is likely that oxidative stress (OS) may be involved in the mechanisms of this cell death program for inducing cardiac damage. In this review, therefore, several observations from different studies are presented to support this paradigm linking cardiac OS, the canonical and non-canonical pathways of necroptosis, and ischemia-induced injury. It is concluded that a multiple therapeutic approach targeting some specific changes in OS and necroptosis may be beneficial in improving the treatment of ischemic heart disease.
HDL Is Not Dead Yet
Authors: Lorkowski Shuhui Wang , Smith Jonathan D.
Published: January 2022

High-density lipoprotein cholesterol (HDL-C) levels are inversely correlated with coronary heart disease (CHD) in multiple epidemiological studies, but whether HDL is causal or merely associated with CHD is unclear. Recent trials for HDL-raising drugs were either not effective in reducing CHD events or, if beneficial in reducing CHD events, were not conclusive as the findings could be attributed to the drugs’ LDL-reducing activity. Furthermore, the first large Mendelian randomization study did not causally relate HDL-C levels to decreased CHD. Thus, the hypothesis that HDL is protective against CHD has been rightfully challenged. However, subsequent Mendelian randomization studies found HDL characteristics that are causally related to decreased CHD. Many aspects of HDL structure and function, especially in reverse cholesterol transport, may be better indicators of HDL’s protective activity than simply measuring HDL-C. Cholesterol efflux capacity is associated with lower levels of prevalent and incident CHD, even after adjustment for HDL-C and apolipoprotein A-1 levels. Also, subjects with very high levels of HDL-C, including those with rare mutations that disrupt hepatic HDL uptake and reverse cholesterol transport, may be at higher risk for CHD than those with moderate levels. We describe here several cell-based and cell-free in vitro assays of HDL structure and function that may be used in clinical studies to determine which of HDL’s functions are best associated with protection against CHD. We conclude that the HDL hypothesis may need revision based on studies of HDL structure and function, but that the HDL hypothesis is not dead yet.
GABA Administration Ameliorates Sjogren’s Syndrome in Two Different Mouse Models
Authors: Song Min , Tian Jide , Middleton Blake , Nguyen Cuong Q. , Kaufman Daniel L.
Published: January 2022

Sjögren’s syndrome (SS) is a chronic autoimmune disease characterized by lymphocytic infiltrates in the salivary and lachrymal glands resulting in oral and ocular dryness. There are no clinically approved therapies to slow the progression of SS. Immune cells possess receptors for the neurotransmitter GABA (GABA-Rs) and their activation has immunoregulatory actions. We tested whether GABA administration has potential for amelioration of SS in NOD.B10-H2b and C57BL/6.NOD-Aec1Aec2 mice, two spontaneous SS models. Oral GABA treatment was initiated (1) after the development of sialadenitis but before the onset of overt symptoms, or (2) after the appearance of overt symptoms. When assessed weeks later, GABA-treated mice had greater saliva and tear production, as well as quicker times to salvia flow, in both SS mouse models. This was especially evident when GABA treatment was initiated after the onset of overt disease. This preservation of exocrine function was not accompanied by significant changes in the number or area of lymphocytic foci in the salivary or lachrymal glands of GABA-treated mice and we discuss the possible reasons for these observations. Given that GABA-treatment preserved saliva and tear production which are the most salient symptoms of SS and is safe for consumption, it may provide a new approach to help ameliorate SS.