bluuebunny/crossref_metadata_2025 huggingface dataset:
Climate change reshapes plant trait spectrum to explain biomass dynamics in an old-growth subtropical forest
Authors: Wu Anchi , Xiong Xin , González-M Roy , Li Ronghua , Li Andi , Liu Juxiu , Tang Xuli , Zhang Qianmei
Published: November 2023

Climate change leads to novel species interactions and continues to reshuffle ecological communities, which significantly declines carbon accumulation rates in mature forests. Still, little is known about the potential influence of multiple global change factors on long-term biomass dynamics and functional trait combinations. We used temporal demographic records spanning 26 years and extensive databases of functional traits to assess how old-growth subtropical forest biomass dynamics respond to various climatic change scenarios (extreme drought, subsequent drought, warming, elevated CO2 concentrations, and windstorm). We found that the initial severe drought, subsequent drought and windstorm events increased biomass loss due to tree mortality, which exceeded the biomass gain produced by survivors and recruits, ultimately resulting in more negative net biomass balances. These drought and windstorm events caused massive biomass loss due to tree mortality that tended towards acquisition species with high hydraulic efficiency, whereas biomass growth from survivors and recruits tended to consist of acquisition species with high hydraulic safety. Compensatory growth in this natural forest provided good explanation for the increase in biomass growth after drought and windstorm events. Notably, these dominant-species transitions reduced carbon storage and residence time, forming a positive carbon-climate feedback loop. Our findings suggest that climate changes could alter functional strategies and cause shifts in new dominant species, which could greatly reduce ecological functions and carbon gains of old-growth subtropical forests.
How task difficulty and academic self-efficacy impact retrieval practice guidance
Authors: Liao Chenchen , Zhang Jinkun
Published: November 2023

Retrieval practice can enhance learning but is rarely used in self-regulated learning. Although explicit retrieval practice guidance (RPG)—which helps students use retrieval correctly—can improve learning outcomes, however, task difficulty and differences in academic self-efficacy (ASE) may influence retrieval practice decisions and learning performance, which were not considered in previous researches. The purpose of this study was to explore whether RPG produces different effects due to task difficulty and ASE. In Experiment 1, participants studied tasks with varying difficulty levels, some of which were guided. Results showed that RPG could enhance learning through increased retrieval practice, and participants engaged in more retrieval for difficult tasks. In Experiment 2, participants with different degrees of ASE learned tasks under guidance. Participants with high ASE persisted better on different tasks. Hence, task difficulty can affect retrieval practice decisions, and ASE increases persistence in retrieval practice. The implications of the findings for students’ use of RPG are discussed in this article.
Mental Fatigue: What Happens When Your Brain Is Tired?
Authors: Jacquet Thomas , Lepers Romuald
Published: November 2023

Have you ever felt tired after a day at school? That feeling you get from doing tasks that need a lot of attention and focus is called mental fatigue. Scientists created tasks in their laboratories to study this feeling. They observed that when we are mentally tired, both our thinking abilities and physical performance become worse. Scientists are not exactly sure why this happens, but mental fatigue can cause changes in the brain. One small brain region located in the front of the brain, called the anterior cingulate cortex, becomes less active when we are mentally tired. This can make us feel like we do not want to put as much effort into doing things, and that is why our performance declines. The good news is that scientists found ways to reduce mental fatigue. Paying attention to the present moment, listening to music, doing physical exercise, or having caffeine can make people feel better.
Practical Adaptive Fast Terminal Sliding Mode Control for Servo Motors
Authors: Ali Kamran , Cao Zhenwei , Rsetam Kamal , Man Zhihong
Published: November 2023

Position control of servo motor systems is a challenging task because of inevitable factors such as uncertainties, nonlinearities, parametric variations, and external perturbations. In this article, to alleviate the above issues, a practical adaptive fast terminal sliding mode control (PAFTSMC) is proposed for better tracking performance of the servo motor system by using a state observer and bidirectional adaptive law. First, a smooth-tangent-hyperbolic-function-based practical fast terminal sliding mode control (PFTSM) surface is designed to ensure not only fast finite time tracking error convergence but also chattering reduction. Second, the PAFTSMC is proposed for the servo motor, in which a two-way adaptive law is designed to further suppress the chattering and overestimation problems. More importantly, the proposed adaptive technique can update the switching gain according to the system uncertainties, which can provide high gain in the reaching phase and then decrease to the smallest value in the sliding phase to avoid the monotonically increasing gain that exists in most adaptation methods. Third, the finite-time stability of the closed-loop system is proved based on the Lyapunov theorem. Finally, the simulation studies and experimental tests verify the effectiveness of the proposed control in terms of better tracking, strong robustness, and reduced chattering, compared to existing algorithms.
Characteristics of a Heat Exchanger in a Liquid Rocket Engine Using Conjugate Heat Transfer Coupling with Open-Source Tools
Authors: Jeong Wooseok , Jang Seungeon , Kim Hong-Jip
Published: November 2023

Since a heat exchanger used in a gas generator of an open-cycle liquid rocket engine was operated in a high-temperature environment, the coupled analysis for heat transfer characteristics and structural integrity should be performed simultaneously. For these reasons, a numerical analysis of the heat exchanger in a liquid rocket engine was performed to elucidate the effects of heat transfer and structural deformation simultaneously using conjugate heat transfer (CHT) analysis and open-source tools. For the baseline heat exchanger, which had an inner helically coiled tube with nine turns (Nc=9), the heat transfer characteristics were investigated and findings showed that the heat transfer performance was reduced from the sixth turn. Further analysis was performed to examine the effect of the number of turns in terms of heat flux and the corresponding pressure drop and the weight of the structure. The results indicated that the heat exchanger with Nc=3 had a significantly reduced outlet temperature due to an excessively shortened flow residence time. The heat exchanger with Nc=6 showed an outlet temperature similar to that of the baseline; it also presented advantages in terms of the pressure drop and structure weight. In addition, the thermal deformation and stress caused by temperature changes were numerically investigated to consider the structural integrity of the heat exchanger with Nc=3,6,9. Further numerical analyses were performed at various flow rates. As the flow rate of helium increased, the amount of heat received from the high-temperature exhaust gas from the gas generator increased but the outlet temperature of helium decreased gradually. Finally, the temperature difference between the outer and inner walls increased due to the high heat flux in the region around the inlet, resulting in an increase in thermal stress. Based on these results, the optimal shape and flow rate of the system were identified. Furthermore, the heat transfer performance was found to correlate with the flow characteristics of the coiled tube.
Numerical Analysis of Friction-Filling Performance of Friction-Type Vertical Disc Precision Seed-Metering Device Based on EDEM
Authors: Wang Yecheng , Kang Xueqi , Wang Guoqing , Ji Wenyi
Published: November 2023

A seed-metering device is a key component for precision seeding and the core component of precision seed-metering devices. Nowadays, high-speed seeding is a trend in the development of seed-metering devices, but the filling performance of mechanical seed-metering devices decreases under the condition of high speed. Therefore, this paper explores a controllable method to improve the filling force of seeds, thereby increasing the limit operation speed of the existing mechanical seed-metering devices, so as to achieve high-speed seeding. The friction-filling method of friction vertical disc precision seed-metering devices was numerically simulated using the DEM. In this paper, the relationship between the relevant parameters and seed-filling force was confirmed via comparing theoretical formulas. The friction-filling method was studied via numerical simulation and experimental verification. This research demonstrated that during the process of friction filling, the pressure on the side wall of the tube increased with the e exponent with the change in the position of the particles. When the friction coefficient between the particles and the side wall is less than the friction coefficient between the particles, the e exponent increases. A surge occurs when the ratio of the square tube side length to the particle radius is n3+2(n=1,2,3).
Identification of Box Scale and Root Placement for Paddy–Wheat Root System Architecture Using the Box Counting Method
Authors: Liu Shulin , Chen Xinxin , Hu Jianping , Ding Qishuo , He Ruiyin
Published: November 2023

Root fractal analysis is instrumental in comprehending the intricate structures of plant root systems, offering insights into root morphology, branching patterns, and resource acquisition efficiency. We conducted a field experiment on paddy–wheat root systems under varying nitrogen fertilizer strategies to address the need for quantitative standardization in root fractal analysis. The study evaluated the impact of nitrogen fertilizer heterogeneity on root length and number. We established functional relationships and correlations among root fractal characteristics and root length across different box dimension scales and various root placement angles at 2.5, 5, 10, 20, 40, and 80 box dimension scales. Results indicated that nitrogen fertilizer had a limited impact on paddy–wheat axile roots, with a coefficient of variation below 0.35 among samples. Box dimension scale influenced 3D fractal dimension (FD) and fractal abundance (FA), with strong correlations (>78%) among 3D fractal features and low sample errors (<6%). The linear correlation coefficient exceeded 72% between 3D FA and root length and 50% between FA and FD. Different axile root placement angles significantly impacted planar fractal results, particularly at a 10° angle. This stability was maintained throughout the sampling period, with high correlation coefficients (>0.76 for FA and >0.5 for FD) and low sample errors (<1.5% for FA and <4.5% for FD). In conclusion, for calculating the 3D fractal characteristics of paddy–wheat axile roots during the seedling stage, box dimension scales of 2.5, 5, 10, 20, 40, and 80, as well as 2, 5, 10, 20, 50 and 100 and 3, 6, 12, 24, 48 and 96, were suitable. When computing the planar fractal characteristics of paddy–wheat axile roots during this stage, a 10° placement angle between axile root systems yields lower errors. These findings enhance root quantification methods, standardize root analysis, and promote the comparability of crop root system fractal data across different varieties and regions, thereby advancing root-related research.
A Review of Rural Household Energy Poverty: Identification, Causes and Governance
Authors: Lin Li , Wang Zhihai , Liu Jiaxiang , Xu Xiaocang
Published: November 2023

Energy poverty is one of the three major crises of the global energy system. It tends to deepen as a result of the imbalance between supply and demand, energy transition and financial factors, especially in rural areas of developing countries. This paper took rural household energy poverty as the subject and collected 27 Chinese papers and 44 English papers from Google Scholar, Sci-hub, CNKI and other academic websites in the academic field on the definition, identification methods, influencing factors and governance countermeasures of energy poverty. It focused on analyzing the influence of income level, geographic location, urban–rural differences, demographic characteristics and other factors on energy poverty, as well as the profound impact of energy poverty on the population’s health, the population’s economic status, social equity, welfare of the population, the national economic development, etc. It finally landed on the government’s countermeasures to govern energy poverty so as to provide references for solving the problem of energy poverty by systematically sorting out the literature.
Culturomics and Amplicon-Based Metagenomic Insights into the Bacteria of Soils with High Yield of Oryza sativa L. subsp. Japonica
Authors: Zhang Li , Cao Qingmei , Ruan Wenzhong , Guo Yapeng , Zhuang Yan , Li Yan , Ruan Zhiyong
Published: November 2023

The bacterial community in the paddy field agroecosystem has a pivotal role in the growth adaptability strategy of rice. Here, we studied the bacterial community structure composition of rhizosphere and non-rhizosphere soil samples from super rice in high-yield (920.99 kg/mu) and low-yield (785.30 kg/mu) fields of Japonica Chu 54 using both culturomics and amplicon-based metagenomics approaches. Using amplicon sequencing, a total of 54 phyla and 1167 genera of high-yield field bacteria were detected, while the low-yield field bacteria were distributed in 49 phyla and 865 genera. In addition, compared with low-yielding fields, there were significant differences in the composition and abundance of the same members in high-yielding fields. The node microorganisms in high-yield and low-yield fields were Anaeromyxobacterium and HSB_OF53-F07, respectively. Culturomics analysis unveiled a diverse array of bacterial taxa, encompassing four phyla, 113 genera, and 331 species, including 33 new undescribed lineages. The culturomics and high-throughput sequencing results indicate a widely adapted and highly abundant group of Exiguobacterium, which has broad prospects for application due to its extensive survival characteristics and plant growth-promoting functions. In summary, we analyze the bacterial community structure composition of rhizosphere and non-rhizosphere soil samples from super rice in high-yield and low-yield fields of Japonica Chu 54 using culturomics and amplicon sequencing techniques to better develop positive promotion strategies that adapt to its unique ecological environment.
Delineation of Productive Zones in Eastern China Based on Multiple Soil Properties
Authors: Tong Tong , Mei Shuai , Cao Chi , Legesse Nebiyou , Chang Junfeng , Ying Chunyang , Ma Youhua , Wang Qingyun
Published: November 2023

Accurate soil management has long been the focus of research in agroecology. Crop productivity can be enhanced while reducing environmental threats from excessive fertilization by fully comprehending the spatial variability of soil properties and delineating management zones (MZs). A field investigation was carried out at experimental sites outside Hefei City’s administrative districts in China to study the spatial variability of soil properties and the delineation of MZs. A total of 9601 soil samples were collected in the study area. A variety of soil properties were analyzed, including the pH, organic matter, total nitrogen, alkali-hydrolyzable nitrogen, available phosphorus, available potassium, slowly released potassium, available sulfur, available boron, available copper, available zinc, available iron, and available manganese. The coefficient of variation for various soil properties exhibited a wide range, spanning from 12.2% to 100.5%. The geostatistical results show that most soil properties have moderate to strong spatial autocorrelation, and the ordinary kriging method is used to map the distribution of soil properties. The principal component analysis method was used to reduce the dimension of 13 soil properties to 4 principal components, and the fuzzy c-means clustering method was used to delineate MZs. The calculation results of the fuzzy performance index and normalized classification entropy show that the optimum number of MZs is five. In the study area, the western part exhibits the highest soil fertility, primarily attributed to its elevated organic matter content. Additionally, organic matter emerges as a key factor influencing sustainable agricultural production in this region. These results form the basis for soil managing areas outside the administrative districts of Hefei City.
6-Pentyl-α-Pyrone from Trichoderma gamsii Exert Antioxidant and Anti-Inflammatory Properties in Lipopolysaccharide-Stimulated Mouse Macrophages
Authors: Lim Jae Sung , Hong Joo-Hyun , Lee Da Young , Li Xiangying , Lee Da Eun , Choi Jeong Uk , Lee Kwang Youl , Kim Ki Hyun , Cho Young-Chang
Published: November 2023

Filamentous fungi produce several beneficial secondary metabolites, including bioactive compounds, food additives, and biofuels. Trichoderma, which is a teleomorphic Hypocrea that falls under the taxonomic groups Ascomycota and Dikarya, is an extensively studied fungal genus. In an ongoing study that seeks to discover bioactive natural products, we investigated potential bioactive metabolites from the methanolic extract of cultured Trichoderma gamsii. Using liquid chromatography–mass spectrometry (LC–MS), one major compound was isolated and structurally identified as 6-pentyl-α-pyrone (6PP) based on nuclear magnetic resonance data and LC–MS analysis. To determine its antioxidant and anti-inflammatory activity, as well as the underlying mechanisms, we treated lipopolysaccharide (LPS)-stimulated Raw264.7 mouse macrophages with 6PP. We found that 6PP suppresses LPS-induced increase in the levels of nitric oxide, a mediator of oxidative stress and inflammation, and restores LPS-mediated depletion of total glutathione by stabilizing nuclear factor erythroid 2-related factor 2 (Nrf2), an antioxidative factor, and elevating heme oxygenase-1 levels. Furthermore, 6PP inhibited LPS-induced production of proinflammatory cytokines, which are, at least in part, regulated by heme oxygenase-1 (HO-1). 6PP suppressed proinflammatory responses by inhibiting the nuclear localization of nuclear factor kappa B (NF-κB), as well as by dephosphorylating the mitogen-activated protein kinases (MAPKs). These results indicate that 6PP can protect macrophages against oxidative stress and LPS-induced excessive inflammatory responses by activating the Nrf2/HO-1 pathway while inhibiting the proinflammatory, NF-κB, and MAPK pathways.
A Review of Demand-Side Resources in Active Distribution Systems: Communication Protocols, Smart Metering, Control, Automation, and Optimization
Authors: Ratshitanga Mukovhe , Orumwense Efe F. , Krishnamurthy Senthil , Melamu Moteane
Published: November 2023

Power systems have been going through a barrage of transformations due to the recent developments in the field, such as deregulation and restructuring of the electric power supply chain, the proliferation of distributed generation (DG), and advancements in information and communications technologies. These have significantly impacted the approach to the planning, design, and operation of active distribution networks or systems. Due to this constant change, the system has become more complex to plan, maintain, and control. In this paper, the benefits and challenges of active distribution systems relative to traditional passive and active distribution systems are evaluated and investigated while the management and operational characteristics of demand-side resources in active distribution systems (ADS) are studied. In a typical ADS, there exist several vulnerabilities and threats that eventually pose a challenge in the control and automation of substations. These vulnerabilities and threats are reviewed, and potential mitigation measures are suggested. Also in this paper, the communication technologies and their implementation in terms of control and automation capabilities in active distribution networks are also studied. From this work, it is concluded that communication technologies play an integral role in the realization of more active distribution networks and that the Internet of Energy (IoE) is a major player in ADS in the reduction of faults due to human error, fast responses, and improving the stability of power supply. Cyber threats are also and will still be a continuous challenge in smart metering technologies and in substation automation systems (SAS), which will require frequent evaluation and mitigation measures so as not to prevent the power supply system from collapsing.
Infrared Image Enhancement Using Convolutional Neural Networks for Auto-Driving
Authors: Zhong Shunshun , Fu Luowei , Zhang Fan
Published: November 2023

Auto-driving detection usually acquires low-light infrared images, which pose a great challenge to the autopilot function at night due to their low contrast and unclear texture details. As a precursor algorithm in the field of automatic driving, the infrared image contrast enhancement method is of great significance in accelerating the operation speed of automatic driving target recognition algorithms and improving the accuracy of object localization. In this study, a convolutional neural network model including feature extraction and image enhancement modules is proposed to enhance infrared images. Specifically, the feature extraction module consists of three branches, a concatenation layer, and a fusion layer that connect in parallel to extract the feature images. The image enhancement module contains eight convolutional layers, one connectivity layer, and one difference layer for enhancing contrast in infrared images. In order to overcome the problem of the lack of a large amount of training data and to improve the accuracy of the model, the brightness and sharpness of the infrared images are randomly transformed to expand the number of pictures in the training set and form more sample pairs. Unlike traditional enhancement methods, the proposed model directly learns the end-to-end mapping between low- and high-contrast images. Extensive experiments from qualitative and quantitative perspectives demonstrate that our method can achieve better clarity in a shorter time.
Prediction of the Crack Front Shape of the Corner Interface Crack
Authors: Djoković Jelena M. , Nikolić Ružica R. , Pastorková Jana , Ulewicz Robert
Published: November 2023

This study delves into the analysis of interface crack propagation originating from a right-angle corner along the bonding plane between the two plates composed of dissimilar materials. The research explores three distinct crack front shapes: concave, triangular, and convex (quarter-circle). The obtained results, meticulously presented in this paper, offer valuable insights into the nature of the crack propagation along these geometries. The findings elucidate that in the case of a convex crack front, the edges demonstrate a significantly accelerated propagation compared to the rest of the crack front. Conversely, for the triangular and concave crack fronts, the central region experiences faster propagation compared to the edges. These revelations lead to a generalized conclusion regarding the stability of different crack front shapes, highlighting the triangular crack front as the most stable configuration in this context. The implications of these observations provide essential knowledge for understanding and managing crack propagation in composite structures, offering potential applications in various engineering domains.
Elastoplastic Analysis of Frame Structures Using Radial Point Interpolation Meshless Methods
Authors: Belinha Jorge , Aires Miguel , Rodrigues Daniel E.S.
Published: November 2023

The need to design structures and structural elements that are more efficient in terms of performance is a key aspect of engineering. For a given material to be used at its maximum capacity, considering non-linear characteristics is mandatory. The non-linear regime is a subject of extreme interest for this reason and is an area with intense research activity. In this work, advanced discretization techniques (i.e., meshless methods) are applied in the elastoplastic analysis of 2D and 3D structural elements. The literature shows that meshless methods are capable of producing more accurate and smoother strain and stress fields, which are the variable fields required in the non-linear models describing elastoplasticity. Thus, in this study, the Radial Point Interpolation Method (RPIM) and the Natural Neighbor Radial Point Interpolation Method (NNRPIM) are combined with a non-linear iterative algorithm, fully developed by the authors, with the objective of analyzing for the first time the elastoplastic behavior of a two-bay asymmetric frame and bowstring bridge considering 2D and 3D analysis. The accuracy and robustness of the RPIM and the NNRPIM are shown in the end, comparing the obtained results with FEM solutions and the available literature.
A New Shallow-Water Species of the Rare Shrimp Genus Bresilia from Cabo Verde (Crustacea, Decapoda, Bresiliidae) †
Authors: De Grave Sammy , Wirtz Peter , Anker Arthur
Published: November 2023

A new species of the rare shrimp genus Bresilia is described and illustrated from shallow-water lava tubes in Cabo Verde. Characteristics differentiating the new species from its three known Atlantic congeners are listed and discussed. Scanning electron images (SEM) are provided of the peculiar chela ornamentation of the first pereiopod in the genus.
Transgenerational Epigenetic DNA Methylation Editing and Human Disease
Authors: Tompkins Joshua D.
Published: November 2023

During gestation, maternal (F0), embryonic (F1), and migrating primordial germ cell (F2) genomes can be simultaneously exposed to environmental influences. Accumulating evidence suggests that operating epi- or above the genetic DNA sequence, covalent DNA methylation (DNAme) can be recorded onto DNA in response to environmental insults, some sites which escape normal germline erasure. These appear to intrinsically regulate future disease propensity, even transgenerationally. Thus, an organism’s genome can undergo epigenetic adjustment based on environmental influences experienced by prior generations. During the earliest stages of mammalian development, the three-dimensional presentation of the genome is dramatically changed, and DNAme is removed genome wide. Why, then, do some pathological DNAme patterns appear to be heritable? Are these correctable? In the following sections, I review concepts of transgenerational epigenetics and recent work towards programming transgenerational DNAme. A framework for editing heritable DNAme and challenges are discussed, and ethics in human research is introduced.
Gene Signature Associated with Nervous System in an Experimental Radiation- and Estrogen-Induced Breast Cancer Model
Authors: Calaf Gloria M. , Roy Debasish , Jara Lilian , Aguayo Francisco , Crispin Leodan A.
Published: November 2023

Breast cancer is frequently the most diagnosed female cancer in the world. The experimental studies on cancer seldom focus on the relationship between the central nervous system and cancer. Despite extensive research into the treatment of breast cancer, chemotherapy resistance is an important issue limiting the efficacy of treatment. Novel biomarkers to predict prognosis or sensitivity to chemotherapy are urgently needed. This study examined nervous-system-related genes. The profiling of differentially expressed genes indicated that high-LET radiation, such as that emitted by radon progeny, in the presence of estrogen, induced a cascade of events indicative of tumorigenicity in human breast epithelial cells. Bioinformatic tools allowed us to analyze the genes involved in breast cancer and associated with the nervous system. The results indicated that the gene expression of the Ephrin A1 gene (EFNA1), the roundabout guidance receptor 1 (ROBO1), and the kallikrein-related peptidase 6 (KLK6) was greater in T2 and A5 than in the A3 cell line; the LIM domain kinase 2 gene (LIMK2) was greater in T2 than A3 and A5; the kallikrein-related peptidase 7 (KLK7), the neuroligin 4 X-linked gene (NLGN4X), and myelin basic protein (MBP) were greater than A3 only in T2; and the neural precursor cell expressed, developmentally down-regulated 9 gene (NEDD9) was greater in A5 than in the A3 and E cell lines. Concerning the correlation, it was found a positive correlation between ESR1 and EFNA1 in BRCA-LumA patients; with ROBO1 in BRCA-Basal patients, but this correlation was negative with the kallikrein-related peptidase 6 (KLK6) in BRCA-LumA and –LumB, as well as with LIMK2 and ROBO1 in all BRCA. It was also positive with neuroligin 4 X-linked (NLGN4X) in BRCA-Her2 and BRCA-LumB, and with MBP in BRCA-LumA and –LumB, but negative with KLK7 in all BRCA and BRCA-LumA and NEDD9 in BRCA-Her2. The differential gene expression levels between the tumor and adjacent tissue indicated that the ROBO1, KLK6, LIMK2, KLK7, NLGN4X, MBP, and NEDD9 gene expression levels were higher in normal tissues than in tumors; however, EFNA1 was higher in the tumor than the normal ones. EFNA1, LIMK2, ROBO1, KLK6, KLK7, and MBP gene expression had a negative ER status, whereas NEDD9 and NLGN4X were not significant concerning ER status. In conclusion, important markers have been analyzed concerning genes related to the nervous system, opening up a new avenue of studies in breast cancer therapy.
Epidemiology and Management of Hypertension and Diabetes Mellitus in Patients with Mild Autonomous Cortisol Secretion: A Review
Authors: Araujo-Castro Marta , Reincke Martin , Lamas Cristina
Published: November 2023

Mild autonomous cortisol secretion (MACS) is associated with a higher cardiometabolic risk than that observed in patients with nonfunctioning adrenal adenomas and in the general population. In patients with MACS, the excess of glucocorticoids affects various metabolic pathways, leading to different manifestations of metabolic syndrome and other comorbidities. Hypertension and diabetes mellitus are two of the most common cardiometabolic comorbidities associated with MACS, reaching a prevalence of up to 80% and up to 40%, respectively. In addition, they are the comorbidities that experienced a greater improvement after adrenalectomy in patients with MACS. Hypertension pathogenesis is multifactorial, including the coexistence of comorbidities such as obesity or diabetes and the role of the different polymorphisms of the glucocorticoid receptor gene, among others. Glucocorticoid-induced diabetes mellitus is mainly related to the detrimental effects of glucocorticoids on insulin-dependent glucose uptake in peripheral tissues, gluconeogenesis and insulin secretion. There are no specific recommendations for hypertension and diabetes treatment in patients with MACS. Thus, considering the similar underlying pathogenesis of hypertension and diabetes mellitus in overt and mild hypercortisolism, our recommendation is to follow this general stepwise approach: surgically remove the adrenal culprit lesion to induce remission from hypercortisolism; control hypercortisolism with steroidogenesis inhibitors; and treat elevated blood pressure or high glucose levels using carefully selected anti-hypertensives and glucose-lowering medications if blood pressure and glucose levels remain uncontrolled, respectively. In this review, we summarize the epidemiology, physiopathology and management of diabetes mellitus and hypertension in patients with MACS.
Antiphospholipid Antibodies and Vascular Thrombosis in Patients with Severe Forms of COVID-19
Authors: Zlatković-Švenda Mirjana , Ovuka Milica , Ogrič Manca , Čučnik Saša , Žigon Polona , Radivčev Aleksandar , Zdravković Marija , Radunović Goran
Published: November 2023

Antiphospholipid antibodies (aPLA) are a laboratory criterion for the classification of antiphospholipid syndrome (APS) and are known to cause clinical symptoms such as vascular thrombosis or obstetric complications. It is suggested that aPLA may be associated with thromboembolism in severe COVID-19 cases. Therefore, we aimed to combine clinical data with laboratory findings of aPLA at four time points (admission, worsening, discharge, and 3-month follow-up) in patients hospitalized with COVID-19 pneumonia. In 111 patients with COVID-19 pneumonia, current and past history of thrombosis and pregnancy complications were recorded. Nine types of aPLA were determined at four time points: anticardiolipin (aCL), anti-β2-glycoprotein I (anti- β2GPI), and antiphosphatidylserine/prothrombin (aPS/PT) of the IgM, IgG, or IgA isotypes. During hospitalization, seven patients died, three of them due to pulmonary artery thromboembolism (none were aPLA positive). Only one of the five who developed pulmonary artery thrombosis was aPLA positive. Out of 9/101 patients with a history of thrombosis, five had arterial thrombosis and none were aPLA positive at admission and follow-up; four had venous thrombosis, and one was aPLA positive at all time points (newly diagnosed APS). Of these 9/101 patients, 55.6% were transiently aPLA positive at discharge only, compared to 26.1% without a history of thrombosis (p = 0.041). Patients with severe forms of COVID-19 and positive aPLA should receive the same dose and anticoagulant medication regimen as those with negative aPLA because those antibodies are mostly transiently positive and not linked to thrombosis and fatal outcomes.
Experimental Study and Finite Element Analysis on the Modification of Fast-Hardening Polymer Cement Composite Material Applied to the Anchorage Zone of Expansion Joint
Authors: Sun Hang , Yuan Huan , Sun Yongming , Li Xi , Luo Liang
Published: November 2023

Bridges’ expansion joints are prone to damage during operation, and repairing them often requires interruption of traffic, the impact of which can be minimized by using fast-hardening and early-strength expansion joint materials. In this study, a fast-hardening polymer cement composite (PCC) was developed using sulfate aluminate cement and ordinary silicate cement as binding agents and polymer powder as admixture. To improve the crack resistance of the material, several types of fibers were added and the effects of different fiber types and admixtures on the crack resistance of the material were compared using SCB tests. The results showed that the best effect of improving the crack resistance of concrete was achieved with a volume fraction of 0.5% of basalt fibers. Then, a test method for the interfacial shear properties of PCC materials and ordinary concrete was established, and the cohesive force model was selected as the interface simulation parameter for finite element analysis and compared with experimental data to verify its feasibility. Finally, based on the previously obtained PCC material parameters, a solid model of the expansion joint anchorage zone was established to study the mechanical properties of the expansion joint anchorage zone with the application of fast-hardening PCC material. This research provides a new way to develop fast-hardening and early-strength expansion joint materials with high crack resistance.
C-Type Lectin-like Receptor 2 Expression Is Decreased upon Platelet Activation and Is Lower in Most Tumor Entities Compared to Healthy Controls
Authors: Etemad Mani , Christodoulou Foteini , Uhlig Stefanie , Hassel Jessica C. , Schrotz-King Petra , Brenner Hermann , Ulrich Cornelia M. , Bieback Karen , Klüter Harald , Bugert Peter
Published: November 2023

The C-type lectin-like receptor 2 (CLEC-2) is expressed on platelets and mediates binding to podoplanin (PDPN) on various cell types. The binding to circulating tumor cells (CTCs) leads to platelet activation and promotes metastatic spread. An increased level of soluble CLEC-2 (sCLEC-2), presumably released from activated platelets, was shown in patients with thromboinflammatory and malignant disease. However, the functional role of sCLEC-2 and the mechanism of sCLEC-2 release are not known. In this study, we focused on the effect of platelet activation on CLEC-2 expression and the sCLEC-2 plasma level in patients with cancer. First, citrated blood from healthy volunteer donors (n = 20) was used to measure the effect of platelet stimulation by classical agonists and PDPN on aggregation, CLEC-2 expression on platelets with flow cytometry, sCLEC-2 release to the plasma with ELISA and total CLEC-2 expression with Western blot analysis. Second, sCLEC-2 was determined in plasma samples from healthy donors (285) and patients with colorectal carcinoma (CRC; 194), melanoma (160), breast cancer (BC; 99) or glioblastoma (49). PDPN caused a significant increase in the aggregation response induced by classical agonists. ADP or PDPN stimulation of platelets caused a significant decrease in CLEC-2 on platelets and sCLEC-2 in the plasma, whereas total CLEC-2 in platelet lysates remained the same. Thus, the increased plasma level of sCLEC-2 is not a suitable biomarker of platelet activation. In patients with CRC (median 0.9 ng/mL), melanoma (0.9 ng/mL) or BC (0.7 ng/mL), we found significantly lower sCLEC-2 levels (p < 0.0001), whereas patients with glioblastoma displayed higher levels (2.6 ng/mL; p = 0.0233) compared to healthy controls (2.1 ng/mL). The low sCLEC-2 plasma level observed in most of the tumor entities of our study presumably results from the internalization of sCLEC-2 by activated platelets or binding of sCLEC-2 to CTCs.
Pituitary Tumors: Molecular Insights, Diagnosis, and Targeted Therapy
Authors: Kageyama Kazunori , Nishiyama Mitsuru
Published: November 2023

The anterior pituitary gland comprises a heterogeneous population of pituitary cells [...]
Aerosol-Assisted Synthesis of Sn–Si Composite Oxide Microspheres with the Hollow Mesoporous Structure for Baeyer–Villiger Oxidation
Authors: Meng Qingrun , Gao Xiaoxu , Sun Ting , Guo Yu , Liu Huimin
Published: November 2023

Tetravalent Sn species, such as zeolite or oxide, possess Lewis acidic properties, and thus exhibit prominent catalytic performance in several reactions when they are incorporated into the silica framework. Unfortunately, the synthesis of Sn-based zeolite (Sn–Beta) usually suffers from several drawbacks, including a long crystallization time, limited framework Sn content and complex synthesis steps. Sn-based composite oxides are favored in the industry, due to their simple synthesis steps and easy control of their pore structure, morphology and Sn content. In this work, an aerosol-assisted method is used to prepare Sn–Si composite oxide microspheres, using CTAB as template. The method is based on the formation of aerosol from a solution of Sn, Si precursors and a template (CTAB). The introduction of CTAB causes the surface tension of the atomized droplets to decrease. During the fast drying of the droplets, the Sn–Si composite oxide microspheres with a concave hollow morphology were first formed. After calcination, calibrated mesopores of 2.3 nm were also formed, with a specific surface area of 1260 m2/g and a mesopores ratio of 0.84. Sn species are incorporated in the silica network, mainly in the form of single sites. The resulting material proved to exhibit high catalytic performances in the Baeyer–Villiger oxidation of 2-adamantanone by using H2O2 as green oxidant, which was mainly attributed to the enhancement of the access to the catalytic tin sites through both the continuous hollow and mesopore channels, which have a 52% conversion of 2-adamantanone after 3 h of reaction. This method is simple, convenient, cheap and can be continuously produced, meaning it has broad potential for industrial application.
Metabolic Profiles of Cancer Stem Cells and Normal Stem Cells and Their Therapeutic Significance
Authors: Stouras Ioannis , Vasileiou Maria , Kanatas Panagiotis F. , Tziona Eleni , Tsianava Christina , Theocharis Stamatis
Published: November 2023

Cancer stem cells (CSCs) are a rare cancer cell population, responsible for the facilitation, progression, and resistance of tumors to therapeutic interventions. This subset of cancer cells with stemness and tumorigenic properties is organized in niches within the tumor microenvironment (TME) and presents altered regulation in a variety of metabolic pathways, including glycolysis, oxidative phosphorylation (OXPHOS), as well as lipid, amino acid, and iron metabolism. CSCs exhibit similarities as well as differences when comparedto normal stem cells, but also possess the ability of metabolic plasticity. In this review, we summarize the metabolic characteristics of normal, non-cancerous stem cells and CSCs. We also highlight the significance and implications of interventions targeting CSC metabolism to potentially achieve more robust clinical responses in the future.
Specification and Description Language Models Automatic Execution in a High-Performance Environment
Authors: Fonseca i Casas Pau , Romanowska Iza , Garcia i Subirana Joan
Published: November 2023

Specification and Description Language (SDL) is a language that can represent the behavior and structure of a model completely and unambiguously. It allows the creation of frameworks that can run a model without the need to code it in a specific programming language. This automatic process simplifies the key phases of model building: validation and verification. SDLPS is a simulator that enables the definition and execution of models using SDL. In this paper, we present a new library that enables the execution of SDL models defined on SDLPS infrastructure on a HPC platform, such as a supercomputer, thus significantly speeding up simulation runtime. Moreover, we apply the SDL language to a social science use case, thus opening a new avenue for facilitating the use of HPC power to new groups of users. The tools presented here have the potential to increase the robustness of modeling software by improving the documentation, verification, and validation of the models.
Nanoscale Self-Assemblies from Amphiphilic Block Copolymers as Proficient Templates in Drug Delivery
Authors: Patel Dhruvi , Kuperkar Ketan , Yusa Shin-ichi , Bahadur Pratap
Published: November 2023

This review article emphasizes the current enlargements in the formation and properties of the various nanostructured aggregates resulting from the self-assembly of a variety of block copolymers (BCPs) in an aqueous solution. The development of the different polymerization techniques which produce polymers with a desired predetermined molecular weight and low polydispersity is investigated with regard to their technological and biomedical applications; in particular, their applications as vehicles for drug delivery systems are considered. The solution behavior of amphiphilic BCPs and double-hydrophilic block copolymers (DHBCs), with one or both blocks being responsive to any stimulus, is discussed. Polyion complex micelles (PICMs)/polymersomes obtained from the electrostatic interaction of a polyelectrolyte-neutral BCP with oppositely charged species are also detailed. Lastly, polymerization-induced self-assembly (PISA), which forms nanoscale micellar aggregates with controlled size/shape/surface functionality, and the crystallization-driven self-assembly of semicrystalline BCPs facilitated when one block of the BCP is crystallizable, are also revealed. The scalability of the copolymeric micelles in the drug delivery systems and pharmaceutical formations that are currently being used in clinical trials, research, or preclinical testing is emphasized as these micelles could be used in the future to create novel nanomedicines. The updated literature and the future perspectives of BCP self-assembly are considered.
Neural Adaptive H∞ Sliding-Mode Control for Uncertain Nonlinear Systems with Disturbances Using Adaptive Dynamic Programming
Authors: Huang Yuzhu , Zhang Zhaoyan
Published: November 2023

This paper focuses on a neural adaptive H∞ sliding-mode control scheme for a class of uncertain nonlinear systems subject to external disturbances by the aid of adaptive dynamic programming (ADP). First, by combining the neural network (NN) approximation method with a nonlinear disturbance observer, an enhanced observer framework is developed for estimating the system uncertainties and observing the external disturbances simultaneously. Then, based on the reliable estimations provided by the enhanced observer, an adaptive sliding-mode controller is meticulously designed, which can effectively counteract the effects of the system uncertainties and the separated matched disturbances, even in the absence of prior knowledge regarding their upper bounds. While the remaining unmatched disturbances are attenuated by means of H∞ control performance on the sliding surface. Moreover, a single critic network-based ADP algorithm is employed to learn the cost function related to the Hamilton–Jacobi–Isaacs equation, and thus, the H∞ optimal control is obtained. An updated law for the critic NN is proposed not only to make the Nash equilibrium achieved, but also to stabilize the sliding-mode dynamics without the need for an initial stabilizing control. In addition, we analyze the uniform ultimate boundedness stability of the resultant closed-loop system via Lyapunov’s method. Finally, the effectiveness of the proposed scheme is verified through simulations of a single-link robot arm and a power system.
Direct Numerical Simulation of a Reacting Turbulent Hydrogen/Ammonia/Nitrogen Jet in an Air Crossflow at 5 Bar
Authors: Giacomazzi Eugenio , Cecere Donato , Cimini Matteo , Carpenella Simone
Published: November 2023

The article aims to analyze the fluid dynamics and combustion characteristics of a non-premixed flame burning a fuel mixture derived from ammonia partial decomposition injected in an air crossflow. Nominal pressure (5 bar) and inlet air temperature (750 K) conditions are typical of micro-gas turbines. The effects of strain on the maximum flame temperature and NO generation in laminar non-premixed counter-flow flames are initially explored. Then, the whole three-dimensional fluid dynamic problem is investigated by setting up a numerical experiment: it consists of a Direct Numerical Simulation, based on accurate transport, chemical, and numerical models. The flow topology of the specific reacting jet in crossflow configuration is described in terms of its main turbulent structures, like shear layers, ring, and horse-shoe vortices, as well as of its leeward recirculation region anchoring the flame. The reacting region is characterized by providing instantaneous spatial distributions of temperature, heat release, and some transported chemical species, including NO, and calculating the Flame Index to identify non-premixed and premixed combustion local conditions. The latter is quantified by looking at the distribution of the volume fraction associated with a certain Flame Index versus the Flame Index and at the distribution of the average values of both the Heat Release Rate and NO versus the Flame Index and the mixture fraction.