bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of 2-Amino-N′-aroyl(het)arylhydrazides, DNA Photocleavage, Molecular Docking and Cytotoxicity Studies against Melanoma CarB Cell Lines
Authors: Mitrakas Achilleas , Stathopoulou Maria-Eleni K. , Mikra Chrysoula , Konstantinou Chrystalla , Rizos Stergios , Malichetoudi Stella , Koumbis Alexandros E. , Koffa Maria , Fylaktakidou Konstantina C.
Published: January 2024

Diacylhydrazine bridged anthranilic acids with aryl and heteroaryl domains have been synthesized as the open flexible scaffold of arylamide quinazolinones in order to investigate flexibility versus rigidity towards DNA photocleavage and sensitivity. Most of the compounds have been synthesized via the in situ formation of their anthraniloyl chloride and subsequent reaction with the desired hydrazide and were obtained as precipitates, in moderate yields. All compounds showed high UV-A light absorption and are eligible for DNA photocleavage studies under this “harmless” irradiation. Despite their reduced UV-B light absorption, a first screening indicated the necessity of a halogen at the p-position in relation to the amine group and the lack of an electron-withdrawing group on the aryl group. These characteristics, in general, remained under UV-A light, rendering these compounds as a novel class of UV-A-triggered DNA photocleavers. The best photocleaver, the compound 9, was active at concentrations as low as 2 μΜ. The 5-Nitro-anthranilic derivatives were inactive, giving the opposite results to their related rigid quinazolinones. Molecular docking studies with DNA showed possible interaction sites, whereas cytotoxicity experiments indicated the iodo derivative 17 as a potent cytotoxic agent and the compound 9 as a slight phototoxic compound.
Chemical Constituents and Bioactivities of the Plant-Derived Fungus Aspergillus fumigatus
Authors: Sang Zihuan , Zhang Yanjiang , Qiu Kaidi , Zheng Yuting , Chen Chen , Xu Li , Lai Jiaying , Zou Zhenxing , Tan Haibo
Published: January 2024

A new bergamotane sesquiterpenoid, named xylariterpenoid H (1), along with fourteen known compounds (2–15), were isolated from the crude extract of Aspergillus fumigatus, an endophytic fungus isolated from Delphinium grandiflorum L. Their structures were elucidated mainly by extensive analyses of NMR and MS spectroscopic data. In addition, the screening results of antibacterial and cytotoxic activities of compounds 1–15 showed that compound 4 displayed antibacterial activities against Staphylococcus aureus and MRSA (methicillin-resistant S. aureus) with an MIC value of 3.12 µg/mL.
Thermal Conduction in Hybrid Nanofluids and Aggregates
Authors: Skouras Eugene D. , Karagiannakis Nikolaos P. , Burganos Vasilis N.
Published: January 2024

Hybrid nanofluids contain more than one type of nanoparticle and have shown improved thermofluidic properties compared to more conventional ones that contain a single nanocomponent. Such hybrid systems have been introduced to improve further the thermal and mass transport properties of nanoparticulate systems that affect a multitude of applications. The impact of a second particle type on the effective thermal conductivity of nanofluids is investigated here using the reconstruction of particle configurations and prediction of thermal efficiency with meshless methods, placing emphasis on the role of particle aggregation. An algorithm to obtain particle clusters of the core–shell type is presented as an alternative to random mixing. The method offers rapid, controlled reconstruction of clustered systems with tailored properties, such as the fractal dimension, the average number of particles per aggregate, and the distribution of distinct particle types within the aggregates. The nanoparticle dispersion conditions are found to have a major impact on the thermal properties of hybrid nanofluids. Specifically, the spatial distribution of the two particle types within the aggregates and the shape of the aggregates, as described by their fractal dimension, are shown to affect strongly the conductivity of the nanofluid even at low volume fractions. Cluster configurations made up of a high-conducting core and a low-conducting shell were found to be advantageous for conduction. Low fractal dimension aggregates favored the creation of long continuous pathways across the nanofluid and increased conductivity.
The Impact of ZIF-8 Particle Size Control on Low-Humidity Sensor Performance
Authors: Kim Sang Jun , Lee Jaemin , Bae Jong-Seong , Lee Jung Woo
Published: January 2024

An accurate humidity measurement is essential in various industries, including product stability, pharmaceutical and food preservation, environmental control, and precise humidity management in experiments and industrial processes. Crafting effective humidity sensors through precise material selection is crucial for detecting minute humidity levels across various fields, ultimately enhancing productivity and maintaining product quality. Metal–organic frameworks (MOFs), particularly zeolitic imidazolate frameworks (ZIFs), exhibit remarkable properties and offer a wide range of applications in catalysis, sensing, and gas storage due to their structural stability, which resembles zeolites. The previous research on MOF-based humidity sensors have primarily used electrical resistance-based methods. Recently, however, interest has shifted to capacitive-based sensors using MOFs due to the need for humidity sensors at low humidity and the resulting high sensitivity. Nevertheless, further studies are required to optimize particle structure and size. This study analyzes ZIF-8, a stable MOF synthesized in varying particle sizes, to evaluate its performance as a humidity sensor. The structural, chemical, and sensing properties of synthesized ZIF-8 particles ranging from 50 to 200 nanometers were examined through electron microscopy, spectroscopic, and electrochemical analyses. The fabricated copper electrodes combined with these particles demonstrated stable and linear humidity sensing capabilities within the range of 3% to 30% relative humidity (RH).
Correction: Ammar et al. Protective Effects of Naringenin from Citrus sinensis (var. Valencia) Peels against CCl4-Induced Hepatic and Renal Injuries in Rats Assessed by Metabolomics, Histological and Biochemical Analyses. Nutrients 2022, 14, 841
Authors: Ammar Naglaa M. , Hassan Heba A. , Abdallah Heba M. I. , Afifi Sherif M. , Elgamal Abdelbaset M. , Farrag Abdel Razik H. , El-Gendy Abd El-Nasser G. , Farag Mohamed A. , Elshamy Abdelsamed I.
Published: January 2024

In the original publication [...]
Diabetes-Specific Complete Smoothie Formulas Improve Postprandial Glycemic Response in Obese Type 2 Diabetic Individuals: A Randomized Crossover Trial
Authors: Mongkolsucharitkul Pichanun , Pinsawas Bonggochpass , Surawit Apinya , Pongkunakorn Tanyaporn , Manosan Thamonwan , Ophakas Suphawan , Suta Sophida , Pumeiam Sureeporn , Mayurasakorn Korapat
Published: January 2024

This study aimed to compare newly developed diabetes-specific complete smoothie formulas with a standard diabetes-specific nutritional formula (DSNF) regarding their effects on glucose homeostasis, insulin levels, and lipid metabolism in obese type 2 diabetes (T2DM) patients. We conducted a randomized, double-blind, crossover study with 41 obese T2DM participants to compare two developed diabetes-specific complete smoothie formulas, a soy-based regular smoothie (SM) and a smoothie with modified carbohydrate content (SMMC), with the standard DSNF, Glucerna. Glycemic and insulin responses were assessed after the participants randomly consumed 300 kilocalories of each formulation on three separate days with a 7-day gap between. Postprandial effects on glycemic control, insulin levels, and lipid metabolism were measured. SMMC resulted in a significantly lower glucose area under the curve (AUC0–240) compared to Glucerna and SM (p < 0.05 for both). Insulin AUC0–240 after SMMC was significantly lower than that after SM and Glucerna (p < 0.05). During the diets, the suppression of NEFA was more augmented on SM, resulting in a less total AUC0–240 of NEFA compared to the SMMC diet (p < 0.05). C-peptide AUC0–240 after SMMC was significantly lower than that after Glucerna (p < 0.001). Conversely, glucagon AUC0–240 after SMMC was significantly higher than that after SM and Glucerna (p < 0.05). These results highlight SMMC as the better insulin-sensitive formula, potentially achieved through increased insulin secretion or a direct reduction in glucose absorption. The unique composition of carbohydrates, amino acids, and fats from natural ingredients in the smoothies may contribute to these positive effects, making them promising functional foods for managing diabetes and obesity.
Berry Consumption in Relation to Allostatic Load in US Adults: The National Health and Nutrition Examination Survey, 2003–2010
Authors: Zhang Li , Muscat Joshua E. , Chinchilli Vernon M. , Kris-Etherton Penny M. , Al-Shaar Laila , Richie John P.
Published: January 2024

Introduction: Berries are a rich source of antioxidant polyphenols and other nutrients that are associated with good health. Allostatic load (AL) is an aggregate measure of chronic stress-induced physiological dysregulations across cardiovascular, metabolic, autonomic, and immune systems; the extent of these dysregulations, collectively or in each system, can be characterized by a composite score or a domain score assessed by integrated biomarkers. It was hypothesized that the anti-inflammatory and other effects of berries lower AL. The association was determined between berry consumption and AL composite and domain scores in the 2003–2010 National Health and Nutrition Examination Survey (NHANES). Methods: Berry intake was measured using two 24 h dietary recalls collected from US adults in the 2003–2010 NHANES (n = 7684). The association with AL and its specific domains was examined using population weight-adjusted multivariable linear regression. Results: The mean AL composite scores for consumers of any berries (11.9), strawberries (11.6), and blueberries (11.6), respectively, were significantly lower than nonconsumers (12.3), after fully adjusting for sociodemographic, lifestyle, and dietary confounders. A significant dose-response relationship was determined between greater consumption of total berries, strawberries, and blueberries and lower mean AL composite scores (p-trend < 0.05, for all). Consistently, mean cardiovascular and metabolic domain scores remained significantly lower in the consumers of total berries (mean cardiovascular domain score: 4.73 versus 4.97 for nonconsumers; mean metabolic domain score: 2.97 versus 3.1), strawberries (4.73 versus 4.95; 2.99 versus 3.1), and blueberries (4.6 versus 4.95; 2.92 versus 3.11). Berry consumers also had significantly lower mean AL immune scores (1.52 versus 1.56) and lower mean AL autonomic scores (2.49 versus 2.57) than nonconsumers (initial sample: n = 15,620). Conclusions: The current study indicates that consumption of berries lowers the AL composite scores and potentially reduces stress-related disease risks in the US adult population.
The Anti-Inflammatory and Antioxidant Properties of Acebuche Oil Exert a Retinoprotective Effect in a Murine Model of High-Tension Glaucoma
Authors: Lucchesi Martina , Marracci Silvia , Amato Rosario , Lapi Dominga , Santana-Garrido Álvaro , Espinosa-Martín Pablo , Vázquez Carmen María , Mate Alfonso , Dal Monte Massimo
Published: January 2024

Glaucoma is characterized by cupping of the optic disc, apoptotic degeneration of retinal ganglion cells (RGCs) and their axons, and thinning of the retinal nerve fiber layer, with patchy loss of vision. Elevated intraocular pressure (IOP) is a major risk factor for hypertensive glaucoma and the only modifiable one. There is a need to find novel compounds that counteract other risk factors contributing to RGC degeneration. The oil derived from the wild olive tree (Olea europaea var. sylvestris), also called Acebuche (ACE), shows powerful anti-inflammatory, antioxidant and retinoprotective effects. We evaluated whether ACE oil could counteract glaucoma-related detrimental effects. To this aim, we fed mice either a regular or an ACE oil-enriched diet and then induced IOP elevation through intraocular injection of methylcellulose. An ACE oil-enriched diet suppressed glaucoma-dependent retinal glia reactivity and inflammation. The redox status of the glaucomatous retinas was restored to a control-like situation, and ischemia was alleviated by an ACE oil-enriched diet. Notably, retinal apoptosis was suppressed in the glaucomatous animals fed ACE oil. Furthermore, as shown by electroretinogram analyses, RGC electrophysiological functions were almost completely preserved by the ACE oil-enriched diet. These ameliorative effects were IOP-independent and might depend on ACE oil’s peculiar composition. Although additional studies are needed, nutritional supplementation with ACE oil might represent an adjuvant in the management of glaucoma.
Exerkines, Nutrition, and Systemic Metabolism
Authors: Watkins Bruce A. , Smith Brenda J. , Volpe Stella Lucia , Shen Chwan-Li
Published: January 2024

The cornerstones of good health are exercise, proper food, and sound nutrition. Physical exercise should be a lifelong routine, supported by proper food selections to satisfy nutrient requirements based on energy needs, energy management, and variety to achieve optimal metabolism and physiology. The human body is sustained by intermediary and systemic metabolism integrating the physiologic processes for cells, tissues, organs, and systems. Recently, interest in specific metabolites, growth factors, cytokines, and hormones called exerkines has emerged to explain cooperation between nutrient supply organs and the brain during exercise. Exerkines consist of different compounds described as signaling moiety released during and after exercise. Examples of exerkines include oxylipin 12, 13 diHOME, lipid hormone adiponectin, growth factor BDNF, metabolite lactate, reactive oxygen species (ROS), including products of fatty acid oxidation, and cytokines such as interleukin-6. At this point, it is believed that exerkines are immediate, fast, and long-lasting factors resulting from exercise to support body energy needs with an emphasis on the brain. Although exerkines that are directly a product of macronutrient metabolism such as lactate, and result from catabolism is not surprising. Furthermore, other metabolites of macronutrient metabolism seem to be candidate exerkines. The exerkines originate from muscle, adipose, and liver and support brain metabolism, energy, and physiology. The purpose of this review is to integrate the actions of exerkines with respect to metabolism that occurs during exercise and propose other participating factors of exercise and brain physiology. The role of diet and macronutrients that influence metabolism and, consequently, the impact of exercise will be discussed. This review will also describe the evidence for PUFA, their metabolic and physiologic derivatives endocannabinoids, and oxylipins that validate them being exerkines. The intent is to present additional insights to better understand exerkines with respect to systemic metabolism.
Simple Estimate of the Impact of M2 and Strehl Ratio on the Effective Focusable Spot Size
Authors: Arba-Mosquera Samuel , Naubereit Pascal , Sobutas Simas
Published: January 2024

A simple method (first-order approximation) to determine the impact of M2 and the Strehl Ratio on the effective focusable spot size avoiding complex propagations of the beam wavefront is proposed. The model is based upon previous models and the definition of M2 and the Strehl Ratio in a simple manner. This work provides qualitative and quantitative estimates for the interplay of M2 and the Strehl Ratio on the effectively focusable spot size.
PARP1 as an Epigenetic Modulator: Implications for the Regulation of Host-Viral Dynamics
Authors: Sobotka Asher A. , Tempera Italo
Published: January 2024

The principal understanding of the Poly(ADP-ribose) polymerase (PARP) regulation of genomes has been focused on its role in DNA repair; however, in the past few years, an additional role for PARPs and PARylation has emerged in regulating viral-host interactions. In particular, in the context of DNA virus infection, PARP1-mediated mechanisms of gene regulations, such as the involvement with cellular protein complexes responsible for the folding of the genome into the nucleus, the formation of chromatin loops connecting distant regulatory genomic regions, and other methods of transcriptional regulation, provide additional ways through which PARPs can modulate the function of both the host and the viral genomes during viral infection. In addition, potential viral amplification of the activity of PARPs on the host genome can contribute to the pathogenic effect of viral infection, such as viral-driven oncogenesis, opening the possibility that PARP inhibition may represent a potential therapeutic approach to target viral infection. This review will focus on the role of PARPs, particularly PARP1, in regulating the infection of DNA viruses.
Enhancing Ocular Surface in Dry Eye Disease Patients: A Clinical Evaluation of a Topical Formulation Containing Sesquiterpene Lactone Helenalin
Authors: Ng Dalia , Altamirano-Vallejo Juan Carlos , Navarro-Partida Jose , Sanchez-Aguilar Oscar Eduardo , Inzunza Andres , Valdez-Garcia Jorge Eugenio , Gonzalez-de-la-Rosa Alejandro , Bustamante-Arias Andres , Armendariz-Borunda Juan , Santos Arturo
Published: January 2024

The aim of this work was to assess the tolerability, safety, and efficacy of an ophthalmic topical formulation containing helenalin from Arnica montana and hyaluronic acid 0.4% (HA) in patients with mild-to-moderate Dry Eye Disease (DED) exhibiting positive Matrix Metalloproteinase 9 (MMP-9) test results. Tolerability and safety were evaluated in 24 healthy subjects. Participants were instructed to apply one drop of the formulation three times a day in the study eye, for 2 weeks, followed by a clinical follow-up of 21 days. Efficacy was studied in 48 DED patients randomized into Study (Group 1/receiving the studied formulation) or Control (Group 2/Receiving HA 0.4% eye lubricant) groups for 1 month. Assessments included an MMP-9 positivity test, conjunctival impression cytology (CIC), Ocular Surface Disease Index (OSDI), non-invasive film tear breakup time (NIBUT), non-invasive average breakup time (NIAvg-BUT), ocular surface staining, Schirmer’s test, and meibomiography. A crossover design with an additional 1-month follow-up was applied to both groups. Healthy subjects receiving the studied formulation exhibited good tolerability and no adverse events. Regarding the efficacy study, Group 1 exhibited a statistically significant reduction in the MMP-9 positivity rate compared to Group 2 (p < 0.001). Both Group 1 and Group 2 exhibited substantial improvements in OSDI and NIBUT scores (p < 0.001). However, Group 1 demonstrated a significant improvement in NI-Avg-BUT and Schirmer’s test scores (p < 0.001), whereas Group 2 did not (p > 0.05). Finally, after the crossover, the proportion of MMP-9-positive subjects in Group 1 increased from 25% to 91.6%, while Group 2 showed a significant decrease from 87.5% to 20.8%. Overall, the topical formulation containing sesquiterpene helenalin from Arnica montana and hyaluronic acid was well tolerated and exhibited a favorable safety profile. Our formulation reduces DED symptomatology and modulates the ocular surface inflammatory process; this is evidenced by the enhancement of CIC, the improvement of DED-related tear film status, and the reduction of the MMP-9 positivity rate.
Nanopore Direct RNA Sequencing Reveals the Short-Term Salt Stress Response in Maize Roots
Authors: He Shidong , Wang Hui , Lv Minghao , Li Shun , Song Junhui , Wang Rongxin , Jiang Shaolong , Jiang Lijun , Zhang Shuxin , Li Xiang
Published: January 2024

Transcriptome analysis, relying on the cutting-edge sequencing of cDNA libraries, has become increasingly prevalent within functional genome studies. However, the dependence on cDNA in most RNA sequencing technologies restricts their ability to detect RNA base modifications. To address this limitation, the latest Oxford Nanopore Direct RNA Sequencing (ONT DRS) technology was employed to investigate the transcriptome of maize seedling roots under salt stress. This approach aimed to unveil both the RNA transcriptional profiles and alterations in base modifications. The analysis of the differential expression revealed a total of 1398 genes and 2223 transcripts that exhibited significant variation within the maize root system following brief exposure to salt stress. Enrichment analyses, such as the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway assessments, highlighted the predominant involvement of these differentially expressed genes (DEGs) in regulating ion homeostasis, nitrogen metabolism, amino acid metabolism, and the phytohormone signaling pathways. The protein–protein interaction (PPI) analysis showed the participation of various proteins related to glycolytic metabolism, nitrogen metabolism, amino acid metabolism, abscisic acid signaling, and the jasmonate signaling pathways. It was through this intricate molecular network that these proteins collaborated to safeguard root cells against salt-induced damage. Moreover, under salt stress conditions, the occurrence of variable shear events (AS) in RNA modifications diminished, the average length of poly(A) tails underwent a slight decrease, and the number of genes at the majority of the variable polyadenylation (APA) sites decreased. Additionally, the levels of N5-methylcytosine (m5C) and N6-methyladenosine (m6A) showed a reduction. These results provide insights into the mechanisms of early salt tolerance in maize.
Psammophytes Alyssum desertorum Stapf and Secale sylvestre Host Are Sensitive to Soil Flooding
Authors: Kordyum Elizabeth , Akimov Yuri , Polishchuk Oleksandr , Panas Ihor , Stepanov Sergiy , Kozeko Liudmyla
Published: January 2024

While morphological and functional traits enable hydrophytes to survive under waterlogging and partial or complete submergence, the data on responses of psammophytes—sand plants—to flooding are very limited. We analyzed the effect of 5- and 10-day soil flooding on the photosynthetic apparatus and the synthesis of alcohol dehydrogenase (ADH), heat shock proteins 70 (HSP70), and ethylene in seedlings of psammophytes Alyssum desertorum and Secale sylvestre using electron microscopy, chlorophyll a fluorescence induction, and biochemical methods. It was found that seedlings growing under soil flooding differed from those growing in stationary conditions with such traits as chloroplast ultrastructure, pigment content, chlorophyll fluorescence induction, and the dynamics of ADH, HSP, and ethylene synthesis. Although flooding caused no apparent damage to the photosynthetic apparatus in all the variants, a significant decrease in total photosynthesis efficiency was observed in both studied plants, as indicated by decreased values of φR0 and PIABS,total. More noticeable upregulation of ADH in S. sylvestre, as well as increasing HSP70 level and more intensive ethylene emission in A. desertorum, indicate species-specific differences in these traits in response to short-term soil flooding. Meanwhile, the absence of systemic anaerobic metabolic adaptation to prolonged hypoxia causes plant death.
Bidirectional Comparisons Revealed Functional Patterns in Interaction between Salmonella enterica and Plants
Authors: Han Min , Zarkani Azhar A. , Duan Yongming , Grimm Maja , Trotereau Jérôme , Virlogeux-Payant Isabelle , Schikora Adam
Published: January 2024

Plants may harbor the human pathogen Salmonella enterica. Interactions between S. enterica and different plant species have been studied in individual reports. However, disparities arising from the distinct experimental conditions may render a meaningful comparison very difficult. This study explored interaction patterns between different S. enterica strains including serovars Typhimurium 14028s and LT2 and serovar Senftenberg, and different plants (Arabidopsis, lettuce, and tomato) in one approach. Better persistence of S. enterica serovar Typhimurium strains was observed in all tested plants, whereas the resulting symptoms varied depending on plant species. Genes encoding pathogenesis-related proteins were upregulated in plants inoculated with Salmonella. Furthermore, transcriptome of tomato indicated dynamic responses to Salmonella, with strong and specific responses already 24 h after inoculation. By comparing with publicly accessible Arabidopsis and lettuce transcriptome results generated in a similar manner, constants and variables were displayed. Plants responded to Salmonella with metabolic and physiological adjustments, albeit with variability in reprogrammed orthologues. At the same time, Salmonella adapted to plant leaf-mimicking media with changes in biosynthesis of cellular components and adjusted metabolism. This study provides insights into the Salmonella-plant interaction, allowing for a direct comparison of responses and adaptations in both organisms.
Heat Tolerance of Gammarus fossarum (Crustacea, Amphipoda) Is Influenced by the Level of Stress Associated with Reproduction and the Water Quality of Their Habitat
Authors: Peschke Katharina , Sawallich Lilith , Köhler Heinz-R. , Triebskorn Rita
Published: January 2024

To elucidate how rising temperatures influence native amphipods, and how the expansion of wastewater treatment plants (WWTPs) with a fourth purification stage can alter temperature-related effects, studies were conducted in anthropogenically influenced rivers in Southwest Germany. Gammarids were sampled up- and downstream of two WWTPs, and exposed to elevated temperatures in the laboratory. Gammarids separated from precopula pairs were more sensitive to exposure-related stress and to a temperature increase than animals that were not in the reproductive phase. Furthermore, females were significantly more sensitive than males. Adult gammarids sampled individually at the WWTP with three purification stages showed a similar tolerance to elevated temperature at the up- and downstream site. In contrast, mortality following heat stress was substantially lower in animals sampled downstream of the WWTP with four treatment stages than in those sampled at the upstream site. We assume that the increased sensitivity of artificially separated precopula pairings reflect the situation under high hydraulic stress after heavy rainfall. Our results further illustrate the importance of WWTP upgrades in the context of climate change: gammarids sampled downstream the upgraded fourth-stage WWTP were likely exposed to lower levels of micropollutants, and thus may have allocated energy from detoxification to heat stress responses.
Synthesis and Characteristic Valuation of a Thermoplastic Polyurethane Electrode Binder for In-Mold Coating
Authors: Hong Suk-Min , Kwon Hyuck-Jin , Sun Jung-Min , Lee Chil Won
Published: January 2024

A polyurethane series (PHEI-PU) was prepared via a one-shot bulk polymerization method using hexamethylene diisocyanate (HDI), polycarbonate diol (PCD), and isosorbide derivatives (ISBD) as chain extenders. The mechanical properties were evaluated using a universal testing machine (UTM), and the thermal properties were evaluated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The PHEI-PU series exhibited excellent mechanical properties with an average tensile strength of 44.71 MPa and an elongation at break of 190%. To verify the applicability of different proportions of PU as an electrode binder, PU and Ag flakes were mixed (30/70 wt%) and coated on PCT substrates, the electrodes were evaluated by four-point probe before and after 50% elongation, and the dispersion was evaluated by scanning electron microscopy (SEM). The electrical resistance change rate of PHEI-PU series was less than 20%, and a coating layer with well-dispersed silver flakes was confirmed even after stretching. Therefore, it exhibited excellent physical properties, heat resistance, and electrical resistance change rate, confirming its applicability as an electrode binder for in-mold coating.
Cost-Effective Groundwater Potential Mapping by Integrating Multiple Remote Sensing Data and the Index–Overlay Method
Authors: Nainggolan Lamtupa , Ni Chuen-Fa , Darmawan Yahya , Lo Wei-Cheng , Lee I-Hsian , Lin Chi-Ping , Hiep Nguyen Hoang
Published: January 2024

The Choushui River groundwater basin (CRGB) in Yunlin County, Taiwan, is a significant groundwater source for the western part of the region. However, increasing groundwater demand and human activities have triggered a potential crisis due to overexploitation. Therefore, groundwater potential zone (GWPZ) maps are crucial for mapping groundwater resources and water resource management. This study employs the normalized index–overlay method and fuzzy extended analytical hierarchy process (FE-AHP) to map GWPZs cost-effectively. The methodology objectively incorporates weightings from various thematic layers by normalizing and correlating parameters with observed groundwater availability (GA). Site-specific observations, including aquifer thickness, depth to the groundwater level, and porosity, inform GA calculations. Seven comprehensive layers derived from remote sensing (RS) data are processed to obtain weightings and ratings for the groundwater potential index (GWPI) in the CRGB. Selected parameters are categorized into hydrological processes, human interventions, geological, and surface profiles. Hydrological processes include precipitation, modified normalized difference water index (MNDWI), and drainage density. Human interventions consist of the enhanced vegetation index (EVI) and normalized difference building index (NDBI). Surface profiles encompass the terrain ruggedness index (TRI) and slope, enhancing the study’s multi-criteria approach. The observed GA validates the GWPZ accuracy, classifying zones into five categories. According to the GWPI of FE-AHP, about 59.56% of the CRGB area can be categorized as “moderate” to “very good” potential groundwater recharge zones. Pearson’s correlation coefficient between GWPI and GA, based on FE-AHP, outperforms the conventional AHP. This RS-based approach efficiently evaluates GA in aquifers with limited wells, highlighting crucial zones in CRGB’s proximal-fan and southeastern mid-fan for informed groundwater management strategies.
Nearshore Bathymetry from ICESat-2 LiDAR and Sentinel-2 Imagery Datasets Using Physics-Informed CNN
Authors: Xie Congshuang , Chen Peng , Zhang Siqi , Huang Haiqing
Published: January 2024

The recently developed Ice, Cloud, and Land Elevation Satellite 2 (ICESat-2), furnished with the Advanced Terrain Laser Altimeter System (ATLAS), delivers considerable benefits in providing accurate bathymetric data across extensive geographical regions. By integrating active lidar-derived reference seawater depth data with passive optical remote sensing imagery, efficient bathymetry mapping is facilitated. In recent times, machine learning models are frequently used to define the nonlinear connection between remote sensing spectral data and water depths, which consequently results in the creation of bathymetric maps. A salient model among these is the convolutional neural network (CNN), which effectively integrates contextual information concerning bathymetric points. However, current CNN models and other machine learning approaches mainly concentrate on recognizing mathematical relationships within the data to determine a water depth function and remote sensing spectral data, while oftentimes disregarding the physical light propagation process in seawater before reaching the seafloor. This study presents a physics-informed CNN (PI-CNN) model which incorporates radiative transfer-based data into the CNN structure. By including the shallow water double-band radiative transfer physical term (swdrtt), this model enhances seawater spectral features and also considers the context surroundings of bathymetric pixels. The effectiveness and reliability of our proposed PI-CNN model are verified using in situ data from St. Croix and St. Thomas, validating its correctness in generating bathymetric maps with a broad experimental R2 accuracy exceeding 95% and remaining errors below 1.6 m. Preliminary results suggest that our PI-CNN model surpasses conventional methodologies.
Comparison Study of Earth Observation Characteristics between Moon-Based Platform and L1 Point of Earth-Moon System
Authors: Dong Runbo , Guo Huadong , Liu Guang
Published: January 2024

The unceasing quest for a profound comprehension of the Earth system propels the continuous evolution of novel methods for Earth observation. Of these, the Lagrange points situated in the cislunar space proffer noteworthy prospects for space-based Earth observation. Although extant research predominantly centers on Moon-based Earth observation and the L1 point within the Sun-Earth system, the realm of cislunar space remains relatively unexplored. This paper scrutinizes the overarching characteristics of the L1 point within the Earth-Moon system concerning Earth observation. A pivotal enhancement is introduced through the incorporation of the halo orbit. This research comprehensively analyzes the relative motion between the halo orbiter and the Earth, achieved via orbit determination within a rotating coordinate system, followed by a transformation into the Earth coordinate system. Subsequently, numerical simulations employing ephemeris data unveil the observing geometry and Earth observation characteristics, encompassing the distribution of nadir points, viewing angles, and the spatiotemporal ground coverage. As a point of reference, we also present a case study involving a Moon-based platform. Our findings reveal that the motion of the halo orbit, perpendicular to the lunar orbital plane, results in a broader range of nadir point latitudes, which can extend beyond 42°N/S, contingent upon the orbit’s size. Additionally, it manifests a more intricate latitude variation, characterized by the bimodal peaks of the proposed temporal complexity curve. The viewing angles and the spatiotemporal ground coverage closely resemble those of Moon-based platforms, with a marginal enhancement in coverage frequency for polar regions. Consequently, it can be deduced that the Earth observation characteristics of the L1 point within the Earth-Moon system bear a close resemblance to those of Moon-based platforms. Nevertheless, considering the distinct advantages of Moon-based platforms, the lunar surface remains the paramount choice, boasting the highest potential for Earth observation within cislunar space. In summation, this study demonstrates the Earth observation characteristics of the L1 point within the Earth-Moon system, emphasizing the distinctions between this and Moon-based platforms.
Estimation of Non-Optically Active Water Quality Parameters in Zhejiang Province Based on Machine Learning
Authors: Gao Lingfang , Shangguan Yulin , Sun Zhong , Shen Qiaohui , Shi Zhou
Published: January 2024

Water parameter estimation based on remote sensing is one of the common water quality evaluation methods. However, it is difficult to describe the relationship between the reflectance and the concentration of non-optically active substances due to their weak optical characteristics, and machine learning has become a viable solution for this problem. Therefore, based on machine learning methods, this study estimated four non-optically active water quality parameters including the permanganate index (CODMn), dissolved oxygen (DO), total nitrogen (TN), and total phosphorus (TP). Specifically, four machine learning models including Support Vector Machine Regression (SVR), Random Forest (RF), Extreme Gradient Boosting (XGBoost), and K-Nearest Neighbor (KNN) were constructed for each parameter and their performances were assessed. The results showed that the optimal models of CODMn, DO, TN, and TP were RF (R2 = 0.52), SVR (R2 = 0.36), XGBoost (R2 = 0.45), and RF (R2 = 0.39), respectively. The seasonal 10 m water quality over the Zhejiang Province was measured using these optimal models based on Sentinel-2 images, and the spatiotemporal distribution was analyzed. The results indicated that the annual mean values of CODMn, DO, TN, and TP in 2022 were 2.3 mg/L, 6.6 mg/L, 1.85 mg/L, and 0.063 mg/L, respectively, and the water quality in the western Zhejiang region was better than that in the northeastern Zhejiang region. The seasonal variations in water quality and possible causes were further discussed with some regions as examples. It was found that DO would decrease and CODMn would increase in summer due to the higher temperature and other factors. The results of this study helped understand the water quality in Zhejiang Province and can also be applied to the integrated management of the water environment. The models constructed in this study can also provide references for related research.
Assessment Accuracy of Standard Point Positioning Enhanced by Observation and Position Domain Filtering Utilizing a Multi-Epoch Least-Squares Integration Method
Authors: Li Fangchao , Psimoulis Panos , Li Qi , Yang Jie , Gao Jingxiang , Kou Xiaomei , Niu Le , Meng Xiaolin
Published: January 2024

To enhance the positioning accuracy of standalone GNSS receivers in environments unable to provide precise ephemeris and clock offset, such as undeveloped forest areas that lack network communication and power supply, this study employed the Time Difference Carrier Phase (TDCP) technology to improve the positioning accuracy of Standard Point Positioning (SPP), where the Least-Squares (LS) and the extended Multi-Epoch Least Squares (MELS) method were applied in the position domain filtering for a single GNSS receiver and compare its performance with the existing observation domain filtering method. Firstly, the simulated data sets with various positioning accuracies were used to verify the effectiveness and convergence of the LS filtering methods. The results indicate that the LS filtering method produces a lower root mean square (RMS) error than the original strategy. Secondly, this study uses two kinematic GNSS data sets to evaluate the performance of the observation and position domain filtering, with an emphasis on the MELS method. The numerical experiment results show that the position domain LS filtering method outperforms the other two methods. The open environment experiments result shows that the positioning domain filtering method achieved positioning accuracies of 0.202 m, 0.843 m, and 2.036 m in the E, N, and U directions, respectively, with improvements of 68.0%, 21.6%, and 24.0%, compared to the original algorithm which achieved positioning accuracies of 0.631 m, 1.076 m, and 2.680 m. It also achieved improvements of 24.0%, 4.0%, and 18.3%, respectively, compared to the observation domain filtering method with positioning accuracies of 0.353 m, 0.886 m, and 2.526 m. The forest scenes experiments result shows that the positioning domain filtering method achieved positioning accuracies of 1.308 m, 1.375 m, and 2.133 m in the E, N, and U directions, respectively, with improvements of 42.4%, 36.2%, and 27.6%, compared to original algorithm which achieved positioning accuracies of 1.863 m, 1.873 m, and 2.722 m, and also achieved improvements of 27.0%, 19.4% and 10.6%, respectively, comparing to observation domain filtering method with positioning accuracies of 1.661 m, 1.642 m and 2.359 m. Moreover, the examination of the LS method results based on different epochs reveals that the filtering accuracy increases as more epochs are incorporated into the position domain integration and the enhancement value reaches a few millimeters.
A Frequency–Azimuth Spectrum Estimation Method for Uniform Linear Array Based on Deconvolution
Authors: Lu Daiqiang , Cai Zhiming , Guo Wei , Yao Zhixiang , Cao Huanzhi
Published: January 2024

The frequency–azimuth (FRAZ) spectrum is a critical characteristic in passive target detection and tracking, as it encapsulates information regarding the signal’s frequency and azimuth. However, due to the inherent limitations in the sonar array’s physical aperture and the analysis time of the system, the signal often suffers from undersampling in both spatial and temporal dimensions. This undersampling leads to energy leakage across the azimuth and frequency domains, adversely affecting the resolution of the FRAZ spectrum. Such a reduction in resolution hampers multitarget resolution and feature extraction. To address these challenges, this study introduces a deconvolution-based FRAZ spectrum estimation method tailored for uniform linear arrays. The proposed method initiates by decoupling the azimuth and frequency in the FRAZ spectrum, forming a two-dimensional point scattering function that possesses shift-invariance. Subsequent to this, the power spectrum and the two-dimensional point scattering function undergo deconvolution using the Richardson–Lucy (R–L) iterative algorithm. The final stage involves calculating the signal azimuths and frequencies based on the deconvolution results from the preceding step. Comparative analyses involving simulations and sea test results reveal that the proposed method achieves a narrower main lobe width and diminished background noise in contrast to traditional FRAZ spectrum estimation techniques. This improvement is instrumental in minimizing the target’s energy leakage in both the azimuth and frequency domains.
TreeDetector: Using Deep Learning for the Localization and Reconstruction of Urban Trees from High-Resolution Remote Sensing Images
Authors: Gong Haoyu , Sun Qian , Fang Chenrong , Sun Le , Su Ran
Published: January 2024

There have been considerable efforts in generating tree crown maps from satellite images. However, tree localization in urban environments using satellite imagery remains a challenging task. One of the difficulties in complex urban tree detection tasks lies in the segmentation of dense tree crowns. Currently, methods based on semantic segmentation algorithms have made significant progress. We propose to split the tree localization problem into two parts, dense clusters and single trees, and combine the target detection method with a procedural generation method based on planting rules for the complex urban tree detection task, which improves the accuracy of single tree detection. Specifically, we propose a two-stage urban tree localization pipeline that leverages deep learning and planting strategy algorithms along with region discrimination methods. This approach ensures the precise localization of individual trees while also facilitating distribution inference within dense tree canopies. Additionally, our method estimates the radius and height of trees, which provides significant advantages for three-dimensional reconstruction tasks from remote sensing images. We compare our results with other existing methods, achieving an 82.3% accuracy in individual tree localization. This method can be seamlessly integrated with the three-dimensional reconstruction of urban trees. We visualized the three-dimensional reconstruction of urban trees generated by this method, which demonstrates the diversity of tree heights and provides a more realistic solution for tree distribution generation.
Integrated Framework for Unsupervised Building Segmentation with Segment Anything Model-Based Pseudo-Labeling and Weakly Supervised Learning
Authors: Kim Jiyong , Kim Yongil
Published: January 2024

The Segment Anything Model (SAM) has had a profound impact on deep learning applications in remote sensing. SAM, which serves as a prompt-based foundation model for segmentation, exhibits a remarkable capability to “segment anything,” including building objects on satellite or airborne images. To facilitate building segmentation without inducing supplementary prompts or labels, we applied a sequential approach of generating pseudo-labels and incorporating an edge-driven model. We first segmented the entire scene by SAM and masked out unwanted objects to generate pseudo-labels. Subsequently, we employed an edge-driven model designed to enhance the pseudo-label by using edge information to reconstruct the imperfect building features. Our model simultaneously utilizes spectral features from SAM-oriented building pseudo-labels and edge features from resultant images from the Canny edge detector and, thus, when combined with conditional random fields (CRFs), shows capability to extract and learn building features from imperfect pseudo-labels. By integrating the SAM-based pseudo-label with our edge-driven model, we establish an unsupervised framework for building segmentation that operates without explicit labels. Our model excels in extracting buildings compared with other state-of-the-art unsupervised segmentation models and even outperforms supervised models when trained in a fully supervised manner. This achievement demonstrates the potential of our model to address the lack of datasets in various remote sensing domains for building segmentation.
Anti-Interference Bottom Detection Method of Multibeam Echosounders Based on Deep Learning Models
Authors: Meng Junxia , Yan Jun , Zhang Qinghe
Published: January 2024

Multibeam echosounders, as the most commonly used bathymetric equipment, have been widely applied in acquiring seabed topography and underwater sonar images. However, when interference occurs in the water column, traditional bottom detection methods may fail, resulting in discontinuities in the bathymetry and distortion in the sonar images. To solve this problem, we propose an anti-interference bottom detection method based on deep learning models. First, the variation differences of backscatter strengths at different incidence angles and the failure conditions of traditional methods were analyzed. Second, the details of our deep learning models are explained. And these models were trained using samples in the specular reflection, scatter reflection, and high-incidence angle regions, respectively. Third, the bottom detection procedures of the along-track and across-track water column data using the trained models are provided. In the experiments, multibeam data with strong interferences in the water column were selected. The bottom detection results of the along-track water column data at incidence angles of 0°, 35°, and 60° and the across-track ping data validated the effectiveness of our method. By comparison, our method acquired the correct bottom position when the traditional methods had inaccurate or even no detection results. Our method can be used to supplement existing methods and effectively improve bathymetry robustness under interference conditions.