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Search Results (1,834)

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17 pages, 1306 KiB  
Article
Rapid Salmonella Serovar Classification Using AI-Enabled Hyperspectral Microscopy with Enhanced Data Preprocessing and Multimodal Fusion
by MeiLi Papa, Siddhartha Bhattacharya, Bosoon Park and Jiyoon Yi
Foods 2025, 14(15), 2737; https://doi.org/10.3390/foods14152737 - 5 Aug 2025
Abstract
Salmonella serovar identification typically requires multiple enrichment steps using selective media, consuming considerable time and resources. This study presents a rapid, culture-independent method leveraging artificial intelligence (AI) to classify Salmonella serovars from rich hyperspectral microscopy data. Five serovars (Enteritidis, Infantis, Kentucky, Johannesburg, 4,[5],12:i:-) [...] Read more.
Salmonella serovar identification typically requires multiple enrichment steps using selective media, consuming considerable time and resources. This study presents a rapid, culture-independent method leveraging artificial intelligence (AI) to classify Salmonella serovars from rich hyperspectral microscopy data. Five serovars (Enteritidis, Infantis, Kentucky, Johannesburg, 4,[5],12:i:-) were analyzed from samples prepared using only sterilized de-ionized water. Hyperspectral data cubes were collected to generate single-cell spectra and RGB composite images representing the full microscopy field. Data analysis involved two parallel branches followed by multimodal fusion. The spectral branch compared manual feature selection with data-driven feature extraction via principal component analysis (PCA), followed by classification using conventional machine learning models (i.e., k-nearest neighbors, support vector machine, random forest, and multilayer perceptron). The image branch employed a convolutional neural network (CNN) to extract spatial features directly from images without predefined morphological descriptors. Using PCA-derived spectral features, the highest performing machine learning model achieved 81.1% accuracy, outperforming manual feature selection. CNN-based classification using image features alone yielded lower accuracy (57.3%) in this serovar-level discrimination. In contrast, a multimodal fusion model combining spectral and image features improved accuracy to 82.4% on the unseen test set while reducing overfitting on the train set. This study demonstrates that AI-enabled hyperspectral microscopy with multimodal fusion can streamline Salmonella serovar identification workflows. Full article
(This article belongs to the Special Issue Artificial Intelligence (AI) and Machine Learning for Foods)
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8 pages, 844 KiB  
Opinion
Flawed Metrics, Damaging Outcomes: A Rebuttal to the RI2 Integrity Index Targeting Top Indonesian Universities
by Muhammad Iqhrammullah, Derren D. C. H. Rampengan, Muhammad Fadhlal Maula and Ikhwan Amri
Publications 2025, 13(3), 36; https://doi.org/10.3390/publications13030036 - 4 Aug 2025
Viewed by 325
Abstract
The Research Integrity Risk Index (RI2), introduced as a tool to identify universities at risk of compromised research integrity, adopts an overly reductive methodology by combining retraction rates and delisted journal proportions into a single, equally weighted composite score. While its [...] Read more.
The Research Integrity Risk Index (RI2), introduced as a tool to identify universities at risk of compromised research integrity, adopts an overly reductive methodology by combining retraction rates and delisted journal proportions into a single, equally weighted composite score. While its stated aim is to promote accountability, this commentary critiques the RI2 index for its flawed assumptions, lack of empirical validation, and disproportionate penalization of institutions in low- and middle-income countries. We examine how RI2 misinterprets retractions, misuses delisting data, and fails to account for diverse academic publishing environments, particularly in Indonesia, where many high-performing universities are unfairly categorized as “high risk” or “red flag.” The index’s uncritical reliance on opaque delisting decisions, combined with its fixed equal-weighting formula, produces volatile and context-insensitive scores that do not accurately reflect the presence or severity of research misconduct. Moreover, RI2 has gained significant media attention and policy influence despite being based on an unreviewed preprint, with no transparent mechanism for institutional rebuttal or contextual adjustment. By comparing RI2 classifications with established benchmarks such as the Scimago Institution Rankings and drawing from lessons in global development metrics, we argue that RI2, although conceptually innovative, should remain an exploratory framework. It requires rigorous scientific validation before being adopted as a global standard. We also propose flexible weighting schemes, regional calibration, and transparent engagement processes to improve the fairness and reliability of institutional research integrity assessments. Full article
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34 pages, 4961 KiB  
Article
Study on Grinding Optimization of Cassiterite Polymetallic Sulfide Ore Based on Single-Factor Test Method
by Jinlin Yang, Pengyan Zhu, Xingjian Deng, Hengjun Li, Shaojian Ma and Dingzheng Wang
Minerals 2025, 15(8), 827; https://doi.org/10.3390/min15080827 - 3 Aug 2025
Viewed by 135
Abstract
Cassiterite polymetallic sulfide ore exhibits a complex mineral composition and significant variations in mineral properties, which frequently lead to issues such as the over-grinding of cassiterite and under-grinding of sulfide minerals during the grinding process. These issues consequently impair liberation performance in subsequent [...] Read more.
Cassiterite polymetallic sulfide ore exhibits a complex mineral composition and significant variations in mineral properties, which frequently lead to issues such as the over-grinding of cassiterite and under-grinding of sulfide minerals during the grinding process. These issues consequently impair liberation performance in subsequent beneficiation stages. Among these factors, the grinding media ratios stand as one of the critical factors influencing grinding efficiency. Based on these, the paper adopts the single-factor test method to systematically study the influence law of factors such as grinding time, mill rotational rate, and mill filling rate on the particle size composition of ore grinding products and the grinding technology efficiency under different media conditions; in addition, it is compared with the influence law of different conditions of media ratios on the grinding efficiency of ore. The results show that the optimal parameters of the grinding operation are obtained at the grinding time of 4 min, the mill rotational rate of 60%, and the filling rate of 35%. The grinding time and mill filling rate have a relatively more significant effect on the product particle size distribution, while the effect of the mill rotational rate is relatively less significant. When the parameters of grinding operations are optimal, the yield of qualified particle size and grinding technical efficiency are used as the evaluation indices, respectively. Overall, the order of the grinding effect of different media conditions was as follows: steel ball combination of Φ20 mm and Φ25 mm > steel balls of three single sizes > steel ball combination of Φ20 mm and Φ30 mm. The optimal grinding media ratios are Φ20 mm and Φ25 mm (the percentage of the Φ20 mm ball is 90%). The reasonable media ratios will effectively coordinate the optimal grinding effect between different media. The research results can provide the necessary basic data for the subsequent grinding optimization of cassiterite polymetallic sulfide ores. Full article
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14 pages, 2597 KiB  
Article
Chemical and Isotopic Investigation of Abiotic Oxidation of Lactate Substrate in the Presence of Varied Electron Acceptors and Under Circumneutral Anaerobic Conditions
by Tsigabu A. Gebrehiwet and R. V. Krishnamurthy
Water 2025, 17(15), 2308; https://doi.org/10.3390/w17152308 - 3 Aug 2025
Viewed by 231
Abstract
Abiotic processes have ramifications in wastewater treatment, in situ degradation of organic matter, and cycling of nutrients in wetland ecosystems. Experiments were conducted to investigate abiotic oxidation of organic compounds (lactate) as a function of electron acceptors (ferric citrate and hydrous ferric oxide [...] Read more.
Abiotic processes have ramifications in wastewater treatment, in situ degradation of organic matter, and cycling of nutrients in wetland ecosystems. Experiments were conducted to investigate abiotic oxidation of organic compounds (lactate) as a function of electron acceptors (ferric citrate and hydrous ferric oxide (HFO), media composition, and pH under anaerobic conditions, using sodium bicarbonate as the buffering agent. Dissolved inorganic carbon (DIC) was used as a proxy for the oxidation of substrates. HFO media generated more DIC compared to ferric citrate containing media. Light and pH had major roles in the oxidation of lactate in the presence of ferric iron. Under dark conditions in the presence or absence of Fe(III), the DIC produced was low in all pH conditions. Inhibition of DIC production was also observed upon photo exposure when Fe (III) was absent. Isotopically, the system showed initial mixing between the bicarbonate and the carbon dioxide produced from oxidation later being dominated by carbon isotope value of lactate used. These redox conditions align with previous studies suggesting cleavage of organic compounds by hydroxyl radicals. The slower redox processes observed here, compared to previous studies, could be due to the scavenging effect of chloride ion on the hydroxyl radical. Full article
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10 pages, 868 KiB  
Article
The Response of Cell Cultures to Nutrient- and Serum-Induced Changes in the Medium
by Marijana Leventić, Katarina Mišković Špoljarić, Karla Vojvodić, Nikolina Kovačević, Marko Obradović and Teuta Opačak-Bernardi
Sci 2025, 7(3), 105; https://doi.org/10.3390/sci7030105 - 2 Aug 2025
Viewed by 206
Abstract
Cell culture models are of central importance for the investigation of cellular metabolism, proliferation and stress responses. In this study, the effects of different concentrations of glucose (1 g/L vs. 4.5 g/L) and fetal bovine serum (FBS; 5%, 10%, 15%) on viability, mitochondrial [...] Read more.
Cell culture models are of central importance for the investigation of cellular metabolism, proliferation and stress responses. In this study, the effects of different concentrations of glucose (1 g/L vs. 4.5 g/L) and fetal bovine serum (FBS; 5%, 10%, 15%) on viability, mitochondrial function and autophagy are investigated in four human cell lines: MRC-5, HeLa, Caco-2 and SW-620. Cells were cultured in defined media for 72 h, and viability was assessed by LDH release, mitochondrial membrane potential using Rhodamine 123, ATP content by luminescence and autophagy activity by dual fluorescence staining. The results showed that HeLa and SW-620 cancer cells exhibited increased proliferation and mitochondrial activity under high glucose conditions, while low glucose media resulted in decreased ATP content and increased membrane permeability in HeLa cells. MRC-5 fibroblasts and Caco-2 cells showed greater resilience to nutrient stress, with minimal changes in LDH release and consistent proliferation. Autophagy was activated under all conditions, with a significant increase only in selected cell-medium combinations. These results highlight the importance of medium composition in influencing cellular bioenergetics and stress responses, which has implications for cancer research, metabolic disease modelling and the development of serum-free culture systems for regenerative medicine. Full article
(This article belongs to the Section Biology Research and Life Sciences)
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23 pages, 2657 KiB  
Article
Enrichment Cultures of Extreme Acidophiles with Biotechnological Potential
by Khussain Valiyev, Aliya Yskak, Elena Latyuk, Alena Artykova, Rakhimbayev Berik, Vadim Chashkov and Aleksandr Bulaev
Mining 2025, 5(3), 49; https://doi.org/10.3390/mining5030049 - 1 Aug 2025
Viewed by 101
Abstract
The purpose of this work was to obtain specialized enrichment cultures from an original extreme acidophilic consortium of extremely acidophilic microorganisms and to study their microbial community composition and biotechnological potential. At temperatures of 25, 35, 40 and 50 °C, distinct enrichments of [...] Read more.
The purpose of this work was to obtain specialized enrichment cultures from an original extreme acidophilic consortium of extremely acidophilic microorganisms and to study their microbial community composition and biotechnological potential. At temperatures of 25, 35, 40 and 50 °C, distinct enrichments of extremely acidophilic microorganisms used in the processes of bioleaching sulfide ores were obtained using nutrient media containing ferrous sulfate, elemental sulfur and a copper sulfide concentrate as nutrient inorganic substrates, with and without the addition of 0.02% yeast extract. The microbial community composition was studied using the sequencing of the V3–V4 hypervariable region of the 16S rRNA genes. The different growth conditions led to changes in the microbial composition and relative abundance of mesophilic and moderately thermophilic, strict autotrophic and mixotrophic microorganisms in members of the genera Acidithiobacillus, Sulfobacillus, Leptospirillum, Acidibacillus, Ferroplasma and Cuniculiplasma. The dynamics of the oxidation of ferrous iron, sulfur, and sulfide minerals (pyrite and chalcopyrite) by the enrichments was also studied in the temperature range of 25 to 50 °C. The study of enrichment cultures using the molecular biological method using the metabarcoding method of variable V3–24 V4 fragments of 16S rRNA genes showed that enrichment cultures obtained under different conditions differed in composition, which can be explained by differences in the physiological properties of the identified microorganisms. Regarding the dynamics of the oxidation of ferrous ions, sulfur, and sulfide minerals (pyrite and chalcopyrite), each enrichment culture was studied at a temperature range of 25 to 50 °C and indicated that all obtained enrichments were capable of oxidizing ferrous iron, sulfur and minerals at different rates. The obtained enrichment cultures may be used in further work to increase bioleaching by using the suitable inoculum for the temperature and process conditions. Full article
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14 pages, 6773 KiB  
Article
MoTiCo Conversion Coating on 7075 Aluminium Alloy Surface: Preparation, Corrosion Resistance Analysis, and Application in Outdoor Sports Equipment Trekking Poles
by Yiqun Wang, Feng Huang and Xuzheng Qian
Metals 2025, 15(8), 864; https://doi.org/10.3390/met15080864 (registering DOI) - 1 Aug 2025
Viewed by 149
Abstract
The problem of protecting 7075 Al alloy trekking poles from corrosion in complex outdoor environments was addressed using a composite conversion coating system. This system comprised Na2MoO4, NaF, CoSO4·7H2O, ethylenediaminetetraacetic acid-2Na, and H2(TiF [...] Read more.
The problem of protecting 7075 Al alloy trekking poles from corrosion in complex outdoor environments was addressed using a composite conversion coating system. This system comprised Na2MoO4, NaF, CoSO4·7H2O, ethylenediaminetetraacetic acid-2Na, and H2(TiF6). The influences of this system on the properties of the coating layer were systematically studied by adjusting the pH of the coating solution. The conversion temperature and pH were the pivotal parameters influencing the formation of the conversion coating. The pH substantially influenced the compactness of the coating layer, acting as a regulatory agent of the coating kinetics. When the conversion temperature and pH were set to 40 °C and 3.8, respectively, the prepared coating layer displayed optimal performance in terms of compactness and protective properties. Therefore, this parameter combination favours the synthesis of high-performance conversion coatings. Microscopy confirmed the formation of a continuous, dense composite oxide film structure under these conditions, effectively blocking erosion in corrosive media. Furthermore, the optimised process led to substantial enhancements in the environmental adaptabilities and service lives of the components of trekking poles, thus establishing a theoretical foundation and technical reference for use in the surface protection of outdoor equipment. Full article
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21 pages, 2582 KiB  
Article
Photolysis, Photocatalysis, and Sorption of Caffeine in Aqueous Media in the Presence of Chitosan Membrane and Chitosan/TiO2 Composite Membrane
by Juliana Prando, Ingrid Luíza Reinehr, Luiz Jardel Visioli, Alexandre Tadeu Paulino and Heveline Enzweiler
Processes 2025, 13(8), 2439; https://doi.org/10.3390/pr13082439 - 1 Aug 2025
Viewed by 265
Abstract
Sorption and advanced oxidative processes (AOPs) are potential strategies for the removal of organic compounds, such as caffeine, from aqueous media. Such strategies tend to be more promising when combined with biopolymeric membranes as sorbents and photocatalyst supports. Therefore, the aim of the [...] Read more.
Sorption and advanced oxidative processes (AOPs) are potential strategies for the removal of organic compounds, such as caffeine, from aqueous media. Such strategies tend to be more promising when combined with biopolymeric membranes as sorbents and photocatalyst supports. Therefore, the aim of the present study was to investigate sorption and AOP parameters in the performance of chitosan membranes and chitosan/TiO2 composite membranes in individual and hybrid systems involving the photolysis, photocatalysis, and sorption of caffeine. Caffeine degradation by photolysis was 19.51 ± 1.14, 28.61 ± 0.05, and 30.64 ± 6.32%, whereas caffeine degradation by photocatalysis with catalytic membrane was 18.33 ± 2.20, 20.83 ± 1.49, and 31.41 ± 3.08% at pH 6, 7, and 8, respectively. In contrast, photocatalysis with the dispersed catalyst achieved degradation of 93.56 ± 2.12, 36.42 ± 2.59, and 31.41 ± 1.07% at pH 6, 7, and 8, respectively. These results indicate that ions present in the buffer solutions affect the net electrical charge on the surface of the composite biomaterial with the change in pH variation, occupying active sorption sites in the structure of the biomaterial, which was characterized by Fourier transform infrared spectrometry, thermogravimetric analysis, differential scanning thermogravimetry, and X-ray diffraction. Thus, it is verified that in a combined process of caffeine removal under UV irradiation and use of chitosan/TiO2 composite membranes in phosphate-buffered medium, the photolysis mechanism is predominant, with little or no contribution from sorption, and that the TiO2 catalyst promotes a significant reduction in the percentage of pollutant in the medium only when used dispersed and at low pH. Full article
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16 pages, 950 KiB  
Article
Survey of Weed Flora Diversity as a Starting Point for the Development of a Weed Management Strategy for Medicinal Crops in Pančevo, Serbia
by Dragana Božić, Ana Dragumilo, Tatjana Marković, Urban Šilc, Svetlana Aćić, Teodora Tojić, Miloš Rajković and Sava Vrbničanin
Horticulturae 2025, 11(8), 882; https://doi.org/10.3390/horticulturae11080882 (registering DOI) - 31 Jul 2025
Viewed by 176
Abstract
Similarly to conventional field crops, weeds often pose significant problems in the cultivation of medicinal plants. To date, no comprehensive documentation exists regarding weed infestation levels in these crops in Serbia. The objective of this study was to provide a valuable foundation for [...] Read more.
Similarly to conventional field crops, weeds often pose significant problems in the cultivation of medicinal plants. To date, no comprehensive documentation exists regarding weed infestation levels in these crops in Serbia. The objective of this study was to provide a valuable foundation for developing effective, site-specific weed management strategies in medicinal crop production. Weeds in five medicinal crops (lemon balm, fennel, peppermint, ribwort plantain, German chamomile), were surveyed based on the agro-phytosociological method between 2019 and 2024, and across 59 plots. A total of 109 weed species were recorded, belonging to 29 families and 88 genera. Among them, 75 were annuals and 34 perennials, including 93 broadleaved species, 10 grasses, and one parasitic species. All surveyed plots were heavily infested with perennial weeds such as Elymus repens, Cirsium arvense, Convolvulus arvensis, Lepidium draba, Rumex crispus, Sorghum halepense, Taraxacum officinale, etc. Also, several annual species were found in high abundance and frequency, including Amaranthus retroflexus, Chenopodium album, Galium aparine, Lactuca serriola, Lamium amplexicaule, L. purpureum, Papaver rhoeas, Stellaria media, Veronica hederifolia, V. persica, etc. The most important ecological factors influencing the composition of weed vegetation in investigated medicinal crops were temperature and light for fennel and peppermint plots, soil reaction for lemon balm and ribwort plantain plots, and nutrient content for German chamomile plots. A perspective for exploitation of these results is the development of effective weed control programs tailored to this specific cropping system. Weed control strategies should consider such information, targeting the control of the most frequent, abundant, and dominant species existing in a crops or locality. Full article
(This article belongs to the Special Issue Conventional and Organic Weed Management in Horticultural Production)
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22 pages, 61181 KiB  
Article
Stepwise Building Damage Estimation Through Time-Scaled Multi-Sensor Integration: A Case Study of the 2024 Noto Peninsula Earthquake
by Satomi Kimijima, Chun Ping, Shono Fujita, Makoto Hanashima, Shingo Toride and Hitoshi Taguchi
Remote Sens. 2025, 17(15), 2638; https://doi.org/10.3390/rs17152638 - 30 Jul 2025
Viewed by 337
Abstract
Rapid and comprehensive assessment of building damage caused by earthquakes is essential for effective emergency response and rescue efforts in the immediate aftermath. Advanced technologies, including real-time simulations, remote sensing, and multi-sensor systems, can effectively enhance situational awareness and structural damage evaluations. However, [...] Read more.
Rapid and comprehensive assessment of building damage caused by earthquakes is essential for effective emergency response and rescue efforts in the immediate aftermath. Advanced technologies, including real-time simulations, remote sensing, and multi-sensor systems, can effectively enhance situational awareness and structural damage evaluations. However, most existing methods rely on isolated time snapshots, and few studies have systematically explored the continuous, time-scaled integration and update of building damage estimates from multiple data sources. This study proposes a stepwise framework that continuously updates time-scaled, single-damage estimation outputs using the best available multi-sensor data for estimating earthquake-induced building damage. We demonstrated the framework using the 2024 Noto Peninsula Earthquake as a case study and incorporated official damage reports from the Ishikawa Prefectural Government, real-time earthquake building damage estimation (REBDE) data, and satellite-based damage estimation data (ALOS-2-building damage estimation (BDE)). By integrating the REBDE and ALOS-2-BDE datasets, we created a composite damage estimation product (integrated-BDE). These datasets were statistically validated against official damage records. Our framework showed significant improvements in accuracy, as demonstrated by the mean absolute percentage error, when the datasets were integrated and updated over time: 177.2% for REBDE, 58.1% for ALOS-2-BDE, and 25.0% for integrated-BDE. Finally, for stepwise damage estimation, we proposed a methodological framework that incorporates social media content to further confirm the accuracy of damage assessments. Potential supplementary datasets, including data from Internet of Things-enabled home appliances, real-time traffic data, very-high-resolution optical imagery, and structural health monitoring systems, can also be integrated to improve accuracy. The proposed framework is expected to improve the timeliness and accuracy of building damage assessments, foster shared understanding of disaster impacts across stakeholders, and support more effective emergency response planning, resource allocation, and decision-making in the early stages of disaster management in the future, particularly when comprehensive official damage reports are unavailable. Full article
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23 pages, 1249 KiB  
Review
Guiding Microbial Crossroads: Syngas-Driven Valorisation of Anaerobic-Digestion Intermediates into Bio-Hydrogen and Volatile Fatty Acids
by Alvaro dos Santos Neto and Mohammad J. Taherzadeh
Bioengineering 2025, 12(8), 816; https://doi.org/10.3390/bioengineering12080816 - 29 Jul 2025
Viewed by 354
Abstract
Anaerobic digestion (AD) has long been valued for producing a biogas–digestate pair, yet its profitability is tightening. Next-generation AD biorefineries now position syngas both as a supplementary feedstock and as a springboard to capture high-value intermediates, hydrogen (H2) and volatile fatty [...] Read more.
Anaerobic digestion (AD) has long been valued for producing a biogas–digestate pair, yet its profitability is tightening. Next-generation AD biorefineries now position syngas both as a supplementary feedstock and as a springboard to capture high-value intermediates, hydrogen (H2) and volatile fatty acids (VFA). This review dissects how complex natural consortia “decide” between hydrogenogenesis and acetogenesis when CO, H2, and CO2 co-exist in the feedstocks, bridging molecular mechanisms with process-scale levers. The map of the bioenergetic contest between the biological water–gas shift reaction and Wood–Ljungdahl pathways is discussed, revealing how electron flow, thermodynamic thresholds, and enzyme inhibition dictate microbial “decision”. Kinetic evidence from pure and mixed cultures is integrated with practical operating factors (gas composition and pressure, pH–temperature spectrum, culture media composition, hydraulic retention time, and cell density), which can bias consortia toward the desired product. Full article
(This article belongs to the Special Issue Anaerobic Digestion Advances in Biomass and Waste Treatment)
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32 pages, 2851 KiB  
Article
Characterization of Tellurite Toxicity to Escherichia coli Under Aerobic and Anaerobic Conditions
by Roberto Luraschi, Claudia Muñoz-Villagrán, Fabián A. Cornejo, Benoit Pugin, Fernanda Contreras Tobar, Juan Marcelo Sandoval, Jaime Andrés Rivas-Pardo, Carlos Vera and Felipe Arenas
Int. J. Mol. Sci. 2025, 26(15), 7287; https://doi.org/10.3390/ijms26157287 - 28 Jul 2025
Viewed by 264
Abstract
Tellurite (TeO32−) is a highly soluble and toxic oxyanion that inhibits the growth of Escherichia coli at concentrations as low as ~1 µg/mL. This toxicity has been primarily attributed to the generation of reactive oxygen species (ROS) during its intracellular [...] Read more.
Tellurite (TeO32−) is a highly soluble and toxic oxyanion that inhibits the growth of Escherichia coli at concentrations as low as ~1 µg/mL. This toxicity has been primarily attributed to the generation of reactive oxygen species (ROS) during its intracellular reduction by thiol-containing molecules and NAD(P)H-dependent enzymes. However, under anaerobic conditions, E. coli exhibits significantly increased tellurite tolerance—up to 100-fold in minimal media—suggesting the involvement of additional, ROS-independent mechanisms. In this study, we combined chemical-genomic screening, untargeted metabolomics, and targeted biochemical assays to investigate the effects of tellurite under both aerobic and anaerobic conditions. Our findings reveal that tellurite perturbs amino acid and nucleotide metabolism, leading to intracellular imbalances that impair protein synthesis. Additionally, tellurite induces notable changes in membrane lipid composition, particularly in phosphatidylethanolamine derivatives, which may influence biophysical properties of the membrane, such as fluidity or curvature. This membrane remodeling could contribute to the increased resistance observed under anaerobic conditions, although direct evidence of altered membrane fluidity remains to be established. Overall, these results demonstrate that tellurite toxicity extends beyond oxidative stress, impacting central metabolic pathways and membrane-associated functions regardless of oxygen availability. Full article
(This article belongs to the Section Molecular Microbiology)
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26 pages, 4687 KiB  
Article
Geant4-Based Logging-While-Drilling Gamma Gas Detection for Quantitative Inversion of Downhole Gas Content
by Xingming Wang, Xiangyu Wang, Qiaozhu Wang, Yuanyuan Yang, Xiong Han, Zhipeng Xu and Luqing Li
Processes 2025, 13(8), 2392; https://doi.org/10.3390/pr13082392 - 28 Jul 2025
Viewed by 355
Abstract
Downhole kick is one of the most severe safety hazards in deep and ultra-deep well drilling operations. Traditional monitoring methods, which rely on surface flow rate and fluid level changes, are limited by their delayed response and insufficient sensitivity, making them inadequate for [...] Read more.
Downhole kick is one of the most severe safety hazards in deep and ultra-deep well drilling operations. Traditional monitoring methods, which rely on surface flow rate and fluid level changes, are limited by their delayed response and insufficient sensitivity, making them inadequate for early warning. This study proposes a real-time monitoring technique for gas content in drilling fluid based on the attenuation principle of Ba-133 γ-rays. By integrating laboratory static/dynamic experiments and Geant4-11.2 Monte Carlo simulations, the influence mechanism of gas–liquid two-phase media on γ-ray transmission characteristics is systematically elucidated. Firstly, through a comparative analysis of radioactive source parameters such as Am-241 and Cs-137, Ba-133 (main peak at 356 keV, half-life of 10.6 years) is identified as the optimal downhole nuclear measurement source based on a comparative analysis of penetration capability, detection efficiency, and regulatory compliance. Compared to alternative sources, Ba-133 provides an optimal energy range for detecting drilling fluid density variations, while also meeting exemption activity limits (1 × 106 Bq) for field deployment. Subsequently, an experimental setup with drilling fluids of varying densities (1.2–1.8 g/cm3) is constructed to quantify the inverse square attenuation relationship between source-to-detector distance and counting rate, and to acquire counting data over the full gas content range (0–100%). The Monte Carlo simulation results exhibit a mean relative error of 5.01% compared to the experimental data, validating the physical correctness of the model. On this basis, a nonlinear inversion model coupling a first-order density term with a cubic gas content term is proposed, achieving a mean absolute percentage error of 2.3% across the full range and R2 = 0.999. Geant4-based simulation validation demonstrates that this technique can achieve a measurement accuracy of ±2.5% for gas content within the range of 0–100% (at a 95% confidence interval). The anticipated field accuracy of ±5% is estimated by accounting for additional uncertainties due to temperature effects, vibration, and mud composition variations under downhole conditions, significantly outperforming current surface monitoring methods. This enables the high-frequency, high-precision early detection of kick events during the shut-in period. The present study provides both theoretical and technical support for the engineering application of nuclear measurement techniques in well control safety. Full article
(This article belongs to the Section Chemical Processes and Systems)
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20 pages, 10028 KiB  
Article
The Fabrication of Cu2O-u/g-C3N4 Heterojunction and Its Application in CO2 Photoreduction
by Jiawei Lu, Yupeng Zhang, Fengxu Xiao, Zhikai Liu, Youran Li, Guiyang Shi and Hao Zhang
Catalysts 2025, 15(8), 715; https://doi.org/10.3390/catal15080715 - 27 Jul 2025
Viewed by 443
Abstract
Over efficient photocatalysts, CO2 photoreduction typically converts CO2 into low-carbon chemicals, which serve as raw materials for downstream synthesis processes. Here, an efficient composite photocatalyst heterojunction (Cu2O-u/g-C3N4) has been fabricated to reduce CO2. [...] Read more.
Over efficient photocatalysts, CO2 photoreduction typically converts CO2 into low-carbon chemicals, which serve as raw materials for downstream synthesis processes. Here, an efficient composite photocatalyst heterojunction (Cu2O-u/g-C3N4) has been fabricated to reduce CO2. Graphitic carbon nitride (g-C3N4) was synthesized via thermal polymerization of urea at 550 °C, while pre-dispersed Cu2O derived from urea pyrolysis (Cu2O-u) was prepared by thermal reduction of urea and CuCl2·2H2O at 180 °C. The heterojunction Cu2O-u/g-C3N4 was subsequently constructed through hydrothermal treatment at 180 °C. This heterojunction exhibited a bandgap of 2.10 eV, with dual optical absorption edges at 485 nm and above 800 nm, enabling efficient harvesting of solar light. Under 175 W mercury lamp irradiation, the heterojunction catalyzed liquid-phase CO2 photoreduction to formic acid, acetic acid, and methanol. Its formic acid production activity surpassed that of pristine g-C3N4 by 3.14-fold and TiO2 by 8.72-fold. Reaction media, hole scavengers, and reaction duration modulated product selectivity. In acetonitrile/isopropanol systems, formic acid and acetic acid production reached 579.4 and 582.8 μmol·h−1·gcat−1. Conversely, in water/triethanolamine systems, methanol production reached 3061.6 μmol·h−1·gcat−1, with 94.79% of the initial conversion retained after three cycles. Finally, this work ends with the conclusions of the CO2 photocatalytic reduction to formic acid, acetic acid, and methanol, and recommends prospects for future research. Full article
(This article belongs to the Section Photocatalysis)
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27 pages, 1893 KiB  
Article
Separating 2-Propanol and Water: A Comparative Study of Extractive Distillation, Salting-Out, and Extraction
by Aleksandra Sander, Marko Rogošić, Leonarda Frljak, Daniela Vasiljević, Iva Blažević and Jelena Parlov Vuković
Separations 2025, 12(8), 196; https://doi.org/10.3390/separations12080196 - 26 Jul 2025
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Abstract
Separating azeotropes is an important, difficult, and expensive task, in particular for the 2-propanol–water mixture. The literature on the problem is rich in modeling studies but often lacking even the simplest experimental confirmation. In this paper, extractive distillation, liquid–liquid equilibrium-based extraction, and salting-out [...] Read more.
Separating azeotropes is an important, difficult, and expensive task, in particular for the 2-propanol–water mixture. The literature on the problem is rich in modeling studies but often lacking even the simplest experimental confirmation. In this paper, extractive distillation, liquid–liquid equilibrium-based extraction, and salting-out were experimentally tested for the desired separation. Among the four tested extractive distillation entrainers, none was able—in the investigated experimental setup—to push the system over the azeotropic composition threshold. Four novel hydrophobic deep eutectic extraction media were tested for the desired separation, and those based on menthol or thymol with decanoic acid were found most promising. Among 16 tested salting-out agents, 5 of them produced two-liquid phases, and only 4 hydrophilic inorganic salts promoted 2-propanol separation, with sodium carbonate being the most promising candidate. The purity of the products was tested with FTIR and 1H-NMR. The experimental findings were compared with COSMO-RS model predictions, with moderate success. Full article
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