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28 pages, 4127 KB  
Article
Deep Residual Learning for Face Anti-Spoofing: A Mathematical Framework for Optimized Skip Connections
by Ardak Nurpeisova, Anargul Shaushenova, Oleksandr Kuznetsov, Aidar Ispussinov, Zhazira Mutalova and Akmaral Kassymova
Technologies 2025, 13(9), 413; https://doi.org/10.3390/technologies13090413 - 11 Sep 2025
Viewed by 352
Abstract
Face anti-spoofing is crucial for protecting biometric authentication systems. Presentation attacks using 3D masks and high-resolution printed images present detection challenges for existing methods. In this paper, we introduce a family of specialized CNN architectures, AttackNet, designed for robust face anti-spoofing with optimized [...] Read more.
Face anti-spoofing is crucial for protecting biometric authentication systems. Presentation attacks using 3D masks and high-resolution printed images present detection challenges for existing methods. In this paper, we introduce a family of specialized CNN architectures, AttackNet, designed for robust face anti-spoofing with optimized residual connections and activation functions. The study includes the development of four architectures: baseline LivenessNet, AttackNetV1 with concatenation-based skip connections, AttackNetV2.1 with optimized activation functions, and AttackNetV2.2 with efficient addition-based residual learning. Our analysis demonstrates that element-wise addition in skip connections reduces parameters from 8.4 M to 4.2 M while maintaining performance. A comprehensive evaluation was conducted on four benchmark datasets: MSSpoof, 3DMAD, CSMAD, and Replay-Attack. Results show high accuracy (approaching 100%) on the 3DMAD, CSMAD, and Replay-Attack datasets. On the more challenging MSSpoof dataset, AttackNetV1 achieved 99.6% accuracy with an HTER of 0.004, outperforming the baseline LivenessNet (94.35% accuracy, 0.056 HTER). Comparative analysis with state-of-the-art methods confirms the superiority of the proposed approach. AttackNetV2.2 demonstrates an optimal balance between accuracy and computational efficiency, requiring 16.1 MB of memory compared to 32.1 MB for other AttackNet variants. Training time analysis shows twice the speed for AttackNetV2.2 compared to AttackNetV1. Architectural ablation studies highlight the crucial role of residual connections, batch normalization, and suitable dropout rates. Statistical significance testing verifies the reliability of the results (p-value < 0.001). The proposed architectures show excellent generalization ability and practical usefulness for real-world deployment in mobile and embedded systems. Full article
(This article belongs to the Special Issue Research on Security and Privacy of Data and Networks)
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16 pages, 634 KB  
Article
Effects of Adding Lactobacillus Inoculants on the Nutritional Value of Sesbania cannabina and Whole Corn Mixed Silage
by Tianzhu Yin, Shuai Song, Xianwei Song, Duofeng Pan, Qinghua Zhao, Liwen He, Ding Tang, Yajun Jia, Xiaofeng Cao, Xian Deng and Wei Zhang
Agriculture 2025, 15(18), 1913; https://doi.org/10.3390/agriculture15181913 - 9 Sep 2025
Viewed by 325
Abstract
This study evaluated the potential of utilizing Sesbania cannabina, produced during saline–alkali soil improvement, as a high-quality feed resource for ruminants. Mixed silages were prepared by combining S. cannabina and whole corn at ratios of 1:1 and 1:3, with or without a [...] Read more.
This study evaluated the potential of utilizing Sesbania cannabina, produced during saline–alkali soil improvement, as a high-quality feed resource for ruminants. Mixed silages were prepared by combining S. cannabina and whole corn at ratios of 1:1 and 1:3, with or without a compound Lactobacillus (LAB) inoculant, and were assessed for fermentation quality, nutrient composition, ruminal degradation, intestinal digestibility, and energy value. Results: The addition of Lactobacillus (LAB) inoculants increased lactic acid content, crude protein effective degradability (CPED), gross energy (GE), and dry matter apparent digestibility (DMAD), while decreasing ammonia nitrogen (NH3-N), acetic acid (AA), propionic acid (PA), neutral detergent fiber (NDF), acid detergent fiber (ADF), rumen undegradable protein (RUP), intestinal crude protein degradability (ICPD), and intestinal digestible crude protein (IDCP). Increasing the proportion of whole corn increased dry matter (DM) and gross energy (GE), while reducing crude protein (CP), NDF, ADF, Ash, rumen degradable protein (RDP), RUP, IDCP, and the effective ruminal degradability of NDF (NDFED) and ADF (ADFED). Overall, a 1:1 mixing ratio maximized S. cannabina utilization without compromising feeding value, and LAB inoculation ensured successful ensiling while enhancing nutrient utilization. Full article
(This article belongs to the Section Farm Animal Production)
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18 pages, 1047 KB  
Article
Protein Functional Effector (pfe) Noncoding RNAS Are Identical to Fragments from Various Noncoding RNAs
by Roberto Patarca and William A. Haseltine
Int. J. Mol. Sci. 2025, 26(14), 6870; https://doi.org/10.3390/ijms26146870 - 17 Jul 2025
Viewed by 603
Abstract
Protein functional effector (pfe)RNAs were introduced in 2015 as PIWI-interacting-like small noncoding (nc)RNAs and were later categorized as a novel group based on being 2′-O-methylated at their 3′-end, directly binding and affecting protein function, but not levels, and not matching known RNAs. Here, [...] Read more.
Protein functional effector (pfe)RNAs were introduced in 2015 as PIWI-interacting-like small noncoding (nc)RNAs and were later categorized as a novel group based on being 2′-O-methylated at their 3′-end, directly binding and affecting protein function, but not levels, and not matching known RNAs. Here, we document that human pfeRNAs match fragments of GenBank database-annotated human ncRNAs. PDLpfeRNAa matches the 3′-half fragment of a mitochondrial transfer (t)RNA, and PDLpfeRNAb matches a 28S ribosomal (r)RNA fragment. These PDLpfeRNAs are known to bind to tumor programmed death ligand (PD-L)1, enhancing or inhibiting its interaction with lymphocyte PD-1 and consequently tumor immune escape, respectively. In a validated 8-pfeRNA-set classifier for pulmonary nodule presence and benign vs. malignant nature, seven here match one or more of the following: transfer, micro, Y, PIWI, long (lnc)RNAs, and a PDLpfeRNAa fragment. The previously identified chromosomal locations of these pfeRNAs and their matches partially overlap. Another 2-pfeRNA set was previously determined to distinguish between controls, patients with pulmonary tuberculosis, and those with lung cancer. One pfeRNA, previously shown to bind p60-DMAD and affect apoptosis, complements small nucleolar RNA SNORD45C, matching smaller 18S rRNA and lncRNA segments. Thus, pfeRNAs appear to have a common origin with known multifunctional ncRNA fragments. Differential modification may contribute to the multifunctionality of ncRNAs. For instance, for tRNA fragments, stabilizing 3′-end 2′-O-methylation, 3′-aminoacylation, and glycosylation modifications may regulate protein function, translation, and extracellular effects, respectively. One ncRNA gene can encode multiple fragments, multiple genes can encode the same fragment, and differentially modified ncRNA fragments might synergize or antagonize each other. Full article
(This article belongs to the Special Issue Targeting RNA Molecules)
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33 pages, 1513 KB  
Article
Azirinyl-Substituted Nitrile Oxides: Generation and Use in the Synthesis of Isoxazole Containing Heterocyclic Hybrids
by Alexander S. Dudik, Timur O. Zanakhov, Ekaterina E. Galenko, Mikhail S. Novikov and Alexander F. Khlebnikov
Molecules 2025, 30(13), 2834; https://doi.org/10.3390/molecules30132834 - 2 Jul 2025
Viewed by 996
Abstract
The procedure for the generation of azirinyl-substituted nitrile oxides by the reaction of 2-(diazoacetyl)-2H-azirines with tert-butyl nitrite while preserving the azirine ring has been developed. The [3+2] cycloaddition of azirinyl-substituted nitrile oxides to terminal acetylenes produced azirinyl(isoxazolyl)ketones with various substituents [...] Read more.
The procedure for the generation of azirinyl-substituted nitrile oxides by the reaction of 2-(diazoacetyl)-2H-azirines with tert-butyl nitrite while preserving the azirine ring has been developed. The [3+2] cycloaddition of azirinyl-substituted nitrile oxides to terminal acetylenes produced azirinyl(isoxazolyl)ketones with various substituents in position 3 of azirine and position 5 of isoxazole fragments in a 51–91% yield at room temperature in DCM. DFT calculations and experimental data are consistent with the assumption that the formation of azirinyl-substituted nitrile oxides is accelerated by the acid catalyst. Cycloadducts of nitrile oxides with aryl/hetarylacetylenes and DMAD can be obtained by catalysis with boron trifluoride etherate, which significantly expands the scope of application of the reaction. Expansion of the azirine ring of the prepared cycloadducts allows obtaining a wide range of structurally diverse functionalized isoxazole-containing heterocyclic hybrids. LED light induces isomerization of the azirinecarbonyl moiety of the azirinyl(isoxazolyl)ketones, resulting in the formation of a set of 3,5’-biisoxazoles in a 40–71% yield, while the catalytic reaction of the azirine moiety with 1,3-diketones opens the way to pyrrole- and isoxazole-containing hybrids. 2-(Isoxazole-3-ylcarbonyl)-3-arylazirines were also easily isomerized to 3-(oxazol-5-yl)isoxazoles in methanol in the presence of excess potassium carbonate at room temperature. Full article
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29 pages, 20113 KB  
Article
Optimized Hydrothermal Alteration Mapping in Porphyry Copper Systems Using a Hybrid DWT-2D/MAD Algorithm on ASTER Satellite Remote Sensing Imagery
by Samane Esmaelzade Kalkhoran, Seyyed Saeed Ghannadpour and Amin Beiranvand Pour
Minerals 2025, 15(6), 626; https://doi.org/10.3390/min15060626 - 9 Jun 2025
Viewed by 754
Abstract
Copper is typically acknowledged as a critical mineral and one of the vital components of various of today’s fast-growing green technologies. Porphyry copper systems, which are an important source of copper and molybdenum, typically consist of large volumes of hydrothermally altered rocks, mainly [...] Read more.
Copper is typically acknowledged as a critical mineral and one of the vital components of various of today’s fast-growing green technologies. Porphyry copper systems, which are an important source of copper and molybdenum, typically consist of large volumes of hydrothermally altered rocks, mainly around porphyry copper intrusions. Mapping hydrothermal alteration zones associated with porphyry copper systems is one of the most important indicators for copper exploration, especially using advanced satellite remote sensing technology. This paper presents a sophisticated remote sensing-based method that uses ASTER satellite imagery (SWIR bands 4 to 9) to identify hydrothermal alteration zones by combining the discrete wavelet transform (DWT) and the median absolute deviation (MAD) algorithms. All six SWIR bands (bands 4–9) were analyzed independently, and band 9, which showed the most consistent spatial patterns and highest validation accuracy, was selected for final visualization and interpretation. The MAD algorithm is effective in identifying spectral anomalies, and the DWT enables the extraction of features at different scales. The Urmia–Dokhtar magmatic arc in central Iran, which hosts the Zafarghand porphyry copper deposit, was selected as a case study. It is a hydrothermal porphyry copper system with complex alteration patterns that make it a challenging target for copper exploration. After applying atmospheric corrections and normalizing the data, a hybrid algorithm was implemented to classify the alteration zones. The developed classification framework achieved an accuracy of 94.96% for phyllic alteration and 89.65% for propylitic alteration. The combination of MAD and DWT reduced the number of false positives while maintaining high sensitivity. This study demonstrates the high potential of the proposed method as an accurate and generalizable tool for copper exploration, especially in complex and inaccessible geological areas. The proposed framework is also transferable to other porphyry systems worldwide. Full article
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22 pages, 1959 KB  
Article
DMFormer: Dense Memory Linformer for Image Captioning
by Yuting He and Zetao Jiang
Electronics 2025, 14(9), 1716; https://doi.org/10.3390/electronics14091716 - 23 Apr 2025
Cited by 1 | Viewed by 612
Abstract
Image captioning is a cross-task of computer vision and natural language processing, aiming to describe image content in natural language. Existing methods still have deficiencies in modeling the spatial location and semantic correlation between image regions. Furthermore, these methods often exhibit insufficient interaction [...] Read more.
Image captioning is a cross-task of computer vision and natural language processing, aiming to describe image content in natural language. Existing methods still have deficiencies in modeling the spatial location and semantic correlation between image regions. Furthermore, these methods often exhibit insufficient interaction between image features and text features. To address these issues, we propose a Linformer-based image captioning method, the Dense Memory Linformer for Image Captioning (DMFormer), which has lower time and space complexity than the traditional Transformer architecture. The DMFormer contains two core modules: the Relation Memory Augmented Encoder (RMAE) and the Dense Memory Augmented Decoder (DMAD). In the RMAE, we propose Relation Memory Augmented Attention (RMAA), which combines explicit spatial perception and implicit spatial perception. It explicitly uses geometric information to model the geometric correlation between image regions and implicitly constructs memory unit matrices to learn the contextual information of image region features. In the DMAD, we introduce Dense Memory Augmented Cross Attention (DMACA). This module fully utilizes the low-level and high-level features generated by the RMAE through dense connections, and constructs memory units to store prior knowledge of image and text. It learns the cross-modal associations between visual and linguistic features through an adaptive gating mechanism. Experimental results on the MS-COCO dataset show that the descriptions generated by the DMFormer are richer and more accurate, with significant improvements in various evaluation metrics compared to mainstream methods. Full article
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13 pages, 2660 KB  
Article
Bioaccumulation of Metals in Fish Collected from Macapá Urban Aquatic Environments (Brazilian Amazon) and the Risks to Human Health
by Debora Cristina Damasceno de Souza, Lucilene Finoto Viana, Fábio Kummrow, Claudia Andrea Lima Cardoso, Nathalya Alice de Lima, Izabelle Alexandra Rodrigues Lacerda, Bruno do Amaral Crispim, Alexeia Barufatti, Lúcio André Viana Dias and Alexandro Cezar Florentino
Toxics 2025, 13(2), 67; https://doi.org/10.3390/toxics13020067 - 21 Jan 2025
Cited by 4 | Viewed by 1769
Abstract
Macapá City, located in the Brazilian Amazon, faces critical aquatic pollution challenges due to inadequate sanitation infrastructure, leading to metal contamination in fish within its urban water bodies. Our study evaluated the concentrations of metals (Cu, Cd, Cr, Fe, Mn, Ni, Pb, Zn, [...] Read more.
Macapá City, located in the Brazilian Amazon, faces critical aquatic pollution challenges due to inadequate sanitation infrastructure, leading to metal contamination in fish within its urban water bodies. Our study evaluated the concentrations of metals (Cu, Cd, Cr, Fe, Mn, Ni, Pb, Zn, and Hg) in muscle tissues of fish from igarapés, ressaca areas, and canals. Samples were collected from six sampling sites to investigate the bioaccumulation of these metals and their potential human health risks. All metals were quantified by atomic absorption spectrometry, except Hg, which was quantified by inductively coupled plasma optical emission spectrometry. Metal concentrations were determined in three carnivorous and seven omnivorous fish species. Cd concentrations exceeded the Brazilian maximum limit established for human consumption in all fish species evaluated. The estimated daily intake (EDI) of Pb and Hg exceeded their reference doses. Our risk assessment, which combined the risk quotient (RQ) for individual metals and the risk index (RI) for metal mixtures, indicated health risks associated with the consumption of fish collected from the study areas. These results demonstrated a worrying exposure to metals (mainly Cd, Pb, and Hg), highlighting the need for environmental management measures and continuous monitoring to protect public health in vulnerable urban areas. Full article
(This article belongs to the Section Ecotoxicology)
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17 pages, 3564 KB  
Article
High Glucose Concentration on the Metabolic Activity of C6 Glia Cells: Implication in Alzheimer’s Disease
by Karla Aketzalli Hernández-Contreras, Fausto Rojas-Durán, María Elena Hernández-Aguilar, Deissy Herrera-Covarrubias, Marycarmen Godinez-Victoria, Jorge Manzo-Denes, César Antonio Pérez-Estudillo, Fernando Rafael Ramos-Morales, Rebeca Toledo-Cárdenas and Gonzalo Emiliano Aranda-Abreu
BioMed 2025, 5(1), 3; https://doi.org/10.3390/biomed5010003 - 9 Jan 2025
Viewed by 2346
Abstract
Background: Alzheimer’s disease (AD), the leading cause of dementia worldwide, poses an increasing global health burden, yet its pathogenesis remains poorly understood. Diabetes mellitus (DM), characterized by chronic hyperglycemia, has been identified as a significant risk factor for AD development, suggesting a [...] Read more.
Background: Alzheimer’s disease (AD), the leading cause of dementia worldwide, poses an increasing global health burden, yet its pathogenesis remains poorly understood. Diabetes mellitus (DM), characterized by chronic hyperglycemia, has been identified as a significant risk factor for AD development, suggesting a potential metabolic and molecular link between these diseases. Methods: This study examines the impact of sustained high glucose levels on astrocyte-like C6 glial cells, focusing on key cellular processes associated with AD. We evaluated mitochondrial function, oxidative stress, glucose uptake, and the expression of hallmark AD proteins, including β-amyloid and hyperphosphorylated tau. Results: Our findings demonstrate that high glucose exposure triggers mitochondrial hyperactivity, oxidative stress, and increased Tau phosphorylation, though β-amyloid levels were unaffected within the experimental timeframe. Conclusions: These results shed light on the early cellular dysfunctions contributing to the DM-AD connection, providing valuable insights into the metabolic pathways involved and identifying potential therapeutic targets to mitigate AD progression in individuals with DM. Full article
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17 pages, 1395 KB  
Article
Synthesis and Investigation of Tricyclic Isoquinoline Derivatives as Antibacterial Agents
by Matthew J. A. Phillips, Alison T. Ung, Elizabeth J. Harry, Jason Ashmore and Andrew M. McDonagh
BioChem 2025, 5(1), 1; https://doi.org/10.3390/biochem5010001 - 31 Dec 2024
Cited by 2 | Viewed by 2380
Abstract
Isoquinoline derivatives exhibit a range of biological properties, including antibacterial activity, and are thus attractive as a scaffold for developing broad-spectrum antibacterial compounds. A series of six isoquinoline-based compounds were synthesized using the reaction of 6,7-dimethoxy-1-methyl-3,4-dihydroisoquinoline with dimethyl acetylenedicarboxylate (DMAD) to provide the [...] Read more.
Isoquinoline derivatives exhibit a range of biological properties, including antibacterial activity, and are thus attractive as a scaffold for developing broad-spectrum antibacterial compounds. A series of six isoquinoline-based compounds were synthesized using the reaction of 6,7-dimethoxy-1-methyl-3,4-dihydroisoquinoline with dimethyl acetylenedicarboxylate (DMAD) to provide the tricyclic (2Z)-[2-oxo-5,6-dihydropyrrolo[2,1,a]isoquinolin-3-ylidene]-2-ethanoate. The [2 + 3] cycloaddition of DMAD with C-6 and C-7 substituted 1-methyl-3,4-dihydroisoquinolines proceeded using aryl ethers or unsubstituted compounds, but not with amine, amide or nitro moieties at the C-7 position. Compounds 8d and 8f were found to have antibacterial properties against some Gram-positive pathogens (Staphylococcus aureus8d = 16 µg/mL, 8f = 32 µg/mL; Streptococcus pneumoniae—8f = 32 µg/mL; and Enterococcus faecium—8d = 128 µg/mL, 8f = 64 µg/mL). Evaluation of their cytotoxic properties against mammalian cell lines revealed some cytotoxic effects (8b and 8d, 125 µM, 24 h, HEp-2 cells) and (8a, 8b, 8d = 125 µM, 8f = 62.5 µM, 24 h, McCoy B cells), suggesting limitations in their antibacterial applications without further development. Full article
(This article belongs to the Special Issue Feature Papers in BioChem)
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18 pages, 2476 KB  
Article
Design, Synthesis, and Evaluation of New Hybrid Derivatives of 5,6-Dihydro-4H-pyrrolo[3,2,1-ij]quinolin-2(1H)-one as Potential Dual Inhibitors of Blood Coagulation Factors Xa and XIa
by Anna A. Skoptsova, Athina Geronikaki, Nadezhda P. Novichikhina, Alexey V. Sulimov, Ivan S. Ilin, Vladimir B. Sulimov, Georgii A. Bykov, Nadezhda A. Podoplelova, Oleg V. Pyankov and Khidmet S. Shikhaliev
Molecules 2024, 29(2), 373; https://doi.org/10.3390/molecules29020373 - 11 Jan 2024
Cited by 2 | Viewed by 2451
Abstract
Cardiovascular diseases caused by blood coagulation system disorders are one of the leading causes of morbidity and mortality in the world. Research shows that blood clotting factors are involved in these thrombotic processes. Among them, factor Xa occupies a key position in the [...] Read more.
Cardiovascular diseases caused by blood coagulation system disorders are one of the leading causes of morbidity and mortality in the world. Research shows that blood clotting factors are involved in these thrombotic processes. Among them, factor Xa occupies a key position in the blood coagulation cascade. Another coagulation factor, XIa, is also a promising target because its inhibition can suppress thrombosis with a limited contribution to normal hemostasis. In this regard, the development of dual inhibitors as new generation anticoagulants is an urgent problem. Here we report the synthesis and evaluation of novel potential dual inhibitors of coagulation factors Xa and XIa. Based on the principles of molecular design, we selected a series of compounds that combine in their structure fragments of pyrrolo[3,2,1-ij]quinolin-2-one and thiazole, connected through a hydrazine linker. The production of new hybrid molecules was carried out using a two-stage method. The reaction of 5,6-dihydropyrrolo[3,2,1-ij]quinoline-1,2-diones with thiosemicarbazide gave the corresponding hydrazinocarbothioamides. The reaction of the latter with DMAD led to the target methyl 2-(4-oxo-2-(2-(2-oxo-5,6-dihydro-4H-pyrrolo[3,2,1-ij]quinolin-1(2H)-ylidene)hydrazineyl)thiazol-5(4H)-ylidene)acetates in high yields. In vitro testing of the synthesized molecules revealed that ten of them showed high inhibition values for both the coagulation factors Xa and XIa, and the IC50 value for some compounds was also assessed. The resulting structures were also tested for their ability to inhibit thrombin. Full article
(This article belongs to the Special Issue Anticoagulant and Antithrombotic Therapy)
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14 pages, 3092 KB  
Article
Synthesis of Non-Aromatic Pyrroles Based on the Reaction of Carbonyl Derivatives of Acetylene with 3,3-Diaminoacrylonitriles
by Pavel S. Silaichev, Lidia N. Dianova, Tetyana V. Beryozkina, Vera S. Berseneva, Andrey N. Maslivets and Vasiliy A. Bakulev
Molecules 2023, 28(8), 3576; https://doi.org/10.3390/molecules28083576 - 19 Apr 2023
Cited by 2 | Viewed by 1998
Abstract
The reaction of 3,3-diaminoacrylonitriles with DMAD and 1,2-dibenzoylacetylene was studied. It is shown that the direction of the reaction depends on the structure both of acetylene and of diaminoacrylonitrile. In the reaction of DMAD with acrylonitriles bearing a monosubstituted amidine group, 1-substituted 5-amino-2-oxo-pyrrole-3(2 [...] Read more.
The reaction of 3,3-diaminoacrylonitriles with DMAD and 1,2-dibenzoylacetylene was studied. It is shown that the direction of the reaction depends on the structure both of acetylene and of diaminoacrylonitrile. In the reaction of DMAD with acrylonitriles bearing a monosubstituted amidine group, 1-substituted 5-amino-2-oxo-pyrrole-3(2H)ylidenes are formed. On the other hand, a similar reaction of acrylonitriles containing the N,N-dialkylamidine group affords 1-NH-5-aminopyrroles. In both cases, pyrroles containing two exocyclic double bonds are formed in high yields. A radically different type of pyrroles containing one exocyclic C=C bond and sp3 hybrid carbon in the cycle is formed in reactions of 3,3-diaminoacrylonitriles with 1,2-diaroylacetylenes. As in reactions with DMAD, the interaction of 3,3-diaminoacrylonitriles with 1,2-dibenzoylacetylene can lead, depending on the structure of the amidine fragment, both to NH- and 1-substituted pyrroles. The formation of the obtained pyrrole derivatives is explained by the proposed mechanisms of the studied reactions. Full article
(This article belongs to the Special Issue Novelties in N-Heterocycles Chemistry: From Synthesis to Application)
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19 pages, 2707 KB  
Article
Pharmacological Targeting of Bcl-2 Induces Caspase 3-Mediated Cleavage of HDAC6 and Regulates the Autophagy Process in Colorectal Cancer
by Donglin Yang, Liujun He, Shuiqing Ma, Shiqiang Li, Yajun Zhang, Chunsheng Hu, Jiuhong Huang, Zhigang Xu, Dianyong Tang and Zhongzhu Chen
Int. J. Mol. Sci. 2023, 24(7), 6662; https://doi.org/10.3390/ijms24076662 - 3 Apr 2023
Cited by 13 | Viewed by 3202
Abstract
Compound 6d, a spiroindoline compound, exhibits antiproliferative capability against cancer cell lines. However, the exact underlying mechanism of this compound-mediated inhibitory capability remains unclear. Here, we showed that compound 6d is an inhibitor of Bcl-2, which suppresses CRC growth by inducing caspase [...] Read more.
Compound 6d, a spiroindoline compound, exhibits antiproliferative capability against cancer cell lines. However, the exact underlying mechanism of this compound-mediated inhibitory capability remains unclear. Here, we showed that compound 6d is an inhibitor of Bcl-2, which suppresses CRC growth by inducing caspase 3-mediated intrinsic apoptosis of mitochondria. Regarding the underlying mechanism, we identified HDAC6 as a direct substrate for caspase 3, and caspase 3 activation induced by compound 6d directly cleaves HDAC6 into two fragments. Moreover, the cleavage site was located at D1088 in the DMAD-S motif HDAC6. Apoptosis stimulated by compound 6d promoted autophagy initiation by inhibiting interaction between Bcl-2 and Beclin 1, while it led to the accumulation of ubiquitinated proteins and the reduction of autophagic flux. Collectively, our findings reveal that the Bcl-2-caspase 3-HDAC6 cascade is a crucial regulatory pathway of autophagy and identify compound 6d as a novel lead compound for disrupting the balance between apoptosis and autophagy. Full article
(This article belongs to the Special Issue Molecular Targets for Antiviral and Anticancer Drugs)
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30 pages, 10413 KB  
Article
Cetaceans in the Mediterranean Sea: Encounter Rate, Dominant Species, and Diversity Hotspots
by Guido Gnone, Michela Bellingeri, Sabina Airoldi, Joan Gonzalvo, Léa David, Nathalie Di-Méglio, Ana M. Cañadas, Aylin Akkaya, Tim Awbery, Barbara Mussi, Ilaria Campana, Marta Azzolin, Ayhan Dede, Arda M. Tonay, Clara Monaco, Giuliana Pellegrino, Paola Tepsich, Aurelie Moulins, Antonella Arcangeli, Hélène Labach, Aviad P. Scheinin, Yaly Mevorach, Roberto Carlucci, Francesca C. Santacesaria, Carla A. Chicote, Manel Gazo, Beatriz Tintore, Jessica Alessi, Alberta Mandich, Luca Bittau, Bruno Diaz Lopez, Caroline Azzinari, Gabriella La Manna, Daniela Silvia Pace, Donatella Decandia, Alberto Castelli, Silvio Nuti, Marie-Catherine Santoni, Alessandro Verga, Nicolas Tomasi, Cristina Giacoma, Matteo Costantino, Marta Falabrino and Arianna Azzellinoadd Show full author list remove Hide full author list
Diversity 2023, 15(3), 321; https://doi.org/10.3390/d15030321 - 22 Feb 2023
Cited by 29 | Viewed by 11941
Abstract
We investigated the presence and diversity of cetaceans in the Mediterranean Sea, analysing the data collected by 32 different research units, over a period of 15 years (2004–2018), and shared on the common web-GIS platform named Intercet. We used the encounter rate, the [...] Read more.
We investigated the presence and diversity of cetaceans in the Mediterranean Sea, analysing the data collected by 32 different research units, over a period of 15 years (2004–2018), and shared on the common web-GIS platform named Intercet. We used the encounter rate, the species prevalence, and the Shannon diversity index as parameters for data analysis. The results show that cetacean diversity, in the context of the Mediterranean basin, is generally quite low when compared with the eastern Atlantic, as few species, namely the striped dolphin, the bottlenose dolphin, the fin whale, and the sperm whale, dominate over all the others. However, some areas, such as the Alboran Sea or the north-western Mediterranean Sea, which includes the Pelagos Sanctuary (the Specially Protected Area of Mediterranean Interest located in the northern portion of the western basin), show higher levels of diversity and should be considered hotspots to be preserved. Primary production and seabed profile seem to be the two main drivers influencing the presence and distribution of cetaceans, with the highest levels of diversity observed in areas characterized by high levels of primary production and high bathymetric variability and gradient. This collective work underlines the importance of data sharing to deepen our knowledge on marine fauna at the scale of the whole Mediterranean Sea and encourages greater efforts in the networking process, also to accomplish the requirements of the Marine Strategy Framework Directive, with particular reference to Descriptor 1: biological diversity is maintained. Full article
(This article belongs to the Special Issue Biodiversity Conservation in Mediterranean Sea)
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13 pages, 2114 KB  
Article
Anion-Controlled Synthesis of Novel Guanidine-Substituted Oxanorbornanes
by Luka Barešić, Davor Margetić and Zoran Glasovac
Int. J. Mol. Sci. 2022, 23(24), 16036; https://doi.org/10.3390/ijms232416036 - 16 Dec 2022
Cited by 4 | Viewed by 2464
Abstract
The cycloaddition of simple alkyl-substituted guanidine derivatives is an interesting approach toward polycyclic superbases and guanidine-based organocatalysts. Due to the high nucleophilicity of guanidines, an aza-Michael reaction with dienophiles is more common and presents a huge obstacle in achieving the desired synthetic goal. [...] Read more.
The cycloaddition of simple alkyl-substituted guanidine derivatives is an interesting approach toward polycyclic superbases and guanidine-based organocatalysts. Due to the high nucleophilicity of guanidines, an aza-Michael reaction with dienophiles is more common and presents a huge obstacle in achieving the desired synthetic goal. Our preliminary investigations indicated that the proton could act as a suitable protecting group to regulate the directionality of the reaction. To investigate the role of the protonation state and type of anion, the reactivity of furfuryl guanidines with dimethyl acetylenedicarboxylate was explored. Furfuryl guanidines showed a strong reaction dependence on the nucleophilicity of the counterion and the structure of guanidine. While the reaction of DMAD with the guanidinium halides provided products of an aza-Michael addition, Diels–Alder cycloaddition occurred if non-nucleophilic hexafluorophosphate salts were used. Depending on the structure and the reaction conditions, oxanorbornadiene products underwent subsequent intramolecular cyclization. A tendency toward intramolecular cyclization was interpreted in terms of the pKa of different positions of the guanidine functionality in oxanorbornadienes. New polycyclic guanidines had a slightly decreased pKa in acetonitrile and well-defined geometry suitable for the buildup of selective sensors. Full article
(This article belongs to the Special Issue Feature Papers in Physical Chemistry and Chemical Physics 2022)
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12 pages, 2730 KB  
Article
New Cycloadditon Reaction of 2-Chloroprop-2-enethioamides with Dialkyl Acetylenedicarboxylates: Synthesis of Dialkyl 2-[4,5-bis(alkoxycarbonyl)-2-(aryl{alkyl}imino)-3(2H)-thienylidene]-1,3-dithiole-4,5-dicarboxylates
by Vladimir A. Ogurtsov and Oleg A. Rakitin
Molecules 2022, 27(20), 6887; https://doi.org/10.3390/molecules27206887 - 14 Oct 2022
Cited by 1 | Viewed by 1822
Abstract
The 1,3-dipolar cycloaddition of 1,2-dithiole-3-thiones with alkynes to form 1,3-dithioles is one of the most studied reactions in this class of polysulfur-containing heterocycles. Nucleophilic substitution of chlorine atoms in dimethyl 2-(1,2-dichloro-2-thioxoethylidene)-1,3-dithiole-4,5-dicarboxylate, which was obtained by addition one molecules of DMAD to 4,5-dichloro-3H [...] Read more.
The 1,3-dipolar cycloaddition of 1,2-dithiole-3-thiones with alkynes to form 1,3-dithioles is one of the most studied reactions in this class of polysulfur-containing heterocycles. Nucleophilic substitution of chlorine atoms in dimethyl 2-(1,2-dichloro-2-thioxoethylidene)-1,3-dithiole-4,5-dicarboxylate, which was obtained by addition one molecules of DMAD to 4,5-dichloro-3H-1,2-dithiole-3-thione, led to a series of 2-chloro-2-(1,3-dithiol-2-ylidene)ethanethioamides. Cycloaddition reaction of 2-chloro-2-(1,3-dithiol-2-ylidene)ethanethioamides with activated alkynes led to the unexpected formation of 2-(thiophen-3(2H)-ylidene)-1,3-dithioles via new intermediate, 1-(1,3-dithiol-2-ylidene)-N-phenylethan-1-yliumimidothioate. Structure of dimethyl 2-(4,5-bis(methoxycarbonyl)-2-(phenylimino)thiophen-3(2H)-ylidene)-1,3-dithiole-4,5-dicarboxylate was finally proven by single crystal X-ray diffraction study. Optimized reaction conditions and a mechanistic rationale for the 1,3-dipolar cycloaddition of novel intermediate are presented. Full article
(This article belongs to the Special Issue Polysulfur- and Sulfur-Nitrogen Heterocycles II)
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