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47 pages, 7003 KiB  
Review
Phthalocyanines Conjugated with Small Biologically Active Compounds for the Advanced Photodynamic Therapy: A Review
by Kyrylo Chornovolenko and Tomasz Koczorowski
Molecules 2025, 30(15), 3297; https://doi.org/10.3390/molecules30153297 - 6 Aug 2025
Abstract
Phthalocyanines (Pcs) are well-established photosensitizers in photodynamic therapy, valued for their strong light absorption, high singlet oxygen generation, and photostability. Recent advances have focused on covalently conjugating Pcs, particularly zinc phthalocyanines (ZnPcs), with a wide range of small bioactive molecules to improve selectivity, [...] Read more.
Phthalocyanines (Pcs) are well-established photosensitizers in photodynamic therapy, valued for their strong light absorption, high singlet oxygen generation, and photostability. Recent advances have focused on covalently conjugating Pcs, particularly zinc phthalocyanines (ZnPcs), with a wide range of small bioactive molecules to improve selectivity, efficacy, and multifunctionality. These conjugates combine light-activated reactive oxygen species (ROS) production with targeted delivery and controlled release, offering enhanced treatment precision and reduced off-target toxicity. Chemotherapeutic agent conjugates, including those with erlotinib, doxorubicin, tamoxifen, and camptothecin, demonstrate receptor-mediated uptake, pH-responsive release, and synergistic anticancer effects, even overcoming multidrug resistance. Beyond oncology, ZnPc conjugates with antibiotics, anti-inflammatory drugs, antiparasitics, and antidepressants extend photodynamic therapy’s scope to antimicrobial and site-specific therapies. Targeting moieties such as folic acid, biotin, arginylglycylaspartic acid (RGD) and epidermal growth factor (EGF) peptides, carbohydrates, and amino acids have been employed to exploit overexpressed receptors in tumors, enhancing cellular uptake and tumor accumulation. Fluorescent dye and porphyrinoid conjugates further enrich these systems by enabling imaging-guided therapy, efficient energy transfer, and dual-mode activation through pH or enzyme-sensitive linkers. Despite these promising strategies, key challenges remain, including aggregation-induced quenching, poor aqueous solubility, synthetic complexity, and interference with ROS generation. In this review, the examples of Pc-based conjugates were described with particular interest on the synthetic procedures and optical properties of targeted compounds. Full article
(This article belongs to the Section Organic Chemistry)
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22 pages, 9293 KiB  
Article
Thermal Stability of the Ultra-Fine-Grained Structure and Mechanical Properties of AlSi7MgCu0.5 Alloy Processed by Equal Channel Angular Pressing at Room Temperature
by Miloš Matvija, Martin Fujda, Ondrej Milkovič, Marek Vojtko and Katarína Gáborová
Crystals 2025, 15(8), 701; https://doi.org/10.3390/cryst15080701 - 31 Jul 2025
Viewed by 182
Abstract
Understanding the limitations of cold-formed aluminum alloys in practice applications is essential, particularly due to the risk of substructural changes and a reduction in strength when exposed to elevated temperatures. In this study, the thermal stability of the ultra-fine-grained (UFG) structure formed by [...] Read more.
Understanding the limitations of cold-formed aluminum alloys in practice applications is essential, particularly due to the risk of substructural changes and a reduction in strength when exposed to elevated temperatures. In this study, the thermal stability of the ultra-fine-grained (UFG) structure formed by equal channel angular pressing (ECAP) at room temperature and the mechanical properties of the AlSi7MgCu0.5 alloy were investigated. Prior to ECAP, the plasticity of the as-cast alloy was enhanced by a heat treatment consisting of solution annealing, quenching, and artificial aging to achieve an overaged state. Four repetitive passes via ECAP route A resulted in the homogenization of eutectic Si particles within the α-solid solution, the formation of ultra-fine grains and/or subgrains with high dislocation density, and a significant improvement in alloy strength due to strain hardening. The main objective of this work was to assess the microstructural and mechanical stability of the alloy after post-ECAP annealing in the temperature range of 373–573 K. The UFG microstructure was found to be thermally stable up to 523 K, above which notable grain and/or subgrain coarsening occurred as a result of discontinuous recrystallization of the solid solution. Mechanical properties remained stable up to 423 K; above this temperature, a considerable decrease in strength and a simultaneous increase in ductility were observed. Synchrotron radiation X-ray diffraction (XRD) was employed to analyze the phase composition and crystallographic characteristics, while transmission electron microscopy (TEM) was used to investigate substructural evolution. Mechanical properties were evaluated through tensile testing, impact toughness testing, and hardness measurements. Full article
(This article belongs to the Special Issue Celebrating the 10th Anniversary of International Crystallography)
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13 pages, 1563 KiB  
Article
Activation of Peracetic Acid by Ozone for Recalcitrant Pollutant Degradation: Accelerated Kinetics, Byproduct Mitigation, and Microbial Inactivation
by Dihao Bai, Cong Liu, Siqing Zhang, Huiyu Dong, Lei Sun and Xiangjuan Yuan
Water 2025, 17(15), 2240; https://doi.org/10.3390/w17152240 - 28 Jul 2025
Viewed by 295
Abstract
Iopamidol (IPM), as a typical recalcitrant emerging pollutant and precursor of iodinated disinfection by-products (I-DBPs), is unsuccessfully removed by conventional wastewater treatment processes. This study comprehensively evaluated the ozone/peracetic acid (O3/PAA) process for IPM degradation, focusing on degradation kinetics, environmental impacts, [...] Read more.
Iopamidol (IPM), as a typical recalcitrant emerging pollutant and precursor of iodinated disinfection by-products (I-DBPs), is unsuccessfully removed by conventional wastewater treatment processes. This study comprehensively evaluated the ozone/peracetic acid (O3/PAA) process for IPM degradation, focusing on degradation kinetics, environmental impacts, transformation products, ecotoxicity, disinfection byproducts (DBPs), and microbial inactivation. The O3/PAA system synergistically activates PAA via O3 to generate hydroxyl radicals (OH) and organic radicals (CH3COO and CH3CO(O)O), achieving an IPM degradation rate constant of 0.10 min−1, which was significantly higher than individual O3 or PAA treatments. The degradation efficiency of IPM in the O3/PAA system exhibited a positive correlation with solution pH, achieving a maximum degradation rate constant of 0.23 min−1 under alkaline conditions (pH 9.0). Furthermore, the process demonstrated strong resistance to interference from coexisting anions, maintaining robust IPM removal efficiency in the presence of common aqueous matrix constituents. Furthermore, quenching experiments revealed OH dominated IPM degradation in O3/PAA system, while the direct oxidation by O3 and R-O played secondary roles. Additionally, based on transformation products (TPs) identification and ECOSAR predictions, the primary degradation pathways were elucidated and the potential ecotoxicity of TPs was systematically assessed. DBPs analysis after chlorination revealed that the O3/PAA (2.5:3) system achieved the lowest total DBPs concentration (99.88 μg/L), representing a 71.5% reduction compared to PAA alone. Amongst, dichloroacetamide (DCAM) dominated the DBPs profile, comprising > 60% of total species. Furthermore, the O3/PAA process achieved rapid 5–6 log reductions of E. coli. and S. aureus within 3 min. These results highlight the dual advantages of O3/PAA in effective disinfection and byproduct control, supporting its application in sustainable wastewater treatment. Full article
(This article belongs to the Section Wastewater Treatment and Reuse)
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15 pages, 6582 KiB  
Article
Microstructure and Mechanical Properties of the TC4 Alloy Obtained by Equal-Channel Angular Pressing in Combination with Reversible Hydrogen Alloying
by Irina P. Semenova, Luiza R. Rezyapova, Alexander V. Polyakov, Yuecheng Dong, Zhonggang Sun and Igor V. Alexandrov
Metals 2025, 15(8), 839; https://doi.org/10.3390/met15080839 - 27 Jul 2025
Viewed by 221
Abstract
This paper studies the effect of reversible hydrogen alloying of the TC4 alloy on the microstructure, phase composition, and mechanical properties before and after equal-channel angular pressing. It is shown that the introduction of 0.3% hydrogen followed by quenching from a temperature of [...] Read more.
This paper studies the effect of reversible hydrogen alloying of the TC4 alloy on the microstructure, phase composition, and mechanical properties before and after equal-channel angular pressing. It is shown that the introduction of 0.3% hydrogen followed by quenching from a temperature of 850 °C leads to the formation of a thin-plate α″-martensite, which made it possible to implement 6 passes (ε ~ 4.2) of pressing at 600 °C. As a result of the deformation of the TC4-H alloy and subsequent thermal vacuum treatment to remove hydrogen, an ultrafine-grained structure with an average size of the α-phase of 0.15 μm was formed, which led to strengthening of the alloy to 1490 MPa with a relative elongation of about 5% at room temperature. The reasons for a more significant refinement of the grain/subgrain structure and an increase in the tensile strength of the hydrogenated alloy after equal-channel angular pressing in comparison with hydrogen-free TC4 alloy are discussed. Full article
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16 pages, 3146 KiB  
Article
The Influence of Spheroidizing Annealing Process on the Microstructure and Low-Temperature Impact Toughness of Q235 Steel Used in Coal Explosion-Proof Equipment
by Hongkui Zhang, Yipeng Lan, Xinming Liu and Guanglong Li
Metals 2025, 15(8), 833; https://doi.org/10.3390/met15080833 - 25 Jul 2025
Viewed by 717
Abstract
To improve the low-temperature impact toughness of Q235B steel, this paper adopts a heat treatment method combining quenching and spheroidizing annealing to enhance its microstructure and properties and conducts a detailed analysis of the evolution of the microstructure of Q235 steel under the [...] Read more.
To improve the low-temperature impact toughness of Q235B steel, this paper adopts a heat treatment method combining quenching and spheroidizing annealing to enhance its microstructure and properties and conducts a detailed analysis of the evolution of the microstructure of Q235 steel under the spheroidizing annealing process. The results show that spheroidizing annealing at 700 °C has a significant spheroidizing effect on the pearlite structure: after 6 h of annealing, the room-temperature tensile strength reaches 522 MPa, the elongation is 31.28%, and the impact energy is 323.14 J; as the impact temperature decreases, the impact toughness of Q235B steel decreases, but the impact energy can still remain at 291.62 J under service conditions of −20 °C. This is attributed to the spherical cementite formed by spheroidizing annealing, which has better dispersibility and can reduce stress concentration, thereby improving the low-temperature impact toughness. Full article
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19 pages, 6026 KiB  
Article
Microstructure and Mechanical Properties of High-Speed Train Wheels: A Study of the Rim and Web
by Chun Gao, Yuanyuan Zhang, Tao Fan, Jia Wang, Huajian Song and Hang Su
Crystals 2025, 15(8), 677; https://doi.org/10.3390/cryst15080677 - 25 Jul 2025
Viewed by 315
Abstract
High-speed trains have revolutionized modern transportation with their exceptional speeds, yet the essence of this technological breakthrough resides in the train’s wheels. These components are engineered to endure extreme mechanical stresses while ensuring high safety and reliability. In this paper, we selected the [...] Read more.
High-speed trains have revolutionized modern transportation with their exceptional speeds, yet the essence of this technological breakthrough resides in the train’s wheels. These components are engineered to endure extreme mechanical stresses while ensuring high safety and reliability. In this paper, we selected the rim and web as representative components of the wheel and conducted a comprehensive and systematic study on their microstructure and mechanical properties. The wheels are typically produced through integral forging. To improve the mechanical performance of the wheel/rail contact surface (i.e., the tread), the rim is subjected to surface quenching or other heat treatments. This endows the rim with strength and hardness second only to the tread and lowers its ductility. This results in a more isotropic structure with improved fatigue resistance in low-cycle and high-cycle regimes under rotating bending. The web connects the wheel axle to the rim and retains the microstructure formed during the forging process. Its strength is lower than that of the rim, while its ductility is slightly better. The web satisfies current property standards, although the microstructure suggests further optimization may be achievable through heat treatment refinement. Full article
(This article belongs to the Special Issue Fatigue and Fracture of Crystalline Metal Structures)
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16 pages, 2103 KiB  
Article
Pilot-Scale Fenton-like System for Wastewater Treatment Using Iron Mud Carbon Catalyst
by Lia Wang, Lan Liang, Jinglei Xu, Yanshan Wang, Beibei Yan, Guanyi Chen, Ning Li and Li’an Hou
Appl. Sci. 2025, 15(15), 8210; https://doi.org/10.3390/app15158210 - 23 Jul 2025
Viewed by 222
Abstract
Fenton oxidation can contribute to meeting effluent standards for COD in actual wastewater treatment plant effluents. However, Fenton oxidation is prone to produce iron sludge waste. The application of heterogeneous Fenton-like systems based on Fenton iron mud carbon in wastewater treatment plants is [...] Read more.
Fenton oxidation can contribute to meeting effluent standards for COD in actual wastewater treatment plant effluents. However, Fenton oxidation is prone to produce iron sludge waste. The application of heterogeneous Fenton-like systems based on Fenton iron mud carbon in wastewater treatment plants is essential for Fenton iron mud reduction and recycling. In this study, a Fenton iron mud carbon catalyst/Ferrate salts/H2O2 (FSC/Fe(VI)/H2O2) system was developed to remove chemical oxygen demand (COD) from secondary effluents at the pilot scale. The results showed that the FSC/Fe(VI)/H2O2 system exhibited excellent COD removal performance with a removal rate of 57% under slightly neutral conditions in laboratory experiments. In addition, the effluent COD was stabilized below 40 mg·L−1 for 65 days at the pilot scale. Fe(IV) and 1O2 were confirmed to be the main active species in the degradation process through electron paramagnetic resonance (EPR) and quenching experiments. C=O, O-C=O, N sites and Fe0 were responsible for the generation of Fe(IV) and 1O2 in the FSC/Fe(VI)/H2O2 system. Furthermore, the cost per ton of water treated by the pilot-scale FSC/Fe(VI)/H2O2 system was calculated to be only 0.6209 USD/t, further confirming the application potential of the FSC/Fe(VI)/H2O2 system. This study promotes the engineering application of heterogeneous Fenton-like systems for water treatment. Full article
(This article belongs to the Section Green Sustainable Science and Technology)
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15 pages, 4359 KiB  
Article
Phase Transformations During Heat Treatment of a CPM AISI M4 Steel
by Maribel L. Saucedo-Muñoz, Valeria Miranda-Lopez, Felipe Hernandez-Santiago, Carlos Ferreira-Palma and Victor M. Lopez-Hirata
Metals 2025, 15(7), 818; https://doi.org/10.3390/met15070818 - 21 Jul 2025
Viewed by 233
Abstract
The phase transformations of Crucible Particle Metallurgy (CPM) American Iron and Steel Institute (AISI) M4 steel were studied during heat treatments using a CALPHAD-based method. The calculated results were compared with experimental observations. The optimum austenitizing temperature was determined to be about 1120 [...] Read more.
The phase transformations of Crucible Particle Metallurgy (CPM) American Iron and Steel Institute (AISI) M4 steel were studied during heat treatments using a CALPHAD-based method. The calculated results were compared with experimental observations. The optimum austenitizing temperature was determined to be about 1120 °C using Thermo-Calc software (2024b). Air-cooling and quenching treatments led to the formation of martensite with a hardness of 63–65 Rockwell C (HRC). The annealing treatment promoted the formation of the equilibrium ferrite and carbide phases and resulted in a hardness of 24 HRC. These findings with regard to phases and microconstituents are in agreement with the predictions derived from a Thermo-Calc-calculated time–temperature–transformation diagram at 1120 °C. Additionally, the primary carbides, MC and M6C, which formed prior to the heat treatment and had a minor influence on the quenched hardness. In contrast, the tempering process primarily led to the formation of fine secondary M6C carbides, which hardened the tempered martensite to 57 HRC. The present work demonstrates the application of a CALPHAD-based methodology to the design and microstructural analysis of tool steels. Full article
(This article belongs to the Special Issue Advances in Steels: Heat Treatment, Microstructure and Properties)
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15 pages, 4083 KiB  
Article
Tribological and Corrosion Effects from Electrodeposited Ni-hBN over SS304 Substrate
by Suresh Velayudham, Elango Natarajan, Kalaimani Markandan, Kaviarasan Varadaraju, Santhosh Mozhuguan Sekar, Gérald Franz and Anil Chouhan
Lubricants 2025, 13(7), 318; https://doi.org/10.3390/lubricants13070318 - 21 Jul 2025
Viewed by 431
Abstract
The aim of the present study is to investigate the influence of Nickel–Hexagonal Boron Nitride (Ni-hBN) nanocomposite coatings, deposited using the pulse reverse current electrodeposition technique. This experimental study focuses on assessing the tribological and corrosion properties of the produced coatings on the [...] Read more.
The aim of the present study is to investigate the influence of Nickel–Hexagonal Boron Nitride (Ni-hBN) nanocomposite coatings, deposited using the pulse reverse current electrodeposition technique. This experimental study focuses on assessing the tribological and corrosion properties of the produced coatings on the SS304 substrate. The microhardness of the as-deposited (AD) sample and heat-treated (HT) sample were 49% and 83.8% higher compared to the control sample. The HT sample exhibited a grain size which was approximately 9.7% larger than the AD sample owing to the expansion–contraction mechanism of grains during heat treatment and sudden quenching. Surface roughness reduced after coating, where the Ni-hBN-coated sample measured a roughness of 0.43 µm compared to 0.48 µm for the bare surface. The average coefficient of friction for the AD sample was 42.4% lower than the bare surface owing to the self-lubricating properties of nano hBN. In particular, the corrosion rate of the AD sample was found to be 0.062 mm/year, which was lower than values reported in other studies. As such, findings from the present study can be particularly beneficial for applications in the automotive and aerospace industries, where enhanced wear resistance, reduced friction, and superior corrosion protection are critical for components such as engine parts, gears, bearings and shafts. Full article
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14 pages, 1393 KiB  
Article
Mitigating Water Stress and Enhancing Aesthetic Quality in Off-Season Potted Curcuma cv. ‘Jasmine Pink’ via Potassium Silicate Under Deficit Irrigation
by Vannak Sour, Anoma Dongsansuk, Supat Isarangkool Na Ayutthaya, Soraya Ruamrungsri and Panupon Hongpakdee
Horticulturae 2025, 11(7), 856; https://doi.org/10.3390/horticulturae11070856 - 20 Jul 2025
Viewed by 410
Abstract
Curcuma spp. is a popular ornamental crop valued for its vibrant appearance and suitability for both regular and off-season production. As global emphasis on freshwater conservation increases and with a demand for compact potted plants, reducing water use while maintaining high aesthetic quality [...] Read more.
Curcuma spp. is a popular ornamental crop valued for its vibrant appearance and suitability for both regular and off-season production. As global emphasis on freshwater conservation increases and with a demand for compact potted plants, reducing water use while maintaining high aesthetic quality presents a key challenge for horticulturists. Potassium silicate (PS) has been proposed as a foliar spray to alleviate plant water stress. This study aimed to evaluate the effects of PS on growth, ornamental traits, and photosynthetic parameters of off-season potted Curcuma cv. ‘Jasmine Pink’ under deficit irrigation (DI). Plants were subjected to three treatments in a completely randomized design: 100% crop evapotranspiration (ETc), 50% ETc, and 50% ETc with 1000 ppm PS (weekly sprayed on leaves for 11 weeks). Both DI treatments (50% ETc and 50% ETc + PS) reduced plant height by 7.39% and 9.17%, leaf number by 16.99% and 7.03%, and total biomass by 21.13% and 20.58%, respectively, compared to 100% ETc. Notably, under DI, PS-treated plants maintained several parameters equivalent to the 100% ETc treatment, including flower bud emergence, blooming period, green bract number, effective quantum yield of PSII (ΔF/Fm′), and electron transport rate (ETR). In addition, PS application increased leaf area by 8.11% and compactness index by 9.80% relative to untreated plants. Photosynthetic rate, ΔF/Fm′, and ETR increased by 31.52%, 13.63%, and 9.93%, while non-photochemical quenching decreased by 16.51% under water-limited conditions. These findings demonstrate that integrating deficit irrigation with PS foliar application can enhance water use efficiency and maintain ornamental quality in off-season potted Curcuma, promoting sustainable water management in horticulture. Full article
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24 pages, 11312 KiB  
Article
Effect of Thermomechanical Processing on Porosity Evolution and Mechanical Properties of L-PBF AISI 316L Stainless Steel
by Patrik Petroušek, Róbert Kočiško, Andrea Kasperkevičová, Dávid Csík and Róbert Džunda
Metals 2025, 15(7), 789; https://doi.org/10.3390/met15070789 - 12 Jul 2025
Viewed by 325
Abstract
Thermomechanical processing has a significant impact on the porosity and mechanical properties of AISI 316L stainless steel produced by laser powder bed fusion (L-PBF). This work evaluated the effect of three heat treatment conditions: as-built (HT0), annealed at 650 °C for 3 h [...] Read more.
Thermomechanical processing has a significant impact on the porosity and mechanical properties of AISI 316L stainless steel produced by laser powder bed fusion (L-PBF). This work evaluated the effect of three heat treatment conditions: as-built (HT0), annealed at 650 °C for 3 h with air cooling (HT1), and annealed at 1050 °C for 1 h followed by water quenching (HT2), combined with cold and hot rolling at different strain levels. The most pronounced improvement was observed after 20% hot rolling followed by water quenching (HR + WQ), which reduced porosity to 0.05% and yielded the most spherical pores, with a circularity factor (fcircle) of 0.90 and an aspect ratio (AsR) of 1.57. At elevated temperatures, the matrix becomes more pliable, which promotes pore closure and helps reduce stress concentrations. On the other hand, applying heat treatment without causing deformation resulted in the pores growing and increasing porosity in the build direction. The fractography supported these findings, showing a transition from brittle to more ductile fracture surfaces. Heat treatment combined with plastic deformation effectively reduced internal defects and improved both structural integrity and strength. Full article
(This article belongs to the Special Issue Metal Forming and Additive Manufacturing)
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27 pages, 10163 KiB  
Article
Through-Scale Numerical Investigation of Microstructure Evolution During the Cooling of Large-Diameter Rings
by Mariusz Wermiński, Mateusz Sitko and Lukasz Madej
Materials 2025, 18(14), 3237; https://doi.org/10.3390/ma18143237 - 9 Jul 2025
Viewed by 281
Abstract
The prediction of microstructure evolution during thermal processing plays a crucial role in tailoring the mechanical properties of metallic components. Therefore, this work presents a comprehensive, multiscale modelling approach to simulating phase transformations in large-diameter steel rings during cooling. A finite-element-based thermal model [...] Read more.
The prediction of microstructure evolution during thermal processing plays a crucial role in tailoring the mechanical properties of metallic components. Therefore, this work presents a comprehensive, multiscale modelling approach to simulating phase transformations in large-diameter steel rings during cooling. A finite-element-based thermal model was first used to simulate transient temperature distributions in a large-diameter ring under different cooling conditions, including air and water quenching. These thermal histories were subsequently employed in two complementary phase transformation models of different levels of complexity. The Avrami model provides a first-order approximation of the evolution of phase volume fractions, while a complex full-field cellular automata approach explicitly simulates the nucleation and growth of ferrite grains at the microstructural level, incorporating local kinetics and microstructural heterogeneities. The results highlight the sensitivity of final grain morphology to local cooling rates within the ring and initial austenite grain sizes. Simulations demonstrated the formation of heterogeneous microstructures, particularly pronounced in the ring’s surface region, due to sharp thermal gradients. This approach offers valuable insights for optimising heat treatment conditions to obtain high-quality large-diameter ring products. Full article
(This article belongs to the Section Materials Simulation and Design)
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50 pages, 3939 KiB  
Review
Targeting Gram-Negative Bacterial Biofilm with Innovative Therapies: Communication Silencing Strategies
by Milka Malešević and Branko Jovčić
Future Pharmacol. 2025, 5(3), 35; https://doi.org/10.3390/futurepharmacol5030035 - 3 Jul 2025
Viewed by 638
Abstract
Biofilm-associated infections caused by Gram-negative bacteria, especially multidrug-resistant strains, frequently occur in intensive care units and represent a major therapeutic challenge. The economic burden of biofilm-associated infections is considerable, making the search for new treatment approaches a focal point for policymakers and scientific [...] Read more.
Biofilm-associated infections caused by Gram-negative bacteria, especially multidrug-resistant strains, frequently occur in intensive care units and represent a major therapeutic challenge. The economic burden of biofilm-associated infections is considerable, making the search for new treatment approaches a focal point for policymakers and scientific funding bodies. Biofilm formation is regulated by quorum sensing (QS), a population density-dependent communication mechanism between cells mediated by small diffusible signaling molecules. QS modulates various intracellular processes, and some features of QS are common to all Gram-negative bacteria. While there are differences in the QS regulatory networks of different Gram-negative bacterial species, a common feature of most Gram-negative bacteria is the ability of N-acylhomoserine lactones (AHL) as inducers to diffuse across the bacterial membrane and interact with receptors located either in the cytoplasm or on the inner membrane. Targeting QS by inhibiting the synthesis, transport, or perception of signaling molecules using small molecules, quorum quenching enzymes, antibodies, combinatorial therapies, or nanoparticles is a promising strategy to combat virulence. In-depth knowledge of biofilm biology, antibiotic susceptibility, and penetration mechanisms, as well as a deep understanding of anti-QS agents, will contribute to the development of antimicrobial therapies to combat biofilm infections. Advancing antimicrobial therapies against biofilm infections requires a deep understanding of biofilm biology, antibiotic susceptibility, penetration mechanisms, and anti-QS strategies. This can be achieved through in vivo and clinical studies, supported by state-of-the-art tools such as machine learning and artificial intelligence. Full article
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19 pages, 26828 KiB  
Article
Synergistic Effects of Elevated CO2 and Enhanced Light Intensity on Growth Dynamics, Stomatal Phenomics, Leaf Anatomy, and Photosynthetic Performance in Tomato Seedlings
by Tonghua Pan, Wenya Zhang, Wentao Du, Bingyan Fu, Xiaoting Zhou, Kai Cao, Encai Bao, Yunlong Wang and Gaoqiang Lv
Horticulturae 2025, 11(7), 760; https://doi.org/10.3390/horticulturae11070760 - 1 Jul 2025
Viewed by 361
Abstract
Elevated [CO2] enhances light interception and carboxylation efficiency in plants. The combined effects of [CO2] and photosynthetic photon flux density (PPFD) on stomatal morphology, leaf anatomy, and photosynthetic capacity in tomato seedlings remain unclear. This study subjected tomato seedlings [...] Read more.
Elevated [CO2] enhances light interception and carboxylation efficiency in plants. The combined effects of [CO2] and photosynthetic photon flux density (PPFD) on stomatal morphology, leaf anatomy, and photosynthetic capacity in tomato seedlings remain unclear. This study subjected tomato seedlings (Solanum lycopersicum Mill. cv. Jingpeng No.1) to two [CO2] (ambient [a[CO2], 400 µmol·mol−1] and enriched [e[CO2], 800 µmol·mol−1]) and three PPFD levels (L; low[Ll: 200 µmol·m−2·s−1], moderate[Lm: 300 µmol·m−2·s−1], and high[Lh: 400 µmol·m−2·s−1]) to assess their interactive impacts. Results showed that e[CO2] and increased PPFD synergistically improved relative growth rate and net assimilation rate while reducing specific leaf area and leaf area ratio. Notably, e[CO2] decreased stomatal aperture (−13.81%) and density (−27.76%), whereas elevated PPFD promoted stomatal morphological adjustments. Additionally, Leaf thickness increased by 72.98% under e[CO2], with Lm and Lh enhancing this by 10.79% and 41.50% compared to Ll. Furthermore, photosynthetic performance under e[CO2] was further evidenced by improved chlorophyll fluorescence parameters (excluding non-photochemical quenching). While both e[CO2] and increased PPFD Photosynthetic performance under e[CO2] was further evidenced by improved chlorophyll fluorescence parameters (excluding non-photochemical quenching). Moreover, e[CO2]-Lh treatment maximized total dry mass and seedling health index. Correlation analysis indicated that synergistic optimization of stomatal traits and leaf structure under a combination of e[CO2] and increased PPFD enhanced light harvesting and CO2 diffusion, thereby promoting carbon assimilation. These findings highlight e[CO2]-Lh as an optimal strategy for tomato seedling growth, providing empirical guidance for precision CO2 fertilization and light management in controlled cultivation. Full article
(This article belongs to the Special Issue Latest Advances in Horticulture Production Equipment and Technology)
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16 pages, 3716 KiB  
Article
Water Demand and Photosynthetic Performance of Tomatoes Grown Hydroponically Under Increasing Nitrogen Concentrations
by Pablo Rugero Magalhães Dourado, Martha Katharinne Silva Souza Paulino, Lucas Yago de Carvalho Leal, Cicero Aparecido Ferreira Araújo, José Alfredo Nunes, Emidio Cantídio de Oliveira, José Amilton Santos Júnior, Aline de Camargo Santos, Diego Arruda Huggins de Sá Leitão, Márcio Renato Nunes, Bruce Schaffer and Edivan Rodrigues de Souza
Water 2025, 17(13), 1951; https://doi.org/10.3390/w17131951 - 29 Jun 2025
Viewed by 451
Abstract
Water and nitrogen (N) availability are among the primary limiting factors for the productivity of tomato (Solanum licopersicum L.). This study evaluated the interaction between these factors by assessing the effects of different N concentrations (85.5, 128.3, 171.0, 213.8, and 256.1 ppm [...] Read more.
Water and nitrogen (N) availability are among the primary limiting factors for the productivity of tomato (Solanum licopersicum L.). This study evaluated the interaction between these factors by assessing the effects of different N concentrations (85.5, 128.3, 171.0, 213.8, and 256.1 ppm N) on the water consumption, growth, and photosynthetic efficiency of hydroponically-grown tomato plants. The variables that were analyzed included the leaf N content, leaf chlorophyll index (LCI), maximum quantum efficiency of photosystem II (the ratio of variable to maximum chlorophyll fluorescence; Fv/Fm), non-photochemical quenching (NPQ), fresh mass (FM), dry mass (DM), cumulative water consumption, and water use efficiency (WUE). Increasing N concentrations led to higher water consumption and FM accumulation. Dry biomass was quadratically related to the N concentration, which peaked between doses of 213.8 and 256.1 ppm N. The LCI and Fv/Fm increased with the N supply, reaching a peak at N concentrations above 171 ppm, and then remained relatively constant. Conversely, the NPQ was reduced at the highest N level (256.1 ppm), which indicated diminished excess energy dissipation capacity. The highest WUE was observed at 213.8 ppm N, which was associated with greater DM and reduced water consumption compared to the highest N treatment. These findings suggest that the N concentration significantly affects the biomass production and water use in hydroponically-grown tomato plants, with 213.8 ppm N being the most efficient for vegetative growth under the studied conditions. Full article
(This article belongs to the Special Issue Soil Water Use and Irrigation Management)
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