Search Results (237)

This study evaluated how the addition of 5 wt% bioactive glass and 15 wt% short glass fibers to EQUIA Forte HT affects the microhardness, micromorphology, and elemental composition of demineralized dentin. Class I cavities in 28 human third molars were demineralized with 37% phosphoric acid and restored with: (1) Filtek Universal composite, (2) EQUIA Forte HT, (3) EQUIA Forte HT + 5wt% BAG, or (4) EQUIA Forte HT + 15wt% short glass fibers. After 4 weeks of storage in phosphate-buffered saline at 37 °C, the teeth were cut in half, obtaining two samples from each tooth (n = 14). Vickers microhardness (HV0.1) was measured on demineralized dentin 50–100 μm apical to the restoration interface. Representative specimens (n = 2) were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Data were analyzed with one-way ANOVA (α = 0.05). Unmodified EQUIA Forte HT showed the highest mean dentin microhardness recovery (25.06 ± 1.42 HV0.1), followed by composite (17.31 ± 0.66 HV0.1), BAG-modified (23.74 ± 1.37 HV0.1) and fiber-reinforced (22.15 ± 1.06 HV0.1) groups (p < 0.001, all pairwise comparisons p ≤ 0.039). Glass hybrids showed prominent Ca/P peaks; modified groups had elevated Si (BAG) and Al (fibers). SEM revealed smoother surfaces with fewer cracks in modified materials. Unmodified EQUIA Forte HT produced the highest short-term microhardness recovery, while BAG and fiber additions altered surface morphology and elemental composition but slightly reduced early hardness. Full article

Ultrahigh lateral resolution (UHLR) optical coherence tomography (OCT) technology, also called optical coherence microscopy (OCM), has gained popularity, especially in the field of biomedical imaging. In these systems, high numerical aperture (NA) Microscope objectives (MO) are employed in OCM systems to offer better than 3 µm lateral resolution. However, in the implemented broadband OCM configuration, the use of complex multi-element microscope objectives can reduce the detected returned signal compared with a simpler imaging lens configuration. This reduction in detected returned signals can become an important practical limitation in many OCM applications, particularly for biomedical imaging when high imaging speed is crucial. This study investigates whether a single off-the-shelf lens can provide a practical alternative to conventional MOs, achieving higher throughput while maintaining reasonable spatial resolution. We systematically evaluated 14 commercial lenses using Zemax OpticStudio simulations, identifying an aspherized achromatic lens (Edmund Optics #85302) that best met these key criteria. To validate its feasibility for OCM, performance was tested in both Full-Field Time-Domain OCM (FF-TD-OCM) and Line-Field Spectral-Domain OCM (LF-SD-OCM) configurations. Using a broadband composite Superluminescent Diode (SLD) source (750–920 nm), we quantified the resolvable features, axial resolution, and overall light transmission. The validated system demonstrated near-diffraction-limited performance. In the LF-SD-OCM setup, it successfully resolved features as fine as Group 8, Element 6, corresponding to a 2.2 µm line pair pitch (~1.1 µm line width) and achieved a 2.86 µm axial resolution in air. A through-focus comparison further showed practically useful contrast retention around focus. Additional imaging of onion epidermal tissue and ex vivo porcine corneal tissue demonstrated that the proposed lens could provide interpretable structural images on representative biological samples. Under the tested LF-SD-OCM detection configuration, the selected lens delivered approximately 2.0 dB higher returned signal than the Mitutoyo MY10X-823 objective according to 1.59× larger received signal. Full article

To improve Chrysanthemum tolerance to low temperatures and its adaptability to low autumn temperatures in Northeast China, we conducted the first genome-wide identification of the heat shock transcription factors (Hsfs) in Chrysanthemum indicum under low-temperature stress. Based on genome-wide analyses, we identified 14 CiHsf genes in Chrysanthemum indicum. Based on structural characteristics, the genes were grouped into two subfamilies, comprising 10 HsfA and four HsfB members, with no representatives of the HsfC subfamily detected. CiHsf1~CiHsf14 were located on seven chromosomes, and their promoter regions harbored numerous cis-acting elements associated with responses to low temperature, hormones, and light. Tissue-specific expression profiling revealed that seven CiHsf genes were predominantly expressed in roots, two in stems, three in leaves, and two in flowers. The analysis of low-temperature expression characteristics showed that CiHsf2, CiHsf5, CiHsf8, and CiHsf10 were significantly upregulated following cold acclimation, indicating that these genes may participate in the low-temperature response mechanism of Chrysanthemum indicum. Here, we demonstrated that transient transformation of Chrysanthemum indicum with 35S:CiHsf10 reduced reactive oxygen species (ROS) accumulation under low-temperature stress, which may contribute to enhanced cold tolerance. Full article

Expansins are essential regulators of plant cell wall loosening, yet their roles in eggplant (Solanum melongena L.) remain poorly understood. This study performed a genome-wide analysis and identified 26 SmEXP genes, categorized into five evolutionary groups. All SmEXP proteins harbor characteristic DPBB_1 and Expansin_C domains. These genes are unevenly distributed across 10 chromosomes out of the 12 eggplant chromosomes, with Chromosome 8 identified as a major distribution hotspot. Synteny and selection pressure analyses suggest that segmental duplications and strong purifying selection have driven the family’s evolution. Promoter analysis revealed various cis-acting elements associated with light, phytohormones, and abiotic stress. Transcriptomic profiling showed that 14 SmEXP genes were significantly upregulated during the rapid fruit expansion phase (14 DAP), indicating their crucial role in fruit morphogenesis. Furthermore, some specific members (SmEXP1, 4, 10, and 13) exhibited distinct upregulation under heat stress (38 °C and 43 °C), suggesting involvement in thermotolerance. These findings identify key expansin genes controlling eggplant development and stress response, providing targets for genetic improvement. Full article

Wheeled multifunctional motorized crossing frames represent a new type of crossing equipment for high-voltage transmission line construction. The initial design is too conservative, having a large safety margin and high material redundancy. Therefore, it is necessary to study a lightweight design version. However, as the structure constitutes an assembly consisting of multiple components, it also exhibits relatively high complexity. In a lightweight design, optimizing multi-component and multi-size parameters can lead to structural interference and separation, seriously affecting the smooth progress of design optimization. Therefore, an optimization design method of a multi-parameter complex assembly structure is proposed to solve this problem. Firstly, the typical stress conditions of the wheeled multifunctional motorized crossing frame were analyzed using its structural model. Then, a finite element model of the beam was established in ANSYS 2021 R1 Workbench, and the mechanical characteristics were analyzed. The results show that the arm support is the key load-bearing component and has significant optimization potential. Subsequently, functional mapping relationships were established among the 14 dimension parameters of the arm support, reducing the number of design variables to six and successfully avoiding component separation or interference during optimization. Through global sensitivity analysis, the height, thickness, and length of the arm body were screened out as the core optimization parameters from six initial design variables. Then, 29 groups of sample points were generated via central composite design (CCD), and a response surface model reflecting the relationships among the arm body’s dimensional parameters, total mass, maximum stress, and maximum deformation was established using the Kriging method. Leave-one-out cross-validation (LOOCV) was performed, and the coefficients of determination (R²) for model fitting were all higher than 0.995, indicating extremely high prediction accuracy. Taking mass and deformation minimization as the optimization objectives, the MOGA algorithm was adopted to perform multi-objective optimization and determine the optimal engineering parameters. Simulation verification was conducted on the optimized arm support, and an eigenvalue buckling analysis was performed simultaneously to verify structural stability. Finally, the proposed optimization method was experimentally verified through mechanical performance tests of the full-scale prototype under symmetric and eccentric loads. The results show that the mass of the optimized arm support is reduced from 217.73 kg to 189.8 kg, with a weight reduction rate of 12.8%. Under an eccentric load of 70,000 N, the maximum deformation of the arm support is 8.9763 mm, the maximum equivalent stress is 314.86 MPa, and the buckling load factor is 6.08, all of which meet the requirements for structural stiffness, strength, and buckling stability. The maximum error between the experimental and finite element results is only 4.64%, verifying the accuracy and reliability of the proposed method. The proposed optimization methodology, validated on a wheeled multifunctional motorized crossing frame, serves as a transferable paradigm for the lightweight design of complex assemblies with coupled dimensional constraints, thereby offering a general reference for the structural optimization of multi-component transmission line equipment, construction machinery, and other multi-component engineering systems. Full article

Beckwith–Wiedemann syndrome (BWS) is an overgrowth disorder caused by genetic and epigenetic alterations at chromosome 11p15.5. Increasing evidence suggests that imprinting defects may be accompanied by broader epigenomic perturbations affecting repetitive elements such as human endogenous retroviruses (HERVs). We quantified the transcriptional levels of the HERV-H, HERV-K, and HERV-W-pol genes, the HERV-derived env genes, Syncytin-1 (SYN1) and Syncytin-2 (SYN2), and the epigenetic regulators, TRIM28 and SETDB1, in whole blood from children and adolescents with BWS, stratified by molecular subtype (ICR2 loss of methylation, n = 14; UPD(11)pat, n = 10), and compared with age-matched healthy controls using quantitative real-time PCR. The BWS samples showed significantly increased transcription of HERV-H and HERV-K relative to controls, whereas HERV-W was unchanged. The SYN1 transcripts were significantly higher in UPD(11)pat compared with controls, while SYN2 did not differ between groups. TRIM28 and SETDB1 were significantly overexpressed in BWS, irrespective of molecular subtype, and no significant differences were observed between ICR2 and UPD(11)pat for HERV-H, HERV-K, HERV-W, TRIM28, or SETDB1. These findings indicate selective dysregulation of endogenous retroelements and key repressors in BWS, consistent with epigenetic alterations extending beyond canonical imprinted loci. Full article

Granitic soils in the Highlands support the cultivation of Arabica coffee in northern Thailand; however, their geochemical and radiological properties are inadequately defined. This study examined major oxides, trace elements, natural radionuclides, and extractable phosphorus in granitic-derived coffee soils from the Agricultural Innovation Research, Integration, Demonstration, and Training Center (AIRID) in Chiang Mai. Twenty soil samples were obtained from 10 locations at two depth intervals (0–30 cm and 30–60 cm). Major and trace elements were analyzed via X-ray fluorescence (XRF), natural radionuclides were analyzed through high-purity germanium (HPGe) gamma spectrometry, and extractable phosphorus was determined using the Bray II method. The soils demonstrate remarkably high ⁴⁰K activity concentrations (1.2–1.9 kBq kg⁻¹) and increased K₂O contents (4.9–7.8 wt%), about three to five times more than worldwide soil averages according to Reimann & de Caritat, indicating enrichment from potassium-rich granitic rocks. Major oxide compositions suggest extensive tropical weathering, characterized by elevated SiO₂ (>60 wt%) and Al₂O₃ (>14 wt%), alongside significant depletion of CaO and MgO (<1 wt%). In topsoil, Bray II–extractable phosphorus constitutes 10–25% of total phosphorus and has a robust positive connection with P₂O₅ (R² = 0.95, p < 0.001), signifying surface accumulation and restricted vertical mobility. Multivariate analysis indicates lithogenic grouping of trace elements with negligible vertical redistribution. These findings establish a geochemical and radiological baseline for highland coffee soils in northern Thailand, with implications for soil fertility assessment, soil–plant transfer research, and evaluations of natural radioactive exposure related to coffee production. Full article

Zinc finger proteins (ZFPs) are a diverse group of plant transcription factors essential for regulating development, signaling, and stress responses. In this study, we performed a genome-wide identification and integrative analysis of 140 C3H-type zinc finger transcription factor genes in the soybean genome, exhibiting an uneven distribution across all 20 chromosomes. These C3H-ZFPs contained one (37), two (58), three (19), four (7), five (17), or six (2) C3H domains and were classified into 14 subsets based on their domain architecture. All C3H genes encoding proteins harbored the conserved C3H-ZFP domain and displayed various physicochemical characteristics. Phylogenetic analysis grouped them into 10 clades, closely related to other species like Arabidopsis, rice and alfalfa. Promoter analysis revealed cis-elements associated with stress response (~39.1%), light response (~37.3%), phytohormones (~18.5%), and development (~4.97%). Duplication analysis revealed 78 pairs of segmental and eight tandem duplication events, with purifying selection indicated by Ka/Ks (nonsynonymous/synonymous) ratios, indicating that these C3H-ZFP duplicates were largely maintained under purifying selection. A total of 388 miRNAs from 196 gene families were predicted to target 140 C3H-ZFP genes, with most enriched miRNAs targeting C3H-ZFP genes, including the miR156, miR395, and miR396 families. Transcription factor binding sites for MYB, AP2, MIKC_MADS, BBR-BPC, ERF, C2H2, and Dof were found upstream of most C3H-ZFP genes. RNA-Seq and qRT-PCR analyses showed tissue-specific expression and stress-responsive expression patterns, with several C3H-ZFP genes, especially GmC3H1, GmC3H63, GmC3H124, and GmC3H127, being significantly upregulated under abiotic stress conditions. Together, these results provide a comprehensive overview of soybean C3H-ZFP genes and identify promising candidates for future functional studies on development and abiotic stress adaptation. Full article

Background: Pregnant adolescents are at higher risk of adverse birth outcomes. Tailoring antenatal care (ANC) to adolescents’ unique needs may be a way to reduce adverse maternal and child outcomes within this population. This systematic review aimed to evaluate ANC services for pregnant adolescents and their impact on maternal and infant outcomes. Methods: Two reviewers independently searched five electronic databases (September 2024) to evaluate existing ANC services that are tailored to adolescents and the impact they have on maternal and infant outcomes. Studies were assessed for quality using the NICE quality appraisal tool and a narrative synthesis was carried out to present the findings. In addition, a survey was disseminated through the Global Adolescent Nutrition Network (GANN) to gain further insights into stakeholder views and experiences of tailored ANC for adolescents. Results: 11,236 articles were reviewed, with 14 studies included for analysis. Interventions as part of ANC for pregnant adolescents included micronutrient supplementation, supplementary feeding, community-based delivery, group-delivery, tailored nutrition education, and additional support and counselling. Outcomes such as birthweight, preterm birth, and gestational age were reported, with most studies (11/14) demonstrating positive effects. Of 103 survey responses, 100% agreed that ANC for pregnant adolescents need to be delivered in a youth-friendly manner, and 57% indicated that providing both youth-friendly delivery and additional support are crucial. Inclusive and supportive care, tailored educational support, tailored nutrition care, and mental health support were most commonly mentioned as key components for tailored ANC. Conclusions: The systematic review and survey data concur in identifying key elements of adolescent-tailored ANC. Some of these have already been shown to be effective; however, due to the high heterogeneity of the study designs, a stronger evidence-base is needed. Specific elements of future ANC packages for pregnant adolescents might include group ANC delivery, community-based services, increased confidentiality measures, mental health support and counselling, health education, and nutrition care tailored to adolescents’ physiological and emotional needs. Full article

To reveal the evolution of the North China Craton (NCC) and the breakup process of the Columbia supercontinent, this study conducted zircon geochronology and garnet mineralogical analyses on kimberlites from the Bayan Obo area, on the northern margin of the NCC. Zircon U-Pb dating yielded four groups of concordant ages: 2505 ± 46 Ma, 2210 ± 57 Ma, 1928 ± 58 Ma, and 1455 ± 88 Ma. Among these, 1455 ± 88 Ma represents the formation age of the kimberlite, corresponding to a regional extensional tectonic setting. The other three groups are xenocrystic zircon ages, recording the formation of the Archean basement of the NCC, extensional magmatic activity in the middle Paleoproterozoic, and collisional metamorphic events in the late Paleoproterozoic, respectively. The major element characteristics of the garnets indicate they are granulite-facies crust-derived garnets (G4 type), formed under temperature and pressure conditions of 791 ± 50–876 ± 50 °C and 14 ± 3.0 kbar. This corresponds to a mantle heat flow value of approximately 60 ± 5 mW/m², suggesting an unstable state of the lithosphere in the study area. Combined with the regional geological background, the depositional age of the Bilute Formation in Bayan Obo is determined to be between 1455 and 1524 Ma. The emplacement of kimberlite is related to extensional rifting driven by the breakup of the Columbia supercontinent, and garnets hosted in kimberlite record the crustal extension and mantle magma underplating during the rift-spreading stage of this period. This study provides key petrological and chronological evidence for the tectonic evolution of the northern margin of the NCC and the breakup of the Columbia supercontinent. Full article

This study aimed to evaluate the potential of branches of black chokeberry, sea buckthorn, and black currant as raw materials for the development of pharmacologically active compounds, primarily oligomeric proanthocyanidins (OPCs), as they exhibit a broad spectrum of biological activities, including antioxidant, antimicrobial, anti-inflammatory, anticancer, etc. Branch biomass collected in spring and autumn of 2023–2025 was analyzed for its functional group profile and used for the isolation of OPCs with ethanol, an ethanol–water mixture (1:1, v/v), and an ethanol–acetone–water mixture (4:1:5, v/v/v). The highest yield of OPCs (up to 14% of DB) was achieved using the ethanol–acetone–water solvent mixture. Using LC-MS/MS, the OPC composition was analyzed and found to consist of dimers (m/z 577), trimers (m/z 865), and tetramers (m/z 1153). The maximum OPC content was observed in autumn samples. Mechanical pretreatment enhanced OPC accessibility by disrupting cell walls and increasing particle surface, facilitating release from the matrix and yielding up to 1.2-fold more OPCs than from untreated biomass. Quantification of 22 elements in the biomass by ICP-MS revealed low levels of toxic metals along with the presence of nutritionally relevant elements. Therefore, from a chemical safety perspective, biomass can be considered suitable for use as a source of OPCs. Full article

Background/Objectives: Dental caries remains one of the most prevalent chronic diseases worldwide, making enamel remineralization a key objective in minimally invasive dentistry. This in vitro study compared the remineralization efficacy of five therapeutic toothpastes containing fluoride, NovaMin, CPP-ACP, nano-hydroxyapatite, arginine, and xylitol. Methods: Sixty enamel specimens were prepared from extracted human posterior teeth and artificially demineralized. Samples were randomly allocated into six groups (n = 10): one negative control (C1) stored in artificial saliva and five treatment groups (P1–P5). A 28-day remineralization protocol with twice-daily applications was performed. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used to assess surface morphology and elemental composition (Ca, P, F, Na, O, Ca/P ratio) at days 1, 14, and 28. Vickers microhardness testing was used to evaluate changes in mechanical properties. Statistical analysis included one-way ANOVA, repeated measures ANOVA, Tukey’s post hoc test, and Kruskal–Wallis where appropriate (α = 0.05). Results: All therapeutic toothpastes produced some increase in mineral content compared to the demineralized control. At day 28, significant intergroup differences were observed for calcium, phosphorus, and fluoride (p < 0.001). The arginine–fluoride formulation (P4) and the NovaMin-based formulation (P3) showed the most consistent increases in Ca and P, with SEM revealing the formation of a continuous, compact surface layer and marked reduction in prismatic porosities. Fluoride-containing toothpastes (P1, P3, P4) showed significant fluoride incorporation (p < 0.001 vs. control). The nano-hydroxyapatite/xylitol prototype (P5) produced a delayed but progressive increase in Ca and P, with partial filling of prismatic spaces. The CPP-ACP-based toothpaste (P2) led to limited changes, with only slight differences vs. control at day 28. Vickers microhardness values increased significantly in groups P1, P3, P4, and P5 (p < 0.05), in agreement with the higher mineral levels found in these samples. Conclusions: Under the present in vitro conditions, toothpastes containing fluoride in combination with NovaMin or arginine, as well as nano-hydroxyapatite/xylitol, demonstrated the highest remineralization potential under the present in vitro conditions, both chemically and mechanically. Xylitol-based formulations without a direct mineral supply showed limited effects. The pH and active composition of the toothpaste strongly influenced enamel remineralization outcomes. Full article

The Dof (DNA binding with one finger) transcription factor family is a plant-specific group of transcription factors that play critical roles in plant growth and development, stress response, and the regulation of secondary metabolism. Prunella vulgaris (P. vulgaris) has attracted considerable attention due to its medicinal value, with rosmarinic acid being one of its key bioactive components. However, the systematic identification of the Dof transcription factor family in P. vulgaris and its regulatory role in rosmarinic acid biosynthesis remains poorly understood. In this study, based on the whole-genome data of P. vulgaris, we identified 48 Dof transcription factor genes distributed across 14 chromosomes using bioinformatics approaches. Physicochemical analysis revealed that the encoded proteins have molecular weights ranging from 15,482.44 to 55,875.53 Da, amino acid lengths between 142 and 509, and theoretical isoelectric points from 4.84 to 10.2. All proteins were predicted to be hydrophilic and localized in the nucleus. Phylogenetic analysis classified them into four subfamilies, and multiple sequence alignment confirmed that all members contain a conserved C2-C2-type zinc finger domain. Analysis of cis-regulatory elements in the promoter regions identified numerous elements related to light responsiveness, hormone response, and development. Transcriptomic expression profiling demonstrated distinct tissue-specific expression patterns of Dof genes, with some showing high expression in spikes and seeds. Correlation analysis between gene expression and rosmarinic acid content identified three candidate genes potentially involved in the regulation of rosmarinic acid biosynthesis, which were further validated by RT-qPCR. Moreover, protein–protein interaction network predictions indicated 242 interactions among 23 Dof proteins. This study provides the first systematic identification of the Dof transcription factor family in P. vulgaris, offering important insights into the transcriptional regulation of rosmarinic acid biosynthesis and presenting potential genetic targets for enhancing rosmarinic acid production through genetic engineering. Full article

The six platinum group elements (PGE) are among the rarest elements in the upper continental crust of the earth. Higher values of PGE have been detected in the upper mantle and in chondrite meteorites. The PGE are siderophile and chalcophile elements and are divided into the following: (1) the Ir subgroup (IPGE) = Os, Ir, and Ru and (2) the Pd subgroup (PPGE) = Rh, Pt, and Pd. The IPGE are more refractory and less chalcophile than the PPGE. High concentrations of PGE led, in rare cases, to the formation of mineral deposits. The PGE are carried in discrete phases, the platinum group minerals (PGM), and are included as trace elements into the structure of base metal sulphides (BM), such as pentlandite, chalcopyrite, pyrite, and pyrrhotite. Similarly to PGE, the PGM are also divided into two main groups, i.e., IPGM composed of Os, Ir, and Ru and PPGM containing Rh, Pt, and Pd. The PGM occur both in mafic and ultramafic rocks and are mainly hosted in stratiform reefs, sulphide-rich lenses, and placer deposits. Presently, there are only 169 valid PGM that represent about 2.7% of all 6176 minerals discovered so far. However, 496 PGM are listed among the valid species that have not yet been officially accepted, while a further 641 are considered as invalid or discredited species. The main reason for the incomplete characterization of PGM resides in their mode of occurrence, i.e., as grains in composite aggregates of a few microns in size, which makes it difficult to determine their crystallography. Among the PGM officially accepted by the IMA, only 13 (8%) were discovered before 1958, the year when the IMA was established. The highest number of PGM was discovered between 1970 and 1979, and 99 PGM have been accepted from 1980 until now. Of the 169 PGM accepted by the IMA, 44% are named in honour of a person, typically a scientist or geologist, and 31% are named after their discovery localities. The nomenclature of 25% of the PGM is based on their chemical composition and/or their physical properties. PGM have been discovered in 25 countries throughout the world, with 64 from Russia, 17 from Canada and South Africa (each), 15 from China, 12 from the USA, 8 from Brazil, 6 from Japan, 5 from Congo, 3 from Finland and Germany (each), 2 from the Dominican Republic, Greenland, Malaysia, and Papua New Guinea each, and only 1 from Argentine, Australia, Bulgaria, Colombia, Czech Republic, England, Ethiopia, Guyana, Mexico, Serbia, and Tanzania each. Most PGM phases contain Pd (82 phases, 48% of all accepted PGM), followed, in decreasing order of abundances, by those of Pt 35 phases (21%), Rh 23 phases (14%), Ir 18 phases (11%), Ru 7 phases (4%), and Os 4 phases (2%). The six PGE forming the PGM are bonded to other elements such as Fe, Ni, Cu, S, As, Te, Bi, Sb, Se, Sn, Hg, Ag, Zn, Si, Pb, Ge, In, Mo, and O. Thirty-two percent of the 169 valid PGM crystallize in the cubic system, 17% are orthorhombic, 16% hexagonal, 14% tetragonal, 11% trigonal, 3% monoclinic, and only 1% triclinic. Some PGM are members of a solid-solution series, which may be complete or contain a miscibility gap, providing information concerning the chemical and physical environment in which the mineral was formed. The refractory IPGM precipitate principally in primitive, high-temperature, mantle-hosted rocks such as podiform and layered chromitites. Being more chalcophile, PPGE are preferentially collected and concentrated in an immiscible sulphide liquid, and, under appropriate conditions, the PPGM can precipitate in a thermal range of about 900–300 °C in the presence of fluids and a progressive increase of oxygen fugacity (fO₂). Thus, a great number of Pt and Pd minerals have been described in Ni-Cu sulphide deposits. Two main genetic models have been proposed for the formation of PGM nuggets: (1) Detrital PGM represent magmatic grains that were mechanically liberated from their primary source by weathering and erosion with or without minor alteration processes, and (2) PGM reprecipitated in the supergene environment through a complex process that comprises solubility, the leaching of PGE from the primary PGM, and variation in Eh-pH and microbial activity. These two models do not exclude each other, and alluvial deposits may contain contributions from both processes. Full article

Our main goal was to determine whether the accumulation of Cd and Cu is harmful for L. perenne or whether this plant can be used in the bioremediation, e.g., of wastewaters or contaminated soils. The IC50 values (concentration at which the tested parameter is inhibited to 50% against the control) for root and shoot inhibition after 14 days showed that Cu, as an essential element for plants, was more toxic than Cd. The translocation factor (TF), which refers to metal transport from the root to the shoot, did not exceed values of 0.228 and 0.353 for Cd and Cu, respectively, indicating their accumulation mostly in the roots rather than in the shoots. The protein thiol (-SH) groups as a parameter of the increased level of reactive oxygen species did not confirm the significantly higher level of oxidative stress for Cu, which is a redox-active cation. We confirmed a statistically significant positive correlation between -SH groups and chlorophyll a (r = 0.79; p < 0.05) and chlorophyll b (r = 0.84; p < 0.01) in the presence of Cd. We concluded that bioaccumulation of the tested metals occurred mostly in the roots, and the photosynthetic pigment content in the shoots was not significantly impaired by the increased presence of Cd or Cu in the shoots. Therefore, we suggest L. perenne as a suitable candidate for the phytomining or phytoextraction of metals, mostly from wastewater, in cooperation with other plant hyperaccumulators. Full article