Search Results (68)

Machine learning interatomic potentials (MLIPs) are typically developed for globally ordered homogeneous systems (GOHomS), which exhibit only minor local deviations from equilibrium configurations. Consequently, most existing MLIPs trained on GOHomS often perform inadequately when applied to locally ordered heterogeneous systems (LOHetS), e.g., substitutional alloying elements in multicomponent alloys. To describe doping alloy systems, we develop a fine-tuned MLIP based on the MACE foundation model, specifically tailored for Mo-based dilute alloys containing one or two out of 20 substitutional elements: Cr, Fe, Mn, Nb, Re, Ta, Ti, V, W, Y, Zr, Al, Zn, Cu, Ag, Au, Hg, Co, Ni, and Hf. The model is built on more than 7000 equilibrium and non-equilibrium structures derived from first-principles density functional theory (DFT) calculations. The optimized large-scale fine-tuned model attains state-of-the-art accuracy, with a mean absolute error (MAE) and root-mean-square error (RMSE) of 2.27 meV/atom and 3.79 meV/atom for energy predictions, and 13.83 meV/Å and 24.26 meV/Å for force predictions, respectively. Systematic evaluation under different data-splitting protocols shows that unknown element extrapolation remains challenging under strict dopant hold-out, whereas substantially improved accuracy can be achieved in partial-exposure transfer settings. The fine-tuned models reduce the MAE by approximately 7–10 times compared to models trained from scratch, and by 10–20 times relative to zero-shot foundation models. This performance gain remains consistent across varying dataset sizes (equilibrium vs. non-equilibrium structures) and model scales. Our work illustrates the efficacy of transfer learning from globally ordered homogeneous systems to locally ordered heterogeneous multicomponent alloy environments. However, direct transfer to entirely unknown elements remains challenging, especially when proxy embeddings are employed without fine-tuning. Thus, to achieve high accuracy without incurring additional cost, it is essential to include unknown elements in the training dataset while minimizing the number of configurations containing known elements. Moreover, the current findings are primarily validated for dilute Mo-based alloy systems. Extending this approach to more compositionally complex alloy spaces may necessitate additional data and further fine-tuning. Full article

Background: Frail patients undergoing hip and knee revision surgery represent a major anesthetic challenge because of advanced age and multiple comorbidities. Continuous spinal anesthesia (CSA) with titrated low-dose levobupivacaine may offer a potentially useful alternative to general anesthesia or single-shot spinal anesthesia in this high-risk population. Methods: A retrospective review was conducted of ASA II-III patients who underwent complex hip and knee revision surgeries between February and October 2024 under CSA. The technique was performed using a 25-gauge spinal catheter with incremental boluses of 0.25% levobupivacaine (2.5 mg). Hemodynamic parameters, including mean arterial pressure (MAP), stroke volume index (SVI), and cardiac index (CI), were continuously monitored using the EV1000 hemodynamic monitoring system. Postoperative complications were recorded. Results: 37 high-risk patients were included in the study. Catheter placement was successful in all patients, with no conversions to general anesthesia. MAP decreased by a mean of 14.6% after boluses (p < 0.05); 9 patients (24.3%) experienced reductions ≥ 20%, but all remained >65 mmHg and responded to fluid therapy. CI and SVI decreased by 10.1% and 10.5%, respectively (p < 0.05), without clinical instability. No major complications (neurological injury, infection, post-dural puncture headache) were observed. Conclusions: In this retrospective single-center experience, CSA with titrated low-dose levobupivacaine was feasible and associated with stable hemodynamic profiles and a low rate of complications in frail patients undergoing complex lower-limb revision surgery. However, given the absence of a control group and the limited sample size, these findings should be interpreted cautiously. Further prospective comparative studies are needed to better define the role of CSA in high-risk orthopedic patients. Full article

Background: Uterus transplantation (UTx) is an emerging treatment for absolute uterine factor infertility. However, the use of deceased donors is limited, and donation after circulatory death (DCD) has not yet been utilized. Ischemic injury remains a major barrier, particularly compared with living donor procedures. Hypothermic oxygenated perfusion (HOPE), which has shown protective effects in heart, liver, and kidney transplantation, may offer similar benefits for uterine grafts. Methods: We report the first series applying HOPE to human uteri to improve preservation and enable metabolic injury assessment during perfusion. Six uteri (3 DBD, 3 DCD; median donor age 53 years) underwent 8 h of HOPE following procurement, while paired tissue controls were preserved using static cold storage (SCS). Perfusion was delivered using a pressure-controlled system (15 mmHg, 10 ± 1 °C, VitaSmart^®). Perfusate and tissue samples were analyzed for mitochondrial injury, inflammation, and transcriptional responses. Results: HOPE maintained stable flows (70–150 mL/min), delivered high oxygen levels (pO₂ ≈ 1000 hPa), and increased tissue ATP levels. Stratification based on perfusate flavin mononucleotide (FMN) release identified grafts with greater Complex I/II injury. HOPE was associated with lower levels of mitochondrial injury markers and inflammatory signals, preserved tissue architecture, and promoted gene expression patterns consistent with metabolic recovery compared with paired SCS tissue controls. Conclusions: These findings suggest that HOPE may serve as a preservation approach that enables metabolic and ischemic injury assessment and may facilitate broader use of deceased donor uteri for transplantation. Full article

Cold-mercury gilding uses mercury as an adhesive to bond gold foil onto the surface of copper and silver artifacts. This technique and mercury gilding (fire gilding) both belong to the Au-Hg system and are closely related in technology. Clarifying the technical differences between them is of great significance for revealing the developmental sequence of ancient gilding technologies. On the basis of reconstructing traditional fire gilding, simulated cold-mercury-gilded samples were successfully prepared using experimental archeological methods, and multi-scale characterization was performed using SEM-EDS, XRD, and XPS. The results show that the surface of cold-mercury-gilded samples displays a micromorphology of folded and overlapped gold foil accompanied by locally dense particle aggregation. The cross-section of the gold layer exhibits a multilayer stacked structure, in which mercury is enriched at the gold layer/substrate interface and forms an AuHgCu/Ag diffusion layer. Room-temperature-stable Au-Hg and Ag-Hg phases such as Au₂Hg and AgHg are present in the gold layer, reflecting complex phase transformation behavior of the Au-Hg/Ag-Hg system at room temperature. During cold-mercury gilding, liquid mercury first adheres to the gold foil, and then interdiffusion and phase reactions occur between mercury, gold, and copper/silver atoms at room temperature. Intermetallic compounds and diffusion layers formed at the interface achieve firm bonding between the gold layer and the substrate. Both cold-mercury gilding and mercury gilding achieve metallurgical bonding through atomic interdiffusion. However, affected by differences in the initial state of mercury and operating temperature, the phase transformation and atomic diffusion behaviors of the system differ significantly, which are ultimately reflected in the cross-sectional structure of the gold layer, the composition of the interfacial diffusion layer, and the types of phases. Therefore, mercury-gilded artifacts show superior gold layer durability and bonding strength with the substrate compared with cold-mercury-gilded artifacts. Both techniques pioneered the application of mercury in metallic gilding and represent important innovations in ancient surface decoration technology. Full article

Background: Intraoperative high-volume diuresis is a common but under-recognized phenomenon during off-pump coronary artery bypass grafting (OPCABG). Its clinical correlates and implications for perioperative management remain incompletely characterized. Methods: This single-center retrospective cohort study included 1274 adults undergoing elective OPCABG between January and August 2025. High-volume diuresis was defined as urine output ≥ 5 mL·kg⁻¹·h⁻¹. Multivariable logistic regression was used to identify factors independently associated with intraoperative high-volume diuresis. Model discrimination was assessed using the area under the receiver operating characteristic curve (AUC). Results: High-volume diuresis occurred in 39.6% of patients. Older age, hypertension and greater intraoperative fluid infusion were independently associated with high-volume diuresis, whereas preoperative diuretic and greater cumulative exposure to systolic blood pressure < 100 mmHg were inversely associated with diuresis. The multivariable model demonstrated acceptable discrimination (AUC = 0.756). Postoperative outcomes, including acute kidney injury, duration of mechanical ventilation, intensive care unit stay, and hospital length of stay, did not differ between groups. Conclusions: Intraoperative high-volume diuresis during OPCABG reflects complex physiological and hemodynamic responses and can be anticipated based on preoperative and intraoperative factors. These findings support a more individualized interpretation of urine output and perioperative management strategies in OPCABG. Full article

Groundwater in Al-Madinah Al-Munawwarah faces considerable challenges from high salinity, elevated TDS, and nitrate contamination, primarily due to urbanization and industrial activities, making ongoing monitoring and management essential for its sustainable use in both drinking water and agriculture. The assessment of groundwater quality was conducted on 44 wells tapping two major aquifers (basaltic and alluvial) in the region, utilizing various geochemical techniques, including ICP-MS, FAAS, and XRF, to evaluate hydrochemical characteristics and identify the primary controlling factors. Key physicochemical parameters, including total dissolved solids (TDSs), electrical conductivity (EC), pH, total hardness (TH), and major ion concentrations, were evaluated. The results indicate that several parameters exceed permissible limits established by Gulf and international standards, reflecting highly saline conditions that could adversely affect drinking water safety and agricultural practices. Elevated nitrate levels and other contaminants indicate a combination of geological processes, including mineral leaching, and anthropogenic activities, such as agricultural runoff. Correlations among various ions reveal complex interactions driven by both natural and human factors. High nitrate and potassium concentrations, particularly in the alluvial aquifer, combined with weak correlations with geogenic ions, indicate anthropogenic inputs. Heavy metals in groundwater were classified into two groups: those within permissible limits (Ag, Ba, Be, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Sb, and U) and those exceeding recommended limits (Zn, Al, As, Se, and Tl). Elevated metal concentrations are primarily attributed to water–rock interactions and the fertilizer use in surrounding agricultural areas. These findings highlight the urgent need for continuous monitoring and proactive groundwater to ensure sustainable and safe use of water resources. Full article

The elemental composition of the vitreous humor may reflect physiological and pathological processes occurring in the eye. The objective of this study was to provide a complex multielemental analysis of human vitreous humor. Vitreous humor samples (n = 57) were collected post-mortem during autopsies. Inductively coupled plasma mass spectrometry (ICP-MS) was employed to quantify micro-, trace-, ultra-trace, and toxic elements. The study showed the occurrence of elements at the ppm (Na, K, P, Ca, Mg), ppb (Al, Rb, Zn, Fe, Sr, Cu), and ppt (Ce, La, Nd, Tb) levels. Hierarchical clustering using Ward’s method and k-means analysis revealed four distinct clusters, including two major clusters representing the baseline macro- and microelement profile characteristic for the studied population. Correlations between elements revealed statistically significant (p < 0.05) positive and negative correlations between elements with (I) chemical similarity Ce-La, Cs-Rb, Rb-K, Ca-P, Zn-Cu, and Cs-K; (II) a possible common environmental origin, Cd-P, and Rb-P; (III) involvement in similar biological processes as K-P; and (iv) a common geochemical origin and similar biological functions, i.e., Se-Zn. The study identified several quantitative trends in the demographic and medical characteristics of the participants. Alcohol users had significantly higher Zn concentrations than non-alcohol users; women had significantly higher Ca concentrations than men; higher BMI correlated positively with Cs and negatively with Be and Cr levels; and Cu, Sb, Cd, Se, and Ca concentrations increased with age. The presence of several toxic and potentially toxic elements was identified in the vitreous body: Al (>10 ppb); Cd, Cr, Pb, Ni, Mn; and Ba (<10 ppb); As, Hg, Sb, Tl, Bi, Be (<1 ppb). The study showed that, within a given geographic region, the accumulation profiles of toxic metals are quite homogeneous, indicating common sources of exposure. Full article

Kutná Hora ore district, one of the largest historical silver deposits in Central Europe, consists of nine major lodes with Pb-Zn-Ag mineralization hosted by high-grade basement rocks of the Kutná Hora Crystalline Complex in central part of the Bohemian Massif. We conducted a detailed electron-microprobe study of a previously unknown ore mineralization from the uppermost level of the Muzejní důl mine, which is a medieval mine located within the Ag-richest Oselské pásmo Lode, in the southern part of the ore district. An unusual nature of this ore mineralization, which originated during three respective stages, was found. The early stage comprises the hypogene mineralization commonly occurring in the southern part of the district, composed of pyrite, arsenopyrite, Fe,Mn-enriched sphalerite, galena, and (keno)argentotetrahedrite-(Fe) hosted in quartz and siderite-rhodochrosite gangue. The second stage was characterized by the corrosion of early vein fill followed by the crystallization of a specific suite of ore minerals anomalously enriched in Ag, Cu, Zn, Cd, As, and Sb, including galena, Cd-enriched and Fe-poor sphalerite, greenockite, bornite, Ag,As,Sb,Mn-bearing chalcopyrite, silver, gold, stephanite, As,Cu-bearing pyrargyrite, Ag-Cu- and Sb-As-bearing polybasite-pearceite group minerals and a suite of tetrahedrite-group minerals, the latter showing wide variations in Ag-Cu, Sb-As, and Fe-Zn-Cd contents. The origin of the second-stage mineralization is interpreted in hydrothermal remobilization of ore metals and metaloids from the early ore mineralization, which was mediated by surficial fluids characterized by elevated redox potential. The third stage comprises acanthite and probably also Ag-Cu minerals (stromeyerite, jalpaite, and mckinstryite), Cu-S phases (covellite, spionkopite, geerite), and an Ag-Cu-Hg mineralization. This late mineralization was likely related to the pre-Cretaceous weathering of the apical part of the ore deposit and to the associated supergene enrichment of deeper parts of the ore zone by descending Ag,Cu-bearing waters. 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

Silk Lutein (SL), a novel protein-bound lutein complex derived from Bombyx mori cocoons, offers an intriguing alternative to traditional sources. This study aimed to establish the complete toxicological profile of SL. Evaluations of the acute oral toxicity of SL (LD₅₀ > 2000 mg/kg body weight (BW)) were conducted in female Wistar rats and ICR mice. In the chronic toxicity trial, male and female Wistar rats were administered daily oral dosages of SL (5, 25, 50 mg/kg BW) for a duration of six months. The results indicated a robust safety profile for SL, with no treatment-related adverse effects detected. Apart from demonstrating its foundational safety, this study found that prolonged SL administration possessed significant, beneficial bioactive properties. Following four months of treatment, both male and female Wistar rats administered SL exhibited a significant hypotensive effect, maintaining their systolic blood pressure at approximately 120 mmHg and thereby averting the age-related hypertension observed in control subjects. Additionally, SL significantly reduced serum triglyceride levels in both sexes. The findings of this study confirm SL’s potential as a multipurpose nutraceutical by demonstrating that it is a safe constituent with a favorable toxicological profile and notable cardiovascular effects. Full article

Intense chemical weathering in tropical environments poses challenges for conventional geochemical exploration, as primary lithological signatures become heavily altered. Stream sediment geochemistry provides a robust alternative for detecting anomalous geochemical patterns under these conditions. In this study, 636 stream sediment samples and 15 rock samples were evaluated using Principal Component Analysis (PCA), Median + 2 Median Absolute Deviation (MAD), and Concentration–Area (C–A) fractal modeling to identify potential anomaly zones. These results were compared with the traditional Mean plus 2 Standard Deviation (SD) approach. The findings indicated that Mean + 2SD offers a conservative threshold but overlooks anomalies in heterogeneous datasets, while Median + 2MAD provides robustness against outliers. The C-A fractal model effectively characterizes low- and high-order anomalies by capturing multiscale variability. Elements such as Au–Ag–Hg–Se–Sb–As form a system indicating low- to intermediate-sulphated epithermal mineralization. Au–Pb points to polymetallic hydrothermal mineralization along intrusive contacts. The southern region is a primary mineralization center controlled by an intrusive–volcanic boundary, whereas the east and west areas exhibit secondary mineralization, characterized by altered lava breccia. The correlation between shallow epithermal and deeper intrusive-related porphyry systems, especially regarding Au–Ag, offers new insights into the metallogenic landscape of the Sunda–Banda arc. Beyond regional significance, this research presents a geostatistical workflow designed to mitigate exploration uncertainty in geochemically complex zones, providing a structured approach applicable to volcanic-arc mineralized provinces worldwide. Full article

Background: Although orbital fractures are common in trauma care, age-specific mechanisms and admission physiology-based risk stratification have not been systematically characterized. This study aimed to identify age–mechanism interaction patterns and develop an admission-based physiological risk score for orbital fracture patients. Methods: This retrospective cohort study analyzed 41,464 adult orbital fracture patients from the National Trauma Data Bank (2018–2020). A three-component physiological risk score was developed using admission vital signs: severe hypotension (<90 mmHg, 2 points), tachycardia (>100 bpm, 1 point), and severe traumatic brain injury (GCS ≤ 8, 1 point). Risk stratification performance was validated against composite adverse outcomes. Results: Distinct age–mechanism patterns emerged: 74.0% of elderly patients (≥65 years) sustained falls, while young adults demonstrated a bimodal distribution with motor vehicle crashes (31.2%) and violence (28.4%). Violence-related injuries occurred in younger patients (40.3 vs. 55.0 years) but had lower injury severity scores (10.0 vs. 14.4) and mortality (2.8% vs. 5.2%) than accidental mechanisms. High-/critical-risk patients (8.4% of the cohort) had 16.2% mortality versus 2.1% in stable patients. Complex facial injuries demonstrated 11-fold higher mortality (7.7% vs. 0.7%). The physiologic risk score achieved AUC 0.79 (95% CI: 0.78–0.80). Conclusions: Age–mechanism interactions revealed distinct bimodal injury patterns in young adults. Admission physiologic parameters effectively identify 8.4% of patients requiring intensive resources, while violence-related injuries paradoxically demonstrate better outcomes than accidental mechanisms. Full article

Introduction: Trace metals can negatively impact biological functions and brain development. Cognitive and neurobehavioral disorders in children are poorly documented in Haut-Katanga Province, an area with significant and multiple exposures to trace metals that can lead to the exacerbation of cognitive and behavioral disorders. Objective: This study aimed to characterize the behavior of schoolchildren linked to their cognitive performance in urban and rural environments. Methods: A cross-sectional pilot study was conducted on 52 schoolchildren aged 6 to 11 (22 from rural areas presumed less exposed to metals and 30 from Lubumbashi, DRC). This study employed NEPSY-II tests, the Strengths and Difficulties Questionnaire (SDQ-Tutor), ENA 2020 software and trace metal spectrometry assays. Statistical tests were carried out with SPSS-20 and Stata-18. Results: Our findings revealed a correlation between children’s malnutrition and low mother’s education. The “total difficulties score” was more prevalent in rural areas (73%) compared to urban settings (37%) p < 0.05), in contrast to the “negative impact of difficulties” (59% versus 57%, p > 0.05). Urban children demonstrated superior cognitive performance, particularly in “facial affect recognition” (8 versus 4, p = 0.013) and “inhibitory control” (6.5 versus 3, p = 0.032). As-U(urine), Cd-B(blood), Hg-B, Mo-U, Ni-U, Pb-U, Pb-B and Sb-U were elevated compared to references. In general, urban areas had higher metal levels than rural areas. Blood and urine metals showed a complex and significant relationship with behavioral difficulties or cognitive performance. Conclusions: The observed behavioral issues, cognitive performance deficits and their association with nutritional deficiencies and trace metal exposure suggest a multifactorial neurodevelopmental origin. These findings highlight the need for further research in the region. Full article

Background and Aims: Severe acute respiratory distress syndrome (ARDS) in patients with long COVID remains associated with extremely high mortality and significant long-term sequelae. Non-invasive ventilatory strategies such as continuous positive airway pressure (CPAP) and high-flow nasal cannula (HFNC) are widely used before endotracheal intubation (ETI). Still, their comparative effectiveness in this population is not well established. Understanding survival outcomes and sequelae can help refine treatment strategies for this high-risk group. This study aimed to evaluate outcomes, sequelae, and treatment strategies in long COVID patients with severe ARDS, focusing on non-invasive ventilatory support before ETI. Materials and Methods: A retrospective cohort analysis was performed using a study comparing severe ARDS patients with and without COVID-19. The inclusion criterion was a Horovitz quotient (PaO₂/FiO₂) < 50 mmHg. Results: The study included a total of 59 patients diagnosed with long COVID-19 ARDS, with a mortality rate of 85%. A significant proportion of the patient population was male, accounting for 75%. The highest survival rate was observed among patients who initially received CPAP support, with a survival rate of 23.08%, in contrast to those treated solely with HFNC or those who alternated between HFNC and CPAP. Among patients who required endotracheal intubation and subsequent mechanical ventilation, survival rates were 40% for those who had previously received CPAP, 10% for those treated with alternating HFNC and CPAP, and 0% for those managed exclusively with HFNC before ETI. Survivors often exhibited sequelae, such as impaired pulmonary function, persistent dyspnea, and diminished physical performance. Conclusions: Patients with long COVID who develop severe ARDS (PaO₂/FiO₂ < 50 mmHg) face exceptionally high ICU mortality, with outcomes determined mainly by age, comorbidities, and profound hypoxemia. Although CPAP showed a trend toward improved survival, the data do not establish superiority and should be regarded as hypothesis-generating. Rather, they highlight the complexity of managing this underrepresented subgroup and underscore the need for larger, multicenter studies with broader inclusion criteria to confirm or refute these preliminary observations. Full article

Ore mining and smelting are often related to environmental pollution. This study provides information about the geochemical features of Technosols at historical mining and metallurgical sites in the Tatra Mountains, southern Poland, evaluating the contents of potentially toxic trace elements (PTTE) and their behaviours in soils, as well as the influence of soil properties on PTTE mobility. Thirteen soil profiles were studied in eight abandoned mining and smelting sites. PTTE concentrations, including rare earth elements (REE), were measured using ICP-MS and ICP-OES. Selected elements (Cu, Zn, Pb, Cd, As, Sb, Ba, Sr, Co, Ni, Mn and Cr) were fractionated using the modified European Community Bureau of Reference (BCR) four-step sequential extraction. Contamination of soils with PTTE was compared against Polish regulatory limits, which were exceeded for Cu, Zn, Pb, Mo, Hg, As, Co, Ni and Ba, with concentrations exceeding limits by 16, 18, 34 and 160 times for Cu, Hg, As and Ba, respectively, in some profiles. Based on geochemical features depending on parent material properties, the soils examined were divided into three groups. Group I Technosols (near-neutral soils developed from Fe/Mn-ore and carbonate-bearing mining waste) were particularly enriched in Co, Ni, Mn and REE. Group II Technosols (acidic soils developed from polymetallic ore-bearing aluminosilicate mining waste) contained elevated concentrations of Cu, Zn, Hg, As, Sb, Bi, Co, Ag, Ba, Sr, U and Th; they contained lower contents of REE than Group I Technosols. Group III Technosols (soils developed in smelting-affected areas and containing metallurgical waste) were rich in Cu, As, Sb, Ba, Hg, Co and Ag and contained the lowest REE contents among the studied soils. Sequential BCR extraction revealed that PTTE mobility varied strongly according to soil group, with higher mobility of Mn, Cu and Zn in acidic polymetallic ore-derived soils (Group II), while carbonate-rich soils (Group I) showed mainly immobile forms. Metallurgical slag-derived soils (Group III) exhibited complex PTTE behaviour controlled by organic matter and Fe/Mn oxides. Soil properties (pH, carbonates and TOC) seem to control PTTE mobility. Full article