Search Results (6,273)

Solid base catalysts hold significant promise for replacing traditional homogeneous bases with green chemical processes. However, the construction of their strong basic sites typically relies on high-temperature calcination, which often leads to the collapse of the carrier structure and high energy consumption. This study proposes a novel “carrier reducibility tuning” strategy, which involves endowing the carrier with intrinsic reducibility to induce the low-temperature decomposition of alkali precursors via a redox pathway, thereby enabling the mild construction of strong basic sites. Low-valence Cr³⁺ was doped into a mesoporous zirconia framework, successfully fabricating an MCZ carrier with a mesostructure and reducible characteristics. Characterization results indicate that a significant redox interaction between the Cr³⁺ in the carrier and the supported KNO₃ occurs at 500 °C. This interaction facilitates the complete conversion of KNO₃ into highly dispersed, strongly basic K₂O species, while Cr³⁺ is predominantly oxidized to Cr⁶⁺. This activation temperature is approximately 300 °C lower than that required for the conventional thermal decomposition pathway and effectively preserves the structural integrity of the material. In the transesterification reaction for synthesizing dimethyl carbonate, the prepared catalyst exhibits superior catalytic activity, significantly outperforming classic solid bases like MgO and other reference catalysts. Full article

Rheology plays an important role in the 3D concrete printing technology, because it directly governs the flowability and shape retention of the material, impacting both the printing process and the final quality of the obtained structure. Local raw materials such as Portland cement, washed sand, and tap water were used for the preparation of 3D-printed concrete mixtures. The solid-state polycarboxylate ether with an anti-foaming agent was used as superplasticizer. The Portland cement was partially replaced (by volume) with a natural zeolite additive in amounts ranging from 0% to 9% in 3D-printed concrete mixtures. A rotational rheometer with coaxial cylinders was used in this research for the determination of rheological characteristics of prepared 3D-printed concrete mixtures. The Herschel–Buckley model was used to approximate experimental flow curves and assess rheological parameters such as yield stress, plastic viscosity, and shear-thinning/thickening index. The additional experiments and calculations, such as water bleeding test and evaluation of the carbon footprint of 3D-printed concrete mixtures, were performed in this work. The replacement of Portland cement with natural zeolite additive positively influenced rheological and stability-related properties of 3D-printed concrete mixtures. Natural zeolite additive consistently reduced water bleeding, enhanced yield stress under increasing shear rates, and lowered plastic viscosity, thereby improving flowability and mixture transportation during the 3D printing process. As the shear-thinning/thickening index remained stable (indicating non-thixotropic behavior in most cases), higher amounts of natural zeolite additive introduced slight thixotropy (especially under decreased shear rates). These changes contributed to better shape retention, layer stability, and the ability to print taller and narrower structures without collapse, making natural zeolite additive suitable for use in the optimized processes of 3D concrete printing. A significant decrease in total carbon footprint (from 3% to 19%) was observed in 3D-printed concrete mixtures with an increase in the mentioned amounts of natural zeolite additive, compared to the mixture without this additive. Full article

The gut immune microenvironment and the liver engage in intricate information exchange via the gut–liver axis. The disruption of these interactions plays a pivotal role in the formation and exacerbation of pathological damage to the liver. The gut immune microenvironment is not an independent layer of the gut barrier; rather, it permeates and regulates all other barrier functions, serving as the core coordinator. Disruption of the immune microenvironment in the gut–liver axis drives progression across the full disease spectrum—from steatosis to hepatitis, fibrosis, and even liver cancer—through the continuous influx of immune-stimulatory signals that overwhelm the liver’s intrinsic immune regulatory mechanisms. Dysfunction of innate immunity components, amplification of inflammatory factors and key cellular signaling pathways, activation of adaptive immune T cells, and systemic effects mediated by liver-derived inflammatory factors collectively form a disordered immune microenvironment. This damages the intestinal barrier and exacerbates liver disease via the gut–liver axis, leading to further intestinal injury, thus establishing a self-reinforcing vicious cycle. Current therapeutic strategies based on modulating the gut–liver axis microenvironment remain limited, yet studies have demonstrated that suppressing gut immune cells, cytokines, and signaling pathways can help delay liver disease progression. Hopefully, future combined, precise, and cutting-edge gut immunotherapies will provide more effective strategies for liver disease treatment. Full article

Background/Objectives: Drug-induced sleep endoscopy (DISE) is used in obstructive sleep apnea (OSA) to visualize dynamic upper airway collapse, but sedation protocols vary widely with no consensus on the optimal agent or technique. This narrative review aims to clarify current sedation strategies for DISE in OSA and their clinical implications. Methods: We systematically searched PubMed, Scopus, Web of Science, and Cochrane Library for English-language publications on DISE sedation (2000–2025). Relevant clinical studies, guidelines, and reviews were included. Data were qualitatively synthesized due to heterogeneity among studies. Results: Sedation approaches in DISE varied considerably. Propofol, dexmedetomidine, and midazolam were the primary agents identified. Propofol provided rapid, titratable sedation but increased airway collapsibility at higher doses; dexmedetomidine produced a more natural sleep-like state with minimal respiratory depression; midazolam was less favored due to prolonged effects. Use of target-controlled infusion (TCI) and pharmacokinetic–pharmacodynamic (PK–PD) models improved control of propofol sedation. Co-sedative adjuncts (e.g., opioids) reduced the required sedative dose but added risk of respiratory depression. Careful titration to the lowest effective dose-often guided by bispectral index (BIS) monitoring—was emphasized to achieve adequate sedation without artifactual airway collapse. No universal DISE sedation protocol was identified. Conclusions: Optimal DISE sedation balances adequate depth with patient safety to ensure reliable findings. Using the minimum effective dose, guided by objective monitoring (e.g., BIS), is recommended. There is a need for standardized sedation protocols and further research (e.g., in obese patients) to resolve current controversies and improve DISE’s utility in OSA management. Full article

We present the case of an 83-year-old woman with a long-standing history of rheumatoid arthritis (RA) who was found collapsed at home. The patient presented with cardiopulmonary arrest and could not be resuscitated. A postmortem examination was performed to determine the cause of death. Postmortem computed tomography (CT) ruled out intracranial hemorrhage but revealed diffuse bilateral pulmonary consolidations and signs of bronchial obstruction. The autopsy revealed severe pulmonary edema and marked right ventricular hypertrophy. Microscopic examination of the lungs demonstrated characteristic features of pulmonary veno-occlusive disease (PVOD), including widespread fibrous intimal thickening and occlusion of small pulmonary veins and venules. Notably, there was no evidence of RA-associated interstitial lung disease (ILD). The direct cause of death was identified as pulmonary edema secondary to PVOD. This case highlights that PVOD can occur in patients with RA as a distinct pathological entity, independent of ILD. This finding is significant as it contrasts with previous reports where PVOD was associated with ILD. Therefore, clinicians should consider PVOD in the differential diagnosis of RA patients who present with unexplained pulmonary hypertension or progressive dyspnea, even in the absence of interstitial lung disease. Full article

KIT-6 samples were prepared at hydrothermal aging temperatures of 60, 100, and 140 °C, and used as templates for nanocasting of zirconium-doped ceria. In nanocast samples, the ordered 3D structure collapsed, leaving behind nanorods with a diameter roughly in concordance with the corresponding KIT-6 template pore diameter. In addition to nanocrystalline ceria, a small amount of cubic zirconia is present in the doped samples, but the formation of a solid solution was confirmed by the decrease in the ceria lattice parameter relative to bulk ceria. The specific surface areas of the nanocast samples decreased with the increase in KIT-6 template aging temperature. Ceria bandgap values were slightly blueshifted in comparison with bulk ceria, which was attributed to quantum confinement. No difference between samples concerning lattice ceria defects has been noted. Conversion curves show apparent three-stage conversion with stagnation at temperatures in the range between 250 °C and 300 °C, which is a consequence of abundant adsorption of toluene below 250 °C and desorption above 250 °C. Slight differences in catalytic activity are only due to a difference in the amount of adsorbed toluene caused by differences in the specific surface area of the samples. Full article

Airway management is central to the care of critically ill patients, yet it remains one of the most challenging interventions in emergency departments and intensive care units. Patients often present with severe physiological instability, limited cardiopulmonary reserve, and high acuity, while clinicians often work under constraints related to time for preparation, equipment availability, trained workforce, monitoring, and access to advanced rescue techniques. These challenges are particularly pronounced in low- and middle-income countries and other resource-limited or austere environments, where the margin for error is narrow and delays or repeated attempts in airway management may rapidly precipitate hypoxemia, hemodynamic collapse, or cardiac arrest. Although contemporary airway guidelines emphasize structured preparation and rescue pathways, many assume resources that are not consistently available in such settings. This narrative review discusses pragmatic, context-adapted strategies for airway management in constrained environments, with emphasis on physiology-first preparation, appropriate oxygenation and induction techniques, simplified rapid-sequence intubation, and the judicious use of basic airway adjuncts, supraglottic devices, and video laryngoscopy, where available. Adapted difficult airway algorithms, front-of-neck access in the absence of surgical backup, human factors, team training, and ethical considerations are also addressed. This review aims to support safer and effective airway management for critically ill patients in resource-limited emergency and intensive care settings. Full article

The development of high-performance wood-based materials has attracted increasing interest as a means of enhancing the mechanical properties of wood for structural applications. Mechanical densification combined with chemical pretreatment is an effective approach; however, many reported methods rely on complex multi-component chemical systems or severe chemical conditions designed to dissolve lignin or hemicelluloses. In this study, a simplified NaOH-only pretreatment followed by hot-press densification was investigated, targeting selective cell-wall plasticization rather than extensive polymer dissolution. Juniper (Juniperus communis), hawthorn (Crataegus monogyna), and birch (Betula pendula) were used as samples of softwood and hardwood species. Wood specimens were pretreated in 1 M NaOH at 145 °C for 10–30 min and subsequently densified by radial compression. Changes in chemical composition were evaluated by HPLC after acid hydrolysis and FTIR spectroscopy, while microstructural changes were examined using SEM. Physical and mechanical properties were assessed through density measurements and three-point bending tests. The results show that NaOH-only pretreatment induces hemicellulose deacetylation and modification of interpolymer linkages without substantial changes in the main wood polymer contents. Densification resulted in effective lumen collapse and a compact microstructure, leading to a significant increase in density and mechanical properties. Overall, the results demonstrate that efficient wood densification and mechanical enhancement can be achieved by promoting polymer mobility through selective cleavage of interpolymer bonds, using a simplified, single-alkali pretreatment that reduces chemical complexity and material loss while avoiding extensive lignin or hemicellulose dissolution. Full article

Objectives: Thoracic endovascular aortic repair (TEVAR) is rarely indicated on an urgent or emergent basis soon after open surgical repair of type A aortic dissection (TAAD), and systematic data on clinical outcomes are therefore missing. In the present study, we analyze a contemporary case series regarding the outcome after urgent and emergent endovascular treatment of the downstream thoracic aorta, following open surgery for TAAD. Methods: The study was conducted as a retrospective observational analysis. From January 2024 until April 2025, seven patients (four male, aged 56.8 ± 5.6 years) were treated with TEVAR on an urgent or emergent basis within 48 h after open surgical repair of TAAD at our institution. In all seven patients, the initial dissection extended from the ascending to the abdominal aorta. All seven patients had previously received emergent open surgical repair by ascending aortic repair combined with hemiarch replacement (five patients) or total arch replacement, utilizing the frozen elephant trunk (FET) technique (two patients). Results: In four patients, the indication for urgent TEVAR was due to true lumen collapse (TLC) of the downstream aorta with resulting visceral or peripheral malperfusion symptoms. Three patients were treated on an emergent basis, due to rupture of the descending thoracic aorta with a resulting hemorrhage. Technical success of the TEVAR procedure was 100%. Thirty-day mortality was 0% in the TLC cases but 66% in the ruptured cases, where two of three patients died postoperatively due to the consequences of severe hemorrhagic shock. Within the surviving patients, no subsequent aortic events occurred during follow-up. Late mortality was 0%. The follow-up period was 15.7 ± 2.0 months. Conclusions: In our case series, mortality of urgent or emergent TEVAR soon after open surgical repair for TAAD is substantial, especially in patients that were treated due to acute rupture of the descending thoracic aorta and consecutive hemorrhagic shock. On the other hand, true lumen collapse with resulting malperfusion was successfully treated by instant TEVAR application in all patients without late aortic complications by the midterm follow-up. Full article

Inflammatory bowel disease (IBD) is characterized by excessive oxidative stress, mitochondrial dysfunction, and persistent activation of pro-inflammatory signaling pathways. Danthron, a natural anthraquinone derivative from rhubarb, has been reported to possess anti-inflammatory and antioxidant properties, yet its regulatory mechanisms in intestinal inflammation remain unclear. In this study, we combined network pharmacology, transcriptomic profiling, cell-based assays, intestinal organoids, and a dextran sulfate sodium (DSS)-induced colitis model to determine the protective effects of Danthron against oxidative injury. Integrated target prediction and RNA-seq analysis identified EGFR–PI3K–AKT and Nrf2–HO-1 as key signaling axes modulated by Danthron. In macrophages and intestinal epithelial cells, Danthron markedly suppressed LPS- or H₂O₂-induced ROS accumulation, lipid peroxidation, and mitochondrial membrane potential collapse, while restoring superoxide dismutase activity and reducing malondialdehyde levels. Danthron also inhibited M1 macrophage polarization, preserved epithelial tight-junction proteins, and maintained transepithelial electrical resistance. CETSA, DARTS, and molecular docking confirmed direct engagement of Danthron with components of both the EGFR–PI3K–AKT and Nrf2–HO-1 pathways. In vivo, Danthron significantly ameliorated DSS-induced colitis, reducing inflammatory cytokines, epithelial apoptosis, oxidative stress, and myeloid cell infiltration while improving mucosal architecture and enhancing organoid regenerative capacity. These findings demonstrate that Danthron exerts potent antioxidant and anti-inflammatory effects through coordinated inhibition of EGFR–PI3K–AKT signaling and activation of the Nrf2–HO-1 axis, suggesting its promise as a multi-target therapeutic candidate for IBD. Full article

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are devastating neurodegenerative diseases that, despite the availability of symptomatic and modestly beneficial treatments, still lack therapies capable of halting disease progression. A histopathological hallmark of both diseases is the cytoplasmic deposition of TDP-43 in neurons, which is attributed to both intrinsic (e.g., mutations, aberrant cleavage) and extrinsic factors (e.g., prolonged oxidative stress, impaired clearance pathways). Mutations and certain PTMs (e.g., cysteine oxidation) destabilize RNA binding, promoting monomer misfolding and increasing its half-life. Disruptions to core ubiquitin-proteasome system (UPS) subunits impede efficient processing, contributing to the clearance failure of misfolded TDP-43 monomers. The accumulation of monomers drives phase separation within stress granules, creating nucleation hotspots that eventually bypass the thermodynamic barrier, resulting in exponential growth. This rapid growth then culminates in the failure of the autophagy-lysosome pathway (ALP) to contain the aggregation, resulting in a self-sustaining feed-forward loop. Here, we organize these factors into a conceptual kinetic cascade that links TDP-43 misfolding, phase separation, and clearance failure. Therapeutic strategies must therefore move beyond simple clearance and focus on targeting these kinetic inflection points (e.g., oligomer seeding, PTM modulation). Full article

Erythrocyte aging is a fundamental physiological phenomenon that involves significant structural and nanomechanical alterations of the cells’ structure and function. Coupling optical, fluorescence, and Atomic Force Microscopy (AFM), we analyzed morphology, membrane roughness and nanomechanical properties of the very same RBCs arising from favism subjects, measured at different stages of their aging in vitro. We also investigated the evolution and abundance of vesicles arising from the cells over their senescence pathway. This approach combines high-resolution fluorescence imaging with the correlation of membrane topology and biomechanics. This explores the differences between investigation based on statistical morphometric parameters, such as membrane roughness, and those based on the measure of point-dependent nanomechanical properties. Our ultra-morphological study evidences the existence of clear differences in the aging of normal and favism erythrocytes that results in a larger number of cells with abnormal shapes and in a hyper-production of vesicles along the senescence pathway of favism cells. In explaining these differences, we focused on the roles played by the hemoglobin evolution and by the morpho-mechanical properties that are responsible for the skeletal alterations. In particular, our data reported evidence that the two corresponding degradative pathways are coupled and play an important enhancement role in promoting the progression of cell senescence. Full article

Dryland coastal–mountain systems stand at the frontline of climate change, where steep topographic gradients amplify the balance between resilience and collapse. Mount Elba—Egypt’s hyper-arid coastal–mountain reserve—embodies this fragile equilibrium, preserving a seventy-year climatic record across a landscape poised between sea and desert. Here, we present the first multi-decadal, spatio-temporal assessment (1950–2021) integrating the Standardized Precipitation–Evapotranspiration Index (SPEI-6) with satellite-derived vegetation responses (NDVI) along a ten-grid coastal–highland transect. Results reveal a pervasive drying trajectory of −0.42 SPEI units per decade, with vegetation–climate coherence (r ≈ 0.3, p < 0.05) intensifying inland, where orographic uplift magnifies hydroclimatic stress. The southern highlands emerge as an “internal drought belt,” while maritime humidity grants the coast partial refuge. These trends are not mere numerical abstractions; they trace the slow desiccation of ecosystems that once anchored biodiversity and pastoral livelihoods. A post-1990 regime shift marks the breakdown of wet-season recovery and the rise in persistent droughts, modulated by ENSO teleconnections—the first quantitative attribution of Pacific climate signals to Egypt’s coastal mountains. By coupling climatic diagnostics with ecological response, this study reframes drought as a living ecological process rather than a statistical anomaly, positioning Mount Elba as a sentinel landscape for resilience and adaptation in northeast Africa’s rapidly warming drylands. Full article

Background/Objectives: Pauls Stradins Clinical University Hospital in Riga, Latvia, introduced an ECMO program in 2008. Since the program’s start, countless patients have had their lives saved by this necessary technology. Our goal was to review the ECMO program results and gain insight into the organization’s operations. We wanted not only to assess the program’s efficiency in terms of time, but also to visualize patient outcomes at least a month after decannulation from ECMO and discharge from the hospital. Methods: A retrospective observational study was performed using hospital patient data files from October 2024 to October 2025. The selected patient group was those who had suffered an in-hospital cardiac arrest and successfully had ECMO inserted; this criterion fit fifteen patients. Data were collected on multiple factors, including from collapse to flow time, the number of days spent in the ICU, and post-ECMO complications. Afterwards, the data were analyzed to understand the program’s and patients’ outcomes. Results: Of the fifteen patients analyzed, seven did not survive to hospital discharge. The statistically significant quantitative results were the first lactate levels after ECMO cannulation and the first troponin levels after cardiac arrest. In terms of qualitative results, CHF, survival to ECMO decannulation, cannulation failure, and survival to ICU discharge were statistically significant. Conclusions: The ECMO program at Pauls Stradins Clinical University Hospital provides patients with a necessary technology after an intra-hospital cardiac arrest. This study highlights data about these patients and their outcomes, as well as areas for improvement within the hospital’s ECMO/ECPR program. Full article

Background: Complications after proximal humerus osteosynthesis are not uncommon. The aim of this study was to compare the outcomes of osteosynthesis using PHILOS with fresh-frozen femoral head allograft augmentation and without it, and to assess the influence of risk factors and their impact on the occurrence of postoperative complications. Methods: This retrospective study evaluates the radiological outcomes and complications of treating proximal humerus fractures (Neer III–IV) in 116 patients over 50 years of age treated between 2017 and 2021. Results: Osteosynthesis without allograft was performed in 84 patients and with allograft in 32 patients. In total, 42 patients (36%) had a three-part fracture and 74 (64%) had a four-part fracture. The Deltoid Tuberosity Index was comparable between the groups (1.59 ± 0.25 vs. 1.50 ± 0.26; p = 0.802). The average duration of surgery was 101.3 ± 21.3 min with allograft and 86.0 ± 31.9 min without allograft (p = 0.004). AVN was verified in four patients (3.5%), head collapse in nine (8%), cut-out in six (5%), reoperation in eight (7%), infection in three (2.5%), and pseudoarthrosis in one (1%) case. Conclusions: An allograft augmentation improves construct stability, but cannot compensate for inadequate surgical technique. None of the risk factors significantly influenced the development of AVN and pseudoarthrosis. The greater tubercle comminution (p = 0.005), calcar loss (p = 0.020, p = 0.112), allograft augmentation (p < 0.001), and medial hinge restoration (p = 0.012, p = 0.002) were significant risk factors associated with HC and screw cut-out, respectively. The greater tubercle redislocation was influenced by its comminution, calcar loss, and the use of allograft augmentation. HFZ and DTI had no significant impact on surgery results or complications. Full article