Search Results (5,693)

This study investigates the effect of welding speed on the microstructure and mechanical properties of pulsed laser lap-welded 0.2 mm 316L stainless steel sheets, commonly used in fuel cell bipolar plates. Welding speeds ranging from 6 to 26 mm/s were tested while other laser parameters remained constant. Results show that increasing welding speed reduces heat input, overlap factor, and weld dimensions. A transition from full to partial penetration occurs beyond 6 mm/s, with no visible heat-affected zone. The weld microstructure features columnar ferrite near fusion boundaries and globular ferrite in the center. Tensile–shear tests reveal that welds maintain higher strength than the base metal up to 22 mm/s, with all fractures occurring in the base material. An optimal speed range of 10–14 mm/s ensures defect-free joints with improved mechanical performance. These findings provide practical guidance for thin-gauge stainless steel welding in fuel cell applications. Full article

Background: Several mitochondrial abnormalities such as defective energy production, depletion of energy stores, Ca²⁺ accumulation, generation of reactive oxygen species, and impaired intracellular signaling are associated with cardiac dysfunction during the development of different heart diseases. Methods: A narrative review was compiled by a search for applicable literature in MEDLINE via PubMed. Results: Mitochondria generate ATP through the processes of electron transport and oxidative phosphorylation, which is used as energy for cardiac contractile function. Mitochondria, in fact, are the key subcellular organelle for the regulation of intracellular Ca²⁺ concentration and are considered to serve as a buffer to maintain Ca²⁺ homeostasis in cardiomyocytes. However, during the development of heart disease, the excessive accumulation of intracellular Ca²⁺ results in mitochondria Ca²⁺-overload, which, in turn, impairs mitochondrial energy production and induces cardiac dysfunction. Mitochondria also generate reactive oxygen species (ROS), including superoxide anion radicals and hydroxyl radicals as well as non-radical oxidants such as hydrogen peroxide, which promote lipid peroxidation and the subsequent disturbance of Ca²⁺ homeostasis, cellular damage, and death. Conclusion: These observations support the view that both oxidative stress and intracellular Ca²⁺-overload play a critical role in mitochondrial disruption during the pathogenesis of different cardiac pathologies. Full article

Progressive familial intrahepatic cholestasis type 2 (PFIC2) is a severe hepatocellular cholestasis due to biallelic variations in the ABCB11 (ATP-binding cassette B11) gene encoding the canalicular bile salt export pump (BSEP). Some missense variants identified in patients with PFIC2 do not traffic properly to the canalicular membrane. However, 4-phenybutyrate (4-PB) has been shown in vitro to partially correct the mis-trafficking of selected variants, resulting in an improvement of the medical conditions of corresponding PFIC2 patients. Herein, we report the ability of 4-PB analogous or homologous drugs and of non-4-PB related chemical correctors to rescue the canalicular expression and the activity of the folding-defective Abcb11^R1128C variant. New compounds, either identified by screening a chemical library or designed by structural homology with 4-PB (or its metabolites) and synthesized, were evaluated in vitro for their ability to (i) correct the canalicular localization of Abcb11^R1128C after transfection in hepatocellular polarized cell lines; (ii) restore the ³H-taurocholate transport of the Abcb11^R1128C protein in Madin–Darby canine kidney (MDCK) cells stably co-expressing Abcb11 and the sodium taurocholate co-transporting polypeptide (Ntcp/Slc10A1). Glycerol phenylbutyrate (GPB), phenylacetate (PA, the active metabolite of 4-PB), 3-hydroxy-2-methyl-4-phenylbutyrate (HMPB, a 4-PB metabolite analog chemically synthesized in our laboratory) and 4-oxo-1,2,3,4-tetrahydro-naphthalene-carboxylate (OTNC, from the chemical library screening) significantly increased the proportion of canalicular Abcb11^R1128C protein. GPB, PA, ursodeoxycholic acid (UDCA), alone or in combination with 4-PB, suberoylanilide hydroxamic acid (SAHA), C18, VX-445, and/or VX-661, significantly corrected both the traffic and the activity of Abcb11^R1128C. Such correctors could represent new pharmacological insights for improving the condition of patients with ABCB11 deficiency due to missense variations affecting the transporter’s traffic. Full article

Mutations in the TP63 gene cause several syndromic disorders, including ankyloblepharon–ectodermal defects–cleft lip/palate (AEC) syndrome, characterized by severe skin erosions, cleft palate, and ectodermal dysplasia. These mutations often affect the carboxy-terminal sterile-α-motif (SAM) domain of the p63 protein, leading to domain misfolding, protein aggregation, and impaired transcriptional activity. To dissect the molecular mechanisms underlying AEC pathogenesis, we investigated primary keratinocytes derived from p63L514F mutant mice, which carry a SAM domain mutation associated with AEC syndrome. p63L514F keratinocytes exhibited significantly reduced proliferation compared to wild-type controls, as indicated by decreased 5-ethynyl-2′-deoxyuridine (EdU) incorporation, decreased Cyclin D1 and Cyclin D2 expression, and an increase in the cell-cycle inhibitors p21 and p27. Furthermore, p63L514F keratinocytes showed increased cell death, elevated reactive oxygen species (ROS) levels, and a decreased reduced (GSH) and oxidized (GSSG) glutathione (GSH/GSSG) ratio, indicating oxidative stress. This stress response was accompanied by a marked reduction in Solute Carrier Family 7 Member 11 (Slc7a11), a critical regulator of antioxidant defense. We further identified Slc7a11 as a likely direct transcriptional target of p63: p63 depletion reduced Slc7a11 expression, and chromatin immunoprecipitation uncovered an evolutionary conserved p63-binding enhancer upstream of the Slc7a11 promoter. Together, our findings demonstrate that p63 mutations causative of AEC syndrome impair keratinocyte proliferation, promote cell death via oxidative stress, and compromised antioxidant defenses, revealing a dual role for p63 in sustaining skin homeostasis. Full article

Background/objectives: Fanconi anemia (FA) is an inherited bone marrow failure syndrome characterized by chromosome instability and predisposition to develop myelodysplastic neoplasm (MDS) and acute myeloid leukemia (AML). Clonal chromosome aberrations (CCAs) in chromosomes 1, 3, and 7 frequently appear in the bone marrow (BM) of patients with FA and are associated with MDS/AML progression. Given the underlying DNA repair defect that characterizes FA, non-clonal chromosomal abnormalities (NCCAs) are expected to be common events in the FA BM; in this study, we investigated the presence and significance of NCCA and CCA in the bone marrow (BM) of patients with FA. Methods: Here, we transversally examined the BM karyotypes of 43 non-transplanted patients with FA, 41 with non-clinically detectable hematologic neoplasia and two with diagnosed MDS. We searched for the presence of NCCAs, complex karyotypes (CKs), and CCAs as well as their association with the natural history of the disease, including age, degree of BM failure, and neoplastic transformation. Results: NCCAs were observed in the metaphase spreads of 41/43 FA patients; CKs were observed in 25/43 patients; CCAs were found in 15/43 patients; CCAs involving chromosomes 1, 3 and/or 7 were found in four patients; and other autosomes were found in the remaining 11 patients. Overall, we observed a baseline large karyotypic heterogeneity in the BM of FA patients, demonstrated by the ubiquitous presence of NCCA; such karyotypic heterogeneity precedes the eventual emergence of CKs and selection of cells carrying fitness-improving CCAs. Finally, CCAs involving chromosomes 1, 3 and 7, well-known drivers of hematological malignancy in FA, become established. Overall, we observed that the frequency of NCCAs and CCAs increased with age, even though a significant correlation was not found. Conclusions: These observations fit the model of evolution towards cancer that comprises a first phase of macroevolution represented by NCCAs and karyotypic heterogeneity, followed by the establishment of clones with CCAs, leading to microevolution and cancer. NCCAs are the most frequent chromosomal alterations in the bone marrow of patients with AF and constitute a genome with extensive karyotypic heterogeneity that evolves into clones with more complex genomes and can eventually progress to cancer. Full article

Background/Objectives: To evaluate the neuromodulative effects of oral intake of a fixed combination of citicoline 500 mg plus homotaurine 50 mg plus vitamin B3 54 mg plus pyrroloquinoline quinone (CIT/HOMO/B3/PPQ) or of citicoline 800 mg alone (CIT800) on retinal ganglion cell (RGC) function in glaucoma patients by pattern electroretinogram (PERG) and to investigate the effects on quality of life and visual function. Methods: Consecutive patients with primary open-angle glaucoma with controlled IOP (<18 mmHg) receiving prostaglandin analogues as monotherapy; with two reliable visual fields (Humphrey 24-2 SITA Standard) per year in the last 2 years; and an early to moderate visual field defect (MD < −12 dB) were randomized to: arm A. topical therapy + CIT/HOMO/B3/PPQ for 4 months, followed by 4 months of topical therapy + CIT800; and arm B. topical therapy + CIT800 for 4 months, then topical therapy + CIT/HOMO/B3/PPG for 4 months. Patients were examined at month 0, 4, and 8. Complete ocular examination, visual field test, PERG, and quality of life assessment (NEI-VFQ25) were performed at each visit. Results: Forty patients were selected and completed the study, and none developed or reported an adverse event. The overall mean age was 64.2 (±7.7) years, 27 were male. At the end of the intake period of both products, patients exhibited higher P50 and N95-wave amplitudes and shorter latencies compared to baseline. The crossover analysis found that PERG parameters were better when patients received the CIT/HOMO/B3/PQQ combination with a statistically significant shorter peak time of 1.24 ms (95% CI, 0.37 to 2.10; p = 0.006) in the central P50 wave, 1.32 ms (95% CI, 0.44 to 2.22; p = 0.004) in the inferior P50 wave, and 1.70 ms (95% CI, 0.09 to 3.31; p = 0.038) in the inferior N95 wave; and a statistically significant increase of 0.35 µV (95% CI, 0.10 to 0.60; p = 0.006) in the superior N95 amplitude. The crossover analysis did not reveal any significant differences between the intake of CIT800 and CIT/HOMO/B3/PQQ in terms of visual acuity or IOP. During the intake of CIT/HOMO/B3/PQQ, a significant improvement was observed in the total mean score (p = 0.004), in the general health scale (GH, p = 0.01), in the color vision scale (p = 0.006), and in the peripheral vision scale (p = 0.001). Conclusions: The present study has shown that the addition of CIT/HOMO/B3/PQQ in early glaucoma improves PERG parameters and quality of life, likely by slowing down RGC aging and enhancing mitochondrial function more significantly than citicoline 800 mg alone. Full article

In the past, only Oguchi disease was reported as a hereditary retinal disease from Japan. Dr. Chuuta Oguch was a Professor of Nagoya University in Japan. During the past 40 years, four new clinical entities in hereditary retinal disorders have been detected by the Miyake group from Nagoya, Japan. All disorders show essentially normal fundi, and the diagnosis was made mainly by the analysis of an electroretinogram (ERG). Gene mutations are detected in three of them. Bipolar cell (BP) dysfunction syndrome: Congenital stationary night blindness (CSNB) with negative ERG (a-wave is larger than b-wave) was named as the Schubert–Bornschein type in 1952 and considered to be an independent clinical entity. In 1986, Miyake group classified ninety patients with the Schubert–Bornschein type into two types (complete and incomplete type). The complete type of CSNB (CSNB1) showed no rod function, but the incomplete type CSNB (CSNB2) showed remaining rod function in both subjective dark adaptation and rod ERG. In order to investigate the pathogenesis, these two types of CSNB were analyzed by comparing the monkey ERGs using different glutamate analogs to the retina. The ERG analysis demonstrated that CSNB1 has a complete functional defect in the ON type BP, while CSNB2 has incomplete functional defects in the ON and OFF type BP in both rod and cone visual pathways. Evidence of several different genetic heterogeneities was reported in both diseases, indicating CSNB1 and CSNB2 are independent clinical entities. Another entity, showing total complete defect of both ON and OFF BP, was detected in 1974 and was reported by Miyake group in a brother and younger sister, showing severe photophobia, nystagmus, extremely low visual acuity, and disappearance of color vision (total color blindness). This disorder is a congenital stational condition, and subjective visual functions were severely deteriorated from birth but remained unchanged through life. This disease was termed “Total complete bipolar cell dysfunction syndrome (CSNB3)”. The relationship between BP and subjective visual function was unknown. These three kinds of BP diseases can provide information on how BP relates to subjective visual functions. Occult macular dystrophy (OMD): Occult macular dystrophy (OMD) was discovered by Miyake group in 1989. This disease shows an unusual, inherited macular dystrophy characterized by progressive decrease visual acuity due to macular dysfunction, but the fundus and fluorescein angiography are essentially normal. The full-field rod and cone ERG do not show any abnormality, but the focal macular ERG (FERG) or multifocal ERG is abnormal and the only method for diagnosis. Many pedigrees of this disorder suggest autosomal dominant heredity, showing a genetic mutation of RP1L1. This disease was termed “occult macular dystrophy”. “Occult” means “hidden from sight”. Recently, it has been called “Miyake disease”. Full article

With the emergence of the SARS-CoV-2 pandemic the process of coronavirus replication has been under increasing scrutiny. During the replication of their genomic RNA, coronaviruses produce a range of other RNAs in addition to the negative-sense replicative intermediates of the genome, which includes a set of subgenomic RNAs. These subgenomic RNAs are nested within the sequence of the complete genome and can be both replicated further and act as templates for protein production. Alongside these functional products of discontinuous replication, coronaviruses produce defective viral genomes that can potentially impact both the virus and infected host cells. These interactions can arise from the ability of these defective viral genomes to impact the production of new infectious virions, through either competition with the wild-type genome for replication or by stimulating an antiviral response. Examining the behaviour of defective viral genomes can also help to elucidate the functional elements of the genome involved in the processes of replication and packaging. This review covers the process of intracellular replication by coronaviruses describing the mechanisms by which the different RNA species are produced. Of particular focus are factors involved in discontinuous replication that produces defective viral genomes, and the behaviour of coronavirus defective viral genomes. Full article

Tin oxide (SnO₂) is an attractive candidate for the electron transport layer (ETL) in perovskite-based solar cells because of its low temperature process requirement. The ability to form ETL layers at low temperatures opens up opportunities for the use of flexible and low-cost materials suitable for photovoltaic applications. The ETL is necessary for the extraction of electrons and charge separation from the perovskite active layer. Herein, we present a study of the effect of annealing temperature on SnO₂ used as an ETL. The annealing temperature of the SnO₂ has a considerable effect on the morphology, crystallinity, grain size, and surface topography of the SnO₂ layer. The surface properties of the ETL influence the structural properties of the perovskite films. In this study, the annealing temperature of the SnO₂, deposited using spin coating, was changed from 90 °C to 150 °C. The SnO₂ films annealed at 120$°$C resulted in reduced surface defects, improved electron extraction, and produced a significant increase in the grain size of the perovskite active layers. The increase in grain size led to improved efficiency of the PSCs. Devices annealed at 120 °C yielded PSCs with an average efficiency of 15% for a 0.36 cm² active area, while devices treated at 90 °C and 150 °C produced an average efficiency of 12%. The PSCs fabricated at low temperatures provide an effective technique for low-cost manufacturing, especially on flexible and polymer-based substrates. Full article

Background: Systemic sclerosis (SSc) is a rare connective tissue disease characterized by vasculopathy, autoimmunity, and fibrosis. Due to its low prevalence and heterogeneous clinical presentation, early diagnosis remains challenging, often delaying appropriate treatment. The disease progresses from microvascular dysfunction, manifesting as Raynaud’s phenomenon, to systemic fibrosis affecting multiple organs, including the lungs, gastrointestinal tract, heart, and kidneys. There have been considerable advancements in understanding the pathophysiology of the disease during the last few years and this has already resulted in the improvement of the therapeutic approaches used to control organ-specific manifestations. However, the underlying cause of the disease still remains incompletely elucidated. Methods: Here, we summarize the current knowledge on the SSc pathogenesis. Results: The pathophysiology involves an interplay of chronic inflammation, impaired vascular function, and excessive extracellular matrix deposition, leading to progressive organ damage. Endothelial dysfunction in SSc is driven by immune-mediated injury, oxidative stress, and the imbalance of vasoconstrictors and vasodilators, leading to capillary loss and chronic hypoxia. Autoantibodies against endothelial cells or other toxic factors induce apoptosis and impair angiogenesis, further exacerbating vascular damage. Despite increased angiogenic factor levels, capillary repair mechanisms are defective, resulting in progressive ischemic damage. Dysregulated immune responses involving Th2 cytokines, B cells, and macrophages contribute to fibroblast activation and excessive collagen deposition. Transforming growth factor-beta (TGF-β) plays a central role in fibrotic progression, while fibroblasts resist apoptosis, perpetuating tissue scarring. The extracellular matrix in SSc is abnormally stiff, reinforcing fibroblast activation and creating a self-perpetuating fibrotic cycle. Conclusions: Advances in molecular and cellular understanding have facilitated targeted therapies, yet effective disease-modifying treatments remain limited. Future research should focus on precision medicine approaches, integrating biomarkers and novel therapeutics to improve patient outcomes. Full article

Organic–inorganic hybrid flexible perovskite solar cells (F-PSCs) have garnered considerable interest owing to their exceptional power conversion efficiency (PCE) and stable operational characteristics. However, F-PSCs continue to exhibit significantly lower PCE than their rigid counterparts. Herein, we employed 3-chloro-4-methoxybenzylamine hydrochloride (CMBACl) treatment to grow in situ two-dimensional (2D) perovskite layers on three-dimensional (3D) perovskite films. Through comprehensive physicochemical characterization, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) mapping, we demonstrated that CMBACl treatment enabled the in situ growth of two-dimensional (2D) perovskite layers on three-dimensional (3D) perovskite films via chemical interactions between CMBA⁺ cations and undercoordinated Pb²⁺ sites. The organic cation (CMBA⁺) bound to uncoordinated Pb²⁺ ions and residual PbI₂, while the chlorine anion (Cl⁻) filled iodine vacancies in the perovskite lattice, thereby forming a high-quality 2D/3D heterojunction structure. The CMBACl treatment effectively passivated surface defects in the perovskite films, prolonged charge carrier lifetimes, and enhanced the operational stability of the photovoltaic devices. Additionally, the hybrid 2D/3D architecture also improved energy band matching, thereby boosting charge transfer performance. The optimized flexible devices demonstrated a PCE of 23.15%, while retaining over 82% of their initial efficiency after enduring 5000 bending cycles under a 5 mm curvature radius (R = 5 mm). The unpackaged devices retained 94% of their initial efficiency after 1000 h under ambient conditions with a relative humidity (RH) of 45 ± 5%. This strategy offers practical guidelines for selecting interface passivation materials to enhance the efficiency and stability of F-PSCs. Full article

Objectives: Nasal mucosa wound healing faces challenges such as acidic microenvironments and bacterial proliferation. Persistent mucosal defects predispose to complications such as nasal septal perforation. Conventional drug delivery systems suffer from nonspecific release and short-term efficacy. This study aimed to develop a pH-responsive liposome-hydrogel composite (HYD-Lip/DXMS@HG) to integrate pH-triggered dexamethasone (DXMS) delivery, antifouling properties, and mechanical support for refractory injuries. Methods: The composite combined acylhydrazone-modified liposomes with a hydrogel synthesized from hydroxyethylacrylamide (HEAA) and diethylacrylamide (DEAA). In vitro assays evaluated DXMS release kinetics, RPMI 2650 cell migration/proliferation, and antibacterial properties. In vivo rabbit nasal mucosal injury models assessed healing efficacy via histology analyses. RNA sequencing was performed to identify key signaling pathways. Results: HYD-Lip/DXMS@HG exhibited sustained DXMS release in acidic conditions, accelerating cell migration/proliferation in vitro. In rabbits, the composite reduced TNF-α expression and CD45+ leukocyte infiltration, while enhancing collagen alignment and epithelial thickness. RNA sequencing identified upregulated ECM receptor interaction, Hippo, TGF-β, and PI3K-Akt pathways, linked to collagen remodeling, anti-apoptosis, and angiogenesis. Conclusions: This multifunctional platform synergizes pH-triggered drug delivery, mechanical support, and antibacterial activity, offering a promising therapeutic strategy for refractory nasal mucosal injuries and postoperative recovery. Full article

Bone diseases lead to an increasing demand for implants to treat long bone defects and for load-bearing applications. Osteoporosis care and accidental injuries are major contributors to this rising need. Our research aims to demonstrate innovative material systems and methods for preparing implants that can be used in regenerative medicine. We hypothesize that by combining titanium alloys (Ti6Al4V) with hydroxyapatite (Hap), we can enhance biocompatibility and tribo-mechanical performance, which are critical for the longevity of Ti-based surgical implants. Additionally, we investigate the application of laser surface treatments to expose the underlying porosity, thereby enhancing cell transport and promoting cell growth. In this study, we investigate the effects of two fabrication techniques—Spark Plasma Sintering (SPS) and powder metallurgy (PM)—on the properties of laser-textured Ti64/Hap biocomposites. Our findings demonstrate that the selected processing route significantly influences the microstructure, tribological performance, and surface properties of these materials. An X-ray diffraction (XRD) analysis corroborates our results from incubation studies in simulated body fluids, highlighting the impact of phase transformations during sintering on the chemical properties of Ti-Hap composites. Additionally, while laser surface texturing was found to slightly increase the friction coefficient, it markedly enhanced the wear resistance, particularly for the PM and SPS Ti + 5%Hap composites. Full article

Neural crest cells (NCCs) play a significant role in the development of ventricular outflow tracts (OFTs), and cardiac neural crest cells (cNCCs) are involved in the development of the embryonic conus, suggesting that these cell lineages may be a teratogenic target for the development of cardiopathies in offspring conceived under a hyperglycemic environment. We evaluate the effect of the hyperglycemic intrauterine environment on the morphological and anatomical changes in the conal ridges along with the alterations in the spatiotemporal expression of AP2α in offspring hearts at 13, 15, and 17 DPC. The anatomical and histological analysis of the hearts in the experimental group presented smaller dimensions compared to the control group in the offspring at the three ages studied. Consequently, this resulted in a hyperglycemic environment that altered the immunostaining of AP2α in the hearts of the offspring at the three ages studied. Thus, the hyperglycemic intrauterine environment in offspring caused important morphological alterations in the development of conal ridges and promoted the generation of conotruncal heart defects in which the double outlet of the right ventricle, the atrioventricular (AV) canal, predominated. Therefore, knowing that exposing the offspring to more glucose potentially can lead to complications during organogenesis of the circulatory and central nervous systems. Full article

Multiple sclerosis (MS) is a neuroinflammatory disease where oxidative stress and DNA damage may influence disease progression. We investigated whether defects in base excision repair (BER) pathways contribute to MS by combining functional DNA repair assays, gene expression profiling, and genotype analysis. We collected peripheral blood mononuclear cells from 70 MS patients and 61 healthy controls. These cells were subjected to tert-butyl hydroperoxide (TBH)-induced oxidative stress, and comet assay kinetics were measured over a period of 60 min. Additionally, we quantified the mRNA expression of nine key BER genes and genotyped selected polymorphisms related to DNA repair capacity. Samples from MS patients exhibited significantly higher levels of TBH-induced DNA lesions and displayed a distinct repair trajectory over time, as indicated by area-under-the-curve (AUC) analyses (p < 0.001). The transcripts of MBD4 and NTHL1 were notably reduced in MS patients compared to those in the controls (p < 0.0001). A logistic regression analysis revealed an association between the specific BER-related single nucleotide polymorphisms (SNPs) rs3087404, rs4135054, and rs1052133 and ineffective DNA repair. Subset analyses of B cells, CD4⁺ cells, and CD8⁺ cells further supported the presence of altered repair kinetics in MS, even though some subsets exhibited similar baseline lesion levels. Our findings suggest that impaired oxidative DNA repair is present in MS, likely driven by functional deficits in repair kinetics and alterations in the expression of BER genes and polymorphisms. This integrated approach highlights DNA repair pathways as potential therapeutic or prognostic targets in MS. Full article