Search Results (74)

The paper presents a method for obtaining partially degradable capillary membranes from a polyethersulfone/polycaprolactone (PES/PCL) mixture. PES/PCL membranes were obtained by the phase inversion technique with dry/wet spinning and then subjected to controlled degradation in an alkaline environment (1 M NaOH) and simulated body fluid (SBF with pH 7.4) using the flow method. The aim of the work was to select and apply a degradable, non-toxic, simple polymer as a removable component of the membrane structure. The degradable component of the membranes was PCL, the gradual hydrolysis of which was aimed at increasing the porosity and improving the transport properties of the membranes during operation. The membrane properties, such as hydraulic permeability coefficient (UFC), retention coefficient, and structural morphology, were assessed using scanning electron microscopy (SEM) before and after degradation. Analysis of SEM images performed with MeMoExplorer^TM software showed an increase in the proportion of large pores (above 300 µm²) and total porosity of the membranes after degradation in NaOH and SBF. Low instability factor (<0.25) for all samples, both before and after degradation, confirms the good repeatability of the membrane structure. An increase in the UFC was observed, while the retention coefficients did not change significantly in the case of membranes after the etching process. The degradation of the PCL component in the membrane was assessed using the weight method. Measurements of the membrane mass loss before and after degradation confirmed the removal of over 50 wt.% of the PCL component in SBF and 70 wt.% in NaOH from the tested membranes, which resulted in an increase in permeability due to increased membrane porosity. The results indicate the possibility of using such structures as functional, partially self-regulating membranes, potentially useful in biomedical and environmental applications. Full article

The Xiaobaihegou fluorite deposit is located in the southwest of the Altyn-Tagh Orogen, NW China. However, the provenance, thermodynamic properties, and enrichment mechanisms of the ore-forming fluids in this deposit remain unclear. Fluorite mineralization primarily occurs in the vicinity of the contact zone between the granite and the wall rocks. The zircon U-Pb age of the alkali-feldspar granite in the Xiaobaihegou fluorite deposit is 482.3 ± 4.1 Ma. The ore-hosting lithologies are mainly calcareous rock series of the Altyn Group. The ore bodies are controlled by NE-trending faults and consist primarily of veined, brecciated, massive, and banded ores. The ore mineral assemblage is primarily composed of calcite and fluorite. The rare earth element (REE) patterns of fluorite and calcite in the Xiaobaihegou deposit exhibit right-dipping LREE enrichment with distinct negative Eu anomalies, which closely resemble those of the alkali-feldspar granite. This similarity suggests that the REE distribution patterns of fluorite and calcite were likely inherited from the pluton. The ore-forming process can be divided into an early stage and a late stage. The massive ores formed in the early stage contain mainly gas-rich two-phase fluid inclusions and CO₂-bearing three-phase inclusions, with homogenization temperatures ranging from 235 °C to 426 °C and salinities from 28.59% to 42.40% NaCl equivalent. In the late stage, brecciated and stockwork ores were formed. They host liquid-rich two-phase and gas-rich two-phase fluid inclusions, with homogenization temperatures ranging from 129 °C to 350 °C and salinities from 0.88% to 21.61% NaCl equivalent. The results of hydrogen and oxygen isotope studies indicate that the ore-forming fluids were derived from a mixture of magmatic–hydrothermal and meteoric water. Fluorite precipitation in the early stage was mainly due to the mixing of magmatic–hydrothermal solution and meteoric water, as well as a water–rock reaction. In the late stage, fluid mixing further occurred, resulting in a decrease in temperature and the formation of brecciated and stockwork ores. The ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd ratios of fluorite from the deposit range from 0.71033 to 0.71272 and 0.511946 to 0.512073, respectively, indicating that the ore-forming material originates from the crust. Based on the ore-forming characteristics, it is proposed that Ca may be primarily leached from the strata formation, while F may predominantly originate from magmatic–hydrothermal solutions. The formation of fluorite deposits is closely related to the transition of the Central Altyn-Tagh Block and Qaidam Block from a compressional orogenic environment to an extensional tectonic environment. Full article

The Erentaolegai silver deposit is located within the Derbugan metallogenic belt in the eastern segment of the Central Asia–Mongolia giant orogenic belt. The ore bodies are primarily hosted in the volcanic rocks of the Middle Jurassic Tamulangou Formation of the Mesozoic. The mineralization process of the deposit is divided into three stages: Stage I: Pyrite–Quartz Stage; Stage II: Sulfide–Quartz Stage; Stage III: Quartz–Manganese Carbonate Stage. This paper discusses the ore-forming fluids, ore-forming materials, and deposit genesis of the Erentaolegai silver deposits using fluid inclusions microthermometry, laser Raman spectroscopy, and H-O-S isotope analyses. Fluid inclusion microthermometry and laser Raman spectroscopy analyses indicate that the Erentaolegai silver deposit contains exclusively fluid-rich two-phase fluid inclusions, all of which belong to the H₂O-NaCl system. Homogenization temperatures of fluid inclusions in the three stages (from early to late) ranged from 257 to 311 °C, 228 to 280 °C, and 194 to 238 °C, corresponding to salinities of 1.91 to 7.86 wt%, 2.07 to 5.41 wt%, and 0.70–3.55 wt% NaCl equivalent, densities of 0.75 to 0.83 g/cm⁻³, 0.80 to 0.86 g/cm⁻³ and 0.85 to 0.89 g/cm⁻³. The mineralization pressure ranged from 12.2 to 29.5 MPa, and the mineralization depth was 0.41 to 0.98 km, indicating low-pressure and shallow-depth mineralization conditions. H-O isotope results indicate that the ore-forming fluid is a mixture of magmatic fluids and meteoric water, with meteoric contribution dominating in the late stage. The δ³⁴S values of metallic sulfides ranged from −1.8 to +4.0‰, indicating that the metallogenic material of the Erentaolegai silver deposit was dominated by a deep magmatic source. This study concludes that meteoric water mixing and subsequent fluid cooling served as the primary mechanism for silver mineral precipitation. The Erentaolegai silver deposit is classified as a low-sulfidation epithermal silver deposit. Full article

Pelagic sargassum arriving in the Mexican Caribbean is a mixture of brown macroalgae containing polysaccharides, minerals, and secondary metabolites with potential in ruminant diets. The objective of the present study was to evaluate the effect of the inclusion of sargassum in integral diets (ID) on in vitro fermentation characteristics. A completely randomized design was used. The treatments were different levels of sargassum (ICD: 0%, ID10: 10%, ID20: 20% and ID30: 30%) added to a basal substrate (a mixture of Pennisetum purpureum Vc. CT-115 hay, corn, soybean, and molasses). Rumen fluid was obtained from five male lambs with a body weight of 40 ± 3 kg. In vitro gas production (IVGP) as well as dry matter degradability (DMD) and organic matter degradability (DOM) increased linearly (p < 0.0001) as the proportion of sargassum increased at 24, 48, and 72 h. Rumen fluid pH decreased (p < 0.05) with 30% inclusion at 48 h, while protozoan concentration was similar (p > 0.05) in all treatments with respect to the control at all evaluation times. These results indicate that the inclusion of pelagic sargassum in integral concentrated diets improves fermentative parameters, and its inclusion in diets for ruminants is feasible. This opens up a window of opportunity for its study as a novel additive or unconventional supplement. However, in vivo studies are necessary to rule out harmful effects on animal health and performance. Full article

Background: The identification of body fluids collected from crime scenes is crucial for determining the type and nature of assaults and for advancing the resolution of crimes. Objectives: The primary aim of this study was to investigate tissue-specific DNA methylation markers that can effectively distinguish buccal samples from blood, semen, and vaginal epithelial tissue. Methods: We screened various markers and selected four genomic locations for further analysis. Genomic DNA was extracted from tissue samples, followed by bisulfite conversion, locus-specific polymerase chain reaction (PCR) amplification, and pyrosequencing. Results: Four loci—cg-9652652, cg-11536474, cg-3867465, and cg-10122865—along with several adjacent CpG sites, were found to be hypermethylated in buccal samples compared to other tissue types. The difference in DNA methylation of buccal samples was statistically significant (p < 0.0001) compared to other tissues, indicating the potential usefulness of these loci for forensic tissue identification. Two additional studies were conducted: (a) a species specificity study and (b) a mixture study involving two different tissue types. The species specificity study showed that the primers used in the assay were specific to primates and humans. They did not amplify five non-primate samples, while the two primate samples—chimpanzee and rhesus—provided usable methylation data. The mixture study involved DNA from two different tissues—buccal samples and semen—combined in varying proportions. The results showed a decrease in the overall percentage of DNA methylation at the locus cg-9652652 as well as five adjacent CpG sites when the amount of buccal cell DNA in the mixture was reduced. Conclusion: The specificity of the primers and the significant differences in percent DNA methylation between buccal cells and other tissues make these markers excellent candidates for forensic tissue identification. Full article

Background: Rapid on-site evaluation (ROSE) is crucial for improving the diagnostic yield of fine-needle aspiration (FNA) biopsies. Despite recent advances in ROSE, such as telecytology, the rapid stains used in this process have not seen significant innovation. Diff-Quik (DQ) and Toluidine Blue (TB), the most common ROSE stains, have significant limitations. This study evaluates the optimized Toluidine Blue stain, a mixture of Toluidine Blue, Eosin, and Alcohol (TEA), as a potential alternative to TB or DQ for ROSE. Methods: A comparative study was conducted using fifty remnant body fluid specimens with adequate cellularity, collected at the University of California Davis Medical Center over six months. Two smears were prepared from each specimen. One was stained with TB, and the other with optimized Toluidine Blue (TEA). Digital images of each slide were evaluated by three cytologists and two cytopathologists, blinded to the stain, using five criteria: background staining, cytoplasmic detail, nuclear membrane clarity, chromatin texture, and nucleoli staining. Each criterion was scored on a scale of 1 to 3. Results: Optimized Toluidine Blue (TEA) stain demonstrated superior overall image quality compared to TB. Specifically, optimized Toluidine Blue (TEA) showed significantly less background staining (p < 0.05) and improved nuclear membrane clarity (p < 0.05), chromatin texture (p < 0.05), and nucleoli detail (p < 0.05). There was no significant difference between the two stains in the assessment of cellularity or cytoplasmic detail. Conclusions: The optimized Toluidine Blue (TEA) stain shows promise as a rapid stain for ROSE, offering rapid processing and improved digital image quality. Further evaluation of optimized Toluidine Blue (TEA) stain on FNA specimens is warranted to validate these findings and explore its potential to enhance telecytology in ROSE. Full article

The last decades have offered new challenges to researchers worldwide through the problems our planet is facing both in the environmental protection field and the need to replace fossil fuels with new environmentally friendly alternatives. Bioenergy, as a form of renewable energy, is an acceptable option from all points of view, and biofuels, due to their biological origin, have the ability to satisfy the new needs of humanity. As they release non-polluting combustion products into the atmosphere, biofuels have already been adopted as additives in traditional liquid fuels, intended mainly for the internal combustion engines of automobiles. The current work proposes an extension of the biofuel application in combustion processes specific to industrial furnaces. This technical concern has not been found in the literature, except for the achievements of the research team involved in this work, who performed the previous investigations. A 51.5 kW burner was designed to operate with glycerin originating from the triglycerides of plants and animals, mixed with ethanol, an alcohol produced by the chemical industry recently used as an additive in gasoline for automobile engines. Industrial oxygen was chosen as the oxidizing agent necessary for the liquid mixture combustion, allowing us to obtain much higher flame temperatures compared with the usual combustion processes using air. Mixing glycerin with ethanol in an 8.8 ratio allowed for growing flame stability, also accentuated by creating swirl currents in the flame through the speed regime of fluids at the exit from the burner body. Results were excellent in both the flame stability and low level of polluting emissions. Full article

This differential extraction protocol details the steps for isolating DNA from sample pads used in lateral flow immunochromatographic (LFI) tests, particularly for cases involving mixed biological samples such as semen and menstrual blood, or other evidence related to sexual assault. This procedure utilizes a differential extraction technique applied to sample pads from immunochromatographic tests, where the sample pads serve as the substrate. The method involves two sequential lysis steps to effectively separate non-sperm and sperm fractions, enabling the targeted isolation of distinct cell types for downstream DNA analysis. The efficiency of this procedure is demonstrated by the results within this paper, which highlights the successful recovery of both male autosomal and Y-STR profiles, even in mixed samples with a high female presence. Overall, this protocol demonstrates the effective recovery of DNA from sample pads, which is beneficial for forensic practitioners dealing with limited sample quantities, underscoring the value of using these pads in forensic analysis. Full article

Extrarenal teratoid Wilms’ tumor (TWT) is a variant of Wilms’ tumor with fewer than 30 cases reported in the literature. It comprises more than 50% heterologous tissue and presents a significant diagnostic challenge due to its complex histology. We report an unusual case of mediastinal teratoma with nephroblastomatous elements in an 8-year-old female. The patient presented with respiratory distress, fever, weight loss, and a large anterior mediastinal mass. Imaging revealed a heterogeneous tumor containing fat, fluid, and calcification, suggestive of a teratoma. Surgical resection confirmed a mature cystic teratoma with foci of nephroblastoma. Pathological analysis demonstrated a mixture of ectodermal, mesodermal, and endodermal tissues alongside nephroblastomatous components. Immunohistochemistry was positive for Wilms Tumor 1 and other relevant markers, confirming the diagnosis. The patient had an uneventful postoperative course and was discharged after three days. This case adds to the growing body of research on extrarenal TWT, particularly its occurrence in the mediastinum, a rare site for such tumors. A literature review highlighted that extrarenal TWT often affects children, typically presenting in the retroperitoneum or sacrococcygeal regions, with varying recurrence rates and long-term outcomes. This case underscores the importance of histopathological and immunohistochemical analysis in diagnosing TWT and differentiating it from other mediastinal tumors to ensure appropriate treatment planning, emphasizing the need for long-term follow-up due to the potential for recurrence or metastasis. This paper also provides an in-depth look at nephron development and nephrogenic rests, highlighting the structural and functional aspects of nephrogenesis and the factors that disrupt it in fetal kidneys. Full article

Magnesium (Mg) has attracted considerable attention as a biodegradable material for medical implants owing to its excellent biocompatibility, mitigating long-term toxicity and stress shielding. Nevertheless, challenges arise from its rapid degradation and low corrosion resistance under physiological conditions. To overcome these challenges, titanium (biocompatibility and corrosion resistance) has been integrated into Mg. The incorporation of titanium significantly improves mechanical and corrosion resistance properties, thereby enhancing performance in biological settings. Mg–Ti alloys are produced through mechanical alloying and spark plasma sintering (SPS). The SPS technique transforms powder mixtures into bulk materials while preserving structural integrity, resulting in enhanced corrosion resistance, particularly Mg80-Ti20 alloy in simulated body fluids. Moreover, Mg–Ti alloy revealed no more toxicity when assessed on pre-osteoblastic cells. Furthermore, the ability of Mg–Ti-based alloy to create composites with polymers such as PLGA (polylactic-co-glycolic acid) widen their biomedical applications by regulating degradation and ensuring pH stability. These alloys promote temporary orthopaedic implants, offering initial load-bearing capacity during the healing process of fractures without requiring a second surgery for removal. To address scalability constraints, further research is necessary to investigate additional consolidation methods beyond SPS. It is essential to evaluate the relationship between corrosion and mechanical loading to confirm their adequacy in physiological environments. This review article highlights the importance of mechanical characterization and corrosion evaluation of Mg–Ti alloys, reinforcing their applicability in fracture fixation and various biomedical implants. Full article

A catheter is a device that is inserted into the venous system to infuse treatment with controlled doses per unit of time. The study of its interaction with blood flow cannot be easily analysed with common analytical methods or different visualization techniques in real life. Computational Fluid Dynamics has become a very useful tool in a wide variety of fields of scientific study and has allowed access to the understanding of the anatomical and physiological functioning of the human body. In this work, Computational Fluid Dynamics is used to study the effects of inserting a catheter on blood flow and the quality of the mixture of blood with the various substances infused through this device. Results show that the insertion of the catheter not only does not worsen the blood circulation but improves it by reducing stagnant zones. Regarding mixture, a homogenization of the fluids in the venous area before their entrance to the heart was observed. Highest quality mixtures correspond to fewer infused fluids and at lower velocity. Full article

We conducted a numerical study of the effects of a vortex generator (VG) on the combustion characteristics and physical fluid flow of LPG on a porous bluff-body slot burner (PBSB) model, validating the numerical and experimental results of the temperature distribution and mixture flow velocity. The VG position (fuel (F) and air (A) slots), direction (clockwise, CW, and counterclockwise, CCW), aspect ratio (AR), and distance (S) were investigated parametrically in our porous vortex generator slot burner (PVGSB) model. According to our results, the VGSB model with a VG angle of 60°, CW direction, aspect ratio of 0.4, and VG distance of 0 mm enhanced the flame temperature by 24.4% due to a greater vortex influence. Moreover, applying a reverse triangular bluff body to the VGSB model had a stronger effect on the vortices and swirl flow of the mixture compared to the cylindrical bluff body, achieving 34.9% higher combustion temperatures compared to the referenced PBSB model. This numerical study of using LPG combustion on a slot burner with VGs and a reverse triangular bluff body, which we refer to as the VGSB model, could be applied to enhancing physical air–fuel flow and the flame temperature as characteristics of combustion. Full article

Hybrid scaffolds that are based on PLA and PLA/PMMA with 75/25, 50/50, and 25/75 weight ratios and functionalized with 10 wt.% of bioglass nanoparticles (n-BG) were developed using an electrospinning technique with a chloroform/dimethylformamide mixture in a 9:1 ratio for bone tissue engineering applications. Neat PLA and PLA/PMMA hybrid scaffolds were developed successfully through a (CF/DMF) solvent system, obtaining a random fiber deposition that generated a porous structure with pore interconnectivity. However, with the solvent system used, it was not possible to generate fibers in the case of the neat PMMA sample. With the increase in the amount of PMMA in PLA/PMMA ratios, the fiber diameter of hybrid scaffolds decreases, and the defects (beads) in the fiber structure increase; these beads are associated with a nanoparticle agglomeration, that could be related to a low interaction between n-BG and the polymer matrix. The Young’s modulus of PLA/PMMA/n-BG decreases by 34 and 80%, indicating more flexible behavior compared to neat PLA. The PLA/PMMA/n-BG scaffolds showed a bioactive property related to the presence of hydroxyapatite crystals in the fiber surface after 28 days of immersion in a Simulated Body Fluids solution (SBF). In addition, the hydrolytic degradation process of PLA/PMMA/n-BG, analyzed after 35 days of immersion in a phosphate-buffered saline solution (PBS), was less than that of the pure PLA. The in vitro analysis using an HBOF-1.19 cell line indicated that the PLA/PMMA/n-BG scaffold showed good cell viability and was able to promote cell proliferation after 7 days. On the other hand, the in vivo biocompatibility evaluated via a subdermal model in BALC male mice corroborated the good behavior of the scaffolds in avoiding the generation of a cytotoxic effect and being able to enhance the healing process, suggesting that the materials are suitable for potential applications in tissue engineering. Full article

In recent years, polyelectrolytes have been successfully used as an alternative to non-collagenous proteins to promote interfibrillar biomineralization, to reproduce the spatial intercalation of mineral phases among collagen fibrils, and to design bioinspired scaffolds for hard tissue regeneration. Herein, hybrid nanofibers were fabricated via electrospinning, by using a mixture of Poly ɛ-caprolactone (PCL) and cationic cellulose derivatives, i.e., cellulose-bearing imidazolium tosylate (CIMD). The obtained fibers were self-assembled with Sodium Alginate (SA) by polyelectrolyte interactions with CIMD onto the fiber surface and, then, treated with simulated body fluid (SBF) to promote the precipitation of calcium phosphate (CaP) deposits. FTIR analysis confirmed the presence of SA and CaP, while SEM equipped with EDX analysis mapped the calcium phosphate constituent elements, estimating an average Ca/P ratio of about 1.33—falling in the range of biological apatites. Moreover, in vitro studies have confirmed the good response of mesenchymal cells (hMSCs) on biomineralized samples, since day 3, with a significant improvement in the presence of SA, due to the interaction of SA with CaP deposits. More interestingly, after a decay of metabolic activity on day 7, a relevant increase in cell proliferation can be recognized, in agreement with the beginning of the differentiation phase, confirmed by ALP results. Antibacterial tests performed by using different bacteria populations confirmed that nanofibers with an SA-CIMD complex show an optimal inhibitory response against S. mutans, S. aureus, and E. coli, with no significant decay due to the effect of CaP, in comparison with non-biomineralized controls. All these data suggest a promising use of these biomineralized fibers as bioinspired membranes with efficient antimicrobial and osteoconductive cues suitable to support bone healing/regeneration. Full article

Inorganic–organic hybrid biomaterials have been proposed for bone tissue repair, with improved mechanical flexibility compared with scaffolds fabricated from bioceramics. However, obtaining hybrids with osteoinductive properties equivalent to those of bioceramics is still a challenge. In this work, we present for the first time the synthesis of a class II hybrid modified with bioactive glass nanoparticles (nBGs) with osteoinductive properties. The nanocomposite hybrids were produced by incorporating nBGs in situ into a polytetrahydrofuran (PTHF) and silica (SiO₂) hybrid synthesis mixture using a combined sol–gel and cationic polymerization method. nBGs ~80 nm in size were synthesized using the sol–gel technique. The structure, composition, morphology, and mechanical properties of the resulting materials were characterized using ATR-FTIR, ²⁹Si MAS NMR, SEM-EDX, AFM, TGA, DSC, mechanical, and DMA testing. The in vitro bioactivity and degradability of the hybrids were assessed in simulated body fluid (SBF) and PBS, respectively. Cytocompatibility with mesenchymal stem cells was assessed using MTS and cell adhesion assays. Osteogenic differentiation was determined using the alkaline phosphatase activity (ALP), as well as the gene expression of Runx2 and Osterix markers. Hybrids loaded with 5, 10, and 15% of nBGs retained the mechanical flexibility of the PTHF–SiO₂ matrix and improved its ability to promote the formation of bone-like apatite in SBF. The nBGs did not impair cell viability, increased the ALP activity, and upregulated the expression of Runx2 and Osterix. These results demonstrate that nBGs are an effective osteoinductive nanoadditive for the production of class II hybrid materials with enhanced properties for bone tissue regeneration. Full article