Spherical Shape Research Articles

Digital light processing three-dimensional printing with acrylic–titanium composite powders for multiscale porous scaffolds

Abstract Porous metals fabricated via three-dimensional (3D) printing have attracted extensive attention in many fields owing to their open pores and customization potential. However, dense internal structures produced by the powder bed fusion technique fails to meet the feature of porous materials in scenarios that demand large specific surface areas. Herein, we propose a strategy for 3D printing of titanium scaffolds featuring multiscale porous internal structures via powder modification and digital light processing (DLP). After modification, the titanium powders were composited with acrylic resin and maintained spherical shapes. Compared with the raw powder slurries, the modified powder slurries exhibited higher stability and preferable curing characteristics, and the depth sensitivity of the modified powder slurries with 45 vol% solid loading increased by approximately 72%. Green scaffolds were subsequently printed from the slurries with a solid loading reaching 45 vol% via DLP 3D printing. The scaffolds had macropores (pore diameters of approximately 1 mm) and internal open micropores (pore diameters of approximately 5.7–13.0 μm) after sintering. Additionally, these small-featured (approximately 320 μm) scaffolds retained sufficient compressive strength ((70.01 ± 3.53) MPa) even with high porosity (approximately 73.95%). This work can facilitate the fabrication of multiscale porous metal scaffolds with high solid loading slurries, offering potential for applications requiring high specific surface area ratios.

FREE VIBRATION ANALYSIS IN INNOVATIVE 3D PRINTING SANDWICH PANAELS FOR AIRCRAFT STRUCTURE

Sandwich panel structures are composed of three layers: core and two facings. The configuration of the core deeply influences the mechanical properties of the sandwich panel. Numerous innovative core shapes have been proposed to enhance these properties; however, many have not been implemented due to manufacturing difficulties, particularly spherical shapes. This research aims to address this manufacturing challenge by utilizing 3D printing technology to produce sandwich panels with a spherical core. Additionally, the study investigates the effects of varying design parameters like sphere diameter, offset distance and face thickness on the free vibration features of the sandwich panels experimentally and numerically. Experimental tests validated the finite element models with an error margin below 12%. The key parameters explored were spherical diameter (3-12mm), offset distance (10-33mm), and face thickness (1-5mm). The results demonstrate a direct correlation between these parameters and the sandwich beam natural frequency.

Enhanced properties of (TaNbTiV)C high‐entropy carbide ceramics through controlled structure and morphology of high‐entropy carbide powders

AbstractSubmicron high‐entropy carbide (HEC) (TaNbTiV)C powders with various morphologies and properties were prepared using the molten salt method by adjusting structures and graphitization of carbon sources. Subsequently, the HEC ceramics were sintered at 1900°C using spark plasma sintering. Compared to traditional carbon sources (carbon black and flake graphite), powders synthesized using graphitic carbon microspheres with a spherical shape exhibited a smaller particle size of 0.45 µm, a larger specific surface area of 14.46 m2/g, and a larger lattice constant of 0.4451 nm. Moreover, the HEC powders prepared using graphitic carbon microspheres enhanced the sintering of the HEC matrix, leading to improved mechanical properties and oxidation resistance of the HEC ceramics compared to those prepared using other carbon sources. Unlike the precursor method used to adjust the HEC powder structure, the molten salt method is a low‐cost and straightforward approach to regulating the HEC powder structure by controlling the structure of raw material.

Synthesis and Characterization of Lignocellulose-Based Carbon Quantum Dots (CQDs) and Their Antimicrobial and Antioxidant Functionalities

Carbon quantum dots (CQDs) have recently drawn enormous attention due to not only their unique chemical, biological, and optical properties but also because a variety of renewable biomasses are readily utilized as carbon sources in their synthesis. This study investigated the synthesis, characterization, and functional evaluation of CQDs from unbleached mechanical pulp as a natural lignocellulosic resource. The CQDs were synthesized using a one-step hydrothermal synthesis with varying temperature, time, and pulp consistency. The resulting CQDs exhibit a spherical shape with a size distribution of 9.73 ± 0.82 nm and lattice parameters of 0.21 and 0.34 nm, indicating a graphite core. The photoluminescence spectra showed evident fluorescence characteristics, with an emission peak at 435 nm at an excitation wavelength of 370 nm. The as-prepared CQDs were also chemically composed of C=C and C=O bonds linked to the hydroxyl and carboxyl functional groups, which are typically found in lignocellulose-based CQDs. The CQDs demonstrated antibacterial activity exceeding 99.9% against E. coli at the lowest concentration of 0.75 mg/mL. Demonstrating its antioxidation property, the DPPH radical scavenging activity surpassed 90% with more than 40 µg/mL of the CQD solution.

Green synthesized silicon dioxide nanoparticles (SiO2NPs) ameliorated the cadmium toxicity in melon by regulating antioxidant enzymes activity and stress-related genes expression

Green synthesized nanoparticles (NPs) are an eco-friendly and cost-effective approach to reduce heavy metal stress in plants. Among heavy metals, cadmium (Cd) possesses higher toxicity to the crops and ultimately reduces their growth and yield. The current study aims to evaluate the effectiveness of green synthesized SiO2NPs to reduce toxic effects of Cd in melon (Cucumis melo) by regulating physiological parameters, enhancing antioxidant enzyme activity, and modulating stress-related gene expression. The SiO2NPs were synthesized using Artemisia annua plant extract having spherical shape and size within the range of 40-70 nm and characterized using advanced spectroscopic and analytical techniques. The application of SiO2NPs (75mg/L) significantly improved physiological parameters such as shoot length (SL), root length (RL), leaf fresh weight (LFW), root fresh weight (RFW), leaf dry weight (LDW) and root dry weight (RDW) by 14%, 20%, 15%, 16%, 14%, and 28%, respectively, compared to Cd-stressed plants. Photosynthetic pigments (chlorophyll and carotenoids) showed a notable increase of 15% and 40%, respectively. Furthermore, the activities of antioxidant enzymes such as SOD, POD, CAT, and APX were enhanced by 28.67%, 35.45%, 32.07%, and 42.75%, respectively. In addition, applying SiO2NPs increased the concentration of macronutrients N, P, and K by 33%, 40%, and 37%, respectively, compared to Cd-stressed plants. Moreover, SiO2NPs upregulated the expression of several stress-related genes and reduced Cd accumulation in shoots and roots. This study reveals that green synthesized SiO2NPs effectively reduced the Cd toxicity in melon by improving morphological and physiological parameters, enhancing antioxidant enzyme activity, and regulating the expression of stress-related genes. These findings suggest that green synthesized SiO2NPs could play a crucial role in sustainable agriculture by protecting crops from heavy metal stress.

Therapeutic Effects of Crocin Nanoparticles Alone or in Combination with Doxorubicin against Hepatocellular Carcinoma In vitro.

Crocin (CRO), the primary antioxidant in saffron, is known for its anticancer properties. However, its effectiveness in topical therapy is limited due to low bioavailability, poor absorption, and low physicochemical stability. This study aimed to prepare crocin nanoparticles (CRO-NPs) to enhance their pharmaceutical efficacy and evaluate the synergistic effects of Cro-NPs with doxorubicin (DOX) chemotherapy on two cell lines: human hepatocellular carcinoma cells (HepG2) and non-cancerous cells (WI38). CRO-NPs were prepared using the emulsion diffusion technique and characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Zeta potential, and Fourier transform infrared spectroscopy (FT-IR). Cell proliferation inhibition was assessed using the MTT assay for DOX, CRO, CRO-NPs, and DOX+CRO-NPs. Apoptosis and cell cycle were evaluated by flow cytometry, and changes in the expression of apoptotic gene (P53) and autophagic genes (ATG5 & LC3) were analyzed using real-time polymerase chain reaction. TEM and SEM revealed that CRO-NPs exhibited a relatively spherical shape with an average size of 9.3 nm, and zeta potential analysis indicated better stability of CRO-NPs compared to native CRO. Significantly higher antitumor effects of CRO-NPs were observed against HepG2 cells (IC50 = 1.1 mg/ml and 0.57 mg/ml) compared to native CRO (IC50 = 6.1 mg/ml and 3.2 mg/ml) after 24 and 48 hours, respectively. Annexin-V assay on HepG2 cells indicated increased apoptotic rates across all treatments, with the highest percentage observed in CRO-NPs, accompanied by cell cycle arrest at the G2/M phase. Furthermore, gene expression analysis showed upregulation of P53, ATG5, and LC3 genes in DOX/CRO-NPs co-treatment compared to individual treatments. In contrast, WI38 cells exhibited greater sensitivity to DOX toxicity but showed no adverse response to CRONPs. Although more in vivo studies in animal models are required to corroborate these results, our findings suggest that CRO-NPs can be a potential new anticancer agent for hepatocellular carcinoma. Moreover, they have a synergistic effect with DOX against HepG2 cells and mitigate the toxicity of DOX on normal WI38 cells.

Analysing the apoptotic potential of green synthesized Nyctanthes arbor-tristis chitosan nanoparticles in MDA-MB-231 and SKOV3 cell lines

Gynecological tumors are highly aggressive cancers in women, often treated with conventional treatments that can cause significant side effects. This study focuses on the preparation of chitosan nanoparticles from Nyctanthes arbor-tristis leaves, which possess anti-tumor properties, to address and overcome these issues. The successfully synthesized nanoparticles were characterized by UV-spectroscopy, DLS, TEM, and FTIR spectroscopy to analyze their physiochemical properties. In vitro studies, including cytotoxicity and scratch wound healing assays, along with staining and qRT-PCR, revealed the nanoparticles' anticancer efficacy against breast and ovarian cancer cells. The formation of Nat-CSNPs showed an absorbance peak at 221nm, a particle size range of 41-56nm with a spherical shape, polydispersity, and a positive surface charge. FTIR spectroscopy demonstrated the presence of functional groups associated with the synthesized Nat-CSNPs. It exhibited dose-dependent cytotoxicity, with IC50 values of 62.40μg/ml for MDA-MB-231 and 44.7μg/ml for SKOV3 cells. Further assays such as wound healing assay, and DAPI/AO/EtBr staining demonstrated their antiproliferative and apoptotic effects on MDA-MB-231 and SKOV3 cells. Induction of apoptosis by the chitosan-nanoparticle via upregulation of the pro-apoptotic genes (Bax, Cas3, Cas9) and downregulation of antiapoptotic genes (Bcl2) was assessed using qRT-PCR analysis. In vivo acute toxicity assessments of Nat-CSNPs on Danio rerio revealed no significant impact on glucose levels or AST, ALT, and AChE activity, indicating low toxicity. These findings underscore the potent anticancer effects of Nat-CSNPs, particularly inducing apoptosis in MDA-MB-231 and SKOV3 cell lines. While demonstrating low toxicity in Danio rerio, Nat-CSNPs are considered a promising novel anti-cancer drug for breast and ovarian cancer treatment.

Hyaluronic acid functionalized liposomes for co-delivery of paclitaxel and ursolic acid for enhanced efficacy against triple negative breast cancer

Triple negative breast cancer (TNBC) stands out as an aggressive and lethal subtype of breast cancer. Despite being a mainstay in treatment, the efficacy of paclitaxel (PTX) diminishes due to significant tumor heterogeneity and emergence of drug resistance. Combination drug therapy stands out as the foremost strategy for addressing these limitations. Therefore, the current study aimed to develop hyaluronic acid (HA) modified liposomes for tumor targeted co-delivery of PTX with UA, a phytocompound with potent antitumor properties, with the goal of achieving an enhanced chemotherapeutic response. The PTX and UA co-loaded cationic liposomes (PTX/UA-Cat-Lip) were prepared via thin film hydration using Leciva S90:DOTAP:cholesterol (5:3:2 molar ratio), followed by HA coating through electrostatic interactions. The PTX/UA-HA-Lip exhibited a spherical shape, a particle size of 108 nm, a PDI of 0.27, and a zeta potential of -14.5 mV, with encapsulation efficiency of 82.56% for PTX and 77.27% for UA. These liposomes exhibited biphasic drug release, with cumulative PTX and UA release of 79.66% and 73.26%, respectively, over 72 h. The PTX/UA-HA-Lip demonstrated enhanced cellular uptake in MDA-MB-231 and 4T1 cells attributed to HA-CD44 interaction. PTX/UA-HA-Lip showed lower IC50 value, higher apoptotic index, increased ROS generation, and mitochondrial depolarization in MDA-MB-231 and 4T1 cells. In vivo, PTX/UA-HA-Lip demonstrated 2.28- and 2.54-fold higher AUC, 2.79- and 3.69-fold longer t1/2, and 2.55- and 3.36-fold longer MRT compared to free PTX and UA, respectively, with significant tumor volume reduction in the 4T1-based TNBC model. Toxicity assessment revealed no significant elevation in serum toxicity biomarkers and no observable damage to the body organs, demonstrating its safety.

Synthesis of BODIPYs using organoindium reagents and survey of their cytotoxicity and cell uptake on nervous system cells.

In this study, a series of BODIPY dyes were synthesized, containing various substituents at meso position. Further functionalization of the BODIPY framework at C2 and C2-C6 position(s) by palladium-catalysed cross-coupling reactions using organoindium reagents (R3In) was efficiently assessed, starting from C2(6)-halogenated BODIPYs, and their optical properties were measured. The cytotoxicity of BODIPY dyes on SH-SY5Y neuronal cells by MTT assay showed that those compounds bearing thien-2-yl and benzonitrile moieties at meso position, exhibited great efficiency in maintaining cell viability under all tested conditions (up to 50µM for 24h and 48h). Furthermore, nanoliposomal encapsulation of a hydrophobic BODIPY, incorporating bis(trifluoromethyl)phenyl substituents at C2 and C6 positions, through the lipid-extrusion method was addressed. The liposomes exhibited spherical shape as observed in cryo-TEM image, with average particle size of 120nm (average PdI 0.05) and Zeta potential 54.69mV by DLS measurements. Simple incubation of gliobastoma U-87 cells with prepared liposomes led to efficient internalization, and visualization of brightness BODIPY in cytoplasm using fluorescence confocal microscopy, demonstrating encapsulation enhance biocompatibility of the hydrophobic BODIPY as preliminary approximation for further biomedical applications.

Enhanced solubility, stability, bioaccessibility, and antioxidant activity of curcumin with hydrolyzed pea protein-based nano-micelles: pH-driven method vs ethanol-induced method.

Pea protein nano-micelles gained with partial hydrolysis by a proteolytic enzyme (Protamex) were employed as nanocarriers to encapsulate and stabilize liable and hydrophobic curcumin (CUR) with two various methods (pH-driven method (PDM) and ethanol-induced method (EIM)). Both CUR-loaded pea protein hydrolysates (PPHs) nano-micelles by PDM and EIM exhibited spherical shapes, and uniform particle size distributions. Highest CUR loading amount (3.21%) was gained with PPHs by PDM. The interaction between PPHs nano-micelles and curcumin was comprehensively examined with optical spectroscopy. These outcomes obviously demonstrated the water solubility, storage stability against UV light and heating, bioaccessibility and in vitro antioxidant activity of CUR can be pronouncedly enhanced with PPHs-based nanocarriers. Interestingly, PPHs-CUR nano-micelles fabricated with PDM have higher loading amount, light stability, and better bioaccessibility as well as antioxidant activity than those by EIM. These results clearly show that PDM may be a better method than EIM and provide useful information in nutraceuticals encapsulation with vegetable proteins-based delivery systems.

Optimization of invasomal gel of miconazole nitrate for the treatment of topical fungal infections

The treatment of deep topical fungal infections poses considerable obstacles. Miconazole nitrate which is used in the management of fungal infections has limited effectiveness owing to its poor aqueous solubility. The current study focuses on the improvement of solubility and permeability of miconazole nitrate through the skin by loading it into invasomes composed of soy lecithin and cilantro oil. The effects of varying amounts of soy lecithin and cilantro oil as independent variables was studied on entrapment efficiency and drug diffusion in-vitro by using the central composite design. An optimized formulation comprising of 104 mg of soy lecithin and 0.8 mL of cilantro oil was prepared and evaluated. Further, it was loaded into a gel base and evaluated for texture analysis, antifungal activity, in-vitro and ex-vivo drug diffusion. The entrapment efficiency and in-vitro drug diffusion for different formulations ranged from 84 ± 0.82 to 90 ± 0.74 % and 56.96 ± 1.51 to 86.3 ± 1.23 % respectively. Entrapment efficiency and in-vitro drug diffusion of optimized formulation were 85 ± 2.19 and 88.15 ± 1.57 % respectively. Particle size, zeta potential and polydispersity index of optimized formulation were 138.4 ± 2.25 nm, -45 ± 1.21 mV and 0.254 ± 0.12. The spherical shape of vesicles was confirmed by scanning electron microscopy. DSC thermogram revealed a partial conversion of crystalline to partial amorphous form of the drug due to encapsulation in a lipid matrix. The in-vitro and ex-vivo drug diffusion from invasomal gel was 88.15 ± 1.28 % and 77.9 ± 1.8 %, respectively. The in-vitro antifungal assay revealed that the invasomal gel exhibited a 1.5-fold increase in antifungal efficacy against Candida albicans compared to miconazole nitrate. This could be result of enhanced solubility, better drug diffusion and presence of cilantro oil. The results were conclusive of the enhanced effectiveness of miconazole nitrate in treating fungal infections by formulating it into invasomal gel formulation.

Development of Novel Piperine-Loaded Mesoporous Silica Nanoparticles: Enhanced Drug Delivery and Comprehensive In Vivo Safety Analysis.

Piperine-loaded mesophorous silica nanoparticles (MSNPs) were synthesized by chemical methods from tetraethylorthosilicate (TEOS) as a precursor, N-Cetyl Trimethyl Ammonium Bromide (CTAB) as a surfactant, piperine, distilled water, and sodium hydroxide (NaOH) as a catalyst at 80 °C. After stirring the mixture for 20 to 30 minutes, the synthesized combined substances were washed with ethanol and the surfactant was removed using hydrochloric acid (HCl). The morphological characterization was assessed by High Resolution-Transmission Electron Microscope (HR-TEM), scanning electron microscopy (FE-SEM), FESEM-EDX, infrared Fourier transform spectroscopic (FTIR), X-ray diffractometer (XRD), Dynamic Light Scattering (DLS) and UV-VIS. HR-TEM final report showed the amorphous nature of the prepared NPs. TEM image at 100 nm, showed typical ball-like geometry with an average particle size of 13.05 nm. FE-SEM analysis proved that mesoporous silica nanoparticles loaded with piperine have a spherical shape with various nm ranges starting from 232 to 552 nm. The results of the piperine release test observed 93.70% of the drug (piperine) over 24 hours. The in vivo toxicity analysis of piperine-loaded MSNPs tested using adult zebrafish showed no toxic effect. Our developed piperine-loaded mesophorous silica nanoparticles (MSNPs) are favorable for achieving sustained release, a lower dose frequency, and better therapeutic effects.

Luminescent carbon dots structure by charcoal laser ablation in biocompatible liquid

Nanometric Carbon dots (CDs) were synthesized using the laser ablation of vegetable carbon placed in a liquid. A pulsed diode laser operating at a 970 nm wavelength was employed to irradiate a charcoal target placed in a phosphate-buffered saline (PBS) solution with neutral pH. The laser radiation induces carbon ablation and exfoliation, with an ablation yield of the order of 5 ng/laser pulse. Small carbon dots and larger carbon nanoparticles were synthesized in the solution. A 365 nm UV lamp irradiation of the CDs dispersion induces visible luminescence emission at about 478 nm wavelength, with a typical blue-green color. UV-Visible-NIR and FTIR spectroscopies have permitted to evaluation of the dispersion liquid transmittance and absorbance. TEM microscopy has evinced that the synthesized CDs are crystalline with a spherical shape and an average size of the order of 1.5 nm. The CD’s properties in terms of luminescence and quantum yield in the biocompatible dispersion are presented and discussed for advanced possible applications to the biological and medical fields.

Technological and Functional Potentialities of Mairá (Casimirella rupestris) and Ariá (Goeppertia allouia) Starches.

The Amazon region holds untapped potential with its starch-rich tubers, which are not yet industrialized and face a risk of extinction due to competition from widely cultivated crops. Beyond their traditional subsistence use, Amazonian tubers such as Mairá and Ariá can be utilized as starch sources, offering an opportunity to support regional agriculture, preserve indigenous heritage, and provide sustainable income streams. This study aimed to characterize starches extracted from Mairá (MPS) and Ariá (ARS for rhizome and APS for potato), focusing on their technological and functional potential. Following extraction (maceration, filtration, decantation, and drying), their structure and size were analyzed using SEM and optical microscopy. Amylose content was determined spectrophotometrically, while pasting and thermal properties were assessed using RVA and DSC techniques. They exhibited axial diameters of 18.9, 22.6, and 26.7μm, with MPS, ARS, and APS displaying spherical, elliptical, and polygonal shapes, respectively. According to RVA results, MPS showed lower viscosity and paste stability compared to others, making it more suitable for products requiring minimal thickening. Ariá starches demonstrated a rapid retrogradation and the formation of opaque pastes, indicating potential applications in products requiring these characteristics. Starches from these Amazonian tubers present significant potential as thickening and gelling agents for the food industry, standing out for their safety in consumption and their role in preserving endangered species.

Synthesis of chitosan/PVA/copper oxide nanocomposite using Anacardium occidentale extract and evaluating its antioxidant, antibacterial, anti-inflammatory and cytotoxic activities

Nanotechnology has witnessed remarkable advancements in recent years, capturing considerable attention in diverse biomedical applications. Using the green precipitation method, this study aims to synthesize and characterize chitosan/polyvinyl alcohol-copper oxide nanocomposites (CS/PVA/CuONCs) using Anacardium occidentale plant fruit extract. The CS/PVA/CuONCs were further evaluated in antioxidant, antibacterial and biological activities. In our study results, UV–Vis spectrum analysis of CS/PVA/CuONCs revealed a peak at 430 nm. FTIR analyses confirmed the presence of different functional groups, while the XRD study confirmed the crystalline structure of the synthesized nanocomposites. FESEM-EDAX analysis demonstrated that the CS/PVA/CuONCs exhibited a spherical and rod-like shape, with an average particle size of 48.6 to 96.2 nm. Notably, CS/PVA/CuONCs exhibited higher antioxidant activity, as evidenced by their ABTS activity (83.79 ± 1.57%) and SOD activity (86.17 ± 1.28%). In antibacterial assays, CS/PVA/CuONCs demonstrated inhibition in Escherichia coli at 20.52 ± 0.85 mm and Bacillus subtilis at 19.64 ± 0.87 mm, displaying a zone of inhibition. The CS/PVA/CuONCs exhibited excellent anti-inflammatory potency against COX-1 (67.10 ± 0.58%) and COX-2 (76.39 ± 0.65%). The antidiabetic assay revealed excellent α-amylase inhibition (80.25 ± 1.29%) and α-glucosidase inhibition (84.74 ± 1.42%) activities. Anti-cholinergic activity of AChE was 65.35 ± 0.98% and BuChE was 82.46 ± 1.15% are observed. CS/PVA/CuONCs was shown to have strong cytotoxicity against MCF-7 cell lines. It also had the highest cell viability inhibition, at 13.66 ± 0.58%. The hemolysis activity was found to be 5.38 ± 0.34%. Overall, the study demonstrated that CS/PVA/CuONCs possess remarkably excellent biological activities.

Green synthesis of highly luminous lemon juice-based carbon dots for antimicrobial assessment and fingerprint detection

Abstract Carbon dots are regarded as a brand new class of nanostructures in the carbonaceous family that have piqued the curiosity of researchers in a wide range of bio applications. This work focuses on the synthesis and characterization of carbon dots, as well as their latent fingerprint detection and antibacterial/antifungal capabilities. Highly luminous carbon dots were prepared by optimizing simple hydrothermal carbonization settings at 180 °C for 12 h using lemon juice as a raw precursor. The resulting product was examined using Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffractometery, and ultraviolet–visible spectrophotometer. The as-prepared carbon dots were found to be extremely bright when excited under ultraviolet light (λ = 365 nm). The presence of carbon and oxygen functionalities on the surface of the carbon dots was revealed by infrared spectrocopy. The diffraction pattern confirmed the amorphous structure of the carbon dots, with an average size of 7 nm determined using the Scherrer equation. The surface morphology analysis revealed that the carbon dots exhibited an aggregated form with irregular spherical shapes. The chemical structure examination validated the elemental makeup of the prepared lemon juice-based carbon dots. The detection of latent fingerprints on carbon dots under ultraviolet light yielded positive results. In addition, the obtained carbon dots displayed antifungal and antibacterial activity against tested pathogenic fungal and bacterial strains.

Pd nanocatalyst supported on chitosan–waste oil microspheres for efficient degradation of industrial pollutants in water

Abstract Disposal of industrial pollutants is one of the most important working topics today. Pd–doped catalysts have high efficiency in the degradation of many organic pollutants. Within the scope of this study, waste engine oil (WEO) was used as activated carbon (AC) source and then AC was encapsulated with chitosan (CS) to prepared chitosan–based microbeads (CS/WEO AC) for catalyst support. After treatment with glyoxal as cross–linker, Pd nanoparticles with spherical shape and 16.8 nm diameter were decorated on the microbeads (Pd@CS/WEO AC). Efficiency of Pd@CS/WEO AC on the reduction of 4-nitrophenol (4-NP), 4-nitro-o-phenylenediamine (4-NPDA), 2-nitroaniline (2-NA), 4-nitroaniline (4-NA) as nitroarens; methylene blue (MB), methyl orange (MO), and rhodamine B (RhB) as organic dyes; Cr(VI) and K3[Fe(CN)6] was examined in aqueous media. Developed Pd@CS/WEO AC nanocatalyst reduced nitroarenes, organic dyes, Cr(VI) and K3[Fe(CN)6] in very short times (0–130 s). Based on kinetic studies, the rate constants for Pd@CS/WEO AC–catalyzed reduction reactions of 2–NA, 4–NP, 4–NA, 4–NPDA, MO, RhB, [Fe(CN)6]3⁻, and Cr(VI) were found to be 0.018 s−1, 0.007 s−1, 0.026 s−1, 0.012 s−1, 0.021 s−1, 0.065 s−1, 0.048 s−1, and 0.042 s−1, respectively. Additionally, it was confirmed that Pd@CS/WEO AC is a long–lasting catalyst, as it was reused for five successive runs in the reduction of 4–NP. In this study, we aim to design new materials by modifying carbon–containing waste sources with biological macromolecules and investigate the possible applications of these materials to remove some pollutants from water sources.

Athletic shapeshifting of the right ventricle: 3D echocardiography-derived global and regional shape analysis in elite athletes

Abstract Intense physical activity poses marked hemodynamic strain on the right ventricle (RV), as during exercise, RV is subjected to a proportionally higher pressure and volume overload than its left counterpart. While the morphological changes of the left ventricle can be characterized using pre-defined reference shapes (cone and sphere), the complex structure of the RV cannot be captured similarly. Therefore, the exercise-induced changes in the RV's global and regional shape have not been directly investigated. Our aim was to develop a 3D echocardiography (3DE)-based method to quantify the global and regional shape metrics of the RV in a large cohort of elite athletes. Elite athletes (n=138) and healthy, sedentary volunteers (n=104) were enrolled and underwent 3DE to measure RV volumes and ejection fraction (EF). 3D RV endocardial mesh models were reconstructed at end-diastole and end-systole to quantify regional curvature indices along 5 clinically relevant parts of the RV (apex, septum, free-wall, outflow tract, and inflow tract). Zero curvature depicts a flat surface, whereas a more positive or negative curvature represents a more convex or concave surface, respectively. Regarding the RV’s global shape, hemi-conicity and hemi-sphericity indices were introduced (Figure 1). First, the longitudinal height of the 3D RV mesh was defined. To calculate hemi-sphericity index, a hemisphere (with a radius that is half the height of the RV mesh) was created. Then, the volume of this hemisphere and the volume of the RV mesh were compared (a higher volume ratio depicts a more spherical shape). To calculate hemi-conicity index, a half-cone (whose height equals the RV’s height and volume equals the RV mesh’s volume) was defined. Then, the angle at the top of the half-cone was evaluated (a more acute angle describes a more conical shape). As expected, athletes had higher RV end-diastolic (EDV; 165±36 vs. 146±44 ml, p<0.001) and end-systolic volumes (ESV; 75±22 vs. 65±23, p<0.005), whereas RV EF did not differ in the two groups. Regional curvature analysis showed that in athletes, the septum of the RV was significantly flatter (-0.4±9 vs. 6.7±7.7, p<0.001), along with the RV free-wall curvature index that also depicted a significantly flatter shape (57.9±8.3 vs. 61.2±7.7, p<0.001) compared to controls. The global shape assessment revealed that the RV of the athlete’s heart had a more conical shape, as the hemi-sphericity volume ratio was significantly lower (0.79±0.17 vs. 1.19±0.40, p<0.001), and the hemi-conicity angle exhibited a more acute angle (63.8± 5.7 vs. 74.1±9.1, p<0.001) both pointing towards a conical remodeling. The assessment of 3D echocardiography-derived regional and global shape metrics revealed a different, more conical geometry in the athletes’ RV. Our novel method may enable a more precise quantification of the RV's unique, exercise-induced geometrical remodeling. Figure 1

Validity of the left ventricular sphericity index in apical and basal aneurysms

Abstract Introduction Left ventricular aneurysm (LVA) correlates with changes in ventricular geometry related to the size and shape of the left ventricle (LV). On echocardiography it presents as global changes in the ventricle with reduced systolic function (ejection fraction - EF). Abnormal remodeling geometry of the ventricle leads to a more spherical shape and the manifestation of the spherity index (SI) as a parameter of abnormal geometric change (SI is the ratio of the short (S) to the long (L) axis of the heart measured from the apical four-chamber view). In healthy individuals and in ischemic dilated cardiomyopathy SI remains constant due to proportional enlargement of S and L. The aim of this study was to evaluate the value of SI in the presence of apical left ventricular aneurysm (A-LVA) and basal aneurysm (B-LVA) using echocardiography, to determine the parameters that can influence SI, and their significance in daily clinical practice. Material and Methods The clinical study included 54 patients with post-infarction LVA (36 men, 18 women). The localization of the LVA was determined by echocardiography. A-LVA was formed near the apex of the LV, while B-LVA was in the basal segments of the LV walls. SI was determined in systole and diastole in the entire population and stratified among patients with A-LVA and B-LVA. LV EF was determined by Simpson's method. Results Study included 41 patients with A-LVA and 13 with B-LVA. The average SI value in diastole was 0.55 and in systole 0.47. Patients with A-LVA had an average SI value in diastole of 0.51 and in systole 0.44. Significantly higher SI values were found in the presence of B-LVA, with diastolic SI at 0.65 and systolic SI at 0.57 compared to A-LVA. The reason is that the long axis (L) values of the heart in both diastole and systole are lower in B-LVA compared to A-LVA. LV EF in patients with A-LVA was 23.95%, and in B-LVA, it was 30.85%, with no significant difference. The difference in absolute values is due to apical aneurysms being larger compared to basal aneurysms, thus more significantly reducing the percentage of functional myocardium. Conclusion The results indicate that it is important to differentiate A-LVA and B-LVA by determining SI using echocardiography. SI is higher in B-LVA due to the reduction of the long axis (L). Surgical reconstruction of the left ventricle always addresses the reduction in length (L) compared to the reduction in width (S). Therefore, in surgical reshaping of the LV for B-LVA, it is crucial to maximally preserve the long axis (L) to maintain a more physiological shape.

Thermal Simulation of MnS Evolution in Solidification of a Low‐Carbon Alloy Steel Bloom

The continuous casting process of a newly developed low‐carbon alloy steel is simulated using a thermal simulation method to investigate the evolution of MnS inclusion. The results indicate that MnS mainly appears as aggregated small‐sized spherical shapes (type I MnS) in the chill zone of the bloom, while in columnar zone, it tends to form strip‐like or irregular morphologies (type II MnS), and no type III MnS is observed. The size of MnS increases from the surface to the center of the samples, with the maximum equivalent diameter increasing from 1.2 to 6.0 μm. A model, considering the effects of solute redistribution and cooling rate, is established to calculate the precipitation and growth of MnS in continuous casting bloom, which is achieved by coupling theoretical calculations with the discrete solidification units. The calculated results demonstrate that sulfur segregation is the controlling factor for the precipitation and growth of MnS, which are well consistent with experiments. This work suggests that enhancing the cooling rate in the secondary cooling zone or improving homogenization of this new low‐carbon alloy steel bloom can effectively reduce the growth rate of MnS and mitigate the formation of type II MnS.