Through Transmission Electron Microscopy Research Articles

Enhanced delivery of rivastigmine for Alzheimer's disease: Convolvulus pluricaulis lipid hybrid nanoparticles

The study investigates the formulation and characterization of polymeric lipid hybrid nanoparticles (PLHNs) for targeted delivery of Rivastigmine and Convolvulus pluricaulis (C. pluricaulis, Shankhpushpi) extract to the brain. Employing a modified film hydration technique, PLHNs were optimized by adjusting lipid-to-polymer ratios, achieving nanoparticles with optimal size, zeta potential, and entrapment efficiency. The resulting nanoparticles, with sizes between approximately 150–225 nm, exhibited excellent physical stability and encapsulation efficiencies. Characterization through transmission electron microscopy (TEM) and scanning electron microscopy (SEM) confirmed their spherical and smooth morphology. Fourier-transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) analyses showed no significant interactions between the drug, polymer, and plant extract, ensuring formulation stability. In vitro release studies demonstrated a controlled and sustained drug release, with the optimal formulation showing substantial release over 24 hours. The novel object recognition (NOR) test indicated enhanced cognitive function in animals treated with the optimal formulation, suggesting effective brain targeting and neuroprotective activity. Biochemical analyses supported these findings, revealing significant improvements in antioxidant enzyme levels and reductions in oxidative stress markers in treated animals. This study underscores the potential of PLHNs to enhance the delivery of neuroprotective agents, offering a promising strategy for treating neurodegenerative diseases.

Subendocardial ischemic-like state in patients with severe aortic stenosis: insights from myocardial histopathology and ultrastructure

Abstract Background myocardial adaptation to severe aortic stenosis (AS) is a complex process that involves myocardial fibrosis (MF) beyond cardiomyocyte hypertrophy. Perfusion impairment is believed to be involved in myocardial remodeling in chronic pressure overload. Aim to describe morphological and ultrastructural myocardial changes at EMB, possibly reflecting subendocardial ischemia, in a group of patients with severe AS referred to surgical aortic valve replacement (AVR), with no previous history of ischemic cardiomyopathy. Methods one-hundred-fifty-eight patients (73 [68-77] years, 50% women) referred for surgical AVR because of severe symptomatic AS with pre-operative clinical and imaging study and no previous history of ischemic cardiomyopathy. Intra-operative septal EMB was obtained in 129 patients. Tissue sections were stained with Masson ́s Trichrome for MF quantification and periodic acid-Schiff (PAS) staining was performed to assess the presence of intracellular glycogen. Ultrastructure was analyzed through Transmission electron microscopy (TEM). Results MF totalized a median fraction of 11.90% [6.54-19.97%] of EMB, with highly prevalent perivascular involvement (95.3%). None of the samples had histological evidence of myocardial infarction. In 58 patients (45%) we found subendocardial groups of cardiomyocytes with cytoplasmatic enlargement, vacuolization and myofiber derangement, surrounded by extensive interstitial fibrosis. These cardiomyocytes were PAS positive, PAS-diastase resistant and Alcian Blue/PAS indicative of the presence of neutral intracellular glyco-saccharides. At TEM there were signs of cardiomyocyte degeneration with sarcomere disorganization and reduction, organelle rarefaction but no signs of intracellular specific accumulation. Conclusion almost half of the patients with severe AS referred for surgical AVR have histological and ultrastructural signs of subendocardial cardiomyocyte ischemic insult. It might be inferred that local perfusion imbalance contributes to myocardial remodeling and fibrosis in chronic pressure overload.

Lhx6 deficiency causes human embryonic palatal mesenchymal cell mitophagy dysfunction in cleft palate

BackgroundOverconsumption of retinoic acid (RA) or its analogues/derivatives has been linked to severe craniomaxillofacial malformations, such as cleft palate and midface hypoplasia. It has been noted that RA disturbed the proliferation and migration of embryonic palatal mesenchymal (EPM) cells in these malformations, yet the exact mechanisms underlying these disruptions remained unclear.MethodsA model of retinoic acid (RA)-induced cleft palate in fetal mice was successfully established. Histological alterations in the palate were evaluated using Hematoxylin and Eosin (H&E) staining and RNA in situ hybridization (RNAscope). Cellular proliferation levels were quantified via the Cell Counting Kit-8 (CCK-8) assay and EdU incorporation assay, while cell migration capabilities were investigated using wound healing and Transwell assays. Mitochondrial functions were assessed through Mito-Tracker fluorescence, mitochondrial reactive oxygen species (ROS) measurement, ATP level quantification, and mitochondrial DNA (mtDNA) copy number analysis. Differential gene expression and associated signaling pathways were identified through bioinformatics analysis. Alterations in the transcriptional and translational levels of Lhx6 and genes associated with mitophagy were quantified using quantitative PCR (qPCR) and Western blot analysis, respectively. Mitochondrial morphology and the mitochondrial autophagosomes within cells were examined through transmission electron microscopy (TEM).ResultsAbnormal palatal development in mice, along with impaired proliferation and migration of human embryonic palatal mesenchymal (HEPM) cells, was associated with RA affecting mitochondrial function and concomitant downregulation of Lhx6. Knockdown of Lhx6 in HEPM cells resulted in altered cell proliferation, migration, and mitochondrial function. Conversely, the aberrant mitochondrial function, proliferation, and migration observed in RA-induced HEPM cells were ameliorated by overexpression of Lhx6. Subsequent research demonstrated that Lhx6 ameliorated RA-induced dysfunction in HEPM cells by modulating PINK1/Parkin-mediated mitophagy, thereby activating the MAPK signaling pathways.ConclusionLhx6 is essential for mitochondrial homeostasis via tuning PINK1/Parkin-mediated mitophagy and MAPK signaling pathways. Downregulation of Lhx6 by RA transcriptionally disturbs the mitochondrial homeostasis, which in turn leads to the proliferation and migration defect in HEPM cells, ultimately causing the cleft palate.Graphical abstract

Sustainable synthesis of silver nanoparticles from Azadirachta indica: antimicrobial, antioxidant and in silico analysis for periodontal treatment.

This study explores potential application of silver nanoparticles (AgNPs) to treat periodontal infection using Azadirachta indica leaf extract. The eco-friendly green synthesis process uses Azadirachta indica as a natural stabilizer and reducer, allowing AgNPs to be formed. Experimental AgNPs were characterized through transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), Zeta potential, ultraviolet-visible spectroscopy (UV-Vis) etc. The antimicrobial, antioxidant potential of AgNPs was tested to identify its efficacy against periodontal infections. AgNPs were found spherical, nanosized (86nm), with negative surface charge (-26.9mV). TEM study depicted clear formation of discrete nanosize particles with smooth surface texture. Results showed strong antibacterial and anti-oxidant action of experimental AgNPs, preventing biofilm growth and bacterial viability. A higher binding affinity was observed between Quercetin and the selected protein, which is implicated in bacterial growth and biofilm formation on teeth. The study suggests that Azadirachta indica derived AgNPs could be a safe, efficacious, and eco-friendly alternative in place of conventional therapies to treat periodontal infection. Future in vivo studies are however warranted.

Microstructural Characterization of Friction Stir Welds of Aluminum 6082 Produced with Bobbin Tool.

This study utilized a bobbin tool to friction stir weld aluminum 6082 workpieces under two sets of process parameters: a tool rotation speed of 280 rev/min with a weld velocity of 280 mm/min (280/280) and a tool rotation speed of 450 rev/min with a weld velocity of 450 mm/min (450/450). The weld microstructures were characterized through optical microscopy utilizing polarized light and through transmission electron microscopy (TEM) and scanning electron microscopy (SEM) coupled with chemical analysis by energy dispersive spectroscopy and electron back scatter diffraction. The microstructural studies were supplemented by hardness measurements (Vickers) performed on the same sections as the metallographic examinations. The produced weldments were free from cracks and any discontinuities. Fine, equiaxed grains that were several microns in size characterized the stir zones (SZs), and the advancing (AS) and retreating (RS) sides revealed distinct microstructural features. On the AS, the transition from the thermo-mechanically affected zone to the SZ was well defined and sharp, but on the RS, the transition appeared as a continuous, gradual change in microstructure. The lower weld energy (280/280) produced lower hardness in the stir zone than the higher energy weld (450/450), ~95 HV1 versus ~115 HV1; however, the 280/280 welds showed higher tensile strengths than the 450/450 welds, ~238 MPa as opposed to ~172 MPa. These behaviors in mechanical performance correlated with the temperature histories produced by each set of weld parameters in relation to the precipitation behavior of the alloy. The fracture characteristics of the weldments were notably different with the 450/450 sample fracturing in a quasi-brittle manner with slight plastic deformation and the 280/280 sample fracturing ductilely. A numerical simulation supported the investigation by elucidating the temperature and material flow behavior during the joining process.

Synthesis, Structure, Photoluminescence, and Optical Properties of (Co/B) Co‐Doped ZnO Nanoparticles

AbstractCo/B co‐doped ZnO nanoparticles, denoted as Zn0.95‐xBxCo0.05O, are synthesized using the sol–gel method to explore the effects of the defects on optical properties. The stoichiometry is adjusted by varying the doping levels (x = 0.00, 0.01, 0.02, 0.03, 0.04, and 0.05). X‐ray diffraction is employed to analyze the structural characteristics of all Co/B co‐doped ZnO nanoparticles, confirming the presence of a hexagonal Wurtzite structure by assessing the c/a ratios. To investigate structural defects, photoluminescence properties are measured using the Fluorescence Spectrophotometer, revealing violet, blue, green, and red emissions. With the doped of boron (B), a shift from green emission to blue emission occurs, indicating a transformation of singly charged oxygen vacancies (VO+) to VZn vacancies. Fourier Transform Infrared (FTIR) spectra (4000–400 cm−1) are acquired using the Perkin Elmer Spectrum Two FTIR‐ATR spectrophotometer. The surface morphology, crystallite size, and nanoparticle shapes are characterized through Transmission Electron Microscope (TEM) analysis. Elemental compositions are determined using Electron Dispersive Spectroscopy (EDAX). The Shimadzu 2600 UV‐Spectrophotometer is used to examine optical characteristics. The samples' energy band gaps are calculated, and the impact of dopant elements on these optical characteristics is examined. Five different models are used to compute the refractive index.

Inner Mitochondrial Membrane Peptidase 2-Like Deletion Aggravates Mitochondrial Apoptosis and Inhibits Autophagy After Hyperglycemia Stroke.

This study investigated the effects of inner mitochondrial membrane peptidase 2-like (Immp2l) deletion on mitochondrial apoptosis and mitochondrial autophagy under hyperglycemic conditions. The middle cerebral artery occlusion (MCAO) model was established in wild-type (WT) mice and Immp2l+/- mice; animals were then exposed to hyperglycemic (induced using 1% streptozotocin) and normoglycemic conditions. Tissues were collected at various time points post-reperfusion. The production of reactive oxygen species (ROS) was assessed by fluorescent measurements, and mitochondrial membrane potential was evaluated using a JC-1 assay kit. Autophagy was analyzed by measuring LC3II/LC3I protein expression and Beclin 1 expression. Mitochondrial ultrastructure was examined through transmission electron microscopy (TEM); neuronal autophagosomes were also assessed. Immp2l mutation in a hyperglycemic environment exacerbated brain injury by increasing ROS production, compromising mitochondrial membrane potential, inducing apoptotic cascades, and impairing mitochondrial autophagy. These findings highlight the critical role of Immp2l in modulating the response to hyperglycemic cerebral ischemia-reperfusion (I/R) injury. Furthermore, the deficiency of Immp2l appears to contribute to increased oxidative stress, mitochondrial dysfunction, and cell death, thereby exacerbating brain injury. These data may provide new insights into therapeutic strategies for reducing the impact of diabetes on stroke outcomes.

Clustering-Triggered Emission Mechanism of Sulfur Ester-Polyacrylamide Aqueous Solution.

Most nonconventional luminogens enjoy good water solubility and biocompatibility, showing unique application prospects in fields like biological imaging. Although clustering-triggered emission (CTE) mechanisms have been proposed to explain such emissions, it has not been thoroughly elucidated, which limits their development and application. Herein, the photoluminescence properties of polyacrylamide prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization aqueous solution are utilized to further investigate the effects of changes in concentration, in order to elucidate the emission mechanism through transmission electron microscopy (TEM), small angle X-ray scattering (SAXS) and theoretical calculation. The results showed that the size distribution, morphology, and distance between the polymer clusters formed in the water solution are successfully correlated with the cluster emission centers. The emission mechanism of nonconventional luminogens solutions is more clearly and intuitively elucidated, which has a promoting effect on the emission and application of this field. It provides a strategy a strategy to clarify the CTE mechanism of nonconventional luminogens solution more clearly.

Effect of Ni addition and bath temperature on electroless Cu microstructure in microvia preparation for HDI substrate

In this work, we investigated the microstructure evolution of electroless copper (Cu) deposition under different nickel (Ni) additions and reaction temperatures. It was found that the grain structure of electroless Cu is significantly influenced by the addition of Ni due to its inhibitory effect on Cu self-diffusion, while bath temperature had no impact on the electroless Cu grain growth. Additionally. nanovoids were observed in the electroless layer, primarily at the interface between the Cu trace and electroless layer, which is caused by the attachment of hydrogen bubbles during the electroless Cu reaction. These nanovoids do not affect the epitaxial grain growth in the microvia structure as observed through transmission electron microscopy (TEM). The nanovoids in the electroless Cu under different deposition conditions were also investigated through TEM images with the assistance of ImageJ. We found that the dimension of nanovoids initially increases with the reaction rate, as a result of the higher deposition rate introducing large hydrogen bubbles. However, as the reaction rate further increases, the size of the nanovoids stabilizes because larger hydrogen bubbles more easily escape the surface. This work may offer insights into potential approaches to enhance the quality of electroless Cu deposition for microvia preparation.

Unveiling Elegant In-Situ Properties: Structure and Vibrations of the Polymer Solution Synthesised BaFe12O19

The discovery of hexagonal ferrites has significantly contributed to various technological applications due to their unique ferromagnetic characteristics. This article employs the polymer solution technique for the first time in the synthesis of M-type hexaferrite, specifically BaFe12O19 (BaM). The polycrystalline nature of the BaM nanoparticles (NPs) is confirmed through X-ray diffraction (XRD) analysis, revealing a hexagonal structure within the P63/mmc space group. The study utilized the Scherrer method to assess the average crystallite size while utilizing the Williamson-Hall (W-H), Halder-Wagner (H-W), and Wagner-Auga (W-A) methods for a thorough analysis of XRD peak broadening, aiming to understand the relationship between crystallite size and intrinsic strain, demonstrating a high intercorrelation among the obtained results. In this work, XRD peak broadening analysis has been carried out by different models for the first time on BaM NPs. Fourier-transform infrared (FT-IR) spectroscopy was employed to designate the vibration behavior of chemical bonds, which confirms the formation of the hexagonal structure of BaM NPs. To assess the impact of excitation laser power in Raman spectroscopy, a study conducted a comprehensive analysis, comparing Raman spectra across excitation powers varied at 0.1 %, 0.5 %, 1 %, 5 %, and 10 %, maintaining a constant exposure time of 30 s throughout the experiment. Examination through Transmission Electron Microscopy (TEM) reveals a hexagonal rod-shaped morphology, with an average particle size falling within the range of 100 to 240 nanometers. The present study provides detailed insights about the structural, morphological, and compositional characteristics of BaM NPs for their utilization in high-frequency application. It shows a reflection loss (RL) of -13.68 dB at frequency of 10.3 GHz, with an absorption bandwidth of -10 dB spanning 0.42 GHz having 5 mm sample thickness.

Ligustilide alleviates oxidative stress during renal ischemia-reperfusion injury through maintaining Sirt3-dependent mitochondrial homeostasis

BackgroundRenal ischemia-reperfusion (I/R) injury is an inevitable complication during renal transplantation and is closely related to patient prognosis. Mitochondrial damage induced oxidative stress is the core link of renal I/R injury. Ligustilide (LIG), a natural compound extracted from ligusticum chuanxiong hort and angelica sinensis, has exhibited the potential to protect mitochondrial function. However, whether LIG can ameliorate renal I/R injury requires further investigation. Delving deeper into the precise targets and mechanisms of LIG's effect on renal I/R injury is crucial. PurposeThis study aimed to elucidate the specific mechanism of LIG's protective effect on renal I/R injury. MethodsIn this study, an in vivo model of renal ischemia-reperfusion (I/R) injury was developed in mice, along with an in vitro model of hypoxia-reoxygenation (H/R) using human proximal renal tubular epithelial cells (HK-2). To assess the impact of LIG on renal injury, various methods were employed, including serum creatinine (Cr) and blood urea nitrogen (BUN) testing, hematoxylin and eosin (HE) staining, and immunohistochemistry (IHC) for kidney injury molecule-1 (KIM-1). The effects of LIG on oxidative stress were examined using fluorescent probes dihydroethidium (DHE) and dichlorodihydrofluorescein diacetate (DCFH-DA), TdT-mediated dUTP Nick-End Labeling (TUNEL) staining, and flow cytometry. Additionally, the influence of LIG on mitochondrial morphology and function was evaluated through transmission electron microscopy (TEM), Mito Tracker Red CMXRos staining, adenosine triphosphate (ATP) concentration assays, and JC-1 staining. The potential mechanism involving LIG and Sirt3 was explored by manipulating Sirt3 expression through cell transfection. ResultsThe results showed that LIG could provide protective function for mitochondria to alleviate oxidative stress induced by renal I/R. Further mechanistic studies indicated that LIG maintained mitochondrial homeostasis by targeting Sirt3. ConclusionOur findings demonstrated that LIG alleviated oxidative stress during renal I/R injury through maintaining Sirt3-dependent mitochondrial homeostasis. Overall, our data raised the possibility of LIG as a novel therapy for renal I/R injury.

Synthesis, characterization and correlation studies on the Ni–Zn–Mn ferrite as a photocatalyst

Samples of Ni0.3Zn0.7−xMnxFe2O4 (x = 0, 0.15, 0.25, 0.35, 0.45, 0.55) nanoparticles (NPs) were synthesized by auto-combustion flash method. These ferrites were used as catalysts for photodegradation of methylene blue (MB) dye utilizing visible light energy. Structural analysis was carried out using the X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy, while nanoparticle dimensions were elucidated through transmission electron microscopy (TEM). The magnetic and optical behaviours were unveiled via vibrating sample magnetometer and UV–VIS spectroscopy, respectively. The XRD outcomes established the presence of a cubic spinel-type structure for the studied ferrite samples. The FTIR spectra unveiled two absorption characteristic bands of the spinel ferrite. TEM images revealed nanoscale dimensions of ferrite NPs with the range from 21.1 to 51.8 nm. The optical features exhibited an indirect band gap energy spanning from 4.25 to 4.36 eV. Magnetization behaviour displayed a sinusoidal trend corresponding to varying Mn concentrations. The ferrite NPs catalyst (10 mg) yield photodegradation efficiency ranged from 22.8 to 33.9% for 100 ml MB dye solution after 120 min of light irradiation. The effects of dye concentration and catalyst dose on the degradation efficiency were examined using the Ni0.3Zn0.35Mn0.35Fe2O4 catalyst with highest degradation (= 33.9%). On the other hand, the dependence of the degradation efficiency on the structure, morphological, magnetic and optical properties of the photocatalyst was investigated. The findings of this study underscore the potential of the prepared ferrite nanoparticles for advanced applications in environmental restoration.Graphical abstract

Quality by design approach of apocynin loaded clove oil based nanostructured lipid carrier as a prophylactic regimen in hemorrhagic cystitis in vitro and in vivo comprehensive study

Apocynin (APO) is a naturally occurring acetophenone with eminent anti-inflammatory and anti-oxidant peculiarities. It suffers from poor bioavailability due to low aqueous solubility. Herein, APO was loaded in a Clove oil (CO) based Nanostructured lipid carrier (NSLC) system using a simple method (ultrasonic emulsification) guided by a quality-by-design approach (23 full factorial design) to optimize the formulated NSLCs. The prepared NSLCs were evaluated regarding particle size (PS), polydispersity index (PDI), zeta potential (ZP), and entrapment efficiency (EE%). The optimal formula (F2) was extensively investigated through transmission electron microscope (TEM), Fourier transform infrared (FT-IR) spectroscopy, Differential scanning calorimetry (DSC), X-ray diffractometry (XRD), in vitro release, and stability studies. Cytotoxicity against human urinary bladder carcinoma (T24) cell line and in vivo activity studies in rats with induced cystitis were also assessed. The results disclosed that the optimal formula (F2) had PS of 214.8 ± 5.8 nm with EE% of 79.3 ± 0.9%. F2 also exhibited a strong cytotoxic effect toward the T24 cancer cells expressed by IC50 value of 5.8 ± 1.3 µg/mL. Pretreatment with the optimal formula (orally) hinted uroprotective effect against cyclophosphamide (CP)-induced hemorrhagic cystitis (HC) in rat models, emphasized by histopathological, immunohistochemical, and biochemical investigations. In consideration of the simple fabrication process, APO-loaded CO-based NSLCs can hold prospective potential in the prophylaxis of oncologic and urologic diseases.

Antioxidant, Antitumoral, Antimicrobial, and Prebiotic Activity of Magnetite Nanoparticles Loaded with Bee Pollen/Bee Bread Extracts and 5-Fluorouracil.

The gut microbiota dysbiosis that often occurs in cancer therapy requires more efficient treatment options to be developed. In this concern, the present research approach is to develop drug delivery systems based on magnetite nanoparticles (MNPs) as nanocarriers for bioactive compounds. First, MNPs were synthesized through the spraying-assisted coprecipitation method, followed by loading bee pollen or bee bread extracts and an antitumoral drug (5-fluorouracil/5-FU). The loaded-MNPs were morphologically and structurally characterized through transmission electron microscopy (TEM), selected area electron diffraction (SAED), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Dynamic Light Scattering (DLS), and thermogravimetric analysis. UV-Vis spectroscopy was applied to establish the release profiles and antioxidant activity. Furthermore, the antibacterial and antitumoral activity of loaded-MNPs was assessed. The results demonstrate that MNPs with antioxidant, antibacterial, antiproliferative, and prebiotic properties are obtained. Moreover, the data highlight the improvement of 5-FU antibacterial activity by loading on the MNPs' surface and the synergistic effects between the anticancer drug and phenolic compounds (PCs). In addition, the prolonged release behavior of PCs for many hours (70-75 h) after the release of 5-FU from the developed nanocarriers is an advantage, at least from the point of view of the antioxidant activity of PCs. Considering the enhancement of L. rhamnosus MF9 growth and antitumoral activity, this study developed promising drug delivery alternatives for colorectal cancer therapy.

Harnessing extracellular vesicles-mediated signaling for enhanced bone regeneration: novel insights into scaffold design

The increasing prevalence of bone replacements and complications associated with bone replacement procedures underscores the need for innovative tissue restoration approaches. Existing synthetic grafts cannot fully replicate bone vascularization and mechanical characteristics. This study introduces a novel strategy utilizing pectin, chitosan, and polyvinyl alcohol to create interpenetrating polymeric network (IPN) scaffolds incorporated with extracellular vesicles (EVs) isolated from human mesenchymal stem cells (hMSCs). We assess the osteointegration and osteoconduction abilities of these models in vitro using hMSCs and MG-63 osteosarcoma cells. Additionally, we confirm exosome properties through Transmission Electron Microscopy (TEM), immunoblotting, and Dynamic Light Scattering (DLS). In vivo, chick allantoic membrane assay investigates vascularization characteristics. The study did not include in vivo animal experiments. Our results demonstrate that the IPN scaffold is highly porous and interconnected, potentially suitable for bone implants. EVs, approximately 100 nm in size, enhance cell survival, proliferation, alkaline phosphatase activity, and the expression of osteogenic genes. EVs-mediated IPN scaffolds demonstrate promise as precise drug carriers, enabling customized treatments for bone-related conditions and regeneration efforts. Therefore, the EVs-mediated IPN scaffolds demonstrate promise as precise carriers for the transport of drugs, allowing for customized treatments for conditions connected to bone and efforts in regeneration.

Green synthesized extracts/Au complex of Phyllospongia lamellosa: Unrevealing the anti-cancer and anti-bacterial potentialities, supported by metabolomics and molecular modeling

The anti-cancer and anti-bacterial potential of the Red Sea sponge Phyllospongia lamellosa in its bulk (crude extracts) and gold nanostructure (loaded on gold nanaoparticles) were investigated. Metabolomics analysis was conducted, and subsequently, molecular modeling studies were conducted to explore and anticipate the P. lamellosa secondary metabolites and their potential target for their various bioactivities. The chloroformic extract (CE) and ethyl acetate extract (EE) of the P. lamellosa predicted to include bioactive lipophilic and moderately polar metabolites, respectively, were used to synthesize gold nanoparticles (AuNPs). The prepared AuNPs were characterized through transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and UV–vis spectrophotometric analyses. The cytotoxic activities were tested against MCF-7, MDB-231, and MCF-10A. Moreover, the anti-bacterial, antifungal, and anti-biofilm activity were assessed. Definite classes of metabolites were identified in CE (terpenoids) and EE (brominated phenyl ethers and sulfated fatty amides). Molecular modeling involving docking and molecular dynamics identified Protein-tyrosine phosphatase 1B (PTP1B) as a potential target for the anti-cancer activities of terpenoids. Moreover, CE exhibited the most powerful activity against breast cancer cell lines, matching our molecular modeling study. On the other hand, only EE was demonstrated to possess powerful anti-bacterial and anti-biofilm activity against Escherichia coli. In conclusion, depending on their bioactive metabolites, P. lamellosa-derived extracts, after being loaded on AuNPs, could be considered anti-cancer, anti-bacterial, and anti-biofilm bioactive products. Future work should be completed to produce drug leads.

Comparative analysis of microstructure, electrical and optical performance in sidewall etching process for GaN-based green micro-LED

Micro-LEDs show the size-dependent external quantum efficiency (EQE) reduction problem, mainly owing to increased non-radiative recombination loss at the sidewall for smaller chip size. In this work, the evolution of microstructure, surface potential and optical performance of the green micro-LED sidewall was investigated comparatively after inductively coupled plasma (ICP) and tetramethylammonium hydroxide (TMAH) etching through transmission electron microscopy (TEM), Kelvin probe force microscope (KPFM), cathodoluminescence (CL) and time-resolved photoluminescence (TRPL). As confirmed by TEM and geometric phase analysis (GPA), ICP etching causes sidewalls to form atomically rough semi-polar surfaces and increases 25% compressive strain at the sidewall compared to the inside. TMAH solution introduces new sidewall defects due to excessive etching of three atomic layers of InGaN. Holes accumulate at the surface because of build-in electric field as showed by KPFM. The sidewall defects lead to a decrease in carrier lifetime resulting in uneven luminescence of micro-LED mesa. TMAH treatment removes the damaged layer and reduces the non-radiative recombination rate. ICP causes damage to the nanoscale structure, however the influence of sidewall defects on the carrier behavior is in the micron range due to unavoidable surface dangling bonds and surface lattice relaxation. A non-radiative recombination mechanism is proposed based on strain relaxation.

Biosynthesis of gold nanoparticles by fungi and its potential in SERS.

Surface enhanced Raman spectroscopy (SERS) by using gold nanoparticles (AuNPs) has gained relevance for the identification of biomolecules and some cancer cells. Searching for greener NPs synthesis alternatives, we evaluated the SERS properties of AuNPs produced by using different filamentous fungi. The AuNPs were synthesized utilizing the supernatant of Botrytis cinerea, Trichoderma atroviride, Trichoderma asperellum, Alternaria sp. and Ganoderma sessile. The AuNPs were characterized by ultraviolet-visible spectroscopy (UV-Vis) to identify its characteristic surface plasmon resonance, which was located at 545nm (B. cinerea), 550nm (T. atroviride), 540nm (T. asperellum), 530nm (Alternaria sp.), and 525nm (G. sessile). Morphology, size and crystal structure were characterized through transmission electron microscopy (TEM); colloidal stability was assessed by Z-potential measurements. We found that, under specific incubation conditions, it was possible to obtain AuNPs with spherical and quasi-spherical shapes, which mean size range depends on the fungal species supernatant with 92.9nm (B. cinerea), 24.7nm (T. atroviride), 16.4nm (T. asperellum), 9.5nm (Alternaria sp.), and 13.6nm (G. sessile). This, as it can be expected, has an effect on Raman amplification. A micro-Raman spectroscopy system operated at a wavelength of 532nm was used for the evaluation of the SERS features of the AuNPs. We chose methylene blue as our target molecule since it has been widely used for such a purpose in the literature. Our results show that AuNPs synthesized with the supernatant of T. atroviride, T. asperellum and Alternaria sp. produce the stronger SERS effect, with enhancement factor (EF) of 20.9, 28.8 and 35.46, respectively. These results are promising and could serve as the base line for the development of biosensors through a facile, simple, and low-cost green alternative.

Temperature-induced variations in the structural, morphological and optical features of cobalt oxide nanoparticles synthesized via hydrothermal method

Cobalt oxide is a promising material that attracts the researchers to find its application in various fields like catalysts, dielectric applications, gas sensors and electronics devices, etc. In this work, we investigated the effect of temperature in the structural, elemental, morphological and optical properties of Co3O4 nanoparticles synthesized by hydrothermal method. The as-prepared and annealed samples were observed for their structural and optical properties. The structural analysis and micro-strain effects of Co3O4 nanoparticles with cubic spinel structure were carried out through X-ray diffraction (XRD) studies. The crystallite size of as-prepared and annealed samples were around 27 nm and 29 nm, respectively. Raman spectrum showed the lattice vibrations of both oxidation states of cobalt oxide nanoparticles. Elemental analysis were observed through X-ray photoelectron spectroscopy (XPS). The morphology and chemical composition of the samples were determined from the field emission scanning electron microscope (FESEM) image and energy dispersive X-ray spectroscopy (EDAX). Moreover, the internal structure of both samples were compared through transmission electron microscopic (TEM) studies. The optical studies were done using the absorption spectrum and photoluminescence spectroscopy. Two direct band gaps (1.8 and 3.2 eV) were observed in the as-prepared, which got red-shifted on annealing (1.7 and 2.5 eV) due to size effects. The charge transfer process in two oxidation states of cobalt oxide could be identified from these bandgaps. Emission peaks in the photoluminescence spectrum of samples are due to the recombination of free-excitons and point defects in the crystal lattice.

Engineering a Hierarchy of Disorder: A New Route to Synthesize High-Performance 3D Nanoporous All-Carbon Materials*.

A new nanoporous amorphous carbon (NAC) structure that achieves both ultrahigh strength and high electrical conductivity, which are usually incompatible in porous materials is reported. By using modified spark plasma sintering, three amorphous carbon phases with different atomic bonding configurations are created. The composite consisted of an amorphous sp2-carbon matrix mixed with amorphous sp3-carbon and amorphous graphitic motif. NAC structure has an isotropic electrical conductivity of up to 12000Sm-1, Young's modulus of up to ≈5GPa, and Vickers hardness of over 900MPa. These properties are superior to those of existing conductive nanoporous materials. Direct investigation of the multiscale structure of this material through transmission electron microscopy, electron energy loss spectroscopy, and machine learning-based electron tomography revealed that the origin of the remarkable material properties is the well-organized sp2/sp3 amorphous carbon phases with a core-shell-like architecture, where the sp3-rich carbon forms a resilient core surrounded by a conductive sp2-rich layer. This research not only introduces novel materials with exceptional properties but also opens new opportunities for exploring amorphous structures and designing high-performance materials.