Transmission Electron Microscopy Studies Research Articles

DESIGN AND OPTIMIZATION OF NANO ENCAPSULATED BIO COMPOUNDS OF ASPARAGUS RACEMOSUS: BOX BEHNKEN APPROACH

Objective: The current study’s objective is to develop and optimize nanoencapsulated bio compounds of Asparagus racemosus (BCAR) utilizing the ionic gelation process to target the kidney for antiurolithiatic activity. Methods: Nanoencapsulated BCAR was prepared employing the ionic gelation method. Box Behnken Design (BBD) 3-factor, 3-level is used to examine the effects of formulation parameters and to enhance the desired responses. Characterization studies include Fourier transform infrared (FTIR), X-ray diffraction (XRD), particle size, zeta potential, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) performed to study the quality of optimized nanoparticles. Results: Mathematical equations and response surface plots were used to relate the dependent and independent variables. Diagnostic charts were used to show the varied factor-level permutations. The percentages of entrapment efficiency (% EE) and drug release (% DR) used in evaluation studies of optimized bio compounds of BCAR nanoparticles (OBCARNPs) were determined to be 80.67% and 77.4%, respectively. The Fourier transform infrared (FTIR) results showed that chitosan, sodium tripolyphosphate (NaTPP), and BCAR were compatible. Due to chitosan and NaTPP gelation in the case of OBCBANPs, X-ray diffraction (XRD) analyses have acknowledged the crystallinity. The particle size and zeta potential of the optimized formulation, found to be 48.8 nm and 14.1 mV, respectively, indicate the nanoparticles are in the nanorange and possess extreme stability by preventing particle convergence. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) studies reveal that the optimized formulation nanoparticles are spherical in shape, homogeneous, and have little aggregation. The accelerated stability studies showed that the optimized formulation was stable at different temperatures and relative humidity. Conclusion: The stable, optimized formulation was prepared, evaluated, and characterized. BBD is employed to optimize the formulation by minimizing the number of experimental runs and enhancing the desired responses. The optimized formulation further needs to investigate the in vivo studies for antiurolithiatic activity by targeting the kidney.

Effect of prestrain on tensile behavior of HS800 steel sheet

With the development of advanced high strength steels like HS800 and HS1000, it is imperative to develop an understanding of their tensile properties. The effect of 0%, 5%, 7.5%, and 10% prestrain on the tensile behaviour of HS800 steel sheet was investigated in the current research. The optical micrograph of as received HS800 steels reveals the presence of ferrite grains with polygonal morphology without the presence of pearlite or cementite. Moreover, in higher pre-straining conditions, both polygonal and acicular ferrite phases are observed to coexist with the second phase (martensite/austenite). Tensile tests were performed on base HS800 steel sheets in three different directions (rolling, transverse, and diagonal), and it was found that the strength and ductility in the transverse direction were greater than the rolling and diagonal direction. Tensile strength had a linear relationship with the prestrain condition, whereas ductility had an inverse relationship. XRD analysis was used for phase identification and determination of dislocation density. A scanning electron microscope (SEM) was used to observe the ductile fracture behaviour in tensile specimens. The strain hardening exponent of HS800 steel was determined by comparing tensile data to Hollomon and Ludwik's mathematical equations. To understand the dislocation structure evolution of as received and various prestraining conditions samples, a transmission electron microscope (TEM) study was performed. The prestraining study of the HS800 steel gives a new horizon to high strength materials that can be utilized to design the current and future automobile industries requirements.

Self‐templated magnesiothermic reduction of ORMOSIL particles to monodisperse hollow spherical SiC composite particles

AbstractHollow silicon carbide (SiC) particles have attracted attention due to their well‐defined morphology, low density, and large surface area that can be leveraged for a wide variety of applications. Here, we report the self‐templated synthesis of monodisperse hollow spherical SiC composite particles with controllable shell thicknesses using magnesiothermic reduction of organically modified silica (ORMOSIL) particles. Monodisperse ORMOSIL particles containing three organic groups of methyl, vinyl, and mercaptopropyl were produced by a simple one‐pot sol–gel process and then converted to hollow spherical SiC composite particles via a magnesiothermic reduction at 700°C under an inert atmosphere. The spherical morphologies of the original ORMOSIL particles were well maintained through this self‐templated conversion process, but the sizes of the hollow SiC particles were slightly reduced by the thermal treatment. Field emission transmission electron microscopy studies revealed that the shell of hollow particles mainly consists of primary β‐SiC particles with nanometer‐scale sizes. The physical and chemical properties of the hollow SiC composite particles were investigated by scanning electron microscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy, Brunauer–Emmett–Teller, X‐ray diffraction, Fourier transform infrared spectroscopy, Raman, and solid‐state nuclear magnetic resonance analyses. The shell thickness of hollow spherical SiC composite particles can be controlled by simply changing the duration of the thermal conversion process. This study not only provides a simple and easy approach for the preparation of hollow spherical SiC particles but also opens the possibility of large‐scale manufacturing of such particles for commercial applications.

Vertical transmission and prevalence of white spot syndrome virus (WSSV) in the wild spawning population of the Indian white shrimp, Penaeus indicus

White spot disease, caused by white spot syndrome virus (WSSV), has historically been the most devastating disease in shrimp aquaculture industry across the world. The mode of virus transmission is the most crucial stage in the dynamics and management of virus infection. This study explored the mechanism of vertical transmission of WSSV in Indian white shrimp, Penaeus indicus, potential native species for domestication and genetic improvement, using quantitative real time PCR (q RT PCR), light and electron microscopy, and in situ hybridization. Wild brooders of P. indicus (n = 2576) were sampled along the South east coast of India, during 2016 to 2021. Of these ∼ 58 % of the brooders were positive for WSSV, and almost 50 % of infected wild brooders were at the various stages of reproductive maturation. WSSV-PCR positive brooders (n = 200) were analysed for vertical WSSV transmission. The q RT PCR studies of reproductive tissues revealed that 61 % (n = 13) of spermatophore, 54 % (n = 28) of immature ovaries and 48 % (n = 27) of ripe ovaries were infected with WSSV. The lowest level of infection was recorded in females with ripe ovaries (6.84 × 101 ± 9.79 × 100 ng genomic DNA) followed by fertilized eggs (1.59 × 102 ± 3.69 × 101 ng genomic DNA), and larvae (nauplius and zoea). The histology of gravid females with high WSSV copies showed pyknotic and karyorrhectic germinal vesicle with degenerated cortical rods. Conversely, the gravid females with low WSSV copies showed fully developed ovary without characteristic signs of WSSV infection. Transmission electron microscopic studies clearly established the presence of WSSV particles in both ovaries and spermatophores. When subjected to in situ hybridization, WSSV-specific signals were observed in connective tissues of spermatophore, although gravid ovary and fertilized eggs were failed to produce WSSV specific signals. The present study provides the first molecular and histological evidence for trans-ovarian vertical transmission of WSSV. Development of disease-free base population being the cornerstone and first step in establishing the breeding program, the present findings could be a basis for development of such programs.

Enhanced Catalytic Performance of Carbon Nitride-Functionalized Titanium Dioxide through Efficient Oxygen Vacancy Defect Engineering for Electrochemical Recognition of Epinephrine

Oxygen defect engineering is a reliable and efficient approach to modulate the electronic structure of metal oxides for the improvement of catalytic efficiency. In this work, carbon nitride supported titanium dioxide nanoparticle, with the space group of I41/amd, was prepared using a high temperature synthesis route. Transmission electron microscope study revealed that titanium dioxide particle were dispersed uniformly on the carbon nitride network. The X-ray photoelectron spectroscopy analysis predicted the formation of oxygen defects in the matrix of titanium oxide, and it also indicated the presence of titanium ions with mixed valence states. The synthesized hybrid system was evaluated as an electrocatalyst for the electrochemical detection of epinephrine using cyclic voltammetric and square wave voltammetric techniques. A custom-made device was also fabricated using synthesized hybrid material for the purpose of evaluating the electrochemical sensing of epinephrine in a pharmaceutical sample.

Study of morphology and orchid mycorrhizal associations in Malaxis rheedei

The mycorrhizal association in orchids is a striking example of mutualism, where the orchid and the associated mycorrhizal fungi exchange essential nutrients and support each other’s growth and reproduction. The present study focused on a selected terrestrial orchid which is noteworthy for its medicinal value. We aimed to investigate the specific mycorrhizal associations to understand how these interactions influence the morphology of their roots. The morphological characteristics of roots were studied using light microscopy. Transmission electron microscopy studies were conducted to analyze and measure fungal hyphae and peloton sizes as well as to know about fungal colonization distribution. Phylogenetic analysis was conducted to identify the mycorrhizal fungi. Colonization was seen in the 91% root cortex proving high mycorrhizal association. Hyphae appeared in the form of peloton patches at the cortex, occupying up to 62% of the cortical space. The root length with an intact peloton was noted 30% more than the degraded peloton. A single fungus, Tulasnella calospora was isolated from the roots. It was identified using phylogenetic analysis of ITS sequences. Identification of this orchid-mycorrhizal association has the potential to address ecological challenges, contribute to its conservation, and unlock the phytochemical potential of plant-fungus interactions for drug development.

Hierarchical structure promoted lithiation/delithiation behavior of a double-carbon microsphere supported nano-Co3O4 anode.

Due to limited mass loading, high-capacity electrode materials such as transition metal oxides (TMOs) are essential for microscale Li-ion batteries (LIBs) integrated in nano-/micro-electromechanical systems (N/MEMS). Unfortunately, their electrochemical performances are largely plagued by severe mechanical degradation and slow electron transport. Therefore, it is crucial to develop strategies that can improve the structural stability and electronic conductivity of TMO electrodes. In this work, double-carbon (carbon nanotubes and ketjen black) microsphere (DCMS) supported Co3O4 electrodes are fabricated simply through a spray drying and solvothermal method, which are designed to have a mesoporous three-dimensional (3D) hierarchical heterostructure containing well-dispersed Co3O4 nanoparticles within the DCMS framework. An in situ transmission electron microscopy (TEM) study reveals that the DCMS framework can not only provide facile strain accommodation, but also good electronic conductivity, leading to a much improved Li-storage performance compared to other Co3O4-based anodes. The hierarchical electrode exhibits maximum charge capacities of 1205.2 and 678.1 mA h g-1 at current densities of 0.1 and 2 A g-1, respectively, as well as a capacity retention of 92.2% at 0.3 A g-1 after 100 cycles. This study provides a low-cost, simple and general method for developing advanced high-capacity electrodes.

Purification and Cryo-Electron Microscopy Analysis of Bacterial Appendages.

A number of extracellular helical protein polymers are crucial for supporting bacterial motility. The bacterial flagellum is a polymeric appendage used to support cellular motility. Historically, structural studies of flagellar and other filaments were limited to those present as or locked into straightened states. Here, we present a robust workflow that produces biologically relevant high-resolution cryo-electron microscopy (cryo-EM) structures of bacterial flagellar filaments. We highlight how a simple purification method, centered around several centrifugation steps, exploits the process of filament ejection in Caulobacter crescentus and results in isolated filaments amenable to transmission electron microscopy (TEM) studies. The quality of the sample is validated by SDS-PAGE and negative stain TEM analysis before a sample is vitrified for cryogenic electron microscopy (cryo-EM) data collection. We provide a detailed protocol for reconstructing either straight or curved flagellar filaments by cryo-EM helical reconstruction methods, followed by an overview of model building and validation. In our hands, this workflow resulted in several flagellar structures below 3 Å resolution, with one data set reaching a global resolution of 2.1 Å. The application of this workflow supports structure-function studies to better understand the molecular interactions that regulate filament architecture in biologically relevant states. Future work will not only examine interactions that regulate bacterial flagellar and other filament organization but also provide a foundation for developing new helical biopolymers for biotech applications. Key features • Rapid high-quality purification of bacterial flagella via simple bacterial culturing, centrifugation, and resuspension methods. • High-throughput cryo-EM data collection of filamentous objects. • Use of cryoSPARC implementations of helical reconstruction algorithms to generate high-resolution 3D structures of bacterial flagella or other helical polymers.

Tailoring the pore structure of iron oxide core@stellate mesoporous silica shell nanocomposites: effects on MRI and magnetic hyperthermia properties and applicability to anti-cancer therapies.

Core-shell nanocomposites made of iron oxide core (IO NPs) coated with mesoporous silica (MS) shells are promising theranostic agents. While the core is being used as an efficient heating nanoagent under alternating magnetic field (AMF) and near infra-red (NIR) light and as a suitable contrast agent for magnetic resonance imaging (MRI), the MS shell is particularly relevant to ensure colloidal stability in a biological buffer and to transport a variety of therapeutics. However, a major challenge with such inorganic nanostructures is the design of adjustable silica structures, especially with tunable large pores which would be useful, for instance, for the delivery of large therapeutic biomolecule loading and further sustained release. Furthermore, the effect of tailoring a porous silica structure on the magneto- or photothermal dissipation still remains poorly investigated. In this work, we undertake an in-depth investigation of the growth of stellate mesoporous silica (STMS) shells around IO NPs cores and of their micro/mesoporous features respectively through time-lapse and in situ liquid phase transmission electron microscopy (LPTEM) and detailed nitrogen isotherm adsorption studies. We found here that the STMS shell features (thickness, pore size, surface area) can be finely tuned by simply controlling the sol-gel reaction time, affording a novel range of IO@STMS core@shell NPs. Finally, regarding the responses under alternating magnetic fields and NIR light which are evaluated as a function of the silica structure, IO@STMS NPs having a tunable silica shell structure are shown to be efficient as T2-weighted MRI agents and as heating agents for magneto- and photoinduced hyperthermia. Furthermore, such IO@STMS are found to display anti-cancer effects in pancreatic cancer cells under magnetic fields (both alternating and rotating).

Anomalous two-step repair mechanism of Al–Cu alloy regulated by the surroundings during E-beam irradiation

Understanding the repair mechanisms of defects is essential for gaining insight into improving the quality and enhancing the performance of materials. While new structures and elemental segregation always exist around defects, the influence of the surroundings on the repair mechanism has rarely been investigated on the atomic scale. Here, by tracking the morphological and microstructural evolution of Al2Cu nanopores with and without Cu-rich phases in the vicinity under electron beam irradiation, our in-situ transmission electron microscopy (TEM) study revealed a surrounding-dependent repair behavior. In contrast to the Al2Cu nanopores without Cu-rich neighborhoods, which display an isotropically shrinking from all directions, the Al2Cu nanopores with Al4Cu9 nearby exhibit an anomalous two-step repair mechanism. First, new Al4Cu9 structures nucleated from the Cu-rich region and evolved to fill the nanopores. Second, Al4Cu9 reacted with Al atoms and gradually transformed into Al2Cu. High-resolution TEM (HRTEM) images and strain maps demonstrate that the repair is imperfect as the eventual repaired region contains both Al4Cu9 and Al2Cu. This is caused by the simultaneous sputtering and depositing effects of electron beams (E-Beam). Our findings provide critical insights into the modulatory function of surroundings on the nanopore repair mechanism.

Microneedle-assisted transdermal delivery of carvedilol nanosuspension for the treatment of hypertension

Carvedilol nanosuspension loaded microneedles patch was formulated and characterized by particle size, zeta potential, solubility, Transmission Electron Microscopy, X-Ray Diffraction, in-vitro release and in-vivo pharmacokinetic studies

Green synthetic photo-irradiated chitin-silver nanoparticles for antimicrobial applications

The primary purpose of this study was to synthesize silver nanoparticles (AgNPs) utilizing chitin extracted from shrimp shell waste by simple photo-irradiation in a single-pot biosynthesis without adding any toxic chemical substances. Glucose molecules in the chitin extract act as the reducing agent, while amino acids in chitin behave like proteins and are responsible for the production of AgNPs by acting as the particle-stabilizing agent. The synthesized chitin-AgNPs were thoroughly investigated using transmission electron microscopy (TEM), Fourier-transform infrared analysis, and ultraviolet-visible absorption spectroscopy. UV-visible spectroscopy revealed a surface plasmon resonance peak at 470 nm, confirming the formation of chitin-AgNPs. FTIR data confirmed the association between chitin and AgNPs. TEM studies showed that the synthesized chitin-AgNPs have a spherical shape with particle sizes ranging from 10 to 30 nm. The prepared chitin-AgNPs exhibited intense antibacterial activity against the Gram-positive Bacillus subtilis, Staphylococcus aureus, Gram-negative Pseudomonas aeruginosa, and Escherichia coli, as well as antifungal efficacy against Aspergillus niger. Reactive oxygen species and live and dead cell assays were performed to examine the chitin- AgNPs and the results were further found to be interesting and positive. The assays revealed that the prepared chitin- AgNPs exhibited significant antimicrobial potential against B. subtilis and A. niger, with a zone of inhibition measuring approximately 6.2 mm and 30 mm, respectively. The effects of the chitin-AgNPs were compared to those of commercial agents, such as ciprofloxacin (6.0 mm) and fluconazole (25 mm). Consequently, the chitin-AgNPs developed through a greener approach show promising potential as sustainable materials for antibacterial and antifungal activities.

Ultrastructural changes in the rat retina in the presence of long-term opioid exposure

Purpose: To determine the features of the untrastructural reorganization in the rat retina by the end of week 4 and week 6 of experimental opioid exposure. Material and Methods: Forty-eight adult male albino rats (weight, 200-250 g; age, 4.5 months) were used in this study. They received nalbuphine hydrochloride intramuscularly daily for 42 days. Particularly, the drug was administered daily at a dose of 0.212 mg/kg for weeks 1 and 2, 0.225 mg/kg for weeks 3 and 4, and 0.252 mg/kg for weeks 5 and 6. In this way, we experimentally created the conditions of chronic opioid exposure. Animals were divided into three groups. Group 1 (19 animals) received nalbuphine for 28 days, and group 2 (19 animals), for 42 days. Group 3 (control group) comprised 10 animals. Of these, 5 animals were treated with normal saline at a dose of 0.22 mg/kg intramuscularly daily for 28 days, and the rest were treated in a similar manner for 42 days. Transmission electron microscopy studies of the rat retina were conducted in a routine manner. Results: By the end of week 4 of experimental opioid exposure, there was an increase in the number of retinal microvessels with signs of hyperemia and degenerative changes in retinal pigment epithelium (RPE) cells, increase in the destruction of membranous discs of photoreceptor outer segments, necrobiotic changes in the nuclei of individual photoreceptors, axonal degeneration in the outer and inner plexiform layers, degenerative changes in retinal horizontal neurons, and the appearance of necrotic structural changes in the cytoplasm of bipolar and amacrine cells. By the end of week 6, there was a further increase in hyperemia of retinal vessels and degenerative and necrotic changes in individual RPE cells and photoreceptor outer segments. In addition, we observed destruction and shortening of mitochondrial cristae of photoreceptor inner segments, necrotic nuclear changes in individual photoreceptors, degeneration of axons of the outer and inner plexiform layers, degenerative and necrotic changes in bipolar and amacrine cells, hypertrophic Müller cell processes, degeneration of ganglion cells, and vascular hyperemia and moderate perivascular edema in the outer and inner plexiform layers. Conclusion: Therefore, in the current rat study, after a 4-week exposure to daily nalbuphine injections at a dose ranging 0.212 to 0.253 mg/kg, there was ultrastuctural evidence of destructive processes in the RPE and photoreceptor outer segments, axonal degeneration in the outer and inner plexiform layers, degenerative and necrotic changes in bipolar and amacrine cells, hypertrophic Müller cell processes, ganglion cell degeneration and hyperemia due to an impaired retinal microcirculatory ultrastructure. At week 6 of the experiment, there was evidence of increased destructive and degenerative processes in structural components of the retina.

Ultrastructural study: in vitro and in vivo differentiation of mice spermatogonial stem cells.

Mouse testicular tissue is composed of seminiferous tubules and interstitial tissue. Mammalian spermatogenesis is divided into three stages: spermatocytogenesis (mitotic divisions) in which spermatogonial stem cells (SSCs) turn into spermatocytes, followed by two consecutive meiotic divisions in which spermatocytes form spermatids. Spermatids differentiate into spermatozoa during spermiogenesis. Various factors affect the process of spermatogenesis and the organization of cells in the testis. Any disorder in different stages of spermatogenesis will have negative effects on male fertility. The aim of the current study was to compare the in vitro and in vivo spermatogenesis processes before and after transplantation to azoospermic mice using ultrastructural techniques. In this study, mice were irradiated with single doses of 14 Gy 60Co radiation. SSCs isolated from neonatal mice were cultured in vitro for 1 week and were injected into the seminiferous tubule recipient's mice. Testicular cells of neonatal mice were cultured in the four groups on extracellular matrix-based 3D printing scaffolds. The transplanted testes (8 weeks after transplantation) and cultured testicular cells in vitro (after 3 weeks) were then processed for transmission electron microscopy studies. Our study's findings revealed that the morphology and ultrastructure of testicular cells after transplantation and in vitro culture are similar to those of in vivo spermatogenesis, indicating that spermatogenic cell nature is unaltered in vitro.

Investigation of antimicrobial and anti-cancer activity of thermally sensitive SnO2 nanostructures with green-synthesized cauliflower morphology at ambient weather conditions

A tin oxide (SnO2) nanostructure was prepared using Matricaria recutita leaf extract to investigate its anticancer activity against SK-MEL-28 cells. The tetragonal crystal structure of tin oxide nanoparticles with an average crystal size of 27 nm was confirmed by X-ray diffraction (XRD) analysis. The tetragonal crystal structure of the tin oxide nanoparticles, with an average crystallite size of 27 nm, was confirmed by XRD an absorbance peak at 365 nm was identified by UV–visible spectroscopy analysis as belonging to the bio-mediated synthesis of SnO2 nanoparticles. The SnO2 NPs are capped and stabilized with diverse functional groups derived from bioactive molecules, including aldehydes, benzene rings, amines, alcohols, and carbonyl stretch protein molecules. Fourier transform infrared spectroscopy (FTIR) analysis validated the presence of these capping and stabilizing chemical bonds. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies revealed the cauliflower-shaped morphology of the SnO2 nanoparticles with an average particle size of 28 nm. The antimicrobial activity of both prepared and encapsulated samples confirmed their biological activities. Furthermore, both prepared and encapsulated tin oxide samples exhibited excellent anticancer activity against SK-MEL-28 human cancer cells. The present study introduces a reliable and uncomplicated approach to produce SnO2 nanoparticles and demonstrates their effectiveness in various applications, including cancer therapy, drug administration, and disinfectant.

Advancing Liquid-EM Techniques and Workflows for Operando Studies of Energy Materials

The need for clean, renewable energy has driven the expansion of research focused on new materials for electrocatalysts, fuel cells, and batteries. These materials need to be plentiful, inexpensive, and have high energy capacity operating lifetimes to power a growing consumer market that is seeking alternatives to fossil-based fuel sources.[1] However, energy materials often operate at the nanoscale, which involves structural or morphological changes that can only be observed using transmission electron microscopy (TEM). To get more insight in the nanoscale changes, operando TEM can be used to observe a catalyst or battery material under its native operating conditions.Operando TEM techniques enable dynamic, real-time imaging of a material’s nanoscale processes as they occur within their functional environment.[2] This enables researchers to simultaneously follow structural and morphological changes and correlate those to the material’s electrochemical behavior. Operando studies using liquid electrolytes can utilize liquid-EM. In this case, a sample is encapsulated in a liquid environment between electron transparent membranes, which enables researchers to study reactions as they occur in an electrolyte environment.[1] This technique has enabled researchers to better understand the mechanistic pathways that can result in electrocatalyst deactivation [3,4] battery capacity fading [5-7]and identify targets within these materials to improve their performance.[8,9,10] However, as operando TEM combines multiple challenging topics, e.g. battery studies, electrolyte degradation, radiolysis and dose management, it has so far been a laborious undertaking for any one researcher alone.Successful operando liquid-EM experiments are challenging due to many factors, beginning with experiment design and workflow, and culminating complex analysis of multiple streams of large, often cumbersome, datasets. Here, we have set out to address and develop hardware and software tools which mitigate some of the most common challenges associated with operando liquid-EM electrochemical studies. Using a machine vision software platform called AXON, a holistic, workflow-driven approach to address key challenges and pain points associated with in-situ and operando TEM studies has been developed. New hardware and MEMs-based features integrated into the liquid-EM solution, Poseidon Select (Figure 1A), include the ability to perform electrochemical studies beyond room temperature, and improved stabilization of electrochemical signals for correlation with bulk studies. Moreover, adding a Luggin-Haber metal probe for electrical measurements allows for the use of any reference electrode compared to the limitation of a pseudo-reference electrode, e.g. platinum (Figure 1B).[11] On top of this, AXON uses learning algorithms for improved stabilization and tracking of dynamic samples, accurate dose quantification and management, consolidation of experimental parameters and metadata, and an intuitive, free-to-use, visual data analysis tool, AXON Studio.In this talk, examples of liquid-EM microscopy work for energy materials will be shown, as shown in Figure 1C-D. In this figure, copper nanograins were used to convert CO2 to multicarbon products while observing the morphological changes to the nanograins over time and simultaneously observing the electrochemical changes in the sample. Moreover, explanations and examples will be shown on how machine-vision software solutions can improve the workflow of electrochemical in-situ experiments. These workflow methods elevate the operation of in-situ experiments so that any one researcher can now operate microscope and in-situ cell simultaneously.[1] Yang, Y. et al. (2021) ACS Catalysis 11, 1136–1178.[2] Chenna, S. et al. (2012) ACS Catalysis, 2, 2395–2402.[3] Shi, F. et al. (2020) Chem, 6, 2257–2271.[4] Impagnatiello, A. et al. (2020) ACS Applied Energy Materials, 3, 2360–2371.[5] Bhatia, A. et al. (2021) Small Methods, 2100891.[6] He, K. et al. (2018) Nano Energy, 49, 338–345[7] Sasaki, Y. et al. (2021) Journal of Power Sources, 481, 228831.[8] Pu, S.D. et al. (2020) ACS Energy Letters, 5, 2283–2290.[9] Balaghi, S.E. et al. (2021) ACS Applied Materials & Interfaces, 13, 19927–19937.[10] Yang, Y. et al. (2023) Nature, 614, 262-270[11] Choudhary, S. et al (2022) Journal of the Electrochemical Society, 169, 111505 Figure 1

Limosomes versus hyalurolimosomes loaded with piperine for management of skin cancer

Skin cancer is considered the fifth most commonly occurring cancer worldwide hampering both health and economy. Piperine had proven efficacy in fighting skin cancer cells. Unfortunately, this natural agent had limited ability to penetrate the skin. The aim of the current study was to formulate piperine-loaded limosomes and hyalurolimosomes incorporating limonene as an edge activator and hyaluronic acid as bioactive gelling agent for managing skin cancer. Titration method followed by homogenization was adopted to prepare the nanoliposomal formulations. Characterization involved size, & zeta potential measurements, examination using transmission electron microscope (TEM) and stability study. Biological evaluation of the antitumor activity of piperine nanoliposomal formulations against Ehrlich’s (EAC) solid tumor was also performed. Drug loaded limosomes and hyalurolimosomes had particle size; 346.55 ± 8.55 & 372.70 ± 10.83 nm, respectively. Zeta potential was high enough to ensure their stability. TEM micrographs detected the surrounding layer of Hyaluronic acid formed around the spherical limosomal nano-carrier ensuring the formation of Hyalurolimosomes. All stored formulations showed non-significant differences compared with freshly prepared ones at p < 0.05. In addition, A DAD-HPLC method was developed and validated for Piperine analysis in the skin. Upon application of this method, it was found that hyalurolimosomes deliver double the concentration delivered by limosomes. The piperine hyalurolimosome group showed a significant reduction in tumor size with a smaller AUC compared to piperine gel, which was confirmed by in vivo studies. Consequently, hyalurolimosomes loaded with piperine is considered a promising nanocarrier system and a step forward better management of skin cancer introducing new hope in beating this deadly disease.

Toxicity Evaluation of Silver Nanoparticle in the Kidneys of Wistar Rats

This study aimed to evaluate the nephrotoxic effects of silver nanoparticles (AgNPs) in Wistar rats using biochemical, oxidative stress and histopathological changes. Three groups of six rats were orally administered AgNPs once a day for 28 days with doses of 100, 500, 1000 mg/kg bodyweight. A control group was administered with deionized water. Blood and kidneys were collected 24 h after the last treatment following standard protocols. The activities of creatinine and blood urea nitrogen against AgNP-induced toxicity was determined in the serum by colorimetric microplate assay. Various activity levels of oxidative stress including, Catalase (CAT), Superoxide dismutase (SOD), Glutathione peroxidase (GPx) and Lipid hydroperoxides (LPO) were evaluated in the kidney tissue. Scanning (SEM) and transmission electron microscopy (TEM) was used to determine the histopathological evaluation of the kidneys. A significant increase in the levels of serum creatinine, blood urea nitrogen, CAT and LPO, were noted in AgNPs exposed rats compared to that in control rats. In contrast, decreased activities of SOD and GPx in a dose-dependent manner was observed in AgNPs exposed rats relative to control rats. SEM and TEM study showed significant morphological alterations in kidneys of AgNPs exposed rats in accordance with the biochemical markers. The results of the study demonstrate that AgNPs might be nephrotoxic, and its toxicity is mediated through oxidative stress mechanism.

Tuning Pd-to-Ag Ratio to Enhance the Synergistic Activity of Fly Ash-Supported PdxAgy Bimetallic Nanoparticles.

Fly ash (FA)-supported bimetallic nanoparticles (PdxAgy/FA) with varying Pd:Ag ratios were prepared by coprecipitation of Pd and Ag involving in situ reduction of Pd(II) and Ag(I) salts in aqueous medium. All the supported nanoparticles were thoroughly characterized with the aid of powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), electron microscopy (field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM)), and elemental analyses, which include inductively coupled plasma-optical emission spectroscopy (ICP-OES) and energy-dispersive X-ray spectroscopy (EDS). A gradual broadening and shifting of PXRD peaks, ascribable to Ag, to higher angles with an increase in the Pd:Ag ratio affirms the alloying of interface between Pd and Ag nanoparticles. The coexistence of Pd and Ag was further confirmed by EDS elemental mapping as well as by the presence of bimetallic lattices on the FA surface, as evident from the high-resolution TEM analysis. The dependency of crystallite size and average size of bimetallic nanoparticles on Ag loading (mol %) was elucidated with the help of a combination of PXRD and TEM studies. Based on XPS analysis, the charge transfer phenomenon between contacting Pd-Ag sites could be evident from the shifting of 3d core electron binding energy for both Pd and Ag compared with monometallic Pd and Ag nanoparticles. Following a pseudo-first-order reaction kinetics, all the nanocatalysts were able to efficiently reduce 4-nitrophenol into 4-aminophenol in aqueous NaBH4. The superior catalytic performance of the bimetallic nanocatalysts (PdxAgy/FA) over their monometallic (Pd100/FA and Ag100/FA) analogues has been demonstrated. Moreover, the tunable synergistic effect of the bimetallic systems has been explored in detail by varying the Pd:Ag mol ratio in a systematic manner which in turn allowed us to achieve an optimum reaction rate (k = 1.050 min-1) for the nitrophenol reduction using a Pd25Ag75/FA system. Most importantly, all the bimetallic nanocatalysts explored here exhibited excellent normalized rate constants (K ≈ 6000-15,000 min-1 mmol-1) compared with other supported bimetallic Pd-Ag nanocatalysts reported in the literature.

Complex magnetic behaviour and photocatalytic response in narrowed band gap NiO nanoparticles synthesized by novel Lepidagathis ananthapuramensis leaf extract

The present work focussed on the detailed investigation on structural, morphological, optical, photocatalytic, and magnetic properties of NiO nanoparticles (NPs) derived by a novel Lepidagathis ananthapuramensis leaf extract. The structural information using X-ray powder diffraction and Raman spectroscopy method indicates a single phase NiO hexagonal crystal structure for the sample calcined at ≥ 600 °C. Field emission scanning electron microscopy and high-resolution transmission electron microscopy studies noticed the various morphologies. UV–Visible, photoluminescence, and X-ray photoelectron spectroscopy confirmed the presence of both Ni2+ and Ni3+ ions with the narrowed band gap. Thorough magnetic studies indicate the existence of antiferromagnetic, ferromagnetic and superparamagnetic nature of NiO NPs. The photocatalytic activity of NiO NPs for the photocatalytic degradation of methylene blue dye in the presence of sunlight showed considerable results. This study can help us to deliver the wide range of properties which can be utilised in the field of magnetism and photocatalysis.