Electron Microscopy Studies Research Articles

Enhanced photocatalytic hydrogen production of Ag and N-doped NaTaO3 perovskite nanocubes

In the current study, a simple hydrothermal method was used to successfully synthesize NaTaO3 and Ag, N doped NaTaO3 catalysts. The band edge potential was accessible through UV–visible spectroscopic analysis, and the diffraction peak was easily indexed as an orthorhombic structure. The values of the predicted crystallite sizes for the undoped NaTaO3, Ag-doped, and N-doped NaTaO3 nanoparticles are 61.03 nm, 48.9 nm, and 53.50 nm, respectively. Pure, Ag, and N doped NaTaO3 nanocubes were discovered to exhibit band gap energies of 3.62, 3.60, and 3.57 eV, respectively, based on the UV-Vis examination. Moreover, a Field Emission Scanning Electron Microscopy study confirmed the presence of cubic (3-D) shape. An HRTEM examination verified that the material is polycrystalline. The Ta, Na, N, and O are present at binding energies of 26.09, 1073, 405.7, and 526.6 eV, respectively, according to the XPS spectra. The pure, silver (Ag), and nitrogen (N) doped NaTaO3 photocatalysts have photocatalytic H2 evolution rates of 556 µmolh−1, 2834 µmolh−1 and 3266 µmolh−1, respectively. Without a co-catalyst, the maximal rate of H2 generation under UV light has not yet been attained for the N-doped NaTaO3 perovskite with its cubic (3-D) structure. Furthermore, even after three days, the improved photocatalyst demonstrates 87 % of photocatalytic activity in the reliability test.

Orthotospovirus iridimaculaflavi (iris yellow spot virus): An emerging threat to onion cultivation and its transmission by Thrips tabaci in India

The yellow spot disease caused by the virus species Orthotospovirus iridimaculaflavi (Iris yellow spot virus-IYSV), belonging to the genus Orthotospovirus, the family Tospoviridae, order Bunyavirales and transmitted by Thrips tabaci Lindeman. At present, emerging as a major threat in onion (Allium cepa) in Tamil Nadu, India. The yellow spot disease incidence was found to be 53–73 % in six districts out of eight major onion-growing districts surveyed in Tamil Nadu during 2021–2023. Among the onion cultivars surveyed, the cultivar CO 5 was the most susceptible to IYSV. The population of thrips was nearly 5–9/plant during vegetative and flowering stages. The thrips infestation was 34–60 %. The tospovirus involved was confirmed as IYSV through DAS-ELISA, followed by molecular confirmation through RT-PCR using the nucleocapsid (N) gene. The predominant thrips species present in onion crops throughout the growing seasons was confirmed as Thrips tabaci based on the nucleotide sequence of the MtCOI gene. The mechanical inoculation of IYSV in different hosts viz., Vigna unguiculata, Gomphrena globosa, Chenopodium amaranticolor, Chenopodium quinoa and Nicotiana benthamiana resulted in chlorotic and necrotic lesion symptoms. The electron microscopic studies with partially purified sap from onion lesions revealed the presence of spherical to pleomorphic particles measuring 100–230 nm diameter. The transmission of IYSV was successful with viruliferous adult Thrips tabaci in cowpea (Cv. CO7), which matured from 1st instar larva fed on infected cowpea leaves (24 h AAP). Small brown necrotic symptoms were produced on inoculated plants after an interval of four weeks. The settling preference of non-viruliferous and viruliferous T. tabaci towards healthy and infected onion leaves resulted in the increased preference of non-viruliferous thrips towards infected (onion-61.33 % and viruliferous thrips towards healthy onion leaves (75.33 %). The study isolates shared 99–100 % identity at a nucleotide and amino acid level with Indian isolates of IYSV in the N gene. The multiple alignment of the amino acid sequence of the N gene of IYSV isolates collected from different locations and IYSV isolates from the database revealed amino acid substitution in the isolate ITPR4. All the IYSV isolates from India exhibited characteristic amino acid substitution of serine at the 6th position in the place of threonine in the isolates from Australia, Japan and USA. The phylogenetic analysis revealed the monophyletic origin of the IYSV isolates in India.

Non-Aqueous Polyhedral Liquid Marbles Stabilized with Polymer Plates Having Surface Roughness.

Hydrophobic polymer plates with smooth and rough surfaces are used as a stabilizer for cubic liquid marbles (LMs) to study the effect of surface roughness on their formation. The smooth and rough polymer plates can stabilize LMs using liquids with surface tensions of 72.8-26.6 and 72.8-22.9 mNm-1, respectively. It is clarified that the higher the surface roughness, the lower the surface tension of the liquids are stabilized to form the LMs. These results indicated that the introduction of surface roughness improves the hydrophobicity of the polymer plates and the rough polymer plates can stabilize LMs using liquids with a wider surface tension range. Electron microscopy studies and numerical analyses confirmed that the LMs can be formed, when the Cassie-Baxter wetting state, where θY>90° (θY: the contact angle on smooth surfaces) and θR>90° (θR: the contact angle on rough surfaces), and the metastable Cassie-Baxter wetting state, where θY<90° and θR>90°, are realized. Finally, the synthesis of cubic polymer particles are succeeded by free radical polymerization of the cubic LMs containing a hydrophobic vinyl monomer (dodecyl acrylate) in a solvent-free manner.

Catalytic Graphitization by Nickel Nitrate and Characterization on Palm Oil Solid Waste Graphite

Abstract Catalytic graphitization of biomass has been extensively studied. The conventional graphitization method uses high temperatures and non-renewable carbon sources. Temperatures below 1000°C was used in biomass graphitization. The aim of this study is to how these variables affect the structural and morphological properties of the graphite materials produced. In graphite production process, catalyst impregnation is followed by heat treatment. The graphitization process starting with amorphous carbon nanospheres, is investigated by Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) studies. XRD was used to examine the graphitization behavior of palm oil solid waste. Based on the result, the position of the 2 theta peak intensity on the XRD graph of the Ni graphitized sample is extremely near to that on the XRD graph of the raw material and carbon sample. The morphological changes that occur in the SEM images for materials graphitized with nickel nitrate are characterized by structures comparable to those that occur in carbon samples. The circular structures in the graphitized sample are anisotropic and structured without orientation bias.

Microwave assisted synthesis of α-Fe2O3 half-hexagon nanoplates as an anode material for Li ion batteries

In this study, hematite α-Fe2O3 half-hexagon nanoplates have been successfully prepared by ethanol–water mediated microwave assisted solvothermal method. The high crystalline nature and rhombohedral crystal structure of the synthesized α-Fe2O3 were confirmed from X-ray diffraction (XRD) results. No impurity phase other than hematite α-Fe2O3 was detected. Raman spectroscopy results further revealed the hematite structure of α-Fe2O3. X-ray photoelectron spectroscopy (XPS) study disclosed the chemical composition and valence states in the synthesized α-Fe2O3 material. Field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM) studies confirmed the half-hexagon plate like architecture for α-Fe2O3 along with some irregular shape nanoplates. When treated as an anode material for Li ion battery (LIB), α-Fe2O3 half-hexagon nanoplates delivered a reversible discharge capacity of 520 mAh.g−1 after 100 cycles at a high current density of 500 mA.g−1. The α-Fe2O3 half-hexagon nanoplates also exhibited excellent cycling performance and coulombic efficiency. The excellent performance of the α-Fe2O3 electrode is mainly ascribed to the plate like morphology of the particles, which offers large effective contact area with the electrolyte and significantly enhances the electrochemical performance.

Study of the Optical and Structural Properties of Metal-Doped Titanium Dioxide Electrode Prepared by the Sol-Gel Method for Dye-Sensitized Solar Cells

This study presents a strategy to increase the efficiency of dye-sensitized solar cells (DSSCs) by doping titanium dioxide (TiO2) with different magnesium (Mn) concentrations (1, 3, 5, 7, and 9%) generated by the sol-gel process and effectively employed as a photo-anode (the working electrode) for DSSCs. The Doctor Blade method coated the indium-doped tin oxide (ITO) glass with a thin film layer. X-ray diffraction (XRD) was used to evaluate the characteristics of undoped and manganese-doped TiO2, and the results demonstrate that all of the thin films are anatase. The samples were examined using XRD to assess grain size before and after Mn doping. The spectrum of UV-Vis absorption changes; accordingly, as doping increases, the energy gap decreases. The smallest energy gap's value (2.4 eV) is 7% manganese doping. AFM pictures show the average roughness and root mean square of the weight percentage of films doped with 5%. Field effect scanning electron microscope (FE-SEM) studies show that the particle size of thin films gets smaller as more Mn is added, which happens at least as much as 7% Mn doping. The optimal thickness for TiO2 paste over conductive glass is 15 μm, and the cell's power conversion efficiency increased to 0.604074% with an Imax of 4.965 mA, a Vmax of 0.488 V, and a fill factor (FF) of 68.45954%.

Resveratrol and prednisolone loaded into human serum albumin nanoparticles for the alleviation of rheumatoid arthritis symptoms: an in vitro and in vivo study

Abstract Rheumatoid arthritis is a chronic autoimmune-disease-causing inflammation, joint pain, and joint destruction, severely affecting the quality of life of millions worldwide. In the current research, a nanocarrier system was developed for the delivery of resveratrol and prednisolone to treat rheumatoid arthritis. The drug delivery system was characterized in vitro using scanning electron microscopy and various cell culture studies. Finally, the alleviative symptoms of the developed treatment strategy were investigated in a rat model of rheumatoid arthritis. In vitro studies showed that the carrier system released the drugs in a sustained manner and possessed strong immunomodulatory functions. Nanocarriers loaded with prednisolone, resveratrol, and drug-free carriers had 396.88 ± 76.41 nm, 392.49 ± 97.31 nm, and 338.02 ± 77.75 nm of mean particle size, respectively. In vivo studies revealed that local injection of the carrier system could alleviate the degenerative effects of rheumatoid arthritis. ELISA assays showed that the co-injection of resveratrol and prednisolone-loaded albumin nanoparticles could significantly modulate inflammatory responses. The developed treatment modality may potentially be used to treat rheumatoid arthritis.

Sustainable self-Compacting concrete with marble slurry and fly ash: Statistical modeling, microstructural investigations, and rheological characterization

The escalating generation of marble waste and the substantial carbon footprint associated with cement production pose significant environmental challenges. Thus, by substituting fly ash for supplementary cementitious material and using leftover marble waste for fine aggregate in concrete can reduce cost and carbon emissions that may lead to sustainable development. The presented paper aims to study the effect of partial substitution of marble slurry with natural fine aggregates and fly ash as supplementary cementitious material (SCM) on Self-Compacting Concrete (SCC). Polycarboxylate Ether (PCE) based superplasticizer (SP) was added in the concrete mix, to decrease the demand of higher water to binder (w/b) ratio. After developing SCC, fresh state properties and compressive strength (CS) at the curing age of 7 and 28 days were evaluated. To maximize the utilization of marble slurry and fly ash, mixture optimization was performed using the Box-Behnken Design (BBD), a robust technique within the response surface methodology (RSM) framework. Rheological analysis was performed to analyse the fresh state behaviour of the SCC with the help of the Bingham and Modified Bingham (MB) models. Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) studies were also carried out to study the behaviour of the marble slurry and fly ash in the concrete. Carbon emission and cost analysis of SCC was evaluated at different replacement level of the marble slurry and fly ash. It was inferred that marble slurry and fly ash can be used in the certain percentages without compromising any strengthen and flowability properties of the SCC. The rheological behaviour also confirmed that linear and nonlinear behaviour of SCC in the certain mix proportion may results in the formation of the stable SCC. The analysis of cost and carbon emission confirmed that sustainable SCC mixture achieved substantial reductions of 21.44 % in cost and a remarkable 47.71 % decrease in carbon dioxide (CO2) emissions compared to conventional concrete.

Isolation, screening, and characterization of polyhydroxyalkanoate (PHA)‐producing Cellulosimicrobium cellulans: A promising approach for eco‐friendly biopolymer production

AbstractThe replacement of synthetic plastics with eco‐friendly biopolymers is a notable approach in the modern world. Polyhydroxyalkanoates (PHAs) have gained a lot of attention among researchers in recent decades. This study aimed to isolate and screen microorganisms capable of producing PHA from composite samples. Several composting unit samples were collected and used to isolate 15 distinct colonies which were then screened for PHA synthesis. Three isolates‐SS2, SSNA 1a, and SF2‐showed promising PHA production. Among these isolates, SS2 had the highest PHA content of 70.1%. The isolate SS2 was determined as Cellulosimicrobium cellulans DSM 43879 by gene sequencing. The polymer produced by SS2 was further characterized. The presence of carbonyl groups and ester linkages in the PHA polymer was established by Fourier transform infrared analysis. The polymer's crystalline nature was validated by X‐ray powder diffraction measurement. Scanning electron microscope study revealed thread‐like forms with a rough surface while energy dispersive X‐ray analysis revealed a low impurity content that was primarily composed of carbon and oxygen with traces of other elements. Overall, the findings indicate C. cellulans potential as an ideal candidate for efficient PHA synthesis supporting its commercial potential in diverse applications.

Mitochondrial dysfunction significantly contributes to the sensitivity of tumor cells to anoikis and their metastatic potential

It is well-known that the survival of metastatic cells during their dissemination plays an important role in metastasis. However, does this mean that the final result of the metastatic cascade (the volume of metastatic damage to distant organs and tissues) depends on, or at least correlates with, the degree of resistance to anoikis (distinctive hallmarks of metastatic cells)? This question remains open.The aim of the work was to study in vitro the changes in the survival rates, proliferative activity, oxidative stress, and glycolysis intensity during three days of anchorage-dependent and anchorage-independent growth of two Lewis lung carcinoma cell lines (LLC and LLC/R9) and compare these changes with the status of mitochondria and metastatic potential of the cells in vivo. MethodsThe number and volume of lung metastases were estimated for each cell line after intramuscular inoculation of the cells in C57Bl/6 mice. For the in vitro study, the cells were seeded on Petri dishes pretreated with poly-HEMA or untreated dishes and then allowed to grow for 3 days. Cell viability, cell cycle progression, the level of reactive oxygen species (ROS), glucose consumption and lactate production rates were investigated daily in both growth conditions. An electron microscopy study of intracellular structures was carried out. ResultsThe study showed (as far as we know for the first time) a correlation between the metastatic potential of cells (determined in vivo) and their sensitivity to anoikis (assessed in vitro). The transition of LLC/R9 cells with an inherently defective mitochondrial system to the conditions of anchorage-independent growth was characterized by a decrease in survival, a slowdown in growth rates, an increase in both glucose consumption rate and intracellular ROS levels and manyfold lower metastatic potential, compared to highly metastatic LLC cells with the normal mitochondrial system.

Ovarian balls (Floating ovaries) of Rhadinorhynchus niloticus Mohamadain, 1989 from the Nile perch Lates niloticus Linnaeus, 1758; an electron microscope study.

In Acanthocephala, the ovarian balls (floating ovaries) are distinctive structures found suspended in the fluid-filled metasoma of females and are responsible for egg production and maturation. Those structures have not been studied in Rhadinorhynchus niloticus. We aimed to investigate their ultra-structure by means of scanning and transmission electron microscopy. A total of 30 Lates niloticus fish individuals were collected by fishermen from the River Nile, Egypt, and the isolated adult female specimens were processed for electron microscopy studies. The ovarian balls are elongated and lobulated structures freely scattered in the metasoma. They exhibited three distinct primary structural zones, a central oogonial syncytium, a peripheral cellular zone and a surrounding somatic supporting syncytium. The oogonia, within the central syncytium, give rise to developing oocytes that transform into mature oocytes. The latter enclose some inclusions such as large yolk granules and smaller egg-shell granules. We also describe the process of fertilization within the ovarian ball. The structure of the ovarian ball and the steps of fertilization in R. niloticus are described, for the first time, in the present study.

Recent progresses in transmission electron microscopy studies of two-dimensional ferroelectrics

The rich potential of two-dimensional materials endows them with superior properties suitable for a wide range of applications, thereby attracting substantial interest across various fields. The ongoing trend towards device miniaturization aligns with the development of materials at progressively smaller scales, aiming to achieve higher integration density in electronics. In the realm of nano-scaling ferroelectric phenomena, numerous new two-dimensional ferroelectric materials have been predicted theoretically and subsequently validated through experimental confirmation. However, the capabilities of conventional tools, such as electrical measurements, are limited in providing a comprehensive investigation into the intrinsic origins of ferroelectricity and its interactions with structural factors. These factors include stacking, doping, functionalization, and defects. Consequently, the progress of potential applications, such as high-density memory devices, energy conversion systems, sensing technologies, catalysis, and more, is impeded. In this paper, we present a review of recent research that employs advanced transmission electron microscopy (TEM) techniques for the direct visualization and analysis of ferroelectric domains, domain walls, and other crucial features at the atomic level within two-dimensional materials. We discuss the essential interplay between structural characteristics and ferroelectric properties on the nanoscale, which facilitates understanding of the complex relationships governing their behavior. By doing so, we aim to pave the way for future innovative applications in this field.

Comparative macroanatomical and scanning electron microscopy study of the eyeball in brachycephalic and mesocephalic dog breeds.

The anatomical structures forming the eyeball differ among dog breeds, both morphologically and morphometrically. This study was aimed at determining the morphometric values of the eyeball layers of different dog breeds and the morphological structures of these layers using scanning electron microscopy. Thirty-two eyeballs of 17 dogs belonging to 9 different breeds that died from traffic accidents, falling from a height, and naturally were used. These dog breeds were grouped according to their brachycephalic and mesocephalic skull structures, and morphometric measurements of the eyeballs of each group were obtained. Scanning electron microscopy was used to examine the morphological structure of the eyeball layers. The studied dogs' eyeballs comprised three layers: outer, middle, and inner. Thickness measurements obtained from three different regions of the eyeball indicated that the equatorial region was the thinnest among all dog breeds. Moreover, the cornea, which is covered by the sclera along its edges, was thicker at the corneal limbus than at the corneal vertex. A positive correlation was observed between lens thickness and the number of ciliary processes, which varied according to the dogs' head structures. Notably, depression was observed in the posterior surface of the lens in brachycephalic dogs. The morphometric values of the eyeball layers in the brachycephalic and mesocephalic dog breeds were also determined. These values will help researchers study this subject, and the determined morphometric and morphological values will contribute to the anatomy literature. RESEARCH HIGHLIGHTS: This comprehensive study investigates the morphometric and morphological variations in the eyeball layers of different dog breeds, utilizing scanning electron microscopy to analyze eyeballs. It reveals significant breed-specific differences, particularly between brachycephalic and mesocephalic dogs, regarding eyeball layer thickness, corneal structure, lens thickness, and the number of ciliary processes.

Nanoscale cellular organization of viral RNA and proteins in SARS-CoV-2 replication organelles

The SARS-CoV-2 viral infection transforms host cells and produces special organelles in many ways, and we focus on the replication organelles, the sites of replication of viral genomic RNA (vgRNA). To date, the precise cellular localization of key RNA molecules and replication intermediates has been elusive in electron microscopy studies. We use super-resolution fluorescence microscopy and specific labeling to reveal the nanoscopic organization of replication organelles that contain numerous vgRNA molecules along with the replication enzymes and clusters of viral double-stranded RNA (dsRNA). We show that the replication organelles are organized differently at early and late stages of infection. Surprisingly, vgRNA accumulates into distinct globular clusters in the cytoplasmic perinuclear region, which grow and accommodate more vgRNA molecules as infection time increases. The localization of endoplasmic reticulum (ER) markers and nsp3 (a component of the double-membrane vesicle, DMV) at the periphery of the vgRNA clusters suggests that replication organelles are encapsulated into DMVs, which have membranes derived from the host ER. These organelles merge into larger vesicle packets as infection advances. Precise co-imaging of the nanoscale cellular organization of vgRNA, dsRNA, and viral proteins in replication organelles of SARS-CoV-2 may inform therapeutic approaches that target viral replication and associated processes.

Revitalising Dentin Surfaces: Unlocking Periodontal Regeneration Potential through Cutting-edge Citric Acid Techniques

Introduction: Teeth affected by periodontitis exhibit an increased mineral content and endotoxins. They do not harmonise with the neighbouring periodontal cells, whose growth is essential for periodontal regeneration. This scanning electron microscope (SEM) study evaluated and compared the in vitro effects of different citric acid application techniques on naturally preserved dentin slabs. Materials and Methods: Thirty-two dentinal slabs were prepared for experimentation, with one group undergoing various treatments and a control group left untreated. The citric acid solution, with a pH of 1.0, was meticulously prepared and used in four different application methods on the experimental group. The dentin slabs were prepared for SEM evaluation, which assessed parameters such as exposed dentinal tubules, the surface area occupied by tubule orifices, the demineralised zone’s width and the exposed tubules’ morphological characteristics. Results: The data present the mean number of exposed dentinal tubules for different application techniques and the width of the demineralised zone. While the f-test did not show significant differences in the width of the demineralised zone, the number of exposed dentinal tubules varied significantly. Immersion treatment resulted in the highest number of open tubules, followed by cotton pellet placement and brushing. Conclusions: The study suggests that in periodontal regenerative procedures, passive citric acid application may be more effective than vigorous methods like burnishing for exposing inter-tubular fibrils and dentinal openings.

Ni Single Atom Decorated Porous Hollow Carbon Nanosphere-Based Electrodes for High Performance Symmetric Solid-State Supercapacitors.

Ni single atom containing hollow carbon nanospheres with nitrogen doping has been synthesized by carbonization of Ni(NO3)2/phloroglucinol-formaldehyde polymer/silica composite. The samples have been characterized by powder X-ray diffraction, nitrogen adsorption/desorption, electron microscopic, Raman and X-ray photoelectron spectroscopic studies. The microstructure and surface area vary with the amount of Ni(NO3)2 employed in the syntheses and the carbonization environment. An optimized amount of nickel and argon as the carbonization gas afford Ni-1.0@N@HCN-Ar which possesses overall superior features. The uniformly dispersed Ni single atoms within the hollow porous carbon framework fully utilize all the electroactive sites thereby improving the supercapacitive performance. The specific capacitance of Ni-1.0@N@HCN-Ar reaches 777 F g-1 at 1 A g-1 with a Coulombic efficiency of 98.4 % and excellent recyclability. The energy and power density of Ni-1.0@N@HCN-Ar are found to be high; at 1 A g-1 its energy density is 155.4 Wh kg-1 with a power density of 600.3 W kg-1. At a high current density of 10 A g-1 the material shows a high energy density of 118.4 Wh kg-1 with excellent power density of 6003.4 W kg-1. A symmetric solid-state supercapacitor assembled with this material, Ni-1.0@N@HCN-Ar//Ni-1.0@N@HCN-Ar using H2SO4/PVA gel electrolyte shows a superior energy density value of 30 Wh kg-1 at a power density of 1200 W kg-1.

Quasi-operando Transmission Electron Microscopy Diagnostics for Electrocatalytic Processes in Liquids.

The need to relate the mechano-physico-chemical phenomena in liquid-based electrocatalysts to the stages of start-up, operation, and shut-down phases is one of the major challenges that the energy community is facing. Understanding these phenomena will pave the way for the tailor-made design of efficient, commercially viable electrocatalytic systems. Transmission electron microscopy plays an important role in the investigation of local electrocatalytic effects, complementing other operando characterization techniques. Herein, after attempting to define the meaning of operando methodologies in relation to electron microscopy studies, the progress in the field is reviewed in terms of the knowledge gained about the catalysts, the solid-liquid interfaces, and the solid-liquid-gas interfacial phenomena for several electrocatalytic reactions. Finally, the parameters that require consideration in operando ec-LPTEM studies of electrocatalytic systems are discussed.

Dynamic links between the cardiac intermediate filaments of the cytoskeleton and nucleoskeleton for proper cardiomyocyte differentiation, maturation and reprogramming

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): 1) ESPA 09SYN-21-966 2) ELIDEK 1594 Accumulating evidence suggests that mechanical forces are integral to the commitment and differentiation of cardiac stem cells. Studies have proposed that the cardiac cytoskeleton and specifically the desmin intermediate filament (IF) network and its association with nuclear lamins through the LINC complex, link the contractile apparatus to both the extracellular and nuclear matrix, thus regulating trafficking processes and mechanotransduction during development and adulthood, governing myocyte homeostasis and survival(1-3). Desmin, in addition to being one of the earliest myogenic markers both in heart and somites(4,5), regulates nuclear shape and positioning(6,7), as well as the expression of myogenic (MyoD, Myogenin)(8) and cardiogenic (MEF2, Nkx2.5) transcription regulators, during embryonic stem cell differentiation(4,5). Consistent with the above findings, desmin deficiency has negative impact in the proper regeneration of skeletal muscle cells by hematopoietic stem cells(9). Despite these overwhelming data linking desmin to the establishment and maintenance of myogenesis and cardiogenesis, the precise underlying mechanisms remain elusive. To dissect the exact mechanism of cardiogenic regulation we took advantage of the fibroblast-to-cardiomyocyte direct reprogramming, where fibroblasts trans-differentiate into functional induced cardiomyocytes (iCM) through ectopic expression of three transcription factors, GATA4, Mef2C and Tbx5 (GMT)(10). We hypothesized that desmin could enhance the reprogramming of fibroblasts into cardiomyocytes. Indeed, we have found that expression of desmin together with the GMT factors increases reprogramming by 40-60%. Involvement of a cytoskeletal protein such as desmin in cell differentiation and potentially regeneration, raises intriguing questions and exciting possibilities. To unravel the mechanism of this enhancement we focused on desmin serving as direct mechanotransducer (through the LINC complex) to chromatin. Toward this goal, we investigate the changes of the genetic profile induced by the GMT cocktail during reprogramming in the presence or absence of desmin. RNA sequence analysis has shown that the Notch developmental pathway is regulated by desmin. With the use of Chromosome Conformation Capture, Hi-C and Chip-sequence analysis, we demonstrated the importance of desmin cytoskeleton on the genome 3D organization. In addition, we show that desmin is expressed in most of the cardiac progenitor cells population declaring its role in proper cardiac formation. Moreover, immunofluorescence, calcium influx and electron microscopy studies establish desmin as a major player for cardiac maturity, a critical subject in cardiac regenerative medicine, since its absence substantial reduces expression and proper localization of cardiac specific proteins, delays myofibril formation and impairs function of the induced cardiomyocytes driving most of them to senescence. All the above data will be presented.

Borides Mn3-x{Rh,Ir}5B2 with Ti3Co5B2-type: X-ray single crystal and TEM data, physical properties

A cursory investigation of the phase relations in the Mn-{Rh,Ir}-B systems prompted for each system a ternary compound, Mn3-x{Rh,Ir}5B2, the crystal structure of them was determined from X-ray single crystal data to be isotypic with the Ti3Co5B2-type (space group P4/mbm, No. 127). In both cases the Mn-site in 2a at the origin of the unit cell exhibits a significant defect (or Mn/B substitution). Transmission electron microscopy studies confirm the absence of a superstructure related to these defects/disorder. The two phases, Mn3-xRh5B2 (x∼0.34) and Mn3-xIr5B2 (x∼0.85) at 950 °C show rather limited homogeneity regions pointing towards higher Mn-contents. Whereas temperature dependent magnetization and specific heat measurements of Mn2.15Ir5B2 do not reveal any indication for a magnetic phase transition in the temperature range from 3 to 300 K, a broad specific heat anomaly at around 200 K and a tilde shape of the temperature dependent magnetization of Mn2.66Rh5B2 appears indicative of an antiferromagnetic phase transition. The latter is also reflected by an anomaly of the electrical resistivity (ρ; 4–300 K) of Mn2.66Rh5B2 which displays a non-monotonous temperature dependence, whereas ρ(T) of Mn2.15Ir5B2 displays a simple metallic-like behavior dominated by scattering from defects. Elastic moduli and Poisson's ratio were determined at room temperature from Resonant Ultrasonic Spectroscopy (RUS) data yielding Young's moduli of E ∼ 170 GPa for Mn2.66Rh5B2 and E ∼ 210 GPa for Mn2.15Ir5B2. Vickers hardness HV is lower for Mn2.66Rh5B2 (HV = 590 ≅ 5.79 GPa) than for Mn2.15Ir5B2 (HV = 655 ≅ 6.42 GPa). The indentation fracture toughness for Mn2.15Ir5B2 was IKC = 0.71 ± 0.5 MPa m1/2.

Enhanced photo-electro catalytic CO2 conversion using transition metal doped TiO2 nanoparticles

The Fe, Co, and Ni-doped TiO2 were synthesised by sol–gel process, and the nanomaterials were coated on electrodes through a slurry with Nafion. This study aims to use prepared nanoparticles of Fe, Co, and Ni-doped TiO2 to enhance the photo-electrocatalytic conversion of CO2. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), and electrochemical analyses were utilized to characterise the doped and undoped TiO2 nanoparticles. Transmission electron microscopy (TEM) studies revealed that the nanomaterials had an average size below 20 nm. Tauc plot analysis for optical absorption studies shown a reduction in band gap when doped with Fe, Co and Ni, with the most significant decrease observed for Fe-doped TiO2, following the order Fe < Co < Ni. Electrochemical CO2 conversion efficiencies were investigated through cyclic voltammetry (CV) curves, electrochemical impedance spectroscopy (ESI), and linear sweep voltammetry (LSV) studies. The results were analysed based on various scan rates and photo exposure, indicating superior performance for Fe-TiO2, aligning with the observed band gap trends. Gas chromatography (GC) analysis of the reduction products revealed the generation of hydrocarbons, with Fe-TiO2 exhibiting the most favourable outcomes. This research provides valuable insights into tailoring TiO2 nanoparticles for efficient photo-electro catalytic reduction of CO2.