Characteristics Of Nanostructures Research Articles

Targeted anti-tumor synergistic effects of Myc decoy oligodeoxynucleotides-loaded selenium nanostructure combined with chemoradiotherapy on LNCaP prostate cancer cells.

In the present study, we investigated the synergistic effects of targeted methotrexate-selenium nanostructure containing Myc decoy oligodeoxynucleotides along with X-irradiation exposure as a combination therapy on LNCaP prostate cancer cells. Myc decoy ODNs were designed based on the promoter of Bcl-2 gene and analyzed by molecular docking and molecular dynamics assays. ODNs were loaded on the synthesized Se@BSA@Chi-MTX nanostructure. The physicochemical characteristics of nanostructures were determined by FTIR, DLS, UV-vis, TEM, EDX, in vitro release, and hemolysis tests. Subsequently, the cytotoxicity properties of them with and without X-irradiation were investigated by uptake, MTT, cell cycle, apoptosis, and scratch assays on the LNCaP cell line. The results of DLS and TEM showed negative charge (-9 mV) and nanometer size (40 nm) for Se@BSA@Chi-DEC-MTX NPs, respectively. The results of FTIR, UV-vis, and EDX showed the proper interaction of different parts and the correct synthesis of nanoparticles. The results of hemolysis showed the hemocompatibility of this nanoparticle in concentrations less than 6 mg/mL. The ODNs release from the nanostructures showed a pH-dependent manner, and the release rate was 15% higher in acidic pH. The targeted Se@BSA@Chi-labeled ODN-MTX NPs were efficiently taken up by LNCaP cells by targeting the prostate-specific membrane antigen (PSMA). The significant synergistic effects of nanostructure (containing MTX drug) treatment along with X-irradiation showed cell growth inhibition, apoptosis induction (~57%), cell cycle arrest (G2/M phase), and migration inhibition (up to 90%) compared to the control. The results suggested that the Se@BSA@Chi-DEC-MTX NPs can potentially suppress the cell growth of LNCaP cells. This nanostructure system can be a promising approach for targeted drug delivery and chemoradiotherapy in prostate cancer treatment.

Synthesis and investigation; influence of Mn doping on biological, optical, dielectric and electrochemical characteristics of Bi2O4 nanostructures

In this research, bismuth oxide thin films were synthesized with the variation of Mn dopant (1-5 wt %) on a glass slide by sol-gel dip coating method. XRD corroborated the creation of a monoclinic phase for all the samples after annealing at 450 °C for 4 h. The non-uniform cuboid-like granular structures were observed by SEM with a significant number of grain boundaries. Different functional groups were examined by using FTIR spectroscopy. The optical band gap was reduced from 2.01 to 1.81eV by increasing the concentration of Mn dopant. The contribution of grain and grain boundaries to the material electrical response in various frequency ranges was distinguished by impedance analysis. The polaron mechanism was used to investigate conductivity with time variation. The efficiency of supercapacitors was significantly enhanced by using the monoclinic Bi2O4 phase of bismuth oxides, promoting the specific capacitance in the range of 2518.2–6890.2 Fg-1 with high energy and power density. That leads them to the fabrication of supercapacitors in advanced electronic devices. Magnetic analysis showed that saturation magnetization and remanent frequency decreased while coercivity of thin films increased with increasing Mn concentration which was successfully explained by the critical size effect and Néel's collinear two sub-lattice models, making them plausible candidates in spintronics. As from photocatalyst analysis, the number of reactive oxygen species ROS was increased by increasing Mn doping in the Bi2O4 crystal lattice. These species degraded the water pollutants under simple exposure to sunlight (i-e visible range). The production of ROS in the photocatalytic process was also correlated with antibacterial activity. Mn-doped Bi2O4 was found to be more effective towards K. pneumonia than other bacteria. The prepared Mn:Bi2O4 nanostructures with a higher percentage of manganese were effectively used for the treatment of bloodstream infections, meningitis, pneumonia, and urinary tract infections and stopped further bacterial growth.

High-Thermal Stable Epoxy Resin through Blending Nanoarchitectonics with Double-Decker-Shaped Polyhedral Silsesquioxane-Functionalized Benzoxazine Derivatives.

A series of di-functional benzoxazine (BZ) monomers was synthesized, specifically the double-decker silsesquioxane (DDSQ) cage structure (DDSQ-BZ). Comparative analyses were conducted between DDSQ-BZ monomers and the most commonly utilized bisphenol A-functionalized bifunctional benzoxazine (BPA-BZ) monomer. DDSQ-BZ compounds possess better thermal properties such as high char yield and high thermal decomposition temperature (Td10) after thermal ring-opening polymerization (ROP) because the inorganic DDSQ cage nanostructure features a nano-reinforcement effect. In addition, blending inorganic DDSQ-BZ compounds with epoxy resin was explored to form organic/inorganic hybrids with enhanced thermal and mechanical properties following thermal ROP. The improvement in mechanical properties is primarily attributed to the network structure formed by the cross-linking between DDSQ-BZ and the epoxy resin during thermal ROP, as well as hydrogen bonding interactions formed between the hydroxyl groups generated during thermal ROP and the Si-O-Si bonds in the DDSQ structure.

Recent Research Progress on Black Carbon Emissions from Marine Diesel Engines

Black carbon (BC) emissions from shipboard diesel engines are the next potentially important issue of interest to the International Maritime Organization (IMO) and are considered to have a significant impact on the climate environment and human health. However, theories and technologies regarding the mechanisms of black carbon formation, oxidizing and influencing factors, emission detection methods, and abatement techniques are still missing in science and engineering. This paper provides a comprehensive overview of relevant advances in international maritime regulations, the frontier theory on formation mechanisms, comprehensive physical and chemical properties, and the potential reduction measures and control measures of emissions. These results suggest that BC is produced in the combustion flame of fuel and is related to the nucleation as well as the formation of PAHs. It helps to understand the initial generation process of black carbon and reduce its emission by studying it in detail and revealing some key factors, including micromorphology, nanostructural features, surface functional groups, oxidizing activity, size distribution, and elemental composition. Further, an in-depth understanding of the complex characteristics of BC can also help to identify viable BC measurement techniques and instrumentation for marine engines, thereby enhancing emission regulation. Overall, extensive technology can reduce BC emissions from marine diesel engines by approximately 50%. The information contained in this report can be used as a significant reference to further explore the BC formation mechanism and develop exclusive BC emission control strategies.

Constructing quasi-2D amorphous MnSiO3@C toward stable and high lithium storage

Featuring of high theoretical capacity, non-toxic, low-cost, and environmental benignity, metal silicates attract great attention as viable alternative anodes of lithium-ion battery. But, they show serious electrochemical irreversibility during cycle due to large volume variation and low conductivity. Herein, a novel and facile method is developed to synthesize a quasi-2 dimensional (2D) amorphous MnSiO3/C composite (A-MnSiO3@C), consisting of ultra-thin conformal carbon coated amorphous MnSiO3 quasi-nanosheets. Therefore, the A-MnSiO3@C innovatively integrates the structural characteristics of amorphous structure, 2D nanostructure and ultra-thin conformal carbon coating through a simple process. The structure-property correlations of the A-MnSiO3@C during lithium storage have been expounded systematically. The findings indicate that these structural characteristics offer A-MnSiO3@C enhanced electrical conductivity, improved Li+ transport kinetics, high capacitive contribution and good structural stability during cycle, and hence alleviate the issues MnSiO3 suffered from. As a result, the A-MnSiO3@C demonstrates outstanding lithium storage properties such as high capacity, good rate capability and long cycle durability, with 511.2 and 416.5 mAh g−1 after 400 and 600 cycles at 200 and 1000 mA g−1, respectively. Finally, this work offers a constructive reference for improving electrochemical performance of the other promising metal silicate anodes.

Extracellular Matrices as Bioactive Materials for In Situ Tissue Regeneration.

Bioactive materials based on a nature-derived extracellular matrix (NECM) represent a category of biomedical devices with versatile therapeutic applications in the realms of tissue repair and engineering. With advancements in decellularization technique, the inherent bioactive molecules and the innate nano-structural and mechanical properties are preserved in three-dimensional scaffolds mainly composed of collagens. Techniques such as electrospinning, three-dimensional printing, and the intricate fabrication of hydrogels are developed to mimic the physical structures, biosignalling and mechanical cues of ECM. Until now, there has been no approach that can fully account for the multifaceted properties and diverse applications of NECM. In this review, we introduce the main proteins composing NECMs and explicate the importance of them when used as therapeutic devices in tissue repair. Nano-structural features of NECM and their applications regarding tissue repair are summarized. The origins, degradability, and mechanical property of and immune responses to NECM are also introduced. Furthermore, we review their applications, and clinical features thereof, in the repair of acute and chronic wounds, abdominal hernia, breast deformity, etc. Some typical marketed devices based on NECM, their indications, and clinical relevance are summarized.

Microwave-assisted synthesis of zinc oxide nanoflowers for improving the rheological and filtration performance of high-temperature water-based drilling fluids

Zinc Oxide (ZnO) nanostructures have proved useful across a wide range of applications like medical technology, electronics, sulfur removal as well as microbial growth control. In the petroleum industry, ZnO nanostructures have been widely researched for application in Drilling Fluids. ZnO has been previously reported to work excellently in enhancing the electrical and thermal properties of water-based drilling fluids (WBDFs). However, the role of morphological features of the nanostructures in influencing the properties of bentonite-laden WBDFs is less understood. In this work, ZnO nanostructures were synthesized under microwave irradiation which resulted in different shapes like rods and flowers. The effect of microwave power and time was observed with Field Emission Scanning Electron Microscopy (FE-SEM) and Dynamic Light Scattering (DLS), and a suitable synthesis criterion was selected for achieving the smallest complex ZnO nanoflowers. These nanoflowers were further characterized for functional group and structural identification. Bentonite/Polymer Nanofluids were prepared and tested for properties like rheology, API, and HPHT filtration before and after thermal aging at 150 °C. The results show ZnO nanoflowers in WBDFs have excellent filtration control ability with ∼56% reduction in HPHT filtrate volume and can impart a flat-line rheological profile. Also, the breaking of nanoflowers into smaller nanorods and some further textural changes is predicted to enhance the stability of the WBDFs due to better dispersion and compact mud cake formation. The study shows that the morphological features of metal oxide nanostructures can be controlled with microwave irradiation and play an effective role in controlling the properties of bentonite/polymer WBDFs.

Morphology of Nanostructured Tantalum Oxide Controls Stem Cell Differentiation and Improves Corrosion Behavior.

Tantalum is receiving increasing attention in the biomedical field due to its biocompatible nature and superior mechanical properties. However, the bioinert nature of tantalum still poses a challenge and limits its integration into the bone tissue. To address these issues, we fabricated nanotubular (NT), nanocoral (NC), and nanodimple morphologies on tantalum surfaces via anodization. The size of these nanofeatures was engineered to be approximately 30 nm for all anodized samples. Thus, the influence of the anodized nanostructured morphology on the chemical and biological properties of tantalum was evaluated. The NT and NC samples exhibited higher surface roughness, surface energy, and hydrophilicity compared to the nonanodized samples. In addition, the NT samples exhibited the highest corrosion resistance among all of the investigated samples. Biological experiments indicated that NT and NC samples promoted human adipose tissue-derived mesenchymal stem cell (hADMSC) spreading and proliferation up to 5 days in vitro. ALP, COL1A1, and OSC gene expressions as well as calcium mineral synthesis were upregulated on the NT and NC samples in the second and third weeks in vitro. These findings highlight the significance of nanostructured feature morphology for anodized tantalum, where the NT morphology was shown to be a potential candidate for orthopedic applications.

A generalized functions based approach for stress-driven nanobeam bending problems subjected to point loads

The research community has widely accepted the stress-driven nonlocal integral model to study static and dynamic characteristics of nanostructures. Although closed-form solutions for stress-driven point-loaded nanobeam bending problems that find potential for applications in the design of real-world MEMS/NEMS-based sensors have been explored recently, the static bending behavior of stress-driven Bernoulli-Euler and Timoshenko nanobeams subjected to point-loading conditions in various end configurations are studied in the present work wherein, analytical solutions for the same are arrived at by expressing the input bending and shear fields in terms of generalized functions for the first time. Equipped with the Helmholtz bi-exponential kernel function to model the nonlocality, the obtained solutions have demonstrated their ability to capture size-effects consistently. An overall stiffening effect on the nanobeam is observed as a consequence of these size-effects.

Facile green synthesis of Phyllanthus emblica extract based Ag-NPs for antimicrobial and response surface methodology based catalytic reduction applications

Silver nanostructures were synthesized by utilizing facile and simple green methodology based on the usage of biogenic Phyllanthus emblica fruit extract. The Fourier transform infrared spectroscopy revealed that the numerous phytochemicals were found to be present in the extract that were responsible for reducing the precursor salt into nanoparticles. After 10 min, the silver nanoparticles were formed in the system while the further nucleation for 30 min resulted in the generation of the silver nanostructures with dual morphology (spherical & rod-like morphology). The reaction time/nucleation time was found to be the major factor responsible for the modulation of the morphology of the biogenic nanomaterials. The crystalline nature with the cubic crystal system was observed in the case of the silver nanostructure via X-ray diffraction analysis. The antimicrobial efficacy investigated for these nanostructures revealed that the silver nanostructures possess comparable or greater efficacy than the selected control. The excellent efficacy is attributed to the smaller size and the peculiar morphological characteristics of the silver nanostructures. The catalytic reduction of 4-nitrophenol via silver nanostructures was also investigated by using the response surface methodology as an optimization tool. An extremely high percentage reduction value of 96.491 % with the rate constant value of 0.277 min−1 was documented in the case of Ag-NSs. The prepared silver nanostructures were found to be extremely stable till six reuse cycles. Our findings affirm that the efficient synthesis of nanostructures is achieved by using P. emblica fruit extract and the synthesized material further presents excellent viability for antimicrobial and catalytic applications.

The influence of temperature and pressure technological parameters on the characteristics of ZnO nanostructures synthesized by sol-gel process in isopropanol

The sol-gel process was employed to successfully synthesize ZnO nanostructures in isopropanol, employing various subcritical temperature and pressure conditions: (90°C, 2 bar), (120°C, 6 bar), (160°C, 14 bar), and (200°C, 30 bar). The resulting products were subsequently annealed at 500°C for 2 hours and subjected to characterization using different analytical techniques, including X-ray diffraction (DRX), infrared (ATR), UV-Visible, and photoluminescence (PL) spectroscopies. The DRX measurements confirmed that the ZnO nanostructures exhibited a polycrystalline structure of the hexagonal wurtzite type. The cell parameters and stresses within the crystallites were found to be influenced by the synthesis conditions (temperature and pressure), in contrast to the particle size. ATR spectra indicated high purity of the produced nanostructures, and it was observed that the position of the absorption band associated with the Zn-O vibrational bond of ZnO shifted towards lower wavenumbers as the temperature increased. UV-Visible spectra demonstrated that the absorption band shifted towards shorter wavelengths with increasing temperature and pressure. The optical gap displayed a similar trend to the lattice parameters and strain within the nanoparticles. PL measurements revealed that the processing temperature and pressure resulted in increased UV emission and decreased visible emission. However, the positions of the UV emission bands were independent of the synthesis parameters.

Synaptic tauopathy in a model of Alzheimer’s disease and traumatic brain injury

AbstractBackgroundSynapse loss is an early, pathogenic hallmark of Alzheimer’s disease (AD) and related neurodegenerative conditions. We recently demonstrated that traumatic brain injury (TBI) – the best‐established environmental risk factor for AD – also causes synapse loss, thus establishing a potential pathomechanistic connection between these conditions. One likely contributor is the microtubule associated protein tau. Phosphorylated isoforms of tau can be identified in the brain after TBI and are classically associated with AD‐related pathology. The extent to which these pathoisoforms reach synapses and contribute to their loss, however, is minimally explored.MethodWe combined the PS19 mouse model, which exhibits age‐dependent tau aggregation and synapse loss, with early TBI and subsequent aging to investigate tauopathic synaptic alterations in relation to traumatic and AD‐related processes. TBI was induced with a diffuse, closed‐head injury model called modCHIMERA (Sauerbeck et al, 2018) that causes delayed synapse loss. Synaptic analysis was performed with SEQUIN (Sauerbeck et al, 2020, Reitz et al, 2021), a super‐resolution imaging and analysis platform for quantifying synaptic density as well as nanostructure and molecular features in mammalian neuropil.ResultBoth TBI and expression of the P301S mutation resulted in accumulation of pathoisoforms of tau at synapses and regional synapse loss that evolved over time. Temporal and spatial patterns of tau accumulation varied by phosphoisoform. TBI resulted in an additional burden of synapse loss in PS19 animals, suggesting that TBI may increase the risk of AD through a potentiation of synaptic injury. We are exploring the functional consequences of this connection in ongoing experiments.ConclusionThese studies demonstrate novel subcellular targets of pathological tau isoforms and suggest that tau is a key factor in synapse loss in TBI and AD. This shared mechanism may help explain the elevated risk of AD following TBI. Further characterization of these processes may suggest ways to sever this link, as well as prevent synapse loss in primary AD.

Pyridinic and Pyrrolic-N induced carbon nanotubes support bimetallic oxide nanoparticles as high-performance electrocatalysts for oxygen reduction reaction

In-expensive MnO2-based nanostructure has been considered the ideal electrode material for oxygen reduction reaction (ORR) in fuel cell technology. Regardless of their highly active ORR performance, the fuel cross-over capacity and stability of MnO2-based catalysts are still far from satisfying. Herein, we report the highly active SnO2 nanoparticles (NPs) integrated on N-induced carbon nanotube (SnO2@NC) are combined with MnO2 nanoparticles through the electrodeposition to form effective nanostructured in which the MnO2 NPs and SnO2@NC in situ grown on a glassy carbon electrode (MnO2/SnO2@NC) with well-controlled reaction parameters, that exhibits superior ORR activity for the first time. We assessed the marginal role of pyridinic-N and pyrrolic-N in the electrocatalytic ORR activity, synthesis of MnO2/SnO2 bimetallic oxide electrocatalysts, and distribution behavior of NPs. Bimetallic MnO2/SnO2@NC electrode has unique synergistic interactions between MnO2/SnO2 NPs and NC support, which increases electro-active sites, and fast charge transfers towards ORR as compared to other as-prepared electrodes on account of the rational design of the electrode-electrolyte interface plays a significant role in expediting the ORR kinetics. Additionally, the surface nanostructure features, crystalline structure, as well as electronic chemical states of the MnO2/SnO2 NPs embedded in N-induced CNTs, were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Furthermore, bimetallic MnO2/SnO2@NC nanostructure leads an outstanding ORR performance in the 0.1 M KOH electrolyte, delivering a halfwave potential (-0.878 V) and remarkable limiting current density (-4.14 mA cm−2) and much better tolerance to the ethanol cross-over effect with high stability. Thus, the present strategy opens a new path to the design of a pyridinic-N and pyrrolic-N-oriented bimetallic oxide nanostructure as a high-active electrocatalyst for ORR application.

Chitosan-coated magnetic nanorods and nanospheres: physicochemical characterizations and potential as methotrexate carriers for targeted drug delivery

Abstract Spherical magnetite nanoparticles were employed in the almost all magnetic based drug delivery studies. But as we all know the shape of employed particles is one of the major deterministic properties that can significantly affect the physicochemical and biological features of nanostructures and so can fluctuate efficiency of drug delivery. However, it is worthy of consideration that so far no study has investigated the effect of the shape of nanoparticles in drug delivery. To some extent this deficiency in publications may be due to the fact that the synthesis of other forms of magnetite nanoparticles is not as developed as spherical nanoparticles. But recent experiments paved the way for the synthesis of magnetite nanoparticles specially magnetite nanorods (MNRs). So, for the first time, in the current experiment magnetite nanospheres (MNSs) and MNRs were compared in the potential for drug delivery. Chitosan is a natural and biocompatible compound that widely employed as coating material for the fabrication of anticancer drug nano-carriers. So in the present study this carbohydrate was chosen as coating material for the magnetic nanostructures. MNSs were synthesized via a co-precipitation reaction, and MNRs were obtained from the chemical reduction of iron oxide hydroxide (FeOOH) nanorods. Both nanostructures were loaded with methotrexate (MTX), and the release of the drug was measured. The chitosan-coated MNSs (C@MNSs) were 7–18 nm in diameter, and the chitosan-coated MNRs (C@MNRs) were 5–21 nm in width and 29–108 nm in length and had a porous structure. The C@MNSs had a magnetic saturation of ∼80 emu/g, whereas that for the C@MNRs was ∼45 emu/g. The synthesized nanostructures exhibited low toxicity and were able to release the drug inside the cells. The findings of this study demonstrate the suitability of C@MNRs as an alternative to spherical nano-carriers for the efficient and contained delivery of anticancer drugs to designated target cells.

Study on the nano-structure characteristics of particle before and after diesel oxidation catalyst for diesel engines

ABSTRACT Diesel Oxidation Catalyst (DOC) is the most important and advanced part of the after-treatment technology route. After the exhaust passes through DOC, CO, and HC will be significantly reduced, while particles are mainly captured by the Diesel Particulate Filter (DPF) device behind. In order to further investigate the effect of DOC on the nano-structure characteristics of diesel emission particles. The particles before and after DOC of 186FA diesel engine at 2700 r/min, 100% load, and 3600 r/min, 100% load are collected. The nano-structure characteristics of particles are investigated using field emission transmission electron microscopy (FETEM) combined with small angle X-ray scattering radiation technique (SAXS). Based on FETEM and SAXS analysis of particles, a nano-scale particle spatial structure model including particle size, pores, and visual boundary layer is proposed. The results show that the average radius, interface layer thickness, and fractal dimension of the particles are reduced after the DOC. In contrast, the specific surface area of the particles is increased after the DOC. At 3600 r/min 100% load, the average radius is reduced from 23.3 to 21.5 nm, accounting for 7.8%. Interface layer thickness is reduced from 13.3 to 12.9 nm. The specific surface area of the particles is increased from 0.146 to 0.166 m2/mm3. The research results provide a theoretical basis for the regeneration and oxidation of particles in DPF.

Synthesis, phase conversion and physical characteristics of mesoporous β-Ga2O3 nanostructures for catalytic applications

Herein, α-GaOOH micro/nanorods were synthesized by facile template free hydrothermal methods. These rods were converted as mesoporous β-Ga2O3 nanostructures via thermal annealing at 900 °C for 2 h. The structural analysis (XRD) reveals the presence of orthorhombic (α-GaOOH) and monoclinic (β-Ga2O3) phases (pre- and post-annealing). The surface morphology, shape, size and porous structure, growth direction and crystalline quality of the micro/nanorods are investigated using scanning and transmission electron microscopy. Interplanar spacing of 0.37 and 0.46 nm confirms that the growth is along (2 0 1) and (−2 0 1) plane, respectively. The possible growth mechanism was proposed based on the obtained micro-graphical analyses. EDX, elemental mapping and XPS analyses revealed the existence of Ga and O and their chemical states. The characteristic Raman phonon modes confirmed the monoclinic phase of β-Ga2O3. The optical absorbance edge varies between 231 nm (GaOOH) to 290 nm (β-Ga2O3). Subsequently, the band gap varies between 5.6 and 4.4 eV. PL result showed intense ultraviolet and less intense violet-blue emissions, which can be related to the defect level emission. The BET surface area analysis confirmed the mesoporous structure with pore diameter (3.97 nm) and high specific surface area (13.87 m2/g) of Ga-3. The 98 % degradation efficiency with reaction kinetic rates of k = 0.0144/min shows a good catalytic behaviour of Ga-3 catalyst against RhB dye. The results reveal that the hydrothermally grown 1-D β-Ga2O3 mesoporous nanostructures are promising candidates for designing a catalytic and other functional nanodevices.

Role of Plasmonic Antenna in Hot Carrier-Driven Reactions on Bimetallic Nanostructures.

Noble metal nanostructures can efficiently harvest electromagnetic radiation, which, in turn, is used to generate localized surface plasmon resonances. Surface plasmons decay, producing hot carriers, that is, short-lived species that can trigger chemical reactions on metallic surfaces. However, noble metal nanostructures catalyze only a very small number of chemical reactions. This limitation can be overcome by coupling such nanostructures with catalytic-active metals. Although the role of such catalytically active metals in plasmon-driven catalysis is well-understood, the mechanistics of a noble metal antenna in such chemistry remains unclear. In this study, we utilize tip-enhanced Raman spectroscopy, an innovative nanoscale imaging technique, to investigate the rates and yields of plasmon-driven reactions on mono- and bimetallic gold- and silver-based nanostructures. We found that silver nanoplates (AgNPs) demonstrate a significantly higher yield of 4-nitrobenzenehtiol to p,p'-dimercaptoazobisbenzene (DMAB) reduction than gold nanoplates (AuNPs). We also observed substantially greater yields of DMAB on silver-platinum and silver-palladium nanoplates (Ag@PtNPs and Ag@PdNPs) compared to their gold analogues, Au@PtNPs and Au@PdNPs. Furthermore, Ag@PtNPs exhibited enhanced reactivity in 4-mercatophenylmethanol to 4-mercaptobenzoic acid oxidation compared to Au@PtNPs. These results showed that silver-based bimetallic nanostructures feature much greater reactivity compared to their gold-based analogues.

Electron transport in a stressed moiré bigraphene structure

Within the framework of density functional theory in combination with the method of nonequilibrium Green's functions, the transport characteristics (band structure, transmission spectrum, current–voltage characteristic, and differential conductivity) of unstressed, stressed, and strongly stressed moiré bigraphene nanodevices with interlayer distances of 3.4 Å, 2.85 Å, and 1.7 Å, respectively, and consisting of two layers of graphene, where one of the layers is connected to electrodes (active graphene) and the other layer is electrically neutral (passive graphene) have been determined. It is established that, when passive graphene is twisted to certain angles before the moiré pattern is obtained (∼4° and ∼ 12°), the energy gap is opened, the value of range 1.66–1.82 eV and 3.78–4.69 eV in the unstressed state (in the stressed state 2.27–2.67 eV and 4.28–4.93 eV), respectively. It is shown that the transmission spectrum of bilayer graphene has features in the form of peak structures; with decreasing intergraphene distance these structures begin to blur and their quasiperiodic behavior is partially broken. The current–voltage characteristic of such nanostructures has areas with negative differential conductivity. Such nonlinear behavior of transport characteristics of bigraphene moiré structures can be used for the construction of electronic components of nanoelectronics on their basis.

Exploring boron nitride nanostructures for effective pyrazinamide drug delivery: A DFT study

In present investigation, interactions of pyrazinamide molecule with boron nitride nanocones (BNC), boron nitride nanosheet (BNS), and boron nitride nanotube (BNT) as nanostructures have been studied for drug delivery applications via DFT computations. For DFT computations on studied models, two phases (aqueous and gaseous) have been regarded. In both phases, a stabilized complex of nanostructures and pyrazinamide has been obtained based on adsorption energy (Eads) values. According to negative Eads value, an exothermic reaction has been observed. The hydrogen bonding has found in all complexes due to low and positive values of electron density in critical points of bond (ρr) based on the quantum theory of atoms in molecules (QTAIM). Computations outcomes also revealed that there were weak interaction forces for successful and significant unloading of curcumin from carriers in target sites. In order to assess impact of molecular adsorption over electronic features of nanostructures, density of states (DOS) has been analyzed, and outcomes indicated that BNC was more proximate to Fermi energy compared to other nanomaterials. In gaseous phase, Eads values were greater than aqueous phase, which indicates a more robust interaction of molecules with nanostructures. Compared to other nanostructures, curcumin had stronger interaction with BNC based on Eads values. At the end of pyrazinamide adsorption, ΔEg values were – 1.17, − 0.27, and −0.19 eV for BNC, BNS, and BNT, respectively, which reveal that BNC had more sensitivity than BNS and BNT. Based on computations conducted in present work, nanostructures could potentially be employed to deliver pyrazinamide.

Nano-/Microcapsules, Liposomes, and Micelles in Polysaccharide Carriers: Applications in Food Technology

An up-to-date overview of the current state of the art of polysaccharide-based spherical particles as carriers of active/bioactive substances, with a particular emphasis on their applications in the food industry, is provided. Owing to the rapid advances in nanotechnology, much effort has been dedicated to the synthesis and potential uses of these particles. This review outlines recent research on the preparation of spherical nanoparticles, including micro-/nanoencapsulates, micelles, and liposomes, that utilise polysaccharides as carriers and stabilisers. It also discusses the potential application of these nanostructures to the field of food technology. The review aims to provide an objective assessment of the current state of research on this topic. Owing to the distinctive characteristics of spherical nanostructures and the requirement to investigate and scrutinise their potential employment in diverse aspects of the food sector, there are significant opportunities for researchers worldwide to devise innovative solutions.