Search results for "nanoparticle"
showing 10 items of 2198 documents
Spatial variation of soil magnetic susceptibility in relation to different emission sources in southern Poland
2015
Abstract The study in the area surrounding the Rybnik urban agglomeration (southern Poland) was conducted to determine the influence of various emission sources on the occurrence of local magnetic anomalies observed in the forest topsoils. For this reason field measurement of volume-specific magnetic susceptibility (κ) was conducted in forest topsoil on the area of study. The measurements were performed twice: directly on the surface and after removal of forest litter to see the influence of the litter on the magnetic signal measured on the soil surface. The maps of surface distribution of κ value revealed that magnetic anomalies were observed 2.0 km around the residential areas dominated b…
Synthesis and Characterization of Monodisperse Manganese Oxide Nanoparticles−Evaluation of the Nucleation and Growth Mechanism
2009
Magnetic nanoparticles of the 3d transition metal oxides have gained enormous interest for applications in various fields such as data storage devices, catalysis, drug-delivery, and biomedical imaging. One major requirement for these applications is a narrow size distribution of the particles. We have studied the nucleation and growth mechanism for the formation of MnO nanoparticles synthesized by decomposition of a manganese oleate complex in high boiling nonpolar solvents using TEM, FT-IR, and AAS analysis. The exceptionally narrow size distribution indicates that nucleation and growth are clearly separated. This leads to a uniform growth with a very narrow size distribution on the existi…
Recent advances on aptamer-based biosensors to detection of platelet-derived growth factor.
2018
Platelet-derived growth factor (PDGF-BB), a significant serum cytokine, is an important protein biomarker in diagnosis and recognition of cancer, which straightly rolled in proceeding of various cell transformations, including tumor growth and its development. Fibrosis, atherosclerosis are certain appalling diseases, which PDGF-BB is near to them. Generally, the expression amount of PDGF-BB increases in human life-threatening tumors serving as an indicator for tumor angiogenesis. Thus, identification and quantification of PDGF-BB in biomedical fields are particularly important. Affinity chromatography, immunohistochemical methods and enzyme-linked immunosorbent assay (ELISA), conventional m…
Not just for tumor targeting: unmet medical needs and opportunities for nanomedicine.
2015
During the last 3 decades, nanomedicines have provided novel opportunities to improve the delivery of chemotherapeutics in cancer therapy effectively. However, many principles learnt from there have the potential to be transferred to other diseases. This perspective article, on the one hand, critically reflects the limitations of nanomedicines in tumor therapy and, on the other hand, provides alternative examples of nanomedicinal applications in immunotherapy, noninvasive drug deliveries across epithelial barriers and strategies to combat intra- and extra-cellular bacterial infections. Looking ahead, access to highly complex nanoparticular delivery vehicles given nowadays may allow further…
Surface Defects as a Tool to Solubilize and Functionalize WS 2 Nanotubes
2017
Layered transition metal dichalcogenides contain a number of crystal defects which significantly change their properties may be beneficial or detrimental for a specific application. We have prepared defect-rich multiwalled WS2 nanotubes by reductive sulfidization of W18O49 nanowires that were obtained solvothermally from tungsten chloride in different alcohols. The synthesis of the W18O49 nanowires was monitored and their morphological characteristics (e. g. length, rigidity and aspect ratio) are described in detail. The effect of morphology of the nanowires on the synthesis of WS2 nanotubes was investigated in order to obtain WS2 nanotubes that are highly solvent dispersible. Dispersions o…
Magnetic nanoparticles between electrodes of tunnel junction: anomalous tunnel conductance
2002
Abstract Magnetic particles of microscopic size can be created in the process of Ni, Fe and Co mechanically controllable break junctions fabrication and trapped between the electrodes by magnetic dipole forces. Tunneling between the protruding nanoparticle and the sample electrode shows clear distinctions from the usual junctions: heavy deviation of the current–distance I(z) dependence from the expected exponential behavior at electrode separations z below 4.0– 4.5 A and on numerous occasions a sudden jump-like decrease of the tunnel current at z≈1.5– 2.0 A . Possible mechanisms behind observed anomalies including the short-range magnetic exchange coupling are discussed.
Comparative toxicity and cell-tissue distribution study on nanoparticular iron complexes using avian embryos and HepG2-cells
2007
In this study the toxicity and intracellular availability of iron from iron dextran (FeD), iron sucrose (FeS), and iron gluconate (FeG) was compared in organs of avian (turkey) embryos and in isolated cells (HepG2) in cell culture. Iron uptake was more pronounced in embryonic liver than in renal tissue. Cellular iron uptake in liver and kidney was more or less similar for the different compounds. Only some experiments showed slightly greater iron concentrations in liver and kidney with FeG compared with FeD and FeS. Significant differences were found in the survival ratios of the eggs and the embryo weights depending on the type of iron complex administered. The rank order of toxicities was…
Thermo-oxidative resistant UHMWPE-based nanocomposites containing hybrid-nanoparticles based on natural anti-oxidants and carbon nanotubes
2015
The use of natural antioxidants is an attractive way to formulate nanocomposites with extended durability and with potential applications in bio-medical field. In this work, Vitamin E (VE) in the form of α-tocopherol and Quercetin (Q) were physically immobilized onto multi-walled carbon nanotubes bearing covalently-linked long-chain alkyl ester groups (CNTs) and the resulting hybrids CNTs-VE and CNTs-Q were used to formulate thermo-oxidation stable ultra high molecular weight polyethylene based nanocomposites. The thermo-oxidation of the nanocomposites was performed at 120°C in air oven. The samples were then subjected to FTIR analyses at different annealing times. The accurate analysis of …
Coupling colloidal chemistry with coordination chemistry: Design of hybrid nanomaterials by the assembly of plasmonic nanoparticles and functional co…
2021
Nanotechnology involves the design, characterization, production and application of structures, devices and systems by the control of the shape and size at the nanometer scale involving different fields. In the last decade, nanotechnology development has boosted the interest in hybrid nanomaterials. These materials are a complimenting combination of two (or more) nanoparticles (NPs) with enhanced performance characteristics that offer exciting opportunities. It allows the possibility of integrating materials with different physical and chemical properties to widen the range of practical applications. In this context, Au NPs have recently attracted a lot of attention due to the great opportu…
Stimuli-responsive magnetic coordination polymers: from crystals to nanoparticles
2013
El trabajo descrito en esta tesis se enmarca en el ámbito de los polímeros de coordinación (PC). Estos sistemas representan un área importante dentro de la Química de los Materiales, siendo principalmente interesantes sus aplicaciones en catálisis, electrónica y óptica. Su origen data de principios de los años 60, donde se produjo la primera revisión de estructuras de compuestos inorgánicos que formaban cadenas.1 Los PC están formados por ligandos orgánicos y metales enlazados por enlaces de coordinación que se extienden infinitamente en 1, 2 o 3 dimensiones. En cuanto a su versatilidad química, las estructuras y propiedades varían en función de los metales o ligandos utilizados. Así pues, …