160 research outputs found
Deposition of fluorescent NIPAM-based nanoparticles on solid surfaces: quantitative analysis and the factors affecting it
Recently, responsive surfaces have attracted attention due to their potential applications. Reported research have studied the deposition of environmentally responsive particles on different surfaces, qualitatively tested their response to environmental conditions and studied their possible applications. In this work, novel fluorescent temperature-sensitive nanoparticles were synthesized using a surfactant free emulsion polymerization technique: poly(N-isopropylacrylamide-co-5% vinyl cinnamate) (p(NIPAM)5%VC). The new particles were characterized using dynamic light scattering and fluorescence spectroscopy. A novel sensitive method for the quantitative analysis of p(NIPAM) 5% VC using fluorescence spectroscopy was developed to determine the concentration of nanoparticle dispersions. This was further used to quantitatively determine the mass of nanoparticles deposited per unit area of glass pre-treated with acid, glass pre-treated with base, quartz, stainless steel, gold and teflon at 25 °C and 60 °C. Factors affecting the adsorption/desorption of the nanoparticles were studied, including the effect of substrate surface charge, surface roughness (using atomic force microscopy, AFM), hydrophilicity/hydrophobicity and the temperature at which the adsorption/desorption experiments were carried out. The results show that the effect of surface charge is the most significant, followed by that of surface roughness and temperature. Meanwhile, the influence of the hydrophobicity/hydrophilicity of the surface on the adsorption/desorption of nanoparticles appears to be far less significant than the previously mentioned factors
A comparative study of non-covalent encapsulation methods for organic dyes into silica nanoparticles
Numerous luminophores may be encapsulated into silica nanoparticles (< 100 nm) using the reverse microemulsion process. Nevertheless, the behaviour and effect of such luminescent molecules appear to have been much less studied and may possibly prevent the encapsulation process from occurring. Such nanospheres represent attractive nanoplatforms for the development of biotargeted biocompatible luminescent tracers. Physical and chemical properties of the encapsulated molecules may be affected by the nanomatrix. This study examines the synthesis of different types of dispersed silica nanoparticles, the ability of the selected luminophores towards incorporation into the silica matrix of those nanoobjects as well as the photophysical properties of the produced dye-doped silica nanoparticles. The nanoparticles present mean diameters between 40 and 60 nm as shown by TEM analysis. Mainly, the photophysical characteristics of the dyes are retained upon their encapsulation into the silica matrix, leading to fluorescent silica nanoparticles. This feature article surveys recent research progress on the fabrication strategies of these dye-doped silica nanoparticles
Cardiopulmonary assessment of patients with systemic sclerosis for hematopoietic stem cell transplantation: recommendations from the European Society for Blood and Marrow Transplantation Autoimmune Diseases Working Party and collaborating partners.
Systemic sclerosis (SSc) is a rare disabling autoimmune disease with a similar mortality to many cancers. Two randomized controlled trials of autologous hematopoietic stem cell transplantation (AHSCT) for SSc have shown significant improvement in organ function, quality of life and long-term survival compared to standard therapy. However, transplant-related mortality (TRM) ranged from 3-10% in patients undergoing HSCT. In SSc, the main cause of non-transplant and TRM is cardiac related. We therefore updated the previously published guidelines for cardiac evaluation, which should be performed in dedicated centers with expertize in HSCT for SSc. The current recommendations are based on pre-transplant cardiopulmonary evaluations combining pulmonary function tests, echocardiography, cardiac magnetic resonance imaging and invasive hemodynamic testing, initiated at Northwestern University (Chicago) and subsequently discussed and endorsed within the EBMT ADWP in 2016
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