Increase In Number Of Areas Research Articles

Intracellular Quantification and Localization of Label-Free Iron Oxide Nanoparticles by Holotomographic Microscopy.

BackgroundThe limitations of optical microscopy to determine the cellular localization of label-free nanoparticles prevent a solid prediction of the cellular effect of particles intended for medical applications. To avoid the strong physicochemical changes associated with fluorescent labelling, which often result in differences in cellular uptake, efficiency and toxicity of particles, novel detection techniques are required.MethodsIn the present study, we determined the intracellular content of unlabeled SPIONs by analyzing refractive index (RI)-based images from holotomographic three-dimensional (3D) microscopy and side scatter data measured by flow cytometry. The results were compared with the actual cellular SPION amount as quantified by atomic emission spectroscopy (AES).ResultsLive cell imaging by 3D holotomographic microscopy demonstrated cell-specific differences in intracellular nanoparticle uptake in different pancreatic cell lines. Thus, treatment of PANC-1SMAD4 (1−4) and PANC-1SMAD4 (2−6) with SPIONs resulted in a significant increase in number of areas with higher RI, whereas in PANC-1, SUIT-2 and PaCa DD183, only a minimal increase of spots with high RI was observed. The increase in areas with high RI was in accordance with the SPION content determined by quantitative iron measurements using AES. In contrast, determination of the SPION amount by flow cytometry was strongly cell type-dependent and did not allow the discrimination between intracellular and membrane-bound SPIONs. However, flow cytometry is a very rapid and reliable method to assess the cellular toxicity and allows an estimation of the cell-associated SPION content.ConclusionHolotomographic 3D microscopy is a useful method to distinguish between intracellular and membrane-associated particles. Thus, it provides a valuable tool for scientists to evaluate the cellular localization and the particle load, which facilitates prediction of potential toxicity and efficiency of nanoparticles for medical applications.

Analysing Socio-Economic Change Using a Time Comparable Geodemographic Classification: England and Wales, 1991–2011

Geodemographic classifications are used to understand social phenomena. Within the private sector, for business planning accounting for underlying spatial differences in economic, social and demographic composition of geographical areas. In the public sector geodemographics is used in health, local governance and social research. Bespoke geodemographic systems help public health authorities to target neighbourhoods most at need of health campaigns. Geodemographic classifications are invariably cross-sectional and static. Having comparable geodemographic classifications over a period of time will help demonstrate changes in socio-economic and demographic structures. A time-comparable geodemographic scheme can bring out changes in multivariable compositional characteristics which are otherwise hidden by cross-sectional measures. This paper reports on variable selection, the conversion of inputs to a consistent geography and the creation of directly comparable geodemographic classifications of small areas across England and Wales for 1991, 2001 and 2011. Changes and stability in area characteristics are then analysed. The results show that most neighbourhoods are allocated into the same area type over time. Where there is change, this can be themed as: Socio-economic polarisation, characterised by a decrease in neighbourhoods found in the middle of the socio-economic spectrum, with an increase in number of areas at either end; Growth in the number of neighbourhoods with non-White ethnic residents, mainly Black ethnic minorities and Asian based communities and; Reorganisation and increase in classifications relating to urban areas, signalling development or growth of metropolitan areas.