139 research outputs found
Blood clearance and tissue distribution of PEGylated and non-PEGylated gold nanorods after intravenous administration in rats\ud
Aims: To develop and determine the safety of gold nanorods, whose aspect ratios can be tuned to obtain plasmon peaks between 650 and 850 nm, as contrast enhancing agents for diagnostic and therapeutic applications. Materials & methods: In this study we compared the blood clearance and tissue distribution of cetyl trimethyl ammonium bromide (CTAB)-capped and polyethylene glycol (PEG)-coated gold nanorods after intravenous injection in the tail vein of rats. The gold content in blood and various organs was measured quantitatively with inductively coupled plasma mass spectrometry. Results & discussion: The CTAB-capped gold nanorods were almost immediately (<15 min) cleared from the blood circulation whereas the PEGylation of gold nanorods resulted in a prolonged blood circulation with a half-life time of 19 h and more wide spread tissue distribution. While for the CTAB-capped gold nanorods the tissue distribution was limited to liver, spleen and lung, the PEGylated gold nanorods also distributed to kidney, heart, thymus, brain and testes. PEGylation of the gold nanorods resulted in the spleen being the organ with the highest exposure, whereas for the non-PEGylated CTAB-capped gold nanorods the liver was the organ with the highest exposure, per gram of organ. Conclusion: The PEGylation of gold nanorods resulted in a prolongation of the blood clearance and the highest organ exposure in the spleen. In view of the time frame (up to 48 h) of the observed presence in blood circulation, PEGylated gold nanorods can be considered to be promising candidates for therapeutic and diagnostic imaging purpose
Semigroups of distributions with linear Jacobi parameters
We show that a convolution semigroup of measures has Jacobi parameters
polynomial in the convolution parameter if and only if the measures come
from the Meixner class. Moreover, we prove the parallel result, in a more
explicit way, for the free convolution and the free Meixner class. We then
construct the class of measures satisfying the same property for the two-state
free convolution. This class of two-state free convolution semigroups has not
been considered explicitly before. We show that it also has Meixner-type
properties. Specifically, it contains the analogs of the normal, Poisson, and
binomial distributions, has a Laha-Lukacs-type characterization, and is related
to the case of quadratic harnesses.Comment: v3: the article is merged back together with arXiv:1003.4025. A
significant revision following suggestions by the referee. 2 pdf figure
Enabling FAIR research in Earth Science through research objects
Data-intensive science communities are progressively adopting FAIR practices that enhance the
visibility of scientific breakthroughs and enable reuse. At the core of this movement, research objects
contain and describe scientific information and resources in a way compliant with the FAIR principles
and sustain the development of key infrastructure and tools. This paper provides an account of
the challenges, experiences and solutions involved in the adoption of FAIR around research objects
over several Earth Science disciplines. During this journey, our work has been comprehensive, with
outcomes including: an extended research object model adapted to the needs of earth scientists;
the provisioning of digital object identifiers (DOI) to enable persistent identification and to give due
credit to authors; the generation of content-based, semantically rich, research object metadata through natural language processing, enhancing visibility and reuse through recommendation systems and
third-party search engines; and various types of checklists that provide a compact representation of
research object quality as a key enabler of scientific reuse. All these results have been integrated in
ROHub, a platform that provides research object management functionality to a wealth of applications
and interfaces across different scientific communities. To monitor and quantify the community uptake
of research objects, we have defined indicators and obtained measures via ROHub that are also
discussed herein.Published550-5645IT. Osservazioni satellitariJCR Journa
Радиографический метод контроля сварных швов трубопроводов
Обнаружение дефектов сварных соединений является одной из основных задач неразрушающего контроля, применяемого для диагностики технического состояния трубопроводов различного назначения. Среди методов неразрушающего контроля широкое распространение получил радиографический метод. Для обработки изображений, полученных радиографическим методом, и обнаружения дефектов сварки, используются различные алгоритмы. Одним из перспективных алгоритмов обработки изображений является алгоритм, основанный на методе нейронной сети.Detection of defects in welded joints is one of the main tasks of non-destructive testing used for diagnostics of the technical condition of pipelines for various purposes. Among the methods of nondestructive testing, the radiographic method is widely used. For processing images obtained by radiographic method, and the detection of welding defects, various algorithms are used. One of the promising algorithms for image processing is an algorithm based on the neural network method
Exploring the effect of silver nanoparticle size and medium composition on uptake into pulmonary epithelial 16HBE14o-cells
Quantification of silver nanoparticle uptake and distribution within individual human macrophages by FIB/SEM slice and view
Background
Quantification of nanoparticle (NP) uptake in cells or tissues is very important for safety assessment. Often, electron microscopy based approaches are used for this purpose, which allow imaging at very high resolution. However, precise quantification of NP numbers in cells and tissues remains challenging. The aim of this study was to present a novel approach, that combines precise quantification of NPs in individual cells together with high resolution imaging of their intracellular distribution based on focused ion beam/ scanning electron microscopy (FIB/SEM) slice and view approaches.
Results
We quantified cellular uptake of 75 nm diameter citrate stabilized silver NPs (Ag 75 Cit) into an individual human macrophage derived from monocytic THP-1 cells using a FIB/SEM slice and view approach. Cells were treated with 10 μg/ml for 24 h. We investigated a single cell and found in total 3138 ± 722 silver NPs inside this cell. Most of the silver NPs were located in large agglomerates, only a few were found in clusters of fewer than five NPs. Furthermore, we cross-checked our results by using inductively coupled plasma mass spectrometry and could confirm the FIB/SEM results.
Conclusions
Our approach based on FIB/SEM slice and view is currently the only one that allows the quantification of the absolute dose of silver NPs in individual cells and at the same time to assess their intracellular distribution at high resolution. We therefore propose to use FIB/SEM slice and view to systematically analyse the cellular uptake of various NPs as a function of size, concentration and incubation time.TU Berlin, Open-Access-Mittel - 201
Predictions of Binding of a Diverse Set of Ligands to Gelatinase-A by a Combination of Molecular Dynamics and Continuum Solvent Models
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