Search results for "Tube"

Atypical Human Effector/Memory CD4(+) T Cells With a Naive-Like Phenotype

2018

The induction of adaptive immunological memory, mediated by T and B cells, plays an important role in protective immunity to pathogens induced by previous infections or vaccination. Naive CD4+ T cells that have been primed by antigen develop into memory or effector cells, which may be distinguished by their capability to exert a long-term and rapid response upon re-challenge by antigen, to produce distinct cytokines and surface marker expression phenotypes such as CD45RA/RO, CD27, CD62L, and CCR7. Moreover, a distinct lineage of memory T cells populates tissues (tissue-resident memory T cells or TRM cells) which orchestratea the response to pathogens re encountered at tissue sites. Recent e…

Stress Transfer within CNT Fibres: A FEA Approach

2015

Abstract Carbon nanotube (CNT) fibres are characterized by extreme anisotropy in their structure and physical properties. These fibres have been shown to have high axial strength, but poor shear strength between carbon nanotubes; for this reason it is difficult to transfer stress uniformly acrossthe fibre cross section. Here, Finite Element Analysis (FEA) is used to predict the stress distribution and the stress-strain curves of CNT fibres. The resultsdemonstrate that, in accordance with St. Venant principle,very considerable length-to-diameter ratios (> 10 3 ) are required to obtain a uniform stress distribution within the fibres even in the presence of low applied strain.

Drug Susceptibility Patterns in MDR-TB Patients: Challenges for Future Regimen Design. A Cross-Sectional Study

2015

Globally, there is substantial concern regarding the challenges of treating complex drug resistance patterns in multidrug resistant tuberculosis cases. Utilising data from three different settings (Estonia, Latvia, Romania) we sought to contrast drug susceptibility profiles for multidrug resistant tuberculosis cases, highlight the difficulties in designing universal regimen, and inform future regimen selection. Demographic and microbiological surveillance data for multidrug resistant tuberculosis cases from 2004-13 were analysed. High levels of additional resistance to currently recommended second line drugs were seen in all settings, with extensive variability between countries. Accurate d…

Amplified morphogenetic and bone forming activity of amorphous versus crystalline calcium phosphate/polyphosphate.

2020

Amorphous Ca-phosphate (ACP) particles stabilized by inorganic polyphosphate (polyP) were prepared by co-precipitation of calcium and phosphate in the presence of polyP (15% [w/w]). These hybrid nanoparticles showed no signs of crystallinity according to X-ray diffraction analysis, in contrast to the particles obtained at a lower (5% [w/w]) polyP concentration or to hydroxyapatite. The ACP/15% polyP particles proved to be a suitable matrix for cell growth and attachment and showed pronounced osteoblastic and vasculogenic activity in vitro. They strongly stimulated mineralization of the human osteosarcoma cell line SaOS-2, as well as cell migration/microvascularization, as demonstrated in th…

Osteosarcoma cell-derived exosomes affect tumor microenvironment by specific packaging of microRNAs

2018

Abstract Bone microenvironment provides growth and survival signals essential for osteosarcoma (OS) initiation and progression. OS cells regulate communications inside tumor microenvironment through different ways and, among all, tumor-derived exosomes support cancer progression and metastasis. To define the contribution of OS-derived exosomes inside the microenvironment, we investigated the effects induced in bone remodeling mechanism and tumor angiogenesis. We demonstrated that exosomes promoted osteoclasts differentiation and bone resorption activity. Furthermore, exosomes potentiated tube formation of endothelial cells and increased angiogenic markers expression. We therefore investigat…

Tracheal development and the von Hippel-Lindau tumor suppressor homolog in Drosophila.

2000

von Hippel-Lindau disease is a hereditary cancer syndrome. Mutations in the VHL tumor suppressor gene predispose individuals to highly vascularized tumors. However, VHL-deficient mice die in utero due to a lack of vascularization in the placenta. To resolve the contradiction, we cloned the Drosophila VHL homologue (d-VHL) and studied its function. It showed an overall 50% similarity to the human counterpart and 76% similarity in the crucial functional domain: the elongin C binding site. The putative d-VHL protein can bind Drosophila elongin C in vitro. During embryogenesis, d-VHL is expressed in the developing tracheal regions where tube outgrowth no longer occurs. Reduced d-VHL activity (u…

Carbon Nanotube-Reinforced Nanocomposites.

CONTROLLING THE FUNCTIONALIZATION OF CARBON NANOTUBES AND GRAPHENE NANOPLATELETS

2013

The functionalization of carbon nanostructures by diazonium chemistry is a versatile strategy to obtain soluble nanomaterials with degrees of functionalization among the highest ever reported.[1,2] Starting from these premises we have studied the functionalization of single, double and multi-walled carbon nanotubes and graphene nanoplatelets by addition of aryl diazonium salts generated in situ by treatment of 4-substituted anilines with isopentylnitrite. Taking advantage of highly controlled flow synthesis [3-5] and following a thorough purification and characterization protocol (UV-vis, TGA, ATR-IR, AFM and other surface tools), we have investigated the key parameters to obtain both funct…

Carbon based nanomaterials for the detection of narrow therapeutic index pharmaceuticals

2020

Precise detection of important pharmaceuticals with narrow therapeutic index (NTI) is very critical as there is a small window between their effective dose and the doses at which the adverse reactions are very likely to appear. Regarding the fact that various pharmacokinetics will be plausible while considering pharmacogenetic factors and also differences between generic and brand name drugs, accurate detection of NTI will be more important. Current routine analytical techniques suffer from many drawbacks while using novel biosensors can bring up many advantages including fast detection, accuracy, low cost with simple and repeatable measurements. Recently the well-known carbon Nano-allotrop…

Carbon Nanostructures: Covalent and Macromolecular Chemistry

2012

The aim of this introductory chapter is to bring to the attention of the readers the achievements made in the chemistry of carbon nanostructures and, mostly, in the chemistry of fullerenes, carbon nanotubes (CNTs), and the most recent graphenes. Since the discovery of fullerenes in 1985 and their further preparation in multigram amounts, the chemistry and reactivity of thesemolecular carbon allotropes have been well established. Actually, this chemical reactivity has been used as a benchmark for further studies carried out in the coming carbon nanotubes (single andmultiple wall) and graphenes. Assuming that the fundamental chemistry of fullerenes is known and basically corresponds to that o…