68 research outputs found
Press reslease from the Premier and Tourism Minister, Mr Dunstan: New amenity block for Moonta Bay Caravan Park
Getting rid of the tubes: An assessment of the retention of functionalized multi-walled carbon nanotubes (MWNTs) in the organs of mice was carried out using single photon emission computed tomography and quantitative scintigraphy (see scheme). Increasing the degree of functionalization on MWNTs enhanced renal clearance, while lower functionalization promoted reticuloendethelial system accumulation
Benign chondroid syringoma of the orbit: a rare cause of exophtalmos
Chondroid syringoma (CS) of the orbit is an extremely rare benign neoplasm. To the best of our knowledege, this is the second case reported in the english litérature
Cationic Liposome- Multi-Walled Carbon Nanotubes Hybrids for Dual siPLK1 and Doxorubicin Delivery In Vitro
Time-Dependent Subcellular Distribution and Effects of Carbon Nanotubes in Lungs of Mice
BACKGROUND AND METHODS:Pulmonary deposited carbon nanotubes (CNTs) are cleared very slowly from the lung, but there is limited information on how CNTs interact with the lung tissue over time. To address this, three different multiwalled CNTs were intratracheally instilled into female C57BL/6 mice: one short (850 nm) and tangled, and two longer (4 ÎŒm and 5.7 ÎŒm) and thicker. We assessed the cellular interaction with these CNTs using transmission electron microscopy (TEM) 1, 3 and 28 days after instillation. RESULTS:TEM analysis revealed that the three CNTs followed the same overall progression pattern over time. Initially, CNTs were taken up either by a diffusion mechanism or via endocytosis. Then CNTs were agglomerated in vesicles in macrophages. Lastly, at 28 days post-exposure, evidence suggesting CNT escape from vesicle enclosures were found. The longer and thicker CNTs more often perturbed and escaped vesicular enclosures in macrophages compared to the smaller CNTs. Bronchoalveolar lavage (BAL) showed that the CNT exposure induced both an eosinophil influx and also eosinophilic crystalline pneumonia. CONCLUSION:Two very different types of multiwalled CNTs had very similar pattern of cellular interactions in lung tissue, with the longer and thicker CNTs resulting in more severe effects in terms of eosinophil influx and incidence of eosinophilic crystalline pneumonia (ECP)
Carbon Nanotubes in Tissue Engineering
For their peculiar features carbon nanotubes (CNTs) are emerging in many areas of nanotechnology applications. CNT-based technology has been increasingly proposed for biomedical applications, to develop biomolecule nanocarriers, bionanosensors and smart material for tissue engineering purposes. In the following chapter this latter application will be explored, describing why CNTs can be considered an ideal material able to support and boost the growth and the proliferation of many kind of tissues
Carbon nanotubes' surface chemistry determines their potency as vaccine nanocarriers in vitro and in vivo
Carbon nanotubes (CNTs) have shown marked capabilities in enhancing antigen delivery to antigen presenting
cells. However, proper understanding of how altering the physical properties of CNTs may influence antigen uptake
by antigen presenting cells, such as dendritic cells (DCs), has not been established yet.Wehypothesized that
altering the physical properties of multi-walled CNTs (MWNTs)-antigen conjugates, e.g. length and surface
charge, can affect the internalization of MWNT-antigen by DCs, hence the induced immune response potency.
For this purpose, pristineMWNTs (p-MWNTs) were exposed to various chemical reactions to modify their physical
properties then conjugated to ovalbumin (OVA), a model antigen. The yieldedMWNTs-OVA conjugateswere
longMWNT-OVA (~386 nm), bearing net positive charge (5.8mV), or shortMWNTs-OVA (~122 nm) of increasing
negative charges (â23.4, â35.8 or â39 mV). Compared to the short MWNTs-OVA bearing high negative
charges, short MWNT-OVA with the lowest negative charge demonstrated better cellular uptake and OVAspecific
immune response both in vitro and in vivo. However, long positively-chargedMWNT-OVA showed limited
cellular uptake and OVA specific immune response in contrast to shortMWNT-OVA displaying the least negative
charge. We suggest that reduction in charge negativity of MWNT-antigen conjugate enhances cellular
uptake and thus the elicited immune response intensity. Nevertheless, length of MWNT-antigen conjugate
might also affect the cellular uptake and immune response potency; highlighting the importance of physical
properties as a consideration in designing a MWNT-based vaccine delivery system
CaractĂ©risation dâun bĂ©ton autoplaçant avec addition de laitier cristallisĂ© et renforcĂ© par des fibres de polypropylĂšne et de diss
Le renforcement du bĂ©ton par les fibres mĂ©talliques, synthĂ©tiques ou un systĂšme hybride, est une dĂ©marche classique. Cependant pour le bĂ©ton autoplaçant (BAP), lâutilisation de fibres peut affecter la capacitĂ©Â dâĂ©coulement du matĂ©riau en particulier lorsquâil sâagit de fibres vĂ©gĂ©tales, on peut s'attendre Ă une perte d'ouvrabilitĂ©. En effet, les fibres vĂ©gĂ©tales se caractĂ©risent par un pouvoir dâabsorption dâeau important et leur contour n'est pas lisse comme celui des fibres de polypropylĂšne, il prĂ©sente gĂ©nĂ©ralement des aspĂ©ritĂ©s et une rugositĂ©. Cet Ă©tat de surface a des effets contradictoires : il entraĂźne une lĂ©gĂšre diminution de la fluiditĂ© du bĂ©ton dâune part et amĂ©liore lâancrage de la fibre dans la matrice cimentaire d'autre part. Dans cette Ă©tude, deux types de fibres ont Ă©tĂ© utilisĂ©s : une fibre de polypropylĂšne comme matĂ©riau de rĂ©fĂ©rence et une fibre naturelle (fibre de diss) comme matĂ©riau dâĂ©tude. Notre travail a consistĂ© Ă mettre en Ă©vidence les effets de ces fibres sur le comportement Ă lâĂ©tat frais (Ă©talement, taux de remplissage et stabilitĂ© au tamis) et le comportement Ă lâĂ©tat durci (essai de traction par flexion, de compression et de retrait empĂȘchĂ©) des BAP. Les rĂ©sultats obtenus montrent que les fibres affectent les caractĂ©ristiques des BAP Ă lâĂ©tat frais, notamment lâĂ©coulement mais permettent dâamĂ©liorer sa rĂ©sistance en traction par flexion. Les fibres de diss retardent aussi la fissuration des bĂ©tons.Mots clĂ©s: BĂ©tons autoplaçants - Fibre vĂ©gĂ©tale - Fibre de polypropylĂšne â Additions - Ecoulement.Characterization of a self-compacting concrete with addition of crystallized slag and reinforced with polypropylene and diss fibersConcrete reinforcement by steel fibers, a synthetic or hybrid fiber is usual. However, for self compacting concrete (SSC) the fiber-reinforcement can decrease the workability. This is particularly true for polypropylene or vegetable fibers for which a significant loss of workability is expected due to the roughness of their surface. Such a surface state has contradictory effects on the material properties: on one hand, it reduces the flow of fresh concrete and on the other hand, it improves the bond between the fibers and the hardened cement matrix. In this paper, two types of fibers were used: natural fibers (Diss fibers) and polypropylene fibers. The contribution focuses on studying the effects of these fibers on both the fresh hard SCC properties and hardened ones (flexural, compression test and restrained shrinkage). Results show a decrease of the fresh SSC characteristics including the flow and an increase of the flexural strength of the hardened SSC reinforced by fibers vegetable fibers also delay cracking of concrete.Keywords: Self compacting concrete - Plant fiber - Polypropylene fiber- Additions- Flo
Multi-walled carbon nanotube-doxorubicin supramolecular complexes for cancer therapeutics
The potential of carbon nanotubes as carriers and delivery vectors for anticancer drugs was investigated. Herein, we propose MWNT-doxorubicin supramolecular complexes that can be developed for cancer therapy. The formation of such complexes is evidenced by a sharp decrease in the intensity of the doxorubicin fluorescence spectrum and takes place via Ï-Ï interactions with the MWNT backbone. In addition, the structural characteristics of the CNT-doxorubicin complexes were examined by transmission electron microscopy and showed well dispersed pluronic wrapped MWNT but clustered MWNT-doxorubicin structures. Very interestingly the doxorubicinMWNT complexes exhibit enhanced cytotoxic activity compared to both doxorubicin alone and doxorubicin-pluronic complexes.</p
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