Diffusion barrier properties of the perineurium: an in vivo ionic lanthanum tracer study

1989 ◽  
Vol 180 (3) ◽  
pp. 237-242 ◽  
Author(s):  
M. N. Ghabriel ◽  
K. H. Jennings ◽  
G. Allt
Keyword(s):  
Diffusion Barrier ◽  
Barrier Properties ◽  
Tracer Study ◽  
Ionic Lanthanum ◽  
Lanthanum Tracer

Ultrastructure of melanocyte-keratinocyte interactions and pigment transfer in vitro

1978 ◽  
Vol 36 (2) ◽  
pp. 650-651
Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo
Keyword(s):  
Direct Injection ◽  
Skin Pigmentation ◽  
Freeze Fracture ◽  
Pigment Granule ◽  
Time Lapse ◽  
Ultrastructural Level ◽  
Lanthanum Tracer ◽  
A Cell

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.

Adhesion and Cu Diffusion Barrier Properties of a MnOx Barrier Layer Formed with Thermal MOCVD

2009 ◽  
Vol 1156 ◽  
Author(s):  
Koji Neishi ◽  
Vijay Kumar Dixit ◽  
S. Aki ◽  
Junichi Koike ◽  
K. Matsumoto ◽  
...  
Keyword(s):  
Barrier Layer ◽  
Diffusion Barrier ◽  
Valence State ◽  
Dielectric Layer ◽  
Barrier Properties ◽  
Barrier Property ◽  
Adhesion Property ◽  
Composition Analysis ◽  
Good Adhesion ◽  
Deposition Chamber

AbstractA thin-amorphous MnOx layer using self-forming barrier process with a Cu-Mn alloy shows good adhesion and diffusion barrier properties between copper and dielectric layer, resulting in excellent reliability for stress and electromigration. Meanwhile, chemical vapor deposition (CVD) can be employed for conformal deposition of the barrier layer in narrow trenches and vias for future technology node. In our previous research, a thin and uniform amorphous MnOx layer could be formed on TEOS-oxide by thermal metal-organic CVD (MOCVD), showing a good diffusion barrier property. In addition, a good adhesion strength is necessary between a Cu line and a dielectric layer not only to ensure good SM and EM resistance but also to prevent film delamination under mechanical or thermal stress conditions during fabrication process such as chemical mechanical polishing or high temperature annealing. To date, no information is available with regard to the adhesion property of CVD-MnOx. In this work, we report diffusion barrier property in further detail and adhesion property in PVD-Cu/CVD-MnOx/SiO2/Si. The temperature dependence of the adhesion property is correlated with the chemical composition and valence state of Mn investigated with SIMS and Raman spectroscopy.Substrates were p-type Si wafers having a plasma-TEOS oxide of 100nm in thickness. CVD was carried out in a deposition chamber. A manganese precursor was vaporized and introduced into the deposition chamber with H2 carrier gas. After the CVD, a Cu overlayer was deposited on some samples using a sputtering system in load lock chamber of the CVD machine. The diffusion barrier property of the MnOx film was investigated in annealed samples at 400 oC for 100 hours in a vacuum of better than 1.0×10-5 Pa. The Adhesion property of Mn oxide was investigated by Scotch tape test in the as-deposited and in the annealed Cu/CVD-MnOx/TEOS samples. The obtained samples were analyzed for thickness and microstructure with TEM, chemical bonding states of the MnOx layer with XPS, and composition of each layer with SIMS.In the CVD deposition below 300 °C, no Cu delamination was observed both in the as-deposited and in the annealed Cu/CVD-MnOx/SiO2 samples. On the other hand, in the CVD deposition at 400 °C, the Cu films were delaminated from the CVD-MnOx/TEOS substrates. The XPS peak position of Mn 2p and Mn 3s spectra indicated that the valence state of Mn in the as-deposited barrier layer below 400 °C was 2+. Composition analysis with SIMS as well as Raman also indicated the presence of a larger amount of carbon at 400 °C than at less than 300 °C. The good adhesion between Cu and MnO could be attributed to an amount of carbon inclusion in the CVD barrier layer.

scholarly journals Diffusion barrier properties of molybdenum back contacts for Cu(In,Ga)Se2solar cells on stainless steel foils

2013 ◽  
Vol 113 (5) ◽  
pp. 054506 ◽  
Author(s):  
P. Blösch ◽  
F. Pianezzi ◽  
A. Chirilă ◽  
P. Rossbach ◽  
S. Nishiwaki ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Diffusion Barrier ◽  
Barrier Properties ◽  
Stainless Steel Foils ◽  
Steel Foils

Insect peripheral nerves: accessibility of neurohaemal regions to lanthanum

1975 ◽  
Vol 18 (1) ◽  
pp. 179-197 ◽  
Author(s):  
N.J. Lane ◽  
R.A. Leslie ◽  
L.S. Swales
Keyword(s):  
Blood Brain Barrier ◽  
Peripheral Nerves ◽  
Rhodnius Prolixus ◽  
Ionic Lanthanum ◽  
Neurosecretory Axon ◽  
Thin Part ◽  
Free Media ◽  
Exogenous Substances

During incubation in vivo, exogenously applied ionic lanthanum comes to surround the numerous neurosecretory terminals which are found lying within or immediately beneath the acellular neural lamella ensheathing the nerves from fifth instar and adult specimens of Rhodnius prolixus. The lanthanum does not penetrate beyond the cellular perineurium, which completely surrounds the non-neurosecretory axons in these nerves and constitutes a form of ‘blood-brain barrier’. In some cases, however, lanthanum is found in the vicinity of a neurosecretory axon lying beneath the perineurium, where it can be assumed to have leaked in from the neurosecretory terminal lying free in the neural lamella. When nerves are incubated in calcium-free media, regions with an attenuated perineurium become ‘leaky’, in that lanthanum is found lying in those extracellular spaces between axons and glia which lie immediately below the thin part of the perineurial layer. Bathing solutions made slightly hyperosmotic to the haemolymph with sucrose have no apparent disruptive effects on the barrier. When the tissues are incubated in more hypertonic solutions, the perineurial barrier becomes ‘leaky’ throughout, and tracer pervades beyond its cells into all the intercellular spaced between glia and axons. The possible role of the zonulae occludentes in both the maintenance of the perineurial barrier and in the formation of interglial occlusions to local penetration of exogenous substances is considered.

Dopant Diffusion Barrier Properties of Ultrathin, Chemically Grown Oxide Films

2006 ◽  
Vol 9 (2) ◽  
pp. G34-G36
Author(s):  
S. B. Herner ◽  
V. L. Eckert
Keyword(s):  
Diffusion Barrier ◽  
Oxide Films ◽  
Barrier Properties ◽  
Dopant Diffusion

Diffusion barrier properties of metallorganic chemical vapor deposited NbN O C films for Cu metallization

2003 ◽  
Vol 163-164 ◽  
pp. 214-219 ◽  
Author(s):  
C.W Wu ◽  
W.C Gau ◽  
J.C Hu ◽  
T.C Chang ◽  
C.H Chen ◽  
...  
Keyword(s):  
Diffusion Barrier ◽  
Chemical Vapor ◽  
Barrier Properties ◽  
Cu Metallization ◽  
Chemical Vapor Deposited

In Vitro Assessment of in Vivo Damage to the Barrier Properties of Pig Skin Caused by a Complex Mixture

1993 ◽  
Vol 12 (3) ◽  
pp. 239-248 ◽  
Author(s):  
Barbara W. Kemppainen ◽  
Pramod Terse ◽  
M. S. Madhyastha ◽  
S. D. Lenz ◽  
W. G. Palmer ◽  
...  
Keyword(s):  
Complex Mixture ◽  
Barrier Properties ◽  
Pig Skin ◽  
In Vitro Assessment

Diffusion barrier properties of amorphous TiB2 for application in Cu metallization

2002 ◽  
Vol 91 (9) ◽  
pp. 6099-6104 ◽  
Author(s):  
Joshua Pelleg ◽  
G. Sade
Keyword(s):  
Diffusion Barrier ◽  
Barrier Properties ◽  
Cu Metallization

The blood-testis barrier in the toad (Bufo arenarum hensel): A freeze-fracture and lanthanum tracer study

1983 ◽  
Vol 205 (4) ◽  
pp. 387-396 ◽  
Author(s):  
Juan C. Cavicchia ◽  
Gustavo A. Moviglia
Keyword(s):  
Freeze Fracture ◽  
Tracer Study ◽  
Bufo Arenarum ◽  
Lanthanum Tracer ◽  
Toad Bufo ◽  
Blood Testis Barrier
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