Structural models and barrier properties of amine-terminated trialkoxysilane monolayers incubated in nonpolar vs. polar protic solvents

1978 ◽

Vol 36 (2) ◽

pp. 336-337

Author(s):

B. Van Deurs ◽

J. K. Koehler

Keyword(s):

Choroid Plexus ◽

Present Report ◽

Freeze Fracture ◽

Barrier Properties ◽

Cell Junctions ◽

Structural Basis ◽

Apical Surface ◽

Choroid Plexus Epithelium ◽

Solid Nitrogen ◽

Special Composition

The choroid plexus epithelium constitutes a blood-cerebrospinal fluid (CSF) barrier, and is involved in regulation of the special composition of the CSF. The epithelium is provided with an ouabain-sensitive Na/K-pump located at the apical surface, actively pumping ions into the CSF. The choroid plexus epithelium has been described as “leaky” with a low transepithelial resistance, and a passive transepithelial flux following a paracellular route (intercellular spaces and cell junctions) also takes place. The present report describes the structural basis for these “barrier” properties of the choroid plexus epithelium as revealed by freeze fracture.Choroid plexus from the lateral, third and fourth ventricles of rats were used. The tissue was fixed in glutaraldehyde and stored in 30% glycerol. Freezing was performed either in liquid nitrogen-cooled Freon 22, or directly in a mixture of liquid and solid nitrogen prepared in a special vacuum chamber. The latter method was always used, and considered necessary, when preparations of complementary (double) replicas were made.

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Growth of near noble metal Pd and Pt thin film silicides morphology and structure

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100112464 ◽

1984 ◽

Vol 42 ◽

pp. 498-499

Author(s):

E. I. Alessandrini ◽

M. O. Aboelfotoh

Keyword(s):

Noble Metals ◽

Annealing Temperature ◽

Chemical Compounds ◽

Barrier Properties ◽

Solid State Reactions ◽

Transmission Electron ◽

Stable Chemical ◽

Metal Thickness ◽

Amorphous Si ◽

Si Films

Considerable interest has been generated in solid state reactions between thin films of near noble metals and silicon. These metals deposited on Si form numerous stable chemical compounds at low temperatures and have found applications as Schottky barrier contacts to silicon in VLSI devices. Since the very first phase that nucleates in contact with Si determines the barrier properties, the purpose of our study was to investigate the silicide formation of the near noble metals, Pd and Pt, at very thin thickness of the metal films on amorphous silicon.Films of Pd and Pt in the thickness range of 0.5nm to 20nm were made by room temperature evaporation on 40nm thick amorphous Si films, which were first deposited on 30nm thick amorphous Si3N4 membranes in a window configuration. The deposition rate was 0.1 to 0.5nm/sec and the pressure during deposition was 3 x 10 -7 Torr. The samples were annealed at temperatures in the range from 200° to 650°C in a furnace with helium purified by hot (950°C) Ti particles. Transmission electron microscopy and diffraction techniques were used to evaluate changes in structure and morphology of the phases formed as a function of metal thickness and annealing temperature.

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Changes in corneocyte element concentrations occur in skin inner stratum corneum

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134326 ◽

1990 ◽

Vol 48 (2) ◽

pp. 146-147

Author(s):

R. R. Warner

Keyword(s):

Stratum Corneum ◽

Human Skin ◽

Element Concentration ◽

Skin Barrier ◽

Barrier Properties ◽

Brick Wall ◽

Inorganic Elements ◽

Dry Skin ◽

Skin Biopsies ◽

Intercellular Lipid

Keratinocytes undergo maturation during their transit through the viable layers of skin, and then abruptly transform into flattened, anuclear corneocytes that constitute the cellular component of the skin barrier, the stratum corneum (SC). The SC is generally considered to be homogeneous in its structure and barrier properties, and is often shown schematically as a featureless brick wall, the “bricks” being the corneocytes, the “mortar” being intercellular lipid. Previously we showed the outer SC was not homogeneous in its composition, but contained steep gradients of the physiological inorganic elements Na, K and Cl, likely originating from sweat salts. Here we show the innermost corneocytes in human skin are also heterogeneous in composition, undergoing systematic changes in intracellular element concentration during transit into the interior of the SC.Human skin biopsies were taken from the lower leg of individuals with both “good” and “dry” skin and plunge-frozen in a stirred, cooled isopentane/propane mixture.

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Validation of the Short Dark Triad in a German Sample

European Journal of Psychological Assessment ◽

10.1027/1015-5759/a000617 ◽

2020 ◽

pp. 1-12

Author(s):

Caroline Wehner ◽

Ulrike Maaß ◽

Marius Leckelt ◽

Mitja D. Back ◽

Matthias Ziegler

Keyword(s):

Sensation Seeking ◽

Factor Model ◽

Structural Models ◽

Self Esteem ◽

Dark Triad ◽

Fit Indices ◽

Nomological Network ◽

Competitive Test ◽

Three Factor ◽

Behavioral Criteria

Abstract. The structure, correlates, and assessment of the Dark Triad are widely discussed in several fields of psychology. Based on the German version of the Short Dark Triad (SDT), we add to this by (a) providing a competitive test of existing structural models, (b) testing the nomological network, and (c) proposing an ultrashort 9-item version of the SDT (uSDT). A sample of N = 969 participants provided data on the SDT and a range of further measures. Our competitive test of five structural models revealed that fit indices and nomological network assumptions were best met in a three-factor model, with separate factors for psychopathy, Machiavellianism, and narcissism. The results provided an extensive overview of the raw, unique, and shared associations of Dark Triad dimensions with narcissism facets, sadism, impulsivity, self-esteem, sensation seeking, the Big Five, maladaptive personality traits, sociosexual orientation, and behavioral criteria. Finally, the uSDT exhibited satisfactory psychometric properties. The highest overlap in expected relations between SDT and uSDT, and convergent and discriminant measures was also found for the three-factor model. Our study underlines the utility of a three-factor model of the Dark Triad, extends findings on its nomological network, and provides an ultrashort instrument.

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