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1.
Voen Med Zh ; 334(1): 19-24, 2013 Jan.
Artigo em Russo | MEDLINE | ID: mdl-23805624

RESUMO

With the help of scanning electronic and atomic force microscopy structure of red blood cell membranes of the system blood-groove and microcirculatory channels is studied. It is established, that in early stages of skin wounds in a peripheral blood circulation appear compressed red blood cells, losing water. As a result the basic mechanism of destruction of red blood cell membranes are interlayered shifts and stratification. In red blood cells of microvasculature, on the contrary, red blood cells in state of vacuolar degeneration are indentified. It creates preconditions for hydration and bullous deformations of membranes. Porous structures of membranes of both types erythrocytes are exposed to expansion.


Assuntos
Citosol/ultraestrutura , Eritrócitos/química , Membranas Intracelulares/ultraestrutura , Pele/lesões , Pele/ultraestrutura , Ferimentos e Lesões , Procedimentos Cirúrgicos Dermatológicos , Intervenção Médica Precoce , Membrana Eritrocítica/ultraestrutura , Humanos , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Manejo de Espécimes , Ferimentos e Lesões/sangue , Ferimentos e Lesões/patologia , Ferimentos e Lesões/cirurgia
2.
Ultramicroscopy ; 148: 151-157, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25461592

RESUMO

We present a synthesis method to fabricate framed carbon-based nanostructures having highly anisotropic shapes, in particular, the nanofork and nanoscalpel structures which are obtained systematically under optimized growth conditions. A theoretical model is developed to explain the formation of such nanostructures on Si cantilevers and W etched wires exposed to a focused electron beam. We then demonstrate the potentials of these nanostructures as functional tips for scanning probe microscopy. Owing to their anisotropic shapes, such tips can be very useful for nanolithography, nanosurgery of biological objects, and precise manipulation with surface particles. Overall, our method provides a simple and robust way to produce functional scanning probe microscopy tips with variable shapes and enhanced capabilities for different applications compared to standard cantilevers.


Assuntos
Carbono/química , Microscopia de Varredura por Sonda/métodos , Nanoestruturas/química , Eritrócitos/ultraestrutura , Microscopia Eletrônica de Varredura , Nanotecnologia
3.
Biophys J ; 59(4): 889-93, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1712239

RESUMO

The molecular structure of channels formed by gramicidin A in a lipid membrane was imaged by a scanning tunneling microscope operating in air. The mono- and bimolecular films of lipid with gramicidin A were deposited onto a highly oriented pyrolitic graphite substrate by the Langmuir-Blodgett technique. It has been shown that under high concentration gramicidin A molecules can form in lipid films a quasi-regular, densely packed structure. Single gramicidin A molecules were imaged for the first time as well. The cavity of 0.4 +/- 0.05 nm in halfwidth was found on the scanning tunneling microscopy image of the gramicidin A molecule. The results of direct observation obtained by means of scanning tunneling microscope are in good agreement with the known molecular model of gramicidin A. It was shown that gramicidin A molecules can exist in a lipid monolayer as individual molecules or combined into clusters. The results demonstrate that scanning tunneling microscope can be used for high spatial resolution study of ionic channel structure.


Assuntos
Gramicidina/química , Canais Iônicos , Bicamadas Lipídicas , Modelos Biológicos , 1,2-Dipalmitoilfosfatidilcolina/química , Glicerídeos , Microscopia de Tunelamento/métodos , Modelos Moleculares , Conformação Molecular , Conformação Proteica
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