scholarly journals From immobilized cells to motile cells on a bed-of-nails: effects of vertical nanowire array density on cell behaviour

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Henrik Persson ◽  
Zhen Li ◽  
Jonas O. Tegenfeldt ◽  
Stina Oredsson ◽  
Christelle N. Prinz
Keyword(s):  
Immobilized Cells ◽  
Nanowire Array ◽  
Cell Behaviour ◽  
Motile Cells ◽  
Array Density

scholarly journals FACTORS AFFECTING THE REDISTRIBUTION OF SURFACE-BOUND CONCANAVALIN A ON HUMAN POLYMORPHONUCLEAR LEUKOCYTES

1974 ◽  
Vol 62 (2) ◽  
pp. 351-365 ◽  
Author(s):  
Graeme B. Ryan ◽  
Joan Z. Borysenko ◽  
Morris J. Karnovsky
Keyword(s):  
Concanavalin A ◽  
Polymorphonuclear Leukocytes ◽  
Cytochalasin B ◽  
Immobilized Cells ◽  
Fluorescein Isothiocyanate ◽  
Cross Linking ◽  
Con A ◽  
Factors Affecting ◽  
Motile Cells ◽  
Cellular Locomotion

Human neutrophil polymorphonuclear leukocytes (PMN) were studied to determine the influence of cellular locomotion upon the redistribution and capping of concanavalin A (Con A). Con A was detected by fluorescence (using Con A conjugated to fluorescein isothiocyanate [Con A-FITC]), or on shadow-cast replicas (using Busycon canaliculatum hemocyanin as a marker for Con A). After labeling with Con A 100 µg/ml at 4°C and warming to 37°C, locomotion occurred, and the Con A quickly aggregated into a cap at the trailing end of the cell. When locomotion was inhibited (with cytochalasin B, or by incubation in serum-free medium at 18°C) Con A rapidly formed a cap over the central region of the cell. Iodoacetamide inhibited capping. PMN labeled with FITC, a monovalent ligand, developed caps at the tail only on motile cells; FITC remained dispersed on immobilized cells. PMN exposed to Con A 100 µg/ml at 37°C bound more lectin than at 4°C, became immobilized, and showed slow central capping. The Con A soon became internalized to form a perinuclear ring. Such treatment in the presence of cytochalasin B resulted in the quick formation of persistent central caps. Colchicine (or prior cooling) protected PMN from the immobilizing effect of Con A, and tail caps were found on 30–40% of cells. Immobilization of colchicine-treated cells caused Con A to remain in dispersed clusters. Thus, capping on PMN is a temperature- and energy-dependent process that proceeds independently of cellular locomotion, provided a colchicine-sensitive system is intact and the ligand is capable of cross linking receptors. On the other hand, if the cell does move, it appears that ligands may be swept into a cap at the tail whether cross-linking occurs or not.

Density-Controlled Growth of Well-Aligned ZnO Nanowires Using Hydrothermal Method

2011 ◽  
Vol 320 ◽  
pp. 130-134
Author(s):  
Yung Kuan Tseng ◽  
Ching Chih Hsiao ◽  
Mong Chun Hong
Keyword(s):  
Zinc Oxide ◽  
Hydrothermal Method ◽  
Nanowire Array ◽  
Zinc Powder ◽  
Zno Nanowires ◽  
Zinc Oxide Nanowires ◽  
Oxide Nanowires ◽  
Density Control ◽  
Azo Thin Film ◽  
Array Density

This study is mainly to control the density of zinc oxide nanowires arrays as main axis. We spin coated AZO thin film to Si/SiO2substrate by hydrothermal method growing ZnO nanowire arrays on a substrate by spin coating a layer of zinc powder mixed with SiO2film, and controlled the concentration of zinc. We can easily obtain a nanowire array density control. In this experiment, we investigated different centrifugation speed, time, zinc concentration, temperature and other variable parameters. Through field emission scanning electron microscopy observation of dispersive zinc oxide nanowires and dispersion situation, it was found that using different doping concentration and rotation speed, different densities can be successfully obtained for ZnO nanowires array. Dispersion of zinc oxide nanowires by hydrothermal method with increasing time, the diameter and length will increase significantly.

Modulated polarization microscopy displays the dynamics of cytoskeletal structures in living, motile cells

1995 ◽  
Vol 53 ◽  
pp. 902-903
Author(s):  
J. R. Kuhn ◽  
M. Poenie
Keyword(s):  
Mitotic Spindle ◽  
Actin Filaments ◽  
Cell Shape ◽  
Dynamic Structure ◽  
Living Cells ◽  
Cytoskeletal Proteins ◽  
Polarization Microscopy ◽  
Video Enhancement ◽  
Ultrastructural Studies ◽  
Motile Cells

Cell shape and movement are controlled by elements of the cytoskeleton including actin filaments an microtubules. Unfortunately, it is difficult to visualize the cytoskeleton in living cells and hence follow it dynamics. Immunofluorescence and ultrastructural studies of fixed cells while providing clear images of the cytoskeleton, give only a static picture of this dynamic structure. Microinjection of fluorescently Is beled cytoskeletal proteins has proved useful as a way to follow some cytoskeletal events, but long terry studies are generally limited by the bleaching of fluorophores and presence of unassembled monomers.Polarization microscopy has the potential for visualizing the cytoskeleton. Although at present, it ha mainly been used for visualizing the mitotic spindle. Polarization microscopy is attractive in that it pro vides a way to selectively image structures such as cytoskeletal filaments that are birefringent. By combing ing standard polarization microscopy with video enhancement techniques it has been possible to image single filaments. In this case, however, filament intensity depends on the orientation of the polarizer and analyzer with respect to the specimen.

Airway dendritic cell behaviour is influenced by neuropeptide release from sensory nerves

Pneumologie ◽  
2011 ◽  
Vol 65 (12) ◽  
Author(s):  
S Voedisch ◽  
S Rochlitzer ◽  
E Spies ◽  
A Braun
Keyword(s):  
Dendritic Cell ◽  
Sensory Nerves ◽  
Cell Behaviour ◽  
Neuropeptide Release

Design of a continuous flow immobilized-cell reactor for biosynthetical production of L-aspartic acid

1985 ◽  
Vol 50 (10) ◽  
pp. 2122-2133 ◽  
Author(s):  
Jindřich Zahradník ◽  
Marie Fialová ◽  
Jan Škoda ◽  
Helena Škodová
Keyword(s):  
Aspartic Acid ◽  
Continuous Flow ◽  
Immobilized Cells ◽  
Scale Up ◽  
Fixed Bed ◽  
Packed Bed ◽  
Fixed Bed Reactor ◽  
Experimental Program ◽  
Design Parameters ◽  
Immobilized Cell

An experimental study was carried out aimed at establishing a data base for an optimum design of a continuous flow fixed-bed reactor for biotransformation of ammonium fumarate to L-aspartic acid catalyzed by immobilized cells of the strain Escherichia alcalescens dispar group. The experimental program included studies of the effect of reactor geometry, catalytic particle size, and packed bed arrangement on reactor hydrodynamics and on the rate of substrate conversion. An expression for the effective reaction rate was derived including the effect of mass transfer and conditions of the safe conversion-data scale-up were defined. Suggestions for the design of a pilot plant reactor (100 t/year) were formulated and decisive design parameters of such reactor were estimated for several variants of problem formulation.

Sign in / Sign up

Export Citation Format

Share Document