scholarly journals Note on the surface electric charges of living cells

1911 ◽  
Vol 84 (571) ◽  
pp. 217-226 ◽  
Keyword(s):  
Thin Films ◽  
Electric Current ◽  
Living Cells ◽  
Yeast Cells ◽  
Microscopical Examination ◽  
Animal Cells ◽  
Cover Glass ◽  
Free Living ◽  
The Way

The movement of free living cells suspended in a fluid through which an electric current is passing towards one or other of the poles has been described by many observes. In almost every case the movement has been observed in thin films of fluid under a cover-glass mounted in the way usual for microscopical examination. The cells do not always all move in the same direction; some migrate towards the anode, others to the cathode, and Thornton found that in mixed suspensions of diatoms and amœbæ, or yeast cells and red blood corpuscles, the animal cells migrated to the anode, the vegetable cells to the cathode. He infers from this that animal and vegetable cells are oppositely electrified, the former being negative, the latter positive, to the fluid. It is obvious at the outset that there are exceptions to this generalisation, for Becholt describes a movement of bacteria towards the anode, the direction being reserved after agglutination. Dale and Lillie also have described movements of animal cells to the cathode, but Thornton points out with some justice that in these cases the cells were not in their normal habitat.

An Extremely Weak Electric Current System Induces Anti-apoptotic Effects and Anti-necrotic Effects in Living Cells

2015 ◽  
Vol 3 (2) ◽  
pp. 102-111 ◽  
Author(s):  
Daibo Kojima ◽  
Hitomi Nishinakamura ◽  
Takeshi Itoh ◽  
Shohta Kodama
Keyword(s):  
Electric Current ◽  
Current System ◽  
Living Cells ◽  
Apoptotic Effects

scholarly journals SIMILARITY OF THE KINETICS OF INVERTASE ACTION IN VIVO AND IN VITRO. II

1932 ◽  
Vol 16 (2) ◽  
pp. 233-242 ◽  
Author(s):  
B. G. Wilkes ◽  
Elizabeth T. Palmer
Keyword(s):  
Physiological Activity ◽  
Outer Region ◽  
Living Cells ◽  
Yeast Cells ◽  
Live Cells ◽  
Intracellular Enzyme ◽  
Relationship Of ◽  
Kinetics Of

1. The pH-activity relationship of invertase has been studied in vivo and in vitro under identical external environmental conditions. 2. The effect of changing (H+) upon the sucroclastic activity of living cells of S. cerevisiae and of invertase solutions obtained therefrom has been found, within experimental error, to be identical. 3. The region of living yeast cells in which invertase exerts its physiological activity changes its pH freely and to the same extent as that of the suspending medium. It is suggested that this may indicate that this intracellular enzyme may perform its work somewhere in the outer region of the cell. 4. In using live cells containing maltase, no evidence of increased sucroclastic activity around pH 6.9, due to the action of Weidenhagen's α-glucosidase (maltase), was found.

Foundational Tools for Building a New Bioeconomy

2021 ◽  
Vol 26 (2) ◽  
Author(s):  
Daniel S. Levine
Keyword(s):  
Information Technology ◽  
Critical Role ◽  
Living Cells ◽  
Diagnosis And Treatment ◽  
The Way

While biotechnology has been transforming the diagnosis and treatment of disease, it has also been altering everything from the production of crops to how we manufacture goods. Berkeley Lights, which sits at the nexus of biotechnology, microfluidics, and information technology, is playing a critical role in enabling the way living cells can be harnessed as microscopic factories to power the emerging bioeconomy.

scholarly journals Engineered ACC deaminase-expressing free-living cells of Mesorhizobium loti show increased nodulation efficiency and competitiveness on Lotus spp.

2010 ◽  
Vol 56 (4) ◽  
pp. 331-338 ◽  
Author(s):  
Valeria P. Conforte ◽  
Mariela Echeverria ◽  
Cintia Sánchez ◽  
Rodolfo A. Ugalde ◽  
Ana B. Menéndez ◽  
...  
Keyword(s):  
Acc Deaminase ◽  
Living Cells ◽  
Free Living ◽  
Mesorhizobium Loti

scholarly journals THE SELECTIVE ABSORPTION OF POTASSIUM BY ANIMAL CELLS

1921 ◽  
Vol 4 (2) ◽  
pp. 141-148 ◽  
Author(s):  
Philip H. Mitchell ◽  
J. Walter Wilson ◽  
Ralph E. Stanton
Keyword(s):  
Electronic Structure ◽  
Cesium Chloride ◽  
Ringer Solution ◽  
Living Cells ◽  
Selective Absorption ◽  
Physiological Effects ◽  
Equivalent Amount ◽  
Animal Cells ◽  
Relationship Of ◽  
Resting Muscle

1. Frog muscles perfused with Ringer solution in which potassium chloride has been replaced by an equivalent amount of rubidium or cesium chloride take up rubidium or cesium and incorporate them into the tissue substance in such form as to be retained during a subsequent perfusion with potassium-free Ringer solution, provided the muscles contract during the first perfusion. Retention of rubidium or cesium by a resting muscle does not occur. 2. Rats on synthetic diets, adequate in all respects except that potassium was replaced by an equivalent amount of rubidium or cesium, died after a period varying from 10 to 17 days with characteristic symptoms including tetanic spasms. Muscle, heart, liver, kidney, spleen, and lung tissues were then found to contain significant amounts of rubidium or cesium. The concentration of these metals in the muscle amounted, in some cases, as shown by a spectroscopic estimation, to about half the concentration of potassium normally found in mammallian muscle. 3. The results are regarded as tending to confirm the theory that the peculiarities in the physiological effects of potassium, including the facility with which it is "selected" by living cells in preference to sodium, are related to the electronic structure of the potassium ion as compared with that of similar ions. The possible relationship of the comparative migration velocity, a function of the electronic structure, to physiological effects is suggested.

Electric current induced extrinsic asymmetric – behavior in epitaxial thin films on single crystal substrates

2011 ◽  
Vol 151 (13) ◽  
pp. 943-946 ◽  
Author(s):  
Guanlin Xie ◽  
Yuhang Wang ◽  
Yimin Yang ◽  
Hongliang Liu ◽  
Tianling Ren ◽  
...  
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Electric Current ◽  
Epitaxial Thin Films ◽  
Asymmetric Behavior

Formation and Characterization of the Quasicrystal Films

2007 ◽  
Vol 546-549 ◽  
pp. 1699-1702
Author(s):  
Xi Ying Zhou ◽  
Liang He ◽  
Yan Hui Liu
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Electric Current ◽  
Wear Behavior ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Al-Cu-Fe quasicrystals powder was used to prepare the thin films on the surface of the A3 steel by the means of DMD-450 vacuum evaporation equipment. The thin films with different characterization were obtained through different parameters. The microstructures of the thin films were analyzed by Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). Additionally, the nano-hardness and the modulus of the films are tested by MTS and Neophot micro-hardness meter. The results showed that the modulus of the films was about 160GPa. Nano hardness of the films was about 7.5 Gpa. The films consisted of CuAl2, AlCu3. The thickness and the micro-hardness of the films are improved. In same way, with the increase of the electric current, the thickness and the hardness of the films are also improved. Along with increase of the time and the electric current, the wear behavior of the films was improved. To some extent, the microstructure of films contained the quasicrystal phase of Al65Cu20Fe15.

scholarly journals Microtubule dynamics and chromosome motion visualized in living anaphase cells.

1988 ◽  
Vol 106 (4) ◽  
pp. 1185-1192 ◽  
Author(s):  
G J Gorbsky ◽  
P J Sammak ◽  
G G Borisy
Keyword(s):  
Chromosome Segregation ◽  
Digital Imaging ◽  
Living Cells ◽  
Microtubule Dynamics ◽  
Chromosome Movement ◽  
Animal Cells ◽  
Digital Imaging Microscopy ◽  
Opposite Pole ◽  
Anaphase B ◽  
Chromosome Motion

Chromosome segregation in most animal cells is brought about through two events: the movement of the chromosomes to the poles (anaphase A) and the movement of the poles away from each other (anaphase B). Essential to an understanding of the mechanism of mitosis is information on the relative movements of components of the spindle and identification of sites of subunit loss from shortening microtubules. Through use of tubulin derivatized with X-rhodamine, photobleaching, and digital imaging microscopy of living cells, we directly determined the relative movements of poles, chromosomes, and a marked domain on kinetochore fibers during anaphase. During chromosome movement and pole-pole separation, the marked domain did not move significantly with respect to the near pole. Therefore, the kinetochore microtubules were shortened by the loss of subunits at the kinetochore, although a small amount of subunit loss elsewhere was not excluded. In anaphase A, chromosomes moved on kinetochore microtubules that remained stationary with respect to the near pole. In anaphase B, the kinetochore fiber microtubules accompanied the near pole in its movement away from the opposite pole. These results eliminate models of anaphase in which microtubules are thought to be traction elements that are drawn to and depolymerized at the pole. Our results are compatible with models of anaphase in which the kinetochore fiber microtubules remain anchored at the pole and in which microtubule dynamics are centered at the kinetochore.

scholarly journals Acetoacetyl Coenzyme A Reductase and Polyhydroxybutyrate Synthesis in Rhizobium(Cicer) sp. Strain CC 1192

1998 ◽  
Vol 64 (8) ◽  
pp. 2859-2863 ◽  
Author(s):  
Shahid N. Chohan ◽  
Les Copeland
Keyword(s):  
Coenzyme A ◽  
Citrate Synthase ◽  
Living Cells ◽  
High Ratio ◽  
Free Living ◽  
Insoluble Material ◽  
Living State ◽  
Biochemical Level ◽  
Coa Reductase ◽  
Acetoacetyl Coa Reductase

ABSTRACT Biochemical controls that regulate the biosynthesis of poly-3-hydroxybutyrate (PHB) were investigated in Rhizobium(Cicer) sp. strain CC 1192. This species is of interest for studying PHB synthesis because the polymer accumulates to a large extent in free-living cells but not in bacteroids during nitrogen-fixing symbiosis with chickpea (Cicer arietinumL.) plants. Evidence is presented that indicates that CC 1192 cells retain the enzymic capacity to synthesize PHB when they differentiate from the free-living state to the bacteroid state. This evidence includes the incorporation by CC 1192 bacteroids of radiolabel from [14C]malate into 3-hydroxybutyrate which was derived by chemically degrading insoluble material from bacteroid pellets. Furthermore, the presence of an NADPH-dependent acetoacetyl coenzyme A (CoA) reductase, which was specific forR-(−)-3-hydroxybutyryl-CoA and NADP+ in the oxidative direction, was demonstrated in extracts from free-living and bacteroid cells of CC 1192. Activity of this enzyme in the reductive direction appeared to be regulated at the biochemical level mainly by the availability of substrates. The CC 1192 cells also contained an NADH-specific acetoacetyl-CoA reductase which oxidizedS-(+)-3-hydroxybutyryl-CoA. A membrane preparation from CC 1192 bacteroids readily oxidized NADH but not NADPH, which is suggested to be a major source of reductant for nitrogenase. Thus, a high ratio of NADPH to NADP+, which could enhance delivery of reductant to nitrogenase, could also favor the reduction of acetoacetyl-CoA for PHB synthesis. This would mean that fine controls that regulate the partitioning of acetyl-CoA between citrate synthase and 3-ketothiolase are important in determining whether PHB accumulates.

Ability of free-living cells ofBradyrhizobium japonicum to denitrify in soils

1989 ◽  
Vol 7 (3) ◽  
pp. 219-224 ◽  
Author(s):  
G. A. Breitenbeck ◽  
J. M. Bremner
Keyword(s):  
Living Cells ◽  
Free Living
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