Voltage gradients and microtubules both involved in intercellular protein and mitochondria transport in the telotrophic ovariole of Dysdercus intermedius

1987 ◽  
Vol 196 (6) ◽  
pp. 391-396 ◽  
Author(s):  
Axel M�nz ◽  
Frank Dittmann
Keyword(s):  
Voltage Gradients ◽  
Dysdercus Intermedius ◽  
Telotrophic Ovariole

Failure Localization of Intermittent Short Failures Caused by Vertical Conductive Anodic Filament Formation

2014 ◽  
Author(s):  
Daniel Nuez ◽  
Phoumra Tan
Keyword(s):  
Glass Fibers ◽  
Vertical Plane ◽  
Axis Formation ◽  
Metal Trace ◽  
Conductive Anodic Filament ◽  
Plated Through Hole ◽  
Voltage Gradients ◽  
Ic Package ◽  
Through Hole ◽  
Failure Localization

Abstract Conductive anodic filament (CAF) formation is a mechanism caused by an electrochemical migration of metals from a metal trace in ICs or in PCBs. This is commonly caused by the moisture build-up in the affected metal terminals in an IC package or PC board caused by critical temperature, high humidity and high voltage gradients conditions. This phenomenon is known to have caused catastrophic field failures on various OEMs electronic components in the past [1,7]. Most published articles on CAF described the formation of the filament in a lateral formation through the glass fiber interfaces between two adjacent metal planes [1-6, 8-12]. One common example is the CAF formation seen between PTH (Plated through Hole) in the laminated substrate with two different potentials causing shorts [1-6, 8-12]. In this paper, the Cu filament grows in a vertical fashion (z-axis formation) creating a vertical plane shorts between the upper and lower metal terminals in a laminated IC package substrate. The copper growth migration does not follow the fiber strands laterally or vertically through them. Instead, it grows through the stress created gaps between the impregnated carbon epoxy fillers from the upper metal trace to the lower metal trace with two different potentials, between the glass fibers. This vertical CAF mechanism creates a low resistive short that was sometimes found to be intermittent in nature. This paper presents some successful failure analysis approaches used to isolate and detect the failure locations for this type of failing devices. This paper also exposes the unique physical appearance of the vertical CAF formation.

Production of grape pekmez by Ohmic heating-assisted vacuum evaporation

2021 ◽  
pp. 108201322199161
Author(s):  
Merve Tuçe Tunç ◽  
Arda Akdoğan ◽  
Cemalettin Baltacı ◽  
Zeliha Kaya ◽  
Halil İbrahim Odabaş
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Ohmic Heating ◽  
Vacuum Evaporation ◽  
Voltage Gradient ◽  
Evaporation Process ◽  
Significant Difference ◽  
Total Process ◽  
Energy Consumptions ◽  
Voltage Gradients

Pekmez is a concentrated syrup-like food conventionally produced by vacuum evaporation process from sugar-rich fruits. In this study, the applicability of grape pekmez production by ohmic heating assisted vacuum evaporation (ΩVE) method was investigated. Conventional vacuum evaporation (CVE) and ΩVE methods were compared in terms of physicochemical properties, HMF (5-hydroxymethylfurfural) contents, rheological properties, and energy consumptions. ΩVE was run at four different voltage gradients (17.5, 20, 22.5, and 25 V/cm). Total process times for grape pekmez production were determined as 57, 28.5, 32, 39, and 50 minutes for CVE, ΩVE (25 V/cm), ΩVE (22.5 V/cm), ΩVE (20 V/cm) and ΩVE (17.5 V/cm), respectively. Energy consumption of CVE method was higher than ΩVE method for all voltage gradients. Energy efficiency increased as the voltage gradient increased. There was no significant difference between CVE and ΩVE methods for HMF contents. The results show that the ΩVE method could be an alternative to the CVE process for grape pekmez production.

Autonomously replicating episomes contain mdr1 genes in a multidrug-resistant human cell line

1989 ◽  
Vol 9 (1) ◽  
pp. 109-115
Author(s):  
J C Ruiz ◽  
K H Choi ◽  
D D von Hoff ◽  
I B Roninson ◽  
G M Wahl
Keyword(s):  
Gamma Irradiation ◽  
Gene Amplification ◽  
Human Tumor ◽  
Human Cell Line ◽  
Multidrug Resistant ◽  
Cross Resistance ◽  
Chromosomal Dna ◽  
A Cell ◽  
Shift Experiment ◽  
Voltage Gradients

Gene amplification in human tumor cells is frequently mediated by extrachromosomal elements (e.g., double minute chromosomes [DMs]). Recent experiments have shown that DMs can be formed from smaller, submicroscopic circular precursors referred to as episomes (S. M. Carroll, M. L. DeRose, P. Gaudray, C. M. Moore, D. R. Needham-Vandevanter, D. D. Von Hoff and G. M. Wahl, Mol. Biol. 8:1525-1533, 1988). To investigate whether episomes are generally involved as intermediates in gene amplification, we determined whether they mediate the amplification of the mdr1 gene, which when overexpressed engenders cross resistance to multiple lipophilic drugs. A variety of methods including electrophoresis of undigested DNAs in high-voltage gradients, NotI digestion, and production of double-strand breaks by gamma irradiation were used to distinguish between mdr1 sequences amplified on submicroscopic circular molecules and those amplified within DMs or chromosomal DNA. The gamma-irradiation procedure provides a new method for detecting and determining the size of circular molecules from 50 kilobases (kb) to greater than 1,000 kb. These methods revealed that some of the amplified mdr1 genes in vinblastine-resistant KB-V1 cells are contained in supercoiled circular molecules of approximately 600 and approximately 750 kb. Analysis of the replication of these molecules by a Meselson-Stahl density shift experiment demonstrated that they replicate approximately once in a cell cycle. The data lend further support to a model for gene amplification in which DMs are generally formed from smaller, autonomously replicating precursors.

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