SELECTIVE ISOLATION OF HUMAN X-BEARING SPERM BY DIFFERENTIAL VELOCITY SEDIMENTATION IN PERCOLL DENSITY GRADIENTS

1984 ◽  
Vol 5 (2) ◽  
pp. 187-194 ◽  
Author(s):  
SATORU KANEKO ◽  
SHIGERU OSHIO ◽  
TOSHIFUMI KOBAYASHI ◽  
HIDEO MOHRI ◽  
RIHACHI IIZUKA
Keyword(s):  
Velocity Sedimentation ◽  
Density Gradients ◽  
Selective Isolation

Fractionation of human cultured lymphoblasts into cell cycle phases by velocity sedimentation in density gradients

1976 ◽  
Vol 2 (2) ◽  
pp. 367-369
Author(s):  
L. M. Jerry ◽  
A. K. Sullivan ◽  
L. S. Adams ◽  
R. Turner
Keyword(s):  
Cell Cycle ◽  
Velocity Sedimentation ◽  
Density Gradients ◽  
Cell Cycle Phases

A method for selective separation of scandium (III) from yttrium and a number of rare-earth elements for its subsequent determination

2018 ◽  
Vol 84 (11) ◽  
pp. 23-27
Author(s):  
M. I. Degtev ◽  
A. A. Yuminova ◽  
A. S. Maksimov ◽  
A. P. Medvedev
Keyword(s):  
Rare Earth ◽  
Aqueous Phase ◽  
Selective Isolation ◽  
Optimum Ratio ◽  
Extraction Condition ◽  
Sulfosalicylic Acid ◽  
Salting Out ◽  
Subsequent Determination ◽  
Toxic Organic Solvents ◽  
Metal Ions Extraction

The possibility of using an aqueous stratified system of antipyrine — sulfosalicylic acid — water for the selective isolation of scandium macro- and microquantities for subsequent determination is studied. The proposed extraction system eliminates the usage of toxic organic solvents. The organic phase with a volume of 1.2 to 2.0 ml, resulting from delamination of the aqueous phase containing antipyrine and sulfosalicylic acid is analysed to assess the possibility of using such systems for metal ions extraction. Condition necessary for the formation of such a phase were specified: the ratio of the initial components, their concentration, presence of inorganic salting out agents. The optimum ratio of antipyrine to sulfosalicylic acid is 2:1 at concentrations of 0.6 and 0.3 mol/liter in a volume of the aqueous phase of 10 ml. The obtained phase which consists of antipyrinium sulfosalicylate, free antipyrine and water, quantitatively extracts macro- and microquantities of scandium at pH = 1.54. Macro- and microquantities of yttrium, terbium, lanthanum, ytterbium and gadolinium are not extracted under the aforementioned conditions thus providing selective isolation of scandium from the bases containing yttrium, ytterbium, terbium, lanthanum, and gadolinium.

The Roles of VxB and Density Gradients in Plasma Electric Fields Measured from the Shuttle Orbiter.

1985 ◽  
Author(s):  
J. R. Lilley ◽  
Katz Jr. ◽  
Cooke I. ◽  
D. L.
Keyword(s):  
Electric Fields ◽  
Density Gradients

Preparation of Sensitive Linear Density Gradients

1961 ◽  
Vol 25 (5) ◽  
pp. 357-359 ◽  
Author(s):  
Alvin H. Beavers
Keyword(s):  
Linear Density ◽  
Density Gradients

Design optimization of multimorphology surface-based lattice structures with density gradients

2021 ◽  
Author(s):  
Xin Shi ◽  
Wenhe Liao ◽  
Tingting Liu ◽  
Changdong Zhang ◽  
Dawei Li ◽  
...  
Keyword(s):  
Design Optimization ◽  
Density Gradients ◽  
Lattice Structures

A Requirement for Recombinational Repair in Saccharomyces cerevisiae Is Caused by DNA Replication Defects of mec1 Mutants

Genetics ◽  
1999 ◽  
Vol 153 (2) ◽  
pp. 595-605 ◽  
Author(s):  
Bradley J Merrill ◽  
Connie Holm
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Synthetic Lethality ◽  
Velocity Sedimentation ◽  
Recombinational Repair ◽  
Repair Pathway ◽  
Dna Breaks ◽  
Single Stranded Dna ◽  
Double Stranded Dna

Abstract To examine the role of the RAD52 recombinational repair pathway in compensating for DNA replication defects in Saccharomyces cerevisiae, we performed a genetic screen to identify mutants that require Rad52p for viability. We isolated 10 mec1 mutations that display synthetic lethality with rad52. These mutations (designated mec1-srf for synthetic lethality with rad-fifty-two) simultaneously cause two types of phenotypes: defects in the checkpoint function of Mec1p and defects in the essential function of Mec1p. Velocity sedimentation in alkaline sucrose gradients revealed that mec1-srf mutants accumulate small single-stranded DNA synthesis intermediates, suggesting that Mec1p is required for the normal progression of DNA synthesis. sml1 suppressor mutations suppress both the accumulation of DNA synthesis intermediates and the requirement for Rad52p in mec1-srf mutants, but they do not suppress the checkpoint defect in mec1-srf mutants. Thus, it appears to be the DNA replication defects in mec1-srf mutants that cause the requirement for Rad52p. By using hydroxyurea to introduce similar DNA replication defects, we found that single-stranded DNA breaks frequently lead to double-stranded DNA breaks that are not rapidly repaired in rad52 mutants. Taken together, these data suggest that the RAD52 recombinational repair pathway is required to prevent or repair double-stranded DNA breaks caused by defective DNA replication in mec1-srf mutants.

High critical flux density gradients near the surface of superconducting niobium

1979 ◽  
Vol 36 (1-2) ◽  
pp. 33-46 ◽  
Author(s):  
A. S. Brito ◽  
G. Zerweck ◽  
O. F. de Lima
Keyword(s):  
Flux Density ◽  
Density Gradients ◽  
Critical Flux
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