The role of impurity magnesium complexes in formation efficiency of F2+ laser color centers in LiF crystals

2021 ◽  
Author(s):  
L. I. Bryukvina ◽  
N. A. Ivanov ◽  
D. S. Glazunov
Keyword(s):  
Color Centers ◽  
Magnesium Complexes ◽  
Formation Efficiency

scholarly journals The role of heat effects in the process of formation of color centers in LiF during filamentation of femtosecond laser pulses

2019 ◽  
Vol 220 ◽  
pp. 02007
Author(s):  
A.V. Kuznetsov ◽  
V.P. Dresvyansky ◽  
O. Bukhtsoozh ◽  
S. Enkhbat ◽  
E.F. Martynovich
Keyword(s):  
Femtosecond Laser ◽  
Thermal Effects ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Color Centers ◽  
Heat Effects ◽  
Femtosecond Filamentation

The possibility of the influence of thermal effects on the formation of color centers during laser femtosecond filamentation in a LiF crystal has been investigated theoretically. The conditions are formulated under which the influence of thermal effects can be noticeable.

scholarly journals The role of hypoxia in the maintenance of hematopoietic stem cells

Blood ◽  
1993 ◽  
Vol 82 (7) ◽  
pp. 2031-2037 ◽  
Author(s):  
MG Cipolleschi ◽  
P Dello Sbarba ◽  
M Olivotto
Keyword(s):  
Colony Formation ◽  
Marrow Cell ◽  
Cell Number ◽  
In Vitro Assays ◽  
Hematopoietic Stem ◽  
Liquid Cultures ◽  
Formation Efficiency ◽  
Colony Formation Efficiency

Abstract Bone marrow cell liquid cultures were incubated at various oxygen concentrations ranging from 0% to 18% (air). The total number of cells in culture (CT) at the end of a 6-day incubation was found to be directly proportional to the oxygen concentration. As compared with air- incubated controls, cells recovered from severely hypoxic (1% oxygen) day-5 liquid cultures showed (1) the same day-7 colony-formation efficiency in semisolid culture (neutrophilic/monocytic colonies) or in spleen; (2) a higher day-14 spleen colony-formation efficiency; (3) an enhanced radio-protection ability; and (4) an increased marrow repopulation ability, as measured by determining either total cell number in recipient marrow MRAcell, or the capacity of the latter of generating day-7 neutrophilic/monocytic colonies in secondary in vitro assays (MRACFU-NM). Taking into account CT, the absolute numbers of progenitors in culture were also computed. The results showed that, with respect to time 0, incubation in air produced an increase in the number of day-7 CFUs and a decrease in the number of the other progenitors, whereas in hypoxic cultures all types of progenitors decreased. However, as compared with air-incubated controls, all progenitors, except cells sustaining MRACFU-NM, were reduced in hypoxic cultures. The degree of reduction paralleled the position of the progenitor in the hematopoietic hierarchy, being maximum for day-7 CFUs and null for cells sustaining MRACFU-NM, which, in fact, were better preserved in hypoxic cultures.

scholarly journals Classical versus Bridged Allyl Ligands in Magnesium Complexes: The Role of Solvent

2009 ◽  
Vol 131 (18) ◽  
pp. 6344-6345 ◽  
Author(s):  
Stephen C. Chmely ◽  
Christin N. Carlson ◽  
Timothy P. Hanusa ◽  
Arnold L. Rheingold
Keyword(s):  
Magnesium Complexes ◽  
Role Of Solvent ◽  
Allyl Ligands

scholarly journals The role of hypoxia in the maintenance of hematopoietic stem cells

Blood ◽  
1993 ◽  
Vol 82 (7) ◽  
pp. 2031-2037 ◽  
Author(s):  
MG Cipolleschi ◽  
P Dello Sbarba ◽  
M Olivotto
Keyword(s):  
Colony Formation ◽  
Marrow Cell ◽  
Cell Number ◽  
In Vitro Assays ◽  
Hematopoietic Stem ◽  
Liquid Cultures ◽  
Formation Efficiency ◽  
Colony Formation Efficiency

Bone marrow cell liquid cultures were incubated at various oxygen concentrations ranging from 0% to 18% (air). The total number of cells in culture (CT) at the end of a 6-day incubation was found to be directly proportional to the oxygen concentration. As compared with air- incubated controls, cells recovered from severely hypoxic (1% oxygen) day-5 liquid cultures showed (1) the same day-7 colony-formation efficiency in semisolid culture (neutrophilic/monocytic colonies) or in spleen; (2) a higher day-14 spleen colony-formation efficiency; (3) an enhanced radio-protection ability; and (4) an increased marrow repopulation ability, as measured by determining either total cell number in recipient marrow MRAcell, or the capacity of the latter of generating day-7 neutrophilic/monocytic colonies in secondary in vitro assays (MRACFU-NM). Taking into account CT, the absolute numbers of progenitors in culture were also computed. The results showed that, with respect to time 0, incubation in air produced an increase in the number of day-7 CFUs and a decrease in the number of the other progenitors, whereas in hypoxic cultures all types of progenitors decreased. However, as compared with air-incubated controls, all progenitors, except cells sustaining MRACFU-NM, were reduced in hypoxic cultures. The degree of reduction paralleled the position of the progenitor in the hematopoietic hierarchy, being maximum for day-7 CFUs and null for cells sustaining MRACFU-NM, which, in fact, were better preserved in hypoxic cultures.

scholarly journals Mbd3/NuRD is a Key Inhibitory Module During the Induction and Maintenance of Naïve Pluripotency

2015 ◽  
Author(s):  
Asaf Zviran ◽  
Yoach Rais ◽  
Nofar Mor ◽  
Noa Novershtern ◽  
Jacob H Hanna
Keyword(s):  
Pluripotent Stem Cell ◽  
Primordial Germ Cells ◽  
Induced Pluripotent Stem Cell ◽  
Major Pathway ◽  
Serum Replacement ◽  
Epiblast Stem Cells ◽  
Induced Pluripotent ◽  
Knockout Serum Replacement ◽  
Formation Efficiency

Our group has published a study on induced pluripotent stem cell (iPSC) reprogramming (Rais et al. Nature 20131) that reached the following conclusions: a) Mbd3/NuRD is a repressor of inducing naïve pluripotency from mouse Epiblast stem cells (EpiSCs), primordial germ cells (PGCs), murine somatic cells and human secondary fibroblasts; b) Up to 100% iPSC formation efficiency can be achieved via optimized Mbd3/NuRD depletion, in concert with optimized OKSM delivery and naïve pluripotency conditions (2i supplement applied only after 48 hours, human LIF, hypoxia and Vitamin C containing Knockout serum replacement)1. This represented the first proof for deterministic/near-deterministic iPSC reprogramming, and highlighted a previously unappreciated role for Mbd3/NuRD in hampering the re-establishment of pluripotency. Recent reports have seemingly provided contradictory results and attempted to dispute our iPSC efficiency quantifications and/or the role of Mbd3/NuRD in blocking reprogramming2,3. Here we provide a detailed response to these reports based on extended discussions and providing new data. The synthesis presented herein disagrees with claims made by Silva, Hendrich, Bertone and colleagues2,3, and reconfirms that Mbd3/NuRD is a major pathway that inhibits the maintenance and induction of pluripotency1. Further, we foresee that its controlled manipulation is likely to become an integral pathway for inducing and maintaining naïve pluripotency in a variety of species.

scholarly journals The role of interstellar filaments in regulating the star formation efficiency and shaping the initial mass function

2015 ◽  
Vol 11 (S315) ◽  
pp. 81-84
Author(s):  
Vera Könyves ◽  
Philippe André
Keyword(s):  
Star Formation ◽  
Mass Function ◽  
Initial Mass Function ◽  
Filamentary Structure ◽  
Submillimeter Wavelengths ◽  
The Galaxy ◽  
External Galaxies ◽  
Space Observatories ◽  
Formation Efficiency

AbstractRecent surveys at infrared and submillimeter wavelengths with the Spitzer and Herschel space observatories suggest that star formation in dense molecular gas is governed by essentially the same “laws” in nearby Galactic clouds and distant external galaxies. This raises the possibility of a unified picture for star formation in the Universe from individual-cloud scales to galaxy–wide scales. We summarize the star formation scenario favored by Herschel studies of the nearest molecular clouds of the Galaxy which point to the key role of the quasi-universal filamentary structure pervading the cold interstellar medium.

scholarly journals The New Plastic Flow Machining Process for Producing Thin Sheets

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Viet Q. Vu ◽  
Yan Beygelzimer ◽  
Roman Kulagin ◽  
Laszlo S. Toth
Keyword(s):  
Plastic Flow ◽  
Pure Aluminum ◽  
Sheet Thickness ◽  
Machining Process ◽  
Thin Sheets ◽  
Die Geometry ◽  
Average Grain Size ◽  
Formation Efficiency ◽  
Commercial Pure Aluminum

A new severe plastic deformation (SPD) process called plastic flow machining (PFM) was recently proposed to produce thin sheets with gradient structures. In the present paper, the role of the die geometry is investigated by studying the effects of the produced sheet thickness (h) on the material properties of commercial pure Aluminum (Al1050) processed by PFM. The obtained experimental results show that an increase of h in the range of 0.65 to 1.5 mm improved the formation efficiency of the sheet. Microstructures of the produced sheets show gradient structures with an average grain size varying from 0.8 to 3.81 µm across the sheet thickness. Both experiments and finite element (FE) simulations document that the degree of the gradient in the microstructure became more significant when h was increased. Sheets produced by PFM exhibited a better strength-ductility balance than sheets obtained in other SPD processes. Tensile strength of 160–175 MPa and total ductility of 18–25% were obtained for the processed samples after PFM. A rise of h from 0.65 to 1.5 mm lowered the strength but enhanced the ductility of the produced sheet, which is due to the coarser microstructure at larger values of h.

Role of magnesium complexes in the anionic polymerization of hexano-6-lactam

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Petra Arnoldová ◽  
Jiří Brus ◽  
Irena Prokopová ◽  
Jiří Brožek
Keyword(s):  
Anionic Polymerization ◽  
Polymer Chains ◽  
Magnesium Bromide ◽  
Carbonyl Groups ◽  
Magnesium Atom ◽  
Model Compounds ◽  
Magnesium Compounds ◽  
Magnesium Complexes ◽  
Alkali Salts

AbstractThe course of anionic hexano-6-lactam polymerization initiated with magnesium compounds differs in some parameters from that initiated with lactam alkali salts. This may be attributed to the coordination of magnesium compounds with functional groups on polymer chains. Supposed coordination effects were proved on model compounds of N-ethylacetamide and N-butyryl-hexano-6-lactam with magnesium bromide. Based on interpretation of Raman and NMR spectra, the interaction between magnesium bromide and both types of ligands as an electron donating coordination of carbonyl groups was proposed. N-butyryl-hexano-6-lactam is more distinctly coordinated to magnesium atom through the carbonyl group located in the cyclic constitution unit.

Role of F3 color centers in colloid formation process in alkali-halide crystals

1999 ◽  
Vol 42 (11) ◽  
pp. 931-934
Author(s):  
L. I. Shchepina ◽  
V. N. Solomatov ◽  
T. G. Yur'eva
Keyword(s):  
Formation Process ◽  
Alkali Halide ◽  
Color Centers ◽  
Alkali Halide Crystals ◽  
Colloid Formation

Neutral Silicon-Vacancy Color Center in Diamond: Cluster Simulation of Spatial and Hyperfine Characteristics

2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940010 ◽  
Author(s):  
A. L. Pushkarchuk ◽  
S. A. Kuten ◽  
V. A. Pushkarchuk ◽  
A. P. Nizovtsev ◽  
S. Ya. Kilin
Keyword(s):  
Color Center ◽  
Hyperfine Interactions ◽  
Pulse Sequences ◽  
Nitrogen Vacancy ◽  
Color Centers ◽  
Nuclear Spins ◽  
Silicon Vacancy ◽  
Nv Center ◽  
Long Time

One of the most promising platforms to implement quantum technologies are coupled electron-nuclear spins in solids in which electrons can play a role of “fast” qubits, while nuclear spins can store quantum information for a very long time due to their exceptionally high isolation from the environment. The well-known representative of such systems is the “nitrogen-vacancy” (NV) center in diamond coupled by a hyperfine interaction to its intrinsic [Formula: see text]N/[Formula: see text]N nuclear spin or to [Formula: see text]C nuclear spins presenting in the diamond lattice. More recently, other paramagnetic color centers in diamond have been identified exhibiting even better characteristics in comparison to the NV center. Essential prerequisite for a high-fidelity spin manipulation in these systems with tailored control pulse sequences is a complete knowledge of hyperfine interactions. Development of this understanding for one of the new color centers in diamond, viz., neutral “silicon-vacancy” (SiV0) color center, is a primary goal of this paper, in which we are presenting preliminary results of computer simulation of spatial and hyperfine characteristics of SiV0 center in H-terminated clusters C[Formula: see text][SiV0]H[Formula: see text] and C[Formula: see text][SiV0]H[Formula: see text].

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