Free-radical-induced elimination of hydrogen sulfide from dithiothreitol. A chain reaction

1986 ◽  
Vol 108 (12) ◽  
pp. 3542-3544 ◽  
Author(s):  
M. Shahid. Akhlaq ◽  
Clemens. Von Sonntag
Keyword(s):  
Hydrogen Sulfide ◽  
Free Radical ◽  
Chain Reaction ◽  
A Chain

Absolute rate constants for hydrocarbon autoxidation. 33. A product study of the self-reaction of α-tetralylperoxyls in solution

1983 ◽  
Vol 61 (9) ◽  
pp. 2037-2043 ◽  
Author(s):  
A. Baignée ◽  
J. H. B. Chenier ◽  
J. A. Howard
Keyword(s):  
Steady State ◽  
Free Radical ◽  
Rate Constant ◽  
Rate Constants ◽  
The Self ◽  
Absolute Rate ◽  
Chain Reaction ◽  
Low Concentrations ◽  
A Chain ◽  
Product Study

The major initial products of the self-reaction of α-tetralylperoxyls (C10H11O2•) in chlorobenzene at 303–353 K are equal concentrations of α-tetralol and α-tetralone in ~90% yield based on the number of initiating radicals. These yields are consistent with the non-radical (Russell) mechanism for self-reaction. Low concentrations of bis(α-tetralyl) peroxide are produced, indicating that there is a small but detectable free-radical contribution towards termination. C10H11O2• undergoes β-scission in this temperature range but steady-state concentrations of C10H11• are too low to influence the termination rate constant 2kt, or react with C10H11O2• to give (C10H11O2. α-Tetralol to α-tetralone ratios and total yields of these products are significantly less than 1 and 100%, respectively, in methanol and acetonitrile. Formaldehyde is produced in methanol indicating the involvement of α-hydroxymethylperoxyls, derived from the solvent, in termination. There is no evidence for a chain reaction or a zwitterion intermediate for self-reaction of C10H11O2• in solution.

Homogeneous Polymerization of Butadiene Catalyzed by Rhodium Salts

1967 ◽  
Vol 40 (2) ◽  
pp. 602-613
Author(s):  
C. E. H. Bawn ◽  
D. G. T. Cooper ◽  
A. M. North
Keyword(s):  
Free Radical ◽  
Active Species ◽  
Solution Polymerization ◽  
Chain Reaction ◽  
Hydride Shift ◽  
Ligand Displacement ◽  
A Chain ◽  
Organic Amines ◽  
Homogeneous Polymerization ◽  
Protonic Acids

Abstract A study has been made of the solution polymerization of butadiene, to predominantly trans 1, 4 polymer, catalysed by rhodium salts. The reaction is accelerated by protonic acids (including water) and by those reducing agents which in aqueous systems would be capable of reducing RhIII to RhI. Ligands such as organic amines, and also bromide and iodide anions, tend to retard or even inhibit the reaction. The overall process appears to be a chain reaction, but is not free radical in character. The mechanism which best fits all the observations is one in which the active species is a π-allylic rhodium hydride, initiation occurring by hydride shift and propagation occurring by a ligand displacement process.

Free-Radical Reductions of Arenediazonium Ions in Aqueous Solution. VI. On Iododediazoniation

1985 ◽  
Vol 38 (6) ◽  
pp. 991 ◽  
Author(s):  
JE Packer ◽  
RER Taylor
Keyword(s):  
Aqueous Solution ◽  
Free Radical ◽  
Aqueous Solutions ◽  
Major Product ◽  
Chain Reaction ◽  
Γ Irradiation ◽  
A Chain

γ-Irradiation of aqueous solutions of p-ClC6H4N2+BF4- and KI initiates a chain reaction in which dichloroazobenzene is the major product. When iodine is also present the chain reaction is longer and the major product is chloroiodobenzene . The reaction � ������������������������� I2-·+ArN2+ → I2+Ar·+N2 is suggested to be propagation step in both reactions, with Ar · reacting with I3- in the presence of iodine and with ArN2+ in its absence. The relevance of these reactions to iododediazoniation is discussed.

IRRADIATION OF AQUEOUS CHLORAL HYDRATE SOLUTIONS WITH Co60 GAMMA-RAYS: AVERAGE LIFETIME OF THE FREE RADICAL CHAINS

1954 ◽  
Vol 32 (3) ◽  
pp. 322-326 ◽  
Author(s):  
G. R. Freeman ◽  
A. B. Van Cleave ◽  
J. W. T. Spinks
Keyword(s):  
Free Radical ◽  
Hydrochloric Acid ◽  
Gamma Rays ◽  
Chloral Hydrate ◽  
Average Lifetime ◽  
X Rays ◽  
Chain Reaction ◽  
Radical Chain ◽  
A Chain ◽  
Co60 Gamma

When aqueous one molar chloral hydrate solutions are irradiated with X rays or gamma-rays, hydrochloric acid is produced. The reaction appears to be a chain reaction. The average free radical chain lifetime, as determined using a rotating sector, is approximately 0.1 sec.

Observations on a Relationship between Steroid Metabolism and the Concentration of Plasma Fibrinogen

1963 ◽  
Vol 10 (02) ◽  
pp. 400-405 ◽  
Author(s):  
B. A Amundson ◽  
L. O Pilgeram
Keyword(s):  
Blood Coagulation ◽  
Methyl Ether ◽  
Broad Spectrum ◽  
Human Subjects ◽  
Plasma Fibrinogen ◽  
Steroid Metabolism ◽  
Specific Site ◽  
Chain Reaction ◽  
Normal Human ◽  
A Chain

SummaryEnovid (5 mg norethynodrel and 0.075 mg ethynylestradiol-3-methyl ether) therapy in young normal human subjects causes an increase in plasma fibrinogen of 32.4% (P >C 0.001). Consideration of this effect together with other effects of Enovid on the activity of specific blood coagulatory factors suggests that the steroids are exerting their effect at a specific site of the blood coagulation and/or fibrinolytic system. The broad spectrum of changes which are induced by the steroids may be attributed to a combination of a chain reaction and feed-back control.

scholarly journals Pathogenesis and Management of COVID-19

2021 ◽  
Vol 11 (2) ◽  
pp. 77-93
Author(s):  
Khalid O. Alfarouk ◽  
Sari T. S. AlHoufie ◽  
Samrein B. M. Ahmed ◽  
Mona Shabana ◽  
Ahmed Ahmed ◽  
...  
Keyword(s):  
Multiple Organ Failure ◽  
Human Body ◽  
Inflammatory Mediators ◽  
Expression Patterns ◽  
Multiple Organ ◽  
Cytokine Storm ◽  
Chain Reaction ◽  
Road Map ◽  
A Chain ◽  
Global War

COVID-19, occurring due to SARS-COV-2 infection, is the most recent pandemic disease that has led to three million deaths at the time of writing. A great deal of effort has been directed towards altering the virus trajectory and/or managing the interactions of the virus with its subsequent targets in the human body; these interactions can lead to a chain reaction-like state manifested by a cytokine storm and progress to multiple organ failure. During cytokine storms the ratio of pro-inflammatory to anti-inflammatory mediators is generally increased, which contributes to the instigation of hyper-inflammation and confers advantages to the virus. Because cytokine expression patterns fluctuate from one person to another and even within the same person from one time to another, we suggest a road map of COVID-19 management using an individual approach instead of focusing on the blockbuster process (one treatment for most people, if not all). Here, we highlight the biology of the virus, study the interaction between the virus and humans, and present potential pharmacological and non-pharmacological modulators that might contribute to the global war against SARS-COV-2. We suggest an algorithmic roadmap to manage COVID-19.

Thermo-sensitivity of hybrid nanogels for specific endogenous hydrogen sulfide detection and efficient flash chill treatment

2021 ◽  
Author(s):  
Xu-hao Sun ◽  
Qiu-bo Wang ◽  
Li Pan ◽  
Yilin Mu ◽  
Xian Zhang ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Free Radical ◽  
Precipitation Method ◽  
Carboxyl Group ◽  
One Pot ◽  
Thermo Sensitivity

Thermo-responsive nanogels, Poly (NIPAM-AAM) were prepared by a facile method of free radical one-pot precipitation method based on monomeric N-isopropylacrylamide (NIPAM). At the same time, the surface carboxyl group-modified fluorescent...

Influence of initiation mode on stability and control of a chain reaction

1980 ◽  
Vol 20 (18) ◽  
pp. 1197-1204 ◽  
Author(s):  
H. T. Chen ◽  
P. A. Chartier ◽  
S. Setthachayanon
Keyword(s):  
Chain Reaction ◽  
Stability And Control ◽  
A Chain ◽  
And Control

The reaction of thionitrites with barton esters: a convenient free radical chain reaction for decarboxylative nitrosation

Tetrahedron ◽  
1999 ◽  
Vol 55 (12) ◽  
pp. 3573-3584 ◽  
Author(s):  
Pierre Girard ◽  
Nadine Guillot ◽  
William B. Motherwell ◽  
Robyn S. Hay-Motherwell ◽  
Pierre Potier
Keyword(s):  
Free Radical ◽  
Chain Reaction ◽  
Radical Chain ◽  
Free Radical Chain Reaction ◽  
Radical Chain Reaction
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