The Mechanism of Surface-Radical Generation and Amorphization of Crystalline Quartz Sand upon Mechanochemical Grinding

2021 ◽  
Vol 125 (38) ◽  
pp. 20877-20886
Author(s):  
Kapish Gobindlal ◽  
Zoran Zujovic ◽  
Pooja Yadav ◽  
Jonathan Sperry ◽  
Cameron C. Weber
Keyword(s):  
Quartz Sand ◽  
Crystalline Quartz ◽  
Radical Generation

Visible-Light Photosensitized Aryl and Alkyl Decarboxylative Carbon-Heteroatom and Carbon-Carbon Bond Formations

2019 ◽  
Author(s):  
Tuhin Patra ◽  
Satobhisha Mukherjee ◽  
Jiajia Ma ◽  
Felix Strieth-Kalthoff ◽  
Frank Glorius
Keyword(s):  
Energy Transfer ◽  
Visible Light ◽  
Alkyl Radical ◽  
General Strategy ◽  
Alkyl Radicals ◽  
Bond Forming ◽  
Radical Trapping ◽  
Carbon Carbon Bond ◽  
Radical Generation ◽  
Trapping Agent

<sub>A general strategy to access both aryl and alkyl radicals by photosensitized decarboxylation of the corresponding carboxylic acids esters has been developed. An energy transfer mediated homolysis of unsymmetrical sigma-bonds for a concerted fragmentation/decarboxylation process is involved. As a result, an independent aryl/alkyl radical generation step enables a series of key C-X and C-C bond forming reactions by simply changing the radical trapping agent.</sub>

In-vivo anti-oxidant screening of Tectona grandis extract

2020 ◽  
Vol 9 (1) ◽  
pp. 1-4
Author(s):  
Tamilarasi G P ◽  
Sabarees G
Keyword(s):  
Biochemical Parameters ◽  
Tectona Grandis ◽  
The Body ◽  
Altered Expression ◽  
Physiological Conditions ◽  
Synthetic Drugs ◽  
Significant Difference ◽  
Anti Oxidant ◽  
Radical Generation

Oxidation is an essential reaction in the human body, which determines the expression of proteins in the body. This results in the altered expression like rapid growth resulting in cancers and other disorders. Many synthetic drugs are available in the market that is effective in limiting the free radical generation and the reaction of radicals with cells. Unfortunately, all those synthetic drugs were found to cause side effects and adverse effects in the body. But given the accuracy of the predictability of the results and administration, this research focuses on testing the anti-oxidant efficiency in rat models testing the biochemical parameters. Investigations have also been done on the anti-oxidant activity of Tectona, but every research was concentrated to prove the anti-oxidant activity only. extract had been tested for anti-oxidant activity by estimating various tissue parameters and it showed better activity. As predicted, there is a significant difference in the and results which can be explained are due to the physiological conditions that exist inside the body.

SURVEI POTENSI PASIR KUARSA DI DAERAH KETAPANG PROPINSI KALIMANTAN BARAT

2012 ◽  
Vol 11 (2) ◽  
Author(s):  
Teguh Prayogo ◽  
Bayu Budiman
Keyword(s):  
Glass Industry ◽  
Quartz Sand ◽  
Mineral Resources ◽  
Cement Industry ◽  
Laboratory Analysis ◽  
Rock Weathering ◽  
West Kalimantan ◽  
White Sand ◽  
Quartz Sands ◽  
Industrial Mineral

Ketapang area is one of lower part or southern sub-province of West Kalimanatan Province, which is located geographically between 108o40’ and 111o20’ in Longitude and between 0o20’ and 3o04’ in Latitude. This area has various of industrial mineral resources, for example quartz sand. Quartz sand or also calledwith white sand is the reasult of rock weathering that contents main mineral, such as quartz, and felsdpar. Then, the result of weathering is cleaned and transported by water or wind and deposited in the stream side, lake or sea. In this paper will bedescribed concerning to locations, characteristics, and usages of quratz sand in Ketapang area, West Kalimantan Province. Based on chemical or laboratory analysis and interpretation, the quartz sands can be used as glass industry, cement industry material, and moulding industry.

Superoxide Anion Radical: Generation and Detection in Cellular and Non-Cellular Systems

2015 ◽  
Vol 22 (37) ◽  
pp. 4234-4256 ◽  
Author(s):  
Renan Chiste ◽  
Marisa Freitas ◽  
Adriana Mercadante ◽  
Eduarda Fernandes
Keyword(s):  
Superoxide Anion ◽  
Anion Radical ◽  
Cellular Systems ◽  
Superoxide Anion Radical ◽  
Radical Generation

Recent advances in Minisci-type reactions and applications in organic synthesis

2020 ◽  
Vol 24 ◽  
Author(s):  
Wengui Wang ◽  
Shoufeng Wang
Keyword(s):  
Free Radical ◽  
Hydrogen Atom ◽  
Organic Synthesis ◽  
Radical Reactivity ◽  
Atom Loss ◽  
Radical Generation ◽  
In Situ Generation ◽  
Thermal Cleavage ◽  
Synthetic Chemist

Abstract:: Minisci-type reactions have become widely known as reactions that involve the addition of carbon-centered radicals to basic heteroarenes followed by formal hydrogen atom loss. While the originally developed protocols for radical generation remain in active use today, in recent years by a new array of radical generation strategies allow use of a wider variety of radical precursors that often operate under milder and more benign conditions. New transformations based on free radical reactivity are now available to a synthetic chemist looking to utilize a Minisci-type reaction. Radical-generation methods based on photoredox catalysis and electrochemistry, which utilize thermal cleavage or the in situ generation of reactive radical precursors, have become popular approaches. Our review will cover the remarkably literature that has appeared on this topic in recent 5 years, from 2015-01 to 2020-01, in an attempt to provide guidance to the synthetic chemist, on both the challenges that have been overcome and applications in organic synthesis.

An overview on therapeutic potential of Iris Persica

2020 ◽  
Vol 06 ◽  
Author(s):  
Faiq H. S. Hussain ◽  
Hawraz Ibrahim M. Amin ◽  
Dinesh kumar Patel ◽  
Omji Porwal
Keyword(s):  
Therapeutic Potential ◽  
Biological Activities ◽  
Folk Medicine ◽  
Underground Storage ◽  
Kurdistan Region ◽  
Traditional Medicines ◽  
The Family ◽  
Storage Organs ◽  
Radical Generation ◽  
Perennial Herbs

: The family Iridaceae contains 92 genera and more than 1800 species, mostly perennial herbs with underground storage organs called rhizomes (bulbs). Some genera are important in traditional medicines, especially Iris and Gladiolus. The genus Iris belongs to this family and comprises about hundreds species among them, 12 species are found in Iraq. It has been widely used various medicines worldwide especially Iris persica is used in folk medicine in the Kurdistan region of Iraq as an effective treatment against tumours, antibacterial, antifungal and treating inflammation. Earlier finding confirmed that Iris persica and its constituents play role in the scavenging of free radical generation and prevention of disease pathogenesis. Each part of the Iris persica herb has some medicinal property. This review gives a eagle eye view mainly on the biological activities of the Iris persica and some of their compounds isolated, pharmacological actions of the Iris persica extracts and products, and plausible medicinal and therapeutically applications.

scholarly journals A cross-dehydrogenative C(sp3)−H heteroarylation via photo-induced catalytic chlorine radical generation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chia-Yu Huang ◽  
Jianbin Li ◽  
Chao-Jun Li
Keyword(s):  
Hydrogen Atom ◽  
Hydrogen Evolution ◽  
Alkyl Radical ◽  
Cobalt Catalyst ◽  
Alkylation Reaction ◽  
Hydrogen Atom Abstraction ◽  
Dehydrogenative Coupling ◽  
Radical Generation ◽  
Limited Scope

AbstractHydrogen atom abstraction (HAT) from C(sp3)–H bonds of naturally abundant alkanes for alkyl radical generation represents a promising yet underexplored strategy in the alkylation reaction designs since involving stoichiometric oxidants, excessive alkane loading, and limited scope are common drawbacks. Here we report a photo-induced and chemical oxidant-free cross-dehydrogenative coupling (CDC) between alkanes and heteroarenes using catalytic chloride and cobalt catalyst. Couplings of strong C(sp3)–H bond-containing substrates and complex heteroarenes, have been achieved with satisfactory yields. This dual catalytic platform features the in situ engendered chlorine radical for alkyl radical generation and exploits the cobaloxime catalyst to enable the hydrogen evolution for catalytic turnover. The practical value of this protocol was demonstrated by the gram-scale synthesis of alkylated heteroarene with merely 3 equiv. alkane loading.

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