A Computational Approach to Understand the Role of Metals and Axial Ligands in Artificial Heme Enzymes Catalyzed C-H Insertion

2021 ◽  
Author(s):  
Reena Balhara ◽  
Ritwika Chatterjee ◽  
Garima Jindal
Keyword(s):  
Computational Approach ◽  
Cytochrome P450s ◽  
Heme Enzymes ◽  
Axial Ligands ◽  
Naturally Occurring

Engineered heme enzymes such as myoglobin and cytochrome P450s metalloproteins are gaining widespread importance due to their efficiency in catalyzing non-natural reactions. In a recent strategy, the naturally occurring Fe...

Fine structure and properties of defects in naturally occurring silicates and oxides

1990 ◽  
Vol 48 (4) ◽  
pp. 460-461
Author(s):  
David R. Veblen
Keyword(s):  
Chemical Reactions ◽  
High Resolution Electron Microscopy ◽  
Extended Defects ◽  
Single Chain ◽  
Naturally Occurring ◽  
Resolution Electron ◽  
Fine Structures ◽  
Image Simulations ◽  
Similar Crystal Structure

Extended defects and interfaces control many processes in rock-forming minerals, from chemical reactions to rock deformation. In many cases, it is not the average structure of a defect or interface that is most important, but rather the structure of defect terminations or offsets in an interface. One of the major thrusts of high-resolution electron microscopy in the earth sciences has been to identify the role of defect fine structures in reactions and to determine the structures of such features. This paper will review studies using HREM and image simulations to determine the structures of defects in silicate and oxide minerals and present several examples of the role of defects in mineral chemical reactions. In some cases, the geological occurrence can be used to constrain the diffusional properties of defects.The simplest reactions in minerals involve exsolution (precipitation) of one mineral from another with a similar crystal structure, and pyroxenes (single-chain silicates) provide a good example. Although conventional TEM studies have led to a basic understanding of this sort of phase separation in pyroxenes via spinodal decomposition or nucleation and growth, HREM has provided a much more detailed appreciation of the processes involved.

Role of Flavonoids in Neurodegenerative Disorders with Special Emphasis on Tangeritin

2019 ◽  
Vol 18 (8) ◽  
pp. 581-597 ◽  
Author(s):  
Ambreen Fatima ◽  
Yasir Hasan Siddique
Keyword(s):  
Medicinal Plants ◽  
Mechanism Of Action ◽  
Neurodegenerative Disorders ◽  
Treatment Strategies ◽  
Dietary Supplementation ◽  
Plant Polyphenols ◽  
Promising Candidate ◽  
Naturally Occurring ◽  
The Brain

Flavonoids are naturally occurring plant polyphenols found universally in all fruits, vegetables and medicinal plants. They have emerged as a promising candidate in the formulation of treatment strategies for various neurodegenerative disorders. The use of flavonoid rich plant extracts and food in dietary supplementation have shown favourable outcomes. The present review describes the types, properties and metabolism of flavonoids. Neuroprotective role of various flavonoids and the possible mechanism of action in the brain against the neurodegeneration have been described in detail with special emphasis on the tangeritin.

Monosodium Glutamate Toxicity and the Possible Protective Role of L–Carnitine

2018 ◽  
Vol 6 (1) ◽  
pp. 45-56
Author(s):  
Lalrinzuali Sailo ◽  
◽  
Meesala Krishna Murthy ◽  
Khandayataray Pratima ◽  
Vikas Kumar Roy ◽  
...  
Keyword(s):  
Human Subjects ◽  
Monosodium Glutamate ◽  
Essential Amino Acids ◽  
Protective Role ◽  
Glutamate Toxicity ◽  
Common Salt ◽  
Genotoxic Effects ◽  
Naturally Occurring ◽  
Flavour Enhancer

Monosodium glutamate is naturally available non-essential amino acids, which found in naturally occurring foods and used as flavour enhancer worldwide. Monosodium glutamate is believed to be linked with diverse health problems. The aim of the study was toxic effects of monosodium glutamate (MSG) and the protective role of L-carnitine, light on the available literature from last 25 years about diverse toxicity studies which had been carried out on animal and human models. Google scholar, NCBI, PUBMED, EMBASE, Wangfang databases, and Web of Science databases were used to retrieve the available studies. MSG was linked with deleterious effects particularly in animals including induction of obesity, diabetes, hepatotoxic, neurotoxic and genotoxic effects showed in Literature. Few reports revealed increased hunger, food intake, and obesity in human subjects due to MSG consumption. Hepatotoxic, neurotoxic, and genotoxic effects of monosodium glutamate on humans carried out very limitedly. High consumption of monosodium glutamate may be linked with harmful health effects showed in available literatures. So, it is recommended to use common salt instead of MSG. Furthermore, intensive research is required to explore monosodium glutamate–related molecular and metabolic mechanisms. L-carnitine can protect from Hepatotoxic, neurotoxic, renal impairment and genotoxic effects functionally, biochemically and histopathologically with a corresponding reduction of oxidative stress.

How Artefacts Do Leadership: A Ventriloquial Analysis

2021 ◽  
pp. 089331892199807
Author(s):  
Jonathan Clifton ◽  
Fernando Fachin ◽  
François Cooren
Keyword(s):  
Organizational Communication ◽  
Recent Work ◽  
Distributed Leadership ◽  
Network Theory ◽  
Actor Network Theory ◽  
Fine Grained ◽  
Naturally Occurring ◽  
Human Actors

To date there has been little work that uses fine-grained interactional analyses of the in situ doing of leadership to make visible the role of non-human as well as human actants in this process. Using transcripts of naturally-occurring interaction as data, this study seeks to show how leadership is co-achieved by artefacts as an in-situ accomplishment. To do this we situate this study within recent work on distributed leadership and argue that it is not only distributed across human actors, but also across networks that include both human and non-human actors. Taking a discursive approach to leadership, we draw on Actor Network Theory and adopt a ventriloquial approach to sociomateriality as inspired by the Montreal School of organizational communication. Findings indicate that artefacts “do” leadership when a hybrid presence is made relevant to the interaction and when this presence provides authoritative grounds for influencing others to achieve the group’s goals.

scholarly journals Selenium and Dogs: A Systematic Review

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 418
Author(s):  
Viola Zentrichová ◽  
Alena Pechová ◽  
Simona Kovaříková
Keyword(s):  
Male Fertility ◽  
Clinical Signs ◽  
Complex Data ◽  
Selenium Status ◽  
Dog Food ◽  
Balanced Diet ◽  
Naturally Occurring ◽  
Correct Function ◽  
Indirect Assay

The intent of this review is to summarize the knowledge about selenium and its function in a dog’s body. For this purpose, systematic literature search was conducted. For mammals, including dogs, a balanced diet and sufficient intake of selenium are important for correct function of metabolism. As for selenium poisoning, there are no naturally occurring cases known. Nowadays, we do not encounter clinical signs of its deficiency either, but it can be subclinical. For now, the most reliable method of assessing selenium status of a dog is measuring serum or plasma levels. Levels in full blood can be measured too, but there are no reference values. The use of glutathione peroxidase as an indirect assay is questionable in canines. Commercial dog food manufactures follow recommendations for minimal and maximal selenium levels and so dogs fed commercial diets should have balanced intake of selenium. For dogs fed home-made diets, complex data are missing. However, subclinical deficiency seems to affect, for example, male fertility or recovery from parasitical diseases. Very interesting is the role of selenium in prevention and treatment of cancer.

scholarly journals Arsenic Removal by Advanced Electrocoagulation Processes: The Role of Oxidants Generated and Kinetic Modeling

Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 928
Author(s):  
Micah Flor V. Montefalcon ◽  
Meliton R. Chiong ◽  
Augustus C. Resurreccion ◽  
Sergi Garcia-Segura ◽  
Joey D. Ocon
Keyword(s):  
Kinetic Modeling ◽  
Arsenic Removal ◽  
Fold Increase ◽  
Electrochemical Treatment ◽  
Promising Alternative ◽  
Iron Electrodes ◽  
Removal Capacity ◽  
Naturally Occurring ◽  
Treatment Technologies

Arsenic (As) is a naturally occurring element in the environment that poses significant risks to human health. Several treatment technologies have been successfully used in the treatment of As-contaminated waters. However, limited literature has explored advanced electrocoagulation (EC) processes for As removal. The present study evaluates the As removal performance of electrocoagulation, electrochemical peroxidation (ECP), and photo-assisted electrochemical peroxidation (PECP) technologies at circumneutral pH using electroactive iron electrodes. The influence of As speciation and the role of oxidants in As removal were investigated. We have identified the ECP process to be a promising alternative for the conventional EC with around 4-fold increase in arsenic removal capacity at a competitive cost of 0.0060 $/m3. Results also indicated that the rate of As(III) oxidation at the outset of electrochemical treatment dictates the extent of As removal. Both ECP and PECP processes reached greater than 96% As(III) conversion at 1 C/L and achieved 86% and 96% As removal at 5 C/L, respectively. Finally, the mechanism of As(III) oxidation was evaluated, and results showed that Fe(IV) is the intermediate oxidant generated in advanced EC processes, and the contribution of •OH brought by UV irradiation is insignificant.

scholarly journals Phosphate removal from water by naturally occurring shale, sandstone, and laterite: The role of iron oxides and of soluble species

2019 ◽  
Vol 351 (1) ◽  
pp. 37-47 ◽  
Author(s):  
Dan Eude Kpannieu ◽  
Martine Mallet ◽  
Lacina Coulibaly ◽  
Mustapha Abdelmoula ◽  
Christian Ruby
Keyword(s):  
Iron Oxides ◽  
Phosphate Removal ◽  
Naturally Occurring ◽  
Soluble Species

scholarly journals Anti-Carcinogenic Glucosinolates in Cruciferous Vegetables and Their Antagonistic Effects on Prevention of Cancers

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2983 ◽  
Author(s):  
Prabhakaran Soundararajan ◽  
Jung Kim
Keyword(s):  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
Side Chain ◽  
Cruciferous Vegetables ◽  
Related Factor ◽  
Nuclear Factor ◽  
Naturally Occurring ◽  
Therapeutic Properties ◽  
Responsive Element

Glucosinolates (GSL) are naturally occurring β-d-thioglucosides found across the cruciferous vegetables. Core structure formation and side-chain modifications lead to the synthesis of more than 200 types of GSLs in Brassicaceae. Isothiocyanates (ITCs) are chemoprotectives produced as the hydrolyzed product of GSLs by enzyme myrosinase. Benzyl isothiocyanate (BITC), phenethyl isothiocyanate (PEITC) and sulforaphane ([1-isothioyanato-4-(methyl-sulfinyl) butane], SFN) are potential ITCs with efficient therapeutic properties. Beneficial role of BITC, PEITC and SFN was widely studied against various cancers such as breast, brain, blood, bone, colon, gastric, liver, lung, oral, pancreatic, prostate and so forth. Nuclear factor-erythroid 2-related factor-2 (Nrf2) is a key transcription factor limits the tumor progression. Induction of ARE (antioxidant responsive element) and ROS (reactive oxygen species) mediated pathway by Nrf2 controls the activity of nuclear factor-kappaB (NF-κB). NF-κB has a double edged role in the immune system. NF-κB induced during inflammatory is essential for an acute immune process. Meanwhile, hyper activation of NF-κB transcription factors was witnessed in the tumor cells. Antagonistic activity of BITC, PEITC and SFN against cancer was related with the direct/indirect interaction with Nrf2 and NF-κB protein. All three ITCs able to disrupts Nrf2-Keap1 complex and translocate Nrf2 into the nucleus. BITC have the affinity to inhibit the NF-κB than SFN due to the presence of additional benzyl structure. This review will give the overview on chemo preventive of ITCs against several types of cancer cell lines. We have also discussed the molecular interaction(s) of the antagonistic effect of BITC, PEITC and SFN with Nrf2 and NF-κB to prevent cancer.

Restrictiveness, exclusivity, adversativity, and mirativity

2013 ◽  
Vol 4 (2) ◽  
pp. 181-228 ◽  
Author(s):  
Yu-Fang Wang ◽  
Mei-Chi Tsai ◽  
Wayne Schams ◽  
Chi-Ming Yang
Keyword(s):  
Conversation Analysis ◽  
Mandarin Chinese ◽  
Discourse Marker ◽  
Spoken Discourse ◽  
Interactional Linguistics ◽  
English Only ◽  
Naturally Occurring ◽  
Turn Taking

Mandarin Chinese zhishi (similar to English ‘only’), comprised of the adverb zhi and the copula shi, can act as an adverb (ADV) or a discourse marker (DM). This study analyzes the role of zhishi in spoken discourse, based on the methodological and theoretical principles of interactional linguistics and conversation analysis. The corpus used in this study consists of three sets of data: 1) naturally-occurring daily conversations; 2) radio/TV interviews; and 3) TV panel discussions on current political affairs. As a whole, this study reveals that the notions of restrictiveness, exclusivity, and adversativity are closely associated with ADV zhishi and DM zhishi. In addition, the present data show that since zhishi is often used to express a ‘less than expected’ feeling, it can be used to indicate mirativity (i.e. language indicating that an utterance conveys the speaker’s surprise). The data also show that the distribution of zhishi as an adverb or discourse marker depends on turn taking systems and speech situations in spoken discourse. Specifically, the ADV zhishi tends to occur in radio/TV interviews and TV panel news discussions, while the DM zhishi occurs more often in casual conversations.

The Role of Equatorial and Axial Ligands in Promoting the Activity of Non-Heme Oxidoiron(IV) Catalysts in Alkane Hydroxylation

2007 ◽  
Vol 2007 (19) ◽  
pp. 3023-3033 ◽  
Author(s):  
Leonardo Bernasconi ◽  
Manuel J. Louwerse ◽  
Evert Jan Baerends
Keyword(s):  
Axial Ligands ◽  
Alkane Hydroxylation
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