Nematicity in chalcogenide parent compound Fe1+Te probed by thermoelectric measurements

2020 ◽  
Vol 139 ◽  
pp. 109311 ◽  
Author(s):  
Marcin Matusiak ◽  
Anna Krztoń-Maziopa
Keyword(s):  
Parent Compound ◽  
Thermoelectric Measurements

Organic Syntheses During the Impact of a Comet with a Gaseous Planet

1997 ◽  
Vol 161 ◽  
pp. 189-195
Author(s):  
Cesare Guaita ◽  
Roberto Crippa ◽  
Federico Manzini
Keyword(s):  
Polymeric Material ◽  
Molecular Form ◽  
Parent Compound ◽  
Blue Filter ◽  
Organic Syntheses ◽  
The Impact

AbstractA large amount of CO has been detected above many SL9/Jupiter impacts. This gas was never detected before the collision. So, in our opinion, CO was released from a parent compound during the collision. We identify this compound as POM (polyoxymethylene), a formaldehyde (HCHO) polymer that, when suddenly heated, reformes monomeric HCHO. At temperatures higher than 1200°K HCHO cannot exist in molecular form and the most probable result of its decomposition is the formation of CO. At lower temperatures, HCHO can react with NH3 and/or HCN to form high UV-absorbing polymeric material. In our opinion, this kind of material has also to be taken in to account to explain the complex evolution of some SL9 impacts that we observed in CCD images taken with a blue filter.

ANTI-OVULATORY ACTIVITY OF STEROIDS ADMINISTERED BY GAVAGE IN THE ADULT OESTRUS RABBIT

1963 ◽  
Vol 42 (2_Suppl) ◽  
pp. S17-S30
Author(s):  
Fred A. Kind ◽  
Ralph I. Dorfman
Keyword(s):  
Dose Response ◽  
Active Compound ◽  
Subcutaneous Injection ◽  
Response Curve ◽  
Parent Compound ◽  
Dose Response Curve ◽  
Relative Potency ◽  
Reference Standard ◽  
Highly Active ◽  
Dose Levels

ABSTRACT Thirty-seven steroids have been studied as orally effective inhibitors of ovulation in the mated oestrus rabbit. Norethisterone served as the reference standard and a dose response curve was established between the 0.31 and 1.25 mg dose levels. Nine highly active anti-ovulatory compounds are described listed in a decreasing order of potency with norethisterone having the arbitrary value of one: 6-chloro-Δ6-dehydro-17α-acetoxyprogesterone (35), 6α-methyl-Δ1-dehydro-17α-acetoxyprogesterone (≥ 10), 6-fluoro-Δ6-dehydro-17α-acetoxyprogesterone(9), 6-methyl-Δ6-dehydro-17α-acetoxyprogesterone (5), Δ6-dehydro-17α-acetoxyprogesterone (≥ 3), 6α-methyl-17α-acetoxyprogesterone (2.6), 6-chloro-Δ1,6-bisdehydro-17α-acetoxyprogesterone (≥ 2), 2-hydroxymethyl-17α-methyl-17β-hydroxyandrostan-3-one (≥ 2), and 6α-fluoro-16α-methyl-17α-acetoxyprogesterone (≥ 1.25). The anti-ovulatory activity of a compound was not related necessarily to the progestational activity of a compound nor to the anti-gonadotrophic activity as measured in parabiotic rats. 6-Chloro-Δ60dehydro-17-acetoxyprogesterone was as effective by gavage as previously shown by subcutaneous injection. 2-Hydroxymethyl-17α-methyl-17β-hydroxyandrostan-3-one was at least 2.5 times more active by gavage than by injection. While 17α-acetoxyprogesterone was a very weak anti-ovulatory steroid, modifications of the structure by addition of methyl or halogen at the 6α position with or without unsaturation greatly increased the activity. 6-Chloro-Δ6-dehydro-27α-acetoxyprogesterone was the most active compound in this series showing a relative potency of 3500 times that of the parent compound 17α-acetoxyprogesterone.

Solar photocatalysis mediated by ZnO for the removal of last traces of Indigo carmine dye pollutant from water

2018 ◽  
Vol 4 (02) ◽  
Author(s):  
Veena Vijayan ◽  
Suguna Yesodharan ◽  
E. P. Yesodharan
Keyword(s):  
Indigo Carmine ◽  
Parent Compound ◽  
Oxygen Demand ◽  
Green Technology ◽  
Solar Photocatalysis ◽  
Reaction Proceeds ◽  
Transient Intermediates ◽  
Significant Chemical ◽  
Hydroxyl Free Radicals ◽  
Purification Of Water

Solar photocatalysis as a potential green technology for the removal of traces of the dye pollutant Indigo carmine (IC) from water is investigated using ZnO as the catalyst. Degradation/decolorization alone does not result in complete decontamination as seen from the significant Chemical Oxygen Demand (COD) of water even after the parent compound has disappeared completely. The degradation proceeds through many intermediates which also get mineralized eventually but slowly. Oxalic acid is identified as a stable slow mineralizing degradation product which itself is formed from other transient intermediates. Effect of various parameters such as catalyst dosage, concentration of the dye, pH, temperature, presence of contaminant salts etc. on the degradation is investigated and quantified. Oxidants such as S2O82- and H2O2 have only moderate influence on the degradation. The degradation follows variable kinetics depending on the concentration of the substrate. The reaction proceeds very slowly in the absence of O2 indicating the importance of reactive oxygen species and hydroxyl free radicals in photocatalysis. H2O2 formed insitu in the system undergoes concurrent decomposition resulting in stabilization in its concentration. The study demonstrates that solar photocatalysis can be used as a viable tool for the purification of water contaminated with traces of IC.

Crystal Engineering of Bi2WO6 to Polar Aurivillius-Phase Oxyhalides

2019 ◽  
Author(s):  
Kazuki Morita ◽  
Ji-Sang Park ◽  
Sunghyun Kim ◽  
Kenji Yasuoka ◽  
Aron Walsh
Keyword(s):  
Photocatalytic Activity ◽  
Crystal Engineering ◽  
First Principles ◽  
Parent Compound ◽  
Aurivillius Phase ◽  
Aurivillius Phases ◽  
Charge Neutrality ◽  
Bismuth Oxides ◽  
Structure Surface ◽  
Electric Dipoles

The Aurivillius phases of complex bismuth oxides have attracted considerable attention due to their lattice polarization (ferroelectricity) and photocatalytic activity. We report a first-principles exploration of Bi<sub>2</sub>WO<sub>6</sub> and the replacement of W<sup>6+</sup> by pentavalent (Nb<sup>5+</sup>, Ta<sup>5+</sup>) and tetravalent (Ti<sup>4+</sup>, Sn<sup>4+</sup>) ions, with charge neutrality maintained by the formation of a mixed-anion oxyhalide sublattice. We find that Bi<sub>2</sub>SnO<sub>4</sub>F<sub>2</sub> is thermodynamically unstable, in contrast to Bi<sub>2</sub>TaO<sub>5</sub>F, Bi<sub>2</sub>NbO<sub>5</sub>F and Bi<sub>2</sub>TiO<sub>4</sub>F<sub>2</sub>. The electric dipoles introduced by chemical substitutions in the parent compound are found to suppress the spontaneous polarization from 61.55 μC/cm<sup>2</sup> to below 15.50 μC/cm<sup>2</sup>. Analysis of the trends in electronic structure, surface structure, and ionization potentials are reported. This family of materials can be further extended with control of layer thicknesses and choice of compensating halide species.<br>

Changing the Static and Dynamic Lattice Effects for the Improvement of the Ionic Transport Properties Within the Argyrodite Li6PS5-xSexI

2019 ◽  
Author(s):  
Roman Schlem ◽  
Michael Ghidiu ◽  
Sean Culver ◽  
Anna-Lena Hansen ◽  
Wolfgang Zeier
Keyword(s):  
Ionic Conductivity ◽  
Activation Barrier ◽  
Parent Compound ◽  
Ionic Transport ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Effects ◽  
Solid State Batteries ◽  
All Solid State Batteries ◽  
Pulse Echo

<p>The lithium argyrodites Li<sub>6</sub>PS<sub>5</sub>X (X = Cl, Br, I) have been gaining momentum as candidates for electrolytes in all-solid-state batteries. While these materials have been well-characterized structurally, the influences of the static and dynamic lattice properties are not fully understood. Recent improvements to the ionic conductivity of Li<sub>6</sub>PS<sub>5</sub>I (which as a parent compound is a poor ionic conductor) via elemental substitutions have shown that a multitude of influences affect the ionic transport in the lithium argyrodites, and that even poor conductors in this class have room left for improvement.</p><p>Here we explore the influence of isoelectronic substitution of sulfur with selenium in Li<sub>6</sub>PS<sub>5-<i>x</i></sub>Se<i><sub>x</sub></i>I. Using a combination of X-ray diffraction, impedance spectroscopy, Raman spectroscopy, and pulse-echo speed of sound measurements,we explore the influence of the static and dynamic lattice on the ionic transport. The substitution of S<sup>2-</sup>with Se<sup>2- </sup>broadens the diffusion pathways and structural bottlenecks, as well as leading to a softer more polarizable lattice, all of which lower the activation barrier and lead to an increase in the ionic conductivity. This work sheds light on ways to systematically understand and improve the functional properties of this exciting material family. </p>

Confirmation of Long Term Excreted Metabolites of Stanozolol by Gas Chromatography Coupled with High Resolution Mass Spectrometry (GC/HRMS)

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Ileana Vajiala ◽  
Ruxandra Subasu ◽  
Mirela Zorio ◽  
Rodica Picu
Keyword(s):  
High Resolution Mass Spectrometry ◽  
Parent Compound ◽  
Urine Specimen ◽  
Decision Making Process ◽  
Purification Procedure ◽  
Specific Identification ◽  
Immunoaffinity Purification ◽  
In Doping ◽  
Resolution Mass

Upon screening identification of Stanozolol, GC/HRMS confirmation of the suspicious sample is done by reanalysis of the urine specimen, where a specific immunoaffinity purification procedure is used to selectively isolate the long term excreted metabolites of Stanozolol. By meeting the specific identification criteria for more than one metabolite of the same parent compound, additional evidence could be obtained in the decision making process in doping control.

Voltage Gated Sodium Channel Blockers: Synthesis of Mexiletine Analogues and Homologues

2020 ◽  
Vol 27 ◽  
Author(s):  
Alessia Catalano ◽  
Carlo Franchini ◽  
Alessia Carocci
Keyword(s):  
Sodium Channel ◽  
Channel Blocker ◽  
Parent Compound ◽  
Channel Blockers ◽  
Sodium Channel Blocker ◽  
Starting Point ◽  
Channel Blocking ◽  
Blocking Activity ◽  
Synthetic Routes ◽  
Lateral Sclerosis

: Mexiletine is an antiarrhythmic drug belonging to IB class, acting as sodium channel blocker. Besides its well-known activity on arrhythmias, its usefulness in the treatment of myotonia, myotonic distrophy and amyotrophic lateral sclerosis is now widely recognized. Nevertheless, it has been retired from the market in several countries because of its undesired effects. Thus, several papers were reported in the last years about analogues and homologues of mexiletine being endowed with a wider therapeutic ratio and a more selectivity of action. Some of them showed sodium channel blocking activity higher than the parent compound. It is noteworthy that mexiletine is used in therapy as a racemate even though a difference in the activities of the two enantiomers were widely demonstrated, with (–)-(R)-enantiomer being more active: this finding led several research groups to study mexiletine and its analogues and homologues in their optically active forms. This review summarizes the different synthetic routes used to obtain these compounds. They could represent an interesting starting point to new mexiletine-like compounds without common side effects related to the use of mexiletine.

The design, synthesis, pharmacokinetic and pharmacodynamic evaluation of acyloxyalkyl-substituted T705 prodrugs

2019 ◽  
Vol 15 ◽  
Author(s):  
Xingzhou Li ◽  
Tianhong Zhang ◽  
Wu Zhong
Keyword(s):  
Plasma Concentration ◽  
Development Strategy ◽  
Parent Compound ◽  
Systemic Exposure ◽  
Parent Drug ◽  
New Drugs ◽  
Structure Modification ◽  
Design Synthesis ◽  
Pharmacokinetic Properties

Background: The pharmacokinetic properties of T705 are not optimal for the development of new drugs. Objective: To improve the pharmacokinetic properties of T-705, structure modification of T-705 was conducted using a prodrug strategy. Method: The acidic amide H atom (N4-H) of T705 was attempted to be replaced with acyloxyalkyl groups following the prodrugs development strategy for carboxylic acids, and the resulting compounds were investigated whether could work as prodrugs and contribute to improving the pharmacokinetic properties of the parent compound T705 in vivo. Results: 4-acyloxyalkyl-T705 (4a–e), did act as prodrugs in vivo. 4-iso-butyryloxymethyl-T705 (4a) and 4-acetoxymethyl-T705 (4b) could significantly improve the plasma concentration and systemic exposure for T705, compound 4a displayed non inferior anti-influenza activities, compared with its parent drug T705. Conclusion: Our prodrugs development strategy for T705 is feasible, which may serves as a reference to prodrugs development of similar heterocyclic amides compounds.

scholarly journals Effects of Glyphosate-Based and Derived Products on Sea Urchin Larval Development

2020 ◽  
Vol 8 (9) ◽  
pp. 661
Author(s):  
Davide Asnicar ◽  
Costanza Cappelli ◽  
Ahmad Safuan Sallehuddin ◽  
Nur Atiqah Maznan ◽  
Maria Gabriella Marin
Keyword(s):  
Larval Development ◽  
Sea Urchin ◽  
Marine Invertebrates ◽  
Parent Compound ◽  
Paracentrotus Lividus ◽  
Marine Species ◽  
Negative Effects ◽  
Aminomethylphosphonic Acid ◽  
Main Degradation Product ◽  
Herbicide Glyphosate

Despite the widespread use of herbicide glyphosate in cultivation, its extensive runoff into rivers and to coastal areas, and the persistence of this chemical and its main degradation product (aminomethylphosphonic acid, AMPA) in the environment, there is still little information on the potential negative effects of glyphosate, its commercial formulation Roundup® and AMPA on marine species. This study was conducted with the aim of providing a comparative evaluation of the effects of glyphosate-based and its derived chemicals on the larval development of the sea urchin Paracentrotus lividus, thus providing new data to describe the potential ecotoxicity of these contaminants. In particular, the effects on larval development, growth and metabolism were assessed during 48 h of exposure from the time of egg fertilization. The results confirm that AMPA and its parent compound, glyphosate have similar toxicity, as observed in other marine invertebrates. However, interestingly, the Roundup® formulation seemed to be less toxic than the glyphosate alone.

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