Studies on the interaction of selenite and selenium with sulfur donors. Part 3. Sulfite

1995 ◽  
Vol 73 (5) ◽  
pp. 716-724 ◽  
Author(s):  
Sheila Ball ◽  
John Milne
Keyword(s):  
Raman Spectroscopy ◽  
Aqueous Solutions ◽  
Nmr Spectra ◽  
Formation Constants ◽  
The Other ◽  
Elemental Selenium ◽  
Ambient Temperatures ◽  
Selenous Acid ◽  
First Time ◽  
Sulfite Solution

Elemental selenium dissolves in sulfite solution to form selenosulfate ion: Se + SO32− = SeSO32−.The formation constants for this equilibrium at temperatures from 0 to 35 °C are reported for the first time. The isomeric thioselenate anion, SSeO32−, is not, however, produced by the reaction of sulfur with selenite nor is the selenoselenate ion, Se2O32−, formed from selenium and selenite. Selenotrithionate is formed rapidly from the reaction of selenous acid with sulfite and hydrogen sulfite according to: HSeO3− + 3 HSO3− = Se(SO3)22− + SO42− + 2H2O.Two isomers of the selenotrithionate ion are observed by Se-77 NMR and Raman spectroscopy, one with O-bonded Se, Se(OSO2)22−, and the other with S-bonded Se, Se(SO3)22−. Both isomers are formed in reactions with hydrogen sulfite but only the O-bonded isomer is formed in sulfite solutions at ambient temperatures. The Raman and Se-77 NMR spectra of the various sulphur–selenium anions formed are given and the parallel with the reactions of selenous acid and thiols is discussed. Keywords: selenium, sulfite, selenosulfate, selenotrithionate, Se-77 NMR, Raman spectroscopy, equilibria, aqueous solutions.

Studies on the interaction of selenite and selenium with sulphur donors. Part 2. A kinetic study of the reaction with 2-mercaptoethanol

1994 ◽  
Vol 72 (12) ◽  
pp. 2506-2515 ◽  
Author(s):  
Wimal Amaratunga ◽  
John Milne
Keyword(s):  
Reaction Mechanism ◽  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Nucleophilic Attack ◽  
Elemental Selenium ◽  
Sulfinic Acid ◽  
Reaction Stage ◽  
Second Stage ◽  
Selenous Acid ◽  
Two Stages

Selenous acid is reduced by 2-mercaptoethanol in water to elemental selenium in two stages.[Formula: see text]The reactions have been followed by spectrophotometry and by proton and 77Se NMR spectroscopy. The mechanism of the first stage parallels that proposed for butyl thiols in 60% dioxane but nucleophilic attack by RS− rather than RSH on the Se(IV) intermediate, RSSeO2−, is of greater significance for 2-mercaptoethanol than for n-butylthiol. The signals of three intermediates are observed in the Se-77 NMR spectra of a mixture undergoing the first reaction stage. These arise from, HOC2H4SSeO2−, (HOC2H4S)2SeO, and an asymmetric intermediate that chemical shift evidence suggests is the sulfinic acid ester, HOC2H4S(O)SeSC2H4OH. The second stage involves coordination of the bis(thio)selenide by thiolate followed by decomposition to disulfide and selenium. Evidence is presented to support a reaction mechanism involving nucleophilic attack exclusively at Se(II) and not at S(II) as suggested in previous work. This stage is strongly accelerated at basic pH and, at pH 8.3 and above, both the first and second stages can take place simultaneously.

CONTRIBUTION TO THE STUDY OF 1,1-DIPHENYLINDAN AND ITS DERIVATIVES. SYNTHESIS OF 1,1-DIPHENYL-3-INDANACETIC AND 1,1-DIPHENYL-3-INDENEACETIC ACIDS

1944 ◽  
Vol 22b (2) ◽  
pp. 32-44
Author(s):  
Paul E. Gagnon ◽  
L. Gravel ◽  
Louis-Philippe Amiot
Keyword(s):  
Aqueous Solutions ◽  
Potassium Carbonate ◽  
Silver Salt ◽  
The Other ◽  
Reformatsky Reaction ◽  
New Methods ◽  
Sodium Ethyl ◽  
Ethyl Malonate ◽  
First Time ◽  
Derivatives Of

1,1-Diphenylindan was treated with one molecule of bromine. It yielded a monobromide, which was condensed with methyl and ethyl alcohols, piperidine, p-toluidine, and aniline. With aqueous solutions of potassium carbonate, the monobromide directly gave rise to 1,1-diphenylindene and small quantities of diphenylindanyl ether.The condensation of the monobromide with sodium ethyl malonate yielded ethyl 1,1-diphenyl-3-indanmalonate from which 1,1-diphenyl-3-indanmalonic and 1-1-diphenyl-3-indanacetic acids were prepared. A few derivatives of these acids were also obtained.To establish the constitution of 1,1-diphenyl-3-indanacetic acid and, hence, that of the monobromide and of the other compounds, this acid was prepared directly from 3,3-diphenyl-1-indanone by a Reformatsky reaction with ethyl bromoacetate.The method of preparation of 1,1-diphenylindan has been improved, 1,1-diphenylindene has been obtained by new methods, and the following compounds are described, as far as the authors are aware, for the first time: 3-bromo-1,1-diphenylindan, 3-methoxy-1,1-diphenylindan, 3-ethoxy-1,1-diphenylindan, 3-N-piperidyl-1,1-diphenylindan, N-phenyl-1,1-diphenyl-3-indanamine, N-p-tolyl-1,1-diphenyl-3-indanamine, ethyl 1,1-diphenyl-3-indanmalonate, 1,1-diphenyl-3-indanmalonic acid, 1,1-diphenyl-3-indanmalonic acid p-nitrobenzyl ester, silver salt of 1,1-diphenyl-3-indanmalonic acid, 1,1-diphenyl-3-indanacetic acid, 1,1-diphenyl-3-indanacetic acid p-nitrobenzyl ester, silver salt of 1,1-diphenyl-3-indanacetic acid, 1,1-diphenyl-3-indanacetanilide, 1,1-diphenyl-3-indanacetamide, 1,1-diphenyl-3-indanacetonitrile, 1,1-diphenyl-3-indanethylamine hydrochloride, ethyl 3-hydroxy-1,1-diphenyl-3-indanacetate, ethyl 1,1-diphenyl-3-indeneacetate, 1,1-diphenyl-3-indeneacetic acid, silver salt of 1,1-diphenyl-3-indeneacetic acid, 1,1-diphenyl-3-indeneacetic acid p-nitrobenzyl ester, ethyl 1,1-diphenyl-3-indanacetate.

Studies on the interaction of selenite and selenium with sulphur donors. Part 5. Thiocyanate

1996 ◽  
Vol 74 (10) ◽  
pp. 1889-1895 ◽  
Author(s):  
Christopher Milne ◽  
John Milne
Keyword(s):  
Raman Spectroscopy ◽  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Chemical Exchange ◽  
Acid Oxidation ◽  
Relaxation Processes ◽  
Line Broadening ◽  
Linkage Isomerism ◽  
Selenous Acid ◽  
Scalar Relaxation

The oxidation of thiocyanic acid by selenous acid has been shown to take place in an analogous way to that found for selenous acid oxidation of most thiols and thiolates to give the corresponding selenotrisulfide and disulfide products[Formula: see text]The products of this reaction have been studied by IR, Raman, and Se-77, C-13, and N-15 NMR spectroscopy. The vibrational spectra of the solid Se(SCN)2 have been assigned based on S-bonded thiocyanate ligands and, through NMR and vibrational spectroscopy, both this linkage isomer and the isomer with N- and S-bonded thiocyanate have been identified and characterized in solutions of Se(SCN)2. A complex combination of scalar relaxation processes, involving chemical exchange and quadrupolar effects, accounts for the line broadening observed in the carbon-13 NMR spectra. Key words: selenite, thiocyanate, selenium dithiocyanate, Se-77, N-15, and C-13 NMR; Raman spectroscopy; linkage isomerism

scholarly journals SOME GLYCOSIDES ISOLATED FROM DESMODIUM GANGETICUM (L.) DC. OF VIET NAM

2018 ◽  
Vol 56 (2A) ◽  
pp. 99-103
Author(s):  
Le Minh Ha
Keyword(s):  
Nmr Spectra ◽  
Protocatechuic Acid ◽  
Methanol Extract ◽  
2D Nmr ◽  
The Other ◽  
Viet Nam ◽  
2D Nmr Spectra ◽  
First Time

From the methanol extract of the leaves of Desmodium gangeticum collected in Me Linh, Ha Noi, we isolated 5 compounds. In which, there are four glycosides including (6S,9R)-roseoside (1), kaempferol-3-O-rutinoside (nicotiflorin) (2),  quercetin-3-O-rutinoside (rutin) (3), β-sitosterol-3-O- β-D-glucopyranoside (4), and the other is protocatechuic acid (5). Kaempferol-3-O-rutinoside (2) was isolated from Desmodium gangeticum for the first time while (6S,9R)-roseoside (1) was isolated from the genus Desmodium for the first time. Their structures were determined by 1D and 2D NMR spectra.

scholarly journals One-Stop Method to Measure Multiple Cardiac Performance Endpoints in Daphnia and Zebrafish by Kymograph

2020 ◽  
Author(s):  
Kevin Adi Kurnia ◽  
Ferry Saputra ◽  
Marri Jmelou M. Roldan ◽  
Agnes L. Castillo ◽  
Jong-Chin Huang ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Animal Models ◽  
High Accuracy ◽  
Cardiac Performance ◽  
The Other ◽  
Cardiovascular Research ◽  
Ambient Temperatures ◽  
One Stop ◽  
First Time

Cardiovascular disease (CVD) is the number one cause of death worldwide. This condition resulted in huge research on CVD increasing the need for animal models suitable for the in vivo research. Daphnia and Zebrafish are good animal models for cardiovascular research due to their relative body transparency and easy culture property. Several methods have been developed to conduct cardiac performance measurement in Daphnia and Zebrafish. However, most of the methods only able to obtain heartbeat rate. The other important cardiac endpoints like stroke volume, ejection fraction, fraction shortening, cardiac output and heartbeat regularity must use other programs for measurement. To overcome this limitation, in this study, we successfully developed a one-stop ImageJ-based method using kymograph macros language that able to obtain multiple cardiac performance endpoints simultaneously for the first time. To validate its utility, we incubate Daphnia magna at different ambient temperatures and exposed zebrafish with astemizole to detect the corresponding cardiac performance alterations. In summary, the kymograph method reported in this study provides a new, easy to use, and inexpensive one-stop method on obtaining multiple cardiac performance endpoints with high accuracy and convenience.

scholarly journals Measurement of Multiple Cardiac Performance Endpoints in Daphnia and Zebrafish by Kymograph

Inventions ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 8
Author(s):  
Kevin Adi Kurnia ◽  
Ferry Saputra ◽  
Marri Jmelou M. Roldan ◽  
Agnes L. Castillo ◽  
Jong-Chin Huang ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Animal Models ◽  
High Accuracy ◽  
Cardiac Performance ◽  
The Other ◽  
Cardiovascular Research ◽  
Ambient Temperatures ◽  
One Stop ◽  
First Time

Cardiovascular disease (CVD) is the number one cause of death worldwide. This condition resulted in huge research on CVD increasing the need for animal models suitable for in vivo research. Daphnia and zebrafish are good animal models for cardiovascular research due to their relative body transparency and easy culture property. Several methods have been developed to conduct cardiac performance measurement in Daphnia and zebrafish. However, most of the methods are only able to obtain heartbeat rate. The other important cardiac endpoints like stroke volume, ejection fraction, fraction shortening, cardiac output, and heartbeat regularity must use other programs for measurement. To overcome this limitation, in this study, we successfully developed a one-stop ImageJ-based method using kymograph macros language that is able to obtain multiple cardiac performance endpoints simultaneously for the first time. To validate its utility, we incubated Daphnia magna at different ambient temperatures and exposed zebrafish with astemizole to detect the corresponding cardiac performance alterations. In summary, the kymograph method reported in this study provides a new, easy to use, and inexpensive one-stop method obtaining multiple cardiac performance endpoints with high accuracy and convenience.

Darwin's two competing phylogenetic trees: marsupials as ancestors or sister taxa?

2012 ◽  
Vol 39 (2) ◽  
pp. 217-233 ◽  
Author(s):  
J. David Archibald
Keyword(s):  
Fossil Record ◽  
Evolutionary Biology ◽  
Phylogenetic Trees ◽  
Charles Darwin ◽  
The Other ◽  
Charles Lyell ◽  
Single Origin ◽  
Molecular Studies ◽  
Richard Owen ◽  
First Time

Studies of the origin and diversification of major groups of plants and animals are contentious topics in current evolutionary biology. This includes the study of the timing and relationships of the two major clades of extant mammals – marsupials and placentals. Molecular studies concerned with marsupial and placental origin and diversification can be at odds with the fossil record. Such studies are, however, not a recent phenomenon. Over 150 years ago Charles Darwin weighed two alternative views on the origin of marsupials and placentals. Less than a year after the publication of On the origin of species, Darwin outlined these in a letter to Charles Lyell dated 23 September 1860. The letter concluded with two competing phylogenetic diagrams. One showed marsupials as ancestral to both living marsupials and placentals, whereas the other showed a non-marsupial, non-placental as being ancestral to both living marsupials and placentals. These two diagrams are published here for the first time. These are the only such competing phylogenetic diagrams that Darwin is known to have produced. In addition to examining the question of mammalian origins in this letter and in other manuscript notes discussed here, Darwin confronted the broader issue as to whether major groups of animals had a single origin (monophyly) or were the result of “continuous creation” as advocated for some groups by Richard Owen. Charles Lyell had held similar views to those of Owen, but it is clear from correspondence with Darwin that he was beginning to accept the idea of monophyly of major groups.

Disinfection of Fruits with Activated Water

2019 ◽  
Vol 10 ◽  
pp. 1864-1872
Author(s):  
Prof. Teodora P. Popova
Keyword(s):  
Antimicrobial Activity ◽  
Aqueous Solutions ◽  
Antimicrobial Properties ◽  
The Other ◽  
Gram Negative Bacteria ◽  
High Antimicrobial Activity ◽  
Gram Negative ◽  
E Coli ◽  
Number Of Microorganisms ◽  
Lower Effect

The effect of ionized aqueous solutions (anolytes and catholyte) in the processing of fruits (cherries, morellos, and strawberries) for decontamination has been tested. Freshly prepared analytes and catholyte without the addition of salts were used, as well as stored for 7 months anolytes, prepared with 0.5% NaCl and a combination of 0.5% NaCl and 0.5% Na2CO3. The anolyte prepared with a combination of 0.5% NaCl and 0.5% Na2CO3, as well as the anolyte obtained with 0.5% NaCl, exhibit high antimicrobial activity against the surface microflora of strawberries, cherries, and sour cherries. They inactivate E. coli for 15 minutes. The other species of the fam. Enterobacteriaceae were also affected to the maximum extent, as is the total number of microorganisms, especially in cherries and sour cherries. Even stored for 7 months, they largely retain their antimicrobial properties. Anolyte and catholyte, obtained without the addition of salts, showed a lower effect on the total number of microorganisms, but had a significant effect on Gram-negative bacteria, and especially with regard to the sanitary indicative E. coli.

Sphagnum mosses (Sphagnaceae, Bryophyta) of mires Chefandzar and Masota in North Ossetia (Caucasus)

2018 ◽  
Vol 52 (2) ◽  
pp. 455-462 ◽  
Author(s):  
G. Ya. Doroshina ◽  
I. A. Nikolajev
Keyword(s):  
Plant Communities ◽  
The Other ◽  
North Caucasus ◽  
Sphagnum Mosses ◽  
Greater Caucasus ◽  
The North ◽  
First Time ◽  
North Ossetia

Sphagnum mires on the Greater Caucasus are rare, characterized by the presence of relict plant communities of glacial age and are in a stage of degradation. The study of Sphagnum of Chefandzar and Masota mires is carried out for the first time. Seven species of Sphagnum are recorded. Their distribution and frequency within the North Caucasus are analyzed. Sphagnum contortum, S. platyphyllum, S. russowii, S. squarrosum are recorded for the first time for the study area and for the flora of North Ossetia. The other mosses found in the study area are listed.

An Epistemological Criticism of Social Entrepreneurship: Is Social Entrepreneurship a Sound Scientific Field of Research

2018 ◽  
Author(s):  
Amir Forouharfar
Keyword(s):  
Social Entrepreneurship ◽  
Social Constructivism ◽  
Social Epistemology ◽  
American English ◽  
Meta Analysis ◽  
Research Question ◽  
Knowledge Structure ◽  
Scientific Field ◽  
The Other ◽  
First Time

The paper was shaped around the pivotal question: Is SE a sound and scientific field of research? The question has given a critical tone to the paper and has also helped to bring out some of the controversial debates in the realm of SE. The paper was organized under five main discussions to be able to provide a scientific answer to the research question: (1)<b> </b>is “social entrepreneurship” an oxymoron?, (2) the characteristics of SE knowledge, (3) sources of social entrepreneurship knowledge, (4) SE knowledge: structure and limitations and (5) contributing epistemology-making concepts for SE.<b> </b>Based on the sections,<b> </b>the study relied on the relevant philosophical schools of thought in <i>Epistemology </i>(e.g. <i>Empiricism</i>, <i>Rationalism</i>, <i>Skepticism</i>, <i>Internalism</i> vs. <i>Externalism</i>,<i> Essentialism, Social Constructivism</i>, <i>Social Epistemology, etc.</i>) to discuss these controversies around SE and proposes some solutions by reviewing SE literature. Also, to determine the governing linguistic discourse in the realm of SE, which was necessary for our discussion,<i> Corpus of Contemporary American English (COCA)</i> for the first time in SE studies was used. Further, through the study, SE buzzwords which constitute SE terminology were derived and introduced to help us narrowing down and converging the thoughts in this field and demarking the epistemological boundaries of SE. The originality of the paper on one hand lies in its pioneering discussions on SE epistemology and on the other hand in paving the way for a construction of sound epistemology for SE; therefore in many cases after preparing the philosophical ground for the discussions, it went beyond the prevalent SE literature through meta-analysis to discuss the cases which were raised. The results of the study verified previously claimed embryonic pre-paradigmatic phase in SE which was far from a sound and scientific knowledge, although the scholarly endeavors are the harbingers of such a possibility in the future which calls for further mature academic discussion and development of SE knowledge by the SE academia.

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