Separation and Characterization of Standard Propoxyphene Diastereomers and Their Determination in Pharmaceutical and Illicit Preparations

1981 ◽  
Vol 64 (4) ◽  
pp. 875-883
Author(s):  
Shiv K Soni ◽  
Daniel Van Gelder
Keyword(s):  
High Pressure ◽  
Optical Isomers ◽  
Gold Chloride ◽  
Melting Points ◽  
Eutectic Melting ◽  
Racemic Mixtures ◽  
The Individual ◽  
Isomeric Mixtures ◽  
Asymmetric Carbon

Abstract Due to the existence of 2 asymmetric carbon atoms in: the propoxyphene molecule, there are 4 diastereomers: alpha dextro, alpha levo, beta dextro, and beta levo. Only α-d-propoxyphene is included under the federal Controlled Substances Act. Baseline separations of propoxyphene from various incipients (aspirin, caffeine, phenacetin, and acetaminophen) present in pharmaceutical and illicit preparations, and between the alpha and beta diastereomers, were achieved by high pressure liquid chromatography. The column eluant was collected and propoxyphene was extracted. The optical isomers were differentiated and characterized by melting points and by chemical microcrystalline tests. Using hot stage thermomicroscopy, the eutectic melting points of binary isomeric mixtures of propoxyphene bases and salts were found to be depressed about 10° and 15-30°C, respectively, below the individual isomer melting points. The characteristic microcrystals formed with the alpha racemic mixtures by using a glycerin-aqueous gold chloride reagent were not produced by the beta racemic mixtures.

scholarly journals Effect of Lateral Substitution on the Electronics and Phase Transitions of Stilbazoles, Benzoic Acids, Phenols, and Hydrogen Bonded Mixtures

2015 ◽  
Vol 2015 ◽  
pp. 1-14
Author(s):  
Jeremy R. Wolf
Keyword(s):  
Liquid Crystalline ◽  
Benzoic Acids ◽  
Minimal Effect ◽  
Melting Points ◽  
Effective Technique ◽  
Liquid Crystalline Phases ◽  
The Individual ◽  
Bonded Complexes ◽  
Hydrogen Bonded

The preparation and characterization of laterally substituted 4-alkoxy-stilbazoles, 4-alkoxy-benzoic acids, and 4-alkoxy phenols and hydrogen bonded heterodimeric mixtures of these compounds are reported. Lateral substitution has a minimal effect on the ring electronics of 4-alkoxy benzoic acids and 4-alkoxy phenols; however the ring electronics of stilbazole units is extremely sensitive to lateral substitution. While lateral substitution is an effective technique for lowering the melting points of both hydrogen bonded complexes and their individual components, its effect on the electronics of stilbazoles and steric disruption of both intermolecular hydrogen bonding and molecular packing in the solid state disrupts the formation of liquid crystalline phases in both the individual components and hydrogen bonded complexes.

scholarly journals Does higher education properly prepare graduates for the growing artificial intelligence market? Gaps identification using text mining

2021 ◽  
pp. 1-13
Author(s):  
Lamiae Benhayoun ◽  
Daniel Lang
Keyword(s):  
Artificial Intelligence ◽  
Natural Language Processing ◽  
Text Mining ◽  
Natural Language ◽  
Language Processing ◽  
Academic Training ◽  
Market Requirements ◽  
Job Advertisements ◽  
The Individual

BACKGROUND: The renewed advent of Artificial Intelligence (AI) is inducing profound changes in the classic categories of technology professions and is creating the need for new specific skills. OBJECTIVE: Identify the gaps in terms of skills between academic training on AI in French engineering and Business Schools, and the requirements of the labour market. METHOD: Extraction of AI training contents from the schools’ websites and scraping of a job advertisements’ website. Then, analysis based on a text mining approach with a Python code for Natural Language Processing. RESULTS: Categorization of occupations related to AI. Characterization of three classes of skills for the AI market: Technical, Soft and Interdisciplinary. Skills’ gaps concern some professional certifications and the mastery of specific tools, research abilities, and awareness of ethical and regulatory dimensions of AI. CONCLUSIONS: A deep analysis using algorithms for Natural Language Processing. Results that provide a better understanding of the AI capability components at the individual and the organizational levels. A study that can help shape educational programs to respond to the AI market requirements.

scholarly journals 3D characterization of individual grains of coexisting high-pressure H2O ice phases by time-domain Brillouin scattering

2021 ◽  
Vol 130 (5) ◽  
pp. 053104
Author(s):  
Sathyan Sandeep ◽  
Théo Thréard ◽  
Elton De Lima Savi ◽  
Nikolay Chigarev ◽  
Alain Bulou ◽  
...  
Keyword(s):  
High Pressure ◽  
Time Domain ◽  
Brillouin Scattering ◽  
Individual Grains

scholarly journals Multianvil High-Pressure/High-Temperature Synthesis and Characterization of multiferroic HP-Co3TeO6

2021 ◽  
Author(s):  
Gunter Heymann ◽  
Elisabeth Selb ◽  
Toni Buttlar ◽  
Oliver Janka ◽  
Martina Tribus ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Type Structure ◽  
Synthesis And Characterization ◽  
Temperature Synthesis ◽  
Space Group ◽  
Crystal System ◽  
High Temperature Synthesis ◽  
High Pressure High Temperature

By high-pressure/high-temperature multianvil synthesis a new high-pressure (HP) phase of Co3TeO6 was obtained. The compound crystallizes in the acentric trigonal crystal system of the Ni3TeO6-type structure with space group R3...

scholarly journals Material Geometry of Binary Composites

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 892
Author(s):  
Marcelo Epstein
Keyword(s):  
Continuum Mechanics ◽  
Mathematical Framework ◽  
Double Groupoid ◽  
The Individual ◽  
Elastic Composites

The constitutive characterization of the uniformity and homogeneity of binary elastic composites is presented in terms of a combination of the material groupoids of the individual constituents. The incorporation of these two groupoids within a single double groupoid is proposed as a viable mathematical framework for a unified formulation of this and similar kinds of problems in continuum mechanics.

scholarly journals Preclinical Testing of Radiopharmaceuticals for the Detection and Characterization of Osteomyelitis: Experiences from a Porcine Model

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4221
Author(s):  
Aage Kristian Olsen Alstrup ◽  
Svend Borup Jensen ◽  
Ole Lerberg Nielsen ◽  
Lars Jødal ◽  
Pia Afzelius
Keyword(s):  
Animal Model ◽  
Animal Models ◽  
Porcine Model ◽  
Animal Experiments ◽  
Radioactive Tracers ◽  
The Individual ◽  
Selection Of

The development of new and better radioactive tracers capable of detecting and characterizing osteomyelitis is an ongoing process, mainly because available tracers lack selectivity towards osteomyelitis. An integrated part of developing new tracers is the performance of in vivo tests using appropriate animal models. The available animal models for osteomyelitis are also far from ideal. Therefore, developing improved animal osteomyelitis models is as important as developing new radioactive tracers. We recently published a review on radioactive tracers. In this review, we only present and discuss osteomyelitis models. Three ethical aspects (3R) are essential when exposing experimental animals to infections. Thus, we should perform experiments in vitro rather than in vivo (Replacement), use as few animals as possible (Reduction), and impose as little pain on the animal as possible (Refinement). The gain for humans should by far exceed the disadvantages for the individual experimental animal. To this end, the translational value of animal experiments is crucial. We therefore need a robust and well-characterized animal model to evaluate new osteomyelitis tracers to be sure that unpredicted variation in the animal model does not lead to a misinterpretation of the tracer behavior. In this review, we focus on how the development of radioactive tracers relies heavily on the selection of a reliable animal model, and we base the discussions on our own experience with a porcine model.

scholarly journals High-pressure synthesis and characterization of the non-centrosymmetric scandium borate ScB6O9(OH)3

2020 ◽  
Vol 75 (6-7) ◽  
pp. 597-603
Author(s):  
Birgit Fuchs ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Structure Solution ◽  
Temperature Experiment ◽  
Pressure Synthesis

AbstractThe non-centrosymmetric scandium borate ScB6O9(OH)3 was obtained through a high-pressure/high-temperature experiment at 6 GPa and 1473 K. Single-crystal X-ray diffraction revealed that the structure is isotypic to InB6O9(OH)3 containing borate triple layers separated by scandium layers. The compound crystallizes in the space group Fdd2 with the lattice parameters a = 38.935(4), b = 4.4136(4), and c = 7.6342(6) Å. Powder X-ray diffraction and vibrational spectroscopy were used to further characterize the compound and verify the proposed structure solution.

scholarly journals Molecular characterization of a beta zero-thalassemia resulting from a 1.4 kilobase deletion

Blood ◽  
1988 ◽  
Vol 72 (2) ◽  
pp. 636-641 ◽  
Author(s):  
R Anand ◽  
CD Boehm ◽  
HH Jr Kazazian ◽  
EF Vanin
Keyword(s):  
Transcriptional Start Site ◽  
Globin Gene ◽  
Event Analysis ◽  
Beta Globin ◽  
Base Pairs ◽  
Dna Polymerase Alpha ◽  
Beta Globin Gene ◽  
American Black ◽  
The Individual

Abstract We report the characterization of a beta zero-thalassemia in an American Black with unusually high HbA2 and HbF levels. Genomic southern analysis indicated that the individual was heterozygous for a deletion that began within the second intervening sequence of the beta- globin gene and extended approximately 1.4 kb in the 5′ direction. A clone spanning the breakpoint on the abnormal chromosome was isolated and further mapped, and the deletion joint was sequenced. Comparison of the normal beta-globin gene and its 5′ flanking region with the deletion joint sequence indicated that the 5′ breakpoint for this deletion was 484 base pairs (bp) 5′ to the transcriptional start site for the beta-globin gene and the 3′ breakpoint was 908 bp into the beta- globin gene; the deletion removed a total of 1,393 bp. Comparison of the normal 5′ and 3′ breakpoint sequences indicated that this deletion was the result of a “clean” nonhomologous breakage and reunion event; ie, no spurious bases were added during the recombinational event. Analysis of the breakpoints of this deletion together with the breakpoints of two other small deletions involving the beta-globin gene suggests that the breakpoints may occur at DNA polymerase alpha pause sites.

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