Two Anhydrous and a Trihydrate Form of Tilorone Dihydrochloride: Hydrogen-Bonding Patterns and Reversible Hydration/Dehydration Solid-State Transformation

During the polymorph screening of an active pharmaceutical ingredient tilorone dihydrochloride (chemical name 2,7-bis­[2-(diethylamino)­ethoxy]-9-fluorenone dihydrochloride) two new polymorphic modifications  <b>III</b> and <b>IV</b>  were obtained. The crystal structures of both polymorphs were established from X-ray powder diffraction. An interesting phenomenon has been observed at ambient conditions for <b>III</b>, which transforms into a novel hydrated form <b>IIIh</b> during 2–3 h when the humidity in the storage room increases to 70% or more. As soon as the relative humidity falls to 30% or less, <b>IIIh</b> transforms into the parent anhydrous form <b>III</b> within an hour. Form <b>IIIh</b> has been identified as a trihydrate of tilorone dihydrochloride, and its crystal structure has been established from X-ray powder diffraction. On the basis of the crystal structures and hydrogen-bonding patterns, a mechanistic model of reversible hydration/dehydration solid-state transformation <b>III</b> ↔ <b>IIIh</b> depending on the relative humidity is proposed

Two Anhydrous and a Trihydrate Form of Tilorone Dihydrochloride: Hydrogen-Bonding Patterns and Reversible Hydration/Dehydration Solid-State Transformation

During the polymorph screening of an active pharmaceutical ingredient tilorone dihydrochloride (chemical name 2,7-bis­[2-(diethylamino)­ethoxy]-9-fluorenone dihydrochloride) two new polymorphic modifications  <b>III</b> and <b>IV</b>  were obtained. The crystal structures of both polymorphs were established from X-ray powder diffraction. An interesting phenomenon has been observed at ambient conditions for <b>III</b>, which transforms into a novel hydrated form <b>IIIh</b> during 2–3 h when the humidity in the storage room increases to 70% or more. As soon as the relative humidity falls to 30% or less, <b>IIIh</b> transforms into the parent anhydrous form <b>III</b> within an hour. Form <b>IIIh</b> has been identified as a trihydrate of tilorone dihydrochloride, and its crystal structure has been established from X-ray powder diffraction. On the basis of the crystal structures and hydrogen-bonding patterns, a mechanistic model of reversible hydration/dehydration solid-state transformation <b>III</b> ↔ <b>IIIh</b> depending on the relative humidity is proposed

Two Anhydrous and a Trihydrate Form of Tilorone Dihydrochloride: Hydrogen-Bonding Patterns and Reversible Hydration/Dehydration Solid-State Transformation

During the polymorph screening of an active pharmaceutical ingredient tilorone dihydrochloride (chemical name 2,7-bis­[2-(diethylamino)­ethoxy]-9-fluorenone dihydrochloride) two new polymorphic modifications  <b>III</b> and <b>IV</b>  were obtained. The crystal structures of both polymorphs were established from X-ray powder diffraction. An interesting phenomenon has been observed at ambient conditions for <b>III</b>, which transforms into a novel hydrated form <b>IIIh</b> during 2–3 h when the humidity in the storage room increases to 70% or more. As soon as the relative humidity falls to 30% or less, <b>IIIh</b> transforms into the parent anhydrous form <b>III</b> within an hour. Form <b>IIIh</b> has been identified as a trihydrate of tilorone dihydrochloride, and its crystal structure has been established from X-ray powder diffraction. On the basis of the crystal structures and hydrogen-bonding patterns, a mechanistic model of reversible hydration/dehydration solid-state transformation <b>III</b> ↔ <b>IIIh</b> depending on the relative humidity is proposed

Two Anhydrous and a Trihydrate Form of Tilorone Dihydrochloride: Hydrogen-Bonding Patterns and Reversible Hydration/Dehydration Solid-State Transformation

During the polymorph screening of an active pharmaceutical ingredient tilorone dihydrochloride (chemical name 2,7-bis­[2-(diethylamino)­ethoxy]-9-fluorenone dihydrochloride) two new polymorphic modifications  <b>III</b> and <b>IV</b>  were obtained. The crystal structures of both polymorphs were established from X-ray powder diffraction. An interesting phenomenon has been observed at ambient conditions for <b>III</b>, which transforms into a novel hydrated form <b>IIIh</b> during 2–3 h when the humidity in the storage room increases to 70% or more. As soon as the relative humidity falls to 30% or less, <b>IIIh</b> transforms into the parent anhydrous form <b>III</b> within an hour. Form <b>IIIh</b> has been identified as a trihydrate of tilorone dihydrochloride, and its crystal structure has been established from X-ray powder diffraction. On the basis of the crystal structures and hydrogen-bonding patterns, a mechanistic model of reversible hydration/dehydration solid-state transformation <b>III</b> ↔ <b>IIIh</b> depending on the relative humidity is proposed

From Humorous Post to Detailed Quantum-Chemical Study: Isocyanate Synthesis Revisited

Isocyanates play an essential role in modern manufacturing processes, especially in polyurethane production. There are numerous synthesis strategies for isocyanates both in industrial and laboratory conditions, which do not prevent searching for alternative highly efficient synthetic protocols. Here, we report a detailed theoretical investigation of the mechanism of sulfur dioxide-catalyzed rearrangement of the phenylnitrile oxide into phenyl isocyanate, which was first reported in 1977. The DLPNO-CCSD(T) method and up-to-date DFT protocols were used to perform a highly accurate quantum-chemical study of the rearrangement mechanism. An overview of various organic and inorganic catalysts has revealed other potential catalysts, such as sulfur trioxide and selenium dioxide. Furthermore, the present study elucidated how substituents in phenylnitrile oxide influence reaction kinetics. This study was performed by a self-organized collaboration of scientists initiated by a humorous post on the VK social network

Combined Impact of Magnetic Force and Spaceflight Conditions on Escherichia coli Physiology

Changes in bacterial physiology caused by the combined action of the magnetic force and microgravity were studied in Escherichia coli grown using a specially developed device aboard the International Space Station. The morphology and metabolism of E. coli grown under spaceflight (SF) or combined spaceflight and magnetic force (SF + MF) conditions were compared with ground cultivated bacteria grown under standard (control) or magnetic force (MF) conditions. SF, SF + MF, and MF conditions provided the up-regulation of Ag43 auto-transporter and cell auto-aggregation. The magnetic force caused visible clustering of non-sedimenting bacteria that formed matrix-containing aggregates under SF + MF and MF conditions. Cell auto-aggregation was accompanied by up-regulation of glyoxylate shunt enzymes and Vitamin B12 transporter BtuB. Under SF and SF + MF but not MF conditions nutrition and oxygen limitations were manifested by the down-regulation of glycolysis and TCA enzymes and the up-regulation of methylglyoxal bypass. Bacteria grown under combined SF + MF conditions demonstrated superior up-regulation of enzymes of the methylglyoxal bypass and down-regulation of glycolysis and TCA enzymes compared to SF conditions, suggesting that the magnetic force strengthened the effects of microgravity on the bacterial metabolism. This strengthening appeared to be due to magnetic force-dependent bacterial clustering within a small volume that reinforced the effects of the microgravity-driven absence of convectional flows

The hypothetical track-length fitting algorithm for energy measurement in liquid argon TPCs

International audienceThis paper introduces the hypothetical track-length fitting algorithm, a novel method for measuring the kinetic energies of ionizing particles in liquid argon time projection chambers (LArTPCs). The algorithm finds the most probable offset in track length for a track-like object by comparing the measured ionization density as a function of position with a theoretical prediction of the energy loss as a function of the energy, including models of electron recombination and detector response. The algorithm can be used to measure the energies of particles that interact before they stop, such as charged pions that are absorbed by argon nuclei. The algorithm's energy measurement resolutions and fractional biases are presented as functions of particle kinetic energy and number of track hits using samples of stopping secondary charged pions in data collected by the ProtoDUNE-SP detector, and also in a detailed simulation. Additional studies describe impact of the dE/dx model on energy measurement performance. The method described in this paper to characterize the energy measurement performance can be repeated in any LArTPC experiment using stopping secondary charged pions

The hypothetical track-length fitting algorithm for energy measurement in liquid argon TPCs

International audienceThis paper introduces the hypothetical track-length fitting algorithm, a novel method for measuring the kinetic energies of ionizing particles in liquid argon time projection chambers (LArTPCs). The algorithm finds the most probable offset in track length for a track-like object by comparing the measured ionization density as a function of position with a theoretical prediction of the energy loss as a function of the energy, including models of electron recombination and detector response. The algorithm can be used to measure the energies of particles that interact before they stop, such as charged pions that are absorbed by argon nuclei. The algorithm's energy measurement resolutions and fractional biases are presented as functions of particle kinetic energy and number of track hits using samples of stopping secondary charged pions in data collected by the ProtoDUNE-SP detector, and also in a detailed simulation. Additional studies describe impact of the dE/dx model on energy measurement performance. The method described in this paper to characterize the energy measurement performance can be repeated in any LArTPC experiment using stopping secondary charged pions