Über die Kristallisation von Jod und Jodiden in Gelen

Zusammenfassung Aus einer Reihe von Untersuchungen über Bildung, Niederschlagung, scheinbaren Bewegung und Austausch von kristallinem Jod und unl?slichen kristallinen Jodiden in verschiedenen Gelen und anderen Mitteln wurde gefolgert, da? die Prozesse der Niederschlagung des Reaktionsproduktes und der Diffusion dieses Produktes nicht voneinander getrennt werden k?nnen. Es wurde darauf hingewiesen, da? die offensichtliche Wanderung von kristallinem Jod und unl?slichen kristallinen Jodiden in Gelstrukturen sich als eine Folge der Wiederaufl?sung in einem Teil der Kristallmasse und der Wiederablagerung an einem andern Teile zu ergeben scheint. Untersuchungen über den Austausch von kristallinem Jod durch unl?sliche Jodide und umgekehrt haben gezeigt, da? unter gewissen passenden Diffusionsbedingungen, wie z. B. im Kiesels?uregel, sich pseudomorphe Kristalle bilden k?nnen. Pseudomorphe Kristalle wurden in kapillaren R?umen zwischen Glasplatten nicht erhalten, obzwar sich eine ausgesprochene Neigung hierzu zeigte. Material wurde dargelegt, um zu zeigen, da? sich verschiedene Arten von Jodablagerungen als eine Folge der Wirkung des Mittels ergeben k?nnen. Diese Ablagerungen k?nnen sich von kolloiden bis zu makroskopischen Dimensionen und von sehr verzerrten bis zu fast vollkommenen kristallinen Formen erstrecken. Unter gewissen Bedingungen scheinen sich Somatoide zu bilden. Umgebungen, in denen diese Reaktionen ausgeführt wurden, waren a) verschiedene Gele, b) Schichten zwischen Glasplatten, c) Poren absorbierenden Papiers und d) Membranoberfl?chen.     

Lettera del prof. G. A. Miller al prof. Luigi Bianchi

P. S. — In view of the delay in writing I would say that you have my permission to publish the above letter in order to avoid the spreading of these errors.G. A. Miller     

Zur Untersuchung von Zuckersirup

Ohne Zusammenfassung     

Two-dimensional solidification of viscous flow over a semi infinite plate with constant heat removal

Two-dimensional solidification of forced viscous flow over a semi infinite flat plate is considered. The plate is initially maintained at a constant temperature above the freezing point of the liquid. At time t>0, heat is removed from the plate so that the liquid freezes. The continuity equation and the two-dimensional, nonsteady, momentum and energy equations in the liquid and solid phases are solved numerically. The growth of the solid layer as a function of time and position along the plate is determined.     

The Extracts of Polygonum cuspidatum Root and Rhizome Block the Entry of SARS-CoV-2 Wild-Type and Omicron Pseudotyped Viruses via Inhibition of the S-Protein and 3CL Protease

COVID-19, resulting from infection by the SARS-CoV-2 virus, caused a contagious pandemic. Even with the current vaccines, there is still an urgent need to develop effective pharmacological treatments against this deadly disease. Here, we show that the water and ethanol extracts of the root and rhizome of Polygonum cuspidatum (Polygoni Cuspidati Rhizoma et Radix), a common Chinese herbal medicine, blocked the entry of wild-type and the omicron variant of the SARS-CoV-2 pseudotyped virus into fibroblasts or zebrafish larvae, with IC₅₀ values ranging from 0.015 to 0.04 mg/mL. The extracts were shown to inhibit various aspects of the pseudovirus entry, including the interaction between the spike protein (S-protein) and the angiotensin-converting enzyme II (ACE2) receptor, and the 3CL protease activity. Out of the chemical compounds tested in this report, gallic acid, a phytochemical in P. cuspidatum, was shown to have a significant anti-viral effect. Therefore, this might be responsible, at least in part, for the anti-viral efficacy of the herbal extract. Together, our data suggest that the extracts of P. cuspidatum inhibit the entry of wild-type and the omicron variant of SARS-CoV-2, and so they could be considered as potent treatments against COVID-19.     

Torsionally broken symmetry assists infrared excitation of biomimetic charge-coupled nuclear motions in the electronic ground state

The concerted interplay between reactive nuclear and electronic motions in molecules actuates chemistry. Here, we demonstrate that out-of-plane torsional deformation and vibrational excitation of stretching motions in the electronic ground state modulate the charge-density distribution in a donor-bridge-acceptor molecule in solution. The vibrationally-induced change, visualised by transient absorption spectroscopy with a mid-infrared pump and a visible probe, is mechanistically resolved by ab initio molecular dynamics simulations. Mapping the potential energy landscape attributes the observed charge-coupled coherent nuclear motions to the population of the initial segment of a double-bond isomerization channel, also seen in biological molecules. Our results illustrate the pivotal role of pre-twisted molecular geometries in enhancing the transfer of vibrational energy to specific molecular modes, prior to thermal redistribution. This motivates the search for synthetic strategies towards achieving potentially new infrared-mediated chemistry.

Channelling vibrational excitation energy to achieve ground-state charge-transfer (CT)-assisted isomerization in a donor-bridge-acceptor molecule in solution.