Synthetic Steroidal Sapogenins. Part III1 23-Ketohecogenin and 23-Ketoisochiapagenin

The synthesis of the 23-keto analogues of the steroidal sapogenins hecogenin and isochiapagenin is described.     

23S state of helium

A rapidly convergent method, which has previously been applied to the ground state of the helium atom, has been extended to excited S states. This method is based on an expansion of the wave function in powers of \documentclass{article}\pagestyle{empty}\begin{document}$ \sqrt {r_1^2 + r_2^2} $\end{document}, ln (r + r), \documentclass{article}\pagestyle{empty}\begin{document}$ w = r_{12} /\sqrt {r_1^2 + r_2^2} $\end{document}. Different effective nuclear charges are used for the inner and the outer electrons. Very satisfactory results are obtained for expectation values of various operators.     

Structure of Nanobody Nb23

Background: Nanobodies, or VHHs, are derived from heavy chain-only antibodies (hcAbs) found in camelids. They overcome some of the inherent limitations of monoclonal antibodies (mAbs) and derivatives thereof, due to their smaller molecular size and higher stability, and thus present an alternative to mAbs for therapeutic use. Two nanobodies, Nb23 and Nb24, have been shown to similarly inhibit the self-aggregation of very amyloidogenic variants of β2-microglobulin. Here, the structure of Nb23 was modeled with the Chemical-Shift (CS)-Rosetta server using chemical shift assignments from nuclear magnetic resonance (NMR) spectroscopy experiments, and used as prior knowledge in PONDEROSA restrained modeling based on experimentally assessed internuclear distances. Further validation was comparatively obtained with the results of molecular dynamics trajectories calculated from the resulting best energy-minimized Nb23 conformers. Methods: 2D and 3D NMR spectroscopy experiments were carried out to determine the assignment of the backbone and side chain hydrogen, nitrogen and carbon resonances to extract chemical shifts and interproton separations for restrained modeling. Results: The solution structure of isolated Nb23 nanobody was determined. Conclusions: The structural analysis indicated that isolated Nb23 has a dynamic CDR3 loop distributed over different orientations with respect to Nb24, which could determine differences in target antigen affinity or complex lability.     

第23届国际凝聚态核科学会议（ICCF-23）介绍

ICCF是凝聚态核科学研究领域最重要的系列性国际会议, ICCF-23于2021年6月9～11日在厦门大学召开,会议主席是田中群院士.共有33个国家和地区的433名代表参会,收录摘要86篇.本次会议的主要进展是多个小组在Pd(Ni)-D_2O(H_2O)电解体系和Pd(Ni)-D_2(H_2)体系中观测到超热,突破了传统上只有Pd-D和Ni-H体系才能产生超热的成见;多个小组在合金-D_2(H_2)体系中观测到稳定的十瓦级超热;两个小组证实氧化层在超热产生中起重要作用,纳米或介观尺寸样品明显好于体样品.多个小组观测到含氢体系在电解、气相和放电条件下的核嬗变并呈现出某种规律性.     

Solanum-alkaloide—Cl : Absolute konfiguration 23-hydroxylierter 22,26-epimino-cholestane an C-22 und C-23

According to X-ray analysis of(22S:23R:25S)-22,26-epimino-5α-cholestane-3β,16β,23-triolhydrobromide (4-HBr) the assignment of the absolute configuration of the 23-hydroxylated 22,26-epimino-cholestanes 4 and 5 has been corrected.     

Distinction of absolute configuration at C-22 of C-23-hydroxyspirostane and C-23-hydroxyspirosolane glycosides

It has been revealed that the absolute configurations at C-22 of 23-hydroxyspirostane and 23-hydroxyspirosolane could be unambiguouly judged by the (1)H- and (13)C-NMR spectroscopies.