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On the basis of a novel ynol‐diene cyclization developed as a rapid access to tropone unit, the first divergent strategy to 17‐nor‐cephalotane diterpenoids has been successfully established. Combining with a bioinspired stereoselective dual hydrogenation, the divergent total synthesis of (+)‐3‐deoxyfortalpinoid F, (+)‐harringtonolide, (−)‐fortalpinoids M/N/P, and analog (−)‐20‐deoxocephinoid P have been achieved in 14–17 linear longest steps starting from commercially available materials. [ABSTRACT FROM AUTHOR]

The mechanism of action of aloe-emodin for improving type II diabetes was investigated by network pharmacology combined with molecular docking technique. The potential targets of aloe-emodin and the related targets for improving the treatment of type II diabetes were screened by using the database platform, and the potential targets of aloe-emodin for improving type II diabetes were obtained by intersecting the two. The protein interaction network between the common targets was constructed, and the GO function annotation and KEGG pathway enrichment analysis were performed for the common targets.By screening the main pathways and constructing a network diagram of "aloe-emodin-type II diabetes-pathway", this study visualized the linkage between aloe emodin and the pathways and the targets enriched by each pathway and studied the binding mechanism between aloe-emodin and the key targets through molecular docking. Results showed that aloe-emodin had 63 targets for improving the treatment of type II diabetes, and 22 core targets, including AKT1, PIK3CA, HRAS, and MAPK8, were identified based on the protein interaction network, which was mainly enriched in PI3K/AKT and insulin resistance signaling pathways. Aloe-emodin bound to the targets mainly through intermolecular forces such as hydrogen bonding, van der Waals forces, and π-π interactions, thus regulating the expression of the targets and improving type II diabetes. [ABSTRACT FROM AUTHOR]

Compared with the movement of corn seeds in the sowing machine, the movement in the threshing machine is more intense. The collision between corn seeds and threshing parts and other corn seeds will not only change the movement path of corn seeds in the threshing clearance but also cause damage to corn seeds. Therefore, when using discrete element simulation technology to optimize the critical components of corn threshing machinery, it is necessary to measure corn seeds' accurate collision recovery coefficient. However, when measuring the collision recovery coefficient between corn seeds, there will be multi-point collisions between corn seeds, affecting the measurement results' accuracy. In order to solve this problem, this study combined high-speed photography and the sound waveform of corn seed collision to eliminate the interference of the multi-point collision phenomenon and improve the accuracy of measurement results. According to the above test method, the contact parameters of corn seeds were measured. Finally, the corn–corn rolling friction coefficient and corn–PMMA rolling friction coefficient were 0.0784 and 0.0934, respectively. The corn–corn static friction coefficient was 0.32, and the corn–PMMA static friction coefficient was 0.445. The corn–corn collision recovery and corn–PMMA collision recovery coefficients were 0.28 and 0.62, respectively. After that, the method's reliability and the measurement results' accuracy were verified by the plane collision test and repose angle test. [ABSTRACT FROM AUTHOR]

The collapse potential, mineralogy, microstructure, and particle morphology of a loess from the Loess Plateau, China, were characterized by double oedometer testing, X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, and image analysis to elucidate the origin of its collapse behavior. Results show that the loess is highly collapsible with a maximum collapse index of 6.7% at a vertical stress of ~200 kPa. The deposit contains both nonclay (i.e., quartz, albite, muscovite, and calcite) and clay (i.e., two chlorites) minerals. Microstructural, chemical, and image analyses indicate that interparticle calcite and clay cementation and silt particle morphology render the intact soil a metastable structure. Wetting-induced collapse is attributed to both primary and secondary microstructure features. The former is the abundance of weakly cemented, unsaturated, porous pure clay and clay-silt mixture aggregates whose slaking upon wetting initiates the overall structural collapse, while the latter consists of high porosity, unstable particle contacts, and clay coating on silt particles that act synergistically to augment the collapse. A conceptual microstructural model of a four-tiered hierarchy (i.e., primary clay and silt particles, clay aggregates and clay-coated silt particles, clay-silt mixture aggregates, and cemented aggregate matrix) is proposed to represent its structural characteristics and to account for its high collapsibility. Key words: collapsibility, loess, microstructure, mineralogy, particle morphology, silt. Le potentiel d'affaissement, la structure mineralogique, la microstructure et la morphologie particulaire d'un loess provenant du Plateau de Loess, en Chine, ont ete caracterises a l'aide d'essais a l'oedometre double, par diffraction des rayons X, au moyen de la microscopie electronique a balayage associee a la spectroscopie a rayons X a dispersion d'energie et par analyse d'images, afin de connaitre l'origine de l'affaissement du loess etudie. Les resultats obtenus montrent que ce dernier est fortement susceptible de s'affaisser, son indice maximal d'affaissement etant egal a 6,7 % pour une contrainte verticale d'environ 200 kPa. Le depot de loess contient a la fois des mineraux non argileux (c.-a-d. du quartz, de l'albite, de la muscovite et de la calcite) et argileux (c.-a-d. deux chlorites). Des analyses microstructurales, chimiques et d'images montrent que la cimentation interparticulaire de la calcite et de l'argile et la morphologie des particules de limon transforment le sol intact en structure metastable. L'affaissement du a l'humification s'explique par les caracteristiques des microstructures primaires et secondaires. La microstructure primaire est caracterisee par l'abondance d'agregats faiblement cimentes, non satures et poreux d'argile pure et de limon argileux dont le ramollissement du a l'humidification amorce l'affaissement structural, alors que la microstructure secondaire consiste en des particules de limon instable et fortement poreux en contact les unes avec les autres et en une couche d'argile recouvrant ces dernieres, l'ensemble contribuant a accentuer le phenomene d'affaissement. Un modele microstructural conceptuel a quatre niveaux (soit les particules primaires d'argile et de limon, les agregats d'argile et les particules de limon recouvertes d'argile, les agregats de limon argileux et la matrice formee par les agregats cimentes) est propose pour illustrer les caracteristiques structurales du loess etudie et pour expliquer sa forte tendance a s'affaisser. [Traduit par la Redaction] Mots-cles: tendance a l'affaissement, loess, microstructure, mineralogie, morphologie particulaire, limon., Introduction Loess, an aeolian, nonstratified deposit, is composed of primarily silt-sized particles with small fractions of clay and sand particles. It occurs widely around the world, including Asia, Africa, central [...]