The chemical structures and biological activities of indole diterpenoids

Indole diterpenoids(IDTs)are an essential class of structurally diverse fungal secondary metabolites,that generally appear to be restricted to a limited number of fungi,such as Penicillium,Aspergillus,Claviceps,and Epichloe species,etc.These compounds share a typical core structure consisting of a cyclic diterpene skeleton of geranylgeranyl diphos-phate(GGPP)and an indole ring moiety derived from indole-3-glycerol phosphate(IGP).3-geranylgeranylindole(3-GGI)is the common precursor of all IDTs.On this basis,it is modified by cyclization,oxidation,and prenylation to generate a large class of compounds with complex structures.These compounds exhibit antibacterial,anti-insect,and ion channel inhibitory activities.We summarized 204 compounds of IDTs discovered from various fungi over the past 50 years,these compounds were reclassified,and their biological activities were summarized.This review will help to understand the structural diversity of IDTs and provide help for their physiological activities.

A classification method of building structures based on multi-feature fusion of UAV remote sensing images

In order to improve the accuracy of building structure identification using remote sensing images,a building structure classification method based on multi-feature fusion of UAV remote sensing image is proposed in this paper.Three identification approaches of remote sensing images are integrated in this method:object-oriented,texture feature,and digital elevation based on DSM and DEM.So RGB threshold classification method is used to classify the identification results.The accuracy of building structure classification based on each feature and the multi-feature fusion are compared and analyzed.The results show that the building structure classification method is feasible and can accurately identify the structures in large-area remote sensing images.

The nature of near-wall convection velocity in turbulent channel flow

A novel notion of turbulent structure the local cascade structure-is introduced to study the convection phenomenon in a turbulent channel flow. A space-time cross-correlation method is used to calculate the convection velocity. It is found that there are two characteristic convection speeds near the wall, one associated with small-scale streaks of a lower speed and another with streamwise vortices and hairpin vortices of a higher speed. The new concept of turbulent structure is powerful to illustrate the dominant role of coherent structures in the near-wall convection, and to reveal also the nature of the convection-the propagation of patterns of velocity fluctuations-which is scale-dependent.

A new method to test rock abrasiveness based on physico-mechanical and structural properties of rocks

A new method to test rock abrasiveness is proposed based upon the dependence of rock abrasiveness on their structural and physico-mechanical properties. The article describes the procedure of presentation of properties that govern rock abrasiveness on a canonical scale by dimensionless components, and the integrated estimation of the properties by a generalized index. The obtained results are compared with the known classifications of rock abrasiveness.

Morpho-structural Features and Structural Classification of Chromite Pods in the Tropoje-Has Ophiolite Massif, Albania

Tropoje-Has ophiolitic massif of eastern Mirdita(Albania)ophiolitic belt,is a major source for metallurgical chromite ore in Albania.Massif consists of a thick mantle section of SSZ type,8-10 km thick and

Review on evolution and evaluation of asphalt pavement structures and materials

The purpose of this study was to summarize the wide-range literatures on asphalt pavements, explore the evolution of road pavements, analyze typical asphalt pavement structures, highlight current trends in research and industry, and to recommend future areas of research and development. In this research, road pavement evolution was explored from the earliest roads to the modern pavements. A new method was recommended to categorize asphalt pavement materials into the three large families which may be further sub-divided according to their mechanical parameters. A unified asphalt pavement classification(UAPC) method was proposed and the worldwide asphalt pavements could be divided into six types through the new method. Based o n the UAPC method, 1087 asphalt pavement structures were classified and analyzed to explore the asphalt thickness variation. In order to evaluate asphalt pavement performance, the Chinese design specification was employed for analyzing lives of 29 high-volume pavements and 28 low-volume pavements. Through this research, it was found that:(1) in the past 100 years, asphalt pavement materials and structures had been becoming more and more strong;(2) asphalt layer thicknesses were various from 5 to 60 cm and the overall pavement thicknesses were various from 28 to 160 cm;(3) the long-life pavements in the other countries may become"shorter-life" pavements according to the prediction based on the Chinese specification.

A review of lignans from genus Kadsura and their spectrum characteristics

Kadsura belongs to the Schisandroideae subfamily of Magnoliaceae.Plants from genus Kadsura are widely distributed in the South and Southwest of China.The plants of the genus are widely used as folk medicine for a long time in history,with the functions of relieving pain,promoting 'qi' circulation,activating blood resolve stasis,and applications in the treatment of rheumatoid arthritis and gastroenteric disorders.Lignans are the primary characteristic constituents with various biological activities of plants from genus Kadsura.This paper summarized 81 lignans isolated from the plants of genus Kadsura over the past eight years(from 2014 to 2021),which belong to five types:dibenzocyclooctadienes,spirobenzofuranoid dibenzocyclooctadienes,aryltetralins,diarylbutanes and tetrahydrofurans.Each type of these lignans possess typical characteristics in proton magnetic resonance(^(1)H NMR) and carbon-13 nuclear magnetic resonance(^(13)C NMR) spectra,the NMR regularities of these types of lingans were summarized,which provided a useful reference for the structural analysis of lignans.The relationships between lignans and pharmacodynamics were also systematically analyzed,lignans were predicted to be the quality markers(Q-marker) of Kadsura genus.

Factors as predictors for thoracic and thoracolumbar/lumbar structural curves in adolescent idiopathic scoliosis

Background Recent studies have demonstrated that the Lenke system is relatively efficient and consistent in classifying scoliosis curves. Basically, fusion should include the main curve and the structural minor curve. The criteria for defining the structural minor curve were established to help guide these decision-making process. The present study was designed to investigate predictors of the structural curve, and see whether it was possible to prevent the formation of the structural curve by interfering with influencing factors to decrease the fusion level. Methods Age, gender, Cobb angle, Perdriolle rotation, Risser sign and the number of vertebrae included in the curve, brace treatment, and curve location were recorded in 145 idiopathic scoliosis patients from July 2001 to January 2007. The patients were divided into two groups： structural and non-structural groups. Demographics and baseline characteristics were compared between the two groups as an initial screen. Logistic regression was used to analyze factors affecting the minor curve to become the structural curve. Results Compared with the non-structural group, the structural group had a higher Cobb angle （（51.34±13.61）° vs. （34.20±7.21）°, P 〈0.001 ）, bending angle （（33.94±9.92）° vs. （8.46±5.56）°, P 〈0.001） and curve rotation （（23.25±12.86）° vs （14.21±8.55）°, p 〈0.001）, and lower flexibility （（33.48±12.53）% vs. （75.50±15.52）%, P 〈0.001 ）. There was no significant difference in other parameters between the two groups. The results of the Logistic regression analysis showed that the Cobb angle （OR： 9.921, P 〈0.001） and curve location （OR： 4.119, P=0.016） were significant predictors of structural curve in adolescent idiopathic scoliosis. Every 10~ change of Cobb angle increased the possibility of turning the minor curve into the structural curve by 10-fold. And thoracic curve showed, on the average, the possibility of becoming the structural curve about 4-fold more often than did the thoracolumbar/lumbar curve. Conclusions Curve severity and curve location affect the minor curve＇s structural features in adolescent idiopathic scoliosis.