The sweet rhizomes of Polygonatum cyrtonema are widely used as a tonic and functional food. A sensitive and rapid analytical method was developed for simultaneous identification and dynamic analysis of saccharides during steam processing in P. cyrtonema using HPLC–QTOF–MS/MS. Fructose, sorbitol, glucose, galactose, sucrose, and 1-kestose were identified, as well as a large number of oligosaccharides constituted of fructose units through β-(2→1) or β-(2→6). Polysaccharides and oligosaccharides were decomposed to monosaccharides during a steaming process, since the contents of glucose, galactose, and fructose were increased, while those of sucrose, 1-kestose, and polysaccharides were decreased. The high content of fructose was revealed to be the main determinant for increasing the level of sweetness after steaming. The samples of different repeated steaming times were shown to be well grouped and gradually shift along the PC1 (72.4%) axis by principal component analysis. The small-molecule saccharides, especially fructose, could be considered as markers for the steaming process of rhizomes of P. cyrtonema.

Polygonatum cyrtonema Hua is a traditional Chinese herb medicine, and it is widely distributed in China. The intrageneric taxonomy and phylogenetic relationships within Polygonatum have long been controversial due to their morphological similarity and lacking special DNA barcodes. In this paper, the complete chloroplast genome is a relatively conserved quadripartite structure including a large single copy region of 84 711 bp, a small single copy region of 18 210 bp, and a pair of inverted repeats region of 26 142 bp. A total of 342 simple sequence repeats were identified, and most of them were found to be composed of A/T, including 126 mono-nucleotides and 179 di-nucleotides. Nucleotide diversity was analyzed and eight highly variable regions (psbl∼trnT-CGU, atpF∼atpH, trnT-GGU∼psbD, psaJ∼rps20, trnL-UAG∼ndhD, ndhG∼ndhl, ndhA, and rpl32∼ccsA) were identified as potential molecular markers. Phylogenetic analysis based on the whole chloroplast genome showed that P. cyrtonema, within the family Asparagaceae, is closely related to Polygonatum sibiricum and Polygonatum kingianum. The sequence matK, trnT-GGU & ccsA, and ndhG∼ndhA were identified as three DNA barcodes. The assembly and comparative analysis of P. cyrtonema complete chloroplast genome will provide essential molecular information about the evolution and molecular biology for further study.

As an edible sclerotia-forming fungus, Poria cocos is widely used as a food supplement and as a tonic in China. High-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (HPLC-QTOF-MS/MS) was applied to identify triterpene acids in fermented mycelia of P. cocos, as well as the epidermis and inner part of natural sclerotia. A total of 19 triterpene acids were identified in fermented mycelia, whereas 31 were identified in the epidermis and 24 in the inner part. Nine triterpene acids were quantitatively determined, and the concentrations of two valuable triterpenes, dehydropachymic acid and pachymic acid, reached 1.07 mg/g and 0.61 mg/g in the fermented mycelia part, respectively, and were both significantly higher than the concentration in the two natural parts. The fermented mycelia could be a good choice for producing some target triterpene compounds and functional foods through fermentation thanks to the high concentration of some triterpene acids.

Purpose: This work aims to explore the combined effects of boundary slip and texturing on hydrodynamic journal bearings and identifies optimized slip and texture patterns to improve the performance of journal bearings. Design/methodology/approach: The quadratic programming technique is used to study the influence of boundary slip on the lubrication performance of a two-dimensional journal bearing. A numerical model is used to analyze the effect of the cylindrical texture shape on the characteristics of journal bearings. It is concluded that the combination of slip and texture can be an effective approach to improve the performance of hydrodynamic journal bearings. Findings: The results show that there is an interfacial shear stress (perfect slip surface) and that the role of the slip regime is to reduce friction. Numerical analyses indicate that the location and size of the slip and texture zone have a large effect on journal bearings. A comparison of the distribution forms of various texture–slip combinations indicates that the full texture–slip combination can prominently reduce the load-carrying capacity and that the “forward-slip backward-texture” configuration can considerably improve the performance of journal bearings. Originality/value: The combined effects of boundary slip and texture on hydrodynamic journal bearings are meticulously examined. The patterns of the slip and texture are optimized, which can substantially improve the journal bearing performance.