Retro-dihydrochalcones from the resin of Daemonorops draco and their inhibitory activities against renal fibrosis.

Daedracoflavan A-E (1-5), five new flavonoids were isolated from the resin of Daemonorops draco. Their structures including absolute configurations were established by using spectroscopic and computational methods. All the compounds are new chalcones with the same retro-dihydrochalcone skeleton. Compound 1 features the presence of a cyclohexadienone unit originating from a benzene ring, and the ketone group of C-9 reduced to a hydroxyl group. The bioactivity of all isolated compounds was evaluated in kidney fibrosis and found that compound 2 could dose-dependently inhibit the expression of fibronectin, collagen I, and α-SMA in TGF-ß1-induced rat kidney proximal tubular cells (NRK-52E). Interestingly, the replacement of a proton by a hydroxyl group at C-4' seems to play a crucial role in anti-renal fibrosis activity.

A novel L-shaped linear ultrasonic motor operating in a single resonance mode.

In this study, a large thrust linear ultrasonic motor using an L-shaped stator is described. The stator is constructed by two mutually perpendicular rectangular plate vibrators, one of which is mounted in parallel with the slider to make the motor structure to be more compact. The symmetric and antisymmetric modes of the stator based on the first order bending vibration of two vibrators are adopted, in which each resonance mode is assigned to drive the slider in one direction. The placement of piezoelectric ceramics in a stator could be determined by finite element analysis, and the influence of slots in the head block on the vibration amplitudes of driving foot was studied as well. Three types of prototypes (non-slotted, dual-slot, and single-slot) were fabricated and experimentally investigated. Experimental results demonstrated that the prototype with one slot exhibited the best mechanical output performance. The maximum loads under the excitation of symmetric mode and antisymmetric mode were 65 and 90 N, respectively.

A novel Π -type linear ultrasonic motor driven by a single mode.

In order to meet the demand of a linear ultrasonic motor with large thrust in narrow space, a novel Π-type linear ultrasonic motor with double driving feet is proposed. In this paper, the structure of a stator is designed. The working mode and structure size are determined by finite element simulation. To amplify the amplitude of driving foot, an optimization design for the stator is performed. After that, a novel pre-load device that separates from the stator is put forward, which can not only improve the output but also help to improve the operation stability and prolong the life of motor. Additionally, a prototype of the proposed motor with the novel pre-load device was fabricated and the performance tests were implemented. The experimental results show that the suggested motor has structural stability and high dynamic performance, such as a no-load speed of 273 mm/s and 238 mm/s in two directions, corresponding to a maximal thrust of 80 N and 110 N.

A real explosion: the requirement of steam explosion pretreatment.

The severity factor is a common term used in steam explosion (SE) pretreatment that describes the combined effects of the temperature and duration of the pretreatment. However, it ignores the duration of the explosion process. This paper describes a new parameter, the explosion power density (EPD), which is independent of the severity factor. Furthermore, we present the adoption of a 5m(3) SE model for a catapult explosion mode, which completes the explosion within 0.0875 s. The explosion duration ratio of this model to a conventional model of the same volume is 1:123. The comparison between the two modes revealed a qualitative change by explosion speed, demonstrating that this real explosion satisfied the two requirements of consistency, and suggested a guiding mechanism for the design of SE devices.