Crash Performance of Inward-Inverting Composite Tubes Filled with Foam: Experimentation and Simulation.

This study presents a novel shock absorber with an inward-inverting composite foam-filled tube. Under the compression of a pressing cap and the action of an internal inversion cap, the composite tube inverted inward. During the crushing, the fronds of the composite tube compacted the foam, thereby enhancing the energy absorption. Three types of foams were applied to the absorber, and a drop-weight impact test was performed to obtain the assessment parameters. The foam increased the specific energy absorption (SEA) of the composite tube to 103 kJ/kg. Finite-element simulation based on the user-defined material subroutine was performed for the initial failure and stable stages of the crushing, and a foam model was identified through the experimental data. The mean crush force from the simulation agreed with the experimental data, and the SEA maximum error was <7%, thus validating the crush simulation of the proposed shock absorber. The development of the damage modes of the plies was analyzed based on the simulation results, showing a good energy absorption mechanism of this shock absorber.

Increasing the Compressive Strength of Helicoidal Laminates after Low-Velocity Impact upon Mixing with 0° Orientation Plies and Its Analysis.

The helicoidal laminate is a kind of nature inspired fiber reinforced polymer, and the ply orientation affects their mechanical properties for engineering structural applications. A variety of helicoidal laminates with uniform and non-linear pitch angles mixed with additional 0° plies are fabricated to investigate the impact resistance through low-velocity impact and after-impact compression tests. Additionally, helicoidal laminates with constant pitch angles, quasi-isotropic laminate, and cross-ply laminates are also fabricated for a comparative study. The impact characteristics and the compressive strength are analyzed in view of the impact model, shear stress distribution, and fracture toughness. The results suggest that 10° or 20° are the better basic pitch angles before mixing 0° orientation plies. The 0° orientation plies may affect the contact stiffness, bending stiffness, damage extent, and compressive modulus. The compressive strength reaches the highest in tests on two samples with different percentages of 0° orientation plies and ply setups. Bending stiffness also dominates the impact response. The analysis on the laminate parameters provides ideas to improve the residual strength of helicoidal laminate.

Pulmonary Daoyin as a traditional Chinese medicine rehabilitation programme for patients with IPF: A randomized controlled trial.

BACKGROUND AND OBJECTIVE: IPF is a chronic progressive lung disease in which PR provides benefit for patients. PD, a TCM PR programme, has known effectiveness in COPD, but its utility in IPF is unknown. We investigated its effectiveness and safety in patients with IPF. METHODS: A 6-month randomized controlled trial (RCT) was conducted in three Chinese clinics. Ninety-six participants diagnosed with IPF were randomly assigned to one of the three groups: the PD group received a PD programme two times a day, 5 days/week for 2 months, and the exercise group exercised via a stationary cycle ergometer, 30 min/day, 5 days/week for 2 months. Volunteers in the control group were advised to maintain their usual activities. Primary outcomes were changes from baseline in the 6MWD and HRQoL score on the SGRQ-I at 1 and 2 months (at the end of the intervention) and at 6 months (4 months after the intervention). Secondary outcomes measures included FVC, DLCO (% predicted) and the changes in mMRC. RESULTS: The 6MWD was increased in the PD group compared to exercise and control groups. 6MWD increased by 60.44 m in the PD group, 32.16 m in the exercise group and 12.42 m in controls after the 2 months of rehabilitation programme. The between-group differences in the change from baseline were 28.78 m (95% CI: 0.54 to 56.01; P = 0.044) and 48.02 m (95% CI: 23.04 to 73.00; P < 0.001) at 2 months, and 25.61 m (95% CI: -0.67 to 51.89; P = 0.058) and 50.93 m (95% CI: 25.47 to 76.40; P < 0.001) at 6 months, respectively, including a difference exceeding the MCID. There was no significant change in the SGRQ-I score, the mMRC dyspnoea score, FVC and DLCO (% predicted) in either the PD or exercise groups. CONCLUSION: Two months after the intervention, a clinically meaningful difference in 6MWD was observed favouring the PD programme. The PD programme is safe and effective as a rehabilitation intervention designed to increase exercise tolerance and is an appropriate substitute for PR.

A cyclic peptide and two pairs of norlignan lignanoside epimers from Selaginella pulvinata.

A new cyclopeptide, pulvpeptin A (1), two pairs of norlignan lignanosides, tamariscinosides G and H (2, 3), together with five known compounds (4-8) were isolated from Selaginella pulvinata. The structures were elucidated by spectroscopic data and chemical degradation. The activity of tamariscinoside G (2) was evaluated by stimulating glucose uptake in 3T3-L1 adipocytes. The results showed 1.49-fold increase in glucose uptake in 3T3-L1 cells relative to basal.

Differential microfluidic sensor on printed circuit board for biological cells analysis.

Coulter principal based resistive pulse sensor has been demonstrated as an important platform in biological cell detection and enumeration since several decades ago. Recently, the miniaturized micro-Coulter counter has attracted much attention due to its advantages in point of care diagnostics for on chip detection and enumeration of rare cells, such as circulating tumor cells. In this paper, we present a microfluidic cytometer with differential amplifier based on Coulter principle on a SU-8 coated printed circuit board substrate. The electrical current changes induced by the blockage of the microparticles in the sensing aperture are calibrated by polystyrene particles of standard size. Finally, HeLa cells are used to evaluate the performance of the proposed device for enumeration of biological samples. The proposed cytometer is built upon the cheap and widely available printed circuit board substrate and shows its great potential as personalized healthcare monitor.