Design and Characterization of a Non-Linear Variable Inerter in Vehicle Suspension System

Inerter is a two-terminal component in suspension system such that the force at the two terminals is directly proportional to the relative acceleration of these two points. Studies have shown that the inerter can provide satisfactory vibration isolation for a number of suspension applications, including train suspension, building suspension and vehicle suspension. In the context of vehicle suspension, the existing passive inerter has been shown to provide benefits to vehicle dynamics performance measures, such as ride comfort and road holding ability. However, a basic passive inerter has fixed characteristic, and hence its potential is limited. This study overcome this limitation by incorporating variable inertia in inerter flywheel, however its non-linear characteristic needs to be determined. The method of achieving variable inertia in inerter flywheel is through introduction of movable masses or sliders attached with springs into inerter flywheel. The change of moment of inertia is caused by position change of sliders due to centrifugal force when the flywheel is rotating. Results showed that the proposed variable inerter exhibits a non-linear force-acceleration relationship with respect to its operating rotational speed. A vehicle suspension system equipped with a variable inerter is also able to further reduce vertical vehicle body acceleration and vehicle’s dynamic tire load when compared with vehicle suspension system without inerter and equipped with a passive inerter, which indirectly relates to a better vehicle ride and handling performance improvements. Hence, it can be proved that the proposed variable inerter is better than a passive inerter and is able to provide better ride comfort and road holding ability to a vehicle

Design and Characterization of a Non-Linear Variable Inerter in Vehicle Suspension System

Inerter is a two-terminal component in suspension system such that the force at the two terminals is directly proportional to the relative acceleration of these two points. Studies have shown that the inerter can provide satisfactory vibration isolation for a number of suspension applications, including train suspension, building suspension and vehicle suspension. In the context of vehicle suspension, the existing passive inerter has been shown to provide benefits to vehicle dynamics performance measures, such as ride comfort and road holding ability. However, a basic passive inerter has fixed characteristic, and hence its potential is limited. This study overcome this limitation by incorporating variable inertia in inerter flywheel, however its non-linear characteristic needs to be determined. The method of achieving variable inertia in inerter flywheel is through introduction of movable masses or sliders attached with springs into inerter flywheel. The change of moment of inertia is caused by position change of sliders due to centrifugal force when the flywheel is rotating. Results showed that the proposed variable inerter exhibits a non-linear force-acceleration relationship with respect to its operating rotational speed. A vehicle suspension system equipped with a variable inerter is also able to further reduce vertical vehicle body acceleration and vehicle’s dynamic tire load when compared with vehicle suspension system without inerter and equipped with a passive inerter, which indirectly relates to a better vehicle ride and handling performance improvements. Hence, it can be proved that the proposed variable inerter is better than a passive inerter and is able to provide better ride comfort and road holding ability to a vehicle

The Amplitude of Non-Equilibrium Quantum Interference in Metallic Mesoscopic Systems

We study the influence of a DC bias voltage V on quantum interference corrections to the measured differential conductance in metallic mesoscopic wires and rings. The amplitude of both universal conductance fluctuations (UCF) and Aharonov-Bohm effect (ABE) is enhanced several times for voltages larger than the Thouless energy. The enhancement persists even in the presence of inelastic electron-electron scattering up to V ~ 1 mV. For larger voltages electron-phonon collisions lead to the amplitude decaying as a power law for the UCF and exponentially for the ABE. We obtain good agreement of the experimental data with a model which takes into account the decrease of the electron phase-coherence length due to electron-electron and electron-phonon scattering.Comment: New title, refined analysis. 7 pages, 3 figures, to be published in Europhysics Letter

Maternal anxiety about prenatal screening for group B streptococcus disease and impact of positive colonization results

Abstract Objective: Universal screening for colonization by group B streptococcus (GBS) is the recommended strategy to reduce incidence of colonization in newborns and prevent neonatal GBS-related disease. This study was designed to assess maternal anxiety levels about prenatal screening and psychological impact of positive colonization test results. Methods: A total of 71 women who screened positively for GBS colonization and 112 screen-negative women (controls) were recruited. Anxiety levels were measured by the Spielberger State Trait-anxiety Inventory just before the GBS screening test, 1-week after testing, and 1-week after delivery. After delivery of their infants, all participants were asked to respond with a Likert scale line about attitudes toward being tested for GBS colonization. Results: Women with GBS colonization reported significantly greater psychological distress on state-anxiety scores after the full report was received. The trait-and state-anxiety scores before GBS screen testing and after delivery did not differ between the groups. Both groups of women were strongly positive about being screened for GBS in the current pregnancy and in future pregnancies. Conclusion: Women with GBS colonization did not have a sustained increase in anxiety; therefore, clinician concerns about causing maternal anxiety should not be an impediment to test for GBS.

The expression of RUNX3 in colorectal cancer is associated with disease stage and patient outcome

RUNX3 is believed to have tumour suppressor properties in several cancer types. Inactivation of RUNX3 has been shown to occur by methylation-induced transcriptional silencing and by mislocalization of the protein to the cytoplasm. The aim of this study was to examine the clinical significance of RUNX3 expression in a large series of colorectal cancers using immunohistochemistry and tissue arrays. With advancing tumour stage, expression of RUNX3 in the nucleus decreased, whereas expression restricted to the cytoplasmic compartment increased. Nuclear RUNX3 expression was associated with significantly better patient survival compared to tumours in which the expression of RUNX3 was restricted to the cytoplasm (P=0.025). These results support a role for RUNX3 as a tumour suppressor in colorectal cancer

Efficacy and tolerability of trastuzumab emtansine in advanced human epidermal growth factor receptor 2–positive breast cancer

© 2018, Hong Kong Academy of Medicine Press. All rights reserved. Introduction: The management of human epidermal growth factor receptor 2 (HER2)–positive breast cancer has changed dramatically with the introduction and widespread use of HER2-targeted therapies. There is, however, relatively limited real-world information about the effectiveness and safety of trastuzumab emtansine (T-DM1) in Hong Kong Chinese patients. We assessed the efficacy and toxicity profiles among local patients with HER2-positive advanced breast cancer who had received T-DM1 therapy in the second-line setting and beyond. Methods: This retrospective study involved five local centres that provide service for over 80% of the breast cancer population in Hong Kong. The study period was from December 2013 to December 2015. Patients were included if they had recurrent or metastatic histologically confirmed HER2+ breast cancer who had progressed after at least one line of anti-HER2 therapy including trastuzumab. Patients were excluded if they received T-DM1 as first-line treatment for recurrent or metastatic HER2+ breast cancer. Patient charts including biochemical and haematological profiles were reviewed for background information, T-DM1 response, and toxicity data. Adverse events were documented during chemotherapy and 28 days after the last dose of medication. Results: Among 37 patients being included in this study, 28 (75.7%) had two or more lines of anti-HER2 agents and 26 (70.3%) had received two or more lines of palliative chemotherapy. Response assessment revealed that three (8.1%) patients had a complete response, eight (21.6%) a partial response, 11 (29.7%) a stable disease, and 12 (32.4%) a progressive disease; three patients could not be assessed. The median duration of response was 17.3 (95% confidence interval, 8.4-24.8) months. The clinical benefit rate (complete response + partial response + stable disease, ≥12 weeks) was 37.8% (95% confidence interval, 22.2%-53.5%). The median progression-free survival was 6.0 (95% confidence interval, 3.3-9.8) months and the median overall survival had not been reached by the data cut-off date. Grade 3 or 4 toxicities included thrombocytopaenia (13.5%), raised alanine transaminase (8.1%), anaemia (5.4%), and hypokalaemia (2.7%). No patient died as a result of toxicities. Conclusions: In patients with HER2-positive advanced breast cancer who have been heavily pretreated with anti-HER2 agents and cytotoxic chemotherapy, T-DM1 is well tolerated and provided a meaningful progression-free survival of 6 months and an overall survival that has not been reached. Further studies to identify appropriate patient subgroups are warranted.Link_to_subscribed_fulltex

Macroscopic transport by synthetic molecular machines

Nature uses molecular motors and machines in virtually every significant biological process, but demonstrating that simpler artificial structures operating through the same gross mechanisms can be interfaced with—and perform physical tasks in—the macroscopic world represents a significant hurdle for molecular nanotechnology. Here we describe a wholly synthetic molecular system that converts an external energy source (light) into biased brownian motion to transport a macroscopic cargo and do measurable work. The millimetre-scale directional transport of a liquid on a surface is achieved by using the biased brownian motion of stimuli-responsive rotaxanes (‘molecular shuttles’) to expose or conceal fluoroalkane residues and thereby modify surface tension. The collective operation of a monolayer of the molecular shuttles is sufficient to power the movement of a microlitre droplet of diiodomethane up a twelve-degree incline.