Layered Structure and Wear Mechanism of Concentrated Polymer Brushes.

Concentrated polymer brushes (CPBs), which are significantly denser and thicker than conventional semidilute polymer brushes, have received increasing attention in the field of tribology because of their superlow friction properties. However, despite numerous studies aimed at enhancing CPBs for mechanical applications, the relationship between the specific layered structure and lubrication mechanisms of CPBs is still not completely understood. In this study, to reveal the relationship, simultaneous time-resolved measurements of the interfacial gap, static mechanical response, and dynamic mechanical response of the CPB at the contact interface were conducted using optical interference and precise force measuring methods.

Exploiting the Synergy between Concentrated Polymer Brushes and Laser Surface Texturing to Achieve Durable Superlubricity.

Friction continues to account for the bulk of energy losses in mechanical systems, with an estimated 23% of the world's total energy consumption used to overcome friction. Concentrated polymer brushes (CPBs) have recently attracted significant scientific and industrial attention, given their ability to achieve superlubricity (i.e.

Processes of molecular adsorption and ordering enhanced by mechanical stimuli under high contact pressure.

Adsorbed molecular films, referred to as boundary films in tribology, are widely used in various industrial products as a keyway for surface functionalisation, such as lubricity, wettability, and adhesion. Because boundary films are thin nanometre-scale molecular layers and can easily be removed, their formation process cannot be elucidated in detail. In this study, to analyse the growth dynamics of boundary films, the film thickness and molecular orientation of the boundary film of a fatty acid used as an additive in rolling contact as mechanical stimuli were measured in situ.

Mechanical activities of self-beating cardiomyocyte aggregates under mechanical compression.

Since the discovery of synchronous pulsations in cardiomyocytes (CMs), electrical communication between CMs has been emphasized; however, recent studies suggest the possibility of mechanical communication. Here, we demonstrate that spherical self-beating CM aggregates, termed cardiac spheroids (CSs), produce enhanced mechanical energy under mechanical compression and work cooperatively via mechanical communication. For single CSs between parallel plates, compression increased both beating frequency and beating energy.

Effects of an mHealth App (Kencom) With Integrated Functions for Healthy Lifestyles on Physical Activity Levels and Cardiovascular Risk Biomarkers: Observational Study of 12,602 Users.

Background: Mobile health (mHealth) apps are considered to be potentially powerful tools for improving lifestyles and preventing cardiovascular disease (CVD), although only few have undergone large, well-designed epidemiological research. "kencom" is a novel mHealth app with integrated functions for healthy lifestyles such as monitoring daily health/step data, providing tailored health information, or facilitating physical activity through group-based game events. The app is linked to large-scale Japanese insurance claims databases and annual health check-up databases, thus comprising a large longitudinal cohort.

Dynamic stiction without static friction: The role of friction vector rotation.

In the textbook formulation of dry friction laws, static and dynamic friction (stick and slip) are qualitatively different and sharply separated phenomena. However, accurate measurements of stick-slip motion generally show that static friction is not truly static but characterized by a slow creep that, upon increasing tangential load, smoothly accelerates into bulk sliding. Microscopic, contact-mechanical, and phenomenological models have been previously developed to account for this behavior.

Novel friction law for the static friction force based on local precursor slipping.

The sliding of a solid object on a solid substrate requires a shear force that is larger than the maximum static friction force. It is commonly believed that the maximum static friction force is proportional to the loading force and does not depend on the apparent contact area. The ratio of the maximum static friction force to the loading force is called the static friction coefficient µM, which is considered to be a constant.

Diffuse alveolar hemorrhage following itraconazole injection.

Diffuse alveolar hemorrhage (DAH) syndrome is potentially fatal. We encountered a nearly fatal case of DAH possibly due to intravenous itraconazole (ITCZ). A 53-year-old man with chronic pulmonary aspergillosis underwent pneumonectomy of the left lung 15 days prior to the onset of DAH, which was confirmed by bronchoalveloar lavage.

Altered metabolism of dopamine in the midbrain of mice treated with tributyltin chloride via subacute oral exposure.

Tributyltin (TBT) compounds have been detected in fish and shellfish. One of the targets of TBT compounds is the central nervous system. Alterations in the levels of neurotransmitters and their metabolites, and ratios of the levels of neurotransmitters to those of their metabolites have been used as indexes of neurotoxicity.

Tributyltin (TBT) increases TNFα mRNA expression and induces apoptosis in the murine macrophage cell line in vitro.

Objective: Tributyltin (TBT) compounds have been widely used as antifouling agents for shipbottom paint. The immune system is a target of TBT intoxication. We evaluated the effects of TBT chloride in macrophages, which have critical roles in the immune system, using a murine macrophage lineage cell line, J774.