Energetics of collapsible channel flow with a nonlinear fluid-beam model

We consider flow along a finite-length collapsible channel driven by a fixed upstream flux, where a section of one wall of a planar rigid channel is replaced by a plane-strain elastic beam subject to uniform external pressure. A modified constitutive law is used to ensure that the elastic beam is energetically conservative. We apply the finite element method to solve the fully nonlinear steady and unsteady systems. In line with previous studies, we show that the system always has at least one static solution and that there is a narrow region of the parameter space where the system simultaneously exhibits two stable static configurations: an (inflated) upper branch and a (collapsed) lower branch, connected by a pair of limit point bifurcations to an unstable intermediate branch. Both upper and lower static configurations can each become unstable to self-excited oscillations, initiating either side of the region with multiple static states. As the Reynolds number increases along the upper branch the oscillatory limit cycle persists into the region with multiple steady states, where interaction with the intermediate static branch suggests a nearby homoclinic orbit. These oscillations approach zero amplitude at the upper branch limit point, resulting in a stable tongue between the upper and lower branch oscillations. Furthermore, this new formulation allows us to calculate a detailed energy budget over a period of oscillation, where we show that both upper and lower branch instabilities require an increase in the work done by the upstream pressure to overcome the increased dissipation.Comment: 27 pages, 10 figures, under revie

Vortex Dynamics in Amorphous MoSi Superconducting Thin Films

Vortex dynamics in superconductors have received a great deal of attention from both fundamental and applied researchers over the past few decades. Because of its critical role in the energy relaxation process of type II superconductors, vortex dynamics have been deemed a key factor for the emerging superconducting devices, but the effect of irradiation on vortex dynamics remains unclear. With the support of electrical transport measurements under external magnetic fields and irradiation, photon effect on vortex dynamics in amorphous MoSi (a MoSi) superconducting thin films are investigated in this work. The magnetic field dependent critical vortex velocity v* derived from the Larkin Ovchinnikov model is not significantly affected by irradiation. However, vortex depinning is found to be enhanced by photon-induced reduction in potential barrier, which mitigates the adverse effect of film inhomogeneity on superconductivity in the a MoSi thin films. The thorough understanding of the vortex dynamics in a MoSi thin films under the effect of external stimuli is of paramount importance for both further fundamental research in this area and optimization of future superconducting devices

The Role of CLEC-2 and Its Ligands in Thromboinflammation

C-type lectin-like receptor 2 (CLEC-2, also known as CLEC-1b) is expressed on platelets, Kupffer cells and other immune cells, and binds to various ligands including the mucin-like protein podoplanin (PDPN). The role of CLEC-2 in infection and immunity has become increasingly evident in recent years. CLEC-2 is involved in platelet activation, tumor cell metastasis, separation of blood/lymphatic vessels, and cerebrovascular patterning during embryonic development. In this review, we have discussed the role of CLEC-2 in thromboinflammation, and focused on the recent research

Switching spectroscopic measurement of surface potentials on ferroelectric surfaces via an open-loop Kelvin probe force microscopy method

We report a method for switching spectroscopy Kelvin probe force microscopy (SS-KPFM). The method is established as a counterpart to switching spectroscopy piezoresponse force microscopy (SS-PFM) in Kelvin probe force microscopy. SS-KPFM yields quantitative information about the surface charge state during a local bias-induced polarization switching process, complementary to the electromechanical coupling properties probed via SS-PFM. Typical ferroelectric samples of a Pb-based relaxor single crystal and a BiFeO3 thin film were investigated using both methods. We briefly discuss the observed surfacecharging phenomena and their influence on the associated piezoresponse hysteresis loops.Q.L., Y.L., D.W., and R.L.W. acknowledge the support of the Australian Research Council (ARC) in the form of ARC Discovery Grants. Y.L. also acknowledges support from the ARC Future Fellowships Program

Using protection motivation theory to explain the intention to initiate human papillomavirus vaccination among men who have sex with men in China

Human papillomavirus (HPV) infection and related diseases are common among men who have sex with men (MSM). The most effective prevention is HPV vaccination. In China, however, men are not included in the HPV vaccination plan. We investigated the intention to initiate HPV vaccination and associated factors among MSM in China. Methods We surveyed 563 unvaccinated MSM aged 18 or older from six cities in China. Participants completed an electronic questionnaire about demographics, knowledge of and attitude towards HPV and HPV vaccine, intention to initiate HPV vaccination, willingness to recommend HPV vaccine to peers, feeling about government policy about HPV vaccination. We used the structural equation modeling (SEM) to analyze factors associated with HPV vaccine intention. Results The knowledge of HPV and HPV vaccine among participants was low. The mean score of knowledge about HPV and HPV vaccine was only 1.59 (range 0–11). The intention to initiate HPV vaccination within 6 months among participants was moderate (43.3% in total, 18.1% for ‘very high' and 25.2% for ‘above average')

Online Focus Group Discussions to Engage Stigmatized Populations in Qualitative Health Research: Lessons Learned

Community participation in research involving stigmatized populations has been sub-optimal, and digital tools could potentially increase participation in qualitative research. This study aims to describe the implementation of an online chat-based FGD (Focus Group Discussion) with men who have sex with men (MSM) in China as part of formative research for the PIONEER project, determine the advantages and limitations associated with the approach, and assess the feasibility of deepening community participation in STI research. Participants were involved in four days of asynchronous FGDs on sexually transmitted diseases and answered questions about the online FGD method. Online FGDs allowed us to deepen participant engagement through bidirectional communication channels. Data from online FGDs directly informed recruitment strategies and community participation for a clinical trial. Overall, 63% (29/46) of men who had never participated in offline LGBTQ + activities joined online FGDs. Many participants (89%, 41/46) noted that online FGDs were more convenient, less socially awkward, and more anonymous than in-person qualitative research. We highlighted potential risks as well as mitigation strategies when using online FGDs. Online FGDs were feasible among this group of sexual minorities and may be particularly useful in many cities where stigma limits in-person research participation