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Cilia and flagella are beating rod-like organelles that enable the directional movement of microorganisms in fluids and fluid transport along the surface of biological organisms or inside organs. The molecular motor axonemal dynein drives their beating by interacting with microtubules. Constructing synthetic beating systems with axonemal dynein capable of mimicking ciliary beating still represents a major challenge. Here, the bottom-up engineering of a sustained beating synthoneme consisting of a pair of microtubules connected by a series of periodic arrays of approximately eight axonemal dyneins is reported. A model leads to the understanding of the motion through the cooperative, cyclic association-dissociation of the molecular motor from the microtubules. The synthoneme represents a bottom-up self-organized bio-molecular machine at the nanoscale with cilia-like properties.

We describe a case of successful veno-arterial extracorporeal membrane oxygenation (VA-ECMO)-supported percutaneous coronary intervention (PCI) for multivessel coronary artery disease in a patient considered as a candidate for transcatheter aortic valve replacement (TAVR). VA-ECMO-supported PCI for patients with severe aortic valve stenosis might be a feasible option before TAVR.

Intercellular adhesion strengths between two kinds of murine breast cancer cells with different malignancies were measured quantitatively using a metal cup-attached chip with atomic force microscopy (AFM). The cup-attached chip was used to approach a cell, pick it up, and then approach another cell, and the adhesion strengths were measured according to the contact time of the cells between 0 to 60 s. Separation work was used as a parameter for quantitative comparisons of the strengths. As a result, the work of a highly metastatic cancer cell (FP10SC2) was greater than a low metastatic cancer cell (4T1-LM) throughout all contact times examined. Adhesion was analyzed from a point of a view of binding kinetics of receptors on cells, and two possibilities were found: one was the number of cell adhesive receptors increased, and the other was the work to separate single molecular binding increased with increasing cancer cell malignancy. These results indicated quantitative measurements of intercellular adhesion strengths using AFM yielded information to understand the mechanism of the cancer progression from a new perspective.

Leading-edge (LE) noise is a common source of broadband noise for fans that can be suppressed using appended LE serrations. We conduct an integrated study of the morphological effects of interval, length, and inclination angle of owl-inspired LE serrations on the aeroacoustic characteristics of a mixed flow fan using experiments, computational fluid dynamics (CFD), and the Ffowcs Williams–Hawkings (FWH) analogy. A novel method for surface noise strength (SNS) visualization was developed based on the FWH analogy with large-eddy simulations to accurately quantify the spatial distributions of acoustic sources. A CFD-informed index is proposed to evaluate the severity of flow separation with the pressure gradient and verified to be effective in examining the chord-wise separation. Acoustic measurements show the robust trade-off solving capability of the serrations under various morphologies, and the SNS visualizations indicate that the separation-induced LE noise is suppressed considerably. One-third octave analyses suggest that extending serration length can lower separation noise more effectively than shrinking the interval over 100–3000 Hz. A smaller interval is more desirable while an optimal length exists in association with tonal noise. Moreover, small inclination angles ([Formula: see text]) enable the deceleration of oncoming flows with stagnation relieved, and consequently, further suppress the LE noise, by a flow-buffering effect. Heavy inclination angles ([Formula: see text]) induce an additional tip vortex, causing high-coherence turbulence impingement noise and resulting in a drastic increase in broadband noise at frequencies exceeding 4000 Hz. Our study, thus, clarifies the morphological effects of LE serrations on aeroacoustic signatures of rotary devices while providing useful methods for acoustic analyses.

The influence of nivolumab on intercellular adhesion forces between T cells and cancer cells was evaluated quantitatively using atomic force microscopy (AFM). Two model T cells, one expressing high levels of programmed cell death protein 1 (PD-1) (PD-1high Jurkat) and the other with low PD-1 expression levels (PD-1low Jurkat), were analyzed. In addition, two model cancer cells, one expressing programmed death-ligand 1 (PD-L1) on the cell surface (PC-9, PD-L1+) and the other without PD-L1 (MCF-7, PD-L1−), were also used. A T cell was attached to the apex of the AFM cantilever using a cup-attached AFM chip, and the intercellular adhesion forces were measured. Although PD-1high T cells adhered strongly to PD-L1+ cancer cells, the adhesion force was smaller than that with PD-L1− cancer cells. After the treatment of PD-1high T cells with nivolumab, the adhesion force with PD-L1+ cancer cells increased to a similar level as with PD-L1− cancer cells. These results can be explained by nivolumab influencing the upregulation of the adhesion ability of PD-1high T cells with PD-L1+ cancer cells. These results were obtained by measuring intercellular adhesion forces quantitatively, indicating the usefulness of single-cell AFM analysis.

In this paper, reduction effect of a common-mode filter is discussed. When the performance of a common-mode filter is evaluated, it is necessary to consider not only S CC21 but also S CD21 . Using these two parameters, the common-mode current flowing on the secondary side of the common-mode filter was formulated. Common-mode current is a summation of two causes: common-mode transmission and differential mode conversion from a signal source. The common-mode current depends on not only the phase relationship between S CC21 and S CD21 of the common-mode filter but also the phase relationship between the differential mode and the common mode of the signal source. Even if the same common-mode filter is used on a differential signaling system, the common-mode current increases or decreases depending on the phase of the differential mode voltage and the common-mode voltage at the signal source.

The common-mode filter (CMF) is a key device for suppressing emissions radiated from telecommunication cables. Recent serial interfaces deliver the necessity of considering that common-mode (CM) disturbances are converted from the differential mode (DM) telecommunication signals by a CMF. To examine this phenomenon, this study investigated the $S_{\text{cd}21}$ characteristic, which is one of the mixed-mode S-parameters. Two types of CMFs whose $S_{\text{cd}21}$ were different were examined. A signal was supplied to an unshielded twisted pair (UTP) cable through the CMF. The emission from the cable was measured using a setup complying with CISPR 25. Then, the relationship between the ratio of CM to DM signals and the emission level was investigated. The results showed that the emission level decreased as a result of employing the lower $S_{\text{cd}21}$ CMF and that the emission level was linearly proportional to the ratio of the CM to DM signals. The results indicate that ${S}_{\text{cd}21}$ is an essential parameter with which to evaluate CMFs used in telecommunication ports of serial interfaces.

There is an increasing need in industry for noise reduction in fans. Inspired by owls' silent flight, we propose four owl-inspired blade designs for a mixed-flow fan to examine whether leading-edge (LE) and/or trailing-edge (TE) serrations can resolve the tradeoff between sound suppression and aerodynamic performance. We investigate the blades' aeroacoustic characteristics through various experimental methods and large-eddy simulation (LES)-based numerical analyses. Experimental results suggest that 'slotted', simply-fabricated LE serrations can achieve a lowering of the noise level while sustaining the aerodynamic performance of the fan, whereas TE serrations fail. In addition, the inclination angle can improve LE serration performance in aeroacoustic and aerodynamic performance with a reduction in the specific noise level by around 1.4 dB. LES results and noise spectral analysis indicate that the LE serrations can suppress flow separation, reducing the broadband noise at low-to-middle frequencies (40-4k Hz). This passive-flow-control mechanism, likely due to local higher incidence angles associated with LE serrations, is capable of alleviating the intensive pressure gradient while suppressing wall-pressure fluctuations over the LE region, hence weakening the Kelvin-Helmholtz instability. The tonal noise also shows a marked reduction at the highest peak frequency associated with fan-vane interaction. Moreover, we find that the high-frequency noise by-product radiates mainly from the LE serrations andsurroundings, due to the small eddies broken up when the vortical flows pass through the LE serrations. Our results demonstrate that the biomimetic design of the LE serrations can facilitate the break-up of LE vortices passively and effectively without negatively impacting aerodynamic performance, which can be utilized as an effective device to improve the aeroacoustic performance of fan blades.

The contribution of secretions from tumor-associated macrophage (TAM)-like cells to the stimulation of mechanical property changes in murine breast cancer cells was studied using an in vitro model system. A murine breast cancer cell line (FP10SC2) was stimulated by adding macrophage (J774.2) cultivation medium containing stimulation molecules secreted from the macrophages, and changes in mechanical properties were compared before and after stimulation. As a result, cell elasticity decreased, degradation ability of the extracellular matrix increased, and the expression of plakoglobin was upregulated. These results indicate that cancer cell malignancy is upregulated by this stimulation. Moreover, changes in intercellular adhesion strengths between pairs of cancer cells were measured before and after stimulation using atomic force microscopy (AFM). The maximum force required to separate cells was increased by stimulation with the secreted factors. These results indicate the possibility that TAMs cause changes in the mechanical properties of cancer cells in tumor microenvironments, and in vitro measurements of mechanical property changes in cancer cells will be useful to study interactions between cells in tumor microenvironments.

Bispecific antibodies (bsAbs) are a promising engineered antibody format; thus, technologies for the fabrication and evaluation of functional bsAbs are attracting increasing attention. Here, based on atomic force microscopy (AFM) force-sensing integrated with a metal cup-attached AFM chip (cup-chip) to ensure efficient capture of a target cell on a cantilever, we established a novel method for measuring cross-linking ability that is correlated with the cytotoxicities of bsAbs targeting two cells. We previously reported that domain rearrangements of bsAbs affected their cytotoxicities; however, no differences in cross-linking ability for soluble antigens were observed by surface plasmon resonance. We predicted that there would be differences in molecular configurations to avoid steric hindrance in the cross-linking of the two whole target cells. A picked-up T cell lymphoma cell on the cantilever using a cup-chip was moved to approach a cancer cell adhered to a dish, and force-curve measurements were performed. The resulting forces mediated by the cross-linking of bsAbs with different domain orders were well-correlated with their cytotoxicities. The AFM force-sensing method established herein may reflect steric hindrance of intercellular cross-linking, and thus has the potential to evaluate the net function of bsAbs and contribute to the generation of functional bsAbs.

In eukaryotic cilia and flagella, various types of axonemal dyneins orchestrate their distinct functions to generate oscillatory bending of axonemes. The force-generating mechanism of dyneins has recently been well elucidated, mainly in cytoplasmic dyneins, thanks to progress in single-molecule measurements, X-ray crystallography, and advanced electron microscopy. These techniques have shed light on several important questions concerning what conformational changes accompany ATP hydrolysis and whether multiple motor domains are coordinated in the movements of dynein. However, due to the lack of a proper expression system for axonemal dyneins, no atomic coordinates of the entire motor domain of axonemal dynein have been reported. Therefore, a substantial amount of knowledge on the molecular architecture of axonemal dynein has been derived from electron microscopic observations on dynein arms in axonemes or on isolated axonemal dynein molecules. This review describes our current knowledge and perspectives of the force-generating mechanism of axonemal dyneins in solo and in ensemble.

The classical self-oscillations can collapse merely due to their mutual couplings. We investigate this oscillation collapse in quantum van der Pol oscillators. For a pair of quantum oscillators, the steady-state mean phonon number is shown to be lower than in the corresponding classical model with a Gaussian white noise that mimics quantum noise. We further show within the mean-field theory that a number of globally coupled oscillators undergo a transition from the synchronized periodic motion to the collective oscillation collapse. A quantum many-body simulation suggests that the increase in the number of oscillators leads to a lower steady-state mean phonon number, bounded below by the mean-field result., 7 pages, 4 figures

Intercellular adhesion strengths of murine breast cancer cells with different malignancies (FP10SC2, highly metastatic and 4T1-LM weakly metastatic) with murine endothelial cells (BMEC) were measured using a cup-attached chip by atomic force microscopy with contact time of the cells between 0 and 60 s. The work required to separate FP10SC2 from a BMEC was larger than that to separate 4T1-LM after short contact times. In addition, cells were greatly elongated at the separation between FP10SC2 and BMEC. From these results, we suggested a model that the adhesion properties of cancer cells measured in this study were representations of detached cancer cells as circulating tumor cells, and highly metastatic cancer cells strongly adhered to endothelial cells with large deformation in floating conditions. These results indicated that our method is useful to study the processes of cancer cell metastasis with respect to intercellular adhesion.

Cell adhesion strengths to various substrates were quantitatively measured using atomic force microscopy (AFM). A cup-shaped metal hemisphere was attached to the apex of the AFM cantilever, the "cup-chip" approached a cell (FP10SC2) to pick it up, the captured cell approached any one of six different substrates [gold (Au), nickel (Ni), bovine serum albumin (BSA), an amino group (NH2), poly(tetrafluoroethylene) (PTFE), and structured PTFE (sPTFE)], and the cell adhesion strength at the initial contact period was evaluated by detaching the cell from the substrate. The results obtained showed that the force needed to detach the cell from the NH2 substrate was more than 3-fold larger than that of metal substrates (Au and Ni), more than 15-fold larger than that of biochemically treated substrates (BSA), and more than 20-fold larger than that of hydrophobic substrates (PTFE and sPTFE). Using differences in adhesion strengths, a cell on a sPTFE substrate was picked up using a BSA-coated cup-chip, placed on a NH2 substrate, repeating this cell manipulation five times, and line patterning of cells was achieved. These results indicate that measurements of cell adhesion strength are fundamental to fabricate desired cell networks and the cup-chip is a useful tool for achieving easy cell manipulation.