Direct Comparison of Distant Optical Lattice Clocks at the 10−1610^{-16} Uncertainty

Fiber-based remote comparison of $^{87}$Sr lattice clocks in 24 km distant laboratories is demonstrated. The instability of the comparison reaches $5\times10^{-16}$ over an averaging time of 1000 s, which is two orders of magnitude shorter than that of conventional satellite links and is limited by the instabilities of the optical clocks. By correcting the systematic shifts that are predominated by the differential gravitational redshift, the residual fractional difference is found to be $(1.0\pm7.3)\times10^{-16}$, confirming the coincidence between the two clocks. The accurate and speedy comparison of distant optical clocks paves the way for a future optical redefinition of the second

Size Distribution of Droplets in a Two Liquid-phase Mixture Compared between Liquid Spraying and Mechanical Stirring

International audienceA new liquid–liquid extraction method, called the “emulsion flow” method, is expected to realize an ideal liquid–liquid extraction by controlling the emulsion generation and separation using liquid spraying, only by solution sending. In order to understand the mechanism of emulsion control in the emulsion flow method, the size distribution of droplets in two liquid-phase mixtures was compared by using originally designed apparatuses 1) for the case of liquid spraying and 2) for the case of mechanical stirring. We demonstrated that the size distribution of droplets generated near a mixing device (a nozzle for liquid spraying or an impeller head for mechanical stirring) determines the phase-separation property

Continuous Liquid–Liquid Extraction of Uranium from Uranium-containing Wastewater Using an Organic Phase-refining-type Emulsion Flow Extractor

International audienc

Hinge Flap with Triangular Extension for Reconstruction of Pharyngocutaneous and Laryngocutaneous Fistulas

Summary:. Hinge flaps are commonly used for closure of a pharyngocutaneous fistula (PCF) or laryngocutaneous fistula. These flaps are employed to augment the wall of the pharynx or larynx, but the junction between the reconstructed and native lumens can eventually become narrow and irregular after reconstruction with standard hinge flaps. We devised a method of adding a triangular extension to the end of either or both flaps and used it to treat 3 patients. In 1 patient who developed a PCF (4 × 10 cm) after laryngectomy followed by radiotherapy, the fistula was closed with 2 hinge flaps. One flap had a caudal triangular extension. The residual skin defect was covered by a pedicled latissimus dorsi musculocutaneous flap. Another patient who developed a PCF (2.5 × 3 cm) after laryngectomy underwent 2-stage reconstruction using a buccal mucosal graft with a triangular extension, followed by 2 hinge flaps. A patient who developed an laryngocutaneous fistula (1 × 2 cm) after radiotherapy and subsequent partial laryngectomy underwent reconstruction using 2 hinge flaps, each of which had a triangular extension. The skin defect was covered by another flap. Postoperative CT or video fluoroscopic examination of swallowing showed a smooth lumen with no strictures in all 3 patients. The triangular extension of the hinge flap supplements the pharyngeal/laryngeal wall at the junction between the reconstructed and intact regions, thus avoiding postoperative stricture. Especially with PCF reconstruction, restoration of a smooth luminal surface minimizes dysphagia

Nectin-4 regulates cellular senescence-associated enlargement of cell size

Cellular senescence is defined as irreversible growth arrest induced by various stress, such as DNA damage and oxidative stress. Senescent cells exhibit various characteristic morphological changes including enlarged morphology. In our recent study, we identified Nectin-4 to be upregulated in cellular senescence by comparative transcriptomic analysis. However, there are few reports on the relationship between Nectin-4 and senescence. Therefore, we analyzed the function of Nectin-4 in senescence and its biological significance. When overexpressed with Nectin-4, the cells exhibited the enlarged cell morphology closely resembling senescent cells. In addition, the cell size enlargement during DNA damage-induced senescence was suppressed by knockdown of Nectin-4, while there were no significant changes in senescence induction. These results suggest that Nectin-4 is not involved in the regulation of senescence itself but contributes to the senescence-associated cell size increase. Furthermore, the Nectin-4-dependent cell size increase was found to be mediated by Src family kinase (SFK)/PI3 kinase (PI3K)/Rac1 pathway. To explore the functional consequences of cell size enlargement, we analyzed cell survival in Nectin-4-depleted senescent cells. Single-cell tracking experiments revealed that Nectin-4 knockdown induced apoptosis in senescent cells, and there is a strong positive correlation between cell size and survival rate. These results collectively indicate that Nectin-4 plays a causative role in the senescence-associated cell size enlargement via SFK/PI3K/Rac1, which can contribute to survival of senescent cells