The photolysis of FeOH and its effect on the bottomside of the mesospheric Fe layer

Metal layers in the upper mesosphere and lower thermosphere are created through meteoric ablation. They are important for understanding the temperature structure, dynamics and chemistry of this atmospheric region. Recent lidar observations have shown a regular downward extension of the Fe layer bottomside which correlates with solar radiation. In this study we combine lidar observations, quantum chemical calculations and model simulations to show that this bottomside extension is primarily caused by photolysis of FeOH. We determine the photolysis rate to be J(FeOH)=(6±3)×10−3s−1. We also show that the reaction FeOH+H→FeO+H2 is slower at mesospheric temperatures than previous estimates. With these updated rate coefficients, we are able to significantly improve the modelling of the Fe layer bottomside. The calculations further show the nearly complete depletion of FeOH during sunlit periods. This may have implications for cloud nuclei in the middle atmosphere

Momentum-resolved resonant inelastic soft X-ray scattering (qRIXS) endstation at the ALS

A momentum resolved resonant inelastic X-ray scattering (qRIXS) experimental station with continuously rotatable spectrometers and parallel detection is designed to operate at different beamlines at synchrotron and free electron laser (FEL) facilities. This endstation, currently located at the Advanced Light Source (ALS), has five emission ports on the experimental chamber for mounting the high-throughput modular soft X-ray spectrometers (MXS) [24]. Coupled to the rotation from the supporting hexapod, the scattered X-rays from 27.5° (forward scattering) to 152.5° (backward scattering) relative to the incident photon beam can be recorded, enabling the momentum-resolved RIXS spectroscopy. The components of this endstation are described in details, and the preliminary RIXS measurements on highly oriented pyrolytic graphite (HOPG) reveal the low energy vibronic excitations from the strong electron-phonon coupling at C K edge around σ* band. The grating upgrade option to enhance the performance at low photon energies is presented and the potential of this spectroscopy is discussed in summary

Internal in-service inspection of the floor and walls of oil, petroleum, and chemical storage tanks with a mobile robot

The RobTank mobile robot can enter oil and chemical storage tanks through 300 mm or more diameter openings in the roof. It performs in-service inspection of the floor and walls while submerged in liquid thereby saving the cost of emptying, cleaning, and manually inspecting the tank. A navigation system keeps track of position and orientation within the tank. An array of ultrasonic wheel probes and two bulk-wave rotating probes look for corrosion thinning on the floor and walls up to half a metre ahead and under inaccessible floor areas. Obstacles such as drain sumps, heating coils, etc. are detected and avoided

Harnessing liquid-in-liquid printing and micropatterned substrates to fabricate 3-dimensional all-liquid fluidic devices

Systems comprised of immiscible liquids held in non-equilibrium shapes by the interfacial assembly and jamming of nanoparticle−polymer surfactants have significant potential to advance catalysis, chemical separations, energy storage and conversion. Spatially directing functionality within them and coupling processes in both phases remains a challenge. Here, we exploit nanoclay−polymer surfactant assemblies at an oil−water interface to produce a semi-permeable membrane between the liquids, and from them all-liquid fluidic devices with bespoke properties. Flow channels are fabricated using micropatterned 2D substrates and liquid-in-liquid 3D printing. The anionic walls of the device can be functionalized with cationic small molecules, enzymes, and colloidal nanocrystal catalysts. Multi-step chemical transformations can be conducted within the channels under flow, as can selective mass transport across the liquid−liquid interface for in-line separations. These all-liquid systems become automated using pumps, detectors, and control systems, revealing a latent ability for chemical logic and learning

The Buckling Spectra of Nanoparticle Surfactant Assemblies

Fine control over the mechanical properties of thin sheets underpins transcytosis, cell shape, and morphogenesis. Applying these principles to artificial, liquid-based systems has led to reconfigurable materials for soft robotics, actuation, and chemical synthesis. However, progress is limited by a lack of synthetic two-dimensional membranes that exhibit tunable mechanical properties over a comparable range to that seen in nature. Here, we show that the bending modulus, B, of thin assemblies of nanoparticle surfactants (NPSs) at the oil–water interface can be varied continuously from sub-kBT to 106kBT, by varying the ligands and particles that comprise the NPS. We find extensive departure from continuum behavior, including enormous mechanical anisotropy and a power law relation between B and the buckling spectrum width. Our findings provide a platform for shape-changing liquid devices and motivate new theories for the description of thin-film wrinkling

Semi-individualised Chinese medicine treatment as an adjuvant management for diabetic nephropathy: a pilot add-on, randomised, controlled, multicentre, open-label pragmatic clinical trial

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Filamin-A Regulates Neutrophil Uropod Retraction through RhoA during Chemotaxis

Filamin-A (FLNa) has been shown to be a key cross-linker of actin filaments in the leading edge of a motile melanoma cell line, however its role in neutrophils undergoing chemotaxis is unknown. Using a murine transgenic model in which FLNa is selectively deleted in granulocytes, we report that, while neutrophils lacking FLNa show normal polarization and pseudopod extension, they exhibit obvious defects in uropod retraction. This uropod retraction defect was found to be a direct result of reduced FLNa mediated activation of the small GTPase RhoA and myosin mediated actin contraction in the FLNa null cells. This results in a neutrophil recruitment defect in FLNa null mice. The compensatory increase in FLNb levels that was observed in the FLNa null neutrophils may be sufficient to compensate for the lack of FLNa at the leading edge allowing for normal polarization, however this compensation is unable to regulate RhoA activated tail retraction at the rear of the cell