Suspended nanocrystalline diamond ridge waveguides designed for the mid-infrared

A comprehensive study and design of air-clad suspended ridge diamond waveguides for operation across the 2.5–16 µm spectral range is presented, specifically targeting nanocrystalline diamond (NCD) thin films directly grown on silicon substrates. Three film thicknesses of 520, 1000 and 2000 nm are considered, to cover overlapping sub-bands of 2.5–5, 4–9 and 8–16 µm, respectively. Within each sub-band, the waveguide dimensions for single mode quasi-TE operation are found and the waveguide material losses and bending losses are estimated at each design point. In addition, in each case the minimum required undercut depth and etch hole placement for optical isolation of the waveguide mode from the silicon substrate is also quantified. We also estimate the losses associated with scattering from surface roughness, which is an unavoidable byproduct of the NCD thin film growth process. Our results indicate that despite the relatively low film thickness-to-wavelength ratio, mechanically stable waveguides with good optical confinement and low material and bending losses can be realised to cover the full 2.5–16 µm range. In addition, scattering loss estimations predict a drastic drop in roughness-induced scattering losses above 6 µm, even for relatively rough films. In addition to highlighting the utility of suspended NCD as a versatile platform for mid-infrared integrated photonics, the approaches and results presented here can be used to inform the design of suspended air-clad waveguides in other material platforms

A SINFONI Integral Field Spectroscopy Survey for Galaxy Counterparts to Damped Lyman-alpha Systems - VI. Metallicity and Geometry as Gas Flow Probes

The use of background quasars provides a powerful tool to probe the cool gas in the circum-galactic medium of foreground galaxies. Here, we present new observations with SINFONI and X-Shooter of absorbing-galaxy candidates at z=0.7-1. We report the detection with both instruments of the H-alpha emission line of one sub-DLA at z_abs=0.94187 with log N(HI)=19.38^+0.10_-0.15 towards SDSS J002133.27+004300.9. We estimate the star formation rate: SFR=3.6+/-2.2 solar masses per year in that system. A detailed kinematic study indicates a dynamical mass M_dyn=10^9.9+/-0.4 solar masses and a halo mass M_halo=10^11.9+/-0.5 solar masses. In addition, we report the OII detection with X-Shooter of another DLA at z_abs=0.7402 with log N(HI)=20.4+/-0.1 toward Q0052+0041 and an estimated SFR of 5.3+/-0.7 solar masses per year. Three other objects are detected in the continuum with X-Shooter but the nature and redshift of two of these objects are unconstrained due to the absence of emission lines, while the third object might be at the redshift of the quasar. We use the objects detected in our whole N(HI)-selected SINFONI survey to compute the metallicity difference between the galaxy and the absorbing gas, delta_HI(X), where a positive (negative) value indicates infall (outflow). We compare this quantity with the quasar line of sight alignment with the galaxy's major (minor) axis, another tracer of infall (outflow). We find that these quantities do not correlate as expected from simple assumptions. Additional observations are necessary to relate these two independent probes of gas flows around galaxies.Comment: 16 pages, 8 figures, accepted for publication in MNRA

Pressure Gradients Driving Ion Transport in the Topside Martian Atmosphere

An edited version of this paper was published by AGU. Copyright 2019 American Geophysical Union.Magnetic and thermal pressure gradient forces drive plasma flow in the topside ionosphere of Mars. Some of this flow can contribute to ion loss from the planet and thus affect atmospheric evolution. MAVEN measurements of the magnetic field, electron density, and electron temperature, taken over a 3‐year time period, are used to obtain averaged magnetic and thermal pressures in the topside ionosphere versus altitude, solar zenith angle, and latitude. Magnetic pressures are several times greater than thermal pressures for altitudes greater than about 300 km; that is, the plasma beta is less than one. The total pressure increases with altitude in the ionosphere and decreases with increasing solar zenith angle. Using these pressure patterns in the dayside ionosphere to estimate the pressure gradient force in the fluid momentum equation, we estimate horizontal day‐to‐night plasma flow speeds of a few kilometers per second near 400 km

The gaseous mediator, hydrogen sulphide, inhibits in vitro motor patterns in the human, rat and mouse colon and jejunum

Hydrogen sulphide (H2S) has been recently proposed as a transmitter in the brain and peripheral tissues. Its role in the gastrointestinal tract is still unknown despite some data which suggest an involvement mediating smooth muscle relaxation. The aim of this study was to investigate the effect of this gas on intestinal segments from mouse jejunum and colon, and muscular strips from the human and rat colon. In isolated segments of mouse colon and jejunum, bath applied sodium hydrogen sulphide (NaHS) (a H2S donor) caused a concentration-dependent inhibition of spontaneous motor complexes (MCs) (IC50 121 μmol L-1 in the colon and 150 μmol L-1 in the jejunum). This inhibitory effect of NaHS on MCs was (i) unaffected by tetrodotoxin (TTX), capsaicin, pyridoxal-phosphate- 6-azophenyl-2',4'-disulfonate and N-nitro-l-arginine suggesting a non-neural effect and (ii) significantly reduced by apamin 3 μmol L -1. NaHS concentration-dependently inhibited the spontaneous motility in strips from human colon (IC50 261 μmol L-1) and rat colon (IC50 31 μmol L-1). The inhibitory effect of NaHS on colonic strips was (i) unaffected by the neural blocker TTX (1 μmol L-1) with IC50 183 μmol L-1 for the human colon and of 26 μmol L-1 for the rat colon and (ii) significantly reduced by glybenclamide (10 μmol L-1), apamin (3 μmol L -1) and TEA (10 mmol L-1) with IC50 values of 2464, 1307 and 2421 μmol L-1 for human strips, and 80, 167 and 674 μmol L-1 for rat strips respectively. We conclude that H 2S strongly inhibits in vitro intestinal and colonic motor patterns. This effect appears to be critically dependent on K channels particularly apamin-sensitive SK channels and glybenclamide-sensitive K (ATP) channels. © 2008 The Authors

Surface Acoustic Waves to Control Droplet Impact onto Superhydrophobic and Slippery Liquid-Infused Porous Surfaces

Superhydrophobic coatings and slippery liquid-infused porous surfaces (SLIPS) have shown their potentials in self-cleaning, anti-icing, anti-erosion, and antibiofouling applications. Various studies have been done on controlling the droplet impact on such surfaces using passive methods such as modifying the lubricant layer thickness in SLIPS. Despite their effectiveness, passive methods lack on-demand control over the impact dynamics of droplets. This paper introduces a new method to actively control the droplet impact onto superhydrophobic and SLIPS surfaces using surface acoustic waves (SAWs). In this study, we designed and fabricated SLIPS on ZnO/aluminum thin-film SAW devices and investigated different scenarios of droplet impact on the surfaces compared to those on similar superhydrophobic-coated surfaces. Our results showed that SAWs have insignificant influences on the impact dynamics of a porous and superhydrophobic surface without an infused oil layer. However, after infusion with oil, SAW energy could be effectively transferred to the droplet, thus modifying its impact dynamics onto the superhydrophobic surface. Results showed that by applying SAWs, the spreading and retraction behaviors of the droplets are altered on the SLIPS surface, leading to a change in a droplet impact regime from deposition to complete rebound with altered rebounding angles. Moreover, the contact time was reduced up to 30% when applying SAWs on surfaces with an optimum oil lubricant thickness of ∼8 μm. Our work offers an effective way of applying SAW technology along with SLIPS to effectively reduce the contact time and alter the droplet rebound angles

A scaling procedure for straightforward computation of sorptivity

This research has been supported by the Agence Nationale de la Recherche (grant no. ANR-17-CE04-010).Sorptivity is a parameter of primary importance in the study of unsaturated flow in soils. This hydraulic parameter is required to model water infiltration into vertical soil profiles. Sorptivity can be directly estimated from the soil hydraulic functions (water retention and hydraulic conductivity curves), using the integral formulation of Parlange (1975). However, calculating sorptivity in this manner requires the prior determination of the soil hydraulic diffusivity and its numerical integration between initial and final saturation degrees, which may be difficult in some situations (e.g., coarse soil with diffusivity functions that are quasi-infinite close to saturation). In this paper, we present a procedure to compute sorptivity using a scaling parameter, cp, that corresponds to the sorptivity of a unit soil (i.e., unit values for all parameters and zero residual water content) that is utterly dry at the initial state and saturated at the final state. The cp parameter was computed numerically and analytically for five hydraulic models: delta (i.e., Green and Ampt), Brooks and Corey, van Genuchten–Mualem, van Genuchten–Burdine, and Kosugi. Based on the results, we proposed brand new analytical expressions for some of the models and validated previous formulations for the other models. We also tabulated the output values so that they can easily be used to determine the actual sorptivity value for any case. At the same time, our numerical results showed that the relation between cp and the hydraulic shape parameters strongly depends on the chosen model. These results highlight the need for careful selection of the proper model for the description of the water retention and hydraulic conductivity functions when estimating sorptivity.French National Research Agency (ANR) European Commission ANR-17-CE04-01

MiR-144: A new possible therapeutic target and diagnostic/prognostic tool in cancers

MicroRNAs (miRNAs) are small and non-coding RNAs that display aberrant expression in the tissue and plasma of cancer patients when tested in comparison to healthy individuals. In past decades, research data proposed that miRNAs could be diagnostic and prognostic biomarkers in cancer patients. It has been confirmed that miRNAs can act either as oncogenes by silencing tumor inhibitors or as tumor suppressors by targeting oncoproteins. MiR-144s are located in the chromosomal region 17q11.2, which is subject to significant damage in many types of cancers. In this review, we assess the involvement of miR-144s in several cancer types by illustrating the possible target genes that are related to each cancer, and we also briefly describe the clinical applications of miR-144s as a diagnostic and prognostic tool in cancers

Squamous cell carcinoma of the tonsil managed by conventional surgery and postoperative radiation

BACKGROUND: The purpose of this study was to report the long-term outcome of patients with squamous cell cancer (SCC) of the tonsil managed by surgery followed by postoperative radiotherapy (PORT). METHODS: Eighty-eight patients treated between 1985 and 2005 were analyzed. Overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) were determined by the Kaplan-Meier method. Factors predictive of outcome were determined by univariate and multivariate analysis. RESULTS: Forty-eight percent of patients had T3 to T4 disease and 75% had a positive neck. Five-year OS, DSS, and RFS were 66%, 82%, and 80%, respectively. The status of the neck was not predictive of outcome (DSS 80% for N0 vs 82% for N+; p = .97). Lymphovascular invasion was an independent predictor of OS, DSS, and RFS on multivariate analysis. CONCLUSION: Lymphovascular invasion but not pathological stage of the neck is an independent predictor of outcome in patients with tonsillar SCC. (c) 2014 Wiley Periodicals, Inc. Head Neck, 2014

Genesis of the dusty Universe: modeling submillimetre source counts

We model the evolution of IR galaxies using a phenomenological approach to match the observed source counts at different IR wavelengths. We introduce a new algorithm for reproducing source counts based on direct integration of probability distributions rather than Monte-Carlo sampling. We construct a simple model for the evolution of the luminosity function and the colour distribution of IR galaxies which utilizes a minimum number of free parameters. Moreover we analyze how each of these parameters is constrained by observational data. The model is based on pure luminosity evolution and adopts the Dale & Helou SED templates. We find that the 850um source counts and their redshift distribution depend strongly on the shape of the luminosity evolution function, but only weakly on the details of the SEDs. We derive the best-fit evolutionary model using the 850um counts and redshift distribution as constraints. Moreover our best-fit shows a flattening of the faint end of the luminosity function towards high redshifts and requires a colour evolution which implies the typical dust temperatures of objects with the same luminosities to decrease with redshift. We compare our best-fit model to observed source counts at shorter and longer wavelengths which indicates our model reproduces the 70um and 1100um source counts remarkably well, but under-produces the counts at intermediate wavelengths. Analysis reveals that the discrepancy arises at low redshifts, indicating that revision of the adopted SED library towards lower dust temperatures (at a fixed infrared luminosity) is required. This modification is equivalent to a population of cold galaxies existing at low redshifts, as also indicated by recent Herschel results, which are underrepresented in IRAS sample. We show that the modified model successfully reproduces the source counts in a wide range of IR and submm wavelengths.Comment: 21 pages, 11 figures, 2 tables. Accepted for publication in MNRAS. Supplementary information could be found at http://www.strw.leidenuniv.nl/genesis