Search results for "7(15)"

Correlation of " in vivo" microcirculation and degeneration of the basal cells of the epithelium in lingual lichen planus

2010

Background: Oral lichen planus is an inflammatory chronic disease with an autimmune pathogenesis and unknown etiology that affects oral mucosa, with or without the involvement of the skin and other mucous membranes. The principal histological characteristics are the degeneration of the basal cell layer and the abnormal infiltration of inflammatory cells into the subepithelial layer of connective tissue. Objectives: This study is aimed to appraise if lingual lichen planus (LLP) is sustained by alteration of the oral microcirculation and if this abnormal vascularisation increases the degeneration of basal keratinocytes and the disruption of the basement membrane. Materials and Methods: Fiftee…

Anxiety and facial self-contacts: possible impact on COVID-19 transmission in dental practice

2021

Abstract Background The purpose was to analyse the associations between dental and trait anxiety, fear of COVID-19 and the duration and frequency of spontaneous hand-to-face contact (self-contact). Methods A cross-sectional design was carried out with 128 adult patients from four dental clinics in Madrid, during the confinement, from March 15 to May 15. The patients’ movements in the waiting room were monitored with Microsoft Kinect Software, also completed the Trait anxiety subscale of the STAI, the COVID-19 Fear and the S-DAI questionnaire. Results Associations were observed between the duration and frequency of facial, mask and eye contact with trait anxiety and dental fear was determine…

Dental Implants in the Third Millennium

2018

The novel HALO mini-DOAS instrument: inferring trace gas concentrations from airborne UV/visible limb spectroscopy under all skies using the scaling …

2017

Abstract. We report on a novel six-channel optical spectrometer (further on called mini-DOAS instrument) for airborne nadir and limb measurements of atmospheric trace gases, liquid and solid water, and spectral radiances in the UV/vis and NIR spectral ranges. The spectrometer was developed for measurements from aboard the German High-Altitude and Long-Range (HALO) research aircraft during dedicated research missions. Here we report on the relevant instrumental details and the novel scaling method used to infer the mixing ratios of UV/vis absorbing trace gases from their absorption measured in limb geometry. The uncertainties of the scaling method are assessed in more detail than before for …

Design, construction and commissioning of the Braunschweig Icing Wind Tunnel

2018

Beyond its physical importance in both fundamental and climate research, atmospheric icing is considered as a severe operational condition in many engineering applications like aviation, electrical power transmission and wind-energy production. To reproduce such icing conditions in a laboratory environment, icing wind tunnels are frequently used. In this paper, a comprehensive overview on the design, construction and commissioning of the Braunschweig Icing Wind Tunnel is given. The tunnel features a test section of 0.5 m  ×  0.5 m with peak velocities of up to 40 m s−1. The static air temperature ranges from −25 to +30 °C. Supercooled droplet icing with liquid water contents up to 3 g m−3 c…

Optimal use of the Prede POM sky radiometer for aerosol, water vapor, and ozone retrievals

2021

The Prede POM sky radiometer is a filter radiometer deployed worldwide in the SKYNET international network. A new method, called Skyrad pack MRI version 2 (MRI v2), is presented here to retrieve aerosol properties (size distribution, real and imaginary parts of the refractive index, single-scattering albedo, asymmetry factor, lidar ratio, and linear depolarization ratio), water vapor, and ozone column concentrations from the sky radiometer measurements. MRI v2 overcomes two limitations of previous methods (Skyrad pack versions 4.2 and 5, MRI version 1). One is the use of all the wavelengths of 315, 340, 380, 400, 500, 675, 870, 940, 1020, 1627, and 2200 nm if available from the sky radiomet…

The airborne mass spectrometer AIMS – Part 2: Measurements of trace gases with stratospheric or tropospheric origin in the UTLS

2016

Understanding the role of climate-sensitive trace gas variabilities in the upper troposphere and lower stratosphere region (UTLS) and their impact on its radiative budget requires accurate measurements. The composition of the UTLS is governed by transport and chemistry of stratospheric and tropospheric constituents, such as chlorine, nitrogen oxide and sulfur compounds. The Atmospheric chemical Ionization Mass Spectrometer AIMS has been developed to accurately measure a set of these constituents on aircraft by means of chemical ionization. Here we present a setup using SF5− reagent ions for the simultaneous measurement of trace gas concentrations of HCl, HNO3 and SO2 in the  pptv to ppmv (1…

An overview of and issues with sky radiometer technology and SKYNET

2020

This paper is an overview of the progress in sky radiometer technology and the development of the network called SKYNET. It is found that the technology has produced useful on-site calibration methods, retrieval algorithms, and data analyses from sky radiometer observations of aerosol, cloud, water vapor, and ozone. A formula was proposed for estimating the accuracy of the sky radiometer calibration constant F0 using the improved Langley (IL) method, which was found to be a good approximation to observed monthly mean uncertainty in F0, around 0.5 % to 2.4 % at the Tokyo and Rome sites and smaller values of around 0.3 % to 0.5 % at the mountain sites at Mt. Sarasw…

Nano-hygroscopicity tandem differential mobility analyzer (nano-HTDMA) for investigating hygroscopic properties of sub-10 nm aerosol nanoparticles

2020

Interactions between water and nanoparticles are relevant for atmospheric multiphase processes, physical chemistry, and materials science. Current knowledge of the hygroscopic and related physicochemical properties of nanoparticles, however, is restricted by the limitations of the available measurement techniques. Here, we present the design and performance of a nano-hygroscopicity tandem differential mobility analyzer (nano-HTDMA) apparatus that enables high accuracy and precision in hygroscopic growth measurements of aerosol nanoparticles with diameters less than 10 nm. Detailed methods of calibration and validation are provided. Besides maintaining accurate and stable sheath and a…

Determination and analysis of in situ spectral aerosol optical properties by a multi-instrumental approach

2014

Continuous in situ measurements of aerosol optical properties were conducted from 29 June to 29 July 2012 in Granada (Spain) with a seven-wavelength Aethalometer, a Multi-Angle Absorption Photometer, and a three-wavelength integrating nephelometer. The aim of this work is to describe a methodology to obtain the absorption coefficients (babs) for the different Aethalometer wavelengths. In this way, data have been compensated using algorithms which best estimate the compensation factors needed. Two empirical factors are used to infer the absorption coefficients from the Aethalometer measurements: C – the parameter describing the enhancement of absorption by particles in the filter matrix due …