Search results for "sers"
showing 10 items of 478 documents
Protein dynamics observed by tunable mid-IR quantum cascade lasers across the time range from 10 ns to 1 s
2017
We have developed a spectrometer based on tunable quantum cascade lasers (QCLs) for recording time-resolved absorption spectra of proteins in the mid-infrared range. We illustrate its performance by recording time-resolved difference spectra of bacteriorhodopsin in the carboxylic range (1800–1700 cm− 1) and on the CO rebinding reaction of myoglobin (1960–1840 cm− 1), at a spectral resolution of 1 cm− 1. The spectrometric setup covers the time range from 4 ns to nearly a second with a response time of 10–15 ns. Absorption changes as low as 1 × 10− 4 are detected in single-shot experiments at t > 1 μs, and of 5 × 10− 6 in kinetics obtained after averaging 100 shots. While previous time-res…
Study of the dynamics of biomolecules by high speed atomic force microscopy and surface enhanced Raman spectroscopy
2015
This thesis focuses on the coupling of High–Speed Atomic Force Microscopy (HS-AFM) and Surface Enhanced Raman Spectroscopy (SERS) for biomolecule analysis. We have designed a fabrication protocol to manufacture “SERS-active” substrates. The efficacy of gold, silver and gold-silver bimetallic crystalline nanoparticle substrates were evaluated. We have investigated the impact of optical and morphological features of the substrates on Raman signal intensity by analyzing well-known samples such as bipyridine ethylene and methylene blue molecules. We took an interest in three distinct biological problematics with HS-AFM and SERS analyses. First, we have detected the chemical signature of cytochr…
Er:YAG laser in defocused mode for scaling of periodontally involved root surfaces: An in vitro pilot study
2005
Item does not contain fulltext BACKGROUND: The Er:YAG laser may be used on periodontally involved teeth in combination with conventional periodontal therapy in order to improve the efficacy of root instrumentation. The aim of this study was to compare the effect of hand instrumentation on root surfaces of periodontally involved teeth with Er:YAG laser application. METHODS: Thirty freshly extracted, non-carious, single-rooted, periodontally diseased human teeth from adult humans with advanced periodontal disease were used in this study. The teeth were divided into three groups of 10 specimens each. Group A was treated with scaling and root planing (SRP) with curets only (control). In group B…
A tractor mounted scanning LIDAR for the non-destructive measurement of vegetative volume and surface area of tree-row plantations: A comparison with…
2009
The use of a low-cost tractor-mounted scanning Light Detection and Ranging (LIDAR) system for capable of making non-destructive recordings of tree-row structure in orchards and vineyards is described. Field tests consisted of several LIDAR measurements on both sides of the crop row, before and after defoliation of selected trees. Summary parameters describing the tree-row volume and the total crop surface area viewed by the LIDAR (expressed as a ratio with ground surface area) were derived using a suitable numerical algorithm. The results for apple and pear orchards and a wine producing vineyard were shown to be in reasonable agreement with the results derived from a destructive leaf sampli…
Real-time measurements of Volcanic Gases based by Infrared Spectroscopy
2014
Near-infrared Tunable Diode Lasers have recently found increased usage in atmospheric chemistry and air monitoring research, but applications in Volcanology are still limited to a few examples. The Tunable Diode Laser Spectroscopy technique (TDLS) relies on measuring the absorbance at specific wavelengths due to the absorption of IR radiation by a target gas. Here, we report on the application of the GasFinder 2.0, a commercial infrared laser-receiver unit operating in the 1.3-1.7 m wavelength range, to measuring CO2 concentrations and fluxes in volcanic gas emissions. Our field tests were conducted at Campi Flegrei volcano (near Pozzuoli, Southern Italy), where the GasFinder was used (duri…
Stark ionization of atoms and molecules within density functional resonance theory
2013
We show that the energetics and lifetimes of resonances of finite systems under an external electric field can be captured by Kohn–Sham density functional theory (DFT) within the formalism of uniform complex scaling. Properties of resonances are calculated self-consistently in terms of complex densities, potentials, and wave functions using adapted versions of the known algorithms from DFT. We illustrate this new formalism by calculating ionization rates using the complex-scaled local density approximation and exact exchange. We consider a variety of atoms (H, He, Li, and Be) as well as the H2 molecule. Extensions are briefly discussed.
OVERTURE Love Love is a Pink Cake or Queering Chopin in Times of Homophobia
2021
An introduction to the three essays included in this section. The article highlights the right to know whether Chopin was gay and contextualizes this inquiry in a very long and pervasive historiographical tradition, essentially twohundred years long, dedicated to examine Chopin sexual orientation, on the one hand, and on the other the more recent tradition of queering western classical music composers. The main point is not to demonstrate categorically that Chopin was ?gay? (a relative, modern identity marker in any case) but rather to highlight the discourses that have presented him as unequivocally heterosexual.
Evolución de la resistencia transmitida y adquirida a fármacos antirretrovirales en pacientes infectados con VIH-1
2018
Introducción: La adquisición y transmisión de resistencia amenaza el éxito del tratamiento antirretroviral. En este estudio evaluamos el comportamiento epidemiológico de las mutaciones de resistencia (MR) a fármacos antirretrovirales del VIH-1 según factores de riesgo y clínicos específicos. Metodología: Este es un estudio retrospectivo observacional de series transversales acumuladas, realizado en la Unidad de Enfermedades Infecciosas de un hospital universitario en España (CHGUV) entre los años 2003 y 2014. Nuestro objetivo fue estimar la evolución de la frecuencia anual de MR a fármacos antirretrovirales en el genoma de la proteasa y transcriptasa inversa del VIH-1 durante el periodo de …
Pique-niquer in Paris
2015
Una antica tradizione rinnova il rapporto tra Parigi e i suoi abitanti: l’uso sociale e pubblico di prati, giardini, scalinate, sponde dei canali e lungofiume per consumare, con estrema nonchalance, il rito del picnic. Pique-niquer è un verbo francese che abbina piquer (prendere, rubacchiare, spilluzzicare) con nique (piccola cosa di poco valore). La città gli tributa generosamente i suoi spazi pubblici dove si riversano coppie, gruppi, famiglie, attrezzati di tutto punto per godere di un pranzo o soltanto di uno spuntino all’aperto, immersi tra i panorami urbani più suggestivi. An old tradition renews the relationship existing between Paris and her inhabitants: the social and public use…
WhoSNext: Recommending Twitter Users to Follow Using a Spreading Activation Network Based Approach
2020
The huge number of modern social network users has made the web a fertile ground for the growth and development of a plethora of recommender systems. To date, recommending a new user profile X to a given user U that could be interested in creating a relationship with X has been tackled using techniques based on content analysis, existing friendship relationships and other pieces of information coming from different social networks or websites. In this paper we propose a recommending architecture - called WhoSNext (WSN) - tested on Twitter and which aim is promoting the creation of new relationships among users. As recent researches show, this is an interesting recommendation problem: for a …