Presencia de Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola y Aggregatibacter actinomycetemcomitans en el biofilm subgingival de pacientes diabéticos tipo 2: Estudio transversal

ResumenAntecedentesLa investigación de la microflora subgingival en pacientes diabéticos tipo 2 con periodontitis ha presentado resultados contradictorios.ObjetivoDeterminar la presencia de Porphyromonas gingivalis, Tannerella forshytia, Treponema denticola y Aggregatibacter actinomycetemcomitans, en el biofilm subgingival de pacientes diabéticos tipo 2 y relacionarlo con el grado de control metabólico.MétodoEstudio descriptivo transversal, en el cual se analizaron 23 pacientes diabéticos derivados consecutivamente del Policlínico de Especialidades de la Universidad de los Andes. Previo consentimiento informado, se realizó un examen clínico periodontal que incluyó mediciones de profundidad al sondaje, nivel de inserción clínica y sangrado gingival. Fueron clasificados según severidad de periodontitis y control metabólico de la diabetes determinado por un promedio de 3 exámenes de hemoglobina glicosilada. La detección microbiológica se realizó mediante la técnica de reacción en cadena de la polimerasa.ResultadosEn el grupo de pacientes estudiados, Treponema denticola y Tannerella forsythia fueron las bacterias más prevalentes (65.2%), seguida por Porphyromonas gingivalis (17.3%) y Aggregatibacter actinomycetemcomitans (13%). Los pacientes con peor control glicémico tuvieron una mayor presencia de Treponema denticola, Tannerella forsythia, Porphyromonas gingivalis y Agreggatibacter actinomycetemcomitans y un aumento en el índice de sangrado al sondaje.ConclusionesEn el grupo de pacientes diabéticos estudiado, las bacterias más prevalentes fueron Treponema denticola y Tannerella forsythia. Los pacientes diabéticos tipo 2 con moderado y mal control glicémico presentaron mayor presencia de los microorganismos estudiados, comparado con los grupos con mejores niveles de control glicémico.AbstractBackgroundThe investigation of subgingival microflora in type 2 diabetic patients with periodontitis presented conflicting results.AimTo determine the presence of Porphyromonas gingivalis, Tannerella forshytia, Treponema denticola and Aggregatibacter actinomycetemcomitans in subgingival biofilm of patients with diabetes type 2 and to relate it to the degree of metabolic control.MethodA descriptive study, which analyzed 23 diabetic patients consecutively referred from the Internal Medicine Unit of Medicine Faculty at Universidad de los Andes was conducted. After obtaining an informed consent from the patients a clinical examination that included measurements of periodontal pocket depth, clinical attachment level and gingival bleeding was performed. The patients were classified according to the severity of periodontitis and metabolic control of diabetes as determined by an average of 3 of glycosylated haemoglobin tests. Microbial technique was performed by chain reaction of polymerase.ResultsIn the group of patients examined the most prevalent bacteria were, Treponema denticola and Tannerella forsythia (65.2%), followed by Porphyromonas gingivalis (17.3%) and Aggregatibacter actinomycetemcomitans (13%). Patients with poor glycemic control had a greater presence of Treponema denticola, Tannerella forsythia, Porphyromonas gingivalis and Agreggatibacter actinomycetemcomitans and an increase in the rate of bleeding on probing.ConclusionsIn the group of diabetic patients studied, the most prevalent bacteria were Treponema denticola and Tannerella forsythia. Type 2 diabetic patients with moderate and poor glycemic control had a higher presence of these microorganisms, compared to groups with higher levels of glycemic control

Carbon aerogel supported platinum catalysts for selective hydrogenation of cinnamaldehyde

This paper describes the preparation and characterization of 1% wt. Pt catalysts supported in carbon aerogels for the application in the liquid-phase selective hydrogenation of cinnamaldehyde. Carbon aerogel supports with different textures were activated with hydrogen peroxide and ammonium peroxydisulfate leading to large amounts of surface groups but keeping unchanged their textural properties. After introducing Pt, the surface chemistry and morphology of the catalysts was characterized by analytical techniques like SEM, TPD, N2 adsorption isotherms, mercury porosimetry and H2 chemisorption. Catalysts prepared with activated aerogels exhibited good selectivity towards the desired product, cinnamyl alcohol. A high temperature post-treatment of the catalysts failed to enhance their selectivity, mainly leading to hydrocinnamaldehyde production

Photophysical properties of thin films and solid phase of switchable supermolecular anthracene-based rotaxanes

Polycrystalline powders and thin films of a novel rotaxane, methyl-exopyridine-anthracene rotaxane (EPAR-Me), and of the related thread and stoppers 10-[3,5-di (ter butyl)phenoxy]decyl-2-({2-[(9-anthrylcarbonyl) amino] acetyl}amino) acetate (ANTPEP), have been characterised by photoluminescence, absorption and photoluminescence excitation spectroscopy. A rather unusual, i.e. unstructured and largely red-shifted, photoluminescence spectral behaviour of the rotaxane has been found. Preliminary time resolved measurements indicate a fast energy transfer from the anthracene unit to different species the nature of which is still not assigned.

UV and EUV Instruments

We describe telescopes and instruments that were developed and used for astronomical research in the ultraviolet (UV) and extreme ultraviolet (EUV) regions of the electromagnetic spectrum. The wavelength ranges covered by these bands are not uniquely defined. We use the following convention here: The EUV and UV span the regions ~100-912 and 912-3000 Angstroem respectively. The limitation between both ranges is a natural choice, because the hydrogen Lyman absorption edge is located at 912 Angstroem. At smaller wavelengths, astronomical sources are strongly absorbed by the interstellar medium. It also marks a technical limit, because telescopes and instruments are of different design. In the EUV range, the technology is strongly related to that utilized in X-ray astronomy, while in the UV range the instruments in many cases have their roots in optical astronomy. We will, therefore, describe the UV and EUV instruments in appropriate conciseness and refer to the respective chapters of this volume for more technical details.Comment: To appear in: Landolt-Boernstein, New Series VI/4A, Astronomy, Astrophysics, and Cosmology; Instruments and Methods, ed. J.E. Truemper, Springer-Verlag, Berlin, 201

Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory

Atmospheric parameters, such as pressure (P), temperature (T) and density, affect the development of extensive air showers initiated by energetic cosmic rays. We have studied the impact of atmospheric variations on extensive air showers by means of the surface detector of the Pierre Auger Observatory. The rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find that the observed behaviour is explained by a model including the effects associated with the variations of pressure and density. The former affects the longitudinal development of air showers while the latter influences the Moliere radius and hence the lateral distribution of the shower particles. The model is validated with full simulations of extensive air showers using atmospheric profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle Physic

The exposure of the hybrid detector of the Pierre Auger Observatory

The Pierre Auger Observatory is a detector for ultra-high energy cosmic rays. It consists of a surface array to measure secondary particles at ground level and a fluorescence detector to measure the development of air showers in the atmosphere above the array. The "hybrid" detection mode combines the information from the two subsystems. We describe the determination of the hybrid exposure for events observed by the fluorescence telescopes in coincidence with at least one water-Cherenkov detector of the surface array. A detailed knowledge of the time dependence of the detection operations is crucial for an accurate evaluation of the exposure. We discuss the relevance of monitoring data collected during operations, such as the status of the fluorescence detector, background light and atmospheric conditions, that are used in both simulation and reconstruction.Comment: Paper accepted by Astroparticle Physic

The Fluorescence Detector of the Pierre Auger Observatory

The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays. It combines a surface array to measure secondary particles at ground level together with a fluorescence detector to measure the development of air showers in the atmosphere above the array. The fluorescence detector comprises 24 large telescopes specialized for measuring the nitrogen fluorescence caused by charged particles of cosmic ray air showers. In this paper we describe the components of the fluorescence detector including its optical system, the design of the camera, the electronics, and the systems for relative and absolute calibration. We also discuss the operation and the monitoring of the detector. Finally, we evaluate the detector performance and precision of shower reconstructions.Comment: 53 pages. Submitted to Nuclear Instruments and Methods in Physics Research Section

Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{$6\times 10^{19}$eV}. The anisotropy was measured by the fraction of arrival directions that are less than $3.1^\circ$ from the position of an active galactic nucleus within 75 Mpc (using the V\'eron-Cetty and V\'eron $12^{\rm th}$ catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is $(38^{+7}_{-6})$, compared with $21$ expected for isotropic cosmic rays. This is down from the early estimate of $(69^{+11}_{-13})$. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201

Search for First Harmonic Modulation in the Right Ascension Distribution of Cosmic Rays Detected at the Pierre Auger Observatory

We present the results of searches for dipolar-type anisotropies in different energy ranges above $2.5\times 10^{17}$ eV with the surface detector array of the Pierre Auger Observatory, reporting on both the phase and the amplitude measurements of the first harmonic modulation in the right-ascension distribution. Upper limits on the amplitudes are obtained, which provide the most stringent bounds at present, being below 2% at 99% $C.L.$ for EeV energies. We also compare our results to those of previous experiments as well as with some theoretical expectations.Comment: 28 pages, 11 figure