Search results for "Period"
showing 10 items of 4072 documents
The effects of antimicrobial sprays and mouthrinses on supragingival plaque regrowth: a comparative study.
2006
BACKGROUND: Due to the side effects of chlorhexidine digluconate (CHX) mouthrinsing, a spray has been proposed as an alternative method of CHX delivery to the oral cavity. The aim of this study was to investigate the plaque inhibitory effects of CHX, cetylpyridinium chloride (CPC), and triclosan (TRN) delivered by sprays and mouthrinses. METHODS: The study was an observer-masked, randomized cross-over design balanced for carryover effects, involving 15 healthy volunteers in a 4-day plaque regrowth model. Products being tested (0.2% CHX, 0.12% CHX, 0.05% CPC, and 0.03% TRN) were used both as sprays and mouthrinses. A saline solution served as a negative control. On day 1, subjects received p…
Evidence of a non-conservative mass transfer in the ultra-compact X-ray source XB 1916-053
2020
The dipping source XB 1916-053 is a compact binary system with an orbital period of 50 min harboring a neutron star. Using ten new {\it Chandra} observations and one {\it Swift/XRT} observation, we are able to extend the baseline of the orbital ephemeris; this allows us to exclude some models that explain the dip arrival times. The Chandra observations provide a good plasma diagnostic of the ionized absorber and allow us to determine whether it is placed at the outer rim of the accretion disk or closer to the compact object. From the available observations we are able to obtain three new dip arrival times extending the baseline of the orbital ephemeris from 37 to 40 years. From the analysis…
In vivo investigation on stem cells isolated from dental pulp and gingival tissues from periodontally compromised teeth
2015
Tooth replacement rates in early chondrichthyans: a qualitative approach
2009
The continuous replacement of teeth throughout their lifetime is a common characteristic of most chondrichthyans. This process was already present in the earliest representatives of the group. It has been well established that different species of extant sharks show rapid tooth replacement rates; however, some authors have suggested that in early chondrichthyans this rate might have been much slower. Here we present a qualitative approach to analyse tooth replacement rates in the Early Devonian shark Leonodus carlsi, the earliest tooth-bearing shark known to date. For this, we have examined 1,103 isolated teeth from Celtiberia, Spain. Our study provides strong evidences of an extremely slow…
Valoración clínica del estado dental y periodontal en un grupo de pacientes oncológicos, previo inicio de la quimioterapia
2006
Objetivos: Valorar el estado bucodental en 88 pacientes con cánceres corporales, previo al inicio de su tratamiento quimioterápico. Diseño del estudio: Estudiamos 88 pacientes con cánceres de diferentes localizaciones corporales y los comparamos con un grupo control. Analizamos la placa dental (mediante el índice de Silness y Löe), el estado dental (mediante el índice CAO.D) y el estado periodontal (índice CPI modificado). Resultados: En el grupo de pacientes oncológicos, la media del índice de placa de Silnness y Löe fue de 1,28±0,11. Los pacientes presentaban múltiples ausencias dentarias, siendo la media de dientes ausentes por caries de 7,55±0,80. También se observó que la media de cari…
Enzimas salivales y enfermedad periodontal
2006
Objetivos: Las enfermedades que producen daño tisular producen la liberación de diferentes enzimas relacionadas con la muerte y destrucción celular, como son la aspartato y alanino aminotransferasa (AST, ALT), lactato dehidrogenasa (LDH), creatinin kinasa (CK), alcalina y ácida (ALP, ACP) y gamma glutamil transferasa (GGT). Al tratarse la enfermedad periodontal (EP) de un proceso inflamatorio con afectación de la encía y periodonto, parece lógico pensar que la actividad enzimática debe reflejar los cambios metabólicos secundarios a esta reacción inflamatoria. Diseño del estudio: En este artículo examinamos la actividad de CK, LDH, AST, ALT, GGT, ALP y ACP en la saliva de pacientes con EP, a…
La riforma ortografica di Rust e la Neuregelung 1996: cesura o continuità?
2007
Incipit. Tra storia e futuro
2019
La storiografia intellettuale deve essere rivista alla luce di nuove prospettive ermeneutiche che rivedano le periodizzazioni consolidate, basate su una visione eurocentrica.
Les traces de pas d'amphibiens, de dinosaures et autres reptiles du Mésozoïque français: inventaire et interprétations.
2007
Since the 19th century, thousands of footprints were observed in the geological series of the French Mesozoic. All are located in the Triassic and Jurassic. After a promising beginning, in France, it is only a few papers which will be published in the first half 20th century, unlike the USA and of others countries of Western Europe. One ought to wait about 1950 for a revival and now they are nearly 200 papers which were devoted to the ichnofossils. The literature abundance and the renewed interest of the naturalists for the palichnologic studies decided to us to write a synthesis work. This one begins with a stratigraphic inventory in which, localisation, age and paleontological contents of…
Modelling the evolution of periodicity in the periodical cicadas
2018
Background: Periodical cicadas (Magicicada spp.) have a life cycle that ends with the entire underground nymph population exhibiting a synchronized mass emergence to mate above ground. Previous studies have hypothesized that the periodical cicadas evolved from non-periodical cicadas by switching from a life-cycle length determined by body size to one determined by age. Questions: When can a mutation coding for fixed life-cycle length invade a resident population in which life-cycle length is variable? What determines the length of the fixed cycle? Methods: Numerical analysis of a mathematical model and simulations of an individual-based model. Results: If there is a sufficiently strong pred…