849 research outputs found
Subperiostial orbital abscess and apex syndrome as a complication after a mandibular molar extraction
Indexación: Web of Science; ScieloIntroducción: La diseminación de las infecciones que se extienden de dientes mandibulares y estructuras adyacentes hacia la órbita y tejido periorbitario son infrecuentes, pero graves ya que tienen el potencial de causar la pérdida de la visión.
Objetivos: El propósito de este artículo es publicar un caso clínico muy interesante por lo infrecuente, y explicar a juicio de los autores las vías de diseminación de la infección, a su vez alertar a los diferentes especialistas involucrados sobre las severas consecuencias que pueden resultar tras la extracción de piezas dentales, como es la pérdida definitiva de la visión.
Reporte del caso: Se trata de un paciente masculino de 43 años, sin antecedentes mórbidos relevantes, que fue enviado al Servicio Médico Legal para examen clínico forense con pérdida total de la visión del ojo derecho por atrofia óptica como complicación de un síndrome del vértice orbitario, luego de la exodoncia del tercer molar mandibular derecho.
Conclusiones: Es fundamental el tratamiento oportuno y agresivo para detener la diseminación de una infección desde las estructuras adyacentes hacia la órbita. La comunicación efectiva interdisciplinaria entre los profesionales involucrados evita complicaciones de tipo médico-legales y secuelas definitivas al paciente.Introduction: Infection dissemination from mandibular teeth to the orbit and adjacent structures is infrequent, but nevertheless serious, as they may cause severe problems, including vision loss.
Aim: The purpose of this study is to present a rare and interesting case of such a dissemination, to discuss the possible routes of infection propagation, and to alert the different specialists involved on the possible complications after dental extractions, such as visual loss.
Report of the case: The case of a 43-year-old previously healthy male is presented. The patient was sent to the Medical Legal Service for clinical forensic examination after total vision loss of the right eye, caused by optic atrophy as a complication of orbital apex syndrome, after the extraction of the third right mandibular molar.
Conclusions: Opportune and aggressive treatment is crucial to stop infection spread from adjacent structures to the orbit. Effective communication among the professionals involved avoids medical - legal complications and precludes permanent sequels to the patient.http://ref.scielo.org/yz5gt
TDDFT-Based Study on the Proton-DNA Collision
The interaction of heavy charged particles with DNA is of interest for hadrontherapy and the aerospace industry. Here, a time-dependent density functional theory study on the interaction of a 4 keV proton with an isolated DNA base pair (bp) was carried out. Ehrenfest dynamics was used to study the evolution of the system up to about 193 fs. It was observed that the dissociation of the target occurs between 80 and 100 fs. The effect of bp linking to the DNA double helix was emulated by fixing the four O3′ atoms responsible for the attachment. The bp tends to dissociate into its main components, namely, the phosphate groups, sugars, and nitrogenous bases. A central impact with an energy transfer of 17.9 eV only produces a base damage while keeping the backbone intact. An impact on a phosphate group with an energy transfer of about 60 eV leads to a backbone break at that site together with a base damage, and the opposite backbone site integrity is kept. As the whole system is perturbed during this collision, no atom remains passive. These results suggest that base damage accompanies all backbone breaks as the hydrogen bonds that keep bases together are much weaker that those between the other components of the DNA
A fully automated flow injection atomic absorption system for the determination of copper traces in waters with on-line pre-concentration in an ion-exchange column
The paper describes the development of an automatic on-line column
pre-concentration technique using a time based-flow injection atomic absorption spectrometry system. A manifold incorporating a micro-column containing 25 mg of Dowex 50W-X8 was used with a time-based injector for the pre-concentration and determination of
copper in natural and drinking waters. The system features depend on the alternate positions of a solenoid valve. The 3σ detection limits, enrichment factors, sampling frequency, relative standard deviations and linear calibration graphs were, respectively, in the range 0.6-1.5 μg/l, 25-60, 15-30 measurements/h, 1.0-3.1% and 1-65 μg/ml for pre-concentration times of 1 min. The procedure was successfully applied to a range of water samples and the accuracy was assessed through recovery experiments, the analysis of certified reference water samples and by independent analysis by
atomic absorption spectrometry with electrothermal atomization
Abordagem computacional para a identificação de elementos cis-regulatórios no genoma da soja.
bitstream/item/71812/1/ID-30970.pd
Abordagem computacional para a identificação de elementos cis-regulatóriso no genoma da soja.
bitstream/item/71511/1/ID-31371.pd
Methane and Nitrogen Abundances On Pluto and Eris
We present spectra of Eris from the MMT 6.5 meter telescope and Red Channel
Spectrograph (5700-9800 angstroms; 5 angstroms per pix) on Mt. Hopkins, AZ, and
of Pluto from the Steward Observatory 2.3 meter telescope and Boller and
Chivens spectrograph (7100-9400 angstroms; 2 angstroms per pix) on Kitt Peak,
AZ. In addition, we present laboratory transmission spectra of methane-nitrogen
and methane-argon ice mixtures. By anchoring our analysis in methane and
nitrogen solubilities in one another as expressed in the phase diagram of
Prokhvatilov and Yantsevich (1983), and comparing methane bands in our Eris and
Pluto spectra and methane bands in our laboratory spectra of methane and
nitrogen ice mixtures, we find Eris' bulk methane and nitrogen abundances are
about 10% and about 90%, and Pluto's bulk methane and nitrogen abundances are
about 3% and about 97%. Such abundances for Pluto are consistent with values
reported in the literature. It appears that the bulk volatile composition of
Eris is similar to the bulk volatile composition of Pluto. Both objects appear
to be dominated by nitrogen ice. Our analysis also suggests, unlike previous
work reported in the literature, that the methane and nitrogen stoichiometry is
constant with depth into the surface of Eris. Finally, we point out that our
Eris spectrum is also consistent with a laboratory ice mixture consisting of
40% methane and 60% argon. Although we cannot rule out an argon rich surface,
it seems more likely that nitrogen is the dominant species on Eris because the
nitrogen ice 2.15 micron band is seen in spectra of Pluto and Triton.Comment: The manuscript has 44 pages, 15 figures, and four tables. It will
appear in the Astrophysical Journa
An apparatus for in-situ direct shear tests on snow
The article presents a prototype of a new device for measuring the shear strength of snow specimens in situ. The resistance to sliding of a snow slab on a mountain slope is a key parameter in snow mechanics. The proposed apparatus acts as a sampler, to obtain a nearly undisturbed specimen, and as a shear box, similar to those used in the laboratory, with complete control of the test procedure. The main components of the device are a pneumatic system, for the application of normal and shear forces to the specimen, a real-time controller for commanding and recording of the data, and a computer. The apparatus can be carried to the place of the experiments and operated by a team of two researchers. Calibration and preliminary tests are also described in the article
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