680 research outputs found
Nasal cavity lobular capillary hemangioma due to insect sting
SummaryIntroductionLobular capillary hemangioma is a frequent benign vascular inflammatory lesion of the skin tissue. It rarely reaches the mucous membrane, and the nasal fossa involvement is exceptional.Case reportA 68-year-old woman presented with an ulcerous hemorrhagic mass blocking the left nasal fossa, which had appeared a few weeks after a wasp sting in the nose. The insect was evacuated only three weeks after the sting. The clinical and radiological data suggested malignancy. Biopsy under local anesthesia proved non-contributory and was complicated by 1 week's hospitalization for severe nosebleed. Surgical excision under video-endoscopy confirmed diagnosis. At 31 months’ follow-up, the patient was free of recurrence.Discussion/conclusionThe pathogeny of lobular capillary hemangioma is uncertain. No previous cases affecting the mucous membrane after insect sting have been reported. Except in the typical contexts of long-term packing or pregnancy, diagnosis can be difficult and misleading. It can mimic a malignant pathology. Its rich vascularization requires caution during biopsy, and the risk of recurrence requires excision to be complete
Use of reciproc instruments with different motions: cyclic fatigue testing with simulation of the body temperature
Aim: To assess the influence of different motions on the cyclic fatigue resistance of Reciproc instruments simulating the temperature of the clinical conditions. Methods: The sample size was determined using statistical software set with the following parameters: \u3b1=0.05, \u3b2=0.20, \u3b4=30.0, \u3c3=28.0. The experiment required 54 Reciproc files. Brand new R25 files were randomly allocated to three groups defined by the tested motion: continuous rotation at 300 rpm (n=18), \u201cRECIPROC\u201d mode (n=18), and \u201cWAVEONE\u201d mode (n=18). The same endodontic motor was used for all groups (X-Smart IQ). All files were rotated/reciprocated until fracture inside a custom-designed artificial canal with 60\ub0 angle and 5-mm radius of curvature milled in a stainless-steel block. The testing device was electrically heated to keep its internal temperature at 35\ub11\ub0C, which was constantly monitored with a thermometer. After file separation, the time to failure was registered with a digital chronometer and the length of the fractured fragment measured with a digital calliper. The fracture surface of each file was observed at the scanning electron microscope to perform a qualitative fractographic analysis. The
collected data (time to fracture and fracture length) were tested for the normality of the distribution and the equality of variances with a Shapiro-Wilk and a Levene test, respectively. The dependent variables were compared amongst groups by means of a multivariate analysis of variance and Tuckey post-hoc test (p=0.05). Results: The continuous rotation group exhibited the shortest lifespan among the considered groups (85.4\ub19.5 s to failure). Both reciprocating motions were associated with a significant improvement of fatigue resistance (p<0.001). The \u201cRECIPROC\u201d mode allowed for longer time to failure than the \u201cWAVEONE\u201d mode, with 141.6\ub119.4 s and 117.2\ub111.2 s to failure, respectively. The absence of differences among the considered groups in terms of fracture length confirmed the correct positioning of the files inside the artificial canal. The scanning electron microscopic analysis showed signs of file separation ascribable to cyclic fatigue. Conclusion: The present study preliminary demonstrated
that the native \u201cRECIPROC\u201d motion use of R25 Reciproc files should be preferred over other types of motions to prevent file separation in the clinical setting
Luz e temperatura na germinação de sementes de pimenta longa (Piper hispidinervum) e pimenta-de-macaco (Piper aduncum).
As espécies Piper hispidinervum e Piper aduncum destacam-se como produtoras de óleos essenciais ricos em compostos de interesse às indústrias de perfumaria e produtos fitossanitários, como o safrol e dilapiol. Essas espécies encontram-se em processo de domesticação e estudos sobre o processo germinativo de suas sementes são escassos. Assim, objetivou-se com o presente trabalho avaliar a viabilidade de sementes de P. hispidinervum e P. aduncum, buscando determinar um protocolo eficiente para a realização do teste de germinação para cada espécie estudada. O trabalho foi conduzido no período de julho a agosto de 2008, sendo as sementes submetidas a diferentes combinações de temperatura e de luz: 20 °C e 25 °C sob luz branca e difusa; e 20-30 °C alternando escuro (16 h) e claro (8 h), totalizando cinco tratamentos. O tratamento utilizando a temperatura de 25 °C com incidência de luz branca foi o que produziu melhores resultados, com maiores valores de porcentagem e velocidade de germinação sendo, portanto, indicado para avaliação da qualidade fisiológica das sementes de pimenta longa e pimenta-de-macaco
Approach combining the Rietveld method and pairs distribution function analysis to study crystalline materials under high-pressure and/or temperature: Application to rhombohedral Bi2Te3 phase
An approach combining the Rietveld method and pairs distribution function
analysis to study crystalline materials under high pressure or temperature was
early proposed by us, and in this study, it was applied to investigate de
effect of high pressure on the rhombohedral Bi2Te3 phase. The refined
structural parameters obtained from the Rietveld refinement of the XRD patterns
measured for pressures up to 9.1 GPa were used as input data to simulate the
partial and total structure factors SBiBi, SBiTe, STeTe, and SBi2Te3. Fourier
transformation of the Sij factors permitted to obtain the partial and total
pairs distribution functions GBiBi, GBiTe, GTeTe, and GBi2Te3. The first
coordination shells of these Gij functions are formed by subshells and, with
increasing pressure in the 1.1 to 6.3 GPa range, occur a partial separation of
subshells. Also, the increase of pressure in this range promotes a drastic
reduction in the values of the intralayer angles TeBiTe, and consequently, in
the intralayer distance TeTe. A drastic reduction in the interlayers distance
Te-Te was also observed. Several studies are reported in the literature,
including one carried out by us, show the presence of an ETT in this pressure
range. The obtained results suggest that the ETT is related with the decrease
of the intralayer angles TeBiTe, and intra- and interlayer distance TeTe.
Experimental results describing the pressure dependence the thermoelectric
power, electrical resistivity, and power fator for rhombohedral Bi2Te3 are
reported, and an enhancement of the power factor in the 1.1 to 6.3 GPa range is
observed. The results obtained in this study give evidence that this
enhancement in the power factor is related with the decrease of the intralayer
angles TeBiTe, and with the decrease of intralayer- and interlayers homopolar
TeTe bonds
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