20 research outputs found
Primary mucosal melanoma presenting with a unilateral nasal obstruction of the left inferior turbinate
We report the case of a primitive nasal melanoma in an 82-year-old patient, showing how this rare malignancy, with non-specific signs and symptoms, can represent a challenging diagnosis for the physician. A 82-year-old Caucasian patient presented for unilateral nasal obstruction and occasional epistaxis. Computerized tomography (CT) and magnetic resonance imaging (MRI) of the facial massif revealed turbinate hypertrophy and a polypoid phlogistic tissue isointense in T1 with an intermediate signal in T2 and Short-TI Inversion Recovery (STIR)-T2, occupying the middle meatus and the anterior upper and lower left meatus with partial obliteration of the ostium and the infundibulum of the maxillary sinus. The Positron emission tomography (PET) exam was negative for metastases. Conservatory surgery in the left anterior video rhinoscopy was performed, allowing a radical 4-cm tumor excision. Histology reported epithelioid cell melanoma, PanK−, CD45−, and PanMelanoma+. Adjuvant radiotherapy was suggested, even considering a complete resection as the result of surgery. No local or systemic relapse was noticed at the 2-month follow-up visit. Although mucosal melanoma is a rare and aggressive malignancy characterized by a poor prognosis, early diagnosis allows a more conservative approach, with little surgical difficulty and no aesthetic effect. Our case raises awareness of the importance of early intervention even in those cases where the clinic symptoms and diagnostic images show uncertain severity
EFEITO DO USO DE INOCULANTES SOBRE O pH E A COMPOSIÇÃO BROMATOLÓGICA DA SILAGEM DE SORGO (Sorghum bicolor L. Moench)
The objective of this work was to study the effect of three doses of commercial bacterial inoculant Sil-All (Alltech®), on the pH and the quality of the silage of sorgo, variety AG 2005. Sixteen experimental silos had been used, with capacity for 20kg of silage. The tested treatments had been T1 without the inoculante addition, T2: 2,5g/L of inoculante, T3: 5,0 g/L of inoculante and T4: 7,5 g/L of inoculante. After 60 days, the silos had been opened and samples removed for determination of pH, PB, FDN and FDA. The delineation was completely randomized, with four treatments and four repetitions. The different applied doses had resulted in significant difference (P 0,05) values of pH, PB, FDN and FDA.O objetivo do presente trabalho foi estudar o efeito de três doses do aditivo bacteriano comercial Sil-All (Alltech®), sobre o pH e a composição bromatológica da silagem de sorgo, variedade AG 2005. Foram utilizados 16 silos experimentais, com capacidade para 20kg de silagem. Os tratamentos testados foram T1: sem a adição de inoculante, T2: 2,5g/L de inoculante, T3: 5,0 g/L de inoculante e T4: 7,5 g/L de inoculante. Após 60 dias de ensilado, os silos foram abertos e retiradas amostras para determinação de pH, PB, FDN e FDA. O delineamento foi inteiramente casualizado, com quatro tratamentos e quatro repetições. As diferentes doses aplicadas resultaram em diferença significativa (P 0,05) os teores de pH, PB, FDN e FDA
Desempenho da mistura de aveia preta e azevém em função da adubação orgânica e mineral
An ultrasoft X-ray multi-microbeam irradiation system for studies of DNA damage responses by fixed- and live-cell fluorescence microscopy
Localized induction of DNA damage is a valuable tool for studying cellular DNA damage responses. In recent decades, methods have been developed to generate DNA damage using radiation of various types, including photons and charged particles. Here we describe a simple ultrasoft X-ray multi-microbeam system for high dose-rate, localized induction of DNA strand breaks in cells at spatially and geometrically adjustable sites. Our system can be combined with fixed- and live-cell microscopy to study responses of cells to DNA damage
Elucidating the role of metal ions in carbonic anhydrase catalysis
Why metalloenzymes often show dramatic changes in their catalytic activity when subjected to chemically similar but non-native metal substitutions is a long-standing puzzle. Here, we report on the catalytic roles of metal ions in a model metalloenzyme system, human carbonic anhydrase II (CA II). Through a comparative study on the intermediate states of the zinc-bound native CA II and non-native metal-substituted CA IIs, we demonstrate that the characteristic metal ion coordination geometries (tetrahedral for Zn2+, tetrahedral to octahedral conversion for Co2+, octahedral for Ni2+, and trigonal bipyramidal for Cu2+) directly modulate the catalytic efficacy. In addition, we reveal that the metal ions have a long-range (~10 ??) electrostatic effect on restructuring water network in the active site. Our study provides evidence that the metal ions in metalloenzymes have a crucial impact on the catalytic mechanism beyond their primary chemical properties. ?? 2020, The Author(s)
Design, fabrication and characterization of SAW pressure sensors for offshore oil and gas exploration
This work shows the design, development and measurements of an innovative pressure sensor for high pressure and high temperature environments for offshore oil and gas exploration. The proposed sensor is produced with a simple microfabrication process, which enables large-scale manufacturing, reducing production costs. The advantage of low cost production using these sensors is the ability to design distributed pressure sensors systems at affordable prices to monitor smart wells in oil and gas production. The proposed sensor consists of a two-port SAW device in contrast to the common BAW pressure sensors typically used in the oil and gas industry. A test capsule was designed to measure the device under pressure and the sensitivity obtained by the measurements was found to be 14.8 Hz/psi. The operation range was 0-15,000 psi and the device must operate on temperatures up to 150 C. Resolution was determined to be 1% of full scale. A capsule to package the sensor and circuits was designed and manufactured in 316L Stainless Steel. Results are very promising and expand the application of different kinds of sensors in the oil and gas industry222322328sem informaçã
Direct Hydrogenation of Carbon Dioxide by an Artificial Reductase Obtained by Substituting Rhodium for Zinc in the Carbonic Anhydrase Catalytic Center. A Mechanistic Study
Recently,
a new artificial carbonic anhydrase enzyme in which the
native zinc cation has been replaced with a Rh(I) has been proposed
as a new reductase that is able to efficiently catalyze the hydrogenation
of olefins. In this paper, we propose the possible use of this modified
enzyme in the direct hydrogenation of carbon dioxide. In our theoretical
investigation, we have considered different reaction mechanisms such
as reductive elimination and σ-bond metathesis. In addition,
the release of the formic acid and the restoring of the catalytic
cycle have also been studied. Results show that the σ-bond metathesis
potential energy surface lies below the reactant species. The rate-determining
step is the release of the product with an energy barrier of 12.8
kcal mol<sup>–1</sup>. On the basis of our results, we conclude
that this artificial enzyme can efficiently catalyze the conversion
of CO<sub>2</sub> to HCOOH by a direct hydrogenation reaction
Maxillary sinus mucocele with orbital complications.
INTRODUCTION:
Maxillary sinus mucocele is an unusual clinic entity (incidence of 3-10%), represented by mucous secretion lined by respiratory stratified pavemented epithelium and its origin is mainly secondary to infections, inflammations, surgery, trauma or neoplasia.
CASE REPORT:
We present a case of maxillary sinus mucocele. Subject of the study is a 74 aged patient referring positive anamnesis for nasal cavity surgery. His symptoms appeared six months ago and he complainted vertical ocular diplopia and ocular tension sensation, without rhinologic complaints. Oculistic examination confirmed an isolated left inferior rectus palsy, and CT showed mucous secretion occupying left maxillary sinus, with bone erosion to the orbital floor until orbital muscles. MRI is the gold standard for differential diagnosis with neoplastic lesions but the patient refused to perform this radio-diagnostic exam. He underwent to Endoscopic sinus surgery, consisting in middle meatal antrostomy and removal of the mucocele. Four months later the endoscopic follow-up showed regular maxillary cavity and regular ocular motility.
CONCLUSION:
In our opinion the rebuilding of the eroded bone is not mandatory if the integrity of the maxillary upper wall mucosa is respected, and antrostomy with drainage allows to recover ocular and paranasal sinus function. KEY WORDS:, Diplopia, Endoscopic sinus surgery
Cross-Shaped Terahertz Metal Mesh Filters: Historical Review and Results
Terahertz frequencies experiments has motivated the development of new sources, detectors and optical components. Here we will present a review of THz bandpass filters ranging from 0.4 to 10 THz. We also demonstrate our fabrication process, simulations and experimental results