RESUMO
Psychiatric comorbidity is common in cancer patients, emphasizing the need for comprehensive care. While depressive symptoms in pancreatic cancer have been studied, there is limited attention given to manic symptoms. This case report aims to contribute to the knowledge of pancreatic cancer psychiatric comorbidities by describing a case of a patient with stage IV pancreatic cancer who presented a sudden onset manic episode. The patient, a 61-year-old male with stage IV pancreatic cancer, presented at the Emergency Room with abrupt behavioural changes suggestive of a manic episode of 2â weeks of evolution. The patient had been undergoing chemotherapy and short 3-day cycles of corticosteroids for the past 9â months but had been off this treatment for 20â days when the episode began. Acute organic causes were ruled out. The patient was admitted to the psychiatric unit, where organic screening was expanded and treatment with antipsychotics and a mood stabiliser was initiated with subsequent remission of symptoms after 2â weeks. This case shows a manic episode as a rare psychiatric complication in pancreatic cancer. In the literature reviewed, four other similar cases have been observed. Further research is needed to elucidate the underlying pathophysiology and explore possible treatment strategies.
RESUMO
The effect of Nb content on microstructure, mechanical properties and superelasticity was investigated for a series of Ti-xNb alloys, fabricated by the laser engineered net shaping method, using elemental Ti and Nb powders. The microstructure of as-deposited materials consisted of columnar ß-phase grains, elongated in the built direction. However, due to the presence of undissolved Nb particles during the deposition process, an additional heat treatment was necessary. The observed changes in mechanical properties were explained in relation to the phase constituents and deformation mechanisms. Due to the elevated oxygen content in the investigated materials (2 at.%), the specific deformation mechanisms were observed at lower Nb content in comparison to the conventionally fabricated materials. This made it possible to conclude that oxygen increases the stability of the ß phase in ß-Ti alloys. For the first time, superelasticity was observed in Ti-Nb-based alloys fabricated by the additive manufacturing method. The highest recoverable strain of 3% was observed in Ti-19Nb alloy as a result of high elasticity and reverse martensitic transformation stress-induced during the loading.
RESUMO
With the purpose to optimize the functional properties of Heusler alloys for their use in solid-state refrigeration, the characteristics of the martensitic and magnetic transitions undergone by Ni50Mn25-xGa25Cux (x = 3-11) alloys have been studied. The results reveal that, for a Cu content of x = 5.5-7.5, a magnetostructural transition between paramagnetic austenite and ferromagnetic martensite takes place. In such a case, magnetic field and stress act in the same sense, lowering the critical combined fields to induce the transformation; moreover, magnetocaloric and elastocaloric effects are both direct, suggesting the use of combined fields to improve the overall refrigeration capacity of the alloy. Within this range of compositions, the measured transformation entropy is increased owing to the magnetic contribution to entropy, showing a maximum at composition x = 6, in which the magnetization jump at the transformation is the largest of the set. At the same time, the temperature hysteresis of the transformation displays a minimum at x = 6, attributed to the optimal lattice compatibility between austenite and martensite. We show that, among this system, the optimal caloric performance is found for the x = 6 composition, which displays high isothermal entropy changes (-36 J·kg-1·K-1 under 5 T and -8.5 J·kg-1·K-1 under 50 MPa), suitable working temperature (300 K), and low thermal hysteresis (3 K).
RESUMO
Linear and non-linear internal friction and the effective Young's modulus of a Ni50.8Ti49.2 alloy have been studied after different heat treatments, affecting hydrogen content, over wide ranges of temperatures (13-300 K) and strain amplitudes (10-7-10-4) at frequencies near 90 kHz. It has been shown that the contamination of the alloy by hydrogen strongly affects the internal friction and Young's modulus of the martensitic phase. Presence of hydrogen gives rise to a non-relaxation internal friction maximum due to a competition of two different temperature-dependent processes. The temperature position and height of the maximum depend strongly on the hydrogen content. We conclude that many of the internal friction peaks, reported earlier for differently treated Ni-Ti-based alloys, had the same origin as the present maximum.
