Embedded Fiber Sensors to Monitor Temperature and Strain of Polymeric Parts Fabricated by Additive Manufacturing and Reinforced with NiTi Wires.

This paper focuses on three main issues regarding Material Extrusion (MEX) Additive Manufacturing (AM) of thermoplastic composites reinforced by pre-functionalized continuous Nickel-Titanium (NiTi) wires: (i) Evaluation of the effect of the MEX process on the properties of the pre-functionalized NiTi, (ii) evaluation of the mechanical and thermal behavior of the composite material during usage, (iii) the inspection of the parts by Non-Destructive Testing (NDT). For this purpose, an optical fiber sensing network, based on fiber Bragg grating and a cascaded optical fiber sensor, was successfully embedded during the 3D printing of a polylactic acid (PLA) matrix reinforced by NiTi wires. Thermal and mechanical perturbations were successfully registered as a consequence of thermal and mechanical stimuli. During a heating/cooling cycle, a maximum contraction of ≈100 µm was detected by the cascaded sensor in the PLA material at the end of the heating step (induced by Joule effect) of NiTi wires and a thermal perturbation associated with the structural transformation of austenite to R-phase was observed during the natural cooling step, near 33.0 °C. Regarding tensile cycling tests, higher increases in temperature arose when the applied force ranged between 0.7 and 1.1 kN, reaching a maximum temperature variation of 9.5 ± 0.1 °C. During the unload step, a slope change in the temperature behavior was detected, which is associated with the material transformation of the NiTi wire (martensite to austenite). The embedded optical sensing methodology presented here proved to be an effective and precise tool to identify structural transformations regarding the specific application as a Non-Destructive Testing for AM.

Inverted internal limiting membrane flap for the management of optic disc pit maculopathy / Técnica do flap invertido da membrana limitante interna para o manejo da maculopatia causada pela fosseta do disco óptico

ABSTRACT Optic disc pit is a rare congenital anomaly that can cause serous macular detachment. It has no universally accepted single treatment. Recently, several investigators have performed new procedures to directly seal the pit. Herein, we report a case showing a promising method for optic pit maculopathy surgical treatment. We created an inverted internal limiting membrane flap and fold it over the pit to promote barrier in order to stop further fluid accumulation. Gradual absorption of subretinal fluid was observed over 12 months of follow-up. Optical coherence tomography can demonstrate internal limiting membrane folded over the pit and progressive subretinal fluid resolution. This technique resulted in a satisfactory anatomic outcome with good functional improvement in the best-corrected visual acuity.

RESUMO A fosseta do disco óptico é uma rara anomalia con gênita que pode causar descolamento de retina seroso na mácula. Não há um tratamento cirúrgico padrão universalmente aceito. Recentemente, cirurgiões têm realizado procedimentos novos que visam selar o buraco diretamente. Esse caso clínico mostra um método promissor para o tratamento cirúrgico da maculopatia causada pela fosseta do disco. Optamos por criar um flap invertido com a membrana limitante interna, dobrando-o sobre a fosseta para promover uma barreira, impedindo o acúmulo de fluido. A absorção gradual do líquido subretiniano foi observada ao longo de 12 meses de acompanhamento. Imagens de tomografia de coerência óptica podem demonstrar a membrana limitante interna dobrada sobre a fosseta e a resolução progressiva do fluido subretiniano. Esta técnica resultou em um resultado anatômico satisfatório com boa melhora funcional na acuidade visual.

Inverted internal limiting membrane flap for the management of optic disc pit maculopathy.

Optic disc pit is a rare congenital anomaly that can cause serous macular detachment. It has no universally accepted single treatment. Recently, several investigators have performed new procedures to directly seal the pit. Herein, we report a case showing a promising method for optic pit maculopathy surgical treatment. We created an inverted internal limiting membrane flap and fold it over the pit to promote barrier in order to stop further fluid accumulation. Gradual absorption of subretinal fluid was observed over 12 months of follow-up. Optical coherence tomography can demonstrate internal limiting membrane folded over the pit and progressive subretinal fluid resolution. This technique resulted in a satisfactory anatomic outcome with good functional improvement in the best-corrected visual acuity.

Topical steroids eye drops in conjunctival reactive lymphoid hyperplasia: Case report.

RATIONALE: Conjunctival lymphoproliferative lesions constitute a significant diagnostic challenge and it is essential to exclude neoplastic lesions. Histopathological and immunohistochemical tests are very useful in establishing the correct diagnosis. Reactive lymphoid hyperplasia (RLH) is part of a spectrum of lymphocytic infiltrative disorders. Evidence is scarce regarding appropriate treatment of conjunctival RLH. We report a case treated with topical corticosteroid. PATIENT CONCERNS: A 40 year-old female presented with a 7-month history of a slow growth tumor in the superior conjunctiva of the right eye. Slit-lamp examination demonstrated salmon colored lesion in the upper conjunctiva, with little conjunctival injection, but no significant neovascularization. There was no eyelid involvement. DIAGNOSES: Ultrasound biomicroscopy showed lesion depth (1.53 mm) and larger diameter (10.73 mm). Pathological examination revealed a chronic inflammatory process with conjunctival folicular hyperplasia. The immunohistochemistry examination showed predominance of CD20, CD23, and CD 3 e CD 5. INTERVENTION: We started topic prednisolone 1% 6 times daily. OUTCOMES: Six months after starting treatment, the lesion completely resolved, without any side-effects or recurrence during three-year follow-up period. LESSONS: Conjunctival RLH can be managed in various ways, depending on patient symptonm, comorbities, and disease distribution. Surgical resection with cryotherapy, radiotherapy, systemic corticosteroids, subconjunctival triamcinolone, and rituximab are some options. There is no strong evidence in the literature of conjunctival RLH successfully treated with topical eye drops corticosteroid. In this report, we obtained completely resolution of conjunctival RLH with topical corticosteroid. CONCLUSION: Topical eye drops corticosteroids are an alternative treatment for selected cases of conjuncitval RLH with no orbital or eyelid involvement.

Internal and External Temperature Monitoring of a Li-Ion Battery with Fiber Bragg Grating Sensors.

The integration of fiber Bragg grating (FBG) sensors in lithium-ion cells for in-situ and in-operando temperature monitoring is presented herein. The measuring of internal and external temperature variations was performed through four FBG sensors during galvanostatic cycling at C-rates ranging from 1C to 8C. The FBG sensors were placed both outside and inside the cell, located in the center of the electrochemically active area and at the tab-electrode connection. The internal sensors recorded temperature variations of 4.0 ± 0.1 °C at 5C and 4.7 ± 0.1 °C at 8C at the center of the active area, and 3.9 ± 0.1 °C at 5C and 4.0 ± 0.1 °C at 8C at the tab-electrode connection, respectively. This study is intended to contribute to detection of a temperature gradient in real time inside a cell, which can determine possible damage in the battery performance when it operates under normal and abnormal operating conditions, as well as to demonstrate the technical feasibility of the integration of in-operando microsensors inside Li-ion cells.