Monitoring of Curing Process of Epoxy Resin by Long-Period Fiber Gratings.

The curing of epoxy resin is a complex thermo-chemical process that is difficult to monitor using existing sensing systems. We monitored the curing process of an epoxy resin by using long-period fiber gratings. The refractive index of the epoxy resin increases during the curing process and can be measured to determine the degree of curing. We employed long-period fiber gratings that are sensitive to the refractive index of an external medium for the measurement of refractive index changes in the resin. We observed that the resonances of long-period fiber gratings increased their depth with the increased refractive index of the resin, which was well described by our simulation taking the coupling to radiation modes into account. We demonstrated that the degree of cure can be estimated from the depth of the grating resonances using a phenomenological model. At the same time, long-period fiber gratings are sensitive to temperature variations and internal strains that are induced during curing. These factors may affect the measurements of curing degree and should also be addressed.

COVID-19 Coronavirus-Induced Atypical Pneumonia: Efficacy of the Monoclonal Antibody Bevacizumab in Moderate to Severe Cases.

COVID-19 novel coronavirus has created a global pandemic. Affected patients may develop acute lung injury and its more severe form - acute respiratory distress syndrome. Hypoxia and severe inflammation increase the production of vascular endothelial growth factor (VEGF), which induces vascular endothelial proliferation. Administration of the anti-VEGF monoclonal antibody bevacizumab is proposed for usage in moderate to severe pneumonia. We aim to present two cases of COVID-19 induced atypical pneumonia, which were treated with the anti-VEGF monoclonal antibody bevacizumab.

Bilateral metastasis to the retina, choroids and optic nerve from breast cancer: a clinicopathological case.

A 39-year-old Asian woman, with a known history of breast cancer, presented with a gradual onset of painless reduction in vision in both eyes. Examination revealed visual acuity of counting fingers in the right eye and light perception in the left. There were subretinal lesions in the posterior poles of both eyes and retinal detachment in the left eye. Later she developed left proptosis and restriction in left ocular movement, most likely to be caused by metastatic extraocular spread. She subsequently died from disseminated metastatic disease. Histopathological examination confirmed tumor cells infiltrating the choroids, retina and optic nerve in both eyes. The tumor cells were arranged in lobular fashion and stained positively with Periodic Acid Schiff, suggesting the primary to be lobular adenocarcinoma type. Choroidal metastatic disease is common but bilateral retinal and optic nerve involvement with extraocular spread from breast cancer is rare.

Choroidal metastasis of a gingival squamous cell carcinoma.

PURPOSE: To report a case of choroidal metastasis of a gingival squamous cell carcinoma. DESIGN: Interventional case report. METHODS: Review of the clinical history and pathologic findings. RESULTS: A 59-year-old woman with a history of right gingival squamous cell carcinoma presented with sudden dimness of vision in the left eye of 4 weeks duration. Fundus examination of the left eye revealed a yellowish elevated subretinal lesion involving the optic disk and macula. Fine-needle aspiration biopsy of the choroidal lesion, left eye, revealed metastatic squamous carcinoma cells. The patient was referred to a radiation oncologist for further management. CONCLUSION: Choroidal metastasis from gingival squamous cell carcinoma is rare, and it may develop from hematogeneous spread.