ABSTRACT
The deconvolution process is a key step for quantitative evaluation of fluorescence lifetime imaging microscopy (FLIM) samples. By this process, the fluorescence impulse responses (FluoIRs) of the sample are decoupled from the instrument response (InstR). In blind deconvolution estimation (BDE), the FluoIRs and InstR are jointly extracted from a dataset with minimal a priori information. In this work, two BDE algorithms are introduced based on linear combinations of multi-exponential functions to model each FluoIR in the sample. For both schemes, the InstR is assumed with a free-form and a sparse structure. The local perspective of the BDE methodology assumes that the characteristic parameters of the exponential functions (time constants and scaling coefficients) are estimated based on a single spatial point of the dataset. On the other hand, the same exponential functions are used in the whole dataset in the global perspective, and just the scaling coefficients are updated for each spatial point. A least squares formulation is considered for both BDE algorithms. To overcome the nonlinear interaction in the decision variables, an alternating least squares (ALS) methodology iteratively solves both estimation problems based on non-negative and constrained optimizations. The validation stage considered first synthetic datasets at different noise types and levels, and a comparison with the standard deconvolution techniques with a multi-exponential model for FLIM measurements, as well as, with two BDE methodologies in the state of the art: Laguerre basis, and exponentials library. For the experimental evaluation, fluorescent dyes and oral tissue samples were considered. Our results show that local and global perspectives are consistent with the standard deconvolution techniques, and they reached the fastest convergence responses among the BDE algorithms with the best compromise in FluoIRs and InstR estimation errors.
Subject(s)
Fluorescent Dyes/chemistry , Image Processing, Computer-Assisted/methods , Models, Chemical , Algorithms , Datasets as Topic , Humans , Least-Squares Analysis , Microscopy, Fluorescence , Mouth Mucosa/pathology , Mouth Neoplasms/pathology , Time FactorsABSTRACT
Gonococcal keratoconjunctivitis is a rapidly progressing and aggressive infection caused by Neisseria gonorrhoeae . We report a case of a patient who presented keratoconjunctivitis with an opacity in the left cornea that progressed into an ulcerative lesion despite initial treatment with antibiotic eye drops. Gram stains from the purulent discharge of the left eye showed gram-negative diplococci, and the culture from the ocular discharge was positive for Neisseria gonorrhoeae . Resolution was achieved with the administration of 2 g of intramuscular ceftriaxone in a single dose, and the patient had no sequelae.
La queratoconjuntivitis gonocócica es un infección agresiva y de rápida progresión causada por Neisseria gonorrhoeae . Reportamos el caso de un paciente quien presentó queratoconjuntivitis con opacidad corneal izquierda, la cual progresó a lesión ulcerativa a pesar del tratamiento inicial con antibiótico en gotas oftálmicas. La tinción de Gram y el cultivo a partir de la secreción purulenta del ojo izquierdo mostró diplococos gramnegativos y crecimiento de Neisseria gonorrhoeae , respectivamente. La curación del paciente se logró tras la administración de 2 g de ceftriaxona intramuscular en dosis única; el paciente no presentó secuelas.
