You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["HealthCareActivity", "InjuryOrPoisoning", "BodySubstance", "IntellectualProduct", "AnatomicalStructure", "SpatialConcept", "Chemical", "Bacterium", "MedicalDevice", "Organization", "BiomedicalOccupationOrDiscipline", "Finding", "BiologicFunction", "Virus", "ResearchActivity", "ClinicalAttribute", "PopulationGroup", "Eukaryote", "BodySystem", "Food", "ProfessionalOrOccupationalGroup"].

Please return the output as a JSON object of the format: {"Virus": ["HIV", ...], "Bacterium": ["MRSA", ...], "AnatomicalStructure": ["Lung", ...], "BodySystem": ["CNS", ...], "BodySubstance": ["Serum", ...], "Finding": ["Headache", ...], "InjuryOrPoisoning": ["Fracture", ...], "BiologicFunction": ["Death", ...], "HealthCareActivity": ["Biopsy", ...], "ResearchActivity": ["Clinical trial", ...], "MedicalDevice": ["Lenses", ...], "SpatialConcept": ["Camps", ...], "BiomedicalOccupationOrDiscipline": ["Forensic medicine", ...], "Organization": ["WHO", ...], "ProfessionalOrOccupationalGroup": ["Provider", ...], "PopulationGroup": ["Swimmers", ...], "Chemical": ["Gold", ...], "Food": ["Rice", ...], "IntellectualProduct": ["RPAM", ...], "ClinicalAttribute": ["Biomarker", ...], "Eukaryote": ["Dogs", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

The Corneal Epithelial Barrier and Its Developmental Role in Isolating Corneal Epithelial and Conjunctival Cells From One Another During development, the corneal epithelium (CE) and the conjunctiva are derived from the surface ectoderm. Here we have examined how, during development, the cells of these two issues become isolated from each other. Epithelia from the anterior eyes of chicken embryos were labeled with the fluorescent, lipophilic dye, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI). DiI was placed on the epithelial surface of the developing anterior eye and its diffusion was monitored by fluorescence microscopy. Concomitant morphologic changes in the surface cells of these epithelial were examined by scanning electron microscopy. Immunofluorescence was used to analyze the expression of cytokeratin K3, ZO-1, N-cadherin and Connexin-43 and the function of gap junctions was analyzed using a cut-loading with the fluorescent dye rhodamine-dextran. Prior to embryonic day 8 (E 8), DiI placed on the surface of the CE spreads throughout all the epithelial cells of the anterior eye. When older eyes were similarly labeled, dye diffusion was restricted to the CE. Similarly, diffusion of DiI placed on the conjunctival surface after E 8 was restricted to the conjunctiva. Scanning electron microscopy showed that developmentally (1) physical separations progressively form between the cells of the CE and those of the conjunctiva, and (2) by E 8 these separations form a ring that completely encompasses the cornea. The functional restriction of gap junctions between these tissues did not occur until E 14. During ocular development, a barrier to the diffusion of DiI forms between the contiguous CE and conjunctiva prior to the differential expression of gap junctions within these tissues.
{"AnatomicalStructure": ["surface ectoderm", "tissues", "Corneal Epithelial", "conjunctiva", "ring", "surface cells of these epithelial", "Conjunctival Cells", "anterior eye", "cornea", "epithelial cells", "anterior eyes", "corneal epithelium", "CE", "older eyes", "cells", "epithelial surface", "chicken embryos", "conjunctival", "Epithelia"], "Bacterium": [], "BiologicFunction": ["E", "expression", "ocular development", "function", "embryonic"], "BiomedicalOccupationOrDiscipline": [], "BodySubstance": [], "BodySystem": [], "Chemical": ["dye", "cytokeratin K3", "Connexin-43", "fluorescent dye", "lipophilic dye", "DiI", "fluorescent", "N-cadherin", "rhodamine-dextran", "ZO-1", "labeled", "1,1\u0027-dioctadecyl-3,3,3\u0027,3\u0027-tetramethylindocarbocyanine perchlorate"], "ClinicalAttribute": [], "Eukaryote": [], "Finding": ["examined"], "Food": [], "HealthCareActivity": ["fluorescence microscopy", "scanning electron microscopy", "Scanning electron microscopy", "Immunofluorescence"], "InjuryOrPoisoning": [], "IntellectualProduct": [], "MedicalDevice": [], "Organization": [], "PopulationGroup": [], "ProfessionalOrOccupationalGroup": [], "ResearchActivity": ["analyzed"], "SpatialConcept": ["surface", "gap junctions", "contiguous"], "Virus": []}