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: ["Outcome", "Participant", "Intervention"].

Please return the output as a JSON object of the format: {"Participant" : ["patients with COPD", ...], "Intervention" : ["Atenolol", ...], "Outcome" : ["blood pressure", ...]}. 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:

Histopathologic changes of the eyelid skin following trichloroacetic acid chemical peel . The use of trichloroacetic acid ( TCA ) as a periorbital and eyelid peel for skin rejuvenation is gaining significant acceptance among oculoplastic surgeons , dermatologists , and other surgery groups . In spite of the current enthusiasm , there remain potentially serious complications resulting from any periorbital peel . Cases of cicatricial ectropion have been reported in phenol-peeled patients , and lower eyelid ectropion has reportedly occurred in patients undergoing deep eyelid peel in conjunction with a blepharoplasty ( 1,2 ) . To avoid this complication , it is necessary to better understand the depth of the wound produced by different strengths and combinations of peeling agents applied to living eyelid tissue and , more important , to determine the concentrations of TCA that are likely to lead to cicatricial ectropion when applied in a consistent fashion . We chose upper-eyelid skin because it is easier to obtain for histopathologic study than lower-eyelid skin and , in our experience , is more sensitive to hypertrophic changes after chemical peeling or carbon dioxide laser resurfacing . We applied TCA to the preseptal skin of 10 patients 48 h before standard upper-eyelid blepharoplasty . The acid was applied to produce a " frost , " using varying concentrations of acid , ranging from 20 to 50 % . The treated skin removed at the time of blepharoplasty was reviewed in a masked fashion by a dermatopathologist to determine the depth of necrosis . We found that superficial peels with necrosis involving 30 % of the epidermis were produced by the lowest-concentration combination of TCA applied ( 20 % followed by 0 % ) . As the strength increased , so did the depth of peel . The combination of 50 % followed by a second application of 50 % produced the deepest peel , with necrosis into the papillary dermis . This finding would indicate that the chance of developing cicatricial ectropion with any of the tested combinations of TCA should be very remote .
{"Intervention": ["trichloroacetic acid ( TCA )", "trichloroacetic acid chemical peel", "TCA", "blepharoplasty"], "Outcome": ["strength increased", "deepest peel", "superficial peels with necrosis", "applied", "Histopathologic changes of the eyelid skin"], "Participant": ["10", "phenol-peeled", "deep eyelid peel", "eyelid skin"]}