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: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. 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:

Toxicological, toxicokinetic and gastroprotective evaluation of the benzaldehyde semicarbazone. Benzaldehyde semicarbazone (BS) has presented positive results in several pharmacological models, including anticonvulsivant and anti-inflammatory models. The present study evaluated the preclinical toxicity (acute and subchronic), as well as the toxicokinetic and gastroprotective effects of BS against ethanol lesions. Oral doses of 300 and 2000mg/kg were used in the preclinical acute toxicity study; 100, 200, and 300mg/kg were used in both the subchronic toxicity evaluation and the gastric study; and 300mg/kg was used in the toxicokinetic study. No impact from the dose of 300mg/kg could be identified; while, one animal died at 2000mg/kg in the acute toxicity test. In the subchronic toxicity test, changes in the biochemical parameters of the liver, as well as in the histopatological evaluation, demonstrated that BS is a hepatotoxic drug. BS proved to be effective for moderate and severe gastric lesions. In the toxicokinetics study, BS presented a low concentration and rapid plasma disappearance. Several results also indicate that BS is likely to be mostly eliminated from the liver and may well undergo a first-pass effect after oral absorption. It was impossible to estimate the noobserved-adverse-effect-levels (NOAEL) and lowest-observed-adverse-effect-levels (LOAEL) due to the presence of hepatotoxicity in all tested doses.
{"Chemical": ["ethanol", "benzaldehyde semicarbazone", "Benzaldehyde semicarbazone"]}