My regex pattern is constructed with alternation to match the four distinct groups:

1. Calc expressions: `\{calc\(\d\*\(\d\+\d\)\)\}|\{calc\(\d\+\(\d\*\[\d-\d\]\)\)\}` - These match the exact structure of the calc expressions with proper escaping of special characters.

2. Blood pressure readings: `\d{2,3}\/\d{2,3}mmHg|\d{2,3}\/\d{2,3} mmHg` - This matches the blood pressure format with digits separated by a slash, with or without a space before "mmHg".

3. Scientific notation numbers: `[+-]?\d+\.\d+[Ee][+-]\d+|[+-]?\d+[Ee][+-]?\d+|[+-]?\d+\.\d+e\d+` - This matches different scientific notation formats including optional signs, decimal points, and various exponent formats.

4. ISBN numbers: `\d-\d{6}-\d{2}-[\dX]|\d-\d{3}-\d{5}-X|978-\d-\d{2}-\d{6}-\d|979-\d-\d{3}-\d{5}-\d|979-\d-\d{6}-\d{2}-\d` - This matches the various ISBN formats in the list.

The entire pattern combines all these alternatives with the pipe character (|) to match exactly the target items without matching any other text in the sample.