Fulfillment of assignment, quality of presentation, and scope of the thesis:

The student conducted a literature review that covers the scope of EPR spectroscopy
and its fundamentals, such as spin capture, but also lipid peroxidation and antioxidant
mechanisms. Regarding the implementation of the proposed methodology, the student
correctly performed the experiments for the generation and detection of radicals.
Furthermore, the analysis of the spectra obtained through EPR measurements was
developed using the EasySpin tool, which is based on MATLAB. To achieve this, he dedicated
all the necessary efforts and studies to learning and developing this method, in addition to
performing simulations and adjustments of the EPR spectra. Regarding the results obtained,
even though the main objective of detecting lipid peroxidation was not achieved, the student
was able to describe their experimental limitations, discuss probable reasons for the lack of
success in detection, and suggest possible directions for future corrections.
The main point is that he had many more measurements and didn’t add them or
discuss them because he did not have enough time to fit them, even after the consultants'
recommendation. Indeed, he did test the UV effect on linoleic acid + DMPO with and without
p-BQ. In this context, even though the work carried out fulfills the scope of a bachelor's
thesis very well, the work could have been even more detailed, bringing richness to the
discussion proposed by the student. On the other hand, the work as delivered meets all the
requirements expected of a bachelor's student, bringing an adequate scope to the thesis. In
general, he did work and learned a lot, learning EPR and the whole topic in less than 6
months (while still following his obligations as a student), thus having a considerable
mastery of operating the EPR, obtaining and interpreting the results coming from the EPR
device.

Student activity during the semester, applicability of the results, and any
implementation:

Throughout the semester, the student performed excellent work and demonstrated
mastery of laboratory activities, conducting experiments meticulously. Weekly meetings
were held where he consistently presented new results and discussions, including
hypotheses related to the experiments performed, as well as an increasingly strong
theoretical foundation. In this regard, the student excelled in striving to learn and master EPR
techniques, as well as programming using the MATLAB framework. However, regarding the
written work, there was negligence in writing the results obtained, as well as a lack of
adequate conclusion. This limited the potential of a very well-executed experimental work,
even though the desired phenomenon could not be visualized due to limitations in the
experimental setup. Concerning this, the expected results were satisfactory and the only
objective partially accomplished was the comparison of antioxidant effects, since this
depended on the result of the detection of lipid-derived radicals. However, these same
results showed important gaps to be considered for future research involving the study of
these radicals, which make the thesis of great value to be used as a basis for future students.

Use of literature, formatting of the technical report and its language level:

Finally, the work was written in a clear and well-organized manner, demonstrating the
student's excellent level of academic writing. The references used are highly relevant in this
academic field, and many of them are current, demonstrating that the student was aware of
the fundamental basis necessary for the development of the work, as well as recent and
important studies in the field. The formatting and standardization of the images can also be
considered a completely positive factor, although the captions could have contained a
slightly clearer description to facilitate reader comprehension. Points proposed by supervisor: 79

viz přiložený soubor Topics for thesis defence:

1. 1. In the methodology section, the supplier of DMPO is not specified. Since high-purity DMPO is important for reliable EPR measurements, was the purity of DMPO verified before the experiments? Was any purification procedure performed prior to the measurements?
2. 2. What experimental parameters were used for acquisition of the spectra presented in the Figure 4.1. What was the rate of 1 scan? Since time constant can affect the resolution.
3. 3. What other parameters besides the viscosity can affect the stability of the spin adducts?
4. 4. What alternative radical initiation methods for hydroxyl radical production, besides the Fenton reaction, would you consider? Can decomposition of H2O2 under UV light be used?

Points proposed by reviewer: 85