Review for 10.1186/s12876-021-01642-7 (2021)

Reviewer’s report
Title: 
68Ga-NOTA PET imaging for gastric emptying assessment in mice
Version: 
1 
Date: 
30 Nov 2020
Reviewer's report:
PEER REVIEWER ASSESSMENTS: 
OBJECTIVE - Full research articles: is there a clear objective that addresses one
or several testable research questions? (Brief or other article types: is there a
clear objective?)
Yes - there is a clear objective
DESIGN - Is the current approach (including controls and analysis protocols)
appropriate for the objective?
No - there are minor issues
EXECUTION - Are the experiments and analyses performed with sufficient
technical rigor to allow confidence in the results?
No - there are minor issues
STATISTICS - Is the use of statistics in the manuscript appropriate?
No - there are issues with the statistics in the study
INTERPRETATION - Is the current interpretation/discussion of the results
reasonable and not overstated?
No - there are minor issues
OVERALL MANUSCRIPT POTENTIAL - Has the author addressed your
concerns sufficiently for you to now recommend the work as a technically sound
contribution? If not, can further revisions be made to make the work technically
sound?
Probably - with minor revisions
PEER REVIEWER COMMENTS: 
GENERAL COMMENTS: The authors responded adequately, but in many cases
they did not make changes to reflect their responses 
nor have they improved my
overall impression of the manuscript.
REQUESTED REVISIONS: 
Many of the comments from the last review were either not directly addressed in
the responses and/or the Manuscript. These include the appropriateness of saline
control when the test substance is oil based, the validation of the PET
quantification modalities, the repeatability and variation in analysis, variation
between controls and treatment animal groups at the study onset and
disproportionate %ID/g values. The stats section is also over simplified/poorly
explained.
ADDITIONAL REQUESTS/SUGGESTIONS: 
The language quality is still very poor and was not addressed adequately (nor is
there any indication in the revised copy that an attempt was made). 
Many of the
responses to the reviewers from the last round were addressed to the reviewer,
without any clarification within the manuscript. 
Errors like use of the the word
"proved" in line 88 in reference to study results remain (studies provide evidence
in support of conclusions not proof of those conclusions).
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Declaration of competing interests
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questions:
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. 
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salary from an organisation that may in any way gain or lose financially
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Do you have any non-financial competing interests in relation to this
paper?
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recommendation.
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Is the study design appropriate to answer the research question (including the use
of appropriate controls), and are the conclusions supported by the evidence
presented?
No
Are the methods sufficiently described to allow the study to be repeated?
No
Is the use of statistics and treatment of uncertainties appropriate?
No
Is the presentation of the work clear?
No
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes