Authors of a 2018 paper have retracted it after discovering “the conclusions in the article cannot be relied upon.”
The journal, PeerJ, wasted no time. Less than a week after the paper was published, the journal issued an expression of concern to alert readers to the issue and to the forthcoming retraction notice, which appeared five days later, on January 23.
PeerJ is typically associated with preprints—which the journal defines as “a draft that has not yet been peer reviewed for formal publication”—but the 2018 paper was never a preprint, the publisher said. The paper was peer reviewed, after the authors submitted it last October.
So, what prompted such a speedy retraction?
Jianchao Zhang, the paper’s first author who works at Tianjin University in China, told Retraction Watch that immediately after the paper was published on January 12, readers who had used the same nanotubes informed them that they might be faulty. Zhang explained that after confirming the electrical conductivity of the nanotubes was too low, the authors notified the journal about the issue and asked for their paper to be retracted.
Peter Binfield, co-founder and publisher of PeerJ, told Retraction Watch:
This was a clear-cut issue, and the authors were proactive and diligent in swiftly requesting a retraction to correct the record before others tried to use their results.
After the authors notified Binfield of the problem, the journal published an expression of concern on January 18, followed by a formal retraction notice on January 23.
We’ve only found two other retractions for PeerJ since it began publishing in 2013. Both retractions appeared in PeerJ in 2016—a 2015 paper, originally published as a preprint, and 2016 paper, which the journal first flagged with an expression of concern.
Here’s the latest retraction notice:
Immediately after publication, readers alerted the authors that the nanotubes used in their experiments may not have possessed the electrical conductivity that the authors had assumed (based on the manufacturer’s data). The authors tested the nanotubes in question, and confirmed that their electrical conductivity is too low to be able to rely on their results. As a result, the conclusions in the article cannot be relied upon, and all the authors have agreed to retract this article. The authors would like to thank the readers who alerted them to this issue.
This Retraction updates an Expression of Concern which was issued on January 18th 2018.
The paper, “Response of methane production via propionate oxidation to carboxylated multiwalled carbon nanotubes in paddy soil enrichments,” was first flagged with an expression of concern five days earlier:
The authors of this article have reported that the electrical conductivity of the nanotubes used in these experiments cannot be relied upon. As a result, readers should not rely on the conclusions of this article. A formal notice regarding this article will follow.
Binfield explained that although the manuscript was peer reviewed by three reviewers and an academic editor, “this issue wouldn’t necessarily have been flagged unless the reviewers had specific experience with that material from that supplier.”
Junkuo Gao, the paper’s academic editor, added that the electronic properties of the nanotubes were “the most important parameters.”
First author Zhang told us that he cannot be sure if the nanotubes were defective when he got them from the supplier, or if another factor affected the quality. (We contacted the company that supplied the nanotubes, DK Nano Technology Co., but have not yet heard back.)
Regardless, Zhang explained, the team will discard the data used in the now-retracted paper and repeat the experiments with new nanomaterials. The lesson from this experience, Zhang said, was to check materials more closely before performing experiments:
We just know we can do it better to avoid those things at that time…
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