Retraction Watch

Tracking retractions as a window into the scientific process

Research misconduct finding — which university won’t discuss — leads to second retraction for prominent physicist

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A rising star in nanotechnology, Dmitri Lapotko, has received his second retraction within a month over “a finding of research misconduct” that the university will apparently only disclose on a need-to-know basis.

According to the notice, the journal’s editor and publisher issued the retraction after Lapotko’s former institution—Rice University in Houston—notified them of research misconduct and cited figure duplication issues, which meant the results “should not be relied upon and may be scientifically unsound.”

We recently covered the Belarusian physicist’s first retraction in the journal Theranostics, in which an official at Rice would not confirm a misconduct inquiry, telling us that, “Rice University’s investigations of research misconduct are confidential.”

This time, however, the retraction notice explicitly states that a Rice University research integrity officer reported research misconduct to the journal Applied Physics Letters (APL). We contacted the official, B.J. Almond, who still stuck to the original script:

We do not comment on the existence or nature of a specific investigation, except to communicate directly to parties who are affected by the investigation.

Almond added, however, that overall the university is dedicated to upholding research integrity and handling cases of “alleged research misconduct.”

Here’s the retraction notice for “Experimental techniques for imaging and measuring transient vapor nanobubbles,” published in APL in 2012:

The Editor and the Publisher of Applied Physics Letters (APL) are retracting the referenced paper1 based on a finding of research misconduct reported to APL by the Rice University Research Integrity Officer. In particular, the trace in Fig. 2(b-II) was found to be a duplicate of Fig. S5a in the supplementary materials for Ref. 2 even though the axes scales in the figures are different and each figure reports results from a different type of sample. Similarly, the trace in Fig. 3(a-I) was found to closely overlap the trace in Fig. 4(a) of Ref. 3 even though they are reported to originate from different samples and, again, have different axes scales. As a consequence of these findings, the results presented in Ref. 1 should not be relied upon and may be scientifically unsound.

The paper, on which Lapotko is corresponding author, has been cited 16 times, according to Clarivate Analytics’ Web of Science, formerly part of Thomson Reuters:

Over the past few years, Lapotko’s work has caught the eye of funders, the media and experts in his field. Since establishing The Nanobubble Lab at Rice in 2009, he has been awarded just over $2.67 million in NIH grant money for various projects. His research, exploring innovative ways to harness nanotechnology to diagnose and treat a range of diseases such as malaria and cancer, has appeared in The New York Times in 2014 and in Science last year.

Last year, however, cracks in Lapotko’s research began to emerge. On top of the two recent retractions, Lapotko has received several corrections (1, 2) and an EOC, which we reported. We also found two other long corrections for Lapotko (1, 2), detailing figure-related errors and duplication (detailed below), and several papers questioned on PubPeer.

To find out where things went wrong, we contacted Lapotko and his co-author Ekaterina Y. Lukianova-Hleb at her Rice account, but her e-mail bounced back. We also reached out to APL and representatives at the device company Masimo Corp., where Lapotko now works, for more information, but have yet to hear back.

Although Almond would not comment on the “existence or nature of a specific investigation,” he told us that the university is devoted to maintaining and protecting research integrity:

As a general matter, I can assure you that as a private research university, Rice is committed to the highest principles of integrity in its research and scholarly activities and has procedures in place for dealing with alleged research misconduct and for complying with the policies of federal sponsoring agencies. Rice takes allegations of misconduct very seriously and follows up with internal investigations when necessary. All faculty, staff and students are expected to abide by the principles of intellectual integrity.

Here are the complete 2016 corrigenda for the two 2010 papers, detailing figure-related errors:

  1. Corrigendum for “Generation and detection of plasmonic nanobubbles in zebrafish,” published in Nanotechnology and cited 11 times:

Due to the identical physical mechanisms of the generation of plasmonic nanobubbles, and the identical detection methodologies, their illustrative time-responses look similar (while they are not identical) even under different experimental setting as in figure 3(a) of the article titled ‘Generation and detection of plasmonic nanobubbles in zebrafish’, Nanotechnology (2010) 21 225102 and the figure 2(c) of our prior article [1]. This similarity, as well as an illustrative nature of the above figures (which represent typical time-responses of single plasmonic nanobubbles) does not affect the results and conclusions of subject articles (which were based on the quantitative analysis of hundreds and thousands of plasmonic nanobubbles studied with several independent methodologies).

Due to several technical errors in the illustrative figures in the article, the following corrections have been applied:

  1. Figures 6(c) and (g): misprinting in the Y axis labels in ‘C.w. probe laser amplitude, count’ was corrected to ‘C.w. probe laser amplitude, V’; misprinting in the X axis labels ‘Time, ns’ was corrected to ‘Time, μs’.
  2. Figure 6(c): (illustrates a typical null time-response to a laser pulse) mistakenly plotted from the data set related to figure 5(d) (a similar null response) is replaced with a similar time-response obtained during the same experiment as described in the figure legend.
  3. Figure 4(d): (illustrates a typical plasmonic nanobubble time-response) mistakenly plotted from the data set related to a similar plasmonic nanobubble registered in another experiment is replaced with a similar time-response obtained during the experiment in the figure legend.

These figures were used only to illustrate the experiments and did not affect any of the article’s results or conclusions. The authors would like to apologize for any inconvenience caused.

  1. Corrigendum for “Optically guided controlled release from liposomes with tunable plasmonic nanobubbles” published in Journal of Controlled Release and cited 57 times:

The authors regret that the original version of the article contains several typos and technical errors in the Fig 2 and Fig. 7:

-Figs. 2d–f and 7c: “Amplitude, mV″ should read “Amplitude, V”.

-Fig. 2e was mistakenly plotted from the data set related to the Fig. 7a due to their high similarity.

-Fig. 2f was mistakenly plotted from the data set for plasmonic nanobubble obtained in another experiment due to the high similarity of time-responses of plasmonic nanobubbles.

The figures were used only to illustrate the detection of single plasmonic nanobubbles and did not support the article’s results or conclusions. To correct the above mentioned technical errors, the figures are being replaced with the similar ones obtained in the experiments described in the article and in the corresponding figure legends.

The authors would like to apologize for any inconvenience caused.

Hat tip: Rolf Degen

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