Archive for the ‘wrong reagents’ Category
Authors have retracted a highly cited Nature letter that purported to discover a much sought-after, stable light source from quantum dots, after they realized the light was actually coming from another source: the glass the dots were affixed to.
When the paper “Non-blinking semiconductor nanocrystals” was published in 2009, it received some media coverage, such as in Chemistry World. That’s partly because very small sources of “non-blinking” light could have wide-ranging, big-picture applications, author Todd Krauss, a physical chemist at the University of Rochester, told us:
Off the top of my head, a quantum computer. Quantum cryptography is another one. People want a stable light source that obeys quantum physics, instead of classic physics.
The retraction note, published Wednesday, explains how the researchers found out the effect was coming from the glass, not quantum dots:
The reasons for the retractions range from expired kits, an “unattributed overlap” with another paper, “authorship issues,” and issues over sample sizes.
Tomader Taha Abdel Rahman, a researcher at Ain Shams University in Cairo, is the first author on two of the papers, and second author on the third.
Here’s the retraction note for a paper that showed elderly adults with chronic hepatitis C are at risk of having cognitive issues:
The author of an article mapping the genome of an infectious bacterium is pulling the paper because — well, it wasn’t the bacterium she thought it was.
Study author Celia Abolnik is retracting her paper in Genome Announcements because it didn’t actually map out the DNA of Mycoplasma meleagridis, a bacterium that typically infects turkeys but has recently been found in chickens.
The trouble was, the sequence for Mycoplasma meleagridis in the National Institute of Health’s DNA database, Genbank, was actually a different variety of bacteria — Mycoplasma gallinaceum, another scourge of poultry.
Researchers at the National Institute of Environmental Health Sciences have retracted a 2014 article after a review unearthed unresolved problems with the study’s control material.
The retracted paper, “Effect of Temperature and Storage Time on Sorbitol Dehydrogenase Activity in Sprague-Dawley Rat Serum and Plasma,” looked to test the durability and stability of sorbitol dehydrogenase, an enzyme used to detect cancerous liver damage in rats.
Upon realizing they had experienced a case of mistaken cell-line identity, the authors of a 2014 Nature paper on lung cancer think “it prudent to retract pending more thorough investigation,” as they explain in a notice published Wednesday.
The problem seems to stem from more than just honest error, according to corresponding author Julian Downward, a scientist at the Francis Crick Institute in the UK.
In a 1,215 word statement, sent to us via the Director of Research Communications and Engagement at Cancer Research UK, which funds Downward’s research, Downward told us the backstory not presented in the journal’s retraction note:
As every mushroom lover knows, weekend mycology is no sport for the lily-livered. Tasty species often look awfully like their deadly cousins. Turns out, typing can even be problematic for the experts.
The paper, “Chemical constituents: water-soluble vitamins, free amino acids and sugar profile from Ganoderma adspersum,” was written by Ibrahim Kivrak, a food chemist at Mugla Sitki Kocman University in Mugla, Turkey. It analyzed the nutritional components of G. adspersum, and found, per the abstract:
Although they are confident that the strategy is sound, the authors write in their commendably detailed retraction notice that the “inadvertent error” rendered the results “uninterpretable.”
Authors of a 2010 Chemistry – A European Journal article have retracted it “due to the wrong assignment of structure” of catalysts.
The retraction is the third, by our count, for corresponding author Doo Ok Jang, a chemist at Yonsei University in Wonju. Jang authored one of the previously retracted papers with Sung Jun Kim and the other with Sang Yoon Kim. Both papers were also sunk by misassigned structures.
The current study, “Enantioselective Radical Addition to Ketimines: A Synthetic Route Towards α,α-Disubstituted α-Amino Acids,” is authored by all three chemists. Here’s the retraction notice:
The notice is clear on the problems with the science, which together “call into question the main conclusions of the paper.” Three of the paper’s five authors were employed at Novartis at the time of publication.
We’ve written before about how common cell line mix ups are in cancer research; according to a 2012 Wall Street Journal article (paywalled), between a fifth and a third of cancer cell lines tested by suspicious researchers turned out to be misidentified.
Obviously, mistakenly studying the wrong kind of cancer is a waste of precious resources, both time and money. And it’s clear the problem hasn’t gone away. PLoS ONE just retracted a cancer paper originally published in December 2012 for studying two cell lines that had been contaminated by other cell types.