Surprisingly, these microRNAs boost — ra- ther than dampen — protein expression Putting the brakes on lithium-ion batteries

From the ACS Press Room Surprisingly, these microRNAs boost — rather than dampen — protein expression

“High-Throughput Analysis Reveals miRNA Upregulating a-2,6 Sialic Acid Through Direct miRNA: miRNA Interactions”

ACS Central Science

MicroRNAs can play a role in cancer development and are thought to exclusively suppress protein expression in dividing cells, such as tumor cells. But new research published in ACS Central Science shows that some of these tiny molecules can elevate the expression of a particular gene in dividing human cells and in cancer cells, challenging conventional wisdom. Only a few nucleotides in length, microRNAs, or miRNAs for short, don’t encode proteins. Instead, they largely downregulate, or suppress, protein production by silencing the expression of certain genes. One class of cellular machinery regulated by miRNAs are the enzymes involved in mediating glycosylation, which add carbohydrates to certain proteins. In cancer cells, however, this process can be highly dysregulated, suggesting that miRNAs could be doing something unusual. So, Lara Mahal and colleagues set out to investigate exactly how miRNAs function within the glycosylation process, and whether the molecules might be functioning in a new way. Previously, the researchers developed a fluorescence assay that can analyze how miRNAs interact with their targets, and whether they increase or decrease the amount of protein produced. They used the assay to investigate the regulation of cancer-related glycosylation enzymes ST6GAL1 and ST6GAL2, and found that for the former, the miRNAs appeared to directly upregulate the process in noncancerous human cells. This challenges the current understanding that miRNAs only downregulate protein production. They also tested for miRNAmediated upregulation in multiple cancer microRNA molecules, as shown in this illustration, can upregulate proteins in addition cell lines to downregulating them. and obCredit: nobeastsofierce/Shutterstock.com served the same results. The researchers say that this work expands the understanding of how miRNAs work, an important consideration for using miRNAbased therapeutics in both current and future clinical trials. The authors acknowledge funding from the Canada Excellence Research Chair Program.

From the ACS Press Room

Putting the brakes on lithium-ion batteries to prevent fires

“Early Braking of Overwarmed LithiumIon Batteries by Shape-Memorized Current Collectors”

Nano Letters

Lithium-ion (Li-ion) batteries are used to power everything from smart watches to electric vehicles, thanks to the large amounts of energy they can store in small spaces. When overheated, however, they’re prone to catching fire or even exploding. But recent research published in ACS’ Nano Letters offers a possible solution with a new technology that can swiftly put the brakes on a Liion battery, shutting New technology could help prevent fires in it down when it overheating lithium ones shown here. -ion batteries, like the gets too Credit: cigdem/Shutterstock.com hot. The chemistry found in many batteries is essentially the same: Electrons are shuttled through an electronic device in a circuit from one electrode in the battery to another. But in a Li-ion cell, the electrolyte liquid that separates these electrodes can evaporate when it overheats, causing a short circuit. In certain cases, short circuiting can lead to thermal runaway, a process in which a cell heats itself uncontrollably. When multiple Li-ion cells are chained together — such as in electric vehicles — thermal runaway can spread from one unit to the next, resulting in a very large, hard-to-fight fire. To prevent this, some batteries now have fail-safe features, such as external vents, temperature sensors or flameretardant electrolytes. But these measures often either kick in too late or harm performance. So, Yapei Wang, Kai Liu and colleagues wanted to create a Li-ion battery that could shut itself down quickly, but also work just as well as existing technologies. The researchers used a thermally-responsive shape memory polymer covered with a conductive copper spray to create a material that would transmit electrons most of the time, but switch to being an insulator when heated excessively. At around 197 F, a microscopic, 3D pattern programmed into the polymer appeared, breaking apart the copper layer and stopping the flow of electrons. This permanently shut down the cell but prevented a potential fire. At this temperature, however, traditional cells kept running, putting them at risk of thermal runaway if they became hot again. Under regular operating temperatures, the battery with the new polymer maintained a high conductivity, low resistivity and similar cycling lifetime to a traditional battery cell. The researchers say that this technology

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