Revolutionary CRISPR-based genome editing system treatment destroys cancer cells

 

How far has humanity advanced medical studies and treatments in the past couple of centuries? Since Edward Jenner noticed that milkmaids exposed to cowpox did not get smallpox, more than two centuries passed and smallpox was transformed from civilization- ender to nuisance. Today the more looming problem is cancer.  Around 17.0 million people worldwide in 2018 died from cancer. In November of 2020 a group of researchers from Tel Aviv University published the results of their study where the researchers used novel CRISPR technology to treat two of the most aggressive cancers. The system called CRISPR-LNPs carried messenger RNA which encodes for the Cas9 enzyme which cuts DNA in cells. The research conducted by Daniel Rosenblum, Anna Gutkin, Zvi Cohen, Mark Behlke and Judy Lieberman had the result that mice glioblastoma, a brain cancer with a 15-month life expectancy and a 3% 5-year survival rate, doubled their average life expectancy and increased survival rate to 30% after single treatment. Results from ovarian cancer, the most lethal cancer of female reproductive system, showed that the overall survival rate was increased by 80%. This was achieved because the CRISPR-LNP system was able to identify and cut genes essential for the cancer cells to replicate. As it is known in biology the pathway is from RNA to DNA to proteins and CRISPR manipulate RNA to create DNA that will code for enzyme Cas9 which cuts the target DNA. But the biggest problem is the delivery system for the treatment. The LNP (lipid nanoparticle) system solves the problem of delivery so this discovery opens a whole new field of treatments for genetic diseases such as Sickle Cell Anemia which might be advantageous in areas where medicine is undeveloped but is detrimental in developed countries.

"Plastics are showing up in the world’s most remote places, including Mount Everest" and "How much plastic floats in the Great Pacific Garbage Patch?"

 Posted by Harrison Smith

Plastics are finding a way into the most extreme and isolated landscapes that Planet Earth has to offer. Plastics, or rather microplastics, have been found in the snow of Mount Everest. Majority of the plastics were found to be polyester fibers, likely originating from clothes of human hikers. Supporting this claim, it was found that snow from the base camp had a high concentration of plastic particles. The base camp is a common place for hikers to congregate, so it is reasonable that there is a high concentration of microplastics in this area shedding from their clothes. Nonetheless, plastic was found as high as 8,440 meters above sea level, only 400 meters from the summit of the tallest peak on the planet.

Plastic has also been found in some of the deepest depths of the sea, in the Mariana Trench. Plastics were found as deep as 10,890 meters below sea level, far below the penetrable reach of sunlight. The worst part? These plastics were found inside of animals. In one 2019 study, 90 crustaceans deep in the Pacific were analyzed for plastic contaminants. Of these 90 crustaceans, 65 were found to have microplastics inside of them. It is obvious that human waste is reaching the furthest corners and most hidden nooks and crannies of our planet.

Apart from the Mariana Trench and Mount Everest, plastics have been found in places far from any usual human activity. Plastics have been found in alarming amounts at an isolated meteorological station in the Pyrenees Mountains. Specifically, 365 microplastic particles per day rain down on each square meter at the station. That is as much as some cities! These particles are estimated to travel 95 km due to wind propulsion before landing at the remote meteorological station in the Pyrenees Mountains. This 95 km distance is based on simulations that consider wind speed and direction.

Now I know what some of you may be thinking. 365 particles per square meter in a remote location? How is that possible? Well we are not talking about Tupperware or water bottles here. We are talking about microplastics. Microplastics, as defined by this article, are any

plastic pieces smaller than 5 millimeters in length. Some may be invisible to the human eye, and others may be fibers reaching the length of a half centimeter. Below is an image provided to give an idea of the size of particles that were in discussion throughout the duration of the article.

A microplastic, as shown on the right, compared in size to one of the previously discussed crustaceans, as shown on the left. This comparison is provided to give a general guideline of the size of the plastics discussed in this article and blog post. Use the key provided at the top of pictures for size comparisons.

The microplastics in discussion are definitely small, but are they small enough to be labeled as negligible or harmless? The answer is no. Microplastics can block the gills of certain crustaceans, like crabs, and negatively impact ecosystems. Other animals around the globe are also susceptible to harm from these microplastics.

To be fair, larger animals will likely bypass complications caused by these microplastics. Believe it or not, humans consume a surprising amount of microplastics. One study estimates that humans consume between 39,000 and 52,000 microplastics annually. This study came about these numbers based on analyzing common food and drinks for their composition of microplastics. These numbers are surprisingly large, considering that we likely are never aware of the plastic we are consuming; if that were the case, we would just spit out our food before swallowing. Based on this, it is reasonable to assume that microplastics do not impact larger animals, such as sea turtles or big game fish. Whereas this might be true for the individual, it is not true for the ecosystems that host these animals. If their ecosystems cannot withstand the microplastic pollution, the animals themselves may be at risk.

However, there are direct, pollution-related risks to the species that may be immune to harm from microplastics. This is because microplastics are a form of pollution, but it does not act alone. All of the plastic waste around the world is not under 5 millimeters in length. A lot of waste is bigger and more prominent than the small fibers previously talked about in this blog post. The truth is there is all kinds of human waste found in our previously pristine environment. This is due to the increase in human plastic use over the past century. In the 1950’s the global plastic usage landed around 5 million tons per year. In 2020, the annual plastic usage has jumped to 330 million tons per year. The heavy usage of plastic has resulted in vast amounts of pollution.

One major example is the Great Pacific Garbage Patch, also referred to as Trash Island. The Great Pacific Garbage Patch is comprised of two massive piles of trash floating in the Northern Pacific. Whereas much of the debris is made of larger pieces of plastic, majority of it is actually comprised of degraded plastics that have turned into microplastics. These microplastics account for about 94% of the object counts of the patches. In terms of mass, however, objects larger than .5 centimeters account for 92% of the total mass. The patches are massive; scientists have estimated that the size of the patches is equivalent to twice the area of Texas. The problem here is that much of the plastic floats below the surface, and the patches are constantly moving and morphing into different shapes. These factors make it hard for scientists to estimate the size and density of the patches. These numbers are important to accurately determine, as they can lead engineers to develop more efficient ways to clean up the garbage and help restore a healthy ecosystem.

A portion of the Great Pacific Garbage Patch floats in the ocean.

Perry the Platypus’s Signature Color Isn’t Total Fantasy

 

Figure 1: Perry the Platypus, a Disney character from the show Phineas and Ferb

Recent articles from National Geographic and Science News have brought to light an interesting discovery. It was found that the fur of platypuses exhibited biofluorescence. This was not expected from researchers because very few other mammals, such as a few species of flying squirrel and a few marsupials such as opossums, are known to be fluorescent. Fluorescence works when the fur absorbs a photon at one wavelength and emits a photon at another wavelength with common emitted colors being red, green, orange, and blue. When the platypus pelt was illuminated by ultraviolet (UV) light the pelt emitted a blue-green glow similar to the color of Perry the Platypus. However, due to the UV light saturating everything with a purple hue, a yellow filter was used to produce a more “true” color to what the eye sees.

Figure 2: This picture shows what platypuses look like when illuminated with normal visible light and UV light with and without the yellow filter, and the UV reflectance.

The purpose of the biofluorescence is still unknown to researchers. Platypuses are already one of the strangest creatures alive on several counts. Not only are they one of only two mammals that lay eggs, but they also have poisonous spines on their rear legs and have the ability to sense electrical signals in water to aid in catching prey. There are several theories about why platypus fur fluoresces ranging from camouflage to a simple vestigial trait. The basis of the camouflage theory is that common predators of platypuses such as birds of prey, dingoes, crocodiles, and Murray Cod can see in the UV, and since the platypus absorbs UV light it gains camouflage. On the other hand, it could have no real function and just be an ancestral trait that was retained and has no practical use anymore. This is plausible because fluorescent fur has beenfound in all 3 major branches of mammals: monotremes (platypuses), marsupials (opossums), and placental mammals (flying squirrel). While there are still more theories such as aiding in intraspecies communication, only one real correlation that has been found, the dark. All the known cases of mammals being fluorescent occur in mammals that are active at night or in the low light time such as dusk or dawn. Since there is less known about the nocturnal world, there is a high probability that there are lots of other mammals that exhibit biofluorescence. As research continues more information on the actual cause and reason for the biofluorescence will come to light.
 

Extra Chemical Speculation:​ It is known that the species of fly squirrels fluoresce pink and platypuses fluoresce blue-green. Therefore, the chemical source of the biofluorescence is most likely different for each animal. None of the articles specified any compounds responsible for the biofluorescence, but typical organic compounds that fluoresce strongly are aromatic and/or heterocyclic compounds. It is likely that the source of biofluorescence in mammals is an unknown aromatic and/or heterocyclic compound.

Sources:

● https://www.nationalgeographic.com/animals/2020/11/glowing-platypus/#close
● https://www.sciencenews.org/article/platypus-glow-blue-green-ultraviolet-light-fluorescent-fur 

 

New Cloth Face Masks can be Disinfected by the Sun!

 Posted by Julia Munoz

In the current era of COVID-19, many people have turned to cloth face coverings. While this is good, viruses and bacteria that are stuck to the mask can be transferred off the mask when the mask is taken off. An article from ScienceDaily, discusses how ACS Applied Materials and Interfaces has developed a new cotton mask that kills 99.9999% of bacteria and viruses after only 60 minutes of daylight exposure.

Credit: Adapted from ACS Applied Materials and Interfaces 2020,

DOI:10.1021/acsami.Oc15540

Most face masks, which are made of various cloth materials, filter out nanoscale aerosol particles. These are usually released when someone coughs or sneezes. Wearing masks prevents these particles from being spread between peoples because it blocks their transmission. However, the bacteria and virus on the mask still remain contagious.  Peixin Tang, Gang Sun, Nitin Nitin and colleagues have been working on a new cotton fabric that would be able to release reactive oxygen when it was exposed to daylight, thus killing microbes attached to the cloth, while still being washable, reusable, and safe to wear.

ACS Appl. Mater. Interfaces 2020, 12, 44, 49442–49451

Publication Date:October 22, 2020 https://doi.org/10.1021/acsami.0c15540 

The group made their antimicrobial masks by attaching positively charged chains of 2-diethylaminoethyl chloride to regular cotton. Next, they dyed the modified cotton in a solution of negatively charged photosensitizer. This attaches to the DEAE chains by strong electrostatic interactions. Testing showed that the mask could be handwashed at least 10 times and constantly exposed to daylight for 7 days before losing its antimicrobial defense. 

Safer Lithium Metal Batteries

Posted by Garrett Moran

A recent article from ScienceDaily illustrates a group of engineers from Columbia University School of Engineering discovering a way to make the common lithium metal batteries not only safer, but also more efficient and longer lasting. There are countless stories of lithium batteries catching on fire and exploding. This is due to the formation of microstructures that contain non-conductive compounds on the surface of lithium metal during the battery use or recharge cycle. These undesirable microstructures stop the lithium ion transport process and cause dangerous short-circuiting within the battery which results in the battery overheating and either catching on fire or exploding.

Hazards of Li Batteries

The group of engineers discovered that the addition of alkali metals, such as potassium ions to a conventional lithium battery electrolyte, prevents lithium microstructure proliferation during the batteries use. The group achieved this by using a combination of techniques to examine the lithium metal while the additives were introduced. These techniques include microscopy, nuclear magnetic resonance and computational modeling. The article notes that when the metal was being examined while the additives were being introduced, “unique chemistry” was observed at the lithium/electrolyte interface. This unique chemistry was not specified, but the teams PI says that this addition of potassium salt to the lithium electrolyte mitigates the formation of these undesirable, non-conductive microstructures. The article also notes that this discovery differs in technique from traditional electrolyte manipulation approaches where depositing conductive polymers on the lithium metal surface was the primary focus. This discovery is one of the first to characterize the surface chemistry of lithium metal using NMR and is considered a breakthrough for new techniques using NMR and future designs of electrolytes for lithium metal.

CRISPR Cuts the Scientific Community in Two

Posted by Cole McElmurray

Much ado has been made about CRISPR, the enzyme complex that can edit and remove DNA from cells. Most recently, a team of scientists in 2017 led by Dr. Shoukhrat Mitalipov at Oregon Health and Science University published results where they used CRISPR to remove a gene that caused heart disease in human embryos. Mitalipov found that the enzyme complex did not use the sample DNA that the scientists had provided to repair the break in the DNA, but instead copied and used the healthy gene that was found elsewhere in the cell. Proponents of CRISPR say that the gene editing technology can be used to remove genetic mutations in human fetuses that would otherwise put them at risk for genetic disease and conditions, but others take the view that CRISPR is more trouble than it’s worth, as Megan Molteni reports for Wired.

Figure 1. The method by which CRISPR cuts and edits DNA. 

Opposition to Mitalipov’s findings was swift. Dr. Dieter Egli from Columbia University conducted research of his own on CRISPR. After three years, he has found evidence that seems to contradict Mitalipov’s research. Egli’s team injected CRISPR into sperm cells that were positive for a gene that causes blindness. After the sperm was used to fertilize eggs, the chromosomes of the embryos were looked at. It was found that the offending genes had been removed, but nothing had been put in their place. Large sections of missing DNA can cause major and adverse health effects to humans, such as disease, cancer, or death of the embryo, even more so than the mutated genes that CRISPR can remove.

Gene editing in human embryos also brings up major ethical concerns. Egli and his team were forced to find outside funding for their experiments because the US Congress will not fund experiments on viable human embryos, and the United States and 75 other countries ban any experiments that involve establishing a pregnancy with a genetically-modified embryo or fetus. The World Health Organization has recommended an immediate stop to experiments that would result in births of genetically modified humans. He Jiankui, the controversial figure who claims to have performed CRISPR experiments on embryos that were carried to term in China, was found guilty of a breach of medical ethics in late 2019 and sentenced to 3 years in prison.

This article is not exactly positive about science and chemistry, and seems to try to paint a picture of “mad science”. It’s meant to show the reader that sometimes scientists can go too far in their pursuit of research and progress. The article uses fear tactics by focusing on genetically modified fetuses and negative health effects that can occur from CRISPR, as well as bringing up the lurid story of He Jiankui. The article is remarkably light on actual chemistry facts. It does not even bring up that CRISPR is an enzyme complex, leading some readers to make the conclusion that it is some sort of machine or tool. While it makes mention of CRISPR “cutting” DNA, it does not mention the mechanism by which it does so. The article deliberately keeps the chemistry light in order to not bore a lay reader and to focus on the ethics of CRISPR instead of the science. 

 

Black and Blue all over: Scientists Discover a Method to Make Concrete Bruise Like a Bumped Knee.

Posted by Tim Martin 

Recently a research team from the Structural Composite Research Center at the Institute of Advanced Composite Materials, which is part of the Korean Institute of Science and Technology, has improved the mechano-sensitivity of spiropyran. spiropyran reacts to an external force that converts it into merocyanine, which appears blue in light. Before the recent development spiropyran was not sensitive enough for real life applications, for instance when injected into concrete or silicone the deformation of the parent material must be drastic for the spiropyran to visibly convert to merocyanine . However, a more sensitive polymer will not only allow for safer building materials but also the use of spiropyran in wearable sensors for artificial skin, a leap forward for the medical field. The research group enhanced spiropyran’s sensitivity to stimuli by first synthesizing a composite material and then applying a solvent mixture of spiropyran, which “ages” the molecule and makes it more fragile to force. The formed polymer showed up to a 850% improvement as compared to polymers produced through other,more traditional methods. The solvent approach also allows for the application of spiropyran by manipulating the solvent mixture based on the target material. The polymer is so sensitive it can now react to tension compression and bending, exceeding its prior applications in building materials.
 

 

Periodic Table and New Elements

 Posted by Qianhui Hua

Every field of science has its favorite anniversary.  For chemistry, there is no reason tobe celebrated beyond the origin of the periodic table. The periodic table of the elements was created 150 years ago by the Russian chemist Dmitrii Ivanovich Mendeleev.

Chemistry students have become more and more familiar with the periodic table. It enumerates the elements that make up all the earth's materials and arranges them to reveal the laws of their properties, thereby guiding the development of chemical research in theory and practice. But the periodic table of elements is not immutable. In 2016, four new elements officially became full members. I searched and understood how the periodic table gets new elements. 

Each element on the periodic table has a different number of protons. Therefore, chemists look for two known elements that they can crush together to create new elements. So far, the element with the highest atomic number discovered by humans is element 118.

To make oganesson, element 118, chemists used 20 protons of Ca and 98 protons of Cf.  A beam of ions of one element is shot at atoms of the other element. With luck, the two fuse, forming the new element. But often they don’t. And even when they do, the new element are often unstable. They can decay in mere milliseconds.

I am also very interested in its naming. These names were determined by the International Union of Pure and Applied Chemistry (IUPAC). Anyway, the IUPAC says that elements have to be named after one of five things: a scientist, a place, a mineral or substance, a descriptor of the element, or a mythological reference. Of the new elements, three are named after places and one is named after a person.
For these 4 new elements, nihonium (element 113), the name is based on the Japanese word Nippon, which is one word for Japan itself—where the element was discovered—and means “Land of the Rising Sun”. Moscovium (115), named after Moscow. Tennessine (117), named after Tennessee. Researchers at Vanderbilt University and University of Tennessee teamed up to discover this one in 2010, making it the most recently synthesized element. It’s also just the second element to be named after a U.S. state, the first being californium. Oganesson(118) is named after Yuri Oganessian, a Russian nuclear physicist.

https://www.sciencenews.org/article/physics-periodic-table-future-superheavy-elements 

https://www.sciencenews.org/article/physics-chemistry-how-periodic-table-gets-new-elements
 

Glowing Plants

Posted by Emma Crouch

The chemistry world has recently been talking about the glowing Venus flytrap and why it has made breakthroughs. Scientists have recently found that by splicing a special gene into the carnivorous plant, researchers can visualize the mechanism and chemistry that helps them snap shut on prey. When provoking a Venus flytrap, the first stimulus is often ignored, and action is not seen until the second. For years, scientists have struggled with why this phenomenon only occurs on the second stimulus. However, they have now found that it is due to Calcium ions. The plant uses the calcium to convey information and makes it easy for the cell to recognize change in concentration. To observe this in the lab, scientists used a gene that when bound to calcium, produces a fluorescent green. This gene was integrated with a modified bacterium. Once implemented, researchers were able to visualize the difference of total calcium ions between the first stimulus and the stimulus that eventually made the Venus flytrap close. With this new and exciting information researchers will be able to understand even more about the electrical activity of many plants.

Glow Seen From First Stimulus 

Glow Seen From Second Stimulus 

 

 

There’s Water and Ice on the Moon, and in More Places Than NASA Thought

 Posted by Anna Evers

An article in the NYT has reported that NASA has found unambiguous evidence of water on the moon where the sun shines. A team of scientists used SOFIA, an infrared telescope mounted inside a 747- jumbo jet, to discover that water might be distributed across the lunar surface and not limited to the cold shadowed places near the lunar poles. The water was detected via six-micron waves, that water molecules characteristically emit. This may mean that astronauts going to the moon in the future will not only have access to water, but also possibly oxygen, since water molecules can be broken into their constituent hydrogen and oxygen atoms. The oxygen would give the astronauts something to breathe. Hydrogen and oxygen can also be used as rocket propellant for trips home to Earth or even some day to Mars and beyond.

The article also mentions that observations by a spacecraft a decade ago had also suggested a widespread distribution of water on the moon. Those measurements focused on a shorter, three-micron wavelength that was more ambiguous, unable to differentiate between a water molecule, which consists of two hydrogen atoms and one oxygen atom or hydroxyl, which has one hydrogen atom and one oxygen atom. Finding hydroxyl molecules on the moon instead of water would be very disappointing for astronauts.

It can also be dangerous for astronauts to try and extract the water, as it is often found in deep, very cold craters. This water finding was unique because it found water molecules in shallower, warmer craters. Scientists are not yet sure how the molecules can exist here, but they do. The water molecules detected are also not puddles of water but spread far enough apart that they cannot form ice or liquid water. In 2022, NASA is planning to send an IR rover to the moon, and hopefully confirm this new evidence. 

                                                      

         

Hydroxyl vs water molecules 

Climate Surgery: A Revolution in Medicine?

 Posted by Jordan Berry

Recently, as reported in the Newy York Times novel neurosurgery was performed that gave new life without seizures, epilepsy, and chronic anorexia. The patient? Cronutt, a 7-year old sea lion.

Figure 1: A picture of Cronutt after surgery

 

Figure 2: The two pastries for which Cronutt is named after, the croissant and the donut

Climate change has had many deleterious effects for environments and for people, but many do not consider the effect on aquatic life. Climate change has lead to the prominence and proliferation of algal blooms, algae that uncontrollably grow and distribute domoic acid to shellfish that sea lions, like Cronutt, eat to survive. This poison, is for one, a neurotoxin that have recently caused a new form of climate change induced epilepsy called amnesic shellfish poisoning (ASP) in animals like sea lions, sea otters, and humans.

Figure 3: Domoic Acid

Unfortunately, due to the novelty of this disease, there currently is no treatments available. According to the Washington State Department of Health, for humans they are typically put on life support until either the toxin passes through their system or they die. For sea lions without a complex medical system like humans, they tend to suffer terrible deaths by drowning while having a seizure underwater. Typical epileptic treatments like Valium, steroids, and phenobarbital fail, so a new treatment was devised where three neurosurgeons from USCF replaced hippocampal neurons in Cronutt’s brain using embryonic pig brain cells. This surgery, according to the neurosurgeons and his veterinarian caretakers, seems to have been successful at first glance. Only time will tell if this success sticks.

                                                (a)                                                        (b)

(c)

Figure 4: The typical seizure medications(a)Diazepam (Valium), (b)Prednisone (typically labeled steroids), and (c)Phenobarbital

This article, although not chemophobic, gives negative connotations to chemistry. It does not present chemists as aloof or indiscriminate to their waste, but it does present those who use their inventions in this way. It presents the chemical medical treatments given the Cronutt as insufficient and the chemical that is produced as a toxin a direct byproduct of human activity. This article only prevents chemophobia by mentioning the specific names of the chemicals as to prevent a generalization of all industrial chemicals as a cause of this. It does not perpetuate or challenge the stereotypes of chemists since this story is not about chemists but the chemicals themselves. It does argue that there needs to be more attention placed on our oceans, but does not mention any specific actions chemists can take to alleviate these issues. As the story concludes, one of the veterinarians mention, “Even if it doesn’t work, and there’s a chance it won’t work, maybe Cronutt’s purpose is to educate that there are toxins in our water and our ocean needs our attention.”

How Does Your Garden Glow?

Posted by Sondra Broomell

Venus Flytraps are one of the very plant species that are carnivorous and exhibit movement. It is thought that this evolutionary adaptation came about in response to life in areas with little nutrition. When triggered, the plant snaps shut, digests, and absorbs nutrients from their visiting prey. However, the response is a bit complex, for a plant. For the “mouth” lobes to shut, the prey must brush, push, or somehow agitate trigger hairs located on the lobes twice, in quick succession (within 30 seconds). This double trip adaptation is believed to keep the plant from wasting energy by snapping shut on something that causes only a momentary disturbance, such as a raindrop or wind. Scientists have been studying the Venus flytrap for some time in hope of discovering the evolution of movement and carnivory in plants as well as discovering how the plant remembers how many times its sensory hair was triggered without a nervous system. In 1988 a group of scientists conducted a study utilizing freeze-fracture studies and microelectrode measurements to determine the action potential of the Venus Flytrap movement. Through a series of experiments, the researchers measured action potentials generated by several different ions. They suspected that two overlapping spikes in intracellular calcium ions were required for the plant to snap shut. Calcium ions are known to convey information between cells but without the technology to measure extracellular and intracellular calcium concentration, their findings were limited. But for the first time Japanese researchers were able to visualize, through fluorescence, the calcium ions required for the Venus Flytrap to shut. A recent article on The New York Times website summarizes the study published in Nature Plants. With gene splicing technology, the researchers introduced a fluorescent protein gene to the Venus Flytrap by infecting the leaves with a modified bacteria which were then used to grow new plants containing the fluorescent gene. This protein, GCaMP6, only fluoresces when bound to its target, calcium ions, enabling visualization of calcium ion movement into the cell. Once the plants matured, all that was left was to trigger the sensory hairs of the Flytraps and watch them glow. After a single disturbance of the trigger hair, the fluorescence began at the base of the trigger hair and spread across the leaves. After a second disturbance of the trigger hair within 30 seconds, a second surge of intracellular calcium ions caused the lobes glow brighter, and the concentration reached the threshold to trigger an action potential that caused the plant to snap shut. When the second trip happened after 30 seconds, enough calcium ions diffused out of the cell to prevent the concentration from reaching the threshold for movement. Visualizing ionic movement through a plant by means of fluorescence is sure to be spectacular, but also puts up a step closer to understanding the mechanism behind plant movement.

Figures from PhysOrg

https://www.nytimes.com/2020/10/12/science/venus-flytraps-close.html

https://www.nature.com/articles/s41477-020-00773-1

https://link.springer.com/article/10.1007/BF00394867

https://phys.org/news/2020-10-probe-memory-venus-flytrap.html

 

What tiny surfing robots teach us about surface tension

 Posted by Harrison Smith

It’s pumpkin season. The air is crisp. Leaves are falling, along with the temperature. Some may call it sweater weather; some may call it spooky season. But if you are anything like my friends, we just use it as an excuse to hit the winery. That is, those who are 21, of course. If you have ever been to a winery, I am sure you have seen a wide assortment of characters. You have your middle-aged reunions and your first dates. You have your young crowd, probably going just to drink and maybe crash a wedding (I’m definitely not speaking from experience). They don’t really know much about wine. On the contrary, you can be sure to find your wine connoisseurs, or the taste experts. You know who I’m talking about: those who taste test from nine different bottles and twirl the wine in the glass before taking a miniscule sip. We have all seen the classic wine twirl in movies, but what is it that these experts are actually looking for?

They’re looking for wine legs, or tears. Check out the picture below for a better idea!

Pretty neat right!? Who knew wine could walk? Well, that isn’t exactly what’s going on here. What we are actually looking at is the Marangoni Effect. The schematic below did a great job explaining the science behind this phenomenon.

The biggest concept here is the difference in surface tension throughout the wine. If you think of the wine as two components, the alcohol vs. the other stuff, it’s intuitive that they will have different chemical properties. Specifically, the alcohol has a lower surface tension compared to the other components. So, when the wine connoisseur spins the wine, thus thinning increasing surface area and the rate of evaporation towards the top of the glass, the liquid at the top is composed of less wine. This causes a subtle increase in surface tension towards the top of the wine. The increase in surface tension pulls mass in that direction. This net force, propelling particles from low surface tension to high surface tension, is known as the Marangoni Effect.

Dr. Hassan Masoud, at the Michigan Technological University is a Mechanical Engineer who has plenty of experience with the Marangoni Effect. A recent Science Daily article, “What tiny surfing robots teach us about surface tension,” speaks on Masoud’s work at Michigan Tech. He has been using tiny robots, just microns in size, to study liquid interfaces. Apparently, a lot of work has been published with microscopic swimming robots, but Dr. Masoud has more of a niche area of research with his surfing robots.

Recently, he made an interesting discovery. His surfing robots, with no engine or propeller mechanism, were propelled in a direction opposite of the Marangoni Effect. As previously discussed, the Marangoni Effect describes the transfer of mass and momentum in the direction of higher surface tension. Masoud’s surfing robots actually moved in the direction of lower surface area. He coined this term “reverse Marangoni propulsion.”

It was determined through further research that negative pressure suction from the low surface area was the primary propulsive force. However, by experimenting with different liquid thickness and chemical releases, Masoud and his coworkers found that particles can react in agreement with Marangoni, against Marangoni, and come to a complete stand still. Masoud noted that science has just begun to scratch the surface of understanding particle movement at the liquid interface.

Once a more concrete understanding is had, scientists can begin to learn how to control the movement of these particles. This could potentially be used in in a physiological setting to gain a better understanding of how bacteria colonize. Infection has plagued humans since we have been on Earth, and it is still a surprisingly common occurrence post-surgery. Many surgeries, particularly joint replacements requiring metal implants, result in bacteria-caused infection. If we can use Masoud’s research to gain a better understand and potentially control bacterial swarming, it would be a massive step forward in a biomedical context.

With that being said, I feel obligated to do my part to help society. I’m going to go grab a bottle and study up... in the name of science!

Why adding salt makes fruit - and candy - sweeter

 Posted by Ayaz Yelemessov

A recent article in Science magazine talks about how ironically if you treat eating something salty before eating something sweet the sweetness will be enhanced.  Originally the ability to taste sweetness was attributed to a family of receptors called T1R which recognize the glucose and artificial sweeteners. However, this hypothesis was disproved in 2003 when mice whose T1R were genetically disabled were still able to sense sweetness. Attempting to explain such a phenomenon, physiologists of Tokyo Dental Junior College looked at the enzyme called sodium- glucose cotransporter 1 (SGCT1).  Tongues of T1R disabled mice were rubbed with a solution of salt and glucose or just glucose, then responses were recorded. Results showed that mice whose tongues were rubbed with salt-glucose solution had a more rapid response.  Sadly, this experiment worked only with glucose due to enzymes specificity. The hypothesis was proven when SGCT1 inhibiting compounds prevented response to glucose in mice. Article also explored that sweet sensing is tied to three ways, one for each receptor and third for combined receptors. First two pathways allow bodies to distinguish between artificial and natural sweeteners. The combined pathway was also responsive to fatty acids and umami which might suggest how animals sense calorie- rich foods.

This ties to concepts of galvanic chemistry and nerve electric impulses explored in Frankenstein.  In galvanic chemistry charged species move and through movement are able to generate small amounts of electricity. This allows for complex nervous systems to function by manipulating chemical gradients of sodium and potassium to create small electric impulses.  This concept was utilized in Frankenstein’s endeavors where Victor used large amounts of electricity to reanimate dead flesh. Similarly, sodium ion charges stimulate the nerve cells in mice enhancing the sensation of sweetness in mice that should not sense. This shows how electricity can create movement of muscles and thoughts in the brain by supplying extra electrons and creating ion movement. 

New Enzyme Breaks Down Plastic Faster Than Ever Before!

 Posted by Julia Munoz

British and American researchers have developed new enzymes that speed up the breakdown of plastic. This new method is faster, more affordable, and works better on a large scale than current methods. The New York Times article claims that the new “super enzyme” has the ability to break down plastic much more quickly and can create raw materials to make new bottles, while making the material easier to repurpose.

Prof. John McGeehan in Britain in 2018.

Worldwide, there are 359 million tons of plastic produced annually. Of the 359 million tons, at least 150 million tons of this plastic is sitting in landfills or in the environment somewhere. While sitting in the ocean, plastic can take up to 450 years to degrade, if it does at all. The plastic that does break down in the ocean can be found in marine life, ocean water, and even the guts of humans.

The journal PNAS, was published by scientists at the University of Portsmouth, and the National Renewable Energy Laboratory, focuses on a mixture of two enzymes found in bacterium in Japan in 2016. In 2018, while studying the first enzymes ability to break down plastic, the researchers added the second enzyme and found that the plastics were broken down six times as fast.

This article is chemistry related because the enzyme can only effectively break down the plastic based on their chemical composition. While this article is not linked to much controversy, the article is about a major problem that the world today is facing. I think that this would be a good

article to show a CHEM 100 class because while it is not too difficult in terms of chemistry terms and concepts, it does show a very current and pressing issue in our environment today and how chemistry can be used to work towards solving the problem.

Mysterious Poison in Russian Coast Water

Posted by Nathaniel Renner

Recent news articles from CBS News and The Washington Post reported that in the recent weeks’ surfers and locals of the far eastern peninsula of Kamchatka, Russia have been reporting discolored water, a mass die-off of ocean wildlife, and a “poison-like” effect after exposure to the water. The symptoms of the “poison-like” effect have been described as “White shroud, blurred vision, dryness. Sore throat,” by some surfers, as well as many surfers reporting “nausea, weakness, [and a] high fever”. Originally the local government officials claimed there were no problems releasing a statement saying “The color of the water is normal, the smell of the air is normal, the beach is completely clean. . . . Nothing anomalous was recorded.” However, after much outcry from the continuing mass die-off, the local acting Minister of Natural Resources and Ecology, Aleksei Kumarkov, reported that upon analyzing a sample of water levels of petroleum products were revealed to be at four-times what they should be, and levels of the toxic compound Phenol at over two-times the normal levels.

Figure 1: Structure of Phenol

Figure 2: Map showing the location of Kamchatka, Russia 

Phenol is an aromatic organic compound that is composed of a phenyl group bonded to a hydroxy group. Phenol is mildly acidic and can cause chemical burns to the skin in high concentrations. Phenol and its vapors are corrosive to the eyes, the skin, and the respiratory tract. It can also be absorbed through the skin relatively quickly and even with only a small area of skin, meaning oral consumption is not necessary. Contact with Phenol may cause harmful effects to the central nervous system (CNS) and heart leading to dysrhythmia, seizures, and coma. Repeated exposure to phenol can be harmful to the liver, kidneys, reproductive organs and could be possibly fatal as the LD50 has been reported at around 140 mg/kg or a total dose of 1-32g for humans. The toxic and corrosive effects are due to a protein-degenerating effect as well as the formation of phenoxyl radicals. When comparing the side effects of Phenol poisoning and the reported side effects of the surfers who have been exposed to the water, there appears to be a match. The surfers reported blurred vision, sore throats, and weakness which match well to Phenol’s effect on the eyes, respiratory tracts, and CNS. Phenol is also toxic to fish and other sea life at levels of 0.05 mg/L which would explain the mass die-off being seen.

Figure 3: Ariel Footage showing discoloration in the water surrounding Kamchatka

Figure 4: Deceased Sea life from mass die-off on the shores of Kamchatka 

While the source of the petroleum products and the toxic Phenol is currently unknown the Russia Government has begun to take the situation more seriously and there are some preliminary theories of what the source could be. The regional government has started an investigation into the cause and the governor of Kamchatka, Vladimir Solodov, said more samples of the water had been sent to Moscow for analysis, and he promised to fire anyone who is found to have deliberately tried to cover up or embellish the crisis at it initial surfacing. Some locals have theorized that the source is from military training exercises but Russia defense ministry has denied this claim. As of now the prevailing theory from Russia’s Tass news agency reports that a commercial oil tanker was likely the source. This is very plausible as phenol is a common waste product of petroleum refining.

Sources:

• ●  https://www.cbsnews.com/news/kamchatka-russia-disaster-pollution-animal-die-off-oil-

  found-pacific-killing-sea-life/

• ●  https://www.washingtonpost.com/world/europe/russia-kamchatka-oil-spill-

  octopus/2020/10/04/812c1c92-0570-11eb-b92e-029676f9ebec_story.html

• ●  http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.302.3133&rep=rep1&type=pdf

• ●  https://en.wikipedia.org/wiki/Phenol#Toxicity