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Scientists harness bottled ‘lightning’ to generate essential ingredients for life

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Nitrogen is an essential element for life and is an integral part of DNA and proteins. Most of the nitrogen on Earth exists in the atmosphere as gaseous nitrogen, denoted as N.2 However, most organisms cannot directly use nitrogen. In modern ecosystems, some microorganisms have specialized enzymes that convert nitrogen into nitrogen.2 It converts gases into a form that other living things can use. Fixed nitrogen These microorganisms Nitrogen fixing bacteria.

But 3 to 4 billion years ago, during a period in Earth's history called the Archean Era, life had not yet evolved and no nitrogen-fixing organisms existed, so scientists studying the origin of life are faced with a classic chicken-and-egg problem: life needed nitrogen to evolve, but before life evolved, there were no microorganisms to convert nitrogen into nitrogen.2 Let's turn gas into something we can use! So where did life get its nitrogen from before there were nitrogen-fixing organisms?

Researchers recently hypothesized that early life on Earth may have obtained fixed nitrogen from lightning. They propose that the high energy of a lightning spark could react with oxygen and N.2 Fixing atmospheric nitrogen2 The gas is converted into other usable forms of nitrogen. Nitrogen oxides.

Geologists have studied the sedimentary rock record to understand nitrogen throughout Earth's history, but they had no way to distinguish lightning-derived nitrogen in rocks from other ancient sources of nitrogen. To explore whether lightning provided fixed nitrogen to early life, researchers led by Dr. Patrick Barth created “lightning” in a jar and tested whether it would react with nitrogen.2 It emitted gases and produced nitrogen oxides that had an identifiable signal.

To simulate lightning, the researchers used electrodes in glass flasks filled with different gas mixtures: To mimic modern-day Earth, Barth and his colleagues used a flask with a composition similar to our current atmosphere, containing 85 percent nitrogen.2 They also used flasks containing an atmosphere similar to that of Archean Earth, which scientists believe was about 83% nitrogen.20% oxygen, 16% carbon dioxide.

The researchers added 50 milliliters (about a quarter cup) of water to the bottom of each flask to allow any nitrogen oxides and other compounds produced during the reaction to dissolve in the water. They discharged each experimental flask to about 50 kilovolts for 15 to 60 minutes — nearly 10 times the voltage of an electric car battery.

The research team developed a device called Quadrupole Gas AnalyzerThey measured the nitrogen compounds in the gases coming out of each flask before and after they were ignited. They found that in the modern experiment, more fixed nitrogen was dissolved in the water than in the gas. But in the Archean experiment, the fixed nitrogen was split almost equally between the water and the gas.

After each reaction, the researchers placed the flask of water into an apparatus that measured the weight of the nitrogen atoms. Gas Source Mass SpectrometerThey explained that nitrogen atoms exist in two main forms with different masses, called isotopes. 14The N isotope is lighter and more abundant in nature, 15The N isotope is heavier and less common. The researchers used mass spectrometer data to calculate the ratios of nitrogen isotopes in the lightning-fixed nitrogen samples. They compared these nitrogen isotope ratios to those in rocks that are 3.1 to 3.8 billion years old to see if there was a match.

The researchers found that the nitrogen isotope ratio of the lightning-produced nitrogen was about 0.1% to 1% lighter than that of the rocks, and suggested that this difference in nitrogen isotopes indicates that most of the nitrogen in the Archean rocks was not produced by lightning.

The researchers also used the lightning flash rate on modern Earth to predict the amount of nitrogen oxides that lightning would produce per year. They estimated that the annual lightning flash rate alone could not have provided enough nitrogen to support ecosystems on early Earth. They explain that there was even less lightning in the Archean than there is today, so even less nitrogen was available to support early life.

The researchers concluded that lightning was not the main source of available nitrogen for early life. Because nitrogen-fixing organisms must have evolved very early in Earth's history, life did not need to rely solely on lightning, they suggested. However, one of the 3.7-billion-year-old rock samples showed nitrogen isotope ratios similar to lightning-fixed nitrogen, leading the researchers to speculate that small amounts of fixed nitrogen from lightning may have supported early life. Furthermore, the researchers suggested that the lightning-fixed nitrogen isotope ratios obtained in this study could be used to investigate how nitrogen is fixed on other planets in the solar system.


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Source: sciworthy.com

Researchers find approximately 250,000 undetected nanoplastic particles in each liter of bottled water

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The average bottle of water contains nearly 250,000 tiny, invisible particles of nanoplastic that were detected and classified for the first time using a dual-laser microscope.

Scientists have long suspected that there are a lot of these tiny pieces of plastic, but until researchers at Columbia University and Rutgers University made calculations, they had no idea how many or what types they were. Researchers examined five samples of each of three common bottled water brands and found particle levels ranging from 110,000 to 400,000 per liter, with an average of about 240,000, according to Monday’s findings.
Proceedings of the National Academy of Sciences.

These are particles less than 1 micron in size. One inch is 25,400 microns (also called a micrometer because it is one millionth of a meter).
The width of a human hair is approximately 83 microns.

Previous research looked at slightly larger microplastics, ranging from visible 5 millimeters (less than a quarter of an inch) to 1 micron. The study found that about 10 to 100 times more nanoplastics than microplastics were found in bottled water.

Nisin Kian, the study’s lead author and a physical chemist from Colombia, said much of the plastic appears to come from the bottles themselves and the reverse osmosis filters used to keep out other contaminants. She did not reveal her three brands because the researchers need more samples and would like to study more brands before singling out one. Still, she said they were common and she bought them at Walmart.

Researchers still can’t answer the big question: Are these nanoplastic pieces harmful to health?

“That’s under consideration right now. We don’t know if it’s dangerous or how dangerous it is,” said study co-author Phoebe Stapleton, a toxicologist at Rutgers University. “We know they invade tissues (of mammals, including humans)…and current research is investigating what they do inside cells.”

The International Bottled Water Association said in a statement: “Currently, there is a lack of standardized (measurement) methods and no scientific consensus on the potential health effects of nano- and microplastic particles. Reports will only unnecessarily scare consumers.”

The American Chemistry Council, which represents plastics manufacturers, had no immediate comment.

The world is “driving under the weight of plastic pollution, with more than 430 million tonnes of plastic produced annually” and microplastics are being found all over the planet.
world ocean,
food and
drinking water
Some of it comes from clothing and cigarette filters, according to
United Nations Environment Programme. Initiatives towards
global plastic treaty It will continue even after negotiations stalled in November.

All four co-authors interviewed said they had reduced their use of bottled water after conducting the study.

Wei Ming, a Colombian physical chemist who pioneered dual-laser microscopy technology, said he has cut his use of bottled water in half. Stapleton said he is now using more filtered water at his home in New Jersey.

But Bayzan Yan, a co-author of the study and a Colombian environmental chemist who has increased tap water usage, said the introduction of plastic could cause problems with the filters themselves.

“There’s no chance of winning,” Stapleton said.

Naixin Qian, a physical chemist at Columbia University, zooms in on an image of microscopic pieces of plastic that appeared as bright red dots in New York on Monday.
Mary Conlon/Associated Press

Outside experts who praised the study agreed there were general concerns about the dangers of plastic particles, but it was too early to say for sure.

“The dangers of plastic itself are an unanswered question. To me, the additives are the most concerning,” said Jason Somarelli, professor and director of the Comparative Oncology Group at Duke University School of Medicine. . He did not participate in this study. “We and other researchers have shown that these nanoplastics can be taken up into cells, and that nanoplastics have the potential to cause cellular stress and DNA damage, altering metabolism and cell function. We know that it contains all kinds of chemical additives that are harmful.”

Somarelli said his unpublished research found more than 100 “known carcinogenic chemicals in these plastics.”

Zoe Diana, an evolutionary biologist at the University of Toronto, said: “The concern is that small particles are showing up in various organs and can cross membranes that they’re not supposed to cross, such as the blood-brain barrier.'' ” he said.

Diana, who was not involved in the study, said this was an exciting development in the study of plastics in the environment and in the body, thanks to the new tools researchers used.

About 15 years ago, Min invented a dual-laser microscopy technique that identifies specific compounds by their chemical properties and how they resonate when exposed to a laser. Yang and Qian approached him about using the technology to find and identify plastics that are too small for researchers using established methods.

“This study could be an important advance in the detection of nanoplastics,” said Kara Lavender-Law, an oceanographer at the Marine Education Association, adding that other analytical chemists will not be able to replicate the technique and results. He said he would like to see it done.

Dennis Hardesty, an Australian government oceanographer who studies plastic waste, said context was needed. The total weight of the nanoplastics found is “approximately the weight of one penny, which is the volume of two Olympic-sized swimming pools.”

Mr. Hardesty is less concerned about nanoplastics in bottled water than others, saying, “I am privileged to live in an area with access to ‘clean’ tap water, and I don’t have access to drinking water in single-use containers. There’s no need to buy one.”

Yang said other municipalities, including Boston, St. Louis and Los Angeles, are starting to look at how much plastic is in their tap water.
Previous research We’re looking for microplastics, and some early tests show tap water may have less nanoplastics than bottled water.

Despite the unknowns about human health, Yang said he has one recommendation for those concerned. It’s about using reusable bottles instead of single-use plastics.

Source: www.nbcnews.com