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Category: chemistry – Page 277

All plant cells obtain their energy mainly from two organelles they contain—chloroplasts (responsible for photosynthesis) and mitochondria (responsible for the biochemical cycle of respiration that converts sugars into energy). However, a large number of a plant cell’s genes in its mitochondria and chloroplasts can develop defects, jeopardizing their function. Nevertheless, plant cells evolved an amazing tool called the RNA editosome (a large protein complex) to repair these kinds of errors. It can modify defective messenger RNA that result from defective DNA by transforming (deamination) of certain mRNA nucleotides.

Automatic error correction in plant cells

Automatic error correction in plants was discovered about 30 years ago by a team headed by plant physiologist Axel Brennicke and two other groups simultaneously. This mechanism converts certain cytidine nucleotides in the messenger RNA into uridine in order to correct errors in the chloroplast DNA or mitochondrial DNA. RNA editing is therefore essential to processes such as photosynthesis and cellular respiration in plants. Years later, further studies showed that a group of proteins referred to as PPR proteins with DYW domains play a central role in plant RNA editing. These PPR proteins with DYW domains are transcribed in the and migrate through the cells to chloroplasts and mitochondria. However, they are inactive on their way to these organelles. Only once they are within the organelles do they become active and execute their function at a specific mRNA site. How this activation works, however, has been a mystery until now.

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Most cases of Parkinson’s disease are considered idiopathic – they lack a clear cause. Yet researchers increasingly believe that one factor is environmental exposure to trichloroethylene (TCE), a chemical compound used in industrial degreasing, dry-cleaning and household products such as some shoe polishes and carpet cleaners.

To date, the clearest evidence around the risk of TCE to human health is derived from workers who are exposed to the chemical in the work-place. A 2008 peer-reviewed study in the Annals of Neurology, for example, found that TCE is “a risk factor for parkinsonism.” And a 2011 study echoed those results, finding “a six-fold increase in the risk of developing Parkinson’s in individuals exposed in the workplace to trichloroethylene (TCE).”

Dr Samuel Goldman of The Parkinson’s Institute in Sunnyvale, California, who co-led the study, which appeared in the Annals of Neurology journal, wrote: “Our study confirms that common environmental contaminants may increase the risk of developing Parkinson’s, which has considerable public health implications.” It was off the back of studies like these that the US Department of Labor issued a guidance on TCE, saying: “The Board recommends […] exposures to carbon disulfide (CS2) and trichloroethylene (TCE) be presumed to cause, contribute, or aggravate Parkinsonism.”

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Light-driven molecular motors have been around for over 20 years. These motors typically take microseconds to nanoseconds for one revolution. Thomas Jansen, associate professor of physics at the University of Groningen, and Master’s student Atreya Majumdar have now designed an even faster molecular motor. The new design is driven by light only and can make a full turn in picoseconds using the power of a single photon. Jansen says, “We have developed a new out-of-the-box design for a motor molecule that is much faster.” The design was published in The Journal of Physical Chemistry Letters on 7 June.

The new design started with a project in which Jansen wanted to understand the energy landscape of excited chromophores. “These chromophores can attract or repel each other. I wondered if we could use this to make them do something,” explains Jansen. He gave the project to Atreya Majumdar, then a first-year student in the Top Master’s degree program in Nanoscience in Groningen. Majumdar simulated the interaction between two chromophores that were connected to form a .

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As the number of qubits in early quantum computers increases, their creators are opening up access via the cloud. IBM has its IBM Q network, for instance, while Microsoft has integrated quantum devices into its Azure cloud-computing platform. By combining these platforms with quantum-inspired optimisation algorithms and variable quantum algorithms, researchers could start to see some early benefits of quantum computing in the fields of chemistry and biology within the next few years. In time, Google’s Sergio Boixo hopes that quantum computers will be able to tackle some of the existential crises facing our planet. “Climate change is an energy problem – energy is a physical, chemical process,” he says.

“Maybe if we build the tools that allow the simulations to be done, we can construct a new industrial revolution that will hopefully be a more efficient use of energy.” But eventually, the area where quantum computers might have the biggest impact is in quantum physics itself.

The Large Hadron Collider, the world’s largest particle accelerator, collects about 300 gigabytes of data a second as it smashes protons together to try and unlock the fundamental secrets of the universe. To analyse it requires huge amounts of computing power – right now it’s split across 170 data centres in 42 countries. Some scientists at CERN – the European Organisation for Nuclear Research – hope quantum computers could help speed up the analysis of data by enabling them to run more accurate simulations before conducting real-world tests. They’re starting to develop algorithms and models that will help them harness the power of quantum computers when the devices get good enough to help.

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The population on Earth is increasingly growing and people are expected to live longer in the future. Thus, better and more reliable therapies to treat human diseases such as Alzheimer’s and cardiovascular diseases are crucial. To cope with the challenge of ensuring healthy aging, a group of international scientists investigated the potential of biosynthesising several polyamines and polyamines analogs with already known functionalities in treating and preventing age-related diseases.

One of the most interesting molecules to study was spermidine, which is a natural product already present in people’s blood and an inducer of autophagy that is an essential cellular process for clearing damaged proteins, e.g., misfolded proteins in brain cells that can cause Alzheimer’s. When people get older the level of spermidine in the blood decrease and dietary supplements, or certain are needed to maintain a stable and high level of spermidine in the blood. However, those products are difficult to produce with traditional chemistry due to their structural complexity and extraction of natural resources is neither a commercially viable nor a sustainable approach.

Therefore, the researchers instead decided to open their biochemical toolbox and use classical metabolic engineering strategies to engineer the yeast metabolism to produce polyamines and polyamines analogs.

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Possibly one of the most surprising ways in which our mind and body are interlinked with one another is the gut-brain axis, which is a collection of bidirectional biochemical signals which are transmitted between the nervous system of the body and the digestive system. This is understandably surprising, as the functions of these two distinct parts of the body are completely different to one another. The gut is unlike most other parts of the body, because a large part of its function and health is dictated by cells which are not part of the body, but are instead bacteria cells which colonise the inner lining of the gut.

It has been known for a while now that the makeup of the gut flora changes as we age, which has in turn been linked to cognitive decline through the disruption of the aforementioned gut-brain axis. It has even been shown that faecal transplants can help to correct this cognitive decline in mice, and has been shown to be able to generate a direct positive effect on cognitive function.

Further research into this phenomenon has revealed that the graduate degradation of the gut flora, or more commonly referred to as the ‘good’ bacteria inside the gut has revealed that these bacteria play an important role at keeping unwanted bacteria in check. Researchers at the University Of Florida have found that certain types of ‘good’ bacteria inside the gut produce a chemical known as butyrate, which supresses the growth of pathogenic bacteria such as Enterobacteriaceae. These pathogenic, or ‘bad’ bacteria effect the body in numerous ways, such as interfering with the protein folding, resulting in a build up of toxic and mis-formed proteins within the body. This disruption to protein folding causes problems all across the body, including in the muscles, intestines, gonads, and most notably the brain and central nervous system.

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The World Health Organization classifies processed meat as a Group 1 carcinogen. Processed meat includes ham, sausage, bacon, pepperoni; they’re meats that have been preserved with salt or smoke, meat that has been cured, and meat treated with chemical preserves. Other Group 1 carcinogens include formaldehyde, tobacco, and UV radiation. Group 1 carcinogens have ‘enough evidence to conclude that it can cause cancer in humans.’

There is no question whether or not our current meat production complex is inhumane, unsanitary, or bad for the environment. Almost all chickens (99.9%), turkeys (99.8%), and most cows (70.4%) eaten in the United States are raised on factory farms. There are horrific consequences to this practice.

For example, the EPA estimates agriculture is the biggest contaminator of rivers and streams, to the point where feedlots, crop production, and manure runoff have led almost half (46%) of the U.S.’s rivers to be “in poor biological condition.”

Scientific American also explains, “TDM-approved feed containing antibiotics [are] a necessity if [factory farm animals] were to stay healthy in their crowded, manure-gilded home. Antibiotics also help farm animals grow faster on less food, so their use has long been a staple of industrial farming.” Many scientists worry that antibiotics used at such a scale on farms create unstoppable, drug-resistant bacteria that can transfer to humans; think inconveniences like nose infections or UTIs turned deadly because of the lack of antibiotics available to treat them.

Continue reading “Vegans Diets and Longevity: What Existing Science Actually Says” | >

The way the team made the human–monkey embryo is similar to previous attempts at half-human chimeras.

Here’s how it goes. They used de-programmed, or “reverted,” human stem cells, called induced pluripotent stem cells (iPSCs). These cells often start from skin cells, and are chemically treated to revert to the stem cell stage, gaining back the superpower to grow into almost any type of cell: heart, lung, brain…you get the idea. The next step is preparing the monkey component, a fertilized and healthy monkey egg that develops for six days in a Petri dish. By this point, the embryo is ready for implantation into the uterus, which kicks off the whole development process.

This is where the chimera jab comes in. Using a tiny needle, the team injected each embryo with 25 human cells, and babied them for another day. “Until recently the experiment would have ended there,” wrote Drs. Hank Greely and Nita Farahany, two prominent bioethicists who wrote an accompanying expert take, but were not involved in the study.

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Circa 2019

As quantum computing enters the industrial sphere, questions about how to manufacture qubits at scale are becoming more pressing. Here, Fernando Gonzalez-Zalba, Tsung-Yeh Yang and Alessandro Rossi explain why decades of engineering may give silicon the edge.

In the past two decades, quantum computing has evolved from a speculative playground into an experimental race. The drive to build real machines that exploit the laws of quantum mechanics, and to use such machines to solve certain problems much faster than is possible with traditional computers, will have a major impact in several fields. These include speeding up drug discovery by efficiently simulating chemical reactions; better uses of “big data” thanks to faster searches in unstructured databases; and improved weather and financial-market forecasts via smart optimization protocols.

We are still in the early stages of building these quantum information processors. Recently, a team at Google has reportedly demonstrated a quantum machine that outperforms classical supercomputers, although this so-called “quantum supremacy” is expected to be too limited for useful applications. However, this is an important milestone in the field, testament to the fact that progress has become substantial and fast paced. The prospect of significant commercial revenues has now attracted the attention of large computing corporations. By channelling their resources into collaborations with academic groups, these firms aim to push research forward at a faster pace than either sector could accomplish alone.

Continue reading “Manufacturing silicon qubits at scale” | >