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Comment by Dr. Krishna Kumari Challa on January 12, 2024 at 11:44am

Biomaterials contribute greatly to reduction of greenhouse gas emis...

On average, bio-based products emit 45% less greenhouse gas emissions than the fossil materials they replace, according to research conducted by Radboud University, published in Nature Communications. At the same time, there is a large variation between individual bio-based products and more efforts are required to achieve climate neutrality. Additionally, biomaterials may have less favorable environmental impacts in other areas.

On average, bio-based products emit 45% less greenhouse gas emissions than the fossil materials they replace, according to research conducted by  scientists, published in Nature Communications. At the same time, there is a large variation between individual bio-based products and more efforts are required to achieve climate neutrality. Additionally, biomaterials may have less favourable environmental impacts in other areas.

Globally, there is a lot of investment in developing new materials from biomass, commonly known as biomaterials, to mitigate CO₂ emissions from fossil materials. Biomaterials are derived from plants and are intended to replace materials made from fossil fuels, such as bio-plastics or bio-fibers (for clothing). It is assumed that biomaterials are better in terms of environmental impact.

Research shows that, on average, new biomaterials emit 45% less CO2 than their counterparts made from fossil fuels. The researchers analyzed data from 98 new biomaterials reported in 130 international studies. "These studies considered the entire chain: from raw material extraction, production itself, to the final waste processing.

Part 1

Comment by Dr. Krishna Kumari Challa on January 12, 2024 at 11:33am

Green and red cone cells are remarkably similar except for a protein called opsin, which detects light and tells the brain what colours people see. Different opsins determine whether a cone will become a green or a red sensor, though the genes of each sensor remain 96% identical. With a breakthrough technique that spotted those subtle genetic differences in the organoids, the researchers tracked cone ratio changes over 200 days.

The researchers also mapped the widely varying ratios of these cells in the retinas of 700 adults. Seeing how the green and red cone proportions changed in humans was one of the most surprising findings of the new research.

Retinoic acid signaling regulates spatiotemporal specification of human green and red cones, PLoS Biology (2024). DOI: 10.1371/journal.pbio.3002464. journals.plos.org/plosbiology/ … journal.pbio.3002464

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Scientists still don't fully understand how the ratio of green and red cones can vary so greatly without affecting someone's vision.

To build understanding of diseases like macular degeneration, which causes loss of light-sensing cells near the center of the retina, the researchers are working with other Johns Hopkins labs. The goal is to deepen their understanding of how cones and other cells link to the nervous system.

Part 2

Comment by Dr. Krishna Kumari Challa on January 12, 2024 at 11:30am

Lab-grown retinas explain why people see colours some animals can't

With human retinas grown in a petri dish, researchers discovered how an offshoot of vitamin A generates the specialized cells that enable people to see millions of colors, an ability that dogs, cats, and other mammals do not possess.

These retinal organoids allowed scientists for the first time to study this very human-specific trait. It's a huge question about what makes us human, what makes us different.

The findings, published in PLOS Biology, increase understanding of color blindness, age-related vision loss, and other diseases linked to photoreceptor cells. They also demonstrate how genes instruct the human retina to make specific color-sensing cells, a process scientists thought was controlled by thyroid hormones. By tweaking the cellular properties of the organoids, the research team found that a molecule called retinoic acid determines whether a cone will specialize in sensing red or green light. Only humans with normal vision and closely related primates develop the red sensor.

Scientists for decades thought red cones formed through a coin toss mechanism where the cells haphazardly commit to sensing green or red wavelengths—and research from researchers recently hinted that the process could be controlled by thyroid hormone levels. Instead, the new research suggests red cones materialize through a specific sequence of events orchestrated by retinoic acid within the eye.

The team found that high levels of retinoic acid in early development of the organoids correlated with higher ratios of green cones. Similarly, low levels of the acid changed the retina's genetic instructions and generated red cones later in development.

There still might be some randomness to it, but the big finding is that you make retinoic acid early in development.This timing really matters for learning and understanding how these cone cells are made.

Part1

Comment by Dr. Krishna Kumari Challa on January 12, 2024 at 10:06am

Copy and taste

There is still much that needs to be understood about the interplay of obvious enjoyment and the liking of food. For example, the researchers have focused on adults, and while this has not been tested for on this occasion, they said that given the power of negative facial expressions and because children tend to be less willing to try vegetables by default, these findings could generalize to kids.

"For example, if a child sees their parent showing disgust while eating vegetables, this could have negative consequences on children's vegetable acceptance.

In the present study, participants also watched short video clips rather than watching people eat in front of them. This allowed them to observe the dynamic nature of reactive facial expressions, which is more realistic than looking at static pictures; however, in the future, an important focus will be to examine the effect of watching live food enjoyment on eating behavior, the researchers said.

"We also need more research to see whether the findings from this study translate to adults' actual intake of vegetables.

Katie L. Edwards et al, Facial expressions and vegetable liking, Frontiers in Psychology (2024). DOI: 10.3389/fpsyg.2023.1252369

Part 2

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Comment by Dr. Krishna Kumari Challa on January 12, 2024 at 10:04am

Watching others visibly dislike vegetables might make onlookers dislike them, too

Humans learn which behaviours pay off and which don't from watching others. Based on this, we may draw conclusions about how to act—or eat. In the latter's case, people may use each other as guides to determine what and how much to eat. This is called social modeling and is one of the most powerful social influences on eating behaviour.

In a new study, researchers  investigated whether observing others' facial expressions while eating raw broccoli influenced young women's liking and desire to eat raw broccoli.

They show that watching others eating a raw vegetable with a negative facial expression reduces adult women's liking of that vegetable, but not their desire to eat it. This highlights the power of observing food dislike on adults' eating behaviour. 

Previous research shows that behaviors are more likely to be imitated if positive consequences are observed, while the reverse is true if negative outcomes are witnessed. In the present study, however, this correlation was observed only partially: Exposure to models eating broccoli while conveying negative facial expressions resulted in a greater reduction in liking ratings, whereas the reverse did not hold. Watching others eating a raw vegetable with a positive facial expression did not increase adults' vegetable liking or eating desire.

One possible explanation may be that avoiding any food—irrespective of whether it is commonly liked or disliked—that appears disgusting can protect us from eating something that tastes bad or is harmful. Another reason may be that smiling while eating is perceived as an untypical display of liking a certain food.

"This might imply that watching someone eating a raw vegetable with positive facial expressions does not seem an effective strategy for increasing adults' vegetable consumption.

Part 1

Comment by Dr. Krishna Kumari Challa on January 12, 2024 at 9:57am

In a new paper, scientists describe a new peptide that binds directly to MYC with what is called sub-micro-molar affinity, which is getting closer to the strength of an antibody. In other words, it is a very strong and specific interaction.

Researchers now improved the binding performance of this peptide over previous versions by two orders of magnitude. This makes it closer to their drug development goals.

Currently, the researchers are using lipid nanoparticles to deliver the peptide into cells. These are small spheres made of fatty molecules, and they are not ideal for use as a drug. Going forward, the researchers are developing chemistry that improves the lead peptide's ability to get inside cells.

Once the peptide is in the cell, it will bind to MYC, changing MYC's physical properties and preventing it from performing transcription activities.

MYC represents chaos, basically, because it lacks structure. That, and its direct impact on so many types of cancer make it one of the holy grails of cancer drug development.

Zhonghan Li et al, MYC-Targeting Inhibitors Generated from a Stereodiversified Bicyclic Peptide Library, Journal of the American Chemical Society (2024). DOI: 10.1021/jacs.3c09615

Part 2

Comment by Dr. Krishna Kumari Challa on January 12, 2024 at 9:55am

Scientists tame chaotic protein fueling 75% of cancers

MYC is the shapeless protein responsible for making the majority of human cancer cases worse. Researchers have now found a way to rein it in, offering hope for a new era of treatments.

In healthy cells, MYC helps guide the process of transcription, in which genetic information is converted from DNA into RNA and, eventually, into proteins. Normally, MYC's activity is strictly controlled. In cancer cells, it becomes hyper active, and is not regulated properly.

MYC is less like food for cancer cells and more like a steroid that promotes cancer's rapid growth. That is why MYC is a culprit in 75% of all human cancer cases.

In 2018, the researchers noticed that changing the rigidity and shape of a peptide improves its ability to interact with structureless protein targets such as MYC.

Peptides can assume a variety of forms, shapes, and positions. Once you bend and connect them to form rings, they cannot adopt other possible forms, so they then have a low level of randomness. This helps with the binding.

Part 1

Comment by Dr. Krishna Kumari Challa on January 11, 2024 at 12:32pm

Is Vitamin D that importnat?
For a time, vitamin D was touted as a potential miracle vitamin, thought to prevent everything from heart disease to cancer to diabetes. But several recent randomized controlled trials showed no significant benefit of vitamin D for any major condition. To be sure, vitamin D plays a vital role in health, but most people get all they need in several minutes of daily sunlight.

Why this matters: Overtesting by doctors of vitamin D serum levels remains widespread. Experts disagree about how to interpret the test and many doctors still unnecessarily recommend vitamin D supplements. The supplements represent more than a $1 billion market, despite the lack of evidence that they are necessary for the majority of people (not to mention the fact that vitamins are not independently tested for purity or dosing).

What the experts say: “There’s a religiosity around vitamin D,” says Clifford Rosen, an endocrinologist at the Maine Medicine Center's Research Institute. “The evidence is out there. People don’t want to pay attention to it.”

 no significant benefit of vitamin D

Comment by Dr. Krishna Kumari Challa on January 11, 2024 at 11:58am

Higher viral load during HIV infection can shape viral evolution

A new paper in Molecular Biology and Evolution finds that HIV populations in people with higher viral loads also have higher rates of viral recombination. In effect, the more HIV in the blood, the easier it is for the virus to diversify.

One of the reasons HIV has historically been so difficult to combat is the virus's exceptionally high rate of recombination. Recombination enables the exchange of genetic information across strains of the virus and drives HIV's evolution within people. This genetic exchange helps the virus evade the immune system and become resistant to many drugs designed to treat HIV.

More generally, recombination is an important evolutionary driver, permitting organisms to purge destructive mutations and combine beneficial ones.

Understanding the factors that impact recombination rate in a well-studied system such as HIV can help uncover some of the effects that recombination has on evolution more broadly.

One important yet understudied step in HIV recombination is coinfection, in which two different virus particles infect the same cell.

The researchers involved with the new study hypothesized that people with higher viral loads (more HIV in the blood) would have more cells that were coinfected, which would lead to higher rates of recombination for the virus. To investigate this hypothesis, they developed a new approach called Recombination Analysis via Time Series Linkage Decay (RATS-LD) to quantify recombination using genetic associations between mutations over time.

This investigation found that while HIV populations with viral loads in the lowest third of the data set have recombination rates in line with previous estimates, while populations with viral loads in the upper third have a median recombination rate that is nearly six-fold higher. Furthermore, the researchers observe patterns of viral load and effective recombination rate increasing simultaneously within single individuals.

 Elena Romero et al, Elevated HIV viral load is associated with higher recombination rate in vivo, Molecular Biology and Evolution (2023). DOI: 10.1093/molbev/msad260. academic.oup.com/mbe/article-l … .1093/molbev/msad260

Comment by Dr. Krishna Kumari Challa on January 11, 2024 at 11:17am

More than 900 chemicals, many found in consumer products and the environment, display breast-cancer causing traits

With tens of thousands of synthetic chemicals on the market, and new ones in development all the time, knowing which ones might be harmful is a challenge both for the federal agencies that regulate them and the companies that use them in products. Now scientists have found a quick way to predict whether a chemical is likely to cause breast cancer based on whether the chemical harbors specific traits.

This new study provides a roadmap for regulators and manufacturers to quickly flag chemicals that could contribute to breast cancer in order to prevent their use in consumer products and find safer alternatives.

The study titled "Application of the Key Characteristics framework to identify potential breast carcinogens using publicly available in vivo, in vitro, and in silico data," published in Environmental Health Perspectives.

The researchers identified a total of 921 chemicals that could promote the development of breast cancer. Ninety percent of the chemicals are ones to which people are commonly exposed in consumer products, food and drink, pesticides, medications, and workplaces.

A breakdown of the list revealed 278 chemicals that cause mammary tumors in animals. More than half of the chemicals cause cells to make more estrogen or progesterone, and about a third activate the estrogen receptor.

Breast cancer is a hormonal disease, so the fact that so many chemicals can alter estrogen and progesterone is concerning.

Since damage to DNA can also trigger cancer, the researchers searched additional databases and found that 420 of the chemicals on their list both damage DNA and alter hormones, which could make them riskier. What's more, the team's analysis found that chemicals that cause mammary tumors in animals are more likely to have these DNA-damaging and hormone-disrupting characteristics than ones that don't.

These findings show that screening chemicals for these hormonal traits could be an effective strategy for flagging potential breast carcinogens.

Application of the Key Characteristics framework to identify potential breast carcinogens using publicly available in vivo, in vitro, and in silico data, Environmental Health Perspectives (2024). DOI: 10.1289/EHP13233. ehp.niehs.nih.gov/ehp13233

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