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Comment by Dr. Krishna Kumari Challa on March 16, 2024 at 10:02am

More than 16,000 chemicals can be found in plastic, and many are harmful: Report

Researchers have found more than 16,000 chemicals in plastics. A new report shows that about a quarter of these chemicals can be hazardous to health and the environment.

Plastic pollution is an international environmental crisis, and the researchers behind a new report are becoming increasingly concerned about the health consequences of plastic. There are many problematic chemicals in plastics. They pose a threat to both human health and the environment. Therefore, we must make plastic safe and sustainable.

We can only deal with the plastic problem if we take the chemicals in the plastic into account, and manage them in a responsible manner.

The United Nations is in the process of negotiating a global treaty on plastics. The goal is to end plastic pollution and develop plastics that are safer and more sustainable. That makes it very important for decision makers to know as much as possible about the chemicals in plastics, and take them into account when making decisions.

The key findings of the new report:

• At least 4,200 plastic chemicals, approximately 26%, pose a health and/or environmental hazard.
• 400 of the chemicals that are of concern to the researchers are found in all types of plastics, including plastic food packaging. All plastics can leach hazardous chemicals.
• To make plastic materials safer, we need new methods to regulate the chemicals. This includes identifying the hazardous chemicals and regulating hazardous groups of plastic chemicals.

In addition to being a database of problematic substances, the document also provides a method for identifying and managing chemicals of concern in plastics.

Part 1

Comment by Dr. Krishna Kumari Challa on March 16, 2024 at 9:30am

We can simply change the amount of water vapour in the system to regenerate the entire material in this new process. In this way, we can minimize the energy we put into the process.

The researchers examined ways to control and modify the materials at the nano-scale to enable more efficient moisture-swing carbon capture. They found that loading the pores with highly basic, negatively charged ions such as phosphate and carbonate yielded the highest capacity for carbon capture.

Yaguang Zhu et al, Confinement Effects on Moisture-Swing Direct Air Capture, Environmental Science & Technology Letters (2024). DOI: 10.1021/acs.estlett.3c00712

Part 2

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Comment by Dr. Krishna Kumari Challa on March 16, 2024 at 9:28am

Researchers use moisture to pull carbon dioxide out of the air

A way to capture and release carbon dioxide from the atmosphere is by simply changing the surrounding humidity using a material.

The material could slash the energy costs associated with so-called direct air capture systems, which conventionally rely on energy-intensive temperature or pressure shifts to switch between carbon capture and release. By instead relying on humidity, the material could yield energy efficiency improvements over five times above current technologies. The researchers  report their findings in Environmental Science & Technology Letters.

Direct air capture systems have been heralded as a way to combat climate change by pulling carbon dioxide out of the air to either store permanently underground or convert into a useful product.

Despite its promise, direct air capture has come under scrutiny since it requires more energy to perform than almost any other application of carbon capture. That is because the concentration of carbon dioxide in ambient air is extremely diluted, especially when compared to the waste gas from a point-source emitter such as a coal-fired power plant. One of the process' most energy-intensive steps is regeneration. After capturing carbon dioxide from ambient air, conventional systems require heat and/or pressure changes to release the gas into storage so that the system can be prepared to capture more carbon. In one approach using a liquid solvent, the regeneration step requires heating the carbon capture material to temperatures ranging from 300° to 900°C. By contrast, previous research has shown that regenerating carbon capture materials with humidity only requires adding or removing water vapor. Such an approach dramatically cuts the energy required to remove a ton of carbon dioxide, from up to 4.1 gigajoules using conventional techniques to just 0.7 gigajoules—an energy savings per ton.

To achieve the humidity-based approach, the Princeton team modified an existing type of ion-exchange resin, a material that can trade charged particles with the surrounding environment. These resins are already used for a range of commercial purposes, making them widely available and inexpensive.
Moreover, the surfaces of these resins are dotted with countless tiny pores, only 6 nanometers in diameter. The carbon capture process takes place inside these cavities. At low humidity, a series of chemical reactions occurs in the pores that allows them to capture carbon dioxide from a stream of incoming air. At high humidity, the opposite occurs: the material releases its bound carbon and is prepared for another round of capture.

Part 1

Comment by Dr. Krishna Kumari Challa on March 16, 2024 at 7:31am

New research suggests that our universe has no dark matter

The current theoretical model for the composition of the universe is that it's made of normal matter, dark energy and dark matter. A new study challenges this.

A study, published recently in The Astrophysical Journal, challenges the current model of the universe by showing that, in fact, it has no room for dark matter.

In cosmology, the term "dark matter" describes all that appears not to interact with light or the electromagnetic field, or that can only be explained through gravitational force. We can't see it, nor do we know what it's made of, but it helps us understand how galaxies, planets and stars behave.

Physicists used a combination of the covarying coupling constants (CCC) and "tired light" (TL) theories (the CCC+TL model) to reach this conclusion.

This model combines two ideas—about how the forces of nature decrease over cosmic time and about light losing energy when it travels a long distance. It's been tested and has been shown to match up with several observations, such as about how galaxies are spread out and how light from the early universe has evolved.

This discovery challenges the prevailing understanding of the universe, which suggests that roughly 27% of it is composed of dark matter and less than 5% of ordinary matter, remaining being the dark energy.

Challenging the need for dark matter in the universe

The study's findings confirm the researchers' previous work (1) ("JWST early universe observations and ΛCDM cosmology") about the age of the universe being 26.7 billion years has allowed them to discover that the universe does not require dark matter to exist.

In standard cosmology, the accelerated expansion of the universe is said to be caused by dark energy but is in fact due to the weakening forces of nature as it expands, not due to dark energy.

"Redshifts" refer to when light is shifted toward the red part of the spectrum. The researcher analyzed data from recent papers on the distribution of galaxies at low redshifts and the angular size of the sound horizon in the literature at high redshift.

There are several papers that question the existence of dark matter, but this is the first one that eliminates its cosmological existence while being consistent with key cosmological observations that we have had time to confirm.

By challenging the need for dark matter in the universe and providing evidence for a new cosmological model, this study opens up new avenues for exploring the fundamental properties of the universe.

 Rajendra P. Gupta, Testing CCC+TL Cosmology with Observed Baryon Acoustic Oscillation Features, The Astrophysical Journal (2024). DOI: 10.3847/1538-4357/ad1bc6

Footnotes:

1.  R Gupta, JWST early Universe observations and ΛCDM cosmology, Monthly Notices of the Royal Astronomical Society (2023). DOI: 10.1093/mnras/stad2032

Comment by Dr. Krishna Kumari Challa on March 15, 2024 at 12:45pm

The world needs to hear Paul’s incredible story for a few reasons:
This is what happens if you don't take vaccines
You can never kill a determined mind
How science can make a dying man live
A little help for a deserving human being doesn't make you less rich

The Man in the Iron Lung
Polio Survivor Who Lived in Iron Lung For 7 Decades Dies at 78

Comment by Dr. Krishna Kumari Challa on March 15, 2024 at 11:59am

Can you get electrocuted by an electric vehicle?

Electric cars, scooters and bikes are everywhere. Are they safe? An expert breaks down the safety of EV and lithium-ion batteries when they encounter water.

It is highly unlikely that a Tesla submerged in a pond in  fatal accident poses a threat of electrocution to its driver or rescuers.

Battery compartments in electric vehicles such as Tesla are completely sealed and well protected.

Most electric vehicles, according to the U.S. Department of Energy, like most portable consumer electronics such as smartphones and laptops as well as electric scooters and e-cigarettes are powered by lithium-ion batteries. Lithium-ion batteries store more energy per unit mass and volume and have a high power-to-weight ratio, high energy efficiency, good high-temperature performance, long life and low self-discharge.

An EV battery may get damaged in an accident or punctured by a sharp object. In that case, the electrodes of the opposite charge might touch each other due to damage, which can start a runway reaction.

The battery would start to overheat due to all the electricity being released at once in the uncontrollable process. The temperature of the battery can quickly reach 900°C, or more than 1,650°F and it can catch fire or explode.

When an electric vehicle goes under water the water is unlikely to enter the battery compartment.

There are codes and standards relating to electric vehicles, which particularly deal with a battery pack and how it is protected and sealed.

A vehicle manufactured in the U.S. would fully comply with those requirements. In the case of Tesla vehicles, they are equipped with a number of built-in sensors that can shut the battery off in case of a crash or rollover.

However, the experts are more worried about electric scooters and electric bikes, which also have lithium-ion batteries.They don't have good battery protection from damage, unlike electric  cars.

First responders still have to know that the submerged car is an electric vehicle,  before attempting a rescue. 

If they properly comply with the safety standards, whether it's in an accident or a submergence, [they should be safe].

Source:  Northeastern University

Comment by Dr. Krishna Kumari Challa on March 15, 2024 at 11:49am

Scientists can now remove nanoplastics from your water with 94% efficiency

Researchers have created a new technology that can remove harmful nanoplastics from contaminated water with 94% efficiency. The study, "Utilization of epoxy thermoset waste to produce activated carbon for the remediation of nano-plastic contaminated wastewater," was published in the journal Separation and Purification Technology.

The amount of plastic pollution in our ecosystem has become an increasingly alarming concern globally. Concerns have frequently been flagged about the impact that plastic pollution has on the toxicity to the environment and humans.

The impact of nanoplastics, material that is a thousand times smaller than microplastics, has been found to have a significant detrimental effect on aquatic and human life. However, the options that can eliminate nanoplastics from oceans and lakes are limited.

A team of researchers, who specialize in polymer engineering, tackled a new method to address small plastic waste and remove nanoplastics from wastewater systems.

They used epoxy, a waste polymer that can't be reused or reprocessed and often ends up in landfills or finds its way into water system networks like lakes or streams.

Using a process called thermal decomposition, the researchers converted epoxy into activated carbon, a material capable of removing nanoplastics.

The researchers then used the activated carbon to treat water contaminated by nanoplastics after producing nanoplastics from polyethylene terephthalate, a form of polyester often used in plastic water bottles and clothing such as fleece.

These tiny contaminants pose a greater health risk compared to microplastics as they can penetrate cells and are hard to detect. The 94% removal efficiency of nanoplastics was achieved by physically trapping the nanoplastics in the porous structure of the waste plastic, which generated activated carbon.

Rachel Blanchard et al, Utilization of epoxy thermoset waste to produce activated carbon for the remediation of nano-plastic contaminated wastewater, Separation and Purification Technology (2023). DOI: 10.1016/j.seppur.2023.124755

Comment by Dr. Krishna Kumari Challa on March 15, 2024 at 11:35am

Researchers develop dual anti-tumour vaccine

a research team has discovered that exosomes derived from γδ-T cells not only have direct anti-tumor effects but also, when developed into a tumor vaccine, can effectively induce a tumor-specific immune response. The findings, which provide a new approach to cancer treatment, were published in the Journal of Extracellular Vesicles.

Exosomes are nanoscale particles secreted by cells, carrying various substances, such as lipids, proteins and nucleic acids, that play a crucial role in intercellular communication. Exosomes have been explored for developing tumor vaccines, as they can protect vaccine components from degradation, improve stability, extend the biological half-life, and enhance antigen uptake by antigen-presenting cells (APCs).

Previous studies focused on exosomes derived from tumor cells (TExos) and dendritic cells (DC-Exos) but found limitations in terms of safety and clinical efficacy.

In this study, the research team focused on exosomes derived from human γδ-T cells, a rare subset of T cells known for their direct anti-tumor activity and ability to enhance T-cell responses.

The research team discovered that γδ-T cell-derived exosomes (γδ-T-Exos) exhibited dual anti-tumor activities by carrying cytotoxic and immunostimulatory molecules that can directly kill tumor cells and stimulate the immune system.

They found that γδ-T-Exos has adjuvant effects, enhancing the expression of antigen-presenting and releasing molecules that promote inflammation, which improves the ability of the immune system to recognize and attack tumor cells.

Developing tumor vaccines by loading γδ-T-Exos with tumor-associated antigens proved more effective in promoting tumor-specific T-cell responses than using γδ-T-Exos alone. The vaccine strategy also retained direct anti-tumor effects and induced tumor cell death.

Intriguingly, the research showed that vaccines based on allogeneic γδ-T-Exos (derived from different individuals) exhibited similar preventive and therapeutic effects as vaccines based on autologous γδ-T-Exos (derived from the same individual) in mouse models. This suggests that this approach is suitable for centralized and standardized production. The vaccines have dual anti-tumor capabilities in effectively killing tumor cells and indirectly inducing a T-cell-mediated anti-tumor immune response, leading to better tumor control than existing vaccine strategies.

Xiwei Wang et al, Tumor vaccine based on extracellular vesicles derived from γδ‐T cells exerts dual antitumor activities, Journal of Extracellular Vesicles (2023). DOI: 10.1002/jev2.12360

Comment by Dr. Krishna Kumari Challa on March 15, 2024 at 11:19am

 Researchers observe how energy of single electron is tuned by surrounding atoms

Physicists  have choreographed the shift of a quantized electronic energy level with atomic oscillations faster than a trillionth of a second.

Throwing a ball into the air, one can transfer arbitrary energy to the ball such that it flies higher or lower. One of the oddities of quantum physics is that particles, e.g., electrons, can often only take on quantized energy values—as if the ball was leaping between specific heights, like steps of a ladder, rather than flying continuously.

Qubits and quantum computers as well as light-emitting quantum dots make use of this principle. However, electronic energy levels can be shifted by collisions with other electrons or atoms. Processes in the quantum world usually take place on atomic scales and are also incredibly fast.

Using a novel type of ultrafast microscope, a team of physicists has now succeeded in directly observing with atomic resolution on ultrafast timescales how the energy of a single electron is tuned by the vibrations of the surrounding atoms. Remarkably, they were also able to specifically control this process. Such discoveries could be crucial for the development of super-fast quantum technologies.

The physicists used an atomically thin material to investigate how a discrete energy level changes when this atomic layer moves up and down like the membrane of a drum. They observed this at a vacancy—the void left behind when an individual atom is removed.

Such atomically thin two-dimensional crystals, known for their versatile, customizable electronic properties, are particularly interesting for future nanoelectronics. Vacancies in a crystal are promising candidates for qubits, the elementary information carriers of quantum computers, as they have discrete electronic energy levels just like atoms.

The researchers found that they can change a discrete energy level of the defect by triggering a drum-like vibration of the atomically thin membrane: the atomic motion of the surrounding atoms shifts and thus controls the energy level of the vacancy.

The work establishes a new era in the study of the dynamics of atomically localized energy levels and their interaction with the environment. This discovery enables the local control of discrete energy levels in the most direct way. For instance, the motion of individual atoms could change the energy structure of a material and thus create new functionalities or specifically change the properties of light-emitting semiconductors and molecules.

Carmen Roelcke et al, Ultrafast atomic-scale scanning tunnelling spectroscopy of a single vacancy in a monolayer crystal. Nature Photonics. www.nature.com/articles/s41566-024-01390-6

Comment by Dr. Krishna Kumari Challa on March 15, 2024 at 10:07am

97% of sampled Antarctic seabirds found to have ingested microplastics

Anthropogenic plastic pollution is often experienced through evocative images of marine animals caught in floating debris, yet its reach is far more expansive. The polar regions of the Arctic and Antarctica are increasingly experiencing the impacts of plastic reaching floating ice and land, not solely as larger macroplastics (>5 cm), but as microplastics (0.1 µm—5 mm) and nanoplastics (<0.1 µm) that may be carried vast distances from their source or be ingested in more populated areas during seasonal migration.

A new review, published in Frontiers in Marine Science, has investigated the scale of this issue, particularly with respect to seabirds who call these glaciated regions home.

Across >1,100 samples, the researchers explored stomach contents, crop pouch near the throat for temporary food storage during foraging trips, guano (excrement mixture of food and metabolic waste) and regurgitated pellets of undigested food and other particles. Pellets formed the main component of the samples, followed by stomach contents and guano, while pouch contents were minimally present.

They found that 13 species of seabird inhabiting polar landscapes were reported to have ingested microplastics, including little auks, northern fulmars, glaucous gulls, thick-billed murres, white-chinned petrels, great shearwaters, sooty shearwaters, king penguins, Adélie penguins, chinstrap penguins, gentoo penguins, brown skuas and south polar skuas.

A total of 3,526 particles were extracted from these seabird samples, equating to at least 1 microplastic particle in 90% of Arctic samples and 97% for Antarctica. A median of 31.5 and 35, and average of 7.2 and 1.1, microplastic particles were found in each sample in the Arctic and Antarctica respectively. A maximum of 36 microplastic particles were found in a single bird.

Regarding plastic composition, 14 polymer types were identified, the dominant form being polyethylene, followed by polypropylene and polystyrene. These were predominantly present as fragments, derived from the breakdown of larger plastic objects. Such plastic polymer types can be sourced from items like plastic bags, food and drink containers and protective foam packaging.

The impact ingestion of plastic particles can have on seabirds includes blockage of their gastrointestinal tract, toxicity and oxidative stress, as well as triggering immune reactions. Additionally, it is not only direct ingestion of particles that is of concern, as microplastics have been found in krill, a food source for some penguins, highlighting the larger-scale issue in the ecosystem and trophic webs.

 Davide Taurozzi et al, Seabirds from the poles: microplastics pollution sentinels, Frontiers in Marine Science (2024). DOI: 10.3389/fmars.2024.1343617

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