news

한어Русский языкEnglishFrançaisIndonesianSanskrit日本語DeutschPortuguêsΕλληνικάespañolItalianoSuomalainenLatina

On August 1 (Thursday), the main contents of the well-known foreign scientific website are as follows:

《nature》Website (www.nature.com)

Studies have found that there are a lot ofimmunitycell, always ready to fight against viral and bacterial infections

The nose is home to a large number of long-lived immune cells that form the lungs' first line of defence, ready to ward off invading viruses and bacteria, according to the most detailed research to date.

The study, published recently in the journal Nature, shows that the nose and upper respiratory tract (which includes the mouth, sinuses and throat, but not the trachea) are key training grounds for immune cells to "remember" invading pathogens. This memory allows the cells to defend against future attacks by similar microbes. The findings could lead to the development of mucosal vaccines that are delivered through the nose or throat, which immunologists say could be more effective than vaccines injected into the muscle.

The "exciting research" showed that a "reservoir of immune cells capable of fighting off respiratory infections" could be reliably detected in the upper respiratory tracts of both young and old people, two age groups where immune responses are typically weaker.

Previous studies of the immune system have focused on immune cells in the blood and lower respiratory tract, largely because those areas are relatively easy to sample through blood draws and certain types of biopsies and organ donations, noted study co-author Sydney Ramirez, an infectious disease physician and immunologist at the La Jolla Institute for Immunology.

However, the COVID-19 pandemic and the mutation of the new coronavirus have led to a need for a deeper understanding of how immune cells in the upper respiratory tract interact with pathogens and form immune memory. The research team turned to nasopharyngeal swabs, which can reach the back of the nose and are widely used for new coronavirus testing in high-income countries. The researchers sampled about 30 healthy adults every month for more than a year to see how their immune cell populations changed over time. In these samples, they found millions of immune cells, including cells responsible for providing immune memory.

Science News website (www.sciencenews.org)

New research confirms that some "permanentChemical"Potassium" may be absorbed through the skin

PFAS (per- and polyfluoroalkyl substances) are a class of thousands of man-made compounds. Because the chemical bond between carbon and fluorine in PFAS is almost unbreakable, they are called "forever chemicals." Since the 1940s, these chemicals have been mass-produced and used in a variety of products from non-stick pans to stain-resistant and water-resistant fabrics, consumers have been exposed to them for a long time. Although these chemicals were once widely used to improve the quality of life, over time, studies have shown that they are harmful to the human body, difficult to degrade, and ubiquitous in the environment.

Previous studies have shown that skin absorption is one of the potential ways for humans to be exposed to PFAS. However, relevant research is relatively limited and the data is insufficient. For example, studies have shown that PFAS can penetrate the skin of mice, but "mouse skin cannot directly mimic human skin."

Environmental chemists at the University of Birmingham in the United Kingdom report in the latest issue of the journal Environment International that when a 3D human skin model was exposed to PFAS, the chemicals were able to cross the skin barrier. This finding suggests that these compounds may be absorbed into the body through the skin and may even enter the bloodstream.

In the study, researchers tested 17 PFAS in various products that come into contact with human skin. They found that 11 of them were able to penetrate the skin barrier; moreover, those with only 4 to 7 carbon atoms were more easily absorbed by the skin than those with more carbon atoms. These shorter-chain PFAS are seen as safer alternatives to the original permanent chemicals, but studies show that they are just as problematic.

"We can't be 100 percent sure that PFAS end up in the bloodstream, but they are able to penetrate the skin, which is the first step in the permeation process," the researchers noted.

Science Daily website (www.sciencedaily.com)

1. Genes or environment? A new model for assessing disease risk factors

Every disease is influenced by both genetic factors and environmental factors, including air pollution, climate, and socioeconomic status. However, it is not clear how much of a role genes or environment play in disease risk, and how big each factor is. As a result, people are often unclear about what steps they can take to reduce their risk of disease.

A research team led by researchers at Pennsylvania State University College of Medicine has developed a method to analyze genetic and environmental influences on disease risk using a large, nationally representative sample. They found that in some cases, previous assessments overemphasized the impact of individual genes on disease risk, while lifestyle and environmental factors actually have a greater impact than previously thought. Unlike genes, environmental factors such as air pollution can be easily changed. This means that there are more opportunities to reduce disease risk by changing the environment. The research results were published in Nature Communications.

Environmental risk factors have been difficult to quantify and assess in the past because they cover everything from diet to exercise to climate, the researchers said. But if environmental factors are not taken into account in models assessing disease risk, analyses may incorrectly attribute disease risks shared among family members to genetics.

For the study, the team developed a spatially mixed linear effects (SMILE) model that combines genetics and geographic location data, with geographic location serving as a proxy for environmental risk factors at the community level.

The team's analysis allowed for more precise estimates of disease risk factors. For example, previous studies had suggested that genetics accounted for 37.7 percent of the risk of type 2 diabetes. When the team re-evaluated these data, taking into account environmental influences, their model found that the genetic contribution to type 2 diabetes risk was reduced to 28.4 percent; a greater proportion of the disease risk could be attributed to environmental factors. Similarly, after adjusting for environmental factors, the estimated genetic contribution to obesity risk dropped from 53.1 percent to 46.3 percent.

2. Mucus-based bio-ink can be used to print and culture lung tissue

Millions of people die from lung diseases every year. Treatment options for lung diseases are limited, and existing animal models and experimental drugs are unable to meet research needs. A research team from the Indian Institute of Technology has successfully developed a mucus-based bio-ink that may be used for 3D printing and culturing lung tissue in the future, providing a new avenue for the study and treatment of chronic lung diseases.

The research team started with mucin, a component of mucus that has not been widely used in bioprinting. They reacted mucin with methacrylic anhydride to form methacrylic mucin (MuMA), which was then mixed with lung cells. To increase the viscosity of the bio-ink and promote cell growth and adhesion, the research team also added hyaluronic acid, a natural polymer found in connective tissue, among other things.

After printing the ink into circular and square grid test patterns, the researchers exposed it to blue light to cross-link and solidify the MuMA molecules. They found that the pores in the printed gel were interconnected, promoting the diffusion of nutrients and oxygen, which aided cell growth and the formation of lung tissue. These printed structures are biocompatible and slowly biodegrade under physiological conditions, making them possible to use as implants, where newly grown lung tissue will gradually replace the printed scaffolds. In addition, this bio-ink can also be used to create 3D lung models to study the progression of lung disease and evaluate potential treatments.

Scitech Daily website (https://scitechdaily.com)

1. Scientists have discovered the world's most efficient solar system: it was not created by humans

Giant clams in the western Pacific Ocean may be the world's most efficient solar energy systems, a new Yale-led study suggests that engineers designing solar panels and biorefineries could gain valuable insights from these iridescent giant clams that live near tropical coral reefs.

That's because the giant clams have a precise geometry -- a thin light-scattering layer covering dynamic, vertical columns of photosynthetic receptors -- that makes them perhaps the most efficient solar energy system on Earth.

In the study, published in the journal PRX: Energy, the team proposed an analytical model to assess the maximum efficiency of photosynthesis based on the geometry, movement and light scattering properties of giant clams. This is the latest in a series of studies on biological mechanisms in nature that highlight the potential of natural bioenergy to inspire new sustainable materials and designs.

"It is conceivable that future generations of solar panels could be grown from algae, or made from cheap plastic solar panels that are resilient," the researchers noted.

2. Chinese scientists introduce game-changing all-solid-state lithium battery technology

The new strategy for all-solid-state lithium batteries (ASLBs) uses a special material to increase the energy density and life of the battery without the need for additional additives. This breakthrough ensures that the battery can operate effectively for more than 20,000 cycles, marking a major advance in battery technology.

Researchers from the Qingdao Institute of Bioenergy and Process Technology (QIBEBT) of the Chinese Academy of Sciences, together with collaborators from leading international institutions, have introduced this innovative cathode homogenization strategy for all-solid-state lithium batteries. In a paper recently published in the journal Nature Energy, they detailed this new approach, which significantly improves the cycle life and energy density of all-solid-state lithium batteries, representing an important advance in energy storage technology.

One of the challenges facing all-solid-state lithium batteries is the problem of heterogeneous composite cathodes, which usually require electrochemically inactive additives to enhance conductivity. Although these additives are necessary, they reduce the energy density and cycle life of the battery due to their incompatibility with layered oxide cathodes, which undergo large volume changes during operation.

The researchers developed a cathode homogenization strategy using the zero-strain material Li1.75Ti2(Ge0.25P0.75S3.8Se0.2)3 (LTG0.25PSSe0.2), which exhibits excellent mixed ionic and electronic conductivity, ensuring efficient charge transport throughout the charge-discharge process without the need for additional conductive additives.

By solving key challenges in all-solid-state lithium batteries, this strategy lays the foundation for innovation in future energy storage technologies. The team plans to further explore the scalability of LTG0.25PSSe0.2 materials and their integration into practical battery systems. (Liu Chun)