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On August 19 (Monday), a well-known foreignscienceThe main contents of the website are as follows:

Nature website (www.nature.com)

Monkeypox virus is spreading in Africa, but a targeted drug has proven ineffective

The antiviral drug Tecovirimat did not speed up recovery in patients infected with a worrisome strain of monkeypox virus in a clinical trial in the Democratic Republic of the Congo, the National Institutes of Health (NIH) reported. This strain of monkeypox virus, called "clade I," is spreading in Africa and is thought to be more deadly than the "clade II" strain that sparked the 2022 global monkeypox outbreak.

The spread of Clade I in Congo and other African countries prompted the World Health Organization to declare a Public Health Emergency of International Concern, its highest level of alert, on August 14. The day before, the Africa Centers for Disease Control and Prevention declared the monkeypox outbreak a public health emergency in Africa for the first time.

Tivirimab was originally developed to treat smallpox, caused by a related orthopoxvirus, and is now commonly used to treat monkeypox, but clinical evidence showing that it can relieve monkeypox symptoms is limited.

Scientists reported in April that the monkeypox virus "clade I" can be transmitted between people through sexual contact. Before last year, it was thought to be spread through household contacts and contact with infected wild animals.

Patients infected with clade I were given either tevirimab or a placebo in a clinical trial sponsored by NIH’s National Institute of Allergy and Infectious Diseases (NIAID) and the Congolese National Institute for Biomedical Research. According to recently released preliminary results, tevirimab did not shorten the duration of monkeypox symptoms compared with placebo.

New York-based SIGA Technologies, the maker of Tevirima, said in a news release that trial participants who received the drug early and those with severe disease had "significant improvements." But the company has yet to release full data.

Science website (www.science.org)

To reduce wildlife deaths caused by fences, scientists turn to AI

A million kilometers of fences crisscross the western United States, enough to stretch to the moon and back. Built last century primarily to keep livestock in, these wire fences also hinder wildlife like deer, elk, and pronghorn from migrating to find food or escape deep snow. Conservationists are trying to remove or replace some of the old fences, but that means finding them across the vast expanse of the American West. To do that, researchers are turning to artificial intelligence (AI) for help.

Researchers at Germany's Senckenberg Biodiversity and Climate Research Center and Microsoft's AI Lab have trained a computer to identify fences from aerial images. Using data from field surveys, they found that the system could accurately identify about 70% of fences, they reported last week at a meeting of the Ecological Society of America. They plan to expand their method to satellite images, which could open up more possibilities for identifying fences in more areas.

A computer vision ecologist who was not involved in the study said a 70% success rate was fairly typical for early projects using AI to help solve conservation problems, adding that such projects should not be used to replace human observations but to give conservation groups and land managers more tools for making decisions.

Once the researchers refine their model, they plan to apply it to the entire western United States and then expand it to grasslands and rangelands around the globe, including in countries such as Australia and Kenya.

Science Daily website (www.sciencedaily.com)

1. What is beneath the surface?EarthPhysicists decode mysterious deep earthquake signal

Since its discovery decades ago, seismic signals known as PKP precursors have puzzled scientists.mantleThe area scatters incomingSeismic waves, these seismic waves return to the surface in the form of PKP waves at different speeds.

The origin of PKP precursor signals, which arrive before the main seismic waves traveling through Earth's core, is unclear, but research led by University of Utah geophysicists is shedding new light on this mysterious seismic energy.

According to the study, published in AGU Advances, a leading journal of the American Geophysical Union, the PKP precursor appears to have propagated from deep within North America and the western Pacific Ocean and may be associated with the "ultra-low velocity zone," a thin layer in the mantle where seismic waves slow significantly.

For nearly a century, geoscientists have used seismic waves to probe the Earth's interior, making many amazing discoveries. For example, other researchers in the United States have mapped the structure of the Earth's solid inner core and tracked its movement by analyzing seismic waves.

When earthquakes shake the Earth's surface, seismic waves travel through the mantle, a 2,900-kilometer-thick, dynamic layer of hot rock between the Earth's crust and metallic core. Researchers are interested in how these waves "scatter" as they pass through irregular features in the mantle where the composition of material changes. Some of these scattered waves are precursors to PKPs.

2. Cleaning up the aging brain: Scientists repair the garbage disposal system in mice

Neurological diseases such as Alzheimer's and Parkinson's can be considered "dirty brain" diseases because they are associated with the brain's inability to remove harmful waste. Aging is one of the key risk factors for these diseases because our brain's ability to clear out toxic waste decreases as we age. However, a new study in mice suggests that it may be possible to reverse these age-related effects and restore the brain's waste clearance ability.

The study was published in the journal Nature Aging.

In 2012, researchers first described the glymphatic system's role in the brain's unique waste removal process, using cerebrospinal fluid to flush out waste generated by energy-hungry neurons and other parts of the brain.cellThe discovery opens up new avenues for treating diseases that are often associated with the accumulation of protein waste in the brain, such as Alzheimer's and Parkinson's. In a healthy, young brain, the glymphatic system effectively removes these toxic proteins, but as we age, this system becomes less efficient, setting the stage for the onset of these diseases.

Once filled with protein waste, the cerebrospinal fluid needs to travel to the lymphatic system and eventually reach the kidneys to be disposed of along with the body's other waste products. The new study, which combines advanced imaging techniques with particle tracking technology, details for the first time the path that half of the "dirty" cerebrospinal fluid takes to drain out of the brain via the lymphatic vessels in the neck.

The researchers found that as mice aged, the lymphatic vessels contracted less frequently and their valves failed. As a result, the flow of "dirty" cerebrospinal fluid in old mice was 63% slower than in young mice.

The team then explored whether they could restore normal function to the lymphatic vessels and identified a drug called prostaglandin F2α, a hormone-like compound that is often used to induce labor and helps smooth muscle contractions. Lymphatic vessels are lined with smooth muscle cells, and when the researchers applied the drug to the neck lymphatic vessels of old mice, the frequency of contractions and the flow of "dirty" cerebrospinal fluid increased to levels seen in young mice.

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

1. Research shows that 44 and 60 are two periods of rapid aging for humans

As we enter our 40s and 60s, our bodies undergo major changes in our molecular and microbial communities that may increase our risk of health and disease, according to a study from the Stanford University School of Medicine. These changes suggest that aging is not a gradual process, but rather consists of several phases of rapid change.

The researchers evaluated thousands of different molecules in people aged 25 to 75, as well as their microbiomes — the bacteria, viruses and fungi that live in our bodies and on our skin — and found that the abundance of most molecules and microbes does not change in a gradual, step-by-step manner. Instead, we experience two periods of rapid change throughout our lives, occurring on average around ages 44 and 60. A paper describing the findings was recently published in the journal Nature Aging.

These dramatic changes could have an impact on our health - molecules associated with cardiovascular disease showed significant changes at both time points, while molecules associated with immune function also changed in the early 60s.

The new study analyzed data from blood and other biological samples donated by participants every few months over several years; in these samples, the scientists tracked many different kinds of molecules, including RNA, proteins and metabolites, as well as changes in the participants' microbiota. The researchers tracked age-related changes in more than 135,000 different molecules and microbes, totaling nearly 250 billion different data points.

The study found that in people in their forties, the number of molecules related to alcohol, caffeine and lipid metabolism, cardiovascular disease, and skin and muscle changed significantly; in people in their sixties, the number of molecules related to carbohydrate and caffeine metabolism, immune regulation, kidney function, cardiovascular disease, skin and muscle changed significantly.

2. An innovative compound kills cancer cells using a new mechanism

A research team at Ruhr-Universität Bochum in Germany has developed a compound that triggers cancer cell death via ferroptosis, which could be a promising new cancer treatment. However, further development is needed to make it specific to cancer cells.

Apoptosis has long been considered a mechanism of programmed cell death. Ferroptosis is another recently discovered mechanism that, in contrast to other cell death mechanisms, is characterized by the accumulation of lipid peroxides. This process is usually catalyzed by iron.

In order to find an alternative to the mechanism of action of conventional chemotherapy drugs, the research team at the Ruhr-Forschungszentrum Bochum specifically searched for a substance that could trigger ferroptosis. They synthesized a cobalt-containing metal complex that accumulates in the mitochondria of cells and produces reactive oxygen species, more precisely hydroxyl radicals. These free radicals attack polyunsaturated fatty acids, leading to the formation of large amounts of lipid peroxides, which trigger ferroptosis. This is the first cobalt complex specifically designed to trigger ferroptosis.

Using a variety of cancer cell lines, the researchers demonstrated that this cobalt complex can induce ferroptosis in tumor cells. Most importantly, this substance slowed the growth of artificially created micro-tumors in the experiment.