The CR400BF-GZ train, the smartest and most frost-resistant Fuxing bullet train model, was deployed in Northeast China's Heilongjiang Province on Monday. It's the coldest and highest region the model has been used in so far. The Fuxing bullet train has a maximum speed of 350 kilometers per hour.
The trains will be operating for the first time during the ongoing 40-day chunyun or the Spring Festival travel rush on routes in China's northernmost alpine region, China Media Group reported.
Compared with other Fuxing models, the CR400BF-GZ has the highest speed level. It is more resistant to low temperature and snow and can operate under an extreme cold environment of -40 C.
The advanced technology represents a major breakthrough for China's high-speed railway technology. The nation's independently developed model can meet the operational demand under various temperature conditions.
The designated system and parts used for constructing the model have all been specifically equipped with low temperature-resistant design, while ensuring smooth ventilation and effectively preventing snow and ice from entering the equipment compartment through the filter.
The train is also more intelligent with advanced technology implemented in targeted fields such as safety monitoring, aiming to further elevate the service quality.
Two sets of the trains will undergo a series of test run, and start operating on lines in Heilongjiang.
The world's first hydrogen-energy urban train with independent intellectual property rights officially rolled off the assembly line in Chengdu, Southwest China's Sichuan Province, on Wednesday. The train adopted the key core technology of the Fuxing bullet train, with a maximum speed of 160 kilometers per hour.
The "Macao Science 1" satellite that the Chinese mainland and Macao co-developed was "one of a kind" featuring great uniqueness and innovation. It is a result of international collaboration by leading scientists from around the world and has in turn attracted many Western institutes to join the work, Zhang Keke, chief scientist of the "Macao Science 1" satellite, told the Global Times in an exclusive interview.
Two "Macao Science 1" satellites were successfully launched into orbit on May 21, 2023, marking the first space science satellite program jointly developed by the Chinese mainland and the Macao Special Administrative Region.
Macao Science 1 takes a twin-satellite approach. Satellite A carries payloads including high-precision magnetometers to detect Earth's magnetic field. Satellite B is equipped with payloads like high-energy particle detectors and solar X-ray instruments to obtain space environment data.
Satellite A is the world's first low-latitude geomagnetic field and space environment scientific detection satellite, featuring the highest geomagnetic field detection accuracy in China. It will significantly improve the level of the country's space magnetic measurement technology, according to the China National Space Administration.
During an exclusive interview with the Global Times, chief scientist Zhang Keke said that they are now carrying out in-orbit testing, which is expected to be completed by the end of this year, after which they will collaborate with Western and domestic scientists to conduct scientific research based on the data obtained.
Zhang told the Global Times that the research and development of the satellite is the most challenging among all satellites of this type.
For one thing, the satellite must be non-magnetic to avoid inducing its own magnetic field, and its measuring instrument needs to be far away from all electronic instruments, generators, and other equipment.
Therefore, it was designed into a unique shape with a box sticking to the end of a long pole, extending to eight meters. This means that it has to be folded up during the rocket launch and unfold after arriving in orbit.
"When everyone was cheering for the success of the launch back then, I was actually very nervous as we waited for the pole to fully unfold. It took about two hours before we knew the unfolding maneuver had been performed perfectly," Zhang recalled.
When asked if his team has encountered any restrictions in its collaboration with Western scientists given the tense relationship between China and the US, Zhang said it wasn't an issue since "for us scientists, there should not be limitations in cooperation due to the so-called decoupling, as science knows no borders."
Many technical problems were difficult to solve, and they received help from researchers from European countries during the R&D process, Zhang said. He is now leading a team of about 30 scientists, some of whom are from the Chinese mainland and Macao, while others are from the US, UK and France among other countries.
What's more, they have signed agreements to jointly conduct research on the satellite with 18 top research institutes from around the world, including those from France, the US, the UK, and Germany.
"Westerners came to us, not the other way around," Zhang said proudly, as he introduced the unique advantages of the satellite. "The scientific project you are working on must be of interest to others, and that means it must be a first in the world. Our satellite is the first high-precision Earth magnetic field measurement satellite launched at a low inclination angle, which is of great significance to scientific advancement."
The expert further explained that the existing high-precision Earth magnetic field measurement satellites are polar satellites, mainly measuring the changes in physical parameters from the South Pole to the North Pole. And the Macao Science 1 has filled in a gap for east-west directions.
Elaborating on the importance of studying Earth's magnetic field, Zhang said that it not only provides a protective shield that blocks high-energy charged particles from the Sun from entering the atmosphere, but applies to almost every area of human beings' daily lives.
"Living on Earth, we need to know how changes occur and what changes will happen in the future. And that's really a question of the movement of the Earth's magnetic field," Zhang said.
Scientists generally believe that the magnetic field occurs in the Earth's core more than 3,000 kilometers below the surface. It is extremely hot at over 5,000 C, mainly consisting of molten iron. This produces a lot of kinetic energy, which is converted into magnetic energy, thus producing a magnetic field.
However, as humans can only drill down into the Earth's surface to a depth of 12 kilometers, we cannot see anything. The only way is to observe the changes of the Earth's magnetic field in time and space, requiring the use of satellites.
This is essential for satellite navigation for airplanes, ships, and spacecraft, which is very important for a country's economy, industry, and national security.
The three taikonauts from China's Shenzhou-15 crewed mission, known as the "dream crew," on Monday made their first appearance in public 57 days later after returning to Earth in June. The crem members shared their experience and feeling in the space and deeply felt the wonder of nature, the vastness of the universe.
China launched the manned spaceship Shenzhou-15 on November 29, 2022, sending Fei Junlong, Deng Qingming and Zhang Lu to China's space station core module Tianhe.
Having spent six months living and working in the China Space Station, the three Shenzhou-15 taikonauts safely returned to the Dongfeng landing site in the Gobi Desert, North China's Inner Mongolia Autonomous Region in June.
China Astronaut Research and Training Center has scientifically formulated a recovery plan. The recovery period is mainly divided into three stages - quarantine, recuperation and observation. So far, the crew has completed the first two stages, and they are in good physical and mental condition, and have been fully in the observation stage. They will resume regular training after completing all health and wellbeing assessments.
The four extravehicular activities (EVAs) are the highlight of our crew and the highlight of China's manned spaceship development. We believe that the following crew members will create more records, Fei said at Monday's press meeting.
"To realize a dream is not the end of the efforts, but a new starting point," Deng said. Deng has been made efforts for 25 years and finally fulfilled dream of missions in space.
Zhang who took the mission in the space for the first time took a lot of beautiful photos in space, many of them are about the motherland and hometown. Zhang again and again in the window looked at the motherland, and Zhang said that what impressed him most was extravehicular activities.
"Before my first extravehicular activities, I had been looking out of the porthole, which was so small that I couldn't get a full view." When I was faced with the boundless space for the first time, "I had a deep understanding of the wonders of nature and the vastness of the universe," Zhang said.
China has unveiled its preliminary plan on manned lunar landing. China planned to land its taikonauts on the moon before 2030 to carry out scientific exploration, according to a preliminary plan released by the China Manned Space Agency in July.
"We are fully aware of the mission and responsibility on our shoulders. We firmly believe that with scientific and systematic training, the full support of space science and technology staff, the unity of our crew, we can overcome any difficulty," Fei noted.
In half a month, two economic powerhouse provinces in East China relaxed their household registration limits, leaving many wondering what the lifting of rule which once restricted migration between rural areas and cities signals for the country?
Household registration, known as hukou in Chinese, was formed in 1958. It serves to categorize citizens as either rural residents or non-rural residents.
For a long period, almost all large cities have set strict household registration thresholds, the more economically developed, the higher the bar for registering a local hukou. Obtaining a Beijing and Shanghai hukou could be very difficult as the top cities tend to restrict population growth from becoming overcrowded.
Jiangsu Province recently drafted regulations aiming to relax limits for registering a hukou, allowing residents from rural areas to register themselves in cities, except Nanjing and Suzhou.
Earlier, except provincial capital of Hangzhou, Zhejiang Province also announced to ease restrictions.
A VOA report interpreted the policy shift aimed at propping up China's housing market.
Ma Li, former director of China Population and Development Research Center, told the Global Times that the driving force behind allowing new arrivals to become permanent residents in urban areas is aimed at expanding the available urban talent pool to boost local economic development.
Propping up the housing market is not an explicit goal set by officials, but could be one of those benefits of scrapping household registration limits, Ma noted.
Niu Fengrui, a researcher from Institute of Urban Environment, Chinese Academy of Sciences, told the Global Times that linking the current economic situation to hukou policy reform is too short-sighted, because the essence of lifting household registration curbs is aimed at closing the gap between rural and urban regions and accelerating the urbanization of rural populations, allowing citizens to enjoy equal basic public services, which serves the overall goal of achieving the country's modernization for the wellbeing of all Chinese people.
Optimizing population distribution
The reform of allowing rural hukou holders to register in urban cities is not a new concept. In 2014, the third meeting of the Central Leading Group for Comprehensively Deepening Reform proposed to facilitate 100 million rural migrants and other residents to resettle into urban areas by 2020.
Previously, Guizhou, Sichuan, Inner Mongolia, Hainan, Guangxi and other jurisdictions have also proposed full opening-up of household registration. At least 18 provinces in China have relaxed restrictions on household registration to date, according to media reports.
However, the policy shift may be less attractive to current residents in rural areas as obtaining a urban hukou leads to a possibility of losing their rural land contracting rights and their rights to use residential land. In well-developed provinces including Zhejiang, the shortened gap between rural and urban regions' living standards means any move to further relax restrictions only delivers marginal benefits, Ma noted.
But, rural hukou holders who now work and live in urban areas will certainly embrace the change which allows them to move their permanent place of residence to larger cities. It will grant them the equal access with urban citizens to employment, social security, family planning and other social services, Ma said.
Zhejiang Province said it will increase quotas for public schools and improve capacity for children of residence permit holders to receive education.
Cai Fang, former vice president of the Chinese Academy of Social Sciences, calculated that the number of migrant workers who live in urban areas but do not hold an urban hukou is likely between 130 million and 170 million.
But Ma also noted if rural hukou holders convert their registration to an urban area but still are allowed to hold their rural land contracting rights, an urban hukou would become very attractive because of access to better education and employment in cities. "Cities are on the process of optimizing the relevant measures."
For provincial capital cities including Hangzhou, first-tier cities including Beijing, Shanghai, Shenzhen and Guangzhou where public resources are already stretched, however, the opening up of the household registration policy is unlikely in the short term, experts said.
According to a recent announcement by China's Ministry of Public Security (MPS) on further relaxing household registration, a points-based household registration system for mega cities with a permanent urban population of over 5 million will also be optimized, encouraging local governments to lift restrictions on annual quotas for local household registration.
"The removal of the household registration system has been discussed for many years in China, I personally believe that the economic and social conditions to scrap the policy are already in place, but the traditional mindset of hukou has slowed down the process of household registration reform."
The lifting of hukou restrictions will lead to the concentration of populations in urban areas and the decline of rural populations, several demographers noted.
Following major reform and opening-up, China's urbanization level has increased rapidly, rising from 17.92 percent in 1978 to 64.72 percent in 2021, with the country's urban population reaching 914.25 million, the Guangzhou Daily reported citing Xiao Jincheng, former director of Institute of Land Development and Regional Economy affiliated with the NDRC.
In other words, every year, more than 10 million people move from rural areas to urban areas, find jobs and live in cities. It is believed that China's urbanization level will exceed 70 percent by 2030 and 80 percent by 2050. In the next decade, more than 100 million people will migrate from rural areas to cities and towns, Xiao said.
In the future, as more rural hukou holders move to cities, the country's rural areas are expected to be revitalized as technology-empowered agriculture will nurture professional farmers and ensure talent remains in the farming economy, Ma told the Global Times. "Like those towns in Europe, each town has its own characteristics and own way of development."
Achieving the country's modernization is the process of re-optimizing the layout of China's population, Niu concluded.
Over the ground lies a mantle of white — on Pluto. Snow-capped peaks on the dwarf planet dot an otherwise ruddy terrain. But these snowy summits appear to be composed of methane, not water, researchers report online March 3.
Mountain tops in Pluto’s Cthulhu Regio, a dark landscape abutting the planet’s famous heart, reflect more light than the surrounding area. The New Horizons spacecraft, which flew past Pluto on July 14, found that the bright regions correspond to surface deposits of methane. Mission scientists speculate that perhaps methane in the atmosphere on Pluto behaves like water in the air on Earth, building up on the ground as frost at the highest (and coldest) elevations.
New microscopy images of the virus reveal a bumpy, golf ball‒shaped structure, similar to that of the dengue and West Nile viruses, researchers report March 31 in Science. It’s the first time scientists have gotten a good look at Zika, the infamous virus that has invaded the Americas and stoked fears that it is causing birth defects and a rare autoimmune disease (SN: 4/2/16, p. 26). Cracking Zika’s structure is like getting the blueprints of an enemy’s base: Now scientists have a better idea of where to attack. “This certainly gives us great hope that we will be able to find a vaccine or antiviral compounds,” says study coauthor Michael Rossmann of Purdue University in West Lafayette, Ind., who’s known for mapping the first structure of a common cold virus in 1985.
Researchers have been racing to solve Zika’s structure, says UCLA microbiologist Hong Zhou. “I was trying to work on the same thing myself.” But the new study’s authors beat everybody. “I was impressed they were able to do it so quickly,” Zhou says.
Rossmann and colleagues imaged a strain of Zika collected from a patient during a 2013‒2014 outbreak in French Polynesia (the strain is nearly identical to the one now spreading through Latin America).
The team used a technique called cryoelectron microscopy to create a three-dimensional picture of Zika. It’s a pretty sharp image, says study coauthor Devika Sirohi, also of Purdue. She and colleagues can clearly see the virus’ shape and can even make out sugars protruding from its surface.
These sugars, which look like little red doorknobs, hang from proteins in Zika’s shell. The knobs may help Zika attach to — and infect — human cells. The team discovered that Zika’s knobby regions look slightly different from those of related viruses. Zika’s sugar-decorated proteins “fold a little differently,” Sirohi says. And that might let Zika make different contacts with attachment sites on cells, called receptors. That could “influence what kind of cell the virus infects,” she says. These differences could explain why Zika infects cells not typically targeted by dengue or West Nile. One of the receptors targeted by Zika could be AXL, a protein crowded on the surface of neural stem cells, researchers propose March 30 in a separate study published online in Cell Stem Cell. Zika virus is thought to preferentially infect these early-development brain cells, and it could potentially use AXL as an easy entry point, study coauthor Arnold Kriegstein of the University of California, San Francisco and colleagues suggest.
Of course, exactly what role subtle structural differences play in Zika’s infection ability is “only speculation at this point,” Sirohi says. The team now plans to test how tweaking the knobby regions of the virus affects Zika’s virulence.
Some people can evade diseases even though they carry genetic mutations that cause serious problems for others.
Researchers found 13 of these genetic escape artists after examining DNA from nearly 600,000 people, the scientists report online April 11 in Nature Biotechnology. Learning how such people dodge genetic bullets may help move inherited-disease research from diagnosis to prevention.
Hundreds of mutations that lead to genetic diseases have been uncovered since the discovery of a disease-causing flaw in the “cystic fibrosis gene” in 1989. But, says study coauthor Stephen Friend, “finding the gene that causes the disease is not the same as finding a way to prevent the symptoms or manifestations of that disease.” Clues to preventing genetic diseases could come from studying people who should have gotten sick but didn’t, suggest Friend, of the Icahn School of Medicine at Mount Sinai in New York City, and colleagues. Finding people like that is a challenge, though, because they don’t have symptoms.
To find such people, the team assembled existing genetic data from 589,306 adults who had their DNA tested as part of 12 ongoing or past studies. The researchers then searched for mutations known to cause genetic diseases in childhood. Since study participants were adults, they should already have developed symptoms.
Initially, the researchers found more than 15,000 potential escape artists. Further analysis whittled the field to 42. Of those, medical records indicated that 14 had symptoms of their genetic disease after all. Another 15 were ruled out because a closer examination found that each person had only one copy of a mutated gene. The other copy was normal, so could compensate for the debilitated copy.
The remaining 13 people carried mutations associated with one of eight different diseases, but somehow had not developed symptoms. The study suggests that it is possible to find people who are resistant to getting genetic diseases.
But some resilient people may have been missed because the study included only a fraction of known disease-causing mutations, says Daniel MacArthur, a geneticist at Massachusetts General Hospital in Boston. More troubling is that the researchers could not confirm that resistant people were disease-free or verify that they really have mutations. That’s because consent forms signed when participants agreed to share their genetic information did not contain provisions for researchers to contact volunteers later for retesting. “Some of their resilient cases may be mirages,” MacArthur wrote in a commentary, also in Nature Biotechnology. Garry Cutting, a medical geneticist at Johns Hopkins School of Medicine, is also concerned that some of the lucky 13 may not be true escape artists. Cutting studies genes and environmental factors that determine the severity of cystic fibrosis, a disease in which thick mucus builds up in the lungs, pancreas and other organs. People develop the disease when they inherit two defective copies of the CFTR gene. More than 1,800 mutations in that gene can cause the disease if inherited in double copies or in combinations of mutations.
Of the 13 resilient people in the study, three carry dual copies of a very rare mutation in the CFTR gene, but don’t have cystic fibrosis.
Only one person in a database of 88,000 cystic fibrosis patients carries two copies of the rare mutation. So finding three people with double copies of the mutation is extraordinary, Cutting says. “It’s so exceptional that I believe it requires more extensive verification.”
He says he would be “delighted” if the people really turn out to be resistant to getting cystic fibrosis, but he’s puzzled why that mutation alone allows escape. It could be that a variant in another gene counteracts that specific mutation in the CFTR gene. Or a second mutation in the mutant CFTR gene may reverse the effect of the disease-causing one. However, it is possible that the three people avoided cystic fibrosis because they have only one copy of the mutated gene and one healthy copy that the researchers missed with the methods they used, Cutting says.
MacArthur points out another potential drawback to the study: Even if the researchers expand the study to 1 million or more people, they may not discover enough “genetic superheroes” to create a sample size large enough to detect protective genes. Such an effort may require participation from hundreds of millions of people and researchers willing to share data on a global scale.
Normal is the new strange for the world’s largest cave salamanders.
Biologists are thinking deep thoughts about why some of Europe’s olm salamanders living in darkness have (gasp!) skin coloring and eyes with lenses.
Most salamanders, of course, have skin pigments and grow adult eyes like other vertebrates. But after eons of cave life, olms (Proteus anguinus) have become mostly pinkish-white beasts, about 30 centimeters head to tail, that spend long lifetimes (maybe 70 years) slinking in cold, subterranean water. Living at 11 to 12° Celsius, olms don’t mature sexually until about age 11 for males and 14 for females. Even then, they never really grow up, staying in water like giant larvae and keeping such youthful features as neck fluff gills into old age. “They look a little creepy, especially if you look at the skull,” says Stanley Sessions of Hartwick College in Oneonta, N.Y. Their blunt heads have no real upper jaw, and their adult eyes start to form but then regress to nubbins buried under skin. These salamanders live frugally. They can go more than a year without eating. (Lilijana Bizjak Mali of the University of Ljubljana in Slovenia says a lab-dwelling olm survived even after more than 10 years without food.) Females take six-to-12-year breaks between laying eggs, which “develop extraordinarily slowly,” Sessions says. Recently laid olm eggs in Slovenia’s Postojna Cave took about seven weeks to start forming a nervous system; a common spotted salamander takes about one.
Among extreme cave-lifers, the oddballs are the more normal-looking salamanders (for now, called subspecies parkelj), with dark skin and better-developed eyes. For decades, biologists treated these curios as remnants of the most ancient olms that haven’t shed all their daylight ways. But rather than putting the dark salamanders at the base of the genealogical tree of olms, a genetic analysis places them higher among more recent, pale lineages.
“This forces you to consider that the black one probably evolved from white ancestors by reversing cave adaptations,” Sessions says. In evolution, “weirder things have happened.”
Three Earth-sized planets orbiting a star practically next-door might be a good place to hunt for alien life — or at least check out some worlds that are different from anything in our solar system.
The planets orbit a dim, cool star just 39 light-years away in the constellation Aquarius. Each is outside or possibly on the edge of the star’s habitable zone — where average temperatures are just right for liquid water. But there could be niche locales on these worlds where alien life might thrive, Michaël Gillon, an astrophysicist at University of Liège in Belgium, and colleagues report online May 2 in Nature. A year on the two inner planets lasts just a couple of days. Data on the third world are sparse; it could take anywhere between 4.5 and 72.8 days to trek around its sun. The star, designated 2MASS J23062928−0502285, is roughly the size of Jupiter — about one-tenth as wide as our sun — and about 3,200 degrees Celsius cooler than the sun. Such runts make up about 15 percent of the stars in the galaxy, though astronomers had not found planets around one before. All three planets were discovered as periodic dips in starlight in late 2015 using TRAPPIST, a telescope at La Silla Observatory in Chile.
If anything does crawl or grow on these worlds, it bathes in mostly infrared light. The innermost planets receive several times as much energy from their star as Earth does from our sun, which technically puts them outside the star’s habitable zone (SN: 4/30/16, p. 36). But the planets are huddled up so close to the star that gravity might keep them from spinning, creating a temperate zone along the line where day turns to night, the researchers suggest.
Faint red stars such as this one are the best place to look for warm rocky planets, says Nicolas Cowan, an astronomer at McGill University in Montreal. Planets, even small ones, are easier to see around these dim bulbs rather than sunlike stars. NASA’s planet-hunting Kepler space telescope has already shown that planets exist around similar stars, but those are too far away to investigate further. “This [study] finds a nearby example,” says Cowan.
Being nearby is important for studying the atmospheres of such worlds, or learning whether they have atmospheres at all. They may not. Red dwarf stars take a long time to form; planets arise while their sun is still a puffy, temperamental ball of contracting gas. “That might bake off all the water and the atmosphere,” Cowan says. Astronomers won’t know, though, until they point some big telescopes toward these worlds.
The Hubble Space Telescope might be able to get a crude look. But NASA’s James Webb Space Telescope, scheduled to launch in 2018, could gaze at these planets and measure how much starlight is being absorbed by molecules in their atmospheres. If there is an atmosphere, James Webb could look for such gases as oxygen and methane (SN: 4/30/16, p. 32). On Earth, at least, those gases are produced by plants and microbes.
Whether or not life has found a home on these worlds, all offer a peek at unfamiliar environments. The two planets closest to the star, for example, are bombarded with more energy than Venus, notes Lisa Kaltenegger, an astronomer at Cornell University. “How would Venus evolve if you heat it up even more?” she asks. “We don’t have such planets in our own solar system, so it is really interesting to find out what such planets can be like.”
New sperm-catching beads could someday help prevent pregnancy — or enable it.
Researchers created microscopic polymer beads that mimic unfertilized eggs and trap passing sperm. The beads are coated in the sperm-binding section of a protein called ZP2. In mammals, ZP2 is found in membranes around unfertilized eggs; sperm must bind to the protein before entering the egg.
The beads could be used as short-term contraceptives, Jurrien Dean of the National Institutes of Health in Bethesda, Md., and colleagues report in the April 27 Science Translational Medicine. In the laboratory, human sperm attached to the beads within five minutes. The researchers then mixed 100,000 human sperm with 1.5 million beads and 28 mouse eggs containing human ZP2 proteins. After 16 hours, only one sperm reached an egg. In another experiment, beads coated with mouse ZP2 delayed pregnancy when injected into the uteruses of mating female mice. Bead-free mice took just over 28 days, on average, to conceive and give birth; bead-treated mice didn’t have babies for nearly 73 days on average. The beads didn’t appear to cause swelling or damage, and treated mice were able to give birth again within five months.
The beads could also help combat infertility. In an egg-penetration test, researchers gently detached bead-captured sperm and pitted those sperm against a control batch of sperm that had not been exposed to the beads. More than half of eggs (mouse eggs with human ZP2) exposed to the bead-selected sperm ended up with three or more sperm attached to them; none of the eggs exposed to the control group snagged three or more sperm. In fact, the control group failed to penetrate 38 out of 50 eggs. So the beads could someday be used to select healthy sperm for assisted reproduction, the researchers say.
But it’s not clear if the ability to bind to ZP2 necessarily indicates a healthy sperm, says Andrew La Barbera, chief scientific officer of the American Society for Reproductive Medicine in Birmingham, Ala. “Sperm selection is a very complex undertaking because of the fact that sperm are very complex,” he says. “We don’t know what makes a good sperm.”
Contraception might be a more reasonable future use for the beads, although allowing fertilization of one in 28 eggs is underwhelming, La Barbera says. Birth control should be closer to 99.9 percent effective. “It only takes one sperm to fertilize an egg,” he says. Still, the beads’ performance at blocking pregnancy in mice seems promising, La Barbera says. Future experiments would need to determine if the beads are safe and effective in women, and how many beads are needed to prevent conception.
Dean notes that the study is a proof of principle. Many unknowns must be evaluated before using the beads for birth control, including the side effects of long-term use, he says. “Although promising, we are a long way from translating these basic laboratory observations into useful clinical applications that provide people with better reproductive choices.”
