Green, red, and yellow kiwifruit: how nutritious are they? Ancient virus resurrection and human aging | Hot topic review

"Hotspot Review | Major Technology Events of the Week" is a new column with pictures and texts launched by Academic Headlines, which aims to help readers quickly understand the hot technology news of the past week. Due to the limited space (and knowledge), everyone is welcome to add more~

You eat the same food, so why are you fatter than him?

Why do some people gain weight more easily when eating the same food? This may be related to the composition of intestinal microorganisms.

Recently, a study published in the scientific journal Microbiome showed that on average, the composition of intestinal microorganisms in some Danes allows them to extract more energy from food.

According to the paper, the researchers studied the residual energy in the feces of 85 Danes to assess the efficiency of intestinal microorganisms in extracting energy from food.

The results showed that about 40% of the participants consumed more energy from food on average compared to other participants, and those who consumed the most energy from food gained an average of 10% (about 9 kg) in weight .

In this study, the researchers divided the intestinal microbes of most participants into three types: type B (Bacteroides), type R (Ruminococcus) and type P (Prevotella). Participants who consumed more energy had a type B intestinal microbe composition, which was dominated by Bacteroides . This microbial composition was more efficient in absorbing nutrients from food.

The researchers said that the current study cannot directly prove that residual energy in feces is related to weight gain, because people with less residual energy in feces will also have an average increase in weight.

Source: China Science Daily

Paper link:

https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-022-01418-5

Green, red and yellow kiwis, what are their nutritional values?

Kiwifruit has a unique flavor, aromatic fragrance and high nutritional value, and is very popular among consumers. In recent years, people's demand for fruit quality has gradually increased, and nutritional value is crucial to fruit quality.

Recently, researchers from Wuhan Botanical Garden of the Chinese Academy of Sciences studied 14 kiwifruit varieties to explore the physical and chemical properties and nutritional quality of different kiwifruit varieties. They analyzed kiwifruit pectin, water content, chlorophyll, carotenoids, flavonoids, energy, carbohydrates, protein, fat, dietary fiber, soluble sugars, organic acids, vitamins and aroma based on kiwifruit flesh color and species classification.

Studies have shown that the pectin content of green kiwifruit is significantly higher than that of red and yellow kiwifruit. Red kiwifruit has the highest sugar-acid ratio and total flavonoids content, while the lowest fat and dietary fiber content. In addition to chlorophyll content, the total carotenoid content of green kiwifruit is also significantly higher than that of red and yellow kiwifruit. Yellow and green kiwifruit have low energy and low carbohydrate content.

In addition, the protein content of Actinidia chinensis and Actinidia deliciosa was higher than that of other species. Four specific volatile compounds were found in red-fleshed kiwifruit, which can be used as the characteristic aroma of red-fleshed kiwifruit.

Source: Wuhan Botanical Garden, Chinese Academy of Sciences

Paper link:

https://www.mdpi.com/2304-8158/12/1/108

Ancient virus revived in human genome drives aging

The co-evolutionary relationship between viruses and humans is complex.

On the one hand , viruses cause humans to suffer from diseases and even die, and in the process they continuously exploit and transform the human genome; on the other hand , the human immune system actively fights against viral invasion, causing the viral sequences integrated into the human genome to gradually be taken over by the genetic regulatory system of the host cells and co-evolve.

Endogenous retroviruses (ERVs) are relics of ancient retroviruses that invaded and integrated into the human genome millions of years ago - "ancient virus fossils". Over the long years, a large amount of ERV genetic information has been captured by human cells, and through mutations, deletions and other changes, it has become the "dark matter" lurking in the human genome, occupying about 8% of the human genome sequence and becoming an important genetic memory .

Aging is one of the biggest risk factors for chronic diseases in humans. The human genome contains many "aging" signals, which are usually silenced by strict epigenetic regulation. However, during the aging process, due to epigenetic disorder, these "aging" signals escape control and activate a series of aging programs in cells. It is still unknown whether ERV ancient virus elements, which occupy a large proportion of the human genome sequence and are as silent as a "dead volcano", are involved in the programmed regulation of aging.

Recently, scientists discovered for the first time that a young ERV subfamily is reawakened during cellular aging , proposed the theory that ancient virus resurrection mediates the programming and infectiousness of aging, and innovatively developed a multi-dimensional intervention strategy to block the resurrection and spread of ERV ancient viruses in order to delay aging.

This study systematically defines and reveals that aging-induced resurrection of endogenous retrovirus (AIR-ERV) can serve as a driving force and measurement marker for the aging of cells, organs and even the body, providing a new theoretical basis for the programming, cascade amplification and intervention of aging, and providing important clues and ideas for the scientific assessment and early warning of human aging, and the prevention and treatment of aging and aging-related diseases.

Source: Institute of Zoology, Chinese Academy of Sciences

Paper link:

https://www.cell.com/cell/fulltext/S0092-8674(22)01530-6

How does a high-fat diet help the gut microbiota slow down aging?

There is increasing evidence that the intestinal flora plays a key and dominant role in the occurrence and development of aging and aging-related diseases. Dietary intervention can reshape the flora and significantly affect the body's metabolism, nutritional balance and even immune system function.

In recent years, researchers have found that increasing the proportion of fat energy in the diet (such as high-fat diet, ketogenic diet) can enhance the movement and memory function of naturally aged mice or premature mice, reduce mortality, and extend healthy life span. However, little is known about the role of intestinal flora in this process.

Recently, Professor Wang Zhao's research group at the School of Pharmacy at Tsinghua University published a research paper online in a professional journal in the field of aging, reporting that a high-fat diet rescued the premature aging-related phenotypes of SIRT6 knockout mice by improving intestinal flora, providing a theoretical basis for the importance and rationality of formulating dietary plans based on flora regulation.

The experimental results showed that SIRT6 knockout mice showed typical signs of intestinal dysbiosis , including reduced bacterial diversity, lower levels of short-chain fatty acids in feces, decreased abundance of probiotic Bacteroidetes, and increased abundance of pathogenic bacteria such as Enterobacteriaceae, Verrucomicrobiaceae, Proteobacteria, and Prevotellaceae.

When the intestinal flora of SIRT6 KO mice was transplanted into young wild mice, the wild mice showed accelerated aging-related phenotypes, including an increase in the amount of white coarse hair, lower blood sugar levels, reduced fat accumulation , and increased expression levels of inflammatory factors (TNFα, IL-1β, IL-6) and aging markers (P16, P21) in multiple tissues and organs.

While the high-fat diet increased the survival rate of SIRT6 KO mice and improved hypoglycemia, it also reshaped their microbiota, especially significantly reducing the level of Escherichia coli and the displacement of Enterobacteriaceae in internal organs. Transplanting the microbiota of SIRT6 KO mice after dietary intervention to KO mice again can still effectively reduce the expression levels of inflammatory factors and aging markers in the tissues and organs of KO mice .

Source: Tsinghua University

Paper link:

https://onlinelibrary.wiley.com/doi/10.1111/acel.13760

Fatty liver is harmful to the brain

Recently, a research team from King's College London and the Roger Williams Liver Institute affiliated with the University of Lausanne in Switzerland found in a study on the link between non-alcoholic fatty liver disease (NAFLD) and brain dysfunction that the accumulation of fat in the liver can lead to brain hypoxia and inflammation of brain tissue , both of which have been shown to lead to serious brain diseases.

In the study, half of the mice consumed a diet containing no more than 10% fat in their calories, while the other half consumed a diet containing 55% fat, the latter designed to mimic processed foods and sugary drinks.

The results showed that all mice that consumed high levels of fat developed symptoms of obesity after 16 weeks and developed NAFLD, insulin resistance and brain dysfunction.

Lead author Dr Anna Hadjihambi, Deputy Head of the Liver-Brain Axis Group at the Roger Williams Institute for Liver Diseases and Honorary Lecturer at King's College London, said: " The impact of fat accumulation in the liver on the brain is very worrying because it starts out mildly and can persist for years without people knowing it. "

To combat the damaging effects of NAFLD on the brain, the scientists bred mice with lower levels of a specific protein, called monocarboxylate transporter 1 (MCT1), which is specifically responsible for transporting energy substrates that enable the proper functioning of various cells.

Source: China Science Daily

Paper link:

https://www.journal-of-hepatology.eu/article/S0168-8278(22)03008-2/fulltext

Nature cover: Scientific progress is "slowing down"

Recently, a research team from the University of Minnesota and the University of Arizona analyzed 25 million papers (1945-2010) in the Web of Science (WoS) and 3.9 million patents (1976-2010) in the PatentsView database of the United States Patent and Trademark Office (USPTO) and found that disruptive science and technology have become increasingly scarce in the past 60 years, and scientific progress is "slowing down". The core points are as follows:

Papers and patents published in recent years are unlikely to be disruptive or render previous discoveries (such as the DNA double helix) obsolete and push science and technology in new directions;

Instead, papers and patents are more likely to consolidate or further develop previous work, such as the Kohn-Sham equation;

Scientists and inventors increasingly use narrower pieces of knowledge to develop their new work;

This pattern holds true across all major scientific fields, including technology, medicine, and the social sciences. The downward trend is unlikely to be caused by changes in the quality of published work or citation policies, the paper says, but rather because scientists and inventors have relied on a narrower set of existing knowledge in recent decades, which has benefited individual careers but harmed scientific progress more generally.

" A healthy scientific ecosystem includes both improvements to previous work and new disruptive discoveries, but the nature of research is changing ," said Russell Funk, an assistant professor at the University of Minnesota and the corresponding author of the paper. "As incremental innovation becomes more common, it may take longer to achieve key breakthroughs that clearly advance science in the future."

Paper link:

https://www.nature.com/articles/s41586-022-05543-x

33-53 years old, the most sleep-deprived in the past 20 years

Recently, a study published in the scientific journal Nature Communications showed that people sleep less in middle age than in early and late adulthood - starting from early adulthood, people's sleep time will gradually decrease until the age of 33, and then rise again at the age of 53.

In this study, research teams from the UK and France recruited 730,187 participants from 63 countries to reveal how sleep patterns change throughout the life cycle and how they differ between different countries.

The study found that the youngest participants (19 years old) slept the most. Sleep time for participants in their 20s and 30s fell until they reached their early 50s, when it stabilized and then slowly rose. The above sleep time change pattern and the newly identified key time points were the same across genders, countries and education levels.

The research team said that the reduction in sleep time in middle age may be due to the demands of parenting, work and life.

Source: China Science Daily

Paper link:

https://www.nature.com/articles/s41467-022-34624-8

Scientists from China and the United States create artificial tissue to restore reproductive function

Recently, a study showed that an artificial tissue developed by researchers from China and the United States can restore the erectile function of damaged penises in pigs, which may bring new treatments for erectile dysfunction.

Erectile dysfunction can result from a variety of causes, including damage to the tunica albuginea . In this study, the artificial tissue mimicked the tunica albuginea, a layer of connective tissue that covers the corpora cavernosa and fills with blood during an erection.

Lesions of the tunica albuginea can be repaired by taking tissue from elsewhere in the body and combining it with a network of proteins and other molecules to create a supportive tissue patch. However, such patches are rejected by the immune system and are not effective in mimicking the tunica albuginea.

To solve this problem, Shi Xuetao of South China University of Technology and his collaborators used isotropic polyvinyl alcohol gel to create a white membrane. It has a curled fiber structure, similar to natural tissue. In subsequent tests, the pigs' penises became erect when injected with saline. Until a month later, the pigs showed no signs of rejecting the artificial tissue.

"This study shows that artificial biomaterials can adequately repair defects with good results," said Anthony Atala of the Wake Forest Institute for Regenerative Medicine in North Carolina. "This technology is promising and deserves further study so that it can be safely transitioned to humans to benefit patients."

Source: China Science Daily

Paper link:

https://www.cell.com/matter/fulltext/S2590-2385(22)00663-4

To help the deaf, scientists invented a high-performance lead-free flexible piezoelectric acoustic sensor

Data from the World Health Organization shows that approximately 430 million people worldwide suffer from hearing loss due to cochlear damage , and improving hearing mainly relies on cochlear implants.

However, traditional cochlear implants have low speech recognition capabilities, and the mismatch between rigid electrodes and soft tissue may lead to problems such as nerve damage and tinnitus. With the development of the Internet of Things and artificial intelligence, research on flexible self-powered cochlear implants has attracted widespread attention.

Piezoelectric materials can be used as favorable candidate materials for future cochlear implants, but mainstream lead-containing piezoelectric materials are incompatible with biomaterials and are not environmentally friendly. The electrical output power of other piezoelectric materials is insufficient to directly stimulate the auditory nerve due to their low acoustic-to-electric conversion performance. Therefore, it is of great significance to manufacture high-performance lead-free flexible piezoelectric acoustic sensors .

Recently, inspired by the outer ear hair cells of the human cochlea, the team reported a direct-writing micro-cone array strategy based on multi-component lead-free perovskite rods at quasi-isotropic phase boundaries.

On the one hand, this strategy utilizes orientation engineering and the quasi-isotropic phase boundary formed between two different orthogonal phases (Amm2 and Pmmm) to significantly improve the effect of stress on the performance of piezoelectric materials and achieve enhanced piezoelectric response; on the other hand , a micro-cone array is introduced on the surface of the piezoelectric film to increase the contact area with the sound waves and enhance the absorption of sound waves, thereby preparing a high-performance flexible piezoelectric acoustic sensor (FPAS).

The sensor shows the characteristics of high sensitivity and wide frequency response , covering commonly used voice frequencies, and has angular sensitivity, which can be used to record sound signals and realize voice recognition and human-computer interaction. FPAS is also waterproof and acid- and alkali-resistant, meeting the requirements of the natural environment for wearable acoustic sensors.

Source: Institute of Chemistry, Chinese Academy of Sciences

Paper link:

https://www.cell.com/matter/fulltext/S2590-2385(22)00654-3

Scientists invent self-healing ionic skin like human skin

Human skin is an important body organ that can sense external mechanical forces, such as pressure, strain, and torsion, through ion transport mechanisms. It also has self-repair capabilities and can restore its original function after external damage.

Inspired by the sensing structure of human skin, scientists have successively reported several ionic skins with ion transport mechanisms that have high anti-interference properties, excellent spatial resolution, and outstanding responses to static and dynamic stimuli.

However, these ionic skins are susceptible to accidental mechanical damage due to continuous wear , resulting in functional disruption or reduced device lifespan. Therefore, self-healing ability similar to human skin is an important property required to restore damaged functions to ensure stability and increase device lifespan.

Recently, a Chinese and Korean research team developed an ultra-sensitive and self-repairing ionic skin . It has the same elasticity as human skin and has the ability to self-repair, and its sensitive tactile function can be restored as the wound heals.

Figure｜Design concept of ionic skin: The action potential stimulation generated by ion dynamics and the bond exchange effect of dynamic disulfide bonds simulate the external force perception and self-healing function of human skin.

They used ionic liquid as the signal transmission medium and filled it with thermoplastic polyurethane material to develop a new type of ion conductor; they used silver nanowires as flexible electrodes and polyurethane as packaging material to assemble them into target ion skin.

Since the chlorine substituents introduced into the polyurethane have a large electronegativity, they have a reversible ion-dipole interaction with the ionic liquid. By changing the reversible ion-dipole interaction between the chlorine substituents and the ionic liquid through mechanical stimulation, the difference between the instantaneous capacitance and the initial capacitance can be effectively increased, thereby improving the sensitivity.

The research results simulated the ion signal transmission system similar to biological tactile cells, controlled the ion distribution inside the ion conductor according to the change of force, and maximized the tactile perception. The research proposed a new concept of ion skin technology that can simultaneously restore wounds and tactile functions, which is expected to be applied to human-machine interfaces in the field of wearable medical care .

Source: Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences

Paper link:

https://www.nature.com/articles/s41467-022-35434-8

Scientists propose fiber-shaped photoelectric artificial synapses to give textiles perception and memory

With the integration of traditional textile industry with electronics, manufacturing, sensing and Internet of Things technologies, ubiquitous fabrics are given higher expectations and more functions, and gradually evolve into a new carrier of artificial intelligence technology. As an important branch of wearable electronics, electronic fabrics have attracted widespread attention in the fields of energy collection/storage, perception, display/interaction and information storage/processing .

As the basic unit of electronic fabrics, one-dimensional functional fibers are lightweight, ultra-soft and multifunctional. They can also be made into breathable textiles through mature weaving technology, which is of great significance to the development of smart fabrics in the future.

In the interaction between humans and the external environment, more than 80% of external information is received through human eyes. Therefore, bionic artificial vision systems show great potential in applications such as human-computer interaction, image recognition, autonomous driving, and low-power optical neuromorphic.

In recent years, bionic visual systems based on optoelectronic artificial synapses have made rapid progress, which can simultaneously perceive electrical signals/optical information and temporarily memorize or even perform preliminary operations on the perceived information. At present, building a wearable artificial visual system with good flexibility and breathability still faces great challenges.

Recently, Li Qingwen, Zhang Qi Chong and other researchers from the Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, proposed and verified the concept of a fibrous optoelectronic artificial synaptic device , which can simultaneously realize a variety of bionic synaptic functions induced by light/electrical signals, including pulse facilitation, long/short-term plasticity, and "learning-consolidation-relearning" behaviors.

Based on the performance of optoelectronic synapses, the researchers successfully woven multiple fiber-like devices into breathable fabrics, enabling flexible fabrics to sense and store simple digital image information.

In order to demonstrate the visual perception and memory functions of textiles based on fiber-shaped optoelectronic artificial synapses, the researchers wove multiple devices into breathable fabrics and constructed photocurrent imaging textiles using photomasks. The fabrics can perceive and remember simple digital optical image information, demonstrating their potential in developing wearable visual memory systems . This work has opened up new avenues for the design and development of flexible functional fibers with integrated perception and memory functions.

Source: Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences

Paper link:

https://www.cell.com/matter/fulltext/S2590-2385(22)00691-9

New method for detecting Helicobacter pylori: 100 times more sensitive than PCR

Helicobacter pylori infection is the main pathogenic factor of chronic gastritis and peptic ulcer, and is closely related to diseases such as gastric cancer and gastric mucosa-associated lymphoid tissue (MALT) lymphoma . Most Helicobacter pylori infected patients can be cured by multi-therapy according to the doctor's advice, but most infected patients have almost no symptoms in the early stage and are easily ignored.

In addition, not all people infected with Helicobacter pylori will develop the disease. Only strains that express cytotoxin-associated protein (CagA) and vacuolating toxin (VacA) are related to gastric inflammation, ulcers and gastric cancer.

Therefore, there is an urgent need for rapid, accurate, highly specific and highly sensitive on-site detection methods in clinical practice to help prevent the spread of highly pathogenic Helicobacter pylori and to monitor and diagnose people who are already sick in real time.

Recently, Li Zhiyuan's team from the Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, proposed a highly sensitive detection method for highly pathogenic Helicobacter pylori strains by combining loop-mediated isothermal amplification (LAMP) with the latest CRISPR/Cas12a technology.

This method only requires testing saliva samples to quickly and accurately detect positive patients infected with the strain . It has been proven to be more sensitive than PCR (100 times) and can quickly obtain test results using a simple water bath at a constant temperature (65°C).

Compared with traditional Helicobacter pylori detection methods, this method is simpler, faster, cheaper, and has higher sensitivity and specificity. It will play an important role in the detection and treatment of highly pathogenic Helicobacter pylori in the general population, as well as in the occurrence and improvement of prognosis of related diseases such as gastritis, gastric ulcer and gastric cancer .

Source: Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences

Paper link:

https://pubmed.ncbi.nlm.nih.gov/36459819/