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Tag: Japan

Researchers make advances in understanding the role of a novel drug in reducing anxiety-like behavior in mice

Posted on by Tokyo University of Science

Anxiety is considered a natural response to stress. However, a state of heightened anxiety, called anxiety disorder, prevents thousands of people from living their best lives. While several underlying mechanisms have been therapeutically targeted, much remains to be discovered about this disorder. In an effort to get closer to unravelling the mechanisms that govern this condition, Japanese researchers have identified a drug that reduces glutamate-induced neurotransmission, involved in anxiety-like behaviour.

For a group of Japanese researchers from Tokyo University of Science and University of Tsukuba, endeavouring in this line of research is not new. In a previous study, they used a drug called KNT-127, which acts by activating specific receptors in the brain, called “delta opioid receptors.” The researchers found KNT-127 to reduce anxiety-like behavior in mice. They found that KNT-127 caused the reduction of an excitatory neurotransmitter, called glutamate, in the extracellular regions of a part of the brain that controls several emotional states, called the “prelimbic subregion of the medial prefrontal cortex” (PL-PFC). The researchers went on to study this phenomenon in a new study published in Biochemical
and Biophysical Research Communications

According to Professor Akiyoshi Saitoh, from the Faculty of Pharmaceutical Sciences, Tokyo University of Science, and corresponding author of this study, there is a good reason to have investigated the glutamate levels specifically in PL-PFC. He says, “The medial prefrontal cortex (mPFC) plays a vital role in the processing of emotional events. It has been shown that activation of the glutamatergic transmission in PL-PFC evoked anxiety-like behavior in rodents.”

Accordingly, Professor Saitoh and his colleagues conducted electrophysiological studies at a single-neuron level in mice. The team measured spontaneous excitatory currents from the glutamate-releasing presynapse region of various important neurons treated with and without KNT-127, in the PL-PFC of mice that had been induced to exhibit anxious behaviour.

For neurons treated with KNT-127, the results showed that the release of glutamate was reduced at the PL-PFC synapses. Since this excitatory neurotransmitter relays information from one neuron to the other, at the synapse region, the corresponding brain activity was also found to be lowered. Interestingly, the team found that KNT-127 treatment made the PL-PFC neurons less excitable. The researchers considered these findings to be a consequence of the anxiolytic effects of KNT-127.

Overall, this study proposes a novel pathway—and a novel drug candidate—that can be targeted for treating anxiety disorder. Commenting on the clinical potential of drugs like KNT-127, Dr. Daisuke Yamada, one of the investigators in the study from Tokyo University of Science, says, “There is a need for the development of new therapeutic agents that have different mechanisms of action from existing drugs. The results of this study are expected to lead to the development of evidence-based antipsychotics with a new mechanism of action, targeting opioid delta receptors.”

Nrf2: The custodian regulating oxidative stress and immunity against Acrylamide toxicity

Posted on by Tokyo University of Science

Acrylamide, which is extensively used in industries, causes peripheral neuropathy or encephalopathy. Now, scientists from Japan examined the response against oxidative stress in acrylamide-induced neurotoxicity and found that nuclear factor erythroid 2-related factor 2 (Nrf2), a master regulator of the immune system and response to oxidative stress, was at the centre of this toxicity. They found that Nrf2 plays a protective role by increasing the expression of protective genes and decreasing that of pro-inflammatory genes.

In a recent study, a team of scientists, led by Prof. Gaku Ichihara from Tokyo University of Science, reported the role of Nrf2 in acrylamide-induced neurotoxicity. Prof. Ichihara
states, “Our study showed that Nrf2 has a protective role against neurologic damage and suggests it is through activation of antioxidant stress genes and suppression of proinflammatory cytokine genes.”

In their study published in the journal Toxicology, Prof. Gaku Ichihara, along with his colleagues Prof. Masayuki Yamamoto from Tohoku University, Prof. Ken Itoh from Hirosaki University, Associate Prof. Seiichiroh Ohsako from The University of Tokyo, and Prof. Sahoko Ichihara from Jichi Medical University, used mice models to study the role of Nrf2 in acrylamide-induced neurotoxicity.

They tested their hypothesis that when Nrf2 gene is removed, the neurotoxic effects of acrylamide will be amplified. For this, they developed “knockout” mice that could not produce Nrf2, and gave the Nrf2-knockout mice and a set of counterpart “wild-type” mice that could produce Nrf2 different concentrations of acrylamide for 4 weeks. Then, they compared the neurotoxicity between both groups of mice using various sensory and motor tests, immunohistochemistry, and protein and gene expression analyses.

The scientists found that the Nrf2-knockout mice had severe neurotoxic effects such as sensory and motor system dysfunction and axonal damage. While these mice produced fewer antioxidants and protective factors in response to acrylamide, they also showed enhanced release of pro-inflammatory chemicals, called “cytokines,” in the brain, which can potentially cause additional damage. Additionally, as different doses were given to the mice, the scientists also determined that the neurotoxicity was dose-dependent.

Previous studies have established the role of Nrf2 as a master regulator of protective genes but this study explained the specific mechanisms of immune response to acrylamide-induced toxicity, with Nrf2 at the center of it all. As Prof. Ichihara states, “The results document the first known morphological and neuro-functional evidence of the regulatory role of Nrf2 in acrylamide-induced neurotoxic effects in mice.”

The findings of this study are also immensely valuable in the field of disease biology, as recent studies have shown a link between air pollution and Alzheimer’s disease. Since the air contains other acrylamide-like chemical pollutants with similar neurotoxic effects, the study’s findings could prove useful in the prevention of Alzheimer’s disease.

Prof. Ichihara and his team’s study is certainly a timely one, as reports of acrylamide intoxication are on the rise and further research is required to better understand the specific mechanisms by which the body protects itself from harm.

New screening method could lead to microbe-based replacements for chemical pesticide replacement

Posted on by Tokyo University of Science

Some nonpathogenic microorganisms can stimulate plant immune responses without
damaging the plants, which allows them to act like plant vaccines, but screening microorganisms for such properties has traditionally been time-consuming and expensive.

Associate Professor Toshiki Furuya and Professor Kazuyuki Kuchitsu of Tokyo University of Science and their colleagues decided to develop a screening strategy involving cultured
plant cells. A description of their method appears in a paper recently published in Scientific Reports.

The first step in this screening strategy involves incubating the candidate microorganism together with BY-2 cells, which are tobacco plant cells known for their rapid and stable growth rates. The next step is to treat the BY-2 cells with cryptogein, which is a protein secreted by fungus-like pathogenic microorganisms that can elicit immune responses from tobacco plants.

A key part of the cryptogein-induced immune responses is the production of a class of chemicals called reactive oxygen species (ROS), and scientists can easily measure cryptogein-induced ROS production and use it as a metric for evaluating the effects of the nonpathogenic microorganisms.

To put it simply, an effective pretreatment agent will increase the BY-2 cells’ ROS production levels (i.e., cause the cells to exhibit stronger immune system activation) in response to cryptogein exposure.

To test the practicability of their screening strategy, Dr. Furuya and his colleagues used the strategy on 29 bacterial strains isolated from the interior of the Japanese mustard spinach plant (Brassica rapa var. perviridis), and they found that 8 strains boosted cryptogein-induced ROS production.

They then further tested those 8 strains by applying them to the root tips of seedlings from the Arabidopsis genus, which contains species commonly used as model organisms for studies of plant biology. Interestingly, 2 of the 8 tested strains induced whole-plant resistance to bacterial pathogens.

Based on the proof-of-concept findings concerning those 2 bacterial strains, Dr Furuya proudly notes that his team’s screening method “can streamline the acquisition of microorganisms that activate the immune system of plants.”

When asked how he envisions the screening method affecting agricultural practices, he explains that he expects his team’s screening system “to be a technology that contributes to the practical application and spread of microbial alternatives to chemical pesticides.”

In time, the novel screening method developed by Dr Furuya and team may make it significantly easier for crop scientists to create greener agricultural methods that rely on the defence mechanisms that plants themselves have evolved over millions of years.

Scientists find a way to use visible light to decompose CO2 with high efficiency

Posted on by NITech

To tackle the challenge of global warming, scientists have been looking into green and sustainable methods of breaking down carbon dioxide in emissions and in the atmosphere. Now, a group of researchers from Nagoya Institute of Technology, Japan, have developed a novel, easy to synthesize composite compound that enables the efficient use of solar energy to reduce carbon dioxide, taking us one step closer to achieving a green economy.

A team of scientists led by Drs. Shinji Kawasaki and Yosuke Ishii from Nagoya Institute of Technology, Japan, has been at the forefront of efforts to achieve efficient solar-energy-assisted CO2 reduction. Their recent breakthrough is published in Nature’s Scientific
Reports.

Their research began with the need to solve the limited applicability problem of silver iodate (AgIO3), a photocatalyst that has attracted considerable attention for being useful for the CO2 reduction reaction. The problem is that AgIO3 needs much higher energy than that which visible light can provide to function as an efficient photocatalyst, and visible light is the majority of solar
radiation.

Scientists have attempted to work around this efficiency problem by combining AgIO3 with
silver iodide (AgI), which can efficiently absorb and utilize visible light. However, AgIO3–AgI composites have complicated synthesis processes, making their large-scale manufacturing impractical. Further, they don’t have structures that offer efficient pathways for the transfer of photoexcited electrons (electrons energized by light absorption) from AgI to AgIO3, which is key to the composite’s catalytic activity.

“We have now developed a new photocatalyst that incorporates single-walled carbon nanotubes (SWCNTs) with AgIO3 and AgI to form a three-component composite catalyst,” says Dr. Kawasaki, “The role of the SWCNTs is multimodal. It solves both the synthesis and
the electron transfer pathway problems.”

The three-component composite’s synthesis process is simple and involves just two steps: 1. Encapsulating iodine molecules within the SWCNT using an electrochemical oxidation method; and 2. Preparing the composite by immersing the resultant of the previous step in an aqueous solution of silver nitrate (AgNO3).

Spectroscopic observations using the composite showed that during the synthesis process, the encapsulated iodine molecules received charge from the SWCNT and converted into specific ions. These then reacted with AgNO3 to form AgI and AgIO3 microcrystals, which, due to the initial positions of the encapsulated iodine molecules, were deposited on all the SWCNTs uniformly. Experimental analysis with simulated solar light revealed that the SWCNTs also acted as the conductive pathway through which photoexcited electrons moved from AgI to AgIO3,  enabling the efficient reduction of CO2
to carbon monoxide (CO).

The incorporation of SWCNTs also allowed for the composite dispersion to be easily spray-coated on a thin film polymer to yield flexible photocatalytic electrodes that are versatile and can be used in various applications.

Dr Ishii is hopeful about their photocatalyst’s potential. “It can make the solar reduction of industrial CO2 emissions and atmospheric CO2 an easy-to-scale and sustainable renewable energy-based solution tackling global warming and climate change, making people’s lives safer and healthier,” he says.

The next step, the team says, is to explore the possibility of using their photocatalyst for solar hydrogen generation. Perhaps, humanity’s future is bright after all!

Researchers from Japan develop a model to explore the dynamics of movement in cheetahs

Posted on by NITech

In a new study, a team of researchers from Japan propose and validate an analytical model for studying cheetah galloping by comparing its predictions with cheetah data. While improving upon the current understanding of cheetah’s locomotion, their findings pave the way for designing legged robots!

“All animal running constitutes a flight phase and a stance phase, with different dynamics governing each phase,” explains Dr. Tomoya Kamimura from Nagoya Institute of Technology, Japan, who specializes in intelligent mechanics and locomotion.

During the flight phase, all feet are in the air and the center of mass (COM) of the whole body exhibits ballistic motion. Conversely, during the stance phase, the body receives ground reaction forces through the feet.

“Due to such complex and hybrid dynamics, observations can only get us so far in unravelling the mechanisms underlying the running dynamics of animals,” Dr. Kamimura says.

Consequently, researchers have turned to computer modelling to gain a better dynamic perspective of the animal gait and spine movement during running and have had remarkable success using fairly simple models. However, few studies so far have explored the types of flight and spine motion during galloping (as seen in a cheetah).

Against this backdrop, Dr. Kamimura and his colleagues from Japan have now addressed this issue in a recent study published in Scientific Reports, using a simple model emulating vertical and spine movement.

The team, in their study, employed a two-dimensional model comprising two rigid bodies and two massless bars (representing the cheetah’s legs), with the bodies connected by a joint to replicate the bending motion of the spine and a torsional spring. Additionally, they assumed an anterior-posterior symmetry, assigning identical dynamical roles to the fore and hind legs.

By solving the simplified equations of motion governing this model, the team obtained six possible periodic solutions, with two of them resembling two different flight types
(like cheetah galloping) and four, only one flight type (unlike cheetah galloping), based on the criteria related to the ground reaction forces provided by the solutions themselves. Researchers then verified these criteria with measured cheetah data, revealing that cheetah galloping in the real world indeed satisfied the criterion for two flight types through spine bending.

Additionally, the periodic solutions also revealed that horse galloping only involves gathered flight due to restricted spine motion, suggesting that the additional extended flight in
cheetahs combined with spine bending allowed them to achieve such great speeds!

“While the mechanism underlying this difference in flight types between animal species still remains unclear, our findings extend the understanding of the dynamic mechanisms underlying high-speed locomotion in cheetahs. Furthermore, they can be applied to the mechanical and control design of legged robots in the future,” speculates an optimistic Dr Kamimura.

Scientists find drug duo that may cure COVID-19

Posted on by Tokyo University of Science

While preventative care for COVID-19 has made much noise (with vaccines having rolled out in most countries), the soaring infection rates indicate the need for effective treatments. Using cultured cells to study SARS-CoV-2 infections, researchers at the Tokyo University of Science and other institutions have discovered that the drugs cepharanthine and nelfinavir are effective at combating the virus, with the former preventing the virus from entering cells and the latter preventing the virus from replicating.

A team of researchers based in Japan, the US, and the UK launched a project to develop effective therapeutics. This team included several researchers based at Tokyo University of Science: Visiting Professor Koichi Watashi, Dr. Hirofumi Ohashi, Professor Shin Aoki, Professor Kouji Kuramochi, and Assistant Professor Tomohiro Tanaka. Their goal was clear and simple: finding a cure for COVID-19.

To achieve this goal, the researchers first established an experimental system for screening drugs that may help to control infections. This system used a type of cells called VeroE6/TMPRSS2 cells, which were manipulated to efficiently be infected with and produce SARS-CoV-2. “To determine whether a drug of interest could help combat infection by SARS-CoV-2, we simply had to expose VeroE6/TMPRSS2 cells to both the drug and SARS-CoV-2 and then observe whether the drug’s presence served to hinder the virus’s efforts to infect cells,” explains Professor Watashi.

The researchers used this experimental system to screen a panel of drugs that are already approved for clinical use, including drugs like remdesivir and chloroquine that have already being approved or are being trialed as treatments for COVID-19. In an exciting outcome, the researchers found two drugs that provided effective SARS-CoV-2 suppression: cepharanthine, which is used to treat inflammation, and nelfinavir, which is approved for the treatment of HIV infection.

Cepharanthine inhibited the entry of the virus into cells by preventing the virus from binding to a protein on the cell membrane, which it uses as a gateway. In contrast, nelfinavir worked to prevent the virus from replicating inside the cell by inhibiting a protein that the virus relies on for replication. Given that these drugs have distinct antiviral mechanisms, using both of them together could be especially effective for patients, with computational models predicting that combined cepharanthine/nelfinavir therapy can hasten the clearance of SARS-CoV-2 from a patient’s lungs by as few as 4.9 days.

So, does this mean we will be seeing these new drugs in COVID-19 treatment centers? Of course, the drug duo isn’t ready to be rolled out into healthcare systems just yet. These findings justify further research into the clinical potential of cepharanthine/nelfinavir therapy, and only following this can we say for sure that it is useful and helpful.

Nevertheless, given the ongoing nature of the COVID-19 pandemic and the ever-increasing death toll, the development of cepharanthine/nelfinavir therapy may provide clinicians and patients with a much-needed new treatment option.

New research model indicates possibility of economic growth in a zero-emission society

Posted on by Tokyo University of Science

With increasing public awareness of crises associated with degraded environments and mounting pressure to act, governments worldwide have begun to examine environmentally sustainable policies. However, there are many questions about whether enacting these policies will negatively affect economic growth. Now, a modelling study conducted by researchers from Tokyo University of Science and The Shoko Chukin Bank, Japan, published in the Journal of Cleaner Production, shows that it is possible to achieve economic growth
simultaneously with environmental preservation.

“There are existing models that look at how economies fluctuate under various conditions, such as differing environmental quality or tax rates, but these models haven’t examined the effects of implementing the kindergarten rule,” Prof. Hideo Noda, the study’s lead author, explained.

“So we thought it was important to extend the model and include a condition where the hypothetical society spends a part of its GDP to achieve zero emissions. Looking at emissions is also more tangible and easier to grasp than a vaguer concept of ‘environmental quality.”

The researchers used an economic model that allows for movement back and forth between two stages: a no-innovation phase and an innovation phase. The key to this model is the importance of innovation; previous models that focus on the environment and the economy did not account for innovation (e.g., research and development) as a major driver of economic growth in most developed nations. Acknowledging this connection is essential for improving our knowledge regarding how environmental problems and economic growth are linked.

When researchers included rules for the zero-emission society, the model indicated that it was compatible with economic growth (i.e., a sustained GDP growth), despite a portion of the GDP being dedicated to reducing pollution. For this to work, however, the model says that the GDP needs to be above a certain level.

Additionally, the amount of GDP allocated to lowering pollution must be flexible. Researchers also observed that under the no innovation phase, GDP growth is higher and the amount spent on pollution reduction decreases faster. In contrast, under the innovation phase, GDP growth is lower and the decrease in the amount spent combating pollution is also slower.

According to Prof. Noda, this work provides the important theoretical groundwork for policy, because currently, the relationship between zero emissions and economic growth isn’t well understood. “Yet, this topic is extremely relevant to any policy push for sustainability—for example, one section of the UN’s Sustainable Development Goals explicitly focuses on economic growth,” he explains.

“Our model should help persuade the leaders of some countries that it is feasible to reduce emissions without tanking the economy.”

That, Prof. Noda hopes, may in turn make leaders more eager to implement the changes that are urgently needed to address global environmental crises like climate change.

Mutation linked to autism impairs oxytocin-mediated social behavior

Posted on by Tokyo University of Science

A rare mutation in the Caps2 gene, which encodes a protein that regulates the release of brain chemicals called neurotransmitters, has also been linked with autism spectrum disorders. Now, researchers at the Tokyo University of Science report that Caps2 mutations in mice limit the release of oxytocin (a hormone that regulates social behaviour), causing diminished sociality in these animals. These findings may help researchers understand the neurobiology of autism and develop effective treatments for it.

Autism spectrum disorder is a neurodevelopmental condition involving impaired social abilities, and this makes it a fascinating subject for neuroscientists like Prof. Teiichi Furuichi of the Tokyo University of Science who study the neuroscience of social behaviour. Professor Furuichi and his colleagues have previously worked on developing mouse models of autism to unravel the condition’s neurochemical mechanisms.

In a paper recently published in the prestigious Journal of Neuroscience, they provide evidence that a genetic mutation associated with autism can impair the release of a peptide called oxytocin that plays an important role in regulating social behaviour. This finding promises to broaden our understanding of the neurobiology of social behaviour.

The gene that Prof. Furuichi’s team chose to study is Caps2, which encodes a protein called Ca2+-dependent activator protein for secretion 2 (CAPS2) that regulates the release of brain chemicals (or “neurotransmitters”). Previous studies have shown that CAPS2 deficiencies in mice cause behavioral impairments such as reduced sociality, increased anxiety, and disrupted circadian rhythms.

Furthermore, a study of Japanese patients with autism spectrum disorder revealed that some of them had Caps2 mutations that adversely affect the CAPS2 protein’s functions. Prof. Furuichi and his colleagues had previously discovered that the CAPS2 protein is expressed in neurons in the hypothalamus and pituitary gland that release the neuropeptide oxytocin. This information formed the basis of their recent study.

As Prof. Furuichi explains, “We hypothesized that CAPS2 deficiencies in mice should alter oxytocin release, which should in turn result in impaired social behavior.”

To test this hypothesis, researchers Shuhei Fujima, Graduate Student at Tokyo University of Science; Yoshitake Sano, Junior Associate Professor at Tokyo University of Science; Yo Shinoda, Associate Professor at Tokyo University of Pharmacy and Life Sciences; Tetsushi Sadakata, Associate Professor in Gunma University; Manabu Abe, Associate Professor at Niigata University; and Kenji Sakimura, a Fellow of Niigata University, among others, led by Prof. Furuichi conducted a series of experiments involving mice that carried genetic alterations that prevented them from expressing the CAPS2 protein.

These mice had lower-than-normal oxytocin levels in their blood but higher-than-normal oxytocin levels in the hypothalamus and pituitary gland. The researchers interpreted this finding as evidence that CAPS2 deficiencies impede the normal release of oxytocin from these brain regions into the bloodstream.

Unsurprisingly, the reduced bloodstream levels of oxytocin had clear behavioral effects. When placed inside a rectangular box, the oxytocin neuron-specific CAPS2-deficient mice were unwilling to spend much time in the centre of the box, and the researchers interpreted this as evidence of increased anxiety about the risk of a predator attacking them.

The CAPS2-deficient mice also exhibited diminished willingness to engage in social
interactions when introduced to unfamiliar mice. Interestingly, spraying an oxytocin solution into the noses of the CAPS2-deficient mice acted to restore their willingness to socially interact with unfamiliar mice.

Based on these findings, Prof. Furuichi and his colleagues conclude that the CAPS2 protein plays a critical role in facilitating the release of peripheral oxytocin into the bloodstream. They similarly suggest that CAPS2 is also involved in the release of central oxytocin into the brain regions relating to the control of sociality. Given the key role that oxytocin plays in regulating social behaviours, this could help to explain how mutations in the Caps2 gene
could lead to atypical patterns of social behaviour in persons with an autism spectrum disorder.

When asked about the social significance of his team’s work, Professor Furuichi remarks, “We believe that this research, although basic, is an important achievement that will contribute to the development of tools for the early molecular diagnosis and effective treatment of autism spectrum disorder.”

Given the relatively high prevalence of autism and how extremely disabling severe cases can be, the development of effective treatments would have major benefits for people with autism and society as a whole.

Mineral found in human bone can help fight toxic organic compounds

Posted on by NITech

Many industrial processes emit volatile organic compounds (VOCs) that are hazardous to human health. In a new study, scientists from NITech, Japan, tailor the catalytic activity of hydroxyapatite, a mineral contained in human bones, using mechanical stress. This method was inexpensive and resulted in a 100% VOC conversion, potentially opening doors to effective climate control.

A team of scientists led by Prof. Takashi Shirai from Nagoya Institute of Technology (NITech), Japan, reported a complete catalytic decomposition of VOC using an inorganic compound called “hydroxyapatite” (HAp), a naturally occurring form of the mineral calcium phosphate that makes up most of the human bone structure.

“HAp is made of elements abundant in nature, is non-toxic and exhibits high biocompatibility. Our results, thus, opened up a new possibility for designing cheap, noble-metal-free catalysts for VOC control,” says Prof. Shirai. 

In a new study published in Scientific Reports, Prof. Shirai and his colleague Yunzi Xin from NITech now take things further by tailoring the “active surface” of HAp using a mechanochemical treatment under ambient conditions that leads to a highly efficient catalytic oxidation of VOC with 100% conversion to harmless compounds.

Specifically, they mixed initial HAp with ceramic balls in a vessel and conducted “planetary ball milling” at room temperature and ambient pressure. This essentially altered the chemical structure of HAp and allowed for its selective tailoring by simply changing the ball size.

By using different ball sizes (3, 10, and 15 mm) to systematically vary the morphology, crystallinity, surface defects/oxygen vacancy, acidity/basicity, and VOC affinity of HAps, the
scientists carried out their characterization using various techniques such as scanning electron microscopy, powder X-ray diffraction, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, electron spin resonance analysis, surface acidity/basicity evaluation, and gas-flowing diffuse reflectance infrared Fourier transform spectroscopy. 

They observed a predominance of oxygen vacancy formation in the PO43- (triply charged
PO4) site along with an enhanced basic site population caused by selective mechanochemical activation of the c-plane (plane perpendicular to the symmetry axis) of the hexagonal HAp crystal and attributed it to the excellent catalytic conversion of VOC to CO2/CO. 

Moreover, they found that HAps treated with 3 mm balls showed superior catalytic activity over that treated with 10- and 15-mm balls, even though larger balls caused more defects and basicity. By looking at the surface absorption of a VOC, ethyl acetate, scientists attributed this anomaly to the inhibited absorption of ethyl acetate in HAp treated with larger balls, leading to suppressed catalysis. 

The results have excited scientists about the future prospects of HAps. “We expect that our catalyst will contribute significantly to VOC controlling and environmental cleaning all over the world by next decade, achieving the sustainable goals of clean air and water, affordable energy, and climate action,” comments Prof. Shirai, excited. 

Correcting motion blur in single-photon images

Posted on by Tokyo University of Science

At Tokyo University of Science, Japan, Professor Takayuki Hamamoto has been leading a research team focused on taking the capabilities of single-photon imaging further. In the latest study by Professor Hamamoto and his team, which was published in IEEE Access, they developed a highly effective algorithm to fix the blurring caused by motion in the imaged objects, as well as the common blurring of the entire image such as that caused by the shaking of the camera.

Their approach addresses many limitations of existing deblurring techniques for single-photon imaging, which produce low-quality pictures when multiple objects in the scene
are moving at different speeds and dynamically overlapping each other.

Instead of adjusting the entire image according to the estimated motion of a single object or on the basis of spatial regions where the object is considered to be moving, the proposed method employs a more versatile strategy.

First, a motion estimation algorithm tracks the movement of individual pixels through statistical evaluations on how bit values change over time (over different bit planes). In this way, as demonstrated experimentally by the researchers, the motion of individual objects can be accurately estimated.

“Our tests show that the proposed motion estimation technique produced results with errors of less than one pixel, even in dark conditions with few incident photons,” remarks Prof. Hamamoto.

The team then developed a deblurring algorithm that uses the results of the motion estimation step. This second algorithm groups pixels with a similar motion together, thereby identifying in each bit plane separate objects moving at different speeds.

This allows for deblurring each region of the image independently according to the motions of objects that pass through it. Using simulations, the researchers showed that their strategy produced very crisp and high-quality images, even in low-light dynamic scenes crowded with objects coursing at disparate velocities.

Overall, the results of this study aptly showcase how greatly single-photon imaging can be improved if one gets down to developing effective image processing techniques.

“Methods for obtaining crisp images in photon-limited situations would be useful in several fields, including medicine, security, and science. Our approach will hopefully lead to new technology for high-quality imaging in dark environments, like outer space, and super-slow recording that will far exceed the capabilities of today’s fastest cameras,” says Prof. Hamamoto. He also states that even consumer-level cameras might timely benefit from progress in single-photon imaging.