Tag Archives: brain

A self-powered heart monitor taped to the skin

Scientists in Japan have developed a human-friendly, ultra-flexible organic sensor powered by sunlight, which acts as a self-powered heart monitor. Previously, they developed a flexible photovoltaic cell that could be incorporated into textiles. In this study, they directly integrated a sensory device, called an organic electrochemical transistor—a type of electronic device that can be used to measure a variety of biological functions—into a flexible organic solar cell. Using it, they were then able to measure the heartbeats of rats and humans under bright light conditions.

Self-powered devices that can be fit directly on human skin or tissue have great potential for medical applications. They could be used as physiological sensors for the real-time  or the real-time monitoring of heart or brain function in the human body. However, practical realization has been impractical due to the bulkiness of batteries and insufficient power supply, or due to noise interference from the electrical supply, impeding conformability and long-term operation.

The key requirement for such devices is a stable and adequate energy supply. A key advance in this study, published in Nature, is the use of a nano-grating surface on the light absorbers of the solar cell, allowing for high photo-conversion efficiency (PCE) and light angle independency. Thanks to this, the researchers were able to achieve a PCE of 10.5 percent and a high power-per-weight ratio of 11.46 watts per gram, approaching the “magic number” of 15 percent that will make organic photovoltaics competitive with their silicon-based counterparts.

To demonstrate a practical application, sensory devices called organic electrochemical transistors were integrated with organic solar cells on an ultra-thin (1 μm) substrate, to allow the self-powered detection of heartbeats either on the skin or to record electrocardiographic (ECG) signals directly on the heart of a rat. They found that the device worked well at a lighting level of 10,000 lux, which is equivalent to the light seen when one is in the shade on a clear sunny day, and experienced less noise than similar devices connected to a battery, presumably because of the lack of electric wires.

According to Kenjiro Fukuda of the RIKEN Center for Emergent Matter Science, “This is a nice step forward in the quest to make self-powered medical monitoring devices that can be placed on human tissue. There are some important remaining tasks, such as the development of flexible power storage devices, and we will continue to collaborate with other groups to produce practical devices. Importantly, for the current experiments we worked on the analog part of our device, which powers the device and conducts the measurement. There is also a digital silicon-based portion, for the transmission of data, and further work in that area will also help to make such devices practical.

The research was carried out by RIKEN in collaboration with researchers from the University of Tokyo.

Source: http://www.riken.jp/

How To Recreate Memories Of Faces From Brain Data

A new technique developed by neuroscientists at the University of Toronto can reconstruct images of what people perceive based on their brain activity. The technique developed by Dan Nemrodov, a postdoctoral fellow in Assistant Professor Adrian Nestor’s lab at U of T Scarborough, is able to digitally reconstruct images seen by test subjects based on electroencephalography (EEG) data.

CLICK ON THE IMAGE TO ENJOY THE VIDEO

When we see something, our brain creates a mental percept, which is essentially a mental impression of that thing. We were able to capture this percept using EEG to get a direct illustration of what’s happening in the brain during this process,” says Nemrodov.

For the study, test subjects hooked up to EEG equipment were shown images of faces. Their brain activity was recorded and then used to digitally recreate the image in the subject’s mind using a technique based on machine learning algorithms. It’s not the first time researchers have been able to reconstruct images based on visual stimuli using neuroimaging techniques. The current method was pioneered by Nestor, who successfully reconstructed facial images from functional magnetic resonance imaging (fMRI) data in the past, but this is the first time EEG has been used.

Source: https://www.reuters.com/
A
ND
https://www.utoronto.ca/

Breakthrough In The Fight Against Alzheimer’s

Eisai Co.,  a company located in Tokyo, and Biogen Inc. in Cambridge, United States, announced positive topline results from the Phase II study with BAN2401, an anti-amyloid beta protofibril antibody, in 856 patients with early Alzheimer’s disease. The study achieved statistical significance on key predefined endpoints evaluating efficacy at 18 months on slowing progression in Alzheimer’s Disease Composite Score (ADCOMS) and on reduction of amyloid accumulated in the brain as measured using amyloid-PET (positron emission tomography).

Study 201  is a placebo-controlled, double-blind, parallel-group, randomized study in 856 patients with mild cognitive impairment (MCI) due to Alzheimer’s disease (AD) or mild Alzheimer’s dementia (collectively known as early Alzheimer’s disease) with confirmed amyloid pathology in the brain. Efficacy was evaluated at 18 months by predefined conventional statistics on ADCOMS, which combines items from the Alzheimer’s Disease Assessment Scalecognitive subscale (ADAS-Cog), the Clinical Dementia Rating Sum of Boxes (CDR-SB) scale and the Mini-Mental State Examination (MMSE) to enable sensitive detection of changes in early AD symptoms. Patients were randomized to five dose regimens, 2.5 mg/kg biweekly, 5 mg/kg monthly, 5 mg/kg biweekly, 10 mg/kg monthly and 10 mg/kg biweekly, or placebo.

Topline results of the final analysis of the study demonstrated a statistically significant slowing of disease progression on the key clinical endpoint (ADCOMS) after 18 months of treatment in patients receiving the highest treatment dose (10 mg/kg biweekly) as compared to placebo. Results of amyloid PET analyses at 18 months, including reduction in amyloid PET standardized uptake value ratio (SUVR) and amyloid PET image visual read of subjects converting from positive to negative for amyloid in the brain, were also statistically significant at this dose. Dose-dependent changes from baseline were observed across the PET results and the clinical endpoints. Further, the highest treatment dose of BAN2401 began to show statistically significant clinical benefit as measured by ADCOMS as early as 6 months including at 12 months.

Source: https://www.eisai.com/

Brain function partly replicated by nanomaterials

The brain requires surprisingly little energy to adapt to the environment to learn, make ambiguous recognitions, have high recognition ability and intelligence, and perform complex information processing.

The two key features of neural circuits are “learning ability of synapses” and “nerve impulses or spikes.” As brain science progresses, brain structure has been gradually clarified, but it is too complicated to completely emulate. Scientists have tried to replicate brain function by using simplified neuromorphic circuits and devices that emulate a part of the brain’s mechanisms.

Spontaneous spikes being similar to nerve impulses of neurons was generated from a POM/CNT complexed network

In developing neuromorphic chips to artificially replicate the circuits that mimic brain structure and function, the functions of generation and transmission of spontaneous spikes that mimic nerve impulses (spikes) have not yet been fully utilized.

A joint group of researchers from Kyushu Institute of Technology and Osaka University studied current rectification control in junctions of various molecules and particles absorbed on single-walled carbon nanotube (SWNT), using conductive atomic force microscopy (C -AFM), and discovered that a negative differential resistance was produced in polyoxometalate (POM) molecules absorbed on SWNT. This suggests that an unstable dynamic non-equilibrium state occurs in molecular junctions.

In addition, the researchers created extremely dense, random SWNT/POM network molecular neuromorphic devices, generating spontaneous spikes similar to nerve impulses of neurons.

POM consists of metal atoms and oxygen atoms to form a 3-dimensional framework. Unlike ordinary organic molecules, POM can store charges in a single molecule. In this study, it was thought that negative differential resistance and spike generation from the network were caused by nonequilibrium charge dynamics in molecular junctions in the network.

Thus, the joint research group led by Megumi Akai-Kasaya conducted simulation calculations of the random molecular network model complexed with POM molecules, which are able to store electric charges, replicating spikes generated from the random molecular network.  They also demonstrated that this molecular model would very likely become a component of reservoir computing devices. Reservoir computing is anticipated as next-generation artificial intelligence (AI). Their research results were published in Nature Communications.

The significance of our study is that a portion of brain function was replicated by nano-molecular materials. We demonstrated the possibility that the random molecular network itself can become neuromorphic AI,” says lead author Hirofumi Tanaka.

Source: http://resou.osaka-u.ac.jp/

Compound to treat Alzheimer’s shows promise in mice

Researchers at The Rockefeller University in New York have made a component, RU-505, which can be used to slow the progression of Alzheimer’s disease in mice.

CLICK ON THE IMAGE TO ENJOY THE VIDEO

The investigations build on Alzheimer’s studies conducted in Rockefeller University labs, particularly research focused on how the cells of the brain process the amyloid precursor protein (APP). Faulty regulation of APP processing — in which APP is chopped into smaller pieces during normal brain cell metabolism — is believed to contribute to the development of Alzheimer’s. Scientists in the Fisher Center work on understanding why APP can sometimes produce protein fragments that are safely secreted from the cell and at other times produce a protein called amyloid-ß, a major component of the brain plaques that are a hallmark of Alzheimer’s disease.

Source: https://www.rockefeller.edu/

How To Deliver Drug Deep In The Brain

By learning how rabies virus travels in the brain, Anti-Parkinson’s drug can be delivered deep in the brain where currently the drugs are not able to reachRabies virus has the capability to trick the nervous system and cross the blood brain barrier. This trick could be used for drug design. Glycoprotein 29 present on the rabies virus is attached to a nanoparticle stuffed full of deferoxamine ( Anti-Parkinson’s medication) and injected into the brain to trick the brain.

Rabies virus may have some tricks to bypass the blood brain barrier, this trick can be used to treat disease that require drugs to effectively cross the blood brain barrier, finds a new study.

The researchers can now exploit rabies viruses machinery to deliver a Parkinson’s disease medication directly to the brain. Upon injection the nanoparticles grab excess iron and relieve symptoms. While the common cause of Parkinson’s disease is unknown, it has been proved that accumulation of iron in neurons is one of the commonest features of Parkinson’s disease.

Deferoxamine is a metal-grabbing compound and sop up the excess iron in patients. But a large quantity of this drug needs to reach the brain in order for them work.
To usher deferoxamine into the brain, the researchers Yan-Zhong Chang, Xin Lou, Guangjun Nie took advantage of a key part of the rabies virusGlycoprotein 29.
When they injected this iron-grabbing nanoparticles into mouse models of Parkinson’s disease, the iron levels dropped and this reduced brain damage caused by Parkinson’s disease.

The findings of this study is published in the ACS Nano journal.

Source: https://www.acs.org/