Gilded fuel cells boost electric car efficiency

To make modern-day fuel cells less expensive and more powerful, a team led by Johns Hopkins chemical engineers has drawn inspiration from the ancient Egyptian tradition of gilding. Egyptian artists at the time of King Tutankhamun often covered cheaper metals (copper, for instance) with a thin layer of a gleaming precious metal such as gold to create extravagant masks and jewelry. In a modern-day twist, the Johns Hopkins-led researchers have applied a tiny coating of costly platinum just one nanometer thick—100,000 times thinner than a human hair—to a core of much cheaper cobalt. This microscopic marriage could become a crucial catalyst in new fuel cells that generate electric current to power cars and other machines.

The new fuel cell design would save money because it would require far less platinum, a very rare and expensive metal that is commonly used as a catalyst in present-day fuel-cell electric cars. The researchers, who published their work earlier this year in Nano Letters, say that by making electric cars more affordable, this innovation could curb the emission of carbon dioxide and other pollutants from gasoline– or diesel-powered vehicles.

This technique could accelerate our launch out of the fossil fuel era,” said Chao Wang, a Johns Hopkins assistant professor in the Department of Chemical and Biomolecular Engineering and senior author of the study. “It will not only reduce the cost of fuel cells. It will also improve the energy efficiency and power performance of clean electric vehicles powered by hydrogen.”

In their journal article, the authors tipped their hats to the ancient Egyptian artisans who used a similar plating technique to give copper masks and other metallic works of art a lustrous final coat of silver or gold.The idea,” Wang said, “is to put a little bit of the precious treasure on top of the cheap stuff.”

He pointed out that platinum, frequently used in jewelry, also is a critical material in modern industry. It catalyzes essential reactions in activities including petroleum processing, petrochemical synthesis, and emission control in combustion vehicles, and is used in fuel cells. But, he said, platinum’s high cost and limited availability have made its use in clean energy technologies largely impractical—until now.

Source: https://hub.jhu.edu/

Neuron Triggers Insulin

Research led by a Johns Hopkins University biologist demonstrates the workings of a biochemical pathway that helps control glucose in the bloodstream, a development that could potentially lead to treatments for diabetes. In a paper published in the current issue of Developmental Cell, Jessica Houtz, a graduate student working with Rejji Kuruvilla in the Department of Biology at Johns Hopkins, shows that a protein that regulates the development of nerve cells also plays a role in prompting cells in the pancreas to release insulin, a hormone that helps to maintain a normal level of blood sugar.

jessica_houtzCLICK ON THE IMAGE TO ENJOY THE VIDEO
Kuruvilla worked on the project with Johns Hopkins colleagues, Houtz who is the lead author, and Philip Borden and Alexis Ceasrine, all doctoral students in the biology department. Also taking part was Liliana Minichiello of the Department of Pharmacology at the University of Oxford.

The research is potentially relevant to type-2 diabetes, the most common form of the disease, affecting nearly one in ten Americans. With this form of the condition, which can appear at any time of life, the body makes insulin, but is either not releasing enough of it or not using the regulatory chemical efficiently to control blood sugar. In type-1 diabetes, which appears in childhood, an immune response gone awry destroys the body’s ability to produce insulin altogether.

The research on insulin represents a detour for Kuruvilla, whose work has focused on development of the peripheral nervous system. She has studied a group of proteins called neurotrophins, and in particular nerve growth factor [NGF]. These proteins nurture the growth of neurons, the cells of the nervous system.

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It has been known for some time that neurons and the pancreatic beta cells, or β-cells, that reside in clusters called islets of Langerhans and produce insulin, have many similarities in molecular makeup and signaling receptors. Receptors are proteins on cell surfaces that respond to particular chemicals and have critical roles in biochemical pathways. Both neurons and pancreatic β-cells have the receptors for neurotrophins.

This project was sparked by seeing NGF receptors present in beta-cells,” said Kuruvilla. The question was, she said: “what are these receptors doing outside the nervous system?”

Turns out that NGF performs a function in the mature pancreas that has nothing to do with supporting neurons. Specifically, the research team traced a chain of biochemical signals showing that elevated blood glucose causes NGF to be released from blood vessels in the pancreas, and that the NGF signal then prompts pancreatic β-cells to relax their rigid cytoskeletal structure, releasing insulin granules into the blood stream. Although β-cells also make NGF, Kuruvilla and her team found that it was the NGF released from the blood vessels that is needed for insulin secretion.

Using genetic manipulation in mice and drugs to block NGF signaling in β-cells, they were able to disrupt distinct elements of this signaling sequence, to show that this classical neuronal pathway is necessary to enhance insulin secretion and glucose tolerance in mice. Importantly, Kuruvilla and colleagues found that NGF’s ability to enhance insulin secretion in response to high glucose also occurs in human β-cells.

It is not yet clear how this system is affected in people with diabetes. “We are very interested in knowing whether aspects of this pathway are disrupted in pre-diabetic individuals,” said Kuruvilla. It would be of interest to determine if NGF or small molecules that bind and activate NGF receptors in the pancreas could be of potential use in the treatment of type-2 diabetes.

Source: http://releases.jhu.edu/

How To Grow Mini Human Brains

A*STAR’s Scientists in Singapore have made a big leap on research on the ‘mini-brain’. These advanced mini versions of the human midbrain will help researchers develop treatments and conduct other studies into Parkinson’s Disease  (PD) and ageing-related brain diseases. These mini midbrain versions are three-dimensional miniature tissues that are grown in the laboratory and they have certain properties of specific parts of the human brains. This is the first time that the black pigment neuromelanin has been detected in an organoid model. The study also revealed functionally active dopaminergic neurons.

The human midbrain, which is the information superhighway, controls auditory, eye movements, vision and body movements. It contains special dopaminergic neurons that produce dopamine – which carries out significant roles in executive functions, motor control, motivation, reinforcement, and reward. High levels of dopamine elevate motor activity and impulsive behaviour, whereas low levels of dopamine lead to slowed reactions and disorders like PD, which is characterised by stiffness and difficulties in initiating movements.

DIFFERENCIATION OF HUMAN EMBRIONIC

Also causing PD is the dramatic reduction in neuromelanin production, leading to the degenerative condition of patients, which includes tremors and impaired motor skills. This creation is a key breakthrough for studies in PD, which affects an estimated seven to 10 million people worldwide. Furthermore, there are people who are affected by other causes of parkinsonism. Researchers now have access to the material that is affected in the disease itself, and different types of studies can be conducted in the laboratory instead of through simulations or on animals. Using stem cells, scientists have grown pieces of tissue, known as brain organoids, measuring about 2 to 3 mm long. These organoids contain the necessary hallmarks of the human midbrain, which are dopaminergic neurons and neuromelanin.

Assistant Prof Shawn Je from Duke-NUS Medical School’s Neuroscience & Behavioural Disorders Programme said, “It is remarkable that our midbrain organoids mimic human midbrain development. The cells divide, cluster together in layers, and become electrically and chemically active in three-dimensional environment like our brain. Now we can really test how these mini brains react to existing or newly developed drugs before treating patients, which will be a game changer for drug development.”

Jointly led by Prof Ng Huck Hui from A*STAR’s Genome Institute of Singapore (GIS) and Assistant Prof Shawn Je from Duke-NUS Medical School, this collaborative research between GIS, Duke-NUS, and the National Neuroscience Institute (NNI) is funded by the National Medical Research Council’s Translational Clinical Research (TCR) Programme In Parkinson’s disease (PD) and A*STAR. Other collaborators are from the Lieber Institute for Brain Development, the Johns Hopkins University School of Medicine, and the Nanyang Technological University.

Source: https://www.a-star.edu.sg/