Artificial Photosynthesis

Artificial photosynthesis is a chemical process that replicates the natural process of photosynthesis, a process that converts sunlight, water, and carbon dioxide into carbohydrates and oxygen. The term is commonly used to refer to any scheme for capturing and storing the energy from sunlight in the chemical bonds of a fuel (a solar fuel). Photocatalytic water splitting converts water into protons (and eventually hydrogen) and oxygen, and is a main research area in artificial photosynthesis. Light-driven carbon dioxide reduction is another studied process, replicating natural carbon fixation. 

The photosynthetic reaction can be divided into two half-reactions (oxidation and reduction) , both of which are essential to producing fuel. In plant photosynthesis, water molecules are photo-oxidized to release oxygen and protons. The second stage of plant photosynthesis is a light-independent reaction that converts carbon dioxide into glucose. Researchers of artificial photosynthesis are developing photocatalysts to perform both of these reactions separately.

Here's how the reaction works: 

 
First of all, the photo-electrode is filled with water and illuminated. The light is absorbed, and the water molecules react, producing electrons, oxygen molecules, and hydrogen ions. The electrons move through wires to a catalyst electrode, where they react with CO2 and hydrogen ions in presence of metal catalyst and light. This reduction reaction produces organic substances, mainly formic acid. In addition, by designing the material for the metal catalyst, it's possible to vary the type of organic substances produced, such as hydrocarbons or alcohol.

Furthermore, the hydrogen and oxygen resulting from water splitting can be store for production electricity and pure water through fuel cell.

Recent developments & Applications: 

1) Panasonic (Osaka, Japan) has developed an artificial photosynthesis system which converts carbon dioxide (CO2) to organic materials by illuminating with sunlight at a world's top efficiency of 0.2%. The efficiency is on a comparable level with real plants used for biomass energy. The key to the system is the application of a nitride semiconductor which makes the system simple and efficient. This development will be a foundation for the realization of a system for capturing and converting wasted carbon dioxide from incinerators, power plants or industrial activities. On this development, Panasonic holds 18 domestic patents and 11 overseas patents, including pending applications. From now on, Panasonic aims to achieve an efficiency similar to that of plants in ethanol production. As a future prospect, the company wants to operate artificial photosynthesis plants, which could absorb CO2 from factories and produce ethanol. 

2) Inspired by the photosynthesis performed by plants, researchers at MIT had developed an unprecedented process that will allow the sun's energy to be used to split water into hydrogen and oxygen gases. Later, the oxygen and hydrogen may be recombined inside a fuel cell, creating carbon-free electricity to power your house or your electric car, day or night.

The key component of this new process is a new catalyst that produces oxygen gas from water; another catalyst produces valuable hydrogen gas. The new catalyst consists of cobalt metal, phosphate and an electrode, placed in water. When electricity — whether from a photovoltaic cell, a wind turbine or any other source — runs through the electrode, the cobalt and phosphate form a thin film on the electrode,  oxygen gas is produced. Than those gases are store for use in fuel cell to produce electricity and pure water.

Potential global impact 

Being a renewable and carbon-neutral source of solar fuels, producing either hydrogen (which when burnt or use in fuel cell produces energy and fresh water) or carbohydrates, artificial photosynthesis is set apart from other popular renewable energy sources, specifically hydroelectric, solar photovoltaic, geothermal, and wind – which produce electricity directly and centrally with no easily stored and transportable fuel intermediate. As such, artificial photosynthesis may become a very important source of fuel for transportation; unlike biomass energy, it does not require arable land and, consequently, will not compete with the food supply. One vision for globalizing artificial photosynthesis involves large light capture facilities linked to coastal metropolitan industrial plants where sea water is split to produce hydrogen and oxygen; the other involves all human structures covering the earth's surface (i.e., roads, vehicles and buildings) doing photosynthesis more efficiently than plants

Why newborn's immune systems aren’t fully functional

One of newborns’ biggest vulnerabilities is largely invisible: In the weeks after birth, babies are especially susceptible to infection because their immune systems aren’t fully functional. There are a handful of theories to explain this liability, and now a research team has added a new one to the list: Immune suppression in early life might help prevent inflammation in the infants’ intestines as they become colonized by the helpful bacteria they need to stay healthy.

Newborns are more likely than older babies to catch, and die from, serious infections. The reason is fuzzy—indeed, there may be more than one explanation. One theory is that much like their brains, their lungs, and the rest of their bodies, infants’ immune systems just haven’t fully matured yet. Another is that both mothers-to-be and their in utero companions have suppressed immune systems, so that neither rejects the other. After birth, the thinking goes, it takes babies a month or so to boost their immunity.

Others in Way’s lab study the gut microbiome, the constellation of healthy bacteria that populates our intestines. Newborn mice, just like human babies, are born “clean,” with little intestinal bacteria. Very rapidly that changes. Way wondered whether there might be some connection between this colonization and what looked like a purposeful suppression of the immune system in his mice.

To find out, his group focused on immune cells that eventually develop into red blood cells and that express a surface receptor called CD71, which causes immune suppression of other cells. Knocking out about 60% of these CD71 cells—as many as their technology could manage—was followed by significant inflammation in the intestines of the mouse pups. Way and his colleagues also found that, as the mice grew, fewer and fewer cells boasted CD71 receptors, suggesting the suppression wasn’t needed. He theorizes that that’s because the gut has been colonized by that point.

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GENETIC MUTATION That Controls The Blood Levels Of Triglycerides

BOSTON—We all know people who seem to have been born with good genes—they may smoke, never exercise, or consume large amounts of bacon, yet they remain seemingly healthy. Now, researchers have found that individuals who carry a rare genetic mutation that controls the blood levels of certain fats, or lipids, are protected from heart disease. The result, reported here yesterday at the annual meeting of the American Society of Human Genetics, suggests that a drug mimicking this effect could prevent heart disease, a major killer.Triglycerides are lipids that the body makes from unused calories in food and later burns as fuel. Doctors often monitor patients’ blood levels of these compounds because higher levels have been linked to a greater risk of heart disease.
One player in processing triglycerides is a protein called ApoC-III that is encoded by the geneAPOC3. Five years ago, researchers discovered a mutation in APOC3 in 5% of the Amish population in Lancaster County, Pennsylvania. Those with this variant had unusually low levels of triglycerides after consuming a fat-laden milkshake. They also had only half as much ApoC-III protein in their blood, and they were less likely to develop calcification of coronary arteries, which can lead to coronary heart disease.
The Amish group was too small to allow researchers to directly link the genetic mutation to less heart disease, however. And it wasn’t clear whether the gene would show up in non-Amish people.
Now, researchers have found APOC3 mutations in the general U.S. population. They sequenced the protein-coding DNA, or exomes, of 3734 white and African-American volunteers, then combed through the data for genetic variants linked to triglyceride levels. A few people turned out to have either the Amish APOC3 mutation or one of three other variants in APOC3that also disable this copy of the gene. When the team checked the DNA of a larger group of nearly 111,000 people, they found that about one in 200 carried one of the four APOC3variants, reported Jacy Crosby of the University of Texas Health Science Center, Houston, who represented a large consortium called the National Heart, Lung, and Blood Institute Exome Sequencing Project.

Read more: http://bit.ly/HpmLss via Science Now

Why Plants Usually Live Longer Than Animals

 Stem cells are crucial for the continuous generation of new cells. Although the importance of stem cells in fuelling plant growth and development still many questions on their tight molecular control remain unanswered. Plant researchers at VIB and Ghent University discovered a new step in the complex regulation of stem cells.

Today, their results are published online in this week's issue of Science Express.Lieven De Veylder said, "Our data suggest that certain organizing stem cells in plant roots are less sensitive for DNA-damage. Those cells hold an original and intact DNA copy which can be used to replace damaged cells if necessary. Animals rely on a similar mechanism but most likely plants have employed this in a more optimized manner. This could explain why many plants can live for more than hundreds of years, while this is quite exceptional for animals."

Quiescent organisers of plant growth

Plant growth and development depend on the continuous generation of new cells. A small group of specialized cells present in the growth axes of a plant is driving this. These so-called stem cells divide at a high frequency and have the unique characteristic that the original mother cell keeps the stem cell activity while the daughter cell acquires a certain specialization. Besides these stem cells, plant roots also harbor organizing cells. These organizing cells divide with a three- to ten-fold lower frequency, therefore often referred to as quiescent center cells. The organizing cells control the action of the surrounding stem cells and can replace them if necessary.

A new molecular network

For almost 20 years, scientists all over the world have been studying the action of the stem cells and that of their controlling organizing cells. Until now it was not known how quiescent and actively dividing cells could co-exist so closely and which mechanisms are at the basis of the quiescent character. Plant researchers at VIB and Ghent University have now identified a new molecular network that increases our understanding of stem cell regulation and activity.

Central in this process is the discovery of a new protein, the ERF115 transcription factor. The scientists demonstrated that the organizing cells barely divide because of the inhibition of ERF115 activity. When the organizing cells need to divide to replace damaged surrounding stem cells, ERF115 gets activated. ERF115 then stimulates the production of the plant hormone phytosulfokine which in turn activates the division of the organizing cells. Thus, the ERF115-phytosulfokine network acts as a back-up system during stress conditions which are detrimental for the activity of stem cells.

Reference - sciencedaily