Energy & Green Tech

Engineers go microbial to store energy, sequester carbon dioxide

By borrowing nature's blueprints for photosynthesis, Cornell University bioengineers have found a way to efficiently absorb and store large-scale, low-cost renewable energy from the sun—while sequestering atmospheric carbon ...

Energy & Green Tech

High-rate Li-ion batteries demonstrate superior safety

As the inevitable growth of transport electrification continues, the types of batteries that will be used in such vehicles, their charging parameters, infrastructure and timeframes are key considerations that will speed up ...

Electronics & Semiconductors

New 2-D Ruddlesden-Popper (RP) layered perovskite-based solar cells

In recent years, researchers worldwide have been trying to develop solar cells and other technologies that can produce electrical energy from renewable sources, as these could reduce the emission of greenhouse gases and thus ...

Electronics & Semiconductors

New blended solar cells yield high power conversion efficiencies

Researchers at Hiroshima University in Japan have blended together various polymer and molecular semiconductors as photo-absorbers to create a solar cell with increased power efficiencies and electricity generation. These ...

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Cell (biology)

The cell is the structural and functional unit of all known living organisms. It is the smallest unit of an organism that is classified as living, and is often called the building block of life. Some organisms, such as most bacteria, are unicellular (consist of a single cell). Other organisms, such as humans, are multicellular. (Humans have an estimated 100 trillion or 1014 cells; a typical cell size is 10 µm; a typical cell mass is 1 nanogram.) The largest known cell is an unfertilized ostrich egg cell.

In 1835 before the final cell theory was developed, a Czech Jan Evangelista Purkyně observed small "granules" while looking at the plant tissue through a microscope. The cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells. All cells come from preexisting cells. Vital functions of an organism occur within cells, and all cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells.

The word cell comes from the Latin cellula, meaning, a small room. The descriptive name for the smallest living biological structure was chosen by Robert Hooke in a book he published in 1665 when he compared the cork cells he saw through his microscope to the small rooms monks lived in.

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