Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

[Q]: Context: Circular RNAs (circRNAs) are a class of newly-identified non-coding RNA molecules. CircRNAs are conserved across different species and display specific organization, sequence, and expression in disease. Moreover, circRNAs' closed ring structure, insensitivity to RNase, and stability are advantages over linear RNAs in terms of development and application as a new kind of clinical marker. In addition, according to recent studies, circular RNA-7 (ciRS-7) acts as a sponge of miR-7 and thus inhibits its activity. Numerous evidences have confirmed expression of miR-7 is dysregulated in cancer tissues, however, whether ciRS-7 invovled in oncogenesis by acting as sponge of miR-7 remains unclear. Most recently, a study reported ciRS-7 acted as an oncogene in hepatocellular carcinoma through targeting miR-7 expression. This suggest ciRS-7/ miR-7 axis affects oncogenesis, and it provides a new perspective on the mechanisms of decreased miR-7 expression in cancer tissues. Discovery of sponge role of circRNAs caused researchers to more closely explore the underlying mechanism of carcinogenesis and has significant clinical implications, and may open a new chapter in research on the pathology and treatment of cancers. This review summarizes the structure and function of circRNAs and provides evidence for the impact of ciRS-7 in promoting the development of cancer by acting as sponge of miR-7. 
 Question: Which miRNA is associated with the circular RNA ciRS-7?
[A]: mir-7


[Q]: Context: Carpal tunnel syndrome (CTS) is the most common median nerve neuropathy, accounting for 90% of all neuropathies. Carpal tunnel syndrome presents in 3.8% of the general population, with a higher prevalence among women. There are several risk factors associated with CTS, including both medical and non medical factors. The pathophysiologic mechanisms involved in the median nerve compression and traction are thought to be complex, and as yet are not fully understood. The present review aimed to provide an overview of the pathophysiology of median nerve neuropathy in the carpal tunnel, and subsequent development of CTS. 
 Question: What nerve is involved in carpal tunnel syndrome?
[A]: median


[Q]: Context: Nuclear fission is the splitting of the nucleus of an atom into two smaller nuclei. This type of reaction releases a great deal of energy from a very small amount of matter. For example, nuclear fission of a tiny pellet of uranium-235, like the one pictured in Figure 11.11, can release as much energy as burning 1,000 kilograms of coal! Nuclear fission of uranium-235 can be represented by this equation: 235 92 U + 1 141 Neutron !92 36 Kr + 56 Ba + 3 Neutrons + Energy As shown in Figure 11.12, the reaction begins when a nucleus of uranium-235 absorbs a neutron. This can happen naturally or when a neutron is deliberately crashed into a uranium nucleus in a nuclear power plant. In either case, the nucleus of uranium becomes very unstable and splits in two. In this example, it forms krypton-92 and barium-141. The reaction also releases three neutrons and a great deal of energy. The neutrons released in this nuclear fission reaction may be captured by other uranium nuclei and cause them to fission as well. This can start a nuclear chain reaction (see Figure 11.13). In a chain reaction, one fission reaction leads to others, which lead to others, and so on. A nuclear chain reaction is similar to a pile of wood burning. If you start one piece of wood burning, enough heat is produced by the burning wood to start the rest of the pile burning without any further help from you. You can see another example of a chain reaction at this URL: If a nuclear chain reaction is uncontrolled, it produces a lot of energy all at once. This is what happens in an atomic bomb. If a nuclear chain reaction is controlled, it produces energy more slowly. This is what occurs in a nuclear power plant. The reaction may be controlled by inserting rods of material that do not undergo fission into the core of fissioning material (see Figure 11.14). The radiation from the controlled fission is used to heat water and turn it to steam. The steam is under pressure and causes a turbine to spin. The spinning turbine runs a generator, which produces electricity. In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution, acid rain, and global warming. Fossil fuels are also limited and may eventually run out. Like fossil fuels, radioactive elements are limited. In fact, they are relatively rare, so they could run out sooner rather than later. On the other hand, nuclear fission does not release air pollution or cause the other environmental problems associated with burning fossil fuels. This is the major advantage of using nuclear fission as a source of energy. The main concern over the use of nuclear fission is the risk of radiation. Accidents at nuclear power plants can release harmful radiation that endangers people and other living things. Even without accidents, the used fuel that is left after nuclear fission reactions is still radioactive and very dangerous. It takes thousands of years for it to decay until it no longer releases harmful radiation. Therefore, used fuel must be stored securely to people and other living things. You can learn more about the problem of radioactive waste at this URL: Nuclear fusion is the opposite of nuclear fission. In fusion, two or more small nuclei combine to form a single, larger nucleus. An example is shown in Figure 11.15. In this example, two hydrogen nuclei fuse to form a helium nucleus. A neutron and a great deal of energy are also released. In fact, fusion releases even more energy than fission does. Nuclear fusion of hydrogen to form helium occurs naturally in the sun and other stars. It takes place only at extremely high temperatures. Thats because a great deal of energy is needed to overcome the force of repulsion between positively charged nuclei. The suns energy comes from fusion in its core, where temperatures reach millions of Kelvin (see Figure 11.16). Scientists are searching for ways to create controlled nuclear fusion reactions on Earth. Their goal is develop nuclear fusion power plants, where the energy from fusion of hydrogen nuclei can be converted to electricity. How this might work 
 Question: splitting of a nucleus into two smaller nuclei
[A]:
nuclear fission