Context: Deoxyribonucleic acid (DNA) is a molecule that carries the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses. DNA and RNA are nucleic acids; alongside proteins, lipids and complex carbohydrates (polysaccharides), they are one of the four major types of macromolecules that are essential for all known forms of life. Most DNA molecules consist of two biopolymer strands coiled around each other to form a double helix., Oral cancer, also known as mouth cancer, is a type of head and neck cancer and is any cancerous tissue growth located in the oral cavity., Molecular biology concerns the molecular basis of biological activity between biomolecules in the various systems of a cell, including the interactions between DNA, RNA, and proteins and their biosynthesis, as well as the regulation of these interactions. Writing in "Nature" in 1961, William Astbury described molecular biology as:, Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation, and expression of genes. RNA and DNA are nucleic acids, and, along with proteins and carbohydrates, constitute the four major macromolecules essential for all known forms of life. Like DNA, RNA is assembled as a chain of nucleotides, but unlike DNA it is more often found in nature as a single-strand folded onto itself, rather than a paired double-strand. Cellular organisms use messenger RNA (mRNA) to convey genetic information (using the letters G, U, A, and C to denote the nitrogenous bases guanine, uracil, adenine, and cytosine) that directs synthesis of specific proteins. Many viruses encode their genetic information using an RNA genome., A biomolecule or biological molecule is molecule that is present in living organisms, including large macromolecules such as proteins, carbohydrates, lipids, and nucleic acids, as well as small molecules such as primary metabolites, secondary metabolites, and natural products. A more general name for this class of material is biological materials. Biomolecules are usually endogenous but may also be exogenous. For example, pharmaceutical drugs may be natural products or semisynthetic (biopharmaceuticals) or they may be totally synthetic., William Thomas Astbury FRS (also Bill Astbury; 25 February 1898, Longton  4 June 1961, Leeds) was an English physicist and molecular biologist who made pioneering X-ray diffraction studies of biological molecules. His work on keratin provided the foundation for Linus Pauling's discovery of the alpha helix. He also studied the structure for DNA in 1937 and made the first step in the elucidation of its structure., Head and neck cancer is a group of cancers that starts within the mouth, nose, throat, larynx, sinuses, or salivary glands. Symptoms may include a lump or sore that does not heal, a sore throat that does not go away, trouble swallowing, or a change in the voice. There may also be unusual bleeding, facial swelling, or trouble breathing.
About 80% of head and neck cancer is due to the use of alcohol or tobacco. Other risk factors include betel quid, certain types of human papillomavirus, radiation exposure, certain workplace exposures, and Epstein-Barr virus. Head and neck cancers are most commonly of the squamous cell carcinoma type. The diagnosis is confirmed by tissue biopsy. The degree of spread may be determined by medical imaging and blood tests.
Prevention is by not using tobacco or alcohol. While screening in the general population does not appear to be useful, screening high risk groups by examination of the throat might be useful. Often head and neck cancer is curable if detected early; however, outcomes are typically poor if detected late. Treatment may include a combination of surgery, radiation therapy, chemotherapy, and targeted therapy. Following treatment of one head and neck cancer people are at higher risk of a second cancer.
In 2013 head and neck cancers globally affected more than 4.6 million people (mouth 2.4 million, throat 1.3 million, larynx 0.9 million) and resulted in more than 362,000 deaths (mouth 135,000, throat 139,000, larynx 88,000). Together they are the seventh most frequent cancer and the ninth most frequent cause of death from cancer. In the United States about one percent of people are affected at some point in their life and males are affected twice as often as females. The usual age at diagnosis is between 55 and 65 years. The average 5 year survival following diagnosis in the developed world is 42 to 64%., Dr. Xiaofeng Zhou , (  ) Associate Professor , Center for Molecular Biology of Oral Diseases , University of Illinois at Chicago College of Dentistry , is an internationally known oral cancer researcher . His primary research interest is to utilize molecular genetics and bioninformatics technologies to develop novel diagnostic tools and to gain a better understanding of human diseases such as head and neck / oral cancer . His research is focused on the genetic mapping of disease genes and / or consistent genomic alterations that are associated with the development and progression of oral cancer . Dr. Zhou previously had been an Assistant Professor of Oral Biology at the University of California , Los Angeles ( UCLA ) School of Dentistry , and also was a member of UCLA 's Jonsson Comprehensive Cancer Center and the university 's Dental Research Institute . He holds a BS in biochemistry and microbiology from Hangzhou University in China ; a PhD in biochemistry and a postdoctorate training in human genetics from Boston University ; and an MS in software engineering from Brandeis University . Dr. Zhou has published more than 80 journal articles , review articles , and book chapters , and holds three National Institutes of Health grant research projects . Dr. Zhou is also a Visiting Professor at Sun Yat - sen University , China ., Subject: xiaofeng zhou, Relation: occupation, Options: (A) general (B) major (C) molecular biologist (D) physicist
Output: molecular biologist