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Dose Fractionation
Dose fractionation effects are utilised in the treatment of cancer with radiation therapy. When the total dose of radiation is divided into several, smaller doses over a period of several days, there are fewer toxic effects on healthy cells. This maximizes the effect of radiation on cancer and minimizes the negative side effects. A typical fractionation scheme divides the dose into 30 units delivered every weekday over six weeks. Background Experiments in radiation biology have found that as the absorbed dose of radiation increases, the number of cells which survive decreases. They have also found that if the radiation is ''fractionated'' into smaller doses, with one or more rest periods in between, fewer cells die. This is because of self-repair mechanisms which repair the damage to DNA and other biomolecules such as proteins. These mechanisms can be over expressed in cancer cells, so caution should be used in using results for a cancer cell line to make predictions for heal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cancer
Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible Signs and symptoms of cancer, signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss, and a change in defecation, bowel movements. While these symptoms may indicate cancer, they can also have other causes. List of cancer types, Over 100 types of cancers affect humans. Tobacco use is the cause of about 22% of cancer deaths. Another 10% are due to obesity, poor Diet (nutrition), diet, sedentary lifestyle, lack of physical activity or Alcohol abuse, excessive alcohol consumption. Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants. infectious causes of cancer, Infection with specific viruses, bacteria and parasites is an environmental factor cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deinococcus Radiodurans
''Deinococcus radiodurans'' is a bacterium, an extremophile and one of the most radiation-resistant organisms known. It can survive cold, dehydration, vacuum, and acid, and therefore is known as a polyextremophile. ''The Guinness Book Of World Records'' listed it in January 1998 as the world's most radiation-resistant bacterium or lifeform. Several bacteria of comparable radioresistance are known, including some species of the genus '' Chroococcidiopsis'' (phylum cyanobacteria) and some species of '' Rubrobacter'' (phylum Actinomycetota); among the archaea, the species '' Thermococcus gammatolerans'' shows comparable radioresistance. Name and classification The name ''Deinococcus radiodurans'' derives from the Ancient Greek δεινός () and κόκκος () meaning "terrible grain/berry" and the Latin and , meaning "radiation-surviving". The species was formerly called ''Micrococcus radiodurans''. As a consequence of its hardiness, it has been nicknamed “Conan the Bacteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Biology
Cell biology (also cellular biology or cytology) is a branch of biology that studies the structure, function, and behavior of cells. All living organisms are made of cells. A cell is the basic unit of life that is responsible for the living and functioning of organisms. Cell biology is the study of the structural and functional units of cells. Cell biology encompasses both prokaryotic and eukaryotic cells and has many subtopics which may include the study of cell metabolism, cell communication, cell cycle, biochemistry, and cell composition. The study of cells is performed using several microscopy techniques, cell culture, and cell fractionation. These have allowed for and are currently being used for discoveries and research pertaining to how cells function, ultimately giving insight into understanding larger organisms. Knowing the components of cells and how cells work is fundamental to all biological sciences while also being essential for research in biomedical fiel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Royal College Of Radiologists
The Royal College of Radiologists (RCR) is the professional body responsible for the specialties of clinical oncology and clinical radiology throughout the United Kingdom. Its role is to advance the science and practice of radiology and oncology, further public education, and set appropriate professional standards of practice. The college sets and monitors the educational curriculum for those training to enter the profession and administers the Fellowship of the Royal College of Radiologists exams. It is a registered charity in the United Kingdom (no. 211540). The RCR has 2 faculties, representing Clinical Oncology and Clinical Radiology. It publishes two academic journals, ''Clinical Oncology'' and Clinical Radiology'. The RCR has been based at 63 Lincoln's Inn Fields in London since July 2013. History A series of bodies has represented practitioners of radiological medicine in the UK, starting in 1897 with the foundation of the Roentgen Society (named for the physicist Wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centers For Disease Control And Prevention
The Centers for Disease Control and Prevention (CDC) is the National public health institutes, national public health agency of the United States. It is a Federal agencies of the United States, United States federal agency under the United States Department of Health and Human Services, Department of Health and Human Services (HHS), and is headquartered in Atlanta, Georgia. The CDC's current nominee for director is Susan Monarez. She became acting director on January 23, 2025, but stepped down on March 24, 2025 when nominated for the director position. On May 14, 2025, Robert F. Kennedy Jr. stated that lawyer Matthew Buzzelli is acting CDC director. However, the CDC web site does not state the acting director's name. The agency's main goal is the protection of public health and safety through the control and prevention of disease, injury, and disability in the US and worldwide. The CDC focuses national attention on developing and applying disease control and prevention. It e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intestines
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascular system. The GI tract contains all the major organs of the digestive system, in humans and other animals, including the esophagus, stomach, and intestines. Food taken in through the mouth is digested to extract nutrients and absorb energy, and the waste expelled at the anus as feces. ''Gastrointestinal'' is an adjective meaning of or pertaining to the stomach and intestines. Most animals have a "through-gut" or complete digestive tract. Exceptions are more primitive ones: sponges have small pores ( ostia) throughout their body for digestion and a larger dorsal pore ( osculum) for excretion, comb jellies have both a ventral mouth and dorsal anal pores, while cnidarians and acoels have a single pore for both digestion and excretion. The human ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Cells
A blood cell (also called a hematopoietic cell, hemocyte, or hematocyte) is a cell produced through hematopoiesis and found mainly in the blood. Major types of blood cells include red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes). Together, these three kinds of blood cells add up to a total 45% of the blood tissue by volume, with the remaining 55% of the volume composed of plasma, the liquid component of blood. Red blood cells Red blood cells or ''erythrocytes'' primarily carry oxygen and collect carbon dioxide through the use of hemoglobin. Hemoglobin is an iron-containing protein that gives red blood cells their color and facilitates transportation of oxygen from the lungs to tissues and carbon dioxide from tissues to the lungs to be exhaled. Red blood cells are the most abundant cell in the blood, accounting for about 40–45% of its volume. Red blood cells are circular, biconcave, disk-shaped and deformable to allow them to sque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone Marrow
Bone marrow is a semi-solid biological tissue, tissue found within the Spongy bone, spongy (also known as cancellous) portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production (or haematopoiesis). It is composed of Blood cell, hematopoietic cells, marrow adipose tissue, and supportive stromal cells. In adult humans, bone marrow is primarily located in the Rib cage, ribs, vertebrae, sternum, and Pelvis, bones of the pelvis. Bone marrow comprises approximately 5% of total body mass in healthy adult humans, such that a person weighing 73 kg (161 lbs) will have around 3.7 kg (8 lbs) of bone marrow. Human marrow produces approximately 500 billion blood cells per day, which join the Circulatory system, systemic circulation via permeable vasculature sinusoids within the medullary cavity. All types of Hematopoietic cell, hematopoietic cells, including both Myeloid tissue, myeloid and Lymphocyte, lymphoid lineages, are create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation Sickness
Acute radiation syndrome (ARS), also known as radiation sickness or radiation poisoning, is a collection of health effects that are caused by being exposed to high amounts of ionizing radiation in a short period of time. Symptoms can start within an hour of exposure, and can last for several months. Early symptoms are usually nausea, vomiting and loss of appetite. In the following hours or weeks, initial symptoms may appear to improve, before the development of additional symptoms, after which either recovery or death follows. ARS involves a total dose of greater than 0.7 Gy (70 rad), that generally occurs from a source outside the body, delivered within a few minutes. Sources of such radiation can occur accidentally or intentionally. They may involve nuclear reactors, cyclotrons, certain devices used in cancer therapy, nuclear weapons, or radiological weapons. It is generally divided into three types: bone marrow, gastrointestinal, and neurovascular syndrome, with bone m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organ (anatomy)
In a multicellular organism, an organ is a collection of Tissue (biology), tissues joined in a structural unit to serve a common function. In the biological organization, hierarchy of life, an organ lies between Tissue (biology), tissue and an organ system. Tissues are formed from same type Cell (biology), cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The Gastrointestinal tract, intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system. An organ's tissues can be broadly categorized as parenchyma, the functional tissue, and stroma (tissue), stroma, the structural tissue with supportive, connective, or ancillary functions. For example, the gland's tissue that makes the hormones is the parenchyma, whereas the stroma includes the nerve t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Body
The human body is the entire structure of a Human, human being. It is composed of many different types of Cell (biology), cells that together create Tissue (biology), tissues and subsequently Organ (biology), organs and then Organ system, organ systems. The external human body consists of a human head, head, hair, neck, torso (which includes the thorax and abdomen), Sex organ, genitals, arms, Hand, hands, human leg, legs, and Foot, feet. The internal human body includes organs, Human tooth, teeth, bones, muscle, tendons, ligaments, blood vessels and blood, lymphatic vessels and lymph. The study of the human body includes anatomy, physiology, histology and embryology. The body Anatomical variation, varies anatomically in known ways. Physiology focuses on the systems and organs of the human body and their functions. Many systems and mechanisms interact in order to maintain homeostasis, with safe levels of substances such as sugar, iron, and oxygen in the blood. The body is st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypothetical
A hypothesis (: hypotheses) is a proposed explanation for a phenomenon. A scientific hypothesis must be based on observations and make a testable and reproducible prediction about reality, in a process beginning with an educated guess or thought. If a hypothesis is repeatedly independently demonstrated by experiment to be true, it becomes a scientific theory. In colloquial usage, the words "hypothesis" and "theory" are often used interchangeably, but this is incorrect in the context of science. A working hypothesis is a provisionally-accepted hypothesis used for the purpose of pursuing further progress in research. Working hypotheses are frequently discarded, and often proposed with knowledge (and warning) that they are incomplete and thus false, with the intent of moving research in at least somewhat the right direction, especially when scientists are stuck on an issue and brainstorming ideas. A different meaning of the term ''hypothesis'' is used in formal logic, to d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
