Radar: A system using beamed and reflected radio signals to and from an object in such a way that range, bearing, and other characteristics of the object may be determined.Phantoms, Imaging: Devices or objects in various imaging techniques used to visualize or enhance visualization by simulating conditions encountered in the procedure. Phantoms are used very often in procedures employing or measuring x-irradiation or radioactive material to evaluate performance. Phantoms often have properties similar to human tissue. Water demonstrates absorbing properties similar to normal tissue, hence water-filled phantoms are used to map radiation levels. Phantoms are used also as teaching aids to simulate real conditions with x-ray or ultrasonic machines. (From Iturralde, Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990)Calibration: Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.Space Flight: Travel beyond the earth's atmosphere.Extraterrestrial Environment: The environment outside the earth or its atmosphere. The environment may refer to a closed cabin (such as a space shuttle or space station) or to space itself, the moon, or other planets.History, 17th Century: Time period from 1601 through 1700 of the common era.Awareness: The act of "taking account" of an object or state of affairs. It does not imply assessment of, nor attention to the qualities or nature of the object.Patents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.Phantom Limb: Perception of painful and nonpainful phantom sensations that occur following the complete or partial loss of a limb. The majority of individuals with an amputated extremity will experience the impression that the limb is still present, and in many cases, painful. (From Neurol Clin 1998 Nov;16(4):919-36; Brain 1998 Sep;121(Pt 9):1603-30)Dental Marginal Adaptation: The degree of approximation or fit of filling material or dental prosthetic to the tooth surface. A close marginal adaptation and seal at the interface is important for successful dental restorations.Triplets: Three individuals derived from three FETUSES that were fertilized at or about the same time, developed in the UTERUS simultaneously, and born to the same mother.Fetal Mortality: Number of fetal deaths with stated or presumed gestation of 20 weeks or more in a given population. Late fetal mortality is death after of 28 weeks or more.Quintuplets: Five individuals derived from five FETUSES that were fertilized at or about the same time, developed in the UTERUS simultaneously, and born to the same mother.Photoacoustic Techniques: Investigative and diagnostic methods and procedures based on the photoacoustic effect, which is the generation of SOUND WAVES from the absorption of ELECTROMAGNETIC RADIATION.Venous Thrombosis: The formation or presence of a blood clot (THROMBUS) within a vein.Thrombophlebitis: Inflammation of a vein associated with a blood clot (THROMBUS).Thrombosis: Formation and development of a thrombus or blood clot in the blood vessel.Optical Devices: Products or parts of products used to detect, manipulate, or analyze light, such as LENSES, refractors, mirrors, filters, prisms, and OPTICAL FIBERS.Femoral Vein: The vein accompanying the femoral artery in the same sheath; it is a continuation of the popliteal vein and becomes the external iliac vein.Radiology: A specialty concerned with the use of x-ray and other forms of radiant energy in the diagnosis and treatment of disease.Radiology Department, Hospital: Hospital department which is responsible for the administration and provision of x-ray diagnostic and therapeutic services.Radiology, Interventional: Subspecialty of radiology that combines organ system radiography, catheter techniques and sectional imaging.Models, Educational: Theoretical models which propose methods of learning or teaching as a basis or adjunct to changes in attitude or behavior. These educational interventions are usually applied in the fields of health and patient education but are not restricted to patient care.Infusions, Intraosseous: The administration of medication or fluid through a needle directly into the bone marrow. The technique is especially useful in the management of pediatric emergencies when intravenous access to the systemic circulation is difficult.Hyperthermia, Induced: Abnormally high temperature intentionally induced in living things regionally or whole body. It is most often induced by radiation (heat waves, infra-red), ultrasound, or drugs.Libraries, Digital: Libraries in which a major proportion of the resources are available in machine-readable format, rather than on paper or MICROFORM.Gold: A yellow metallic element with the atomic symbol Au, atomic number 79, and atomic weight 197. It is used in jewelry, goldplating of other metals, as currency, and in dental restoration. Many of its clinical applications, such as ANTIRHEUMATIC AGENTS, are in the form of its salts.Metal Nanoparticles: Nanoparticles produced from metals whose uses include biosensors, optics, and catalysts. In biomedical applications the particles frequently involve the noble metals, especially gold and silver.Nanoparticles: Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.Libraries: Collections of systematically acquired and organized information resources, and usually providing assistance to users. (ERIC Thesaurus, http://www.eric.ed.gov/ accessed 2/1/2008)Tomography, Optical: Projection of near-IR light (INFRARED RAYS), in the 700-1000 nm region, across an object in parallel beams to an array of sensitive photodetectors. This is repeated at various angles and a mathematical reconstruction provides three dimensional MEDICAL IMAGING of tissues. Based on the relative transparency of tissues to this spectra, it has been used to monitor local oxygenation, brain and joints.Radiometry: The measurement of radiation by photography, as in x-ray film and film badge, by Geiger-Mueller tube, and by SCINTILLATION COUNTING.Radiation Dosage: The amount of radiation energy that is deposited in a unit mass of material, such as tissues of plants or animal. In RADIOTHERAPY, radiation dosage is expressed in gray units (Gy). In RADIOLOGIC HEALTH, the dosage is expressed by the product of absorbed dose (Gy) and quality factor (a function of linear energy transfer), and is called radiation dose equivalent in sievert units (Sv).Bibliometrics: The use of statistical methods in the analysis of a body of literature to reveal the historical development of subject fields and patterns of authorship, publication, and use. Formerly called statistical bibliography. (from The ALA Glossary of Library and Information Science, 1983)Quinolinium CompoundsDequalinium: A topical bacteriostat that is available as various salts. It is used in wound dressings and mouth infections and may also have antifungal action, but may cause skin ulceration.Ear Protective Devices: Personal devices for protection of the ears from loud or high intensity noise, water, or cold. These include earmuffs and earplugs.Bone and Bones: A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principle cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.Spine: The spinal or vertebral column.Bone Density: The amount of mineral per square centimeter of BONE. This is the definition used in clinical practice. Actual bone density would be expressed in grams per milliliter. It is most frequently measured by X-RAY ABSORPTIOMETRY or TOMOGRAPHY, X RAY COMPUTED. Bone density is an important predictor for OSTEOPOROSIS.Science: The study of natural phenomena by observation, measurement, and experimentation.AmputeesAmputation Stumps: The part of a limb or tail following amputation that is proximal to the amputated section.Amputation, Traumatic: Loss of a limb or other bodily appendage by accidental injury.Amputation: The removal of a limb or other appendage or outgrowth of the body. (Dorland, 28th ed)Periodicals as Topic: A publication issued at stated, more or less regular, intervals.Writing: The act or practice of literary composition, the occupation of writer, or producing or engaging in literary work as a profession.Peer Review, Research: The evaluation by experts of the quality and pertinence of research or research proposals of other experts in the same field. Peer review is used by editors in deciding which submissions warrant publication, by granting agencies to determine which proposals should be funded, and by academic institutions in tenure decisions.Serial Publications: Publications in any medium issued in successive parts bearing numerical or chronological designations and intended to be continued indefinitely. (ALA Glossary of Library and Information Science, 1983, p203)Publishing: "The business or profession of the commercial production and issuance of literature" (Webster's 3d). It includes the publisher, publication processes, editing and editors. Production may be by conventional printing methods or by electronic publishing.Authorship: The profession of writing. Also the identity of the writer as the creator of a literary production.Neuroradiography: Radiography of the central nervous system.