Diamond
Boron
Anemia, Diamond-Blackfan
Nanodiamonds
Evolution, Planetary
Uranus
Surface Properties
Neptune
Materials Testing
Trichomonas vaginalis
Dental Cavity Preparation
Dissociation of CH4 at high pressures and temperatures: diamond formation in giant planet interiors? (1/104)
Experiments using laser-heated diamond anvil cells show that methane (CH4) breaks down to form diamond at pressures between 10 and 50 gigapascals and temperatures of about 2000 to 3000 kelvin. Infrared absorption and Raman spectroscopy, along with x-ray diffraction, indicate the presence of polymeric hydrocarbons in addition to the diamond, which is in agreement with theoretical predictions. Dissociation of CH4 at high pressures and temperatures can influence the energy budgets of planets containing substantial amounts of CH4, water, and ammonia, such as Uranus and Neptune. (+info)Occupational asthma with paroxysmal atrial fibrillation in a diamond polisher. (2/104)
We present a case of a diamond polisher who developed occupational asthma as a result of prolonged exposure to various potent and well-recognized asthma-inducing agents, including cobalt dust. Although the patient was seen by various medical professionals during the initial course of his illness and given an early diagnosis of a respiratory condition, there were no attempts to evaluate the nature of his work, and therefore to establish a possible causal relationship with his exposures. This case clearly illustrates the importance of such an assessment. The ultimate fate of this patient (he had to retire from his job with a chronic and permanent illness) could have been avoided by early environmental intervention. In addition, this case illustrates a possible complication of asthma, that is, a severe cardiac arrhythmia. In this case, both the patient's symptoms and the prescribed medications contributed to worsening of the patient's underlying condition. Early diagnosis and intervention of this patient's work practices could have avoided this complication. (+info)Determination of elastic modulus of dentin by small spherical diamond indenters. (3/104)
A nano-indentation test was applied to determine elastic modulus (E) and hardness (H) of dentin. Three spherical indenters with nominal radii of 20, 5 and 1 microns were used and load/partial-unload cycles were repeated. Each cycle provided E and contact pressure or Meyer's hardness. The plot of contact pressure versus penetration depth was converted into a normalized indentation stress-strain relationship, which was used to select the optimum maximum indentation force for each indenter. The results were compared with those determined by the conventional triangular pyramidal (Berkovich) indenter technique. The comparable E value, irrespective of radius, was 19.5-20.9 GPa and the 1 micron indenter was able to provide E values of peritubular (28.0 GPa) and intertubular dentin (14.9 GPa). The H values generated with the Berkovich indentation technique were comparable to those determined by the spherical indenter technique at indentation strains of 0.9 and 0.5 for the 1 and 5 microns indenters. (+info)Microbial activity at gigapascal pressures. (4/104)
We observed physiological and metabolic activity of Shewanella oneidensis strain MR1 and Escherichia coli strain MG1655 at pressures of 68 to 1680 megapascals (MPa) in diamond anvil cells. We measured biological formate oxidation at high pressures (68 to 1060 MPa). At pressures of 1200 to 1600 MPa, living bacteria resided in fluid inclusions in ice-VI crystals and continued to be viable upon subsequent release to ambient pressures (0.1 MPa). Evidence of microbial viability and activity at these extreme pressures expands by an order of magnitude the range of conditions representing the habitable zone in the solar system. (+info)Diamond burr superficial keratectomy for recurrent corneal erosions. (5/104)
AIMS: To evaluate the efficacy and safety of diamond burr superficial keratectomy in the treatment of recurrent corneal erosions. METHODS: A retrospective review of 54 eyes (47 patients) with recurrent corneal erosions treated with diamond burr superficial keratectomy. Preoperative and postoperative visual acuities and refractions, slit lamp examination findings, and the incidence of recurrent erosion after keratectomy were studied. Specular microscopy was also performed in six patients before and after surgery. RESULTS: 30 eyes had underlying map dot fingerprint anterior basement membrane corneal dystrophy, while 24 eyes did not. Postoperative follow up time ranged from 3 to 53 months (mean 12.3 months). Corneal erosion recurred in three eyes (6%) after diamond burr superficial keratectomy. This procedure improved the best corrected visual acuity from 20/26 to 20/22 by logMAR statistical evaluation (p=0.002) and caused very little change in the refractive spherical equivalent. No endothelial cell loss or changes in morphology were noted on specular microscopy. CONCLUSION: Diamond burr superficial keratectomy appears to be an effective and safe method of treating recurrent erosions and is a good alternative therapy to needle stromal micropuncture, Nd:YAG induced epithelial adhesion, and excimer laser surface ablation. (+info)Quantitative analysis of dental porcelain surfaces following different treatments: correlation between parameters obtained by a surface profiling instrument. (6/104)
This investigation compared, by quantitative analysis, the surface roughness of dental porcelain submitted to three different treatments (glaze, trimming and polishing), utilizing a surface profiling instrument. The parameters Ra (median roughness), Rz (median of the maximum profile heights of five sample lengths), Rpm (median of the maximum profile heights related to the median line of five sample lengths), Pc (peak count per centimeter) and Rpm/Rz (proportional parameter) were evaluated. In addition, the correlation between Ra and the other parameters was analyzed. Based on the results obtained, it was seen that the Ra parameter did not present any correlation with the other parameters in some of the situations evaluated. This demonstrates that complementation of the measurement with other parameters is always necessary, providing a better evaluation of the functional properties of a surface. (+info)Surface roughness of composite resins after finishing and polishing. (7/104)
This study evaluated the effect of surface finishing methods on the average surface roughness of resin composites. Seven composites and two polishing systems were used. One hundred and twenty-six conical specimens of each material were prepared in stainless steel molds against a polyester strip. Forty-two of them remained intact and were used as controls. Each half of the remaining samples was polished with either diamond burs or diamond burs + aluminum oxide discs. The results showed no statistical difference in average surface roughness (Ra, microm) between the polyester strip and aluminum oxide discs (p > 0.05). However, finishing with diamond burs showed a statistically higher average roughness for all composites (p < 0.05). Statistical differences were detected among materials (p < 0.05) in the use of diamond burs. (+info)A pilot investigation of enamel reduction procedures. (8/104)
OBJECTIVE: To test and describe the use of various combinations of mechanical and chemical techniques for enamel reduction to obtain a smooth surface. METHODS: Bovine teeth (2 surfaces on each of 32 teeth) were used. The teeth were mounted in blocks of dental plaster, which were then mounted in a vise. The mesiodistal enamel contact areas were reduced by various combinations of mechanical and chemical aids. The mesiodistal width of each tooth was measured with a digital caliper after initial reduction of the enamel surface and again after polishing. The teeth were subsequently prepared and mounted for scanning electron microscopy. RESULTS: All combinations yielded statistically significant enamel reduction (p < 0.05). The use of acid stripping in conjunction with mechanical procedures produced especially smooth enamel surfaces. CONCLUSIONS: Steps must be taken to ensure that a smooth enamel surface remains after enamel reduction and polishing. It is recommended that conventional enamel etchants be added to the polishing procedure. Enamel reduction can increase available space, but the quantity of enamel that can be removed without adverse consequences should be carefully evaluated. (+info)I believe you are asking for a medical explanation or definition of the term "diamond" in a medical context. However, I should clarify that "diamond" is not a commonly used medical term for a specific disease, condition, or diagnostic feature. It's essential to provide more information if it relates to a particular medical concept or usage.
In general, the term "diamond" refers to a clear and colorless form of carbon with a crystalline structure in which each carbon atom is bonded to four other carbon atoms, forming a tetrahedral shape. It's widely known for its use as a valuable gemstone due to its exceptional hardness, brilliance, and fire.
However, there are some tangential medical connections to the term "diamond." For example:
1. Diamond Blackfan anemia (DBA): A rare congenital bone marrow failure disorder characterized by a decrease in red blood cell production. It is named after Drs. Louis Diamond and Kenneth Blackfan, who first described it.
2. Turner syndrome with XY sex chromosomes: A rare genetic condition where an individual has only one functional X chromosome instead of the typical pair (XX) found in females. Occasionally, these individuals may have a Y chromosome fragment, often referred to as "mosaic Turner syndrome with XY cells" or "XY gonadal dysgenesis." In this context, the term "XY" is sometimes metaphorically described as a "genetic male's 'diamond in the rough'" due to its rarity and unique characteristics.
If you have more information about how the term "diamond" is being used in your specific medical context, I would be happy to help further clarify or provide additional details.
Dental high-speed equipment typically refers to the handpiece used in dental procedures that operates at high rotational speeds, often exceeding 100,000 revolutions per minute (RPM). These handpieces are used for cutting and removing tooth structure, such as during cavity preparation or tooth reduction for restorations. They are called "high-speed" to distinguish them from slow-speed handpieces that operate at lower RPMs, typically under 10,000, and are used for procedures like polishing or cutting softer materials. High-speed handpieces are an essential part of modern dental practice, enabling precise and efficient removal of tooth structure while minimizing patient discomfort and procedure time.
Boron is a chemical element with the symbol B and atomic number 5. It is a metalloid that is light-colored, hard, and highly resistant to corrosion. In its crystalline form, boron is nearly as hard as diamond.
In medicine, boron compounds have been studied for their potential therapeutic uses, particularly in the treatment of cancer. For example, boron neutron capture therapy (BNCT) is a type of radiation therapy that involves the use of boron-containing compounds to selectively deliver radiation to cancer cells.
Boron is also an essential micronutrient for plants and some animals, including humans. However, excessive exposure to boron can be toxic to humans and other organisms. Therefore, it is important to maintain appropriate levels of boron in the body and environment.
Diamond-Blackfan anemia is a rare, congenital bone marrow failure disorder characterized by a decreased production of red blood cells (erythroblasts) in the bone marrow. This results in a reduced number of circulating red blood cells, leading to anemia and related symptoms such as fatigue, weakness, and pallor. The disorder is typically diagnosed in infancy or early childhood and can also be associated with physical abnormalities.
The exact cause of Diamond-Blackfan anemia is not fully understood, but it is believed to involve genetic mutations that affect the development and function of the bone marrow. In many cases, the disorder is inherited in an autosomal dominant manner, meaning that a child has a 50% chance of inheriting the mutated gene from an affected parent. However, some cases may arise spontaneously due to new genetic mutations.
Treatment for Diamond-Blackfan anemia typically involves regular blood transfusions to maintain adequate red blood cell levels and alleviate symptoms. Corticosteroid therapy may also be used to stimulate red blood cell production in some cases. In severe or refractory cases, stem cell transplantation may be considered as a curative treatment option.
Dental polishing is a procedure in dentistry that is performed to smooth and clean the surfaces of teeth after professional dental cleaning (prophylaxis), restoration, or other dental treatments. It is usually done using a slow-speed handpiece with a soft, rubber cup attached to it, which holds a polishing paste or a slurry of pumice and water. The polishing paste may contain an abrasive agent, fluoride, or a flavoring agent. The dental professional moves the handpiece in a circular motion over the tooth surface to remove stains, plaque, and minor surface roughness, leaving the teeth smooth and shiny. Dental polishing helps to prevent the buildup of plaque and tartar, reduce the risk of decay and gum disease, and improve the overall oral hygiene and aesthetics of the teeth.
Nanodiamonds are a type of carbon nanoparticle with a diamond crystal structure. They have at least one dimension in the nanometer scale, typically ranging from 1 to 100 nanometers. These particles exhibit unique physical and chemical properties that make them valuable for various applications, including biomedical research and therapeutics.
In the context of medical definitions, nanodiamonds are often discussed as potential drug delivery vehicles or diagnostic agents due to their biocompatibility, high surface area-to-volume ratio, and ability to bind with different molecules. They can be functionalized with drugs, proteins, or other biomolecules, allowing for targeted drug release or imaging in specific cells or tissues.
However, it is essential to note that the use of nanodiamonds in medical applications is still under investigation and development. While they show promise as a novel platform for diagnostics and therapeutics, more research is needed to establish their safety and efficacy before widespread clinical adoption.
Planetary evolution is a field of study that focuses on the processes that have shaped the formation, development, and changes of planets and other celestial bodies over time. This encompasses various scientific disciplines, including astronomy, astrobiology, geology, and atmospheric science. The study of planetary evolution helps scientists understand how planets form, how they change over time, and the conditions that allow for the development of life.
The process of planetary evolution can be driven by a variety of factors, including:
1. Formation: Planets form from a protoplanetary disk, a rotating disk of gas and dust surrounding a young star. Over time, solid particles in the disk collide and stick together to form larger and larger bodies, eventually leading to the formation of planets.
2. Internal differentiation: As planets grow, their interiors differentiate into layers based on density, with heavier materials sinking towards the center and lighter materials rising towards the surface. This process can lead to the formation of a core, mantle, and crust.
3. Geological activity: Planetary evolution is also influenced by geological processes such as volcanism, tectonics, and erosion. These processes can shape the planet's surface, create mountain ranges, and carve out valleys and basins.
4. Atmospheric evolution: The evolution of a planet's atmosphere is closely tied to its geological activity and the presence of volatiles (gases that easily vaporize). Over time, the composition of a planet's atmosphere can change due to processes such as outgassing from the interior, chemical reactions, and interactions with the solar wind.
5. Climate evolution: The climate of a planet can also evolve over time due to changes in its orbit, axial tilt, and atmospheric composition. These factors can influence the amount of sunlight a planet receives and the greenhouse effect, which can lead to global warming or cooling.
6. Impact events: Collisions with other celestial bodies, such as asteroids and comets, can significantly impact a planet's evolution by causing large-scale changes to its surface and atmosphere.
7. Life: On planets where life emerges, biological processes can also play a role in shaping the planet's environment and influencing its evolution. For example, photosynthetic organisms can produce oxygen, which can alter the composition of a planet's atmosphere.
Understanding the various factors that contribute to a planet's evolution is crucial for understanding the formation and development of planetary systems and searching for potentially habitable exoplanets.
I'm sorry for any confusion, but the term 'Uranus' is not a medical concept or condition. It is the seventh planet from the Sun in our solar system. If you have any medical questions or terms you would like defined, I'd be happy to help!
Surface properties in the context of medical science refer to the characteristics and features of the outermost layer or surface of a biological material or structure, such as cells, tissues, organs, or medical devices. These properties can include physical attributes like roughness, smoothness, hydrophobicity or hydrophilicity, and electrical conductivity, as well as chemical properties like charge, reactivity, and composition.
In the field of biomaterials science, understanding surface properties is crucial for designing medical implants, devices, and drug delivery systems that can interact safely and effectively with biological tissues and fluids. Surface modifications, such as coatings or chemical treatments, can be used to alter surface properties and enhance biocompatibility, improve lubricity, reduce fouling, or promote specific cellular responses like adhesion, proliferation, or differentiation.
Similarly, in the field of cell biology, understanding surface properties is essential for studying cell-cell interactions, cell signaling, and cell behavior. Cells can sense and respond to changes in their environment, including variations in surface properties, which can influence cell shape, motility, and function. Therefore, characterizing and manipulating surface properties can provide valuable insights into the mechanisms of cellular processes and offer new strategies for developing therapies and treatments for various diseases.
I'm sorry for any confusion, but "Neptune" is not a term commonly used in medical definitions. Neptune is the eighth and farthest known planet from the Sun in the Solar System. It is the fourth-largest planet by diameter and the third-largest by mass.
If you have any questions related to medical terminology or health concerns, I'd be happy to help with those instead!
I'm happy to help! However, I must clarify that "materials testing" is not a medical term per se. It is a term used in various fields, including engineering and materials science, to describe the process of subjecting materials to different tests to evaluate their properties and performance under various conditions.
In the context of medical devices or implants, materials testing may refer to the evaluation of the physical and mechanical properties of materials used in their construction. These tests can include assessments of strength, durability, biocompatibility, and other factors that are critical to ensuring the safety and efficacy of medical devices.
Medical device manufacturers must comply with regulatory standards for materials testing to ensure that their products meet specific requirements for performance, safety, and quality. These standards may vary depending on the type of device, its intended use, and the country or region in which it will be marketed and sold.
Electroplating is not a medical term, but rather a process used in the industrial field. It refers to the process of coating an electrically conductive object with a thin layer of metal through the use of an electrical current. This process involves immersing the object in a solution containing dissolved ions of the metal to be deposited, and then passing an electric current through the solution. The object serves as the cathode, and the metal ions are reduced at its surface, forming a thin layer of pure metal.
While electroplating is not directly related to medicine, it does have some medical applications. For example, medical devices such as pacemakers or implantable defibrillators may be coated with gold or other metals through electroplating to improve their biocompatibility and reduce the risk of corrosion or rejection by the body. Similarly, dental restorations may be electroplated with precious metals to enhance their strength and durability.
Trichomonas vaginalis is a species of protozoan parasite that causes the sexually transmitted infection known as trichomoniasis. It primarily infects the urogenital tract, with women being more frequently affected than men. The parasite exists as a motile, pear-shaped trophozoite, measuring about 10-20 micrometers in size.
T. vaginalis infection can lead to various symptoms, including vaginal discharge with an unpleasant odor, itching, and irritation in women, while men may experience urethral discharge or discomfort during urination. However, up to 50% of infected individuals might not develop any noticeable symptoms, making the infection challenging to recognize and treat without medical testing.
Diagnosis typically involves microscopic examination of vaginal secretions or urine samples, although nucleic acid amplification tests (NAATs) are becoming more common due to their higher sensitivity and specificity. Treatment usually consists of oral metronidazole or tinidazole, which are antibiotics that target the parasite's ability to reproduce. It is essential to treat both partners simultaneously to prevent reinfection and ensure successful eradication of the parasite.
Dental cavity preparation is the process of removing decayed and damaged tissue from a tooth and shaping the remaining healthy structure in order to prepare it for the placement of a filling or a crown. The goal of cavity preparation is to remove all traces of decay and create a clean, stable surface for the restoration to bond with, while also maintaining as much of the natural tooth structure as possible.
The process typically involves the use of dental drills and other tools to remove the decayed tissue and shape the tooth. The size and depth of the preparation will depend on the extent of the decay and the type of restoration that will be used. After the preparation is complete, the dentist will place the filling or crown, restoring the function and integrity of the tooth.
The dental high-speed technique is a method used in dentistry that involves the use of an air-driven handpiece, also known as a "high-speed" handpiece, to remove tooth structure quickly and efficiently during various procedures such as cavity preparation or tooth reduction for restorations. The term "high-speed" refers to the rotation speed of the bur (cutting tool) in the handpiece, which can reach up to 400,000 revolutions per minute (RPM). This technique allows dentists to complete treatments more efficiently and with greater precision compared to using slower-speed handpieces.
The high-speed technique is commonly used for:
1. Removing decayed tooth structure during cavity preparation
2. Reducing tooth size or shape prior to placing restorations, such as crowns, veneers, or inlays/onlays
3. Smoothing rough surfaces on teeth or restorations
4. Trimming or shaping excess material from dental restorations
5. Sectioning teeth for easier removal or extraction
When performing high-speed techniques, dentists must exercise caution to avoid damaging healthy tooth structure, pulp exposure, or causing patient discomfort. They typically use water coolant and/or air to reduce heat generation and minimize potential damage to the tooth. Additionally, high-speed handpieces are often equipped with a built-in spray system that helps wash away debris and maintain visibility during procedures.
In summary, the dental high-speed technique is a valuable tool in modern dentistry for efficiently and precisely removing tooth structure or shaping restorations using an air-driven high-speed handpiece.