Quartz
Quartz Crystal Microbalance Techniques
Silicosis
Threshold Limit Values
Silicon Dioxide
Carbon Compounds, Inorganic
Coal Mining
Polyvinylpyridine N-Oxide
Pneumoconiosis
Air Pollutants, Occupational
Inhalation Exposure
Biosensing Techniques
Aluminum Silicates
Occupational Exposure
Adsorption
Role of the scavenger receptor MARCO in alveolar macrophage binding of unopsonized environmental particles. (1/331)
Alveolar macrophages (AMs) avidly bind and ingest unopsonized environmental particles and bacteria through scavenger-type receptors (SRs). AMs from mice with a genetic deletion of the major macrophage SR (types AI and AII; SR-/-) showed no decrease in particle binding compared with SR+/+ mice, suggesting that other SRs are involved. To identify these receptors, we generated a monoclonal antibody (mAb), PAL-1, that inhibits hamster AM binding of unopsonized particles (TiO2, Fe2O3, and latex beads; 66 +/- 5, 77 +/- 2, and 85 +/- 2% inhibition, respectively, measured by flow cytometry). This antibody identifies a protein of approximately 70 kD on the AM surface (immunoprecipitation) that is expressed by AMs and other macrophages in situ. A cDNA clone encoding the mAb PAL-1-reactive protein isolated by means of COS cell expression was found to be 84 and 77% homologous to mouse and human scavenger receptor MARCO mRNA, respectively. Transfection of COS cells with MARCO cDNA conferred mAb-inhibitable TiO2 binding. Hamster MARCO also mediates AM binding of unopsonized bacteria (67 +/- 5 and 47 +/- 4% inhibition of Escherichia coli and Staphylococcus aureus binding by mAb PAL-1). A polyclonal antibody to human MARCO identified the expected approximately 70-kD band on Western blots of lysates of normal bronchoalveolar lavage (BAL) cells (>90% AMs) and showed strong immunolabeling of human AMs in BAL cytocentrifuge preparations and within lung tissue specimens. In normal mouse AMs, the anti-MARCO mAb ED31 also showed immunoreactivity and inhibited binding of unopsonized particles (e.g., TiO2 approximately 40%) and bacteria. The novel function of binding unopsonized environmental dusts and pathogens suggests an important role for MARCO in the lungs' response to inhaled particles. (+info)Occupational exposure to dust in quartz manufacturing industry. (2/331)
Owing to the abundance of a sedimentary rock, 65 small-scale quartz manufacturing enterprises, employing 650 workers, have been established in the region studied. Quartz powder manufacturing involves various processes and operations, such as manual handling of quartz stones, crushing, grinding, sieving, screening, mixing, storing and bagging. Results demonstrate that each of these operations generates high concentrations of airborne 'total' dust and respirable dust, which contain a very high percentage (> 75%) free silica. The estimated average exposure to airborne 'total' dust was 22.5 mg m-3 (Permissible Limit of Exposure 1.08 mg m-3), and respirable dust 2.93 mg m-3 (PLE 0.36 mg m-3). This shows that 'total' dust exposure was 7.7 times higher than respirable dust. Since the present work systems and practices may pose a serious health risk to the workers, public and the environment, suitable preventive and control measures have been suggested for improvement in the workplace. (+info)Risks of respiratory disease in the heavy clay industry. (3/331)
OBJECTIVES: Little information is available on the quantitative risks of respiratory disease from quartz in airborne dust in the heavy clay industry. Available evidence suggested that these risks might be low, possibly because of the presence in the dust of other minerals, such as illite and kaolinite, which may reduce the harmful effects of quartz. The aims of the present cross sectional study were to determine among workers in the industry (a) their current and cumulative exposures to respirable mixed dust and quartz; (b) the frequencies of chest radiographic abnormalities and respiratory symptoms; (c) the relations between cumulative exposure to respirable dust and quartz, and risks of radiographic abnormality and respiratory symptoms. METHODS: Factories were chosen where the type of process had changed as little as possible during recent decades. 18 were selected in England and Scotland, ranging in size from 35 to 582 employees, representing all the main types of raw material, end product, kilns, and processes in the manufacture of bricks, pipes, and tiles but excluding refractory products. Weights of respirable dust and quartz in more than 1400 personal dust samples, and site histories, were used to derive occupational groups characterised by their levels of exposure to dust and quartz. Full size chest radiographs, respiratory symptoms, smoking, and occupational history questionnaires were administered to current workers at each factory. Exposure-response relations were examined for radiographic abnormalities (dust and quartz) and respiratory symptoms (dust only). RESULTS: Respirable dust and quartz concentrations ranged from means of 0.4 and 0.04 mg.m-3 for non-process workers to 10.0 and 0.62 mg.m-3 for kiln demolition workers respectively. Although 97% of all quartz concentrations were below the maximum exposure limit of 0.4 mg.m-3, 10% were greater than this among the groups of workers exposed to most dust. Cumulative exposure calculations for dust and quartz took account of changes of occupational group, factory, and kiln type at study and non-study sites. Because of the importance of changes of kiln type additional weighting factors were applied to concentrations of dust and quartz during previous employment at factories that used certain types of kiln. 85% (1934 employees) of the identified workforce attended the medical surveys. The frequency of small opacities in the chest radiograph, category > or = 1/0, was 1.4% (median reading) and seven of these 25 men had category > or = 2/1. Chronic bronchitis was reported by 14.2% of the workforce and breathlessness, when walking with someone of their own age, by 4.4%. Risks of having category > or = 0/1 small opacities differed by site and were also influenced by age, smoking, and lifetime cumulative exposure to respirable dust and quartz. Although exposures to dust and to quartz were highly correlated, the evidence suggested that radiological abnormality was associated with quartz rather than dust. A doubling of cumulative quartz exposure increased the risk of having category > or = 0/1 by a factor of 1.33. Both chronic bronchitis and breathlessness were significantly related to dust exposure. CONCLUSIONS: Although most quartz concentrations at the time of this study were currently below regulatory limits in the heavy clay industry, high exposures regularly occurred in specific processes and occasionally among most occupational groups. However, there are small risks of pneumoconiosis and respiratory symptoms in the industry, although frequency of pneumoconiosis is low in comparison to other quartz exposed workers. (+info)Selection of ganglioside GM1-binding peptides by using a phage library. (4/331)
Ganglioside Gal beta1 --> 3GalNAc beta1 --> 4(NeuAc alpha2 --> 3) Gal beta1 --> 4Glc beta1 -->1'Cer (GM1)-binding peptides were obtained from a phage-displayed pentadecapeptide library by an affinity selection. The selection processes were in situ-monitored by a quartz-crystal microbalance method, on which a ganglioside GM1 monolayer was transferred. After five rounds of biopanning, the DNA sequencing of 18 selected phages showed that only three individual clones were selected. The peptide sequences of the random region were found to be DFRRLPGAFWQLRQP, GWWYKGRARPVSAVA and VWRLLAPPFSNRLLP. Binding constants of these phage clones to the GM1 monolayer were 10(10) M(-1). Three synthetic pentadecapeptides inhibited the binding of cholera toxin B subunit to the GM1 monolayer with an IC50 of 24, 13 and 1.0 microM, respectively. These peptides will be useful for searching functional roles of ganglioside GMI. (+info)Effect of ionic strength on initial interactions of Escherichia coli with surfaces, studied on-line by a novel quartz crystal microbalance technique. (5/331)
A novel quartz crystal microbalance (QCM) technique was used to study the adhesion of nonfimbriated and fimbriated Escherichia coli mutant strains to hydrophilic and hydrophobic surfaces at different ionic strengths. This technique enabled us to measure both frequency shifts (Deltaf), i.e., the increase in mass on the surface, and dissipation shifts (DeltaD), i.e., the viscoelastic energy losses on the surface. Changes in the parameters measured by the extended QCM technique reflect the dynamic character of the adhesion process. We were able to show clear differences in the viscoelastic behavior of fimbriated and nonfimbriated cells attached to surfaces. The interactions between bacterial cells and quartz crystal surfaces at various ionic strengths followed different trends, depending on the cell surface structures in direct contact with the surface. While Deltaf and DeltaD per attached cell increased for nonfimbriated cells with increasing ionic strengths (particularly on hydrophobic surfaces), the adhesion of the fimbriated strain caused only low-level frequency and dissipation shifts on both kinds of surfaces at all ionic strengths tested. We propose that nonfimbriated cells may get better contact with increasing ionic strengths due to an increased area of contact between the cell and the surface, whereas fimbriated cells seem to have a flexible contact with the surface at all ionic strengths tested. The area of contact between fimbriated cells and the surface does not increase with increasing ionic strengths, but on hydrophobic surfaces each contact point seems to contribute relatively more to the total energy loss. Independent of ionic strength, attached cells undergo time-dependent interactions with the surface leading to increased contact area and viscoelastic losses per cell, which may be due to the establishment of a more intimate contact between the cell and the surface. Hence, the extended QCM technique provides new qualitative information about the direct contact of bacterial cells to surfaces and the adhesion mechanisms involved. (+info)Polymer-cushioned bilayers. I. A structural study of various preparation methods using neutron reflectometry. (6/331)
This neutron reflectometry study evaluates the structures resulting from different methods of preparing polymer-cushioned lipid bilayers. Four different techniques to deposit a dimyristoylphosphatidylcholine (DMPC) bilayer onto a polyethylenimine (PEI)-coated quartz substrate were examined: 1) vesicle adsorption onto a previously dried polymer layer; 2) vesicle adsorption onto a bare substrate, followed by polymer adsorption; and 3, 4) Langmuir-Blodgett vertical deposition of a lipid monolayer spread over a polymer-containing subphase to form a polymer-supported lipid monolayer, followed by formation of the outer lipid monolayer by either 3) horizontal deposition of the lipid monolayer or 4) vesicle adsorption. We show that the initial conditions of the polymer layer are a critical factor for the successful formation of our desired structure, i.e., a continuous bilayer atop a hydrated PEI layer. Our desired structure was found for all methods investigated except the horizontal deposition. The interaction forces between these polymer-supported bilayers are investigated in a separate paper (Wong, J. Y., C. K. Park, M. Seitz, and J. Israelachvili. 1999. Biophys. J. 77:1458-1468), which indicate that the presence of the polymer cushion significantly alters the interaction potential. These polymer-supported bilayers could serve as model systems for the study of transmembrane proteins under conditions more closely mimicking real cellular membrane environments. (+info)In vitro and in vivo tests for determination of the pathogenicity of quartz, diatomaceous earth, mordenite and clinoptilolite. (7/331)
The effects of samples of crystalline quartz, diatomaceous earth, mordenite and clinoptilolite were investigated in vitro (as concerns erythrocyte haemolysis and lactate dehydrogenase (LDH) release from peritoneal macrophages) and in vivo (on LDH, protein and phospholipids in rat bronchoalveolar lavage (BAL), and phospholipids in rat lung tissue). The respirable mineral samples were instilled intratracheally. Determinations in the BAL were carried out after 15, 60 and 180 days, and in the lung tissue after 90, 180 and 360 days. Quartz DQ and quartz FQ induced acute, subacute and chronic inflammation and progressive fibrosis. However, due to the Al2O3 contamination on the surface of the particles quartz FQ caused a delayed response in vivo. Diatomaceous earth produced acute/subacute inflammation that gradually became more moderate after 60 days. Clinoptilolite was inert, whereas the other zeolite sample, mordenite, was cytotoxic in vivo. The reason for this was presumably the needle and rod-shaped particles in the mordenite samples. The investigation revealed that different in vitro and in vivo methods canprovide valuable data concerning the pulmonary toxicity of minerals. (+info)Induction of superoxide in glioma cell line U87 stimulated with lipopolysaccharide and interferon-gamma: ESR using a new flow-type quartz cell. (8/331)
The production of superoxide and nitric oxide induced in U87 glioma treated with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) was examined by electron spin resonance (ESR) spectroscopy using a newly designed flow-type quartz cuvette without detaching cells from the culture plate. ESR spectra of 2,2,6, 6-tetramethyl-4-hydroxy-1-piperidinyloxy (TEMPOL) with U87 cells on a quartz culture plate were measured at 15 min intervals. The signal intensity of TEMPOL decreased in the presence of U87 cells at the pseudo-first order rate. The signal decay was accelerated in the U87 cells treated with LPS/IFN-gamma for 24 h, and was suppressed in the presence of superoxide dismutase and catalase. By the spin-trapping method, nitric oxide from U87 cells pretreated with LPS/IFN-gamma for 24 h was measured by the ESR, but only a weak signal of nitric oxide adducts was detected. Further, the nitrite and nitrate levels in the medium did not increase for 24 h. By the ESR measurement of cells on culture plates without detachment stress, it was found that the production of superoxide was induced by LPS/IFN-gamma, but that of nitric oxide was not, in U87 glioma cells. (+info)I'm sorry for any confusion, but "quartz" is not a medical term. Quartz is a mineral that is one of the most common minerals on Earth. It is found in many different types of rocks and is made up of silicon dioxide (SiO2). It is often used in electronics and watches because of its piezoelectric properties, which means it can generate an electric charge when subjected to pressure or stress.
It does not have any direct relation with medical field, although there are some Quartz based equipment like quartz crystal microbalance (QCM) sensors that are used in medical research for the detection of biomolecules and pathogens.
A Quartz Crystal Microbalance (QCM) is a type of physical analysis technique that uses the vibrations of a quartz crystal to measure changes in mass at a molecular or nanoscale level. When an alternating electrical field is applied to a quartz crystal, it causes the crystal to vibrate at a specific frequency. This phenomenon is known as the piezoelectric effect.
In QCM techniques, a thin film or material is deposited onto the surface of the quartz crystal, which changes its mass and therefore affects its vibrational frequency. By measuring the change in frequency before and after the deposition of the material, researchers can calculate the mass of the material that was added to the crystal's surface with high precision.
QCM techniques have a wide range of applications in research and industry, including the study of thin films, self-assembled monolayers, biosensors, and environmental monitoring. They are particularly useful for measuring changes in mass that occur on a very small scale, such as those associated with chemical reactions or biological interactions.
Silicosis is a lung disease caused by inhalation of crystalline silica dust. It is characterized by the formation of nodular lesions and fibrosis (scarring) in the upper lobes of the lungs, which can lead to symptoms such as shortness of breath, cough, and fatigue. The severity of the disease depends on the duration and intensity of exposure to silica dust. Chronic silicosis is the most common form and develops after prolonged exposure, while acute silicosis can occur after brief, intense exposures. There is no cure for silicosis, and treatment is focused on managing symptoms and preventing further lung damage.
Threshold Limit Values (TLVs) are defined by the American Conference of Governmental Industrial Hygienists (ACGIH) as "airborne concentrations of substances and physical agents to which most workers can be exposed day after day for a normal 8-hour workday and 40-hour workweek, without adverse health effects." TLVs are based on available scientific data and are designed to provide guidance to occupational health professionals in making decisions regarding safe levels of exposure to various workplace hazards.
TLVs are divided into three categories:
1. Time-weighted average (TWA): This is the average airborne concentration of a substance or physical agent to which a worker can be exposed for an 8-hour workday and 40-hour workweek, without experiencing adverse health effects.
2. Short-term exposure limit (STEL): This is the maximum concentration of a substance or physical agent to which a worker can be exposed for a short period of time (usually 15 minutes) without experiencing significant irritation, narcosis, or other acute toxic effects. STELs are intended to protect workers from brief, but potentially hazardous, exposures.
3. Ceiling limit (CL): This is the concentration of a substance or physical agent that should not be exceeded at any time during the workday. Ceiling limits are designed to protect workers from the potential acute effects of high-concentration exposures.
It's important to note that TLVs are guidelines and not regulatory standards, meaning they do not have the force of law. However, many organizations and companies use TLVs as a basis for establishing their own exposure limits and workplace safety policies.
Silicon dioxide is not a medical term, but a chemical compound with the formula SiO2. It's commonly known as quartz or sand and is not something that would typically have a medical definition. However, in some cases, silicon dioxide can be used in pharmaceutical preparations as an excipient (an inactive substance that serves as a vehicle or medium for a drug) or as a food additive, often as an anti-caking agent.
In these contexts, it's important to note that silicon dioxide is considered generally recognized as safe (GRAS) by the U.S. Food and Drug Administration (FDA). However, exposure to very high levels of respirable silica dust, such as in certain industrial settings, can increase the risk of lung disease, including silicosis.
In medical terms, "dust" is not defined as a specific medical condition or disease. However, generally speaking, dust refers to small particles of solid matter that can be found in the air and can come from various sources, such as soil, pollen, hair, textiles, paper, or plastic.
Exposure to certain types of dust, such as those containing allergens, chemicals, or harmful pathogens, can cause a range of health problems, including respiratory issues like asthma, allergies, and lung diseases. Prolonged exposure to certain types of dust, such as silica or asbestos, can even lead to serious conditions like silicosis or mesothelioma.
Therefore, it is important for individuals who work in environments with high levels of dust to take appropriate precautions, such as wearing masks and respirators, to minimize their exposure and reduce the risk of health problems.
Carbon inorganic compounds are chemical substances that contain carbon combined with one or more elements other than hydrogen. These compounds include oxides of carbon such as carbon monoxide (CO) and carbon dioxide (CO2), metal carbides like calcium carbide (CaC2) and silicon carbide (SiC), and carbonates like calcium carbonate (CaCO3) and sodium carbonate (Na2CO3).
Unlike organic compounds, which are based on carbon-hydrogen bonds, inorganic carbon compounds do not contain hydrocarbon structures. Instead, they feature carbon bonded to elements such as nitrogen, oxygen, sulfur, or halogens. Inorganic carbon compounds have diverse physical and chemical properties and play important roles in various industrial applications, as well as in biological systems.
Coal mining is the process of extracting coal from the ground. Coal is a fossil fuel that is formed from the accumulation and decomposition of plants over millions of years. It is primarily used as a source of energy for electricity generation, as well as for heating and industrial processes.
There are two main types of coal mining: surface mining and underground mining. Surface mining involves removing the soil and rock above the coal seam to access the coal, while underground mining involves sinking shafts and tunnels into the earth to reach the coal. Both methods have their own set of benefits and challenges, and the choice of which method to use depends on various factors such as the depth and location of the coal seam, the geology of the area, and environmental concerns.
Coal mining can be a dangerous occupation, with risks including accidents, explosions, and exposure to harmful dust and gases. As a result, it is essential that coal miners receive proper training and equipment to minimize these risks and ensure their safety. Additionally, coal mining has significant environmental impacts, including deforestation, habitat destruction, and water pollution, which must be carefully managed to minimize harm.
I'm sorry for any confusion, but "Polyvinylpyridine N-Oxide" is not a term that has a widely accepted medical definition. It is a chemical compound that is used in various industrial and laboratory applications, such as a polymerization initiator or a component in some types of membranes. However, it is not a term that is commonly used in medical diagnoses, treatments, or research.
If you have any questions about a specific medical condition or treatment, I would be happy to try to help you find an answer based on the information you do provide.
Pneumoconiosis is a group of lung diseases caused by inhaling dust particles, leading to fibrosis or scarring of the lungs. The type of pneumoconiosis depends on the specific dust inhaled. Examples include coal worker's pneumoconiosis (from coal dust), silicosis (from crystalline silica dust), and asbestosis (from asbestos fibers). These diseases are generally preventable by minimizing exposure to harmful dusts through proper engineering controls, protective equipment, and workplace safety regulations.
Silicon compounds refer to chemical substances that contain the element silicon (Si) combined with other elements. Silicon is a Group 14 semimetal in the periodic table, and it often forms compounds through covalent bonding. The most common silicon compound is silicon dioxide (SiO2), also known as silica, which is found in nature as quartz, sand, and other minerals.
Silicon can form compounds with many other elements, including hydrogen, oxygen, halogens, sulfur, nitrogen, and carbon. For example:
* Silanes (SiHn) are a series of silicon-hydrogen compounds where n ranges from 1 to 6.
* Silicones are synthetic polymers made up of alternating silicon and oxygen atoms with organic groups attached to the silicon atoms.
* Silicates are a class of minerals that contain silicon, oxygen, and one or more metal cations. They have a wide range of structures and uses, including as building materials, ceramics, and glass.
* Siloxanes are a group of compounds containing alternating silicon-oxygen bonds with organic groups attached to the silicon atoms.
Silicon compounds have various applications in industry, medicine, and daily life. For instance, silicones are used in medical devices such as breast implants, contact lenses, and catheters due to their biocompatibility and flexibility. Silicates are found in pharmaceuticals, cosmetics, and food additives. Silicon-based materials are also used in dental restorations, bone cement, and drug delivery systems.
Occupational air pollutants refer to harmful substances present in the air in workplaces or occupational settings. These pollutants can include dusts, gases, fumes, vapors, or mists that are produced by industrial processes, chemical reactions, or other sources. Examples of occupational air pollutants include:
1. Respirable crystalline silica: A common mineral found in sand, stone, and concrete that can cause lung disease and cancer when inhaled in high concentrations.
2. Asbestos: A naturally occurring mineral fiber that was widely used in construction materials and industrial applications until the 1970s. Exposure to asbestos fibers can cause lung diseases such as asbestosis, lung cancer, and mesothelioma.
3. Welding fumes: Fumes generated during welding processes can contain harmful metals such as manganese, chromium, and nickel that can cause neurological damage and respiratory problems.
4. Isocyanates: Chemicals used in the production of foam insulation, spray-on coatings, and other industrial applications that can cause asthma and other respiratory symptoms.
5. Coal dust: Fine particles generated during coal mining, transportation, and handling that can cause lung disease and other health problems.
6. Diesel exhaust: Emissions from diesel engines that contain harmful particulates and gases that can cause respiratory and cardiovascular problems.
Occupational air pollutants are regulated by various government agencies, including the Occupational Safety and Health Administration (OSHA) in the United States, to protect workers from exposure and minimize health risks.
Inhalation exposure is a term used in occupational and environmental health to describe the situation where an individual breathes in substances present in the air, which could be gases, vapors, fumes, mist, or particulate matter. These substances can originate from various sources, such as industrial processes, chemical reactions, or natural phenomena.
The extent of inhalation exposure is determined by several factors, including:
1. Concentration of the substance in the air
2. Duration of exposure
3. Frequency of exposure
4. The individual's breathing rate
5. The efficiency of the individual's respiratory protection, if any
Inhalation exposure can lead to adverse health effects, depending on the toxicity and concentration of the inhaled substances. Short-term or acute health effects may include irritation of the eyes, nose, throat, or lungs, while long-term or chronic exposure can result in more severe health issues, such as respiratory diseases, neurological disorders, or cancer.
It is essential to monitor and control inhalation exposures in occupational settings to protect workers' health and ensure compliance with regulatory standards. Various methods are employed for exposure assessment, including personal air sampling, area monitoring, and biological monitoring. Based on the results of these assessments, appropriate control measures can be implemented to reduce or eliminate the risks associated with inhalation exposure.
Biosensing techniques refer to the methods and technologies used to detect and measure biological molecules or processes, typically through the use of a physical device or sensor. These techniques often involve the conversion of a biological response into an electrical signal that can be measured and analyzed. Examples of biosensing techniques include electrochemical biosensors, optical biosensors, and piezoelectric biosensors.
Electrochemical biosensors measure the electrical current or potential generated by a biochemical reaction at an electrode surface. This type of biosensor typically consists of a biological recognition element, such as an enzyme or antibody, that is immobilized on the electrode surface and interacts with the target analyte to produce an electrical signal.
Optical biosensors measure changes in light intensity or wavelength that occur when a biochemical reaction takes place. This type of biosensor can be based on various optical principles, such as absorbance, fluorescence, or surface plasmon resonance (SPR).
Piezoelectric biosensors measure changes in mass or frequency that occur when a biomolecule binds to the surface of a piezoelectric crystal. This type of biosensor is based on the principle that piezoelectric materials generate an electrical charge when subjected to mechanical stress, and this charge can be used to detect changes in mass or frequency that are proportional to the amount of biomolecule bound to the surface.
Biosensing techniques have a wide range of applications in fields such as medicine, environmental monitoring, food safety, and biodefense. They can be used to detect and measure a variety of biological molecules, including proteins, nucleic acids, hormones, and small molecules, as well as to monitor biological processes such as cell growth or metabolism.
Aluminum silicates are a type of mineral compound that consist of aluminum, silicon, and oxygen in their chemical structure. They are often found in nature and can be categorized into several groups, including kaolinite, illite, montmorillonite, and bentonite. These minerals have various industrial and commercial uses, including as fillers and extenders in products like paper, paint, and rubber. In the medical field, certain types of aluminum silicates (like bentonite) have been used in some medicinal and therapeutic applications, such as detoxification and gastrointestinal disorders. However, it's important to note that the use of these minerals in medical treatments is not widely accepted or supported by extensive scientific evidence.
Occupational exposure refers to the contact of an individual with potentially harmful chemical, physical, or biological agents as a result of their job or occupation. This can include exposure to hazardous substances such as chemicals, heavy metals, or dusts; physical agents such as noise, radiation, or ergonomic stressors; and biological agents such as viruses, bacteria, or fungi.
Occupational exposure can occur through various routes, including inhalation, skin contact, ingestion, or injection. Prolonged or repeated exposure to these hazards can increase the risk of developing acute or chronic health conditions, such as respiratory diseases, skin disorders, neurological damage, or cancer.
Employers have a legal and ethical responsibility to minimize occupational exposures through the implementation of appropriate control measures, including engineering controls, administrative controls, personal protective equipment, and training programs. Regular monitoring and surveillance of workers' health can also help identify and prevent potential health hazards in the workplace.
Adsorption is a process in which atoms, ions, or molecules from a gas, liquid, or dissolved solid accumulate on the surface of a material. This occurs because the particles in the adsorbate (the substance being adsorbed) have forces that attract them to the surface of the adsorbent (the material that the adsorbate is adhering to).
In medical terms, adsorption can refer to the use of materials with adsorptive properties to remove harmful substances from the body. For example, activated charcoal is sometimes used in the treatment of poisoning because it can adsorb a variety of toxic substances and prevent them from being absorbed into the bloodstream.
It's important to note that adsorption is different from absorption, which refers to the process by which a substance is taken up and distributed throughout a material or tissue.
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.
Quartz
Quartz inversion
Quartz-dolerite
Quartz monzonite
Quartz Gulch
Quartz News
Quartz Lake
USS Quartz
Quartz fiber
Quartz monzogabbro
Quartz-porphyry
Quartz Hills
Quartz Mountains
Quartz (publication)
Rolling Quartz
Automatic quartz
Quartz Creek
Phantom quartz
Quartz Peak
Quartz gecko
Quartz Composer
Quartz gabbro
Quartz, California
Quartz thermometer
Quartz arenite
Quartz 2D
Quartz (scheduler)
Quartz crisis
Quartz (disambiguation)
Quartz diorite
Quartz 2D - Wikipedia
Quartz - Wikipedia
Definition of Quartz | PCMag
quartz monzonite
November News...It's Quartz Month!!!!
Listeners you know - George Quartz | Last.fm
Quartz - Salar - Q4028
Rose quartz jewelry
Kleber & Associates Named Agency of Record by Vadara Quartz Surfaces
Apatite-(CaF) Quartz Image
New Launch | Quartz 2023 | Wilsonart
Valentine's Day Gift Rose Quartz Necklace Pink Necklace - Etsy
PriceGrabber - Watches, Stainless Steel, Quartz, Stainless Steel Watches
Quartz Countertops St. Louis | Caesarstone US
Quartz Rings - Ernest Jones
The 10 Best Quartz Countertop Companies Near Me
Rose Quartz - International Colored Gemstone Association
Quartz is back! - Black Sabbath Online
Quartz Pullover (Crochet) - Lion Brand Yarn
AT&T Fiber Internet in Quartz Hill, CA - Fast Gigabit Internet
Lubricity of gold nanocrystals on graphene measured using quartz crystal microbalance | Scientific Reports
quartz wedge : Dictionary / Wörterbuch (BEOLINGUS, TU Chemnitz)
NuGet Gallery | Quartz 2.6.1
Flat Quartz Angular Rate Sensor Using Hammer-Headed Double-T Structure
4030 Pebble: Gray Quartz Countertop | Caesarstone US
Hematoid Quartz Pebble
Quartz Clusters | Brookstone
Rose Quartz23
- Often called the 'love stone ,' Rose Quartz is said to open the heart chakra to all forms of love: self love, family love, platonic love and romantic love. (ka-gold-jewelry.com)
- Rose quartz has been attributed the power to help with family reconciliations and ease overwhelming or unreasonable guilt. (ka-gold-jewelry.com)
- Rose quartz is found in Madagascar, Brazil, India, Germany and several parts of the U.S.A. (ka-gold-jewelry.com)
- Rose Quartz is in Fashion! (gemstone.org)
- Rose Quartz is having a moment of glory in the jewelry world, and its popularity seems to be here to stay. (gemstone.org)
- Rose Quartz has endured as a top fashion color well into 2017, and it remains on the list of Pantone's top ten colors for 2017 - it is also referred to as "dusty spring. (gemstone.org)
- A recent article on fashionista.com says, "you would have to be colorblind to question whether we are knee-deep in a Rose-Quartz-everything era. (gemstone.org)
- All of this publicity is boosting the reputation of Rose Quartz, which was long overlooked in favor of more saturated colored gemstones. (gemstone.org)
- Morganite also enjoyed a moment due to the popularity of pink, and it is more transparent than Rose Quartz, with a higher color saturation. (gemstone.org)
- According to Bangkok gem dealer Navneet Agarwal, from Navneet Gems, the demand for Morganite resulted in a surge in price that has people turning to Rose Quartz instead. (gemstone.org)
- This, he says, paved the way for the demand for Rose Quartz, which is priced reasonably for standard sizes. (gemstone.org)
- Rose Quartz has a comparable pink color, but softer and more cloudy in appearance than Morganite - something that is preferred in jewelry at the moment. (gemstone.org)
- Rose Quartz is also slightly softer than other pink gems - 7 on the Moh's scale compared to Morganite's 7.5 to 8 and Pink Sapphire's 9 - but it is more abundant, which makes it more affordable, and it is a beautiful gemstone in its own right. (gemstone.org)
- The primary element in Rose Quartz is titanium, but mineralogists believe that iron and manganese also play a role in its color. (gemstone.org)
- 1. Chain with stations of rose quartz and citrine, by Marco Bicego. (gemstone.org)
- 2. Roberto Coin cocktail necklace in 18k rose gold with a doublet of rose quartz and mother of pearl with diamonds. (gemstone.org)
- In terms of lore, Rose Quartz is the gemstone of love. (gemstone.org)
- In addition to being a January birthstone, Rose Quartz is also the gemstone of the fifth wedding anniversary. (gemstone.org)
- Rose Quartz has a delicate pink color that ranges from nearly white to a deep rose-pink. (gemstone.org)
- The most appealing color typically occurs in larger sizes, and small Rose Quartz specimens with good color tend to be rare. (gemstone.org)
- In ancient times, Rose Quartz was used to carve crystal balls: perhaps to induce a rosy outlook? (gemstone.org)
- These genuine rose quartz chilling stones are the perfect addition to any girls' cocktail night. (firebox.com)
- Looks like Rose quartz chilling stones doesn't have any reviews yet. (firebox.com)
Mineral11
- Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). (wikipedia.org)
- Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. (wikipedia.org)
- Quartz is the mineral defining the value of 7 on the Mohs scale of hardness, a qualitative scratch method for determining the hardness of a material to abrasion. (wikipedia.org)
- Quartz monzonite differs from granodiorite by containing more alkali feldspar , usually more biotite and less hornblende , and oligoclase instead of andesine as the plagioclase mineral. (britannica.com)
- Quartz is a naturally occurring mineral on earth. (caesarstoneus.com)
- Quartz is a member of the silicates, the largest of all mineral groups, and is composed of silicon and oxygen. (gemstone.org)
- The researchers used quartz because it is the simplest and most common silicate mineral. (newscientist.com)
- Quartz is the second most common mineral in the earth's continental crust. (processregister.com)
- Quartz is actually a mineral, not a stone, although similar because minerals are the fundamental components of rock. (granitetransformations.com)
- The second most abundant mineral on our planet's crust, quartz is one of the hardest minerals on Earth. (granitetransformations.com)
- The success of optically stimulated luminescence (OSL) dating relies to a large extent on suitable characteristics of the analysed mineral, in this case quartz. (lu.se)
Crystals9
- He supported this idea by saying that quartz is found near glaciers in the Alps, but not on volcanic mountains, and that large quartz crystals were fashioned into spheres to cool the hands. (wikipedia.org)
- Efforts to synthesize quartz began in the mid-nineteenth century as scientists attempted to create minerals under laboratory conditions that mimicked the conditions in which the minerals formed in nature: German geologist Karl Emil von Schafhäutl (1803-1890) was the first person to synthesize quartz when in 1845 he created microscopic quartz crystals in a pressure cooker. (wikipedia.org)
- By the 1930s, the electronics industry had become dependent on quartz crystals. (wikipedia.org)
- After the war, many laboratories attempted to grow large quartz crystals. (wikipedia.org)
- By the 1950s, hydrothermal synthesis techniques were producing synthetic quartz crystals on an industrial scale, and today virtually all the quartz crystal used in the modern electronics industry is synthetic. (wikipedia.org)
- Purple crystal of fluorapatite on slightly smoky quartz crystals. (webmineral.com)
- Quartz countertops consist of about 90% crushed crystals and 10% poly-resin materials. (caesarstoneus.com)
- Depending on the geological factors contributing to its formation and the impurities present in the crystals, gem quality Quartz can be found in many different colors and varieties. (gemstone.org)
- They found that the broken crystals on the surface of quartz can react with water to form molecular oxygen and other reactive oxygen species, such as hydrogen peroxide. (newscientist.com)
Respirable quartz1
- No measurable levels were noted of respirable quartz, or total or respirable cristobalite (14464461). (cdc.gov)
Countertop materials5
- Durable countertop materials, such as quartz, will serve the home for a long period. (caesarstoneus.com)
- In comparison to other countertop materials, quartz tops the list when it comes to durability. (caesarstoneus.com)
- Just what makes quartz countertops the most durable in comparison to other countertop materials? (caesarstoneus.com)
- Granite Transformations and our Portland granite countertop installation specialists can design quartz surfaces to mimic these other popular countertop materials. (granitetransformations.com)
- Quartz is a naturally occurring material, but quartz countertops are manmade and require a different manufacturing process than other natural stone countertop materials. (granitetransformations.com)
Countertops are made3
- The countertops are made by grinding natural quartz into dust. (caesarstoneus.com)
- As we mentioned, quartz countertops are made with approximately 90% natural quartz, with the rest being resins and polymers. (caesarstoneus.com)
- Quartz countertops are made by combining small particles of quartz with natural and recycled materials. (granitetransformations.com)
Durability of quartz2
- The durability of quartz countertops ensures that users will continue to enjoy the countertops over the years. (caesarstoneus.com)
- If you love the durability of quartz but prefer the look of marble, granite, or concrete, you have choices. (granitetransformations.com)
Wilsonart8
- To download the Wilsonart Quartz Warranty (pdf), click here . (wilsonart.com)
- Wilsonart LLC ("Wilsonart") provides a Limited 10 year Warranty to the original owners (defined as first occupant after installation) of the installed Wilsonart® Quartz surface ("Product") that the Product will be free from manufacturing defects for 10 years from the date of purchase by the original purchaser. (wilsonart.com)
- is used for its intended purpose, and is maintained and used in accordance with the Wilsonart Quartz Care and Maintenance Guide. (wilsonart.com)
- 1. This warranty covers Product that has been purchased from an authorized Wilsonart Quartz fabricator and installed by an authorized Wilsonart Quartz installer. (wilsonart.com)
- 3. In the event that no record of your warranty is on file, you must provide proof of purchase in the form of a copy of your original receipt or invoice showing the name of the Owner and Wilsonart Quartz Authorized Dealer. (wilsonart.com)
- What inspired the new Wilsonart® Quartz launch? (wilsonart.com)
- The latest designs from Wilsonart® Quartz have arrived with design possibilities that will capture your imagination. (wilsonart.com)
- From snow resting on frigid branches to ethereal clouds on the sea horizon, the new collection from Wilsonart® Quartz reflects exquisite scenes of nature like never before. (wilsonart.com)
18801
- In 1880, Jaques and Pierre Curie discovered the piezoelectric properties that would later be used in quartz movements. (klockit.com)
World's1
- The world's first quartz movement was invented in 1927 by Warren Marrison and J.W. Horton. (klockit.com)
Graphene1
- In order to test recently predicted ballistic nanofriction (ultra-low drag and enhanced lubricity) of gold nanocrystals on graphite at high surface speeds, we use the quartz microbalance technique to measure the impact of deposition of gold nanocrystals on graphene. (nature.com)
Crystal13
- both vein quartz and rock crystal were knapped as part of the lithic technology of the prehistoric peoples. (wikipedia.org)
- While jade has been since earliest times the most prized semi-precious stone for carving in East Asia and Pre-Columbian America, in Europe and the Middle East the different varieties of quartz were the most commonly used for the various types of jewelry and hardstone carving, including engraved gems and cameo gems, rock crystal vases, and extravagant vessels. (wikipedia.org)
- George Washington Pierce designed and patented quartz crystal oscillators in 1923. (wikipedia.org)
- (1) See quartz crystal . (pcmag.com)
- This paper report on a newly designed, flat, angular- rate sensor consisting of a Hammer Headed, Double-T Structure, vibrating element made from a single quartz crystal. (sae.org)
- Our optimized sensor's performance is highly reliable because the resonator uses the vibrations in only one plane of a monolithic quartz crystal that is highly stable under operating conditions, especially temperature changes. (sae.org)
- The performance of the newly developed quartz, angular-rate sensor is highly reproducible by using one of the most stable materials known, the single quartz crystal. (sae.org)
- Hematoid Quartz is an unusual and powerful crystal. (chalicewell.org.uk)
- The quartz contains hematite and this crystal was an amulet of protection in ancient Eqypt. (chalicewell.org.uk)
- Battery-operated movement that sends an electrical signal to the quartz crystal. (klockit.com)
- The quartz crystal creates a precise frequency enabling the quartz movement to keep time. (klockit.com)
- The battery sends an electrical current through the quartz crystal. (klockit.com)
- The instrument is from Q-Sense fitted with E4 and E1 module and is able to collect, both the dissipation and the resonance frequency of a quartz crystal. (lu.se)
Silica1
- QYLURQPHQWDO FDUFLQRJHQV The IARC 0RQRJUDSKV on the evaluation of carcinogenic risks to humans published in 1997 conclude that PCDD ("dioxin") and crystalline silica inhaled in the form of quartz or cristobalite from occupational sources are carcinogenic to humans. (who.int)
Warren Marrison1
- Warren Marrison created the first quartz oscillator clock based on the work of Cady and Pierce in 1927. (wikipedia.org)
Surfaces5
- Kleber & Associates (K&A), a full-service marketing and public relations agency, has been selected as the agency of record by Vadara Quartz Surfaces (Vadara), a world-class manufacturer of premium quartz surfaces. (prweb.com)
- The agency's efforts also expanded on the stain resistance and wellness benefits that quartz surfaces feature with nonporous attributes that are not available in natural stone products. (prweb.com)
- Premier Surfaces, Inc. is a provider of granite, marble and quartz products. (processregister.com)
- Quartz surfaces work well as kitchen countertops, bathroom vanities, tub and shower surrounds, and tub-to-shower conversions. (granitetransformations.com)
- Unlike authentic granite and concrete surfaces, quartz is nonporous and doesn't need to be sealed year after year. (granitetransformations.com)
Nonporous2
- Our quartz slabs are handcrafted, maintenance-free, nonporous, scratch- and heat-resistant, and guaranteed with a Lifetime Limited Warranty. (granitetransformations.com)
- White may seem like an impractical color to go with, especially for a kitchen countertop, but because of its nonporous surface, white quartz won't absorb messy spills and won't stain. (granitetransformations.com)
Synthetic1
- Universal Quartz Inc. is a manufacturer of synthetic quartz material used in the production of integrated circuits on silicon wafers. (processregister.com)
Stones1
- However, quartz countertops are engineered stones. (caesarstoneus.com)
Colors1
- Quartz offers a wide variety of colors and styles along with incredible durability, so it's perfect for most design aesthetics. (granitetransformations.com)
India1
- Given the India audience, Quartz is launching its first non-U.S.-centric site, Quartz India, in June, partnered with scroll.in. (niemanlab.org)
Bulova1
- This timeless piece from Bulova utilizes quartz movement for premium accuracy and is also water resistant, making it great for everyday wear. (yahoo.com)
White quartz1
- White quartz countertops are a wonderful way to brighten a room and make it seem less cluttered. (granitetransformations.com)
Premium quartz1
- However, homeowners opting for quartz will want to ensure they select a premium quartz countertop manufacturer like Caesarstone , to ensure they are getting the best quality product possible. (caesarstoneus.com)
Material3
- Quartz is the most common material identified as the mystical substance maban in Australian Aboriginal mythology. (wikipedia.org)
- Made from a durable quartz composite material, this sink can handle the toughest daily kitchen tasks with ease. (bedbathandbeyond.com)
- Quartz Technology, Inc. is engaged in developing raw quartz material. (processregister.com)
Varieties3
- There are many different varieties of quartz, several of which are classified as gemstones. (wikipedia.org)
- Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. (wikipedia.org)
- This blushing gemstone is one of the most desirable varieties of quartz. (ka-gold-jewelry.com)
Naturally2
- Quartz is perfect for wet areas because it's naturally resistant to mold and mildew. (granitetransformations.com)
- Quartz becomes a durable and eco-friendly surface when combined with recycled materials, naturally occurring stone, and our polymer resin, ForeverSeal®, making it an excellent countertop surface. (granitetransformations.com)
Utilizes2
- It utilizes quartz movement and is water resistant, making it great for everyday wear. (pricegrabber.com)
- It utilizes quartz movement and is water resistant. (pricegrabber.com)
Fiber3
- Quality Quartz Engineering designs & manufactures solid quartz products for the semiconductor, fiber optic and lighting industries. (processregister.com)
- To evaluate the dislocation resistance of the quartz fiber post/cement/dentin interface after different adhesion strategies. (bvsalud.org)
- GAllBondSE±C&B- AllBondSE ±C&B with a quartz fiber post. (bvsalud.org)
Granite2
- Granite countertops are partly composed of quartz, but pure quartz slabs can't be quarried like granite is. (granitetransformations.com)
- As one of the strongest minerals in the world, quartz has unmatched durability when compared to granite and concrete. (granitetransformations.com)
Https1
- Flat Quartz Angular Rate Sensor Using Hammer-Headed Double-T Structure," SAE Technical Paper 2002-01-1077, 2002, https://doi.org/10.4271/2002-01-1077 . (sae.org)
California1
- Mark Thiemens at the University of California, San Diego, and his colleagues ground up quartz rock and exposed it to water under chemical conditions similar to those on Earth prior to high levels of oxygen. (newscientist.com)
Specialty2
- Choose from quartz clock movements like time-only , chiming and pendulum , to atomic clock movements and other specialty clock movements. (klockit.com)
- Momentive Performance Materials Inc. produces silicones and silicone derivatives and a global leader in the development and manufacture of products derived from quartz & specialty ceramics. (processregister.com)
Stainless Steel1
- Add some team spirit to your watch collection with this Howard Bison Stainless Steel Quartz Watch. (yahoo.com)
Found2
- Occasionally a star pink Quartz is found, when inclusions of rutile are dense enough to create a weak six-rayed star phenomenon. (gemstone.org)
- And yet, before its second birthday, Quartz has found a niche. (niemanlab.org)
Hardness1
- On the Mohs Hardness Test Scale, quartz ranks at 7 out of 10, making it even harder than a steel file, glass, or even a sharp knife. (caesarstoneus.com)
Brazil1
- however, World War II disrupted the supplies from Brazil, so nations attempted to synthesize quartz on a commercial scale. (wikipedia.org)
Framework2
- Quartz 2D is the native two-dimensional graphics rendering API for macOS and iOS platforms, part of the Core Graphics framework. (wikipedia.org)
- With the release of Mac OS X 10.2, marketing attention focused on Quartz Extreme , the composition layer, leaving the term "Quartz" to refer to the Core Graphics framework or just its 2D renderer. (wikipedia.org)
Surface3
- Fessenden Hall Of Delaware, Inc. specializes in providing quartz, laminated & hard surface materials for countertops. (processregister.com)
- Gray quartz countertops are becoming a more popular choice for countertops, giving any kitchen or bathroom surface an elegant look. (granitetransformations.com)
- To clean our quartz countertops, all you need to do is wipe the surface with soapy water! (granitetransformations.com)
Atlantic Media4
- Fast innovator Atlantic Media wrote the playbook for Quartz. (niemanlab.org)
- His fellow co-conspirator at Atlantic Media and with Quartz, Scott Havens , just joined the soon-to-be-new Time Inc. as senior vice president for digital, after five years at Atlantic. (niemanlab.org)
- That's a confluence of influence that speaks to the thinking and execution at Quartz and elsewhere within Atlantic Media. (niemanlab.org)
- Quartz , die neue, rein digitale Wirtschaftspublikation von Atlantic Media, dem Publisher des renommierten Monatsmagazins The Atlantic, ist beeindruckend. (neunetz.com)
Shade1
- A supple ashen shade blended with darker-toned quartz chips, creating a clean aesthetic. (caesarstoneus.com)
Resistance1
- Based on this study design, it may be concluded that adhesion strategies showed different results of quartz post dislocation resistance. (bvsalud.org)
Products1
- The price was 6,000 for quartz calacatta Verona.If I went to an MSI store with their products, would their fabrication be less? (gardenweb.com)
Collection2
- This Invicta watch from the Angel collection holds a Quartz movement' and it f. (pricegrabber.com)
- This Invicta watch from the Angel collection holds a Quartz movement" and it features a sturdy steel case. (pricegrabber.com)
Davis1
- Davis, M. City of quartz: imagining the future of Los Angeles . (bvs.br)
Context1
- Because Quartz 2D is one of several Quartz Technologies, the term "Quartz" by itself must be taken in context. (wikipedia.org)
Characteristics4
- Previous OSL dating of Quaternary sediments in Scandinavia has shown that quartz characteristics vary widely across the region, resulting in dating studies with varied success. (lu.se)
- The aim of this study is to provide an overview of quartz luminescence characteristics in Sweden and Norway, evaluate their effect on dating results and discuss the underlying causes of their variability. (lu.se)
- A qualitative assessment of luminescence signal characteristics of quartz from Late Quaternary sediment deposits, from a range of geological and geographical settings, has been made by re-analysing data. (lu.se)
- A qualitative assessment of luminescence signal characteristics of quartz from Late Quaternary sediment deposits, from a range of geological and geographical settings, has been made by re-analysing data from samples previously dated at the Lund Luminescence Laboratory, Sweden. (lu.se)