The short version of Sublimation fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-05-27 and is reviewed periodically as new material appears.
The physics of lyophilization depends on phase boundaries and heat and mass transfer. During primary drying, heat supplied to the product must equal the latent heat of sublimation, while water vapor moves through the drying cake to the condenser. If shelf temperature or pressure is set too high, the ice front can exceed the collapse temperature, causing meltback or pore collapse. If conditions are too cold, drying slows and costs rise. Formulation excipients, vial geometry, and freezing rate alter these limits.
Equipment for lyophilization includes a vacuum chamber, temperature-controlled shelves, a condenser, and a vacuum pump. A refrigeration system cools the shelves and condenser below the product's freezing point. Process monitoring often uses Pirani and capacitance manometers, thermocouples, and resistance sensors. Cycle development balances product quality with time and energy use. Some products are annealed during freezing to improve crystallization of bulking agents. Open questions remain about scaling cycles between laboratory, pilot, and production freeze-dryers.
Analytical methods for lyophilized solids must account for the low moisture content and the fragile cake. Karl Fischer titration is widely used for water content, while near-infrared spectroscopy can measure moisture non-destructively in sealed containers. X-ray diffraction and modulated differential scanning calorimetry help identify crystalline or amorphous phases. Residual solvent analysis may be needed if organic solvents were used during formulation. The combination of these methods supports batch release and long-term stability assessment.
Lyophilized products are typically stored as sealed solids in vials or syringes. Moisture ingress is a major concern because many dried cakes are hygroscopic and can lose stability when exposed to humid air. Storage temperature depends on the formulation; some products are kept refrigerated, while others are stable at room temperature. Container closure integrity and headspace moisture are often monitored. Light protection may also be required for some photosensitive materials.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | Freeze-drying; lyophilisation; cryodesiccation | Regional spelling and historical terms. |
| Primary drying pressure | 0.05-0.5 mbar (5-50 Pa) | Kept below the triple point of water; product-specific. |
| Shelf temperature range | -40 to +40 °C | Freezing, primary, and secondary stages use different set points. |
| Cycle duration | 12-72 hours | Depends on fill volume, formulation, and equipment. |
| Condenser temperature | -50 to -80 °C | Must remain below the product's ice temperature. |
The process generally proceeds in three stages: freezing, primary drying, and secondary drying. During freezing, controlled cooling converts water into ice and may also crystallize or vitrify solutes. In primary drying, the pressure is lowered below the triple point, and heat is supplied so ice sublimes directly to vapor. Secondary drying removes water that remains bound to the solid matrix, yielding a low final water content. Product temperature must stay below the collapse or glass transition temperature to maintain structure. Cycle design therefore balances shelf temperature, chamber pressure, and time.
Freeze-drying is used for materials whose activity or structure depends on low temperature and low water content. Examples include certain biologics, diagnostic reagents, starter cultures, coffee, and porous inorganic precursors. The dried product forms a cake whose porosity aids rapid wetting and dissolution. Main drawbacks are high energy use, long cycle times, and sensitivity to formulation and equipment variation. Questions remain about how freezing rates and ice morphology affect batch uniformity, especially when moving from laboratory to production scale.
Regulatory expectations for lyophilized products focus on consistent manufacture and documented stability. Batches are often monitored for moisture, appearance, potency, and sterility where applicable. Process parameters such as shelf temperature, chamber pressure, and drying time are recorded and controlled within validated ranges. Open questions remain about how best to predict long-term stability from short accelerated studies, especially for complex biologics. Variations in freezing rate and ice crystal size can produce differences that are not always visible but may affect performance.
After drying, a lyophilized product is usually sealed under vacuum or an inert gas to limit moisture uptake. Residual water content is measured because small changes can alter chemical stability and cake appearance. Storage temperature depends on the material; many biological products are kept at 2–8 °C, while some require −20 °C or colder. Exposure to ambient humidity during handling can cause the porous solid to absorb water and collapse. Container closures and stoppers are therefore selected for low moisture transmission and compatibility.
Secondary drying removes bound water that remains after ice sublimation. Shelf temperature is raised gradually while pressure remains low, reducing water content to a target range. Over-drying can cause brittleness or electrostatic issues, while under-drying affects stability. The endpoint is often judged by pressure rise tests, temperature measurements, or water content analysis. Scale-up depends on matching heat and mass transfer across equipment sizes. Small changes in shelf temperature or pressure can alter cycle length substantially.
Lyophilization, or freeze-drying, removes water from a material by freezing it and then lowering pressure so ice changes directly to vapor. The process relies on sublimation, the phase transition from solid to gas without an intervening liquid state. It is used for heat-sensitive materials that would degrade in conventional drying. The three stages are freezing, primary drying, and secondary drying, each with distinct temperature and pressure requirements. In practice, cycle design balances these variables.
Although some worms have eyes (e.g. leeches, some polychaetes), earthworms do not. However, they do have specialized photosensitive cells called "light cells of Hess". These photoreceptor cells have a central intracellular cavity (phaosome) filled with microvilli. As well as the microvilli, there are several sensory cilia in the which are structurally independent of the microvilli. The photoreceptors are distributed in most parts of the epidermis, but are more concentrated on the back and sides of the worm. A relatively small number occur on the ventral surface of the first segment. They are most numerous in the prostomium, and reduce in density in the first three segments; they are very few in number past the third segment.
=== Subsidy reforms and economic policies === The Iranian government has, at times, cut subsidies on essential goods or tried to reform the subsidy system to address budget deficits. These changes often lead to sudden price hikes in food items. The subsidies have been replaced with in-kind transfers. For several decades, the Iranian government has regulated the prices of over 20 essential goods. These prices, known as administered prices, are determined by the Consumer and Producer Protection Organization (CPPO) in collaboration with the Iranian Parliament. The CPPO sets consumer prices below both reference (border) prices and producer prices, with the government budget absorbing the resulting financial gap. In 2007, food subsidies represented approximately 2.8 percent of Iran's GDP. These subsidies are primarily directed toward cereals, which account for 50 percent of the total, while other basic food items such as sugar, cooking oils, and baby formulas comprise an additional 25 percent. The remaining 25 percent is allocated to various goods, including paper, agricultural machinery, fertilizers, and pharmaceuticals. As part of the Targeted Subsidies Reform, the government raised bread prices by as much as 25 percent in December 2010. After this adjustment, the CPPO prohibited any further price increases and instituted regular market inspections to prevent public unrest that could arise from inflationary pressures.
In June 2025, President Trump brokered a peace deal between the Democratic Republic of Congo and Rwanda, with the U.S. getting "a lot of mineral rights". This potentially brings to an end a 30+ year conflict dating back to the 1994 Rwanda genocide. Each country had accused the other of financing and supporting rebel groups. On June 27, in a deal signed in the White House, each country pledged to end such support, allow the return of refugees, and create a joint security coordination mechanism aimed at resolving disputes. An estimated 6 million persons have died in this conflict, and Trump said that this deal ends "one of the worst wars anyone's ever seen". A critic said, "It risks reducing peace to a transactional exchange. Minerals are only one driver of conflict." Secretary of State Marco Rubio said, "This is an important moment after 30 years of war. President Trump is a president of peace. He really does want peace. He prioritizes it above all else." A former prime minister of the DR Congo, Joseph Kabila, expressed skepticism of the peace deal, saying that it was "nothing more than a trade agreement".
== Procedure == When performing RK, incisions are made with a diamond knife. The incisions relax the steep central cornea in patients with myopia in order to achieve a decreased need for correction. The original technique – consisting of incisions from periphery to center – was called the "Russian technique", while the later advances of performing controlled incision from center to periphery was called the "American technique". RK may be performed with different types, numbers, and patterns of incisions. Typically, between 4 and 24 radial incisions are made in a number of patterns and orientations based on refractive errors, surgeon style and surgeon training. RK with 8 incisions is most common. Incisions that penetrate only the superficial corneal stroma are less effective than those reaching deep into the cornea, and consequently, incisions are made quite deep. One study cites incisions made to a depth equivalent to the thinnest of four corneal-thickness measurements made near the center of the cornea. Other sources cite surgeries leaving 20 to 50 micrometres of corneal tissue unincised (roughly equivalent to 90% of corneal depth, based on thickness norms).
==== Diverse food sourcing ==== Diverse sourcing of food, such as through international trade, is a key strategy for building agrifood systems' resilience because it buffers the food supply against shocks and stresses. The volume of agrifood trade more than doubled between 2000 and 2024. Although international trade buffers against domestic shocks, it increases exposure to external shocks and can itself become a channel of shock transmission, therefore having diverse international trade partners is key. Enhancing diversity in terms of commodities is also essential for ensuring the supply of food necessary for healthy diets. However, evidence on the diversity of food supply in terms of domestic production, imports and stocks reveal that the potential of international trade is not equally well exploited in all countries. Low-income countries, such as in sub-Saharan Africa, are among those with the lowest diversity of imports as the food supply is mostly determined by what is produced for the domestic market.
Sources: en.wikipedia.org
Sometimes it seems that elaborate plans and statistics are made to prove what is commonplace knowledge to the mere collector, such as that hunting parties often travel more or less in circles. David Lack's studies on population ecology sought to find the processes involved in the regulation of population based on the evolution of optimal clutch sizes. He concluded that population was regulated primarily by density-dependent controls, and also suggested that natural selection produces life-history traits that maximize the fitness of individuals. Others, such as Wynne-Edwards, interpreted population regulation as a mechanism that aided the "species" rather than individuals. This led to widespread and sometimes bitter debate on what constituted the "unit of selection". Lack also pioneered the use of many new tools for ornithological research, including the idea of using radar to study bird migration. Birds were also widely used in studies of the niche hypothesis and Georgii Gause's competitive exclusion principle. Work on resource partitioning and the structuring of bird communities through competition were made by Robert MacArthur. Patterns of biodiversity also became a topic of interest. Work on the relationship of the number of species to area and its application in the study of island biogeography was pioneered by E. O. Wilson and Robert MacArthur. These studies led to the development of the discipline of landscape ecology.
There is no known specific preventive measure for type 1 diabetes. However, islet autoimmunity and multiple antibodies can be a strong predictor of the onset of type 1 diabetes. Type 2 diabetes—which accounts for 85–90% of all cases worldwide—can often be prevented or delayed by maintaining a normal body weight, engaging in physical activity, and eating a healthy diet. Higher levels of physical activity (more than 90 minutes per day) reduce the risk of diabetes by 28%. Dietary changes known to be effective in helping to prevent diabetes include maintaining a diet rich in whole grains and fiber, and choosing good fats, such as the polyunsaturated fats found in nuts, vegetable oils, and fish. Limiting sugary beverages and eating less red meat and other sources of saturated fat can also help prevent diabetes. Tobacco smoking is also associated with an increased risk of diabetes and its complications, so smoking cessation can be an important preventive measure as well. The relationship between type 2 diabetes and the main modifiable risk factors (excess weight, unhealthy diet, physical inactivity and tobacco use) is similar in all regions of the world. There is growing evidence that the underlying determinants of diabetes are a reflection of the major forces driving social, economic and cultural change: globalization, urbanization, population aging, and the general health policy environment.
== People == Maxim (given name) Maxim (surname) Maxim (musician) Maxim., taxonomic author abbreviation of Karl Maximovich (1827–1891), Russian botanist Maksim, Metropolitan of all Rus, Metropolitan of Kiev (1283–1305) Maksim, Bulgarian Patriarch (1914–2012), Patriarch of the Bulgarian Orthodox Church Maksim, Serbian Patriarch (d. 1680), Patriarch of the Serbian Orthodox Church (1655-1674) Maksim Branković (d. 1516), Serbian Orthodox Metropolitan of Belgrade and Syrmia
=== Further reading === The Eighth Day of Creation: Makers of the Revolution in Biology. Touchstone Books, ISBN 0-671-22540-5. 2nd edition: Cold Spring Harbor Laboratory Press, 1996 paperback: ISBN 0-87969-478-5. Micklas, David. 2003. DNA Science: A First Course. Cold Spring Harbor Press: ISBN 978-0-87969-636-8. Rasmussen, Nicolas, Gene Jockeys: Life Science and the rise of Biotech Enterprise, Johns Hopkins University Press, (Baltimore), 2014. ISBN 978-1-42141-340-2. Rosenfeld, Israel. 2010. DNA: A Graphic Guide to the Molecule that Shook the World. Columbia University Press: ISBN 978-0-231-14271-7. Schultz, Mark and Zander Cannon. 2009. The Stuff of Life: A Graphic Guide to Genetics and DNA. Hill and Wang: ISBN 0-8090-8947-5. Watson, James. 2004. DNA: The Secret of Life. Random House: ISBN 978-0-09-945184-6.
Sources: en.wikipedia.org
== Veterinary use == Lidocaine is commonly used in veterinary medicine in both companion and production animals around the world and is listed as an essential veterinary medicine by the World Veterinary Association and also the World Small Animal Veterinary Association.[1] In veterinary medicine, it is commonly used as a local anaesthetic both as an injectable or topical product. It provides excellent local anaesthesia when given by local infiltration into a tissue or via specific nerve blocks. These are commonly applied to nerves of the head, limbs, thorax, and spine. It can also be used to treat ventricular arrhythmias when given intravenously. In most veterinary species, when given via injection, it has a rapid onset of action (2-10 minutes) with a duration of action of 30-60 minutes. In veterinary species, its metabolism is much the same as humans with rapid metabolism in the liver to the major metabolites MEGX (monoethylglycine xylidide) and GX (glycine xylidide) that retain partial activity against sodium channels. These compounds are further metabolized to monoethylglycine and xylidide, respectively. Toxicity in animals is similar to that seen in humans with both toxicity to the central nervous system (CNS) and cardiovascular system observed. General the CNS signs are seen first with agitation and muscle twitching seen before the cardiovascular signs of hypotension, myocardial depression, and arrhythmias. Further CNS depression will result from higher doses with seizures and convulsions and eventually apnea and death.
Also in attendance was Nikita Khrushchev of the Soviet Union. July 27: Austria becomes an independent country after the end of the Allied occupation. The last allied troops leave the country in October. August 15: The First Sudanese Civil War begins between the north and the south. November 1: MAAG Vietnam is organized, often regarded as the starting point of the Vietnam War.
Cloning of the YAP1 gene facilitated the identification of a modular protein domain, known as the WW domain. Two splice isoforms of the YAP1 gene product were initially identified, named YAP1-1 and YAP1-2, which differed by the presence of an extra 38 amino acids that encoded the WW domain. Apart from the WW domain, the modular structure of YAP1 contains a proline-rich region at the very amino terminus, which is followed by a TID (TEAD transcription factor interacting domain). Next, following a single WW domain, which is present in the YAP1-1 isoform, and two WW domains, which are present in the YAP1-2 isoform, there is the SH3-BM (Src Homology 3 binding motif). Following the SH3-BM is a TAD (transactivation domain) and a PDZ domain-binding motif (PDZ-BM) (Figure 1).
Adolescent medicine Adult congenital heart disease Advanced heart failure and transplant cardiology Cardiovascular disease, dealing with disorders of the heart and blood vessels* Clinical cardiac electrophysiology Critical care medicine, is dealing with life-threatening conditions requiring intensive monitoring and treatment. Endocrinology, diabetes & metabolism, dealing with disorders of the endocrine system and its specific secretions called hormones Gastroenterology, concerned with the field of digestive diseases Geriatric medicine Hematology, concerned with blood, the blood-forming organs and its disorders. Hospice & palliative medicine Infectious disease, concerned with disease caused by a biological agent such as by a virus, bacterium or parasite Interventional cardiology Medical oncology, dealing with the chemotherapeutic (chemical) and/or immunotherapeutic (immunological) treatment of cancer Nephrology, dealing with the study of the function and diseases of the kidney Neurocritical care Pulmonary disease, dealing with diseases of the lungs and the respiratory tract Rheumatology, devoted to the diagnosis and therapy of rheumatic diseases Sleep medicine Sports medicine Transplant hepatology
NanoSIMS was used to study and prove for the first time the nitrogen fixing abilities of bacteria and archaea from the deep ocean by supplying 15N nitrogen contain compounds to sediment samples. NanoSIMS can also be used to estimate growth rate of organisms, as the amount of carbon or other substrate accumulated inside the cell allows for estimation of how much biomass is being generated.
Sources: en.wikipedia.org
Simple drying usually removes water by evaporation from a liquid or solid, often with heat. Lyophilization first freezes the material and then removes ice by sublimation under vacuum. This avoids prolonged exposure to liquid water and high temperatures.
Reduced pressure lowers the boiling point of water and allows ice to sublime at temperatures below freezing. It also helps remove water vapor from the product toward the condenser. The exact pressure is chosen to stay below the triple point of water.
No. Materials with low solids content or high volatile solvents may form weak or collapsed cakes. Some proteins and cells require stabilizers to survive freezing and drying stresses. Feasibility depends on formulation and process design.
Most lyophilized products are stored in sealed containers at controlled temperature and humidity. Some require refrigeration, while others are stable at room temperature. Protection from light and moisture is often necessary.