The short version of collapse temperature fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-04-12. Anything still debated is marked as such rather than presented as settled.
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.
Lyophilization, also called freeze-drying, is a dehydration process in which a solvent, usually water, is frozen and then removed by sublimation under reduced pressure. The method preserves heat-sensitive materials that would degrade in conventional drying. Large-scale use grew during the mid-twentieth century for blood plasma and antibiotics, and it later expanded to vaccines, enzymes, foods, and advanced materials. The process produces a dry, porous solid that usually reconstitutes rapidly. It is distinct from simple evaporation because the solvent bypasses the liquid phase during primary removal.
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.
The process usually has three stages: freezing, primary drying, and secondary drying. Freezing sets the ice crystal structure and can determine pore size in the final cake. Primary drying removes free ice by sublimation at low pressure and low shelf temperature. Secondary drying removes bound water by raising the shelf temperature, although some water may remain as part of the solid. Cycle parameters depend on formulation, fill volume, vial type, and equipment performance.
The physical chemistry of freezing influences whether a formulation forms an amorphous glass or a crystalline solid. Amorphous systems can collapse if product temperature rises above the glass transition temperature of the freeze concentrate. Crystalline systems may show eutectic melting, where ice and solute melt together at a fixed temperature. Formulators add bulking agents, lyoprotectants, and buffers to preserve structure and biological activity. The optimum cycle keeps product temperature below critical thresholds during primary drying while allowing efficient sublimation.
Lyophilization is a dehydration process that removes water from a frozen material by sublimation under low pressure. The material is first frozen so that water becomes ice; then the surrounding pressure is lowered below the vapor pressure of ice. Heat is applied gently so ice changes directly to vapor without passing through a bulk liquid phase. The vapor is collected on a cold condenser, leaving a dry porous matrix. This process differs from simple evaporation because the material remains frozen during the main drying stage.
| Property | Value | Notes |
|---|---|---|
| Common names | Lyophilization; freeze-drying | Terms used interchangeably. |
| Phase change | Sublimation | Ice converts directly to vapor under vacuum. |
| Typical chamber pressure | 0.01–1 mbar | Below the triple point of water. |
| Primary drying product temperature | −40 to −10 °C | Kept below collapse or glass transition temperature. |
| Water content after drying | 0.5–3% w/w | Varies with formulation and cycle. |
A freeze-dryer consists of a vacuum chamber, temperature-controlled shelves, a condenser, and a vacuum pump. Vials, ampoules, or bulk trays hold the product during the cycle. The condenser traps water vapor as ice at a temperature lower than the product. Cycle development balances shelf temperature, chamber pressure, and time. Scale-up can be difficult because heat and mass transfer change with equipment size, so process analytical tools and conservative validation are often used.
Lyophilization is a dehydration technique in which a product is frozen and the solvent is removed under reduced pressure. The low pressure allows ice to sublimate directly into vapor without passing through a bulk liquid phase. This differs from conventional drying, where heat drives evaporation and can damage heat-sensitive structures. The process is used for biological materials, pharmaceutical formulations, and some foods. Its main advantage is preservation of porous structure and rapid reconstitution.
The physics of freeze-drying couples heat transfer, mass transfer, and phase change. Heat supplied through the shelf must reach the sublimation front without melting the ice or degrading the product. Water vapor then travels through the already dried layer and leaves the chamber, where low pressure and cold traps keep it from returning. The dried layer acts as a resistance to vapor flow, so drying rate changes as the front recedes. Open questions remain about how pore structure and formulation heterogeneity affect drying uniformity at larger scales.
Lyophilization removes water from a frozen material by sublimation under reduced pressure. The process begins with freezing, which converts liquid water into ice and concentrates dissolved solids. Primary drying then lowers chamber pressure so ice changes directly into vapor without passing through a liquid phase. Secondary drying raises the shelf temperature to remove bound water that remains after ice sublimation. The result is a dry, porous structure that can be reconstituted later.
A typical cycle begins with freezing, sometimes including an annealing step to control ice crystal size. Freezing conditions influence the pore network that later allows vapor escape. During primary drying, shelf temperature and chamber pressure are set so heat enters the product while its temperature stays below the collapse or eutectic point. Secondary drying then raises the shelf temperature to desorb bound water and lower residual moisture. Cycle design depends on formulation, fill volume, container type, and equipment capability.
The physics of lyophilization couples heat transfer, mass transfer, and phase behavior. Sublimation requires a vapor pressure difference between the ice front and the chamber, and the dried layer adds resistance to vapor flow. Amorphous formulations are characterized by a glass transition temperature of the maximally freeze-concentrated solute, often denoted Tg'. Crystalline bulking agents can provide structure, while amorphous excipients stabilize labile components. Open questions remain about spatial heterogeneity, edge effects, and how laboratory cycles scale to production.
Lyophilization is a drying process in which a solvent, usually water, is removed from a frozen material by sublimation under reduced pressure. The material is first solidified, then placed under vacuum so that ice transitions directly to vapor without a bulk liquid phase. This approach suits heat-sensitive substances that would degrade during conventional evaporation. Primary drying removes unbound ice, while secondary drying reduces water that remains adsorbed to the solid matrix. The result is a porous, lightweight solid that can be reconstituted later.
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.
Freezing determines ice crystal structure and pore size, which affect drying speed and product uniformity. Rapid freezing creates small crystals, while slow freezing creates larger crystals and often faster sublimation. During primary drying, chamber pressure is held below the vapor pressure of ice, and shelf temperature supplies heat for sublimation. The ice front recedes, leaving a porous matrix. Thermal limits such as collapse and eutectic temperatures set safe boundaries for formulation. These limits vary with solute composition and concentration.
Fluoxetine is a racemic mixture of (R)- and (S)-fluoxetine where both enantiomers contribute to its biological activity. Since mono-substitution in the 4-para position of the phenoxy group (figure 4) results in selective inhibition of 5-HT re-uptake, a disubstitution i.e. 2,3- or 2,4- substitution therefore results in a loss of SERT selectivity. Fluoxetine has the widest spectrum of activity since it is the least SERT selective of all the SSRIs. Fluoxetine also has a 5-HT2C antagonist activity where it blocks the 5-HT activity of 5-HT2C receptors enhancing the release of both NE and DA. A 5-HT2C antagonist do not only help out with therapeutic effects of fluoxetine but also the tolerability of the drug. The advantage of being 5-HT2C antagonist is that it has a stimulatory effect and many patients have experienced an increase in energy, concentration and focus and a decrease in fatigue from the very first dose. The stimulant activity of 5-HT2C antagonist can however, be a disadvantage for patients with agitation, insomnia and anxiety. Another feature of fluoxetine is a weak NE re-uptake inhibition which can have clinical effect in higher doses. Fluoxetine also has a long half-life which can reduce withdrawal symptoms which are characteristic for some SSRIs after abrupt discontinuation, but it also means that it takes a long time to clear the drug and its active metabolite after discontinuing fluoxetine treatment.
Ripasudil had no effect on respiratory or neurological function. Although no carcinogenicity studies were performed on the drug, developers believed it to be non-carcinogenic due to its rapid elimination and therefore lack of accumulation in tissue, as well as the lack of inflammatory response in the eye post-administration.
Historically, an association between the color of blood and rust occurs in the association of the planet Mars, with the Roman god of war, since the planet is an orange-red, which reminded the ancients of blood. Although the color of the planet is due to iron compounds in combination with oxygen in the Martian soil, it is a common misconception that the iron in hemoglobin and its oxides gives blood its red color. The color is actually due to the porphyrin moiety of hemoglobin to which the iron is bound, not the iron itself, although the ligation and redox state of the iron can influence the pi to pi* or n to pi* electronic transitions of the porphyrin and hence its optical characteristics. Artist Julian Voss-Andreae created a sculpture called Heart of Steel (Hemoglobin) in 2005, based on the protein's backbone. The sculpture was made from glass and weathering steel. The intentional rusting of the initially shiny work of art mirrors hemoglobin's fundamental chemical reaction of oxygen binding to iron. Montreal artist Nicolas Baier created Lustre (Hémoglobine), a sculpture in stainless steel that shows the structure of the hemoglobin molecule. It is displayed in the atrium of McGill University Health Centre's research centre in Montreal. The sculpture measures about 10 metres × 10 metres × 10 metres.
The choroid plexus, or plica choroidea, is a plexus of cells that arises from the tela choroidea in each of the ventricles of the brain. Regions of the choroid plexus produce and secrete most of the cerebrospinal fluid (CSF) of the central nervous system. The choroid plexus consists of modified ependymal cells surrounding a core of capillaries and loose connective tissue. Multiple cilia on the ependymal cells move to circulate the cerebrospinal fluid.
Sources: en.wikipedia.org
== Economy == Major companies based in Yavne include Ormat Industries, Aeronautics Defense Systems, Avisar and Orbotech. In 2019, Merck established an incubator in Yavne with a budget of about €20 million over three years that will invest in startups focusing on semiconductor and display crystal technologies. In 2022 Recipharm established a new facility in Yavne. MediWound manufactures NexoBrid in Yavne, a unique product for the treatment of severe burns. It allows saving affected tissue which would otherwise need to be removed, leading to less amputations of hands and feet. Many October 7, 2023 victims have benefitted from it, with the US also buying $20 million worth of NexoBrid for its strategic national stockpile. In 2012 a new green neighborhood "Neot Rabin" was inaugurated in the south of the city.
Although many mechanisms have been proposed, no definite model accounts for the mechanisms of chronic arsenic poisoning. The prevailing events of toxicity and carcinogenicity might be quite tissue-specific. The current consensus on the mode of carcinogenesis is that it acts primarily as a tumor promoter. Its co-carcinogenicity has been demonstrated in several models. However, the finding of several studies that chronically arsenic-exposed Andean populations (as most extremely exposed to UV-light) do not develop skin cancer with chronic arsenic exposure, is puzzling.
Prokaryotic ubiquitin-like protein (Pup) is a functional analog of ubiquitin which has been found in the gram-positive bacterial phylum Actinomycetota. It serves the same function (targeting proteins for degradations), although the enzymology of ubiquitylation and pupylation is different, and the two families share no homology. In contrast to the three-step reaction of ubiquitylation, pupylation requires two steps, therefore only two enzymes are involved in pupylation. In 2017, homologs of Pup were reported in five phyla of gram-negative bacteria, in seven candidate bacterial phyla and in one archaeon The sequences of the Pup homologs are very different from the sequences of Pup in gram-positive bacteria and were termed Ubiquitin bacterial (UBact), although the distinction has yet not been proven to be phylogenetically supported by a separate evolutionary origin and is without experimental evidence. The finding of the Pup/UBact-proteasome system in both gram-positive and gram-negative bacteria suggests that either the Pup/UBact-proteasome system evolved in bacteria prior to the split into gram positive and negative clades over 3000 million years ago or, that these systems were acquired by different bacterial lineages through horizontal gene transfer(s) from a third, yet unknown, organism. In support of the second possibility, two UBact loci were found in the genome of an uncultured anaerobic methanotrophic Archaeon (ANME-1;locus CBH38808.1 and locus CBH39258.1).
Sanders's campaign manager was Faiz Shakir. The campaign's national co-chairs were Ben & Jerry's co-founder Ben Cohen, Representative Ro Khanna, Our Revolution president Nina Turner, and San Juan mayor Carmen Yulín Cruz.
== Memberships == Burnham has held senior positions and leadership roles in several professional organizations, including the American Society for Microbiology, Clinical and Laboratory Standards Institute, the American Society for Microbiology, and the Academy of Clinical Laboratory Physicians and Scientists.
Sources: en.wikipedia.org
FSL have been used to create human red cell kodecytes that have been used to detect and identify blood group allo-antibodies as ABO sub-group mimics, ABO quality control systems, serologic teaching kits and a syphilis diagnostic. Kodecytes have also demonstrated that FSL-FLRO4 is a suitable reagent for labelling packed red blood cells (PRBC) at any point during routine storage and look to facilitate the development of immunoassays and transfusion models focused on addressing the mechanisms involved in transfusion-related immunomodulation (TRIM). Murine kodecytes have been experimentally used to determine in vivo cell survival, and create model transfusion reactions. Zebrafish kodecytes have been used to determine real time in vivo cell migration. Kodecytes have been used to create influenza diagnostics. Kodecytes which have been modified with FSL-GB3 were unable to be infected with the HIV virus.
That Florey was not a pathologist was not overlooked; the Scottish pathologist Robert Muir declared: "There is no pathologist named Florey." The faculty board decided to take a chance on Florey, and he was appointed on 9 December. He took up the appointment in March 1932. The Floreys moved for the fourth time in five years, this time to a Victorian manor on 1 acre (0.40 ha) of ground about 1 mile (1.6 km) from the university, which later became student accommodation with the name "Florey Lodge". The chair came with a salary of £1,000 (equivalent to £57,000 in 2025) per annum, but there was no provision for an assistant. He took Kent with him anyway, eventually securing 50 shillings a week (equivalent to £141 in 2025) for him from the Medical Research Council (MRC). Guy's Hospital in London offered Florey a chair in pathology in February 1933. This caused alarm at the university, for it had recently lost two of its senior professors through the retirement of John Beresford Leathes and the departure of Edward Mellanby to become the secretary of the MRC. The university officials did not wish to lose Florey as well, and they raised his salary to £1,200 per annum to induce him to stay. The Sheffield Medical School was small, with only about fourteen students each year. The lack of a first-rate pathologist was remedied when Beatrice Pullinger joined the staff in January 1934, and she became Florey's ally in successfully lifting the standard of research and teaching in the department. While Florey's main interest was lysozyme, he pursued other lines of research as well.
It is usually well tolerated, though overdose toxicity is possible. Occasionally side effects include headache, numbness, and sleepiness. Pyridoxine overdose can cause a peripheral sensory neuropathy characterized by poor coordination, numbness, and decreased sensation to touch, temperature, and vibration. Healthy human blood levels of pyridoxine are 2.1–21.7 ng/mL. Normal doses are safe during pregnancy and breastfeeding.
Blocking LRP5 expression using siRNA against LRP5 resulted in a significant decrease in MMP13 mRNA and protein expressions. The catabolic role of LRP5 appears to be mediated by the Wnt/beta-catenin pathway in human osteoarthritis. The polyphenol curcumin increases the mRNA expression of LRP5.
A sphinx ( SFINKS; Ancient Greek: σφίγξ, pronounced [spʰíŋks]; pl. sphinxes or sphinges ) is a mythical creature with the head of a human, the body of a lion, and the wings of an eagle. In Greek tradition, the sphinx is a treacherous and merciless being with the head of a woman, the haunches of a lion, and the wings of a bird. According to Greek myth, she challenges those who encounter her to answer a riddle, and kills and eats them when they fail to solve the riddle. This deadly version of a sphinx appears in the myth and drama of Oedipus. In Egyptian mythology, in contrast, the sphinx is typically depicted as a man (an androsphinx (Ancient Greek: ἀνδρόσφιγξ)), and is seen as a benevolent representation of strength and ferocity, usually of a pharaoh. Unlike Greek or Levantine/Mesopotamian ones, Egyptian sphinxes were not winged. Both the Greek and Egyptian sphinxes were thought of as guardians, and statues of them often flank the entrances to temples. During the Renaissance, the sphinx enjoyed a major revival in European decorative art. During this period, images of the sphinx were initially similar to the ancient Egyptian version, but when later exported to other cultures, the sphinx was often conceived of quite differently, partly due to varied translations of descriptions of the originals, and partly through the evolution of the concept as it was integrated into other cultural traditions. However, depictions of the sphinx are generally associated with grand architectural structures, such as royal tombs or religious temples.
Sources: en.wikipedia.org
Yes. Lyophilization and freeze-drying are synonyms for the same vacuum-assisted sublimation process. The term lyophilization is more common in pharmaceutical and laboratory settings, while freeze-drying is widely used in food and general contexts.
Reduced pressure lowers the boiling point of water and allows ice to sublime below its triple point. Without sufficient vacuum, melting or boiling may occur instead of sublimation, which can damage the product structure.
Heat and mass transfer limit drying once the ice front recedes. The dried layer insulates the frozen core and resists vapor flow, so increasing shelf temperature too quickly can cause collapse or meltback.
The main change is sublimation, in which ice becomes water vapor without melting into liquid water. This occurs when the chamber pressure is held below the vapor pressure of ice while mild heat is supplied. The result is a dry, porous solid that retains much of its original shape.