The short version of sublimation fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
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.
The process relies on the phase diagram of water, where the triple point marks the conditions at which ice, liquid water, and vapor coexist. By maintaining pressure below this point, typically around 0.01 to 0.1 millibar, sublimation becomes the dominant mechanism. Formulations often include excipients such as sugars or polymers that act as lyoprotectants and bulking agents. These additives help preserve the structure of the active ingredient and prevent collapse during drying. The choice of excipient and freezing rate influences the final cake morphology and stability.
Industries use lyophilization for pharmaceuticals, biological products, and food preservation. In the pharmaceutical sector, it extends the shelf life of injectable drugs, vaccines, and proteins that are unstable in aqueous solution. Food manufacturers apply freeze-drying to coffee, fruits, and ready meals to retain flavor and texture. The process is energy-intensive and requires specialized equipment, which limits its use to high-value products. Ongoing research examines how formulation and process parameters affect the quality of the final dried product.
| Property | Value | Notes |
|---|---|---|
| Process name | Lyophilization or freeze-drying | Both terms appear in technical standards and literature. |
| Phase transition | Sublimation | Solid ice becomes vapor without a liquid step. |
| Typical chamber pressure | 0.05-0.5 mbar | Range depends on product temperature and equipment. |
| Typical product temperature | -40 °C to -10 °C | Measured during primary drying; formulation sets limits. |
| Water content after drying | 0.5-3% w/w | Target varies by material and stability needs. |
Freeze-drying is distinct from simple evaporation and from spray drying. Evaporation removes water at temperatures above freezing, while spray drying rapidly dries droplets in a heated gas stream. Lyophilization avoids high temperatures, which can be useful for heat-sensitive materials such as proteins, vaccines, and some foods. The porous cake produced by sublimation dissolves or rehydrates more quickly than a dense dried mass. Not all materials tolerate freezing or the pH shifts that can occur as solutes concentrate during ice formation.
Lyophilization removes water from a frozen material by sublimation under reduced pressure. The process begins with freezing, which converts liquid water into ice and fixes the structure of the sample. After freezing, primary drying lowers pressure so ice changes directly to vapor without passing through a liquid phase. Secondary drying then removes bound water that remains after ice sublimation. The result is a dry, porous solid that often retains its original shape.
The low pressure used during drying allows water vapor to move from the ice surface to a cold condenser. Energy supplied as heat drives sublimation but must stay below the collapse temperature of the frozen matrix. If the product becomes too warm, the frozen structure may soften or melt, reducing pore formation and slowing drying. Formulations often include bulking agents, stabilizers, or buffers to support a rigid cake. The final moisture content depends on formulation, freezing rate, and the length of secondary drying.
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.
It efficiently sterilizes the infected root surfaces and periodontal pocket microflora Curettes the adjacent pocket epithelium Removes the smear layer Enhances calculus elimination It has been suggested that laser treatment results in minimal or no post-operative swelling, bleeding, scar tissue formation or pain. Regarding wound healing animal studies have shown better response in rat skin after Nd:YAG laser application than following scalpel incisions but this is only valid when energy and frequency parameters were low and higher levels of energy lead to scar formation and delayed wound healing. The clinical use of a laser for gingivectomy involves repeated lasing and wiping away tissue remnants with moist gauze and this results in a bloodless operating field allowing better visibility and greater ease for the operator. Apart from ablating and coagulating the laser also sterilizes the tissues and eliminates the need for a post-surgical dressing. One study found that in patients with drug induced gingival overgrowth recurrence was minimal or eliminated when comparing laser gingivectomy to scalpel gingivectomy.
==== Extrusion-based printing ==== Although there are different approaches to extrusion based printing, these approaches follow the same basic procedures. The platform on which food is printed consists of a standard 3-axis stage with a computer controlled extrusion head. This extrusion head pushes food materials through a nozzle typically by way of compressed air or squeezing. The nozzles can vary with respect to what type of food is being extruded or the desired printing speed (typically the smaller the nozzle the longer the food printing will take). As the food is printed, the extrusion head moves along the 3-axis stage printing the desired food. Some printed food requires additional processing such as baking or frying before consumption. Extrusion based food printers can be purchased for household use, are typically compact in size, and have a low maintenance cost. Comparatively, extrusion based printing provides the user with more material choices. However, these food materials are usually soft, and as a result, makes printing complex food structures difficult. In addition, long fabrication times and deformations due to temperature fluctuations with additional baking or frying require further research and development to overcome.
== Structure == Free fatty acid receptor 3 is a member of the G protein-coupled receptor (GPCR) superfamily, characterized by its seven transmembrane alpha-helices. FFAR3 shares significant sequence similarity with FFAR2 but exhibits distinct structural features that influence its ligand specificity and signaling. The receptor's orthosteric binding pocket is formed by transmembrane helices 3, 4, and 5, with key conserved residues such as Arg-185 (5.39), Arg-255 (7.35), His-140 (4.56), and His-242 (6.55) contributing to the binding and recognition of short-chain fatty acids (SCFAs) like acetate, propionate, and butyrate. Notably, FFAR3's binding cavity is more hydrophilic compared to its close relative FFAR2, which affects its ligand interactions. The second extracellular loop is important in modulating ligand selectivity and receptor activation. Additionally, the presence of a His-45 (2.40) is predicted to coordinate allosteric modulators. The human FFAR3 and FFAR2 proteins consist of 346 and 330 amino acids, respectively, and share about a 40% amino acid sequence homology. The two FFARs have been found to form a heteromer complex (i.e., FFAR3 and FFAR2 bind to each other and are activated together by a SC-FA). When stimulated by a SC-FA, the cells expressing both FFAR3 and FFAR2 may form this heterodimer and thereby activate cell signaling pathways and mount responses that differ from those of cells expressing only one of these FFARs.
Cellular thermal shift assay (CETSA) and proteome integral solubility alteration (PISA)-based proteomics are widely used in drug discovery as label-free, mass spectrometry–compatible methods for quantifying cellular target engagement (confirming that a drug binds its intended target), deconvoluting drug targets (identifying the protein target of compounds with unknown targets), and profiling off-target interactions at the proteome scale. CETSA measures drug-induced changes in protein thermal stability in intact cells or tissues and, when combined with proteomics, enables the unbiased identification and ranking of on- and off-targets, as well as supporting phenotypic hit mechanism-of-action studies. PISA extends thermal-shift principles by integrating protein solubility changes across a temperature gradient, substantially increasing throughput and enabling multiplexed analysis of multiple compounds, concentrations, or time points. This approach facilitates high-content target deconvolution and comparative mechanism-of-action profiling, including applications in low-input or automated workflows.
Sources: en.wikipedia.org
Aside from its association with trees, A. roeperi shares its most significant ecological interactions with the granulate ambrosia beetle Xylosandrus crassiusculus. As in other ambrosia beetles, the fungus benefits from the opportunity for dispersal via the insect's mycangium, which in X. crassiusculus consists of a spacious mesonotal pouch. According to the current understanding of this symbiosis, when beetles emerge from pupae, their mycangia are inoculated with ambrosial fungi, and special gland cells flanking the mycangium begin to secrete compounds that promote their growth over that of assorted commensals. When the beetles colonize a new tree, the fungus growing in the cuticular pouch is introduced to the walls of the new gallery, glandular activity stops, and the mycangium ceases to act as a selective organ. The larvae and adults feed exclusively upon the conidia produced along the walls of the gallery, through which the beetles meet all of their nutritional requirements. (This feature differentiates ambrosia beetles from bark beetles, which typically feed on the phloem and, though they may eat and/or disperse some fungi, can generally survive on wood alone.) Structures possibly comprising lipid bodies can be seen within the cytoplasm of A. roeperi spores and conidiogenous cells, which may represent a means of storage for energy-rich compounds that it then imparts to the feeding beetles. Though trees and insects are perhaps the most pivotal points of Ambrosiella ecology, the galleries in which A.
=== Mechanism of action === Codeine is an opiate and an agonist of the μ-opioid receptor (MOR). It acts on the central nervous system to have an analgesic effect. It is metabolised in the liver to produce morphine which is ten times more potent against the MOR. Opioid receptors are G protein-coupled receptors that positively and negatively regulate synaptic transmission through downstream signalling. Binding of codeine or morphine to the μ-opioid receptor results in hyperpolarization of the neuron leading to the inhibition of the release of nociceptive neurotransmitters, causing an analgesic effect and increased pain tolerance due to reduced neuronal excitability.
== Pharmacology == The drug showed antidepressant-like and anxiolytic-like effects as well as locomotor-stimulating effects in animal models. It had reduced induction of seizures and locomotor hyperactivity compared to other δ-opioid receptor agonists. The doses required for stimulant-like activity were 3- to 10-fold greater than the doses that produced antidepressant- and anxiolytic-like effects. The drug appears to have a very low misuse potential based on animal studies. In addition to its δ-opioid receptor agonist activity, AZD-2327 has been reported to act as a cytochrome P450 CYP3A4 inhibitor. It has been found to inhibit the release of norepinephrine caused by anxiety and was able to do so as much as the benzodiazepine diazepam. However, AZD-2327 could be advantageous to benzodiazepines because these drugs often cause rapid tolerance and dependence. In contrast to benzodiazepines, AZD-2327 may have less or no potential for tolerance in terms of its anxiolytic-like effects.
2021 meta-analyses of trials over periods of 1 to 28 months found limited evidence to indicate that lifestyle modifications and nutritional supplementation affect mortality, liver cirrhosis, liver decompensation, liver transplantation, and hepatocellular carcinoma in people with non-alcohol-related fatty liver disease; authors said that it was unlikely that differences in clinical outcomes would become apparent in trials with less than 5 years to 10 years of follow‐up, and that sample sizes needed to be much larger than had been used.
Sarcoidosis Granulomatous lung diseases Tuberculosis Fungal infections (e.g., histoplasmosis) Granulomatosis with polyangiitis Idiopathic pulmonary fibrosis Hypersensitivity pneumonitis Asthma Diagnosis of berylliosis is based on history of beryllium exposures, documented beryllium sensitivity, and granulomatous inflammation on lung biopsy. Given the invasive nature of a lung biopsy, diagnosis can also be based on clinical history consistent with berylliosis, abnormal chest x-ray or CT scan findings, and abnormalities in pulmonary function tests. The radiologic and pathologic features of berylliosis are very similar to sarcoidosis. Due to the strong clinical and histopathological resemblance of sarcoidosis and berylliosis, patients are sometimes misdiagnosed with sarcoidosis until the history of exposure to beryllium is elicited and beryllium hypersensitivity demonstrated with specific testing. Some studies suggest that up to 6% of all cases of sarcoidosis are actually berylliosis. The beryllium lymphocyte proliferation test (BeLPT) is the standard way of determining sensitivity to beryllium. The test is performed by acquiring either peripheral blood or fluid from a bronchial alveolar lavage, and lymphocytes are cultured with beryllium sulfate. Cells are then counted and those with elevated number of cells are considered abnormal. Those exposed persons with two abnormal BeLPT tested with peripheral blood, or one abnormal and one borderline result, are considered beryllium sensitized.
Sources: en.wikipedia.org
== Notable architecture == The county courthouse of Lebanon is notable for its single-piece vertical Ionic order limestone columns. They were at one time believed to be the largest single-piece limestone columns in the world.
One study of an elderly Japanese population found correlations between the MTHFR 677CT mutation, an Apo E polymorphism, and certain types of senile dementia. Other research has found that individuals with folate-related mutations can still have a functional deficiency even when blood levels of folate are within the normal range, and recommended supplementation of methyltetrahydrofolate to potentially prevent and treat dementia (along with depression). A 2011 study from China also found that the C677T SNP was associated with Alzheimer's disease in Asian populations (though not in Caucasians). C677T polymorphism is associated with risk of myocardial infarction in African, North American, and elderly populations. The CDC provides a web page with information on the "MTHFR Gene, Folic Acid, and Preventing Neural Tube Defects". National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention. 27 May 2025. Retrieved 6 Jun 2025.
Another key to finding the correct structure of DNA was the so-called Chargaff ratios, experimentally determined ratios of the nucleotide subunits of DNA: the amount of guanine is equal to cytosine and the amount of adenine is equal to thymine. A visit by Erwin Chargaff to England, in 1952, reinforced the salience of this important fact for Watson and Crick. The significance of these ratios for the structure of DNA were not recognised until Watson, persisting in building structural models, realised that A:T and C:G pairs are structurally similar. In particular, the length of each base pair is the same. Chargaff had also pointed out to Watson that, in the aqueous, saline environment of the cell, the predominant tautomers of the pyrimidine (C and T) bases would be the amine and keto configurations of cytosine and thymine, rather than the imino and enol forms that Crick and Watson had assumed. They consulted Jerry Donohue who confirmed the most likely structures of the nucleotide bases. The base pairs are held together by hydrogen bonds, the same non-covalent interaction that stabilise the protein α-helix. The correct structures were essential for the positioning of the hydrogen bonds. These insights led Watson to deduce the true biological relationships of the A:T and C:G pairs.
The General bails out but is immediately attacked by the escaped Worm Xenome, which comes out of a crevice and consumes him once again. The Mainframe states its intention to make the Xenome facility its home as it calls for backup, and Gunman reinforcements arrive shortly after to contain the Xenome infestation and capture any remaining rogue Gunmen.
Sources: en.wikipedia.org
Conventional drying uses heat to evaporate liquid water, often at temperatures that can degrade sensitive materials. Lyophilization freezes the material first and then removes water by sublimation under vacuum. This avoids prolonged exposure to liquid water and high heat.
Lowering pressure reduces the boiling point of water and allows ice to sublimate at temperatures below freezing. Vacuum also limits convective heat transfer, so heat is usually supplied by shelves or radiation. The pressure must stay below the vapor pressure of ice at the product temperature.
The cycle typically includes freezing, primary drying, and secondary drying. Freezing solidifies water and sets the pore structure; primary drying removes bulk ice; secondary drying removes bound water. Some cycles add annealing or pre-freezing steps.
Conventional drying uses heat to evaporate water from a material, while lyophilization freezes the material and removes water by sublimation under vacuum. This avoids the liquid phase and reduces thermal damage to sensitive substances. The result is a porous cake that reconstitutes quickly.