If you have been reading about Sublimation and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-03-31. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Lyophilization, also called freeze-drying, removes water from a frozen material by sublimation under reduced pressure. The process begins with freezing, which converts free water into ice and may also produce a glassy phase. Primary drying then lowers chamber pressure so ice sublimes directly to vapor without passing through a liquid stage. Secondary drying raises the temperature modestly to remove bound water. The result is a porous, dry solid that usually reconstitutes quickly. Each stage influences pore structure, residual moisture, and stability.
Storage stability depends on water content, oxygen exposure, and temperature. Lyophilized solids are hygroscopic and can absorb water if exposed to humid air. Vials are usually sealed under vacuum or inert gas with rubber stoppers and aluminum crimps. Storage temperatures range from room temperature to refrigerated or frozen conditions depending on the material. Stability studies track potency, moisture, and physical form over time. Accelerated conditions can reveal sensitivity but may not predict long-term behavior.
Analytical methods for lyophilized materials include X-ray diffraction for crystallinity, differential scanning calorimetry for thermal transitions, and scanning electron microscopy for pore morphology. Moisture sorption analysis shows how the cake responds to humidity. These methods help distinguish amorphous from crystalline states and detect phase changes. Open questions remain about how pore structure changes during long-term storage and how best to predict collapse under varied conditions. Comparisons across studies are complicated by differences in formulation, cycle, and storage history.
| 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. |
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.
Stability of a lyophilized solid depends on water content, temperature, and the physical state of the formulation. Amorphous products may slowly absorb moisture and drop below their glass transition temperature, causing collapse or crystallization. Some proteins and peptides can aggregate even in a dry state, especially when exposed to heat or moisture. Accelerated stability studies at elevated temperature and humidity help estimate shelf life, but real-time data remain the basis for expiration dating.
After drying, a lyophilized product is usually sealed under vacuum or an inert gas to limit moisture and oxygen exposure. The container closure system matters because stoppers and seals can allow moisture ingress over time. Storage conditions are selected from stability studies that track potency, cake appearance, and reconstitution behavior. Many freeze-dried materials are kept at controlled room temperature, while some require refrigeration or protection from light.
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.
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.
After lyophilization, a product's quality depends on residual moisture, cake appearance, and reconstitution time. Residual moisture is often measured by Karl Fischer titration or thermogravimetric analysis. A low moisture content can slow chemical degradation, but overly dry cakes may be brittle or slow to dissolve. Stability studies track these attributes over months under defined temperature and humidity conditions. Batch records link these measurements to specific process runs and help identify trends before a product fails specification.
Storage conditions for dried products usually aim to exclude moisture and oxygen. Vials are sealed under vacuum or with an inert gas, and stoppers must maintain a barrier during transport. Temperature recommendations vary; some materials remain stable at room temperature, while others need refrigeration or frozen storage. Humidity control is critical because dried cakes can absorb water rapidly once a container is opened. Desiccant packs and moisture-barrier bags add further protection during shipping.
The brand name featured on the label is usually the same as the distillery name (for example, the Talisker distillery labels its whiskies with the Talisker name). Indeed, the SWR prohibits bottlers from using a distillery name when the whisky was not made there. A bottler's name may also be listed, sometimes independent of the distillery. In addition to requiring that Scotch whisky be distilled in Scotland, the SWR requires that it also be bottled and labelled in Scotland. Labels may also indicate the region of the distillery (for example, Islay or Speyside). Alcoholic strength is expressed on the label by Alcohol By Volume (ABV) or sometimes simply "Vol". Typically, bottled whisky is between 40% and 46% ABV. Whisky is considerably stronger when first emerging from the cask—normally 60–63% ABV. Water is then added to create the desired bottling strength. If the whisky is not diluted before bottling, it can be labelled as cask strength. A whisky's age may be listed on the bottle providing a guarantee of the youngest whisky used. An age statement on the bottle, in the form of a number, must reflect the age of the youngest whisky used to produce that product. A whisky with an age statement is known as guaranteed age whisky. Scotch whisky without an age statement may, by law, be as young as three years old. In the early 21st century, such "No age statement" whiskies have become more common, as distilleries respond to the depletion of aged stocks caused by improved sales. A label may carry a distillation date or a bottling date.
The targeting of hospitals, as well as religious sites, constitutes a war crime. Lebanese health minister Firass Abiad said that 163 rescuers and health workers were killed and 273 others were injured in Lebanon since the start of Israel–Hezbollah conflict. Human Rights Watch stated that Israel's "repeated" attacks on medical workers and healthcare facilities were apparent war crimes. The IDF shelled Meiss Ej Jabal Hospital, injuring a doctor on 10 November 2023. The missiles did not explode but caused damage to the emergency department and several cars. Lebanon's Ministry of Public Health condemned the attack, saying that "Israeli authorities were fully responsible for this unjustifiable act, which would have led to catastrophic results", and called for an investigation. Days before, four people were reportedly injured after an Israeli bombing that hit two ambulances. The Lebanese National News Agency said that an Israeli drone strike hit two ambulances belonging to the Risala Scout Association, which is affiliated with the Amal Movement. On 26 December 2023, an anti-tank missile shot by Hezbollah fighters from Lebanon damaged a shed in a church compound in Iqrit, but not the church itself, wounding an elderly civilian. As IDF troops and medical services were working to evacuate him, they were hit by further missiles, which resulted in nine soldiers being wounded, one of them seriously. On 11 January 2024, the IDF conducted strikes in the town of Hanine and targeted an emergency center affiliated with the Hezbollah-linked Islamic Health Authority.
“Chemoinformatics and Molecular Simulation”; “Chemistry of Supramolecular Nano- and Biosystems”; “Methods of Analytical Chemistry”; “Physical-Chemical Methods in Chemistry”; “Petrochemistry and Catalysis”. Total number of students taking Bachelor, Specialist and master's degree programs is 472 (as of January, 2016).Departments of the Institute of Chemistry educate postgraduates in the following majors: 02.00.01 – Inorganic Chemistry; 02.00.02 – Analytical Chemistry; 02.00.03 – Organic Chemistry; 02.00.04 – Physical Chemistry; 02.00.08 – Chemistry of Organoelement Compounds. There are two dissertation councils functioning in the Institute of Chemistry for thesis defence in chemical sciences: Д 212.081.03 under the Federal State Autonomous Institution of Higher Education “Kazan (Volga Region) Federal University”; majors allowed for defence: 02.00.01 – Inorganic Chemistry; 02.00.08 – Chemistry of Organoelement Compounds; Chairman of the Council is Professor Vladimir I. Galkin, Doctor of Chemistry;
The NAD⁺-II riboswitch (also called the pnuC RNA motif) is a riboswitch found in bacteria that regulates gene expression in response to levels of nicotinamide adenine dinucleotide (NAD⁺) and related metabolites, particularly nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR). A shorter variant, the mini-NAD⁺-II riboswitch, was described in 2025 and is more phylogenetically widespread than the original class. NAD⁺ is a ubiquitous enzyme cofactor that functions as a carrier of hydride ions in metabolic oxidation-reduction reactions. It also serves as a source of activated adenosine monophosphate (AMP) for adenylation reactions and as a precursor of ADP-ribose. Because of NAD⁺'s essential role in cellular metabolism, bacteria must carefully regulate genes involved in both the de novo biosynthesis and salvage (recycling) of NAD⁺ and its many derivatives. Two classes of NAD riboswitches have been identified: NAD-I and NAD⁺-II.
Sources: en.wikipedia.org
Cholera toxins: encoded by CTX phages, virulent Vibrio cholerae strains require lysogenic conversion by CTX phage infection Several botulinum toxins (BoNTs): Type C and D BoNTS have been shown to be encoded by clostridial phages and are produced by Clostridium botulinum strains harboring these phage genes Shiga toxins: encoded by lambdoid phages, mainly produced by lysogenic shiga-toxin producing strains of E. coli (STEC) Diphtheria toxins: encoded by corynephage ß, produced by lysogenic Corynebacterium diphtheriae strains infected with corynephage ß Several staphylococci toxins (staphylokinase (SAK), staphylococcal enterotoxin A (SEA), exfoliative toxin (ETA), Panton–Valentine leucocidin (PVL), and other enterotoxins): toxins that are phage-encoded and produced by lysogenic converted strains of the staphylococci group.
46. Sheng Li Xue Bao. 2024 Dec 25;76(6):1032-1042. [Research progress on anti-aging effects of β-nicotinamide mononucleotide (NMN)]. [Article in Chinese] Han M(1), Hua JL(1). Author information: (1)College of Veterinary Medicine, Shaanxi Centre of Stem Cells Engineering & Technology, Northwest A&F University, Yangling 712100, China. β-Nicotinamide mononucleotide (NMN), as the precursor of nicotinamide adenine dinucleotide (NAD), plays an important role in enhancing NAD levels. Intake of NMN can alter the composition and vitality of gut microbiota, restore mitochondrial function, inhibit inflammatory pathways, improve metabolism, counteract oxidative stress, and alleviate inflammation. NMN significantly improves recovery from aging-related diseases, such as diminished heart function, reduced fertility, memory decline, and diabetes. NMN demonstrates both efficacy and safety in anti-aging. The use of NMN in China has gradually gained acceptance, highlighting the importance of exploring the mechanism of NMN in anti-aging effects and improving the biosynthesis of NMN. In addition, NMN in combination with stem cells hold promise in the treatment of aging-related degenerative diseases and promote overall human and animal health.
Patients present with protrusion of the brain tissue and degeneration of the retina; an individual who has family members with the disorder is at an increased risk of developing it themselves since there is a hereditary link.
== Distribution == The labeled [18F]FDG compound has a relatively short shelf life which is determined largely by the physical decay of fluorine-18 with a half-life of 109.8 minutes, or slightly less than two hours. Still, this half-life is sufficiently long to allow shipping the compound to remote PET scanning facilities, in contrast to other medical radioisotopes like carbon-11 with a half-life of ~20 minutes. Due to transport regulations for radioactive compounds, delivery is normally done by specially licensed road transport, but means of transport may also include dedicated small commercial jet services. Transport by air allows expanding the distribution area around a [18F]FDG production site to deliver the compound to PET scanning centres within a 1–3-hour flight time. Recently, on-site cyclotrons with integral shielding and portable chemistry stations for making [18F]FDG have accompanied PET scanners to remote hospitals. This technology holds some promise in the future, for replacing some of the scramble to transport [18F]FDG from site of manufacture to site of use.
The study found an overall 1.4 fold increase in risk of cardiovascular ischemic events relative to the control arms. The results were heterogenous, with clear evidence of increased risk relative to placebo but not relative to other diabetes treatments and higher risk associated with combinations of rosiglitazone with insulin or metformin. Based on the 1.4 fold increased risk relative to control groups, FDA scientist David Graham presented an analysis suggesting that rosiglitazone had caused 83,000 excess heart attacks between 1999 and 2007. The advisory panel voted 20 : 3 that the evidence available indicated that rosiglitazone increased the risk of cardiovascular events and 22 : 1 that the overall risk:benefit ratio of rosiglitazone justified its continued marketing in the United States. The FDA placed restrictions on the drug, including adding a boxed warning about heart attacks, but did not withdraw it. In 2000 a study to address the concerns regarding cardiovascular safety was requested by the European Medicines Agency (EMA). GSK agreed to perform post-marketing a long-term cardiovascular morbidity/mortality study in patients on rosiglitazone in combination with a sulfonylurea or metformin: the RECORD study. The results as published in 2009 showed that rosiglitazone was non-inferior to treatment with metformin or a sulfonylurea with respect to the rate of cardiovascular events and cardiovascular death. European regulators concluded that due in part to design limitations, the results neither proved nor eliminated concerns of excess cardiovascular risk.
Sources: en.wikipedia.org
=== Structure === It is an organic compound, associated with the class of L-alpha-amino acids. These compounds have the L-configuration of the alpha carbon atom. Quisqualic acid contains, in its structure a five membered, planar, conjugated, aromatic heterocyclic system, consisting of one oxygen atom and two nitrogen atoms at position 2 and 4 of the oxadiazole ring. The 1,2,4–oxadiazole ring structure is present in many natural products of pharmacological importance. Quisqualic acid, which is extracted from the seeds of Quisqualis indica, is a strong antagonist of AMPA receptors.
If the incircle is tangent to the sides AB, BC, CD, DA at T1, T2, T3, T4 respectively, and if N1, N2, N3, N4 are the isotomic conjugates of these points with respect to the corresponding sides (that is, AT1 = BN1 and so on), then the Nagel point of the tangential quadrilateral is defined as the intersection of the lines N1N3 and N2N4. Both of these lines divide the perimeter of the quadrilateral into two equal parts. More importantly, the Nagel point N, the "area centroid" G, and the incenter I are collinear in this order, and NG = 2GI. This line is called the Nagel line of a tangential quadrilateral. In a tangential quadrilateral ABCD with incenter I and where the diagonals intersect at P, let HX, HY, HZ, HW be the orthocenters of triangles AIB, BIC, CID, DIA. Then the points P, HX, HY, HZ, HW are collinear.
A serial killer is typically a person who kills three or more people, with the murders taking place over more than a month and including a significant period of time between them. The Federal Bureau of Investigation (FBI) defines serial murder as "a series of two or more murders, committed as separate events, usually, but not always, by one offender acting alone". The United States has by far the largest number of documented serial killers in the world. According to Radford University's Serial Killer Information Center, it has more documented serial killers than the next ten highest countries on the list combined.
== Side-effects == AMPT administration in healthy subjects has shown to cause increased sleepiness, decreased calmness, increased tension and anger, and a trend for increased depression. Sedation was also reported as a side effect of AMPT ingestion. However, sedation was not seen in AMPT doses of less than 2g per day. Patients have reported insomnia as a withdrawal symptom post AMPT exposure. When L-dopa is administered following AMPT administration, the effects of AMPT are reversed. These findings suggest that AMPT's effect on alertness and anxiety is catecholamine-specific and further supports that catecholamines are involved in the regulation of normal states of arousal and pathological anxiety symptoms. Patients have reported hand, leg, and trunk tremors as well as tightening of the jaw post AMPT drug therapy. These Parkinson like side effects are supported by the lack of dopamine in the brain as in Parkinson’s patients. Tourette syndrome patients treated with AMPT developed akinesia, akathisia, oculogyric crisis, and crystalluria (crystals in the urine). Prolonged administration can have an impact upon the circadian rhythm.
Valve struggled to find a publisher, as many believed Half-Life was too ambitious for a first-time developer. Sierra On-Line signed Valve for a one-game deal as it was interested in making a 3D action game, especially one based on the Quake engine. Sierra gave Valve an advance of around $1 million in exchange for 30% of the revenue and 100% of the intellectual property; the rest of development was funded by Newell and Harrington. Valve first showed Half-Life in early 1997; it was a success at E3 that year, where Valve demonstrated the animation and artificial intelligence. Novel features of the artificial intelligence included fear and pack behavior. Valve aimed for a November 1997 release to compete with Quake II. By September 1997, the team found that, while they had built some innovative aspects in weapons, enemies, and level design, the game was not fun and there was little design cohesion. Playtesting produced "lukewarm" responses. Sierra would not agree to extra funding, so Newell took out a loan to fund additional development to rework the game and delay its release date. Valve took a novel approach of assigning a small team to build a prototype level containing every element in the game and then spent a month iterating on the level. When the rest of the team played the level, which the designer Ken Birdwell described as "Die Hard meets Evil Dead", they agreed to use it as a baseline. The team developed three theories about what made the level fun.
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.
Karl Fischer titration is a common method, using coulometric or volumetric detection. Thermogravimetric analysis can also measure weight loss on heating. Results depend on sample handling because the dried solid can absorb moisture quickly.