Everything below concerns sublimation. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-06-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Freezing is the first stage and sets the ice structure that later becomes the pore network. The formulation is cooled below its freezing point, often with a controlled ramp, and solutes concentrate as ice forms. Primary drying then lowers chamber pressure and supplies heat to sublime the ice. The product temperature must stay below its collapse or eutectic temperature to prevent structural loss. Secondary drying raises the temperature modestly to remove bound water and achieve a low residual moisture.
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.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | freeze-drying, lyophilisation, cryodesiccation | Lyophilization is common in pharmaceutical literature. |
| Typical chamber pressure during primary drying | 0.05–0.5 mbar (5–50 Pa) | Must remain below the triple point of water. |
| Typical shelf temperature during freezing | −40 to −20 °C | Lower temperatures may be used for eutectic systems. |
| Typical residual moisture after secondary drying | 0.5–3% w/w | Product-dependent; low moisture improves stability but can cause over-drying. |
| Typical analytical method for residual moisture | Karl Fischer titration or loss on drying | Thermogravimetric methods are also used. |
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.
A typical cycle begins with freezing, which fixes the material into a solid and determines ice crystal size. Primary drying then raises heat under vacuum so ice sublimes, often near or below the collapse temperature of the formulation. Secondary drying removes bound water that remains after ice is gone, usually by gently warming the product. Each stage balances heat input against pressure to avoid melting or structural damage. Temperature probes and pressure sensors guide the transition between stages.
In practice, lyophilization is slower and more energy intensive than simple drying. Cycle times can range from hours to several days depending on load, container, and formulation. Amorphous materials may require excipients that help preserve structure during freezing and drying. The method is widely used for biological materials, pharmaceuticals, and foods where heat drying would cause unacceptable change. Open questions remain about scaling cycles between laboratory and production equipment, and this gap affects technology transfer.
Looksmaxxing (; LUUKS-MAK-sing) is an online self-improvement practice from the manosphere focused on maximizing one's physical attractiveness. The term is a neologism which was coined on incel message boards in the 2010s. Previously, the phrase had limited usage on obscure internet forums of the incelosphere, but was popularized on TikTok by primarily male content creators in the 2020s. Based on white supremacy, the term has commonly been associated with the black pill ideology, which espouses that female sexual selection is primarily based on external physical qualities such as height and facial attractiveness, while qualities such as kindness and personality are ignored or even cause rejection. Looksmaxxing methods range from benign practices such as skincare routines and gym use, to more extreme interventions such as invasive cosmetic surgery and injection of anabolic steroids, human growth hormone and other peptides. Commentators generally criticize the concept as being judgemental and harmful to its practitioners ("looksmaxxers"). Communities and influencers associated with the practice are described as rating individual's appearance without concern for their overall well-being which can lead to negative mental health outcomes such as body dysmorphia and suicidal ideation. The increasing popularity of the concept has also led to concerns over its potential to promote hegemonic masculinity.
== Early political career (1959–1970) == After World War II ended and the Japanese withdrew, the British grouped the Malay states and the Straits Settlements into the Malayan Union, and granted citizenship to non-Malays. This caused major backlash from Malays and a wave of Malay nationalism swept across the country. Mahathir became politically activated by these changes, joining protests and activism against the new citizenship policies. Mahathir later argued for affirmative action for Malays at medical college. While at college, he contributed to The Straits Times under the pseudonym "C.H.E. Det" and a student journal, in which he fiercely promoted Malay rights, such as calling for the restoration of Malay as an official language. While practising as a physician in Alor Setar, Mahathir became active in UMNO. His earliest political involvement was in the Kampung Charok Kudong Umno branch, where he made his debut in politics. By the time of the first general election for the independent state of Malaya in 1959, he was the chairman of the party in Kedah. Despite his prominence in UMNO, Mahathir was not a candidate in the 1959 election, ruling himself out following a disagreement with then Prime Minister Tunku Abdul Rahman. Their relationship had been strained since Mahathir had criticised Tunku's agreement to retain British and Commonwealth forces in Malaya after independence. Tunku opposed Mahathir's plans to introduce minimum educational qualifications for UMNO candidates.
Later in the 20th century several British pathologists, Mikey Rochman, Francis Camps, Sydney Smith and Keith Simpson pioneered new forensic science methods. Alec Jeffreys pioneered the use of DNA profiling in forensic science in 1984. He realized the scope of DNA fingerprinting, which uses variations in the genetic code to identify individuals. The method has since become important in forensic science to assist police detective work, and it has also proved useful in resolving paternity and immigration disputes. DNA fingerprinting was first used as a police forensic test to identify the rapist and killer of two teenagers, Lynda Mann and Dawn Ashworth, who were both murdered in Narborough, Leicestershire, in 1983 and 1986 respectively. Colin Pitchfork was identified and convicted of murder after samples taken from him matched semen samples taken from the two dead girls.
Half Bad is a 2014 young adult fantasy novel written by English author Sally Green. It won the 2015 Waterstones Teen Book Prize and was shortlisted for the 2015 Branford Boase Award. On 3 March 2014, the book set the Guinness World Record as the 'Most Translated Book by a Debut Author, Pre-publication', having sold in 45 languages prior to its UK publication by Penguin books.
Sources: en.wikipedia.org
Voltage – Regulated by the difference in voltage across the membrane Stress – Regulated by physical pressure on the transporter (as in the cochlea of the ear) Ligand – Regulated by the binding of a ligand to either the intracellular or extracellular side of the cell Uniporters are found in mitochondria, plasma membranes and neurons.The uniporter in the mitochondria is responsible for calcium uptake. The calcium channels are used for cell signaling and triggering apoptosis. The calcium uniporter transports calcium across the inner mitochondrial membrane and is activated when calcium rises above a certain concentration. The amino acid transporters function in transporting neutral amino acids for neurotransmitter production in brain cells. Voltage-gated potassium channels are also uniporters found in neurons and are essential for action potentials. This channel is activated by a voltage gradient created by sodium-potassium pumps. When the membrane reaches a certain voltage, the channels open, which depolarizes the membrane, leading to an action potential being sent down the membrane. Glucose transporters are found in the plasma membrane and play a role in transporting glucose. They help to bring glucose from the blood or extracellular space into cells usually to be utilized for metabolic processes in generating energy. Uniporters are essential for certain physiological processes in cells, such as nutrient uptake, waste removal, and maintenance of ionic balance.
== Selected-reaction monitoring chromatogram (SRM, MRM) == The selected-reaction monitoring (SRM) experiment is very similar to the SIM experiment except that tandem mass spectrometry is used and a specific product ion of a specific parent ion is detected. The mass of the parent analyte is first selected while other ions are filtered away. The parent analyte ion is then fragmented in the gas phase and a specific fragment ion is monitored. This experiment has very high specificity because the SRM chromatogram represents only ions of a particular mass that fragment in a manner that produce a very specific product mass. This type of experiment can only be performed using tandem mass spectrometry. The technology progress in the MS/MS area lead to the development of MRM, Multiple Reaction Monitoring, which allows simultaneous detection of several coeluting analytes with different parent and/or product ions.
Biosynthesis of a particular hormone in a particular tissue. Storage and secretion of the hormone. Transport of the hormone to the target cell(s). Recognition of the hormone by an associated cell membrane or intracellular receptor protein. Relay and amplification of the received hormonal signal via a signal transduction process: This then leads to a cellular response. The reaction of the target cells may then be recognized by the original hormone-producing cells, leading to a downregulation in hormone production. This is an example of a homeostatic negative feedback loop. Breakdown of the hormone. Exocytosis and other methods of membrane transport are used to secrete hormones when the endocrine glands are signaled. The hierarchical model is an oversimplification of the hormonal signaling process. Cellular recipients of a particular hormonal signal may be one of several cell types that reside within a number of different tissues, as is the case for insulin, which triggers a diverse range of systemic physiological effects. Different tissue types may also respond differently to the same hormonal signal.
To enforce the amendment, Congress passed the National Prohibition Act, also known as the Volstead Act. The Prohibition Bureau Narcotics Division, which enforced the Harrison Act, was overseen by Levi G. Nutt, the 1st narcotics commissioner of the United States. By the 1930s, the policy was seen as a failure: production and consumption of alcohol persisted, organized crime flourished in the alcohol black market, and tax revenue, particularly needed after the start of the Great Depression in 1929, was lost. Prohibition was repealed by passage of the 21st Amendment in 1933, with President Franklin D. Roosevelt (1933–1945) asking Americans not to abuse "this return to personal freedom." In 1922, the Narcotic Drugs Import and Export Act broadened federal regulation of opiates and coca products by prohibiting import and export for non-medical use, and established the Federal Narcotics Control Board (FNCB) to administrate.
A 2023 meta-analysis including 13 cardiovascular outcome trials reported that SGLT2 inhibitors reduce the risk for three-point major adverse cardiovascular events, especially in subjects with an estimated glomerular filtration rate (eGFR) below 60 mL/min, whereas GLP-1 receptor agonists were more beneficial in people with higher eGFRs. Likewise, the relative risk reduction of SGLT-2 inhibitor treatment was larger in populations with a higher proportion of albuminuria, but this relationship was not observed for GLP-1 receptor agonists. This suggests differential use of the two substance classes in people with preserved and reduced renal function or with and without diabetic nephropathy, respectively. GLP-1 agonists and SGLT2 inhibitors work to reduce HbA1c by different mechanisms and can be combined for enhanced effects. They may provide additive cardioprotective effects. The US Food and Drug Administration has not approved GLP-1 agonists for type 1 diabetes, but they have been used off-label in addition to insulin.
Sources: en.wikipedia.org
== Chemistry == Buspirone was originally classified as an azaspirodecanedione, shortened to azapirone or azaspirone due to the fact that its chemical structure contained this moiety, and other drugs with similar structures were labeled as such as well. However, despite all being called azapirones, not all of them actually contain the azapirodecanedione component, and most in fact do not or contain a variation of it. Additionally, many azapirones are also pyrimidinylpiperazines, though again this does not apply to them all. Drugs classed as azapirones can be identified by their -spirone or -pirone suffix.
== Degradation == Prostacyclin, which has a half-life of 42 seconds, is broken down into 6-keto-PGF1, which is a much weaker vasodilator. A way to stabilize prostacyclin in its active form, especially during drug delivery, is to prepare prostacyclin in alkaline buffer. Even at physiological pH, prostacyclin can rapidly form the inactive hydration product 6-keto-prostaglandin F1α.
Bancroft, EA (October 2007). "Antimicrobial resistance: it's not just for hospitals". JAMA. 298 (15): 1803–1804. doi:10.1001/jama.298.15.1803. PMC 2536104. PMID 17940239. Larson, E (2007). "Community factors in the development of antibiotic resistance". Annual Review of Public Health. 28 (1): 435–447. doi:10.1146/annurev.publhealth.28.021406.144020. PMID 17094768.
Insight – emphasis is on gaining a greater understanding of the motivations underlying one's thoughts and feelings (e.g. psychodynamic therapy) Action – focus is on making changes in how one thinks and acts (e.g. solution focused therapy, cognitive behavioral therapy) In-session – interventions center on the here-and-now interaction between client and therapist (e.g. humanistic therapy, Gestalt therapy) Out-session – a large portion of therapeutic work is intended to happen outside of session (e.g. bibliotherapy, rational emotive behavior therapy) The methods used are also different in regards to the population being served as well as the context and nature of the problem. Therapy will look very different between, say, a traumatized child, a depressed but high-functioning adult, a group of people recovering from substance dependence, and a ward of the state suffering from terrifying delusions. Other elements that play a critical role in the process of psychotherapy include the environment, culture, age, cognitive functioning, motivation, and duration (i.e. brief or long-term therapy).
Sources: en.wikipedia.org
Yes, the terms are generally interchangeable. Lyophilization is more common in pharmaceutical and laboratory contexts, while freeze-drying appears widely in food science and general writing. Both describe removal of solvent by sublimation under vacuum after freezing.
Reduced pressure keeps the process below the triple point of water, so ice can sublimate directly to vapor. It also lowers the temperature needed for drying, which helps preserve heat-sensitive materials. Without vacuum, melting or boiling could occur instead of controlled sublimation.
The rate depends on heat transfer to the product and mass transfer of vapor through the dried layer. A cold condenser, adequate vacuum, and suitable shelf temperature all influence speed. Formulation properties such as solid content and collapse temperature also set practical limits.
Freezing only converts liquid to solid. Lyophilization adds vacuum and controlled warming so frozen solvent sublimes, leaving a dry porous solid. The two steps are related but not interchangeable.