This is a working overview of Collapse temperature, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-12-12. Anything still debated is marked as such rather than presented as settled.
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 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.
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.
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.
| 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. |
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.
Lyophilization removes water by freezing a material and then lowering pressure so ice changes directly to vapor. The process relies on sublimation, the phase transition from solid to gas without an intermediate liquid state. Because the material remains frozen during primary drying, the structure often stays porous. This porous matrix can rehydrate quickly when water is added back. The low pressure also allows vapor to leave the solid matrix without boiling.
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.
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.
==== Other actions ==== Phenylpiracetam binds to α4β2 nicotinic acetylcholine receptors in the mouse brain cortex with an IC50Tooltip half-maximal inhibitory concentration of 5.86 μM. Racetams generally, but including phenylpiracetam, have been described as AMPA receptor potentiators.
== Design nanoparticle self-assembly structure == Self-assembly of nanoparticles is driven by either maximization of packing density or minimization of the contact area between particles according to hard or soft nanoparticles. Examples of hard nanoparticles are: silica, fullerenes; soft nanoparticles are often organic nanoparticles, block copolymer micelles, DNA nanoparticles. The ordered self-assembly structure of nanoparticles is called superlattice.
A Daily Telegraph report alleging a conflict-of-interest involving First Minister of Scotland Humza Yousaf after the Scottish Government donated £250,000 to the UN agency UNRWA, which supports Palestinian refugees, is rejected by Yousaf as an "outrageous smear" and a "far right conspiracy". 10 March – BBC News reports that former prime minister Boris Johnson flew to Venezuela during February for an unofficial private meeting with President Nicolás Maduro. 11 March – Ashfield MP Lee Anderson defects from the Conservatives to Reform UK, becoming the party's first sitting Member of Parliament. Addressing the Institute for Government, former prime minister Sir John Major criticises his recent Conservative successors for the attitude towards the civil service, and describes the quick succession of prime ministers in recent years as "not conducive to good government". As the UK government prepares to redraw the definition of extremism, former Home Secretaries Priti Patel, Sajid Javid and Amber Rudd warn against attempting to politicise extremism at the next election. After the Welsh Government publishes plans to require parties in the Senedd to draw up lists of candidates composing of 50% of women, presiding officer Elin Jones says that the Senedd does not have the power to enforce gender quotas. Conservative Party donor Frank Hester apologises after The Guardian reported comments he is alleged to have made in 2019 about Labour MP Diane Abbott, when he is said to have suggested she made him "want to hate all black women" and that she "should be shot".
There has been recent speculation that the increase in such carbohydrates since sucrose (table sugar—half glucose and half fructose) became available in quantity after about 1700 with the discovery of a practical source (sugar cane), accounts for some of the diseases of civilization, including diabetes. Fructose had been quite rare in human diet until that time. Dietary fructose also characteristically causes alterations in blood lipid profiles, probably by changing liver operations. Cardiologist a physician with special training for treating heart and circulatory problems. Cardiovascular pertaining to the heart and vascular system (blood vessels). Carpal tunnel syndrome irritation and swelling of one or more of the nerves in the carpal tunnel in the wrist. Effects range from considerable pain to loss of strength or muscle control. The cause is thought to be mechanical, as in repetitive motion of the wrist joint as in typing while in inappropriate wrist positions. Cataract clouding of the transparent protein in the lens of the eye. A certain amount of this clouding occurs naturally during life. The elderly do not, therefore see quite the same way as they used to since there is a slight yellowish cast in the clouded lens. Diabetics have an increased risk for cataract since high levels of glucose cause reactions with assorted proteins, including those in the lens; many of the reaction products are not optically clear, nor pack in the same way, thus altering the shape of the lens.
Sources: en.wikipedia.org
Pioglitazone, sold under the brand name Actos among others, is an anti-diabetic medication used to treat type 2 diabetes. It may be used with metformin, a sulfonylurea, or insulin. Use is recommended together with exercise and diet. It is not recommended in type 1 diabetes. It is taken by mouth. Common side effects include headaches, muscle pains, inflammation of the throat, and swelling. Serious side effects may include bladder cancer, low blood sugar, heart failure, and osteoporosis. Use is not recommended in pregnancy or breastfeeding. It is in the thiazolidinedione (TZD) class and works by improving sensitivity of tissues to insulin. Pioglitazone was patented in 1985, and came into medical use in 1999. It is available as a generic medication. In 2023, it was the 133rd most commonly prescribed medication in the United States, with more than 4 million prescriptions. It was withdrawn in France and Germany in 2011.
== Clinical significance == Some can be useful in measuring rates of metabolic processes (for example, 3,4-dihydroxyphenylacetic acid or 3-aminoisobutyrate). Because they can represent unnatural points of entry into natural metabolic pathways, some (such as AICA ribonucleotide) are of interest to researchers in developing new therapies.
In August 1950, the Lao Prince Souphanouvong convened the first congress of the Pathet Lao, which was supported by Viet Minh and served as the vehicle for the communist challenge to French rule. On 13 August 1950, he was elected President of the Congress of the Pathet Lao, which met at the Việt Minh headquarters in Tuyen Quang, North Vietnam. In 1953, Pathet Lao fighters accompanied an invasion of Laos from Vietnam led by Viet Minh forces; they established a government at Viengxay in Houaphanh province, northeast Laos.
Vaccinations given to children, adolescents, or adults are generally safe. Adverse effects, if any, are generally mild. The rate of side effects depends on the vaccine in question. Some common side effects include fever, pain around the injection site, and muscle aches. Additionally, some individuals may be allergic to ingredients in the vaccine. The MMR vaccine is rarely associated with febrile seizures. Host-("vaccinee")-related determinants that render a person susceptible to infection, such as genetics, health status (underlying disease, nutrition, pregnancy, sensitivities or allergies), immune competence, age, and economic impact or cultural environment can be primary or secondary factors affecting the severity of infection and response to a vaccine. Elderly (above age 60), allergen-hypersensitive, and obese people have susceptibility to compromised immunogenicity, which prevents or inhibits vaccine effectiveness, possibly requiring separate vaccine technologies for these specific populations or repetitive booster vaccinations to limit virus transmission. Severe side effects are extremely rare. Varicella vaccine is rarely associated with complications in immunodeficient individuals, and rotavirus vaccines are moderately associated with intussusception. At least 19 countries have no-fault compensation programs to provide compensation for those with severe adverse effects of vaccination. The United States' program is known as the National Childhood Vaccine Injury Act, and the United Kingdom employs the Vaccine Damage Payment.
Pathology Messaging Implementation Project (PMIP) is the project that introduced universal delivery of electronic pathology results to GPs in Great Britain. The resulting standard was formalised in 2003 as ISB 1557. It uses UN-EDIFACT based messages. More than 20 years later it remains extensively used by the British National Health Service (NHS) to transmit pathology orders and pathology test results. PMIP began in the United Kingdom as the PMEP (Pathology Messaging Enabling Project) under the control of the NHS Information Authority and was supported by the Royal College of Pathologists (Dr Rick Jones), the Royal College of GPs (Dr Stephen Pill) and the British Medical Association. PMIP was designed for the transmission of structured pathology orders and their associated results between pathology and primary care systems. The message definition followed the work on standardisation led by Dr Jonathan Kay and Dr John McVittie and was implemented in UN-EDIFACT as required at the time by the Department of Health. Originally messages were to be encrypted end-to-end (organisation-to-organisation) using public key infrastructure (PKI). The NHS subsequently moved to an alternative strategy using Data Transfer Service (DTS). Messages are encrypted from the pathology laboratory to the DTS server, and again from the DTS server to the General Practitioner using the PMIP interim messaging cryptographic service. The DTS provides application-to-application messaging within the NHS as well as providing a replacement for the X.400 service.
Sources: en.wikipedia.org
On election night, incumbent prime minister Anutin Charnvirakul of the Bhumjaithai Party claimed victory on projections giving his party around 194 seats, while Natthaphong Ruengpanyawut conceded on projections of just over 116 seats for the opposition People's Party. The Pheu Thai Party, led by Yodchanan Wongsawat, was projected third on around 76 seats. The Election Commission certified 396 constituency seats on 25 February and three more on 4 March, along with all 100 party-list seats. Certification of Suphan Buri constituency 2 was withheld over suspected misconduct by polling officials and was issued on 8 April, bringing the House to its full membership of 500. The certified results gave Bhumjaithai 192 seats, the People's Party 120 and Pheu Thai 74.
Atoltivimab/maftivimab/odesivimab, sold under the brand name INMAZEB, is a fixed-dose combination of three monoclonal antibodies for the treatment of ebola caused by Zaire ebolavirus. It was developed by Regeneron Pharmaceuticals and contains three human monoclonal antibodies, atoltivimab, maftivimab, and odesivimab-ebgn. The most common side effects include fever, chills, tachycardia (fast heart rate), tachypnea (fast breathing), and vomiting; however, these are also common symptoms of Ebola virus infection. Atoltivimab/maftivimab/odesivimab is the first FDA-approved treatment for Zaire ebolavirus. Atoltivimab/maftivimab/odesivimab was approved for medical use in the United States in October 2020. The U.S. Food and Drug Administration (FDA) considers it to be a first-in-class medication. It is on the World Health Organization's List of Essential Medicines. Atoltivimab/maftivimab/odesivimab is indicated for the treatment of infection caused by Zaire ebolavirus.
3D cell-culture models exceed 2D culture systems by promoting higher levels of cell differentiation and tissue organization. 3D culture systems are more successful because the flexibility of the ECM gels accommodates shape changes and cell-cell connections – formerly prohibited by rigid 2D culture substrates. The most widely used 3D cell culture models include spheroids and organoids. Nevertheless, even the best 3D culture models fail to mimic an organ's cellular properties in many aspects, including tissue-to-tissue interfaces (e.g., epithelium and vascular endothelium), spatiotemporal gradients of chemicals, and the mechanically active microenvironments (e.g. arteries' vasoconstriction and vasodilator responses to temperature differentials). The application of microfluidics in organs-on-chips enables the efficient transport and distribution of nutrients and other soluble cues throughout the viable 3D tissue constructs. Organs-on-chips are referred to as the next wave of 3D cell-culture models that mimic whole living organs' biological activities, dynamic mechanical properties and biochemical functionalities.
A blood glucose meter is an electronic device for measuring the blood glucose level. A relatively small drop of blood is placed on a disposable test strip which interfaces with a digital meter. Within several seconds, the level of blood glucose will be shown on the digital display. Needing only a small drop of blood for the meter means that the time and effort required for testing are reduced and the compliance of diabetic people to their testing regimens is improved significantly. Blood glucose meters provide results in various units such as eAG (mg/dL) and eAG (mmol/L), and may also estimate A1C levels. These measurements can aid in classifying blood glucose levels as normal, prediabetic, or diabetic, facilitating effective diabetes management for users. While some models offer interpretative features that indicate the health status based on these results, not all meters provide this functionality, focusing instead on providing raw glucose measurements. Users of blood glucose meters without interpretative features can utilize online calculators to determine their blood glucose status based on measured values. The cost of using blood glucose meters is believed to be a cost-benefit relative to the avoided medical costs of the complications of diabetes. Recent advances include:
80. Coll Antropol. 2005 Jun;29(1):321-5. Gastric pentadecapeptide BPC 157 promotes corneal epithelial defects healing in rats. Lazić R(1), Gabrić N, Dekaris I, Bosnar D, Boban-Blagaić A, Sikirić P. Author information: (1)Eye Clinic, Svjetlost, Zagreb, Croatia. ratimir.lazic@zg.htnet.hr We evaluated the role of human gastric pentadecapeptide BPC 157 in corneal epithelial defects healing in rats. 48 rats, in 4 groups (N=12). Total debridement of corneal epithelium preformed unilaterally and lesions stained and photographed. Animals medicated as follows: distilled water (control group) or BPC 157 2 pg/ml, 2 ng/ml, 2 microg/ml, 2 drops/rat eye started immediately after injury induction, every 8 hours up to 40 hours (i.e., at 0, 8, 16, 24, 32, 40 h). Lesions were photographed before application or sacrifice (at 48 h). Defect area was analyzed using a special program. Through 48 hour period a steady recovery is noted in controls. Recovery was markedly accelerated in eyes on microg- or ng-topical regimen of BPC 157 (p < 0.05). Of note, unlike control lesion present also after 48 h, these lesions disappeared already following 40 h (microg) or 48 h (ng) post-injury. BPC 157 was shown to be effective in promoting corneal defects healing in rats. Results were dose dependent.
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.
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.